baha'a.doc j bagh college dentistry vol. 28(1), march 2016 the fluoride pedodontics, orthodontics and preventive dentistry 143 the fluoride concentration of bottled drinking water in al-basra city, iraq baha'a a. jeri, b.d.s., m.sc. (1) abstract background: this study aimed to determine the amount of fluoride in commercially available bottled drinking water in al-basra city, iraq materials and methods: eleven brands of bottled drinking water were obtained from supermarkets in al-basra city, iraq. five samples of 10 ml. were taking from each one of brands and the fluoride was determined by using fluoride ion selective electrode. results: the highest fluoride concentration was present in badiot brand (1.174 mg/l) while the lowest was in barakat brand (0.038 mg/l). one way anova test showed a highley significant difference among different commercially branded types. coclusions: bottled water available in al-basra city contains less concentration of fluoride ion than normal values because there is no adding of fluoride to the water. key words: bottled water, fluoride, al-basra, iraq. (j bagh coll dentistry 2016; 28(1):143-146). introduction in recent year, most iraqies drink bottled water which replace tap water. sales of bottled water have increased and different types and brands of bottled water are available in al-basra city supermarkets. water fluoridation is considered as one of the most efficient methods in reduction of dental caries on public health level and its greatest influence on socially care of children with higher prevalence of tooth decay (1). dental caries is a multifactorial disease depending on presence of bacteria (mostly streptococcus mutans), diet (mostly sugar) and host which mean tooth. inorganic ion in tooth composition are calcium, phosphate and fluoride form chemical formula (hydroxyapetite crystal)(2). fluoride exerts its anticaries effect by two different mechanism; first the presence of fluoride ion enhances the precipitation of fluoroapetite into tooth structure, this insoluble precipitate replace the soluble salts containing manganese and carbonate that were lost because of bacteriamediated demineralization. this exchange process results in the enamel become more acid resistant which secreted from bacteria. the second mechanism; fluoride has antimicrobial activity. low concentration of fluoride ion inhibits the enzymatic production of glucosyl transferase which promotes glucose to form extracellular polysaccharide and increases bacteria adhesion (2) so when fluoride is available during cycles of tooth demineralization, it plays a major role in reduction caries activity (3). (1)assistant instructor. college of dentistry, university of albasra. the availability of fluoride to reduce caries risk is thought to be primarily achieved by water fluoridated community, fluoride ions also intake from other source like diet, tooth pastes, mouth rinse, professional topical fluoridation application(4). fluoride supplements should be considered for all children who drink water with fluoride at least 0.6 ppm (5). epa recommended maximum amount of fluoride allowed in drinking water about 4.0 mg/l more than that lead to risk of crippling skeletal fluorosis (6). while hhs gives optimal who determined the majority of bottled water fluoridation to be 1.5 mg/l (8). fda set limits for fluoride in bottled water based on several factors, including the source of water, it gave range from 0.8-2.4 mg/l (16). the laboratory finding of fluoride concentration ranged between 0.32 1.1 ppm (17). materials and methods eleven brands of bottled drinking water were obtained from supermarkets in al-basra city with different patch numbers and expire dates of bottling water . seven types from the samples made in factories inside the city while four types from other countries. only three samples mentioned the fluoride concentration on the label while other products have not that. all bottles were stored in dark place and in their original closed plastic containers at room temperature until fluoride concentration tested and ph of water tested also. after shaking the bottle of water, five samples were taking from each one of brands about 10 ml. samples were kept in container then coded so the type and brands were unknown by the technician labraratory test . samples were diluted with equal quantities of tisab (total ionic strength adjustment buffer, j bagh college dentistry vol. 28(1), march 2016 the fluoride pedodontics, orthodontics and preventive dentistry 144 usa). fluoride was determined by using fluoride ion selective electrode (model 96-09 ati orion) in conjunction with ise meter (model 720 a, ati orion) (9). ph of water sample was also measured using a ph meter (model 240, corning). statistical analyses all measurements were analyzed by using spss version 19. one-way anova test was used for comparison of fluoride contents among different brands of bottled water. one sample ttest was used to compare the label and laboratory values of bottled water. results the discriptive analyses of different brand types are show in table 1. the highest fluoride concentration was present in badiot brand (1.174 mg/l) while the lowest was in barakat brand (0.038 mg/l). one-way anova test showed statsitically highley significant difference among groups. table 2 represented the difference between each two brands using lsd test. generally, the difference was variables between the groups. three brands only mentioned the fluoride concentration on the lable. one sample t-test was used to compare the measured concentration with the labeled one and the results indicated a nonsignificant difference for evian and badiot brands and significant difference for oxab brand. discussion the detection of fluoride content in this area of iraq is so recommended because there is no previous research in this field so that no any comparison with other researches. generally, the concentration of fluoride in these branded types of bottled water is less than normal values (7,8,16), because there is no adding of any artificial fluoride ions and the source depends on natural finding in the river (shat-al-arab) drinking water inspectorate (dwi) of ministry of health in al-basra city did not supervised these factories and inform them the important of adding fluoride like other minerals in the drinking water which is essential to all health care professionally especially dentists. effective and safe preventive fluoride programs require an awareness of the exact concentration of drinking water either public or bottled. when prescribing fluoride supplement, dentists should be know the content of fluoride in bottled drinking water used by children which not increase higher than 0.5 ppm (10). the present study reported a narrow range in the fluoride concentration for the same patches and different branded product of the same local area, this disagrees with other studies (11,12) which showed significant difference between the batches of water products because the weather changes including heavy rains while in our region one sources of water from shatal-arab river. american dental association reported that safe concentration of fluoride is 0.7 -1.2 ppm (13) which is enough for protecting against tooth decay while in this research recommended concentration of fluoride with low level 0.07 ppm. but with warm city when people drink larger amount of water consumption due to hot temperature (14). only three samples has labeling information of fluoride concentration which are commercial in other countries. this is not agree with other researches that tested different types of bottled water with labeling reported information about fluoride concentration (10,15). table 1: comparison the fluoride concentration (mg/l) among bottled water bottled water source labeled content descriptive statsitics group's difference mean s.d. f-test p-value al-waha iraq not mentioned 0.079 0.008 535.245 0.000 (hs) evian france 0.6 0.653 0.042 al-khalij iraq not mentioned 0.043 0.013 al-janaa´en iraq not mentioned 0.075 0.017 aquafina kuwait not mentioned 0.333 0.050 salsal iraq not mentioned 0.058 0.001 badiot france 1.2 1.174 0.013 barakat iraq not mentioned 0.044 0.008 oxab iran 0.1 0.124 0.001 pure healthy water iraq not mentioned 0.126 0.013 aquazalzal iraq not mentioned 0.061 0.006 j bagh college dentistry vol. 28(1), march 2016 the fluoride pedodontics, orthodontics and preventive dentistry 145 table 2: lsd test after anova test bottled water mean difference p-value al-waha evian -0.574 0.000 (hs) al-khalij 0.036 0.132 (ns) al-janaa´en 0.004 0.875 (ns) aquafina -0.254 0.000 (hs) salsal 0.021 0.356 (ns) badiot -1.095 0.000 (hs) barakat 0.035 0.137 (ns) oxab -0.045 0.063 (ns) pure healthy water -0.047 0.054 (ns) aquazalzal 0.018 0.439 (ns) evian al-khalij 0.610 0.000 (hs) al-janaa´en 0.578 0.000 (hs) aquafina 0.320 0.000 (hs) salsal 0.595 0.000 (hs) badiot -0.521 0.000 (hs) barakat 0.609 0.000 (hs) oxab 0.529 0.000 (hs) pure healthy water 0.527 0.000 (hs) aquazalzal 0.592 0.000 (hs) al-khalij al-janaa´en -0.032 0.170 (ns) aquafina -0.290 0.000 (hs) salsal -0.015 0.520 (ns) badiot -1.131 0.000 (hs) barakat -0.001 0.982 (ns) oxab -0.081 0.004 (hs) pure healthy water -0.083 0.003 (hs) aquazalzal -0.018 0.426 (ns) al-janaa´en aquafina -0.258 0.000 (hs) salsal 0.018 0.439 (ns) badiot -1.099 0.000 (hs) barakat 0.032 0.176 (ns) oxab -0.049 0.048 (s) pure healthy water -0.051 0.041 (s) aquazalzal 0.014 0.534 (ns) aquafina salsal 0.275 0.000 (hs) badiot -0.841 0.000 (hs) barakat 0.289 0.000 (hs) oxab 0.209 0.000 (hs) pure healthy water 0.207 0.000 (hs) aquazalzal 0.272 0.000 (hs) salsal badiot -1.116 0.000 (hs) barakat 0.014 0.534 (ns) oxab -0.066 0.011 (s) pure healthy water -0.068 0.010 (hs) aquazalzal -0.004 0.875 (ns) badiot barakat 1.130 0.000 (hs) oxab 1.050 0.000 (hs) pure healthy water 1.048 0.000 (hs) aquazalzal 1.113 0.000 (hs) barakat oxab -0.080 0.004 (hs) pure healthy water -0.082 0.003 (hs) aquazalzal -0.018 0.439 (ns) oxab pure healthy water -0.002 0.929 (ns) aquazalzal 0.063 0.015 (s) pure healthy water aquazalzal 0.065 0.013 (s) table 3:comparing the labeled fluoride content with the measured one using one-sample t-test bottled water t-test d.f. p-value evian 1.780 1 0.326 (ns) badiot -2.789 1 0.219 (ns) oxab 47 1 0.014 (s) j bagh college dentistry vol. 28(1), march 2016 the fluoride pedodontics, orthodontics and preventive dentistry 146 dentists should have information about water fluoridation reliable values which effect on decision for giving fluoride supplement from other sources like topical fluoridation in case of high caries activity specially when dealing with children. in addition, drinking water inspectorate need more closed supervision on factories that monitor fluoride and other ions minerals in drinking water with accurately reported labeling information. as conclusions; bottled water available in albasra contains less concentration of fluoride ion because there is no adding of fluoride to the water. it is not so effective as a preventive dental caries program. all types of products prepared in factories of our city not mention fluoride concentration in the label display. references 1harrison ptc. flouride in water; uk perspective. j flour chem 2005;126:1448-56 2heymann ho, swift e jr., ritter av. sturdevant’s art and science of operative dentistry. 6th ed. st. louis, elseiver mosby; 2013. 3broun lj, lazar v. the economic state of dentistry . demand-side trends. j am dent assoc 1998;129(12): 1685-91. 4roberson t, heymann h, swift ed. sturdevant’s art and science of operative dentistry. 5th ed. st. louis, elseiver mosby; 2006. 5adair sm. evidence-based used of fluoride in contemporary pediatric dental practice. pediatr dent 2006; 28(2):133-42. 6united states environmental protection agency (epa) hhs : human health service 2011. 7world health organization: average fluoride concentration: who 2004 8christian gd. analytic chemistry. hoboken: john wily and sons inc.; 2004. 9ahiropoulos v. fluoride content of bottled water available in northern greece. int j pediatric dent 2006; 16(2):111-6 10quok rl, chan jt. fluoride contents of bottled water and its implication for the general dentis. gen dent 2009; 57(1): 29:33 11bartels d, haney k, khajotia ss. fluoride concentration in bottled water. j okla dent assoc 2000; 91(1): 18-22. 12american dental association (updated on june 5. 2002), american dental statement on water fluoridation efficacy and safety 13al-dosari am, akpata es, khan n, wyne ah, al meheithif a. fluoride level in drinking water in the central province of saudi arabia. ann saudi med 2003; 23(12): 20-3 14tomba kj, levy s, curzon me. the fluoride content of bottled water drinking water. br dent j 1994; 176(7): 266-8 15khan nb, chohan an. accuracy of bottled drinking water label content. environ monit assess 2010; 166(14): 169-76. fadia.docx j bagh college dentistry vol. 28(1), march 2016 the prevalence basic sciences 179 the prevalence of oral protozoa trichomonas tenax in some patients with gingivitis fadia abd al-muhsin al-khayat, ph.d. (1) abstract background: as a relationship between gingivitis disease and the presence of the oral protozoa trichomonas tenax has been represented by considerable differences among various study population. the purpose of present study is determining the prevalence of t.tenax in patients with gingivitis and healthy subjects. subjects, materials and methods: the presence of the parasite has been diagnosed with 58 patients with gingivitis and 58 healthy persons during the period of the study(april and may 2015) by taken two swabs for each one, microscopic examination was done using saline wet mount method and stained method. age, sex and brushing teeth habit were in a count. statistical analysis was done by spss program. results: gingivitis disease was observed in 58patients among the total 163 examined subjects (35.58%)with a highly significant differences p<0.01 recorded between males and females(40.22%,30.26% respectively).the prevalence of t. tenax in gingivitis patients was higher than healthy(56.89%,6.89%)respectively. according to gender and age the highly prevalence rate was demonstrated in males (62.85%) and in the age category 51-60 years old (92.8%). data analysis showed that a highly significant differences p<0.01was demonstrated in the prevalence rate between brushing teeth users 29.1% and non-brushing teeth users 11.9%. conclusion: the study confirmed the existence of a relationship between parasite infection and gingivitis disease where the higher prevalence of t. tenax was found in gingivitis patients compared with healthy controls. people should receive dental care to gain high hygiene oral cavity and have low infection to t. tenax. keyword: gingivitis, protozoa, trichomonas tenax. (j bagh coll dentistry 2016; 28(1):179-182). introduction one of the trichomonadidae family membersis the protozoa parasite trichomonas tenax which commonly found in oral cavity of humans and frequently associated with necrotizing ulcerative gingivitis in patients with bad oral hygiene(1). t. tenax infection typically produce oral tissue damages and bronchopulmonarytrichomoniasis disease may be caused when the parasite enters the respiratory tract by aspiration (2). the main source of infection occurs by direct and /or indirect mouth to mouth contact, the trophozoite (the only stage in its life cycle) transmit through contaminated eating utensils (cups, dishes), saliva droplet spray, and kissing(3). association between this parasite of public health importance and oral diseases is not well ascertained. so the present study was designed to determine the prevalence of t. tenax inpatients suffering from gingivitis, age, gender, and brushing habit were in a count. subject, materials and methods for two months (april and may 2015) a total of 163 patients of both sex and different ages (87 male,76 female) who attended teaching hospital of dentistry college-clinics of periodonticsbaghdad university were examined by periodon (1)lecturer, department of basic sciences, college of dentistry, university of baghdad. tistto detect oral diseases including gingivitis, the diagnosis depend on clinical feature including color, size, shape, consistency, texture, bleeding and painful gingiva. case history was observed including general health, smoking, brushing teeth and antibiotic consumption. fifty eight from the total number which recorded as a healthy gingiva persons were chosen as control group, while the remaining 47 patients were diagnosed with other oral cavity diseases. direct examination by light microscopic is the simplest method for parasitic detection, saline wet mount method was used as the collection of samples was done by a sterile swab(for conformation two swabs were taken from each patient)pass over and around the gingival crevices, the swab was dipped in sterile tube containing normal saline, after that the swab rolled on the clean glass slide and examined under 10x and 40x lens (4), the t. tenax trophozoite was identified by its circular movement, oval to pear shaped, measuring about 5 14 μm long and observation of five flagella (4 extend anteriorly and one extends posteriorly). to confirm the identification, all samples were stained with methylene blue stain for 5min. and wash the slide by distilled water (5). statistical analysis was done by spss .v.16, the inertial statistic use chi-square-test with-pvalue if p<0.05 significant, p>0.05 non significant, p<0.01 high significant. j bagh college dentistry vol. 28(1), march 2016 the prevalence basic sciences 180 results in table 1, fifty eight patients were recorded as positive for gingivitis from the total examined number 163 including 35/87 male and 23/76 female. the overall oral gingivitis rate was 35.58%, statistic results revealed that highly significant differences (p<0.01) were observed between male and female 40.22%,30.26% respectively. in table 2, highly significant differences (p<0.01) were demonstrated in the presence of t. tenax which detected in 33/58 gingivitis patients (56.89%) in compare with only 4/58 of the healthy patients (6.89%) table 1: gingivitis rate among 163 patients infection % no. positive no. examined sex 40.22 35 87 male 30.26 23 76 female 35.58 58 163 total *chi-square=53.395, p<0.01 high significant table 2: detection of t. tenax in gingivitis and healthy patients groups no. examined no. positive percentage% gingivitis patients 58 33 56.89 healthy patients 58 4 6.89 total 116 37 31.89 *chi-square=27.356, p<0.01 high significant as shown in table 3, the prevalence of t. tenax was higher in males than females, detection was observed in 22/35 males (62.85%), on the other hand from 23 females only 11 were recorded positive (47.82%).the total number of positive diagnosis for t. tenax was 33 with a prevalence rate 56.89% also a highly significant differences (p<0.01) was observed. table 3: prevalence of t. tenax in gingivitis patients according to gender sex no. examined no. positive for t.tenax prevalence rate % male 35 22 62.85 female 23 11 47.82 total 58 33 56.89 *chi-square=28.653, p<0.01 high significant the total number of infections for t. tenax was 33 (56.89%), distributed between the 22 number of infected males (37.9%) and 11number of infected females (18.9%).it included the age categories from 20 t0 60 years old, the higher infection rate was recorded in the age group 5160(92.8%) while the lower one was in 20-30 age group(16.66%). statistically, there was no significant differences among numbers examined while significant differences (p<0.05) was observed among positive number(table 4). table 4: prevalence of t.tenax in gingivitis patients according to age age year no. examined t m f no. positive m f t infection rate % m f t 20-30 12 9 4 2 0 2 16.66 0 16.66 31-40 15 11 6 6 2 8 40 13.33 40 41-50 17 8 6 8 4 12 47 23.52 70.5 51-60 14 7 7 6 5 11 42.85 35.71 92.8 total 58 35 23 22 11 33 37.9 18.9 56.89 *chi-square=2.667, p=0.102 p>0.05 non significant of no. examined *chi-square=3.270, p=0.043 p<0.05 significant of no. positive according to brushing teeth habit, the prevalence of t. tenax as higher in non-brush tooth users 29.1% as a total of 79 patients were examined and 23 were positive, in compare with a total of 84 brush-tooth users examined in which t. tenax was recorded in 10 patients with prevalence rat 11.9%.thirty three is the positive number from the total 163 with a total prevalence rate 20.24 which means highly significant differences between the two categories. j bagh college dentistry vol. 28(1), march 2016 the prevalence basic sciences 181 table 5: t. tenax prevalence according to brushing teeth habit no. examined no. positive prevalence % non-brush tooth users 79 23 29.1 brush tooth users 84 10 11.9 total 163 33 20.24 *chi-square=28.435, p<0.01 high significant discussion the inflammation of the gum tissue (gingivitis) is in response to bacterial biofilms (plaque), the main clinical features for diagnosis include the color (bright red), size and shape (swollen), consistency (soft), texture (loss of stippling), bleeding and painful gingiva with bad breath (6). current results showed that the prevalence of gingivitis was 35.58%. in a study done by khansa (7), the results revealed that the prevalence of gingivitis recorded 76%. also sarah (8) found that the prevalence was 69%. the differences between results among studies may depend on some factors that play a role in the prevalence such as poor oral hygiene, education and social level and different diagnostic criteria (9). most gingival patients were males 35/87(40.22%), while females recorded 23/76(30.26%) this may be attributed to smoking habit, this finding can be explained as smoking affects the prevalence, severity of disease by increasing the levels of calculus and plaque, affected the immune response and decreasing gingival circulation (10) an agreement with our results reported by sabrina (11) and villa (12). oral protozoa t. tenax showed higher prevalence (56.89%) in patients of this study than other published reports (13,14). worldwide, the prevalence ranges from 4.0 to 53% (15).the rezone for this higher prevalence might be related to different diagnosis methods and periods of study .in brazil a study documented the prevalence of t. tenax was 23.53% (16). also ahmed (17) examined 33 gingivitis case and recorded the prevalence rate 14.2%.another study showed that from 30 gingivitis case, t. tenax was observed in saliva samples 46.6% while in dental plaque samples 30%(18). in this study, out of 58 healthy patients , observation of t. tenax was in 4 (6.89%). usually, healthy oral cavity did not provide favorable anaerobic conditions for the growth and survival of the parasite (19).a relationship has been demonstrated between the occurrence of t.tenax and gingivitis disease (15). according to gender, data revealed that 33 of 58(56.89%) patients with gingivitis showed the presence of t. tenax. males recorded higher prevalence than females (62.85%, 47.82% respectively)which indicated the similarity with other studies, this could be due to physiological and immunological condition. in america, a study on american population showed males were affected more as compared to females significantly higher (p<0.001) than the females (20). another study was found that the prevalence of t. tenax was 53% in males and in females was (47%) (8). according to age, the higher prevalence of t. tenax was detected in age group51-60 years old (92.8%)where persons of this group might have less careful about oral hygienic behaviors such as smoking, un-brushing teeth also immunologic level might play a role. similar finding was observed and explained that there is a direct correlation between age and oral protozoan (13,2123). according to the effect of brushing teeth on the prevalence of t. tenax, data showed that higher prevalence recorded in non-brushing teeth persons 29.1% while 11.9 was the rate of infection in brushing teeth persons, these results improved oral hygiene might be effective in elimination the infection. these results were compatible with other researches (24). references 1. gharavi mj. the text book of clinical protozoalogy 3rd ed. eimoorzadehpubl; 2004. 30869. 2. chinche l, donati s, corno g, benoit s and granier i, chouraki m. trichomonas tenax in pulmonary and pleural diseases. presse med 2005; 34: 1371-72. 3. brooks gf, carroll kc, butel js, morse sa. jawetz, melnick and adelberg’s medical microbiology. 24th ed. the mcgrw hill companies: 2007: 661-2. 4. navazesh m. methods for collecting saliva. ann n y acad sci 1993; 694: 72-7. 5. bafghi af, aflatoonian a, barzegarb, ghafourzadeh m, nabipour s. frequency distribution of trichomoniasis in pregnant women referred to health centers of ardakan, meibod and yazd, iran. jundishapur j microbiol 2009; 2(4): 132-9. 6. pihlstrom bl, michalowicz bs, johnson nw. periodontal diseases. lancet 2005; 366(9499): 180920. 7. khansa ta, zafer m f, yousef sk.prevalence and risk indicators of gingivitis and periodontitis in a multi-centre study in north jordan: a cross sectional study.bmc oral health 2012; 12:1 8. sarah a, nomaan n, abida m, ulfat b. prevalence of gingivitis in patients visiting islamic international j bagh college dentistry vol. 28(1), march 2016 the prevalence basic sciences 182 dental hospital. ann pak inst med sci 2012; 8(2): 150-2. 9. baelumv, fejerskov o, karring t. oral hygiene, gingivitis and periodontal breakdown in adult tanzanians. j periodontal res 1968; 21:221-32. 10. linden gj, mullally bh. cigarette smoking and periodontal destruction in young adults. journal of periodontol 1994; 65: 718-23. 11. sabrina cg, flávia bp, rui vo, cristiano sr, adriana cm. the effect of smoking on gingival crevicular fluid volume during the treatment of gingivitis. acta odontol latinoam 2009; 22(3): 201-6 12. villa cc, matorelli af. smoking influences on the thickness of marginal epithelium. pesqui odontol bras 2003; 17: 41-5. 13. vrablic j, tomova s, cattar g, randova l, suttova s. morphology and diagnosis of entamoebagingivalisand trichomonastenaxand their occurrence in children and adolescents. bratisl leklisty 1991; 92(5): 241-6. 14. sarowska j, wojnicz d, kaczkowskih,jankowski s. the occurrence of entamoebagingivalis and trichomonas tenax in patients with periodontal disease. adv clin exp med 2004; 13(2): 291-7. 15. athari a, soghandi l, haghighi a, kazemi b. prevalence of oral trichomoniasis` in patients with periodontitis and gingivitis using pcr and direct smear. iranian j publ health 2007; 36(3): 33-7. 16. ricardo lc, cláudia mm, wagnoas,juliana lr, flávia as. rgo rev gaúchaodontol., porto alegre 2011; 59(1):35-40. 17. ahmed kah, mahdi yk, youniss ak. prevalence of oral protozoa in periodontitis and gingivitis patients whose attended to clinics periodontics, dentistry college\ babylon university. j kufa university for biol 2011; 3(1):1-7. 18. sumaiah i, rasha a. evaluation of entamoebagingivalis and trichomonas tenaxin patients with periodontitis and gingivitis and its correlation with some risk factors. j bagh college dentistry 2012; 24(3):158-162. 19. abramova ei ,voskresenskaya ga. role played by oral trichomonas in the pathogenesis of periodontal disease. stomatol (mosk) 1980; 59: 28-30. 20. li y, lee s, hujoel p, su m, zhang w, kim j, zhang yp, devizio w. prevalence and severity of gingivitis in american adults. am j dent 2010; 23(1): 9-13. 21. van winkellhoff aj, bosch-tihofcj, winkel eg. correlation identification of oral protozoa dentes 2001; 73(6):13-29. 22. nagwa mes, eman mhm. detection of trichomonas tenax in patients with periodontitis using microscopy and culture compared to pcr. egypt j m sci 2008; 29 (1-2): 537-550 23. jawad sq. frequency of entamoebagingivalis and trichomonas tenax among patients with dental prosthesis-fixed or removable. j of college of basic education 2011; 68:97-100. 24. saadia sh, sanaa hm, mohammad ak. relationship between the dental health and prevalence's trichomonas tenax and entamoebagingivalis among patients attending dental clinics in kirkuk. j babylon university/pure and applied sciences 2012; 20(5): 1441-7. alia f.doc j bagh college dentistry vol. 25(4), december 2013 cephalometric analysis oral diagnosis 39 cephalometric analysis of craniofacial deformity of βthalassemic major by using computed tomography alia t. thajeel, b.d.s. (1) jamal ali al-taei, b.d.s., m.sc. (2) abstract background: thalassemia is a hereditary anemia resulting from defects in hemoglobin production. βthalassemia caused by decrease in the production of βglobin chains affect multiple organs and is associated with cranio-orofacial deformity which include prominent cheek bones and protrusive premaxilla with depression of the nasal bridge often referred to as “rodent or chip-munk face” with small mandible and cl.ii skeletal relationship. this study aimed to investigate cephalometric craniofacial parameters (skeletal) of βthalassemic major patients by using computed tomography and to compare findings with a group of healthy patients in the same age group. subject, materials and method: the study included (40) patients with βthalassemic major (20 female and 20 male) with age 8-15years compared with (40) healthy controls (20 female and 20 male) with the same age, who admitted to spiral computed tomography scan unit in x-ray institute in al-karkh general hospital to have computed tomography scan for the brain, paranasal and for orthodontic purpose from october 2011 to june 2012. cephalometric analysis of the selected four skeletal linear measurements and four skeletal angular measurements, by using direct analysis with software programs in a computer which is part of the computed tomography machine. results: there was no statistically significant difference between thalassemic males and females in all selected skeletal linear and angular measurements, thalassemic patients have a highly significant large anb angle and cl ii skeletal relationship, significant larger gonial angle, mandibular base length (me-go) is significantly shorter, retrognathic mandible (snb) is significantly decreased, highly significant shorter in total anterior facial height (n-me) and total posterior facial height (s-go), and also the ramus height is highly significant decreased. conclusion: in thalassemic patients, the skeletal morphology is recognizable and mandible is retrognathism and they have skeletal cl. ii pattern and computed tomography is useful tool for assessment of the cranio facial measurement. key words: thalassemia, computed tomography, skeletal, cephalometrics. (j bagh coll dentistry 2013; 25(4):39-43). introduction thalassemia is blood dyscrasia characterized by a peculiar alteration in skull and long bone structures, which produce a “rodent facial appearance”.(1)it is considered as heterogeneous inherited disorders that arise from mutation in the globin genes that reduce or totally abolish synthesis of one or more of the globin chains of hemoglobin(2) and produces a wide variety of signs and symptoms and complications in those who inherit this disease.(3)the modern concept of thalassemia is based upon studies carried out by many scientists; they classify it clinically into major, minor and intermedia depending on the presence or severity of the symptoms.(4)while the genetic classification is based on the globin chain involved into α and β-thalassemia.(5)the thalassemic patients characterized by having a prominent frontal bossing and bulging of the forehead and prominent frontal and parietal bones.(6) in the skull of older child; radiographically shows reformation of outer table in the frontal bone and resolving process in the parietal bone. thalassemic patient have high malar eminence and high bulging cheek bones, which give rodent features and the prominent malar eminence produ (1) master student, department of oral diagnosis, college of dentistry, baghdad university. (2) assistant professor, department of oral diagnosis, college of dentistry, baghdad university. cing obvious malocclusion in these patients.(6) bi-maxillary expansion is one of the classical clinical changes and the progressive maxillary enlargement, maxillary dysplasia, sever protrusion of the middle third of the face and maxillary tuberosity become widened; all these changes producing the typical facial appearance with sever degree of malocclusion.(7) many authors (8) found posterior rotation of the mandible and he found posterior (clock wise) mandibular rotation in the thalassemic children, the mandible have thin cortex and trabecular appear coarse in pattern with enlarged marrow space which is depressed as "chicken–wire".(9) dentition shows protrusion, flaring and spacing maxillary anterior teeth, open bite and other type of malocclusion (9, 10) as in figure (1). figure 1. photographic picture shows the facial appearance and malocclusion in beta thalassemic patient j bagh college dentistry vol. 25(4), december 2013 cephalometric analysis oral diagnosis 40 subjects, materials and methods a prospective study consists of (80) patients ranged from (8-15) years, divided into two groups, thalassemic patients and health group, each group composed of (40) subjects (20 males & 20 females) who admitted to spiral computed tomography scan unit in x-ray institute at alkarkh general hospital in baghdad to have computed tomographic scan for the brain, paranasal and for different orthodontic purposes (both for thalassemic patients and control groups) from october 2011 to june 2012. patient selected with no history of orthodontic treatment and maxillofacial surgery and facial trauma, no facial asymmetry and class-i molar relationship. the control group has the same criteria but in addition to: healthy and had no disease of genetic origin, no gross skeletal defects,(11) bilateral cl. i molar relationship based on angle classification normal over get and over bite(2mm), very mild spacing (accepted) or crowding (0-1) mm.(12) the examination was performed on multi– slice spiral tomography scanner (the philips brilliance ct-64 thickness of slice 0.5m). method cephalometric analysis: 1-3d measurements were measured by distance and angular tools of commercial software. each anatomic measurement was identified as a 3d point with the software. the software enables simultaneously recognizing the same spatial point in sagittal, coronal and axial planes, which are represented in three separate windows. a fourth window allows the recognition of the anatomic point on a volume rendered (vr) window, which is a 3d image of the skull (in sagittal view).(13) cephalometric points or anatomic landmarks were identified on its position by using definition of each point or landmark and draw line and angle between them (as in figure 2), using a sagittal view of the volume rendered window and measure the linear and angular measurements on the software of the ct scan. figure 2. volume rendered (vr) window with the linear and angular measurements on the software of the ct scan. cephalometric planes: mandibular plane (go. me), anterior facial height (n,me), posterior facial height (s.go), ramus height (ar-go). angular measurements: ar. go. me (cephalometric gonial angle), sna (skeletal), snb angle (skeletal), anb angle (skeletal). results • case (thalassemia) control difference in mean of skeletal linear measurements: the mean linear distance (go-me) was significantly lower in thalassemic patients (67.6±7.7) mm compared to control (75.3±7.7) mm. the mean linear distance (ar-go) was significantly lower in thalassemia patient (41.6±3.3) mm compared to control (44.9±3.3) mm. the mean linear distance (s-go) was significantly lower in thalassemic patient (69.1±6.3)mm compared to control (75.4±6.3)mm, and the mean linear distance (n-me)was significantly decreased in thalassemic patient (116.5±6.7)mm compared to control (123.2±6.7)mm. table (1)& figure(3). • case (thalassemia)control difference in mean of skeletal angular measurements: the mean of angular distance (ar-go-me) was significantly higher in thalassemia (133±4) mm compared to controls (129±4) mm, the mean of the angle (sna) no significant affected because the mean value in thalassemia (80.5±0.4) mm and in control (80.1±0.4) mm, the mean of the angle (snb) was significantly lower in thalassemia (73.1±3) mm compared to controls (76.1±3) mm, the mean of the angle (anb) was significantly increase in thalassemia (7.6±3.2) mm compared to controls (2.4±3.2) mm. table(2) & figure (4) j bagh college dentistry vol. 25(4), december 2013 cephalometric analysis oral diagnosis 41 table 1: the case-control differences in mean of selected linear measurements. measurements controls cases thalassemia p (t-test) difference in mean angle (ar_go_me) <0.001 4 range 128-136 128-138.1 mean 129 133 sd 1.4 2.7 se 0.22 0.43 n 40 40 angle sna 0.4[ns] 0.4 range 72-87 76-84 mean 80.1 80.5 sd 2.3 1.9 se 0.37 0.3 n 40 40 angle snb <0.001 -3 range 70.8-78 70-76 mean 76.1 73.1 sd 2.1 1.5 se 0.34 0.24 n 40 40 angle anb <0.001 3.2 range 1-10.4 3-12.8 mean 4.4 7.6 sd 2.7 2.2 se 0.42 0.35 n 40 40 figure 3. dot diagram with error bars showing thecase-control difference in mean (with its 95% confidence interval) of selected linear measurements. 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 lin ea r d ist an ce (g o_ me ) m m lin ea r d ist an ce (a r_g o) mm lin ea r d ista nce (s _g o) mm lin ea r d ista nc e ( n_ me ) m m study group controls cases (thalassemia) j bagh college dentistry vol. 25(4), december 2013 cephalometric analysis oral diagnosis 42 table 2: the case-control difference in mean of selected angular measurements. linear distance (go_me) mm partial regression coefficient p (constant) 68.6 <0.001 age in years 0.60 <0.001 male gender compared to female -1.05 0.06[ns] having thalassemia compared to controls -7.50 <0.001 linear distance (ar_go) mm partial regression coefficient p (constant) 40.7 <0.001 age in years 0.34 <0.001 male gender compared to female 0.22 0.56[ns] having thalassemia compared to controls -3.20 <0.001 linear distance (s_go) mm partial regression coefficient p (constant) 72.6 <0.001 age in years 0.21 0.06[ns] male gender compared to female 0.63 0.21[ns] having thalassemia compared to controls -6.29 <0.001 linear distance (n_me) mm partial regression coefficient p (constant) 118.9 <0.001 age in years 0.31 0.013 male gender compared to female 1.33 0.016 having thalassemia compared to controls -6.55 <0.001 figure 4. dot diagram with error bars showing the case-control difference in mean of selected angular measurements. table 4: effect of age and gender on skeletal angular measurements by using multiple linear regressions. angle (ar_go_me) partial regression coefficient p (constant) 123.6 <0.001 age in years 0.47 <0.001 male gender compared to female -0.43 0.33[ns] having thalassemia compared to controls 4.19 <0.001 angle sna partial regression coefficient p (constant) 76.3 <0.001 age in years 0.34 0.001 male gender compared to female -0.43 0.35[ns] having thalassemia compared to controls 0.52 0.24[ns] angle snb partial regression coefficient p (constant) 71.8 <0.001 age in years 0.37 <0.001 male gender compared to female -0.24 0.53[ns] having thalassemia compared to controls -2.87 <0.001 angle anb partial regression coefficient p (constant) 4.5 0.005 age in years 0.01 0.95[ns] male gender compared to female -0.39 0.49[ns] having thalassemia compared to controls 3.15 <0.001 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 angle (ar_go_me) angle sna angle snb angle anb study group controls cases (thalassemia) j bagh college dentistry vol. 25(4), december 2013 cephalometric analysis oral diagnosis 43 discussion the result show that all selected skeletal linear and angular measurements are not significantly different of level (p>0.05) for both thalassemic males and females. these findings come in agreement with the findings of bassimitci, abu– al-haija (8,14) and moutaz (10)who found that the same results that thalassemic males and females posses no significant differences. it is indicate statistically no significant difference in sna angle between thalassemic (80.5±0.4mm) and controls (80.1±0.4mm). the finding comes in agreement with the findings of bassimitci, abu–al haija(8,14) and moutaz (10)who found that there were insignificant increase in tendency to sagittal maxillary over growth was observed and the anterio-posterior position of the maxilla in relative to cranial base are not different indicating that other variables are responsible for the occurrence of discrepancy, there is statistically significant reduction in snb angle in thalassemic patient (73.1±3mm) compared to controls (76.1±3mm). this finding coincides with agreement with moutaz (10) and disagreement with bassimitci (8) and abu–al haija (14)according to these findings the thalassemic patients exhibited significantly retrognathia in the mandible, anb angle highly significant increased in thalassemic patients (7.6±3.2mm) compared to controls (2.4±3.2mm). (normal limit 2-4mm).this finding coincides with the findings of bassimitci (8) and abu–al haija(14) and moutaz(10). according to this finding the thalassemic patients exhibited a large intermaxillary discrepancy since that the anb angle produced cl11 skeletal pattern, there is a significant increase in gonial angle which is in thalassemic patients (133±4mm) compared to controls (129±3mm). this finding comes in agreements with the findings of bassimitci(8) and moutaz(10), this increase in the measurement of gonial angle indicates more of a tendency to posterior rotation of the mandible with condylar growth directed posteriorly. the mandibular body length (me-go) is significantly decreased in thalassemic patients (67.6±7.7mm) compared to controls (75.3±7.7mm). these findings come with agreement with bassimitci (8) and abu–al haija(14)and moutaz (10). the results indicate that the mandible is unusually short, there is a highly significant difference with shorter total anterior facial height for thalassemic patients (116.5±6.7mm) compared to controls (123.2±6.7mm). this finding comes with agreement of moutaz (10) and disagreement with bassimitci (8) and abu– al haija (14) who found that thalassemic patients have a shorter total anterior facial height with no significant difference, the total posterior facial height significant decreased in thalassemic patients (67.6±7.7mm) compared to controls (75.3±7.7mm). this finding coincides with bassimitci, abu–al haija (8,14), and moutaz (10); found that thalassemic patients possess shorter posterior facial height but is not significantly different. the posterior facial height is largely determined by growth at the condyle, which is deficient probably due to anemia. references 1. silling g, moss, sj. cooley’s anemia orthodontic and surgical treatment. am j orthod 1978; 74(4):444-9. 2. mazza jj. manual of clinical hematology. 3rd ed. lippincott williams and wilkins; 2001. 3. patil s. clinical and radiological study of orofacial manifestations in thalassemia. a master thesis, radiology, the rajiv gandhi university and health sciences, india, 2006. pp. 2. 4. forget bg. thalassemia syndrome. in hematology: basic principles and practice, 3rd ed. new york: churchill livingstone; 2000. pp.485. 5. aster jc. the hemopoietic and lymphoid system. in: robins basic pathology. 7th ed. st. louis: w.b. saunders; 2003. pp. 421-77. 6. benz ej. clinical manifestations of the thalassemia, april up to date, www.uptodate.com.2001 7. cannell h. the development of oral and facial signs in b-thalassemia major. br dent j 1988; 164: 50-1. 8. bassimitci s, yucel-eroglu e, akalar m. effects of thalassemia major on components of the craniofacial complex. br j orthod 1996; 23: 157-62. 9. hes j, van der waal i, de man k. bimaxillary hyperplasia: the facial expression of homozygons ß thalassemic. oral surg oral med oral pathol 1990; 69: 185-90. 10. moutaz takriti, maysson d. craniofacial parameters of syrian children with ß-thalassemia major. j clinical dent 2011; 2:135-43. 11. mills jre. principles and practice of orthodontics. 2nd ed. churchill-living stone; 1987. pp. 72-5. 12. bishara se. textbook of orthodontics. 1st ed. st. louis: w.b. saunders company; 2001. 13. yitschaky o, redlich m, abed y, faerman m, casap n, hiller n. comparison of common hard tissue cephalometric measurements' between component tomography 3d reconstruction and conventional 2-d cephalometric images. angle orthod 2011; 81(1): 138. 14. abu–al haija, esj, haitab faiez, n, al omari ao. cephalometric measurement and facial deformities in subjects with ßthalassemic major. eur j orthod 2002; 24: 9-19. http://www.uptodate.com.2001 sazan f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 radiopacity of modified restorative dentistry 18 radiopacity of modified microhybrid composite resin: (an in vitro study) sazan sh. saleem, b.d.s., m.sc. (1) salem a. al-samarai, b.d.s., h.d.d., ph.d. (2) dara h. saeed, b.d.s., m.sc., ph.d. (3) abstract background: the aim of this study was to measure the radiopacity (ro) of modified microhybrid composite resins by adding 2 types of nanofillers (zinc oxide and calcium carbonate) in two concentrations 3% and 5% and comparing them to unmodified microhybrid composite resins and to nanofilled composite resin. materials and methods: two types of composite resin were used (microhybrid composite mh quadrent anterior shine and nanofilled composite resin filtek z350 xt), for each tested group five disk-shaped specimens (1-mm-thick and 15 mm diameter) were fabricated. the material samples were radiographed together with the aluminum step wedge. the density of the specimens was determined with a transmission densitometer and was expressed in term of equivalent thickness of aluminum. data analyzed by one-way anova. results: the radiopacity (ro) values of the tested group ranged between (0.92932.6242 eq. al thickness) and there were significant differences among them. nanofilled composite resin filtek z350 xt showed the highest value of ro while unmodified microhybrid composite mh quadrent anterior shine showed the lowest value of ro. conclusion: the addition of 3% of both the zno and caco3 nanofillers fillers to microhybrid composite significantly increased the ro, while the addition of 5% of caco3 and zno nanofillers to microhybrid composite showed nonsignificant increase in the ro of the composite. key words: resin composite, radiopacity, aluminum, densitometer. (j bagh coll dentistry 2013; 25(special issue 1):18-22). introduction the current trend in modern resin based composites (rbcs) of minimizing filler size whilst aiming to improve the filler loading has sought to optimize the resultant mechano-physical properties and clinical performance. the introduction of so-called ‘nanofilled’ and ‘nanohybrid’ materials therefore appears a logical continuation of this trend. by definition, a ‘nanomaterial’ possesses components and/or structural features, such as fibres or particles, with at least one dimension in the range of 1-100nm and subsequently demonstrates novel and distinct properties (1,2) one of the most desirable properties of any dental restorative materials is radiopacity, a property that facilitates the radiographic diagnoses adjacent to dental composites and enables better radiographic detection of secondary caries which is the cause for up to half of all operative dentistry procedures performed on adults. furthermore, radiopaque materials enable the clinician to evaluate restoration integrity at following recall appointments, to detect voids, secondary caries, overhangs and open margins (3-5). (1)ph.d. student. college of dentistry, hawler medical university. (2)professor. college of dentistry, hawler medical university. (3) lecturer, college of dentistry, hawler medical university. quadrent anterior shine is a microhybrid composite resin commonly used for anterior teeth. it had a low radiopacity. to enhance its radiopacity and to be use it for posterior teeth, certain modification should be investigated. accordingly this study was designed to evaluate the radiopacity of previously mentioned composite after the addition of nano-sized fillers of calcium carbonate and zinc oxide in two different concentrations. further studies to evaluate the other properties (other physical properties, mechanical and antibacterial properties) are in progress, and will be published as soon they are completed. materials and methods materials two commercial composite resins (microhybrid composite mh quadrent anterior shine, nanofilled composite resin filtek z350 xt) were used in this study. two types of coated nanofillers (calcium carbonate and zinc oxide) both were added to the microhybrid composite. the commercial name, composition and manufacturer of all materials used in this study are listed in table (1). led (bluephase c5, ivoclarvivadent] at 400 m w/ cm² was used in this study. methods preparation of the composite resin specimens a universal microhybrid commercial composite resin was used as control material and blended with the inorganic nanoparticles. a j bagh college dentistry vol. 25(special issue 1), june 2013 radiopacity of modified restorative dentistry 19 commercial universal nanofilled composite was used as a reference to compare with the nanoparticle-blended experimental composites (6,7). addition of caco3 and zno nanoparticles the caco3 and zno nanoparticles treated with silane coupling agent were manually added to microhybrid rbcs in a dark room, at four different weight concentrations: 3% caco3, 5%caco3, 3% zno and 5% zno. the mixture will then thoroughly blended by speed mixture device (karnavati, india) in college of pharmacy/hawler medical university. before curing, the resulting paste packed into teflon molds using an oscillator to remove pores, and covered on both sides with a clear glass plate (6, 7, 8). groups design: six groups of samples denoted mh, n, c3, c5, z3 and z5 were defined. the nanoparticle type and weight ratio characterizing of each group are shown in figure 1. each of these groups was subjected to radiopacity test evaluation. table 1: the commercial name, the composition and manufacturer of the materials used materials composition manufacturer filtek z350 bis-gma, udma, tegdma,, bis-ema fillers (78.5%w, 59.5% v): combination of nonagglomerated/ nonaggregated 20 nm silica filler, nonagglomerated/ non aggregated 4-11 nm zirconia filler, aggregated zirconia/silica cluster filler. 3m espe, st paul, mn, usa quadrant anterior shine bis-gma, acrylates fillers (75.6% w, 63%v) barium glass, silica, silicate glass, fluoride containing fillers (0.7 µm), polymerization crystal, in-organic pigment cavex holland bv, haarlem, the netherlands zinc oxide nanofillers zno nanofiller with (10-30 nm) coated with silane coupling agent (nh2ch2ch2ch2si(oc2h5)3 skyspringnanomaterials, inc. usa calcium carbonate nanofillers (caco3) nanofillers (80 nm) coated with silane coupling agent m k impex corp. canada figure 1: diagrammatic illustration of experimental design of groups for the study. radiopacity evaluation five specimens for each group were prepared in the form of disks 15 mm in diameter and 1 mm thick. each sample was placed on cassette film 20 × 25 cm in size with the aluminum step-wedge as a standard to compare the radiodensity (fig.2). the radiographic exposure was done using an xray unit machine (axiom, iconos-r100, siemens, germany), operated for 0.5 s at 60 kv and 1 ma the film-object distance was 40 cm. the radiographs film was developed and the optical density of radiographic film was analyzed with a transmission densitometer. the measured value was converted in terms of the equivalent thickness of aluminum by referring to the calibration curve for the radiographic density of an aluminum step-wedge (9). nanofilled composite filtek z350 xt(reference material) (n) 3% zno np (z3) 5% zno np(z5) 3% caco3 np(c3) conventional microhybrid composite addition of zno np conventional microhybrid composite. (quadrent anterior shine) (control) (mh) groups 5% caco3 np(c5) addition of caco3 np j bagh college dentistry vol. 25(special issue 1), june 2013 radiopacity of modified restorative dentistry 20 figure 2: (a) one specimen from each tested material, and al step wedge positionedon film cassette. (b) representative developed radiograph of the specimens and al step wedge. statistical analysis the means and standard deviations for optical densities (od) of the specimens and aluminum step wedge of each radiograph were calculated by averaging the three repeated measurements to create a single value for each specimen. a linear regression analysis was calculated for each film, relating the od of the steps in the wedge to the thickness of each step. the aluminum equivalent (al) was then calculated for each sample by using the regression analysis equation of: y = a + bx, where: y = the optical density (od) of the specimen; a = the coefficient of the regression; b = the regression constant and x = the aluminum equivalent value for that sample. descriptive analysis, one-way anova and duncan test were used to determine statistical significance of radiopacity among the materials. results the means and standard deviations of the radiopacity value of the tested materials are shown in table 2 and figure 3. according to the international standards organization (iso) 4049, the radiopacity of a 1.0 mm thick composite specimen should be equal to or greater than the same thickness of aluminum. only the mh group did not meet this criterion (0.9293 al eq.) which had the lowest radiopacity value and it is significantly different from the other groups. the addition of 3% of caco3 and 3% zno to the microhybrid composite (mh) significantly increase its radiopacity. while the addition of 5% of caco3 and 5% zno to the microhybrid composite (mh) increase its radiopacity but they were statistically not significant. . the obtained result showed that the n group (nanohybrid composite resin) had the highest radiopacity (2.6242 al eq.) which is significantly different from the other groups. table 2: means and standard deviations of the radiopacity of the tested materials groups n mean s.d. s.e. 95% confidence interval for mean minimum maximum lower bound upper bound mh 5 0.929387 a .0707107 .0316228 .841588 1.017186 .8294 1.0294 n 5 2.624296 d .7071068 .3162278 1.746307 3.502285 1.6243 3.6243 z3 5 1.773314 bc .0642417 .0287298 1.693548 1.853081 1.6743 1.8543 z5 5 1.0940 a .0120181 .0053747 1.068366 1.098211 1.0706 1.0953 c3 5 1.566230 b .1238230 .0553753 1.412484 1.719977 1.4944 1.7803 c5 5 1.083289 a .0120181 .0053747 1.068366 1.098211 1.0706 1.0953 zc 5 2.083573 c .0378716 .0169367 2.036549 2.130597 2.0593 2.1457 total 35 1.591911 .6322689 .1068730 1.374719 1.809103 .8294 3.6243 note: means with different letter indicated statistically significant (p<0.05). a b j bagh college dentistry vol. 25(special issue 1), june 2013 radiopacity of modified restorative dentistry 21 figure 3: bar chart for the means of radiopacity of tested materials discussion radiopacity of a material can be simply defined as the inverse of the optical density of a radiographic image. optical density value is a logarithmic measure of the ratio of the transmitted-to-incident light through the film image, measured by the transmission densitometry, it depend on the inherent x-ray absorption properties of the materials (10,11). radiopacity depends in part on selection of the polymer matrix, chemical nature of the filler particles, their size, density and an amount in the resin matrix, while resin matrices contribute little to the radiopacity of the material, it is typically the inorganic filler component that contributes most to the radiopacity of resin-based luting materials (11). according to the international standards organization (iso) 4049, the radiopacity of a 1.0 mm thick composite specimen should be equal to or greater than the same thickness of aluminum to be deemed radiopaque which is close to that of human dentin (3-5).in order to make comparisons between the different studies possible, aluminum step-wedge was chosen as a standard for measuring radiopacity, because its linear absorption coefficient (µ) is the same order as dental enamel (12,13). according to the results of this study all the tested groups met the criteria of (iso) 4049 except the mh group (0.9293 al eq.) which had the lowest radiopacity value and it is significantly different from the other groups. this might be due to the fact that this material contains sio2 (which are not radiopaque fillers) and a small percentage of ba-f-si fillers in its formulation (table 1), in addition f and si fillers had low atomic number which were: 9,14 respectively (4). this result agrees with the study of sabbagh et al. 13. this can be explained in accordance with the manufacturer’s propositions, that this composite material should be used only for anterior restorations. on the other hand filtek z 350 xt composite resin (n group) showed the highest radiopacity value (2.6242 al eq.) which is significantly differ from the other groups, this is contributed to high fillers content of this composite and in addition to the presence of zirconium in its filler composition (table 1) which are radiopaque fillers and it’s a high atomic number element (zr=40). c3 and z3 groups showed significantly higher radiopacity value compared to mh group and they were not significantly differing from each other. this could be due to the fact that zinc in zno nanoparticle had a high atomic number (zn=30) and calcium in caco3 had a high atomic number (ca= 20), while z5 and c5 groups had lower ro value than z3 and c3 with statistical significant difference. this might be attributed to the fact that incorporation of higher percentage (5%) of the particles into microhybrid composite act as light scatterers, hindering light penetration at depth, especially particles with a size that approaches the output wavelength of the light-curing unit. our result is agree with the study of hewett et al. (15) who incorporated calcium carbonate fillers in different weight to make resin teeth more radiopaque, the result showed that the radiopacity increase by increasing the weight to 18gm then the ro value decline. also agrees with the study of moldovan et al. (16) who incorporated zno into composite resin in two different concentrations. the result showed that zno fillers have benefit effect on radiopacity, but the radiopacity was decreased as the concentration increased. finally variation in radiopacity measurements among different studies depends on a number of factors, including speed of the x-ray film, exposure time, voltage used and the age of the developing, fixing solutions, source-film distance, intensifying screens and specimen used (11). as a conclusion; the addition of 3% of both the zno and caco3 nanofillers fillers alone or in combination to microhybrid composite significantly increased the ro, while the addition of 5% of caco3 and zno nanofillers to j bagh college dentistry vol. 25(special issue 1), june 2013 radiopacity of modified restorative dentistry 22 microhybrid composite showed non-significant increase in the ro of the composite. references 1. harris j, ure d. exploring whether ‘nano’ is always necessary. nanotechnology perceptions 2006; 2: 1-15. 2. lui h, webster tj. nano-medicine for implants: a review of studies and necessary experimental tools. biomaterials 2007; 28: 354-369. 3. cruvinel dr, garcia l, casemiro l, pardinid l, piresde-souza f. evaluation of radiopacity and microhardness of composites submitted to artificial aging. mater res 2007; 10(3): 325-329. 4. dukici w, delija b, derossi d, dadici i. radiopacity of composite dental materials using a digital x-ray system. dent mater j 2012; 31(1): 47–53. 5. hitij t, fidler f. radiopacity of dental restorative materials. clin oral invest springer 2012: 1-11 6. xia y, zhang f, xie h, gu n. nanoparticle-reinforced resin-based dental composites. j dent 2008; 36: 450 455. 7. sevinc b, hanley l. antibacterial activity of dental composites containing zinc oxide nanoparticles. j biomed mater 2010; 94b: 22–31. 8. beyth n, farber iy, bahir r, domb a, weiss a. antibacterial activity of dental composites containing quaternary ammonium polyethylenimine nanoparticlesagainst streptococcus mutans. biomaterials 2006; 27: 3995–4002. 9. international organization for standardization. iso 4049: 2000. dentistry polymer-based filling, restorative and luting materials. 3rd ed. geneva, switzerland: international organization for standardization; 2000. 10. el-mowafy om,benmergui c. radiopacity of resinbased inlay luting cements. oper dent j 1994; 19: 1115. 11. pekkan g, özcan m. radiopacity of different resinbased and conventional luting cements compared to human and bovine teeth. dent mater j 2012; 31(1): 68–75. 12. cook wd. an investigation of the radiopacity of composite restorative materials. austral dent j 1981; 26(2):105-112. 13. sabbagh j, vreven j, leloup g. radiopacity of resin based materials measured in film radiographs and storage phosphore plate (digora). oper dent 2004; 29 (6): 677-684. 14. furtos g, baldea b, silaghi-dumitrescu l, moldovan m, prejeran c, nica l influence of inorganic filler content on the radiopacity of dental resin cements. dent mater j 2012; 31(2): 266–272. 15. hewett j, zhao d, chan d, ganter m, wataha j. radiopacity of resin formulations with calcium carbonate filler. iadr conferencerean. 2013. 16. moldovan m, prejme c, borzea d, nicola c, sava s. filler systems, interface, radiopacity of some new lightcuring composite material. eur cell and mater 2005; 9(1): 7-8. 19. rasim f.doc j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 110 immunohistochemical study of pdgf, igf of radiated tooth rat embryo rasim mahdi salih, b.d.s, d.o.d. (1) athraa y al-hijazi, b.d.s., m.sc., ph.d. (2) abstract background: exposure to microwaves radiation from microwave oven may be harmful for users especially for the one who have highest contact with microwave oven. because the body is electrochemical in nature, any force that disrupts or changes human electrochemical events will affect the physiology of the body by destabilization and interruption of many chemical body substance including growth factors.the insulin-like growth factors (igfs) are a family of mitogenic proteins that control growth, differentiation, and the maintenance of differentiated function in numerous tissues. it fulfils an important role in growth and development of teeth, mandible, maxillae, and tongue. platelet derived growth factors (pdgf) are proteins that regulate cell growth and division. in particular, it plays a significant role in blood vessel formation (angiogenesis). it seems that igf and pdgf share in much tissue developmental process. therefore they included in the present study in correlation to tooth growth & development. this study illustrates the expression of insulin like growth factor and platelet derived growth factor by dental cells of rat embryos at periods of gestation 16th,18thday intrauterine life(i.u.l) and one day neonatal life. materials and methods: animal model: thirty-six female rats were used in this study .starting from zero days (time of gestation that recorded) the pregnant rats were divided into three groups. group a serve as a control, groups b exposed to microwave oven radiation for (15 /minutes; 5/min /hour for 3 hours continuously) daily and c exposed to emf radiation for (45 minutes ;15 min /hour for3hours continuously)daily starting from zero day of gestation till the last day. the embryo of rats at 16thday and 18th day of intrauterine life and one day old rat (new born rat) were studied immunohistochemically for localized of platelet derived growth factor (pdgf) and insulin growth factor (igf) markers. results:the results showed that experimental group (b) exposed to short duration of radiation (5/ min.) stimulates the development of tooth germ and faster tooth growing in comparison to control with immunohistochemical results show strong to moderate intense stain for positive expression of growth factors(pdgf,igf) by dental tissue.for long exposure period of radiation( group c) , it showed retardation in the tooth growth withimmunohistochemical findings record weak to negative intense stain for the expression of growth factors(pdgf,igf) by dental tissue. conclusion: exposure to microwave (oven) radiation during pregnancy may play a role in the expression of igf and pdgf by cells of tooth germ thatinfluence on cell differentiation and physiological activity of specialized dental cells, depending on exposure time. key words: pdgf, igf, immunohistochemical study. (j bagh coll dentistry 2013; 25(1):110-115). introduction radiofrequency (rf) electromagnetic waves may interact with biological tissue through a number of mechanisms (1). radiofrequency interaction can take place through thermal or non -thermal mechanisms. thermal mechanisms are those resulting from the temperature change of the tissue caused by the rf fields. all interactions between rf fields and biological tissue are likely to result in energy transfer to the tissue and this will ultimately lead to an increase in its temperature. but non-thermal mechanisms are those that are not directly associated with this temperature change but rather to some other change produced in the tissue by the electric or magnetic field (2). sensitivity to electromagnetic fields varies between people, due to known and unknown reasons, including past exposures; cumulative exposure; duration and intensity of exposures; presence of heavy metals, chronic infections, dental amalgams and other stressors; differences in detoxification capacities; etc. (1) master student, ministry of health. (2) professor, department of oral histology and biology, college of dentistry, university of baghdad. overtime, and with increasing exposure, more people feel the effects of electromagnetic fields (3). oral tissues are important part of the body that absorbs radiation. many studies illustrate the effect of rf on the role of growth factors that concerned with oral tissue such as the role of igf system and pdgf in growth regulation of salivary gland cell, periodontium and in tooth growth and development (4). materials and methods thirty six pregnant albino female rat (2-3 months of age, 900 -1000 gram of weight) were used in the present experiment, divided into three groups: 1-control group a: consist of 12 pregnant rats, not exposed to microwave oven radiation. 2-experimental group b: consist of 12 pregnant rats exposed to microwave oven radiation for (15 minutes; 5 min /hour for 3 hours continuously) daily at specific time during (lightperiod) starting from zero gestation till the day of scarifying. 3-experimental group c: consist of 12 pregnant rats exposed to micro wave oven radiation for (45 minutes; 15 min /hour for 3 hours continuously) daily on specific time during (light period) j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 111 starting from zero tome of gestation till the day of scarifying. premaxilla (contain incisor teeth) of rat embryos at 16thday, 18th day iul and one day neonatal rat were fixed in 10%buffered formalin and studied for immunohistochemical localization of platelet derived growth factor-a andinsulin-like growth factor i(e-10)santa cruz biotechnology,inc. with detection kitsanta cruz biotechnology, using of primary antibodies, then staining systems include :normal blocking serum 1.0 ml.,biotinylated secondary antibody 250 mg. ,avidin and biotinylated horseradish peroxidase(ab reagents) 0.5 ml each .,peroxidase substrate 1.0 ml 50x., dab chromogen 1.0 ml 50x .,substrate buffer 3.0 ml 10x. results immunohistochemical results insulin growth factor (igf). at 16th day iul positive expression of igf was detected in the dental lamina and oral epithelia in control (group a) and group c while group b shows positive expression in dental sac too, figures (1,2,3). figure1: immunohistochemical view for tooth germ of rat (16thday i.u.l) control.shows positive expression for igf in dental lamina (dl) and mitotic cell(arrow).dab with counter stain hematoxylin×100 figure 2: view for positive expression of igf in tooth germ of rat (16th day i.u.l) treated (group b) shows positive brown color in dental lamina ,oral ectoderm cell(oe)and dental sac (ds). dab with counter stain hematoxylin×100 figure 3: immunohistochemical view for express igf in oral ectoderm and dental lamina of tooth germ in bud stage of rat(16th day i.u.l) treated (group c).dab with counter hematoxylin×100 at 18 day iul: positive expression of igf was illustrated by inner enamel epithelium, outer enamel epithelium ,dental lamina and dental sac in groups a and b. while group c shows weak expression of igf in dental lamina and negative expression in dental papilla .figures (4,5,6). figure 4: immunohistochemical view for tooth germ of rat (18th day iul) control shows positive expression of igf in inner enamel epithelium(iee), outer enamel epithelium (oee), dental lamina(dl).dab with counter stain hematoxylin×200. j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 112 figure 5: immunohistochemical view for tooth germ of rat (18thday iul)(group b) shows moderate positive expression of igf by oral ectoderm(oe),dental sac (ds) and dental papilla(dp). dab with counter stain hematoxylin×100. figure 6:immunohistochemical view of tooth germ of rat (18thday iul)( group c) shows weak expression of igf in dental lamina. dab with counter stain hematoxylin×100 at one day neonatal lifepositive expression of igf was illustrated in stratum intermedium ,odontoblast ,ameloblast and dental pulpin groups a and b . while group c shows faint stain for igf that is hardly expressed by odontoblast and in bone overlying tooth germ, figures(7, 8, 9). figure 7: immunohistochemical view for tooth germ of rat (1 day old) control. shows positive expression of igf by stratum intermedium (si),odontoblast (od),ameloblast (ab) and dental pulp(p).dab with counter stain hematoxylin×200 figure 8: immunohistochemical view for tooth germ of one day old rat (group b) shows positive expression of igf by odontoblast (od),ameloblast(ab) and predentin(pd).dab with counter stain hematoxylin×400 figure 9: immunohistochemical view of tooth germ of one day old rat (group c) shows faint dab stain for localization of igf,it hardly expressed by odontoblast(od) .dab with counter stain hematoxylin×100. expression of platelet derived growth factor: at 16 day iul.controlgroupashows positive expression of pdgf by oral ectoderm and proliferating cells ectomesenchymal cells of tooth germ figure (10). group b shows positive expression of pdgf by dental lamina, dental papilla and dental sac,figure (11).while group cillustrates faint positive stain in tooth germ figure (12). j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 113 figure 10:immunohistochemical view of tooth germ of rat (16th day i.u.l) control. shows positive pdgf expression by oral ectoderm (or), proliferation central cell (arrow) and ectomesenchymal cell (em).dab with counter stain hemotoxylin× 200. figure 11: immunohistochemical view of tooth germ of rat (16th day i.u.l) (group b).shows positive pdgf expression by dental lamina (dl) and dental papilla (dp).dab with counter stain hematoxylin×200 figure 12: immunohistochemical view of tooth germ of rat (16th day i.u.l) (group c).shows faint (weak) positive reaction of tooth germ in bud stage(arrow) for pdgf.dab with counter stain hematoxylin×100. at 18thday i.u.l.control group a illustrates positive reaction in dental lamina ,apical loop and strong positive in bone formation area of dental sac and outer enamel epithelium,figure (13 ).group b shows positivity in oral ectoderm,outer enamel epithelium, inner enamel epithelium, dental lamina, dental sac area and newly bone ,figure(14).while group c shows positive stain at cusp region ,figure (15). figure 13: immunohistochemical view for detection of pdgf expression in tooth germ (bell stage) of rat (18thday i.u.l) control .show positive of dab stain in dental lamina and apical loop (arrow).dab with counter stain hematoxylin×200. figure 14: immunhistochemical view for detection of pdgf expression in tooth germ (at bell stage) of rat 18thday i.u.l (group b).shows positivity for oral ectoderm (or), outer enamel epithelium (oee) and inner enamel epithelium (iee).dab with counter stain hematoxylin×200. em or j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 114 figure 15: immunohistochemical view for detection of pdgf expression in tooth germ of rat 18thday iul (group c).shows positivity of cusp region (arrow).dab with counter hematoxylin×200. at one day neonatal life control groupashows positive reaction in odontoblast and bone ,figure (16). group b shows positive reaction in odontoblastpredentine, ameloblast, stratum intermedium , stellate reticulum ,tom's process and pulp cell expressed positive pdgf by fibroblast and mesenchymal cell figure (17 ). group c illustrates weak reaction in odontoblast and ameloblast cell layer and negative expression in dental pulp, figure (18). figure 16: immunohistochemical view for pdgf expression in tooth germ of one day old rat (control group).show positive reaction inodontoblast(od) ,bone (b).dabwith counter stain hematoxylin×200. figure 17: immunohistochemical view for pdgf expression in tooth germ of one day old rat (group b).shows positivity in odontoblast (od), predentine(pd),ameloblast(ab),stratum intermedium (si), toms process(tp) and stellate reticulum(sr).dab with counter stain hemayoxyline×400. figure18immunohistochemical view of pdgf expression in tooth germ of one old rat (group c).shows weak reaction in odontoblast and ameloblast cell layer with negative expression in dental pulp (p), except bone (b) shows positive reaction.dab with counter stain hematoxylin×100. discussion expression of igf in developing dental tissue of control and experimental groups. the igf system plays a role in the formation of the mandible and teeth(5) and participates in the regulation of bone metabolism. it has been proposed that igf-i functions as an autocrine/paracrine regulator of tooth development and influences cell differentiation and the physiological activity of specialized dental cells(6). in the present study expression of igf appeared as strong and weak intensity in different study groups and in different periods that matched the level of the expression of igf marker. j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 115 thesedata suggest that the igf system likely participates in more than one process during tooth development (7). this result could be explained: 1-during tooth development each mitotic cells related to enamel organ ,dental papilla or dental sac were under go repeated changes in the morphology and function that obviously detected in life cycle of specialized cells include ameloblast and odontoblast ,these modulation process that occur normally may implicated by igf system . 2-short exposure of microwave radiation in 5/min.group b suggest to enhance igf system which considered a pleiotropic acting as both mitogen and differentiation factors promoted the acceleration in the differentiation of development of ameloblast, endothelial cells. in group c ,dental cells appear weak (faint) to negative reaction due to retardation and decrease the mitogen role of igf with poor differentiation and specialization of these cells, or may be retarded by growth hormone insensitivity or lack of growth hormone receptor response. long exposure to radiation may increase the stress status and hormonal changes like oestrogen status, so, effected the secretion and amount of igf and response to reaction withantibody, therefore, it appears faint or negative. expression of pdgf in developing dental tissue of control and experimental groups platelet derived growth factor (subunits a and -b) are important factors regulating cell proliferation, cellular differentiation and cellgrowth, and it plays a significant role in blood vessel formation (angiogenesis)(8). positive reaction for pdgf was detected in proliferating central cells, ectomesenchymalcell, oral ectoderm, dental lamina and dental sac in control and group b at 16thday ,18th day i.u.l, these findings illustrated that pdgfs are mitogenic during early developmental stages, drivingthe proliferation of undifferentiated mesenchyme and some progenitor populations. and during later maturation stages, pdgf signaling has been implicated in tissue remodeling and cellular differentiation, and in inductive events involved in patterning and morphogenesis (9) . strong expression of pdgf in the cusp region during morphogenesis play important role in growth, differentiation and morphogenesis, but, it showed to be negative after complete tooth differentiation and morphogenesis (10). furthermore, pdgf positive expression during control and short duration of emf radiation as these radiation may increase the role of pdgf in angiogenesis and enhance the growth and development .the faint expression of pdgf in group c at development stage of rat tooth germ may due to long duration of radiation that retard the growth by effecting on pdgf receptor response. references 1. challis lj. mechanisms for interaction between rf fields and biological tissue. bio electromagnetics. 2005; suppl 7: s98-s106. 2. foster kr. thermal and non-thermal mechanisms of interaction of radio-frequency energy with biological systems. ieee trans plasma science 2000; 28:15–23. 3. rubin j, munshi j, simon w. electromagnetic hypersensitivity: a systematic review of provocation studies ".psychosomatic medicine.2005; 67 (2): 224– 32. 4. sood s, gupta s, mahendra a. gene therapy with growth factors for periodontal tissues.med oral pathol. oral cir bucal 2012; 17(2): e 301-10. 5. werner h, katz j .the emerging role of the insulinlike growthfactors in oral biology. j dent res 2004. 83: 832-6. 6. joseph bk, savage nw, daley tj, young wg. in situ hybridization evidence for a paracrine/autocrine role for insulin-like growth factor-i in tooth development. growth factors1996, 13:11–17. 7. yamamoto t, oida s, inage t. gene expression and localization of insulin-like growth factors and their receptors throughout amelogenesis in rat incisors. j histochemistry & cytochemistry 2006; 54(2): 243-52. 8. joukov v, pajusola k, kaipainen a, saksela o, alitalo k, olofsson b, von euler g, orpana a, pettersson rf, eriksson u. vascular endothelial growth factor b, a novel growth factor for endothelial cells. proc natl acad sci u.s.a.1996; 93(6): 256781. 9. hoch rv, soriano p. roles of pdgf in animal development. development 2003; 130(20): 4769-84. 10. betsholtz c, raines ew. platelet-derived growth factor: a key regulator of connective tissue cells in embryogenesis and pathogenesis. kidney int 1997; 51: 1361-9. j bagh college dentistry vol. 31(4), december 2019 personality types 14 personality types in relation to dental caries and salivary testosterone among teachers in baghdad city raya rashid al-dafaai, b.d.s, m.sc. (1) ban sahib diab, b.d.s, m.sc., ph. d. (2) huda jameel abd alghani, m.a. ph. d. (3) abstract: background: personality could be defined broadly as those characteristics of individuals that describe the pattern of feeling, cognition and behaving. personality types can be measured by using one of personality type’s measures. personality has been proposed to influence the oral health. the purpose of the present study was to assess the influence of personality types on caries experience in relation to salivary testosterone hormone among teachers in baghdad city. materials and methods: female teachers (n=534) of randomly selected schools were subjected to personality questionnaire using the riso-hudson enneagram type indicator. teachers were examined to estimate the caries experience according to the decayed-missing and filled index (dmfs). a group of teachers were randomly selected from the total sample for salivary analysis of testosterone. data were analyzed using spss version 18 software. a probability value less than 0.05 was considered to be statistically significant. results: data analysis showed that the higher percentage of teachers was helpers as the dominant type. the results showed statistical high significant differences in mean values of dmfs among the nine personality types. no significant correlation was found between salivary testosterone concentration (pg /ml) with the scores of the nine personality types. no significant correlation was found between salivary testosterone concentration (pg/ml) and caries experience. conclusions: the identification of personality types and their relations with dental caries can permit the assessment of the individual's susceptibility and facilitate the improvement of the individual's oral health. keywords: personality types, caries experience, salivary testosterone. (received: 15/11/20115; accepted: 13/12/2015) introduction riso and hudson defined personality as “a collection of internal defenses and reactions, beliefs and habits about self and world that have come from childhood experience where the heredity factors predispose child to have certain temperament”. they developed riso-hudson enneagram type indicator (rheti) to be a scientifically validated forced-choice personality types test with 144 paired statements (1). dental caries is “a complex disease caused by a physiological imbalance between fluid and mineral dental biofilm which is also known as plaque” (2). psychological factors have been paid attention in relation to dental caries. during the last decades, researchers tried to find the relationship between caries and personality (3, 4). later on, it was suggested that personality is a risk factor with respect to dental caries and should be considered when using patients’ reports (5). psychological wellbeing and a lack of stress have been attributed to health maintenance. thus, biological factors can be influenced by psychological factors in the development of chronic diseases like dental caries (6). 1. lecturer. department of preventive dentistry, university of baghdad . 2. assist. prof. department of preventive dentistry, university of baghdad . 3. assist. prof. psychological research center, university of baghdad. various factors can influence the experience of stress in the individual like person’s perception of the situation, past experiences, the presence or absence of social support, and individual differences such as motivation, attitudes, and personality (7). stress has been studied in relation to dental caries in different studies (8, 9, 10). it was suggested that the association between stress and prevalence of caries could be attributed to salivary changes in flow rate and composition (11). one of the important effects of stress is the reduction in testosterone production. researches indicated that elevations in cortisol lowered testosterone (12). stressful situations as experienced during work have been shown to decrease testosterone levels (13). the production of testosterone in women is much smaller than in men, but these small amounts have crucial role in the health and well-being of women. testosterone is important in the growth and maintenance of skeletal muscle, and may play a significant role in the maintenance of bone mass and inhibit osteoclastic function (14). testosterone can relieve anxiety and depression, and promotes clearer thinking. low level of this hormone was observed in female with depressive disorder and anxiety disorder (15). no previous study was conducted to determine the effect of different personality types on dental caries and few reports regarding salivary j bagh college dentistry vol. 31(4), december 2019 personality types 15 testosterones have been presented in the dental field (16, 17). this study was designed to investigate the influence of personality types on the caries experience of secondary schools teachers and salivary testosterone concentration. materials and methods the target population of this study was females teachers aged between 29 and 39 years. secondary schools of females were randomly selected in baghdad city, (urban only). riso-hudson enneagram type indicator (rheti), version 2.5, was used to determine the basic personality type and the scores of the nine personality types of human nature for each teacher (1). the (rheti) was translated to arabic and prepared to be used in iraq by al-yassiry in 2004 (18). it requires from each teacher to choose one statement in each pair that best describes her throughout most of life. each chosen statement has a score of one while the non-chosen statement has a score of zero. after collection of the scores, each teacher had nine scores of the nine personality types and each personality type should have a score range (0-32). the total scores for the nine types should equal to 144. the higher score represented the basic personality type for the teacher. caries experience was determined by decayedmissing – filled surfaces (dmfs) index by who (1997) in which all teeth were examined and all third molars were included (19). plain mouth mirror and cpi probe were used in the examination. a group of teachers (87) was randomly selected from the total sample according to the basic personality type for analysis of salivary testosterone. saliva collection, storage and analysis were according to the manufacturer instructions (demeditec diagnostics gmbh, germany). data were statistically analyzed using spss version 18 software. a probability less than 0.05 (p<0.05) was considered to be statistically significant. results a sample of 534 teachers from 55 schools was examined, distributed throughout the six directorates of baghdad city, urban only. the total scores for each personality type were calculated from the indicator sheets. the higher score represented the basic personality type for each teacher. by dividing the total sample according to the higher score for each teacher or the basic personality type, the highest percentage was found for the helper followed by the peacemaker and the achiever personality types while the lowest percentage was for the enthusiast (table 1). the differences in caries experience among teachers according to the basic personality types are revealed in table 2. the results show statistical high significant differences in mean values of dmfs among the nine personality types where the achiever showed the lowest mean of dmfs. further analysis by games-howell test (post hoc) showed that the significant differences in the (decayed, missing, filled surfaces) dmfs were found between the achiever type with the reformer (m.d.=8.03, p value=0.01), the helper (m.d.=11.28, p value=0.00) and the peacemaker (m.d.=12.16, p value=0.00). table 3 is showing the correlation coefficient between the concentrations of salivary testosterone and the scores of the nine personality types. no significant correlations were found between the concentrations of the salivary testosterone and the scores of the nine personality types. no significant correlation (p˃0.05) was also found between the salivary testosterone and caries experience (r=-0.12, p=0.26). table (1): the distribution of the teachers according to the basic personality types basic personality types no. % the reformer 66 12.36 the helper 162 30.34 the achiever 67 12.54 the individualist 20 3.74 the investigator 19 3.56 the loyalist 49 9.18 the enthusiast 14 2.62 the challenger 50 9.36 the peacemaker 87 16.30 total 534 100% j bagh college dentistry vol. 31(4), december 2019 personality types 16 table (2): the differences in caries experience (mean ±se) among teachers according to the basic personality types basic personality types dmfs (mean ±se) the reformer 22.56±1.97 the helper 25.80±1.22 the achiever 14.52±1.06 the individualist 24.80±4.37 the investigator 20.47±2.25 the loyalist 18.51±2.12 the enthusiast 28.86±5.16 the challenger 20.64±2.37 the peacemaker 26.69±1.826 f value 4.85** **highly significant (p≤0.01), df=8 table (3): correlation coefficient between salivary testosterone concentrations (pg/ml) and the scores of the nine personality types scores of personality types testosterone (pg/ml) r p the reformer -0.02 0.79 the helper 0.18 0.08 the achiever -0.04 0.70 the individualist -0.05 0.64 the investigator -0.05 0.61 the loyalist 0.10 0.32 the enthusiast 0.08 0.42 the challenger -0.14 0.18 the peacemaker -0.03 0.73 discussion: since there are no previous studies in iraq on the relationship between personality types and oral health status, this study was conducted to focus on the relation between personality types and caries experience. female teachers were the target group in this study. some caries risk factors may place women at higher risk to develop dental caries. these factors include dietary habits, hormonal fluctuation, genetic variation, differences in saliva composition and flow rate between male and female (20). pregnancy may explain some of gender differences in dental caries due to factors related to the changes in mouth flora and saliva, vomiting, neglected oral hygiene, and nutritional changes (21). however, women have the responsibility of food preparation and easier access to foods and snacks outside of mealtime. psychological factors also may explain caries experience among women as they are more subjected to stress, domestic violence and eating disorders (22, 23). the current study showed significant differences in the decayed, missing and filling surfaces (dmfs) between the achiever type and six personality types: the reformer, the helper, j bagh college dentistry vol. 31(4), december 2019 personality types 17 the individualist, the enthusiast, the challenger and the peacemaker. from the basic description of the achiever personality type, the achievers are healthy, charming, successful, highly concerned with their performance. self-assured, energetic and motivating others (24). this description may lead them to be more concerned in their health status and especially oral health status. the psychological wellbeing and the less stressful personality may have distinctive biological correlates that can benefit health regarding the oral immunity and salivary changes. the study showed no significant correlations were found between the concentrations of the salivary testosterone and the scores of the nine personality types. this result disagrees with the results of other studies that showed positive association between testosterone levels and certain personalities (25, 26). the differences in study design may explain this disagreement. larger sample size may be needed to show the changes in salivary testosterone among women with different personality types. no significant correlation was found between the salivary testosterone and caries experience. previous studies also confirmed that androgens including testosterone have no effect and not positively correlated with caries rates (16, 17). however, few studies were conducted to determine the effect of testosterone on the oral health status and further studies are needed to confirm this finding. references: 1. riso d r, hudson r. understanding the enneagram: the practical guide to personality types. boston, new york: houghton mifflin; 2000. 2. fejerskov o. changing paradigms in concepts on dental caries: consequences for oral health care. caries res 2004; 38(3):182-191. 3. hyams ib. personality factors and dental caries. journal canadian dental association1948; 14(9):473 . 4. manhold jh, rosenberg n. study of the possible relationship of personality variables to dental cavities. j dent res 1954; 33: 357-363 . 5. thomson wm, avshalom c, richie p, terrie e, jonathan m. personality and oral health. eur j oral sci 2011; 119(5): 366–372 . 6. costa1 sm, vasconcelos m, haddad jp, abreu mh. the severity of dental caries in adults aged 35 to 44 years residing in the metropolitan area of a large city in brazil: a cross-sectional study. bmc oral health 2012, 12:25. 7. slocum j w, d hellriegel. fundamentals of organizational behavior. mason, oh: thomson; 2007. 8. marcenes ws, sheiham a. the relationship between work stress and oral health status. soc sci med. 1992; 35(12):1511-1520. 9. mejía-rubalcava c, alanís-tavira j, arguetafigueroa l, legorreta-reyna a. academic stress as a risk factor for dental caries. international dental journal volume 2012; 62(3): 127-131. 10. bhushan k; prabhdeep k sandhu2, dr shaiba sandhu. psychological stress related oral health problemsdental perspective. ijrid 2014; 4 (3). 11. pagare ss, nayak cd, kaur a. to analyze perceived stress and its relation to dental caries: a study. scientific journal 2009; 3. 12. brownlee kk, alex w. moore1 and anthony c. hackney. relationship between circulating cortisol and testosterone: influence of physical exercise. journal of sports science and medicine 2005; 4, 7683. 13. m zitzmann m, nieschlag e. testosterone levels in healthy men and the relation to behavioral and physical characteristics: facts and constructs. european journal of endocrinology 2001; 144: 183197. 14. kasperk ch, wakley g, hierl t, ziegler r. gonadal and adrenal androgens are potent regulators of human bone cell metabolism in vitro. j bone miner res 1997; 12:464-471. 15. giltay ej, dorien e b, frans g. zitman a, brenda wjh, et al. salivary testosterone: associations with depression, anxiety disorders, and antidepressant use in a large cohort study. journal of psychosomatic research 2012; 72: 205-213. 16. delman la. effect of gonadectomy on dental caries: review of the literature. j am dent assoc 1955; 51:155–158. 17. laine m, tenovuo j, lehtonen op, ojanotko-harri a, viljap, tuohimaa p. pregnancy-related changes in human whole saliva. arch oral biol 1988; 33:913– 917. 18. al yassiry m. the nine personality types of the enneagram. master thesis submitted to the college of education, university of baghdad, 2004. 19. world health organization (who): oral health surveys, basic methods. 4th ed. geneva; 1997. 20. halpern lr, kaste lm. evidence-based women's oral health, an issue of dental clinics. elsevier health sciences 2013. 21. silk h, douglass a, douglass jm, silk l. oral health during pregnancy. am fam physician 2008; 77(8):1139-1144. 22. ferraro m and vieira ar. explaining gender differences in caries: a multifactorial approach to a multifactorial disease. international journal of dentistry 2010; 2010: 5 pages. 23. lukas jr, largaespada ll. explaining sex differences in dental caries prevalence: saliva hormones and life history etiologies. am j hum biol 2006; 18: 540-555 24. riso d r, hudson r. the wisdom of the enneagram: the complete guide to psychological j bagh college dentistry vol. 31(4), december 2019 personality types 18 and spiritual growth for the nine personality types. new york: bantam books; 1999. p. 153-155. 25. stelmack sr. on the psychobiology of personality: essays in honor of marvin zuckerman. elsevier; 2004. p.353. 26. zuckerman, m. psychobiology of personality. 2nd, revised and updated. new york: cambridge university press, 2005 الخالصة باحدى مقاييس , ادراكهم و تصرفاتهم. يمكن االستعانة عامة بانها مجموعة من الخصائص التي تصف االفراد من حيث مشاعرهم: تعرف الشخصية بصورة المقدمة على انماط الشخصية تاثيرالتعرف على صحة الفم. تهدف هذه الدراسة بعالقتها على الشخصية للتعرف على شخصية الفرد او نمطه ،والتي سوف تساعدنا في التعرف .لدى مدرسات المرحلة الثانوية في مدينة بغداد (testosteroneوعالقته باحدى هرمونات اللعاب ) تسوس االسنان هيودسن لألنماط -من مدرسات المرحلة الثانوية في مدينة بغداد ، اللواتي اجبن على مقياس ريسو 534تضمنت الدراسة مشاركة عينة مكونة من : المواد وطرق العمل و تم اختيار مجموعة من المدرسات عشوائيا الخذ dmfs تسوس االسنان باستخدام مؤشر التسوس اإلنيكرام. تم اجراء الفحص للعينة ذاتها لتقويم -التسعة للشخصية (. testosterone) اللعاب ز احدى هرموناتعينة اللعاب وقياس تركي توسط الدرجاتاظهرت الدراسة ان النسبة المؤية االكبر للمدرسات كان لديهم نمط الشخصة السائد هو النمط المساعد. واظهرت النتائج وجود فرق معنوي بمالنتائج: في اللعاب والدرجات (testosterone) رتباط معنوي بين تركيز الهرمون الذكري المحسوبة لتسوس االسنان بين االنماط التسعة للشخصية. لم تظهر الدراسة اي ا . (dmfs) تسوس االسنان ومؤشرات مقياس اللعاب في الهرمون تركيز بين معنوي ارتباط اي الدراسة ايضا تظهر المحسوبة لالنماط التسعة. لم لتحسين االسنان قد يساعد على تفسير االختالف في نسبة انتشار التسوس بين االفراد و تقويم قدرة االفرادالتعرف على انماط الشخصية وعالقته بتسوس االستنتاج: صحة الفم واالسنان j bagh college dentistry vol. 29(3), september 2017 assessing the radiopacity restorative dentistry 26 assessing the radiopacity of three resin composite materials using a digital radiography technique noor salman nadhum, b.d.s., m.sc. (1) rasha hameid jehad, b.d.s., m.sc. (2) shatha abdul-kareem, b.d.s., m.sc. (2) raghad a.al-hashimi, b.d.s., m.sc., ph.d.(3,4) abstract background: radiopacity is one of the prerequisites for dental materials, especially for composite restorations. it's essential for easy detection of secondary dental caries as well as observation of the radiographic interface between the materials and tooth structure. the aim of this study to assess the difference in radiopacity of different resin composites using a digital x-ray system. materials and methods: ten specimens (6mm diameter and 1mm thickness) of three types of composite resins (evetric, estelite sigma quick,and g-aenial) were fabricated using teflon mold. the radiopacity was assessed using dental radiography equipment in combination with a phosphor plate digital system and a grey scale value aluminum step wedge with thickness varying from 1mm to 10mm in steps of 1mm each. the tested materials were radiographed, we used image j software, on a computer screen to evaluate the degree of radiopacity for each individual material and compare with the aluminum step wedge. radiopacity was expressed in mm of equivalent aluminum step wedge. analysis of varience (anova) and least significant difference (lsd) were used to investigate the significance of differences among the tested groups. results: statistical analysis showed highly significant difference among the tested groups (p≤0.01). amongst, g-aenial composite shows the most radiopaque and it is above or equivalent to that of enamel, while estelite sigma quick composite has the lowest radiopacity value and is equivalent to that of dentin. conclusion: in line with previous studies, and within the limitation of our study, considerable variations in radiopacity values were found among materials depending on the radiopaque elements incorporated into the matrix. all composite materials tested complied with the iso 4049 standard. keywords: aluminum, digital imaging, radiopacity. (j bagh coll dentistry 2017; 29(3):26-30) introduction materials like restorative composites are not inherently radiopaque and without modification of their composition, would not be visible on an x-ray film except as a dark spot when deposited into the tooth structure. on the other hand the decay in tooth structure shows up as a dark area on an x-ray film. in the early days of composite technology, it was a challenge to distinguish radiographically between a composite filling and an area of decay in a tooth.1 the addition radiopacifiers, zirconium dioxide, barium oxide or ytterbium oxide to any radiolucent material will impart the property of radiopacity. this become one of the requirement of any restorative materials to allow the clinician to evaluate restoration integrity at subsequent recall appointments, distinguish caries from restorative material on radiographs, and detect voids, overhangs and open margins.2 (1) assistant lecturer, department of conservative dentistry, college of dentistry, university of baghdad, iraq (2) lecturer, department of conservative dentistry, college of dentistry, university of baghdad, iraq (3) assistant professor, department of conservative dentistry ,college of dentistry, university of baghdad, iraq (4) department of conservative dentistry, king's college london dental institute, london, uk a restorative material with radiopacity slightly greater than or equal to enamel considered ideal for detection of secondary caries.3 a number of studies have evaluated the radiopacity of dental composites.4,5,6 abou-tabl et al., 7 used an aluminum step wedge as a radiographic reference for evaluating the radiopacity of dental materials. according to the iso 4049 guidelines, the dental materials radiopacity should be equal to or greater than the same thickness of aluminum and should not be less than 0.5 mm of any value claimed by the manufacturer.8 radiopacity used to be measured by transmission densitometry, direct and indirect digital radiography. since 1989 a digital system considered satisfactory for dentistry and dental research.9 there are several types of sensor: chargecoupled devices (ccd), complementary metal oxide semiconductor (cmos) and photostimulabe phosphor plates (imaging plate). the most important advantage of digital clinic radiographic system is the greater sensitivity of the detector in comparison with that of silver halide film that results in decrease the hazard of j bagh college dentistry vol. 29(3), september 2017 assessing the radiopacity restorative dentistry 27 radiation exposure (radiation dose). this technique includes digitalization of radiographic images and the use of specific software to discriminate different greyscale value.10 materials and methods: in this in vitro, experimental research, we used three resin composites commercially available, evetric (ivoclar vivadent), estelite sigma quick (tokuyama dental america inc.), and g-aenial (gc europe). we made ten disk specimens for each material. to do that,teflon mold 6mm in diameter and 1 mm in thickness as suggested by iso standard 4049,were used.8 the specimens were prepared and manipulated according to the manufacturer's instructions for each material. teflon mold placed between two glass slides. after loading the material, the mold clamped under 150 gm pressure to expel excess material ,reduce voids, and to ensure equal pressure and flat surface to all samples, 11 then light cured using (qd, uk) unit with a power of 450 mw/cm2 for 40 seconds on each side. after removing the specimens from the mold, we polish them using medium, fine, and super fine sandpaper disks (soflex, 3m espe,st. paul, mn, usa) on a slow handpiece in accordance with the manufacturer's instructions.12 after polishing, the samples were cleaned with distilled water. the uniformity of the thickness was precisely calculated by a digital caliper (maplin electronics, rotherham, uk). the specimens were stored in distilled water 37ºc for a day in order to complete polymerization of the material.13 a 99.5% pure aluminum step wedge with ten 1-mm incremental steps was used as an internal radiographic standard and as a gauge to calculate the radiopacity of each material in terms of al thickness.14 the specimens were then radiographed using a periapical film supplied with storage phosphor plate (digora, soredex, helsinki, finland) together with al step wedge using radiography unit. the exposure parameters were set up at 70 kv, 8 ma, and 0.2s. the object to focus distance was 30 cm. storage phosphor plates were then scanned using digora scanner and digital images were obtained and converted to the computer using digora for windows software. the optical densities of the tested materials were analyzed on computer screen using specific image j software (image j processing and analysis in java,version 1.47g) and the grey-scale values (density measurements) converted into mm equivalents of aluminum and recorded.15 table 1: filler compositions taken from the manufacturers' instruction and data sheet composite filler composition % weight g-aenial prepolymerised filler with silicon 77% evetric barium glass , ytterbium trifluoride ,mixed oxide and copolymers 80-81% estelite sigma quick silica-zirconia filler and composite filler 82% figure 1: radiograph showing the radiopacity values of evetric composite in relation to the density of aluminum step wedge figure 2: radiograph showing the radiopacity values of estelite sigma quick composite in relation to the density of aluminum step wedge significant difference between a and c (evetric and g-aenial) table 4 j bagh college dentistry vol. 29(3), september 2017 assessing the radiopacity restorative dentistry 28 a b c g-aenial figure 3: radiograph showing the radiopacity values of g-aenial composite in relation to the density of aluminum step wedge results: after calculating the parametric values table 2, we found that g-aenial composite resin (group c) showed the highest mean of radiopacity value followed by evetric composite (group a) and estelite sigma quick (group b) composite materials. analysis of variance ''anova'' revealed that there was a highly significant statistical difference among the tested groups, a evetric, b estelite sigma quick, and c g-aenial composite materials (p≤0.01) table 3. further investigations using least significant difference (lsd) showed that there was a highly significant difference in radiopacity between a and b (evetric and estelite sigma quick) also between the latter and c (g-aenial) and a highly table 2: descriptive statistics of radiopacity values in mm for all groups. group a evetric composite resin, group b estelite sigma quick composite resin,and group c g-aenial composite resin tested groups mean (mm) std. deviation minimum value (mm) maximum value (mm) group a 1.93 0.1473 1.70 2.20 group b 0.79 0.0626 0.70 0.88 group c 2.80 0.1617 2.43 2.93 table 3: anova test comparison among groups. group a evetric composite resin, group b estelite sigma quick composite resin,and group c g-aenial composite resin compare d groups mea n std. deviatio n f significanc e group a 1.93 0.1473 587.2 4 hs* group b 0.79 0.0626 group c 2.80 0.1617 * donates highly significant difference of p ≤0.01 table 4: group by group comparison using least significant difference test for radiopacity among groups. group a evetric composite resin, group b estelite sigma quick composite resin,and group c g-aenial composite resin compared groups mean difference significance a vs.b 1.139 hs* a vs.c 0.869 hs* b vs.c 2.008 hs* * donates highly significant difference of p ≤0.01 figure 4: showing mean of radiopacity values in mm for all groups discussion nowadays radiopacity becomes essential to evaluate any type of restorative material in terms of quality and the long term success of restorations.5 iso standard 4049 states that resin composite radiopacity should exceed that of estelite sigma quick j bagh college dentistry vol. 29(3), september 2017 assessing the radiopacity restorative dentistry 29 dentin and equal or exceed the same thickness of aluminum. it has been recommended that the radiopacity of resin composites should be equal to or greater than that of the enamel. 3, 10,16,17,18 however, the higher radiopacity of amalgam restorations may lead to under and over scoring secondary caries and marginal defects compared to composite restorations. caries lesions and marginal defects may be over diagnosed with high radiopaque restorations, so moderate radiopacity might be more favorable and will make caries detection easier. distinguishing the restoration from tooth structures radiographically was reported to be more visible in areas primarily composed of dentin because of the lower dentinal radiopacity compared to composite materials.19 the methodology used to measure radiopacity value in the present study is based on measurement of the pixel grey scale (image j) value using specific software after digitalization of conventional film. the digital radiographic system has been used effectively in recent studies for radiopacity measurements of composite materials.9, 11, 20 each composite material was radiographed along with aluminum step wedge that was used for reference. for every radiograph the average greyscale value of the material was converted into absorbance and compared with that of the reference step wedge using image j software in order to determine the equivalent radiopacity in terms of millimeters of al per millimeter of material. the material's radiopacity values are related to the relative atomic mass of constituent elements. polymeric dental materials can be made radiopaque by incorporation of radiopaque elements into either the filler particles or monomer liquids. the radiopacity of resin composites depends on the percentage and type of fillers. 10, 12, 21 introduction of chemical elements with high atomic numbers such as zinc, strontium, zirconium, barium, yetterbium and lanthanum result in more radiopaque materials. they are usually added to inorganic fillers before preparation of splintered filler particles. 3, 12 the more radiopaque the elements are, the more radiopaque the material will be. according to our results, the radiopacity value of estelite sigma quick (supra nanofilled) is the lowest one, this may be related to the insufficient amount of radiopaque elements incorporated into the matrix. it contains silica-zirconia filler only which is spherical submicron one (0.2 μm). silica (silicon dioxide filler) has low atomic number, this make the material has low radiopacity but it is comparable to that of dentin and equal to that of the same thickness of al. also it may be related to the presence of bisgma in the resin matrix, this content make the composite material appear more radiolucent than udma and tegdma based composite. 22 evetric composite material show a radiopacity in between to that of enamel and dentin and higher than that of estelite sigma quick and lower than that of estelite sigma quick and lower than that of g-aenial composite. its high radiopacity may be related to the presence of barium glass (ba atomic number 56) and ytterbium (yb atomic number 70), these elements incorporated into composite materials to increase radiopacity. it is a nanohybrid composite with 40-30000 nm filler particle size and dimethacrylate resin matrix. g-aenial composite material showed the highest radiopacity among the tested material, however, it is comparable to that of enamel. this composite material is nanohybrid with prepolymerised filler (ppf) with silicon. the ppf containing 400 nm strontium glass (st atomic number 38) and 100 nm lanthanoid fluoride (la atomic number 57) with 16 nm fumed silica. it is a bis-gma free composite, it contains a mixture of udma and dimethacrylate comonomers. adequate radiopacity of restorative materials assists in the radiological diagnosis of caries and the overall condition of existing restorations. adequate radiopacity must, therefore, be accepted as one of the major factors when evaluating the clinical success of restorations. conclusion the contemporary restorative resin composites assessed in this study presented different radiopacity values. the radiopacity of resin composites is dependent on the material type. the use of materials with radiopacity close to or less than dentin may result in further diagnostic challenges. however, all the tested materials complied with the requirement of iso 4049 guidelines. references 1 goshima tand goshima y . the optimum level of radiopacity in posterior composite resins. dentomaxillofac.radiol 1989; 18: 19-21. 2 espelid i, tveit ab, erickson ri., keck sc, glasspoole ea. radiopacity of restorations and detection of secondary caries. dent mater 1991; 7: 114-7. 3 turgut md, attar n, oren a. radiopacity of direct esthetic restorative material. oper dent 2003; 28: 508-514. 4 toyooka h, taira m, wakasa k, yamaki m, fujita m, wada t. radiopacity of 12 visible –light cured j bagh college dentistry vol. 29(3), september 2017 assessing the radiopacity restorative dentistry 30 dental composites resins.j oral rehabil 1993; 20: 615-22. 5 bouschlicher mr, cobb ds, boyer db. radiopacity of compomers, flowable and conventional resin composite for posterior restorations. oper dent 1999; 24:20-5. 6 aoyagi y , takahashi h, iwasaki n, honda e, kurabayashi t. radiopacity of experimental composite resins containing radiopaque materials. dent mater j 2005; 24:315-20. 7 abou-tabl zm, tidy dc, combe ec. radiopacity of composite restorative materials. brit dent j 1979; 147:187-8. 8 international organization for standardization. dentistry polymer–based filling, restorative and luting materials. iso 4049 2000(e). 9 nomoto r, mishima a, kobayashi k, et al. quantitative determination of radiopacity: equivalence of digital and film x-ray systems. dent mater 2008; 24: 141-147. 10 sabbagh j, vreven j, lelap g. radiopacity of resinbased materials measured in film radiographs and storage phosphor plate (digora). oper dent 2004; 29: 677-684. 11 dukic w, delija b, derossi d, and dadic i.radiopacity of composite dental materials using a digital x-ray system. dent mater 2012; 31(1):47-53. 12 attar n, tam le, mc comb d. flow, strength, stiffness and radiopacity of flowable resin composites. j canad dent assoc 2003; 69: 516-21. 13 ergucu z, turkun ls, onem e, guneri p. comparative 47of six flowable resin composites. oper dent 2010, 35(4): 436-440. 14 american dental association council on dental materials, instruments and equipments. the desirability of using radiopaque plastics in dentistry: a status report (1981) journal of the american dental association 102 (3) 347-349. 15 alhashimi ra. assessing the radiopacity of new root end filling materials using digital radiography technique. mdj 2015; 12: 10-15 16 murchison df, charlton dg, moore ws. comparative radiopacity of flowable resin composites. quintessence int 1999; 30:179-184. 17 el-mowafy om, benmergui c. radiopacity of resin-based inlay luting cements. oper dent 1994; 19:11-15. 18 van dijken jw, wing kr, ruyter ie. an evaluation of the radiopacity of composite restorative materials used in class i and class ii cavities. acta odontol scand 1989; 47:401-407. 19 treit ab, espelid i. radiographic diagnosis of caries and marginal defects in connection with radiopaque composite fillings. dent mater 1989; 2:159-162. 20 salzedas lm, louzada mj, de olivira filho ab. radiopacity of restorative materials using digital images. j appl oral sci 2006; 14:147-152. 21 nakamara t, tanaka h, kawamura y and wakabayshi k. translucency of glass-fiber reinforced composite materials j oral rehabil 2004 3:817-821. 22 azzopardi n, moharamzadeh k, wood dj, martin n, van noort r. effect of resin matrix composition on the translucency of experimental dental composite resins. dent mater 2009; 25:1564-1568. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 3 (2022), issn (p): 1817-1869, issn (e): 2311-5270 1 research article serum ferritin level and b12 in a sample of iraqi recurrent aphthous stomatitis patients noor s. mohammed ali 1* 1 assistant lecturer, department of oral diagnosis, college of dentistry, university of baghdad. * correspondence: noorsaad2011@codental.uobaghdad.edu.iq abstract: background: with a frequency of 50–66%, recurrent aphthous stomatitis (ras) is one of the most prevalent conditions affecting the oral mucosa. it is unknown how common hematinic deficiencies, such as those in vitamin b12 and ferritin, affect the prevention and progression of ras. numerous investigations have shown that individuals with ras have a significant frequency of hematinic deficits. this research compared patients with recurrent aphthous ulcers and healthy controls' serum levels of ferritin and vitamin b12.subjects, materials and methods: patients who need blood testing to rule out anemia between november 2020 and may 2021 provided the data. the institutional ethics committee gave its approval to the project. 5ml of blood was taken from patients and controls in educational labs after they had provided their demographic information (age, gender, occupation, and residance). the serum was then centrifuged at 3000 rpm for 10 minutes before being stored at -20°c until serum ferritin and vitamin b12 levels were determined. the information was presented as mean ± sd. when comparing biochemical parameters between patients and controls using students unpaired t-test.a p-value of< 0.05 was deemed statistically significant, while a p-value of< 0.001 was deemed highly statistically significant, results: a total of 30 ras patients and 30 healthy control with age and gender matches were included. 40% of the patients had low serum ferritin levels and 56.6% of the patients had low serum vitamin b12 levels, according to statistical analysis of the current study. significant differences were also seen between the two groups' serum levels of ferritin and vitamin b12.conclusion: patients with recurrent aphthous stomatitis require serum ferritin and vitamin b12 measurements. in order to stop the recurrence of aphthous ulceration, it's crucial for people with recurrent aphthous ulcers to consume a balanced diet rich in iron and vitamin b12. keywords: ferritin, serum b12, recurrent aphthous ulceration. introduction one of the most prevalent conditions affecting the oral mucosa, recurrent aphthous stomatitis (ras) is defined as the occurrence of reoccurring ulcerations exclusive to the oral mucosa. it affects 20% of the general population and up to 60% of some areas of populations (1). according to its clinical characteristics, ras is typically divided into three clinical forms: minor, major, and herpetiform ulcers. more than 80% of patients with the minor form of ras are vulnerable to recurrences, with estimates for three-month recurrence rates as high as 50%(2). they typically appear as little round or oval ulcers with erythromatous "halos" and a yellow-grey tint. they typically heal without leaving any permanent scars (3). despite numerous circumstances, the precise cause of aphthous ulcers is still unknown . although numerous factors, including smoking, immunological issues, stress, hematological problems, hormone imbalances, infections, vitamin deficiencies, and hereditary factors, have been linked to the pathogenesis of ras, the actual cause of aphthous ulcers is still unknown (3,4). it has been suggested that hematinic deficiencies, such as a deficiency in ferritin, folate, or vitamin b12, may be the cause of ras. it is unknown how common hematinic deficiencies, such as those in ferritin and vitamin b12, are or what role they play in the prevention and progression of ras(5). while some research have found no connection between ras and a deficit in iron, folate, or vitamin b12 (5, 6), other investigations have shown a significant incidence of hematinic deficits in ras patients (7-9). received date: 13-12-2021 accepted date: 14-1-2022 published date: 15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license. (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v34i3.3211 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3211 https://doi.org/10.26477/jbcd.v34i3.3211 j. bagh. coll. dent. vol. 34, no. 3 2022 ali 2 a globular intracellular protein called ferritin accumulates iron and releases it gradually over time. although ferritin is mostly present in the cytosol of most tissues, it is also released in minute amounts into the serum, where it serves as an iron carrier. serum ferritin is utilized as a diagnostic test for iron-deficiency anemia because plasma ferritin is also an indirect indicator of the total amount of iron stored in the body (10). since the discovery and identification of vitamin b12 more than 60 years ago and the realization of its essential role in the serious condition known as pernicious anemia, much has been learned about b12 deficiency. vitamin b12, also known as cobalamin, is one of the eight b vitamins (11). ras's pathogenesis is unclear, hence diagnosis is solely reliant on history and clinical criteria since there are no available laboratory tests to back up the finding (12). because there have been few studies on the association between ras and serum ferritin and vitamin b12 levels, the current study seeks to assess ferritin and vitamin b12 levels in patients with recurrent aphthous ulcers and healthy controls. subjects , materials and methods the data was collected from patients who needed blood analysis to exclude anemia from november 2020 till may 2021. the study was approved by the institutional ethics committee. an oral medicine specialist established the diagnosis based on the existence of round, symmetrical, yellow-white ulcers with a diameter of less than 1 cm and also an erythematous halo surrounded by a detachable membrane that healed completely without leaving any scars. there were exclusion criteria including chronic smokers and alcoholism, patients with a history of medical diseases such as behcet's disease, hypertension, cardiac diseases, hepatic, renal, hematological disorders, crohn's disease and ulcerative colitis, subjects on medications such as cytotoxic agents such as methotrexate, non-steroidal anti-inflammatory drugs, sulphonamides, rifampicin and vancomycin (3). the subjects in the control group without a history of illness and without any ras lesions at the time of data collection; these were collected from previously documented data. demographic information on patients, including their residence, gender, age, and occupation, from patients and controls, 5ml of venous blood was collected in the educational laboratories, serum was centrifuged at 3000 rpm for 10 minutes, and it was kept at -20°c until the evaluation. serum ferritin levels were estimated using elisa kits from biocheck usa and vitamin b12 was estimated using ibl kits from the usa. spss software, version18.0 (chicago, illinois, usa) was used for the statistical analysis. the data was presented as mean± sd. when comparing biochemical parameters between patients and controls using the unpaired t-test, a p-value of < 0.05 was regarded as statistically significant while a p-value of <0.001 was considered a highly statistically significant. results a total of 30 ras patients and 30 healthy control were included in the final analysis. table 1 displays the demographic information of the subjects. table 1: demographic information of the ras patients and controls. ras patients healthy control number of subjects 30 30 age (mean± sd) 31.86 ± 5.88 32.4 ± 5.96 male : female 14 : 16 13 : 17 j. bagh. coll. dent. vol. 34, no. 3 2022 ali 3 low ferritin levels were seen in 12 ras patients and 5 controls (p>0.05), while the mean estimates of normal levels of serum ferritin between patients and control were highly significant difference p<0.001. 17 ras patients and 6 controls had serum vitamin b12 levels that were ≤ 220pg/ml. (p<0.05), it was demonstrated that there was a highly significant difference in the mean estimations of serum b12 and ferritin between ras patients and healthy controls (p<0.001) as shown in table 2. table2: a comparison of serum ferritin levels and vitamin b12 levels in ras patients and controls. variable ras patients healthy control number mean ± sd number mean ± sd serum ferritin ( ng/ml) low 12 9.86 ± 4.34 5 8.98 ± 0.93 normal 18 59.44 ± 26.63 25 91.8 ± 34.16** total 30 39.62 ± 32.14 30 77.99 ± 44.17** serum b12 ( pg/ml) low 17 178.58 ± 30.53 6 208.66 ± 11.57* normal 13 396.15 ± 154.31 24 691.5 ± 138.7** total 30 272.86 ± 149.6 30 580.33 ± 230.7** cut-off values for low levels b 12 ≤ 220 pg/ml ferritin male ≤ 10ng/ml female ≤ 20 ng/ml *=p<0.05 **=p<0.001 discussion in the current study, the serum level of ferritin and vitamin b12 were compared between ras patients and healthy controls.. the demographic characteristics of the patients and controls showed no statistically significant difference. the most common ras patients affected were females and between 3241 years of age. the age and gender incidence are similar to other studies. the fact that women have a significant propensity to become anemic may help to explain the increased incidence of ras in females as indicated by previous research (13). several investigations have shown no link between ras and iron, folate, or vitamin b12 deficiency (5, 6). while other research has j. bagh. coll. dent. vol. 34, no. 3 2022 ali 4 shown that ras patients have a significant frequency of hematinic deficits (7-9) . in the present research, statistically significant variations in ferritin and vitamin b12 serum levels were found between the two groups. 40% of the patients in the current research showed low serum ferritin levels., other studies have reported similar but with varying percentages of serum ferritin levels. some have reported 60% of patients having low serum ferritin levels, while others have reported as low as 20% (3, 14, 15, 16) . serum b12 is required for dna synthesis, and its insufficiency causes megaloblastic anemia, particularly in impoverished nations. vitamin b12 deficiency inhibits cell-mediated immunity and causes abnormalities in the tongue epithelium and buccal mucosa (3, 17). serum vitamin b12 levels were low in 56.6% of the patients in this investigation. other studies have also reported similar findings but with varying percentages of vitamin b12 deficiency (15, 18, 19, 20) . vitamin b12 insufficiency interferes with the metabolism of folate, which can cause folate deficiency (21, 22). therefore, in addition to vitamin b12 measurement, serum folate level should also be measured in cases of ras.this study also tried to classify the patients and controls into subjects with normal values or low values by specified cut-off values of kits used. many studies had used their cutoff values in accordance with the local laboratory outcomes. however, most studies only relied on the proportions having low or high positions in the patients and control as whole groups (23, 24). 70% of patients with recurrent aphthous ulcers improved with hematinic replacement therapy(25). future research should ideally have a large sample size and measure the levels of serum folate to investigate the association between ras and serum folate. conclusion in the current study, low serum ferritin levels were found in 40% of patients, while low serum vitamin b12 levels were observed in 56.6% of patients.. serum ferritin and vitamin b12 levels must be measured in individuals with recurring aphthous stomatitis. recurrent aphthous ulcer sufferers must also follow a healthy diet rich in iron and vitamin b12 to avoid aphthous ulcer recurrence. conflict of interest: none. references 1. ujević a, lugović-mihić l, situm m, ljubesić l, mihić j, troskot n. aphthous ulcers as a multifactorial problem. acta clin croat. 2013;52:213-21. 2. tarakji b, gazal g, al-maweri sa, azzeghaiby sn, alaizari n. guideline for the diagnosis and treatment of recurrent aphthous stomatitis for dental practitioners. j int oral health. 2015;7:74-80. 3. moin sabeer tidgundi , khaja moinuddin, , mirza sharif ahmed baig. ferritin and vitamin b12 levels in patients with recurrent aphthous ulcers. international journal of clinical biochemistry and research, april-june 2017;4(2):136-139. 4. fischman sl. oral ulcerations. semin dermatol 1994;13(2):74-7. 5. koybasi s, parlak ah, serin e, et al. recurrent aphthous stomatitis: investigation of possible etiologic factors. am j otolaryngol 2006;27(4):229-32. 6. carrozzo m, bone mc, gandolfo s. recurrent aphthous stomatitis: current etiopathogenetic and therapeutic concepts. minerva stomatol 1995;44(10):467-75. 7. challacombe sj, scully c, keevil b et al. serum ferritin in recurrent oral ulceration. j oral pathol. 1983;12(4):290-9. j. bagh. coll. dent. vol. 34, no. 3 2022 ali 5 8. porter sr, scully c, flint sr, et al. haematological status in recurrent aphthous stomatitis compared with other oral disease. oral surg oral med oral pathol 1988;66(1):41-4. 9. field ea, rotter e, speechley ja, tyldesley wr. clinical and haematological assessment of children with recurrent aphthous ulceration. br dent j 1987;163(11):19-22. 10. wang w, knovich ma, coffman lg, torti fm, torti sv ."serum ferritin: past, present and future" biochimica et biophysica acta (bba) 2010 aug;1800 (8): 760–9. 11. green, r. & miller, j. w. in handbook of vitamins 5th edn (eds zempleni, j. et al.) 447–489 (taylor & francis, 2014). a comprehensive review of b12 biochemistry, nutrition and metabolism. 12. natah ss, konttinen yt, enattah ns, ashammakhi n, sharkey ka, hayrinen-immonen r. recurrent aphthous ulcers today: a review of the growing knowledge. int j oral maxillofac implants 2004;33(3):221-34. 13. sumathi k, shanthi b, subha palaneeswari m, manjula devi a.j. significance of ferritin in recurrent oral ulceration. j clin d iagn res 2014;8(3):14-15. 14. nabiha farasat khan, mohammad saeed, saima chaudhary, et al. haematological parameters and recurrent aphthous stomatitis. journal of the college of physicians and surgeons pakistan 2013;23(2):124-7. 15. farkhanda ghafoor , ayyaz a kha. association of vitamin b12, serum ferritin and folate levels with recurrent oral ulceration. pak j med res 2012; 51 (4):132-135. 16. rogers rs, hutton kp. screening for haematinic deficiencies in patients with recurrent aphthous stomatitis. aust i derm 1986;27(3):98-103. 17. volkov i, press y, rudoy i. vitamin b12 could be a “master key” in the regulation of multiple pathological processes. j nippon med sch 2006;73(2):65-9. 18. thongprasom k, youngnak p, aneksuk v. hematologic abnormalities in recurrent oral ulceration. south asian j trop med public health 2002; 33: 872-7. 19. wary d, ferguson mm, hutcheon wa, dagg jh. nutritional deficiencies in recurrent aphthae. j oral pathol 1978;7:418-23. 20. olson ja, feinberg i, silverman s jr, abrams d, greenspan js. oral surg oral med oral pathol 1982; 54: 571-20. 21. nolan a, lamey pj, milligan ka, forsyth a. recurrent aphthous ulceration and food sensitivity. j oral pathol med 1991;20(10):473-5. 22. weusten bl, van de wiel a. aphthous ulcers and vit b12 deficiency. neth j med 1998;53:172-5. 23. burgan sz, sawair fa, amarin zo. hematologic status in patients with recurrent aphthous stomatitis in jordan. saudi med j. 2006; 27: 381-4. 24. piskin s, sayan c, durukan n, senol m. serum iron, ferritin, folic acid, and vitamin b12 levels in recurrent aphthous stomatitis. j eur acad dermatol venereol. 2002; 16:66-7. j. bagh. coll. dent. vol. 34, no. 3 2022 ali 6 25. volkov iiia, rudoy i, freud t, sardal g, naimer s, peleg r, et al. effectiveness of vitamin b12 in treating recurrent aphthou s stamatitis: a randomized, double blind placebo controlled trial. j am board fam med 2009; 22: 9-1. في عينة من المرضى العراقيين المصابين بالتهاب الفم القالعي المتكرر 12ين في الدم و فيتامين ب مستوى الفيريت نور سعد محمد علي : المستخلص ٪. إن انتشار نقص الدم بما في ذلك 66-50( هو أحد أكثر اضطرابات الغشاء المخاطي للفم شيوعًا بمعدل انتشار يقارب rasالخلفية :التهاب الفم القالعي المتكرر ) . كان rasغير معروف جيدًا. أظهرت العديد من الدراسات انتشاًرا كبيًرا لنقص الدم في مرضى rasودورها في الوقاية وتطوير b12نقص الفيريتين وفيتامين في المرضى الذين يعانون من القرحة القالعية المتكررة والضوابط الصحية. 12الدراسة هو مقارنة مستويات مصل الفيريتين وفيتامين ب الهدف من الموافقة على . تمت 2021إلى مايو 2020االشخاص والمواد والطريقة: تم جمع البيانات من المرضى الذين يحتاجون إلى تحليل الدم الستبعاد فقر الدم من نوفمبر للمرضى السكانية التركيبة تسجيل بعد المؤسسية. األخالقيات لجنة قبل من والعنوان (الدراسة والمهنة والجنس سحب )العمر تم المرضى 5، من الدم من مل درجة مئوية لتقييم مصل الفيريتين وفيتامين 20-عند تم تخزين المصل ثم دقائق ، 10دورة في الدقيقة لمدة 3000والضوابط في المعامل التعليمية التي تم طردها عند مات البيوكيميائية بين المرضى وعناصر التحكم ، واعتبرت و. يستخدم اختبار الطالب غير المقيدين لمقارنة المعل mean ± sd. تم التعبير عن البيانات على أنها 12ب ذات داللة إحصائية عالية. p <0,001بينما اعتبرت قيمة ذات داللة إحصائية p <0,05قيمة من الضوابط الصحية العمرية والجنس ، في الدراسة الحالية لوحظت فروق ذات داللة إحصائية في 30و rasمريًضا من 30لنتائج: تم تضمين ما مجموعه ا ٪ من المرضى لديهم مستويات 56,6مستويات الفيريتين و ٪ من المرضى لديهم مصل منخفض 40بين المجموعتين ، b12مستويات المصل من الفيريتين وفيتامين في الدم. 12منخفضة من فيتامين ب في الدم ضروري لمرضى التهاب الفم القالعي المتكرر. من المهم أيًضا لمرضى القرحة القالعية المتكررة اتباع 12الخالصة: قياس مستويات الفيريتين وفيتامين ب لمنع تكرار التقرح القالعي. 12د وفيتامين ب نظام غذائي يحتوي على الحدي j bagh college dentistry vol. 29(2), june 2017 antimicrobial effect oral and maxillofacial surgery and periodontics 78 anti-microbial effect of different time’sexposureofozonized gas and ozonized water onperiodontalpathogens (in vitro study) ban zuhair ahmmad, b.d.s.(1) leqaa mahmood ibraheem. b.d.s., m.sc.(2) abstract background: the oral cavity is consider to be an open ecosystem, with the balance between the microorganism’s entrance and the defenses of the host. the initiation of periodontitis has been associated with restricted kinds of anaerobic bacteria, such as aggregatibacter actinomycetemcomitans (a.a) and porphyromonas gingivalis (p.g) in plaque subgingivally. ozone has a biological effects on bacteria due to oxidation of bio-molecules and its toxins. the aim is to determine and compare the antimicrobial effect of gaseous ozone and ozonized water on the growth of isolated anaerobic bacteria (a.a and p.g) when exposed to different time intervals. materials and methods:this experiment is done byozone generator olympiciii(600mg/hr) to generator the gaseous ozone (218ppm/w-air)which bypassed around the agar plates containing on of the isolated bacteria with different time intervals (1-10 minutes).and with special aeration stone for generation of ozonized water (0.6 ppm) with different time intervals (1-15 minutes). results: gaseousozone have a significant reduction in the bacterial growth on the agar plates for (a.a) was 7 minutes and (p.g) was 4 minutes. while ozonated water have also a significant reduction in the bacterial growth on the agar plates for (a.a) was 5 minutes and (p.g) was 4 minutes. conclusion: bothgaseousozone and ozonized water are a powerful antimicrobialeffects on anaerobic microorganism isolated from chronic periodontitis patients. keywords: gaseousozone, ozonized water, aggregatibacter actinomycetemcomitans (a.a) , porphyromonas gingivalis (p.g) (j bagh coll dentistry 2017; 29(2): 82-78 ) introduction periodontitis is a destructive and inflammatory disease of the connective tissues that supportingthe teeth and is caused either by one specific type of microorganism or by a group of specific microorganisms, leading to progressive destruction of periodontal ligament and alveolar bone with the formation of periodontal pocket, gingival recession, or both (1). bacteria are the prime etiological agents in periodontal disease, and it is estimated that more than 500 different bacterial species are capable of colonizing the adult mouth (2). aggregatibacter actinomycetemcomitans is considered a primary pathogen in localized and generalized chronic periodontitis (3). while, prohormones gingivalis is implicated in chronic and aggressive periodontitis (4). it is considered one of the main etiologic agents of destructive periodontal disease (5,6). ozone is a potent oxidant and an important disinfectant, acting on microorganisms by means of oxidation of their biological material (7). it has been reported that ozone can be employed as a bactericidal agent under various forms, such as ozonizedwater (8), ozonized oil, (9), ozone associated with other substances (10), and more frequently the gaseous o3/o2 mixture (11). (1) master student. (2) assistant professor, depart ment of periodontics, college of dentistry, university of baghdad. gaseous ozone has a high oxidation capacity and is greater than chloride for about1.5 times when is use as an antimicrobial agent against several bacteria, viruses, fungi, and protozoa. it has also the ability to stimulate blood circulation and the immune response. such characteristic features can be applied in medicine and dentistry and have been indicated for the treatment of 260 different pathologies(12).ozonized water have a high level of biocompatibility on human oral epithelial cells, gingival fibroblast cells, and periodontal cells(13). ozonized water strongly inhibited the accumulation of dental plaque and is effective in killing grampositive, gramnegative bacteria and oral candida albicans causing periodontal disease materials and methods 1-isolation and identification of the pathogens: the subgingival plaque samples were collected from 10 systemically healthy patients with chronic periodontitis attending the clinic at the department of periodontics in the teaching hospital of the college of dentistry / university of baghdad. the age range was (35-55) years old; the subgingival plaque samples were collected from the periodontal pocket of more j bagh college dentistry vol. 29(2), june 2017 antimicrobial effect oral and maxillofacial surgery and periodontics 79 than˃6 mm depthwith attachment loss of one to two mm.the subgingival plaque was put on a swap that was inserted immediately in transfer media to preserve the sample which is then was spread on selective agar media (tryptic soy agar) for both a.a and p.gand incubated anaerobically using anaerobic jar and anaerobic gas packs in the incubator for 72 hours at 37ºc(15,16). the procedure must be done within a period of less than 30 minutes from collecting the sample from the patient. the identification of both a.a and p.g was done bymorphological characteristic(17), gram’sstain(18) and by using analytical profile index (api) test for the biochemical testes (19) 2. general description of theexperiments: the gaseous ozone was generated form ozone generator olympiciii (600mg/hr).in this experiment a small plastic jar was used. the plastic cover has one ozone gas inlet port to inject the ozone gas and distribute it evenly throughout the jar, and one gas outlet for the release of the ozone gas. the ozone generator was fed with 1 lpm of dry compressed air as a feed gas. ozonized air was bypassed around the agar plates to supply a total air flow of ozone of 218 ppm/w-air. the ozone gas/dry air mixture flowed into the jar for different times (1-10 minutes) according to the experimental design the ozone level inside the plastic jar was kept consistent during the time periods by adjusting the outlet port (fig.1). figure 1: general description of the devise while ozonized water was generated by using special aeration stone, with concentration (0.6 ppm) measured by special chemets-kit.as shown in (fig 2). figure 2: shows the: 1) ozone generator 2) plastic container 3) che mets kit 3. procedure: five well-isolated colonies of the same morphological type which was incubated anaerobically at 37ºc for 24hrs, were selected from tryptic soy agar plate culture. the top of each colony is touched with a loop, and the growth is transferred into a tube containing 5 ml of tryptic soy broth medium. this results in a suspension containing approximately 1 x 108 cfu/ml (equivalent to a 0.5 tube mcfarland standard)(20). using a sterilized loop, a loopful of bacterial growth was streaked on agar petri plate (a.a. /p.g. agar). each plate was exposed to the ozonatedgas for a specific time, and then incubated anaerobically at 37ºc for 24hrs. the bacterial growth corresponding to each exposure time on each plate was performed visually, and recorded (21). while the ozonized water experiment was done with the same suspension by adding 1.0ml of bacterial broth in a test tube and then 1.0ml of ozonized water (0.6ppm) was added to the first tube and mixed well then bystreaking on agar petri plate (a.a. / p.g. agar) for 1,2,3,4,5,10, and 15 minutes respectively. the plates were sealed and incubated in an anaerobic jar at 37ºc overnight .the bacterial growth corresponding to each contact time on each plate was performed visually, and recorded (21). plates showing no bacterial growth means highly efficient exposure time of both ozonized water and the gaseous ozone. results the results for a.a for colony morphology were white radiating star shaped with no black pigmentation with gram negative, coccobacilli and give appositive reaction to api nh test (according to api, a.a is listed as (haemophilus actinomycetemcomitans). while the results for p.g for colony morphology were appeared as 2 1 3 j bagh college dentistry vol. 29(2), june 2017 antimicrobial effect oral and maxillofacial surgery and periodontics 80 round spherical in shape with raised or convex surface, black-pigmented colonies with gram negative, coccobacilli and give appositive reaction to api 20a(according to api, p.g is listed as (p.saccharolytica) with index number (10000004). the results obtained for the qualitative evaluation of ozonated gas (218 ppm/w-air), is presented in table 1. the inactivation effect of ozonated gas was observed on both a. a, and p.g colonies. after ozonated gas exposure, the numbers of bacterial colonies on the agar surface decreased in a time-dependent manner and the colony's growth was no longer detected in 7, and 4 minutes of treatment against a.a and p.g. respectively. the analysis of the results of table 1 verified that the p.g bacteria were much more sensitive toward ozonated gas compared to a.a. table 1: efficiency of ozonated gas at different exposure times ona.a and p.g. colonies growth. exposurtimes(minutes) antimicrobial agent ozonated gas (218 ppm/w-air) a.a p.g 1 +ve +ve 2 +ve +ve 3 +ve +ve 4 +ve -ve 5 +ve -ve 6 +ve -ve 7 -ve -ve 8 -ve -ve 9 -ve -ve 10 -ve -ve +ve =bacterial growth, -ve = no bacterial grow. while the results obtained for the ozonized water is presented in table 2. the inactivation effect of ozonized water was observed on both a. a, and p.g colonies. after ozone exposure, the numbers of bacterial colonies on the agar surface decreased in a time-dependent manner and the colony's growth was no longer detected in 5 and 4 minutes of treatment against a.a and p.g. respectively. table 2: efficiency of ozonated water at different exposure times on a.a and p.g. colonies growth. contact times (minutes) antimicrobial agents ozonated water(0.6 ppm) a.a p.g 1 +ve +ve 2 +ve +ve 3 +ve +ve 4 +ve ve 5 -ve -ve 10 -ve -ve 15 -ve -ve +ve = bacterial growth (uncountable colonies). -ve= no bacterial growth (no colonies). discussions ozone has been proposed in clinical practice of dentistry and medicine due to its several actions such as antimicrobial, anti-inflammatory, immunostimulating, etc. (22). ozone has been used for treatment of early carious lesions, periodontal pockets, wound healing such as ulceration, bleaching and in treatment of periimplantitis(23). the antimicrobialaction of ozone is by damaging the cytoplasmic membrane of the bacteria and cell lysis (24).the results of gaseous ozone experiment was showed that ozonated gas was highly effective in eliminating of both a.a and p.g, (7 and 4 minutes respectively).these results could be explained by the conclusions reached by hauser et al.,in 2011(25)who investigated the use of gaseous ozone on bacteria adhering to implant surfaces and showed a selective reduction in bacteria, concluding that gaseous ozone may have a role in treatment of peri-implantitis. huth et al., in 2011(26) similarly showed significant results with gaseous and aqueous ozone and concluded that they merit further investigation. pereira et al., in 2005(27)reported that application of a gaseous o3/o2 mixture (0.4%/99.6%) for 1 h, at constant pressure and flow (11 mm hg and 2 l/min, respectively) and controlled temperature, in plates containing 104 cfu/ml of e. coli, s. aureus, and p. aeruginosa lead to total inhibition of growth of these bacteria. and fontes et al.,in 2012(28), concluded that the application of a low dose of gaseous ozone (dose of 20 μg of o3/ml in a gaseous o3/o2 mixture) for 5 minutes completely prevented the in vitro growth of gram-positive and negative pathogenic bacteria commonly present in patients with j bagh college dentistry vol. 29(2), june 2017 antimicrobial effect oral and maxillofacial surgery and periodontics 81 severe nosocomial infections, with known resistance to antibiotics. while, the result of ozonized water (0.6 ppm) was highly effective in eliminating of both a.a and p.g (5 and 4 minutes respectively ).this results were in agreement with kshitish and vandana in 2010 (29).it was reported that ozone at low concentration of 0.1 ppm, is sufficient to inactivate bacterial cells including their spores (8).this reacts could explained by the parcens of various chemical compounds in two different and coexisting modes, one involving direct reactions of molecular ozone and the other a free radical-mediated reaction ,both these mechanisms may be involved in the destruction of bacteria by ozone(30).ozonated water had nearly the same antimicrobial activity as 2.5% sodium hypochlorite and also the metabolic activity of fibroblasts was high when the cells were treated with ozonated water. the aqueous form of ozone, as a potential antiseptic agent, showed less cytotoxicity than gaseous ozone or established antimicrobials like chlorhexidine digluconate, sodium hypochlorite or hydrogen peroxide under most conditions. therefore, aqueous ozone fulfils optimal cell biological characteristics in terms of biocompatibility for oral application (31). in conclusions, gaseous ozone and ozonized water form therapy was very efficient against a. actinomycetemcomitans and p. gingivalis, and can be employed as a useful antimicrobial for periodontal 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contemp dent pract 2008; 9:75–84. 13. huth kc, jacob fm.effect of ozone on oral cells compared with established antimicrobials. eur j oral sci2006; 114: 435-440. 14. fukuizumi t, nagayoshi m1, kitamura c, yano j, terashita m, nishihara t.efficacy of ozone on survival and permeability of oral microorganisms.2004; 62(2): 222-233. 15. mythireyi, d., and krishnababa, m.g.2012. aggregatibacter actinomycetemcomitans, an aggressive oral bacteria a review. international journal of health sciences & research 105 vol.2; issue: 5; (www.ijhsr.org). 16. forbes b a, daniel f s, alice s w. bailey and scott’s. 2007. diagnostic microbiology. 12th ed., mosby elsevier company. usa, pp 62-465. 17. haffajee, a. d. and socransky,s. s.1994.“microbial etiological agentsof destructive periodontal diseases,” periodontology 2000, vol. 5,pp. 78–111. 18. isenberg hd. 1992. clinical microbiology procedures handbook. american society for microbiology: asm press. vol.1. 19. bacterial identification using biomerieux api kits, 2013. 20. lalitha, m.k. nccls publication m100-s12 performance standards for antimicrobial testing: twelfth informational supplement 2015; (isbn 156238454 -6). 21. cezar ag, busnello l, alberto i, rottava al, josé, d, oliveira r, luis h, toniazzo. influence of different sanitizers on food contaminant bacteria: effect of exposure temperature, contact time, and product concentration. ciênc. tecnol. aliment., campinas2012; 32(2): 228-233. 22. lynch e, baysan a. reversal of primary root caries using dentrifices containing 5000 and 1100 ppm flouride caries res2001;35:41-46. 23. hickel r, huth c. initial therapeutic impressions of the use of ozone for the treatment of caries. deutscher zahnarzte kalender 2004; 1-10. 24. seidler v,linetskiy l ,hubalkova h. ozone and its usage in general medicine and dentistry .a review article . prague medical report 2008;26, 1049-1059 25. hauser-gerspach i, vadaszan j, deronjic i, gass c, meyer j, et al. influence of gaseous ozone in peri j bagh college dentistry vol. 29(2), june 2017 antimicrobial effect oral and maxillofacial surgery and periodontics 82 implantitis: bactericidal efficacy and cellular response. an in vitro study using titanium and zirconia. clinical oral investigations2011; 16: 10491059. 26. huth kc, quirling m, lenzke s, paschos e, kamereck k, brand k, et al. effectiveness of ozone against periodontal pathogenic microorganisms. eur j oral sci 2011;119:204-10. 27. pereira mms, navarini ia, lýcia mj, pacheco am. jr, silva. r.a. effect of different gases on bacterial growth. experimental study "in vitro". rev col bras cir.2005; 32:1. 28. fontes b, cattani heimbecker am, de souza brito g, costa sf, van der heijden im, levin as, & rasslan s. effect of low-dose gaseous ozone on pathogenic bacteria. bmc infectious diseases2012; 12, 358. 29. kshitish d, laxman vk. the use of ozonated water and 0.2% chlorhexidine in the treatment of periodontitis patients: a clinical and microbiologic study. indian j dent res2010;21:341-348. 30. staehelinj, hoigne j.decomposition of ozone in water in the presence of organic solutes acting as promoters and inhibitors of radical chain reactions.environ sci technol1985. 31. kshitish d, laxman vk. the use of ozonated water and 0.2% chlorhexidine in the treatment of periodontitis patients: a clinical and microbiologic study. indian j dent res 2010;21:341-348. المستخلص الثھ مع انواع المقدمھ: یعتبر التجویف الفمي كنظام بیئي مفتوح مع التوازن بین البكتریا الداخلھ والنظام الدفاعي للجسم. فلھذا یعتبر تطور التھاب في الصفیحھ الجرثومیھ في (البورفوریموناساللثویھ واالجریجاتیباكتر اكتینومایسیتیمكومیتانس)الموجوده محدده من البكتریا الالھوائیھ وخاصھ داخل الجیوب اللثویھ .االوزون لھ تاثیر بایولوجي على البكتربا من خالل اكسده الماده البایولوجیھ والتوكسین للبكتریا. المعزولھ عند تعرضھا الوقات على البكتریا الالھوائیھ و ماء االوزن تاثیر المضاد البكتیري لغاز االوزوندقیقھ) ومقارنھ ھدف الدراسھ : لتحدید مختلفھ دقیقھ) ومع 101) لتولید غاز االوزون بوقت مابین (3المواد والطریقھ: في دراسھ مختبریھ ,اجریت التجربھ من خالل جھاز االوزون (اولمبك بالبكتریا المعزولھ. دقیقھ) والذي سوف یمر على االطباق المزروعھ151استعمال حجر خاص لتولید ماء االوزون بوقت مابین ( النتیجھ: وجد بأن غاز االوزون و ماء االوزون قد قلل بشكل ملحوظ على نمو البكتریا المتواجده باالطبق لكال النوعین. ثھاالستنتاج: غاز االوزون وماء االوزون یعتبر مضاد بكتیري فعال جدا ضد البكتریا االھوائیھ المعزولھ من المرضى المصابین بالتھاب الل المفتاح: غاز االوزون,ماء االوزون, البورفوریموناساللثویھ , االجریجاتیباكتر اكتینومایسیتیمكومیتانس. afrah f.doc j bagh college dentistry vol. 28(2), june 2016 an immunohistochemical oral diagnosis 34 an immunohistochemical expressions of bad, mdm2, and p21 in oral squamous cell carcinoma afrah a. khalil, b.d.s., m.sc. (1) seta a. sarkis, b.d.s., m.sc., ph.d. (2) abstract background: oral squamous cell carcinoma (oscc) is a common malignancy characterized by poor prognosis and low survival rate. the purpose of this study was to evaluate the immunohistochemical expressions of bad, mdm2, and p21as apoptotic markers in oral squamous cell carcinoma. materials and methods: this study was performed on forty formalin-fixed paraffin-embedded blocks which histopathologically diagnosed as oral squamous cell carcinoma. all cases were collected from the histopathological laboratory from patients treated surgically at maxillofacial surgery department at ramadi teaching hospital, iraq. results: the immunohistochemical staining of bad showed positive expression in 39 (97.5%), mdm2 showed positive expression in 39(97.5%) and p21showed positive expression in 34(85%) of the collective cases. conclusion: a statistically significant correlation was found regarding mdm2 with the tumor site, p21 with tumor grade. keywords: squamous cell carcinoma, metastasis, biomarkers, carcinogenesis, apoptosis. (j bagh coll dentistry 2016; 28(2):34-39). introduction oral squamous cell carcinoma (oscc) is a malignant neoplasm of invasive stratified squamous epithelium with varying degrees of squamous differentiation (1). it is capable of locally destructive growth, extensive lymph node invasive and distant metastasis. more than 90% of malignant neoplasms of the oral cavity and oropharynx are squamous cell carcinomas of the lining mucosae with relatively rare neoplasms arising in minor salivary glands and soft tissues(2). the bcl-2-associated death promoter (bad) protein is a pro-apoptotic member of the bcl-2 gene family which is involved in initiating apoptosis (3). when bad is phosphorylated by akt/protein kinase b, it forms the bad-protein homodimer. this leaves bcl-2 free to inhibit baxtriggered apoptosis (4). mdm2 is a protein that normally inhibits the function of p53 by causing its degradation. if the dna damage is repaired successfully, quite ingeniously, p53 activates mdm2, whose product binds to and degrades p53, thus relieving the cellcycle block (5). p21 is a potent cyclin-dependent kinase inhibitor (cki). the p21 protein binds to and inhibits the activity of cyclin-cdk2, -cdk1, and -cdk4/6 complexes, and thus functions as a regulator of cell cycle progression at g1 and s phase. in addition to growth arrest, p21 can mediate cellular senescence (6) and it interacts with proliferating cell nuclear antigen (pcna) and (1)ph.d. student. department of oral diagnosis, college of dentistry, university of baghdad (2)assistant professor. department of oral diagnosis, college of dentistry, university of baghdad plays a regulatory role in s phase dna replication and dna damage repair, sometimes p21 is expressed without being induced by p53. this kind of induction plays a big role in p53 independent differentiation which is promoted by p21 (7). materials and methods the sample of the present study was forty formalin-fixed paraffin-embedded blocks of oscc cases. all were collected from the histopathological laboratory at maxillofacial surgery department at ramadi teaching hospital. demographical and clinical data provided by surgeon were obtained from the case sheets presented with tumor specimens, including information concerning patient's name, age, gender, clinical presentation, site of tumor, lymph node involvement, distant metastasis (if present). each formalinfixed paraffin-embedded specimen had serial sections prepared as follows: 5µm thickness sections were mounted on glass slides for routine haematoxylin and eosin staining (h&e), from each block of the studied sample and the control group for histopathological evaluation. three sections of 5μm for positive and negative tissue and technical control were taken and mounted on positively charged microscopic slides (biocare medical usa and afco brand china) to obtain a greater tissue adherence. h & e staining was used for reassessment of histopathological examination of the collected samples and control group. for each specific antibody (bad, mdm2, and p21, abcam-usa) j bagh college dentistry vol. 28(2), june 2016 an immunohistochemical oral diagnosis 35 the recommended dilution was applied (1/80, 1/50, and 1/250 respectively). specific expression was demonstrated by the absence of immunostaining in the negative control slides and its presence in recommended positive controls. any positivity in the examined slides for tumor cells the case consider positive, while if no positive expression where noted the case considered negative. the expression for all markers was evaluated semi-quantitatively. it was obtained by counting the number of tumor cells in 5 fields (using 40x objective in most represented areas of sections) and calculate the percentage of tumor cells that labeled as brown cytoplasmic and/or nuclear staining pattern (according to type of expression for each marker). labeling index for each field was calculated using the following equation: (number of positive cells/ number of total cells); the mean value of labeling indices for the five fields was considered to be the label index for the case. the scoring was done under light microscope and assigned to four categories: no expression (ne) = 0 expression, mild (mi) = 1-20 expression, moderate (mo) = 20-50 expression, strong (st) = 50-100 expression (figures 1, 2 and 3). chi-square test was applied for statistical assessment of clinicopathological and immunohistochemical findings to identify the significant or non-significant correlation between them at 95% confidence interval. figure 1: a, b and c immunohistochemical pattern of expression of bad figure 2: a, b and c immunohistochemical pattern of expression of mdm2 figure 3: a, b and c immunohistochemical pattern of expression of p21 a. positive nuclear expression in wd (40x) b. positive nuclear expression in md (40x) c. positive nuclear expression in pd (40x) a. positive cytoplasmic expression in wd (40x) b. positive cytoplasmic expression in md (40x) c. positive cytoplasmic expression in pd (40x) a. positive cytoplasmic expression in wd (40x) b. positive cytoplasmic expression in md (40x) c. positive cytoplasmic expression in pd (40x) j bagh college dentistry vol. 28(2), june 2016 an immunohistochemical oral diagnosis 36 results forty cases of oscc were included in the present study with age range between 20-85 years old and mean age 52.4 years old, including 26(65%) males and 14(35%) females. the total positive immunohistochemical expression of bad was found in 39 (97.5%) of the cases and as follows; strong in 13(32.5%) cases, moderate expression in 20(50%) cases and mild expression in 6(15%) cases; while negative expression was found in 1(2.5%) case. concerning the anatomical site and according to the number of the cases included in the present study, the recorded percentage of immunohistochemical expression of bad in the lower lip was positive moderate expression in 24(60%) cases. the highest percentage of positive bad immunohistochemical expression was in well differentiated scc as seen in 17(42.5%) cases, followed by moderately differentiated scc as seen in 16(40%) case. an equal positive bad immunohistochemical expression percentage was recorded in stage i & ii 14(35%) cases for each and 8(20%) cases in stage iii (table 1). the total mdm2 positive immunohistochemical expression was found in 39(97.5%) of the cases; including strong expression in 17(42.5%) cases, moderate expression in 17(42.5%) cases and mild expression in 5(12.5%) cases and negative expression was found only in 1(2.5%) case. most of the positive cases were located in lower lip in 24(60%) cases followed by the alveolus in 7(17.5%) of the cases. the highest percentage of positive mdm2 immunohistochemical expression in well differentiated scc in 18(45%) cases, followed by moderately differentiated scc in 16(40%) case. positive expression was recorded in 15(37.5%) cases of stage ii, followed by 13(32.5%) cases in stage i and 8(20%) cases in stage iii, while 4(10%) cases showed positive expression in stage iv (table 2). the total p21 positive immunohistochemical expression was found in 34(85%) of the cases and as follows; strong in 16(40%) cases, moderate expression in 12(30%) cases and mild in 6(15%) cases, while no expression was found in 6(15%) cases. the main percentage of positive p21 immunohistochemical expression was located within lower lip in 22(55%) cases followed by alveolus in 7(17.5%) of the cases. positive p21immunohistochemical expression was recorded in well differentiated scc in 17(42.5%) cases. concerning tumor stage, an equal percentage of positive p21expression shown in stage ii & stage i in 12(30%) cases and 7(17.5%) cases in stage iii, while 3(7.5%) cases recorded in stage iv, and negative expression was found in 6(15%) cases distributed among i, ii and iii cases (table 3). discussion understanding the molecular basis of oscc has increased rapidly over the past few years. knowing more about the pathogenesis of oscc is essential to improve patient's prognosis and treatment modalities. in this study, the expression of bad 39(97.5%) of cases indicate that bad phosphorylation is anti-apoptotic, phosphorelated bad by akt forming bad-protein heterodimer leaving bcl-2 free to inhibit bax-triggered apoptosis. mitochondrial unbounded bad molecules are then believed to interact with either bcl-2 or bcl-xl and neutralize their anti-apoptotic functions (8). it has been reported that mdm2 is associated with p53 gene products and may negatively affect the transcriptional activating function of p53. in spite of the absence of p53 assessment in the current study an elevated level of mdm2 expression was found which suggests a p53 independent role for mdm2 in the genesis of malignancies; this finding similar to those of (9,10). over expression of mdm2 protein may reflect a persistent response to dna damaging agents present in oscc patients and it can be oncogenic independently of p53 via stimulation the s – phase inducing transcription factor e2f1/dp1 or via inhibiting tumor suppressor protein prbmediated cell cycle arrest (11). p21protein mediates cell cycle arrest to secure against dna replication in cells with anchorage damaged molecules (12). p21 expression was reported to be correlated with tumor size, grade and stage (13). patients displaying loss of p21 had a significantly shorter overall survival rate and poor prognosis (14). the expression of p21 induces differentiation of normal and transformed cells; it has also been associated with terminal differentiation, senescence and apoptosis. the immuno-reactivity of p21 in this study was expressed in 34(85%) of the cases of oscc in areas of squamous differentiation in accord with its function of regulating differentiation of cells, this finding with agreement. the biological significance of the lack p21 expression in tumor cells remains to be elucidated (10). the p21 gene has a p53 transcriptional regulatory motif and the cells lacking functional p53 express very low level of p21. however, some studies indicate that p53 independent pathways may also lead to increase p21 expression. expression of p21 is predominant j bagh college dentistry vol. 28(2), june 2016 an immunohistochemical oral diagnosis 37 corresponds to the area of squamous differentiation and also detected in cells with wild type p53 but is often absent in cells lacking p53 activity (15). table 1: clinicopathological finding vs. immunohistochemical expression of bad clinicopathological parameter n (%) ne 1(2.5%) mi 6(15%) mo 20(50%) st 13(32.5%) total n (%) age group 0-9 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 40(100%) 10-19 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 20-29 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) 30-39 9(22.5%) 0(0%) 3(7.5%) 3(7.5%) 3(7.5%) 40-49 5(12.5%) 0(0%) 2(5%) 2(5%) 1(2.5%) 50-59 11(27.5%) 0(0%) 1(2.5%) 7(17.5%) 3(7.5%) 60-69 6(15%) 1(2.5%) 0(0%) 4(10%) 1(2.5%) 70-79 3(7.5%) 0(0%) 0(0%) 0(0%) 3(7.5%) 80-89 4(10%) 0(0%) 0(0%) 3(7.5%) 1(2.5%) gender male 26(65%) 1(2.5%) 4(10%) 13(32.5%) 8(20%) 40(100%) female 14(35%) 0(0%) 2(5%) 7(17.5%) 5(12.5%) clinical appearance ulcer 17(43%) 1(2.5%) 2(5%) 8(20.5%) 6(15%) 40(100%) mass 23(57.5%) 0(0%) 4(10%) 12(30%) 7(17.5%) anatomical site lower lip 24(57.5%) 0(0%) 3(7.5%) 13(30%) 8(20%) 40(100%) cheek 3(7.5%) 0(0%) 0(0%) 2(5%) 1(2.5%) f.o.m 3(7.5%) 0(0%) 1(2.5%) 1(2.5%) 1(2.5%) alveolus (mandible) 7(17.5%) 1(2.5%) 1(2.5%) 4(10%) 1(2.5%) tongue 1(2.5%) 0(0%) 0(0%) 0(0%) 1(2.5%) soft palate 2(5%) 0(0%) 1(2.5%) 0(0%) 1(2.5%) tumor grade wd 18(45%) 1(2.5%) 2(10%) 9(22.5%) 6(15%) 40(100%) md 16(40%) 0(0%) 2(5%) 7(17.5%) 7(17.5%) pd 6(15%) 0(0%) 2(5%) 4(10%) 0(0%) tumor stage i 14(35%) 0(0%) 1(2.5%) 6(15%) 7(17.5%) 40(100%) ii 15(37.5) 1(2.5%) 3(7.5%) 9(22.5%) 2(5%) iii 8(20%) 0(0%) 1(2.5%) 4(10%) 3(7.5%) iv 3(7.5%) 0(0%) 1(2.5%) 1(2.5%) 1(2.5%) j bagh college dentistry vol. 28(2), june 2016 an immunohistochemical oral diagnosis 38 table 2: clinicopathological finding vs. immunohistochemical expression of mdm2 clinicopathological parameter n (%) ne 1(2.5%) mi 5(12.5%) mo 17(42.5%) st 17(42.5%) total n (%) age group 0-9 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 40(100%) 10-19 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 20-29 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) 30-39 9(22.5%) 0(0%) 1(2.5%) 5(12.5%) 3(7.5%) 40-49 5(12.5%) 0(0%) 1(2.5%) 2(5%) 2(5%) 50-59 11(27.5%) 0(0%) 1(2.5%) 5(12.5%) 5(12.5%) 60-69 6(15%) 0(0%) 1(2.5%) 2(5%) 3(7.5%) 70-79 3(7.5%) 1(2.5%) 0(0%) 1(2.5%) 1(2.5%) 80-89 4(10%) 0(0%) 1(2.5%) 1(2.5%) 2(5%) gender male 26(65%) 1(2.5%) 2(5%) 11(27.5%) 12(30%) 40(100%) female 14(35%) 0(0%) 3(7.5%) 6(15%) 5(7.5%) clinical appearance ulcer 18(45%) 0(0%) 1(2.5%) 8(20%) 9(22.5%) 40(100%) mass 22(55%) 1(2.5%) 4(10%) 9(22.5%) 8(20%) anatomical site * lower lip 24(60%) 0(0%) 3(7.5%) 11(27.5%) 10(25%) 40(100%) cheek 3(7.5%) 0(0%) 0(0%) 2(5%) 1(2.5%) f.o.m 3(7.5%) 0(0%) 1(2.5%) 1(2.5%) 1(2.5%) alveolus (mandible) 7(17.5%) 0(0%) 0(0%) 3(7.5%) 4(10%) tongue 1(2.5%) 0(0%) 0(0%) 0(0%) 1(2.5%) soft palate 2(5%) 1(2.5%) 1(2.5%) 0(0%) 0(0%) tumor grade wd 18(45%) 0(0%) 0(0%) 11(27.5%) 7(17.5%) 40(100%) md 16(40%) 1(2.5%) 3(7.5%) 3(7.5%) 9(22.5%) pd 6(15%) 0(0%) 2(5%) 3(7.5%) 1(2.5%) tumor stage i 14(35%) 1(2.5%) 0(0%) 6(15%) 7(17.5%) 40(100%) ii 15(37.5%) 0(0%) 4(10%) 6(15%) 5(12.5%) iii 8(20%) 0(0%) 0(0%) 4(10%) 4(10%) iv 3(7.5%) 0(0%) 1(2.5%) 1(2.5%) 1(2.5%) * (chi square = 27.59, d.f. =15, p=0.0242) references 1. forastiere a, koch w, trotti a, et al. head and neck cancer. n engl j med 2001; 345: 1890–900. 2. barnes l, eveson jw, reichart p, sidransky d. pathology and genetics head and neck tumours. lyon: iarc press; 2005. pp. 45-51. 3. adachi m, imai k. the proapoptotic bh3-only protein bad transduces cell death signals independently of its interaction with bcl-2. cell death and differentiation 2002; 9(11): 1240–7. 4. ayllón v, cayla x, garcía a, fleischer a, rebollo a. the anti-apoptotic molecules bcl-xl and bcl-w target protein phosphatase 1alpha to bad. eur j immunol 2002; 32(7): 1847–55. 5. kumar v, abbas a, fausto n. robbins and cortan pathologic basis of diseases. 7th ed. st. louis: elsevier; 2006. 6. rodriguez r, meuth m. chk1 and p21 cooperate to prevent apoptosis during dna replication fork stress. mol biol cell 2006; 17 (1): 402–12. j bagh college dentistry vol. 28(2), june 2016 an immunohistochemical oral diagnosis 39 table 3: clinicopathological finding vs. immunohistochemical expression of p21 clinicopathological parameter n (%) ne 6(15%) mi 6(15%) mo 12(30%) st 16(40%) total n (%) age group 0-9 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 40(100%) 10-19 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 20-29 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) 30-39 12(30%) 2(5%) 2(5%) 4(105%) 2(5%) 40-49 5(10%) 0(0%) 1(2.5%) 2(2.5%) 2(5%) 50-59 11(27.5%) 3(7.5%) 1(2.5%) 1(2.5%) 6(15%) 60-69 5(12.5%) 1(2.5%) 0(0%) 2(5%) 2(5%) 70-79 3(7.5%) 0(0%) 0(0%) 0(0%) 3(7.5%) 80-89 4(10%) 0(0%) 2(5%) 2(5%) 0(0%) gender male 26(65%) 4(10%) 4(10%) 5(12.5%) 13(32.5%) 40(100%) female 14(35%) 2(5%) 2(5%) 7(17.5%) 3(7.5%) clinical appearance ulcer 17(42.5%) 4(10%) 4(10%) 4(10%) 5(12.5%) 40(100%) mass 23(57.5%) 2(5%) 2(5%) 8(20%) 11(27.5%) anatomical site lower lip 24(60%) 2(5%) 4(10%) 9(22.5%) 9(22.5%) 40(100%) cheek 3(7.5%) 1(2.5%) 0(0%) 1(2.5%) 1(2.5%) f.o.m 3(7.5%) 2(5%) 0(0%) 0(0%) 1(2.5%) alveolus (mandible) 7(17.5%) 0(0%) 2(5%) 1(2.5%) 4(10%) tongue 1(2.5%) 1(2.5%) 0(0%) 0(0%) 0(0%) soft palate 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) tumor grade * wd 18(45%) 1(2.5%) 3(7.5%) 5(12.5%) 9(22.5%) 40(100%) md 16(40%) 5(12.5%) 0(0%) 4(10%) 7(17.5%) pd 6(15%) 0(0%) 3(7.5%) 3(7.5%) 0(0%) tumor stage i 14(35%) 2(5%) 1(2.5%) 4(10%) 7(17.5%) 40(100%) ii 15(37.5%) 3(7.5%) 4(10%) 3(7.5%) 5(12.5%) iii 8(20%) 1(2.5%) 0(0%) 4(10%) 3(7.5%) iv 3(7.5%) 0(0%) 1(2.5%) 1(2.5%) 1(2.5%) *(chi square = 15.97, d.f. = 6, p= 0.0139) 7. bedelbaeva k, snyder a, gourevitch d, clark l, zhang x-m, leferovich j, cheverud jm, lieberman p, heber-katz e. lack of p21 expression links cell cycle control and appendage regeneration in mice. proceedings of the national academy sci 2010; 107 (11): 5845–50. 8. loro ll, johannessen ac, vintermyr ok. loss of bcl-2 in the progression of oral cancer is not attributable to mutations. j clin pathol 2005; 58(11): 1157–62. 9. iqbal m, akhtar u, nishioka m, sakamato k, reneslson l, akira y, minoru t. expression of p53, mdm2 and p21 proteins in betel quid and tobacco associated oral squamous cell carcinoma in bangladeshi population. oral med pathol 2005; 10: 23-31. 10. sathyan, km, nalinakumari kr, kannan s. h-ras mutation modulates the expression of major cell cycle regulatory proteins and disease prognosis in oral carcinoma. mod pathol 2007; 20(11): 1141-8. 11. matsumura t, yoshihama y, kimura t, shintani s, alcalde re. p53 and mdm2 expression in oral squamous cell carcinoma. oncol 1996; 53(4): 308-12. 12. tu hp, fu e, chen yt, wu mh, cheng lc, yang sf. expression of p21 and p53 in rat gingival and human oral epithelial cells after cyclosporine a treatment. j periodontal res 2008; 43(1): 32-9. 13. hafkamp hc, mooren jj, claessen sm, klingenberg b, voogd ac, bot fj, et al. p21 cip1/waf1 expression is strongly associated with hpv-positive tonsillar carcinoma and a favorable prognosis. mod pathol 2009; 22(5): 686-98. 14. buchynska lg, nesina ip, yurchenko np, bilyk oo, grinkevych vn, svintitsky vs. expression of p53, p21waf1/cip1, p16ink4a and ki-67 proteins in serous ovarian tumors. exp oncol 2007; 29(1): 49-53. 15. el-deiry ws, harper jw, o'connor pm. waf1/cip1 is indused in p53mediated g1 arrest and apoptosis. cancer res1994; 54:1169-74. j bagh college dentistry vol. 31(4), december 2019 association of 40 association of a genetic variant (rs689466) of cyclooxygenase-2 gene with chronic periodontitis in a sample of iraqi population suha a. dahash, b.d.s.(1) maha sh. mahmood, b.d.s, m.sc.(2) abstract background: periodontitis is a chronic inflammatory disease causing destruction of the tooth supporting structures, initiated by dental plaque and modified by environmental and genetic risk factors. cyclooxygenase-2 (cox-2) enzyme is responsible for the production of prostaglandin e2, an important mediator in the chronic periodontitis (cp) pathogenesis. polymorphisms in cox-2 gene have linked to cp in different populations. aim: to study the association between cyclooxygenase-2 single nucleotide polymorphism rs689466 (-1195a/g snp) and chronic periodontitis in a sample of iraqi population. methods: one hundred iraqi subjects divided into two groups: case group consisted of 70 cp patient (35 males and 35 females) with age range 30-55 years, and control group consisted of 30 racially matched healthy subjects (15 males and 15 females) with age range 30-50 years. clinical periodontal parameters including plaque index (pli), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal) were recoded for all participants. 3ml of venous blood was collected from each participant for isolating genomic dna. genotyping of the rs689466 in cox-2 gene was performed using polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp) method. results: the frequency of g allele carriers was significantly more prevalent in the case group compared to control group (p= 0.041), and allele g was associated with greater susceptibility for chronic periodontitis compared to allele a (or=1.4). conclusion: cox-2 (rs689466) polymorphism may be associated with increased chronic periodontitis susceptibility. key words: chronic periodontitis, cyclooxygenase-2, rs689466 polymorphism. (received: 10/8/2018; accepted: 4/9/2018) introduction chronic periodontitis (cp) is a complex, multifactorial inflammatory disease of the tooth supporting tissues leading to gradual irreversible tissue destruction and may eventually lead to tooth loss (1). the primary factor that initiates and maintains periodontal inflammation is the dental plaque biofilm that forms on teeth surfaces in the absence of oral hygiene (2). periodontitis develops from a pre-existing gingivitis which is reversible gingival inflammation. individuals are not equally susceptible to periodontitis, in other words; not all cases of gingivitis progress to periodontitis in the presence of plaque deposits (3). the inflammatory response is responsible for most of the tissue destruction in periodontitis. therefore, the nature of the host inflammatory-immune response is the major determinant of host susceptibility (4). susceptible individuals in whom gingivitis rapidly progress to periodontitis have a hyper inflammatory response characterized by increased production of proinflammatory mediators and oxidative stress (5-7). 1. master student, college of dentistry, university of tikrit. 2. professor, department of periodontics, college of dentistry, university of baghdad. many environmental and genetic factors influence the inflammatory response and the interaction of these factors determine whether the individual is susceptible to periodontitis or not (8). identification of the risk factors involved in the pathogenesis of periodontitis is important for better disease diagnosis and management (9). periodontitis has been shown to have an inherited basis of about 50%, meaning that genetic factors play an important role in disease susceptibility (10). genetic polymorphism in the molecules involved in periodontitis pathogenesis have been linked to increased risk for periodontitis in certain populations (11, 12). cyclooxygenase-2 (cox-2) enzyme is one of the most effective mediators in the pathogenesis of periodontitis via converting arachidonic acid to prostaglandins (13), it is the inducible form of the two cyclooxygenase isoforms (cox-1 and cox2) (14). bacterial endotoxins and proinflammatory cytokines stimulate cox-2 expression which in turn increases the production of prostaglandin e2 (pge2) in the periodontal tissues (15). pge2 causes more inflammation, tissue destruction and bone resorption. cox-2 expression is increased in periodontitis (16). polymorphisms (most commonly single nucleotide polymorphisms (snps)) in the cox-2 j bagh college dentistry vol. 31(4), december 2019 association of 41 gene may affect gene expression rate and thus periodontitis susceptibility (17). snps in the cox-2 gene that have been linked to periodontitis susceptibility include rs689466, rs20417 and rs5275 (18) in the present study we genotyped a sample of iraqi population for rs689466 (1195ــag) snp of cox-2 and tested the association of this snp with chronic periodontitis. materials and methods study design and subjects: this case-control study consisted of 100 iraqi subjects of similar ethnic backgrounds recruited from the department of periodontics, college of dentistry/university of baghdad and the iraqi national blood bank during the period from october 2017 to january 2018. informed consent was obtained from each participant, and a questionnaire was used to record the background information, dental and medical histories of the participants. subjects were divided into two groups: control group (30 periodontally healthy subjects) and chronic periodontitis group (70 cp patients) criteria of the international classification of periodontal diseases and condition were used for diagnosing chronic periodontitis patients (19). ethical approval was obtained from the ethical committee of the college of dentistry/university of baghdad. clinical periodontal examination: periodontal status of all the participants was examined by the same examiner using unc-15 periodontal probe and the following periodontal parameters were recorded: plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level. blood sample collection and dna isolation: 3ml of the venous blood was collected in ethylene diamine tetra acetic acid (edta) tube using venipuncture method. dna was isolated from the whole blood samples using gsync™ dna extraction kit (geneaid,taiwan) and following the manufacturer’s instructions. dna samples were quantified by using a nano-drop spectrophotometer then stored at 70ــ°c. genotyping of cox-2 rs689466 polymorphism using polymerase chain reaction-restriction fragment length polymorphism (pcr-rflp). polymerase chain reaction (pcr): pcr was performed using a ready to use mixture (accupower® pcr premix from bioneer/ korea) which is supplied in 0.2ml tubes, each tube contains taq polymerase (1u), deoxynucleoside triphosphates (dntps) each 250µm, 1.5mm mgcl2, stabilizer and tracking dye. dna sample and primers were added to the contents of the pcr premix tubes according to the manufacturer’s instructions, then the tubes were transferred to a thermal cycler to complete the pcr according to the following program: initial denaturation at 95°c for 5 minutes, 30 pcr cycles consisting of denaturation at 95°c for 30 seconds, annealing at 58°c for 45 seconds and extension at 72°c for 45 seconds followed by final extension at 72°c for 5 minutes. the following primers were used: forward primer 5’ccctgagcactacccatgat3’ and reverse primer 5’ccctgagcactacccatgat 3’ (17). the anticipated pcr product (273bp) was visualized using agarose gel electrophoresis on a 1.5% gel concentration captured under uv light (figure 1). figure 1: results of the agarose gel electrophoresis of the pcr product for samples 1 to 33; m, dna marker. restriction fragment length polymorphism (rflp): pvull enzyme (sibenzyme, russia) was used for digesting the pcr product in order to produce fragments of different lengths to differentiate between different genotypes of rs689466 (1195a/g snp). in the presence of allele g at the position 1195ــ, pvull enzyme cuts the 273bp pcr product into two fragments (220bp + 53bp), while in the absence of allele a the enzyme couldn’t cut, thus the 273bp fragment remains the same. j bagh college dentistry vol. 31(4), december 2019 association of 42 10 µl the pcr product of each sample was mixed with 1µl of the pvull enzyme, 2µl of the se buffer, 1µl of the bsa and 1µl of the deionized distilled water. then incubated in a thermal cycler at 37°c for 3 hours. the digestion product was separated by agarose gel electrophoresis using 3% gel concentration and visualized under uv light. the three genotypes were differentiated according to the band size. 273bp band indicated aa genotype, 220bp band indicated gg genotype and the presence of both 220bp and 273bp bands indicated ag genotype. 53bp was not visible. (figure 2). figure 2: agarose gel electrophoresis of restriction digestion product for samples (1-24). m, dna marker; 273bp, aa genotype; 220bp, gg genotype; 273+220, ag genotype. statistical analysis the statistical analysis system (sas) program was used to perform statistical analysis. descriptive statistics included: number, percentage, range, mean and standard deviation. ttest was used to compare between means and chisquare to compare between percentages and genotype distributions. results were considered significant when the probability p≤0.05. odds ratio (or) was used to express the association of genotypes with disease risk. or=1 indicates no association, or<1 indicates reduced risk and or>1 indicates increased risk. results characteristics of the study subjects (cp group and control group) are given in table 1. the mean age (±sd) for the control group was 42.03 (±5.70), and for cp group was 45.86 (±7.12). male: female number was 15:15 in the control group and 35:35 in the cp cases. table 1: characteristics of study subjects characteristics of controls and cp cases control group(n=30) cp group(n=70) age range 30-50 30-55 mean (±sd) 42.03 (±5.70) 45.86 (±7.12) gender male no (%) 15(50%) 35(50%) female no (%) 15(50%) 35(50%) table 2 shows the clinical periodontal parameters. the difference in the pli and gi was significant between cases and controls (p=0.00146 and 0.0016 for pli and gi respectively). the percentage of bleeding sites (bop score 1) in the cp group was 61.71%. the mean probing pocket depth (ppd) (±sd) in the cp group was 3.094(±0.642), and the mean clinical attachment level (cal) (±sd) was 4.33(±0.913). table 2: clinical periodontal parameters control group (n=30) cp group (n=70) p-value mean pli (±sd) 0.827 (±0.228) 1.979 (±0.245) 0.00146 mean gi (±sd) 0.631(±0.158) 1.632 (±0.298) 0.0016 bop score 1 (%) -- 61.71% -- mean ppd (±sd) --3.094mm (±0.642) -- mean cal (±sd) --4.33mm (±0.913) -- j bagh college dentistry vol. 31(4), december 2019 association of 43 table 3 shows cox-2 rs689466 genotypes and alleles and their prevalence in the study subjects. 74% of the people were aa homozygous, 23% were ag heterozygous and 3% gg homozygous. the dominant model (combining ag+gg in one group called allele g carriers) was used. table 3: distribution of cox-2 rs689466 genotypes and alleles in the study population. genotypes frequency in the study population total aa homozygous 74 (74%) n=100 ag heterozygous 23 (23%) gg homozygous 3 (3%) allele g carriers (ag+gg) 26 (26%) alleles a (wild) 171 (85.5%) 2n=200 g (mutant) 29 (14.5%) distribution of the cox-2 rs689466 genotypes and alleles in cp cases and controls is illustrated in table 4. aa homozygous was significantly higher in the control group compared to cp group (p=0.047). the dominant model (ag+gg) revealed that allele g carriers were significantly more prevalent in the cp cases compared to controls (0.041), and possess greater risk for disease as indicated by elevated odd ratio (1.6). table 4: distribution of cox-2 rs689466 genotypes and allele frequency between controls and chronic periodontitis cases. cox-2 rs689466 controls cp cases or p-value genotypes n=30 n=70 aa no (%) 24 (80%) 50 (71.43%) 0.625 0.047 (ag+gg) no (%) 6 (20%) 20 (28.57%) 1.6 0.041 allele frequency 2n=60 2n=140 a no (%) 53 (88.33%) 118 (84.29%) 0.708 0.093 g no (%) 7 (11.67%) 22 (15.71%) 1.411 0.1447 table 5 shows the distribution of the cox-2 rs689466 genotypes and alleles between males and females. the prevalence of aa genotype was equal for both males and females (74%, p=1.00: or=1). the prevalence of the mutant allele carriers (ag+gg) was also equal (26%) in both genders with a non-significant difference in allele frequency between males and females (allele a frequency was 85% in males and 86% in females, p=0.887: or=0.92. while allele g frequency was 15% in males and 14% in females, p=0.887: or=1.08). table 5: distribution of cox-2 rs689466 genotypes and allele frequency between males and females. cox-2 rs689466 males females or p-value genotypes n=50 n=50 aa no (%) 37 (74%) 37 (74%) 1 1.00 (ag+gg) no (%) 13 (26%) 13 (26%) 1 1.00 allele frequency 2n=100 2n=100 a no (%) 85 (85%) 86 (86%) 0.92 0.887 g no (%) 15 (15%) 14 (14%) 1.08 0.887 discussion periodontitis is a complex disease, although microbial dental plaque is the initiating factor, other environmental and genetic risk factors play important role in the pathogenesis. identification of these risk factors is important for effective disease prevention and management(2). as shown in (table 2), the significant difference in the pli and gi levels between controls and cases is explained by the fact that dental plaque is the primary cause of periodontal disease (2, 11, 20). in the pathogenesis of periodontitis, the induction of cox-2 by bacterial endotoxins and pro-inflammatory cytokines results in the production of increased amounts of prostaglandin e2 (pge2) in periodontal tissues (15). pge2 is a potent inflammatory mediator and a stimulator of osteoclastogenesis and bone resorption (21, 22). j bagh college dentistry vol. 31(4), december 2019 association of 44 also it stimulates the production of matrix metalloproteinases causing further tissue destruction. it has been shown that the concentration of pge2 in the gingival crevicular fluid is correlated with periodontal disease severity and reduced after treatment. cox-2 is over expressed in periodontitis (16, 23), while the inhibition of cox-2 reduces the rate of bone resorption and periodontal disease progression (24). variations in the cox-2 gene have been linked to many inflammatory and proliferative diseases. cox-2 gene polymorphisms may influence periodontitis susceptibility by influencing the host’s inflammatory response. the most common type of genetic polymorphisms are the single nucleotide polymorphisms (snps) in which a single nucleotide at a specific point is substituted be another nucleotide (25). three snps rs689466, rs20417 and rs5275 in the cox-2 gene have been reported to be associated with periodontitis risk in different populations. however, the results were inconsistent (12). in the present study the cox-2 rs689466 was investigated in a sample of iraqi population and tested for association with chronic periodontitis. this snp has been previously investigated in chinese, european, and north indian populations (18, 26-28). the results of our study showed that the distribution of the snp genotypes in the iraqi population (table 3) is different from genotype distributions of the same snp in the previously mentioned populations. aa homozygous was the most prevalent genotype in both controls and cases. however, it was significantly more prevalent in controls compared to cp cases and associated with reduced disease risk, while allele g carriers were significantly more prevalent in cp group compared to controls and associated with higher disease risk as indicated by elevated odd ratio (table 4). a comparison between males and females showed a nearly equal distribution of cox-2 rs689466 genotypes and alleles between males and females (table 5) suggesting that gender specific genetic effect may not contribute to the overall periodontitis risk, this agrees with michalowicz et al (10). as a conclusion, this study revealed that the genetic variant (rs689466) in the promotor area of cox-2 gene may be associated with cp susceptibility in iraqi population. however, the study should be replicated in a larger independent sample of similar racial background. references 1. huang n, gibson fc. immuno-pathogenesis of periodontal disease: current and emerging paradigms. current oral health reports. 2014;1(2):12432. 2. aljehani ya. risk factors of periodontal disease: review of the literature. international journal of dentistry. 2014;2014:182513. 3. van der velden u, abbas f, armand s, loos bg, timmerman mf, van der weijden ga, et al. java project on periodontal diseases. the natural 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2000;58(4):250-64. 26. xie c-j, xiao l-m, fan w-h, xuan d-y, zhang j-c. common single nucleotide polymorphisms in cyclooxygenase-2 and risk of severe chronic periodontitis in a chinese population. journal of clinical periodontology. 2009;36(3):198-203. 27. schaefer as, richter gm, nothnagel m, laine ml, noack b, glas j, et al. cox-2 is associated with periodontitis in europeans. j dent res. 2010;89(4):384-8. 28. prakash g, umar m, ajay s, bali d, upadhyay r, gupta kk, et al. cox-2 gene polymorphisms and risk of chronic periodontitis: a case–control study and meta-analysis. oral diseases. 2015;21(1):38-45. الخالصة التهاب دواعم السن هو مرض التهابي مزمن يصيب االنسجة الداعمة للسن مسببا ضررا دائما فيها. االلتهاب ينشأ بشكل أساسي من تراكم الخلفية العلمية: ي يقوم الذ e2مسؤول عن انتاج بروستاجالندين 2الصفيحة الجرثومية على سطح االسنان ويخضع لتأثير العوامل البيئية والوراثية. انزيم السايكلواوكسيجينيز يرتيط بزيادة خطر المرض في مجاميع عرقية معينة. 2بدورهام في إمراضية التهاب دواعم السن. تعدد اشكال النيوكليوتيدة لجين السايكلواوكسيجينيز ومرض 2لواوكسيجينيز لجين السايك (rs689466) أجريت هذه الدراسة للتحقق من وجود عالقة بين تعدد اشكال النيوكليوتيدة في الموقع أهداف الدراسة: التهاب دواعم السن المزمن في عينة من المجتمع العراقي. من 35من الذكور و 35مريض ) 70عراقي تم تقسيمهم إلى مجموعتين: مجموعة الحاالت تكونت من 100شملت هذه الدراسة على المواد وطرق العمل: سنة, ال يشكون من 50-30من االناث( بمعدل اعمارمن 15من الذكور و 15شخص ) 30من االناث( مصابين بالتهاب دواعم السن ومجموعة السيطرة تكونت ف عند التسبير, التهاب دواعم السن. مؤشرات ما حول االسنان التي تم تسجيلها للمشاركين شملت: مؤشر الصفيحة الجرثومية, مؤشر التهاب اللثة, مؤشر النز مل من الدم الوريدي من كل مشترك. تم استخالص الحمض النووي)الدنا( من عينات الدم لغرض 3ريري. تم جمع عمق الجيوب اللثوية و مستوى االرتباط الس باستخدام طريقة: 2لجين السايكلواوكسيجينيز (rs689466) التنميط الجيني. تم إجراء التنميط الجيني لتعدد أشكال النيوكليوتيدة في الموقع polymerase chain reaction-restriction fragment length polymorphism الكهربائي باستخدام جل االكاروز. والترحيل كما ان (p=0.041)كان مرتفعا معنويا في حاالت التهاب دواعم السن المزمن مقارنة بمجموعة السيطرة gأظهرت النتائج أن تردد الحاملين ألليل النتائج: .a (1.4or= )مرتبط بزيادة احتمالية االصابة بالتهاب دواعم السن مقارنة باألليل gأليل قد يرتبط بزيادة القابلية لإلصابة بالتهاب دواعم السن المزمن. 2زلجين السايكلواوكسيجيني (rs689466) تعدد أشكال النيوكليوتيدة في الموقعاالستنتاج: j bagh college dentistry vol. 32(1), march 2020 the impact of histo 51 the impact of histopathological celiac disease activity on dental enamel defects and dental caries zainab qasim m. al-obaidi (1), nada jafer m.h. radhi (2) abstract background: celiac disease is an autoimmune chronic disease that affects the human’s intestine and subsequently reflects its effect on the entire body health by retardation the absorption and immune mediated complications cause the involvement of oral health. the present study intended to evaluate the impact of the histopathological disease activity upon dental enamel defects and dental caries. subjects and methods: forty celiac-diseased patients aged 7-11 years were collected from 3 different teaching hospitals in baghdad classified by means of the histopathological activity of the intestinal disease according to modified marsh-rostami classification. dental enamel defects were measured by aine’s classification, while dental caries experience and severity were measured using d1-4mfs/t and d1-4mfs/t. results: the majority of the sample came with partial villous atrophy of the small intestine (marsh iii-a) and almost half of the sample were with no celiac disease specific dental enamel defects (aine’s 0), while aine’s i was the most predominant than aine’s ii. most missed surfaces due to dental caries in permanent teeth came with marsh ii. conclusion: the more the severity of celiac disease histopathological activity the more the severity of celiac specific dental enamel defects and the less experienced dental caries. key words: celiac disease, histopathological activity, dental enamel defects, dental caries. (received: 10/10/2019; accepted: 13/11/2019) introduction celiac disease (cd) is a chronic hereditary autoimmune inflammatory disease leading to intestinal damage and malabsorption associated with serious health consequences.(1) cd can introduce itself by multiple signs and symptoms starting from diarrhea, weight loss and abdominal pain to extra-intestinal manifestations including dental enamel defects ded.(2,3) the only available and acceptable treatment is lifelong strict gluten free diet gfd.(1) endoscopy for cd diagnosis doesn’t provide definitive image for intestinal pathology (4) during which multiple biopsies are taken from different sites of the small intestine usually duodenum to submit them for histopathological assay.(5) small intestine has a major role in digestion, secretion and absorption; numerous mucosal folds containing villi increase the surface area of absorption and digestive enzymes production.(6) histological features of the duodenal disease are villous atrophy, crypt hyperplasia, increase a number of intraepithelial lymphocytes and decrease in height of enterocytes.(7) (1) master student, department of pedodontics and preventive dentistry, college of dentistry university of baghdad. (2) assist. prof. department of pedodontics and preventive dentistry, college of dentistry university of baghdad. intestinal epithelial damage is caused by both innate and adaptive immune responses and that intraepithelial lymphocytes, those are elicited by the inflammation caused by gluten and mediated genetically and production of variant immunoglobulin such as tissue transglutaminase, anti-endomesial and anti-gliadin.(8)modified marsh-rostami index had been developed to describe intestinal mucosal damage.(9) orally, dental enamel defects ded can be identified in some cd patients and this plays a vital role for dentists to play pointing to the disease for diagnosis.(10) when any impaired function of the ameloblasts occurred due to environmental or nutritional deficiency factors, enamel formation would get impaired too.(11) a study by abdul-wahid et al (12) revealed an increase in the presence of unspecific dental enamel defects by the application of the modified developmental defects of enamel index for 102 cd patients aged 2-35 years compared to the control group in primary and permanent dentitions while dental caries was experienced at higher extent in the primary teeth only. higher ded in cd children was observed as compared to children devoid from the disease (10,13,14) in contrast to dental caries that was experienced at lesser extent in cd children.(13) another study showed no significant difference in prevalence of ded between cd children and others without the disease.(15,16) another study reported no significant difference in caries experience in cd children.(16) j bagh college dentistry vol. 32(1), march 2020 the impact of histo 52 the aim of the current study was the estimation of the essential role that the oral cavity plays as a gate of the gastrointestinal tract at which the health of each may logically affects the other’s, thus cd was studied in children with mixed dentition to evaluate cd histopathological activity impact on ded and dental caries. subjects and methods ethical approval was gained from the ethical committee of college of dentistry/university of baghdad and consents forms were gained from the patients' parents to be included. the sample of the present study consisted of 40 celiac-diseased (cd) children aged 7-11 years according to the last birthday and date of examination, half of them had been just diagnosed and the rest was committed to gluten free diet. patients should have been devoid from any other diseases. the study was carried out from november 2018 to march 2019. patients had been collected from pediatric consultation sections of the gastroenterology of three different teaching hospitals in baghdad. the disease had been diagnosed according to the european society of pediatric gastroenterology, hepatology and nutrition guidelines (17) histopathological findings were collected from the patients’ medical reports by means of grading according to modified marsh index for histological cd activity.(9) all histopathological examinations of all patients included were accomplished in the histology laboratory of gastroenterology and hepatology teaching hospital/baghdad. oral examination had been carried out following the basic principles of who (1997).(18) dental enamel defects (ded) had been evaluated descriptively by aine’s classification for cd specific dental enamel defects criteria (10) as shown in table (1); those should have been distributed symmetrically and chronologically in all dental arches when all teeth were examined in all dental quadrants. dental caries dmfs/t and dmfs/t and severity d1-4/d1-4 were examined and recorded according to muhlemann.(19) descriptive statistics was applied, level of significance was set at 0.05 by spss program version 21. table 1: aine’s criteria for celiac disease specific dental enamel defects. grade description 0 no defects meet the criteria i defect in color of enamel. single or multiple creamy, yellow or brown opacities with clearly defined or diffuse margins; in addition a part or the entire surface of enamel is without glaze. ii slight structural defects, enamel surface rough, filled with horizontal grooves or shallow pits; light opacities and discoloration may be found; in addition a part or the entire surface of enamel is without glaze. iii evident structural defects, a part or the entire surface of enamel rough and filled with deep horizontal grooves which vary in width or have large vertical pits; large opacities of different colors or strong discoloration may be in combination. iv severe structural defects, the shape of the tooth changed: the tips of cusps are sharp-pointed and/or the incisal edges are unevenly thinned and rough; the thinning of the enamel material is easily detectable and the margins of the lesions are well defined; the lesion may be strongly discolored. results the sample contained 22 boys and 18 girls, there was no significant difference concerning gender among the groups (chisquare = 3.671; p = 0.160) and the sample had been considered as one age group. grading of cd histopathological activity of the current sample revealed that it was devoid from marsh i and marsh iii-c while marsh ii, iii-a and iii-b were presented as 3 (7.50%), 25 (62.50%) and 12 (30.00%) respectively aine’s classification of dental enamel defects (ded) specific for cd that was used in the present sample revealed that 19 (47.5%) of children were with no defects (grade 0) followed by 17 (42.5%) children with grade i and 4 (10%) children with grade ii. neither aine’s iii nor ain’s iv had been found in the present sample marsh grading of histopathological disease activity in relation to aine’s grading of cd specific dental enamel defects revealed a significant difference among the present grades where there were no enamel defects in marsh ii. on the other hand, the least children with aine’s 0 grades were observed in marsh iii b in contrast to aine’s ii enamel defects which were the most frequent in marsh iii-b category (table 2). caries severity and experience were found in d4, ds and dmfs components among marsh ii as compared to marsh iii-a and iii-b but no j bagh college dentistry vol. 32(1), march 2020 the impact of histo 53 significant difference was observed; the same is applied to ds component concerning primary teeth (table 3). multiple comparisons by games-howell as anova post hoc test were applied to ms according to the available three marsh grades showing no significant difference between marsh iii-a and marsh iii-b mean differences (p>0.05) while high significant differences concerning marsh ii mean difference with both marsh iii-a and iii-b (p<0.01) was noticeable (table 4). dental caries experience and severity showed no significant difference in relation to cd dental enamel defects but the mean values of d4, ds, dmfs and dmft for deciduous teeth showed lower results in aine’s ii than both aine’s i and aine’s 0. the same was applied to d4 and ds for permanent teeth as shown in table (5) but no statistical differences were found. table 2: celiac disease dental enamel defects according to aine’s classification in relation to the histopathological disease activity measured by modified marsh-rostami classification. *fissure exact probability test **significant<0.05 table 3: dental caries experience and severity for primary and permanent teeth according to marsh grading aine’s classification fept* p total 0 i ii marsh ii n. 3.00 0.00 0.00 9.452 0.025** 3.00 % 15.79 0.00 0.00 7.50 iii a n. 14.00 10.00 1.00 25.00 % 73.68 58.82 25.00 62.50 iii b n. 2.00 7.00 3.00 12.00 % 10.53 41.18 75.00 30.00 total n 19.00 17.00 4.00 40.00 % 47.50 42.50 10.00 100.00 dental caries marsh grading ii iii-a iii-b f p mean se mean se mean se d1 0.333 0.333 0.080 0.080 0.000 0.000 1.102 0.343 d2 1.333 1.333 0.240 0.166 0.917 0.434 2.069 0.141 d3 1.333 1.333 1.480 0.361 1.500 0.469 0.011 0.989 d4 6.333 6.333 6.040 1.498 5.667 1.676 0.015 0.985 ds 9.333 9.333 7.840 1.520 7.750 1.670 0.053 0.949 ms 0.000 0.000 1.400 0.614 2.083 1.145 0.514 0.602 fs 0.000 0.000 0.000 0.000 0.167 0.167 1.177 0.319 dmfs 9.333 9.333 9.160 1.785 10.000 2.514 0.033 0.968 dmft 5.333 5.333 5.080 0.848 5.667 0.956 0.072 0.931 d1 0.667 0.667 1.520 0.289 1.167 0.241 0.772 0.470 d2 0.000 0.000 0.880 0.211 1.250 0.446 1.359 0.269 d3 2.000 0.000 1.200 0.294 0.750 0.179 1.357 0.270 d4 4.333 2.603 1.600 0.408 1.417 0.645 2.073 0.140 ds 7.000 2.082 4.680 0.577 4.583 0.783 0.931 0.403 ms 3.333 3.333 0.000 0.000 0.000 0.000 8.556 0.001 fs 0.000 0.000 0.040 0.040 0.833 0.833 1.068 0.354 dmfs 10.333 5.364 5.000 0.648 5.417 1.171 2.334 0.111 dmft 4.667 0.667 4.440 0.597 4.417 0.733 0.010 0.990 j bagh college dentistry vol. 32(1), march 2020 the impact of histo 54 table 4: multiple comparisons of missing component (ms)of dmfs among the three available marsh grades. games-howell test for ms among marsh grades (i) marsh (j) marsh mean difference (i-j) p iii-a iii-b 0.00000 1.000 ii -3.33333 0.002** iii-b ii -3.33333 0.003** ** highly significant < 0.01 table 5: dental caries experience and severity in primary and permanent teeth in relation to aine’s grades of celiac disease enamel defects. aine’s grade 0.00 1.00 2.00 f p dental caries mean se mean se mean se d1 0.053 0.053 0.118 0.118 0.000 0.000 0.247 0.782 d2 0.684 0.375 0.412 0.173 0.250 0.250 0.325 0.724 d3 1.211 0.347 1.647 0.428 2.000 1.414 0.472 0.627 d4 5.895 1.629 6.882 1.857 2.250 1.931 0.681 0.512 ds 7.842 1.794 8.824 1.954 4.500 2.630 0.506 0.607 ms 1.053 0.614 2.059 0.964 1.250 1.250 0.432 0.652 fs 0.000 0.000 0.118 0.118 0.000 0.000 0.665 0.520 dmfs 8.789 1.907 11.00 2.565 5.750 3.376 0.606 0.551 dmft 5.053 0.966 5.824 1.102 4.000 2.309 0.326 0.724 d1 1.421 0.299 1.353 0.331 1.000 0.408 0.173 0.841 d2 0.789 0.237 1.059 0.337 1.000 0.707 0.223 0.801 d3 1.263 0.285 1.118 0.331 0.500 0.289 0.610 0.549 d4 2.263 0.675 1.353 0.383 1.000 1.000 0.885 0.421 ds 5.053 0.664 4.882 0.701 3.500 1.555 0.475 0.625 ms 0.526 0.526 0.000 0.000 0.000 0.000 0.540 0.588 fs 0.053 0.053 0.000 0.000 2.500 2.500 4.363 0.113 dmfs 6.000 1.084 4.882 0.701 6.000 3.342 0.337 0.716 dmft 4.737 0.606 4.235 0.662 4.000 1.826 0.205 0.815 discusion celiac disease (cd) had been proved to be accompanied by several systemic and dental defects. dental enamel defects (ded) are permanent and won’t be corrected after gluten free diet (gfd). early diagnosis of cd patients by dentists can be performed by ded since most cd patients are atypical.(14, 20) in the present study almost half of the sample had no cd specific enamel defects, however, most of the defects were enamel opacities (aine’s i). this comes in agreement with a study by shahraki et al when studying wider range of sample age (3-16 years) and larger sample size (65) of cd patients.(14) structural abnormalities were also present at lesser extent as aine’s ii was in 10% of the sample which contained no ain’s iii or iv and this comes in an agreement with a turkish study that reported no aine’s iii or iv in 60 cd patients’ ages 6-16 years.(21) the present study revealed that the least intestinal damage (marsh ii) came with no cd specific ded while the more intestinal damage (marsh iii-a and iii-b) came with more cd specific ded and this comes in contrast with what aine et al showed by studying adults enamel defects in relation to the degree of histological damage although children cannot be compared to adults.(22) yet, no specific mechanism was established explaining ded in cd patients;(23) nutritional deficiency specially hypocalcemia and a normal serum concentration of calcium had been found during diagnosis of cd children,(13) immune mediated as the primary causative factor (25,26) and ded as a hereditary condition and/or affected by environmental circumstances.(24) dental caries is one of the most mentioned infectious diseases human beings suffer from.(27) an iraqi study illustrated an increased salivary iga in caries free children as compared to caries active in the same age group of the present study (28) while another iraqi study illustrated an important protective roles of salivary immunoglobulins especially iga and igm against dental caries in normal kindergarten children,(29) since cd is an autoimmune disease that salivary immunoglobulins are logically suspected to be j bagh college dentistry vol. 32(1), march 2020 the impact of histo 55 elevated and dental caries was, in the present study, experienced at lesser extent in a more severe intestinal damage and saliva by itself can be used non-invasively to mirror blood.(30) it is wise to investigate salivary immunoglobulins seeking for dental caries protective factors in cd children since patients with increased ded had decreased dental caries.(21) the present study has arrived at the conclusion that the more the severity of the intestinal mucosal damages in cd children the more the presence of specific dental enamel defects, although no severe enamel defects or intestinal damage 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https://www.ncbi.nlm.nih.gov/pubmed/?term=campisi%20g%5bauthor%5d&cauthor=true&cauthor_uid=17537244 https://www.ncbi.nlm.nih.gov/pubmed/?term=bufo%20p%5bauthor%5d&cauthor=true&cauthor_uid=17537244 https://www.ncbi.nlm.nih.gov/pubmed/?term=compilato%20d%5bauthor%5d&cauthor=true&cauthor_uid=17537244 https://www.ncbi.nlm.nih.gov/pubmed/?term=massaccesi%20c%5bauthor%5d&cauthor=true&cauthor_uid=17537244 https://www.ncbi.nlm.nih.gov/pubmed/?term=catassi%20c%5bauthor%5d&cauthor=true&cauthor_uid=17537244 https://www.ncbi.nlm.nih.gov/pubmed/?term=muzio%20ll%5bauthor%5d&cauthor=true&cauthor_uid=17537244 https://www.ncbi.nlm.nih.gov/pmc/articles/pmc1891285/ https://www.ncbi.nlm.nih.gov/pubmed/?term=husby%20s%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=koletzko%20s%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=korponay-szab%c3%b3%20ir%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=mearin%20ml%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=mearin%20ml%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=phillips%20a%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=shamir%20r%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=troncone%20r%5bauthor%5d&cauthor=true&cauthor_uid=22197856 https://www.ncbi.nlm.nih.gov/pubmed/22197856 https://www.ncbi.nlm.nih.gov/pubmed/22197856 https://www.ncbi.nlm.nih.gov/pubmed/?term=freeman%20hj%5bauthor%5d&cauthor=true&cauthor_uid=30013741 https://www.ncbi.nlm.nih.gov/pmc/articles/pmc6040035/ https://www.ncbi.nlm.nih.gov/pmc/articles/pmc6040035/ https://www.ncbi.nlm.nih.gov/pubmed/?term=aine%20l%5bauthor%5d&cauthor=true&cauthor_uid=1350136 https://www.ncbi.nlm.nih.gov/pubmed/?term=m%c3%a4ki%20m%5bauthor%5d&cauthor=true&cauthor_uid=1350136 https://www.ncbi.nlm.nih.gov/pubmed/?term=reunala%20t%5bauthor%5d&cauthor=true&cauthor_uid=1350136 https://www.ncbi.nlm.nih.gov/pubmed/1350136?report=abstract https://www.hindawi.com/14519083/ https://www.hindawi.com/36487518/ https://www.hindawi.com/36487518/ https://www.hindawi.com/30428713/ http://www.ncbi.nlm.nih.gov/sites/entrez?orig_db=pubmed&db=pubmed&cmd=search&term=13%5bvolume%5d%20and%201%5bpage%5d%20and%201982%5bpdat%5d%20and%20fraser%20d%5bauthor%5d http://www.ncbi.nlm.nih.gov/sites/entrez?orig_db=pubmed&db=pubmed&cmd=search&term=13%5bvolume%5d%20and%201%5bpage%5d%20and%201982%5bpdat%5d%20and%20fraser%20d%5bauthor%5d http://www.ncbi.nlm.nih.gov/sites/entrez?orig_db=pubmed&db=pubmed&cmd=search&term=87%5bvolume%5d%20and%2012%5bissue%5d%20and%201100%5bpage%5d%20and%202008%5bpdat%5d%20and%20pastore%20l%5bauthor%5d https://www.ncbi.nlm.nih.gov/pubmed/?term=s%c3%b3%c3%b1ora%20c%5bauthor%5d&cauthor=true&cauthor_uid=26712243 https://www.ncbi.nlm.nih.gov/pubmed/?term=arbildi%20p%5bauthor%5d&cauthor=true&cauthor_uid=26712243 https://www.ncbi.nlm.nih.gov/pubmed/?term=rodr%c3%adguez-camejo%20c%5bauthor%5d&cauthor=true&cauthor_uid=26712243 https://www.ncbi.nlm.nih.gov/pubmed/?term=beovide%20v%5bauthor%5d&cauthor=true&cauthor_uid=26712243 https://www.ncbi.nlm.nih.gov/pubmed/?term=beovide%20v%5bauthor%5d&cauthor=true&cauthor_uid=26712243 https://www.ncbi.nlm.nih.gov/pubmed/?term=marco%20a%5bauthor%5d&cauthor=true&cauthor_uid=26712243 https://www.ncbi.nlm.nih.gov/pubmed/?term=hern%c3%a1ndez%20a%5bauthor%5d&cauthor=true&cauthor_uid=26712243 https://www.ncbi.nlm.nih.gov/pubmed/26712243 http://jidai.ir/article-1-1605-en.pdf j bagh college dentistry vol. 32(1), march 2020 the impact of histo 56 الخالصة الخلفية: إن مرض مناعي ذاتي كداء الحنطة يؤثر على صحة األمعاء لدى اإلنسان و ينعكس على صحة جسمه بشكل كامل عن طريق سوء إختالل تكوين ميناء األسنان و تسوس األسنان.صحة الفم ك ضاعفات ذات أسباب مناعية تؤثر علىاإلمتصاص و م ( سنة من ثالث مستشفيات مختلفة في بغداد و بإعتماد التقسيم 117حنطة بأعمار )مريض مصاب بداء ال 40األشخاص والطرق: ثم جمع المعدل و خلل ميناء marsh rostami لغشاء األمعاء حسب تقسيم المرضية سب شدة المرض بالنسبة لفعاليته من الناحية النسيجيةح .الخاص بداء الحنطة كذلك تجربة تسوس األسنان وشدتها aineاألسنان عن طريق تقسيم كان aine iiكان األغلب في العينة . aine’s 0.i aineالعينة كان لديها غالبية. marsh iii-b من العينة كانت تعاني أن غالبيةالنتائج: .aine ii كانت مصاحبة . أغلب األسنان الدائمية المفقودة بسبب التسوس marsh ii-bاألغلب عند المصابين ب اإلستنتاج: كلما زادت شدة المرض نسيجياً كلما زادت شدة اإلختالل في تكوين ميناء األسنان و قل تسوس األسنان.الكلمات المفتاحية: داء المرضية, مارش, إختالل ميناء األسنان, آين, تسوس األسنان. –الحنطة, الفعالية النسيجية 30. wesal f.doc j bagh college dentistry vol. 25(1), march 2013 an evaluation of orthodontics, pedodontics and preventive dentistry181 an evaluation of three fissure sealants microleakage with presence or absence of bonding agent through time intervals (in vitro study) ali m. el-mosawi, b.d.s. (1) wesal a. al-obaidi, b.d.s, m.sc. (2) abstract background: pit and fissure sealant have been considered an outstanding adjunct to oral health care in the decrease of occlusal caries onset and low progression. the aims of this in vitro study were to evaluate the marginal microleakage of three different types of fissure sealants (sdi, tg and tetric n-flow) by time interval, one day and 45 days, in the presence or absence of bonding agent among maxillary and mandibular teeth. materials and methods: seventy two sound human maxillary and mandibular first premolar teeth were collected which were free from obvious carious lesions. the teeth were randomly divided into two main equal groups, group (1) and group (2), each group consists of (36) teeth involving equal numbers of maxillary and mandibular teeth. the first group incubated for one day, the second incubated for (45) days. each group divided into two subgroup; one of them treated with bonding agent while the other without. then each subgroup was treated with three different materials which were; tg sealant (without fluoride) group (a), sdi sealant (containing fluoride) group (b) and tetric nflow (flowable composite) group (c). each one consist of six teeth involving three maxillary and three mandibular. then dye penetration tested by using methylene blue dye, then the teeth cleaned and sectioned by sectioning device and tested under microscope. results, the results had shown that, group (c+) in both incubation periods have no microleakage (score 0), but there was an opposite effect when using bonding agent with sealant materials not containing filler particles that showed a significant increase in the microleakage rate as shown in groups (a+ and b+). the opposite effect was seen also when used sealant materials containing filler particles but without bonding agent that seen in group (c) during both incubation periods that showed significant increasing in microleakage rate. while the effect of fluoride was very clear in decreasing significantly the microleakage rate after (45) days of incubation in both groups that treated with and without bonding agent (groups b and b+). concerning the anatomical variation, there were no significant changes in most groups regarding the microleakage rate. conclusions: results had shown that the microleakage can be prevented by using of flowable composite containing nanofillers that treated with bonding agent after etching of enamel with 35% phosphoric acid gel. keywords: fissure sealants, microleakage, bonding agent, time intervals. (j bagh coll dentistry 2013; 25(1):181-187). introduction fissure sealants was considered in this study, because there are different opinions related to the sealant materials in a positive or negative direction and there is a controversy in the uses of sealant materials, also pit and fissure sealant has been considered an important way to oral health care in decreasing of occlusal caries onset and low progression by its sealing ability that prevents accumulation of food remnant in the fissures (which is a nutrient for bacteria) and prevention of bacterial leakage to the weakest point of enamel, thus preventing dental caries (1), also the benefit of fluoride within sealant materials, in addition to, another study showed that if the sealant dislodged from its location the remnant of sealant materials may remain intruded within the tag and reduce entrance of food particles and bacteria (2), and there were different types of sealant have similar or different sealing ability (3). (1) msc student, university of baghdad, college of dentistry, pedodontic and preventive dentistry department. (2) professor university of baghdad, college of dentistry, pedodontic and preventive dentistry department. sealing treatment could be considered as a minimal invasive and cost effective treatment, and because there were no previous available iraqi studies related to fissure sealants, so this study was conducted. materials and methods seventy two sound human maxillary and mandibular first premolar teeth were collected which were extracted for orthodontic purpose of young age ranged between fifteen to twenty years old of age. teeth should have fully developed roots, free from obvious carious lesions, morphological defects, restorations, and with deep pits and fissures that are typically indicated for sealant placement.the selected (72) teeth were kept in (0.1%) thymol solution to prevent microbial growth after cleaning of all teeth from any remnant. thenconstruction of the acrylic block was done by mounting each tooth in acrylic block after that, the occlusal surfaces were cleaned with a disposable prophylaxis brush with tapered end by using a low speed contra angle hand piece (5000 rpm) for ten seconds. j bagh college dentistry vol. 25(1), march 2013 an evaluation of orthodontics, pedodontics and preventive dentistry182 the teeth were randomly divided into two main equal groups; group (1) and group (2), each group consisting of (36) teeth involving (18) maxillary first premolar teeth and (18) mandibular. the first group was incubated for one day, while the second incubated for (45) days. each group was divided into (2) subgroups, each one consisting of (18) teeth involving equal number of maxillary and mandibular teeth. one group was treated with bonding agent, whiles the other group without. then each group was subdivided into (3) subgroups depending on three different sealant materials used which are; sdi (containing fluoride) sealant; tetric n-flow (flowable composite), and tg (without fluoride) sealant. each subgroup consists of (6) teeth involving (3) maxillary first premolar and (3) mandibular. before starting the material application technique, a constant distance between tooth surface and source of washing water and drying air from triple syringe should be provided for standardization purpose. the distance between the tooth and light curing source, also it is very important to be adjusted for standardization purpose.no invasive technique was used prior to sealant placement. the occlusal surfaces were cleaned then the enamel in the area of pits and fissures (occlusal surface) was treated with different techniques and sealed with different types of resin based sealant (table 1). table 1: different treatment groups. groups sealant materials conditioning technique a tg (without fluoride) acid etch a+ tg acid etch + bonding agent b sdi (with fluoride) acid etch b+ sdi acid etch + bonding agent c tetric n-flow (with fillers) acid etch c+ tetric n-flow acid etch + bonding agent in group a, the occlusal fissures were etched with 35 percent phosphoric acid gel etchant (sdi supper etch , australia) for (15 to 20) seconds, flushed with an air-water spray (oil-free air and deionized distilled water) for (5) seconds until no traces of etchant gel color could be visible on the surface, then dried by air syringe for (3) seconds. the occlusal surface becomes ready for sealant placement. in group a+, the same steps of etching in group a was applied to group a+, but after etching, the bonding agent (3m esps, fifth generation) was applied to the etched occlusal surface with a disposable brush, blowing gently with air from an air syringe for (2) seconds for thinning the adhesive and waiting for (2) seconds allowing bonding agent to infiltrate into the etched surface fissure. then curing for (20) seconds with visible light cure unit (astralis 3, vivadent). all steps mentioned in group a and a+ for enamel conditioning techniques were exactly used in other groups b and b+, c and c+ respectively. before sealant placement, determination of the deepest point of pits and fissures should be done, to make sure that sectioning would be through this point for standardization purpose. the path of microtome sectioning was marked by fine pen on the occlusal surface.the sealant material in group a and a+ was (tg pit and fissure sealant) that applied immediately after drying of substrate surface, by using of needle tip (supplied within the kit) and a fine probe was used by moving it gently through applied sealant material for better adaptation and air bubble escaping. then curing of sealant was done for 30 seconds (as manufacture instructions) with visible light cure unit under standardization technique. two types of aging process were used to accommodate the similar environment subjected to sealant materials within the oral cavity that affect the microleakage.immediately after completion of sealant applications, the teeth immersed and stored in the artificial saliva which was prepared previously, and the teeth were incubated within a container of artificial saliva at room temperature for a period of one day, this is for (group 1), while (group 2) incubated for (45) days. the teeth were subjected to artificial aging by thermocycling in water, the teeth were cycled manually between two water baths (4). one of them maintains the temperature at 52 ± 4 oc, the other water bath maintain the temperature at 5 ±2 oc. the immersion time was (30) seconds ± 5 in each bath(5), and the number of cycles employed was 15 cycles in each day (15 cycles for group 1 and 675 cycles for group 2). after thermo cycling procedure, the teeth were prepared for dye penetration. the specimens' apices were covered with compound wax (if any apex was exposed). after that, each tooth was painted with two layers of nail varnish except the occlusal surface. then they were immersed in methylene blue dye for four hours(6), after that the teeth were rinsed thoroughly under tap water, varnishes were then scrubbed and the teeth allowed to dry, to be prepared for the next step which is sectioning of teeth.the crowns of teeth were sectioned longitudinally in a buccolingual direction through an imaginary line between two j bagh college dentistry vol. 25(1), march 2013 an evaluation of orthodontics, pedodontics and preventive dentistry183 points determined previously. the sectioning was done by using hard tissue microtome (struersminitom). each section was examined under electronic microscope, images were captured. a ranked scale method was used to measure microleakage, the rank explained in table 2 (7). table 2: microleakage scores results the dye penetration represent the microleakage which was presented by scores for all groups that incubated for one day and for (45) days (table 3 and 4 respectively). table 3: microleakage scores for all the tested groups incubated for one day and (1) day. micro leakage scores one day c+ c b+ b a+ a no. of teeth group 0 1 3 1 0 0 1 maxill.teeth 0 1 2 2 1 1 2 0 1 3 2 0 0 3 0 1 3 1 0 1 1 mandi. teeth 0 1 3 1 1 2 2 0 1 3 2 0 1 3 table 4: microleakage scores for all thetested groups incubated for one day and (45) days. c+ c b+ b a+ a no. of teeth group 45 days 0 3 1 1 3 0 1 maxill.teeth 0 3 0 1 2 0 2 0 2 1 0 2 1 3 0 3 0 0 1 1 1 mandi. teeth 0 2 0 0 1 1 2 0 2 0 1 1 1 3 the frequency of each group was shown in (fig. 1) and (fig. 2). most frequency of score (0) appear in group (c+) during both incubated periods (in this group the type of material was tetric n-flow which is flowable composite treated with bonding agent). figure 1: frequency of microleakage scores among groupsof teeth incubated for one day. figure 2: frequency of microleakage scores among groups of teeth incubated for (45) days. the results of dye penetration measurement were expressed by descriptive statistic, the lowest mean of microleakage appear in group (c+) in both incubated periods which is (0.00).the results of microleakage means of each group can be compared with other groups to be easier by presenting the percentage of means which are shown in (fig. 3) and (fig. 4).the comparisons of microleakage means between two different conditioning techniques are presented in table (5). regarding groups incubated for one day, it was found that the microleakage mean value was significantly higher in group (b+) than group (b) for one day incubation, also it was significantly higher in group (a+) than group (a), and it was significantly higher in group (c) than group (c+) regarding groups incubated for (45) days. anova was used to compare between groups treated with different types of materials through score criteria 0 no dye penetration 1 dye penetration into the occlusal third of the enamel-sealant interface. 2 dye penetration into the middle third of the interface. 3 dye penetration in to the apical third of the interface. j bagh college dentistry vol. 25(1), march 2013 an evaluation of orthodontics, pedodontics and preventive dentistry184 figure 3: means percentage of microleakage among groups of teeth incubated for one day. figure 4: means percentage of microleakage among groups of teeth incubated for (45) days. table 5: microleakage among groups of teeth with and without using of bonding agent through the same type ofmaterial and the same period of incubation. comparison of significant t-value ±sd mean no. studied groups bonding agent incubation period sig p-value df ns 0.209 10 -1.342 0.516 0.33 6 a+ with (1) day 0.753 0.83 6 a without hs 0.001 10 4.781 0.408 2.83 6 b+ with 0.548 1.50 6 b without non 10 non 0.000 0.00 6 c+ with 0.000 1.00 6 c without s 0.030 10 2.535 0.816 1.67 6 a+ with (45) days 0.516 0.67 6 a without ns 0.599 10 -0.542 0.516 0.33 6 b+ with 0.548 0.50 6 b without hs 0.000 10 -11.180 0.000 0.00 6 c+ with 0.548 2.50 6 c without the same conditioning technique and the same incubation period as presented in table (6),within the groups incubated for one day and treated with bonding agent, the three different materials showed a highly significant difference regarding the microleakage means. least significant difference (lsd) test was needed to show where the significance had occurred between groups that presented in table (7). results had shown highly significant differences within group (a+ and b+), (b+ and c+) for one day incubation, (a+ and c+), (a and c) and (b and c) for (45) days incubation. concerning the comparisons between twodifferent incubation periods among the same type of sealant materials and the same conditioning technique as presented in table (8). the results showed that groups (b+) and (b) that incubated for one day had microleakage mean values which weresignificantly higher than that in groups incubated for (45) days. to compare between whole maxillary and mandibular teeth treated with the same types of materials, the same conditioning techniques and the same incubation periods, as presented in table (9). table 6: analysis of variancetest comparison among all groups. sig. p-value df f groupsstudied bonding agent incubation period hs 0.000 2 99.615 c+ b+ a+ with (1)day ns 0.116 2 2.500 c b a without hs 0.000 2 15.000 c+ b+ a+ with (45)days hs 0.000 2 25.577 c b a without j bagh college dentistry vol. 25(1), march 2013 an evaluation of orthodontics, pedodontics and preventive dentistry185 table 7: least significant difference among studied groups treated with different types of materials during the same period of incubation and the same conditioning technique. lsd studied groups bonding agent incubation period sig. p-value mean difference hs 0.000 -2.500 a+ b+ with (1)day ns 0.150 0.333 a+ c+ hs 0.000 2.833 b+ c+ s 0.01 1.333 a+ – b+ with (45)days hs 0.000 1.667 a+ – c+ ns 0.317 0.333 b+ – c+ ns 0.599 0.167 a – b without hs 0.000 -1.833 a – c hs 0.000 -2.000 b – c table 8: microleakage among groups of teeth with different incubation periods through the same material and the same conditioning technique. comparison of significant t-value ±sd mean no. studies groups incubation periods bonding agent sig. p-value df hs 0.007 10 -3.381 0.516 0.33 6 a+ (1) day with 0.816 1.67 6 a+ (45) days hs 0.000 10 9.303 0.408 2.83 6 b+ (1) day 0.516 0.33 6 b+ (45) days non 10 non 0.000 0.00 6 c+ (1) day 0.000 0.00 6 c+ (45) days ns 0.664 10 0.447 0.753 0.83 6 a (1) day without 0.516 0.67 6 a (45) days s 0.010 10 3.162 0.548 1.50 6 b (1) day 0.548 0.50 6 b (45) days hs 0.000 10 -6.708 0.000 1.00 6 c (1) day 0.548 2.50 6 c (45) days table 9: microleakage among different types of teeth (maxillary and mandibular first premolars). comparison of significant t-value ±sd mean no. studied groups sig. p-value df ns 0.730 70 0.347 1.068 1.06 36 maxillary teeth 0.971 0.97 36 mandibular teeth (score 0) (score 1) (score 3) figure 5: photograph view of ground sections for different scores (arrows), (x 500). the results had shown non-significant differences between maxillary and mandibular first premolar teeth regarding the microleakage mean values. the dye penetration and microleakage scores were determined by microscopic examination, and some photographs were taken and presented in figures (5). discussion the most important result in this study concerning the bonding agent regarding the microleakage reduction; presented by using of flowable composite with bonding agent (group c+) in both times interval, in which there was no any dye penetration (score 0, mean = 0). this j bagh college dentistry vol. 25(1), march 2013 an evaluation of orthodontics, pedodontics and preventive dentistry186 result may be attributed to the effect of bonding agent and the presence of filler particles together.the efficacy of bonding agent on reducing microleakage may be attributed to the combination of both adhesive forces (micromechanical adhesion by tag formation with enamel surface and chemical forces with sealant materials).while the efficacy of filler particles on reducing microleakage may be due to decreasing in the thermal expansion and polymerization shrinkage of sealant materials making it more closely approximate that of natural tooth structure, in addition to that, the fillers help indecreasing the polymerization shrinkage of underneath bonding agent (8, 9).but in group (c) and due to absence of bonding agent, there was an opposite effect of flowable composite on microleakage reduction which was very obvious in group ( c ) by both time interval. in group ( c ), the significant elevation of microleakage rate may be due to the presence of filler particles itself; when sealant material applied to the etched enamel surface, the filler particles will interfere with infiltration of the material to the microholes of etched enamel resulting in less penetration and weakened the attachment which can be distorted easily by dimensional changes of material (polymerization and thermal changes) leading to the broking of marginal integrity ending in penetration of dye. therefore, the microleakage in group ( c ) was significantly increased with time from less microleakage within group incubated for one day, to obvious increasing in microleakage within group incubated for (45) days due to increasing of thermal dimensional change by effect of thermocycling (10,11).while there was an opposite effect of bonding agent when used with the sealant materials which were free of filler particles by increasing the microleakage mean values significantly in group (b+) more than that of group (b) that incubated for one day, and in group (a+) more than that of group (a) that incubated for (45) days; and this result may be due to the absence of filler particles (which act as a barrier that decreasing the curing light penetration to underneath bonding agent) and may lead to increasing the effect of double polymerization shrinkage of bonding agent that exposed to double curing times, which disturbs the marginal integrity and increase dye penetration (9).concerning the time interval of sealant materials;when compared the microleakage means of sdi type of sealant material between groups ( b ), ( b+ ) in both incubation periods; the results showed obvious significant jumping in reduction of microleakage mean values with increasing the time, which may be attributed to the fluoride content of sealant material that precipitate to enamel surface, and because there is a continuous release of fluoride ion from sealant material to the superficial layer of enamel that may obliterate any microgap between the material and enamel within the tags formed leading to intimate contact of material within the tags and become more resistant to dislodgement which occur by thermal dimensional changes through the time and thus decreasing the microleakage, this opinion suggested by other studies(8,12).while the results of group (a) and (a+), in which the sealant material was plane, without filler particles and without fluoride, had shown that the microleakage mean value was increased by the time which was significantly higher in group (a+) incubated for (45) days than group (a+) incubated for one day. this result may be attributed to higher dimensional changes of sealant material through the time (thermal change and polymerization shrinkage), due to absence of filler particles and due to absence of fluoride (10). concerning different types of sealant materials; the result showed that group (c+) was the best group that have no dye penetration in both incubation periods. concerning the maxillary and mandibular teeth, results of this study had shown that both types of teeth exhibit similar marginal sealing ability and further studies were needed to conform this finding to larger sample size. references 1. simonsen rj. pit and fissure sealant: review of the literature. pediatr dent 2002; 24 (5): 393-414. 2. griffin s, gray s, malyitz d, gooch b, caries risk in formerly sealed teeth. amer j dent 2009; 107(4): 65. 3. pardi v, sinhoreti ma, pereira ac, ambrosano gm, meneghimmde c. in vitro evaluation of microleakage of different materials used as pit-andfissure sealants. braz dent j 2006; 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adolescent, 8th ed. mosby, affiliate of elsevier, 2004. 9. yap a, son m, siow k. postgel shrinkage with pulse activation and soft start polymerization. op dent 2002; 27: 81-7. 10. kim j, shin c, park k. long-term evaluation of sealants applied with an invasive technique. amer j dent 2008; 6:21 11. herle g, joseph t, varma b, jayanthi m. comparative evaluation of glass ionomer and resin based fissure sealant using noninvasive and invasive techniques – a sem and microleakage study. j indi socipedo and prev dent 2004; 22(2): 56-62. 12. das u, prashanth s. a comparative study to evaluate the effect of fluoride releasing sealant cured by visible light, argon lasers and light emitting diode curing units: an in vitro study. j indi socipedo and prev dent 2009; 5: 119. mithaq f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 59 the value of ultrasound and color doppler ultrasonography in the evaluation of periapical lesions in comparison to histopathological and/or surgical findings mithaq a. zebun, b.d.s. (1) ahlam a. fattah, b.d.s., m.sc. (2) abstract background: imaging techniques play a very important role in the specialty of endodontic. the ultrasonographic technique is non-expensive procedure, safe, and reproducible. the aim of the study was to determine the sensitivity, specificity, and accuracy of ultrasound and color doppler ultrasonography in evaluation of periapical lesions (cyst, granuloma, mixed lesion “cyst within graulomas mass”, and abscess. subject, material and method: the sample consists of prospective study for 64 iraqi participants who attended karbalaa specialized center for dentistry (males & females). those patients were diagnosed clinically and radiographically as having periapical lesions of dental origin. they were examined by real time ultrasound and color doppler ultrasonography with echographic predilection about the type of the lesion based on three parameters measured by ultrasound including: content, outline, and the vascularity. the echographic diagnosis was compared to the final histopathological and /or surgical findings obtained from the periapical surgeries. results: the sensitivity, specificity and accuracy of ultrasound diagnosis were respectively as follow: for periapical cyst, they were 92.3%, 96.1%, and 95.3%. while for periapical granulomam, they were 87.0%, 92.7%, and 90.6%. for mixed lesions, they were 66.7%, 98.4%, and 96.9% and lastly for periapical abscess, they were 92.0%, 97.4%, and 95.3%. the ultrasound diagnosis in our study had an overall agreement of 89% between ultrasound diagnosis and final diagnosis based on histopathological and/ or surgical findings. conclusion: ultrasound is a noninvasive, low cost, and complementary method for examination and diagnosis of periapical lesions and there is correlation of ultrasonographic findings with histopathological and /or surgical findings for final diagnosis. key words: periapical lesions, ultrasound, color doppler. (j bagh coll dentistry 2013; 25(special issue 1):59-66). introduction periapical lesions resulting from necrotic dental pulp are among the most frequently occurring pathologies found in the alveolar bone, exposure of the dental pulp to bacteria and their by-products, acting as antigens, may elicit non specific inflammatory responses as well as specific immunological reactions in the periradicular tissues, and cause the formation of periapical lesion (1,2). radiology is the first, but not the only, method used to identify intraand extra-osseous jaw lesions (3,4). clinical examination and radiographs alone cannot differentiate between cystic and non cystic lesions. being able to distinguish between the two may be of importance in predicting treatment failure (5), and it is very important to accurately diagnose the periapical lesions and exclude any rare chance of neoplastic occurrence (6). computerized tomography (ct) can be used to make a differential diagnosis between cystic and non cystic lesions (7, 8). unfortunately, routine use of ct is associated with high dosage of radiation, even though dose reduction methods have been established (9). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. magnetic resonance imaging (mri) is useful in the diagnosis, but it is not practical in the dental field. ultrasound has no ionizing radiation, no known harmful effects at the energies and doses used, in addition the technique is widely available and inexpensive (10). materials and methods the study sample consists of 64 iraqi patients (males and females) with periapical lesions referred for treatment to kerbalaa specialized centre between september 2011 and april 2012. their age ranged between (15-60) years old. the ultrasound examination was performed by using a philips of hi 11 xe ultrasound system with 7.5 mhz linear array probe in (al-hussein general hospital). the parameters measured by ultrasound were as shown in figures (1, 2, 3, and 4): 1texture of the lesion: the interpretation of grey values on an image is based on a qualititative comparison of the echo intensity with that of normal tissue. hypoechoic or transonic is an area with low echo intensity; anechoic is an area where no reflection occurs (i. e. any area filled with fluid), and hyperechoic is an area which has high echo intensity (11). j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 60 2vascularity: by the color power doppler, the vascularization within the lesion can be seen. a differential diagnosis between cystic lesion and granuloma may be done based on the following principles: cystic lesion is a transonic, well defined cavity filled with fluid and with no evidence of internal vascularization at the color power doppler, while the granuloma is a distinct lesion shows hyperechoic texture and internal vascularization with out well defined contour. 3the margin of the lesion: if it is regular or irregular. figure 1: ultrasound of periapical cyst show hypoechoic texture, well defined margin and reinforced bone figure 2: uultrasound of periapical granuloma show hyperechoic texture and vascularization (blue and red spots) figure 3: ultrasound of mixed periapical cyst/granuloma show hypoechoic and avascular center with hyperechoic and vascular periphery figure 4: ultrasound of periapical abscess show irregular margin and hypoechoic texture statistical data analysis or (odds ratio) to measure the strength of association between 2 categorical variables, such as the presence of certain us criteria and having a specific final diagnosis, the odds ratio (or) was used. for example or for the association between having a hypoechoic texture and having a final diagnosis of periapical cyst, equals the ratio of the odds of having the specific us criteria versus lacking it among cyst cases to the similar odds among non-cyst cases. having periapical cyst + bc ad d c b a or == presence of specific us criteria + a b c d sensitivity is the conditional probability that a diseased person has a positive result. specificity is the conditional probability that a disease-free person has a negative test result. positive predictive value (ppv) is the conditional probability that a person with a positive test result is truly diseased. negative predictive value (npv) is the conditional probability that a person with a negative test result is truly free of the disease. accuracy (percent agreement) is the proportion of true results among all test results (positive and negative) (12) results as shown in table (1): the us diagnosis had an overall accuracy (agreement) of 89% with the final diagnosis. the us diagnosis was most accurate in periapical abscess (highest agreement) and least accurate for mixed lesion (lowest agreement). j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 61 as shown in table (2): three us criteria, namely: hypoechoic texture, avascular pattern, and well defined margin were tested for their strength of association in predicting a final diagnosis of periapical cyst (pac). the presence of a well defined margin on us was the strongest criteria among the three tested. it increased the risk of having pac by 294 times. coming second in importance was hypoechoic texture, which increased the risk of positive diagnosis of pac by 69.8 times. avascular pattern ranked third in importance. it increased the risk of having pac by 24.1%. all the three tested us characteristics had a statistically significant association with diagnosis of pac as shown in table (3) the us criteria, namely: hyperechoic texture, vascular pattern, and the absence of well defined margin were tested for their strength of association in predicting a final diagnosis of periapical granuloma (pag). the vascular pattern on color doppler us was the strongest criteria among the three tested. a positive vascular pattern increased the risk of having pag by 266.7 times. coming second in importance was hyperechoic texture, which increased the risk of positive diagnosis of pag by 84.4 times. the absence of well defined margin on us was the least important among the three. the vascular pattern and hyperechoic texture on us had a statistically significant association with diagnosis of pag, while the irregularity of the lesion margin did not have statistical association with the diagnosis of pag. as shown in table (4): four us criteria, namely: hypoechoic texture, anechoic texture, avascular pattern, and the absence of well defined margin were tested for their strength of association in predicting a final diagnosis of paa. the avascular pattern was the strongest criteria among the four tested, this increased the risk of having paa by 80.6 times. coming second in importance was the anechoic texture which increased the risk of having paa by 62.7 times. the absence of well defined margin ranked third in importance that it increased the risk of having paa by 29.0, while the hypoechoic texture did not have statistical association with the diagnosis of paa. as shown in table (5) three us criteria, namely: mixed texture (hypoechoic center and hyperechoic periphery), mixed vascularity (avascular center and vascular periphery) and the absence of well defined margin were tested for their strength of association in predicting a final diagnosis of mixed lesion. the mixed texture and mixed vasculariy increased the risk of having mixed lesion by 120 times, while the absence of well defined margin did not have statistical association with the diagnosis of periapical mixed lesion. as shown in table (6): for periapical cyst (pac): two us criteria had a perfect sensitivity (100%).these criteria are hypoechoic texture and avascular pattern which are most useful when being negative since it can exclude possible presence of pac with 100% confidence (negative predictive value). the most specific us criterion was a well defined margin 96.1%. a well defined margin was also the criterion associated with highest accuracy (95.3%). an us diagnosis of pac had an overall accuracy of 95.3%, sensitivity of 92.3%, and a specificity of 96.1%. as shown in table (7): for periapical granuloma (pag): the most sensitive us criteria was the absence of well defined margin 91.3% which is most useful when being negative since it can exclude the possibility of being pag with 96.8% confidence(negative pretest probability). the most specific us criterion was the vascular pattern 97.6. the vascular pattern was also the criterion associated with highest accuracy (93.8%). an us diagnosis of pag had an overall accuracy of 90.6%, sensitivity of 87% and specificity of 92.7%. as shown in table (8): for periapical abscess (paa): 1. two us criteria had a perfect sensitivity (100%).these criteria are the absence of well defined margin and the avascular pattern which are most useful when being negative since it can exclude possible presence of paa with 100% confidence (negative predictive value). 2. the most specific us criterion was the anechoic texture (100%). 3. the anechoic texture was the criterion associated with highest accuracy (78.1%). 4. an us diagnosis of paa had an overall accuracy of 95.3%, sensitivity of 92% and specificity of 97.4%. as shown in table (9): for periapical mixed lesions: the most sensitive us criteria was the absence of well defined margin 100% which is most useful when being negative since it can exclude the possibility of being mixed pal with 100% confidence (negative pretest probability). j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 62 two us criteria were the most specific. these criteria were the mixed texture and mixed vascularity, each criterion had specificity of 98.4%. the mixed texture and mixed vascularity were the criteria associated with highest accuracy (96.9%). an us diagnosis of mixed pal had an overall accuracy of 96.9%, sensitivity of 66.7% and specificity of 98.4%. discussion ultrasound is easy, reproducible, and the equipment is relatively cheap compared to the other advanced imaging modalities. the images obtained are easy to read once the observer is trained. by obtaining a real time image, a working diagnosis can be made without delay and it also prevents unnecessary exposure of the patient to ionizing radiation (8, 13). from a biological standpoint , in experimental and clinical studies, no adverse effect of us waves have been shown to occur in the tissues as a consequence of echographic examination, and even if the effect of repeated echographic examination is less certain, the risks entailed by radiography are much greater (14,15,16).the possibility of identifying lesion content before any surgical procedure can be obtained by using us examination, using the higher frequency (7.5 mhz) in the technique to increase the signals penetration of the lesion (17). the current study used sample size (n=64) and a clear methodology relating the us diagnostic criteria to final diagnosis obtained by histopathology and / or surgical assessment. allowing for an accurate reporting of validity parameters of each us criteria, making the us as an excellent guide for the surgeon. in the present study four pathological types of pal were identified. the most commonly identified lesion was paa in two fifth of the sample (39.1%) followed by pag in more than one third (35.9%). ranked third in frequency was pac reported in one fifth (20.3%) of the sample. a rare finding was a mixture of periapical cyst and granuloma in only 4.7% of the sample. the us diagnosis in our study had an overall agreement of 89% with the final diagnosis based on histopathological and /or surgical evaluation. the agreement was higher for paa (95.8%) compared to pac and pag (85.7% and 87.0% respectively). dib et al in 1996 in their study on a sample of 72 patients with intraosseous lesions of the jaws reported an overall agreement of us ranging between 92.3% for lesions with solid content, 73.9% for lesions with liquid content, 92.8% for lesions with mixed content, and 7.7% for lesions with dense liquid content. other pioneer studies based on very small sample size reached to a conclusion that us in combination with color doppler were sensitive and very useful in differentiating between pac and pag and correlated well with the histological findings of the pals; however no validity parameters were reported because of the small sample size (16,18,19). the conclusions that can be drawn from this study are: 1. this study supported the fact that real time imaging ultrasound as a new imaging technique that can be used in endodontic field for the study of periapical lesions. 2. us is a good diagnostic tool for differentiation of pals (cyst, granuloma, abscess, and cystic cavity within granuloma) based on ultrasonic selected criteria including; echo content, vascularity, and lesion margin. 3. us was highly sensitive in the diagnosis of pac (92.3%), followed by paa (92.0%), then pag (87.0%), while the sensitivity of us diagnosis of mixed pal was relatively moderate (66.7%). 4. us was highly specific in the diagnosis of mixed pal (98.4%), followed by paa (97.4%), then pac (96.1%), and lastly the specificity of us diagnosis of pag was 92.7%. 5. the us diagnosis in our study had an overall agreement of 89% with the final diagnosis based on histopathological and /or surgical evaluation. the agreement was higher for paa (95.8%) compared to pac (85.7%) and pag (87.0%), and it was less for mixed cyst/granuloma periapical lesions (66.7%). 6. the strength of association (or) was greater in paa (437.0) followed by in pac (294.0) then in mixed pal (120) and lastly in pag (84.4). references 1. liapatas s, nakou m, rontogianni d. inflammatory infiltrate of chronic periradicular lesions: an immunohistochemical study. int endod j 2003; 36(7):464-71. 2. ricucci d, mannocci f, ford tr. a study of periapical lesions correlating the presence of a radiopaque lamina with histological findings. oral surg oral med oral pathol oral radiol endod 2006; 101(3): 389-94. 3. underhill te, katz jo, pope tl et al. radiologic findings of diseases involving the maxilla and mandible. ajr 1992; 159:345-50. 4. weber al. imaging of cysts and odontogenic tumors of the jaw: definition and classification. radiol clin north amer 1993; 31:101-12. j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 63 5. nair r. new perspective on radicular cyst: do they heal? intern endod j 1998; 31, 155-60. 6. shah n, sarkar c. plasmacytoma of anterior maxilla mimicking periapical cyst. endod dent traumatol 1992; 8:39–41. 7. trope m, pettigrew j, petras j, barnett f, tronstad l. differentiation of radicular cysts and granulomas using computerized tomography. endodontics and dental traumatology 1989; 5: 69-72. 8. cotti e, vargiu p, dettori, mallarini g. computerized tomography in the management and follow-up of extensive periapical lesion. endod dent traumatol 1999; 15:186 9. dula k, mini r, van der stelt pf, lambrecht jt, schneeberger p, buser d. hypothetical mortality risk associated with spiral computed tomography of the maxilla and mandible. european j oral sciences 1996; 104: 503-10. 10. whaites e. essentials of dental radiography and radiology. 3rd ed. edinburg: elsevier science limited chirchil livingstone; 2003. 11. auer lm, van velthoven v. intraoperative ultrasound imaging in neurosurgery. berlin: springer-verlag. 1990. pp.1-11. 12. sorlie de. medical biostatistics and epidemiology: examination and board review. 1st ed. norwalk, connecticut, appleton and lange: 1995, 47-88. 13. agarwal v, logani a, shah n. the evaluation of computed tomography scans and ultrasounds in the differential diagnosis of periapical lesions. j endod 2008; 34:1312-5. 14. liebeskind d, koenisberg m, koss l, raventos c. morphological changes in the surface characteristics of cultured cells after exposure to diagnostic ultrasound radiology 1981; 138,419-23. 15. martin ao. can ultrasound cause genetic damage? j clinical ultrasound 1984; 12: 11-20. 16. cotti e, campisi g, ambu r, dettori c. ultrasound real time imaging in the differential diagnosis of periapical lesions. int endod j 2003; 36:556-63. 17. dib ll, chammas mc, torloni h. ultrasonography evaluation of bone lesions of the jaw. oral surgery oral medicine oral pathology 1996; 82: 3:351-7. 18. cotti e, campisi g, garau v, puddu g. anew technique for the study of periapical lesions: ultrasound real time imaging. intern endod j 2002; 35: 148-152. 19. cotti e, simbola v, dettori c, campisi g. echographic evaluation of bone lesions of endodontic origin: report of two cases in the same patient. joe 2006; 32(9): 901-905. table 1: agreement between us and final diagnosis final diagnosis periapical granuloma periapical cyst periapical abscess mixed periapical cyst granuloma total n n % n % n % n % n % u/s diagnosis periapical granuloma 20 87.0 0 0.0 2 8.7 1 4.3 23 100.0 periapical cyst 2 14.3 12 85.7 0 0.0 0 0.0 14 100.0 periapical abscess 0 0.0 1 4.2 23 95.8 0 0.0 24 100.0 mixed periapical cyst granuloma 1 33.3 0 0.0 0 0.0 2 66.7 3 100.0 percent agreement = 89% table 2: strength of association between us criteria and positive final diagnosis of pac total positive final diagnosis of periapical cyst n n % or p 95% ci of or u/s diagnosis of periapical cyst negative 50 1 2 ref positive 14 12 85.7 294.0 <0.001 (24.6 to 3518.2) hypoechoic texture on u/s negative 37 0 0 ref positive 27 13 48.1 69.8 <0.001 (8.4 to 578.8) avascular pattern negative 24 0 0 ref positive 40 13 32.5 24.1 0.003 (2.9 to 196.3) irregular lesion margin on u/s irregular 50 1 2 ref regular 14 12 85.7 294.0 <0.001 (24.6 to 3518.2) j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 64 table 3: strength of association between us criteria and positive final diagnosis of pag total positive final diagnosis of periapical granuloma n n % or p 95% ci of or u/s diagnosis of periapical granuloma negative 41 3 7.3 ref positive 23 20 87 84.4 <0.001 (15.6 to 457.4) hyperechoic texture on u/s negative 41 3 7.3 ref positive 23 20 87 84.4 <0.001 (15.6 to 457.4) vascular pattern negative 43 3 7 ref positive 21 20 95.2 266.7 <0.001 (26 to 2729.8) irregular lesion margin on u/s regular 14 2 14.3 ref irregular 50 21 42 4.3 0.072[ns] (0.9 to 21.5) table 4: strength of association between us criteria and positive final diagnosis of paa total positive final diagnosis of periapical abscess n n % or p 95% ci of or u/s diagnosis of periapical abscess negative 40 2 5 ref positive 24 23 95.8 437.0 <0.001 (37.5 to 5093.1) hypoechoic texture on u/s negative 37 13 35.1 ref positive 27 12 44.4 1.5 0.452[ns] (0.5 to 4.1) anechoic texture on u/s negative 53 14 26.4 ref positive 11 11 100 62.7 <0.001 (7.5 to 524.4) avascular pattern negative 24 0 0 ref positive 40 25 62.5 80.6 <0.001 (9.9 to 654.1) irregular lesion margin on u/s regular 14 0 0 ref irregular 50 25 50 29.0 0.002 (3.6 to 235.9) table 5: strength of association between us criteria and positive final diagnosis of mixed pal total positive final diagnosis of periapical cyst/granuloma n n % or p 95% ci of or u/s diagnosis of mixed periapical cyst/granuloma negative 61 1 1.6 ref positive 3 2 66.7 120.0 0.003 (5.4 to 2688.8) hypoechoic center / hyperechoic periphery texture on u/s negative 61 1 1.6 ref positive 3 2 66.7 120.0 0.003 (5.4 to 2688.8) avascular center / vascular periphery negative 61 1 1.6 ref positive 3 2 66.7 120.0 0.003 (5.4 to 2688.8) irregular lesion margin on u/s regular 14 0 0 ref irregular 50 3 6 2.1 0.511[ns] (0.2 to 20.6) j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 65 table 6: validity of us criteria for pac ppv at pretest probability = npv at pretest probability = 10% sensitivity specificity accuracy 50% 90% u/s diagnosis of periapicalcyst negative 923 96.1 953 95.9 99.5 99.1 positive hypoechoic texture on u/s negative 100 72.5 711 78.4 97.0 100.0 positive avascular pattern negative 100 47.1 57.8 65.4 94.4 100.0 positive irregular lesion margin on u/ s irregular 92.3 96.1 95.3 95.9 99.5 99.1 regular table 7: validity of us criteria for pag ppv at pretest probability= npv at pretest probability = 10% sensitivity specificity accuracy 50% 90% u/s diagnosis of periapical granuloma negative 87 92.7 90.6 92.3 99.1 98.5 positive hyperectoic texture on u/s negative 87 92.7 90.6 92.3 99.1 98.5 positive vascular pattern negative 87 97.6 93.8 97.3 99.7 98.5 positive lrregular lesion margin on u/s irregular 91.3 29.3 51.6 56 4 92.1 96.8 irregular table 8: validity of us criteria for paa ppv at pretest probability= npv at pretest probability = 10% sensitivity specificity accuracy 50% 90% u/s diagnosis of periapical abscess negative 92 97.4 95.3 97.3 99.7 99.1 positive hypoechoic texture on u/s negative 48 61.5 56.3 55.5 91.8 91.4 positive anechoic texture on u/s negative 44 100 78.1 100.0 100.0 94.1 positive avascular pattern negative 100 61.5 76.6 72.2 95.9 100.0 positive irregular lesion margin on u/s regular 100 35.9 60.9 60.9 93.4 100.0 irregular j bagh college dentistry vol. 25(special issue 1), june 2013 the value of ultrasound oral diagnosis 66 table 9: validity of us criteria for mixed pal ppv at pretest probability= npv at pretest probability= 10% sensitivity specificity accuracy 50% 90% u/s diagnosis of mixedpenapical cyst granuloma negative 66.7 9s.4 96.9 97.7 99.7 96.4 positive hypoechoic center hyperechoic periphery texture on u/s negative 667 98.4 96.9 97.7 99.7 96.4 positive avascular center vascular penphery negative 66.7 93.4 96.9 97.7 99.7 96.1 positive irregular lesion margin on u/s regular 100 23 26.6 56.5 92.1 100.0 irregular j bagh college dentistry vol. 29(3), september 2017 the effect of among pedodontics, orthodontics and preventive dentistry 75 the effect of enamel protective agent on shear and tensile bond strength of stainless steel brackets by using different adhesive agents (in vitro study) dhuha abdul-qader, b.d.s. (a) sami k. al-joubori, b.d.s., m.sc. (b) abstract background: decalcification of enamel surface adjacent to fixed orthodontic appliances, in the form of white spot lesions, is a wide spread and familiar well-known side effect of orthodontic treatment. the present study was carried out to evaluate the effect of enamel protective agent (clinpro white varnish) on shear and tensile bond strength of dentaurum orthodontic stainless steel brackets by using 3m unitek and ormco as orthodontic adhesive agents. materials and methods: sixty-four extracted human upper first premolar teeth were selected and randomly divided into two groups with 32 teeth each, representing the shear and tensile bond strength testing groups. then according to the type of bonding adhesive and the addition of clinpro before bonding (3m, clinpro + 3m, ormco, clinpro + ormco) each group was subdivided into four equal subgroups each with 8 teeth. after passing twenty-four hours of bonding procedure, where the samples were kept at 37˚c the brackets were debonded by using tinius-olsen universal testing machine to record the shear and tensile bond strength value. the difference in bond strength was analyzed by using anova test at p≤0.05. results: the use of clinpro with 3m unitek orthodontic bonding agent shows higher shear and tensile bond strength than clinpro with ormco orthodontic bonding agent. conclusions: using clinpro white varnish before bonding can be successfully used with 3m unitek orthodontic bonding agent. keywords: clinpro white varnish, bond strength, 3m and ormco orthodontic bonding agent. (j bagh coll dentistry 2017; 29(3):75-79) introduction the fixation of orthodontic brackets enhances plaque retention and when the oral hygiene of the patient is poor, this will favor the development of demineralization and initial caries around the brackets (1). as carbohydrates been taken daily, they are fermented by the bacteria that colonized in the plaque and lead to decrease the intraoral ph. the low ph results in dissociation of calcium and phosphate ions from the enamel in an attempt to reach chemical equilibrium in the oral cavity environment. thus, one possible inseparable problem during the whole course of orthodontic treatment is the enamel demineralization around brackets, representing the primary phase of caries formation (2). prevalence of these acquired surface lesions due to orthodontic treatment, white spot lesions (wsl) is relatively high, affecting more than 40% to 60% of the orthodontic patients. they can appear very quickly, as rapid as in a couple of weeks after fixation of the brackets (3, 4). brackets are bonded to the surface of teeth with orthodontic adhesive. bonding of orthodontic brackets to the tooth enamel has been an important issue since the introduction of direct bonding in orthodontics (5). (a)master student, department of orthodontics, college of dentistry, university of baghdad. (b)assistant professor, department of orthodontics, college of dentistry, university of baghdad. composite resins are one of the most frequently used adhesives in orthodontic bonding (6). although they provide sufficient bonding strength and are easy to handle, they adhere to the tooth enamel only by micro-retention, require dry field and amount of fluoride release have not been found to be sufficient for anti-caries effect (7). the efficacy of preventive measures against the appearance of this phenomenon has been questioned during the last two decades. preventive methods mainly target the remineralization process and the inhibition of present bacterial flora through the use of topical fluoride applications, use of adhesives with remineralization potential that contains amorphous calcium phosphate or fluoride, ozone applications, chlorhexidine mouth rinses, probiotics, xylitol, and sealants (8). the preventive measures that do not require patient compliance are considered more predictable since only 13% of the patients were notified to achieve excellent cooperation with the use of mouth rinses and tooth brushing (9).therefore, sealing the susceptible enamel prior to bracket placing in order to form a cariesprotective shield has been the focus of interest in previous studies that primarily intend to obviate patient compliance (10, 11). fluoride has been proven to be effective in reducing the development of wsls associated with fixed orthodontic treatment (12). clinpro, is a fluoridated varnish, has been introduced to the market and supposed to be most beneficial in a j bagh college dentistry vol. 29(3), september 2017 the effect of among pedodontics, orthodontics and preventive dentistry 76 neutral ph environment. sealants were suggested as protective enamel agents that do not require patient cooperation (11). materials and methods the sample after examination with magnifying lens (10x) and light transillumination (13), sixty-four freshly extracted human maxillary first premolars (extracted for orthodontic reason) were collected and stored in closed containers filled with distilled water with 0.1% concentration of thymol crystals (volume/weight) (14), to prevent dehydration and bacterial growth (15, 16). the teeth were divided into two groups: one for shear bond testing and the other group for tensile bond testing. then each group was subdivided equally into 4 subgroups according to the orthodontic adhesive agent and the use of clinpro (white varnish). shear bond group: a1: 3m bonding agent, a2: clinpro with 3m, b1: ormco bonding agent, b2: clinpro with ormco. tensile bond group: c1: 3m bonding agent, c2: clinpro with 3m, d1: ormco bonding agent, d2: clinpro with ormco. construction of the acrylic block by using dental surveyor, the teeth assigned for shear testing were mounted vertically on a glass slide, and the teeth assigned for tensile testing were mounted horizontally (17, 18). then the acrylic were poured to the level of the cementoenamel junction of each tooth (19) using two lshaped metal plate placed in opposite side to make the mold for the acrylic block. after setting, slight adjustment of the acrylic blocks was made by using a portable engine. after mounting, the specimens were coded and then stored in normal saline solution containing crystals of thymol to prevent dehydration and bacterial growth until bonding (20). bonding procedure the buccal surface of the teeth was polished using non-fluoridated pumice with a brush (one brush used for each subgroup for standardization attached to a low speed handpiece for 10 seconds (21), then each tooth was rinsed with water spray for 10 seconds, and dried with oil-free air for 10 seconds (19). the distance of 1cm was used as standardization to hold the air water syringe away from tooth surface (22). thirty-two teeth (sixteen for shearing test group and sixteen for tensile test group) were bonded directly without using the enamel protective agent (clinpro) (a1, b1, c1 and d1). subgroup a1 + subgroup c1 (control) the bonding agent was done according to manufacturer instructions and at room temperature (24˚ c) with bracket placement in the middle of the buccal surface of the tooth. for standardization of pressure on the bracket, a constant load was placed on the bracket for 10 seconds (23) (by fixing 200 gm load on the upper part of the vertical arm of the surveyor, and fixing a hard rubber polishing bur in the lower part of the vertical arm of the surveyor and put it in contact with the bonded bracket), to make sure that each bracket was seated under an equal force and to ensure a uniform thickness of the adhesive (24). any excess adhesive material around the bracket base was gently removed by using dental probe before it has been set without disturbing the seated bracket (25). then curing the bracket adhesive (according to manufacturer instructions), at a distance of 5 mm (26). the same procedure had been made with the samples of subgroups b1 and d1 using ormco orthodontic bonding agent. clinpro was used with subgroups a2, b2, c2 and d2 before etching the tooth surface according to manufacturer instructions of application. the samples, after application of clinpro, were immersed in artificial saliva at 37˚c for 24 hours (27).then the subgroup a2 and subgroup c2 was bonded with 3m bonding agent as we did with the subgroups a1 and c1.the subgroup b2 and subgroup d2 was bonded with ormco bonding agent as it has been done with the subgroups b1 and d1. after completion of the bonding procedure, the specimens were immersed in distilled water and stored in the incubator at 37˚c for 24 hours prior to bracket debonding (28). shear bond strength test the shear bond strength test was accomplished using a tinius-olsen universal testing machine with a 5 kn load cell, a custom made chisel rod and a cross head speed of 0.5mm/minute (29), and the maximum load necessary to de-bond the bracket was registered (30). tensile bond strength test tensile testing was accomplished using the same universal testing machine by using long orthodontic archwires to pull the bracket in a vertical direction (18). j bagh college dentistry vol. 29(3), september 2017 the effect of among pedodontics, orthodontics and preventive dentistry 77 the readings were in megapascal (mpa) by dividing the force values by the bracket basal area (each 1 mpa equals1 n/mm²) (31). statistical analyses data were analyzed using spss (statistical package of social science) software version 19 by using the following statistics: a. descriptive statistics: including mean, standard deviation, minimum, maximum, statistical tables. b. inferential statistics: including; 1. shapiro-wilk test: to test the normality of distribution of the data. 2. one way analysis of variance (anova): to test any statistically significant difference among the tested groups. 3. tukey’s honestly significant difference test: to test any statistically significant differences between each 2 groups when anova showed a statistical significant difference. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results testing the normality of data distribution was carried out by using shapiro-wilk test, and the results showed that the data was normally distributed within the shear and tensile subgroups (p>0.05). the descriptive statistics of the shear bond strength subgroups were shown in table (1). it was clearly that subgroup a1 (samples with 3m unitek bonding agent) showed the highest shear bond strength value; while subgroup b2 (samples with clinpro with ormco bonding agent) demonstrated the least shear bond strength value among the shear bond subgroups. anova exhibited there was statistically highly significant difference among the mean values of the shear bond subgroups (p≤0.01). table 1: descriptive statistics of the shear bond strength (mpa) subgroups. g r o u p s descriptive statistics comparison (d.f.=31) mean s.d. min. max. f test pvalue a1 14.90 1.93 12.29 17.81 47.345 0.000 (hs) a2 6.16 1.89 4.08 8.96 b1 12.02 2.51 9.59 15.38 b2 4.61 1.51 3.04 7.77 testing the mean differences by using tukey honestly significant difference test showed that there was a high significant difference between the subgroups a1 and a2, b1 and b2, and a significant difference between a1 and b1. nevertheless, the difference between the subgroups a2 and b2 was not significant; as shown in table (2). table 2: tukey hds test of the shear bond strength subgroups. groups mean difference p-value a1 a2 8.74 0.000 (hs) b1 2.88 0.035 (s) a2 b2 1.55 0.417 (ns) b1 b2 7.42 0.000 (hs) the descriptive statistics of the tensile bond strength subgroups were shown in table (3). it was clearly obvious that the subgroup c1 (samples with 3m unitek bonding agent) had shown the highest tensile bond strength value; while subgroup d2 (samples with clinpro and ormco bonding agent) presented the least tensile strength value. anova showed that statistically there was a highly significant difference among the mean values of the tensile bond subgroups (p≤0.01). table 3: descriptive statistics of the tensile bond strength (mpa) subgroups g r o u p s descriptive statistics comparison (d.f.=31) mean s.d. min. max. f test pvalue c1 5.11 1.36 3.18 7.19 18.391 0.000 (hs) c2 4.54 1.51 3.08 7.42 d1 2.42 1.58 0.51 4.77 d2 0.87 0.19 0.65 1.15 testing the mean differences between the tensile subgroups by using tukey hds test revealed statistically that there were non significant differences between the subgroups c1 and c2, d1 and d2; whereas there were high significant differences between the subgroups c1 and d1, c2 and d2 as shown in the table (4). table 4: tukey hds test of the tensile subgroups. groups mean difference p-value c1 c2 0.57 0.816 (ns) d1 2.69 0.001 (hs) c2 d2 3.67 0.000 (hs) d1 d2 1.55 0.099 (ns) j bagh college dentistry vol. 29(3), september 2017 the effect of among pedodontics, orthodontics and preventive dentistry 78 disscusion in this study, the mean sbs of the two orthodontic adhesives; 3m unitek (14.90 mpa) and ormco (12.02 mpa) bonding agents was higher than the clinically adequate sbs (5.9 to 7.8 mpa) as proposed by reynolds (32), which means that both of the adhesives can resist shear stress to adequate level. in addition to that, 3m unitek orthodontic bonding adhesive gave a greater value in shear test than ormco orthodontic bonding adhesive, and this could be attributed to the composition of the adhesive including the type, shape, size, and amount of inorganic fillers, and the type of coupling agent present in the adhesive itself (33). while, after the pretreatment with the enamel protective agent (clinpro), the mean sbs of the 3m unitek bonding agent (6.16 mpa) was higher than the mean sbs of the ormco (4.61 mpa) bonding agent, although both of them were higher than the required minimum sbs for direct bonding (3 mpa) suggested by lopez (34). the mean sbs of the ormco bonding agent with the pretreatment with clinpro (4.61 mpa) was lower than that of the control subgroup, and this could be attributed to the resistance effect that the outer enamel layer acquires from the fluoride content of the clinpro which may be of significant effect (35). the result of the present study showed that the mean tensile bond strength of the 3m unitek bonding agent (5.11 mpa) was higher than the mean tensile bond strength of the ormco bonding agent (2.42 mpa). the findings of the present study showed with the pretreatment of the samples with the enamel protective agent (clinpro), the mean tensile bond strength of the 3m unitek bonding agent (4.54 mpa) was higher than the mean tensile bond strength of the ormco bonding agent (0.87 mpa) and this might be due to the more flowable acid etch of the ormco orthodontic bonding agent that might have a less penetrating effect than the gel acid etch of the 3m unitek orthodontic bonding agent, 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demineralize enamel after different pretreatment methods. angle orthod 2012; 82: 56–61. 32. reynolds ir. a review of direct orthodontic bonding. br j orthd 1975; 2: 171-8. 33. evans lb, powers jm. factors affecting in vitro bond strength of no-mix orthodontic cements. am j orthod 1985; 87: 508-12. 34. lopez ji. retentive shear strength of various bonding attachment bases. am j orthod 1980; 77(6): 669-78. 35. montasser ma, taha m. effect of enamel protective agents on shear bond strength of orthodontic brackets. progress in orthod 2014; 15(1): 34. 36. itota t, torii y, nakabo s, yoshiyama m. effect of fluoride application on tensile bond strength of selfetching adhesive systems to demineralized dentin j prosthetic dentistry 2002; 88(5): 503-10. مة للصدأتأثير المادة الواقية لمينا السن على قوى القص والشد باختالف مواد لصق الحاصرات المعدنية المقاو )دراسة مختبرية( الخالصة تصاحب التي زوال كلس المينا لسطوح االسنان المجاورة ألجهزة تقويم األسنان الثابتة، في شكل بقع بيضاء، من االثار الجانبية المعروفة والمألوفة ( على قوة القص والشد لحاصرات التقويم المعدنية clinproعالج االسنان باستخدام التقويم. لقد أجريت هذه الدراسة لتقييم تأثير عامل وقائي المينا ) . ormco)و ) (3m)باستخدام مواد لصق حاصرات التقويم لكل منهما، تمثل مجموعات سن 23ية وقسمت عشوائيا إلى مجموعتين ن البشراختيار أربعة وستين سن من الضواحك العلوية األولى من االسناتم + clinpro( )3m ،clinpro + 3m ،ormco ،clinproاختبار قوة القص وقوة الشد, ثم وفقا لنوع المادة الالصقة وإضافة عامل واقي المينا ) ormcoرين ساعة من إجراء الربط، حيث تم أربع وعش أسنان. بعد مرور 8وية لكل منها ( تم تقسيم كل مجموعة إلى أربع مجموعات فرعية متسا ( لقياس قيمة قوة القص والشد للحاصرات المعدنية. (tinius-olsenاختبار فك االرتباط باستخدام الة الفحص العالمية تم c°37العينات في حفظ .(p≤0.05)ل (anova)تم تحليل الفرق في القوى باستخدام اختبار كمادة رابطة لحاصرات التقويم يظهر أعلى قوة قص وقوة شد للحاصرات المعدنية، 3m unitek)كشفت الحقائق من هذه الدراسة أن استخدام ) أدنى قوة قص وقوة شد لحاصرات التقويم المعدنية. ormco)مع مادة لصق الحاصرات ) clinpro)بينما يظهراستخدام واقي المينا ) كمادة لصق 3m unitek)قبل مادة لصق حاصرات التقويم المعدنية, يمكن أن تستخدم بنجاح مع ) clinpro)تخدام واقي المينا )الخالصة: باس حاصرات تقويم األسنان. ryaheen.doc j bagh college dentistry vol. 27(2), june 2015 effect of gender, age oral diagnosis 79 effect of gender, age and tooth loss on the dimensions of incisive canal, and buccal bone anterior to the canal (computed tomography study) ryaheen ghazi rashid, b.d.s. (1) ahlam ahmed fatah, b.d.s., m.sc. (2) abstract background: the incisive canal is an anatomical structure with an important location in the anterior maxilla, analyzing this canal and its relation to the bone anterior to the canal is necessary during dental implant. aim of this study is evaluated effect of gender, age and tooth loss in area of maxillary central incisors teeth on the dimensions of incisive canal and buccal bone anterior to the canal using spiral computed tomography. materials and methods: sample consists of prospective study for 156 subjects for both gender, they divided into two groups, 120 dentate group (60 male and 60 female) with age ranging from (20-70) and 36 edentate group (with missing maxillary central incisors) (18 male and 18 female) with age ranging from (50-70). all subjects attended to baquba teaching general hospital in diyala for computed tomography scan investigation for different diagnostic purposes. the following were measured and recorded from sagittal section of ct for analysis 1-diameter and length of incisive canal.2distance and length of buccal bone anterior to canal. result: gender had effect on the dimensions of incisive canal and buccal bones anterior to this canal, the mean values begin higher in male as compared to female. dental status had effect on incisive canal length and buccal bone dimensions, mean values is higher in dentate than in edentate group, canal diameter remain unchanged with dental status. age had no effect on all selected measurements in study sample. duration of maxillary central incisors teeth loss had effect on canal length and buccal bone dimensions mean values begin lower in long duration than that in short duration while it had weak effect on incisive canal diameter. conclusion: gender and dental status are important factors that can affect incisive canal and amount of bone anterior to canal. keywords: incisive canal; buccal bone; computed tomography. (j bagh coll dentistry 2015; 27(2):79-85). introduction anterior segments of the jaws in maxillary and mandibular locations are often considered as safer areas when compared with posterior jaws during surgeries (1,2). incisive canal (ic), located at the midline, posterior to the central incisor teeth, is an important anatomic structure of the anterior maxillary area (3). the canal commences towards the front of the floor of each nasal cavity. it opens into median plane of the palatine process of the maxilla, posterior to the central incisors and transmits naso-palatine vessels and nerves, branches of the maxillary division of the trigeminal nerve and the maxillary artery (4). it is important to know the anatomic features in this area when performing surgeries (e.g., implant, bone augmentation and apicoectomy) (3). according to the presence or absence of teeth in the anterior maxilla, dimensional changes of anterior jaw bones and incisive canal were reported (5,6).the gender influenced on buccal bone dimensions and incisive canal (7),men had higher level than women (6),women have less dense bone than men and over the years an equal loss of bone usually leaves women with a lesser bone mass (8). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. dental esthetics has become an important issue in implant dentistry in the anterior maxilla, patients consider the esthetic outcome to be an essential factor, often surpassing even functional aspects of the dental implant therapy (9). among all the teeth, the upper incisors demand the greatest attention in implant treatment, from both an esthetic and functional viewpoint. two anatomical limitations exist in the anterior maxilla. one is the absorption of the alveolar bone following loss of the incisors, and the other is the location of the incisive canal at the palatal zone of the incisor region (10).the computed tomography (ct) scan is an imaging method that uses x-rays to create cross-sectional pictures of the body. a computer crates separate image of body area, called slices, were can be stored, viewed on monitor or printed on film. (11). innovations in imaging systems and increased usage of preoperative ct evaluation have allowed us to get a more accurate and close look at the incisive canal and surrounding bone (12).in the present study spiral computed tomography used for determination the effect of gender, age and central incisors loss on incisive canal and buccal bone anterior to canal. j bagh college dentistry vol. 27(2), june 2015 effect of gender, age oral diagnosis 80 materials and methods the sample composed of 156 patients, age ranged between (20-70) years old, the total sample included patients attended to the baquba teaching general hospital in diyala for ct scan investigations for different diagnostic purposes. those subjects were divided into 2 groups: 1-dentate group: included 120 dentate subject (60 male and 60 female) with age ranging from (2070). 2-edentate group: included 36 subjects (18 male and 18 female) with age ranging from (50-70), all the edentate group with missing both maxillary central incisors. edentate group divided into two group according to the duration of maxillary central incisor teeth loss, long duration (5+) years which consists 26 subjects and short duration (<5 years) which consists of 10 subjects. the ct machine used in the present study was (toshiba, aquillion 64) with a helical scan to acquire the image. the image were generated at 120kv and 500 ma x-ray, the slice thickness of the image was 0.5mm,the image matrix size was 512× 512,window level(wl) =35,window width(ww) =85,exposure time =2.5 sec. and imaging zoom =1.00. the following measurements were taken on sagittal section of ct according to protocol (3). athe diameter of (ic) were measured, the following points were selected for standardized measurement as shown in figure 1 1. the diameter of crestal part of ic (at incisive foramen). 2. the diameter of middle part of ic (at the middle length of the ic). 3. the diameter at the most apical part of ic. 4. the mean of the total ic dimensions. bthe length of ic which was measured from nasal fossa to the incisive foramen (palatal border of incisive foramen). figure 1 cthe distance of the buccal bone anterior to the ic including the following points for standardized measurements as shown in figure 2 1. the distance of the crestal part of the buccal bone (at alveolar crest) 2. the distance of middle part of the buccal bone (from the buccal wall of the ic to the facial aspect of the bone wall using a horizontal line from the palatal border of the incisive foramen). 3. the distance of the most apical part of the buccal bone (from the buccal wall of the ic to the facial aspect of the buccal bone wall (ans) using a horizontal line from the palatal border of the nasal foramen). 4. the mean of the total buccal bone distances. dthe length of the buccal bone anterior to the ic (from the apical measurement of the buccal bone to the alveolar crest).figure 2 statistical analysis statistical analyses were done using spss version 21 computer software (statistical package for social sciences). quantitative variables are described by mean, sd. the statistical significance, strength and direction of linear correlation between 2 quantitative normally distributed variables were assessed by pearson’s linear correlation coefficient. cohen’s d is a standardized measure of effect size for difference between 2 means, which can be compared across different variables and studies, since it has no unit of measurement. a multiple linear regression model was used to study the net and independent effect of a set of explanatory variable (gender, age and duration of edentulous central incisor) on a quantitative outcome (dependent) variable. figure 1: sagittal section on ct showing measurements of incisive canal diameter and figure 2: sagittal section on ct showing measurements of buccal bone distances and length j bagh college dentistry vol. 27(2), june 2015 effect of gender, age oral diagnosis 81 results incisive canal dimensions (length and diameter) for dentate subjects differed according to gender. mean values showed that male had longer and wider canals in dentate subjects ,for testing the effect of gender on these measurements by cohen's d , the effect seem to be moderately strong (0.46, 0.55). buccal bone dimensions (length and distance of bone anterior to the canal) were different between genders, where male had greater mean values than female, for testing the effect of gender on these measurements by cohen's d, the effect seem to be moderately strong (0.37, 0.42) (table 1). edentate group shows similar results. length, diameter of the canal and length, distance of buccal bone anterior to the canal were greater in mean value for male subjects compared with female subjects, for testing the effect of gender on these parameters by cohen's d, the effect seem to be moderately strong for both gender (0.44, 0.57, 0.61, 0.77) (table 2). absence of maxillary central incisors cause a decrease at incisive canal length and buccal bone dimensions(length and distance) for both genders, for testing the effect of tooth loss on these parameters by cohen's d, the effect seem to be strong for male (-0.89, -1.17, -1.4) and for female (-1.37, -1.44,-1.62) while canal diameter was not change according to dental status and there was no effect of tooth loss on this parameter for both gender (cohen's d=0) (table3). mean value of canal length and buccal bone dimensions(length and distance)begin higher in short duration (<5years) as compared to long duration (5+) years for both genders, for testing the effect of the duration of maxillary central incisors teeth loss on these parameters by cohen's d, the effect seem to be moderately strong to strong for male (-0.8,-0.43, -0.92)and strong for female (-1.14, -1.13, -1.22)while canal diameter show weak effect with duration for both male (0.18) and female (-0.17) (table 12). age shows very weak indirect relationship and non significant correlation with all selected measurements in current study. in the linear regression model, gender shows a statistically significant difference on all selected measurements in the study sample after adjusting for age and duration of maxillary central incisors teeth loss, age shows a non statistically significant difference on all selected measurements after adjusting for gender and duration of maxillary central incisors teeth loss, duration of maxillary central incisors teeth loss shows a statistically significant difference on canal length and buccal bone dimensions while it shows a no statistically significant difference on mean canal diameter after adjusting for age and gender (tables 4-11). table 1: effect of the gender on the ic and buccal bone dimensions for dentate group variables gender mean sd cohen's d canal diameter (crestal) male 3.1 0.6 0.62 female 2.7 0.7 (middle) male 1.5 0.6 0.55 female 1.2 0.5 (apical) male 2.1 0.7 0.31 female 1.9 0.6 mean male 2.2 0.6 0.55 female 1.9 0.5 canal length male 10.9 2.3 0.46 female 9.8 2.5 buccal bone distance (crestal) male 6.2 0.8 0.55 female 5.7 1 (middle) male 7.4 1.1 0.61 female 6.7 1.2 (apical) male 11.2 1.7 0.44 female 10.6 1 mean male 8.2 1.3 0.42 female 7.7 1.1 buccal bone length male 20 2 0.37 female 19.1 2.8 j bagh college dentistry vol. 27(2), june 2015 effect of gender, age oral diagnosis 82 table 2: gender difference for ic and buccal bone dimensions in edentate group table 3: effect of the teeth loss on the ic and buccal bone dimensions compared to dentate group variables study group mean sd cohen's d study group mean sd cohen'sd canal diameter (crestal) dentate 2.7 0.7 -0.14 dentate 3.1 0.4 -0.2 edentate 2.6 0.7 edentate 3 0.5 (middle) dentate 1.2 0.5 0 dentate 1.4 0.7 0 edentate 1.2 0.6 edentate 1.4 0.5 (apical) dentate 1.7 0.6 0 dentate 2 0.8 -0.14 edentate 1.7 0.6 edentate 1.9 0.6 mean dentate 1.9 0.5 0 dentate 2.1 0.6 0 edentate 1.9 0.6 edentate 2.1 0.4 canal length dentate 10.5 2 -1.37 dentate 11 2.1 -0.89 case s 8.5 0.9 edentate 9.2 1.9 buccal bone distance (crestal) dentate 5.5 1.1 -2.36 dentate 6.1 0.7 -2.17 edentate 3 1 edentate 3.8 1.4 (middle) dentate 6.5 1.3 -1.35 dentate 7.3 1 -1.45 edentate 4.8 1.2 edentate 5.5 1.5 (apical) dentate 10.7 2.4 -0.97 dentate 11.4 3 -0.56 edentate 8.4 2.3 edentate 10 1.5 mean dentate 7.6 1.4 -1.62 dentate 8.3 1.4 -1.4 edentate 5.4 1.3 edentate 6.4 1.3 buccal bone length dentate 18.5 3 -1.44 dentate 19.5 3 -1.17 edentate 15.4 1.3 edentate 16.5 2.1 variables gender mean sd cohen's d canal diameter (crestal) male 3 0.4 1 female 2.6 0.4 (middle) male 1.4 0.5 0.36 female 1.2 0.6 (apical) male 1.9 0.6 0.33 female 1.7 0.6 mean male 2.1 0.3 0.57 female 1.9 0.4 canal length male 9.2 1.9 0.44 female 8.5 1.2 buccal bone distance (crestal) male 3.8 1.4 0.66 female 3 1 (middle) male 5.5 1.5 0.51 female 4.8 1.2 (apical) male 10 1.5 0.82 female 8.4 2.3 mean male 6.4 1.3 0.77 female 5.4 1.3 buccal bone length male 16.5 1.1 0.61 female 15.4 2.3 j bagh college dentistry vol. 27(2), june 2015 effect of gender, age oral diagnosis 83 table 4: multiple linear regression model with canal diameter-mean as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among dentate group. partial regression coefficient p (constant) 2.136 <0.001 age (years) -0.005 0.18[ns] gender 0.278 0.005 r²=0.18, p (model) = 0.007 table 5: multiple linear regression model with canal diameter-mean as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among edentate group. partial regression coefficient p constant 2.727 0.037 age (years) -0.012 0.52[ns] gender 0.334 0.04 duration of edentulous (5+ years) -0.092 0.64[ns] r²=0.115, p (model) = 0.027 table 6: multiple linear regression model with buccal bone diameter-mean as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among dentate group. partial regression coefficient p (constant) 7.636 <0.001 age (years) 0.001 0.92[ns] gender 0.577 0.011 r²=0.255,p (model) = 0.037 table 7: multiple linear regression model with buccal bone diameter-mean as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among edentate group. partial regression coefficient p constant 9.831 <0.001 age (years) -0.053 0.2[ns] gender 1.055 0.008 duration of edentulous (5+ years) -1.446 0.001 r²=0.402, p (model) = 0.001 table 8: multiple linear regression model with canal length as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among dentate group. partial regression coefficient p (constant) 9.508 <0.001 age (years) 0.006 0.68[ns] gender 1.068 0.016 r²=0.25, p (model) = 0.049 table 9: multiple linear regression model with canal length as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among edentate group. partial regression coefficient p constant 12.778 0.002 age (years) -0.062 0.29[ns] gender 0.660 0.02 duration of edentulous (5+ years) -0.397 0.04 r²=0.386, p (model) = 0.03 table 10: multiple linear regression model with buccal bone length as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among dentate group. partial regression coefficient p (constant) 19.935 <0.001 age (years) -0.019 0.23[ns] gender 0.875 0.03 r²=0.244, p (model) = 0.04 j bagh college dentistry vol. 27(2), june 2015 effect of gender, age oral diagnosis 84 table 11: multiple linear regression model with buccal bone length as the dependent (response) variable and age, gender in addition to duration as the explanatory (independent) variables among edentate group. partial regression coefficient p (constant) 18.844 <0.001 age (years) -0.037 0.55[ns] gender 1.106 0.02 duration of edentulous (5+ years) -1.573 0.018 r²=0.243, p (model) = 0.029 table 12: effect of the duration of the teeth loss on ic and buccal bone dimensions in edentate group. measure-ments duration of teeth loss mean sd cohen'sd duration of teeth loss mean sd cohen's d canal diameter (crestal) long 2.3 0.6 -0.14 long 2.9 0.8 -0.11 short 2.4 0.8 short 3 0.9 (middle) long 1.2 0.6 -0.17 long 1.5 1.1 -0.18 short 1.3 0.5 short 1.7 1.1 (apical) long 1.7 0.7 -0.15 long 2.3 0.9 -0.11 short 1.8 0.6 short 2.4 0.9 mean long 1.7 0.6 -0.17 long 2.2 1.1 -0.18 short 1.8 0.6 short 2.4 1.1 canal length long 8.2 1.1 -1.14 long 8.8 1.1 -0.8 short 9.4 0.9 short 9.9 1.6 buccal bone distance (crestal) long 2.6 0.5 -1.89 long 3.4 1.1 -1.07 short 4 1.2 short 4.8 1.8 (middle) long 4.4 0.8 -1.32 long 5.1 1.4 -0.96 short 5.8 1.6 short 6.4 1.3 (apical) long 8 1.3 -1.07 long 9.6 1.1 -0.92 short 9.4 1.3 short 10.9 2.1 mean long 5 1.1 -1.22 long 6 1.1 -0.92 short 6.4 1.3 short 7.3 1.7 buccal bone length long 13.6 2.6 -1.13 long 16.3 1.1 -0.43 short 16.1 1.8 short 16.8 1.3 discussion the present study showed gender and loss of maxillary central incisors influenced the incisive canal and buccal bone dimensions anterior to this canal. when dentate subjects were classified according to gender, male had greater canal and buccal bone dimensions. edentate subjects (with missing maxillary central incisors) showed the same results when gender was considered. our result agreed with the study made by liang et al (6) who examined incisive canal length and diameter on 120 ct scans and found higher values in male. bornstein et al (7) examined 44 male and 56 female, they measured canal dimensions and buccal bone width and reported statistically higher buccal bone width and canal length values in male and this seem to be closes to our result. guncu et al (3) and tozum et al (13) examined 417 males and 516 females, they reported that the gender had significant influence on canal and buccal bone dimensions for both dentate and edentulous patients. the effect of tooth loss on the canal and buccal bone dimensions in male and female were examined. when central incisors were not present, both incisive canal length and buccal bone dimensions decreased; however, canal diameter did not change with dental status in both genders. our study come in agreement with the study made by liang et al (6),they reported longer canals in dentate patients with no statistical difference noted for the canal diameter. song et al (14) examined canal length in 56 maxilla and found that the canal length decrease in edentulous subjects and this correlate with the present study. our result are in agreement with j bagh college dentistry vol. 27(2), june 2015 effect of gender, age oral diagnosis 85 the study made by guncu et al (3) and tozum et al (13),they reported that the canal length and buccal bone dimensions decrease in edentulous patients while canal diameter did not change. conversely to the present study results, mardinger et al (5) examined canal dimensions on 207 ct scans and reported that the canal diameter enlarged with tooth loss and this could be attributed to different in canal morphology. in the present study, no significant correlation are detected between age and canal, buccal bone dimensions, such result correlate with the study made by guncu et al (3); mraiwa et al (4); tozum et al (13) . in contrast to these finding bornstein et al (7) reported that the age had significant influence on canal length which decrease with age, liang et al (6) found that the canal enlarged by age and this disagreement with our study. duration of maxillary central incisors teeth loss had significant difference on canal length and buccal bone dimensions with mean values begin higher in short duration as compared to long duration for both genders. these finding come accordance with the study made by bornstein et al (7) who reported that the buccal bone width decreasing in values for patients with missing central incisors and long time span since tooth loss. references 1. artiz z, nemcovsky ce, bitlitum i, segal p. displacement of the incisive foramen in conjunction with implant placement in the anterior maxilla without jeopardizing vitality of nasopalatine nerve and vessels: a novel surgical approach. clinical oral implants 2000; 11: 505-10. 2. jacobs r, lambriches i, liange x, martens w, mraiwa n, adriaensens p, gelan, j. neurovascularization of the anterior jaw bones revisited using high-resolution magnetic resonance imaging. j oral surgery, oral medicine, oral pathology, oral radiology endodontics 2007; 103: 688-93. 3. 3-guncu gn, yildrim yd, yilmaz hg, galindomoreno p, velasco-torres m, al-hazaimi k, alshawaf r, karabulut e, wang h-l, tozum tf. is there a gender difference in anatomical feature of incisive canal and maxillary environmental bone? clinical oral implants 2013; 24:1023-6. 4. 4-mraiwa n, jacobs r, van cleynenbreugel j. the nasopalatine canal revisited using 2d and 3d ct imaging. dentomaxillofac radiol 2004; 33: 396-402. 5. mardinger o, namani-sadan n, chaushu g, schwartz-arad d. morphologic change of the nasopalatine canal related to dental implantation: a radiologic study in different degree of absorbed maxillae. j periodontal 2008; 79: 1659-62. 6. liang x, jacobs r, martens w, yuqian hu, adriaensens p, quirynen m, lambrichts i. macro-and micro anatomical, histological and computed tomography scan characterization of the nasopalatine canal. j clinic periodontal 2009; 36: 598-603. 7. bornstein mm, balsiger r, sendi p, von arx t. morphology of the nasopalatine canal and dental implant surgery: aradiographic analysis of 100 consecutive using limited cone-beam computed tomography. clinical oral implant 2010; 22: 295-301. 8. laflamme g, jowsey j. bone and soft tissue change with oral phosphate supplements. j clin invest 1972; 51: 2834-40. 9. teughels w, merheb j, quirynen m. clinical horizontal dimensions of interproximal and buccal bone around implants for optimal esthetic outcomes: a systematic review. clinical oral implants2009; 20:134-45. 10. asaumi r, kawai t,sato i, yoshida s, youse t. three-dimensional observations of the incisive canal and surrounding bone using cone-beam computed tomography. oral radiol 2010; 26: 20-8. 11. terrier f, grossholz m, becker cd. spiral ct of the abdomen. berlin: spriger; 2002 12. faitaroni la, bueno mr, carvalhosa a, mendonca ef, estrela c. differential diagnosis of apical periodontitis and nasopalatine duct cyst. j endod 2011; 37:403-410. 13. tozum tf, guncu gn, yildirim yd, yilmaz hg, galindo-moreno p, velasco-torres m, al-hezaimi k, al-sadhan r, karabulut e ,wang hl. evaluation of incisive canal characteristics related to dental implant treatment with computerized tomography: a clinical multicenter study. j periodontol 2012; 83: 337-43. 14. song wc,jo dl ,lee j. microanatomy of the incisive canal using three-dimentional reconstruction of micro ct images: an ex vivo study. oral surg oral med oral pathol oral radiol endod 2009; 108: 583-90. haween.docx j bagh college dentistry vol. 28(1), march 2016 interleukin6 level oral and maxillofacial surgery and periodontics 103 interleukine-6 level in saliva of patients with chronic periodontitis: a case-control study haween t. nanakaly, b.sc., m.sc., ph.d. (1) abstract background:periodontal diseases are infectious diseases in which periodontalpathogens trigger chronic inflammatory and immune responses. interleukine-6 is a multifunctional cytokine playing a central role in inflammation and tissue injury.the aim of the study is to determine the level of interleukin-6(il-6) in saliva of patients with chronic periodontitis compared to healthy subjects. materials and methods:the total subjects of the present study is 60, divided into 3 groups; 20 patients with chronic periodontitis with pocket depth(pd ≥4 mm)(group i), 20 patients with pocket depth(pd <4 mm) with clinical attachment loss (group ii), and 20 healthy controls with pocket probing depth (ppd ≤ 3 mm) without clinical attachment loss (group iii). un-stimulated salivary sample was taken from each subject and was investigated for the presence of interleukine-6by using enzyme‑linked immunosorbent assay (elisa) technology. results:mean il-6 levels in saliva in patients with chronic periodontitis (98.40 ± 18.44 ng/l)was significantly higher than in controls (11.67 ± 3.32; p=0.001). also a significant difference in il-6 levels in saliva was observed between the ppd ≥ 4 mm and ppd < 4 mm groups and between ppd ≥ 4 mm and control groups, as well as statistically significant differences were observed between ppd < 4 mm and control groups (p < 0.001). conclusion:the interleukine-6 level in saliva can be considered as one of inflammatory biomarker indicators of severity of periodontitis. keywords:chronic periodontitis, saliva, interleukine-6. (j bagh coll dentistry 2016; 28(1):103-108). introduction saliva is one of the most important body fluids, which contains a large number of proteins and peptides that are easily accessible and may serve as a potential source to measure biomarkers released during disease initiation and progression, it has significant association with inflammatory, connective tissue destruction and bone remodeling phases of periodontal disease. subsequently, saliva has been used in the diagnosis of periodontal disease and monitor response to treatment(1,2). periodontitis is an inflammatory disorder affecting supporting tissues of the teeth, primarily initiated by a small group of gram-negative anaerobic bacteria within periodontal pockets. the stimulation of host defense system against bacterial pathogens result in connective tissue breakdown and alveolar bone destruction (3). during periodontitis, inflammatory cytokines (il1β, il-6, and tnf-α) and reactive oxygen species (ros) are released from immune cells to fight the periodontal pathogens; the activation of these proinflammatory molecules leads to tissue destruction as a result of complex interactions between the pathogenic bacteria and the host’s immune response. role of host immune response is furthermost important factor in periodontitis as it determines both disease progression and severity ( 4). (1)lecturer. department of basic sciences, college of dentistry, hawler medical university. cytokines are water-soluble glycoproteins, secretedby hematopoietic and nonhematopoieticcells in response to infection. their primary function is intercellular signalling(5),which are central to the pathogenesis of an ever-increasing number of diseases, including periodontal disease(6).cytokines play a key role in a number of biological activities including, development, proliferation, regeneration, repair and inflammation (7). an inflammatory cytokine may be described as a cytokine which is induced during an inflammatory response and is related with the onset and/or progression of the insult. so far, interleukin (il)-l alpha (α) il-1beta (β) il-6, il-8, and tumour necrosis factor (tnf)alpha (α) have been categorized as inflammatory cytokines(8,9). contributing inflammatory mediators and tissue destructive molecules have been detected in the gingival tissues, gingival crevicular fluid (gcf) and saliva of patients affected by periodontitis. qualitative and quantitative changes in the composition of these biomarkers could have diagnostic and therapeutic significance (10,11). interleukin-6 (il-6), is a pleiotropic cytokine that acts as both a pro-inflammatory and antiinflammatory activity.it exerts anti-inflammatory properties through enhancement of tissue inhibitor of metalloproteinase (timp) production and suppression of pro-inflammatory cytokines il-1β and tnf-α. in addition, down-regulation of proinflammatory cytokines and up-regulation of antiinflammatory molecules (e.g. il-1 receptor antagonist, tnf soluble receptor) in acute inflammatory processes (12,13). it has a profound j bagh college dentistry vol. 28(1), march 2016 interleukin6 level oral and maxillofacial surgery and periodontics 104 effect on b cells, promoting plasma cell differentiation and immunoglobulin (ig) secretion, also enhances t cell proliferation(14).recent evidence has suggested that il-6 may play important roles in the development of specific immune response, as described mice lacking il-6 or tnf-α gene expression are deficient in t and b cell function(15) il-6 is known as one of the key cytokines of host response to inflammation and tissue injury such as that seen in chronic periodontitis (16) and induces bone resorption by itself and in conjunction with other bone-resorbing agents.there is a significant correlation between tissue levels of il-6 and the severity of the coincident inflammation.elevated levels of il-1β and il-6 have been shown to be induced by periodontal pathogens and are correlated with the continuous tissue destruction observed in periodontitis (17,18). furthermore, sspontaneous production of il-6 has been reported in mononuclear cells isolated from inflamed gingival tissues of patients with periodontitis.on the one hand, il-6 levels may correlate with the severity of periodontal disease. in addition, higher il-6 levels have been observed in sites ofrefractory periodontitis compared to sites of stable, advanced periodontitis, which suggests that it could be a diagnostic marker for sites of active periodontal disease (19). the hypothesis was to testthe relationship between salivary il-6 levels and clinical findings in patients with chronic periodontitis and individuals with healthy periodontium and to assess usefulness of il-6 for diagnosis of periodontal severity. the present study has the following objectives: 1. to assess il-6 levels in the saliva in patients with chronic periodontitis in comparison to individuals with healthy periodontium. 2. tocompare the salivarylevel of il-6 with the severity of the periodontal disease. materials and methods study groups a total of 60 subjects (32 females and 28 males; mean age of 37.40 ±3.84 years) were included in the present study who attended the department periodontal surgery, college of dentistry, hawler medical university in erbil during the period of 15th november 2014 to 5th february 2015. out of the 60 subjects, 40 were diagnosed with chronic periodontitis (experimental group)(20). within the experimental group two subgroups were formed according to periodontal pocket occurrence: one considered as group of subjects with more severity of periodontal disease pocket depth (pd≥ 4 mm) (20 patients) and the other subjects with less severity of disease (pd< 4 mm) with clinical attachment loss (20 patients). the control group was compromised of 20periodontally healthy individuals without clinical attachment loss, without pocket depth >3 mm and with bleeding index (bop<10%). all subject had more than 20 teeth and none of the subjects reported any coexisting systemic disease particularly systemic neurological disorder (e.g., epilepsy or schizophrenia), longterm pharmacological treatment, pregnant, lactating women, smoking and alcoholism, individuals treated with anti-inflammatory and antibiotics within the previous 3 months, were excluded from the study. informed consent was obtained from all the patients before participation in the study, which was approved by the ethical committee of college of dentistry/ hawler medical university. saliva sampling unstimulated whole saliva were collected from all participants in a given time between (9:00a.m. and 11:00 a.m.). the subjects (cases and controls) refrained from eating, drinking, and practicing oral hygiene habits (flossing, brushing, and mouth rinses) within at least 2 hours prior to saliva collection. subjects were asked to rinse their mouth with distilled water, following which they expectorated at least 3ml of un-stimulated whole salivainto a 5ml sterile tubes according to the method described by navazesh (21) all samples were immediatelycentrifuged at 3000 rpm for 20 minutes and clear supernatant was stored at-20ºc pending analysis. the il-6 levels in saliva samples were measured with a human interleukine-6 (il-6) elisa kit provided by mybiosource international inc., usa (catalog # mbs164590). the analytical sensitivity for the test was 1.03ng/l, and the detection range was between 2 ng/l→600 ng/l. statistical analysis statistical analysis was performed by using the spsspc/ windows version 21 software packages (spss inc., chicago, il, usa). paired t-test was used to compare il-6 concentrations in saliva between 2 given groups. one-way analysis of variance was used to determine the differences between the groups and the significance of mean difference between the groups was done by tukey’s multiple comparison test. all data were expressed as means±sd (a value of p<0.05 was considered significant). j bagh college dentistry vol. 28(1), march 2016 interleukin6 level oral and maxillofacial surgery and periodontics 105 results the mean concentrationof il-6 in saliva of patients with chronic periodontitis was (98.40 ± 18.44 ng/ml), whereas in the control group was (11.67 ± 3.32 ng/ml). the difference in the il-6 level was statistically highly significant (p< 0.01) (table 1). table 2 showed a comparison of mean concentration of the salivary il-6 of three groups. anova revealed highly significant difference inil-6 level among the groups (f= 990.80 p < 0.001). in tukey's multiple comparison test a highly significant differences were observed in il-6 concentration in saliva between ppd ≥ 4 mm and ppd < 4 mm groups(114.43 ± 9.74 vs. 82.36 ± 7.85, q=12.45 ; p < 0.001), as well as between ppd ≥ 4 mm and control groups ( p < 0.001).further, the mean concentration of il-6 level in saliva of ppd < 4 mm group was also found to be significantly different as compared to control group (82.36 ± 7.85 vs.11.67 ± 3.32, q=36.28; p < 0.001) (table 3). table 1: comparison of salivary il-6 level (ng/l) between chronic periodontitis patients and control groups(by t-test) groups tested number concentrations of il-6 (ng/l) (mean ±sd ) t-value p-value case (chronic periodontitis) 40 98.40 ± 18.44 33.75 p<0.001 ** control (healthy patients) 20 11.67 ± 3.32 15.75 il-6: interleukine-6; sd-standard deviation; ** paired sample ttest: p < 0.001, highly significant table 2: anova test for detection ofsalivary il-6 (ng/l) level in different study groups. study groups salivary il-6 level (ng/l) (mean ±sd ) f value p value anova group i: ppd ≥ 4 mm (n=20) 114.43 ± 9.74 990.80 p < 0.001 ** group ii: ppd < 4 mm(n=20) 82.36 ± 7.85 group iii: control(n=20) 11.67 ± 3.32 ** indicates 5% level of significance (p < 0.05). the f value is based on one-way anova table 3: tukey's test results multiple comparison of salivary il-6 level between the groups. study groups dependent variable groups compared significance salivary il-6 level (ng/l) mean difference qp-value group i: ppd ≥ 4 mm 114.43 ± 9.74 i vs iii 102.77 ± 11.13 41.31 p < 0.001 group ii: ppd < 4 mm 82.36 ± 7.85 ii vs iii 70.70 ± 8.77 36.28 p < 0.001 group iii: control 11.67 ± 3.32 i vs ii 32.07 ± 11.52 12.45 p < 0.001 discussion periodontal disease consequences from release of inflammatory mediators, and the result is a significant breakdown of tooth supporting tissues, finally leading to tooth loss(22). the intensity, duration and resolution of inflammation depend on shifting balance between the activities of proinflammatory and anti-inflammatory cytokines during periodontal inflammation (23,24).il-6 has multiple biological activities. early production of il-6 during infection and through differential control of leukocyte recruitment, activation and apoptosis – has emerged as one of a network of mediators directing this shift from innate immune response to an adaptive immune response(18). considering the above mentioned functions of il-6 and its role in various chronic diseases, including periodontal disease, we tried to evaluate and compare the levels of il-6 in saliva in healthy and chronic periodontitis patients. periodontal disease and ppd were taken into consideration to assess the connective tissue destruction and bone loss. results of the present study showed that the mean concentration of salivary il-6 was significantly elevated in chronic periodontitis subjects as compared to controls (p < 0.001). these data are consistent with previous findings of costa et al.,(8)and ebersole et al.,(25)which shows significantly higher salivary j bagh college dentistry vol. 28(1), march 2016 interleukin6 level oral and maxillofacial surgery and periodontics 106 il-6 levels in patients with chronic periodontitis as compared to subjects with healthy periodontium. also geng et al.,(26)reported significantly higher salivary il-6 concentrations in chronic periodontitis in comparison with healthy control group.with regard to periodontal diseases, a reverse transcription polymerase chain reaction (rt-pcr) and elisa studiesobservedthat the mrna expression, as well as protein expression, of il-6 was increased in patients with periodontal diseases than in healthy control subjects(27,28). the results of the present study for the il-6 levels, obtained using elisa, were consistent with previous findings. on the contrary teles et al., (29)). in their study on 118 subjects; 74 chronic periodontitis and 44 periodontally healthy individuals, measured the salivary levels of different cytokines, including il-6 by elisa method. they stated that the levels of il-6 were higher in patients with chronic periodontitis than the healthy individuals but statistically not significant. higher concentrations of salivary il-6 in periodontitis patients compared to healthy controls were reported by ramseier et al.,(30)although differences did not reach statistical significance. results obtained in current study indicated that mean concentration of salivary il-6 was significantly elevated in patients with ppd ≥ 4mm group as compared to control group (114.43 ± 9.74 vs 11.67 ± 3.32, q=41.31; p< 0.001). even after comparing patients with ppd ≥ 4 mm group with ppd < 4 mm group (114.43 ± 9.74 vs 82.36 ± 7.85, q=36.28; p< 0.001) a significant increase was noticed. moreover, when comparing among all three groups, salivary il-6 level increased significantly from the control to the sever periodontitis group (p< 0.001). this clearly proves that chronic periodontitis patients with ppd ≥ 4mm group alone contributed much to the difference found in salivary il-6 level as compared to the chronic periodontitis as seen with ppd < 4 mm group as well as with control groups. thus, the presence of elevated levels of il-6 in the saliva of patients with chronic periodontitis ppd ≥ 4 mm group , along with the significant association with extent of probing pocket depth or clinical assessments of periodontal destruction, strongly suggests an important role for this mediator in the pathogenesis of periodontal disease. similar results were obtained by javed et al.,(31) they proved that there is a significant correlation between the level of il-6 in saliva and the clinical parameters such as ppd, cal and bop, where they found an increase in the salivary il-6 levels as the severity of the periodontal disease increased. research by guillot et al.,(19)observed a significant correlation between tissue levels of il-6 and the severity of the coincident inflammation and demonstrated that il-6 in gingival crevicular fluid impacts the severity of periodontal disease and is associated with clinical attachment loss. in addition, higher il-6 levels have been observed in sites of refractory periodontitis compared to sites of stable, advanced periodontitis, which suggests that it could be a diagnostic marker for sites of active periodontal disease(19).this may be explained by the fact that the increased levels of il-6, with other factors seen in patients with periodontitis may be associated with the destruction of periodontal tissue and resorption of bones(32). kurihara(33),proved that il-6 which is locally produced by osteoclasts, which is very important factor regulating differentiation of these cells and takes part in the processes of resorption. this result also comes in agreement with and extend the overall findings that il-6 seem to be key biomarkers that are elevated in the oral fluids of periodontal patients(4,34). altogether, these studies suggested that the increased levels of inflammatory cytokines, particularly il-6 in periodontitis may have diagnostic and prognostic potentials for the monitoring of the disease and therapeutic decision. further, findings in a recent study believed that salivary il-6 reflects the response of mucosal immune system (35).a study by seymour and colleagues (36)demonstrated that inflammatory cytokines in whole saliva might be derived from gingival crevicular fluid (gcf). this demonstrates the importance of considering local concentrations of inflammatory cytokines in periodontal diseases. it has been stated that bacteria penetration and particularly lipopolysaccharide (lps) into the tissues results in the recruitment and activation of the monocyte/t lymphocyte axis. this leads in turn to increase secretion of inflammatory cytokines including (il-1β, il-6, and tnf-α) by tissue inflammatory cells, which have been associated with periodontal tissue destruction (37). in conclusion, it could be hypothesized that il-6 is produced locally by tissue cells in response to an inflammatory stimulus and by salivary gland cells, reflecting the response of the mucosal immune system. despite the source of the il-6, it is appropriate to assess immunologic patterns relevant to systemic or local disease conditions(38). finally,conclusionof the present study is that the salivary level of il-6 was directly proportional with the extent of probing pocket depth, suggesting that il-6 in saliva can be considered as j bagh college dentistry vol. 28(1), march 2016 interleukin6 level oral and maxillofacial surgery and periodontics 107 one of inflammatory biomarkers of severity of periodontitis. references 1. miller cs, foley jd, bailey al, campell cl, humphries rl, christodoulides n, et al. current developments in 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a, mehmmod a and brain c. whole salivary interleukin-6 and matrix metalloproteinase-8 levels in patients with chronic periodontitis with and without prediabetes. j periodontol 2014; 85(5):e130-5. 32. gabay c. interleukin-6 and chronic inflammation. arthritis res ther 2006;8(s2):s3-s6. 33. kurihara n, bertolini d, suda t. il-6 stimulates osteoclast-like multinucleated cell formation in long term human marrow cultures by inducing il-1 release. j immunol 2005; 144: 4226-30. 34. noh mk, jung m, kim sh, lee sr, park kh, kim dh, kimhh, park yg. assessment of il-6, il-8 and j bagh college dentistry vol. 28(1), march 2016 interleukin6 level oral and maxillofacial surgery and periodontics 108 tnf-α levels in the gingival tissue of patients with periodontitis. exp ther med 2013;6:847-51. 35. sjögren e, leanderson p, kristenson m, ernerudh j. interleukin-6 levels in relation to psychosocial factors: studies on serum, saliva, and in vitro production by blood mononuclear cells. brain behav immun 2006; 20:270-8. 36. seymour ra, ellis js, thomason jm risk factors for drug induced gingival overgrowth. j clin periodontol 2000; 27:217-23. 37. kamma jj, giannopoulou c, vasdekis vgs, mombelli a. cytokine profile in gingival crevicular fluid of aggressive periodontitis: influence of smoking and stress. j clin periodontol 2004;81:894902. 38. streckfus c, bigler l, navazesh m, al-hishimi i. cytokine concentrations in stimulated whole saliva among patients with primary sjogren's syndrome, secondary sjogren's syndrome and patients with primary sjogren's syndrome receiving varying doses of interferon for symptomatic treatment of the condition: a preliminary study. clin oral investig 2001; 5:133-5. inas f.doc j bagh college dentistry vol. 25(2), june 2013 the effect of anti-oxidant restorative dentistry 18 the effect of anti-oxidant agents as neutralizers of bleaching agents on dentin bond strength ayad mahmoud al-bayaty, b.d.s. (1) inas i. al-rawi, b.d.s., m.sc. (2) abstract background: reduction in bond strength when bonding was done immediately after intracoronal bleaching procedure has been recognized. the purpose of this study is to assess the effect of antioxidants (10% sodium ascorbate (sa), 0.1m thiourea and7% sodium bicarbonate (sb)) on reversing bonding strength of composite resin to bleached dentin. materials and method: sixty upper 1st premolar teeth, were selected, the crowns of the teeth were embedded in acrylic resin blocks exposing a flat dentin from the buccal surface, then divided into 6 groups (10 samples each). bleaching for the experimental groups was performed using 35% hydrogen peroxide bleaching gel (pola–office).group a (negative control group; dentin samples immediately bonded with composite without bleaching)group b (positive control group; dentin samples bleached and immediately bonded with composite). group c (dentin samples bleached and stored for 14 days in ddw then bonded with composite). group d (dentin samples bleached and treated with 10% (sa) then immediately bonded with composite). group e (dentin samples bleached and treated with 0.1m thiourea then immediately bonded with composite). group f (dentin samples bleached and treated with 7% sb then immediately bonded with composite).the shear bond strength was determine using instron testing machine. results: bleaching the dentin with 35 % hydrogen peroxide gel for 24 minutes resulted in reduction in bond strength of the bleached teeth when bonding was performed immediately after bleaching. delayed bonding of composite to the bleached dentin for 14 days will result in a highly significant increase in the shear bond strength. conclusion: treating the bleached dentin with 10% (sa) in water base showed a highly significant increase in the shear bond strength of the composite to dentin and reversing the bond strength value to the level of the unbleached dentin. treating the bleached dentin with 0.1m thiourea significantly increased the shear bond strength of the composite to dentin. key words: anti-oxidant, sodium ascorbate, thiourea, bleaching agent. (j bagh coll dentistry 2013; 25(2):18-23). الخالصة الغرض من 0السنان داخل التاجخالل السنوات الماضیھ الحظ الباحثون النقص الحاصل في قوة الربط القصي عن اجراء اللصق االني للحشوة الضوئیھ مباشرة بعد عملیة قصر ا على قدرتھاعلى اعادة الربط القصي لمادة ) بیكاربونات الصودیوم% 7مول ثایویوریا و 0,1اسكوربات الصودیوم ،% 10(اجراء ھذا البحث ھو لتقییم تأثیر موادمضادات التأكسد والنتائج 0%35ولھذا الغرض الغرض تم اختیار ستون سن من الضواحك وتم قصرھا بأستخدام بیروكسید الھیدروجین بتركیز 0الراتنج المركب الى سابق عھدھاقبل عملیة القصر اسكوربیدات الصودیوم نتج عنھ زیادة عالیة في قوة الربط القصي بین مادة الكمبوزیت والعاج واعادة قیمة قوة االلتصاق الى % 10ة اثبتت بعد معالجھ عینات العاج المقصورة بماد نات العاج المقصورة بمادة احصائیا لم تكن ھناك زیادة ملموسة في قوة الربط القصي بین مادة الكمبوزیت والعاج المقصور عند معالجة عی 0مستوى االلتصاق مع العاج الغیر مقصور 0بیكاربونات الصودیوم% 7 introduction esthetic dentistry is an integral part of any restorative dental practice; one important aspect of esthetic dentistry is bleaching combined with esthetic restorative treatment (1). investigations found that bond strength of composite resin is remarkably reduced when bonding was performed immediately after bleaching procedure (2, 3). various theories have been proposed to explain the effect of bleaching on the bond strength of composite resin to teeth. bleaching with hydrogen peroxide may result in significant decrease of enamel and dentin calcium and phosphate content and in morphological alteration in the most superficial enamel crystallites (4, 5). (1) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad (2) professor, department of conservative dentistry, college of dentistry, university of baghdad other authors speculated that residual peroxide and/or oxygen radicals in bleached teeth interfere with the polymerization of adhesive restorative material and decrease bond strength (3). several methods have been proposed to minimize problems related to the reduced bond strength that follows bleaching. the most common method is to delay any bonding procedure for 2-3 weeks after bleaching (3).the adverse effect of bleaching could also be reduced by treating the bleached surface with alcohol or acetone based adhesive (6). recently other methods have been used to remove residual peroxide from bleached tooth by using catalase enzyme or using antioxidants to neutralize the effect of oxygen in bleached teeth (7-10). based on the results of clinical study we can recommend use of antioxidant after endobleaching to achieve successful dental fillings in clinical practice (11). j bagh college dentistry vol. 25(2), june 2013 the effect of anti-oxidant restorative dentistry 19 the aim of this study is to evaluate and compare the effect 35% hydrogen peroxide (pola office) on shear bonding strength of composite to dentin when bonded immediately or delayed to 14 days after bleaching, evaluate and compare the effect of three antioxidants (10% sa, 0.1m thiourea and 7% sb) on shear bonding strength of composite to dentin immediately after the bleaching with 35% h2o2. materials and methods selection and preparation of samples: sixty extracted human upper 1st premolar teeth that are extracted for orthodontic purposes cleaned with tap water and a toothbrush and stored in ddw at 4°c until use. the teeth were examined using a magnifying lens (x10) and transillumination to identify any cracks in the buccal surface of the teeth. the root portions were ground at the level of cej with a diamond disk (meisinger-germany) in a high – speed hand piece (qd england) equipped with water spray. retention grooves were placed on the proximal surfaces of all the teeth with diamond fissure bur (swiss tec-switzerland) (12, 13). construction of the acrylic blocks a metal mold 1.5x1.5cm was fabricated for this study so that the buccal surface of the tooth is out of the acrylic surface to ensure the standardization of the cutting. the metal piece is covered with a dental wax (poly wax®, modeling wax (bìlìm chemical company ìzmìr /turkiye) and pressed to the buccal surface of the tooth, so the tooth became fixed to it and the self-cure acrylic is added to the mold. the buccal surface of each tooth was ground flat with rotofix machine, 2mm in depth using wet 600 grit silicon carbide abrasive disks (13). the abrasive disks were replaced for every 10 samples.the ground buccal surfaces of dentin specimens were washed with ddw for 30 seconds. the acrylic blocks then stored in ddw for 48 hours at 37°c (12). sample grouping: the samples were divided into six experimental groups as shown in table (1) bleaching procedure: the bleaching process was done according to the manufacturer instruction: a thick layer of gel(pola–office; sdi-limited), was applied to dentin surface undergoing treatment by brush applicator and leave the gel on the dentin surface for 8 minutes, each sample three times application of pola office gel and cured for 30 second using light curing unit (type; ydl) for each application. after that the polaoffice gel was suctioned from the samples by using a surgical aspirator tip (pola office manufacture of sdi dental esthetic products aus. 2007). then the samples were washed using a continuous jet of ddw /air spray for one minute to dissolve the bleaching agent on the bonding site, and dried with compressed air syringe for 30 seconds (12). table 1: samples grouping. groups type of samples size treatments a negative control group 10 dentin samples + ibond + composite (immediately bonded). b positive control group 10 dentin samples + 35% h2o2 + ibond + composite (immediately bonded). c bleached experimental 10 dentin samples + 35% h2o2 + 14 days delayed + ibond + composite (delayed bonded). d bleaching + 10%sa experimental 10 dentin samples + 35% h2o2 + 10% sa + ibond + composite (immediately bonded). e bleaching + 0.1m thiourea experiment al 10 dentin samples + 35% h2o2 + 0.1m thiourea + ibond + composite (immediately bonded). f bleaching + 7%sb experimental 10 dentin samples + 35% h2o2 + 7% sb + ibond + composite (immediately antioxidants preparation and application: all the antioxidant agents (10% sa, 0.1m thiourea and 7% sb) were prepared freshly before use and placed in dark plastic containers. the antioxidants were applied immediately after the bleaching procedure, for 8 minutes (1/3 of the bleaching time) (7, 8); using dental brush (one application every 15 seconds) (12) .the amount of liquid applied to each sample was 0.5ml. this application protocol was used to keep the dentin surface of the sample continuously wet j bagh college dentistry vol. 25(2), june 2013 the effect of anti-oxidant restorative dentistry 20 a b c d e f 0 2 4 6 8 10 12 14 16 18 20 mpa 1 2 3 4 5 6 groups with antioxidants during the (8 minutes) application time. standardization of the washing procedure was done by keeping the air syringe away from the acrylic block that holds the tooth by 1cm for two minutes. bonding procedure: the self-etched one component adhesive, (ibond® gluma inside. germanyheraeuskulzer) was applied onto the experimental dentin surface area according to the manufacturer instruction using a microbrush applicator and applied in 3 successive layers to the prepared dentin. following application allow ibond to take effect for 30 seconds then carefully dry with a gentle stream.. polymerize ibond with a conventional halogen curing light for 20 seconds (23). application of composite: the composite resin (microfilledhybrid composite resin (ice from sdi-limited, shade a1) restoration was applied according to manufacturer instruction; the cylinder ( a transparent standardized plastic mold with an internal diameter of 2mm & 3mm in height) was positioned vertically onto the bonding sites was loaded completely with composite resin using a plastic instrument, the vertical position was checked using a rectangular ruler and using a device specially designed for standardization of composite application and curing. (13) .the plastic tube and the sticker paper were sectioned carefully with a new surgical blade (no.22) and removed very carefully. the specimens were stored in ddw for 48 hours at 37°c until testing (12). testing: shear bond strength was evaluated with instron testing machine-1122, using a stainless steel chisel -shaped rod with a crosshead speed of 0.5 mm per minute the load cell was set at 100 kg (14, 22). sta ti sti c a l a na l y si s: analysis of variance (anova) test was performed to identify if there is any statistical significant differences among the experimental groups. paired t-test was used to find any statistical significant differences between each two groups, the probability was highly significant difference at (p<0.001), significant difference at (p<0.05) and no significant difference at (p>0.05). results the mean (sbs) of all the groups are presented in figure (1). it is clear from this bar chart that group a (negative control group) shows the highest sbs (19.493 mpa) while the group b positive control group (bleached specimens and then immediately bonded with composite without antioxidant) gives the least sbs (9.871 mpa) figure 1: the mean of the shear bond strength values in mpa for each group. comparison between all groups: the statistical analysis of sbs of all the groups using (anova) test showed a highly significant differences (p<0.001) among the groups as shown in table (2). table 2: analysis of variance (anova) of sbs of all the groups. effect of bleaching on sbs of composite to dentin: to analyze the influence of the bleaching agent (pola-office 35% h2o2) on the sbs using t-test the result showed a highly significant difference (p<0.001) between group a (negative control group) and group b; positive control group table (3). to analyze the influence of time on the sbs the result showed no significant difference in sbs (p>0.05) between group a and group c (bleached specimens and delayed 14 days, storage in ddw at 37˚c then bonded with composite) table (3). sig f mean square df sum of squars .000 52.903 176.673 5 883.364 betwen groups 3.340 54 180.337 within groups 59 1063.701 total j bagh college dentistry vol. 25(2), june 2013 the effect of anti-oxidant restorative dentistry 21 table 3: comparison between negative control group (a) and other experimental groups using paired t-test. the result showed a highly significant difference (p<0.001) between group c and group b; positive control group table (5), when we compare between group c and antioxidants groups (group d, e and f). the study showed no significant difference (p>0.05) in sbs between group c and group d (bleached specimens then treated with 10% sa and then immediately bonded with composite), and there was a highly significant difference (p<0.0001) in sbs between group c and group e, and between group c and group f (bleached specimens then treated with 7% sb table (5). discussion it is obvious from the results of this study that highly significant difference (p<0.0001) in sbs between group a and group b .the reduction in bond strength was obvious in spite of short application time of the bleaching gel (24 minutes), and this was noted by many researchers regardless the concentration or the type of the bleaching agents used (7, 8, 9) .this reduction in bond strength could be caused by residual solution in the collagen matrix and dentinal tubules that eventually broke down to oxygen and water, liberation of oxygen could either interfere with resin infiltration into dentinal tubules prevents bonding resin from flowing into the tubules and its presence appears to cause small bubbles to form in the resin which are restricted to the side of tubule orifices, or inhibit polymerization of resins that cure via a free-radical mechanism (7). when the specimens were bleached and stored 14 days in ddw then bonded with composite (group c), this caused a highly significant increase in bond strength value when compared with positive control group b (table-5), this finding explained that there is a relation between the bond strength and the time of bonding elapsed after bleaching, however, storage in ddw table 4: comparison between group b (positive control group) and antioxidant groups and between antioxidant groups themselves using paired t-test table 5: comparison between group c and other experimental groups using paired ttest. did reverse the bond strength to the value of the non bleached teeth group a the result showed no significant difference in sbs (p>0.05) between negative control group (group a) and group c as shown in table (3) and it can be concluded from the findings of the study that no additional waiting period is needed to reverse the bond strength of the bleached teeth to the level of unbleached teeth.these findings could be as a result of leaching of hydrogen peroxide after water storage(15). when the bleached specimens were treated with 10 % sa in water base (group d), the result showed a highly significant difference (p<0.0001) in shear bond strength value when compared with positive control group b table (4). the 10% sa can help to neutralize and reverse the oxidizing effects of hydrogen peroxide in biological systems by restoring the altered redox potential of the oxidized bonding substrate, sa allows free-radical polymerization of the adhesive to proceed without premature termination, and hence reverses the compromised bonding in hydrogen peroxide(16). it has been observed that 10% sa did reverse the bond strength of the bleached dentin to the value of unbleached dentin (negative control groups mean mean diff. t-test p-value a 19.493 9.622 10.157 0.000 hs b 9.871 a 19.493 1.532 1.369 0.204 ns c 17.961 a 19.493 2.486 2.121 0.063 ns d 17.007 a 19.493 7.964 10.710 0.000 hs e 11.529 a 19.493 8.857 8.888 0.000 hs f 10.636 groups mean mean diff. t-test p-value b 9.871 -7.136 8.438 0.000 hs d 17.007 b 9.871 -1.658 3.180 0.011 s e 11.529 b 9.871 -0.765 1.457 0.179 ns f 10.636 d 17.007 5.478 6.879 0.000 hs e 11.529 d 17.007 6.371 9.855 0.000 hs f 10.636 e 11.529 0.893 1.821 0.102 ns f 10.636 groups mean mean diff. t-test p-value c 17.961 8.090 11.111 0.000 hs b 9.871 c 17.961 0.954 0.969 0.358 ns d 17.007 c 17.961 6.432 9.334 0.000 hs e 11.529 c 17.961 7.325 10.252 0.000 hs f 10.636 j bagh college dentistry vol. 25(2), june 2013 the effect of anti-oxidant restorative dentistry 22 group a) there was no significant difference (p>0.05) in shear bonding strength between group a and group d (table 3), it is clear from the results of this study that the use of 10% sa before the bonding procedure can reverse the compromised bonding to bleached dentin when the composite bonded immediately and can achieve successful immediate restorative procedure after endo-bleaching and reducing the total time of the complete esthetic treatment. also the result showed there was a highly significant difference (p<0.0001) in sbs between group d (treated with 10% sa) and group e (treated with 0.1m thiourea) and also between group d and group f (treated with 7% sb) as shown in table (4), this may be due to ascorbic acid and its sodium salt are potent antioxidants that are capable of quenching reactive freeradicals in biological systems, and can help to neutralize and reverse the oxidizing effects of hydrogen peroxide more than 0.1m thiourea or 7% sb(16). when bleached dentin treated with 0.1m thiourea then immediately bonded with composite (group e), it was accompanied with an increase in the shear bond strength of the treated dentin and the results showed that, there was a significant difference at (p<0.05) in shear bond strengthbetween positive control group b and group e (table 4), these may lead to the suggestion that 0.1m thiourea will increase its antioxidant ability to neutralize residual oxygen in bleached dentin, but the results of this study showed that 0.1m thiourea was unable to reverse the bond strength of the treated specimens to the level of negative control group (a) (table 3), also there was a highly significant difference (p<0.0001) in sbs between group c (bleached and delayed bonding with composite) and group e, as shown in table 5), this could be due to residual crystals of thiourea which was left on the bonding site after washing procedure, these unwashed crystals, which could be seen via stereomicroscope, may adversely interfere with bonding procedure, or higher concentration of thiourea may be needed or increase the application time, or/and these could be due to that 0.1m thiourea less potent as antioxidant than 10%, which may affect the bonding procedure(17). the treatment of bleached dentin with 7% sb (group f) resulted in a mild increase, nonsignificant effect on bond strength means compared with positive control group b (table 4), also there was a highly significant difference (p<0.0001) in sbs between negative control group a and group f and between group c and group f and also between group d and group f. these effect may be due to that hydrogen peroxide is known to get destabilized and release hydroxyl and perhydroxyl free radicals and oxygen gas in high ph (>7) environment, thus, the activation of the bleaching gel can be enhanced by raising the ph of the gel by further adding sodium carbonate or sb, to have a large amount of hydroxyl free radicals and hence a large amount of oxygen, that would be released in a very short time and may provide good bleaching action (10, 18, 19),self-etching primers which contain acidic polymerizable monomers dissolve the smear layer, or incorporate it into the bonding interface, as it demineralizes the surface and engulfs the collagen fibrils and hydroxyl apatite crystals (20) .'mild' self-etch only partially dissolves the dentin surface, so that a substantial amount of hydroxyl apatite remains available within a submicron hybrid layer. the interaction of the etching agents with dentin is limited by the buffering effect of the mineral and organic phases, so that the residual crystals of sb may be neutralizing the acidity of the bonding agent and this affect the formation of hybrid layer and affect the bonding procedure (21). under the limitions of this in vitro study, the following conclusion has been drawn: bleaching the dentin with 35 % hydrogen peroxide gel for 24 minutes resulted in reduction in bond strength of composite when bonding was performed immediately after bleaching. delayed bonding of composite to the bleached dentin for 14 days will result in a highly significant increase in the shear bond strength.. treating the bleached dentin with 10% sa in water base showed a highly significant increase in the shear bond strength of the composite to dentin and reverses the bond strength value to the level of the unbleached dentin. treating the bleached dentin with 0.1m thiourea significantly increased the shear bond strength of the composite to dentin. there is a non-statistical significant increase in the shear bond strength of the composite to the bleached dentin that is treated with 7% sb. references 1. attint, hanning c, wiegand a, attin r. effect of bleaching on restorative materials and restorationssystemic review. dent mater 2004; 20(9):852-861. 2. titley kc, torneck cd, ruse nd, krmec d. adhesion of a resin composite to bleached and unbleached human enamel. j endod 1993; 19: 112-5. 3. shinohara ms, peris ar , pimenta la, ambrosano gm. shear bond strength evaluation of composite resin on enamel and dentin after non-vital bleaching. j esthet restor dent 2005; 17(1):22-9; discussion 29. 4. basting rt, rodrigues al jr, serra mc. the effect of 10% carbamide peroxide, carbopol and/or glycerin on j bagh college dentistry vol. 25(2), june 2013 the effect of anti-oxidant restorative dentistry 23 enamel and dentin microhardness. oper dent 2005; 30(5): 608-16. 5. fu b, hoth-hannig w, hannig m. effects of dental bleaching on microand nano-morphological alterations of the enamel surface. am j dent 2007; 20(1): 35-40. 6. kum ky, lim kr, 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filling consequent to the endo-bleaching; georgian med news 2006; 137: 38-42. 12. abdalghani aa. an assessment of the effect of sodium ascorbate antioxidant on the bonding strength of composite resin to the bleached enamel surface. a master thesis, baghdad university, 2005 13. sebeha mehdy kanaan. the influence of different photo-activation methods on the shear bond strength of composite resin to dentin; in vitro study; 2005, baghdad. 14. craig rg, powers jm. restorative dental materials 2002, ch 4, 69-70, and ch.9: p (232-234, 236). 15. torneck cd, titly kc, smith do, adibtar a. the effect leaching on adhesion of composite resin to bleached and unbleached bovine enamel. j endo 1991; 71:156-160. 16. carr ac, tijerina t, frei b. vitamin c protects against and reverse specific hypochlorous acidand chloramines-dependent modifications of low-density lipoprotein. biochem j 2000; 2: 491-99. 17. thiourea from: wikipedia, the free encyclopedia: http://en.wikipedia.org/wiki/ thiourea. 3/4/ 2007. 18. abhijit, banerjee, joshua, and friedman: dental bleaching gel composition and activator.us patent issued on june 21, 2005. © 2004-6 patentstorm llc. 19. banerjee, abhijit, friedman, joshua : dental bleaching gel composition, activator system and method for activating a dental bleaching; 2002, http://www.freepatentsonline.com/20020141949.html 20. jacques p, josimeri h. effect of dentin conditioners on the micro tensili bond strength of a conventional and a salf – etching primer adhesive system. dental mater 2005; 21 (2): 103-109. 21. peumans m, kanumili p, munck j, landuyt k. clinical effectiveness of contemporary adhesives: a systematic review of current clinical trials. dental mater 2005; 21 (9): 864-881. 22. iso /ts 11405:2003(e).technical specification; dental material testing of adhesion to tooth structure, 2nd ed. 23. heraeuskulzer gmbh division dentistry; 2007. www.heraeus-kulzer.com. http://en.wikipedia.org/wiki/ http://www.freepatentsonline.com/20020141949.html http://www.heraeus-kulzer.com sana f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 regulation of oral and maxillofacial surgery and periodontics 102 regulation of hba1c of uncontrolled diabetic type ii obese and normal weight patients by oral hygiene performance (comparative study) sana f. hadratie, b.d.s. (1) abdullatif a.h. al-juboury, b.d.s., ph.d. (2) abstract background: the association between periodontal diseases incidence and development and the metabolic diseases as diabetes mellitus and obesity are recently have attract great deal of researchers attention and investigation. the periodontal health proved to reduce the systemic inflammatory reactions and positively improve the glycemic control of diabetes type2 patients. the aim of the study was to investigate the influence of oral hygiene control on the glycemic control of obese and normal weight moderately controlled diabetic type 2 patients, in addition to study the association of obesity with the gingival inflammation. materials and methods: cross sectional study of three months duration. included 30 moderately controlled diabetic type2 patients who attend the specialist center for endocrine and diabetes diseases baghdad al-russafa administration / iraqi ministry of health, were grouped into two groups, g1 of normal weight diabetics, and g2 obese diabetics according to their bmi level, the oral hygiene status measured by their pli,gi,bbop,pdi,cal was conducted at each of the five visits of three weeks interval between each till the end of three months duration of the study and the level of their glycemic control measured by hba1c level was conducted at the first and the fifth visit of the research duration , bmi was measured at the first and the fifth visit also. paired t-test, anova, qui-square and pearson correlation statistical analysis was used to investigate the significance of the improved glycemic control after oral hygiene control (ohc) of both g1 and g2. results: periodontal parameters of both g1 and g2 were significantly improved after ohc with a significant reduction in hba1c level of both normal weight and obese patients. conclusion: the oral hygiene control (ohc) is sufficient to improve reduction in diabetes control level with or without overweight.ohc home care and professional measures could improve the gain in periodontal health in normal weight diabetics and overweight diabetics obesity has an association with the presence of bleeding on probing as an indicator of the gingival inflammation in diabetic type2 patients. key words: periodontitis, diabetes type ii, oral hygiene. (j bagh coll dentistry 2013; 25(special issue 1):102-107). introduction diabetes mellitus, the clinical syndrome characterized by hyperglycemia caused by absolute or relative deficiency of insulin (1).the prevalence of diabetes for all age-groups worldwide was 2.8% in 2000 and estimated to be 4.4% in 2030. the prevalence was higher in men than in women (2). about 85%-90% of diabetic cases are type 2 dm, while type 1 constitutes 5%-10% of the cases (3).obesity is a global rising problem all over the world; can be defined as an excess amount of body fat in proportion to the lean body mass (4) to the extent that health is impaired (5). the world health organization who defines obesity as a bmi > 30 (5) which in turn reflected by increased waist circumference (6),certain ethnic groups seem to be more sensitive than the other to develop its adverse metabolic effects than the others that high levels of diabetes and related diseases are found in south asia and arab populations (6). the adipose tissue (body fat) is no longer considered as a storage of triglycerides, but a complex and metabolically active endocrine (1) master student. department of periodontics. college of dentistry. university of baghdad. (2) professor. department of periodontics. college of dentistry. university of baghdad. organ that secretes numerous immunomodulatory factors collectively called adipokines, where some of them act locally and the others released into the systemic circulation to act as signaling molecules to the liver , muscles , and endothelium (7).through these immune factors obesity emerged one of the risk factors of developing periodontal diseases, systemic health problems such as diabetes type 2 and cardiovascular diseases (8).through these immune factors obesity emerged one of the risk factors of developing periodontal diseases. the effect of dm on the periodontal diseases development: although periodontitis is a recognized complication of diabetes, people with well-controlled diabetes who have good oral hygiene are not at increased risk of developing periodontitis. however, their susceptibility to periodontitis is significantly increased when their diabetes is poorly controlled, particularly if they are smokers (9). in addition they are at high risk of disease progression (10). type of microbial oral flora in diabetic was studied by many researchers, campus et al showed a higher prevalence of p.gingivalis was demonstrated in type 2 diabetics compared to non-diabetic control subjects using polymerase chain reaction (pcr) on using checker board dna-dna hybridization , j bagh college dentistry vol. 25(special issue 1), june 2013 regulation of oral and maxillofacial surgery and periodontics 103 treponema denticola , streptococcus sanguinis ,prevotella, nigrescens , staphylococcus intermedius and streptococcus oralis levels were elevated in supra-gingival plaque of diabetic compared to non-diabetics, although, no significant differences were found in the subgingival plaque samples(11).the periodontal tissues with large amounts of ages content are characterized by higher shared susceptibility between these two common diseases can be summarized as (12): • role of biochemical changes including hyperglycemia and ages formation. • role of immunological activity such as cytokines and adipokines (in obese diabetic patients) such as il-6 and tnf-α. role of advanced glycation end-products (ages): ages are the result of non-enzymatic glycation and glycoxidation processes and are formed on proteins ,lipids and nucleic acids in a pro-oxidant environment , their formation is enhanced with concomitant hyperglycemia and delayed macromolecular turnover(13) ages may be deposited on mononuclear polymorphonuclear cells, inhibiting their chemotactic and phagocytic capacities and permitting the advance of gramnegative anaerobic bacteria, which explain the high prevalence and severity of periodontal diseases in diabetic patients(14) . diabetics have defective neutrophil apoptosis which may result in increased retention of pmnl within the periodontal tissues and contribute to tissue destruction by non-specific release of matrix metalo-proteinase mmps and reactive oxygen species (ros),providing a further mechanism for increased susceptibility to periodontal diseases in addition , age-stimulated macrophages and pmnl cells releasing a larger amount of cytokines and soluble mediators and producing a greater destruction of c.t in these patients as a hyper-response to. the progression of bacterial biofilm 15, 16) role of immunological activity (cytokines and adipokines): type2 diabetes is proposed to cause substantial changes in immunologically active molecules and perturb the finally ,balanced cytokine networks within the periodontium, which in turn affect the localized immune responses and altered the susceptibility to periodontal diseases.(17) the inflammation associated with the periodontal diseases , characterized by elevated proinflammatory cytokines ,innate immune receptor expression (tlr-4) and cellular infiltrate is exacerbated in with type 2 diabetes, with a feed forward loop regulated by poor glycemic control was associated with a loss of mucosal barrier integrity and accumulation of innate immune receptor ligands resulting in an exacerbation of an ongoing inflammation(18) effect of periodontitis on diabetes mellitus: periodontal diseases are prevalent in most populations and may have wide-range of systemic effects in susceptible individuals and may act as a potential independent risk factor for diabetic complication and exacerbating the existing disorder of the patient.(19)evidence suggests that periodontitis –induced bacteremia cause an elevation in serum pro-inflammatory cytokines (il-1β and tnf-α) which have been demonstrated to produce alterations in lipid metabolism leading to hyperlipidemia and alternately causing an insulin resistance syndrome and contributing to destruction of pancreatic bcells leading to the development of diabetes(20) persistent elevation of il-1β,il-6 ,tnf-α in the diabetic state have an effect on the liver ,stimulate the release of acute-phase proteins crp ,produce the characteristic dysregulation of lipid metabolism associated with type2 diabetes and have an effect on pancreatic b-cells as well.(21) obesity and periodontitis: obesity has both local and systemic inflammatory networks by which obesity exert its effects on the body systems, these networks governed by the secretion of adipokines, pro-inflammatory cytokines and reactive oxidative species. the first reported observation on the relationship between obesity and the periodontal diseases was made by perlsteinet al.in 1977; they observed histopathological changes in the periodontium in hereditary obese zucker rats. on using ligatureinduced periodontitis, they found alveolar bone resorption to be greater in obese animals compared with non-obese rats that the obesehypertensive rats showed the most severe periodontal response to local irritation (22). based on reviewing the nhanes iii, obesity could be a potential risk factor for periodontal diseases especially among younger individuals andthat promotion of healthy nutrition and adequate physical activity may be additional factors to prevent the rate of progression of periodontal diseases. (23) as obesity is generally the first step toward type2 dm, it is possible to find exacerbated periodontal diseases in obese patients (24). obese subjects with a high serum triglyceride level and/or a low hdl-cholesterol level could be at higher risk of periodontal infection. and that the association between body weight and periodontal infection was mainly mediated through a mechanism other than serum lipids (25). the relationship between obesity and periodontal diseases is dose-dependent relation that, overweight individuals had double the j bagh college dentistry vol. 25(special issue 1), june 2013 regulation of oral and maxillofacial surgery and periodontics 104 incidence ,while obese had triple the incidence ,severity and extent of periodontal diseases.(26) obesity showed correlation with greater attachment loss in obese than in non-obese(27) effect of periodontal diseases on obesity: some studies suggest that periodontal pathogens can contribute to obesity development. goodson’s et al, suggest three mechanisms by which oral bacteria may contribute to the development of obesity, the first hypotheses suggests that oral bacteria may contribute to increased metabolic efficiency .the second suggest that oral bacteria could increase weight gain by increasing appetite, and the third one suggests that oral bacteria redirect energy metabolism by facilitating insulin resistance through increasing levels of tnf-α or reducing levels of adiponectin. by any of these three mechanisms, even a small calorie consumption with no change in diet or exercise could result in an unacceptable weight gain (28) the effect of oral bacteria on obesity development is further confirmed through the effect of periodontal treatment aimed at elimination of the periodontal -pathogens on the improvement in the lipid profile of treated patients, as was observed by tandon et al (29) effect of periodontal treatment on glycemic control of diabetics: the anti-inflammatory periodontal treatment (scaling and root planning ) can be hypothesized to improve insulin sensitivity by reducing the peripheral tnf-α concentration and by which exert a beneficial effect on the metabolic control of type2 diabetic patients.(30) a meta-analysis of ten intervention studies to estimate the effect of periodontal treatment on hba1c found a weighted mean reduction of 0.66% in type 2 dm patients ,however, this did notachieve a statistical significance.(31) the prevention of periodontal disease is an important diabetic task , that an aggressive management of oral health and regular check-up in diabetic patients may diminish the inflammatory effects on diabetes control.(32)reduction of periodontal inflammation either with root planning and systemic antibiotics or with plaque control and sub-gingival scaling significantly reduces crp levels (33), significant decrease in total and ldl cholesterol levels (34), and decrease in the level of some circulating pro-inflammatory cytokines and may be associated with a decrease in insulin resistance in the obese patients (35). materials and methods after gaining the college ethical committee’s approval on the study protocol and the iraqi ministry of health approval on the use of human subjects in this study ,the sample recruited for the study were patients attending the specialized center for endocrinology and diabetes ,and alkindy teaching hospital -baghdad /al-russafa administration.30 of moderately controlled diabetic type 2 patients were participated and divided into two groups according to their bmi level into g1 of normal weight (bmi>=22) and g2 obese patients (bmi>=30)both having moderate chronic periodontitis of pocket depths>=4mm and clinical attachment loss >=6.00 mm. both groups participants are uncoholic ,non-smokers ,with no previous periodontal treatment or systemic medication other than their hypoglycemic drugs for about two months before or during the study. an adequate elimination of the sub-gingival plaque, in addition to the use of chlorehexidine mouth wash twice a day for the week after scaling). results both groups were at the same level of the metabolic control at the beginning of the study (day zero) {table 1}. the oral hygiene control (ohc) measures included the daily home care (teeth brushing, flossing and interdental brushing) enforced by the professional scaling at the first visits. pli,gi,bop,pdi,and cal were recorded at day zero and reevaluated for the next four visits (with three weeks interval between each), bmi, and hba1c levels were measured at day zero and after three months to adjust the effect of the oral hygiene control measures on the glycemic control of each group.after three months of ohc, the hba1c level showed a highly statistical reduction in both groups(g1 and g2) with no significant reduction in bmi level forboth groups.{table2,3},oral hygiene status measured by pli,gi, and bop showed highly significant reduction for both groups {tables 4,5}, the pocket depth index show a highly significant reduction in g1 accompanied by highly significant reduction in cal {table 4}while, in g2 the highly significant reduction in pdi was accompanied by not significant reduction in cal {table 5}.the intergroup comparison of the pocket depth reduction showed significant difference after ohc, while attachment gain , pli ,gi ,and bop show no significant difference {table 6}. chisquare analysis of the effect of obesity on the health status of the periodontium of both normal weight and obese diabetic patients calculated by bop index before and after ohc revealed that obesity do have an association with the severity of bleeding on propping in both groups {table 7}. j bagh college dentistry vol. 25(special issue 1), june 2013 regulation of oral and maxillofacial surgery and periodontics 105 table1: the intergroup comparison of the metabolic control of both groups at day zero sig. p-value 3 months after treatment sig. p-value mean±sd mean±sd hba1c 0.593±1.255 0.857 ns 0.357±1.327 0.315 ns table2: analysis of the metabolic parameters of g1 (normal weight) before and after ohc: metabolic parameter time of reading mean ±sd t-test pvalue hba1c day zero 3 mon. later 8.457±0.897 7.519±0.977 3.283 0.005 hs bmi day zero 3 mon. later 24.128±0.997 23.866±1.435 1.69 0.112 ns table 3: analysis of the metabolic parameters of g2 (obese) before and after ohc. metabolic parameter time of reading mean ±sd t-test p-value hba1c day zero 3mon. later 8.397±0.70 7.233±0.72 7.41 0.001 hs bmi day zero 3mon.later 32.246±2.17 32.264±2.2 0.213 0.834 ns table 4: analysis of the periodontal parameters of g1 (normal weight) before and after ohc. table 5: analysis of the periodontal parameters of g2 (obese) before and after ohc. time of reading mean ±sd t-test df p-value pli day zero 3mon. later 1.082±0.37 0.054±0.07 10.823 14 0.001 hs gi day zero 3mon. later 1.453±0.40 0.467±0.38 8.787 14 0.001 hs bop day zero 3mon.later 0.54±0.36 0.007±0.02 5.730 14 0.001 hs pdi day zero 3mon. later 4.649±0.77 2.293±1.01 10.28 14 0.001 hs cal day zero 3mon. later 5.788±1.44 4.842±1.30 2.123 14 0.049 ns time of reading mean ±sd t-test df p value pli at day zero 3 mon. later 1.031±0.47 0.096±0.06 7.843 14 0.001 hs gi at day zero 3 mon. later 1.451±0.58 0.065±0.48 6.206 14 0.001 hs bop at day zero 3 mon. later 0.68±0.36 0.09±0.18 6.286 14 0.001 hs pdi at day zero 3 mon. later 5.024±1.25 3.257±1.18 12.9 14 0.001 hs cal at day zero 3 mon. later 6.684±1.30 5.788±1.44 5.214 14 0.001 hs j bagh college dentistry vol. 25(special issue 1), june 2013 regulation of oral and maxillofacial surgery and periodontics 106 table 6: intergroup comparison between the periodontal parameters before and after ohc. periodontal parameter at day zero sig. (p-value) 3 months later sig. (p-value) mean difference ± sd mean difference ± sd pli -0.506±0.726 0.791 ns 0.416±0.105 0.149 ns gi -0.020±0.695 0.991 ns 0.191±0.405 0.89 ns bop 0.144±0.56 0.337 ns 0.085±0.16 0.062 ns pdi 0.374±1.468 0.34 ns 0.964±1.453 0.022 s cal 0.896±1.684 0.058 ns 0.946±1.952 0.082 ns table 7: chi-square analysis of association of bop and obesity before and after ohc. bmi bop scores before ohc chi-square df p-value at 0.05 sig. 0 1 no. % no. % normal weight 412 33.22 828 66.77 33.88 1 3.84 s obese 630 49.14 652 50.85 0.059 ns discussion as periodontal infections contributed to elevated serum inflammatory mediators such as tnf-α, il-6 and pge2, as an innate inflammatory hyper responsiveness to the bacterial challenge, tnfα and il-6 proved to induce insulin resistance and worsen the hyperglycemic state of the diabetics. obese diabetic patients have high levels of serum tnfα and other inflammatory mediators that affect the diabetic control and the periodontal health as well.in our study, 30 patients of moderately controlled type 2 diabetes were participated ,divided into two groups according to their bmi level, as g1 , consist of 15 normal weight diabetics and g2 consist of 15 obese diabetics. both of g1 and g2 were instructed to the proper daily oral hygiene performance, reinforced at different intervals through the visits of the study according to the patients need and scaling to eliminate the bacterial plaque and calculus as a professional partof oh performance. the effect of oh performance and control on the glycemic control of diabetics is measured by hba1c test before and after three months of scaling and oh performance. both groups were at the same oh status before treatment, after three months of ohc measures, pli, gi and bop showed insignificant difference in intergroup analysis indicating an equal oh status and patients’ compliances to the oh instructions , that both g1 andg2 showed a highly significant reduction in pli , gi and bop as described in {tables 4,5} . pdi showed significant difference in the intergroup analysis {table 6} with no significant difference in cal between the two groups after three months of ohc, which could indicate a slight difference in the inflammatory response between the groups, that the insignificant difference in intergroup analysis of the cal with difference in the pdi means that the pocket formed due to enlarged inflamed gingival tissues despite the loss of attachment present as a destructive periodontal disease progression in both groups. the insignificant difference in cal between the groups {table 6} indicates that obesity showed insignificant effect on the outcome of the periodontal treatment of diabetic patients. the improvement in the oral hygiene status was accompanied by a significant reduction in hba1c in both groups. bmi level of g1 showed slight but not significant reduction after three months of treatment {table 2}, that indicates the presence of weight-loss due to the lipolysis that resulted from uncontrolled hyperglycemia of the diabetic and insulin resistance state. while g2 showed slight but not significant elevation of bmi after three months of the study, which could be resulted from the improved periodontal inflammation that enabled the patients to eat better than before {table 3}. chi-square test {table7} of bop of both groups before and after the ohc showed that obesity could have an association with the gingival inflammation measured by the presence of the bleeding sites of both groups. as a conclusion, the oral hygiene control (ohc) is sufficient to improve the diabetes control level with or without overweight. and the improvement in the oh status was accompanied with a highly significant reduction in hba1c in both groups. obesity has an association with the presence of bleeding as an bmi bop scores after ohc chi-square df p-value at 0.05 sig. 0 1 no. % no. % normal weight 1146 92.41 94 7.58 77.87 1 3.84 s obese 1274 99.37 8 0.62 98.13 s j bagh college dentistry vol. 25(special issue 1), june 2013 regulation of oral and maxillofacial surgery and periodontics 107 indicator of the gingival inflammation in diabetic type2 patients. references 1. nicki rc, brian rw, stuart hr. davidson’s principles and practice of medicine 21th ed. churchill livingstone; 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139: 19s-24s. 17. wassall rr, preshaw pm. type 2 diabetes mellitus as a risk factor for periodontal diseases. perio 2006; 3(4): 243-252. 18. amir j, mathew w, jeffrey t et al. the role of hyperglycemia in mechanisms of exacerbated inflammatory responses within the oral cavity. cellular immunol 2011; 272(1): 45-52. 19. tara b, taiyeb a, renukanth p. et al. relationship between periodontal diseases and diabetes mellitus: an asian perspective. periodontology 2000; 56:258-268. 20. iacopino am. periodontitis and diabetes interrelationships: role of inflammation. ann periodontol 2001; 6(1):125-37. 21. grossi sw. treatment of periodontal diseases and control of diabetes: an assessment of the evidence and need for future research. ann periodontol 2001; 6(1):138-45. 22. perlstein mi, bissada mf. influence of obesity and hypertension on the severity of periodontitis in rats. oral surg oral med oral pathol 1977; 43:707-719. 23. al zahrani ms, nabil fb, elaine ab. obesity and periodontal disease in young, middle aged and older adults. j periodontal 2003; 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80(8): 1690-4. 31. janket s j, wightman a, baird ae, van dyke te, jones ja. does periodontal treatment improve glycemic control in diabetic patients? a meta-analysis of intervention studies. j dent res 2005; 84:11541159. 32. schulze a, busse m. periodontal diseases in diabetic: relationship, prevention and treatment. csmi 2008; 1(2):1-4. 33. nestor t, lopez aq et al. effects of periodontal therapy on systemic markers of inflammation in patients with metabolic syndrome: a controlled clinical trial. j periodontal 2012; 83:267-278. 34. gul os, fentoglu o et al. beneficial effects of periodontal treatment on metabolic control of hypercholesterolemia. southern medical j 2007: 100(7):686-691. 35. gurgan ca, altay u, agbaht k. changes in inflammatory and metabolic parameters after periodontal treatment in obese and non-obese patients. j periodontal 2012; pmid: 22348694. http://www.cdc.gov/diabetes/pubs/estimates.htm yasameen.doc j bagh college dentistry vol. 28(1), march 2016 a comparison of restorative dentistry 57 a comparison of the effectiveness of reciprocating system with continuous rotary systems in non-surgical endodontic retreatment (an in vitro study) ayad m. mahmoud al-obaidi, b.d.s., m.sc. (1) yasameen hasan motea, b.d.s., m.sc. (1) abstarct background: optimal root canal retreatment was required safe and efficient removal of filling material from root canal. the aim of this in vitro study was to compare the efficacy of reciprocating and continuous motion of four retreatment systems in removal of root canal filling material. materials and methods: forty distal roots of the mandibular first molars teeth were used in this study, these roots were embedded in cold clear acrylic,roots were instrumented using crown down technique and rotary protaper systemize sx to size f2 ,instrumentation were done with copiousirrigation of 2.5% sodium hypochlorite and 17% buffered solution of edta was used as final irrigant followed by distilledwater, roots were obturated with ah26 sealer and protaper gutta-percha point f2 and medium fine accessory gutta-percha using lateral condensation technique,roots were left for 7 days with 100% humidity at 37ºc in an incubator. roots were randomly divided into four groups according to technique used for removing the root filling material (ten teeth for each group): group i: reciprocating technique and wave one system, group ii: continuous technique and protaper retreatment system, group iii: continuous technique and r-endo system, group iv: continuous technique and d–racere treatment system. all the roots were radiographed before and after removal of gutta-percha from both bucco-lingual and mesiodistal directions using custom made platform and digital radiograph system rvg to havea digitized images. the total surface area of all root canals was measured before removal ofthe gutta-percha and the area of the remaining gutta-percha filling in the canals after retreatment procedure from both directions. these measurements were analyzed with adobe photoshop cs6 software, the percentage of removed gutta-percha calculated. results: statistical analysis was performed and the result showed group ihad the highest mean values in removal of root canal filling material in both bucco-lingual and mesiodistal direction of dental radiograph and there were significant difference between group i and most of the other groups ,there were non significant difference between group ii,group iii and group iv. conclusion: this study was showed all the used retreatment systems did notcompletely remove the root canal filling material. the reciprocating technique was most effective method for removing gutta-percha and sealer than continuous rotary technique. key words: retreatment, reciprocating motion, root canal filling, rotary instrument. (j bagh coll dentistry 2016; 28(1):57-62). introduction safe and efficient removal of the root canal filling material was essential for optimal root canal retreatment. ideally, all sealer androot canal material should be removed from canal walls to regain access to microorganisms and pulptissue remnants thatmightberesponsible for periapical inflammation and thus post treatment disease (1,2). gutta-percha was the most commonly used root filling material in conjunction with a sealer. the proper removal of these materials from inadequately prepared and filled canals required a substantial effort and could be time-consuming and challenging. nevertheless, performing this procedure effectively had an important clinical impact because the irrigating solutions and the instruments used during retreatment could reach the entire root canal system, thus promoting better cleaning and disinfection (3). various techniques were used for removal of gutta-percha such as hand instruments with or without chemical solvents, rotary instruments, heat and ultrasonic devices (4,5). (1)assistant lecturer. department of conservative dentistry, college of dentistry, university of baghdad. the nickel-titanium (niti) rotary instruments used for root filling removal and rootcanal retreatment had been widely investigated (6). their use allowed gutta-percha removal with no solvent(7), thus prevented the formation of a thin film of gutta-percha on the walls of the root canal(8). a new concept was recently introduced, in whichcanal preparation was accomplished using a specificallydesigned nickel–titanium enginedriven instrumentthat employed a reciprocating motion. the same techniquewas also indicated for retreatment purposes, inwhich the instruments were used with a brushingmotion against the lateral walls of the canal toremove any residual filling material (9,10). there were only a few reports analyzed the performance of reciprocating instruments in endodontic retreatment (11). different methodologies had been used for the evaluation of the cleaning efficacy of different endodontic retreatment systems including longitudinal cleavage of teeth (12); association of longitudinal and transverse cleavage for evaluation in thirds and cleavage and j bagh college dentistry vol. 28(1), march 2016 a comparison of restorative dentistry 58 photographic recordingor with the operating dental microscope (13,14). others methods used radiographic examination with different computer software (15). in the present study, radiographic evaluation of the retreatment techniques were used, this method is more reliable as splitting the roots might disturb the remaining filling material (16), bucco-lingual and mesiodistal images were taken and evaluated for each root to overcome the limitation of the radiographic images of providing only two dimensional information,. in accordance with other studies (17). the aim of this studywould be to evaluate the effectiveness of reciprocating system versus continuous rotary systems in endodontic retreatment. materials and methods forty extracted human distal roots of mandibular first molar with mature apices were selected for this study from the clinics of the university of baghdad, college of dentistry. the gender, pulpal status and reason for extractionwere not considered and criteria for teeth selection included the following: mature, centrally located apical foramen, patent apical foramen, roots devoid of any, cracks, resorptions or fractures. samples preparation: the extracted teeth stored indistilledwater at room temperature any remnants of soft tissue and calculus on the external root surface were mechanically removedwithsharp periodontal curette. a magnifying eye lens and light cure device were used toverify the root surfacesfor any visible cracks orfractures.the teeth were decoronated at the cemento-enamel junction using a high speed diamond burwith straight handpiece and water spray and the distal roots separated from the mesial roots. clear cold cure acrylic was mixed andplaced in a rubber mold where the rootswere embedded. a bench vice was used to achieve standardized position of the resin mounted roots throughout the whole procedure. barbed broach was used toremovethe pulpal tissue and the working length of each canal established with size 15 k-file 1mm short of the anatomical apex. the canals were instrumented using a crown-down technique with protaper niti rotary instruments (sx-f2) (densply, maillefer/ switzerland) and e3 torque control electricmotor (dentsply, tulsa) which was set according to manufacture’s instructions. master apical file would be f2 for all canals. alternative irrigation with total of 10 ml of 2.5% of sodiumhypochlorite (naocl) was used for irrigation and the smear layer was removed by irrigating with 5ml of 17% edta for 1 minute thenfollowed by a final rinse of 5 ml of distilledwater to avoid development of naoc1 crystals. the canals were then dried with protaper paper points f2. canal filling: ah 26 root canal sealerwas mixed according to the manufacturer’s instructions .the mixture had a homogenous creamy consistency with string out at least 1 inch when the spatula was raised slowly from the glass slab. the sealer was introduced into the canal using protaper paper point f2 by rotating the paper point twice counter clock wise to coat the canal walls by thin film of sealer.the canals werefilled using the lateral condensationtechnique. the tip of master guttapercha cone corresponding to the last file size f2 (densply, maillefer/ switzerland) was dipped into the sealer and placed into canal. the previously checked finger spreaderwere used for lateral compaction of the master conecreating a space for an additional accessory cone.medium-fine accessory gutta-percha cones were laterally compacted until the spreader could not introduced deeper than 2-3 mm into the root canalorifice. a heated plugger was used to cut the gutta-percha at the entrance of the canal. each canal orifice was sealed by temporary filling. prior to temporary filling placement the specimens were radiographed in bucco-lingual and mesiodistal directions to confirm the adequacy of the root canal obturation and these radiograph images were used later to make measurements of total canals area. all roots were left for 7 days with 100% humidity at 37ºc in an incubator. retreatment techniques: the coronal 2-mm of each root canal filling was removed using gatesglidden burs 2 and 3 (dentsply, maillefer). gutta-percha obturation material was then easily removed from the canal with rotary retreatment files systems.each rotary system wasused withe3torque control electric motor (dentsply, tulsa).the torque and speed settings for each filewere used as recommended by the manufacturer. a total volume of 25 ml of2.5% naocl was delivered from aneedle with30-gauge (tip size 25) during retreatment procedure then the canals were dried with paper points. the roots were randomly divided into four groups of ten roots each. group i: gutta-percha obturation material was removed from the canal with the primary wave one file #25 thatwasapplied in a reciprocating motion. the j bagh college dentistry vol. 28(1), march 2016 a comparison of restorative dentistry 59 silicone stopper was set on the primary wave one file (dentsply, maillefer) at 2/3 of the estimated canal length. primary wave one file was introduced into the canal with a slow in-and-out pecking motion without pulling the instrument completely out of the canal. the amplitude of the inand outmovement did notexceed 3-4 mm. gentle apical pressure wascombined with a brushing action against the lateralwalls. the instrument advanced easily in the obturation material and the canal in an apical direction. after maximum three inand out-movements, or when more pressure was needed to make the instrument advance further in the canal, or when resistance was encountered, the instrument was pulled out of the canal to clean the flutes.the canal was copiously irrigated with sodium hypochlorite. primary wave one filewas used in the same manner until it has reached 2/3 of the estimated working length as indicated by the stopper on the instrument. the instrument is then removed from the canal; the canal was irrigated. this procedure was repeated until the instrument reached original working length. group ii: the protaper retreatment instruments (d1, d2, d3) (dentsply, maillefer) of which the tapers and tip diameters were equivalent to size 0.09/0.30mm, 0.08/0.25mm, and 0.07/0.020mm respectively were used sequentiallyfor removing gutta-percha from each root canal in a crowndown technique each filewere used as recommended by manufacturer then apical enlargement was performed with finishing file f2. group iii: the r-endo instruments (r1, r2 and r3) (micro-mega, france) were used sequentially to remove gutta-percha and its sealer in abrushing circumferential movement as recommended bythe manufactures. the three instruments have the same tip size equivalent to no 25 but with different tapers; 0.08 for r1, 0.06 for r2, 0.04 for r3. r3 prepares the canal at 0.04 taper so the r2 file was used again to the full working length to establish the 0.06 taper. an hero shaper file no 25 (micro mega besancon, france) was used as a finishing file to the full length of the canal. group iv: the d – racere treatment instruments (dr1, dr2) (fkg dentaire, swiss dental products) of which the tapers and tip diameters were equivalent to size 10% iso 30, 4% iso 25 respectively were used sequentially in a crowndown technique for removing gutta-percha from each canal.finalapical enlargement was performed with race file size 25. removal of filling material was judged completed when no gutta-percha or sealer on the last instrument used andthe working length was reached. evaluation of effective gutta-percha removal: all the roots were radiographed before and after removal of gutta-percha from both buccolingual and mesiodistal directions using custom made platform and digital radiograph system rvg to have a digitized image. radiographic platform provided standardized position for periapical films, root blocks and x-ray cone. the source-film distance was adjusted to 18cm between xray source and the object and the exposure time was 0.12 sec. the total surface area of all root canals were measured before removal of gutta-percha (figure. 1) and the area of the remaining gutta-percha filling in the canals after retreatment procedure (figure 2) from both directions. these measurements were analyzed with adobe photoshop cs6 software and specific software tool (magnetic lasso)was used tooutline the total canal areaand the filling debris area(fig 3).the software was calibrated to convert pixels into actual millimeter units. a measurement scale was made to have area in mm2. the percentage of removed gutta-percha calculated by the following equations: area of removed gutta-percha= area of guttapercha before removal – area of remnant guttapercha after removal percent of gutta-percha removal=(area of removed gutta-percha/area of gutta-percha before removal)*100. figure 1: the use of adobe photoshop cs6 software and magnetic lasso tool to measure the total canal area. j bagh college dentistry vol. 28(1), march 2016 a comparison of restorative dentistry 60 figure 2: the use of adobe photoshop cs6 software and magnetic lasso tool to measure the area of the remaining filling debris area. figure 3: radiograph to trace remaining filling material in both bucco-lingual and mesio-distal directions by the use of magnetic lasso tool. results the present study showed the following results (table 1): in bucco-lingual direction, the highest and the lowest mean values for of the percentage of root canal filling removalwere seen at group i wave one system (79.90) and group iv d–race system (66.85) respectively. in mesiodistal direction, the highest and the lowest mean values for of the percentage of root canal filling removalwere seen at group i wave one system (76.74) and group ii protaper retreatment system (64.46) respectively.the rest mean values for the study groups were fluctuating between these values. to compare between the four retreatment systems anova test and the least significance difference test (lsd) were performed to evaluate the significant differences between each two retreatment system for their effectiveness in removal of root canal filling materialsthe results showed the following, in bucco-lingual direction (table 2): 1there were significant difference (p <0.05) between group i (wave one) and group ii (protaper retreatment), group iv (d – race). 2there was non-significant difference (p >0.05) between group i (wave one) and group iii (rendo). 3there were non significant difference (p >0.05) between group ii (protaper retreatment) and group iii (r-endo), group iv (d – race). 4there were non significant difference (p >0.05) between group iii (r-endo) and group iv (d – race). the results showed the following, in mesiodistal direction (table 2): 1there were significant difference (p <0.05) between group i (wave one) and group ii (protaper retreatment) , group iii (r-endo). 2there were non significant difference (p >0.05) between group i (wave one) and group iv (d – race). 3there were non significant difference (p >0.05) between group ii (protaper retreatment) and group iii (r-endo), group iv (d – race). 4there were non significant difference (p >0.05) between group iii (r-endo) and group iv (d – race). table 1: mean value and standard deviation of four retreatment techniques. studied groups n bucco-lingual (bl) mesiodistal (md) mean% +sd mean% +sd wave one 10 79.90 6.52 76.74 8.31 protaper retreatment 10 71.48 12.33 64.46 9.73 r-endo 10 74.01 11.82 66.46 11.32 d – race 10 66.85 14.75 67.75 14.85 discussion nonsurgical endodontic retreatment was aimed to remove the contaminated filling material and the remnants pulp tissue or bacteria that might because the previous treatment to fail (18). success rates of nonsurgical endodontic retreatment were ranged from 40% to100% (19). this variability might be related to different factors: the techniques that were used to remove the filling materials (20), the repairing possibility of pathologic or iatrogenic defects and the alterations in the natural course of the root j bagh college dentistry vol. 28(1), march 2016 a comparison of restorative dentistry 61 canals(21). removal of sealers and gutta-percha from table 2: the least significance difference test (lsd) of the percentage of root canal filling removal between the four retreatment techniques. studied groups (lsd test) buccolingual (bl) (lsd test) mesiodistal (md) pvalue sig. pvalue sig. wave one protaper .028 s .020 s r-endo .094 n.s .050 s d – race .024 s .084 n.s pro taper r-endo .579 n.s .694 n.s d – race .942 n.s .521 n.s r-endo d – race .530 n.s .802 n.s *s =significant*n.s= non significant inadequately filled root canal systems was essential in root canal retreatment as it was unlikely to uncover remaining necrotic tissue or bacteria that might be the cause for periapical inflammation and post treatment disease (22). a number of new endodontic materials hadbeen introduced in the last few years among them wasthe resin based sealer (23). despite the material wasacclaimed to have superior properties, regarding its adherence to the tooth structure, no obturation system yet claimedto have a 100% success rate and a number of reasons would necessitate the retreatment of filled teeth(24). the present study evaluated the effectiveness of retreatmenttechniquesinremoval of guttapercha and ah26 resin sealers. all specimens were obturated using lateral condensation technique to condense protaper gp point (f2), as it showedbetter treatment outcome (prevent bacterial penetration of the root canal) than single protaper gp point which wasinaccordance with study performed by yucel and ciftci in 2006. retreatment solvents were notused in this study because the combined use of solvents androtary files complicatedthe debridementof the root canal, the solvents dissolved flowed into and coated canal irregularities or penetrated into the peri-radicular tissues (25). previous studies suggested that further root canal refining is necessary afterusing retreatment systemsbecause of the apical diameter of the last instrument was designed to reach the working length, but it did not permit a complete cleaning action (26). in the present study finishing files were used at the end of the retreatment procedure forrotary instruments to properly enlarged the canal, f2, hero shaper file no 25 and race file size 25 as recommended by the manufactures. reciprocating systems were an interesting alternative for removal of root fillings in retreatment cases. however, few studies had investigated the efficiency of reciprocating systems for emptying filled root canals (27). the findings of the present study showed that the use of group i (wave one) with reciprocating motion was more efficient in removal of root canal filling materials in both bucco-lingual and mesiodistal direction of dentalradiographthese results might be attributed to that wave one file was used with reciprocating movement with unequal clockwise and counter clockwise rotation based on reverse balanced force technique (28). these reciprocating movements caused engagement of the filling material with the first motion and dislodgment of the filling from the canals via the second motion. the other retreatment systems used in the other groups with continuousrotation motion showed less efficiency in removing of root canal filling materials and these results vary according to difference in taper, design and cross section of each retreatment systems. different methodologies had been used for the evaluation of the remaining filling material, in this study radiographic examination with computers software which were more appropriate than other methods such as longitudinal cleavage of the root which might cause displacement of the filling debris that was to be evaluated, which would compromise the accuracy of the measurements(29). to overcome the limitation of the radiographic images that provided only two dimensional information, bucco-lingual and mesiodistal images were taken and evaluated for each root. this is in accordance with other studies (30). within the limitation of the present study remnants of filling material were observed in all samples regardless of the groups examined. rotaryretreatment instrumentsused with continuous motion were not as effective in removing filling material remnants as the reciprocating instrument. the reciprocating technique was most effective method for removing gutta-percha and sealer than continuousrotary technique. j bagh college dentistry vol. 28(1), march 2016 a comparison of restorative dentistry 62 references 1. stabholtz a, friedman s. endodontic retreatment case selection and technique. part 2: treatment planning for retreatment. j endod1988; 14: 607–14. 2. friedman s, stabholtz a, tamse a. endodontic retreatment case selection and technique. part 3: retreatment technique. j endod1990; 16: 543–6. 3. gorni fg, gagliani mm .the outcome of endodontic retreatment: a 2-yr follow-up. j endod 2004; 30:1–4. 4. betti lv, baramante cm. quantec sc.rotary instruments versus hand files for gutta-pecha removalin root canal retreatment. int endod j 2001; 34: 514-9. 5. giuliani v, cocchetti c, pagavino g. efficacy of protaper universal retreatment files in removing filling materials during retreatment. j endod 2008; 34: 13814. 6. baratto-filho f, ferreira el, fariniuk lf. efficiency of the 0.04 taper profile during the re-treatment of gutta-percha-filled root canals. int endod j 2002; 35:651-4. 7. sae-lim v, rajamanickam i, lim bk, lee hl. effectiveness of profile .04 taper rotary instruments in endodontic retreatment. j endod 2000; 26:100-104. 8. wilcox lr, krell kv, madison s, rittman b. endodonticretreatment: evaluation of gutta-percha and sealer removal andcanal reinstrumentation. j endod1987; 13: 453-7. 9. yared g .canal preparation using only one nitirotary instrument: preliminary observations. int endod j 2008; 41: 339–44 (ivsl). 10. kim hc, kwak sw, cheung gs, ko dh, chung sm, lee w. cyclic fatigue and torsional resistance of two new nickel-titanium instruments used in reciprocation motion: reciproc versus waveone. j endod 2002; 38: 541–4. 11. alves fr, rocas in, almeida bm, neves ma, zoffoli j, siqueira jf jr .quantitative molecular and culture analyses of bacterial elimination in oval-shaped root canals by a single-file instrumentation technique. int endod j 2012; 45: 871–7. 12. hulsmann m, bluhm v. efficacy, cleaning ability and safety of different rotary niti instruments in root canal retreatment. int endod j 2004; 37,468-76. 13. ferreria jj, rhodes js, pitt ford tr. the efficacy of guttapercha removal using profiles. int endod j 2001; 34:267-74. 14. masiero av, barletta fb. effectiveness of different techniques for removing gutta-percha during retreatment. int endod j 2005; 38, 2-7 15. de oliveira dp, barbizam jvb, trope m, teixeira fb. comparison between gutta-percha and resilon removal using two different techniques in endodontic retreatment. j endod 2006; 32:362–4. 16. giuliani v, coccbetti r, pagavino g. efficacy of protaper universal retreatment files in removing filling materials during root canal retreatment. j endod 2008; 34: 1381-4. 17. gergi r, sabbagh c. effictiveness of two nickel titanium rotary instruments and a hand files for removing guttapercha in severely curved root canals during retreatment :an ex vivo study. intendod j 2007; 40: 532-7. 18. saad ay, al-hadlaq sm, al-katheeri nh .efficacy of two rotary niti instruments in the removal of guttapercha during root canal retreatment. j endod 2007; 33: 38–41. 19. paik s, sechrist c, torabinejad m. levels of evidence for the outcome of endodontic retreatment. j endod 2004; 30:74550. 20. farzaneh m, abitol s, freidman s. treatment outcome inendodontics: the toronto study –phases i and ii: orthograde retreatment. j endod 2004; 30:627 33. 21. masiero av, barletta fb. effectiveness of different techniques for removing gutta-percha during retreatment. int endod j 2005; 38: 2-7. 22. schirmeister jf, hermanns p, meyer km, goetz f , hellwig e. detectability of residual epiphany and gutta-percha after root canal retreatment using a dental operating microscope andradiographs; an ex vivo study. int endod j 2006; 39: 558-65. 23. monticelli f, sword j, martin g, schuster gs, weller rn, ferrari m, pashley dh, tay fr. sealing properties of two contemporary single cone obturation system. int endod j 2007; 40,374-385. 24. yucel ac, ciftçi a. effects of different root canal obturation techniques on bacterial penetration. oral surg oral med oral pathol oral radiol endod j 2006; 102(4): e88-92. 25. horvath sd, altenburgur mj, naumann m, wolkewitz m, schirrmeister jf. cleanliness of dentinal tubules following gutta-percha with and without solvents: a scanning electron microscope study. int endod j 2009; 42:1032-8 (ivsl) . 26. huang x, ling j, gu l. quantitive evaluation of debris extruded apically by using protaper universal tulsa rotary system in endodontic retreatment. j endod 2008; 33: 1102-5. 27. masiero av, barletta fb. effectiveness of different techniques for removing gutta-percha during retreatment. int endod j 2005; 38(1): 2–7. 28. yvesblum j, machtou p. qualitative description of new preparation technique the balance force motion using endograph. j endod 2001; 27:503-07. 29. barletta fb, lagranha sb. analisiscomparativo in vitro de diferentestecnicas de desobturación de conductosradiculares. endodoncia 2002; 20:189–96. 30. gergi r, sabbagh c. effectiveness of two nickel titanium rotary instruments and a hand files for removing gutta-percha in severely curved root canals during retreatment :an ex vivo study. int endod j 2007; 40: 532-7. hayder f.doc j bagh college dentistry vol. 25(3), september 2013 gender differences pedodontics, orthodontics and preventive dentistry142 gender differences, facial profile and treatment need of malocclusion for a sample of al-muthanna governorate students aged 15 years hayder s. al-atabi, b.d.s., m.sc. (1) abstract background: survey of the occlusion in population groups usually include in their objections the academic assessment of occlusal feature, the planning resources for public health treatment programmers, the comparison of different population and the screening of groups for orthodontic treatment. likewise a thorough investigation of the occurrence of malocclusions among school–students would be of major importance in the planning of orthodontic treatment in the public dental health services. for this purpose it is necessary to have detailed information on the prevalence of individual malocclusion among boys and girls at different ages distributed regionally, and moreover, an analysis of the need for orthodontic treatment in the different school classes. materials and methods: this study was conducted from 20th october 2011 to 9th may 2013 on (3424 ) students (1712 males and 1712 females); from which 62 students (1.8%) were excluded because of incomplete information (no molar relation can be attended) giving a valid sample of 3362 (1681 males and 1681 females) aged (15) years old were studied with respect to facial profile ,sagittal occlusion according to angle's classification, overjet, overbite, anterior crossbite , posterior crossbite, scissorsbite, rotation and displacement spacing and crowding. results: the normal profile were presented in (73.76%) students (74%) males and (73.53%) females. convex profiles were presented (20.34%) students (20.46%) males and (20.23%) females. a concave profile were presented in (5.9%) students (5.54%) males and (6.24%) females), the malocclusion were presented (73.05%) students (73.46%) males and (72.64%) females, according to the dental health component of index of the orthodontic treatment subjects with no need for treatment were about 44.11% , the subjects who need little treatment were about 26.82%, 13.06% of the subjects who need moderate treatment, 10.03% great treatment need and about 5.98% very greatly treatment need. conclusions: orthodontic treatment need according to iotn shows that there was no significant difference between males and females in the malocclusion, facial profile and treatment need. key words: malocclusion, facial profile, treatment need. (j bagh coll dentistry 2013; 25(3):142-148). introduction al-muthanna governorate lies 280km to the south of baghdad, itself part of middle furat of iraq. it is bounded on the north by diwaneya, on the west by saudi arabia, on the south by nasiriya and on the east by meesan. a thorough investigation of the occurrence of malocclusions among schoolchildren would be of major importance in the planning of orthodontic treatment in the public dental health service. for this purpose it is necessary to have available detailed information on the prevalence of individual malocclusions among boys and girls at different ages distributed regionally, and moreover, an analysis of the need for orthodontic treatment in the different school classes. an analysis of such data collected from large of children would throw light on the relationship between different types of malocclusion, widen our knowledge of their etiology and hence increase the possibility of preventing them. it is likewise important to carry out a comparison of the prevalence of malocclusion with different racial groups on an objective basis, since the information they would provide might well throw light on the causes of malocclusion(1). (1) assistant lecturer. college of medicine. university of almuthanna. malocclusion is endemic and wide spread throughout the world however its prevalence varies widely in different communities; knowledge of the nature of malocclusion feature is an essential step for planning orthodontic services on community(2).since malocclusion affects a large number of the population, it is by definition a public health problem and as any other phase of public health work, it is essential to have accurate information on the prevalence and incidence of the condition as up to date prevalence figures obtained from studies vary greatly and epidemiologic studies of the incidence of malocclusion in particular population date back to early 1900s (3). in various populations, malocclusion was examined by using the index of orthodontic treatment need (iotn) and the reproducibility of iotn was examined and the values indicated substantial agreement (4-6). several occlusal indices have been developed over the years in order to help professionals to objectively categorize malocclusion severity and to provide criteria indicating which patients should have treatment priority, mainly in those places where this treatment is unevenly spread. among these indices, the index of orthodontic treatment need (iotn) consists of two separate components which can be used for assessing j bagh college dentistry vol. 25(3), september 2013 gender differences pedodontics, orthodontics and preventive dentistry143 dental and functional health (dental health component-dhc) as well as aesthetic impairment due to malocclusion (aesthetic component-ac) (7). materials and methods the sample the sample consists of 15-year-old students attending third year intermediate schools. age was considered according to the last birthday giving an age range from 15 years 0 months to 15 years 11 months (8). the total number of students attending third year intermediate schools in al-muthanna governorate were (21680) and number of intermediate schools were ( 66 ), while the number of population were (700000) (ministry of education, al-muthanna directorate 2013). the minimum number of the sample to be representing is taken according to the following equation (9 ):(the number of sample= number of student / number of population × 100000 ) =21680 / 700000 × 100000= 3097 the sample has been taken from (32) intermediate schools, which were randomly selected in al-muthanna governorate. the subjects were chosen from different parts of the governorate, from urban and rural part ( alsammawa, alrumaitha, alkhuder and alsalman). the sample consist of (3424) students (1712 males and 1712 females); from which 62 students (1.8%) were excluded because of incomplete information (no molar relation can be attended) giving a valid sample of 3362 (1681 males and 1681 females). the sample was taken in terms of the following criteria: 1. no missing permanent teeth. 1. no previous orthodontic treatment. 2. no partially erupted and tipped teeth. 3. no severe facial disfigurement due to trauma, pathology or congenital. 4. no submerged deciduous teeth. 5. no supplemental teeth. permission was obtained from the almuthanna directorate of education. the schools` authorities were contacted and the purpose of the study was explained to them to assure full cooperation. methods of examination the examinations were carried out in rooms that were available in host school. the subjects were seated on ordinary chairs. the subject’s head was supported in an upright position and the examiner standing in front of the chair (10). the following instruments were used: plane mouth mirrors (no.4) dentaurum (042-751), soft stainless steel wire (0.5mm),tweezers ,kidney dish, millimeter graded vernier (inox, zurcher modell, an instrument designed to measure tooth rotation and displacement modified from van kirk and pennell and björk et al (11,1). it is 6.5 cm long and consist of two stainless steel rods of 1mm in diameter with rounded ends and 15 degree angle between them ( figure,1), indelible pencil, concentrated sterilization solution (ethyl alcohol 95%) and portable light. figure 1. instrument to measure tooth rotation and displacement orthodontic methods facial profile this step requires placing the patient in the physiologic natural head position, the head position of the individual adopts in the absence of others. this can be done with the patient either sitting upright or standing, but not reclining in a dental chair, and looking at the horizon or a distant object. with the head in this position, note the relationship between two lines, one dropped from the bridge of the nose to the base of the upper lip, and a second one extending from that point downward to the chin. each line segments should form a nearly straight line. an angle between them indicates either profile convexity (upper jaw prominent relative to chin) or profile concavity (upper jaw behind chin) as shown in (figure, 2). a convex profile therefore indicates a skeletal class ii jaw relationship, whereas a concave profile indicates a skeletal class iii jaw relationship (12). figure 2. facial profile sagittal occlusion depending on angle’s classification (13), the criteria described by lavelle (14) and described by houston (15) this variable was divided as follows (figure 3) : (a) normal molar occlusion (class ι). it is registered when the mesiobuccal cusp of the upper first permanent molar occludes with the j bagh college dentistry vol. 25(3), september 2013 gender differences pedodontics, orthodontics and preventive dentistry144 anterior buccal groove of the lower first permanent molar. (b) distal molar occlusion (class ιι). it is observed when the relative position of mandibular molar has shifted distally by half cusp width or more. (c)mesial molar occlusion (class ιιι).it is observed when the relative position of the mandibular molar had shifted mesially by half a cusp width or more. in addition to that cusp to cusp relationship of molars. figure 3. angle’s classification overjet (o.j) measurement of the horizontal relation of the incisors is made with the aid of millimeter graded veriner while the subject is in centric occlusion and measured the distance from the most prominent surface of labial surface of upper central incisor and labial surface of lower central incisor (figure,4a).the measurement of overjet is recorded to the nearest millimeter. increased overjet was considered as > 4mm and decreased overjet was considered as <1 mm. an increased, decreased, or reversed overjet value was considered as a single occlusal anomaly (10). overbite (o.b) the overbite was measured according to draker (16) while the subject is in centric occlusion with his occlusal plane horizontal. the amount of vertical overlap of the upper incisor on the lower incisor is marked with the pencil on the labial surface of the lower incisor using the incisal edge of the upper incisor to guide the pencil with the conical plane of the sharpened point of the pencil itself parallel to the subject's occlusal plane (figure,4b). if there is lack of vertical overlap between any of the opposing pairs of incisors (openbite), the amount of openbite is measured directly and recorded to the nearest whole millimeter. increased overbite was considered as >4mm and decreased overbite as < 1mm. an increased or decreased overbite including anterior openbite was considered as a single occlusal anomaly. figure 4a. overjet figure 4b. overbite crossbite and scissorbite anterior crossbite was recorded according to bjork (1) in which one, two or three of the upper incisors occlude lingual to the lowers. the measurement of the transverse lateral segment relation was made by direct inspection of the lateral segments on each side. one of three separate relations was recorded for the transverse interdigitation of the lateral segments (10) : crossbite: a buccal cusp of a mandibular tooth lied buccal to the maximum height of a buccal cusp of an opposing maxillary tooth. scissors bite : a buccal cusp of a mandibular tooth lied lingual to the maximum height of a lingual cusp of an opposing maxillary tooth (figure,5). crossbite normal scissorsbite figure 5. posterior crossbite and scissorbite (b=buccal, l=lingual, p=palatal) rotation and displacement fully erupted teeth that were rotated more than 15º (figure, 6a) were registered under ‘mesial’ or ‘distal’ rotation. the degree of rotation was measured with the registration instrument shown in (figure,1)(1) .any tooth displaced bodily from the ideal arch line by more than 1mm was registered under ‘buccal’ or‘palatal’ displacement (figure,6b). (11) figure 6a. rotation. figure 6b. displacement. spacing and crowding spacing (excessive arch space) existed, the vernier was used to measure the amount of space discrepancy and it was also recorded. later, in statistical analysis each segment was regarded as spaced where there was a shortage of 2mm or more of space beyond that required for the correct alignment of all teeth in that segment. while crowding (insufficient arch space) existed, a segment was regarded as crowded where there j bagh college dentistry vol. 25(3), september 2013 gender differences pedodontics, orthodontics and preventive dentistry145 was a shortage of 2mm or more of space preventing the correct alignment of all teeth in that segment (1,10) ( figure, 7). figure 7. spacing figure 7. crowding treatment needs assessment: the treatment need depends on the dental health component of the index of orthodontic treatment need (1987) (17). so the criteria of the assessment as follow: grade 1 (no treatment need ) extremely minor malocclusion, include displacement less than 1mm. grade 2 (little) 2a increased overjet greater than 3.5mm but less than or equal to 6mm with competent lips. 2b reverse overjet greater than 0mm but less than or equal to 1mm. 2c anterior or posterior crossbite with less than or equal to 1mm discrepancy between retruded contact position and intercuspal position. 2d displacement of the teeth greater than or equal to 2mm. 2e anterior or posterior openbite greater than 1mm but less than or equal to 2mm. 2f increased overbite greater than or equal to 3.5mm without gingival contact. 2g prenormal or postnormal occlusions with no other anomalies. include up to half a unit discrepancy. grade 3 (moderate )borderline need 3a increased overjet greater than 3.5 mm but less than or equal to 6mm with incompetent lips. 3b reverse overjet greater than 1mm but less than or equal to 3.5 mm. 3c anterior or posterior crossbite with greater than 1mm but less than or equal to 2mm discrepancy between retruded contact position and intercuspal position. 3e lateral or anterior openbite greater than 2mm but less than or equal to 4mm. 3f increased or complete overbite without gingival or palatal trauma. grade 4 (great ) treatment require 4a increased overjet greater than 6 mm but less than or equal to 9mm. 4b reverse overjet greater than 3.5mm with no masticatory or speech difficulties. 4c anterior or posterior crossbite with greater than 2mm between retruded contact position and intercuspal position. 4d sever displacement of teeth greater than 4mm. 4e extreme lateral or anterior openbite greater than 4mm. 4f increased or complete overbite with gingival or palatal trauma. 4h less extensive hypodontia requiring pre-restorative orthodontics or orthodontic space closure to obviate the need for a prosthesis. 4i posterior lingual crossbite with no functional occlusion contact in one or both buccal segment . 4m reverse overjet greater than 1mm but less than 3.5 mm with recorded masticatory and speech difficulties .4t partially erupted teeth, tipped and impacted against adjacent teeth 4x supplemental teeth. grade 5 (very great) 5a increased overjet greater than 9mm. 5h extensive hypodontia with restorative implication. 5i impeded eruption of teeth. 5m reverse overjet greater than 3.5mm with recorded masticatory and speech difficulties. 5p defect of cleft lip and palate.5s submerged deciduous teeth. statistical analysis the data were processed and analyzed by using the statistics package for social sciences (spss inc., version 17 for windows 7and excel 2010).the usual statistical methods were used in order to analyze and assess results include:descriptive statistics, inferential statistics, z-test for comparison significant difference between two proportions. the following levels of significance are used: p ≤ 0.05 significant. results 1distribution of facial profile and gender differences as shown in (table, 1 and figure, 8): the normal profile were presented in 2480 (73.76%) students (1244 (74%) males and 1236 (73.53%) females). a convex profile was presented in 684 (20.34%) students (344 (20.46%) males and 340 (20.23%) females). a concave profile were presented in 198 (5.9%) students (93(5.54%) males and 105(6.24%) females),there was no significant differences between both gender for all types of facial profile ( p>0.05). table 1. distribution (%) of profile and gender differences pr= profile, no= normal, cx=convex, cv=concave. pr. total male female p sig no % no % no % no 2480 73.76 1244 74 1236 73.53 0.373 (ns) cx 684 20.34 344 20.46 340 20.23 0.431 (ns) cv 198 5.9 93 5.54 105 6.24 0.184 (ns) t 3362 100 1681 100 1681 100 -- j bagh college dentistry vol. 25(3), september 2013 gender differences pedodontics, orthodontics and preventive dentistry146 figure 8. distribution (%) of profile and gender differences pr= profile, no= normal, cx=convex, cv=concave. 2distribution of malocclusion (any anomaly in sagittal occlusion, overjet, overbite, anterior crossbite , posterior crossbite ,scissorsbite, rotation and displacement spacing and crowding) and gender differences as shown in (table ,2 and figure ,9) :the malocclusion were presented in 2456 (73.05%) students (1235(73.46%) males and 1221 (72.64%) females) while there was no any anomaly in 906 (26.95%) students (446(26.54%) males and 460 (27.36%) females). there was no significant differences between both gender ( p>0.05). table 2. distribution (%) of malocclusion and gender differences, p= present, a = absent. m total male female p sig no % no % no % p 2456 73.05 1235 73.46 1221 72.64 0.281 ns a 906 26.95 446 26.54 460 27.36 0.288 ns t 3362 100 1681 100 1681 100 - figure 9. distribution (%) of malocclusion and gender differences, p= present, a = absent. 3distribution of the treatment need and gender differences as shown in (table 3 and figure 10): the grade 1 (no treatment need) were presented in 1483 (44.11%) students (739(43.96%) males and 744 (44.25%) females), grade 2 (little treatment need) were presented in 902 (26.82%) students (449(26.71%) males and 453 (26.94%) females), grade 3 (moderate treatment need) were presented in 439 (13.06%) students (221(13.15%) males and 218 (12.97%) females), grade 4 (great treatment need) were presented in 337 (10.03%) students (165(9.82%) males and 172 (10.24%) females), grade 5(very great treatment need) were presented in 201 (5.98%) students (107(6.36%) males and 94 (5.6%) females), there was no significant differences between both gender for all types of treatment need (p>0.05). table 3. distribution (%) of iotn and gender differences g1= grade 1, g2 = grade 2, g3= grade 3,g4= grade 4,g5= grade 5 iotn total male female p sig no % no % no % g1 1483 44.11 739 43.96 744 44.25 0.43 ns g2 902 26.82 449 26.71 453 26.94 0.437 ns g3 439 13.06 221 13.15 218 12.97 436 ns g4 337 10.03 165 9.82 172 10.24 0.336 ns g5 201 5.98 107 6.36 94 5.6 0.165 ns t 3362 100 1681 100 1681 100 -- figure 10. distribution (%) of iotn and gender differences g1= grade 1, g2 = grade 2,g3= grade 3,g4= grade 4,g5= grade 5 discussion the three types of facial profile showed no significant relation with gender: normal profile was presented in (73.76%) students (74%) males and (73.53%) females. convex profile was presented (20.34%) students (20.46%) males and (20.23%) females. concave profile was presented in (5.9%) students (5.54%) males and (6.24%) females) which is similar to krogman (18), telle (19), helm (20), on other hand, it is higher than aldialaimi (21) and al-taee (22). this difference may be due to race and variation in environmental factors in addition to age group and this can be explained according to lines (23) and bell et al (24) who reported that the patient with straight profile usually have normal occlusion or class i malocclusion, those with convex profile having an increase in the probability of having a class ii malocclusion associated with retrusive mandible or a protrusive maxilla or both. patient with concave profile having an increase in the probability of having a class iii malocclusion associated with j bagh college dentistry vol. 25(3), september 2013 gender differences pedodontics, orthodontics and preventive dentistry147 retruded maxilla, protruded mandible or both. the prevalence of malocclusion (any anomaly in sagittal occlusion, overjet, overbite, anterior crossbite, posterior crossbite, scissorsbite, rotation and displacement spacing and crowding) showed no significant relation with gender: the malocclusion were presented (73.05%) students (73.46%) males and (72.64%) females, while there was no any anomaly in (26.95%) students (26.54%) males and (27.36%) females. which was much lower than those found by cons (25), abdulla (26), batayine (27); but was near to the findings of kinaan (2), al-huwaizi (28) and rasheed (29) and higher than that of corruccini and lee (30) among chinese. this due to difference in ethnic and age group or could be due to skeletal, dental, soft tissue factors and downward direction of mandibular growth. according to the dental health component of index of the orthodontic treatment need (iotn), the five grades of (iotn) showed no significant relation with gender, the subjects with no need for treatment were about 44.11% table (3) which is more than that found by van kirk & pennell (11), ingervall et al. (31), myrberg &thilander (32) and johnson & harkness (33) and al-taee (22). this difference is due to difference in the prevalence of malocclusion among the different ethnic and age group. according to (iotn), the subjects who need little treatment were about 26.82%, 13.06% of the subjects who need moderate treatment, 10.03% great treatment need and about 5.98% very greatly treatment need. references 1. björk a, krebs åa, solow b. a method for epidemiological registration of malocclusion. acta odontol scand 1964; 22: 27-41 2. kinaan bk. the problem of malocclusion in iraq. iraqi dent j 1982; 9: 24-28. 3. garner l.d, butt m.h. malocclusion in black americans and nyeri kenyans, and epidemiological study. angle orthod 1985; 55(2):139-46. (ivsl) 4. brook ph, shaw wc. the development of orthodontic priority index. eur j orthod 1989; 11: 309-20. 5. burden dj, holmes a. the need for orthodontic treatment in the child population of the united kingdom. eur j orthod 1994; 16(5): 395-9. 6. burden dj, mitropoulos cm, shaw wc. residual orthodontic treatment need in a sample of 15and 16year-olds. br dent j 1994; 176(6): 220-4. 7. dean ja, mcdonald sm, walker po. public assistance orthodontic treatment needs: a report from the state of indiana. j public health dent 2005; 65(3): 133-7. 8. world health organization. oral health surveys: basic methods. 4th ed. geneva: who, the organization; 1997. 9. wayne wd. biostatistics. a foundation for analysis in the health sciences, 2nd ed. new work: 1976. 10. baume l, horowitz hs and freer tj. a method for measuring occlusal triats. inter j dent 1973; 23 (3): 530-7. 11. van kirk le, pennell eh. assessment of malocclusion in population groups. am j orthod 1959; 45(10): 75258. 12. proffit wr, field hw, sarver dm. contemporary orthodontics. 4th ed. st louis: mosby year book; 2007. 13. angle eh. classification of malocclusion. dental cosmos 1899; 4: 248-64. 14. lavelle clb. a study of multiracial malocclusion. community dent epidemiol 1976; 4: 38-41. 15. houston wjb, stephens cd, tulley wj. a textbook of orthodontics. great britain: wright; 1982. p. 113. 16. draker hl .handicapping labiongual deviations: a proposed index for public health purposes am j orthod 1960; 4694: 295-305. 17. brook ph, shaw wc. the development of orthodontic priority index. eur j orthod 1989; 11: 309-20. 18. krogman wm. the problem of timing in facial growth, with special reference to the period of the changing dentition. am j orthod 1951; 37: 253. 19. telle es. study of the frequency of malocclusion in the county of hedmark, norway: a preliminary report. trans eur orthod soc 1951: 192-8. 20. helm s. malocclusion in danish children epidemiologic study. am j orthod 1968; 54(5): 393400. 21. al-dailaimi m. occlusal feature in sample of yemeni students aged (10-15) year. m.sc. thesis, college of dentistry, baghdad university, 2000. 22. al-taee zh. occlusal features and treatment need for a sample of 9-11 years old students from ramadi city. m.sc. thesis, college of dentistry, baghdad university, 2004. 23. lines pa. profile orientric and facial esthetics. am j orthod 1978; 73: 64857. 24. bell yvh, proffit wr, white rp. surgical correction of dentofacial deformities. vol. 1. philadelphia, pa., w.b. saunders co.; 1980; p. 111. 25. cons nc, mruthyunjaya yc, pollard st. distribution of occlusal traits in a sample of 1337 children aged 15-18 residing in upstate new york. int dent j 1978; 28(2): 154-64. 26. abdulla nm. occlusal features and perception: a sample of (13-17) years old adolescent. m.sc. thesis college of dentistry, baghdad university, 1996. 27. batayine fam. occlusal features and perception of occlusion of jordanian adolescents: (a comparative study with an iraqi sample). m.sc. thesis, college of dentistry, baghdad university, 1997. 28. al-huwaizi af. occlusal feature, perception of occlusion, orthodontic treatment need and demand in 13 years old iraqi student. ph.d. thesis, college of dentistry, baghdad university, 2002. 29. rasheed ta. occlusal features and treatment need among 13 year old kurdish students in sulaimania. m.sc. thesis, college of dentistry, university of sulaimania, 2006. j bagh college dentistry vol. 25(3), september 2013 gender differences pedodontics, orthodontics and preventive dentistry148 30. corruccini rs, lee gtr. occlusal variations in chinese immigrants to the united kingdom and their off spring. arch oral biol 1984; 29(10): 779-82. 31. ingervall b, seeman l, thilander b. frequency of malocclusion and need of orthodontic treatment in 10-year-old children in gothenburg. swed dent j 1972; 65: 7-21. 32. myrberg n, thilander b. orthodontic need of treatment in swedish schoolchildren from objective and subjective aspects. scand j dent res 1973; 81: 85-91. 33. johnson m, harkness m. prevalence of malocclusion and orthodontic treatment need in 10-year-old new zealand children. aust orthod j 2000; 16(1):1-8. haween f.docx j bagh college dentistry vol. 28(2), june 2016 effect of periodontal oral and maxillofacial surgery and periodontics 73 effect of periodontal therapy on serum and salivary interleukin-2 levels in chronic periodontitis haween t. nanakaly, b.sc., m.sc., ph.d. (1) abstract background: interleukine-2 is a multifunctional cytokine, considered a central regulator of host resistance against a variety of pathogens and has been recently demonstrated to exert an active role in the pathogenesis of periodontal diseases. the purpose of this study was to evaluate the effect of scaling and root planning on level of il-2 in serum and saliva of patients with chronic generalized periodontitis, in relation to clinical parameters. materials and methods: a total of 50 subjects were enrolled, of which 25 had chronic generalized periodontitis and 25 periodontally healthy subjects as control. the clinical parameters included: gingival index, pocket probing depth, clinical attachment level and bleeding on probing. the level of il-2 in serum and saliva was estimated by using enzyme linked immunosorbent assay kit at baseline and after 4 weeks of the treatment (scaling and root planning). results: mean il-2 level in serum and saliva of patients with chronic periodontitis at baseline(382.15± 96.02 and 501.82± 88.08 ng/l) were significantly higher than in controls (10.98± 3.04 and 20.89 ± 7.16 ng/l; p=0.001) respectively. post-periodontal therapy, il-2 levels in serum and saliva increased significantly (534.18 ± 127.70 and 710.87 ± 198.15; p= 0.001.) compared to basal levels, as well as to control group (p< 0.001). statistically significant positive association was found between salivary il-2 level and the pocket depth in the chronic periodontitis post therapy (r = 0.45, p= 0.02). conclusion: short-term nonsurgical periodontal therapy leads to in a significant improvement in clinical periodontal parameters and a marked increase in il-2 levels keywords: non-surgical periodontal therapy, chronic periodontitis, serum, saliva, interleukine-2. (j bagh coll dentistry 2016; 28(2):73-78). introduction periodontal disease (pd) is an inflammatory disease, is also considered as an immunological disease as localized chronic inflammation associated with gingiva exhibits distinctive immunologic features which include elevated cellular and humoral immune responses (1). it results from an interaction of the host defence mechanism with microorganisms in biofilm accumulating on the teeth surface, consequences in progressive destruction of periodontal tissues and alveolar bone, with formation of periodontal pockets and gingival recession, leading to tooth loss (2,3). cytokines are water-soluble glycoproteins that are secreted by various cells in the body, usually in response to an activating stimulus and induced responses through binding to specific receptors. their primary role is intercellular signaling that act as intracellular regulatory factors at both local and systemic level. they are central to the pathogenesis of an ever-increasing number of diseases, including periodontal disease (4) cytokines have a key role in the function and differentiation of t cells, and they designate the t-helper subsets to amplify or control the amplitude of the inflammation and the destruction related to inflammation (5). the macrophages and t cells are dominated in the early/stable lesions of chronic periodontitis (cp), leading to the respect that this response is developed by the th1 cyto (1)lecturer. department of basic sciences, college of dentistry, hawler medical university. ph.d. (clinical immunology) kines. while, in the advanced/ progressive lesions of cp, b cells and plasma cells are dominate and th2 cytokines (6,7) . in diseased states, cytokines may be secreted not only by resident cells but also by locally infiltrated immune-competent cells (8). the balance between th1 and th2 cells phenotypes determines the successful resolution of inflammation. the th1 response is maintained by interleukin-2 (il-2) and interferon-gamma (ifn-γ), which inhibits th2 response (9). contributing inflammatory mediators and tissue destructive molecules have been detected in the gingival tissues, gingival crevicular fluid (gcf), saliva and serum of patients affected by periodontitis. qualitative and quantitative changes in the composition of these biomarkers could have diagnostic and therapeutic significance. furthermore, periodontal therapy reinforces the immune response and leads to the recovery of inflammation by reducing the level of inflammatory mediators in serum, saliva and gcf with significance difference (10). interleukin-2 (il-2), is a pro-inflammatory cytokine derived from t-helper 1 cells in response to antigenic stimuli. il-2 regulates a series of processes in different cells of the immune system including; acts as a t cell growth factor, bcell activation and the stimulation of immunoglobulin (ig) secretion by b-lymphocytes, stimulates monocytes/macrophages, promotes proliferation and differentiation of natural killer cells (nk) cells to increase their cytolytic functions, is also essential for the development of th1, th2, treg, and th17 differentiation and osteoclast activity j bagh college dentistry vol. 28(2), june 2016 effect of periodontal oral and maxillofacial surgery and periodontics 74 (11). il-2 has been also implicated in the stimulation of osteoclast activity in bone resorption, and it has been suggested that il-2 plays an active role in the pathogenesis of periodontal diseases (12). it is recognized that the metabolic products of periodontopathic bacteria decrease cytokine production including il-2 (13). furthermore, serum levels of il-2 in patients with chronic periodontitis were higher than in healthy controls (14) suggesting that an elevated serum il2 level in untreated chronic periodontitis has the potential to be a biomarker for periodontal tissue destruction. recent evidence has suggested that il-2 responses to periodontal pathogens decreased from the mononuclear cells in periodontitis patients (15).it is preferred to determine whether non-surgical periodontal therapy can change the levels of these markers, so that a novel link between periodontal disease and other systemic inflammatory diseases can be explored. thus, the aim of this study was to compare serum and salivary level of il-2 between healthy subjects and patients with chronic periodontitis, to determine whether the levels of il-2 changed after one month of non-surgical periodontal therapy (scaling and root planning, srp), and to analyse the correlation between serum and salivary il-2 levels with clinical periodontal parameters. materials and methods study groups the present prospective cohort trail was conducted at the clinic of periodontology and microbiology laboratory of the college of dentistry, hawler medical university from mid november 2014 to may 2015. the study protocol was approved by the ethical committee of college of dentistry/ hawler medical university. written informed consent was obtained from all patients for their participation in the study. this study included 50 participants: 25 patients suffering from a severe generalized chronic periodontitis (30 to 45 years; 13 females and 12 males) and 25 periodontally healthy controls (3042 years; 14 females and 11 males). clinical history was recorded for all thestudy group (personal data and medical history). each subjects had at least 20 standing teeth, periodontitis patients with at least five teeth with sites probing 5mm or deeper and radiographic of alveolar bone loss for screening purposes or presented a sever (loss of supporting bone ≥ 1/3 of root length), generalized (≥ 30% affected sites) periodontal disease. the control group enclosed individuals without any history of periodontal disease and attachment loss, as well as with probing pocket depth (pd) ≤ 3 mm and with bleeding index (pbi) simplified < 20% to exclude the presence of gingivitis. subjects had received no previous periodontal treatment, antimicrobial therapy or periodontal surgery in the preceding six months, subjects with systemic diseases, tumors, pregnancy, lactating mothers, alcoholism and smokers were excluded. generalized chronic periodontitis was diagnosed according to the criteria accepted by the american academy of periodontology (16). sample collection and analysis all the samples, prior to and after periodontal therapy were collected between 8:00-11:00 a.m. participants were requested to refrain from eating, drinking (except water), chewing gum, brushing their teeth and using mouth rinsing within at least 2 hours prior to saliva collection to exclude any possible influences. subjects were asked to rinse their mouth with distilled water thoroughly to remove any food debris, following which they expectorated at least 3 ml of un-stimulated whole saliva into a 5ml sterile tubes before periodontal examination according to the method described by navazesh (17). collected samples were placed on ice pack immediately, then transported to the laboratory andcentrifuged at 3500 rpm for 10 minutes. the supernatant was kept frozen at -40 º c as aliquots until assayed. a total of 3 ml of blood was drawn from antecubital fossa by vein puncture of all participants at baseline and 1 month after periodontal treatment using a 5cc syringe. blood was transferred to an appropriately labelled sterile plain tube. samples were allowed to clot for 1 hour at room temperature, and sera were separated from blood cells by centrifuging at 3000 rpm for 5 minutes. the extracted serum was immediately transferred to a plastic vial and stored at -40 º c until the time of assay(18).serum and salivary il-2 levels were measured with an elisa kit using human interleukine-2(il-2) provided by my biosource international inc., usa (catalog # mbs164623)] according to manufacturer's instructions. the standard range was 52000 ng/l with a sensitivity of 2.51ng/l. clinical parameters clinical measurements and radiographic examinations of all participants were performed by a single experienced examiner after collection of serum and saliva samples. periodontal evaluation included gingival index (gi), probing pocket depth (ppd), clinical attachment level (cal) and bleeding on probing (bop) using j bagh college dentistry vol. 28(2), june 2016 effect of periodontal oral and maxillofacial surgery and periodontics 75 unc 15 probe were measured at six sites per tooth. treatment following sampling, the patients received nonsurgical periodontal treatment which comprised instruction about oral hygiene and full-mouth scaling and root planning. the clinical parameters were re-evaluated one month after completion of non-surgical treatment and second serum and saliva samples were re-sampled. the study group before phase i therapy was called the bt group, and the same group after completion of 1 month of therapy was called the at group. subjects in the control group received no periodontal treatment during the study statistical analysis the data were analysed using a spss 21 (statistical package for the social sciences). mean and standard deviation (mean ± sd) are calculated for all the parameters (il-2, gi, ppd, cal, bop) of both subgroups of the test group (at baseline and after 4 weeks of therapy) and control group. tukey’s multiple comparison test was performed to determine the difference of serum and salivary il-2 levels between the groups. correlations between il-2 levels and clinical parameters were assessed by spearman correlation coefficient analysis. a p-value of p<0.05 was considered statistically significant. results subject variables are listed in table 1; it showed mean value, standard deviation of age, gi, ppd, cal, bop, and il-2 in serum and saliva of study and control groups. demonstrable levels of il-2 were found in all serum and saliva samples of study and control groups. the mean values of serum il-2 levels in patients with chronic periodontitis (bt and at) and in controls were (382.15± 96.02, 534.18± 127.70, and 10.98± 3.04 ng/l) respectively. for mean values of salivary il-2 in patients cp (bt and at) and in controls were (501.82± 88.08, 710.87± 198.15, and20.89± 7.16 ng/l) respectively. il-2 levels in both serum and saliva in patients with cp increased significantly ( p= 0.01, p=0.001) after periodontal therapy, and significantly higher at baseline values than controls (p < 0.01, p < 0.001) (table 2). by spearman correlation coefficient analysis, showed that there was a significant positive correlation between the increase of salivary il-2 level with the reduction of ppd after non-surgical periodontal therapy in treatment group (r=0.448, p= 0.025). however, no significant relation of serum and salivary il-2 levels with other clinical parameters including gi, cal as shown in (table 3). table 1: the descriptive statistics (mean± sd) for age, gi, bop, ppd, cal, serum and salivary il-2 levels in control and study group before and after non-surgical periodontal therapy parameters chronic periodontitis (n=25) control (n=25) before therapy (mean ± sd) after therapy (mean ± sd) (mean ± sd) age (years) 38.44 ± 3.59 38.44 ± 3.59 35.72 ± 3.48 gi 2.56± 0.51 1.40± 0.50 1.24± 0.44 ppd 4.73± 0.62 3.12± 0.70 2.40± 0.65 cal 4.30± 0.56 1.93± 0.44 0.00± 0.00 bop 48.63± 17.22 11.63± 10.58 0.00± 0.00 serum il-2(ng/l) 382.15± 96.02 534.18± 127.70 10.98± 3.04 saliva il-2(ng/l) 501.82± 88.08 710.87± 198.15 20.89± 7.16 data are presented as mean ± standard deviation; gi= gingival index; bop=bleeding on probing; cal= clinical attachment level; ppd=probing pocket depth; il-2= interleukin-2. table 2: multiple comparison of serum and salivary il-2 levels between the groups by tukey's test dependent variable groups mean difference (mean ±sd ) t-test p-value il-2 (ng/l) serum bt v c 371.17± 97.01 19.13 0.00** at v c 523.20± 128.67 20.33 0.00** bt v at -152.04± 133.04 -5.71 0.00** il-2 (ng/l) saliva bt v c 480.93± 89.97 26.73 0.00** at v c 689.99± 198.77 17.36 0.00** bt v at -209.05± 215.90 -4.84 0.00** bt; before therapy; at= after therapy, c=control; ** paired sample ttest: p < 0.001, highly significant. j bagh college dentistry vol. 28(2), june 2016 effect of periodontal oral and maxillofacial surgery and periodontics 76 table 3: correlation coefficient between clinical parameters and serum il-2 levels in both serum and saliva (spearman correlation coefficient) group clinical parameter interleukin-2 (serum) interleukin-2 (saliva) before therapy n=25 r p-value r p-value gi 0.02 0.94 -0.13 0.52 ppd 0.03 0.87 -0.03 0.87 cal 0.38 0.06 0.25 0.24 bop 0.29 0.16 0.24 0.25 after therapy n=25 gi 0.06 0.78 -0.02 0.94 ppd -0.16 0.45 0.45 0.02** cal 0.23 0.26 0.15 0.49 bop -0.32 0.12 -0.03 0.89 control n=25 gi 0.04 0.85 0.17 0.42 ppd -0.27 0.20 0.06 0.79 cal ------------ bop ----------- r=spearman rank correlation coefficient discussion the data from present study revealed that a higher level of il-2 was expressed in serum and saliva in cp subjects at baseline than in healthy individuals (p< 0.01), as was a significant increase observed in cp subjects post treatment (at) in comparison with the control expression (p< 0.01). the concentration of il-2 in the saliva was found to be greater than serum in all groups. this may be due to localized secretion of the il-2 from the cells of periodontal tissue in response to inflammation. the present study also demonstrated that the increase of salivary il-2 level correlated significantly with the decrease of ppd, a clinical parameter indicating local inflammation. mcfarlance and meikle (19) reported that the concentration of il-2 and soluble il-2 receptor in serum were significantly higher in patients with severe generalized periodontitis than that in control group, they suggested that il-2 could be related to the pathogenesis of inflammatory periodontal disease. also yetkínet al. (20) demonstrated that the serum level of il-2 was significantly higher in aggressive periodontitis in comparison to control group (p< 0.05). however, in study done by al-ghurabeiet al. (21) reported that there were no statistically significant differences in the level of il-2 in sera of periodontitis patients when compared to the periodontally healthy population (p > 0.05). they reported that this lack of statistically significance may reflect the various contributions made by periodontal disease to the total burden of inflammation in different patients and relatively small number of patients .though, our findings was in contrast with the observations of gemmell and seymour (1994) (22), who found low levels of il-2 and ifn-γ in periodontal lesions, and suggested decreased th1 responses. gorskaet al. (23) who founded that higher production of (il-1β, tnf-α, il-2, ifn-γ, il-4, il-10) in patients with severe cp subjects may be a marker of continuous th1 response against bacterial pathogens colonized in gingival tissue, with simultaneous suppression of th2 cell activity. significantly higher concentrations of (il-1β, tnf-a, ifn-γ and il-2) found in inflamed tissue in comparison with healthy tissue and serum samples support the local production of these cytokines and thus, may indirectly indicate strong activation of the monocyte/ macrophage system and th1 cells in inflamed gingival sites, they play an important role in the initiation and progression of periodontitis. moreover, they founded positive associations between severe cal and high levels of tnf-α, ifn-γ and il-2 in periodontitis patients who had pocket depths exceeding 5mm. the effect of initial periodontal therapy on gcf cytokine levels in subjects with generalized sever cp were assessed by thunell et al. (24) using a multiplex immunoassay, found a significant reductions in total amount of a group of cytokines particularly il-2 at disease sites as a result of initial therapy. it is well established that with increasing inflammation, there are increasing amount of gcf (25). this could relatively be the reason for higher concentration of il-2 in healthy sites compared to disease sites in the previous studies (26). although the expression pattern is variable, these findings, together with results of present study, indicating that there is an association between il-2 and periodontal disease. teles et al. (27) conducted a pilot study on 118 subjects; 74 chronic periodontitis and 44 periodontally healthy individuals, and assessed j bagh college dentistry vol. 28(2), june 2016 effect of periodontal oral and maxillofacial surgery and periodontics 77 the salivary levels of different cytokines, including il-2 by elisa method. they found that the level of il-2 was higher in patients with cp than that in control group but statistically not significant (p > 0.05) and did not correlate with the clinical parameters. with regard to periodontal diseases, previous data obtained using a protein microarray showed that a higher level of il-2 was expressed in saliva in periodontitis patients than in healthy controls although differences did not reach statistical significance(p > 0.05) (28). in a study by takeuchi et al. (29). it was suggested that the expression rate of the interleukin-2 receptor on t-helper cells and b cells was highest in gingival crevicular flow, lower in gingival tissue and lowest in peripheral blood. moreover, interleukin-2 up-regulates the expression of intercellular adhesion molecule-1 on the surface of human the adhesion of neutrophils is consistently increased (30). in animal in vitro experiments it was shown that the release of interleukin-2 by mononuclear cells could be activated by a fimbrial protein of porphyromonas gingivalis (31). furthermore, interleukin-2 induced an elevation in the production of osteoclastic acid, corresponding to an increased resorption of bone (32). there has been absolutely no documented evidence in human regarding the detection of il-2 in serum and saliva of subjects with cp before and after periodontal therapy, also correlating the local and systemic levels of il-2 with periodontal clinical parameters which makes this study the first to report such correlation. this study revealed that there was a positive correlation between the increase of salivary il-2 level with decrease of ppd in cp post therapy (r= 0.448, p= 0.025). these data suggest that a significant relationship exists between the amount of a proinflammatory cytokine (il-2) and the destruction of periodontal tissue. thus, the presence of elevated levels of il-2 in the saliva of patients with chronic periodontitis, along with the significant correlation with clinical assessments of periodontal tissue destruction, strongly suggests an important role for this mediator in the pathogenesis of periodontal disease.consequently, we could not find any association between the expression of il-2 in serum samples from both groups and clinical parameters, indicative of periodontal inflammation, in the entire group as supported in systemic review by paraskevaset al.(33) who affirmed that chronic periodontitis induces a state of systemic inflammation. the expression pattern is variable, these results, together with our results, indicate that there is an association between il-2 and periodontal disease, although our study was longitudinal study not cross sectional study or may be due to our follow up, the time interval (one month) between the clinical examinations, before and after treatment may be too short to observe more obvious clinical change in some patients, if we estimated il-2 in gingival tissue of specific affected site (an inflamed gingival site) may be there is a clear correlation, in conclusion, based on the finding of the present study, elevated serum and salivary il-2 levels post-therapy in patients with chronic periodontitis compared to healthy controls may suggest a close association between serum and salivary il-2 and periodontal status, therefore, we suggest that serum and salivary il-2 might be potentially useful in distinguishing health from disease and monitoring periodontal disease activity further longitudinal studies with a larger population and longer duration should be performed to confirm serum and salivary il-2 as a marker for periodontal disease. acknowledgment the author would like to thank to all patients and healthy controls for their cooperation in this study. we thank the entire department of periodontics, college of dentistry/ hawler medical university for their grant support particularly dr. hozan warya for her valuable contribution in the study. references 1. fujihashi k, kono y, beagley kw, yamamoto m, mcghee jr, mestecky j, et al. cytokines and periodontal disease: immunopathological role of interleukins for b cell responses in chronic inflamed gingival tissues. j periodontol 1993; 64: 400-6. 2. tatakis dn, kumar ps. etiology and pathogenesis of periodontal diseases. dent clin north am 2005; 49(3): 491–516. 3. march pd, devine da. how is the development of dental biofilms influenced by the host? j clin periodontol 2011; 38(s11): 28-35. 4. gemmell e, seymour gj. immunoregulatory control of th1/th2 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beta-8, and -10 and rantes in gingival crevicular fluid and cell populations in adult periodontitis patients and the effect of periodontal treatment. j periodontol 2000; 71:1535– 45. 27. teles rp, likhari v, socransky ss, haffajee ad. salivary cytokine levels in subjects with chronic periodontitis and in periodontally healthy individuals: a cross-sectional study. j periodontal res 2009; 44(3):411–7. 28. ramseier ca, kinney js, herr ae, braun t, sugai jv, shelburne cv, et al. identification of pathogen and host-response markers correlated with periodontal disease. j periodontol 2009; 80:436–46. 29. takeuchi y, yoshie h, hara k. expression of interleukin-2 receptor and hla-dr on lymphocyte subsets of gingival crevicular fluid in patients with periodontitis. j periodont res 1991; 26: 502–10. 30. ozawa a1, tada h, tamai r, uehara a, watanabe k, yamaguchi t, shimauchi h, takada h, sugawara s. expression of il-2 receptor beta and gamma chains by human gingival fibroblasts and up-regulation of adhesion to neutrophils in response to il-2. j leukoc biol. 2003; 74(3): 352-9. 31. ogawa t1, uchida h, yasuda k. mapping of murine th1 and th2 helper t-cell epitopes on fimbriae from porphyromonas gingivalis. j med microbiol 1995; 42(3):165-70. 32. ries wl, seeds mc, key ll. interleukin2 stimulates osteoclastic activity: increased acid production and radioactive calcium release. j periodontal res 1989; 24: 242–6. 33. paraskevas s, huizinga jd, loos bg. a systematic review and meta-analyses on c-reactive protein in relation to periodontitis. j clin periodontol 2008; 35(4): 277-90. journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 34 research article impact of different types of storage media on enamel surface roughness and granularity distribution of avulsed teeth (in vitro study) rawaa s. obeid 1* , muna s. khalaf 2 1master student, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. 2assistant professor, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. bab-almoadham, p.o. box 1417, baghdad, iraq.  correspondence: srwa3713@gmail.com abstract: background: to investigate the effect of different types of storage media on enamel surface microstructure of avulsed teeth by using atomic force microscope.materials and methods : twelve teeth blocks from freshly extracted premolars for orthodontic treatment were selected . the study samples were divided into three groups according to type of storage media :a-egg white , bprobiotic yogurt , and c-bovine milk . all the samples were examined for changes in surface roughness and surface granularity distribution using atomic force microscope, at two periods: baseline, and after 8 hours of immersing in the three types of storage media. results: milk group had showed a significant increase in the mean of the roughness values at the test period, while the egg white and the probiotic yogurt groups showed decrease in the surface roughness at the test period. no significant changes was found in the grain size of enamel surface of the avulsed tooth in any types of three storage media at eight hours interval. the use of egg white and probiotic yogurt to store the samples may be beneficial in that they contain various ions and proteins that fill up enamel valleys, while the longer periods of milk exposure encourage the bacteria to continue fermenting lactose, resulting in continual acid generation and increased demineralization. conclusion : milk group demonstrated the highest roughness values, while the egg white group demonstrated the lowest roughness values of the teeth. no significant changes in the grain size of enamel surface of the tested teeth in any types of three storage media at eight hours interval . keywords: atomic force microscope, avulsion, bovine milk, egg white, granularity distribution , probiotic yogurt, storage media , surface roughness. introduction the most extreme of all sorts of traumatic dental injuries is avulsion of permanent teeth, which occurs when the tooth is completely dislodged from its position, causing extensive harm to the supportive tissue, vascular, and nerve components (1). the survival of the periodontal ligament (pdl) that are cells residual on the root surface, the integrity of the root cementum, and limited microbial contamination, all of which are circumstances specifically linked to the extra-alveolar period. sort of storage after avulsion, and root surface changes, can determine the outcome of a replanted tooth as well as its preservation on the dental arch for the lengthiest probable period , the ideal treatment for an avulsed permanent tooth is its immediate replantation into the socket. despite its acknowledged therapeutic efficacy, clinical practice has demonstrated that immediate replanting is uncommon owing to injury related circumstances, such as the existence of life-threatening incidents, the recipient location if subjected to significant damage, the patient's emotive state at the time of incident, or easily an insufficient information or trust in replantation received: date: 01-03-2022 accepted: date: 10-04-2022 published: date: 15-12-2022 copyright: © 2022 by the authoruthors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) liscence (https://creativecommons.org/li censes/by/4.0/). https://doi.org/10.26477 /jbcd.v34i4.3275 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3089 https://doi.org/10.26477/jbcd.v34i1.3089 j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 35 techniques among the common people or even practitioners(2). enamel is the tooth's exterior protective layer. tooth demineralization is accelerated in acidic environment, which leads to cavity formation(3). surface texture includes roughness. the variations in the orientation of a practical surface's vector from its perfect form are used to assess it. the surface is rough if the deviations are considerable; smooth if the variances are minimal(4). when periodontal ligament cells are out of their alveolar socket, there are solutions that can prolong their lives. these options must be employed if immediate reimplantation is not possible (5). dry storage (up to 30 minutes) can induce more root resorption and is more detrimental to maintaining a normal pdl as compared to wet storage (6). natural products had been investigated as potential pharmacological substitutes, and as interest in complementary and alternative medicine has grown, numerous studies on the use of natural products for tissue healing had been carried out (7). because natural ingredients are easily available and have the ability to keep pdl cells alive for longer periods of time, they can be employed as storage media (8). egg white is a viable alternative as a storage medium for teeth undergoing delayed replantation because of its high protein, vitamin, and water content, lack of microbial contamination, and ease of access (9). milk has several benefits as a storage medium for the avulsed teeth, including being an isotonic liquid with physiological osmolality and ph, containing growth factors and vital nutrients for cells, and being widely available and inexpensive(9). probiotics bifidobacterium can also contribute to good health by creating a microbiological balance in the oral and decreasing bacteria's acidogenicity via oral defense systems like the peroxidase system , because bifidibacterium animalis dn 173010 appears to be an alternative for temporary preservation of avulsed teeth. this is due to the high number of pdl cells that remain viable on the root surface of the avulsed tooth, probiotics may be a potential transport medium for avulsed teeth (10). there is no available data related to the effect of different types of storage media on surface roughness and surface granularity distribution of the enamel of avulsed teeth. the aim of this study was to evaluate and compare the effect of different types of storage media on enamel microstructure of avulsed teeth by using atomic force microscope at two different time intervals. research question is there a difference in the effect of varies storage media on the enamel surface microstructure of the avulsed teeth? materials and methods premolar teeth that had just been extracted as part of a treatment plan for orthodontics were chosen. the teeth were gathered as soon as possible after the extraction, were preserved wet by placement in a universal glass tubes and kept in distilled water. at all times without any additional sanitizing treatment. following extraction, dental forceps were used to hold the coronal section of each tooth while a dental curette was used to scrape the pdl, rinsing with normal saline was done to remove blood cells (10). the procedure began with a naked-eye to do a visual examination of the teeth in favorable light. any teeth that were observed to be damaged or fractured were eliminated(11). to prevent the bacterial growth, the distilled water was changed once a week until the experiment was finished(12). non-fluoridated pumice was used to polish the teeth used for sample preparation (pumice powder, i dental company ,lithuanian) using a rubber cup (denmark), and a low-speed hand piece (strong 90saeshin precision co., ltd., korea) prior to experiment to remove any residual material from the tooth surface , then rinsed in distilled water and dried using cotton pads (china)(13). the crowns of the premolar teeth were separated from their roots at cementoenamel junction . the samples were prepared using a double-sided j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 36 diamond disc ( dental lab diamond disc, guangdong, china) at 4 x 4 mm width, and 2 mm thickness, and a low-speed handpiece with water cooling . to obtain correct dimensions, they were determined with an electronic digital caliper (sl01-1/-2, china). except for the outer enamel surface that was to be examined, all of the sample surfaces were painted with nail varnish all over, so that variations in texture of enamel could only be determined from the exposed surface. twelve teeth blocks from freshly extracted premolars for orthodontic treatment with closed apices and no caries were included in this study. the study samples were divided into three groups according to the type of the storage medium: • egg white group ; group a consists of four teeth blocks stored in green -colored universal tubes and immersed in egg white (fresh iraqi egg, mazarie albalad) for 8 hours. • probiotic yogurt group ; group b consists of four teeth blocks stored in pink-colored universal tubes and immersed in probiotic yogurt (al safi-danone iraq llc erbil-iraq) for 8 hours. • bovine milk group ; group c consists of four teeth blocks stored in orange-colored universal tubes and immersed in bovine milk (qirat iraq) for 8 hours. determination of the ph values of the storage media the physico-chemical parameters (salinity and ph ) were calculated using a wissenschaftlich technische werkstatten (wtw) multi-parameter inolab720, but only after standardizing the tool with standard ph and conductivity of electricity. wtw multi-parameter inolab 720 (wtw gmbh, weilheim, germany) is powered by two sensors: one that measures ph and the other that measures salinity(14). the glass electrode was inserted in it and the ph level was displayed on the meter is shown in table 1 . between readings the electrode was washed with distilled water and wiped with cotton pads to avoid of mixture of the materials (15). table 1: ph values of the storage media storage media ph egg white 9.5 probiotic yogurt 5.5 bovine milk 7.5 the surface topography properties of the enamel were examined using an atomic force microscope to evaluate the changes in the surface topography, which were determined before the experiment and after eight hours of exposure to three different natural storage media (egg white, probiotic yogurt, and bovine milk). the atomic force microscope examination was set in contact mode to obtain a topographic image from the surface. for each sample, pictures were obtained at 3080 × 3080 nm to create two-dimensional (2d) and three-dimensional (3-d) images. these measurements involved roughness parameters expressed in nanometers as follows: 1. average roughness (sa) : from a mean line, the arithmetic mean of peak heights and valley depths (13). 2. root mean square roughness (sq): the distribution of heights in relative to the mean line (13). j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 37 3. average maximum height (sz): within the sampling length, represents the profile's average maximum height, calculated over the five highest peaks zp and five deepest valleys zv (16). measurement periods: 1-baseline measurements :which were performed before starting the experiment, and considered as the control group. 2. eight hours’ interval measurements , which were made after exposure to the three types of storage media for eight hours. according to these periods, this study had a total of twenty four measurements for the twelve samples blocks used; divided into twelve measurements as baseline measurements for control group, and twelve measurements for experimental groups. granularity cumulation distribution, in addition to determining the average size of the nanoparticles that made up the surface, the reports of granularity cumulation shows the distribution of particle diameters over volume ratios of the samples )17). statistical analysis statistical package for social science (spss version 21) was used to describe, analyze, and present the data. statistical analyses can be categorized into two classes: descriptive statistics: minimum, maximum, mean, standard deviation (sd) for quantitative variable inferential statistics: a. shapiro wilk test : test the normality distribution of the quantitative variable. b. levene test : check if the variance is homogeneous between groups. c. one way analysis of variance (anova) : test the difference between k independent groups d. paired t test : test the difference between two measurements on the same subject or two related points. when the p value was < 0.05 it was considered as significant for all the statistical analysis. results normality test the normality of data was tested by shapiro-wilk test (table 2 and 3) which revealed that the samples were normally distributed. j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 38 table 2 : normality test of roughness among storage media and periods periods variabl es storage shapiro-wilk statistic p value ^ periods periods 8hr 0.907 0.763 0.825 0.927 0.766 0.867 0.956 0.866 0.927 0.997 0.866 0.862 1.000 0.907 0.820 0.927 0.918 0.851 8hr 0.468 0.051 0.156 0.578 0.054 0.286 0.753 0.284 0.578 0.991 0.284 0.267 0.999 0.467 0.144 0.575 0.524 0.229 baseline sa egg white probiotic yogurt bovine milk sq egg white probiotic yogurt bovine milk sz egg white probiotic yogurt bovine milk after 8 hours sa egg white probiotic yogurt bovine milk sq egg white probiotic yogurt bovine milk sz egg white probiotic yogurt bovine milk table 3: normality test of granularity diameter among periods and storage media variables storage media shapiro-wilk statistic p value 0.888 0.918 0.775 0.902 0.997 0.896 0.347 0.446 0.056 0.393 0.892 0.372 baseline egg white probiotic yogurt bovine milk after 8 hours egg white probiotic yogurt bovine milk j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 39 table 4 shows the minimum, maximum ,mean and standard deviation (sd) of surface roughness values for egg white ,probiotic yogurt and bovine milk at eight hours period. statistical analysis of the results using (anova) test demonstrates that no significant difference was found among egg white and probiotic yogurt groups in all the roughness parameters (sa, sq and sz) and at the test period. no significant difference was seen in milk group in (sa and sq) where as a significant difference was found for sz parameter (p = 0.025).at the test periods, the lowest recorded minimum , maximum ,mean and standard deviation values at the test periods of surface roughness in egg white group while the highest values were at the test period in surface roughness in milk group. table 4 : descriptive and statistical test of roughness among periods by storage media storage periods 8 hours min. max. mean ±sd f p alue egg white baseline sa 27.955 115.000 80.414 37.198 3.072 0.096 sq 33.630 137.000 94.358 43.713 3.576 0.072 sz 88.385 533.000 333.346 183.976 2.740 0.118 after 8 hours sa 28.034 79.800 52.934 21.770 1.100 0.374 sq 33.248 92.200 62.437 24.826 1.100 0.374 sz 89.149 319.000 209.787 107.410 .971 0.415 probiotic yogurt baseline sa 51.900 201.000 93.375 71.930 1.413 0.293 sq 59.900 260.000 115.675 96.430 1.329 0.312 sz 207.000 550.000 335.250 149.107 1.817 0.217 after 8 hours sa 48.000 98.200 66.550 21.956 1.022 0.398 sq 56.800 113.000 85.950 26.843 1.452 0.284 sz 126.000 393.000 282.000 123.129 1.023 0.398 bovine milk baseline sa 44.675 81.600 56.969 17.038 2.185 0.168 sq 56.700 97.300 71.360 18.060 2.583 0.130 sz 189.198 421.000 316.050 107.684 4.048 0.094 after 8 hours sa 83.700 93.119 88.380 4.719 2.812 0.113 sq 97.000 130.126 107.957 15.287 2.665 0.123 sz 347.000 426.468 376.867 34.395 5.752 0.025* *significant p value = 0.025, saaverage roughness, sqroot mean square roughness, sz-average height difference in surface roughness before and after immersion and within each medium can be seen in table 5 comparison of the roughness change for egg white , probiotic yogurt and bovine milk at the test period revealed that there was no statistical significant difference for the egg white and probiotic yogurt groups, where it was a significant difference for the milk group. table 5 : descriptive and statistical test of roughness before and after immersion and within each. j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 40 periods egg white probiotic yogurt bovine milk mean ±sd mean ±sd mean ±sd f p value 8hr presa 80.414 37.198 93.375 71.930 56.969 17.038 0.597 0.571 postsa 52.934 21.770 66.550 21.956 88.380 4.719 3.922 0.060 p 0.119 0.545 0.031* presq 94.358 43.713 115.675 96.430 71.360 18.060 0.511 0.616 postsq 62.437 24.826 85.950 26.843 107.957 15.287 3.959 0.058 p 0.119 0.554 0.061 presz 333.346 183.976 335.250 149.107 316.050 107.684 0.020 0.980 postsz 209.787 107.410 282.000 123.129 376.867 34.395 3.022 0.099 p 0.125 0.675 0.446 *significant at p<0.05 . pre =prior(before). post=after difference in granularity diameter between storage media before and after immersion and within each media is shown (table 6) , (table 7) revealed that there were no significant difference in all groups on the test period. table 6 : descriptive and statistical test of granularity diameter among periods by storage media storage periods 8 hr f p value ^ min. max. mean ±sd egg white before 93.340 118.790 103.450 13.507 0.485 0.638 after 101.820 151.840 122.077 26.330 2.225 0.189 probiotic before 104.100 150.800 123.423 24.369 0.439 0.664 after 82.830 192.080 135.673 54.712 1.716 0.257 milk before 101.260 109.630 104.060 4.824 2.122 0.201 after 96.290 129.610 109.667 17.604 0.736 0.518 table 7 : descriptive and statistical test of granularity diameter among storage media and periods . periods egg white probiotic yogurt bovine milk f p value ^ mean ±sd mean ±sd mean ±sd 8hr before 103.45 13.50 123.42 24.36 104.06 4.824 1.45 0.30 after 122.07 26.33 135.67 54.71 109.66 17.60 0.38 0.69 paired t test 1.035 0.539 0.460 p value 0.410 0.644 0.691 discussion the three roughness parameters roughness (sa, sq and sz) assessment were used to quantitatively evaluate the surface topography of each storage media of avulsed teeth. j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 41 a decrease in surface roughness (represented by mean sa, sq and sz values) from baseline periods measured by atomic force microscope was observed following immersing of the avulsed tooth in egg white. but the result were not statistically significant. this result came in agreement with hemingway et al.,( 2008) who reported that ovalbumin lowers the rate of hydroxyapatite dissolution under conditions that simulate tooth erosion caused by citrus-based soft beverages with a range of ph and calcium concentrations (18). this can be explained in that egg white contains various ions that fill up enamel valleys; creating a smoother surface and also alkaline ph and stability of ph in the all times of preserving of avulsed teeth . the primary protein contained in the white of hens' eggs is ovalbumin. bovine enamel adsorbs ovalbumin (19). probiotic yogurt decreased the surface roughness in terms of sa, sq and sz from baseline period which was observed after immersing of avulsed tooth in its. but the result was not statistically significant. this result was in agreement with ferrazzano et al., in 2008 who demonstrated that yogurt is a good source of calcium and phosphorus and has a greater protein level than milk. the advantageous ionic form of calcium is due to that the yogurt's lower ph as compared to milk. furthermore, because of the proteolytic activity of the microbe found in yogurt, the concentration of casein phosphopeptide is greater than in milk (20). the ionic form of calcium keeps the calcium in the tooth structure and the fluids around it in equilibrium (21). due to their natural presence of casein, calcium, and phosphorus, they are also thought to be safe for teeth, with possible favorable effects on both salivary microbial composition and caries development(22). in spite of the low ph of yogurt but it has high calcium and phosphate content which decrease the rate of erosion by remineralization of the tooth . nevertheless; the results of the current study were in disagreement with shen et al., in 2020 who reported that the high concentration of lactic acid, sugar, and live lactic acid generating bacteria in the processed yogurt causes considerable enamel subsurface demineralization(23). a significant increase in surface roughness (represented by mean sa, sq and sz values) from baseline period was noticed following immersing of avulsed tooth in bovine milk. the roughness values showed increase which suggested that more erosion occurs with increased exposure time to bovine milk. the results of this study were in agreement with lee et al., in 2011 who reported that micro-hardness was lower in the human and formula milk groups than in the control. in saliva and water , scan electron microscope (sem) observation demonstrated higher surface roughness and loss of inorganic substance in the formula milk group than in human milk(24). longer periods of milk exposure encourage bacteria to continue fermenting lactose, resulting in continual acid generation and increased demineralization. as a result, the amount of time the biofilm is immersed in milk is crucial (25). average diameter of grain size of enamel surface shown no significant changes in grain size of enamel surface of the avulsed tooth in any types of three storage media at eight hours interval . egg white and probiotic yogurt groups showed slight increase in the average diameter of grain size of enamel surface, but the results were not significant .this results might be explained in terms of the possibility of surface remineralization of enamel(19). j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 42 conclusion depending on the findings of this study, one can conclude that bovine milk group demonstrated the highest roughness values of the teeth at the test period, milk was highly erosive in comparison with remaining types of storage media. egg white group demonstrated the lowest roughness values of the teeth at the test periods and probiotic yogurt group showed the next lower roughness values. because chicken eggs and probiotic yogurt are readily available in markets, inexpensive, and can be obtained in almost every home, individuals can be taught how to preserve avulsed teeth by immersing them in these storage medium as soon as possible after an accident that results in tooth avulsion. references 1. gopikrishna v, baweja ps, venkateshbabu n, thomas t, kandaswamy d. retracted: comparison of coconut water, propolis, hbss, and milk on pdl cell survival. elsevier; 2008;34: 587-589. 2. de carvalho cardoso l, poi wr, panzarini sr, sonoda ck, da silveira rodrigues t, manfrin tm. knowledge of firefighters with special paramedic training of the emergency management of avulsed teeth. dental traumatology. 2009;25(1):58-63. 3. tsai m-t, wang y-l, yeh t-w, lee h-c, chen w-j, ke j-l, et al. early detection of enamel demineralization by optical coherence tomography. scientific reports. 2019;9(1):1-9. 4. zhai c, gan y, hanaor d, proust g, retraint d. the role of surface structure in normal contact stiffness. experimental mechanics. 2016;56(3):359-68. 5. lin s, zuckerman o, fuss z, ashkenazi m. new emphasis in the treatment of dental trauma: avulsion and luxation. dental traumatology. 2007;23(5):297-303. 6. marwah n. textbook of pediatric dentistry: jp medical ltd; 2018:71. 7. costa crr, amorim br, silva smmd, acevedo ac, magalhães pdo, guerra ens. in vitro evaluation of eugenia dysenterica in primary culture of human gingival fibroblast cells. brazilian oral research. 2019;33. 8. jain d, dasar pl, nagarajappa s. natural products as storage media for avulsed tooth. saudi endodontic journal. 2015;5(2):107. 9. goswami m, chaitra t, chaudhary s, manuja n, sinha a. strategies for periodontal ligament cell viability: an overview. journal of conservative dentistry: jcd. 2011;14(3):215. 10. caglar e, peker s, durhan ma, kulan p, kuscu oö, pisiriciler r, et al. kvantitativna analiza probiotskih medija za pohranu izbijenih zuba. acta stomatologica croatica. 2015;49(1):21-6. 11. prabhakar ar, yavagal cm, limaye ns, nadig b. effect of storage media on fracture resistance of reattached tooth fragments using g-aenial universal flo. journal of conservative dentistry: jcd. 2016;19(3):250. 12. özer t, başaran g, kama jd. surface roughness of the restored enamel after orthodontic treatment. american journal of orthodontics and dentofacial orthopedics. 2010;137(3):368-74. 13. karan s, kircelli bh, tasdelen b. enamel surface roughness after debonding: comparison of two different burs. the angle orthodontist. 2010;80(6):1081-8. 14. călin di, roşu c. drinking water quality assessment of rural wells from aiud area. advances in environmental sciences. 2011;3(2):108-22. 15. jain aa, bhat m, killada j, yadhav os, singh i. dental implications and laboratory evaluation of tooth dissolution in medicated liquid syrups. journal of advanced medical and dental sciences research. 2016;4(3):26. j. bagh. coll. dent. vol. 34, no. 4. 2022 obeid and khalaf 43 16. jasim ra, kadhim nj, farhan am, hadi ms, editors. nano-parctials as corrosion inhibitors for aluminum alloys in acidic solution at different temperatures. iop conference series: materials science and engineering; 2020: 928, 1-11iop publishing. 17. świetlicka i, muszyński s, tomaszewska e, dobrowolski p, kwaśniewska a, świetlicki m, et al. prenatally administered hmb modifies the enamel surface roughness in spiny mice offspring: an atomic force microscopy study. archives of oral biology. 2016;70:24-31. 18. hemingway c, shellis r, parker d, addy m, barbour m. inhibition of hydroxyapatite dissolution by ovalbumin as a function of ph, calcium concentration, protein concentration and acid type. caries research. 2008;42(5):348-53. 19. pearce e, bibby b. protein adsorption on bovine enamel. archives of oral biology. 1966;11(3):329-36. 20. 20. ferrazzano g, cantile t, quarto m, ingenito a, chianese l, addeo f. protective effect of yogurt extract on 21. dental enamel demineralization in vitro. australian dental journal. 2008;53(4):314-9. 22. singh c, doley s. invitro evaluation of the inhibitory effect of probiotic enriched and traditional yogurt extracts on dental enamel demineralization-comparative study. int j oral health med res. 2016;3(1):31-5. 23. levine r. milk, flavoured milk products and caries. british dental journal. 2001;191(1):20-. 24. shen p, fernando jr, walker gd, yuan y, reynolds c, reynolds ec. addition of cpp-acp to yogurt inhibits enamel subsurface demineralization. journal of dentistry. 2020;103:103506. 25. lee m-r, lee c-j, park j-h. the roughness & micro-hardness on the deciduous teeth according to formula milk or human milk. international journal of clinical preventive dentistry. 2011;7(4):179-88. 26. ricomini filho ap, de assis acm, oliveira bec, cury ja. cariogenic potential of human and bovine milk on enamel demineralization. caries research. 2021: 55:260–267 ( مختبرية سطح المينا لألسنان المخلوعة )دراسةخشونة وتوزيع حبيبات أنواع مختلفة من وسائط التخزين على فعالية: العنوان منى سليم خلف , عبيد( : رواء صادق الباحثون : المستخلص سطح المينا لألسنان المخلوعة باستخدافوائد حبيبات سطح و توزيع خشونة وسائط التخزين على من مختلفة مجهر القوة الذرية م : تقييم تأثير أنواع سنًا من الضواحك المقلوعة حديثًا للمعالجة التقويمية لألسنان . تم تقسيم عينات الدراسة إلى ثالث مجموعات اثنا عشر اريالمواد والطرق : لقد تم أخت وسائط التخزين ب-أ -حسب نوع ج -بياض البيض خشو -زبادي بروبيوتيك جميع العينات لمعرفة التغيرات في تم فحص . و نةحليب بقري السطح نان المخلوعة باستخدام مجهر القوة الذرية: قبل بدء التجربة و ثمانية ساعات من االنغماس في األنواع الثالثة لوسائط توزيع حبيبات السطح المينا لألس فتر النتائج التخزين في الخشونة قيم متوسط في معنوية زيادة الحليب مجموعة أظهرت زبادي ة: و البيض بياض مجموعات أظهرت االختبار. االختبار. ال توجد تغيرات كبيرة في حجم حبيبات سطح مينا األسنان المخلوعة في أي نوع من ةالبروبيوتيك انخفاًضا في متوسط قيمة الخشونة في فتر قد يكون استخدام زبادي نا.قطر حجم الحبوب لسطح الميسط في مجموعات بياض البيض والزبادي بروبيوتيك تظهر زيادة طفيفة في متو .وسائط تخزين وديان المينا, بينما يشجع التعرض للحليب ل مختلفة تمأل وبروتينات أيونات مفيدًا ألنه يحتوي على والبروبيوتيك لتخزين العينات فترات أطول البيض توليد األحماض وزيادة فقدان المعادن راريؤدي إلى استم البكتيريا على االستمرار في تخمير الالكتوز, مما : إعتمادا على النتائج المذكورة سابقا تم التوصل الى أن مجموعة الحليب أظهرت أعلى قيم خشونة بينما أظهرت مجموعة بياض البيض أقل اتاالستنتاج فترة االختبار في قيم خشونة لمينا األسنان . لم يكن للمجموعات الثالث أي تأثير على قيم توزيع حبيبات السطح type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 27 research article salivary protein carbonyl and selected antioxidants in relation to dental caries among pregnant women baydaa hussein awn 1* 1 assistant professor, department of pedodontic and preventive dentistry, college of dentistry, university of baghdad, baghdad, iraq * correspondance email: dr.baydaa.hussein@gmail.com abstract: background: pregnancy is a physiological condition that affects the general and oral health.it is also associated with an increase in oxidative stress, which may presispose to oral diseases including dental caries. aim of the study: this study aimed to measure salivary protein carbonyl, glutathione peroxidase and selenium levels of women who are pregnant and their association with dental caries in comparison to non-pregnant women, and to find out the mostly affected biomarker of oxidative stress during pregnancy. subjects, materials and methods: a cross-sectional research was performed for a samples of 30 pregnant and 30 non-pregnant women who were chosen from city of baghdad's primary healthcare centers. both groups aged 25-30 years. in unstimulated salivary samples protein carbonyl and glutathione peroxidase were determined colorimetrically using spectrophotometer by utilizing ready-made assay kits. salivary selenium level was obtained by atomic absorption spectrophotometer. plaque index had been used to determine the thickness of dental plaque. caries was recorded using the decayed, missing, and filled (dmf) index. described by who in 1997. data was statistically analyzed using descriptive statistics method and student's t-test, wilcoxon sum rank test and spearman’s correlation in addition to receiver operating characteristics curve (roc test) (α=5%). results: the plaque index and salivary protein carbonyl values were significantly higher among pregnant while salivary selenium and glutathione peroxidase recorded significantly lower levels among pregnant women. dental caries parameters were higher among pregnant with significant difference for ms fraction only. roc area for protein carbonyl equal one with highest sensitivity and specificity. conclusion: pregnant women recorded higher dental caries severity with higher salivary protein oxidation but lowers salivary antioxidant defense mechanisms. salivary protein carbonyl is more ideal, valid and mostly affected biomarker in revealing the oxidative stress status during pregnancy. keywords: dental caries, pregnancy, protein carbonyl, salivary glutathione peroxidase and selenium. introduction saliva has several merits like the presence of novel and soluble biomarkers, easy and non-invasive collection, continuous secretion and intimate contact with oral tissues reflecting physiological and pathological changes particularly those on the cellular molecular level. these merits make saliva a valid diagnostic fluid to screen, diagnose, and monitor disease progression (1). saliva is a unique complex oral fluid produced by salivary glands and has a significant impact on keeping the maintainability of oral hard as well as soft tissue through its complex physical and chemical composition (2). the body’s overall oxidative stress (os) and antioxidant system are presented in saliva. therefore, saliva is the first line of protection against os (3). salivary antioxidant system includes antioxidants with a low molecular weight as glutathione, vitamin e, ascorbic acid and uric acid in addition to peroxidase, catalase , superoxide dismutase, and glutathione peroxidase which act as an antioxidant enzymes (4) . the enzyme glutathione peroxidase (gpx) is selenium-dependent. it is one of most crucial enzymes in the regulation of reactive oxygen species (ross) by catalyzing the oxidation of other molecules (5) . received date: 10-09-2022 accepted date: 15-11-2022 published date: 15-03-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v35i1.3312 https://orcid.org/0000-0003-2408-7940 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3312 https://doi.org/10.26477/jbcd.v35i1.3312 j. bagh. coll. dent. vol. 35, no. 1. 2023 awn 28 antioxidant trace elements as selenium (se) are also found in saliva. it acts by reducing hydroperoxides of lipids and phospholipids, as well as hydrogen peroxide, thus further halted the spread of ros reactive oxygen species (6). because of their abundance and responsibility, proteins were indeed main targets for ros/rns (reactive oxygen species/reactive nitrogen species) in most functional processes in the cell. protein oxidation could occur at the single amino acid level residue causing polypeptide chains fragmentation or covalent crosslinking of two amino acids (7). when proteins are exposed to ross, modification of amino acid side chains occurs that leads to functional changes disturbing cellular metabolism. when protein side chains are oxidized, carbonyl (co) groups (aldehydes and ketones) are formed. because these moieties seem to be chemically stable, they can be detected and stored (8). under altered physiological conditions like pregnancy, highermetabolic demand and elevated requirements for tissue oxygen was reported during all three trimesters of normal pregnancy that results in an increased ross production (9). excessive ros production inside the oral cavity could result in oxidative stress (os). which is an imbalance for both oxidant and anti-oxidant systems. oxidative stress enhances an oxidative damaging of dna, lipids and proteins consequently in cell predisposing to several oral diseases as dental caries and periodontal diseases (10, 11). 14salivary oxidant/antioxidant imbalance was recorded during pregnancy (12). also elevated salivary protein carbonyl levels indicate higher salivary protein oxidation. was found among pregnant women (13). wagle et al (14) recorded higher oxidative damage (malondialdehyde “mda” content) and low level of total antioxidant capacity in saliva during pregnancy. similarly higher salivary “8-hydroxy-2’-deoxyguanosine (8-ohdg)” level but lower glutathione peroxidase (gpx) were recorded among pregnant compared to controls. such changes in salivary oxidants/antioxidants components of pregnant women make them susceptible to oral diseases as periodontal diseases (15). however, no studies could be found that relating salivary protein carbonyl ()gpx and se with dental caries parameters during pregnancy. dental caries diagnosis based on clinical and radiographic examinations is of limited use in early diagnosis because it provides a measure of past dental destruction (16). the early detection of tooth decay has an essential role in pregnancy, as it permits establishing preventive measures in addition restorative therapy is more expensive and sometimes involves general health risks (17). therefore, in view of the aforementioned findings and to address this gap this clinico-biochemical study was aimed to measure the pc, gpx and se levels in saliva of pregnant women during third trimester and their relations with the clinical index of dental caries the data was also compared to that of healthy married non-pregnant women. in addition,this study aimed to find out which salivary constituent (pc, gpx, or se) is the more affected oxidative stress biomarker during pregnancy. the null hypothesis was that salivary oxidants/antioxidants constituents remain stable throughout pregnancy and they have no relation with dental caries parameters. in addition, none of the measured salivary constituents was sensitive biomarker of oxidative stress. materials and methods sample size: utilizing the pilot survey of dental caries and g power 3.1.9.7 (a program created by franz-faul, university of kiel, germany) (ds) for both pregnant and non-pregnant groups about 10 subjects per individual with a mean±sd of 7.6±4.21 and 4.2±4 according to both groups, the power of the study is85%, the effect size is 0.828, and the probability error is 0.05. according to all these circumstances using 30 individuals for each is enough that will provide you the minimal sample size for each group, which is 28 people. study design: a cross-sectional study was conducted in a convenience sample of 60 women recruited at the primary health care centers in baghdad city in al-russafa sector. thirty pregnant women with an age range of 25-30 years in addition to thirty non-pregnant women that matched with age were included in the current study. only pregnant women in the third trimester were chosen..the non-pregnant women should be already married, nulliparous (never been pregnant before), and had a background of regular menstrual periods (28-30 days); they were chosen from pregnant women's companions. both preg j. bagh. coll. dent. vol. 35, no. 1. 2023 awn 29 nant and non-pregnant women should be non-smoker, with no medical history that compromises salivary secretory mechanism, shouldn't take any medications with xerogenic effect or any nutritional supplementation, and shouldn't wear any fixed or removable dental prostheses. the study carried out in the period from june to august 2019. collection of unstimulated saliva and recoding of dental plaque and dental caries status: unstimulated salivary specimens were collected under standardized condition according to the instructions listed by navazesh and kumar (2008)(18). the subject should avoid intake of food, chewing gum, beverage one hour before saliva collection. they should be seated on a chair, then irrigate their mouth with distilled water and relaxed for at least five minutes. then subjects should reduce their movement and instructed to fix their forehead above and the test tube kept beneath it. after that, the subjects were instructed to keep their mouth opened to allow the drain of saliva into the tube for five minutes. at the end of the collection period, the subject was asked to collect any remaining saliva in the mouth and spit it very quickly into the test tube. the actual trail should last for five minutes. after the foam all disappeared, saliva was placed into cooler box and sent to the laboratory and centrifuged for 10 minutes at 3000 rpm (revolution per minute); then separation of the supernatant was done by micropipette and kept in deep freezing (-20 ºc) in polyethylene tubes for the subsequent analyses. dental plaque thickness at the gingival third was assessed and diagnosed according to plaque index (pli) formulated by silness and löe (19). the pli was recorded on four dental surfaces (buccal, lingual, and proximal surfaces) of all present teeth. the values of four sites of each tooth were recorded in order to obtain the mean of pli for each tooth. the means of pli of all teeth of each volunteer was then calculated, followed by calculation of the mean pli of all volunteers. the decayed, missing, and filled (dmf) index was used to capture the data of caries experience. criteria of world health organization's description (who) (20). clinical examination of dental caries status was conducted by single examiner using a no. 05 clinical mirror and cpi probe (recommended by the who) for dental cries measurement and plunted probe for plaque index. repeating the measured data in ten patients yielded intra-examiner agreement of 0.950 and 0.958 kappa coefficient for pli and dmfs respectively. biochemical analysis of salivary samples: bio-chemical laboratory work was done at poisoning consul tation center at gazi al-hariry hospital in baghdad city. the protein carbonyl level in saliva was determined in (m/l) using a protein carbonyl assay kit. (sazakits, india). the principal of reaction of this kit is that, after oxidation, the protein carbonyl content increased, as well as the carbonyl group tend to react with 2,4-dinitrophenylhydrazine to create a reddish brown precipitate. after the precipitate has been dissolved, the absorbance could be observed at 370 nm. it is possible to indirectly calculate the carbonyl content (21) (salivary glutathione peroxidase concentration in (u/ml) was measured colorimetrically by the usage of gpx assay kit (thomas baker, india). salivary selenium level was measured in (mg/ml) by a spectrophotometeric system using spectrometer for atomic absorption nov 350aa model (22). the system uses absorption as its primary mode of action. statistical analysis: utilizing ibm spss software version25, data are analyzed (statistical package for social sciences). shapiro-wilk test was used for testing the normality of data. when analyzing non-normally distributed variables, median and mean rank were utilized instead of descriptive statistics such as mean and standard deviation. interferential statistics for normally distributed data was student's t-test, while for non-normally distributed variables, wolcoxon sum rank (w) test and spearman’s correlation tests were used. ethical aspects: an approval was achieved from the ministry of health for examining those women in addition the the ethical committee at the university of baghdad's college of dentistry had accepted the study's procedure. (i.e. the ethical committee authorized this study, no. 223320). the study protocol was explained to the participants and all participants signed written informed consents. j. bagh. coll. dent. vol. 35, no. 1. 2023 awn 30 results shapiro-wilk test was used to determine whether the sample's distribution was normal. findings indicated that the mean value for decayed fraction ds of dmfs index was normally distributed among both not pregnant and pregnant women (p=0.194, 0.257 respectively). however, plaque index, salivary protein carbonyl, selenium and glutathione peroxidase were non-normally distributed among pregnant and non-pregnant women (p<0.05) except for selenium that was normally distributed among non-pregnant women (p=0.752). results recorded in table 1 showed that the mean value of ds fraction was greater in pregnant women than non-pregnant women but with statistically non-significant difference after application of student’s t-test (p=0.778) between non-pregnant and pregnant women. also that median value for ms fraction was higher pregnant women than non-pregnant women. with significant difference (p=0.004) after application of wtest. regarding fs fraction the median value was zero in both expectant and non-expectant women, however, the fs fraction's mean rank value was higher among pregnant women with nonsignificant difference (p=0.793) after application of wtest. the median value of dmfs was also higher among woman with pregnancy compared to non-pregnant, but with no significant difference (p=0.192) after application of w test. for dental plaque thickness, it was recorded that the median value of pli was higher among pregnant women with significant difference (p=0.000) after application of w test. in table 2, data analysis revealed that the median value of salivary protein carbonyl compared to women who were not pregnant, was higher. by application of w test result revealed that the variation in median value of protein carbonyl was significant (p=0.000) between women who are pregnant and those who are not. however, salivary selenium revealed lower median value among pregnant compared to not pregnant with significant difference (p=0.036). similarly salivary glutathione peroxidase (gpx) median value was lower pregnant women compared to non-pregnant women with significant difference (p=0.000). application of spearman's correlation coefficient revealed no statistically significant relation (p>0.05) amongst salivary protein carbonyl, selenium and glutathione peroxidase levels with plaque index in both women who are and are not pregnant as illustrated in table 3. in table 4 only salivary selenium recorded inverse weak correlations with dental caries p arameters that were significant with ms and fs fractions (p=0.047, 0.042 respectively) and close to the confidence limit with dmfs (p=0.06) for pregnant women. only salivary glutathione peroxidase recorded inverse weak non-significant correlations with dental caries parameters (p>0.05) for non-pregnant women. the remaining relations were non-significant for pregnant as well as not pregnant (p>0.05). in table 5 and figure 1, pregnancy's impact on specific oral variables was analyzed by using the roc test. the curve's underside (auc) can be used in order for testing measurements according to their importance in discrimination between categories of women who are or are not pregnant (i.e. it can show which measurement are more affected by disease process (pregnancy) under study compared to non-pregnant). in the current study the area under the curve for salivary pc equal one with significant difference (p<0.05); therefore, it was the most affected oral variable by pregnancy (excellent for differentiation between study and control groups). j. bagh. coll. dent. vol. 35, no. 1. 2023 awn 31 table 1: descriptive statisitcs of dental caries parameters and plaque index for pregnant and non-pregnant groups and the statistical differences between them. variables groups pregnant non-pregnant df p-value no. mean ±sd no. mean ±sd ds 30 7.567 4.207 30 7.276 3.991 58 0.778ns no. median mean rank no. median mean rank w –test z-value pvalue ms 30 5.000 36.27 30 0.000 24.73 742.000 -2.861 .004 fs 30 0.000 30.87 30 0.000 30.13 904.000 -.262 .793 ns dmfs 30 13.500 33.43 30 9.000 27.57 827.000 -1.305 .192 ns pli 30 1.200 39.92 30 0.900 21.08 632.500 -4.193 .000 s s significant p≤ 0.05 table 2: descriptive statistics of salivary protein carbonyl and anti-oxidants for pregnant and non-pregnant groups and the statistical differences between them. variables groups pregnant non-pregnant no. median mean rank no. median mean rank w -test z-value pvalue pc (m/l) 30 1.348 45.50 30 1.126 15.50 465.000 -6.655 .000 hs se (mg/ml) 30 4.518 25.78 30 5.311 35.22 773.50 -2.095 0.036 s gpx (u/ml) 30 0.275 16.57 30 0.660 44.43 497.000 -6.188 .000 s=significant, m/l=mole per letter, u/ml= unit per milliliter, mg/ml=milligram/milliliter table 3: correlations of plaque index with salivary protein carbonyl and antioxidants for pregnant and non-pregnant groups. variable pregnant non-pregnant r p-value r p-value pc (m/l) .056 0.770 0.070 0.713 se (mg/ml) -0.282 0.131 -0.092 0.630 gpx (u/ml) 0.098 0.608 -0.254 0.176 m/l=mole per letter, u/ml= unit per milliliter, mg/ml=milligram/milliliter. table 4: correlations of dental caries parameters with salivary protein carbonyl and antioxidants for pregnant and non-pregnant groups. dental caries parameter pregnant non-pregnant pc (m/l) se (mg/ml) gpx (u/ml) pc (m/l) se (mg/ml) gpx (u/ml) r p r p r p r p r p r p ds 0.238 .205 -0.120 .526 .248 .187 0.287 .124 -.052 .785 -.166 .381 ms -.173 .361 -.366* .047 -.090 .635 .051 .788 .337 .068 -.064 .738 fs -.105 .580 -.374* .042 .014 .943 -.177 .350 -.192 .308 -.122 .521 dmfs 0.016 .933 -.340 .066 .121 .525 .154 .417 .030 .876 -.197 .296 j. bagh. coll. dent. vol. 35, no. 1. 2023 awn 32 table 5: effect of pregnancy on salivary variables (roc test). oral variables area under the curve (auc) p-value optimal cut-off point pc (m/l) 1.000 0.000 s 1.21 se (mg/ml) 0.343 0.036 s 0.91 gpx (u/ml) 0.036 0.000 s 0.1 s= significant. figure 1: roc curve for selected salivary variables. discussion salivary oxidative stress constituents reach their highest level during third trimester of pregnancy (23); therfore, the sample of this study included women in the third trimester. since unstimulated saliva is present all the time in the mouth, so it represents the major intra-oral condition. alivary stimulation process might also enhance the release of gingival crevicular fluid that contains antioxidants that might further increase antioxidants concentration in saliva (24) . the study results suggest that the null hypothesis was rejected since salivary protein carbonyl recorded significantly higher value among pregnant as compared to non-pregnant whereas salivary gpx and se revealed significantly lower values among pregnant women. therefore, the study results confirmed an increased salivary oxidative stress during pregnancy represented by higher salivary pc level but lower salivary gpx and se levels. these results go with the findings of previous studies (12, 14, 15) .the possible explanation for reduced salivary se and gpx during pregnancy probably because these antioxidants were exhausted while counteracting reactive oxygen species (25). another result that was recorded by the current study was inverse correlations of salivary selenium with dental caries parameters that were significant in case of ms and fs among pregnant women. this result might partially explain the higher decayed surfaces (present caries experience( though statistical difference was non-significant, and higher missing and filled surfaces (past caries experience) during pregnancy with significant difference for missing surfaces only. salivary oxidative stress has been found to affect the initiation and progression of dental caries (10). less is known about how oxidative stress j. bagh. coll. dent. vol. 35, no. 1. 2023 awn 33 affects the development of dental caries. however, it was found that salivary antioxidants perform a preventative function in the process of caries through inhibiting the inflammatory response occurs within dentine due to reactive oxygen species (ross) and high sucrose diet (26). another possible explanation is that the oxidation of proteins in both enamel and dentine by reactive oxygen species might weaken the tooth structure thereby increasing the susceptibility to dental caries (27). the main etiological factor in caries process is a complex biofilm (28). this is supported by the current study results as dental plaque accumulations was higher among pregnant than non-pregnant with significant difference. saliva has become a promising diagnostic fluid(1). salivary protein carbonyl is used as biomarkers of oxidative stress due to its stability and early formation (5). also this is confirmed in the current study as it was found that salivary protein carbonyl is the mostly affected biomarker of oxidative stress since the area under the curve for salivary pc equal one with significant difference (p<0.01). therefore, pc was the most affected oral variable by pregnancy as compared to salivary selenium and glutathione peroxidase. conclusions in conclusion, pregnant women recorded higher dental caries severity with higher protein oxidation, as indicated by the higher level of salivary protein carbonyl. with reduction in salivary antioxidant defense mechanisms (salivary selenium and glutathione peroxidase). only salivary selenium recorded inverse correlations with dental caries parameters. furthermore, salivary protein carbonyl could be considered a more ideal and valid biomarker in revealing the oxidative stress status during pregnancy. the following study limitations should also be taken into account.: despite earlier estimates, the sample size was modest; only pregnant women who visited primary health care centers made up the sample., so this prevent generalizing the clinical findings to all pregnant women. in addition, only the relation of salivary oxidative stress biomarkers with clinical index of dental caries was done, no mechanistic study was performed therefore, future both in vivo and in vitro researches are needed with larger sample size using panel of antioxidants and oxidative biomarkers to disclose the precise mode of action of these salivary oxidants/anti-oxidants constituents in caries process. the comparison of data with other studies however, may not be completely valid due to variation in study designs used by different researchers. conflict of interest: none. references 1. skutnik-radziszewska, a., maciejczyk, m., fejfer, k., et al. salivary antioxidants and oxidative stress in psoriatic patients: can salivary total oxidant status and oxidative status index be a plaque psoriasis biomarker? oxid med cell longev. 2020; 2020: pmc6964728. j. bagh. coll. dent. vol. 35, no. 1. 2023 awn 34 2. lorenzo-pouso, a.i., pérez-sayáns, m., bravo, s.b., et al. protein-based salivary profiles as novel biomarkers for oral diseases. dis markers. 2018; 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126(3): 325-30 . الحوامل النساء لدى األسنان تسوسمع و عالقتهم المختارة األكسدة ومضادات اللعابي كاربونيل البروتينالعنوان: بيداء حسين عون الباحثون: المستخلص: هدفت كما .الحوامل غير بالنساء مقارنة األسنان بتسوس وارتباطهن الحوامل النساء لدى والسيلينيوم بيروكسيديز والجلوتاثيون كاربونيل اللعابي البروتين مستويات قياس إلى الدراسة هدفتالهدف: الحمل أثناء التأكسدي لإلجهاد حساسية اللعابية الحيوية المؤشرات أكثر إيجاد إلى الدراسة هذه بين المجموعتين كلتا أعمار تتراوح. بغداد مدينة في األولية الصحية الرعاية مراكز من اختيارهن تم حامل غير امرأة 30 و حامل امرأة 30 من يناتلع مقطعي بحث إجراء تمالمواد وطريقة العمل: تم .الجاهزة الفحص مجموعات باستخدام الضوئي الطيف مقياس باستخدام لونية بطريقة بيروكسيديز والجلوتاثيون كاربونيل بروتين تحديد تم ، المحفزة غير اللعاب عينات في. عاًما 30 و 25 تسوسمال مؤشر باستخدام األسنان تسوس تسجيل تم .الجرثومية الصفيحة سمك لتحديد البالك مؤشر استخدام تم .الذري االمتصاص مقياس طريق عن اللعابي السيلينيوم مستوى على الحصول وعالقة u ويتني مان واختبار الطالب واختبار الوصفي اإلحصاء طريقة باستخدام إحصائيًا البيانات تحليل تم (.1997) العالمية الصحة منظمة وصفتها(. dmf) اسنانوالمعالج بحشوة والمفقود (. α = 5٪) (roc اختبار) االستقبال جهاز تشغيل خصائص منحنى إلى باإلضافة سبيرمان الحوامل النساء بين ملحوظ بشكل أقل مستويات بيروكسيديز والجلوتاثيون اللعابي السيلينيوم سجل بينما( p = 0.00) الحوامل بين أعلى اللعابي البروتين كاربونيل وقيم البالك مؤشر كانالنتيجة: (p = 0.03 ، p = 0.00 التوالي على.) لكسر معنوي فرق وجود مع الحوامل بين أعلى األسنان تسوس معامالت كانت ms فقط (p = 0.004 .)منطقة roc واحدة تساوي الكاربونيل للبروتين . وخصوصية حساسية أعلى مع أكثر حيوية عالمة اللعابي البروتين كاربونيل يعتبر. اللعابية األكسدة مضادات دفاع آليات من يقلل ولكن العالي اللعابي البروتين أكسدة مع أعلى أسنان تسوس شدة الحوامل النساء سجلتاالستنتاج: . الحمل أثناء التأكسدي اإلجهاد حالة عن الكشف في وحساسية وصالحة مثالية type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 17 research article experimental in vitro study to assess the antibacterial activity of thymus vulgaris oil on streptococcus sanguinis lubna fadhil shallal 1* , maha abdul-aziz ahmed2 1 master student, department of periodontology, college of dentistry, university of baghdad, iraq. 2 professor, department of periodontology, college of dentistry, university of baghdad, iraq. *correspondence: lubna.habib1904@codental.uobaghdad.edu.iq. abstract: background: the streptococcus genus are the predominant bacteria in the mouth and the streptococcus sanguinis is one of them which performing a primary function for expansion of dental biofilm. gingival and periodontal disorders are caused by dental biofilm, today, there is a necessity to discover naturally presenting antibacterial compounds from herbs with less side effects as a substitutive to the commonly handled chlorohexidine. thus, the purpose of this study was to assess the antibacterial activity of thymus vulgaris oil on streptococcus sanguinis bacteria in vitro. materials and methods: human supragingival plaque samples were taken from 10 subjects, then morphological and microscopical examination, biochemical tests, optochin test, hemolytic ability test and conventional polymerase chain reaction test was applied to assure coincidence of streptococcus sanguinis. the sensitivity of bacteria to thymus vulgaris oil, the minimum concentration that inhibit the growth and killed the test bacteria were identified a partly as comparable to 0.2% chlorhexidine as a positive control and10 % dimethyl sulphoxide as a negative control. results: thymus vulgaris oil presented a significant antibacterial property on streptococcus sanguinis with several grades of inhibition zones. when compared to chlorohexidine, thymus vulgaris oil had stronger antibacterial properties. the minimum concentration that inhibited the growth and killed streptococcus sanguinis was (0.09%). conclusion: thymus vulgaris oil displayed higher antibacterial action with each concentration on streptococcus sanguinis as compared to chlorohexidine, therefore; it can be used as a natural substitutive oral health care product to chlorohexidine. keywords: chlorhexidine, streptococcus sanguinis, antibacterial, thymus vulgaris oil. introduction the streptococcus genus are the main bacteria in the mouth and the streptococcus sanguinis (s. sanguinis) is one of the greatest predominant bacteria in the mouth (1), which stick to tooth surfaces pellicles supplying a sheet for following union of the late dental biofilm colonizers, thus performing a primary function for expansion of dental biofilm.(2) dental biofilm attaches quickly to tooth surfaces because they do not shed it. this is especially true along gingival edges. if remain unremoved, the microorganisms in dental biofilm multiply and the biofilm environment changes, resulting in increased pathogenicity and the development of a variety of oral disorders, primarily tooth decay and periodontal diseases.(3) mechanical dental biofilm management is the cornerstone of dental disease prevention, but it necessitates patient participation and drive. brushing and interdental cleaning methods are particularly challenging for old age individuals with physical or mental disabilities, malposed or isolated teeth, orthodontic and bridge appliances, (4) thus, chemical dental biofilm management products perform as beneficial adjunctive to accomplish the wanted outcomes.(5) the (chlorhexidine) chx has been handled as an adjuvant received date: 15-01-2022 accepted date: 26-02-2022 published date: 15-12-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/li censes/by/4.0/). https://doi.org/10.26477/ jbcd.v34i4.3273 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3214 https://doi.org/10.26477/jbcd.v34i3.3214 j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 18 product in conjunction with every day tooth cleaning and flossing program. (4) however, it has several side effects that limit its use.(6, 7) many herbal formulations have been reported to have antibiofilm efficacy when used as mouth washes and can be used as a substitution to chx with minimal side effects. (8) thymus vulgaris oil (tvo) has been considered as antibiofilm, antibacterial, antifungal and antispasmodic activities.(9, 10) although the tvo's antibacterial efficacy in vitro against a variety of human infections has been well demonstrated, there is limited data concerning the antibacterial effect of tvo on dental biofilm primary colonizers (s. sanguinis). thus, this study was conducted to assess the antibacterial effect of tvo against s. sanguinis. materials and methods the medical ethical committee of the university of baghdad's college of dentistry accepted the study procedure. thymus vulgaris oil thymus vulgaris oil (earthroma) brand, fig. (1), 100% pure oil was brought from united states and used in this investigation. the plant parts employed for this oil extraction were leaves and stems, and the place of origin was spain. the odor intensity was medium, and the extraction process was steam distilled. the liquid was a pale-yellow liquid with a relatively viscous yet clear viscosity. samples collection, isolation and identification of streptococcus sanguinis prior to collecting the samples, the subjects were told about the study and their consent and approval were acquired. human dental biofilm samples were collected from ten participants met the inclusion criteria which include any subject who had supragingival dental biofilm on their labial/buccal teeth surface, but those who used mouthwash or had taken antibiotics in the month before the study met the exclusion criteria. to avoid contact between tooth surfaces and oral mucosa, cotton rolls were used to isolate teeth from buccal/labial mucosa during the sampling procedure. the collection area was washed with water twice before being dried with air. using sterile periodontal gracey curette instruments, clinical isolates from supragingival dental biofilm were obtained from the buccal/labial surfaces of teeth. each scraping was immediately added to tube containing 3 ml brain-heart infusion broth (bhi-b) (tmmedia, india). then, at once taken to the laboratory and incubated aerobically at 37°c for 24 hrs. (11) for streptococcus spp. isolation, dental biofilm samples were cultured on the selective medium mitis salivarius agar (msa) (himedia, india). (12) after streaking the samples, the plates were placed into the incubator and incubated aerobically for 24 hrs. at 37°c. streptococci were sub cultured from the original msa plate to yield a pure bacterial isolate so, one very little colony was chosen and spread on msa plate using a sterile bacteriological loop. after that, the cells were incubated aerobically for 24 hrs. at 37°c. (13) morphological appearance on msa plates (14), gram ’s stain ability (15), catalase producing test (16), antibiotic sensitivity test (14), hemolytic ability (17), and polymerase chain reaction (pcr) were used to identify and diagnose s. sanguinis colonies. (12) j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 19 polymerase chain reaction 1.deoxyribonucleic acid extraction genomic dna was isolated from bacterial growth according to the protocol of abiopure extraction kit (abiopure, usa) as the following: one ml of overnight culture was centrifuged for 2 minutes at 13000 rpm to extract pellet cells. a100 µl of lysozyme and 100 µl of nuclease-free water were added to the 1.5ml centrifuge tubes containing the pellet and incubated in the water bath for 30 minutes at 37°c. after that, twenty μl of proteinase k (twenty mg/ml) and two hundred μl of binding buffer were applied to the sample for protein digestion and cell lysis. following that, two hundred μl of 100% ethanol was applied to the sample’s tube. all of the mixtures were then carefully transferred to small columns, centrifuged for 1 minute at 6,000 x g, and the collecting tubes were replaced. the mini column was then filled with 600 μl of prewash buffer, centrifuged for 1 minute at 6,000 x g. finally, 100 μl of elution buffer was applied to the tubes, which were then incubated for 1 minute at ambient temperature before being centrifuged for 5 minutes at 5,000 rpm. the acquired dna was then kept at –20°c. 2.thermal cycling procedure and reaction setup the following dna sequences were derived from published source and used in this study, (12), table (1). table 1: the pcr primers in this study primer name primer sequence annealing temp. (°c) expected size (bp) s. sanguinis-f 5’ggatagtggctcagggcagccagtt3’ 70 313 s.sanguinis-r 5’gaacagttgctggacttgcttgtc3’ the pcr was carried out in 20 μl of a reaction mixture containing 10 μlfrom gotaq® g2 green master mix 2x (promega, usa), 1μl of primerf 10 pmol/μl (macrogen, korea), 1μl of primer – r 10 pmol/μl (macrogen, korea) (fig. 1), 2 μl of purified dna, 6 μl nuclease free water. the final mixture was then transferred into conventional pcr tubes and vortexed for 5 seconds. the dna amplification was performed by (thermo fisher scientific, usa) (fig 2), using the following thermal profile: 95°c for 5 minutes (initial denaturation), followed by 30 cycles of 95°c during thirty seconds. for denaturation, 70°c during 30 sec. for annealing and extension at 72°c for one minute. final extension at 72°c for 7 min. and hold at 10°c for ten min. the pcr products were evaluated by electrophoresis gel system with 1.5 % agarose (fig 3), next to ethidium bromide 1 μl (10mg/ml) staining. the ethidium bromide-staining bands in gel were visualized by uv transilluminator. j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 20 figure 1: the green master mix and primers figure 2: the pcr tubes in 96 well thermal cycler figure 3: gel electrophoresis system preparation of standard bacterial cell suspension the direct colony suspension method was used to prepare and standardize the inoculum suspension according to smith and hussey (2005) technique. (18) the s.sanguinis suspension was standardized to match the turbidity of a 0.5 mcfarland standard, which equates to 1 x 108 colony forming unit (cfu/ml) using an absorbance microplate reader (glomax, promega, usa) with the cell density set to 0.6 and the wave length set to 600 nanometers (nm).(19) antibacterial assessment of the tvo to ensure precision and reproducibility of the results, every investigation aimed antibacterial assessment of the tvo were performed three times at three distinct days. 1.agar susceptibility experiment agar susceptibility protocol for cavalieri et al. in 2005 and abdulbaqi et al. in 2016 (18, 20) with some modifications was intended for antibacterial assessment experiment in this study. the mueller hinton agar j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 21 (mha) (mast group, u.k.) plates were inoculated with s.sanguinis suspension. to generate various concentrations of tvo (100 %, 75 %, 50 %, 25 %, 12.5 %), the tvo was diluted with 10% dimethyl sulphoxide (dmso) (cdh co., ltd. india) (21). wells (six mm in diameter) in the plate were made and filled with 50 μl of tvo at previously mentioned concentrations. the positive and negative controls, on the other hand, were 0.2 % chx and 10 % dmso, respectively. the plates were then incubated at 37°c for around 24 hrs., after which the inhibition zones of bacterial growth around the wells were measured with a ruler in mm (six mm of every well, was involved). 2.minimum inhibitory and minimum bactericidal concentration (mic and mbc) determination the mic of tvo on s. sanguinis was determined using a two-fold serial broth micro-dilution technique utilizing 96-well cell culture plates (promega, usa), subsequent to the technique of abdulbaqi et al. (2016) (20) with some changes. a100 μl of mueller hinton broth (mhb) was added to each of the twelve wells of the two rows, labelled w1-w12. then, in w1 of each row, (100 μl) of tvo with a concentration of 25 % was added, and a two-fold serial dilution was performed from well one to well nine. the w10, which served as a positive control, included 100 μl of a 0.2 % chx/nutrient broth mixture. the w11, comprised a 100 μl dmso/nutritional broth and it was served as the negative control. each well in the second row were impregnated with 100 μl of s. sanguinis suspension and incubated for 24 hrs. at 37°c, with the exception of the first row, which was left blank. after incubation, the loss of turbidity detected using an absorbance microplate reader at wave length equal to 600 nano meters (nm). the mic was the concentration of tvo in the well where absence of bacterial growth was noticed (20). the mbc was detected by subculturing a 100µl on mha plates from mic tube and one tube before it. the agar plates were incubated overnight at 37°c for 18-24 hours, and the readings were obtained the next day. the concentration which was equal or higher to mic with no growth of bacteria on mha after culturing regarded as mbc. (22) analytical statistics the spss (statistical package for social science) version 26 program was used to handle and analyze the data. descriptive statistics including means and standard deviations (std) were used. also, analysis of variance (anova) was utilized to examine the antibacterial effect of data. tukey's post hoc test was employed to determine whether there was a statistically significant difference between the two concentrations (data not shown). the levels of significance that was used, nonsignificant (n.s.) probability value (p – value) > 0.05, significant (s.) p ≤ 0.05. results the morphological characteristics of s. sanguinis on msa plate appeared as spherical or oval with raised or convex rubbery surfaces, blue in color and adherent to the agar surface (fig. 4). microscopic examination revealed that cells of s.sanguinis colonies showed gram (+) cocci that were arranged in intermediate or extended chains (fig. 5). on blood agar, the colonies with alpha hemolytic ability (fig. 6). they were catalase negative (fig. 7) and resistant to optochin test (fig. 8). the bacteria also identified by conventional pcr. there was a bond between pcr product of suspected bacteria and the primers of s. sanguinis. the amplification of s. sanguinis primer of bacterial species on 1.5% agarose gel electrophoresis stained with ethidium bromide resulted with 313 bp (fig. 9). j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 22 figure 4: the morphology of s. sanguinis colonies figure 5: microscopic appearance of on msa plate s.sanguinis figure 6: alpha hemolytic result of s.sanguinis figure 7: negative result of catalase test for on blood agar s.sanguinis m 1 figure 8: optochin sensitivity test of s.sanguinis figure 9: amplification of s. sanguinis primer. m: 100bp ladder marker, lanes resemble 313 bp pcr products agar susceptibility experiment showed that as the conc. of the tvo increased, the diameter of the inhibitory zones grew larger. all concentrations were effective against s.sanguinis bacteria, starting at 12.5 %, 25 %, 50 %, 75 %, and 100 %. the 10 % dmso revealed no inhibition zone on s.sanguinis bacteria, while the tvo at 12.5 %, 25 %, 50 %, 75%, and 100 % displayed higher mean values of the inhibition zones than chx. the maximum mean value of inhibition zone revealed by 100 % tvo was 60.90 mm., the results of the one-way anova test demonstrated significant difference between the varied concentrations of tvo with chx and dmso (table 2,3). j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 23 the findings of the comparison for the mean values of inhibition zones between every couple of dissimilar conc. for tvo and between each conc. of tvo with chx and dmso by tukey's post hoc test which were significantly differences (data not shown). table 2: the statistical analysis of s.sanguinis inhibition zones by different conc. of tvo, chx and dmso agents conc. no. mean in(mm) ± s. d. anova test chx 0.2% 9 29.11 0.78 *f=8085.0 *p=0.000 s. *d. f.=6 dmso 10% 9 0.00 0.00 tveo 12.5% 9 38.14 0.65 *p=probability *d.f.=degree of freedom *f= freedom table 3: the statistical analysis of s.sanguinis inhibition zones by different conc. of tvo, chx and dmso agents conc. no. mean in(mm) ± s. d. anova test tveo 25% 9 41.61 0.63 f=8085.0 p=0.000 s. d. f.=6 tveo 50% 9 44.78 0.58 tveo 75% 9 51.37 0.81 tveo 100% 9 60.90 0.71 in this study, experiments showed that the mic and mbc for tvo against s.sanguinis was at 0.09% (0.9 µl/ml ). discussion herbal rudiments were acquiring awareness as both protective plaque formation methods and as assessment remedies. the tvo exhibited antibacterial against microorganisms associated with formation of periodontal diseases (21), but there is restricted data concerning the anti-bacterial effect of tvo on primary dental biofilm colonizer (s.sanguinis). therefore, this study conducted. the tvo used in this study was from the company (earthroma), gas chromatography mass spectrometry (gc/ms) analysis revealed 17 compounds were identified. oxygenated monoterpenes were the major portion of this tvo. the major constituent was thymol (49.11%), followed by p-cymene (19.33 %), γ-terpinene (7.87%), linalool (5.03%), carvacrol (3.54%), β -caryophyllene (3.22%), α-pinene (2.04%) and borneol (1.95%). according to the composition of the oil, it is obvious that the tvo used in this study belong to thymol chemotype. the composition of tvo was almost similar to that used in previous study j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 24 which mentioned that thymol also being the major constituent, thymol (43.19%), pγ-terpinene (6.365%), cymene (28.55%) and carvacrol (3.14%), (23). by way of earlier stated the distinction of the chemical structure of the eos may be because of numerous reasons for example the inherited features, topographical source of plant material and collecting period. (24) in this study, agar wells susceptibility experiment presented well anti-bacterial effect on s.sanguinis bacteria. the diameters of the inhibition zones were raised as the conc. of the tvo raised. a study conducted by schött et al. (2017) (25) who observed obvious anti-bacterial effect of tvo against streptococcus mutans (s. mutans). also, a study done by de oliveira et al. (2021) (26) found that the antibacterial activity of tvo on s.mutans, streptococcus gordonii, streptococcus mitis, streptococcus sobrinus, lactobacillus acidophilus and actinomyces naeslundii was effective. the tvo used in this study of 12.5% ,25%, 50%, 75% and 100% concentrations showed larger inhibition zones than 0.2% chx and statistically all these concentrations presented significant differences, which suggests that they had higher antimicrobial activity than chx. the antibacterial effect of tvo associated with the phenolic compound’s thymol and carvacrol. (27) the tvo and thymol can rupture cell membrane and interposed deoxyribonucleic acid to influence the normal function of cells (28). the thymol which is stated to dissolve gram-negative bacteria's outer membrane and make their cytoplasmic membrane extra leaky. (29) carvacrol has ability to interrupt the folding and coding of proteins (30), as well as prevent the structuring of bacterial protein (flagellin) required for movement of bacteria. (31) the mic of tvo needed to inhibit s.sanguinis growth in broth media was 0.09 % conc. (0.9 μl/ml). also, the chx 0. 2 % used in this experiment as a positive control showed bacteriostatic effect against s.sanguinis. the outcome of mic in this study was in acceptance with previous reports which found a bacteriostatic effect of tvo against oral pathogenic bacteria lactobacillus species and s. mutans, in addition, other author founded a bacteriostatic activity for the tvo on staphylococcus aureus (s. aureus) and enterococcus species. (32, 33) a previous research was conducted to assess the activity of tveo on s.sanguinis bacteria and the result reveled antibacterial activity of tveo on this bacteria with mic was 160 µg/ml.(34) conversely, high value of mic or no inhibitory activity of tvo on some periodontal and streptococcal species were reported. (35, 36) the fact that tvo chemical composition and active constituent concentrations are greatly influenced by environmental factors such as temperature, physical situations, and term of gathering are mainly cause the differences in mic values presented by diverse researchers from different areas. (37, 38) in this study, the tvo presented killing activity on s. sanguinis. the mbc of the oil that kill s. sanguinis was 0.09 % (0.9 μl/ml) conc., other investigations who stated that tvo had killing activity on streptococcus salivarius, s. mutans, streptococcus pyogenes, s. aureus and enterococcus faecalis. (34, 39) j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 25 conclusion the thymus vulgaris oil was more effective as antibacterial agent than 0.2% chx against s. sanguinis, and could be utilized as a natural substitutive energetic product to chlorhexidine as periodontal health maintenance agent. conflict of interest: none. references 1. zhou x, li y. atlas of oral microbiology: from healthy microflora to disease: springer nature; 2021. 2. bathla s. periodontics revisited: jp medical ltd; 2011. 3. mcgrath c, zhou n, wong hm. a systematic review and meta-analysis of dental plaque control among children and adolescents with intellectual disabilities. 2019;32(3):522-32. 4. takenaka s, ohsumi t, noiri y. evidence-based strategy for dental biofilms: current evidence of mouthwashes on dental biofilm and gingivitis. jpn dent sci rev. 2019;55(1):33-40. 5. jafer m, patil s, hosmani j, bhandi sh, chalisserry ep, anil s. chemical plaque control strategies in the prevention of biofilm-associated oral diseases. j contemp dent pract. 2016;17(4):337-43. 6. supranoto s, slot d, addy m, van der weijden g. the effect of chlorhexidine dentifrice or gel versus chlorhexidine mouthwash on plaque, gingivitis, bleeding and tooth discoloration: a systematic review. int j dent hyg. 2015;13(2):83-92. 7. james p, worthington hv, parnell c, harding m, lamont t, cheung a, et al. chlorhexidine mouthrinse as an adjunctive treatment for gingival health. cochrane database syst rev. 2017;3(3):cd008676. 8. mehta s, pesapathy s, joseph m, tiwari pk, chawla s. comparative evaluation of a herbal mouthwash (freshol) with chlorhexidine on plaque accumulation, gingival inflammation, and salivary streptococcus mutans growth. j int soc prev community dent. 2013;3(1):25–8. 9. kryvtsova m, salamon i, koscova j, bucko d, spivak m. antimicrobial, antibiofilm and biochemichal properties of thymus vulgaris essential oil against clinical isolates of opportunistic infections. biosyst divers. 2019;27(3):270-5. 10. micucci m, protti m, aldini r, frosini m, corazza i, marzetti c, et al. thymus vulgaris l. essential oil solid formulation: chemical profile and spasmolytic and antimicrobial effects. biomolecules. 2020;10(6):860. 11. denepitiya l, kleinberg i. a comparison of the microbial compositions of pooled human dental plaque and salivary sediment. arch oral biol. 1982;27(9):739-45. 12. hoshino t, kawaguchi m, shimizu n, hoshino n, ooshima t, fujiwara t. pcr detection and identification of oral streptococci in saliva samples using gtf genes. diagn microbiol infect dis. 2004;48(3):195-9. 13. obaid z. m. ama-a. anti-bacterial effects of commiphora myrrha and ziziphus spina-christ leaves extracts against streptococcus mitis (primary colonizer of dental plaque) in vitro study. j res med dent sci. 2020;8(3):57-64. j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 26 14. england p. identification of streptococcus species, enterococcus species and morphologically similar organisms. uk stand microbiol investig. 2014; 4:1-36. 15. smith ac, hussey ma. gram stain protocols. asm. 2005; 1:14. 16. reiner k. catalase test protocol. asm. 2010. 17. buxton r. blood agar plates and hemolysis protocols. asm. 2005. 18. cavalieri s, harbeck r, mccarter y, ortez j, rankin i, sautter r, et al. manual of antimicrobial susceptibility testing. amer ican society for microbiology. paho: washington, dc, usa. 2005. 19. razak fa, othman ry, abd rahim zh. the effect of piper betle and psidium guajava extracts on the cell-surface hydrophobicity of selected early settlers of dental plaque. j oral sci. 2006;48(2):71-5. 20. abdulbaqi hr, himratul-aznita wh, baharuddin na. anti-plaque effect of a synergistic combination of green tea and salvadora persica l. against primary colonizers of dental plaque. arch oral biol. 2016; 70:117-24. 21. fani m, kohanteb j. in vitro antimicrobial activity of thymus vulgaris essential oil against major oral pathogens. j evid-based complement altern med. 2017;22(4):660-6. 22. thosar n, basak s, bahadure rn, rajurkar m. antimicrobial efficacy of five essential oils against oral pathogens: an in vitro study. eur j dent. 2013;7(s 01): s071-s7. 23. de carvalho rj, de souza gt, honório vg, de sousa jp, da conceição ml, maganani m, et al. comparative inhibitory effects of thymus vulgaris l. essential oil against staphylococcus aureus, listeria monocytogenes and mesophilic starter co-culture in cheese-mimicking models. food microbiol. 2015; 52:59-65. 24. tuttolomondo t, dugo g, ruberto g, leto c, napoli em, cicero n, et al. study of quantitative and qualitative variations in essential oils of sicilian rosmarinus officinalis l. nat prod res. 2015;29(20):1928-34. 25. schött g, liesegang s, gaunitz f, gleß a, basche s, hannig c, et al. the chemical composition of the pharmacologically active thymus species, its antibacterial activity against streptococcus mutans and the antiadherent effects of t. vulgaris on the bacterial colonization of the in situ pellicle. fitoterapia. 2017; 121:118-28. 26. de oliveira ma, da c vegian mr, brighenti fl, salvador mj, koga-ito cy. antibiofilm effects of thymus vulgaris and hyptis spicigera essential oils on cariogenic bacteria. future microbiol. 2021;16(4):241-55. 27. rota mc, herrera a, martínez rm, sotomayor ja, jordán mj. antimicrobial activity and chemical composition of thymus vulgaris, thymus zygis and thymus hyemalis essential oils. food control. 2008;19(7):681-7. 28. liu t, kang j, liu l. thymol as a critical component of thymus vulgaris l. essential oil combats pseudomonas aeruginosa by intercalating dna and inactivating biofilm. lwt. 2021; 136:110354. 29. lambert r, skandamis pn, coote pj, nychas gj. a study of the minimum inhibitory concentration and mode of action of oregano essential oil, thymol and carvacrol. j appl microbiol. 2001;91(3):453-62. j. bagh. coll. dent. vol. 34, no. 4. 2022 shallal and ahmed 27 30. burt s. essential oils: their antibacterial properties and potential applications in foods--a review. int j food microbiol. 2004;94(3):223-53. 31. rudramurthy gr, swamy mk, sinniah ur, ghasemzadeh a. nanoparticles: alternatives against drug-resistant pathogenic microbes. molecules. 2016;21(7):836. 32. sienkiewicz m, łysakowska m, denys p, kowalczyk e. the antimicrobial activity of thyme essential oil against multidrug resistant clinical bacterial strains. microb drug resist. 2012;18(2):137-48. 33. tardugno r, pellati f, iseppi r, bondi m, bruzzesi g, benvenuti s. phytochemical composition and in vitro screening of the antimicrobial activity of essential oils on oral pathogenic bacteria. nat prod res. 2018;32(5):544-51. 34. nikolić m, glamočlija j, ferreira ic, calhelha rc, fernandes â, marković t, et al. chemical composition, antimicrobial, antioxidant and antitumor activity of thymus serpyllum l., thymus algeriensis boiss. and reut and thymus vulgaris l. essential oils. ind crops prod. 2014; 52:183-90. 35. imelouane b, amhamdi h, wathelet j-p, ankit m, khedid k, el bachiri a. chemical composition and antimicrobial activity of essential oil of thyme (thymus vulgaris) from eastern morocco. int j agric biol. 2009;11(2):205-8. 36. rodriguez-garcia a, galan-wong lj, arevalo-niño k. development and in vitro evaluation of biopolymers as a delivery system against periodontopathogen microorganisms. acta odontol latinoam. 2010;23(2):158-63. 37. hernndeza t, canalesa m, durana a, garcaa am, avilaa jg, hernndez-portillab l, et al. variation in the hexanic extract composition of lippia graveolens in an arid zone from mexico: environmental influence or true chemotypes? open plant sci j. 2009;3(1): 29-34. 38. soković md, vukojević j, marin pd, brkić dd, vajs v, van griensven lj. chemical composition of essential oilsof thymus and mentha speciesand their antifungal activities. molecules. 2009;14(1):238-49. 39. al-badr rj, al-huwaizi hf. effect of tea tree, thymus vulgaris and nigella sativa oils on the elimination of enterococcus faecalis (in vitro study). j baghdad coll dent. 2017;29(1):55-62. سة مختبريه لتقييم فعالية التضاد البكتيري لزيت الزعتر البري على المكورات المسبحية نوع سانكوينس. العنوان:درا الباحثون: لبنى فاضل شالل ,مها عبد العزيز احمد. المستخلص: ي واحدة منها حيث تلعب دورا اساسيا في الخلفية:المكورات المسبحيه هي من اهم البكتريا الشائعه في الفم وان مكورات البكتريا المسبحيه نوع سانكوينس ه االعشاب مع تاثير تكوين طبقة البالك السنية.يعد سبب امراض والتهاب اللثة هو مادة البالك السنية حيث ان هناك حاجة الكتشاف مضادات بكتيرية طبيعية من تبريا على مكورات البكتريا المسبحيه نوع سانكوينس . جانبي اقل من الكلورهكسيدين .لذلك كان الغرض هو دراسة تاثير زيت الزعتر البري مخ البايوكميائية وكذلك تفاعل مشاركين ومن ثم فحص البكتريا بواسطة الشكل والتحليالت ١٠المواد والطرق العمل :اخذ عينات من مادة البالك السنيه من البوليمراز المتسلسل حيث تم تعين الحساسيه والحد االدنى لمنع وقتل البكتريا بوسطة زيت الزعتر البري مقارنة بالكلورهيكسيدين. ٪ .٠.٠٩النتائج: اظهرت النتائج ان لزيت الزعتر البري تاثير فعال على البكتريا حيث كان الحد االدنى لمنع وقتل البكتريا ن اجل انتاج منتجات االستنتاج:كان زيت الزعتر البري تاثير فعال وهو اعلى تاثيرا من الكلورهيكسيدين وبالتالي يمكن استخدامه كمنتج بديل للكلورهكسيدين م العنايه بالفم. noor.doc j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 182 the effect of er: yag laser on enamel resistance to caries during orthodontic treatment: an in vitro study noor m.h. garma, b.d.s., m.sc. (1) esraa s. jasim, b.d.s., m.sc. (1) abstract background: one common undesirable side effect of orthodontic treatment with fixed appliances is the development of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. different methods have been used to prevent demineralization; the recent effort to improve the resistance against the demineralization is by the application of lasers. materials and method: thirty human premolars extracted for orthodontic purposes were used to test the effect of two energy level of er-yag laser on enamel resistance to demineralization. the brackets were bonded on the teeth and all the labial surface excluding 2 mm area gingival to the brackets were painted with acid resistance varnish. three groups were generated. the first group was the control group (a) with no treatment was performed. in the second (group b) and third (group c) groups; teeth were irradiated by er-yag laser of 200, 60 mj energy respectively. all the teeth were individually subjected to acid challenge cycle for 30 days. after debonding longitudinal sections were taken and examined under stereomicroscope. the enamel demineralization evaluation was done by taking the average of three depths at the centre of the artificial lesion. also the enamel surface was classified by an experienced investigator according to acid etch pattern. comparisons of the average depth values of the groups were performed with anova and lsd tests. the statistical significance level was set at p ≤ 0.05. results: the results revealed that average lesion depth was significantly deeper at the control group than the laser groups, and it was significantly deeper in group (b) with 200 mj than in group (c) with 60 mj. enamel surfaces showed deeper pits and craters than in control group. conclusions: the decrease in artificial caries lesion depth associated with use of the two laser energy level support the er-yag laser as a tool to increase enamel resistance to demineralization and white spot lesion prevention. key words: demineralization, er-yag, laser. (j bagh coll dentistry 2015; 27(1):182-188). introduction one of the most difficult problems in orthodontic treatment with fixed appliances is the control of enamel demineralization around the brackets. (1) fixed orthodontic appliances complicate the removal of food debris that results in the accumulation of plaque. several studies have found an increased amount of plaque around orthodontic appliances. (2) plaque bacteria produce organic acids that cause the dissolution of calcium and phosphate ions from the enamel surface. this dissolution can cause white spots or early carious lesions to form in as little as 4 weeks. (3,4) significant increase in the prevalence and severity of enamel demineralization after orthodontic treatment when compared with untreated control subjects. the prevalence of white spot lesions in orthodontic patients has been reported between 2% and 96 %.(5-6) sognnaes and stern (7) were the first to advocate the potential of lasers to decrease enamel solubility and increase caries resistance. since that study, several studies have been conducted with different laser systems: argon, nd:yag, er:yag, er,cr:yssg, and carbon dioxide lasers.(8-13) it is well clear that with available technology, only erbium family lasers (er:yag and er,cr:ysgg) are suitable for this purpose. (1)lecturer. department of orthodontics. college of dentistry, university of baghdad. the wavelength of er: yag laser is highly absorbed by water and hydroxyapatite (14) making it suitable for both hard and soft tissue ablation. several factors may act together to achieve this reduction in caries susceptibility of lased enamel. the most likely mechanism for caries resistance is through the creation of microspaces within lased enamel. during demineralization, acid solutions penetrate into the enamel and result in release of calcium, phosphorus and fluoride ions. in sound enamel, these ions diffuse into the acid solutions and are released into the oral environment. with lased enamel, the microspaces created by laser irradiation, trap the released ions and act as sites for mineral re-precipitation within the enamel structure. thus, lased enamel has an increased affinity for calcium, phosphate and fluoride ions. (8) there are contradictory reports about the effect of er: yag laser on decreasing enamel solubility. cecchini et al. (9) used an er:yag laser with different parameters of irradiation and reported that lower energies (subablative dose) decreased enamel solubility. hossain et al. (16) reported an increase in the calcium to phosphorus ratio during laser irradiation, which resulted in caries inhibition showed improvement in crystalline structure and had the lowest mineral dissolution compared to control and phosphoric acid-etched specimens. another study showed that er: yag laser treatment reduced the carbonate content and j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 183 modified the organic matrix, thus providing caries-preventive effect on enamel. (17) however, some studies did not find any significant difference between er:yag-lased and non-lased groups with respect to the enamel demineralization. (18,19) apel et al. (20) observed that er:yag laser was unable to achieve any notable reduction in acid solubility of dental enamel. some authors concluded that the application of sub-ablative erbium lasers solely for preventive caries treatment does not seem to be sensible under the conditions they studied. (20,21) ahrari et al. (12) found in their study that er:yag laser does not reduce enamel demineralization when exposed to acid challenge, these conflicting findings brought up the demand to conduct this study for more basic data about er:yag laser role against enamel demineralization. materials and methods thirty human premolars extracted for orthodontic purposes were selected for this study. in transillumination examination, the selected teeth should have healthy enamel on the buccal surface, without attrition, fracture, restoration, congenital anomalies and structural defects. there was no history of chemical substance application such as hydrogen peroxide for these teeth. after cleaning the teeth from blood and debris, they were placed in thymol containing water for inhibiting bacterial growth until their use. the buccal enamel surfaces of the teeth were pumiced for 10 seconds, washed for 30 seconds, and dried for 10 seconds with a moisture-free air spray. before etching, a self-adhesive tape with a cut-out window the size of the bracket base was applied to each tooth to prevent etching and sealing of enamel areas that would later not be covered by the bracket. conventional etching was performed with 37% phosphoric acid for 15 seconds followed by rinsing for 30 seconds and drying for 10 second. all the teeth were bonded with edgewise premolar metal brackets with light cured composite resilience ® (ortho technology co., usa). the bracket was placed gently onto the centre of the labial surface using a clamping tweezers and pressed firmly into place. the adhesive tape and the excess adhesive were carefully removed, followed by light-curing for 3 seconds from the mesial and distal sides flash max 2 light cure unit (csm dental aps, denmark) at a distance of 2mm and a 45º angle to the surface. acid-resistant varnish was applied to each tooth by leaving a 2-mm rim of exposed sound enamel surrounding the bracket gingivally and left to set overnight. the teeth were allocated into three groups (n=10) according to the caries prevention way : group a: control group with no caries prevention method . group b: lased with 200 mj energy and 4 hz frequency of er:yag laser at a distance of 12mm with water for 20 seconds, the beam diameter at the focal area was 1.0 mm . group c: teeth lased with 60 mj energy and 2 hz frequency of er:yag laser at a distance of 4mm with water for 20 seconds, the beam diameter at the focal area was 1.0 mm. lasing method of the teeth in group b and c was done by using kavo laser unit (2060) (figure 1a). the teeth were placed in plastic jar cover filled with heavy body dough (figure 1b) and the buccal surface facing the laser handpiece which had been fixed in a special holder designed for this purpose at the recommended distance (figure 1c). the laser source was fixed while the teeth moved laterally beneath with a uniform motion. each tooth was placed separately in deionized water in a 10 ml plastic jar labeled with tooth group and number until they were subjected to the demineralization process. without removing the brackets, all the teeth were challenged by submerging in a demineralizing solution (0.075 m/l acetic acid, 1.0 m m/l calcium chloride, 2.0 m/l m potassium phosphate) at 37°c, the ph was adjusted to 4.3 by ph meter for 17 hour and remineralizing solution (150 m m/l potassium chloride, 1.5 m m/l calcium nitrate 0.9m m/l potassium phosphate) at 37°c, the ph was adjusted to 7 for 7 hour, this procedure were repeated for 30 days. a 5 minute wash with distilled and deionized water was done between the demineralizing and remineralizing phases and at the end of the process. each tooth cycled separately in individual containers and each solution was changed periodically every day throughout the 30 days procedure. after completing the demineralization procedure, the brackets were removed with straight bracket removing pliers (orthotechnology co., usa), then each tooth immersed in 0.5 % methylene blue solution for 24 hours. after that, each tooth was rinsed in tap water and air dried. (22) ground sections of approximately 100 µm of thickness were made in a coronal-apical direction right by the cusp edge so that each tooth was sectioned longitudinally by using water-cooled low speed saw of a hard-tissue microtome. j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 184 sections were carefully washed and placed in labeled petri dishes and were oriented longitudinally on glass cover slides, and then the sections were examined under stereomicroscope with maximum illumination. lesion depth was measured by taking the average of three representative measurements from the surface to the depth of the lesion that were 100 µm apart in the center of the carious lesion. one examiner performed all the measurements. figure 2 illustrates a lesion depth measurement. the enamel surface was classified by an experienced investigator, according to ibrahim et al (23) into: type i preferential dissolution of the prism cores resulting in a honey-comb-like appearance. type ii preferential dissolution of the prism peripheries creating a cobble stone-like appearance. type iii a mixture of type i and type ii patterns. type iv pitted enamel surfaces as well as structures that look like unfinished puzzles, maps or networks. type v flat, smooth surfaces. results the means values and standard deviation for the groups of this study are summarized in table 1. the results showed that the lowest mean value of the groups of this study was for the group c (group in which the samples was treated with 60 mj er:yag laser) while the highest mean value of the groups of this study was for the group a (control group). anova test was performed to identify the presence of statistically significant differences for all group of this study; the result showed that there was high statistically significant difference among these groups. lsd test was performed to identify the differences between each paired group. the results showed the group a has high statistical significant as compared with group b and group c while the group b has high statistical significant as compared with group c, when p value ≤ 0.05. table 1: the means values and standard deviation for the groups of this study groups mean(µm) s.d. group a 18.7 ±2.2 group b 14.3 ±0.63 group c 10.6 ±0.84 histopathological study: the histopathological examination revealed that the lesion mass difference between the three groups is more significant and well demarcated in the control group. it became smaller in group b and surrounded by remineralized enamel and it even smaller in group c with more remineralized enamel structure, as shown in figures 3a, 4a, 5a. difference in the types of enamel surface pattern in tested groups: group a has 60% of type iv of enamel surface, 20% of type iii of enamel surface and 20% of type v of enamel surface while the group b has 40% of type i of enamel surface, 20% of type ii of enamel surface, 20% of type iii of enamel surface and 20% of type v of enamel surface while the group c has 60% of type ii of enamel surface, 20% of type iii of enamel surface and 20% of type v of enamel surface. figures 3b, 4b, 4c and 5b, 5c illustrate the enamel surface pattern for the three groups. figure 1: a, kavo laser unit (2060) providing er-yag laser. b, the teeth were placed in plastic jar cover filled with heavy body dough. c, the buccal surface facing the laser handpiece which had been fixed in a special holder at the recommended distance c b a figure 2: magnified view of longitudinal section of demineralized lesion illustrate lesion depth measurement j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 185 discussion the strongly absorbed laser energy in the enamel is converted to heat that boils water abruptly. the boiled water forms high-pressure steam that leads to the ablation process when the pressure exceeds the ultimate strength of the tooth. during the ablation process, water evaporates explosively with tooth particles. the ablated materials and their successive recoil force create craters on the surface and the irradiated surface becomes a flaky structure with an irregularly serrated and microfissured morphology. (16) some researchers suggested that the caries protective effect of laser light has been attributed to the heat produced during laser irradiation which can cause changes in the chemical and crystalline structure of the enamel. (16,20,21,24) on the other hand, this surface morphology of irradiated enamel may be vulnerable to acid attack and mineral loss (27) and may be sites of high risk for bacterial accumulation creating favorable conditions for the development of carious lesions. (18) the advantage of etching with phosphoric acid is the high level of bracket bond strength achieved. on the other hand, the loss of mineral crystals, essentially the acid-protecting barrier, is inevitable (16), therefore; this research used the laser around the bracket to test its potential to increase acid resistance of enamel and prevention figure4: a, photomicrograph of enamel treated with 200 mj er:yag laser shows reminerlized enamel (re) and underneath it a focal deminerlized lesion (arrow) x4. b, view for pereferal dissolution of prism cores shows as a honey-comb like appearance (type i) .x 4. c, pitted enamel prisms (arrows) with deep craters (arrows heads).x4 a b c figure 3: a, photomicrograph view for surface enamel of control group, showed dark demineralization zone extends to dentine enamel junction (arrow head). b, longitudinal ground section shows extension of lesion (arrow) with rough pitted enamel. x4 a b figure 5: a, photomicrograph of enamel surface treated with 60 mj er:yag laser shows remineralization zone as a focal translucent area .a small demineralized lesion (arrow) was detected.x4. b, view for enamel prisms placed side by side, prism sheath shows form of ring(arrows). as cobbl stone form (type iii). x10. c, magnifying view for prism sheath shows thick sides with deep craters (arrows). x20 a b b j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 186 of white lesion hazards while keeping the advantage of high shear bond strength of conventional acid etch. it has been reported that caries preventive effects induced by er:yag laser treatment have been shown to depend on number of factors: the energy density of the laser, the irradiation time, the focal distance, and the irrigation conditions. (9,11,15,18,20,24,26,27) both ablative and subablative doses have been tested to try to decrease the acid solubility of enamel. the ablation threshold of the er:yag laser is also a controversial topic: it varies between 7 and 18.6 j/cm2 in the literature. (26,28,29) apel et al (18) suggested er:yag laser with energy densities below the ablation threshold, this is not to ablate or melt the surface but to change its structure or chemical composition attempting to increase its acid resistance. liu et al. (24) assessed the optimal laser energy range between 100 and 200 mj for the laser induced caries prevention with er:yag laser without water cooling and concluded that caries prevention might be achieved by using er:yag laser if the optimal ranges of laser parameters were chosen. altan et al (13) preferred a subablative dose in his study utilized 100 mj per pulse (12.73 j/cm2) with water spray surface cooling and obtained positive results in accordance with the results of hsu et al. (30) who presented marked caries inhibition using subablative laser parameters. also cecchini et al. (9) evaluated the different settings of er:yag laser on enamel acid resistance and reported that lower energies (60-80 mj) caused a significant reduction in enamel solubility. the temperature increase in pulpal tissue caused by laser irradiation with ablative doses should be considered. from this point of view, white and goodish (31) determined the safe limits for pulpal health to be 1 w and 10 hz. by considering the whole, we preferred a subablative dose (60-200) mj in this study with water cooling to simulate the clinical situation. both wave length energy showed that there is a marked reduction in the depth of the artificial carious lesion concomitants with er: yag laser irradiation, and this reduction was greater in group c (60 mj), there was a 24% reduction in mean lesion depth in group b and 44% reduction in group c in comparison with the control group and these significant results are in agreement with researches use subablative energies discussed above yet it can't be comparatively analyzed with them as different laser parameter were used. another aspect affecting the generated results is the method for assessing demineralization in er:yag laser studies making the comparison with other researches even more difficult. while the present study results were contradictory to that of ahrari et al (12) who observed a non increase of the enamel resistance to demineralization utilizing 300 mj of laser beam which was directed manually at 1 mm distance. also ulkur et al (32) stated that 80mj irradiation with 200 µs pulse duration and pulse frequency of 2hz was found ineffective against enamel demineralization. also this research disagreed with rodrı´guez-vilchis et al (33) who reported that the acid resistance of enamel due to subablative er: yag laser irradiation did not increase significantly compared to control. in the present study, a lower depth of caries lesion in the acidic solution of irradiated groups showed that enamel acid resistance was increased under the experimental conditions employed. however, this effect was more evident for group c than group b; this can be explained through that the increased enamel resistance to caries associated with lower energy could be compensated by the decreased irradiation distance since more laser effect can be achieved with less distance. the described irradiation distances ranged from contact mode to 17 mm working distance, on focused and/or defocused modes. regarding the er:yag laser settings advised for dental treatment, the laser irradiation distance is an important parameter, for being directly related to the laser ablation ability and surface morphology. (28,34) thus, depending on the established irradiation distance, the incident energy on dental surface increases the ablation depth or amplifies the irradiated site. (34) in fact, the dispersion of the energy occurs when the active tip is far off the substrate, causing a little amplification of the spot size (diameter of the beam) and consequently higher is the irradiated area, decreasing the performance of the laser on the tissue (35). the histopathological finding of lesion size difference between the three groups certainly support the mean lesion depth difference between the three groups discussed above, while the etching patterns were observed to vary between the examined teeth of the same group on contrast to the finding of cehreli and altay (36) who stated that all the samples within a group were found to be similar in the extent of surface irregularity. all the three groups showed rough and irregular enamel surface with craters but only the control group enamel showed deeper pitting with type iv dissolution, making the irradiated enamel superior from this point of view. within the limitations of this study, er: yag laser with subablative energy was found to be an j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 187 effective factor to fight white lesion associated with orthodontic brackets. references 1. zabokovaith-bilbilova e, stafilov t, sotovskaivkovska a, sokolovska f. prevention of enamel demineralization during orthodontic treatment: an in vitro study using gc tooth mousse. bal k j stom 2008; 12:133-7. 2. chang s, walsh lj, freer tj. enamel demineralization during orthodontic treatment. aetiology and prevention. australian dent j 1997; 42(5): 322-7 3. glatz egm, featherstone jdb. demineralization related to orthodontic bands and brackets. am j orthod 1985; 87: 87. 4. ogaard b, rolla g, arends j. orthodontic appliances and enamel demineralization. am j orthod dentofacial orthop 1988; 94: 6873. 5. gorelick l, geiger am, gwinnett aj. incidence of white spot formation after bonding and banding. am j orthod 1982; 81: 93-8. 6. ogaard b, rolla g, arends j, ten cate jm. orthodontic appliances and enamel demineralization. part 2. prevention and treatment of lesions. am j orthod dentofacial orthop 1988; 94: 1238. 7. sognnaes rf, stern rh. laser effect on resistance of human dental enamel to demineralization in vitro. j south calif dent assoc 1965; 33: 328–9. 8. duncan y, powell gl, higuchi wi, fox j. enhancement of argon laser effect on dissolution and loss of human enamel. j clin laser med surg 1993; 11(5): 259–61. 9. cecchini rcm, zezell dm, de oliveira e, de freitas pm, eduardo cp. effect of er:yag laser on enamel acid resistance: morphological and atomic spectrometry analysis. lasers surg med 2005; 37: 366–72. 10. hossain m, kimura y, nakamura y, yamada y, kinoshita ji, matsumoto k. a study on acquired acid resistance of enamel and dentin irradiated by er, cr:ysgg laser. j clin laser med surg 2001; 19:159– 63 11. hossain m, nakamura y, kimura y, mitsuhiro i, yamada y, matsumoto k. acquired acid resistance of dental hard tissues by co2 laser irradiation. j clin laser med surg 1999; 17: 223–226. 12. ahrari f, poosti m , motahari p. enamel resistance to demineralization following er:yag laser etching for bonding orthodontic brackets. dent res j (isfahan). 2012; 9(4): 472–7. 13. altan a b, baysal a, berkkan a, go¨ktolga-akın e g. effects of er:yag laser irradiation and topical fluoride application on inhibition of enamel demineralization turkish j orthod 2013;26:30–35 14. hale gm, querry mr. optical constants of water in the 200-nm to 200-microm wavelength region. appl opt. 1973; 12: 555–63. 15. hossain m, nakamura y, kimura y, yamada y, ito m, matsumoto k. caries-preventive effect of er:yag laserirradiation with or without water mist. j clin laser med surg. 2000; 18: 61–5. 16. kim jh, kwon ow, kim hi, kwon yh. acid resistance of erbium-doped yttrium aluminum garnet laser treated and phosphoric acid-etched enamels. angle orthod 2006; 76: 1052–6. 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(ivsl). الملخص الحاص رات، وبخاص ة واحد من اآلثار الجانبیة الشائعھ الغیر المرغوب فیھا خالل المعالجة التقویمیة مع األجھزة الثابتة ھو نمو تسوس االسنان أألول ي ح ول :خلفیة .تحسین المقاومة ضد تحلل المینا ھو استعمال اللیزروقد استخدمت أسالیب مختلفة لمنع تحلل المینا، الجھود الحدیثھ ل. في المرضى الذین یعانون من سوء صحة الفم لی زر عل ى مقاوم ة er-yagاستخدمت ثالثون من ضواحك اإلنسان المقلوعة ألغراض تقویم األسنان الختبار تأثیر اثن ین م ن مس توى طاق ةال :المواد والطریقة . مم من الجانب اللثوي للحاصرات تم طالئھ بواس طھ ط الء مق اوم للحموض ھ 2ء مساحة تم تثبیت الحاصرات على األسنان وكل السطح الشفوي باستثنا. المینا للتحلل االس نان ;)ج(والمجموعھ الثالث ھ ) ب(في المجموعة الثانیة . ، وقد اجریت بدون عالج)أ(وكانت المجموعة األولى ھي مجموعة السیطرة . تم إنشاء ثالث مجموعات . یوم ا 30جمیع األسنان تعرض ت بش كل ف ردي ل دورة التح دي الحمض یة لم دة . ملي جول على التوالي 60ل وطاقة ملي جو 200بطاقة er-yagأشعت باللیزر ثالث ة أعم اق ف ي مرك ز التس وس تقییم تحلل المین ا ت م ع ن طری ق أخ ذ متوس ط . stereomicroscopeبعد ازالت الحاصرات أخذت مقاطع طولیة وتم فحصھا تحت ق یم عم ق المجموع ات ت م اجرائھ ا م ع اختب ارات المقارن ات لمتوس ط . ینا تم تصنیفھ بواسطة باحث ذو خبرة وفقا لنمط الحفر الحمض یة كذالك سطح الم. االصطناعي anova وlsd . اخذ مستوى الداللة اإلحصائیة عندp ≤ 0.05. ) ب(رة من مجموعات اللیزر، وھي أعم ق بكثی ر ف ي المجموع ة أظھرت النتائج أن متوسط عمق التسوس االصطناعي كان أعمق بكثیر في مجموعة السیط :النتائج .سطوح المینا أظھرت تخدشات وحفر أعمق مما كانت علیھ في مجموعة السیطرة, ملي جول 60) ج(ملي جول مما كانت علیھ في المجموعة 200 لی زر مم ا دع م اس تخدام اللی زر ك أداة لزی ادة er-yagطاق ة ال انخفاض عمق التسوس االصطناعي لالس نان الم رتبط باس تخدام اثن ین م ن مس توى :االستنتاجات .مقاومة المینا للتحلل والوقایھ من آفة البقع البیضاء .اللیزر, er-yagتحلل المینا، :الكلمات الرئیسیة raed f.doc j bagh college dentistry vol. 25(3), september 2013 evaluation of treatment oral and maxillofacial surgery and periodontics 103 evaluation of treatment of intra-bony defects with a mixture of β-tricalcium phosphate hydroxyapatite granules and oily calcium hydroxide suspension raed a. badiea, b.d.s., m.sc. (1) abstract background: an oily calcium hydroxide formulation proved over the last years to be highly efficient in promoting bone regeneration in closed defects as periapical lesions, cysts, or post-extraction defects. the aim of the present study is the assessment of the outcome of treatment of deep intrabony periodontal defects with an open flap debridement) (ofd) + combination of {(30% hydroxyapatite hap + 70% β-tricalcium phosphate granules mixed with an oily calcium hydroxide suspension (ochs )} and compare the results with {(ofd) alone)}. the combination of ochs& tcp was used in humans with a sort of positive results, and more conduction of studies was recommended. material and method: the sample of this study composed of sixteen patients; each had at least two intrabony defect teeth. for each patient, one tooth was treated by ofd only (control group 16 teeth) and the other teeth (study group 16 teeth) were treated with ofd + a mixture of (osteon iikorea) granules comprise of (30% hydroxyapatite hap + 70% β-tricalcium phosphate) and ochs (osteoinductal®, osteoinductal gmbh., muenchen, germany). the clinical parameters that were measured and recorded included (plaque index pli, gingival index (gi), gingival recession(gr) , bleeding on probing (bop), probing pocket depth (ppd), clinical attachment level (cal) and radiographical width & depth of the bony defect. these parameters were recorded before treatment (base line) & six months after the treatment. results: the results after treatment revealed a highly significant reduction in all of the parameters except the pli in both study & control groups compared to baseline (p < 0.001). the clinical results were indicated that the study group showed significant reductions of ppd and cal mean values more than improvements obtained by the control group with significant difference (p < 0.05). conclusions: an excellent postoperative improvement in clinical parameters was noticed in the study group more than control group and the differences were significant. thus the present study has revealed that the treatment modality of ofd + a combination of granules comprise of (30% hydroxyapatite hap + 70% β-tricalcium phosphate) mixed with oily calcium hydroxide suspension is successful, predictable and more beneficial than (open flap debridement) (ofd) alone in the treatment of deep intrabony periodontal defects. key words: intrabony defects, β-tcp, hydroxyapatite, ochs. (j bagh coll dentistry 2013; 25(3):103-109). introduction regeneration of the lost periodontium has long been a goal of periodontal therapy. periodontal disease associated with vertical bony defect formation provides therapists with the opportunity to regenerate the lost periodontium, which can effectively re-establish health and improve support for the dentition. periodontal regeneration is defined as the restoration of alveolar bone, cementum, and a functionally oriented periodontal ligament on a previously diseased root surface (1). while the definition of periodontal regeneration is based upon histology, surrogate measures such as radiographic bone fill, probing depth reduction, and gain in clinical attachment level are used most often when clinically evaluating treated sites (2). the aim of periodontal regeneration is complete reconstruction of supporting structures lost as a result of periodontal disease. in recent years, many researchers have reported different treatment modalities to promote the regeneration of lost periodontal structures. described methods include: diverse flap preparation methods (3-5), biomodification of root surfaces with enamel (1)assistant professor. department of periodontics. college of dentistry. al-mustansiria university. matrix derivative (emd) proteins (6,7), guided tissue regeneration (gtr) (8-10) and use of growth factors (11). one of the most important factors affecting the results of periodontal regeneration is the keeping of the adequate space for the healing process. the significant problem is a collapse of mucoperiosteal flap into the bone defect (12) especially when using low consistency & soft with high fluidity materials like (emd) & (ochs). therefore, there is need for a scaffold, supporting the flap and stabilizing the blood clot (13). results from controlled clinical studies have shown that treatment of intrabony defects with open flap debridement (ofd) alone may lead to corresponding clinical results as after the adjunctive use of different biomaterials like βtricalcium phosphate and calcium phosphate bone cement (14,15). on the other hand, there have been reports showing, that, after bone defect filling with biomaterial, the clinical results may be superior to that achieved with the ofd procedure alone (16). results of clinical studies have reported the influence of an oily calcium hydroxide suspension (ochs) on bone regeneration in j bagh college dentistry vol. 25(3), september 2013 evaluation of treatment oral and maxillofacial surgery and periodontics 104 closed bony defects subsequent to periapical surgeries, in bone cysts and post-extraction alveolae (17). its osteostimulative effect is due to many factors, as the deposit action of the calcium hydroxide, which sustains the bone metabolism in a constant, mild alkali environment, the stimulation of the angiogenetic bone growth with concentration of the growth factors next to the defect wall, and the reduction of the inflammation in the operated site, which enhances the wound healing (18). histological and radiological analysis, both in animals and humans seem to indicate a predictable regeneration of closed bone defects (19). such results recently led to attempts to use the (ochs), alone or under various combinations, in regenerative bony treatment of periodontal defects. recently, histological studies in humans indicated that the treatment of chronic periodontal defects with ochs alone could lead to formation of a new attachment (cementum with inserting collagen fibers) and alveolar bone (20-22). however, from clinical point of view, some practical problems could arise when using the ochs alone: the material has a low consistency and, therefore, cannot ensure a sufficient stability of the mucoperiosteal flap, especially in one-wall and circular defects. frequently, a collapse of the mucoperiosteal flap cannot be avoided, followed by the reduction of the space necessary for the regeneration process (23). to overcome such problems, the combination of the ochs with a bone replacement material could offer a convenient solution. by this approach, the chemical and biological properties of the ochs could be combined with the mechanical properties of the bone replacement materials. in this combination, the ochs could enhance the bone and the periodontal healing, while the bone replacement material could avoid the collapse of the mucoperiosteal flaps and ensure the postsurgical stability of the wound. tricalcium phosphate (tcp) is a promising alternative bone fill material studied and used extensively in the past decades. it is considered to be bioactive (by means of inducing specific biologic reactions) and biocompatible (not stimulating inflammatory or foreign-body giant cell activity). this is mainly because tcp is composed of ca and p ions, which are the most commonly found elements in bone. however, tcp cements have a slower resorption rate than bone and are usually too dense to allow bone tissue to grow into the defect in a limited period of time. by adding a faster resorbing material, pores may be created, ensuring new bone tissue growing into the defect (24). β-tricalcium phosphate is a highly purified, multi-crystalloid, porous form of the calcium phosphate. it is partially resorbable and is normally used for the repair of non-pathologic sites, in which the resorption of the implant and a replacement by bone is expected (25). if the healing of the marginal periodontal defects is desired, tcp can provide repair similar to autologous bone (26). tcp is compatible to the host tissue (27). the healing of the periodontal wound occurs with bone in growth in the pores of the tcp (28). histological analysis of the healing of the defects revealed rather a long-junctional epithelium than a connective tissue attachment (29). hydroxyapatite (hap) has high biocompatibility and good bioaffinity, stimulates osteoconduction, and is slowly replaced by the host bone after implantation (30). since early in the 1980s, blocks and granules of porous hap have been widely used as a bone substitute in the fields of orthopedic, craniofacial, and periodontal regenerative surgical therapy. however, in order to establish an ideal bone substitute to induce new bone, it is necessary that it has a structure with the ability of osteogenic cells being able to easily penetrate deeply into the hap osseous grafting materials. recently, superporous hap has been developed, which has a high level of porosity of 85% (31). a conclusion of a study of li conghua et al. (32) showed that hydroxyapatite (hap) can be widely used in the areas of bone restoration and bone substitute. it is effective in the clinical treatment and will be widely used in the bone engineering. the combination of the mechanic properties of the tcp + hap (osteon ii) with the biological and chemical features of the ochs could be both of biologic and clinical interest. so far, there are no clinical data regarding the combined therapy of ochs and {tcp + hap} in the treatment of intrabony periodontal defects. the aim of the present study is the assessment of the outcome of periodontal treatment of deep intrabony defects with a combination of {(hydroxyapatite hap + b-tricalcium phosphate granules) (osteon ii) + oily suspension of calcium hydroxide} and compare this treatment modality with open flap debridement (ofd) alone. mateials and methods sixteen patients (10 males and 6 females), between 24 and 45 years old, non-smokers, each displaying at least 2 teeth with deep intrabony defects. for all of the patients, one tooth was treated by ofd only (control group 16 teeth) and the other teeth ( study group 16 teeth) were treated j bagh college dentistry vol. 25(3), september 2013 evaluation of treatment oral and maxillofacial surgery and periodontics 105 with ofd & a combination of granules comprise of (hydroxyapatite hap + b-tricalcium phosphate) ( osteon iikorea ) and oily calcium hydroxide suspension (osteoinductal®, osteoinductal gmbh., muenchen, germany). all patients were treated at al-mustansiriya university/college of dentistry by the same surgeon at clinics of the department of oral surgery and periodontology. inclusion criteria for the study were as follows: no systemic diseases which could influence the outcome of the therapy,. exclusion criteria were: furcation involvement of grade 3 and tooth mobility of degree 3, systemic diseases that required medication affecting periodontium and calcium supplements. teeth with mobility grade 2 were splinted at least two months before surgery. all patients underwent initial therapy one month prior to surgery. all patients were instructed and motivated to maintain a good oral hygiene level, verified by a reduction of the pli < 1. before surgery and six months after, the following clinical periodontal parameters were registered 1 week prior, then 6 months after the surgical procedure. the plaque index (pli), gingival index (gi) , bleeding on probing (bop) , probing pocket depth (ppd), gingival recession (gr) and clinical attachment level (cal) were measured. the measurements were made at six points per tooth: mesiobuccal (mb), midbuccal (b), distobuccal (db), mesiolingual (ml), midlingual (l), distolingual (dl). the deepest measured point at each surface was used for statistical analysis. the stent margin was used as a fixed reference point for measurement of attachment level . also pre and postoperative radiographs were taken using the long-cone parallel technique. there were two parameters analyzed on the radiographs: defect depth – the vertical distance between the bone crest and the site on the root surface at which the periodontium width was normal (in mm), defect width – the horizontal distance between the root surface and bone defect margin in the most coronal part of the bone crest (in mm) (33). surgical procedure intrasulcular incisions, mucoperiosteal flaps were elevated facially and lingaully. vertical releasing incisions were made if necessary only in the study group to ensure better wound closure after bone filler placement. after granulation tissue removal from bone defects, roots surfaces were scaled and planed using ultrasonic instruments followed manual instomentation. in the ofd group after debridement, mucoperiosteal flaps were repositioned and sutured. in study group, before flap closure, intrabony defects were filled with bone substitute material. all patients received antibiotics for one week (3 × 625 mg augmentin per day). postoperative care consisted of chlorhexidine ( corsodyl) rinses twice a day for 4 weeks with intervals of stopping rinse among the 4 weeks. sutures were removed 14 days post surgery. recall appointments were scheduled every week during the first month, later, every 3 months. during recall appointments, supragingival plaque was carefully removed with a brush. statistical analysis statistical analysis was performed with statistica 10 software (statsoft, tulsa oh, usa). for comparison between groups, the nonparametric u-mann–whitney test was used. for the statistical evaluation of the changes from baseline and 6 months, the paired t-test was used, x2 was used for bop. results were considered statistically significant at a p value less than 0.05. results healing was uneventful in all patients. no adverse reactions to bone fill materials were observed. the morphology of treated defects in the majority of cases was 3 wall in both groups. the distribution and configuration of treated defects are demonstrated in (table 1). there were no differences found in clinical and radiographic parameters of the two groups before treatment. table 2 & 3 show pli, gi, bop, ppd and cal values (at the base line before treatment & six months after treatment) in the two groups: control group = bop (96% & 37%), gi (1.23 & 0.71), ppd (6.23 mm & 4 mm) cal (8.5 mm & 5.1 mm) significantly improved in both groups. the pi value did not change and the gr value showed statistical significant increase after treatment. study group = bop (91% & 10%), gi (1.12 & 0.21), ppd (7.4 mm & 3.5 mm), cal (8.85 mm & 4.1 mm). table 4 demonstrates the analysis of radiographs six months postoperatively which showed a statistically significant reduction in depth and width of bony defects in both ofd group and (ofd + osteon & ochs) group. tables 5, 6 & 7 reveal the statistical comparisons between the control & study groups in relation to the amount of improvement (the difference between the baseline & 6 months after treatment) of each parameter in both groups. the comparison between the 2 groups showed that the study group parameters at 6 months after treatment were improved significantly more than those of control group except the pli in which the difference was statistically not significant. j bagh college dentistry vol. 25(3), september 2013 evaluation of treatment oral and maxillofacial surgery and periodontics 106 table1. distribution and configuration of bone defects (n = 16 for each group) defect morphology study group control group 3 wall bony defect 12 13 2 wall bony defect 2 1 1 wall bony defect 1 1 circular bony defect 1 1 table 2: pli, bop & gi at baseline and 6 months after treatment parameters (indices) treatment group baseline 6 months pvalue significance pli control group 0.55 ± 0.31 0.47 ± 0.11 > 0.05 ns study group 0.6 ± 0.21 0.52 ± 0.4 > 0.05 ns bop control group 96% 37% < 0.001 hs study group 91% 10% < 0.001 hs gi control group 1.23 ± 0.25 0.71 ± 0.1 < 0.001 hs study group 1.12 ± 0.23 0.37± 0.3 < 0.001 hs table 3: ppd, cal & gr at baseline and 6 months after treatment parameters treatment group baseline 6 months pvalue significance ppd mm control group 6.23 ± 1.1 4 ±1.46 < 0.001 hs study group 7.4 ± 1.9 3.5 ±1.1 < 0.001 hs cal mm control group 8.5 ±2.4 5.1 ±.5 < 0.001 hs study group 8.85 ± 2.1 4.1± 1.4 < 0.001 hs gr mm control group 2.5 ±0.5 2.9 ± 0.3 < 0.05 s study group 1.8 ±0.8 2.96 ±1.2 < 0.05 s table 4: radiographical parameters at baseline and 6 months after treatment parameters treatment group baseline 6 months pvalue significance defect depth control group 3.9 ± 1.6 3.0 ± 1.3 < 0.05 s study group 4.2 ± 1.2 2.1 ± 1.0 < 0.001 hs defect width control group 3.56 ± 0.3 2.7 ± 0.7 < 0.01 s study group 3.8 ± 0.6 1.7 ± 0.6 < 0.001 hs table 5: comparison between control & study groups according to the improvement of parameter values (amount of change between the baseline & 6 months of each group) indices control study tvalue pvalue sig. pli 0.087 0.082 -0.204 0.94 ns gi 0.5 0.91 9.673 0.0126 s bop 59% 81% x2=2.933 0.0217 s table 6: comparison between control & study groups according to the improvement of ppd, cal & gr values (amount of change between the baseline & 6 months of each group) parameters control study tvalue pvalue sig. ppd 2.2 3.9 11.245 0.000 hs cal 3.4 4.75 22.783 0.000 hs gr 0.4 1.16 5.489 0.000 hs table 7: comparison between control & study groups according to the improvement of radiographical parameters (amount of change between the baseline & 6 months of each group) radiographical parameters control study tvalue pvalue sig. defect depth 0.9 mm 2.1 mm 21.675 0.000 hs defect width 0.8 mm 2.1 mm 23.665 0.000 hs j bagh college dentistry vol. 25(3), september 2013 evaluation of treatment oral and maxillofacial surgery and periodontics 107 discussion patient age and teeth with osseous defects treated in both study & control groups were similar at baseline. each subject participating in the clinical investigation demonstrated excellent oral hygiene throughout the entire study. results from this investigation showed that both treatment procedures, resulted in significant clinical improvement in the treatment of intrabony periodontal defects in all clinical and radiographic bone fill between baseline and 6 months. a variety of graft materials have been widely embraced for being used in periodontal regenerative therapy (34). tricalcium phosphate beta (ß-tcp) as a bone graft substitute has been evaluated at length in numerous previous studies. it binds to bone by means of mechanical anchorage with no formation of intermediate apatite layer as well as (ß-tcp) has an important role in gbr procedures, that is, the more solid scaffold of the graft, the more successful the outcome and this property was implemented by the presence of (ßtcp) in the present study (35) . the findings of the current study have showed that the treatment of deep intrabony defects with (ochs plus osteon ii) led to statistically and clinically significant reductions of the periodontal probing depths and clinical attachment level gains in addition to significant reduction of gi, and bop in both treatment modalities. the results of the current study are in agreement with the findings of polat et al (36) & schwarz et al (37) who found promising results resemble those of our study. on the other hand, our results disagree with those of aparna et al (38), they did not find significant differences between odf & ochs). also the findings of the present study showed that the improvement of the evaluated parameters in the study group is higher significantly than control group at 6 months period of the study. the gi & bop values were reduced in study group more than control group could be attributed to antiinflammatory & anti-bacterial properties of the ochs + ß-tcp in addition to the self plaque control procedures. in relation to methodology, the analysis of the results of treatment with the combination of ochs + osteon could be evaluated with regard to the treatment of intrabony defects by mean of the combination of enamel matrix proteins (emd) and bovinederived xenografts or bioactive glasses (39). there are many similarities between the two therapeutical approaches: both single treatment modalities (ochs and emd) are considered to be “biologic”, both products have a fluidity that may require the combination with a bone graft to prevent the collapse of the flaps and both approaches require a good stability of the wound for a favorable outcome (40). beta-tri calcium phosphate (ß-tcp) has been documented so far in a clinical study that has found average ppd reductions of 2.42 ± 2.50 mm & cal gains of 1.25 ± 2.22 mm at 6 months after the treatment of intrabony defects (41). on the other hand, treatment of intrabony defects with ochs alone resulted in an average ppd reduction of 5.33 ± 1.40 mm and a cal gain of 4.4 ± 1.40 mm cal. so, the average cal gains & ppd reductions achieved by ochs are higher than those obtained by using the β-tcp alone (42,43). these results should probably be compensated by the stability of the wound achieved primarily by using the combination ochs + osteon and by increased resorption capacity of the osteon. the relatively marked cal gain noted in this study could testify for the wound-stabilizing effect of the bone replacement material and could emphasize the clinical relevance of the combined therapy. the already described biological and clinical characteristics of ochs and osteon could offer some practical advantages in deep defects when compared with the gtr-technique or with the combination of gtr plus a bone replacement material, when an exposure of the membrane could be a major inconvenient. the combination of ochs and osteon could enhance the improvement of wound healing as well, as reported by the postoperative evolution of the cases. no complications as abscesses or infections occurred postoperatively. however, the effect of the antibiotics on this particular positive outcome cannot be excluded. antibiotics are being prescribed in most of the clinical studies on regenerative periodontal therapies; however, the literature has no defined position on the influence of the antibiotic adjunctive postoperative medication (44). more clinical controlled studies are needed to determine the necessity of postoperative antibiotics following regenerative periodontal treatments. more histological studies are also needed in order to determinate if the observed clinical results represent a true periodontal regeneration rather than a simple defect fill. as a conclusion, the results of the current study showed that treatment of deep intrabony defects using an ochs combined with osteon ii resulted in a statistically and clinically significant reduction of the gi, bop, ppd and cal gain and reduction of the size of the treated intrabony defects. the absence of allergic or infectious reactions indicates that the combination of the two materials is stable and well tolerated, in j bagh college dentistry vol. 25(3), september 2013 evaluation of treatment oral and maxillofacial surgery and periodontics 108 addition to the benefits from the antiinflammatory and possible osteostimulative action of the oily suspension of calcium hydroxide. the use of osteon ii was beneficial due to its roles in serving as scaffold for ochs and its osteoinductive activity. references 1. pretzl b, kaltschmitt j, kim ts, reitmeir p, eickholz p. tooth loss after active periodontal therapy. 2: tooth-related factors. j clin periodontol 2008; 35(2):175-182. 2. neoman mg, takei hh, carranza fa. carranza's clinical periodontology. 11th ed. saunders; 2012. p. 482-90. 3. reddy s. essentials of clinical periodontics and periodontology. jaypee brothers medical publishers (p) ltd; 2011. 4. cortellini p. reconstructive periodontal surgery: a challenge for modern periodontology int dent j 2006; 56(suppl 1): 250–5. 5. cortellini p, tonetti ms. clinical and radiographic outcomes of the 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calcium hydroxide suspension. a case seriesnov. 15, 2004. revised: dec. 3, 2004. 34heijl l, heden g, svardstrom g, et al. enamel matrix derivative (emdogain®) in the treatment of intrabony periodontal defects. j clin periodontol 1997; 24: 70514. 35trisi p, rao w, rebaudi a, fiore p. histologic effect of purephase beta-tricalcium phosphate on bone regeneration in human artificial jawbone defects. int j periodont restor dent 2003; 23: 69-77. 36polat hb, yeler h, et al. effect of oil-based calcium hydroxide (osteoinductal) on distraction osteogenesis in rabbit mandible. oral surg oral med oral pathol oral radiol endod 2009; 107(6): e30-6. 37-schwarz f, stratul si, herten m, beck b, becker j, sculean a. effect of an oily calcium hydroxide suspension (osteoinductal) on healing of intrabony periodontal defects. a pilot study in dogs. clin oral investig 2006; 10(1): 29-34. 38aparna s, swati s, srinath t. oily calcium hydroxide suspension in the treatment of infrabony periodontal defects: a randomized controlled clinical trial quintessence international 2011; 42(10): 835 39sculean a, barbé g, chiantella gc, et al. clinical evaluation of an enamel matrix protein derivate combined with a bioactive glass for the treatment of intrabony periodontal defects in humans. j periodontol 2002; 73: 401-8. 40sculean a, windisch p, keglevich t, et al. clinical and histologic evaluation of human intrabony defects treated with an enamel matrix protein derivative combined with a bovine-derived xenograft. int j periodontol and rest dent 2003; 23: 47-55. 41baldock wt, hutchens lh jr, mcfall wt jr, et al. an evaluation of tricalcium phosphate implants in human periodontal osseous defects in two patients. j periodontol 1985; 56: 1-7. 42.saffar jl, colombier ml, detienville r. bone formation in tricalcium phosphate-filled periodontal intrabony lesions. histological observations in humans. j periodontol 1990; 61: 209-216. 43stratul s, sculean a. oily calcium hydroxide plus alpha-tcp in treating intrabony defects. j clin periodontol 2003; 30(suppl. 4): 71. poster 273. 44. cortellini p, pini prato g, tonetti ms. periodontal regeneration of human infrabony defects. i. clinical measures. j periodontol 1993; 64: 254-60. balkees f.doc j bagh college dentistry vol. 25(2), june 2013 oral signs and symptoms oral diagnosis 59 oral signs and symptoms and hyperglycemic status of type ii diabetic patients in relation to cytomorphometric findings of gingival and buccal cytobrush smears mohammad t. baban, b.d.s., m.sc. (1) balkees t. garib, b.d.s., m.sc., ph.d. (2) abstract background: brush cytology is an accepted technique that gets renewed interest. it is now used as an aid for the diagnosis and observation of possible epithelial changes that could be associated with oral mucosal diseases. this study aimed to evaluate the cytomorphometric changes in gingiva and buccal mucosa of type ii diabetics and to assess their relation to oral symptoms and glycemic status. materials and methods: cytological papanicolaou stained smear were prepared from cheek and gingiva of 20 non treated cases, 20 treated diabetics and 20 healthy persons of both sex after measuring their hba1c and recording their oral symptoms. hundred unfolded epithelial cells were evaluated qualitatively using mcid software to measure nuclear and cytoplasmic areas, ratio, perimeters, and form factors. different statistical analyses were used to determine relations between studied parameters. results: diabetics smears showed large nucleus, small cytoplasm, and small cytoplasm/nucleus ratio compared with healthy persons with no sex variation. xerostomia and burning sensation were significantly correlated with nuclear parameters, while hba1c was significantly correlated with both cytoplasmic and nuclear parameters. well-controlled patients showed reduction in nuclear area, but nucleus and cytoplasm form factors were unlike normal. conclusions: oral cytology from type ii diabetics is associated with detectable cytomorphometric changes that is better demonstrated in buccal than gingival mucosa and tend to return partially to their normal values in wellcontrolled patients, with no sex variation. na seems to be the main parameter that changed during hyperglycemia and xerostomia, while both na and ca were related to burning sensation. key words: type ii diabetes mellitus, cytomorphometry, gingiva, xerostomia. (j bagh coll dentistry 2013; 25(2):59-65). introduction diabetes mellitus (dm) is the most common metabolic disorder that produces multiple systemic complications (1) with multiple etiologies characterized by chronic hyperglycemia with disturbances of carbohydrate, fat and protein metabolism (2). type ii dm accounts for 9095% of persons with diabetes most of them are adults older than 40 years, but it becomes more common in obese adolescents and children (3) poorlycontrolled diabetics are associated with oral health complications include gingivitis, periodontitis, salivary gland dysfunction, dental caries, burning mouth sensation, taste disturbances, infections (oral candidiasis) and mucosa changes (4,5). thus dentist has a major role in 1) screening and diagnosis of undiagnosed patients, 2) proper dental management of oral manifestations and 3) prevention of systemic and local complications (6,7). several clinical and paraclinical techniques are available for screening of oral mucosal changes and oral cytology is one of the appropriate method in identifying high risk population or for clinical follow up (8). (1)shorish dental teaching center, sulaimani, iraq. (2)professor. faculty of medical sciences, school of dentistry, university of sulaimani / iraq. oral cytology is a relatively inexpensive, simple, noninvasive, and risk-free technique that is well accepted by the patient (9). and with the application of cytobrush sampling, advance technology and immuno-/genocytochemistry there was much improves in the potential accuracy of oral cytology (10-12). concerning cytomorphology of oral mucosa in type ii dm, few published literatures described changes in buccal mucosal collected by different methods without specification of patient’s hyperglycemic status (13-15). however, prasad et al (16) in 2010, declared that point; but they neglected treatment and site variation. later on in 2011, hallikerimath et al. studied cytomorphological changes and glycogen content in exfoliated cell from buccal mucosa (17). therefore, the goal of our study was to identify the quantitative nuclear and cytoplasmic changes of both buccal and attached gingiva in type ii dm at different hyperglycemic status (uncontrolled, well controlled and poorly controlled) whether they were treated or untreated and assess their relation with xerostomia, burning mouth sensation and oral ulceration. materials and methods in a cross-sectional study, a total of 40 type ii dm patients were collected from ali naji dispensary clinic in sulaimani city from feb. to aug. 2009, so that 20 of them were newly j bagh college dentistry vol. 25(2), june 2013 oral signs and symptoms oral diagnosis 60 undiagnosed cases and 20 were receiving metformin therapy 500mg (tid) for not less than 1 year. according to their hba1c levels (which indicates the degree of glycemic control achieved), they were subdivided into 3 groups; uncontrolled (hba1c >12%), well-controlled (hba1c ≤8%) and poorly controlled (hba1c >10% and ≤12) (16). the control group included 20 non-diabetic healthy volunteers with no risk factor for diabetes and their hba1c< 6.5%. all participants’ age ranged between 40-50 years. the exclusion criteria were: 1) smoker (18-19) or alcoholic (20) patients, 2) systemic diseases or other medications that affect the assay (21), and 3) ladies who were pregnant or during menstrual period or taking contraceptives (22) . the study was approved by the local ethical committee and all patients signed a written consent form. patient’s name, age, sex, medical history, presence of burning mouth sensation (oral mucosal pain related to dm and not to other medical or dental cause) and xerostomia (subjective feeling of oral dryness) as described by the patients were recorded. oral ulceration (presence of mucosal discontinuity) was assessed clinically by specialist using mouth mirror and under good light vision). the participants were asked to gargle with tap water. the oral mucosa was dried with gauze to remove surface debris and excess saliva. two smears were collected, one from the buccal mucosa and the other from upper anterior attached gingiva of each individual using oral cytobrush (rover orcellex/ netherlands) and transferred to labeled, clean, dry glass slides. they were then fixed at once by soaking in 95% ethanol and stained by papanicolaou stain. for each individual (without identify his group) 100 unfolded, clearly outlined, separated cells (50 from buccal and 50 from attached gingiva) were selected manually by moving the slide in a stepwise manner (from upper left corner to the right and then downwards and going back in reverse direction in order to avoid measuring the same cells again) and their images were captured: using digital microscope camera (moticam 2000/china) attached to olympus microscope at power 100x (figure-1a). these images were transferred to a computer by using motic images plus 2.0ml software. they were changed to gray scale and from jpeg format to tiff format using adobe photoshop cs2. the cytomorphometric measurements; the nuclear and cytoplasmic areas (na, ca), perimeters (np, cp), ratio (na/ca) and form factor (a standard estimate of circularity that relates perimeter length to area; nf, cf) were determined by using auto image segmentation that identifies their boundaries pixels using mcid image analysis software (figure-1b). raw data were collected, tabulated, and analyzed using spss software (version 16.0). the cytomorphometric parameters were represented as mean ± sd, while the clinical parameters (sex, xerostomia, burning sensation, oral ulceration and glycemic status) were presented as frequency and percentages distribution. one way anova-test followed by multiple comparisons test (post hoc test) were applied to identify the significance among different studied group. independent student’s t-test was applied to compare between sites as well as sex variations. bivariate person’s correlation was used to determine the relationship between studied parameters. the level of significance was set at p≤0.05. results the number of subjects in each treated and non treated groups according to their hba1c were distributed in relation to sex and oral symptoms are illustrated in table-1. the well controlled group included 20 patients (12 treated and 8 nontreated) and 50% of them were suffering from xerostomia, while the poorly controlled group included 14 patients (8 treated and 6 non-treated) and xerostomia was more frequent in non-treated patients (5 out of 6; 83.3%). furthermore, the uncontrolled group included only 6 non-treated undiagnosed patients and all of them complain from xerostomia. lastly treated patients described more frequently the feeling of burring mouth sensation than non-treated group regardless of their glycemic status, (table 1). statistical analysis showed that hba1c correlated significantly with both xerostomia (r=0.63, p=0.000) and burning sensation (r=0.38, p=0.002). concerning cytomorphometric measurements in relation to site variation, buccal mucosa had significantly larger ca, cp, cf and ca/na than gingival cells, both in healthy and well control treated patients (table 2 and 3). the remaining dm groups maintain only the significant large cf and ca/na in buccal mucosa. on the other hand, na and np of healthy persons did not show site differences, nevertheless, in buccal smear of uncontrolled and poorly control treated patients nuclear areas were slightly larger (p>0.05) than that of gingiva, and a reverse findings is reported in well-controlled groups (in both treated and non treated groups; i:e nuclear areas of buccal mucosa were smaller than gingiva) (table 3). the cytological smear obtained from oral mucosa of all dm subgroups in comparison to control group, at both sites, had significant larger j bagh college dentistry vol. 25(2), june 2013 oral signs and symptoms oral diagnosis 61 na, np and significant smaller ca/na. furthermore, the uncontrolled non-treated patients had significantly small ca and cp in gingival smears. thus, the ca/na reaches half the ratio of that of control subjects (p=0.000) (25.15 vs. 50.84). while all treated dm patients showed significantly larger cf at the buccal mucosa (0.75 in well controlled and 0.76 in poorly controlled) (table 2 and 4). no sex variation was observed in all measured parameters (data not shown). regarding the differences among dm subgroups in relation to their hyperglycemic control and therapy status, statistical analysis indicated no significant variation in nuclear measurements, despite that na was reduced in relation to hba1c level, especially in buccal mucosa. thus dm patients with hba1c ≤8 had smaller na (58.42) in comparison to both poorly controlled (64.66) and uncontrolled (64.46) groups, and it became even smaller with therapy (i.e. in well controlled treated group 55.95) (table2 and 4). the buccal smears from poorly treated patients had larger cellular form factor (cf) measurements than non treated patients; both poorly controlled and uncontrolled (0.76 vs 0.73 and 0.74 respectively). thus, changes in cf in diabetic patients vary from polygonal or oval or elliptical to circular in the following sequence healthy person > undiagnosed dm patients > treated patients, especially poorly controlled treated patients at buccal cells. beside that uncontrolled patients had smaller ca/na ration (29.14) than poor-controlled non-treated patients (37.69), well controlled treated (43.2) and well controlled nontreated patients (40.09), while the np was smaller in well controlled treated patients than poorly controlled treated. on the other hand, cells collected from gingival mucosa demonstrated that well treated patients had smaller nf (0.879) than non treated patients (both wellcontrolled 0.898 and poor-controlled 0.895). however these variations did not reach statistical significant level (table 2). all the studied variables did not show sex variation (data not shown). the correlation between cytomorphological parameters on one hand, the hba1c and oral symptoms on the other hand, results showed that the levels of hba1c was significantly correlated with cytoplasmic and nuclear parameters (area and perimeter); it had highly significant negative correlation with ca/na ratio in both studied sites (gingival and buccal mucosa, r=0.7, r= 0.62 respectively) (table-4). on the other hand, xerostomia and burning sensation correlated significantly with na, np and ca/na ratio. furthermore, the ca and cp of the buccal mucosa were related significantly to the burning sensation. finally, ulceration had significant week correlation only with ca and cp at buccal mucosa (table-5). discussion oral conditions that are possibly seen in individuals with diabetes may include burning mouth, altered wound healing, an increased incidence of infection, and xerostomia (4,7) . in this study the frequency of xerostomia was increased as glycate hemoglobin level increased, especially in non treated patients. however, half of our patients who keep hba1c level at ≤8 were suffering from xerostomia irrespective to the stat of therapy. on the other hand, burning mouth had weak correlation with hba1c level and is more frequently reported in treated dm patients. thus any observed changes in oral cytomorophology of well controlled dm may possibly attribute to therapy effect. therefore, we further subdivided our non treated patients according to their hba1c level into 3 groups to be compared with those corresponding treated groups. from histological point of view, the oral cavity is lined by different types of stratified squamous epithelia. the regional differences in the patterns of epithelial maturation appear to be associated with different turnover rates; thus non-keratinized buccal epithelium turns over faster than keratinized gingival epithelium. since such variations are clinically reflected by both; in the more rapid appearance of changes and in the prevalence of damage to non-keratinized rather than to keratinized surfaces (23), we compared buccal mucosa that had been frequently studied in previous researches with the gingiva to be studied for the first time in dm patients. previous study using cytobrush smear indicated that normal non-keratinized buccal mucosa had larger cytoplasmic and nuclear areas than floor of the mouth and the dorsum of the tongue (13). in this study, normal gingival mucosa also had smaller cytoplasmic measurements than buccal mucosa, but they had nearly equal nuclear measurements. in fact cytoplasmic variation could be related to differences in cell turnover rate and maturation stage (23), beside the effect of existence of local inflammation (24). accordingly one expects to see the herein the reported greater reduction in na at non-keratinized mucosa of well-controlled treated dm in response to therapy. the present study showed that cytomorphometric measurements were not related to sex variation. this is in line with prasad et al (16) and cowpe et al (25). nevertheless, patel et al (22) mentioned that hormonal changes during j bagh college dentistry vol. 25(2), june 2013 oral signs and symptoms oral diagnosis 62 menstruation, pregnancy and taking contraceptive pills can affect the results; anyhow we exclude such patient from our studied sample. oral mucosal cells from dm patients in general had significantly large nucleus (na, np) and small ca/na ratio and had a tendency to be small in size (ca, cp) when compared with control, this agrees with most previous studies (13,14,16,17) and only contradicts jajarm et al findings for ca (15) . this variation could be attributed to the difference in the procedure of tissue sample collection, as they collected cells by lancet that scribed more superficial cells. such procedure is considered to be inferior in the cytology of oral mucosa in comparison to brush technique (26) which is specially designed to access all epithelial layers. our findings demonstrate that there is a real increase in nuclear measurements related to hyperglycemic status in type ii dm that; it was greatest in poorly controlled group and smallest in well controlled treated group, and this was better demonstrated in buccal mucosal cells than gingival. this result bridges prasad’s et al findings (16) concerning glycemic condition and alberti’s et al. results (13) concerning site variation. although morphological changes in oral mucosa may be related to many variables (18-22), here in diabetes it may be related to the metabolic control of the diabetic state and medication beside the previous reported factors that related to the reduction in; epithelial nourishment (2), proliferation and turnover secondarily to microvascular and metabolic disorders (27) that may accompanied with reduction in the stimulatory effect of insulin and igf-i on keratinocytes (28). furthermore diabetics are commonly suffering from xerostomia that may alter oral mucosa and predisposing them to microbial colonization with critical reduction in salivary lubricant effect. this lead to atrophic oral mucosa or ulceration (2,7) that showed cells with large na which may indicate more basal and parabasal cells. however such finding need to be related to cellular morphological features as prasad et al (16) suggested that an increase in nuclear size with nuclear pleomorphism, bilobed nuclei, and cytoplasmic vacuolizations in dm may related to cellular ageing, which resulted from reduction in cellular turnover and persistence of more number of mature cells. in addition to that, oral cytomorphologic findings from dm patients showed evidence of buccal mucosa keratinization (29). concerning the glycemic status and treatment condition, the uncontrolled patients showed reduction in ca and cp in both site and it was significant in gingival smears. this is in line with prasad’s et al (16) finding who reported similar reduction in cytoplasmic diameter of buccal mucosa smear. however, alberti et al did not find significant differences in ca among tongue, floor of the mouth and buccal mucosa (13). oral anti-diabetic drug, metformin had been shown to stimulate apoptosis in addition to its anti-proliferative action (30-31) . in this study it had noticable effect on cytoplasm and nuclear form factors of buccal and gingival mucosa respectively. thus well-controlled treated diabetics expressed more irregular nuclear shape and circular cell shape in comparison with other dm subgroups. this could be attributed, to some extent, to the well known side effect of metformin in producing lacto acidosis (32) that is believed to cause cellular swollen and coarsen of the nuclear chromatin (33). in this context nf is a suggested quantitative parameter for nuclear functions, aging or death. it is interesting to report strong correlations between hba1c and oral symptoms on one hand and cytomorphometric parameters on the other hand. accordingly, the level of hba1c was highest in patient who their oral smears showed largest nuclear measurements and smallest cell size. on the other hand, na seems to be the main parameter that changed during xerostomia. while both na and ca were related to burning sensation, that associated with small cells and large nucleus, which is a predominant finding in gingival smears. finally, mucosal ulceration was only related to large ca which observed more in buccal mucosa. although some of the above findings are not unique for dm and larger sample may provide better results, still this work provides us with another profile about oral mucosal changes and their response to therapy in dm that may have clinical implications in public health. it is extremely beneficial to determine the severity of the dm and the degree of control of glycemia, but the glycated hemoglobin assay is not currently recommended as a screening tool or as an initial test for the diagnosis of diabetes. it is used to monitor glycemic control in patients with previously diagnosed diabetes. therefore, dentist can use cytology as additional tool in the clinic for screening and referral for diagnosis of previously undiagnosed patients after thorough review of the patient’s health history and oral examination, or uncontrolled dm patients and explains the associated oral manifestations to them as well as to seek possible measurements to prevent local complications. j bagh college dentistry vol. 25(2), june 2013 oral signs and symptoms oral diagnosis 63 as a conclusion cytomorphometric results of healthy gingival mucosa had smaller cytoplasmic but nearly equal nuclear measurements in comparison with buccal mucosa. however, this picture is altered in dm patients. they showed detectable cytomorphometric changes that not related to sex variation. such changes were better demonstrated in buccal than gingival mucosa. the altered cytoplasmic and nuclear measurements tend to return partially to their normal values in well-controlled patients. na seems to be the main parameter that changed during hyperglycemia and xerostomia, while both na and ca were related to burning sensation. lastly, cf and nf are suggested as quantitative parameters to be assessed in dm oral smears. references 1. maitra a. the endocrine system/pancreas. in kumar v, abbas a, fausto n, mitchell rn (eds): robbins basic pathology. 8th ed. philadelphia: elsevier saunders; 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60: 232-240. a b figure 1: a -digital camera mounted on light microscope and connected to personal computer. bpicture of mcid software during segmentation of a cell and its nucleus (the measurements appear at the left side). table 1 frequency and percentage distributions of healthy subjects and type ii dm patients according to their hba1c in relation to sex and oral symptoms group hba1c subgroup total male female xerostomia burning ulcer no % no % no % healthy <6.5 total 20 6 14 0 0 1 5 2 10 dm ≤8 non treated 8 5 3 4 50 1 12.5 2 25 treated 12 4 8 6 50 3 25 3 25 >10≤12 non treated 6 3 3 5 83.3 1 16.7 1 16.7 treated 8 6 2 5 62.5 3 37.5 2 25 >12 non treated 6 4 2 6 100 4 66.7 1 16.7 table 2: the mean± sd values of cytomorphometric parameters in control and type ii dm patients according to their hba1c in relation to treatment at buccal and gingival mucosa parameter group control non treated dm treated dm hba1c site <6.5 >12 ≤8 >10 ≤12 ≤8 >10 ≤12 ca (µrn2) buccal 2346.9±501.06 1796.6± 359.09 2174.2 ± 540.30 2272.7 ± 641.49 2235.9 ± 439.84 2157.9 ± 578.83 gingiva 1843.6±368.26 1420.6± 282.48 172.45 ± 266.75 1708.7 ± 322.58 1618.2 ± 244.77 1748.0 ± 310.03 cp (µrn) buccal 200±22.4 174.23± 15.79 192.23 ± 26.049 196.61 ± 29.31 1917.7 ± 19.61 187.18 ± 25.26 gingiva 182.28±16.57 159.30± 15.17 174.48 ± 14.21 174.43 ± 16.30 168.26 ± 14.39 175.23 ± 14.23 cf buccal 0.729±0.032 0.741 ± .021 0.741 ± .032 0.734 ± .019 0.757 ± .026 0.765 ± .0164 gingiva 0.698±0.043 0.703 ± .013 0.714 ± .021 0.706 ± .022 0.723 ± .030 0.719 ± .0267 na (µrn2) buccal 39.58±8.28 64.46 ± 15.05 58.42 ± 7.41 64.88 ± 12.15 55.95 ± 7.98 64.66 ± 11.00 gingiva 39.7±10.83 58.28 ± 7.12 61.32 ± 9.62 66.52 ± 10.13 59.58 ± 8.16 62.72 ± 6.12 np (µrn) buccal 23.59±2.53 30.27 ± 4.05 28.76 ± 1.91 30.41 ± 2.81 28.15 ± 2.20 30.47 ± 2.70 gingiva 23.63±3.11 28.85 ± 2.15 29.39 ± 2.44 30.65 ± 2.45 29.31 ± 2.12 29.95 ± 1.52 nf buccal 0.891±0.018 0.891 ± .034 0.892 ± .012 0.884 ± .021 0.89 0± .015 0.879 ± .0169 gingiva 0.887±0.026 0.891 ± .029 0.898 ± .015 0.895 ± .012 0.879 ± .016 0.886 ± .0192 ca/na buccal 63.81±13.38 29.14 ± 3.37 40.09 ± 10.22 37.69 ± 7.56 43.21 ± 10.60 34.98 ± 6.241 gingiva 50.84±9.12 25.15 ± 3.12 29.65 ± 4.79 27.03 ± 3.95 28.18 ± 3.349 28.95 ± 4.430 abbreviations: diabetes mellitus(dm), hemoglobin a1c (hba1c), nuclear area (na) cytoplasmic area (ca), nuclear perimeter (np), cytoplasmic perimeter (cp), nuclear form factor (nf), cytoplasmic form factor (cf), ratio of cytoplasmic to nuclear areas (ca/na) j bagh college dentistry vol. 25(2), june 2013 oral signs and symptoms oral diagnosis 65 table 3. the results of significant independent ttest for the differences in cytomorphometric parameters between buccal mucosa and gingiva in all md groups and control. control well-controlled poor-controlled uncontrolled no. 20 6 12 6 8 8 df=38 non-treated df=14 treated df=22 non-treated df=10 treated df=14 non-treated df=10 t sig t sig t sig t sig t sig t sig ca -3.619 .001 -2.11 .053 -4.251 .000 cp -2.87 .007 -3.348 .003 cf -2.622 .012 -2.954 .007 -2.296 .045 -4.121 .001 -3.607 .005 ca/na -3.583 .001 -2.615 .020 -4.679 .000 -3.057 .012 -2.229 .043 -2.128 .059 table 4: multiple comparison for the mean values of cytomorphometric parameters among all studied groups at both sites using one-way anova and post hoc test /bonferroni procedure pa ra m et er site one-way anova post hoc test well-controlled poor-controlled uncontrolled non-treated treated non-treated treated non-treated f sig. mean difference sig. mean difference sig. mean difference sig. mean difference sig. mean difference sig. ca gingiva 1.97 0.08 423.11 .05 cp gingiva 2.58 .036 22.98 .026 cf buccal 2.68 .031 -.0274 .009 -0.0354 .04 na gingiva 15.23 .000 -21.62 .000 -19.88 .000 -26.81 .000 -23.01 .000 -18.58 .001 buccal 14.02 .000 -18.84 .000 -16.37 .000 -25.30 .000 -25.08 .000 -24.88 .000 np gingiva 15.14 .000 -5.75 .000 -5.68 .000 -7.01 .000 -6.32 .000 -5.22 .001 buccal 14.16 .000 -5.17 .000 -4.56 .000 -6.81 .000 -6.87 .000 -6.68 .000 ca/na gingiva 35.67 .000 21.19 .000 22.65 .000 23.80 .000 21.88 .000 25.69 .000 buccal 17.66 .000 23.72 .000 20.60 .000 26.12 .000 28.83 .000 34.67 .000 table 5: the significant values of the bivariate pearson’s correlation (r) for clinical symptoms and hba1c with different cytomorphometric parameters for both buccal mucosa and gingiva. abbreviations: hemoglobin a1c (hba1c), nuclear area (na) cytoplasmic area (ca), nuclear perimeter (np), cytoplasmic perimeter (cp), ratio of cytoplasmic to nuclear areas (ca/na) site parameters ca cp na np ca/cn g in gi va hba1c pearson correlation -.330* -.365** .433** .430** -.601** sig. (2-tailed) .010 .004 .001 .001 .000 burning pearson correlation .334** .331** -.319* sig. (2-tailed) .009 .010 .013 xerostomia pearson correlation -.272* .489** .498** -.587** sig. (2-tailed) .036 .000 .000 .000 b uc ca l hba1c pearson correlation .615** .609** -.639** sig. (2-tailed) .000 .000 .000 burning pearson correlation -.315* -.336** .330* .339** -.464** sig. (2-tailed) .014 .009 .010 .008 .000 xerostomia pearson correlation .640** .642** -.577** sig. (2-tailed) .000 .000 .000 ulcer pearson correlation -.260* -.279* -.319* sig. (2-tailed) .045 .031 .013 *. correlation is significant at the 0.05 level (2-tailed). **. correlation is significant at the 0.01 level (2-tailed). j bagh college dentistry vol. 29(2), june 2017 dental caries severity pedodontics, orthodontics and preventive dentistry 115 dental caries severity in relation to selected salivary variables among a group of pregnant women in baghdad city/iraq. nadia qasim mutlak, b.d.s. (1) baydaa ahmed yas, b.d.s., m.sc., ph.d. (2) abstract background: during pregnancy many physiological, anatomical and biochemical changes take place that affect almost all body systems. in the oral pregnant women have serious changes such as more sever dental caries. this study was conducted to measure dental caries severity and selected salivary variables (salivary flow rate, ph and viscosity)and to find the relation of dental caries with these salivary variables. subjects, materials and methods: the study group consisted of 60 pregnant women that were divided into three equal groups according to trimester (20 pregnant women in each trimester).they were selected randomly from the maternal and child health care centers in baghdad city, the age range was 20-25 years. in addition to 20 unmarried women as a control group and matched with age. stimulated salivary samples were collected .then salivary flow rate, ph and viscosity were measured. dental caries severity was recorded by using decay, missing and filled index (d1-4mfs) using the criteria described by manjie et al, (1989). plaque index system by silness and löe, (1964) was used for measuring dental plaque thickness. for measuring dental calculus the calculus index component of the periodontal diseases index (pdi) by ramfjord (1959) was used. results: results of the current study revealed that dental caries parameter represented by (dmft ,dmfs,ds and ms) were higher among pregnant than non –pregnant women with significant differences (p<0.05) for dmft,dmfs and ds also all grades of lesion severity(d1-4)were higher among pregnant than non –pregnant women with nonsignificant differences(p>0.05).almost all dental caries parameter were higher in the 2nd trimesters with highly significant difference (p<0.01) for d1,ds ,dmfs and dmft among four groups . concerning oral cleanliness both plaque and calculus indices recorded higher values among pregnant than nonpregnant with highly significant difference for both (p<0.01). values were higher during 2nd trimester with high significant and non-significant differences among four groups .regarding the relations of dental caries with oral cleanliness ,it was found that all dental caries parameters recorded positive correlations with both plaque and calculus indices with significant and highly significant relations regarding salivary variables ,results revealed that salivary flow rate was higher among pregnant (especially in the 2nd trimester)than non-pregnant women but with non-significant difference (p>0.05).on the other hand salivary ph value was lower among pregnant than nonpregnant women with highly significant difference (p<0.01)among them. salivary ph was lowest in the 2nd trimester with highly significant difference (p<0.01) among four groups .also salivary viscosity was higher among pregnant than non-pregnant women with highly significant difference (p<0.01) and it recorded higher mean value in the 3rd trimester with highly significant difference among four groups (p<0.01). salivary ph recorded inverse relation with almost all dental caries parameters with significant relations with d4, ms and highly significant relations with ds,dmfs and dmft ,while salivary flow rate and salivary viscosity revealed non-significant relations with dental caries parameters (p>0.05). conclusion: dental caries severity was higher among pregnant women probably due to the effect of pregnancy itself on oral hygiene (higher plaque and calculus indices) and salivary variables (increased salivary acidity and viscosity).therefore, intensive education and preventive programs should be directed for pregnant women. key words: dental caries, pregnancy, salivary viscosity. (j bagh coll dentistry 2017; 29(2):115-121) introduction pregnancy is a physiological process that affects even healthy women and involves many physiological, biochemical and anatomical changes (1, 2). in addition to noticeable oral changes among them is an increase in dental caries severity (3-5). dental caries is an infectious transmissible bacterial diseases caused by acid from bacterial metabolism diffusing into enamel and dentine and dissolving the mineral (6). several studies recorded an increase in dental caries severity among pregnant women (7-9). (1) master student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (ministry of health) (2) assistant professor, depart ment of pedodontics and preventive dentistry, college of dentistry, university of baghdad. in iraq comparison studies had been carried out and recorded an increase in dental caries among pregnant in comparison to non-pregnant (10-13). a longitudinal study was found that recorded an increase in dmft and dmfs during pregnancy but a decrease in decay severity ds from initial 2.58 to 1.54 before labor by papp et al (14). some pregnant women might experience excessive salivation (i.e. ptyalism) (15, 16) on the other hand xerostomia or hypo-salivation was reported to be a frequent complaint among pregnant women. al taie( 17) found the flow rate of resting and stimulated saliva were significantly higher in pregnant than control group. while suliaman( 10) showed that stimulated salivary flow rate was significantly reduced among pregnant women and al-zaidi (12) reported no statistically j bagh college dentistry vol. 29(2), june 2017 dental caries severity pedodontics, orthodontics and preventive dentistry 116 significant difference between pregnant and control group also salivary ph is affected during pregnancy. kivela et al,( 18) reported a decrease in salivary ph during pregnancy followed by rapid and significant increase after delivery .while in iraq al-zaidi (12) found statistically non significant difference of salivary ph, among pregnancy trimesters as compared to control. laine and pienihakkinen, (19) reported a decrease in salivary ph during pregnancy. regarding salivary viscosity fresh mixed human saliva is viscoelastic fluid with distinct surface activity (20). during pregnancy. however, study in blood viscosity during pregnancy could be fond (21). these changes in salivary flow rate, ph and salivary viscosity during pregnancy might increase dental caries severity among them (10, 22, 24). however limited studies could be found regarding changes in salivary flow rate and ph during pregnancy while no studies could be found that measure salivary viscosity among pregnant women. therefore it was decided to carry out this study to assess dental caries severity in addition to salivary flow rate, ph and viscosity among pregnant women in comparison to un-married women and to evaluate the relation of salivary flow rate, ph and viscosity with dental caries severity. subjects, materials and methods the study group consisted of (60) pregnant women that were divided according to trimester into three equal groups (20 pregnant women in each trimester). the age range was 20-25 years. in addition to 20 un married women as a control group, these women should be matched with age both pregnant and control women were selected randomly from the maternal and child health care centers in baghdad city. stimulated salivary samples were collected according to tenovuo and lagerlof (25) instructions. after saliva collection the ph was measured by using digital ph meter. salivary volume was measured by using measuring cylinder and the rate of secretion was expressed in milliliter per minute (ml/min).salivary viscosity was determined by using the ostwald viscometer (u-type viscometer)(26).then salivary samples were centrifuged and stored at (-20oc) for subsequent chemical analysis. plaque index by silness and löe, (27) was used for measuring dental plaque thickness. for measuring the amount of dental calculus, calculus index (cal i) component of the periodontal diseases index (pdi) by ramfjord, (1959)(28) was used, and all teeth was diagnoses dental caries experience was recorded by lesion severity according to decay, missing and filled index (d1-4 mfs) index according to criteria described by manjie et al., (1989)(29). statistical analyses were done by using ibm spss version 23 computer software (statistical package for social sciences) in association with microsoft excel 2016. results table (1) showed that dental caries parameters (dmfs), (ds) were higher among pregnant than non-pregnant women (mean 17± 9.5; mean 9± 5.5) respectively with significant differences (p<0.05) in the 2nd trimester. while missing surfaces (ms) recorded higher mean rank value among pregnant than non-pregnant with significant difference (p<0.05) (ms) was higher in the 1st trimester of pregnancy. data showed that all grades of caries severity (d14) were higher among pregnant than non-pregnant but with non-significant differences (p>0.05). according to trimester all grades (d1,d2,d4) of severity were higher in the 2nd trimester except for d3 that was higher in the 3rd trimester with highly significant difference among the four groups for d1 only(p<0.01). statistical difference in ms between pregnant and non-pregnant (u test=414.0, z value=-2.293, p value =0.022*) statistical difference in ds between pregnant and non-pregnant (t-test=-2.26, d.f=78, p value =0.027). statistical difference in dmfs between pregnant and non-pregnant (t test=-2.46, d.f =78, p value=0.016). table (2) show that both pl i and cal i values were higher in the second trimester with highly significant difference among four groups for plaque (p<0.01) and for calculus index the p-value was close to the confidence limit. statistical difference in plaque index between pregnant and non-pregnant (u test=238.5, z value =-4.017, p value<0.001; statistical difference in calculus index between pregnant and non-pregnant (u test=414, z value =-2.076, p value<0.001) in table (3) salivary flow rate was higher in pregnant than non-pregnant in the 2nd trimester but with non-significant difference among four groups (p>0.05). salivary ph was lower (more acidic) among pregnant than non-pregnant with highly significant difference (p<0.01). salivary ph was lower in the 2nd trimester with highest significant difference among four groups. salivary viscosity was higher among pregnant women than non-pregnant with high significant differences (p<0.01). it was higher in the 3rd trimester with highly significant difference among four groups (statistical difference in ph between pregnant and non-pregnant women (f=5.464, d.f j bagh college dentistry vol. 29(2), june 2017 dental caries severity pedodontics, orthodontics and preventive dentistry 117 =1, p<0.01) statistical difference in viscosity between pregnant and non-pregnant women (f= 7.687, d.f =1, p=0.006). table (4) revealed that statistical significance was significant (p<0.05) and highly significant for both plaque and calculus index with (dmft, dmfs, ds, ms) of dental caries parameters. the relation of dental caries parameters with salivary physico-chemical characteristic are shown in table (5) it was found that the relation of salivary flow rate with dental caries parameters were weak nonsignificant correlations (p>0.05).salivary ph revealed weak inverse relations with dental caries parameters except for (fs) that was weak positive relations statistical significance were significant (p<0.05)for(d4)-and highly significant (p<0.01) for (ds, ms, dmfs, dmft). salivary viscosity revealed weak non-significant (p>0.05) correlations with dental caries parameters. the effect of pregnancy on oral variables analyzed by using (roc test) is shown in table (6) also adverted in fig. (1,2). results showed that the most affected oral variables by pregnancy was salivary (ph) with highly significant difference (p<0.05). followed by pl i gi (salivary viscosity). table 1: dental caries experience among nonpregnant and pregnant women according to trimester. statistical differences among four groups (anovas test) total (pregnant women) 3rd trimester 2nd trimester 1st trimester non pregnant women parameters p -value d .f c hisquare m ean rank m edian n o. m ean rank m edian n o . m ean rank m edian n o . m ean rank m edian n o. m ean rank m edian n 0. 0.001** 3 16.26 40.6 3 60 39.5 3.5 20 55.9 7 20 26.5 1.5 20 40.3 3.5 20 d1 0.42 3 2.79 42.7 3 60 40.4 2 20 45.9 3 20 41.8 3 20 33.9 1.5 20 d2 o.49 3 2.42 42 0 60 43 0 20 42.7 0 20 40.4 0 20 36 0 20 d3 0.51 3 2.32 41.3 0 60 40 0 20 42 0 20 42 0 20 38 0 20 d4 0.05 3 7.74 43.6 4.5 60 37.6 0 20 45.9 5 20 47.3 5 20 31.2 0 20 ms 0.19 3 4.75 39 0.5 60 32.2 0 20 39.4 1 20 45.4 3 20 45 3 20 fs d.f f ± sd mean n0. ±sd mean ±sd mean ±sd mean ±sd mean no. <0.001 3 6.9** 5.5 9 60 4.1 9 20 5.9 12 20 4.8 6 20 4.4 6 20 ds 0.007 3 4.3** 9.5 17 60 8.9 14 20 8.2 21 20 10.3 17 20 6.3 12 20 dmfs 0.007 3 4.3** 3.2 9 60 2.8 8 20 2.6 11 20 3.6 9 20 2.8 8 20 dmft *significant p<0.05; **high .significant p<0.01. table 2: oral cleanliness among pregnant and non-pregnant women according to trimesters. parameters non-pregnant 1st trimester 2nd trimester 3rd trimester total pregnant statistical differences between trimester and non-pregnant no. medianmean rank no. medianmean rank no. medianmean rank no. medianmean rank no. medianmean rank chisquare d.f p value plaque index 20 0.142 22.4 20 0.321 35.7 20 0.6155 52.7 20 0.589 51.2 60 0.463 46.5 22.6 3 <0.001** calculus index 20 0.0089 31.2 20 0.01875 37.6 20 0.0285 49.4 20 0.0175 43.9 60 0.o191 43.6 6.92 3 0.07 *significant p<0.05; highly significant value<0.01 table 3: salivary physico chemical characteristic among nonpregnant and pregnant women according to trimesters. statistic al differences among four groups total pregnant women 3rd trimester 2nd trimester 1st trimester non-pregnant women parameters p -value d.f f ±sd mean no. ±sd mean no.±sd mean no.± sd mean no. ± sd mean no. 0.23 3 1.470 0.51 1.21 60 0.42 1.16 20 0.72 1.36 20 0.29 1.11 20 1.21 1.07 20 salivary flow rate <0.001** 3 17.811 0.4 7.4 60 0.4 7.4 20 0.3 7.1 20 0.4 7.5 20 0.3 7.9 20 salivary ph <0.001** 3 7.687 0.0038 0.0131 60 0.0038 0.0154 20 0.0043 0.0122 20 0.0018 0.0117 20 0.00330.010420 viscosity *significant p<0.05; highly significant value<0.01 j bagh college dentistry vol. 29(2), june 2017 dental caries severity pedodontics, orthodontics and preventive dentistry 118 table 4: relation of dental caries with oral cleanliness for pregnant women. parameter p li cal i r p r p d1 0.062 0.58 0.201 0.07 d2 0.298 0.007 0.195 0.08 d3 0.44 <0.001** 0.164 0.15 d4 0.225 0.045 0.204 0.07 ds 0.432 <0.001** 0.331 0.003** ms 0.373 <0.001** 0.4 <0.001** fs -0.11 0.33 -0.086 0.45 dmfs 0.401 <0.001** 0.363 <0.001** dmft 0.28 0.012* 0.25 0.025* *significant p<0.05; highly significant value<0.01 table 5: relation of dental caries with salivary physicochemical characteristic for pregnant women. dmft dmfs fs ms ds d4 d3 d2 d1 parameters p r p r p r p r p r p r p r p r p r 0.91 -0.013 0.35 0.106 0.36 0.103 0.32 0.113 0.64 -0.053 0.78 0.031 0.2 -0.146 0.58 0.064 0.7 -0.044 s.f.r **<0.001-0.364 <0.001**-0.43 0.55 0.067 *0.008 -0.293 <0.001 ** -0.424 0.042 * -0.228 0.08 -0.198 0.12 -0.173 0.09 -0.189 ph 0.23 -0.136 0.64 -0.054 0.08 -0.199 0.55 0.067 0.76 0.053 0.23 0.136 0.85 0.022 0.48 -0.081 0.41 -0.094 viscosity table 6: effect of pregnancy on oral variables (roc test). variables roc area p-value salivary ph 0.907 <0.001** plaque index 0.801 <0.001** salivary viscosity 0.757 <0.001** dmfs 0.673 0.021* ds 0.668 0.025* calculus index 0.655 0.039* ms 0.655 0.039* d2 0.610 0.14 dmft 0.605 0.16 d3 0.576 0.31 fs 0.575 0.32 d4 0.542 0.58 salivary flow rate 0.538 0.61 d1 0.504 0.96 *significant p-value<0.05;**highly .significant p-value<0.01. figure 1: roc curves for oral variables. figure 2: roc curves for selected oral variables (salivary ph and fs). j bagh college dentistry vol. 29(2), june 2017 dental caries severity pedodontics, orthodontics and preventive dentistry 119 discussion physiologic changes during pregnancy may result in noticeable changes in the oral cavity these changes may include dental caries, pregnancy gingivitis, periodontitis, and other oral diseases (3-5). the same results found in the current study pregnant women experienced an increase in dental caries severity represented by significant higher (dmfs, ds and ms values) ,all grades of caries lesion severity (d1-4) were higher among pregnant women than non-pregnant but with non-significant differences .this is probably due to increased consumption of carbohydrates, and reduced salivary production and/or increased acidity of saliva, increased acid in the mouth from vomiting. (30-32). in addition the number of certain salivary cariogenic microorganisms as streptococcus mutants and lactobacilli found to be increased (10, 33). the same result was also found by other studies (9-12). while the result reached was in opposite with papp et al., (14) who found a decrease in decay teeth surfaces during pregnancy. regarding trimesters, dental caries experience (dmft, dmfs, and ds) was higher in the second trimester. , as well the grades of caries severity (d1, d2, d4) were this probably due to hormonal changes that reached to peak level in the second trimester (34).that was reported to affect oral health (4)this this finding in accordance with previous iraqi study by al-zaidi, (13) that revealed the mean values of dental caries were higher in pregnant women especially in the first and second trimesters than the control group but the differences were statistically non-significant. regarding oral cleanliness, results of the current study revealed that both plaque and calculus accumulation were higher among pregnant women than non-pregnant with significant difference for both. this finding may further explain higher caries severity during pregnancy since). dental plaque is the main etiologic factor for dental caries (35). also dental calculus act as retentive factor for dental plaque (36). this is further supported by the positive correlations of plaque and calculus indices with dental caries parameters that were significant and highly significant with most of the dental caries parameters for pregnant women. also by using the roc test it has been found that plaque index is the second oral variable after salivary ph to be affected or changed during pregnancy with highly significant differences. this is probably because pregnant women might become anxious, restless and exhausted, in addition to nausea and vomiting during pregnancy that made the routine oral hygiene practices more difficult (36). poor oral hygiene was also reported by. tilakaratne et al (37). but contraindicated with other study by yas (2004) (11) who found low values of plaque in pregnant than non-pregnant while calculus index was similar, also results revealed that both plaque and calculus indices were higher in the second trimester with higher significant differences for plaque .that is further explained higher caries severity during the 2nd trimester. this is consistent with previous studies suliaman (10). while al-zaidi,(12) revealed higher plaque in the first trimester followed by 3rd trimester. saliva play an important role in maintaining oral health through its flow rate, buffer capacity and organic and in organic constituent (38, 39). in the current study results revealed that salivary flow rate was higher during pregnancy than non-pregnant women but with non-significant differences. this might be attributed to the sensitivity of the salivary glands by the nausea and vomiting that are usually linked with pregnancy (16-18). the same result was added by al-taie (17) but the result was in opposite with suliaman (10). while al-zaidi(12) reported no statistically significant difference. regarding salivary ph in the current study. salivary ph was lower (more acidic) among pregnant women than non-pregnant with highly significant difference. this may give another explanation for higher caries severity during pregnancy. since lower salivary ph means more acidic saliva that enhance or exaggerated the demineralization of dental enamel also most of the chemical reactions occurs in the oral cavity affected by hydrogen ion. (40). this is further supported by the inverse correlations of salivary ph with dental caries parameters .by using roc test results revealed that salivary ph was the first and the mostly affected oral variable during pregnancy with highly significant difference and roc area that was 0.907. saliva during pregnancy may become more acidic because serum concentration of estrogens is elevated iga increases, whereas sialic acid and buffer capacity decreased in saliva (41). lower salivary ph was also reported by another studies kivela et al, (18) and al-zaidi (12). results also revealed that salivary ph was lowest in the 2nd trimester with highly significant difference among four groups this give another explanation for higher caries severity during 2nd trimester. finally, salivary viscosity revealed higher mean value among pregnant than non-pregnant women with high significant difference especially in the 3rd trimester with high significant differences among the four groups this viscosity of saliva depended greatly on the method of stimulation (acid or mechanical)(42), and progesterone hormone will rise especially during the first two months of the j bagh college dentistry vol. 29(2), june 2017 dental caries severity pedodontics, orthodontics and preventive dentistry 120 third trimester after that it declined during the last month prior to child birth (43), also by using roc test, it was found that salivary viscosity was the third oral variable affected by pregnancy with highly significant differences (roc area= 0.757). an increasing salivary viscosity during pregnancy might contributed to increasing caries severity during pregnancy since increasing salivary viscosity means a reduction in water content and more thick saliva in turn affect the clearance action of saliva (44). however no studies could be found regarding the change in salivary viscosity during pregnancy to compare the result of the current study with them. references 1. abman, steven h.. fetal and neonatal physiology (4th ed.). philadelphia: elsevier/saunders.;46–47;2011. 2. fritz m.a, speroff, l. clinical gynecologic endocrinology and infertility, 8th ed.; 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[ivsl]. المستخلص النساء الفم تجویف في كما. الجسم نظام كل على تقریبا تؤثر التي الحیویة والكیمیائیة التشریحیة الفسیولوجیة، التغیرات من تجري العدید الحمل فترة خالل: خلفیة .األسنان تسوس شدة في زیادة وھناك بینھا، فیما التغییرات من العدید من یعانین الحوامل األسنان تسوس بین العالقة على وللعثور). واللزوجة الحموضة ودرجة اللعاب، تدفق معدل( مختارة اللعابیة والمتغیرات األسنان تسوس شدة لقیاس: الدراسة أھداف .المتغیرات ھذه مع امرأة 20( لالشھرالثالثھ من الحمل وفق متساویة مجموعات ثالث إلى تقسیمھا تم التي حامال امرأة 60نم الدراسة مجموعة تكونت: لطرقوا والمواد المواضیع غیر امرأة 20 إلى باإلضافة سنة) 2520(من المحددالعمر كان بغداد، مدینة في الطفل ورعایة األم صحة مراكز من عشوائیا اختیرت و). أشھر ثالثة كل في حامال األسنان تسوس شدة وسجلت. واللزوجة الحموضة درجة ثم. المحفزه اللعاب عینة تدفق معدل قیاس تم وقد. العمر في المطابقھ مع مقارنھ كمجموعة متزوجة البالك مؤشر نظام ,)1989( وآخرون manjieوصفھا التي المعاییر باستخدامd)mfs) 4-1بحشوات المعالجھ والسطوح والمفقود تسوس، مؤشر باستخدام لمعاییر (pdi) اللثة أمراض مؤشر من والتكامل التفاضل حساب ومؤشر. األسنان على البالك سمك لقیاس ) تستخدم(silness and löe1964 اعتمدھا ramffjord 1959)(. واالسطح المتاكلھ واالسطح المفقوده) والمفقوده والمعالجھ بحشواتاالسنان واالسطح المتاكلھ یمثلھا ( التي األسنان تسوس أن الحالیة الدراسة نتائج كشفت :النتائج (االسنان واالسطح المتاكلھ والمفقوده والمعالجھ بحشوات ل (p <0.05) االحتمالیة القیمة في معنوي اختالف مع الحوامل غیر النساء من الحوامل بین أعلى كانت من الدرجھ االولى اوالنخر التاكل ( من المستویات جمیع وشدة (p = 0.05) االحتمالیة القیمة حد من قریبة كانت كانت كما , واالسطح المتاكلھ واالسطح المفقوده) فتره من الثاني الثلث( في أعلى المفحوصھ األسنان جمیع تسوس وكان . (p> 0.05) ملحوظة غیر اختالفات وجود مع الحوامل غیر من الحوامل بین أعلى )للرابعھ واالسطح المتاكلھ وتنخر االسنان من الدرجھ االولى) (االسنان واالسطح المتاكلھ والمفقوده والمعالجھ بحشواتل (p <0.01) معنویة اختالفات وجود مع) الحمل .مجموعات ربعالأ بین غیر النساء من) الحمل فتره من الثالثةالوسطى األشھر في وخصوصا( الحوامل بین أعلى كان اللعاب تدفق معدل أن النتائج كشفت اللعابیة المتغیراتب یتعلق وفیما وجود مع الحوامل غیر النساء من الحوامل النساء لدى أقل كان اللعابیة الحموضة ودرجة (p> 0.05).قیمة من ملحوظة غیر اختالفات وجود مع ولكن الحوامل بین عالیة معنویة اختالفات وجود مع) الحمل فتره من الوسطى الثالثة األشھر( في األقل اللعابیة الحموضة درجة كانت .(p <0.01) بینھم عالیة معنویة اختالفات قیمھ أعلى وسجلت ،(p <0.01) معنویة اختالفات وجود مع الحوامل غیر النساء من الحوامل بین أعلى كانت اللعابیھ امااللزوجة (p <0.01) ,أالربع المجموعات قیم والقلح البالك مؤشر من كل سجلت الفم نظافة ناحیھ امامن.(p <0.01) مجموعات أالربع بین عالیة معنویة اختالفات وجود مع ) الحمل االخیرمن الثلث( في حموضھ درجھ سجلت قدو مجموعات أالربع بین التوالي على (p> 0.05) معنوي وغیر (p <0.01) معنوي ارتفاع مع الحوامل غیر من الحوامل بین أعلى للتاكل اوالنخرمن الدرجھ الرابعھ واالسطح ل( ) (p<0.05ظوفرق احصائي ملحو عالقات مع المفحوصھ األسنان تسوس مقاییس مع تقریبا عكسیة عالقة اللعاب اللزوجھ ومعدل تدفق اللعاب بینما ) و االسنان واالسطح المتاكلھ والمفقوده والمعالجھ بحشوات (السطوح المتاكلھمعبدالالت احصائیھ عالیھ العالقات و ) المفقوده .)(p>0.05 اظھر عالقات احصائیھ غیر ملحوظھ مع مقاییس التسوس اي اللعابیة والمتغیرات) والقلح للبالك مستوى أعلى( الفم نظافة على نفسھ الحمل تأثیر إلى یرجع ربما الحوامل النساء بین أعلى األسنان تسوس شدة كانت: االستنتاج الحوامل للنساء توجھ أن یجب الوقائیة والبرامج المكثف التعلیم لذلك،). واللزوجة اللعابیة الحموضة زیادة( .بیھاللعا اللزوجة الحمل، األسنان، تسوس: الرئیسیة الكلمات rasha f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry152 oral health status, salivary physical properties and salivary mutans streptococci among a group of mouth breathing patients in comparison to nose breathing rasha n. al-awadi, b.d.s. (1) mohammed al-casey, b.d.s., m.p.h., m.s.p.h. (2) abstract background: mouth breathing can lead to introduce cold, dry unprepared air that insults the tissue of oral cavity, nasopharynx and lung, leading in turn to pathological changes in oronasal cavity, nasopharyngeal and other respiratory tissue, mouth breathing associated with nasal obstruction may lead to many health problems, in particular oral health problems such as inflammation of gingiva, oral dryness, change in oral environment that may decrease ph, salivary flow rate and increase bacteria and dental caries.aims of the present study were to assess the oral health condition among mouth breather associated with nasal obstruction, including dental caries, oral cleanliness and gingival health condition as well as to evaluate the changes in salivary physical characteristics and salivary mutans streptococci counts, and their relation to oral variables in comparison to a control group. materials and methods: thirty patients with mouth breathing associated with nasal obstruction (15 females and 15 males) were selected as a study group with an age range (18-22) years old, all subjects were examined by ent specialist to confirm mouth breathing. a 30 gender and age matched healthy looking subjects without nasal obstruction were selected as control. the diagnosis and recording of dental caries was according to severity of dental caries lesion through the application of d1_4mfs(manji et al., 1989). plaque index of (silness and loe, 1964) was used for plaque assessment; gingival index of (loe and silness, 1963) was used for gingival health condition assessment. stimulated salivary samples were collected according to (tenovuo and lagerlof, 1996) and the following variables were recorded: microbiological analysis included the salivary counts of mutans streptococci, salivary flow rate, salivary ph (potential of hydrogen) and then measurement of salivary viscosity by using ostwald's viscometer. results: results of the present study showed that the mouth breathing group had statistically highly significant, higher plaque and gingival indices than nose breathing group (p<0.01) with a positive highly significant correlation between them in mouth breathing and nose breathing groups (r=0.56, r= 0.64, respectively).the salivary flow rate was lower among mouth breathing with highly significant difference than nose breathing (p<0.01), also salivary ph was lower among mouth breathing but with significant differencecompare to nose breathing (p<0.05); statistically a negative highly significant correlation was recorded among mouth breathing group between salivary flow rate with gingival index (r= -0.56). it has been found that salivary viscosity was not statistically significant difference between mouth breathing group and nose breathing group. the salivary viscosity was found to be inversely significantly correlated with salivary flow rate among mouth breathing group (r= -0.38). while it was positively not significantly correlated with plaque index, gingival index and counts of mutans streptococci among mouth breathing group. data analysis of the present study showed that salivary mutans streptococci counts among mouth breathing group were higher than that among nose breathing group, difference was statistically highly significant (p<0.01). conclusion: mouth breathing associated with nasal obstruction may have an effect on oral health status, leading to an increase in periodontal disease and changes in dental caries. key words: mouth breathing, nasal breathing, saliva (ph, flow rate, viscosity), salivary mutans streptococcus, oral diseases. (j bagh coll dentistry 2013; 25(special issue 1):152-159). introduction nasal breathing is the primary mode of air intake for the human, and it is essential for supply of properly cleansed, moistened and warmed air for lung. the mouth is only secondary emergency orifice for assuring an uninterrupted supply of air (1,2). mouth breathing is an unnatural act of necessity to get air into the lungs when the primary air way is blocked by nasal, nasaopharyngeal such as enlarged adenoids, enlarged tonsils, rhinitis, nasal septal deviation, sinusitis, turbinate hypertrophy and nasal polyp. (1)m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, baghdad university (2) professor, department of pedodontics and preventive dentistry, college of dentistry, baghdad university the individual which has nasal obstruction is suffering from dryness usually result from open mouth sleeping, the mouth breathing lead to increase lip separation and decrease upper lip coverage at rest were all associated with higher levels of plaque and gingival inflammation (3-5). the vast majority of health care professionals are unaware of the negative impact of upper airway obstruction (mouth breathing) on normal facial growth and physiologic health. children whose mouth breathing is untreated may develop long, narrow faces, narrow mouths, dental malocclusion, gummy smiles and other oral health problems. these children do not sleep well at night due to obstructed airways; this lack of sleep can adversely affect their growth and academic performance.it is important for the entire health j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry153 care community (including general and pediatric dentists) to screen and diagnose for mouth breathing in adults and in children. if mouth breathing is treated early, its negative effect on facial, dental development, oral health status and the medical and social problems associated with it can be reduced or averted (6,7,8) “the secretions of the salivary glands are of paramount importance for the maintenance of oral health” (9). the mutans streptococcal group is considered to be a major etiologic agent in the pathogenesis of dental caries (10-12). however, saliva helps to control invasion of the mouth by microorganisms, and lack of saliva results in increased numbers of bacteria in the mouth (13). salivary flow provides mechanical cleansing of the residues present in the mouth such as non adherent bacteria, cellular and food debris. thus, lack of mechanical salivary flushing results in accumulation of food debris and dental plaque, thereby promoting an aciduric and acidogenic oral microflora that promotes the development of caries (10,12,14). saliva possesses specific rheological properties (viscosity and elasticity) as a result of its chemical, physical and biological characteristics, these properties being essential for maintaining balanced conditions within the oral cavity. there is controversy in relation between salivary viscosity and oral disease such as dental caries and periodontitis (15,16) the complaint of oral dryness is very common in mouth breathers, and normally this symptom is associated with diminution of salivary flow rates. however, in the specific case of the mouth breathers, the cause of xerostomia may be simply oral desiccation (17,18). when subject breathe through the mouth, there is loss of saliva and dryness of the mouth and this can increase the risk of tooth decay and inflammation of the gingiva. also mouth breathing can lead to alterations in the jaw and facial growth (7,19). materials and methods the study group in the present study, the study group composed of thirty patients (15 females and 15 males) with an age range (1822) years according to the last birthday (20). they were selected from patients attending theconsultation clinical of ear, nose, throat and the specialized surgeries hospital in baghdad city for their treatment, all selected patients were mouth breathing for at least 2 years. the control group the control group composed of thirty subjects (15 females and 15 males) with an age range (1822) years, were selected from dental student in dentistry collage, university of baghdad.those subjects were examined by simple method used to select nose breathers was demonstrated (21) a small cotton wisp was held in front of each nostril of all the individuals. no movement of cotton wisp when held in front of the nose indicated mouth breathing. individual showing movement of cotton wisp when held in front of the nose indicated normal nasal breathing; the latter is included in control group. clinical examination: ent examination each individual was examined by an ent specialist to include or exclude the presence of any nasal obstruction and this was assisted by radiography and nasal endoscope if there is need to diagnose if there is polyp or any septal deviation. oral health examination oral examination was carried out under standardized conditions according to the basic methods of oral health surveys of world health organization (22) that the subject was seated on a straight chair with tall back on which the head was rested. the diagnosis and recording of dental caries was according to severity of dental caries lesion through the application of d14 mfs (23). plaque index of silness and loe (24) was used for plaque assessment; gingival index of loe and silness(25) was used for gingival health condition assessment. collection of salivary samples and procedure: the collection of stimulated salivary samples was performed under standard condition following instruction cited by tenovuo and lagerlof (26): • the patient should not eat or drink except water one hour before collection. • a pre sampling period one minute is recorded. • the patient should not smoke or undergo heavy physical stress before collection. • a fixed collection time (in this study was from 8-11 am). • the patient should sit in a relaxed position. • samples containing blood should be discarded if chemical analysis of saliva is planned. • acute illness or chronic diseases as well as medication should be considered. each individual was asked to chew apiece of arabic gum (0.5-0.7) gm for one minute, then removed all saliva by expectoration, after that chewing was continued for ten minutes with the same piece of gum and saliva collected in a sterile screw capped bottle. salivary volume was estimated and rate of secretion was expressed as milliliter per minute (ml/min). after collection and disappearance of salivary foam, 0.1 ml of saliva was transferred to 9.9 ml of sterile normal j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry154 saline (ph 7.0).tenfold serial dilutions were prepared usingnormal saline. two dilutions were selected for each microbial type and inoculated on the following culture media: msb agar (the selective media formutans streptococci) 0.1ml was withdrawn fromdilutions (10-2, 10-4) and then spread in duplicate by using sterile microbiological spreader on the plates of msb agar then the plates wereincubated anaerobically using a gas pack for 48 hr. at 37°c then incubated aerobically for 24 hr. at room temperature(27). following incubation, colonies were identified andcounted by the use of the colony counter. the number of colonies was recorded taking in consideration the dilutions factor, and expressed as colony forming unit per ml saliva i.e. cfu/ml saliva (12).also within less than 15 minutes, the ph of the saliva was measured using a digital ph meter. then measure the viscosity of saliva by ostwald viscometer(28,29)( figure1). the ostwald method is a simple and available method for the measurement of viscosity, in which viscosity of liquid is measured by comparing the viscosity of an unknown liquid with that of liquid whose viscosity is known. in this method viscosity of liquid is measured by comparing the flow times of two liquids of equal volumes using same viscometer. consider two liquids are passing through a capillary of same viscometer. then the coefficient of viscosity of liquid (η2) is given by equation: η1 /η2 = ρ1 t1 / ρ2 t2(unit of viscosity is poise) η1 = coefficient of viscosity water equal 0.008904 poise at 25 c0(30). η2 = viscosity of saliva. ρ1 =density of distilled water gm/cm 3 . t1 = time to pass the distilled water in second. ρ2 = density of saliva sample. t2 = time to pass the saliva in second. figure 1 results table 1 illustrates the mean values in addition to standard deviations of plaque and gingival indices among the mouth breathing and nose breathing groups. clinical oral examination revealed highest mean values of plaque index among the mouth breathing group compared to nose breathing group with statistically high significance difference (t= 7.72, p<0.01, df= 58). values grades of ds (d1, d2, d3, d4) (mean and standard deviation) among mouth breathing and nose breathing groups are presented in table 2. for both mouth breathing and nose breathing groups including males and females. it was found that presence of higherd1mean values among nose breathing group compared with mouth breathing group with no statistically significant difference between them (t= 0.58, p>0.05, df=58) while for d2, d3, d4mean values, it was found higher in mouth breathing group in comparing to nose breathing group with also no significant difference between them (p>0.05, df=58). clinical oral examination revealed higher mean values of ds among the mouth breathing group compared to nose breathing group with statistically no significant difference (t=1.80, p>0.05, df=58). table 3 illustrates the mean values in addition to standard deviations of salivary flow rate and salivary ph among the mouth breathing and nose breathing groups. the mean values of salivary flow rate was found lowest in mouth breathing group with statistically highly significant difference in compared to nose breathing group (t= 4.06, p<0.01, df=58). salivary ph mean values was found lower in mouth breathing group with significant difference in compared to mouth breathing group (t= 2.40, p<0.05, df=58). table 4 illustrates the mean values in addition to standard deviations of salivary viscosity among the mouth breathing and nose breathing groups. result showed that no statistically significant difference in salivary viscosity between both groups (t=0.57, p>0.05, df= 58). table 5 shows the mean and standard deviation counts of salivary mutans streptococci among the mouth breathing and nose breathing groups. mean counts of salivary mutans streptococci was found highest in mouth breathing group with statistically highly significant difference in compared to nose breathing group (t= 7.099, p<0.01, df=58). table 6 illustrates the correlation coefficient of plaque index in relation to gingival index among mouth breathing and nose breathing groups. results revealed that there is a positive highly significant relation found between plaque index with gingival inflammation in the mouth breathing group also there is a positive highly significant correlation was found between them in the nose breathing group. table 7 illustrates the correlation coefficient of gingival index in relation to salivary flow rate among mouth breathing and nose breathing groups. among the mouth breathing group, statistical results revealed that there is a negative highly significant relation found between gingival inflammation with salivary flow rate. j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry155 table 8 demonstrates the correlation coefficient of salivary viscosity in relation to salivary flow rate among mouth breathing and nose breathing groups. among the mouth breathing group, statistical results revealed that there is a negative significant relation found between salivary viscosity with salivary flow rate. regarding data analysis in each gender, revealed that no significant difference in salivary viscosity between two gender among both groups (p >0.05, df= 28). discussion dental plaque was reported to be the main etiological factor for periodontal diseases (31,32). in order to provide precise evidence of the relationship between the amount of plaque and gingival inflammation the gingival index of löe and silness(25) was used to assess the gingival condition together with plaque index of silness and löe(24). these two are widely used in both epidemiological and controlled studies due to their ease, validity and feasibility, as well as they allow the assessment of the state by severity (33).in present study, the higher mean values of gingival index among mouth breathing group may be attributed to the higher mean values of plaque index (1.15 ± 0.36) that recorded among mouth breathing group with high significance difference compared to nose breathing group (0.52 ± 0.26) this finding is in agreement with other studies that found increase gingivitis among mouth breathing (5,34-37) .the present study revealed that higher pli and gi with mouth breathing than control this may be attributed to lower salivary flow rate among mouth breathing group with statistically highly significant, the result can be explained by that the salivary flow rate may play an important role in relation to plaque accumulation since decrease of salivary flow rate lead to decrease of washing action of saliva and oral dryness as well as protective constituents decreased with decreased flow rate (38) so the plaque accumulation increased and this confirmed by the result of the present study which showed negative not significant correlation of salivary flow rate with plaque index and highly significant in negative direction with gingival index among mouth breathinggroup. in the group of mouth breathers may retain a greater amount of bacteria in their oral cavities due to evaporation of water from the saliva constant mouth breathers that can reach 0.24 ml/min (39) .this can make the clearance and bacterial aggregation product by mucin mg2 more difficult (40). in the present study revealed that mean values caries experience represented ds components among mouth breathing group was higher than control group with no significant difference. further data analysis concerning grades of ds showed that the caries lesion severity represented by d2, d3 and d4 were higher among mouth breathing group than control group with no significant difference. this may be attributed to many findings that illustrated by the data of the present study, these include: higher mutans streptococci among mouth breathing than nose breathing with highly significant differences. streptococcus mutans is considered a major cariogenic bacterium(10,12). ; lower ph mean value among mouth breathing than nose breathing with significant differences. saliva with a low ph provides a suitable environment for acidogenic bacteria, cariogenic bacteria tolerate very low ph by producing lactic acid as a byproduct of carbohydrate metabolism(41), during low ph calcium and phosphorus are liberated from the enamel to the biofilm. ; lower flow rate among mouth breathing than nose breathing with highly significant difference between them. saliva flow rate has an important role to protective teeth against dental caries. there are previous studies reported that increase levels of dental caries due to related to decrease flow rate (16). the decrease ph level among mouth breathing group may be attributed to the results of the present study showed that: higher mean of mutans streptococcus counts with highly significant differences among mouth breathing group than nose breathing, a negative correlation between ph and mutans streptococcus counts among mouth breathing group, the results can be explained by that the mutans streptococcus may play an important role in acid production this lead to decrease in ph. and decrease ph among mouth breathing due to the decrease salivary flow rate among mouth breathing, this can be explained by salivary ph varies in accordance with the sfr, from 5.3 low sfr to 7.8 (peak sfr), at low sfr lead to lower bicarbonate, thus decrease ph(42,43,44).the lower in the salivary ph within mouth breathing may be attributed to other factors conducted by other studies: weiler et al. (19) found higher level of free sliaic acid among mouth breathing group is indicative of an increase number of bacteria in saliva this will lead to decrease of ph as in the present study. flutter, (45) found that relation between reduce co2 among mouth breathing group with ph. mouth breathing lead to reduce co2 content in alveoli of the lungs (hypocapnia). co2 is the most important factor in controlling ph by buffering with bicarbonate or carbonic acid. j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry156 the present study showed a lowest mean salivary flow rate among mouth breathing compared to nose breathing group with highly significant difference this finding is in agreement with lida et al, while it is disagreement with others (47,48,19). the decrease flow rate among mouth breathing may be due to the complaint of oral dryness is very common in mouth breathers, and normally this symptom is associated with diminution of salivary flow rates, also lower salivary clearance in mouth breathers due to great evaporation of saliva(17,18). the present study results showed that statistically no significant difference regarding salivary viscosity between mouth breathing and nose breathing. this may be attributed to viscosity of saliva depended greatly on the method of stimulation (acid or mechanical) (49), so van der reijden et al. (50,51)have observed different viscoelastic properties for the saliva excreted from different glands within the oral cavity, since submandibular/sublingual saliva contains much higher concentrations of mucins and glycoproteins than does parotid saliva, also saliva containing mucins of different conformation, molecular weight and concentration.concerning gender differences in the current study, results revealed no significant differences between gender among both groups this is in accordance with briedis et al. and rantonen,(52,53) who found that no statistically significant differences between genders in salivary viscosities, and gender did not affect the within-subject variation of salivary viscosities. references 1. wagaiyu e, ashley f. mouth breathing, lip seal and upper lip coverage and their relationship with gingival inflammation in 11–14 year-old schoolchildren. j clinical periodontol 1991; 9(18)698-702. 2. drake-lee a. physiology of the nose and paranasalsinus. in: glesson m, ed, scott-brown's otorhinolaryngology, head and neck surgery.7th ed. edward arnold (publishers) ltd; 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43: 201-6. 23. manji f, fejerskove o, baelum v. pattern of dental caries in an adult rural population. caries res 1989; 23:55-62. 24. silness j, loe h. periodontal disease in pregnancy ii. acta odontol scand 1964; 22: 747-59. 25. loe h, silness j. periodontal disease in pregnancy i. acta odontol scand 1963; 21:533-51. 26. tenovuo j, lagerlof f. saliva. in: thylstrup a, fejerskov o (eds). textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1996.pp. 17-43. j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry157 27. holbrook w, beighton d. streptococcus mutans levels in saliva and distribution of serotypes among 9 years old icelandic children. scan dent res 1986; 95:37-42. 28. shridhar r. century of noble prizes: 1909 chemistry laureate wilhelm ostwald (1853-1932). chem educ 2003; 79: 146. 29. ostwald w, van houten. nobel centennial essays: 1909. j chem educ 2002; 79: 146. 30. lide d. viscosity of liquids. in: crc hand book of chemistry and physics. 89th ed. chemical rubber company press, inc.; 2009. 31. lindhe j, karring t, lang p. clinical periodontology and implant dentistry. 4th ed. oxford: oxford university press; 2003. 32. murray j, nunn j, sted j. the prevention of oral disease. 4th ed. oxford university press, italy, 2003. 33. ciancio sg. status of indices of gingivitis. j clin periodontol 1986; 13: 375-6. 34. alexander ag. habitual mouth-breathing and its effect on gingival health. parodontologie 1970; 24: 4952. 35. jacobson l. mouth-breathing and gingivitis. j periodontol res 1973; 8: 269-277. 36. eslami a, sadeghi em. mouth breather's gingivitis: a clinicopathologic review. compendium 1987; 8: 20-4. 37. solomon n, patricia a. uncommon causes of gingivitis. j dent oral hyg 2011; 3(5): 65-8. 38. lenander-lumikari m, loimaranta v. saliva and dental caries. adv dent res j 2000; 14: 40-7. 39. guggenheim b.cariology today, s. karger,basel, 1984; 70. 40. slomiany b, murty vln, mandel, zalesna, slomiany a. physico-chemical characteristics of mucus glycoproteins and lipids of the human oral mucosal coat in relation to caries susceptibility. arch oral biol 1989; 229-37. 41. mount gj, ngo h. minimally intervention: advanced lesions. quintessence int 2000; 31(9): 621-9. 42. tenovuo j, lagerlöf f. saliva. in: thylstrup a, fejerskov o. textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1994. 43. axelsson p. diagnosis and risk prediction of dental caries. v. 2. illinois: quintessence books, 2000. 44. humphrey sp, williamson rt. a review of saliva: normal composition, flow, and function. j prosthet dent 2001; 85:162-9. 45. flutter j. the negative effect of mouth breathing on the body and development of the child. int j orthod milwaukee. 2006; 17(2): 31-7. 46. lida m, nakagaki h, kato k, chu s, kojima s, lgo j, miyajima k, goto, s. fluoride release from a lightcured bonding material in open bite orthodontic patients, asdc j dent child 1998; 65:330-4. 47. narh t. prevalence of subjective feelings of dry mouth in elderly. j dent res 1994; 73: 20-5. 48. koga c, unterkircher c, fantinato v, watanabe h, jorge a. influence of oral breathing syndrome in the presence of streptococcus mutans and immunoglobulin anti-streptococcus mutans in saliva. j dentistry, unesp 1996; 25:207-16. 49. stokes jr, davies ga. viscoelasticity of human whole saliva collected after acid and mechanical stimulation. biorheology 2007; 44:141-60. 50. van der reijden, wa, veerman eci, amerongen avn. shear rate-dependent viscoelastic behavior of human glandular saliva. bio-rheology 1993a; 30: 141-52. 51. van der reijden, wa, veerman eci, amerongen avn. erratum: shear rate-dependent viscoelastic behavior of human glandular saliva. bio-rheology 1993b; 30: 301. 52. briedis d, moutrie mf, balmer rt. a study of the shear viscosity of human whole saliva. rheol acta 1980; 19: 365-74 53. rantonen p. salivary flow and composition in healthy and diseased adults. a thesis. department of oral and maxillofacial diseases, institute of dentistry, university of helsinki, finland, 2003. table 1: plaque index and gingival index (mean and standard deviation) among mouth breathing and nose breathing groups. variable gender mouth breathing nose breathing statistic test mean ± sd mean ± sd t-test p-value pli m 1.26 ± 0.45 0.58 ± 0.24 5.27** 0.000 f 1.03 ± 0.22 0.47 ± 0.27 6.31** 0.000 t 1.15 ± 0.36 0.52 ± 0.26 7.72** 0.000 gi m 1.06 ± 0.27 0.32 ± 0.098 10.19** 0.000 f 0.98 ± 0.25 0.40 ± 0.33 5.50** 0.000 t 1.02 ± 0.26 0.36 ± 0.24 10.36** 0.000 ** highly significant p < 0.01 j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry158 table 2: grades of ds (d1, d2, d3, d4) (mean and standard deviation) among mouth breathing and nose breathing groups. ds grades gender mouth breathing nose breathing statistic test mean ± sd mean ± sd t-test p-value d1 m 1.40 ± 1.595 1.73 ± 1.34 0.62 0.54 f 1.60 ± 1.24 1.67 ± 1.23 0.15 0.88 t 1.50 ± 1.41 1.70 ± 1.26 0.58 o.57 d2 m 3.87 ± 2.997 2.60 ± 2.098 1.34 0.19 f 4.67 ± 3.44 3.87 ± 2.59 0.72 0.48 t 4.27 ± 3.19 3.23 ± 2.40 1.42 0.16 d3 m 0.47 ± 0.83 0.20 ± 0.56 1.03 0.31 f 0.73 ± 1.44 0.20 ± 0.41 1.38 0.18 t 0.60 ± 1.16 0.20 ± 0.48 1.74 0.08 d4 m 0.33 ± 1.29 0.00 ± 0.00 1.00 0.33 f 0.00 ± 0.00 0.00 ± 0.00 ------------ t 0.17 ± 0.91 0.00 ± 0.00 1.00 0.32 ds m 6.07 ± 3.41 4.53 ± 2.59 1.39 0.18 f 7.00 ± 3.27 5.73 ± 2.69 1.16 0.26 t 6.53 ± 3.32 5.13 ± 2.66 1.80 0.07 table 3: the salivary flow rate (ml\min) and salivary ph (mean and standard deviation) among mouth breathing and nose breathing groups. variables gender mouth breathing nose breathing statistic test mean ± sd mean ± sd t-test p-value salivary flow rate m 0.77 ± 0.42 1.47 ± 1.22 2.12* 0.04 f 0.65 ± 0.41 1.43 ± 0.46 4.88** 0.000 t 0.71 ± 0.41 1.45 ± 0.91 4.06** 0.000 salivary ph m 6.94 ± 0.57 7.34 ± 0.34 2.31* 0.03 f 6.42 ± 1.65 7.17 ± 0.41 1.699 0.10 t 6.68 ± 1.24 7.25 ± 0.38 2.40* 0.02 *significant p<0.05 ** highly significant p < 0.01 table 4: the salivary viscosity (poise) (mean and standard deviation 10-3) among mouth breathing and nose breathing groups. variable gender mouth breathing nose breathing statistic test mean ± sd mean ± sd t-test p-value #salivary viscosity m 13.07 ± 1.75 12.87 ± 1.72 0.32 0.76 f 13.93 ± 2.46 14.93 ± 3.97 0.83 0.41 t 13.50 ± 2.15 13.90 ± 3.19 0.57 0.57 #the values expressed by 10-3 table 5: count of salivary mutans streptococci (mean and standard deviation) among mouth breathing and nose breathing groups. variable gender mouth breathing nose breathing statistic test mean ± sd mean ± sd t-test p-value #mutans strep. m 20.81 ± 13.03 4.98 ± 2.45 4.62** 0.000 f 18.53 ± 7.74 5.05 ± 5.11 5.63** 0.000 t 19.67 ± 10.60 5.02 ± 3.94 7.099** 0.000 #the values expressed by 107 cfu/ml of saliva. ** highly significant p < 0.01 table 6: correlation coefficient between plaque index with gingival index among mouth breathing and nose breathing groups. groups variable gi r p mouth breathing pli 0.56** 0.001 nose breathing pli 0.64** 0.000 ** highly significant p < 0.01 j bagh college dentistry vol. 25(special issue 1), june 2013 oral health status pedodontics, orthodontics and preventive dentistry159 table 7: correlation coefficient between gingival index with salivary flow rate among mouth breathing and nose breathing groups. groups variable sfr r p mouth breathing gi -0.56** 0.001 nose breathing gi -0.06 0.75 ** highly significant p < 0.01 table 8: correlation coefficient between salivary viscosity with salivary flow rate among mouth breathing and nose breathing groups. groups variable sfr r p mouth breathing viscosity -0.38* 0.04 nose breathing viscosity -0.20 0.29 * significant p<0.05 rola.doc j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 32 estimation of the linear dimensional changes of autoclave cured acrylic resin with multiple palatal depths and investment materials rola w.a, b.d.s., m.sc. (1) ali n.a, b.d.s., m.sc. (1) abstract background: dimensional changes of acrylic denture bases after polymerization results in need for further adjustments or even ends with technical failure of the finished dentures. the purpose of this study was to estimate the linear dimensional changes for different palatal depths when using multiple investment materials and polymerization techniques. materials and methods: ninety upper complete denture bases were constructed for this study. they were divided into two main groups according to the polymerization methods: conventional water bath and experimental autoclave (short and long cycles). each main group was further subdivided into three subgroups according to the palatal depth (shallow, medium and deep). furthermore, for each palatal depth; complete denture bases were invested either with dental stone or laboratory silicone. for each upper complete denture, measurements of linear dimensional changes were done by fixation of metallic screws on the tissue surface of the denture base. the distances were measured by using travelling microscope with an accuracy of 0.001 %. the data were statistically analyzed using three way analysis of variance (anova) for three variables, which were (palatal depth, investments and polymerization techniques), lsd test and student t test for comparisons between groups. results: there were significant improvements in the dimensional accuracy of denture bases cured with autoclave compared with water bath. also, silicone investments were a successful alternative to stone, study data shows that short autoclave processing with silicone reduces the magnitude of the linear dimensional changes. on the other hand, long autoclave processing and stone investments were better than silicone in reducing dimensional changes. conclusion: the findings of this study indicates that the use of autoclave processing in acrylic curing is a promising alternative to the conventional water bath and leads to better dimensional stability for the finished dentures in all oral configurations and palatal depths. also, silicone is more preferable than stone, although it's not as strong investing materials when compared with stone. key words: linear dimensional changes, laboratory silicone, autoclave polymerization, travelling microscope. (j bagh coll dentistry 2015; 27(2):32-42). introduction the inaccuracy of maxillary complete denture represents a major clinical and technical issue caused by: type of investment materials, powder/liquid ratio of acrylic, packing and polymerization technique and finally temperature used during processing of the resin. so, changes in resin polymers were not uniformly distributed and many factors may act and affect each other at the same time. (1) during acrylic resin polymerization, the accumulative effects of the post polymerization dimensional changes combined with a variety of shrinkages occurs during both flask cooling and opening leads to distortions by stress relaxations, all these factors leads to linear dimensional changes. (2) one of the major factors that locally plays vital role in the success of maxillary complete denture is palatal depth and shape. (3) denture stability and retention depends to a greater extent on the depth of the palate. (4) water bath curing, regarded as the most favorable processing technique, its multiple benefits includes; easy and simple procedure and low price equipments, but still had main drawback of being time consuming method. (5) (1)lecturer. department of prosthodontics. college of dentistry, university of baghdad the highly favorable technique for acrylic resin processing is the fast one, and the researchers reported that this technique is acceptable for processing of denture bases at different volumes, configurations and depths. (6) autoclave polymerization was evaluated as processing technique for acrylic resin and the results showed acceptable improvements in the transverse strength of the tested samples when compared with samples processed with conventional polymerization even when both short and long curing cycles examined. (7) as an alternative to the strong dental stone which has been used as a conventional investment material, laboratory silicone represents a good choice with a higher accuracy. (8) the advantages of the laboratory silicone includes; flasking being further simpler, faster and without processing mess and decreasing the opportunity of denture distortions after flask opening. on the other hand, the knowledge about the effect of this investment material on the linear dimensional changes is still limited. (9) the establishment of linear dimensional changes was correctly done with the aid of a travelling microscope, with a higher accuracy to be able to record minimum dimensional changes in the acrylic resin. these changes were the j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 33 reasons for inaccuracies and leads to errors in the complete dentures. (4) the aim of this study was to estimate the influence of different palatal depths (shallow, medium and deep) on linear dimensional changes of denture bases invested with two types of investment (stone and laboratory silicone) and cured by two curing methods (conventional water bath and autoclave polymerization; short and long cycles). materials and methods a universal metallic edentulous cast (standardized metal brass, new york, usa) represents maxillary arch with a uniform residual alveolar ridge free from any discrepancies used to construct master silicon mold (columbia dent form corp.). as shown in figure 1. figure 1: silicone molds in the initial stages of making the casts. the master silicon molds were modified in order to make three molds simulating multiple palatal depths (shallow, medium and deep) so: the mold without modification was for shallow palate cast, while medium palate mold was made by placing two layers of base plate wax (shanghai new century dental material, china) on the palatal part of the mold to increase the depth of the palate to (13mm). on the other hand, deep palate was made by placing four layers of wax so increasing depth to 18mm. then the modified molds were poured with type iv dental stone (elite model, zhermack technical, italy) using p/w ratio of 100gm to 30ml and with the aid of vibrator (quayle dental, england). the casts were allowed to sets for 45min and then taken from the molds to form three palatal depth casts measured with digital vernier (shanghai shenhanme asuringtools co., ltd, china) by attaching the master cast to a dental surveyor (milling machine, af30, switzerland) in order to creates a zero tilting. during depth measurement, two standardized points were selected; first point represents the center of the incisive papilla and the second point at the center of fovea palatina. straight lines joined them together was drown, the middle of that line (at 39mm from the anterior edge of the cast) was bisected by a second line horizontally in the center, so the intersection point of these two lines represent center of the palate and from this point palatal depth was measured by horizontal placement of a plastic ruler (china plastic industry) on the alveolar ridge and the measuring point of the vernier touch the selected point to estimate the depth and standardize measurements for all casts. (10) the casts were duplicated to form 90 stone casts by using a plastic duplication flask (clear cast flask, vertex, netherlands), the cast was placed at the bottom (base) of the flask and fixed with hot wax, then the upper part of the flask was placed on the base. mean while, agar duplication material (castagel, vertex-dental, netherlands) was liquefied at (92ºc) and tempered at (48ºc) in a water bath (ewl 55 01, west germany) and poured until totally filled the flask and left to cool for 60 min. (11) the master cast was removed and mold space was filled with type iv dental stone. this operation was repeated until the planned number of the casts for the study was reached. a 2mm thickness of a clear thermoplastic acrylic cakes for record base (biocryl c, scheudental, iserlohn, germany) was used for all stone casts by similar construction procedure using universal biostar machine (schu-dental, germany) following manufacturer instructions. each record base thickness was calibrated and standardized with digital vernier. also, for each palatal depth, a red colored template was constructed from biostar materials to standardize the locations of the perforations of all record bases of the study. (12) the template record base perforated (drilled) with round bur attached to laboratory engine (w&h torque, germany) attached to surveyor in order to form 7 uniform perforations in a previously selected region marked on the cast with black ink and with fixed distances between them. the regions were: p: center of incisive papilla; rc&lc: right and left canine; rt&lt: right and left tuberosity and m&v: anterior and posterior midpoint between (rc&lc and rt&lt) and the distances between these regions were measured by using travelling microscope (leitz /wetzlar, germany) to make a preprocessing twelve equal measurements, then the clear thermoplastic record bases were placed above the red template in order to correctly copy positions of perforations to all the record bases. then a 3mm length and 2mm diameter screw made from copper (dentsply-maillefer, swiss). j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 34 were placed and fixed inside the perforations and distances were in following arrangements; ridge arch (rt-rc,rc-p,rt-v,lt-lc,lc-p,lt-v) and palatal arch (p-m,m-v,rt-m,rc-m,lt-m and lc-m).(13) as shown in figure (2). figure 2: selected points for measurements of linear dimensional changes. the measurements between the reference points were evaluated and recorded in the record base before acrylic resin polymerization in order to make a comparison with the post polymerization measurements with the aid of a travelling microscope with an accuracy of 0.001mm as illustrated in figure 3. figure 3: travelling microscope used to determine dimensional changes. the record bases were organized according to the polymerization techniques, so casts were divided in to two major groups: first group was polymerized with conventional water bath and contain 30 samples and second group was polymerized with experimental autoclave including two cycles (short and long curing). each one contains 30 samples. each major group were divided into two groups each one contains 15 samples according to the type of investment weather stone or silicone and for each one; there were three subgroups represent various palatal depths (shallow, medium and deep) and each subgroup contains 5 samples. in flasking procedure, record bases with their casts were placed in the lower portion of a universal brass dental flask (broden, sweden) and type ii dental plaster (al-ahlya, iraq) was poured and filled the lower part. after a 45 min of setting period, sodium alginate separating medium (kamadent, swindon, england) was applied and after setting of 5 min, the upper portion of the flask was placed and a second mix of type iv stone fill the flask and upper cover was placed and the flask was left for 1 hour for final setting. (14) for samples invested with laboratory silicone, the same procedure was followed but instead of stone, a 200ml of silicon base and catalyst (castasil 21, vertex-dental, netherlands) were mixed homogenously in glass plate following manufacturer recommendations, when even mixture reached, same previous procedure was followed but a 20 minute for silicon setting was allowed. (15) then after the flask was opened, two layers of sodium alginate separating medium was applied on the flask two parts (14) as shown in figure 4. figure 4: half of the flask after opening and separation medium application. acrylic resin was (regular, tm, vertexdental, netherlands) manipulated and used with dry and clean mixing jar for mixing a ratio of 1:3 by stiff and clean spatula for about 30 seconds. the mixing jar with its content was covered with glass slap and allowed to be doughy in about 15 minutes, resin packed in the flask in organized groups with the aid of polyethylene sheet (amalgamated dental trade distributors ltd, london, england) served as a separation tool in primary flask closure under a pressure of 20 bars. (13) after the primary closure, polyethylene sheets discarded and any acrylic flashes at the periphery of the mold space were cut away with a sharp knife. then, groups polymerized with water bath were processed as follows: flasks were pressed in a hydraulic press (bremer goldschlagerei herbst west germany) for duration of 5 minutes and pressure of 20 bars and clamped in usual manner by using universal clamp (ash co., england). then, the flasks with their clamps were placed in a water bath machine (digital water bath, lab tech) and temperature was set for 90 minutes at 73cº then half an hour of boiling at 100ºc (14) as shown in figure 5. m rt lt v p lc rc j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 35 figure 5: electronic water bath machine with its control panel. on the other hand, experimental specimens were processed using an electronic sterilization autoclave (euronda, type b inspection) according to two selected programs represents long and short curing cycles. so flasks with their clamps were placed inside sterilizing chamber then the door was closed and secured, the two selected programs were operated in order to polymerize the acrylic resins as follows: 1. short curing cycle: 121°c and 210 kpa for 15 minutes. 2. long curing cycle: 121°c and 210 kpa for 30 minutes. (16) the chosen cycles were monitored by control panel of the machine in order to control operation stages including: evacuation of air, entrance of steam and starting sterilization with raising temperature and keeping it and finally lowering it for cooling. water steam was evacuated and curing cycle was finished. the device was shown in figure 6. figure 6: electronic autoclave machine with control panel. at the end of the processing procedure, the flasks were allowed to cool slowly at 23ºc of room temperature. the finished dentures were carefully removed from their flasks and any excess acrylic was trimmed away with tungsten burs under continuous water cooling. polishing was accomplished using pumice in a lathe machine (bego, germany), and specimen's storage were adjusted according to ada specification no.12 for effect of curing methods and investment materials, so for the linear dimensional changes dentures were de-casted before the measurements had been done. (13) differences in measurements before and after processing were estimated using travelling microscope and in the same circumstances applied before processing and by the same person to reduce the chances of error to minimum. the differences were represented as + when expansions and – when shrinkages and = when no changes were detected and subjected to statistical analysis using three way variance (anova) to determine variation between (palatal depth, type of investment and polymerization procedure with interferences between them) and least significant test (lsd) for comparison between palatal depth groups for each type of investment material, after that t-test for comparison between subgroups were used with level of significance of (0.05). results the means and standard deviations for linear dimensional changes were calculated in (mm) and presented in table 1. the three way anova table (f test) for the estimation of the relationship between palatal depths (shallow, medium and deep) of tested groups and its influence on linear dimensional changes indicates a high significant differences (p-value<0.01) with the use of both types of investment materials (stone and silicone) and with multiple curing methods (water bath and autoclave; short and long). these results were presented in table 2. also the least significant test lsd for the comparison between each palatal depth showed the followings: in water bath curing: in silicone investment there were significant reduction in the dimensional change magnitude in the medium and deep palate when compared with the shallow one in degree more than when stone investment were used, especially in the comparison between medium and deep palate. in short autoclave cycle: same finding of water bath curing methods was again found in short autoclave cycle when silicone investment was used except when the comparison was made between medium and deep palate when stone investment was used. in long autoclave cycle: stone were better than silicone in the reduction of the magnitude of the linear dimensional changes except when the comparison was made between medium and deep palate when silicone investment was used. and this was illustrated in table 3 and 4. effect of curing methods t-test for comparison between control group (water bath and stone investment) with j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 36 experimental group (short autoclave curing with both stone and silicone investment) revealed a high significant reduction (p-value<0.01) in the linear dimensional changes. especially, during the use of silicone investment there were reduction in the magnitude of dimensional changes although it was non-significant when compared with stone and this were clear in table 5. while for long curing cycle when compared with control group, results revealed that best reduction in the dimensional changes were obvious when stone investment was used and these were illustrated in table 6. on the other hand, t test for the comparison between experimental groups (short and long autoclave) cycles when stone investment material was used, magnitude of linear dimensional changes decrease in the long curing cycle especially in the medium and deep palate and these were illustrated in table 7. effect of investment materials t-test for comparison between investment materials (stone and silicone) for all curing methods and all palatal depths indicated that silicone investment have better reduction in magnitude of dimensional changes than that of stone. except in case of long autoclave cycle in medium and deep palate when silicone was not better than stone in dimensional change magnitude and this was illustrated in table 8. discussion dimensional stability of acrylic resins was regarded as an essential physical characteristic of the dental prosthesis to secure final configuration in oral services. the anatomical shape of the oral land marks which is reflected in its corresponding denture bases may leads to unorganized distortions linearly rendering the dentures functionally useless. (17) the effect of curing methods when water bath curing was applied, the acrylic resin processed at a temperature below the standard glass transition temperature, and when its cooled down to ambient temperature, internal stresses would be generated by shrinkage and distortion inside the resin mass. (18) so, during further processing at fast polymerization cycle, which means the final half an hour at 100°c of boiling water, release of the stored internal stresses within the resin mass occur. (19) also, further releasing of stresses from the flask opening leads to more distortion of the denture bases. (20) on the other hand, a high degree of variations in curing temperature by different positions of the flask within water bath machine, so heat is not uniformly distributed, leading to less degree of polymerization, higher ratio of residual monomer and less cross linking between polymer chains in some areas. so more dimensional changes will be resulted. (21) the short and long curing cycles during autoclave processing is characterized by more dimensional accuracy compared with conventional water bath and that’s because the uniform temperature distribution in the autoclave machine leads to spreading of heat more uniformly inside the mass and higher degree of cross linking between polymer macro-molecules, leading to formation of bridging structures connecting the linear polymer chains and formation of rigid and strong 3d network and less dimensional change when compared with the water bath. (22) also, the high pressure exerted during autoclave processing resulted in increasing the rate of reaction and raising the temperature of the monomer above boiling points so any excess monomer will be depleted, decreasing the dimensional changes of the cured acrylic resin by a higher degree of final polymerization. (23) the effect of the length of autoclave curing cycle the long one with stone investment showed better dimensional stability this could be explained by continuous heat supply from heat source which would be exaggerated by the exothermic nature of the polymerization reaction of the mass. so less residual monomer were present. although larger amount of internal stress were generated in the cured resin and when the curing time increased, the amount of the stresses increased too, but these stresses were restricted by the strong stone investment material. while for the short cycle, because of less curing time in both types of investments, more dimensional changes occurred, this may be due to more residual monomer. (24) the effect of investment the influence of stone on the degree of stress relaxation of denture base is very clear because this strong material is the hardest investment to deal with during flask opening and denture retrieving. it generates high stress inside the resin mass that will be later released during removing the denture from the cast. also, stone is subjected to expansion either by setting (0.15-0.25%) or by water sorption during flasking and curing in water bath when water molecules penetrate the semipreamble separating medium. (25) also, great variation in coefficient of thermal expansion j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 37 between stone cast (11*10-6) and acrylic resin (81*10-6) leads to formation of a gap between denture base and cast. (26) so, silicone is easier during investment removal because it has a moderate tear resistance so need scalpel to tear the mold and taking out the denture. (26) and as a result, investing with silicone will leads to better dimensional stability compared with stone. (14) as conclusion; autoclave curing procedure for acrylic resin is better when compared with traditional water bath curing. silicone investment had shown to be a good replacement to the conventional stone investment in multiple palatal depths. the long autoclave curing method is better than the short one especially when stone investment was used. references 1. shetty ns, udani tm. movements of artificial teeth in waxed trial dentures. j prosthet dent 1986; 56: 644-8. 2. nusavice kj. philips science of dental materials.11th ed. st. louis: elsevier; 2004. p. 739-41. 3. jackson te, knoll as. a contemporary review of the factors involved in the complete denture part i retention. j prosthet dent 1983; 49: 5-15. 4. heart well cm, ran aq. syllabus of complete denture. 2nd ed. philadelphia: lea and febinger; 1975. p. 4. 5. banerjee r, banerjee s, prabhudesai ps, bhide sv. influence of the processing technique on the flexural fatigue strength of denture base resins: an in vitro investigation. indian dent assoc 2010; 21: 391-5. 6. levin b, richardson gd. complete denture prosthodontics. a manual for clinical procedures. 17th ed. 2002. p. 54-55. 7. durkan r, ozel mb, bagis b, usanmaz a. in vitro comparison of autoclave polymerization on the transverse strength of denture base resins. dental materials j 2008; 27(4): 640-2. 8. lechner sk, thomas ga. changes caused by processing complete mandibular dentures. j prosthet dent 1994; 72: 606-13. 9. rizzati-barbosa cm, ribeiro-da-silva mc. influence of double flask investing and microwave heating on the superficial porosity, surface roughness, and knoop hardness of acrylic resin. j prosthodont 2009; 18: 5036. (ivls). 10. kazanje mn, noori sy. measurement of the palatal depth for completely edentulous patient. al-rafidain dent j 2008; 8(1): 23-5. 11. american dental association, specification no. 57, (2000). chicago il: ansi/ada. 12. shankar t, gowd s, ahmed st, vinod v, goud mv, rao nv. a comparative evaluation of the dimensional accuracy of heat polymerized acrylic resin denture base clamped by the conventional method and by newpress technique and cured by long curing cycle: an in vitro study. j contemp dent pract 2012; 13(6): 842-9. 13. abby a, kumar r, shibu j, chakravarthy r. comparison of the linear dimensional accuracy of denture bases cured by conventional method and by the new press technique. indian j dent res 2011; 22: 200-4. 14. wagner an, rafael lxc, marcus arlv, antonio md, lecio pp. the role of polymerization cycle and post pressing time on tooth movement in complete denture. braz dent j 2009; 23(4): 1-6. (ivls) 15. sajjad a. a comparative study of two different investment mediums on the movements of artificial teeth during the fabrication of complete dentures: an in vitro study. int j prosthet restor dent 2011; 1(3):1416. 16. abdulwahab ss, al-nakash wa. the effect of autoclave processing of heat cured denture base material. j bagh coll dentistry 2012; 24(3):13-17. 17. harrison a, huggett r, zissis a. measurements of dimensional accuracy using linear and scanning profile techniques. int j prosthodont 1992; 5: 68-72. 18. huggett r, brooks sc, campbell am, satguranathan r, bell ga. evaluation of analytical techniques for measurements of denture base acrylic resin glass transition temperature. dent mater 1990; 6:17-19. 19. polokoshko km, brudvik js, nicholls ji, smith de. evaluation of heat cured resin bases following the addition of denture teeth using a second heat cure. j prosthet dent 1992; 67: 556-62. 20. al-habali e, kallyway jp, howlett ja. acrylic denture distortion following double processing with microwave or heat. j dent 1991; 19(3): 176-80. 21. yau wef, chang yy, clark rkf, chow tw. pressure and temperature changes in heat cured acrylic resin during processing. dent mater j 2002; 18: 622-9. 22. nusavice kj. phillips’s sciences of dental materials." 11th ed. philadelphia: saunders co.; 2007. p. 162-9. 23. undurwade jh, sidhaye ab. curing acrylic resin in a domestic pressure cooker: a study of residual monomer content. quintessence int 1989; 20(2): 1239. 24. firtell dn, green aj, elahi jm. posterior peripheral seal distortion related to processing temperature. j prosthet dent1981; 45:598-601. 25. consani rlx, lira af, mesquita mf, consani s. linear dimensional change in acrylic resin disinfected by microwave energy. cienc odontol bras j 2006; 9: 34-9. 26. sunil a, rajashekar s, dayakra hr. comparative study on the fit of maxillary complete denture bases at the posterior palatal border made by heat cured acrylic resin processed on high expansion stone and type iii dental stone. int j dent clin 2011: 3(1):18-20. j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 38 table 1: descriptive statistics (mean differences and standard deviations) for the linear dimensional changes for a: water bath, b: short and c: long autoclave cycles. depth linear changes a water bath b short autoclave c long autoclave stone (control) silicone stone silicone stone silicone points mean sd mean sd mean sd mean sd mean sd mean sd shallow rt-rc 0.04 0.002 0.04 0.002 0.01 0.0005 0.03 0.0015 0.04 0.002 0 0 rc-p 0.01 0.0005 -0.03 -0.0015 -0.06 -0.003 -0.02 -0.001 0.04 0.002 -0.01 -0.0005 rt-v 0.05 0.0025 -0.01 -0.0005 0.06 0.003 0.03 0.0015 0.02 0.001 -0.05 -0.0025 lt-lc 0.01 0.0005 -0.03 -0.0015 -0.02 -0.001 -0.04 -0.002 -0.67 -0.0335 0.01 0.0005 lc-p 0.02 0.001 -0.02 -0.001 0.04 0.002 -0.01 -0.0005 -0.03 -0.0015 0.03 0.0015 lt-v -0.02 -0.001 0.06 0.003 -0.07 -0.0035 0.01 0.0005 0.03 0.0015 0.02 0.001 p-m -0.04 -0.002 0.05 0.0025 -0.01 -0.0005 0.02 0.001 0.03 0.0015 0 0 m-v 0.12 0.006 0.01 0.0005 -0.03 -0.0015 0.05 0.0025 0.05 0.0025 0.13 0.0065 rt-m -0.01 -0.0005 -0.05 -0.0025 0.02 0.001 0.01 0.0005 -0.02 -0.001 0.04 0.002 rc-m 0 0 0.04 0.002 0.04 0.002 -0.01 -0.0005 0.04 0.002 0.05 0.0025 lt-m 0.03 0.0015 0.04 0.002 0 0 0.02 0.001 -0.03 -0.0015 -0.01 -0.0005 lc-m -0.02 -0.001 0.05 0.0025 0.02 0.001 0.04 0.002 0.04 0.002 0 0 m edium rt-rc -0.03 -0.0015 -0.01 -0.0005 0.04 0.002 0.02 0.001 0.01 0.0005 -0.03 -0.0015 rc-p 0.03 0.0015 0 0 -0.01 -0.0005 -0.02 -0.001 -0.01 -0.0005 0.05 0.0025 rt-v 0.05 0.0025 -0.04 -0.002 -0.01 -0.0005 0.04 0.002 0.02 0.001 0.03 0.0015 lt-lc -0.01 -0.0005 -0.02 -0.001 0.04 0.002 0.01 0.0005 0.01 0.0005 -0.03 -0.0015 lc-p 0.04 0.002 0.06 0.003 0.01 0.0005 0.03 0.0015 0.02 0.001 0.05 0.0025 lt-v 0.37 0.0185 0.01 0.0005 0.04 0.002 -0.01 -0.0005 -0.02 -0.001 0.05 0.0025 p-m 0.03 0.0015 -0.04 -0.002 0.03 0.0015 -0.02 -0.001 -0.01 -0.0005 0.03 0.0015 m-v -0.01 -0.0005 0.08 0.004 0.03 0.0015 -0.03 -0.0015 -0.04 -0.002 0.03 0.0015 rt-m 0.03 0.0015 0.05 0.0025 0.02 0.001 0.01 0.0005 0.02 0.001 0.04 0.002 rc-m -0.02 -0.001 0.01 0.0005 -0.05 -0.0025 0.03 0.0015 0.02 0.001 -0.04 -0.002 lt-m 0 0 -0.02 -0.001 0.04 0.002 -0.04 -0.002 -0.02 -0.001 0.03 0.0015 lc-m 0.02 0.001 0.03 0.0015 0.04 0.002 0.02 0.001 -0.02 -0.001 0.04 0.002 d eep rt-rc 0.05 0.0025 0.04 0.002 -0.01 -0.0005 -0.04 -0.002 -0.02 -0.001 0.05 0.0025 rc-p 0.04 0.002 -0.05 -0.0025 -0.05 -0.0025 0.03 0.0015 -0.04 -0.002 0.02 0.001 rt-v -0.04 -0.002 0.08 0.004 -0.03 -0.0015 -0.01 -0.0005 -0.04 -0.002 0.04 0.002 lt-lc 0.05 0.0025 -0.03 -0.0015 0.01 0.0005 -0.04 -0.002 0.01 0.0005 -0.05 -0.0025 lc-p 0.01 0.0005 0.05 0.0025 -0.01 -0.0005 -0.02 -0.001 0.02 0.001 0.04 0.002 lt-v 0.01 0.0005 0.04 0.002 0.03 0.0015 0.01 0.0005 0.02 0.001 -0.05 -0.0025 p-m -0.04 -0.002 0 0 0 0 -0.02 -0.001 0.05 0.0025 -0.01 -0.0005 m-v 0.03 0.0015 0.02 0.001 -0.01 -0.0005 -0.01 -0.0005 0.02 0.001 0.04 0.002 rt-m 0.05 0.0025 -0.01 -0.0005 0.02 0.001 0.02 0.001 -0.03 -0.0015 0.03 0.0015 rc-m 0.01 0.0005 -0.03 -0.0015 0.02 0.001 -0.01 -0.0005 -0.04 -0.002 0.01 0.0005 lt-m 0.02 0.001 -0.02 -0.001 0.02 0.001 0.05 0.0025 0.01 0.0005 0 0 lc-m 0.02 0.001 -0.01 -0.0005 0.03 0.0015 -0.04 -0.002 -0.03 -0.0015 0.05 0.0025 j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 39 § mean decreasing changes £ means increasing changes and = means no changes. linear changes points f test between shallow & medium &deep stone silicone f test p value sig f test p value sig water bath rt-rc 36.56 p<0.01 hs 22.03 p<0.01 hs rc-p 30.44 p<0.01 hs 26.3 p<0.01 hs rt-v 44.23 p<0.01 hs 28.01 p<0.01 hs lt-lc 41.23 p<0.01 hs 25.09 p<0.01 hs lc-p 47.36 p<0.01 hs 12.3 p<0.01 hs lt-v 26.3 p<0.01 hs 33.3 p<0.01 hs p-m 25.02 p<0.01 hs 12.22 p<0.01 hs m-v 30.03 p<0.01 hs 14.52 p<0.01 hs rt-m 31.05 p<0.01 hs 21.03 p<0.01 hs rc-m 33.06 p<0.01 hs 22.5 p<0.01 hs lt-m 10.06 p<0.01 hs 30.03 p<0.01 hs lc-m 0.00 1.00 ns 12.22 p<0.01 hs short cycle rt-rc 15.33 p<0.01 hs 23.04 p<0.01 hs rc-p 30.2 p<0.01 hs 41.06 p<0.01 hs rt-v 33.03 p<0.01 hs 44.02 p<0.01 hs lt-lc 30.6 p<0.01 hs 23.33 p<0.01 hs lc-p 22.3 p<0.01 hs 20.9 p<0.01 hs lt-v 36.03 p<0.01 hs 19.05 p<0.01 hs p-m 15.6 p<0.01 hs 0.00 1.00 ns m-v 28.3 p<0.01 hs 30.3 p<0.01 hs rt-m 0.00 1.00 ns 44.03 p<0.01 hs rc-m 30.3 p<0.01 hs 45.02 p<0.01 hs lt-m 33.6 p<0.01 hs 22.03 p<0.01 hs lc-m 41.0 p<0.01 hs 26.3 p<0.01 hs long cycle rt-rc 12.22 p<0.01 hs 52.22 p<0.01 hs rc-p 14.52 p<0.01 hs 14.52 p<0.01 hs rt-v 21.03 p<0.01 hs 21.03 p<0.01 hs lt-lc 22.5 p<0.01 hs 23.68 p<0.01 hs lc-p 30.03 p<0.01 hs 30.03 p<0.01 hs lt-v 30.03 p<0.01 hs 30.03 p<0.01 hs p-m 33.3 p<0.01 hs 53.37 p<0.01 hs m-v 36.56 p<0.01 hs 36.56 p<0.01 hs rt-m 30.44 p<0.01 hs 30.44 p<0.01 hs rc-m 44.23 p<0.01 hs 44.23 p<0.01 hs lt-m 41.2 p<0.01 hs 41.23 p<0.01 hs lc-m 47.3 p<0.01 hs 47.36 p<0.01 hs linear changes lsd (linear) stone shallow & medium shallow & deep medium & deep p value sig ch p value sig ch p value sig ch water bath rt-rc p<0.01 hs § p<0.01 hs £ p<0.01 hs £ rc-p p<0.01 hs £ p<0.01 hs £ p<0.01 hs £ rt-v 1.00 ns = p<0.01 hs § p<0.01 hs § lt-lc 1.00 ns § p<0.01 hs £ p<0.01 hs £ lc-p p<0.01 hs £ p<0.01 hs § p<0.01 hs § lt-v p<0.01 hs £ p<0.01 hs £ p<0.01 hs § p-m p<0.01 hs £ 1.00 ns = p<0.01 hs § m-v p<0.01 hs § p<0.01 hs § p<0.01 hs £ rt-m p<0.01 hs £ p<0.01 hs £ p<0.01 hs £ rc-m p<0.01 hs § p<0.01 hs £ p<0.01 hs £ lt-m p<0.01 hs § p<0.01 hs § p<0.01 hs £ lc-m 1.00 ns £ 1.00 ns £ 1.00 ns = short cycle rt-rc p<0.01 hs £ p<0.01 hs § p<0.01 hs § rc-p p<0.01 hs £ p<0.01 hs £ p<0.01 hs § rt-v p<0.01 hs § p<0.01 hs § p<0.01 hs § lt-lc p<0.01 hs £ p<0.01 hs £ p<0.01 hs § lc-p p<0.01 hs § p<0.01 hs § p<0.01 hs § lt-v p<0.01 hs £ p<0.01 hs £ p<0.01 hs § p-m p<0.01 hs £ p<0.01 hs £ p<0.01 hs § m-v p<0.01 hs £ p<0.01 hs £ p<0.01 hs § rt-m 1.00 ns = 1.00 ns = 1.00 ns = rc-m p<0.01 hs § p<0.01 hs § p<0.01 hs £ lt-m p<0.01 hs £ p<0.01 hs £ p<0.01 hs § lc-m p<0.01 hs £ 1.00 ns £ p<0.01 hs § long cycle rt-rc p<0.01 hs § p<0.01 hs § p<0.01 hs § rc-p p<0.01 hs § p<0.01 hs § p<0.01 hs § rt-v 1.00 ns = p<0.01 hs § p<0.01 hs § lt-lc p<0.01 hs £ p<0.01 hs £ 1.00 ns = lc-p p<0.01 hs £ p<0.01 hs £ 1.00 ns = lt-v p<0.01 hs § p<0.01 hs § p<0.01 hs £ p-m p<0.01 hs § p<0.01 hs £ p<0.01 hs £ m-v p<0.01 hs § p<0.01 hs § p<0.01 hs £ rt-m 1.00 ns £ p<0.01 hs § p<0.01 hs § rc-m p<0.01 hs § p<0.01 hs § 1.00 ns § lt-m p<0.01 hs £ p<0.01 hs £ p<0.01 hs £ lc-m p<0.01 hs § p<0.01 hs § p<0.01 hs § table 3: lsd test for comparison between palatal depths (shallow, medium and deep) for all curing methods and stone investment for linear dimensional change. table 2: f test for comparison between the palatal depths (shallow, medium and deep) for all curing methods and investment materials for the linear dimensional changes. j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 40 linear changes lsd (linear) silicone shallow & medium shallow & deep medium & deep p value sig ch p value sig ch p value sig ch water bath rt-rc p<0.01 hs § 1.00 ns = p<0.01 hs £ rc-p p<0.01 hs £ p<0.01 hs § p<0.01 hs § rt-v p<0.01 hs § p<0.01 hs £ p<0.01 hs £ lt-lc p<0.01 hs £ 1.00 ns = p<0.01 hs § lc-p p<0.01 hs £ p<0.01 hs £ p<0.01 hs § lt-v p<0.01 hs § p<0.01 hs § p<0.01 hs £ p-m p<0.01 hs § p<0.01 hs § p<0.01 hs £ m-v p<0.01 hs £ p<0.01 hs £ p<0.01 hs § rt-m 1.00 ns £ p<0.01 hs £ p<0.01 hs § rc-m p<0.01 hs § p<0.01 hs § p<0.01 hs § lt-m p<0.01 hs § p<0.01 hs § 1.00 ns = lc-m p<0.01 hs § p<0.01 hs § p<0.01 hs § short cycle rt-rc p<0.01 hs § p<0.01 hs § p<0.01 hs § rc-p 1.00 ns = p<0.01 hs £ p<0.01 hs £ rt-v p<0.01 hs £ p<0.01 hs § p<0.01 hs § lt-lc p<0.01 hs £ 1.00 ns = p<0.01 hs § lc-p p<0.01 hs £ p<0.01 hs § p<0.01 hs § lt-v 1.00 ns § 1.00 ns = p<0.01 hs £ p-m 1.00 ns § 1.00 ns § 1.00 ns = m-v p<0.01 hs § p<0.01 hs § p<0.01 hs £ rt-m 1.00 ns = 1.00 ns £ 1.00 ns £ rc-m p<0.01 hs £ 1.00 ns = p<0.01 hs § lt-m p<0.01 hs § p<0.01 hs £ p<0.01 hs £ lc-m p<0.01 hs § 1.00 ns = p<0.01 hs £ long cycle rt-rc p<0.01 hs § p<0.01 hs £ p<0.01 hs £ rc-p p<0.01 hs £ p<0.01 hs £ p<0.01 hs § rt-v p<0.01 hs £ p<0.01 hs £ p<0.01 hs £ lt-lc p<0.01 hs § p<0.01 hs § p<0.01 hs § lc-p p<0.01 hs £ p<0.01 hs £ p<0.01 hs § lt-v p<0.01 hs £ p<0.01 hs § 1.00 ns § p-m p<0.01 hs £ p<0.01 hs § p<0.01 hs § m-v p<0.01 hs § p<0.01 hs § p<0.01 hs £ rt-m 1.00 ns = p<0.01 hs § p<0.01 hs § rc-m p<0.01 hs § p<0.01 hs § p<0.01 hs £ lt-m p<0.01 hs £ p<0.01 hs £ p<0.01 hs § lc-m p<0.01 hs £ p<0.01 hs £ p<0.01 hs £ linear changes points t test control & short cycle stone silicone ttest p value ch. ttest p value ch. shallow rt-rc 14.05 p<0.01 § 30.35 p<0.01 § rc-p 15.06 p<0.01 § 33.26 p<0.01 § rt-v 17.05 p<0.01 £ 12.35 p<0.01 § lt-lc 18.09 p<0.01 § 17.89 p<0.01 § lc-p 22.03 p<0.01 £ 34.26 p<0.01 § lt-v 13.25 p<0.01 § 30.35 p<0.01 £ p-m 13.47 p<0.01 £ 33.26 p<0.01 £ m-v 18.093 p<0.01 § 12.35 p<0.01 § rt-m 33.54 p<0.01 £ 1 ns £ rc-m 1 ns £ 1 ns § lt-m 1 ns § 10.25 p<0.01 § lc-m 1.00 ns £ 10.08 p<0.01 £ medium rt-rc 23.54 p<0.01 £ 10.05 p<0.01 £ rc-p 44.06 p<0.01 § 11.23 p<0.01 § rt-v 45.09 p<0.01 § 11.98 p<0.01 § lt-lc 88.04 p<0.01 £ 15.09 p<0.01 £ lc-p 13.24 p<0.01 § 15.47 p<0.01 § lt-v 31.24 p<0.01 § 16.07 p<0.01 § p-m 1.00 ns = 16.97 p<0.01 § m-v 27.67 p<0.01 £ 17.36 p<0.01 § rt-m 24.68 p<0.01 § 22.9 p<0.01 § rc-m 30.14 p<0.01 § 12.65 p<0.01 £ lt-m 1 ns £ 14.02 p<0.01 § lc-m 27.45 p<0.01 £ 1.00 ns = deep rt-rc 10.12 p<0.01 § 30.25 p<0.01 § rc-p 14.05 p<0.01 § 20.14 p<0.01 § rt-v 13.21 p<0.01 £ 17.00 p<0.01 £ lt-lc 33.24 p<0.01 § 18.08 p<0.01 § lc-p 27.45 p<0.01 § 14.99 p<0.01 § lt-v 19.35 p<0.01 £ 1 ns = p-m 1 ns £ 66.35 p<0.01 £ m-v 22.31 p<0.01 § 45.69 p<0.01 § rt-m 24.18 p<0.01 § 69.35 p<0.01 § rc-m 17.89 p<0.01 £ 23.21 p<0.01 § lt-m 1.00 ns = 13.57 p<0.01 £ lc-m 23.17 p<0.01 £ 12.37 p<0.01 £ table 4: lsd test for comparison between palatal depths (shallow, medium and deep) for all curing methods and silicone investment for linear dimensional change. table 5: t-test for comparison between control and short autoclave cycles for all palatal depths and both investment materials. j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 41 linear changes points t-test control & long cycle stone silicone t-test p value ch. t-test p value ch. shallow rt-rc 1.00 ns = 1.00 ns § rc-p 27.89 p<0.01 £ 1.00 ns § rt-v 12.34 p<0.01 § 1.00 ns § lt-lc 44.25 p<0.01 § 1.00 ns = lc-p 46.28 p<0.01 § 20.05 p<0.01 £ lt-v 25.69 p<0.01 £ 1.00 ns £ p-m 47.08 p<0.01 £ 1.00 ns £ m-v 19.87 p<0.01 § 2.35 0.042 £ rt-m 30.25 p<0.01 § 13.09 p<0.01 £ rc-m 1 ns £ 1.00 ns £ lt-m 1.00 ns § 23.89 p<0.01 § lc-m 10.17 p<0.01 £ 1.00 ns £ medium rt-rc 12.36 p<0.01 £ 1.00 ns = rc-p 15.29 p<0.01 § 27.27 p<0.01 £ rt-v 22.35 p<0.01 § 26.29 p<0.01 § lt-lc 28.97 p<0.01 £ 56.28 p<0.01 § lc-p 24.26 p<0.01 § 30.08 p<0.01 £ lt-v 23.58 p<0.01 § 17.25 p<0.01 § p-m 19.87 p<0.01 § 1.00 ns = m-v 30.24 p<0.01 § 12.04 p<0.01 £ rt-m 31.47 p<0.01 § 13.06 p<0.01 £ rc-m 1.00 ns £ 17.89 p<0.01 § lt-m 1 ns § 1.00 ns £ lc-m 1.00 ns § 30.56 p<0.01 £ deep rt-rc 10.15 p<0.01 § 1.00 ns = rc-p 1.00 ns § 10.06 p<0.01 § rt-v 1.00 ns = 1.00 ns £ lt-lc 10.12 p<0.01 § 23.08 p<0.01 § lc-p 11.02 p<0.01 £ 17.89 p<0.01 £ lt-v 12.05 p<0.01 £ 81.30 p<0.01 § p-m 1 ns £ 71.31 p<0.01 £ m-v 13.05 p<0.01 § 23.56 p<0.01 £ rt-m 15.89 p<0.01 § 45.12 p<0.01 § rc-m 13.42 p<0.01 § 1.00 ns = lt-m 15.69 p<0.01 § 1.00 ns § lc-m 14.87 p<0.01 § 20.38 p<0.01 £ linear changes points t-test short & long cycle stone silicone t-test p value ch. t-test p value ch. shallow rt-rc 27.44 p<0.01 £ 1.00 ns § rc-p 15.69 p<0.01 £ 18.88 p<0.01 £ rt-v 23.44 p<0.01 § 12.35 p<0.01 § lt-lc 18.98 p<0.01 § 22.58 p<0.01 £ lc-p 23.54 p<0.01 § 28.98 p<0.01 £ lt-v 44.58 p<0.01 £ 10.11 p<0.01 £ p-m 10.28 p<0.01 £ 1.00 ns § m-v 13.98 p<0.01 £ 11.25 p<0.01 £ rt-m 25.90 p<0.01 § 28.97 p<0.01 £ rc-m 1.00 ns = 14.01 p<0.01 £ lt-m 1.00 ns § 14.56 p<0.01 § lc-m 23.03 p<0.01 £ 1.00 ns § medium rt-rc 1.00 ns § 10.66 p<0.01 § rc-p 1.00 ns = 10.87 p<0.01 £ rt-v 47.25 p<0.01 £ 9.099 p<0.01 § lt-lc 12.98 p<0.01 § 8.97 p<0.01 § lc-p 23.03 p<0.01 £ 11.23 p<0.01 £ lt-v 22.09 p<0.01 § 15.04 p<0.01 £ p-m 25.36 p<0.01 § 14.22 p<0.01 £ m-v 45.89 p<0.01 § 23.65 p<0.01 £ rt-m 1.00 ns = 54.36 p<0.01 £ rc-m 18.97 p<0.01 £ 18.97 p<0.01 § lt-m 12.31 p<0.01 § 12.31 p<0.01 £ lc-m 11.89 p<0.01 § 30.01 p<0.01 £ deep rt-rc 8.25 p<0.01 § 10.14 p<0.01 £ rc-p 78.98 p<0.01 £ 10.87 p<0.01 § rt-v 11.25 p<0.01 § 30.21 p<0.01 £ lt-lc 1.00 ns = 15.98 p<0.01 § lc-p 22.34 p<0.01 £ 41.36 p<0.01 £ lt-v 28.90 p<0.01 § 23.78 p<0.01 § p-m 1.00 ns £ 12.35 p<0.01 £ m-v 18.97 p<0.01 £ 26.54 p<0.01 £ rt-m 18.97 p<0.01 § 18.97 p<0.01 £ rc-m 23.25 p<0.01 § 17.14 p<0.01 £ lt-m 18.74 p<0.01 § 1.00 ns § lc-m 23.65 p<0.01 § 20.31 p<0.01 £ table 7: t-test for comparison between short and long autoclave cycles for all palatal depths and both investment materials table 6: t-test for comparison between the control and long autoclave cycles for all palatal depths and both investment materials. j bagh college dentistry vol. 27(2), june 2015 estimation of the restorative dentistry 42 table 8: t-test for comparison between the stone and silicone investment materials for a: water bath, b: short cycle and c: long cycle. *p < 0.05 significant, **p > 0.05 non significant, ***p< 0.01 high significant. linear changes points a b c water bath short cycle long cycle t-test p-value ch t-test p-value ch t-test p-value ch shallow rt-rc 1.00 ns = 14.25 p<0.01 £ 1.00 ns § rc-p 12.36 p<0.01 § 10.12 p<0.01 £ 10.24 p<0.01 § rt-v 17.25 p<0.01 § 10.36 p<0.01 § 11.28 p<0.01 § lt-lc 22.03 p<0.01 § 11.25 p<0.01 § 13.65 p<0.01 £ lc-p 1.00 ns § 13.65 p<0.01 § 9.02 p<0.01 £ lt-v 25.69 p<0.01 £ 12.31 p<0.01 £ 9.22 p<0.01 § p-m 56.36 p<0.01 £ 22.34 p<0.01 £ 1.00 ns § m-v 45.69 p<0.01 § 18.74 p<0.01 £ 9.87 p<0.01 £ rt-m 23.36 p<0.01 § 23.14 p<0.01 § 18.62 p<0.01 £ rc-m 1.00 ns £ 10.28 p<0.01 § 18.74 p<0.01 £ lt-m 23.58 p<0.01 £ 1.00 ns £ 18.03 p<0.01 £ lc-m 10.04 p<0.01 £ 17.89 p<0.01 £ 1.00 ns § medium rt-rc 25.08 p<0.01 £ 27.23 p<0.01 § 11.24 p<0.01 § rc-p 26.29 p<0.01 § 28.26 p<0.01 § 15.24 p<0.01 £ rt-v 27.04 p<0.01 § 10.24 p<0.01 £ 32.32 p<0.01 £ lt-lc 30.25 p<0.01 § 18.97 p<0.01 § 14.56 p<0.01 § lc-p 14.89 p<0.01 £ 18.62 p<0.01 £ 10.19 p<0.01 £ lt-v 78.90 p<0.01 § 16.32 p<0.01 § 10.47 p<0.01 £ p-m 36.58 p<0.01 § 23.24 p<0.01 § 41.36 p<0.01 £ m-v 22.36 p<0.01 £ 15.64 p<0.01 § 18.03 p<0.01 £ rt-m 20.04 p<0.01 £ 18.14 p<0.01 § 23.33 p<0.01 £ rc-m 21.05 p<0.01 £ 17.23 p<0.01 £ 24.30 p<0.01 § lt-m 1.00 ns § 18.97 p<0.01 § 24.87 p<0.01 £ lc-m 22.89 p<0.01 £ 10.25 p<0.01 § 25.3 p<0.01 £ deep rt-rc 17.05 p<0.01 § 13.21 p<0.01 § 8.99 p<0.01 £ rc-p 22.09 p<0.01 § 13.25 p<0.01 £ 8.78 p<0.01 £ rt-v 28.63 p<0.01 £ 15.26 p<0.01 £ 12.25 p<0.01 £ lt-lc 54.26 p<0.01 § 14.25 p<0.01 § 23.14 p<0.01 § lc-p 30.69 p<0.01 £ 18.14 p<0.01 § 25.36 p<0.01 £ lt-v 44.05 p<0.01 £ 10.02 p<0.01 § 14.32 p<0.01 § p-m 1.00 ns £ 1.00 ns § 10.35 p<0.01 § m-v 17.08 p<0.01 § 1.00 ns = 18.95 p<0.01 £ rt-m 59.36 p<0.01 § 1.00 ns = 25.36 p<0.01 £ rc-m 31.05 p<0.01 § 9.014 p<0.01 § 18.78 p<0.01 £ lt-m 1.00 ns § 8.98 p<0.01 £ 1.00 ns § lc-m 18.09 p<0.01 § 7.87 p<0.01 £ 25.98 p<0.01 £ shahba'a.doc j bagh college dentistry vol. 28(1), march 2016 nutritional status pedodontics, orthodontics and preventive dentistry 147 nutritional status among a group of preschool children in relation to concentration of selected elements in saliva and caries severity (a comparative study) shahba’a munther, b.d.s, m.sc. (1) ali y. majid, m.b.ch.b., m.sc., f.i.c.m.s. (2) abstract background: nutritional status during childhood is very important for individual development and growth. nutrition has local and systemic effect on the oral health by affecting dental health and salivary composition. this study was aimed to determine effect of iron, sodium and potassium ions in saliva on the nutritional status and to determine the effect of nutritional status on caries severity among preschool children. material and methods: the sample consists of 90 children aged 4 and 5 years of both genders, selected from 6 kindergartens in al-resafa aspect of baghdad province. children classified according to their nutritional status into three groups (normalweight, underweight and overweight). nutritional status was determined by using body mass index bmi that achieved from height and weight (weight (kg)/height (m)2). assessment and recording of caries experience was done by the application of decayed, missing, filled index (dmfs for primary teeth). the diagnosis of dental caries was done according to (d1-4 mfs) criteria for primary teeth. stimulated saliva was collected from children between 9-11 am under standardized conditions and chemically analyzed to determine the concentration of iron, sodium and potassium calorimetrically by using ready-made kits and spectrophotometer machine. data were analyzed using spss version 19. results: concentration of sodium, potassium and iron ions were (46.64 mg/dl ± 18.00, 31.22 mg/dl ± 9.84, 17.76µg/dl ± 3.17) respectively. from the elements measured in saliva only sodium ions recorded statistically significant difference among the three groups of nutritional status. by application of lsd, the significant difference was found to be between normal weight and overweight groups (46.33 mg/dl ± 17.18, 40.64 mg/dl ± 14.79) respectively (p<0.05). furthermore, positive and statistically significant correlations were recorded between sodium ions with bmi mean of overweight group on one hand (r=0.125, p<0.05) and iron ions and normal weight group on other hand (r=0.362, p<0.05). recording and diagnosis of dental caries showed that means of ds, ms, dmfs, d2s and d4s were significantly higher among children aged 5 years than those aged 4 years. in addition to that means of ds, ms, dmfs and d2s were significantly differ among the three groups of nutrition. application of lsd test showed that those means were higher among underweight group than others. conclusion: concentration of sodium ions in saliva changed according to nutritional status. on the other hand nutritional status may affect caries severity, where underweight children suffering from dental caries more than normalweight and overweight children. key words: nutritional status, concentration of iron, sodium and potassium in saliva, severity of caries. (j bagh coll dentistry 2016; 28(1):147-152). introduction nutritional status is an assessment of level of nutrients in the body of a patient or subject and their ability to maintain normal metabolic integrity (1,2). excess or deficiency of one or more of the essential nutrients may result in deleterious effects on the subject health (3,4). oral and dental health reflects the nutritional status of the body, where there is a complex relationship among oral health, general health and nutritional status with many interrelating factors (5,6). dental caries remain the most public oral health disease especially among children (7). nutritional status has local and systemic effect in the etiology and pathogenesis of dental caries (8,9). on the other hand inorganic composition of saliva including major and trace elements plays an important role in caries process and mineralization of teeth (10,11). (1)assistant lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)consultant. drugs and poisoning center. iraq. there is an interrelationship between elements in saliva and nutritional status, where some of these elements as zinc were changed with alteration in nutritional status (6, 12, 13). there is a limitation in the studies concerning these aspects. for all of the above and in order to increase knowledge about the effect of certain element in saliva on the nutritional status on one hand and the effect of nutritional status on caries severity on the other hand, this study was conducted. materials and methods the study group sample involved in this study consisted of 90 children aged 4 and 5 years of both genders selected from 6 kindergartens in al-resafa aspect of baghdad province. those children were selected according to their body mass index to determine their nutritional status, in order to be classified into three groups (normal weight group, underweight group and overweight group), each group was consist of 30 children to compare j bagh college dentistry vol. 28(1), march 2016 nutritional status pedodontics, orthodontics and preventive dentistry 148 between them. for each volunteers parents the objectives of the study were explained to, and they approved to participate. assessment of nutritional status nutritional status of each child was assessed by using body mass index bmi that represents a number calculated from weight and height according to the following formula: bmi =weight [kg] height [meter] 2 there was no bmi database available for iraqis to compare results so, the reference population defined by the national centre for health statistics, in collaboration with the national centre for chronic disease prevention and health promotion was used. bmi value crossed against age on special charts one prepared for boys and the other prepared for girls, to determine the nutritional status of each child involved in this study. collection of saliva and recoding of caries stimulated saliva was collected from children between 9-11 am. each child was asked not to eat or drink (except water) 1 hour before collection, then each child was sited in relaxed position without any heavy physical stress and was asked to chew apiece of arabic gum (0.35 0.4 gm.) for one minute then to remove all saliva by expectoration. chewing was continued for five minutes, with the same piece of gum and saliva collected in sterile screw capped bottle (14). each salivary sample was then centrifuged by centrifugater at 3000 r.p.m. (revolution per minute) for 10 minutes. salivary supernatant was stored at (-20ºc) in polyethylene tubes for subsequent chemical analysis. clinical examination of teeth was conducted by using plan mouth mirror and dental explorer. assessment and recording of caries experience was done by the application of decayed, missing, filled index (dmfs for primary teeth). the diagnosis of dental caries was according to (d1-4 mfs) criteria for primary teeth (15). analysis of salivary sample and data concentrations of sodium, potassium and iron in saliva were determined by using readymade kits (mguranylacetatmethod, human biochemica, germany) for sodium ,(photometric turbidimetric test, human biochemica, germany) for potassium and (lipid clearing factor (lcf) cab method, human biochemica, germany) for iron, and analyzed by uv visible recording spectrophotometry (cecil ce 7200 uk) machine. chemical analysis was carried out at poisoning consultation center, medical city. data were analyzed by using spss software version 19 (statistical package for social sciences) by application of both descriptive statistic including (number, percentage, mean and stander deviation) and interferential statistic including (analysis of variance (one way anova test), student's t-test and person's correlation coefficient). results total number of sample was 90; 30 of them were aged 4 years and 60 of them were aged 5years. boys represent 61.12% of total sample, while girls represent 38.88% of total sample as shown in table (1). sample was distributed into three groups according to nutritional status (normalweight, underweight and overweight) each group consists of 30 children. boys aged 5years were the highest in number in both normalweight and underweight groups, while girls aged 4 years were the smallest in number in these two groups. in overweight group an equal numbers of both ages and both genders were recorded as shown in table (2). results recorded in table (3) showed that differences in means of concentrations of iron ions (ferrous ions) and potassium ions, were not significant for the studied nutritional groups (normalweight, underweight, overweight), while significant difference was recorded for mean of concentration of sodium ions among the three groups of nutritional status (p< 0.05) with highest concentration among overweight group. furthermore, positive weak and statistically significant correlations were recorded between concentration of fe ions in saliva and bmi of normal weight group, and between concentration of na ions in saliva and bmi of overweight group as recorded in table (4). regarding caries experience among those children, results showed that 21.11% of them were caries free, while for the other 79.99% of children involved in this study, statistically significant differences were recorded between children aged 4 years and those aged 5 years for means of ds, ms and d4s (p < 0.05), in addition to that highly significant differences were recorded between these ages for means of dmfs and d4s (p < 0.01). while all differences recorded between boys and girls were statistically not significant as shown in table (5). according to the results recorded in table (6), significant differences in means of ds, fs and d2s fractions were recorded among the three groups of nutritional status. after application of lsd j bagh college dentistry vol. 28(1), march 2016 nutritional status pedodontics, orthodontics and preventive dentistry 149 significant difference was found to be between underweight on one hand and normalweight and overweight groups on the other hand (p<0.05), furthermore; highly significant difference was recorded for means of dmfs among the same groups (p < 0.01). table 1: distribution of sample according to age and gender table 2: distribution of sample according to nutritional status (in number and percentage of each group) described by age and gender table 3: concentration of measured elements in saliva according to nutritional status (mean and stander deviation) and differences between them sd=stander deviation, significance level at p < 0.05 table 4: correlations between (iron, sodium and potassium) in saliva and bmi in each nutritional tatus significance level at p < 0.05 discussion nutritional status during childhood is very important for subsequent growth and development of individuals (2,3), so this study was conducted among preschool children aged 4 and 5 years. by studying the effect of elements in saliva on the nutritional status of children, results showed that the difference in concentrations of fe and k ions in saliva were statistically not significant among the studied nutritional groups. there is a controversy among iraqi studies regarding salivary level of these two elements. iraqi study conducted on school aged children found that salivary iron level was lower among overweight than that of normal weight (12). on the other hand potassium level was lower among malnourished than well-nourished kindergarten children (16). age of group in years boys girls both no. % no. % no. % 4 years 17 18.89 13 14.44 30 33.33 5 years 38 42.23 22 24.44 60 66.67 both 55 61.12 35 38.88 90 100.00 nutritional status normal weight under weight over weight age gender no. % no. % no. % 4 years boys 3 10.00 3 10.00 10 33.33 girls 4 13.33 4 13.33 5 16.67 both 7 23.33 7 23.33 15 50.00 5 years boys 14 46.67 15 50.00 10 33.33 girls 9 30.00 8 26.67 5 16.67 both 23 76.67 23 76.67 15 50.00 both ages 30 100 30 100 30 100 nutritional status elements normal weight under weight over weight anova test total mean ± sd mean ± sd mean ± sd f sig. mean ± sd iron (i) µmol/l 17.40 ± 3.02 18.36 ± 3.24 17.61 ± 3.45 0.237 not 17.76 ± 3.17 sodium (na) mmol/l 46.33 ± 17.18 46.06 ± 18.28 40.64 ± 14.79 2.538 sig 46.64 ± 18.00 potassium (k) mmol/l 29.25 ± 9.77 30.65± 9.85 31.51 ± 8.09 0.220 not 31.22 ± 9.84 nutritional status elements normal weight under weight over weight r sig r sig r sig iron (i) µmol/l 0.362 sig 0.183 not 0.114 not sodium (na) mmol/l 0.016 not 0.003 not 0.125 sig potassium (k) mmol/l 0.145 not 0.187 not 0.368 not j bagh college dentistry vol. 28(1), march 2016 nutritional status pedodontics, orthodontics and preventive dentistry 150 table 5: caries experience among children by age and gender significance level at p < 0.05 highly significance level at p < 0.01 table 6: caries-experience among children in relation to nutritional status (in mean and standard deviation) and differences between means significance level at p <0.05 highly significance level at p <0.01 so to understand the role of these tow ions further studies may be indicated. the concentration of na ions in saliva of overweight group was significantly higher than that of normalweight. on the other hand sodium level in saliva recorded no significant difference between malnourished and well-nourished children as mentioned by other iraqi study (16). this result was agreed with result achieved in this study. in addition to that, by application of person's correlation coefficient between bmi of each nutritional group and concentration of these elements in saliva, na ions showed positive correlation that was statistically significant with bmi of overweight group. although this correlation was weak, but this result in addition to that achieved by analysis of variance (anova) gave an indication that na ions in saliva may be increase with increase in bmi. fraction age gender 4 years 5 years both ages t-test for ages t-test for gender mean ± sd mean ± sd mean ± sd t sig t sig ds boys 3.87 ± 5.29 6.10 ± 5.23 5.45 ± 5.30 2.36 sig 1.05 not girls 4.00 ± 3.70 8.41 ± 7.20 6.77 ± 6.44 both 3.93 ± 4.57 6.93 ± 6.06 5.97 ± 5.77 ms boys 0.00 ± 0.00 0.95 ± 2.11 0.67 ± 1.82 2.44 sig 0.26 not girls 0.00 ± 0.00 0.91 ± 1.97 0.57 ± 1.61 both 0.00 ± 0.00 6.93 ± 2.04 0.63 ± 1.73 fs boys 0.75 ± 2.49 0.82 ± 1.98 0.80 ± 2.12 1.07 not 0.00 not girls 0.08 ± 0.27 1.23 ± 2.74 0.80 ± 2.23 both 0.45 ± 1.86 0.97 ± 2.27 0.80 ± 2.15 dmfs boys 4.63 ± 7.48 7.87 ± 5.96 6.93 ± 6.54 3.25 highly 0.64 not girls 3.38 ± 3.82 10.55 ± 7.64 7.89 ± 7.31 both 4.07 ± 6.05 8.84 ± 6.64 7.30 ± 6.83 d1s boys 1.56 ± 1.99 1.38 ± 1.54 1.44 ± 1.67 1.14 not 0.50 not girls 1.77 ± 1.96 0.95 ± 1.32 1.26 ± 1.61 both 1.66 ± 1.95 1.23 ± 1.47 1.37 ± 1.64 d2s boys 0.75 ± 1.39 3.23 ± 2.96 2.51 ± 2.82 2.98 highly 1.56 not girls 1.92 ± 2.01 5.00 ± 6.32 3.86 ± 5.33 both 1.28 ± 1.77 3.87 ± 4.50 3.03 ± 4.01 d3s boys 0.56 ± 1.36 0.59 ± 1.42 0.58 ± 1.39 1.36 not 1.43 not girls 0.31 ± 0.63 1.50 ± 1.99 1.06 ± 1.71 both 0.45 ± 1.08 0.92 ± 1.69 0.77 ± 1.53 d4s boys 0.00 ± 0.00 0.90 ± 2.28 0.64 ± 1.95 2.16 sig 0.08 not girls 0.00 ± 0.00 0.95 ± 2.34 0.60 ± 1.89 both 0.00 ± 0.00 0.92 ± 2.28 0.62 ± 1.92 nutritional status fraction of caries nutritional status normal weight under weight over weight anova mean ± sd mean ± sd mean ± sd f sig. ds 4.70 ± 4.62 8.53 ± 7.60 4.67 ± 3.60 4.249 sig ms 0.47 ± 1.43 1.10 ± 2.29 0.33 ± 1.26 2.360 not fs 0.77 ± 1.94 1.43 ± 3.05 0.20 ± 0.55 2.950 sig dmfs 5.63 ± 5.79 11.07 ± 8.55 5.20 ± 3.78 7.664 highly sig d1s 1.23 ± 1.59 1.07 ± 1.59 1.80 ± 1.71 0.572 not d2s 2.60 ± 2.60 4.97 ± 5.74 1.53 ± 1.83 4.790 sig d3s 0.57 ± 1.22 0.87 ± 1.59 0.87 ± 1.77 0.220 not d4s 0.30 ± 1.14 1.10 ± 2.51 0.47 ± 1.77 0.883 not j bagh college dentistry vol. 28(1), march 2016 nutritional status pedodontics, orthodontics and preventive dentistry 151 no previous study had been conducted regarding the relation between sodium ions in saliva and nutritional status particularly overweight condition, to compare the result with. however, it had been found that, increase in serum sodium level, result in further uptake of water to maintain a balance between sodium and water level in serum and this may increase body weight (17,18) . this fact may support result achieved in this study. the concentration of fe ions in saliva of normalweight group recorded positive and statistically significant correlation with bmi of this group. this result was agreed with fact that, iron deficiency may result in malnutrition condition and lose of body weight(19). this result may indicate that when iron present in sufficient amount; healthy weight could achieve as reflected by salivary picture. regarding caries severity among those children, the means of (ds) that represent the present disease, (ms) that represent the accumulative effect of dental caries and (dmfs) that represent the caries experience; were significantly higher among children aged 5 years than these of 4 years. on the other hand means of (d2s) that represent initiation of caries, and (d4s) that represent progression of caries to the deeper tooth layers, were also significantly higher among children aged 5 years than these of 4 years. all of these results could explained by that, teeth of children aged 5 years exposed to oral environment and cariogenic factors for longer period of time than teeth of children aged 4 years that no longer had been erupted. it was well established that caries severity increase with age due to accumulative and irreversible nature of dental caries (20). concerning the effect of nutritional status on caries severity, results showed that caries experience and severity were significantly higher among underweight children than that of both normal weight and overweight. the same results were achieved by other iraqi studies (16, 21). underweight children may take inadequate amount of essential nutrient that may affect composition of teeth as 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ferrante m, et al. health effects of metals and related substances in drinking water. iwa, 2015. 20. hassan zs. oral health status and treatment need among institutionalized iraqi children and adolescents in comparison to school children and adolescents in j bagh college dentistry vol. 28(1), march 2016 nutritional status pedodontics, orthodontics and preventive dentistry 152 iraq. master thesis, college of dentistry, university of baghdad, 2002. 21. jabber wm. oral health status in relation to nutritional status among kindergarten children 4-5 years in al-kut city/iraq. master thesis, college of dentistry, university of baghdad, 2008. 22. levine m. topics of dental biochemistry. 1st ed. germany: springer, heidelberg; 2011. suha.doc j bagh college dentistry vol. 28(1), march 2016 an antimicrobial basic sciences 183 an antimicrobial activity of moringa oleifera extract in comparison to chlorhexidine gluconate (in vitro study) khulood majid alsaraf, b.sc., m.sc., ph.d. (1) suha t. abd, b.d.s., m.sc. (2) nada s. husain, b.sc. (3) abstract background: oral diseases persist to be a major health problem all over the world. various bacteria and fungi are found to be the possible pathogensresponsible for the oral diseases. moringa oleifera it is an extraordinary nutritious vegetable tree with many different uses. these leaves have high medicinal value. in the present study, antibacterial and antifungal activities of aqueous extracts of plant moringa oleifera in comparison to chlorohexidene gluconate and deionized water were determined. materials and methods: the leaves of plant of moringa oleifera were collected from college of pharmacy; baghdad, iraq. tested microorganism (bacterial and fungal) was isolated from different clinical specimens. in-vitroantimicrobial activity was performed by agar well diffusion method on muller hinton agar medium. results: the water extract of moringa oleiferashowed antibacterial effect on the tested organisms: staphylococcus aureus, streptococcus spp. and enterococcus faecalis. aqueous extract showed maximum zone of inhibition against s.aureus. conclusion: moringa olifera can be used as safe and cheap plant antimicrobial agent. key words: moringa oleifera, antimicrobial effect, chlorohexidene gluconate. (j bagh coll dentistry 2016; 28(1):183187). introduction moringa oleifera commonly referred as moringa only. it is an extraordinary nutritious vegetable tree with many different uses. these leaves have high medicinal value (1). moringa oleifera found in any tropical and subtropical country with strange environmental features, like dry to moist tropical or subtropical weather, with annual precipitation of 760 to 2500 mm and temperature 18 and 28 °c. it cultivates in any type of soil, but dense clay and saturated with water, and the ph range between 4.5 and 8, at an elevation up to 2000 m is more preferable environment (2). conventional medicines turn into a chief source of main health to majority of people in most developed country, particularly in africa due to cheapness and feasibility of antibiotic furthermore antibiotic resistance and side effect of them (3). many epidemiological studies have indicated that m. oleifera leaves are a well source of nutrition and exhibit anti-tumor, antiinflammatory, anti-ulcer, anti-atherosclerotic and anti-convulsing activities (4-6). olden egyptians consumed moringa oleifera oil for its improving worth and dermatological ground work (7).today, moringa oleifera and its byproducts are dispensed chiefly in middle east, asian and african countries (8), and are still dispersion to other regions. (1)assistant professor. department of basic sciences, college of dentistry, university of baghdad. (2) assistant lecturer. department of basic sciences, college of dentistry, university of baghdad. (3)biologist. teaching lab., medical city. chlorhexidine gluconate (chx) is cationic biguanide that act on cell wall of microorganism by adsorbing on it resulting in leakage of intracellular components. furthermore, because of its cationic structure, chlorhexidine has the unique property of substantively. at low concentration it is bacteriostatic and at a high concentration it is bactericidal (9). chlorhexidine gluconate was tested against common oral pathogens like streptococcus mutans and enterococcus faecalis and showed considerable antibacterial activities especially against staphylococcus aureus (10). the leaves of moringa oleifera are highly nutritious, it considered a considerable source of beta-carotene, protein, vitamin c, potassium and iron (11). moringa leaves contains phytochemical having potent anticancer and hypotensive activity and are considered full of medicinal properties (12). the whole moringa oleifera plant is used in the treatment of psychosis, eye diseases and fever (13). this study aimed to show antimicrobialactivity ofwater extracts of the moringa oleifera against different oral and other pathological microorganism in comparison to chlorhexidine gluconate. materials and methods collection of plant material the leaves of plant of moringa oleifera were collected from college of pharmacy, baghdad, iraq (figure 1). it was ensured that the plant was healthy and uninfected. the leaves were washed j bagh college dentistry vol. 28(1), march 2016 an antimicrobial basic sciences 184 under running tap water followed by distilled water to eliminate dust and other foreign particles and shade dried for 5 days to remove water. the dried leaves and stems were powdered and stored in air tight containers until use. figure 1: leaves of moringa oleifera plant preparation of extract (aqueous extraction) twenty grams of dried powered plant material (leaves and stems) were soaked separately in 200 ml double distilled water (ddw), kept on a rotary shaker for 24 hours. then after, these were kept at slow heat for 8 h and then filtered through eight layers of muslin cloth. the resultant liquid was subsequently centrifuged at rate 7000 rpm for 15 minutes. the supernatant part was collected and then concentrated by evaporation at 50°c to make the final volume one-twentieth of the original volume (10 ml). the extract was then autoclaved at 121°c and 15 lbs. pressure, and stored in sealed tubes at 4°c until use.this is preparation for the stock solution (100 % concentration). from this stock solution prepare different dilutions (20%, 40%, 60%, 80%), by using dilution law (n1v1 =n2v2), diluted by addition distill water to the stock solution. test organisms tested microorganism (bacterial and fungal) was isolated from different clinical specimens; the isolation and identification of the samples was according to typical laboratory methods (14). isolated bacteria include: gram negative bacteria (salmonella spp, escherichiacoli and klebsiella pneumonia) gram positive bacteria (streptococcus spp, enterococcus faecalis, staphylococcus aureus). isolated fungi include: candida albicans. bacterial and fungal media (agar media) muller hinton agar prepared according to manufacturer's instruction which involved the suspension of 38 gm. in one liter of de-ionized water, after being completely dissolved with boiling, it was sterilized by autoclave at 15 lb. pressure for 15 minutes, then left to cool at 45 50oc, poured and left to solidify then put them in incubator at 37°c for 24 hours then stored in refrigerator until being used. antimicrobial screening (in vitro) the antimicrobial activity of the moringa oleifera, chlorohexidene gluconate and deionized water were measured by well diffusion method(15,16). the prepared culture plates wereinoculated with different selected strains ofbacteria and fungi using spreading method.wells were made on the agar surface with 6 mm cork borer. the position of the wells for each extract was marked at the outside walls of plates before application of plant extracts, chlorohexidene gluconate and deionized water. the extracts were poured into the well. each well was filled with 100µl with corresponding extract with the help of a micropipette. the plates were incubated at 37±2 ºc for 24 hours for bacterial and 25±2 ºc for 48 hours for fungal activity. the plates were observed for the zone clearance around the wells. the resulting inhibition zones were uniformly circular. the diameters of the zones of inhibition were measured, including the diameter of the well. inhibition zones are measured to the nearest millimeter, using a ruler, which is held on the back of the inverted petri plate. results this study entails the important antimicrobial activity of the moringa oleifera leaf in inhibition of growth of staphylococcus aureus 32 mm, streptococcus spp. 30 mm which is more than inhibition zone caused by chlorohexidene gluconate 19 and 16 for the two bacteria respectively and enterococcus faecalis 11 mm that is less than inhibition zone of chlorohexidene gluconate14 mm. all the three type of bacteria gram positive. while gram negative bacteria (salmonella spp, escherichiacoli and klebsiella pneumonia) and fungi (candida albicans) exhibited resistance to the water extract of j bagh college dentistry vol. 28(1), march 2016 an antimicrobial basic sciences 185 moringaoleifera leave and have no any inhibition zone as in deionized water, on the other hand chlorhexidine gluconate have inhibition zone with different diameter on all these bacteria and fungi. de-ionized water considered as control negative in this study as showed in (table 1) and (figure 2). water extractsof moringa oleifera exhibit variable antibacterialactivity against bacteria; staphylococcus aureus showed higher inhibition zone 32 mm (figure 3) when use crude extract which is more than chlorhexidine gluconate followed by streptococcus spp as in (figure 3 and 4), and this inhibition zone proportionate with the concentration of the plant as the concentration of water extract of moringa oleifera increase from 20% to 100%, the inhibition zone increase gradually,as showed in (table 2) and (figures 5 and 6). table 1: the antimicrobial activity of the three agents bacteria and fungi aqueous extraction of moringa oleifera (stock solution 100%) chlorhexidine gluconate de-ionized water escherichia coli 0 16 mm 0 klebsiella pneumonia 0 13 mm 0 salmonella spp 0 13 mm 0 staphylococcus aureus 32 mm 19 mm 0 enterococcus faecalis 11 mm 14 mm 0 streptococcus spp 30 mm 16 mm 0 candida albicans 0 12 mm 0 figure 2: antimicrobial effect of three agents on different strain of microorganism the red is chlorhexidine, blue color is moringa oleifera and yellow color is de-ionized water. figure 3: crude extract of moringa oleifera and chlorhexidine gluconate on staphylococcus aureus. figure 4: crude extract of moringa oleifera and chlorhexidine gluconate on streptococcus spp. j bagh college dentistry vol. 28(1), march 2016 an antimicrobial basic sciences 186 table 2: inhibition zones of different concentration of moringa oleifera on staphylococcus aureus different concentration of moringa oleifera inhibition zones in mm on staphylococcus aureus inhibition zones in mm on streptococcus spp. 100 % 32 mm 30 mm 80 % 30 mm 28 mm 60 % 29 mm 22 mm 40 % 27 mm 19 mm 20 % 21 mm 15 mm a b figure 5: inhibition zones of different concentrations of moringa oleifera (20%, 40%, 60%, 80%and 100%) on staphylococcus aureus and streptococcus spp. figure 6: inhibition zones of different concentrations of moringa oleifera (20%, 40%, 60%, and 80%) on staphylococcus aureus. discussion the antibacterial activity of the aqueous extract of leaves of the plant moringa oleiferawas assayed in vitro by agar well diffusion method against six potentially pathogenic bacterial species with only one fungal species : three gram positive bacteria which are staphylococcus aureus, enterococcus faecaliand streptococcus spp. three grams negative which are escherichia coli, klebsiella pneumonia and salmonella spp. the only fungal species is candida albicans. all these microorganism have a causative role in the pathogenesis of many oral diseases and other diseases this agreed with kakehashi et al.,(17). gomes et al., show that the facultative microorganisms such as enterococcusfaecalis, staphylococcus aureus, etc., which are considered by many to be the most resistant species in the oral cavity (18). numerous researchers stated that moringa oleifera leave have antimicrobial action of water extract against multiple pathogens, several of them agree with the result of this study but some had slight different as a result of difference in genes of bacteria that make bacteria to be resistance to antimicrobial activity. similarly to priya et al., who evaluated the antibacterial activity of the aqueous leaf extracts j bagh college dentistry vol. 28(1), march 2016 an antimicrobial basic sciences 187 of moringa oleifera on pathogenic strain of bacteria like staphylococcus aureus, escherichia coli, klebsiellapneumoniae, and shigella spp. (19). the causes for the different may retain to concentration of the plant moringa oleifera or which part from the plant used or may be due to difference in bacterial species. thilza et al assessed the antimicrobial action of moringa oleifera leave extract on staphylococcus aureus, escherichia coli, pseudomonasaeruginosa and staphylococcus albus, and they discovered that only escherichia coli among tested bacteria exhibited inhibition zone (20). while vinoth et al., examined moringa leave water extract for antibacterial action, staphylococcus aureus only from tested bacteria exhibited sensitivity while no activity was recognized for escherichia coli, salmonella spp. andklebsiella, pneumonia (21). these results coincide completely with results of this study. this study revealed also that the chlorhexidene gluconate more effective against most of the pathogenic microorganisms except for the staphylococcus aureus and streptococcus spp. in which chlorhexidine gluconate less effective. this agrees with kanazwa and ueda, 2004 who suggested that chlorhexidine is important antiseptic agent or disinfectant for clinical isolates of various bacterial pathogens (22), while no activity was found with deionized water for any microorganism. as a conclusion; conflict additional increase of antibiotic resistant pathogens. it may be concluded from this study that the water extract of moringa oleifera is active against the tested gram positive bacteria especially staphylococcus aureus, the results confirm the use of the plant moringa oleifera showed promising antibacterial activities and it can play a role in the therapy of infection diseases.further in vivo studies and other studies are essential to verify its efficacy in clinical practice. references 1. fahey sd. moringa oleifera: a review of the medical evidence for its nutritional, therapeutic and prophylactic properties, part1. http://www.tfl journal.org 2005; 1(5):1 15. 2. nouman w, basra sma, siddiqui mt, yasmeen a, gull t, et al. potential of moringa oleifera l. as livestock fodder crop: a review. turk j agric for 2014; 38: 1–14. 3. diallo d, hveem b, mahmoud ma, betge g, paulsen bs, maiga a. an ethnobotanical survey of herbal drugs of gourma district. mali pharmaceutical biol 1999; 37: 80–91. 4. chumark p, khunawat p, sanvarinda y, phornchirasilp s, morales pn, phivthong-ngam, et al. the in vitro and ex vivo antioxidant properties, hypolipidaemic and antiatherosclerotic activities of the water extract of moringa oleifera lam leaves. j ethnopharmacol 2008;116: 439-46. 5. dahiru d, obnubiyi ja, umaru ha. phytochemical screening and antiulcerogenic effect of moringa. african journal of traditional, complimentary and alternatives medicines 2006; 3: 70-5. 6. danmalam hu, abubakar z, katsayal ua. pharmacognostic studies on the leaves of moringa oleifera. nigerian j natural product and medicine 2001; 5: 45-9. 7. mahmood k, mugal t, haq iu. moringa oleifera: a natural gift-a review. j pharm sci res 2010; 2: 775– 81. 8. moringa/moringa oleifera. available online: http: //www. infonetbiovision.org/ default/ct/758/ agroforestry (accessed on 16 april 2015). 9. dametto fr, ferraz cc, gomes bp zaia aa, teixeira fb, souza-filho fj. oral surg oral med oral pathol oral radiol endod 2005; 99, 768-72. 10. mistry ks, sanghvi z, parmar g, shah s. the antimicrobial activity of azadirachta indica, mimusops elengi, tinospora cordifolia, ocimum sanctum and 2% chlorhexidine gluconate on common endodontic pathogens: an in vitro study. eur j dent 2014; 8(2): 172-7. 11. johnson c. clinical perspectives on the health effects of moringa oleifera: a promising adjunct for balance nutritionand better health. la canada, ca, kos health publications. 2005; 1-5p.910−911. 12. monica hk, sharma bc, singh c. kinetics of drumstick leaves (moringa oleifera) during convective drying, african j plant science 2010; 4(10): 391-400. 13. pal sk, mukherjee pk, saha bp. studies on the antiulcer activity of m. oleifera leaf extract on gastric ulcer models in rats. phytother res 1995; 9: 463-5. 14. cheesbrough m. district laboratory practice manual in tropical countries part 2. cambridge: cambridge university press; 2000; 136-137. 158,165,180. 15. bauer aw, kibry wm, sherris jc, turck m. antibiotic susceptibility testing by a standardized single disc method. am j clinpathol 1966; 45: 493 6. 16. perez c, anesini c, ethnopharmacol j 1993; 44: 41-6. 17. kakehashi s, stanley hr, fitzgerald rj. oral surg oral med oral pathol 1965; 20: 340-9. 18. gomes bpfa, drucker db, lilley jd. int endod j 1996; 29: 69-75. 19. priya vp, abiramasundari s, gayathri d, jeyanthi gp. antibacterial activity of the leaves, bark, seed and flesh of moringa oleifera. 2011; 2(8): 20459. 20. thilza ib, sanni s, adamuisah z, sanni fs, talle m, joseph mb. in vitro antimicrobial activity of water extract of moringa oleifera leaf stalk on bacteria normally implicated in eye diseases nigeria academia arena 2010; 2(6): 80-2. 21. vinoth b, manivasagaperumal r, balamurugan s. phytochemical analysis and antibacterial activity of moringa oleifera lam, india. international j res biological sci 2012; 2(3): 98-102. 22. kanazwa k and ueda y. bactericidal activity of chlorhexidine gluconate against recent clinical isolates of various bacterial species in japan. jpn j antibiot 2004; 57(5): 449-64. http://www.tfl abbas f.doc j bagh college dentistry vol. 25(4), december 2013 evaluation of the stress restorative dentistry 1 evaluation of the stress concentration of different incisal ridge preparations of porcelain veneers (finite element analysis) abbas f. al-huwaizi, b.d.s., m.sc., ph.d. (1) abstract background: porcelain veneers are under a great deal of stress which may lead to clinical failure as fracture or dettachment. this study examined whether different finishing lines and lingual shoulder preparations in the incisal area of the maxillary central incisor affect the bond of the porcelain veneers. materials and methods: a twodimensional finite element model was made. location and magnitude of maximum von mises stresses were calculated in porcelain veneer. six types of preparations were drawn as:incisal overlap of 0.5mm, 1mm and 1.5mm depth and lingual shoulder, and incisal overlap of 0.5mm, 1mm and 1.5mm depth without shoulder preparation. results: stress formation is maximum in the incisal edge region. all the lingual shoulder preparations presented better stress distribution than the non shoulder preparations conclusion: stress is distributed more evenly when the tested preparation possesses a good thickness of porcelain and the more the surface area with incisal overlap the less possibility of bond failure. key words: porcelain veneer, stress distribution, finishing line. (j bagh coll dentistry 2013; 25(4):1-4). introduction porcelain veneers may be used for many treatment modalities as for treating discoloured teeth or teeth with minor loss of the incisal edge. (1, 2) the success rate of porcelain veneers was clinically ranges from 75-100% (3-7) . factors affecting long term success of porcelain veneers are age, gender of the patient and fabrication techniques (6) . therefore, failure in porcelain veneers seems to be associated with changes in bonding condition and / or the magnitude of incisal load (8) . the most recent adhesive techniques have given high bonding strength, therefore improving bond of the porcelain veneer efficiently to the tooth structure. the marginal design of the finishing line was studied to verify the stress concentration by the use of 2 dimensional finite element analysis (9, 10) , but none clearly emphasized on the effect of incisal porcelain thickness and lingual shoulder preparation on stress distribution the purpose of this study was to examine the distribution of stresses in porcelain veneers in different incisal preparations with and without lingual shoulder preparation. materials and methods the finite analysis was conducted using the ansys 5.4 finite element package (swanson analysis system, housten, pennsylvania). (1)assist. professor, college of dentistry, university of kufa two dimensional finite element models of porcelain veneers on teeth with intermediate layers of bonding agent, and composite resin were designed according to the size of an average maxillary central incisor. the abutment was considered to be homogenous. the dimensions of the preparation for the porcelain veneers were drawn according to rufenacht in1992, where 0.3 mm was prepared cervically, 0.5 mm in the middle and 0.7 mm incisally. the porcelain veneer preparation was all within enamel. three types of finishing lines incisally were drawn to create models and as follows: group i: incisal overlap 0.5 mm and lingual shoulder group ii: incisal overlap 1 mmand lingual shoulder group iii: incisal overlap 1.5 mm and lingual shoulder group iv: incisal overlap 0.5 mm. group v: incisal overlap 1 mm. group vi: incisal overlap 1.5 mm the composite resin was drawn to be 100 um thick (11) and the bonding agent was 1 um thick. (8) the model was divided into 5 main areas representing porcelain laminate, composite cement layer, enamel bonding layer, enamel and dentine, while the pulp was assumed as a nul element. the properties for the material used in the study are listed in table 1. the load of 50 n at 60o labiocervically was applied at lingual slope of incisal edge. ten areas were evaluated for stress concentration along the j bagh college dentistry vol. 25(4), december 2013 evaluation of the stress restorative dentistry 2 interface between the veneer and the tooth structure (figure 1). table 1: materials’ properties.(8) material esthetic modulus (gpa) poisson’s ratio porcelain 70 0.19 composite cement 6 0.4 resin 5 0.4 enamel 84 0.33 dentin 19 0.31 results table 2 and figures 1-8 present the stress distribution picture along the porcelain veneer– tooth interface. different stress concentrations are seen in the different points evaluated and are as follows: point 1: the incisal reduction with lingual shoulder preparations were comparable (0.2, 2 and 2) but preparations without shoulder showed more and unequal degrees of stress distribution (8,8 and 2mpa) point 2, 6 and 7: the more incisal reduction with lingual shoulder preparations the less stress accumulation and the same picture was seen in preparations without shoulder but with higher stress values. table 2: distribution of stress in different points of the porcelain veneer preparation 1 2 3 4 5 6 7 8 9 10 incisal overlap 0.5 mm+ling. shoulder 0.2 20 135 217 211 139 121 120 95 118 incisal overlap 1 mm+ling. shoulder 2 20 94 217 185 115 94 70 73 95 incisal overlap 1.5mm+ling. shoulder 2 11 51 190 204 93 61 51 54 53 incisal overlap 0.5 mm 8 31 140 217 214 204 170 137 121 125 incisal overlap 1 mm 8 24 89 216 214 125 101 95 55 92 incisal overlap 1.5 mm 2 7 45 217 199 95 56 51 51 53 point 4: very high and comparable stress values were found in all the preparations except 1.5 mm incisal reduction with lingual shoulder preparation which was less (190 mpa compared with 217 mpa). point 5: very high and comparable stress values were found in all the preparations except in 1 mmand 1.5 mm incisal reduction with lingual shoulder preparationand 1.5 mm incisal reduction with shoulder which was less (185-204 mpa compared with 214 mpa). by dividing the porcelain veneer to 3 segments, it is evident that the labial segment (points 1, 2 and 3) show the least stress concentration (maximum 8, 31 and 140 mpa respectively). the incisal segment (points 4 and 5) presented the highest stress concentration (maximum 217 and 214 mpa respectively). the lingual segment (points 6-10) presented another stress concentration picture (maximum 204, 170, 137, 121 and 125 mpa). points 3,8, 9 and 10: the more incisal reduction with lingual shoulder preparations the less stress accumulation and the same picture was seen in preparations without shoulder but with comparable stress values. figure 1: schematic diagram of the spots studied for stress distribution figure 2: incisal overlap 0.5 mm+ lingual shoulder 1 2 3 4 5 6 7 8 9 10 j bagh college dentistry vol. 25(4), december 2013 evaluation of the stress restorative dentistry 3 figure 3: incisal overlap 1 mm+ lingual shoulder figure 4: incisal overlap 1.5 mm+ lingual shoulder figure 5: incisal overlap 0.5 mm+ lingual without shoulder figure 6: incisal overlap 1mm+ lingual without shoulder figure 7: incisal overlap 1.5 mm+ lingual without shoulder discussion the use of veneers to replace enamel during rehabilitations is recommended.(12) regarding point 1,lingual shoulder preparations produced more wrap around the incisal ridge surface area which decreased the dislodging force on point 1 (the middle of the labial wall). the stress distribution picture of points 2,6 and 7 are comparable and show that the surface area of lingual shoulder is directly related to better stress distribution. this is in compliance with the results of magne and douglas (1999) (10) preparations with lingual shoulder and shallow incisal overlap (0.5 and 1 mm)have less surface area and wrap around incisal ridge therefore higher stress is seen. points 3,8,9 and 10 shared the same stress distribution. the thickness of the porcelain distributes the force . the force is at 90 degrees with the wall of the incisal porcelain which makes these points under compression and little value of the wraparound the incisal ridge. this agrees with the result of sorrentino et al. (2009) who stated that compressive stresses were concentrated on the external surface of the buccal side of the veneer close to the incisal margin. (13) point 4 is the touching point with the force with maximum stress concentration reaching 217 mpa which comparable with the results of chander and padmanabhan(2009) (14). in this point, the 1.5mm incisal reduction with lingual shoulder preparation has the least stress concentration because it has the most thickness of porcelain therefore stress is distributed more evenly in the porcelain. the stress concentration in point 5 showed that the more thickness of the porcelain and surface area distributes the stress. from the segmental picture of the stress concentration of porcelain veneers, it is evident that the lingual area needs reinforcement because it is under considerable stress (12) references 1christensen gj. the state of the art in esthetic restorative dentistry. j am dent assoc 1997; 128: 1315-7 2calamia jr. the current status of etched porcelain veneer restorations. j phlipp dent assoc 1996; 47: 3541. 3christensen gj, christensen rp. clinical observations of porcelain veneers: a three year report. j esthet dent 1991; 3: 174-9. 4nordbo h, rygh-thoresen n, henaug t. clinical performance of porcelain laminate veneers without incisal overlapping: 3year results. j dent 1994; 22: 342-5. 5denissen hw, wijnhoff gf, veldhuis aa, kalk w. five-year study of all-porcelain veneer fixed partial dentures. j prosthet dent 1993; 69: 464-8. j bagh college dentistry vol. 25(4), december 2013 evaluation of the stress restorative dentistry 4 6dunne sm, millar bj. a longitudinal study of the clinical performance of porcelain veneers. br dent j 1993; 175: 31721. 7garber d. porcelain laminate veneers: ten years later. part i: tooth preparation. j esthet dent 1993; 5: 56-62. 8troedson m, derand t. effect of margin design, cement polymerization, and angle of loading on stress in porcelain veneers. j prosthet dent 1999; 82: 51824. 9magne p, douglas wh. optimization of resilience and stress distribution in porcelain veneers for the vol. 17(2) 2005 a finite element analysistreatment of crown-fractured incisors. int j perio rest dent 1999; 19(6): 543-53. 10magne p, douglas wh. design optimization and evolution of bonded ceramics for the anterior dentition: a finite-element analysis. quintessence int 1999; 30(10): 661-72. 11rufenacht cr. fundementals of esthetics. 1st ed. quintessence books; 1992. p. 335. 12matson mr, lewgoy hr, barros filho da, amore r, anido-anido a, alonso rc, carrilho mr, anauatenetto c. finite element analysis of stress distribution in intact and porcelain veneer restored teeth. comput methods biomech biomed engin 2012; 15(8):795800. 13sorrentino r, apicella d, riccio c, gherlone e, zarone f, aversa r, garcia-godoy f, ferrari m, apicella a.nonlinear visco-elastic finite element analysis of different porcelain veneers configuration. j biomed mater res b appl biomater 2009; 91(2):72736. 14chander ng, padmanabhan tv. finite element stress analysis of diastema closure with ceramic laminate veneers. j prosthodont 2009; 18(7):577-81. points of stress distributio n 1 2 3 4 5 points of stress distributio n 6 7 8 9 10 figure 8: distribution of stress in different points of the porcelain veneer preparation aseel f.doc j bagh college dentistry vol. 25(3), september 2013 caries experience pedodontics, orthodontics and preventive dentistry130 caries experience and salivary physicochemical characteristics among overweight intermediate school females aged 13-15 years in babylon – iraq aseel i. mohammed, b.d.s. (1) ban s. diab, b.d.s., m.sc., ph.d. (2) abstract background: obesity is a serious public health concern that has reached epidemic proportions; the prevalence, as well as the severity of obesity in adolescents is increasing at an alarming rate. a close relationship was found between weight status and dental caries. thus this research aimed to assess the prevalence and severity of dental caries among overweight adolescent females in relation to physicochemical characteristics of stimulated whole saliva in comparison with normal weight adolescent females. materials and methods: the total sample involved for nutritional status assessment is composed of 2678 females aged 13-15 years. this was performed using body mass index specific for age and gender according to cdc growth chart (2000). the diagnosis and recording of dental caries was by using decay, missing, filled surface index (dmfs); and according to the criteria of manji et al (1989). salivary samples were collected from 30 overweight females and their control under standardized conditions and then analyzed for measuring salivary flow rate and viscosity, in addition to estimation essential elements (zinc, copper, calcium, iron, and total protein). results: the caries experience among the overweight females was lower than that among the normal weight with non significant difference. salivary analysis demonstrated that the salivary flow rate was non significantly higher among overweight females. the viscosity of saliva was having an equal value among both groups. the data analysis of salivary elements found that the zinc and copper concentrations were highly significant higher among the overweight females than that among the normal weight. the opposite result found concerning salivary calcium level with also highly significant difference; while the iron and total protein were non significantly lower among the overweight females. dmfs and its grades correlated negatively weak with salivary flow rate among overweight females; while concerning salivary viscosity, the correlation was direct weak with dmfs. salivary copper, calcium and total protein showed an inverse correlation with dental caries. conclusion: the results of the current research revealed that overweight affect the caries experience. several of salivary factors that found to be higher among the overweight females might play a role in protection of teeth from dental caries. key words: overweight, adolescents, dental caries. (j bagh coll dentistry 2013; 25(3):130-133). introduction obesity or overweight is a complex, multifactorial disease that develops from the interaction between genotype and the environment (1). a form of low grade, systemic inflammation is linked to many types of chronic disease which associated with obesity (2, 3). dental caries and obesity epidemics are multifactorial complex diseases and the dietary pattern is a common underlying etiologic factor in their causation (4). the term dental caries is used to describe the signs and symptoms of a localized chemical dissolution of the tooth surface caused by metabolic events taking place in the biofilm (dental plaque) covering the affected area; and the destruction can affect enamel, dentin and cementum (5). researches which studied the relation between dental caries and overweight found a controversy (6-8). saliva can be useful method in the evaluation of caries risk as well as in the diagnosis of other diseases (9); as, optimum salivary flow rate is responsible for establishing (1) master student, department of paedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of paedodontics and preventive dentistry, college of dentistry, university of baghdad. protective environment against dental caries (10). moreover, salivary composition also have essential role in dental caries occurrence (11-13). the global steady increase in the prevalence of adolescents overweight leads to inclination to know the prevalence of adolescent overweight in iraq, in relation to oral health status and physicochemical properties of saliva; these reasons guided to designing this research. materials and methods the sample size composed of 2678 females; they were distributed in secondary schools of hilla center which randomly selected from different areas and represented 5% of the number of intermediate schools of hilla center. the whole females aged 13-15 year old attending the selected secondary schools were examined for nutritional status assessment (bmi); then the overweight females and their age matching females from the same class were examined for the oral health status assessment. then subgroups of 30 females from both overweight and normal weight groups were randomly selected for salivary analysis. the caries experience was recorded according to decay, missing, filled index (dmfs); and by using j bagh college dentistry vol. 25(3), september 2013 caries experience pedodontics, orthodontics and preventive dentistry131 the criteria of manjie et al. (14) which allow recording decayed lesion by severity. the collection of stimulated salivary samples was performed under standard condition following instruction cited by tenovuo and lagerlof (15). the salivary flow rate was measured as milliliter per minute (ml / min); while viscosity was assessed by using ostwald's viscometer (16). target salivary elements were zinc, copper, calcium, iron and total protein which analyzed at the poisoning consultation center / specialized surgeries hospital. salivary zinc, copper and calcium were analyzed by flame atomic using spectrophotometer flame atomic, using absorption spectrophotometer (buck scientific, 210vgp, usa) following standardized procedure. the method used to determine the level of salivary iron and total protein by colometric method with using of special kits according to the manufactured instructions. data analysis was conducted by application of spss program (version 18). results the prevalence of overweight in the present study was found to be 4.89% as only 129 females were found to be overweight. data of present study showed that for the total sample the mean dmfs for the overweight females (9.40 ±5.90) was lower than that of the normal weight female (10.11±5.98), but the difference was not significant. moreover, the same result was found concerning dmfs components and ds grades as shown in tables 1 and 2. table 3 shows the physicochemical characteristics of saliva among overweight and normal weight females. in this table reveals that salivary flow rate among the overweight females in current study was higher than that among the normal weight with non significant difference. it was also found that the salivary viscosity had equal value among both groups of females. the concentrations of salivary copper and zinc in current study were highly significant higher among overweight females than normal weight (t=12.00, 6.48, p< 0.01); and concerning the calcium level, the opposite result found, as it was highly significant higher among normal weight than overweight females (t= -5.56, p<0.01). in addition to that, iron and total protein concentrations in saliva in this study were non significantly lower among overweight females. table 4 reveals the correlations between dmfs and salivary physicochemical characteristics; in this table the flow rate was correlated in a negative direction and non significant, while salivary viscosity and dmfs were positively correlated among the overweight females. concerning the correlations of saliva's constituents with dmfs; they were in a positive direction with zinc and iron, but in a negative direction with copper, calcium and total protein. discussion the prevalence and the experience of dental caries among the overweight females in the current study were nonsignificantly higher than that among the normal weight females; this goes in accordance with previous studies (8,17) and in non accordance with other studies (18, 19). the low caries prevalence among overweight females in this study could be attributed to type of diet, as that rolland-cachera et al. (20) showed that overweight is associated with high dietary fat intake. on other hand, fat in foods was associated with inhibition of both sulcal and buccolingual (smooth-surface) caries (21); one can explain that from the result of bowen's study (22), which found that presence of fat in experimental diets has been shown to affect their cariogenicity, and its effects have been ascribed to enhanced clearance of sugars from the mouth and also several fatty acids express a potent antibacterial effect. other cause could be the salivary flow rate; data analysis of the present study showed that the salivary flow rate among the overweight females was higher than that among the normal weight with non significant difference between them. moreover, the correlation between the salivary flow rate and dental caries in the present research showed an inverse relation among the overweight females; and this result was also in agreement with previous studies (8, 23). this could be attributed to that higher the flow rate, faster the clearance, higher the buffer capacity (24, 25). additionally, another explanation could be that highly significant levels of salivary zinc and copper among the overweight; and the correlation between the salivary zinc and dental caries among the overweight females revealed a significant positive correlation concerning d1, and a negative non significant relation concerning d4 which in agreement with al-saddi (8). this may be explained by study of lippert (26) which found that zinc enhanced remineralization and exhibited detrimental effects on remineralization in a doseresponse manner, also zinc showed extensive remineralization of deeper parts within the lesions at the expense of remineralization near the surface. on other hand, the copper concentration in saliva in present study showed an inverse correlation between salivary copper and dental caries among the overweight females; this may be related to its effect in suppression of biofilm growth (11). j bagh college dentistry vol. 25(3), september 2013 caries experience pedodontics, orthodontics and preventive dentistry132 so, one can expected that these high levels of salivary zinc and copper could be one of reasons for low dental caries, as these two elements are considered important elements in the healthy teeth (27-29). table 1. caries experience (dmfs) and its components among the overweight and normal weight females dmfs components overweight normal weight tvalue sig. no. mean ± sd ± se no. mean ± sd ± se ds 129 8.88 5.67 0.5 129 9.46 5.98 0.49 -0.82 0.41 ms 129 0.35 1.42 0.13 129 0.47 1.71 0.15 -0.6 0.55 fs 129 0.17 0.64 0.06 129 0.23 1.1 0.1 -0.55 0.58 dmfs 129 9.4 5.9 0.52 129 10.11 5.98 0.53 -0.95 0.34 *d.f= 256 table 2. grades of ds (d1, d2, d3, and d4) among the overweight and normal weight females *d.f= 256 table 3. the physicochemical characteristics among overweight and normal weight females parameters overweight normal weight tvalue sig. no. mean ± sd ± se no. mean ± sd ± se sfr* 30 0.57 0.26 0.05 30 0.55 0.25 0.05 0.33 0.74 viscosity 30 0.02 0.01 0.00 30 0.02 0.01 0.00 0.41 0.68 copper 30 4.18 0.51 0.09 30 2.65 0.49 0.09 12.00** 0.00 zinc 30 5.91 0.81 0.15 30 4.70 0.62 0.11 6.48** 0.00 calcium 30 1.47 0.97 0.18 30 3.04 1.20 0.22 -5.56** 0.00 iron 30 32.05 7.89 1.44 30 34.40 9.69 1.77 -1.03 0.31 total protein 30 0.40 0.09 0.02 30 0.43 0.06 0.01 -1.47 0.15 *salivary flow rate, **highly significant, # d.f= 58 table 4. correlation coefficient between the salivary physicochemical characteristics and caries experience (ds and dmfs) parameters ds dmfs overweight normal weight overweight normal weight r p r p r p r p sfr* -0.35 0.06 -0.05 0.79 -0.33 0.07 -0.06 0.76 viscosity -0.03 0.86 -0.31 0.09 0.07 0.71 -0.28 0.13 copper -0.24 0.20 0.08 0.66 -0.23 0.23 0.15 0.43 zinc 0.36 0.05 -0.07 0.70 0.43** 0.02 -0.17 0.37 calcium -0.09 0.63 0.44** 0.02 -0.06 0.76 0.44** 0.02 iron 0.10 0.61 -0.14 0.47 0.08 0.69 -0.18 0.34 total protein -0.07 0.73 0.25 0.18 -0.02 0.93 0.23 0.23 *salivary flow rate, ** significant (p<0.05). references 1. nih (national institutes of health), national heart, lung, and blood institute, north american association for the study of obesity. the practical guide: identification, evaluation, and treatment of overweight and obesity in adults. 2000. 2. egger g, dixon j. non nutrient causes of low grade, systemic inflammation: support for a ‘canary in the mineshaft’ view of obesity in chronic disease. obesity reviews 2011; 12(5): 339-45. 3. tam c, clement k, baur l.a, tordjman j. obesity and low-grade inflammation: a paediatric perspective. obesity reviews 2010; 11(2):118-26. ds grades overweight normal weight tvalue sig. no. mean ± sd ± se no. mean ± sd ± se d1 129 7.36 5.38 0.48 129 7.38 4.99 0.44 -0.02 0.98 d2 129 0.91 1.14 0.10 129 1.02 1.36 0.12 -0.75 0.46 d3 129 0.29 0.95 0.08 129 0.39 1.12 0.10 -0.72 0.47 d4 129 0.32 1.46 0.13 129 0.67 1.72 0.15 -1.76 0.08 j bagh college dentistry vol. 25(3), september 2013 caries experience pedodontics, orthodontics and preventive dentistry133 4. hedge am, sharma a. genetic sensitivity to 6-npropylthiouracil (prop) as a screening tool for obesity and dental caries in children. j clin pediatr dent 2008; 33(2):107-11. 5. fejerskov o. kidd e. nyvad b. baelum v. defining the disease: an introduction. in: fejerskov o. kidd e, (eds). dental caries: the disease and its clinical management. 2nd ed. blackwell munksgaard ltd.; 2008. 6. mojarad f, maybodi m. association between dental caries and body mass index among hamedan elementary school children in 2009. j dent (tehran) 2011; 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21(2): 92-101. 13. alves km, franco ks, sassaki kt, buzalaf ma, delbem ac. effect of iron on enamel demineralization and remineralization in vitro. arch oral biol 2011; 56(11):1192-8. 14. manji f, fejerkov o, baelum v. pattern of dental caries in an adult rural population. caries res 1989; 23: 55-62. 15. tenovou j, legerlof f. saliva in: thylstup a, fejerskov o (eds). text book of clinical cariology, 2nded. copenhagen: munksgaard; 1994: 17-43. 16. shridhar r gadre. century of noble prizes: 1909 chemistry laureate wilhelm ostwald (1853-1932). resonance 2003; 77-83. 17. köksal e, tekçiçek m, yalçin ss, tuğrul b, yalçin s, pekcan g.association between anthropometric measurements and dental caries in turkish school children. cent eur j public health 2011; 19(3):147-51. 18. alm a, isaksson h, fåhraeus c, koch g, anderssongäre b, nilsson m, birkhed d, wendts lk. bmi status in swedish children and young adults in relation to caries prevalence. swed dent j 2011; 35(1):1-8. 19. honne t, pentapati k, kumar n, acharya s. relationship between obesity/overweight status, sugar consumption and dental caries among adolescents in south india. int j dent hyg 2011: 14. 20. rolland-cachera mf, maillot m, deheeger m, souberbielle jc, péneau s, hercberg s. association of nutrition in early life with body fat and serum leptin at adult age. int j obes (lond). 2012 21. mundorff-shrestha sa, featherstone jd, eisenberg ad, cowles e, curzon me, espeland ma, shields cp. cariogenic potential of foods. ii. relationship of food composition, plaque microbial counts, and salivary parameters to caries in the rat model. caries res 1994; 28(2):106-15. 22. bowen wh. food components and caries. adv dent res 1994; 8(2): 215-20. 23. al-jorrani s. concentration of selected elements in permanent teeth, enamel and saliva among a group of adolescent girls in relation to severity of caries and selected salivary parameters. master thesis, college of dentistry, university of baghdad, 2012. 24. lenander-lumikari m, loimaranta v. saliva and dental caries. adv dent res 2000; 14: 40-7. 25. katie p, jyh-yuh k, chia-ying c, chia-ling c, tsong-long h, ming-yen c, alice w, ching-fang h, yu-cheng l. relationship between unstimulated salivary flow rate and saliva composition of healthy children in taiwan. chang gung med j 2008; 31: 281-6. 26. lippert f. dose-response effects of zinc and fluoride on caries lesion remineralization. caries res. 2012; 46(1): 62-8. 27. elsamurria sk. major and trace elements contents of permanent teeth and saliva among a group of adolescents in relation to dental caries, gingivitis and mutans streptococci. ph.d. thesis, college of dentistry, university of baghdad, 2001. 28. foley j, blackwell a. in vivo cariostatic effect of black copper cement on carious dentine caries res 2003; 37(4): 254-60. 29. aydin sevinç b, hanley l. antibacterial activity of dental composites containing zinc oxide nanoparticles. j biomed mater res b appl biomater 2010; 94(1): 22-31. hiba f.doc j bagh college dentistry vol. 25(4), december 2013 digital panoramic oral diagnosis 44 digital panoramic estimation of chronological age among iraqi adult population in relation to morphological variables of canine teeth hiba abdulredha habeeb, b.d.s. (1) ahlam a. fattah, b.d.s, m.sc. (2) abstract background: age determination of skeletal remains is apart of many medico-legal as well as anthropological examination. many anatomical structures have been studied, but the teeth and their measurements seem to be the most reliable method since teeth represent the most durable and resilient part of the skeleton. this study was undertaken for estimating the chronological age among iraqi adult subjects based on various morphological variables of canine teeth using digital panoramic radiograph. material and methods: the sample in the current study consisted of 240 iraqi patients attending to the dental radiological clinic at college of dentistry/ babylon university taking panoramic radiographs for different diagnostic purposes, the study sample included both sexes with age ranged 20-60 years old, the following measurements of maxillary right canine have been taken with the aid of computer program (2008): maximum tooth length, root length measured from midpoint of cemento-enamel junction to the root apex, pulp length, root width at cemento-enamel junction, root width at mid-root level, root width at mid-point between cemento-enamel junction and mid-root level, pulp width at cemento-enamel junction, pulp width at mid-root level, pulp width at mid-point between cementoenamel junction and mid-root level, tooth area, pulp area. the data were subjected to statistical analysis using statistical package for social sciences version 13. results: the result of the current study showed that from the various parameters measured, the differences between real age and estimated age of subjects were not statistically significant except for root length and pulp area which show significant difference between real age and estimated age with p-value 0.004 and 0.002 respectively. conclusion: age of the subjects can be estimated using regression equations including root length and pulp area for the examined tooth. keywords: forensic dentistry, age estimation by canine teeth, orthopantomography. (j bagh coll dentistry 2013; 25(4):44-48). : الخالصة ھا تعتبر األكثر كل العظمي یعتبر جزء من فحوصات الطب الشرعي وكذلك األنثروبولوجیھ ولقد تم دراسة العدید من الھیاكل التشریحیة ولكن األسنان وقیاساتتحدید العمرمن بقایا الھی . كجزء من الھیكل العظمي" موثوقیة ومرونة واألكثر دواما نھ من السكان العراقیین البالغین وذلك باألعتماد على مختلف المتغیرات الشكلیة لألنیاب باستخدام االشعھ البانورامیة أجریت ھذه الدراسة لتقدیر العمر الزمني لعی :الھدف من الدراسة . الرقمیة خذ صورة بانورامیة ألغراض جامعة بابل أل/ مریضا عراقیا حضروا الى العیادة األشعاعیة في كلیة طب األسنان 240العینة في الدراسة الحالیة تتألف من :المواد وطرائق العمل : من كل صورة بانورامیة اخذت القیاسات التالیة من ناب الفك العلوي األیمن بمساعدة برنامج حاسوب یدعى التصمیم الھندسي, سنة 6020مختلفة من كال الجنسین وبعمر یتراوح من ، عرض الجذر في مستوى منتصف الجذر، عرض الجذر cejجذر، وطول اللب ، عرض الجذر في إلى قمة ال) cej(الحد األقصى لطول األسنان، طول الجذر یقاس من منتصف ال و مستوى منتصف cej، عرض اللب في مستوى منتصف الجذر، عرض اللب في منتصف نقطة بین cejومستوى منتصف الجذر، عرض اللب في cejفي منتصف نقطة بین . .spss.version13)(یانات للتحلیل التمییزي بأستخدام برنامج احصائي واستخدمت الب. الجذر، مساحة السن، ومساحة اللب عدم وجود اختالف احصائي بین العمر الحقیقي والعمر المقدر بأستثناء طول الجذر ومنطقة اللب التي تظھر , أظھرت نتائج الدراسة الحالیة من مختلف المتغیرات التي قیست :النتائج . الجنس لیس لھ تأثیر احصائي على تقدیر العمر. على التوالي 0.002و v 0.004عمر الحقیقي والعمر المقدر مع قیمة اختالف احصائي كبیر بین ال . یمكن تقدیر العمر بأستخدام معادالت األنحدار المتضمنھ طول الجذر ومساحة اللب للسن المقاس :األستنتاجات .االشعھ البانورامیھ الرقمیة, من اسنان االنیابتحدید العمر , طب االسنان القضائي: مفاتیح البحث introduction forensic odontology is a relatively new science that utilizes the dentist’s knowledge to serve the judicial system. worldwide, dentists qualified in forensic science are giving expert opinion in cases related to human identification, bite mark analysis, craniofacial trauma and malpractice. human identification relies heavily on the quality of dental records; however forensic odontologists can still contribute to the identity investigation in the absence of dental records through profiling the deceased person using features related to teeth (1). (1) m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. it is often necessary to estimate an individual's age due to certain questions related to legal requirements in paleodemographic research or in a forensic context. although several parts of the body can be used for age estimation, the poor condition of the remains in particularly severe crashes or fires in cases of those recently dead; or of moisture and burial conditions in the case of historic subjects, make many parts of the body unusable. for these reasons, teeth are the part of the body most frequently used for identification and age estimation (4) in children, age determination from teeth is a relatively simple, accurate procedure and is based on the stages of development and eruption of j bagh college dentistry vol. 25(4), december 2013 digital panoramic oral diagnosis 45 teeth. however, in adults it is a challenge to medico-legal science (5). up to now, a multiplicity of methods have been applied to this problem, including methods which analyze the various forms of tooth modification such as wear, dentin transparency, tooth cementum annulations, racemization of aspartic acid and apposition of secondary dentin. canines were chosen to assess age and gender for a number of reasons: they have the longest functional survival rate in the mouth, undergo less wear as a result of diet than posterior teeth, are less likely than other anterior teeth to suffer wear as a result of particular work, and are the single-root teeth with the largest pulp area and thus the easiest to analyze (9). the study of tooth radiographs is a non destructive and simple process which can be applied to both living and deceased persons (10). panoramic radiography is a radiological technique for producing a single image of the facial structures. it is become a very popular in dentistry (15) in the present study digital panoramic radiography used for determination of age and gender in iraqi adults subjects. material and methods the study sample consisted of 274 subjects, 34 subject excluded because they were not fit to the criteria of inclusion designed for the current study. after clinical and radio-graphical examination 240 subjects (108 male and 132 female) of different age groups ranged 20-60 years selected in the study sample, the collected sample include patients attended for different diagnostic purposes to the dental radiology department at the college of dentistry, university of babylon. those subjects were divided according to the age range into four groups, criteria of inclusion fully erupted right maxillary canine; 1right maxillary canine free from any pathology such as caries, pathological lesion, periodontitis, abrasion, erosion or fracture. 2absence of restoration and endodontic filling of the right maxillary canine. 3 absence of mal-aligned or rotated right maxillary canine. digital panoramic radiograph of each patient was taken, using certain exposure factors for each gender (male and female) according to user manual. the images were examined on the monitor for the clear representation enhancement of the resolution was done if needed then saved, the images were entered as 1024*768 pixel digital images (jpeg files) in the computer system, and then imported to adobe photo-shop image editing software program (adobe system incorporated, san jose, (a,usa) (1990-2002). minimum of 20 points around the edge of tooth outline and minimum of 10 points around the pulp outline of the right maxillary canine were identified, then image were printed and tracing of these points by 0.5 pencil, in order to evaluate the measurements of the canine tooth area and the pulp area from the radiographic image(12), figure 1. next the images were imported to the auto cad program, it was appear in the master sheet on which the points were determined, and then measurements were obtained, after correction of magnification by multiplying the readings by the magnification factor which was obtained as a ratio between a real distance measurements for a scale and the distance measurements for the same scale from radiographic image, after that the measurements were saved on an excel sheet. the following measurements for the right maxillary canine were taken on the panoramic images: 1maximum tooth length. 2root length measured from midpoint of cemento-enamel junction (cej) to the root apex. 3pulp length. 4root width at cej. 5root width at mid-root level. 6root width at mid-point between cej and mid-root level. 7pulp width at cej. 8pulp width at mid-root level. 9pulp width at mid-point between cej and midroot level. 10tooth area. 11pulp area. statistical analysis was performed using spss v. 13(spss inc., chicago, usa). linear regression model for age estimation was developed by selecting those variables which contributed significantly to age estimation. student's ttest was used to compare the morphological variables of males with those of females and to compare observed age with estimated age. a p value ≤ 0.05 was considered statistically significant. results in the present study, 108 males and 132 females (total 240 subjects) were divided into four j bagh college dentistry vol. 25(4), december 2013 digital panoramic oral diagnosis 46 groups. the morphological variables did not show any significant difference between the sexes. table 1 shows the regression analysis in males, while table 2 shows the result in females and table 3 in the total study sample. in the total study sample only root length (0.004) and pulp area (0.002) showed significant difference between real age and estimated age, which yielded the following linear regression formula to estimate chronological age: estimated chronological age =18.73 + 2.55 (root length) 0.92 (pulp area). there was no significant difference between observed and estimated age for any of the age groups (table 4). also there was no significant difference between observed and estimated age for either males or females (table 5). figure 1: panoramic radiographic image showing points on tooth and pulp outline. table 1: regression analysis for all morphological variables (predictors) and age as the dependent variable in males (n = 108) model regression coefficients s.e. significant level t-test p-value constant 27.31 18.34 1.49 0.140 (ns) tooth length -1.57 1.46 -1.08 0.285 (ns) root length 2.23 1.30 1.71 0.090 (ns) pulp length 0.29 0.65 0.45 0.656 (ns) root width at cej 3.85 2.67 1.44 0.152 (ns) root width at mid-root level -2.61 3.33 -0.78 0.435 (ns) root width at midpoint between cej and mid-root level -0.63 3.65 -0.17 0.863 (ns) pulp width at cej -3.09 3.47 -0.89 0.375 (ns) pulp width at mid-root level 5.99 3.41 1.76 0.082 (ns) pulp width at midpoint between cej and mid-root level -3.11 3.56 -0.87 0.386 (ns) tooth area 0.09 0.14 0.67 0.504 (ns) pulp area -0.69 0.38 -1.82 0.073 (ns) table 2: regression analysis for all morphological variables (predictors) and age as the dependent variable in females (n = 132) model regression coefficients s.e. significant level t-test p-value constant -1.90 22.43 -0.08 0.933 (ns) tooth length -0.86 1.42 -0.61 0.546 (ns) root length 2.54 1.41 1.81 0.074 (ns) pulp length 0.09 1.25 0.07 0.946 (ns) root width at cej 3.67 3.62 1.01 0.313 (ns) root width at midroot level 0.45 3.82 0.12 0.907 (ns) root width at midpoint between cej and midroot level 2.81 4.40 0.64 0.524 (ns) pulp width at cej 12.46 5.64 2.21 0.29(ns) pulp width at midroot level -1.43 6.73 -0.21 0.833 (ns) pulp width at midpoint between cej and midroot level -6.27 6.39 -0.98 0.328 (ns) tooth area -0.14 0.23 -0.60 0.553 (ns) pulp area -0.60 0.76 -0.80 0.428 (ns) j bagh college dentistry vol. 25(4), december 2013 digital panoramic oral diagnosis 47 table 3: regression analysis for all morphological variables (predictors) and age as the dependent variable in the total study sample (n = 240) model regression coefficients s.e. significant level t-test p-value constant 18.73 12.93 1.45 0.149 (ns) tooth length -1.65 0.93 -1.76 0.079 (ns) root length 2.55 0.88 2.91 0.004 ** pulp length 0.27 0.57 0.48 0.629 (ns) root width at cej 2.80 2.18 1.28 0.201 (ns) root width at mid-root level -1.75 2.43 -0.72 0.473 (ns) root width at midpoint between cej and mid-root level 1.06 2.79 0.38 0.705 (ns) pulp width at cej 3.54 2.55 1.39 0.166 (ns) pulp width at mid-root level -0.09 2.40 -0.04 0.971 (ns) pulp width at midpoint between cej and mid-root level 1.46 2.69 0.54 0.590 (ns) tooth area 0.06 0.12 0.52 0.605 (ns) pulp area -0.92 0.30 -3.12 0.002 ** table 4: comparison between real and estimated age in subjects grouped according to age.(years) age groups (years) age in years (mean ± sd) significant level real age estimated age t-test p-value 20-29 24.89 ± 1.89 24.72 ± 2.78 -0.49 0.873 (ns) 30-39 34.66 ± 2.89 34.42 ± 2.97 -0.65 0.762 (ns) 40-49 44.82 ± 2.58 44.22 ± 2.98 1.33 0.640 (ns) 50-59 54.70 ± 2.78 54.78 ± 2.89 0.61 0.733 (ns) over all 36.62 ± 11.45 36.56 ± 2.98 0.08 0.936 (ns) table 5: comparison between real and estimated age of subjects according to gender.(years) gender age in years (mean ± sd) significant level real age estimated age t-test p-value male 36.19 ± 10.44 36.67 ± 2.99 -0.51 0.609 (ns) female 36.97 ± 12.25 36.47 ± 2.96 0.48 0.632 (ns) over all 36.62 ± 11.45 36.56 ± 2.98 0.08 0.936 (ns) discussion the result of the present study showed that the regression analysis for all morphological variables (predictors) with age as the dependent variable showed no significant differences when compared between real age and estimated age in both males and females, as described in table 1 and 2 respectively. and for the total study sample the regression analysis for all morphological variables (predictors) with age as the dependent variable showed nonsignificant differences when compared between real age and estimated age with exception of root length and pulp area which showed statistically significant differences between real age and estimated age in the total study sample(p-value for root length 0.004 and pvalue for pulp area 0.002) as described in table 3, so by using age as the dependent variable and root length and pulp area as the independent variable, the linear regression formula obtained in the current study to calculate or estimate chronological age for iraqi population was: age = 18.73+2.55*(root length)-0.92*(pulp area). cementum keeps forming throughout life, the continuous apposition of cementum is influenced by the functional state and dental changes like attrition and abrasion, correlation between age and root length infers the formation of cementum at the root apex with aging (6). secondary dentin with advancing age is deposited along the wall of the dental pulp chamber leading to a reduction in the size of the pulp cavity (14). the pulp area acts as indicator of age because area decrease is due to secondary dentin formation (11). saxena (12) studied the age estimation by direct orthopantomographs of 120 canines (maxillary right canine) of indian patients of both sexes with age ranging (21-60 years old), and by measuring the same variables used in the present study and according to the total sample, he found that pulp/tooth area ratio and pulp/root width ratio at j bagh college dentistry vol. 25(4), december 2013 digital panoramic oral diagnosis 48 mid root level showed significant differences, he put regression model for age calculation as follow: age = 72.48-203.74*pulp/tooth area ratio -5169*pulp/root width ratio at mid-root level. this formula was designed for indian population indicating that racial and cultural factors might play an important effect on age estimation. the present study showed that comparison between real and estimated age in relation to age groups showed no significant difference for all the age group(2), table 4. the accuracy of age estimation diminishes with age, the possible reasons might be the reduction of the criteria and signs for the estimation of opgs in older persons and the variability of the oral health status of patients in older age groups (8). the present study showed no significant influence of gender on age estimation using canine tooth measurements (3). panoramic images are useful in the demonstration of the complete dentition, position and anatomy of the teeth including maxillary canines (7). the current study performed on single tooth since accurate measurements are difficult to perform on multirooted teeth, and in order to create a uniform amount of distortion in all images, as the curved arch of the jaw is projected on to a flat film, so there will always be a certain amount of distortion when measuring the image (13). references 1al-amad sh. forensic odontology. smile dent j 2009; 4(1): 22-4. 2alsaadi mh. chronological age estimation by radiographical measurements on digital panoramic image among iraqi sample (forensic odontological study). m.sc. thesis, college of dentistry, baghdad university, 2008. 3cameriere r, cunha e, sassaroli e, nuzzolese e, ferrante l. age estimation by pulp/tooth area ratio in canines. forensic sci int 2009; 193: 128el128eb. 4cameriere r, ferrante l, belcastro mg, bonfiglioli b, rastelli e, cingolani m. age estimation by pulp/tooth ratio in canines by peri-apical x rays. j forensic sci 2007; 52(1):166-70. 5jain rk, rai b. age estimation from permanent molar’s attrition of haryana population. indian j forensic odontol 2009; 2(2): 59-61. 6jayawardena ck, abesundara ap, nanayakkara dc, chandrasekara ms. age-related changes in crown and root length in sri lankan sinhalese. j oral sci 2009; 51(4): 587-92. 7jose m, varghese j. panoramic radiograph a valuable diagnostic tool in dental practicereport of three cases. int j dent clin 2011; 3(4): 47-9. 8karaarsian b, karaarsian es, ozsevik a-s, ertas e. age estimation for dental patients using orthopantomographs. eur j dent 2010; 4(4): 389-94. 9kaushal s, patnaik vvg, agnihotri g. mandibular canines in sex determination. j anat soc india 2003; 52: 119-24. 10kvaal s i, koltveit k m, thomsen io, solheim t. age estimation of adult from dental radiographs. forensic sci int 1995; 74(3): 175-85. 11rai b, anand sc. secondary dentin for age determination. int j forensic sci 2007; 2(1): 1-3. 12saxena s. age estimation of indian adults from orthopantomographs. braz oral res 2011; 25(3): 2259. 13singaraju s, sharada p. age estimation using pulp/tooth area ratio: a digital image analysis. j forensic dent sci 2009; 1(1): 37-41. 14solheim t. dental cementum apposition as an indicator of age. scand j dent res1990; 98, 510-519. 15white sg, pharaoh mj. oral radiology clinical and interpretation. 6th ed. mosby; 2009. pp. 677-683. raja f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the study of oral diagnosis 67 the study of tempromandibular joint disorders and anticyclic citrullinated peptide antibodies in serum and saliva of patients with rheumatoid arthritis raya m. khidhir, b.d.s. (1) raja h. al-jubouri, b.d.s., m.sc., ph.d. (2) abstract background: rheumatoid arthritis is an autoimmune disease that affects mainly the synovial membranes and articular structures and is characterized by chronic, systemic inflammation involving multiple joints.being a synovial joint, the temporomandibular joint is subject to the same disorders affecting other synovial joints, including ra.beside it was considered as a specific serological marker for diagnosing ra disease ,antibodies to cyclic citrullinated peptide have proven to be associated with joints destruction, though; it may play a potential role in the prediction of the disease severity. materials and methods: sixty nine individuals (69) were enrolled in this study, forty nine (49) were patients diagnosed with rheumatoid arthritis, and twenty (20) were healthy control subjects. blood and saliva samples were taken from each subject for immunological analysis of anti-cyclic citrullinated peptides antibodies by elisa. each patient with rheumatoid arthritis disease was examined by means of research diagnostic criteria for temromandibular disorders for the assessment of tempromandibularjoint involvement. results: frequency of positive serum anti-ccp antibodies was higher in rheumatoid arthritis patients compared to healthy controls (p=0.000).tempromandibular joint clinical findings were bilaterally involved except joint sounds, sometimes; it was unilateral. chronic rheumatoid arthritis patients associated with higher prevalence of tempromandibular joint disorders than newly diagnosed ra, except limited mouth opening which were prevalent in newly diagnosed ra patients, (p=0.012) was significant.positive serum anti-ccp rheumatoid arthritis patients were associated with higher frequency of tempromandibular joint disorderscompared with ra patients with negative serum anti-ccp, a non-significant difference was found. conclusions:anti-cyclic citrullinated peptide antibodies are considered as a biomarker of inflammation and disease activity. tempromandibular joint disorders are frequently involved in rheumatoid arthritis patients. rheumatoid arthritis patients with positive serum anti-cyclic citrullinated peptides antibodies associated with higher frequency of tempromandibular joint disorders. keywords: rheumatoid arthritis, tempromandibularjoint, anti-cyclic citrullinated peptide antibody. (j bagh coll dentistry 2013; 25(special issue 1):67-71). introduction rheumatoid arthritis (ra) is a systemic autoimmune disease that may affect many tissues and organs, but is mainly characterized by chronic inflammation of the joints. the inflammation leads to joint destruction, joint deformity with loss of function and increased mortality (1). rheumatoid arthritis causes chronic inflammation in joint tissues; it is usually seen in other joints prior to temporomandibular joint involvement. the common clinical tmj findings in rheumatoid arthritis are tenderness, pain, clicking, crepitation, stiffness, and limitation in jaw movements (2). the publication in 1992 of the research diagnostic criteria for temporomandibular disorders (rdc/tmd) provided clinicians and investigators with a precise and reliable tool for diagnosing the most common alterations of the tmj. group iii of axis i of this classification includes the sub-categories arthralgia, osteoarthritis and osteoarthrosis(3). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. until recently, assays detecting rheumatoid factor (rf), antibodies directed against the fc portion ofthe igg molecule, have been the primary serologic testin diagnosis ofra.however, rf antibodies are not very specificfor this disease and can also be detected in other rheumatic disorders, infections, and in 3-5% of apparently healthy individuals(4). recently, antibodies directed to citrulline-containing proteins, which appear to bea promising alternative of rf in the diagnosis of ra .anti-ccp antibodies is specific for ra and appear early in the disease, often even preceding the symptoms of ra . moreover, anticcp is a reliable predictor of a progressive and erosive course of ra (5,6). the aims of the study were: 1. assessment of anti-cyclic citrullinated peptide (anti-ccp) antibodies in serum and saliva of patients with rheumatoid arthritis and compare the results with those of healthy control subjects. 2. study the prevalence of tempromandibular joint disorders in rheumatoid arthritis patients. j bagh college dentistry vol. 25(special issue 1), june 2013 the study of oral diagnosis 68 materials and methods the study was conducted in al-kindi teaching hospital and baghdad teaching hospital.the study samples consist of forty nine rheumatoid arthritis patients sub grouped intofifteen newly diagnosed rheumatoid arthritis of a duration less than one year,and thirty four chronic rheumatoid arthritis patients. apparently healthy controls group were twenty subjects.tempromandibular joint disorders were evaluated according to the rdc/tmd (3),and the examination included:range of mouth opening(limitation),joint sounds,palpation of masticatory muscles, palpation of tmj sites.determination of serum and saliva anticyclic citrullinated peptide antibodies was done by means of enzyme linkedimmunosorbent assay, usingigg elisa (aeskulisa)2-kits. statistical analysis graphical presentation by using: cluster bar charts.inferential data analysis by using chisquare statistic, likelihood ratio test, fisher exact probability test, contingency coefficients test for the cause’s correlation ship of the association tables and odds ratio. results laboratory results of anti-cyclic citrullinated peptide antibodies results in table (1) reveal that from overall 49 ra patients, 35 (71.4%) were with serum positive anti-ccp antibodies and the remainder ra patients were 14 (28.6%) with serum negative anti-ccp antibodies. healthy controls have had non results of serum anti-ccp0 (0.00%), thus, a highly significant differences was found (p=0.000) .results in table(2) reveal that eleven 11(73.3%) of the newly diagnosed ra patients were with serum positive anti-ccp and remainder were with serum negative anti-ccp 4 (26.7%).twenty four 24 (70.6%) of the chronic ra patients were with serum positive anti-ccp and remainder were with serum negative anticcp 10 (29.4%), though, a non-significant differences was found (p=0.845). the prevalence of tempromandibular joint disorders among newly diagnosed and chronic rheumatoid arthritis patients figure (1) illustrates the prevalence of tmj clinical findings among the two groups of ra. temporalis muscle’s tenderness was found in 12(80.0%) of newly diagnosed ra patients, and in 24(66.7%) of chronic ra patients. masseter muscle’s tenderness was found in 2(13.3%) of newly diagnosed ra patients, and in 12 (35.3%) of chronic ra patients. lateral poles of tmj was found tender in 13 (86.7%)of newly diagnosed ra patients, and in 22 (64.7%)of chronic ra patients. posterior attachments was found tender in 7(46.7%) of newly diagnosed ra patients, and in 19(55.9%) of chronic ra patients, nonsignificant differences was found when p>0.05 regarding muscles and joint tenderness between newly diagnosed and chronic ra patients.limited mouth opening was significantly prevalent in 12(80.0%) of newly diagnosed ra patients compared with 14 (41.2%) of chronic ra patients, a significant differences was found p=0.013 between newly and chronic ra patients.joint sounds was the only tmj clinical finding that was detected unilateral in some ra patients 11(22.4%), they were 8 (23.5%) in chronic ra patients and 3 (20%) in newly diagnosed ra patients. bilateral joint sounds among ra patients was detected in 9 (18.45%), they were 8 (23.5%) in chronic ra patients and 1 (6.7%) in newly ra patients. statistically,a nonsignificant difference was found p=0.259 between newly diagnosed and chronic ra patients. the prevalence of tempromandibular joint disorders among ra patients with serum positive and negative anti-ccp antibodies figure (2) illustrates the prevalence of tmj clinical findings among serum positive and negative ra patients. the frequency of temporalis muscle’s tenderness was found in 25 (71.4%) of serum positive anti-ccp compared with 11 (78.6%) of serum negative ra patients. frequency of masseter muscle’s tenderness was found in 10 (28.6%) of serum positive compared with 4 (28.6%) of serum negative anti-ccp ra patients. frequency of tenderness of tmj’s lateral poles was found in 25 (71.4%) of positive serum anti-ccp compared with 10 (71.4%) of negative serum anti-ccp ra patients. frequency of tenderness of tmj’s posterior attachments was found in 20 (57.1%) of positive serum anti-ccp compared with 6 (42.9%) of negative serum anticcp ra patients.frequency of limited mouth opening was found in 20 (57.1%) of positive serum anti-ccp compared with 6 (42.9%) of negative serum anti-ccp ra patients. frequency of joint sounds was found in 17(48.6%) of positive serum anti-ccp compared with 3 (21.4%) of negative serum anti-ccp ra patients, a non-significant differences was found regarding all those findings between serum positive and negative ra patients when p>0.05. discussion positive serum anti-ccp antibodies among the studied groups high frequency of positive serum anti-ccp test was significantly found among ra groups j bagh college dentistry vol. 25(special issue 1), june 2013 the study of oral diagnosis 69 71.4% compared with 0.00% in healthy controls, these findings correlates with (7), who reported relatively similar results with a positive serum anti-ccp 79% among ra patients, and none of the healthy controls’ sera were positive for anticcp. on the other hand, the current study results are inconsistent with studies of (8), who reported that 58% of ra patients were positive for anticcp and (9) who suggested that citrullinated collagen-ii results in 40% positivity for anticcp, which is too low in comparison with results of the current study.in addition,results revealed high frequency of anti-ccp positivity among newly diagnosed ra 73.3% compared with 70.6% for chronic ra. a non-significant difference was found statistically. an iraqi study carried by (10)proposed 70% positivity for early ra and 95% for chronic ra patients compared with 0.0% for healthy controls. prevalence of tempromandibular joint disorders among the two groups of rheumatoid arthritis patients bilateral tmj findings were detected among the ra patients frequent muscle tenderness including the temporalis and masseter musclewas found prevalent in chronic ra more than newly diagnosed ra patients. ardic et al. reported muscle tenderness in ra patients secondary to tempromandibular joint involvement, and stated that if a joint is not functioning normally a patient will often develop muscle tenderness that can be experienced as facial pain (11) .frequent joint tenderness in the area of lateral pole and posterior attachment was found prevalent in chronic more than newly diagnosed rapatients.this is in agreement with studies (12, 13,14)they found bilateral tmj pain in patients with rheumatoid arthritis which might be due to increase in pressure within the joint capsule as the pannus extrudes itself into the inter bony spaces but before any significant bone resorption has taken place.mouth opening was reduced in 53.1% of ra patients, and furthermore it was prevalent in the newly diagnosed ra patients compared with chronic ra patients. previous studies report that complains of limitation in mouth opening is common in more than half of ra patients (15, 16, 17)and could be as a result of intra-articular fibrous adhesions or due to displacement of the disc(18). joint sounds was the only tmj finding that was sometimes detected unilateral, however it was frequently detected in the chronic more often than newly diagnosed ra patients, agreed with (18), they reported somehow similar findings and stated that a disturbance in the normal anatomic relationship between the disc and condyle that interferes with smooth movement of the joint and causes momentary catching, clicking or popping (19) . the prevalence of tempromandibular joint disorders among ra patients with serum positive and negative anti-ccp antibodies results revealed that ra patients with positive serum anti-ccp have been found to exhibit clinical tmj disorders more often than ra patients with negative serum anti-ccp after evaluating tmj findings by rdc/tmd which suggests that positive serum anti-ccp ra patients associated with significant prevalence of tmj disorders.correlation of positive anti-ccp and the degree of joints involvement, including tmj in ra disease, have been previously investigated by (20). they stated that ra patients with positive serum anti-ccp develop more progressive and significant disease course than ra patients with negative anti-ccp, and interestingly; tmj was the last joint with its prevalence rate among anti-ccp positive patients compared with joints such as meta carpophalangeal (mcp) or proximal interphalangeal (pip). for the best of knowledge this is the first study that proposed tmj clinical findings in relation to anti-ccp antibody status by means of rdc/tmd. references 1. alamanos y, drosos aa. epidemiology of adult rheumatoid arthritis. autoimmune rev 2005; 4(3):130-6. 2. helenius l, hallikainen d, helenius i, meurman j, könönen m, leirisalo-repo m, et al. clinical and radiographic findings of the temporomandibular joint in patients with various rheumatic diseases. a case control study. oral surg oral med oral pathol oral radiol endod 2005; 99:455-463. 3. dworkin sf, leresche l. research diagnostic criteria for temporomandibular disorders: review, criteria, examinations and specifications, critique. j craniomandib disord 1992; 6:301-55. 4. vallbracht i, rieber j, oppermann m, fo¨rger f, siebert u, helmke k. diagnostic and clinical value of anti-cyclic citrullinated peptide antibodies compared with rheumatoid factor isotypes in rheumatoid arthritis. ann rheum dis 2004; 63:1079–1084. 5. schellekens g, visser h, de jong b de, et al. the diagnostic properties of rheumatoid arthritis antibodies recognizing a cyclic citrullinated peptide. arthritis rheum 2000; 43:155-64. 6. nielen m, van schaardenburg d, reesink h, et al. specific autoantibodies precede the symptoms of rheumatoid arthritis: a study of serial measurements in blood donors. arthritis rheum2004; 50: 380–386. 7. vasishta a. diagnosing early-onset rheumatoid arthritis: the role of anti-ccp antibodies. am clin lab 2002; 21:34–6. 8. ronnelid j, wick m, lampa j. longitudinal analysis of citrullinated protein/ peptide antibodies (anti-cp) during 5 years follow up in early rheumatoid arthritis: anti-cp status predicts worse disease activity and j bagh college dentistry vol. 25(special issue 1), june 2013 the study of oral diagnosis 70 greater radiological progression. ann rheum dis 2005; 64: 1744-1749. 9. burkhardt h, sehnert b, bochermann r. humoral immune response to citrullinated collagen type ii determinants in early rheumatoid arthritis. eur j immunol 2005; 35: 1643-52. 10. el-saffar j. role of anti-cyclic citrullinated peptide antibodies and interleukins-2, 6 in diagnosis of rheumatoid arthritis in iraqi patients. a dissertation. college of science / university of baghdad. microbiology; 2008. 11. ardic f, gokharman d, atsu s, guner s, yilmaz m, yorgancioglu r. the comprehensive evaluation of temporomandibular disorders seen in rheumatoid arthritis. australian dental journal 2006; 51:(1):23-28. 12. tegelberg a, kopp s. clinical findings in the stomatognathic system for individuals with rheumatoid arthritis and osteoarthrosis. acta odontol scand 1987; 45:65 75. 13. movahedian b, razavi m, movahedian a, moeini m. assessment of manifestations of temporomandibular joint involvement in rheumatoid arthritis patients. j isfahan dental school 2006; 2(3): 1385. 14. hussein am. the study of oral manifestations, apoptotic activity and rheumatoid factor in serum and saliva of rheumatoid arthritis patients. a master thesis. department of oral diagnosis. college of dentistry/ university of baghdad, 2011. 15. kallenberg a, wenneberg b, carlsson g, ahlmen m. reported symptoms from the masticatory system and general well-being in rheumatoid arthritis. j oral rehab1997; 24: 342–349 (ivsl). 16. yamakawa m, ansai t, kasai s, ohmaru t, takeuchi h, kawaguchi t, takehara t. dentition status and temporomandibular joint disorders in patients with rheumatoid arthritis. cranio 2002; 20(3): 165–171. 17. lin y, hsu m, yang j, liang t, chou s, lin h. temporomandibular joint disorders in patients with rheumatoid arthritis. j chin med assoc 2007; 70:527 534. 18. aliko a, ciancaglini r, alushi a, tafaj a, ruci d. temporomandibular joint involvement in rheumatoid arthritis, systemic lupus erythematosus and systemic sclerosis. int j oral maxillofac surg 2011; 40: 704– 709. 19. laskin dm. internal derangements. oral maxillofac surg clin north am 1994; 5: 217–222. 20. van der helm-van mil a, verpoort k, breedveld f et al. antibodies to citrullinated proteins and differences in clinical progression of rheumatoid arthritis. arthritis research & therapy 2005; 7: 949-958. table 1: distribution of the studied samples according to positive serum anti-ccp with comparisons significant serum anti-ccp freq.’s &percents the studied groups total c.s. (*) p-value healthy control rheumatoid arthritis negative freq. 20 14 34 c.c.=0.544 p=0.000 hs % serum anti-ccp 58.8% 41.2% 100% % the studied groups 100% 28.6% 49.3% positive freq. 0 35 35 % serum anti-ccp 0.0% 100% 100% % the studied groups 0.0% 71.4% 50.7% (*) hs: highly significant at p<0.01 table 2:distribution of the ra groups according to positive serum anti-ccp with comparisons significant serum anti-ccp freq.'s &percents the studied groups total c.s. (*) p-value newly diagnosed ra chronic ra negative freq. 4 10 14 c.c.=0.028 p=0.845 ns % serum anti-ccp 28.6% 71.4% 100% % the studied groups 26.7% 29.4% 28.6% positive freq. 11 24 35 % serum anti-ccp 31.4% 68.6% 100% % the studied groups 73.3% 70.6% 71.4% (*) ns : non significant at p >0.05 j bagh college dentistry vol. 25(special issue 1), june 2013 the study of oral diagnosis 71 figure 1: tmj clinical findings among ra patient group figure 2: tmj clinical findings among positive and negative serum anti-ccp ra patients jinan f.doc j bagh college dentistry vol. 25(3), september 2013 the relation between pedodontics, orthodontics and preventive dentistry149 the relation between facial prognathism and cervical posture in skeletal class i iraqi adult sample hayder j. attar, b.d.s., m.sc. (1) jinan aliwee, b.d.s., m.sc. (2) ali m. hameed, b.d.s., m.sc. (2) aabbssttrraacctt background: biologic mechanisms of the form-function interaction are one of important component of orthodontic diagnosis. the purpose of this study is to search for the statistical associations between natural postural and craniofacial morphologic variables of the head. materials and methods: the sample comprised natural head posture (nhp) cephalograms of 90 subjects, aged 18 to 25 years. interpretation of the facial structure was made by using both intracranial and the extra-cranial reference lines in autocad computer program. results the measures of anteroposterior maxillary position, sna showed a low negative correlations with the anterior cranial base angulation to true vertical (sn.ver) and with the cranio-cervical position of the head (sn.opt),(sn.cvt) the measures of anteroposterior mandibular position, snb and snpog, both showed moderate correlations with the anterior cranial base angulation to true vertical (sn.ver) and with the cranio-cervical position of the head (sn.opt),(sn.cvt) .. cconclusion regarding the correlations between the variables indicating the degree of facial prognathism in the nhp, and the postural variables of the cervical column, it can be argued that in subjects with forward cervical inclination, a relative decrease in facial prognathism is expected. keywords: natural head posture, autocad computer program. (j bagh coll dentistry 2013; 25(3):149-152). iinnttrroodduuccttiioonn in the orthodontic literature, there are a number of studies of associations between head posture and dentofacial morphology 1-6. these studies led to the development of the so called "soft tissue stretching" hypothesis7. according to bench 8 vertical growth of the face after puberty has a high correlation with neck growth, so that patients with dolicocephalic faces often have a tendency for the cervical column to be straight and long, whereas brachycephalic patients often have a curved cervical column. in line with this concept, it was suggested by houston9 that the growth of the cervical column is the primary factor determining growth of anterior face height. the atlas was considered of particular interest to the orthodontist. von treuenfels 10 observed that the inclination of the atlas is associated with the sagittal jaw position in that the ventral arch of the atlas attains a more cranial position in progenic than in orthogenic patients. in order to obtain optimal cephalometric assessment of craniocervical angulations, it has been strongly advocated that the lateral cephalograms should be taken with the teeth in occlusion and the subject sitting upright 3or standing upright 2with the head and cervical column in the natural position (2, 4) (1) assistant lecturer, orthodontic department, college of dentistry, baghdad university. (2) lecturer, orthodontic department, college of dentistry, baghdad university. natural head position is the relationship of the head to the true vertical 11; in cephalometric radiographs it is a standardized orientation of the head in space. since the natural head position uses an extra-cranial reference line, it obviates reliance on any intracranial reference planes 13. the aim of this study was to search for the associations between postural and morphologic variables of the head in a sample taken from iraqi population. examining more specifically whether the head extension or flexion could affect the facial anteroposterior relation. mmaatteerriiaallss aanndd mmeetthhooddss samples selection ninety lateral cephalometric digital radiographs in natural head position (nhp) were collected from students at the college of dentistry, university of baghdad, and subjects attended the orthodontic department of the baghdad dental college. the age ranged between 18-25 years with a class i skeletal relationship, the value of anb 2-4o. every lateral cephalometric radiograph was analyzed by autocad program 2011 to calculate the cephalometric measurements on which the points and planes were determined, and then the measurements were obtained. landmark definitions the reference points of this study are shown in fig. 1. the following points were used in this study and defined according to rakosi 12: sella (s), nasion (n), point (a), point (b), pogonion (pog). j bagh college dentistry vol. 25(3), september 2013 the relation between pedodontics, orthodontics and preventive dentistry150 the following points were used in this study and defined according to solow and tallgren2: 1. cv2ap the apex of the odontoid process of the second cervical vertebrae. 2. cv2ip the most posterior and inferior point on the corpus of the second cervical vertebrae. 3. cv2tg tangent point of opt on the odontoid process of the second cervical vertebrae. 4. cv4ip the most posterior and inferior point on the corpus of the fourth cervical vertebrae. reference lines the cephalometric reference lines (fig. 1), used in this study according to solow and tallgren2 are: 1. true vertical reference line (ver): this line passes through point pns, parallel to the radiographic image of the vertical chain, and is 90° to the true horizontal. 2. true horizontal reference line (hor): the line perpendicular to ver. 3. odontoid process tangent (opt): the posterior tangent to the odontoid process through cv2ip. 4. cervical vertebrae tangent (cvt): the posterior tangent to the odontoid process through cv4ip. 5. sella nasion (sn) 12: anteroposterior extent of anterior cranial base. figure 1.the reference points and lines of this study variables (table i., figure: 2) 1. sn-ver the anterior cranial base in relation to the true vertical line angle between the sn line and the true vertical line. 2. sn opt the head position in relation to the cervical column angle between the sn line and the odontoid process tangent (opt)2. 3. sn cvt the head position in relation to the cervical column -angle between the sn line and the cervical vertebrae tangent (cvt)2. 4. opt-hor the inclination of cervical column to the true horizontal angle between the odontoid process tangent (opt) and the horizontal line (hor) 2. 5. cvt-hor the inclination of cervical column to the true horizontal angle between the cervical vertebrae tangent (cvt) and the horizontal line (hor) 2 6. opt-cvt the inclination of the two cervical reference lines to each other, i.e. the cervical curvatureangle between the odontoid process tangent (opt) and the cervical vertebrae tangent (cvt) 2 7. sna: anteroposterior position of maxilla in relation to anterior cranial base (12). 8. snb: anteroposterior position of mandible in relation to anterior cranial base (12). 9. snpog: anteroposterior position of chin in relation to anterior cranial base (12). 10. n-ver: distance of n to true vertical2 11. a-ver: distance of a to true vertical2 12. b-ver: distance of b to true vertical2 13. pog-ver: distance of pog to true vertical2 14. a-ver/n-ver: ratio indicating maxillary prognathism in the nhp2. 15. b-ver/n-ver: ratio indicating mandibular prognathism in the nhp2. 16. pog-ver/ n-ver: ratio indicating chin prognathism in the nhp2. table 1. the variables studied postural variables intra-cranial extra-cranial sn opt opt-hor sn cvt cvt-hor sn-ver opt-cvt facial prognathism intra-cranial extra-cranial sna a-ver/ n-ver snb b-ver/ n-ver snpog pog-ver/ n-ver figure 2. the reference points and lines in autocad program. j bagh college dentistry vol. 25(3), september 2013 the relation between pedodontics, orthodontics and preventive dentistry151 statistical analysis data were statistically analyzed by a software computer program spss, version 15 to obtain descriptive statistics (means, standard deviation), and pearson’s correlation. rreessuullttss the mean values for the craniofacial dimensions and head posture in the study are shown in table 2. anteroposterior maxillary position (table 3) the measures of anteroposterior maxillary position, sna showed a low negative correlations with the anterior cranial base angulation to true vertical (sn.ver) and with the cranio-cervical position of the head (sn.opt), (sn.cvt). these correlations were significant at .001 level. the extra-cranial anteroposterior measures (a.ver/n.ver) showed a low correlation with the cervico-horizontal posture of the head (opt.hor), (cvt.hor) and a negative correlation with cervical curvature (opt.cvt) these correlations were significant at .001 level. anteroposterior mandibular position (table 3) the two measures of anteroposterior mandibular position, snb and snpog, both showed moderate correlations with the anterior cranial base angulation to true vertical (sn.ver) and with the cranio-cervical position of the head (sn.opt), (sn.cvt). these two correlations were significant at .001 level. the extra-cranial anteroposterior measures (b.ver/n.ver) (pog.ver/n.ver) showed a low correlations with the cervico-horizontal posture of the head (opt.hor),(cvt.hor) and a negative correlation with cervical curvature (opt.cvt) these correlations were significant at .001 level. table 2. descriptive statistics of craniofacial and head posture measurements ddiissccuussssiioonn the main goal of study was to search for the associations between posture and structure of the head, and to make some assumption about the possible control mechanisms in craniofacial growth and development. all patients were selected for skeletal classification according to the anb angle. only class i patients with a normal vertical growth pattern were included in the study sample. thus, this study differed from previous studies as a standard and homogenous group of patients was used. as it was aimed to assess the shape of the craniofacial complex, no linear measurements that may show wide variations in persons having similar facial configurations were used. sex differences in craniofacial structure found to exist in linear measurements, rather than in angles therefore, in this study, no distinction was made with regard to sex.14 in this study, conventional angles sna, snb, and snpog were correlated with cranio-vertical and craniocervical postural parameters (sn.ver, sn.opt, and sn.cvt). this is in agreement with the findings of previous studies.2,6 however, when the facial prognathism was assessed in the nhp with parameters that were based on the extracranial reference lines (aver/n-ver, b-ver/n-ver, and pog-ver/nver), they showed positive correlations with sn.ver and negative correlations with the parameters that indicated cervical posture (opt.hor and cvt.hor). it could thus be assumed that, although an increase in the inclination of the sella-nasion reference line results in the relative anterior positioning of the points a, b, and pogonion, in relation to nasion, values of the angles sna, snb, and snpog decrease topographically, which may falsely lead to a conclusion that facial prognathism decreases with the extension of the head. it should be remembered that the inclination of the s-n reference line is mainly due to the vertical anatomic location of sella-turcica, in the nhp. regarding the correlations between the variables indicating the degree of facial prognathism in the nhp, and the postural variables of the cervical column, it can be argued that in subjects with forward cervical inclination, a relative decrease in facial prognathism is expected. in agreement with the findings of solow and correlation with the inclination of the cervical column 2,4. variables mean sd sagittal dimensions intra-cranial sna 84.00 3.2 snb 80.08 3.5 snpog 80.56 3.7 extra-cranial a.ver/n.ver 1.04 0.1 b.ver/n.ver 0.94 0.1 pog.ver/n.ver 0.96 0.1 head posture intra-cranial sn.ver 97.96 3.7 sn.opt 106.00 5.1 sn.cvt 105.36 6.9 extra-cranial opt.hor 98.08 3.7 cvt.hor 97.80 4.4 opt.cvt 3.04 2.3 j bagh college dentistry vol. 25(3), september 2013 the relation between pedodontics, orthodontics and preventive dentistry152 references 1. schwarz am. positions of the head and malrelations of the jaws. int j orthod 1928; 14: 56-68. 2. solow b, tallgren a. head posture and craniofacial morphology. am j phys anthropol 1976; 44: 417-35. 3. marcotte mr. head posture and dentofacial proportions. angle orthod 1981; 51: 208-13.(ivsl) 4. solow b, siersbaek-nielsen s. growth changes in head posture related to craniofacial development. am j orthod 1986; 89:132-40. 5. hellsing e, mcwilliam j, reigo t, spangfort e. the relation between craniofacial morphology, head posture and spinal curvature in 8, 11-and 15-year-old children. eur j orthod 1987; 9: 254-64. 6. showfety kj, vig ps, matteson s, phillips c. associations between the postural orientation of sellanasion and skeletodental morphology. angle orthod 1987; 57: 99-112. (ivsl). 7. solow b, kreiborg s. soft tissue stretching: a possible control factor in craniofacial morphogenesis. scand j dent res 1977; 85: 505-7. 8. bench rw. growth of the cervical vertebrae as related to tongue, face, and denture behaviour. am j orthod 1963; 49: 183-214. 9. houston wjb. mandibular growth rotations their mechanisms and importance. eur j orthod 1988; 10: 369-73. 10. treuenfels von h. die relation der atlasposition bei prognather und progener kieferanomalie. fortschr kieferorthop 1981; 42: 482-4. 11. cole sc. natural head position, posture and prognathism: the chapman prize essay, 1986. br j orthod 1988; 15: 227-39. 12. rakosi t. an atlas and manual of cephalometric radiography. 2nd ed. london: wolfe medical publications ltd.; 1982. 13. moorrees cfa, kean mr. natural head position, a basic consideration in the interpretation of cephalometric radiographs. am j phys anthropol 1958; 16: 213-34. 14. ingerslev ch, solow b. sex differences in craniofacial morphology. acta odont scand 1975; 33: 85-94. table 3. significant correlations (r) between the morphology of the cervical column and craniofacial morphology and head posture in the total group sagittal dimensions head posture correlation sig. correlation sig. correlation sig. intra-cranial sn.opt sn.cvt sn.ver sna -0.30 0.15 -0.10 0.62 -0.30 0.14 snb -0.49 0.01 -0.30 0.15 -0.39 0.05 snpog -0.46 0.02 -0.34 0.10 -0.48 0.01 extra-cranial opt.hor cvt.hor opt.cvt a.ver/n.ver -0.19 0.4 0.47 0.0 -0.14 0.5 b.ver/n.ver -0.30 0.138 0.23 0.27 -0.31 0.128 pog.ver/n.ver -0.25 0.226 0.15 0.49 -0.24 0.246 thikra f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of the restorative dentistry 23 evaluation of the effect of addition of polyester fiber on some mechanical properties of heat cure acrylic resin thikra m. hachim, b.d.s., m.sc. ph.d. (1) zainab s. abullah, b.d.s., m.sc. (1) yasamin t. alausi, b.d.s., m.sc. (1) abstract background: this study aimed to evaluate the effect addition of polyester fibers on the some mechanical properties of heat cured acrylic resin (implant strength, flexural strength and hardness) materials and methods: ninety specimens were used in the study. thirty specimens were used for impact strength measurements (80mm x 10mm x 4mm) length, width and thickness respectively. the specimens divided into three test groups (n=10), first group formed from heat cure acrylic resin without fiber reinforcement. second group was formed from heat cure acrylic resin was reinforced with 2 mm length polyester fiber and third group was formed from heat cure acrylic resin reinforced with 4mm length polyester fiber, impact strength measured by impact testing device. 30 specimens with (65 mm x 10mm 2.5mm) length, width and thickness respectively were used in 3 groups (n=10) flexural strength test. the flexural strength was measured by using flexural testing device. 30 specimens with (65mm x 10m x 2.5mm) length width and thickness respectively were used for hardness test. the specimens were divided into 3 group (n=10) as in impact strength and flexural strength. hardness measured by using (shore d hardness tester th210). results: revealed statistically significant increase on impact strength especially on 4mm length when compared to control group. significant decreases in flexural strength of pmmp. when compared to control group with 4mm length fiber reinforcement. non significant decrease when compared control group with 2mm length fiber reinforced pmma. significant decrease in hardness of pmma resin after reinforcement with 2mm, 4mm lengths polyester fibers. conclusions: strengthening with the polyester fiber decreased the flexural strength and hardness of the resin, but increased impact strength. thus when high impact acrylic resins are needed, fiber reinforced resins may be the material of choice. keywords: heat cure acrylic resin, polyester fibers. (j bagh coll dentistry 2013; 25(special issue 1):23-29). الخالصة ).صالدة السطح,قوة الطي,مقاومة الصدمة (یم تاثیر اضافة الیاف البولیستر لالكریلك الحراري على بعض الخواص المیكانیكیة لالكریلك الحراري الھدف من ھذا البحث لتقی السمك بالتتالي النماذج قسمت ,ضالعر, الطول ) ملم4*ملم10*ملم80(نموذج لقیاس قوة الصدمة بقیاسات 30, نموذج لكل خاصیة 30نموذج وقد قسمت الى 90استخدم في البحث المجموعة الثالثة ,ملم2المجموعة الثانیة شكلت باضافة االلیاف بطول ,لالختبار المجموعة االولى شكلت من االكریلك الحراري بدون اضافة االلیاف ) 10=العدد(الى ثالثة مجموعات .یاس الصدمة مقاومة الصدمة قیست بواسطة جھاز ق. ملم4شكلت باضافة االلیاف بطول لكل مجموعة وتم قیاس قوة الطي بجھاز ) 10=العدد( قسمت الى ثالثة مجامیع,السمك بالتتالي ,العرض,الطول )ملم2,5* ملم10*ملم65(نموذج استخدمت لقیاس قوة الطي بقیاسات 30 .لطي نموذج استخدمت لقیاس صالدة السطح بنفس القیاسات المستخدمة لقیاس قوة ا 30. قیاس قوة الطي ملم مع نقصان غیر ملحوظ بعد 4ملم ونقصان ملحوظ في قوة الطي بعد اضافة االلیف بطول 4عكست النتائج زیادة ملحوظة في مقاومة الصدمة وخاصة بعد اضافة االلیف بطول افة الیاف البولستر تقلل من قوة الطي والصالدة ولكن تزید من مقاومة ھذه الدراسة استنتجت ان اض. نقصان غیر ملحوظ لكال الطولین على صالدة السطح. ملم2اضافة االلیاف بطول ال .الصدمة ولذلك عندما نرید ان نستخدم االكریلك الحراري ذو المقاومة العالیة للصدمة نستخدم االكریلك الحراري المدعم بالیاف البولیستر introduction heat polymerized polymethly methacrylate (pmma) is the most widly used material in prosthetic dentistry. superior esthetic ease processing, accurate fit, used with inexpensive equipment and repairability, make pmma as a material of choise for denture base fabrication. despite these excellent properties pmma is not metting all the necessary requirement, and primary proplem is its poor strength characteristics, including low impact and flexural strength(1-3). many attempts have been made to enhance the strength properties of acrylic denture base. one of the most common reinforcing technique was the use of metal wire embedded in the prosthesis (4,5). (1) lecturer, department prosthodontics, college of dentistry, university of baghdad. in addition to this various type of fiber including carbon fiber (6), aramid fiber (7), polyetheylene fiber (8),and glass fiber (9) have been investigated as reinforcing material, and it has been shown that the fibers increase the flexural strength and impact strength of denture base polymer. carbon and aramid fibers strengthened pmma but caused clinical problems, including difficulty polishing and poor esthetics(10). inclusion of metal wire and plate reinforcements resulted in poor aesthetics, restricting their use to location at which aesthetics are least important. in case of polyethylene fibers, the surface treatment to improve the adhesion between fibers and denture base polymer is complicated and has not resulted in adequate adhesion (11).by contrast glass fibers have better potential for provisional restoration, despite the difficulty of achieving adequate impregnation of fibers with pmma (12). j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of the restorative dentistry 24 fiber reinforcement is depending on many variables including, fiber type, length, form, and arrangement, percentages of fibers in the matrix and fiber matrix bond. polyester fibers are available in monofilament form and belong to the thermoplastic polyester group. they are temperature sensitive and somewhat hydrophobic. polyester fibers were used for reinforcement of acrylic denture base resin but there were little studies about the use of this fiber. hence the purpose of this study was undertaken to determine the reinforcing effect of polyester fibers on impact strength, flexural strength and hardness of heat polymerized polymethyl mathacrylate denture base polymer. materials and methods heat cure acrylic resin (triplex, ivoclar vivadent, germany) was used in this study. the reinforcing material was polyester fiber. three mechanical tests were used in this study: 1impact strength test. thirty specimens were prepared for impact test and devided into three test groups which contained 10 specimens each (n=10). metal dies with dimensions of (80mm x10mm x4mm) length, width, thickness repectively following the iso standared 179-1: 2000(13) were fabricated to prepare the gypsum molds. a thin layer of petroleum jelly was applied over the die and it was invested with type iv gypsum product in the lower half of dental flask when stone was set in the lower half of the flask, a layer of separating medium was applied on the stone and metal die, then upper half of the flask was seated and the flask was filled with dental stone. after one hour the dental flask was opend and the die was carefully removed from the investing material. ten moulds were prepared. the moulds were evaluated for any porosities and roughness. the prepared moulds were immersed in hot water to remove any traces of empurities and to facilitate the application of separating medium. the mould cavities obtained were used for the preparation of test specimens. for control group, ten specimens of polymethyl methacrylate (pmma) were fabricated. polymer and monomer in the ratio of 2.5: 1 by weight was mixed and allowed to reach dough stage. it was kneaded and packed in the mould. the trial closures were performed and excess was removed. the two halves of the flask were pressed together by bench press. curing was carried out by placing clamped flask in water bath at room temperature raised slowly up to 74°c and hold for 2 hours then raised to 100°c and was maintained for 1 hour (14). after completion of polymerization cycle, the flask allowed to cool in water bath to room temperature. specimens were finished and polished after deflsking. the dimension and quality of each specimen were verified and stored in distal water at 37°c for 24 hours in an incubator befor testing. the second group specimens preparation: before mixing of polymer and monomer. polyester fibers were cut into 2mm length and were socked in monomer for 10 minutes in petridish for better bonding of fiber with pmma resin(15). after fiber were removed from the monomer, excess liquid was allowed to dry and fibers (2%by weight) were mixed thoroughly with the polymer powder to disperse the fibers by manual mixing. the polymer containing fibers and monomer was mixed in ratio of 2.5:1 by weight and allowed to reach the dough stage. the mix was packed into the prepared mould. the specimens were polymerized and retrived in the same manner as control group. the third group specimens were prepared from the same percentage of fibers in the polymer but the length of fibers were cut into 4mm length and specimens were prepared as mention before. impact strength test was carried out on unnotched specimens. testing was done on impact testing machine fig(1) with pendulum of s2 scale in an air at 23±2°c. figure 1: impact testing device before testing, pendulum was releated to freely swing in the air to record the air resistance (ar) encountered by free-swinging pendulum. air resistance of 0.9 joules was recorded. the readings were taken on s2 scale where pointer was j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of the restorative dentistry 25 stabilized after swing. the specimen was clamped in position precisely. pendulum was released and reading indicating energy absorbed (ea) to break the specimens on s2 scale was recorded. all the specimens were tested in the same manner. impact strength of specimen was calculated. by using formula: i= x103 i=impact strength in kj/m2. ea=energy absorbed in joules. ar=air resistance in joules. x=specimen thickness (mm). y=specimen width(mm). 2flexural strength test: thirty specimens with dimension of (65mmx10mmx2.5mm) length, width and thickness respectively were prepared for flexural strength test. all the specimens were grouped and fabricatd similar to the specimens prepared for impact test. before testing the specimens were stored in distilled water at 37°c for 48hours the flexural strength was evaluated according to iso/dis 1567 international standard (16) by the three-point bending test fig(2). figure 2: schematic illustration of flexural strength test arrangement figure 3: flexural testing device the test were carried out in air at 21±1°c using flexural-testing device fig(3). aload was applied using a centrally located rod until fracture occurred. the span of this 3-point bending was 50mm. specimens were set wet from the storage container directly onto the testing apparatus. all the specimens were tested in the same manner. the ultimate flexural strength (mpa)) of each specimen was determind with the following formula (17). = where α is considered as flexural strength (mpa) f= the maximum load applied (n) i= the span between the two supports (mm) b=the width of specimen(mm). h=thickness of specimen (mm). 3shore hardness test. thirty specimens were fabricated and grouped similar to the specimens prepared for flexural strength test. the tests were carried out in air at 21±1°c using electrical device (shore d hardness tester th210) fig (4). the hardness number is based on depth of penetration and was read directly from a gauge. the mean difference and standard deviation were calulated for each test and each group (control group, 2mm and 4mm length polyster fiber reinforcement groups) to make comparisons between the different groups tested, independent samples t-test was used for analysis. figure 4: electrical device for shore hardness test results the mean values and standard deviation (sd) of impact strength, flexural streagth and hardness for control group and 2mm, 4mm length polyester fiber reinforced pm/ma are reported in table (1). by using independent samples t-test, the results revealed statistically significant difference between impact strength of fiber reinforced 50mm force sample j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of the restorative dentistry 26 pmma and control group as showing in table(2). the comparative mean values of the impact strength of control group. 2mm fiber reinforcemat and 4mm fiber reinforcement were presented in fig (5) table 1: descriptive statistics of the impact strength, flexural stragth and hardness of control and reinforced pm/ma: control n=10 2mm fiber n=10 4mm fiber n=10 mean sd mean sd mean sd impact strength kj/m2 7.3750 .94288 13.8400 1.04265 18.4020 1.53928 flexural strength map 440.300 8.96970 424.600 26.466 404.3000 12.7283 hardness 85.3500 1.51529 82.7900 1.35355 82.5900 1.670 table 2: independent samples t-test: comparison of impact strength between control group and fiber-reinforced pmma groups. impact strength type t-test for equality of mean t df p-value sig control and 2mm fiber -14.54318 .000 h.s control and 4mmfiber -19.31818 .000 hs 2mm fiber and 4mm fiber -7.76018 .000 h.s *p <0.05 significant. figure 5: graph showing mean impact strength of control and fiber-reingorced pmma (m=10) there was significant decrease in flexural strength of pmma when compared control group with 4mm length fiber reinforcement but this decrease was statistically not significant when compared control group with 2mm length fiberreinforced pmma(table3). the comparative mean values of the flexural strength of pmma of control group, 2mm fiber reinforcement 4mm fiber-reinforcement were presented in fig(6). table 3: independent samples t-test: comparison of flexural strength between control and fiber reinforced pmma groups. flexural strength type test for equality of mean t df p-value sig control and 2mm fiber 1.77 18 .093 ns control and 4mm fiber 7.311 18 .000 s 2mm fiber and 4mm fiber 2.186 18 .042 s *p< 0.05 significant j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of the restorative dentistry 27 figure 6: graph showing mean flexural strength of control and fiber reinforced pmma (n=10). there was significant decrease in hardness of pmma resin after reinforced with polyester fiber as showing in table (4). the comparative mean values of hardness of control group, 2mm fiber reinforcement and 4mm fiber reinforcement were presented in fig-7. table 4: independent samples t-test: comparison of hardnes between contral group and fiber reinforced pmma groups. hardness type t-test for equality of mean t df p-value sig control and 2mm fiber 3.904 18 .001 s control and 4mm fiber 3.869 18 .001 s 2mm fiber and 4mm fiber 0.294 18 .772 n.s *p<0.05 significant figure 7: graph showing mean hardness of control fiber reinforced pmma (n=10). discussion this study demonstrated the effect of polyester fiber reinforcement on the impact strength, flexural strength and hardness of heat polymerized pmma resin. any increase in fiber incorporation beyond 3% by weight will affect the flow of the dough, 4% by weight of fibers represents a large volume of material be wetted by monomer during mixing and may produce dry friable dough (18). this will provide no beneficial effect on strength. for this reason a standard 2% by weight of fiber was added to each specimen in this study. many different stress were applied on denture base acrylic resin. for example intra-orally, repeated masticatory forces lead to fatigue phenomena, while extra-orally, the fracture of acrylic resin dentures as a result of being dropped is a common occurrence and research continues to produce a denture material with impact resistance which must not interfere with other properties of material (19). j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of the restorative dentistry 28 impact strength testing could be carried out on un-notched and notched specimens but notching would have cut the superficial fiber in the specimens, therefore testing was carried out on un-notched specimens. the reinforcement groups with polyester fibers showed statistically significant increase in impact strength compared to the control group specimens as showing in table(2). this might be attributed to presence of reinforced fibers which carry the load a long their length to provide strength and stiffness to the specimen, resulting in higher absorption of energy compared with un-reinforced specimens (20). the impact strength of the specimens reinforced with polyester fiber (4mm length) was much higher than that of (2mm length) and this was agree with study by chen et al (21). specimens contain 2mm length fibers showed decrease in flexural strength which is statistically not significant when compared with control group. the decrease in flexural strength of specimens contains 4mm length fibers was statistically significant when compared with control group. the mean values of flexural strength for control group and 4mm length fiber reinforcement were 440 mpa, and 404mpa respectively. despite the decrease was statistically significant, this decrease didn’t adversely affect the miret of pmma denture base resin. this slight decrease in flexural strength may be attributed to the random orientation of the fibers from the literature it appears that reinforcement is optimized when fibers are laid down in strategic fashion, running parallel to the surface of denture base. in this way their contribution to reinforcement is maximized as fibers at right angle to the surface produce no beneficial effect. how ever, technical difficulties of ensuring that fibers were aligned correctly might overweigh the possible advantage, by complication the technique to such an extent that it becomes impractical 18. in random orientation of fibers, some fibers are oriented to produce beneficial effect and others are of little or no benfit. the ease and simplicity of random orientation would make this technique more acceptable for widespread use, avoiding the necessity of interruption of packing procedures and time consuming placement of oriented fiber. further investigation is required to determine the adequate direction of reinforcing materials against the applied force. the polyester fibers reinforcement showed statistically significant decrease in hardness of reinforced group when compared with control group but clinically this may be not so important because the mean values of control group, 2mm length fiber and 4mm length and 4mm length fiber reinforcement were 85.35, 82.79, 82.59, respectively. thus these fibers can be effectively used to reinforce denture base to minimize denture fracture. this technique can be clinically for constriction of complete dentures and distal extension partial dentures, especially in cases like patients with poor neuromuscular control. we have compared unreinforced and polyster fiber reinforced pmma resin under conventional heat curing techniques. strengthening with the polyester fiber decreased the flexural strength and hardness of the resin, but increased impact strength. thus when high impact acrylic resins are needed, fiber reinforced resins may be the material of choice. references 1jagger dc, harrison a, janket kd. 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elsevier; 2003. pp. 733-734. 15hamza ta, rosenstiel sf, elhosary mm, ibraheem rm. the effect of fiber reinforcement on the fracture toughness and flexural strength of provisional restorative resin. j prosthet dent 2004; 91:288-264. j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of the restorative dentistry 29 16iso/dis 1567. dentistry: denture base polymers. geneva: international organization for standardization. 1998:1-27. 17aydinc, yilmaz h, caglar a. effect of glass fiber rein for cement on the flexural strength of different denture base resin. quintessence 2002; 33: 457-63. 18gutteridge dl. the effect of including ultra-high modulus polyethylene fiber on the impact strength of acrylic resin. br dent j 1998; 164: 177-180. 19graig rg. powers jm. restorative dental materials 11th ed. mosby inc; 2002. pp.643. 20ladizesky nh, pang mk, chow tw, ward im. acrylic resin reinforced will woven highly drawn linear polyethylene fibers. 3. mechanical properties and further aspects of denture construction. aust deat j 1993; 38:28-38. 21chen sy, liany wm, yen ps. re in for cement of acrylic denture base resin by incorporation of various fibers. j biomed mater res 2001; 58(2):203-8. huda.docx j bagh college dentistry vol. 28(1), march 2016 an assessment of oral and maxillofacial surgery and periodontics 109 an assessment of the efficacy of sinus balloon technique on transcrestal maxillary sinus floor elevation surgery huda moutaz asmael, b.d.s. (1) thair abdul lateef, b.d.s., h.d.d., f.i.b.m.s. (2) abstract background: a minimally invasive antral membrane balloon elevation (miambe) has been introduced to overcome the invasiveness of modified caldwell-luc (lateral approach) and the drawbacks of the osteotome (summers' technique) in maxillary sinus floor elevation surgery. materials and methods: a total of 13 adult iraqi patients aged 28-55 years, 4 males and 9 females underwent sinus floor elevation surgery via crestal approach by using sinus balloon technique. a panoramic radiograph and (cone beam computed tomography (cbct)/or medical ct scan) were obtained before and after surgery. postoperative gained bone was assessed and the patient reactions including pain, nasal bleeding, and ecchymosis were recorded. the whole follow up period was 1year following the sinus lift surgery. results:the total performed sinus floor elevation cases were 17 with a total of 27 sinus floor elevation sites. the maximum gained bone with sinus balloon technique was 10.6 mm. twenty three dental implants placed in augmented maxillary sinuses, two implants early failed 8.70 % and the survival rate of the dental implants was (91.30 %). schneider's membrane perforation didn’t occur in any case of this study 0%. conclusion: sinus floor elevation via crestal approach using the balloon technique solve the limitations for original osteotome technique (summers' technique) for cases even when the subantral bone height is less than 3 mm. the utilization of hydraulic pressure in combination with balloon technique also shows a great role in both sinus membrane elevation and as a diagnostic aid of schneider's membrane perforation. key words: sinus lift surgery, antral membrane balloon elevation, schneiderian membrane perforation. (j bagh coll dentistry 2016; 28(1):109-113). introduction the new advances and devices simplified the original techniques used in sinus floor elevation surgery. the sinus membrane elevation conventionally established through two main approaches the modified (caldwell-luc) lateral approach (tatum 1976) (1), or by a more conservative transcrestal approach (summers' technique) 1994(2). lateral window technique can be applied when the subantral bone height is less than 5 mm(3).it is predictable and allow for greater amount of bone augmentation but it need larger surgical access(4),with high risk of schneiderian membrane perforation and possible trauma to intraosseous arterial supply(5,6).on the other hand the osteotome technique is less invasive(7),and associated with less post-operative morbidity(8).however, this technique has several limitations included restricted indications and allow for only minimal amount of bone gain which is 3-4mm(9).later, many modifications established to facilitate and optimize the results achieved with original approaches, among these modifications antral membrane balloon elevation (ambe)via crestal approach has been introduced whichmay extend the indication for transcrestalsinus lift surgery for membrane elevation of up to 10 mm(10). (1)master student. department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2)assistant professor. department of oral and maxillofacial surgery, college of dentistry, university of baghdad. the purpose of this study was to evaluate the efficacy of the balloon technique in sinus elevation surgery and the short term survival rate of the dental implants during the 1st year after placement. materials and methods the present study continued from december 2013 to june 2015in dental college teaching hospital, department of oral and maxillofacial surgery /baghdad university. it based on clinical and radiographical data. the sample included patients with single or multiple missing teeth in the sinus zone of atrophied maxilla in which the subantral bone heightwas ≤ 4 mm for the two stage sinus floor elevation surgery and > 4mm for one-stage sinus floor elevation surgery. inclusion criteria 1. the patient’ age ranged from 20 –70 years. 2. missing tooth (teeth) in the sinus zone of atrophied maxilla in which the subantral distance < 8 mm. 3. healed planned implant site at least 6 months after extraction. 4. healthy person with no history or clinical evidence of specific systemic diseases that may affect the bone healing, dental implant osseointegration and the maxillary sinus health. j bagh college dentistry vol. 28(1), march 2016 an assessment of oral and maxillofacial surgery and periodontics 110 exclusion criteria 1. any local or systemic disease that may affect the bone healing potential, dental implant osseointegration and maxillary sinus condition such as (diabetes, osteoporosis, others). 2. sinusdisease (sinusitis, mucomycosis, retention cyst, mucocele,tumor,polyp,others).the presence or absence of maxillary sinus disease confirmed by preoperative cone beam computed tomography (cbct) scan. 3. history of previous sinus surgery. 4. presence of septa in the planned site for maxillary sinus floor elevation as confirmed by preoperative radiograph (cbct scan). 5. head and neck radiotherapy. figure 1: pre-operative medical ct scan measurements show the height and width of the planned implant site. surgical procedure all the patients rinsed with chlorhexidine 0.2% for 1 min preoperatively.the procedure was performed under local anesthesia (2% lidocaine with 1:100,000 adrenalin as vasoconstrictor, 2.2 ml cartridge). a crestal incision is made slightly with palatal bias and a full thickness flap (extensive flap design) was raised.the drilling site was marked initially by the pilot bur in the center of the alveolar crest and stopped 1 mm below the sinus floor. drilling was done using the dentium (korea) or nucleoss (turkey) implant systems.dental implant bed was enlarged to at least 4.2 mm to allow entry of balloon and the bed was then enlarged until reaching to the final drill determined diameter, as shown in figure 2. figure 2: preparing implant bed by drilling with sequential larger drills. anosteotome tip no d2.0 mm, no d3.0 mm and/or no d3.8 mm from osteotome kit (friadent, company)was inserted and gentle tapping applied by surgical mallet to allow for controlled greenstick fracture of the sinus floor, as in figure (3). entrance into the sinus membrane space (sms)was manifested by changing in the voice resonance and tactile sense of the surgeon. figure 3: controlled green stick fracturing of the sinus floor with osteotome. depending on the residual alveolar bone height, the integrity of the schneiderian membrane can be assessed clinically either by direct vision or by using hydraulic pressure test to elevate and detect the sinus membrane patency, seefigure4. j bagh college dentistry vol. 28(1), march 2016 an assessment of oral and maxillofacial surgery and periodontics 111 figure 4: schneiderian membrane clinically visible of two-stage sinus lift surgery with subantral bone height of 3 mm. hydraulic pressure test was performed by using 50cc disposablesyringe then by introducing the normal saline in each bed with gentle pressure, if there is no evidence of coughing reflex or discharge of saline from the nose, this will confirm theintegrity of the membrane clinically as shown in figure 5. figure 5: initial elevation and assessment of sinus membrane integrity via hydraulic pressure test with injection of 20 cc normal saline. figure 6: the sinus lift balloon was introduced beneath the schneiderian membrane within the sms (sinus membrane space) and inflated. the balloon (genoss company, korea) inserted in the subantral space “beneath the sinus membrane” and then inflated. this procedure was repeated 3-4 times as in figure (6).after the desired sinus membrane elevation was achieved, the gbr barrier membrane inserted in the bed and pushed apically with an osteotome beneath the elevated schneiderian membrane. the particulate bone grafts {βtricalcium phosphate sterile resorbablebone substitute} was then injected in the prepared bed and guided gently beyond the fractured sinus floor beneath the schneiderian membrane with an osteotome. after placement of the required amount of bone substitute for elevation, the dental implants were placed. the length of the placed dental implants were (10 and 12 mm) and diameter were(4.2, 4.3, 4.8, and 5 mm).wound closure was performed utilizing non-absorbable black silk suture gauge 3/0. immediate post-operative periapical radiograph was obtained for immediate assessment of sinus lift surgery as shown in figure 7. figure 7: immediate post-operative periapical radiographs show the amount of bone graft and implants inside the augmented lift maxillary sinus. the post-operative bone gain was measured in the axial view of cbct scan.post-operative opg was taken to all patients 6 months after surgery as in figure 8.follow-up period after treatment was 1 year. figure 8: post-operative opg show distribution of dental implants and the augmented (r and l) maxillary sinuses. j bagh college dentistry vol. 28(1), march 2016 an assessment of oral and maxillofacial surgery and periodontics 112 figure 9: healing abutments in the 2ndstage surgery. figure 10: final prosthesisinside the patient’s mouth. results a total of 13 adult iraqi patients aged 28-57 years, 4 males and 9 females were participated in this study. nine patients underwent unilateral sinus floor elevation surgery and 4patients underwent bilateral procedures. the total performed sinus floor elevation cases were 17 with a total of 27 sinus floor elevation sites. fifteen cases were performed in a single-stage surgery (simultaneous sinus floor elevation and dental implant placement) and 2 cases were performed in a two-stage surgery (sinus floor elevation and delayed dental implant placement 6 months later).the mean bone gain in this study was 6.70 mm and the mean utilized non autogenous bone graft material was 0.74 ccresulting in p value of 0.027 which is significant. the maximum gained bone with sinus balloon technique was 10.6 mm and the minimum of gained bone was 4.9 mm.the mean initial subantral bone height was 5.56 mm (sd = 1.18), while the mean gained bone height 6 months after operation was 6.7 mm (sd = 1.56) with p value of 0.004 which is highly significant. a total of 23 dental implants placed in the augmented maxillary sinus, two implants early failed 8.70 % and the survival rate of the dental implants inside the sinus was 91.30 %. twenty eight dental implants were placed outside the sinus in the same patients, 1 implant early failed 3.57% and 27 dental implants survived with a survival rate of96.42%. the cumulative survival rate of dental implants inside and outside sinus was94.12%.schneiderian membrane perforation didn’t occur in any case of this study 0%. minor post-operative complications were registered involving mild nasal bleeding in one patient and infraorbital ecchymosis in another patient which resolved spontaneously and needed no intervention. discussion schneiderian membrane perforation didn’t occur in any case of this study 0% and this was confirmed clinically in all cases before insertion of (gbr) barrier membrane by direct vision if the subantral bone height was less than 4 mm or by normal saline irrigation test which show absence of coughing reflex and nasal saline discharge. radiographically, cbct scan showed uniform distribution of the bone substitute material around the dental implants, identical consistent dome shape of the bone substitute and no leakage of bone particles from sinus membrane space into the sinus cavity space. absence of schneiderian membrane perforation in all cases could be attributed to the non-traumatic surface of the balloon and gentle slow inflation of sinus balloon. utilization of the hydraulic pressure isthought to be the goldstone in the procedure since it was quite helpful in both simple non-invasive elevation of the sinus membrane and as a diagnostic test for schneiderian membraneperforation.with miambe, the maximum gain in bone height was 10.6 mm which achieved the results obtained with the lateral window approach in a minimally invasive manner. the majority of the patients experienced mild pain after sinus floor elevation surgery and this was due to non-invasive nature of the procedure. the minor post-operative complications included infraorbital ecchymosis in one case 5.88%. this could be attributed to the injury of the posterior superior alveolar artery during sinus floor elevation surgery due to the anatomical variations of posterior superior alveolar artery location which could be located even in the floor of maxillary sinus. bleeding from the nose occurred in one case5.88%, which arise12 hours after surgery according to the patient description. it was mild and stopped without any intervention. as a conclusion, utilization of hydraulic pressure in combination with sinus balloon technique is of great value in both sinus j bagh college dentistry vol. 28(1), march 2016 an assessment of oral and maxillofacial surgery and periodontics 113 membrane elevation and as a diagnostic tool of schneiderian membrane perforation. the crestal sinus balloon techniqueproduce the same elevation achieved by lateral approach which is ≥10 mm in a less invasive manner. it solves the limitations for original transcrestal osteotome technique for cases even when the subantral bone height is less than 3 mm. also it reduces the risk of sinus membrane perforation and reduces the postoperative pain, infection, and other symptoms usuallyoccurred with sinus lift procedures. references 1. tatum oh. lecture presented to the alabama implant congress, 1976. 2. summers rb. a new concept in maxillary implant surgery: the osteotome technique.compendium 1994:15(2):152, 154-6. 3. toscano n, holtzclaw d, rosen p. the effect of piezoelectric use on open sinus lift perforation: a retrospective evaluation of 56 consecutively treated cases from private practices.j periodontol2010:81(1):167-71. 4. woo i, le bt. maxillary sinus floor elevation: review of anatomy and two tech niques.implant dent.2004:13(1):28-32. 5. solar p, geyerhofer u, traxler h, windisch a, ulm c, watzek g. blood supply to the maxillary sinus relevant to sinus floor elevation procedures. clin oral implants res 1999:10(1):34-44. 6. vercellotti t. technological characteristics and clinical indications of piezoelectric bone surgery. minerva stomatol 2004; 53(5): 207-14. 7. kim y, cho y, yun p.assessmentofdentists' subjective satisfaction witha n ewly developed device for maxillarysinus membrane e levation bythe crestal approach.j periodontal implant sci2013; 43(6):308-14. 8. baumann a, ewers r. minimally invasive sinus lift. limits and possibilities in the atrophic maxilla. mund kiefer gesichtschir1999:3(1):70–73. 9. zitzmann n, scharer p. sinus elevation procedures in the reabsorbed posterior maxilla. comparison of the crestal and lateral approaches. oral surg oral med oral pathol oral radiol endod 1998; 85:8-17. 10. stelzle f, benner ku. evaluation of different methods of indirect sinus floor elevation for elevation heights of 10mm: an experimental ex vivo study. clin implant dent relat res 2011;13:124–133. j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 51 the effectiveness of aluminum potassium sulfate microparticles addition into soft denture lining material on tensile strength and peel bond strength of soft denture lining material ali mohad b.d.s. (1) abdalbseet a fatalla b.d.s., m.sc., ph.d. (2) abstract naturally available products have been used widely for centuries in handling human disease. the present study aimed to determine the effect of aluminum potassium sulfate addition into the soft liner on tensile strength and peel bond strength. the effect of aluminum potassium sulfate evaluated by two methods, first one include incorporation of kal (so4)2 into soft liner monomer in concentration (2%,3% by wt.) while the second method include immersion of soft liner specimens in solution of kal(so4)2 in concentration(5%,10% percent) during time periods (0,10 minutes). in conclusions, the results of current study encourage use kal (so4)2 within soft liner material. keywords: aluminum potassium sulfate, micro-particles, denture lining material. (received: 15/6/2019; accepted: 29/7/2019) introduction soft denture lining material used in patient suffering from pain or soreness resulting from tissue contact with hard denture base. addition of soft denture lining material ensuring optimal adaptation of the denture to the underling tissue. (1) soft denture lining material characterized by high resiliency so acting as shock absorber reducing load transmission to the underling tissue. (2) using of soft liners with time becomes more prevalent for providing comfort for patient wearing denture. soft liners are frequently used for patients who cannot bear wearing a conventional denture base (3). aluminum potassium sulfate(alum) having chemical formula kal(so4).12h20 and generally having no odor , no color sold crystal that return white in color in air that used in food preservation and water purification. the alum has been recommended as active ingredient part in mouth wash by the counter advisory panel of u.s. food and drug administration (fdas) (4). 1. master student, department of prosthodontics, college of dentistry, university of baghdad. 2. assistant professor, department of prosthodontics, college of dentistry, university of baghdad. * corresponding e-mail: abdalbasit@codental.uobaghdad.edu.iq materials and methods the study divided into two parts: 1. incorporation of kal (so4)2 into soft liner (2%, 3% by wt.). where it mixed with soft liner monomer. 2. immersion of soft liner specimens in solution of kal (so4)2 (5%, 10%, for 10 minutes). in addition to control group. fifty specimens for each test were made, which then subdivided to five groups. specimen preparation: tensile strength specimens preparation: specimen was prepared, with central cross section area (33*6*3mm) (astm d412) (5). the lower portion of the flask was filled with dental stone that mixed according to the manufacturer's instructions (w/p ratio; 20ml/100g). the plastic patterns was invested into the stone mixture, after setting of the stone, the stone surface was coated with separating medium then the upper half of the flask was positioned on the top of the lower half and filled with stone. the flask was well covered and left for stone setting. after 1 hr the flask was opened and the standard specimen was drawn out (figure1). mailto:abdalbasit@codental.uobaghdad.edu.iq j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 52 figure1: mold preparation for tensile strength specimens peel bond strength specimen’s preparation: the preparation of the peel bond strength test specimens was made according to astm d90393. two rectangular stainless steel plates one includes holes with dimensions of 100 x 10 x 2 mm (length, width, height respectively) for pmma, and the other includes holes with dimensions 150 x 10 x 2 mm (length, width, height respectively) for soft liners (figure2). the flask consist of four plates two of them 5 mm in thickness were used as a cover while the others 2 mm in thickness contain holes inside them(6). figure2: prepared plates for peel bond strength specimens. proportioning and mixing of heat cure acrylic soft liner: the liquid mixed with powder according to manufacturer direction (p/ l ratio1.2g:1ml) in dry clean glass jar and covered with lid. incorporation of aluminum potassium sulfate into soft liner: the weighed amount of kal(so4)2 added to the soft liner monomer and mixed in clean dry glass jar using probe sonicator until become completely homogenous then soft liner powder added. keeping in mind to subtract the weight of kal (so4)2 from weight of soft liner powder. packing packing method for tensile specimens: when the soft liner reach to dough stage, it was placed on mold space prepared previously and secured with polyethylene sheet then upper part placed on it and transferred to the hydraulic press to expel the excess soft liner. then the flasks removed from press, opened then remove polyethylene sheet and excess soft liner. then the flask closed and transferred to hydraulic press for 5 minutes under pressure (100g/cm2) then clamping the flask (7). packing method for peel strength specimens: the first step in specimen preparation include packing of heat cure acrylic resin, this material was proportioned and mixed according to the manufacturer’s instructions, p/l ratio (2.3g/1ml) then inserted into the holes prepared for acrylic in the stainless steel plates (6).the flask was closed and placed under hydraulic press until reach (100 mpa) and left for 5 minutes (7). after that, the specimens were immersed in boiling water for 20 minutes. after polymerization, the flasks were kept for cooling for 30 min followed by cooling under running water for 15 minutes. the acrylic strips were deflasked and trimmed away. the surfaces of acrylic that bonded with soft liners were smoothed using 240-grit silicone carbide paper, cleaned, and dried. then the acrylic specimens were reflasked (6) (figure3). figure 3: acrylic specimens in flask. j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 53 part of the acrylic specimen surface of all specimens was covered with a piece of tinfoil to ensure that only 70mm length of the lining material was bonded (8) (figure4 ). figure 4: application of tinfoil on acrylic specimens. then the soft lining material mixed and inserted into the hollow space in the plate designed for soft liner (figure5). figure 5: packing of heat cure soft liner. this assembly was covered with another plate 5mm thick then the nuts were tightened. the flask was placed under hydraulic press with slow pressure to allow even flow of soft liner dough until reach (100mpa) and left for 5 minutes (7). curing and finishing: the packed dental flask immersed in digital water path. curing time was according to the manufacturer's instructions (70°c for 90 minutes then for 30minutes after temperature raising to 100°c) (9).when curing cycle completed, the flask removed and allow to cool for 30 minutes then flask opened and specimens removed from their mold .the access soft liner material removed using sharp blade and finished by fine grit polishing silicon bur and fine grit sand paper. evaluating the effect of aluminum potassium sulfate on tensile strength and peel bond strength of the soft-liner: tensile strength test procedure: thickness of the test specimens was measured at the center of the test specimen by a vernier caliper with digital readout. the width of the test specimens was also measured to calculate the cross sectional area of the narrow portion of the specimen. the specimen was mounted in a computerized universal testing machine in a way that exposes only the central area of specimens during testing (10). the upper member of the universal testing machine remained fixed, while the lower member moved at a constant rate of (500 mm/min) (11), every specimen was stretched until it cuts. the maximum force at break was then recorded by the computer software. in accordance with iso 37: 2011 the ultimate tensile strength was calculated from the maximum stretching force at break divided by the original cross sectional area of the narrow portion of the specimen (width × thickness). peel bond strength testing procedure: the peel bond strength test was analyzed according to astm d903-93 in a universal testing machine at an angle of 180º and speed of 152 mm/min. the non-relined portion of the heat-cured acrylic resin was clamped on the upper clutch of the equipment while the free portion of soft lining j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 54 material was folded and fixed in the lower clamp and holding the specimen against an alignment plate (figure 6). figure 6: peel bond specimen under testing. after the specimens were tested and removed from the testing device, the nature of the bonding failure was evaluated by naked eye, and categorized as cohesive, adhesive or mixed. cohesive failure refers to tearing within the soft liner material, adhesive failure refers to total separation at the interface between the soft liner and acrylic resin, and mixed failure refers to both(8). the peel bond strength was calculated by using the following equation: peel strength = average load / width of the sample (12). results scanning electron microscope (sem): sem results of soft liner before and after the addition of 2% and 3% by wt. kal(so4)2 micro particles powder( figure7). figure 7: scanning electron microscope results: control group(a,b), 2% group of kal(so4)2 (c,d), 3% group of kal(so4)2 (e,f). j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 55 test of homogeneity of variances before starting with anova table multiple comparisons test, the variances of tested groups within each test were analyzed by running the levene’s test of homogeneity. according to primary analysis of data homogeneity, gameshowell test was selected for multiple comparisons of incorporation part and boneferroni test was selected for multiple comparisons of immersion part of tensile strength and peel strength testes. tensile strength test experimental incorporation group 3% by wt. of kal (so4)2 showed highest mean value (6.2497 mpa) followed by the experimental group 10% (immersion in kal (so4)2 solution) with mean value (2.786 mpa) followed by incorporation group 2% with mean value (2.729 mpa) then the experimental immersion group 5% (2.293 mpa) mean value while the lowest mean value was for the control group where the mean value (2.113 mpa). one-way anova table for tensile strength test results showed significant difference between tested groups (table 1 and 2). table 1: one-way anova table of incorporation part. table 2: one-way anova table of immersion part. sum of squares df mean square f sig. between groups 2.428 2 1.214 3.853 0.034 within groups 8.508 27 0.315 total 10.936 29 to compare the mean values of tested groups, games howell test was conducted for incorporation groups, while bonfferoni was conducted for immersion groups. there was significant difference between groups except the difference between control group and 5% immersion group and between 5% immersion group and 10% immersion group were non significant (table 3 and 4). table 3: games howell multiple comparisons test of incorporation part results. table 4: bonfferoni multiple comparisons test of immersion part results. sum of squares df mean square f sig. between groups 99.624 2 49.812 85.849 0.000 within groups 15.666 27 0.580 total 115.290 29 mean difference (ij) p value sig. control 2% -0.61600* 0.034 s 3% -4.13670* 0.000 hs 2% 3% -3.52070* 0.000 hs mean difference (i-j) p value sig. control 5 % -0.18000 1.000 ns 10% -0.67300* 0.037 s 5 % 10% -0.49300 0.180 ns j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 56 peel bond strength test: the control group showed highest mean value (1.921 n/mm) followed by experimental immersion group 5% (1.847) mean value, followed by experimental immersion group 10% (1.459)mean value then the experimental incorporation group 2% (1.082) mean value while the lowest mean value was for 3% incorporation group (0.8387). upon examining the mode of failure of the specimens, it appeared that the specimens of control group failed cohesively. the experimental 0.05 immersion group, 7 specimens show both failures while the other failed cohesively. the experimental 10% immersion group, 8 specimens show both failures while one specimen failed cohesively and the other failed adhesively. in 2% incorporation group all the specimens failed cohesively except one show both failures while in 3% incorporation group 7 specimens show adhesive failure while the other show both failures. one-way anova table for peel strength test results showed highly significant difference between all tested groups (table 5 and 6). table 5: one-way anova table for peel strength test incorporation results. sum of squares df mean square f sig. between groups 6.448 2 3.224 65.427 0.000 within groups 1.331 27 0.049 total 7.779 29 table 6: one-way anova table for peel strength test immersion results. to compare the mean values among study groups, games howell test was conducted for incorporation groups, while bonfferoni was conducted for immersion groups. there was highly significant difference between all groups except the difference between control group and 5% immersion group which was non-significant. (table 7 and 8). table7: games howell multiple comparisons test of peel strength test incorporation results. incorporation groups mean difference (i-j) p value sig. control 2% 0.83900* 0.000 hs 3% 1.08230* 0.000 hs 2% 3% 0.24330* 0.000 hs table8: bonfferoni multiple comparisons test of peel strength test immersion results. immersion groups mean difference (i-j) p value sig. control 5 % 0.07400 1.000 ns 10% 0.46200* 0.004 hs 5% 10% 0.38800* 0.017 s sum of squares df mean square f sig. between groups 1.232 2 0.616 7.333 0.003 within groups 2.267 27 0.084 total 3.499 29 j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 57 discussion: soft lining materials play a major role in prosthetic dentistry, due to the viscoelastic properties of denture liners which reduce and redistribute the functional load over the denture bearing area (13). aluminum potassium sulfate is natural products have been used for centuries in treating human diseases and they contain components of therapeutic value. natural products are environmentally safer, easily available, and cheap (14). tensile strength test the maximum stress a material can withstand before being locally deformed is known as tensile strength (15). among the several preferable mechanical properties of soft lining material, high tensile strength is of great importance to final prosthesis (16). the result of this study revealed that significant increase in mean values of experimental groups by using concentration 0.02, 0.03 by wt.(incorporation to the soft liner) and 5%, 10% of kal(so4)2 solution(immersion of soft liner in the kal(so4)2 solution), however the highest increase was noticed in 3% by wt. kal(so4)2 microparticles concentration. the results were agreed with the results of waters and jagger in 1999. peel bond strength test peel bond strength is the average load per unit width of bond line required to separate bonded materials, when the angle of separation is 180° (12). the result of this study revealed that there was decrease in peel bond strength of experimental groups with various concentration (2%, 3% by wt. incorporation of kal (so4)2 to the soft liner and 5% immersion and 10% immersion groups of soft liner specimens in the kal (so4)2 solution) in comparison with control group, with highest value for control group and the lowest value for 3% by wt. incorporation group. the kal (so4)2/ polymer bonding have an influence on peel bond property, where stronger kal (so4)2/polymer bond increases the values of this property and vice versa (11). the experimental groups showed a tendency to fail adhesively in 20% of specimens (8 specimens of experimental groups) after the addition of the kal (so4)2 micro-particles, this may be related to the bonding surface swelling due to the absorption of water by the soft denture liner (because of hydrophilic nature of kal (so4)2) and stress may increase in the interface between soft denture liners and denture base acrylic resin leading to adhesive failure. in controversy, cohesive failure in control group was predominant, due to its poor tear resistance. in 47.5% of experimenta l specimen s sho w mixed fa ilu re (adhes ive and cohesive) th is may due to bonding surface swelling and/or decreasing in tear resistance of soft liner after kal(so4)2 addition. reduction in peel bond strength may be due to aggregation of kal (so4)2 micro-particles because of higher surface energy and this aggregation can cause micro fracture that weaken the polymer structure. references 1 aydin ak, terzioglu h, akinary ae, ulubayram k, hasirei n. bond strength and failure analysis of lining materials to denture resin. dent mater. 1999;15(3):211-21. 2 bulad k, taylor rl, verran j, mccord jf. colonization and penetration of denture soft lining materials by candida albicans. dent mater. 2004;20(2):167-175. 3 sarac d, sarac ys, kurt m, yuzbasioglu e. the effectiveness of denture cleansers on soft liners colored by food colorant solutions. j prosthodont. 2007; 16(3):185-191. 4 olmez a, can h, ayhan h, olur h. effect of alumcontaining mouthrins in children for plaque and salivary levels of selected oral microflora. j. clin. pediat. dent. 1998;22:335-341. 5 dootz er, koran a, craig rg. comparison of the physical properties of 11 soft denture liners. j prosthet dent.1992; 67:707-712. 6 sanchez-aliaga as, pellissari cv, arrais ca et al. peel bond strength of soft lining materials with antifungal to a denture base acrylic resin. dental mater j. 2016;35(2):194–203. 7 yassir ad. the effect of addition of zirconium nano particle on antifungal activity and some properties of soft denture lining material. journal of baghdad collage of dentistry. 2017; 29(4):27-32. 8 demir h, dogan a, dogan om, keskin s, bolayir g, soygun k. peel bond strength of two silicone soft liners to a heat-cured denture base resin. j adhesive dent. 2011;13(6):579-584. 9 issa mi. evaluating the effect of silver nanoparticles incorporation on antifungal action and some properties of soft denture lining material. journal of baghdad collage of dentistry. 2015; 27(2):17-23. 10 urban vm, de souza rf, arrais ca, borsato kt,vaz lg. effect of the association of nystatin with a tissue conditioner on its ultimate tensile strength. j prosthodont. 2006;15: 295-299 11 waters mg, jagger rg. mechanical properties of an experimental denture soft lining material. j dent. 1999; 27: 197-202 j bagh college dentistry vol. 31(4), december 2019 the effectiveness of 58 12 kutay o. comparison of tensile and peel bond strengths of resilient liners. j prosthet dent. 1994; 71: 526-530. 13 pinto jr, mesquita mf, henriques ge, de arruda nma. effect of thermocyclining on bond strength and elasticity of 4 long term soft denture liners. j prosthet dent. 2002;88: 516521. 14 osuala fi, ibidapo obe mt, okoh hi, aina oo, igbasi ut, nshiogu me .evaluation of the efficacy and safety of potassium aluminium tetraoxosuiphate in the treatment of tuberculosis. european j of biol sci. 2009; 1:10-14. 15 sakaguchi rl, powers jm. craig's restorative dental materials-e-book, elsevier health sciences. 2012. 16 oguz s, mutluay mm, dogan om, et al. effect of thermocycling on tensile strength and tear resistance of four soft denture liners. dent mater j. 2007; 26: 296-302. الخالصة: والبوتاسيوم الى مادة الطقم المواد المتوفرة طبيعياً استخدمت لقرون في عالج امراض االنسان. الهدف من الدراسة الحالية هو لتحديد تأثير اضافة كبريتات االلمنيوم طريقتين، الطريقة األولى تتضمن دمج كبريتات االلمنيوم المرنة على قوة السحب وقوة ترابط التقشير. تأثير إضافة كبريتات االلمنيوم والبوتاسيوم قد تم تقيمهُ من خالل % بالوزن( بينما الطريقة الثانية تتضمن غمس عينات مادة الطقم المرنة في محلول كبريتات االلمنيوم 3%, 2والبوتاسيوم مع سائل مادة الطقم المرنة في تركيز ) ائق(. في االستنتاج، نتائج الدراسة الحالية تشجع استخدام كبريتات االلمنيوم والبوتاسيوم مع مادة دق 10, 0%( خالل فترة زمنية )10% , 5والبوتاسيوم بتركيز ) الطقم المرنة. journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 28 research article clinicopathological assessment of chronic hyperplastic candidasis hussain sadiq hussain1*, ban f. al-drobie2 1 master student, oral surgery unit, al-maghrib specialized dental health center, baghdad health directorate-al-rusafa, ministry of health 2 assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. *corresponding author, mk94ch@gmail.com abstract: background: chronic hyperplastic candidiasis is the least common type of oral candidiasis. the diagnosis, long-term treatment, and prognosis of this potentially malignant oral condition are still currently unclear. objective: the aim of this study is to analyze the demographic features and clinical characteristics of oral chronic hyperplastic candidiasis. materials and methods: a retrospective analysis was performed on blocks and case sheets of patients who were diagnosed with chronic hyperplastic candidiasis in the archives of oral and maxillofacial pathology at the college of dentistry/university of baghdad. demographic and clinical characteristics were analyzed. results: twenty-one cases with chronic hyperplastic candidiasis were collected and reviewed. buccal mucosa was the most affected sites. regarding the clinical features, lesions color frequently presented as white plaque. regarding clinical diagnosis, leukoplakia was noted the highest one among other previous diagnosis. conclusions: older adults are the mostly affected age group by chronic hyperplastic candidiasis with slight male predilection. white plaque is the most presented clinical feature with buccal mucosa being the most affected oral site. keywords: chronic hyperplastic candidiasis, clinicopathological features introduction oral candidiasis, also known as oral candidosis (oc), is the most prevalent fungal infectious illness of the oral mucosa, caused mostly by candida spp., an opportunistic pathogen. oc is divided into three types according on the clinical manifestations: pseudomembranous candidiasis, erythematous candidiasis, and chronic hyperplastic candidiasis (chc)(1,2). chc is a rare kind of oc, affecting mostly middle-aged smokers and having an incidence of around 1.61 percent in oc patients(3). due to the rarity of chc, there have been no significant sample size studies to date. chronic hyperplastic candidiasis is of special importance because of the difficulty in distinguishing between the many types of candidiasis and, more significantly, the risk of malignant transformation. it presents clinically as thick white plaques, erythematous lesions, or mixed red and heterogeneous white plaques, resembling and frequently misdiagnosing illnesses that appear as white lesions like lichen planus and leukoplakia(4). as a result, diagnosing chc can be challenging and time-consuming. aside from clinical signs, the sensitivity of laboratory testing such as exfoliative cytology and fungal culture in establishing the diagnosis is quite low. the diagnosis must be based on histopathology in order to rule out dysplasia or malignant conditions(5). the incidence of epithelial dysplasia in chc has previously been reported to be as high as 15%(6). some lesions in chc patients may develop to varying degrees of epithelial dysplasia and potentially malignant transformation to oral squamous cell carcinoma (oscc) if they are not treated immediately and properly. malignant transformation has been predicted to occur in as many as 10% of untreated chc patients(7). chc diagnosis, long-term treatment, and prognosis remain difficult to come by. received: date: 05-03-2022 accepted: date: 10-04-2022 published: date: 15-12-2022 copyright: © 2022 by the authoruthors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/li censes/by/4.0/). https://doi.org/10.26477 /jbcd.v34i4.3274 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3089 https://doi.org/10.26477/jbcd.v34i1.3089 j. bagh. coll. dent. vol. 34, no. 4. 2022 hussain and al-drobie 29 figure 1: distribution of patients by gender figure 2: distribution of patients by age there are just a few studies on chc in the literature, therapy in recent years, as well as clinical and histological aspects chc's efficacy and long-term follow-up are still being investigated. the aim of this study is to assess the demographical and clinicopathological features that affecting chc. materials and methods study design and ethics approval this retrospective study design was conducted at the department of oral and maxillofacial pathology at the college of dentistry, university of baghdad. the research ethics committee of the college of dentistry, university of baghdad has reviewed and approved this study (no. 283721). study population the researcher looked at the patients' healthcare records from different hospitals. cases were collected from college of dentistry laboratory, university of baghdad. patients having a confirmed chc diagnosis were gathered and analyzed. data collection and follow-up demographic data of the patients (gender, age, smoking, systemic disease) mycological information including clinical information, characteristics of lesions (site, type, size and clinicopathological parameters) were collected. statistical analysis data were expressed as a mean ± standard deviation and assessed by using chi square test. differences were considered significant at * = p < 0.05, ** = p < 0.01, *** = p < 0.001. statistical analyses were conducted using graphpad prism software version 7.0. results demographic characteristics a total of 21 cases with 12 (57%) males and 9 (43%) females, with a definitive diagnosis of chc were reviewed and presented in figure 1. the age range was from 18 to 75 years, with a mean of 52.33 years and standard deviation (sd) of ± 13.7. the highest proportion was between 50 -68 years, figure 2. a total of 11 of 21 patients had a history of smoking figure 3. furthermore, over 70 % of patients who had chc had systemic disease as revealed in (fig. 4). j. bagh. coll. dent. vol. 34, no. 4. 2022 hussain and al-drobie 30 figure 3: distribution of patients according to smoking site 4.76% 4.76% 71.4°% figure 4: distribution of patients by systemic disease clinical features figure 5 revealed buccal mucosa was the most affected sites (no.=15, %=71.4) while the remaining sites constitutes only one case for each site (4.76%). regarding the clinical features, lesions color frequently presented as white plaque (n=17), the size of biopsy varied from 0.5 cm to 3 cm with a mean of 1.3cm. collected data showed that the duration was variable and ranged from 2 months up to 14 years. oral manifestations of chc, leukoplakia lp (52.38%) was noted the highest one among other diagnosis are shown in table 1. discussion age was not significant risk factor for chc that caused by candida infection, likewise in other previous study showed that the age has no bearing on the transformation of oral leukoplakia(8). in contrast with other study that showed elderly were susceptible to candida infection and in oral leukoplakia proposed that age has a role in candida infection(9). few research has looked at gender differences in a broad group of people. both the female and male subgroups in this study showed the same trend of rising oral candida infection rates. furthermore, in all age grouping, not surprisingly, the preponderance of the male had higher overall infection rates than females (10). ant. part of tongue buccal mucosa 4.76% 4.76% cheek mucosa commissure of mouth dorsal surface of tongue left and right buccal mucosa right max. gingiva figure 5: site of involvement of chc by clinical information j. bagh. coll. dent. vol. 34, no. 4. 2022 hussain and al-drobie 31 table 1: distribution of study sample according to clinicopathological parameters variable frequency percentage size <1cm 3 14.29 1-3cm 18 85.71 biopsy excisional 15 71.43 incisional 6 28.57 <1 14 66.67 duration (years) 1-3 3 14.29 4-6 2 9.52 >7 2 9.52 red 1 4.76 color lesion white 17 80.95 whitish pink 2 9.52 yellowish 1 4.76 carcinoma 1 4.76 chc 1 4.76 diagnosis fibroma 1 4.76 hyperkeratosis 6 28.57 leukoplakia 11 52.38 pyogenic granuloma 1 4.76 in conclusion, male patients are more sensitive to oral candidiasis than female patients, and advanced age may be a risk factor for oral candidiasis, presumably due to complicated systemic diseases. for the systemic diseases and smoking, our results concluded that over 70 % of patients who had chc had systemic disease. oral candidiasis is common in people who have a variety of systemic disorders. immune dysfunction is the most common cause of oral candidiasis. candidiasis can occur at any age in people with immunodeficiency syndromes who have an underlying defect in their capacity to remove any fungal attachment to the oral mucosa (11). candida albicans' dimorphic nature allows the organism to convert from a commensal to pathogenic state mostly through the production of biofilms when host defenses are reduced due to systemic diseases(12). for other factor, smoking, the results showed that the incidence of smokers in chronic hyperplastic candidiasis were high but not significant. although it is unclear if smoking accelerates the development of cancer from oral leukoplakia, there is considerable evidence of a link between smoking and the development of chc. according to other research, nonsmokers had an increased risk of malignant transformation of oral leukoplakia(13). most histopathologist consider incisional biopsy as a reliable method of determining the nature of oral leukoplakic lesions. results of the present study showed incisional biopsy seemed to occur only in 28.5% (6/21) and 71.5% (15/21) of cases in the excisional biopsy group. excisional biopsy is hypothetically preferable since j. bagh. coll. dent. vol. 34, no. 4. 2022 hussain and al-drobie 32 the entire clinically abnormal area were examined histopathologically. regarding provisional diagnosis, leukoplakia was significantly pointed the highest one among other diagnosis. to validate the provisional diagnosis given during a clinical oral examination, many specialized tests are necessary. leukoplakia is a condition that is best defined as a white plaque that can appear on any mucosal surface and cannot be removed (14). in this study, results showed that the predominant lesion color was white, over 80% of lesions were white in color. on average, roughly 5% of oral leukoplakia will develop into cancer. with observation periods ranging from 1 to 30 years, the reported incidence of malignant transformation of oral leukoplakia ranges from 13 percent to 34 percent (15). conflict of interest: none declared. source of funding: self-funded. references 1. krishnan, p. a. (2012). fungal infections of the oral mucosa. indian journal of dental research, 23(5), 650. 2. hellstein, j. w., and marek, c. l. (2019). candidiasis: red and white manifestations in the oral cavity. head and neck pathology, 13(1), 25-32 3. hu, l., zhou, p., zhao, w., hua, h., & yan, z. (2020). fluorescence staining vs. routine koh smear for rapid diagnosis of oral candidiasis—a diagnostic test. oral diseases, 26(5), 941-947. 4. shah, n., ray, j. g., kundu, s., & sardana, d. (2017). surgical management of chronic hyperplastic candidiasis refractory to systemic antifungal treatment. journal of laboratory physicians, 9(02), 136-139. 5. telles, d. r., karki, n., & marshall, m. w. (2017). oral fungal infections: diagnosis and management. dental clinics, 61(2), 319-349. 6. sitheeque, m., & samaranayake, l. (2003). chronic hyperplastic candidosis/candidiasis (candidal leukoplakia). critical reviews in oral biology & medicine, 14(4), 253-267. 7. bartie, k. l., williams, d. w., wilson, m., potts, a. j. c., & lewis, m. a. o. (2004). differential invasion of candida albicans isolates in an in vitro model of oral candidosis. oral microbiology and immunology, 19(5), 293-296. 8. holmstrup, p., vedtofte, p., reibel, j., & stoltze, k. (2006). long-term treatment outcome of oral premalignant lesions. oral oncology, 42(5), 461-474. 9. akpan, a., & morgan, r. (2002). oral candidiasis. postgraduate medical journal, 78(922), 455-459. 10. sharma, a. (2019). oral candidiasis: an opportunistic infection: a review. int j applied dent sci, 5(1), 23-27 11. kim, j., and sudbery, p. (2011). candida albicans, a major human fungal pathogen. the journal of microbiology, 49(2), 171177 12. lott, t. j., fundyga, r. e., kuykendall, r. j., and arnold, j. (2005). the human commensal yeast, candida albicans, has an ancient origin. fungal genetics and biology, 42(5), 444-451 13. oliver, d. t., & shillitoe, e. (1984). effects of smoking on the prevalence and intraoral distribution of candida albicans. journal of oral pathology & medicine, 13(3), 265270. 14. warnakulasuriya, s., johnson, n. w., & van der waal, i. (2007). nomenclature and classification of potentially malignant disorders of the oral mucosa. journal of oral pathology & medicine, 36(10), 575-580. 15. warnakulasuriya, s., & ariyawardana, a. (2016). malignant transformation of oral leukoplakia: a systematic review of observational studies. journal of oral pathology & medicine, 45(3 j. bagh. coll. dent. vol. 34, no. 4. 2022 hussain and al-drobie 33 العنوان: التقييم السريري المرضي لفرط التنسج المزمن , بان فاضل الدروبي الباحثون: حسين صادق حسين : صالمستخل يص الخلفية: داء المبيضات المفرط التنسج المزمن هو أقل أنواع داء المبيضات الفموي شيوًعا. ال يزال التشخيص والعالج طويل األمد والتشخ لداء السريرية والخصائص الديموغرافية السمات تحليل هو الدراسة هذه من الهدف الهدف: حاليًا. واضحة غير الخبيثة الفموية الحالة لهذه لمبيضات الفموي المزمن المفرط التنسج. المواد والطرق: تم إجراء تحليل بأثر رجعي على كتل وأوراق حالة لمرضى تم تشخيص إصابتهم بداء ا فية المبيضات المفرط التنسج المزمن في أرشيف أمراض الفم والوجه والفكين في كلية طب األسنان / جامعة بغداد. تم تحليل الخصائص الديموغرا حالة مصابة بداء المبيضات مفرط التنسج المزمن. كان الغشاء المخاطي الشدق هو األكثر تضررا. فيما 21لسريرية. النتائج: تم جمع ومراجعة وا هي الطالوة أن لوحظ ، السريري بالتشخيص يتعلق فيما بيضاء. لوحة شكل على متكرر بشكل اآلفات لون يظهر ، السريرية بالسمات يتعلق بين التشخيصات السابقة األخرى. األعلى هي ميل طفيف للذكور. اللويحة البيضاء مع مفرط التنسج المزمن بداء المبيضات هم الفئة العمرية األكثر إصابة كبار السن أكثر االستنتاجات: السمات السريرية ظهوًرا مع كون الغشاء المخاطي الشدق هو الموقع الفموي األكثر تضرًرا. maha f.docx j bagh college dentistry vol. 28(2), june 2016 the systemic host oral and maxillofacial surgery and periodontics 79 the systemic host modulation therapy of periodontal diseases hasanain h. shakir, b.d.s. (1) maha a. aziz, b.d.s., m.sc. (2) abstract background: the systemic host modulation therapy is new approach in treatment of periodontal diseases. materials and methods:the target of this treatment is the host response to microbial infection because at present time,it is well known that most of damage found in periodontal diseases cause by the inflammatory -immune response to periodontal infections.sub-antimicrobial-dose doxycycline (sdd) is a 20-mg dose of doxycycline (periostat) that is approved and indicated as an adjunct to scaling and root planning (srp) in the treatment of chronic periodontitis. results:at present, sdd (periostat) is the only systemically administered agent that is approved by the u.s. food and drug administration (fda) and accepted by the american dental association (ada). keywords: periostat. (j bagh coll dentistry 2016; 28(2):79-83). introduction host modulation is a relatively new term that has been incorporated into our dental jargon, but it has not been well defined. host can be defined as “the organism from which a parasite obtains its nourishment,” or in the transplantation of tissue, “the individual who receives the graft.” modulation is defined as “the alteration of function or status of something in response to a stimulus or an altered chemical or physical environment” (taber’s medical dictionary, 2004). in diseases of the periodontium that are initiated by bacteria, the “host” clearly is the individual who harbors these pathogens; however, it was not clear for many years whether it was possible to modulate the host response to these pathogens and other stimuli leading to the breakdown of the attachment apparatus. host modulation with chemotherapeutic agents or drugs is the latest adjunctivetherapeutic option for themanagement of periodontal diseases.the concept of host modulation is fairly new to the field of dentistry but is universally understood by most physicians who routinely apply the principles of host modulation to the management of a number of chronic progressive disorders such as arthritis and osteoporosis. until relatively recently, treatment options for periodontal disease have focused solely on reducing the bacterial challenge by nonsurgical therapy, surgery, and systemic or local antimicrobial therapy. although bacteria are necessary for disease initiation, they are not sufficient to cause disease progression unless there is an associated inflammatory response within a susceptible host (1). (1) highdiploma student. department of periodontics. college of dentistry. university of baghdad. (2)assistant professor. department of periodontics. college of dentistry. university of baghdad. the development of sdd as an hmt, driven by research into the pathogenesis of periodontal disease, is a great example of how translational research can lead to new treatments. by better understanding the biochemical processes that are important in periodontal disease, a pharmacologic principle (doxycycline downregulates mmp activity) has been used in the development of a new drug treatment. data presented from research studies show the clinical benefits of adjunctive sdd, and the science behind sdd has been transferred into clinical practice. in other words, dentists now have the opportunity to use sdd for patient care, with the aim being to enhance the treatment response to conventional therapy. agents used for systemic host modulation therapy the potential adjunctive therapeutic agents that can reduce the destruction of periodontium in periodontal diseases are the non-steroidal antiinflammatory drugs,bisphosphonates and subantimicrobial dose of doxycycline (figure 2). 1) non-steroidal anti-inflammatory drugs (nsa ids) the nsaids inhibit the formation of prostaglandins, including pge2, which is produced by neutrophils, macrophages,fibroblasts and gingival epithelial cells in response to the presence of lipopolysaccharide(lps), a component of the cell wall of gram negative bacteria. pge2 has been extensively studied in periodontal disease because it upregulates bone resorption by osteoclasts (3).however, nsaids have some serious disadvantages when considered for use as a hmt for periodontitis. daily administration for extended periods is necessary for periodontal benefits to become apparent, and nsaids are associated with significant side effects, including gastrointestinal problems, j bagh college dentistry vol. 28(2), june 2016 the systemic host oral and maxillofacial surgery and periodontics 80 hemorrhage (4),and renal and hepatic impairment. furthermore, research shows that the periodontal benefits of taking long-term nsaids are lost when patients stop taking the drugs, with a return to or even an acceleration of the rate of bone loss seen before nsaid therapy, often referred to as a “rebound effect" (5) . for these reasons, the longterm use of nsaids as an adjunctive treatment for periodontitis has never really developed beyond research studies. 2)bisphosphonates bisphosphonates are a class of drugs that prevent the loss of bone mass, used to treat osteoporosis and similar diseases. they are the most commonly prescribed drugs used to treat osteoporosis. adverse effects oral bisphosphonates can cause upset stomach and inflammation and erosions of the esophagus, which is the main problem of oral n -containing preparations. bisphosphonates, when administered intravenously for the treatment of cancer, have been associated with osteonecrosis of the jaw (onj)(6). a study had reported bisphosphonate use (specifically zoledronate and alendronate) as a risk factor for atrial fibrillation in women (7). in europe and north america, the incidence of oesophageal cancer at age 60–79 is typically 1 per 1000 population over five years, and this is estimated to increase to about 2 per 1000 with five years' use of oral bisphosphonates (8). 3)sub-antimicrobial-dose doxycycline(sdd) sub-antimicrobial-dose doxycycline (sdd) is a 20-mg dose of doxycycline (periostat) that is approved and indicated as an adjunct to scaling and root planning (srp) in the treatment of chronic periodontitis. it is taken twice daily for 3 months, up to a maximum of 9 months of continuous dosing. the 20-mg dose exerts its therapeutic effect by enzyme, cytokine, and osteoclast inhibition rather than by any antibiotic effect. at present, sdd (periostat) is the only systemically administered hmt specifically indicated for the treatment of chronic periodontitis that is approved by the u.s. food and drug administration (fda) and accepted by the american dental association (ada). a-mechanisms of action in addition to its antibiotic properties, doxycycline (as well as the other members of the tetracycline family) has the ability to downregulate mmps, a family of zinc-dependent enzymes that are capable of degrading extracellular matrix molecules, including collagen (table 1) (9). mmps are secreted by the major cell types in the periodontal tissues (fibroblasts,keratinocytes, macrophages, polymorphonuclear leukocytes (pmns), endothelial cells) and play a key role in periodontitis. excessive quantities of mmps are released in inflamed periodontal tissues, resulting in breakdown of the connective tissue matrix. the predominant mmps in periodontitis, particularly mmp-8 and mmp-9, derive from pmns and are extremely effective in degrading type i collagen, the most abundant collagen type in gingiva and periodontal ligament. the release of large quantities of mmps in the periodontium leads to significant anatomic disruption and breakdown of the connective tissues, contributing to the clinical signs of periodontitis (10). table1: the mechanisms by which doxycycline inhibits connective tissue breakdown.downregulation of destructive events occurring in the periodontal tissues by doxycycline results from modulation of a variety of different proinflammatory pathways (11). -inhibition of production of epithelial drived mmps. -direct inhibition of active mmps by cation chelation -inhibition of oxidative activation of latent mmps. -down regulates expression of key inflammatory cytokines including interleukin 1(il1), interleukin6(il6), and tumour necrosis factor alpha as well as pge2. -scavenge and inhibits production of reactive oxygen species(ros) produced by pmns(e.g,hoci which activate latent mmps). -stimulate fibroblast collagen production. -reduce osteoclast activity. -block osteoclast mmps. -stimulate osteoblast activity. b-clinical research data on distinct patient populations in a study, 3-month regimen of sdd produced a prolonged drug effect without a rebound in collagenase levels to baseline during the notreatment phase of the study(12). the mean levels of gingival crevicular fluid (gcf) collagenase were significantly reduced (47.3% from baseline levels) in the sdd group versus the placebo group, who received scaling and prophylaxis alone (29.1% reduction from baseline levels). accompanying these reductions in collagenase levels were gains in the relative attachment levels in the sdd group. continuous drug therapy over j bagh college dentistry vol. 28(2), june 2016 the systemic host oral and maxillofacial surgery and periodontics 81 several months appears to be necessary for maintaining collagenase levels near normal over prolonged periods. however, it is reasonable to speculate that levels of these mmps will eventually increase again in the more susceptible patients, and those individuals having the most risk factors and the greatest microbial challenge will require more frequent hmt than other patients. (mmp levels measure by densitometric units). (gcfcarboxylterminalpeptideafragment of type1 collagen measure by pg ictp/site). f i g u r e 1 : effect of sub-antimicrobial-dose doxycycline (sdd) on gingival crevicularfluid (gcf) collagenase (mmp-8, mmp-13) and ictp. a two-month regimen of sdd significantly decreased levels of matrix metalloproteinases (mmp-8 and mmp-13, neutrophil and bone-type collagenases, respectively) and ictp compared with placebo in gcf samples of chronic periodontitis patients(13). c-high risk patients a meta-analysis of randomized clinical trial of sdd used as an adjunct to srp revealed a benefit when using sdd in smokers with periodontitis (14). the responses of the smokers who received sdd and the nonsmokers who received placebo were intermediate to the two extremes and were broadly identical.improving on the clinical measurements of periodontitis (15); sdd significantly reduced the progression of periodontal attachment loss and the severity of gingival inflammation and alveolar bone loss in postmenopausal osteopenic women. d-combining sdd with periodontal surgery or local delivery systems however, emerging data in which sdd was used as an adjunct to access flap surgery in 24 patients revealed better probing depth reductions in surgically treated sites greater than 6mm compared with surgically treated sites in patients given placebo (16). furthermore, the sdd group demonstrated greater reductions in ictp (carboxy-terminal peptide, a breakdown product of collagen) than the placebo group, indicating that collagenolytic activity was reduced in the patients taking sdd. preliminary results from a 6-months, 180patient clinical trial designed to evaluate the safety and efficacy of sdd combined with a locally applied antimicrobial (doxycycline hyclate [atridox]) and srp versus srp alone demonstrated that patients receiving the combination of treatments experienced more than a 2-mm improvement in mean attachment gains and probing depth reductions (p < 0.0001) compared with srp alone (17). e-susceptible patient populations much interest has focused on genetic susceptibility to periodontal disease, particularly whether a specific variation in the genes that regulate the cytokine il-1 confers increased susceptibility to disease. this polymorphism is known as the periodontitis-associated genotype (pag), when the genotype-positive patients received sdd and specific biochemical markers were monitored at 2 and 4 months, a significant decrease (50% to 61%) in the il1β and mmp-9 levels was noted after treatment with sdd. correspondingly, gains in clinical attachment level and reduced probing depths were also observed (18). 0 50 100 150 200 250 300 b as e lin e 1 m on th 2 m on th ic t p le ve l placepo periostat 0 100 200 300 400 500 600 700 800 900 1000 m m p le ve l mmp-8 mmp-13 j bagh college dentistry vol. 28(2), june 2016 the systemic host oral and maxillofacial surgery and periodontics 82 f-side effects doxycycline at antibiotic doses (≥100 mg) is associated with adverse effects, including photosensitivity, hypersensitivity reactions, nausea, vomiting, and esophageal irritation. however, in the clinical trials of sdd (20-mg dose), it was reported that the drug was well tolerated, and the profile of unwanted effects was virtually identical in the sdd and placebo groups(19). no evidence of developing antibiotic resistance of the microflora after 2 years of continuous use (20). i-sequencing prescription with periodontal treatment the sdd is indicated as an adjunct to mechanical periodontal therapy and should not be used as a stand-alone or monotherapy. sdd should be prescribed to coincide with the first round of srp and is prescribed for 3 months, up to a maximum of 9 to 24 months of continuous dosing depending on the patient risk (21). host modulation factors in systemic disorders: in fact, it was suggested that tetracyclines could reduce the incidence of acute myocardial infarction (22) by blocking collagenase and stabilizing the collagen cap on the atheroscleromatous arterial plaques. other study have shown that sdd reduces systemic inflammatory biomarkers in cardiovascular diseased patients(23) and sdd decreases glycosylated hemoglobin (hba1c) assay in patients who are taking normally prescribed hypoglycemic agents. conclusions sdd is the only systemically administered hmt currently approved and indicated as an adjunct to srp for treating periodontitis. clinical trials have demonstrated a clear treatment benefit when using sdd versus srp alone. sdd should be used as part of a comprehensive treatment strategy that includes antibacterial treatments (srp, plaque control, oral hygiene instruction, local antimicrobials, and periodontal surgery), host response modulation (sdd), and assessment and management of periodontal risk factors. in the future, a range of hmts targeting different aspects of the destructive cascade of breakdown events in the periodontal tissues are likely to be developed as adjunctive treatments for periodontitis. the further development of these agents will permit dentists to treat specific aspects of the underlying biochemical basis for periodontal disease. references 1kazem nm, mahmood ms.assessment of seruminterleukin-1β and its correlation with periodontal healthstatusduring pregnancy.j baghcoll dentistry 2014; 26(2): 111-5. 2bhatavadekar nb, williams rc. new directions in host modulation for the management of periodontal disease. j clinperiodontol2009; 36 (2):124. 3offenbacher s, heasman pa, collins jg. modulation of host pge2 secretion as a determinant of periodontal disease expression. j periodontol 1993 ;64:432 4williams rc, jeffcoat mk, howell th, et al. altering the progression of human alveolar bone loss with the non-steroidal anti-inflammatory drug flurbiprofen. j periodontol1989;60:485. 5williams rc, jeffcoat mk, howell th, et al. three year trial of flurbiprofen treatment in humans: posttreatment period. j dent res 1991; 70:468. 6woo s, hellstein j, kalmar j. narrative review: bisphosphonates and osteonecrosis of the jaws. ann intern med 2006;144 (10): 753–61. 7heckbert sr, li g, cummings sr, smith nl, psaty bm. use of alendronate and risk of incident atrial fibrillation in women. arch intern med 2008; 168 (8): 826–31. 8green j,czanner g, reeves g, watson j, wise l,beral v.oral bisphosphonates and risk of cancer of oesophagus, stomach, and colorectum: case-control analysis within a uk primary care cohort. bmj 2010; 341. 9birkedal-hansen h. role of matrix metalloproteinases in human periodontal diseases. j periodontal 1993; 64:474 . 10nagase h. zinc metalloproteases in health and disease, 1997. pp.153–204. 11golub lm, mcnamara tf, ryan me, et al. adjunctive treatment with subantimicrobial doses of doxycycline: effects on gingival fluid collagenase activity and attachment loss in adult periodontitis. j clinperiodontol 2001;28:146 . 12ashley ra. clinical trials of a matrix metalloproteinase inhibitor in human periodontal disease. sdd clinical research team. ann ny acadsci1999; 878:335. 13golub lm, lee hm, greenwald ra, et al. a matrix metalloproteinase inhibitor reduces bone-type collagen degradation fragments and specific collagenases in gingival crevicular fluid during adult periodontitis. inflamm res 1997; 46:310 14needleman i, suvan j, gilthorpe ms, et al. a randomized -controlled trial of low-dose doxycycline for periodontitis in smokers. j clinperiodontol 2007; 34(4):325. 15golublm,leehm,stoner ja, et al. subantimicrobialdose doxycycline modulates gingival crevicular fluid biomarkers of periodontitis in postmenopausal osteopenic women.j periodontol2008;79 (8):1409. 16gapski r, barrjl, sarment dp, et al. effect of systemic matrix metalloproteinaseinhibition on periodontal wound repair: a proof of concept trial. j periodontol 2004; 75:441. 17novak mj, dawson dr, magnusson i, et al. combininghost modulation and topical antimicrobial therapy in the management of moderate to severe periodontitis: a randomized multicenter trial. j periodontol2008; 79(1):33. j bagh college dentistry vol. 28(2), june 2016 the systemic host oral and maxillofacial surgery and periodontics 83 18ryan me, lee hm, bookbinder mk, et al.: treatment of genetically susceptible patients with a subantimicrobial dose of doxycycline. j dent res2000; 79:608. 19preshaw pm, hefti af, novak mj, et al. subantimicrobial dose doxycycline enhances the efficacy of scaling and root planing in chronic periodontitis: a multi-center trial. j periodontol2004;75:1068. 20thomas j, walker c, bradshaw m. long-term use of subantimicrobial dose doxycycline does not lead to changes in antimicrobial susceptibility. j periodontol2000;71:1472. 21emingil g, atilla g, sorsa t, et al. the effect of adjunctive low-dose doxycycline therapy on clinical parameters and gingival crevicular fluid matrix metalloproteinase-8 levels in chronic periodontitis. j periodontol2004; 75:106. 22meiercr,derbyle,jick ss, et al. antibiotics and risk of subsequent first-time acute myocardial infarction. jama 1999;281:427. 23brown dl, desai kk, vakili ba, et al. clinical and biochemical results of the metalloproteinase inhibition with subantimicrobial doses of doxycycline to prevent acute coronary syndromes (midas) pilot trial. arteriosclerthrombvascbiol2004; 24(4):733. f i g u r e 2 : potential adjunctive therapeutic approaches .possible adjunctive therapies and points of intervention in the treatment of periodontitis are presented related to the pathologic cascade of events . cal , clinical attachment loss(2) wesal f.doc j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry160 effect of small cardamom extracts on mutans streptococci in comparison to chlorhexidine gluconate and de-ionized water (in vitro study ) ghada a. ibrahim, b.d.s. (1) wesal a. al – obaidi, b.d.s., m. sc. (2) abstract background: herbs are being widely explored to discover alternatives to synthetic antibacterial agents.small cardamom often referred to as queen of spices because of its very pleasant aroma and taste, have a history as old as human race. most people use cardamom as a spice and are largely unaware of its numerous health benefits. the purpose of this study was to evaluate the effect of different concentrations of water and alcoholic cardamom extracts on sensitivities, growth, and adherence of mutans streptococci in vitro. materials and methods: in this study, saliva was collected from ten volunteers (college students 18-22 years). agar well technique was used to study the sensitivities of mutans streptococci to different concentrations of small cardamom extracts and other control agents, also the effects of small cardamom extracts on viable counts, adherence of mutans streptococci were studied results: according to agar well diffusion methods, both cardamom extracts were effective in inhibition of mutans streptococci, but still weaker than chlorhexidine gluconate 0.2%. alcoholic extracts showed higher zone of inhibition compared to the same concentration of water with high significance differences (p<0.01). the effects of 10%, 15%, and 20% of both water and alcohol extracts of small cardamom were tested on the viability counts of mutans streptococci in vitro. highly significant reduction in the counts of bacteria was reported of both cardamom extracts and chx in comparison to control without agents after 24 hr. both cardamom extracts less effective than chx. all the concentration of water and alcohol cardamom mouth washes tested was not effective in prevention the adherence of bacteria on teeth surface in vitro, while chx was effective in prevention the adherence of bacteria. conclusion: cardamom extracts were effective against mutans streptococci, but still less than chx. keyword: mutans streptococci, small cardamom, chlorhexidine, de-ionized water. (j bagh coll dentistry 2013; 25(4):160-163). الخالصة لجنس ولھ تاریخ قدیم قدم ا, الھیل األخضر ھو ملك التوابل لما لة من راحة عطرة جدا وطعم.یجري استكشاف اإلعشاب على نطاق واسع كبدائل الصناعیة مضادة للبكتریا : المقدمة الغرض من ھذه الدراسة دراسة تأثیر تراكیز مختلفة من المستخلص المائي والكحولي للھیل على . معظم الناس یستخدمون الھیل كتوابل وغیر مدركین فوائدة الصحیة . البشري .وااللتصاق لبكتریا المكورات المسبحیة مختبریا, النمو, الحساسیة شملت التجربة اختبار حساسیة المیوتانز للتراكیز المختلفة لمستخلص الھیل .)22-18(تم جمع اللعاب من عشرة طالب تتراوح أعمارھم بین , في ھذه الدراسة :المواد والعمل كذلك تم دراسة تاثیر مستخلص الھیل على النمو الحیوي للمیوتانز وعلى قابلیة البكتریا لاللتصاق , ن الحفر في الوسط البكتیرياألخضر والمواد الضابطة األخرى بطریقة االنتشار م .على األسنان كلورھكسدین % 0.2لكن یبقى تاتیرھما اقل من . كان المستخلصان المائي والكحولي فعالن في تثبیط ھذه البكتریا, حسب طریقة االنتشار من الحفر في الوسط البكتیریا مختبریا :النتائج %) 20و% 15و% 10(تم اختبار تاثیر تراكیز . (p<0.01) .المستخلص الكحولي كان لھ تأثیر أقوى من المستخلص المائي بنفس التراكیز بفروق إحصائیة عالیة .كلوكونیت وجد آن مستخلص الھیل المائي والكحولي و الكلورھكسدین لھ فروقات إحصائیة عالیة في تقلیل النمو الحیوي و, للمستخلص المائي والكحولي على النمو الحیوي للمیوتانز مختبریا د ان وج .كلورھكسدین كلوكونیت% 0.2لكن یبقى المستخلص المائي والكحولي للھیل اقل فعالیة من .ساعة 24للبكتریا مقارنة بالنمو الحیوي للبكتریا بدون إضافة إي عامل بعد مرور كلورھكسدین كلوكونیت فعال في منع االلتصاق % 0.2 جمیع التراكیز المستخدمة لمستخلص الھیل المائي و الكحولي مختبریا غیر فعالة في منع التصاق البكتریا على األسنان وان .البكتریا .رھكسدین كلوكونیتأن مستخلص الھیل كان فعاال ضد بكتریا المیوتانز ولكن اقل تأثیرا من كلو: االستنتاج .الماء الغیر ایوني, الكلورھكسدین كلوكنیت, الھیل األخضر, المكورات المسبحیة المیوتانز :كلمات مفتاحیھ introduction dental caries is one of the most common infectious diseases in oral human cavity (1,2). the mouth contains a wide variety of oral bacteria, but only a few species of bacteria are believed to cause dental caries; mutans streptococcus and lactobacilli (3-5). the elimination of cariogenic bacteria from the oral cavity using antibacterial agents is one of primary strategies for prevention of dental caries (6). medicated oral rinses usually contains antimicrobial agents, such as chlorhexidine gluconate which is very potent chemo-prophylactic agent, it has abroad spectrum action especially against mutans streptococci (1) msc student, department of pedodontics and preventive dentistry, college of dentistry, baghdad university (2) professor, department of pedodontics and preventive dentistry, college of dentistry, baghdad university group. but it has many side effect like staining of teeth, altering the test of the mouth and desquamation of oral mucosa (7,8). herbs are being widely explored to discover alternatives to synthetic antibacterial agents (9). small cardamom often referred to as queen of spices because of its very pleasant aroma and taste, has a history as old as human race (10). most people use cardamom as a spice and are largely unaware of its numerous health benefits. in addition to its wide use for culinary purpose, cardamom has folkloric repute as carminative, stomachic, diuretic, antibacterial, analgesic, antiviral, anti-inflammatory, antifungal and is considered useful in treatment of many diseases (10,11). there are very little exclusive studies about small cardamom antibacterial effect on dental caries. for all of the above this study was conducted. j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry161 materials and methods small cardamom fruits were obtained from al-shoorga market. small cardamom fruits were american origin grade 4. the samples were carefully washed under de-ionized followed by sterile distilled water and then air dried for two days, pounded using a mixer grinder and stored in air tight bottles. there are two methods for extraction: water extraction and alcoholic extraction. for water extract 100grams of fruit powder of cardamom was soaked in 1000ml cold sterile distilled water in a conical flask and left undisturbed for 24h. for alcoholic extract 100 grams of fruit powder was kept in 70% ethanol for 3 consecutive days at room temperature. then both extract filtered off using a sterile whatman filter paper no1 (12).the filtered extract was concentrated under vacuum below 40oc using a rotaevaporator. the weight of the solid residue was recorded and taken as the yield of crude extract (13). stimulated saliva was collected from ten healthy looking students from university of al-mustansiriya aged (18-22) years in order to carry out in vitro experiments from which mutans streptococci were isolated, purified, and diagnosis according to morphological, microscopical, biochemical test and by vitek2 test. agar well technique was applied to study the antibacterial effects of different concentrations of water and alcoholic cardamom extracts (5%, 10%, 15%, 20%, 25%, 30%), compared with chlorhexidine 0.2% as a control positive and deionized water as control negative on mha media. these experiments were conducted on 10 isolates of mutans streptococci. the viability counts of mutans streptococci inoculated from broth media, to which 10%, 15%, and 20% of water and alcoholic cardamom extracts, chx 0.2% and de-ionized water were added have been estimated in comparison to the control (broth and bacteria only).the procedure was carried on 5 isolates of mutans streptococci. the prevention of adherence of mutans streptococci to the teeth and stainless wire after the 10%, 15%, and 20% of water and alcoholic cardamom extracts, chlorhexidine 0.2% and de-ionized water compared to the control positive (broth and bacteria without agent) and control negative (broth and agent without bacteria) had been tested in vitro these experiments carried on 50 extracted first premolars (right and left sides) form orthodontic department. results sensitivities of mutans streptococci (ms) to different concentrations of cardamom, chx and de-ionized water in vitro were determined by using agar well diffusion method. the diameter of inhibition zone (clear zone of no growth of ms around each well) was found to increase as the concentrations of cardamom extracts increase. de-ionized water showed no zone of inhibition while chx showed the highest zones of inhibition compared to the cardamom extracts as shown table (table 1).alcoholic extracts showed higher zone of inhibition compared to the same concentration of water with high significance differences (p<0.01) (table 2). the counts of ms were tested in vitro in the presence of 10%, 15%, and 20 % of water and alcoholic extracts of cardamom, chx, de-ionized water and control. lsd test used to compare the initial count, the counts of bacteria after 24 hr and their counts after using different agents. the result showed high significance differences between agents except a significance difference between initial count and chx and no significance difference between counts after 24and de-ionized water (table 3). all the concentrations of cardamom extracts tested were failed in the prevention of adherence of mutans streptococci, while control negative and teeth treated with chx showed no accumulation of dental plaque on them after seen days of incubation (table 4). discussion sensitivities of mutans streptococci to different concentrations of water and alcohol extracts of cardamom by agar well diffusion method had been tested in this study. results showed that cardamom extracted by water and alcohol were able to inhibit the growth of mutans streptococci, this finding were in coincidence with other studies (10,14). the diameter of zones of inhibition of ms were increased as the concentration of both cardamom extracts increased from 10% to 30% but still lower than chx 0.2%. for alcohol extract the zones of inhibition was much higher than water extract with highly significant differences, (this finding may be explained by the fact that, the components of cardamom that had antibacterial effects against ms and inhibit its growth, and were more soluble in alcohol than water. by laboratory analysis of small cardamom by hplc (high-performance liquid chromatography), in this study, it was found that concentration of major active compounds (1-8 cineole, α-terpinyl acetate) is higher in alcohol extract than in water extract. the antimicrobial property of small cardamom has been shown to be attributable to the essential oil fraction (15). j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry162 a highly significant reduction was found in the viable counts of mutans streptococci in 10%, 15% and 20% of both cardamom extracts compared to the control after 24 hr. it could be attributed to chemical constituents of small cardamom like cineole; the major active component of cardamom oil. it is a potent antiseptic that is known to kill bacteria producing bad breath and other infections (10). no one of any concentration of water and alcohol cardamom mouth washes tested was able to prevent adherence of bacteria. however in comparison to the control, plaque thickness was less. this reduction in plaque thickness may be attributed to the inhibitory effect of these agents on growth or metabolism of these bacteria rather than on adherence ability. table 1: mean and sd of ms inhibition zone in millimeter to different concentration to different agents (agar well diffusion methods) agents no. mean ± s.d anova test chx 10 17.50 0.57 f=349.541 d.f=10 p=0.000 hs water extract 5% 10 0 0 water extract 10% 10 7.35 0.66 water extract 15 % 10 9.10 0.45 water extract 20 % 10 10.15 0.52 water extract 25 % 10 11.20 0.34 water extract 30 % 10 12.55 0.49 alcoholic extract 5 % 10 0 0 alcoholic extract 10 % 10 10.35 0.62 alcoholic extract 15% 10 12.20 0.63 alcoholic extract 20% 10 14.75 0.48 alcoholic extract 25% 10 16.20 0.78 alcoholic extract 30% 10 16.90 0.51 de-ionized water 10 0 0 mean (mm). table 2: lsd test between sensitivity of mutans streptococci to same concentration of both water and alcoholic extracts of cardamom (agar well diffusion method) water extract alcoholic extract concentration mean difference p-value description 10% -3.00 0.000 hs 15% -3.10 0.000 hs 20% -4.60 0.000 hs 25% -5.00 0.000 hs 30% -4.35 0.000 hs table 3: lsd between agents in comparison with initial counts and counts after 24 agents initial count count after 24 mean difference p-value description mean difference p-value description w.e 10% 172.6 0.000 hs -82.0 0.000 hs w.e. 15% 138.4 0.000 hs -116.2 0.000 hs w.e. 20% 94.2 0.000 hs -160.4 0.000 hs a.e. 10% 150.8 0.000 hs -103.8 0.000 hs a.e. 15% 104.0 0.000 hs -150.6 0.000 hs a.e. 20% 56.4 0.004 hs -198.2 0.000 hs d.w. 222.0 0.000 hs -32.6 0.114 ns chx -45.4 0.018 s -300.0 0.000 hs w.e= water extract a.e= alcoholic extract d.f=8 j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry163 table 4: the effects of cardamom, de-ionized water and chx on adherence of ms in vitro agents (2 minutes) adherence control positive +ve control negative -ve 10 % water cardamom extract 15% water cardamom extract 20% water cardamom extract +ve +ve +ve 10% alcoholic cardamom extract 15 % alcoholic cardamom extract 20 % alcoholic cardamom extract +ve +ve +ve chx -ve de-ionized water +ve references 1. botelho m, nogueia n, bastos g, fonseca s, lemos t, matos f, montenegro d, heukelbach j, rao v, brito g. antimicrobial activity of essential oils from lippia sidoides, cavacr and thymol against oral pathogens. braz j med biol res 2007; 40: 349-56. 2. damle s. text book of pediatric dentistry. 3rd ed. arya; 2009. 3. nyvad b, fejerskove o. developmental, structure and ph of dental plaque. in: thylstrup a , fejerskove o (eds). textbook of clinical cariology. 2nd ed. munksgaard; 1996. pp.89-110 . 4. yu h, nakano y, yamashita y, oho t, koga t. effects of antibodies against cell surface protein antigen pac-glucosyl transferase fusion proteins on glucan synthesis and cell adhesion of streptococcus mutans. infect immun 1997; 65(6): 2292–8. 5. devi b, ramasubramaniaraja r. dental caries and medicinal plants. j pharm res 2009; 2(11):1669-75. 6. raja r, devi b. photochemical and antimicrobial screening of gymnema sylvestre, mentha arvensis, solanum surratense, extracts in dental caries. j pharm res 2010; 3(1): 21–3. 7. kolahi j, soolari a. rinsing with chlorhexidine gluconate solution after brushing and flossing teeth: a systematic review of effectiveness. quintessence int 2006; 37(8): 605-12. 8. pourabbas r, delazar a, chistsaz m. the effect of german chamonile mouthwash on dental plaque and gingival inflammation. iranian j pharm res 2005; 2:105-9. 9. kubo i, himejima m, muroi h. antimicrobial activity of flavor components of cardamom elettaria cardamomum (zingiberaceae) seed. j agric food chem 1991; 39: 1984–6. 10. sharma r. cardamom comfort. dent res j 2012; 9(2): 237. 11. duke j, bogenschutz m, ducelliar j, duke p. hand book of medicinal herbs. 2nd ed. crc press, boca raton; 2002. pp.153–4. 12. ogundiya m, okunade m, kolapo a. antimicrobial activities of some nigerian chewing sticks. ethnobotanical leaflets 2006; 10: 265-71. 13. bag a, bhattacharya s, bharati p, pal n, chattopadhyay r. evaluation of antibacterial properties of chebulic myrobalan (fruit of terminalia chebula retz.) extracts against methicillin resistant staphylococcus aureus and trimethoprimsuphamethoxazole resistant uropathogenic escherichia coli. afr j plant sciences 2009; 3(2): 25-9. 14. aneja k, radhika j. antimicrobial activity of amomum subulatum and elettaria cardamomum against dental caries causing microorganisms. j ethnobotanical 2009; 13: 840–9. 15. nanasombat s, lohasupthawee p. antibacterial activity of crude ethanolic extracts and essential oils of spices against salmonellae and other enterobacteria. j kmitl sci tech 2005; 5(3): 527-38. salwan f.doc j bagh college dentistry vol. 25(3), september 2013 gingival and alveolar oral and maxillofacial surgery and periodontics 110 gingival and alveolar ridge tumor-like overgrowth lesions salwan y.h. bede, b.d.s., f.i.b.m.s. (1) abstract background: tumor-like overgrowth lesions of the oral mucosa are pathological growths that project above the normal contour of the oral surface. a practical classification can be made according to the site of origin, the etiology and the histological appearance. the aim of this article is to evaluate and analyze patients with gingival and alveolar ridge tumor-like overgrowth lesions in terms of surgical treatment, diagnosis and outcome. materials and methods: patients complaining of these lesions were treated by surgical excision under local or general anesthesia; the excised lesions were submitted for histopathological examination, during the follow up period the patients were examined for complications and recurrence. results: pyogenic granuloma was the most frequently encountered lesion, followed by peripheral giant cell granuloma, fibrous hyperplasia, peripheral ossifying fibroma and neurofibroma. complications were minimal and recurrence occurred in one patient. conclusion: gingival and alveolar ridge overgrowths are common being mostly reactive rather than neoplastic in nature, global recurrence rate was 2.1%. keywords: gingival, alveolar ridge, overgrowth. (j bagh coll dentistry 2013; 25(3):110-114). introduction tumor-like overgrowth lesions of the oral mucosa are pathological growths that project above the normal contour of the oral surface1. a practical classification can be made according to the site of origin of the lesion, on the basis of the etiology and the histological appearance2, 3. histologically these lesions have been classified into; granulomatous, fibromatous and giant cell lesions4, another histological classification includes; fibrous, vascular and giant cell lesions1.different mechanisms can lead to the development of these lesions, most commonly reactive hyperplasia and neoplasia, the majority of tumor-like lesions of the oral mucosa are considered to be reactive rather than neoplastic in nature 1, 5, 6. reactive tumor-like overgrowths are common, and they often arise in response to local irritations like defective restorations, dental plaque and calculus, trauma or inflammation, also some lesions are drug induced or associated with systemic diseases and conditions 2, 5. gingival overgrowth is also termed epulis, a term described by axhausen, which is defined as a lump arising from the gingiva; it is a clinical description where the histological diagnosis is not verified3, 7. common gingival overgrowths include; pyogenic granuloma, peripheral ossifying fibroma, peripheral fibroma (fibrous hyperplasia) and peripheral giant cell granuloma5, 8. treatment of these lesions consists of surgical excision, with curettage of the adjacent dental and osseous tissues and histological analysis of the excised tissues 2,3,5. (1)lecturer. department of oral and maxillo-facial surgery. college of dentistry, university of baghdad. some of these lesions, although benign, have a tendency to recur especially with incomplete removal of the lesion or of the etiological factors involved5. the aim of this article is to evaluate and analyze patients with gingival and alveolar ridge tumor-like overgrowth lesions in terms of surgical treatment, diagnosis and outcome. materials and methods in the period extending from may 2009 to october 2012, 47 patients attended the department of oral and maxillofacial surgery in the college of dentistry, university of baghdad and the oral and maxillofacial surgery unit in al-yarmook teaching hospital complaining of gingival and/or alveolar ridge lesions, the duration of the lesions ranged from 3 months to 4 years, a thorough history was taken from the patients, a careful clinical and radiographic examination was carried out using periapical, occlusal and orthopantomogram views. the surgical treatment was carried out under local anesthesia in 42 patients using lidocain 2% with adrenaline 1:100.000, while general anesthesia was needed in 5 patients. the surgical treatment consisted of excision of the whole lesion to the bone, as an excisional biopsy, this was done using surgical blade, and in some cases electrocautery was used with curettage of the underlying bone and the roots of the adjacent teeth. the exposed bone was covered with iodoform gauze pack which was secured to the area using a tie over black silk suture 3/0, or using periodontal pack. the pack was left in place for 7-10 days and was removed afterwards, in four patients flap advancement and direct suturing was performed. the patients were given antibiotics (amoxicillin 500 mg plus j bagh college dentistry vol. 25(3), september 2013 gingival and alveolar oral and maxillofacial surgery and periodontics 111 metronidazole 500 mg three times daily) and analgesics (paracetamol 1000 mg as required) and mouth rinses for 7 days postoperatively. the excised specimens were submitted for histopathological examination. all patients were followed up for a minimum of 3 months, during this period the patients were examined for complications and recurrence. results the study group consisted of 47 patients, 26 females (55.3%) and 21 males (44.7%), the age of the patients ranged from 3-70 years with an average of 41.5 years. the duration of the lesions ranged from 3months to 4 years with an average of 12.25 months. the size of the lesions varied from about 1 cm to about 5 cm in their greatest dimension. in 7 patients, slight resorption of the underlying bone was evident radiographically. ten patients were diabetics, two were hypertensive and two female patients were pregnant in the third trimester, the lesion was excised after parturition. the gingiva and the alveolar ridge of the mandible were involved in 28 (59.6%) patients while the remaining 19 (40.4%) patients had maxillary gingival and/or alveolar ridge lesions. histopathological examination revealed inflammatory/reactive lesions in 46 (97.9%) of the cases and neoplastic lesion in only one (2.1%) case. in details the diagnoses were pyogenic granuloma (fig.1) in 20 patients (42.5%), peripheral giant cell granuloma in 19 patients (40.4%), fibrous hyperplasia in 6 patients (12.7%), peripheral ossifying fibroma in one patient (2.1%) and neurofibroma (fig.2) in one patient (2.1%). in patients diagnosed with pyogenic granuloma the mandibular gingiva and alveolar ridge mucosa was affected in 9 patients and the maxilla was affected in 11 patients, and females were more affected (13 patients) than males (7 patients). peripheral giant cell granuloma affected the mandibular gingiva and alveolar ridge mucosa in 13 patients, whereas the maxilla was affected in 6 patients, and males were more affected (11 patients) than females (8 patients). fibrous hyperplasia affected the mandible in 4 patients, and affected the maxilla in 2 patient, females were more affected (4 patients) while only 2 males were diagnosed with fibrous hyperplasia. (table 1) summarizes the results. no serious complications occurred after surgery other than the temporary inflammatory postoperative reaction, in 4 patients ulceration of the excision area occurred which was due to the early loss of the pack, the ulcers persisted for 2-3 weeks, and those patients were kept on mouth washes until the complete healing of the area. in one patient diagnosed with peripheral giant cell granuloma recurrence occurred one year after the surgical excision, making the recurrence rate of peripheral giant cell granuloma 5.2% and a global recurrence rate in this study 2.1%. the lesion was re-excised (fig.3 a, b and c), the laboratory investigations for the patient with recurrent peripheral giant cell granuloma revealed normal serum calcium and phosphorus and parathyroid hormone levels thus excluding hyperparathyroidism. discussion gingival and alveolar ridge overgrowths are common 2,5,9. most of these lesions are inflammatory and reactive in nature rather than neoplastic, it is estimated that about 85% to more than 90% of these lesions are reactive while the remainder is neoplastic in origin9, 10. in this paper the reactive lesions mounted for more than 97% of the lesions, while the neoplastic ones were only in 2.1% of the cases pyogenic granuloma was the most common lesion encountered in this study; this finding was also seen in other studies 9,10 . in some studies 11, 12, pyogenic granuloma was found to be the second most common lesion in the oral cavity. the term lobular capillary hemangioma was first introduced in 1980 by mills et al, as an underlying lesion of pyogenic granuloma and now this term is used synonymously with it 13,14. in this study pyogenic granuloma affected females more than males and maxilla was affected more than the mandible. these findings are in agreement with the findings in another study15 that analyzed the incidence of pyogenic granuloma in the oral cavity and found also that the most common site of occurrence is the gingiva. a recurrence rate ranging from 5.8%-10% was reported8, 15, but in this study no recurrence was noticed after the surgical excision during the time of follow up. peripheral giant cell granuloma, also known as giant cell epulis, giant cell reparative granuloma, osteoclastoma or giant cell hyperplasia16, was the second most common reactive lesion; another study11 found that this lesion was the most commonly encountered. studies have demonstrated that females are affected more than males 16-19, but in this study slight male predominance was noticed. also the mandible was affected more than the maxilla in this study, a finding that was also seen in other studies 18,19. the recurrence rate of peripheral giant cell granuloma in this study was 5.2%, other j bagh college dentistry vol. 25(3), september 2013 gingival and alveolar oral and maxillofacial surgery and periodontics 112 authors reported a recurrence rate that ranges between 1.4%-10% 8, 17. fibrous hyperplasia also called fibroma, irritation fibroma, traumatic fibroma or fibrous nodule, is reported to be the most common reactive lesion in the oral cavity 8,12,20, while some authors reported to be the second most common lesions in the oral cavity 9. in this study, this lesion followed pyogenic granuloma and peripheral giant cell granuloma in prevalence, possibly because this study was limited to gingival and alveolar ridge mucosal lesions, another possible reason is that these lesions occur most commonly along the bite line in the buccal mucosa, and it is likely that they represent a fibrous maturation of a preexisting pyogenic granuloma 8. the least common reactive lesion in this study was peripheral ossifying fibroma, it was first identified as a lesion by shephard in 1844 21 and its current name was given by eversole and rovin22. it is estimated that it accounts for about 15% of the solitary gingival growths10; it is also termed peripheral cemento-ossifying fibroma, peripheral odontogenic fibroma with cementogenesis, peripheral fibroma with osteogenesis, and peripheral fibroma with calcifications23. a recurrence rate ranging from 820% has been reported with an average time interval of 12 months 21, 22, 24, 25. comparison with this study was not possible since only one case was diagnosed as peripheral ossifying fibroma and no recurrence was noticed. while 97.9% of the lesions were reactive and inflammatory in origin, only one patient (2.1%) in this study was diagnosed with neurofibroma which is neoplastic in origin, it is an uncommon tumor of the oral cavity and seen either as a solitary lesion or as a part of neurofibromatosis26, it is the most common type of peripheral nerve neoplasms, and the most commonly reported intraoral site is the tongue and the buccal mucosa8. treatment of all these solitary lesions entails surgical excision of the lesion down to the bone with removal of all the causes of local irritation 8, 9,19,27. other protocols like the use of electrocautery, nd:yag laser, flash lamp pulsed dye laser, cryosurgery, intralesional injection of ethanol or corticosteroids or sodium tetradecyl sulfate sclerotherapy have been proposed, but the literature shows no difference using these modalities 19, 27. in the current study the traditional method of excision was used as it is readily available and requires no special equipment. a limitation of this study is the small sample size; this can be attributed to lack of compliance and the loss of patients to follow up, which were excluded. another reason is that this study is limited to lesions of the gingiva and alveolar ridge mucosa. references 1. pour mah, rad m, mojtahedi a. a survey of soft tissue tumor like lesions of the oral cavity: a clinicopathological study. iranian j pathol 2008; 3(2): 81-7. 2. ballini a, scattarella a, crincoli v, carlaio rg, papa f, perillo l, romanazzo t, bux mv, nardi gm, dituri a, cantore s, pettini f, grassi fr. surgical treatment of gingival overgrowth with 10 years follow up. head face medi 2010; 6:19. 3. seward gr, harris m, mcgowan da. killey and kay's outline of oral surgery, part 1. 2nd ed. bristol: wright; 1987. pp: 297-313. 4. anneroth g, sigurdson a. hyperplastic lesions of the gingiva and alveolar mucosa. acta odontol scand 1983; 41(2): 75-86. 5. rossman ja. reactive lesions of the gingiva: diagnosis and treatment options. the open pathology j 2011; 5: 23-32. 6. carvalho mde v, iglesias dp, do nascimento gj, sobral ap. epidemiological study of 534 biopsies of oral mucosal lesions in elderly brazilian patients. gerodontology 2011; 28(2): 111-5. 7. axhausen, g. allgemeine chirurgie in der zahn mundund kieferheilkunde hanser, münchen; 1947. 8. neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology. 2nd ed. philadelphia: wb saunders; 2002. pp. 437-495. 9. stablein mj, silverqlade lb. comparative analysis of biopsy specimens from gingiva and alveolar mucosa. j periodontol 1985; 56(11): 671-6. 10. chaturvedia r, guptab m, jainc a. peripheral ossifying fibroma: a case report. ind j dent 2012; 3(2): 89-93. 11. mighetl aj, robinson pa, hume wj. peripheral giant cell granuloma: a clinical study of 77 cases from 62 patients, and literature review. oral diseases 1995; 1(1): 12-9. 12. awange do, wakoli ka, onyango jf, chindia ml, dimba eo, guthua sw. reactive localised inflammatory hyperplasia of the oral mucosa. east afr med j 2009; 86(2): 79-82. 13. mills se, cooper ph, fechner re. lobular capillary hemangiom: the underlying lesion of pyogenic granuloma: a study of 73 cases from the oral and nasal mucous membranes. am j surg pathol 1980; 4: 470-9. 14. toida m, hasegawa t, watanabe f, kato k, makita h, fujitsuka h, et al. lobular capillary hemangioma of the oral mucosa: clinicopathological study of 43 cases with a special reference to immunohistochemical characterization of the vascular elements. pathol int 2003; 53: 1-7. 15. al-khateeb t, ababneh k. oral pyogenic granuloma in jordanians: a retrospective analysis of 108 cases. j oral maxillofac surg 2003; 61(11): 1285-8. 16. etoz oa, demirbas ae, bulbul m, akay e. the peripheral giant cell granuloma in edentulous patients: report of three unique cases. eur j dent 2010; 4(3): 329–33. j bagh college dentistry vol. 25(3), september 2013 gingival and alveolar oral and maxillofacial surgery and periodontics 113 17. katsikeris n, kakarantza-angelopoulou e, angelopoulos ap. peripheral giant cell granuloma. clinicopathologic study of 224 new cases and review of 956 reported cases. inter j oral maxillofacial surg 1988; 17(2): 94–9. 18. motamedi mhk, eshghyar n, jafari sm, lassemi e, navi f, abbas fm, khalifeh s, eshkevari ps. peripheral and central giant cell granulomas of the jaws: a demographic study. oral surgery, oral medicine, oral pathology, oral radiology, and endodontology 2007; 103(6): 39–43. 19. adlakha vk, chandna p, rehani u, rana v, malik p. peripheral giant cell granuloma. j indian soc pedod prev dent 2010; 28(4): 293-6. 20. kfir y, buchner a, hansen ls. reactive lesions of the gingiva. a clinicopathological study of 741 cases. j periodontol. 1980; 51(11): 655-61. 21. bhaskar sn, jacoway jr. peripheral fibroma and peripheral fibroma with calcification: report of 376 cases. j am dent assoc 1966; 73:1312-20. 22. eversole lr, rovin s. reactive lesions of gingiva. j oral pathol 1972; 1: 30-8. 23. shetty p, adyanthaya s. peripheral ossifying fibromaa clinical and histological evaluation of 51 cases. people’s j sci res; 2012: 5(1): 9-14. 24. cuisia ze, brannon rb. peripheral ossifying fibroma a clinical evaluation of 134 pediatric cases. pediatr dent 2001; 23: 245-8. 25. das um, azher u. peripheral ossifying fibroma. j indian soc pedod prev dent 2009; 27(1): 49-51. 26. richards d. neurofibroma of the oral cavity. br j oral surg 1983; 21(1): 36-43. 27. jafarzadeh h, sanatkhani m, mohtasham n. oral pyogenic granuloma: a review. j oral sci 2006; 48: 167-75. table 1: distribution of patients according to gender and site of lesions site/case (%) patients (%) diagnosis maxillary gingiva and alveolar ridge mucosa mandibular gingiva and alveolar ridge mucosa females males 11 (23.4%) 9 (19.2%) 13 (27.7%) 7 (14.9%) pyogenic granuloma 6 (12.8%) 13 (27.7%) 8 (17%) 11 (23.4%) peripheral giant cell granuloma 2 (4.2%) 4 (8.5%) 4 (8.5%) 2 (4.2%) fibrous hyperplasia 0 (0%) 1 (2.1%) 0 (0%) 1 (2.1%) peripheral ossifying fibroma 0 (0%) 1 (2.1%) 1 (2.1%) 0 (0%) neurofibroma 19 (40.4%) 28 (59.6%) 26 (55.3%) 21 (44.7%) total 47 (100%) 47 (100%) fig.1. pyogenic granuloma fig.2. neurofibroma. j bagh college dentistry vol. 25(3), september 2013 gingival and alveolar oral and maxillofacial surgery and periodontics 114 fig.3. giant cell granuloma. a: at the time of presentation. b: 4 weeks after surgical excision. c: recurrence one year after excision. j bagh college dentistry vol. 29(2), june 2017 evaluation of stainless steel oral and maxillofacial surgery and periodontics 83 evaluation of stainless steel intermaxillary fixation screws in treatment of favorable mandibular fractures thair abdul lateef, b.d.s., h.d.d., fibms (1) waleed khalil ismael, b.d.s., fibms (2) sameer saad mohsen, b.d.s. (3) abstract background: numerous methods have been described for achievement of intermaxillary fixation in the treatment of fractures of facial skeleton. conventional methods like erich arch bars and eyelet wires are currently the most common methods for achieving intermaxillary fixation (imf), however, they have their own disadvantages. since 1989, imf using intraoral self-tapping imf screws has been introduced for treatment of mandibular fractures. the aim of this study was to evaluate the efficacy, advantages, disadvantages and potential complications associated with using of selftapping imf screws in the treatment of mandibular fractures. material and methods: twenty patients with favorable mandibular fractures, attended to oral and maxillofacial surgery unit, al-yarmuk teaching hospital between november 2014 and october 2015, they were treated with imf screws. the parameters considered were duration of the procedure, perforations in the gloves, patient acceptance, oral hygiene, iatrogenic dental injuries, mouth opening, healing outcome, occlusal discrepancy and needle stick injuries during imf. results: the patients included in this study were 20 (17 males and 3 females). the extremes of age in this study ranged from 12 to 37 years. three patients had 2 fracture lines. assault was the most common cause of fractures. the most common site of fracture was the body and parasymphysis regions. two screws (2.5%) from 80 screws became loosened. one patient (5%) ended with malunion and malocclusion. one patient (5%) developed infection at screw site. three patients (15%) developed screws soft tissue burying. conclusion: imf screws considered to be a useful modality of treatment to establish maxillomandibular fixation. it is safe, and time-sparing technique; however, it is not without limitations or potential consequences in which the surgeon must be aware of in order to provide safe and effective treatment. keywords: mandibular fracture, intermaxillary fixation. (j bagh coll dentistry 2017; 29(2):83-89) introduction regardless the methods employed in management of mandibular fracture, definite basic surgical principles must be understood and followed closely in order to ensure the successful completion of treatment, and these include reduction, fixation, immobilization and rehabilitation (1). any discussion on management of mandibular fracture according to the history and development of treatment, dates back to edwin smith, an ancient greek. he provides a clear cut documentation for the treatment of mandibular fractures dating back as early as the seventeenth century (2). mandibular fractures can be treated by intermaxillary fixation alone, or by osteosynthesis with or without intermaxillary fixation. intermaxillary fixation (imf) is an age old procedure which is conventionally used for treatment of fractures involving maxillomandibular complex both for closed reduction and as an adjuvant to open reduction. intermaxillary fixation can be achieved by eyelets, arch bars, bonded brackets, cast metal splints, vacuum formed splints and pearl steel wires. (1) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2) consultant, depart ment of oral and maxillofacial surgery, alyarmuk teaching hospital. (3) resident oral and maxillofacial surgery, al-yarmuk teaching hospital however, these are time-consuming methods, with a constant danger of trauma to the surgeon’s fingers by the sharp wire ends. twisting a wire around a tooth conveys little feel as to its tightness and there is a danger of avulsion if force is too great. wires tightened during the application of arch bars around the teeth may cause ischemic necrosis of the mucosa and the periodontal membrane and if damage is extensive, tooth loss may result (3). intermaxillary fixation screws ( also called trans alveolar screws) is a method using screws fixed on the alveolar parts of maxilla and mandible have been advocated for intermaxillary fixation by arthur & berardo (1989) then jones (1999). hence achieving dental occlusion by bone to bone fixation while eliminating the teeth related problems. holes created in both jaws by drill either through small incision or trans-mucosally. intermaxillary fixation screws are quick, easy to use and greatly shorten the operating time. they are relatively inexpensive and reduce the risk of needle stick-type-injuries associated with wires. there is also no trauma to gingival margins and gingival health is easier to maintain as compared to arch bars or eyelets. despite the fact that the method is easy to apply it carries the risk of damage to the roots of the teeth (4). j bagh college dentistry vol. 29(2), june 2017 evaluation of stainless steel oral and maxillofacial surgery and periodontics 84 indications of imf screws: 1fracture mandible. 2endotracheal tube fixation in the edentulous patient with facial burns. 3post-maxillectomy obturator retention. 4orthognathic surgery. 5orthodontics (5,6). contraindications of imf screws: 1-pediatric patients with unerupted teeth. 2-patients with severe osteoporosis. 3severely comminuted fractures. 4extensive alveolar bone fractures. 5missile injuries to the jaws. (2,7) advantages of imf screws: 1-reduced risk of percutaneous contamination. 2-the procedure is easy to learn and use. 3operating time is reduced (quick and simple procedure). 4provide good intra operative fixation. 5post-operatively, there is less incidence of infection, trauma to the surrounding tissues and nerve injury. 6less pain and edema at the screw site. 7oral hygiene is good postoperatively after meticulous oral hygiene instructions. 8compatibility with any plating system. 9no discomfort to the patient. 10reduced trauma to the buccal mucosa. 11best for use when the teeth have been heavily restored. 12-reduced risk of needle stick injury as there is no wire fixation. 13simple removal. 14-cheap. (2,5) complications of imf screws: 1-fracture of the screws on insertion (8). 2-iatrogenic damage to teeth and bony sequestrum around the area of screw placement 3-if the speed of the drill is too fast surrounding mucosa and bone may be burnt, resulting in painful ulcerations and even drill tip may break off in bone. if the screws are left in place postoperatively this overheating can cause thermal necrosis of bone around the screw and loosening of head (7). 4-injury to the roots of the teeth adjacent to the screw fixation site (9). 5-the loosening of the screws (2). 6-periodontal abscess, cellulitis around screw and displacement of screw into the maxillary sinus (5). 7-embedded in the soft tissue over a period of time and during their removal necessitate use of stab incision under local anesthesia (2,5,10) . aims of the study: 1to evaluate the efficacy of imf screws in treatment of favorable fractured mandible. 2to assess the advantages, disadvantages and complications of imf screws. materials and methods patient's sample: this is a prospective clinical study included (20) patients with non-complicated fractured mandible attended to the oral & maxillofacial surgery unit, alyarmuk teaching hospital, between november 2014 and october 2015. in this study, the age ranged from 12-37 years (mean= 24.35), seventeen were males and three were females. the armamentarium: few instruments are used in this study, which is considered as one of the advantages of this method. the screws are made of stainless steel in different lengths (10-16 mm) and widths (2-3 mm). two types of screws were used with the following criteria: table 1: characteristic features of the screws screws characteristics no.1 no.2 screw material stainless steel stainless steel thread diameter 2 mm 3 mm overall length 16 mm 14 mm shaft length 14 mm 10 mm head diameter 4 mm 6 mm head length 2 mm 4 mm screw tip pointed, no grooves pointed, no grooves drive tapered hexagonal socket tapered hexagonal socket screw head neck small collar flange large collar flange drill bit diameter 1.6 mm 2.5 mm in addition to screws the following materials and instruments were used: fig. (1). 1-stainless steel wires for imf (0.5-0.6 mm) 2-screw driver 3-drills 4-cutter 5-dental mirror 6-dental syringe 7-dental needle 8-local anesthetic solution 9-povidone iodine solution 10-normal saline 11-hypodermic syringe 12hand piece 13-wire clamp j bagh college dentistry vol. 29(2), june 2017 evaluation of stainless steel oral and maxillofacial surgery and periodontics 85 figure 1: imf screws with instruments set. the procedure: after the diagnosis of the fracture the patients are prepared for operation, stay (bridle) wire was placed to 7 patients. all operations were done under local anesthesia except for 3 patients were done under general anesthesia. 2-3 cartridges of infiltration anesthesia are given to each patient (in the buccal mucosa of each quadrant). in the maxilla trans-mucosal drilling was done with drill bit under coolant (normal saline) just above the mucogingival junction between canine and first premolar teeth. left index finger was placed in the canine fossae which not only acts as a guide but also compress the vestibular tissue volume hence minimizing entangling of soft tissue to the drill bit. imf screw was inserted into the predrilled hole until the screw head just in touch with the underlying mucosa. the procedure is repeated for corresponding side. in the mandible the screw position was determined by the location of fracture line. the most preferred site was between canine and first premolar teeth followed by the space between the premolars. intermaxillary fixation was done with 0.50.6 mm stainless steel wire secured to the imf screws after reduction of bone fragments. fig. (2). figure 2: imf screws in situ. postoperative instructions: 1-maintain good oral hygiene by frequent tooth. brushing and mouth wash during imf period. 2-liquid or semi liquid diet until imf was removed. 3-psychological support by asking the patients to withstand the period of imf. 4-avoid any recurrent trauma to the region. 5-return back if any of the screws become loose or dislodged. statistical analysis data collected from clinical and radiological follow up was analyzed by statistical package for the social science(spss) software and microsoft office excel software version 21 for tables and figures, the analysis include: 1-descriptive statistics 2-tables for number and percentage 3-inferential statistics that is  t test: paired sample t test (assess reliability of data)  p value: the assessment of significance of result is as follow: aif p value is <0.05 then it is significant bif p value is >0.05 then it is not significant cif p value is <0.01 then it is highly significant results age and gender: twenty patients enrolled in this study, 17 males (85%) and 3 females (15%) with male to female ratio (5.6:1) fig. (3), with age ranged from 12-37 years with mean of 24.3 years. the age group 2029 years involved in this study was the dominant one, fig. (3). figure 3: age distribution in relation to decades. etiology of trauma: assaults were the most common etiology of fractures, found in 9 patients (45 %), followed by rta in 6 patients (30 %), fall in 4 (20%) patients and blast injury in 1 (5%). table (2). table 2: etiology of trauma cause assault rta fall blast injury total no. of patients 9 6 4 1 20 % 45 30 20 5 100 *chi-square=33.62 p<0.01 highly significant stability of screw: most of patients in this study ended the imf period with 78 fixed screws in position (97.5%), while only 2 screws in 2 patients became loosened 4 10 6 20 10-19 20-29 30-39 total j bagh college dentistry vol. 29(2), june 2017 evaluation of stainless steel oral and maxillofacial surgery and periodontics 86 at the 3rd week of imf (2.5%), however, this did not influence fracture healing. table (3). table 3: stability of screws stability of screw fixed loose no. of screws 78 2 % 97.5 2.5 *chi-square=9.88 p<0.01 highly significant postoperative occlusion: ten out of 20 patients included in this study present preoperatively with disturbed occlusion (50%). postoperatively one patient (5%) ended with disturbed occlusion fig. (4). figure 4: post-operative occlusion *chi-square=22.36 p<0.01 highly significant healing outcome: all patients included in this study completed imf period with good union (95%), except for one patient (5%) who has subcondylar fracture ended with malunion. table (4). table 4: healing outcome outcome good union malunion no. of patients 19 1 % 95 5 *chi-square=23.66 p<0.01 highly significant complications: the majority of patients in this study completed imf period without complications. two screws were loosened (2.5%) in two patients (10%), postoperative malocclusion and malunion occur in the same patient (5%), bone infection occur in one screw site (1.25%) and soft tissues burying occur in nine screws site (11.25%) in three patients. table (5) and table (6). table 5: complications related to the number of patients complication no. of patients % screws loosening 2 10 malocclussion 1 5 malunion 1 5 bone infection 1 5 soft tissue burying 3 15 table 6: complications related to the number of screws complication no. of screws % screws loosening 2 2.5 bone infection 1 4.3 soft tissue burying 9 11.25 discussion the main goals in successfully treating mandibular fractures include: reduction, stabilization of the fracture, and achievement of proper dental occlusion. in the process of fully satisfying these criteria, it is also advantageous to use techniques that reduce the risk of percutaneous transmission of blood-borne diseases, operating time and duration of general anesthesia and hospital costs (2) . most of the patients included in this study were young (12-37 years), and males were more than female with male to female ratio is about (5.6:1). this indicate that fractured mandible occur more commonly in active young age groups and more frequent in males than females this may be due to the more outdoor activities in iraqi society. one of the advantages of this procedure is the short time for insertion and removal of screws (time saving) when compared with other conventional methods of imf. biswas (2012) reported that the time needed for insertion of screws was about 10 min (12), while mathieu (2009) registered the time needed for insertion of of about 13 min. in this study the time of insertion of the screw ranged from 7-20 min with a mean of 10.5 min, while the time of removal ranged from 3-8 min with a mean of 4.4 min. only one patient needed 8 min for removal because of soft tissue burying (mucosal overgrowth) which necessitate using of stab incision under local anesthesia. in general it has been noticed an obvious differences in time between imf screws and other conventional method like arch bar (45-60 min) (2) . all patients were satisfied with imf screws both during the procedure and during imf period. this is belonged to: 1-little tissues trauma 2-short operation time 3-simple procedure 19 1 undisturbed disturbed j bagh college dentistry vol. 29(2), june 2017 evaluation of stainless steel oral and maxillofacial surgery and periodontics 87 safety for the surgeon and assistants by this method is published in the literature. in this study the researcher didn't face any of complications related to the safety as there is no needle stick injury and gloves perforation for both the surgeon and the assistants. fracture of screws is another complication of. (8,14 ,15) reported a case of fracture of screw at the junction of screw head and threaded portion. fortunately, there was no case of screw fracture that may be attributed to the proper surgical technique. another complication mentioned with the screws was the injury to the roots of the teeth adjacent to the screw fixation site. (9) reported one case of root damage using self-tapping screws, (16) recorded 4% root damage. in this study, also no case of root or tooth injury owing to the enthusiastic surgery. during transmucosal drilling, cooling is of a prime importance. the soft tissue acts as a cuff around the drill bit, preventing coolant to reach the bone. it causes thermal necrosis and subsequent loosening of screw. screw loosening was noticed in 6.5% (15 out of 229) of the screws placed in the most recent report (15), while (17) reported 6 (3.2%) imf screws in four patients being loose and 7.5% (5 out of 66) of screw loosening was reported by. in this study screw loosening was noticed in 2.5% (2 out of 80). both screws became loose at the 3rd week of imf. those patients informed the operator that they tried to open the screws by any way. retightening of screws was done and the treatment was completed without affecting the final outcome. another complication associated with selftapping imf screws is that, they become embedded in the soft tissue over a period of time and during their removal necessitate the use of stab incision under local anesthesia. (18) reported 2.04% of patients with mucosal overgrowth, whereas (18,19) reported multiple cases of soft tissue burying and (15) reported 11 (5.8%) screws in 11 (45.8%) patients showed partial mucosal overgrowth. in the present study 11.25% (9 of 80 screws) in three patients (15%) developed mucosal overgrowth, two screws needed stab wound for removal and the remaining 7 screws removed by reflection of mucosa and exposing the screw head. maintaining good oral hygiene is easy when imf screws are used for fixation. this is because screws allow better cleaning and brushing of teeth and gum. imf screws are different from other conventional methods like arch bars or circumdental wiring, which may cause trauma to interdental gingiva and allowing food debris to stick under arch bar or wire loops which become difficult to be removed. this may cause considerable degree of gingivitis and even periodontitis. all patients in this study presented with good oral hygiene. bone infection and interdental sequestration are rare reported incidents were noticed in the articles (8). in this study one screw site (1.25%) developed periapical infection and sinus tract which lead to resoption of root and the tooth became non-vital three month after screw removal, this may due to infection from periodontium. patient was referred for endodontic therapy. fig. (4) and (5). (13,18) were reported 4% of patients end with malocclusion, whereas (16) reported 2% of patients ended with this complication. 95% of patients included in this study completed imf period with good occlusion and good alignment except for one patient (5%) developed malocclusion and malunion. this is may be due to imperfect reduction of the fracture. (13) reported 4% incidence of mandibular deviation when the mouth was opened. all patients in this study completed imf period without any mandibular deviation. (13,20) were reported 2% of patients end with limitation of mouth opening. in this study no one of patients complained from this consequence. in conclusion, self-tapping imf screws provided good imf for the 20 cases in the present study. postoperatively, there was no incidence of trauma to the surrounding tissues and nerve injury. there were no signs and symptoms of pain and edema at the screw site in all the cases at the end of 1st and 5th postoperative week. only one case of infection occur in periapical area of screw site. it was easier to maintain oral hygiene with imf screws compared to other conventional methods. the procedure ended with reasonable outcomes with few complications provided that it is performed in the right manner. figure 4: screw site infection developed sinus tract after its removal. j bagh college dentistry vol. 29(2), june 2017 evaluation of stainless steel oral and maxillofacial surgery and periodontics 88 figure 5: opg of the same patient illustrating periapical radiolucent lesion at the adjacent tooth. references 1-barber, h.d., woodbury, s.c., silverstein, k.e., fonseca, r.j.: mandibular fractures, in textbook of oral & maxillofacial trauma, vol. 1, 2nd ed. w.b. saunders company, philadelphia, p 493, 1997. 2-nandini g. d., ramdas balakrishna, and jyotsna rao: self tapping screws v/s erich arch bar for inter maxillary fixation: a comparative clinical study in the treatment of mandibular fractures j maxillofac oral surg. 10(2): 127–131, jun 2011. 3-ayoub af, rowson j.: comparative assessment of two methods used for interdental immobilization. j craniomaxillofac surgery. 31:159–61, 2003. 4-aldegperi a.: pearl steel wire: a simplified appliance for maxillo mandibular fixation. br j oral maxillofac surg. 10.1054/bjom, 1998. 5-christopher fowell, sunil bhatia, brian castling: a novel use of intermaxillary fixation screws for postmaxillectomy obturator retention british journal of oral and maxillofacial surgery 51 e195–e196, 2013. 6-fleissig y., rushinek h., regev e.: intermaxillary fixation screw for endotracheal tube fixation in the edentulous patient with facial burns. int. j. oral maxillofac. surg. 43: 1257–1258, 2014. 7-jones dc. the intermaxillary screw: a dedicated bicortical bone screw for temporary intermaxillary fixation. br j oral maxillofac surg. 37(2):115–116, 1999. 8-coburn dg, kennedy dw, hodder sc.: complications with intermaxillary fixation screws in the management of fractured mandibles. br j oral maxillofac surg. 40(3): 241–243, 2002. 9-majumdar a.: iatrogenic injury caused by intermaxillary fixation screws. br j oral maxillofac surg. 40(1):84– 88, 2002. 10-bush rf.: maxillomandibular fixation with intraoral cortical bone screws: a 2 year experience. laryngoscope.104:1048–1050, 1994. 11-kathiravan purmal, mohammad khursheed alam,,* abdullah pohchi, and noor hayati abdul razak: 3d mapping of safe and danger zones in the maxilla and mandible for the placement of intermaxillary fixation screws plos one. 8 (12): e84202, 2013. 12-biswas kp, ahuja a, and singh vp: efficacy of intermaxillary fixation screws; health renaissance, vol 10 (no. 1):69-71. january-april, 2012. 13-mathieu laurentjoye, claire majoufre-lefebvre, md,françois siberchicot, md, and anne sophie ricard, md: result of maxillomandibular fixation using intraoral cortical bone screws for condylar fractures of the mandible, j oral maxillofac surg. 67:767-770, 2009. 14-holmes s, hutchison i.: caution in use of bicortical intermaxillary fixation screws. br j oral maxillofac surg. 38(5):574, 2000. 15-van den bergh b. , blankestijn j. , van der ploeg t., tuinzing d.b., forouzanfar t.: conservative treatment of a mandibular condyle fracture: comparing intermaxillary fixation with screws or arch bar. a randomised clinical trial. journal of cranio-maxillofacial surgery, 2015. 16-sahoo n. k. and ritu mohan imf screw: an ideal intermaxillary fixation device during open reduction of mandibular fracture. j maxillofac oral surg.9 (2): 170–172, jun 2010. 17-zanyar, mustafa amin: reliability of intermaxillary fixation screw in the treatment of fractured mandible, prospective clinical evaluation 2010. 18-roccia f, tavolaccini a, dell’acqua a, fasolis m.: an audit of mandibular fractures treated by intermaxillary fixation using intraoral cortical bone screws. j craniomaxillofac surg. 33(4):251–254, 2005. 19-hoffmann a, mast g, ehrenfeld m.: verwendung von imfschrauben zur mandibulo-maxilla¨ren fixation [usage of imf screws for mandibulo-maxillary fixation]. op journal. 19:70–75, 2003. 20-thaller sr: management of mandibular fractures. arch otolaryngol head neck surg. 120:44, 1994. j bagh college dentistry vol. 29(2), june 2017 evaluation of stainless steel oral and maxillofacial surgery and periodontics 89 المستخلص في التثبیت اھنالك عدة طرق قد وصفت لتحقیق التثبیت بین الفكین لعالج كسور عظام الوجھ والفكین. و ھنالك مجموعھ من الطرق التي تعتبر االكثر شیوعالخلفیة: تم استخدام المسامیر داخل الفم في عملیھ تثبیت الفكین لعالج كسر عظم الفك 1989 في عام مثل االسالك الفوالذیة والجسور الفوالذیة ولكل منھما عیوبھ الخاصة . ن الفكین في مسامیر التثبیت بیالسفلي ألول مرة. ان الھدف من ھذه الدراسة ھو تقییم الفعالیة، المزایا والعیوب، والمؤشرات والمضاعفات المحتملة المرتبطة باستخدام السفلي. عالج كسور عظم الفك شملت الدراسة عشرون مریضا یعانون من كسور عظم الفك السفلي حضروا لقسم جراحة والوجھ والفكین في مستشفى الیرموك التعلیمي للفترة ما : المواد والطرق المسمار، الثقوب في الكفوف، درجة تقبل . وكانت المقاییس في ھذه الدراسة ھي : الوقت الذي یستغرقھ وضع 2015وتشرین االول 2014بین تشرین الثاني المرضى، نظافة الفم، تلف األسنان وإصابات وخز اإلبر. عاما. ثالثة مرضى كانوا یعانون من كسرین 37 -12سبعة عشر مریضا كانوا من الذكور وثالثة من اإلناث شملوا في ھذه الدراسة. تراوحت اعمارھم بین النتائج: ) من ٪2,5العتداءات ھي السبب األكثر شیوعا للكسور. كان المكان األكثر شیوعا للكسر في منطقة جسم الفك السفلي . اثنین من المسامیر (في الفك السفلي. كانت ا ثة مرضى ) انتھى بالتھاب العظم في موقع المسمار. ثال٪5) انتھى بسوء االلتحام وسوء اإلطباق. مریض واحد (٪5مسمار أصبحا مرتخیان . مریض واحد ( 80 ) انتھوا بانغمار المسامیر داخل اللثة .15٪( م تكن من دون ل لقد أظھرت الدراسة الشاملة ان مسامیر التثبیت الفكیة طریقة مفیدة لتثبیت كسور الفكین. حیث أنھا طریقھ آمنة و وقتھا قصیر. ومع ذلك،االستنتاجات: العواقب من أجل توفیر عالج أفضل وفعال للمرضى . قیود أو عواقب لذلك یجب أن یكون الجراح على علم بھذه j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 1 evaluation the effect of addition of plasma treated polypropylene fiber and silanized silicon dioxide nanoparticles composite on some properties of heatpolymerized polymethylmethacrylate ahmed g. ahmed, b.d.s. (1) intisar j. ismail, b.d.s., m.sc., ph.d. (2) abstract background: polymethylmethacrylate (pmma) is the most commonly used material in denture construction. this material is far from ideal in fulfilling the mechanical requirements, like low impact and transverse strength and poor thermal conductivity are present in this material. the purpose of this study was to study the effect of addition a composite which include 1%wt silanized silicone dioxide nano fillers (sio2) and 1wt% oxygen plasma treated polypropylene fiber (pp) on some properties of heat cured acrylic resin denture base material (pmma). materials and methods: one hundred (100) prepared specimens were divided into five groups according to the te sts, each group consisted of 20 specimens and these were subdivided into two groups (unreinforced heat cured acrylic resin as control group)and reinforced acrylic resin with ( 1%wt nano sio2 and 1% wt oxygen plasma treated polypropylene fibers) group. the transverse strength¸ impact strength, indentation hardness (shored), surface roughness and water sorption and solubility were investigated. the results were statistically analyzed using descriptive and t-test. results: the results of this study show that a highly significant increase in impact strength (10.4939 kj/m2),surface hardness (89.9375) surface roughness (0.9498) and water sorption (0.0171mg/cm2) was observed with the addition of 1%wt silanized (sio2) nanoparticles and 1%wt oxygen plasma treated polypropylene fibers to (pmma) , also significant decrease in transverse strength (103.4753 n/mm2), nonsignificant decrease occurred in water solubility which was (0.0005mg/cm2). conclusion: the incorporation of 1%wt silanized sio2 nanoparticles and 1%wt oxygen plasma treated polypropylene fiber to heat cure pmma form a composite improves the impact strength, surface hardness and surface roughness of acrylic resin, at the same time this addition increase the water sorption and decrease water solubility; while significant decrease in transverse strength. key words: silicon dioxide nano filler, polypropylene fiber, plasma treatment. (j bagh coll dentistry 2016; 28(4):1-8) introduction the goal of dentistry has been to replace or restore the lost or damaged tooth structure for satisfying esthetic and functional requirements. dentures remain the most common choice of prosthetic devices. dentures made from resin based polymeric systems were common because of their ability to be molded with outstanding esthetic appearance and appropriate mechanical characteristics in most clinical conditions (1). this material is not ideal in every respect and it is the combination of virtues rather than single desirable property that accounts for its popularity and usage. regardless of the satisfying esthetic demands it is far from ideal in fulfilling the mech anical requirements of prosthesis. however, a polymer requires some modifications in its structure or physical properties to get a greater range of functions. (a)m.sc. student. department of prosthodontics. college of dentistry, university of baghdad. (b)assistant professor. department of prosthodontics. college of dentistry, university of baghdad. one modification technique is adding fillers to the polymer in order to produce a composite with enhanced properties, such as improvement in mechanical strength, electrical conductivity or thermal stability (2). the filler materials include organic, inorganic, and metallic particulate materials in both micro and nanosizes. several types of polymers and polymer-matrix composites reinforced with metal particles have a wide range of manufacturing applications (3). organic-inorganic hybrid nanocomposite materials have been studied in recent years, with the expectation that nanocomposite material will serves a significant and evolutionary means of achieving properties that cannot be realized with single material (4). nanocomposites have the potential to be implemented as a new high strength matrix in a composite (5). these composites are desired due to their low density, high corrosion resistance, simplicity of fabrication, and low cost (6). the addition of inorganic fillers like alumina into polymers is primarily aimed at the cost reduction and stiffness improvement (7). fiber reinforced polymer composites (frpcs) have j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 2 generated wide interest in various engineering field because of high specific strength, high modulus, low density and better wear resistance (8).the concept of combining nanocomposites as matrix material with fiber reinforcement in a new three-phase composite reinforcement has been shown to be very successful. lighter, thinner, stronger, and cheaper structures are the goals of materials science and engineering applications nowadays (9). materials and methods before starting the tests pp fiber and nano silica should be under go surface treatment separately to increase the adhesion with pmma matrix. the silica would be silanised using a coupling agent to guarantee the interfacial adhesion between the filler and matrix (10-11), while pp fiber undergo surface treatment by oxygen plasma (12) one hundred acrylic specimens were constructed by conventional flasking technique using heat cure acrylic resin, the samples were divided into five groups according to the using tests and each group sub divided into two subgroups:unreinforced heat cured acrylic resin as control group and reinforced acrylic resin with (1%wt nano sio2 and 1% wt oxygen plasma treated polypropylene fibers) group mechanical and physical tests a. impact strength test the specimens were prepared with dimensions (80mm x 10mm x 4mm) (iso 179, 2000) for unnotched specimens. specimens were stored in distilledwater at 37 ºc for 48 hours before be ingtested (13).the impact strength test was evaluated following the procedure recommended by the iso 179 with impact testing device. the specimens were supported horizontally at each end and struck by freeswingingpendulum of 2 joules. the scale readings give the impact energy in joules. the charpy impact strength of unnotched specimens was calculated in kilo joules per square meter by the following equation: impact strength = x103 (iso, 2000) (kj/m2) e : the impact energy in joules, b: the width of the specimens in millimeters, d :the depth of the specimens inmillimeters b. transverse strength test specimens were prepared with dimensions (65mm x 10mm x 2.5 + 0.1mm). all specimens stored in distilled water at 37 ºc for 48 hours before being tested (13).the test was performed using instron universal testing machine (wdw200 e), each specimen was positioned on the bending fixture which consist of two parallel supports (50 mm apart), the fullscale was 50 kg and the load was applied with across head speed of 1mm/min. by a rodplaced centrally between the supports making deflection until fracture occurs. c. surface hardness test specimens of heat cure acrylic resin were prepared with a dimension (65mm x 10mm x 2.5+ 0.1mm). all specimens were stored in distilled water at 37ºc for 48 hours before being tested (13). surface hardness was determined by using (shore d) durometer hardness tester which is appropriate for acrylic resin material. the apparatus consist of spring-loaded ind enter (0.8mm in diameter), the indenter is attached to digital scale that is graduated from 0 to 100 units. the standard method is to press down firmly and quickly on the indenter and record the reading. three readings were done on each specimen (one in the centerand other at each end) then the mean of three readings was calculated. d. surface roughness test specimens with dimensions (65mm x10mm x 2.5+ 0.1mm) were prepared to be used for surface roughness test. all the specimens were stored in distilled water at 37 ºc for 48 hours before being tested (13).the profilometer device was used to study the effect of fiber and nano particles reinforcement on the microgeometry of the test surface. this device is supplied with sharp stylus surface analyzer from a diamond to trace the profile of the surface irregularities by recording of all the peaks and recesses which characterized the surface by its scale. the acrylic specimen was placed on its stable stage and the location of the tested area was selected (the specimen was divided into four parts) then the analyzer was traversed along the tested area and the mean of four readings was calculated by this equation: transverse strength(s) = 3 pl / 2bd2 where, p = fracture load l = span length b = sample width d = sample thickness. ewater sorption and solubility test acrylic disc specimens were prepared by using plastic pattern having dimensions of (50mm+1mm in diameter and 0.5 mm ±0.1 mm in thickness). the specimens were dried in desiccators containing freshly dried silica gel .the desiccator was stored in an incubator at a37 ºc ±2 ºc for 24 hours after that the specimens were removed to room temperature for one hour then j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 3 weighted with electronic balance with accuracy of (0.0001g). this cycle of weighting was repeated every day until a constant mass (m1) (conditioned mass) was reached (14). all discs of all groups were immersed in distilled water for 7 days at 37 ºc ± 2 ºc (14). the discs were removed from the water with a dental tweezers wiped with a clean dry towel until free from visible moisture, waved in the air for 15 seconds and weighted; this mass was recorded as (m2). the value of water sorption was calculated for each disc from the following equation: wsp = water sorption in mg/cm2 m2 = the mass of the disc after immersion in distilled water (mg) m1=the mass of the disc before immersion in distilled water (conditioned mass) (mg). s = surface area of the disc (cm2) in order to obtain the value of water solubility the discs were again reconditioned to a constant mass in the desiccator at 37 ºc ± 2 ºc as done in the first time for sorption test and the reconditioned mass was recorded as (m3). the solubility during immersion was determined for each disc by the following equation: wsl= water solubility in mg/ cm2. m1= the conditioned mass (mg). m3= the reconditioned mass (mg). s= the surface area of the disc (cm2). results the results obtained from the measured data were computerized using spss system version 20for statistical analysis and classified according to the followings experimental groups: group (a) control group group (b) acrylic resin+sio2 1% wt + pp 1 % wt a-impact strength test mean value, standard deviation, maximum and minimum of the impact test results are presented in table (1). group b (study group) exhibited the highest impact strength mean value (10.4939 kj/m2), while the a (control group) shows the lowest one (8.3313kj/m2). b-transvers strength test mean value, standard deviation, maximum and minimum of the transverse test results are presented in table (3). as shown in table (3) group a (control group) exhibited the highest transverse strength mean value (112.6651n/mm2), while the b (study group) shows the lowest one (103.4753n/mm2) c-hardness number test mean value, standard deviation, maximum and minimum of the surface hardness test results are presented in table (5). group b (study group) exhibited the highest hardness mean value (89.9375), while the a (control group) shows the lowest one (85.0200). d-surface roughness test mean value, standard deviation, maximum and minimum of the surface roughness test of hot cure acrylic resin results are presented in table (7).group b (study group) exhibited the lowest roughness mean value (0.9498 μm), while the a (control group) shows the highest one (1.4402 μm). e-water sorption mean value, standard deviation, maximum and minimum of the water sorption test of hot cure acrylic resin results are presented in table (9).group b (study group) exhibited the highest water sorption mean value (0.0171 mg/cm2), while the a (control group) shows the lowest one (0.0138 mg/cm2). f-water solubility mean value, standard deviation, maximum and minimum of the water sorption test of hot cure acrylic resin results are presented in table (11).group b (study group) exhibited the lowest water solubility mean value (0.0005 mg/cm2), while the a (control group) shows the highest one (0.0006 mg/cm2). table 1: descriptive parameters of impact test kj/m2 group n minimum maximum mean s.d group a (control) 10 7.23 9.13 8.3313 .63685 group b (study) 10 9.03 13.58 10.4939 1.53140 table 2: t-test analysis of impact test groups standard error mean differences t-test p-value significance j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 4 group a (control) .52448 -2.16258 -4.123 .001 hs group b (study) table 3: descriptive parameters of transverse test n/mm2 groups n minimum maximum mean s.d. group a (control) 10 102.90 123.40 112.6651 7.02951 group b (study) 10 89.59 126.28 103.4753 9.92008 table 4: t-test analysis of transverse strength test groups standard error mean differences t-test p-value significance group a (control ) 3.84476 9.18982 2.390 .028 s group b (study) table 5: descriptive parameters of hardness number test groups n minimum maximum mean s.d. group a (control) 10 84.30 85.95 85.0200 .48959 group b (study) 10 88.88 90.88 89.9375 .70072 table 6: t-test analysis of hardness number test groups standard error mean differences t-test p-value significance group a (control ) .27031 -4.91750 -18.192 .000 hs group b (study) table 7: descriptive parameters of surface roughness test um groups n minimum maximum mean s.d. group a (control) 10 1.32 1.59 1.4402 .08386 group b ( study) 10 .90 1.02 .9498 .04335 table 8: t-test analysis of surface hardness test groups standard error mean differences t-test p-value significance group a (control) .02985 .49034 16.425 .000 hs group b (study) table 9: descriptive parameters of water sorption test mg/cm2 groups n minimum maximum mean s.d. group a (control) 10 .01 .02 .0138 .00094 group b (study) 10 .02 .02 .0171 .00153 table 10: t-test analysis of water sorption test groups standard error mean differences t-test p-value significance group a (control) .00057 -.00337 -5.936 .000 hs group b (study) table 11: descriptive parameters of water solubility test mg/cm2 groups n minimum maximum mean s.d. group a (control) 10 .00 .00 .0006 .00061 group b (study) 10 .00 .00 .0005 .00062 table 12: t-test analysis of water solubility test groups standard error mean differences t-test p-value significance j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 5 group a (control) .00028 .00006 .230 .821 ns group b (study) discussion physical and mechanical properties of polymer are critical in attaining clinical success and long evity of the material. the denture base material must be able to tolerate high impact force as well to normal masticatory forces (15). one of the approaches to resolve the fracture problem in acrylic denture base was the incorporating of some types of reinforcement material into the polymer. the idea of new three-phase composite reinforcement from combining a nano particles and fibers as a filler with the material to be reinforced as a matrix has been shown to be very successful (9). in this in vitro study with its limitation in performing this concept, some mechanical and physical properties of acrylic denture base material were evaluated after the addition of silanized sio2 nanoparticles and oxygen plasma treated polypropylene fiber in order to improve the mechanical and physical properties with minimum effect on other properties. a-impact strength test the results of impact strength test as shown in table (1) has shown that the addition of 1%wt silanized sio2 nanoparticle and 1%wt oxygen plas ma treated polypropylene fibers increased the mean values of impact strength (10.4939 kj/m2) compared with the control group (8.3313 kj/m2 ). the highly significant increased value in impact strength may be related to the effect of interaction between silanized sio2 nanoparticles and polymer depending on the size of the contacting surfaces (specific surface area of the filler), smaller particles have larger surface area; lead to increase strength. this agreed with tanasă et al (16). also this increase value in the impact strength may be due to the interfacial shear stren gth between matrix and nano filler which is high due to the formation of supra molecular bonding or cross-links which shields or cover the nanofillers which in turn inhibit cracks propagation. this also suggested by sun et al (17). the addition of silanized sio2 nano filler may form efficient network (3dimentional network) of pmma and sio2nano particles. pmma chain totally transferred in to 3d-network like chains at 1% of nano filler thus lead to decrease the segmental motion and increase the impact strength (18). in the other hand, the functional group in addition to rough surface due to oxygen plasma treatment of poly propylene fibers may be lead to increase fiber-matrix bonding which may lead to prevent the crack propagation and change in direc tion of cracks resulting in minor cracks between the fibers¸ this can be correlated to the improved impact strength of fiber-reinforced specimens compared to the control group where there is unobstructed crack propagation .these findings are in agreement with results obtained by mowade et al (2) and mohammed (19). polarization of the surface by the presence of functional groups due to oxygen plasma treatment of polypropylene fibers may increase the surface energy of the fibers and its compatibility with other materials which may improve the impact strength, in combination with high surface energy of nano particles may contribute in increase impact strength. these results are in agreement with results obtained by hocker (12) and mohammed (19). so the combination of both silanisedsio2nano particles and oxygen plasma treated polypropylene fibers incorporating in 2%wt lead to increase the impact strength of the composite. b-transverse flexural strength test according to the results of this study it has shown that there were statistically a significant decrease in transvers strength of pmma reinforced with nano sio2 1%wt and 1%wt pp fiber as shown in table (3). the flextural failure of the denture base material is considered the primarymode of the clinical failure. the flexural three-point bending test is convenient in comparing the materials as it simulates the type of stress that applied to the denture during the mastication (20). possible explanations for this may be due to: 1. the stress concentration at the sharp corners of irregular sio2 particles. 2. too many filler particles can lead also to changes in mode of crack propagation through the specimen and the modulus of elasticity of the resin due to an increased amount of fillers. 3. low percentage of nano particle surface treatment with silane coupling agent which may lead to insufficient nanoparticle-matrix bond. 4.aggregation of silanized sio2 nanoparticles because of higher surface energy, this aggregation result in micro-fracture that weakened the nanocomposites at this percentage¸ so this study in agreement with andrew et al (21) who suggested that" single individual nano filler exhibited no distinct fracture. in contrast the j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 6 nanoclusters (aggregated) fillers showed multiple fractures" such defects can speed up the failure process and might be an area in which crack propagation is started. on the other hand, this may be related to the random orientation of fibers permit only sm all portion of the strengthening to be directed perpendicular to the applied stress. also may be due to the internal voids formed in the fiber-resin composite caused by poor wetting of fibers with resin (maybe not all the using fibers will undergo changes from plasma treatment)¸ these voids were oxygen reserves that permitted oxygen to inhibit radical polymerization of the acrylic resin inside composite. this could result in higher residual monomer content of fiber composite and affect strength. this result is agree with vallittu et al (22). the increase in internal repulsive or negative forces after addition of the silanized sio2nano particle and oxygen plasma treated polypropylene fiber to the resin samples may contribute in reduction of transverse force the plasticization effect of oxygen plasma treated polypropylene fiber may be result in decreased transverse strength, this agree with al momen (23) who found after the addition of 5% and 10% styrene butadiene rubber (sbr) into acrylic resin produce a significant decrease in transverse strength was observed duo to increase in flexibility of composite containing sbr. this study disagree with mohammed (19) who found after the addition of 2.5%wt oxygen plasma treated polypropylene fiber a non-significant increase in flexural strength test. c-surface hardness test it has been reported that surface hardness of composite resins influenced by both the organic matrix and fillers. with regard to the organic matrix, hardness depends on the density and structure of the polymer formed and degree of conversion after polymerization (24). it was found in this study that hardness value showed a highly significant increase in the study group compared with control group as shown in table (5). the increased hardness of the nano composite at 1%wt may be attributed to the accumulation of the (sio2) particles in to the acrylic matrix especially on the surface. similar finding were reported by al momen(23), while the result of this study disagree with abdul ameer (25) where titanium powder lower the indentation hardness of acrylic resin. this could be due to difference in the material and particles size between sio2 used in this study and titanium powder particles size. other factor of increase in hardness may be due to the use of coupling agent which increases adhesion between nanoparticles and the polymer and increases interphase stiffening that leads to increase nanocomposite’s elastic modulus and strength, this suggestion agree with zakaria and nezhad (26). this increase also could be related to the existence of polypropylene fibers near or at the surface of the composite which very stiff and hard ̧ these findings were in agreement with sato and ogawa (27), mohammed (19), almomen (23) and salih (28). d-surface roughness it appears from the literature that the roughness of dental acrylic resins is mainly affected by material inherent feature, polishing technique and operator's skills (29). table (7) and (8) showed that the surface roughness of the acrylic denture base was highly significant decrease in the studied group compared to the control group. it is difficult to make direct comparisons of roughness values with other studies because of methodology used¸ disparities in the experimental procedures as well as measuring the surface roughness procedure and differences in the type of pmma material used. surface modification of sio2 nano particles with silane coupling agent and treatment of polypropylene fibers with oxygen plasma may result in increase bonding among the component of the composite may lead to decrease chipping away of the particles from the surface of the composite during deflasking and grinding, this in turn may contribute in decreasing the roughness of the composite. also this may be attributed to the small particle size of sio2 (20-30nm) which is accumulated at the surface of study specimen. e-water sorption and solubility tests from the results, there were highly significant increases in water sorption in group b (study group) compared to the group a (control group). the surface treatment of sio2nano particle with silane coupling agent may change the hydrophobicity of sio2nano particles to hydrophilic leading to increased water adsorption to the surface of the specimen. porosity or micro void formed during polymerization process of acrylic resin may facilitate water transportation and act as a reservoir for it. non reactant interfacial surfaces between silanized sio2nano particles and polymer matrix j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 7 as a result of aggregation of sio2 nano particles may provide a room for water molecules resulting in increasing water sorption. also increase could be attributed to fact that plasma treatment changed totally hydrophobic surface of untreated pp fibers to hydrophilic surface due to incorporating of functional groups, this explanation also agreed with skacelova et al (30). table (11) and (12) show a non-significant decrease in the values of water solubility of the specimens containing sio2 and oxygen plasma treated pp fiber. this decrease could be attributed to the fact that sio2 is insoluble in water so that the addition of sio2 to the mass of the specimens which act as additives and their presence will lead to decrease in the solubility of acrylic resin. also this may be attributed to the transverse interlocking occurred between the reinforced plasma treated polypropylene fibers and acrylic resin which lead to decrease the residual monomer content subsequent lesser solubility of the polymer will occur. references 1. meng tr, latta ma. physical properties of four acrylic denture base resins. j contemp dent pract 2005; 6: 93-100. 2. mowade t k, dangesh p, thakre m b, kamble v d effect of fiber reinforcement on impact strength of heat polymerized polymethyl methacrylate denture base resin: in vitro study and sem analysis. j adv prosthodont 2012; 4(1): 30-6. 3. jungil k, kang ph, yc nho. positive temperature coefficient behavior of polymer composites having a high melting temperature. j appl polym sci 2004; 92: 394–401. 4. novak bm. hybrid nanocomposite material between inorganic and organic polymer. adv mater 1993; 5: 422-33. 5. gotro j. thermosets encyclopedia of polymer science and technology 2004; 12: 207-60. 6. zhu k, schmauder s. prediction of the failure properties of short fiber reinforced composites with metal and polymer matrix. comput mater sci 2003; 28: 743–8. 7. rothon rn. mineral fillers in thermoplastics filler manufacture and characterization. adv polym sci 1999; 139: 67–107. 8. hutchings im. tribology: friction and wear of engineering materials. london: crc press; 1992. 9. leszczyn´ska a, njuguna j, pielichowski k, banerjee jr. polymer/montmorillonite nanocomposites with improved thermal properties: part 2 thermal stability of montmorillonite nanocomposites based on different polymeric matrixes. thermochim acta 2007; 454: 1– 22 10. zuccari ag, oshida y, moore bk. reinforcement of acrylic resins for provisional fixed restorations. part i: mechanical properties. biomed mater eng 1997; 7: 327–43. 11. sideridou id, karabela mm. effect of the amount of 3-methacyloxypropyltrimethoxysilane coupling agent on physical properties of dental resin nanocomposites. dent mater 2009; 25: 1315–24. 12. hocker h. plasma treatment of textile fiber. pure appl chem 2002; 74(3): 423-7. 13. american dental association specification no. 57, 12 (1999) for denture base polymers. chicago. : council on dental materials and devices. ansi/ada. 14. american dental association specification no.12; 1999 for denture base polymers chicago. council on dental materials and devices. 15. umemoto k, kurata s. basic study of a new denture base resin applying hydrophobic methacrylate monomer. dent mater j 1997; 16(1):21-30. 16. tanasă f, zănoagă m, darie r. evaluation of stressstrain properties of some new polymer-clay nano composites for aerospace and defence applications. international conference of scientific paper, afases, 2014. 17. sun l, ronald fg, suhr j, grodanine jf. energy absorption capability of nano composites: a review. composites science and technology 2009; 69: 23922409. 18. hu y, zhou s, wu l. surface mechanical properties of pmma/silica nano composite prepared by in situ bulk polymerization. polymer 2009; 50: p299-304, 19. mohammed wi. the effect of addition of untreated and oxygen plasma treated polypropylene fiber on some properties of heat cure acrylic resin. a master thesis, university of baghdad, college of dentistry, 2013. 20. yunus n, rashid aa, azmi ll, abu-hassan mi. some flexural properties of a nylon denture base polymer. j oral rehabil 2005; 32:65-71 21. andrew rc, william m, garry jp, fleming. the mechanical properties of nanofilled resin based composite. dental materials 2009; 25:180-7. 22. vallittu pk, ruyter ii, kstrand i. effect of water storage on the flexural properties of eglass and silica fibers acrylic resin composite. int. j prosthodont 1998; 11: 340-50. 23. almomen mm. effect of reinforcement on strength and radiopacity of acrylic denture base material. a master thesis, department of prosthodontic, university of baghdad, 2000. 24. anfe tea, caneppele tmf, agra cm and vieira gf. microhardness assessment of different commercial brands of resin composites with different degrees of translucence. brazi oral res 2008; 22(4): 358-63. 25. abdul ameer as. evaluation of changes in some properties of acrylic denture base material due to addition of radio-opaque fillers. a master thesis, university of baghdad, college of dentistry, 2006). 26. zakaria ak, nezhad ks. the effects of interphase and interface characteristics on the tensile behaviour of nanocomposites. nanomaterials and nanotechnology article. department of mechanical engineering, university of tabriz, 2013. 27. sato h, ogawa h. review on development of polypropylene manufacturing process. sumitomo kagaky 2009; 2: 1-11. 28. salih zh. the effect of fibers reinforcement on some properties of visible light cured acrylic denture base material. a master thesis, department of prosthodontic, university of baghdad, 2006. j bagh college dentistry vol. 28(4), december 2016 evaluation the effect restorative dentistry 8 29. corsalini m, boccaccio a, lamberti l, pappalettere c, catapano cand carossa s. analysis of the performance of a standardized method for the polishing of methacrylic resins, the open dentistry journal, 2009, 3, 233-240. 30. skacelova d, fialova m, stahel p, cemak m. improvement of surface properties of reinforcing polypropylene fibers by atmospheric pressure plasma treatment. belfast, uk, no. d13, 2011. bilal f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 cranial base pedodontics, orthodontics and preventive dentistry108 cranial base morphology in different skeletal classes (a cross-sectional lateral cephalometric study) bilal i. abd, b.d.s. [1] fakhri a. ali, b.d.s., m.sc. [2] abstract background: it was stated in scientific literatures that the entire craniofacial complex is influenced by the growth of the cranial base structures. nevertheless, many times this is not the case, and this point is subject to great controversy so the aim of this study is to evaluate the possible differences in cranial base shape and flexure between different skeletal classes for both genders and to investigate any possible correlation between cranial base variables and other skeletal base variables. materials and methods: the sample include 75 lateral cephalometric radiographs of iraqi adults aged between 18-25 years (39 males, 36 females), collected from patients and undergraduate students in the orthodontic department of college of dentistry-baghdad university. the total sample was divided to three major categories depending on anb angle and dental occlusion into class i control group (12 males, 13 females), class ii group (13 males, 12 females) and class iii group (14 males, 11 females). results: the results revealed that no significant difference in all the angular measurements of both skeletal and cranial bases existed between genders, while all linear and area measurements were usually higher in males than females and there was no significant difference in all the skeletal and cranial bases angles existed between different skeletal classes in both genders meaning that there is no relationship between cranial base flexure and skeletal classes. the angles n-s-ar, n-s-ba and sn-fh were always correlated negatively with both the angles sna and snb in all skeletal classes for both genders, while the angle sba-fh showed weaker correlation with the angles sna and snb than the angle sn-fhin all skeletal classes for both genders. conclusion: cranial base flexure is not the main cause of skeletal malocclusions. key words: cranial base, lateral cephalometric, skeletal classes. (j bagh coll dentistry 2013; 25(special issue 1):108113). introduction the cranial base supports the brain and provides adaptation between the developing neurocranium and viscerocranium during growth(1,2).located on a junction point between the cranium, midface and glenoid fossa, the cranial base may affect the development of both the face and the cranium (3). the cranial base forms the floor of the cranial vault and extends from the foramen caecum anteriorly to the basi-occipital bone posteriorly. it is essentially a midline structure comprising parts of the nasal, orbital, ethmoid, sphenoid and occipital bones. sellaturcica lies near the center of the cranial base and divides it into anterior (sella to nasion) and posterior (sella to basion) limbs. the two limbs of the cranial base form a flexion of 130-135 degree at sella. the maxilla appears attached to the anterior segment and the mandible to the posterior segment (4). the cranial base or saddle angleusually measured radiographically as the angle between the basion-sella-nasion points, although the articulare and bolton points have also been used to describe the posterior limit, making it difficult to compare the results of different studies (5). [1]m.sc. student, dep. of orthodontics, college of dentistry, university of baghdad. [2]professor, dep. of orthodontics, college of dentistry, university of baghdad. the cranial base plays a key role in craniofacial growth, helping to integrate, spatially and functionally, different patterns of growth in various adjoining regions of the skull such as components of the brain, the nasal cavity, the oral cavity, and the pharynx. depending on the fact that the maxilla is connected with the anterior part of the cranial base and the rotation of the mandible is influenced by the maxilla, a relationship can be found between the cranial base variations and sagittal malpositions of the jaws (6). different factors like basicranial morphology, head and neck posture and soft tissue stretching are thought to influence the occurrence of a skeletal malocclusion. the influence of cranial base angulation as a factor in the etiology of sagittal jaw discrepancies is still a matter of debate. while investigation of a longitudinal data can show the cause-effect relationship of this problem, a cross-sectional sample may search for morphological differences in different skeletal classes (6). materials and methods the sample consisted of lateral cephalometric radiographs collected from patients attending the orthodontic department of college of dentistrybaghdad university and undergraduate students. all of the sample were iraqis with an age ranged between 18-25 years.the sampleconsisted of 3 j bagh college dentistry vol. 25(special issue 1), june 2013 cranial base pedodontics, orthodontics and preventive dentistry109 groups with a total of 75 subjects (39 males and 36 females)as shown in table 1: table 1: distribution of the sample distribution of the sample male female total class i 12 13 25 class ii 13 12 25 class iii 14 11 25 total 39 36 75 1. class i control group (12 males & 13 females): anb 2°4°, bilateral class i molar and canine relationship, normal overjet and overbite (2-4 mm), well aligned upper and lower arches with less than 3mm of spacing or crowding in either of them. 2. class ii group (13 males & 12 females): anb > 4°, bilateral class ii molar and canine relationship, overjet> 4 mm. 3. class iii group (14 males & 11 females): anb < 2°, bilateral class iii molar and canine relationship, overjet< 2 mm. class ii division 2 malocclusion were excluded from the study. the sample criteria include: 1) no oral habits according to the subject history and clinical examination. 2) no history of previous orthodontic treatment. 3) no gross facial asymmetry. 4) no history of facial trauma or craniofacial disorder interfering with the normal growth, such as cleft lip or palate. 5) for class i group, clinically almost equal middle and lower facial height and full complement of permanent dentition excluding the third molars. lateral cephalometric radiographs were taken for the entire sample separately under strict standardized conditions. after that a software program (autocad 2012) was used for analyzing them. the following anatomical cephalometric bony landmarks were used in this study (figure 1): 1. nasion (n): the most anterior point on the fronto-nasal suture in the mid-sagittal plane. 2. sellaturcica (s): the midpoint of the hypophysial fossa. 3. point a: is located at the most posterior part of the anterior shadow of the maxilla, usually near the apex of the central incisor root. 4. point b: is located at the most posterior point on the shadow of the anterior border of the mandible, usually near the apex of the central incisor root. 5. menton (me): the most inferior point on the outline of the symphysis. 6. gonion (go): a point midway between the most inferior and most posterior points on the angle of the mandible. 7. articulare (ar): the point of intersection of the dorsal contour of the condylar head and the outer margin of the cranial base. 8. orbitale (or): located on the lower most point of the outline of the bony orbit in the radiograph. 9. basion (ba): the lowest point on the anterior margin of the foramen magnum in the median plane. 10. porion (po): the upper surface of the ear rod of the cephalometric head holder. the following constructed cephalometric points were used in this study (figure 1): 1. point i: represents the intersection of the two lines n-ba and s-go. 2. point j: represents the intersection of the two lines n-ba and ar-go. the following skeletal base measurements were done (figure 1): angular measurements 1. sna: represents the antero-posterior position of the maxilla in relation to the anterior cranial base. 2. snb: represents the antero-posterior position of the mandible in relation to the anterior cranial base. 3. anb: difference between sna and snb and represents the antero-posterior relation of the maxilla and mandible to each other linear measurements 1. ar-go: the distance measured between articulare and gonion and represents the length of the ramus. 2. s-go: the distance measured between sella and gonion and represents the posterior facial height. 3. n-me: the distance measured between nasion and menton and represents the anterior facial height. 4. jarabak ratio(posterior facial height s-go x100 / anterior facial height n-me) (7). the following cranial base measurements were done (figure 1): angular measurements 1. n-s-ar: the angle between the anterior and the posterior cranial base and formed at the point of intersection of the s-n line and the sar line. j bagh college dentistry vol. 25(special issue 1), june 2013 cranial base pedodontics, orthodontics and preventive dentistry110 2. n-s-ba: the angle between the anterior and the posterior cranial base. 3. sn-fh: the inclination of the anterior cranial base. 4. sba-fh: the inclination of the posterior cranial base. linear measurements 1. s-n: the distance measured between sella and nasion and represents the anterior cranial base length. 2. s-ba: the distance measured between sella and basion and represents the posterior cranial base length. 3. n-ba: the distance measured between nasion and basion and represents the total cranial base length. 4. s-ar: the distance measured between sella and articulare and represents the posterior cranial base length. area measurements 1. the area n-s-i. 2. the area s-i-j-ar. 3. the area s-ar-j-ba. 4. the area ba-n-s. figure 1: cephalometric points and measurements results all the data were subjected to computerized statistical analysis by using descriptive statistics including mean, standard deviation, standard error, minimum and maximum and by using inferential statistics including anova test and pearson correlation test. the results show that no significant difference was found in the angular measurements of both the skeletal and cranial bases between genders and also no significant difference was found in the same angular measurements between different skeletal classes in both genders (figures 2,3), while the linear measurements s-go, s-ba and n-ba were significantly higher in males than females in all skeletal classes. the mean value of jarabak ratio was found to have non-significant difference between genders in all of the skeletal classes, while it was significantly larger in the order of class i > class ii > class iii in both genders. the mean value of the linear measurement argo and s-ba were found to have non-significant difference between all skeletal classes in both genders and also the mean value of the linear measurement n-me and s-ar showed nonsignificant difference between all skeletal classes in males only and the mean value of the linear measurement s-n also showed non-significant difference between all skeletal classes in females only. the mean value of the area measurements s-ij-ar and s-ar-j-ba showed non-significant difference between al skeletal classes in males only while the mean value of the area measurements n-s-i and ba-n-s showed nonsignificant difference between all skeletal classes in females only. the pearson correlation test showed that the cranial base angles n-s-arand ns-ba and angle sn-fh showed negative somewhat moderate correlation with sna and snb angles in all skeletal classes for both genders while the angle sba-fh showed weaker correlation with the angles sna and snb than the angle sn-fh. j bagh college dentistry vol. 25(special issue 1), june 2013 cranial base pedodontics, orthodontics and preventive dentistry111 figure 2: comparisons of mean values of angular measurements of skeletal and cranial bases between different skeletal classes in males figure 3: comparisons of mean values of angular measurements of skeletal and cranial bases between different skeletal classes in females discussion this study targeted all the three types of skeletal jaw relationships (class i, class ii and class iii skeletal patterns) and it aimed to investigate the differences in their cranial base morphology. the identifications of cephalometric points, angular, linear and area measurements were done directly on a digital radiograph by using a computer with modern analyzing software in an effort to enhance the reliability of the measurements and to reduce tracing and measuring errors. frankfort horizontal was selected as the reference plane in describing the anterior and posterior cranial bases because of the close physiologic relation between the ear and the eye as represented by the cephalometric landmarks porion and orbitale(8).the variation of the frankfort plane has been shown to vary around zero degrees and represents a horizontal to the earth’s surface (9).the semicircular canals in the ear and the orbital size change little at an early age with the downward movement of the maxilla compensated by deposition on the orbital floor (10). the sample selected in this study was composed of cephalometric radiographs of young adults 18-25 years of age because most of the growth of the craniofacial bones could be considered as complete after the age of 18 years (11). the non-significant gender difference of the angular measurement of the cranial base angles agrees with other studies (12-19), while in general, the linear measurements and area were found larger in males than females and this indicated that the males have larger head than females and can be attributed to the fact that the maximum growth rate of females is reached two years earlier than males(20) and this was also in agreement with previous studies (17, 21-25). the reason why the angularmeasurements were not significantly different between genders in contrast to the linear and area measurements was because the angular measurements usually refers to the direction of growth rather than to increase or decrease in the size. additionally, the angular measurements were influenced by the geometrical factors. the non-significant skeletal class difference in the angular measurements of the cranial base in both genders indicates that the cranial base angles n-s-ar and n-s-ba were not the only cause for skeletal malocclusions and this was similar to ns ns ns ns ns ns ns ns ns ns ns ns ns ns j bagh college dentistry vol. 25(special issue 1), june 2013 cranial base pedodontics, orthodontics and preventive dentistry112 previous studies (6,26-28); however, other studies showed that the cranial base angle was found larger in the order of class ii > class i > class iii(17-19,29).the negative correlation between cranial base angles (n-s-ar and n-s-ba) and maxillary and mandibular prognathism angles sna and snb despite being moderate to weak correlation, it means that whenever the cranial base angles increase,the angles sna and snb (the maxillary and mandibular prgnathism angles) both decreases together almost equally indicated by the non-significant difference in the cranial base angles between skeletal classes and these results agrees with other studies (4,19,30). finally it should be noted that the differences between the results of this study and the other studies may be attributed to the differences in the case selection procedure because other authors (4) selected the cases on the bases ofdental classification not skeletal and it is not always necessary that dental occlusion coincide with skeletal jaw relationship (31). another fact to consider is that for example ns-ar angle can vary due to changes in the height of the anterior cranial base (32). this is due to the fact that this angle depends on the location of three points: nasion, sella, and articulare. if one of these points changes position, the value of the resulting angle will be equally modified. this means that, if nasion is placed in a more superior position, the anterior cranial base s-n plane will tilt upwards, and this will open the angle of the cranial base. the opposite result takes place when nasion is located in lower position (28). another variation which must be taken into account is the length of the posterior cranial base which can compensate any cranial flexure (32). for example, the effect of a closed cranial base angle which will locate glenoid fossa and lower jaw in an anterior position could be countered by an increased length of the posterior cranial base, which would displace the articular point and consequently the mandible, to a posterior position (28). in this study, we can conclude that the cranial base angle is not the only factor in determining a malocclusion. there are three main factors influence facial prognathism-opening of the cranial base angle, the relative forward movement of components such as the maxilla and the mandible to the cranium and the amount of surface deposition along the facial profile between the nasion and menton. despite the genetic influence in the occurrence of malocclusions, the role of soft tissues in the position of the jaws should not be underestimated (33). it was hypothesized that factors inducing cranial extension, such as impairment of nasal airflow, will influence craniofacial development, because of increased pressure from the soft tissue of the anterior regions of the face and neck. there are also several 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1967. 34. solow b, kreiborg s. soft-tissue stretching: a possible control factor in craniofacial morphogenesis. scand j dent res 1977; 85(6): 505-7. 35. festa f, tecco s, dolci m, ciufolo f, di meo s, filippi mr. relationship between cervical lordosis and facial morphology in caucasian women with skeletal class ii malocclusion: a cross sectional study. cranio 2003; 21(2):121–9. 36. d’attilio m, epifania e, ciuffolo f, salini v, filippi mr, dolci m. cervical lordosis angle measured on lateral cephalograms; findings in skeletal class ii female subjects with and without tmd: a cross sectional study. cranio 2004; 22(1): 27-44. j bagh college dentistry vol. 29(3), september 2017 how much do oral and maxillofacial surgery and periodontics 31 how much do they know? oral hygiene attitude and periodontal awareness in iraqi adults basma fathi alanbari, b.d.s., m.sc. (a) abstract background: the scarce literature regarding oral hygiene attitude and periodontal awareness in iraqi adults warranted the conduction of this study in order to provide a public profile and a baseline data for further researches. aims of the study: assessing the oral hygiene attitude and periodontal awareness in a sample of iraqi adults. materials and methods: self-administered questionnaires were distributed to 500 adults. results: out of the 500 questionnaires distributed, 482 were included in the study.92% of the sample practiced tooth brushing, 69% out of them reported a daily brushing pattern with variable frequency,69% of the sample did not receive oral hygiene education from any source ,more than half of the sample 60 % used the horizontal brushing method, interdental aids was utilized by 42% of the sample with the dental floss being the commonest type 52%, mouthwash used by 37% and tongue cleaning was uncommon as only 22 % of the sample perform it. 78% of the sample did not know what dental plaque is while dental caries were well known by almost the entire sample 98%. 93% reported having gingival bleeding with only 5% out of them referred to the poor oral hygiene as the causative factor. the motive for seeking periodontal therapy for 80% of the sample was restoring the gingival esthetics. conclusions: the public periodontal awareness and knowledge is still poor in iraq, the solution requires shared resources and multiple approaches. key words: oral hygiene attitude, periodontal awareness, tooth brushing, iraqi adults. (j bagh coll dentistry 2017; 29(3):31-38) introduction periodontal diseases and dental caries are classified as the most common infectious diseases affecting the human as well as the two globally leading causes of tooth loss (1,2), the quality of everyday life in periodontal diseased individuals was the subject of many researches recently according to those studies the experience of pain, endurance of dental abscess, difficulty in eating and chewing and embarrassment due to mobile or lost teeth have tremendous effect on the general wellbeing (3). adding to their oral manifestations and consequences, periodontal diseases have a profound impact on the general health according to the 2013 who report as the four most prominent ncds (non-communicable diseases) cardiovascular diseases, diabetes, cancer and chronic obstructive pulmonary diseases do share common risk factors with periodontal diseases (4), while the world is obsessed with the aforementioned diseases, oral diseases till the present day is widely neglected (5) and their management is limited to treatment rather than prevention (6). periodontal awareness is a prerequisite not only for a healthy dentition but for a successful dental treatment as well, since absence or even a declined level of oral hygiene and periodontal awareness may contraindicate treatment and (in case treatment is conducted) can lead to treatment (a)assistant lecturer, department of dentistry, al-rafidain university college. failure, therefore; the first step in treatment of dental patient should focus on building the patient knowledge, enable the patient to process the provided information in order to modify the behavior and commit to an acceptable standard of oral hygiene (7). regarding this topic, the dental health providers must be aware of great differences between information and education. individuals who are informed about dental health are aware of the consequences of specific health practice, but they may be involved in an unsound course of action. in contrast educated individuals are not only well informed, but also use this information in their daily life ideally (8). the scant literature on dental health awareness, attitude, oral health-related habits and behavior among the adult population in iraq prompted us to conduct this study to assess the oral hygiene attitude and periodontal awareness in a sample of iraqi adults. materials and methods this was a cross-sectional study of randomly selected 500 participants (325 males and 175 females) selected among individuals attending periodontics clinic at al-rafidain dental college teaching hospital in baghdad. the sample age range was (16-71) years with a mean age of 33 years. this research was carried out during the academic year 2015-2016. the data were collected by a self-assessment questionnaires (appendix 1) incorporating three domains, first related to j bagh college dentistry vol. 29(3), september 2017 how much do oral and maxillofacial surgery and periodontics 32 personal and socio-demographic data like age, gender, level of education, and occupation, second related to periodontal awareness and health knowledge included items on the pattern of brushing, type of the brush, brush replacement frequency, the source of oral hygiene knowledge, interdental aids, tongue brushing and mouth wash utilization, periodontal awareness were assessed by testing the patient information regarding gingival bleeding, the knowledge about causative factors of periodontal diseases and the third was self-reported dental attendance pattern, type of dental treatment received in the last 12 months and the reason for seeking periodontal treatments. questionnaires included both open and closed ended questions in which the subjects have prechosen items to relate to. after patient’s approval to be enrolled in the study was acquired, full explanations of the study and question contents were provided to the patients in a simple language by the investigator. later, the questionnaires were filled personally by the patients and delivered back to the investigator. partially filled questionnaires were excluded from the study. data were collected from the completed questionnaires then entered into statistical package for social sciences (spss) program version 19.0 which was utilized for data analysis in terms of frequencies and percentages. results study sample comprised 500 patients attended the periodontics department at al-rafidain dental teaching hospital. a 500 questionnaire was distributed by the researcher to randomly selected patients, after exclusion, a total of 482 questionnaires were included in the study. the average age of the sample was 33 years old with a 16-71 years old age range. male gender dominated the sample with a percentage of 66% while females comprised 34%. twenty two percent (22%) of the sample finished the elementary school, 47% reported high school as their educational level, 31% were a college graduates (table 1). table1:gender distribution according to gender and educational level variables no. % gender male 318 66 female 164 34 total 482 100 educational level elementary 108 22 high school 226 47 college 148 31 total 482 100 daily brushing and frequency of brushing brushing was reported by the majority of the sample (92%). sixty nine percent (69%) reported a daily brushing pattern with a variable frequency (table 2). table 2: sample distribution according to brushing attitude and frequency brushin g no. % brushing no. % frequency yes 444 92 once/day 212 48 twice/day 88 20 three times/day 4 1 occasionall y 140 31 no 38 8 total 444 100 total 482 100 source of oral hygiene education the parents were the source of information regarding oral hygiene for only 23% of the patients with the majority 69% reported that they brushed their teeth without any provided information, only 4%of the sample reported that their dentist advised them about the correct oral hygiene procedures, 3% reported that their school teachers educated them and the remaining 1% reported that rely on the media (television's programs and commercials regarding)and practice tooth brushing in the same manner they saw on media (fig. 1). type of dental brush (regarding the bristles hardness) hard type tooth brush were utilized by 17% of the patients, 39% utilized the medium type, 28 % utilized the soft type while the remaining 16% had never noticed what type of brush they used (fig. 2). brushing direction more than half of the sample 60% were brushing horizontally, 32% brushed vertically and 8% used the circular motion (fig. 3). 23% 69% 4% 3% 1% parents no source dentist school tv fig. 1: sample distribution according to source of oral hygiene education j bagh college dentistry vol. 29(3), september 2017 how much do oral and maxillofacial surgery and periodontics 33 changing the brush the vast majority of the patients 77% did change their tooth brush while about one third of the patients 33% did not. regarding the time interval for brush replacement, 41% replaced it each 3 months, 8% each 6 months, 1% once a year, 50% did not report a specific time interval because they do not change the brush periodically. interdental aids interdental aids were utilized by 42 % of the sample, 52% out of them used the dental floss, 5% used the interdental brush and 43% used the tooth picks. fifty eight percent (58%) of the surveyed patients reported that they do not use any type of interdental aids (table 3). mouthwash as adjunctive to tooth brushing, mouthwash used by 37% of the patients. mouthwash advantages as reported by the patients were to prevent halitosis by 95% and additional cleaning by 5% of the sample (table 3). tongue cleaning approximately 22% of the patient clean their tongue, 89% of them used the same brush for tooth brushing & tongue cleaning while only 11% used the tongue scrapper (table 3). table 3: sample distribution according to the utilization of interdental aids, rinsing with mouth wash and tongue cleaning interdental aids yes type no. % no. % dental floss 105 52 202 42 interdental brush 11 5 tooth picks 86 43 no 280 58 total 482 100 mouthwash yes 176 37 no 306 63 total 482 100 tongue cleaning yes tooth brush 96 89 108 22 tongue scraper 12 11 no 374 78 total 482 100 level of public knowledge regarding dental caries, calculus and plaque ninety eight percent (98%) of the patients knew what dental caries is when they were asked about it, 47% knew dental calculus while only 22% knew what dental plaque is (fig. 4). fig. 4: sample distribution according to knowledge level regarding dental caries, calculus and dental plaque respectively 98% 2% caries yes no 17% 39% 28% 16% hard medium soft never noticed 22% 78% plaque 47% 53% calculus 60% 32% 8% horizontal vertical circular fig. 2: sample distribution according to type of tooth brush fig. 3: sample distribution according to direction on tooth brushing j bagh college dentistry vol. 29(3), september 2017 how much do oral and maxillofacial surgery and periodontics 34 bleeding gingiva and the reason ninety three percent (93%) of the patients reported gingival bleeding, when they asked about the reason behind such bleeding only 5% answered by poor oral hygiene, 26% due to brushing, 6% due to forceful brushing, 2% due to genetically weak gingival tissue, while almost third of the sample 29% believed it was due to microbial infection, 5% due to smoking, 2% due to food debris, 5% reported that dental calculus is the reason and the rest 21% answered by (i don’t know) (table4). patterns of dental visits and dental attendance patterns two percent (2%) visit the dentist on a 6 months interval, 1% once a year, 81% when having problem such as dental pain or broken tooth and 16% reported that had never been in a dental office before. sixty two percent (62%) of the sample received restorative treatment, 18 % asked for periodontal scaling and polishing,17 % to extract a badly caries or mobile tooth, 1% for orthodontic therapy, 2% for dental checkup (table 5). table 4: distribution of sample's answers regarding the cause of gingival bleeding cause of gingival bleeding no. % poor oral hygiene 21 5 brushing 115 26 force-full brushing 26 6 weak gingival tissue 8 2 infection 130 29 smoking 21 5 food debris 8 2 calculus 23 5 i do not know 94 21 total 446 100 table 5: sample distribution according to pattern of dental attendance and type of treatment received in the last 12 months pattern of dental attendance no. % treatment received in the last 12 months no. % every 6 months 12 2 dental filling 254 62 once a year 4 1 periodontal scaling 72 18 only in problems 390 81 tooth extraction 68 17 never 76 16 orthodontic 4 1 total 482 100 checkup 8 2 total 406 100 reason for seeking periodontal treatment according to the patients answers, not surprisingly 80% of the patients asked for periodontal therapy for esthetic reasons only having no awareness at all about the other consequences of periodontal diseases. five percent (5%) for stopping the gingival bleeding, 4% for calculus removal, 2% to get rid of the halitosis, 2% to treat the gingival infection,6% to save the rest of the teeth from falling (table 6). table 6: sample answers' distribution regarding the reason of seeking periodontal therapy discussion the vast majority of the sample (92%)reported a daily pattern of tooth brushing, a result close to those obtained in similar studies in saudi arabia, kuwait and china (9-11) but less than those obtained from iran and india (12,13). while twice-a-day tooth brushing which is the recommended brushing frequency by ada became an established practice in industrialized countries (14), in the present study it was reported by only 20% of the sample in accordance with results obtained from other studies in india and china (11,13,15) but far less than the percentage in kuwait that reached up to 62% (10). sixty percent (60%) of the sample used the traditional horizontal method in tooth brushing which has detrimental consequences such as dental abrasion and gingival recession and this is in accordance with other studies' results (11,13). reason for seeking periodontal therapy no. % calculus removal 20 4 stopping the gingival bleeding 23 5 esthetics 368 80 treating the gingival inflammation 12 2 halitosis 12 2 saving the rest of teeth from falling 29 6 total 482 100 j bagh college dentistry vol. 29(3), september 2017 how much do oral and maxillofacial surgery and periodontics 35 only 23% of the patient received instructions on tooth brushing from their parents with the mother being the main educator. such low percentage reflects the neglection and the lack of the parental guidance that result in relatively large number of children presenting clinical signs of gingivitis in iraq and worldwide (4,16-17). these findings highlights the impact of parents and the mother specifically on building the growing child perception of oral hygiene and the importance of the females continuous education about general and oral health during different stages of her life (child, teenager, pregnant and mother) in order to pass correct information and practices to their children (18). twenty eight percent (28%) of the sample used the soft type tooth brush similar to zhu et al.'s subjects (11) where 27% of the sample chose the soft type brush and explained the reason that this type would not hurt their gingival tissue during brushing. sixteen percent (16 %) of the sample did not have any idea about the types and specifications of the tooth brush , a proportion less than jain et al.’s sample where 50 % did the same. nearly two third of the sample (77%) did replace their tooth brush, less than the half (41%) replaced it each 3 months which is the recommended period for tooth brushing replacement as the bristles become frayed and worn with use and cleaning effectiveness will decrease according to the ada's recommendations (19). it is proved evidence that periodontal diseases are preventable by the means of self-performed good oral hygiene but first the population must be well informed in order to translate the acquired knowledge into actions. surprisingly 84% of the sample visited the dentist in the last 12 months out of them only 4% reported receiving information about the oral hygiene measures from their dentist, such finding reveals that a large proportion of the dentists pay little or no attention to the importance of patient education and motivation and neglect the right of the patients in devoting adequate time by the dentist to provide information regarding periodontal diseases etiology, signs, treatment options and preventive procedures. many dentist reported that it’s the time factor that prevents them from educating their patients, to overcome such obstacle it’s advisable to utilize the variety of educational and motivational tools available in the dental office such as the before and after treatment pictures, educational video on a tv screen, dental illustration posters, a take home instruction brochures and recently with the communication facilities provided by the social media, the dental office's page or online site can be used for the dental education purpose a facility saving the dentist time and providing the patients with adequate knowledge and updates. brushing alone is not sufficient for adequate plaque removal as clinical trials revealed that brushing alone would leave up to 40% dental plaque in the interdental spaces which is a clear indication for including the interdental aids in the daily oral hygiene routine (1,20). interdental aids usage by the patients was reported by 42% exceeding the 11.8 % in kuwait (10), regarding the type the majority used the dental floss 52% followed by the tooth picks with a percentage of 43% while only 5% used interdental brush. tongue coating is one of the local causes for halitosis due to the volatile sulphur compounds produced by microbial film residing between the filliforms papillae. coating removal is achieved by tongue scrapping with a scrapper or dental brush. in this study, only 22% of the sample cleaned their tongue similar a close proportion to jain's et al. result (13). mouthwash as adjunctive oral hygiene aids was used by only 37% of the patients exceeding jain's result (13). mouthwash advantage as reported by the patients was to prevent halitosis by 95% and provision of additional cleaning as reported by 5% of the sample. the knowledge level of respondents in regards to dental caries, dental plaque and calculus was assessed. 98% of the sample were familiar with dental caries and identifying it by the black cavity formed in the teeth which may cause severe pain if left untreated, 47% identified the dental calculus as the harmless whitish-yellow hard deposit on the tooth surfaces, while only 22% knew what is the dental plaque which is the primary causative factor of periodontal diseases (1). such low level of knowledge regarding dental plaque was also observed by taani in jordanians adults (21). the huge gap between the knowledge level of dental caries and that of calculus and plaque is explained by multiple reasons first, most of the dental education is directed towards dental caries, its consequences such as (severe pain, swelling, abscess and tooth loss) and its prevention by proper tooth brushing and dietary modification, second, patients are aware that the tooth is )carious( once a visible black cavity is formed while most of them are unaware of the early signs of gingivitis and periodontitis such as bleeding on provocation. third and last is the symptomatic nature of dental caries versus the silent nature of periodontal diseases . the gap between the dental calculus and dental plaque is mainly due to the visibility of the calculus and its rough surface , its affect the esthetic while the dental plaque which is a soft j bagh college dentistry vol. 29(3), september 2017 how much do oral and maxillofacial surgery and periodontics 36 layer with whitish to yellowish color is wrongly identified by the patients as a food remnants rather than a microbial community forming on the teeth surfaces. despite the fact that no clinical examinations were performed in this study and therefore no direct verification of clinical signs reported by the sample was done, self-reported oral health complaints can reflect the magnitude of certain oral health treatment and prevention needs, therefore; self-assessment still valuable in epidemiological studies of oral health (22). although 69% of the sample reported a daily pattern of tooth brushing, self-reported gingival bleeding was reported by 93% of the sample exceeding the 34.4% in kuwait (10) and the 40% in india (13). such high results are in agreement with studies of gilbert et al. (23), this can be explained by either the sample reported a false positive answers, a common problem in questionnaire based survey, or the ineffectiveness of the brushing technique performed by the sample. the patients' explanations for gingival bleeding reflected clearly the misperception of periodontal diseases and lack of awareness as only 5% reported poor oral hygiene as a causative factor, 29% though it’s a microbial infection and tried to treat it by antibiotics, 26% believed it is due to brushing itself since their gingiva bled upon brushing,6% due to forceful brushing, those are the patients with already inflamed gingiva that bled upon contact with the tooth brush. two percent (2%) thought it is due to remaining food debris after meals and similar proportion though it is due to genetically weak gingival tissue, 5% due to smoking, 5% due to the dental calculus and that what make them seek periodontal treatment, the remaining 21% were completely unaware nor having any explanation on the cause behind the bleeding gingival tissue. compliance with regular dental visits was extremely low where only 3% of the sample visit the dentist on a regular interval, 81% of the sample visited the dentist only when they had a dental pain similar findings were reported in lithuania by petersen et al. (24) but exceeding the 69.7% in syria (25) and the 54% in india (13). the question regarding the reason for seeking periodontal treatment reflected the low level of the general population education and periodontal awareness regarding the early signs and consequences of the periodontal diseases as 80% answered that the reason for seeking periodontal therapy was to restore the esthetics of their smile. conclusions the public periodontal awareness and knowledge is still poor in iraq, the solution for such problem require shared resources and multiple approaches. currently, in iraq in order to implement oral disease prevention programs, multiple factors must be taken into consideration including: the increased urbanization, changing in the demographic and socio-economic status, increased number of illiteracy, increased numbers of orphans, lack or difficulty in delivering health services. all of the mentioned above require the construction of a periodontal health awareness and community 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oral health behaviour among a sample of schoolteachers, physicians and nurses in the syrian arab republic. eastern mediterranean health j 1997; 3(2): 258262. الخالصة الدراسة هاجراء هذ استدعى العراقين البالغين ودرجة الوعي بامراض اللثة لدى الفم بصحة العناية ندرة المنشورات بشأن مدى: خلفيةال بصحة ى العنايةمد تقييم هدفت هذه الدراسة الى .األبحاث من لمزيد أجل تقييم مستوى الوعي في المجتمع وتوفير بيانات تكون اللبنة من .ينالعراقي البالغين من عينة والوعي بامراض اللثة في الفم .البالغين من 055 إلى ذاتيا االستبيان توزيع تم :الموادوالطرق من العينة يمارس تنظيف االسنان ٪24. الدراسةاستبيان في 284على العينة, بعد االقصاء تم ادراج استبيان 055تم توزيع :النتائج حول العناية الصحي يحصل على التثقيف لم العينة من ٪62، تباينمنهم انهم يقومون بذلك يوميا و لكن بتكرار م ٪62بالفرشاة ،ذكر بنسبة ألسنانا تنظيف ما بينوسائل واستخدمت األفقي، التنظيف نصف العينة يستخدم طريقة من يقرب مصدر،ما أي بالفم و االسنان من بينما تنظيف اللسان لم يكن ٪73 استخدم بنسبة الفم , غسول ٪04 األكثرشيوعا هوالنوع األسنان تنظيف و كان خيط العينة من 24٪ ناألسنا تسوس أن حين في األسنان الجرثومية لويحة ماهي اليعرفون العينة من ٪38 .مارسه العينة من فقط ٪44 حيث أن مألوفا المتدنية كونها العامل الفم نظافة إلى فقط أشار ٪0 نزف من اللثة مع وجود ٪27 ذكر. ٪28 من جميع العينة يقرب ما قبل معروف من .اللثة جمالية هواستعادة العينة من ٪85 لدى اللثة عالج عن للبحث الدافع. المسبب لجهود و تبني ظافر ات تطلبي المشكلة لهذه والحل العراق، في ضعيفا اليزالوالمعرفة فيما يخص امراض اللثة العام الوعي:االستنتاجات .متعددة مناهج .العراقيين،البالغين الموقف من نظافة الفم و الوعي بامراض اللثة،تنظيف االسنان بالفرشاة :الرئيسية الكلمات j bagh college dentistry vol. 29(3), september 2017 how much do oral and maxillofacial surgery and periodontics 38 appendix (1) ةالوعي بنظافة الفم و امراض اللث استمارة تقييم اسم المريض: العمر: الجنس: المهنة: التحصيل الدراسي: العنوان: الرجاء من المشتركين االجابة على جميع االسئلة و اختيار جواب واحد فقط لكل سؤال و كتابة بقية االجوبة بخط واضح. هل تقوم بتنظيف اسنانك باستعمال الفرشاة ؟ نعم كال مرة يوميا مرتان يوميا ثالث مرات يوميا كم مرة تقوم بتفريش اسنانك ؟ بين الحين و االخر من علمك كيف تعتني بنظافة فمك؟ ما نوع فرشاة اسنانك )ناعمة, متوسطة , خشنة( ؟ دائري باي اتجاه تقوم بتفريش اسنانك ؟ افقي عمودي هل تقوم بتبديل فرشاة اسنانك؟ نعم ال ما هي المدة التي تقوم فيها بتبديل فرشاة اسنانك ؟ عندما تصبح غير صالحة لالستعمال كل ثالثة اشهر كل ستة اشهر مرة سنويا هل تستعمل ادوات تنظيف ما بين االسنان ؟ نعم ال االسنان عيدان االسنان فرشاة ما بين االسنان ما هو النوع الذي تستعمله؟ خيط هل تقوم بتنظيف لسانك؟ نعم ال ماذا تستعمل لتنظيف اللسان ؟ فرشاة االسنان كاشطة اللسان هل تستعمل مضمضة الفم ؟ نعم ال لماذا تستعمل مضمضة الفم؟ هل تعاني من نزيف اللثة ؟ نعم ال برايك ماهو سبب نزيف اللثة ؟ ال هل تعرف ما هو البالك )الصفيحة الجرثومية(؟ نعم هل تعرف ما هي تكلسات االسنان )الجير(؟ نعم ال ال نعم هل تعرف ما هو تسوس االسنان ؟ ب االسنان ؟ لم ازره مسبقا فقط عندما اعاني من مشكلة ماهو معدل زيارتك لطبي مرة كل ستة اشهر مرة سنويا و تغليفها قلع االسنان شهرا الماضية ما هو نوع العالج الذي تلقيته؟ حشوات االسنان 21خالل ال تنظيف االسنان تقويم االسنان الفحص اخرى)يرجى الذكر( ؟ما هو سبب رغبتك في تنظيف اسنانك journal of baghdad college of dentistry, vol. 34, no.3 (2022), issn (p): 1817-1869, issn (e): 2311-5270 35 research article immunohistochemical evaluation for integrin binding sialoprotein on healing process of intrabony defect treated by bone sialoprotein mayada k. jaafar 1*, enas f. kadhim 2 1ph.d student, department of oral diagnosis, college of dentistry, university of baghdad. 2assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. . babalmoadham, p.o. box 1417, baghdad, iraq. * correspondence: kamelmayada6@gmail.com abstract: background: bone defect healing is a multidimensional procedure with an overlapping timeline that involves the regeneration of bone tissue. due to bone's ability to regenerate, the vast majority of bone abnormalities can be restored intuitively under the right physiological conditions. the goal of this study is to examine the immunohistochemistry of bone sialoprotein in order to determine the effect of local application of bone sialoprotein on the healing of a rat tibia generated bone defect. materials and methods: in this experiment, 48 albino male rats weighing 300-400 grams and aged 6-8 months will be employed under controlled temperature, drinking, and food consumption settings. the animals will be subjected to a surgical procedure on the medial side of the tibiae bone, with the bone defect repaired with absorbable hemostatic material in the control group (12 rats). the experimental group (12 rats) will be treated with local administration of 30 μl bone sialoprotein fixed by absorbable hemostatic sponge. after surgery, the rats will be slaughtered at 7, 14, and 28 days (four rats for each period). results: immunohistochemical analysis of bone sialoprotein by stromal cells reveal a substantial difference between the bone sialoprotein group and the control group. conclusion: the study concludes that local application of bone sialoprotein could be a successful therapeutic treatment for bone injuries; these findings are encouraging for future clinical use. keywords: bone defect, bone sialoprotein, bone. introduction the organic matrix of the bone, of which type-i collagen is the main component, which is largely responsible for bone repair. the involvement of non-collagenous proteins (ncps) in bone deformation, on the other hand, is not well understood. the majority of ncps are found in far lower concentrations than collagen and are known to influence bone mineralization, participate in cell signaling, and they have hormonal roles (1,2). ncps such as bone sialoprotein (bsp) , osteopontin ( opn)and osteocalcin (oc)have recently been shown to improve bone fracture resistance. diffuse damage arises in rat and human bone, allowing bone to disperse energy without producing overt fracture(3). non-collagenous extracellular bone-matrix proteins like bone sialoprotein are synthesized and secreted by osteoblasts. these non-collagenous matrix proteins are recognized to play a key role in the mineralization of the bone (4,5). these proteins found in the bone matrix have proven to be particularly valuable as osteogenic indicators(6,7). bone sialoprotein is a non-collagenous extracellular matrix protein that is highly expressed by osteoclasts, osteoblasts and hypertrophic chondrocytes in bone, and is especially abundant in primary bone formation locations(8,9). bone sialoprotein is a powerful mineralization nucleator as well as a matrix-associated signal that promotes osteoblast development and enhanced mineralized matrix synthesis(10,11) received date: 2-2-2022 accepted date: 1-3-2022 published date: 15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license. (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbc d.v34i3.3215 mailto:mayada6@gmail.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3215 https://doi.org/10.26477/jbcd.v34i3.3215 j. bagh. coll. dent. vol. 34, no. 3. 2022 jaafar and kadhim 36 it is abundantly expressed in bone by osteoblasts, osteocytes, osteoclasts, and chondrocytes (12,10). bsp overexpression boosts osteoblast-related gene expression and accelerates mineralized nodule formation in culture, despite the fact that it has long been thought to be a hallmark of late osteoblastic differentiation. in contrast, inhibiting the expression of osteoblast markers by reducing bsp expression in osteoblasts with particular shrna leads to a considerable reduction in matrix mineralization (10). materials and methods all experimental procedures are carried out in conformity with the baghdad college of dentistry's ethical principles. in this investigation, 48 albino male rats weighing 300-400 grams and aged 6-8 months will be employed under strict temperature, drinking, and food consumption controls. the animals are given an intrabony defect in the medial side of the tibiae bone, which is treated with absorbable hemostatic sponge in the control group (12 rats) and local application of 30 μl bone sialoprotein fixed by absorbable hemostatic sponge in the experimental group (12 rats). the rats were slaughtered seven, fourteen, and twenty-eight days following operation (four rats for each period in each group). the following materials were used in this study: 1bone sialoprotein (recombinant mouse bone sialoprotein 2/ibsp protein (histag) elabscience company . 2-ibsp polyclonal antibody elabscience company surgical technique a surgical procedure was performed on the animals. the procedure was done in a sterilized environment with a gentle technique. the dose of general anesthesia given to each animal was calculated based on its weight. intramuscular injections of xylazine 2% (0.4 mg/kg b.w.) and ketamine hcl 50 mg (40 mg/kg b.w.) were used to induce general anesthesia, as well as an antibiotic treatment with oxytetracycline 20% (0.7ml/kg) intramuscular injection. tibiae were shaved, and the skin was washed with a solution of ethanol and iodine, followed by an alcohol-soaked piece of cotton. an incision was created, and the skin was removed. the skin and fascia flap were mirrored after an incision was made. a hole of 1.8mm was drilled with a tiny spherical bur at a rotational speed of 1500 rpm using instrument drilling and continuous cooling with irrigated saline. the operation site was cleaned with saline solution after the hole preparation to eliminate debris from the drilling site. after the operation, the area was air dried, and then 30 μl bone sialoprotein was applied to the experimental group. the muscles were sutured using absorbable cat gut, then the skin was sutured. a local antibiotic was applied on the surgical site (tetracycline spray). results the presence of a brown cytoplasmic stain indicated a positive reading, whereas the absence of immunological reactions suggested a negative reading, depending on the positive and negative controls. analytical statistics mean, s.d., min., max., f-test, p-value were used to assess bone cell count as well as osteoblast, osteocyte, and stromal cells expressed by bone sialoprotein. results of immunohistochemistry in the control group, bone sialoprotein expression was as follows: at 7 days, immunohistochemical analysis of the control group revealed positive expression in osteoid tissue, osteoblast, and osteocyte. basal bone expression is negative (figure 1). bone sialoprotein expression is positive in osteoblast, osteocyte, and bone marrow stromal cells after 14 days (figure. 2). positive expression was detected in osteoblasts, osteocytes, and osteoclasts after 28 days. the new bone has a negative bsp expression (figure 3). bone sialoprotein expression in the bone sialoprotein-treated group: positive staining in the osteoid tissue is after 7 days. basal bone expression is negative (figure 4). a positive dab stain for bsp was seen in stromal, osteoblast, and osteocyte cells after 14 days (figure 5). j. bagh. coll. dent. vol. 34, no. 3. 2022 jaafar and kadhim 37 bsp immunohistochemistry expression in osteoblasts and osteocytes after 28 days. bsp expression was negative in mature bone, which contain several tiny haversian canals (figure. 6). statistical analysis revealed a high significant value for bone sialoprotein group in comparison to control and in periods (7, 14, and 28 days) as indicated in table (1). for positive expression of bone sialoprotein by stromal cells in study groups. positive expression of bone sialoprotein by osteoblasts, osteocytes, and osteoclasts, as determined by the following statistical analysis are as follow: (see table (2). in 7 days, osteoblast and osteocyte levels were highly significant, while osteoclast levels were nonsignificant. in 14 and 28 days, osteoblast ,osteocyte and osteoclast were highly significant. table (1) : descriptive statistics of the positive stromal cells expressed by bone sialoprotein and groups’ difference in each duration. duration groups descriptive statistics comparison mean s.d. min. max. f-test p-value 7 days cont 17.915 1.799 15.33 19.5 36.963 0.000 b 25.958 1.159 24.33 27 14 days cont 8.500 1.443 7.25 9.75 84.990 0.000 b 17.375 0.924 16 18 28 days cont 4.625 0.750 4 5.5 14.678 0.000 b 8.125 0.854 7 9 figure (1): view of 7 days interval of control group shows positive expression of bone sialoprotein in osteoid tissue (ot), osteoblast ( arrow), osteocyte cells (arrow heads) and shows negative expression in basal bone (bb). dab stain x40. figure (2): osteocyte (arrow heads) and osteoblast (arrows), bone marrow stromal cells (bmscs) show positive bsp expression in control group 14 days. negative expression in trabecular bone (bt) dab stainx40 figure (3): view of 4 weeks duration of control group showed mature bone contain positive expressed of osteocytes(arrow heads), osteoblast (arrow) and osteoclast ( red arrow).dab stain with counter stain hematoxylin x40 figure (4): immunohistochemical view shows positive bsp expression in osteoid tissue(ot) in bone sialoprotein group 7 days with negative expression in basal bone (bb) . dab stainx40 b b o t b b o t bmsc b t j. bagh. coll. dent. vol. 34, no. 3. 2022 jaafar and kadhim 38 table 2 : descriptive statistics of the positive bone cells expressed by bone sialoprotein and groups’ difference in each duration. duration cells groups descriptive statistics comparison mean s.d. min. max. f-test p-value 7 days ob cont 21.250 1.936 18.5 23 81.111 0.000 b 31.395 0.966 30.5 32.75 oc cont 19.408 1.045 18.33 20.8 41.176 0.000 b 24.458 1.030 23 25.33 ocl cont 0.173 0.022 0.15 0.2 0.358 0.785 b 0.200 0.115 0.1 0.3 14 days ob cont 20.188 1.841 18.25 22 10.378 0.001 b 15.208 1.567 13.33 16.5 oc cont 20.500 1.620 18.75 22.5 26.256 0.000 b 12.625 1.109 11.5 14 ocl cont 1.148 0.108 1 1.25 5.188 0.016 b 0.700 0.216 0.5 1 28 days ob cont 10.313 1.463 8.75 12 7.313 0.005 b 6.500 1.080 5 7.5 oc cont 10.208 2.347 7.5 13 5.683 0.012 b 6.500 1.225 5 8 ocl cont 0.450 0.091 0.35 0.55 5.419 0.014 b 0.200 0.082 0.1 0.3 discussion the goal of this study was to see how local application of bone sialoprotein affected experimentally produced bone defects in rats' tibiae. over the last decade, the rat has been employed in a considerable fraction of animal fracture investigations in major orthopedics research(13). figure (5): immunohistochemical view for bone sialoprotein group 14 days show positive expression to bsp in osteoblast (arrows) , osteocyte (arrow head) and osteoclast (red arrow).negative expression in bone trabeculae (bt). dab stainx40 b t figure (6): view after 28 days duration of bone sialoprotein with positive expression of osteocytes(arrow head),) and osteoblast (arrows). dab stain with counter stain hematoxylin x40. b b j. bagh. coll. dent. vol. 34, no. 3. 2022 jaafar and kadhim 39 proliferation, apoptosis, adhesion, migration, angiogenesis, and ecm remodeling could all be influenced by bone sialoprotein(14). in a nude rat model, anti-bsp ab was also found to prevent osteolysis while stimulating bone growth(15,16). bone sialoprotein expression and localization were brownish in color in all groups, showing that there was expression of bone sialoprotein; positive cells were found at osteoblast, osteocyte, and osteoclast in all groups. the new bone matrix and the surrounding area of the resorptive lacunae showed high positive expression for bone sialoprotein. this was in line with the findings of(17,18), and(19), who claimed that strong bsp staining in newly produced bone in swine fetuses' mandibular alveolar bone. in this investigation, bone sialoprotein was expressed in a large number of osteoblasts, osteocytes, and a small number of osteoclasts in the space of a bone defect for 1 week in all groups. this conclusion matched with(20), who showed significant staining of osteoblasts and osteocytes associated with newly produced bone during periodontal regeneration in dogs. while disagreeing with(21) who claimed that faint bsp staining in osteoblasts present in embryonic rats' mandibles. in the experimental group, however, there was a decrease in bone sialoprotein expression over time. this finding is consistent with (22) who found that newly formed bone had more intense bsp staining at 1 week, whereas mature bone was weakly stained, and osteoblasts and osteocytes had higher bsp positivity at 1 week, which gradually decreased with time when staining was mild and limited to the lacunae. also(23) found that the bone sialoprotein mrna signal was strongest in osteoblasts along the surface of woven bone trabeculae in actively growing bone tissue, and that it decreased with bone growth. these findings suggest that while bone sialoprotein is necessary for de novo creation, it is less important for bone growth because growth is still occurring. conclusion the findings of this investigation reveal that bone sialoprotein has the potential to aid in the mending of bone abnormalities. conflict of interest: none. references 1. prodinger p m, bürklein d, foehr p, kreutzer k, pilge h, schmitt a, ... & tischer t. improving results in rat fracture models: enhancing the efficacy of biomechanical testing by a modification of the experimental setup. bmc musculoskeletal disorders, 2018; 19(1): 243. 2. oury f, khrimian l, denny c a, gardin a, chamouni a, goeden n, ... & suyama s. maternal and offspring pools of osteocalcin influence brain development and functions. cell, 2013; 155(1): 228-241. 3. nikel o, poundarik a a, bailey s, & vashishth d. structural role of osteocalcin and osteopontin in energy dissipation in bone. journal of biomechanics. 2018; 80: 45-52. 4. aubin je. osteogenic cell differentiation. in: 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regeneration in osteopenic rats. 2014; 22: 541-553. 23. chen j, shapiro h s, sodek j j j o b & research m. 1992. developmental expression of bone sialoprotein mrna in rat mineralized connective tissues. 1992; 7: 987-997. لتقييم التطبيق الموضعي لبون سيالوبروتين في تعزيز شفاء العظام دراسة كيميائية مناعية نسيجية لبون سيالوبروتين المرتبط بانتجرين العنوان: على الجرذان 2 ايناس فاضل كاظم , 1ميادة كامل جعفر الباحثون: المستخلص: j. bagh. coll. dent. vol. 34, no. 3. 2022 jaafar and kadhim 41 من العظمى الغالبية استعادة يمكن ، التجدد على العظام لقدرة نظًرا. العظام أنسجة تجديد يتضمن متداخل زمني جدول مع األبعاد متعدد إجراء هو العظام عيب شفاء: الخلفية أجل من بون سيالوبروتينل الكيميائي المناعي النسيجي التقييم فحص هو الدراسة هذه من الهدف كان. الصحيحة الفسيولوجية الظروف ظل في حدسي بشكل العظام تشوهات . العظام في فجوة عظمية طبقت على الجرذان التئام على بون سيالوبروتينل الموضعي التطبيق تأثير تحديد خضعت لظروف متماثله من حيث أشهر 8-6 بين أعمارهم وتتراوح جرام 400-300 تزن التي البيضاء الجرذان ذكور من 48 استخدام سيتم ، التجربة هذه في: والطرق المواد والشراب حرارةال درجة الطعام في . واستهالك جراحية لعمليه خضعت القصبة الحيوانات عظم من اإلنسي قابلة ،. الجانب جراحية بإسفنجة عولجت العظمية الحفرة العظمية عولجت بـ ( جرذ 12) التجريبية المجموعة(. جرذًا 12)مجموعة السيطرة في لالمتصاص ميكرولتر من بون سيالوبروتين مثبت بإسفنجة جراحية قابلة 30الحفرة (.فترة لكل فئران أربعة) يوًما 28 و 14 و 7 في الفئران ذبح تم الجراحة بعد . المتصاصل . السيطرة ومجموعة بون سيالوبروتينال مجموعة بين جوهري اختالف وجود خاليا انسجة نخاع العظم في بون سيالوبروتينل الكيميائي المناعي النسيجي التقييم أظهر: النتائج في السريري لالستخدام مشجعة النتائج هذه . العظام إلصابات ناجًحا عالجيًا عالًجا يكون أن يمكن بون سيالوبروتين ل الموضعي التطبيق أن إلى الدراسة خلصت : االستنتاج .المستقبل . بون سيالوبروتين ، عيوب العظام: المفتاحية الكلمات 29nibal f.docx j bagh college dentistry vol. 28(3), september 2016 microleakage of pit pedodontics, orthodontics and preventive dentistry 172 microleakage of pit and fissure sealants after using different occlusal surface preparation techniques: an in vitro study nibal mohammed hoobi, b.d.s., m.sc. (1) abstract background: the marginal seal is essential for sealant success because penetration of bacteria under the sealant might allow caries onset or progression. the aim of the present study was to estimate and compare the microleakage of pit and fissure sealant after various methods of occlusal surface preparation. materials and methods: thirty non-carious premolars extracted for orthodontic reasons were equally divided into three groups. in group one, occlusal fissures were opened with round carbide bur, in group two, occlusal surfaces of the teeth were cleaned with a dry pointed bristle brush and samples of group three were cleaned with a slurry of fine flour of pumice in water using rubber cup. then fissures of all teeth were etched using 35% phosphoric acid gel prior to placement of conseal f (sdi) light cured sealant, the teeth were thermocycled, then they were immersed in 1% methylene blue for 24hours. each tooth was sectioned bucco-lingually to detect the microleakage. results: different levels of microleakage were observed among various groups, highest level was recorded for brushing group followed by pumice group, while round bur samples showed the least microleakage when compared with other groups. statistically the difference was not significant between brushing and pumice groups, while it was significant between round bur and other groups conclusion: preparation of occlusal surface with round bur was very effective in reduction of microleakage in comparison with the traditional pumice slurry and bristle brush. keywords: microleakage, fissure sealant, conseal. (j bagh coll dentistry 2016; 28(3):172-177). introduction in preventive dentistry, many techniques are available for prevention of caries, such as plaque control, use of fluorides and pit and fissure sealants (1). the exceptional morphology of occlusal pit and fissures renders the mechanical way of debridement unapproachable as an average tooth brush bristles is too big to penetrate most of the fissures (2). difficult salivary access to these areas minimizing fluoride deposition and remineralization (3,4). besides the close proximity of fissure base to dentino-enamel junction enhance caries susceptibility of fissures by many times. accordingly, to prevent initiation of caries in these fissures, the conception of pit and fissure sealants was introduced (5). it is strappingly recommended in fortification against commencement of occlusal caries (6). the cariostatic properties of sealants are ascribed to the physical obstruction of the pit and fissures. this prevents colonization of pits and fissures with new bacteria and also prevents the infiltration of fermentable carbohydrate to any bacteria lingering in the pits and fissures (7). the current sealants can be differentiated based on filler content (filled or unfilled), appearance (clear, tinted, opaque, or color changing), mode of setting initiation (chemical or visible light cure), and fluoride release (8). (1) lecturer, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. the requirements of an ideal material include biocompatibility, low viscosity, low solubility, esthetically acceptable and rationally visible to easere-evaluation (6). the success of pit and fissure sealants over long-time spans depends on an efficient marginal seal, retention and integrity (9). lack of sealing permits the incidence of microleakage which is the passage of bacteria, fluids, molecules and ions throughout the toothmaterial interface, which is able to encourage caries progression beneath the sealants (10,11). this in turn depends not only on the physical, chemical or biological acceptance of the material used as a fissure sealants, but should be depends also upon optimal clinical procedure by the dentist including cleaning and preparing the tooth surface to receive the sealant placement. remaining substance in the fissure, air trap and fissure geometry itself lead to restraining of sealant penetration, making it essential to have an excellent clinical procedure (12). to improve sealing capability of sealant materials numerous different methods of sealant application were investigated. it was found that the use of bonding agents can reduce the microleakage (13). some studies indicated that acid etching show significantly less microleakage when compared to laser etching (14), other studies concerned with use of air abrasion to improve marginal seal (15-17). because there is no published iraqi study available concerning occlusal surface preparation before acid etching and because pit and fissure j bagh college dentistry vol. 28(3), september 2016 microleakage of pit pedodontics, orthodontics and preventive dentistry 173 sealants are fundamental part of preventive dentistry that can play a considerable role in alleviating the oral health status, hence this study was designed to compare in vitro the efficiency of different methods of cleaning and preparing occlusal fissures to accept sealant so as to make them more acceptable and dependable. materials and methods thirty caries-free first premolars extracted for orthodontic purposes from young age patients ranged from 12-15years old of age. permission to conduct this study in the college of dentistrybaghdad university was obtained. the lack of caries was detected according to the clinical parameters using a sharp explorer and visual examination (7). the samples were cleaned under tap water and any periodontal tissues attached to the roots of the teeth were removed with periodontal scalar spreceding to their preservation in thymol. they were randomly divided to three groups of 10 teeth each for receiving fissure sealant conseal f which chemically based on udma (urethane dimethacrylate).the groups were as follows: group i: opening of fissures with round carbide bur. the fissures were opened with a new round carbide bur (1∕4) in a high speed hand piece (250,000 rpm) to approximately the width and the depth of the bur diameter (0.5mm). group ii: brushing only. the fissures were cleaned with a dry pointed bristle brush (buffalo dental manufacturing co., inc.) using a low speed hand piece for approximately 10 seconds. group iii: application of pumice slurry. the fissures were cleaned with a slurry of fine flour of pumice (amorphous aluminum silicate, patterson dental company inc.) in water (5g∕4ml water) using rubber cup in low speed hand piece for approximately 10 seconds. succeeding to fissure preparation, the fissures were etched using 35% phosphoric acid gel for 30 seconds, the specimens were then rinsed for 10 seconds using air water spray of three way syringe and dried using oil free compressed air with a hand pump air pressure syringe. following ensuring a frosted appearance of the enamel at the fissure entry, conseal f pit and fissure sealant was placed on the surface according to manufacturer instructions. to evade bubbles and air entrapment, a 0.5mm-tip diameter periodontal probe was used to shove the sealant into the fissure and any obvious voids were removed with the tip of the probe. the sealant was, after that, cured for 20 seconds using visible light curing unit. the samples were incubated for 24 hours in distilled water at room temperature (18). all the samples were then thermocycled by hand between two water baths (19), the temperature of water baths were 5◦c and 55◦c with a dwell time of 30 seconds in each bath (18,20), and the number of cycles in use was 15 cycles (13). two layers of acid resistant varnish were applied to all tooth surfaces excepting for 1 mm diameter contiguous the sealant, the apices of the roots were sealed with sticky wax to prevent dye penetration from anywhere except via the sealanttooth interface. the teeth were immersed in1%aquous solution of methylene blue dye for 24 hours; subsequently they were washed to remove the surplus dye (21). the varnish and sticky wax were scraped off and samples were implanted in acrylic blocks up to cement-enamel junction. approximately 1.5 mm-thick sections were made longitudinally with a water cooled diamond disk in buccolingual direction. the sections were then kept dry and examined for microleakage using motic microscope with digital camera (18). the extent of microleakage was scored by single specialist observer using a ranked scale method (22). microleakage scores score criteria 0: no dye penetration 1: dye penetration into the occlusal third of the enamel-sealant interface 2: dye penetration into the middle third of the interface 3: dye penetration into the apical third of the interface the data were analyzed using spss (version 20). the (anova) test and lsd test were performed. the significance level (p-value) was set at 0.05. results the dye penetration represent the microleakage which was presented by scores for all groups .the frequency of scores for each group was shown in figure 1. according to these results the highest frequency of score 0 was within group 1(bur group) and the lowest frequency of such score was with group 2(brushing only group).the highest microleakage score 3 was recorded in group 3 (conventional pumice prophylaxis group) only. table (1) presents the arithmetic mean and standard deviation of microleakage scores. the lowest mean of microleakage was for bur group which is 0.2, then pumice with 0.9, while the j bagh college dentistry vol. 28(3), september 2016 microleakage of pit pedodontics, orthodontics and preventive dentistry 174 highest mean appeared in brushing group which was 1. anova was used to compare between various groups for microleakage as illustrated in table 2, the three different groups showed significant difference between them since p< 0.05. least significant difference (lsd) test was needed to show where the significance had occurred between groups as shown in table 3.the result demonstrated that microleakage score was lower significantly for bur group than brushing and pumice groups ,while the difference between brushing group and pumice group was not significant. the dye penetration and microleakage scores were determined by microscope examination, and some photographs were taken and presented in figures 2, 3, 4 and 5. figure 1: the frequency of dye penetration score for each group table 1: mean and standard deviation of the microleakage scores for all groups groups no. mean ±sd bur group 10 0.2 0.421 brushing group 10 1.0 0.666 pumice group 10 0.9 0.999 table 2:anova test among different groups sum of squares df mean square f-value p-value between groups 3.8 2 1.9 3.538 0.04* within groups 14.5 27 0.537 total 18.3 29 *significant (p <0.05) table 3: least significant difference (lsd) between each two groups group 1 group 2 mean difference sig. bur group brushing group 0.8 0.021* pumice group 0.7 0.042* pumice group brushing group 0.1 n.s. *significant (p<0.05) 0 1 2 3 4 5 6 7 8 9 group 1 group 2 group 3 score 0 score 1 score 2 score 3 j bagh college dentistry vol. 28(3), september 2016 microleakage of pit pedodontics, orthodontics and preventive dentistry 175 figure 2: photograph viewof ground sectionshows clear enamel without dye penetration (score 0) figure 3: photograph view of ground section shows occlusal one third of dye penetration (score1) figure 4: photograph view of ground section shows dye penetration into middle third of the interface (score 2) figure 5: photograph view of ground section shows apical penetration of the dye (score3) discussion the degree of the occlusal caries reduction by fissure sealant depends on its ability to remain strongly adherent to the tooth and produce a tight seal at the tooth-sealant interface. that can be achieved by diverse enamel surface preparation techniques (23,24). conseal f fissure sealant which is resin based, fluoride releasing and light curable was elected in this research because it has low shrinkage capability, the filler load is seven percent only to bestow low viscosity value and facilitate better penetrability into pits and fissures and it is commercially available in iraq, so we can apply the result of this study for the benefit of the patients (25). the in vitro nature of the study permitted the control of numerous variables that could not be controlled under in vivo condition and to carry out thermocycling which simulate stress caused by thermal difference (13,26). all the tested groups in this study presented some extent of microleakage and this approved with previous studies (3,27), this is for the reason that complete penetration of sealant into complicated fissure system is intricate due to many reasons, one of them is the phenomenon of closed end capillaries or isolated capillaries. some lateral fissures arise from the main fissures also fail to be full with sealants in addition to other variables like fissure morphology and preparation method of the fissures (1,28). the major finding of this study was that the bur preparation gave less microleakage and finest result. several causes can be proposed to explain this results, fissures were widened and deepened, organic materials and plaque were removed (29), offer more surface area to hold the sealant and a constant plug of sealant is obtained which present more wear resistance (30). enamel fissures penetration of the sealants is enhanced when fissures are enlarged by bur and acid etching used (3). enlargement of fissures produce difficulty for implanting a steady microflora and creating a closed system for the development of caries. consequent sealant placement decreases the number of viable bacteria up to hundred percent 100% (31). the significant difference between both brushing and pumice, and bur preparation can be explained by that the remaining debris and pellicle may not be removed from the base of the fissures, prevent enamel conditioning and decrease the resin penetration (32-35). cleaning and preparation in these procedures is restricted to the cuspal inclined planes only and not to the bottom of the fissures (34). the width of j bagh college dentistry vol. 28(3), september 2016 microleakage of pit pedodontics, orthodontics and preventive dentistry 176 the bristles is too large to go through the orifice of most fissures (36). pumice particles become wedged impacted into the fissures, become incorporated into the sealants, thus changing its micromechanical bond, resulting in greater microleakage (33,34,37). following proper technique of sealant application can increase the micromechanical interlocking between the resin and the enamel and this in turn will diminish the microleakage and improve the efficiency of sealant in preventing dental caries. references 1. prabhakar ar, murthy sa, sugandhan s. comparative evaluation of the length of resin tags, viscosity and microleakage of pit and fissure sealantsan in vitro scanning electron microscope study. contemporary clinical dentistry 2011; 2(4): 324-30. 2. feldens eg, felden ca, de araujo fb, souza ml. invasive pit and fissure in primary molars: a sem study. j clinpediatr dent 1994; 18:187-90. 3. salama fs, al-hammad ns. marginal seal of sealant and compomer materials with or without enameloplasty. int j pediatr dent 2002; 12: 39-46. 4. el-housseiny aa, sharaf aa. evaluation of fissure sealant applied to topical fluoride treated teeth. j clin pediatr dent 2005; 29: 215-9. 5. burrow mp, burrow jf, makinson of. pits and fissures: relative space contribution in fissures from sealants, prophylaxis pastes, and organic remnants. aus dent j 2003; 48: 175-9. 6. limeback h. comprehensive preventive dentistry.1st ed. john wiley and sons ltd; 2012.p.287. 7. sanders bj, feigal rj, avery dr. pit and fissure sealants and preventive resin restorations. in: mc donald re, avery dr, dean ja (eds). dentistry for child and adolescent. 8th ed. new delhi: elsevier; 2005. p. 355. 8. damel s. text book of pediatric dentistry. 3rded. new delhi: arya (mede) publishing house; 2009. 9. gomes-silva jm, torres cp, contente mm, oliveira ma, palma-dibb rg, borsatto mc. bond strength of a pit-and-fissure sealant associated to etch-and-rinse and self-etching adhesive systems to salivacontaminated enamel: individual vs. simultaneous light curing. braz dent j 2008; 19: 341-7. 10. larson td. the clinical significance and management of microleakage. north dent 2005; 84(1): 23-31. 11. pardi v, sinhoreti ma, pereira ac, ambrosano gm, meneghimmde c. in vitro evaluation of microleakage of different materials used as pit-andfissure sealants. braz dent j 2006; 17: 49-52. 12. simonsen rj. pit and fissure sealant: review of the literature. pediatr dent 2002; 24: 393-410. 13. el-mosawi a. an evaluation of three fissure sealants microleakage with presence or absence of bonding agent through time intervals. a master thesis, college of dentistry, baghdad university, 2012. 14. vijayaraghavan r, raov, reddyn, krishnakumar r, sugumaran dk, mohan g. assessment and comparison of microleakage of a fluoride-releasing sealants after acid etching and er:yag laser treatment-an in vitro study. contemprary clinical dentistry 2012; 3(1): 64-8. 15. hatibovic-kofman s, butler sa, sadek h. microleakage of three sealants following conventional, bur, and air-abrasion preparation of pits and fissures. int j paediatr dent 2001; 11: 409-16. 16. mazzoleni s, de francesco m, perazzolo d, favero l, bressan e, ferro r, et al. comparative evaluation of different techniques of surface preparation for occlusal sealing. eur j paediatr dent 2007; 8: 119-23 17. reddy pv, hugar sh, deshpande sh, shigli a, shirol d, poonacha ks. the evaluation of different methods viz. acid etch and by air abrasion on retentively of fissure sealants after 6 months: a clinical study. contemporary clinical dentitry2014; 41(1):16-21. 18. agrawal a, shigli a. comparison of six different methods of cleaning and preparing occlusal fissure surface before placement of pit and fissure sealant: an in vitro study. j indian society pedodontics and preventive dentistry 2012; 30(1): 51-5. 19. amaral fl, colucci v, palma-dibb rg, corona sa. assessment of in vitro methods used to promote adhesive interface degradation: a critical review. j esthet restor dent 2007; 19(6): 340-53. 20. al-rubayi s. fine evaluation of microleakage in two different types of composite resins with and without mega filler glass ceramic insert. a master thesis, college of dentistry, baghdad university, 2003. 21. smith la, o'brain ja, retief dh, marhman jl. miroleakage of two dentinal bonding restorative systems. j dent res 1988; 67: 309. 22. grande rh, ballester r, singer j, santos jf. microleakage of a universal adhesive used as a fissure sealant. am j dent 1998; 11(3):109-13. 23. kanellis mj, warren jj, levy sm. a comparison of sealant placement techniques and 12-month retention rates. j public health dent 2000; 60: 53-6. 24. kim j, shin c, park k. long-term evaluation of sealants applied with an invasive technique. am j dent 2008; 6: 21. 25. fernands k, chalakkal p, ataide i, pavaskar r, fernandes p, soni h. a comparison between three different pit and fissure sealants with regards to marginal integrity. j conservative dentistry 2012;15(2):146-50. 26. atash r, vandenabbeele a. sealing ability of new generation adhesive systems in primary teeth: an in vitro study. pediatr dent 2004; 26: 322-8. 27. droz d, schilee mj, panight mm. penetration and microleakage of dental sealants in artificial fissures. j dent child 2004; 71: 31-44. 28. fuks ab, grajower r, shapira j. in vitro assessment of marginal leakage of sealants placed in permanent molars with different etching times. j dent child 1984; 50: 425-8. 29. shapira j, eidelman e, dr. odont. six-year clinical evaluation of fissure sealants placed after mechanical preparation: a matched pair study. pediatr dent 1986; 8: 204-5. 30. garcia-godoy f, de araujo fb. enhancement of fissure sealant penetration and adaptation: the enameloplasty technique. j clin pediatr dent 1994; 19: 13-7. 31. kramer fp, zelante f, simionato mr. the immediate and long term effects of invasive and non-invasive pit and fissure sealing techniques on the microflora in j bagh college dentistry vol. 28(3), september 2016 microleakage of pit pedodontics, orthodontics and preventive dentistry 177 occlusal fissures of human teeth. j pediatr dent 1993; 16: 108-12. 32. weaks lm, lescher nb, barnes cm, holroyd sv. clinical evaluation of the prophy-jet as an instrument for routine removal of tooth stain and plaque. j periodontol 1984; 55: 486-8. 33. garcia-godoy f, medlock jw. an sem study. of the effects of air-polishing on fissure surfaces. quintessence int 1988; 19: 465-7. 34. taylor lc, gwinnett aj. a study of the penetration of sealants into pits and fissures. j am dent assoc 1973; 87: 1181-8. 35. selecman jb, owens bm, johnson ww. effect of preparation technique, fissure morphology, and penetrability of pit and fissure sealants. pediatr dent 2007; 29: 308-14. 36. newbrun e. cariology. london: uk: quintessence publishing co. inc.; 1989. p. 315. 37. hatibovic-kofman s, butler sa, sadek h. microleakage of three sealants followed by conventional, bur and air abrasion preparation of pit and fissure. int j peadiatr dent; 2001; 11: 409-16. ameena f.doc j bagh college dentistry vol. 28(2), june 2016 a salivary α-amylase oral diagnosis 40 a salivary α-amylase level in relation to the oral health parameters among children in baghdad city ameena ryhan diajil, b.d.s., m.sc., ph.d. (1) lamia ibrahim sood, b.d.s., m.sc. (2) rasha abbas azeez, b.sc., m.sc. (3) abstract background: saliva is a specific bio-fluid with important biomarkers. analyzing any alternation in these markers could give valuable information, in relation to oral health status parameters. the aim of this study was to investigate the level of α -amylase in unstimulated whole saliva of healthy, primary school children in relation to some oral health parameters. materials and methods: a questionnaires consisted of demography and medical histories of participants were filled by children families. saliva samples were collected for 5minutes between 9:00 -11:00 am from 114 healthy students aged 6-13 years, divided into four age groups. flowrate, plaque and gingival index were assessed and dentition status was investigated by dmft/dmft using who criteria. salivary amylase was analyzed in unite per litter, using quantitative colorimetric amylase determination at 585nm. results: a significant positive correlation was found between age and salivary flow-rate, (r=0.362, p < 0.001). salivary α-amylase concentration increased significantly with age (p< 0.001). for each one year there is an increase in age, amylase level is expected to increase by 5.2 u/l. a male gender is expected to reduce salivary α -amylase level by 10.6 u/l compared to female, however the effect was not significant. gingival index was positively, although nonsignificantly associated with salivary α -amylase concentration. dmft showed a significant weak positive linear correlation with salivary amylase level (r=0.309, p<0.001), while deciduous teeth decay experience and plaque index were significantly and negatively associated with salivary amylase. conclusion: results emphasize the importance of salivary amylase, as a non-invasive biomarker in regulating oral and dental health status in children. key words: salivary α –amylase, unstimulated whole saliva, oral health parameters. (j bagh coll dentistry 2016; 28(2):40-46). introduction alpha-amylase is one of the principal salivary proteins, accounting for 10–20% of the total protein content (1). the main function of salivary alpha-amylase is the enzymatic digestion of carbohydrates through hydrolysis of starch to glucose and maltose with optimum ph of 6.77.0(2). it is known for its role in the breakdown of large insoluble starch molecules into smaller, soluble molecules. additionally, salivary alphaamylase has been suggested to inhibit the adherence and growth of bacteria to prevent bacterial attachment to oral surfaces and to enable bacterial clearance from the mouth (3), so it is important for the mucosal immunity in the oral cavity (4, 5). alpha-amylase is secreted by the salivary gland and pancreas and so present in saliva and serum. in the salivary gland, alpha-amylase is synthesized and secreted by highly differentiated epithelial acinar cells which make up more than 80% of the cells in the major salivary glands, mostly of the parotid glands (2). (1)assistant professor. department of oral diagnosis, college of dentistry, university of baghdad (2)lecturer. department of pop, college of dentistry, university of al-anbar (3) lecturer. department of basic sciences, college of dentistry, university of baghdad salivary alpha-amylase, secreted following activation of beta-adrenergic receptors, so it may measure the endogenous sympathetic activity. alphaamylase enzyme produced mainly by serous cells of the parotid gland followed by sublingual, submaxillary, and minor glands. typically, the concentration of amylase in human saliva ranges from 0.04 0.4 mg/ml (6) increases during food consumption and with stress (7). several lines of evidence showed that alphaamylase has multifunction in the oral cavity. the initial enzymatic digestion of dietary starch begins in the oral cavity with the release of maltose and maltodextrin, providing an abundant source of carbohydrate for oral bacterial nutrition. secondly, in addition to its hydrolytic activity, alpha-amylase binds to a selected group of oral streptococci, that may contribute to bacterial clearance and nutrition (8,9). the binding of alphaamylase to bacteria in solution may be considered protective if it leads to bacterial clearance from the oral cavity (5). the fact that alpha -amylase binds to teeth as a constituent of enamel pellicle play a role in modulating the adhesion of bacterial species to the teeth (8). it is well recognized that dental plaque is closely related to the most common oral diseases, dental caries and periodontal disease (10). formation of dental plaque is a complex process j bagh college dentistry vol. 28(2), june 2016 a salivary α-amylase oral diagnosis 41 includes the interaction between streptococci and the salivary protein alpha-amylase (11,12). in brief, salivary amylase contributes in at least three vital roles affecting biofilm: 1) hydrolysis of dietary starch, 2) binding to the tooth surface, and 3) binding to oral streptococci (13). considering age and gender, similar to other body organs, it has been clearly established that synthesis and secretion of enzymes in unstimulated saliva decrease with age (14,15). this has been supported by a study conducted by kalipatnapu et al. who showed that increase in salivary protein and amylase in both males and females up through middle age and then the concentration of these constituents remain unaffected through the rest of adult life (15). in the same study, males secrete more saliva than females, accordingly, they synthesize and secrete greater amounts of salivary protein and amylase compared to females. this study aimed to investigate alphaamylase level in unstimulated whole saliva of primary school children in relation to some oral health parameters in this group of children. materials and methods participants one hundred fourteen primary school students took part in this study. they were recruited from ashoorprimary school in baghdad/iraq. one class from each year of study was invited to take part in this study; six classes from year one to year six. the study was approved by the ethics committee of oral diagnosis department in the college of dentistry –university of baghdad. questionnaire distributed necessary permission was taken from school authorities and written informed consents were taken from the parents/guardians before the start of the study. a description about the purpose and aim of the study was performed for both school authorities and families of participants. the study was carried out using a structured questionnaire that was distributed in arabic language and sent to the families of the school children; completed by the parents /guardians and return back to the school. these questionnaires consisted of three parts; the first part was related to the demography of children regarding name, age, gender and year of study. the second part involved clinical oral examination that carried out under natural light using disposable plane mouth mirrors and who dental explorers for diagnosis of dental caries. oral hygiene and gingival health status was determined by plaque index (pi) (16), gingival index (gi) (17) and calculus index (ci) (18) by using periodontal probe. dentition status was also investigated by dmft, and dmft using who criteriaa (19). oral examination was performed by the same examiner. the third part of the questionnaire considered the child medical history. the questions were mainly closed –ended rather than open questions, thus to avoid the misunderstanding. inclusion criteria of the current study were children with informed consent from the parent or guardian. exclusion criteria were children having difficulty in opening the mouth, children who had taken antibiotics in the last month, those with systemic disease and children with orthodontic appliances. method of saliva collection: saliva collection was scheduled after the clinical examination. saliva was collected from all participants under the same conditions (20). the children were supervised and instructed to be comfortably seated with their head tilted slightly forward. additionally, they were instructed to swallow any saliva in their mouth, immediately before the collection started. in brief, saliva was allowed to accumulate in the floor of the mouth and to expectorate all saliva formed over 5 minutes period into the graduated sterile test tube. the saliva samples of all the participants were identified by a code number during the period of sample collection and processing. after the disappearance of the salivary froth, the salivary flow rate was estimated in millilitres per minutes. samples were stored at 80°c, until analysed. sampling sessions were limited to the hours between 9:00 and 11:00 am to minimize the effect of diurnal variations. quantitative colorimetric amylase determination at 585nm was used to estimate the concentration of salivary amylase (u/l) (21). enzychromtm α-amylase assay kit (ecam100). statistical analysis statistical analysis was performed with spss version 19.0. descriptive statistical analysis, student t-test, analysis of variance (anova) and linear and multiple linear correlation were used. a p-value of less than 0.05 was considered to indicate statistical significance. j bagh college dentistry vol. 28(2), june 2016 a salivary α-amylase oral diagnosis 42 results age, flow rate and salivary amylase level one hundred fourteen primary school students were enrolled in this study, 64 (56%) were females and 50 (44%) were males. the age ranged from 6-13 years with a mean of 9.1 years. as shown in table 1, students were divided into four age groups: 6-7, 8-9, 10-11 and 12-13 years. mean age of the female students was 9.2 years and that of male was 8.9 years. a significant correlation was observed between age and salivary flow rate (r=0.395; p < 0.001), higher salivary secretion produced with increased age; table 1and figure 1. the age of children showed a significant positive linear correlation with salivary amylase level, as shown in table 2. overall, the unstimulated salivary flow rate for the primary school children ranged from 0.02 ml/min for the lowest and 1.1 ml/min for the highest rate. flow rate for female students ranged from 0.02 -1.1 ml/min and for male from 0.15 to 0.09 ml/min, with male students produced higher mean salivary flow rate than female (0.341 vs. 0.320 ml/min), however the difference was nonsignificant. as shown in table 1, under unstimulated conditions, the mean salivary amylase is lowest in the youngest age group (6-7) years with a mean of 270.6 u/l, and increased with advancing age to reach a maximum of 309.7 u/l for the oldest age group (12-13 years). the difference observed in salivary amylase between age group was highly significant (p < 0.001). to assess the net and independent association of a set of explanatory variables on salivary amylase concentration as the dependent variable, a multiple linear regression model was used. the explanatory variables include: plaque index, gingival index, salivary flow rate, decayed deciduous teeth surfaces, decayed permanent teeth surfaces, age and gender. table 1: age and oral health status parameters in relation to salivary alpha-amylase indices description salivary amylase (u/l) range mean se n p plaque index good (0.1 -1) (287.9 – 334.9) 305.8 14.7 3 0.72 f=0.336 fair (1.1-2) (187.2 – 373.0) 287.2 4.1 63 poor (2.1-3) (133.5 – 371.5) 287.5 6.6 48 gingival index mild (0.1 -1) (150.1 – 373.0) 281.9 6.5 40 0.22 f=1.508 moderate (1.1-2) (133.5 – 371.5) 291.1 4.3 74 age group (years) 6-7 (133.5 – 358.7) 270.6 7.6 29 <0.001 f=5.933 8-9 (150.1 – 373.0) 281.2 6.1 35 10-11 (212.5 – 371.5) 300.6 5.8 34 12-13 (272.3 – 367.1) 309.7 7.1 16 salivary flow rate categories first (lowest) tertile (<= 1.00) (150.1 – 367.1) 281.0 5.1 56 0.14 f=1.982 second (average) tertile (1.01 – 2.00) (133.5 – 373.0) 297.3 8.5 28 third (highest) tertile (2.01+) (240.2 – 371.5) 293.0 5.7 30 dmft first (lowest) tertile (<= 2) (235.7 – 371.5) 298.3 4.6 43 0.03 f=3.551 second (average) tertile (3 – 7) (187.2 – 373.0) 286.6 6.2 37 third (highest) tertile (8+) (133.5 – 358.7) 275.5 7.7 34 dmft first (lowest) tertile (0) (133.5 – 373.0) 281.4 4.6 66 0.07 f=2.699 second (average) tertile (1) (227.5 – 345.3) 286.8 9.4 11 third (highest) tertile (2+) (150.1 – 367.1) 299.3 6.4 37 as shown in table 3, among the tested explanatory variables, only the age showed a statistically significant positive association with salivary amylase level after controlling for the remaining explanatory variables included in the model. for each one year increase in age, the salivary amylase concentration is expected to increase by an average of 5.2 units. j bagh college dentistry vol. 28(2), june 2016 a salivary α-amylase oral diagnosis 43 table 2: linear correlation coefficient test variables salivary amylase salivary flow rate r=0.193 p=0.044 plaque index r=0.078 p=0.41 gingival index r=0.194 p=0.04 decay primary teeth (dt) r=-0.184 p=0.05 missing primary teeth (mt) r=-0.026 p=0.78 filling primary teeth (ft) r=-0.005 p=0.96 dmft r=-0.186 p=0.047 decay permanent teeth (dt) r=0.300 p=0.001 missing permanent teeth (mt) r=0.186 p=0.048 filling permanent teeth (ft) r=0.114 p=0.23 dmft r=0.309 p=0.001 age r=0.395 p=0.001 table 3: multiple linear regression model with salivary amylase concentration as the dependent (response) variable and selected independent variables partial regression coefficient p standardized regression coefficient (constant) 224.5 <0.001 age (years) 5.2 0.02 0.27 male gender compared to female -10.6 0.15 -0.14 gingival index 36.5 0.19 0.13 plaque index -10.0 0.35 -0.09 decayed primary teeth (dt) -0.48 0.38 -0.09 dt 1.9 0.41 0.09 salivary flow rate 0.27 0.94 0.01 r2=0.21, p (model) =0.005 gender and salivary amylase level considering gender, figure 2 shows that male students showed lower mean salivary amylase level compared to female students, however the difference was not significant. multiple linear regression analysis showed that being a male is expected to reduce salivary amylase by a mean of 10.6 u/l compared to female after adjusting (controlling) for the possible confounder effect of the remaining explanatory variable included in the model. the effect of gender, however failed to reach the level of statistical significance. figure 1: age group in relation to mean salivary amylase concentration. figure 2: gender and mean salivary amylase level j bagh college dentistry vol. 28(2), june 2016 a salivary α-amylase oral diagnosis 44 plaque index (pi) and salivary amylase level as shown in table 1, plaque index scores were categorized into good, fair and poor scores. the majority of the students (55%) were found with fair (moderate) scores, followed with severe (42%), and only 3% of were with mild scores of pi. although, mean salivary amylase level was higher in children with mild pi scores, it showed no statistically significant differences between different categories. in relation to gender both male and female showed the same mean plaque index score (1.943±0.380). gingival index and salivary amylase level gingival index was categorized into mild and moderate score, with the majority of study groups were within the moderate scores 64% (73/114) as shown in figure 3. there was a significant positive linear correlation between gingival index and salivary amylase concentration (p= 0.04). children with moderate gingivitis observed with higher mean of salivary amylase levels (291.1 u/l) compared to those with mild gingivitis (281.9 u/l), however the mean differences were unable to reach the level of statistical significance. caries experience and salivary amylase level decayed-missing-filled-tooth for primary and permanent teeth index scores were divided into three groups, the lowest, average and the highest tertile as seen table 1. dmft showed a statistically significant weak positive linear correlation with salivary amylase level (r=0.309, p<0.001). the mean salivary amylase was smallest among students with 1st lowest tertile dmft scores (281.4 u/l) and increased with increased dmft index scores to reach a maximum of 299.3 u/l among students in the third (highest) tertile dmft group; figure 4. however, the difference observed in the mean salivary amylase between dmft categories failed to reach the level of statistical significance, possibly because of small sample size. considering dt, multiple linear regression analysis showed that for each 1 unite increase in dt, the mean salivary amylase level is expected to increase by amount of 1.9 u/l. this effect however was not significant. regarding dmft index, in this study, results showed statistically significant relation with mean salivary amylase level. figure 4: caries experience (dmft) in relation to salivary αamylase level discussion establishing important data information was an important aim of this study as it is vital for children oral health status management. variables that could influence salivary flow rate were minimized; all children were from the same economic status, none of them were taking any medication or presented with any systemic disease. considering flow rate, there was a significant correlation between age and both salivary flow rate and salivary amylase level. this is consistent with the observation from previous studies that salivary flowrate, protein and enzyme contents in saliva increased with age. salivary flow rate increases with age in children and adolescent populations (2225) although others have reported controversial findings (26, 27). in this study, male students produced higher mean salivary flow rate than female, however the difference was non-significant. this finding agrees with previous clinical study that showed a higher saliva output of males than females even in children populations (22-25). this may be explained on a base of hormonal alterations that have been suggested to influence salivary flow rate (25). multiple linear regression analysis showed that male gender reduce salivary amylase by more than tentimes compared to female after adjusting other confounders, however non-significant. the nonsignificant relation may be due to the small sample size. this is in contrast to the previous study which found a higher level of salivary alpha amylase in male participants (28).the controversial finding may figure 3: gingival score index in relation to mean salivary amylase level j bagh college dentistry vol. 28(2), june 2016 a salivary α-amylase oral diagnosis 45 be due to different age group and socioeconomic status of the study population. regarding age, for each oneyear increase in age, salivary amylase concentration is expected to increase by 5.2 units. this is supported by previous studies that found the level of salivary alpha amylase activity increased along with age (28,29). saliva plays a vital role on caries development through, mechanical cleansing, dilution of substances in the oral cavity, deand -remineralization of dental enamel, pellicle formation, antimicrobial action and buffering of acids produced by biofilm and diets (30, 31). studies addressed the relationship between salivary alpha-amylase and dental caries are few, and the results are in consistent. some research supported the correlation between alpha amylase and dental caries while the others did not. in this study, the relationship between salivary alpha-amylase and dmft scores was assessed, an increase in amylase level was associated with increased dmft index scores to reach the maximum level among primary students in the third (highest) tertile dmft group. multiple linear regression analysis showed that for each oneunite increase in decay tooth (dt), there will be approximately two-fold increase in salivary amylase level. this finding supported by scannapieco et al., study who found that alphaamylase can promote catalyzing the hydrolysis of dietary starch via binding on the surface of cariogenic bacteria (32). consequently, plaque containing amylase-binding bacteria results in concentration of salivary amylase within the plaque matrix providing more glucose in proximity to the tooth surface. finally, this plaque plays a significant cariogenic role in the presence of starchy foods (33). on the other hand, the present study is in consistent with de farias et al. study who did not confirm the relationship between alpha-amylase and dental caries (34). additional research with larger sample sizes is required to confirm these findings. there is sparse literature regarding the relationship between salivary amylase and gingivitis. in the present study, children with higher scores of gingivitis showed the highest levels of salivary amylase. this finding is in accordance with other studies which showed an increased concentration of salivary amylase in patients with gingivitis (35-37). in addition to its digestive action, αamylase exhibits inhibitory activity against various microorganisms (38) and thus may contribute in the oral defence mechanism (39). thus, salivary amylase may be regarded as an important biochemical parameter of inflammation of the periodontium. the higher levels of amylase may be due to the response of salivary glands to inflammatory diseases like gingivitis leading to increase synthesis and secretion of certain acinar proteins (α-amylase) to enhance the oral defense mechanism (39, 40). this may indicate the important of salivary amylase as a defence molecule for the innate immunity in the oral cavity. moreover, it has been suggested that the increased levels of amylase may be due to plasma proteins leakage into saliva due to inflammation (41). as conclusion; 1. the results of the present study emphasize the importance of salivary amylase, as a noninvasive biomarker in regulating oral and dental health. 2. future research with larger samples is required to support these findings. 3. the inconsistency between the results 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and parotid saliva in healthy and periodontitis subjects: determination of cystatins, albumin, amylase and iga. j periodontal res 1996; 31(1): 57-65. 41. henskens ym, van der velden u, veerman ec, nieuw amerongen av. protein, albumin and cystatin concentrations in saliva of healthy subjects and of patients with gingivitis or periodontitis. j periodontal res 1993; 28(1): 43-8. 42. mojarad f, fazlollahifar s, poorolajal j and hajilooi m effect of alpha amylase on early childhood caries: a matched case-control study. braz dent sci 2013; 16(1): 41-5. batool.doc j bagh college dentistry vol. 27(1), march 2015 salivary level of basic sciences 189 salivary level of rankl and opg in chronic periodontitis batool hassan al-ghurabi, b.sc., m.sc., ph.d. (1) sara mohammed mohssen, b.sc., m.sc. (2) abstract background: periodontal diseases are initiated by microbial plaque, which accumulates in the sulcular region and induces an inflammatory response. the receptor activator of nuclear factor-kappa b ligand / osteoprotegerin (rankl/opg) axis is involved in the regulation of bone metabolism in periodontitis, in which an increase in receptor activator of nuclear factor-kappa b ligand or a decrease in osteoprotegerin can tip the balance in favor of osteoclastogenesis and the resorption of alveolar bone that is the hallmark of periodontitis. this study was performed to investigate the role of salivary levels of rankl and opg in pathogenesis of chronic periodontitis. subjects and methods: fifty five subjects with chronic periodontitis with ages range from 24-64 years and 25 apparently healthy volunteers their ages and sexes were matched with the patients were participated in this study. periodontal parameters used in this study were plaque index, gingival index, probing pocket depth, clinical attachment level and bleeding on probing. saliva samples were collected from all patients and controls. enzymelinked immunosorbent assay was carried out for estimation the salivary level of rankl and opg in studied groups. results: the present data revealed that the median salivary levels of rankl was elevated in patient as compared with control group (p<0.001), whereas the salivary levels of opg doesn’t show any significant differences between the study groups (p>0.05). in contrast the ratio of rankl/opg ratio was significantly higher in patients when compared with the ratio in control group. furthermore, negative significant correlation was noticed between rankl and opg. regarding correlation between salivary (rankl and opg) and clinical periodontal parameters, rankl levels was showed significant positive correlation with each of probing pocket depth and clinical attachment level. otherwise no association between opg levels and clinical parameters of periodontitis was found. moreover; the ratio rankl/opg was showed significant positive correlation with each of gingival index, probing pocket depth and clinical attachment level. conclusion: this study demonstrates that salivary levels of rankl and opg play a crucial role in pathogenesis of periodontitis, and the relative rankl/ opg ratio appears to be indicative of disease occurrence. keywords: chronic periodontitis, rankl, opg. (j bagh coll dentistry 2015; 27(1):189-194). introduction periodontitis has a multifactorial etiology, and the characteristic tissue destruction is mediated mainly by the aberrant immune response of the host to periodontopathic bacteria. the role of oral microflora in the etiology of various inflammatory periodontal diseases has been well established, and specificity may vary between bacterial etiologies and different forms of periodontal disease (1,2). the chronic form of periodontitis, termed chronic periodontitis, is the most prevalent disease type (3). while headways have been made in various areas concerning the molecular pathogenesis of periodontitis, one area which of increasing importance is the involvement of the (rankl/opg) axis in bone remodeling and bone loss in periodontitis. rankl and its receptor “receptor activator of nuclear factor-kappa b” (rank) have been recognized as key factors regulating osteoclast formation (4). rankl a membrane-bound or soluble protein belonging to the tumor necrosis factor (tnf) superfamily that is primarily produced in osteobl (1)assistant professor. department of basic sciences, college of dentistry, university of baghdad. (2)department of basic sciences, college of dentistry, university of baghdad. astic lineages and activated t cells. rankl stimulates osteoclast differentiation and activation, and inhibits osteoclast apoptosis. binding of rankl to rank expressed on the surfaces of osteoclasts and their precursors, promotes osteoclast differentiation and activation (5). opg is a soluble tnf receptor–like molecule, is the inhibitor of osteoclast differentiation. it binds to rankl and blocks rankl from interacting with rank and neutralizes its activity by inhibiting the cell-to-cell signaling between osteoblast/bone stromal cells and osteoclast precursor cells, resulting in the inhibition of osteoclast formation. rankl and opg are crucial molecules that act as positive and negative regulators, respectively, in osteoclastogenesis and bone resorption. under normal physiologic conditions, there is a balance between bone resorption and bone formation. upregulation of rankl has been seen in inflamed periodontal tissues, indicating that rankl strongly participates in the processes of periodontal tissue destruction (6). therefore this study was performed to investigate the role of salivary levels of rankl and opg in pathogenesis of chronic periodontitis. j bagh college dentistry vol. 27(1), march 2015 salivary level of basic sciences 190 subjects and methods fifty five patients with chronic periodontitis (38 male and 17 female) were enrolled in this study, their age range from 24 to 64 years. they were from attendants seeking treatment in the department of periodontics, college of dentistry, baghdad university from novmber 2012 to janraury 2013. diagnosis was made by specialized dentists in the college. oral examination was performed at four surfaces of each tooth except 3rd molar according to the following criteria: assessment of dental plaque by (pi) of silness and loe (7). assessment of gingival condition by (gi) (8). probing pocket depth (ppd), clinical attachment level (cal) and bleeding on probing (bop). all the cases had received no treatment with no complain of chronic or systemic diseases. apparently healthy periodontium volunteers their ages and sexes were matched to patients consisted of 25 individuals who were considered as control (19 males and 6 females). the saliva obtained from patients and healthy controls were analyzed for rankl and opg by using commercially available elisa and performed as recommended in leaflet with kits, (human rankl and opg elisa kit/ cusabio/china). statistical analysis it was assessed using p (mann-whitney-test), p (bonferroni-test). correlation between the different parameters was calculated by the spearman test and p values of p<0.01and p<0.05 were considered significant. results in the present study the mean age of patients was 40.15 ± 10.53 years, and there was male’s predominance among patients, about (69.1%) of cp patients were males, while only (30.9%) were females. furthermore, (34.5%) of patients had positive family history of chronic periodontitis, while (65.5%) showed negative family history as clearly shown in table (1). the differences in clinical periodontal parameters in patients and healthy controls are summarized in table (2). table (3) revealed a highly significant elevation in level of rankl among patients (56.8 pg/ml) in comparison to that of healthy control (2.21 pg/ml), (p<0.001). while there is no significant differences (p>0.05) in median level of opg between patients and healthy control groups (15 ng/ml; 17.99 ng/ml) respectively, as shown in table (4). determination the ratio of rankl / opg in current study revealed, that there was high difference between two study groups. the median rankl / opg ratio in chronic periodontitis patients (3.61) was significantly higher (p<0.001) in comparison to the ratio in healthy control (0.12), according to tables (5). the results of correlation between rankl and opg are clearly shown in table (6). an anticipated, salivary rankl level was showed significant negative correlation with opg (r=0.331, p=0.024). on the other hand the current study found that rankl/opg ratio was positively correlated with rankl(r=0.724, p=0.001), whereas negatively correlated opg (r=0.300, p=0.006). regarding the correlation of rankl and opg with clinical periodontal parameters, rankl level was showed significant positive correlation with each of ppd (r=0.387, p=0.004) and cal (r=0.267, p=0.049), as observed in table (7). in contrast, there is no association between opg levels and other clinical parameters of periodontitis was found (p>0.05), table (8). moreover; the current study found that the rankl/opg ratio was positively correlated with each of gi, ppd and cal (r= 0.250, p=0.024; r=0.409, p<0.001; r=0.334, p=0.002) respectively, as shown in table (9). table 1: demographic characteristic in cp patients and healthy control study groups p-value cp patients n=55 healthy control n=25 age and sex age (years) range (24-64) (20-51) mean ± sd 40.15±10.53 37.38±9.10 0.254ns gender type female 17 (30.9%) 6 (24%) 0.128ns male 38 (69.1%) 19 (76%) 0.672ns ns=not significant (p>0.05). ** = highly significant difference (p≤0.001). j bagh college dentistry vol. 27(1), march 2015 salivary level of basic sciences 191 table 2: clinical periodontal parameters in cp patients and healthy control. study groups p-value cp patients n=55 healthy control n=25 clinical periodontal parameters (mean ± sd) plaque index 1.50±0.62 0.85±0.37 <0.001** gingival index 1.26±0.49 0.74±0.29 <0.001** probing pocket depth (mm) 2.10±0.66 1.17±0.62 <0.001** clinical attachment loss 3.08±3.74 0.00±0.00 <0.001** bleeding on probing (bop) 28.85±30.57 6.12±8.08 <0.001** ** = highly significant difference (p≤0.001). table 3: differences in saliva concentration of rankl between patients and healthy controls cp patients (n=55) healthy control (n=25) p (mann-whitney) saliva rankl range (6.21-284.34) (0-10.18) median 56.8 2.21 <0.001** inter-quartile range (15.99-85.4) (1.2-6.27) mean rank 53.15 15.29 table 4: differences in saliva concentration of opg between patients and healthy controls cp patients (n=55) healthy control (n=25) p (mann-whitney) saliva opg range (2.3-57) (4.57-28.3) median 15 17.99 0.070ns inter-quartile range (10.25-19.3) (12.68-20.91) mean rank 37.84 47.69 table 5: differences in ratio of rankl\opg between patients and healthy controls cp patients healthy control p (mann-whitney) (n=55) (n=25) salivary ratio rankl/opg range (0.3-34.24) (0-1.54) median 3.61 0.12 <0.001** inter-quartile range (1.24-9.04) (0.06-0.43) mean rank 52.9 15.83 table 6: correlation between rankl and opg among patients variables rankl opg rankl/opg rankl 1 r=-0.331 p=0.024* r=0.724 p=0.001** opg r=-0.331 p=0.024* 1 r=-0.300 p=0.006* rankl/opg r=0.724 p=0.001** r=-0.300 p=0.006* 1 table 7: correlation between saliva level rankl and clinical periodontal parameters in patients rankl correlation pvalue plaque index 0.119 0.388ns gingival index 0.047 0.733 ns probing pocket depth (mm) 0.387 0.004* clinical attachment loss 0.267 0.049* bleeding on probing (bop) -0.108 0.432 ns j bagh college dentistry vol. 27(1), march 2015 salivary level of basic sciences 192 table 8: correlation between saliva level opg and clinical periodontal parameters in patients opg correlation pvalue plaque index 0.077 0.574 ns gingival index -0.072 0.600 ns probing pocket depth (mm) 0.019 0.892 ns clinical attachment loss 0.015 0.913 ns bleeding on probing (bop) 0.072 0.600 ns table 9: correlation between serum level rankl\opg and clinical periodontal parameters in patients rankl/opg ratio correlation p value plaque index 0.209 0.062ns gingival index 0.250 0.024* probing pocket depth (mm) 0.409 <0.001** clinical attachment loss 0.334 0.002* bleeding on probing (bop) 0.214 0.055 ns discussion inflammation and bone loss are hallmarks of periodontal disease. accumulated evidence demonstrates that periodontitis involves bacterially derived factors and antigens that stimulate a local inflammatory reaction and activation of the innate immune system. proinflammatory molecules and cytokine networks play essential roles in this process. il-1 and tnf-α seem to be primary molecules that, in turn, influence cells in the lesion. antigenstimulated lymphocytes (b and t cells) also seem to be important. eventually, a cascade of events leads to osteoclastogenesis and subsequent bone loss via the rank–rankl–opg axis. this axis and its regulation are not unique to periodontitis but rather are critical for pathologic lesions involving chronic inflammation (5). the current results denoted a predominance of cp among males than a female which is comparable with other iraqi study conducted by fadil and alghurabi in 2012 (9), whereas, disagree with the result reported by ali and colleagues (10) who observed that periodontitis in males less than as in females. the large prevalence of periodontitis among males may be due to that male less interest in oral hygiene than males. positive family history was observed in 34.4% of patients with cp. this high rate of a positive family history in the present study raises the possibility of a genetic basis for cp transmission. however; this percentage which is in agreement with a local study reported by ali et al., (10) who found 32% of patient had positive family history, and disagree with broad studies (11, 12). the findings of the present study indicate that the rankl levels in saliva of chronic periodontitis patients were increased compared to controls, whereas the opg levels were unchanged. these results are in agreement with other studies (13, 14, 15), who found an increase in soluble rankl concentrations without a corresponding change in opg levels in individuals with chronic periodontitis compared to healthy controls. conversely, a reciprocal relationship was also found, in which rankl protein expression was higher and opg levels were lower in diseased gingival tissues compared to healthy controls (16). in consistent with our results wara and colleagues, pointed out to that although the exact levels of rankl and opg varied from study to study, the trend was generally the same; the rankl/opg ratio was higher in periodontitis patients than in healthy controls (15). these findings correspond well with the critical role of rankl in driving osteoclastogenesis and bone loss in periodontitis (17). similarly, corrti and colleagues showed that study on rankl versus opg concentrations in gingival tissue extracts clearly demonstrated a trend toward a higher rankl/opg ratio in individuals with periodontitis than in healthy controls. in a cross-sectional study, bostanci et al. (18) quantified the rankl and opg levels in gcf from 21 healthy subjects, 22 gingivitis, 28 cp, 25 generalized aggressive periodontitis and 11 chronic periodontitis immunosuppressed patients, detecting that rankl levels increased and opg decreased in periodontitis patients compared with either gingivitis or healthy individuals, and concluded that rankl/opg ratio may predict disease occurrence. j bagh college dentistry vol. 27(1), march 2015 salivary level of basic sciences 193 the higher rankl/ opg ratio could explain in part the amount of bone loss in periodontitis patients, and this either be related to lower levels of opg or higher levels of rankl in periodontitis patients compared with healthy control. however, an increased rankl/opg ratio also may be associated with the clinical severity of periodontitis. the current study found that the rankl/opg ratio was positively correlated with each of gi, ppd and cal, this result was consistent with that reported by fatemeh et al., (19) in which there was statistically significant correlation between the concentration of rankl and cal in chronic periodontitis patients, there was also negative correlation between opg concentration and cal in those patients. meanwhile, bostanci et al., stated that although periodontitis is associated with an increased rankl/opg ratio compared to healthy controls, the ratio may not necessarily distinguish between mild, moderate, and severe forms. nevertheless, results show that rankl contributes to alveolar bone loss in periodontitis and tooth loss, other findings have suggested that the increased rankl/opg ratio may serve as a biomarker that denotes the occurrence of periodontitis, but may not necessarily predict ongoing disease activity (14). microbial stimulation with aggrigatibacter in chronic periodontitis induced rankl expression on the surface of cd4 + cells and this may explain the elevation of rankl/opg ratio in periodontitis (20). in conclusion this study demonstrates that salivary levels of rankl and opg play a crucial role in pathogenesis of periodontitis, and the relative rankl/ opg ratio appears to be indicative of disease occurrence. references 1. craig rg, yip jk, mijares dq, legeros rz. j clin periodontol 2003; 30: 1075-83. 2. carenza a. clinical periodontology. 10th ed. philadelphia: wb saunders company; 2009. 3. cazalis j, tanabe s, gagnon g, sorsa t, grenier d. tetracyclines and chemically modified tetracycline-3 (cmt-3) modulate cytokine secretion by lipopolysaccharide-stimulated whole blood. inflammation 2009; 32: 130-7. 4. garlet gp, cardoso cr, sliva ta, et al. cytokine pattern determines the progression of experimental periodontal disease induced by actinobacillus actinomycetemcomitans through the modulation of mmps, rankl, and their physiological inhibitors, oral microbiol immunol 2006; 21: 12-20. 5. cochran dl. inflammation and bone loss in periodontal disease. j periodontol 2008; 79: 1569–76. 6. kirkwood kl, cirelli ja, rogers ej, giannobile wv. novel host response therapeutic approaches to treat periodontal diseases. periodontol 2000 2007; 43: 294315. 7. silness j, löe h. periodontal disease in pregnancy ιι. acta odontol scand 1964; 24: 747-59. 8. löe h. the gingival index, the plaque index and the retention index system. j periodontol 1976; 38: 6106. 9. fadil z, al-ghurabi b. study the role of pro-and antiinflammatory cytokines in iraqi chronic periodontitis patients. j bagh coll dentistry 2012; 24(1): 164-69. 10. ali ao, saleem ss, algobory sh. reliability of family history report among relatives of aggressive periodontitis patients. j bagh coll dentistry 2008; 20(1): 152-160. 11. hart tc, marazita ml, mccanna km, schenkein ha, diehl sr. reevaluation of the chromosome 4q andidate region for early onset periodontitis. human genetics 1993; 91: 416–22. 12. llorente ma, griffiths gs. periodontal status among relatives of aggressive periodontitis patients and reliability of family history report. j clin periodontol 2006; 33: 121–5. 13. kawai t, akira, s. pathogen recognition with tolllike receptors. curr opin immunol 2005; 17: 338–44 14. lu hk, chen yl, chang hc, li cl, kuo my. identification of the osteoprotegerin/receptor activator of nuclear factor-kappa b ligand system in gingival crevicular fluid and tissue of patients with chronic periodontitis. j periodontal res 2006; 41: 35460. 15. wara-aswapati n, surarit r, chayasadom, boch ja, pitiphat w. rankl upregulation associated with periodontitis and porphyromonas gingivalis. j periodontol 2007; 78: 1062-1069. 16. crotti t, smith md, hirsch r, et al. receptor activator nf kappab ligand (rankl) and osteoprotegerin (opg) protein expression in periodontitis. j periodontal res 2003; 38: 380-87. 17. taubman ma, valverde p, han x, kawai t. immune response: the key to bone resorption in periodontal disease. j periodontol 2005; 76: 203341. 18. bostanci n, ilgenli t, emingil g, afacan b, han b, toz h, atilla g, hughes fj, belibasakis gn. gingival crevicular fluid levels of rankl and opg in periodontal diseases: implications of their relative ratio. j clin periodontol 2007; 34: 370-76. 19. fatemeh s, mandana s, shilan r, malihe n. receptor activator of nuclear factor kappa b ligand and osteoprotegerin levels in gingival crevicular fluid. dent res j 2012; 9(6): 752-7. 20. teng yt, nguyen h, gao x, kong yy, gorczynski rm, singh b, ellen rp, penninger jm. functional human t-cell immunity and osteoprotegerin ligand control alveolar bone destruction in periodontal infection. j clin invest 2000; 106: 59-67. j bagh college dentistry vol. 27(1), march 2015 salivary level of basic sciences 194 الخالصة یساھم في opgو rankl ان محور. تنشا امراض ما حول اللثة عن طریق الصحیفة الجرثومیة التي تتراكم في منطقة التلمیة والتي تحث االستجابة االلتھابیة :الخلفیة العلمیة و التي ھي لتي فیھا الزیادة في الرانكل والنقصان في االوبجي یمكن ان یرجح التوازن باتجاه عملیة نقض العظم وارتشاف العظم النسغيعملیة تنظیم ایض العظم في مرض النساغ وا .المزمنةفي التسبب في اللثة opgو ranklتم إجراء ھذه الدراسة لبحث دور مستویات اللعابیة من .السمة الممیزة لمرض النساغ طابقة مع تم اعمارھم و اجناسھم صحاء كانتاالتطوعین ن المم 25عاما و 64-24 بین أعمارھمبمرض النساغ المزمن تتراوح مریضا مصاباخمسون خمسة و: العمل وطرق المرضى فقدان و اللثة و بوجیعمق التھابات اللثة ومؤشر الصحیفة الجرثومیة ومؤشر ھي المستخدمة في ھذه الدراسةما حول االسنان معلمات وكانت . في ھذه الدراسة شاركوا المرضى المستوى اللعابي من لتقدیر المرتبط الممتز المناعیة فحص مقایسة االنظیم وأجري. السیطرةوالمرضى مجموعتيتم جمع عینات من اللعاب من . اثناء الفحصنزیف الواالنسجة الرابطة rankl وopg مجموعتي الدراسة في. مستویات اللعابیة ال، في حین أن )p >0.001(مقارنة مع مجموعة التحكم ىضارتفع في مجموعة المرقد ranklمستویات اللعابیة من ال متوسط كشفت البیانات الحالیة أن: النتائج أعلى بكثیر لدى المرضى بالمقارنة مع النسبة في rankl / opgفي المقابل كانت نسبة ) . p <0.05(تظھر أي فروق ذات داللة إحصائیة بین مجموعات الدراسة لم opgمن ومعلمات اللثة ) opgو rankl(من اللعابیة المستویات رتباط بینباالوفیما یتعلق . opgو ranklوعالوة على ذلك، لوحظ ارتباط كبیر سلبي بین . ضابطةالمجموعة ال والمعلمات السریریة opgمستویات بین یالحظ وجود عالقةلم و. فقدان االنسجة الرابطةب ووارتباط إیجابي كبیر مع كل من عمق الجی ranklالسریریة، وقد أظھر مستویات .وفقدان االنسجة الرابطةب وعمق الجی التھاب اللثة،ارتباط إیجابي كبیر مع كل من مؤشر rankl / opgقد أظھرت نسبة وعالوة على ذلك، . اللتھاب اللثة تكون مؤشرا على قد rankl / opgنسبة ان اللثة، و امراض تسبب فيتلعب دورا حاسما في ال opgو ranklتوضح ھذه الدراسة أن مستویات اللعابیة من : االستنتاجات .حدوث المرض rankl ،opgالتھاب اللثة المزمن، : مفتاحیةكلمات ال mustafa f.doc j bagh college dentistry vol. 25(2), june 2013 the effect of different restorative dentistry 24 the effect of different finishing and polishing systems on surface roughness of new low polymerized composite materials (an in vitro study) mustafa r. abdurazaq, b.d.s. (1) ali h. al-khafaji, b.d.s., m.sc.d. (2) abstract background: adequate finishing and polishing of resin composites is a prerequisite for high-quality esthetics and enhanced longevity of resin-based restorations. finishing and polishing of resin composites are important procedures in restorative dentistry. finishing refers to gross contouring of a restoration to obtain the desired contour. however, polishing refers to smoothness as well as to reduction of the scratches created by the finishing instruments. materials and methods: four types of composite materials where used in this study, filtekp90 (3m espe, st.paul, u.s.a), tetric evoceram (vivadent, schaan, liechtenstein), filtekz250 (3m espe, st.paul, u.s.a), filtekp60 (3m espe, st.paul, u.s.a), also two polishing systems which are: optrapol (ivoclar vivadent) and enhance (dentsply) and one silicone carbide finishing paper. a total number of 160 disc shaped specimens were produced in a circular steel molds with a circular hole in its center , with a diameter of (10×3mm), specimens where divided into four groups of 40 specimens each (10 samples from each composite type) according to the finishing/ polishing protocol used as follows group a: control without finishing and polishing. group b: polishing using optrapol polishing system. group c: polishing with enhance polishing system. group d: finishing only with silicone carbide finishing paper(600 grit). except for the control group specimens first are finished using silicone carbide paper 600 grit for obtaining a baseline surface roughness before the application of polishing systems, the at the completion of the finishing and polishing instrumentation, the specimens were ultrasonically cleaned in an ultrasonic unit with distilled water for two minute. the surface roughness was measured by using a portable surface roughness tester (srt 6210). results: the result showed that all the composite materials under control group that cured using mylar strip exhibited the least surface roughness values (best smoothness). all the composite materials produced smoother surface when polished with optrapol system than with enhance system. for the silicone carbide finishing paper we found that all the materials produced high surface roughness values than with other finishing and polishing systems and there was no significant difference between the composite materials. conclusion: filtekp90 exhibited the smoothest surface finish compared to the other composite materials used in this study while filtekp60 exhibited the roughest surface finish compared to the other composite materials used in this study. key words: finishing and/or polishing of composite, surface roughness, roughness tester, diamond polishers. (j bagh coll dentistry 2013; 25(2):24-30). introduction finishing and polishing of resin composites are important procedures in restorative dentistry. finishing refers to gross contouring of a restoration to obtain the desired contour. however, polishing refers to smoothness as well as to reduction of the scratches created by the finishing instruments (1). survival of bacteria in the oral cavity is dependent upon adhesion to hard surfaces, such as those of teeth, filling materials, dental implants, or prostheses (2). it is widely accepted that the surface roughness of intraoral hard surfaces has a major impact on the initial adhesion and the retention of oral microorganisms: in detail rougher surfaces (crowns, implant abutments, and denture bases) retain more plaque than smoother ones (3). (1) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. roughness has also a major impact on the aesthetic appearance and discoloration of restorations (4), secondary caries, gingival irritation and wear of opposing and adjacent teeth (5). in patients with less than adequate oral hygiene, variations in surface roughness of provisional restorations may be associated with onset of subclinical or even clinical inflammation (6). on the other hand, a smoother surface of intraoral structures ensures patient comfort and facilitates oral hygiene (5). adequate finishing and polishing of resin composites is a prerequisite for high-quality esthetics and enhanced longevity of resin-based restorations. a survey of published studies indicated that smooth, highly polished restorations present a host of advantages ranging from esthetics to survival: more esthetically appealing and easier to maintain than restorations with a more roughened surface (7), less susceptible to plaque accumulation and extrinsic discoloration and restorative dentistry 25 improved mechanical propertie (8). for resin composite restorations polymerized under a matrix strip, they tend to exhibit the smoothest surface; none the less, the marginal areas would still require finishing and polishing. on the latter procedure, several investigations have shown that removal of the polymer-rich, outermost resin layer is essential to achieving a stain-resistant, more esthetically stable surface (9). on the other hand, park et al, (10) found no differences in surface discoloration between celluloid strip-finished and the polished surfaces of microhybrid composites. finishing and polishing requires sequential use of at least two—but generally more—instruments with gradually smaller abrasive particles. apart from polyurethane-based finishing and polishing disks, fine diamond burs, rubberized resinor siliconimpregnated abrasives, and polishing pastes are the most frequently used abrasives to obtain the desired glossy and smooth surface (11).the final polishing result depends on the filler size, shape, and loading in the resin composite. the larger the filler particles, the rougher the surface would be after polishing (12). materials and methods a total number of 160 disc shaped specimens were produced in circular steel molds with a circular hole in its center, with a diameter of (10×3mm).the composite resin was loaded by injecting it directly from the tube in to the hole in order to reduce air voids. the material was condensed into the mold by ash no.6 until it become intentionally overfilled. the surface of the material was covered with a matrix strip and covered with a glass slide. the molds were bulk-filled to slight excess, in order to produce a flat smooth surface and to prevent the formation of oxygen-inhibited layer on the surface of the samples (13). a (200 gm) pressure has been applied for 1min. to expel excess material from the mold and to reduce void (14), each specimen was thoroughly light-cured through the application of the emitting tip of light curing unit directly on the top of the glass slide at a distance of about 1.2mm, which is the thickness of the glass slide and celluloid strip. the resin composites were exposed by using an astralis light-curing unit (ivoclar vivadent, ag, schaan, liechtenstein) at 560 mw/cm2 for 40 seconds. the polymerization of the disk was carried out on the top and bottom sides against the strip and glass plate and then for another similar amount of exposure but without the glass plates (13). the hardened specimens were then removed from the mold and lightly finished manually at the periphery carefully using a steel cutter after 24 hours from the preparation (13). finishing/polishing protocols and group organization the composite specimens where divided into four groups of 40 specimens each (10 samples from each composite type) according to the finishing/ polishing protocol used as follows: group a: control without finishing and/or polishing. in this group the samples where prepared and cured under transparent matrix strip only then stored for one week in ionized distilled water before surface roughness measurement. group b finishing using optrapol polishing system (ivoclarvivadent) (figure 1). this system consist of diamond impregnated polishers (cups, discs and flames) , the polishing procedure should be performed wet under running water from a disposable syringe intermittently for 20 seconds to avoid heat generation . the polishing is done using the polishing discs attached to a straight hand –piece at a speed of 10000 rpm, according to the manufacturer instructions. figure 1: optrapol polishing system. the hand-piece was attached to a surveyor for standardization and the sample was placed inside an acrylic mold for stabilization which is attached to an electronic balance plate by using super glue for standardization of pressure applied by the hand-piece on the sample, the polishing disk was brought into touch with the sample till it records a pressure range of (190-210) gm ,and the polishing was done under water spray from air triple syringe of dental unit, the polishing was made for 5 seconds with two second rest, then repeating the procedure to obtain a total of 20 seconds polishing time. the specimens were restorative dentistry 26 thoroughly cleaned with distal water for 5 seconds then placed in an ultrasonic cleaner for two minutes removing detritus formed by polishing before measurement. (13). group c: polishing with enhance polishing system (dentsply) (figure 2). this system is a three steps polishing system which involves a finishing foam wheel impregnated udma (urethane dimethacrylate) with two polishing paste systems (aluminum oxide—silicone dioxide finishing wheel-impregnated udma (40 μm), prisma gloss polishing paste (fine and xfine)). according to the manufacturer instruction no water spray was used, and every one of the three steps should be done intermittently for 20 second. the first step is polishing with the disc only without using of polishing paste, the next polishing step involved the placement of polishing paste of prisma gloss (fine) on the surface of the sample and proceeding with the same polishing time as mentioned above. figure 2: enhance polishing system the third step involved the placement of xfine polishing paste according to the manufacturer instructions. we used glass ionomer cement spoon with one spoon volume for each application for standardization of paste volume. after each step the sample was thoroughly rinsed with distilled water for 5 seconds and dried with air for 5 seconds before proceeding to the next polishing step (13). surface roughness of specimens ground on 600-grit sic paper, specimens surfaces were manually ground for 10 seconds on wet 600-grit sic paper under slight pressure with range of (190-210 gm) and in varying directions. after rinsing for 5 seconds and air-drying for 5 seconds using air jet. the samples are ready for surface roughness measurement (15). group d: finishing with silicone carbide finishing paper the silicone paper is attached to an electronic balance to standardize pressure on the specimen. the pressure range was between 190 -210 gram. storage of the specimens each ten samples of each group were stored in a dark plastic container containing distilled water at room temperature for one week. the samples were covered by the water before starting the surface roughness measurement procedures (13). experimental surface roughness measurement procedures at the completion of the finishing and polishing instrumentation, the specimens were ultrasonically cleaned in an ultrasonic unit with distilled water for two minutes. the surface roughness was measured by using a portable surface roughness tester (srt 6210) figure 3. the stylus traversed the surface of the specimen at a constant speed of 0.5 mm/second with a force of 4 mn and automatic return. each specimen was traced in four line locations across the center of the finished and/or polished surface with an evaluation length of 4 mm. all preparation of specimens and finishing/polishing procedures were performed by only one operator to minimize the bias. a calibration block was used periodically to check the performance of the profilometer. figure 3: portable surface roughness tester. restorative dentistry 27 the surface roughness parameter values were monitored on a computer. the overall roughness of the surface, which is called roughness avarage (ra), was measured. it is defined as the arithmetical average height surface component irregularities (the absolute distance of the roughness profile) from the mean line within the measuring length and the a critical roughness value is 0.2 μm (13). results the descriptive statistics which represent the mean, standard deviation (±sd) with the maximum (max) and minimum (min) values of the surface roughness of unpolished and polished samples (ra) in micrometer (μm) are shown in table 1. the comparison between the four groups of control and polishing systems in surface roughness measurement. one-way anova test showed that there was a highly significant difference among all groups of control and finishing and/or polishing systems (p< 0.01). by performing the least significant difference (lsd) test, was performed for all the subgroups and the result showed that there was high significant difference of the control group and both the polishing systems groups and there was no significant difference among subgroups of the silicone carbide finishing group. table 1: the descriptive statistics (means, standard deviations (sd) of roughness values in μm for all groups subgroups n mean ±sd a1 10 .2098 .06617 a2 10 .2792 .06137 a3 10 .2718 .07312 a4 10 .3291 .11558 b1 10 .2726 .06292 b2 10 .3549 .09261 b3 10 .3968 .08243 b4 10 .4792 .09176 c1 10 .5910 .05109 c2 10 .6374 .06308 c3 10 .7349 .07000 c4 10 .7538 .05271 d1 10 .8686 .12933 d2 10 .8315 .10188 d3 10 .8323 .07222 d4 10 .8328 .08668 figure 4: bar chart showing mean values of surface roughness ra of all subgroups. discussion finishing and polishing of resin composite finishing and polishing of resin composite restorations are steps critical to enhance the esthetics and longevity of restored teeth (16). as for the surface quality of resin composite restorations, it has been established that it is closely related to both the polishing procedure and inherent material characteristics such as size, hardness, amount of filler particles, and structure of the resin matrix (17). the four types of composites used in this study: filtek p90; filtek p60; filtek z250 and tetric evoceram, were selected because they have different filler and resin matrix compositions as well as superior properties, as claimed by manufacturers, to be used as low-shrinking posterior restoratives. they mainly differ in their inorganic component, the type of inorganic filler, the size of the particles and the extent of the filler loading vary widely among these materials in addition to difference in the resin matrix. these factors influence their polish-ability (18, 19). two different types of polishing systems were used in this study; optrapol polishing system and enhance polishing system. they were selected because they differ in their abrasives; the first one has an aluminum oxide-silicone oxide abrasives, and the second one has diamond abrasives, so as to compare between the two components. purified distilled water was used as a storage medium because it simulates the wet oral environment provided by saliva and water. saliva is a diluted fluid comprising of 99% water and the concentration of dissolved solids (organic and inorganic) are characterized by wide variations, both between individuals and within a restorative dentistry 28 single individual. due to these variations, water was used as the storage medium (20) one week water aging was performed in the present study, because the dimensional changes in composite resins were the result of the shrinkage of the resin monomer during polymerization in the first week. in the present study, pretreatment of resin composite surfaces was either as cured under a mylar strip or “finished” with wet, 600-grit sic paper. finishing cured specimens with sic paper of 600-grit (average particle size: 30 μm) was a reasonable procedure, since dental finishing instruments are often loaded with abrasive particles of this size or a similar grain size. further, grinding on wet sic paper bore the additional advantage of a finishing process that was easier to standardize than with rotating instruments (15). surface roughness of the control group (without finishing and polishing) according to the study in comparison between the four main groups we found that all the composite materials under control group that cured using mylar strip exhibited the least surface roughness values (best smoothness). the surface roughness of polished composites was higher than unpolished controls, suggesting that polishing determines by itself as a surface damage factor. this may be due to the surface finish that was obtained by the mylar strip is a resin –polymer rich layer containing less fillers giving more smooth surface. this finding is in agreement with (13,15, 21, 22). on the other hand this finding is in disagreement with (23).this could be due to the difference in the type of method and polishing system used in the study. surface roughness of finishing and polishing groups of composite for the polishing systems there was a high significant difference between them for all the materials used, various surface defects can appear in materials, such as micro-cracks and irregularities, because of the removal of some of the surface particles during polishing, increasing the surface roughness of the restoration, composite surface roughness is basically dictated by the size, hardness, and amount of filler which influences the mechanical properties of the resin composites (19). all the composite materials produced smoother surface when polished with optrapol system than with enhance system. this system has diamond abrasives whereas enhance utilizes aluminum oxidesilicone dioxide as abrasive particles. diamond is always harder than alumina so it cuts evenly both the matrix and the filler parts of the composite giving less irregularities and more smooth surface, thereby, in this study, optrapol produces the smoothest surface on most of the materials . this could be attributed to the fact that diamond discs are less flexible as compared to the extremely flexible aluminum oxide discs. another reason for the diamond discs giving better surface smoothness in the study over aluminum oxide-silicone dioxide could be due to the non displacement of part of the composite fillers particles by enhance. the diamond discs performed better because the fillers in composite are so their malleability promotes a homogeneous abrasion of the fillers and the resin matrix (24).study by mitra et al (25) also supported the concept of homogeneous abrasion. this finding is in disagreement with others because of different methods and materials used. (26) surface roughness after finishing with silicone carbide finishing paper for the silicone carbide finishing paper we found that all the materials produced high surface roughness values than with other finishing and polishing systems and there was no significant difference between the composite materials. this may be due to the size of the abrasives (average particle size: 30 μm), so it cut the composite surface unevenly producing high irregularities and roughness, this finding is in agreement with (15). differences in surface roughness values of the different composite materials according to this study, for the composite filling materials there was a high significant difference in (ra) values this may be attributed to the differences in composition among the materials. the occurrence of in vitro surface abrasion (wear and wear resistance) of resin based composites has been identified to be influenced by the filler size, morphology and distribution (27).following the loss of the resin matrix at the surface of resin based composite restorations, protruding filler particles remain. subsequently, the rate of wear was initially slow as the protruding filler acts as a ‘protective shoulder’ to the remaining resin matrix, whilst continued loss of the resin causes filler ‘plucking’ and surface void formation (28).the presence of larger fillers, such as those in traditional rbcs exhibit stressinduced ‘tilting’ and subsequent removal of protruding particles, resulting in increased surface roughness due to large pores and defects. according to the findings of this study, for all the four main groups, filtek p90 yielded the lowest ra values among all composite materials restorative dentistry 29 except d1 after the finishing/polishing procedures. the lower surface roughness of these materials may be attributed to its composition. among the materials investigated, this composites comprises low filler content by weight (76–77%), also it is characterized by a special resin matrix made up of silorane, which is polymerized cationically by a ring-opening expansion mechanism (29).this expanded network is based on oxirane and siloxane backbones. siloxane exhibits a more stable chemical structure, as it is conjugated with a silicone atom furthermore, it has a relatively smaller filler particle size (0.47 μm) that may also contribute to the low surface roughness value (29). the posterior packable hybrid composite (filtek p60), expressed the highest surface roughness among the materials examined. this material exhibited an average particle size of 0.6 μm with a range of 1 to 3.5 μm and a filler loading of 83% wt. it has been noted that the largest particles present in the composites contribute more to the surface roughness than do the average particle size (12).additionally, it comprises udma and high molecular weight bis-ema (ethoxylated bisphenol a glycol dimethacrylate) that form fewer double bonds resulting in a slightly softer matrix (12). another possible explanation could be related to the deficiency of coherence between the matrix and the fillers yielded from nonsilanization of the latter. this may cause exfoliation of some filler particles as the weak resin matrix is worn away during finishing and polishing procedures. dislodgment of larger filler particles is usually associated with preferential loss of the resin, which is unable to adequately stabilize these particles, causing detectable surface irregularities thereby increasing the ra value (13).this was in agreement with others (30). the filtek z250 and tetri evoceram have intermediate roughness values: for tetricevoceram which is a nano-hybrid rbcs, showed lower post-polishing (ra) mean value than filtekp60. this may be attributed to that, it contain a mixture of colloidal silica particles with a size distribution of 0.01-0.07μm in addition to micron-sized filler particles of 0.1-2.5μm, such as borosilicate, admixed with a methacrylatebased resin matrix (31).the inclusion of smaller filler particles as nano-size in the final formulation of the composites results in reduction of composite’s shrinkage and improving their total mechanical properties (32).additionally, materials reinforced with nano-sized filler particles and agglomerations exhibit distinct properties compared with conventional filler types (33). the filtek z250 which is microhybrid has almost the same composition of the filtek p60 but it differs in that it has a silinated filler with less filler loading this lead to less (ra) mean value than p60 . references 1. lutz f, setcos jc, phillips rw. new finishing instruments for composite resins. j am dent assoc 1983;107: 575–80 2. sen d, göller g, isever h. the effect of two polishing pastes on the surface roughness of bis-acryl composite and methacrylatebased resins. j prosthet dent 2002; 88: 527-32. 3. borchers l, tavassol f, tschernitschek h. surface quality achieved by polishing and by varnishing of temporary crown and fixed partial denture 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the push out bond strength of bioceramic sealer(total fill) after warm and cold obturation techniques an in vitro comparative batool basim mounes 1*, raghad alhashimi2 1 master student, department of conservative dentistry, college of dentistry, university of baghdad. 2 professor, department of conservative dentistry, college of dentistry, university of baghdad. *correspondence: batoolbasim92@gmail.com abstract: background: the goal of a root canal treatment is three dimensional obturation with a complete seal of the root canal system. the aim of this study was to evaluate and compare the effect of two warm obturation techniques, warm vertical compaction (wvc) and, carrier based obturation technique gutta core (gc), versus two cold obturation techniques, cold lateral compaction (clc) and, single cone (sc) on push-out bond strength of bioceramic sealer (total fill) at three different root levels. materials and methods: forty extracted maxillary first molars teeth with a straight round palatal root canal and mature apices were selected for this study. after sectioning the palatal roots to 11 mm from the root apex, the canals were prepared with edgeendo x7 rotary system file from size 20 up to size 40 taper 04. the samples were then randomly separated into four groups based on obturation procedures (each group n = 10), with group a: obturated by wvc, group b: gc, group c: clc, and group d: sc. following obturation, the teeth were kept in an incubator at 37°c and 100% humidity for two weeks. three slices of 2 mm thickness were cut horizontally at 2, 4.5, and 7 mm from the root apex in each of the three sections (apical, middle and coronal). the data were investigated using one-way anova and tukey's test with a significance level (p< 0.05). a digital microscope with a magnification of 60 x was used to establish the failure mode. results: there was a significant increase in push-out bond strength following canal obturation with gc and wvc, particularly at the apical third (9.48, and 8.11 mpa, respectively) , compared to canals obturated with sc and clc in all root levels except the middle third, at the (p< 0.05) significance level. the cohesive mode of failure was the most prevalent in all groups. conclusio: bc (totalfill) sealer showed higher bond strength when used in wvc and gc compared to other techniques. sc and clc were showed comparable bond strength values. keywords: totalfill bc, guttacore, single cone, push out test. introduction various obturation procedures have been used to fill the root canal system over the years, but none was perfect. according to schilder, the optimal root canal obturating material must conform to the canal walls and irregularities (1). according to grossman, who investigated the physical qualities of filling materials, root canal sealers should have a high degree of adhesion(2). as caicedo and von fraunhofer reported, root canal sealants are essential for keeping the root canals from drying out(3). totalfill® bc sealer (fkg dentaire sa, la-chaux-de-fonds, switzerland) is a pre-mixed calcium silicate bioceramic sealer that cures to generate hydroxyapatite, which attaches to the root canal dentine surface as well as the bioceramic-coated gutta-percha points. totalfill® bc point, is a recently introduced hydrophilic sealer, composed of zirconium oxide, calcium silicates, calcium phosphate monobasic, calcium hydroxide, and various filling and thickening agents (4). it is possible to employ hydraulic condensation with a single cone approach because of its zero shrinkage and mild expansion; improved sealing is produced by joining bond bioceramic-coated gutta-percha points to the bioceramic sealer by chemical bonding (5). received date: 2-1-2022 accepted date: 4-2-2022 published date: 15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v34i3.3212 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3212 https://doi.org/10.26477/jbcd.v34i3.3212 j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 8 because of the irregular shape of the root canal, a single cone may be unable to completely seal the opening (6). the warm vertical technique and other thermoplasticized obturation are widely used by endodontists because of their efficiency in filling canal irregularities. because of the new calcium silicate– based sealers, many practitioners may favor a thermoplasticized method rather than the sc technique, despite the producers' advice. the impact of the thermoplasticized process on these sealers' sealing characteristics has yet to be assessed (7). the guttacore support is belongs to patented cross-linked gutta-percha and was created in 2010 (8). a carrier can combine the thermoplasticized gp and sealer horizontally and perpendicularly more quickly using this approach (9). the adhesion strength of the sealer and the appropriate technique used with it is important to achieve single adhesion unit (monoblock) and prevent any leakage. because there were limited studies regarding the effect of obturation techniques on bond strength and adhesion capacity of bioceramic totalfill sealer, therefore, the purpose of the current study was to evaluate and compare the effect of two warm obturation techniques, warm vertical compaction (wvc) and carrier-based obturation technique gutta core (gc) versus two cold obturation techniques, cold lateral compaction (clc) and (sc) on the push-out bond strength of bioceramic sealer (totalfill) at three different root levels. the null hypothesis was that there are no significant differences in the push-out bond strength of totalfill bioceramic sealer after different obturation techniques. materials and methods for this study, forty extracted maxillary first molars with round and straight palatal root canals and mature apices were used. the palatal roots were split vertically to the root's long axis at the furcation area to take a flat reference point for measurement. palatal roots were cut to achieve a standard length of 11 mm(10). size 20 k-file was utilized to define the initial size of the canal, edgeendo x7 rotary system files were used for instrumentation, starting with a size 20/04 rotary file, then 25/04, 30/04, 35/04, and 40/04 with a speed of 300 rpm and torque 300 g-cm till the working length (two–movement were used for each file) by gentle push in and out motion. between each rotary file, recapitulation was done with a size #20 hand k-file to keep the glide path and help the lubricant to reach the canal terminus. during canal preparation, 1 ml of 2.5%, naocl irrigation was used between instruments using a 30-gauge needle (side vented) 2 mm short of the working length to remove debris. after instrumentation, the canals were irrigated with 2 ml of 2.5% naocl(11). finally, 1 ml of edta 17% was used for 1 min agitation using sonic endoactivator(dentsply maillefer, switzerland) with irrigation tip size 25 followed by 3 ml of 2.5% naocl for 1 min agitation using sonic endoactivator. final rinsing with 5 ml saline solution(12). the samples were divided randomly into four groups based on the obturation methods (each group n = 10), group a: obturated by wvc, group b: gc, group c: clc, group d: sc group a: warm vertical compaction the canals were obturated with a bioceramic coated 40/04 master cone. an intracanal tip was used to apply bc (totalfill) sealer (fkg, dentaire, switzerland). the master cone was cut using a heated plugger (fi-p, woodpecker medical instrument co., guangxi, china)with a binding point of 4 mm short of the working length. it was just the apical portion of the gutta-percha that was maintained (4 mm). an injection of warm gutta-percha (fi-g, woodpecker medical instrument co., guangxi, china) set at 180°c j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 9 was used for the backfilling of the canal. a needle (40/04) was inserted into the root canal for 5 seconds and then the gutta-percha was extruded before.it could harden. finally, a plugger was used to compact the gutta-percha at the orifice level. each canal was treated with two gp pieces that had been heated to a high temperature (3 to 4 mm of gp). group b: guttacore obturator the bc sealer was inserted into the coronal one-third of the canal system with an intracanal tip. size 40 of the guttacore obturator was chosen and inserted into the thermaprep 2 oven's obturator holder (tulsa dental dentsply, tulsa ok, usa). the temperature of the oven was set according to the size of the obturator and the holder was pushed down in order to start thermoplasticzing the obturater. after several seconds, the obturator was ready to be used. after removing the obturator from the oven, it inserted into the working length of the canal with a downward pressing movement. it was necessary to bend the obturator's handle in both directions to remove extra material from the orifice. group c: cold lateral compaction bioceramic coated gp 40/04 master cones, and totalfill bc sealers (fkg, dentaire, switzerland) were used to seal the canals. an intracanal tip was inserted into the canals to insert the sealer in the coronal one-third (4 mm) of the canals. in the next step, a stainless-steel finger spreader size 25 (dentsply tulsa) was used to execute cold lateral-compaction, and tiny auxiliary gutta-percha cones (15 and 20) (diadent, north fraserway, burnaby, bc, canada)were introduced and condensed laterally to fill the canal space. finally, the cones were cut down to the same level as the orifice(13). group d: single cone bioceramic coated gp 40/04 cone and totalfill bc sealer was used to obturate the canals, as suggested by the manufacturer. the intracanal tip of the bc sealer was inserted into the coronal one-third of the canal. the cone was cut off at the level of the orifice and lightly packed vertically with a plugger to create a tight seal. the samples were wrapped in gauze and kept in an incubator at 37°c and 100% humidity for two weeks to confirm that the sealer had adequately solidified.(13) after that, three slices of 2 mm thickness were horizontally sectioned using a water-cooled precision saw (ernst-leitz, wetzlar, germany) with a diamond disk (0.5mm) thickness from root apex to include all roots at points 2, 4.5 and 7 mm level(14,15). for each segment, the apical and coronal diameters of the canal were measured using the imagej software analysis program (national institutes of health, usa). a digital caliper was used to verify the thickness of the section. the apical aspect per slice was compressed using a cylindrical plunger (punch pin) installed on a universal testing machine (z wick roell, germany). the maximal force in newton was measured at 0.5 mm/min in an apical-coronal direction until the initial dislodgement of obturating substance and a sharp decline along with the load deflection. punch pins with diameters of 0.7 mm, 0.5 mm, and 0.4 mm were used, calculated as 90% of canal diameter in the apical side of each root slice, the coronal, middle, and j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 10 apical slices. punch pins must almost entirely cover the central cone without touching the canal walls or sealer that was used (fig. 1). the maximal force (f-max) where the filing materials were dislodged was registered, and the strength of push-out bond (mpa) was computed per sample using the formula: strength of push-out bond (mpa) = f-max / area of adhesion surface (mm²) f-max: maximal force. the formula used to calculate the surface adhesion value is presented below.: area of adhesion surface = (d1 + d2/2) ×μ×h where d1=apicaldiameter,d2=coronal diameter, μ = 3.14, and h = the section thickness figure (1): schematic illustrates the push-out testing. evaluation mode of the failure following the push-out test, the specimens were examined under a 60 x magnification digital microscope to determine the failure forms (cohesive, adhesive, and mixed) that happened due to the stopper being displaced from the samples. failure was considered: adhesive after the sealer has been entirely removed from the dentine (dentine surface without sealer). cohesive if the sealer contained within it has become separated (dentine surface completely was covered by sealer). mixed, implying that both adhesive and cohesive modes are present at the same time (dentine surface partially covered by the sealer). statistical analysis: spss software for windows (version 25.0, ibm corp., armonk, ny, usa) was used for statistical analysis. the p<0.05 significance level was chosen. the study's primary outcome variable was bond strength in mpa. the information gathered was examined utilizing one way anova test, followed by tukey hsd comparison test. failure mode was an additional outcome variable. results table 1 and figure 2 display the mean and standard deviation of the bond strength (mpa) in groups. for the first technique (clc ), the highest mean values were recorded in the apical part (4.453)mpa followed by the middle (4.181)mpa, then the coronal part (3.003)mpa with a highly significant difference, for sc the mean strength of push-out was more elevated in coronal (4.205)mpa followed by apical (3.617)mpa then middle part (3.242) mpa. j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 11 regarding the other two obturation techniques, the situation was different, where the mean strength of push-out was higher in the apical part in (gc, wvc) (9.482, 8.119, respectively)mpa followed by the coronal (2.439)mpa, then the middle (2.191)mpa in gc technique and the middle (4.535)mpa, and finally the coronal in wvc (2.439)mpa technique again with highly significant difference (p<0.05). the differences in the strength of push-out bond at different root levels using different obturation techniques, according to one-way anova test, are shown in in table 1. in group clc, a statically significant difference was found between (coronal), (middle), and (apical) groups,(p=0.014). the apical third recorded the highest mean value, then the middle and the coronal third. in group sc, a statically significant difference was found between (coronal), (middle), and (apical) groups, (p=0.016). the coronal third was recorded as the highest mean value followed by the (apical) third, then the (middle) third. in group wvc, a statically significant difference was found between coronal, middle, and apical, (p=0.000). the apical third was recorded as the highest mean value followed by (middle) third, then (coronal) third. in group gc, a statically significant difference was found between coronal,middle,and apical groups, (p=0.000). the apical third was recorded as the highest mean value followed by (coronal) third, then (middle) third. table (1): descriptive and inferential statistics for the difference in the strength of push-out bond at different root levels using different obturation techniques. s:significant, hs:high significant, ns:non significant the statistical analysis employed the following levels of significance: ns p>0.05, s 0.05 p<0.01 hs. techniques levels descriptive statistics levels difference n mean s.d. f-test p-value clc apical 10 4.453 0.841 5.029 0.014 s middle 10 4.181 1.410 coronal 10 3.003 0.921 sc apical 10 3.617 0.548 4.834 0.016 s middle 10 3.242 0.726 coronal 10 4.205 0.796 wvc apical 10 8.119 1.136 67.401 0.000 hs middle 10 4.535 1.301 coronal 10 2.439 0.830 gc apical 10 9.482 1.239 99.426 0.000 hs middle 10 2.191 0.800 coronal 10 4.916 1.386 j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 12 0.000 2.000 4.000 6.000 8.000 10.000 12.000 clc sc wvc gc clc sc wvc gc clc sc wvc gc apical middle coronal m e a n ( m p a ) figure (2): the average bond strength values ( in mpa). regarding the effect of groups: in table 2 a) apical: there was a statistically high significant difference between clc and each of wvc, gc (p<0.001). a statistically low significant difference was found between wvc and gc (p<0.05). there was no statistical difference between clc and sc (p=0.242). b) middle: there was no statistically significant difference between clc with sc, wvc and sc with wvc and gc (p>0.05). a statistically high significant difference was found between clc and gc (p=0.001), and between wvc and gc (p=0.000). c) coronal: there was no statistically significant difference between clc with sc, wvc and between sc with gc (p>0.05). a statistically low significant difference was found between clc with gc, sc with wvc, wvc with gc (p<0.05). table (2): multiple comparisons among different obturation techniques using tukey's hsd test levels obturation techniques mean difference p-value apical clc sc 0.836 0.242 ns wvc -3.666 0.000 hs gc -5.029 0.000 hs sc wvc -4.502 0.000 hs gc -5.865 0.000 hs wvc gc -1.363 0.018 hs middle clc sc 0.939 0.243 ns wvc -0.354 0.889 ns gc 1.990 0.001 hs sc wvc -1.293 0.058 ns gc 1.051 0.162 ns wvc gc 2.344 0.000 hs coronal clc sc -1.202 0.054 ns wvc 0.564 0.602 ns gc -1.913 0.001 hs sc wvc 1.766 0.002 s gc -0.711 0.407 ns wvc gc -2.477 0.000 hs s:significant,hs: high significant, ns:non significant j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 13 failure mode the highest failure mode was recorded as follows: clc (cohesive), sc (cohesive), wvc (adhesive), and gc (cohesive) with no significant difference (fig. 3). figure (3): mode of failure a : adhesive (s\g), b: adhesive (d\s), c: mixed, d: cohesive(g). discussion root canal fillings are used to keep oral bacteria and their products from seeping into the apical periodontium and prevent bacteria that remain in the root canal afterward cleaning and shaping from escaping to the periapex (16). schilder conceived and described the thermoplastic root filling techniques, which are based on the vertical compaction of warm gutta-percha (17). the thermoplastic root filling techniques have been extensively studied and found to be beneficial in root canal system filling, filling material homogeneity, and apical seal (18) . in this study, bc sealer totalfill+bc coated gutta-percha (totalfill) was used to improve bonding by forming an actual gap-free seal single cohesive unit (monoblock) as claimed by trope et al., 2015(5). but the result demonstrates a reduction in bond strength in single cone and clc compared to wvc and gc, so the finding in this study disagrees with this monoblock idea. sem analysis was used to determine the adaptation of bc sealer to bc coated points and revealed an interfacial space between the bc sealer and the coated gp the chemical connection between the bc sealer and the coated gutta-percha point was investigated (19) .additional research utilizing various analytic tests is necessary to determine the degree of adhesion between the sealer and the coated point, as well as whether or not, it affects the quality of the root canal obturation. in this study, clc and sc have comparable bond strength mean values with no difference regarding the effect of root levels. this may back up the manufacturer's advice for totalfill bc, which recommends using totalfill bc sealer with a single hydraulic technique. according to the findings of this study, the highest mean values were obtained when the thermoplasticized gutta-percha obturation technique (wvc, gc) in all root levels except gc in the middle third which showed low bond value. these findings could be attributed to an increasing flow of warm gutta-percha, (20) resulting in a well-mixed bulk of gutta-percha and a small amount of sealer. this is frequently associated with an increase in material retention (17). several investigations also showed that the softening gutta-percha in thermoplasticized procedures had the flexibility to flow into deep depressions, lateral canals, auxiliary canals, and imperfections not filled by sealer cement (11). the thermoplasticized procedures produce more gutta-percha, less sealer, and fewer empty gaps than sc and clc. because most endodontic sealers are soluble and shrink slightly, it is better to rely on gutta percha material percentage in the apical c d a b j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 14 section as little as possible (13). the result of this study disagrees with (putrianti et al., 2020) study that found clc provides better adhesion ability than wvc (21). when there was no statistical significance difference among the tested levels regardless of the obturation materials used, this is in agreement with the results of (costa et al., 2010) who demonstrated that fluctuations in tubular density along the canal are inadequate to cause sealer adhesion to be affected (22). the most predominant mode of failure is cohesive failure mostly (gutta-percha) in totalfill bc except in wvc (adhesive) could be attributed to a thin layer of sealer incorporated in the dentinal tubules with some expansion due to the hydrophilic nature of the bc calcium silicate-based sealers have good adhesion to the root canal. wvc, gc reported high bond strength in totalfill bc with a highly significant difference especially apical third in gc. this could be explained by a very limited widening of the canal in the apical part, making it impossible to perform push-out tests without values having a frictional component with the canal walls (23). the adhesive mode of failure in wvc could be attributed to the sealer not being compacted against the root canal wall. guttacore's predominant failure mode was cohesive; this could be because the thermoplastic gutta-percha pierced the dentinal tubules, resulting in well-adapted root obturation, or it could be due to the composition of guttacore, which is composed of two layers of gutta-percha: an inner cross-linked layer and a flowable outer layer(24). conclusion the bond strength of totalfill bc sealer had a considerable influence on the obturation methods used in this study. to provide a high bond strength value,totalfill bc can be used with warm obturation procedures (guttacore, warm vertical technique). conflict of interest: none. references 1. schilder h. filling root canals in three dimensions. dent clin north am 1967:723-44. 2. grossman li. physical properties of root canal cements. j endod 1976;2(6):166-75. 3. caicedo r, von fraunhofer jjjoe. the properties of endodontic sealer cements. j endod 1988;14(11):527-34. 4. debelian g, trope mjgide. the use of premixed bioceramic materials in endodontics. g i d e 2016;30(2):70-80. 5. trope m, bunes a, debelian gjet. root filling materials and techniques: bioceramics a new hope? endod topics 2015;32(1):86-96. 6. celikten b, uzuntas cf, orhan ai, orhan k, tufenkci p, kursun s, et al. evaluation of root canal sealer filling quality using a single‐cone technique in oval shaped canals: an in vitro micro‐ct study. scaning 2016;38(2):133-40. 7. delong c, he j, woodmansey kfjjoe. the effect of obturation technique on the push-out bond strength of calcium silicate sealers. j endod 2015;41(3):385-8. 8. schroeder a, ford n, coil jjiej. micro‐computed tomography analysis of post space preparation in root canals filled with carrier‐based thermoplasticized gutta‐percha. int endod j 2017;50(3):293302. j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 15 9. hale r, gatti r, glickman gn, opperman lajijod. comparative analysis of carrier-based obturation and lateral compaction: a retrospective clinical outcomes study. int j dent 2012;8:954675. 10. alhashimi m .an evaluation of coronal microleakage in endodontically treated teeth using two different obturation techniques and two types of sealer at four different time periods. a master thesis, university of baghdad, 2005. 11. marciano m, ordinola‐zapata r, cunha t, duarte m, cavenago b, garcia r, et al. analysis of four gutta‐percha techniques used to fill mesial root canals of mandibular molars. int endod j 2011;44(4):321-9. 12. crumpton bj, goodell gg, mcclanahan sbjjoe. effects on smear layer and debris removal with varying volumes of 17% redta after rotary instrumentation. j endod 2005;31(7):536-8. 13. al-hiyasat as, alfirjani sajjod. the effect of obturation techniques on the push-out bond strength of a premixed bioceramic root canal sealer. j dent 2019;89:103169. 14. ehsani s, bolhari b, etemadi a, ghorbanzadeh a, sabet y, nosrat ajp, et al. the effect of er, cr: ysgg laser irradiation on the push-out bond strength of realseal self-etch sealer. photomed laser surg 2013;31(12):578-85. 15. elmuttalibi hf, mahdi jajjoo, research d. push out bond strength of guttaflow 2, thermafil and guttacore (an invitro study). j oral dent res 2019;6(1). 16. saunders w, saunders ejdt. coronal leakage as a cause of failure in root‐canal therapy: a review. dent traumtol1994;10(3):105-8. 17. schilder hjjoe. filling root canals in three dimensions. j endod 2006;32(4):281-90. 18. ungor m, onay e, orucoglu hjiej. push‐out bond strengths: the epiphany–resilon endodontic obturation system compared with different pairings of epiphany, resilon, ah plus and gutta‐ percha. int endod j 2006;39(8):643-7. 19. eltair m, pitchika v, hickel r, kühnisch j, diegritz cjcoi. evaluation of the interface between gutta-percha and two types of sealers using scanning electron microscopy (sem). clin oral investig 2018;22(4):1631-9. 20. venturi mjiej. evaluation of canal filling after using two warm vertical gutta‐percha compaction techniques in vivo: a preliminary study. int endod j 2006;39(7):538-46. 21. putrianti a, usman m, nazar k, meidyawati r, suprastiwi e, mahardhini sjijoap. effects of cold lateral versus warm vertical compaction obturation on the push-out bond strength of bioroot™, a calcium silicate-based sealer. int j appl pharm 2020:77-9. 22. costa j, rached‐júnior f, souza‐gabriel a, silva‐sousa y, sousa‐neto mjiej. push‐out strength of methacrylate resin‐based sealers to root canal walls. int endod j 2010;43(8):698-706. 23. babb br, loushine rj, bryan te, ames jm, causey ms, kim j, et al. bonding of self-adhesive (selfetching) root canal sealers to radicular dentin. j endod 2009;35(4):578-82 24. migliau g, sofan aaa, sofan eaa, cosma s, eramo s, gallottini ljads. root canal obturation: exper imental study on the thermafil system related to different irrigation protocols. ann stomatol 2014;5(3):91. j. bagh. coll. dent. vol. 34, no. 3. 2022 mounes and alhashimi 16 قوة رابطة الدفع للخارج للسداد الخزفي الحيوي )الملء الكلي( بعد تقنيات السد الدافئ والبارد دراسة مقارنة في المختبر بتول باسم مؤنس، رغد الهاشمي المستخلص: ( القائم على الناقل ، مقابل تقنيتي السد gc) gutta core( و wvcكان الهدف األساسي لهذه الدراسة هو تقييم ومقارنة تأثير تقنيتي السد الدافئ ، الضغط العمودي الدافئ ) بناًء على قوة رابطة دفع مانع التسرب الخزفي الحيوي عند ثالثة مستويات جذر مختلفة.( ، sc( و ، مخروط مفرد )clcالبارد ، الضغط الجانبي البارد ) ملم من 11تقسيم جذور الحنك إلى المواد والطرق: تم اختيار لهذه الدراسة أربعين ضرسًا مستخرًجا من الفك العلوي مع قناة جذر حنكي مستديرة مستقيمة بنهاية ناضجة. بعد .04تفتق 40حتى 20من edgeendo x7 rotary systemمم من قمة الجذر ، تم تحضير القنوات باستخدام ملفات 11. بعد تقسيم الجذور الحنكية إلى قمة الجذر ، b: gcلمجموعة ، ا wvc( ، مع المجموعة أ: مسد بواسطة 10ثم تم فصل العينات بشكل عشوائي إلى أربع مجموعات بناًء على إجراءات السد )كل مجموعة ن = تم قطع ثالث شرائح بسمك ٪ لمدة أسبوعين. 100درجة مئوية ورطوبة 37. بعد االنسداد ، تم االحتفاظ باألسنان في حاضنة عند d: sc، والمجموعة c: clcالمجموعة أحادي االتجاه واختبار anovaتحليل البيانات باستخدام اختبار تم مم من قمة الجذر في كل قسم من األقسام الثالثة )قمي ، وسط ، إكليلي(. 2،4.5،7مم أفقياً عند 2 tukey ( بمستوى معنويةp <0.05 تم استخدام مجهر رقمي مع تكبير .)60 x .لتحديد وضع الفشل ال سيما عند الثلث القمعي ) wvcو gcكانت هناك زيادة كبيرة في قوة رابطة الدفع بعد انسداد القناة باستخدام النتائج: ( ميجا باسكال ، مقارنة بالقنوات 9.48,8.11، ( مستوى معنوية. كان النمط المتماسك للفشل هو األكثر انتشاًرا في جميع الفئات. p< 0.05في جميع مستويات الجذر باستثناء الثلث األوسط ، ) clcو scالمسدودة بـ قابلة للمقارنة. clcو sc. كانت قيم قوة الرابطة لـ gcو wvc)الملء الكلي( قوة رابطة فائقة في bcى ، يُظهر مانع التسرب االستنتاجات: مقارنة بالتقنيات األخر j bagh college dentistry vol. 29(3), september 2017 validity of among among pedodontics, orthodontics and preventive dentistry 80 validity of digital and rapid prototyped orthodontic study models faten f. al-samarrai, b.d.s (a) iman i. al-sheakli, b.d.s. m.sc. (b) abstract background: the integration of modern computer-aided design and manufacturing technologies in diagnosis, treatment planning, and appliance construction is changing the way in which orthodontic treatment is provided to patients. the aim of this study is to assess the validity of digital and rapid prototyped orthodontic study models as compared to their original stone models. materials and methods: the sample of the study consisted of 30 study models with well-aligned, angle class i malocclusion. the models were digitized with desktop scanner to create digital models. digital files were then converted to plastic physical casts using prototyping machine, which utilizes the fused deposition modeling technology. polylactic acid polymer was chosen as the printing material. twenty four linear measurements were taken from digital and prototyped models and were compared to their original stone models “the gold standard”, utilizing the paired sample t-test and bland-altman plots. results: eighteen of the twenty four variables showed non-significant differences when digital models were compared to stone models. the levels of agreement between the two methods showed that all differences were within the clinically accepted limits. for prototyped models, more than half of the variables differed in non-significant amount. the levels of agreement were also within the clinically accepted limits. conclusion: digital orthodontic study models are accurate in measuring the selected variables and they have the potential to replace conventional stone models. the selected rapid prototyping technique proved to be accurate in term of diagnosis and might be suitable for some appliance construction. keywords: digital models, rapid prototyping, orthodontic diagnosis. (j bagh coll dentistry 2017; 29(3):80-85) introduction orthodontic study models are important part of diagnostic armamentarium, they provide a stable and accurate representation of human dentition and their surrounding structures (1-3). despite their importance, they are associated with drawbacks, such as considerable space required for storage, the heavy weight and brittle nature of gypsum products made them subjected to fracture and cumbersome in handling and long distance communication with other professionals (4-6). researchers tried to find alternatives to conventional models with many approaches namely: photocopying (7-9), digital photography (10), hologram (11), stereo-photogram (12) , threedimensional contact digitizers (13,14) and optical scanners (15). with optical scanners, it is possible to create digital models by directly scanning the patient’s teeth or indirectly scanning the cast or impression (16,17). digital models allow the orthodontists to perform space analysis and treatment setups virtually and they eliminate storage problems associated with stone models. additionally, they open the way for computer aided appliance manufacturing (18-20). however, for digital models to completely replace traditional models, they have to be accurate and it should be possible to re (a) master student. department of orthodontics. college of dentistry, university of baghdad. (b) assistant professor. department of orthodontics. college of dentistry, university of baghdad trieve a physical representation of the model if needed for legal purposes or appliance design (21,22). fortunately, with rapid prototyping, it is now possible to fabricate physical model from digital files, in this technology computer aided machines creates study models from substrate materials in an additive or subtractive manner depending on the original geometry of the digital models (23-25). additive rapid prototyping or (threedimensional printing) is the process of building solid object from digital file by incremental layering, the basic idea involves slicing the digital model into thin slices with sophisticated software and send these slices to a 3d printer controlled by computer (25). additive technology includes different manufacturing techniques namely: fused deposition modeling (fdm), stereolithography (sla), digital light projector (dlp), poly jet photopolymer (ppp), selective electron beam melting (sebm) and laser powder forming techniques (26,27). in additive manufacturing, fine details such as undercuts, voids, and complex internal geometries are efficiently reproduced, besides no or very little substrate material get wasted in the process. however, the techniques are time-consuming and rather expensive (28). the subtractive technology utilizes computer numerically controlled machines (cnc) that have sharp cutting tools to mechanically cut away material and achieve the desired geometry, with all steps controlled by computer software programs (23). cutting tools j bagh college dentistry vol. 29(3), september 2017 validity of among among pedodontics, orthodontics and preventive dentistry 81 could be burs, water jet, laser or electron beam cutting. subtractive manufacturing techniques take less time than additive but they are wasteful procedures as a large amount of material is wasted during manufacturing (29). the digital models and its rapid prototyped replicas are becoming increasingly popular among orthodontic clinics as a part of modern trends toward incorporating modern technologies intoevery day practice. however, for any new diagnostic set, it has to be accurate before it can be implemented into clinical practice. this study was conducted to assess the validity of digital models required with astructured light desktop scanner and their rapid prototyped replicas. materials and methods thirty patients who fulfilled the selection criteria were chosen for this study. the selection criteria included; angle class i malocclusion (30) with well-aligned dentition, no fillings, extractions, large carious lesions, attachments, prosthesis nor history of previous orthodontic treatment (18,31-33). after describing the purposes of the study; signed ethical approval of participation was taken from each patient. stone models preperation impressions for both arches were taken using alginate (hydrogum®. zhermack, italy), with suitable disposable plastic tray. impressions were disinfected with sodium hypochlorite (1/10) (34), wrapped in a wet towel and stored in closed plastic bag. the bite was registered using wax (base plate wax, china), warmed with hot water and rolled to arch form (35). dental stone (elite® model. zhermack, italy) was used to pour the impression according to manufacturer instructions. time elapsed between impression taking and pouring was less than 1 hour (36). thin consistency of plaster of pairs was used to create the model bases, the base was then trimmed according to bite registration. digital models preperation dental study models were sent to a laboratory equipped with desktop dental scanner (ineox5, sirona®, germany), which was connected to a computer that had sirona inlap® software fully activated and functional to control the scanning process. scanning dental models involved in three steps; first maxillary and mandibular casts are scanned separately, the second step involves articulating the maxillary and mandibular arches by utilizing the ‘bite registration algorithm’. finally, the digital models were exported in .stl (standard tessellation language) file format to be successfully integrated into space analysis software. rapid prototyping digital models were sent by electronic mail to engineering facility equipped with three dimensional printer (micromake® china). the printing material used was polylactic acid (pla) polymer. measuring procedure linear measurements were taken (first molar width, canine width, central incisor width, intermolar width, inter-canine width, posterior and anterior arch length), measurement were made on both arches and from right and left sides, which gave a total of 24 measurements. stone and prototyped models were measured using digital caliper with sharpened peaks according to the method described by hunter and priest (37). anatomical contact points and cusps tips were marked with a fine pencil to improve accuracy. digital models were measured using orthoselect® (version 2.9) analysis software, zoom and rotation functions were utilized when needed to gain better visualization of landmarks. statistical analysis paired sample t-test was used to compare between stone, digital and rapid prototyped models measurements in term of systematic errors (table 1). the bland-altman test (38,39) was used to assess the level of agreement between the three types of models in term of random errors (table 2). results when stone models were compared with digital models 18 out of 24 of the variables showed non-significant differences. most of the variables appeared to be larger on digital models, indicated by the negative mean differences. the mean differences in tooth width were (0.1mm-0.07mm), for arch width (-0.4mm 0.03mm) and for arch length (-0.18mm-0.08mm). the biases were (-0.02mm, -0.21mm, -0.08mm) for tooth width, arch width, and arch length respectively. limits of agreements were about (∓0.3mm, ∓0.9mm, ∓0.7mm). replicated models were compared to their original stone models (table 1). more than half of the variables differ in non-significant amount with mean differences range between (-0.04mmj bagh college dentistry vol. 29(3), september 2017 validity of among among pedodontics, orthodontics and preventive dentistry 82 0.05mm) for teeth width, (0.15mm-0.27mm) for arch width, (-0.08mm 0.1mm) for arch length. blandaltman plot revealed that tooth width had a negative bias (-0.001mm), indicating that it scored larger on replica while arch dimensions were smaller as indicated by their positive bias (0.23mm,0.05mm). limits of agreements were about (∓0.28mm, ∓0.9 mm, ∓0.5mm) for teeth width, arch width, and arch length. table 1: descriptive data and paired sample t-test r: right, l: left, 6: first molar width, 3: canine width, 1: central incisor width, icd: inter canine width, imd: inter-molar width, pal: posterior arch length, aal: anterior arch length. all measurements in mm *statistically significant table 2bland – altman test variable digital models vs stone models prototyped models vs stone models bias levels of agreement bias levels of agreement teeth width -0.02mm ∓0.3mm -0.001mm ∓0.28mm arch width -0.21mm ∓0.9mm 0.23mm ∓0.9 mm, arch length -0.08mm ∓0.7mm 0.05mm ∓0.5mm discussion dental study model is the cornerstone in orthodontic diagnosis with long and proven history, but its associated drawbacks gave the rise to digital alternatives. however, the digital model has to be accurate to replace the stone model and physical replication should be possible if needed. in this study, the accuracy of digital models scanned with locally available laboratory scanner was assessed in addition to the validity of rapid prototyped models that were replicated with additive manufacturing technology. a sample size of 30 model was considered sufficient to study the validity (40-42). the variables were selected to give a representative set of measurements from all aspects of the model (right buccal, left buccal, canine region, frontal and occlusal aspects), in order to make sure that there is no data missing in all aspects of digital models and no error in printed models in all planes of space (43,44). variables stone models digital models vs. stone models prototyped models vs. stone models mean sd mean sd difference pvalue mean sd difference p value m a x il la t e e th w id th r6 9.74 0.58 9.84 0.57 -0.102 0.01* 9.79 0.61 -0.048 0.04* l6 9.72 0.65 9.71 0.63 0.001 0.96 9.75 0.63 -0.038 0.10 r3 7.94 0.44 7.96 0.55 -0.020 0.52 7.94 0.42 -0.002 0.96 l3 7.81 0.54 7.88 0.58 -0.073 0.04* 7.82 0.53 -0.012 0.66 r1 8.71 0.67 8.66 0.62 0.054 0.13 8.71 0.62 0.004 0.89 l1 8.79 0.71 8.72 0.68 0.072 0.03* 8.74 0.73 0.057 0.04* arch width icd 34.72 3.23 34.88 3.29 -0.163 0.06 34.44 3.35 0.278 0.00* imd 51.55 3.30 52.02 3.21 -0.466 0.00* 51.29 3.29 0.256 0.02* a r c h le n g th rpal 13.62 0.84 13.80 0.86 -0.180 0.00* 13.70 0.90 -0.085 0.17 lpal 13.80 0.79 13.89 0.87 -0.095 0.07 13.66 0.88 0.143 0.01* raal 23.59 1.84 23.54 1.76 0.051 0.40 23.50 1.76 0.090 0.04* laal 23.58 1.80 23.49 1.92 0.084 0.09 23.55 1.89 0.033 0.39 m a n d ib le t e e th w id th r6 10.81 0.72 10.87 0.70 -0.066 0.06 10.76 0.71 0.049 0.03* l6 10.89 0.74 10.92 0.67 -0.030 0.41 10.91 0.73 -0.016 0.41 r3 6.90 0.48 6.89 0.54 0.002 0.94 6.88 0.47 0.018 0.58 l3 6.90 0.43 6.94 0.51 -0.039 0.21 6.92 0.44 -0.017 0.60 r1 5.35 0.36 5.38 0.37 -0.028 0.41 5.34 0.36 0.011 0.54 l1 5.35 0.36 5.38 0.37 -0.029 0.30 5.37 0.32 -0.022 0.37 arch width icd 26.30 2.39 26.27 2.48 0.033 0.65 26.15 2.52 0.157 0.12 imd 45.13 3.23 45.35 3.36 -0.224 0.07 44.88 3.34 0.246 0.03* a r c h le n g th rpal 14.23 0.74 14.35 0.80 -0.119 0.02* 14.24 0.78 -0.007 0.86 lpal 14.41 0.83 14.57 0.74 -0.161 0.06 14.27 0.78 0.140 0.06 raal 17.77 1.12 17.88 1.06 -0.109 0.07 17.78 1.05 -0.011 0.74 laal 17.59 1.23 17.70 1.33 -0.106 0.07 9.79 0.61 -0.048 0.04* j bagh college dentistry vol. 29(3), september 2017 validity of among among pedodontics, orthodontics and preventive dentistry 83 validity was considered as the extent to which digital and prototyped models measured against the stone models “the gold standard“ (45). the clinically acceptable limit of differences between the tested model and stone models is < 0.5 mm for teeth width, and < 5% for mean of arch dimensions (18,44, 46-49). the mean differences of all variable indicating that some measurements were larger on digital models as compared with stone models other were smaller, this could be attributed to errors in landmarks identification (6, 42,50). many causes of error that were reported in the previous studies were avoided in this study. the same cast that was scanned used for manual measurements and no differences could be attributed to the materials. the operator was well trained and calibrated and landmarks were carefully identified. nevertheless, variation still exists, this could be explained by the difficulty of measuring three-dimensional objects on a twodimensional computer screen (51-54). additionally, arch width suffered the greater range of differences among all variable. jacquet et al. (55) explained that locating the tip of the cusp on digital models is difficult and may be affected by many technical features of the computer and software. mean differences for all variables ranged between (-0.46mm-0.08mm), this is close to the range reported in previous studies (22,47,56). the biases and levels of agreement reported by bland–altman test indicated that all the differences within the clinically acceptable limits. both models (digital and stone) can be used for diagnostic purposes interchangeably in well-aligned arches. for prototyped models, the mean differences of all variables ranged from (-0.08mm-0.27mm), this came in accordance to kasprova et al. (43). arch width suffered the greatest variation and it had a positive bias indicating that it was smaller on the prototyped replicas, also it had the widest levels of agreement. the cause of this variation is the measurements of arch width depend on the identification of the cusps tips which were rather difficult to identify on the prototyped models, since the occlusal surface is the last layer to be deposited by the printer head it will be subjected to the greatest variations. the same finding was described by keating et al. (41). however, all differences lie within the clinically accepted limits and prototyped models are a valid alternative to stone models in term of orthodontic diagnosis (21,43,57). in conclusion; digital study models are valid alternative to stone models with clinically acceptable accuracy in measuring teeth width and arch dimensions, and rapid prototyped models have acceptable validity and in term of diagnosis and it could be applicable in the construction of selected types of appliances. references 1. singh g. textbook of orthodontics. 2nd ed. india: jaypee brothers publishers; 2007. p.76-93. 2. horton hm, miller jr, gaillard pr, larson be. technique comparison for efficient orthodontic tooth measurements using digital models. angle orthod 2010; 80(2): 254-61. 3. peluso mj, josell sd, levine sw, lorei bj. digital models: an introduction. semin orthod 2004;10(3): 226-38. 4. machen de. legal aspects of orthodontic practice: risk management concepts. am j orthod dentofacial orthop 1991; 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145(11): 1133-40. الخالصة: ا جذريا في أسالبيب عه االجهزه التقويميه, أحدث تغيرالخلفيه: ان التوافق الحاصل بين علوم الحاسوب الحديثه وتقويم االسنان من حيث التشخيص والعالج وصنا نوعه بتقنيه الطباعه ثالثيه االبعاد عن طريق تقيم دقه النماذج التشخيصيه التقويميه والنماذج المص للمرضى. الهدف من هذه الدراسه هوتقديم العالج التقومي .مقارنتهما مع النماذج االعتياديه المصنوعه من المشتقات الجبسيه الطباق.تم تحويل النماذج الجبسيه ا وءالترتيب وتقع ضمن النمط االول لساز االسنان فيها بكونها حسنه تمت نموذج تشخيصي , 03المواد والطرق: تتكون العينه من مد في عملها على تقنيه الى ملفات رقميه بأستخدام جهاز الماسح الضوئي. النماذج الرقميه حولت الى مجسمات بالستيكيه بأستخدام طابعه ثالثيه االبعاد التي تعت من كل نموذج من النماذج اخطي اقياس اربع و عشرونلطباعه. تم أخذ الصهروالصب والترسيب. تم أستخدام بوليمر حمض الالكتيك المتعدد كماده اساسيه في ا .الرقميه والمطبوعه حاسوبيا وقورنت مع نفس القياسات المأخوذه من النماذج الجبسية وضحت ان جميع الفروقات تقع متغير. مستويات التوافق بين النموذجين أ 42من اصل 18النتائج: مقارنه النماذج الرقميه والجبسيه لم تبين اي فرق معنوي في المتغيرات لم تبين أي فرق معنوي عندما قورنت مع النماذج الجبسيه. مستويات أكثر من نصفضمن الحدود المقبوله عمليا. بالنسبه للنماذج المصنعه حاسوبيا .التوافق كانت أيضا ضمن الحد المقبول عمليا ياس المتغيرات المختاره في هذه الدراسة. ومن الممكن أستخدامها كبدائل عن النماذج الجبسيه التقليديه.تقنيه الطباعه االستنتاجات:النماذج الرقميه تتصف بدقه كافيه لق .ميهثالثيه االبعاد المستخدمه في هذه الدراسه تتمتاز بدقه كافيه لصناعه النماذج التشخيصيه. وقد تكون مناسبه لصناعه بعض االجهزه التقوي : النماذج الرقمية,طباعه ثالثيه االبعاد,التشخيص التقويميالكلمات الرئيسيه j bagh college dentistry vol. 32(1), march 2020 radiological age 57 radiological age estimation using third molars mineralization in a sample attending orthodontic clinics (a retrospective study) zainab mousa kadhom (1) abstract background: the evaluation of the chronological age is a practical method in crime investigation field that assists in identifying individuals to treat them as underage or adult. this study aimed to assess the stages of third molars mineralization in relation to chronological age of iraqi individuals, determine the gender differences and arches (maxillary/mandibular) differences. materials and methods: a total of 300 orthopantomograms of orthodontic patients were collected according to specific criteria and evaluated visually. the developmental stages of maxillary and mandibular third molars were determined according to demirjian method. the chronological age was recorded according to the particular mineralization stages at which it reached considering genders, sides and jaws. comparisons were done using paired sample and independent sample t-tests. results: results showed that there was no statistically significant difference (p>0.05) between maxillary and mandibular third molars. the maxillary third molars reached earlier than mandibular one in stages f and g. there was no significant difference between the mean ages of males and females at each given developmental stage in the maxillary and mandibular third molars except for the stage d in the maxilla and stages d and e in the mandible. the development of third molar teeth on the right and left sides was similar except for the maxillary arch in males when there was a significant difference in stage c and d and stage e in the mandibular arch. conclusion: the demirjian method is an excellent approach for age assessment using orthopantomogram. all of the differences between the current study and other studies could be because of the difference in the populations who were chosen from different geographical areas. keywords: age estimation, demirjian method, third molar, orthopantomogram, chronological age. (received: 1/7/2019; accepted: 29/8/2019) introduction over the last period of time, the forensic age estimation in living people has gained great importance.(1) mostly the forensic age can be legally determined in several countries between 14 and 21 years without recognizing any documents. it is very important to use dental analysis as an approach in the medical detection of the crime because the bone and other tissues have already been destroyed whilst the most material in the individual body that can remain and resist to be analyzed is teeth.(2) however, to determine the age of the individual, different methods have been evolved and one of these methods is the morphology of the cervical vertebrae,(3) added to that person`s general physical development.(4,5) an x-ray of the left hand represented an independent part participated by forensically experienced experts in age assessment of the individuals.(6) moreover, the teeth are regarded as a means for the chronological age determination in the populations. what can be seen, the radiological and the clinical examination of the apparent and morphological dental variations throughout life can become a basis in age evaluation.(7) (1) assistant lecturer, department of orthodontics, college of dentistry, university of baghdad. so, generally, in young adults and youths, the chronological age evaluation can use dental development as the most acceptable and reliable method.(8) in-vivo, the radiological approach in the estimation of the dental development is a quick, non-invasive and simple process for investigation.(5,9) furthermore, the orthopantomogram (opg) acts as a reliable method to assess the age as it is used in determining the stage of dental mineralization.(5,10) the third molar is a tooth distinguished by the variability in the time of its formation and by its varying presence or absence in the oral cavity,(11) and the forensic important is a fundamental property of this tooth since it developed continuously over a long time.(8,12) at the same time after about 14 years old, all the permanent dentitions would have finished their development, except the third molar; therefore, age assessments become complicated in this period.(12) the eight-stage scheme (figure 1) designed by demirjian et al. (5) was very simple, precise, and did not require more mediation to estimate the age.(13) also, by this method, one can compare between different ethnic groups.(14) there are different studies(12,13,15) that address age assessment by third molar mineralization, using demirjian et al. (5) approach. no previous study has assessed chronological age by using the third molar in iraq, except one study that assessed the interrelationships among the chronological age, j bagh college dentistry vol. 32(1), march 2020 radiological age 58 dental, and skeletal maturation, conducted on all permanent teeth except third molars.(16) this study aimed to assess the mineralization stages of third molars concerning the chronological age of iraqi individuals and to determine the gender and arches (maxillary/mandibular) differences. materials and methods the study sample of this research was selected from iraqi out patients who have attended the department of orthodontics at the college of dentistry, university of baghdad, and two private orthodontic clinics in baghdad and karbal'a cities between 2015 and 2018. out of the 600 opgs collected and examined, only 300 patients (150 males and 150 females) with known chronologic age (10-24 years old) were selected in this study. gravely (11) founded that the age of nine years is the top of the formation period of the third molar, for that 10 years old was considered the age limit and an accurate radiological guide of the third molar in this study. according to hofmann et al.,(15) the exclusion criteria of this study were: • germectomy, agenesis and extraction of all four third molars. • participant age less than 10 years or more than 24 years. • possibility of the local, genetic exogenous or systemic factors that have effects on dental development and the facial clefts or any other craniofacial syndromes and the presence of dental pathologies like tumors or cysts as seen in the radiographs. • opgs with bad image quality.(17) the opgs which were taken as a diagnostic aid for orthodontic treatment were selected randomly and evaluated visually.(18) patients’ chronological age at the time of opg taking, gender, third molars germs locations and mineralization stage from a to h were recorded according to demirjian et al.(5) the full description of each stage was explained and illustrated in table 1 and figure 1. no additional subgrouping of stages c, d, e, f and h were done.(15) table 1: radiological mineralization stages of permanent teeth as presented by demirjian et al. (5) stage definition a the calcification begins firstly at the superior level of the crypt in the form of an inverted cone or cones, in both uniradicular and multiradicular teeth. there is no fusion of these calcified points. b fusion of the calcified points forms one or many cusps, which unite to give an orderly outlined occlusal surface. c a. enamel formation is finished at the occlusal surface. an extension and convergence towards the cervical region are seen. b. the dentin begins to deposit. c. at the occlusal border the outline of the pulp chamber has a curved shape. d a. the crown formation is accomplished down to the cemento-enamel junction. b. in uniradicular teeth, the superior border of the pulp chamber has a specific curved form, being concave towards the cervical region. the prominence of the pulp horns is present, creating an outline shaped like an umbrella top. in molars, the pulp chamber has a trapezoidal form. c. the root formation starts to begin in a form of spicule. e a. uniradicular teeth: the walls of the pulp chamber now form straight lines, whose continuity is broken by the presence of the pulp horn, which is larger compared to the previous stage. molars: initial formation of the radicular bifurcation is seen in the form of either a calcified point or a semilunar shape. b. uniradicular teeth: the crown height is more than the root length. molars: the root length is still less than the crown height. f a. uniradicular teeth: the walls of the pulp chamber now form a more or less isosceles triangle. the apex ends in a funnel shape. molars: the calcified region of the bifurcation has developed further down to give the roots a more definite and distinct outline with funnel shaped ends. b. uniradicular teeth: the walls of the pulp chamber are equal to or greater than the crown height. molars: the crown height is equal to or less than the root length. g a. the walls of the root canal are now parallel and its apical end is still partially open (distal root in molars). h a. the apical end of the root canal is closed completely (distal root in molars). b. the periodontal membrane has a regular width around the root and the apex. the stages of development determined by opg from a to h were corresponded with a particular point of score of the gender and jaw depended on demirjian et al. method.(5) this score point clarified the chronological age where the appropriate stages of mineralization reached. statistical analyses the collected data were analyzed with the aid of spss program (version 15, spss inc., usa). for each stage, the means, standard deviations, minimum and maximum values were obtained. j bagh college dentistry vol. 32(1), march 2020 radiological age 59 the gender and arches differences were determined using independent sample t-test, while side difference was detected using paired sample ttest. the probability value was set at 0.05. figure 1: third molars' mineralization stages.(5) results about 600 opgs images have been collected for this study between 2015 and 2018. many of these opgs contained congenitally missing third molar germs or all four third molars or these teeth may have been influenced by many exogenous and genetic factors during development. some of the opgs were not clear. too, some of these images were for the patients with age less or more than the age range of this study; therefore, about 300 opgs had to be excluded and only 300 opgs were selected pertinent to 150 males and 150 females with known chronologic age ranged from 10-24 years. the landmarks of tooth formation expressed as: initial calcification (stage a), the completion of the crown (stage d), and formation of inter-radicular bifurcation (stage e), root-length completion (stage g), and close of the apex (stage h). descriptive statistics and comparison of age between the maxilla and mandible were shown in table (2). the results statistically showed no significant difference (p>0.05) between maxillary and mandibular third molars. the mean age of stage d was 14.272 years and stage f was 16.794 years in the maxilla and in the mandible was 13.833 years for stage d and 17.128 years for f stage. initial calcification, the first stage of the developmental level (stage a) according to demirjian’s method, was seen at the age between 10 and 16 years. also, in both arches, minimal age for appearance of both stages b and c was 10 years and for stages e and g was 12 years. moreover, from the mean ages in both arches, the maxillary third molars reached earlier than lower third molars in stages f and g only. the apex of the maxillary third molars closed (stage h) at the mean age of 21.127 years and the mandibular third molars at 21.049 years. descriptive statistics and gender difference of the age in all developmental stages (a to h) for the maxillary and mandibular third molars were showed in tables (3 & 4). stage b was first appeared at 12.080 years in the maxillary arch of females and at 10.857 years in the mandible, while in males, the appearance of this stage was at 11.800 years in the maxillary arch and 11.400 years in the mandibular jaw. the mean ages of males and females were not significantly different at each given developmental stage of the maxillary and mandibular third molar except for stage d in the maxillary arch and stages d and e in the mandible when males were significantly earlier to reach these stages than females. the side differences in each gender were presented in tables (5 & 6). the development of third molar teeth on the right and left sides was similar in both genders except for the maxillary arch in males; there was a significant difference in stage c and d and stage e in the mandibular arch. j bagh college dentistry vol. 32(1), march 2020 radiological age 60 table 2: descriptive statistics and arch difference of the age (in years) in whole sample. stages maxilla mandible comparison mean min max s.d. mean s.d. min max t-test p-value a 11.600 10 16 2.503 11.167 1.899 10 16 0.308 0.766 b 11.956 10 16 1.941 11.259 1.631 10 16 0.673 0.516 c 12.976 10 17 1.801 12.921 1.826 10 18 0.101 0.920 d 14.272 10 20 2.201 13.833 2.034 11 20 1.086 0.279 e 15.982 12 23 2.240 15.779 2.002 12 23 0.309 0.758 f 16.794 14 23 1.705 17.128 1.957 13 23 -0.705 0.484 g 19.027 12 24 2.477 19.486 2.263 12 24 -0.684 0.497 h 21.127 17 24 1.777 21.049 1.931 12 24 0.325 0.745 table 3: descriptive statistics and gender difference of age (in years) for different developmental stages of maxillary third molars stages male female gender difference mean s.d. min. max. mean s.d. min. max. t-test p-value a 10.500 1.225 10 13 13.250 3.202 10 16 -1.948 0.184 b 11.800 1.473 10 14 12.080 2.272 10 16 -0.476 0.620 c 12.806 1.754 10 17 13.476 1.887 10 16 -1.484 0.142 d 13.030 1.858 10 20 15.147 2 12 20 -6.832 0.000 e 16.143 2.265 12 20 15.889 2.252 13 23 0.41 0.684 f 17.152 1.679 14 20 16.400 1.673 14 23 1.777 0.081 g 18.583 2.827 12 23 19.240 2.291 14 24 -1.069 0.289 h 21.058 1.773 17 24 21.244 1.800 18 24 -0.529 0.598 table 4: descriptive statistics and gender difference of age (in years) for different developmental stages of mandibular third molars stages male female gender difference mean s.d. min. max. mean s.d. min. max. t-test p-value a 10.889 1.269 10 13 12 3.464 10 16 -0.544 0.637 b 11.400 1.392 10 14 10.857 2.268 10 16 0.751 0.459 c 12.607 1.592 10 17 13.311 2.032 10 18 -1.902 0.061 d 13.140 1.995 11 20 14.460 1.874 12 20 -3.737 0.000 e 15.200 1.883 12 18 16.089 2.012 13 23 -1.997 0.049 f 17.184 1.722 14 20 17.083 2.142 13 23 0.236 0.814 g 18.931 2.389 12 23 19.878 2.112 16 24 -1.75 0.085 h 21.127 2.012 12 24 20.923 1.812 17 24 0.516 0.607 table 5: descriptive statistics and side difference of the age (in years) for each developmental stages of maxillary and mandibular third molar in males jaw stages descriptive statistics side difference right left mean s.d. mean s.d. t-test p-value maxilla a 10.750 1.500 13.250 3.202 -1.213 0.312 b 11.889 1.453 11.778 1.563 0.164 0.873 c 12.238 1.513 13.476 1.887 -2.540 0.020 d 12.836 1.619 15.491 2.098 -6.480 0.000 e 16.143 2.265 16.095 2.567 0.059 0.953 f 16.967 1.629 16.400 1.673 1.505 0.143 g 18.583 2.827 19.667 2.239 -1.511 0.144 h 20.971 1.834 21.234 1.671 -0.626 0.536 mandible a 10.333 0.577 12 3.464 -0.762 0.525 b 11.286 1.254 10.857 2.268 0.372 0.723 c 12.615 1.602 13.577 1.922 -1.932 0.065 d 13.000 1.600 12.885 1.904 0.223 0.826 e 15.200 1.883 16.400 2.372 -2.320 0.028 f 17.184 1.722 16.974 2.236 0.428 0.671 g 19.474 1.982 19.842 2.363 -0.538 0.597 h 21.258 1.632 21.000 2.380 0.903 0.374 j bagh college dentistry vol. 32(1), march 2020 radiological age 61 table 6: descriptive statistics and side difference of the age (in years) for each developmental stages of maxillary and mandibular third molar in females jaw stages descriptive statistics side difference right left mean s.d. mean s.d. t-test p-value maxilla a 10 0 10.500 0.707 -1 0.5 b 12.900 3.479 12.800 3.553 0.061 0.953 c 12.839 1.899 12.774 1.627 0.193 0.848 d 12.818 1.509 13.152 2.123 -1.146 0.260 e 16.400 2.171 15.800 2.530 0.874 0.405 f 17.250 1.807 17.063 1.652 1.379 0.188 g 18.727 3.036 18.273 2.760 0.612 0.554 h 20.939 1.853 21.182 1.740 -0.928 0.360 mandible a 11 1.414 11 1.414 b 11.333 1.323 11.333 1.323 c 12.654 1.548 12.654 1.548 d 13.222 2.082 13.222 2.082 e 14.923 2.019 14.923 2.019 f 17.278 1.708 17.278 1.708 g 18.571 2.821 18.571 2.821 h 21.3 1.601 21.3 1.601 discussion the use of tooth developmental stages is considered as an accurate method of chronological age determination adopted over a long time independent of disease or malnutrition and other exogenic factors.(9) the author depended on the third molar formation to assess the chronological age of the subjects due to the lack of different processes through the duration between the teenagers and early 20s.(19) it is very useful to use third molar mineralization stages in chronological age evaluation especially for the legal purposes of unknown victims.(20) all selected opgs belong to iraqi outpatients attended the department of orthodontics at the college of dentistry and two private orthodontic clinics. the age ranged between 10-24 years since many patients at this age attend orthodontic clinics seeking orthodontic treatment. stage a in the current research is initiated at 10 years old. this is near to that reported in the thai population(21) (9.75 years old) and later than jung and cho (22) (7 years of age). the results of the present study showed that stage d (crown completion) reached at age of 14.27 years in the maxilla and 13.83 years in the mandible. this result was somewhat close to that reported in iranian population (23) (13.62 years) and earlier than thai population(19) (15.47 years) and later than turkish population (24) (12.90 years). this could be attributed to the difference in ethnic groups. in the present study, the root formation (stage h) was completed at a mean age of 21.12 years in the maxilla and of 21.04 years in the mandible. these results were almost close to that of caucasian central europa,(15) while earlier than the turkish subjects reached this stage at 22 years.(24) regarding gender differences in this stage, the mandibular third molars in females began stage h at 20.9 years which was earlier than males in contrast to sujatha et al.(17) who reported that males reached this stage earlier than females. khosronejad et al.(18) and hassan and abo hamilla (25) supported the findings of the current study when the iranian females reached certain third molar mineralization stages (only the h stage) sooner than males and in egyptian females, all third molars reached h stage earlier than males. it becomes clear from the mean ages in both arches that at stages a-f, the subjects were probably below 18 and at stage g and h, the individuals were above 18 years; this comes in agreement with jung and cho(22) who reported that korean population exhibited stage g at age of 18 years or older, and khosronejad et al.(18) who found that both g and h stages could indicate that the person might be above 18 years old. other studies(26,27) showed that at stage a-d, persons were probably below 18 years and at stage h and they were above 18 years. this may be due to differences in the third molars development.(28) a study by hofmann et al.(15) showed that girls seem to achieve the mineralization stage c at a slightly earlier age than boys. sujatha et al.(17) also reported that stage d was early in males and stage g in females while in the turkish population, both d and g stages were earlier in males than females.(24) in the present study, the development of third molars in all stages was earlier in males j bagh college dentistry vol. 32(1), march 2020 radiological age 62 than females except the maxillary third molars in stages e and f and in stage b, f and h in the mandibular third molar where females were earlier than males. this is supported by the findings of darji et al. (29) who found that teeth in males were calcified earlier than in females. this is unrivaled detection for the third molar as all other permanent teeth development is earlier in females as compared to males. the results in terms of gender differences showed no significant difference in the developmental stages of the third molar between males and females except in stage d in the maxilla and stages d and e in the mandible since the females reached these three stages later than males. the highest difference was seen at stage d in the maxilla when males were 2.117 years ahead of females. these results come in agreement with many studies as in thai populations(21) where the mandibular third molar in stage e was significantly higher in female, also both of sisman et al.(24) and rai et al.(30) reported that the significant differences regarding d and g stages only occurred between males and females. finally, simonsson et al. (31) showed that males significantly reached stages c, d and e earlier than females. although each study has no gender differences, it has certain differences in one or more developmental stages of the third molar in both genders as in khosronejad et al.(18) and kaomongkolgit and tantanapornkul;(21) there were no statistically significant differences in mineralization stage of third molars between maxilla and mandible. regarding the left and right side symmetry, there was no significant side difference at various developmental stages in both arches like in many studies (13,18,21,29,31), but males in this study showed that their right maxillary molars reached stage c and d significantly earlier than the left one and the right mandibular third molars reached stage e earlier than the left one. this is very prevalent for the third molar to asymmetrically erupted on the left or right side.(10) this agrees with satio(32) who reported that the third molars on the right side of the mouth calcified and erupted earlier when compared with those on the left. the mineralization stages asymmetry of the antimere tooth was found in many studies, as in mincer et al. (26) who found that the symmetry of the third molar formation of both sides in the maxilla was more than in the mandible. also, demisch and wartmann(33) established that the symmetry in the development of the mandibular left and right third molars occurred in about 71% of both sexes, so it is practically a helpful approach in which the dental age could be obtained from left and right side when they are both asymmetrical but scorable.(26) sample size, age, the biological variation of individuals, statistical approach and experience of the observer in age assessment and other factors are attributed to the presence of differences between iraqi sample and that of other studies. the present study was limited by: first, the subjects in this study were randomly selected from two areas in iraq, baghdad and karbala; additionally, those patients were only the patients who referred to the orthodontic clinics . second, ethnicity was not controlled in this study. because of successive wares in iraq, many populations migrated from western and northern iraq to baghdad and karbala, so there is a mix of ethnicity that happened and individuals may be not all pure arabs; they maybe turkman or kurdish subjects. the conclusions that could be drawn from this study were: 1. demirjian's method is an excellent approach for age assessment using opg. 2. all the differences between the present study and other studies in many countries could be due to the difference in the populations chosen from different geographical areas. 3. in this regard, the third molars of males were prior to females in attaining most of demirjian’s stages in both arches. 4. in the mandibular arch, the third molars reached all demirjian's stages earlier than the maxillary arch except in the stages f and g, and subjects will probably be below 18 in both arches at stages a-f while the individuals will be above 18 years at stages g and h. 5. there was no significant gender difference at each given developmental stage of the maxillary and mandibular third molar except stage d in the maxillary arch and stages d and e in the mandibular arch. 6. the third molars are developed symmetrically in both sides (right and left) except the significantly earlier arrival of the maxillary right third molar in some developmental stages than the left one in males. acknowledgment the author would like to thank dr. mohammad nahidh for the invaluable assistance in this study and dr. raoof rasheed and all colleagues for kindly providing part of radiographs used in this study. j bagh college dentistry vol. 32(1), march 2020 radiological age 63 references 1. willems g. a review of the most commonly used dental age estimation techniques. j forensic odontostomatol. 2001; 19: 9-17. 2. schmeling a, olze a, reisinger w, geserick g. der einfluss der ethnie auf die bei strafrechtlichen altersschätzungen untersuchten merkmale rechtsmedizin. 2001; 11: 78–81. 3. baccetti t, franchi l, mcnamara ja. the cervical vertebral maturation (cvm) method for the assessment of optimal treatment timing in dentofacial orthopedics. semin orthod. 2005; 11: 119–29. 4. anderson dl, thompson gw, popovich f. interrelationships of dental maturity, skeletal maturity, height and weight from age 4 to 14 years. growth. 1975; 39: 453–62. 5. demirjian a, goldstein h, tanner jm. a new system of dental age assessment. hum biol. 1973;45:211–27. 6. schmeling a, grundmann c, fuhrmann a. criteria for age estimation in living individuals. int j legal med. 2008; 122: 457-60. 7. gustafson g. altersbestimmungen an zähnen. dtsch zahnärztl. 1955; 10: 1763–8. 8. guo yc, yan cx, lin xw. the influence of impaction to the third molar mineralization in northwestern chinese population. int j legal med. 2014;128:659-65. 9. kullman l. accuracy of two dental and one skeletal age estimation method in swedish adolescents. forensic sci int. 1995;75:255-36. 10. willershausen b, löffler n, schulze r. analysis of 1202 orthopantograms to evaluate the potential of forensic age determination based on third molar developmental stages. eur j med res. 2001; 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9:10715. 24. sisman y, uysal t, yagmur f, ramogl si. thirdmolar development in relation to chronologic age in turkish children and young adults. angle orthod. 2007; 77: 1040-5. 25. hassan na, abo hamila naa. orthopantomography and age determination using third molar mineralization in a sample of egyptains. mansoura j forensic med clin toxicol. 2007; 15: 45-59. 26. mincer hh, hanis ef, berryman he. the abfo study of third molar development and its use as an estimator of chronological age. j forensic sci. 1993; 38: 379-90. 27. narnbiar p. age estimation using third molar development malaysian j patho. 1995; 17: 31-4. 28. priyadharshini ki, idiculla jj, sivapathasundaram b, mohanbabu v, augustine d, patil s. age estimation using development of third molars in south indian population: a radiological study. j int soc prev community dent. 2015; 5: 32-8. 29. darji ja, govekar g, kalele sd, hariyani h. age estimation from third molar development; a radiological study. j indian acad forensic med. 2011; 33: 971-3. 30. rai b, kaur j, anand sc. mandibular third molar development staging to chronologic age and sex in north indian children and young adults. j forensic odontostomatol. 2009; 27; 45-9. 31. simonsson l, näsström k, kullman l. radiographic evaluation of third mandibular molar development as an age indicator in a swedish population. madridge j dent oral surg. 2017; 2: 31-7. 32. satio h. röntgenologische untersuchungen über die entwicklung des dritten molaren. kakubyo-gaekaizasshi1. 2015; 9: 156-71, 366-77, 502-14. 33. demisch a, wartmann p. calcification of the mandibular third molar and its relation to skeletal and chronological age in children. child development. 1956; 27: 459-73. الخالصة الخلفية: تقدير العمر زمنيا هو طريقة عملية في مجال التقصي عن الجريمة اذ يساعد في التعرف عن االشخاص لمعالجتهم سواء كانوا تحت راد العراقيين وتحديد االختالف بين سن البلوغ او بالغين. تهدف هذه الدراسة الى تقييم مراحل تمعدن سن العقل فيما يتعلق بالعمرالزمني لالف الجنسين واالختالف بين الفكين العلوي والسفلي. j bagh college dentistry vol. 32(1), march 2020 radiological age 64 حددت مراحل تطور سن اشعة بانورامية لمرضى تقويم االسنان وفقا لمعايير خاصة وقيمت بصريا. 300 جمعتاالشخاص وطرق العمل: لمراحل تمعدن معينة والتي تم الوصول اليها وفقا للجنسين الزمني قد سجل وفقا العمر لطريقة ديميرجيان. العقل في الفك العلوي والسفلي وفقا فحوصات. لالمزدوجة والعينة الغير معتمدة ل نةقات حددت باستخدام العي ,جوانب الفكين والفكين.الفرو ي تصل اسنان العقل في الفك العلو. العلوي والسفليفروق ذات داللة احصائية بين اسنان العقل في الفكين د ووجالنتائج عدم اظهرت: النتائج بين فروق ذات داللة احصائية بين اسنان العقل في معدالت االعمار . التوجدgو fقبل اسنان العقل في الفك السفلي في المرحلتين مبكرا في eو d في الفك العلوي وفي مرحلتي dة اسنان العقل العلوية والسفلية ماعدا في مرحل ناث في كل مرحلة تطور معطاة في الذكور واال داللة احصائية في اذ هناك فروق ذاتعدا في الفك العلوي للذكور تطور اسنان العقل في الجانبين االيمن وااليسر متشابه ما الفك السفلي. .في الفك السفلي e وللمرحلة cوd المرحلتين كل االختالفات بين الدراسة الحالية االشعة البانورامية. ممتازة في تقدير العمرباستخدامديميرجيان هي طريقة ان طريقة :االستنتاجات . والدراسات االخرى ممكن ان يكون سببها االختالفات في السكان الذين تم اختيارهم من المناطق الجغرافية المختلفة safaa f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 corticotomy assisted pedodontics, orthodontics and preventive dentistry160 corticotomy assisted orthodontic canine retraction safaa s. abed, b.d.s. (1) ali i. al-bustani, b.d.s., m.sc. (2) abstract background: surgical injury to alveolar bone can temporarily accelerate tooth movement by increasing the remodeling rate of alveolar bone. the purpose of this study was to clinically evaluate maxillary canine retraction acceleration with corticotomy-facilitated orthodontics, and its effect on vitality of pulp and gingival sulcus depth. materials and method: the sample consisted of 12 adult patients (4 males, 8 females; mean age, 21.7 years) requiring the therapeutic extraction of the maxillary first premolars, with subsequent retraction of the maxillary canines. surgical holes were done mesially and distally to the side with more space between canine and second premolar, and the other side served as the control. canine retraction was done by power chain applying 200 g of force per side. rate of canine movement and potential molar anchorage loss were measured after one month using study model and acrylic plug. bleeding on probing, radiographical assessment, gingival sulcus depth, and vitality test have also been investigated throughout the study. result: the surgical side showed a statistically higher retraction mean value as compared with the non-surgical side. in other words, the surgical side demonstrated 42.6% greater net canine distalization than the non-surgical side. anchorage loss showed no significant difference between sides. there was no significant difference between the pre and post-surgery gingival sulcus depth and pulp vitality response values of surgical side. conclusion: it has been concluded that surgical holes introduction is effective in accelerating orthodontic tooth movement, and has no harmful effects on surrounding vital structures and/or pulp vitality. key words: canine retraction, corticotomy, tooth movement acceleration. (j bagh coll dentistry 2013; 25(special issue 1):160-166). introduction conventional orthodontic treatment with fixed appliances is likely to last for 20 to 24 months. the duration of orthodontic treatment is one of the major concerns that patients complain about, most-especially the adult patient (1). to shorten the time of orthodontic treatment, various attempts have been made to accelerate orthodontic tooth movement. these attempts mainly direct electrical current (2), micro pulsed electricity (3), electromagnetic field application (4,5), low energy laser (6,7), injection of prostaglandin, sand calcium gluconate (8,9), local injection of vit. d3 (calcitriol) (10,11). the last is oral surgery, including gingival fiberotomy, alveolar surgery and distraction osteogenesis. the effect of gingival fiberotomy is controversial (12). distraction osteogenesis should not be routine in orthodontic treatment, and rapid tooth movement into immature bone regenerating after distraction osteogenesis is not recommended to avoid severe root resorption (13), individual canine retractors are bulky and unavailable on the market, and their long-term effects are unknown (14). surgical injury to alveolar bone can temporarily accelerate tooth movement by increasing the remodeling rate of alveolar bone and decreasing its mineral density, thus decreasing the mechanical resistance of dentoalveolar tissues to orthodontic force. (1)m.sc. student. department of orthodontics. college of dentistry. university of baghdad. (2)assistant professor. department of orthodontics. college of dentistry. university of baghdad. a corticotomy is the procedure by which a flap is elevated and the cortical bone is cut with a bur or piezosurgical instrument approximately 1 -2 mm in depth (16). corticotomies have recently become popularized, which were bone healing mechanisms in combination with orthodontic loadings to decrease treatment times. although this procedure, termed corticotomy-assisted orthodontics (cao) or accelerated osteogenic orthodontics (aoo) was first described in 1893, it has only recently gained wide usage. significantly reduced treatment time has been reported using this procedure with reductions of 75% to 80% of routine treatment time (17). no previous iraqi studies have dealt with this aspect of orthodontics. furthermore, this study will, for the first time, involve surgical holes technique for canine distalization. patients and methods twelve orthodontic patients (4 males, 8 females); with an age ranged from 1728 years and mean age 21.7 years, requiring the therapeutic extraction of the maxillary first premolars, with subsequent retraction of the maxillary canines. the sample was set up to use each patient as his own control, thereby increasing the power of small sample. after the patients prepared for the fixed orthodontic treatment; the study started at second stage of treatment (stage of canine retraction). in this stage of treatment arch wire 0.016*0.022 s.s was placed with stopper and tip back bend just mesial to maxillary first molar, ligation of maxillary anterior teeth from right j bagh college dentistry vol. 25(special issue 1), june 2013 corticotomy assisted pedodontics, orthodontics and preventive dentistry161 lateral incisor to left lateral incisor, ligation of maxillary second premolar and maxillary first molar in each side. peri-apical radiograph was taken for both maxillary canines by using selfprocessing x-ray film; evaluation of periodontium, roots and surrounding bone was done. vitality test was done for each patient for maxillary lateral incisors, canines and second premolars for each side by using electric pulp tester. the pathway for the electric current is thought to be from the probe tip of the test device to the tooth, along the lines of the enamel prisms and dentinal tubules, and through the pulp tissue (18). the circuit was completed via the operator having one gloveless hand that touches the patients’skin (19,20). tingling sensation was felt by patient once increasing the voltage reaching the pain threshold and the reading from device for each tooth was recorded. pocket depth of both canines was measured by inserting graduated probe and identifying the deepest point at each surface of canine (mesial, distal and palatal). the mean of these readings was calculated for each canine (21). impression for each patient was taken then poured by stone. the anterior palatal vault could be used as a stable reference point (22). an acrylic plug was fabricated from acrylic with stainless steel reference wires (1.0mm) embedded in the acrylic and extended to the cusp tips of canines and to the central fossae of first molars (23).the patient was re-instructed to maintain good oral hygiene, showing them a video about the procedure of brushing with orthodontic appliance, and prescribing a mouth wash (2% chlorhexidine). surgery and retraction the surgery was done on the side of canine which needed more distalization i.e. the canine in more class ii relation or the side having more space between canine and second premolar. local anesthesia infiltration was injected in buccal vestibule from lateral incisor to second premolar at side of surgery and palatally, when the area got anesthetized (examined by probe) incision was made and two sided gingival mucoperiosteal flap was raised to expose cortical bone on the buccal side of the canine (special care was taken not to perforate the flaps, and any interdental papillary tissue that remained inter proximally left in place, the flap retracted beyond the apices of teeth as much as possible). a series of circular holes (3 to 4 holes, the number of holes was determined according to the length of canine root) were made along the bone mesially and distally adjacent to canine, these holes were made with a 1.5 mm round bur spaced approximately 2mm apart, under normal saline solution irrigation and depth of each hole was carefully determined to reach the medullary bone by putting stopper on bur at (3mm), the bleeding through the holes was confirmed by probe, the flap was returned to its position carefully and sutured with 3/0 non absorbable silk braded suture fig.(1), fig.(2). antibiotic (amoxicillin capsules, 500 mg 3 times daily) was prescribed for patients with analgesic (paracetamol tablet, 500 mg 2 on need). none of the patients was allergic to penicillin excepting one patient who was given erythromycin (250 mg 4 times daily) instead. force was applied for both sides by elastomeric chain to retract canine at time of surgery with 200 g (24) measured by force gauge. fig.1 fig.2 monitoring visits the patients came after one week of surgery date to remove suture and examine the area of surgery for any inflammation or complication. every patient was instructed to come in regular visits with intervals of one week for: 1. checking gingival health by using (gingival sulcus bleeding index) scoring system (21,25). bleeding after probing to the base of the probable gingival sulcus has been a common way of assessing j bagh college dentistry vol. 25(special issue 1), june 2013 corticotomy assisted pedodontics, orthodontics and preventive dentistry162 presence of sub gingival inflammation (25). in this system registration, "1" is scored in case bleeding emerges within 15 seconds after probing while absence of bleeding scored (0). 2. checking any interference of maxillary canines with opposing teeth in the line of tooth movement. if this interference was present, trimming from palatal surface of maxillary canine was done. 3. reloading surgical and non-surgical side with 200g by elastomeric chain, the force was measured by force gauge as mentioned previously. one month postsurgical in this visit the following steps were done in the same way mentioned previously: p.a radiograph for maxillary canines, vitality test for lateral incisors, canines and second premolars, gingival sulcus depth measurement for maxillary canines and impression for maxillary arch. canine movement and anchorage loss measurements a reference point was determined on each canine(on cusp tip) of the first model and transmitted on the canines of the final model (fig. 3), the acrylic plug that fabricated on first model then transmitted to the final model to measure the distance between reference wire and the reference point on canine as shown in fig. (4), this distance represented the net canine movement per month. the anchorage loss was measured by determining reference point on first molar (usually in the central fossa) of first model and also transmitting it to second model then the acrylic plug that fabricated on first model was transferred to final one with measuring the distance between projecting (reference) wire and reference point which represented the net anchorage loss per month (23,26,27). fig.3 fig.4 statistical analysis all data were statistically evaluated using the statistical package for social sciences (spss) computer program. the statistical analyses included: descriptive statistics (means, standard deviations, minimum and maximum values, graphical presentation by bar-charts) and inferential statistics using (wilcoxon signed-rank test and chi square test). values of p < 0.05 evaluated as statistically significant. results canine movement and anchorage loss the surgical side showed a higher mean value as compared with the non-surgical side which was statistically highly significant according to the wilcoxon signed rank test. in other words, the surgical side demonstrated 42.6% greater net canine distalization than the non-surgical side as shown in table (1). mean of anchorage loss is 0.05mm per month in both sides, i.e. nonsignificant difference between sides as shown in table (2). radiographic assessment all the peri-apical radiographs showed almost similar normal sequence of orthodontic tooth movement for both the surgical and non-surgical sides. the periodontal ligament of retracted canines showed compression at the pressure (distalization) site, while widening at the tension (mesial) site. fig (5) show radiographs patient for both canines pre-surgery and post-surgery. surgical side cannot be differentiated from non surgical side in respect of appearance of surgical holes and/or bone destruction. j bagh college dentistry vol. 25(special issue 1), june 2013 corticotomy assisted pedodontics, orthodontics and preventive dentistry163 fig.5 gingival sulcus depth a comparison between the pre and postsurgery gingival sulcus depth values of surgical side, the measurements did not exceed 2.5 mm pre and post – surgery. according to wilcoxon signed rank test there is no significant change in the depth shown in table (3). pulp vitality test in a comparison between preand post-surgery pulp vitality test in surgical side and a according to chi square test there is no significant change in pulp vitality response of the teeth on surgical side between preand post-surgery testing as shown in table (4). clinical complications and side effects all patients did not manifest any serious complication after surgery, four patients had postoperative swelling lasted for one to two days after the surgery. there was no sign of gingival inflammation according to bleeding in probing index during the monitoring visits. discussion corticotomy assisted orthodontics has been reported in few clinical cases (28). the procedure enhances orthodontic tooth movement by accelerating bone metabolism due to controlled surgical damage. it was initially based more on techniques used ostectomy instead of approaches of corticotomy. it is considered an intermediate therapy between orthognathic surgery and conventional orthodontics (29). surgical intervention or osteoporotic situation that is favorable for rapid orthodontic tooth movement can be induced within the alveolar bone without increasing the risk of root resorption (17) and localized osteoporosis (30-33). surgery invokes rap in both hard and soft tissue and reorganization is potentiated, leading to a transient catabolic condition. for bone, this transient osteoporosis means increased mobilization of calcium, decreased bone density, and increased bone turnover, all of which would facilitate more rapid tooth movement. osteoporosis provided a favorable environment for increasing the rate of tooth movement without increasing the risk of root resorption in rats (34). moreover, it has been demonstrated that the residual soft tissue matrix has the ability to induce remineralization after the cessation of tooth movement (35). all of this suggests that the dynamics of the accelerated tooth movement in this study might be more appropriately described as a demineralization/ remineralization process, rather than bony block movement or resorption/ apposition. this perspective is substantiated by the fact that there is a growth protein component in the soft tissue matrix of bone (36-38). following cessation of the active tooth movement, this growth protein component may assist in stimulating an increase in osteoblastic activity, resulting in remineralization of the soft tissue matrix (17). gingival bleeding on probing index was used in this study. this index, unlike other indices which give an assessment for a quadrant or the whole dentition, can assess the gingival inflammation for a specific tooth or a specific site. when assessing gingival health of canines in both sides, all involved teeth scored (0), indicating successful prevention of maxillary canine's gingival inflammation throughout the study period due to the firm instructions about the proper oral hygiene maintenance methods given to the patients throughout the study, in addition to the use of mouth rinses and special orthodontic brushes. in this study, the response of teeth was increased gradually from lateral incisor, canine to second premolars. key variables known to affect the response to pulp testing are the thickness of the enamel and dentine, the number of nerve fibers in the underlying pulp, and the direction of the dentinal tubules is also important in establishing pulp test responses in various parts of the tooth crown. the dentinal tubules run an almost straight course from the incisal edge of anterior teeth to the pulp horn. in multi-cuspal teeth, the course of tubules is somewhat curved and resembles an ‘s’ shape (55). because it is principally the fluid in the tubules that conducts electrical impulses from the pulp tester electrode to the pulp, the shorter the distance between the electrode and the pulp, responds faster and records lower score. furthermore, orthodontic force increases the response threshold to electric pulp test. the effect j bagh college dentistry vol. 25(special issue 1), june 2013 corticotomy assisted pedodontics, orthodontics and preventive dentistry164 is almost instantaneous and could persist for up to 9month after treatment (39,40), this may give another explanation for the result of teeth responding at different levels of current intensity in this study, and this is in agreement with (41-44). statistically, ept readings regarding the three teeth did not differ significantly between the two sides both pre and post-surgery and between per and post-surgery for surgical side. this is attributed to the safe, nontraumatic surgical intervention for the canine and surrounding area, and the use of optimal physiologic force that did not endanger pulp vitality. as a conclusion; the introduction of surgical holes is effective in accelerating otm and shortening orthodontic treatment time, enhancement of bone turnover through demineralization/remineralization concept can serve as a successful clinical adjunct to the bone resorption /deposition concept and when done properly, surgical holes introduction produce no iatrogenic insult on periodontium and/or pulp vitality. table 1: descriptive and inferential statistics of net canines' movement side descriptive statistics side difference n mean s.d. min. max. wilcoxon signed ranks test p-value sig. non-surgical side 12 1.22 0.40 0.55 1.82 -3.06 0.002 hs surgical side 12 1.74 0.47 1 2.34 table 2: descriptive and inferential statistics of anchorage loss side descriptive statistics side difference n mean s.d. min. max. wilcoxon signed ranks test p-value sig. non-surgical side 12 0.05 0.12 0 0.3 0 1 ns surgical side 12 0.05 0.12 0 0.3 table 3: comparison the preand postgingival sulcus depth in the surgical side sulcus depth descriptive statistics sulcus depth difference n mean s.d. min. max. wilcoxon signed ranks test p-value sig. pre-gingival sulcus depth 12 1.98 0.22 1.5 2.5 -1.34 0.18 ns post-gingival sulcus depth 12 1.94 0.26 1.5 2.5 table 4: comparison pre-surgery and post-surgery vitality test in surgical side scores lateral incisor canine 2 nd premolar pre-vitality post-vitality pre-vitality post-vitality pre-vitality post-vitality 1 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 2 3 (12.5%) 4 (16.7%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 3 3 (12.5%) 2 (8.3%) 2 (8.3%) 2 (8.3%) 0 (0%) 0 (0%) 4 4 (16.7%) 4 (16.7%) 1 (4.2%) 1 (4.2%) 0 (0%) 0 (0%) 5 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 6 2 (8.3%) 2 (8.3%) 5 (20.8%) 6 (25%) 4 (28.6%) 4 (28.6%) 7 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 8 0 (0%) 0 (0%) 4 (16.7%) 3 (12.5%) 2 (14.3%) 2 (14.3%) 9 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 10 0 (0%) 0 (0%) 0 (0%) 0 (0%) 1 (7.1%) 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(ivsl). 42. bender i b, landau m a, fonsecca s, trowbridge h o. the optimum placement-site of electrode in electrical pulp testing of the 12 anterior teeth. j am dent assoc 1989; 118: 305–310. 43. hall cj, freer tj. the effects of early orthodontic force application on pulp test responses. austr dent j 1998; 43: 359–361. 44. veberiene r, smailiene d, baseviciene n,toleikis a, machiulskiene v. change in dental pulp parameters in response to different modes of orthodontic force application. angle orthod 2010; 80: 1018-22. (ivsl). sarmad.doc j bagh college dentistry vol. 27(2), june 2015 assessment of cortisol oral diagnosis 86 assessment of cortisol as salivary psychological stress marker in relation to temporomandibular disorders among a sample of dental students sarmad qays ali, b.d.s. (1) raja hadi, b.d.s., m.sc., ph.d. (2) abstarct background: university dental students perceived a higher level of stress prior to the final exam associated with raised salivary cortisol levels which could be considered as a useful noninvasive biomarker for measuring acute stress. using a helkimo anamnestic and clinical dysfunction scoring for temporomandibular disorders can give a better insight about the association of this marker and temporomandibular joint disorders. the aim of this study was to evaluation level of salivary cortisol in stressor students with temporomandibular disorder and the relation between this marker in relation to temporomandibular disorder severity. this might give a better understanding to the role of psychological stress as an etiological factor for developing temporomandibular joint problems. materials and methods: a total eighty participants age between 20 to 24 were recruited for this study. the participants were university dental students under graduate students at final examination period who were examined and gave saliva samples in final examination period. salivary assay kits as cortisol was used to measure those variables and a helkimo anamnestic and clinical dysfunction scoring for tmd. results: the group of participants with stress and temporomandibular disorder showed significantly higher levels of salivary cortisol than the control group, the salivary cortisol has statistically significant correlation with helkimo anamnestic categories (di-i mild, di-ii moderate and di-iii severe. salivary cortisol levels show significant but weak association with two categories of clinical dysfunction criteria in helkimo index system, which are muscle pain and tmj pain on palpation. conclusion: this study demonstrated that university students perceived a high level of stress before the final examination. salivary cortisol is the stress biomarker that is most often used to measure acute stress. helkimo anamnestic and clinical dysfunction scoring criteria for still the pioneer for measuring a temporomandibular disorder. keywords: stress, cortisol, helkimo, temporomandibular joint tmj, temporomandibular disorder tmd. (j bagh coll dentistry 2015; 27(2):86-92). introduction university students are liable to a higher level of stress especially in pre-examination period, if stress is prolonged, the stress response has two principal facets: the neuro-endocrine, which involves corticotropin-release hormone, activation of the hypothalamic-pituitary-adrenal axis and the secretion of cortisol into circulation. cortisol is then filtered through the acinar cell membrane of the salivary glands, and is found in saliva in the free unbound form. secondly, the stress response involves activation of the autonomic nervous system, release of catecholamines (e.g., plasma norepinephrine, pne), and sympatho-mimetic manifestations, such as increase salivation, and increase secretion of sα-amylase (1). salivary cortisol levels increase under a variety of physical (i.e., exercise, heat and cold) and psychological (i.e., written examinations) challenges. salivary and plasma cortisol levels always correlate with each other following stress, confirming that the two pathways are the same salivary cortisol increases with psychological stress and correlates serum cortisol (2). (1) master student. , department of oral diagnosis, college of dentistry, baghdad university (2) professor, department of oral diagnosis, college of dentistry, baghdad university temporomandibular joint dysfunction is an collective term covering pain and dysfunction of the muscles of mastication and the temporomandibular joints. the most important feature is pain, .followed by restricted mandibular movement and noises from the temporomandibular joints (tmj) during jaw movement (3). although temporomandibular disorder tmd is not life threatening, it can be detrimental to quality of life (4) because the symptoms can become chronic and difficult to manage. usually people affected by tmd are between 20 and 40 years of age, and it is more common in females than males (5). the etiology of tmds is multifactorial which is thought to be caused by multiple, poorly understood factors (6). but the exact etiology is unknown (7). there are factors which appear to predispose to tmd (genetic, hormonal, anatomical), factors which may precipitate it (trauma, occlusal changes, parafunction), and also factors which may prolong it (stress and again parafunction) (8). overall, 2 hypotheses have dominated research into the causes of tmd, namely a psychosocial model and a theory of occlusal disharmony (7). oral habits or parafunctions, defined as any oral nonfunctional activity or behaviour involving j bagh college dentistry vol. 27(2), june 2015 assessment of cortisol oral diagnosis 87 the masticatory system, are neither uncommon nor are they always harmful (9). it is only when such activities exceed an individual’s physiologic tolerance that breakdown of the masticatory system may occur. in such cases the initial breakdown takes place in the tissue with the lowest structural tolerance in that particular individual, e.g. joints, teeth or muscles (10). oral habits or parafunctions have been reported to be common worldwide, with many students and adolescents performing them on a daily basis (11). oral habits include a variety of activities, such as continuous gum chewing, nail biting, and chewing on writing implements (pencils, pens). oral habits such as these are common among students, and they were shown to have a potentially detrimental effect on the masticatory system (12,13). saliva has been described as the mirror of the body. the wide spectrum of compounds present in saliva may provide information for clinical diagnostic applications. saliva is a good medium because its collection is noninvasive and the donation process is relatively stress free, so that multiple collections can be performed without imposing too much discomfort on the donor (14). cortisol, known more formally as hydrocortisone is a steroid hormone, more specifically a glucocorticoid, produced by the zona fasciculata of the adrenal cortex (15). it is released in response to stress and a low level of blood glucocorticoids. its primary functions are to increase blood sugar through gluconeogenesis; suppress the immune system; and aid in fat, protein and carbohydrate metabolism. it also decreases bone formation (16). in the blood only 1 to 15% of cortisol is in its unbound or biologically active form. the remaining cortisol is bound to serum proteins (17). unbound serum cortisol enters the saliva via intracellular mechanisms, and in saliva the majority of cortisol remains unbound to protein, because of partial conversion of cortisol to cortisone during passage through the salivary glands, the absolute level of free cortisol in saliva is 10% to 35% lower than it is in blood (18). salivary cortisol levels are unaffected by salivary flow rate or salivary enzymes (19). subjects, materials and methods the subjects: a total eighty participants age between 20 to 24 were recruited for this study. the participants were university dental students under graduate students at final examination period who were examined and gave saliva samples in final examination period. the participants in this study divided into two groups: -case group: sixty stressed students with temporomandibular disorders (tmd). -control group: twenty students without stress and temporomandibular disorders (tmd). *inclusion criteria 1. university dental students (20-24) years old from both genders with stress and temporomandibular disorders were included in the case group. the female students were in the luteal phase of menstrual cycle to be equal to male in the activity of hypothalamuspituitary-adrenal axis. 2. university dental students (18-30) years old from both genders without stress and temporomandibular disorders were included in the control group. * exclusion criteria students with a history of use of corticosteroids in the past year, a history of antidepressant medication or head injury, on hormone supplements including oral contraceptives at the time of saliva collection., orthodontic treatment, occlusal disharmonies like cross bite and premature contact or dental pain. those with muscle tenderness due to systemic diseases as fibromyalgia, neuralgia and local infection and cases with more than 2 missing posterior teeth. materials: high sensitivity, salivary cortisol enzyme immunoassay kits (uscn life science inc. wuhan, china). methods of examination: the participants examined according to helkimo anamnestic and clinical dysfunction index of temporomandibular disorders which consists of standardized series of diagnostic tests based on clinical signs and symptoms. statistical analysis statistical analysis was computer aided. an expert statistical advice was sought for. statistical analyses were done using ibmspss version 21 computer software (statistical package for social sciences). data were presented in measures of mean, standard deviations, range (minimummaximum values), median, frequency and percentages. the significance in difference between the means (quantitative data) for two groups was tested using independent student ttest, while using analysis of variance (anova) for more than two groups the receiver operating j bagh college dentistry vol. 27(2), june 2015 assessment of cortisol oral diagnosis 88 characteristics (roc) and predictive value (pv) was used in this study. the correlation coefficient value (r) either positive (direct correlation) or negative (inverse correlation) with value <0.3 represent no correlation, 0.3-<0.5 represent weak correlation, 0.5-<0.7 moderate strength, >0.7 strong correlation. probability test (p value) was considered statistically significant when the p value < 0.05 and regarded as highly statistically significant when the p value < 0.001. results the data related to salivary cortisol levels showed normal distribution in both case and control groups. the group of participants with stress and tmd showed significantly higher levels of salivary cortisol (mean 177.8 ± se 12.24 ng/ml) than the control group (mean 22.9 ± se 2.28 ng/ml). see table 1 and figure 2. table 1: the salivary cortisol levels in the case and control groups. p study groups salivary cortisol cases with stress controls <0.001 (9.6 to 413) (9.8 to 46) range 177.8 22.9 mean 94.8 9.9 sd 12.24 2.28 se 60 20 n figure 2: dot diagram with error bar chart demonstrates the comparison of salivary cortisol levels in both control and stress with tmd groups. bars represent the median while range lines represent the 95% confidence interval ci (measurements in ng/ml and p value< 0.001). the predictive value measurements for salivary cortisol showed highly positive predictive value (ppv) at 50% and 90% levels with the cutoff point of 70.1 ng/ml. above this point, the salivary cortisol can be used as biomarker for accurate prediction of stress and tmd (accuracy 93.7%). correlation analysis of salivary cortisol with helkimo anamnestic clinical dysfunction score shows positive association expressed by significant p value of 0.026. this means that the salivary cortisol has statistically significant correlation with helkimo anamnestic categories (di-i mild, di-ii moderate and di-iii severe). see table 2 and figure 3. table 2: association of salivary cortisol levels with helkimo anamnestic categories of tmd p study groups salivary cortisol (10–25) di-iii (severe dysfunction) (5–9) di-ii (moderate dysfunction) (1–4) di-i (mild dysfunction) <0.001 (185 to 364) (105 to 413) (9.6 to 410) range 264.7 221.9 158.8 mean 91.1 117.6 81.3 sd 52.6 32.63 12.26 se 3 13 44 n fig 3: dot diagram with error bar chart demonstrating the association of salivary cortisol levels with helkimo anamnestic categories of tmd. bars represent mean of the salivary cortisol in each category, range lines represent standard errors and p value <0.05. in depth analysis with each single criteria used by helkimo, revealed more interesting results. salivary cortisol levels show significant but weak association with two categories of clinical dysfunction criteria in helkimo index system, which are muscle pain and tmj pain on palpation. the muscle of mastication with highest tenderness to palpation was master muscle followed by temporalis and lateral pterygoid with less tenderness. see table 3. the distribution percentage of varying oral habits in tmd students that shown as follow (see table 4). j bagh college dentistry vol. 27(2), june 2015 assessment of cortisol oral diagnosis 89 table 3: association of salivary cortisol levels with individual clinical criteria used in helkimo index for tmj dysfunction salivary cortisol range mean sd se n p gender female (9.6 to 410) 191.1 94.2 17.19 30 0.28[ns] male (11.2 to 413) 164.5 95.2 17.39 30 mandibular mobility (opening, laterotrusive, protrusive) 0.027 normal range of movement (9.6 to 394) 158.7 82.8 13.09 40 slightly impaired mobility (105 to 413) 215.9 107.5 24.05 20 severely impaired mobility ** ** ** ** 0 r=0.202 p=0.12[ns] symptom: impaired tmj function 0.01 smooth movement without tmj sounds and deviation on opening or closing movement <2 mm (104.4 to 410) 219.2 85.9 21.47 16 sounds in 1 or both joints and/or deviation >2 mm on opening or closing movements (9.6 to 413) 156 90.2 13.92 42 locking/and/or luxation of the tmj (245 to 364) 304.5 84.1 59.5 2 r=-0.191 p=0.14[ns] symptoms: masseter pain 0.007 no tenderness to palpation in masticatory muscles (9.6 to 212.2) 114.7 75.8 26.78 8 tenderness to palpation in 1-3 palpation sites (11.2 to 413) 177.6 89.8 13.11 47 tenderness to palpation in > 4 palpation sites (185 to 394) 280.6 92.9 41.55 5 r=0.373 p=0.003 symptoms: tmj pain 0.045 no tenderness to palpation (9.6 to 410) 154.5 96.3 17.89 29 tenderness to palpation laterally (16.4 to 413) 199.5 89.5 16.08 31 tenderness to palpation posteriorly ** ** ** ** 0 r=0.286 p=0.027 symptom: pain on movement of the mandible 0.09[ns] no pain on movement (9.6 to 240) 162.9 68.1 14.53 22 pain on 1 movement (11.5 to 413) 174.5 103.4 18 33 pain on > 2 movements (139 to 390) 264.6 109.7 49.04 5 r=0.101 p=0.44[ns] table 4: the distribution percentage of varying oral habits in tmd students. % n oral habits 20.0 12 non 28.3 17 clenching 8.3 5 grinding 6.7 4 biting nail 21.7 13 bruxism 15.0 9 chewing 100.0 60 total discussion for decades, research on the acute and chronic effects of stress has employed cortisol levels as an index of the individual response to stress (20). salivary cortisol levels provide an accurate, reliable, and non-invasive measure of stress in both adults and children (21). which match the j bagh college dentistry vol. 27(2), june 2015 assessment of cortisol oral diagnosis 90 result of this study that showed salivary cortisol is useful biomarker for assess psychological stress. cortisol is a hormone secreted by the hypothalamus pituitary adrenal axis (hpaa) and has been used as an accurate biomarker in stress research for over half a century (22). in dentistry salivary cortisol has been used to measure the role of stress in a variety of settings from the anxiety of dental treatment to periodontal disease, dental caries and temporomandibular disorders (23-26). as already known, cortisol secretion increases significantly in the state of acute stress as in psychological stressor of written examinations (20, 27, 28). these results have an agreement with this study that have found a highly significant levels of salivary cortisol which in turn strongly support these previous studies that have showed and suggested the use of cortisol as non-invasive indicator for assessment stress with tmd. in 2004, dickerson and kemeny had found that the peak cortisol response occurs between 21 and 30 minutes from the onset of the examination, and that it does not depend on the duration of the examination (27). salivary cortisol levels increase several fold within a short time period after the onset of psychological stress (29), and those results have an agreement with this study while disagree with (30-34), which showed that the results related to written examinations (tests) were heterogeneous and not necessarily accompanied by cortisol increase. the predictive value measurements for salivary cortisol showed highly positive predictive value (ppv) at 50% and 90% levels with the cutoff point of 70.1 ng/ml. above this point, the salivary cortisol can be used as biomarker for accurate prediction of stress and tmd (accuracy 93.7%). temporomandibular joint disorder (tmd) represents a common health problem (35). it is an umbrella term embracing a number of clinical manifestations that involve the temporomandibular joint (tmj), the masticatory muscles and the teeth. patients with tmd usually suffer from muscle and/or joint pain on palpation and on mandibular movements, joint sounds and the mandibular range of motion may be limited (36). tmd can affect any patients regardless of age including children (37). or gender with varying signs and symptoms (38). these investigations are in agreement with the result of this study that have found there is no significant difference between age and gender groups for both case groups (stress with tmd) and control without tmd problems, statistical analysis showed the association of salivary cortisol with the clinical criteria of tmj that involve pain of soft tissue (muscles and tmj ligaments), while the other clinical criteria (impaired mobility, impaired tmj function and painful movement of mandible) did not show any associated with salivary cortisol. this indicate that acute stress causing higher level of cortisol which have greater impact on the early clinical criteria such as muscle pain and tmj pain and the other criteria that have established mobility impairment may not related to acute stress thus show no association. these other criteria may be related to chronic stress rather than acute type. tmds can be subdivided into muscular and articular categories. differentiation between the two is sometimes difficult because muscle disorders may mimic articular disorders, and they may coexist (39). in the present study it was used helkimo anamnestic and clinical dysfunction index as a scoring for tmd students and the results that the muscles have pain on palpation as following: masseter muscles (40%), temporalis (31%), lateral pterygoid (9%), medial pterygoid (6%), anterior diagastric (4%) and sternocleidomastoid (2%), while the students with no symptoms of myofascial pain (8%). parafunctional habits of masticatory muscles, with and without associated chronic pain. in this study the distribution percentage of varying oral habits in tmd students that shown as follow: clenching (28.3%), bruxism (21.7%),chewing: lip, gum, pen, cheek (15%), grinding (8.3%), bitting nail (6.7%), while those have no parafunctions habits was (20%). it is believed that habits can act as an important etiologic factor of tmd, as they lead to a traumatic dental occlusion that may affect the teeth and the masticatory muscles and temporomandibular joints, causing the disruption of the functional balance stomatognathic system, or worsening the already installed tmd 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.التوتر لقیاس حیوي كمؤشر اللعابي الكورتیزول ھرمون اعتبرت دراسات دةع ھنالك .الجامعة طلبة عند الحاد التوتر لقیاس تداخلي الوظیفي الصدغي المفصل واختالل الحیوي المؤشر ھذا بین العالقة عن جید تصور یعطي ان ممكن الصدغي للمفصل السریري الوظیفي االختالل مدى لتسجیل .السریري وھذا .الوظیفي الصدغي المفصل اختالل من یعانون واللذین للتوتر تعرضھم عند الجامعة طلبة عند اللعابي الكورتیزول ھرمون مستوى متقیی ھو :الدراسة اھداف .الصدغي لمفصل السریري الوظیفي الختالل مسبب كعامل النفسي التوتر لدور افضل فھم یعطینا ربما الى عشرین بین اعمارھم تتراوح اللذین بغداد جامعة االسنان طب كلیة طلبة من ثمانین من متكونة مجموعة على الدراسة ھذه انجاز تم : العمل وطریقة المواد سریریا فكانوا البقیة العشرون أما .الدراسة كمجموعة اختیروا الصدغي المفصل في سریري وظیفي اختالل من یعانون طالبا ستون منھم كان .عاما وعشرین اربعة واختالل اضطرابات وتشخیص البحث لمعاییر وفقا المشاركین فحص تم وقد .المراقبة كمجموعة اختیروا واللذین الصدغي المفصل في ظیفيو اختالل اي بدون .اللعابیین والكورتیزول االمیلیز تركیز لقیاس النھائي االمتحان قبل المحفز الغیر اللعاب عینات من لترات ملي خمسة جمع تم .ھلكیمو نظام حسب الصدغي المفصل .فیالدراسة للمشاركین الصدغي للمفصل الوظیفي االختالل و الكورتیزول ھرمون مستوى بین طردیة عالقة النتائج اظھرت لقد : النتائج السریري الوظیفي ختاللباال وعالقتھ الجامعة طلبة عند النفسي التوتر لقیاس حیوي كمؤشر الكورتیزول ھرمون استخدام امكانیة الدراسة ھذه من نستنتج : استنتاج .الصدغي للمفصل journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 51 review article force degradation of orthodontic elastomeric chains: a literature review ali rahman issa1* , ammar salim kadhum2 1 master student, department of orthodontics, college of dentistry, university of baghdad, iraq. 2 assistant professor, department of orthodontics, college of dentistry, university of baghdad, iraq *correspondence email: ali.hassan1902@codental.uobaghdad.edu.iq abstract: background: elastomeric chains are used to generate force in many orthodontic procedures, but this force decays over time, which could affect tooth movement. this study aimed to study the force degradation of elastomeric chains. data and sources: an electronic search on cochrane central register of controlled trials (central), medline, lilacs, and pubmed was made, only articles written in english were included, up to january 2022.study selection: fifty original articles, systematic reviews, and rcts were selected. conclusion: tooth movement, salivary enzymes, alcohol-containing mouthwash, whitening mouthwash, and alkaline and strong acidic (ph <5.4) solutions all have a significant impact on elastomeric chain force degradation. the force level of elastomeric chains degrades rapidly over time; however, the force degradation rate is slower in thermoset chains than in thermoplastic ones. an efficient tooth movement could be achieved by using a thermoset chain type with monthly replacement. ethylene oxide and gamma sterilization methods are preferred to avoid the risk of cytotoxicity. keywords: orthodontic, elastomeric chain, force degradation, tooth movement. introduction elastomeric chains are polyurethane-based polymers synthesized through chemical reactions between polyether or polyester with bi-functional iso-cyanates (1). they have been introduced in orthodontic treatment since the 1960s. a variety of forms is available depending on the distance between the rings. since they are reasonably hygienic, affordable, simple to use, and don't require patient cooperation, they are widely used (2). however, there are some disadvantages to consider including the time-limited mechanical efficiency which necessitates their regular replacement. this efficiency is affected by both internal and external influences, which determine their permanent deformation. material composition, production methods, and physical morphology are all internal influences, while temperature, ph, and moisture absorption are external influences (3). this review investigated the effects of the internal and external influences on force degradation in orthodontic elastomeric chains. effect of time several authors (4-16) showed that the tested elastomeric chains were incapable of generating continuous force over time. according to their research, the greatest amount of force degradation (20 50% depending on the study and chain type) happened on day one (particularly the first hour), followed by a considerably slower rate of degradation over the next four weeks, providing an average degradation of 50 to 85% (5,7,9-16). andreasen and bishara (4) advocated additional chain extension to produce a higher initial force to compensate for this rapid force degradation. however, this led to enormous patient discomfort and could lead to complications like root resorption (17). received date: 12-03-2022 accepted date: 03-04-2022 published date: 15-12-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org /licenses/by/4.0/). https://doi.org/10.26477/jbcd. v34i4.3276 mailto:ali.hassan1902@codental.uobaghdad.edu.iq https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3214 https://doi.org/10.26477/jbcd.v34i3.3214 j. bagh. coll. dent. vol. 34, no. 4. 2022 issa and kadhum 52 hershey and reynolds (5) increased the study time to six weeks and included simulated tooth motions at a rate of 0.25 and 0.5 mm per week. after four weeks, all modules sustained an average of 40% of their initial force, and a similar level after six weeks was recorded. the rate of force loss increased as the teeth were moved about in a virtual environment. only 33% of the initial force persisted after four weeks at a rate of 0.25 mm, while 25% remained at a rate of 0.5 mm over the same period. more recently, evans et al. (18) have published a clinical trial that tested elastomeric chain (3m) ability to produce sufficient force for orthodontic tooth movement over 16 weeks. this study had a split-mouth design, with the chain being removed after four weeks on one side but kept in for the entire 16 weeks on the other side. they found a difference in the rate of space closure between the altered and unaltered sides which was insignificant statistically. clinically the chains were capable of moving teeth after 16 weeks although the generated force was 86 gm (the minimum suggested force level is 100 gm). effect of internal factors the method of manufacturing may affect the mechanical properties of the material. hershey and reynolds (5), in an in vitro setting, found that die-cut stamped elastomers maintained higher levels of force than the injection-molded ones. however, clinical findings in canine retraction for both types were similar with no statistically significant difference (2,8). different elastomeric chain configurations are available depending on the distance between the rings in their passive state. generally, the continuous chains were reported to deliver greater initial force and less deterioration than the chains with a longer distance between the rings (19). the amount of force generated by the elastomeric chain varies from one brand to another. rock et al. (20) found that the initial force generated by different brands of closed elastomeric chains stretched to 100% was 403 to 625 gm. they considered this a high amount of force and recommended extending the elastomeric chain to only 50-75% of its original length (regardless of the number of links) to achieve the desired force of approximately 300 gm. aldrees et al. (12) studied 19 clear elastomeric chains with different varieties (closed, short, and long) from eight manufacturers (ormco/sybron, 3m/unitek, dentaurum, dentsply/gac, ortho-organizers, american orthodontics, rocky mountain orthodontics, and tp orthodontics) and found significant differences in the mean percentage of force degradation between them. in light of these variations, a cautious practitioner should use a force gauge to define the needed initial force level compatible for efficient tooth movement. in 1985, killiany and duplessis (7) conducted a study about the new elastomeric chain (energy chain) from rocky mountain orthodontics and compared it to the conventional elastomeric chain (thermoplastic) from american orthodontics. at the time, it was not known that the rocky mountain elastomeric chain was a thermoset type. force degradation testing revealed that the american orthodontics plastic chain initially applied 375 gm of force, whereas the rocky mountain orthodontics chain produced 330 gm of force. after four weeks, the rocky mountain orthodontics chain retained 65.8% of its initial force, while the american orthodontics chain retained 33.4% only. in an in-situ stetting, baratieri et al. (21) discovered that only thermoset type maintained force levels over 100 gm after three weeks. masoud et al. (22) investigated two types of elastomeric chains (thermoset and thermoplastic). they tested one of each type from american orthodontics and ormco. they came to the conclusion that thermoset chains generated lower initial force and degraded at a much slower rate than thermoplastic chains, prompting them to recommend that a clear distinction should be made between the two during application. additionally, subroto et al. (23) found that the thermoset elastomeric chain color stability is superior to the thermoplastic type. thermoset elastomeric chains are marketed under various brand names that imply memory or low force decay (14). these elastics have grown in favor of other materials in recent years as a result of j. bagh. coll. dent. vol. 34, no. 4. 2022 issa and kadhum 53 manufacturer claims regarding their "memory," a reduced force deterioration with time, a lighter initial force, and ease of usage; and being compliance-free, smooth, and more affordable than niti springs (24). khanemasjedi et al. (25) reported that by using a thermoset elastomeric chain and replacing it every month, the canine can be retracted at speeds comparable to those achieved with a niti coil spring. however, thermoset chains needed more stretching than thermoplastic chains to achieve the desired forces (12). cheng et al. (3) attempted to enhance the physical properties of elastomeric chains by nanoimprinting their surface during manufacturing. nanopillars are nanostructures created on the surface of elastomeric chains as a part of the treatment. the results were promising, as this procedure transformed them from hydrophilic to hydrophobic, reducing the problems associated with these force-generating auxiliaries. the effect of external factors (environmental factors) david et al. (6) evaluated the effects of thermo-cycling on the force degradation pattern. they found that the thermo-cycled group (15-45°c) had significantly lower force degradation than the group maintained at a constant temperature of 37°c. however, this difference was reported as only 7-10 gm after three weeks of elastomeric chain stretching. sulaiman et al. (26) tested the effect of temperature on the elastomeric chain by immersing them in artificial saliva at different temperatures (4°c, 23°c, 37°c, 55°c) for 210 minutes. the force degradation of the elastomeric chain stored at 23°c was statistically significantly higher, while other groups have a similar value of force degradation (no statistically significant difference). there is a controversy in literature when evaluating the effects of artificial saliva on force degradation versus water. von fraunhofer et al. (27) found that elastomeric chains in artificial saliva needed more stretching to achieve the desired force, while other researchers (4,19) reported no statistically significant difference between the two. however, the condition is different in the oral cavity as enzymes (especially esterase) in saliva can contribute to polyurethane degradation (28). andhare et al. (29) reported higher force degradation in vivo studies than in vitro studies in a systematic review and meta-analysis. ramazanzadeh (30), javanmardi and salehi (31), and mirhashemi et al. (14) investigated the effects of fluoride on elastomeric chains. they concluded that using sodium fluoride (naf) on a daily basis did not affect the force delivery capabilities of orthodontic elastomeric chains. behnaz et al. (15,16) evaluated the effect of whitening kinds of toothpaste and mouthwash on the elastomeric chain force delivery. it was concluded that ordinary toothpaste (from crest) had a lower negative impact on chains than whitening toothpaste and that regular toothpaste had the least negative influence on chains when compared to sensodyne toothpaste (15). on the other hand, it was found that both fluoridated and whitening mouthwash might produce force degradation, with a stronger effect for the whitening mouthwash (16). the effect of different chlorhexidine concentrations on the force delivery of elastomeric chains was studied by pithon et al. (10), who found a nonsignificant effect after four weeks. their findings were in agreement with mirhashemi et al. (14). in contrast, omidkhoda et al. (13) reported a significant effect of chlorhexidine on the force degradation of the elastomeric chain, which could be attributed to ethanol content (13.65%) of the studied mouthwash; as the deleterious effect of alcohol on the elastomeric chains force delivery was reported by larrabee et al. (9) and mahajan et al. (32). j. bagh. coll. dent. vol. 34, no. 4. 2022 issa and kadhum 54 teixeira et al. (33) evaluated the effect of phosphoric acid, citric acid, light coke®, and artificial saliva on the elastomeric chain. following three weeks of immersion, there was no statistically significant difference in force degradation pattern when compared to immersion in artificial saliva. lacerda dos santos et al. (34) had the same conclusion for weak acidic and neutral ph (5.0, 6.0, and 7.5 ph). in contrast, other studies (35, 36) found that coke® (35) and citric acid (36) resulted in an increased force degradation of elastomeric chains, while ferriter et al. (37) reported that the acidic fluoride environment improved force delivery of elastomeric chains. pureprasert et al. (38) found that exposure to sodium hydroxide (naoh), a strong alkaline solution, lowered the maximum forces and delivery forces of various elastic bands. sufarnap (39) reported that polyurethane material can be hydrolyzed when exposed to a strongly acidic ph (ph <5.4) or alkaline ph (ph >8.0). the effect of sterilization traditional sterilization procedures (like dry heat sterilization) are not feasible due to the heatsensitive nature of elastomeric chains, and autoclaving them resulted in force deterioration (40). when elastomeric chains were immersed in glutaraldehyde-containing solutions for 30 minutes (disinfection protocol), force degradation was found to be non-significant, until immersion time was increased up to 10 hours (sterilization protocol) when the effect became significant (41, 42). immersion in 0.12% chlorhexidine for 10 minutes (disinfection protocol) and peracetic acid for 30 minutes was found to be non-significant (11). pithon et al. (43) analyzed the effect of different methods of sterilization (70% alcohol, glutaraldehyde, ethylene oxide, autoclave, microwave, ultraviolet (uv), and gamma rays) on the cytotoxicity of elastomeric chains. they found that sterilizing elastics with ethylene oxide, uv, and gamma rays had no effect on their cytotoxicity; nevertheless, cytotoxicity was raised by autoclaving, glutaraldehyde, 70% alcohol, and microwaving. one of the significant flaws in this study is that they did not examine the mechanical impacts of these sterilization techniques. so, pithon et al. (44) in 2015 studied the mechanical influence of these sterilization methods; they found no significant effect on elastomeric chain force delivery. they also reported that the uv is not completely efficient for the sterilization of elastomeric chains. effects of pre-stretching kim et al. (17) studied the effect of pre-stretching on transparent closed elastomeric chains (from ormco company). they compare experimental group being pre-stretched to 100% of their initial length with non-stretched control group. the initial force was significantly lower in pre-stretched group; one hour later, both experimental and control groups had similar readings. the rate and pattern of force degradation were very similar from one hour to four weeks. baty et al. (19) concluded in their literature review that the improvements were minor (although statistically significant) and unlikely to be clinically relevant, given that the pre-stretching resulted in a 5% less force degradation at three weeks. with a force reduction of 50 to 75%, a 5% change is unlikely to be clinically significant. a similar conclusion was reached by halimi et al. (40) in a systematic review. however, chang et al. (45) reported that the pre-stretching has no disadvantages like permanent deformation of the elastomeric chain, which could affect its force recovery ability, and considered it a beneficial technique that should be practiced. clinical efficacy of elastomeric chains andrew l. sonis (46) compared niti coil springs to elastic. he sought to avoid the initial force degradation of elastics by using a material that delivers selectable tooth moving forces with the desired effects. this study showed that niti coil springs were superior to elastomeric chains as they delivered j. bagh. coll. dent. vol. 34, no. 4. 2022 issa and kadhum 55 a constant force over a wide range of lengths without permanent deformation, which nearly produced twice the rate of tooth movement. santos et al.(47) and pires et al. (48), in in vitro studies, concluded that niti closed coil springs are more suitable for dental movement than elastomeric chains. however, a more recent study (as mentioned earlier) by khanemasjedi et al. (25) reported that monthly replacement of thermoset elastomeric chain gave a comparable speed of tooth movement to that with niti coil spring; this is consistent with earlier studies done by nightingale and jones (49), and bokas and woods (50). in a split-mouth trial, barsoum et al. (51) reported no significant difference in canine retraction when employing elastomeric chins, other than the patient experiencing increased pain for longer days. on the other hand, another study by evans et al. (18) found that elastomeric chains were capable of producing efficient tooth movement for nearly up to 16 weeks, as compared to those changed every four weeks. this shows a considerable improvement in the manufacturing process as well as the continued development of the chain material. conclusions 1. generally, the force level of elastomeric chains degrades rapidly over time, with the majority of degradation occurring during the first 24 hours, after which the rate reduces by time. 2. differences in elastomeric chains configurations, manufacturer, and especially their types (either thermoset or thermoplastic) affect their initial force and degradation pattern over time, so a clear distinction between them is recommended. 3. the initial force and force degradation rate is lower in thermoset type than the thermoplastic ones. 4. it may be recommended to stretch the thermoplastic elastomeric chains to 50-75% of their original length to achieve an initial force around 300 gm, whereas the thermoset type needs more stretching, to achieve the same force. 5. the pre-stretching to decrease force degradation appears to be of minimal clinical value; however, no clinical disadvantages are present. 6. environmental factors like tooth movement, salivary enzymes, alcohol-containing mouthwash, whitening mouthwash, and alkaline and strong acidic ph (<5.4) all have a significant impact on elastomeric chain force degradation, whereas sodium fluoride and chlorhexidine mouthwashes (in different concentrations) and temperature changes within the oral cavity (4-55°c) have no negative impact. 7. cold disinfection protocol is recommended. ethylene oxide and gamma rays are preferred to avoid the risk of cytotoxicity. conflict of interest: none. references 1. oertel g, polyurethane handbook, second ed., germany, hanser publications, 1994. 2. bousquet ja, tuesta o, flores-mir c. in vivo comparison of force decay between injection molded and die-cut stamped elastomers. am j orthod dentofacial orthop. 2006;129(3):384-389. 3. cheng hc, chen ms, peng by, lin wt, shen yk, wang yh. surface treatment on physical properties and biocompatibility of orthodontic power chains. biomed res int. 2017 apr 30;2017. 4. andreasen gf, bishara se. relaxation of orthodontic elastic chains and midules in vitro and in vivo. angle orthod. 1970;40(3):151-8. 5. hershey hg, reynolds wg. the plastic module as an orthodontic tooth-moving mechanism. am j orthod dentofacial orthop. 1975;67(5):554-562. 6. david c, mcinnes-ledoux p, weinberg r, shaye r. force degradation of orthodontic elastomeric chains—a product comparison study. am j orthod. 1985 may 1;87(5):377-84. j. bagh. coll. dent. vol. 34, no. 4. 2022 issa and kadhum 56 7. killiany dm, duplessis j. relaxation of elastomeric chains. j clin orthod: jco. 1985 aug;19(8):592-3. 8. eliades t, eliades g, silikas n, watts dc. in vitro degradation of polyurethane orthodontic elastomeric modules. j oral rehabil. 2005;32(1):72-7. 9. larrabee tm, liu ss, 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chain. j int soc prev community dent. 2014 nov;4(suppl 1):s32. 25. khanemasjedi m, moradinejad m, javidi p, niknam o, jahromi nh, rakhshan v. efficacy of elastic memory chains versus nickel–titanium coil springs in canine retraction: a two-center split-mouth randomized clinical trial. int orthod. 2017 dec 1;15(4):561-74. 26. sulaiman th, eriwati yk, indrani dj. effect of temperature on tensile force of orthodontics power chain in artificial saliva solution. j phys conf ser. 2018 aug 1 (vol. 1073, no. 6, p. 062006). iop publishing. https://doi.org/10.1088/1742-6596/1073/6/062006 j. bagh. coll. dent. vol. 34, no. 4. 2022 issa and kadhum 57 27. von fraunhofer ja, coffelt mp, orbell gm. the effects of artificial saliva and topical fluoride treatments on the degradation of the elastic properties of orthodontic chains. angle orthod. 1992 dec;62(4):265-74. 28. kemona a, piotrowska m. polyurethane recycling and disposal: methods and prospects. polymers. 2020 aug;12(8):1752. 29. andhare p, datana s, agarwal ss, chopra ss. comparison of in vivo and in vitro force decay of elastomeric chains/modules: a systematic review and meta analysis. j world fed orthod. 2021 dec;10(4):155-162. 30. ramazanzadeh ba, jahanbin a, hasanzadeh n, eslami n. effect of sodium fluoride mouth rinse on elastic properties of elastomeric chains. journal of clinical pediatric dentistry. 2009;34:189-192. 31. javanmardi z, salehi p. effects of orthokin, sensikin and persica mouth rinses on the force degradation of elastic chains and niti coil springs. j dent res dent clin dent prospects. 2016;10(2):99. 32. mahajan v, singla a, negi a, jaj hs, bhandari v. influence of alcohol and alcohol-free mouthrinses on force degradation of different types of space closure auxiliaries used in sliding mechanics. j indian orthod soc. 2014;48(4_suppl4):546-51. 33. teixeira l, pereira bdo r, bortoly tg, brancher ja, tanaka om, guariza-filho o. the environmental influence of light coke, phosphoric acid, and citric acid on elastomeric chains. j contemp dent pract. 2008;9:17-24. 34. lacerda dos santos r, pithon mm, romanos mt. the influence of ph levels on mechanical and biological properties of nonlatex and latex elastics. angle orthod. 2012;82(4):709-14. 35. nattrass c, ireland aj, sherriff m. the effect of environmental factors on elastomeric chain and nickel titanium coil springs. eur j orthod. 1998 apr 1;20(2):169-76. 36. khaleghi a, ahmadvand a, sadeghian s. effect of citric acid on force decay of orthodontic elastomeric chains. dental research journal. 2021;18. 37. ferriter jp, meyers jr ce, lorton l. the effect of hydrogen ion concentration on the force-degradation rate of orthodontic polyurethane chain elastics. am j orthod dentofacial orthop. 1990;98(5):404-10. 38. pureprasert t, anuwongnukroh n, dechkunakorn s, loykulanant s, kongkaew c, wichai w. comparison of mechanical properties of three different orthodontic latex elastic bands leached with naoh solution. key eng mater. 2017; (vol. 730, pp. 135-140). trans tech publications ltd. 39. sufarnap e, harahap ki, terry t. effect of sodium fluoride in chlorhexidine mouthwashes on force decay and permanent deformation of orthodontic elastomeric chain. padjadjaran journal of dentistry. 2021 mar 31;33(1):74-80. 40. halimi a, benyahia h, doukkali a, azeroual mf, zaoui f. a systematic review of force decay in orthodontic elastomeric power chains. int orthod. 2012; 10(3):223-240. 41. jeffries cl, von fraunhofer ja. the effects of 2% alkaline gluteraldehyde solution on the elastic properties of elastomeric chain. angle orthod. 1991 mar;61(1):26-30. 42. martins mm, lima ta, areas ac. influence of glutaraldehyde solutions 2% in the forces generated by orthodontic elastic chains. cienc odontol bras. 2008;11:49-57. 43. pithon mm, dos santos rl, martins fo, romanos mt, araújo mt. cytotoxicity of orthodontic elastic chain bands after sterilization by different methods. orthod waves. 2010 dec 1;69(4):151-5. 44. pithon mm, ferraz cs, rosa fc, rosa lp. sterilizing elastomeric chains without losing mechanical properties. is it possible?. dental press journal of orthodontics. 2015 may;20:96-100. 45. chang jh, hwang cj, kim kh, cha jy, kim km, yu hs. effects of prestretch on stress relaxation and permanent deformation of orthodontic synthetic elastomeric chains. korean j orthod. 2018 nov;48(6):384-394. 46. sonis al. comparison of niti coil springs vs. elastics in canine retraction. j clin orthod. 1994 may;28(5):293. https://doi.org/10.15171/joddd.2016.016 https://doi.org/10.5005%2fjp-journals-10021-1313 j. bagh. coll. dent. vol. 34, no. 4. 2022 issa and kadhum 58 47. santos ac, tortamano a, naccarato sr, dominguez-rodriguez gc, vigorito jw. an in vitro comparison of the force decay generated by different commercially available elastomeric chains and niti closed coil springs. brazilian oral research. 2007 mar;21(1):51-7. 48. pires bu, de souza re, vedovello filho m, degan vv, dos santos jc, tubel ca. force degradation of different elastomeric chains and nickel titanium closed springs. brazilian journal of oral sciences. 2011;10(3):167-70. 49. nightingale c, jones sp. a clinical investigation of force delivery systems for orthodontic space closure. journal of orthodontics. 2003 sep;30(3):229-36. 50. bokas j, woods m. a clinical comparison between nickel titanium springs and elastomeric chains. australian orthodontic journal. 2006 may;22(1):39-46. 51. barsoum ha, elsayed hs, el sharaby fa, palomo jm, mostafa ya. comprehensive comparison of canine retraction using niti closed coil springs vs elastomeric chains. angle orthod. 2021 jul 1;91(4):441-448. العنوان: تضاؤل قوة السالسل المرنة التقويمية: مراجعة النتاج الفكري , عمار سالم كاظم الباحثون: علي رحمن عيسى الملخص بمرور الوقت، مما قد يؤثر على تتضاءلاهداف البحث: تُستخدم السالسل المرنة لتوليد القوة في العديد من إجراءات تقويم األسنان، لكن هذه القوة ة.القوة في السالسل المرن تضاؤلحركة األسنان. هدفت هذه الدراسة إلى دراسة وتم تضمين (central ،medline ، lilacs ،pubmed) البيانات االلكترونية في قواعد البيانات والمصادر: تم إجراء بحث إلكتروني .2022حتى يناير فقط،المقاالت المكتوبة باللغة اإلنجليزية . سريرية شوائيةعمقالة أصلية ومراجعات منهجية وتجارب خمسين اختيار الدراسة: تم اختيار األسنان، حركة الكحول، وغسولاللعابية، واإلنزيماتاالستنتاجات: على المحتوي المبيض، وغسول الفم عالية والفم العالية القلويمحاليل أو ة معدل مستوى قوة السالسل المرنة بسرعة بمرور الوقت؛ ومع ذلك فإن يتضاءلالمرنة. في السالسل تضاؤل القوة كلها لها تأثير كبير على الحمضية السالسل المتصلبة . يمكن تحقيق حركة أسنان فعالة باستخدام السالسل اللدنة بالحرارةمنه في السالسل المتصلبة بالحراراةأبطأ في تضاؤل القوة .مخاطر السمية الخلويةالغاما لتجنب واشعةثيلين يفضل استخدام طرق التعقيم بأكسيد األشهري. الستبدال المع ابالحرارة zuha.doc j bagh college dentistry vol. 27(2), june 2015 evaluation of the restorative dentistry 43 evaluation of the cleaning efficiency of the isthmus using different rotary instrumentation techniques (in vitro study) zuha ayad jaber, b.d.s. (1) hussain faisal al-huwaizi, b.d.s., m.sc., ph.d. (2) abstract background: the aims of the study were to evaluate the unclean/clean root canal surface areas with a histopathological cross section view of the root canal and the isthmus and to evaluate the efficiency of instrumentation to the isthmus using different rotary instrumentation techniques. materials and methods:the mesial roots of thirty human mandibular molars were divided into six groups, each group was composed of five roots (10 root canals)which prepared and irrigated as: group one a: protaper system to size f2 and hypodermic syringe, group one b: protaper system to size f2 and endoactivator system, group two a:wave one small then primary file and hypodermic syringe, group two b:wave one small then primary file and endoactivator system, group three a: step back technique to size 25 file as mafand hypodermic syringe, group three b: step back technique to size 25 file as mafand endoactivator system . all the roots were sectioned at 2mm, 6mm ,12mm from the apex and studied by histopathological cross section. the degree of cleaning of each section was measured by the use of autocade 2004 software system. result :the least uncleaned isthmus surface area at coronal, middle and apical section was found by the protaper system with endoactivator which represented the mean of the percentage of uncleaned surface area of 16.87%, 14.32% and 9.55% respectively. the system that produced least uncleaned canal wall was by protaper system with endoactivator at coronal ,middle ,and apical sections of 12.21%, 9.14% and 18.55% respectively . the mean of highest percentage of increased canal diameter which was protaper system, wave one system and then step back. the comparison between the groups in the means which showed that the highest percentage of decrease in isthmus area was with the protaper system, wave one system and lastly the step back. conclusions:the protaper system with endoactivator was the best system in canal and isthmus cleaning. keywords: isthmus cleaning, canal cleaning, canal diameter, isthmus size. (j bagh coll dentistry 2015; 27(2):43-47). introduction the root canal system of a tooth is often extremely complex and it is difficult to disinfect completely and quickly. it may be that the best attempts of the operator just to reduce the residual bacterial load to a non-pathogenic number, or change the resident flora sufficiently to allow periapical healing.these microbes and their byproducts can be removed by a combination of mechanical and chemical means. mechanical removal relies on the ability of the operator to remove infected pulp and dentine from the surfaces of the root canal by planning the walls; infected material in the lumen of the root canal will be removed. the isthmus is a narrow connection between two root canals usually containing pulp tissue. it was called a "corridor" by green in (1973)(2) also called "lateral connection" by pineda in 1973(3) and an anastomosis by vertucci in 1984(4). in many teeth with a fused root there is a weblike connection between two canals called an isthmus, which can be either complete or incomplete (5), (1)master student, department of conservative dentistry, college of dentistry,university of baghdad. (2)professor, department of conservative dentistry, college of dentistry,university of baghdad. which is formed when an individual root projection is unable to close by itself. in clinical practice, this isthmus is important in the surgical and non surgical endodontic procedures. in both cases, it can lead to failure because of poor accessibility to root canal instruments, acts as bacterial reservoir and may reduce the success rate (6) . materials and methods sampling seventy nine human mandibular first molars were collected and only thirty teeth were selected depending on the inclusion criteria . the inclusion criteria of the mesial roots that were involved in this study are: 1. the length between the orifice and the apex was 12 mm. 2. presence of the isthmus between the root canals. 3. no crack presented in the root. 4. the apical part of the root presented not fractured. 5. the root apex is closed not open apex. the crown and distal root were sectioned using prosthetic engine with straight hand piece (w&h, austria) by thin diamond disk and removed. j bagh college dentistry vol. 27(2), june 2015 evaluation of the restorative dentistry 44 grouping group one: ten teeth (20 root canals) were prepared by rotary protaper universal system. this was accomplished by establishing a smooth glide path with iso no. 10 stainless steel hand files . preparation of the root canal started by: sx and then s1 instruments, preparing the coronal third of root canal. then s2 instrument was used to prepare the middle third of root canal 1.0 ncm . f1 instrument and finally f2 instrument were used to prepare the apical third of root canal (7) . group two: ten teeth were prepared by wave one system; reproducible glide path equivalent to a loose 10 file, then started by the small (21/06) file, irrigated, recapitulated with a 10 file, then reirrigated. then primary (25/08) file was used for a full working length of 1 mm shorter than the apex (8) , irrigated, recapitulated with a 10 file, then reirrigated. group three: ten teeth were prepared by stepback technique; started by:used of size 10 file to full working length which was 11mm,then used of size 15 file to full working length which was 11mm,then used of size 20 file to full working length which was 11mm, then used of size 25 file to full working length (regarded as a master apical file).after that increased one size and subtract 1mm at each time until reached the canal orifice at size 90 k-file(9) . each group was subdivided into two subgroups each contained 5 roots (10 root canals); subgroup a was irrigated by normal saline and hypodermic syringe, subgroup b was irrigated by normal saline and endoactivator system by insertion of the tip size 20 for 30 seconds for each root canal. the canals were irrigated between each instrument with 10 ml. normal saline divided according to the number of instrument used in each group . histological procedure after preparation: for each subgroup, the roots were placed in a container and written the name of subgroup on it. the roots of all groups were placed in a formalin solution (10 %) for 3 days for fixation.then the roots were placed in nitric acid solution (5 %) also for 3 days for decalcification for complete removal of calcium ions from the teeth.after that, the roots were sectioned at 2mm, 6mm, and 12mm from the apex respectively .the block of each root sections was embedded in a solid medium such as paraffin wax. the block of each root and paraffin wax was cut by using microtoms to 4 micron thickness section . the sections were fixed on a slide by using adhesive&stained with h&e stain then washed by tap water .mounting the cover slide on the slide by using canada balsam or dpx. finally the slide was ready for microscopic evaluation(10) . microscopic evaluation: the slides were read by light microscope at 40x magnification power, then a high resolution picture was taken to each section on the slide by dcm 35 digital eye piece camera. study one: evaluated the unclean to clean root canal wall percentage. the sections were stained by h&e stain to verify the organic debris at the inner wall of the root canal. each canal was divided to four part to be seen the whole canal outline under magnification power 40x. then a microscopic picture of canals was drawn by soft ware autocade 2004 system for sections at 12mm, 6mm, 2 mm from the apex for each sub group to show the unclean to clean surface area as percentage by draw first the canal to represent the whole area tracing the outline of the root canal by using poly line by soft ware autocade 2004. then draw the unclean part and measured the unclean part and subtracted the uncleaned part to cleaned part as percentage to all canal area. fig 1: aclean canal wall. bunclean canal wall. study two: evaluated the unclean to clean surface percentage in the isthmus. this procedure was done in the same way as the previous study, but the isthmus was included in this study.the isthmus was calculated from the imaginary continuous line of the circle of the root canal. the isthmus was divided into two parts and a microscopic picture was taken under magnification power 40x, then isthmus was drawn by soft ware autocade 2004 system for sections at 12 mm from the apex (root canal orifice), 6 mm from the apex, 2 mm from the apex for each sub group to show the unclean to clean surface area as a percentage by draw first the isthmus of each canal to represent the whole area by tracing the border of the isthmus then draw the unclean part and subtracted the uncleaned part to cleaned part as percentage to all canal area. j bagh college dentistry vol. 27(2), june 2015 evaluation of the restorative dentistry 45 fig 2: aclean isthmus wall. bun clean isthmus wall. study three: which measured : athe percentage of increase in canal diameter by using different rotary systems at root canal orifice. bthe percentage of decrease of isthmus size at the orifice region. high resolution picture was taken by digital camera for each root before and after preparation at level of root canal orifice and the magnification used was 100x. the root was placed in aplastic mold which made from slicon and it diamension was 2 cm length ,3 cm width and 2 cm elevation as a holder to maintain the same position of the root before and after preparation. the ruler was placed beside the mold to obtain the correct dimension measurement. the camera was placed at fixed position on the table and at the same distance from each root which was 20 cm during picture capturing, to prevent any variation in dimension between roots during measurement and comparison between dimensions. then autocad 2004 soft ware system was used to draw each canal and isthmus by using poly line to draw the outline of canals and isthmus before and after instrumentation to measure the difference in canal diameter before and after instrumentation,and thelength of isthmus before and after instrumentation for each group.then a formula was used to show the percentage of increasing in canal diameter which was (canal diameter after instrumentation-canal diameter before instrumentation) *100/canal diameter before instrumentation.the percentage of decreasing in isthmus size after instrumentation was measured by formula which was (isthmus size after instrumentationisthmus size before instrumentation) *100/ isthmus size before instrumentation . fig 3: a-mesial root before instrumentation b-after instrumentation by protaper files. fig 4: amesial root before instrumentation bafter instrumentation by wave one files. fig 5 :amesial root before instrumentation bafter instrumentation by step back technique. results the comparison among the six groups in the percentage of unclean root canals surface area after instrumentation the least uncleaned root canal surface area according to preparation techniques was protaper system,and according to the irrigation systems was endoactivator system. table 1: the means of percentage of unclean root canals surface area at 12mm,6mm,2mm from the apex . groups sections 3b 3a 2b 2a 1b 1 a 35.94 38.06 15.05 22.13 12.21 15.85 12mm from apex 25.19 28.04 13.7 17.17 9.14 14.77 6 mm from apex 20.51 23.4 19.05 24.22 18.55 22.02 3 mm from apex the comparison among the six groups in the percentage of unclean isthmus surface area after instrumentation. the least uncleaned isthmus area according to preparation techniques was protaper system ,and according to the irrigation systems was endoactivator system. j bagh college dentistry vol. 27(2), june 2015 evaluation of the restorative dentistry 46 table 2: the means of percentage of the unclean isthmus area at 12mm,6mm,2mm from the apex. groups sections 3b 3a 2b 2a 1b 1 a 25.72 32.82 20.52 32.44 16.72 30.38 12mm from apex 22.8 23.93 15.5 18.3 14.36 21.72 6 mm from apex 17.75 18.33 12.13 14.35 9.55 13.25 3 mm from apex the comparison among the protaper, wave one and step back systems: 1-in the percentage of increase root canals diameter after instrumentation at the orifice area. table 3:the means of the percentage of increase in canal diameter at the canal orifice area. mean canal preparation techniques 81.05 protaper 58.13 wave one 53.80 step back 2-in the percentage of decrease isthmus size after instrumentation at the orifice area. table 4: the means of the percentage of decrease in isthmus size at the canal orifice area. mean canal preparation techniques 33.43 protaper 29.41 wave one 16.24 step back discussion the comparison among the six groups in the percentage of unclean root canals surface area after instrumentation at 12 mm, 6 mm and 2 mm sections from apex. the least un-clean surface area of root canal at 12 mm, 6 mm sections from apex according to preparation techniques was the protaper system,then waveone system and lastly stepback system,and according to irrigation techniques was endoactivator then hypodermic syringe.but at 2mm section the least un-clean surface area of root canal according to preparation techniques was the protaper system,then stepback system and lastly waveone system this may be due to the use of multiple instruments (5 files) during the protaper preparation and brushing action against canal wall, while only 2 files were used during wave one preparation.the result was best by using endoactivator system than without it. this may be due to the acoustic streaming due to sonic activation to irrigation fluid. the result of this study at 12mm,6mm,2mm agrees with the finding of burklein et.al 2012(11) , which showed that the protaper system removes more smear layer and cleans better than wave one. the finding of rodig et.al 2010(12) agrees with the present study as it shows more smear layer removal at coronal region is effective when endoactivator system was used. also the result of the study at 6mm,2mm agree with the finding of luciana et.al 2011 (13)showed that sonic irrigation is better in smear layer removal middle third of the canal than conventional irrigation which agree with this study. uma et.al in 2010(14) got comparable result with this study when they found that endoactivator better cleaned the middle third of the canal from debris. also the result of the study at 2mm agree with the finding of luiz et.al 2011(15) showed that none of hand or rotary instrument was totally effective in cleaning apical root canals space. the comparison among the six groups in the percentage of unclean isthmus surface area after instrumentation at 12 mm, 6 mm, and 2 mm sections from apex. the least un-clean surface area of root canal at 12 mm, 6mm and 2 mm sections from apex according to preparation techniques was the protaper system,then waveone system and lastly stepback system,and according to irrigation techniques was endoactivator then hypodermic syringe. this may be due to the use of multiple instruments (5 files) during the protaper preparation and brushing action against canal wall, while only 2 files were used during wave one preparation.the result was best by using endoactivator system than without it. this may be due to the acoustic streaming due to sonic activation to irrigation fluid.the result of protaper system with hypodermic syringe at 12mm from apex was 30.44% of unclean isthmus area more debris removal and accumulation in isthmus which is removed by using endoactivator, the debris were dislodged and removed resulting in better cleaning. this result of least un-clean surface area of root canal at 12 mm, 6mm and 2 mm sections from apex agrees with gencoglu and gundogar 2008(16) who showed ultrasonic instrument is useful to clean isthmus of mesial root of mandibular molars which supports the use of j bagh college dentistry vol. 27(2), june 2015 evaluation of the restorative dentistry 47 endoactivator system. this study disagrees with mathew 2012 (17) who presented wave one is the worst in isthmus cleaning. the present findings agree with of susin et.al 2010 (18) that no irrigation techniques produce completely removed debris from isthmus regions. also the result of least un-clean surface area of root canal at 6mm and 2 mm sections from apex agrees with unni et.al 2011(19)which supported the present study's findings that rotary system with endoactivator never reached 100% cleaning. as conclusions; the best cleaning result for root canal walls 12 mm, 6 mm and 2 mm from the apex were the protaper system, then wave one system and lastly the step back technique.the endoactivator irrigation system presented better results than the manual hypodermic syringe when used with all the instrumentation systems.the best cleaning result for isthmus walls cleaning 12 mm, 6 mm and 2 mm from the apex were the protaper system, then wave one system and lastly the step back technique. maximum coronal orifice widening was presented in the protaper system, followed by wave one system, then step back system.the system that performed maximum decreasing in the isthmus area after instrumentation was the protaper system, followed by wave one system, then step back system. references 1. pitt ford tr, rhodes js, pitt ford he. endodontics problem-solving in clinical practice, 1st ed. london: martin dunitz ltd; 2002. 2. green d. double canals in single roots. oral surg 1973; 35:689. 3. pineda f. roentgenographic investigation of the mesiobuccal root of the maxillary first molar. oral surg 1973; 36: 253. 4. vertucci fj. root canal anatomy of the human permanent teeth. oral surgery, oral medicine, oral pathol 1984; 58: 5: 589–99. 5. cohen s, burns rc. pathway of the pulp. 8th ed. mosby inc.; 2002. p. 244-5. 6. teixeira fb, sano cl, gomes bp, zaia aa, ferraz cc, souza-filho fj. a preliminary in vitro study of the incidence and position of the root canal isthmus in maxillary and mandibular first molars. int endod j 2003; 36(4): 276-80. 7. yoo y, cho y. a comparison of the shaping ability of reciprocating niti instruments in simulated curved canals. restorative dentistry and endod 2012; 37: 220 8. goldberg m, dahan s, machtou p. centering ability and influence of experience when using waveone single-file technique in simulated canals. intern dentistry 2012; article id 206321. 9. lumley pj. cleaning efficacy of two apical preparation regimens following shaping with hand files of greater taper. int endod j 2000; 33(3): 262-5. 10. bancroft jd, stevens a. theory and practice of histological techniques. 3rd ed. edinburgh, london, melbourne and new york: churchill livingstone inc.; 1990. 11. bürklein s, hinschitza k, dammaschke t. shaping ability and cleaning effectiveness of two single-file systems in severely curved root canals of extracted teeth: reciproc and wave one versus m two and protaper. int endod j. 2012 ; 45(5):449-61. 12. rödig t, döllmann s, konietschke f, drebenstedt s, hülsmann m. effectiveness of different irrigant agitation techniques on debris and smear layer removal in curved root canals: a scanning electron microscopy study. j endod 2010; 36(12):1983-7. 13. blank-gonçalves lm, nabeshima ck, ghr, machado me. qualitative analysis of the removal of the smear layer in the apical third of curved roots: conventional irrigation versus activation systems. j endod 2011; 37(9):1268-71 14. nair up, marianella n, kevin k, prathibha p, claudio h, robertap. comparative evaluation of three different irrigation activation on debris removal from root canal systems. revista presei medicale intern 2011;1: 67-70 15. silveira lfm, bosembecker jk, martos j, ferrerluque cm. the quality of apical preparation in curved root canals using hand and rotary instrumentation techniques. arch oral res 2011;7(3): 231-7 16. gencoglu n, gundogar m. cleaning effect of ultrasonic debridement on isthmus in mandibular molars, marmara university, istanbul, turkey, queen elizabeth ii conference centre poster hall 1the pan european federation of the international association for dental research (september 1012, 2008). 17. dietrich ma, kirkpatrick tc, yaccino jm. in vitro canal and isthmus debris removal of the selfadjusting file, k3, and waveone files in the mesial root of human mandibular molars. j endod 2012; 38:1140–4. 18. susin l, liu y, yoon jc, parente jm, loushine rj, ricucci d, bryan t, weller rn, pashley dh, tay fr. canal and isthmus debridement efficacies of two irrigant agitation techniques in a closed system. int endod j 2010; 43(12):1077-90. 19. endal u, shen y, knut a, gao y, haapasalo m. a high-resolution computed tomographic study of changes in root canal isthmus area by instrumentation and root filling. j endod 2011; 37: 223–7. muna f.doc j bagh college dentistry vol. 25(4), december 2013 incidence of hodgkin's oral diagnosis 49 incidence of hodgkin's lymphoma of head and neck in baghdad city ahlam h. majeed, b.d.s., m.sc. (1) muna s. merza, b.d.s., m.sc., ph.d. (2) abstract background: hodgkin's lymphoma (hl), formerly called hodgkin's diseases is an uncommon form of lymphoma. the incidence of hodgkin's lymphoma shows marked heterogeneity with respect to age, gender, race, geographic area, social class and histological subtype. this study was carried out in an attempt to evaluate the incidence of hodgkin's lymphoma of head and neck in baghdad city. materials and methods: the diagnosed cases of hodgkin's lymphoma of head and neck region in baghdad city between (1990-1999) were collected and analyzed according to age, gender, site and the histopathological subtypes of the tumor. results: out of (702) cases of hodgkin's lymphoma of ten years between (1990-1999),(362 ) of them were occurred in the head and neck region including (202) males and (160) females. the remaining (340) cases were occurred in other lymph nodes of the body. conclusion: this study revealed that predominant histopathological subtype of hodgkin's lymphoma is the mixed cellularity type that showed more predominance in male especially among young age groups and low incidence with advancing age. keywords: hodgkin's lymphoma, head and neck, incidence. (j bagh coll dentistry 2013; 25(4):49-51). introduction hodgkin’s lymphoma (hl) is a lymphoproliferative malignancy of b-cell origin (1). according to the who classification, hodgkin's lymphoma (hl) is divided into a classical variant and a nodular lymphocyte predominant variant which are characterized by the presence of hodgkin's and reed-sternberg (hrs) cells or lymphocytic and histiocytic (l&h) cells, respectively (2). classical hl is separated into four subtypes: lymphocyte rich type, nodular sclerosis type, mixed cellularity type and lymphocyte depleted type. however, recent evidence suggests that classical hodgkin lymphoma is not a single disease. while the mixed cellularity and lymphocyte depleted subtypes may be a part of a biologic continuum, the nodular sclerosis subtype has a distinct epidemiology, clinical presentation and histology (3). nodular lymphocyte predominant hodgkin's lymphoma (nlphl) is no longer classified as a form of classic hodgkin's lymphoma (hl). this is because the reed-sternberg cell (rsc) variants (popcorn cells) that characterize this form of the disease invariably express b lymphocyte markers such as cd20 (thus making nlphl an unusual form of b cell lymphoma), and that (unlike classic hl) nlphl may progress to diffuse large b cell lymphoma (4). (1) professor, department of oral pathology, college of dentistry, baghdad university. (2) assistant professor, department of oral pathology, college of dentistry, baghdad university. regarding etiology, hodgkin’s lymphoma has long been suspected to have an infectious precursor, and indirect evidence has implicated epstein-barr virus (ebv), as a causal agent. the epstein-barr virus (ebv) plays an important role and individuals with a history of infectious mononucleosis have an increased incidence of hodgkin's lymphoma, but the precise contribution of epstein–barr virus remains largely unknown (5). other risk factors may include an hiv infection, a family history of hodgkin's lymphoma, and previous chemotherapy or radiation exposure. people who have suppressed immune systems due to certain medications or medical conditions may also be at risk. the diagnosis of hl rests on recognizing reed-sternberg cells in a cellular background appropriate to one of the sub-types of the disease. despite the application of many techniques including cell culture, immunohistochemistry and studies of gene re-arrengment, the histogenesis of reed-stenberg cell remain elusive (6). materials and methods this study includes all the cases diagnosed as hl in baghdad city that were collected from iraqi cancer board over ten years (1990-1999). the cases were evaluated regarding age, gender, primary site and histopathological subtype of the tumor. results this study revealed that the total number of diagnosed cases of hl in baghdad city between (1990-1999) were (702). out of them, (362) cases were occurred in head and neck region. the j bagh college dentistry vol. 25(4), december 2013 incidence of hodgkin's oral diagnosis 50 remaining (340) cases were occurred in other areas of the body (table 1). the age range of the patients was between (380) years with a mean of age was (28) years and median of (25) years including (202) males and (160) females. concerning age distribution of the patients, the higher affected age group was between (1120) years old followed by age group (21-30) years old. table (2) illustrated the distribution of the patients’ gender in relation to age groups. this table revealed that female predominated in the age groups of (0-10) and (11-20) years old while males in remaining age groups were more affected than females. the site distribution of hl that occurred in head and neck region revealed that the most common affected site was the cervical lymph nodes which represent (46.15%) of the cases followed by the supraclavicular lymph nodes which constitute (5.13%) of the cases and only two cases in the submandibular lymph nodes. as far as the histopathological subtypes is concerned, table (3) revealed that the most predominant subtype is the mixed cellularity type which represent (54.69%) of the cases followed by nodular sclerosing type which represent (17.4%) of the cases and lymphocyte predominant type was (9.94%) of the cases while the lymphocyte depletion type constitute only (4.41%) of the cases. the remaining 49 cases were unclassified .the relation of histopathological subtypes to age groups and gender were demonstrated in (table 4) and (table5) respectively. discussion this study involves a review of the reported cases of hodgkin's disease in baghdad city of ten years between (1990-1999). our results revealed that more than half of the total reported cases were affected head and neck region. the majority of the cases affected cervical lymphnodes; this is in agreement with other studies which might reflect initiation by an infective process (7). regarding the relation of age group to gender, younger age group showed an approximately equal male to female ratio except those below 10 years who showed similarity to old age by having higher male to female ratio. there has long been a view that the differences in descriptive epidemiology of hodgkin’s lymphoma around the world, and also between children, young adults and older adults may reflect differences in etiology between them (8). concerning the histopathological subtypes, result of present study revealed highest incidence of mixed cellularity subtype and become progressively less from nodular sclerosing to, lymphocyte predominant to lymphocyte depletion subtype. this finding come in accordance with different studies in most asian countries such as iran, korea, thailand and japan that showed the common subtype is the mixed cellularity and relative paucity of nodular sclerosing subtype, particularly in males (9)which seems to be related to the etiologic factors of disease (environment and/ or inheritance) (8). correlating the histopathological subtypes to age, a study showed that most common subtype among the young adults, is nodular-sclerosing and the frequency of mixed cellularity increases with age, while that of nodular sclerosing reaches a plateau in the group >30 years of age (10), this is in contrast to present finding which revealed higher incidence of mixed cellularity type among young age groups and low incidence with advancing age.this behavior persist for all other subtypes. the histopathological subtypes in relation to gender, mixed cellularity subtype was more predominant in male while nodular sclerosing type had higher incidence in females, however, other study revealed that men are affected by hl slightly more often than women among all histopathological subtypes (10). the apparent changing pattern of disease from country to country and by time needs careful future studies (11), therefore; the comparison of hl rates in eastern and western countries could reveal the relative importance of environmental and genetic factors in disease etiology (8). table1: distribution of hl in baghdad city between (1990-1999) site no. of cases % % of total head and neck cervical lymph nodes 324 46.15 51.57 supraclavicular lymph node 36 5.13 submandibular lymph node 2 0.3 others 340 48.43 total 702 100% j bagh college dentistry vol. 25(4), december 2013 incidence of hodgkin's oral diagnosis 51 table 2: distribution of patient's gender in relation to age group females males age group (years) 17 48 0-10 48 41 11-20 50 37 30 -21 20 25 31-40 9 24 -5041 16 27 51 160 202 total table 3: histopathologic subtypes of hl according to rye classification % no. of cases histopathologic subtypes 54.69 198 mixed cellularity 17.4 63 nodular sclerosing 9.94 36 lymphocyte predominant 4.41 16 lymphocyte depletion 13.53 49 unclassified 100% 362 total table 4: relation of histopathologic subtypes to age groups table 5: relation of histopathologic subtype to gender lymphocyte depletion lymphocyte predominant nodular sclerosing mixed cellularity genders 9 22 28 115 males 7 14 35 83 females references 1. swerdlov sh, campo e, harris nl, et al. who classification of tumors of haematopoietic and lymphoid tissues. 4th ed. lyon: iarc; 2008. 2. re d, küppers r, diehl v. molecular pathogenesis of hodgkin's lymphoma. j clin oncol 2005; 23(26): 6379-86. 3. mani h, jaffe es. hodgkin's lymphoma: un update of its biology with newer insight in classification. clin lymphoma myeloma 2009; 9(3): 206–16. 4. renné c, martín-subero ji, hansmann ml, siebert r. molecular cytogenetic analyses of immunoglobulin loci in nodular lymphocyte predominant hodgkin's lymphoma reveals a recurrent igh-bcl6 juxtaposition. j mol diagn 2005; 7(3): 352–6. 5. flavell kj, murray pg. hodgkin's disease and the epstein–barr virus. molecular pathology 2000; 53(5): 262–9. 6. harris nl. hodgkin's lymphomas: classification, diagnosis, and grading. jul semin hematol 1999; 36(3): 220-32. 7. alexander fe, lawrence dj, freeland j, krajewski as, angus b, taylor gm, jarrett rf. an epidemiologic study of index and family infectious mononucleosis and adult hodgkin's disease (hd): evidence for a specific association with ebv+ve hd in young adults. nov int j cancer 2003; 107(2): 298302. 8. mozaheb z. epidemiology of hodgkin's lymphoma. health 2013; 5(5a):17-22. 9. glaser sl, hsu jl. hodgkin's disease in asians: incidence pattern and risk factors in population-based data. leukemia res 2002; 26: 261-9. 10. thomas r re,d, zander t, wolf j, diehl v. epidemiology and etiology of hodgkin's lymphoma. annals oncol 2002; 13: 147-52. 11. carwright ra, watkins g. epidemiology of hodgkin's disease: a review. hematological oncology 2004; 22: 11-26. age group (years) mixed cellularity nodular sclerosing lymphocyte predominant lymphocyte depletion 0-10 43 6 10 1 11-20 40 21 10 4 21-30 39 25 5 4 31-40 27 6 3 1 41-50 22 3 4 3 51< 27 2 4 3 total 198 63 36 16 shaimaa.doc j bagh college dentistry vol. 28(1), march 2016 an evaluation of pedodontics, orthodontics and preventive dentistry 153 an evaluation of corrosion pits in esthetic coated stainless steel orthodontic archwires in dry and wet environment at different intervals (an in vitro study) shaimaa k. mohsin, b.d.s. (1) iman i. al-sheakli, b.d.s., m.sc. (2) abstract background: the demand for esthetic orthodontic appliances is increasing; so the esthetic orthodontic archwires were introduced. among them, teflon and epoxy coated stainless steel archwires. the amount of force available from the archwire depends on the structural properties and susceptibility to corrosion. all metallic alloys are changed during immersion in artificial saliva, chlorhexidine mouthwash andtoothpaste, but their behaviors differ from one type to another. they corrode at different rates, which lead to decrease the amount of force applied to the teeth. this in vitro study was designed to evaluate the corrosion pits in stainless steel archwires coated with teflon and with epoxy in dry and after immersion in artificial saliva, chlorhexidine(0.2%) (parodontax) and toothpaste media (sensodyne) for (1, 7 and 28) days intervals. moreover, this study is intended to compare the corrosion pits for each type of archwires at these different media among all intervals. materials and methods: in this study, two hundred forty pieces of orthodontic wires of teflon (hubit) coated stainless steel (120 pieces) and epoxy (orthotechnology) coated stainless steel (120 pieces), rectangular in cross section, size (0.019 x 0.025) inch and 15mm in length divided into four groups according to immersion media: (dry environment group, artificial saliva group, chlorhexidine group and toothpaste group). the atomic force microscope was used to measure the corrosion pits for all samples at dry and wet conditions and after different immersion periods. results: statistical analysis showed that there was a highly significant increase in the corrosion pits of teflon coated stainless steel archwires (p ≤ 0.05) in wet environment at 28 days immersion period.the highest corrosion pits were found in the toothpaste medium for the two archwire types at 28 days immersion period. conclusion: we can conclude that epoxy coatedstainless steel archwires are indicated to be used above teflon coated stainless steel archwires in terms of corrosion resistance. ifteflon coated stainless steel archwires should to be used, they should be change in shorter periods than epoxy coated stainless steel archwires type key words: esthetic coated archwire, corrosion, teflon, epoxy, wet environment, afm. (j bagh coll dentistry 2016; 28(1):153-157). introduction appearance is one of patients' main concerns during orthodontic treatment so there is a growing demand for esthetic appliances (1,2) but most fixed orthodontic appliance components are metallic and silver in color (3). this demand has led to the development of orthodontic appliances with acceptable esthetics both for patients and for clinicians (4). this problem has been partially solved by the introduction of esthetic brackets made of ceramic or composite (5,6). however, most archwires are still made of metal such as stainless steel and nickel-titanium, a number of alternatives have been explored to create an esthetic arch wire (7,8). among these alternatives, coated wires with polymeric materials have been developed (9,10). materials used in the coating process are teflon or epoxy resin. the coating manufactured with a process, which plates the base wire (11). the conditions in the mouth are very suitable for the occurrence of corrosion because the oralcavity is warm and wet. the oral environment is particularly ideal for the biodegradation of (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) assist. professor, department of orthodontics, college of dentistry, university of baghdad. metal because of its thermal, microbiologic and enzymatic properties (12). these environmental conditions of the oral cavity might alter the morphological characteristics of archwires (13). the ideal archwire is the wire that can withstand the extreme conditions of the mouth (14). orthodontic alloys must have excellent resistance to corrosion especially in the oral environment. this corrosion resistance is very important for two reasons first is biocompatibility and second is orthodontic appliance durability (15) understanding the basic material characteristics becomes essential for selecting wires for use in the treatment. materials used in dentistry must have specific characteristics such as biological safety, adequate tissue response, and resistance to corrosion because they remain in the oral cavity and subjected to the oral environment’s physical properties (chemical and microbiological properties), that stimulate the dissolution of metals (16). therefore, the objectives of this study were three. first, to evaluate and compare the effect of teflon and epoxy coating material in the corrosion pits of stainless steel, second, to evaluate and compare the effect of dry and wet environment, and third, to evaluate the effect of immersion time. j bagh college dentistry vol. 28(1), march 2016 an evaluation of pedodontics, orthodontics and preventive dentistry 154 materials and methods total number of (240) pieces of upper-coated stainless steel orthodontic archwires, (120) selected from ortho technology company, (brazil) and (120) selected from hubit company, (korea) were tested for corrosion. the specimens used in the present study having a rectangular (0.019 × 0.025 inch) cross section and cut in to pieces of (15 mm) length. these pieces of wires divided in to four groups according to the media they immersed in them. they subdivided into three groups according to the period of immersion. thirty pieces of each wire’s type were left in dry environment for 1, 7 and 28 days intervals. another thirty pieces of each wire’s type were immersed in artificial saliva (ph = 6.75 ± 0.15) (400 mg/lnacl, 400 mg/l kcl, 795 mg/lcacl2.2h2o, 690 mg/lnah2po4.h2o, 5 mg/l na2s.9h2o, 1000 mg/l urea, 500 ml deionized water, 500ml distilled water)(17,18,19), chlorhexidine mouthwash (gsk, germany, exp: 06 /2015) and toothpaste (gsk, uk, exp: 06 /2015). these wire’s pieces were incubated in covered glass containers at 37c˚ for the entire testing period (20). the corrosion pits measurements made at the following time intervals: 1day, 7 days and 28 days. corrosion pits measurements were obtained by atomic force microscope (afm; jpk nanowizard, nr: h-01-0086, and jpk image processing software, version 3.0; jpk instruments ag, berlin, germany) with a non-contact tip coated with silicon (nclr-20; nanoworld, neuchatel, switzerland), with a constant force of 48 n/mm and resonance frequency of 190 khz (figure 1). after preparation, the samples were washed withdistilled water and immersed in 70% ethanol for 4-5 seconds and thenimmersed in acetone (act as a volatile organic solvent) for 8-10 seconds and dried by dryair for one minute. this method of cleaning used to remove all contaminated layerformed on the alloy during storage (21). the artificial saliva was replaced every 7 days with a fresh solution to avoid its saturation with the corrosion products (22,23). the chlorhexidine solution was used according to the manufacturer instruction and the samples were immersed completely in the solution in the test tubes and covered perfectly by theirs covers, shake by the shaker for 1 minute, then they were removed and washed with distilled water, dried by dry air and re-put in the artificial saliva, then incubated at 370c. this procedure would be repeated 2 times daily for (1day, 7 days, and 28 days) intervals (20). the samples of the toothpaste groups were immersed completely in the paste on a slap for 2minutesafter the 2 minutes were completed successfully the wires were removed and washed with distilled water, dried by dry air water and reput in the artificial saliva, then incubated at 37 0c. this procedure would be repeated 3 times daily for (1day, 7 days, and 28 days) intervals (20). figure 1: atomic force microscope (afm). statistical analysis data collected analyzed by using relevant software statistical package of social science (spss, chicago, 21). these data of the corrosion pits for all specimens averaged, and the results analyzed with the following statistics: 1. descriptive statistics :( mean of corrosion pits and its standard deviation). 2. inferential statistics: {independent sample ttest, one way analysis of variance (anova) and least significant difference (lsd)}. results the effect of coating material: dependent sample of t-test showed nonsignificant coating type difference in the corrosion pits in dry environment at different intervals and when the wires were immersed in chlorhexidine for 1 day and in the toothpaste for 1 day and 7 days. on the other hand, there was highly significant difference when the wires immersed in the remaining media at different intervals (table 1). j bagh college dentistry vol. 28(1), march 2016 an evaluation of pedodontics, orthodontics and preventive dentistry 155 the effect of the immersion media: analysis of variance difference (anova) has demonstrated a non-significant difference among the media at the first day of immersion of the two wire’s type but showed a highly significant difference at 28 days. on the other hand, it revealed a highly significant media effect difference of hubit and a non-significant difference of orthotechnology at 7 days immersion period (table 2). the effect of the time intervals: the time interval has non-significant effect on the corrosion pits at dry environment. analysis of variance difference (anova) has demonstrated highly significant differences among the different intervals in wet environment except that for epoxy coated stainless steel at chlorhexidine (table 3). table 1: the effect of coating material difference for each wire immersed in specific media for different intervals. media intervals descriptive statistics company difference (d.f.=18) hubit orthotechnology mean pits/ nm s.d. mean pits/ nm s.d. mean difference t-test p-value dry 1 day 0.000375 0.000196 0.00039 0.000229 -0.000015 -0.158 0.876 7 days 0.000401 0.000201 0.000351 0.000175 0.000050 0.594 0.560 28 days 0.000355 0.000166 0.000364 0.000228 -0.000009 -0.101 0.921 artificial saliva 1 day 0.000403 0.000096 0.000289 0.000071 0.000114 3.029 *0.007 7 days 0.000560 0.000045 0.000297 0.000069 0.000263 10.068 *0.000 28 days 0.001020 0.000239 0.000535 0.000114 0.000485 5.789 *0.000 chx 1 day 0.000326 0.000171 0.000320 0.000067 0.000006 0.103 0.919 7 days 0.000226 0.000043 0.000321 0.000058 -0.000095 -4.143 *0.001 28 days 0.001285 0.000149 0.000298 0.000105 0.000987 17.129 *0.000 tooth paste 1 day 0.000379 0.000110 0.000396 0.000159 -0.000017 -0.279 0.784 7 days 0.000267 0.000082 0.000292 0.000027 -0.000025 -0.922 0.369 28 days 0.001290 0.000039 0.000743 0.000126 0.000547 13.096 *0.000 (*) mean highly significant table 2: the effect of different media on the corrosion pits of different wires and intervals. company intervals descriptive statistics media difference (d.f.=39) dry artificial saliva chlorhexidine tooth paste mean pits/ nm s.d. mean pits/ nm s.d. mean pits/ nm s.d. mean pits/ nm s.d. f-test p-value hubit 1 day 0.000375 0.000196 0.000403 0.000096 0.000326 0.000171 0.000379 0.000110 0.471 0.705 7 days 0.000401 0.000201 0.000560 0.000045 0.000226 0.000043 0.000267 0.000082 17.858 *0.000 28 days 0.000355 0.000166 0.001020 0.000239 0.001285 0.000149 0.001290 0.000039 71.677 *0.000 ortho technology 1 day 0.000390 0.000229 0.000289 0.000071 0.000320 0.000067 0.000396 0.000159 1.277 0.297 7 days 0.000351 0.000175 0.000297 0.000069 0.000321 0.000058 0.000292 0.000027 0.739 0.536 28 days 0.000364 0.000228 0.000535 0.000114 0.000298 0.000105 0.000743 0.000126 17.210 *0.000 (*) mean highly significant table 3: the effect of time of immersion in each media for each wire. media company descriptive statistics intervals difference (d.f.=29) 1 day 7 days 28 days mean pits/ nm s.d. mean pits/ nm s.d. mean pits/ nm s.d. f-test p-value dry hubit 0.000375 0.000196 0.000401 0.000201 0.000355 0.000166 0.150 0.861 orthotechnology 0.00039 0.000229 0.000351 0.000175 0.000364 0.000228 0.088 0.916 artificial saliva hubit 0.000403 0.000096 0.000560 0.000045 0.001020 0.000239 45.200 *0.000 orthotechnology 0.000289 0.000071 0.000297 0.000069 0.000535 0.000114 25.564 *0.000 chx hubit 0.000326 0.00017 0.000226 0.000043 0.001285 0.000149 193.129 *0.000 orthotechnology 0.000320 0.000067 0.000321 0.000058 0.000298 0.000105 0.266 0.768 tooth paste hubit 0.000379 0.000110 0.000267 0.000082 0.001290 0.000039 467.830 *0.000 orthotechnology 0.000396 0.000159 0.000292 0.000027 0.000743 0.000126 39.962 *0.000 (*) mean highly significant j bagh college dentistry vol. 28(1), march 2016 an evaluation of pedodontics, orthodontics and preventive dentistry 156 discussion the effect of coating material the non-significant coating type difference in the corrosion pits in dry environment, in chlorhexidine for 1 day and in the toothpaste for 1 day and 7 days may be due to the presence of the protective oxide layer. on the other hand, the highly significant difference when the wires were immersed in the artificial saliva media at different intervals may be attributed to the fact the teflon coating layer adds a minimal thickness to the archwires while epoxy coating dose add a more significant thickness. this result agreed with da silvaa et al. (24) and khamees (25). the effect of the immersion media the highly significant difference among the media at 28 days of immersion of the two types of wiremay related to some factor or factors that are able to modify the properties of the wires, such as the ph level, wet condition, thickness of coating, the composition of coating and the temperature. on the other hand, the result revealed a highly significant media effect difference of hubit and a non-significant difference of orthotechnology at 7 days immersion period.the finding of this study disagreed with neumann et al. (26) study in which they found teflon coating (hubit) prevented the corrosion of the wire completely. the effect of the time intervals the time interval has no effect on the corrosion pits at dry environment. this may related to the constant factors of the environment at this study. thehighly significant differences among the different intervals at wet environment for the teflon coated stainless steel wires (hubit) may be due to rapture of the protective layer. this result agree with al-najafy (27) who found that the surface roughness of teflon coated stainless increased with increased immersion time.the finding of this study disagree with neumann et al.(26) study. this study also showed non-significant effect of the immersion time for epoxy coated stainless steel at chlorhexidine. this may be due to the type, nature and thickness of coating material, which need more time to corrode. references 1. walton dk, fields hw, johnston wm, rosenstiel sf, firestone ar, christensen jc. orthodontic appliance preferences of children and adolescents. am j orthod dentofac orthop 2010; 138(6):698.e1-12; discussion 698-9. 2. jeremiah hg, bister d, newton jt. social perceptions of adults wearing orthodontic appliances: a crosssectional study. eur j orthod 2011; 33(5):476-82. 3. elayyan f, silikas n, bearn d. ex vivo surface and mechanical properties of coated orthodontic archwires. eur j orthod 2008; 30(6): 661-7. 4. elayyan f, silikas n, bearn d. mechanical properties of coated superelastic archwires in conventional and self-ligating orthodontic brackets. am j orthod dentofac orthop 2010; 137(2):213–7. 5. aksakalli s, malkoc s. esthetic orthodontic archwires: literature review. j orthod res 2013; 1: 2-4. 6. proffit wr, fields hw, sarver dm. contemporary orthodontics. 5th ed. st louis: mosby; 2013. 7. redlich m, katz a, rapoport l, wagner h, feldman y, tenne r. improved orthodontic stainless steel wires coated with inorganic fullerene-like nanoparticles of ws (2) impregnated in electroless nickel-phosphorous film. dent mater j 2008; 24: 1640-6. 8. burstone cj, liebler sa, goldberg aj. polyphenylene polymers as esthetic orthodontic archwires. am j orthod dentofac orthop 2011; 139(4 suppl):e391-8. 9. quintão cc, cal-neto jp, menezes lm, elias cn. force-deflection properties of initial orthodontic archwires. world j orthod 2009; 10(1):29-32. 10. kaphoor aa, sundareswaran s. aesthetic nickel titanium wires—how much do they deliver? eur j orthod 2012; 34(5): 603-9. 11. arango s, peláez-vargas a, garcía c. coating and surface treatments on orthodontic metallic materials. coatings 2013; 3(1):1-15. 12. eliades t. orthodontic materials research and applications: part 2. current status and projected future developments in materials and biocompatibility. am j orthod dentofac orthop 2007; 131(2):253-62 13. anusavice kj, shen c, rawls hr. phillip’s science of dental materials. 12th ed. st. louis: elsevier saunders; 2012. 14. kusy rp. a review of contemporary archwires: their properties and characteristics. angle orthod 1997; 67(3):197-207. 15. regis s jr, soares p, camargo es, guarizafilho o, tanaka o, maruo h. biodegradation of orthodontic metallic brackets and associated implications for friction. am j orthod dentofac orthop 2011; 140(4):501-9. 16. hafez hs, selim em, kameleid fh, tawfik wa, alashkar ea, mostafa ya. cytotoxicity, genotoxicity, and metal release in patients with fixed orthodontic appliances: a longitudinal in-vivo study. am j orthod dentofac orthop 2011; 140(3):298-308. 17. mikulewicz m, chojnacka k, woźniak b, downarowicz p. release of metal ions from orthodontic appliances: an in vitro study. biol trace elem res.2012 may; 146(2):272-80. 18. faverani lp, barao va, pires mf, yuan jc, sukotjo c, mathew mt, assunção wg.corrosion kinetics and topography analysis of ti-6al-4v alloy subjected to different mouthwash solutions. mater scieng c mater biol appl 2014; 43:1-10. 19. jaber lc, rodrigues ja, amaral fl, frança fm, basting rt, turssi cp. degradation of orthodontic wires under simulated cariogenic and erosive condition. braz oral res2014;28(1) j bagh college dentistry vol. 28(1), march 2016 an evaluation of pedodontics, orthodontics and preventive dentistry 157 20. sultanz. measurements of depth and number of corrosion pits in some types of orthodontic wires (an in vitro study). a master thesis, department of pop, college of dentistry, university of mosul, 2008. 21. oh kt, kim kn. ion release and cytotoxicity of stainless steel wires. eur j orthod 2005; 533–40 22. elshahawy w, watanabe i, koike m. elemental ion release from four different fixed prosthodontic materials. dent mater 2009; 25(8): 976-81. 23. khamees a. comparison of metal ions release and corrosion potential from different bracket archwire combinations (an in vitro study). a master thesis, orthodontic department, college of dentistry, university of baghdad, 2013. 24. dasilvaa dl, mattos ct, simão ra, de oliveira ruellas ac. coating stability and surface characteristics of esthetic orthodontic coated archwires. angle orthod 2013; 83(6): 994-1001 25. khamees a. comparison of metal ions release and corrosion potential from different bracket archwire combinations (an in vitro study). a master thesis, orthodontics department, college of dentistry, university of baghdad, 2013. 26. neumann p, bourauel c, jäger a. corrosion and permanent fracture resistance of coated and conventional orthodontic wires. j mater sci mater med. 2002; 13(2):141-7. 27. al-najafy z. the effect of artificial saliva on the surface roughness of orthodontic arch wire materials (an in vitro study). a master thesis, department of pop, college of dentistry, university of mosul, 2006. abdulkareem f.docx j bagh college dentistry vol. 28(2), june 2016 an evaluation of restorative dentistry 1 an evaluation of gutta-percha penetration depth into simulated lateral canals by using three different obturation techniques (a comparative study) mohammad qasim mohammad, b.d.s. (1) abdul-karim j. al-azzawi, b.d.s., m.sc. (2) abstract background:sthe aims of this study were to evaluate and compare the ability of three different techniques to obdurate simulated lateral canals, evaluate the effect of the main canal curvature on obturation of lateral canals and compare the gutta-percha penetration between coronal and apical lateral canals. materials and methods: resin blocks with 30 straight and 30 curved were used in this study. each canal has two parallel lateral canals. the main canal has 0.3 mm apical diameter and 0.04 taper. the canals were divided into six groups according to canal curvature and obturation techniques used (n=10): groups c1 and c2: straight and curved canals obturated with continuous wave technique using e&q mastertm system. groups o1 and o2: straight and curved canals obturated with obtura ii. groups t1 and t2: straight and curved canals obturated with thermafil obturators. soapy water was used to simulate sealer in all obturations performed. the depth of gutta-percha penetration into lateral canals was measured using computerized stereomicroscope. results: there were very highly significant differences between the obturation techniques at each lateral canal level in both straight and curved canals. continuous wave using e&q mastertm system exhibited the greatest guttapercha penetration into lateral canals with very highly significant difference from both other techniques at majority of lateral canals. there was nonsignificant difference between thermafil and obtura ii except at coronal lateral canal of straight main canals where the difference was very highly significant. the gutta-percha depth was greater in coronal than apical lateral canals in all groups of both straight and curved canals, and gutta-percha depth was greater in straight than in curved canals within each obturation technique. conclusion: this study showed that all the three obturation techniques used were able to obturate simulated lateral canals with the continuous wave technique being the best. gutta-percha depth was less in the apical than the coronal lateral canals. canal curvature can influence the gutta-percha depth. key words: obturation, lateral canal, thermafil. (j bagh coll dentistry 2016; 28(2):1-6). introduction lateral canals are difficult to instrument and to irrigate during endodontic therapy and may allow bacterial growth. persisting bacteria in teeth endodontically treated may be located in uninstrumented areas like lateral canals (1). these lateral canals can establish connection between the main root canal and periodontal ligament, as well as the apical foramen (2). so that, the threedimensional obturation of the root canal system becomes extremely important, as it could prevent re-infection and isolate microorganisms in inaccessible areas, without access to space and nutrients (1). gutta-percha in combination with a root canal sealer is the most commonly used filling material. the sealer fills the minor irregularities and acts as a lute between the gutta-percha and canal wall. some sealers shrink upon setting, whilst others are susceptible to decomposition (3). the amount of sealer should be restricted to a thin layer between the gutta-percha and the walls of the canal (4), but it should be sufficient to restrict the passage of microorganisms and their by-products that are responsible for periradicular disease (5). (1)master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. vertical compaction of warm gutta-percha can produce a threedimensional obturation of the root canal space and, with extraordinary frequency, also results in the filling of lateral of lateral canals and better outcomes in treatments using warm guttapercha (3). the curvature of the main canal has an influencing effect on the quality of obturation. when the curvature of the main canals reaches about 25°, it can greatly reduce the ability of some obturation techniques to obturate lateral canals; however other techniques may be reduced to lesser extent or even not affected (6). because of the introduction of the vertical compaction of warm gutta-percha, many thermoplasticized procedures, and devices have been used to improve the three-dimensional sealing of the root canal space (7). previous studies, comparing the effectiveness of filling techniques, have given conflicting results. some reported that none of the techniques studied provided a superior seal whilst other studies reported better filling (8). materials and methods sample preparation eight thermafil training blocks each with four simulated main canals were selected. two parallel lateral canals, with nominal diameter of 0.5 mm, j bagh college dentistry vol. 28(2), june 2016 an evaluation of restorative dentistry 2 branched from each main canal, at right angles from the main canal axis. the most apical canal at 5 mm from the apical end of the main canal was labelled (a); the coronal canal was a further 6.5 mm more coronal than (a) and was labelled (c) (figure 1). figure 1: the clear block with simulated curved root canals both lateral canals consisted of three cylindric sections the inner section had a diameter of 0.5 mm, and length 0.2 mm (a) and 1 mm (c); the middle section had a diameter of 0.7 mm, and length 1 mm (a) and 1 mm (c); the outer section had a diameter of 1 mm. the length of each main canal was 18 mm from the surface of the resin block, its diameter at the orifice (3 mm from the surface of the resin block) was 1 mm, its diameter at the end point was 0.3 mm and its taper was 0.04 and the curvature was 25° (3). these blocks were cut in two parts horizontally for ease of manipulation and to facilitate sample grouping resulted in 16 blocks with two main canals. only 15 blocks were used in the present study. the total number of simulated curved main canals used was 30 canals. fifteen custom made blocks with two straight main canals were fabricated with the same dimension and taper of thermafil training block but with straight canal. the total number of simulated straight main canals used was 30 canals. computerized turnery machine was used to fabricate straight metal pins with terminal diameter of 0.3 mm and taper 0.04. figure 3: custom made block. these metal pins were inserted into a block of wax. laboratory procedure (flasking, wax elimination and packing) was done to convert the wax into heat cured clear acrylic. then high accuracy stand drill was used to prepare two lateral canals with the same dimensions and at the same locations from the apical end of the main canal to those of ready-made thermafil training block. the patency of all main and lateral canals was verified using a size 20 stainless steel k-file. each canal was irrigated with 5ml of distilled water and then dried with #30 paper points (3). to avoid bias, all blocks were covered with sticker tape, so that the operator could not see the canal while performing obturation and all obturations were made by the same operator blindly simulating clinical situation. sample grouping all 30 curved canals and 30 straight canals were divided into 6 groups(ten each) according to the method of obturation as shown in table 1: table 1: grouping of samples. figure 2: dimensions of lateral canal j bagh college dentistry vol. 28(2), june 2016 an evaluation of restorative dentistry 3 number of groups method of obturation type of canal c1 continuous wave with e&q master straight c2 curved o1 obtura ii straight o2 curved t1 thermafil straight t2 curved sealer application all canal surfaces were coated with a thin layer of liquid soap to simulate sealer cement. liquid soap was applied by coating the canal walls using k-file #30. the liquid soap was used to lubricate the main canal walls without blocking the lateral canals and without masking off the filling material (8). canals obturation groups c1 and c2 continuous wave technique of obturation using e&q master cordless gutta-percha obturator (pen and gun) was used to obturate all the 20 canals of these two groups according to manufacturer's instructions. the technique includes two steps, first step is downpack and second step is backfill. 1down pack. before using liquid soap into straight (group c1) and curved (group c2) canals, the master gutta-percha cone #30 and taper 0.04 was tested to full working length in the canals to be sure it goes fully to place. the cone is then removed and the corresponding finger plugger #40 was tried for size in the canal to check its "binding-point", the stopper attachment is then adjusted at the coronal surface of the block and the plugger is removed. the pen tip was also tested to be inserted into the canal and reach 5 mm from apical end of the canal. liquid soap is applied. the master guttapercha cone was inserted to full working length and the pen was activated to heat the pen tip and used to sear off the cone at canal orifice. the preheated pen tip was then driven smoothly through the gutta-percha to within 3 to 4 mm of its binding point in the canal. this took about 2 seconds. maintaining apical pressure, the pen tip continued to move apically, and at that time the heat switch was released. the pen tip was held there, cooled, under sustained pressure, for an additional 10 seconds. during that period the gutta-percha flowed into lateral canals. the pressure also compensated for the shrinkage that might occur as the mass cools. to remove the pen tip, while still maintaining apical pressure, the heat switch was activated for only 1 second followed by a 1 second pause, the cold pen tip was then quickly withdrawn. finger plugger was used to compact gutta-percha apically. apical 5 mm at that stage was obturated and remainder of the canal was ready for backfill. 2backfill at this step, the gun was switched on, loaded with gutta-percha pellet and set at temperature 200°c. a small amount of gutta-percha was extruded to warm the gun needle and discarded. the gun needle was then quickly introduced into the canal. the trigger of the gutta-percha gun was activated and thermoplasticized guttapercha extruded into the canal, gently pushing the needle out. three increments were applied to backfill the canals as follows: 5, 5, 3 mm. once the canal was filled conventional hand plugger was used to compact the gutta-percha (8,9). figure 4: backfilling with e&q master system groups o1 and o2 samples of these two groups were obturated using obtura ii with 23-g needle using the same type of gutta-percha pellets that used in groups c1 and c2. the obtura ii device was switched on, the temperature was set at 200°c and the guttapercha pellets were loaded into the gun. the liquid soap was inserted into the canals using kfile #30, and a small amount of gutta-percha was extruded to heat the needle and discarded. the needle was inserted into the canal within 5 mm from the apical end and the trigger was pressed to release gutta-percha into the canal until gently pushing the needle out. the needle was removed from the canal and a finger plugger #40 was used to compact the gutta-percha apically and to compensate for cooling shrinkage. four increments were used to fill the canal as following: 5, 5, 5, 3 mm in sequence with compaction between increments using finger plugger after first increment and hand plugger after the others (8,10). figure 5: obtura injecting soft gutta percha j bagh college dentistry vol. 28(2), june 2016 an evaluation of restorative dentistry 4 groups t1 and t2 in these two groups, the samples were obturated with plastic carrier-based thermafil obturators #30 according to the manufacturer's instructions. size 30 verifier was inserted into the canal to the working length to check the ability to reach full working length. the stopper was placed on the thermafil cone according to the working length and the cone #30 was placed in one of the heating chamber of thermaprep plus oven (size 30-60 button is chosen). the heating time needed to heat gutta-percha obturators was regulated automatically by the thermaprep plus oven (about 15 seconds); during this time liquid soap was introduced into the canal by coating the canal walls using k-file #30. after a beep sound, the oven was switched off then the cone raised and inserted inside the canal firmly and slowly to working length without any twisting or rotation and light apical pressure was maintained to overcome cooling shrinkage. the handle of the obturator was cut and removed after the gutta-percha cooled by inverted cone bur in a high speed handpiece (11). figure 6: thermafil system data collection after the completion of obturation of all blocks, each block was examined at an original magnification of 10x by means of stereomicroscope and photographed by digital camera at special settings as recommended by the manufactures mounted on the stereomicroscope (motic, gloucester road causeway bay, hong kong). the obtained digital images were captured with built-in digital camera at a resolution of 1024x768 pixels and stored using ibm computer (ibm corporation, armok, new york). motic images plus 2.0 software (motic, gloucester road causeway bay, hong kong) that is supported with the stereomicroscope by the manufacturer was used to measure the distance from the wall of the main canal to the most far point that guttapercha had entered into lateral canals. all measures made and readings were taken by the same trained examiner. results the collected data were analyzed by descriptive statistics including minimum, maximum, means and standard deviation in millimeter for each group of obturation used in the study as shown in table 1. table 1: descriptive statistical analysis. table (1) shows that in straight canals, the highest mean value for gutta-percha penetration was seen in continuous wave at coronal lc (5.926 mm) followed by thermafil at coronal lc (4.467 mm), obtura ii at coronal lc (3.679 mm), continuous wave at apical lc (2.884 mm), obtura ii at apical lc (2.358 mm) and the least was thermafil at apical lc (1.993 mm). j bagh college dentistry vol. 28(2), june 2016 an evaluation of restorative dentistry 5 in curved canals, the highest mean value for gutta-percha penetration was seen in continuous wave at coronal lc (4.306 mm) followed by obtura ii at coronal lc (3.027 mm), thermafil at coronal lc (2.947 mm), continuous wave at apical lc (2.837 mm), thermafil at apical lc (1.366 mm) and the least was obtura ii at apical lc (1.148 mm). the overall highest mean value was seen in continuous wave of straight canals at coronal lc (5.926 mm) and the least mean value was seen in obtura ii of curved canals at apical lc (1.148 mm). the results of least significance difference test (lsd) showed the following: 1. there was statistically highly significant difference between group c1 and group t1, and between group c1 and group o1 at coronal lc, and between group c1 and group t1 at apical lc. 2. there was significant difference between group c1 and group o1 at apical lc. 3. there was highly significant difference between group c2 and group t2, and between group c2 and group o2 at both coronal and apical lc. 4. there was highly significant difference between o1 and t1 at coronal lc. 5. there difference was non-significant between o1 and t1 at apical lc. 6. there difference was nonsignificant between o2 and t2 at both coronal and apical lc. table 2: lsd test for gutta percha penetration among the three obturation techniques in different main canal types at each level. an explanation for these results might be attributed to that in continuous wave technique at downpack phase, because of the tapered pen tip the gutta-percha was compacted laterally as well as vertically. this would force the gutta-percha deeper into lc (3). also the master cone provided sufficient amount of gutta-percha that penetrated into lc as compared with thermafil technique in which plastic carrier comprise part of the obturator mass especially at apical lc. the results showed that in straight main canals at coronal lc group t1 had greater mean guttapercha depth value compared with group o1 and the difference was statistically highly significant. at apical lc there was non-significant difference between group o1 and group t1 techniques. this might be attributed to that the plastic carrier of thermafil obturator provides lateral compaction that pushed gutta-percha into lc. in curved main canals, the results showed that the mean value of gutta-percha penetration depth was better in group o2 than in group t2 at coronal lc; while at apical lc it was higher in group t2 than in group o2; however, there was non-significant difference between group o2 and group t2 at both coronal and apical lc. as conclusion, 1. all thermoplasticized gutta-percha obturation techniques used in the present study had the ability to obturate lateral canals. 2. continuous wave obturation technique was better in obturation of lateral canals than obtura ii and thermafil in both straight and curved main canals. 3. location of lateral canal could influence its ability to be obturated. coronal lateral canals were much easier to obturate than apical lateral canals of both straight and curved main canals in all obturation techniques used. 4. straight root canals allowed greater ability to obturate lateral canals than curved root canals, regardless of the obturation technique used. j bagh college dentistry vol. 28(2), june 2016 an evaluation of restorative dentistry 6 references 1carvalho-sousa b, almeida-gomes f, borba carvalho pr, maníglia-ferreira c, gurgel-filho ed,albuquerqued ds. filling lateral canals: evaluation of different filling techniques. eur j dent 2010; 4(3): 251–6. 2almeida j, gomes b, ferraz c, souza-filho f, zaia a. filling of artificial lateral canals and microleakage and flow of five endodontic sealers. int endod j 2007; 40: 692–9. 3venturi m, di lenarda r and breschi l. an ex vivo comparison of three different gutta-percha cones when compacted at different temperatures: rheological considerations in relation to the filling of lateral canals. int endod j 2006; 39: 648–56. 4wu mk, ozok ar, wesselink pr. sealer distribution in root canals obturated by three techniques. int end j 2000; 33: 340–5. 5gutmann j l and witherspoon d e. obturation of the cleaned and shaped root canal system. in: cohen s and burns r c (eds) pathways of the pulp. 8thed. st. louis, london: mosby; 2002, pp: 293–364. 6goldberg f, artaza lp, de silvio a. effectiveness of different obturation techniques in the filling of simulated lateral canals. j endod 2001; 27: 362–4. 7leung sf, gulabivala k. an in-vitro evaluation of the influence of canal curvature on the sealing ability of thermafil. int endod j, 1994; 27: 190–6. 8karabucak b, kim a, chen v, iqbal m k. the comparison of gutta-percha and resilon penetration into lateral canals with different thermoplastic delivery systems. j endod 2008; 34: 847–9. 9carrotte p. endodontics: part 8 filling the root canal system. br dent j 2004; 197(11): 667–72. 10ingle ji, newton cw, west jd, gutmann jl, glickman gn, korzon bh, martin h. obturation of the radicular space. in: ingle j i and bakland l k (eds) endodontics. 5thed.london bc decker inc.; 2002. pp. 571–668. 11gençoğlu n, oruçoğlu h, helvacıoğlu d. apical leakage of different gutta-percha techniques: thermafil, js quick-fill, soft core, microseal, system b and lateral condensation with a computerized fluid filtration meter. eur j dent 2007; 1(2): 97–103. abdalbasit.doc j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 1 teeth displacement and palatal adaptation of autoclave cured acrylic resin with various palates and investments. abdalbasit a fatihallah, b.d.s., m.sc., ph.d. (1) rola w.a, b.d.s., m.sc. (2) ali n.a, b.d.s., m.sc. (2) abstract background: the denture base inaccuracies during processing negatively influence the retention and stability of finished complete denture. the aims of this study were to evaluate teeth movement and palatal adaptation of autoclave cured denture bases and their relationship with palatal depths and investments. materials and methods: a nightly maxillary complete dentures prepared, processed and organized to be tested as follows: 1. processing methods: water bath and autoclave with both fast and slow cycles. 2. palatal depth: shallow, medium and deep. 3. investing medium: stone and silicone. for every finished denture, two measurements were done: first: teeth movement by attaching metallic reference screws on the right and left centrals, first premolars and second molars. second: palatal adaptation by sectioning the posterior part of the denture and measuring the distances between five selected points which were on the right and left: ridge crest, center of the vestibule and middle of the palate. then two measurements were done before and after curing by using travelling microscope of 0.001% of accuracy. the collected data organized statistically by three ways analysis of variance for curing methods, investments and palatal depth. also, least significant test and t test for detection of difference. results: high significant improvements in dimensional stability shows when autoclave was used compared with the water bath. results show that autoclave curing reduces the amount of teeth movements and improves palatal adaptation with silicone investment compared with stone. conclusions: resin curing by autoclave is a better alternative to water bath. the dimensional stability were improved especially when silicone were used instead of stone. key words: teeth movements, palatal adaptation, silicone investment, travelling microscope. (j bagh coll dentistry 2016; 28(1):1-10). introduction the polymers subjected to curing expansion during heating and both types of thermal shrinkages (curing and cooling), so higher molecular weight polymers will be polymerized immediately leading to those areas of less polymerization move toward areas of higher one and creating stress which in turn leads to dimensional changes in the cured dentures. (1,2) palatal configuration of maxillary arch and particularly the deep one plays vital role in the dimensional stability of the upper complete dentures especially the adaptation to the underlying mucosa, so poor palatal seal leads to instability and poor retention of the dental prosthesis. (3) especially in the posterior part where least resistant points because it lies in thin and weak sections leading to more stress relaxation and more inaccuracies. (4) when acrylic were cured, the dimensional changes after curing in addition with a multiple distortions when flasks is allowed to cool and then opened resulted in inaccuracies leading to horizontal and even vertical teeth displacements and errors, ends with changes in occlusal patterns. (5) the silicone increasingly regarded as a successful alternative to hard stone as investment especially when accuracy is regarded. (6) (1) assistant professor, department of prosthodontics. college of dentistry, university of baghdad. (2) lecturer, department of prosthodontics. college of dentistry, university of baghdad. the benefits were; easily and cleanly flasking, free from any opportunity of denture warp page after de-flasking. however, the relationship between investment materials and teeth displacement and palatal adaptation need further investigations. (7) heat curing of acrylic resin considered the best method, and provides a lot of advantages including simple technique with cheap devices. although it had many disadvantages especially long curing time. (8) the better curing is the fast one, and the studies indicated that the fast method is suitable for denture bases with multiple sizes, shapes and palatal configurations. (9) autoclave curing depends on elevating water temperature more than 100°c in an evacuated chamber, so raising the pressure inside it. (10) its fast and slow cycles achieves better results in the mechanical properties when compared with the water bath. (11) the measurements of teeth movements and palatal adaptation were done by the use of travelling microscope to record minor inaccuracies. (4) the purpose of the present research was to determine teeth movement and palatal adaptation of acrylic resins with multiple palatal depths (shallow, medium and deep) cured by (water bath and fast and slow autoclave cycles) with two investments (stone and silicone). j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 2 materials and methods a metal maxillary edentulous brass cast (standardized, new york, usa) were selected to make a silicon master mold (columbia dent form corp.). a three palatal depths (shallow, medium and deep) were obtained by addition of wax layers (shanghai new century dental material, china) to the palate of silicone mold and so the mold without addition represent the shallow. while the medium depth had a palatal depth of (13mm). on the other hand, the deep palatal depth were 18mm. (12) after that, type iv stone (elite model, zhermack technical, italy) of 100gm/30ml poured inside these molds by using vibrator (quayle dental, england) and remained setting for 45min before getting the casts. the depth of the palate were estimated by cast fixation to the surveyor (milling machine, af30, switzerland) with a zero tilting, then half circular ruler (china plastic industry) placed on the ridge. after that, digital vernia (shanghai shenhanme asuringtools co., ltd, china) touches the ruler and refer to palatal center at the point of union between incisive papilla and fovea palatine uniting line. (12) then, 90 stone casts were duplicated by using plastic flask (clear cast flask, vertex, netherlands) by attaching them to the lower half with melted wax, then the upper half connected to the base. later, the agar (castagel, vertexdental, netherlands) were liquefied in a water bath (ewl 55 01, west germany) at (92ºc) followed by tempering at (48ºc) to fill the flask completely and allowed to solidify for one hour. (13) after that, the cast was removed and the created mold was poured with type iv stone. these steps were repeated until the intended number of casts were made. as illustrated in figure 1. figure 1: the parts of the plastic duplication flask which were used for cast duplication. biostar device (schu-dental, germany) were used for construction of clear thermoplastic cakes (biocryl c, scheu-dental, iserlohn, germany) in order to make 2mm thickness record bases for all the casts and palatal depths depending on manufacturer recommendations. (14) when the intended record bases completed, occlusal rims were made by attaching bite rim wax with standard measurement of 22 mm and 18mm for length anteriorly and posteriorly and 4mm and 7mm for width respectively. (15) conventional mounting procedure were used to attach the maxillary cast to the upper member of a semi adjustable articulator (model h2, hanau eng. co. buffalo, new york, and usa). the articulator parameters were: the tip of bonwill triangle were equilibrated with the central area of the record base at the incisal area, to orient the cast accurately in the anterior-posterior plane. then the incisal pins were oriented according to the record base midline and fixed at zero degree. finally, the condylar track and bennett angles were sets at 30 and 10 degrees respectively. the mounting completed with the aid of a metal plate (china, brass) attached to the lower member of the articulator by metal screw and fixed in the mid distance between the two members, the articulator were closed in order to proximate the incisal pins to zero degree. (16) after that, an arbitrary face bow (dentatus, sweden) used to make orientation of occlusal plane by selection of two points posteriorly in the condylar area and one point anteriorly at the incisal pin. (16) then the arrangement of acrylic teeth (florident, cross linked, shade no.3, china) were done with the aid of a universal dentate silicone mold (columbia dent form corp., new york, usa). the teeth were placed in the teeth imprint of the mold and then melted wax was poured inside it to simulate the gingival contour of the waxed denture, the teeth with wax were carefully removed from the mold after wax solidification and then luted to the maxillary bite rims with the aid of hot spatula. (16) as illustrated in figure (2). figure 2: articulator with cast and arranged teeth fixed to the upper member while the metal plate attached to the lower one. for teeth movements, selected points were chosen on the teeth which were: 1. the center of the incisal edge of the right and left central incisors (ri&li). j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 3 2. the buccal cusps of the right and left first premolars (rp&lp). 3. the mesio buccal cusps of the right and left second molars (rm&lm). then, metallic reference screws (dentsplymaillefer, swiss) with 3mm length and 2mm diameter attached to these points after drilling a hole of 3mm depth with round carbide bur and plastic stopper to standardize drilling. fixation were by cyanoacrylate adhesive (cyanoacrylate adhesive material, japan ) and the distances between these points were standardized for all samples before acrylic resin curing and measured by travelling microscope as follows: a. mediolatral points include: 1. m-m (right to left molar). 2. p-p (right to left premolar). b.anteriposterior points which include: 3. rm-rp (right molar to right premolar). 4. rp-ri (right premolar to right incisor). 5. rm-ri (right molar to right incisor). 6. lm-lp (left molar to left premolar). 7. lp-li (left premolar to left incisor). 8. lm-li (left molar to left incisor). (16) as shown in figure (3, a). figure 3, a: the reference points for teeth movements. on the other hand, palatal adaptation of the internal surface of the acrylic resin and the external surface of the stone cast were estimated as follows: the length of the cast were measured as 52mm and the line of cutting were positioned at 39mm from the anterior border of the cast leaving 13mm to be cuts by using saw machine operated manually at a range of two transverse cuts for each seconds with continues water supply for cooling and the cast were separated in the area behind the second molar in front of the posterior palatal seal area and the selected points were measured by using the same travelling microscope in order to measure the space of separation at five previously selected areas which represents the right and left vestibules (rv&lv), the right and left crest of residual ridge (rc&lc) and finally the mid palatal area (m).(17) as illustrated in figure (4,b). figure 4, b: the reference point for posterior palatal adaptation. the distances before and after resin curing were measured and compared. the casts were arranged depending on the curing methods, in two major groups: the first one include 30 cast and cured with water bath, the second one include 60 cast cured with autoclave and include (30 cast for fast cycle and 30 for the slow one). each group contains 3 palatal depths; (shallow, medium and deep) with 10 casts for each, 5 casts invested with stone and 5 invested with silicone. casts were placed inside flask lower half (broden, sweden) by pouring type ii plaster (al-ahlya, iraq). after a setting of 45 min, a separating medium (swindon, england) painted and allowed for 5 min setting, then type iv stone were poured in the upper half of the flask around the waxed denture and allowed to set for 60 minutes. (16) same steps were followed when using silicone investment so the base and catalyst of silicon (castasil 21, vertex-dental, netherlands) in amount of 200ml were uniformly mixed in plastic bowl according to manufacturer instructions, and silicone were placed in the upper half of the flask, and allowed to set in 20 minutes. (18) during wax elimination, the flasks were placed inside 100c◦ water for about 5 minutes. after that the casts and teeth were flushed with 100c◦water and soup and then allowed to dry before the separating medium were applied to the two portions of the flask except the teeth ridge lap. (16) resin base (regular, tm, vertex-dental, netherlands) with p/l of 1:3 were mixed in mixing jar by stiff spatula for a half minutes and covered with glass slap for 15 minutes to reach dough stage. then it packed with a pressure of 20 bars. acrylic access were removed with wax knife and then placed under a hydraulic press (bremer goldschlagerei wilh, m lc rc lv rv rm lm lp rp li ri a b j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 4 herbst west germany) with 1250 kgf for 5 minutes and then clamed (ash co., england) and cured in water bath (digital water bath, labtech) for 1.5 hours at 73cº and then 30 minutes at 100ºc. (16) the autoclave curing were done with digital autoclave (euronda, type b inspection) by two curing cycles, fast and slow one. so the clamped flasks were seated inside the evacuation vessel and the door closed securely. curing done by choosing cycles stored in the machine memory. (19) and as illustrated in table (1). table 1: showing the curing cycles for the autoclave. digital control panel were used to monitor the progress of curing including: exchange of air with steam, elevation of temperature and maintaining it for sterilization and then reducing it at the end of the cycle, with again exchanging the steam with air. when the curing finished, the flasks were allowed for bench cooling at 23ºc, then the samples were deflasked and finished and polished according to the manufacturer recommendation. ada specification no.12 for samples storage were followed, so for teeth movements measurements were done immediately after deflasking,(16) for palatal adaptation, casts with their denture base were measured after storage in 20°c and 50% humidity in an incubator (bamb, galen, england).(20) statistical analysis of the distances before and after curing estimate the amount of dimensional changes as being positive or negative for expansion or contraction simultaneously. the data were according to tests applied; f-test applied for investing medium and curing methods with their relation with palatal depth. also t-test and lsd for relation between groups and subgroups at significance value of 0.05%. results the means in (mm) and standard deviations for teeth movements and palatal adaptation were presented in figures 5,6,7,8,9,10. the three way anova (f test) for palatal depth interference with investment materials and curing methods shows a high significant differences (p-value<0.01) for both teeth movements and palatal adaptation and these were showed in table 2. also the least significant test lsd for the comparison between each curing methods and palatal depth showed the following findings: water bath: silicone investment showed better dimensional accuracy than stone in teeth movement, while the stone were better than silicone in palatal adaptation. fast autoclave cycle: silicone showed better dimensional magnitude than stone in both teeth movement and palatal adaptation. slow autoclave cycle: stone were better than silicone in teeth movements. while for the palatal adaptation, the stone showed higher dimensional changes especially in medium palate when compared with the shallow one. while silicone showed better improvement when deep palate compared with the shallow one. as showed in table 3 and 4. curing methods: t-test for the differences between the control (water bath and stone investment) and (fast autoclave with both stone and silicone) revealed a high significant reduction (p-value<0.01) in teeth movements and palatal adaptation. while for the slow curing when compared with the control one, results revealed that the best reduction in dimensional changes was in silicone especially in palatal adaptation. on the other hand, when fast and slow curing were compared, results indicate significant decrease in the teeth movement when slow cycle and stone investment were used. also, the slow one proves better palatal adaptation, but when silicone investment was used. and these findings were shown in table 5. type of investment: t-test indicated that silicone investment have better dimensional stability than stone for all curing methods and all palatal depths. this was illustrated in table 6. fig. 5: bar chart shows the mean and standard deviations for both teeth movements when acrylic resin processed by water bath. no. curing cycle temperature pressure applied time 1 fast 121°c 210 kpa 15 minutes 2 slow 121°c 210 kpa 30 minutes j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 5 fig. 10: bar chart shows the mean and standard deviations for both palatal adaptation when acrylic resin processed by slow autoclave cycle. fig. 6: bar chart shows the mean and standard deviations for both palatal adaptation when acrylic resin processed by water bath. fig. 7: bar chart shows the mean and standard deviations for both teeth movements when acrylic resin processed by fast autoclave cycle. fig. 8: bar chart shows the mean and standard deviations for both palatal adaptation when acrylic resin processed by fast autoclave cycle. fig. 9: bar chart shows the mean and standard deviations for both teeth movements when acrylic resin processed by slow autoclave cycle j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 6 teeth movements points lsd (teeth movement) stone investment shallow&medium shallow&deep medium&deep sig ch sig ch sig ch wat er bath m-m hs § hs § hs § p-p hs § hs § hs § rm-rp hs § ns § hs § rp-ri hs £ hs £ hs § rm-ri hs § hs § ns £ lm-lp hs § ns § hs § lp-li hs £ hs £ hs § lm-li hs § ns § hs § fast cycle m-m hs § hs § hs § p-p ns § hs § hs § rm-rp hs § hs £ hs £ rp-ri hs § ns = hs § rm-ri hs § hs £ hs £ lm-lp hs § hs £ hs £ lp-li ns £ hs £ hs £ lm-li hs £ hs £ hs £ slow cycle m-m ns = hs £ hs £ p-p ns £ hs § hs £ rm-rp hs £ hs § hs £ rp-ri hs £ hs £ ns £ rm-ri hs £ hs § hs § lm-lp hs § hs § hs § lp-li hs £ hs § hs § lm-li hs £ hs § ns § palatal adaptation points lsd (palatal adaptation) shallow&medium shallow&deep medium&deep sig ch sig ch sig ch wat er bath rv ns = ns = ns = rc hs £ ns £ s § m ns = ns § ns § lc hs £ ns £ s § lv hs £ ns = hs § fast cycle rv hs £ hs £ ns = rc hs £ hs £ ns = m hs £ hs £ hs § lc hs £ ns £ s § lv hs £ hs £ hs § slow cycle rv hs £ hs £ ns £ rc ns £ hs £ hs £ m hs £ hs £ hs £ lc hs £ hs £ hs £ lv hs £ hs £ hs § teeth movements points f test shallow & medium &deep palate stone silicone f test sig f test sig water bath m-m 30.36 hs 50.03 hs p-p 12.32 hs 20.23 hs rm-rp 50.03 hs 30.03 hs rp-ri 15.03 hs 61.06 hs rm-ri 10.03 hs 15.023 hs lm-lp 89.23 hs 33.03 hs lp-li 50.02 hs 15.023 hs lm-li 19.03 hs 13.03 hs fast cycle m-m 61.03 hs 13.33 hs p-p 20.033 hs 13.03 hs rm-rp 48.3 hs 33.3 hs rp-ri 13.03 hs 48.3 hs rm-ri 42.06 hs 25.31 hs lm-lp 12.03 hs 48.03 hs lp-li 50.02 hs 33.33 hs lm-li 48.3 hs 82.2 hs slow cycle m-m 8.93 hs 66.03 hs p-p 22.43 hs 27.32 hs rm-rp 48.0 hs 10.04 hs rp-ri 32.34 hs 25.32 hs rm-ri 87.32 hs 13.03 hs lm-lp 61.03 hs 83.3 hs lp-li 15.03 hs 82.35 hs lm-li 10.32 hs 36.36 hs palatal adaptation points f test shallow & medium &deep palate stone silicone f test sig f test sig water bath rv 0.00 ns 0.00 ns rc 11.667 hsg 0.00 ns m 1.667 ns 56.00 ns lc 12.11 hs 0.00 ns lv 16.034 hs 0.00 ns fast cycle rv 4.033 hs 21.33 hs rc 16.26 hs 56.00 hs m 4.833 hs 42.667 hs lc 12.11 hs 21.333 hs lv 16.26 hs 40.03 hs slow cycle rv 15.36 hs 8.033 hs rc 8.033 hs 2.667 ns m 80.26 hs 8.033 hs lc 14.034 hs 0.00 ns lv 41.6 hs 0.00 ns table 2: the f test for comparison between curing methods and investments with palatal depths for both teeth movements and palatal adaptation. table 3: lsd test for the comparison between the curing methods and stone investment for palatal depths in teeth movements and palatal adaptation. j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 7 a a teeth movements points lsd (teeth movement) silicone investment shallow& medium shallow& deep medium& deep sig ch sig ch sig ch wate r bath m-m ns § ns § hs § p-p hs § hs § ns § rm-rp hs § hs § hs £ rp-ri hs £ hs § hs § rm-ri hs § hs £ hs £ lm-lp hs £ hs § hs § lp-li hs § hs £ hs £ lm-li hs § hs § ns £ fast cycle m-m ns = hs § hs § p-p hs § ns § hs £ rm-rp hs £ hs § hs § rp-ri hs § hs § hs £ rm-ri hs £ ns § hs § lm-lp hs £ hs § hs § lp-li hs £ hs £ hs £ lm-li hs £ hs § hs § slow cycle m-m hs £ hs £ hs § p-p hs £ hs £ hs £ rm-rp hs £ hs £ hs £ rp-ri hs £ hs £ ns £ rm-ri hs £ hs £ hs § lm-lp hs § ns § hs £ lp-li hs £ hs § hs § lm-li hs £ hs § hs § palatal adaptation points lsd (palatal adaptation) shallow& medium shallow& deep medium& deep sig ch sig ch sig ch wate r bath rv ns = ns = ns = rc ns = ns = ns = m hs § hs § ns £ lc ns = ns = ns = lv ns = ns = ns = fast cycle rv hs § hs § ns = rc hs £ ns £ hs § m hs § ns = hs £ lc hs £ ns § ns § lv ns = hs § hs § slow cycle rv ns = hs £ hs £ rc ns = ns £ ns £ m ns = hs £ hs £ lc ns = ns = ns = lv ns = ns = ns = teeth movement points t test control & fast cycle (teeth movement) stone silicone t test sig. ch. t test sig. ch. shallow m-m 22.33 s § 33.26 s § p-p 23.65 s § 31.25 s § rm-rp 12.56 s § 12.58 s § rp-ri 14.25 s £ 1.00 ns £ rm-ri 18.98 s § 30.78 s § lm-lp 24.28 s § 14.56 s § lp-li 20.87 s £ 17.29 s £ lm-li 1.00 ns £ 33.65 s § medium m-m 13.87 s § 17.25 s § p-p 1.00 ns £ 16.35 s § rm-rp 1.00 ns = 1.00 ns £ rp-ri 30.87 s £ 30.35 s § rm-ri 26.28 s £ 33.26 s § lm-lp 55.23 s § 12.35 s £ lp-li 14.12 s § 17.89 s § lm-li 17.89 s § 34.26 s § deep m-m 10.65 s § 27.36 s § p-p 1.00 s £ 1.00 ns = rm-rp 18.98 s § 17.089 s § rp-ri 15.36 s £ 13.25 s § rm-ri 17.58 s § 23.27 s § lm-lp 22.30 s £ 18.36 s § lp-li 27.47 s £ 62.38 s £ lm-li 30.56 s £ 66.98 s § palatal adaptation points t test control & fast cycle (palatal adaptation) stone silicone t test sig. ch. t test sig. ch. shallow rv 0 § 1.00 ns = rc 1.00 ns = 0 § m 0 § 1.00 ns = lc 0 = 0 £ lv 31.25 s § 1.00 ns = medium rv 1.00 ns = 23.28 s § rc 1.00 ns = 24.02 s § m 13.25 s £ 17.29 s § lc 1.00 ns = 23.56 s § lv 51.08 s § 17.36 s § deep rv 1.00 ns = 18.98 s § rc 45.06 s £ 58.36 s § m 30.25 s £ 30.25 s £ lc 1.00 ns = 60.08 s § lv 1.00 ns = 0 § table 4: lsd test for the comparison between the curing methods and sillicone investment for palatal depths in teeth table 5: t test for comparison between a:control and fast autoclave curing cycles, b: control and slow autoclave curing cycles, c: fast and slow autoclave curing cycles for palatal depths and investment materials. j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 8 b c teeth movement points t test control & slow cycle (teeth movement) stone silicone t test sig. ch. t test sig. ch. shallow m-m 12.35 s § 1.00 ns § p-p 1.00 ns = 30.35 s § rm-rp 74.25 s § 33.26 s § rp-ri 55.36 s £ 12.35 s £ rm-ri 25.36 s § 17.89 s § lm-lp 18.98 s £ 34.26 s £ lp-li 92.47 s £ 22.65 s £ lm-li 30.65 s £ 17.98 s § medium m-m 26.25 s § 26.25 s £ p-p 24.29 s § 24.29 s § rm-rp 19.30 s £ 19.30 s £ rp-ri 1.00 ns § 26.25 s § rm-ri 44.23 s £ 26.25 s £ lm-lp 47.56 s § 24.29 s § lp-li 24.32 s § 19.30 s § lm-li 18.90 s § 26.25 s § deep m-m 27.03 s § 27.36 s § p-p 15.09 s £ 1.00 ns = rm-rp 23.56 s § 30.78 s £ rp-ri 24.18 s £ 14.56 s £ rm-ri 19.65 s £ 17.29 s £ lm-lp 30.78 s £ 33.65 s § lp-li 1.00 ns = 1.00 ns = lm-li 16.23 s § 28.26 s § palatal adaptation points t test control & slow cycle (palatal adaptation) stone silicone t test sig. ch. t test sig. ch. shallow rv 17.56 s § 0 § rc 0 § 0 § m 30.08 s § 0 § lc 0 = 0 = lv 1.00 ns = 0 § medium rv 56.03 s £ 0 § rc 1.00 ns = 0 § m 1.00 ns = 0 § lc 40.08 s § 0 § lv 19.36 s £ 0 § deep rv 71.25 s £ 1.00 ns = rc 89.36 s £ 33.25 s § m 23.05 s £ 17.26 s £ lc 24.06 s £ 0 § lv 14.23 s £ 0 § teeth movement points t test fast & slow cycle (teeth movement) stone silicone t test sig. ch. t test sig. ch. shallow m-m 17.02 s § 10.25 s § p-p 22.30 s £ 10.00 s § rm-rp 1.00 ns § 11.08 s § rp-ri 23.06 s § 1.00 ns £ rm-ri 17.01 s £ 12.89 s £ lm-lp 14.25 s £ 18.9 s £ lp-li 30.6 s £ 1.00 ns = lm-li 18.9 s £ 21.25 s £ medium m-m 27.02 s £ 10.54 s £ p-p 22.8 s § 1.00 ns = rm-rp 36.9 s £ 14.52 s £ rp-ri 27.02 s § 23.69 s § rm-ri 28.03 s £ 17.89 s £ lm-lp 1.00 ns £ 12.35 s § lp-li 12.39 s § 14.87 s £ lm-li 1.00 ns = 23.22 s £ deep m-m 18.99 s £ 1.00 ns = p-p 18.02 s § 1.00 ns = rm-rp 17.89 s § 23.65 s £ rp-ri 23.65 s £ 12.47 s £ rm-ri 1.00 ns £ 18.98 s £ lm-lp 18.02 s § 25.32 s = lp-li 14.02 s § 18.70 s § lm-li 18.06 s § 17.23 s § palatal adaptation points t test fast & slow cycle (palatal adaptation) stone silicone t test sig. ch. t test sig. ch. shallow rv 1.00 ns £ 1.00 ns § rc 1.00 ns § 1.00 ns = m 1.00 ns £ 1.00 ns § lc 1.00 ns = 1.00 ns § lv 20.36 s £ 1.00 ns § medium rv 10.36 s £ 1.00 ns § rc 1.00 ns = 1.00 ns § m 18.69 s § 1.00 ns § lc 30.33 s § 1.00 ns § lv 17.02 s £ 1.00 ns § deep rv 17.66 s £ 20.36 s £ rc 12.30 s £ 1.00 ns = m 15.03 s £ 1.00 ns = lc 30.06 s £ 1.00 ns § lv 12.47 s £ 1.00 ns = palatal adaptation points t test stone & silicone (palatal adaptation) water bath fast cycle slow cycle ttest pvalue ch ttest pvalue ch ttest pvalue ch shallow rv 0 1.00 § 1.00 ns £ 1.00 ns § rc 0 1.00 § 1.00 ns § 1.00 ns = m 1.00 ns = 1.00 ns £ 1.00 ns § lc 0 1.00 = 1.00 ns £ 1.00 ns = lv 0 1.00 § 22.31 p<0.01 £ 1.00 ns § medium rv 0 1.00 § 23.04 p<0.01 § 1.00 ns § rc 0 1.00 § 25.05 p<0.01 § 1.00 ns § m 0 1.00 § 14.45 p<0.01 § 1.00 ns § lc 0 1.00 § 47.25 p<0.01 § 1.00 ns § lv 0 1.00 § 11.23 p<0.01 § 1.00 ns § deep rv 0 1.00 § 27.65 p<0.01 § 17.89 p<0.01 § rc 0 1.00 § 22.35 p<0.01 § 1.00 ns § m 1.00 ns = 1.00 ns = 10.25 p<0.01 § lc 0 1.00 § 18.97 p<0.01 § 1.00 ns § lv 0 1.00 § 1.00 ns § 1.00 ns § teeth movements points t test stone & silicone (teeth movement) water bath fast cycle slow cycle ttest pvalue ch ttest pvalue ch ttest pvalue ch shallow m-m 10.25 p<0.01 § 10.23 p<0.01 § 23.17 p<0.01 § p-p 10.36 p<0.01 § 15.58 p<0.01 § 15.97 p<0.01 § rm-rp 1.00 ns = 45.12 p<0.01 § 1.00 ns § rp-ri 23.65 p<0.01 £ 1.00 ns § 20.14 p<0.01 £ rm-ri 12.56 p<0.01 § 28.97 p<0.01 £ 17.87 p<0.01 £ lm-lp 14.25 p<0.01 § 17.98 p<0.01 £ 1.00 ns = lp-li 18.98 p<0.01 £ 1.00 ns = 23.54 p<0.01 § lm-li 24.28 p<0.01 § 23.35 p<0.01 § 19.24 p<0.01 § medium m-m 1.00 ns § 1.00 ns = 22.18 p<0.01 £ p-p 1.00 ns = 20.13 p<0.01 § 1.00 ns = rm-rp 26.25 p<0.01 § 15.64 p<0.01 £ 18.47 p<0.01 £ rp-ri 24.29 p<0.01 £ 41.21 p<0.01 § 20.25 p<0.01 § rm-ri 19.30 p<0.01 § 23.25 p<0.01 § 1.00 ns = lm-lp 26.25 p<0.01 £ 20.14 p<0.01 £ 1.00 ns § lp-li 24.29 p<0.01 § 11.54 p<0.01 § 28.45 p<0.01 £ lm-li 19.30 p<0.01 § 18.97 p<0.01 § 23.45 p<0.01 £ deep m-m 1.00 ns § 17.89 p<0.01 £ 10.15 p<0.01 § p-p 77.23 p<0.01 § 23.24 p<0.01 § 10.24 p<0.01 § rm-rp 1.00 ns = 18.97 p<0.01 § 11.12 p<0.01 £ rp-ri 1.00 ns § 23.14 p<0.01 § 11.36 p<0.01 £ rm-ri 26.25 p<0.01 £ 1.00 ns § 14.15 p<0.01 £ lm-lp 24.29 p<0.01 § 25.64 p<0.01 § 17.21 p<0.01 § lp-li 19.30 p<0.01 £ 1.00 ns = 1.00 ns = lm-li 26.25 p<0.01 § 10.25 p<0.01 § 19.32 p<0.01 § table 6: t-test between stone and silicone investment for curing methods and palatal depths in both teeth movements and palatal adaptation. j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 9 discussion the dimensional accuracy of the cured denture base is directly influenced by the topographic structures of the edentulous ridge, which may lead to disturbances in the planned teeth position or even losing the intimate adaptation of the base to the underlying tissues rendering the denture functionally useless. (21) for teeth movements it expected to occur toward the largest bulk of resin mass, compared with the resin in the palate, so more dimensional changes always occur in the center of the area of higher thickness and this explain the teeth movements in that directions. (5) for palatal adaptation: dimensional changes tend to pull the flanges toward each other leading to tensile stress on the molar teeth that will contact the mold and distortion. these forces were divided into vertical and transverse one, which is high in relation to the small surface area of deep palate and will pull the resin mass toward the center of the palate leading to high volume of the mass in that area and increase the thickness and so the amount of the gap space will be more in the deep palate than the medium and shallow one. (22) curing methods: during water bath curing, the resin base is not homogeneously cured due to variations in flasks proximity from the curing source. so the curing is not evenly completed and the dimensional inaccuracies increased. (23) also, when acrylic were cured by water bath; first at 74°c and 90 minutes, the temperature were less than glass transition temperature of acrylic resin, so, after it was left to cool at room temperature, internal stresses will be created. (24,25) then, when curing were finished, at 100°c and 30 minutes, the internal stresses will be released.(26) which will be more exaggerated after flask opening.(27) the autoclave curing resulted in better stability when compared with water bath due to that autoclave provide even heat spreading and more cross linking between the polymer chains with better opportunity for complete polymerization. (28) on the other hand, the excess temperature occupied by pressure exerted with autoclave leads to faster rate of polymerization. so no residual monomer will resulted, with less chance of dimensional inaccuracies. (29) autoclave curing time influenced dimensional stability. slow curing leads to increase in the dimensional accuracies. the reason for that is: resin curing leads to heat generation which will be further increased by curing machine heat, so there will be complete polymerization of the resin mass exhausting the residual monomer. (28,29) and when the time of curing increased, the resin approach the solidification temperature; glass transition temperature (tg), resulting in less dimensional changes at the time of flask opening. (25) investment materials the stone is difficult investment during deflasking, in addition to high stress during curing leads to strain due to stress release. also, curing in water bath leads to water sorption of stone and volumetric expansion combined with setting one. while, the coefficient of thermal expansion for stone is less than that of acrylic resin, so space will be formed below the base. (30) on the other hand, the acceptable tear strength of silicone during deflasking, made it better and simpler investing medium to deal with, so sharp knife will be sufficient during denture retrieving without the need for excessive force. (31) references 1. sykora o, sutow ej. comparison of the dimensional stability of two waxes and two acrylic resin processing technique in the production of complete dentures. j oral rehab 1990; 17: 219-227. 2. consani rl, domitti ss, consani s. effect of new tension, used in acrylic resin flasking on dimensional stability of denture bases. j prosthet dent 2002; 88: 2859. 3. negreiros wa, consani rl, mesquita mf, sinhoreti ma, faria ir. effect of flask closure method and postpressing time on the displacement of maxillary denture teeth. open dent j 2009; 21-25. 4. glazier s, firtell d, haiman l. posterior palatal seal distorsion related to height of the maxillary ridge. j prosthet dent 1980; 43(5):508-10 5. farah nabeel mt. the effect of flasking tension system on the adaptation of acrylic resin denture base in different palatal models and base thicknesses. a master thesis, college of dentistry, university of baghdad, 2007. 6. peroz i, manke p, zimermann e. polymerization shrinking of prosthetic plastic materials in a variety of manufacturing processes. in german zwr 1990; 99: 292-6. 7. hedge v, patil n. comparative evaluation of the effect of palatal vault configuration on dimensional changes in complete denture during processing as well as after water immersion. indian j dent res 2004; 15:62-5. 8. boscato n, consani r, consani s, cury aa. effect of investment material and water immersion time on tooth movement in complete denture. eur j prostho rest adanet 2005; 13:164-9. 9. baydas s, bayindir f, akyil ms. effect of processing variables (different compression packing processes and investment materials types) and time on the dimensional accuracy of polymethyl methacylate denture bases. dent mater j 2003; 22:206-13. 10. al-fahdawi ih. the effect of the poly vinyl pyrrolidone (pvp) addition on some properties of heatcured acrylic j bagh college dentistry vol. 28(1), march 2016 teeth displacement and restorative dentistry 10 resin denture base material. phd thesis, college of dentistry, university of baghdad, 2009. 11. judelson hs. operation of the autoclaves. an excellent overview of autoclave. operation posted by dr. howard judelson at university of california at riverside, 2004. 12. dalkiz m1, arslan d, tuncdemir ar, bilgin ms, aykul h. effect of different palatal vault shapes on the dimensional stability of glass fiber-reinforced heatpolymerized acrylic resin denture base material. eur j dent 2012; 6(1):70-8. 13. abd sa. tooth movement in maxillary complete dentures fabricated with fluid resin polymer using different investment materials. m.sc. thesis, college of dentistry, university of baghdad, 2009 14. shinsuke s, toshya i, taizo h, arfzan r. a comparison of three dimensional changes in maxillary complete denture between conventional heat polymerizing and microwave polymerizing technique. dent j (maj.ked.gigi) 2007; 40(1): 6-10. 15. rafael lx, marcelo fm, mario ac, simonides c. influence of the deflasking delay time on the displacements of maxillary denture teeth. j appl oral sci 2003; 11(4): 332-6. (ivls) 16. shibayama r, gennari fh. mazaro jv. vedovato e. assuncao wg: effect of flasking and polymerization techniques on tooth movements in complete denture processing. j prosthodont 2009; 18: 259-64. 17. sykora o, sutow ej. posterior palatal seal adaptation: influence of processing technique, palate shape and immersion. j oral rehabil 1993; 20:19-31. 18. arbaz s. a comparative study of two different investment mediums on the movements of artificial teeth during the fabrication of complete dentures: an in vitro study. int j prosthet restor dent 2011;1(3):141-6. 19. salwan sa, widad aha. the effect of autoclave processing of heat cured denture base material. j bagh college dentistry 2012; 24(3):13-17. 20. sabrina p, joao naf, paulo hds, francisco dam. effect of microwave treatments on dimensional accuracy of maxillary acrylic resin denture base. braz dent j 2005; 16(2): 1-6. 21. ono t, kita s, nokubi t. dimensional accuracy of acrylic resin maxillary denture base polymerized by a new injection pressing method. dent mater j 2004; 23 (3): 348-52. 22. wolfaardt j, cleaton-jones p, fatti p. the influence of processing variables on dimensional changes of heatcured poly (methyl methacrylate). j prosthet dent 1986; 55: 518 23. yeung kc, chow tw, clark rk. temperature and dimensional changes in two stages processing technique for complete dentures. j dent 1995; 23: 254-53. 24. pow eh, chow tw, clark rt. linear dimensional change of heat cured acrylic resin complete dentures after reline and rebase. j prosthet dent 1998; 80: 23845. 25. caycik s, jagger rg. effect of cross-linking chain length on glass transition of a dough-molded pmma. dent mater 1992; 8(3):153-7 26. wong dm, cheng ly, chow tw, clark k. effect of processing method on the dimensional accuracy and water sorption of acrylic resin dentures. j prosthet dent 1999; 81: 300-4. 27. al-khafaji am. the effect of four different cooling procedures on the dimensional stability of microwave activated acrylic resin at different time intervals. j bagh college dentistry 2011; 23(2). 28. sidhaye a.b. polymerization shrinkage of heat cured acrylic resins processed under steam pressure. indian dent assoc 1981; 53: 49-51. 29. miettinen vm. vallittu pk. release of residual methyl methacrylate into water from glass fiber pmma composite used in denture. biomaterial 1997; 18:181-5. 30. shadi elb, klaus l, abdul-aziz s, sandra fl, matthias k. linear and volumetric dimensional changes of injection molded pmma denture base resins. dent mat 2013; 29:1091-7. 31. mainieri et, boone me, potter rh.tooth movement and dimensional change of denture base materials using two investment methods. j prosthet dent 1980; 44(4): 368-73. j bagh college dentistry vol. 31(4), december 2019 angiopoietin-2 19 angiopoietin-2 immunohistochemical expression in oral squamous cell carcinoma intisar abdel-jabbar al-sarraf, b.d.s.(1) ban f. al-drobie b.d.s., m.sc., ph.d. (2) abstract background: there are various secreted proteins affecting the prognosis of oral squamous cell carcinoma (oscc) and one of them is angiopoietin-2(ang-2) which is thought to have an essential role in the development and progression of the tumor. aim of the study: this study was conducted to determine the expression of (ang-2) in (oscc) to assess its correlations with clinicopathological parameters of the tumor. material and methods: 36 formalinfixed, paraffinembedded tissue blocks histologically diagnosed as oscc were examined for ang-2 immunohistochemical expression semi quantitively. results: the expression of ang-2 was significantly associated with histopathological grade (p value=0.023), while there is no significant association with the clinical parameters analyzed in oscc patients. conclusion: a significant association between ang-2 expression and histopathological grade of oscc may predict its biological behavior. key words: oscc, angiogenesis, ang-2. (received: 15/1/2018; accepted: 19/2/2018) introduction oral squamous cell carcinoma (oscc): is a malignant epithelial tumor of oral cavity that derived from the lining stratified squamous epithelium(1). both genetic and environmental factors in addition to the viral infections are incorporated in the pathogenesis of oscc(2) an important number of patients developed oscc at early stages, and with small sized tumor, they may develop poor prognosis ,so the level of histopathological differentiation can predict the biological specific and aggressive clinical behavior of the tumor.(3;4) so when the tumor histopathologically appeared mature and look like the epithelial tissue which is originated from (quite resemblance to squamous cells, keratin pearls, less cells or nuclear pleomorphism) tend to grow slowly and not metastasized unless in latent stage which is called well differentiated, low grade, or grade ι oscc(5) in contrast, a tumor with marked pleomorphism and little or no keratin production may be so immature so it becomes difficult to identify the tissue of origin. graded as ιιι and called poorly differentiated or high grade oscc. the tumor appeared in between, graded ιι or so called moderately differentiated (6) 1. master’s student, department of oral diagnosis, college of dentistry, university of baghdad. 2. assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. angiopoietin-2 (ang-2), a member of the angiopoietin family proteins functioned as ligands for the endothelial-specific tyrosine kinase receptor "tie2" (7).in neoplasms of different histological origin (e.g., gastric, colon, prostate, breast, and brain carcinomas),the expression of ang-2 is elevated and linked with poor prognosis(8). studies showed that ang-2 may overexpressed in oscc and it always associated with aggressive tumor behavior and poor prognosis (9,7) the aim of present study is to evaluate the expression of ang-2 in number of patients diagnosed as oscc and its association with clinicopathological parameter of the disease. material and method tissue sample thirty six retrospective formalinfixed, paraffinembedded tissue blocks diagnosed histopathologically as oscc were enrolled in this study. the blocks were obtained from the archives of the oral maxillofacial pathology department / dentistry collage of baghdad university. demographic and clinical data : patients name, age, gender, clinical presentation, , and tumor site were obtained from the archive. normal placental tissue of human for ang-2 antibody immunohistochemical detection obtained from al-shaheed ghazi hospital, teaching laboratory department/ baghdad medical city j bagh college dentistry vol. 31(4), december 2019 angiopoietin-2 20 figure 1: immunohistochemical expression ofang-2 in normal human placental tissues(x100). conventional immunohistochemistry (ihc). after deparaffinization and rehydration were done to the prepared histological sections, blocking of endogenous peroxidase was performed by incubation them with 3 % hydrogen peroxide for 10 min. then blocking for nonspecific antibodies binding by incubation them for 1 hour with normal goat serum. sections were then incubated with primary antibody, an anti ang-2 monoclonal antibody (1/100) dilution; (abcam company [mm0020-1f29] ab56301) overnight at 4o c. then washed with phosphate-buffered saline (pbs, ph = 7.0). by using the detection kit, the slides were incubated with secondary antibody (rabbit anti mouse antibody unconjugated then gout anti –rabbit hrp conjugated) 10min for each followed by incubation with 3,-3,diaminobenzidine chromogen (dab)for 1min at 37oc. all sections then stained with haematoxylin as a counter stain, dehydrated through graded alcohols, and at last, mounted. for each ihc run a positive control tissue sample (normal placenta) and a negative control sample (consisted of sample in which the primary antibody were replaced by pbs) was included. immunohistochemical evaluation of ang-2 antibody: to assess the immunohistochemical expression of ang-2, two pathologist who blinded to the any information presented in the case sheets of the patients two pathologists, who were blinded to the patients’ information. immuno-re activity of ang2 was primarily detected in the cytoplasm of tumor cells. the expression was performed using a semi quantitative staining intensity score: no staining was scored as 0, faint staining as 1, moderate as 2, and high intensity staining as 3.(10) statistical analysis categorical variables were represented by number(n) and percentage (%) and the different percentages were tested using chi-square test(𝑥2). statistical significance was considered whenever the p value was less than 0.05. result this study included thirty six of histopathologically confirmed oscc cases, males were 20 (55.6%) while female were 16 (44.4%). patients age ranged between 22-83 years, and the mean age was 52.4 years. the most predominant age group was (70-79) years which account 10 cases (27.78%). clinically the study sample was presented most predominantly as an ulcer (21 cases of 58.33%), while mass compromised 15 cases(41.67%). the most predominant affected site with tumor was tongue of 17 cases (47%) followed by floor of mouth account 7 cases (19%). most predominant histopathological grade was moderately differentiated as 14 cases (38.89%), followed by well differentiated as 13 cases (36.11%), lasted with poorly differentiated 9 cases (25%). table (1) showed the association between gender and site, the association was found to be statistically non-significance (p value>0.05). table1: distribution of study sample according to site and gender. site gender male female total n % n % n % tongue 9 45.00 8 50.00 17 47.22 floor of the mouth 2 10.00 5 31.25 7 19.44 buccal mucosa 2 10.00 2 12.50 4 11.11 mandible 3 15.00 0 .00 3 8.33 soft palate 2 10.00 0 .00 2 5.56 hard palate 1 5.00 1 6.25 2 5.56 alveolar ridge 1 5.00 0 .00 1 2.78 total 20 100.00 16 100.00 36 100.00 χ2= 6.986 d f=6 p= 0.322 table (2) showed that moderately differentiated oscc was the most predominant histopathological grade account 14 cases. j bagh college dentistry vol. 31(4), december 2019 angiopoietin-2 21 table 2: the distribution of study sample according to the histopathological grade of the tumor. grade n % well differentiated 13 36.11 moderate differentiated 14 38.89 poor differentiated 9 25.00 total 36 100.00 table (3) showed the distribution of study sample according to ang-2. half of cases with moderate staining, those with faint and strong staining represented (8,9 cases respectively), and one case only with no staining. table 3: sis of ang-2 antibody immunohistochemical expression in the study sample % n score sis (ang-2) 2.78 1 0 22.22 8 1 50 18 2 25 9 3 100 36 total ang-2: angiopoietin-2, sis: staining intensity score. 0: no staining.1: faint staining.2: moderate staining. 3: strong staining. table(4,5, 6, 7) the association between ang-2 expression with (age group, gender, clinical presentation, sites) were found to be statistically non significance (p value>0.05). table 4: association between ang-2 expression and age group in the study sample age groups ang-2 no staining faint moderate strong total n % n % n % n % n % <0r=39 0 .0 1 12.5 6 33.3 0 .00 7 19.4 40-49 0 .0 1 12.5 3 16.7 1 11.12 5 13.9 50-59 1 100 2 25. 0 .00 2 22.22 5 13.9 60-69 0 .0 2 25. 4 22.2 3 33.33 9 25.0 >0r=70 0 .0 2 25. 5 27.8 3 33.33 10 27.8 total 1 100 8 100 18 100 9 100 36 100 𝑥2=14.184 d f =12 p=0.289 table 5: association between ang-2 expression and gender of the study group gender ang-2 no staining faint moderate strong total n % n % n % n % n % male 1 100. 5 62.5 11 61.11 3 33.33 20 55.56 female 0 .00 3 37.5 7 38.89 6 66.67 16 44.44 total 1 100. 8 100. 18 100. 9 100. 36 100. 𝑥2= 2.981 df-3 p=0.395 table 6: the association between ang-2 expression and clinical presentation of oscc. clinical presentation ang-2 no staining faint moderate strong total n % n % n % n % n % ulcer 1 100. 6 75. 8 44.4 6 66.7 21 58.3 mass 0 .00 2 25. 10 55.6 3 33.3 15 41.7 total 1 100. 8 100. 18 100. 9 100. 36 100. 𝑥2 =3.314 d f=3 p=0.346 table 7: association of ang-2 expression and site of distribution of study sample. site ang-2 no staining faint moderat e strong total n % n % n % n % n % tongue 0 .00 5 62.5 8 44.4 4 44.5 17 47.2 floor of mouth 0 .00 0 .00 6 33.2 1 11.1 7 19.4 buccal mucosa 1 100 0 .00 1 5.6 2 22.2 4 11.1 mandible 0 .00 2 25. 0 .00 1 11.1 3 8.3 soft palate 0 .00 1 12.5 1 5.6 0 .00 2 5.6 hard palate 0 .00 0 .00 1 5.6 1 11.1 2 5.6 alveolar ridge 0 .00 0 .00 1 5.6 0 .00 1 2.8 total 1 100 8 100 18 100 9 100. 36 100 𝑥2=21.852 d f=18 p=0.239 table (8) showed the association between ang-2 expression and histopathological grade of oscc of the study sample, the association was found to be statistically significant(p value=0.023). j bagh college dentistry vol. 31(4), december 2019 angiopoietin-2 22 table 8: the association between ang-2 expression and the grade of the study sample. x2=14.674 d f=6 p=0.023* 𝑥2= ang-2: angiopoietin-2. w.d: well differentiated. m.d: moderately differentiated. p.d: poorly differentiated. *: p value<0.05. figure 1: no staining (score0 in sis ) of ang-2 expression of the studied samples. (x100). figure 2: faint staining (score1 in sis) of ang-2 expression in the studied samples (x100). figure3: moderate staining (score2 at sis) of ang-2 expression in studied samples (x100). figure4: strong staining(score3 in sis) of ang-2 expression of the studied samples (x100). discussion there are numerous molecules overexpressed in oscc, associated with aggressive behavior of the tumor and may affect its prognosis. according to the current study; ang-2 was expressed in 75% of the cases (ranged between moderately stained as 50%, to strong stained as 25% of the cases). although the association between the ang-2 expression and clinicopathological parameters of the studied tumor was found to be statically non significance( p value>0.05). there was significance association between ang2 expression and the histological grade of the tumor (p value=0.023) which agreed with previous studies (11,7) but disagreed with ( 9,12,13) while tumor progressed, there is a great need for oxygen and the microenvironment suffered from hypoxic condition that, s stimulate ecs, tumors, cells to secret different cytokines which enhanced angiogenesis, and one of them is ang-2(14,15) overexpression of ang-2 could lead to decrease cell apoptosis so promotes tumorgenesis, on the other hand, ang-2 thought to have an essential role in the angiogenesis process by enhanced epithelial-mesenchymal transition "(16, 17, 18) grade ang-2 no stain faint moderate strong total n % n % n % n % n % w.d 0 .00 7 87.5 4 22.2 2 22.2 13 36.1 m.d 0 .00 1 12.5 9 50. 4 44.4 14 38.9 p.d 1 100 0 .00 5 27.8 3 33.3 9 25. total 1 100 8 100. 18 100. 9 100. 36 100. j bagh college dentistry vol. 31(4), december 2019 angiopoietin-2 23 previous studies showed that ang-2 induces transformation of noncancerous liver to hepatocellular carcinoma (19). in addition, that ang-2 mostly associated with disease progression, metastasis, and poor prognosis(20,8) recent studies on ang-2-vegf-a crossmab showed the efficient and less harm effects on animals proposed that it characterized a new and active therapeutic chance for patients with malignancy with the probability to replace bevacizumab as a conclusion ang-2 was overexpressed in oscc and significantly associated with histopathological grade of the tumor. references 1. . rivera c and venegas b. histological and molecular aspects of oral squamous cell carcinoma (review). oncol lett. 2014; 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2 (3): 213–219. 15. thomas m, kienast y, scheuer w, ba¨hner m, kaluza k, et al. a novel angiopoietin-2 selective fully human antibody with potent anti-tumoral and antiangiogenic efficacy and superior side effect profile compared to pan-angiopoietin-1/-2 inhibitors. plos one 2013; 8(2): e54923. 16. tse v, xu l, yung yc, santarelli jg, juan d, fabel k, silverberg g, harsh g: the temporal-spatial expression of vegf, angiopoietin-1 and 2, and tie-2 during tumor angiogenesis and their functional correlation with tumor neovascular architecture. neurol res. 2003, 25: 729-738. 17. fagiani e, christofori g.cancer lett. 2013 jan 1; 328(1):18-26. 18. li c, li q, cai y, he y, lan x et al overexpression of ang2 promotes the formation of oscc. cancer gene therapy .2016; 23(9), 295–302. 19. zhang z-l, liu z-s, sun q. expression of angiopoietins, tie2 and vascular endothelial growth factor in angiogenesis and progression of hepatocellular carcinoma. world journal of gastroenterology : wjg. 2006;12(26):4241-4245 20. ochiumi t, tanaka s, oka s, hiyama t, ito m, kitadai y, et al. clinical significance of angiopoietin-2 expression at the deepest invasive tumor site of advanced colorectal carcinoma. int j oncol. 2004; 24: 539–47. 21. kienast y, klein c, scheuer w, raemsch r, lorenzon e . ang-2-vegf-a crossmab, a novel bi specific human igg1 antibody blocking vegf-a and ang-2 functions simultaneously, mediates potent antitumor, antiangiogenic, and anti metastatic efficacy clin cancer res.2013; 19(24):6730-40. . https://www.ncbi.nlm.nih.gov/pubmed/24959211 https://www.ncbi.nlm.nih.gov/pubmed/?term=brandwein-gensler%20m%5bauthor%5d&cauthor=true&cauthor_uid=15644773 https://www.ncbi.nlm.nih.gov/pubmed/?term=teixeira%20ms%5bauthor%5d&cauthor=true&cauthor_uid=15644773 https://www.ncbi.nlm.nih.gov/pubmed/?term=lewis%20cm%5bauthor%5d&cauthor=true&cauthor_uid=15644773 https://www.ncbi.nlm.nih.gov/pubmed/?term=lee%20b%5bauthor%5d&cauthor=true&cauthor_uid=15644773 https://www.ncbi.nlm.nih.gov/pubmed/?term=lee%20b%5bauthor%5d&cauthor=true&cauthor_uid=15644773 https://www.ncbi.nlm.nih.gov/pubmed/15644773 j bagh college dentistry vol. 31(4), december 2019 angiopoietin-2 24 الخالصة و تقىىم عالقته بالنواحى السرىرىة والمرضية لسرطان الفم الحرشفى angiopoietin-2الظهور الكىمىائى النسىجى المناعى لمعلم ويعتقد angiopoietin-2(ang-2)الخلفىة:هناك الكثىر من البرويىنات التي تفرز والتي لها تاثيرفي توقع نتائج مرض سرطان الفم الحرشفي واحد هؤالء هو المعلم ان له دور اساسي في نشوء وتفاقم هزا النوع من السرطان. في سرطان الفم الحرشفي وتقييم ارتباطه بالنواحي السريرية والمرضية والتمايز ang-2اهداف الدراسة: ان هذه الدراسة تشير الى تحديد الظهور المناعي لمعلم النسيجي لهدا النوع من الورم. الدراسة ست وثالثون عينة مسترجعة استخرجت من المقاطع النسيجية المطمورة بشمع البرافين ثم اجريت عليها الفحوصات النسيجية الطرق و االدوات:تضمنت وقرات النتائج باستخدام طريقة حساب شدة التصبيغ شبه الكمية. ang-2 والمناعية النسيجية الكيميائية لمعلم ( (p value=0.023وارتباطه مع الدرجة النسيجية المرضية والعالقة ذو داللة معنوية ang-2يالنتائج: بينت النتائج ظهور المعلم المناع معنوية مع النواحي السريرية والمرضية لسرطان الفم الحرشفي. كما اوضحت هذه الدراسة عدم وجود داللة في تقييم السلوك البيولوجي وتخميين نتائج المرض. ا يشير الهميتهوهذ ang-2االستنتاجات: كشفت هده الدراسة مستويات مرتفعة من التعبير المناعي لمعلم j bagh college dentistry vol. 31(4), december 2019 the effects of 59 the effects of nano alumina on mechanical properties of room temperature vulcanized maxillofacial silicone (pilot study) ahmed aj. abdulkareem, b.d.s. (1) thekra i. hamad, b.d.s, m.sc. ph.d (2) abstract background: facial disfigurement can be the result of a congenital anomaly, trauma or tumor surgery, in many cases the prosthetic rehabilitation is indicated. maxillofacial prosthetic materials should have desirable and ideal physical, aesthetic, and biological properties and those properties should be kept for long period of time in order to reach patient acceptance. silicone elastomer are the most commonly used material for facial restoration because of its favorable properties mechanically and physically as the biocompatibility and good elasticity. aim of this study: this study aimed to evaluate the effect of addition of aluminum oxide (al2o3) nano fillers in different concentrations on tear strength and hardness of vst 50f room temperature vulcanized maxillofacial silicone. methods: the nano al2o3 was added in a concentrations of 0.5, 1, 1.5 and 2 by weight to the vst 50f rtv maxillofacial silicone, the samples were tested for tear strength (iso 34 -1) and shore a hardness (iso 7619), the ftir was used to analyze the interaction of the nano al2o3 with the silicone. the data were analyzed using descriptive and inferential statistics. one-way anova test was used to test the changing significance. results: there was no interaction between the nano-al2o3 and the silicone in the ftir. the results showed highly significant increase in tear strength and shore a hardness for the 1 and 1.5 concentration groups when compared to control group. conclusion: the reinforcement of vst 50f maxillofacial silicone with 1 and 1.5 concentrations of nano al2o3 improved some of the mechanical properties of the room temperature vulcanized silicone. keywords: rtv maxillofacial silicone, nano al2o3, tear strength, shore a hardness. (received: 29/7/2019; accepted: 1/9/2019) introduction the first part of the body that will contact the world is the face, the accepted appearance of the face is now became mandatory to be accepted in a job, appear in magazine or television and in marriage looking. surgical reconstruction of the facial defects may not be possible owing to size or location of the defect, the patient's medical condition or personal desires may also preclude reconstructive surgery. in such cases, prosthetic rehabilitation is indicated (1). some nano fillers are added to the matrix of maxillofacial silicone to improve its properties, as in the addition of titanium silicate which resulted in improvement of the mechanical properties of the rtv maxillofacial silicone (2). the aluminum oxide (al2o3) as a nano-fillers characterized by its fair chemical inertness, its strength and stiffness among other ceramic oxides and by a preferable dielectric properties and refractoriness (3). 1. m.sc. student (prosthodontics department, college of dentistry/ university of baghdad, iraq) 2. prof. (prosthodontics department, college of dentistry/ university of baghdad, iraq) corresponding author: dr. ahmed abdul jaleel e-mail: sl.sl91@yahoo.com the aim of this study was to evaluate the effect of addition of different concentrations (0.5,1%, 1.5% and 2) by weight of al2o3 nano-fillers on tear strength and shore a hardness of vst 50f rtv maxillofacial silicone. materials and methods the materials used in this study listed in (table 1). table 1: the study materials two main groups were prepared, one for the tear strength test and the other for the hardness test, in each one of them a 25 samples were fabricated, each main group subdivided into five subgroups which are the control group 0(without nano addition), 0.5, 1, 1.5 and material manufacturer patch number vst 50f rtv maxillofacial silicone elastomer factor ii inc., usa b 1019181lb aluminum oxide nano fillers 99.5 purity, 4060 nm. us research nanomaterials inc., usa 134428-1 mailto:sl.sl91@yahoo.com j bagh college dentistry vol. 31(4), december 2019 the effects of 60 2 by weight nano al2o3 addition groups, each of them had 5 samples. plastic molds were fabricated using cnc machine, each mold consists of base, frame and cover parts in the same dimensions. the maxillofacial silicone type used in this study was the vst 50f room temperature vulcanized one which is a two parts silicone, the mixing ratio of the base to the catalyst was 10:1 according to the manufacturer instructions, the mixing of the control group began with the addition of the base to the electronic balance container then the catalyst was added and started mixing by the vacuum mixer with a speed of 360 rpm and a vacuum was of (-10 bar), for the reinforced groups the nano powder was added to the electronic balance container followed by addition of the base then starting mixing without vacuum for 3 minutes followed by mixing with a vacuum for 7 minutes followed by catalyst addition and mixing with vacuum for the remaining 5 minutes (4). the silicone became ready to be poured in the molds of tear strength test and hardness test, followed by tighten the cover with the remaining molds parts by the g-clamps. after 24 hours of complete vulcanization of the rtv silicone the mechanical properties were tested. the tear strength calculated using the following formula according to the astm d624 (2012) (5): 𝑻𝒆𝒂𝒓 𝒔𝒕𝒓𝒆𝒏𝒈𝒕𝒉 = 𝐅 (𝐌𝐚𝐱𝐢𝐦𝐮𝐦 𝐟𝐨𝐫𝐜𝐞 𝐚𝐭 𝐛𝐫𝐞𝐚𝐤𝐚𝐠𝐞(𝐊𝐍)) 𝑫 (𝒕𝒉𝒊𝒄𝒌𝒏𝒆𝒔𝒔 𝒐𝒇 𝒕𝒉𝒆 𝒔𝒂𝒎𝒑𝒍𝒆(𝒎)) a samples with flat ends and a right angle at the middle. while the hardness test was done by a digital shore a hardness durometer device according to astm d2240-05 (6), a samples with a length of 25 mm and a width of 25 mm and a thickness of 6 mm were fabricated. results the statistical results of tear strength test showed a highly significant increase in 1 and 1.5 groups by doing the one way anova test and found that the p values  0.05. the results of shore a hardness tests showed an increasing in all reinforcement groups except in 0.5 group when compared to the 0 group by doing the one way anova test and found that the p value  0.05 (table 2 and 3). table 2: statistical test of tear strength (n/mm) table 3: statistical test of the shore a hardness (iu) there was no any interaction between the al2o3 nano fillers and the vst 50f maxillofacial silicone in the ftir analysis (figures 12). groups minim um maxi mum mea n ±sd f p valu e 0% al2o3 25.5 25.7 25.6 0.22 116 .63 .001 0.5% al2o3 25 25.2 25.1 0.31 1% al2o3 26 26.6 26.2 0.26 1.5% al2o3 27.9 28.4 28.2 0.22 2% al2o3 26.4 26.8 26.6 0.14 groups minim um maxi mum mea n ±sd f p value 0% al2o3 27.3 27.9 27.4 0.4 50 0.7 0.000 0.5% al2o3 26.5 26.9 26.7 0.23 1% al2o3 27.5 27.7 27.6 0.3 1.5% al2o3 28 28.5 28.3 0.3 2% al2o3 34.5 34.9 34.6 0.3 j bagh college dentistry vol. 31(4), december 2019 the effects of 61 figure 1: the ftir of the vst 50f maxillofacial silicone before addition of al2o3 nano fillers figure 2: the ftir of the vst 50f maxillofacial silicone after addition of al2o3 nano fillers discussion many previous studies results showed that the addition of fillers in a nano scale improved the mechanical properties of the maxillofacial silicone, so the aluminum oxide nano fillers were chosen to be added because it had many preferable properties when compared to other nano filler types (3). the results showed an increase in tear strength after reinforcement except for the 0.5 and 2 reinforcement groups, that may be due to the ability of the nanoparticles to be trapped within the silicone matrix and in some polymer chains and then a 3d mesh formation would result in a physical interaction which my lead to increase the density of the silicone and the resistance to tear(7). for the decrease in tear strength in the 0.5 this may be due to the very small amounts of fillers which act as impurities that would affect the polymerization process of the silicone without formation a 3d mesh (8), while for the decrease in tear strength in the 2 group this may be caused by beginning of fillers to agglomerate in the silicone matrix with the increasing in concentration of added fillers which may results in restriction of flow and movement of the polymer matrix when the stretching forces increased (9) shore a hardness also increased for the reinforced samples which may be due to the filler adherence to each other when increasing the filler concentrations made it fill the inter-aggregate areas within the silicone matrix so it will resist the indentation loads (10). for the reduction in the 0.5 group may be due to the small amounts of the nano fillers added which would be as an impurities and interact with the polymerization process of the silicone (8). conclusions the reinforcement of vst 50f rtv maxillofacial silicone with 1 and 1.5 nano al2o3 improved some of the mechanical properties of silicone with the best improvement occur after 1 and 1.5 nano al2o3 reinforcement. references 1. maller, u. s., karthik, k. & maller, s. v. (2010). ''maxillofacial prosthetic materials—past and present trends''. jiads, 1(2), 25-30. 2. alsmael, m. a., & ali, m. m. m. (2018). ''the effect of nano titanium silicate addition on some properties of maxillofacial silicone material''. journal of research in medical and dental science, 6(5), 127-132. 3. saritha mk, shadakshari s, nandeeshwar db, tewary s. an in vitro study to investigate the flexural strength of conventional heat polymerised denture base resin with addition of different percentage of aluminium oxide powder. asian j med clin sci. 2012;1(2):80-5. 4. tukmachi m, moudhaffer m. effect of nano silicon dioxide addition on some properties of heat vulcanized maxillofacial silicone elastomer. jpbs. 2017;12(3-4):37-43. 5. astm d624-00, (2012). "standard test method for tear strength of conventional vulcanized rubber and thermoplastic elastomers". astm international, west conshohocken, pa, usa. 6. astm d2240-05, (2010). " standard test method for rubber property-durometer hardness". astm international, west conshohocken, pa, usa. 7. harper ca. handbook of plastics, elastomers, and composites. new york: mcgraw-hill; 2002 jun. 8. guiotti, a.m., goiato, m.c., dos santos, d.m., vechiato-filho, a.j., cunha, b.g., paulini, m.b., j bagh college dentistry vol. 31(4), december 2019 the effects of 62 moreno, a., de almeida, m.t.g., 2015. "comparison of conventional and plant-extract disinfectant solutions on the hardness and color stability of a maxillofacial elastomer after artificial aging". j prosthet dent. 9. zayed, s. m., alshimy, a. m. & fahmy, a. e. (2014). ''effect of surface treated silicon dioxide nanoparticles on some mechanical properties of maxillofacial silicone elastomer''. int j biomater, 2014, 750398-750405. 10. alsmael ma, ali mm. the effect of nano titanium silicate addition on some properties of maxillofacial silicone material. journal of research in medical and dental science. 2018 jan 1;6(5):127-32. :الخالصة ، توجد عدة مواد لعمل تعويضات الوجه والفكين يجب ان تكون مصنوعة من مواد ذات خصائص متوافقة مع الجلد واالنسجة الرخوة حول الجزء المفقودمقدمة: استعماال في وقتنا الحالي هي مادة السيليكون المطاط الخاص ولكن وجد ان خصائص مادة السيليكون الخام غير كافيه الستعماله في تعويضات الوجه ولكن اكثرها .لفيزيائيةلميكانيكية واتعويضات الوجه لذلك ركزة كثير من البحوث في اآلونة األخيرة على اضافه حبيبات االكاسيد النانوية الى السيليكون بهدف تحسين خصائصه ا الغرض من هذا البحث هو دراسة تأثيرات إضافة حبيبات اكاسيد األلمنيوم النانوية على بعض الخصائص الميكانيكية لسيليكون تعويضات الوجه اهداف البحث: (. 2, 1.5, 1 ,0.5والفكين.تم إضافة اكاسيد االلمنيوم النانوية بتراكيز مختلفه ) ، قوة التمزقلفحص تم تحضير مجموعتين رئيسيتين من العينات المجموعة األولىونسبها و السيليكون المادة طخل طريقة في المصنّع تعليمات تم اتباعطريقة العمل: .السيليكون مع لحبيبات اكاسيد االلمنيوم النانوية الكيميائي االرتباط لتقييم ftir فحص وتم إجراء والمجموعه الثانيه لفحص الصالبة كما من الحبيبات 1,5و 1لمجموعتي التركيزين المضافين والصالبة وكانت اعلى النتائج هي زيادة عالية احصائيا بقوة التمزق االختباراتأظهرت نتائج النتائج: النانوية مقارنة بالمجموعات األخرى والمجموعة الضابطة. .المادة لهذهالميكانيكية الخواص بعض عزز السيليكون المطاط مادة إلى النانوية اكاسيد االلمنيوم حبيبات إضافةنستنتج بان االستنتاجات: shefaa f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the role of oral diagnosis 72 the role of 3-dimensional multi-detector computed tomography in the diagnosis of eagle’s syndrome and correlation with severe headache and migraine (iraqi study) shefaa al-nuamee, b.d.s., h.d.d., m.sc. (1) waad haider, m.b.ch.b., d.ga. (2) ali muhssen, m.b.ch.b., f.i.c.m.s. (3) abbod al-razqi, m.b.ch.b, f.i.c.m.s. (4) tariq jassim, m.b.ch.b., d.r.m.r. (5) mona a. al-safi, b.d.s. m.sc. (6) abstract background: the styloid process is a cylindrical bone (protrusion). it situated above the common carotid artery between the external and internal branches immediately proximal to the internal jugular vein and facial nerves. the styloid process varies in length also it may be absent as well as elongated. classically, an elongated styloid process and calcified of stylohyoid ligament causes eagle’s syndrome. the aim of this study was to examine the styloid process using 3 dimensional multi-detector computed tomography (3d-mdct) to detect the presence of eagle’s syndrome that causes severe headache and migraine. materials and methods: one hundred patients with severe headache and migraine were exposed to 3dmultidetector ct with special brain ct in al-karkh general hospital to examine the styloid process. by elongated the field of the brain ct multi-detector downward and using facial volume, the morphological alterations of styloid process and stylohyoid ligament can be discovered. results: thirty four patients (25 females and 9 males) had a problem in the styloid process. seven of them were suffered from elongation of styloid process while 27 patients had fractured styloid process unilaterally or bilaterally conclusion: eagle’s syndrome is one of the important causes of severe headache and craniofacial pain which is detected by special field of brain 3d ct multi-detector. key word: ct multi-detector, styloid process elongation, fracture. (j bagh coll dentistry 2013; 25(special issue 1):7276). introduction the styloid process is a slender outgrowth at the base of the temporal bone, immediately posterior to the mastoid apex. it arises from the inferior surface of the temporal bone at the junction of its petrous and tympanic portions (1,2). it lies caudally, medially, and anteriorly towards the maxillo-vertebro-pharyngeal recess (which contains carotid arteries, internal jugular vein, facial nerve, glossopharyngeal nerve, vagal nerve, and hypoglossal nerve) (1,3). the length of the styloid process was measured on ct scan brain trauma from the skull base to the tip of the styloid process (4,6). in terms of the length, 30 mm was considered as normal and processes longer than 30 mm were considered as elongated (1,2). (1) specialist, department of maxillofacial radiology and surgery, ministry of health. (2) specialist, department of general anesthesia, ministry of health. (3) specialist, department of psychology (4) specialist, department of ent, ministry of health. (5) specialist, department of orthopedic, ministry of health. (6) assistant professor, head of dental department, alyarmok. college university. with the stylohyoid ligament and the small horn of the hyoid bone, the styloid process forms the stylohyoid apparatus, which arises embryonically from the reichert cartilage of the second branchial arch (3). these structures are first formed in cartilage. the cartilage of the styloid process ossifies while the epihyal cartilage, which connects the styloid process and the hyoid bone, is usually reabsorbed. the stylohyoid ligament is formed from the remnants of the epihyal cartilage (2). in some individuals, separate epihyal bone forms when the epihyal cartilage ossifies rather than resorbs (5). ossified stylohyoid ligament occurs as a result of true ossification, rather than calcification due to stress or degeneration, because there is radiographic evidence of ossified stylohyoid ligaments in children (3). eagle described it as a syndrome complex mainly in two varieties. the classical variety presents as pain in the throat, referred to as otalgia and foreign body sensation in the throat (1,4). a second variety is styloid process compressing the carotid artery presenting as carotodynia, headache and dizziness (1,2,4). j bagh college dentistry vol. 25(special issue 1), june 2013 the role of oral diagnosis 73 ct for head injury scans should be done without gantry angulations at increments of 5 to 10 mm from the base of the skull through the hyoid bone. extending the ct examination to include this area will not prolong the scan significantly and may add valuable information about the cervical spine and soft tissues of the neck (6). the anatomical importance is that the styloid process lies between the internal and external carotid arteries and just posterior to the pharyngeal wall in the region of the palatine fossa. three muscles originate from the styloid process, each innervated by a different nerve: 1. the styloglossus, innervated by the hypoglossal nerve; 2. the stylopharyngeal, which is innervated by the glossopharyngeal nerve; and 3. the stylohyoid, innervated by the facial nerve. in addition to the carotid arteries, the styloid process lies closely to five cranial nerves (the facial, glossopharyngeal, vagus, spinal accessory, the hypoglossal and the internal jugular vein (7). the symptoms of the termed carotid artery syndrome by eagle called the styloid process-carotid artery syndrome, which is characterized by dull nagging to sharp pharyngeal pain, headaches and vertigo (5). elongation styloid process of temporal bone related to (8): 1. increase length 2. fracture 3. tension 4. macromolecule 5. long chain 6. synthesis causes of styloid process elongation 1. elongation of macromolecule e.g. in the synthesis of long chains of long fatty acid or in the synthesis of protein source (9). 2. ectopic metastatic calcification in non-osseous soft tissue due to abnormal serum ca, vitamin d and phosphate level metabolism very common in patient with: • scleroderma • dermatomyositis • systemic lupus erythematosis • parathyroid gland • trauma induced (10) several mechanisms for the pain of eagle's syndrome have been proposed. these include: 1. compression of the neural elements, the glossopharyngeal nerve, lower branch of the trigeminal nerve, and/or the chorda tympani by the elongated styloid process (11). 2. fracture of the ossified stylohyoid ligament, followed by proliferation of granulation tissue that causes pressure on surrounding structures and results in pain (12). 3. impingement on the carotid vessels by the styloid process, producing irritation of the sympathetic nerves in the arterial sheath (13). 4. degenerative and inflammatory changes in the tendonous portion of the stylohyoid insertion, a condition called insertion tendinosis. 5. irritation of the pharyngeal mucosa by direct compression by the styloid process. 6. stretching and fibrosis involving the fifth, seventh, ninth and tenth cranial nerves in the post-tonsillectomy period (14). complications of the elongation or fracture styloid process of temporal bone included (15): 1. deep space neck infection. 2. injury to main neurovascular structure. 3. hemorrhage. 4. temporary alteration of speech and swallowing. 5. injury of facial nerve. clinical diagnosis it should be possible to feel an elongated styloid process by careful intraoral palpation, placing the index finger in the tonsillar fossa and applying gentle pressure (16). if pain is reproduced by palpation and either referred to the ear, face, or head, the diagnosis of an elongated styloid process is very likely (17,18). 3dct is a valuable diagnostic tool in the diagnosis of eagle’s syndrome because of its ability to facilitate accurate measurement of the length of the styloid process and explain the problem in detail to patients, all of which make this technique superior to conventional imaging (19). figure 1: elongation the styloid process of temporal bone j bagh college dentistry vol. 25(special issue 1), june 2013 the role of oral diagnosis 74 a b figure 2 (a and b): fractured the styloid process of temporal bone materials and method one hundred iraqi patients with symptomatic severe headache and migraine attended al-karkh general hospital in 2012. detailed medical history and clinical examination were performed by specialist. 3dmdct is acquired to patient having longer than 30mm styloid process or fractured unilateral or bilateral and analyzed by brain trauma ct with elongation the field downward analysis with volume, coronal, sagittal reconstruction (figure 3). figure 3: the criteria for selection of the patients results out of 100 patients examined, 34 patients (25) (74%) females and 9 (26%) males} were diagnosed to have a problem in the styloid process (sp). seven of them were suffering from elongation of sp while 27 patients had fractured styloid process unilaterally or bilaterally (stylohyoid ligament ossificant). table 1 showed the total age group from10-60 years. the most age group suffering from eagle’s syndrome was 31-40 and the less age group was up to 10 years. table 2 and figure 4 revealed the distribution of headache and migraine symptom. the highest percentage was eagle’s syndrome which formed 34% from total patients suffering from ent, cervical vertebra and other causes of craniofacial pain which causes headache and migraine. ent caused only 9% of pain which was the lowest percentage of pain. table 1: total number age groups suffering from styloid process % frequency age (years) 17.6 3 up to 10ys 11.7 4 11-20 29.4 10 21-30 35.9 12 31-40 11.7 4 41-50 2.9 1 51-60 table 2: distribution of the headache and migraine symptoms % no. of patient complaints 9% 9 pain due to ent problem 8% 8 pain due to tmj problem 22% 22 pain due to cervical vertebra 34% 34 eagle’s pain 27% 27 other causes of craniofacial pain figure 4: distribution of the headache and migraine symptoms j bagh college dentistry vol. 25(special issue 1), june 2013 the role of oral diagnosis 75 discussion eagle’s syndrome is an aggregation of symptoms caused by an elongated ossified styloid process and or calcified stylohyoid ligament may be due to fractured of styloid process which can occur unilateral or bilateral. the most common symptom dysphasia, headache, craniofacial or cervical pain (20). the symptomatic elongation of styloid process of temporal bone explained some instances of pharyngeal and ear pains and some headaches and migraine. the main objective in this study was to investigate the real cause of headache which is one of symptoms of eagle’s syndrome in iraqi people by good medical history and palpation with physical examination for all patients to feel the elongated styloid process with careful intraoral palpation by placing the index finger in the tonsiller fossa and applying gentle pressure. if pain is reproduced by referred to the ear, face, or head, the diagnosis of an elongated styloid process or ossification of stylohyoid ligament is very likely in this incidence (17,18). a styloid process of normal length is usually not palpable. this study found there is elongation either hereditary or due to fracture which may causes ossification of stylohyoid ligament. these cause classical form or vascular one and either unilateral or bilateral. this result agreed with ceylan et al. (15). the syndrome of all patients isolated by brain trauma ct scan multi-detectors with increase the fov downward then treated by injection of local anesthesia and corticosteroid. 85% of them got remission. eagles (22) stated that medical students learned something about the styloid process from the anatomy books and cadaver, but never had opportunity to put this information into clinical application during the latter part of medical school, even current journals, radiologists and maxillofacial radiology seeking for cause of headaches and migraine. our results agreed with many findings (3,4,8,13). the normal sp length is approximately 25-30 mm., this study found that about 7% of examined sample suffering from headache due to elongation of styloid process of temporal bone more than 30 mm. this result agreed with other studies (23,24). the result found fracture of styloid process and stylohyoid ligament ossificant causing symptom similar to eagle’s syndrome for patients complain headache and migraine in about 27%; this agreed with carro and nunez (24). guimarães et al. (25) found that age 41-50 years was the more age of suffering from eagle’s syndrome while the present study found that age 31-40 years, as in table 1, is more for complain of headache due to eagle’s syndrome and fractured of styloid process of temporal bone. headache is one of the symptoms associated with eagle’s syndrome of styloid process in about 34% of the cases as in figure 4. this comes in agreement with chourdia (26). females more affected than males, 25 females versus 9 males; this result agreed with karam and koussa (27) and orhan and gűldikes (28). all of the patients examined by 3d-ct brain trauma by elongation the field of view downward. this is a valuable diagnostic imaging tool in patients with eagle’s syndrome that allows clinicians to evaluate the styloid process in spatial geometry, makes accurate length measurements, and explains the problem in detail to patients. all of which make this technique superior to conventional imaging modalities this agreement with savranlar et al. (19). in conclusions, headache and migraine are one of the important symptoms in iraqi people caused by fractured or elongation of the styloid process of temporal bone and 3-d mdct with brain trauma view and elongated field of view downward is more accurate and superior imaging modality for diagnosis headache. references 1. eagle w. elongated styloid process: report of two cases. arch otolaryngol 1937; 25: 584-7. 2. baddour hm, mcanear jt, tilson hb. eagle's syndrome. report of a case. oral surg oral med oral pathol 1978; 46: 486-94. 3. mortellaro c, biancucci p, picciolo g, vercellino v. eagle's syndrome: importance of a corrected diagnosis and adequate surgical treatment. j craniofac surg 2002; 13: 755-8. 4. strauss m, zohar y, laurian n. elongated styloid process syndrome: intraoral versus external approach for styloid surgery. laryngoscope 1985; 95: 976-9. 5. lengelé bg, dhem aj. length of the styloid process of the temporal bone. arch otolaryngol head neck surg 1988; 114: 1003-6. 6. mccorkell sj. fracture of the styloid process and stylohyoid ligament: an uncommon injury. j trauma 1985; 25: 1010-2. 7. shankland we 2nd. anterior throat pain syndromes: causes for undiagnosed craniofacial pain. cranio 2010; 28: 50-9. 8. monsour paj, young wg, barnes pb. styloidstylohyoid syndrome: a clinical update. aust dent j 1985; 30: 341-5. 9. www.rightdiagnosis.com, rd medical, elongation styloid 2012. 10. gokce c, sisman y, sipahioglu m. styloid process elongation or eagles syndrome: is there any role for ectopic calcification. eur j dent 2008; 2: 224-8. 11. guérin ap, london gm, marchais sj, metivier f. arterial stiffening and vascular calcifications in end stage renal disease. nephrol dial transplant 2000; 15: 1014-21. http://www.rightdiagnosis.com j bagh college dentistry vol. 25(special issue 1), june 2013 the role of oral diagnosis 76 12. stylalgia hr. clinical experience of 52 cases. acta otolaryngol 1967; 224:149-155. 13. balasubramanian s. the ossification of the stylohyoid ligament and its relation to facial pain. br dent j 1964; 116: 108–111. 14. balbuena l jr, hayes d, ramirez sg, johnson r. eagle's syndrome (elongated styloid process). south med j 1997; 90: 331-4. 15. ceylan a, köybaşioğlu a, çelenk f, yilmaz o, uslu s. surgical treatment of elongated styloid process: experience of 61 cases. skull base 2008; 18: 289-95. 16. montalbetti l, ferrandi d, pergami p, savoldi f. elongated styloid process and eagle's syndrome. cephalalgia 1995; 15: 80-93. 17. mendelsohn ah, berke gs, chhetri dk. heterogeneity in the clinical presentation of eagle's syndrome. otolaryngol head neck surg 2006; 134: 389-93. 18. woolery wa. the diagnostic challenge of styloid elongation (eagle's syndrome). j am osteopath assoc 1990; 90: 88-89. 19. savranlar a, uzun l, ugur mb, ozer t. threedimensional ct of eagle's syndrome. diagn interv radiol 2005; 11: 206-9. 20. kumar ss, kukkady ma, deena a, ayad aae. role of three-dimensional computed tomography imaging in eagles syndrome. int j radiol 2007; 7(2): doi: 10.5580/d0b. 21. eagle w. elongation styloid process: symptoms and treatment. arch otolaryngol 1958; 64:172-6. 22. www.medhelp.org/posts/neurology/eagle-syndromesymptoms 2007. 23. yetiser s, gerek m, ozkaptan y. elongated styloid process: diagnostic problems related to symptomatology. cranio 1997; 15: 236-41. 24. carro lp, nunez mp. fracture of the styloid process of the temporal bone. a case report. int orthop1995; 19: 35960. 25. guimarães smr, carvalho acp, guimarães jp, gomes mb, cardoso mdm, reis hn. prevalence of morphological alterations of the styloid process in patients with temporomandibular joint disorder. radiology bras 2006; 39: 407-11. 26. chourdia v. elongated styloid process (eagle’s syndrome) & severe headache. indian j otolaryngol head neck surg 2002; 54: 238-41. 27. karma g, koussa s. eagle’s syndrome: the role of ct scan with 3d reconstructions. j neuroradiol 2007; 34: 344-5. 28. orhan ks, gűldikesy, ural hi, cakmak a. elongated styloid process (eagle’s syndrome): literature review and a case report. agri 2005; 17: 23-5. http://www.medhelp.org/posts/neurology/eagle-syndrome ameena.doc j bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 63 risk factors of oral cancer and potentially malignant disorders (pmds) – developing a high / low risk profiling system ameena r. diajil, b.d.s., m.sc., ph.d. (1) peter thomson, b.d.s., mbbs, m.sc., ph.d., ddsc, fdsrcs, ffdrcs, frcs (2) abstract background: oral squamous cell carcinoma (oscc) remains a lethal and deforming disease, with a significant mortality and a rising incidence in younger and female patients. it is thus imperative to identify potential risk factors for oscc and oral pmds and to design an accurate data collection tool to try to identify patients at high risk of oscc development. 14 factors consistently found to be associated with the pathogenesis of oscc and oral pmds. eight of themwere identified as high risk (including tobacco, alcohol, betel quid, marijuana, genetic factors, age, diet and immunodeficiency) and 6 low risk (such as oral health, socioeconomic status, hpv, candida infection, alcoholic mouth wash and diabetes) were stratified according to severity of risk, associated carcinogenicity and clinicopathological effects, using evidence obtained from the international agency for research on cancer (iarc). this review provides understanding of the significance of various risk factors in oral carcinogenesis to help to stratify patients, especially those with potentially malignant disorders, into high and low risk groups. key words: oral cancer, oral potentially malignant disorders and risk factor. (j bagh coll dentistry 2016; 28(1):63-72). introduction the most common oral cancer is oral squamous cell carcinoma (oscc) (1). oscc affects significant numbers of people around the world and represents more than 90% of head and neck cancers (2) with 4-10% of them have been reported in patients below the age of 40 years (3). approximately two thirds of osccs are diagnosed at advanced stages (4).the late diagnosis of a significant number of osccs is mostly attributable to delays in patients seeking treatment, insufficient patient awareness, asymptomatic clinical states and/or inappropriate investigation (5). despite the different treatment modalities for osccs, such as surgery, radiotherapy, chemotherapy, chemo-radiation and immunotherapy (6), the five-year survival rate has not improved in recent years (7). there is thus a vital need for an effective and reliable diagnostic and treatment proceduresthroughan early detection and subsequent effective and less aggressive treatment with lower morbidity and reduced cost (8) as well as better prognosis and better quality of life (9). oral squamous cell carcinoma may arise from potentially malignant disorders (pmds), a term that has been recently introduced by the who to describe a group of disorders that carry an unpredictable risk of malignant transformation (mt) (10). (a)assistant professor. department of oral diagnosis, college of dentistry, university of baghdad. (b)professor. department of oral and maxillofacial surgery, school of dental sciences, newcastle university, uk. pmds are mainly erythroplakia, erythroleukoplakia, leukoplakia, submucous fibrosis,lichen planus and actinic cheilitis as well as inherited cancer syndromes (11). most oral pmds are asymptomatic or present with few symptoms; they are regarded as an intermediate stage between normal and malignant tissues (12) reflecting the multi-step process of oral cancer development (13). one-third of oral pmds has been estimated to progress to cancer (14). thus, it is important to identify patients at risk of developing pmds and to detect these disorders as early as possible, avoiding mt of pmds to oral cancer. the carcinogenesis process may be initiated by carcinogens from lifestyle habits.risk factors for oral pmds are generally believed to correspond to those of osccs (15,16). in this era of globalization, many of these habits have now crossed borders and appear in various areas throughout the world. a risk factor is a variable that might be associated with an increased risk of a disease and it either acts as a disease initiator or promoter (17). early diagnosis and treatment of oral cancer and pmds requires assessment of potential predisposing risk factors (18) and necessitates a partnership between clinicians, pathologists and surgeons. current research efforts are aimed towards early identification of risk factor(s) associated with the process of oral carcinogenesis and to recognize those patients at increased risk (19). one can understand that, patients with pmds may be stratified as either high-risk or low-risk by considering their demography, clinicopathological features, the severity/ location of dysplasia, prej bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 64 existing or the associated risk factors and individual genetic susceptibility. methods study design in this paper, we have attempted to review some of the papers published over a 30 years between 1981-2011, with particular reference to risk factors of oral cancers and pmds. this article reviews lifestyle/habitual and social risk factors associated with osccs and the most common oral pmds. studies published in english-language journals were retrieved by searching pubmed;national library of medicine (nlm) journal literature search system. review articles were also examined to identify additional studies that used biochemical, immunologic tests. thirty-hundredrelative published articleswere identified between the period of 1981 and 2011, from 27 countries; mainly from united states, united kingdom, france, germany and other countries and were comprehensively reviewed. the identifiable factors were classified into high and low risk categories dependent upon sufficientclinical, pathological and laboratory evidence. results and discussion in this paper, fourteen risk factors were identified from one-hundred and twenty-one articles that were selected from 300 retrieved articles from numerous studies examining the relative risk for oral cancer and pmds. we have tried to classify the risk factors as either high or low risk factors with the objective to stratify patients subsequentlyinto high or low risk group. such classification is important to guide a successful treatment plan for each particular patient, depending on patients demography, clinico-pathological presentation and pre-existing or associated risk factors.in addition this aimed elucidating the natural history of oral pmds/oral cancer and evaluating the effectiveness of prevention and opportunistic screening in highrisk (20). the possible carcinogenicity of the risk factors a. high risk factors several risk factors associated with the aetiology of pmds and osccs, but tobacco smoking and alcohol consumption are the two major confirmed risk factors (21). they are independently and synergistically associated with high risk in a dose-dependent pattern (22). followed by six highrisk factors identified from many scientific papers with established or sufficient mechanistic events or evidence. in the current study, the exposure profile of smoking and drinking behaviour including number of cigarettes smoked per day and the units of alcohol consumed per week, history of use were all considered. these exposure parameters were important in relation to patient demography and clinicopathological features of pmds such as oral anatomical site, clinical appearance, size and the presence of epithelial dysplasia. in addition, local factors (intraoral dental prosthesis wear) and the presence of systemic disease such as immunodeficiency, anaemia, diabetes mellitus, hypertension, a familial cancer history and oral candida infection. depending on the sufficient evidence to risk of oral cancer and pmds development, 8 highrisk factors were identified from previous studies (table 1). table 1: high risk factors for oral carcinogenesis high risk factors 1. tobacco 2. alcohol 3. betel quid 4. marijuana 5. genetic factors / individual susceptibility 6. old age 7. dietary factor 8. immunodeficiency 1. tobacco • tobacco use remains the1st most important and preventable risk factor for pmds and oral cancer. • smoked tobacco releases a complicated mixture of thousands of chemicals; of these, more than 60 known chemical carcinogens, and a further 16 chemicals in unburned tobacco, have been identified by the international agency for research on cancer. • oral leukoplakias have been shown to occur up to six times more frequently in smokers than in non-smokers (23) in a dose-response relationship; increased risk is associated with an increased number of cigarettes smoked per day (24) and epithelial dysplasia (25). • approximately, 60% of oral leukoplakias may disappear if patients stop smoking (26), whilst continued exposure to risk factors may result in persistent disease andincreased risk of oral epithelial dysplasia, an important key stage in oral carcinogenesis preceding mt (27) and developing carcinoma which is 50 to 100 times greater in smokers than in the general population (28). j bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 65 • the carcinogenicity of tobacco smoking is related to the tobacco specific nitrosamines (29) that have direct mutagenic effect on the exposed epithelia of upper aerodigestive tract by reacting with dna, forming dna adducts which have subsequently mutational effect on important oncogenes and tumour suppressor genes (p53) ending with cancer development (30). • smokeless tobacco, such as shammah/toombakis a complex mixture consisting of powdered tobacco leaves, slaked lime (calcium carbonate), ash, oil and other materials such as black pepper, mint and flavours (31). • the incidence rate of leukoplakia is the highest in the tobacco habit chewers and lowest in the no habits group,with the rate of mt is the highest among leukoplakias associated with tobacco (32). • the iarc working group on smokeless tobacco hasreported that there is sufficient evidence of the oral carcinogenicity of smokeless tobacco (33).the carcinogenesis may be due to direct contact with lower lip, lower vestibule and floor of the mouth (34). • these carcinogens in experimental in vitro systems affect oral keratinocytes and cause alterations in cell proliferation, apoptosis and activation of inflammatory mediators (35). • one can conclude that tobacco is the principle risk factor for oral carcinogenesis associated with a site preferential localisation and interindividual variation in the activity of enzymes involved in the detoxification of tobacco smoke. 2. alcohol • alcohol consumption is regarded as the 2nd risk factor (36). • alcohol may exert direct toxic effects on the epithelial mucosa (22) through dissolving some of the lipid content of the bilayerphospholipid cell membrane (37) in the superficial regions of the epithelium, increasing its permeability (22) which increases the penetration of carcinogens across the oral mucosa (38). • alcohol can cause reduction in mean cytoplasmic area of oral epithelia for heavy drinker patients (39). • reduction in the endocytosis of oral cells reduces elimination of local carcinogens leading to an increase exposure time to a particular carcinogen. • acetaldehydes are 1st alcohol metabolite (37) are unstable substances produce free toxic radicals damaging the dna or may covalently bonded to dna forming dna adducts (40). this may interfere with dna synthesis and repair (41) revealing the starting step of alcohol carcinogenicity. • alcohol interfere with diet bioavailability (42) causing nutritional deficiency (43). • alcohol ableto reduce immune function through inhibiting the detoxification of carcinogens (44). in addition to ethanol, alcoholic beverage contains othercomponents, volatile and non-volatile flavour and other additives , of these components are nitrosamines, acrylamide, oxidized polyphenols which are classified as a possible carcinogenic to humans, as animal experiments have showed mutagenic activity on oral epithelial cells (45). • a combination of tobacco smoking and alcohol drinking is a strong intensifying risk factor for pmds,epithelial dysplasia andsubsequent malignant transformation (9). • tobacco smoking and excessive alcohol consumption are the major risk factors of epithelial dysplasia and oscc (27). • approximately, 75% of all oral cancers arise in association with tobacco and alcohol use (46). the possibility of strong combined effects of alcohol and tobacco may be due to high levels of acetaldehyde production from both in a synergistic and multiplicative risk effect (47). after a dose of ethanol, salivary acetaldehyde was 2 times higher in smokers without smoking and 7-times higher with active smoking (48). 3. betel quid it is estimated that between 10% and 20% of the world’s population use betel quid and it is regarded as the fourth most frequently consumed psychoactivesubstance after nicotine, ethanol, and caffeine (49). • betel quid cytotoxicity, mutagenicity, and genotoxicity toward different kinds of cells including oral epithelial cells, bone marrow cells, and peripheral blood mononuclear cells (50).this genotoxicity may change the structure of dna, proteins and lipids resulting in antigenicity (51). • betel quid ingredients may induce inflammation of keratinocytes by stimulating the production of prostaglandins, tumour necrosis factor-alpha (tnf-a), interleukin-6, interleukin-8 and granulocyte-macrophage colonystimulating factor in keratinocytes which may intensify tissue inflammation, early j bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 66 cell-mediated immunity and immune surveillance in the chewers (52). • inflammatory responses, new specific antigen, neoantigen, may be formed by the reaction of host tissues with carcinogens which can provoke malignant changes with generation of particular tumour-associated antigens which are subsequently enhance host immunity resulting in proliferation of antigen-specific lymphocytes (53). • the carcinogenicity of betel quid may refer to nitrosation with consequent production of potentially carcinogenic nitrosamines such as, 3-methylnitrosopropionitrile and also generation of reactive oxygen species in the oral cavity due to auto-oxidation of polyphenols contained in areca nut which enhanced by the alkaline ph from slaked lime (54). 4. marijuana (cannabis) due to the fact of similarity in carcinogens and co-carcinogens, between marijuana and tobacco smoke except for nicotine (55), it is more convenient to include marijuana use in the risk assessment of patients with oral cancers and precancer (56). • smoking a few marijuana cigarettes per day has been described to have similar histopathological effects that observed on tracheobronchial epithelium with daily smoking of more than 20 tobacco cigarettes (57). • cannabinoids have been shown to induce cytogenic changes in vivo and in vitro mammalian cells, such as chromosomal breaks, deletions, translocations, error in chromosomal separation, and hypoploidy (58). • delta-9-tetrahydrocannabioid (thc) the principle psychoactive chemical substance in cannabinoids, promotes the growth of tumours in mice with lung cancer by modulation of immune-system responses to the tumour (59). • within the oral cavity, cannabis smoking and/or chewing is associated with changes in the oral epithelia forming ‘’cannabis stomatitis’’ such as leukoedema and hyperkeratosis (60). with chronic use this stomatitis may present as chronic inflammation of the oral epithelium and leukoplakia, which may progress to neoplasia (61). • the higher prevalence of pmds in marijuana users necessitates periodic oral examination of such patients for early identification of pmds. • the synergistic effect between tobacco and marijuana smoke has been observed, suggesting that tobacco and cannabis smoking may enhance the inflammatory responses possibly promoting their carcinogenicities (62). 5. individual susceptibility/ genetic factors/ family history according to ho et al. (63) not all individuals who smoke or drink develop oscc; individual genetic susceptibility, differences in carcinogenmetabolizing enzyme function, mutagen sensitivity, apoptosis, and chromosomal aberrations either alone or in combination have been hypothesized to modify the risk of oscc. nearly all carcinogens and pro-carcinogens require activation by metabolizing enzymes. similarly, detoxifying enzymes exist and deactivate carcinogens as well as their intermediate by-products; together these enzymes are termed xenobiotic-metabolizing enzymes. genetic polymorphisms of these enzymes can modify an individual’s response to carcinogens and hence the carcinogenic potential of such exposures (63). • several genetic events altering the normal functions of oncogenes and tumour suppressor genes leading to cellular phenotypic changes that can increase cell proliferation, loss of cell cohesion (64). • polymorphisms of carcinogen-metabolizing enzymes may affect an individual’s susceptibility to risk factors and subsequent occurrence of oral cancer (40). • there is growing evidence from case control studies that consider family history as a risk factor for oral cancer (65). the evidence is mainly based on the fact that more than 50% of oral cancer patients have not been exposed to the major identifiable carcinogens alcohol, tobacco or betel quid (64). also young age onset with unusual high incidence of familial oral cancer cases are more likely to support the general acceptance of genetic individual variations (66) in the development of oral cancer (67). • risk assessment requires an accurate and comprehensive family history “genetic pedigree” which is useful in the management plan including prevention, risk reduction and cancer screening. 6. old age • the majority of osscs and premalignant disorders are seen in patients between the age of 50 and 80 year (68) and peaks in the 70s (69), whereas it is less common in patients under the age of 50s (70). • telomeres; ”'dna protein complexes that cap the chromosomal ends promoting j bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 67 chromosomal stability” (71) may help to understand and explain the relation between ageing and risk of tumour development (72).telomere length decreases may contribute to neoplastic transformation, replicative senescence or apoptosis resulting in early onset of diseases such as oral cancer (73). • the relation between cancer and age may be explained as a result of long periods of carcinogenic exposure with mixed genetic and environmental components (74). thus periodic screening for all adult patients over 40 should be conducted every 6 months to exclude any abnormal oral changes related to the aging process. 7. dietary factors according to popkin (75), deficiencies in fruit, non-starchy vegetable and carotenoid food is associated with 10-15% of oral cancer cases. whereas, in a previous study higher percentages of oral cancers of 65% with low vegetable and low fruit intake has been reported (76). boccia et al. (77) found that higher intake of fruit and vegetable, even with alcohol drinking and tobacco smoking could prevent the development of head and neck sccs by approximately 1/4. regarding the risk of oral premalignant lesions, maserejian and co-workers (78) showed that increase consumption of fruits, particularly citrus fruit in men reduce the risk of oral premalignant even with presence of tobacco smoking which is a well-known risk factor for oral pmds. • raw fruit and vegetable provide mechanical cleansing effect for oral cavity with the benefit of many properties in planted food such as dilution action, anti– oxidant and anti carcinogenic properties of micronutrients such as vitamins a,c, e, carotenoid, flavoniod, phytosterol, folates and fibres which are crucial for neutralizing the carcinogenic effects of tobacco, alcohol, and betel quid (79). • fast, fermented, canned processed food having high fat content that generates polycyclic aromatic hydrocarbon during high temperature cooking and this hydrocarbon can cause cancer in laboratory animals (80). • heterocyclic amines such as benzopyrene generated from burned amino acids and other substance in meat found to be association the risk of oral cancer (80). 8. immunodeficiency genetic immunodeficiency has been implicated in the aetiology of oral cancer and pmds in young individuals. inherited cancer syndromes such as xerodermapigmentosum, fanconi's anaemia and bloom’s syndrome are associated with an increased incidence of oral cancer (81). acquired, induced immunodeficiency such as in organ transplant patients where the drugs are used to prevent organ rejection; several studies have shown increased incidence of postorgan transplantation cancer involving head and neck cancers and oral pmds. it has been reported that post-transplantation tumours increased by 2 to 4fold compared with non-transplanted population (82). in kidney transplantation patients, lip and skin cancers are found to be increased by 35-fold and head and neck cancer increased by 4 folds (83). • oral leukoplakia has been found to be the third most commonly diagnosed lesions in patients underwent sold organ transplantation with a prevalence of 10.7% (84). the presence of leukoplakia in normal control increases the risk of oral cancer development by 5-fold compared with a 50-fold higher in immunosuppressed transplant patients (85). • impaired immunosurveillance due to prolonged immunosuppression therapy which may continue for several years treating chronic graft versus host disease, emerges as a major factor in the elevated incidence of tumours in transplanted patients (86). b. low risk factors table 2 however, showssixlowrisk factors have been identified from many studies with the majority of their results have shown inconsistency/controversy or with limited evidencefor the oral carcinogenesis. accordingly, these factors have been considered as low risk for the development of oral cancer and pmds. table 2: low risk factors for oral carcinogenesis low risk factors 1. oral health 2. socioeconomic status 3. hpv 4. candida albicans 5. alcoholic mouth wash 6. diabetes mellitus 1. oral hygiene • poor oral hygiene associated with increased number of microorganisms from supragingival dental plaque, may display the association between poor oral hygiene and oral cancer, as an independent risk factor due to increase acetaldehyde concentration in saliva after alcohol drinks (87). j bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 68 • acetaldehyde may cause point mutations in human lymphocytes, sister chromatid exchanges and cross chromosomal aberration or even interference with the dna-repair machine (88). furthermore, acetaldehyde may interact with dna forming adducts which may lead to mutations (41). • routine dental care with regular dental visits as an indicator of a good oral health may reduce or prevent the exposure to some carcinogens, in addition to regular screening programs for prevention (89) and treatment as a part of the long-term standardised care (90). oral hygiene status should be involved among the strategies of oral pmds preventive and control programmes. 2. socioeconomic status • low socioeconomic standard patients having low income are almost under stress which needs coping mechanisms such as tobaccosmoking/ chewing and alcohol consumption (91),which are established risk factors. • as preventive measures, all the socioeconomic factors that can be identified as real risks for oral cancer and pmds need to be improved by effective measures to reduce inequalities between people in society through either local or national authorities or the who commission. 3. human papilloma virus • it is well documented that hpvs are implicated in the pathogenesis of cervical cancer and although more than 95% of human cervical cancers are associated with hpv 16 and 18 (92); the association with the head and neck cancer remains controversial. • the carcinogenicity of the highrisk hpvs is believed to be mostly through two viral oncogenes e6 and e7 which are regarded as an indicator of hpv positive cancers, changing apoptosis that is essential for hpv-infection, to avoid the immunological response (93). these two proteins have no intrinsic activities of enzymes, but they are able to interact directly and indirectly with twokey tumour suppresser proteins p53 and retinoblastoma. this may affect their ability to stimulate dna repair or apoptosis interfering with the cell cycle control and promote carcinogenic processes (94). 4. candida albicans • nitrosamine compounds produced by candida species may directly or with other carcinogens, activate specific proto-oncogenes initiating the development of development of oral neoplasia (95). • in spite of the general acceptance of an association between candida infection and the occurrence of oral epithelial dysplasia, the possible role of yeast in oral carcinogenesis is still unclear and further studies in this area of research are warranted. 5. alcoholic mouth wash • the majority of studies have shown inconsistent results or negative relations due to difficulties in separating the independent effects of mouthwash from smoking, drinking effects and also to the exact effects of other mouthwash constituents (96). furthermore, these studies suffer from limitations such as underreporting of mouthwash use by individuals and the use of different mouthwash types, varying alcohol content, duration of use and time retained in the mouth leading to inaccurate results. • the potential mechanisms are;ethanol altering the cell surfaces of oral mucosa leading to increase their susceptibility to the effects of carcinogens by increasing their permeability, or alcohol may dissolves carcinogens and increases their absorption by tissue enhancing the carcinogenic mechanism subsequently (97). 6. diabetes mellitus • diabetic patients may develop a progressive atrophy of oral mucosa due to decreased salivary secretion and lower salivary ph (98). this may increase oral disorders, such as glossitis and cheilitis (99) and also can increase the permeability of the oral mucosa to different carcinogens as a result of loss of normal protective barrier (100). • tumorogenisity may be directly mediated by insulin receptors in target cells or might be due to related changes in endogenous hormone metabolism (100). • insulin deficiency results in reduction of insulin receptor substrate-1 (101) and changes in cytoskeleton leading to reduction in cell adhesion by affecting focal adhesion kinase pathways (102). this is probably a starting step towards neoplasia and subsequent oral cancer development (101). • further, insulin can stimulate the synthesis and biologic activity of insulin-like growth factor1 which promotes cell proliferation and inhibit apoptosis (103). it has been indicated that the effect of insulin-like growth factor-1 might j bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 69 be connected to p53 mutations, which are frequently seen in head and neck tumours (104). • elevate blood glucose levels and protein breakdown may lead to excessive formation of free radical (99) causes imbalance between production of free toxic radicals and biological system due to reduction of antioxidant activity of enzymes (100). this may cause dna damage and subsequent promotion of carcinogenesis (105). • to explain the exact associated mechanisms, future studies should take in consideration information such as the type of diabetes, type of treatment, age of onset of diabetes, duration between the onset of diabetes and the development of pmds (104); to determine if the association is related to characteristics of the diabetic state or to the treatment agents or to other associated risk factors. as conclusions 1. the identifiable risk factors are either high or low risk categories depending upon sufficient or limited (controversial) evidence for oral carcinogenesis. 2. high risk patients should be identified by taking very details medical, lifestyle history and family history.this is throughdetailed risk factor data collection sheet designed to stratify patients into high or low risk group to aid future management; figure 1. 3. assessment of the risk factors in pmds patients may help to identify patients at higher risk of unfavourable clinical outcomes who require more extended care and surveillance. references 1. rapidis ad, et al. major advances in the knowledge and understanding of the epidemiology, aetiopathogenesis, diagnosis, management and prognosis of oral cancer. oral oncol 2009; 45(4-5): 299-300. 2. warnakulasuriya s. global epidemiology of oral and oropharyngeal cancer. oral oncol 2009; 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24(3): 35362. j bagh college dentistry vol. 28(1), march 2016 risk factors of oral diagnosis 72 data collection sheet patient hospital no. patient study no. first presentation time sex female male date of birth occupation civil status married divorced single widowed medical history 1) immunodeficiency 2) diabetes 3) hypertension 4) anaemia 5) candidal infection 6)human papilloma virus other medical conditions risk factors tobacco smoking 1) current smoking 2) ex-smoking 3) non-smoker history of smoking (years) cigarettes per day alcohol drinking 1) current drinker 2) ex-drinker 3) non-drinker history of drinking units per week diet prepared food fresh food/vegetables familial cancer history father mother 1st relative 2nd relative oral hygiene good bad mouth wash use user non-user type of mouth wash oral prosthesis none upper or lower denture full denture crown and bridge figure 1: recommended risk factor assessment case sheet hamid f.doc j bagh college dentistry vol. 25(4), december 2013 the effect of smear restorative dentistry 5 the effect of smear layer on push-out bond strength to dentin of bioceramic sealer (in vitro study) hamid abbas hamid, b.d.s. (1) abdul-kareem jassim al-azzawi, b.d.s., m.sc. (2) abstract background: sealers should demonstrate adhesive properties to dentin, decreasing the chance of endodontic treatment failure. increased adhesive properties to dentin may lead to greater strength of the restored tooth, which may provide greater resistance to tooth fracture and clinical longevity of an endodontically treated tooth. the aim of this study was to evaluate the shear bond strength of bioceramic iroot sp sealer, ah plus sealer and apexit plus sealer in absence or presence of smear layer using push out bond strength test. materials and methods: sixty straight single roots of the mandibular premolars were selected for this study. all canals were instrumented using protaper rotary instruments to achieve tapered canal walls, instrumentation was done with copious irrigation of 5.25% sodium hypochlorite. roots were randomly divided into three groups according to the type of sealer used (twenty teeth for each group): group a: apexit plus + gutta percha, group b: ah plus sealer + gutta percha, group c: iroot sp sealer + gutta percha .then groups were subdivided according to types of final irrigation into two subgroups. groups (a1, b1, and c1) were irrigated with 5 ml of 5.25% naocl for 1 minute while groups (a2, b2, and c2), the smear layer was removed with 5 ml of 17% edta for 1 minute. all groups were rinsed with distilled water and then obturated with cold lateral condensation technique, the roots then stored in moist environment at 37°c for one week. the roots were embedded in clear acrylic resin and three horizontal sections were prepared at a thickness of 1 mm ±0.1 in the apical, middle and coronal parts of each root. the test specimens were subjected to the push-out test method using a universal test machine that carried 1-mm, 0.5mm and 0.3-mm plungers for coronal, middle and apical specimens, respectively. the loading speed was 0.5 mm/ min. the computer showed the higher bond force before dislodgment of the filling material. these forces were divided by the surface area to obtain the bond strength in mpa. results: the results showed that the bond strengths of iroot sp and ah plus were significantly higher than those of apexit plus, but there was no significant difference between the bond strength of iroot sp and ah plus.in terms of root segments, the bond strengths in the middle specimens and the apical specimens were higher compared with the bond strengths in the coronal specimens. conclusion: the presence or absence of smear layer did not significantly affect the bond strength of bioceramic filling materials. keywords: bioceramic sealer, smear layer, push out test. (j bagh coll dentistry 2013; 25(4):5-11). introduction the introduction of bioceramic technology is considered a dramatic change in endodontic obturation. the introduced iroot sp (innovative bioceramix, vancouver, canada) is a premixed, ready-to-use injectable and hydrophilic cement paste. it is composed of calcium phosphate, calcium silicate, calcium hydroxide, zirconium oxide, filler, and thickening agents. one of its advantages is its ability to form hydroxyapatite during the setting process and ultimately create a bond between dentinal wall and the sealer. it has been shown that iroot sp is equivalent to ah plus sealer in apical sealing ability, furthermore, it was demonstrated that i root sp was significantly less toxic than ah plus 1,2. instrumentation of root canals produces a smear layer consisting of inorganic and organic components. the mechanical interlocking of the sealer plug inside the tubules following smear layer removal has been suggested to improve retention of the material, which might improve the sealing ability 3. (1) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. on the other hand, it has been shown that the bond strength of some sealer cements to dentin was better in the presence of smear layer 4. furthermore, because the smear layer contains moisture and might act as a coupling agent, thereby improving the adaptation of hydrophilic materials to the root canal wall. the removal of smear layer might have a negative effect on hydrophilic root canal sealers such as bc sealer 5. the push-out test provides a better evaluation of bonding strength than the conventional shear test; because when using the push-out test, fracture occurs parallel to the dentine–bonding interface, which makes it a true shear test for parallel-sided samples 6,7. interfacial strength and dislocation resistance between the root filling material and the intra-radicular dentine have been evaluated using thin-slice push-out tests 8-10. materials and methods sixty freshly extracted mandibular premolars with straight single roots and close apices were used in this study. the age of patients range between (18-48) years but the reason of extraction and gender was not considered. after extraction, all teeth were stored in 0.1% thymol solution at j bagh college dentistry vol. 25(4), december 2013 the effect of smear restorative dentistry 6 room temperature. any periodontal remnants or soft tissues were removed by periodontal curette and root surfaces were verified with magnified eye lens (10x) and light cure device for any defects and cracks. after the length of root was determined by digital calliper and marker to 14 mm from apex to cemento-enamel junction, the root was sectioned perpendicular to its long axis by using diamond disc in a straight hand piece with water coolant to facilitate straight line access for canal preparation and filling procedure, also to eliminate the variables in access preparation and get flat reference point for measurement 11. the pulpal tissue was removed by using barbed broach and copious amount irrigation of 5.25% naocl. the potency of canals was verified by insertion of no.15 k file into canal until it was visualised at apical foramen. the exact working length was established by subtracting 1mm from this measurement which is 13 mm. a silicon rubber base (heavy-body) was mixed (base and catalyst) according to manufacturer instruction and inserted in plastic containers then the sectioned root was inserted inside the rubber base. heavy body was left to set forming a small block to facilitate handling of the roots during instrumentation and obturation technique. the roots were instrumented by rotary protaper (niti) system from sx-f3. all instrumentation was carried out according to manufacturer's instructions and completed in a crown-down manner using a gentle in-and-out motion. instruments were withdrawn when resistance was felt and changed for the next instrument. the root was flooded with 5 ml of 5.25%naocl solution delivered with needle tip gauge 27 placed within apical third passively without bending and washed after each file. sample grouping the roots were randomly divided into three groups (n=20) according to types of root canal sealer used: group a. apexit plus root canal sealer obturation. group b. ah plus root canal sealer obturation. group c. i root sp root canal sealer obturation. then each group was subdivided into two subgroups (n=10) according to the method of final irrigation. sub groups a1, b1 and c1; the roots canals were irrigated with 5 ml of 5.25% naocl for one minute and then irrigated with 5 ml of distilled water.sub groups a2, b2 and c2; the root canals were irrigated with 5 ml of 17% of edta for one minute and 5 ml of 5.25%of naocl one minute and then irrigated with 5ml of distilled water. all groups were obturated by lateral condensation technique. group a: the samples were obturated with gutta percha and apexit plus root canal sealer. the sealer was mixed according to the manufactures instructions by one press on handle of cartridge, equal amounts of base and activator were dispersed and mixed on clean and dry glass slab. the mixture had homogenous creamy consistency that stringed out when elevated with cement spatula over glass slab for one inch. each canal was dried with paper point size f3. the k type master cone of gutta percha size 30 was adjusted to working length with tug back. protaper absorbent paper point size f3 was dipped in sealer and coated the canal walls by counter clock wise rotation. the tip of master gutta percha cone was dipped into the sealer and inserted to correct full working length. the previously checked finger spreader size 20 was inserted between master cone and the canal wall using firm (apical only) pressure to within (1-2mm) from working length. the spreader was moved apically with a 180⁰ clockwise-anticlockwise movement. the tapering of spreader was a mechanical force that laterally compresses and spread gutta percha creating space for additional accessory cones size 15 and 20. when the spreader did not inter more than 2mm ,excess gutta percha was removed with heated instrument to level 1mm higher than the coronal end of the root and vertically condensed with root canal plugger so gutta percha was obturated the entire canal up to canal terminus. the load applied during condensation ranged from 1.5-2 kg determined by weight balance 12. group b: the samples in this group were obturated with gutta percha and ah plus root canal sealer. ah plus sealer was mixed according to the manufactures instructions, by mixing equal amounts (1:1) of paste a and paste b on glass slab with spatula. the mixture had homogenous consistency that stringed out at least 1 inch when spatula was raised slowly from glass slab and then the canals were obturated with the same manner used for group a. group c: the samples in this group were obturated with gutta percha and iroot sp sealer (bioceramic sealer). after removing the syringe cap, attached an intra canal tip securely. insert the tip of the syringe into apical third of root canal, filling the root canal while withdrawing the intra canal tip and then place gutta percha points inside the root canal then complete obturation in same manner in previous groups. after obturating the teeth samples of all groups, the gutta-percha was removed at 1 mm below the orifice. then the canal orifice was j bagh college dentistry vol. 25(4), december 2013 the effect of smear restorative dentistry 7 sealed with glass inomer cement as temporary filling to serve as a barrier to the ingress of fluids. all obturated roots of all groups were removed from impression material and wrapped in saline moistened gauze in closed plastic vial allowing the sealer to set for 7 days at 37°c in an incubator 13,14. then the roots were embedded in clear acrylic resin 15. metal frame of (length 70mm, width 60mm and height 30mm) containing three cylindrical holes of (diameter 12 mm * height 25mm) was used into which the prepared acrylic was loaded. before loading the mold with acrylic, the coronal end of the roots was fixed on the face of the end rod of the dental surveyor with a sticky wax. with the aid of dental surveyor the roots were centrally located within the acrylic blocks to ensure that the sectioning would be perpendicular to the long axis of the roots.the acrylic was prepared by mixing powder and liquid in a porcelain jar. the material was left undisturbed for few minutes until it reached the workable stage and loaded into the metal mold, the rod of the surveyor with the root fixed on its face was pushed into the acrylic with gentle pressure to allow the complete embedding of the root into the acrylic and to allow the escape of the excess material. the metal frame was taken from surveyor and the material was allowed to cure under cool water at 20°c, which was necessary to compensate for the anticipated rise in the temperature of the samples subsequent to the exothermic curing reaction of the cold cure resin. the acrylic blocks were allowed to cure completely for at least 30min as recommended by the manufacturers 16. root sectioning was done after complete curing of the acrylic mold, the metal mold was open. the excess acrylic was cut off using diamond disk mounted on straight hand piece and engine with a rotation speed regulator, the hand piece was fixed in a cutting device. the root was cut horizontally with flow cold water (19-25°c) to minimize smearing 16. to get three sections of 1mm in thickness coronal, middle and apical, the cuts were made at 2,6,9 mm from coronal reference point respectively. push-out test was performed by applying a compressive load to the apical aspect of each slice via a cylindrical plunger mounted on tinius-olsen universal testing machine managed by computer software. samples were examined under the nikon metallurgical microscope (magnification 50x) and pictures of both sides of each section are taken with digital camera which was connected with microscope, and measurements calculated using lucia g software analysis program . the obturated area of the section at each level was measured from the apical side to determine the size of punch pin 17. three different sizes of punch pins were used, 1 mm, 0.6mm, and 0.3mm diameter for the coronal, middle and apical slices respectively. the punch pins should provide almost complete coverage over the main cone without touching the canal walls and sealer 13,17. the root filling in each section subjected to loading using a universal testing machine (wdw50) at a speed of 0.5 mm / min in an apical-coronal direction until the first dislodgment of obturating material and a sudden drop along the load deflection. the maximum failure load was recorded in newton (n) and was used to calculate the push-out bond strength in mega-pascals (mpa) according to the following formula 18: ( ) the adhesion (bonding) surface area of each section was calculated as: (πr1 + πr2) *l. l was calculated as π = 3.14; r1 = coronal radius, in mm; r2 = apical radius, in mm; h = thickness of section in mm, l = adhesion area. anova and student t-test were performed as statistical analysis for push-out bond strength. results mean values of push-out bond strength & standard deviations for all groups presented in (table 1). both the highest and the lowest mean values for sealer push-out bond strength were seen at apical level of iroot sp sealer without smear layer group c2 (4.889) and middle level of apexit plus sealer without smear layer group a2 (1.125) respectively. the rest mean values for study groups were fluctuating between these values. to compare among the six groups systems at each level, anova test was preformed to identify the presence of statistically significant differences for sealer push-out bond strength among different groups within each level. highly significant differences were found in a1, b1, b2, and c2 at all levels while significant difference was shown in a2 while no significant difference was seen in c1 table (2). the least significance difference test (lsd) was performed to evaluate the significant differences between six groups at each level and the results listed in table (3) and showed the followings: highly significant differences between three levels in group a1 (apexit plus sealer with smear layer). j bagh college dentistry vol. 25(4), december 2013 the effect of smear restorative dentistry 8 highly significant difference between coronal and middle level while no significant differences between coronal and apical, and between middle and apical levels in group a2 (apexit plus sealer without smear layer). significant differences between coronal and middle, and between middle and apical levels while highly significant differences between coronal and apical levels in group b1 (ah plus sealer with smear layer). no significant differences between coronal and middle, and between middle and apical levels while highly significant differences shown between coronal and apical levels in group b2 (ah plus sealer without smear layer). no significant differences between coronal and middle, and between middle and apical levels while significant differences appear between coronal and apical levels in group c1 (iroot sp sealer with smear layer). highly significant differences between coronal and middle and between coronal and apical levels while no significant differences between middle and apical levels in group c2 (iroot sp sealer without smear layer). student t test showed: no significant differences in push out bond strength at middle and apical levels in presence or absence smear layer of apexit plus sealer except at coronal level highly significant difference. no significant differences in push out bond strength at all levels in presence or absence smear layer of ah plus sealer. no significant differences in push out bond strength at coronal and apical levels in presence or absence smear layer of iroot sp sealer except at middle level significant difference. discussion the adhesive strength of root canal sealers has been examined by various methods that include shear bond strength, microtensile bond strength, and pushout bond strength testing. the push-out test is easy to reproduce and interpret and provides a realistic assessment of bond strength to dentin even at low levels 13. effect of sealer type on bond strength the result of present study showed the highest mean value of push –out bond strength in group c2 that used iroot sp sealer with removed smear layer (table 1) and when compared with other sealers with same method of irrigation, there was very highly significant difference between group c2 iroot sp sealer and group a2 apexit plus sealer, significant difference between group c2 and group b2 ah plus sealer. these results are in agreement with the results of other studies 19,20, which conducted to evaluate and compare the fracture resistance of roots obturated with various contemporary canal-filling systems and it was concluded that the innovative bioceramic-based sealer (iroot sp) may have the potentiality to strengthen endodontically treated teeth to a level comparable to that of intact teeth. this could be attributed to the nature of iroot sp sealer being a true self adhesive material that would form a chemical and mechanical bond with dentin through the production of hydroxyapatite during setting when the material is exposed to a moist environment as that present within the dentinal tubules. in addition, the bioceramic sealer is hydrophilic, possessing a low-contact angle that would allow the sealer to spread easily over the canal wall providing adaptation and good hermetic seal through mechanical interlocking. in addition, the extremely fine particle size and the optimal premixed consistency introduced with a capillary tip introductory system might have enhanced its penetration to the full length of the canal. furthermore, zirconium oxide, one of the constituents of the iroot sp sealer, has been reported to possess high fracture toughness, tensile strength, and lower young’s modulus 1,19,20. the result of this study disagreed with 14,22 who found that there was no significant difference between ah plus and bioceramic sealer used with gutta percha, this may be related to difference in method of obturation, 22 in his study the canal was obturated by single cone technique in addition a slice thickness used in push out bond strength was 2mm while 14 measured only the push out bond strength of ah plus and bioceramic sealer at middle third. in this study when the smear layer left at the apical area, group b1 ah plus and group c1 iroot sp showed a significantly higher values than group a1 apexit plus, but there was no significant difference between b1 ah plus and c1 iroot sp groups, this coincide with the findings of 14,22-24 no significant difference between bc sealer and ah plus push out bond strength. the high bond strength of ah plus may be explained by the formation of a covalent bond by an open epoxide ring to any exposed amino groups in collagen 25. other investigations have shown a high-quality properties with epoxy resin–based sealers, including very low shrinkage while setting, long-term dimensional stability, flow, and long setting time, ah plus sealer penetrates deeper into the surface microirregularities 26. j bagh college dentistry vol. 25(4), december 2013 the effect of smear restorative dentistry 9 effect of root section level on bond strength the push-out bond strengths in the middle and apical specimens were significantly higher than those of the coronal specimens in group c1 iroot sp sealer and highly significant in group c2. there were no significant differences between the push-out bond strengths in the middle and apical specimens in both groups c1 and c2. the result of this study is aligned with 24 who assessed the push-out bond strength of two new calcium silicate-based endodontic sealers in the root canals of extracted teeth iroot sp and mta fillapex sealers. three horizontal sections were prepared coronal, middle and apical. their result showed that there were no significant differences between the bond strengths in the middle and apical slices. some authors have reported the bond strengths of different sealer to dentin were higher in the apical one-third than in the coronal third 27-29. the higher bond strengths in the middle and apical specimens could be related to deeper sealer penetrations because of higher lateral condensation forces in apical third than coronal third and also could be a result of irregular dentine and devoid of tubules in apical part of roots which increase surface area of adhesion 24,30. effect of smear layer removal on bond strength this study showed that there were no significant differences in push out bond strength at coronal and apical levels in presence or absence of smear layer in iroot sp sealer groups except at middle level a significant difference. this result agree with the result of other studies 14,31. the open tubules and the absence of smear layer do not improve adhesion of endodontic sealers. the authors suggest that perhaps the open tubules increase the stress at the sealer dentin interface and that the calcium and phosphate-rich smear layer and plugs are potential sites of sealer adhesion 31. shokouhinejad et al. 14 compared the bond strength of a new bioceramic sealer (endosequence bc sealer) and ah plus in the presence or absence of smear layer, and they concluded that the presence or absence of smear layer did not affect the bond strength of endosequence bc sealer. they explained that it may be due to bioceramic sealer includes a similar composition to white mta 1, and some studies revealed that removal of the smear layer caused significantly more microleakage in the root canals and root end cavities filled with mta 5,32.so within the limitation of this in vitro study, can be concluded the presence or absence of smear layer did not significantly affect the bond strength of filling materials, the bond strengths of iroot sp and ah plus were significantly higher than those of apexit plus, no significant difference between ah plus and i root sp groups in the presence of smear layer at the apical specimens and in terms of root segments, the bond strengths in the middle specimens and the apical specimens were higher compared with the bond strengths in the coronal specimens. references 1. zhang w, li z, peng b. assessment of a new root canal sealer’s apical sealing ability. oral surg oral med oral pathol oral radiol endod 2009; 107: e79– 82. 2. zhang w, li z, peng b. effect of iroot sp on mineralization related genes expression in mg63 cells. j endod 2010; 36:1978–82. 3. sen bh, piskin b, baran n. the effect of tubular penetration of root canal sealers on dye microleakage. int endod j 1996; 29: 23–8. 4. lalh ms, titley k, torneck cd, friedman s. the shear bond strength of glass ionomer cement sealers to bovine dentine conditioned with common endodontic irrigants. int endod j 1999; 32: 430–5. (ivsl) 5. yildirim t, orucoglu h, cobankara fk. long-term evaluation of the influence of smear layer on the apical sealing ability of mta. j endod 2008; 34: 1537–40. 6. drummond jl, sakaquchi rl, racean dc, wozny j, steinberg ad. testing mode and surface treatment effects on dentin bonding. journal of biomedical materials research 1996; 32: 533–41. 7. ureyen kaya b, keceli ad, orhan h, belli s. micropushout bond strengths of gutta-percha versus thermoplastic synthetic polymer-based systems – an ex vivo study. int endod j 2007; 41: 211–8. (ivsl) 8. gesi a, raffaelli o, goracci c, pashley dh, tay fr, ferrari m. interfacial strength of resilon and guttapercha to intraradicular dentin. j endod 2005; 31(11): 809-13. 9. skidmore lj, berzins dw, bahcall jk. an in vitro comparison of the intraradicular dentin bond strength of resilon and gutta-percha. j endod 2006; 32: 963–6. 10. ungor m, onay eo, orucoglu h. push-out bond strengths: the epiphanyresilon endodontic obturation system compared with different pairings of epiphany, resilon, ah plus and guttapercha. int endod j 2006; 39(8): 643-7. 11. pitts dl, natkin e. diagnosis and treatment of vertical root fracture. j endod 1983; 9: 338-46. 12. allison d, webber c, walton r. the influence of the method of canal preparation on the quality of the apical and coronal obturation. j endod 1979; 5: 298304. 13. fisher ma, berzins dw, bahcall jk. an in vitro comparison of bond strength of various obturation materials to root canal dentin using a push-out test design. j endod 2007; 33(7): 856-8. 14. shokouhinejad n, gorjestani h, nasseh aa, hoseini a, mohammadi m, shamshiri ar. push-out bond strength of gutta-percha with a new bioceramic sealer in the presence or absence of smear layer. aust endod j 2011; 37(2):16. 15. eguchi ds, peters do, hollinger jo, lorton l. a comparison of the area of the canal space occupied by gutta percha following four gutta percha obturation j bagh college dentistry vol. 25(4), december 2013 the effect of smear restorative dentistry 10 techniques using procosol sealer. j endod 1985; 11: 166-75. 16. gencoglu n, garip y, bas m, samani s. comparison of different gutta-percha root filling techniques: thermafil, quick-fill, system b, and lateral condensation. oral surg oral med oral pathol oral rad endod 2002; 92: 333-6. 17. jainaen a, palamara j & messer h. push-out bond strengths of the dentine– sealer interface with and without a main cone. int endod j 2007; 40(11): 882 90. (ivsl) 18. nagas e, cehreli zc, durmaz v. regional push-out bond strength and coronal microleakage of resilon after different light-curing methods. j endod 2007; 33: 1464-8. 19. ghoneim ag, lutfy ra, sabet ne and dalia m. fayyad dm. resistance to fracture of roots obturated with novel canal-filling systems. j endod 2011; 37(11):1590-2. 20. ulusoy ö, nayır y, darendeliler-yaman s, effect of different root canal sealers on fracture strength of simulated immature roots. oral surg oral med oral pathol oral radiol endod 2011; 112: 544-7. 21. candeiro g, correia f, duarte m, siqueira d. evaluation of radiopacity, ph, release of calcium ions, and flow of a bioceramic root canal sealer. j endod 2012; 36(6): 842-5. 22. naser sh. pushout bond strength of different root canal obturation materials. a master thesis, department of conservative dentistry, al mustansiriyah university, 2012. 23. ersahan s, aydin c. dislocation resistance of iroot sp, a calcium silicate– based sealer, from radicular dentine. j endod 2010; 36(12): 2000-2. 24. sagsen b, ustu¨ n y, demirbuga s, pala k. push-out bond strength of two new calcium silicate-based endodontic sealers to root canal dentine. int endod j 2011; 44(12): 1088-91.(ivsl) 25. nunes vh, silva rg, alfredo e, sousa md, sousa yt. adhesion of epiphany and ah plus sealers to human root dentin treated with different solutions. braz dent j 2008; 19(1): 46-50. 26. flores d, rached-júnior f, versiani m1, guedes d, sousa-neto m, pécora j. evaluation of physicochemical properties of four root canal sealers. int endod j 2011; 44(2): 126-35. (ivsl) 27. gaston ba, west la, liewehr fr, fernandes c, pashley dh. evaluation of regional bond strength of resin cement to endodontic surfaces. j endod 2001; 27: 321– 4. 28. mannocci f, pilecki p, bertelli e, watson tf. density of dentinal tubules affects the tensile strength of root dentin. dent mater 2004; 20: 293–6. 29. muniz l, mathias p. the influence of sodium hypochlorite and root canal sealers on post retention in different dentin regions. oper dent 2005; 30: 533–9. 30. mjor ia, smith mr, ferrari m, mannocci f. the structure of dentine in the apical region of human teeth. int endod j 2001; 34: 346–53. (ivsl) 31. saleh im, ruyter ie, haapasalo mp, orstavik d. adhesion of endodontic sealers: scanning electron microscopy and energy dispersive spectroscopy. j endod 2003; 29(9): 595-601. 32. yildirim t, er k, tas¸demir t, tahan e, buruk k, serper a. effect of smear layer and root-end cavity thickness on apical sealing ability of mta as a rootend filling material: a bacterial leakage study. oral surg oral med oral pathol oral radiol endod 2010; 109: e67–72. table 1: mean values of push-out bond strength and standard deviations at three levels in mpa. group level mean ±sd a1 coronal 2.8892 0.085815 middle 1.2567 0.31708 apical 1.734 0.406251 a2 coronal 1.7935 0.49572 middle 1.1251 0.607396 apical 1.2975 0.548605 b1 coronal 2.9464 0.521307 middle 3.5701 0.717203 apical 4.1697 0.629287 b2 coronal 2.9971 0.836391 middle 3.4908 0.707482 apical 4.184 0.773615 c1 coronal 3.4071 0.652522 middle 3.8086 0.75308 apical 4.2111 0.877046 c2 coronal 3.5704 0.63928 middle 4.488 0.526285 apical 4.8891 0.598721 j bagh college dentistry vol. 25(4), december 2013 the effect of smear restorative dentistry 11 table 2: anova test for push-out bond strength among three levels for each type of sealer groups areas areas difference (d.f.=29) f-test p-value sig. a1 coronal 77.44 0.000 h.s. middle apical a2 coronal 3.95 0.03 s. middle apical b1 coronal 9.49 0.001 h.s. middle apical b2 coronal 5.91 0.007 h.s. middle apical c1 coronal 2.75 0.08 n.s. middle apical c2 coronal 13.71 0.000 h.s. middle apical p ≥ 0.05: non significant (ns) p < 0.05: significant (s) p ≤ 0.01: highly significant (hs) table 3: student t test of push out bond strength between two levels of each group of sealer p ≥ 0.05: non significant (ns) p < 0.05: significant (s) p ≤ 0.01: highly significant (hs) groups levels t-test p-value sig. a coronal a1 6.89 0.000 h.s coronal a2 middle a1 0.61 0.55 n.s. middle a2 apical a1 2.02 0.06 n.s. apical a2 b coronal b1 -0.16 0.87 n.s. coronal b2 middle b1 0.29 0.78 n.s. middle b2 apical b1 -0.05 0.96 n.s. apical b2 c coronal c1 -0.58 0.57 n.s. coronal c2 middle c1 -2.34 0.03 s. middle c2 apical c1 -2.02 0.06 n.s. apical c2 30wisam f.doc j bagh college dentistry vol. 28(3), september 2016 significance of salivary pedodontics, orthodontics and preventive dentistry 178 significance of salivary mirna 21 determined by real time pcr in patients with squamous cell carcinoma wisam hamid edan, b.d.s., m.sc. (1) sulafa khalid el-samarrai, b.d.s., m.sc., ph.d. (2) abstract background: salivary biomarkers, a non-invasive alternative method to serum and tissue based biomarkers and it is consider as an effective modality for early diagnosis. salivary microrna 21, a nucleotide biomarker, was reported to increase in patients with oral squamous cell carcinoma. this study was conducted to measure the fold change of microrna 21 in stimulated saliva and to study its association with smoking and occurrence of oral squamous cell carcinoma. materials and methods: a 20 patients with oral squamous cell carcinoma who used to be smokers was included in addition to 40 control subjects (20 smokers and 20 nonsmokers health looking subjects). stimulated saliva was collected under standardized condition. salivary microrna 21 was assessed by real time pcr. results: microrna 21 fold change was significantly higher in both smoker patients with oral squamous cell carcinoma and in smoker control subjects compared to non-smoker control subjects. conclusions: salivary micrrna21 can serve as a non-invasive tool aid in the diagnosis and follow up of squamous cell carcinoma patients. keywords: oral squamous cell carcinoma, saliva, microrna 21. (j bagh coll dentistry 2016; 28(3):178-180). introduction biomolecules that are circulating in the blood are also found in human saliva. it consists of approximately about 2,000 proteins, 26% of these proteins are also found in blood, therefore emphasizes the saliva's importance as an added biological resource for disease diagnosis and monitoring, as well as an ultimate diagnostic medium to establish a person's response to treatment (1). the dna, rna and protein molecules derived from the living cancer cells can be conveniently obtained from saliva. thus, salivary biomarkers, a non-invasive alternative to serum and tissue based biomarkers may be an effective modality for early diagnosis, prognostication and monitoring post therapy status. the mirna-21 can also serve as a circulating tumor biomarker for the early diagnosis (2). a key factor in the lack of improvement in prognosis of oral squamous cell carcinoma lesions over the years is the fact that a significant proportion are not diagnosed or treated until they reach an advanced stage. in iraq oral cancer account for about 4.5 % of all cancer cases according to iraqi cancer registry and squamous cell carcinoma represents about 91.5 % of all oral cancer and 37 % of head and neck cancer (3). (1)ph.d. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. among the list of well defined risk factors for oral squamous cell carcinoma, cigarette smoking stands at the top of the list and still blamed as a major risk factor. it is believed that oral squamous cell carcinoma is acquired following multistep genetic mutations which will ultimately give the epithelial cells the phenotypic properties of self sufficiency in growth, evasion of apoptosis, invasion and stimulation of angiogenesis, and tobacco is claimed to be one of the major environmental carcinogenic agents that are responsible for such mutations (4). mirna21 is thought to be an important target in the pathogenesis of oral squamous carcinoma. over expression of mirna21 is reported in many malignant tumors including oral squamous cell carcinoma mirna21 can be detected in human saliva and used as a biomarker for early detection of malignant and dysplastic premalignant lesions in the oral cavity saliva as such can serve as a noninvasive investigatory tool for early diagnosis, monitoring treatment and prognostication of oral squamous cell carcinoma. the aim of this study was to measure the fold change of microrna 21 in stimulated saliva among patients with oral squamous cell carcinoma, and to study its association with smoking. subjects, materials and methods the present study included 20 patients with oral squamous cell carcinoma who used to be smokers. for the purpose of comparison, 20 j bagh college dentistry vol. 28(3), september 2016 significance of salivary pedodontics, orthodontics and preventive dentistry 179 apparently healthy smokers and another 20 nonsmokers were enrolled. control subjects were chosen in such a way to be matched with age and gender of the patients. patients age was from 40 to 70 years, included (8) females and (12) males. the study was conducted in ghazi al-hariri hospital, al-yarmook teaching hospital and al-kadhimiya teaching hospital in baghdad. the study was held from october 2014 through february 2015. from each patient and control subjects a sample of stimulated saliva (400μl) was obtained between 8:00 am and 11:00 am. treated with rnase inhibitor, and stored at -20c° till the time of molecular analysis. micro rna21 was quantified using steam loop real time pcr (total rna extraction kit accuzol; bioneer, korea). statistical analysis was performed using spss version 16. being a non-normally distributed variable, comparison of medians of microrna 21 fold change among groups was done using the non-parametric kruskal wallis test. p-value was considered significant when it was less than or equal to 0.05 and highly significant when it was less than or equal to 0.01. results salivary microrna21 expression fold change was higher in patients with squamous cell carcinoma than smoker control subjects. also it was higher in smoker patients than in non-smoker control subjects. on the other hand, smoker control subjects showed a higher microrna21 fold change than non-smoker control subjects figure 1 and table 1. the difference was highly significant (p<0.001) as shown in table 2. fig. 1: median microrna 21 fold change in the study groups table 1: descriptive statistics of mirna21 fold change among the three study groups n mean s.d. min. max. smoker carcinoma 20 9.971 3.488 4.230 17.480 smoker no carcinoma 20 3.813 1.409 2.000 7.940 non-smoker no carcinoma 20 0.851 0.389 0.380 1.700 kruskal wallis h test = 50.930, d.f. = 2, p-value = <0.001 table 2: statistical differences among the study groups groups mannwhitney u test d.f. p-value group 1 vs. group 2 12 1 <0.001 group 1 vs. group 3 0 1 <0.001 group 2 vs. group 3 0 1 <0.001 discussion the present study showed a highly significant over-expression of microrna 21 fold changes in smoker subjects and further over-expression in smoker patients with oscc in comparison with non smoker subjects. in accordance with results of the present study, soga et al. (7) stated that microrna21 was up regulated more than four folds in oral cancer compared to normal subjects. sio et al. (8) also stated that microrna 21 was over-expressed (11.4 fold change) in comparison to normal subjects, in accordance with the result of the present study (8). the explanation for the role of microrna 21 in oscc may be due to the fact that mirna-21 causes over-expression of ras oncogene and subsequently increased cell proliferation, as shown in the study done by ren et al. (9). on the other hand, microrna 21 may cause suppression of programmed cell death 4 (pdcd4) mrna, and hence it's corresponding protein. pdcd4 is a known tumor suppressor protein, the role of which is to prevent uncontrolled cell proliferation, and its suppression may play an important role in the pathogenesis of oscc, as stated by miranda (10) and yong et al. (11). an interesting finding of the present study is the highly significant over-expression of microrna 21 fold changes in healthy smoker subjects in comparison with healthy non-smoker subjects, opening the scope for future studies about the relation between smoking and micrrna 21 and augmenting the insight to word j bagh college dentistry vol. 28(3), september 2016 significance of salivary pedodontics, orthodontics and preventive dentistry 180 smoking cessation as an important early measure to prevent oscc development. in conclusion, salivary micrrna21 can serve as a non-invasive tool to aid in the diagnosis and follow up of squamous cell carcinoma patients. references 1. arunkumar s, arunkumar js, burde kn, shakunthala gk. developments in diagnostic applications of saliva in oral and systemic diseasesa comprehensive review. journal of scientific and innovative res 2014; 3(3): 372-87 2. wei j, gao w, zhu cj, liu yq, mei z, cheng t, shu yq. identification of plasma microrna-21 as a biomarker for early detection and chemo sensitivity of non-small cell lung cancer. chin j cancer 2011; 30(6): 407-14. 3. al-rawi nh, talaban g. squamous cell carcinoma of the oral cavity: a cases series analysis of clinical presentation and histological grading of 1425 cases from iraq. clinic oral invest 2007; 12(1):15-8. 4. hanahn d, weinberg ra. the hallmarks of cancer. cell 2000; 100(1): 57-70. 5. hui aby, lenarduzi m, krushel t, waldron l, pintilie m, shi w, perezordonez b, jurisica i., o'sullivan b. waldrom j. comprehensive microrna profiling for head and neck squamous cell carcinoma. clin cancer res 2009; 16; 1129-39. 6. courthod g, piefrancesco f, lordana p, salvatore p, gianmauro n. the role of microrna in head and neck cancer; current knowledge and perspectives. molecules 2014; 19: 5704-16 7. soga d, yoshiba s, shiogama s, miyazaki h, kondo s, shintani s. microrna expression profiles in oral squamous cell carcinoma. oncology report 2013; 30: 579-83 8. sio my, karen ng, chong vk, jamaludin m. dysregulation of mir-31 and mir-375 expression is associated with clinical outcomes in oral carcinoma. oral diseases 2014; 20: 345-51. 9. ren j, zhu d, liu m, sun y, tian l. downregulation of mir-21 modulates ras expression to promote apoptosis and suppress invasion of laryngeal squamous cell carcinoma. eur j cancer 2010; 46(18): 3409-16. 10. tomenson mj. programmed cell death 4 is a direct target of mir-21 and regulates invasion in oral squamous cell carcinoma. a master thesis, department of medical biophysics, university of toronto, 2000 11. yong h, you by, xiao hz. microrna-21 gene and cancer. med oncol 2013; 30: 376 j bagh college dentistry vol. 26(1), march 2014 effect of nd-yag orthodontics, pedodontics and preventive dentistry 154 effect of nd-yag laser-irradiation on fluoride uptake by tooth enamel surface (in vitro) khamaal i. al-hasnawi, b.d.s (1) wesal a. al-obaidi, b.d.s, m.sc. (2) abstract background: the irradiation of teeth with a laser results in an interaction between the light and the biological constituents of the dental hard substance, which is converted directly into heat.this thermal effect is the cause of the structural and chemical enamel changes.the combined treatment of topical fluoride agent with laser may increase fluoride uptake, and reduce progression of caries-like lesions. the aim of this study was to measure the uptake of the acidulated phosphate fluoride and sodium fluoride to the buccal and lingual caries-like lesion enamel surfaces before and after irradiated by nd-yag laser in comparison with matching control group. materials and methods: the sample consisted of 30 human healthy upper premolar teeth which were stored in 0.1% thymol solution after extracted. every tooth divided into: buccal and lingual specimen, each specimen has a rectangular window which was divided to right and left halves (120 specimens). the sample was divided into 2groups (60 specimens) for buccal surface, and the same for lingual surface. the caries-like lesion was formed for all groups except control (1) each group treated with either acidulated phosphate fluoride 1.23% or sodium fluoride 2%, (30 specimens) which contain other subgroups, these are: (10 specimens) one half treated with fluoride agent only and another half as control (first group as control (1) without caries-like lesion, and the second group control (2) with caries-like lesion, then de-ionized water only). (10 specimens) treated with fluoride agent then irradiated by nd-yag laser; one half with program (1) (short pulse), andanother with program (2) (long pulse). (10 specimens) irradiated by nd-yag laser; one half with program (1) and another with program (2) then treated with fluoride agent. the specimens of enamel were sectioned and the fluoride uptake was determined with using fluoride sensitive electrode. results: there was a significant difference between the buccal and lingual enamel surfaces regarding the fluoride uptake in sound tooth, while a nonsignificant difference was observed after artificial caries-like lesion formation. conclusion: irradiation of nd-yag laser program (1) to the buccal and lingual caries-like lesion surfaces of enamel before application of fluoride agents (apf, naf) was significantly increase fluoride uptake than that of using laser after the application of fluoride agent, as well as from using laser of program (2) after and before the application of fluoride agent, and from using fluoride agent alone in the buccal and lingual surfaces. key words: nd-yag laser, acidulated phosphate fluoride, sodium fluoride. (j bagh coll dentistry 2014; 26(1):154-158). introduction the decline in dental caries over the last few decades has been attributed to the extensive use of fluoride. although fluoride is the most powerful treatment to prevent tooth decay, the development of new methods to completely control this disease is still necessary. in this way, lasers, combined or not with fluoride, have been tested on teeth to improve dental enamel properties in order to enhance its resistance to demineralization (1). fluoride penetration in the enamel occurs through the replacement of the relatively weak hydroxyl ions in the enamel mineral structure by the much more active fluoride ions, thereby improving the chemical stability of the enamel structure and making it more resistant to acids(2) . the use of laser favors the incorporation of fluoride into enamel, not only on its surface as calcium fluoride (caf2) but also within its crystalline structure(3).that the increment of caf2like material formation and retention is a result of the morphological changes promoted by laser irradiation, considering the melting promoted by (1)m.sc. student, department of pedodontics and preventive dentistry, dental college, university of baghdad. (2)professor, department of pedodontics and preventive dentistry, dental college, university of baghdad. nd:yag (4). as with all chemical reactions, the degree and speed of penetration of fluoride into the enamel and the formation of fluorapatite are strongly dependent upon concentration and temperature (5). low concentrations of fluoride prevented demineralization of sound enamel, and higher concentrations enhanced remineralization of artificial caries-like lesions (6). traditional therapy of early childhood caries can be improved with the use of nd:yag laser, fluoride gel was applied on the carious surfaces of teeth before irradiation with nd:yag laser. nd:yag laser tip was used in contact and caries was removed upon irradiation without using local analgesics (7). materials and methods the thirty blocks were divided into 2 groups the buccal surface (a) and the lingual surface (b), the tooth was sliced by a high speed turbine hand piece with flow of de-ionized water to form rectangular slabs (the enamel window technique) (8) on buccal and lingual surfaces of (6mm) in the midpoint of image line running from the highest cusp to the cej.the initial cut was made mesiodistally through the tip of the buccal cusp to get buccal and lingual surfaces dissection while j bagh college dentistry vol. 26(1), march 2014 effect of nd-yag orthodontics, pedodontics and preventive dentistry 155 holding the root and coronal dentine was removed. enamel sample was then served at approximately one-third of the buccal and lingual surfaces. these specimens of enamel were covered with red hard wax, so that the buccal and lingual enamel surfaces of rectangular slabs (6mm) were exposed to the environment and inner side fixed in wax block. after that therectangular slabs of each surface were separated with a midline by the turbine to right and left halves of 3mm and one of this half was covered with varnish nail, so they were subdivided randomly into 12 groups. each block was soaked for 7 days in continuous stirred artificial saliva 5 ml to develop a pellicle layer in incubator at 37oc. sub surface caries likelesion, was induced in each specimen by immersion for 24 hr at 37oc in a 14 ml solution of demineralization solution adjusted at ph of (5), after the demineralization solution the specimen rinsed with de-ionized water and analyzed. these groups of sixty specimens were: 5 specimens as a control (without caries like-lesion formation).5specimens as a control (treated with deionized water only, after caries like-lesion formation).5 specimens treated with acidulated phosphate fluoride (apf) 1.23%. 5 specimens treated with sodium fluoride (naf) 2%. 5 specimens treated with (apf) then irradiated with nd-yag laser of program (1). 5 specimens treated with(naf) then irradiated with nd-yag laser of program (1). 5 specimens treated with (apf) then irradiated with nd-yag laserof program(2). 5 specimens treated with (naf) then irradiated with nd-yag laser of program (2). 5 specimens irradiated with nd-yag laser of program (1) then treated with (apf). 5 specimens irradiated with nd-yag laser of program (1) then treated with (naf). 5 specimens irradiated with nd-yag laser of program (2) then treated with (apf). 5 specimens irradiated with nd-yag laser of program (2) then treated with (naf). after each enamel specimen treated as mention above, it was separated from enamel block by turbine hand piece (the acid resistant varnish was removed with acetonesoaked cotton applicator from the other specimen of 3mm to return soaked in artificial saliva then demineralization solution to complete the samples number) then dried and powdered using ceramic mortar and pestle.this powder was weighted in electronic balance then immersed in 0.4 ml hcl 1 mol/l was added to the tubes. the tubes were agitated for 30 minutes, then 0.8 ml naoh 0.5 mol/l was added (9). an equal volume of tisab ii (1.0 m acetate buffer ph 5.0, 1 mnacl and 0.4% edta) modified with 20 gnaoh/l was added to each solution containing the dissolved enamel layer. sample was dilution to 10 ml that required to immerging fluoride electrode sufficiently by de-ionized water that was used as the blank were mixed with a magnetic stirrer for 3 minutes.fluoride measurements were performed using an ion-selective electrode (wtw) gmbh (germany) fluoride electrode f 500 and fluoride combination electrode f 800, to determine the fluoride ions concentrations in enamel samples by the potential in mv of standard solutions were directly measured by the electrode and calibrated using the concentration scale or by plotting calibration graph or constructed on a standard semi logarithmic paper by plotting the mill volt readings (linear axis) against concentration (long axis). results fluoride uptake of enamel before and after artificial caries-like lesion formation between buccal and lingual surfaces represented by the percentages of fluoride per 100mg of tooth enamelwas shown in (table1).it was found that, the a highly significant mean value was reported in buccal surface than that of lingual surface regarding the group control (1) without caries-like lesion. non significant difference was recorded between two surfaces concerning the group control (2) with caries-like lesion and de-ionized water (p>0.05). a highly significant mean values between control (1) and control (2) in buccal and lingual surfaces.by using the lsd test, the comparison (con 2) and other groups in buccal surface was illustrated in (table 2), not significant differences were observed between group (con 2) and groups (naf, apf+l1 and l2+naf), while significant differences were recorded with others in the buccal surface. highly significant differences were observed in (table 3) between group (con2) and most of the groups except (apf, naf, apf+l1 and l2+naf), which were not significant differences (p>0.05) in the lingual surface. lsd and p-values were used to compare among all study groups. the data was presented in (table 4) for buccal surface and in (table 5) for lingual surface. regarding the buccal surface, the results had shown that different mean values of fluoride uptake in group (l1+apf) and (l1+naf) were not significant. while highly significant differences were recorded with the other groups. discussion it is widely known that nd:yag laser associated with topical application of fluoride can increase enamel resistance to demineralization; however, this study was conducted to assessed the j bagh college dentistry vol. 26(1), march 2014 effect of nd-yag orthodontics, pedodontics and preventive dentistry 156 effect of nd-yag laser-irradiation on fluoride uptake by tooth enamel surface (in vitro).in pilot study sound enamel was used without caries like lesion, but the results revealed the same for all groups. finding of study on smooth surface reported that the administration of 1.23% apf gel one or two times and associated with the daily use of a fluoridated dentifrice was not capable for enhancing surface hardness and fluoride content in bovine enamel, in comparison to blocks submitted to demineralisation alone (10). as well as, the fluoride acquired after single application with apf was mainly loosely bound and was lost rapidly. while that acquired after three application was mainly permanently retained as fluorapatite(11).the result of present study observed that significant differences between the group control (1) and group control (2) in fluoride uptake, in which enamel demineralization leads to the dissolution of hydroxyapatite and the diffusion of ca and p ions on the enamel surface. the hyper saturation of these ions causes reprecipitation of hydroxyapatite, forming an intact superficial layer on the enamel surface. thus, enamel remineralization is achieved through the presence of fluoride in the medium (12). a likely hypothesis for the results of the present study is the deposition of fluoride ions in the outermost layers of the enamel, impeding the action of fluoride in the mineral deposition in the inner portion of the lesion. the outer layers of human enamel are especially sensitive to fluoride and might be stabilized and condensed due to incorporation of this element (13).various lasers can reduce the rate of surface demineralization in enamel, when it is submitted to acids (ph 5.5) that cause caries .several studies emphasized the use of different lasers in association with various forms of fluoride for the reduction of demineralization. the laser is applied to fluoride to increase fluoride diffusibility, which promotes greater ion absorption in the enamel or favors ion linking in the adjacent area (14,15).nd:yag laser irradiation provided a reduction in caries incidence compared with the non-treatment control. these findings are in agreement with those reported for the effect of combined fluoride and nd:yag laser irradiation treatment on in vitro enamel caries (16).the present study revealed that the irradiation of nd-yag laser to the enamel surface before the application of apf or naf agents was significant higher then after them or were used with unlased enamel. these findings are in agreement with those reported for the effect of combination fluoride and nd:yag laser irradiation\ treatment on in vitro enamel caries (reduction of 40% for premolars caries) (16). a significant synergism has been shown between laser and fluoride in the reduction of enamel solubility. indeed, topical apf application promotes the dissolution of more soluble apatite crystals, and a large quantity of caf2 is formed on the surface (17). laser irradiation can retain fluoride ions longer than unlased enamel, and the mechanisms of this fluoride retention are still unknown (18). it was proposed that laser irradiation can promote the formation of microspaces in enamel, which would facilitate the fluoride incorporation; moreover, laser irradiation can induce the formation of fluorapatite by incorporation of fluoride into the melted layers of the enamel surface, another suggested mechanism is that laser irradiation can increase fluoride diffusion through enamel and generate fluoride reservoirs(19).in the present study, the combination of topical fluoride treatment following laser irradiation provided an even greater degree of caries resistance. since heat was found to enhance the uptake of fluoride, it was speculated that the thermal effect of the laser was the main factor in promoting fluoride uptake and an increase in enamel resistance to demineralization (20) . the use of program (1) then fluoride application was recorded highly a significant fluoride uptake than program (2), that the higher fluoride incorporation was noted in samples irradiated with the lowest fluencies. these results indicate that the low fluencies generated some structural changes in the enamel surface that propitiated the retention of fluoride. similar findings were reported when argon laser was irradiated at low fluency on enamel when it was suggested that laser irradiation could increase the fluoride diffusion through the enamel structure or generated reservoirs for fluoride deposition into enamel (19). the findings of this study suggest that nd:yag, within the parameters tested, followed by topical apf application in both methodologies used, can prevent or retard the demineralization caused by citric acid erosion and lead to preservation of the enamel (21). j bagh college dentistry vol. 26(1), march 2014 effect of nd-yag orthodontics, pedodontics and preventive dentistry 157 table 1: concentration of fluoride uptake in enamel before and after artificial caries-like lesion formation between buccal and lingual surfaces. group buccal lingual p-value ∆mean +sd ∆mean +sd control 1 0.0047 0.0001 0.0042 0.0001 0.001* control 2 0.0194 0.0029 0.0197 0.0018 0.831 p-value 0.001* 0.001* *highly significant; df=8, ∆percentage of fluoride /100mg enamel. table 2: lsd test between control (2) and other groups in buccal surface. mean difference p-value significance apf -0.0075 0.036 s naf -0.0066 0.063 ns apf+l1 -0.0070 0.050 ns naf+l1 -0.0102 0.005 hs apf+l2 -0.0102 0.005 hs naf+l2 -0.0105 0.004 hs l1+apf -0.0217 0.001 hs l1+naf -0.0251 0.001 hs l2+apf -0.0119 0.001 hs l2+naf -0.0059 0.098 ns table 3: lsd test between control (2) and other groups in lingual surface. mean difference p-value significance apf -0.0045 0.110 ns naf -0.0033 0.238 ns apf+l1 -0.0049 0.081 ns naf+l1 -0.0080 0.006 hs apf+l2 -0.0089 0.002 hs naf+l2 -0.0082 0.005 hs l1+apf -0.0181 0.001 hs l1+naf -0.0207 0.001 hs l2+apf -0.0077 0.008 hs l2+naf -0.0034 0.227 ns table 4: lsd multiple comparison test in buccal surface. apf naf apf+l1 naf+l1 apf+l2 naf+l2 l1+apf l1+naf l2+apf naf 0.798 apf+l1 0.882 0.914 naf+l1 0.443 0.308 0.361 apf+l2 0.443 0.308 0.361 1.000 naf+l2 0.401 0.275 0.324 0.941 0.941 l1+apf 0.001* 0.001* 0.001* 0.002* 0.002* 0.002* l1+naf 0.001* 0.001* 0.001* 0.001* 0.001* 0.001* 0.327 l2+apf 0.210 0.133 0.162 0.621 0.621 0.674 0.008* 0.001* l2+naf 0.641 0.833 0.750 0.220 0.220 0.194 0.001* 0.001* 0.088 * significant j bagh college dentistry vol. 26(1), march 2014 effect of nd-yag orthodontics, pedodontics and preventive dentistry 158 table 5: lsd multiple comparison test in lingual surface. apf naf apf+l1 naf+l1 apf+l2 naf+l2 l1+apf l1+naf l2+apf naf 0.665 apf+l1 0.881 0.560 naf+l1 0.214 0.097 0.273 apf+l2 0.121 0.049* 0.159 0.749 naf+l2 0.197 0.087 0.253 0.960 0.787 l1+apf 0.001* 0.001* 0.001* 0.001* 0.002* 0.001* l1+naf 0.001* 0.001* 0.001* 0.001* 0.001* 0.001* 0.368 l2+apf 0.267 0.126 0.336 0.893 0.649 0.853 0.001* 0.001* l2+naf 0.685 0.977 0.580 0.102 0.053 0.093 0.001* 0.001* 0.133 * significant references 1. zezell dm, boari hgd, ana pa, eduardo cp, powel gl. nd:yag laser in caries prevention: a clinical trial. lasers surg med 2009; 41:31-35. 2. bayrak s, tunc es, aksoy a, ertas e, guvenc d, ozer s. fluoride release and recharge from different materials used as fissure sealants. eur j dent 2010; 4: 245–50. 3. magalhaes ac, rios d, machado ma. effect of nd:yag irradiation and fluoride application on dentine resistance to erosion in vitro. photomed laser surg 2008; 26: 559-63. 4. boari hgd, ana pa, eduardo cp, powell gl, zezell dm. absorption and thermal study of dental enamel when irradiated with nd:yag laser with the aim of caries prevention. laser phys 2009; 19(7): 1463-9. 5. skoog da, west dm, holler jf. fundamentals of analytical chemistry. 8th ed. saunders collage publishing; usa: 1997. pp. 621–26. 6. yamazaki h, litman a, margolis hc. effect of fluoride on artificial caries lesion progression and repair in human enamel: regulation of mineral deposition and dissolution under in vivo-like conditions. arch oral biol 2007; 52:110–20. 7. birardi v, bossi l, dinoi c. use of the nd:yag laser in the treatment of early childhood caries. eur j paediatr dent 2004; 5:98–101. 8. grenby th, bull j m. chemical studies of the protective action of phosphate compounds against the demineralization of human dental enamel in vitro. caries res. 1980; 14:210-220. 9. lves kmrp, pessan jp, brighenti fl. in vitro evaluation of the effectiveness of acidic fluoride dentifrices. caries res 2007; 41: 263-7. 10. jardim jj, pagot ma, maltz m. artificial enamel dental caries treated with different topical fluoride regimes: an in situ study. j dent 2008; 36:396-401. 11. salih lam. fluoride uptake, distribution, retention and its effect on remineralization in human enamel. an in vitro study. m.sc. thesis, college of dentistry, university of baghdad, 1993. 12. arnold wh, dorow a, langenhorst s, gintner z, banoczy j, gaengler p. effect of fluoride toothpastes on enamel demineralization. bmc oral health 2006; 6: 8. 13. karlinsey rl, mackey ac, walker tj. in vitro remineralization of human and bovine white-spot enamel lesions by naf dentifrices:a pilot study. j dent oral hyg 2011; 3: 22-9. 14. bevilacqua fm, zezell dm, magnani r, ana pa, eduardo cp. fluoride uptake and acid resistance of enamel irradiated with er:yag laser. lasers med. sci 2008; 23:141–7. 15. steiner-oliveira c, rodrigues lk, lima eb, et al. effect of the co2 laser combined with fluoridated products on the inhibition of enamel demineralization. j contemp dent pract 2008; 9:11321. 16. huang gf, lan wh, guo mk, chiang cp. synergistic effect of nd:yag laser combined with fluoride varnish on inhibition of caries formation in dental pits and fissures in vitro. j formos med assoc 2001; 100:181–5. 17. ana pa, tabchoury cpm, cury ja, zezell dm. effect of er,cr:ysgg laser and fluoride application on enamel demineralization. caries res 2007; 41:325–326. 18. delbem acb, cury ja, nakassima ck, gouveia vg, theodoro lh. effect of er:yag laser on caf2 formation and its anti-cariogenic action on human enamelan in vitro study. j clin laser med surg 2003; 21(4):197–202. 19. nammour s, demortier g, florio p, delhaye y, pireaux jj, morciaux y, powell l. increase of enamel fluoride retention by low fluence argon laser in vivo. lasers surg med 2003; 33:260–3. 20. hossain m, nakamura y, kimura y, yamada y, kawanaka t, matsumoto k. effect of pulsed. nd: yag laser irradiation on acid demineralization of enamel and dentin. journal of clinical laser medicine & surgery 2001; 19(2):105-8. 21. maria aps, karina m l, wagner de r, sheila r m, karen m r. effect of nd:yag laser and acidulated phosphate fluoride on bovine and human enamel submitted to erosion/abrasion or erosion only: an in vitro preliminary study. photomedicine and laser surgery 2009: 709-13. amaal f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 computed tomographic oral diagnosis 30 computed tomographic localization of infraorbital foramen position and correlation with the age and gender of iraqi subjects amaal i. mohammed, b.d.s. (1) ahlam a. fatah, b.d.s., m.sc. (2) abstract background: the infraorbital foramen is an anatomical structure with an important location in the maxilla, position of foramen in maxillofacial area is necessary in clinical situation requiring regional nerve blocks that are performed in children undergoing facial surgeries to avoid injury to corresponding nerve. the aim of study was to determine the position of the infraorbital foramen and to correlate infraorbital foramen position with age and gender using computed tomography. subjects, materials, and methods: the sample consist of prospective study for 50 iraqi subjects (21 male and 29 female) with age ranged from (5-17) years. the examination was performed on multi – slice spiral tomography scanner in al-karakh general hospital. using sagittal and coronal sections including right and left sides and the following measurements were done: 1. the distance from crista galli to the midpoint of fusion of hard palate(midline of the patient) in the coronal section. 2. the distance from mid line to the infraorbital foramen, in the coronal section for both sides right and left. 3. the distance from sella turcica to the infraorbital foramen, in sagittal section for both sides right and left. 4. the distance from nasion to the infraorbital foramen, in coronal section for both sides right and left. results: the partial regression coefficient for each year increase in age the linear measurements (midline-infraorbital foramen) (nasion-infraorbital foramen) and (vertical distance from nasion meeting the horizontal line from infraorbital foramen to midline) are expected to significantly increase after adjusting for confounding effect of gender. from multiple linear regression model designed in this study two mathematical formulae were derived for correlation of infraorbital foramen position with the age and gender: y1 [linear measurement (midline-infraorbital foramen) mm] = 19.56 + (1.02 x gender) + (0.53x age in years). y2 [linear measurement (vertical distance from nasion meeting the horizontal line from infraorbital foramen to midline)] = 28.42 + (2.5 x gender) + (0.30 x age in years). conclusions: computed tomography scan information facilitates the localization of infraorbital foramen position for successful access of the needle in infraorbital nerve block in children of different age and gender. key words: infraorbital foramen position, computed tomographic, infraorbital nerve block. (j bagh coll dentistry 2013; 25(special issue 1):30-35). introduction infraorbital foramen (iof) is located in the maxillae which are the largest bones of the face, above the canine fossa, the end of the infraorbital canal (ioc); it transmits the infraorbital vessels and nerve (1-3). anatomically the maxillary nerve has several branches that can be blocked by the use of local anesthetic solution. in infraorbital canal, the nerve gives rise to 2 branches: the anterior superior alveolar nerve and the middle superior alveolar nerve. these sensory nerves supply the mucous membrane of the anterior portion of inferior meatus and the floor of the nasal cavity. as the nerve exits the infraorbital foramen, it gives rise to 3 branches: (4-6) 1. inferior palpebral, which supplies the skin and conductive of the lower eyelid. 2. external nasal, which supplies the side of nose and the nasal septum and joins the terminal twigs of the naso ciliary nerve. (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. 3. superior labial which supplies the sensory innervations of the upper lip, the mucous membrane of the mouth and the labial glands they are joined immediately below the orbit by filaments of the facial nerve & form the infra orbital plexus. a sensory block of the infraorbital nerve (ion) can be performed and the access by use of an intra oral route or an extra oral route (atranscutaneous). for these approaches, recognition of the location of the iof is crucial, once the location of the infra orbital foramen is determined, a needle is advanced either through the skin directly toward the iof or through mouth at the level of the incisor at alveolar-buccal mucosal margin in the subsulcal plane. in our study ct localization of iof position in children of varying age groups to facilitate successful placement of ion block required for different maxillofacial surgeries (8, 9). materials and methodes the study sample consist of 50 iraqi subjects (21 male and 29 female ) with age ranged from j bagh college dentistry vol. 25(special issue 1), june 2013 computed tomographic oral diagnosis 31 (5-17) years , attending the maxillofacial department at al-gerahat specialist and al-karakh general hospitals in baghdad from september 2011 to march 2012, for various maxillofacial surgeries. the examination was performed on multi – slice spiral tomography scanner (the philips brilliance ct-64) in (al-karkh general hospital) to identify the exact position of iof for both sides (right and left) using coronal and sagittal sections as shown in figure (2-4 and 2-5) and the following measurements were done: 1. c-m the distance from crista galli to the midpoint of fusion of hard palate (mid line of the patient), in the coronal section. 2. midline-iof the distance from mid line to the iof, in the coronal section for both sides right and left . 3. n-iof the distance from nasion to the iof, in coronal section for both sides right and left . 4. s-iof the distance from sella turcica to the iof, in sagittal section for both sides right and left. figure 1: measurement of c-m in coronal section. figure 2: measurement of midline-iof in coronal section. figure 3: measurement of n-iof (right and left) in coronal section. figure 4: sagittal section without manipulation of image figure 5: measurement of s-iof in sagital section with manipulation of image statistical data analysis the multiple linear regression model was used to assess the predictive power of age and gender on each specific measurement. the model provide the following parameters: 1. p model: for the model to be generalized to the population it must be statistically significant. 2. b (partial regression coefficient): the amount of change in outcome (response) variable for each unit increase in the independent (explanatory) variable after adjusting for other explanatory variables included in the model. j bagh college dentistry vol. 25(special issue 1), june 2013 computed tomographic oral diagnosis 32 1. p value for regression coefficient 2. determination coefficient (r2): 3. means the amount of explained variation in the dependent variable. asymmetry index (laterality dimorphism) measure magnitude of a difference between right and left side as a percentage of a reference side (either right or left ) in the current study since the right side measurement was larger than the left side, the formula used referred to the left side measurement as reference. therefore apposition value for the index means that the right side is larger while a negative index indicates that the right side is smaller than the left. (10) asymmetry index = results this study included 50 iraqi subjects age ranged from (5-17) years .the distribution of gender in the total sample was 21 males 42% and 29 females 58%. a multiple linear regression model was used to calculate the net and independent effect of age and gender on of each of the selected linear measurements magnitude. as shown in the table (1): 1for each year increase in age the linear measurement (c to m) the partial regression coefficient is expected to significantly increase by 1.120 mm after adjusting for confounding effect of gender. 2-male gender is associated with a higher mean by an average of 4.400 mm compared to females this effect reaches the level of statistical significant after adjusting for age. the model was statistically significant and able to explain 46.2%is observed variation in measurement. table 1: multiple linear regression model with (linear measurement crista galli to midpalate) as the dependent (response) variable in addition to gender and age as independent (explanatory) variables. linear measurement (c to m) mm partial regression coefficient p (constant) 44.320 <0.001 gender 4.400 0.003 age in years 1.120 <0.001 r2 = 0.462 p (model) < 0.001 as shown in the table (2): 1for each year increase in age the linear measurement (n-iof) the partial regression coefficient is expected to significantly increase by 0.59mm after adjusting for confounding effect of gender. 2-male gender is associated with a higher mean by an average of 7.87 mm compared to females this effect reaches the level of statistical significant after adjusting for age. the model was statistically significant and able to explain 28.1%is observed variation in measurement. table 2: multiple linear regression model with (linear measurement n to iof) as the dependent (response) variable in addition to gender and age as independent (explanatory) variables linear measurement (n-iof) mm partial regression coefficient p (constant) 34.39 <0.001 gender 7.87 <0.001 age in years 0.59 <0.001 r2 = 0.281 p (model) < 0.001 as shown in the table (3): 1-for each year increase in age the linear measurement (midline-iof) the partial regression coefficient is expected to significantly increase by 0.53 mm after adjusting for confounding effect of gender. 2-male gender is associated with a higher mean by an average of 1.02 mm compared to females this effect fail to reach the level of statistical significant after adjusting for age. the model was statistically significant and able to explain 13%is observed variation in measurement. table 3: multiple linear regression model with (linear measurement midline to iof) as the dependent (response) variable in addition to gender and age as independent (explanatory) variables linear measurement (midline-iof) mm partial regression coefficient p (constant) 19.56 <0.001 gender 1.02 0.31[ns] age in years 0.53 <0.001 r2 = 0.13 p (model) = 0.001 a mathematic formula can be derived from the above multiple linear regression model to localize the exact position of iof in relation to the age and gender for each patient: y1 [linear measurement (midline-iof) mm] = 19.56 + (1.02 × gender) + (0.53× age in years). j bagh college dentistry vol. 25(special issue 1), june 2013 computed tomographic oral diagnosis 33 as shown in the table (4): 1-for each year increases in age the linear measurement (vertical distance from n meeting the horizontal line from iof to midline) the partial regression coefficient is expected to significantly increase by 0.30 mm after adjusting for confounding effect of gender. 2-male gender is associated with a higher mean by an average of 2.50mm compared to females. this effect reaches the level of statistical significant after adjusting for age. the model was statistically significant and able to explain 8.5%is observed variation in measurement. table 4: multiple linear regression model with (linear measurement vertical distance from n to iof horizontal line) as the dependent (response) variable in addition to gender and age as independent (explanatory) variables linear measurement (vertical distance from n meeting the horizontal line from iof to midline ) partial regression coefficient p (constant) 28.42 <0.001 gender 2.50 0.021 age in years 0.30 0.048 r2 = 0.085 p (model) = 0.014 a mathematic formula can be derived from the above multiple linear regression model to localize the exact position of iof in relation to the age and gender for each patient: y2 [linear measurement (vertical distance from n meeting the horizontal line from iof to midline)] = 28.42 + (2.5 × gender) + (0.30 × age in years). as shown in the table (5): 1-for each year increase in age the linear measurement (s-iof) the partial regression coefficient is expected to significantly increase by0.66mm after adjusting for confounding effect of gender. 2-male gender is associated with a higher mean by an average of 1.23mm compared to females. this effect fails to reach the level of statistical significant after adjusting for age. the model was statistically significant and able to explain 24.2 %is observed variation in measurement. table 5: multiple linear regression model with (linear measurement s to iof) as the dependent (response) variable in addition to gender and age as independent (explanatory) variables linear measurement (s to iof) mm partial regression coefficient p (constant) 47.76 <0.001 gender 1.23 0.15[ns] age in years 0.66 <0.001 r2 = 0.242 p (model) < 0.001 as shown in the table (6): 1-for each year increase in age the angle measurement (n-iof-midline) the partial regression coefficient is expected to obviously increase by -0.28 mm degree after adjusting for confounding effect of gender. 2-male gender is associated with a higher mean by an average of 1.42mm degree compared to females. these effects fail to reach the level of statistical significant after adjusting for age and gender. the model no statistically significant and able to explain 2.5 % is observed variation in measurement. table 6: multiple linear regression model with (angle degree measurement) as the dependent (response) variable in addition to gender and age as independent (explanatory) variables. angle degree n-iofmidline) partial regression coefficient p (constant) 54.15 <0.001 gender 1.42 0.37[ns] age in years -0.28 0.22[ns] r2 = 0.025 p (model) = 0.3[ns] the mean of linear measurement (n-iof) was significantly higher in the right side by an average of 1.6 mm compared to left side. while the effect of laterality (r vs l)side show the right side increase in this linear measurement by an average of 3.8% of its reference left side as shown in the table (7). j bagh college dentistry vol. 25(special issue 1), june 2013 computed tomographic oral diagnosis 34 table 7: the differences in mean measurements of (n-iof) between right and left side. linear measurement (n-iof) mm left side right side difference between right and left side lateralitydimorphism % p (paired t-test) range (31.2 to 58) (35.6 to 59.1) (-1.8 to 7) 3.8 % <0.001 mean 42.6 44.2 1.6 sd 4.7 4.4 1.6 se 0.66 0.62 0.23 n 50 50 50 table 8: the differences in mean measurements of (midline-iof) between right and left side. linear measurement (midline-iof) mm left side right side difference between right and left side lateralitydimorphism % p (paired t-test) range (18.1 to 50.1) (20.5 to 51.9) (-7.5 to 7.2) 3.8 % <0.001 mean 26.5 27.5 1 sd 5.3 5.1 3.1 se 0.75 0.72 0.43 n 50 50 50 the mean of linear measurement (midlineiof) was significantly higher in the right side by an average of 1 mm compared to left side. while the effect of laterality (r vs l)side show the right side increase in this linear measurement by an average of 3.8% of its reference left side as shown in the table (8). the mean of linear measurement (vertical distance from n meeting the horizontal line from iof to midline) was significantly higher in the right side by an average of 1.2 mm compared to left side. while the effect of laterality (r vs l)side show the right side increase in this linear measurement by an average of 3.6% of its reference left side as shown in the table (9). this proportional right vs. left pattern is made more obvious by an almost stable (n-iofmidline) angle (-0.2%) included by the iof triangle formed by the previous 3 lines in both right and left as shown in table (10). the mean of linear measurement (s to iof) was significantly higher in the right side by an average of 1.6 mm compared to left side. while the effect of laterality (r vs l) side show the right side increase in this linear measurement by an average of 2.8% of its references left side as shown in the table (11). table 9: the differences in mean measurements of vertical distance from nasion meeting the horizontal line from iof to midline between right and left side. linear measurement (vertical distance from n meeting the horizontal line from iof to midline) left side right side difference between right and left side lateralitydimorphism % p (paired t-test) range (17.7 to 43.8) (18.7 to 46.3) (-5.3 to 8.7) 3.6 % 0.005 mean 32.9 34.1 1.2 sd 5.2 5.6 2.9 se 0.74 0.79 0.41 n 50 50 50 the three linear measurements (vertical distance from n meeting the horizontal line from iof to midline), (n-iof), and (midline-iof) associated with iof in the coronal plane showed comparable laterality dimorphism magnitude (ranging between 3.6 to 3.8% of left side reference value) (table 7-9). table 10: the differences in mean measurements of angle (n-iof-midline) between right and left side. angle degree (n-iofmidline) left side right side difference between right and left side lateralitydimorphism % p (paired t-test) range (30.3 to 62.8) (28.6 to 60.1) (-12.7 to 14.7) -0.2 % 0.87[ns] mean 51.1 50.9 -0.1 sd 7.7 7.9 5.2 se 1.09 1.12 0.74 n 50 50 50 table 11: the differences in mean measurements of (s-iof) between right and left side. linear measurement (s to iof) mm left side right side difference between right and left side lateraliydimorphism % p (paired t-test) range (46.7 to 65.5) (44.9 to 68) (-4.5 to 6.5) 2.8 % 0.027 mean 56.2 57.8 1.6 sd 4.6 4.7 2.5 se 0.65 0.67 0.36 n 50 50 50 discussion the accurate identification of iof position is important for both diagnostic and clinical procedures. clinicaly, nerves emerging from this j bagh college dentistry vol. 25(special issue 1), june 2013 computed tomographic oral diagnosis 35 foramen, could probably be injured during surgical procedures, resulting in parasthesia or anesthesia. an understanding of the anatomical location of this important maxillofacial foramen is of increased importance with the rising popularity of endoscopic procedures with limited visibility. (7) the current study provided an easy method for correlation of iof position with the age and gender. this method done by recording the age and gender of the pediatric patients, then using these values in mathematic formulae derived from multiple linear regression model for correlation of these two variables with iof position as shown in table (1, 2) suresh et al (7) study sample of 48 ct scans of children and derived a linear regression formula based on age only, distance of the infraorbital foramen (in mm) from midline =21.3+0.5 × age (in years). using this formula in currently study gave comparable results to those calculated using age and gender. the formula used in current study is however more accurate since it adjusted for the effect of gender. in the current study all the linear measurements (c-m, n-iof, midline-iof, vertical distance from n to horizontal line from iof to midline, s-iof evaluated showed a statistically significant positive linear association of iof linear measurements with age after adjusting the effect of gender with mean of partial regression coefficient respectively (1.120 and p value<0.001, 0.59and p value <0.001, 0.53 and p value <0.001, 0.30and p value <0.048, and0.66 and p value 0.001). suresh et al (7) reported positive linear correlation between age and linear measurement midline to iof. the relation between the linear measurements and the gender after adjusting age: in the current study the linear measurements (c-m, n-iof, vertical distance from n to horizontal line from iof to midline) evaluated showed a statistically significant positive linear association of iof linear measurements with gender after adjusting the effect of age with mean of partial regression coefficient respectively (4.400 and p value 0.003, 7.87and p value <0.001, 5.50and p value 0.021) as shown in tables (3-12, 3-13, 3-15). the linear measurements of s-iof and midline-iof failed to reach statistical significant due to small sample size lopes et al (4) reported the significant differences in the measurements of the distance from iof to the iom and from ans to iof between the male and female (p<0.005). references 1. slaby f, jacobs e. radiographic anatomy independent study. lippincott williams & wilkins; 1990. pp. 172173. 2. grays h. gray’s anatomy of the human body. 6th ed. new york: bartleby; 200. 3. richard l, drake a wayne vogl, adam w mitchell. gray’s anatomy for study. 2nd ed. churchill living stone 797. 4. lopes ptc, pereira gam, santos ampv, freitas cr, abreu brr, malafaia ac. morphometric analysis of the infraorbital foramen related to gender and laterality in dry skulls of adult individuals in southern. brazil braz j morphol sci 2010; 26(1): 19-22. 5. chandra rk, kennedy dw. surgical implication of an unusual anomaly of infra orbital nerve. ear, nose & throat j 2004. 6. simnatamby cs. last’s anatomy regional and applied. 11th ed. churchill living stone; 2006. pp.367. 7. suresh s, vorouov p, curran j. infra orbital nerve block in children: a computerized tomographic measurement of the location of the infraorbital foramen. regional anesthesia and pain medicine 2006; 31(3): 211-4. 8. wandee a pinhasmit. supin chompoopong, dolly methathrathip, roengsak sansuk, wanuapa phetphun phiphat. supraorbi notch/ foramen. infraorbital foramen and mental foramen in thais: an throponmetric measurements and surgical relevance. j med assoc thai 2006; 89(5):675-82. 9. terrier f, grossholz m, becker cd. spiral ct of the abdomen. springer: 2002. pp. 1-10. 10. white sc, pharoah mj. oral radiology principles and interpretations. 6th ed. mosby; 2009. pp. 597-610. 11. rossi m, ribeiro e, smith r. craniofacial asymmetry in development: an anatomical study. angle orthod 2003; 73(4): 381-5. maha.docx j bagh college dentistry vol. 28(1), march 2016 salivary α-amylase oral and maxillofacial surgery and periodontics 114 salivary α-amylase and albumin levels in patients with chronic periodontitis and poorly or well controlled type ii diabetes mellitus maha abdul aziz ahmed, b.d.s., m.sc. (1) abstract background: recent studies suggest that chronic periodontitis (cp) and type2 diabetes mellitus (t2dm) are bidirectionally associated. analysis of saliva as a mirror of oral and systemic health could allow identification of α amylase (α-am) and albumin (a1) antioxidant system markers to assist in the diagnosis and monitoring of both diseases. the present study aims at comparing the clinical periodontal parameters in chronic periodontitis patients with poorly or well controlled type 2diabetes mellitus, salivary α-am, a1, flow rate (fr) and ph then correlate between biochemical, physical and clinical periodontal parameters of each study and control groups. materials and methods: 80 males, with an age range of (35-50) years were divided into four groups, (20 subjects each): two groups had well or poorly controlled type 2diabetes mellitus both of them with chronic periodontitis, group of patients with only chronic periodontitis and control group with healthy periodontium and systemically healthy. from all subjects unstimulated whole salivary samples were collected to measure fr, ph, al and α – am, then clinical periodontal parameters (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level)were recorded. results: patients had chronic periodontitis with poorly controlled type 2diabetes mellitus demonstrated the highest median values of all clinical periodontal parameters and highest increase in levels of salivary α-am and al with lowest median values of fr and ph, in addition to the highly significant differences among the study and control groups regarding biochemical and physical parameters. positive correlations were revealed between α-am with al and both of them with all clinical periodontal parameters but, they were negative with fr and ph. conclusion: patients with poor glycemic control had more severe periodontal tissue break down with decrease in fr and ph also obvious increase in levels of a1 and αam so, these biochemical markers will provide an objective phenotype to allow practitioners for early diagnosis, which is essential for improved prognosis and effective delay of clinical complications associated with chronic periodontitis and dm and an important strategy to lower the incidence of both diseases world wide. keywords: periodontitis, type 2diabetes mellitus, salivary albumin and α-amylase. (j bagh coll dentistry 2016; 28(1):114-120). introduction periodontitis is irreversible inflammatory disorder of the supporting structures of the tooth leading to progressive attachment loss and destruction of alveolar bone. chronic periodontitis (cp) is the most prevalent form of periodontitis, hence affects about 10%-15% of adult population world wide. furthermore in the presence of systemic disease (e.g.dm),which modifies the host response to plaque accumulation, the disease progression may become more aggressive(1). the dm, is a metabolic disorder characterized by hyperglycemia and t2dm which is the most common type is linked to insulin resistance and patients with dm are prone to oral complications such as periodontal disease (pd), dry mouth and abscesses (2). hence, today various researches are being conducted to evaluate possible compound in the oral fluids through which it may possible to assess the presence and severity as well as, toidentify the patients at risk for these diseases thus, analysis of saliva which is a complex secretory fluid that can be easily collected through non-invasive means (1)assistant professor. department of periodontics. college of dentistry, university of baghdad. for the screening of large samples in addition, saliva contains locally produced microbial and host response mediators, as well as, systemic (serum) markers (3). thus the investigation of salivary proteins such as al and αam in patients with cp and dm may be useful to enhance the knowledge of their roles in these diseases. so, this study designed to determine the effect of glycemic control in t2dm on periodontal health status as well as, on the levels of salivary al, α-am, fr and ph. materials and methods the participants in this study was 80 males with age range (35-50) years, recruited from specialized center for endocrinology and diabetes in baghdad and from periodontics department, at the teaching hospital in the college of dentistry, university of baghdad. they were divided into four groups. 1. study group of 20 males suffer from cp with well controlled t2dm hba1c <7%(4) (cp+wt2dm). 2. study group of 20 males suffer from cp with poorly controlled t2dm,hba1c> 9%(4)(cp+pt2dm). j bagh college dentistry vol. 28(1), march 2016 salivary α-amylase oral and maxillofacial surgery and periodontics 115 3. study group of 20 males suffer from cp but systemically healthy (cp). 4. control group of 20 males with clinically healthy periodontium and apparently systemically healthy.healthy periodontium defined by the absence of any signs and symptoms of gingival inflammation, without periodontal pockets or clinical attachment loss. this group represented a base line data for the salivary al and α-am levels. patients with cp demonstrated the presence of at least four sites with ppd (≥4mm)and clinical attachment loss of (1-2) mm or greater (5). the inclusion criteria were only males with at least 20 teeth present, t2dm ≥ 5 years on oral hypoglycemic therapy only and body mass index within the normal range (18.5-24.9 kg/m2) (6). the exclusion criteria were females, presence of systemic diseases other than t2dm, patients administered medications (anti-inflammatory and anti-microbial) or undergone periodontal treatment in the 3 months prior to the study, smoking, alcohol consumption, t1dm and t2dmadministring insulin, presence of nephropathy, retinopathy and diabetic foot. unstimulated whole salivary samples were collected from all participants (7). during that salivary (fr) was measured through dividing the volume of the collected sample by the collection time. after this by using dp universal test paper, the salivary ph was measured, then samples were centrifuged for 15min. at 4000rpm and frozen, at -20 c. by using michigan o periodontal probe, the examination of clinical periodontal parameters was performed on four surfaces (mesial, buccal/labial, distal and lingual / palatal) of all teeth except the 3rd molar, which included: 1. plaque index system (pli)(8). 2. gingival index system (gi) (9). 3. bleeding on probing (bop) (1). 4. probing pocket depth (ppd). 5. clinical attachment level (cal). for biochemical analysis of salivary a1, protein u.s / syrbio kit was used. while for salivary αam, (single reagent galg2-cnp) /spectrum kit was used, hence the activities were determined by measuring the absorbace at 598 nm and 405 nm respectively both by the spectrophotometer. descriptive statistics that include mean and median values and inferential statistics which include kruskal – wallis h test, mannwhitney u test and pearson correlation (r) were used. the level of significance (s) was accepted at p ≤0.05, highly significance (hs) at p < 0.01 and nonsignificant (ns) at p > 0.05. we certify that this study involving human subjects is in accordance with the helsinky declaration of 1975 as revised in 2000 and that it has been approved by the relevant institutional ethical committee. results the highest mean of age was found in cp + pt2dm group (45.85), followed by cp + wt2dm(44.95), then cp group (41.7) while, the least mean of age was detected in control group (38). patients with cp + pt2dm demonstrated the highest median values of the clinical periodontal parameters, then patients suffer from cp + wt2dm, after that cp patients. inter study groups comparisons regarding all clinical periodontal parameters revealed, hs differences between cp + pt2dm with both cp + wt2dm and cp groups while, they were ns differences between cp + wt2dm with cp groups (table -1). table 2 showed the biochemical analysis of both al and α – am presented that have highest increase in median values were revealed in cp + pt2dm group after that patients with cp + wt2dm, then cp group as compared to the control group hence, hs differences were demonstrated among the four groups. on the other hand, the physical parameters analysis showed decrease in median values of both fr and ph in study groups when compared to control group and the lowest median values demonstrated in cp + pt2 dm group. again, hs differences among the study and control groups were found. the comparisons between all pairs of the study and control groups regarding α-am, a1, fr and ph demonstrated hs and s differences except the ns differences between cp+wt2dm with cp groups concerning α-am, a1 and ph(table -3). the results of correlations (tables 4&5) between α-am and a1 with clinical periodontal parameters were positive but they were negative with fr and ph at all groups, although α-am revealed moderate positive correlations with pli and gi at cp + pt2 dm and cp + wt2dm groups respectively. the correlations between α-am with al were positive at all groups (table -6). j bagh college dentistry vol. 28(1), march 2016 salivary α-amylase oral and maxillofacial surgery and periodontics 116 table 1: median values of the clinical periodontal parameters and the inter groups comparisons between all pairs of the study groups cp & cp+ wt2dm cp+ pt2dm & cp cp+ pt2dm & cp+ wt2dm median groups clinical periodontal parameters pvalue sig. mann whitney u test pvalue sig. mann whitney u test pvalue sig. mann whitney u test 0.51 ns 1.948 0.00 hs 5.411 0.00 hs 4.735 2.682 cp+ pt2dm pli 1.815 cp+ wt2dm 1.341 cp 0.232 control 0.499 ns 0.677 0.00 hs 5.42 0.00 hs 5.410 2.553 cp+ pt2dm gi 1.556 cp+ wt2dm 1.5 cp 0.108 control 0.217 ns 1.233 0.00 hs 3.993 0.00 hs 4.390 60.5 cp+ pt2dm bop score1 46 cp+ wt2dm 42 cp 0.409 ns 0.825 0.00 hs 4.255 0.00 hs 4.363 6.67 cp+ pt2dm ppd 6.13 cp+ wt2dm 5.945 cp 0.323 ns 0.989 0.00 hs 4.749 0.00 hs 4.372 4.4 cp+ pt2dm cal 3.08 cp+ wt2dm 2.435 cp *p<0.01 high significant table 2 median values of salivary α-amylase , albumin ,fr and ph and the significance of differences among the study and control groups. kruskal-wallis h test control cp cp+ wt2dm cp+ pt2dm parameters p-valuesig. chi square median median median median 0.00 hs 43.62 65.47 90.86 99.25 162.14 α-amylase u/l 0.00 hs 30.568 56.51 75.72 79.18 104.8 albumin mg/dl 0.00 hs 65.6 1.2 0.75 0.725 0.23 fr ml/min 0.00 hs 24.96 7 6 6 5 ph j bagh college dentistry vol. 28(1), march 2016 salivary α-amylase oral and maxillofacial surgery and periodontics 117 table 3: inter groups comparisons of the median values of salivary α-amylase, albumin, fr and ph between all pairs of the study and control groups cp& control cp+ wt2dm&control cp+ wt2dm&cp cp+ pt2dm&control cp+ pt2dm&cp cp+ pt2dm&cp+ wt2dm parameters pvalue mann whitney u test pvalue mann whitney u test pvalue mann whitney u test pvalue mann whitney u test pvalue mann whitney u test pvalue mann whitney u test 0.00 hs 4.003 0.00 hs 4.436 0.725 ns 0.352 0.00 hs 5.410 0.00 hs 3.517 0.001 s 3.354 α-amylase u/l 0.00 hs 4.275 0.044 s 2.332 0.322 ns 0.864 0.00 hs 4.816 0.03 s 2.976 0.021 s 2.998 albumin mg/dl 0.00 hs 4.809 0.00 hs 5.278 0.00 hs 4.870 0.00 hs 5.444 0.00 hs 5.437 0.00 hs 4.998 fr ml/min 0.014 s 2.453 0.01 s 3.213 0.203 ns 1.274 0.00 hs 5.231 00.00 hs 4.925 0.00 hs 4.275 ph table 4: correlations between the levels of α-amylase with the clinical parameters of each study and control groups. control cp cp+ wt2dm cp+ pt2dm statistical analysis parameters 0.248 0.254 0.188 0.56 r pli 0.292 ns 0.281 ns 0.427 ns 0.816 ns p 0.290 0.222 0.57 0.164 r gi 0.214 ns 0.348 ns 0.012 s 0.489 ns p 0.003 0.227 0.207 r bop score1 0.990 ns 0.330 ns 0.381 ns p 0.199 0.039 0.173 r ppd 0.400 ns 0.871 ns 0.466 ns p 0.068 0.201 0.154 r cal 0.775 ns 0.395 ns 0.516 ns p -0.156 -0.009 -0.442 -0.268 r fr 0.511 ns 0.969 ns 0.049 s 0.254 ns p -0.096 -0.144 -0.035 -0.131 r ph 0.687 ns 0.543 ns 0.884 ns 0.582 ns p table 5: correlations between the levels of albumin with the clinical parameters of each study and control groups. control cp cp+ wt2dm cp+ pt2dm statistical analysis parameters 0.131 0.085 0.134 0.148 r pli 0.581 ns 0.721 ns 0.573 ns 0.533 ns p 0.224 0.070 0.186 0.327 r gi 0.343 ns 0.771 ns 0.434 ns 0.159 ns p 0.186 0.157 0.378 r bop score1 0.434 ns 0.508 ns 0.100 ns p 0.255 0.268 0.121 r ppd 0.277 ns 0.253 ns 0.611 ns p 0.107 0.189 0.482 r cal 0.653 ns 0.424 ns 0.032 s p -0.046 -0.151 -0.214 -0.321 r fr 0.847 ns 0.526 ns 0.365 ns 0.167 ns p -0.235 -0.045 -0.273 -0.197 r ph 0.318 ns 0.849 ns 0.245 ns 0.406 ns p j bagh college dentistry vol. 28(1), march 2016 salivary α-amylase oral and maxillofacial surgery and periodontics 118 table 6: correlations between salivary levels of (α-amylase and albumin) of each study and control groups. control cp cp+ wt2dm cp+ pt2dm statistical analysis parameters 0.511 0.195 0.103 0.291 r α-amylase and albumin 0.831 ns 0.411 ns 0.665 ns 0.214 ns p discussion the cp + t2dm patients revealed higher mean of age, this can be explained by the greater incidence of both diseasesin adults(10). in diabetic patients, the vascular changes, neutrophil dysfunction, altered collagen synthesis, accumulation of advanced glycation end products leading to impaired tissue repair capacity (1), as well as increased glucose level in gingival crevicular fluid (gcf) and saliva (11), decrease fr that disrupt the cleaning and buffering capacities and clearance of bacterial substrate which then increase accumulation of plaque and calculus (12), in addition increased levels of α – am andal, in which the former favored proliferation of both aerobic and anerobic bacteria in plaque, while the latter considered potential energy sources and enable the attachment of pathogenic bacteria thus alter the composition of plaque (13). so, diabetics had three fold increase in risk of having periodontitis compared to non-diabetics, hence adults with an hba1c level 0f 9%had significantly higher prevalence of severe periodontitis thus, the gingival inflammation and bleeding are intensified, greater prevalence and extent of pockets with twice as likely a non diabetics to have attachment loss (2,10,12). saliva contains numerous defense antioxidant proteins e.g. al and αam which able toinhibit the generation of free radicals (14). the highly significant increase in α-am level in cp patients as compared to control group revealed by this study are in accordance with other studies (15-19), the same result was found when comparing cp + t2 dm groups with control group, hence different researchers had reported that salivary α-am concentrations from t2dm patients were higher(11,20-22) or lower (23-26) than its levels in nondiabetics.the response of salivary gland to inflammatory diseases, resulting in enhanced synthesis and secretion of defense proteins (15). the increased basement membrane permeability of salivary glands in diabetics leads to increased passage of proteins into the saliva, moreover the sialosis in the parotid gland in t2 diabetics, hence most of α-am being synthesized in this gland, could result in variations in the salivary composition (22).studies showed that α – am is a major lipopolysaccharide binding protein of agri, gatibacteractinomycetemcomitansandporphyromo nasgingivalis (p.gingivalis) and interfere with bacterial adherence and biofilm formation also performs adirect inhibitory effect on the growth of neisseria gonorrhoeaand p.gingivalis(13). the notable increase in al level in cp patients in comparison with control subjects in this study was inconsistent with findings of previous studies (2729), while others (14,30)demonstrated decrease in al levels with deterioration of periodontal tissue condition. although the significant increase of al in t2 diabetics found by researchers (31,32) were in agreement with this study, but disagree with other results (33,34). al accounting for more than 50% of all plasma proteins, thus is regarded as markers for plasma protein leakage occurring as a consequence of inflammatory process, so the high salivary al level in cp patients due to ulceration in sulcular epithelium confirming the sulcular originof al from gcf, thus 4-5 times rise in al level was noted during periodontal tissue destruction when compared with that of the control (28),moreover the presence of treponemadenticola seemed to increase al in periodontitis patients (35). on the other hand, disregulation in the factors that regulate al synthesis during dm occur which include nutrition, hormonal balance and osmotic pressure and the inflammation of salivary gland causing increased leakage of serum proteins into the saliva (33). finally, studies measured a1 and α – am levels in t2 diabetics, they ignor their periodontal health status. the more acidic ph in cp patients was in line with some studies (29,36)hence, significant correlation did exist between ph and ppd on the other hand increase in ph was found (28,37) in cp patients. from the present study the decrease in ph of diabetics was coincide with other reports(12,25,38) hence, significant decrease in ph was demonstrated when comparing uncontrolled t2dm with healthy and controlled t2dm as well as, healthy withcontrolled t2dm (39). the decrease in salivary fr and bicarbonate content consequently contributed to the more acidic saliva(38). the higher concentrations of hydrogenions (from salivary glands or oral microbiota), thelowest the ph, since ph level negatively correlated with proportion of periodontal pathogens, that grow in mildly acidic ph, either utilize or create products that are mild to moderately acidic in nature (29). j bagh college dentistry vol. 28(1), march 2016 salivary α-amylase oral and maxillofacial surgery and periodontics 119 the decrease in salivary fr in this study coincide with others concerning cp (15,19,29), and dm (12,24,25,40) but diverge with previous studies about cp (37) and dm (41) who reported increased of fr, on the other hand some researchers found that fr levels not affected by periodontal health status (28) or presence of dm (42). there are multiple causes of salivary hypofunction including inflammation e.g. periodontal disease(19), hydrogen concentration, aging (40) or systemic disease e.g. dm (24), so in this case the decrease in ph, medication given for diabetics, poly urea and dehydration, neuropathies, microvascular changes, metabolic disturbances also, hypertrophy of salivary glands can be attributed to decrease in fr (12, 25). positive correlations of α –am and a1 with each other and with clinical periodontal parameters, but they were negative with fr and ph, this can be explained by the presence and increased inflammation with periodontal tissue destruction due to cp and dm which lead to increased levels of α-am and al but decrease in fr and ph. these results were in concurrent with other results (16,17,19) who found significant positive correlations between α-am with ppd and cal, while significant negative correlation with fr(19) in cp patients. in general, there were correlations between α – am with glycemic control (23,24,26), but non significant with fr at controlled and uncontrolled t2dm(23). significant positive correlation was detected between al levels with gi int2 diabetes (43). finally, the results may differ from one study to another these maybe due to e.g. the diversity in selection criteria of samples, metabolic control, wide range of age, different types of salivathat can limit direct comparison. references 1. newman mg, takei hh, klokkevold pr, carranza fa. carranza's clinical periodontology. 12th ed. st. louis mo: souaderselsvier; 2015. 2. mealey bl, oates tw. diabetes mellitus and periodontal disease. j periodontal 2006; 77:1289-303. 3. anil kn, neh b. saliva as adetective biofluid. international j med app sci 2015; 4. 4. diabetes care. diagnosis and classification of diabetesmellitus.american diabetes association. 2014; 37(1):14-80. 5. lang np, bartold pm, cullinam m, et,al., international classification work shop. consensus report: chronic periodontitis. annals periodontol 1999; 4: 53. 6. world health organization. who expert consultation. appropriate body mass index for asian populations and its implications for policy and intervention strategies. the lancet 2004; 363: 157163. 7. tenovuod. saliva. in textbook of clinical cardiology by thy lstrup a, fejerskov o. 2nd ed. copenhagen: munksgaard; 1994; 17.43. 8. silness p, loe h. periodontal disease in pregnancy. actaodontol sand 1964; 22:121. 9. loe h. the gingival index, the plaque index and the retention index system. j periodontal 1967;38(6): 610-6. 10. abdul-wahab ga, ahmed ma. assessment of some salivary enzymes levels in type 2 diabetic patients with chronic periodontitis (clinical and biochemical study). j baghdad coll dentistry 2015; 27(1):138-43. 11. prabal p, desai nt, kannan n, et al. estimation of salivary amylase, salivary total protein and periodontal microflora in diabetes mellitus. jida 2003;74:143-49. 12. sabir da, ahmed ma. assessment of salivary leptin and resistin levels in type 2 diabetic patients with chronic periodontitis (a comparative study). j baghdad college dentistry. j bagh coll dentistry 2015; 27(4):107-14 13. taylor jj.protein biomarkers of periodontitis in saliva.isrn. 2014, p.18. 14. miricescu d, greabu m, totan a, et al. the antioxidant potential of saliva: clinical significance in oral diseases. the pharmacol clin toxicol 2011; 15(2):139-43. 15. sanchez ga, v miozza, a delgado, et al. determination of salivary levels of mucin and amylase in chronic periodontitis patients. j of periodontal res. 2011; 46(2):221-7. 16. hady h, bertl k, laky m, et al. salivary and serum chromogranin a and amylase in periodontal health anddisease. jperiodontal 2012; 83(10): 1314-21. 17. sanchez ga, va miozza, a delgado, et al. relationship between salivary mucin or amylase and the periodontal status. oral dis. 2013; 19: 585-91. 18. swati k, rahul b, biju t, et al. estimation of levels of salivary mucin, amylase and total protein in gingivitis and chronic periodontitis patients. j. clin. diag. res. 2014; 8(10): zc 56-zc60. 19. andrea ba, aljandra kd, et al. comparison of salivary levels of mucin and amylase and their relation with clinical parameters obtained from patients with aggressive and chronic periodontal disease. j.appl. oral sci 2015; 23(3). 20. aydin s. acomparison of ghrelin, glucose, alphamylase and protein levels in saliva from diabetics. jbiochemistry and nuclear biol 2007; 40: 29-35. 21. sathyapriyas s, bharani go, nagalingam m, et al. potential of salivary proteins as a biomarkers in prognosis of diabetes mellitus. j pharmacy res 2011;4(7): 2228-29. 22. l malathi, kmk masthan, nbalachander, et al. estimation of salivary amylase in diabletic patients and saliva as a diagnostic toolin early diabetic patients. j clindiagn res 2013; 7(11): 2634-6. 23. artis sp, degwekar ss, bhwte rr. estimation of salivary glucose, salivary amylase, salivary total protein and salivary flow rate in diabetics in india. j oral sci 2010; 52:359-68. 24. al-zahawi shm, mahmood ha, al-qassab za. effects of diabetes mellitus type ii on salivary flow rate and some salivary parameters (total protein, glucose and amylase) in erbil city.j baghcoll dentistry 2012; 24(2): 123. j bagh college dentistry vol. 28(1), march 2016 salivary α-amylase oral and maxillofacial surgery and periodontics 120 25. prathibha km, johnson p, ganesh m, et al. evaluation of salivary profile among an adults type 2 diabetes mellitus in south india. j clin diagn res 2013; 7(8): 1592-5. 26. indria m, shekar pc, et al. evaluation of salivary glucose, amylase and total protein in type 2 diabetes mellitus patients. indian dental res 2015; 26: 271. 27. conclaves lr, soares mr, noqueira fc, et al. comparative proteomic analysis of whole saliva from chronic periodontitis patients. j of proteomics 2010; 73(7): 1334-41. 28. shaila m, pai gp, shetty p.salivary protein concentration, flow rate, buffer capacity and ph estimation: a comparative study among young and elderly subjects both normal and with gingivitis and periodontitis. j indian soc periodontol 2013; 17(1): 42-46. 29. gazy y, mohiadeen b, al-kasab z. an assessment of some salivary biochemical parameters in cigarette smokers with chronic periodontitis. j baghdad coll dentistry 2014; 26(1): 144-9. 30. scully dv, langley-evans sc. periodontal disease is associated with lower antioxidant capacity in whole saliva and evidence of increased protein oxidation. clin sci 2003;105(2):167-72. 31. doods mwj, chih –koyeh, dorthea a johnson. salivary alterations in type 2 (non-insulin dependent) diabetes mellitus and hypertension. community dental oral epi. 2000; 28:373-81. 32. vaziri pb, m vahedi, adollahzadeh sh, et al. evaluation of salivary albumin in diabetic patients. iranian j publ health 2009; 38(3): 54-9. 33. carda c, lioreda nm, salom l,etal.structural and functional salivary disorders in type 2 diabetic patients. med oral patoloral cir buccal 2006; 11: e 309-14. 34. hassan hr, abdul sattar a. influence of diabetes disease on concentration of total protein, albumin and globulins in saliva and serum: a comparative study. iraqi national of chemistry 2015; 15(1). 35. mahald y, tervahartiala t, et al. association of periodontal microorganisms with salivary proteins and mmp-8 ingingival crevicular fluid. j clinperiodontol 2012; 39(3): 256-63. 36. sharmila b, sangeeta m, rahul k. salivary ph: adiagnostic biomarker. j of indian society of periodontol 2013;17(4): 461-5. 37. ali bgh, ali oh. detection of salivary flow rate and minerals in smokers and non-smokers with chronic periodontitis (clinical and biochemical study). j baghdad coll dentistry 2012; 24(1):68-71. 38. eslami h, fakhrzadeh v, pakdel f, et al. comparative evaluation of salivary ph level in type ii diabetic patients and healthy subjects. visi j acemdic 2015(4):144-8. 39. arul asrikemath j, sanjay r, palaniveluperamachi. evaluation of correlation between salivary ph and prevalence of dental caries in subjects with and without diabetes mellitus. research j recent sci 2014; 3: 224-6. 40. hamad ai, alkiaisi ro, alkaisi ij. flow rates of resting whole saliva of diabetic patients in relation to age and gender. tikrit j dental sci 2012; 1: 1-5. 41. jose roberto c, regina marcia sp, fernando de oc, et al. salivary and microbiological parameters of chronic periodontitis subjects with and without type 2 diabetes mellitus: a case-control study. revodontol unesp 2014; 43(3). 42. collin hl, niskanen l, uusitupa m, et al. oral symptoms and signs in elderly patients with type 2 diabetes mellitus. a focus on diabetic neuropathy. oral surgoral med oral patholoral radiolendod 2000;90 (3): 299-305. 43. ben – aryeh h, serouya r, kanter y, et al. oral health and salivary composition in diabetic patients. j diabetes complications 1993; 7(1): 5762. j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 1 oxidative stress status in hypertensive patients on amlodipine treatment bahaa noor madhloom (1), ameena ryhan diajil (2) abstract background: oxidative stress may contribute to the etiology of hypertension in humans. oxidative stress is an imbalance between reactive oxygen species (ros) and antioxidant defense mechanisms, causing damage to biological macromolecules and dysregulation of normal metabolism and physiology. amlodipine as an antihypertensive agent is a long-acting calcium channel blocker that dilates blood vessels and improves blood flow. the aim of this study was to assess the oxidative stress in hypertensive patients on amlodipine treatment through the assessment of salivary malondialdehyde (mda) and superoxide dismutase (sod) as a marker of oxidative stress. material and method: 60 individuals were included in this study, divided into two groups; the first group composed of 30 hypertensive patients on amlodipine antihypertensive agent. the second group, the control group, composed of 30 healthy subjects without any systemic disease and with almost healthy oral hygiene. intraoral examination was done for each individual and salivary samples were collected with the salivary flow rate (f/r) which was calculated in ml per minute and ph was measured by ph meter. salivary mda and sod were analyzed by using elisa kit based on the principle of competitive enzyme immunoassay technique; the concentrations of markers were measured by spectrophotometer at 450nm in a microplate reader. results: salivary mda was significantly higher in hypertensive patients compared to control, while salivary sod was significantly lower in patients than control group. salivary flow rate and ph was significantly lower in patients as compared to the control group. conclusions: there is a relation between oxidative stress and hypertension. salivary mda and sod can be used as potential marker for monitoring patients with hypertension. keywords: hypertension, oxidative stress, amlodipine, mda and sod. (received: 10/1/2018; accepted: 11/2/2018) introduction hypertension is defined as a systolic blood pressure (sbp) of 140 mm hg or more, or a diastolic blood pressure (dbp) of 90 mm hg or more.(1) hypertension may be primary, which may be developed as a result of environmental or genetic causes, or secondary, which has multiple etiologies, including renal, vascular and endocrine causes.(2) primary or essential hypertension accounts for 90-95% of adult cases, while secondary hypertension accounts for only 2-10% of cases.(3) channel blocker dilates blood vessels and improves blood flow. it is a dihydropyridine calcium antagonist (calcium ion antagonist or slow-channel blocker) that inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle.(4) amlodipine (norvasc), one of the antihypertension agents, is a long-acting calcium; oxidative stress (os) is an imbalance between the generation of reactive oxygen species (ros) and nitrogen species (rns) and the antioxidant defense systems in the body.(5) under normal conditions, ros and the byproducts of their reactions with various biomolecules are neutralized and converted into harmless molecules by the natural antioxidant system. the antioxidant defense system is a highly complex biochemical organization that consists of numerous enzymes and a large number of scavenger molecules, the body’s pool of antioxidant molecules is derived from endogenous and exogenous sources.(6,7) superoxide dismutase (sod) has been identified as an endogenous antioxidant enzyme.(8) reactive o2is converted by sod into h2o2. in the next step, h2o2 is converted into h2o and o2 by salivary enzymes, catalase, peroxidase, and glutathione peroxidase.(9) among the many different aldehydes which can be formed as secondary products during lipid peroxidation, malondialdehyde (mda) propanol, hexanal, and 4-hydroxynonenal (4hne).(10) mda appears to be the most mutagenic product of lipid peroxidation.(11) it is an end-product generated by decomposition of arachidonic acid and larger polyunsaturated fatty acids.(12) once formed, mda can be enzymatically metabolized or react (1) master studentdepartment of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 2 on cellular and tissue proteins or dna to form adducts resulting in biomolecular damages.(12) mda is one of the most popular and reliable markers that determine oxidative stress in clinical situations(13) which is found to be contributed to the etiology of hypertension in humans.(14) also, hypertensive patients have impaired endogenous and exogenous antioxidant defense mechanisms.(15) materials and methods sixteen individuals were included in this study, divided into two groups. the first group composed of 30 hypertensive patients on amlodipine treatment. the second group (control) composed of 30 healthy subjects without any systemic disorder and they were almost with healthy oral hygiene. after explaining the experimental design and the purpose of the study, written informed consent was signed by each participant in this study. all patients were selected from al-manathera primary health center in al najaf city. after gathering information regarding age, sex, the dose of medication per day, family history of hypertension, oral soft tissue condition, burning mouth syndrome if existed, signs and symptoms of dry mouth, salivary samples were collected from individuals under the similar conditions. methods: intraoral examination was done using sterile dental mirror and probe with artificial light. the examination was performed systemically in the following sequence: • oral mucosa, examination of oral soft tissues was done in a sequence according to who (1997). • burning mouth syndrome according to (scala, et al., 2003). • signs and symptoms of dry mouth. the same dentist performed all examinations. a concordant diagnostic analysis was performed on 12 randomly selected patients by a second examiner. saliva samples were collected in restful and quiet circumstances. saliva's production during the first 2 minutes was discarded to avoid any possible contamination, spitting saliva into graduated test tubes. after the collection of adequate amounts of saliva (5 ml) according to the biological needs, the salivary f/r was calculated ml per minute. ph of salivary secretion was measured by ph meter. salivary samples were centrifuged at 3000×rpm for 15 minutes and then the clear supernatant was taken and transported frozen in ice crushed container to the laboratory and stored at -80c until analysis. 1estimation of salivary superoxide dismutase: 2the level of salivary superoxide dismutase was analyzed using commercially available, bg sod elisa kit. it was based on the principle of competitive enzyme immunoassay technique utilizing a monoclonal anti-sod antibody and an sod-horseradish peroxidase (hrp) conjugate. the intensity of color was measured spectrophotometrically at 450nm in a microplate reader. the sod concentration in each sample was interpolated from this standard curve. estimation of salivary malondialdehyde: the level of salivary mda was analyzed using commercially available bg mda elisa kit. it was based on the principle of competitive enzyme immunoassay technique utilizing a monoclonal anti-mda antibody and an mda-horseradish peroxidase (hrp) conjugate. the intensity of color was measured spectrophotometrically at 450nm in a microplate reader. the mda concentration in each sample was interpolated from this standard curve. 3statistical analysis: data were translated into a computerized database structure. an expert statistical advice was sought for study. statistical analysis was computer assisted using spss version 24 (statistical package for social sciences) association with excel version 5. the results were expressed as mean, standard deviation (sd). the differences between the groups were analyzed by using the student’s t-test and one-way anova with the post hoc tukey test and pearson’s correlation was applied to determine the relationships between the variables. the statistical significance was defined at a p value of <0.05. results age & gender hypertensive patients on amlodipine were with a mean age of 56.53 year (±2.161 sd); 16 were males (53%) and 14 were females (47%). the age range was (52-60) years. regarding control group, the mean age was 54.77 year (±3.339 sd); 15 were males and 15 were females. the age range was (50-63) years, table 1. j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 3 table (1): age range, mean and standard deviation of the study and control group groups n age range (years) mean age (year) ±sd pvalue control 30 50-63 54.77 3.339 >0.01 amlodipine 30 52-60 56.53 2.161 as shown in table 1, no statistically significant differences in mean age were found between patient and control group (p>0.01). salivary flow rate (f/r) & ph: both salivary flow rate & ph of hypertensive patients were found to be significantly lower than that of the control group, as shown in table 3. table (3): salivary flow-rate and ph of the study and control group. variables n mean ±sd std. error pvalue salivary flow rate (ml/min) control= 30 0.37 0.14 0.02 <0.01 patient= 60 0.21 0.10 0.01 salivary ph control= 30 6.71 0.13 0.02 <0.01 patient= 60 6.51 0.18 0.03 salivary malondialdehyde (mda) level: as shown in table 4, the mean salivary mda was significantly higher in hypertensive patients compared to the healthy individuals (p<0.01). mean salivary mda of the study group was (0.67µmol/m ±0.13 sd), while that of control group was (0.23 µmol/m ±0.06 sd). table (4): salivary malondialdehyde level of hypertensive patients & control. salivary malondialdehyde (µmol/m) n mean ±sd std. error pvalue control 30 0.23 0.06 0.012 <0.01 amlodipine patients 30 0.67 0.13 0.024 salivary superoxide dismutase (sod) level: as shown in table 5, the mean salivary sod was significantly lower in hypertensive patients compared to the healthy individuals (p<0.01). mean sod in the hypertensive patients was 0.55 µg/ml (±0.16 sd), while that of control group was 1.14 µg/ml (±0.07 sd). table (5): salivary superoxide dismutase level of hypertensive patients & control. salivary superoxide dismutase (µg/ml) n mean ±sd std. error p-value control 30 1.14 0.07 0.01 <0.01 amlodipine patients 30 0.55 0.16 0.03 regarding patients treated with amlodipine sod was significantly lower compared with control group (0.55, 1.14) (p<0.01) (table 5). in this study, a significant negative correlation was found between age of patients and saliva f/r (r= -0.61, p<0.01) (figure 1). also, a negative significant correlation was found between age of patients and salivary ph (r= 0.556, p<0.01) (figure 2). 6.2 0 6.4 0 6.6 0 6.8 0 7.0 0 40. 00 50. 00 60. 00 70. 00 80. 00 age (years) p h y=7.17-0.01*x r2 linear =0.310 figure (1): negative correlation between age and saliva f/r in hypertensive patients figure (2): negative correlation between age and salivary ph in hypertensive patients. 0. 10 0. 20 0. 30 0. 40 0. 40. 00 50. 00 60. 70. 80. 00 age (years) s a li v a f lo w r a te ( m l/ m in ) y=0.66-7.39 e–3*x r2 linear =0.372 j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 4 considering salivary markers, a significant positive correlation was found between age of patients and salivary mda level in hypertensive patients (r= 0.591, p<0.01), figure 3. the age of patients showed a significant negative correlation with salivary sod (r= -0.570 p<0.01) (figure 3). history of hypertension and study parameters the age range was 2-12 (years) and the mean was (6.3 years). there was a significant positive correlation between mda and history of hypertension (r=0.70, p<0.01). but a significant negative correlation was found between history of hypertension and sod (r=0.65, p<0.01), salivary f/r (r=0.53, p<0.01) and ph (r=0.56, p=0.01), table 6. table (6): correlation between history of hypertension and salivary parameters. variables pearson’s correlation (r) p-value amlodipine patient mda 0.70 <0.01 sod -0.65 <0.01 f/r ml/min. -0.53 <0.01 ph -0.56 <0.01 discussion hypertension, a serious medical problem, occurs when blood flows with force greater than normal. amlodipine is a dihydropyridine calcium antagonist inhibits the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle.(4) in this study, 30 patients who were previously diagnosed with hypertension were enrolled. those patients were under either amlodipine (16) years. generally, the age of hypertensive patients showed no statically significant difference from normotensive individuals (56.53, 54.77 years). however, hypertensive patients were older than normotensive control subject, which comes with the fact that hypertension is systemic disease mostly of old age.(16) salivary flow rate and ph in the present study, salivary f/r of hypertensive patients was significantly lower than normal control subjects (0.21, 0.37 ml/min). these findings are in agreement with böhm, et al., (1985)(17) who found that salivary f/r is lower in borderline hypertensives than in normotensives. the data support the assumption that in subjects with hypertension the parasympathetic influence on the salivary glands is reduced. however, amlodipine results in a decrease in renal vascular resistance and an increase in glomerular filtration rate.(19) also, as the salivary f/r decreases, the concentrations of total protein, sodium, calcium, chloride, and bicarbonate as well as the ph decrease to various levels, whereas the concentrations of inorganic phosphate and magnesium raise.(20,21) this disagrees with nimma, et al. (2016) (22) who found that there was no significant relation between hypertension and unstimulated salivary f/r. also, kagawa, et al., (2013) (23) found no significant correlation between either hypertension or intake of antihypertensive medication and unstimulated salivary f/r, which also disagrees with the current study. considering salivary ph, hypertensive patients significantly showed lower ph than normal control subjects (6.51, 6.71). this finding is similar to kagawa, et al., (2013)(23) who found a figure (3): positive correlation between age and mda of hypertensive patients. figure (4): negative correlation between age and sod of hypertensive patients. 0.30 0.40 0.7 0 0.90 40.0 0 50.0 0 60.0 0 70.0 80.0 age (years) m d a ( µ m o l/ m l) y=0.05+0.01* x r2 linear =0.349 0.50 0.60 0.80 0.20 0.40 1.00 40. 00 50. 00 60. 00 70. 00 80. 00 age (years) s o d ( µ g /m l) y=0.05+0.01*x r2 linear =0.349 0.60 0.8 0 1.20 https://www.ncbi.nlm.nih.gov/pubmed/?term=b%c3%b6hm%20r%5bauthor%5d&cauthor=true&cauthor_uid=3999634 j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 5 significant correlation between either hypertension or intake of antihypertensive medication and ph of unstimulated saliva. several studies have reported that the reduction in salivary f/r is also the cause of reduction in salivary ph/salivary buffering capacity in individuals (andrei, et al., 2015)(24) and the electrolytic concentration and tonicity of saliva decrease with decreasing salivary flow rates.(25) salivary markers salivary malondialdehyde level malondialdehyde is one of the most reliable markers that determine oxidative stress in clinical situations.(13) the mean salivary malondialdehyde was significantly higher in hypertensive patients compared to the apparently healthy individuals. this agrees with al-rawi, et al., (2008)(26) who found that mda level was significantly higher in hypertensive patients than that in healthy individual. also, ahmad et al., (2013)(27) found that the mda levels was significantly increased in the hypertension groups as compared to those of the control group. further, nwanjo et al., (2007)(28) and mahdi et al., (2002)(29) demonstrated an increase in the mda levels in the essential hypertension cases. this can be attributed to ros which contributes to the etiology of hypertension in humans.(14) superoxide anion is produced by stimulation of the angiotensin ii/angiotensin ii type i receptor and nicotinamide adenine dinucleotide phosphate-oxidase (nadph) oxidase by angiotensin ii which in turn contribute in oxidation process products.(30) in human with hypertension, ros may increase due to a diminution of the activity of antioxidant enzymes(31) which could lead to increase oxidation process and in turn increasing lipid peroxidation process and its products (mda). salivary superoxide dismutase level the mean salivary sod was significantly lower in hypertensive patients compared to the apparently healthy individuals. this agrees with ahmad, et al., (2013)(27) who found that the activities of sod was significantly lower in the hypertensive patients as compared to those in normotensive subjects. the data support the assumption that subjects with hypertension have impaired endogenous and exogenous antioxidant defense mechanisms.(15) also, hypertensive patients have reduced activity and decreased content of antioxidant enzymes, including super oxide dismutase, glutathione peroxidase, and catalase.(32) this disagrees with al-rawi, et al., (2008)(26) who found that sod level was significantly higher in hypertensive patient than that of normotensive one. considering the correlation between age and salivary f/r, a significant negative correlation was found between age of patients and salivary f/r and this agrees with heintze , et al., (1983);(33) pendersen, et al., (1985);(34) cowman, et al., (1994);(35) michael, (1998)(36) who found that a reduction in salivary f/r with aging, but disagrees with heft., et al., (1984)(37) who found that there was no significant correlation between age and salivary f/r. this could be due to the effect of antihypertensive medications.(19) also, this may be attributed to the effect of aging process on physiological homeostasis which can be separated in to two different major pathways, primary and secondary aging as proposed by busse, (1997).(38) according to narhi, et al., (1992)(39) the concept of primary aging (chronological) is an alteration in physiological function with advancing age and is independent of extrinsic of physical and psychological disturbances such as stress, trauma and disease. yet, secondary aging implies the result of external influences including systemic diseases and therapeutic treatment. it is wellrecognized that alteration of salivary function in the elderly are commonly associated with age related diseases (secondary aging). since the reduction in salivary f/r could be a cause of reduction in salivary ph/salivary buffering capacity in individuals.(24) so, a negative significant correlation was found between age of patients and salivary ph. a significant positive correlation was found between age of patients and salivary mda level in hypertensive patients. however, the age of patients showed a significant negative correlation with salivary sod. these findings suggested that increased lipid peroxidation in patients may be caused by increased free radical production and/or decreased antioxidant defense, which agrees with the previous studies gonca akbulut, et al., (1999);(40) mine erdeni̇nal, et al., (2001);(41) ramazan ozcankaya, et al., (2002);(42) ümit mutlu türkoğlua, et al., (2003)(43) which hypothesized that increased oxidative stress may play an important role in the aging process or versa verse. furthermore, ramazan et al., (2002)(42) concluded that increased mod level is a result of aging so that lipid peroxidation increases due to aging. gonca, et al., (1999)(40) suggested that increased levels of lipid peroxidation products may play a role in aging. mine erdeni̇nal et al., (2001)(41) and ümit, et al.,(2003)(43), hypothesized that higher http://europepmc.org/search;jsessionid=cfe3f69af426695100cbb1fc683ca6b3?query=auth:%22heintze+u%22&page=1 http://www.sciencedirect.com/science/article/pii/s0009898100004228#! http://www.sciencedirect.com/science/article/pii/s0009912003000353#! http://www.sciencedirect.com/science/article/pii/s0009912003000353#! http://www.sciencedirect.com/science/article/pii/s0009898100004228#! http://www.sciencedirect.com/science/article/pii/s0009912003000353#! j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 6 level of os plays an important role in the aging process of individual. a significant positive correlation was found between history of hypertension and salivary mda level in hypertensive patients suggests a relation between increased oxidative stress and hypertension which is in agreement with am et al., (2007)(44) who reported an association between increased oxidative stress and higher blood pressure. a significant negative correlation was found between history of hypertension and sod which could be attributed to the fact that hypertensive patients have reduced activity and decreased content of antioxidant enzymes.(32) also, the decrease in the antioxidant enzymes could be due to their inactivation as the result of a continuous exposure to hydrogen peroxide, hydrogen peroxynitrite and other free radicals.(45) moreover, a significant negative correlation was found between history of hypertension and salivary f/r, this could be the effect of aging.(38) also a significant negative correlation was found between history of hypertension and salivary ph, this could be due to the reduction in salivary f/r which could be due to reduction in salivary ph/salivary buffering capacity in individuals.(26) conclusion 1. over production of the free-radicals may lead to increased oxidative stress which leads to oxidative damage to the biological molecules, leading to several chronic diseases. 2. salivary mda increases in hypertensive patients which represent an increasing in oxidative process. 3. salivary sod decreases in hypertensive patients which represent a decrease in antioxidant enzyme system. 4. salivary f/r & ph are negatively associated with hypertension due to the effect of antihypertensive medications or in hypertension the parasympathetic influence on the salivary glands is reduced. 5. this study recommends anti-oxidant supplements for patients with hypertension along with antihypertension medications. references 1benjamin ej., blaha mj, chiuve se. for the american heart association statistics committee and stroke statistics subcommittee. heart disease and stroke statistics-update: a report from the american heart association. circulation. 2017;7:135:e146-e603. 2poulter nr, prabhakaran, d, caulfield m. 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(1994). saliva. in: thylstrup a, fejerskov o. textbook of clinical cariology. 2nd ed. copenhagen: munksgaard. 22nimma v, talla h, poosa m, gopaladas m, meesala d, jayanth l. influence of hypertension on ph of https://www.ncbi.nlm.nih.gov/pubmed/?term=b%c3%b6hm%20r%5bauthor%5d&cauthor=true&cauthor_uid=3999634 https://www.ncbi.nlm.nih.gov/pubmed/?term=van%20baak%20m%5bauthor%5d&cauthor=true&cauthor_uid=3999634 https://www.ncbi.nlm.nih.gov/pubmed/?term=van%20hooff%20m%5bauthor%5d&cauthor=true&cauthor_uid=3999634 https://www.ncbi.nlm.nih.gov/pubmed/?term=moy%20j%5bauthor%5d&cauthor=true&cauthor_uid=3999634 https://www.ncbi.nlm.nih.gov/pubmed/?term=rahn%20kh%5bauthor%5d&cauthor=true&cauthor_uid=3999634 https://www.ncbi.nlm.nih.gov/pubmed/?term=rahn%20kh%5bauthor%5d&cauthor=true&cauthor_uid=3999634 j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 7 saliva and flow rate in elder adults correlating with oral health status. j clin diagn res. 2016;10:zc34–zc36. 23kagawa r, ikebeb k, enoki k, murai s, okada t, matsuda k, maeda y. influence of hypertension on ph of saliva in older adults. oral dis. 2013;19:525-529. 24prodan a, brand hs, ligtenberg aj, et al. interindividual variation, correlations, and sexrelated differences in the salivary biochemistry of young healthy adults. eur j oral sci. 2015;123:149157. 25bardow a, madsen j, nauntofte b. the bicarbonate concentration in human saliva does not exceed the plasma level under normal physiological conditions. clin oral investig. 2000;4:245. 26al-rawi n, jaber f, atiyah k. assessment of salivary and serum oxidative stress and antioxidants as plausible parameters in prediction of ischemic stroke among iraqi samples. the internet journal of third world medicine. 2008;7. 27ahmad a, singhal u, hossain mm, islam n, rizvi i. the role of the endogenous antioxidant enzymes and malondialdehyde in essential hypertension. j clin diagn res. 2013;7987-990. 28nwanjo hu, oze g, okafor mc, nwasu d, nwankpa p. oxidative stress and non enzymic antioxidant status in hypertensive patients in nigeria. afr. j. biotechnol. 2007;6:1681–1684. 29mahdi aa. a, (2002). textbook of biochemistry by s.p singh. 3rd edn. new delhi: cbs publishers and distributors. free radicals and other antioxidant; pp. 545–55. 30bonomini f, rodella lf, rezzani r. metabolic syndrome, aging and involvement of oxidative stress. aging dis. 2015;6:109-120. 31pedro-botet j, covas mi, martin s, rubies-prat j. decreased endogenous antioxidant enzymatic status in essential hypertension. j hum hypertens. 2000;14:343–345. 32saez gt, tormos c, giner v, chaves j, lozano jv, iradi a, redon j. factors related to the impact of antihypertensive treatment in antioxidant activities and oxidative stress by-products in human hypertension. am j hypertens. 2004;17:809–816. 33heintze u , birkhed d , björn h. secretion rate and buffer effect of resting and stimulated whole saliva as a function of age and sex. swed dent j. 1983;7:227-238. 34pendersen w, schuber m, izutsu k, mersai t, truelove e. age-dependent decrease in human submandibular gland flow rate as measured under resting and post-stimulation condition. j dent res. 1985;64.882-825. 35cowman ra, frisch m, lasseter cj, scarpace pj. effects of beta-adrenergic antagonist on salivary secretory function in individuals of different ages. j gerontol. 1994;49:b208-b214. 36yeh ck, johnson da, dodds mw. impact of aging on human salivary gland function: a communitybased study. aging (milano). 1998;10:421–428. 37heft mw, baum bj. unstimulated and stimulated parotid salivary flow rate in individuals of different ages. j dent res. 1984;63:1182–1185. 38busse ew: theories of aging in busse e.w., pfeiffer e. (1997). behavior and adaption in later life. little, brown and company, boston, pp.8-30. 39narhi to, meurman jh, ainamo a, et al. association between salivary flow rate and the use of systemic medication among 76-81 and 86 years old inhabitants in helsinki, finland. j dent res. 1992;71:1875-1880. 40gonca akbulut k, gönül b, akbulut h. differential effects of pharmacological doses of melatonin on malondialdehyde and glutathione levels in young and old rats. gerontology. 1999;45:67-71. 41inal me, kanbak g, sunal e. antioxidant enzyme activities and malondialdehyde levels related to aging. clin chim acta. 2001;305:75–80. 42ozcankaya r, delibas n. malondialdehyde, superoxide dismutase, melatonin, iron, copper, and zinc blood concentrations in patients with alzheimer disease: cross-sectional study. croat med j. 2002;43:28–32. 43mutlu-türkoğlu u, ilhan e, oztezcan s, kuru a, aykaç-toker g, uysal m. age-related increases in plasma malondialdehyde and protein carbonyl levels and lymphocyte dna damage in elderly subjects. clin biochem. 2003;36(5):397–400. 44armas-padilla mc, armas-hernández mj, sosacanache b, et al. nitric oxide and malondialdehyde in human hypertension. am j ther. 2007;14:172– 176. 45kedziora-kornatowska k, czuczejko j, pawluk h, et al. the markers of oxidative stress and activity of the antioxidant system in the blood of elderly patients with essential arterial hypertension. cell mol biol lett. 2004;9:635–641. الخالصة: دضغط اوعي ادمت و عاد ي وضغ ا ت ش غم تمغ ش ادلغم اد همغمي و يم ارتفاع ضغط ادم و اد ضغا اد ي ون ه ا ارتفاع تمغ همغي ن اد فايي عأد ادمهاع ضغم االهمغمتس تمغرر ضغ ر أ ادم عيم ان يا هم ادت ي اض اووضغ عاد ا ف اد ر ت عاد از ب ن أن اع اال ينم ادنادن ادرل ي ش دييممش ادلم اد هممي ت نن ا وماوم هم اسراب ارتفاع ضط ادم و يالج ومغغغ م د تادي ارتفاع ضغغغط ادم س وت ط ه نر دلنات ادنادمغغغ د ودي ادال ت سغغغت االعي ادمت و amlodipineات ي دب ن عو من س وا ادم ش هتالج تن amlodipineضغال اد اغاب ن بارتفاع ضغط ادم عومغ مت االت ي دب ن تل م ادلغم اد همغمي هم اد اد مف تن ادمراسغ هم اديتابش sod ع انزوم سر ر أعهم م دس تز mda خالل ق اس تم ى تاد نمادمو اوم ت وض تاغاب (30( غ ي اقم ع تلمغ ن ادال تي ي ن اد ي ي االعدال ت ن تن 60و ادمراسغ تودف تن :اد اد عاد ول ( غ سغي م يغ اش تم ه ادفم دنط ه دس عاخ ن ج 30بارتفاع ضغط ادم عومغ م يالج االت ي دب نش اد ي ي ادنان ت ن تن م تن اديتاب دل اس ه اديتاب اد ف ز باد يي /دق ل ع ضغغ اديتابش تم ق اس تمغغ ى تاد نمادمو اوم ع انزوم سغغر ر أعهمغغ م دسغغ تز ه نان ت ش 450اديتاب باس ما ت ي ط اد ما عق اس ه اد ه ز باس ما تل اس اد ف ادي نم https://www.ncbi.nlm.nih.gov/pubmed/23279167 http://europepmc.org/search;jsessionid=cfe3f69af426695100cbb1fc683ca6b3?query=auth:%22heintze+u%22&page=1 http://europepmc.org/search;jsessionid=cfe3f69af426695100cbb1fc683ca6b3?query=auth:%22birkhed+d%22&page=1 http://europepmc.org/search;jsessionid=cfe3f69af426695100cbb1fc683ca6b3?query=auth:%22bj%c3%b6rn+h%22&page=1 j bagh college dentistry vol. 32(1), march 2020 oxidative stress status 8 اد ي ط اإل اغادم ديل اسغاض اع م انا تمغ ى تاد نمادمو اوم هم دتاب ت ضغال ادضغط اييال بنن تن اال غ اي ادمغي ن شب ن ا :ادن ي ال ادضغط تلارنا باويغ ا س ه وا اديتاب عتمغ ى اد ضغ اقط هم ت ضغال انزوم سغر ر أعهمغ م دسغ تز اقط هم دتاب ت ضغ ارتفاع ضط ادم تلارن باو اي االي ا ش االسغ ن اج وناد يالق ب ن ادلغم اد همغمي عارتفاع ضغط ادم ع تمغ ى تاد نمادمو اوم ع انزوم سغر ر أعهمغ م دسغ تز هم اديتاب و نن ا ت ابتا اد ضال اد ااب ن بارتفاع ضط ادم ش وم م هتالتا هم eman f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 nutritional status pedodontics, orthodontics and preventive dentistry114 nutritional status in relation to oral health status among patients attending dental hospital eman k. chaloob, b.d.s., m.sc. (1) alhan a. qasim, b.d.s., m.sc. (1) abstract background: good nutrition is essential for oral and dental health in children. good eating habits and food preferences are established early in childhood. oral health problems can effect dietary quality and nutrient intake in another side increase the risk of several systemic diseases., the aim of the present study was to investigate the relation or the effect the of nutritional status in children at age of 5 to16 on the oral health status and dental caries . materials and methods: the total sample composed of 153 patients attending the pedodontic and preventive department/college of dentistry/university of baghdad, the assessment of nutritional status was performed by using body mass index specific for age and gender according to chronic disease and prevention center (cdc) growth chart (2000). ramfjord index teeth were applied to assess oral cleanliness and gingival condition, dental plaque and gingival health condition was assessed by using plaque index of silness and loe(1964),and gingival index of loe and silness( 1963), calculus index assessment was according to ramfjord criteria (1959). dental caries measurement was according to world health organization criteria (1997). results: this study showed no significance in the nutritional status (bmi) of children at 5-16 years of age and plaque index, gingival index, and calculus index, as well as the correlation of significant differences was not found between the nutritional status (bmi) and caries experience. conclusion: this study reflected that the oral hygiene, gingival health and dental caries were not affected by nutritional status of children at age of 5-16years. keywords: nutrition status, oral health status, dental caries, gingival health. (j bagh coll dentistry 2013; 25(special issue 1):114-119). introduction oral health problems continues to be one of the most common infectious disease known, despite widespread preventive measure, this disease exerts a social, physical, mental and financial burden on a global scale especially in developing countries (1,2). epidemiological studies in different parts of the world agree that this disease is the most prevalent dental problem in childhood and adolescent (3). it is becoming increasingly evident that food and nutrient intake throughout the life exerts a profound influence on the level of health as well as the susceptibility to a wide variety of disease, including those of oral cavity (4). tooth calcification and development could be affected by nutritional imbalance, nutrition could have a strong impact on oral health and there is no question about the importance of childhood nutrition on children’s health (5). the body mass index has always been considered a simple method for analysis of the nutritional status, recently, studies have been conducted to assess the association of the body mass index and periodontitis. kumar et al (6) and study by willershausen et al (7) observed a significant association between oral health status and the bmi, whereas moreira et al study found no correlation(8). (1) lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. though no definite mechanism of association between bmi and periodontitis is identified, it has been ascribed to unhealthy dietary patterns with insufficient micronutrients and excess sugar and fat content. these dietary patterns could thus pose a risk both for periodontal disease and obesity (9). studies by ekuni et al. (10) and reeves et al (11), have included either young or old subjects or data from those studies on both the young and adult individuals had suggested that periodontal status deteriorates with bmi. several iraqi studies were conducted concerning the assessment of nutritional status among different age groups of children and different geographical location, results showed that nutritional status may affect the oral health (12-19). the aim of the present study was to investigate the effect of nutritional status on the oral hygiene, gingival health and dental caries among patients at age of 5 to 16 years old attending dental hospital in preventive and pedodontic department. materials and methods the final sample size comprised of 153 patients aged 5 to 16 years, attending dental hospital / university of baghdad /pedodontic and preventive department. body mass index (bmi) reflected the nutritional status of the sample collected, it is a number calculated from child's weight and height j bagh college dentistry vol. 25(special issue 1), june 2013 nutritional status pedodontics, orthodontics and preventive dentistry115 name as anthropometric measurement included measurement of weight and height according to trowbidge (20). the height of the participants was measured in centimeters, using a hard ruler installed vertically and secured with a stable base, while weight was assessed in kilograms using a mechanical scale. the bmi was calculated as the ratio of the subject's body weight (in kg) to the square of their height (in meters), according to this formula; bodyweight / (height)2=bmi (kg)/m2 (21) three categories were defined: underweight (bmi < 5th), normal weight (bmi 5-85th), overweight risk (bmi > 85th) (22). oral examination was performed by a single examiner using mouth mirror and dental explorer for each subject, caries experience was recorded according to who criteria ,decayed ,missing ,filled index (dmfs, dmfs for permanent and primary teeth respectively) (23). dental plaque was assessed by using plaque index (pll) of silness and loe (24), gingival health condition was assessed by loe and silness (25), calculus was scored utilizing the criteria set by ramfjord (1959) (26), ramfjord index teeth were examined to represent the whole dentition.(26). the severity of oral hygiene was assessed according to the classification introduced by loe and silness (1963) in to negative, mild, moderate and severe condition. data analysis was computer aided. p value less than the 0.05 level of significance was considered statistically significant. for normally distributed variables the significance of difference between more than 2 groups was assessed by anova, while independent sample t-test was used to assess the statistical significance of difference in mean between 2 groups. the statistical significance, strength and direction of linear correlation between 2 quantitative variables (one of which being non-normally distributed) was assessed by spearman's rank linear correlation (27). results table (1) illustrates the distribution of the total sample according to age, gender, and percentiles, a total sample of (153) 5-16 yearold children attending dental hospital was examined in this study. the distribution according to age group was divided in three groups (5-8) years old, (9-12) and (13-16) years old. gender was distributed as a male represent highest than female, the distribution according to the bmi percentile the majority of the patients was under the category of normal weight. table (2) shows that the severity of pli, gi, cali in the present study divided in to negative, mild, moderate and severe conditions, the calculus index was negatively recorded represent 116(75.8%). the significance difference between age and gender with body mass index (bmi) is shown in table (3), the age group (9-12) years old was represent the highest number of underweight, for all age groups the significant difference was not found. in the same table the relation of body mass index (bmi) to gender was illustrated, the majority of males and females were under the category of normal weight ,but the difference was not significantly related. table (4) shows the difference in mean oral hygiene (pli, gi, cali) by body mass index(bmi) the significant difference was not found, the highest mean difference in plaque, gingival and calculus index was recorded in relation to overweight risk(> 85th). table (5) was demonstrates the difference in mean oral hygiene (pli, gi and cali) by age groups the significant difference was not found. mean difference of pli was represent the highest number was at age of 1316 years old, while the mean difference of gi was represent the highest number at age of 5-8 years .the cali represent the highest mean difference at age of 9-12 years old. the same table illustrates that the mean difference of oral hygiene (pli, gi, cali) for the female and male was not significant, the highest mean difference of plaque index was 1.1 in male. table (6) shows that the mean difference of caries experience in relation to age, gender and body mass index (bmi), the significant difference was not found, in relation to age group the mean dmfs was recorded the highest at age of 13-16 years old, while the mean dmfs recorded the highest at age of 5-8 years old. the highest mean difference of dmfs according to gender for female, while the highest mean difference of dmfs was for male. in the same table the overweight risk (>85th) represent the highest mean difference of dmfs and dmfs but the significant was not found. discussion this study was designed to investigate the oral health status of children aged 5-16 year-old attending peadodontic and preventive department dental hospital /university of baghdad in order to provide a reliable data. this sample has been chosen to explore the dental health of primary and permanent teeth as there is many previous epidemiological study concerning oral health status and dental caries in relation to nutritional status. in iraq, several previous studies were j bagh college dentistry vol. 25(special issue 1), june 2013 nutritional status pedodontics, orthodontics and preventive dentistry116 conducted on oral health condition, particularly in relation to nutritional status (13,15-18). childhood nutrition is known to have a considerable impact on children's health, and the most important on growth and energy provision (28,29).oral health status is the commonest diseases in the world, it could be related to diet in many way however, the most significant effect of nutrition on teeth is the local action of diet in the mouth on the development of oral diseases (30) .the body mass index is a number calculated from child's weight and height. bmi is an inexpensive and easy perform method of screening for weight categories (31).this study showed the distribution of the pli, gi and cali according to severity, the majority of the sample had mild and moderate pli and gi while the cali commonly represent the negative, this could be related to the age group of sample was selected was coming to treat their oral health problems. several previous epidemiological iraqi studies concerning the oral hygiene with different age group and different geographic area (15, 18, 32-38). in this study the majority of children had normal weight according to age and gender groups this could be related to the nutritional source of iraqi people. as well as the age group of 9-12 years old represent the majority of normal weight this could be related to the sample size was commonly at this age group distributed. the effect of the nutritional factors in the development of periodontal diseases still unclear, so numerous studies carried out to compare the prevalence of gingivitis between well and malnourished children produced different results (41,42). the present study showed no significance in the nutritional status in according to plaque, gingival and calculus indices this may be attributed to oral health problems are multifactorial disease, dealing with tooth brush, brushing teeth, visiting the dentist and could be the diet. other researchers reported the significant was not found between the oral health and nutritional status (15,16,18,).on the other hand others who reported that malnutrition can cause a rise in the prevalence of oral health problems (1, 13, 14) . in the present study the oral hygiene not affected by the age and gender, the age and gender factors could not affect the oral health status as only one factor, and the age range of the present study was higher in compare to the sample size. many studies were concluded that the oral health status is directly correlated with age and gender (23,38). other studies showed no statistical difference in the prevalence of oral health status with age and gender (32, 33, 35). dental caries are known to be multifactorial disease involving several elements, oral microflora (acidogenic bacteria), dietary exposures (fermentable carbohydrates), as well as susceptible host (physio chemical, composition of saliva, quality of the tooth), and sufficient time (39,40).the significant was not found between age, gender, nutritional status and caries experience, as a result of this study, this could be explain by that the collection of sample in this study was came from different part of iraq community, so they well differ in their habit, knowledge and behavior. other studies found that caries scores are reported to increase with age (32,34,37). many studies found that malnourished individuals were more susceptible to dental diseases, as it interacts with dental composition, morphology and eruption time of tooth (41, 42). references 1. cameron a, widmer r. handbook of pediatric dentistry. 3rd ed. mosby elesvir; 2008. 2. fejerskov o, kidd e. dental caries (the disease and its clinical management). blackwell, munksgward. 2008. 3. damle sg. text book of pediatric dentistry. 3rd ed. new delhi: darya 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ramfjord sp. indices for prevalence and incidence of periodontal disease. j periodontal 1959:30:51-9 27. sorlie de. medical biostatistics and epidemiology: examination and board review. 1st ed. norwalk, connecticut: appleton and lange, a simon & schuster co.; 1995. pp. 47-88. 28. murray j, nunn j, steel j. the prevention of oral disease. 4th ed. newyork: oxford; 2003. 29. marshall ta. caries prevention in pediatrics: dietary guidelines. quintessence int 2004; 35(4): 332-5. 30. gil-montoya ja, subirá c, ramón jm, gonzálezmoles ma. oral health-related quality of life and nutritional status. j public health dent 2008; 68(2):88-93. 31. komiya h, masubuchi y, mori y, tajima n. the validity of body mass index criteria in obese school aged children. tohoku j exp med 2008; 214(1): 2737. 32. el-samarrai sk. oral health status and treatment needs among preschool children. master thesis, college of dentistry, university of baghdad, 1989. 33. al-azawi la. oral health status and treatment needs among iraqi five-years old kindergarten children and fifteen-years old students (a national survey). ph.d. thesis, college of dentistry, university of baghdad, 2000. 34. ahmed z. oral health status and treatment needs among institutionalized iraqi children and adolescent in comparison to school children and adolescent in iraq. master thesis, college of dentistry, university of baghdad, 2002. 35. mubarak d. oral health status and treatment need among eight years old school children in urban and rural areas in baghdad –iraq. master thesis, college of dentistry, university of baghdad, 2002. 36. abdul razzaq q. oral health status among 15 year-old school students in sulaimania city-iraq. master thesis, college of dentistry, university of baghdad, 2007. 37. baram a. oral health status and treatment needs among primary schoolchildren in sulaimani city. master thesis, college of dentistry, university of baghdad, 2007. 38. al-obaidi ej. oral health status and treatment needs among 15 yearold students in al-diwania governorate-iraq. master thesis, college of dentistry, university of baghdad, 2008. 39. warren jj, weber-gasparoni k, marshall ta, drake dr, dehkordi-vakil f, kolker jl, dawson dv. factors associated with dental caries experience in 1year-old children. j public health dent 2008; 68(2): 70-75. 40. wakai k, naito m, naito t, kojima m, nakagaki h, umemura o, yokota m, hanada n, kawamura t. tooth loss and intake of nutrients and foods: a nationwide survey of japanese dentists. community dent oral epidemiol 2010; 38: 43-49. 41. buttriss j. nutrition, health and school children. br nutrition foundation nutrition bulletin 2002; 27(4): 275-316 (ivsl). 42. van gemert-schriks mc, van amerongen ew, aartman ih, wennink jm, ten cate jm, de soet jj. the influence of dental caries on body growth in prepubertal children. 2011; 15(2): 141-149. (ivsl). j bagh college dentistry vol. 25(special issue 1), june 2013 nutritional status pedodontics, orthodontics and preventive dentistry118 table 1: frequency distribution of the study sample by age, gender and bmi for age and gender percentiles n % age group (years) (5-8) 50 32.7 (9-12) 88 57.5 (13-16) 15 9.8 gender female 74 48.4 male 79 51.6 bmi percentile groups underweight (<5th) 35 22.9 normal (5th-85th) 102 66.7 overweight risk (>85th) 16 10.5 total 153 100 table 2: distribution of oral hygiene according to severity severity plaque gingivitis calculus n % n % n % negative 10 6.5 15 9.8 116 75.8 mild 60 39.2 50 32.7 19 12.4 moderate 76 49.7 76 49.7 17 11.1 severe 7 4.6 12 7.8 1 0.7 total 153 100 153 100 153 100 table 3: the distribution of patients by age and gender according to nutritional status bmi percentile bmi z score(<-2) underweight (<5th ) normal (5th -85th ) overweight risk (>85th ) total n % n % n % n % range mean se age group (yeas) (5-8) 12 24 36 72 2 4 50 100 (-4.4 to 2.6) -0.8 0.2 (9-12) 20 23 54 61.4 14 15.9 88 100 (-4 to 2.6) -0.5 0.2 (13-16) 3 20 12 80 0 0 15 100 (-2.4 to 0.9) -0.5 0.3 difference [ns] gender female 20 27 44 59.5 10 13.5 74 100 (-3.7 to 2.6) -0.6 0.2 male 15 19 58 73.4 6 7.6 79 100 (-4.4 to 2.6) -0.6 0.2 difference [ns] table 4: the difference in mean plaque, gingival and calculus indices by bmi percentile groups plaque index gingival index calculus index underweight (<5th) range (0 2.1) (0 2) (0 1.87) mean 1.06 0.91 0.17 se 0.09 0.1 0.08 n 35 35 35 normal (5th-85th) range (0 2.12) (0 2.6) (0 2) mean 1.05 0.99 0.21 se 0.05 0.06 0.05 n 102 102 102 overweight risk (>85th) range (0 1.9) (0 1.9) (0 1.2) mean 1.07 1.19 0.24 se 0.15 0.12 0.11 n 16 16 16 difference [ns] [ns] [ns] j bagh college dentistry vol. 25(special issue 1), june 2013 nutritional status pedodontics, orthodontics and preventive dentistry119 table 5: the difference in mean plaque, gingival and calculus indices by age and gender groups plaque index gingival index calculus index a ge group (years) (5-8) mean 1.05 0.98 0.17 se 0.07 0.09 0.06 n 50 50 50 (9-12) mean 1.05 1 0.23 se 0.06 0.07 0.05 n 88 88 88 (13-16) mean 1.09 0.96 0.17 se 0.14 0.13 0.13 n 15 15 15 differences [ns] [ns] [ns] g enders female mean 1.01 0.99 0.27 se 0.06 0.08 0.06 n 74 74 74 male mean 1.1 0.99 0.15 se 0.07 0.06 0.04 n 79 79 79 differences [ns] [ns] [ns] table 6: the difference in mean dmfs and dmfs by age group, gender and bmi percentile dmfs dmfs range mean se n p range mean se n p age group (years) (5-8) (0 to 17) 2.8 0.6 50 [ns] (0 to 30) 9.7 1 50 [ns] (9-12) (0 to 19) 6.5 0.5 88 (0 to 25) 8.9 0.7 88 (13-16) (1 to 20) 9.9 1.3 15 (0 to 18) 3.5 1.5 15 genders female (0 to 20) 5.8 0.6 74 [ns] (0 to 30) 8.6 0.8 74 [ns] male (0 to 19) 5.5 0.6 79 (0 to 25) 8.7 0.8 79 bmi percentile group underweight (<5th) (0 to 20) 5.5 0.9 35 [ns] (0 to 30) 9.9 1.3 35 [ns] normal (5th-85th) (0 to 19) 5.5 0.5 102 (0 to 25) 8 0.7 102 overweight risk (>85th) (0 to 14) 7.1 1.2 16 (0 to 25) 10.3 1.9 16 abeer f.doc j bagh college dentistry vol. 25(3), september 2013 the relationship among pedodontics, orthodontics and preventive dentistry115 the relationship among bite force with facial dimensions and dental arches widths in a sample of iraqi adults with class i skeletal and dental relations abeer b. mahmoud, b.d.s., m.sc. (1) abstract background: this study aimed to determine whether there is a relationship among the bite force with facial dimensions and dental arches in a sample of iraqi adults with class i skeletal and dental relations. materials and methods: forty dental students (20 males and 20 females) were selected under certain criteria. for those individuals, dental impressions, frontal facial photographs and maximum bite force at molar and incisor regions were taken. the dental arches widths and facial dimensions were measured using the autocad program 2007, while the bite force was determined using special device. descriptive statistics for the measured variables were performed and gender difference was determined using independent sample t-test, while the relation among bite force and facial dimensions and dental arches widths was determined by pearson’s correlation coefficient test. results: the results indicated that bite force, facial dimensions and dental arches widths were higher in males than females with a non-significant genders difference for the bite force and upper inter-canine width, while with a high significant genders difference for the other measurements. pearson’s correlation coefficient revealed non-significant correlation among the bite force and facial dimensions and dental arches widths. conclusion: this study proved that there was no relationship among the bite force with facial dimensions and dental arches widths. key words: bite force, dental arches widths, facial dimensions. (j bagh coll dentistry 2013; 25(3):115-120). introduction bite force is the force exerted by the masticatory musculature during biting, measured between particular occluding teeth (1). many factors affect the maximum bite force. bakke et al. (2) reported a significant positive correlation between the maximum bite force and the number of teeth presents. one way to explain the correlation between occlusal contacts and bite force is that good occlusal support (i.e. force distributed over many teeth) may result in stronger or more active jaw elevator muscles that can develop higher bite force. another explanation could be that strong elevator muscles, with resulting harder biting and vigorous function, cause better occlusal contact support and increased number of contacts. both explanations are probably relevant. bakke et al. (3) and ferrrario et al. (4) found that there is a close positive relationship between the bite force and the electromyographic activity of the jaw elevator muscles (the temporal, the masseter, and the medial pterygoid muscles) during isometric contraction. the effect of craniofacial morphology on bite force has been studied by cephalometric studies. it has been demonstrated that bite force in individuals with normal face height is higher than in long face individuals and lower than in short face individuals (5-7). (1)lecturer. department of orthodontics. college of dentistry. university of baghdad. the maximum bite force also varies with skeletal craniofacial morphology, decreasing with increasing vertical facial relationships, the ratio between anterior and posterior facial height, mandibular inclination, and gonial angle (8-10). in transverse dimensions, anthropometric measurements of the face show a direct relationship between bite force and transverse facial dimensions (11). the bite force in adult women was lower than in adult men. for woman, force increased with age until 25 years and then decreased. in men, it also increased until 25 years except the level remained unchanged until 45 years and then tended to decrease (2). the effect of age on bite force in adults is likely to be due to the age-dependent deterioration of the dentition rather than to a reduction in muscular force (12,13). on the other hand, the malocclusions are often associated with reduced maximum bite force (1416), therefore, orthodontic treatment may be needed to improve function (14). al-sam (17) compared the bite force of different facial heights for normal occlusion in an iraqi adult sample. he found a highly significant difference between males and females. also, the maximum bite force in normal occlusion was higher than class i malocclusion. the maximum bite force in iraqi children was higher in children with full contact of teeth than in children with partial contact of teeth. the difference was statistically insignificant. a clear correlation existed between maximum bite force and the angulations of the mandibular incisors (18). j bagh college dentistry vol. 25(3), september 2013 the relationship among pedodontics, orthodontics and preventive dentistry116 al-saadi (19) measured and compared maximum bite force among different classes of malocclusion, he found that class iii malocclusion had highest value of the maximum bite force followed by class ii malocclusion then class i malocclusion. al-qazzaz (20) found that thicker masseter muscles which relate to larger bite force values was usually associated with short faced subjects when compared with normal or long faced subject. kadhim (21) investigated the relationship of the occlusal bite force with handedness and facial asymmetry in iraqi arab adult sample. he found that bite force was independent of handedness. males have significantly greater molar bite force than females. hasson (22) conducted a study to measure and compare maximum bite force, body height and weight among normal occlusion and malocclusion groups (cl i, cl ii, cl iii) in both genders and to evaluate the correlation between bite force and craniofacial morphology, body height and weight. she found that normal occlusion group had larger values of bite force than malocclusion groups, the maximum bite force, body height were genders related, larger body build up was usually associated with larger bite force in class i skeletal relationship. individuals with characteristics of larger maxilla, larger mandible, larger cranial base, short anterior facial height long posterior facial height, flat mandibular plane had the largest value of bite force. this study aimed to determine whether there is a relationship among the bite force with facial dimensions and dental arches in a sample of iraqi adults with class i skeletal and dental relations. materials and methods sample the sample included 40 dental students of the college of dentistry, university of baghdad (20 males and 20 females) with an age ranged from 20-23 years. all of them had full set of normal permanent teeth in both jaws regardless the third molars also had class i skeletal and dental relationship as described by foster (23) and had no history of tmj problem like clicking or crepitus, tenderness, muscle or jaw pain or discomfort during mandibular movements when talking or eating. on the other hand, they had no history of previous orthodontic treatment and/or orthognathic surgery and had no massive carious lesions and filling restorations or congenital defect or deformed teeth or facial asymmetry and/or cross bite. methods history and clinical examination each subject is asked to seat comfortably on the dental chair and asked information about the name, age, origin, medical history, the history of facial trauma and orthodontic treatment. then they were asked to look forward horizontally (frankfort plane parallel to the floor) for clinical examination, extra-orally and intra-orally to check their fulfillment of the required sample selection. dental cast production and analysis impressions were taken for every subject with alginate impression material then poured with a prepared amount of stone. after setting of the dental stone, a base of plaster of paris was prepared, and then the poured cast was inverted over it. after the final setting of the gypsum, the base was trimmed uniformly by trimmer and made ready for the measuring procedure. after taking the proper impression for the maxillary and mandibular arches and preparing the casts, a photograph was taking to each dental cast using an apparatus designed by saadi (24). then the photographs were imported to the autocad program 2007 to determine the points and measure the maxillary and mandibular arches widths at canine and 1st molar area after magnification correction. the inter-canine distance (icd) is the linear distance from cusp tip of one canine to the cusp tip of the other (25), while the inter first molar distance (imd) is the linear distance from the mesio-buccal cusp tip of one first permanent molar, to the mesio-buccal cusp tip of the other (26). facial photographs production and analysis the digital camera (sony cyber shot h 50, 9.1 mega pixels, 15 x optical zoom, sony corporation, nagoya, japan) was fixed in position and adjusted in height to be at the level of subject 'eyes in the frontal photograph with a height adjustable tripod. the distance from the camera to the subject was fixed at a distance of about 1.01m measured from the tripod’s column to the ear rods that were fit in the external auditory meatus in order to avoid the forward, backward, and tilting of the subject head (cephalostate based head position). the subject was asked to look to the center of the lens of the camera in the frontal photograph and to look at a distant mirror which is placed in front of his/her face in the lateral photograph with ear rods in the external auditory meatus (27). facial dimensions were measured using autocad program 2007 after the correction of j bagh college dentistry vol. 25(3), september 2013 the relationship among pedodontics, orthodontics and preventive dentistry117 the magnification. interzygomatic distance (izd) or the facial width is the transverse distance between soft tissue zygion on both sides (28) (zygoin or zyg is the most prominent point on the cheek area beneath the outer canthus and slightly medial the vertical line passing through it; different from bony zygoin) (29). while the anterior facial height (n-gn) of the facial height is the distance between soft tissue nasion and soft tissue gnathion (25) (nasion or n is the point in the midline of both the nasal root and the nasofrontal suture, always above the line that connects the two inner canthi, identical to bone nasion (29) and gnathion or gn is the soft tissue point corresponding to skeletal gnathion (30) which is the most anterior and inferior point of the soft tissue chin (31). measuring the bite force the device (gm10; naganokeiki company, tokyo, japan) consisted of hydraulic pressure gauge and a biting element made of a vinyl material encased in a plastic tube called disposable occlusal cap that will be replaced for each subject. the accuracy of this occlusal force gauge has been previously confirmed (32). the specifications of this device are: aforce range: 0 – 1000 n. baccuracy: ±1 n. cweight: about 70 g. dsize: 195 (l) x 29 (w) x 18(h) mm. the maximum bite force was recorded in the first molars (bilaterally) and incisors region by putting the sensor part of the device on the first molar region and the participant was asked to bite firmly for a few seconds as much as he/she can, then the bite force was calculated in newton and displayed digitally. this bite measurement was repeated three times for each side and region in alternating order with 2-3 minutes interval between records, and the highest value was registered for each side or region. statistical analyses all the data of the sample were subjected to computerized statistical analysis using spss version 19 computer program. the statistical analyses included: 1. descriptive statistics: means, standard deviations (sd), standard errors and statistical tables. 2. inferential statistics: independentsamples ttest for the comparison between both genders and pearson’s correlation coefficient (r) to determine the relationship among the bite force with the facial dimensions and dental arches widths. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results and discussion descriptive statistics and genders difference were presented in table 1. regarding the bite force, generally the males possessed higher bite force than females in incisors and molars areas with a non-significant genders difference. the reason behind this was due to the excretion of ketosteroids in post pubertal young men which lead to increase of muscle mass (33). androgens are hormones that exert musculinizing effects and they promote protein anabolism and growth. secretion of adrenal androgens is controlled by acth (adrenocorticotrophic hormone) and possibly by a pituitary adrenal androgen stimulating hormone. the major adrenal androgen is 17-ketosteriod; this hormone formed by cortisol and cortisone by side chain cleavage in the liver. testosterone is also converted into a 17 ketosteroid. the daily 17-ketosteroid excretion in normal adults is 15 mg in male and 10 mg in female (34). waltimo and kononen (35) reported significant differences in the maximum bite force between genders only for the molar region, which can probably be explained by the fact that the bite force on the incisal area could be limited by the periodontal ligament sensitivity and not by the muscle strength as in the posterior area of the mouth. abu alhaija et al. (5) and raadsheer et al. (11) could not find differences between genders. on the other hand, the masseter muscles of males have type 2 fibers with larger diameter and greater cross-sectional area than those of the females which may result in higher occlusal forces (35,3638). generally, the males had wider and longer face than females with a highly significant difference. the findings of this study support the conclusions of bishara et al. (39) who noticed that in normal populations, males have larger skeletal, cranial, facial and dental arch dimensions than females. regarding the dental arches widths, the maxillary and mandibular inter-canine and inter1st molar distance were larger in males than females, this may be explained by: 1. the smaller and smoother bony ridge and alveolar process of females (40). j bagh college dentistry vol. 25(3), september 2013 the relationship among pedodontics, orthodontics and preventive dentistry118 2. the average weakness of musculature in females that play an important role in facial breadth measurements, width and height of dental arch (40). 3. longer growth period for males than females (41,42). table 1. descriptive statistics and genders difference for the measured variables variables genders descriptive statistics genders differences (d.f.=38) mean s.d. s.e. t-test p-value right posterior bite force males 378.67 189.66 48.97 0.24 0.814 (ns) females 363.13 167.20 43.17 total 370.90 175.85 32.11 left posterior bite force males 404.60 186.51 48.16 0.33 0.747 (ns) females 380.33 220.27 56.87 total 392.47 200.92 36.68 average posterior bite force males 391.63 181.95 46.98 0.30 0.769 (ns) females 371.73 185.19 47.82 total 381.68 180.67 32.99 anterior bite force males 121.93 46.70 12.06 1.49 0.147 (ns) females 97.87 41.47 10.71 total 109.90 45.09 8.23 facial width males 142.98 6.19 1.60 2.93 0.007 (hs) females 136.67 5.60 1.45 total 139.83 6.63 1.21 facial height males 138.70 5.82 1.50 5.79 0.000 (hs) females 125.22 6.88 1.78 total 131.96 9.28 1.69 upper inter canine distance (uicd) males 26.63 0.31 0.08 0.71 0.485 (ns) females 26.34 1.52 0.39 total 26.48 1.09 0.20 upper inter 1st molar distance (uimd) males 52.34 2.71 0.70 8.80 0.000 (hs) females 44.31 2.27 0.58 total 48.33 4.76 0.87 lower inter canine distance (licd) males 34.29 1.67 0.43 12.01 0.000 (hs) females 27.01 1.65 0.43 total 30.65 4.04 0.74 lower inter 1st molar distance (limd) males 51.71 2.25 0.58 6.94 0.000 (hs) females 45.47 2.66 0.69 total 48.59 3.99 0.73 table 2 showed the relation among the measured parameters with the bite force. the results indicated that there was no significant relation; that means neither the dental arch widths nor the facial height or width had influence on the bite force both anteriorly and posteriorly. duygu et al. (43) found that total anterior facial height showed no correlation with bite force in both genders. raadsheer et al. (11) reported that there was a positive relationship between transverse facial dimensions and bite force in adults. the difference between the present study and the others may be attributed to the sample size or selection as the difference in facial height and widths might have a direct effect. references 1. daskalogiannakis j. glossary of orthodontic terms. 1st ed. germany: quintessence publishing co.; 2000. 2. bakke m, holm b, jensen bl, michler l, moller e. unilateral, isometric bite force in 8-68 years old women and men related to occlusal factors. scand j dent res 1990; 98: 149-58. 3. bakke m, michler l, han k, möller e. clinical significance of isometric bite force versus electrical activity in temporal and masseter muscles. scand j dent res 1989; 97(6): 539-51. 4. ferrario vf, sforza c, serrao g, dellavia c, tartaglia gm. single tooth bite forces in healthy young adults. j oral rehabil 2004; 31: 18-22. 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(ivsl). j bagh college dentistry vol. 25(3), september 2013 the relationship among pedodontics, orthodontics and preventive dentistry119 6. koc d, dogan a, bek b. bite force and influential factors on bite force measurements: a literature review. eur j dent 2010; 4(2): 223-32. 7. custodio w, gomes sg, faot f, garcia rc, del bel cury aa. occlusal force, electromyographic activity of masticatory muscles and mandibular flexure of subjects with different facial types. j appl oral sci 2011; 19(4): 343-9. 8. ingervall b, helkimo e. masticatory muscle force and facial morphology in man. arch oral biol 1978; 23: 203-6. 9. throckmorton gs, buschang bh, hayasaki h, phelan t. the effects of chewing rates on mandibular kinematics. j oral rehabil 2001; 28: 328–34. table 2. correlation among bite force with facial dimensions and dental arches widths in males, females and total sample variables genders facial width facial height uicd uimd licd limd right posterior bite force males r 0.368 0.176 0.048 -0.068 -0.422 -0.199 p 0.177 (ns) 0.532 (ns) 0.866 (ns) 0.809 (ns) 0.117 (ns) 0.477 (ns) females r -0.225 -0.018 -0.328 -0.144 -0.073 0.026 p 0.421 (ns) 0.948 (ns) 0.232 (ns) 0.608 (ns) 0.795 (ns) 0.925 (ns) total r 0.114 0.084 -0.197 -0.013 -0.144 -0.098 p 0.550 (ns) 0.658 (ns) 0.296 (ns) 0.945 (ns) 0.446 (ns) 0.607 (ns) left posterior bite force males r 0.443 0.230 0.032 -0.198 -0.378 -0.186 p 0.098 (ns) 0.409 (ns) 0.909 (ns) 0.480 (ns) 0.165 (ns) 0.506 (ns) females r -0.245 -0.036 -0.196 0.084 -0.034 0.045 p 0.379 (ns) 0.899 (ns) 0.485 (ns) 0.767 (ns) 0.904 (ns) 0.873 (ns) total r 0.106 0.096 -0.132 0.023 -0.133 -0.091 p 0.578 (ns) 0.614 (ns) 0.486 (ns) 0.903 (ns) 0.485 (ns) 0.633 (ns) average posterior bite force males r 0.419 0.209 0.041 -0.137 -0.414 -0.199 p 0.120 (ns) 0.454 (ns) 0.883 (ns) 0.626 (ns) 0.125 (ns) 0.476 (ns) females r -0.247 -0.030 -0.264 -0.015 -0.053 0.039 p 0.375 (ns) 0.916 (ns) 0.341 (ns) 0.957 (ns) 0.850 (ns) 0.891 (ns) total r 0.114 0.094 -0.170 0.006 -0.144 -0.098 p 0.548 (ns) 0.620 (ns) 0.370 (ns) 0.973 (ns) 0.448 (ns) 0.606 (ns) anterior bite force males r -0.239 -0.037 -0.167 0.157 -0.139 0.292 p 0.390 (ns) 0.897 (ns) 0.552 (ns) 0.576 (ns) 0.621 (ns) 0.292 (ns) females r -0.231 -0.135 0.045 -0.145 -0.012 0.017 p 0.407 (ns) 0.633 (ns) 0.873 (ns) 0.605 (ns) 0.966 (ns) 0.953 (ns) total r -0.067 0.145 0.040 0.247 -0.279 -0.115 p 0.724 (ns) 0.446 (ns) 0.834 (ns) 0.189 (ns) 0.136 (ns) 0.546 (ns) 10. sondang p, kumagai h, tanaka e, ozaki h, nikawa h, tanne k. correlation between maximum bite force and craniofacial morphology of young adults in indonesia. j oral rehabil 2003; 30:1109-17. 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19(3): 274-9. abdulkareem.doc j bagh college dentistry vol. 27(2), june 2015 the antibacterial restorative dentistry 1 the antibacterial effect of herbal alternative, green tea and salvadora persica (siwak) extracts on entercoccus faecalis abdulkareem j. al-azzawi, b.d.s., m.sc. (1) abstract background: disinfection and shaping of the canal with a combination of chemical agents and endodontic instruments play an important role in the success of endodontic therapy. eliminating the microorganisms within the pulp space is a critical and important objective in treating a tooth with apical periodontitis. this study was conducted to evaluate the antibacterial properties of herbal alternatives (green tea and siwak extracts) as possible irrigants during endodontic treatment compared with the conventional irrigation solutions. materials and methods: salvadora persica (siwak) and green tea solutions were prepared.an agar diffusion test was performed on mueller-hinton agar using the well diffusion method. the tested solutions (5.25% naocl, 2% chlorhexidine gluconate, 5% siwak extract and 5% green tea extract)were used to fill the wells that were made in the agar media respectively.plates were left to incubate for 24 hr. at 37°c. zones of inhibition of the bacterial growth were calculated to measure the antibacterial effect of the tested irrigants. results: sodium hypochlorite had the highest mean value (29.88) followed by chlorhexidine which had a mean value of (26.13), siwak with mean value of (11.25) and green tea being the least with mean value of (8.88). anova test showed a highly statistical difference with a p-value of (0.000). conclusions: naocl still the superior irrigant than other irrigants. herbal alternatives (siwak and green tea) can be used as possible irrigants solution to disinfect the root canal system from enterococcus faecalis during endodontic treatments. key words: green tea, siwak, enterococcus faecalis. (j bagh coll dentistry 2015; 27(2):1-5). introduction cleaning of the root canal system, as well as proper filling of the canal, are essential procedures for the success of root canal treatment. even when treatment is adequate, failure may occur within the canal.therefore, disinfection and shaping of the canal with a combination of chemical agents and endodontic instruments play an important role in the success of endodontic therapy, (1,2). eliminating the microorganisms within the pulp space is a critical and important objective in treating a tooth with apical periodontitis. studies have shown that recurrent root canal infections can occur even after endodontic treatment and are most commonly associated with enterococcus faecalis (3-5). sodium hypochlorite has been used as the irrigant of choice for endodontic procedures, but it has many deleterious effects if pushed beyond the apex. chlorhexidine gluconate is another commonly used disinfectant. but its activity is ph dependent and it is toxic to human periodontal ligament cells (2). herbal products have been used in dental and medical practice for thousands of years and now become more popular due to their antimicrobial activity, biocompatibility, anti-inflammatory and anti-oxidant properties (6). (1)professor, department of conservative dentistry, college of dentistry, university of baghdad. tea is the second most commonly drank liquid on earth after water. it is known to possess anticariogenic and antibacterial properties.green tea has antimicrobial activity which is due to inhibition of bacterial enzyme gyrase by binding to atp b sub unit. green tea exhibits antibacterial activity on enterococcus facealis. it is also found to be a good chelating agent (7,8). salvadora persica, commonly known as siwak, was used as a chewing stick. extracts of salvadora persica has been shown to contain trimethylamine, salvadorine, chloride, fluoride, and traces of tannins, saponins, flavonoids and sterol. these components have been shown to have significant antibacterial (9,10). this study was concluded to evaluate the antibacterial properties of herbal alternatives (green tea and siwak extracts) as possible irrigants during endodontic treatment compared with the conventional irrigation solutions. materials and methods salvadora persica (siwak) preparation sticks of siwak (s. persica) were incubated at 37 c for 24 hrs. each stick was cut with a knife to small pieces then ground into fine powder, 250 gm of s. persica powder was put in a beaker to which one litter of sterile distilled water was added. the liquid was boiled at 100 c for 15 minutes in a closed container. after bench cooling, the liquid was filtered using filter paper j bagh college dentistry vol. 27(2), june 2015 the antibacterial restorative dentistry 2 (no.1), and solution left to dry in an incubator at 37 c for 24 hours to allow complete evaporation of water and obtain powder of siwak. the powder was collected and kept in tightly closed glass container and kept in refrigerator until use (11). green tea preparation five gram of the selected dry green teas leaf, steeped for 1.52 minutes in 100 ml of distilled water. the coolest brewing temperature was below 70˚c.the mixture was purified to obtain the 5% concentration solution of green tea (12). sample grouping group a: 5.25% naocl irrigant was used to fill the wells that were made in the agar media. group b: 2% chlorhexidine gluconate irrigant solution was used to fill the wells that were made in the agar media. group c: 5% siwak extract irrigant solution was used to fill the wells that were made in the agar media. group d: 5% green tea extract irrigant solution was used to fill the wells that were made in the agar media. test microorganism and growth conditions antibacterial activities of the irrigants were evaluated against the enterococcus faecalis. an agar diffusion test was performed on muellerhinton agar using the well diffusion method. mueller-hinton agar was freshly prepared after which, the surface was inoculated with 0.1 ml. of brain heart infusion (bhi) broth culture of enterococcus faecalis. a well was punched in the agar in the center of each petri dish and the tested materials were added to these wells. plates were left to incubate for 24 hr. at 37°c. zones of inhibition of the bacterial growth were calculated to measure the antibacterial effect of the tested irrigants. results the results obtained from this study were as follow (table 1). table 1: bacterial inhibition zone in mm. using 5.25% sodium hypochlorite, 2% chlorhexidine gluconate, 5% siwak extract and 5% green tea extract. samples naocl bacterial inhibition mm chlorhexidine bacterial inhibition mm siwak bacterial inhibition mm green tea bacterial inhibition mm 1 30 25 12 9 2 32 23 11 9 3 35 27 10 8 4 26 25 13 10 5 33 25 13 8 6 24 26 11 9 7 29 28 10 10 8 30 30 10 8 statistical analyses of the obtained results were performed using spss program version 19. the mean values and standard deviation of the tested irrigants were shown in table 2 and figure 1. table 2: descriptive statistics groups mean ±s.d. min. max. a 29.88 3.60 24 35 b 26.13 2.17 23 30 c 11.25 1.28 10 13 d 8.88 0.83 8 10 j bagh college dentistry vol. 27(2), june 2015 the antibacterial restorative dentistry 3 figure 1: bacterial inhibition in mm. from table 2, sodium hypochlorite had the highest mean value (29.88) followed by chlorhexidine which had a mean value of (26.13), siwak with mean value of (11.25) and green tea being the least with mean value of (8.88). groups’ comparison between the four groups and within the groups were made by using anova test which showed as highly statistical difference with a p-value of (0.000) as shown in table 3. table 3: groups’ comparison by anova test sum of squares d.f. mean square f-test p-value between groups 2652.84 3 884.28 176.69 0.000 (hs) within groups 140.13 28 5.00 total 2792.97 31 lsd test was performed to compare among the mean difference between each paired groups, all showed highly significant p-value except between group c and d which only showed significant difference with p-value of (0.043) as shown in table 4 table 4: lsd test groups mean difference p-value a b 3.75 0.002 (hs) c 18.63 0.000 (hs) d 21.00 0.000 (hs) b c 14.88 0.000 (hs) d 17.25 0.000 (hs) c d 2.38 0.043 (s) discussion the irrigant solutions are very important during the root canal preparation, because they aid in the cleaning of root canal, lubricate the files, flush out debris, and have an antimicrobial effect and tissue dissolution, without damaging the periapical tissues. the microorganism tested in this study is a part of the endodontic microbial flora. naocl solution is, to date, the most commonly employed root canal irrigant, but no general agreement exist regarding its optimal concentration, which ranges from 0.5% to 5.25% (13). in the present study, 5.25% naocl was effective to considerably reduce enterococcus faecalis creating the largest inhibition zones of bacterial growth in the agar media. this result was in agreement with several studies (14,15). chlorhexidine gluconate has been recommended as an alternative irrigating solution to naocl. the antimicrobial effect of chlorhexidine gluconate is related to the cationic molecule binding to negatively charged bacterial j bagh college dentistry vol. 27(2), june 2015 the antibacterial restorative dentistry 4 cell walls, thereby altering bacterial osmotic equilibrium (16). within the results of the present study regarding the inhibition of enterococcus faecalis by chlorhexidine gluconate which was found to be effective but less than the inhibition effect of naocl. these results were in agreements with the results obtained by many studies, as murad et al. found that most effective irrigants in eliminating e. faecalis biofilms were 2.5% and 5.25% naocl and the chlorhexidine liquid and mtad were less effective than 2.5% and 5.25% naocl. (17), spratt et al. and dunavant et al., reported that different concentrations of naocl (varying from 1% to 6%) were more effective than 0.2% chlorhexidine and 2% chlorhexidine and mtad in the elimination of e. faecalis biofilms (23,24). salvadora persica (miswak-siwak), its chewing sticks contain trimethyl amine, salvadorime chloride and fluoride in large amounts (18), showed some antimicrobial activity which make it possible to be used as irrigant solution in endodontic treatment against the endodontic pathogens, it can be used as a substitute for sodium hypochlorite and chlorhexidine as root canal irrigant (19,20). green tea is a traditional drink of japan and china and is prepared from the young shoots of tea plant camellia sinensis (8). the leaves from the tea plant contain polyphenolic components with activity against a wide spectrum of microbes (21). in the present study 5% green tea extract was used to evaluate its effectiveness against enterococcus faecalis, it obtained a mean of 8.88 which was the least of the tested groups. this finding indicates that it is less effective than naocl, chx and miswak. the results of the this study were similar to another studiesas prabhakar et al. concluded that 5% sodium hypochlorite showed maximum antibacterial efficacy against enteroccus faecalis biofilm while triphala, green tea polyphenol and mtad showed statistically significant antibacterial activity (8) anurag et al. concluded that although conventional irrigants are more frequently used, have shortcomings in antibacterial efficacy. it was concluded that neem leaf and green tea extract has a significant antimicrobial effect against e. faecalis. as the american medical association shows that green tea has excellent medicinal values. it is also observed that green tea has antibacterial effect against enterococcus faecalis. green tea polyphenols antioxidant potential is directly related to the combination of aromatic rings and hydroxyl groups that make up their structure, and is a result of binding and neutralization of free radicals by the hydroxyl groups leading to destruction and dissolution of bacterial cell wall (22). as conclusion; naocl still the superior irrigant than other irrigants. herbal alternatives (siwak and green tea) can be used as possible irrigants solution to disinfect the root canal system from enterococcus faecalis during endodontic treatments. references 1. nair pn, sjögren u, krey g, et al. intra-radicular bacteria and fungi in root-filled, asymptomatic human teeth with therapy-resistant periapical lesions: a long-term light and electron microscopic follow-up study. j endod 1990; 16(12): 580-8. 2. medici mc, froner ic. a scanning electron microscopic evaluation of different root canal irrigation regimes. braz oral res. 2006; 20(3): 23540. 3. möller aj, fabricius l, dahlén g, et al. influence on periapical tissues of indigenous oral bacteria and necrotic pulp tissue in monkeys. scand j dent res 1981; 89: 475-84. 4. sedgley cm, molander a, flannagan se, et al. virulence, phenotype, genotype characteristics of endodontic enterococcus spp. oral microbiol immunol 2005; 20:10-9. 5. siqueira jf jr, rôcas in. polymerase chain reactionbased analysis of microorganisms associated with failed endodontic treatment. oral surg oral med oral pathol oral radiol endod 2004; 97: 85-94. 6. dilsah c, atac u, kadriye s, et al. efficacy of propolis as an intracanal medicament against enterococcus faecalisgen dent 2006; 54: 319-22. 7. gradišar e. green tea catechins inhibit bacterial dna gyrase by interaction with its atp binding site. 2007: http:// pubs.acs.org/doi/abs/10.1021/jm060817o 8. prabhakar j, senthilkumar m, priya m s, et al. evaluation of antimicrobial efficacy of herbal alternatives (triphala and green tea polyphenols), mtad and 5% sodium hypochloride against enterococcus faecalis biofilm formed on tooth substrate: an in vitro study. j endod 2010: 36: 83-6. 9. hattab fn. miswak: the natural toothbrush. j clin dent 1997; 8: 125-9. 10. elvin-lewis m. the therapeutic potential of plants used in dental folk medicine. odontostomatol trop 1982; 5: 107-17. 11. al-nidawi aa. effect of siwak extracts on mutans streptococci, in comparison to selected antimicrobial agents (in vitro and in vivo study). a master thesis, department of preventive dentistry, college of dentistry, university of baghdad, 2004. 12. avwioro g, lyiola s, aghoghovwia b. histological and biochemical markers of the liver of wistar rats on subchronic oral administration of green tea. north am j medical sci 2010; 2(8): 376-80. 13. goldman m, goldman lb, kronman jh, et al. the efficacy of several irrigating solutions for endodontics: a scanning electron microscopic study. oral surg 1981; 52:197-204. j bagh college dentistry vol. 27(2), june 2015 the antibacterial restorative dentistry 5 14. gomes bp, ferraz cc, vianna me. in vitroantimicrobial activity of several concentrations of sodium hypochlorite and chlorhexidine gluconate in the elimination of enterococcus faecalis. int endod j 2001 34: 424-428. 15. berber vb, gomes bp, sena nt, et al. efficacy of various concentrations of naocl and instrumentation techniques in reducing enterococcus faecalis within root canals and dentinal tubules. int endod j 2006 39:10-17. 16. greenstein g, berman c, jaffin r. chlorhexidine: an adjunct to periodontal therapy. j periodontol 1986; 57: 370-7. 17. murad cf, sassone lm, souza mc, fidel ras, fidel sr, junior rh. antimicrobial activity of sodium hypochlorite, chlorhexidine and mtad® against enterococcus faecalis biofilm on human dentin matrix in vitro. rsbo. 2012; 9(2):143-50 18. almas k. the antimicrobial effects of extracts of azadirachtaindica (neem) and salvadora persica (arak) chewing sticks. indian j dent res 1999: 10: 23-26. 19. al-subawi nak, abdull-khalik k, mahmud y, taha my, et al. the antimicrobial activity ion of salvadora persica solution (miswak –siwak) as root canal irrigant. university of sharjah j pure & applied sci 2007:4: 69-91. 20. almas k. the effect of salvadora persica extracts (miswak) and chlorhexidine gluconate on human dentin: a sem study. j contemp dent pract 2002: 3: 27–35. 21. taylor pw, jeremy mt, hamiltonmiller, et al. antimicrobial properties of green tea catechins. food sci technol bull 2005; 2: 71-81. 22. anurag s, anuraag g, chandrawati g. comparison of antimicrobial efficacy of conventional irrigants and herbal products alone and with calcium hydroxide against enterococcus faecalis. guident 2012; 5(2): 77. 23. dunavant tr, regan jd, glickman gn, et al. comparative evaluation of endodontic irrigants against enterococcus faecalis biofilms. j endod 2006; 32: 527-31. 24. spratt da, pratten j, wilson m, et al. an in vitro evaluation of the antimicrobial efficacy of irrigants on biofilms of root canal isolates. int endod j 2001; 34: 300-7. balqees f.doc j bagh college dentistry vol. 28(2), june 2016 an extrafollicular cystic oral diagnosis 47 an extrafollicular cystic adenomatoid odontogenic tumor of the mandible associated with clear cell calcifying epithelial odontogenic tumor: a rare case report balkees taha garib, b.d.s., m.sc., ph.d. (1) ibrahim saeed gataa, f.i.c.m.s. (2) dena nadhim mohammad, ph.d. (3) noroz hama rashid, b.d.s. (4) abstract background: the adenomatoid odontogenic tumor is a relatively rare benign epithelial odontogenic tumor. it contains both epithelial and mesenchymal components. few cases presented as an extrafollicular lesion or involve the mandible or associated with other odontogenic lesions. this paper represents a rare case of an extrafollicular aot. case presentation: a 24-year-old female had a painless swelling on the right side of the lower jaw since one-month duration. intraorally there was a well defined fluctuant-blue swelling in the right alveolar premolar region measuring 1×2 cm obliterating the right lower buccal vestibule. grade ii mobility in the vital 44 and 45 teeth were observed. panoramic radiographs showed a well-defined pear shaped radiolucent lesion without calcifications between the roots of 44 and 45 that cause roots divergence. the lesion totally enucleated with the tooth 44 which showed root resorption. microscopically, a cystic lesion lined by simple odontogenic epithelial cells with areas of polygonal nodular proliferation (sheets, whorled masses with few duct-like structures and clear cells) and amorphous eosinophilic material. this material was pas –negative, and congo red positive. the case diagnosed as a cystic extrafollicular variant of aot with ceot-like areas. conclusions this case report describes the first known case of extrafollicular combined aot/ceot associated with root resorption and clear cells. the existence of clear cells suggest a possible aggressive nature and long follow up recommended. keywords: adenomatoid odontogenic tumor, calcifying epithelial odontogenic tumor, clear cells, mandible. (j bagh coll dentistry 2016; 28(2):47-51). introduction adenomatoid odontogenic tumor (aot) is a relatively rare epithelial odontogenic tumor (1). it is regarded either as a true benign, non-aggressive non-invasive tumor or as a developmental hamartomatous odontogenic growth. it is believed that the lesion is not a neoplasm. the world health organization (who) defined aot as “a tumor of odontogenic epithelium with duct-like structures and with varying degrees of inductive changes in the connective tissue. the tumor may be partly cystic, or contain solid masses in the wall of a large cyst (1). its icd-o code is 9300/0. according to the biologic classification, aot is a benign tumor with no recurrence potential (2). aot is more frequently reported in females, and less commonly involve the mandible (3,4). a percentage of 26.9 of aot cases may present as an extrafollicular lesion with m: f ratio of (close to) 1:2 (3). it may locate between, above or superimpose roots of erupted teeth (5). histologically, aot has diverse features (6,7). (1)professor. department of oral pathology, school of dentistry, faculty of medical sciences, university of sulaimani. (2)assistant professor. department of oral surgery, school of dentistry, faculty of medical sciences, university of sulaimani. (3)lecturer. department of oral pathology, school of dentistry, faculty of medical sciences, university of sulaimani. (4)oral and maxillofacial surgery 4th year board trainee, teaching hospital, ministry of health. the literature review remarked for the association of aot cases with another odontogenic lesion (8,9). several investigators have pointed out the presence of ceot-like tissue in aot (10-13) and believed to be a frequent finding (14). there is still a need to continue reporting welldocumented cases of the extrafollicular variant. concerning the exact location especially when they seem to have unusual or rare’ histomorphological features, or in a new ethnic group or geographical region and relate these findings to the biological behavior of aots and possibility of tumor recurrence. case report a 24-year-old female attended the maxillofacial center in the teaching hospital in sulaimani on 22/4/2013 with a chief complaint of a painless swelling on the right side of the lower jaw since one-month duration. the patient was clinically healthy, and all her vital signs were within normal limits. on clinical examination, there was a well-localized swelling in the right alveolar premolar region measuring 1×2 cm obliterating the right lower buccal vestibule. grade ii mobility in 44 and 45 were observed. the swelling was fluctuant, and the overlying j bagh college dentistry vol. 28(2), june 2016 an extrafollicular cystic oral diagnosis 48 mucosa was blue in color. neither the teeth nor the swelling was tender, and there was no palpable lymph node in the submandibular region. electric pulp test indicated vital teeth. the patient subjected to radiological examination for the lesion. a panoramic radiograph view showed a well-demarcated pear shaped radiolucent lesion involve the right side alveolus between the roots of 44 and 45and cause roots divergence. the root of 44 showed resorption (figure-1c). fna revealed a thin clear fluid. excisional biopsy of the mass along with the tooth 44 was done (figure 1b). there were no apparent infiltrations of the surrounding bone. the surgical sample sent for histopathological examination. grossly, the specimen consisted of a cystic lesion attached to the lateral surface of the tooth 44, with brownish wall and it contained thin clear fluid. the specimen measured approximately 1 x0.5 x2 cm in dimension. two general histopathologists from two centers assessed the slides. the results were dissimilar. in the first report, the case was diagnosed as ceot while the second indicated mucoepidermoid carcinoma. therefore, a third opinion was suggested to be done by an oral pathologist. a b c figure1: extirpated tumor completely encased the tooth (a). the cyst bag adhered laterally to the lower first premolar’s root (b). panoramic radiograph before therapy. a well-demarcated unicystic radiolucent lesion in the lower right side jaw between the roots of the teeth 44 and 45 results in root divergence, and adjacent tooth 44 showed resorption of the root (c). histopathologically, the cyst lined by thin odontogenic epithelium cells that surround a loose fibrovascular stroma. the epithelial cells extend shortly as strands intramurally or show thinking with hyalinization or continued with lace-like and nodular proliferation (figure 2). the proliferating cells revealed: few duct-like structures, polyhedral cells that had a clear or sometimes intensely eosinophilic cytoplasm, with nuclear hyperchromatism and a mild degree of variability in nuclear size (pleomorphism) in a scant connective tissue stroma. in the intercellular and intraductal sites, there are amorphous eosinophilic materials. the cystic wall is thick connective tissue capsule exhibiting bundles of loosely arranged collagen bundles with fibroblasts, blood vessels and areas of hemorrhage. therefore, the case suggested containing clear cell variant of ceot. then the slides subjected for congo red and pas stains to identify amyloid and confirm the diagnosis. the material stained positively with congo red and negatively with pas. the final diagnosis was a cystic variant of extrafollicular types aot with ceot-like areas the patient was followed-up for two year and six months without any evidence of recurrence (figure -3). then inform consent was obtained from the patients to publish the work. the paper was approved by the ethics committee in the medical faculty. discussion the present report recorded the first case of extrafollicular combined aot/ceot in an iraqikurdish female patient. the case showed distinctive clinical and histological features. comparing the clinical and radiological features of our case with aot and combined aot/ceot cases described in the literature indicate that the sex and the age of the patient are similar. the patient’s age fit with the peak incidence of aot tumor (the second decade of life). nevertheless, patients with extrafollicular aot have been reported to be significantly in older age than those with the follicular variant (3). philipsen and coauthors (4) conducted a collaborative retrospective study that included 1082 aot cases from 12 major centers in the world. they collected the data up to the end of 2005 and showed that 26.7% (9% male, 17.9% female) of aot were the extrafollicular type with slight maxillary predominance 15.5% in comparison to mandible 11.2% (4). on the other hand, becker et al. (3) also find that extrafollicular variant aot constituted 27%. however, they j bagh college dentistry vol. 28(2), june 2016 an extrafollicular cystic oral diagnosis 49 reported opposing localization. they found (12%) of cases in the maxilla and (15%) of cases in the mandible. concerning the reported combined aot/ceot cases, siar and ng indicated that such cases had a predilection for the mandible (55.6%) (15).the literature indicated that the reported combined aot/ceot lesions were predominantly follicular (11,13,16). figure 2: histopathologically the cyst lined by thin odontogenic cells that surround a fibrovascular stroma (a). the epithelial cells extend as strands intramurally or show thinking with hyalinization (b &c), beside an area of nodular proliferation (d arrow). the proliferating cells revealed: few duct-like structures (e), polygonal clear cells with nuclear hyperchromatism (f) and polymorphism (g), and foci intercellular and intraductal eosinophilic material (h). the amorphous material is amyloid. after staining withcongo red it appears bright orange under fluorescent light (i).(a and d, x10; remaining photomicrographs x40) figure 3: panoramic radiograph of the patient 54 months after treatments in contrast, the extrafollicular aot cases showed histologically classic aot feature (17-19) and involved the lower jaw. the present case and that of wilia (18) are in the canine-premolar region while yilmaz case (19) located in the mandibular anterior region. however, the current case differ from them in type. it is an extrafollicular combined aot/ceot lesion. aot is a slowly growing tumor and when detectable at the small size described as a localized swelling of the involved jaw. it has been indicated that the size of an aot influenced by the patient’s age (3). our patient was 24 years old, her lesion is 1x2 cm and become evident within one month only. the unexpected short disease duration is unlike the documented clinical registered period in the literature which was mostly between 6-12months disease duration, even in young aged patients (9,10,17). according to the radiographical findings, extrafollicular aot has several topographical relation to the teeth. herein, the case is categorized as e2 type; it indicates an interradicular localized tumor with extensive growth a b c d e f g h i j bagh college dentistry vol. 28(2), june 2016 an extrafollicular cystic oral diagnosis 50 causing divergence of roots (5). however, our case associated with root resorption. irregular root resorption is rarely seen with intraosseous aot. identification of radiological root resorption was related to a longer disease duration and to be associated with patients aged 30 years and above (3). as well as it also reported with unusual large follicular lesions (more than 3 cm) (6). however, in one of these large-size reported cases, the lesion identified within six months in 19 years old male (6). furthermore, garg et al. linked evidence of root resorption with fast-growing, unencapsulated aot lesion (20). the above explanations can not be applied to our case since it had short disease duration, small size and histologically well capsulated. the gross findings of our case were consistent with earlier descriptions of extrafollicular aot in the literature. microscopically, aot can form a hybrid growth with a histo-architectural variety containing both epithelial and mesenchymal components (6,7) or even associated with or arising from other odontogenic lesions especially in a young patient (9). there are several reports mentioned a combined aot/ceot lesions (1113,16). mosqueda-taylor et al. believed that such findings have no clinical or prognostic differences on the common aot. they considered the occurrence of areas of ceot-like tissue in "classic" aot is a spectrum of aot since there is no typical pleomorphism of the true ceot and the polyhedral cells confined to the nodular areas near the cyst lining and tend to produce mineralized tissue (14). they stated that aot cases without ceot-like areas were those who had few calcified material. however, our case contained few cells with pleomorphism and areas of clear cells within the ceot-like cells, which is an uncommon finding. beside that radiographically there were no calcified foci. tiny calcification is better to be examined by intraoral periapical radiographs. it is confirmed clinically and histologically that aot is a hamartoma. the existence of few tumor-like nodules (epithelial proliferation) that have inductive capacity in the cystic lesion is no more regarded as neoplasm growth despite their slow-growing property (2,6). nevertheless, it is worth to mention that the existence of clear cell ceot variant within the growth may suggest aggressiveness and associated with both root and cortical perforation and fast clinical swelling as seen in this case. aots alone or with ceot is a benign, encapsulated lesion, and conservative surgical enucleation or curettage is the treatment of choice. consequently, the tumor may be conservatively removed, with little or no danger of recurrence. for large tumors, subtotal resection may be necessary (2,21). as conclusion; this case report describes the first known case of extrafollicular aot associated with root resorption and containing clear-cell ceot-like area. since ceot with clear cell changes is known to recur more frequently, a lifelong follow-up of such patient may be required. references 1. barnes l, eveson j, reichart p, sidransky d. world health organization classification of tumours pathology and genetics of head and neck. lyon: iarc press; 2005. 2. regezi ja, sciubba jj, jordan rck. oral pathology: clinical pathologic correlations. 5th ed. st. louis: elsevier health sciences; 2012. 3. becker t, buchner a, kaffe i. critical evaluation of the radiological and clinical features of adenomatoid odontogenic tumour. dentomaxillofac radiol 2012; 41: 533-40. 4. philipsen hp, reichart pa, siar ch, et al. an updated clinical and epidemiological profile of the adenomatoid odontogenic tumour: a collaborative retrospective study. j oral pathol med 2007; 36(7): 383-93. 5. reichart pa, philipsen hp: odontogenic tumors and allied lesions. london: quintessence pub.; 2004. pp. 105-15. 6. kurra s, gunupati s, prasad pr, raju y s, reddy bvr. an adenomatoid odontogenic cyst (aoc) with an assorted histoarchitecture: a unique entity. j clin diagn res 2013; 7(6):1232-5. 7. mutalik vs, shreshtha a, mutalik ss, radhakrishnan, r. adenomatoid odontogenic tumor: a unique report with histological diversity. j oral maxillofac pathol 2012; 16(1): 2012–5. 8. zeitoun im, dhanrajani p, mosadomi ha. adenomatoid odontogenic tumor arising in a calcifying odontogenic cyst. j oral maxillofac surg 1996; 54(5): 634-7. 9. munde ad, karle rr, sachdev s, sahuji s. adenomatoid odontogenic tumour of the mandible arising from a dentigerous. j dent sci 2014; 2(1): 87– 91. 10. handschel jgk, depprich ra, zimmermann ac, braunstein s, kübler nr. adenomatoid odontogenic tumor of the mandible: review of the literature and report of a rare case. head face med 2005; 1(3): 1-5. 11. junquera gutierrez lm, albertos castro jm, floriano alvarez p, lopez arranz js. (combined epithelial odontogenic tumor). rev stomatol chir maxillofac 1994; 95(1): 27-9. 12. ledesma cm, taylor am, de león er, de la piedra garza m, jaukin pg, robertson jp. adenomatoid odontogenic tumour with features of calcifying epithelial odontogenic tumour. (the so-called combined epithelial odontogenic tumour.) clinicopathological report of 12 cases. eur j cancer part b oral oncol 1993; 29(3): 221-4. 13. miyake m, nagahata s, nishihara j, ohbayashi y. combined adenomatoid odontogenic tumor and calcifying epithelial odontogenic tumor: report of j bagh college dentistry vol. 28(2), june 2016 an extrafollicular cystic oral diagnosis 51 case and ultrastructural study. j oral maxillofac surg 1996; 54(6):788-793. 14. mosqueda-taylor a, carlos-bregni r, ledesmamontes c, fillipi rz, de almeida op, vargas pa. calcifying epithelial odontogenic tumor-like areas are common findings in adenomatoid odontogenic tumors and not a specific entity. oral oncol 2005; 41(2): 2145. 15. siar ch, ng kh. the combined epithelial odontogenic tumour in malaysians. br j oral maxillofac surg 1991; 29(2): 106–9. 16. rosa acg, lima srr, molini prb, furuse c, cavalcanti v, de araújo dds, passador-santos f. follicular adenomatoid odontogenic tumor with calcifying epithelial odontogenic tumor-like areas: report of a case with four years follow-up. oral surg oral med oral pathol oral radiol endodontol 2014; 117; e157-e158. 17. shivali v, pandey a, khanna vd, khanna p, singh a, ahuja t. a rare case of extrafollicular adenomatoid odontogenic tumour in the posterior region of the mandible: misdiagnosed as residual cyst. j int oral heal. jioh 2013; 5(5):124-8. 18. walia c, devi p, thimmarasa vb, vishal, mehrotra at. adenomatoid odontogenic tumor of the mandible extrafollicular variety: a rare case report. pakistan oral dent j 2010; 30(2): 348-51. 19. yilmaz n, acikgoz a, celebi n, zengin az, gunhan o. extrafollicular adenomatoid odontogenic tumor of the mandible: report of a case. eur j dent 2009; 3(1): 71-4. 20. garg d, palaskar s, shetty vp, bhushan a. adenomatoid odontogenic tumor hamartoma or true neoplasm: a case report. j oral sci 2009; 51: 155–9. 21. belouka sm, waluga r, schmidt-westhausen am, adolphs n, nobel cs. development and treatment of an extrafollicular adenomatoid odontogenic tumor. oral diseases 2012; 18: 34. j bagh college dentistry vol. 29(2), june 2017 the effect of nano pedodontics, orthodontics and preventive dentistry 90 the effect of nano-hydroxy apatite on re-mineralize white spot lesions prior to orthodontic adhesive removal by different techniques (an in vitro comparative study) saja sami malik, b.d.s. (1) nidhal hussain ghaib, b.d.s., m.sc. (2) abstract background: white-spot lesion is one of the problems associated with the fixed orthodontic treatment. the aims of this in-vitro study were to investigate enamel damage depth on adhesive removal when the adhesive were surrounded by sound, demineralized or demineralized enamel that had been re-mineralized prior to adhesive removal using 10% nano-hydroxy apatite and to determine the effect of three different adhesive removal techniques. materials and methods: composite resin adhesive (3m unitek) was bonded to 60 human upper premolars teeth which were randomly divided in to three groups each containing ten sound teeth and ten teeth with demineralized and re-mineralized lesions adjacent to the adhesive. a window of 2 mm was prepared on the buccal surface of the tooth and painted with an acid resistant nail varnish except for the window.the demineralized enamel produced by immersion of teeth in demineralization buffer for 12 days.half of the demineralized window, was covered with acid – resistant red nail varnish, and the samples were then subjected to re-mineralization with 10% of nano hydroxyapatite. the adhesive was removed with either :(1) fiber reinforced composite bur in slow speed handpiece (ss); (2)12 fluted long flame carbide bur in high speed handpiece (hs); (3) ultrasonic scaler (us).damage to the enamel was assessed using stereomicroscope with grid eye piece. results: the greatest to least mean depth of damage with three different adhesive removal techniques to sound enamel was hs˃ us ˃ss and to demineralized and re-mineralized enamel were ss ˃us˃ hs. sound enamel had the least amount of damage. re mineralization before the adhesive removal highly significant reduced the amount of damage produced by all techniques compared with demineralized enamel. conclusions: when the demineralized enamel was present 12 fluted long flame carbide bur were found to be the least damage in adhesive removal technique and re-mineralization further reduced the amount of enamel damage key word: nano-hydroxy apatite, re-mineralization, adhesive removal. . (j bagh coll dentistry 2017; 29(2):90-96) introduction the remarkable risk associated with orthodontic treatment is the enamel demineralization when oral hygiene is poor. inhibition of demineralization during orthodontic treatment is the largest challenges faced by orthodontist in spite of the recent development in caries prevention protocols. the progression of white spot lesions (wsls) is related to elongated plaque collection around the brackets (1, 2). fixed orthodontic appliances did not only cause traditional oral hygiene procedures more complicated, but also increase the number of plaque retention regions on the surfaces of the teeth that are normally less liable to caries progression (3). following the introduction of fixed orthodontic appliance into the oral cavity, a fast decrease in the bacterial flora of plaque happens. more numbers of acidogenic bacteria are found in the plaque, most notably streptococcus mutans, and lactobacilli (4). large numbers of bacteria are able to lower the ph of plaque in orthodontic patients to a greater level than in non-orthodontic (1) orthodontist daoudi specialized dental center,ministry of health. (2) professor, department of orthodontics, college of dentistry, university of baghdad. patients (5). therefore, the advancement of caries process is quicker in patients with fixed orthodontic appliances. wsls can become remarkable around the brackets within 1 month of bracket positioning, while the formation of regular caries usually takes at least six months (6). the most common location of these lesions are found on the buccal surfaces of teeth around the brackets, especially in the gingival region (7). earlier studies have demonstrated that the damage to enamel was caused by adhesive removal rather than removal of the bracket, preetch pumicing or during etching (8). the depth of damage to sound enamel, come from adhesive removal, has been showed to be as high as 150µm (9), but varies based on removal technique used (8, 10). an ideal adhesive removal technique would decrease iatrogenic damage while restoring the enamel to its pretreatment appearance, be clinically efficient for residual adhesive removal and have less discomfort or hazard to dental tissues. no one technique has been universally accepted as ideal or even superior to others in term of depth of damage to enamel and surface finish (11,12). a tungsten carbide bur in a high speed hand piece has been demonstrated to create better surface finish compared to the other j bagh college dentistry vol. 29(2), june 2017 the effect of nano pedodontics, orthodontics and preventive dentistry 91 techniques (13-15). a multiple step finishing approach has also been advocated with final polishing with rubber cups (13). aluminium oxide discs (16), or silicon carbide coated polisher to produce the smoothest final surface (17). however, all of these studies have examined adhesive removal from sound teeth without any surrounding demineralization. in addition to minimizing iatrogenic damage to wsls using an appropriate adhesive removal technique, an option exists for the practitioner to re-mineralize wsls prior to adhesive removal to further reduce enamel damage, and because there is no previous iraqi studies have examined enamel damage produced by different adhesive removal techniques on sound, de-mineralized and subsequently re-mineralized enamel by using nano hydroxy apatite therefore this study was conducted. materials and methods sample selection: from one hundred extracted human premolars 60 upper first premolars were selected, the extracted teeth were collected from the oral surgery department at the college of dentistry (baghdad university) and some private clinics in baghdad city and stored in 0.1% of thymol solution (de-ionized water with thymol crystals) (18). the teeth were selected after examination with 10x magnifying lens. any tooth with cracks, piting, wsl, or other enamel surface defects were excluded. teeth mounting: each tooth was fixed on a glass slide in a vertical position using soft sticky wax at the end of the root, so that the middle third of the buccal surface was oriented to be parallel to analyzing rod of the surveyor. after that a custom made cylindrical mold, made from plastic o f 2 cm in diameter and 2cm in depth, were painted with a thin layer of separating medium (vaseline) and placed around the vertically positioned teeth with crowns protruding. then the powder and liquid of the cold cured acrylic (duracryl® plus, spofa dental a kerr company 500gm powder and 250 ml liquid) were mixed and poured around the teeth to the level of the cemento-enamel junction of each tooth (19, 20). after mounting, the specimens were coded (g,green; r,red; b,blue) and stored in deionized water solution with thymol until bonding to prevent dehydration and bacterial growth (21,22). polishing the buccal surface of each tooth was polished using non fluoridated pumice in a rubber cup (for the standardization of this study one rubber cup was used for each tooth) attach to a slow speed hand piece then each tooth was washed with water spray, and dried with oil –free air. bonding procedure: this was done using self-etching primer \ bond (3m, st paul, mn, usa).a disposable brush was used for the application of the material on the enamel surface in gingivo-occlusal direction, then it was applied for a minimum 3-5 seconds per tooth with a light force. then an air source (oil free air/water syringe) was used to deliver a gentle air for 1-2 seconds for each tooth to dry the primer in to thin film then light cured (woodpecker, china) for 20 seconds (according to manufacture instruction). for each sample a maxillary first premolar bracket (stainless steel brackets \ortho technology-usa) was allocated and the mesh bonding surface was covered with a separating film (vaseline) prior to coating with composite resin adhesive (3m unitek, monrovia, ca, usa). they were then bonded to each tooth and the bracket was positioned in the middle third of the buccal surface parallel to the long axis of the teeth using a clamping tweezers. the adhesive was light cured for 40 second (20 seconds from mesial and 20 seconds from distal sides of brackets according to the manufacture instruction), at a distance of 5 mm (23). the bracket was then removed by tweezer leaving a relatively standardized bonded composite resin rectangles corresponding to the shape of maxillary first premolar bracket. acid resistant red nail varnish was used to outline a 2 mm wide window around the complete area of composite because this is the most common area for wsl to form (24). (figure 1) (1) (2) (3) figure 1: the steps of preparation the window on buccal surface of maxillary first permanent premolar around the adhesive these teeth were then classified into six subgroups according to adhesive removal techniques:  group g 1 (ss): in this group the adhesive removal was done using fiber reinforced composite bur (american dental accessories, usa) in slow speed hand piece (5000-10000 rpm) with water spray; (sound enamel not exposed to demineralization and remineralization). j bagh college dentistry vol. 29(2), june 2017 the effect of nano pedodontics, orthodontics and preventive dentistry 92  group r 1 (hs): in this group the adhesive removal was done using 12 fluted long flame carbide bur (ortho technology) in a high speed hand piece with water coolant; (sound enamel not exposed to demineralization and remineralization).  group b 1 (us): in this group the adhesive removal was done using ultra sonic scaler (cavitron, taiwan) with water coolant; (sound enamel not exposed to demineralization and re-mineralization).  group g 2 (ss): in this group the adhesive removal was done using fiber reinforced composite bur (american dental accessories) in slow speed hand piece (5000-10000rpm) with water spray; (the teeth exposed to demineralization & then re-mineralization)  group r 2 (hs): in this group the adhesive removal was done using 12 fluted long flame carbide bur (ortho technology/usa) in a high speed hand piece with water coolant; (the teeth exposed to demineralization & then remineralization).  group b 2 (us): in this group the adhesive removal was done using ultra sonic scaler (cavitron taiwan) with water coolant; (the teeth exposed to demineralization & then remineralization). the control teeth (sound enamel) of each group were immersed in the deionized water and thymol crystl while the tested samples of each group were exposed to demineralization and then re-mineralization prior to adhesive removal. in order to produce wsls in the exposed windows around the adhesive, all experimental samples were kept on the specimen jar lid, with 40 ml of the demineralization solution at ph 4.8 and 37◦c. this solution was changed every 48 hours for 12 days according to the method proposed by white (25). after the demineralization, each sample had acid resistant nail varnish painted over a randomly allocated half (right or left) of the demineralized window to create a demineralized half. the other half was exposed to a remineralizing solution containing (10% nano hydroxyl apatite) at ph 7 then all the samples except the controls were suspended in to the re-mineralization solution for 30 days with 4 minute twice daily (once at morning and once at night) at 37◦c with the solution changed every four days (24). following re-mineralization of sample, the nail varnish was carefully removed with acetone. the adhesive was removed by using the technique appropriate for each group. in the ss and hs groups, new bur was used per sample. in the us group the same scaler tip was used for all samples. in order to achieve standardization for adhesive removal, a modified dental surveyor with a suspending arm was used to control the hand piece orientation during adhesive removal. the samples of all groups were immersed in methylene blue at concentration of 2% for 24 hour in order to enhance the contrast in microscopic image then a ground section of 200 µm in thickness, perpendicular to the window surface were produced using an internal annulus saw minitom (struers, copenhagen, denmark). the study samples were examined under stereomicroscope (hamilton, italy) to evaluate enamel damage depth after the removal of adhesive. lesion depth was measured (in µm) for the demineralized and re-mineralized lesions and were compared with the sound enamel profile of the same section at magnification 4x using grid eye piece of steremicroscope. all of this procedures and measurments were done by specialist in oral histology department, collage of dentistry, university of baghadad. statistical analysis descriptive statistics including means and standard deviations were measured for each group using staitistical package of social science (spss) software (version 19 chiccago,usa) for windows xp. all data were examined for normality using shapiro-wilk test of normality. the depth of enamel damage were analysed using independent sample t test to compare the effect of demineralization and remineralization with control teeth , paired sample t-test to compare the depth of enamel damage in the demineralization and re-mineralization enamel for all groups and also using analysis of variance (anova) to compare the effect of adhesive removal techniques in each subgroup, finally least significant differences was used to show the significance between each two group after anova test. results table 1 showed the descriptive statistics that represent the mean and standard deviation of enamel damage depth in all techniques hs, ss and us for demineralized and sound enamel. independents sample t-test showed a highly significant increase in the enamel damage depth in demineralized enamel group when compared with sound enamel group p-value=0.000. table 2 consisted of the descriptive statistics that define the mean and standard deviation of enamel damage depth in all techniques hs, ss and us for re-mineralized and sound enamel independents sample t-test showed a significant increase in the enamel damage depth for hs technique p-value=0.029 and a highly significant j bagh college dentistry vol. 29(2), june 2017 the effect of nano pedodontics, orthodontics and preventive dentistry 93 increase in enamel damage depth for ss and us techniques when compared the re-mineralized enamel group with sound enamel. table 3 showed the descriptive statistics that represent the mean and standard deviation of enamel damage depth in all techniques hs, ss and us for re-mineralized and demineralized enamel. paired t-test showed a highly significant increase in the enamel damage depth in demineralized enamel when compared with remineralized enamel with p-value=0.000. (the greatest increase in depth of enamel damage was seen in ss group followed by us and then the hs lastly, table 4 summarized the mean and standard deviation (s.d.) of enamel damage depth for all studied techniques in control, demineralized and re-mineralized group. anova test showed a highly significant differences between the three studied techniques in all groups (control, demineralized and re-mineralized) p-value=0.000. the control group showed that the least enamel damage depth found in ss technique followed by us and then the hs technique, while the demineralized and re-mineralized groups showed that the lowest enamel damage depth found in hs techniques followed by the us and then the ss technique. table 5 using lsd test, showed a highly significant difference among sound, demineralized and re-mineralized groups between the (hs with ss), (hs with us) and (ss with us) in enamel damage depth. table 1: effect of demineralization on enamel damage depth (μm.) and comparing the effect of demineralization with the control group. techniques groups descriptive statistics groups' difference (d.f.=18) mean s.d. mean difference t-test p-value hs control 19.10 1.37 -20.40 -16.510 0.000 (hs) demineralization 39.50 3.66 ss control 7.60 2.17 -110.80 -60.406 0.000 (hs) demineralization 118.40 5.38 us control 15.90 2.77 -61.50 -32.448 0.000 (hs) demineralization 77.40 5.32 table 2: effect of re-mineralization on enamel damage depth (μm.) and comparing the effect of re-mineralization with the control group techniques groups descriptive statistics groups' difference (d.f.=18) mean s.d. mean difference t-test p-value hs control 19.10 1.37 -1.70 -2.365 0.029 (s) remineralization 20.80 1.81 ss control 7.60 2.17 -50.00 -30.568 0.000 (hs) remineralization 57.60 4.70 us control 15.90 2.77 -18.10 -14.167 0.000 (hs) remineralization 34 2.94 table 3: comparison between demineralization and re-mineralization groups of the enamel damage depth (μm.) techniques groups descriptive statistics groups' difference (d.f.=9) mean s.d. mean difference t-test p-value hs demineralization 39.50 3.66 18.70 17.732 0.000 (hs) remineralization 20.80 1.81 ss demineralization 118.40 5.38 60.80 46.240 0.000 (hs) remineralization 57.60 4.70 us demineralization 77.40 5.32 43.40 34.028 0.000 (hs) remineralization 34 2.94 j bagh college dentistry vol. 29(2), june 2017 the effect of nano pedodontics, orthodontics and preventive dentistry 94 table 4: enamel damage depth (μm) using different adhesive removal techniques groups techniques descriptive statistics techniques' difference (d.f.=29) mean s.d. f-test p-value control hs 19.10 1.37 74.197 0.000 (hs) ss 7.60 2.17 us 15.90 2.77 demineralization hs 39.50 3.66 661.763 0.000 (hs) ss 118.40 5.38 us 77.40 5.32 remineralization hs 20.80 1.81 306.682 0.000 (hs) ss 57.60 4.70 us 34.00 2.94 table 5: lsd test for the total sample groups techniques mean difference p-value control hs ss 11.50 0.000 (hs) us 3.20 0.003 (hs) ss us -8.30 0.000 (hs) demineralization hs ss -78.90 0.000 (hs) us -37.90 0.000 (hs) ss us 41.00 0.000 (hs) re-mineralization hs ss -36.80 0.000 (hs) us -13.20 0.000 (hs) ss us 23.60 0.000 (hs) discussion until now there is no evidence-based clinical protocol for the removal of orthodontic adhesive in patients who exhibit white spot lesions around their orthodontic appliance in order to minimize iatrogenic damage to tooth enamel. within the limitations of a laboratory based study, this study aimed to address this issue. there are significant differences in the studies regarding the effects of different adhesive removal techniques on sound enamel and this is attributed to the differences in operator techniques, materials and the methods used to assess damage. the result of the present study for sound enamel found that the use of ss in group g1 for adhesive removal resulted in a significantly less damaging than the use of either us in group b1 or hs in group r1. this is the first study which measures the depth of enamel damage after adhesive removal with fiber reinforced composite bur in slow speed handpiece. however, karan et al 2010(26). sogra et al 2015(27).found that the fiber reinforced composite bur created the smoothest enamel surface when compared with other methods. the us damage in group b1 found in the current study fell within this latter range in terms of the use of hs in group r1 for adhesive removal the results of the study are equivocal. hossien et al (8). ireland et al. (10) found that us resulted in enamel damage in range of 1.3 µm to 31.4 µm and showed the greater damage to sound enamel in comparison with other removal techniques. on the other hand krell et al (9) showed that a combined method utilizing pliers and an ultrasonic scaler produced damage of 38.5 ± 0.47 µm which was significantly less than hs removal technique used in that study. in the present study, a relatively comparable degree of damage was created by us in group b1 and hs in group r1removal techniques; 15.90 µm and 19.10 µm respectively, and both were significantly higher than ss in group g1. for demineralized and re-mineralized enamel the results of the present study, hs in group r2 was the least damaging technique. this is true for the depth of damage. hs were significantly lower than those of other removal techniques.us in group b2 resulted in a significantly less depth of damage to both demineralized and re-mineralized enamel in comparison with ss in group g2. it was noticed that the ss created a significantly greater area of damage to demineralized and remineralized enamel than other techniques. these dissimilarities in enamel damage and surface finishing between techniques could be attributed to varieties in their mechanisms of adhesive removal. hs includes high blade torque which demands less pressure from operator hand j bagh college dentistry vol. 29(2), june 2017 the effect of nano pedodontics, orthodontics and preventive dentistry 95 piece. this makes it less susceptible to differences in density of enamel, and consequently it reveled to create damage to both demineralized and sound enamel. unlike hs, ss removal has less torque demanding and greater pressure from operator hand piece, producing the least damage to sound enamel but fiercely cut and damaged remineralized and demineralized enamel. demineralized enamel damage seems also to be affected by variations in the time required for the adhesive removal using different methods. it seems that there is significant variability exists between operators with considerations to this, attributed to variations in technique and experience. re-mineralization of enamel with 10% nha led to a reduction in depth of damage regardless of the type of adhesive removal technique used. a postulated rationale for this is that the nha treatment was able to increase the mineral content of demineralized enamel and became able to withstand the damaging forces applied during adhesive removal. this finding was in agreement with cochrane et al (24) and mayne et al (28) who found that the re-mineralization of a wsl surrounding an orthodontic bracket before bracket and adhesive removal might reduce the depth of enamel damage while the re-mineralized enamel was still damaged to a greater degree than sound enamel, it showed significantly less than that of demineralized enamel. the results of this in vitro study demonstrated that the re-mineralization would decrease the enamel damage prior to adhesive removal when wsl were found. references 1. gorelick l, geiger am, gwinnett aj. incidence of white spot formation after bonding and banding. am j orthod 1982; 81(2):93–8. 2. ogaard b. prevalence of white spot lesion in 19-yearolds: a study on untreated and orthodontically treated persons 5 years after treatment. am j orthod dentofacial orthop 1989; 96:423427. 3.øgaard b. white spot lesions during orthodontic treatment: mechanisms and fluoride preventive aspects. semin orthod 2008; 14:183–193. 4. lundstrom f, krasse b. streptococcus mutans and lactobacilli frequency in orthodontic patients: the effect of chlorhexidine treatments. eur j orthod 1987; 9:109–116. 5. chatterjee r, kleinberg i. effect of orthodontic band placement on the chemical composition of human incisor plaque. arch oral biol1979; 24:97–100. 6. ogaard b, rølla g, arends j.orthodontic appliances and enamel demineralization. part 1. lesion development. am j orthod dentofacial orthop 1988; 94: 6873. 7. mitchell l. decalcification during orthodontic treatment with fixed appliances—an overview. br j orthod1992; 19: 199–205. 8. hosein i, sherriff, m, ireland aj. “enamel loss during bonding, debonding, and cleanup with use of a selfetching primer.” american journal of orthodontics & dentofac orthop 2004; 126:717-72. 9. krell kv, courey jm, bishara se.orthodontic bracket removal using conventional and ultrasonic debonding techniques, enamel loss, and time requirements. am j orthod dentofac orthop 1993; 103: 258– 66. 10. ireland aj, hosein i, sherriff m. enamel loss at bondup, debond and clean-up following the use of a conventional light-cured composite and a resinmodified glass polyalkenoate cement. eur j orthod 2005; 27:413-49. 11. pus md, way dc. enamel loss due to orthodontic bonding with filled and un filled resin using various clean-up techniques. am j orthod 1980; 77:269283. 12. cehreli zc, lakshmipathy m, yazici r. effect of different splint removal techniques on the surface roughness of human enamel:a three-dimensional optical profilometry analysis. dent traumatol 2008; 24:177-182. 13. retief dh, denys fr. finishing of enamel surfaces after debonding of orthodontic attachments.angle orthod1979; 49(1):1–10. 14. campbell pm. enamel surfaces after orthodontic bracket debonding. angle orthod 1995; 65:103–110. 15. hong yh, lew kk. quantitative and qualitative assessment of enamel surface following five composite removal methods after bracket debonding. eur j orthod 1995; 17:121-8. 16. zarinnia k, eid nm, kehoe mj. the effect of different debonding techniques on the enamel surface: an in vitro qualitative study. am j ortho dentofacial orthop 1995; 108:284-93. 17. ulusoy c. comparison of finishing and polishing systems for residual resin removal after debonding j appl oral sci 2009; 173209–15. 18. parry j, shaw l, arnand mj, smith aj. investigation of mineral waters and soft drinks in relation to dental erosion. j oral rehabil 2001; 28: 766-72. 19. rajagopal r, padmanabhan s, gnanamani j. acomparison of shear bond strength and debonding characteristics of conventional, moisture-insensitive, and self –etching primers in vitro. angle orthod 2004; 74 (2):264-8. 20. montasser m, drummond j, roth jr, al-turki l, evans ca. rebonding of orthodontic brackets. part ii, an xps and sem study. angle orthod 2008; 78(3): 537-44. 21. millett dt,letters s, roger e, cummings a, love j. bonded molar tubes-an in vitro evaluation. angle orthod 2001;71(5):380-5. 22. cozza p, martucci l,de, toffol l, penco si.shear bond strength of metal brackets on enamel. angle orthod 2006; 76(5):851-6. 23. malkoc s, uysal t,usumez s, isman e,baysale a. in –vitro assessment of temperature rise in the pulp during orthodontic bonding.am j orthod dentofac orthop 2010; 137(3): 379-5. 24. cochrane nj, ratneser s, reynolds ec. effect of different orthodontic adhesive removal techniques on sound, demineralized and remineralized enamel. australian dental journal 2012; 57: 365-372. 25. white dj. use of synthetic polymer gels for artificial carious lesion preparation. caries res 1987; 21: 228242. j bagh college dentistry vol. 29(2), june 2017 the effect of nano pedodontics, orthodontics and preventive dentistry 96 26. karan s, kircellli b, tasdelen b. enamel surface roughness after debonding comparison of two different burs. angle orthod2010; 80 (6):1081-8. 27. sogra y, hossein a,neda j. effects of removing adhesive from tooth surfaces by er:yag laser and a composite bur on enamel surface roughness and pulp chamber temperature. dent res j 2015;12 (3): 254– 259. 28. mayne rj, cochrane nj, cai f, woods mg, reynolds ec. in-vitro study of the effect of casein phosphopeptide amorphous calcium fluoride phosphate on iatrogenic damage to enamel during orthodontic adhesive removal. am j orthod dentofacial orthop 2011; 139: 543– 55. المستخلص لمختبریھ اجریت للتحقیق في ھذه الدراسھ ا .قد تكون عرضھ ال ضرار میكانیكیة اثناء ازالة الصق تقویم االسنان المتكونة على سطح السن البقعھ البیضاءالخلفیة: قبل قد فقدت المعادنة المعادن للمینا التي اعادفي حال او معادن ینا سلیمھ او مینا فاقده للبم االالصقھ محاطھفي حال كون عند ازالة الالصقالسن مینا عمق ضرر وتحدید اثر ثالثة تقنیات مختلفھ من تقنیات ازالة الصق تقویم االسنان. nano hydroxyl apatite%10بأستخدام ازالة الالصق من عشرة قسمت الى ثالث مجموعات كل مجموعھ تتكون.الغراض تقویمیة ویھ السلیمھ المقلوعةالضواحك العلتم أختیار ستون سنا بشریا من : البحث مواد وطرق االمینا المحاذي للحاصرة ملم على سطح 2ر یشملاسنان ذات مینا فاقده للمعادن في المنطقھ المجاوره لالصقھ تقویم االسنان.تم اعداد اطا أسنان سلیمھ وعشرة یوم,نصف النافذه الفاقده للمعادن كانت 12لمدة المخزن القواعدبعد التعرض الى انتجتوالتي وم للحامض باستثناء النافذه المینا الفاقده للتمعدن مقا باستخدام طالء )1بثالث طرق مختلفھ (وتمت ازالة االصق nano hydroxyl apatite %10ن بواسطة مغطاة بطالء اظافر مقاوم للحامض ثم تعرضت العینات العادة التمعد ,وتم قیاس عمق لموجات فوق الصوتیةا قشارة ب )3بھاندبیس عالیة السرعھ ( طولي اللھببیر دیكاربا مخدد12 )2بھاندبیس بطیئة السرعھ ( بیر لیفي معززبمركب باستخدام عدسھ مرقمة.و الضرر للمینا بواسطة المایكروسكوب المجسم .وعمق الضرر للمینا الفاقدة للمعادن والمینا بعد اعادة ss < us < hs أن عمق الضرر للمینا السلیمھ من االعلى الى االقل كاالتيكشفت نتیجة الدراسة بالنتائج: . اقدة للمعادناعادة التمعدن قبل ازالة الالصق یقلل كمیة الضرر للمینا مع كل تقنیات ازالة االصق عند مقارنتھ مع المینا الف. hs < us < ss التمعدن كاالتي فلوتد لونك فلیم كاربید بیر بواسطة ھاندبیس عالیة السرعھ یقلل الضرر للمینا عندما 12ضمن حدود ھذه الدراسة المختبریھ یمكن ان نستنتج ان استخدام االستنتاج: تكون المینا المجاورة لالصقة فاقده للتمعدن,وان اعادة التمعدن قبل ازالة الالصق یقلل من مقدار عمق الضرر للمینا. sahar.doc j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 151 augmentation of the localized bony defect s with synthetic bone substitute in simultaneous dental implant surgery (clinical study) mohammed abdalrazaq hameed, b.d.s. (1) sahar shaker al-adili, b.d.s, m.sc. (2) abstract background: simultaneous and staged guided bone regeneration (gbr) is one of the several surgical techniques that have been developed in the past two decades to regenerate bone and thus to allow implant placement in compromised sites (fenestration and dehiscence). it is a surgical procedure that consists of the placement of a cell-occlusive physical barrier between the connective tissue and the alveolar bone defect. the treatment concept advocates that regeneration of osseous defects is predictably attainable via the application of occlusive membranes, which mechanically exclude non-osteogenic cell populations from the surrounding soft tissues, thereby allowing osteogenic cell populations originating from the parent bone to inhabit the osseous wound. augmentation utilizing guided bone regeneration (gbr) has become a major treatment option to provide optimal bone to support osseointegrated dental implants. one of the objectives of gbr is the formation of new bone at sites deficient in bone volume. another objective is to treat fenestrations and dehiscence at implant surfaces as well as defects associated with simultaneous implant placement. gbr has allowed for placement of restorations at a more ideal location in the oral cavity, thus improving esthetics and functions. this study aimed to improve the alveolar ridge width by using of synthetic bone substitute covered by resorbable collagen membrane in simultaneous dental implants placement and to compare the ridge width at three levels (crestal, middle and apical) clinically (osteometer) and radiographically (ct) pre operatively and postoperatively. materials and methods: this prospective study was conducted in teaching dental hospital in college of dentistry of baghdad university on (15) patients with (21) dental implant with insufficient bony support for simultaneous dental implants , this study extended from march 2013 to the end of december 2013. all patients were treated at the time of implantation by using a synthetic bone substitute covered by resorbable collagen membrane .all patients examined clinically by osteometer and radio graphics (ct) to assess ridge width and height and bone density. results: clinically and radiographically evaluation showed increasing of ridge width after 6 months of healing period at three levels: apical, middle and crestal, statistically, there were no significant differences between ridge width gain measured clinically and radio graphically and gender and age groups. in this study the success rate (95.24) % in (20) dental implant and only (1) dental implant was failed (4.76) % at age 47 years old. conclusion: there was significant increase in ridge volume that augmented at the time of implantation to become sufficient width for support implant esthetically and functionally. this study revealed that there was no effect in gender and age on bone augmentation with synthetic bone substitute. keywords: gbr, simultaneous dental implant, osteometer, ct, ridge width and height and bone density. (j bagh coll dentistry 2015; 27(1):151-158). introduction dental implants are considered nowadays by most of patients and clinicians as the first line of treatment in restoring missing teeth. over the last fifty years, when teeth are lost due to trauma, infection or advanced gum disease, insufficient bone can be found at the missing teeth area which can influence the aesthetics, and long term prognosis of the dental implants and their prosthetic super structure. in such cases, dental implant therapy would not be an option without horizontal and/or vertical bone augmentation (1).guided bone regeneration (gbr) is a reconstructive procedure of alveolar ridge using membranes. this procedure is indicated when there is no sufficient bone for implantation, or in the case of optimal implant installation for esthetic or functional needs. (1) master student, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. gbr can be performed before implant placement, when there is not enough bone for initial stability of implants and less predictable outcomes (staged approach), or performed simultaneously with implantation (combined approach). gbr techniques have been used for vertical and horizontal ridge augmentations with acceptable results (2). guided bone regeneration is based on principles of guided tissue regeneration (gtr). (3) gtr was first developed in the early 1980s by nyman et al.(3) this concept is based on the principle that specific cells contribute to the formation of specific tissues (4).exclusion of fastgrowing epithelium and connective tissue from a periodontal wound for 6-8 weeks allows the slower growing tissues including osteoblasts, cementoblasts, and periodontal ligament cells, occupy the space adjacent to the tooth (3,5). gbr concept employed the same principles of specific tissue exclusion but was not associated with teeth. j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 152 calcium phosphate (cap)-based materials that have been used in craniofacial surgery for more than 100 years represent an attractive candidate because of their outstanding properties as bone substitutes and as drug delivery vehicles (6,7,8,9). due to their self-hardening and appropriate mechanical properties, high osteoconductivity, excellent surface chemistry and surface topography to bone defect surfaces,cap-based biomaterials can be used with outstanding results in a number of dental applications, including ridge augmentation, implant coating, bone defect fill and sinus lift (10). there are five criteria considered important in the design of barrier membranes that are used for gtr. these include biocompatibility, cell occlusiveness, space making, tissue integration and clinical manageability. various types of materials have been developed, which can be grouped together as either non resorbable or irresorbable membranes (11, 12). computerized tomography (ct)-based dental imaging for implant planning and surgical guidance carries both restorative information for implant positioning, as far as trajectory and distribution, and radiographic information, as far as depth and proximity to critical anatomic landmarks such as the mandibular canal, maxillary sinus, and adjacent teeth(13). the success of gbr is one of the important parts of implant dentistry. the first generation definition of success was the ability of complete cover of a dehisced or fenestrated implant surface with regenerated hard tissue (14). the secondgeneration definition of success was the regeneration of a sufficient dimension of bone to withstand functional forces overtime (15). materials and methods study sample: this study was based upon clinical, radiographical and surgical data, a total of (21) dental implants in (15) iraqi patients aged 20-50 years old, 7 males and 8 females attended to the teaching dental hospital in college of dentistry of baghdad university. this study extended from march 2013 to the end of december 2013. selective criteria of the study sample: 1. the patients were selected according to medical and potential implant site evaluation; sample individual with no history of any systemic diseases. 2. cases selected with good oral hygiene, nonsmokers and no complications were recorded during previous dental treatments. 3. age group ranged from 20 to 50 years old. 4. potential implant site: a. the target regions are anterior and premolar regions (traumatic zones and sinus zone “only 2nd premolar”). b. implant sites with defect at maximum width of alveolar ridge ≤5 mm.(insufficient width). 5. patients case record: following data were recorded in specially prepared case sheet form (see the case sheet in the appendix): a. general information including name, age, gender, address, occupation and phone number. b. etiology of edentulism: caries, trauma, periodontal disease and occlusal trauma. clinical examination: extra oral: facial asymmetry was examined and smile line either dental or gingival in addition to the mouth opening. intra oral all teeth were examined ,the gingival, periodontal conditions and teeth mobility, the implant potential area was examined carefully for missing teeth to be replaced by di, hygiene, pathological lesions, depth of vestibule, width of alveolar ridge, ridge height, vestibular concavity, vertical bone resorption, mesiodistal distance and gingival thickness. radiographical examination: msct scan were performed preoperative for each patient to determine the ridge width and bone density at three levels (crestal, middle and apical) on ct slices. after 6 months the same ct repeated for each patient and determined the ridge width and bone density also at three levels (crestal, middle and apical). materials: bone substitute of lifting-osteon ii (dentium system, korea), this is 100% synthetic osteoconductive bone graft substitute composed of hydroxyapatite (ha) 70% and beta tricalcium phosphate(b-tcp) 30%,collagen type membrane which is a resorbable membrane 0.3mm in thickness, size (10×20., 15×20, 20×30)mm is used, (dentium system, korea), dental implant: the dental implants used in this study are dentium system (korea), implant surgical kit (dentium system, korea) and implan micromotor: controlling speed micro motor (w&h; austria). j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 153 methods: radiographic and clinical evaluation: a multi slices spiral computed tomography (msct) (philips , brilliance 64) was performed in al-karkh general hospital for each patient to assess the ridge height , bone density and ridge width at three levels 1st, crestally and 2nd about 3mm apically from the 1st level and 3rd level about 3mm apically from 2nd level. clinically use ridge caliper (osteometer, germany) and reamer in measuring bone width also at three levels same as to measurement by ct, the reamer inserted in the gingiva at top of the crest to measure the thickness of the gingiva .the bucco-palatal width was measured by ridge caliper (osteometer) after determine the level of ridge crest , this measurement reveal the net of total width of ridge bone at three levels same to that on ct evaluation pre operatively, record these measurement that obtained by ct and osteometer. surgical procedure: all patients were treated under local anesthesia using lidocaine (france) by infiltration technique, the oral mucosa in the implantation site was incised palatal to the defect in alveolar ridge, three sided full thickness flap was raised to expose the implant site. the point of insertion on the bone was marked with the help of a lindemann guide bur; this was followed by the use of a lindeman first drill at a bur speed of 800rpm to 1000 rpm with copious irrigation with normal saline. the depth stop of all instruments at selected implant length that determined according to ridge height that obtained from msct. then use a final drill according to width of ridge that determined previously according to the diameters measurement obtained by ct and osteometer. the implant is opened from the sterile packaging and placed in implant recipient site with hand pressure, the fenestration (apicaly) or dehiscence (cervicaly) may be occurred due to insufficient width of alveolar bone for support the simultaneous placement dental implant. the b-tricalcium phosphate sterile resorbable substitute was used, these material injected into the defect, the graft material mixed with normal saline in tube of material and with blood from the recipient site at the defect site. after placement of bone substitute the membrane was covering the bone substitute, collagen type (korea) which is resorbable membrane. select the size of membrane according to defect morpholgy, the membrane adapted to the defect, any exposed material was removed. next the periosteium of mucoperiosteal flap cut at its base to mobilize the flap and allow to cover the bone substitute without tension, the flap was closed over the graft and implant using interrupted sutures silk (3/0). post operatively broad spectrum antibiotic (azithromycin 500mg ,1 tab per day) was prescribe for 1 week, analgesic (paracetamol 500 mg) on need and chlorohexidine 0.2% mouth rinse (lacalute company, germany) used for 2 week (1minutes, two times daily). two weeks post-surgery the sutures were removed. follow up: after healing period of 180 days another x-ray (msct) was repeated again for each patient the measurements like pre-operative were taken to evaluate width and density of the alveolar bone ridge at three levels at (crestal, middle, apical) clinically the ridge width was measured by ridge caliper (osteometer) at three levels as same as pre operatively. figure 1: pre operative alveolar ridge and pre operative ct at premolar area showing implant zone j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 154 (a) (b) figure 2: (a) using reamer to measure gingival thickness pre-operative. (b)pre operative ct view implant site (a) (b) figure 3: (a).pre operative measurement the ridge width clinicaly by osteometer (b).preoperative alveolar ridge width measurement on ct at three levels (a) (b) figure 4: (a) fenestration and dehescince at premolar implant zone (b) placement of bone substitute on bony defect (fenestration and dehescince) and placing of the collagen membrane over bone substitute results clinical measurements of the width of the alveolar ridge table 1 showed the descriptive statistics and comparison of the width of the alveolar ridge pre and post-operatively at different levels. generally, the width of the ridge increased significantly postoperatively at different levels specially at the apical level. j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 155 figure 5: post operative alveolar ridge width clinicaly by osteometer and ct and density measurement at three levels on ct after 6 months figure 6: implant on ct in relation to adjacent strctures andbone substitute on ct after 6 months figure 7: prosthetic part inside patient mouth after cementation computed tomographic measurements of the width of the alveolar ridge the descriptive statistics and comparison of the width of the alveolar ridge preand postoperatively at different levels measured by c.t. were presented in table 2. the results revealed a significant increase in the width of the alveolar ridge post-operatively at the different measured levels. assessment of the bone density table 3 show mean bone density measured with c.t. both preand postoperatively at the same levels. the results indicated that there is significant increase in bone density postoperatively in comparison with pre-operative state. comaprison the method of alveolar ridge measurements 1. comaprison the method of alveolar ridge measurements pre-operatively table 4 showed a comparison of pre-operative measurement of ridge width between the clinical and c.t. methods at the three levels. statistically, the width of the alveolar ridge is higher clinically than with c.t. with no significant difference between the two methods at the crestal and middle levels, while significant difference was found between the methods at apical level. j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 156 table 1: descriptive statistics of the width of the ridge (mm.) measured clinically and comparison between the pre and post-operative states levels pre-operative post-operative comparison median mean s.d. s.e. median mean s.d. s.e. wilcoxon signed ranks test p-value crestal 3.75 3.38 1.09 0.24 5 5.10 0.85 0.19 -3.645 0.000 (hs) middle 5 4.63 0.79 0.18 7 6.95 1.10 0.25 -3.857 0.000 (hs) apical 5.25 5.35 0.86 0.19 9 8.68 1.17 0.26 -3.967 0.000 (hs) table 2: descriptive statistics of the width of the ridge (mm.) measured by c.t. and comparison between the pre and post-operative states levels pre-operative post-operative comparison median mean s.d. s.e. median mean s.d. s.e. wilcoxon signed ranks test p-value crestal 2.65 2.97 0.91 0.20 5.3 5.31 0.97 0.22 -3.921 0.000 (hs) middle 3.85 3.86 0.80 0.18 6.5 6.80 1.56 0.35 -3.922 0.000 (hs) apical 4.65 4.66 0.88 0.20 7.1 7.33 2.10 0.47 -3.922 0.000 (hs) table 3: descriptive statistics of the bone density (hounsfield unit) measured by c.t. and comparison between the pre and post-operative states levels pre-operative post-operative comparison median mean s.d. s.e. median mean s.d. s.e. wilcoxon signed ranks test p-value crestal 421 492.25 260.79 58.32 825 820.50 354.78 79.33 -3.920 0.000 (hs) middle 552.5 580.10 247.08 55.25 967.5 923.15 387.54 86.66 -3.211 0.000 (hs) apical 538.5 550.00 242.64 54.25 693 765.55 230.93 51.64 -3.323 0.000 (hs) table 4: comparison between the two methods used to measure the pre-operative ridge width levels clinically c.t. comparison median mean s.d. s.e. median mean s.d. s.e. wilcoxon signed ranks test p-value crestal 3.75 3.38 1.09 0.24 2.65 2.97 0.91 0.20 -1.852 0.064 (ns) middle 5 4.63 0.79 0.18 3.85 3.86 0.80 0.18 -0.784 0.433 (ns) apical 5.25 5.35 0.86 0.19 4.65 4.66 0.88 0.20 -2.860 0.004 (hs) 2.comaprison the method of alveolar ridge measurements post-operatively table 5 showed a comparison of post-operative measurement of ridge width between the clinical and c.t. methods at the three levels. generally, the width of the alveolar ridge is higher clinically than with c.t. with a significant difference between the two method at the middle and apical levels, while non-significant difference was found between the two methods at crestal level. table 5: comparison between the two methods used to measure the post-operative ridge width levels clinically c.t. comparison median mean s.d. s.e. median mean s.d. s.e. wilcoxon signed ranks test p-value crestal 5 5.10 0.85 0.19 5.3 5.31 0.97 0.22 -0.635 0.525 (ns) middle 7 6.95 1.10 0.25 6.5 6.80 1.56 0.35 -2.316 0.021 (s) apical 9 8.68 1.17 0.26 7.1 7.33 2.10 0.47 -2.483 0.013 (s) percentage of success and failure rates table 6 showed percentage of success rate (95.24%) for (20) dental implant and percentage of failure rate (4.76%) for (1) dental implant. table 6: percentages of success and failure state no. % success 20 95.24 failure 1 4.76 total 21 100 j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 157 discussion in this study, there were 15 patients with insufficient bony support for 21 dental implant placement, 7 males (46.67%) and 8 female (53.33%) according to statistical analysis using wilcoxon signed ranks test, this study revealed that was highly significant increase in ridge width at three levels (crestal. middle and apical) that measured clinically and radiographically (ct). so the mean value of ridge width at (crestal.middle and apical) levels measured clinically preoperative were (3.38 , 4.63 and 5.35)mm and after 6 months of healing period these measurements show increase in width resulting good bony support and adequate ridge width for implant placement, so, mean value of ridge width at (crestal.middle and apical) levels measured clinically postoperative were (5.10 , 6.95 and 8.68 ) mm respectively. ct scan also used for assessment of ridge width pre and post operatively at three levels ( crestal , middle and apical) and also presented highly significant increase in ridge width at three levels , the mean value of ridge width that measured by ct preoperatively were (2.97, 3.86 and 4.66) mm crestal ,middle and apical in sequence . and also after 6 months the all patients reexamined by ct and we found there were increase in ridge width, so, the mean value of ridge width became (5.31, 6.80 and 7.33) mm. it has been suggested that that increasing in ridge width is due to the proper selection of patients (healthy ,non smokers and patients follow our oral care instructions) and use of best synthetic bone substitute consist of beta tri calcium phosphate (b-tcp) and hydroxyapatite (ha), similar to that human cancellous bone covered by resorb able collagen membrane made a cell-occlusive physical barrier between the connective tissue and the alveolar bone defect. this barrier prevents the migration of the soft tissue into the defect and creates a protected space in which the blood clot and the graft are stabilized. epithelial and connective tissue cell migration is avoided and the slow migrating osteogenic cells can proliferate, with subsequent formation of new bone leading increase in ridge width and the membrane was absorbable ,so no need second surgical operation to remove it and it was biocompatible does not produce any side effect. we select all our patients were non smokers to avoid the complication and failure because of in smokers patients the blood supply to the soft and bony tissues was much reduced , and that there are higher risks of postoperative infections . these were supported by rosenberg et al. (16), in a retrospective analysis of a longitudinal study of gtr procedures reported a 42% failure rate after at least 4 years, however, 80% were in patients who smoked at least 10 cigarettes per day for 5 years. so we were selected all our patients are nonsmokers to avoid the complication and failure and increase the success rate (95.24%). the bone density of alveolar ridge that measured preoperative at three levels by ct range from (d2-d5) show highly significant increase in comparison between pre and post operative measurements, while in postoperative, bone density range from (d1-d4) the success rate in our study (95.24%) while failure rate (4.76%), these were supported by fugazzotto in 1997 (17) published an article on this subject , failure and success rates of 626 implants either placed in regenerated alveolar bone or treated with guided bone regeneration to rebuild bone over implant fenestrations or dehiscences were evaluated. the cumulative success rate of implants in function in regenerated bone for 6-51 months was 93.8%. reasons for high success rate in our study were: 1. resorbable collagen membrane protect bone substitute and stabilize blood clot. 2. good instruction given to patients. 3. proper selection of patients (healthy, non smokers and no medication), these in agreement with buser et al (18) report successful ridge augmentation with gbr in humans using an e-ptfe membrane and tenting pins. all patients were examined clinically by using osteometer and also radiographically (ct) these two methods were used to assess the ridge width ,statistically , generally the width of the alveolar ridge is higher clinically than with c.t with there were no significant differences between these methods in determination of ridge width at crestal and middle preoperative. while at apical level the width of the alveolar ridge is higher clinically than with c.t, in post operative re-examination ,statistically, generally revealed the width of the alveolar ridge is higher clinically than with c.t. a significant difference between the two method at the middle and apical levels, while non-significant difference was found between the two methods at crestal level these differences were due to difficult to assess clinically precisely. references 1. esposito m, grusovin mg, felice p, karatzopoulos g, worthington hv, coulthard p. interventions for replacing missing teeth: horizontal and vertical bone augmentation techniques for dental implant treatment. j bagh college dentistry vol. 27(1), march 2015 augmentation of oral and maxillofacial surgery and periodontics 158 cochrane database of systematic reviews 2009; issue 4. 2. farzad m, mohammadi m. guided bone regeneration: a literature review. j oral health oral epidemiol 2012; 1(1): 3-18 3. nyman s, karring t, lindhe j, planten s. healing following implantation of periodontitis-affected roots into gingival connective tissue. j clin periodontol 1980; 7(5): 394-401. 4. melcher ah. on the repair potential of periodontal tissues. j periodontol 1976; 47(5): 256-60. 5. karring t, nyman s, lindhe j. healing following implantation of periodontitis affected roots into bone tissue. j clin periodontol 1980; 7(2): 96-105. 6. daculsi g. biphasic calcium phosphate concept applied to artificial bone, implant coating and injectable bone substitute. biomaterials 1998; 19:1473-8. 7. bohner m, gbureck u, barralet je. technological issues for the development of more efficient calcium phosphate bone cements: a critical assessment. biomaterials 2005; 26: 6423–9. 8. suzuki o, kamakura s, katagiri t. surface chemistry and biological responses to synthetic octacalciumphosphate. j biomed mater res b appl biomater 2006; 77: 201-12. 9. ginebra mp, traykova t, planell ja. calcium phosphate cements as bone drug delivery systems: a review. j controlrelease2006; 113:102–10. 10. hallman m, thor a. bone substitutes and growth factors as an alternative/complement to autogenous bone for grafting in implant dentistry. periodontol 2000 2008; 47: 172–92. 11. hardwick r, hayes bk, flynn c. devices for dentoalveolar regeneration: an up-to-date literature review. j periodontol 1995; 66(6): 495-505. 12. greenstein g, caton jg. biodegradable barriers and guided tissue regeneration. periodontol 2000 1993; 1: 36-45. 13. dov m almog, james lamar, frank r. lamar, frank lamar. ct-based dental imaging implants planning surgical template imaging guide. j oral implantol 2006; 32: 2. 14. mellonig jt, triplett rg. guided tissue regeneration and endosseous dental implants. int j periodontics restorative dent 1993; 13(2): 108-19. 15. fugazzotto pa. implant and regenerative therapy in dentistry: a guide to decision making. 1st ed. new delhi: wiley-blackwell; 2009. 16. rosenberg es, cutler sa. the effect of cigarette smoking on the long-term success of guided tissue regeneration: a preliminary study. ann r austr alas coll dent surg 1994; 12: 89-93. 17. fugazzottopa. success and failure rates of osseointegrated implants in function in regenerated bone for 6 to 51 months: a preliminary report. int j oral maxillofac implants 1997; 12(1): 17-24. 18. buser d, bragger u, lang np, nyman s. regeneration andenlargement of jaw bone using guided tissue regeneration. clin oral implants res 1990; 1: 22-32. الخالصة ا في العقدین الماضیین لتجدید العظام و بالتالي السماح ھي واحدة من العدید من التقنیات الجراحیة التي تم تطویرھعملیة إعادة تولید العظام التزامنیھ والتتابعیة :خلفیة عن الدراسة ذلك ھو إجراء العملیات الجراحیة التي تتكون من وضع عظم إصطناعي مغطى بغشاء فاصل بین النسیج الضام اللثوي والعظم السنخي ) نقص العظم(بزرع العظام في مواقع الخلل میة ھو متوقع ویمكن بلوغھ عن طریق تطبیق األغشیة المسدودة ، والتي تستبعد میكانیكیا التجمعات الخالیا غیر المكونة للعظم عن مفھوم العالج یتضمن بأن تجدید العیوب العظ . للفك الخیارالرئیسي لتوفیر ( gbr ) أصبحت زیادة استخدام عملیة تجدید العظام . األنسجة الرخوة المحیطة ، مما یتیح للخالیا المكونة للعظم أن تنشأ من عظم األم لتسكن الجرح العظمي نفاذیة وظھور ھدف آخر ھو لعالج .ھو تشكیل عظام جدیدة في مواقع نقص في حجم العظام gbr واحدة من أھداف.العظام األمثل لدعم التحام متكاملة زرعة االسنان مرتبطة بالعظم بوضع الترمیم في مواقع أكثر مثالیة في تجویف الفم ، وبالتالي gbr وقد سمح.الناجم على سطوح العظام التي تمت الزرع علیھا وكذلك العیوب المرتبطة بالزرع التزامني الزرعة .تحسین الشكل الجمالي والوظیفة .المستخدم في زراعة األسنان التزامنيالقابل للذوبانغشاء الكوالجینب ظام االصطناعیة المغطاةالناجم عن استخدام بدیل الع) الُسمك( تحسین حجم عظم الفك : ھدف الدراسة زرع األسنان مع دعم عظمي عملیة 21مریض ولدیھم ) 15( تم إستخدام ھذه الدراسة في تدریس طب األسنان في مستشفى كلیة طب األسنان في جامعة بغداد ل : المواد و الطرق تم فحص جمیع . القابل للذوبان تم عالج جمیع المرضى في وقت الزرع من قبل باستخدام بدیال العظام االصطناعیة عن طریق غشاء الكوالجین. راعة األسنان الفوریة غیر كافي لز / ُأجریت ھذه الدراسة في الفترة من مارس .كثافة العظام لتقییم ُعرض النتوء وإرتفاعھ و)ct(والرسومات الرادیویة جھاز قیاس ُسمك العظم (osteometer)المرضى سریریا من قبل .2013كانون األول / إلى نھایة دیسمبر 2013اذار رض النتوء قبل عفأن متوسط , سریریا .ط والذیليفي القمة والمتوس: أشھر من فترة الشفاء في ثالثة مستویات 6بینت التجارب السریریة والشعاعیة تزایدًا في ُعرض النتوء بعد :النتائج عرض النتوء بعد العمل قیمة متوسط . أشھر أصبح عرض النتوء كافیا لدعم زرع األسنان بشكل جمالي ووظیفي 6ملم في على التوالي و بعد ) 5.35و 3.38،4.63( الجراحة كان 7.33، 6.80(بعد الزرع ،ملم واصبخت ھناك زیادة ھذه القیاسات2.97،3.864.66( و قیمة المعدل قبل الجراحة باألشعة السینیة . ملم ) 5.10،6.958.68( الجراحي أصبح .ملم في الثالث مستویات)5.31و عة العمر في مجموسنة متوسط ) 50-20( وتتراوح أعمارھم بین %) 53.33( من المرضى اإلناث ) 8(و ) 46.67(% ذكور من المرضى تتراوح أعمارھم بین ) 7( كان ھناك و نوع الجنس ) ct(لم تكن ھنالك فروق بارزة بین زیادة ُعرض النتوء الُمقاسة سریریا و صوریًا ) . 31.88(و في مجموعة اإلناث كانت الفئة العمریة ) 35.43( الذكور .سنة 47٪ في سن ) 4.76(ة عملیة زرع األسنان وفشلت عملیة واحدة فقط بنسب) 20( ٪ في ) 95.24( حققت ھذه الدراسة نسبة نجاح .والسن كما وتكشف ھذه الدراسة أنھ لم یكن . كان ھناك زیادة كبیرة في حجم العظم الفكي الذي زاد في وقت الزرع لیصبح الُعرض كافیا لدعم عملیة الزرع بصورة جمالیة وفَعالة:االستنتاج .ة تولید العظم بمادة العظم اإلصطناعیةھناك أي تأثیر من حیث نوع الجنس والسن على زیادة حجم العظام بعملی zeyneb f.doc j bagh college dentistry vol. 25(4), december 2013 clinical and radiographical pedodontics, orthodontics and preventive dentistry164 clinical and radiographical evaluation of pulpotomy in primary molars treated with pulpotec (pd), formocresol and mineral trioxide aggregate (mta) zeyneb a.a. aldahan, b.d.s., m.sc. (1) abeer m. zwain, b.d.s., m.sc. (2) aseel haidar m. j. al-assadi, b.d.s., m.sc. (3) abstract background: pulpotomy is an accepted treatment for the management of cariously exposed pulps in symptom free primary molars to achieve one of the most important goals for pedodontists, which is the retention of the pulpally involved deciduous teeth healthy until the time of normal exfoliation. the purpose of this study was to evaluate the relative success of pulpotec, formocresol and mineral trioxide aggregate (mta) in cariously exposed primary molar teeth, using clinical and radiographical examinations. materials and methods: thirty nine children with 45 primary molars requiring pulpotomy were selected in this study, 15 teeth treated by each type of pulpotomy medicament. clinical and radiographical follow up for the patients was performed after 1 month, 3 months and 6 months respectively. results: after six months, the clinical success rate of the pulpotec group was (93.3%), formocresol group was (73.3%) and (100%) for the mta group, although the success rate of the formocresol group was the least comparing to the other two groups, it was statistically not significant (p= 0.05). the highest and lowest radio graphical success rates after six months, were encountered in the mta (100%) and formocresol (66.7%) groups respectively, which showed a significant difference (p=0.04). the radiographical success rate of the pulpotec group was (86.7%). conclusion: this study suggests that pulpotec and mta can be used as a replacement for formocresol as a pulpotomy medicament in primary molar teeth. key words: pulpotomy, primary molar, formocresol, pulpotec, mineral trioxide aggregate (mta). (j bagh coll dentistry 2013; 25(4):164-170). introduction pulpotomy is the most common pulp treatment of the primary teeth in children before 6 years of age (1,2), it is indicated in primary molars when the radicular pulp tissue is healthy or is capable of healing after surgical amputation of the affected or infected coronal pulp (3).this treatment has attained wide acceptance clinically and radiologically when pulpal inflammation is confined to coronal pulp (4). the importance lies not only with the choice of procedure but also with the different pharmacotheraputic agents which have been already used (5). the procedure involves coronal pulp amputation and the remaining vital radicular tissue surface is treated with long-term clinically evaluated medicaments to preserve the vitality and function of radicular pulp (6). for many years, formocresol was an acceptable and the most commonly used dressing material for the amputated pulp (7). success rates of pulpotomy with formocresol in primary molars ranged between 70% to 97% (8-10) and declined with time (8, 11, 12). pulpotec (pd) is a radioopaque non resorbable material for simple rapid and long term treatment for pulpotomy of vital molar, the vitality of the (1) professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)assistant professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (3)lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. residual radicular pulp after treatment with pulpotec is undisputable and in many literatures, they confirm the fact that the components of pulpotec, formaldehyde in particular, are not diffused beyond the pulp chamber, but only react at the level of the interface pulpotec/pulp, maintaining the vitality of the underlying radicular pulp, that is the action of formaldehyde stops with the setting of the preparation. the setting time of pd being of about 7 hours, it allows the safeguarding of the vitality of the radicular pulp (13). according to the clinical trials provided, the high efficiency of pd for treatment of odontitis in molars of temporary and permanent teeth by vital amputation method and absence of negative dynamics during 6 months of the observation were ascertained. simplicity in use, absence of pain symptoms during the treatment, decreasing of terms of treatment to two visits, keeping of vital pulp will considered to be advantages of the preparation. positive results of medical trials of pd preparation enable to recommend it for use in extensive clinical practice (14). mineral trioxide aggregate (mta) is a new biocompatible material has been continuously investigated for its ability to seal the pathways of communication between the root canal system and external root surface (5, 15). it is a fine hydrophilic powder developed by mahmoud torabinejad in j bagh college dentistry vol. 25(4), december 2013 clinical and radiographical pedodontics, orthodontics and preventive dentistry165 1993, it composed of tricalcium silicate, tricalcium aluminate, tricalcium oxide, silicate oxide and bismuth oxide (16). mta has been proposed as a potential medicament for pulpotomy procedures as well as capping of the pulp with reversible pulpitis, repair of root perforation and apexification (5), and one of its applications is using the material after coronal pulp amputation in primary molars with carious pulp exposure as a pulp dressing material (5,1517,20). furthermore, mta has superior biocompatibility is less cytotoxic than other materials currently used in pulp therapy (16). the present study is designed to compare the success rate of pd in comparison to conventional pulpotomy procedure (formocresol) and the use of mineral trioxide aggregate mta in pulpotomized primary molar teeth. materials and methods sample forty five primary molars with asymptomatic deep carious lesions selected from healthy children, attending pedodontics and prevention department at college of dentistry, university of baghdad. the collection of the sample started from may 2009 and the follow up period end in may 2011. their ages ranged from 4 to 8 years. full detailed treatment plans were explained to the children's parents and written consents for treatment were obtained prior to the clinical procedures and any patient that could not return for follow up on call was excluded from the study. preoperative periapical radiograph was taken and the selected teeth were assigned randomly to one of three treatment groups: pulpotec (pd), formocresol and mineral trioxide aggregate (mta). fifteen primary molars were selected for each of the three groups. procedure after performing local anesthesia, all teeth were isolated with a rubber dam and dental caries were removed and coronal access of the pulp were obtained by high speed bur with water spray .the entire roof of the pulp chamber was then removed. the coronal pulp was amputated using a slowly revolving round bur #6; the pulp tissue was removed by sharp spoon excavator. the amputated pulp stumps in the three groups were gently pressed by sterilized moistened cotton pellet that is to achieve hemostasis, if the bleeding not stopped, which is an indication of inflamed pulp canal tissue; the tooth was excluded from the study. in the pulpotec group, the treatment was provided in two visits. in the first visit and according to the manufactures' instructions, pulpotomy was performed in the usual way, after removal of the coronal pulp tissue pulpotec liquid was mixed with pulpotec powder (pd, switzerland) and blend to obtain required thick, creamy consistency of the paste, the paste was then inserted into the pulp-chamber with a large sized paste filler. the presence of small quantities of blood does not affect the efficiency of pulpotec; the cavity was air-dried prior to the application of the paste, and then sealed with temporary cement. place a cotton roll between the 2 dental arches and request the patient to bite progressively but firmly, so that the pulpotec paste clings to the walls of the pulp-cavity as well as to the root-canal orifices. setting time of pulpotec is approximately 7 hours. during the second visit approximately 8-10 days later, the treatment was completed by setting the final tight obturation with amalgam, which placed on the pulpotec, possibly leaving a thin intermediary layer of temporary cement to insulate pulpotec from the final obturation material (14). for the formocresol group, a cotton pellet dipped in buckley’s formocresol (pd, switzerland) and squeezed in a piece of cotton was placed in the pulp chamber for 5 minutes. the pulp chamber was then covered with the pulpotomy paste (1drop eugenol, 1 drop formocresol mixed with zinc oxide powder), covered with zinc phosphate cement base, and amalgam filling (15). in the mta group, white mineral trioxide aggregate powder (mtaangelus product) mixed with distilled water, according to the manufacture instructions, and by using amalgam carrier the material was applied over the pulp stumps and condensed by a condenser then covered by a layer of zinc oxide eugenol temporary filling material. after 24 hours, the teeth were restored by amalgam filling (16). all the patients were recalled after 1 month, 3 months and 6 months (17) respectively and evaluated clinically and radio graphically. clinical evaluation: the presence of any signs such as swelling, pain, tenderness to percussion or palpation, sinus tract and pathological mobility was definitely of clinical failure (15). radiographical evaluation: the radiographs were examined carefully and compared with the preoperative radiographs (fig. 1,2,3). observation of any partial loss of the lamina dura, widening of the periodontal ligament, any sign of pathological external or internal root resorption as well as periapical or inter-radicular radiolucency was considered as radiographic failure (16,17). all failed cases were treated by either pulpectomy or extraction of the tooth. j bagh college dentistry vol. 25(4), december 2013 clinical and radiographical pedodontics, orthodontics and preventive dentistry166 statistical analysis was done using the chisquare test at level of significance p<0.05 and ztest (percentage test) to perform comparisons between the groups. results thirty nine patients aged 4-8 years with mean age 6 years (19 males and 20 females) were included in the study from which 45 primary pulpotomies (11 upper and 34 lower) returned for definitive treatment and followed up clinically and radio graphically. for each type of pulpotomy (pulpotec, formocresol and mta), the treatment performed to 15 primary molars (table 1). although the second primary molars were higher in number than the first primary molars 28, 17 respectively, no significant differences observed between types of teeth treated (df =1, x2=3.592, p=0.166) which indicate that the three types of pulpotomy treatment had the same effect on the first as well as the second primary molars. none of the patients in the mta group showed any abnormal clinical findings, however, clinical failure symptoms of post operative swelling were reported with 1/15 in the formocresol group. tenderness to percussion was seen in 1/15 for both pulpotec and formocresol group, while sinus tract was reported only in formocresol group 2/15. pain and pathological mobility were not reported in the entire follow up period. at the end of 6 months, the follow up evaluations clinically revealed that mta group had the highest (100%) and formocresol group had the lowest (73.3%) success rates. at the same time, an (93.3%) success rate was observed in the pulpotec group, however, the differences between the clinical success rates of the three groups pulpotomy were statistically not significant (p=0.05) , while by using z-test a significant differences was found between mta and formocresol group, table 2. radiographical assessment of the treated sample is illustrated in table 3. mta group showed no evidence of radio graphic failure; while in pulpotec group 2/15 showed internal resorption so it succeeded by a rate of 86.7%. on the other hand, the lowest success rate radio graphically was 66.7% for the formocresol group in which periapical and furcation radiolucency was seen in 3/15 and 2/15 of the treated teeth respectively. a significant difference was found statistically between the three groups (p= 0.04). although the radiographic failures were higher than the clinical failures, they were statistically not significant. discussion during this study, the use of pulpotec was easy and simple and that was also mentioned by tairov and melekhov (18). absence of pain at all patients without exception after use of pulpotec was seen. no complaints were lodged by patients either in the intervals between visits to clinic or during the dynamic observation. no swelling of gum in the area of the treated tooth was detected during the given period (6) months, no evidence of a fistula and no mobility of a tooth, this also was found in the results of the clinical trials provided by dedeyan and donkaya (14). clinically, the success rate of pulpotec obtained in this study was 93.3%. pulpotec (pd) composed of powder (polyoxymethylene, iodoform, and zinc) and liquid (dexamethasone acetate, formaldehyde, phenol, guaiacol, and subsidiary substances). the addition of pharmacological constituents ensures an aseptic treatment, induces cicatrization of the pulpal stump at the chamber-canal interface, whilst maintaining the structure of the underlying pulp, and also avoids the numerous failures that have been noted with total pulpectomy (13). pulpotec showed antibacterial activity against s. aureus, e.faecalis, and e. coli, this result is probably due to the toxicogenic components in its composition (iodoform and formaldehyde) (19) . the clinical success rate in formocresol group was 73.3% which was near to that obtained by zwain (20) who reported 75% success rate and noorollahian (21) who reported 66% success rate. formocresol is the most common material used in primary teeth with traumatic or mechanical exposure of coronal pulp (22) as the material has antiseptic and fixative qualities (23) but in the other hand, it is toxic and potentially carcinogenic material(24,25), while mta was less cytotoxic, non mutagenic(26), prevent microleakage and it is a biocompatbile dental material. its biological properties may be due to its excellent sealing ability (27), high alkalinity (28), and induction of hard tissue formation (29), antibacterial effect (30), and stimulation of healing in the pulpal tissue (31, 32). at the end of 6 months follow up, it was interested to note that the clinical success rate was 100% in the mta group and this rate was obtained in other studies (5,17,33-35), while other studies showed this rate as 97% (15) and 86.7% (20) . in the present study, clinical failure symptoms were swelling, tender to percussion and sinus tract which were reported in the formocresol group. these symptoms were also noted in previous studies (4, 20,22). while for pulpotec group, the only case failed was that showed tenderness to j bagh college dentistry vol. 25(4), december 2013 clinical and radiographical pedodontics, orthodontics and preventive dentistry167 percussion. these symptoms may be attributed to chronic inflammation of pulp. surprisingly, in the present study the radiographic success rate was drastically reduced in comparison with the clinical success rate in the pulpotec and formocresol groups. this result is in accordance with other studies (4,21,34). in the pulpotec group, it was 86.7% (two teeth showed internal resorption) , this may be due to inflammatory cells attracted to the area as a result of placement of irritating capping material over the pulp tissue (presence of dexamethasone acetate, formaldehyde ) which might well attract the osteoclastic cells and initiate the internal resorption . however, in the formocresol group, the success rate was 66.7% and compared to other studies this rate presented as: 68.75% (20), 67.75 % (36), 62% (21) and 56.7% (4). failure of pulpotomy is normally detected radiographically, as the tooth may be asymptomatic clinically. the first sign of failure may be internal resorption of the root adjacent to the pulpal medicament. this may be accompanied by external root resorption, especially as the failure progresses. in primary molars, pathological interradicular radiolucency develops in the bifurcation or trifurcation area; in anterior teeth radiolucency may develop at the apex or laterals to the root. with more destruction, the tooth becomes mobile or a fistula may develop (37). in the present study, after 6 months, in the formocresol group, three teeth showed periapical radiolucency and two other teeth showed furcal radiolucency. these findings of failure have also been reported in various previous studies (4,16,20,22,34,36,38). the pathological radiolucency in the formocresol group may have been due to the smaller molecular size of formocresol, which may cause seepage into the apical region through the pulpal canal(s) or into the furcation area via accessory canals or the pulpal floor, as it is thin, porous and permeable in nature, in deciduous molars (39,40). in addition formocresol even in reduced concentrations has the potential to result in negative immunologic, systemic, toxicological, and overt clinical consequences. more specifically formaldehyde employed during pulpotomy could evoke inflammation of surrounding non-target tissue and exert cytotoxic (41-44), genotoxic and mutagenic effects (45,46) leading to tissue damage ranging from vascular insult and inflammation (4749) to necrotic (50,51) and osteolytic changes (52).it is also capable of damaging the enamel and the succedaneum teeth (53). after 6 months, the mta group was free from any pathological findings and its radiographic success rate was 100%, so as in other studies (17,3234) and this may be due to its excellent sealing ability, biocompatibility and ability to regenerate hard tissues (54-56). based on the data of the current study, although the clinical success rates varied between pulpotec, formocresol and mta , it was statistically not significant, however, statistical significant differences was found concerning the radiographical success rates between the three groups. pulpotec and mta produce more favorable outcomes; it seems that the potential use of these materials could successfully eliminate side effects associated with formocresol in pulpotomy procedure for primary teeth. references 1. curzon mej, roberts jf, kennedy db. kennedy’s paediatric operative dentistry. 4th ed. oxford: wright; 1996. p. 15-18, 159-161. 2. bricevic h, al-jame q. ferric sulfate as pulpotomy agent in primary teeth: twenty month clinical follow up. j clin pediatr dent 2000; 24: 269-72. 3. holan g, fuks ab, keltz n. success rate of formocresol pulpotomy in primary molars restored with stainless steel crown vs amalgam. pediatr dent 2002; 24(3): 212-6. 4. havale r, anegundi rt, indushekar kr, sudha p. clinical and radiographic evaluation of pulpotomies in primary molars with formocresol, glutaraldehyde and ferric sulphate. ohdm 2013; 12(1): 24-31. 5. hugar sm, deshpande sd. comparative investigation of clinical/ 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(ivsl). 23. damle sg. text book of pediatric dentistry. 3rd ed. arya (medi) publishing house; 2009. pp. 341. 24. myers dr, pashley dh, whitford gm. the acute toxicity of high doses of systemically administered formocresol in dogs. pediatr dent 1981; 3: 37-41. 25. myers dr, pashley dh, whitford gm. tissue changes induced by absorption of formocresol from pulpotomy sites in dogs. pediat dent 1983; 5: 6-8. 26. torabinejad m, pitt ford tr, abed hr, kariyawasan sp, tang hm. tissue reaction to implanted root end filling materials in the tibia and mandible of ginea pigs. j endod 1998; 24: 468-71. 27. wu mk, kontakiotis eg, wesselink pr. long-term seal provided by some root-end filling materials. j endod 1998; 24: 557-60. 28. tziafas d, pantelidou o, alvanou a, belibasakis g, papadimitriou s. the dentinogenic effect of mineral trioxide aggregate (mta) in short-term capping experiments. int endod j 2002; 35: 245-54. 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(ivsl). 39. zhang l, steinmaus c, eastmand d, xin x, smith m. formaldehyde exposure and leukemia: a new metaanalysis and potential mechanisms. mutational res 2009; 681:150-68. 40. ringelstein d, kimseow w. the prevalence of furcation foramina in primary molars. pediatr dent 1989; 11:198-202. 41. hill sd, berry cw, seale ns, kaga m. comparison of antimicrobial and cytotoxic effects of glutaraldehyde and formocresol. oral surg oral med oral pathol 1991; 71(1):89-95. 42. jeng hw, feigal rj, messer hh. comparison of the cytotoxicity of formocresol, formaldehyde, cresol, and glutaraldehyde using human pulp fibroblast cultures. pediatr dent 1987; 9(4): 295300. 43. ozaki t. cytotoxicity of formocresol on cultured mammalian cells. shigaku 1988; 75(6):102738. 44. wang xl, song m, lou jn, niu xy. the study of cytotoxicity of different intracanal medications and cell rehabilitation on human periodontal ligament fibroblasts. shanghai kou qiang yi xue 2007; 16(5): 512-9. 45. ribeiro da. do endodontic compounds induce genetic damage? a comprehensive review. oral surg oral med oral pathol oral radiol endod 2008; 105(2): 251-6. 46. gahyva sm, siqueira jf jr. direct genotoxicity and mutagenicity of endodontic substances and materials as evaluated by two prokaryotic test systems. j appl oral sci 2005; 13(4): 387-92. 47. fuks ab. current concepts in vital primary pulp therapy. eur j paediatr dent 2002; 3(3):115-20. 48. fuks ab. vital pulp therapy with new materials for primary teeth: new directions and treatment perspectives. pediatr dent 2008; 30(3):211-9. 49. huang th, yang cc, ding sj, yeng m, kao ct, chou my. inflammatory cytokines reaction elicited by root-end filling materials. j biomed mater res b appl biomater 2005; 73(1):123-8. 50. cardoso ml, todaro js, aguirre mv, juaristi ja, brandan nc. morphological and biochemical changes during formocresol induced cell death in murine j bagh college dentistry vol. 25(4), december 2013 clinical and radiographical pedodontics, orthodontics and preventive dentistry169 peritoneal macrophages: apoptotic and necrotic features. cell biol toxicol 2010; 26(5): 445–55. 51. rolling i, thylstrup a. a 3-year follow-up study of pulpotomized primary molars treated with the formocresol technique. scand j dent res 1975; 83(2):47–53. 52. block r. are you still using formocresol? an update. j tenn dent assoc 2009; 89(4):14-7. 53. jeng hw, feigal rj, messer hh. comparison of the cytotoxicity of formocresol, formaldehyde, cresol, and glutaraldehyde using human pulp fibroblast cultures. pediatr dent 1987; 9(4):295300. 54. torabinejad m, chivian n. clinical applications of mineral trioxide aggregate. j endo 1999; 25:197205. 55. vij raj, coll ja, sheltonp, farooq ns. caries control and other variables associated with success of primary molar vital pulp therapy, pediatr dent 2004; 26: 21014. 56. salako n, joseph b, ritwik p, salonen j, john p, junaid ta. comparison of bioactive glass, mineral trioxide aggregate, ferric sulfate and formocresol as pulpotomy agents in rat molar. dent traumatol 2003; 19:314-20. table 1: distribution of the sample by type of teeth and type of treatment. type of treatment no. of children no. of teeth maxillary 1st molars maxillary 2nd molars mandibular 1st molars mandibular 2nd molars males females total right left right left right left right left pulpotec group 6 7 13 15 1 1 2 3 2 2 2 2 formocresol group 3 10 13 15 0 2 0 0 6 0 5 2 mta group 10 3 13 15 1 0 0 1 1 1 5 6 total 19 20 39 45 5 6 12 22 table 2: clinical assessment of the three groups pulpotomized teeth after 6-months follow up. pulpotomy groups clinical findings total clinical success p sw t.p s.t p.m f s f s f s f s f s f s no. % pulpotec _ 15 _ 15 1 14 _ 15 _ 15 1 14 14 93.3 formocresol _ 15 1 14 1 14 2 13 _ 15 4 11 11 73.3 mta _ 15 _ 15 _ 15 _ 15 _ 15 _ 15 15 100 pulpotec/fc/mta x2=5.85 p=0.05* z-test pulpotec/formocresol z=1.4697 p=0.14156 n.s. pulpotec/mta z=1.0171 p=0.307 n.s. mta/formocresol z=2.1483 p=0.03156 sig.** p: pain; sw: swelling; t.p: tenderness to percussion; s.t: sinus tract; p.m: pathological mobility; f: failure; s: success; fc: formocresol *statistically not significant ** statistically significant table 3: radiographical findings of the three groups pulpotomized teeth after 6-months follow up. pulpotomy groups radio graphical findings total radio graphical success er ir plild wpdl pr fr f s f s f s f s f s f s f s no. % pulpotec _ 15 2 13 _ 15 _ 15 _ 15 _ 15 2 13 13 86.7 formocresol _ 15 _ 15 _ 15 _ 15 3 12 2 13 5 10 10 66.7 mta _ 15 _ 15 _ 15 _ 15 _ 15 _ 15 _ 15 15 100 pulpotec/fc/mta x2=6.429 p=0.04** z-test pulpotec/formocresol z= -1.295 p=0.197 n.s. pulpotec/mta z=1.4639 p=0.1443 n.s. mta/formocresol z=2.4495 p=0.01428 sig.** er: external resorption; ir: internal resorption; plild: partial loss of integrity of lamina dura; wpdl: widening of periodontal ligament; pr: periapical radiolucency; fr: furcal radiolucency f: failure; s: success; ** statistically significant. j bagh college dentistry vol. 25(4), december 2013 clinical and radiographical pedodontics, orthodontics and preventive dentistry170 fig. 1: (a, b, c) illustrates the follow up of an 8 year old girl. fig. 2: (a, b, c) illustrates the follow up of a 6 year old boy. fig. 3: (a, b) illustrates the follow up of an 8 year old boy. (a) diagnostic x-ray lower right 2nd primary molar (b) conventional pulpotomy treatment lower right 2nd primary molar (c) last visit lower right 2nd primary molar (a)diagnostic x-ray lower left 2nd primary molar (b) pulpotomy treatment with mta in lower left 2nd primary molar (c) follow up after one year period (a) diagnostic x-ray lower right 1st and 2nd primary molars (b) follow up after pulpotomy treatment with pulpotec for the 1st primary molar and formocresol for the 2nd primary molar resha f.doc j bagh college dentistry vol. 25(4), december 2013 postoperative assessment oral diagnosis 52 postoperative assessment of dental implants by using multi-slice computed tomography resha j. al-sudani, b.d.s. (1) lamia al-nakib, b.d.s., m.sc. (2) shifaa h. al-naimi, b.d.s., h.d.d., m.sc. (3) abstract background: implantology is a fast growing area in dentistry. one of the most common issues encountered in dental implantation procedures is the lack of adequate preoperative planning. conventional radiography may not be able to assess the true regional three-dimensional anatomical presentation. multi slice computed tomography provides data in 3-dimentional format offering information on craniofacial anatomy for diagnosis; this technology enables the virtual placement of implant in a 3-dimensional model of the patient jaw (dental planning). patients, material and methods: the sample consisted of (72) iraqi patients indicated for dental implant (34 male and 38 female), age range between (20-70) years old. they were examined during a time period started from december 2012 to april 2013. all the patients who subjected to implant treatment depending on the pre-operative panoramic radiograph were referred al-kharkh general hospital, spiral ct scan department, for postsurgical assessment evaluate the angulation of fixture in relation to the angulation of bone in coronal and sagittal sections by using multi-detector computed tomography. results: the present study showed that the angulation of implant affected by age, sector, and tooth position in the same jaw, and not affected by gender. conclusion: multi-slice computed tomography provides a great understanding about bone angulation, it necessary as a diagnostic tool for treatment planning pre and post-operatively. key words: dental implants, multi-slice computed tomography. (j bagh coll dentistry 2013; 25(4):52-55). introduction dental implant is a surgical devices which replaces the lost roots of tooth to which an artificial tooth or complete denture can be attached (1) the replacement of missing teeth with ossteointegrated implants has proven to be a reliable alternative to other fixed and removable prosthesis devices. in most clinical situations it produces predictable and satisfactory treatment results (2) the success of dental implant treatment depends on careful preoperative planning by obtaining information regarding the angulation, quality, and quantity of the bone at a potential implant site and determines the relationship of the proposed implant to anatomical structures at the implant site (3) panoramic radiography is readily available and provides a view of many structures in maxilla and mandible at a low cost. however, image magnification and lack of cross-sectional information are the main disadvantages of this image modality (4) multi-slice computed tomography provides data in 3-dimentional format offering information on craniofacial anatomy (5) (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. (3) oral and maxillofacial radiologist, al-karkh general hospital, ministry of health. bone angulation is the fourth determinant for available bone. the initial alveolar bone angulation represents the natural tooth root trajectory in relation to the occlusal plane. ideally, the angle formed between the long axis of the bone with the long axis of implants should be less than 20 degree (6) patients, materials and methods the sample consisted of (72) iraqi patients indicated for dental implant (34 males and 38 females), age range between (20-70) years old. they were examined during a time period started from december 2012 to april 2013. the total sample was attended to different center of implantology in baghdad, and they subjected to clinical examination, panoramic radiographical evaluation, and treatment planning. all the patients who subjected to implant treatment were referred to al-kharkh general hospital, spiral ct scan department, for postsurgical assessment by using multi-detector computed tomography. several cases were excluded such as: severe bone atrophy of maxilla and mandible that need bone graft surgery, cases need surgery of active sinus lift in maxilla, cases need surgery of mandibular canal transposition in mandible, cases of previous bone graft with bone manipulate. the 1st measurement was done preoperatively directly on the opg by using digital caliper. the j bagh college dentistry vol. 25(4), december 2013 postoperative assessment oral diagnosis 53 2nd measurement was done post operatively directly on the ct scan by using its own software, within the 1st month after dental implant and detected the angulation of each implant in comparable with angulation of bone in sagittal and coronal section, by measuring the long axis of bone with long axis of the implant it should be less than 20 degree. results factors associated with improper angulation of dental implant 1. age group it was found that the age group (≤35 years old) show the highest percentage in improper angulation of the dental implant among the other two groups (70.7 %), and the age group (+50 years old) show percentage about (55.6%) in improper angulation of the dental implant, and (36.5%) for age between (36-49) years old. (table 1), figure (1) a 2. gender it was found that there was no gender effect in the incidence of improper angulation. (table 1), figure (1) a 3. maxilla vs mandible it was founded that there were no significant differences between maxilla and mandible in improper angulation of dental implant. (table 1)figure (1) b 4. jaw sector it was founded that there were significant differences in improper angulation according to the jaw sector, in anterior area with more improper angulation chance to occur (65%) than premolar sector (60%) and in molar sector (32.5%). (table 1), figure (1) b 5. area of implant\ tooth position it was found that there were significant differences in improper angulation related to tooth area in the jaw. (table 1), figure (1) b improper angulation in lateral incisor was the highest (91.7%) and in the first molar was with lowest percentage (27.3%), while there was no significant difference in canine area. (table 1), figure (1) b disscusion the present study was conducted to evaluate the accuracy of panoramic radiography as diagnostic radiograph in dental implant treatment. factors associated with improper angulation of dental implant 1. age group the present study showed that the improper position of implant increased with young age (35) years old, and with old age (+50) years old, so the rate of success increase with age range from (35-49) years old. heij et al (7) reported that jaw growth can compromise oral implants and questioned the minimum age of a patient for implant treatment. salonen et al (8) stated that advanced age was a possible contributing factor to implant failure. 2. gender the present study showed no relation between rate of success of implant and gender. this study was agreed with weyant (9), in the rate success of implant not depend on the patient sex. this study was disagreed with ekfeldt et al (10), where identified that female has more risk for implant failure due to low bone density which decrease the success rate 3. maxilla vs. mandible the present study showed no significant differences between the implant angulation and the jaw. this study was disagreed with adell et al (11) and van steenberghe (12) who found that implants placed in the maxillary molar area was lost as compared with implants placed in the mandibular molar region. jaffin and berman (13) reported the loss of implants inserted in the maxillae, generally, mandibular implants also survive longer than maxillary implants. 4. jaw sector the present study showed that there was a relationship between the area and the improper angulation, which increase in anterior area and decrease posteriorly. this study was in agreement with baqain et al (14), when stated that the implants placed in the anterior maxilla and anterior mandible had high risk factor of failure. in addition, it was in agreement with van steenberghe et al (12) who stated that the implants failure depends on the area. 5. tooth or implant position the present study showed there was a relationship between implant position and improper angulation, high significant improper position in lateral incisor and lowest in the first molar, while there was no significant differences in canine area. this study was in agreement with van steenberghe et al (12) who stated that the implants failure depends on the implant position. also agreed with jaffin and berman (13) who reported the success rate increase in lower posterior area and decrease in upper posterior area. as conclusions; (1) computerized tomography provides crosssectional radiographic images that facilitate proper assessment of potential recipient sites for implant placement. j bagh college dentistry vol. 25(4), december 2013 postoperative assessment oral diagnosis 54 (2) bucco-lingual angulations of bone is an important dimension that should be measured before implant placement, and play an important role to determine the path of implant insertion, therefore it could determine the success or failure rate of implant, and it is cannot be measured by plane radiograph, computerized tomography provides crosssectional radiographic images that facilitate the measurements of bone dimensions. (3) the age of the patient had a significant relation with the dimensions of bone, while gender had no significant relation with bone measurements. (4) there was significant relation between the jaw and the bucco-lingual direction. refferences 1. lemons j, natiella j. biomaterials, biocompatibility and peri implant consideration. dental clin north am 1986; 30: 43-51. 2. brown s. dental implantsnew horizones in the diagnosis and treatment planning. periodontics and implant dentistry, periodontal letter, philadelphia, pa 2004; 19102,(215):735-3660. 3. harris d, buser d, dula k, grondahl k, jabcobs r, lekholm u, nakielny r, vander stelt p.e.a.o. :guidelines for the use of diagnostic imaging in implant dentistry. a consensus workshop organized by the european association for ossteointegration in trinty college dublin. clin oral implants res 2002; 13(5): 566-570. 4. sakakur a ce, morais ja, leffredo lc, scaf g. a survey or radiographic prescription in dental implant assessment. the british institute radiology. dentomaxillofacial radiology 2003; 32(6): 397-400. 5. zhejiang univsci b. assessment of volumetric bone mineral density of the neck with and without vertebral fractures using quantitative multi-slice ct 2009; 10(7): 499–504. 6. lam rv. contour changes of the alveolar process following extraction. j prosthet dent 1960; 10: 25-32. 7. heij dg, opdebeeck h, van steenberghe d, quirynen m. age as compromising factor for implant insertion. periodontology 2003; 33:172-84. 8. salonen ma, oikarinen k, virtanen k, pernu h. failures in the osseointegration of endosseous implants. international journal of oral and maxillofacial implants 1993; 8: 92-7. 9. weyant rj. characteristics associated with the loss and peri-implant tissue health of endosseous dental implants. international journal of oral and maxillofacial implants 1994; 9: 95-102. 10. ekfeldt a, christiansson u, eriksson t, lindén u, lundqvist s, rundcrantz t, johansson la, nilner k billström c. a retrospective analysis of factors associated with multiple implant failures in maxillae. clinical oral implants research 2001; 12: 462-7. 11. adell r, lekholm u, rockler b, et al. a 15-year study of osseointegrated implants in the treatment of the edentulous jaw. int j oral surg 1988; 6: 387-416. 12. van steenberghe d, quirynen m, collbersson l, demanet m. a prospective evaluation of 697 consecutive intra oral fixture and modem branemor in the rehabilitation of edentulism. j head neck pathology 1987; 53-8. 13. jaffin ra, berman cl. the excessive loss of branemark fixtures in type iv bone: a 5-year analysis. journal of periodontology 1991; 62: 2-4. 14. baqain zaid h, moqbel wael yousef, sawair faleh a. early implant failure. oral and maxillofacial surgery department, university of jordan hospital, br j oral maxillofac surg, 2011. table 1: effect of different factors associated with improper angulation total n improper angulation n % p age group(years) 0.004 -35 41 29 70.7 36-49 52 19 36.5 +50 27 15 55.6 gender 0.58(ns) female 60 33 55.0 male 60 30 50.0 maxilla vs. mandible 0.58(ns) maxilla 60 33 55.0 mandible 60 30 50.0 jaw sector 0.007 anterior area 40 26 65.0 premolar area 40 24 60.0 posterior area 40 13 32.5 tooth position 0.001 central incisor 22 15 68.2 lateral incisor 12 11 91.7 canine 6 0 0.0 1st premolar 21 11 52.4 2nd premolar 19 13 86.4 1st molar 22 6 27.3 2nd molar 18 7 38.9 j bagh college dentistry vol. 25(4), december 2013 postoperative assessment oral diagnosis 55 aage and gender b-tooth area figure 1: effect of different factors associated with improper angulation j bagh college dentistry vol. 29(3), september 2017 an analysis of the 93 oral and maxillofacial surgery and periodontics an analysis of the efficacy of platelet-rich plasma injections on the treatment of internal derangement of a temporomandibular joint waleed kh. ismael, b.d.s., fibms. (1) thair abdul lateef, b.d.s., h.d.d., fibms. (2) muhannad kareem shumran, b.d.s. (3) abstract background: a temporomandibular joint (tmj) internal derangement (tmjid) is a disruption within the internal aspects of the tmj in which the disc is displaced from its normal functional relationship with the mandibular condyle, after which the articular portion of the temporal bone causes joint dysfunction, joint sound, malocclusion, and locking of the mouth. conservative and invasive techniques can be used for the treatment of tmjid. a platelet-rich plasma (prp) injection is a simple, less invasive surgical procedure for the treatment of internal derangement. the objective of this study was to evaluate the efficacy of prp injections in decreasing or eliminating pain, clicking, and limitation of mouth opening in patients with tmjid after they were proven to be unresponsive to conservative treatments. the aim is to also show more predictable clinical results. methods: the study involved 70 patients between 19 and 46 years-old, 62 of which were female and 8 of which were male (female to male ratio 7:75).there were a total of 140 joints with anterior disc dislocation with reduction, as confirmed by magnetic resonance imaging (mri). prp was injected in the tmj in the superior joint space. pain intensity, maximal interincisal opening, and tmj sounds were assessed and compared for evaluation of treatment success. results: there was a statistically significant reduction in pain intensity and joint sound and an increase in mouth opening. conclusions: this study shows that intra-articular prp injection for the treatment of anterior disc displacement with reduction of the tmj is a more effective method to reduce pain intensity and joint sound as well as increasing the patient’s mouth opening range. (j bagh coll dentistry 2017; 29(3):39-44) introduction temporomandibular disorder (tmd) describes a set of musculoskeletal troubles in the masticatory system and is the major cause of non-dental originated pain in the oro-facial area which includes the head, face and associated structures. the etiology of tmd has not been yet determined by occlusion, temporomandibular joint (tmj) anatomy, functional and psychological factors can be concerned. internal derangement of the tmj is one of the most common types of tmd, referring to an unusual position of the articular disk in relation with the mandibular condyle and the articular eminence of the temporal bone. (1) the main goal of the treatment for tmjid is to raise the range of motion and decrease the functional pain of the tmj. (2) a lot of nonoperative approaches have been made over the years, including occlusal splint therapy, self-care and medication. conservative management is suggested for internal derangement. surgical interventions include arthrocentesis, arthroscopy, disc repositioning, or discectomy for patients with resistant internal derangement. (3) (1) consultant maxillofacial surgeon, department of maxillofacial surgery , al-yarmuk teaching hospital , baghdad, iraq. (2) assist. prof, department of oral and maxillofacial surgery , college of dentistry , university of baghdad (3) b.d.s, department of maxillofacial surgery , al-yarmuk teaching hospital , baghdad, iraq. intra-articular administration of medications is a well-known management method in orthopedic and rheumatic disorders related to pain, effusion, inflammation of cartilage, bone and joint capsules and fibrous adhesions. at this time, agents used for intra-articular injection inside the tmj area include hyaluronic acid (ha) and steroids. the rationale for the use of ha in the treatment of tmjid is that the direct injection of ha into the joint allows for acquisition of proper concentrations with smaller doses favoring superior permanence in the joint. for that reason, ha preparations have short half-lives therefore; the long-term effects cannot be solely attributed to the substitution of the molecule itself. the term ‘‘viscosupplementation’’ indicates the restoration of viscoelastic properties, such as cushioning, lubrication, and elasticity.(4) the term ‘‘biosupplementation’’ is used to indicate the restoration of joint rheology, antiinflammatory and anti-nociceptive effects, the normalization of endogenous ha synthesis, and chondroprotection. these activities explain why the clinical efficacy is maintained for several months. orthobiologics is a method for increasing of rate of bone and soft tissue healing through the application of natural materials from biological sources. (5) j bagh college dentistry vol. 29(3), september 2017 an analysis of the 04 oral and maxillofacial surgery and periodontics platelet rich plasma (prp) is a new therapeutic agent that has several prospective advantages over corticosteroids in the treatment of the tmjid; prp has been shown to exhibit anti-inflammatory, analgesic, and antibacterial properties. prp also restores intra-articular ha, increases glycosaminoglycan chondrocyte synthesis, balances joint angiogenesis, and provides a scaffold for stem cell migration. basic science studies have indicated that prp stimulates cell proliferation and the production of cartilage matrices by chondrocytes and bone marrowderived mesenchymal stromal cells and increases the production of ha by synoviocytes. the results of using prp to facilitate the repair of chondral and osteochondral defects have had mixed success, with clinical studies indicating that prp bone marrow–derived stromal cell constructs aid in the repair of chondral defects. additionally, prp has also been shown to be maintained 1 year after intra-articular injection in patients experiencing knee pain. furthermore, prp therapy provides the delivery of a highly concentrated cocktail of growth factors to accelerate healing. a transforming growth factor (tgf) is present in prp and has been associated with chondrogenesis during cartilage repair.(6) in this study, we hypothesized that prp would improve the symptoms and function of tmjid, possibly through the release of growth factors and bioactive molecules. materials and methods patients a prospective study with a 6 month follow-up period was designed. patients were educated about the study and provided verbal consent. the study included 70 patients who had anterior disc displacement with reduction causing functional disability, pain, limitation in mouth opening, and clicking. these patients had no prior success in tmjid treatment using conservative treatments. the study took place between november 2014 and october 2015 . an mri was used to evaluate the extent of tmjid. patients who had central perforation of an articular disc, advanced arthrofibrosis, or ankylosing osteoarthritis, subjects who had any previous surgery, poor overall health, unwillingness to participate, numerous dental defects. patients with disc displacement without reduction, diagnosis of inflammatory or a connective tissue disease, contra-indications associated with the use of prp, (platelet function disorders, fibrinogen deficiency, and anticoagulation treatment), thrombocytopenia, malignant disease in the head and neck region, infection of the affected joint, injection of sodium hyaluronate or corticosteroids into the target tmj during previous 6 months ,and pregnant and lactating lady were excluded from this study. the patient's age, gender, previous treatments, pain, joint sound, and the extent of mouth opening were recorded. prp injection was applied to the patients’ joints. pain was evaluated on a visual analog scale (vas) from 0 (no pain) to 10 (worst pain). induction of a pathologic noise with joint movement was assessed with a stethoscope placed over bilateral tmjs. maximal mouth opening was recorded (mm). all assessments were repeated by the same physician 1 month, 3 months, and 6 months after the prp injection. preparation of prp rpr was prepared by a sample of 10 ml of blood and is collected from every patient in 10 ml vacuum tubes containing 1ml of 10% sodium citrate for anticoagulation (figure 1). the tubes are centrifuged at 1200 rpm for 10 min at room temperature, enabling the separation of three components (figure 1): red cells (bottom of the tube), white cells (thin layer on top of the red cells) and plasma (top layer) then the plasma is decanted into a new sterile 10 ml tube and is centrifuged again in the same machine at the same speed for five minutes. at the stop of this centrifugation (figure 1), the upper plasma layer that is obtained (accounting for approximately 50%) was discarded because of the small quantity of platelets. the lower portion, which is rich in platelet sand, is the prp (figure 1). (9) figure 1: (a) illustrates the separation of plasma from erythrocyte. (b) illustrates prp and ppp. (c) illustrates prp. operative technique intra-articular injections of prp were preceded by collection of peripheral blood from the ulnar vein of the patient using a double centrifuge, using vacuums tubes with sodium citrate as an j bagh college dentistry vol. 29(3), september 2017 an analysis of the 04 oral and maxillofacial surgery and periodontics anticoagulant. the patient was seated at a 45º incline with their head turned contralaterally to provide a simple approach for the joint to be managed. the procedure was carried in aseptic conditions, the ear and pre-auricular skin above the tmj was prepared and draped with topical antiseptic solution, a line was drawn from the lateral canthus to the most posterior and central point on the tragus (holmlund–hellsing line) (figure 2). (7) the posterior point of entry is located along the canthotragal line 10 mm from the middle of the tragus and 2 mm below the canthotragal line. this is the approximate area of the maximum concavity of the glenoid fossa. the distance is about 25 mm from skin to the center of the joint space, (10) the point of entry is placed 10 mm further along the canthotragal line and 2 mm below it. the auriculotemporal nerve was blocked with about 2 ml of local anesthetic, which was first injected into the joint cavity to relax this virtual space. subsequently, the needle was gently withdrawn to the skin surface to also anesthetize the soft tissues over the joint (figure 4) and a 21gauge needle was used for introduction into the superior joint space at the glenoid fossa approximately 0.5 ml of prp was injected to distend the superior joint space (figure 3). the skin was disinfected once again after the injection. figure 2: illustrates the preparation of patient and points on the canthotragal line. figure 3: illustrates the procedure for prp injection. figure 4: illustrates injection of local anesthesia in tmj the prp was injected into the joint without activating calcium chloride and thrombin because it has been shown that non-activated prp can enhance mesenchymal stem cell proliferation, chondrogenic differentiation, and osteoinductivity.(8) statistical analysis data collected from a clinical follow-up was analyzed using a statistical package for social sciences (spss) software and excel (vers. 21) for tables and figures involving descriptive statistics, inferential statistics (paired sample t test to assess the reliability of data. a p-value of <0.05 was considered significant; if the p-value was <0.01, then it was considered highly significant. a pvalue of >0.05 was considered insignificant. results no important complications were reported. patients experienced short-term swelling and soreness above the tmj for the first day following procedures. a total of 140 joints in 70 patients (62females, 8 males) were included in the study group. mean age of the patients was 31.5 years. j bagh college dentistry vol. 29(3), september 2017 an analysis of the 04 oral and maxillofacial surgery and periodontics all patients in this study were treated with one dose prp (0.5 ml) intra-articularly. the differences in pain scores (vas) between preand post-injection were statistically significant (p < 0.05) (table 1). the most intense distinction was between pre-injection and 6 months after injection (6.528, p<0.01, hs). the mean of maximum mouth opening pre-injection 32 and 6 months post-injection 39.27 mmo (table 2). the difference in mmo between preand postinjection at 6 months was statistically significant. seventy joints had pathologic sounds at first examination; 6 months after treatment, only two joints had a pathologic sound (p < 0.05) (table 3). table 1: vas results preoperative post-operative 1 month post-operative 3 month post-operative 6 month vas vas vas vas mean 8.142 3.157 1.942 1.614 sd 1.195 1.519 0.866 1.561 anova f=3.69.9 p<0.01 hs *high significant table 2: maximum mouth opening results pre-operative post-operative 1 month post-operative 3 month post-operative 6 month mio mio mio mio mean 32 37.21 38.21 39.27 sd 1.922 2.369 1.971 1.647 anova f=59.133 p<0.01 hs *high significant table 3: joint clicking results. bilateral pre-operative post-operative 1 month post-operative 3 months post-operative 6 month clicking clicking clicking clicking yes 70 6 4 2 no 0 64 66 68 chi-square 156.8 p-value p<0.01 sig hs * high significant r=0.906 discussion age distribution in this study, the mean age was 31.5 years old and the range was between 19 and46 years-old with maximum age group ranging from (30-39) years. this could be explaining why certain age groups have a greater risk for developing tmj than others. these results are in agreement with edmond et al (11) and blasberg and greenberg et al (12). the increase could also be due to social tensions among this age group. sex distribution in this study, there is an evidence of a high predilection of tmj among females, with a female to male ratio of 7:75. this can is supported by studies suggesting that females suffer higher levels of pain and dysfunction, and have a greater persistence of symptoms over a longer time, such as the results in steven et al, which showed functional estrogen receptors have been identified in the female tmj but not in the male tmj. estrogen may also promote degenerative changes in the tmj by increasing the synthesis of specific cytokines, whereas testosterone may inhibit these cytokines. (13) all patients had improvement in symptoms related to the intra-articular derangement and increased mandibular movements. results are in agreements with studies done by m hancı et al and lippross et al. (14) females suffering more problems than male due to divorce and marital status may indirectly lead to tmjid. j bagh college dentistry vol. 29(3), september 2017 an analysis of the 09 oral and maxillofacial surgery and periodontics parameters and data the efficacy of prp injections in tmjid in this study was based on 3 clinical parameters: reduction in pain, absence of clicking during function, and an increase in maximum mandibular movements. many researchers and clinicians have reported similarly positive results from prp treatment. pain at the first follow-up visit, the mean pain score reduced from 8.1 to 3.1 for all patients. at the second follow-up visit, the mean pain score reduced to 1.9 for all patients. at the third followup visit, the mean pain score reduced to 1.6 for all patients. the data elicited from (avs) showed an overall significant reduction in pain from 8.1 to 1.6 (p<0.01hs). these results are in agreement with the m. hancı et al study, wherein the researchers described a decrease in pain in tmjid in 10 cases of patients treated with prp. (15) it is known that tmj dysfunction is related to alterations in joint intra-articular pressure and biochemical components of the synovial fluid rather than to the change in cases disc position in the case of disc displacement of tmjid. (13) the analgesic effect of prp has been highlighted in lee et al, where results pointed to an augmentation of the cannabinoid receptors cb1 and cb2; this might be related to the analgesic effects of prp. (16) our results were also in agreement with other studies. (8) (11) maximum mouth opening the study data elicited significant improvement in the mmo of patients (p value < 0.01, with success rate 100%).these results are in agreement with previous studies (17) (8) like lippross et al., where researchers found that prp reduced the levels of all markers related to the inflammation of tmj; intra-articular injection of prp helped to maintain the integrity of the chondral surface and thereby facilitated joint movement.(18) joint clicking in this study, all patients were suffering from tmj clicking. at the first follow-up visit, 64 patients (91.4%) showed a significant disappearance of tmj clicking; at the second and third follow-up visits, 4 more patients (5.7%) showed a significant disappearance of tmj clicking, meaning that by the final follow-up session, there was significant tmj clicking sound disappearance in 68 patients (97.14%, p < 0.01). from a total of 70 patients, only 2 patients (2.8%) showed no improvement in joint clicking. prp can support the maintenance of a hyaline-like phenotype, chondrocyte proliferation, and proteoglycan production and it can promote many other bioactive molecules concerned in regeneration. in this study the success rate of rpr injection for joint clicking was in line with study that was performed by songeul et al. (8) conclusion 1-intra-articular prp injection is a therapeutic approach that may be an excellent substitute for the management of unmanageable tmjd in the future. the technique is safe, simple and patients approval. after prp injections, if successful, the patients can resume normal behavior and an improved quality of life; the advantageous effects persist at least for a period of 6 months after injection, with no incidence of distinct side effects. the results herein suggest that for the management of tmj, prp injection is a technique bearing plenty of potential advantages, including superior functional outcomes and earlier recovery, reduced pain in tmj, reduced clicking and an increase in maximum mandibular mobility. references 1. cooper b, kleinberg i. establishment of a temporomandibular physiological state with neuromuscular orthosis treatment affects reduction of tmd symptoms in 313 patients. cranio; 2008.26(2):104-117. 2. okeson jp, de leeuw r. differential diagnosis of temporomandibular disorders and other orofacial pain disorders.dentclinnortham2011;55(1):105-20. 3. turp jc, komine f, hugger a: efficacy of stabilization splints for the management of patients with masticatory muscle pain: a qualitative sys+tematic review. clin oral investig, 2004; 8:179 4. kikuchi t, yamada h, fujikawa k: effects of high molecular weight hyaluronan on the distribution and movement of proteoglycan around chondrocytes cultured in alginate beads. osteoarthritis cartilage, 2001, 9:351 5. kumahashi n, naitou k, nishi h, et al: correlation of changes in pain intensity with synovial fluid adenosine triphosphate levels after treatment of patients with osteoarthritis of the knee with high-molecular weight hyaluronic acid. knee, 2011; 18:160 6. fortier la, hackett ch, cole bj: the effects of platelet-rich plasma on cartilage: basic science and clinical application. oper tech sports med 2011;19:154, 7. mccain et al. arthroscopic discopexy. j oral maxillofac surg 2015. 8. c€omert kilic¸, g€ung€orm€us¸, and s€umb€ull€u. prp injection for tmj osteoarthritis. american association of oral and maxillofacial surgeons j oral maxillofac surg2015; 73:1473-1483, 9. a. cie´slik-bielecka, t. bielecki, t. s. ga´zdzik, and t. cie´slik,“growth factors in the platelet-rich plasma as autogenic material which stimulates bone healing processes,” polish journal of stomatology, 2006 vol. 59, no. 7, pp. 510–517. 10. nitzan dw, dolwick mf, martinez gf. temporomandibular joint arthrocentesis: a simplified treatment for severe, limited mouth opening. j oral maxillofac surg; 1991; 49: 1163–7 . 11. silverman sol jr., eversole l, truelove e. essentials of oral medicine. new york: bc decker; 2001. j bagh college dentistry vol. 29(3), september 2017 an analysis of the 00 oral and maxillofacial surgery and periodontics 12. blasberg b, greenberg ms. burket's oral medicine diagnosis and treatment. 10th ed. new york: bc decker inc.; 2003. 13. anitua e, andia i, ardanza b, nurden p, nurden at: autologous platelets as a source of proteins for healing and tissue regeneration. thromb haemost2004; 91: 4e15 14. lippross s, moeller b, haas h, tohidnezhad m, steubesand n, wruck cj, et al: intraarticular injection of platelet-rich plasma reduces inflammation in a pig model of rheumatoid arthritis of the knee joint. arthritis rheum2011; 63(11): 3344e3353. 15. m. hancı et al. / journal of cranio-maxillo-facial surgery xxx (2014) 1e5 16. lee hr, park km, joung yk, park kd, do sh: platelet rich plasma loaded hydrogel scaffold enhances chondrogenic differentiation and maturation with upregulation of cb1 and cb2. j control release2012 ; 159(3): 332e337. 17. m. pihut, evaluation of pain regression in patients with temporomandibular dysfunction treated by intra-articular platelet-rich plasma injections2014 18. lippross s, moeller b, haas h, tohidnezhad m, steubesand n, wruck cj, et al:intraarticular injection of platelet-rich plasma reduces inflammation in a pigmodel of rheumatoid arthritis of the knee joint. arthritis rheum, 2011; 63(11):3344e3353. الخالصة الم في المفصل وصوت وقفل الفم ه الخلل الداخلي للمفصل الصدغي هو الظروف المؤلمة التقدمية وتسبب اختالل وظيفي في مفصل الفك ينتج عن مشتركة:خلفية بالزما هو عالج هناك عدة طرق لمعالجة هذة الحالة منها تحفظية واخرى جراحية لمعالجة االظطراب الداخلي للمفصل الصدغي.حقن الصفائح الدموية الغنية ال وناظور المفصل وكذلك العالجات التحفظية االخرى مثل غسل مفصل الفك عالج بسيط وقليل التدخل الجراحي لعالج االظطراب الداخلي للمفصل الصدغي من االدوية والعالجات الطبيعية من م فعالية الصفائح الدموية الغنية البالزما وتاثيرها في خفض او القضاء على االلم ،والنقروالحد من فتحة الفم في المرضى الذين يعانونيالهدف من الدراسة تقي الفك أن منهم من ال تستجيب للعالجات المحافظة وإظهار النتيجة أكثر قابلية للتنبؤ سريريا .اضطراب مشترك في مفصل 01، وشملت 4102إلى أكتوبر 4102، قسم جراحة الفم والوجه والفكين، من نوفمبر يتم إجراء هذه الدراسة في مستشفى اليرموك التعليم الموادوالطرق: وظيفة. تم تقييم العاما يعانون من أعراض آالم المفاصل الصدغي، وفتح الفم محدود والنقر خالل 22-01ح أعمارهم بين رجال( الذين تتراو8انثى و 24مريضا) س س من الصفائح الدموية الغنية البالزما بإبر 1،2اضطراب المفصل الصدغي الداخلي مع الفحص السريري وأكد مع صورة الرنين المغناطيسي. وقد تم حقن لمسطرة الجزء العلوي للمفصل. وجرى تقييم شدة آالم للمفصل الصدغي باستخدام مقياس التناظرية البصرية، وجرى تقييم أقصى فتحة الفم مع مقياس افي 40عيار أشهر. 2اشهر و 3شهر، 0بعد المترية وجرى تقييم النقر سريريا بواسطة سماعة الطبيب. تم قياس جميع المعلومات قبل اإلجراء ثم الفم والنقر تختفي في ة ، وتحسين في فتح٪12.2أشهرمن المتابعة والفحص السريري ومقارنة النتائج لوحظ انخفاض في األلم مع نسبة نجاح 2خالل نتائج: ال من المرضى . 11.3٪ لي للمفصل الصدغي، الفوائد العالجية والبساطة أظهر تقنيةحقن الصفائح الدموية الغنية البالزما في عالج المرضى الذين قدموا مع اضطراب داخ ستنتاج:األ والسالمة وقبول المرضى للتقنية وعدم وجود آثار جانبية كبيرة. mohammed f.doc j bagh college dentistry vol. 25(3), september 2013 prediction the widths pedodontics, orthodontics and preventive dentistry153 prediction the widths of maxillary and mandibular canines and premolars from the widths of maxillary incisors and first molars (iraqi study) mohammed nahidh, b.d.s., m.sc. (1) abstract background: this study aimed to use the combined mesio-distal crowns widths of maxillary incisors and first molars as predictors to the combined mesio-distal crowns widths of maxillary and mandibular canines and premolars. materials and methods: the sample included 110 iraqi arab subjects with an age ranged between 17-25 years and class i skeletal and dental relations. the crown widths of maxillary teeth and mandibular canines and premolars were measured at the largest mesio-distal dimension on the study casts using digital electronic caliper with 0.01 mm sensitivity. pearson’s correlation coefficient was used to determine the relation between the combined mesio-distal crowns widths of maxillary incisors and first molars and the combined mesio-distal crowns widths of maxillary and mandibular canines and premolars. regression analysis was used to determine the equations that predict the widths of maxillary and mandibular canines and premolars. paired sample t-test was used to compare between the actual and predicted mesio-distal crown widths. results and conclusions: the findings showed a non-significant difference between the predicted and actual mesiodistal crown widths; hence the combined mesio-distal widths of maxillary incisors and first molars can be used as predictors for the combined mesio-distal widths of maxillary and mandibular canines and premolars. key words: prediction, regression analysis, space analysis. (j bagh coll dentistry 2013; 25(3):153-157). الخالصة الضواحك و رض االسنان االنسي الوحشي المجتمع لالنیاببع ؤللتنب العلویة األولىاألضراس و للقواطع العرض االنسي الوحشي المجتمع استخدام ھدفت ھذه الدراسة إلى :خلفیةال .العلویة والسفلیة الفك عرض االنسي الوحشي السنانال تم قیاس. السنیةو ھیكلیةال العالقات الصنف األول من من ذوي سنة و 25-17بعمر یتراوح بین عراقي شخص 110 شملت العینة :الطرقالمواد و لتحدید بیرسون معامل ارتباط تم استخدام. على القوالب الدراسیة خاصتھم ملم 0.01 تصل الى حساسیةوب الرقمي االلكتروني الفرجار باستخداملي الفك السف ضواحكو وانیاب العلوي تحلیل استخدامب. العلویة و السفلیة الضواحكو عرض االسنان االنسي الوحشي المجتمع لالنیابمع العلویة األولىاألضراس و للقواطع العرض االنسي الوحشي المجتمع العالقة بین تم المتوقعالفعلي و عرض االسنان االنسي الوحشي بین للمقارنة. الضواحك العلویة و السفلیةو بعرض االسنان االنسي الوحشي المجتمع لالنیاب التي تتنبأ المعادالت تحدیدتم االنحدار . المقترن t اختبار استخدام للقواطع العرض االنسي الوحشي المجتمع یمكن استخدام ، وبالتاليالفعلي و المتوقع عرض االسنان االنسي الوحشي بین ةمعنوی قوفرعدم وجود ت النتائجأظھر :النتائج واالستنتاجات .العلویة والسفلیة الضواحكو بعرض االسنان االنسي الوحشي المجتمع لالنیابتنبؤ ل العلویة األولىاألضراس و .راغالف تحلیل، تحلیل االنحدار، التنبؤ :مفتاحیةالكلمات ال introduction accurate prediction of the space available to accommodate the un-erupted canines and premolars forms an important part of an orthodontic assessment in the mixed dentition as it is reported to assist dental practitioners to determine the treatment options for the patients (1). the accuracy, safety and simplicity are important criteria for a predictive method to become a part of the comprehensive case analysis in contemporary orthodontic practice (2). many methods had been employed to predict space for un-erupted teeth (3-17). two of them are the most commonly used methods; moyers’ probability tables (5) and the prediction equation of tanaka and johnston (14). however, these methods were developed on caucasian populations and their predictive accuracy on populations from other races is doubtful. this led to development of prediction equations and probability tables for different populations. many methods used regression equations based on the high linear correlation between relevant groups of teeth. the main factor in this (1)lecturer. department of orthodontics, college of dentistry, university of baghdad. category is the possibility of predicting the sizes of un-erupted teeth by using the widths of other fully erupted permanent teeth (2). in iraq, many researches had been performed to predict the widths for un-erupted canines and premolars. al-khashan (18) studied some of the dimensional features of the permanent teeth that had a relevance of orthodontic treatment in iraqi sample and compare to the results from different racial and ethnical groups. he found that the probability charts for prediction the width of cuspid and bicuspid utilizing the width of the lower incisor (moyer's chart) not to be accurate to be used for iraqi subjects. sofia (19) developed regression equations to predict the widths of maxillary and mandibular canines and premolars from maxillary and mandibular incisors. on the other hand, jargees (20) predicted the widths of premolars from the widths of deciduous molars. awni (21) compared two mixed dentition prediction methods that do not require the use of periapical radiographs of the un-erupted permanent lower teeth. the two compared methods were the tanaka/johnston (t/j) and the boston university (bu) prediction approaches. j bagh college dentistry vol. 25(3), september 2013 prediction the widths pedodontics, orthodontics and preventive dentistry154 she found that the t/j approach can be used when the only permanent four mandibular incisors have completely erupted, whereas the bu approach can be used when the deciduous canines and first molars are still present. abdulrasool (22) predicted the combined mesio-distal width of the maxillary and mandibular canines and premolars from the width of maxillary and mandibular first molar respectively, while al-bustani (23) used the sum of the mesio-distal widths of the left permanent maxillary central incisor, first molar and mandibular lateral incisor as predictor for the combined mesio-distal width of un-erupted maxillary and mandibular canines and premolars and compared her findings with sofia (19) and abdulrasool (22). in 2011, al-dabagh (24) predicted the width of maxillary canine from the width of mandibular canine, while jargees (25) was able to estimate the widths of un-erupted canines and premolars from the vistibulo-oral crown dimensions of permanent teeth using multiple regression equations. this study aimed to use the combined mesiodistal crowns widths of maxillary incisors and first molars as predictors to the combined mesiodistal crowns widths of maxillary and mandibular canines and premolars. materials and methods sample the sample comprised 110 iraqi arab subjects (55 males and 55 females) with an age ranged between 17-25 years had full complement of permanent teeth regardless the third molars, class i skeletal and dental relations (26) with no history of orthodontic treatment, bad oral habits, maxillofacial surgeries or defects. the teeth are free from caries, restorations, attrition or malformations. methods the subjects examined extraand intra-orally to fulfill the inclusion criteria. impressions for maxillary and mandibular arches were taken using alginate impression material, and then poured with dental stone. after setting, the impressions were inverted over a plastic mold containing plaster of paris to make the bases for the casts. the teeth in maxillary arch from the first molar to the first molar in the other side and the mandibular canines and premolars were measured at the largest mesio-distal dimension. the anatomic mesial and distal contact areas of each tooth were marked by a fine marker on the dental cast and then the greatest mesio-distal crown width was measured using electronic digital calipers (sensitivity 0.01 mm) held parallel to the occlusal plane (27). statistical analyses the data were subjected to computerized statistical analyses using spss program (version 19). the statistical analyses included: 1. descriptive statistics (means, standard deviations and the numbers and percentages of the cases that over and underestimated the actual widths of canines and premolars). 2. inferential statistics that comprised: • pearson’s correlation coefficient (r) to find out the relation between the combined mesio-distal widths of maxillary and mandibular canines and premolars with the combined mesio-distal widths of maxillary incisors and first molars. • independent sample t-test to test the presence of gender difference for the measurements. • simple regression analysis to determine the regression equations that can be used to predict the combined mesio-distal widths of maxillary and mandibular canines and premolars. • paired sample t-test to show whether there is significant difference between the predicted and actual mesio-distal widths of maxillary and mandibular canines and premolars in both genders. results and discussion most of the published articles tried to determine the width of canines and premolars using the methods of moyers or tanaka and johnston. nourallah et al. (28) depended upon the mandibular central incisors and maxillary first molars. bernabé et al. (29) depended on the maxillary and mandibular central incisors and maxillary first molar, while melgaço et al. (30), memon and fida (31) and mittar et al. (32) utilized the mandibular incisors and first molars. on the other hand, jaju et al. (33) depended on three measurements; the sum of width of mandibular incisors, the latter with mandibular and maxillary first molars separately and finally paredes et al. (34) found that the widths of maxillary central incisors and lower first molars were the best predictor for the widths of canines and premolars. in the present study, the maxillary first molars and incisors were chosen to predict the widths of maxillary and mandibular canines and premolars because they are erupted early in the oral cavity. the first step in the statistics is to demonstrate the relation between the combined mesio-distal j bagh college dentistry vol. 25(3), september 2013 prediction the widths pedodontics, orthodontics and preventive dentistry155 crowns dimensions of maxillary incisors and first molars (mddifm) with combined mesio-distal crowns dimensions of maxillary and mandibular canines and premolars (mddcp). as shown in table 1, there was strong direct highly significant correlation (p ≤ 0.001) between the measured variables; this comes in agreement with the previous findings (23,24,28-34). for practical purposes only, correlation coefficient values greater than 0.70 should be considered as reliable for prediction procedures (35). the value of the pearson’s correlation coefficient was ≥ 0.70 in this study. the results in table 2 showed the genders difference for the dimensions of teeth measured. like many findings (2,5,23,24,29-32), the males have wider teeth than females with a high significant difference; hence, the data were analyzed separately for males and females. table 1. the relation between the combined mesio-distal crowns dimensions of maxillary incisors and first molars (mddifm) with combined mesio-distal crowns dimensions of maxillary and mandibular canines and premolars (mddcp) mddifm mddcp maxillary mandibular males females males females r 0.8 0.7 0.75 0.7 p 0.000 (hs) 0.000 (hs) 0.000 (hs) 0.000 (hs) (hs)=highly significant p ≤ 0.001 table 2. descriptive statistics and genders difference for the measured variables variables genders descriptive statistics genders difference mean s.d. t-test p-value mddifm males 52.168 2.38 3.72 0.000 (hs) females 50.539 2.21 maxillary mddcp males 43.570 1.88 4.20 0.000 (hs) females 42.037 1.95 mandibular mddcp males 42.483 1.89 2.10 0.000 (hs) females 40.998 1.89 (hs)=highly significant p ≤ 0.001 a linear regression analysis was performed to develop the regression equations. the equation was calculated as; y= a + b x where “y” is the combined mesio-distal crowns widths of mandibular or maxillary permanent canines and premolars, “x” is the combined mesio-distal crowns widths of maxillary incisors and first molars, “a” is constant and “b” is the regression coefficient. the results showed the following equations: genders for maxillary arch for mandibular arch males mddcp= 10.758 + 0.629 × mddifm mddcp= 11.279 + 0.598 × mddifm females mddcp= 12.183 + 0.591 × mddifm mddcp= 11.209 + 0.589 × mddifm after calculation the predicted widths, paired sample t-test was applied to compare between the actual and predicted measurements. the results showed that there was non-significant difference between the predicted and actual mesio-distal crowns dimensions of both maxillary and mandibular canines and premolars (table 3), this is in accordance with the other studies (23,28-34). table 3. descriptive statistics and comparison between the predicted and actual combined mesio-distal crowns dimensions of maxillary and mandibular canines and premolars arch genders actual mddcp predicted mddcp difference between the predicted and actual mddcp mean s.d. mean s.d. mean difference s.d. t-test p-value maxillary males 43.570 1.88 43.572 1.49 0.002 1.14 0.013 0.99 (ns) females 42.037 1.95 42.052 1.31 0.015 1.45 0.079 0.937 (ns) mandibular males 42.483 1.89 42.476 1.42 -0.007 1.26 -0.044 0.965 (ns) females 40.998 1.89 40.977 1.3 -0.021 1.38 -0.115 0.909 (ns) (ns)=non-significant p > 0.05 j bagh college dentistry vol. 25(3), september 2013 prediction the widths pedodontics, orthodontics and preventive dentistry156 the ideal prediction method should determine no difference between predicted and actual widths of permanent canines and premolars. the mean differences and their standard deviations between the two methods are very small in its magnitude and are not clinically significant (table 3). prediction methods are not 100% precise and can overestimate or underestimate the actual size of un-erupted teeth. overestimation seems to be better to prevent lack of space, but this approach could suggest tooth extractions for some patients. overestimation of only 1 mm beyond the actual widths of the permanent canine and premolars on each side of the arch would not seriously affect an extraction or nonextraction decision (5,30,33). the numbers and percentages of cases that lie within the limit of 2 mm, over and underestimated the actual widths of the permanent canines and premolars (both sides of the maxillary and mandibular arches and both genders) were presented in table 4. the findings revealed small numbers of cases that did not lie within the limit of 2 mm. for both sides. this is considered as a point of strength to this method of prediction in addition to the proper selection of teeth that used in prediction, the high correlation between the variables and non-significant methods difference. in conclusion, the findings showed a nonsignificant difference between the predicted and actual mesio-distal crown widths; hence the combined mesio-distal widths of maxillary incisors and first molars can be used as predictors for the combined mesio-distal widths of maxillary and mandibular canines and premolars. this novel method of prediction is easy, simple, needs study models only (no radiographs) and depends on six teeth that erupt early and can be applied to predict the widths of canines and premolars in both jaws with high reliability. table 4. the numbers and percentages of cases that lie within the limit of 2 mm, over and underestimated the actual combined width of canines and premolars arch genders within the limit overestimation underestimation maxillary males 51 (92.73%) 2 (3.64%) 2 (3.64%) females 46 (83.64%) 5 (9.09%) 4 (7.27%) mandibular males 49 (89.09%) 4 (7.27%) 2 (3.64%) females 49 (89.09%) 3 (5.45%) 3 (5.45%) references 1. buwembo w, kutesa a, muwazi l, rwenyonyi cm. prediction of width of un-erupted incisors, canines and premolars in a ugandan population: a cross sectional study. bmc oral health 2012; 12: 23. 2. yousaf u, ijaz a. prediction of the sizes of un-erupted canines and premolars in pakistani subjects. pakistan oral dent j 2007; 27(1): 61-6. 3. smith hp, king dl, valencia r. a comparison of three methods of mixed dentition analyses. j pedod 1979; 3(4): 291-302. 4. staley rn, o’gorman tw, hoag jf, shelly th. prediction of the widths of un-erupted canines and premolars. jada 1984; 108(2):185-90. 5. moyers re. handbook of orthodontics. 4th ed. chicago: year book medical publishers; 1988. pp: 235-40. 6. staley hp, hoag j. prediction of the mesiodistal widths of maxillary permanent canines and premolars. am j orthod 1978; 73(2):169-77. 7. nance hn. the limitations of orthodontic treatment: i. mixed dentition diagnosis and treatment. am j orthod oral surg 1947; 33(4):177-223. 8. foster hr, wylie wl. arch length deficiency in the mixed dentition. am j orthod 1958; 44(6): 464-76. 9. ballard ml, wylie wl. mixed dentition case analysis-estimating size of unerupted permanent teeth. am j orthod oral surg 1947; 33(11): 7549. 10. cohen me. recognition of the developing malocclusion. dent clin north am 1959; 6: 299-311. 11. hixon eh, oldfather re. estimation of the sizes of un-erupted cuspid and bicuspid teeth. angle orthod 1958; 22(4): 236-40. (ivsl). 12. sim jm. minor tooth movement in children. 2nd ed. st. louis: c.v. mosby; 1977. 13. moorrees cfa, reed rb. correlations among crown diameters of human teeth. arch oral biol 1964; 9(6): 685-97. 14. tanaka mm, johnston le. the prediction of the size of unerupted canines and premolars in a contemporary orthodontic population. jada 1974; 88(4): 798-801. 15. brown je. predicting the mesio-distal crown width of un-erupted maxillary canines, first and second premolars. a master thesis. school of dentistry, university of tennessee, memphis, 1955. 16. fonsenca cc. predicting the mesio-distal crown width of the canine-premolar segment of maxillary dental arches. a master thesis. school of dentistry, university of tennessee, memphis, 1961. 17. ferguson fs, macko dj, sonnenberg em, shakun ml. the use of regression constants in estimating tooth size in a negro population. am j orthod 1978; 73(1): 68-72. 18. al-khashan ja. dimensional features of permanent teeth in iraqis. iraqi dent j 1989; special issue, abstract book: 69-70. 19. sofia sh. mesio distal crown diameter of permanent teeth and prediction chart for mixed dentition analysis. a master thesis. department of pedodontics, orthodontics and preventive dentistry, college of dentistry, university of mousl, 1996. j bagh college dentistry vol. 25(3), september 2013 prediction the widths pedodontics, orthodontics and preventive dentistry157 20. jargees ht. prediction of the mesiodistal crown diameter of the un-erupted lower premolars. a master thesis. department of pedodontics, orthodontics and preventive dentistry, college of dentistry, university of mousl, 2003. 21. awni khm. comparison between tanaka/ johnston and boston university prediction approaches in a group of iraqi pupils. al-rafidain dent j 2005; 5(2): 154-60. 22. abdulrasool hm. first permanent molar as a guide for space analysis in the canine and premolar region. iraqi orthod j 2005; 1(1): 66-7. 23. al-bustani shj. prediction of the canines and premolars size (comparative study). a master thesis. department of orthodontics, college of dentistry, university of baghdad, 2006. 24. al-dabagh dj. prediction of mesio-distal width of maxillary canines depending on mesio-distal width of mandibular canines by using regression equation. j bagh coll dentistry 2011; 23(2): 114-8. 25. jarjees ht. estimation of the crown widths of unerupted canine and premolars by using vistibulo-oral crown dimensions of permanent teeth. al-rafidain dent j 2012; 12(2): 350-5. 26. mitchell l. an introduction to orthodontics. 4th ed. oxford: oxford university press; 2013. 27. proffit wr, fields hw jr., sarver dm. contemporary orthodontics. 5th ed. st. louis: elsevier mosby; 2013. 28. nourallah aw, gesch d, khordaji mn, splieth c. new regression equations for predicting the size of unerupted canines and premolars in contemporary population. angle orthod 2002; 72(3): 216-21. 29. bernabé e, flores-mir c. are the lower incisors the best predictors for the unerupted canine and premolars sum? an analysis of a peruvian sample. angle orthod 2005; 75(2): 202-7. (ivsl). 30. melgaço ca, de sousa araújo mt, de oliveira ruellas ac. mandibular permanent first molar and incisor width as predictor of mandibular canine and premolar width. am j orthod dentofac orthod 2007; 132(3): 340-5. (ivsl). 31. memon s, fida m. development of a prediction equation for the estimation of mandibular canine and premolar widths from mandibular first permanent molar and incisor widths. eur j orthod 2012; 34(3): 340-4. (ivsl). 32. mittar m, dua vs, wilson s. reliability of permanent mandibular first molars and incisors widths as predictor for the width of permanent mandibular and maxillary canines and premolars. contemp clin dent 2012; 3(supp 1): s8-12s. 33. jaju kr, gulve nd, chitko ss. a new equation for predicting the width of unerupted permanent canines and premolars for cosmopolitan indian population. jaypee j 2010; 44(2): 83-8. 34. paredes v, gandia jl, cibrian r. a new, accurate and fast digital method to predict unerupted tooth size. angle orthod 2006; 76(1): 14–19. (ivsl). 35. vardimon ad, lambertz w. statistical evaluation of torque angles in reference to straight-wire appliance (swa) theories. am j orthod 1986; 89(1): 56-66. j bagh college dentistry vol. 28(4), december 2016 evaluation of impact restorative dentistry 9 evaluation of impact and transverse strength of denture bases repaired with nano reinforced resin hikmat j. al-judy, b.d.s., m.sc., ph.d. (a) ali n. ahmed, b.d.s., m.sc. (b) rola w. abdul-razak, b.d.s., m.sc. (b) abstract background: failure of resin bases were a major disadvantage recorded in the constructed dentures. reinforcements of the repair joint with nano fillers represent an attempt to enhance the strength and durability. the purpose of the research was to estimate the influence of nano fillers reinforcement with (zro2 and al2o3) on impact and transverse strength of denture bases repaired with either cold or hot processing acrylic resin. materials and methods: a hundred and forty (140) samples were processed with hot cured resin and organized in subgroups depending on the repair materials and condition (without repair (control), repair with hot cure, cold cure, hot and cold cure reinforced with either (5% zr2o or 0.5% al2o3). the samples in these subgroups were processed depending on the test applied (impact and transverse strength). the samples were immersed in distalled water for about four weeks at 37°c before testing, after that, the samples prepared for each test were subdivided depending on the selected subgroups of the study. repairing the samples with cold cure resin was done with the aid of ivomet; after that the samples incubated for 48 hours in 37°c distilled water. transverse strength test was done by using instron universal testing machine while the impact test was done by using charpy impact testing machine. results: the reinforcement of the repair joint with nano-fillers improves both impact and transverse strengths. conclusion: repair strength is directly proportional to the mode of resin processing, reinforcement with nano-fillers improve the strength of the repaired joint significantly. key words: nano-fillers, reinforcement, repair joint. (j bagh coll dentistry 2016; 28(4):9-15) introduction the primarily aims of any denture repair were to recreate the pre-fracture strength of the denture and to preserve the durability of that denture for long time and with low cost. (1) the dentures were susceptible to fracture either by sudden impact outside the patient mouth (2), or by continuous bending inside the patient mouth during masticatory function and in this case the fracture site is expected to be near the midline. (3) cold cured resin provide a fast and simple method for repairing fractured dentures, although the durability of the repaired denture is reduced rendering it clinically with inferior performance.(4) also heat cured and now a day's light cured resin represent the most successful materials used in the repair of fractured dentures with better performance.(1) the incorporation of the nano-fillers to the polymer matrix provides an opportunity for the enhancement of the mechanical properties of the resulted resin composite. this would be influenced by the ratio, adhesion between the polymer matrix and the fillers, configuration and structure and finally the chemical constituent of those fillers. (5) for example zro2 and al2o3 addition to the resin significantly enhance the impact and transverse strength of the denture base by consuming the amount of energy applied and arresting plastic deformation. (6) (a) assistant professor, department of prosthodontics, college of dentistry, baghdad university. (b) lecturer, department of prosthodontics, college of dentistry, baghdad university. also these fillers will not influence the esthetic qualities of the acrylic resin because of its white color. (7) the aims of this study were to estimate the influence of nano-fillers incorporation (5%zro2 and 0.5% al2o3) on impact and transverse strength of denture bases repaired with either hot or cold cured resin and comparing the results with none repaired samples. materials and methods a. the preparation of plastic mold: depending on the type on strength test intended, two plastic patterns were selected and made: 1. a rectangular pattern with dimensions of (65mm x 10mm x 2.5mm) was used for transverse strength test. 2. a bar pattern with dimensions of (80mm x 10mm x 4mm) was used for impact strength test. b. the preparation of the stone mold: a universal metallic flask was used for construction of the stone mold as illustrated in figure 1. figure 1: metal flask used and stone mold construction. j bagh college dentistry vol. 28(4), december 2016 evaluation of impact restorative dentistry 10 then after the removal of the plastic patterns the stone mold were ready for acrylic resin packing. the acrylic resin (spofa dental, europe) were mixed and packed in the stone mold following the recommendation of the manufacturer, after that the water bath processing was accomplished by using short cycle. followed by bench cooling and deflasking, then samples retrieving with finishing and polishing. the samples were stored in 37°c distilled water for about four weeks. (8) samples repair for impact and transverse strength test: 1. hot cured repaired samples: the finished samples for transverse strength were attached to plastic orientation device made especially for this study had central groove with dimensions of (31mm × 10mm × 2.5mm). while for the impact strength the dimensions were (38.5mm ×10mm×4mm) for length, width and depth respectively.(9) these devices permit the samples to fracture with a bevel angle of 45° and provide a space of 3mm between the two halves of the sample. then the space between them were filled with the repair resin material after painting the two halves with hot cured monomer by using zero degree fine brush for duration of 3 minutes. (10) resin was manipulated according to manufacturer recommendations and processed in short curing cycles in a water bath curing machine for 1.5 hour at 74°c then 30 minutes at 100°c. then the samples were allowed for bench cooling then deflasking was done and samples were retrieved, finished and polished before they were incubated at 37°c for 48 hours, and as shown in figure 2. figure 2: (a): repaired samples ready for testing; (b): plastic orientation device for sample holding. 2. cold cured repaired samples: the same procedure was done but cold cured monomer was used and the samples were cured by using an (ivomet) machine (palmat universal/ kulzer) at 30 ib/inch2 with temperature of 37°c for 15 minutes. (11) the incorporation of either zro2 or al2o3 nano fillers were done to the repair materials which were either cold cured or hot cured acrylic resin. nano fillers incorporation to repair resin: the silanated nano fillers were added to the monomer of the repair material weather it was hot or cold cured in order to provide chemical union between the nano-fillers and the resin matrix and by selection of the most appropriate concentration which were 5% for zro2 and 0.5% for al2o3 and the addition were accomplished with the aid of sonicated mixing device for a duration of 180 seconds in order to provide maximum desperation of the fillers to the monomer. (12, 13) the strength testing of the samples: 1. for impact strength test: a seventy samples were processed and became ready for testing, these samples include control without repair (10), 30 samples repaired with hot cured resin (10 without fillers, 10 with 5% zro2 and 10 with 0.5% al2o3 ) and another 30 samples repaired with cold cured resin (10 without fillers, 10 with 5% zro2 and 10 with 0.5% al2o3 ). the impact strength was measured by using charpy type impact testing machine (impact tester, n.43-1, inc.usa), the impact strength were estimated by the following equation; i= e/bd × 103; where i is impact strength in (kj/m2) and e is impact energy applied on samples in (j), b is width of the sample in (mm), d is thickness of the sample in (mm). the energy was applied at a scale of 2 (joules). 2. for transverse strength test: another seventy samples includes: control without repair (10), 30 samples repaired with hot cured resin (10 without fillers, 10 with 5% zro2 and 10 with 0.5% al2o3) and another 30 samples repaired with cold cured resin (10 without fillers, 10 with 5% zro2 and 10 with 0.5% al2o3). the transverse strength was measured by using instron universal testing machine, the transverse strength was estimated by the following equation s= 3pi/2bd2; where s is transverse strength in (n/mm2) and p is peak load applied on samples in (n) and i is the space separating supporting holders in (mm), b is width of the sample in (mm), d is depth of the sample in (mm) the load was applied at a scale of 500 (n) with cross head speed of (1mm/min) and as shown in figure 3 and 4. figure 3: instron universal testing machine during sample testing. a b j bagh college dentistry vol. 28(4), december 2016 evaluation of impact restorative dentistry 11 figure 4: repaired samples after finishing the transverse strength testing. statistical analysis of the data of the study was done by using three ways analysis of variance (anova) table to organize the data according to the addition of nano-fillers and their type in addition to the curing method and the confidence level were set at 95%. also t-test was applied during making comparison between the means to detect the level of significant differences. results the findings of the impact and transverse strength tests were presented in tables 1&2 and figures (5) and (6). table 1: the data of means in (kj/m2) with standard deviations and standard error for impact strength test. groups mean s.d. s.e. min. max.. control 8.70 0.57 0.26 7.77 9.2 cold alone 3.73 0.17 0.08 3.52 3.99 2cold& zro 4.46 0.54 0.24 3.54 4.87 2o3cold& al 3.44 1.07 0.48 2.08 4.65 hot alone 6.14 0.46 0.21 5.35 6.46 2hot & zro 7.01 0.84 0.37 6.02 8.07 2o3hot & al 6.58 0.39 0.18 6.06 7.16 figure 5: bar chart of means in (kj/m2) for impact strength test. table 2: the data of means in (n/mm2) with standard deviations and standard error for transverse strength test. groups mean s.d. s.e. min. max. control 99.08 6.71 3.00 90 106.8 cold alone 62.66 2.08 0.93 61.2 66 2cold& zro 67.80 4.28 1.92 63.6 73.2 2o3cold& al 55.68 1.96 0.88 54 58.8 hot alone 65.22 2.45 1.10 61.2 67.2 2hot & zro 77.64 5.24 2.34 72.4 85.2 2o3hot & al 83 3.46 1.55 79.6 87.6 figure 6: bar chart of means in (n/mm2) for transverse strength test. for the f test and anova table for the detection of differences between groups and within groups, the data revealed high significant difference for both impact and transverse strength tests and these findings were shown in table 3 and 4. table 3: f-test and anova table for comparison of the groups and between groups for impact strength test. groups sum of square d.f m.s. f-test pvalue between groups 111.13 6 18.52 45.4 0.000 hs within groups 11.41 28 0.41 total 122.55 34 table 4: f-test and anova table for comparison of the groups and between groups for transverse strength test. anova sum of squares d.f m.s. f-test p-value between groups 6480.81 6 1080.14 64.68 0.000 hs within groups 467.57 28 16.70 total 6948.38 34 j bagh college dentistry vol. 28(4), december 2016 evaluation of impact restorative dentistry 12 for the comparison between the control and various experimental groups, the results revealed that for impact strength test, all the experimental groups showed high significant reduction in the impact strength and as illustrated in table 5. table 5: t test for the comparison between the control and the experimental groups for impact strength test. groups t-test d.f. p-value sig. control &cold alone 18.523 8 0.000 hs 2control &cold zro 12.081 8 0.000 hs 3o2control &cold al 9.699 8 0.000 hs control &hot alone 7.777 8 0.000 hs 2control & hot zro 3.721 8 0.006 hs 3o2& hot alcontrol 6.832 8 0.000 hs and for the transverse strength test, also the data showed that all the experimental groups showed high significant reduction in the transverse strength, and as revealed in table 6. table 6: t test for the comparison between the control and the experimental groups for transverse strength test. groups t-test d.f. p-value sig. control &cold alone 11.597 8 0.000 hs 2control &cold zro 8.788 8 0.000 hs 3o2control &cold al 13.886 8 0.000 hs control &hot alone 10.603 8 0.000 hs 2control & hot zro 5.634 8 0.000 hs 3o2control & hot al 4.764 8 0.001 hs effect of nano addition: for the effect of nano fillers reinforcement to the repair media when compared with repair without reinforcement, the data revealed nonsignificant improvements for all repair medias reinforced with nano-fillers except for repair with cold cure with zro2 which revealed significant improvements in the impact strength (table 7). table 7: t test for comparison between groups reinforced with nano-fillers with the non reinforced one, for impact strength test. groups t-test d.f. p-value sig 2cold alone & cold zro -2.901 8 0.020 s. 3o2cold alone & cold al 0.607 8 0.561 ns 2hot alone & hot zro -2.035 8 0.076 ns 3o2hot alone & hot al -1.601 8 0.148 ns while for transverse strength test, the data revealed significant improvements for all repair medias reinforced with nano-fillers except for repair with cold cure with al2o3 which revealed high significant reduction in the transverse strength and as shown in table 8. table 8: t test for comparison between groups reinforced with nano-fillers with the non reinforced one, for the transverse strength test. groups t-test d.f. p-value sig 2cold alone & cold zro -2.413 8 0.042 s 3o2cold alone & cold al 5.460 8 0.001 hs 2hot alone & hot zro -4.805 8 0.001 hs 3o2hot alone & hot al -9.381 8 0.000 hs effect of polymerization methods: for the effect of polymerization methods the data revealed high significant improvements for all repair with hot cure resin when compared with cold cure one for all groups in the impact strength (table 9). table 9: t test for comparison between groups repaired with cold cure resin with groups repaired with hot cured one, for the impact strength test. groups t-test d.f. p-value sig cold alone & hot alone -11 8 0.000 hs cold zro2& hot zro2 -5.747 8 0.000 hs cold al2o3& hot al2o3 -6.165 8 0.000 hs while for transverse strength test, the data revealed significant improvements for all repair with hot cured resin compared with cold cured one except for repair with cold cure alone compared with hot cured alone which revealed non significant improvement in the transverse strength (table 10). table 10: t test for comparison between groups repaired with cold cure resin with groups repaired with hot cured one for the transverse strength test. groups t-test d.f. p-value sig cold alone & hot alone -1.782 8 0.113 ns cold zro2& hot zro2 -3.252 8 0.012 s cold al2o3& hot al2o3 -15.363 8 0.000 hs effect of nano-fillers type: for the effect of nano fillers type the data revealed non-significant reduction for all repair groups reinforced with al2o3 nano-fillers compared with groups repaired with zro2 for the impact strength (table 11). table 11: t test for comparison between groups repaired with al2o3 with groups repaired with zro2 for the impact strength test. groups t-test d.f. p-value sig cold zro2& cold al2o3 1.915 8 0.092 ns hot zro2& hot al2o3 1.055 8 0.322 ns j bagh college dentistry vol. 28(4), december 2016 evaluation of impact restorative dentistry 13 while for transverse strength test, the data revealed high significant reduction of cold cured repaired with al2o3 compared with groups repaired with zro2. while for the hot cured repair; it revealed non-significant improvement in the transverse strength when the al2o3 fillers were used compared with zro2 (table 12). table 12: t test for comparison between groups repaired with al2o3with groups repaired with zro2 for the transverse strength test. groups t-test d.f. p-value sig cold zro2& cold al2o3 5.750 8 0.000 hs hot zro2& hot al2o3 -1.910 8 0.093 ns discussion numerous techniques were existed to restore the fractured resin dentures to their original strength the preparation of the surfaces and sites to be joined are of paramount significance of ensuring prolonged service life of the prosthesis. mechanical or chemical treatment were introduce to change the joint surface morphology or by improving the acrylic resin surface chemistry of better adhesion promotion. (28) the addition of fillers in the form of nano particles had a various shapes and sizes into a resin polymer that serve as a composite matrix which improve the mechanical behavior of the resulted composite material. (30) the results of the present study were explained according to the influence of each variable involve in the study and its relevant effect on both the impact and transverse strength and as follows: a. effect of nano-fillers incorporation: the impact strength was improve after the incorporation of nano-fillers and the maximum improvement were noticed when the repair were done with cold cured acrylic reinforced with zr2o nano-fillers as shown in table (7). the explanation were that the spaces formed around the nanofillers leads to improvement in the impact strength by altering the pathway of growing cracks as a result of the perfect bond strength between the nano-fillers and polymer matrix. also the growing cracks were arrested due to the nano-fillers being protected by formation of internal cross linking shear bonds between the fillers and the polymer matrix leading to increase the molecular bonding weight. (14, 23) the transverse strength, were improved by the addition of both types of nano-fillers, table (8). this is due to that these fillers were perfectly spread inside the polymer matrix and when the polymerization temperature where applied during curing, these fillers will attains the alpha phase which is the requested phase characterized by high stable hexagonal configuration, so when the mechanical stress builds up during testing, and growing cracks start to develop, this hexagonal configuration initiated and consume the mechanical energy necessary for cracks union and fracture developments. (15, 25, 26) on the other hand, the reduction in the transverse strength of the samples repaired with cold cure reinforced with al2o3 had many explanatory reasons which may be due to; the concentration of too many stresses by high concentration of fillers which in turn changing the modulus of elasticity of the resin to be more stiff and void formation and air entrapment which will behave as weakening points for the continuity of the matrix resulting in facilitating the spread of the cracks inside the vicinity of the matrix with reduction in the total area of force distribution. also, spaces creation in the polymer matrix with insufficient unity between the fillers and polymers may also play role for such finding. (16, 24) b. effect of polymerization methods: all tested groups repaired with hot cured resin leads to high significant improvements in both impact and transverse strength (table 9, 10). this attributed the higher curing temperature and pressure applied during heat polymerization leading to more softening effects on the repaired joints and better spreading of the repair medium with stronger repair joint (17), in addition the nanofillers added to the resin will reduce the amount of coefficient of thermal expansion due to the great interfacial interaction between the resin matrix and nano-fillers which result in limitation of polymer mobility (27), while the cold curing repair resin is cured with lower amount of pressure applied leading to the formation of porosities from the internal type and also the higher amount of residual monomer contributed to the formation of many voids inside the repair medium, these spaces will act a stress concentration area facilitating the micro cracks creation and propagation of cracks to total failure when load is applied. (17, 5) c. effect of nano-fillers type: for the impact strength testing and for all curing methods, table 11 revealed that repairing with zro2 nano-fillers leads to non-significant improvement when compared with al2o3 nanofilles and that’s because of the conversion of both ceramic fillers leads to higher molecular volume exerting pressure on the supporting resin matrix leading to inhibition in crack propagation (18), and the metal oxide with saline coupling agent will reduce the amount of water absorbing by polymer by decreasing the voids between the resin matrix j bagh college dentistry vol. 28(4), december 2016 evaluation of impact restorative dentistry 14 and nano-fillers leading to less water sorption and overall improvement in mechanical properties. (29) the transverse strength was reduced when repairing was done with cold cured acrylic reinforced with al2o3 nano-fillers and this was attributed to the harmful effect of the weak bond strength between the nano-fillers and the polymer matrix compared with the zro2. (19) the result revealed that during repair with hot cured resin reinforced with al2o3 nano-fillers the transverse strength were non significantly improved and this explained by the fact that the crystals configuration of that fillers tends to be converted to the highly fixative alpha hexagonal structure during application of increasing temperature as for example, hot curing. so, when loads are applied during the transverse strength testing, the conversion will be started simultaneously with the cracks developments and propagation, also this configuration will consume the fracture energy and arrest the fracture. (20) while for the repair with hot cure resin reinforced with zro2, the transverse strength were reduced due to that the higher processing temperature will resulted in higher range of conversion from tetragonal to monoclonic crystal configuration accompanied by plastic deformation which will negatively affect its strength and shelf life.(21,22) references 1. stipho hd, stipho as. effectiveness and durability of repaired acrylic resin joint. j prosthet dent 1987; 58: 249-53. 2. stipho hd. repair of acrylic resin denture base reinforce with glass fiber. j prosthet dent 1998; 80: 546 -50. 3. beyli ms, von fraunhofer ja. an analysis of causes of fracture of acrylic resin dentures. j prosthet dent 1981; 46(3): 238-41. 4. nitkin da, sponzo mt. simplified denture repair technique. j prosthet dent 1979; 41: 355-7. 5. jordan j, jacob kl, shart ma. experimental trends in polymer. nano-composites – a review. mater sci eng 2005; 393:1-11. 6. asar nv, hamdi a, turan k, ilser t. influence of various metal oxides on mechanical and physical properties of heat-cured polymethyl methacrylate denture base resins. j adv prosthodont 2013; 5: 241-7. 7. ichikawa y, akagawa y, nikai h, tsuru h. tissue compatibility and stability of a new zirconia ceramic in vivo. j prosthet dent 1992; 68(2): 322-6. 8. polyzois gl, tarantili pa, frangou mi, et al. fracture force, deflection at fracture, and toughness of repaired denture resin subjected to microwave polymerization or reinforced with wire or glass fiber. j prosthet dent 2001; 86: 613-9. 9. al-nadawi lm. the effect of different surface treatment and joints surface shapes on some mechanical properties of the repaired acrylic denture base resin cured by two different techniques. a master thesis, college of technology, university of technology 2005. 10. hasan rh. denture teeth bond strength to heat water bath and microwave cured acrylic denture base material. comparative study. a master thesis, college of dentistry, mosul university, 2002. 11. al-mudarris ba. effect of metal inserts on the transverse strength and deflection of repaired acrylic specimens. a master thesis, college of dentistry, university of baghdad, 1999. 12. safi in. evaluation of the effect of modified nanofillers addition on some properties of heat cure acrylic resin denture base material. a master thesis, department of prosthetic dentistry, college of dentistry, university of baghdad, 2011. 13. muklif or. studying the effect of addition a composite of silanized nano-al2o3 and plasma treated polypropylene fibers on some physical and mechanical properties of heat cured pmma denture base material. a master thesis, college of dentistry, university of baghdad, 2015. 14. sun l, gibson rf, gordaninejad f, suhr j. energy absorption capability of nanocomposites: a review. composites sci technol 2009; 69(14): 2392-409. 15. ayad nm, badawi mf, fatah aa. effect of reinforcement of high-impact acrylic resin with zirconia on some physical and mechanical properties. rev clín pesq odontol (impr.) 2008; 4(3): 145-51. 16. grant aa, greener eh. whisker reinforcement of polymethyl methacrylate denture base resins. australian dent j 1967; 12(1): 29-33. 17. dhiman rk, chowdhury sk. midline fracture in single maxillary complete acrylic vs. flexible denture. m jafi j 2009; 65:141-5. 18. stevens r. an introduction to zirconia; zirconia and zirconia ceramics. 2nd ed. twickenham; magnesium elekrtum; 1986. 19. chaijareenont p, takahashi h, nishiyama n, arcsorrnukit m. effect of different amounts of 3methacryloxypropyltrimethoxysilane on the flexural properties and wear resistance of alumina reinforced pmma. dent mater j 2012; 31(4): 623–8. 20. ellakwa ae, morsy ma, ei-sheikh am. effect of aluminum oxide addition on the flexural strength and thermal diffusivity of heat-polymerized acrylic resin. j prosthodont 2008; 17: 439-44. 21. chevalier j, olagnon c, fantozzi g. subcritical crack propagation in 3y-tzp ceramics: static and cyclic fatigue. j am ceram soc 1999; 82: 3129-38. 22. studart ar, filser f, kocher p, gauckler lj. in vitro lifetime of dental ceramics under cyclic loading in water. biomaterials 2007; 28: 2695-705. 23. ahmed ma, ebrahim mi. effect of zirconium oxide nano-fillers addition on the flexural strength, fracture toughness and hardness of heat polymerized acrylic resin. world journal of nano science and engineering 2014; 4: 50-7. 24. arora p, singh sp, arora v. effect of alumina addition on properties of poly-methyl methacylate-a comprehensive review int j biotech trends stech, ijbtt 2015; (9): 1-7. 25. jasim bs, ismail ij. the effect of silanized alumina nano-filling addition on some physical and mechanical properties of heat cured polymethyl methaglate denture base material. j bagh coll dentistry 2014; 26(2): 18-23. 26. satarabadi m, kharcari nm, rezai a. an experimental investigation of ha/al2o3 nanoporticles on mechanical properties of restoration j bagh college dentistry vol. 28(4), december 2016 evaluation of impact restorative dentistry 15 materials. engineering solid mechanics 2014; 173182. 27. safi in. evaluation of the effect of nano-fillers (tio2, al2o3, sio2) addition on glass transition temperature, e-medulas and coefficient of thermal expansion of acrylic denture base material. j bagh coll dentistry 2014; 26(1): 37-41. 28. memarian m, shayestenmj jm. the effect chemical and mechanical treatment of the denture base resin surface on the shear bond strength of the denture repairs. rev clin odontol curitiba 2009; 5(1): 11-17. 29. asar nv, albayrak h, korkmaz t, turkyilmaz i. influence of varies metal oxides on mechanical and physical properties of heat-cured j adv prosthodont 2013; 5: 241-7. 30. hasan sab, dimitrijevic mm., kojovic a, stojanovic db, dwicic ko, heinemann kmj, aleksic r. the effect of the size and shape of alumina nanofillers on the mechanical behavior of the pmma matrix campsite. j serb chem soc 2014; 79(10): 1295-307. taghreed.doc j bagh college dentistry vol. 27(2), june 2015 oro-facial manifestations oral diagnosis 93 oro-facial manifestations, oxidative stress marker and antioxidant in serum and saliva of patients with beta thalassemia major muaid s. abbas shamsah, b.d.s. (1) taghreed fadhil zaidan, b.d.s., m.sc., ph.d. (2) abstract background: beta thalassemia is a typically autosomal recessive form of severe anemia which is caused by an imbalance of two types of protein (alpha and beta) subunits of hemoglobin. oxidative stress imbalance is the equilibrium between pro-oxidant\antioxidant statuses in cellular system, which results in damaging the cells. antioxidant is a chemical that delays the start or slows the rate of lipid oxidation reaction and it play a very important role in the body defense system against reactive oxygen species. the aims of this study were to recorded the orofacial manifestations in beta thalassemic patients and assess the oxidative stress marker malondialdehyde in serum and salivs and their role in the pathogenesis of beta thalassemia and evaluation the antioxidant uric acid in serum and saliva of those patients. methods: the study included fifty eight beta thalassemic major patients, twenty eight patients with periodontitis and thirty patients without periodontitis and twenty nine healthy subjects that were age matched with the patients. orofacial manifestations recorded clinically, serum and saliva malondialdehyde and uric acid were measured in all subjects. results : the main oro-facial manifestations were malocclusion ,rodent face, brown pigmentation of oral mucosa and incompetent lip.the mean serum and saliva malondialdehyde was significantly higher in thalassemic patients with periodontitis (p<0.001). serum and saliva uric acid was significantly higher in thalassemic patients without periodontitis (p<0.001). conclusions: malocclusion was the most prevalent oro-facial manifestations in beta thalassemic patients, increased serum and saliva malondialdehde refer to the role of oxidative stress in the pathogenesis of beta thalassemia. uric acid increased to counteract the elevation in the oxidative stress process. key words: beta thalassemia, malondialdehyde, malocclusion, uric acid. (j bagh coll dentistry 2015; 27(2):93-97). introduction the β-thalassemias are genetic disorders of hemoglobin synthesis characterized by deficient (β+) or absent (β0) synthesis of the beta-globin subunit of hemoglobin molecule (1). beta thalassemia is prevalent in mediterranean countries, the middle east, central asia, india, southern china, and the far east as well as countries along the north coast of africa and in south america. the highest carrier frequency is reported in cyprus (14%), sardinia (10.3%), and southeast asia (2).clinically divided into 3types; thalassemia minor is most common form of β thalassemia which lack of beta protein causes no problems in the normal functioning of the hemoglobin (3),β-thalassemia intermedia have mild to moderate anemia. the clinical phenotype of thalassemia intermedia is roughly intermediate between thalassemia major and minor (4). thalassemia major, also known as cooley’s anemia and mediterranean anemia, is the most severe form of β-thalassemia, since both mutations of both β-globin alleles results in severely impaired β-globin chain production (5). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. beta thalassemia major characteristic by infancy onset severe anemia and required lifelong blood transfusion for survival. also untreated beta thalassemia major are hepatosplenomegaly, jaundice, growth retardation , poor musculature, leg ulcer, development of masses from extramedullary hematopoiesis and bone deformities that result from expansion of the bone marrow (6,7). orofacial manifestations were prevalent in beta thalassemia, which included prominent frontal and check bossing, depression of the bridge of the nose, protrusive premaxilla (rodent face), flaring of the maxillary anterior teeth, spacing teeth, lip retraction and varying degree of malocclusion (8) free radicals can be defined as molecules or molecular fragments containing one or more unpaired electrons in atomic or molecular orbitals, which was steal electrons from cells, dna, enzymes and cell membranes and lead to cells are damaged, enzymes cannot do their jobs and compromising the integrity of cellular membranes leaves them vulnerable to attack by viruses, bacteria and other invaders. malondialdehyde is one of several lowmolecular-weight end products formed via the decomposition of certain primary and secondary lipid peroxidation products (9).antioxidants inhibit the formation of free radical and hence contributes to the stabilization of the lipid sample. naturally, j bagh college dentistry vol. 27(2), june 2015 oro-facial manifestations oral diagnosis 94 there is a dynamic balance between the amount of free-radicals generated in the body and antioxidants to quench and/or scavenge them and protect the body against their deleterious effects (10). uric acid was an important hydrophilic radical scavenger (11). urate is predominant salivary antioxidants. previous studies showed estimation of the uric acid concentration in saliva might be better index of uric acid production in the body than the uric acid concentration in blood or urine (12). periodontitis comprise a group of diseases, which are inflammatory in origin and generally affect the connective tissues attachment and supportive bone present around the teeth, there was direct link between oxidative mechanism and periodontitis (13,14). the purpose of this study is to assessment the oro-facial manifestations and evaluates the oxidative stress and its role in the pathogenesis of beta thalassemia major patients through the study of serum and saliva malondialdehyde and the status of uric acid in serum and saliva of beta thalassemic major patients. materials and methods fifty eight thalassemic patients with no history of systemic diseases with age range 10-20 years, they divided into twenty eight thalassemic patients with periodontitis and thirty thalassemic patients without periodontitis and twenty nine healthy subjects with age matched with study patients. thalassemic patients were diagnosed by hematologist according to laboratory investigations. extra and intra-oral examination was done for each individual and also periodontitis diagnosed by assessment of clinical attachment loss. five ml. of blood sample was aspirated using disposable syringe from each subject which was collected in sterile disposable tubes then centrifuged and aspirated the supernatant serum and stored in frozen at -20 c° for analysis. five ml whole unstimulated saliva was taken from each subject and centrifuged, aspirated the clear supernatant and stored at -20c° for analysis. malondialdehyde, lipid peroxidation end products react with thiobarbituric acid under acidic condition and heating to give a pink color that measured spectrophotometrically at 532nm.serum and saliva uric acid was measured by oxidized uric acid by uricase to allantoine and hydrogen peroxide, which under the influence of pod,4aminophenaxzone and 2-4 dichlorophenol sulfonate form a red quinoneimine compound that measured spectrophotometrically at 520nm. results the mean age of thalassemic patients with periodontitis was 15.10 years, the mean age of thalassemic patients without periodontitis was 14.83 years and the mean age of healthy subjects was 15.83 years. the study showed that the main oro-facial manifestations were malocclusion (60%) followed by rodent face (35%) , brown pigmentation of oral mucosa (23%) then incompetent lip (8%). the present study showed that serum and saliva malodialdehyde was highly significantly higher in thalassemic patients with periodontitis than that in other study groups using f-test (p<0.001).the study showed that there was no significant correlation between serum and saliva malondialdehyde in any of study groups (p>0.05). this study also showed that the serum and saliva uric acid were highly significantly higher in thalassemic patients without periodontitis using ftest (p<0.001), there was a positive significant linear correlation between serum and saliva uric acid in thalassemic patients without periodontitis (p<0.05), also a positive highly significantly linear correlation between serum and saliva uric acid in thalassemic patients with periodontitis (p<0.001) was found. table 1: the mean, sd and anova test of malondialdehyde between study groups variable & study groups mean sd f p serum mda (µmol/l) 87.125<0.001** thalassemic with periodontitis 7.30 1.43 thalassemic without periodontitis 6.65 1.38 healthy subject 3.61 0.20 saliva mda (µmol/l) 31.658<0.001** thalassemic with periodontitis 2.65 1.32 thalassemic without periodontitis 2.01 0.73 healthy subject 0.85 0.26 **highly significant (p<0.001) j bagh college dentistry vol. 27(2), june 2015 oro-facial manifestations oral diagnosis 95 table 2: the mean, sd and anova test of uric acid between study groups study groups mean sd f p u ri c a ci d serum uric acid (mg/dl) 45.897<0.001** thalassemic with periodontitis 6.93 1.72 thalassemic without periodontitis 7.63 2.96 healthy subject 3.02 0.53 saliva uric acid (mg/dl) 5.147 0.008* thalassemic with periodontitis 2.43 0.96 thalassemic without periodontitis 3.34 2.72 healthy subject 1.91 0.90 *significant (p<0.05), **highly significant (p<0.001) figure 1: the correlation between serum and saliva malondialdehyde in each study group. figure 2: the correlation between serum and saliva uric acid in each study group. discussion the fact of orofacial complications is due to, when ineffective erythropoiesis damages the red blood cells (rbc) leading to severe anemia, the body responds by increasing the production of red blood cell, consequently causing expansion of bone marrow up to 15-30 times higher than the normal amount. the bone marrow expansion causes hyperplasia of the alveolar process of the maxilla at the expense of the sinus's normal volume. this in turn leads to the occurrence of maxillary anterior teeth protrusion, spacing between upper anteriors, anterior open bite. the skull and face deformities are closely related to the patient's age, the intensity of anemia, and the beginning time of treatment. patients who receive inadequate blood transfusion in childhood will have more bony changes in adolescence (15). in the present study the results showed that the most prevalent orofacial manifestations were malocclusion (60%), then followed by rodent face (35%),oral soft tissue brown pigmentation (23%), then incompetent lip (8%) and this was agree with elangovan et al. (16) who reported that the most prevalence orofacial manifestations of betathalassemia major patients were malocclusion, rodent face and incompetent lip. norri and izdeen (17), jaafar and al-aswed, (18) reported that malocclusion was the main oro-facial manifestations in beta thalassemia major patients. also ashraf et al., (19) reported that the most prevalent orofacial manifestation of beta thalassemic patients was malocclusion, the severity of malocclusion increased with age, also reported other features incompetent lip and gingival pigmentation with least percentage than malocclusion. oxidative stress is a basic mechanism in βthalassemia major (βtm) pathological alternations. it has already been established that oxidative stress is increased in patients with iron overload. they initiate the process of autocatalytic free radical lipid peroxidation generating a large variety of potential genotoxic breakdown products, including alkoxyl radicals, peroxyl radicals and aldehydes, such as malonedialdehyde. the level of thiobarbituric acid reacting substance thiobarbituric acid– reacting substance in the investigated beta thalassemia major patients was raised by more than 100% (20). j bagh college dentistry vol. 27(2), june 2015 oro-facial manifestations oral diagnosis 96 the results showed increased in serum and saliva malondialdehyde levels in patients with beta thalassemia major and was significantly higher in thalassemic patients with periodontitis than that in the healthy subject and than that in thalassemic patients without periodontitis (p<0.001).the results of this study agree with naithani et al., (21) kattamis et al., (22) sonali et al. (23) who reported increased level of serum malondialdehyde in beta thalassemic patients. rai et al., (24) reported increased the level of malondialdehyde level in both serum and saliva of patients with periodontitis. khalili and biloklytska, (25) also revealed increased levels of malondialdehyde in saliva of patients with periodontitis. the polymorphonuclear leukocytes are the initial and the predominant defense cells produced during the host response to bacterial pathogens. the periodontopathogens along with their products induce the generation of free radicals. this reactive oxygen species generation may be responsible for the bone resorption, degradation of connective tissue. the over production of malondialdehyde at the inflammatory site can be related to the greater degree of oxidative stress in patients with periodontitis (26). the study showed increased in serum and saliva uric acid in patients with beta thalassemia major the results agree with aldudak et al., (27) reported elevated serum levels of uric acid and phosphate in βtm patients. the increased level of serum and saliva uric acid in thalassemic patients (with and without periodontitis) may be due to counteract the increased oxidative stress in those patients represented by the increased level of serum and saliva oxidative stress biomarker malondialdehyde. also deferoxamine therapy has been proved to be nephrotoxic and induce dose-dependent proximal tubular dysfunction by an unknown mechanism (28) . although transfusion therapy prolongs survival in beta thlassemia major, the absence of a physiological iron excretion mechanism leads to uneven accumulation of this metal in various body organs results in death, usually during the second decade of life ,so it's may be accumulated in kidney and cause renal dysfunction (29). the results showed that uric acid was significantly higher in thalassemic patients without periodontitis than that in other study groups. this was agree with many studies suggested decreased level of uric acid in saliva of patients with periodontitis like disease (30,31). references 1. weatherall dj, clegg jb. the thalassemia syndromes. 4th ed. malden, massachusetts: blackwell science; 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46: 467-70. 29. modell b, khan m, darlison m. survival in betathalassemia major in the uk: data from the uk thalassemia register. lancet. 2000; 355: 2051–2. 30. front e, laster z, unis r, gavish m, nagler rm. salivary biomarker analysis complementing regular clinical examination. biomark med 2013; 7(5): 701-8. 31. miricescu d, totan a, calenic b, mocanu b, didilescu a, mohora m, spinu t, greabu m. salivary biomarkers: relationship between oxidative stress and alveolar bone loss in chronic periodontitis. acta odontol scand 2014; 72(1):42-7. الخالصة . الھیموغلوبین من مكونات) الفا و بیتا(من فقر الدم الشدید والذي كان سببھ وجود خلل في نوعین من البروتین نموذج من مرض وراثيھوبیتا الثالسیمیا :الخلفیة مواد كیمائیة تؤخر بدء ھي مضادات االكسدة . الخالیا اتالفالى يمضادات االكسدة في النظام الخلوي مما یؤد/ألكسدةابین حالة اختالل التوازن وھ الشد التاكسدي تسجیل الظواھر كانت اھاداف ھذة الدراسة ھي .انواع االوكسجینات التفاعلیةتلعب دورا مھما في نظام دفاع الجسم ضد وأنھااو تبطئ معدل تفاعل اكسدة الدھون حامض الیوریكودوره في مرض بیتا ثالسیمیا وتقییم مضادات االكسدة malondialdehyde بیتا ثالسیمیا و تقییم عامل االكسدة المرضى لالوجھیة والفمویة .في دم ولعاب ھؤالء المرضى ، ثمانیة وعشرون مریضا یعانون من التھاب اللثة و ثالثون مریضا غیر مصابا بمرض البیتا ثالسیمیا كبرىشملت الدراسة ثمانیة وخمسون مریضا :الطرق ، ھر الوجھیة والفمویة سجلت سریریاالظوا .اللثة مع تسعة وعشرین شخصا سلیما اعمارھم متطابقة مع مرضى بیتا ثالسیمیا مصابین بالتھاب malondialdehyde جمیع االشخاصفي مصل ولعاب تم قیاسھا وكذلك حامض الیوریك. معدل . اطباق الشفتین عدم و للغشاء المخاطيسوء االطباق و وجھ القوارض و التصبغ البني ھي الظواھر الرئیسیة الوجھیة والفمویة : النتائج malondialdehyde في المصل واللعاب عالي جدا بكثیر لدى مرضى بیتا ثالسیمیا مع التھاب اللثة)(p<0.001 . معدل حامض الیوریك في المصل واللعاب ).p<0.001(ون التھاب اللثة عالي جدا بكثیر لدى مرضى بیتا ثالسیمیا بد malondialdehyde ، الزیادة في معدل مصل ولعاب والفمویة لدى مرضى بیتا ثالسیمیاسوء االطباق المظھر االكثر انتشارا بین المظاھر الوحھیة :االستنتاج . ة الشد التاكسديفي عملیالحاصل جھة االرتفاع ایشیر الى دور االكسدة في التسبب بمرض بیتا ثالسیمیا، حامض الیوریك یزداد لمو .، حامض الیوریك، سوء االطباقmalondialdehyde، ثالسیمیابیتا :الكلمات الرئیسیة nada f.doc j bagh college dentistry vol. 25(2), june 2013 evaluation of the effect restorative dentistry 31 evaluation of the effect of root canal preparation size and flaring on the depth of irrigant penetration (in vitro study) nada abdulmunem a. al-sabbagh, b.d.s. (1) hussain f. al-huwaizi, b.d.s., m.sc., ph.d. (2) abstract background: cleaning and shaping of root canals successfully requires high volumes of irrigation solutions that can only be applied to the apical third of root canal after enlargement with instrument, so the aim of this study was to evaluate and to compare the efficiency of maxi-i-probe (side-vented needle), in the amount of root canal irrigant penetration for five different master apical file sizes (maf) and four different degrees of coronal and middle thirds flaring. materials and methods: two hundred resin blocks with simulated root canals were used in this study and divided into 5 major groups (40 for each) based on the size of master apical files (#20, #25, #30, #35, and #40). each major group was subdivided into 4 subgroups depending on different sizes and depth of flaring (10 for each).the instrumentation and flaring techniques were used as following: 1. without flaring group, root canal shape resembles shape of the master apical k-file, 2. flaring i group, flaring done with gates glidden i for 2 mm coronally, 3. flaring ii group, flaring was done with gates glidden i for 4 mm coronally, gates glidden ii for 2 mm, 4. flaring iii group, flaring was done with gates glidden i for 6mm,gates glidden ii 4mm and gates glidden iii for 2 mm coronally. irrigation was done with max-i-probe gauge 28. results: by comparing the five different master apical file sizes at four different degrees of flaring, there was an increase in the amount of irrigant penetration with increase maf size, taper had more effect in small canals size and decreased with further enlargement of master apical file size until no benefit was achieved in large canals size. conclusions: it was shown that, max-i-probe had a limited amount of irrigant entrance. flaring was more effective in small canals than the larger canals in an amount of irrigant entrance; increasing maf size was effective in an increase amount of irrigant entrance. key words: irrigant penetration, side-vented needle, flaring, canal size. (j bagh coll dentistry 2013; 25(2):31-35). introduction irrigation has a central role in endodontic treatment. however, there is no agreement concerning the ideal apical width of preparation. on the other hand, preparing small apical dimensions is recommended for prevention of instrumentation errors such as apical transportation and to preserve as much radicular dentin as possible. there is conflicting evidence regarding the antimicrobial efficacy of small (ie,size #20) apical preparations .(1) it has been reported that increasing the taper of the root canal might result in improved debridement during irrigation. others have also reported that there is no significant difference between tapered and minimally tapered root canals in terms of antimicrobial efficacy of both syringe irrigation and apical negative pressure irrigation.(2) there are a number of studies examining physical factors that influence the degree of irrigant penetration and its effectiveness, including canal shape and size, volume and pressure of irrigant, the type, size, and insertion depth of the irrigation needle.(3). (1) msc student, dep. of conservative dentistry, college of dentistry, university of baghdad (2) professor, dep. of conservative dentistry, college of dentistry, university of baghdad the needles are designed to dispense the irrigant through their most distal end or laterally through side-vented channels. the latter design has been proposed to improve the hydrodynamic activation of an irrigant and to reduce the chance of apical extrusion.(4) different results have been reported regarding the effectiveness of minimum enlargement size in the apical third of canals to achieve proper penetration of irrigants card et al.(5) materials and methods two hundred clear acrylic resin blocks with simulated root canals were made to assess the instrumentation, irrigation, as well as standardization. the blocks were constructed by embedding 13 mm of a silver point of a particular size which was coated with a separating medium between two pieces of sheet wax which had been cut in square shape and had a dimension of 17 mm in length, 10 mm in width and 1.5 mm in thickness. it was converted by dewaxing and flasking to a clear acrylic block with a simulated canal of the corresponding size of the silver point and 13 mm in length which had been checked by the same size of stainless steel k-file to ensure its patency before starting the instrumentation. j bagh college dentistry vol. 25(2), june 2013 evaluation of the effect restorative dentistry 32 the simulated root canals were divided into five groups (40 for each) depending on the size of master apical file (#20 (a), #25(b), #30(c), #35(d), and #40(e)) and then each group was subdivided into four subgroups depending on different flaring sizes and depths (10 for each) (1) without flaring group: canal was not instrumented with gates glidden drill. (2) flaring i group: flaring with gates glidden i for 2mm. (3) flaring ii group: flaring with gates glidden i for 4mm and gates glidden ii for 2 mm. (4) flaring iii group: flaring with gates glidden i for 6mm, gates glidden ii 4mm and gated glidden iii for 2 mm. to achieve standardized position of the block throughout the whole procedure, the mold was fixed by a bench vice, the straight hand piece held by surveyor for instrumentation with gates glidden to avoid lateral movement of the hand then the simulated canal prepared with gates glidden drills in clockwise direction, one penetration, and each drill was used for five simulated canals and then discarded, the drill was wiped after each use by clean sponge stand to remove resin debris. 1500 rpm was the most suitable speed that was found for instrumentation of the resin canal. after each gates glidden drill use, irrigation with 2 ml of distilled water was done by using max-i-probe gauge 28 with syringe followed by negotiation with stainless steel k-file to ensure canal patency. to achieve standardization, the without flaring group was also irrigated with 2 ml of distilled water after checking the patency with a corresponding size of master apical file. to achieve standardized final irrigation the syringe was fixed in the center of a plastic custom made table by adhesive material which was used to hold the applying load, then all the assembly was held by surveyor and the block with its mold was held by bench vice below the syringe, by this way the testing irrigation needle which has a diameter of 0.36 mm could be inserted in the simulated canal in the desired depth which was 4 mm from the coronal orifice (9 mm from apex), as close as possible to the longitudinal axis of the canal using a stopper, to be away from the constriction area of the smallest canal in our study (without flaring group of maf #20).the needle was secured in the same position for all measurements. a container was placed below the block to collect the accumulated out-flowing irrigant.(6), the needle was centered within the canal and was immovable (7). final irrigation was done by applying load of 4 kg over the plastic table as a standardized pressure; irrigation was done by using 2 ml. of diluted dark blue dye (30 ml. of ink diluted by 200 ml. of distilled water) for eight seconds with max-i-probe gauge 28 and 5 ml. disposable syringe. by this way we obtained standardized flow rate for all the samples which was 0.25 ml./sec according to the equation flow rate = volume of fluid / time (8). measurement was done immediately after final irrigation with dye to avoid any change in the reading value by using a travelling microscope which is an instrument for measuring length with a resolution typically in the order of 0.01mm, measuring the distance between the coronal canal orifice and the end of the dye in the simulated root canal and read the measurement by the vernier of the microscope. the data were collected and analyzed using spss (version 18) for statistical analysis. one-way analysis of variance (anova) and least significant difference test (lsd) was used to determine whether there is a statistical difference among the groups and within the group at different levels with significance level of p≤ 0.05. results both the highest and the lowest mean values for the amount of entrance depth of irrigant were seen at the maf 40 flaring iii and maf 20 without flaring respectively. the rest mean values for the other study groups of mafs sizes and flaring degrees were fluctuated between these two values(table 1 and figure 1) table 1: descriptive statistical analysis for the amount of entrance of root canal irrigant in five different master apical file sizes and four different degrees of flaring. groups n mean ±sd 20 a1 10 4.632 mm 0.218 a2 10 5.329 mm 0.553 a3 10 5.943 mm 0.529 a4 10 6.830 mm 0.403 25 b1 10 5.332 mm 0.527 b2 10 5.401 mm 0.734 b3 10 6.197 mm 0.518 b4 10 7.689 mm 0.398 30 c1 10 6.481 mm 0.304 c2 10 6.689 mm 0.362 c3 10 6.727 mm 0.670 c4 10 7.704 mm 0.491 35 d1 10 7.582 mm 0.548 d2 10 7.617 mm 0.618 d3 10 7.840 mm 0.443 d4 10 8.247 mm 0.260 40 e1 10 7.920 mm 0.415 e2 10 7.980 mm 0.463 e3 10 8.318 mm 0.721 e4 10 8.427 mm 0.619 j bagh college dentistry vol. 25(2), june 2013 evaluation of the effect restorative dentistry 33 figure 1: bar chart showing means of the depth of entrance of root canal irrigant at different master apical file sizes and four different degrees of flaring. the comparison among the five different sizes of master apical file in the amount of entrance depth of root canal irrigant. to compare five maf sizes at each flaring degree. analysis of variance (anova test) was performed to identify the presence of statically significant differences for the amount of entrance depth of irrigant. high significant differences were found at all groups (table 2). table 2: anova test for the amount of entrance depth of root canal irrigant among the five different maf sizes at each degree of flaring. degree of flaring anova sum of squares df mean of square f p sig. without flaring between groups 79.800 4 19.95 111.883 0.000 hs within groups 8.024 45 0.178 total 87.824 49 flaring i between groups 59.996 4 14.99 47.613 0.000 hs within groups 14.167 45 0.315 total 74.172 49 flaring ii between groups 42.792 4 10.69 31.191 0.000 hs within groups 15.434 45 0.343 total 58.226 49 flaring iii between groups 15.533 4 3.883 191.123 0.000 hs within groups 9.138 45 0.203 total 24.670 49 the comparison among four different degrees of flaring in the amount of entrance depth of irrigant. the mean values and standard deviation for the amount of entrance depth of root canal irrigant in four different degrees of flaring are shown in (figure 1) and (table 1). anova test was performed to identify the presence of statistically significant differences for the amount of entrance of irrigant at four degrees of flaring. high significant and significant differences were found at all groups except at maf size 40 which had a non significant difference (table 3). table 3: anova test for the amount of irrigant entrance at different flaring degrees within the same size of master apical file. groups of mafs sum of squares df mean square f p sig. size 20 between groups 26.131 3 8.710 43.732 0.000 hs within groups 7.170 36 0.199 total 33.302 39 size 25 between groups 36.008 3 12.003 38.568 0.000 hs within groups 11.203 36 0.311 total 47.211 39 size 30 between groups 8.964 3 2.988 13.064 0.000 within groups 8.234 36 0.229 total 17.198 39 size 35 between groups 2.806 3 0.935 3.946 0.016 s within groups 8.533 36 0.237 total 11.339 39 size 40 between groups 1.862 3 0.621 1.922 0.144 ns within groups 11.631 36 0.323 total 13.493 39 8.710 discussion in this study five different master apical file (maf) sizes were used and four different degrees of flaring were done for each size and compared for their influence on irrigant entrance to the apical area. the results showed that no size and flare was able to allow the irrigant to reach the most apical area, this might be due to the safe irrigation of the needle, long distance between apical area, the tip of the needle and the size and shape of the canals. this agree with hsieh et al.(9) who found that at 6 or 9 mm from the apex no irrigation was able to flow into the root apex with any of three needle sizes (23,25,27) in the canals size (25,30,35,40) and even at 9 mm in canals size (45,50). sedgley et al.(10) found that the mechanical efficacy of 6 ml of irrigant in reducing intracanal bacteria was significantly greater when delivered 1 mm compared with 5 mm from wl. the result was also in coincidence with boutsioukis et al. (11) who stated that irrigant j bagh college dentistry vol. 25(2), june 2013 evaluation of the effect restorative dentistry 34 replacement reached the wl only when the sidevented needle was placed at 1 mm from w.l. the main flow appeared to spread laterally around the needle whilst following a curved path around the needle tip with limited apical penetration and was finally directed towards the canal orifice.(7) the failure of irrigant replacement might be due to the effect of vapor lock in the closed system. this was in consistence with tay et al.(12) who found that the presence of an apical vapor lock in a closed system canals had an adverse effect on debridement efficacy. with regard to canal size the results had a reverse opinion with khademi et al. (3) who found that the minimum instrumentation size needed for penetration of irrigants to the apical third of the canal was size #30 file. their study found that it was unnecessary to remove dentine in the apical part of the root canal when suitable coronal taper is achieved. this might be due to the difference in taper of the instruments which had been used, with tapers of 0.02 and flaring only the coronal and the middle thirds of the canals in our study versus continuous taper of 0.06 in their study comparison among different sizes of master apical file in the amount of irrigant entrance. by comparing the five different master apical file sizes at four different degrees of flaring, there was an increase in the amount of irrigant penetration with increase in master apical file size. this finding was in coincidence with albrecht et al.(13) who found that, there was significantly greater percentage of remaining debris in the apical areas of the small canals preparation (size 20) compared to larger canals preparation (size 40). our finding was also in agreement with nguy and sedgley(14) and with falk and sedgley (15) who found that the efficacy of irrigation is significantly reduced in prepared canals to size 36 in comparison to size 60 profile .04 series 29 rotary ni-ti files, but no advantage gained by further enlargement to size 77. the result was in contrast with zakaria (16) who found that the canal size had no effect on the penetration depth of endodontic irrigant. this might be due to step back techniques used in all his canals sizes (20-40). there was an increase in the amount of irrigant entrance but the difference was statistically non-significant between size 35 and size 40 and this might be due to small amount of percent of increase in d0 diameters between them which was 14%, this was in consistence with brunson et al.(17) who found that the increase in size from iso #40 to iso #45 resulted in a small amount of irrigant gained to the working length. there was an increase in the amount of irrigant entrance but statistically was nonsignificant between a2 and b2 and between a3 and b3. our explanation is this might be due to the effect of gates glidden in canals size 20 (a) was more than in canals size 25 (b) and that was revealed by comparing the width of the canals in these sizes. in (a) the coronal orifice of the canal was 0.46 mm compared to 0.51mm in (b) so the effect of gates glidden i (which has a diameter 0.50mm) was more in the (a) than in (b), also in flare ii the role of gates glidden i was more in (a) than in (b), the width of the canal at 4mm was 0.40 mm in (a) and 0.45 mm (b) while the effect of gates glidden ii was good for both. this was obviously seen by comparing the mean difference between a1 and a2 (without flaring and flaring i groups) which was -0.697 while between b1 and b2 the mean difference was 0.069, while between a1 and a3 (without flaring and flaring ii groups) the mean difference was -1.311, while between b1 and b3 was -0.865 which revealed the effect was for both but more for (a) than (b). there was an increase in the amount of irrigant penetration but statistically the difference was non-significant between size b4 and c4. our explanation for that might be due to effects of the three gates glidden drills i, ii and iii, gave same geometrical shape at coronal and middle thirds of the canals which was 0.50mm at the 6th mm, 0.70mm and 0.90mm at the 4th mm and the coronal orifice respectively provided a nonsignificant difference statistically between these two canals sizes. this finding was similar to the finding of albrecht et al.(13)who found that debris was more effectively removed by using .04, .06, .08 profile gt instruments when the apical preparation size 40 compared with size 20 apical preparation. when a taper of 0.10 can be produced at the apical extent of the canal, there was no differences in debris removal between size 20 and 40. comparison among different flaring degrees on the amount of apical irrigant entrance. the results showed that the effect of taper was more in small canals size and decreased with further enlargement of master apical file size until no benefit was achieved in large canals size. that proves highly significant differences observed among various flaring degrees at maf 20 (a) and non-significant differences observed among various flaring degrees at maf 40 (e). this result was similar to the finding of albrecht et al.(13) who reported that when the canals were prepared with gt files size 20, the increase in taper led to a better debridement, but when the j bagh college dentistry vol. 25(2), june 2013 evaluation of the effect restorative dentistry 35 apical preparation size was 40 taper had no influence on debris removal. at maf 25 (b) non-significant difference was observed between without flaring group and flaring i group. this was due to the small size of gg i which is 0.50 mm in comparison to the diameter of the coronal orifice of the canal and its small amount of entrance as we mentioned formerly. at maf 30 (c), non-significant difference was found among all the groups of various taper except c4 which had highly significant difference with all, and this might be due to the greater amount of the entrance of the gg and the amount of taper obtained which ends with 0.90 mm coronaly at c4 .at maf 35 (d) there was no significant difference among all its group of flaring except between (d1 and d4) and between (d2 and d4). this might be due to the same explanation as mentioned with maf size 30the result was similar to the result of lee et al.(18) who found that the debris score for the size 20, 0.04 taper groups was significantly higher than that for the size 20, .06 and the size 20, .08. however, no significant difference was found between size 20, .06 and the size 20, .08 groups. the results were also in agreement with arvaniti and khabbaz (19) who found that, the root canal taper can affect its debridement only when final instrument size is smaller than 30. he also found that root canal preparation to apical size 30 and tapers 0.04, 0.06 or 0.08 had no statistically significant differences were found between groups of different taper. the only difference with our results was at flaring iii which had significant differences with the other subgroups of the related size of maf and that might be due to the difference in the taper used (gt with continuous taper in their study versus gg with coronal and middle thirds taper in our study), the results were also in agreement with al–huwaizi(20) who found that additional flaring of the root canal did not dramatically increase the irrigant, and with hockett et al.(2)who reported that there was no statistically significant difference in colony forming unit between sizes #35 and #45, nor between tapered and non-tapered preparation. references 1. mcgurkin-smith r, trope m, caplan d, sigurdsson a. reduction of intracanal bacteria using gt rotary instrumentation, 5.25% naocl, edta, and ca(oh)2.joe 2005;31:359–63. 2. hockett jl, dommisch jk, johnson jd, cohenca n. antimicrobial efficacy of two irrigation techniques in tapered and nontapered canal preparations: an in vitro study. joe 2008; 34:1374-7. 3. khademi a, yazdizadeh m, feizianfard m. determination of the minimum instrumentation size for penetration of irrigants to the apical third of root canal systems.joe 2006; 32:417– 20. 4. vinothkumar ts, kavitha s, lakshminarayanan l, et al. influence of irrigating needletip designs in removing bacteria inoculated into instrumented root canals measured using single-tube luminometer. joe 2007; 33:746–8. 5. card sj, sigurdsson a, orstavik d, trope m. the effectiveness of increased apical enlargement in reducing intracanal bacteria. joe 2002; 28:779–83. 6. boutsioukis c lambrianidis t, kastrinakis e, bekiaroglou p. measurement of pressure and flow rates during irrigation of a root canal ex vivo with three endodontic needles. int endod j 2007a; 40: 504–13. 7. boutsioukis c, lambrianidis t, kastrinakis e. irrigant flow within a prepared root canal using various flow rates: a computational fluid dynamics study. int endod j 2009; 42:144–55. 8. hughes wf, brighton ja. fluid dynamics. 3rd ed. new york: mcgraw-hill; 1999:2–6, 34–61, 118–23, 2456. 9. hsieh yd, gau ch, wu sfk, shen ec, hsu pw, fu e. dynamic recording of irrigating fluid distribution in root canals using thermal image analysis. int endod j 2007; 40:11–17. 10. sedgley cm, nagel ac, hall d, applegate b. influence of irrigant needle depth in removing bioluminescent bacteria inoculated into instrumented root canals using real–time imaging in vitro. int endod j 2005; 38(2): 97104. 11. boutsioukis c, lambrianidis t, verhaage b, versluis m, kastrinakis e, wesselink pr, van der sluis lwm. the effect of needle-insertion depth on the irrigant flow in the root canal: evaluation using an unsteady computational fluid dynamics model. joe 2010b; 36:1664–8. 12. tay fr, gu l, schoeffel gj, wimmer c, bs, susin l, zhang k, dds, arun sn, kim j, dds, looney sw, pashleydh. effect of vapor lock on root canal debridement by using a side-vented needle for positivepressure irrigant delivery. joe 2010;36:745-50. 13. albrecht lj, baumgartner jc, marshall jg. evaluation of apical debris removal using various sizes and tapers of profile gt files. joe 2004; 30:425-8. 14. nguy d, sedgley c. the influence of canal curvature on the mechanical efficacy of root canal irrigation in vitro using real-time imaging of bioluminescent bacteria. j endod 2006; 32:1077–80. 15. falk kw, sedgley cm. the influence of preparation size on the mechanical efficacy of root canal irrigation in vitro. joe 2005; 31:742-5. 16. zakaria na. the effect of canal size on the penetration depth of endodontic irrigants. al-rafidain dent j 2006; 6:84-87. 17. brunson m, heilborn c, johnson dj, cohenca n. effect of apical preparationsize and preparation taper on irrigant volume delivered byusingnegative pressure irrigation syst em. joe 2010; 36(4):721-4. 18. lee s-j, wu m-k, wesselink pr. the efficacy of ultrasonic irrigation to remove artificially placed dentine debris from different sized simulated plastic root canals. int endod j 2004b; 37: 607–12. 19. arvaniti is, khabbaz mg. influence of root canal taper on its cleanliness: a scanning electron microscopic study. joe 2011; 37:871-4. 20. al-huwaizi hf. the degree of irrigant entrance to the root canal by the use of different instrumentation techniques. j college dentistry 2004; 16:11-3. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 3 (2022), issn (p): 1817-1869, issn (e): 2311-5270 42 research article 12months color stability of direct resin composite veneers in anterior teeth: clinical trial omar faez abdulateef 1, 2*, nevin çobanoğlu 1 1department of restorative dentistry, college of dentistry, university of selcuk, turkey. 2fallujah specialist dental center, al-anbar general health directorate, ministry of health, iraq *correspondence: theincisor2004@yahoo.com abstract: background: this clinical trial aims to evaluate the color changes of direct resin composite veneer (dcv) restorations based on spectrophotometric analysis of 4 different types of resin composites between the baseline immediately after polishing and after one year of follow-up. materials and methods: 28 patients were assessed for eligibility for participation, aged between 18 and 38 years old, who indicated for dcv restorations in anterior maxillary teeth were considered for participation in this study. in total, 25 patients who met the inclusion criteria were selected (6 males and 19 females, mean age: 20.9 at the time of restoration placement), and 3 patients were excluded. participants were divided into four groups based on the type of composite resin used for restorations. group 1 nanohybrid ips empress direct (ivoclar vivadent)](ips) (13 restorations/6 patients), group 2 microfilled [essentia (gc cooperation japan)](es) (14 restorations / 7 patients), group 3 supra-nano filled [ estelite ∑ quick (tokuyama, tokyo, japan)](eq) (17 restorations / 7 patients) and group 4 nanofill [filtek ultimate (3m espe)](fu) (13 restorations / 5 patients). baseline color measurements were performed with a spectrophotometer immediately after finishing and polishing (baseline), and after one year of recall, color change (δe) from baseline values and after one year of follow-up of dcvs were calculated according to cielab color coordinates. for this, a silicone mold was fabricated for each patient and used as a guide for each measurement to standardize the site of the readings. statistical analysis of the data was applied using the kruskal-wallis test with dunn-bonferroni posthoc test after controlling the distribution of data in terms of normality with the shapiro wilk test. results: at the end of one year,25 participants(57restorations) were followed up. the mean δe of ips, eq, and fu composites were higher than the es composite resin, but there was no statically significant difference between all types of composites (p> 0.05). there was no statistically significant difference in the mean δl* between any types of composite resin (p> 0.05). there was a significant change in δa* and δb* after a one-year recall for all the types of dcv restorations (p < 0.05). conclusion: after one year of follow-up, the spectrophotometer measurements of direct resin composite veneer restorations, it was concluded no difference between the mean δe of es, ips, fu, and eq resin composite. es (microfilled hybrid) showed a lower mean δe value compared to the other groups. all groups of resin composite showed color changes within clinically acceptable levels after a one-year follow-up. keywords: direct composite veneer, color changes, spectrophotometer. introduction in the last decades, there was an era in bonding restorations especially composite resins. the development in the mechanical and optical properties of composite resin has enabled it to become one of the most used dental materials in dental practices in both anterior and posterior restorations (1). with the evolution of composite resin technology, direct anterior composite restorations, including veneers, became an economical and visually pleasing solution compared to more complex restorations (2, 3). the attractiveness and popularity of composites are easy to explain as these restorations have excellent received date: 1-5-2022 accepted date: 20-6-2022 published date: 15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license. (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbcd .v34i3.3216 mailto:theincisor2004@yahoo.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3216 https://doi.org/10.26477/jbcd.v34i3.3216 j. bagh. coll. dent. vol. 34, no. 3. 2022 abdulateef and çobanoğlu 43 esthetic potential, excellent prognosis, and a reasonable fee (4). there are several advantages of composite restorations. the first one is related to their adhesive properties, the minimal preparation size, the reinforcement of remaining teeth and the esthetic appearance (5). many esthetic clinical cases in the anterior region can be treated with direct composite restorations such as tooth discoloration, diastemata, extensive fractures, misaligned teeth, or dental caries lesions which may cause significant impairment in esthetic appearance and smile harmony, causing an impact on the quality of life (5, 6). it has been frequently cited that direct resin composite veneers (dcv) are a more conservative option for some clinical cases planned for porcelain veneers (7, 8). despite these developments, several disadvantages have been recorded clinically and in in-vitro studies that affect the performance of the composite. these disadvantages are represented mainly by discoloration of restoration, which primarily affects the satisfaction of patients (9). color stability can be the difference between success and failure. composite resin discoloration is multifactorial, including factors such as intrinsic discoloration and extrinsic staining. nevertheless, a correlation between color (discoloration) and degree of conversion was established, with incomplete polymerized composite resins showing reduced mechanical properties and greater discoloration susceptibility (10, 11). therefore, this clinical study aimed to investigate the color changes of direct anterior resin composite veneer restorations after a one-year follow-up based on a spectrophotometric analysis of four different types of composites. the null hypothesis of this study was that there would be no difference in the color changes among resin composite materials (microfilled hybrid, nanohybrid, nanofill, and supra nanofill composite resins) after one year of follow-up. materials and methods this clinical trial evaluated the δe value and color coordinates (l*, a*, and b*) of dcv restorations of 4 different types of composite resin after a one-year follow-up using a spectrophotometer. ethics committee approval for this study was obtained from the selcuk university faculty of dentistry clinical research ethics committee (ethics committee decision date: 26.06.2018 / no:06). in this study, 28 patients were assessed for eligibility for participation, aged between 18 and 38 years old, who applied to selcuk university faculty of dentistry, department of restorative dentistry with aesthetic complaints in the anterior region between january 2017 and december 2018 and indicated for dcv restorations were considered for participation in this study. in total, 25 patients who met the inclusion criteria were selected (6 males and 19 females, mean age: 20.9 at the time of restoration placement), and 3 patients were excluded due to either failing to meet the inclusion criteria or declining to come for follow-up visits. additionally, participants selected for this study were students at selcuk university (undergraduate and postgraduate ) and were able to come for recall visits. the selected patients received a total of (57 ) dcv restorations in anterior maxillary teeth, and each patient received 2-4 restorations from the same type of resin composite. the following inclusion criteria were used to evaluate and enroll potential participants: individuals at least 18 years old with fracture, diastema closure, peg-shaped laterals, congenitally missing lateral incisors ( in cases of canine transformation to lateral incisors ), enamel hypoplasia disorders, misaligned anterior tooth and discolored tooth that resist the internal endodontic bleaching, and able to read and sign the informed consent document, physically and psychologically able to tolerate the procedure. furthermore, patients who were selected for the study had full dentition and normal occlusion without generalized periodontal disease, as verified by the clinical and radiographic records. patients were excluded when severe untreated bruxism, active caries, poor oral hygiene and heavy smokers. in this study, 4 different composite resins that contain different chromatic shades were used. an j. bagh. coll. dent. vol. 34, no. 3. 2022 abdulateef and çobanoğlu 44 experienced dentist restored all the dcv restorations using the different restorative materials. the teeth of the patients included in the study were divided into 4 groups according to the type of composite to be applied; group 1 nanohybrid [ ips empress direct (ivoclar vivadent)] (ips) (13 restorations/6 patients), group 2 micro filled [essentia (gc cooperation japan)] (es) (14 restorations / 7 patients), group 3 supra-nano filled [ estelite ∑ quick (tokuyama, tokyo, japan)](eq) (17 restorations / 7 patients) and group 4 nanofill [filtek ultimate (3m espe)] (fu) (13 restorations / 5 patients). the self-etch 2-step adhesive system clearfil se bond (kuraray, osaka, japan) with selective etching to the enamel was used as an adhesive system, restorations were performed using an anatomical layering technique and were light-cured using an led polymerization unit valo (ultradent products inc, south jordan, ut, usa). the restorations were finished and polished immediately in the same visit underwater cooling using fine diamond burs, finishing and polishing discs (opti disc, kerr corporation), and aluminum oxide strips (hawe™ finishing and polishing strips kerr corporation) for the interproximal surfaces. they were followed by using enhance (dentsply/caulk, milford, delaware) or onegloss (shofu, kyoto, japan), then using carbide brushes (astrobrush, ivoclar vivadent, liechtenstein), and lastly, synthetic and natural foam (dentsply/caulk, milford, delaware) with extra-fine polishing paste (prima-gloss; dentsply, latin america), were used for the natural gloss until all restorations were considered clinically acceptable. after polishing, there were no dietary restrictions or cleaning instructions that have been informed for patients to do during the follow-up time period. therefore, the different dietary consumptions or cleaning materials that the patients may use could impact the color stability and the results of the current study. color measurement was performed with a spectrophotometer vita easyshade v (vita zahnfabrik, bad säckingen, germany) immediately after finishing and polishing (baseline) and after one year of recall, the equipment was calibrated before each reading, and a single trained investigator made all the color measurements under the same ambient light conditions. the active tip of the spectrophotometer was placed at the middle third of the buccal surfaces of composite veneer restorations of each tooth. for this, a silicone mold was fabricated for each patient and used as a guide for each measurement to standardize the site of the readings. the color of all restorations was measured three times, and their average values were taken. color measurement was performed from the buccal surfaces of restorations after drying by using air from a triple syringe and l*, a*, and b* were recorded. where l* is a measure of the lightness, a*is a measure of redness (positive direction) or greenness (negative direction), and b* is a measure of yellowness (positive direction) or blueness (negative direction). the δe value was calculated for each restoration using the following formula δeab* = [(δl*)2 + (δa*)2 + (δb*)2]1/2 where, δl*, δa*, δb* are the differences in l*, a* and b* values of restorations immediately after finishing and after a one-year recall. statistical analysis the statistical analyses were performed using spss for windows 26.0 (spss, chicago, il, usa). in the statistical analysis of δe values of composite veneer restorations, the descriptive statistics are frequency, percentage, and simple chart bars for demographic data such as age and gender and mean and standard deviation (sd) for quantitative data. while the inferential statistics is the kruskal-wallis test with dunn-bonferroni posthoc test was used after controlling the distribution of data in terms of normality with the shapiro wilk test. results j. bagh. coll. dent. vol. 34, no. 3. 2022 abdulateef and çobanoğlu 45 the initial color measurements (baseline) were recorded as l, a, and b for the subject's teeth, and they are no significant differences among resin composites using the kruskal-wallis test, whereas p values for a, l and b are 0.234,0.102, and 0.546 respectively which mean the correct standardization and randomization of shades between subjects to get rid of bias. color change (δe*) of the dcv restorations after one year of the recall are shown in table 1. also, changes in δl*, δa*, and δb* of dcv restorations after one year were illustrated in table 2. color changes of the different composite resin materials in the range of 0.464 -8.95 δe* unit. after one year, the mean color change δe in eq composite (4.2 ± 2.41) was higher than the mean values of color change in both fu (4.22 ± 3.07) and ips (4.1 ± 1.6) composite resin. at the same time, δe of ips, fu, and eq composites were higher than the es (2.77 ± 2) composite resin, but there was no statically significant difference between all types of composites. (p value=0.280). table 1: descriptive and statistical test of color change δe (mean± sd) among composite resin groups after 1 year. *different superscript small letters refer to statistically significant differences between rows (p< 0.05). δl* (brightness) values a positive δl* indicates that the restorations became lighter, whereas a negative δl* indicates that the restorations became darker. all the types of composites showed negative δl* after a one-year recall. there was no statistically significant difference in the mean δl* between any types of composite resin (p=0.761). in all four types of composites used in this study, the maximum change in mean δl* was seen in fu composite (-2.41 ± 3.74), while the minimum change in mean δl* was seen in eq composite resin (-1.3 ± 3.3). δa * (change along the red-green axis) values a negative δa* indicates a shift toward green color, whereas a positive δa* indicates a shift toward red color). es, eq and fu composite resin showed positive δa*, and ips composite showed negative δa*. there was a statistically significant difference in the δa* values between all types of dcv restorations after a one-year recall (p =0.041). after a one-year recall, the maximum change in δa* was seen in fu (mean δa*, 0.49 ± 0.89). there was a statistically significant difference in the δa* values between ips and 3m. (p=0.015). δb* (change along the yellow-blue axis) values after a one-year recall, there was a statistically significant difference in the δb* values between all types of composite resin materials (p =0.000). a positive δb* indicates a shift towards yellow color, while a negative δb* denotes a shift toward blue color. ips and es composite resin showed negative a mean δb*, while eq and nanofill composite resin showed a positive mean δb*. after a one-year recall, the maximum change in δb* was seen in the eq composite (mean δb*, 2.65 ± 2.1). there was a statistically groups number of restorations δe ± sd ips 13 4.109 ± 1.63a es 14 2.778 ± 2.00a fu 17 4.286 ± 2.4a eq 13 4.220 ± 3.07a j. bagh. coll. dent. vol. 34, no. 3. 2022 abdulateef and çobanoğlu 46 significant difference in the δb* values between ips and toku (p=0.010) and between ips and 3m (p=0.000). table (2). mean± sd values of color coordinates of different composite resin groups after 1-year recall. *different superscript small letters refer to statistically significant differences between rows (p< 0.05). discussion in vitro studies contribute to clinical evaluations by enabling the development and evaluation of restorative materials. although an attempt is made to imitate clinical conditions, this does not accurately reflect the clinical performance of the materials due to variable parameters in the mouth. therefore, wellplanned, controlled clinical trials are necessary to evaluate newly produced materials' clinical performance and compare different restorative materials. this clinical study aimed to evaluate the color changes of direct resin composite veneer restorations of 4 types of resin composites; nanohybrid, microfilled, supra-nano filled and nanofill, after one-year follow-up by using a spectrophotometer. the null hypothesis of this study was accepted because there was no significant difference in color changes among resin composite materials tested in this study. the discoloration of composite resin can be evaluated either by visual or instrumental techniques. the color evaluation by visual observation may not be a reliable manner due to inconsistencies inherent in color perception and specification amongst observers (12-14). instrumental techniques for color measurement include colorimetry, spectrophotometry, and digital image analysis, of which spectrophotometry has been reported to be reliable technology in dental material studies. the human eye cannot detect δe values of less than 1.5, although this value is measurable with the help of a spectrophotometer (15). despite the accuracy of instrumental evaluation of color changing of different restorative materials, the visual assessment stilled the dependable method for the clinical estimation; this is due to incompatibility between both visual and instrumental evaluations; this finding is in agreement with the suggestion of douglas et al.(2007) that reported future in vivo studies related to color stability by using intraoral spectrophotometer should follow the thresholds of color perceptibility (δe* of 2.6) and acceptability (δe * of 5.5)(16). at the same time, sabatini (2012) reports in their study that the concept regarding the color change (δe) that exceeds 3.3 clinically unacceptable applies to laboratory conditions and cannot be extrapolated as a threshold for ‘‘clinical unacceptability’’ (17). according to these findings, in this study, the mean values of δe between the baseline and after one year of all resin composite types were at acceptable levels. type of composite δl*± sd δa*± sd δb*± sd ips -2.03± 2.9a -0.30 ±0.60a -1.56 ±2.1a es -1.58 ± 2.7a 0.1 ±0.54ab -0.02±1.3ac fu -2.4 ± 3.7a 0.49 ±0.89b 0.93 ±2.55bc eq -1.3 ± 3.3a 0.35 ± 0.75ab 2.65 ±2.10b j. bagh. coll. dent. vol. 34, no. 3. 2022 abdulateef and çobanoğlu 47 the δe of these restorations were calculated according to cie l*a*b* color system. it describes the color based on human perception and designates it according to 3 spatial coordinates, l*, a*, and b*. l* represents the brightness (value) of a shade, δa* represents the amount of red-green color, and δb* represents the amount of yellow-blue color. in accordance with several studies, parameters l* and b* were responsible for the most abundant of the observed changes, whereas changes to the a* parameter were the least to the overall color change and were even regarded negligible (18-21).in the current study, the mean (δl*) of all types of the composite was negative that indicating the lightness decreased in all materials and became darker; this is in agreement with results from previous in-vitro studies about the color stability of composite resin, which have shown a decrease in the l*. the decrease in l* values may be due to the presence of unreacted carbon double bonds that occur according to the degree of conversion, making the composite more susceptible to degradation (18, 19), which also alters the refractive index by a scattering pattern leading to change in the opacity of the composite (19-21). mean δa* shifted to the red direction for all composite materials except ips shifted toward the green. mean δa* shifted to the red direction for all composite materials except ips shifted toward the green. the increased redness demonstrates the influence of amine-based accelerators in the resin composites; since all amines are known to form by-products during photoreaction, which tend to cause yellow to red-brown discolorations under the influence of light or heat (22). while mean δb* values of fu and eq showed positive mean and shifted to yellow, the es showed slightly shifting toward blue while ips shifted toward blue. this difference in the δb* values may be due to the type of photoinitiators used in their composition; cq in the resin leads to an undesirably yellowish effect in the final cured resin-based material. additionally, cq/amine percentage affects the color change of composite resin, as a more significant yellowing effect is expected with a higher amine rate because the excess of the amine has excellent potential for darkness due to oxidative reactions (23, 26). the mean δa*of ips shifted toward the green, while the mean δb* value of ips showed shifting toward blue; the differences between ips and other resin composite groups may be because it was based on a different photoinitiator lucirin that eliminated the amine group (21, 23, 24). in the current study, the restorations were finished and polished under cooling water; finishing and polishing under dry or wet conditions remained a controversial topic. it is recommended to polish the resin composite under water coolant to reduce the detrimental effects of dry finishing and polishing on the interface between the tooth and adhesive bond; interestingly, it also affects the bond between the particles and the surrounding matrix of the resin composite (25). aydın et al. (2022) found in their in-vitro study that wet and dry use of polishing systems showed similar color changes on the composite resins used in their study (26). this study presents some limitations, such as the small number of patients and restorations. additionally, a one-year evaluation of resin composite color changes is a short-term follow-up evaluation time, and this is one of the limitations of this study. split-mouth study designs can decrease most inter-patient variability, such as oral hygiene, diet, brushing habits and other habits that affect the color stability of resin composite restorations. the possible patient loss is a disadvantage of split-mouth designs since more restorations than one would be lost when a patient did not come for a follow-up appointment. although this study was not designed as split-mouth, and the variables between patients were ignored, the patients not fulfilling the inclusion criteria were excluded from the study. further clinical studies are 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integration of class iv composite restorations. aust dent j. 2012;57(4):446-452. 24. ruyter i, nilner k, möller b. color stability of dental composite resin materials for crown and bridge veneers. dent mater. 1987;3(5):246-251. 25. kaminedi rr, penumatsa nv, priya t, baroudi k. the influence of finishing/polishing time and cooling system on surface roughness and microhardness of two different types of composite resin restorations. j int soc prev community dent. 2014;4(suppl 2): s99. 26. aydın n, karao˘ glano˘ glu s, kılıçarslan ma, oktay ea, ersöz b. effect of wet and dry polishing conditions by two finishing and polishing systems on the surface roughness and color changes of two composite resin restoratives: an in vitro comparative study. j adv oral res. 2022;13(1):127-134. شهًرا من ثبات اللون لقشرة مركَّبة من الراتينج المباشر في األسنان األمامية: تجربة إكلينيكية عشوائية 12العنوان: 1 نيفين جوبان اوغلو , 1,2 عمر فائز عبد اللطيفالباحثون: المستخلص: ( بناًء على التحليل الطيفي ألربعة أنواع dcvلون في ترميمات قشرة الراتينج المركب المباشر ) الهدف: الهدف من هذه التجربة السريرية العشوائية هو تقييم تغيرات ال مريًضا من أجل األهلية للمشاركة ، تتراوح 28مختلفة من مركبات الراتينج بين خط األساس مباشرة بعد التلميع وبعد عام واحد من المتابعة . المواد والطرق: تم تقييم مريًضا 25سنان الفكية األمامية تم اعتبارهم للمشاركة في هذه الدراسة. في المجموع ، تم اختيار في األ dcvعاًما ، والذين أشاروا إلى ترميم 38و 18أعمارهم بين مرضى. تم تقسيم المشاركين عشوائيًا إلى أربع مجموعات 3في وقت وضع االستعادة( ، وتم استبعاد 20.9العمر: إناث ، متوسط 19ذكور و 6استوفوا معايير التضمين ) ، المجموعة بناًء على نوع / nanohybrid ips empress direct (ivoclar vivadent)] (ips) (13 1الراتينج المركب المستخدم للترميم 6ترميًما supra nano fill[estelite 3مرضى( ، المجموعة 7عملية ترميم / 14) (esباليابان([ ) gc)التعاون essentia] microfilled 2مرضى( ، المجموعة ∑ quick (tokuyama ( ])طوكيو ، اليابان ،eq) (17 / والمجموعة 7عملية ترميم )4مرضى nanofill [filtek ultimate (3m espe) ] (fu) من االستدعاء ، مرضى(. تم إجراء قياسات اللون األساسي باستخدام مقياس الطيف الضوئي مباشرة بعد االنتهاء والتلميع )خط األساس( ، وبعد عام واحد 5ترميم / 13) . لهذا الغرض ، تم تصنيع قالب سيليكون لكل مريض cielabوفقًا إلحداثيات ألوان dcvs( من قيم خط األساس وبعد عام واحد من متابعة δeتم حساب تغيير اللون ) dunn-bonferroniمع اختبار kruskal-wallisر واستخدامه كدليل لكل قياس لتوحيد موقع القراءات. تم تطبيق التحليل اإلحصائي للبيانات باستخدام اختبا posthoc بعد التحكم في توزيع البيانات من حيث الحالة الطبيعية مع اختبارshapiro wilk ترميًما(. 57مشاركًا ) 25. النتائج: في نهاية عام واحد ، تمت متابعة (. لم يكن p> 0.05ولكن لم يكن هناك فرق ذو داللة إحصائية بين جميع أنواع المركبات )المركب ، esأعلى من راتينج fuو eqو ipsلمركبات δeكان متوسط * بعد استرجاع لمدة عام واحد b* و δa(. كان هناك تغيير كبير في p> 0.05* بين أي نوع من أنواع الراتينج المركب ) lهناك فرق معتد به إحصائيًا في المتوسط (. الخالصة: بعد عام واحد من المتابعة ، قياسات مقياس الطيف الضوئي لترميمات القشرة المركبة من الراتنج المباشر ، تم p <0.05) dcvلجميع أنواع ترميمات أقل مقارنة δeقيمة ( متوسط microfilled hybrid) esالراتنج. أظهرت eqو fuو ipsو esلمركب δeالتوصل إلى عدم وجود فرق بين متوسط عات األخرى. أظهرت جميع مجموعات الراتينج المركب تغيرات في اللون ضمن المستويات المقبولة سريريًا بعد متابعة لمدة عام واحد. بالمجمو ameer.doc j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 48 assessment of the oral findings, salivary oxidative status and iga level among group of workers exposed to petroleum pollutants in al-daura oil refinery ameer s. hamza, b.d.s. (1) jamal n. ahmed, b.d.s., m.s., ph.d. (2) abstract background: oil refinery workers are continuously exposed to numerous hazardous materials. petroleum contains the heavy metals as a natural constituent or as additives. these metals induce the production of ros which associated with an oxidative damage to dna, proteins, and lipids. this study was conducted to assess the salivary levels of heavy metals, salivary oxidative status, oral immunological activity (salivary siga) and assessment of the oral findings among the workers of al-daura oil refinery in baghdad city. subjects, materials and methods: this study was done in al-daura oil refinery; samples consist of 60 workers involved in refinery processes (study group) and 20 non-workers (control group). oral examination and saliva collection was done to assess the oral findings and measurement the level of heavy metals (lead and cadmium), oxidative status (mda and sod) and secretary iga. results: salivary lead and cadmium was higher in study group (6.34 µg/dl and 0.56 µg/l) than that of control group (3.3 µg/dl and 0.34 µg/l) with highly significant difference (p<0.001). a significant increase (p<0.05) was found in salivary mda (15.3 ng/ml) and salivary siga (464.36 µg/ml) and significant decrease in salivary sod (1895.1 pg/ml) among the study group. lead has shown significant linear correlation with mda and iga. a significant reverse correlation was found between heavy metals (lead and cadmium) and sod. the oral examination revealed no oral lesions of interest. conclusion: workers in aldaura oil refinery exposed to pollution with heavy metals (pb and cd) which was associated with changes in the biochemical and immunological findings among the oral cavity. key words: petroleum, heavy metals, salivary oxidative stress, siga, oral findings. (j bagh coll dentistry 2015; 27(2):4853). introduction iraq is one of the significant countries in oil reservoir, production and exportation. crude oil fields and oil refineries are present on wide locations of the iraqi lands. these oil locations distributed from the north to the far south of the country. some of the fields are present close to or in the nearby cities, therefore its presence has an impact on the environment and health of the residents and workers inside the oil refineries. petroleum is perhaps the most substance demanded and consumed all over the world. the structure of petroleum is formed of an extremely complex mixture of hydrocarbon compounds, usually with minor amounts of nitrogen, oxygen and sulfur as well as trace amounts of metalcontaining compounds.(1) oil refinery is an industrial location where the crude oil is processed, decomposed and separated into many usable materials. one of the most important refineries constructed in iraq is aldaura oil refinery. this refinery was constructed in baghdad and begun to work in 1955. it is composed of many sections that produce different (1) master student. department of oral diagnosis. college of dentistry, university of baghdad. (2) assistant professor. department of oral diagnosis. college of dentistry, university of baghdad. products to cover the needs of iraq from fuel such as gasoline, kerosene, jet fuel and other products. most of these sections are old and many leaks have been noticed in the refinery. these leaks can be seen by soil saturation with oil and emission of different fumes to the air which can be felt at the moment of entry at the main gate. oil refinery workers are in continuous exposure to numerous hazardous materials. the work conditions place them at continuous risk of serious pollutants, injury and death. lead is toxic heavy metal the oil refinery workers are in a daily exposure.(2, 3) lead and cadmium emissions have increased dramatically during the 20th century. the petrol was the main source of lead exposure while the reason for cadmium increase was that cadmium-containing products are rarely re-cycled, but often dumped together with household waste. the adverse health effects of cadmium exposure may occur at low exposure levels, therefore, measures should be taken to reduce the lead and cadmium exposure in the general population in order to minimize the risk of adverse health effects.(4) many studies on the petroleum health effects were conducted. the oral health of occupationally exposed workers to petroleum was assessed by some investigators. dental caries and periodontal j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 49 diseases were increased in petrol filling workers. (5) this investigation was conducted to explore some scientific information and to add data for the more in depth researches about the impact of the petroleum and its derivatives on salivary constituents, up to our knowledge there are insufficient data relevant to this study, therefore the purpose of this investigation was considered to detect the salivary malondialdehyde and superoxide dismutase (as an indicator of oral oxidative status) in addition, lead and cadmium heavy metals were assessed as an important constituents of petroleum and its possible association with tissue damage or any oral findings. since leadand cadmium-induced tissue damages have been attributed, at least in part, to toxicant-induced oxidative stress.(6, 7) subjects, materials and methods after approvals were obtained from the scientific committee and local authorities, a total of eighty participants were enrolled in this study and they were divided into 2 groups: 1. study group: sixty non-smoker male workers in al-daura oil refinery were involved as a study group, with no signs, symptoms and history of any systemic disease. they were baghdad city residents. 2. control group: twenty non-smoker male subjects of baghdad city resident were involved in this study, with no signs and symptoms of any systemic disease. all the participated subjects have answered questionnaire form included information regarding their name, gender, age, smoking, residence, type of work and duration of employment. the oral examination for each individual was done using the disposable dental diagnostic tools and artificial light to detect the oral condition according to the sequence of who. (8) sample collection all saliva samples were collected at morning time between 9 a.m. and 1p.m. before collection of saliva, the subjects were instructed not to eat or drink (except water) for 1 hour. (9) mouth washing with pure water was carried out before sampling. all participants were instructed to collect saliva in their mouths for 5 minutes and to spit into a clean plastic container. saliva samples were kept in ice during the collection. in order to reduce bubble and foam, samples were centrifuged and stored at -23 cْ freezer for analysis. biochemical and immunological analysis; the salivary malondialdehyde, superoxide dismutase and immunoglobulin a were measured by the use of enzyme-linked immunosorbent assay kits. the heavy metals in saliva were analyzed at the poisoning consultation center\specialized surgeries hospital by using the atomic absorption spectrophotometer. salivary lead level was measured by the flame atomic absorption spectrophotometer. working pb standards (0,5,10,15 µg/dl) were prepared.. the standards, samples and quality control specimens were aspirated for measurement of lead. hallow cathode lamps were used for lead. absorption was measured at 283.2 nm wavelength. the measurement of salivary cadmium concentration was done by the flameless atomic absorption spectrophotometer. the samples were analyzed and atomic absorption was done with optical beam at 228.9 nm wavelength. results the mean of salivary lead and cadmium was higher in study group (6.34 µg/dl and 0.56 µg/l respectively) than that of control group (3.3µg/dl and 0.34 µg/l respectively) with highly significant difference (p<0.001). the mean of the salivary mda in study group (15.39 ng/ml) was higher than that of control group (7.96 ng/ml) with significant difference (p<0.05). unlike the mda, the mean of salivary sod of study group (1895.1 pg/ml) was lower than that of control group (2506.6 pg/ml) with significant difference (p< 0.05) a significant difference (p<0.05) was found between the mean of siga of the study group (464.36 µg/ml) and the mean of the control group (344.3 µg/ml), the siga in workers group was higher (p<0.05) compared with the control group. the increase in the level of salivary lead was correlated with an increase in the level of salivary mda, iga with significant correlation (p<0.05). the statistical analysis has shown a significant inverse correlation between the heavy metals (lead and cadmium) and sod (p<0.05). j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 50 table 1: the mean and sd of the parameters in study and control group sig. control patients parameters n sd mean n sd mean >0.05 20 8.28 43.7 60 10.95 43.93 age <0.001** 20 0.76 3.3 60 1.321 6.348 pb µg/dl <0.001** 20 0.11 0.34 60 0.103 0.56 cd µg/l <0.05* 20 10.9 7.96 60 16.54 15.39 mda ng/ml <0.05* 20 1034 2506.6 60 1392.7 1895.1 sod pg/ml <0.05* 20 122 344.3 60 186.7 464.36 siga µg/ml * p<0.05 significant, ** p<0.001 highly significant table 2: pearson's correlations (r) between the study parameters iga µg/ml mda ng/ml cadmium µg/l lead µg/dl age r p-value 263.0 lead µg/dl *0.042 0.333 0.262 cadmium µg/l 0.009* 0.043* 0.185 0.304 0.247 mda ng/ml 0.158 0.018* 0.057 0.310 0.263 0.377 0.236 iga µg/ml 0.09 0.052 0.003* 0.069 -0.055 -0.222 -0.294 -0.346 -0.17 sod pg/ml 0.676 0.088 *0.023 0.007* 0.194 * p <0.05 significant, ** p <0.001 highly significant 0 10 20 30 40 50 60 study group control group figure 1: difference in levels of the parameters between study and control groups. j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 51 figure 2: positive correlation between lead and mda figure 3: positive correlation between lead and siga. figure 4: inverse correlation between lead and sod. j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 52 figure 5: inverse correlation between cadmium and sod. discussion in this study the mean age of the study group and control was approximately equal to avoid the effect of age on the clinical, biochemical and immunological findings. in iraq the tetraethyl lead (tel) is used widely till now to increase the octane rating of gasoline (petrol), although this phase has been canceled and even the production of it was considered globally illegal. there is no strict regulation in management and maintenance of the constructions and pipelines. increase in lead and cadmium levels may be associated with presence of many leaks of these pipelines. poor education and concern about the effects of heavy metals on the health of the workers lead to absence of the protective measures which include the use of masks and gloves. in this study, the increase in mda and decrease in sod was agreed with study on occupationally exposed workers to petrol in petrol stations.(10) a significant positive relation was found between lead and the oxidative stress marker mda, this result was agreed with a studies on painters(11) and battery manufacturing workers.(12) the significant correlation between lead and mda (lipid peroxidation) can be explained by the lead-induced oxidative damage to membranes which is associated with changes in the fatty acid composition.(13) in addition, the fatty acid chain length and unsaturation are the determinant for membrane susceptibility to peroxidation, and lead induced arachidonic acid elongation which might be responsible for the enhanced lipid peroxidation of the membrane.(14) the reverse correlation between the heavy metals (lead and cadmium) and sod was agreed with study on rats exposed to combined effect of lead and cadmium,(15) however, it was disagreed with study on inhabitants of polluted area.(16) the decreased sod activity in workers group is probably due to interaction of lead with copper molecule. as sod is a zn-cu containing enzyme, hence lead exposure induced copper deficiency resulted in decreased sod activity.(17) it has been demonstrated that cadmium can replace zn to reduce sod activity.(18,19) given the complex composition of petroleum, the difference in oxidative status among al-daura oil refinery workers may be associated with other constituent of the petroleum. benzene is one of these components that can increase the oxidative damage.(20, 21) toluene, ethylbenzene and xylene can induce oxidative stress.(22) the correlation between the lead and iga in this study was agreed with a study on workers exposed to lead which found an increase in level of serum immunoglobulin a.(23) the increase in serum iga level may be due to the influence of lead on the differentiation of b cells into antibody producing cells, thereby amplifying b-cell expansion to secrete iga antibody.(24) in this study, the oral examination among workers revealed two cases of line and four cases of pigmentations in different sites in the oral cavity, some of these pigments may be physiological pigments which may need more investigations to determine if there is any association with systemic signs and symptoms of heavy metals toxicity. the oral lesions including ulcers, white and red lesions, infections and other mucosal problems were absent among workers and they didn`t have any history of pronounced oral lesions that can be associated with occupational exposure to pollutants. this absence of lesions in the presence of pollution may be due to increased level of mucosal immunity (↑siga) among workers since the level of secretory iga in saliva has an important role in the protection of the oral tissues against diseases.(25) j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 53 references 1. speight g. the chemistry and technology of petroleum. 3rd ed. new york/basel: marcel dekker; 1998. 2. engler r. oil refinery health and safety hazards: their causes and the struggle to end them. philadelphia, u.s.a: philadelphia area project on occupational safety and health, 1975. 3. gennaro v, ceppi m, boffeta p, fontana v, perrotta a. pleural mesothelioma and asbestos exposure among italian oil workers. scand j work environ health 1994; 20(3): 213–5. 4. jarup l. hazards of heavy metal contamination. british medical bulletin 2003; 68: 167–82. 5. ammar 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mytroie, aa. erythrocyte sod activity and other parameter of copper status in rats ingesting lead acetate. toxicol applied pharmacol 1986; 82: 512-20. 18. bauer r, demeter i, hasemann v, johansen jt. structural properties of the zinc site in cu,znsuperoxide dismutase; perturbed angular correlation of gamma ray spectroscopy on the cu, 111cd-superoxide dismutase derivative. biochem biophys res commun 1980; 94:1296– 1302. 19. kofod p, bauer r, danielsen e, larsen e, bjerrem mj. 113cd-nmr investigation of a cadmiumsubstituted copper, zinc-containing superoxide dismutase from yeast. eur j biochem 1991; 198: 60711. 20. uzma n, kumar bs, hazari ma. exposure to benzene induces oxidative stress, alters the immune response and expression of p53 in gasoline filling workers. american j industrial medicine 2010; 53(12):1264-70. 21. moro am, charão mf, brucker n, durgante j et al. genotoxicity and oxidative stress in gasoline station attendants. mutation research 2013; 14: 754(1-2): 6370. 22. kim jh, moon jy, park ey, lee kh, hong yc. changes in oxidative stress biomarker and gene expression levels in workers exposed to volatile organic compounds. industrial health 2011; 49(1): 814. 23. mishra kp, singh vk, rani r, yadav vs, chandran v, srivastava sp, seth pk. effect of lead exposure on the immune response of some occupationally exposed individuals. toxicology 2003; 188: 251-59. 24. mccabe mj jr, lawrence da. the heavy metal lead exhibits b cell stimulatory factor activity by enhancing b cell iga expression and differentiation. j immunol 1990; 145: 671-77. 25. martin sg, michael g. burkett's oral medicine diagnosis and treatment.10th ed. hamilton ontario: bc decker inc; 2003. الخالصة ھذه تحفز. كمادة مضافة َأو طبیعي كمكون الثقیلَة على المعادَن النفُط َیحتوي. الخطرِة المواِد إلى العدید من مستمر بشكل یتعّرضوَن النفط مصفاِة ُعّمال :مقدمة للمعادِن اللعابیِة المستویات لَتقییم أجرْت دراسِةال ھذه. والدھون البروتین، الحمض النووي، تأكسدي في بضرِر ترتبط التي الجذور الحرة إنتاَج المعادِن .مصفى الدورة النفطي ُعّماِل الحاالت المرضیة الفمویة لدى وتقییم) أ -الغلوبیولین المناعي نوع( الحالة المناعیة في اللعاب في اللعاب، الثقیلِة،الحالة التأكسدیة . شخصًا كمجموعة ظابطة 20یمثلون مجموعة الدراسة و عامًال 60 العینات شملت الدورة النفطي، مصفى في ُاجریت الدراسِة ھذه: والطرق المواد,المواضیع الحالة التأكسدیة ,)الرصاص والكادمیوم( الثقیلِة للمعادِن المستوى اللعابي قیاس ُاجري فحص الفم وجمع عینات اللعاب للتحري عن الحاالت المرضیة الفمویة و .أ-الغلوبیولین المناعي (والحالة المناعیة الفمویة ) راوكساید دسمیوتیزالمالوندایلدیھاید والسوب( أعلى إحصائیًا من المستوى ( µg/dl and 0.56 µg/l 6.34) )العمال(في مجموعة الدراسة ) الرصاص و الكادمیوم(المستوى اللعابي للمعادن الثقیلة :النتائج والغلوبیولین المناعي ) ng/ml 15.3( نتائج ھذه الدراسة أظھرت أیضًا زیادة إحصائیة في المالوندایلدیھاید (3.3µg/dl and 0.34 µg/l)الظابطة لدى المجموعة مع ) p<0.05(أظھر الرصاص عالقة طردیة. لدى مجموعة الدراسة) pg/ml 1895.1(و إنخفاض في السوبراوكسایددسمیوتییز ) µg/ml 464.3) (أ(نوع . و السوبراوكسایددسمیوتییز) الرصاص و الكادمیوم(بین المعادن الثقیلة ) p<0.05(وجدت عالقة عكسیة . )أ(غلوبیولین المناعي اإلفرازي نوع ال و المالوندایلدیھاید .لم یظھر الفحص الفموي أي حالة مرضیة ذات أھمیة وھذا التلوث مرتبط بتغیرات كیمیائیة حیاتیة , )اص و الكادمیومالرص(عمال مصفى الدورة النفطي یتعرضون إلى تلوث ناتج من المعادن الثقیلة :اإلستنتاج .ومناعیة على مستوى الفم type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 44 review article point of care testing: the future of periodontal disease diagnosis and monitoring mohamad khorshid1* 1mississauga smiles dentistry, 102-90 burnhamthorpe rd west, mississauga, ontario, canada. * correspondence: mohamad.khorshid@gmail.com abstract: manual probing and periodontal charting are the gold standard for periodontal diagnosis that have been used in practice over a century. these methods are affordable and reliable but they are associated with some drawbacks that cannot be avoided. among these issues is their reliance on operator’s skills, time-consuming and tedious procedure, lack sensitivity especially in cases of early bone loss, and causing discomfort to the patient. availability of a wide range of biomarkers in the oral biofluids, dental biofilm, and tissues that potentially reflect the periodontal health and disease accurately encouraged their use as predictive/diagnostic/monitoring tools. analysing biomarkers during care-giving to the patient using chairside kits is known as point of care (poc) testing. introduction of poc in periodontal practice could provide more flexibility and add further dimensions to the process of diagnosis and tailoring more precise treatment plan for the patients. this review aimed to highlight available poc testing used for periodontal diagnosis and disease prediction/monitoring. keywords: periodontal disease, periodontitis, saliva, gingival crevicular fluid, biomarkers, diagnosis, prognosis. introduction periodontitis is one of the most chronic prevalent disease, affecting over 45% of the populations worldwide (1). this disease is considered as a “silent killer” of the teeth and ranked in the second place among the main reasons for tooth loss (2). this disease has a huge economic impact and seriously associated with many systemic diseases such as diabetes mellitus, cardiovascular disease, and psychological disorders (3, 4). early detection and close monitoring are the most successful approaches to limit the negative outcomes of periodontitis. conventionally, diagnosis of periodontal disease depends on measuring periodontal parameters including bleeding on probing, clinical attachment level, and probing pocket depth together with radiographs. although these methods are reliable and cost-effective, they suffer from inherited drawbacks such as their dependence on the operator’s skills, probing force/direction, and dimensions of the probe (5, 6). in addition, 3d radiographic machines are sophisticated, expensive, and exposing the patients to unnecessary radiations (7). availability of a wide range of proteins i.e., biomarkers in the oral tissues, dental biofilm, and oral fluids including saliva, gingival crevicular fluid (gcf), oral rinse samples, and peri-implant sulcular fluid (pisf), encouraged their use as diagnostic/prognostic tools (8). advantages of biomarkers over conventional techniques is the ability to provide information about active disease sites, anticipate progression rate, determine the susceptibility of the individuals, and tailoring the treatment plan in more accurate way (8). these tests that performed during providing care to the patients are known as point of care (poc) testing. received date: 12-09-2022 accepted date: 15-10-2022 published date: 15-12-2022 copyright: © 2022 by the authors. the article is publication under the terms and conditions of the creative commons attribution (cc by) license. (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.2647 7/jbcd.v34i4.3277 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3214 https://doi.org/10.26477/jbcd.v34i3.3214 j. bagh. coll. dent. vol. 34, no. 4 2022 khorshi 45 several chairside tools were invited over the last decades to exploit a single or range of biomarkers in oral fluids to predict, diagnose, and monitor periodontal disease. the aim of this review was to summarize available poc testing commercially available that could be used in periodontal diagnosis and monitoring. biological sources for biomarkers oral cavity exhibits different biologic sources readily available for analysis such as saliva, gcf, plaque biofilm, tissues, and pisf. saliva is the most popular biofluid used for clinical and experimental purposes due to its abundance, easily and non-invasively collected, enriched with biomarkers that reflect many local/systemic states, and can be collected without ethical issues (9). use of saliva as a source of biomarkers is rapidly expanding particularly after recent transcriptomic and proteomic studies that added considerable number of biomarkers that support the use of saliva as an alternative to blood and urine samples (10, 11). however, the main problem with saliva is the reflection of the whole mouth condition without the ability to pinpoint sites with active disease process. in addition, the biomarkers are highly diluted in saliva which render their detection process difficult. alternatively, gcf and pisf are good source of biomarkers that specifically reflecting the condition of the site which is more useful tools to assess the efficacy of periodontal therapy (12). nevertheless, collection procedure is technically demanding and the strips are highly prone to contamination. additionally, only small volume could be retrieved that add further complications to assaying procedure (12). subgingival biofilm samples considered as the main source for studying putative periodontal pathogens which, like gcf sampling, is subjected to contamination and technical issues to isolate and culture certain fastidious microorganisms (13). the poc assays are based on microbiological, biochemical, and genetic test performed on different biological samples available (figure 1) figure 1: biological source of biomarkers in the oral cavity and the corresponding assays used for point of care testing. commercial point of care testing in periodontics integrated microfluidic platform for oral diagnostics (impod) this microfluidic diagnostic platform was designed to detect salivary biomarkers (mmp-8, il-6, tnf-α) indicative of periodontal disease using electrophoretic immunoassays approach (14). this portable device j. bagh. coll. dent. vol. 34, no. 4 2022 khorshi 46 allows analysis of multiple analytes using small volumes of saliva (10 μl) with a relatively short time (less than 250 sec) and low cost (14). myperiopath® this dna polymerase chain reaction-based test is mainly used to detect periodontal pathogens, in salivary samples, responsible for initiation and progression of periodontal disease and could be associated with other systemic diseases such as diabetes and adverse pregnancy outcomes. these pathogens are divided according to their risk into high (aggregatibacter actinomycetemcomitans, porphyromonas gingivalis, tannerella forsythia, and treponema denticola), moderate (eubacterium nodatum, fusobacterium nucleatum/periodonticum, prevotella intermedia, campylobacter rectus, and peptostreptococcus), and low (eikenella corrodens, and capnocytophaga species) (15, 16). omnigene® it is a dna probe system used for quantitative profile analysis for eight periodontal bacteria (p. gingivalis, p. intermedia, a. actinomycetemcomitans, f. nucleatum, e. corrodens, c. rectus, t. forsythia, and t. denticola). the targeted samples are collected from subgingival plaque biofilm (17). periogard death of the cells is highly associated with the release of the cytoplasmic enzyme aspartate aminotransferase (ast) as a by-product. this principle was used in the development of periogard to detect active site exhibiting remarkable periodontal tissue destruction (18-20). a multicenter trial aimed to validate periogard kit by measuring ast levels in gcf sample collected from patients treated by scaling and root planing. the results of showed consistency reported by this chairside tool over different locations (20). the gcf sample containing this enzyme is used for analysis; however, this assay is considered technically demanding which limits its use in clinical practice (15). periocheck® this chairside device obtained food and drug administration (fda) approval in the united states. the principle of this technique relies on the presence of natural protease activity within gcf. briefly, strips containing gcf samples are placed on a gel containing insoluble dye-labelled collagen fibrils which would be digested by the proteases in the gcf. the reaction outcome appears as a blue color (15). results of a clinical trial aimed to evaluate diagnostic and prognostic potentials of this device indicated that periocheck® lacks diagnostic and predictive reliability as compared to clinical methods (21). in addition, the gcf samples from interproximal surface are prone to salivary contamination which further reduces the efficacy of this test. mmp dipstick irreversible periodontal tissue destruction is associated with upregulation of active-matrix metalloproteinases (mmp)-8 in the gcf of natural dentition and peri-implant sulcular fluid with increasing neutrophil activity. this fact was used to develop a chair-side dipstick test containing monoclonal antibodies j. bagh. coll. dent. vol. 34, no. 4 2022 khorshi 47 to mmp-8 (22). this tool exhibited high accuracy in differentiating periodontal health from disease, predicting and monitoring periodontal/peri-implant disease (8). perioscan (bana) the basic of this test depends on the presence of trypsin-like proteases secreted by red complex putative pathogens p. gingivalis, t. denticola, t. forsythia in subgingival biofilm samples which hydrolyzing the trypsin substrate (23). although results from clinical studies encouraged the use of bana to monitor the outcome of periodontal therapy (24), another study showed opposite results (21). evalusitetm periodontal test subgingival biofilm plaque samples are used for analysis to detect three periodontal pathogens (a. actinomycetemcomitans, p. gingivalis and p. intermedia). this assay is based on sandwich-elisa in which the presence of these bacteria is indicated by pink spots (15). this assay is prone to subjectivity and its limitation to detect narrow range of putative pathogens are the main drawbacks (25). however, it is highly sensitive for detecting the aforementioned bacteria, rapid, and user-friendly (26, 27). toxicity prescreening assay (topas) this assay can indirectly detect the presence of putative pathogens via their toxins and proteins. indeed, actively dividing bacteria and increasing mass of the biofilm are associated with increased metabolic activity/product in the gcf that can discriminate between active and inactive periodontal destruction sites (28). periodontitis susceptibility trait test this test is one of few commercially available genetic-based assays which identifies the genetic predisposition of individuals to severe periodontitis by detecting polymorphisms of il‑1α at +4845 and 1β +3954 loci. however, ambiguity is associated with the predictive potential of this assay and the results must be interpreted with caution (29). myperioid another il-1-based genetic assay which predicts the susceptibility of patients at higher risk to develop periodontal disease via taking salivary samples that shipped and analysed in the laboratory (15). conclusions chairside diagnostic kits available in the market showed encouraging outcomes with decent sensitivity and specificity to predict, diagnose, and monitor periodontal disease on a community level. these tools could reduce treatment time, accurately diagnosing the disease; hence, help in tailoring personalized treatment plan with more predictable outcomes. however, each assay suffers certain drawback(s) that should be solved before recommended for use as a routine dental practice by general practitioners. conflict of interest: none. j. bagh. coll. dent. vol. 34, no. 4 2022 khorshi 48 references 1. nazir m, al-ansari a, al-khalifa k, alhareky m, gaffar b and almas k. global prevalence of periodontal disease and lack of its surveillance. scientificworldjournal. 2020;2020:2146160. 2. tonetti ms, jepsen s, jin l and otomo-corgel j. impact of the global burden of periodontal diseases on health, nutrition and wellbeing of mankind: a call for global action. j clin periodontol. 2017;44:456-62. 3. reynolds i and duane b. periodontal disease has an impact on patients' quality of life. evid based dent. 2018;19:14-5. 4. winning l and linden gj. periodontitis and systemic disease. bdj team. 2015;2:15163. 5. gupta n, rath sk and lohra p. comparative evaluation of accuracy of periodontal probing depth and attachment levels using a florida probe versus traditional probes. med j armed forces india. 2015;71:352-8. 6. shapoff ca. understanding the limitations of dental radiographs--implications for soft-tissue management programs. compend contin educ dent. 2004;25:338-40, 42, 44 passim. 7. kamburoğlu k. use of dentomaxillofacial cone beam computed tomography in dentistry. world j radiol. 2015;7:128-30. 8. gul ss, abdulkareem aa, sha am and rawlinson a. diagnostic accuracy of oral fluids biomarker profile to determine the current and future status of periodontal and peri-implant diseases. diagnostics (basel). 2020;10. 9. malamud d. saliva as a diagnostic fluid. dent clin north am. 2011;55:159-78. 10. genco rj. salivary diagnostic tests. the journal of the american dental association. 2012;143:3s-5s. 11. haririan h, andrukhov o, bertl k, lettner s, kierstein s, moritz a and rausch-fan x. microbial analysis of subgingival plaque samples compared to that of whole saliva in patients with periodontitis. j periodontol. 2014;85:819-28. 12. barros sp, williams r, offenbacher s and morelli t. gingival crevicular fluid as a source of biomarkers for periodontitis. periodontol 2000. 2016;70:53-64. 13. nickles k, scharf s, röllke l, dannewitz b and eickholz p. comparison of two different sampling methods for subgingival plaque: subgingival paper points or mouthrinse sample? j periodontol. 2017;88:399-406. 14. herr ae, hatch av, giannobile wv, throckmorton dj, tran hm, brennan js and singh ak. integrated microfluidic platform for oral diagnostics. ann n y acad sci. 2007;1098:362-74. 15. srivastava n, nayak pa and rana s. point of carea novel approach to periodontal diagnosis-a review. j clin diagn res. 2017;11:ze01-ze6. 16. javaid ma, ahmed as, durand r and tran sd. saliva as a diagnostic tool for oral and systemic diseases. j oral biol craniofac res. 2016;6:66-75. 17. van arsdell sw, difronzo f, backman kc and mahler ph. selling biotechnology in the dental medicine marketplace: the omnigene diagnostics dna probe tests for periodontal pathogens. technol health care. 1996;4:339-46. j. bagh. coll. dent. vol. 34, no. 4 2022 khorshi 49 18. persson gr, derouen ta and page rc. relationship between gingival crevicular fluid levels of aspartate aminotransferase and active tissue destruction in treated chronic periodontitis patients. j periodontal res. 1990;25:81-7. 19. chambers da, imrey pb, cohen rl, crawford jm, alves me and mcswiggin ta. a longitudinal study of aspartate aminotransferase in human gingival crevicular fluid. j periodontal res. 1991;26:65-74. 20. persson gr, alves me, chambers da, clark wb, cohen r, crawford jm, derouen ta, magnusson i, schindler t and page rc. a multicenter clinical trial of periogard in distinguishing between diseased and healthy periodontal sites. (i). study design, methodology and therapeutic outcome. j clin periodontol. 1995;22:794-803. 21. hemmings kw, griffiths gs and bulman js. detection of neutral protease (periocheck) and bana hydrolase (perioscan) compared with traditional clinical methods of diagnosis and monitoring of chronic inflammatory periodontal disease. j clin periodontol. 1997;24:110-4. 22. sorsa t, mäntylä p, rönkä h, kallio p, kallis gb, lundqvist c, kinane df, salo t, golub lm, teronen o and tikanoja s. scientific basis of a matrix metalloproteinase-8 specific chair-side test for monitoring periodontal and peri-implant health and disease. ann n y acad sci. 1999;878:130-40. 23. loesche wj, syed sa and stoll j. trypsin-like activity in subgingival plaque. a diagnostic marker for spirochetes and periodontal disease? j periodontol. 1987;58:266-73. 24. dhalla n, patil s, chaubey kk and narula is. the detection of bana micro-organisms in adult periodontitis before and after scaling and root planing by bana-enzymatic™ test kit: an in vivo study. j indian soc periodontol. 2015;19:401-5. 25. mikx fh and renggli hh. [how sensible are bacteriological tests in periodontology?]. ned tijdschr tandheelkd. 1994;101:484-8. 26. boyer bp, ryerson cc, reynolds hs, zambon jj, genco rj and snyder b. colonization by actinobacillus actinomycetemcomitans, porphyromonas gingivalis and prevotella intermedia in adult periodontitis patients as detected by the antibody-based evalusite test. j clin periodontol. 1996;23:477-84. 27. nakagawa t, saito a, takahashi j, komiya a, hosaka y, yamada s and okuda k. evaluation of evalusitetm periodontal test for detecting periodontopathic bacteria. nihon shishubyo gakkai kaishi (journal of the japanese society of periodontology). 1995;37:312-6. 28. pucau cg, dumitriu a and dumitriu ht. biochemical and enzymatic diagnosis aids in periodontal disease. ohdmbsc. 2005;4:19-25. 29. greenstein g and hart tc. a critical assessment of interleukin-1 (il-1) genotyping when used in a genetic susceptibility test for severe chronic periodontitis. j periodontol. 2002;73:231-47. ومراقبتها اللثة أمراض تشخيص مستقبل: الرعاية نقطة اختبار محمد خورشيد : الباحثون : المستخلص التكلفة ميسورة الطرق هذه. الزمان من قرن مدى على العملية الممارسة في استخدامها تم التي األسنان دواعم امراض لتشخيص الذهبي المعيار اليدوي الفحص يعتبر وممال طويالً وقتًا تستغرق التي واإلجراءات ، الطبيب مهارات على اعتمادهم المشكالت هذه بين من. تجنبها يمكن ال التي العيوب ببعض مرتبطة ولكنها وموثوقة الحيوية المؤشرات من واسعة مجموعة توافر إن. المريض إزعاج في والتسبب المبكر، العظام فقدان حاالت في خاصة الحساسية ونقص ، بالنسبة للمراجع والمعالج j. bagh. coll. dent. vol. 34, no. 4 2022 khorshi 50 . مراقبة/ تشخيصية/ تنبؤية كأدوات استخدامها شجع ومرضها اللثة صحة تعكس أن المحتمل من التي واألنسجة لألسنان الحيوية واألغشية الفم في الحيوية السوائل في المرونة من مزيدًا اللثة ممارسة في poc إدخال يوفر أن يمكن(. poc) الرعاية نقطة اختبار باسم للمريض الرعاية تقديم أثناء الحيوية المؤشرات تحليل يُعرف في المستخدم المتاح poc اختبار على الضوء تسليط إلى هذه المراجعة البحثية تهدف . للمرضى دقة أكثر عالج خطة وتصميم التشخيص لعملية أخرى أبعاد وإضافة . ومراقبتها امراضهاب والتنبؤ اللثة تشخيص type of the paper (article journal of baghdad college of dentistry, vol. 34, no.3 (2022), issn (p): 1817-1869, issn (e): 2311-5270 17 research article the effect of sweet and salty taste sensitivity on gingival health in relation to salivary serotonin among type1 diabetic patients aged 12-14 years tabarak adil rasool 1*, ban sahib diab 2 1 master student, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. 2professor, department of pediatric and preventive dentistry, college of dentistry, university of baghdad, iraq. *correspondence: tabarkadil@yahoo.com abstract: background: this study was conducted among diabetic persons to assess the sweet and salty taste sensitivity with its effect on gingival health in relation to salivary serotonin levels. materials and methods: a cross-sectional comparative study design was used. all patients with diabetes aged 12-14 years that attend the paediatric hospital at baghdad medical city with specific inclusion criteria were involved in the sample of the present study (patients group 50 patients) compared with non-diabetic persons matched in age and gender of the study sample (control group 70 patients) who were attending dental unit in the college of dentistry/university of baghdad. a two-alternative forced choice question including each component presented at five different quantities was used to evaluate the threshold sensitivity of salt and sweet taste, sub-sample of 44 subjects was recruited from each group and matched in age and gender for salivary analysis and serotonin measurement and gingival health status was measured by using the gingival index. results: data analysis of this study revealed that the occurrence of the highest sweet threshold was found among diabetic persons with no significant difference. the data revealed no significant difference in the mean gingival index while salivary serotonin value was lower in diabetic subjects with a significant difference; meanwhile, it showed no significant relation with both taste thresholds. conclusions: within the limitation of this study, it was observed, that diabetes did not affect salty and sweet taste thresholds in addition to gingival health. whereas salivary serotonin had a role among the diabetic patients by which it was lower among diabetic subjects. keywords: taste thresholds, serotonin, diabetes introduction diabetes mellitus is a category of metabolic disorders characterized by hyperglycemia in the absence of treatment caused by defects in insulin secretion, insulin action, or both (1). the destruction of the ß-cells in the pancreas causes type 1 diabetes mellitus (t1dm). when the pancreas stops producing insulin i.e. autoimmune impact, the result will be absolute insulin deficiency (2). taste impairment can be induced by a systemic metabolic abnormality that affects the taste senses, such as diabetes (3). it has been linked to taste disorders such as ageusia, hypogeusia, and dysgeusia (4). sweetness refers to the sweet taste associated with various sugars and sweeteners. it plays a function in human nutrition by guiding feeding behavior toward meals that provide both energy and important nutrients (5). diabetic individuals have shown to have impairment for the sweet taste thresholds when compared to other taste modalities (6). many species appear to like the taste of salt. even when there is no physiological necessity for salt, received date: 2-1-2022 accepted date: 10-2-2022 published date: 15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license. (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbcd .v34i3.3213 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/%2010.26477/jbcd.v34i3.3213 https://doi.org/%2010.26477/jbcd.v34i3.3213 j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 18 humans like foods that contain it (7). a person's capacity to perceive and discriminate between salty and bitter solutions can be reduced by diabetes and age (8). because various individual characteristics can play a role in the development of diabetes, many studies had theorized a relationship between diabetes and taste sensitivity (9,10). previously jorgensen and buch(11) found that there was no difference in taste detection between diabetics and non-diabetic persons. in addition, dye and koziatek(12) reported that diabetic patients did not differ significantly in the threshold for sweet from non-diabetic subjects, while later on khera and saigal(13) found that patients with diabetes demonstrate a high threshold for sweet, salt and sour taste. also, wasalathanthri et al(10) found a significant increase in the detected threshold of sucrose was observed among diabetics compared to non-diabetic persons. concerning salt taste, schelling et al(14) reported that an altered threshold for sweet taste was found only and not for salt. while khobragade et al(6) found a significant increase in taste threshold for salt, sweet, sour and bitter among type 1 diabetics. serotonin is a neurotransmitter in the brain that can also be discovered outside the central nervous system, such as in the pancreas (15). it is thought to be a key regulator of both ß-cell proliferation and insulin secretion. (16). taste problems are linked to changed serotonin levels, such as during anxiety or depression, showing the role of these transmitters in the detection of taste thresholds in health and sickness (17). gingivitis is a site-specific inflammatory disorder caused by the formation of dental biofilm (18). many of the conditions related to taste abnormalities include inflammation as a common cause. taste abnormalities are common in patients with infectious disorders, such as oral cavity infections, (19). the current study hypothesized that sweet and salt taste sensitivity has no effect on salivary serotonin levels in relation to gingival health. the goal of this study was to investigate sweet and salt taste sensitivity among diabetics, as well as its impact on gingival health in relation to salivary serotonin levels. materials and methods the present study was a cross-sectional comparative study approved by the scientific committee in the college of dentistry/university of baghdad (number: 319). before data collection, official permissions were achieved from the relevant authority; a specific consent form was produced and given to the parents to acquire permission for their children to participate in the study and their full cooperation. the study sample includes all the diagnosed cases of type 1 diabetic patients aged (12-14) years old with glycated haemoglobin ≥ 7 and without any other systemic diseases who attended the paediatric teaching hospital compared with a control group that include healthy persons , attending dental unit in the college of dentistry/university of baghdad without any systemic disease. the sample of this study consisted of 50 diabetic subjects and 70 non-diabetic subjects, a sub-sample of 44 subjects was recruited from each group that matched in age and gender for salivary analysis and serotonin measurement. a special case sheet was used for writing all the information and data that including: age, gender, gingival index and taste measurements. an unstimulated saliva sample was collected in the morning for assessing salivary serotonin by spitting method (20). the concentration of salivary serotonin was detected by an enzyme-linked immune-sorbent assay (elisa) using a serotonin elisa-kit(21). a two-alternative forced choice question was used to determine taste threshold sensitivity (22). the test included ten solutions, five sodium chloride solutions (0.09, 0.18,0.37,0.75, 1.5 g/l) and five sucrose solutions (0.5, 1, 2, 4, 8 g/l). each solution was given to the participants in a disposable plastic cup. subjects were instructed to evaluate the taste of each solution before expectorating. when the subject made the correct answer, the same concentration was given again. when the subject made a wrong answer, the next trial was held at the next j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 19 highest level. after two accurate answers in a row, the test ended (23). gingival inflammation was evaluated using the gingival index (gi) by loe and sillness (24). statistical analysis used includes: descriptive statistics for quantitative data are mean, standard error while frequency and percentage for qualitative ones. inferential statistics were student t-test, fisher exact, spearman correlation and probability of error (p-value). results the sample of the present study included 50 diabetic patients and 70 non-diabetic patients in the age range of 12-14 years old. the distribution of the sample according to age and gender was presented in table 1. it was clear that the occurrence of diabetes was highest for patients aged 12 years old and decreased with age. concerning gender distribution at the same table, it was found that diabetes occurred more among females than males. however, the statistical analyses showed no significant association between age, gender and diabetic status. table (1): distribution of the sample according to age and gender variables groups p value diabetic group non-diabetic group n. % n. % age (years) 12 22 44.00 30 42.86 0.869 ns 13 16 32.00 20 28.57 14 12 24.00 20 28.57 gender male 16 32.00 33 47.14 0.096 ns female 34 68.00 37 52.86 ns not significant (chi-square test was used) the distribution of the sample according to sweet taste threshold concentrations was shown in table 2. this table showed that 40% of diabetic children detected the sweet taste at a concentration of 8 gm/l, while only 37% of the non-diabetic group detect the same concentration. however, 54% of the diabetic and 45.71% of the non-diabetic group could not detect the highest concentration. however, the statistical analyses showed no significant association between diabetic status and sweet taste threshold detection. table (2): distribution of the sample according to sweet taste threshold sweet taste threshold conc.gm/l groups fisher exact diabetic group non-diabetic group n. % n. % group1(1gm) 1 2.00 2 2.86 0.460 ns group 2(2gm) 0 0.00 3 4.29 group 3(4gm) 2 4.00 7 10.00 group 4(8gm) 20 40.00 26 37.14 group5(> 8 gm/l) 27 54.00 32 45.71 ns not significant the distribution of the sample according to salt taste threshold concentrations was shown in table 3. this table showed that diabetics people who detected salt at a concentration of 0.75gm/l constitute only 16% which was higher than the non-diabetic group which constitutes 12.86%. however, the oppo j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 20 site result was found with increasing the concentration as the non-diabetic persons who detected the 1.5gm/l were higher (45.71%) than the diabetic persons (32.0%). on the other hand, the diabetic persons who could not detect the salt taste at the highest concentration formed a higher percentage (50.0%) than the non-diabetic group (41.43%), however, the statistical analyses showed that there was no significant association between the diabetic condition and the salt taste. table (3): distribution of the sample with different salt taste thresholds among diabetic and non-diabetic groups salt taste threshold conc. g/l groups fisher exact diabetic group non-diabetic group n. % n. % group1 (0.37gm) 1 2.00 0 0.00 0.309 ns group2 (0.75gm) 8 16.00 9 12.86 group 3(1.5gm) 16 32.00 32 45.71 group4 (> 1.5 g/l) 25 50.00 29 41.43 ns not significant the concentration of serotonin in saliva that compared the diabetic and the non-diabetic groups were shown in table 4. this table showed that the mean value of salivary serotonin was higher among the non-diabetic group than in the diabetic group. table (4): the concentration of salivary serotonin in saliva (ng/ml) in both diabetic and non-diabetic groups groups salivary serotonin (ng/ml) n mean ±se t-test df p value effect size diabetic group 44 16.39 2.21 1.96 86 0.05 0.5 medium non-diabetic group 44 23.37 2.78 table 5 shows the correlation between salivary serotonin with sweet and salt taste thresholds among diabetic and non-diabetic groups. the data showed that the correlation between taste thresholds and serotonin value in both groups was in a positive direction. however, statistical analyses showed that there was no statistically significant difference (p>0.05.) table (5): the correlation between salivary serotonin and sweet and salt taste thresholds among diabetic and non-diabetic groups groups salivary serotonin (ng/ml) salt sweet diabetic group rsp 0.094 0.212 p-value 0.542 0.168 non-diabetic group rsp 0.175 -0.065 p-value 0.257 0.673 *rsp: spearman correlation used j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 21 table 6 illustrated the mean value of the gingival index among the diabetic and the non-diabetic groups. data analysis showed that the mean value of the gingival index was higher among the diabetic group. however, the results showed that the difference was not significant. table (6): mean value of gingival index among diabetic and non-diabetic groups. groups diabetic group non-diabetic group n mean ±se n mean ±se t-test df p value gingival index 50 1.034 0.017 70 1.013 0.019 0.763 118 0.447 ns ns not significant (student t-test used) table 7 illustrated the correlation coefficient between sweet and salt taste thresholds with gingival index among diabetic and non-diabetic groups. the table showed that the correlations between taste thresholds and gingival index in both groups were in a positive direction. however, the relations were not statistically significant (p>0.05.) table (7): the correlation coefficient between sweet and salt taste thresholds with gingival index among diabetic and non-diabetic groups groups gingival index salt taste sweet taste rsp p-value rsp p-value diabetic group 0.065 0.653 0.100 0.489 non-diabetic group 0.114 0.347 -0.142 0.240 ns not significant * rsp: spearman correlation used discussion taste has been demonstrated to be an essential tool in the regulation of nutrient ingestion, digestive process monitoring, and the release of hunger and satiety neuroendocrine hormones. few studies had examined how taste sensitivity changes in normal and pathological situations, and how this affects oral health (25). the perception of sweet and salt tastes in t1dm patients was assessed in this study, which took into account gender, age and the concentration of the taste. age and gender were not considered confounding variables as there was no significant difference between groups. the present study was conducted and mainly aimed at comparing the taste detection thresholds among t1dm and controls and to detect whether taste impairment occurred among type 1 diabetes. the result of the current study found that the distribution according to sweet taste thresholds revealed that the groups who detected the higher sucrose concentrations formed the higher percentage in both diabetic and control groups and yet there was no significant difference in the detection thresholds, this agreed with previous studies conducted by jorgensen and buch(11), dye and koziatek(12), while disagreed with studies by khera and saigal(13) ,wasalathanthri et al(10), some of them may detect it as a bitter taste, which might be due to the receptors for the sweet taste, located in the type ii cells of the taste buds that are the sweet and bitter sensing and transducing cells(26). j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 22 another result concerning the frequency distribution of salt taste threshold revealed that groups that detect higher salt concentrations formed the higher percentage in both groups, and there was no significant difference in detection thresholds between groups, which goes in accordance with the previous study by schelling et al(14). these results concerning sweet and salt taste are not supported by khobragade et al (6) study. serotonin was successfully detected in the saliva, although the mean value of salivary serotonin was higher in the non-diabetic group than diabetic group, this could be explained neuro-pathologically, that depletion of brain monoaminergic activity, especially the serotonin system, due to a persistent chronic diabetic condition can cause mood and behavioral problems, and that persistent hyperglycemia can cause neurotransmitter activity to be lowered (27). also, it may be explained that, because pancreatic b-cells produce serotonin (28) and because type 1diabetes patients had destructed b-cells, so there is decrease in serotonin levels in the diabetic group. another result found that the correlation of serotonin with taste thresholds in both groups was in a positive direction. at the level of the taste bud, the strongest evidence for serotonin's participation in taste signaling exists. serotonin is used as a neurotransmitter in the taste bud to modulate cellular responses to taste stimuli even before it is sent to the main afferent gustatory neurons. (29) . however, statistical analysis showed that it was not significant statistically and this disagrees with heath et al (17) study that showed serotonin and noradrenaline had a role in determining the taste thresholds, and the human taste was plastic in healthy people. alteration of these neurotransmitters affects various taste modalities in different ways. in contrast to larson et al (30) study, which found that taste buds activation triggers serotonin release, serotonin is released directly by type iii taste cells in reaction to acidic (sour) stimuli and indirectly in response to sweet and bitter taste stimulation. concerning gingival health status, the results showed that the mean value of the gingival index was higher among the diabetic group. it may be that the diabetes oral complications can affect the primary periodontium as early as age 6 years old, possibly earlier. these findings highlighted the importance of emphasizing good oral hygiene to prevent future periodontal complications among diabetic patients(31), even though the difference was not significant, which could be due to the limited sample size, these results were in accordance with a study by ismail et al(32) and with previous iraqi study by sarmamy et al (33) that found when diabetes children compared to healthy persons, no statistically significant difference in the gingival index was found between the two groups. researchers in dentistry had suggested that oral diseases should be included among the complications of diabetes (34,35). the current result revealed that the correlations between taste thresholds and gingival index in both groups were in a positive direction; this could be explained as that gingivitis is a site-specific inflammatory condition. inflammation is triggered when toll-like receptors are activated by inflammatory stimuli derived from pathogens or damaged tissues, or stress (36) toll-like receptors, type i and ii interferon receptors are located in taste tissue (37). the immune response to viral and bacterial pathogens is mediated by cytokines. interferons are one of the main categories of cytokines critical in fighting these invaders (38). the strong association between inflammation and taste impairment suggested that inflammation might affect the pathogenesis of taste dysfunction (37). however, the difference was not j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 23 statically significant, this agreed with ohnuki et al, which found that taste hyposensitivity had little association with oral health status, such as dental plaque and gingival status (39). conclusion diabetes mellitus is a devastating chronic condition that is becoming a global epidemic. the findings of the present study showed that diabetes and oral health were related, with no effect on taste detection thresholds and the effect of serotonin level was less in the diabetic group. hence, there was a need for appropriate health education as good oral health is important for diabetic individuals. conflict of interest: none. references 1. world health organization (2019). classification of diabetes mellitus. geneva: licence: cc by-nc-sa 3.0 igo. 2. eiken and o. snorgaard. endokrinologi i klinisk praksis. munksgaard, 2016. 3. m. bromley and r. l. doty. clinical disorders affecting taste: an update. john wiley & sons,inc., 3 edition, 2015. 4. bhandare, n.n., keny, m.s, nevrekar, r.p.,and bhandare p.n.(2014). diabetic tongue could it be a diagnostic criterion?,journal of family medicine and primary care, 3(3): 290–291. 5. drewnowski, a., mennella, j.a., johnson, s.l. and bellisle,f. (2012).sweetness and food preference. journal of nutrition; 142(6):1142s-1148s. 6. khobragade, r.s., wakode, s.l. and kale a.h(2012). physiological taste threshold in type 1 diabetes mellitus. indian journal of physiology and pharmacology, 56(1) : 42–47 7. gary k. beauchamp and leslie j stein (2010). salt taste …. 8. hardy, s.l., brennand, c.p. and wyse, b.w. (1981). tas te thresholds of individuals with diabetes mellitus and of control subjects. j am diet assoc ; 79(3): 286–289. 9. khan t. (2018). oral manifestations and complications of diabetes mellitus: a review. int j med health res; 4:50–52. 10. wasalathanthri, p. hettiarachchi, and s. prathapan. sweet taste sensitivity in pre-diabetics, diabetics and normoglycemic controls: a comparative cross sectional study. bmc endocrine disorders, 14:67, 2014. 11. jorgensen mb, buch nh. studies on the sense of smell and taste in diabetics. acta otolaryngol 1961; 53: 539–545. 12. dye cj, koziatek d. age and diabetes effects on threshold and hedonic perception of sucrose solution. j gerontol 1981; 36(3): 310– 315. 13. khera, s., & saigal, a. (2018). assessment and evaluation of gustatory functions in patients with diabetes mellitus type ii: a study. indian journal of endocrinology and metabolism, 22(2), 204–207. 14. schelling jh, tetreault l, lasangana l, davis m. abnormal taste threshold in diabetes. lancet 1965; 1: 508–512. 15. richard robinson,2009. serotonin's role in the pancreas revealed at last. plos biol. 2009 oct; 7(10): e1000227. 16. berger m, scheel dw, macias h, miyatsuka t, kim h, hoang p, ku gm, honig g, liou a, tang y, regard jb, sharifnia p, yu l, wang j, coughlin sr, conklin br, deneris es, tecott lh, german ms. galphai/o-coupled receptor signaling restricts pancreatic beta-cell expansion. proc natl acad sci u s a. 2015; 112:2888–2893. 17. heath tp, melichar jk, nutt dj, donaldson lf.(2006).human taste thresholds are modulated by serotonin and noradrenaline, , j neurosci. ;26(49):12664-71 j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 24 18. 29-trombelli l, tatakis dn, scapoli c, bottega s, orlandini e, tosi m. modulation of clinical expression of plaque-induced gingivitis. ii. identification of “high-responder” and “low-responder” subjects. j clin periodontol. 2004; 31: 239–252. 19. cullen mm, leopold da. disorders of smell and taste. med. clin. north am. 1999;83:57–74 20. khurshid, z., zohaib, s., najeeb, s., zafar, m. s., slowey, p. d., & almas, k. (2016). human saliva collection devices for proteomics: an update. international journal of molecular sciences, 17(6), 846. 21. matsunaga, m., ishii, k., ohtsubo, y., noguchi, y., ochi, m., & yamasue, h. (2017). association between salivary serotonin and the social sharing of happiness. plos one, 12(7), e0180391. 22. arbisi, p.a., billington, c.j., levine, a.s. (1999). the effect of naltotrexone on taste detection and recognition threshold. appetite, 32: 241-249. 23. mojet, j., christ-hazelhof, e., heidema, j. (2005). taste perception with age: pleasantness and its relationships with threshold sensitivity and supra-threshold intensity of five taste qualities. food qual. prefer., 16: 413-423. 24. loe, h. and silness, j. 1963. periodontal disease in pregnancy i. acta odonto scand; 21,533-551. 25. jeon, s.; kim, y.; min, s.; song, m.; son, s.; lee, s. taste sensitivity of elderly people is associated with quality of life and inadequate dietary intake. nutrients 2021, 13, 1693. 26. roper s.d. 2006.cell communication in taste buds. cell mol life sci.;63:1494–1500. 27. prabhakar, v., gupta, d., kanade, p., & radhakrishnan, m. (2015). diabetes-associated depression: the serotonergic system as a novel multifunctional target. indian journal of pharmacology, 47(1), 4–10. 28. almaça j, molina j, menegaz d, pronin an, tamayo a, slepak v, berggren po, caicedo a. human beta cells produce and release serotonin to inhibit glucagon secretion from alpha cells. cell rep. 2016 dec 20;17(12):3281-3291. 29. herness s, zhao fl, kaya n, shen t, lu sg, cao y (2005) communication routes within the taste bud by neurotransmitters and neuropeptides. chem senses 30 [suppl 1]:i37–i38 30. larson, e. d., vandenbeuch, a., voigt, a., meyerhof, w., kinnamon, s. c., & finger, t. e. (2015). the role of 5-ht3 receptors in signaling from taste buds to nerves. the journal of neuroscience: the official journal of the society for neuroscience, 35(48), 15984–15995. 31. lal s, cheng b, kaplan s, softness b, greenberg e, goland rs, lalla e, lamster ib. gingival bleeding in 6to 13-year-old children with diabetes mellitus. pediatr dent. 2007;29:426–30 32. ismail, a., mcgrath, c. & yiu, c. (2017). oral health status of children with type 1 diabetes: a comparative study: . journal of pediatric endocrinology and metabolism, 30(11), 1155-1159 33. sarmamy, h., saber, s., & majeed, v. (2018). the influence of type i diabetes mellitus on dentition and oral health of children and adolescents attending two diabetic centers in erbil city. zanco journal of medical sciences (zanco j med sci), 16(3), 204 212. 34. lamster ib, lalla e. periodontal disease and diabetes mellitus: discussion, conclusions, and recommendations. ann periodontol. 2001; 6:146-149. 35. bakhshandeh s, murtomaa h, vehkalahti mm, mofid r, suomalainen k. dental findings in diabetic adults. caries res. 2008; 42(1):14-18. 36. brikos c, o'neill la. signalling of toll-like receptors. handb exp pharmacol. 2008;183:21–50. 37. wang, h., zhou, m., brand, j., & huang, l. (2009). inflammation and taste disorders: mechanisms in taste buds. annals of the new york academy of sciences, 1170, 596–603 38. stetson db, medzhitov r. type i interferons in host defense. immunity. 2006;25:373–381. 39. ohnuki, m., ueno, m., zaitsu, t. et al. taste hyposensitivity in japanese schoolchildren. bmc oral health 14, 36 (2014). j. bagh. coll. dent. vol. 34, no. 3. 2022 rasool and diab 25 بين تأثير حساسية الطعم الحلو والمالح على صحة اللثة وعالقتها بالسيرروتونين اللعابي لدى مرضى السكرالنوع االول اللذين تتراوح اعمارهم العنوان: عاما 12-14 2بان صاحب دياب 1تبارك عادل رسول الباحثون: المستخلص: لسيروتونين أجريت هذه الدراسة على مرضى السكري من النوع األول بهدف تقييم حساسية الطعم الحلو والمالح وتأثيره على صحة اللثة وعالقته بمستوى ا :الهدف من الدراسة اللعابي عاًما والذين حضروا 14و 12أعمارهم بين تم اعتماد تصميم دراسة مقارنة شارك فيه األشخاص الذين تم تشخيص إصابتهم بمرض السكري و تتراوح :المواد وطرق العمل 70شخًصا( وتم مقارنتهم باشخاص غير مصابين بالسكري )المجموعة الضابطة 50مستشفى االطفال التعليمي بمعايير محددة في عينة الدراسة الحالية )مجموعة المرضى .العراق شخًصا( الذين حضرو وحدة طب األسنان في المستشفى الطبي في مدينة بغداد / والذي يتضمن ان يقدم كل مكون في خمسة تركيزات مختلفة لتقييم حساسية الطعم المالح والذوق الحلو ، وتم (two-alternative forced choice question) تم استخدام . ين. تم قياس حالة اللثة باستخدام موشر اللثةشخًصا من كل مجموعة ومطابقتها في العمر والجنس لتحليل اللعاب و قياس السيروتون 44اختيارعينة فرعية من وجود فرق أحصائي في كشف تحليل بيانات هذه الدراسة أنه لم يتم العثور على ارتباط كبير بين حالة مرض السكري وحساسية الطعم و التذوق. أظهرت البيانات عدم :النتائج . .في مرضى السكري مع اختالف مهم و لم تظهر أي عالقة احصائية مع حساسية الذوق متوسط مؤشر اللثة بينما كانت قيمة السيروتونين اللعابية أقل أن مستوى ضمن حدود هذه الدراسة. تم الوصول الى أن مرض السكري ليس له أي تأثير على حساسية الطعم المالح والحلو وعلى صحة الفم واللثة. في حين :االستنتاج ان أقل بين مرضى السكري. السيروتونين اللعابي كان له دور وك suhail f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 77 the effects of bisphosphonate administration on teeth development and growth of the jaw bones in neonatal rats (histological and immunohistochemical study) suhail labeeb hasoon, b.d.s. (1) nada m. h. al-ghaban, b.d.s, m.sc., ph.d. (2) abstract background: bisphosphonates are potent inhibitors of osteoclastic bone resorption and widely used for the treatment of osteoporosis, and osteogenesis imperfecta in children. clinical and experimental studies have demonstrated that bisphosphonates delay or inhibit tooth eruption. this study tries to focus on the effect of bisphosphonate on teeth development and jaw bones growth. materials and methods: the present study includes 65 neonatal rats during lactation period from 15 albino wister rats mother. alendronate (one type of bisphosphonates) was administrated orally (15 mg/kg) into 10 pregnant rats two times a week, while other 5 rats regard as control. then the neonatal rats sacrificed in i, 6, 11, 16 and 21 days. the lower first molar were examined histologically and immunohistochemical for amelogenin expression. biochemical serum analysis for calcium and alkaline phosphatase level were down for 11, 16 and 21days group. all histological, immunohistochemical, and biochemical results are compare with their controls. results: the histological results illustrate retardation in tooth and root development, impairment in maturation of enamel and retardation in tooth eruption of the first molar tooth germ in alendronate treated neonatal rats than their controls. also immunoreactivity for amelogenin at early stages of tooth development was somewhat more intense in experimental group than that in their controls .moreover, calcium and alkaline phosphatase serum levels in experimental rats are less than that of their controls. conclusion: this study concludes that treatment with alendronate during tooth development has the potential to inhibit tooth eruption, impair tooth formation, may induce some types of dental abnormalities, and increase the bone trabecule thickness by decreasing osteoclastic activity. key word: bisphosphonate, tooth development, amelogenin. (j bagh coll dentistry 2013; 25(special issue 1):77-82). introduction bisphosphonates (bps) are synthetic, nonhydrolyzable analogues of inorganic pyrophosphate, a naturally occurring compound in which 2 phosphate groups are linked by esterification (1). there are two groups of bisphosphonate both of them work in different way to suppress the osteoclastic activity: nitrogen containing and non-nitrogen containing (2). bisphosphonates promote the apoptosis of osteoclasts, its activity engaged in the degradation of mineral on the bone surface. such excessive resorption underlies several pathologic conditions for which bisphosphonates are now commonly used, including osteogenesis imperfecta and any other conditions involving fragile, breakable bone such as osteoporosis and malignancy metastatic to bone (3). alendronate is a potent nitrogencontaining bisphosphonate that become the primary therapy for managing skeletal conditions characterized by increased osteoclast-mediated bone resorption (4). amelogenin belongs to a family of extracellular matrix proteins. (1) master student. department of oral diagnosis, college of dentistry, university of baghdad (2) assistant professor. department of oral diagnosis, college of dentistry, university of baghdad the function amelogenin is not completely understood, it is believed to be in organizing enamel rods during tooth development. researches' indicates that this protein regulates the initiation and growth of hydroxyapatite crystals during the mineralization of enamel (5). although the mode of action of alendronate is mainly being investigated in bone, little is known about its effects on the formation of dental hard tissues. materials and methods the present study includes 65 neonatal rats during lactation period from 15 albino wister rats mother which were taken from the animal house of the national center of drug control and research in baghdad. the rat’s mothers were dividing into two groups: experimental group contain 10 mothers which administrate oral dose (15 mg/kg) (6) of sodium alendronate twice a week from first day of gestation to sacrifice day of neonatal rats, while control group contain 5 mothers which administrate with normal saline twice a week. blood samples were obtained from 11, 16 and 21 days neonatal rats in sacrificing day to find the alkaline phosphatase and calcium levels in both groups. then the neonatal rats were sacrificed in 1, 6, 11, 16, 21 days. the head separated from the body, blocked, and then processed for sectioning. the sections were j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 78 histologically studied by (h&e) stain and immunohistochemical study for amelogenin expression by (anti amelix anti body) from abcam company (ab59705). results clinical finding there are significant increases in size (weight & length) of control group when compared with alendronate-treated group especially in age group 6, 11, 16 days rats (figure 1,2). biochemical findings the biochemical serum analysis revealed that the level of calcium and alkaline phosphatase in alendronate treated rat are lesser than that of control rat (figure 3,4). histological & immunohistochemical findings the histological results of 1 day age group of this study are almost similar in both control and alendronate-treated groups and it shows that the 1st molar teeth germs are at advance bell stage (figure 5&6). 0 5 10 15 20 1 day 6 day 11 day 16 day 21 day 7.2 12 13 16 18.06 7.7 9 10.5 15.1 18.1 cont . ln exp.l n figure 1: mean length of neonatal rats in different groups 0 10 20 30 40 50 1 day 6 day 11 day 16 day 21 day 7.3 22.3 25.3 34.8 42.9 8.5 12.1 12.1 32 45 cont. wt exp. wt figure 2: mean weight of neonatal rats in different groups 0 2 4 6 8 10 12 11 day 16 day 21 day 10 11.1 11.05 8.1 9.1 9.3 co… figure 3: mean of calcium serum level of neonatal rats. figure 4: mean of alk serum level of neonatal rats in different groups. 0 20 40 60 11 day 16 day 21 day cont . exp figure 5: first molar 1 day tooth germ (control) show ameloblasts (am) , stellate reticulum (sr), stratum intermedium (si) and outer enamel epithelium (oee). h&e ×200. figure 6: first molar 1 day tooth germ (experimental) show odontoblasts (od), ameloblasts (am), stratum intermedium (si), stellate reticulum (sr), and outer enamel epithelium (oee). h&e ×100. j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 79 immunoreactivity for amelogenin illustrate that this protein was expressed in ameloblasts of 1 day experimental group somewhat more intense than that observed in controls (figure 7&8). histological and immunohistochemical pictures of 6 days group showed retardation in development and impairment in maturation of enamel of first molar tooth germ in experimental rats when compared with their controls (figures 9, 10). the same results of 6 days group are seen in 11 days group in addition to retardation of root formation of first molar tooth germ in experimental rats when compared with their controls (figures 11, 12, 13&14). figure 7: view of 1 day tooth germ (control) show positive expression of amelogenin in ameloblasts. dab stain with counter stain hematoxylin × 200. figure 8: view of 1 day tooth germ (experimental) show strong positive expression in ameloblasts. dab stain with counter stain hematoxylin ×200. figure 9: view of the first molar tooth germ of 6 days (control) show hard tissue formation. h&e ×40 figure 10: view of 6 days first molar tooth germ (experimental) show attachment of ameloblasts to the dentin without enamel matrix formation (red arrow). h&e 200. figure 11: view of 11 day first molar tooth germ (control) show positive expression of amelogenin in ameloblasts (am) and weak expression in enamel matrix (em) . dab stain with counter stain hematoxylin x200. figure 12: view of 11 days tooth germ (experimental) show negative expression of amelogenin in dentin (d) which attached directly to the ameloblasts (am) without enamel matrix (em) formation (arrow). dab stain with counter stain hematoxylin ×400. j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 80 in 16 days control rat show full crown formation, full thickness of dentin with maturation of enamel by presence of enamel space. ameloblasts will fuse with other layer of enamel organs and formed reduced enamel epithelium. while experimental group showed almost full dentin thickness and enamel matrix of the crown were formed, although the enamel matrix was not fully mature yet figure 15 & 16. the histological picture of the first molar tooth germ of 21 days experimental group illustrate that the tooth germ was still unerupted and root formation was short in length, when compared with their controls (figure 17 & 18). figure 13: view of first molar tooth germ 11 days (control) show the beginning of root dentin formation (arrow). bone trabecule (bt) surround the tooth germ. h&e ×100. figure 14: view of first molar tooth germ of 11 day experimental rat show the cervical loop (cv) and bone trabecule (tb) which surround the tooth germ. h&e × 200. figure 15: view of first molar tooth germ of 16 days control rat show odontoblasts (od), dentin (d), enamel space (es), reduce enamel epithelium (ree). h&e ×100. figure 16: view of tooth germ of 16 days old of experimental group show full formation of dentin (d) and enamel matrix (em). h&e × 200. figure 17: view of first molar tooth of 21 days (control) showed tooth at eruption stage, sulcular epithelium (se) which surround the gingival sulcus (g.s.). cementoenamel junction (cej). h&e x25. figure 18: view of first molar tooth germ of 21 days experimental rat show unerupted tooth. enamel matrix (em) surround by ameloblasts (am), bone trabecule surround the crown (bt). h&e ×100. j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 81 there are positive amelogenin expressions in osteoblast, osteocyte and bone matrix of both controls and experimental. the bone sections of control rats express amelogenin more than that of experimental group in almost all age groups (figure 19 & 20). in general, the present study showed that the periodontal ligament fibroblasts were positively expresses the amelogenin in both control and alendronate-treated groups especially in 21 days group (figure 21 & 22). discussion the clinical findings of the present study showed that the alendronate treated neonatal rats were smaller in length and weight than their controls especially in rats of 6, 11, and 16 days old. these findings are due to decrease mothers activities as side effects of alendronate intake (7). the biochemical serum analysis of the present study revealed reduction in the level of calcium and alkaline phosphatase in alendronate-treated neonatal rats than that of controls this reduction may result from decrease of bone turn over due to inhibition of osteoclastic activity by this medication. this result is in agreement with iwamoto et al(8) . the histological feature of tooth development in one day rats are almost similar in figure 19: view of bone section (control) show positive expression of amelogenin in bone matrix (bm), osteoblast (ob), osteocyte (oc). dab stain with counter stain hematoxylin ×400. figure 20: view of first molar tooth germ 21 days (experimental) show positive expression of amelogenin in bv of the pulp (red arrow), cementoblasts (cb) and fibroblasts of pdl (arrow). negative expression was shown in bone trabecule (bt). dab stain with counter stain hematoxylin ×200. figure 21: view of first molar erupted tooth 21days control rat show the positive expression of amelogenin in cementoblasts (cb), odontoblasts (od) and predentin (pd), and fibroblasts of periodontal ligament (pdl). dab stain with counter stain hematoxylin ×400. figure 22: view of first molar tooth germ 16 days experimental rat show positive expression of amelogenin in bv of the pulp (red arrow), odontoblasts (od), cementoblasts (cb) and fibroblasts of pdl (arrow). negative expression was shown in bone trabecule (bt). dab stain with counter stain hematoxylin ×200. j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 82 both alendronate treated and control groups, this agree with massa et al (9). immunoreactivity for amelogenin illustrate that this protein was expressed in ameloblasts of alendronate-treated somewhat more intense than that in their controls (9). at six days group the ameloblasts in control rats are well differentiated, good layer of enamel matrix. while in alendronate treated rats show absence of enamel matrix in some area due to the effects of alendronate on ameloblasts function during amelogenesis. this finding agrees with fuangtharnthip et al (10). immunoreactivity for amelogenin was somewhat more intense in enamel matrix of alendronate-treated than that in the control. it also diffused through the dentin matrix toward the layer of odontoblasts and accumulated in the predentin, assuming an ectopical deposition clearly visible in the alendronate-treated group (11). at 11 days old, the control group shows full thickness of enamel matrix formation with the beginning of enamel maturation. while in the alendronate treated rats there was loss of enamel matrix in some area due to the effects of alendronate on ameloblasts function during maturative stage of amelogenesis. this results agree with hiraga et al(12). the immunoreactivity shows weak expression of amelogenin in the enamel matrix of control and experimental groups due to maturation of enamel matrix (11). at 16 day old, the control group show full thickness of crown formation and maturation while in alendronate treated group the enamel matrix is not fully mature yet. this agrees with massa et al (9). the amelogenin expression revealed almost the same result for both groups, which agree with previous study (13). at 21 days old control rat teeth were erupted in the oral cavity and the root 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(ivsl) 13. haze a, taylor a, blumenfeld a, rosenfeld e, leister y, dafni l, shay b, gruenbaum-cohen y, fermon e, haegewald s, bernimulin j. amelogenin expression in long bone and cartilage cells and in bone marrow progenitor cells. the anatomical record 2007; 290:455– 460. tariq f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 shear bond strength pedodontics, orthodontics and preventive dentistry167 shear bond strength of stainless steel brackets bonded to porcelain surface treated with 1.23% acidulated phosphate fluoride gel compared to hydro fluoric acid with silane coupling agent (in vitro comparative study) tariq m. m. al-najjar, b.d.s. [1] fakhri a. ali, b.d.s, m.sc. [2] abstract background: with the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.the present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). materials and methods: the samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). they were divided as the following: group i (control): the porcelain surface left untreated and glazed, group ii (diamond bur group): the porcelain surface was treated with fine diamond bur at speed of 350000 rpm for 20 seconds, group iii (red stone bur): the porcelain surface was treated with coarse red stone bur at speed of 8500 rpm for 20 seconds. each group consists of 20 samples, then each group subdivided into two subgroups; one treated with acidulated phosphate fluoride 1.23% and the other subgroup treated with hydrofluoric acid 9 % with silane coupling agent. results: the result of this study revealed that there was very high significant difference among all tested groups and the highest shear bond strength was for diamond bur group with hfa and silane (8.67 mpa), the 2nd highest strength was for control group with hfa and silane (7.52 mpa), the 3rd was (7.38 mpa) in red stone bur with hfa and silane, the least shear bond strength values were obtained for subgroups treated with acidulated phosphate fluoride gel 1.23%. conclusions: the most reliable procedure for bonding orthodontic brackets to the porcelain surfaces is through the surface treatment combinations of mechanical roughening by using diamond bur, 9% hydrofluoric acid and silane coupling agent application. key words: acidulated phosphate fluoride, hydrofluoric acid, silane coupling agent, feldspathic porcelain. (j bagh coll dentistry 2013; 25(special issue 1):167-173). introduction dental porcelain is a popular restorative material, especially for adult patients, where it is used for restorations such as veneer, crown, and bridge. as the demand for adult orthodontic treatment increases, orthodontists are more likely to deal with the problem of placing brackets on teeth restored with porcelain. conventional acidetch technique is not effective in preparation of non-enamel surface for mechanical retention of orthodontic attachment (1). silane was used as a coupling agent to increase the bond strength to either glazed or roughened porcelains in many studies, but there is a tendency for cohesive failure of porcelain during the debonding process. additionally, the limited shelf-life time of silane causes a problem for orthodontists when finding it expired without other spare bottles (2-5). mechanical roughening with the fine or coarse diamond burs and sandblasting were reported to provoke crack initiation and propagation within the porcelain (6). [1] m.sc. student, department of orthodontics, college of dentistry, university of baghdad. [2] professor, department of orthodontics, college of dentistry, baghdad university. since the restorations usually remain in the mouth after debonding the brackets, porcelain damage due to extreme roughening of the surfaces during pretreatment or debonding must be avoided (7). hydrofluoric (hf) acid and acidulated phosphate fluoride gel (apf gel) was reported to facilitate micromechanical retention (8, 9). both acids can etch glass or porcelain and thus create a mechanically retentive surface (10). nelson and barghi found that an apf gel etching produced bond strength comparable to an hf acid etched control. in their study, a 10-minute etch produced the highest bond strength for apf gel whereas the control was etched 1-minute with 10% hf acid. despite its effectiveness, the hazards of hf acid are well recognized. mucosal contact with hf can cause erythema and burning associated with loss of tissue, along with intense pain for several days (11,12). to our knowledge, there is no published study available in the searched data base which directly investigates the bond strength of metal bracket to porcelain surface prepared by 1.23% apf gel as compared to silane coupling agent using feldspathic porcelain which is different j bagh college dentistry vol. 25(special issue 1), june 2013 shear bond strength pedodontics, orthodontics and preventive dentistry168 form the porcelain used in denture teeth that were used by most previous studies. we intend to calibrate our samples according to the surface micro hardness not by just their physical properties (13,14). materials and methods seventy two molds were fabricated from metal fused to ceramic (vita 3d master), each sample (figure 1) was checked under magnification (10 x) for any roughness, bubbles or irregularities, then 12 samples were taken after porcelain firing to test for micro-hardness in order to make sure that all the samples have similar mechanical properties in macroand microlevel (15,16). the selection for the hardness testing group was performed randomly by taking one sample from each firing group (6 samples), so the total number was 12 samples from 72 samples (16). the remaining sixty models were divided into 3 groups, 20 molds each, the first group is the control group the 2nd and 3rd group were treated mechanically by high speed turbine diamond bur and low speed red stone bur, respectively. then the groups subdivided into two subgroups (apf 1.23% and silane), 10 mold each. subgroup apf 1.23 % was treated by acidulated phosphate fluoride 1.23 %, while subgroup silane was treated by hydrofluoric acid and silane coupling agent. figure 1: ceramic fused to metal model used in the study. construction of the metal models seventy two wax molds were fabricated by one dental technician in rectangular shape (28 mm * 15mm*28mm) by using base plate sheet wax ,then each three models sprued together in order to make the investment mold pattern. after that the sprued wax models were placed inside rubber ring and molded to the cover of the ring, the investing procedure was performed on the vibrator and layer by layer to avoid the bubble formation according to the manufacturers’ instructions. the ring would be then left for 10 minutes for setting according the manufacturer's instructions then it would be placed inside wax oven and at temperature of 280 c° for 30-40 minutes to remove the wax completely from the investment mold (wax burn-out). then the ring was placed in the electric centrifuge machine (deguzza, germany) for metal casting procedure and the mold would be then left for cooling. then the metal models removed from the investing ring and grinded from the main sprue to be separated from each other and sandblasted by using alumina oxide particles (250 µm) to remove the investment remnant particles, then finished by using special laboratory carbide and diamond burs using micro motor at a speed of 500000 rpm (figure 2). figure 2: finished metal mold building and firing of porcelain after the metal models were prepared and finished ,the process of porcelain building was started by painting the metal with opaquer layer and firing for 15 minutes at a temperature of 950 c°, after that building the ceramic layer 2mm in thickness and firing for 18 minutes at temperature of 930c°. the firing process was made by using ivoclar ceramic oven, model p300, germany. the model then should be grinded and finished by special burs, after that painted with glaze layer and fired at 920 c° for 15 minutes (16). vickers hardness test one model was taken from each firing group (6 models), so twelve models were chose for the vickers hardness test machine in the university of technology in baghdad, (figure 3). six microindentation were made on each sample and vhn (vickers hardness number) was measured. this is to ensure that all the samples used in the study have nearly the same mechanical properties. figure 3: vickers micro-hardness test machine sample grouping the specimens were divided according to porcelain surface treatment into apf 1.23% and silane. group apf 1.23 %: the specimens were treated by using the apf 1.23 % for 10 minutes (17).group silane: the specimens were treated by j bagh college dentistry vol. 25(special issue 1), june 2013 shear bond strength pedodontics, orthodontics and preventive dentistry169 using hydrofluoric acid and silane coupling agent. group (i) control group: the porcelain surfaces were left as they came from the dental lab; glazed porcelain. group (ii): the porcelain surfaces were treated mechanically by using tapered diamond bur at speed of 320000 rpm, for 20 seconds with water spray, and then dried for 20 seconds with oil free air. group (iii): the porcelain surfaces were treated mechanically by using stone bur with low speed straight hand piece for 20 seconds at speed of 85000rpm, and then the specimens were dried with oil free air for 20 seconds. bonding procedure the bonding was done by applying a thin layer of bonding agent on the labial porcelain surface using a disposable brush, and then an equal amount of the light cure composite was applied on the bracket base according to the manufacturer instructions, which was then positioned in the center of the model using a clamping tweezers. then a constant load of 300 grams was applied by pressure tension gauge(after a modification done in its end in order to have a flat surface to prevent bracket dislodgement during loading) which placed on the bracket at 90°for 10 sec.(17,18), to ensure that each bracket was seated under equal force. any excess bonding material was carefully removed from around the bracket base with a sharp hand scaler without disturbing the seated bracket. shear bond strength test shear test was accomplished using tinius olsen universal testing machine (figure 4) with loading cell 50 kilogram and a crosshead speed of 0.5 mm/min (19, 20). each sample was seated in the mounting metal vice and placed on the base of the testing machine (which was parallel with the horizontal plane). the chisel end rod was fitted inside the upper arm of the testing machine with its chisel end downward parallel to the bonded porcelain labial surface to apply a force in a gingivo-incisal direction of the bracket that produce a shear force at the bracket base/ porcelain surface interface, until debonding occurs. when the bracket was debonded from the porcelain labial surface by the force applied from the testing machine, the ultimate magnitude of the reading was taken; this force was measured in kilograms and converted into newton according to the following equation: force (n) = load (kg) x ground acceleration (9.8 m/sec.). then the force was divided by bracket base surface area (10.9 mm²), which was taken from the manufacturer to get the strength value in mega pascal (mpa) units. each debonded bracket was kept with its corresponding porcelain surface to estimate the adhesive remnant index. figure 4: tinius olsen universal testing machine. results vickers hardness test hardness test was performed to the ceramic surfaces of the samples used in this study in order to confirm that all the groups had the same mechanical property although that these samples were baked in different production time. the load used was 900 grams (0.9 kg) for 15 seconds on the top of each sample surface make the indentation, this indentation then measured under the microscope of the micro tester, the vhn (vickers hardness number) was calculated by special equation: vhn= 1.8544 * (16) where p is the load value, d average is the mean of the six indentations made and (1.8544) is a constant value. this equation was used for each sample to get the vickers hardness number and it was performed by a program incorporated inside the digital micro tester. descriptive statistics of the surface hardness descriptive statistics were performed including mean, standard deviation and error for all tested samples, and then kruskal wallis test was used. there was statistically no significant difference among all the groups (p= 0.44). all the samples have similar mechanical property of the porcelain surface although they were baked in different production times, (table 1). j bagh college dentistry vol. 25(special issue 1), june 2013 shear bond strength pedodontics, orthodontics and preventive dentistry170 table 1: descriptive statistics of the vhn descriptive statistics kruskal wallis test mean s.d. s.e. χ2 d.f. p-value vhn 221.18 10.003 2.89 11 11 0.44 table 2: descriptive statistics and groups differences variables descriptive statistics group difference control diamond bur red stone bur anova test mean s.d. s.e. mean s.d. s.e. mean s.d. s.e. f-test p-value sig. apf 0.97 0.09 0.03 4.94 0.45 0.14 6.18 0.51 0.16 470.04 0.000 hs silane 7.52 0.75 0.24 8.67 0.56 0.18 7.38 0.64 0.2 11.57 0.000 hs t-test -27.39 -16.37 -4.65 d.f.=29 d.f. 18 18 18 p-value 0.000 0.000 0.000 sig. hs hs hs descriptive statistics of shear bond strength (figure 5) the descriptive statistics were performed for all variables, which include two types of etching systems (acidulated phosphate fluoride 1.23 % and hydrofluoric acid) on two types of porcelain surfaces (glazed and mechanical treated surface). these statistics included, mean, standard deviation, standard error. the shear bond strength values for all tested samples were expressed in mega pascal (mpa) and are displaced in (table 2). in the control group (glazed porcelain surface), the (apf 1.23 % and silane coupling agent) samples showed very high significant difference (p-value = 0.000), apf 1.23% had mean shear bond strength 0.97±0.09 mpa, while silane group had shear bond strength 7.52±0.75 mpa. in the other groups (two types of mechanical treatment), there was high significant difference with both etching systems (p-value = 0.000), the diamond bur group showed mean shear bond strength = 4.94±0.45 mpa with apf 1.23 %, while with silane and hf it showed 8.67 ± 0.56 mpa shear bond strength. the red stone bur group showed also high significant difference (pvalue = 0.000) between the apf1.23% and silane etching systems, for the 1st it was 6.18 ±0.51 mpa and for the 2nd it was 7.38±0.64 mpa, respectively. mode of failure site the sites of bond failure of all tested groups are shown in (figure 6). figure 5: mean shear bond strength of all tested groups figure 6: adhesive remnant index of total samples. adhesive remnant index according to ärtun and bergland (1984) was as following: score (0) in 100 % of the control group (glazed porcelain) treated with apf 1.23%, in 50% of the 2nd group (diamond bur group) and 40 % in 3rd group (red stone bur). score (i) was not noticed in any of the tested groups score (ii) in 60 % of the control group (glazed porcelain) treated with hf + saline, and 3rd group (red stone bur) treated with apf 1.23 %, in 50 % of the 2nd group (diamond bur) treated with apf 1.23 %, in 30 % of 3rd group (red stone bur) treated with hf+ silane, and only 20 % of the 2nd group (diamond bur) treated with hf + silane. score(iii) in 40 % of the control group (glazed porcelain) , in 80 % in 2nd group (diamond bur ) j bagh college dentistry vol. 25(special issue 1), june 2013 shear bond strength pedodontics, orthodontics and preventive dentistry171 ,and in 70 % of the 3rd group(red stone bur) ,all treated with hf+ silane. chi square test was used for such non parametric data and the statistical analysis showed very high significant difference among all tested groups (glazed porcelain, diamond bur, and red stone bur) with p-value = 0.000. discussion shear bond strength there are few scientifically based recommendations in the literature for minimum orthodontic bracket shear bond strength. whitlock et al. (22) suggested that 6-8 mpa was adequate for orthodontic attachments to endure the course of treatment and sufficiently weak to preserve the porcelain restoration following bracket removal (22). one of the aims of this study is to evaluate the effectiveness of different surface conditioning methods on the shear bond strength of stainless steel brackets bonded to porcelain as follow: 1. glazed porcelain (control group) the samples of the control group were divided into two subgroups; the 1st was etched by using apf 1.23% for 10 minutes and these showed bond failure at 0.97mpa ± 0.09 s.d.(table 2) , similar results with the same methodology used in the present study were recorded by other previous studies (9,23,24). the premature loss of the brackets was occurred due to the fact that the apf 1.23% could not do etching to the glazed porcelain. it simply cleans the surface and hydrolyzes the silica of porcelain in the same time preserving the intact smooth surface of the porcelain. the 2nd subgroup was etched by using hfa 9% for 2 minutes according to the manufacturer’s instructions, and then porcelain primer (silane coupling agent) was used. it showed 7.52 mpa ± 0.75 s.d. and this is considered the 2nd highest value of mean shear strength among all tested group in the present study. these results agree with other researchers (17,25) who found that porcelain preparation with hfa etching followed by silane application, resulted in high shear bond strength. the significant increase in bond strength is due to the effect of hfa by facilitating micro-retention and the silane coupling agent which provide a chemical link between organic resin compound and inorganic porcelain compound. 2. mechanical surface treatment of porcelain: a. roughening by diamond turbine bur. samples of this group also divided into two subgroups; 1st subgroup etched by apf and the other by hfa 9%. the 1st subgroup was etched for 10 minutes, this subgroup showed shear bond strength of (4.94 ± 0.45 s.d) with very high significant difference from other subgroups of same surface treatment. the increase in shear bond strength value may be due to the surface roughness more than that of apf micro etching. depending on previous studies in the literature (26); scanning electron microscope showed that diamond bur removed the glaze completely leaving islands and tunnels of rough porcelain that of course increases bond strength. the 2nd subgroup was etched by hfa 9% for 2 minutes according to the manufacturer´s instructions then a porcelain primer added (silane coupling agent). the shear bond strength was 8.67±0.56 s.d. which is the highest value among all the tested groups in the present study. this high value may be due to the fact that roughening the porcelain causing islands and tunnels as shown in sem (26), also the hfa removes the glassy and crystalline layer from porcelain which depends on its concentration and 9 % was found to be so efficient. the high shear bond strength of this subgroup comes from mechanical retention and chemical bonding. these results coincides with other studies (25,27),while disagrees with others (1,8) who found that there is no significant difference between the hfa and other agents and suggested the main bond strength comes chemically from silane . b. roughening by using red stone bur. samples of this group also divided into two subgroups; one etched by apf1.23 % and the other by hfa 9%. the 1st subgroup (apf 1.23 %) showed remarkably higher shear bond strength which was 6.18±0.51 s.d. when compared with the pervious subgroups of the same etching system. this may be due to the micro and macro etching done by rough stone bur. roughening the porcelain surface with coarse bur produces random peeling appearance, thus enlarging the porcelain surface with only shallow mechanical retention as revealed by sem, although macroscopic appearance of the rough porcelain gives the impression of high retention surface. besides ,the apf 1.23% could help in the chemical bonding to porcelain. this result agrees with some studies (9) while, disagrees with others (28,29), who found that j bagh college dentistry vol. 25(special issue 1), june 2013 shear bond strength pedodontics, orthodontics and preventive dentistry172 etching with apf, might be enough for bonding on porcelain. the difference may be due to varieties in etching times, concentration, type of porcelain used, storage media, and adhesive agent used. the findings of the present study agrees with the results in the literature (26) who found that there was no significant difference between using hfa and roughening at the same time especially with red stone bur, while disagrees with others (1) who stated that the roughening showed the highest shear bond strength among all other conditioning methods. clinically, the method of choice to improve the bond strength to porcelain surface will be probably the one that provides sufficient shear bond strength to porcelain surface however, this choice will also depend a lot on the patient´s oral function and para functional habits and the orthodontist´s mechanics in tooth movements. the continuously increasing load applied in vitro is not the same type of stimulus that occurs clinically. bonded brackets are subjected to shear, tensile, torsion, and combination of these forces. except for traumatic incidents, brackets coming loose in the mouth as a result of repeated stresses that produce micro cracks that propagate until bond failure occurs. type of debonding force in the machine is not the same as force applied in careful clinical debonding so the risk of damaging the porcelain surface need not to be a great problem with gentle, still effective manual technique. from the results of the present study, we advise the use of mechanical surface treatment with diamond turbine bur and using hydrofluoric acid 9 % with silane coupling agent as an effective method for bonding the metal brackets to porcelain especially when heavily tooth movement and/or long treatment duration or patient presents with para functional habits. as an alternative method we advise to use low speed red stone bur with apf 1.23 % or hfa + silane coupling agent or to do direct etching with hfa to the glazed porcelain with the use of silane coupling agent ,this is applicable for short duration treatment or light tooth movements required. references 1. schmage p, nergiz i, herrmann w, özcan m. influence of various surface-conditioning methods on the bond strength of metal brackets to ceramic surfaces. am j orthod dentofacial orthop 2003; 123:540-6. 2. newman sm, dressler kb, grenadier mr. direct bonding of orthodontic brackets to esthetic restorative materials using a silane. am j orthod 1984; 86: 503-6. 3. smith ga, mcinnes-ledoux p, ledoux wr, weinberg r. orthodontic bonding to porcelain — bond strength and refinishing. am j orthod dentofac orthop 1988; 94:245-52. 4. zachrisson bu, buyukyilmaz t. recent advances in bonding to gold, amalgam, and porcelain. j clin orthod1993; 27: 661-75 5. nebbe b, stein e. orthodontic brackets bonded to glazed and deglazed porcelain surfaces. am j orthod dentofacial orthop 1996; 109: 431-6. 6. diaz-arnold am, wistron dw, aquilino sa,swift ej. bond strengths of porcelain repair adhesive systems. am j dent 1993; 6: 291-4. 7. eustaquio r, laforrest dg, moore bk. comparative tensile strengths of brackets bonded to porcelain with orthodontic adhesive and porcelain repair. am j orthod 1996; 95(6): 508-12. 8. aida m, hayakawa t, mizukawa k. adhesion of composite to porcelain with various surface conditions. j prosthet dent 1998; 73: 464-70. 9. barbosa vl, almeida ma, chevitarese o,keith o. direct bonding to porcelain. am j orthod dentofacial orthop 1995; 107(2):159-64 10. tylka df, stewart gp. comparison of acidulated phosphate fluoride gel and hydrofluoric acid etchants for porcelain-composite repair. j prosthet dent 1994; 72: 121-7. 11. kirkpatrick jj, enion ds, burd da. hydrofluoric acid burns: a review. burns 1995; 21: 483-93. 12. fujimoto k, yasuhra n. burns caused by dilute hydrofluoric acid in the bleach. j nippon med sch. 2002; 69: 180-4. 13. stokes an, hood jaa, tidmarsh bg. surface preparation for bonding to porcelain and gold. austr orthod j 1989; 9: 321-3 14. morena r, lockwood pe, fairhurst cw. fracture toughness of commercial dental porcelains. dent mater 1986; 2: 58-62. 15. bishara se, soliman mm, oonsombat c, laffoon jf, ajlouni r. the effect of variation in mesh-base design on the shear bond strength of orthodontic brackets. angle orthod 2004; 74(3): 400-4. (ivsl). 16. suchon vatarugegrid ,smorntree viteporn ,shear-peel bond strength of metal bracket to porcelain surface treated with 1.23% acidulated phosphate fluoride gel.cu dent j 2010; 33:109-18 17. ajlouni r, bishara se, oonsombatc c, solimand m, laffoone j. the effect of porcelain surface conditioning on bonding orthodontic brackets. angle orthod 2005; 75(5): 858-864. 18. bishara se, ostby aw, laffoon jf, warren jj. enamel cracks and ceramic bracketsfailure during debonding in vitro. angle orthod 2008; 78(6): 117883. 19. millet dt, letters s, roger e, cummings a, love j. bonded molar tubes-an in vitro evaluation. angle orthod 2001; 71(5): 3805. (ivsl). 20. sharma-sayal sk, rossouw pe, kufkami gv, titley kc. the influence of orthodontic bracket base design on shear bond strength. am j orthod dentofacial orthop 2003; 124: 74-82. 21. polat o, karaman ai, buyukyilmaz t. in vitro evaluation of shear bond strengths and in vivo analysis of bond survival of indirectbonding resins. angle orthod 2004; 74: 405409. (ivsl). 22. whitlock bo 3rd, eick jd, ackerman rj jr, glaros ag, chappell rp. shear strength of ceramic brackets j bagh college dentistry vol. 25(special issue 1), june 2013 shear bond strength pedodontics, orthodontics and preventive dentistry173 bonded to porcelain. am j orthod dentofacial orthop 1994; 106(4): 358-64. 23. zachrisson yǿ, zachrisson bu, büyükyilmaz t. surface preparation for orthodontic bonding to porcelain. am j orthod dentofacial orthop 1996;109:420-430 24. larmour cj, bateman g, stirrups dr. an investigation into the bonding of orthodontic attachments to porcelain. eur j orthod 2006; 28(1):747. 25. kocadereli i, canay s, akca k. tensile bond strength of ceramic orthodontic brackets bonded to porcelain surfaces. am j orthod dentofacial orthop 2001; 119: 617-620. 26. faltemeier a, behr m, müssig d. a comparative evaluation of bracket bonding with 1, 2, and 3 component adhesive systems. am j orthod dentofacial orthop 2007; 132(2): 144. 27. thurmond jw, barkmeier ww, wilwerding tm. effect of porcelain surface treatments on bond strengths of composite resin bonded to porcelain. j prosthet dent 1994; 72:355-9. 28. wunderlich rc, yaman p. the "in vitro" effect to topical fluorides on dental porcelain. j dent res 1985; 64(special issue): 296 (abst 1093). 29. jones da. effects of topical fluoride preparation on glazed porcelain surfaces. j prosthet dent 1985; 53: 483-4. aqeel.doc j bagh college dentistry vol. 28(1), march 2016 the prevalence of oral diagnosis 73 the prevalence of impacted maxillary canine among iraqi patients of al-basrah city aqeel ibrahim lazim, b.d.s, m.sc. (1) abstract background: impacted teeth are frequent problem and one of the most affected teeth is the maxillary canine. the early diagnosis of impacted canines by radiographic evaluation is imperative. the aim of this study was to determine the prevalence of impacted maxillary canines in patients attending the oral diagnosis and radiology clinic in college of dentistry, university of al-basrah. materials and methods: 1280 patients attending the oral diagnosis and radiology clinic in college of dentistry university of al-basrah, between october 2013 and march 2015 were examined for the study. the age of the patients ranged from 15 to 55 years, with a mean age of 22.2 years. results: the prevalence for maxillary impacted canines in all the cases was found to be 2.7%.the prevalence of impacted canines in males was 2.3% and in females was 3.2%. a higher number of impaction was seen on the left side of the maxillary arch; 57.1% compared to 37.2% on the right side. unilateral impaction was seen in 94.3% whereas the bilateral impaction occurs in only (5.7%) of the patients. conclusions: the prevalence of impacted maxillary canine in people attending the college of dentistry, university of al-basrah is 2.7%. keywords: canine, impaction, prevalence. (j bagh coll dentistry 2016; 28(1):73-77). introduction impacted teeth are those with delayed eruption time or that are not expected to erupt completely based on clinical and radiographic assessment (1). the eruption of permanent teeth includes series of events, mostly genetically based, whereby tooth germ eruption taking place at a predetermined time and path enables the tooth to find its antagonist at the occlusal plane. as the eruption is a complex process, it is not uncommon that problems may arise, which lead to failure of eruption. (2,3). impacted teeth could result in many problems such as compromising tooth movement, esthetics, and function. maxillary canines are the last teeth to develop in anterior maxilla and have the longest period of development. they also have the longest and most devious path of eruption from the formation point which lies lateral to the pisiform fossa to its final position in the dental arch (4,5). failure of the eruption of permanent maxillary canine is a common dental anomaly. after the third molars, maxillary canine is the second most commonly impacted tooth. they can be impacted either unilaterally (figure1) or bilaterally (figure 2), facially or palatally and are predominantly seen in females (6). the following factors could participate in canine impaction: (1) discrepancies between tooth size and arch length (2) abnormal position of the tooth bud (3) the presence of an alveolar cleft (4) ankylosis (1)assistant lecturer. department of oral diagnosis. college of dentistry, university of al-basrah (5) delayed shedding or early loss of the deciduous canine. (6) cysts or tumors in premaxilla (7) root dilaceration (8) iatrogenic causes. (9) idiopathic condition with no apparent etiology. (7,8) shafer et al.(9) suggested the following sequelae for canine impaction: (1) malpositioning of the impacted tooth either labially or lingually. (2) migration of the neighboring teeth and loss of arch length. (3) internal resorption. (4) dentigerous cyst formation. (5) external resorption of root of the impacted tooth and/or the neighboring teeth. (6) infection particularly with partially erupted canine. (7) referred pain. the exact position and localization of these teeth are important factors in planning the treatment procedures. methods of diagnosis that may allow for early detection and prevention of impaction should include a proper family history, clinical examinations including palpation by the age of 9-10 years and a thorough radiographic evaluation, the panoramic radiography is of a great clinical significance, to establish the correct treatment plan (10,11). the objective of the present study was to determine the prevalence of impacted maxillary canine in a sample of patients attending the oral j bagh college dentistry vol. 28(1), march 2016 the prevalence of oral diagnosis 74 diagnosis and radiology clinic in college of dentistry, university of al-basrah. materials and methods the sample of the present study was 1280 patients attending the oral diagnosis clinic in college of dentistry, university of basrah, between october 2013 and march 2015. thorough medical history, past dental history, clinical examination and panoramic radiographs for the patients were performed by a specialist dentist. the age of the patients ranged from 15 to 55 years, with a mean of 22.2 years. any patient with one of the following conditions was excluded from the study: 1patients under 15 years old (no complete dentition). 2history of extraction of the permanent maxillary canine. 3history of orthodontic treatment. 4patients with a history of pathological conditions (like cysts and tumors) within premaxilla. 5history of trauma to the anterior teeth, or fracture of the jaw that might have affected the normal growth of permanent dentition 6history of hereditary diseases or syndromes such as down's syndrome or cleidocranial dysostosis. after intraoral examination, patients with clinical indication for panoramic radiograph were referred to radiology unit for panoramic radiographs. the indications included: 1. crowding of upper and/or lower teeth. 2. malocclusion. 3. pain associated with partially erupted lower and/or upper third molar which couldn’t be completely depicted by use of introral radiographs. 4. tempromandibular joint disorders. 5. recent trauma to one or both jaws (except trauma to premaxilla). all panoramic radiographs were taken with the vatech digital panoramic x-ray machine (pax-400c), south korea. exposure settings were determined according to patient’s age and body size and weight, kvp from 60-68 kv , ma ranges from 4-8 ma and exposure time was 18 seconds. the magnification factor was 1.2. the researcher has examined the radiographs at the same time on hplcd screen (17 inches) to determine the impacted tooth. maxillary canines could be prevented from eruption by an obstruction on its path by an unexfoliated deciduous canine, an erupted permanant tooth, supernumerary tooth, odontome, alveolar bone, or soft tissue (as fibrous ridge mucosa). when the maxillary canine root was completed and it was not reaching its supposed position within the dental arch clinically and radiographically, it was defined as impacted. figure 1: panoramic image showing unilateral impacted maxillary canine j bagh college dentistry vol. 28(1), march 2016 the prevalence of oral diagnosis 75 figure 2: panoramic image showing bilateral impacted maxillary canine results a total number of 1280 panoramic images was included in the present study (table 1), 585 of them were males (45.7%) and 695 were females (54.3%). a total no. of 35 impacted maxillary canines were found 19 (54.2%) of which were in 18 females and 16 (45.8%) in males (table 2, figure 3). the prevalence of impacted canines in males was 2.3% and in females was 3.2%. the prevalence for maxillary impacted canines in all the cases was found to be 2.7%. a higher number of impaction was seen on the left side of the maxillary arch; 20 impacted canines (57.1%) (9 in males and 11 in females) compared to13 impacted canines (37.2%) on the right side (6 in males and 7 in females), whereas the bilateral impaction occurred in 2 patients only (5.7%) of the patients, which is less common than the unilateral impactions, which accounted for 94.3% of the total cases (table 3, figure 4). table 1: distribution of patients according to gender gender no. percentage male 585 45.7 female 695 54.3 total 1280 100 table 2: distribution of impacted canines according to gender gender no. percentage prevalence% male 16 45.8 2.3 female 19 54.2 3.2 total 35 100 2.7 0 10 20 30 40 50 60 70 80 90 100 no. percentage prevalence% male female total figure 3: distribution of impacted canines according to gender j bagh college dentistry vol. 28(1), march 2016 the prevalence of oral diagnosis 76 table 3: distribution of patients with impacted canines gender side right left bilateral male no. 6 9 1 % 37.6 56.2 6.2 female no. 7 11 1 % 36.8 57.9 5.3 total no. 13 20 2 % 37.2 57.1 5.7 0 10 20 30 40 50 60 no. % no. % no. % male female total side right side left side bilateral figure 4: distribution of patients with impacted canines discussion the present study indicated that the prevalence for maxillary impacted canines in all the cases was found to be 2.7%, which is near to that reported by sajnani and king study (12) who reported a prevalence of 2.1% on a sample of chinese population, also ericson and kurol (13) revealed that the rate of impaction of maxillary canines was in the range of 0.9-2 %. patil and his colleagues (14) reported that the prevalence of impacted maxillary canine on a sample of western indian population was 2.9%, although another iraqi study by altaee (15) reported a higher frequency for maxillary canine impaction; 4.6%, .another indian study made by sridharan et al., (2) also found a higher prevalence of impacted maxillary canine than what was found in the present study, they reported a prevalence of 3%. the prevalence of impacted canines as seen in the present study in females was 3.2% which is higher than that found in males (2.3%); this agrees with most of studies about impacted maxillary canine; for example altaee (15) in her study on patients from ramadi city in iraq stated that female: male ratio was 2:1. sridharan et al., (2) found prevalence of 2.6 % in males and 3.6 % in females. topkara and sari (16) also found that the prevalence ratio in females was higher than that in males (1.3:1). also it agrees with what was reported by kifayatullah et al., (17) who reported a higher ratio in female as compared to male (1.85:1), also pati et al., (14) found that the prevalence of canine impaction was higher in females (3.6%) compared to males (2.3%). on the other hand, it was 2.4:1 in greek population according to the study of fardi et al., (18). altaee (15) tried to explain the higher female: male ratio for canine impaction by the higher percentage of females who seeks dental treatment, smaller arch width in female in comparison to male could participate in this trend. concerning the side distribution in the present study, a higher number of impaction was seen on the left side of the maxillary arch; 57.1% compared to 37.2% on the right side, and this agrees with most of the studies about impacted maxillary canine as the study of patil et al., (14) who reported also a higher prevalence on the left side 73% while it was only 20% on the right side. a study on turkish population carried out by topkara and sari (16) found that the left and right distribution of impacted maxillary canine was 52.5% and 47.5% respectively. in the present study, unilateral impaction was seen in 94.3% whereas the bilateral impaction occurred in only (5.7%) of the patients. other studies found different ratios for bilateral impaction, patil et al., (14) in a study on indian population established a 6% bilateral impaction j bagh college dentistry vol. 28(1), march 2016 the prevalence of oral diagnosis 77 for maxillary canine which is approximating the ratio reported in the present study, whereas other researchers as sajnani and king (12) in a study on chinese children have reported a bilateral impaction ratio of 17.1% which is higher than that reported in present study. so, in general the results of the current study is matching with what was reported by most of studies researching the impaction of maxillary canine especially the dominance of females and also the left side dominance. although, there is some difference in ratios in comparison to the ratios reported in different studies which could be related to several factors; one of the these factors is the racial difference among samples included in these studies, the other factor is the difference in the size of the sample which could to some extent affect results and also variable methodology and difference in age range could result in this variance in prevalence ratios. as a conclusion; the prevalence of impacted maxillary canine in people attending the college of dentistry, university of al-basrah is 2.7%. canine impaction is a common dental disruption; early diagnosis of potential impaction of maxillary canine could reduce the time and expense needed for predictable future orthodontic treatment. references 1. gunduz k, acikgoz a, egrioglu e. radiographic investigation of prevalence associated pathologies and dental anomalies of the no-third molar impacted teeth in turkish oral patient. chinese j dental res 2011; 14(2): 141-6. 2. sridharan k, srinivasa h, madhukar s, sandbhor s. prevalence of impacted maxillary canines in patients attending outpatient department of sri siddhartha dental college and hospital of sri siddhartha university, tumkur, karnataka. j dent sci res 2010; 1:109-17. 3. thilander b, jakobsson so. local factors in impaction of maxillary canines. acta odontol scand 1968; 26:145-68. 4. bedoya mm, park jh. a review of the diagnosis and management of impacted maxillary canines. j am dent assoc 2009; 140: 1485-93. 5. mesotten k, naert i, van steen berghe d, willems g. bilaterally impacted maxillary canines and multiple missing teeth: a challenging adult case. orthod craniofac res 2005; 8(1): 29-40. 6. cooke j, wang hl. canine impactions: incidence and management. int j periodontics restorative dent 2006; 26:483-91. 7. becker a, peck s, peck l, kataja m. palatal canine displacement: guidance theory or an anomaly of genetic origin? angle orthod 1995; 65: 95-102. 8. jacoby h. the etiology of maxillary canine impactions. am j orthod 1983; 84:125-32 9. rajendran r, sivapathasundharam b. shafer's textbook of oral pathology. 6th ed. st. louis: elsevier; 2009. 10. vasconcellos rj, oliveira dm, melo-luz ac, gonçalves rb. ocorrência de dentes impactados. rev cirur traumat buco-maxilo-facial 2003; 3: 43-7. 11. de oliviera dl, zorzetto dl, marzola c, toledofilho jl, barbosa jl, haagsma ib. impacted canine prevalence in curbita city-pr. revista ato 2008; 8: 94-108. 12. sajnani ak, king nm. prevalence and characteristics of impacted maxillary canines in southern chinese children and adolescents. j investig clin dent 2014; 5(1): 38-44. 13. ericson s, kurol j. resorption of maxillary lateral incisors caused by ectopic eruption of the canines. am j orthod dentofacial orthop 1988; 94:503-13 14. patil s, maheshwari s, santosh bs, khandelwal s. prevalence of impacted canines in population of western part of india. universal res j dentistry 2014; 4(3):148-52. 15. altaee zh. incidence of impacted maxillary canine and associated with maxillary lateral incisor anomalies in ramadi city. asian j sci and technol 2014; 5(3): 226-9. 16. topkara a, sari z. impacted teeth in a turkish orthodontic patient population: prevalence, distribution and relationship with dental arch characteristics. eur j paediatric dentistry 2012; 13: 311-6. 17. kifyatullah j, bangash th, ayub a, khan db. prevalence and patterns of impacted maxillary canine in a pishawar. pakistan oral dental j 2015; 35(1): 57-60. 18. fardi a, kondylidou-sidira a, bachour z, parisis n, tsirlis a. incidence of impacted and supernumerary teeth–a radiographic study in a north greek population. med oral patol oral cir bucal 2011; 16(1): e56-61. zainab 1.doc j bagh college dentistry vol. 28(1), march 2016 in vitro evaluation pedodontics, orthodontics and preventive dentistry 158 in vitro evaluation of shear bond strength of sapphire brackets after dental bleaching zainab m. kadhom, b.d.s., m.sc. (1) abstract background: the present study was conducted to evaluate the effects of different bleaching methods on the shear bond strength of orthodontic sapphire brackets bonded to human premolars teeth using light cured composite resin and to determine the predominant site of bond failure. materials and methods: thirty freshly extracted human premolars were selected and randomly divided into three groups (10 per group). these groups are: control (unbleached) group, hydrogen peroxide group (hp) 37.5% ; which is the inoffice bleaching method group, carbamide peroxide group (cp) 16%; which is the athome bleaching method group. after bleaching process was performed, all the teeth stored in distilled water in a sealed container at room temperature for 24 hours before bonding was initiated, then orthodontic brackets were bonded with a light cure composite resin, stored in distilled water at room temperature for another 24 hours before debonding then the brackets de-bonded and tested for shear bond strength using an instron universal testing machine. for adhesive remnant index (ari) the enamel surface and bracket base of each tooth were inspected under magnifying lens (20x) of a stereomicroscope. results and conclusions: non-statistically significant differences of shear bond strengths were found between the control group and the bleached groups, the dental bleaching in both methods did not affect the sbs of sapphire brackets. the mode of failure was mostly between the adhesive and the enamel and the bond failure between the bracket base and the adhesive were also observed. keywords: shear bond strength, tooth bleaching agents, orthodontic brackets, dental bonding. (j bagh coll dentistry 2016; 28(1):158-163). introduction discoloration of teeth is one of the biggest esthetic concerns of dental patients (1). with an increasing demand for adult orthodontics, orthodontists often encounter patients who are unsatisfied not only with the alignment but also with the color of their teeth. bleaching with various whitening agents in the office and in the home has now gained worldwide acceptance and has become popular among clinicians and patients as a method for lightening teeth. however, the changes in enamel structure and composition induced by these bleaching agents may decrease the shear bond strength (sbs) of orthodontic brackets (2). bleaching is the simplest, most common, least expensive means for eliminating stains since there is no need to prepare the teeth so that the enamel and dentin structures remain largely untouched(3,4). there are three techniques of bleaching: in-office, at home, and over-thecounter. an in-office use high concentration of carbamide peroxide (35-37%) and hydrogen peroxide (30-35%), while 20% carbamide peroxide and 10% hydrogen peroxide are used for at-home bleaching. an over-the-counter product is available to consumers as strips, wraps, and paints-on containing hydrogen peroxide (5). the main difference between in office and at home products is that the carbamide’s latter product carbopal which improves adhesion and prolongs the oxygen release (6). (1)assistant lecturer. department of orthodontics. college of dentistry. university of baghdad. in-office vital tooth bleaching has been used for many years in dentistry and is known to be a reliable technique for quickly lightening discolored teeth (7,8). today, the most commonly used tooth bleaching agents contain hydrogen peroxide as the active ingredient. hydrogen peroxide acts as a strong oxidizing agent through the formation of reactive oxygen molecules; these reactive molecules attack long chained dark colored chromophore molecules and split them into smaller, less colored and more diffusible molecules. hydrogen peroxide may be applied directly or produced by a chemical reaction from sodium perborate or carbamide peroxide (9). at-home vital tooth bleaching also has been shown to produce a significant perceivable change in color, reducing chair time and, therefore, it has become very popular (10,11). carbamide peroxide also breaks down into urea and hydrogen peroxide in aqueous solution (12). at-home bleaching was first described by haywood and heymann (13) in 1989 as night guard dental bleaching. in its undiluted form, carbamide peroxide has the equivalent concentration of a 35% hydrogen peroxide. it has been proposed that at such concentrations, it can result in chronic inflammation, tooth hypersensitivity, and preneoplastic lesions (14). however, the current at home bleaching systems use carbamide peroxide diluted to a 10% concentration (15). the most dentists prefer to use carbamide peroxide in a 15% concentration (16). j bagh college dentistry vol. 28(1), march 2016 in vitro evaluation pedodontics, orthodontics and preventive dentistry 159 the result of the bleaching procedure depends principally on the concentration of the bleaching agent, the ability to reach the discolored sites, and the degree of peroxide exposure time. extended duration and frequency that the agent is in contact with the organic molecules provide similar bleaching results as highly concentrated, shortterm power bleaching (17). bond strength can be defined as force per unite area required to break a bonded assembly with failure occurring in or near the adhesive/adherened interface, it is commonly reported in units of megapascals (mpa) (18,19). in iraq, only three studies (20-22) evaluated the shear bond strength on bleached teeth. these studies didn’t use home bleaching and ceramic brackets except for one study that evaluate the sbs of sapphire brackets which are bonded to endodontic treated teeth bleached with both of hydrogen peroxide and carbamide peroxide (22); so this in vitro study was carried out to evaluate the effects of different bleaching methods by using (37.5% hydrogen, 16% carbamide peroxide as bleaching agents) on the shear bond strength (sbs) of orthodontic sapphire brackets and to determine the predominant site of bond failure. materials and methods materials teeth thirty freshly extracted human premolars, stored in distilled water to prevent dehydration until bonding, were used in this study. the criteria for teeth selection included intact buccal enamel that had not been subjected to any pretreatment chemical agents, e.g. hydrogen peroxide, with no cracks due to the pressure of the extraction forceps, and no caries. brackets sapphire brackets {perfect sb (clear®)} from hubit co., south korea with base surface area 12.807 mm2 were used in this study. bleaching material 1. pola office: 37.5% hydrogen peroxide from sdi, australia was used pola office. in-office bleaching kit contain: two pola office syringes, 1st syringe is 2.8 ml tooth whitening system which composed from 37.5% hydrogen peroxide 2nd syringe is 1gm gingival barrier syringe for protection of gingiva. 2. pola night: 16% carbamide peroxide gel tooth whitening system from sdi, australia was used pola night. at-home bleaching kit contain: one syringe which composed from 16% carbamide peroxide gel 3 gm equivalent to 5.3% hydrogen peroxide. methods teeth mounting retentive wedge shaped cuts were made along the sides of the roots of each tooth to increase the retention of the teeth inside the self-cured acrylic blocks. each tooth was fixed on a glass slide in a vertical position using soft sticky wax at the root apex, so that the middle third of the buccal surface was oriented to be parallel to the analyzing rod of the surveyor. this kept the buccal surface of tooth parallel to the applied force during the shear test(23). then the two l-shaped metal plates, were painted with a thin layer of separating medium (vaseline) and placed opposite to each other in such way to form a box around the vertically positioned tooth with the crowns protruding. after that, the powder and liquid of the self cured acrylic were mixed and poured around the tooth to the level of the cemento-enamel junction of each tooth (24). after setting of the self-cured acrylic resin, the two l-shaped metal plates were removed, the sticky wax used for fixation of tooth in the proper orientation removed too and the resulting holes filled with self cure acrylic. slight adjustment of the acrylic blocks was done using the portable engine to adjust the acrylic block to make it fit properly in the testing machine. after mounting, the specimens were color coded (25), and stored in distilled water (26) to prevent dehydration until bonding. the selected thirty teeth were randomly divided into three main groups each group containing ten teeth, these groups are: control (un bleached) group, hydrogen peroxide group (hp) 37.5%; which is the in-office bleaching method group, carbamide peroxide group (cp) 16%; which is the athome bleaching method group. bleaching procedure the buccal surface of each tooth clean with a non-fluoridated pumice/water slurry in a rubber cup attached to a slow-speed hand piece for 5 seconds (for standardization one rubber cap for each groups) washed for 10 seconds and dried for 10 second using an air water syringe (26). for in-office bleaching according to the manufacture's instructions as follow: firmly attach a mixing nozzle to the pola office syringe then dispense a small amount of gel on to mixing pad until a uniform gel is extruded, by using the nozzle as a guide, directly apply a thin layer of gel to the buccal surface of teeth by using brush j bagh college dentistry vol. 28(1), march 2016 in vitro evaluation pedodontics, orthodontics and preventive dentistry 160 applicator. leave gel on buccal surface for 8 minutes, then the teeth were cleaned with gauze(26). then repeated this step three times so the total application time is 24 minutes. after that the gel was washed thoroughly from the tooth surface using air water syringe for one minute then the surface was dried with compressed air for 30 seconds(27). then the teeth were store in distilled water fore 24 hours at room temperature , then the teeth pumiced then bonded then store in distilled water fore 24 hours then debonding(26). for at-home bleaching: according to the manufacture's instructions a layer of the bleaching agent (16% carbamide peroxide) gel was applied by pola night syringe to the buccal surface of teeth of one application per day at 6 hours for 5 consecutive days. all bleaching procedures were conducted in a humid atmosphere at 37ºc, after each bleaching, the samples were washed under tap water for 30 seconds (28). on completion of bleaching, all the specimens stored in distilled water in a sealed container at room temperature fore 24 hours before bonding was initiated. the control groups were not bleached and were stored under identical conditions as the experimental groups for 24 hours (26,28). bonding the teeth were cleansed and then polished with pumice slurry and rubber prophylactic cups for 10 seconds then thoroughly washed and dried(29). the bonding with composite (according to the manufacturer’s instructions): 37% phosphoric acid gel was applied for 30 seconds, washed with air water spray for 20 seconds and then dried with oil/ moisture-free air until the buccal surface of the etched tooth appeared chalky white in color. thin uniform coat of resilience® sealant (ortho technology co., usa) were applied by brush on each tooth surface to be bonded. small increment of resilience® adhesive paste (ortho technology co., usa) then applied onto the bracket back using flat ended instrument. a load of about 300g was attached to the vertical arm of the surveyor to standardize the pressure applied on the brackets during bonding to ensure seating under an equal force and to ensure a uniform thickness of the adhesive and prevent air entrapment which may affect bond strength (30). the excess then removed from around the bracket with dental probe. each bracket was then light cured for 20 seconds (ten seconds on mesial and another ten seconds on the distal side) (31) using the “led” light cure unit (radii-cal light emitting diodes “led” with wave length range 420 – 480 nm) (woodpecher, china). every tooth was left undisturbed for 30 minutes to ensure complete polymerization of adhesive material (32), then stored in distilled water in a sealed container at room temperature fore 24 hours (26). de-bonding and examination of adhesives remnants the samples were tested for shear bond strength using an instron universal testing machine. a crosshead speed of 0.5mm/minute was used. readings were recorded in newton. the force was divided by the surface area of the bracket base to obtain the stress value in mega pascal units. to estimate the adhesive remnant index, the de-bonded brackets and the enamel surface of each tooth were inspected under a stereomicroscope (magnification 20x) to determine the predominant site of bond failure. the site of bond failure was scored according to wang et al. classification (33) and as followed: score i: the site of bond failure was between the bracket base and the adhesive. score ii: cohesive failure within the adhesive itself, with some of the adhesive remained on the tooth surface and some remained on the bracket base. score iii: the site of bond failure was between the adhesive and the enamel. score iv: enamel detachment. statistical analysis data were collected and analyzed using spss (statistical package of social science) software version 15 for windows xp chicago, usa. in this study the following statistics were used: 1. descriptive statistics: including means, standard deviations, frequencies, percentages and statistical tables. 2. inferential statistics: including: a) independent sample t-test: to test any statistically significant difference of the shear bond strengths between the control group and experimental groups. b) chi-square: to test any statistically significant differences among the groups for the adhesive remnant index. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant j bagh college dentistry vol. 28(1), march 2016 in vitro evaluation pedodontics, orthodontics and preventive dentistry 161 results and discussion esthetics of the teeth including colors are of great importance to patients. orthodontists often face patients who are dissatisfied not only with the appearance, but also with the color, of their teeth. a number of methods and approaches have been described for bleaching teeth. these methods have various bleaching agents, concentrations, times of application, product format, application mode, and light activation. (34). a balance in bond strength must be achieved when choosing a bracket-adhesive combination for fixed orthodontic treatment. bond strength should not only be high enough to resist the forces during the course of orthodontic treatment but also low enough to allow the removal of the bracket without any complications at the end of orthodontic treatment. therefore, high mean bond strength does not necessarily mean better clinical performance (35). ceramic polycrystalline brackets based on mesh are more common and popular than monocrystalline brackets. they present similar modes of failure and bond strength; however, monocrystalline brackets are stiffer and therefore have a higher risk of fracture during removal (36). the findings of this study can not be thoroughly compared with other studies due to different bleaching material types and concentration, brackets type, bleaching technique, storage time and media and different adhesives used. although the sbs was higher that suggested by reynolds (37) in all three groups in the present study (table 1) but there is no significant difference between control group and in-office bleached group (p>0.05) and between control group and athome bleached group (p>0.05). this could be explained by the presence of zirconia particles coating the bracket base of the sapphire brackets which creates millions of undercuts that secure the bracket in place by micro mechanical retention means. the translucency of the sapphire brackets gives a better chance for complete polymerization of the adhesive with light curing, and sapphire brackets are single-crystalline brackets so they are hard and offer great strength that prevents or reduces the peeling effects that may occur during brackets debonding thus give them high sbs values. although the mean value of sbs of this study is less than that of abdulkareem and al-mulla (22) but both showed non-significant difference between the three groups. on the other hand, oztas et al., (38) found statistically non-significant differences between the shear bond strengths of metal and ceramic brackets bonded to bleached enamel after 24 hours, 14 days and unbleached enamel with light or chemical cure adhesives. immerz et al., (39) showed there was no significant difference noted in bonding strength between nontreated surfaces and those treated with peroxide. while in firoozmand et al., (40) there was a significant difference between bleached and unbleached enamel after 14 days of storage in saliva, and this is disagree with this study the site of failure provides useful information about the bonding process. ideally, in orthodontics, an adequate bond that fails at the enamel-cement interface is desirable because debonding and subsequent polishing procedures would become much easier (41). reviewing table 2, the results showed that the predominant scores were score i and score iii with 20% score iv and so the results of ari score comparisons indicated a highly significant difference in failure site between bleached and control groups; this come in agreement with others (39,40). immerz et al., (39) found that the predominant score was i (all of the resin remains on the enamel surface after debonding), while in firoozmand et al. study (40) was score iii which mean score i in present study is in non-bleached group presented in a higher percentage of enamel-resin adhesion compared to the bleached group, so there is a significant associations between the distribution of ari scores and the bleaching treatment. oztas et al., (38).failure was mostly at the bracket/adhesive interface and cohesive failures within the resin, and this agrees in (bracket/ adhesive interface failure) but disagrees in (cohesive failures within the resin) with the present study. as conclusion: 1. the vital bleaching in both methods (at-home bleaching method and in-office bleaching method) did not effect on sbs of the sapphire brackets in this study. 2. the mode of failure was mostly between the adhesive and the enamel and the bond failure between the bracket base and the adhesive were also observed. j bagh college dentistry vol. 28(1), march 2016 in vitro evaluation pedodontics, orthodontics and preventive dentistry 162 table 1. descriptive statistics and group's differences of the shear bond strength (mpa) groups descriptive statistics groups' difference mean s.d. t-test p-value control 18.15 3.53 1.367 0.209 (ns) at-home bleaching 15.38 2.84 control 18.15 3.53 1.143 0.286 (ns) in-office bleaching 16.12 1.82 table 2. distribution and percentage of adhesive remnant index groups scores comparison i ii iii iv x2 d.f. p-value control 2 (20%) 0 (0%) 8 (80%) 0 (0%) 13.5 4 0.009 (hs) in-office bleaching 8 (80%) 0 (0%) 2 (20%) 0 (0%) at-home bleaching 2 (20%) 0 (0%) 6 (60%) 2 (20%) references 1. hattab fn, qudeimat ma, al-rimawi hs. dental discoloration: an overview. j esthet dent 1999; 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(ivsl). j bagh college dentistry vol. 29(3), september 2017 comparison of among pedodontics, orthodontics and preventive dentistry 86 comparison of shear bond strength of sapphire bracket bonded to zirconium surface after using different surface conditioning methods (in vitro study) hawraa ihsan, b.d.s. (a) dhiaa jaafar al-dabagh, b.d.s, m.sc. (b) abstract background: the present study was carried out to compare shear bond strength of sapphire bracket bonded to zirconium surface after using different methods of surface conditioning and assessment of the adhesive remnant index. materials and methods: the sample composed of 40 zirconium specimens divided into four groups; the first group was the control, the second group was conditioned by sandblast with aluminum oxide particle 50 μm, the third and fourth group was treated by (nd: yag) laser (1064nm)(0.888 watt for 5 seconds) for the 1st laser group and (0.444 watt for 10 seconds) for the 2nd laser group. all samples were coated by z-prime plus primer. a central incisor sapphire bracket was bonded to all samples with light cure adhesive resin. shear bond strength was measured by using tinius olsen universal testing machine. after debonding, each bracket and zirconium surface were examined and adhesive remnant index was registered. the difference in shear bond strength among groups was analyzed by using anova test. the adhesive remnant index was assessed using chi-square test. results: the 2nd laser group had the highest mean value of shear bond strength then the 1st laser group followed by the sandblasting group, while the control group had the least value, non-significant difference in the shear bond strength was found between the laser groups and highly significant difference was found between all other comparable groups. non-significant difference in the site of bond failure was found between the laser groups and sandblasting group, and between the two laser groups. conclusion: the laser conditioning method showed higher value of shear bond strength than the sandblasting conditioning method. keywords: zirconium, zirconium prime plus primer, laser, shear strength.(j bagh coll dentistry 2017; 29(3):86-92) introduction at present, the number of adults seeking orthodontic treatment is increasing. many of them present to orthodontic clinics with restorations such as crowns and bridges in their mouth, made of yttrium-stabilized tetragonal zirconia (y-tzp) ceramics or in short, zirconium crowns. these crowns are widely used and favored for their advantages including biocompatibility, aesthetics, cost effectiveness, fracture resistance, and accurate fabrication. zirconia crowns are used to restore posterior teeth and occasionally anterior teeth when the focus is more on strength rather than aesthetics (1). the approaches suggested improving bond strength to zirconium surfaces can be grouped into three broad categories, namely mechanical, chemical, or combination. the purpose of mechanical alteration of the zirconium surface is to remove the glaze and roughen the surface to provide sufficient mechanical retention for the adhesive, allowing for the successful placement and retention of the orthodontic bracket (2). (a) master student. department of orthodontics, college of dentistry, university of baghdad. (b) professor. department of orthodontics, college of dentistry, university of baghdad. mechanical adhesion alone is not enough for providing the optimal bond strength so; they promote the chemical adhesion in zirconia bonding. however, roughness of the surface is a key factor for adhesion to zirconia and the elimination of these particles abrasion for surface treatment could result in great reduction in bond strength (3,4). chemical bonding to zirconium can be done by adhesive functional monomers, which are supposed to have the capability to form chemical hydrogen bonds with metal oxides at the resin/zirconia interface and improving the wettability (5). phosphate monomers are proven to be effective in bonding to non-silica based polycrystalline materials of zirconia, metal and alumina (6). numerous research studies have shown that phosphate/phosphonate monomers are very effective in improving zirconia bonding (7). z-prime plus is a phosphate monomer and it contains a propriety formula of concentrated methacryl oxydecyl dihydrogen phosphate (mdp) and carboxylic monomers formulated specific to zirconia, alumina, and metal. the versatility of these primers is a compelling feature for use on many different indirect substrates (8). there was no any known previous study that conducted to compare between shear bond strength using laser and sandblasting method of sapphire bracket bonded on zirconium surface, so j bagh college dentistry vol. 29(3), september 2017 comparison of among pedodontics, orthodontics and preventive dentistry 87 it is intended to implement this current study to provide baseline data regarding this important subject. materials and methods sample two blocks of zirconium was cut by one dental technician in order to obtain forty cylindrical specimens with a diameter of 8mm and a height of 6mm. the samples were cured in a special oven according to manufacture instruction, after that the samples were painted with glaze layer and fired at 940ºc for 15 minutes. each surface had been examined by using a 10x magnifying eye lens to see if there is any manufacture defect including cracks, roughness or irregularities on the labial surface of the veneer (9). construction of the acrylic blocks silicone mold with a cubic hole (15mm) in dimensions and a circular hole in the bottom of the cube (8mm) in diameter was used so that the glazed surface of the specimen was inserted inside the hole in order that no acrylic material had came in contact with the surface. each zirconium specimen was placed in the acrylic mold, after that the acrylic was mixed according to manufacture instructions and poured into each mold, then the acrylic block with the zirconium specimen was taken out of the mold. sample grouping the specimens would be divided according to the surface conditioning into four groups: 1group (a) control group (with blue acrylic block) 2group (b) sandblasting group (with brown acrylic block) 3group (c) and (d) laser groups (with pink and green acrylic blocks respectively) all samples were ultrasonically cleaned with distilled water for 6 minutes (10) to remove the factors that inhibit adhesion and dried naturally in the atmosphere. surface conditioning a-sandblasting group by using twin-pen sandblaster machine, the zirconium surfaces would be sandblasted by 50μm aluminum oxide powder for 5 sec. at 10mm distance with 2.5 bars (11). for standardization, a ruler was fixed at the tip of the sanblaster pen). b-laser groups a drill stand had been used so that the hand piece of nd:yag laser device was placed on the upper part of the stand and the zirconium samples were placed on a cube table on the base of the stand. the laser groups were treated with nd:yag laser (1064 nm). energy density of 141.54 j/cm2 was delivered through laser handpiece and kept 1mm from the specimen (12). according to the calculation, the energy density was set at 4.44j for both groups. the spot size for the laser device is 2mm in diameter so the radius is 1mm which equivalent to 0.1 cm the surface area = (0.1)2×3.14 = 0.0314 cm the energy density = energy/ area 141.54j/cm2= energy / 0.0314 cm2 e=4.44j the output energy of the laser device for the first group was 888mj for an irradiation time of 5 seconds result in an accumulated energy of 4.44j power=energy/time power=4.44j/5 second= 0.888 watt. the output energy of the laser device for the second group was 444mj for an irradiation time of 10 seconds result in an accumulated energy of 4.44j power=4.44j/10 second = 0.444 watt the time was selected according to a pilot study by fabricating a zirconium disks (1mm) in thickness because the optimal labial and lingual reduction will range from 1.0-1.5 mm for teeth preparation of the crown of the anterior teeth (13,14). the disk was putted on around table and the end of thermo couple device was in direct contact with the disk, when the output setting of (444mj) was applied on the disk, the thermo couple readings recorded 1.2 degree temperature elevation after 5 seconds and 3.3 degree temperature elevation after 10 seconds. when the out put of (888mj) was applied on the disk, the thermo couple device readings recorded 3.7 temperature elevations after 5 seconds. (5.5) temperature elevation considered as a critical temperature elevation for the pulp (15). for this reason (5-10) seconds were selected as a safety exposure time for the two laser groups. bonding procedures the bonding was done by applying a thin layer of primer on the outer surface of zirconium sample and on the mesh of the brackets by using a disposable brush (as standardization one rubber cup used for each specimen with single stroke in gingival incisal direction) and wait for 10 seconds according to the manufacture instruction, and then an equal amount of light cure composite would be applied on the bracket base according to the manufacturer instructions, which would then position in the center of the circle surface of the zirconium specimen using a bracket holder. j bagh college dentistry vol. 29(3), september 2017 comparison of among pedodontics, orthodontics and preventive dentistry 88 then, a constant load would be applied by vertical arm of the surveyor by weight fixation of 200gm. on the top of this arm, which would be placed on the bracket at 90° for 10sec., to ensure that each bracket would seat under equal force (9,16). any excess bonding material was carefully removed from around the bracket base with a sharp hand scaler without disturbing the seated bracket (17-19) then, the brackets cured for 40sec. (20sec. on the mesial and 20sec. on the distal of the brackets) (20) at a distance of 5mm (21) (for standardization, a ruler was fixed at the tip of the light probe) and an angle of 45º to the proximal surface of the bracket (22). after the completion of the bonding procedure, the specimens would be allowed to bench cure for 30 minutes, then would be immersed in deionized distilled water and could be stored in the incubator at 37ºc for 24 hours to stimulate the oral condition (23). shear bond strength test shear test was accomplished using tinius olsen universal testing machine, with loading cell 50 kilogram and a crosshead speed of 0.5mm/min (19,24). each sample was seated in the mounting metal vice and placed on the base of the testing machine. the chisel end rod was fitted inside the upper arm of the testing machine with its chisel end downward parallel to the zirconium outer surface to apply a force in an gingivo-incisal direction of the bracket that produce a shear force at the bracket base/zirconium surface interface, until debonding occurs. when the bracket was debonded from the zirconium surface by the force applied from the testing machine, the ultimate magnitude of the reading was taken; this force was measured in kilograms and converted into newton according to the following equation: force (n) =load (kg) x ground acceleration (9.8m/sec.). then, the force was divided by bracket base surface area to get the strength value in mega pascal (mpa) units. each debonded bracket was kept with its corresponding zirconium veneer to estimate the adhesive remnant index. estimation of the adhesive remnant index the debonded bracket and zirconium surface of each tooth were inspected using a 10x magnifying lens to determine the predominant site of bond failure (18,25). the site of bond failure is scored as follow (26): score i: between the bracket base and adhesive. score ii: cohesive failure within the adhesive itself, with some of the adhesive remained on the zirconium surface and some remained on the bracket base. score iii: between adhesive and zirconium surface. score iv: zirconium detachment statistical analyses data were collected and analyzed using spss (statistical package of social science) software version 15 for windows xp chicago, usa. in this study the following statistics were used: 1. descriptive statistics: including mean, standard deviation, minimum, maximum, percentage, frequency and statistical tables. 2. inferential statistics: including: a. one way analysis of variance (anova): to test any statistically significant difference among the tested groups. b. the tukey hsd test was performed to compare the difference between each two tested groups when anova showed a statistical significant difference. c. chi-square: to test the non-parametric data for adhesive remnant index. p level was set at the following levels: p> 0.05 ns non significant 0.05 > p > 0.01 s significant p< 0.01 hs highly significant results the descriptive statistics (means, standard deviations, minimum and maximum values) of the shear bond strength of each group were presented in table (1). the shear bond strength values of all tested samples were expressed in mega pascal (mpa). regarding the methods of surface conditioning, the 2nd laser group had the highest mean value of shear bond strength (30.67±2.33mpa) of all groups followed by 1st laser group (30.25±2.31mpa) followed by the sandblasting group (22.29 ± 1.18mpa) while the control group had the least value (11.08±1.96mpa). one way analysis of variance (anova) showed that, there was statistically highly significant difference (p≤0.01) among the mean values of the shear bond strength of all tested groups the tukey hsd test was performed to compare the difference between each two tested groups (table 2). it showed the followings: ahighly significant difference (p≤0.01) between control and all other comparable groups. bhighly significant difference (p≤0.01) between sandblasting and all other comparable groups. j bagh college dentistry vol. 29(3), september 2017 comparison of among pedodontics, orthodontics and preventive dentistry 89 chighly significant difference (p≤0.01) between 1st and 2nd laser group respectively with control and sandblasting group. dnon-significant difference (p-value>0.05) was found between 1st and 2nd laser groups table 1: descriptive statistics of the shear bond strength (mpa) groups n mean s.d. min. max. control 10 11.08 1.96 8.75 14.58 sandblasting 10 22.29 1.18 20.41 23.75 1st laser 10 30.25 2.31 27.08 34.58 2nd laser 10 30.67 2.33 27.5 35 table 2: comparing the shear bond strength between each two groups using tukey hsd test groups mean difference p-value control sandblasting -11.21 0.000 (hs) 1st laser -19.17 0.000 (hs) 2nd laser -19.59 0.000 (hs) sand blasting 1st laser -7.96 0.000 (hs) 2nd laser -8.38 0.000 (hs) 1st laser 2nd laser -0.42 0.966 (ns) adhesive remnant index “ari” the sites of bond failure of all tested groups were shown in table (3). the highest percentage of bond failure was seen at zirconium-surface interface (score iii) in control group while the cohesive failure (score ii) was seen in laser groups in high percentage (90%) with only (10%) score iii. in sandblasting group (score iii) was seen in low percentage (20%) while (score ii) was seen in high percentage (80%) in this group. regarding (score i) and (score iv) there were no any value registered among all three groups. statistically, chi-square test showed highly significant difference in the site of bond failure among all tested groups. yate's correction test was used to compare the site of bond failure between each two groups and showed highly significant difference between the control group and the other groups while there was no significant difference among the groups other than control. discussion the effects of four surface preparation methods on the sbs values of sapphire brackets to zirconia surfaces were compared. the results of this study revealed that laser conditioning groups specimens table 3: frequency distribution of the ari scores in different groups groups scores i ii iii iv total control n 0 0 10 0 10 % 0 0 100 0 100 sandblasting n 0 8 2 0 10 % 0 80 20 0 100 1st laser n 0 9 1 0 10 % 0 90 10 0 100 2nd laser n 0 9 1 0 10 % 0 90 10 0 100 total n 0 26 14 0 40 % 0 65 35 0 100 possessed the highest sbs followed by sandblasting group, while the control group possessed the least sbs. comparison between air abrasion and laser as a conditioning method to zirconium surface pointed out several advantages and disadvantages as following: regarding the advantages of both mentioned methods, it is well known that both of them lead to surface roughness which increases the surface area, improves the wettability by diminishing the surface tension, and produces micromechanical retention. however, the present study found that laser conditioning increases sbs more than sandblasting. while regarding the disadvantages of both methods, the following were found: in air abrasion method, sandblasting and mechanical abrasion are capable to create micro cracks in zirconia to supply retention; even though these methods also weakens the mechanical properties of zirconia (27,28), this was overcome in the current study by reducing the pressure during air abrasion and using particles up to 50 μm in size coincided with piascik (29). while in laser conditioning method, it was found that heat generation by laser irradiation may cause: 1wide-melting areas and big cracks lead to defects and decrease the mechanical properties of zirconia ceramics especially if the used power setting ranged from 3-4 watt (12). 2critical temperature elevation for the pulp. these two mentioned disadvantages were overcome in current study by using power setting (0.888, 0.444) watt. it is important to mention that power setting of laser irradiation is affected by time and energy according to the equation: power=energy/time. we select the exposure time according to a pilot study to get precise power with least harmful effect on zirconium surface and consequently the j bagh college dentistry vol. 29(3), september 2017 comparison of among pedodontics, orthodontics and preventive dentistry 90 tooth health and (5,10) seconds were selected according to this study as a safety exposure time for the two laser groups. in the current study nd:yag laser with different parameters as irradiation time (in seconds) and power (in watt) was used to study the influence of the variation on zirconium surface because various laser parameters are known to influence ceramic materials differently (30). from clinical point of view changing the irradiation time and the power can be represented by following diagram: the variation in the manner of radiation logically affected both the chair time and the risk of laser on tooth health and structure, and there is a difference in the thermal relaxation time. however, statistically no significant difference was found between the two manners and this may be due to the same total accumulated energy in the two groups. failure site regarding the occurrence of ari score (ii) which indicated cohesive failure within the adhesive itself, it was the predominant one and represented 65% (26 specimens) of all tested samples, and the highest percentage happened both in the laser groups, it was (90%), and it was (80%) in the sandblasting group, while there was no occurrence of ari score (ii) in control group. regarding the occurrence of score (iii) which indicate failure at adhesive zirconium interface, it represented 35% of all tested samples, more specifically (100%) (10 specimens) in control group, and it was in a low percentage (10%) and (20%) in laser groups and sandblasting group respectively and this could be negligible. control group the occurrence of ari score (iii) represented (100%) in this group and this might be due to: 1the bond failure occurs generally at the area of least resistance that means that the bond strength between the adhesive–bracket interface and the cohesive bond strength of the adhesive itself were stronger than the bond strength between the adhesive and zirconium. this might be attributed to the hardness glossy surface of zirconia, so the mechanical retention might not be adequate enough. 2-adhesive failure at the zirconium surface might be the result of reduced depth of adhesive penetration since the resin tags were thin, and less uniform, which was conductive to weaker bond, hence less adhesive would stay on the tooth at the time of de-bonding, in addition, bracket failure typically occurs at the weakest link in the adhesive junction and the weakest link appeared to be at the surface/adhesive interface, agreed with the finding of (31,32). sandblasting group and laser groups the occurrence of ari score (ii) were the predominant in these groups and represented (80%) and (90%) in sandblasting and laser groups respectively and this might be due to: 1the bond failure happened usually at the area of least resistance which means that the bond strength between the adhesive and zirconium were stronger than the bond strength between the adhesive–bracket interface and the cohesive bond strength of the adhesive itself. this might be attributed to occurrence of sufficient mechanical retention by air abrasion and laser. 2aluminum oxide (al2o3) sandblasting has the potential for enhancing surface energy, surface area, and wettability for the proper adhesive procedure (33). however this result disagreed with obradović-djuričić (34) who stated that air abrasion of zirconia, with alumina or other particles produces surface scratching that might be not adequate enough to produce optimal mechanical retention between the adhesive and zirconium surface. 3the increased bond strength observed in the laser-treated group is related to micromechanical retention that gained by laser conditioning (35), the laser irradiation on zirconia bonding surface considerably increase shear bond strength because of surface roughness (36). smith (37) stated that surface-adhesive interface failure score (iii) is desirable, since the problem of residual adhesive is not encountered, while saraç and harari (11,38) stated that, cohesive failure within the adhesive itself (score ii) is preferable to avoid surface damage throughout debodning which clinically leading to the long-term integrity of the restorations, however this type of residual adhesive may need further treatment to remove it from the zirconium surface, a process that might cause additional damage to zirconium restoration surface and this coincided with the finding of (39). none of the tested samples showed score (1) that indicates that usually failure happened between brackets and adhesive, this might be j bagh college dentistry vol. 29(3), september 2017 comparison of among pedodontics, orthodontics and preventive dentistry 91 owing to high mechanical interlock provided with every bracket base without any weak point between bracket adhesive links, the sapphire bonding base is coated with powder of zirconium that produce millions of undercuts which mechanically lock with the bracket adhesive (40). also none of the tested samples showed score (iv) which usually indicates surface detachment, this may attributed to exceptional strength of the zirconia surface which might reach to (1000mpa) in addition to that, the values of the shear bond strength were within (8.7535 mpa). a direct relation between bond strength and ari scores was found in the current study, suggesting that greater bond strength was associated with lower ari scores. knox and wang (41,42) reported that there is no relation between the value of the sbs and the site of bond failure and this seems to be because of different types of bonding materials used, different types of brackets base designs; or due to different testing methods applied, while coupssmith and klocke (31,43) stated that, there is a relation between the sbs value and ari and when the value of the sbs increase the site of failure will move toward the surface of the tooth. the conclusions that could be drawn from this study were: 1. zirconium surface conditioning with air abrasion and laser provides good value of shear bond strength for sapphire brackets; however irradiation with the laser was better than air abrasion. 2. no significant statistical difference was found regarding the values of shear bond strength when two different ways for laser application (high power for a short time and low power for a long time) were used. 3. the occurrence of ari score (ii) which indicate cohesive failure within the adhesive itself were the predominant mode of bond failure in surface conditioning groups which is considered as the most preferable to avoid surface damage during debonding which clinically leading to the long-term integrity of the restorations, and none of the samples showed detachment between the bracket base 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roughness of feldspar ceramic. angle orthod 2006; 77: 723-8. 12. liu l, liu s, song x, zhu q, zhang w. effect of nd: yag laser irradiation on surface properties and bond strength of zirconia ceramics. lasers med sci 2015; 30: 627-34. 13. piconi c, maccauro g. zirconia as a ceramic biomaterial. biomaterials 1999; 20:1-25. 14. cramer von clausburch s. zirkon and zirkonium. dent lab 2003; 51:1137-42. 15. zach l, cohen g. pulp response to externally applied heat. oral surg oral med oral pathol 1965; 19:515-30. 16. ajlouni r, bishara se, oonsombatc c, solim m, laffoone j. the effect of porcelain surface conditioning on bonding orthodontic brackets. angle orthod 2005; 75(5): 858-64. 17. bishara se, vonwald l, laffoon jf, warren jj. the effect of repeated bonding on the shear bond strength of a composite resin orthodontic adhesive. angle orthod 2000; 70: 435-41. 18. bishara se, soliman mm, oonsombat c, laffoon jf, ajlouni r. the effect of variation in mesh-base design on the shear bond strength of orthodontics brackets. angle orthod 2004; 74(3): 400-4. 19. millet dt, letters s, roger e, cummings a, love j. bonded molar tubesan in vitro evaluation. angle orthod 2001; 71(5): 380-5. 20. oesterle lj, messer smith ml, devine sm, ness cf. light and setting times of visible light-cured orthodontic adhesives. j clin orthod 2001; 29: 31-6. 21. malkoc s, uysal t, usumez s, isman e, baysale a. in-vitro assessment of temperature rise in the pulp during orthodontic bonding. am j orthod dentofacial orthop 2010; 137(3): 379-5. j bagh college dentistry vol. 29(3), september 2017 comparison of among pedodontics, orthodontics and preventive dentistry 92 22. paschos e, westphal jo, ilie n, huth kc, hickel r, rudki-janson i. artificial saliva contamination effects on bond strength of self-etching primers. angle orthod 2008; 78(4): 716-21. 23. nemeth br, wiltshire wa, lavelle clb. shear/peel bond strength of orthodontic attachments to moist and dry enamel. am j orthod dentofacial orthop 2006; 129: 396-401. 24. sharma-sayal sk, rossouw pe, kufkami gv, titley kc. the influence of orthodontic bracket base design on shear bond strength. am j orthod dentofacial orthop 2003; 124: 74-82. 25. polat o, karaman ai, buyukyilmaz t. in vitro evaluation of shear bond strengths and in vivo analysis of bond survival of indirect-bonding resins. angle orthod 2004; 74: 405-9. 26. wang wn, meng cl, tarng th. bond strength: a comparison between chemical coated and mechanical interlock bases of ceramic and metal brackets. am j orthod dentofacial orthop1997; 111: 374-81. 27. karakoca s, yilmaz h. influence of surface treatments on surface roughness, phase transformation, and biaxial flexural strength of y-tzp ceramics. j biomed mater res bioappl biomater 2009; 91(2): 930-7. 28. yun jy, ha sr, lee jb, kim sh. effect of sandblasting and various metal primers on the shear bond strength of resin cement to y-tzp ceramic. dent mater 2010; 26(7): 650-8. 29. piascik jr, wolter sd, stoner br. development of a novel surface modification for improved bonding to zirconia. dent mater 2011; 27(5): 99-105. 30. gökçe b, ozpinar b, dündar m, cömlekoglu e, sen bh, güngör ma. bond strengths of all-ceramics: acid vs. laser etching. oper dent 2007; 32: 173-8. 31. coups-smith ks, rossouw pe, titley kc. glass ionomer cement, as luting agent for orthodontic brackets. angle orthod 2003; 73: 436-44. 32. al-khatib ar. consequences of employment selfetching primer adhesive in orthodontic practice. alrafidain dent j 2004; 4(2): 95-103. 33. kim bk, bae he, shim js, lee kw. the influence of ceramic surface treatments on the tensile bond strength of composite resin to all-ceramic coping materials. j prosthet 2005; 94: 357–362. 34. obradović-djuričić k, medic v, dodic s, gavrilov d, antonijevic d, zrilic m. dilemmas in zirconia bonding. srparhceloklek 2013; 141(5-6): 395-401. 35. akova t, yoldas o, toroglu ms, uysal h. porcelain surface treatment by laser for bracket-porcelain bonding. am j orthod dentofacial orthop 2005; 128(5): 630– 7. 36. cavalcanti an, foxton rm, watson tf, oliveira mt, giannini m, marchi gm. bond strength of resin cements to a zirconia ceramic with different surface treatments. operative dentistry 2009; 34(3): 280–7. 37. smith ga, mcinnes-ledoux p, ledoux wr, weinberg r. orthodontic bonding to porcelain-bond strength and refinishing. am j orthod dentofacial orthop1988; 94: 245-52. 38. harari d, shapira-davis s, gillis i, roman i, redlich m. tensile bond strength of ceramic brackets bonded to porcelain facets. am j orthod dentofacial orthop 2003; 123: 551-4. 39. trakyalı g, sınmazışık g.a comparative study of shear bond strength ofthree different bracket bases bonded to porcelain surfaces. marmara dent j 2013; 1: 24-28. 40. ortho technology product catalog, 2015. 41. knox j, hubsch p, jones ml, middleton j. the influence of bracket base design on the strength of the bracket-cement interface. j orthod 2000; 27(3): 24954. 42. wang wn, li ch, chou th, wang ddh, lin lh, lin ct. bond strength of various bracket base designs. am j orthod dentofacial orthop 2004; 125: 65-70. 43. klocke a, kahl-nieke b. effect of debonding force direction on orthodontic shear bond strength. am j orthod dentofacial orthop 2006; 129: 261-5. الخالصة عمال طرق مختلفة لتكييف السطح وتقدير نوع الياقوت الملصقة على سطح الزاركون بعد استمن الدراسة الحالية لمقارنة قوة القص للحاصرات التقويمية ءتم اجرا مشعر االلتصاق المتبقي . , والمجموعة الثانية عولجت اربعين نموذج اسطواني من الزاركون وتم تقسيمها الى اربعة مجاميع , المجموعة االولى هي مجموعة التحكمتكونت العينات من ثواني( 5 واط لمدة0.888 نانومتر( )1064) الثة والرابعة عولجت بالليزر من نوع نودميوم ياكمايكروميتر(, والمجموعتين الث 05برمل اوكسيد االلمنيوم ) ( ثم اضيفت حاصرة primer z prime plus) ثواني( لمجموعة الليزر الثانية,ومن ثم طليت كل العينات بمادة 10واط لمدة 0.444 مجموعة الليزر االولى و)ل قوت لكل العينات ولصقت بمادة االرتباط الضوئية التصلب .تقويمية للسن القاطع من نوع اليا ( وتم 10x) مكبرة عدسة باستخدام الزاركون وسطح الحاصرة قاعدة فحصت االرتباط فك وبعد (tinius-olsen)العالمية الفحص الة باستخدام قوةالقص قياس تم .anovaالمجاميع باستعمال تحليل بين رتباطلال الالصقة القوة في الفرق تحليل تم. المتبقي مشعرااللتصاق تسجيل المجموعة المعالجة برمل اوكسيد االلمنيوم ,بينما ا مجموعة الليزر االولى ومن ثم وعة الليزر الثانية اظهرت اعلى قيمة لقوة القص تليهاظهرت النتائج ان مجم بة لقوة القص بين مجموعتي الليزرو وكان هناك فروق ذات داللة عالية بين كل مجموعة السيطرة اظهرت اقل قيمة, لم تكن هناك فروق ذات داللة عالية بالنس بينهم. المجاميع االخرى المقارنة, التوجد اختالفات مؤثرة في موضع الفشل بين مجموعتي الليزر والمجموعة المعالجة وبين مجموعتي الليزر فيما .فضل لقوة القص من طريقة المعالجة برمل اوكسيد االلمنيوممن ذلك نستنتج ان طريقة المعالجة بالليزر اظهرت قيمة ا ayad.doc j bagh college dentistry vol. 28(1), march 2016 an evaluation of restorative dentistry 11 an evaluation of antimicrobial efficacy of steralium, co+steralium, and 5% sodium hypochlorite against enterococcus faecalis biofilm formed on tooth substrate: (an in vitro study) ayad m. al-kadhi, b.d.s., m.sc. (1) abstract background: enterococcus faecalis is emerging as an important endodontic pathogen, which can persist in the environment for extended periods after treatment and may cause endodontic failure. it is known to produce biofilms, a community of bacteria enclosed within a protective polymeric matrix. this study aimed to establish whether the biofilm formation by enterococcus faecalis can be inhibited with steralium, co+steralium, and 5% sodium hypochlorite in the root surface environment. materials and methods: extracted human teeth were biomechanically prepared, vertically sectioned, placed in the tissue culture wells exposing the root canal surface to e. faecalis to form a biofilm. at the end of the 3rd and 6th weeks, all groups were treated for 10 minutes with the previously mentioned tested solutions and control and were analyzed qualitatively and quantitatively. results: qualitative assay with 3-weeks biofilm showed a complete inhibition of bacterial growth with co+steralium and naocl, except steralium and saline, which showed presence of bacterial growth. in quantitative analysis, steralium and salinetreated tooth samples have 57.74 ± 5.39* cfu/ml., 140.71 ± 8.49 cfu/ml. respectively. qualitative assay with 6-week biofilm showed growth when treated with steralium and saline treated tooth samples have 346.0 ± 78.88* cfu/ml., 127.18 ± 17.84 cfu/ml. respectively whereas co+steralium and naocl has shown complete inhibition. conclusions: co+steralium and 5% sodium hypochlorite showed maximum antibacterial activity against e. faecalis biofilm formed on tooth substrate. co+steralium showed statistically significant antibacterial activity. the use of co+steralium as a root canal irrigant might prove to be advantageous considering the several undesirable characteristics of naocl. key words: biofilm, e. faecalis, steralium, co+steralium, naocl, root canal irrigant. (j bagh coll dentistry 2016; 28(1):11-16). introduction enterococcus faecalis is an important pathogen capable of causing root canal infections(1,2), including main canal, lateral, accessories, and dentinal tubules (3,4) may cause endodontic treatment failure (5,6). these organisms, which are ubiquitous within the environment, are generally found in mouth and other parts of git (7-10). enterococcus faecalis can survive for long period and resist many antimicrobials (2,11). the resistance phenotype could be attributed to the ability of an enterococcus faecalis clinical strains to form biofilms on abiotic surfaces11. the innate and emerging resistance of biofilm residing bacteria against antibiotics (12) in the current scenario consequently lead to the screening of various alternative sources to eradicate the bacterial pathogen (1). sterillium® (paul hartmann ag 89522 heidenheim germany) alcohol-based hand disinfection active ingredients in 100 g: propan2-ol 45.0 g, propan-1-ol 30.0 g, mecetroniumetilsulfate (inn) 0.2 g (13). (1)department of conservative dentistry. college of dentistry, university of anbar. bodedex® forte (paul hartmann ag 89522 heidenheim germany) is a modern, powerful instrument cleaner which is exceptionally suitable for cleaning of medicinal heat sensitive and heatresistant instruments as well as laboratory apparatus. bodedex® forte has a neutral ph-value and is therefore particularly gentle to materials(14). naocl was found to be significantly efficient in eliminating e. faecalis biofilms in vitro (15). the main disadvantages of naocl are its unpleasant taste, high toxicity16, and its inability to remove the smear layer (17,18).this study aims to: (i) assess the efficacy of sodium hypochloride, steralium and, bodedex® forte with steralium antimicrobial at removing enterococcus faecalis from dentin surface; and (ii) investigate their effect on the formation of bacterial biofilms. materials and methods a pure culture of e. faecalis (american type culture collection [atcc] 29212) (central health lab., baghdad, iraq) was cultivated on mueller-hinton agar (himedia, mumbai, india), inoculated into mueller-hinton broth (himedia, mumbai, india), incubated at 37ºc overnight and adjusted to an optical density (od1*107) of 1 with sterile mueller-hinton broth. j bagh college dentistry vol. 28(1), march 2016 an evaluation of restorative dentistry 12 the antibacterial activity of sterillium® (paul hartmann ag 89522 heidenheim germany), bodedex® forte (paul hartmann ag 89522 heidenheim germany) +steralium, and 5% sodium hypochlorite (cholorex, amman, jordan) were initially tested on planktonic cells before evaluating them against e. faecalis biofilm formed on tooth substrate. the antibacterial sensitivity test was performed by the disc diffusion method (national committee for clinical laboratory standard, 2000). sterile blank discs (6-mm diameter; himedia, mumbai, india) were impregnated with 10 ml. of test solutions (sterillium®, bodedex® forte +sterillium®, and sodium hypochlorite). the broth culture of e. faecalis was swabbed on sterile mueller-hinton agar plates using sterile swabs. with the help of sterile forceps, the test solutions–incorporated discs were placed on the medium, and the plates were incubated at 37º c overnight. a standard vancomycin disc (30 mg) was included for comparison. the minimum inhibitory concentration (mic) and the minimum bactericidal concentration (mbc) of the test solutions were determined by the tube dilution method. double dilution was made from a higher dilution 100 mg/ml to a lower dilution in a series of test tubes. each tube was inoculated with bacterial suspensions and incubated at 37º c overnight. the mic was regarded as the lowest concentration in the series of dilutions at which there was no visible growth of microorganisms. the subcultures were made from the tubes, which did not yield any visible turbidity (growth) in the mic assay on freshly prepared mueller-hinton agar plates. after 24 hours of incubation at 37º c, the mbc was regarded as the lowest concentration of the test solution that allowed less than 0.1% of the original inoculum to grow on the surface of the medium. in each experiment, test solutions were tested in triplicate. biofilm formation on tooth substrate sixty single-rooted human mandibular premolars with fully formed apices were used in this study. the teeth were cleaned of superficial debris, calculus, and tissue tags and stored in normal saline to prevent dehydration before use. each tooth was radiographed to confirm the presence of a single patent canal. the tooth specimens were sectioned below the cementoenamel junction with a diamond disc to obtain a standardized tooth length of 8 mm for uniform specimen. the root canals were then instrumented using the crown-down technique and hand instruments (protaper, dentsply maillefer, ballaigues, switzerland). the canals were enlarged to an apical size f3. two milliliters of 3% naocl was used between each instrument during the cleaning and shaping procedure. all the teeth were then vertically sectioned along the midsagittal plane into two halves. the concave tooth surface was minimally grounded by new diamond bur for each half to achieve a flat surface to enable placement in the tissue culture wells, exposing the root canal surface to e. faecalis to form a biofilm. the sectioned samples were then divided into five experimental groups. each group consisted of 30 samples each and assigned as group 1 (saline), group 2 (sterillium®), group 3 (bodedex® forte +steralium), and group 4 (5% sodium hypochlorite). then, the samples were placed in the wells of tissue culture plates (zellkultur test plates 24, techno plastic products ag, trasadingen, switzerland) and sterilized by autoclave (gemmy high pressure steam autoclave model tc-615). the bacterium was cultured as described previously, and the wells containing tooth samples were inoculated with 2 ml. of bacterial solution and incubated at 37oc. the culture medium (mueller-hinton broth) was replaced every alternate day to avoid nutrient depletion and accumulation of toxic end products. the samples were taken from each well with a sterile paper point, inoculated onto muellerhinton agar plates, and incubated at 37º c for 24 hours aerobically to check for cell viability and purity of culture. at the end of the third week, all groups were treated for 10 minutes as follows: group 1, immersed in 3 ml. of sterile saline; group 2, immersed in 3 ml. of sterillium®; group 3, immersed in 3 ml. of bodedex® forte +steralium; and group 4: immersed in 3 ml. 5% naocl. then, the biofilm on the root canal portion was scraped and inoculated on mueller-hinton agar plates and incubated for 24 hours at 37ºc for qualitative analysis where n = 5 for each group. the quantitative analysis was performed by vortexing the tooth samples with sterile saline for a few minutes followed by serial dilution method for all the groups where n = 10 for each group. the same procedure was repeated for all groups once again at the end of the sixth week to analyze qualitatively and quantitatively. statistical analysis statistical analysis was performed by using one-way analysis of variance and compared by j bagh college dentistry vol. 28(1), march 2016 an evaluation of restorative dentistry 13 the student t test using spss software (student version 7.01; spss inc, chicago, il). the criterion for statistical significance was defined as p < 0.05. results table 1 shows the zone of inhibition, mic, and mbc of test solutions for e. faecalis (atcc 29212). 5 % naocl test solutions showed a significant zone of inhibition in the disc diffusion assay when compared with vancomycin and co+steralium (p < 0.05). maximum inhibition was observed by 5% naocl followed by steralium compared with co+steralium and vancomycin. no statistical difference was observed between naocl and steralium table 1: susceptibility of e. faecalis atcc 29212 against the test solutions test solution zone of inhibition minimal inhibitory concentration minimal bactericidal concentration steralium 24 mm 1.0 mg/ml. 2.0 mg/ml. co+steralium 17mm* 2.0 mg/ml. 3.0 mg/ml. 5 % naocl 30 mm 0.50% 1.0% vancomycin 17 mm* 2 mg/ml. 3 mg/ml. *p< 0.05 with respect to naoh the qualitative assay with the 3-week biofilm on the canal portion showed complete inhibition of bacterial growth when treated with co+steralium and naocl, but the samples treated with steralium and saline showed the presence of bacterial growth. in quantitative analysis, steralium and saline-treated tooth samples showed 57.74 ± 5.39* cfu/ml. and 140.71 ± 8.49 cfu/ml. (mean ± standard deviation), respectively (table 2) table 2: quantitative analysis of three-week e. faecalis biofilm formed on tooth substrate for different groups number of bacteria cfu/ml. (mean ± sd) n.s. 140.71 ± 8.49 steralium 57.74 ± 5.39* co+steralium 0* naocl 0* *p< 0.05 with respect to n.s. (one way anova) qualitative assay with the 6-week biofilm on the canal portion showed co+steralium, and naocl has having complete inhibition. table 3 shows the bacterial population in the quantitative assay with the 6-week biofilm for steralium, co+steralium naocl and saline-treated tooth samples. table 3: quantitative analysis of six-week e. faecalis biofilm formed on tooth substrate for different groups number of bacteria cfu/ml. (mean ± sd) n.s. 346.0 ± 78.88* steralium 127.18 ± 17.84 co+steralium 0* naocl 0* *p< 0.05 with respect to n.s. (one way anova) a significant reduction of bacterial population compared with the control saline group, which showed 346.0 ± 78.88* cfu/ ml.. in steralium group, has shown the bacterial count (127.18 ± 17.84), while co+steralium and naocl showed 100% eradication. discussion e. faecalis is an important opportunistic pathogen, with the ability to colonize and persist in the root canal and on retreatment failure, and are resistant to traditional antibiotics (19,20). it is hypothesized that its ability to persist in these environments, as well as its virulence, is a result of its capacity to form biofilms (21). the antibiotic j bagh college dentistry vol. 28(1), march 2016 an evaluation of restorative dentistry 14 resistance has been found to increase up to 1,500 times when compared with planktonic cells (22,23). therefore, testing the effect of an antibacterial irrigant on planktonic cells will not fulfill its effectiveness in in vivo conditions. bacteria-induced dissolution of the dentin surface and the ability of e. faecalis to form calcified biofilm on root canal dentin may be a factor that contributes to their persistence after endodontic treatment (24). it is established that the biofilm-forming capacity and its structural organization are influenced by the chemical nature of the substrate. biofilm experiments conducted on polycarbonate or glass substrate will not provide a true indication of the bacteria-substrate interaction (25). hence, e. faecalis biofilm was formed on a tooth substrate. some irrigants (20) are more effective against planktonic than biofilm cultures, therefore, it is necessary to search for biofilm removal synergistic potential of biofilm removal in conjunction with steralium on e. faecalis planktonic cultures led us to study the antimicrobial activity of co+steralium used in combined form against e. faecalis biofilms. to enhance the efficacy of the irrigants, the action on biofilms should involve the elimination of the eps matrix as well as the bacteria because this matrix could act as an additional source of nutrients and/or as a suitable surface for further cell growth (26). bearing in mind the methodology used, the results presented here suggest that in strategies that are not only active against microorganisms but also exert an effect on the eps matrix. the lack of studies that closely examine biofilm susceptibility to antimicrobial associations and the action against e. faecalis biofilms; the associated use of co+steralium might provide better results than their applications as single agents. novel ways to combat dentin surface contamination of e. faecalis are required. our experiment was conducted to evaluate the use new material and strategy against residual antimicrobial activity on root canals of human teeth cultured with e. faecalis. the uses of a biofilm removal agent with antimicrobial agents as the final irrigation regimen is proposed to biofilm removal eradicate e. faecalis biofilms allow the antimicrobial irrigant to have better access to the microorganism. dissolution of biofilms by irrigant solutions is crucial because a significant area of the root canal system is inaccessible to endodontic instruments. one problem of root canal disinfection in vivo is the ability of organic compounds to inactivate the irrigant antimicrobial activity. the current study is in accordance with the methodology done by kishen et al (24). all the groups were tested in direct contact with the biofilm formed on tooth substrate at different durations (3 weeks and 6 weeks). in the initial antibacterial sensitivity test on planktonic cells, steralium its efficient against e. faecalis; steralium is a potent antimicrobial agent of proven substantivity, although it was not able to eradicate e. faecalis biofilms at any of the time periods we assayed. there is a need to use steralium together with another chemically compatible agent that enhances its efficacy against biofilms. the pilot study showed that there is no antimicrobial bodedex® forte effect against e. faecalis while the combined used of bodedex® forte as co with steralium has been shown to exert less antimicrobial activity against e. faecalis planktonic than steralium alone but higher against biofilm cultures. bodedex® forte is non-ionic and amphoteric surfactants, removing biofilm agent that favors the action of irrigants, thus permitting more effective elimination of endodontic infection. although in our case, the canals were refilled with bhi broth during the incubation period so that there would be an abundance of nutrients available for the bacteria. both group 3 and 4 specimens were negative cultures on the three and six week that these agents eliminated the infected biofilm and the antibacterial strength of the agents used no regrowth after six week may indicates that eradication of the bacteria was complete. naocl was effective at 0.5%, of the fact that sessile bacteria on surfaces or present within biofilm are much less readily inactivated than planktonic cells. a biocide gradient is produced throughout the biofilm, so that in thick biofilm there will be an ‘‘in-use’’ concentration as the biocide penetrates into the community25. the concentration of 60 mg/ml used in this study was found to be effective as an antibacterial against e. faecalis, and further reduction in concentration, when used in vivo, is still feasible because the bacterial count is expected to be much less than what we have used. five percent sodium hypochlorite is proven to be the best among all the groups in planktonic microbial inhibition, and exhibited excellent antibacterial activity both in 3-week and 6-week biofilm. results from previous study reported that naocl was capable of eradicating e.faecalis biofilm after one minute at a concentration of 0.00625% that was grown in the calgary biofilm forming device (27). but the same concentration may not be effective on biofilm formed on tooth j bagh college dentistry vol. 28(1), march 2016 an evaluation of restorative dentistry 15 substrate. co+steralium showed promising antibacterial efficacy on 3and 6-week biofilm along and 5% sodium hypochlorite. while naocl is a very caustic, nonspecific agent whose action is not limited to necrotic tissue (28), and it has deleterious effects on dentine that include reduction of the elastic modulus and the flexural strength (29,30). the co+ steralium appear to be sufficient susceptible to disinfectants dentin from tested microorgansim with less limitation of naocl. our experiments suggest that, steralium and bodedex® forte show a promise in this context. further investigations need to be carried out to assess its use against a range of other pathogens and its potential to use bodedex® forte with other potent antibiotic such as chlorhexdin. within the limitations of this study, 5% sodium hypochlorite showed maximum antibacterial activity against 3and 6-week e. faecalis biofilm formed on tooth substrate. the use of co+steralium alternatives as a root canal irrigant might prove to be advantageous considering the several undesirable characteristics of naocl. further research is needed to conclusively recommend co+steralium as a root canal irrigant. references 1. sundqvist g, figdor d, persson s, sjo¨gren u. microbiologic analysis of teeth with failed endodontic treatment and the outcome of conservative retreatment. oral surg oral med oral pathol oral radiol endod 1998; 85: 86–93. 2. chavez de paz le. redefining the persistent infection in root canals: possible role of biofilm communities. j endod 2007; 33: 652–62. 3. orstavik d, haapasalo m. disinfection by endodontic irrigants and dressings of experimentally infected dentinal tubules. endod dent traumatol 1990; 6: 142– 9. 4. pablo ovd, estevez r, peix sanchez m, heilborn c, cohenca n. root anatomy and canal configuration of the permanent mandibular first molar: a systematic review. j endod 2010; 36: 1919–31. 5. love rm. enterococcus faecalis—a mechanism for its role in endodontic failure. int endod j 2001; 34: 399– 405 6. pinheiro et, gomes bp, ferraz cc, sousa el, teixeira fb, souza-filho fj. microorganisms from canals of root-filled teeth with periapical lesions. int endod j 2003; 36: 1-11. 7. graninger w, ragette r. nosocomial bacteremia due to enterococcus faecalis without endocarditis. clin infect dis 1992; 15: 4957. 8. sijpkens yw, buurke ej, ulrich c, van asselt gj. enterococcus faecalis colonisation and endocarditis in five intensive care patients as late sequelae of selective decontamination. intensive care med 1995; 21: 231-34. 9. khardori n, wong e, carrasco ch, wallace s, patt y, bodey gp. infections associated with biliary drainage procedures in patients with cancer. rev infect dis 1991; 13: 587-91. 10. sandoe ja, witherden ir, au-yeung hk, kite p, kerr kg, wilcox mh. enterococcal intravascular catheter-related bloodstream infection: management and outcome of 61 consecutive cases. j antimicrob chemother 2002; 50: 577-82. 11. costerton jw, stewart ps, greenberg ep. bacterial biofilms: a common cause of persistent infections. science 1999; 284: 1318–22. 12. distel jw, hatton jf, gillespie mj. biofilm formation in medicated root canals.j endod 2002; 28: 689–93. 13. sterillium®. www.bode-science-center.com 14. bodedex® forte. www.bode-science-center.com 15. dunavant tr, regan jd, glickman gn, et al. comparative evaluation of endodontic irrigants against e. faecalis biofilm. j endod 2006; 32: 527–31. 16. spa°ngberg l, engstro¨m b, langeland k. biologic effects of dental materials. iii toxicity and antimicrobial effect of endodontic antiseptics in vitro. oral surg oral med oral pathol oral radiol endod 1973; 36: 856–71. 17. mccomb d, smith dc. a preliminary scanning electron microscopic study of root canals after endodontic procedures. j endod 1975; 1: 238–42. 18. torabinejad m, khademi aa, babagoli j, et al. effect of mtad on the surface of instrumented root canals. j endod 2003; 29: 170–5. 19. pinheiro et, gomes bpfa, ferraz ccr, et al. evaluation of root canal microorganisms isolated from teeth with endodontic failure and their antimicrobial susceptibility. oral microbiol immunol 2003; 18: 100–3. 20. kanisavaran zm. chlorhexidine gluconate in endodontics: an update review. int dent j 2008; 58: 247–57. 21. sandoe ja, wysome j, west ap, heritage j, wilcox mh. measurement of ampicillin, vancomycin, linezolid and gentamicin activity against enterococcal biofilms. j antimicrob chemother 2006; 57: 767–70. 22. mah tfc, o’toole ga. mechanisms of biofilm resistance to antimicrobial agents. trends microbiol 2001; 9: 34–9. 23. socransky ss, haffajee ad. dental biofilms: difficult therapeutic targets. periodontology 2000 2002; 28:12– 55. 24. kishen a, george s, kumar r. enterococcus faecalismediated biomineralized biofilm formation on root canal dentine in vitro. j biomed mater res a 2006; 77: 406–15. 25. mcbain aj, gilbert p, allison dg. biofilms and biocides: are there implications for antibiotic resistance? rev environ sci technol 2003; 2: 141–6. 26. simo˜ es m, pereira mo, vieira mj. effect of mechanical stress on biofilms challenged by different chemicals. water res 2005; 39: 5142–52. 27. arias-moliz mt, ferrer-luque cm, espigares-garcia m, et al. enterococcus faecalis biofilms eradication by root canal irrigants. j endod 2009; 35: 711–4. 28. seltzer s, farber pa. microbiologic factors in endodontology. oral surg oral med oral pathol 1994; 78: 634–45. 29. sim tp, knowles jc, ng yl, gulabivala k. effect of sodium hypochlorite on mechanical properties of dentine and tooth surface strain. int endod j 2001; 34: 120–32. http://www.bode-science-center.com http://www.bode-science-center.com j bagh college dentistry vol. 28(1), march 2016 an evaluation of restorative dentistry 16 30. grigoratos d, knowles j, ng yl, gulabivala k. effect of exposing dentine to sodium hypochlorite and calcium hydroxide on its flextural strength and elastic modulus. int endod j 2001; 34: 113-9. huda f.doc j bagh college dentistry vol. 25(4), december 2013 evaluation of fracture restorative dentistry 12 evaluation of fracture strength of endodontically treated teeth restored by milled zirconia post and core with different post and core systems (an in vitro comparative study) huda musaa'd lafta, b.d.s. (1) adel farhan ibraheem, b.d.s., m.sc. (2) abstract background: restoration of root canal treated teeth with a permanent restoration affect in the success of endodontically treated teeth. this in vitro study was performed to evaluate and compare the fracture strength of endodontically treated teeth restored by using custom made zirconium posts and cores, prefabricated carbon fiber, glass fiber and zirconium ceramic posts. materials and method: forty intact human mandibular second premolars were collected for this study and were divided into five groups. each group contains 8 specimens: group1: teeth restored with carbon fiber posts; group2: teeth restored with glass fiber posts; group3: teeth restored with zirconium ceramic prefabricated posts; group4: teeth restored with zirconium posts and cores (copy milling); group5: (control group).for groups 1, 2, 3, and 4; crowns were removed horizontally at the level of cement-enamel junction. endodontic therapy was then done for all specimens in these groups using step-back technique.these specimens received standardized posts preparation (10mm depth), and then mounted in acrylic resin blocks. panavia f 2.0 dual cure resin cement was used for cementation. the core build up was done with composite (filtek p60). the specimens were then stored in saline and were subjected to compressive loads parallel to their long axes using universal testing machine (wp 300) until failure. results: data obtained were analyzed by one-way analysis of varianceand student t-test. the results showed that zirconium posts and cores possessed the highest significant differences followed by glass fiber posts, carbon fiber posts, and prefabricated ceramic zirconium posts. there were no significant differences between glass fiber, carbon fiber, and control group. the specimens were examined to determine the root fracture patterns and locations. conclusion: in the present study the fiber post treated teeth showed significantly more desirable fracture patterns compared to those restored with zircon posts. key words: fiber posts, manual milling, fracture strength. (j bagh coll dentistry 2013; 25(4):12-16). introduction functional, structural and esthetic rehabilitation of pulpless teeth are critically important to ensure successful outcome (1). as a rule, root canal treated teeth are weak and brittle than intact teeth because of loss tooth structure, canal enlargement and cavity preparation (2). an ideal restoration should provide esthetic; function and protection for endodontically weakened teeth. a post is a rigid structure that can be inserted in the root canal after root canal treatment (2). recent studies suggest that the post should show an elastic modulus similar to dentin, which can efficiently transmit the stress from the post to the root structure(2).there are a wide range of endodontic posts from metallic to nonmetallic, rigid to flexible and esthetic to non-esthetic (3).the aim of this study is to evaluate and compare the effect of different types of post systems on fracture strength of endodontically treated teeth which are restored by zirconium posts and cores, prefabricated carbon fiber, glass fiber and zirconium ceramic posts. (1) master student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. materials and methods forty sound lower second premolars recently extracted for orthodontic purposes, of comparable size and shapes, were selected. all teeth were cleaned and stored in 0.1% thymol at room temperature. the coronal portions of thirty two teeth were removed using a diamond saw mounted on straight hand pieces under water spray, perpendicular to the long axis of each tooth to produce a flat surface. the length was adjusted at 15 mm with digital vernier before cutting (4). the canals of all teeth were prepared chemomechanically by step-back technique. starting with file size #15 (k-file dentsply, ballalgues, switzerland) entered into the canal to full working length (14mm) up to size #45 as a master apical file (maf); then stepping back 1mm fore every successively larger instrument till size #60. irrigation and recapitulation were carried out to remove debris and prevent canal blockage. the final irrigation was carried with 5ml of 2.5% naocl solution followed by 5ml of distilled water then the roots were dried with paper points. the prepared canals were obturated by cold lateral condensation technique of guttapercha points using apexit plus sealer (ivoclar-vivadent, j bagh college dentistry vol. 25(4), december 2013 evaluation of fracture restorative dentistry 13 schaan, liechtenstein). to simulate the periodontium, root surfaces were dipped into melted sticky wax to a depth of 2 mm apical to the facial cej junction to produce a 0.2 to 0.3 mm layer approximately equal to the average thickness of the periodontal ligaments. mold construction roots mounted in cold cure acrylic resin using a metal mold with (20 mm length and 20 mm width); by using dental surveyor. after acrylic polymerization, root was removed and cleaned from wax (wax spacer)(5). condensation silicon impression material light body (aquasil ultra lv, dentsply) was delivered into the acrylic resin alveolus. the tooth was then reinserted into the test block (6). sample grouping the simples were randomly divided into five groups (n=8) according to the type of posts. group 1: endodontic treated teeth restored with carbon fiber posts (carbonite®, nordin, switzerland); group 2: endodontic treated teeth restored with glass fiber posts (glassix®, nordin, switzerland); group 3: endodontic treated teeth restored with zirconium ceramic prefabricated posts(zirix®, nordin, switzerland); group 4: endodontic treated teeth restored with zirconium posts and cores (copy milling); group 5: sound teeth (control group). post space preparation was done with a low – speed straight hand piece attached to a dental surveyor with standard diameter (rubber stopper was attached to the pessoreamer (size nr4 ø 1.50, nordin, switzerland) the depth was adjusted to 10mm thus 4-5mm of guttapercha kept apically (7,8)as in figure(1). for all specimens in groups 1, 2 and 3 the post were tried in to verify their fitness. figure 1: preparation of post space. wax pattern was constructed for each specimen in group 4 by direct waxing technique using type ii blue inlay wax. a core with 5mm height, 6mm diameter was constructed by using copper ring. the wax patterns were invested, casted in to nickel-chromium alloy (eisenbacherdentalwaren, germany) and deinvested. the metal cast posts and cores were cleaned, finished and tried on their alternative teeth samples. the zirkon zahn unite used for milling of zirconium posts and cores.the metal posts were then seated in its position in the holding plate of the copy milling machine, the holding plate and zirconium block were attached to the clamping table of the copy milling machine. the zirconium oxide copy was formed simultaneously on the milling side.the milled structure is 30% larger than the wax pattern as zirconia undergoes shrinkage of 30% after sintering of milled restorations (8). posts cementation all post spaces were cleaned, dried and etched with 37% wt phosphoric acid gel (for 10seconds) then washed with distilled water (9). ed primer ii (kuraray, japan) liquid a and b (as a bonding agent) mixed and applied; left for thirty (30 seconds), and air jet for ten seconds. panavia f 2.0 dual-cure dental adhesive system (kuraray, japan) was used as cementing medium (figure 2a),while the post attached to the horizontal arm of the surveyor, the mixture was applied to the post surfaces. the post was then seated in to its respective space, using 2 kg constant load (figure 2b). excessive material was removed by a micro brush within 40 seconds, and then light cured applied for 20 seconds (7,8). figure 2: (a and b): cementation. j bagh college dentistry vol. 25(4), december 2013 evaluation of fracture restorative dentistry 14 fabrication of zirconium posts core builds up procedure for groups 1, 2, and 3, the coronal portion of the posts (3mm) and the remaining tooth structure (2mm coronal to the cej) were cleaned from debris. a phosphoric acid 37%wt were applied to the area (for 15 seconds), after washing the acid bonding resin was applied using micro-brush and cured for 20 seconds.a plastic cylindrical matrix of 5 mm height and 6mm diameter used as a mold to build a standard core.after packing of composite in plastic matrix celluloid strip was placed over, one mm thickness glass slide was pressed under a load of 200gm for 1 minute (10) (figure 3). the composite was light cured using a halogen light cure device for 40 second. after curing and removing the cylinder plastic matrix from the specimens, a further curingfor 60 seconds, was carried out to all sides.(11) figure 3: core bullied up testing procedure: the samples were placed on the flat table of the universal testing machine (wp 300) (zwick, gunt, humburg, germany) (figure 4). a continuously increased compressive load was applied perpendicular on the flat occlusal surface of the core until failure. the load was measured in newton (n). the mean failure load for each group was calculated. (13) figure 4: testing procedure. failure location after completion of testing procedures, all the specimens were examined using a magnifying lens to determine the root fracture patterns and locations. the fracture patterns were divided into two groups (14)(figure 5): 1) coronal fracture (desirable fracture). 2) root fracture (undesirable fracture). figure 5: failure location results descriptive statistics the means, standard deviations (s.d) of the fracture strength values with minimum and maximum values of each group were collected as in figure (6). oneway analysis of variance (anova) was applied.the result was high significant difference among groups.further analysis of the result using student's ttest was applied in order to localize the source of significance of the difference between groups.the results of t-test between the groupscan be summarized as following group 1: shows non significant difference with group2 and group 5and significant difference with group 3.while high significant difference with group 4. group2: shows non significant difference with group5 and shows high significance with group3 and group 4. m ea n s o f fr ac tu re s tr en gt h in figure 6: the bar charts showing means of fracture strength in n for all groups 1679.5 1820.6 1131 2711.25 1710.5 0 500 1000 1500 2000 2500 3000 mean 1 2 3 4 5 6 j bagh college dentistry vol. 25(4), december 2013 evaluation of fracture restorative dentistry 15 group 3: shows significance difference with group5 and shows high significance difference with group4. group 4: shows high significance difference with group5. failure location group 1: seven teeth were fractured at the coronal part (composite core) and one tooth was with catastrophic failure (root fracture at the apical part). group 2 and group 3: all the fractures were in the coronal part (composite cores). no root failures. group 4: one tooth was fractured at the coronal part. the rest seven teeth were fractured at the apical part. group 5: all teeth were fractured at the coronal parts. discussion sample selection since prefabricated posts were used in this study, human lower second premolars have been used because they have round to slightly oval shape canals. although, careful selection of the sample was performedto standardize the experimental procedures, in each group a range of failure load values could not be avoided. the variability of physical properties of human teeth may be a reason for such data range. (4) periodontal ligament simulation thin layers of condensation silicon are used to simulate the periodontal ligament, provide a cushioning effect resembling the clinical conditions, and avoid the external reinforcement of the root structure by the rigid acrylic resin. (6,14) post space preparation and length the minimum post length should be as long as the clinical crown, so the minimum length of 10 mm was selected as post length to achieve the standard condition (13). compression test attempts were made to simulate the force of the oral cavity on the roots on mandibular first premolars, while the teeth were oriented vertically in the alveolar bone (14). occlusal surfaces of cores were prepared uniformly so that the forces can be applied at the long axis and at the middle of the teeth. fracture strength group 1 (carbon fiber posts) and group 2 (glass fiber posts) group 1 has lower mean fracture strength values compared with group 2 with non significant difference. this finding is in consistence with that obtained by mannocci et al. 16, barjau et al.17. this may be due to that the carbon fiber postshave elastic modulus most similar to dentine, which means the system had more favorable performance with lower failure rate. in comparison between fiber posts and zirconia posts, the fiber posts are more elastic, so it is rational that the fracture strength of fiber treated groups be lower than zirconia treated ones. these findings are consistent with rosentrittet al.3 and in contrary to mortazavi et al 13. the mean of fracture strength of group 1 was lower than group 5 (control group), but statically the difference was not significant. the result of the present study agrees withanna-maria et al18who found that intact teeth without posts showed higher mean of fracture load. the mean fracture strength of group 2 was higher than group 5, but statically the difference was not significant. these results agree with torabi andfattahi14. these results seem to be more logical as bonding ability of glass fiber posts enables them to reinforce the root, although reinforcement is not enough to support root from fracture. group 3 (zirconium ceramic prefabricated post): this group showed the lowest fracture strength mean values than other groups. statistically the difference was significant. this means that, zirconium ceramic posts failed with least amount of force compared with other groups. these results agree with rosentritt et al 3 and bittner et al12 one possible of these results could be due to the lack of homogeneous chemical adhesion between prefabricated zirconium posts and the resin cement used in this study rosentritt et al3 and ferrari et al19 another possible cause may be related to the coronal end design of prefabricated zirconium poststhat have many sharp angles (unlike other posts) which act as stress concentration areas under the continuous compression loading, causing crack propagation and fracture of surrounding core materialas compered with other groups (prefabricated posts g1 and g2). j bagh college dentistry vol. 25(4), december 2013 evaluation of fracture restorative dentistry 16 group 4 (zirconium-oxide single unite post and core) this group showed the higher mean failure load values than other groups with high significant difference. this finding agrees with wrbaset al12. in this group, both posts and cores are in single unit (one material) so the load will be directed to the weakest part which is the root. group 5 (control group) teeth without preparation served as control group to assess the influence of post and core foundation on over all restored tooth. failure location when the fracture occurs, the pattern of fracture is important as it acts as guidance for the restorability of fractured teeth. in the present study, the fiber post treated teeth showed significantly more desirable fracture patterns compared to those restored with zircon posts. this result agrees with mortazaviet al13. this result suggests that zirconium posts and cores can be used when esthetic demands are important and the anatomy of the root canal and/or the extensive loss of coronal tooth portion require the use of custom post. single unit zirconium post and core may be indicated when ceramic crown is used. references 1. alessandro rogériogiovani, luizpascoalvansan, manoeldamião de sousa neto, silvana maria paulino. in vitro fracture resistance of glassfiber and cast metal posts with different lengths. j prosthet dent 2009; 101:183-8. 2. michael mc, husein a, bakar wz, sulaimanb e. fracture resistance of endodontically treated teeth: an in vitro study. arch orofac sci 2010; 5: 36-41. 3. rosentritt m, fürer c, behr m, lang r, handel g. comparison of in vitro fracture strength of metallic and tooth-coloured posts and cores. j oral rehabil 2000; 27: 595-601. 4. nu'man fg. fracture resistance of endodontically treated teeth restored by prefabricated posts using different types of cements. m.sc. thesis, dept. of conservative dentistry, collage of dentistry university of baghdad 2001. 5. al-ansari sa, alkhafaji ah. the influence of posterior composite type and application technique on the fracture resistance of maxillary premolar teeth (an in vitro study). j bagh coll dentistry 2009; 21(1):1-4. 6. naosuke kumagae, wataru komada, yuji fukui, daizo okada, hidekazu takahashi, keiichi yoshida and hiroyuki miuai. influence of the flexural modulus of prefabricated and experimental posts on the fracture strength and failure mode of composite resin cores. dent mater j 2012; 31(1): 113–9.[ivsl] 7. abdulfatah mn. comparison of regional bond strength of post space of fiber-reinforced post luted with two types of cements at different testing times. m.sc. thesis, dept. of conservative dentistry, collage of dentistry university of baghdad, 2012. 8. dayalan m, jairaj a, nagaraj kr, savadi rc. an evaluation of fracture strength of zirconium oxide posts fabricated using cad-cam technology compared with prefabricated glass fiber posts. j indian prosthodont soc 2010; 10(4): 213–18 9. pedreira ana paula rv, luiz fernando pegoraro, mario fernando de goes, thiagoamadeipegoraro, ricardo marinscarvalho. microhardness of resin cements in the intraradicular environment. effects of water storage and softening treatment. dent mater 2009; 25: 868–76.[ivsl] 10. ciccone –nogueirajc, borsatto mc, de souza-zaroni wc, renata pereira ramos, regina guenka palmadibb. microhardness of composite resins at different depths varying the postirradiation time. j appl oral sci 2007;15(4): 305-9 11. wrbas jf, schirrmeister mj, altenburger a. agrafioti, hellwing e. bond strength between fiber posts and composite resin cores: effect of posts surface silanization, international journal 2007; 40: 538-43. 12. bittner nurit, thomas hill, anthony randi. evaluation of a one-piece milled zirconia post and core with different post-andcore systems: an in vitro study. j prosthet dent 2010; 103: 369-79. 13. mortazavi v, fathi mh, katiraei n, shahnaseri s, badrian h, khalighinejad n. fracture resistance of structurally compromised and normal endodontically treated teeth restored with different post systems: an in vitro study. dent res j 2012; 9: 185-91. 14. torabi k, fattahi f. fracture resistance of endodontically treated teeth restored by different frc posts: an in vitro study. indian j dent res 2009; 20: 282-7. 15. stockton lw. factors affecting retention of post systems: a literature review. j prosthet dent 1999; 81 (4): 380-5 16. mannocci f, ferrari m, watson tf. intermittent loading of teeth restored using quartz fiber, carbonquartz fiber, and zirconium dioxide ceramic root canal posts. j adhes dent 1999; 1: 153-8. 17. barjau-escribano, j. l. sancho-bru, l. fornernavarro, p. j. rodríguez-cervantes, a. pérezgonzález, and f. t. sánchez-marín. influence of prefabricated post material on restored teeth: fracture strength and stress distribution. operative dentistry 2006; 31(1): 47-54. 18. anna-maria le bell-ronnlof, lippo vj, lassilaa, ilkka kangasniemi, pekka k. vallittu. load-bearing capacity of human incisor restored with various fiberreinforced composite posts. dental materials 2011; 27: 107-15. 19. ferrari m, vichi a, mannocci f, mason pn. retrospective study of the clinical performance of fiber posts. am j dent 2000; 13: 9-13. j bagh college dentistry vol. 31(4), december 2019 oxidative status 25 oxidative status among a group of pregnant women in relation to gingival health condition sarar nassir al-najjar, b.d.s. (1) baydaa hussein, b.d.s., m.sc. (2) abstract background: pregnancy as a systemic condition causes changes in the functioning of human body as a whole and specifically in the oral cavity and it also is considered as a stressful condition. these changes may favor the increase of oxidative stress. aim: the aim of this study was to estimate the level of marker of oxidative stress (malondialdehyde) and antioxidant (uric acid) in saliva of pregnant compared to non-pregnant women and to assess the gingival health condition in both groups. additionally, unstimulated salivary flow rate was determined in both groups. subjects, materials and methods: the study group consisted of sixty pregnant women, they were divided into three equal groups according to trimester (20 pregnant women for each trimester), and they were selected randomly from the maternal and child health care centers in baghdad city, their age range was 20-25 years. in addition to 60 newly married non-pregnant women as a control group and matched with age. collection of unstimulated salivary samples was carried out under standardized conditions. dental plaque and gingival indices were used for recording the oral hygiene and gingival health respectively. salivary flow rate was measured then salivary samples were analyzed to determine the level of salivary antioxidant (uric acid) and lipid peroxidation biomarker of oxidative stress (malondialdehyde). result: the data analysis of the present study found that the level of salivary malondialdehyde was higher among pregnant women compared to non-pregnant controls with statistically significant difference (p<0.05), while salivary uric acid was statistically significantly lower among the pregnant women compared to non-pregnant controls (p<0.05). salivary analysis demonstrated that the salivary flow rate was statistically significantly lower among the pregnant women compared to non-pregnant controls (p<0.05). the values of plaque and gingival indices were higher among pregnant women compared to non-pregnant controls with statistically significant difference (p<0.05). the correlation of gingival index with plaque index in study and control group was significant (p<0.05), while with others variables were non-significant (p>0.05). conclusion: the current study showed an increase in oxidative status in saliva during pregnancy that could affect gingival health which was also affected by oral hygiene. keywords: lipid peroxidation, oxidative stress, pregnancy, gingival health, salivary antioxidant, salivary flow rate. (received: 15/2/2018; accepted: 13/3/2018) introduction periodontal diseases are generalized term for a range of pathological conditions affecting the supporting and investing structures of the tooth including bone, gingival tissue and periodontal ligament (1). generally, periodontal diseases have been divided into two major categories; gingivitis and periodontitis (2). gingivitis is characterized by inflammation of marginal gingival tissues with no detectable loss of bone or connective tissue attachment (3). it may progress to periodontitis, which is gum disease that spread below the gum line and affects the tissue and bones that support the teeth (4). the main etiological factor of gingivitis is dental plaque (5) which is defined as non mineralized, sticky soft bacterial mass or deposits which is tightly adherence to the tooth surface and other solid in the mouth and resists removal by salivary flow or by water spray (6). the specific role of antioxidant is to neutralize rampaging free radical and thus reducing its capacity to damage (7). 1. m. sc. department of pedodontic and preventive dentistry, university of baghdad, g.p. at ministry of health and environment. 2. assist professor. department of preventive dentistry, college of dentistry, university of baghdad. it was found that the salivary antioxidants inhibit the oxidation reaction and provide protection against reactive oxygen species induced damage of gingival tissues (8). triveda et al. (9) and zhang et al. (10) reported increased oxidative stress and mda in periodontitis, also canakci et al. (11) guentsch et al. (12) have shown a reduction in both systemic and local antioxidant capacity antioxidant concentration of gingival crevicular fluids in periodontitis patients. pregnancy, is a stressful condition in which many metabolic and physiological functions are changes to a considerable extent (13). so the main physiological and hormonal changes in the life of a woman occur during pregnancy (14), and the oral cavity is one of the target areas involved in these changes (15). pregnancy gingivitis, defined as gingival inflammation initiated by plaque and exacerbated by endogenous sex steroid hormones (16). clinical studies have reported an increase in the extent and severity of gingival inflammation during pregnancy, which abates postpartum with the fall in hormone production (17,18). the link between pregnancy and periodontal inflammation and the effect of pregnancy on periodontal health has been studied extensively and only recently j bagh college dentistry vol. 31(4), december 2019 oxidative status 26 evidences indicated an inverse relationship to systemic health that periodontal disease may affect the wellbeing of the fetus by elevating the risk for low birth weight & preterm infant (19,20). pregnancy is a physiological state accompanied by a high metabolic demand and elevated requirements for tissue oxygen. this raised oxygen demand increases the rate of production of reactive oxygen species (ros) and women with normal pregnancies experience increased oxidative stress (os) and lipid peroxidation (lpo). the placenta is a major source of os during pregnancy (21,22). salivary physicochemical characteristics also affected during pregnancy. several studies showed controversy regarding salivary flow mutlak (23) reported increased in stimulated salivary flow rate, while, sulaiman (24) reported opposite result. on the other hand, al-zaidi (25) reported no change in salivary flow rate among pregnant as compared with non-pregnant women. as far as it is known, there were no previous iraqi studies concerned with the relation between reactive oxygen species, salivary antioxidant (uric acid) and gingival health condition among pregnant women; therefore, it was decided to conduct this study. materials and methods the total sample for this study consisted of one hundred and twenty married women aged 2025 years who were attending maternal and child health care centers in baghdad city. they were divided into two groups: the study group which included 60 pregnant women who further subdivided into three subgroups according to trimester (20 women for each trimester of pregnancy). while the control group included 60 non-pregnant married nulliparous women (not being pregnant before) having a history of regular menstrual cycles (28–30 days), they were selected from companions of pregnant women; those women were matched with age. all women should have at least twenty teeth to be examined. exclusion criteria in this study include women with systemic diseases that may affect oral health, or those who had medications which may affect periodontal health condition or had course of antiinflammatory and antibiotic drugs during the last month before examination and those who were smoking, obese, used dietary supplement (vitamins, folic acid) or had a history of abortion, history of polycystic ovaries, hormonal disturbances, used of contraceptive, non-pregnant women on mensural cycle, wearing fixed or removable dental prostheses. all participants signed informed consents, and the protocol of the study had been approved. the collection of unstimulated salivary sample was performed under standardized condition following the instructions cited by navazesh and kumar (26). plaque index (27) (pii) was used for recording oral hygiene, while gingival index (28) (gi) for asessing the gingival health condition. salivary flow rate was expressed as milliter per minute (ml/min) (29). then salivary samples were taken to the laboratory for biochemical analysis at the poisoning consultation center/gazi al-hariry hospital. the level of salivary antioxidant (uric acid) and lipid peroxidation biomarker of oxidative stress (malondialdehyde) was determined calorimetrically using the spectrophotometer (cecil ce 1011, uk). salivary uric acid level was measured using a ready kit (spinreact, spain), while malondialdehyde (mda) was measured using malondialdehyde assay kit (chemical point germany) according to the manufactured instructions. data analysis was conducted by application of spss program (spss version 21). by using shapiro-wilk test to determine whatever the data was normally distributed or not. normal distribution of data was not achieved, so following non-parametric tests were used. wilcoxon-sum rank test was used to compare between two independent samples. spearman correlation was used to evaluate the association between two nonparametric quantitative or ordinal variables. pvalues less than 0.05 were recorded as statistically significant. results table (1) shows the values of salivary mda and uric acid among the study and control groups. it was found that the salivary mda was higher among pregnant women as compared to nonpregnant women with statistically significant difference (p<0.05). on the other hand, salivary uric acid was lower among pregnant women than in non-pregnant controls with statistically significant difference (p<0.05). table (2) shows the values of salivary flow rate among the study and control groups. it was found that the salivary flow rate was lower among pregnant women than non-pregnant women with statistically significant difference (p<0.05). table (3) shows the values of plaque and gingival indices among the study and control groups. it was found that the values of plaque and gingival indices were higher in the study group than that in the control group with statistically significant difference (p<0.05). table (4) illustrates the correlations between gi with oral variable. a positive and statistically significant correlation was found between gi and dental plaque (p<0.05) in both study and control group, while all others correlations were not statistically significant (p>0.05). j bagh college dentistry vol. 31(4), december 2019 oxidative status 27 table 1: salivary malondialdehyde and uric acid (median, mean rank) among the study and control groups. variable group wilcoxon sum rank test pregnant non-pregnant median mean rank median mean rank p-value malondialdehyde (μmol /dl) 0.07 74.39 0.04 46.61 0.000* uric acid (mg/dl) 2.45 51.55 2.55 69.45 0.005* *significant (p<0.05) table 2: salivary flow rate (median, mean rank) among the study and control groups. variable group wilcoxon sum rank test pregnant non-pregnant median mean rank median mean rank p-value flow rate (ml/min) 0.10 55.35 0.10 65.65 0.005* * significant (p<0.05) table3: plaque index and gingival index (median, mean rank) among the study and control groups. * significant (p<0.05) table 4: correlation coefficient between gingival index with oral variables among study and control groups. variable pregnant non-pregnant gi gi r p r p malondialdehyde (μmol /dl) 0.186 0.154 -0.061 0.644 uric acid (mg/dl) -0.106 0.419 -0.041 0.757 pli 0.559 0.000* 0.879 0.000* flow rate (ml/min) -0.037 0.782 -0.028 0.830 * significant (p<0.05) discussion pregnancy is a normal physiological phenomenon with many biochemical changes (30). saliva is considered as a mirror of the human body’s health that reflects the normal internal characteristics and disease as most compounds found in blood are also present in saliva (31,32). in the present study, data analysis showed that flow rate of saliva was lower among the pregnant women than among non-pregnant women, pregnant women are uncomfortable and distressed due to nausea in pregnancy and certain hormones contribute to this relationship (morning sickness). pregnancy induces decreased gastroesophageal sphincter tone and prolonged gastric emptying times. these changes along with decreased esophageal tone lead to changes in the saliva flow (33, 34). this result was also reported by others (35,36), while an opposite finding was reported by other studies (33,37). the result of current study showed that the concentration of lipid peroxidation (mda) was higher among the study group than that among the control group. the same result was also reported by other studies (38,39). this could be due to the fact that pregnancy is a physiological condition of stress and hyper-dynamic circulation (40). furthermore, in a healthy placenta, there is an increase in oxidative stress levels, due to a high placental mitochondrial activity and increase partial pressure of oxygen in pregnant women resulting in an increase in ros production (41,42). on the other hand, in the present study, the salivary concentration of uric acid was lower among pregnant women than that among the nonpregnant controls. the same result was also reported by other study (43). the result of the present study could be attributed to the fact that the renal system undergoes marked changes in function during pregnancy due to hormonal variable group wilcoxon sum rank test pregnant non-pregnant median mean rank median mean rank p-value pli 1.10 90.48 0.20 30.52 0.000* gi 1.40 90.50 0.20 30.50 0.000* j bagh college dentistry vol. 31(4), december 2019 oxidative status 28 effects, the increased metabolic load of the fetus and the outflow obstruction of the ureters by the enlarging uterus (44). furthermore, the decreased salivary uric acid level among study group in comparison to the control group could be an indication of increased consumption and/or decreased production of antioxidants and the increased consumption of antioxidants is due to increased scavenging of oxidants (45). it was documented that salivary uric acid acts as a major salivary antioxidant which participate in 85% of the total antioxidant capacity in saliva and provide a protection against oxidative stress (46). it was found an association between exist serum and salivary uric acid concentration, so that, saliva testing may be a useful non-invasive approach for monitoring disease and health condition (47). the current study showed that the value of the pli was found to be higher in the study group than that in the control group. the same result was also reported by others (23,48). the higher value of dental plaque could be attributed to poor oral hygiene among pregnant women in comparison with nonpregnant controls and this may be explained by that pregnancy is a stressful condition and associated with many physiological and psychological events that sequentially lead to more self-neglect. while the young newly married nonpregnant women are more taking care of their appearance including their oral hygiene (49). another explanation for the higher value of dental plaque among pregnant women could be due to a reduction in salivary flow rate among them. it was proved that the salivary flow rate may play an important role in relation to plaque accumulation since a decrease in salivary flow rate lead to a decrease of irrigation action of saliva (50), so dental plaque increased. the result of the present study showed an increase in gi value among pregnant women in comparison to the controls and this could be attributed to the followings: 1. poor oral hygiene as indicated by the higher plaque accumulation among the pregnant women than non-pregnant women. it was proven that dental plaque is the main etiological factor of gingivitis (5) and this fact is supported by a positive and statistically significant correlation between dental plaque and gingivitis in this study and the same correlation was also reported by others (25,51). 2. decreased salivary flow rate among pregnant women as compared to non-pregnant women. saliva may affect periodontal diseases through its physiochemical properties (52), since decrease of salivary flow rate lead to reduce of washing action of saliva and oral dryness as well as protective constituents decreased with decreased flow rate (50). previous iraqi studies also reported the same correlation (23,48). 3. lower antioxidant level which indicated by a decrease in salivary uric acid among pregnant women as compared to the controls since antioxidants enhance periodontal health by providing protection against ros-induced damage of periodontal tissues (53). 4. the significant higher level of lipid peroxidation biomarker (mda) among pregnant women and this supported by positive correlation between gi and mda. since reactive oxygen species damage periodontal tissues by causing peroxidation the lipid of the cell wall and hence cell death (54). furthermore, another explanation for higher level of gi among pregnant women as compared to control could be the hormonal changes during pregnancy. the elevated levels of estrogen and progesterone in pregnancy could alter the connective tissue ground substance by increase fluidity and affect degree of keratinization of gingival epithelium, the decrease in the keratinization of gingiva, together with an increase in epithelial glycogen, result in decreased effectiveness of the epithelial barrier in pregnant women and make gingival more sensitive to injury (55). when the female sex hormones act at high concentrations for prolonged periods, an increase in the permeability within the periodontal vascular system could occur. additionally, it was reported that there was a significant connection between pregnancy-related vomiting and increased gingival inflammation and it was speculated that the main reason for this was impaired capability for proper brushing (56). pregnant women can be considered as an important target group with special periodontal health needs. measuring of oxidative condition in saliva could be used as a mean for periodontal health monitoring and treatment success during the periodontal maintenance period. furthermore, pregnant women are in need to public preventive 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(p<0.05)غير حامل ، في حين كان حمض اليورك اللعابي أقل إحصائيا بشكل ملحوظ بين النساء الحوامل مقارنة إلى ضوابط(p<0.05)إحصائية . (p<0.05)اللعابي أن معدل تدفق اللعاب كان أقل إحصائيا بشكل ملحوظ بين النساء الحوامل مقارنة بالضوابط غير الحامل امل مع وجود فرق ذي داللة إحصائية اللثة أعلى بين النساء الحوامل مقارنة بالمجموعة الضابطة غير الحو التهاب البالك ومؤشر الجرثومية الصفيحة كان مقياس (p<0.05) . ق النظافة أظهرت الدراسة الحالية زيادة في حالة التأكسد في اللعاب خالل فترة الحمل، التي يمكن أن تؤثر على صحة اللثة التي تأثرت أيضا عن طري استنتاج: الفموية. dropbox 11 baidaa 58-62.pdf simplify your life mudhar.docx j bagh college dentistry vol. 28(1), march 2016 the use of oral and maxillofacial surgery and periodontics 121 the uses of pedicled buccal pad of fat flap in reconstruction of intra oral defects mudher m. alsinibli, b.d.s, (1) adilalkhayat, b.d.s., m.med.sc.,f.d.s.r.c.s. (2) auday m. al-anee, b.d.s., f.i.b.m.s (3) abstract introduction: different surgical techniques used for closure of various oral defects. while each one of these techniques has its limitation; the buccal pad of fat used in last quarter of last century as pedicle or free graft in reconstruction of small to medium, congenital and acquired defects showed good potentials for success. the present study used the bpf as pedicled flap to reconstruct intra oral defects. the study aimed to evaluate of the success of buccal pad of fat pedicled flap in the reconstruction of intra oral defects. outlining its indications, limitations and complications. materials and methods: the study included 19 patients (17 males and 2 females) with age range between (170 years), all patients were treated with pedicled bpf for intra oral defects (8 pts. with oro-antral communications, 5pts. with maxillary alveolar bone defects, 4 pts. with cleft palate, and 2 pts. with carcinoma of buccal mucosa), under general or local anesthesia. follow-up period was for 3 months post-operatively, results:the results showed that 94.7% of patients had complete epithelization of flap and complete closure of the defect within 4-6 weeks. only 1 pt. 5.3% had total flap loss with very small size of the bpf. in postoperative period, 5.3% of pts. complained from pain, trismus, vestibular obliteration, partial flap loss, all disappeared gradually within 1 month from the reconstruction. conclusion:the bpf is reliable, easy, safe method to reconstruct small and medium size intra oral defects of maximum size 5x4x3 cm, in maxilla from upper canine region to the soft palate, and in buccal mucosa from retro molar area to the commissure of the mouth. key words: bpf, intra oral defects, reconstruction. (j bagh coll dentistry 2016; 28(1):121-126). introduction oral cavity contains different structures and organs developed from different embryonic origins; so each part has unique characteristics that potentially affect the expression and path of disease and the way it’s healed byyousuf et al. (1) many intra oral defects were seen by every dentist in general and by every oral and maxillofacial surgeon specifically. these may cause discomfort to patient or even continue morbid conditions. treatment for such defects seems to be annoying for both surgeons and patients with high rate of recurrence and failure(2). different surgical techniques used for closure of various oral defects. small fistulas following any surgical operation usually left to close spontaneously. fistulas with medium size either repaired with primary closure, local palatal flaps, vestibular and buccal advanced mucosal flaps, skin graft, allogenic graft that are associated with ischemia and recurrence. large fistulas are reconstructed with more complex operations by rotational flaps (regional), temporalis muscle flap, facial artery musculo-mucosal flaps and distant free flaps. these techniques being used are determined by the type of the defect and its size(3) (1)maxillofacial board candidate, chief resident of maxillofacial surgery department, al-shaheed ghazi al hariri hospital teaching centre, medical city, baghdad (2)assistant professor, department of oral and maxillofacial surgery, college of dentistry, baghdad university. (3)lecturer, department of oral and maxillofacial surgery, college of dentistry, baghdad university. while each one of these techniques has its limitation, the buccal pad of fat shows good potentials for success including that the buccal pad of fat is an axial flap with rich blood supply taking its supply from 3 arteries (facial, transverse facial and internal maxillary), and their anastomosing branches(4). another factor is due to its ease access to unique anatomical location as encapsulated mass fills the tissue space between masticatory muscles. the bpf has body and four processes that, its average weight is 10 g (8-12 g), average volume is 10 ml (8 -12ml), provides a 6x5x3 cm pedicled graft. bpf is larger and thicker in children and younger people and slightly thinner and smaller in older population. there is some relation between body weight and the size of buccal pad of fat but not distinct(5). buccal pad of fat used in last quarter of last century as pedicle or free graft; in reconstruction of small to medium ,congenital and acquired, soft tissue and bony defects, including oro-nasal and oro-antral communications following dental extraction, excision of oral mucosal lesions; benign or malignant, and primary or secondary closure of palatal cleft(6). material and methods the prospective of the current study included 19 patients (17 males and 2 females) with age range between (170 years) mean age was (35.5 years). four patients presented with cleft palate, 2 j bagh college dentistry vol. 28(1), march 2016 the use of oral and maxillofacial surgery and periodontics 122 patients with carcinoma in buccal mucosa, 5 patients with maxillary defect post excision of lesion, and 8 patients presented with chronic oroantral fistula/communication. follow up period was between january 2014 and february 2015. those patients attended to maxillofacial surgery department in alshaheedgazi al-hariri teaching hospital for surgical specialties and al-wasiti teaching hospital in baghdad, all of them treated surgically by pedicledbuccal pad of fat flap. four patients anesthetized with local anesthesia, 15 patients treated under general anesthesia. treatment protocol all patients were measured for their body mass index pre-operatively (except one patient; which the decision of using bpf wasmade after excision of the buccal mucosa lesion. so the mass and height of that patient was measured post operatively) and grouped into 5 categories. this new method, used to assess the relation between body mass and the relative size of bpf, was not done before in such specific manner. all patients were examined clinically for signs of infection by swab have been done for chronic defects. any turbid color with offensive smell considered as infection and managed preoperatively with antibiotics according to sensitivity for one week. nasal decongestant drops, imidazoline 0.1% (otrivine nasal drops) ®, were prescribed postoperatively for patients with oro-antral fistula/communication (two drops in each nostril, 3 times daily for one week). the duration of this study was for 13 months. patients were followed at 1, 2, 4, 8, and 12 week interval, with documentation of patient`s pre and postoperative data, and follow up results using special case sheet and photographs.informed consent was signed by every patient or their legal care persons. exclusion criteria 1) patients who received radiotherapy. 2) palatal defect in premaxilla, anterior to inter canine imaginary line. 3) those patients who previously lost the bpf either by trauma, accidental herniation during surgery, or used for another operation. 4) patients with medical problems who were unfit for general anesthesia. 5) local defect infection at the operation site, until overcome the infection. surgical techniques four approaches used to deliver the bpf in this study attributed to the location and the closeness of the defect to the bpf site in the following ways: chronic oro-antralcommunication\fistula first, irrigation of the defect with normal saline 0.9%, then refreshment of defect margins and excision of fistula when present was completed by blade no.15. crestal incision with blade no.15 from defect margins extended along the mucosa of adjacent teeth followed by identification parotid duct then vertical one or two incision(s) on attached gingiva and extended to buccal mucosa. curved mosquito hemostat inserted along the bone, under the flap, through muscles using blunt dissection; the mosquito hemostat inserted closed and withdrew wide open to create a tunnel that allow bpf to herniate through. after delivering of bpf, it sutured with 3/0 silk suture to the palatal side of the defect. mucoperiostealflap was returned to its position and secured with 3/0 silk suture with minimum tension. defect after excision of tumor of maxilla horizontal incision was made on buccal mucosa 1cm above the parotid duct and 1cm length, without flap reflection, blunt dissection done with mosquito hemostat using the same technique by inserting it closed and withdrew wide open to form tunnel through which the bpf herniate. cleft palate after bilateral fullthickness mucoperiosteal flaps were elevated, and the nasal and oral linings are closed in the midline; wide lateral raw bony surfaces and a lateral oro-antral perforation left. the bpf delivered through horizontal incision 5mm length just lateral andbehind to tuberosity, then adequate volume of the buccal fat pad flap was extruded to fill the gap over the exposed bone transposed into the lateral palatal region by gentle traction and sutured on each side by 3/0 vicryl absorbable suture. carcinoma of buccal mucosa there was no need for special incision to deliver bpf. bpf was delivered directly from the same defect that occurred after removal of the carcinoma of the buccal mucosa. blunt dissection carried out with mosquito hemostat through muscular layers of the cheek. results success criteria in this study were complete epithelization of the flap and the definite covering of the defect. table 1 shows the demography, j bagh college dentistry vol. 28(1), march 2016 the use of oral and maxillofacial surgery and periodontics 123 clinical information and complications for the patients at the end of follow-up period. nineteen patients (17 males and 2 females) were treated in this study. the minimum age was 1 year. the age range was 1-70 years with mean age of 35.5 years. the majority of patients were males, 17 (89%), while females were only 2 (10.5%). the distribution of patients according to their bmi (7) (table 2) was 5.25% in severely underweighted group, 10.5% underweighted, 36.8% normal, 31.5% over weighted, and 15.7% obese class i. the majority of defects reconstructed with bpf flap were of small size (> 5 cm2)73.75%, and only 26% of medium size (5-20 cm2), while no larger defect treated with this flap. figure 1 shows case with history of tumor in posterior alveolar bone of maxilla which was treated by excision of tumor and reconstruction of the defect with bpf at the same time, and the results through follow up period shown in a, b, c, and d sequentially. complications onlyone patient (5.25%) had complete flap loss, but several patients had different complications. pain: 26% of patients complained from mild to moderate pain on the 1st postoperative day. after one week only 5% had little discomfort that subsided before the 2nd week. dehiscence: 10% of patients complained from partial loss of flap from the anterior part of the defect, one of them had spontaneous closure within one month while the other had total loss of flap and recurrence of the same defect within one week. trismus: 26.3% of patients had trismus on 1st post-operative day, which percentage decreased to 15% within one week, only 5% (1 patient) continued limited mouth opening for all 3 months period which was present since a long time preoperatively. halitosis: 5% of patients had halitosis with bad oral hygiene, subsided within one month with active motivation about oral hygiene. sulcus obliteration: 21% of patients had vestibular sulcus obliteration, which return to normal size compared to adjacent area gradually in most of them, only 5% (1 patient) continued with obliterated vestibule throughout the follow up period. no patient had either bleeding intra or/and post operatively, or nasal or oral discharge, nor depression on cheek extra orally. table 1:shows the demography, clinical information, and complication of all the patients after the end of follow up period. age(yr.) sex defect type/cause bmi size of defect(cm) complication after 3 months 1 1 f cleft palate 20.4 0.7×2.5 2 2 m cleft palate 27 0.9×3 3 1.6 m cleft palate 24.69 1×2.3 4 13 m cleft palate 21.6 1.4×3 5 70 m c a buccal. mucosa 26.9 3.5×5 6 51 m c a buccal mucosa 25.7 3×4.6 trismus 7 19 m oaf 28.8 1.7×1.1 8 64 m oaf 20.44 0.9×1.3 9 15 m oac 18 1.3×1.5 total flap loss 10 44 m oaf 24.5 1×1.5 11 22 m oac 28.4 1.4×1.9 12 41 m oaf 31 0.8×0.9 13 52 m oaf 20.96 1.2×1.8 14 32 m oaf 29 0.8×1.1 15 8 m tumor post. alve. 15.4 1.5×2.1 16 16 m tumor post. palate 33.98 3×5 sulcus obliteration 17 58 m tumor post. alve. 19.1 2×3.4 18 36 m tumor post. alve. 30 1.3×2.2 19 10 f cyst excision 18 3×4.5 abbreviations: alve: alveolar bone. m: male. f: female. post: posterior. oac: oro-antral communication. oaf: oro-antral fistula. j bagh college dentistry vol. 28(1), march 2016 the use of oral and maxillofacial surgery and periodontics 124 figure1: a) tumor in upper left side of the palate and alveolar bone. b) defect 3.5cm ×5cm after excision of tumor. c) bpf sutured to the mucosa on the defect margins. d) 2 weeks post operatively table 2: relation between bmi, relative size of bpf and defect size bmi group no. of patients defect size relative size of bpf notes 15-16 severely underweight 1 small (≤5 cm 2) excess 16-18.5 underweight 2 1 patient with small defect 1.9 cm2 deficient very small bpf sutured under tension not enough to cover such small defect 1 patient with moderate defect excess 18.5-25 healthy weight 7 6 small excess 1 moderate excess 25-30 overweight 6 4 small excess 2 moderate adequate 30-35 class i obesity 3 2 small excess 1 moderate adequate discussion age:in our present study we evaluated the relative volumetric changes in various age groups. it was found that the bpf was relatively larger in 1st age group of patients (1-10 years) which disagreed with hining(8), who wrote about reconstruction of the facial contour deformity with the buccal fat pad flap, and stated that the fat pad is larger in the infant and the size decreases with age. we agree with xiao, et al(9),as they measured the volume of the buccal fat pad in theirstudy, which appeared to be a relatively constant anatomical structure throughout patient’s life. incision: it must be the smallest necessary to allow for delivering of bpf. larger incisions, cause an excessive exit of bfp lobules, which afterwards, interferes in the surgical field which agree with alkan et al.,(10) who stated that delivering of lager amount of bpf can cause hypertrophy and may need second operation forreduction.furthermore, the place of the incision is dependent on the anatomical closeness to the defect more than any other factors, such as surgeon’s preference. j bagh college dentistry vol. 28(1), march 2016 the use of oral and maxillofacial surgery and periodontics 125 the surgical technique is simple, and can be performed by different surgeons with different experiences. careful manipulation of the flap is of paramount, in order not to extrude the bpf. mechanical suction must be avoided once the bfp is exposed. further, blunt dissection, can be done with one or two mosquito hemostat, one to gently pull out the emergent part and the other to dissect the oral mucosa and muscle surrounding the bfp. we disagree with granizo. m. et al.,(11) because they mandated the use of two hemostats, while we used one hemostat in (68%) with no accounted difference. the capsule: in this study, the capsule of bpf was preserved in 73.68% of the patients and although we couldn’t preserve the thin capsule of bfp in 5 patients who had small to medium sized oral defects, complete epithelialization of bfp has occurred. it means that preservation of the capsule of the bpf is not crucial and it doesn't affect the end result of the procedure. this finding is not in agreement with baumann and ewers (12) as they stated that; it is very important to preserve the thin capsule of the bfp in order not to damage the small blood vessels. our findings agree with rapidis et al(13), ferrari et al., (14), and shrivastava, et al. (15); because they demonstrate that the size, tension and pedicle of the bfp were more important in the success of the procedure rather than preservation of the thin capsule, which partially provides its blood supply. suture:we think that types of suture material are not important as the tension on the margin of the flap. the sutures should be placed freely, to prevent tension necrosis of the flap. r. martingranizo(11) stated that the sutures should be tension-free, to avoid partial necrosis at the edges of the bpf flap. the largest defects covered in our study were a 5 x 3.5 cm maxillary defect and a 5 x 3 cm cheek mucosa defect. rapidis(13) reported that; in maxillary defects measuring more than 4x4x3 cm, the possibility of partial dehiscence of the flap was high due to the impaired vascularity of the stretched ends of the flap while in buccal or retro mandibular defects which measured up to 7x5x2 cm, reconstruction is accomplished due to the underlying rich vascular bed. relative volume of bpf: we didn’t see a close relation between body mass and the relative volume of the bpf even in very under weighted group (bmi=15 to 16) and in obese class i (moderately obese, bmi= 30 to 35) but it must be noted that the bmi less than 15(very severely underweight) and bmi more than 40 (obese class iii, very severely obese), didn’t present in our sample. egyedi(5) claimed that there is some relation between body mass and bpf but not distinct (10).in this study, patients have been categorized into 5 groups (table 2) to clarify the relationship between the total body weight and bpf and we found that the bpf size related to the size of the cheek (muscle of mastication) and not to the total body weight. the relative volume was just adequate in larger 3 defects (medium size defects), and excess in 15 small and medium defects. only in one patient (15 years old male) with small defect 13x15 mm (surface area 1.95 cm2)and his bmi was 18 (the under weighted category), the bpf was unexpectedly deficient. this boy already had hollow cheeks, so the deficient size of bpf may be due to his anatomical specifications (hollow cheeks). vestibular sulcus: 5.25% of patients in this study have been left with vestibular loss after three months follow up period. it seems due to the excision of pathology involved the alveolar bone and part of the palate rather than the bpf flap itself. ye et al (16) used the bpf in repairing maxillary oncological defects and gave the same explanation for vestibular loss. skin graft: we used skin graft to cover bpf on buccal mucosa of the cheek in the 1st patient in this study. the result was partial loss of skin graft, and epithelization has occurred after that. this finding agrees with granizo(11); because he found that no benefits of bpf use in combination with dermal grafts, which (skin graft) are lost, epithelizing afterwards by secondary healing. while the idea was totally opposite from 4 decades of last century; egyedi (5,10) used skin graft to cover the bpf. trismus and mouth opening: 26.25% of patients had trismus on 1st post-operative day,that percentage decreased to 15.8% within one week; only 5.2% (1 patient) had persistent limited mouth opening for all 3 months period. that patient was complaining from buccal mucosal carcinoma and excision of part of the muscles of the check has been done during operation. baumann (12,17)gave the idea that trismus is a common complication due to oral tumor ablation, more than the bpf itself, so it often occurs in the buccal membrane and retro molar area. in this study, one patient took radio therapy post operatively. no harm effect was seen on the viability of bpf pedicled flap used. this goes with weimin(16,18) when they implied that postoperative radiotherapy did not influence the reconstruction of maxillary defects with bpf. bfp used in this study in the reconstruction of different defect sizes in different locations, did not result in change of extra oral facial contour. alkan et al.,(10) stated in their clinical observations that j bagh college dentistry vol. 28(1), march 2016 the use of oral and maxillofacial surgery and periodontics 126 the bfp used in various sizes for the repairing of intra-oral defects did not produce any change in facial contour. nevertheless; amin, et al(19), reported one case with large oncological maxillary defect, more than 20cm2, complaining from hollowing of cheek, after repair with bpf. great care was given not to injure the buccal branch of facial nerve (examined by asking patents to blow their cheeks), nor to parotid duct (which examined clinically), which has been achieved by gentle blunt dissection, and leaving the bpf capsule intact whenever possible. these important structures usually run in close relation to the bpf capsule (20,21). zhang et al.,(22) stated that, the facial nerve and stenson duct are seldom injured when the bfp is bluntly dissected along its capsule. although the number of patients included in the present study was not enough for significant conclusions to be made,the bpf is reliable, easy, safe method to reconstruct small and medium size intra oral defects of maximum size 5x4x3 cm, in maxilla from upper canine region to the soft palate and in buccal mucosa from retro molar area to the commissure of the mouth. references 1. yousuf s, tubbs rs, wartmann ct, kapos t, cohengadol aa, loukas m. a review of the gross anatomy, functions, pathology, and clinical uses of the buccal fat pad.surgradiolanat 2010; 32: 427–36. 2. nanci a. embryology of the head, face and oral cavity. ten cates oral histology development, structure, and function, chapter 3:32-55 2008 3. ashtiani ak, fatemi mj, pooli ah, habibi m: closure of palatal fistula with buccal fat pad flap. int. j oral maxillofacsurg 2011; 40: 250–4 4. hudson jw, anderson jg, russell rm, anderson n, chambers k. use of pedicled fat pad graft as an adjunct in the reconstruction of palatal cleft defects. oral surg oral med oral radiolendod 1995; 80:24–7. 5. egyedi p. utilization of the buccal fat pad for closure of oro-antral and/or oro-nasal communications. j maxillofacsurg 1977; 5:241–4. 6. tideman h, bosanquet a, scott j. use of the buccal fat pad as a pedicled graft. j oral maxillofacsurg 1986; 44:435–40. 7. bmi classification. global database on body mass index. world health organization. 2006. retrieved july 27, 2012. 8. hening sm. reconstruction of the facial contour deformity with the buccal fat pad flap. ann plastsurg 1992; 29: 450-3 9. xiao h, bayramiçli m, jackson it. volumetric analysis of the buccal fat pad.eur j plastsurg1999; 22: 177-181 10. alkan a, dolanmaz d, uzun e, erdem e. the reconstruction of oral defects with buccal fat pad. swiss med wkly 2003; 133: 465-70. 11. martin-granizo r, naval l, costas a, goizueta c, rodriguez f, monje f, muiioz m, diaz f. use of buccal fat pad to repair intraoral defects: review of 30 cases. br j oral and maxillofacial surg 1997; 135: 814. 12. baumann a, ewers r. application of the buccal fat pad in oral reconstruction. j oral maxillofacsurg 2000; 58:389–92. 13. rapidis ad, alexandridis ca, eleftberiadis e, angelopoulos ap. the use of the buccal fat pad for reconstruction of oral defects: review of the literature and report of 15 cases. j oral maxillofacsurg 2000; 58:158-63. 14. ferrari s, ferri a, bianchi b, copelli c, magri as, sesenna e.a novel technique for cheek mucosa defect reconstruction using a pedicledbuccal fat pad and buccinatormyomucosal island flap. oral oncol 2009. 15. shrivastava g, padhiary s, pathak h, panda s, lenka s. buccal fat pad to repair intraoral defects. inter j scientific and research public 2013; 3: . 16. weimin ye, song y, ying b, et al. use of the buccal fat pad in the immediate reconstruction of palatal defects related to cancer surgery with postoperative radiation therapy. american association of oral and maxillofacial surgeons. j oral maxillofacsurg 2014; 72: 2613-20. 17. colella g, tartaro g, giudice a. the buccal fat pad in oral reconstruction. br assocplastsurg 2004; 57:3269. 18. chakrabarti j, tekriwal r, ganguli a, ghosh s, mishra pk. pedicledbuccal fat pad flap for intraoral malignant defects: a series of 29 cases. original article. indian j plastsurg 2009; 42:36-42. 19. amin m.a. bailey b.m.w. b. swinsona, h. witherowa, use of the buccal fat pad in the reconstruction and prosthetic rehabilitation of oncological maxillary defects. br j oral and maxillofacsurg2005; 43: 148-54. 20. loukas m. kapos t, louis rg jr, wartman c. ashley jones barry hallner gross anatomical, ct and mri analyses of the buccal fat pad with special emphasis on volumetric variations surgradiolanat2006; 28: 254–60. 21. hwang k, cho hj, battuvshin d, chung ih, hwang sh.interrelated buccal fat pad with facial buccal branches and parotid duct. j craniofacial surg 2005; 16. 22. zhang q, li l, tan w, chen l, gao n, bao c, application of unilateral pedicledbuccal fat pad for nasal membrane closure in the bilateral complete cleft palate. j oral maxillofacsurg 2010; 68: 2029-32. 15. hussein f.doc j bagh college dentistry vol. 25(1), march 2013 computed tomographic oral diagnosis 87 computed tomographic measurement of maxillary sinus volume and dimension in correlation to the age and gender (comparative study among individuals with dentate and edentulous maxilla) hussein haleem jasim, b.d.s. (1) jamal ali al-taei, b.d.s., m.sc. (2) abstract background : although development and progress in various diagnostic methods, but still identification of remnants of skeletal and decomposing parts of human is one of the most difficult skills in forensic medicine . gender and age estimation is also considering an important problem in the identification of unknown skull. the aims of study: to estimate volume and dimension of maxillary sinus in individuals with dentate and edentulous maxillae using ct scan, and to correlate the maxillary sinus volume in relation to gender and age. materials and methods : this study included 120 patients ranged from (40-69 years), divided into two groups, dentate group with fully dentate maxilla and edentulous group with complete edentulous maxilla, and each group composed of 60 patients (30 males and 30 females) who admitted to spiral ct scan unit in x-ray institute in baghdad to have ct of the brain and paranasal sinuses from october 2011 to june 2012, who had complaints of headaches or with suspection of sinusitis but without pathological findings in maxillary sinuses. the maxillary sinus volumes and dimensions (width, depth, and height) were measured with the help of the computer software in spiral ct scan system. results : the statistical analyses of maxillary sinus measurements for dentate and edentulous groups showed that the volume and dimensions of maxillary sinuses in both groups were larger in males than females and they tend to decrease with the older age, in addition it is found that there was no significant differences in measurements of maxillary sinuses between dentate and edentulous groups, but the exception was in height measurements which were significantly higher in edentulous than dentate group for both genders. conclusion: it's found that the volumes and dimensions of the maxillary sinuses were larger in males than in females, in addition to that they tend to be less with the older age, so the computed tomography measurements of maxillary sinuses may be useful to support gender and age determination in forensic medicine key words: computed tomography, maxillary sinus, volume, dimension, dentate individuals, edentulous individuals. (j bagh coll dentistry 2013; 25(1):87-93). introduction measurements of the maxillary sinuses in computerized tomography (ct) scans can be used for determination of age and gender when other methods are inconclusive (1) . determination of gender is extremely important as it can positively rule out a certain percentage of possibilities instantly. the skull, pelvis and femora are the most useful for radiological determination of gender. radiology can assist in giving accurate dimensions for which certain formulae can be applied to determine gender (2). age estimation is one of several indicators employed to establish identity in forensic cases. such estimations of living individuals are made for refugees or other persons who arrived in a country without acceptable identification papers and may require a verification of age, in order to be entitled to civil rights and / or social benefits in a modern society (3) . (1) master student, department of oral diagnosis, college of dentistry, baghdad university (2) assistant professor, department of oral diagnosis, college of dentistry, baghdad university pneumatization of the paranasal sinuses begin in the ethmoid sinus and continue sequentially in the maxillary sinuses, the sphenoidal sinuses, and finally the frontal sinuses (4) (figure 1). figure 1: diagram showed the development of the frontal and maxillary sinuses according to age in years. maxillary sinus volume and dimension the maxillary sinuses reach their mature sizes at the age of about 20 years, when the permanent teeth are fully developed. during adulthood, their j bagh college dentistry vol. 25(1), march 2013 computed tomographic oral diagnosis 88 shapes and sizes change especially due to loss of teeth. then after the maximum growth period, the volume of the maxillary sinus decrease in both genders. this may be caused by the loss of minerals in the bone matrix of the entire body structure that surrounds the maxillary sinus in all directions, which contracts the maxillary sinus and result in a decrease in the maxillary sinus volume (5,6,7) . smaller maxillary sinuses usually extend from the second premolars to the second molars, while larger sinuses extend from the first premolars or even from the canine and even beyond the third molars (8) . the relationship between maxillary sinus and edentulous maxilla after a prolonged period of being edentulous, the alveolar ridge that once supported the teeth become atrophic. extraction of posterior teeth cause an inferior expansion of the maxillary sinus ,thus proving the pneumatization phenomenon after tooth loss. pneumatization is a physiologic process that occur in all paranasal sinuses during the growth period ,causing them to increase in volume (9). pneumatization of the sinus varies greatly from person to person and even from side to side. the expansion of the sinus was larger following extraction of teeth enveloped by a superiorly curving sinus floor, extraction of several adjacent posterior teeth, and extraction of second molars in comparison with first molars (10,11) . (figure 2,3) some authors reported that after tooth loss, the periosteum of the schneiderian membrane shows increased osteoclastic activity, resulting in resorption of the sinus floor and consequent expansion of the maxillary sinus (12,13) . figure 2: coronal ct image showed pneumatization of the maxillary sinus into the palatal process of maxilla (arrows). figure 3: axial ct image showed pneumatization of the zygomatic process of maxilla (arrows). relationship between maxillary sinus and teeth the anatomical relation between the maxillary sinus and the teeth is a complex one, due to the variable extension of the sinus. identification of the distance between the dental roots apices and the sinus floor and the establishment of the available bone thickness are imperative requirements in case of surgical procedures of this area (14) . knowledge of the anatomical relationship between the maxillary sinus floor and the maxillary posterior teeth root tips is important for the preoperative treatment planning of maxillary posterior teeth (15) . and others found that the buccal roots of the second maxillary molar showed close relations with the sinus in 40.5% of their studied specimen (16) . while the roots of the maxillary first molar were close to the sinus floor in 60% of the studied specimens in addition, the smallest thickness of the alveolar sinus wall was in 1.7 mm at the level of the second molar (17) . the roots of the maxillary premolar, molar and occasionally canine may project into the maxillary sinus because of the implications this can have on surgical procedures, it is essential for clinicians to be aware of the exact relationship between the apical roots of the maxillary sinus because of the implications this can have on surgical procedures, it is essential for clinicians to be aware of the exact relationship between the apical roots of the maxillary teeth and the maxillary sinus floor (18,19) . subject, materials and methods a prospective study consist of (120) patients ranged from (40-69 years), divided into two groups, dentate group (fully dentate maxilla) and edentulous group (complete edentulous maxilla), and each group composed of 60 subjects (30 males and 30 females ) who admitted to spiral ct scan unit in x-ray institute in baghdad, from j bagh college dentistry vol. 25(1), march 2013 computed tomographic oral diagnosis 89 october 2011 to june 2012. patients selected with no history of trauma. patients with facial asymmetry or septal deviation or who had previously undergone surgical procedures or with cleft palate or ectopic & supernumerary teeth were excluded from the study. all patients were examined on spiral computed tomography scanner, (toshiba , aquillion 64) , scano angle 900, slice thickness = 1 mm measurement of maxillary sinus volume maxillary sinus volumes calculated by overlapping ct images (sections) on axial views. the volume of each section was : dv = ds × δh where (ds) is the area of the maxillary sinus in a given section which was calculated automatically by the software of ct machine and (δh) is the slice thickness of the section.( figure 4). the volume (v) of the region from the antral floor to a height of (n) mm was calculated as the sum of the volumes of each section (dv), so the total maxillary sinus volume on both sides from the antral floor to the top of the antrum also computed according uchida et al in 1998 as described below: v = (20) . figure 4: diagram of maxillary sinus showed the method used in this study for measuring maxillary sinus volume using ct images. measurement of maxillary sinus dimensions the three distances (height, width, and depth), were measured on the axial and coronal views, where the width and depth distances measured on axial views while the height distances measured on coronal views . the depth and width of maxillary sinus was measured above the most apical level of the maxillary sinus floor. the width was defined as the longest distance perpendicular from the medial wall of the sinus to the most lateral wall of the lateral process of the maxillary sinus in the axial view. the depth was defined as the longest distance from the most anterior point to the most posterior point of the medial wall in the axial wall. the height was measured away from the inner surface of the anterior border of maxillary sinus. the height of the maxillary sinus was defined as the longest distance from the lowest point of the sinus floor to the highest point of the sinus roof in the coronal view (21) . (figure 5,6). figure 5: showed ct image included in this study with width and depth measurements of maxillary sinus in this study (axial view). figure 6 showed ct image with height measurements of maxillary sinus in this study (coronal view). results regarding the dentate group, the mean values of the right and left maxillary sinus volume, width, depth and height were for males (23.98 ± 0.81), (23.9 ± 0.83) cm3; ( 24.07 ± 0.62), (24.67 ± 0.63) mm; (36.12 ± 0.62), (39.2 ± 0.61) mm; (39.68 ± 0.61), (39.50 ± 0.63) mm and for females (22.96 ± 0.44), (23.02 ± 0.46) cm3; (22.38 ± 0.95), (22.26 ± 0.94) mm; (35.0 ± 0.9), 35.14 ± 0.82 ) mm; (36.55 ± 1.26), (36.67 ± 1.06) mm respectively and if both sides are considered together, the mean values of the maxillary sinus volume, width, depth and height for males (23.94 ± 0.82) cm3, (24.37 ± 0.62) mm; (36.16 ± 0.61) mm, (39.59 ± 0.62) mm, while for females (22.99 ± 0.45) cm3, (22.32 ± 0.94) mm, (35.07 ± 0.86) mm, (36.61 ± 1.16) mm respectively. no significant difference between the right and left j bagh college dentistry vol. 25(1), march 2013 computed tomographic oral diagnosis 90 side for the four variables was found. from these results one can see that the maxillary sinuses in males were larger in volume and wider in width than that of females, as well as the depth and height are higher in males than that of females. regarding the edentulous group, the mean values of the right and left maxillary sinus volume, width, depth and height were for males were (24.05 ± 0.38), (23.99 ± 0.3) cm3; (24.87± 0.64), (24.75± 0.63 mm, (36.93 ± 0.53), (36.77 ± 0.51) mm ; (42.07 ± 1.38), (41.89 ± 01.21) mm, and for females (23.01 ± 0.75), (23.9 ± 0.77) cm3, (22.74 ± 1.04), (22.60 ± 0.93) mm; (35.15 ± 1.08) mm ; (37.26 ± 0.63), (37.18 ± 0.69) mm respectively . if both side are considered together, the mean values of volumes of the maxillary sinus for males (24.02 ± 0.34) cm3, (24.81 ± 0.63), (36.85 ± 0.52) mm, (41.98 ± 1.29) mm and for females (23.05 ± 0.76) cm3, (22.67 ± 0.98) mm, (35.1 ± 1.12) mm, (37.22 ± 0.66) mm respectively. also no significant difference between the right and left side for the four variables was found. from these results one can see that the maxillary sinuses in males were larger in volume and wider in width than that of females, as well as the depth and height are higher in males than that of females. (figure 7,8) . figure 7: age and gender differences of maxillary sinus measurements in dentate group figure 8: age and gender differences of maxillary sinus measurements in edentulous group comparison of maxillary sinus measurements between dentate and edentulous groups for both genders, the mean right and left maxillary sinus volume, width, depth showed no any significant differences between dentate and edentulous group, the exception was in height measurements which were significantly higher in edentulous than dentate group for both genders. but regarding age grouping, there were significant differences between age groups in both dentate and edentulous group, where these four variables tend to decrease with the older age in both dentate and edentulous group ( figure 9) . figure 9: gender differences between dentate and edentulous groups correlation between maxillary sinus volume and the three measured dimensions for both genders, the maxillary sinus volumes were positively correlated with the three measured dimensions for both sides (p<0.01) in dentate and edentulous group. if both genders considered together, the correlations with the width, depth and height in dentate were (r=0.76, 0.52, 0.64) respectively, while the correlations with the width, depth and height in edentulous group were (r = 0.88, 0.56, 0.86) respectively. (table 1): table 1: correlation between maxillary sinus volume and the three measured dimensions correlation coefficients in dentate group p value correlation coefficients in edentulous group p value width 0.76 0.0001 0.88 0.001 depth 0.52 0.0059 0.56 0.0067 height 0.64 0.0007 0.86 0.001 discussion maxillary sinus volumes and dimensions show a wide range in different studies that may reflect the influential effects like human variability and triggering of pneumatization. measurements of maxillary sinuses regarding both the dentate group and edentulous group, the mean values of the right and left maxillary sinus volume, width, depth and height showed no significant difference between j bagh college dentistry vol. 25(1), march 2013 computed tomographic oral diagnosis 91 the right and left side for the four variables if both side are considered together. also it is found that the maxillary sinuses in males were larger in volume and wider in width than that of females, as well as the depth and height are higher in males than that of females . previous studies found that there was a significant difference of the maxillary sinus volume between males and females, mainly due to the fact that male exhibit higher and wider maxillary sinuses than females, also they found neither significant difference between the left and right maxillary sinus volume that agree with this study (22). some authors have studied the volumetric measurements and anatomical variants of paranasal sinuses in twenty-four dried skulls of africans (nigerians) and they found that the average volume on the right was 11.59 ± 5.36 cm3and 14.98 ± 10.77cm3 on the left, asymmetry of the maxillary sinus was found in 100% of the dried skull, no bony septum was found within the sinuses, these results are too much less than that of this study, this might be due to using dried crania where no bony septum was found within the sinuses and also due to using of small sample, all these might be the cause for decreasing the readings (23) . others studied the maxillary sinuses in computerized tomography scans on turkish people and they found that the mean values of the right and let maxillary sinus width in males were (27.19±5.46mm), (26.89±5.52mm) and in females were (24.44±3.61mm) (24.27±3.98mm) respectively and the right and left maxillary sinus length (depth) in males (42.58±7.9mm), (43.7±7.78) and in females (37.8±5.69), (37.6±6mm) and the right an left maxillary sinus height in males were (47.6±6.4) mm, (47.2±6.5) mm and in females were (45.1±4.6), (43.6 ± 44) mm respectively, these results are higher than that of this study (24) . also some authors made measurements of the maxillary sinus volume using computed tomography and found that the mean volume ,width, anteroposterior length(depth), and height of the normal korean adult's maxillary sinuses were 21.90 cm3, 28.33 mm, 39.69 mm, 46.60 mm respectively, these results seem to be higher than that of this study except the volume which is slightly less than of this study that may be due to small sample size or due to anatomical variations, and also he found no significant difference between the right and left side for these variables, as well as he found that the maxillary sinuses in males tend to be larger than females which agree with this study (25) . association of maxillary sinus measurements with the age regarding age grouping, the four variables (volume, width, depth and height) showed significant difference among the three age group, where all of them found to decrease with the age in both dentate and edentulous group. some authors found that the volume decrease with the age which agree with this study, and they stated that this might be related to skeletal size and physique (26,27). others reported that the volumes of paranasal sinuses increase regularly with age in both genders, that disagree with current study (28). the comparison of maxillary sinus measurements between dentate and edentulous group regarding gender difference, the mean right and left maxillary sinus volume, width , and depth showed no significant differences between dentate and edentulous group except the measurements of height were significantly higher in edentulous group than that of dentate group. regarding age grouping, the mean right and left maxillary sinus mean of volume, width, depth and height showed significant differences between dentate and edentulous group. some authors studied (101) case and they found no significant difference in maxillary sinus dimension for dentate and edentulous subjects, and this agree with this study (29,30) . but others found that the maxillary sinus is significantly larger in adult patients who are edentulous in the posterior maxilla compared with patients with complete posterior dentition, also this disagree with this study (31) . correlation between maxillary sinus volume and the three measured dimensions if both genders considered together, the correlations with the width, depth and height in dentate were (r =0.76, 0.52, 0.64) respectively, while the correlations with the width, depth and height in edentulous group were ( r = 0.88, 0.56, 0.86) respectively. from these results one can see that the strongest correlation was with the width ( r = 0.88, 0.86) and height ( r == 0.86 ) in edentulous group , while the weakest correlation was with the depth in dentate group ( r = 0.52 ). in some studies found that in edentulous patients, the maxillary sinus may expand farther in height and continue to extend into the alveolar bone, this agree with this study, others reported that the height of maxillary sinus is the primary determinant of the volume of maxillary sinus, and the depth is the second most important variable, j bagh college dentistry vol. 25(1), march 2013 computed tomographic oral diagnosis 92 but this disagree with this study, where it is found that the most important and the strongest correlated variable with the volume was the width of maxillary sinus, and 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human maxillary sinus: a study using computed tomography. j dentomaxillofac radiol 1994; 23(3): 163-8. 31. harorh a, bacutoglu o: the compostion of vertical height and width of maxillay sinus by means of water’s view radiograms taken from dentate and edentulous cases. ann dent 1995; 54(1-2): 47-9. 63 effect of platelet rich-fibrin on alveolar osteitis incidence following surgical removal of impacted mandibular third molars: a comparative study ali s. abdul-kareem, b.d.s1 ali h. al-hussaini, b.d.s., m.sc.2 abstract background: postoperative morbidity after extraction of the impacted mandibular third molar (imtm) is inevitable. one of the most common postoperative complication is alveolar osteitis (ao) which is a painful non healed socket. many researches were attempted to prevent the occurrence of ao by introducing and applying a new materials inside the extraction socket. platelet rich fibrin (prf) is a biological complex fibrin matrix where autologous platelets and leucocytes are present, used to enhance tissue healing process and reduce the early adverse effects of the inflammation. aims: to evaluate the effect of prf on the incidence of ao. also to assess prf effect on pain, swelling, and trismus following the surgical removal of imtm and compare it with the control group. materials and methods: this clinical prospective study was conducted from october 2016 to october 2017 at the department of oral & maxillofacial surgery, college of dentistry/university of baghdad; and al-sadr specialized health center. a total number of 50 imtms were surgically removed from 45 patients who met the inclusion criteria (21 males and 24 females) with age ranged from 16-41 years. the cases were divided into two groups: a study group (25 cases) where prf were placed inside the extraction socket and control group (25 cases) where traditional surgery were performed. ao, trismus and swelling were assessed at the 2nd and 7th postoperative day. pain scored by numeric rating scale daily by the patients. results: the study showed that age, gender, side of impaction, oral hygiene condition, impacted tooth classification, surgical difficulty, and the time of procedure in both control and study groups had nearly similar distribution with non significant difference. at the 1st follow up period: trismus (p-value = 0.834) and swelling (p-value = 0.592) were non significant between the two groups. ao had overall incidence of 4% occurred only in the control group, while the prf group had no occurrence (0%), but the difference was statistically non significant. postoperative pain had no significance difference in both groups. at the 2nd follow up period there was no significant difference regarding trismus, swelling, and incidence of ao between both groups. conclusion: local application of prf can reduce the incidence of ao but not to a significant level. prf had no effect concerning postoperative pain, swelling, and trismus. keywords: platelet rich fibrin, alveolar osteitis, impacted mandibular third molar. (received: 15/1/2018; accepted: 30/2/2018) introduction impacted teeth are most frequently found among mandibular third molars and may lead to pericoronitis, periodontitis, damage to neighboring teeth, crowding of the anterior teeth, and temporomandibular symptoms. furthermore, the impacted teeth is a potential origin of odontogenic cysts and tumors. therefore, impacted mandibular third molars (imtms) are usually extracted [1]. new statistics submits that 72.2% of the world population has at least one impacted tooth (often lower third molar). pain, edema, trismus, bleeding and alveolar osteitis (ao) are the most common complications following the surgical extraction of impacted teeth. pain reaches peak levels of 6 to 12 hours and swelling 2 to 3 days postoperatively. trismus is a temporary muscle spasm and subside gradually after the surgery [2]. dry socket or ao is a common postoperative complication usually associated with the extraction of imtms and defines as an intense pain within and around socket of the extracted tooth, had an onset between the 1st and 3rd day after the extraction with a complete or partial blood clot disintegration [3]. it is interruption in healing process that disturb the conversion of the mature blood clot into granulation tissue [3]. several methods were used to control the immediate inflammatory response including secondary closure technique, window excision of the mucosa, use of drains, suture-less or single suture technique, administration of antibiotics, analgesic, corticosteroid, and by the application of low level laser therapy [4]. many researchers attempt to find a successful method for prevention of alveolar osteitis including local and systemic antibiotic, 1. master student, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. 2. assisstant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. 64 chlorhexidine rinse or gel, steroid, eugenol containing dressing, antifibrinolytic agent, low level laser therapy, biodegradable polymers, topical hemostatics, oxidized regenerated cellulose, and dextranomer granules [5]. platelet rich fibrin (prf) is a biological autologous material obtained simply by centrifugation of the patient’s own blood without anticoagulants. its fibrin matrix encompasses platelets and leukocytes as well as a variety of cytokines and growth factors, and it was presented to accelerate soft tissue healing [6]. the effect of prf on the postoperative inflammatory response (pain, swelling, and trismus) and on the ao incidence after its placement in the socket of surgically extracted imtms were evaluated in this research. materials and methods this clinical prospective study was conducted from october 2016 to october 2017 at the department of oral & maxillofacial surgery, college of dentistry/university of baghdad; and al-sadr specialized health center. a total number of imtms 50 teeth were allocated in two groups, study group (25 tooth) in which the impacted tooth was extracted and prf was immediately applied in the socket and control group (25 tooth) in which the impacted tooth was removed without application of prf. any patient age ≥15 who had unilateral or bilateral unerupted, partially, or fully imtms which indicated for surgical extraction were included in this study. the exclusion criteria was: 1. acute pericoronitis or imtm associated with pathologies. 2. smoker and pregnant patients. 3. medically compromised patients and patients who take chemotherapy or radiotherapy in the last year. preoperative assessment medical and dental history were documented and clinical examination (extraoral & intraoral) were performed for each patient. oral hygiene condition was assessed by the greene and vermillion method as mentioned by alkhadra [7], were scored as follow: ▪ good oral hygiene = 1 ▪ fair oral hygiene = 2 ▪ bad oral hygiene = 3 preoperative orthopantomography (opg) was taken for the patient to assess the location and configuration of impacted third molar, adjacent tooth, mandibular canal, and surrounding bone. the class and depth of the impacted tooth were documented according to pell and gregory’s classification. while angulation were classified according to quek, et al. (2003) method [8] by drawing lines to represent the intersected longitudinal axes of the second and third molars then measuring the angle formed between them: ▪ vertical impaction: 10° to 10°. ▪ mesioangular impaction: 11 ° to 79°. ▪ horizontal impaction: 80° to 100°. ▪ distoangular impaction: 11° to -79°. ▪ others: 101° to -80°. scoring the surgical difficulty the difficulty of extraction were divided into 3 categories: slightly difficult, moderately difficult, and very difficult according to pederson index [9] (table 1). table 1 pederson’s difficulty index. criteria value angulation mesioangular 1 horizontal 2 vertical 3 distoangular 4 depth of imtm position a 1 position b 2 position c 3 class of imtm class i 1 class ii 2 class iii 3 index = sum of angulation, depth, and class total slightly difficult 3 4 moderately difficult 5 6 very difficult 7 10 surgical procedure the patients was received information about the proposed surgical procedure and its risk, so they signed in an informed consent to proceed with the recommended treatment. the surgeries were performed under local anesthesia (3 65 cartridges of 2% lidocaine with 1:80,000 adrenaline) by the same operator. incision for horizontal mucoperiosteal flap was started just distolateral to the impacted tooth and continue buccally around the gingival margins till it reach the mesial side of the 2 nd molar where a vertical buccal releasing incision were performed (bayonet flap). the mucoperiosteal flap was reflected and the bone was removed to expose the cervical line of the tooth using round or fissure burs and a low speed/ high torque surgical straight handpiece. if required, the tooth was sectioned into pieces to facilitate delivery from the socket. after tooth removal, the socket was irrigated with 10 ml of normal saline then suturing with 3/0 black silk suture in control group. prf preparation and application in the study group, after intentionally making the tooth subluxated and before elevate it completely from the socket, blood aspiration to prepare the prf began. ten ml of autogenous venous blood was collected from an appropriate vein in the antecubital fossa. the obtained blood was immediately transferred to a plain 10 ml blood collecting tube and centrifuged at 3000 rounds per minute for 10 minutes. at the end of this process, the yellow shiny gelatinous part in the middle of the tube was the prf (fig.1). platelet poor plasma platelet rich fibrin red blood cells figure 1: layers after blood centrifugation using tweezers gently the prf were pulled out and placed in a sterile wet gauze mesh, scraping the bulk of rbc layer carefully by surgical scalpel leaving the buffy coat intact (fig. 2) figure 2: platelet-rich fibrin when the centrifuge rotation nearly reach its ending, the tooth or the root (if the crown was sectioned previously) was removed, the bone was smoothed /and the socket was irrigated with normal saline, place the prf gently inside the socket, then suturing the flap (fig. 3). the time of the operation was recorded from the incision to the end of suturing for each surgery. figure 3: platelet-rich fibrin inside the socket evaluation procedure four variables were evaluated in this study: mouth opening, swelling, pain, and the incidence of ao. the follow up took place in the 3rd and 8th days. the surgical operation day was considered as the 1st day. the following terms were used: t0 = the day of operation (preoperative). t1 = the second postoperative day. t2 = the seventh postoperative day. the degree of maximum mouth opening were recorded using a sliding caliber by measuring the distance from the incisal edges of the upper 66 left to the lower left central incisor as the mouth opened to its limit. the extent of the swelling was measured by swelling measurement device (smd). the idea was to measure the distance of the skin that will protrude postoperatively in 16 different points around the angle of the mandible in mm. smd consist of a modified disposable impression tray which could be detached and fixed easily to the device by a nuts and built-in bolts and a two perforated rectangular plates facing the angles of the mandible extraorally. each plate contain a 20 parallel holes (5 columns and 4 rows). these holes has a diameter that fit a calibrated straight cylinder bar (fig. 4). figure 4: swelling measurement device the technique of measurement was: making an impression for the upper teeth by modified disposable tray after checking its fitness in the patient mouth, removal of the tray from the patient’s mouth when the impression material was sat, fixing the tray to the smd. now, reinserting the smd with its fixed tray again in the patient’s mouth while the lower jaw in rest position for making the measurement. the upper impression work as a reference point for the smd and exactly take the same position any time it inserted inside the patient’s mouth. the distance between the inner surface of the perforated plate and the skin was recorded, this done by a calibrated straight cylinder bar which enter to the holes of the plate and move medially till it touch the skin, this process was repeated in a selected 16 holes in the plate. the mean measurement was calculated before the surgery at t0 as a baseline and similar measurements were carried out at t1 and t2 (fig. 5). figure 5: using the swelling measurement device at 1st follow up period. the pain was scored by the patient using numeric rating scale (nrs), where the number 0 represent no pain while number 10 represent the worst imaginable pain. the time to utilize the pain chart was determined by the operator at 10 pm and the patients were informed to restrict at that time daily for 7 days. the diagnosis of ao was done by an expert surgeon other than the operator to reduce the bias. the socket should had partial or complete blood clot loss and a pain score in nrs (≥ 6) in the extraction site at the time of checking to consider it as ao with or without foul odor. the patients were instructed to return if they experienced any persistent and progressive pain between follow-up visits. the cases of ao were treated by normal saline irrigation of the socket and packing it with alvogel® (india). antibiotic and analgesic were also prescribed. statistical analysis spss version 14.0 were used in order to analyze and assess the results of this study utilizing the following inferential data analysis: two independent-samples t-test, homogeneity of-variance, matched paired-samples t-test, and repeated measures analyzes groups of related dependent variables. results study sample comprised 45 patients (21 males & 24 females) aged 16-41 years with 50 imtms. 25 imtms regarded as control group and the remaining 25 imtms as study group. the results show that distribution of age, gender, side of impaction, oral hygiene condition, and the imtms classification (angulations, depths, and classes) between both groups were nearly similar and had non statistical significant difference. furthermore, the age group (20-24 years) and 67 parameter study mean (sd) control mean (sd) p value mouth opening t0 t1 49.9 (6.9) 39.5 (10.2) 50.7 (7.4) 39 (8.4) 0.697 ns 0.834 ns t2 46.5 (7.6) 47.4 (8.1) 0.710 ns swelling t0 t 34.8 (7.6) 32.9 (8.4) 34.7 (5.8) 31.6 (5.3) 0.972 ns 0.592 (mm) 1 ns t2 34.7 (7.9) 34.3 (5.7) 0.839 ns days study mean control mean p value day 1 5.88 5.16 0.380 ns day 2 3.92 4.08 0.843 ns day 3 3.12 2.56 0.445 ns day 4 1.76 1.96 0.676 ns day 5 1.68 1.32 0.476 ns day 6 1.40 1.08 0.584 ns day 7 0.64 0.72 0.809 ns n o . o f im t m s females accounted with the vast majority of attendance (40%) and (56%) respectively. also, mesioangular (52%) and position a (58%) had the higher prevalence in imtms classification while class i and class ii had equal distribution (48%). the results displayed that vast majority of the studied sample had a moderately difficult surgical extraction according to pederson index (fig. 6). 14 12 10 8 6 4 2 0 table 3: the mouth opening and swelling between both groups. (mm) slightly difficult moderately difficult very difficult sd: standard deviation. ns: non significant table 4: pain score between both groups using control study figure 6: distribution of impacted teeth according to pederson difficulty index adding to that no significant difference were found which indicate similar distribution of the surgical difficulties between the control and study groups. the mean time spent for surgical operation were listed in table (2) which had a nonsignificant difference between both groups. table 2: mean of surgical operation time. numeric rating scale. ns: non significant alveolar osteitis group mean (min.) sd se t-test t sig. the overall incidence of ao in this study was (4%) as shown by the results and were recognized control 36.52 13.47 2.69 study 44.76 21.14 4.23 -1.643 0.107 ns prf group, while no occurrence of ao were detected at t2 in both groups, in addition to that sd: standard deviation. se: standard error. ns: non significant trimus and swelling the degree of mouth opening and the extent of swelling were measured at t0, t1, and t2; however, there were no statistically significant differences between the groups (table 3). the amount of swelling were recorded by smd. pain the results display that studied samples had mostly a parallel behavior concerning pain parameter throughout 7 postoperative days as it scored by the patient daily using nrs, which reduced on passing of times. besides that, no significant differences were obtained between the study and control group at each days (table 4). no significant difference at each period were detected between the study and control groups (table 5). table 5: incidence of alveolar osteitis. t ao study control total p value t1 + 0 0% 2 8% 2 4% 0.245 ns 25 100% 23 92% 48 96% t2 + 0 0% 0 0% 0 0% 1.000 ns 25 100% 25 100% 50 100% t: times. ao: alveolar osteitis. (+) presence. (-) absence. ns: non significant discussion surgical removal of impacted mandibular third molars (imtms) are always associated with soft 68 and hard tissue trauma, so postoperative morbidity can’t be eliminated completely. surgeons in oral and maxillofacial continuously pursue a new materials or a modified surgical technique to improve outcomes. platelet-rich fibrin (prf) was utilized in various surgeries as a bioactive material which is obtained from the patient’s own blood to enhance soft and hard tissues healing. in the present study, the mean preoperative (t0) mouth opening in the control group was non-effectiveness of prf to reduce postoperative swelling into a significant level. in the present study, the pain was gradually reduced in a significant difference till 6th day in the control group, and to 5th day in the study group. in the remaining days the pain was decreased in a non-significant rate. in comparison of pain between the study samples, this study found no significant difference at 10 pm for each day. in accordance [17, 21, 22] 50.72±7.48 mm and in the prf group was to this, studies which evaluate the pain 49.92±6.96 mm (table 3). the p-value was 0.834 in t1 and 0.71 in t2 between both groups, and this showed that prf application had no effect regarding postoperative trismus. these finding is supported by other studies [11, 12] who concluded a non-significant difference regarding mouth opening postsurgically. other study in contrast had stated a significant difference on the 1st postoperative day [13]. the surgical extraction of imtms may cause limitation in mouth opening as a result of either inflammation involving the muscles of mastication or direct trauma to the tmj[14]. the etiology of trismus may be sited away from the local effect of the prf, so the muscles of mastication and the tmj located far from the local benefit of prf and its releasing factors. the maximum extent of swelling in the current study were observed at t1, and in comparison between both groups at t1 and t2 the result showed less amount of swelling in the study group at each periods but it doesn’t reach to a statistical significant level. in support to this result other clinical studies concluded a statistically no significant difference between study and control group [12, 15, 16, 17]. on the other hand, other clinical studies were reported a significant difference regarding swelling reduction in the prf group [13, 18]. three cytokines tnf-α, il-1, and il-6 play a major role in acute inflammation as they increase blood vessels permeability and this in turn increase the osmotic pressure of the interstitial fluid, the result is exudate edema [19]. prf had a high concentrations of anti inflammatory cytokines il-4, but also showed identical high serological concentrations of proinflammatory mediators, such as il-1β, il 6 and tnf-α [20]. this balance may explain the by visual analogue scale and showed a statistically non-significant differences between prf and non prf groups. however, in a bilaterally imtms study by kumar et al. (2016) recorded a significantly pain reduction in experimental group compare to the control [23]. this controversies in pain assessment may be belong to the patients’ pain tolerance kemp et al. (2012) concluded that visual analogue scale appears to be unreliable for obtaining objective information about the experiential dimensions of pain [24]. inflammatory mediators (e.g. bradykinin, histamine, 5-hydroxytryptamine) which are released after tissue injury have known as endogenous pain-inducing substances, which are able to sensitise or excite the peripheral terminals of nociceptive neurons and caused an inflammatory pain [25]. in our knowledge, no clinical study was reported that prf application prevent the releasing of pain inducing mediator after the surgery, and this may be the reason behind the uneffectivness of prf on the postoperative inflammatory pain. as shown by the result of this study, the total incidence of ao was 2 cases (4%) among 50 cases only occur at t1 in control group. the low incidence of ao may be attributed to the limited sample size and to the avoidance of some of ao risk factors such as, the operator performed the surgery with minimum trauma as possible, aseptic surgical field, exclusion of medically compromised and smoker patients, and no attendance of patients used oral contraceptives drug. supporting that, there is a relationship between elevated surgical difficulty and ao, since trauma causes delayed healing through compression of the thin compact alveolar bone of the socket, thrombosis in underlying vessels, reduced 69 tissue resistance that predisposes the wound to infection [26]. in the study group where the prf applied, there was no occurrence (0%) of ao compared to two cases in the control group, but it doesn’t reached to a statistical significant level between groups. this result come in agreement with asutay et al. (2016) who found in a clinical study a non-significant result between of prf and control groups [12]. in contrast, other clinical studies achieved a significant reduction of ao following the application prf with a ranges of incidence 0-2.6% in study group and 9.5-16% in control group [1, 27, 28]. the absence of the development of ao in the socket which were filled with prf may be accounted to the prf properties as reported by choukroun et al. (2006) who concluded that fibrin matrix of the prf guides the epithelial cells and fibroblasts migration and increase their metabolism when cover the injured tissues, also prf consider as biomaterial encouraging neovascularization, and it is a natural support to immunity [29]. this study concluded that local application of prf can reduce the incidence of ao but not to a significant level. prf had no effect concerning postoperative pain, swelling, and trismus. the limitation of this study were: small sample size and non-randomized method. references 1. he y, chen j, huang y, pan q, nie m. local application of platelet-rich fibrin during lower third molar extraction improves treatment outcomes. j oral maxillofac surg 2017; 75(12): 2497-2506. 2. kasapoğlu ç, brkić a, gürkan-köseoğlu b, koçak berberoğlu h. complications following surgery of impacted teeth and their management. in: mhk motamedi, ed., a textbook of advanced oral and maxillofacial surgery. rijeka: intech; 2013. p. 1-25. 3. tarakji b, saleh la, umair a, azzeghaiby sn, hanouneh s. systemic review of dry socket: aetiology, treatment, and prevention. j clin diagn res 2015; 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(. levene’s test( الثنائي، و ) t-test( المستقل، ) t-testنتفاخ. التحليل االحصائي تم باستخدام معامل التوافق، ) العملية. تمت عملية قياس االنتفاخ بجهاز قياس اال راسة كانت وعة الد الدراسة بان العمر، الجنس، جانب السن المطمور، حالة صحة ونظافة الفم، صعوبة الجراحة، ووقت انجاز العملية في المجموعة الضابطة ومجم أظهرت النتائج: لمريض يأخذ عقار منع الحمل الفموي في فترة متساوية تقريبا في االنتشار في كال المجموعتين بدون اهمية احصائية، مما يشير الى ان عينة البحث كانت قابلة للمقارنة. لم تسجل حالة 4اختالف ذو اهمية معنوية بين المجموعتين. نسبة حدوث التهاب مغرز السن في هذه الدراسة كان ( لم يحسب لهما p =0.592( واالنتفاخ )قيمة p =0.834 الفحص األولي: الضزز )قيمة الفحص الثانية لم يوجد اختالف يعتد به احصائيا% وحددت فقط في المجموعة الضابطة. االلم من اليوم االول ولغاية اليوم السابع لم يتغير تغير فعال احصائيا بين المجموعتين. في فترة مع المجموعة الضابطة. بخصوص الضزز، االنتفاخ، وااللتهاب مغرز السن. تقييم موقع القلع كشف عن افضلية بمنع تحلل خثرة الدم في مجموعة الدراسة عند مقارنتها ائيا. تحلل خثرة الدم تقل في موقع القلع بعد وضع الليفين الغني استعمال الليفين الغني بالصفيحات الدموية موضعيا يقلل حدوث التهاب مغرز السن ولكن بمستوى غير مهم احصاالستنتاج: بالصفيحات الدموية في مغرز السن. الليفين الغني بالصفيحات الدموية لم يكن فعال حيال االلم، االنتفاخ و الضزز بعد العملية. j bagh college dentistry vol. 26(1), march 2014 diagnosis and localization orthodontics, pedodontics and preventive dentistry 159 diagnosis and localization of the maxillary impacted canines by using dental multi-slice computed tomography 3d view and reconstructed panoramic 2d view nadia b. al-ansari, b.d.s. (1) nidhal h. ghaib, b.d.s., m.sc. (2) shifaa h. al-naimi, b.d.s., h.d.d., m.sc. (3) abstract background: diagnosis and treatment planning can be difficult with conventional radiographic methods as the orthodontic-surgical management of impacted canines requires accurate diagnosis and precise localization of the impacted canine and the surrounding structures. this study was aimed to localize and evaluate weather there is any differences in the diagnostic information provided by multi-slice computed tomography three dimensional volumetric ct images and two dimensional reconstructed panorama images (derived from ct) in subjects with impacted maxillary canines. materials and methods: thirty patients including 24 female and 6 male with mean age of 18 years with suspected unilaterally or bilaterally impacted maxillary canines were evaluated on images taken with brilliance™ 64, philips multi-detector computed tomography. the spatial relationships of the impacted maxillary canines relative to the adjacent structures was evaluated using linear and angular measurements, and the adjacent lateral incisor root resorption was assessed with three dimensional and two dimensional visualization software. results: the inclination of the impacted maxillary canine measured to the midline and to the occlusal plane did not differ significantly when it was evaluated using the two imaging modalities. however, there were significant differences between the 3d and 2d images with respect to the impacted maxillary canine vertical height, bucco-palatal localization, and in detecting the proximity and root resorption of the adjacent lateral incisors. conclusion: dental ct volumetric images provide more reliable and accurate information for diagnosing the maxillary impacted canine position, inclination, distance from adjacent structures, and detection of lateral incisors rootresorption. keyword: impacted maxillary canines, computerized tomography, root resorption. (j bagh coll dentistry 2014; 26(1):159-165). introduction maxillary canines contribute significantly to the esthetic and chewing functions, any disturbances in the eruption of permanent maxillary canines can cause problems in the dental arch and adjacent teeth, which require special care and attention.therefore, orthodontists should diagnose canine ectopic eruption early, trying to prevent retention of these teeth (1). the term “localization” means: “determination of the site or place of any process or lesion” (2). the identification of an impacted canine is only the first step in the proper diagnosis of such a case, after examining complicating factors such as pathologic findings and possible root resorption of the adjacent teeth, the orthodontist’s focus quickly turns to the localization of the impacted tooth, the correct diagnosis depends on clinic, radiographic and/or tomographic exams. besides, visualization of the correct location and orientation is essential for determining the proper course of treatment, which may consist of observation, extraction, or attempted alignment of the impacted tooth in conjunction with limited or comprehensive orthodontics (3). (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. (3)ministry of health, department of radiology, al-karkh general hospital. the conventional two-dimensional (2d) radiographic imaging was the most common modality used clinically as the primary diagnostic radiograph for the localization of impacted canines, treatment planning, and evaluation of the treatment result. panoramic radiography is a standard diagnostic tool in orthodontics for the preoperative diagnosis of routine cases. however, the diagnostic accuracy and validity for localizing impacted canines and adjacent structures can be underestimated due to deficiencies, such as distortion projection errors, blurred images, and complex maxillofacial structures that are projected onto a 2d plane, thus increasing the risk of misinterpretation (4,5). correct treatment planning requires accurate diagnosis and localization of the impacted canine in relation to the adjacent structures, assessing root resorption and the changes in root surface morphology, which normally requires threedimensional (3d) information, and the 3d ct overcomes the limitations of conventional radiography and found to be superior to the conventional 2d radiographs for the localization of impacted canines and in the assessment of incisor root resorption (6,7). also, it is outstanding for assessing the positions of the teeth and their mutual relationship compared to other diagnostic methods which gives a good basis for clinical considerations when complications occur during eruption j bagh college dentistry vol. 26(1), march 2014 diagnosis and localization orthodontics, pedodontics and preventive dentistry 160 (8), so several authors have therefore suggested that the use of computed tomography (ct) in such cases was more beneficial (9-11). the purpose of this study was toinvestigatethe location of the maxillary impacted canines; the contact; overlapping; and resorption severity of the neighboring incisors, and to compare and evaluate whether there is any differences in the diagnostic information provided by multi-slice computed tomography three dimensional ct images and two dimensional reconstructed panorama images in patients with impacted maxillarycanines. materials and methods the sample dental ct images were collected from 30 patients (24 females, 6 males) who were referred for localization of either unilateral or bilateralmaxillary impacted canines. a total of 36 maxillary impacted canines were studied, including 6 bilateral impactions, 17 left unilateralimpactions, and 7 right unilateral impactions. thepatients’ ages ranged from 16 to 20 years, with a mean age of 18 years, and were collected from al karkh general hospital/the computerized tomography department between january 2013 till june 2013. the following criteria were used in the selection of the total sample, according to the information taken from the clinical and radiographical examination of the patients: 1. they have full set of permanent dentition in both jaws “excluding the 3rd molar” , with unilaterally or bilaterally maxillary impacted canines. 2. patients should have no large metal restorations including crowns and fillings. 3. patients with no history of orthodontic treatment or orthognathic surgery. 4. no history of dento-facial deformities, pathologic lesions in the jaws or facial trauma. 5. no gross distortion of the dental arches due to acleft lip/palate. 6. good medical history, no hormonal disturbance. method for each patient in the sample a clinical examination and computerized tomographic imaging had been done using multidetector computed tomography (philips, brilliance 64,netherlands), then the ct images were collected from the workstation and the imaging data were reconstructed, analyzed, and stored in the ct acquisition workstation. the parameters included a tube voltage of 80 kv, a tube current of 30 ma, anda scanning time of 2.5 seconds.two different sets of images had been obtained for each patient, the first set consisted of 3d volumetric ct images and the second set consisted of 2d reconstructed panoramic images generated by the ct.software from the manufacturerallows for secondaryreconstructions to be produced that show manyviewpoints of the structures of interest. these secondaryreconstructions include transaxial, panoramic, and3d views. measurements were made on these views (distances and angles).this study focused on the following: 1type of impaction: the permanent maxillary canine location in relation to the adjacent teeth buccally, palatally, or in the line of the arch (midalveolus). 2width of the permanent maxillary canine crown (for both impacted one and normally erupted one), and both maxillary central incisors crown were measured in millimetersfrom the mesial contour of the crown to the distal contour on a line perpendicular to their long axis (12,13). 3linear measurements for accurate localization of the impacted canines to the maxilla structures, these measurements were based upon the methods described by walker et al. (14), in which two linear measurement were estimated: (a) canine horizontal distance to the midline; (b) canine vertical distance to the occlusal plane, both of them were measured in millimeters with the philips software on these views. figure 1: measurement of the canine horizontal distance to the midline 4degree of vertical eruption was estimated in both 3d and 2d views and the vertical zone of the impacted canine to the dental arch was categorized according to alqerban et al. (13) as coronal (cervical) one third of the root, middle one third of the root, apical one third of the root, and supraapical zone.5permanent maxillary canine angulations. two angles were measured of the inclination and for theaccurate localization of an impacted canine: (a) canine angulation tothe midline, which was formedby a line bisecting the midline of the jaws and a line through the canine cusp and the apex bisecting the long axis of the impacted j bagh college dentistry vol. 26(1), march 2014 diagnosis and localization orthodontics, pedodontics and preventive dentistry 161 canine and was graded according to walker et al. (14) and fleminget al. in 200915: grade i: 0-15º. grade ii: 16º -30º. grade iii: >= 30º.(b) canine angulation to the occlusal plane: the angles measured were formed by a line through the canine cusp and the apex bisecting the long axis of the impacted canine and the occlusal plane based upon methods described by walker et al.(15). figure 2: canine angulation to the occlusal plane. 6proximity of the impacted canine to the lateral incisors was examined by both 3d images (coronal, sagittal and axial views) and on 2d panorama image. this was measured as the shortest distance between the impacted canine and the incisor. contact was defined as proximity of less than 1 mm (16). 7canine overlap of the adjacent lateral incisor root: the mesiodistal position of the canine crown tip was assessed and graded upon the methods described by stivaros and mandall (17) as following: grade i: no horizontal overlap.grade ii: less than half the root width. grade iii: more than half, but less than the whole root width. grade iv: complete overlap of root width or more. 8severity of root resorption: the resorption defect of the adjacent lateral incisor was assessed by coronal, sagittal and axial 3d views and by 2d panorama view, and was rated based on the grading systems suggested by ericson et al. (16): no resorption: intact root surfaces. mild resorption: resorption extending up to half of the dentine thickness to the pulp. moderate resorption: resorption midway to the pulp or more with the pulp lining being intact. -severe resorption: the pulp is exposed by the resorption. figure 3: assessment of the incisor root resorption for assessment of location, reference lines werecreated that consisted of a horizontal occlusal plane line, and a vertical line bisecting the midline of the jaws. alldistances were measured perpendicularly from the referencelines to the cusp tip of the tooth, and the angles measured were the angles formed by the line bisectingthe long axis of the tooth and the reference line. the bucco-palatal localization of the impacted maxillary canine in the 2d panorama by using the ratio of the widest mesio-distal dimension of the impacted canine to the widest mesiodistal dimension of the ipsilateral central incisor which was defined as canine incisor index (cii) and were used in the cases of bilateral canine impaction, while in the cases of the unilateral canine impaction, the impacted canine location was determined by using the canine canine index (cci) which is defined as the ratio of the widest mesio-distal dimension of the impacted canine to the widest mesiodistal dimension of the normally erupted other side canine, the ratio of the widest mesiodistal dimension of the erupted canine to the widest mesiodistal dimension of the ipsilateral central incisor was defined as control canine incisor index (c-cii), when the mesio-distal width of the crown of an unerupted canine (as it appeared and measured directly on the reconstructed panorama) was 1.15 times larger (i.e. 15% greater) than that of the adjacent central incisor or contralateral canine then the canine was palatally displaced, otherwise it was considered to be labially located19, 20. statistical analysis all the data of the sample was subjected to computerized statistical analysis using spss version 17 for windows xp. the statistical analysis included: 1descriptive statistics: (mean, standard deviation, standard error, percentage, percentage of agreement, statistical tables). 2inferential statistics: (independent sample ttest, wilcoxon signed ranks test, chi-square test, the likelihood ratio, paired samples t-test: for intra and inter-examiner calibration). p (probability value) level of more than 0.05 was regarded as statistically non-significant.while j bagh college dentistry vol. 26(1), march 2014 diagnosis and localization orthodontics, pedodontics and preventive dentistry 162 a p-level of 0.05 or less was accepted as significant. results characteristic of patients a total of 36 impacted maxillary canines were studied in 30 patients, which includes 6 males (20%) and 24 females (80%); aged 16 to 20 (mean, 18) years. twenty four patients (80%) presented with unilateral impacted canines and 6 (20%) with bilateral impactions. among the 24 unilateral impacted canines, 7 (23.3%) were on the right and 17 (56.7%) were on the left side. impacted maxillary canine and central incisor mesiodistal width the mean value of the impacted maxillary canines mesiodistal width in the 3d ct (8.01± 0.59) was higher than its’ value in the 2d panorama (7.76 ± 0.69), with a significant difference between them. also, t-test was done to detect any differences in the mean values of the ipsilateral central incisor mesiodistal width between the 3d ct group and the direct clinical measurement, and there was no significant difference between them (p>0.05). while regarding the 2d panorama a highly significant difference was found between the direct clinical measurements and the 2d panorama in the ipsilateral central incisor mesiodistal width measurement (p≤ 0.001). 3d ct and 2d panorama localization of canines by distances impacted canine horizontal distance the statistical analysis showed that the horizontal distance of the impacted canine to the midline varied to a large extent in both the 3d ct group and the 2d panorama; in the 3d ct the mean value was (10.33 ± 5.15mm), while the 2d panorama showed a higher sd (7.01) and the mean value was (10.24 mm).wilcoxon signed ranks test showed no significant difference between them as (p>0.05). the maxillary impacted canine vertical position the descriptive analysis showed that the mean value of the impacted canines vertical height in the 3d ct were (10.12 ± 3.58mm), while the highest sd (5.53) were found in the 2d panorama with a mean value (11.83 mm). the wilcoxon signed ranks test revealed a significant difference between the 3d ct and 2d panorama (p≤0.05), as it was significantly higher in the 2d panorama group. yet, the vertical zones distribution of the impacted maxillary canines showed that the highest percentage of the canine impaction in both the 3d ct and the 2d panorama group was found in the apical zone followed by the middle zone, then by the cervical zone and the least percentage was found in the supra-apical zone with no significant difference (p>0.05) between both imaging modalities and the percentage of agreement was 47.22%. 3dct and 2d panorama localization of canines by angles the impacted maxillary canines angulation to the midline in general the majority of the impacted maxillary canines in both the 3d ct and 2d panorama were found in sector iii and ii respectively(in which the canine angulation was more than 16o), with statistically no significant difference between them. the impacted maxillary canines angulation to the occlusal plane when comparing the impacted maxillary canines angulation to the occlusal plane, it showed a higher mean value and s.d in the 3d ct (54.42˚± 20.09) than in the 2d panorama (49.88˚ ± 16.96).however, the wilcoxon signed ranks test revealed no significant differencebetween them. the impacted maxillary canine bucco-palatal position regarding the bucco-palatal impacted canine localization, the descriptive statistics demonstrates that in the 3d ct most of the impacted maxillary canines were found on the palatal and midalveolus side(41.7 %), and the least percentage were found on the buccal side(16.7%), while in the 2d panorama most of the impacted canines were found on the buccal side(63.9%), the least percentage were found on the palatal side(19.4%) and about 16.7% couldn’t be accurately localized.the chi-square analysis showed a highly significant difference (p ≤ 0.001) between the 3d ct and 2d panorama group and the percentage of agreement was 19.44%. moreover,there was significant correlation in the 3d ct between the impacted canine bucco-palatal and vertical position; as most of the buccally and mid-alveolus impacted canines were found in the cervical and apical zone, while most of the palatally located canines were found in the middle and apical zone respectively. the relationship between the impacted maxillary canines and the ipsilateral incisors the overlap relationship between the impacted maxillary canines and the ipsilateral incisors regarding the canine overlap relationship with the adjacent incisors in the 3d ct about 50% of the impacted canines lack the horizontal overlap with the adjacent incisors, while the reminder canines were ranging between overlap grade ii and iii respectively, and non of them reached to grade iv overlap; unlike the 2d panorama group canine horizontal overlap evaluation in which the highest percentage of the impacted canines scored grade iv overlap. the chi-square revealed a highly significant difference between both imaging modalij bagh college dentistry vol. 26(1), march 2014 diagnosis and localization orthodontics, pedodontics and preventive dentistry 163 ty and the percentage of agreement was 33.33% between them. the contact relationship between the impacted maxillary canines and the ipsilateral incisors in general the contact relationship were the same for both the 3d ct and 2d panorama; in which most of the impacted maxillary canines were contacting the adjacent lateral incisors, with no significant differences between them. root resorption of the adjacent lateral incisors. the statistical analysis as seen in the table (6) showed that the percentage of the lateral incisor root resorption within the 3d ct was nearly equally distributed between the no resorption and mild resorption grade, however the majority of the lateral incisors adjacent to the impacted canines in the 2d panorama showed no resorption grade. also, the inferential statistics demonstrated a highly significant difference in the detection of the presence or absence of root resorption of the adjacent lateral incisor between the 3d ct and 2d panorama as (p≤ 0.001).furthermore the statistical analysis showed highly significant correlation (p ≤ 0.001) between the incisor contact and it’s resorption in the ct group. discussion regarding the central incisor mesiodistal width measurement, there was no significant difference between the direct clinical measurement on the patient mouth and on 3d ct, which confirm that the 3d ct imaging allows greater accuracy and reliability for linear measurements which improved visualization of the anatomical situation of the impacted maxillary canines, these results are consistent with abdel-salam et al. (18) who stated that by ct the distances and angles in relation to adjacent structures could be measured in millimeters and degrees with very high accuracy. yet, thesignificant difference that were found in the central incisor mesiodistal width betweenthedirect clinical measurement and the 2d panorama measurement, and in the impacted maxillary canine mesiodistal width between the 3d ct and the 2d panoramaclarify the analysis limitations of the 2d panoramadue to the geometric distortion, superimposition of structures, rotational errors and linear projective transformation. linear and angular measurements are frequently used as comparative parameters for radiological assessment. they were utilized in this study due to their relative use as predictors of canine eruption, the high standard deviations of the horizontal distance which were found for both the 3d ct and 2d panorama indicates that maxillary canine impaction varies greatly, and there is no common mode of impaction these results are consistent with liu et al. (19). the difference foundin the mean vertical height between the 3d ct and 2d panorama could be due to the change in the cant of the occlusal plane during the reconstruction of the panorama, besides the inclination of the impacted canine relative to the vertical plane in the upper arch could effect its vertical height,the vertical level of the clinical crown have an influence on the estimated outcome of treatment; the higher the canine position with respect to the occlusal plane, the longer and more difficult the treatment (17). there was a general observation that the canine–midline angulations tended to be greater than 30˚ (grade iii) in both the 3d and 2d imaging modalities, it is worth mentioning that the canine angulation to the midline and the occlusal plane influences the treatment decision as a more horizontally positioned canine is considered more difficult to orthodontically align (17). in the current study the palatally and midalveouls impacted maxillary canine were more common than the buccal impactions which could be attributedto less referral of buccally impacted canines as they are usually palpable. also, this investigation showed a significant correlation in the 3d ct examination between the maxillary impacted canine bucco-palatal position and its’ vertical positionin which most of the buccally and the mid-alveolus impacted canines (50%) were found in the cervical zone of the adjacent lateral incisor, crowding here could be implicated as the main cause of buccal displacement of the maxillary canines. the remaining 50% of the buccally impacted canines were found in the apical zone which agrees with other previous studies (1921) .this might be due to that these canines have developed from ectopically located and buccally directed tooth buds, which places them in the genetic control area.regarding the palatally impacted canines the majority of them were found in the middle zone which supports the same result of chaushu et al. (21) and liu et al. (19). this could be explained by the possibility that environmental factors may give rise to palatal displacement of canines generated by genetic anomaly of the adjacent teeth (20). it is usually considered that the prognosis for orthodontically aligning an impacted permanent canine is worse if the crown overlaps more than half the adjacent incisor root (17). in the present study the 3d ct examination revealed that most of the impacted maxillary canines were found in sector i and ii which contradict the overlapping estimation result in the 2d panorama as a larger overlap was observedand most of the impacted canines were found in sector iv, due to the horij bagh college dentistry vol. 26(1), march 2014 diagnosis and localization orthodontics, pedodontics and preventive dentistry 164 zontal deformations that affects the reconstructed panorama, resulting in the decreased dispersion of objects in the horizontal plane. the number of the diagnosed resorbed roots of the adjacent laterals in the 3d ct was three times more than that diagnosed by the 2d panorama, which agrees with many previous studies (6,14,19). this significant difference is due to the ability of the 3d ct to overcomes the problems with conventional radiography and substantially increases the perceptibility of detecting root resorption by eliminating the overlap, distortion and increasing the image resolution, which has great significance in patient management as the diagnosis of the impacted canine accompanied by resorption of lateral incisor roots requires immediate separation of both teeth in order to stop resorption progression (13). the mechanism of root resorption following maleruption and the factors involved in the process are not clear. most authors have stressed the role of physical pressure due to the migration of the maxillary canine rather than mediation of resorption by swelling of the dental follicle (11, 14, 19), this theory is supported by the findings from the present study, in which the impacted canine was in contact (shortest distance less than 0.5 mm) with the lateral incisor in all of the resorption cases, indicating that incisor resorption was significantly correlated with contact between the impacted canine and the adjacent incisor. the mesial position of the canines may also influences the rate of incisor resorption, as it was observed that a more medial canine position was associated with a higher resorption rate. presently, the three dimensional dental ct is the most accurate method available to orthodontist for diagnosing the maxillary impacted canine position, inclination, distance from adjacent structures, impaction complications, and detection of lateral incisors root resorption which has a significant impact on diagnostic and therapeutic interventions. references 1park j, srisurapol t, tai k. impacted maxillary canines: diagnosis and management. dental ce today j 2012; 62-6. 2novak pd dorland’s illustrated medical dictionary. 27th ed. philadelphia: saunders; 2004. 3bishara se. impacted maxillary canines: a review. am j orthod dentofac orthop 1992; 101(2):159-71. 4elefteriadis j n, athanasiou a e. evaluation of impacted canines by means of computerized tomography. int j adult orthod orthognath surg 1996; 11: 257–64. 5stewart ja, heo g, glover ke, williamson pc, lam ew, major pw. factors that relate to treatment duration for patients with palatally impacted maxillary canines. am j orthod dentofac orthop 2001; 119: 216– 25. 6ericson s, kurol pj. resorption of incisors after ectopic eruption of maxillary canines: a ct study. angle orthod 2000; 70(6):415-23. 7heimisdottir k, bosshardt d, ruf s. can the severity of root resorption be accurately judged by means of radiographs? a case report with histology. am j orthod dentofac orthop 2005; 128:106-9. 8preda l, la fianza a, di maggio em, dore r, schifno mr, campani r, et al. the use of spiral computed tomography in the localization of impacted maxillary canines. j dentomaxillofac radiol 1997; 26: 236-41. 9peene p, lamoral y, plas h. resorption of the lateral maxillary incisor: assessment by ct. j comput assist tomogr 1990; 14:427–9. 10schmuth gp, freisfeld m, köster o, schüller h. the applicationofcomputerizedtomography (ct) in cases of impacted maxillary canines. eur j orthod 1992; 14(4): 296-301. 11ericson s, bjerklin k, falahat b. does the canine dental follicle cause resorption of permanent incisor roots? a computed tomographic study of erupting maxillary canines. angle orthod 2002; 72: 95–104. (ivsl). 12nagpal a, keerthilatha m, setty s, sharma g. localization of impacted maxillary canines using panoramic radiography. j oral sci 2009; 51(1): 37-45. 13alqerban a, jacobs r, fieuws s, willems g. comparison of two cone beam computed tomographic system versus panoramic imaging for localization of imparted maxillary canines and detection of root resorption. eur j orthod 2011; 33: 93-102. (ivsl). 14walker l, reyes enciso, james m. three-dimensional localization of maxillary canines with cone-beam computed tomography. am j orthod dentofac orthop 2005; 128: 418-23. 15fleming ps, scott p, heidari n, dibiase at. influence of radiographic position of ectopic canines on the duration of orthodontic treatment. angle orthod 2009; 79(3): 442-6. (ivsl). 16ericson s, bjerklin k, falahat b. does the canine dental follicle cause resorption of permanent incisor roots? a computed tomographic study of erupting maxillary canines. angle orthod 2002; 72: 95–104. 17stivaros n, mandall na. radiographic factors affecting the management of impacted upper permanent canines. j orthod 2000; 27: 169-173. 18abel-salam e, el-badrawy a, tawfik a. multidetector dental ct in evaluation of impacted maxillary canine. egypt j radiol nuclear 2012; 43: 527–34. 19liu d, zhang w, zhang z, wu y, ma x. localization of impacted maxillary canines and observation of adjacent incisor resorption with cone-beam computed tomography. oral surg oral med oral pathol oral radiol endod 2008; 105(1): 91-8. 20peck s, peck l, kataja m. the palatally displaced canine as a dental anomaly of genetic origin. angle orthod 1994; 64: 249–56. 21chaushu s, chaushu g, becker a. the use of panoramic radiographs to localize displaced maxillary canines. oral surg oral med oral pathol oral radiol endod 1999; 88(4): 511-6. j bagh college dentistry vol. 26(1), march 2014 diagnosis and localization orthodontics, pedodontics and preventive dentistry 165 table 1: impacted maxillary canine and central incisor mesiodistal width. variables descriptive statistics inferential statistic mean s.d. s.e. t-test p-value md 3 3d ct 8.01 0.59 0.10 2.23 0.033 * 2d panorama 7.76 0.69 0.12 md 1 direct clinical 8.41 0.76 0.13 -0.9 0.373 (ns) 3d ct 8.42 0.77 0.13 md 1 direct clinical 8.41 0.77 0.13 4.44 0.000 *** 2d panorama 7.43 1.33 0.22 table 2: impacted canine horizontal distance image type descriptive statistics comparison median mean s.d. s.e. wilcoxon signed ranks test p-value 3d ct 10.15 10.33 5.15 0.86 -1.25 0.212 (ns) 2d panorama 8.35 10.24 7.01 1.17 table 3: the mean of the vertical height of the impacted maxillary canines image type descriptive statistics comparison median mean s.d. s.e. wilcoxon signed ranks test p-value 3d ct 9.95 10.12 3.58 0.60 -2.47 0.014 * 2d panorama 10.95 11.83 5.53 0.92 table 4: bucco-palatal impacted canine position position descriptive analysis % of agreement comparison 3d ct 2d panorama likelihood ratio (d.f.=3) p-value no. percentage no. percentage buccal 6 16.7% 23 63.9% 19.44% 42.72 0.000 *** palatal 15 41.7% 7 19.4% mid-alveolus 15 41.7% 0 0% can not be determined 0 0% 6 16.7% table 5: impacted canine angulation with the midline position descriptive statistics % of agreement comparison 3d ct 2d panorama x2 (d.f.=3) p-value no. percentage no. percentage supra apical 3 8.3% 2 5.6% 47.22% 0.403 0.94 (ns) apical 12 33.3% 14 38.9% middle 11 30.6% 10 27.8% cervical 10 27.8% 10 27.8% table 6: incisor root resorption resorption grade descriptive analysis % of agreement comparison 3d ct 2d panorama likelihood ratio (d.f.=3) p-value no. percentage no. percentage no resorption 18 50.0% 33 91.7 % 47.22% 29.77 0.000 *** mild 17 47.2 % 0 0 % moderate 1 2.8 % 2 5.6 % severe 0 0 % 1 2.8 % khidair f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry120 evaluation of en-masse retraction using microimplant versus conventional techniques: an in vitro study ahmed g. mohammed sharif, b.d.s. (1) khidair a. al-jumaili, b.d.s., c.e.s., d.s.c.o. (2) abstract background: the study aimed to investigate the effect of different techniques of en masse retraction on the vertical and sagittal position, axial inclination, rate of space closure, and type of movement of maxillary central incisor. materials and methods: a typodont simulation system was used (cl ii division 2 malocclusion). three groups were used group 1(n=10, t-loop), group 2(n=10, time-saving loop), and group 3(n=10, microimplant). photographs were taken before and after retraction and measurements were made using autodesk autocad© software 2010. kruskalwallis one-way analyses of variance and mann-whitney u test (p≤0.05) were used. results: the rate of space closure showed no significant difference among the three groups (p≤0.05), while results regarding type of tooth movement showed a significant difference among the three groups (p≤0.05), where group 3(0.59±0.09) showed a more degree of controlled tipping than group1(0.33±0.19) while group 2(-0.50±0.09) showed an uncontrolled tipping movement. conclusions: it is concluded that microimplant anchored sliding mechanics gives better control over the en masse retraction mechanics and greater retraction. conventional techniques result in extrusion and move the teeth in less degree of translation movement. key words: microimplant, retraction, sliding mechanics, axial inclination. (j bagh coll dentistry 2013; 25(special issue 1):120-125). introduction during premolar extraction treatment, the orthodontist has several options for space closure, a popular method is en-masse space closure with sliding mechanics and coil springs. the use of loops for closing spaces in orthodontics requires the professional to know the force systems offered by the orthodontic treatment mechanics, because if the mechanics associated with loops are used improperly, complications such as loss of anchorage, excessive verticalization of incisors, increase of overbite, dental mobility, root resorption, and an increase in treatment time may result, with irreversible damage to the patient.(1,2)with increased use of preadjusted appliances, various forms of sliding mechanics have replaced closing loop arches. sliding mechanics might have great benefits, such as minimal wire-bending time and adequate space for activations.(3) the retraction of four incisors after canine retraction is accepted as a method to minimize the mesial movement of the posterior teeth segment, whereas en masse retraction of six anterior teeth may create anchorage problems. in addition, the tipping action built into anterior brackets in preadjusted appliances may produce problems of anchorage. these problems may be aided by the use of a transpalatal bar and extraoral appliances.(3,4) skeletal anchorage using dental implants provides an absolute anchorage for tooth movement. (1)master student. department of pop. college of dentistry. university of mosul. (2)professor. department of pop. college of dentistry. university of mosul. microimplants have many benefits such as ease of placement and removal and inexpensiveness. most importantly, because of their small size, they can be placed in the intraarch alveolar bone without discernable damage to tooth roots. in addition, orthodontic force applications can begin almost immediately after placement in contrast to dental implants.(5,6) in this study a typodont simulation system is used to show the possible effects of using variable factors on en masse retraction and rate of movement during space closure using microimplant and a conventional retraction technique. materials and methods a typodont simulation system (ormco, japan) is prepared according to manufacturer instructions to be used in the study with a wax form (maxillary arch cl ii division 2 malocclusion) and maxillary metallic teeth. initial alignment is made by finger pressure on 0.018" stainless steel archwireand preadjusted mini roth 0.022"x0.030" slot bracket after immersing the typodont in the water bath,(7) then ss 0.019"x0.025" archwire is used and end with ss 0.0215"x0.025" archwire. the posterior portion of the typodont wax is replaced by cold cure acrylic resin in order to stabilize anchorage teeth (second premolar, first and second molars) and provide a site for microimplant placement. wood table (length: 23cm, width: 10cm) with a custom made bases to receive and stabilize the typodont and the digital camera (figure 1). j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry121 the digital camera was fixed (10cm) from a vertical ruler which is fixed to the table opposite to the midline between central incisors when the typodont is in place. horizontal bar was fixed on the ruler and be coincided with a long axis bar (0.022" ss wire) that is fixed to right central incisor by making a groove from lingual fossa to the incisal edge (figure 2), this bar was placed in that groove and fixed with epoxy steel adhesive and adjusted to have the same axial inclination of the tooth. the point of intersection between horizontal and long axis bars is marked and used during repositioning of teeth after each experiment. autocad measurements a. photograph analysis: the standardized photographs were captured on a scale and transferred to the computer to be analyzed in autodesk autocad© software 2010 and to measure the accurate readings (figure 3).photograph analysis is made by drawing three lines: 1. the horizontal line is drawn over the horizontal bar. 2. the long axis line is drown over the long axis bar with a constant length (36mm) and locating the incisal edge (8.25mm) from the tip of long axis bar, the end of this line is considered the apex of the tooth and the estimated midpoint of the root is localized on this line (8.25mm) from tooth apex. 3. the vertical line is drown from the point of intersection between horizontal and vertical bars and extends down vertically. b. measurements: for each experiment of en masse retraction a photograph was taken before starting retraction process, while another photograph was taken after completing retraction process (i.e. after cooling of the typodont). the two photographs were analyzed by autocad software 2010 and measurements were made as follows: 1. sagittal movement of incisal edge: the distance from incisal edge to the vertical line was measured in each photograph, and the difference between the two distances will represent the sagittal movement of incisal edge and it is denoted by "se". 2. vertical movement of the incisal edge: the vertical distance from incisal edge to the horizontal line was measured in each photograph and the difference between the two distances will represent the change in vertical position of the incisal edge (7). positive values will indicate extrusion while negative values indicate intrusion of the tooth. 3. sagittal movement of tooth apex: the distance from tooth apex to the vertical line was measured in each photograph, and the difference between the two distances will represent the sagittal movement of tooth apex and it is denoted by "sa". 4. vertical movement of the estimated midpoint of the root: the vertical distance from (emp) of the root to the horizontal line was measured in each photograph, and the difference between the two distances will represent the vertical movement of (emp) of the root. the vertical change in the position of the (emp) of the root is used to determine the extent of true intrusion/extrusion (8). positive values will indicate true extrusion while negative values indicate true intrusion of the tooth. 5. axial inclination change: the angle between long axis line and the vertical line was measured in each photograph and the difference between the two angles will represent the axial inclination change. 6. rate of space closure: the distance between the distal wing of canine bracket and the mesial wing of second premolar bracket was measured in each photograph (9), and the difference between the two distances will represent the rate of space closure. 7. type of tooth movement: to determine and quantify the movement of the central incisor, the quotient of tooth apex movement (sa) and the incisal edge movement (se) were calculated. if the apical point moved in the opposite direction to the coronal point, the amount received a negative sign. tooth movements were classified on the basis of the quotient (r) obtained (sa/se): < 0, uncontrolled tipping; 0, controlled tipping; >0, controlled tipping and bodily movement; 1, bodily movement; and >1, root movement (10). reposition of typodont teeth after each experiment, typodont teeth was repositioned to their original position by immersing the typodont in the water bath and j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry122 placing an acrylic bite plane made from cold cure acrylic resin (figure4), a precise final alignment for the teeth was done, with ss rectangular archwire of size (0.019"x0.025"), then ss (0.0215"x0.025")(11), these archwires are ligated to typodont teeth with ss ligature. the criteria for successful repositioning of the teeth are passive insertion of ss rectangular archwire of size (0.0215"x0.025") in the bracket slots, the distance between the tip of long axis bar and the vertical bar is (5mm±0.1) measured by digital vernia, the distance between the incisal edge and the vertical bar is (7.6mm±0.1) measured by digital vernia, and the distance between the distal wing of canine bracket and the mesial wing of second premolar bracket is (13mm±0.1) measured by digital vernia. in order to avoid the possible alteration of the characteristics of the wax after successive experiments could interfere in the fidelity of the results, the wax was replaced for each experimental group (11). placement of microimplant the c-implant has two components, a titanium head and a screw. the screw is 1.8 mm in diameter and 8.5 mm long. the head has a 0.032" diameter hole and is connected to the screw by friction. a predrilling of implant site between second premolar and first molar buccally (8mm) from the base archwire (12-15) was made through the cold cure acrylic resin that support anchorage teeth then the microimplant is fixed in its place by a thin mix of cold cure acrylic resin and left to set for a few minutes before force application. experimental groups 1. in group 1 (n=10), en masse retraction with t-loop (t) (figure 5a), as the height is 7mm and the gingival horizontal part is 8mm and the width of the horizontal part is (2mm), archwire used is ss 0.018"×0.025".(16) 2. in group 2 (n=10), en masse retraction with time-saving closing loop (ts): this loop is made according to the inventor (17)of ss 0.018"x0.025" archwire (figure 5b). this loop is relatively wide (34mm), its height is fairly standard (78mm). each loop should be bent sufficiently distal to the canine bracket to allow proper oral hygiene. although the tieback used here is soldered to the wire, it can also be welded, crimped, or bent. once the space has closed enough that the tieback meets the molar bracket, the loop is squeezed with an optical or how pliers, moving the tieback forward and providing the space for further activation. 3. in group 3 (n=10), en masse retraction with microimplant (mi) and a crimpable hook was crimped on the ss 0.019"x0.025" archwire between lateral incisors and canines through which a force will be applied on the anterior teeth near the center of resistance of upper anterior segment, hook length used is (6mm) from the base archwire, then the force is applied through niti closed coil spring from the hook anteriorly to the microimplant posteriorly. (12, 14) statistical analysis statistical analysis was undertaken using the statistical package for social sciences (spss version 11.5) including descriptive statistics (table1). after examining the distribution of the sample, nonparametric tests were used including kruskal-wallis one-way analyses of variance (table 2) and mann-whitney u test (p≤0.05)(table 3)to compare means among the groups. results sagittal movement of the incisal edge: changes in sagittal position of incisal edge were group 1(1.7±0.22). group 2 (2.11±0.33). group 3 (2.84±0.31). group 3 shows a more degree of retraction than other groups with a significant difference among them (p≤0.05). vertical movement of incisal edge: changes in vertical position the tooth were group 1(0.54±0.24), group 2(1.29±0.21), group 3 (0.12±0.09). significant difference was recorded among the three groups (p≤0.05), where extrusion movement in group1 and 2 while intrusion in group 3. vertical movement of the estimated midpoint of the root: changes in vertical position of the emp were group 1 (0.19±0.18), group 2(0.60±0.19), group 3(-0.44±0.11). significant difference was recorded among the three groups (p≤0.05), where true extrusion movement in group1 and 2 while true intrusion in group 3. sagittal movement of tooth apex: changes in sagittal position of tooth apex were group 1(0.25±0.34), group 2(-0.97±0.47), group 3(1.81±0.29). significant difference was recorded among the three groups (p≤0.05), in group 2apex movement in opposite direction to that of the incisal edge, in group1 and 3 the apex moved in the same direction. axial inclination change: changes in axial inclination measurements were group 1(2.06◦±0.87◦), group 2 (7.35◦±0.94◦), group 3 j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry123 (1.84◦±0.65◦). significant difference was recorded in group 2(p≤0.05). rate of space closure: no significant difference was recorded among the three groups (p 0.05). type of tooth movement: the ratio of tooth movement were group1 (0.33±0.19), group 2 (-0.5±0.09),group3(0.59±0.09).significant difference was recorded among the three groups (p≤0.05). group 1 and 3 showed controlled tipping movement, while uncontrolled tipping movement was recorded in group2. discussion the upper incisors were retracted in group 1 and 3 with a combination of tipping and bodily movement. however, the upper incisor in group 2 moved in a relatively uncontrolled tipping manner and showed a resultant extrusion movement of the upper incisal edge.the reason of this observation may be attributed to the type of tooth movement achieved in each group. in group 1 there was a greater sagittal change of incisal edge (1.7mm) and least change in the root apex in sagittal direction (0.25mm), while in group 3 more degree of incisal edge and apex sagittal movement (2.84mm), (1.81mm) respectively, whereas group 2 the root apex moved in sagittal direction opposite to that of the incisal edge (-0.97mm). the reason behind the relatively greater movement of incisal edge in group 1 when compared with group 3 after retraction was mainly due to the wholesome tipping movement that took place around the root apex in group 1 and the translatory movement in group 3.(10; 18; 20) as the force application shifted towards the apex as in group 3, the force applied was more closer to the center of resistance, and the perpendicular distance between the level of force application and the center of resistance of the incisor was reduced resulting in the decrease of the magnitude of tipping moment generated during retraction, and resulting in the maintenance of the torque of the anterior teeth throughout the retraction period.(19) regarding axial inclination changegroup 3[1.84◦±0.65◦], group 1[2.06◦±0.87◦], and group 2[7.35◦±0.94◦], spaces present between the archwire and the bracket slot 0.019"×0.025" (group 3) and the 0.018"x0.025" (group 1 and 2) lead to a small loss of torque. in addition group 2, the central incisor moved in an uncontrolled tipping manner as a result of producing less m/f ratio than in group 1.(20; 21) upper incisor was intruded in group 3 and extruded in group 1 and 2 (0.21mm intrusion: 0.54mm, 1.29mm extrusion respectively), suggesting that the microimplant can demonstrate its ability to intrude the upper anterior teeth during retraction due to distal and intrusive force vector, which is in accordance with ma et al. this appears to be due to the direction of pull by the ni-ti closed coil spring from the microimplant head to the hooks on the archwire.(22) from table (1), it can be noticed that vertical position of central incisor is controlled by the change in both (ve) and (emp) of the root, {in group 1 and 2, nearly two thirds (ve) and one third (emp) of the root, while in group 3, nearly one fourth (ve) and three fourth (emp) of the root}. it is concluded that in group 1 and 2 the extrusion of the tooth is attributed to the (ev), while in group 3 the intrusion is attributed to the vertical change in (emp) of the root. the rate of space closure showed no significant difference among the three groups (p 0.05). this might be due to the effect of immobilization of posterior teeth which might move mesially in conventional retraction techniques. as a conclusion no significant difference existed in the rate of space closure among the three groups. microimplant achieved better control in both the anteroposterior and vertical directions during en masse retraction.retraction with time-saving closing loop results in the greatest extrusion, greatest change in axial inclination, and an uncontrolled tipping movement.the intrusion of central incisor with microimplant is mainly a true intrusion, while during retraction with t-loop or time-saving closing loop, tooth extrusion occurs mainly as a result of change in axial inclination of the tooth. references 1. begg pr. differential force in orthodontic treatment. am j orthod dentofacial orthop 1956; 42(7): 481510. 2. thiesen g, rego mvnn, menezes lm, shimizu rh. using different t-loops configurations to obtain optimized force systems. rev dent press ortod ortop facial 2006; 11(5): 57-77. 3. mclaughlin rp, bennett jc. the transition from standard edgewise to preadjusted appliance systems. j clin orthod 1989; 23: 142–153. 4. mclaughlin rp, bennett jc. anchorage control during leveling and aligning with a preadjusted appliance system. j clin orthod 1991; 25: 687–696. 5. deguchi t, takano-yamamoto t, kanomi r, hartsfield jk jr, roberts we, garetto lp. the use of small titanium screws for orthodontic anchorage. j dent res 2003; 82: 377–381. 6. park hs. the skeletal cortical anchorage using titanium microscrew implants. korean j orthod 1999; 29: 699–706. 7. soulaka aj. en masse retraction of maxillary anterior teeth using frictional and frictionless techniques (an in vitro comparative study). a master thesis, department j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry124 of pop, college of dentistry, university of mousl, 2007. 8. jürgen kinzel, petra aberschek, irene mischak, helmut droschl. study of the extent of torque, protrusion and intrusion of the incisors in the context of class ii, division 2 treatment in adults. j orofac orthop 2002; 63: 283–99. 9. dixon v, read mjf, o'brien kd, worthington hv, mandall na. a randomized clinical trial to compare three methods of orthodontic space closure. j orthod 2002; 29(1): 31-36. 10. madhur upadhyay, sumit yadav, sameer patil. miniimplant anchorage for en-masse retraction of maxillary anterior teeth: a clinical cephalometric study. am j orthod dentofac orthop 2008; 134(6): 803-10. 11. bisol, rocha. laboratorial study of the cuspid’s retraction timing and tipping effects during space closure, using the segmented arch technique, dental press j orthod 2010; 15(1): 53-64. 12. jae-hyun sung, hee-moon kyung, seong-min bae, hyo-sang park, oh-won kwon, james a. mcnamara, jr. microimplants in orthodontics. 1st ed. dentos inc. 2006, p. 63. 13. carlo marassi, cesar marassi: mini-implant assisted anterior retraction. dental press j orthod 2008; 13(5): 57-74. 14. hyo-sang park, tae-geon kwon. sliding mechanics with microscrew implant anchorage. angle orthod 2004; 74(5): 307-10. 15. sung-seo mo, seong-hun kim, sang-jin sung, kyurhim chung, youn-sic chun, yoon-ah kook, and gerald nelsong. factors controlling anterior torque during c-implant-dependent en-masse retraction without posterior appliances, am j orthod dentofac orthop 2011; 140: 72-80. 16. manhartsberg c, morton jy, burstone cj. space closure in adult patients using the segmented arch technique. angle orthod 1989; 59(3): 205-10. 17. shigeyuki matsui, yuichirou otsuka, satoru kobayashi, satomi ogawa, haruhide kanegae. timesaving closing loops for anterior retraction. j clin orthod 2002; 36(1): 38-41. 18. tominaga j, tanaka m, koga y, gonzales c, kobayashi m, yoshida n. optimal loading conditions for controlled movement of anterior teeth in sliding mechanics. angle orthod 2009; 79(6): 1102-7. 19. prabhuraj b kambalyal, arvind m, tarulatha r shyagali, rani hamsa. clinical evaluation of the effects of retraction forces applied at varying levels on maxillary anterior segment using implants. j advanced dental res 2010; (1): 27. 20. ah-young lee and young ho kim. comparison of movement of the upper dentition according to anchorage method: orthodontic mini-implant versus conventional anchorage reinforcement in class i malocclusion. international scholarly research network volume 2011, article id 321206. 21. manhartsberg c, morton jy, burstone cj. space closure in adult patients using the segmented arch technique. angle orthod 1989; 59(3): 205-10. 22. junqing ma, lin wang, weibing zhang, wenjing chen, chunyang zhao, and roger j smales. comparative evaluation of micro-implant and headgear anchorage used with a pre-adjusted appliance system. eur j orthod 2008; 30(3): 283–287. table 1: linear and angular changes in (group1, 2 and3) measurements. measurement group 1 group 2 group 3 mean sd mean sd mean sd se 1.7 0.22 2.11 0.33 2.84 0.31 ve 0.54 0.24 1.29 0.21 -0.12 0.09 emp 0.19 0.18 0.60 0.19 -0.44 0.11 sa 0.25 0.34 -0.97 0.47 1.81 0.29 i 2.06 0.87 7.35 0.94 1.84 0.65 sc 1.10 0.57 1.56 0.42 1.41 0.41 r 0.33 0.19 -0.50 0.09 0.59 0.09 table 2: kruskal-wallis analyses of variance se ve emp sa i sc r chi-square 19.992 25.876 24.586 25.061 19.559 4.254 23.118 df 2 2 2 2 2 2 2 asymp. sig. 0.000 0.000 0.000 0.000 0.000 0.119 0.000 table 3: mann-whitney u test. method se ve emp sa i sc r t ts 0.000 0.016 0.001 0.000 0.000 ns 0.000 mi 0.000 0.000 0.000 0.000 ns ns 0.001 ts t 0.000 0.016 0.001 0.000 0.000 ns 0.000 mi 0.000 0.001 0.000 0.000 0.000 ns 0.000 mi t 0.000 0.000 0.000 0.000 ns ns 0.000 ts 0.000 0.001 0.000 0.000 0.000 ns 0.000 ns: no significant difference at p ≤ 0.05 j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry125 figure 2: long axis bar on maxillary right central incisor. figure 1: wood table with the vertical and horizontal bars, custom made base for typodont and digital camera fixation. figure 4: acrylic bite plane figure 5: template used to make the loops operated by loop application version 1.7. a b figure 3: photograph analysis by autodesk autocad© software 2010: (1) line indicates tooth position before retraction, (2) axial inclination, (3) distance between top of long axis bar and vertical bar, (4) distance between incisal edge and vertical bar, (5) length of long axis bar, (6) distance from apex to emp of the root (white point), (7) distance between incisal edge and horizontal bar, (8) distance between emp and horizontal bar, (9) distance between apex and vertical bar. alhan f.doc j bagh college dentistry vol. 25(3), september 2013 periodontal health pedodontics, orthodontics and preventive dentistry121 periodontal health status in relation to physicochemical characteristics of saliva among pre-menopausal and postmenopausal women in baghdad city-iraq alhan a.qasim, b.d.s., m.sc. (1) abstract background: menopause can bring oral health problems and also associated with significant adverse changes in the orofacial complex. after menopause, women become more susceptible to periodontal disease due to deficiency of estrogen hormone. current study aimed to evaluate the periodontal health status in relation to salivary constituent including ph, flow rate and some elements (magnesium, calcium and inorganic phosphorus) of pre and post-menopause women. materials and methods: periodontal health status of 52 women aged 48-50 years old (26 pre-menopause and 26 post-menopause) were examined including (gingival index, plaque index, calculus index, probing pocket depth and clinical attachment level). salivary sample was collected for two women groups, ph and flow rate was recorded, and also biochemical analysis was assessed for some salivary elements include (magnesium, calcium and inorganic phosphorus). student's t-test was used for statistical analysis. results: salivary ph and flow rate of post-menopause women were found significantly lower than those of pre-menopause women, where as the mean of gingival index, probing pocket depth and attachment level indices significantly higher in post-menopause women. the level of salivary magnesium ion was significantly higher in pre-menopause women; also the level of calcium and inorganic phosphorus was lower in post-menopause women with non-significant difference. conclusions: this study has shown that the importance of preventive dentistry increases with aging in women. key words: menopause, periodontal disease, salivary elements. (j bagh coll dentistry 2013; 25(3):121-124). introduction females through certain stages in their reproductive life cycle, undergo alterations and fluctuating levels arise in the level of sex (steroid hormones) circulating in their blood stream, especially variation in the level of progesterone and estrogen in women may have direct and indirect effects on oral health in form of inflammation, gingivitis, periodontitis and altered microorganism (1,2). the menopause transition (climacteric, per-menopause) defined as the months and years surrounding the last menstrual period, is precipitated by fewer functioning follicles and ova, a consequent reduction in estrogen level and an inability to respond to pituitary gland. the initial sign of the transition, which may begin in the 40s, is a reduction in menstrual flow. this usually is followed by missed periods (3). however the menopause is defined as the permanent cessation of menstruation due to loss of ovarian follicular function, and usually takes place between 45 and 55 years of age (4). furthermore menopause is a physiological process which typically occurs in the fifth decade of life in women, and involves permanent cessation of menstruation. many physiological changes, most of which are due to decreased ovarian estrogen production, take place in women (1) lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. approaching the menopause (5), as well as in menopause, the decline in estrogen levels can lead to systemic bone loss.(6) so that after menopause, women become more susceptible to periodontal disease. the problem is due in large part to estrogen deficiency with resulting dental bone loss and inflammatory processes of periodontal tissue (7). metabolic changes that occur in postmenopausal women due to hormonal changes can also affect the salivary gland function and calcium and vitamin deficiency and various psychological factors during menopausal years (8, 9). they may complain of dry mouth because of decreased salivary secretion, as well as burning sensation of the mouth and tongue. taste sensation may change, causing a frequent complaint of metallic taste (10, 11). the topic of the effect of menopause on salivary secretion was studied only by a few studies. however the purpose of the present paper was to study the periodontal health status and physicochemical characteristics of saliva in premenopausal and postmenopausal women. materials and methods a case study was carried out in fifty two premenopause and post-menopause women aged 4850 years old include 26 pre-menopause and 26 postmenopause, visiting periodontics clinic college of dentistry/ university of baghdad. those having parathyroid and metabolic bone j bagh college dentistry vol. 25(3), september 2013 periodontal health pedodontics, orthodontics and preventive dentistry122 disease, cancer, or long term steroid therapy or taking contraceptive drug or other medication, also having early onset of menopause, having history of hysterectomy, having systemic diseases and smokers were excluded. questionnaires were filled for each patient, eliciting information on medical history, age at menopause, years since menopause. periodontal probe (william's probe) was used to measure the parameters which was used to assess the periodontal status includes (plaque index (pli) 12, gingival index (gi) 13, calculus index (cali) 14, probing pocket depth(ppd)15 and clinical attachment level (cal)16. stimulated saliva after chewing arabic gum for one minute was collected in a sterile screw capped bottle (17). salivary ph was measured using an electronic ph meter (pw 94, philips, england), and flow rate of saliva was expressed as milliliter per minute (ml / min). essential elements of saliva were analyzed at the poisoning consultation centre / specialized surgeries hospital. samples were centrifuged, the clear supernatant was separated by micropipette and was stored at (-20°c) in a deep freeze till being assessed. saliva level of calcium and magnesium were measured by flame atomic, using absorption spectrophotometer (buck scientific, 210vgp, usa). the inorganic phosphorus was determined calorimetrically by the molybdenum – vanadate method, a readymade kit (bio maghreb, tunisia) was used (18). the data was processed with spss 9.0 statistical software. mean and standard deviation were calculated. student's ttests was used to evaluate the significance of difference between different variables. the significance level was accepted at 95% (p<0.05). results the mean value of salivary ph, flow rate of post-menopause and pre-menopause group and statistical analysis using t-test are listed in table (1). table 1. salivary ph and flow rate among pre-menopause and post-menopause groups. sig. t-test ±sd mean variable .009 ** 2.74 0.12 5.81 post-menopause ph 0.13 6.29 premenopause .002 ** 3.21 0.05 1.76 post-menopause flow rate 0.07 2.05 pre menopause **highly significant (p<0.01), df=50 the data revealed that mean value of ph and flow rate were higher in pre-menopause than that of post-menopause group with highly significant difference. concerning periodontal parameter as shown in table (2), the mean value of gingival index, periodontal pocket depth and clinical attachment level of post-menopause group were statistically significantly higher than those of premenopause group, while there was no significant difference between the test groups in plaque index, although the calculus index was higher in post-menopause than pre-menopause group the difference was non-significant. table 2. periodontal parameters among pre – menopause and post-menopause groups sig t-test sd mean variable 0.753 -.316 0.087 1.271 post-menopause plaque index 0.060 1.305 pre-menopause 0.001** 3.645 0.058 1.542 post-menopause gingival index 0.045 1.275 pre-menopause 0.269 1.118 0.106 .627 post-menopause calculus index 0.052 .495 pre-menopause 0.006** 2.857 0.150 3.23 post-menopause pocket depth index 0.135 2.65 pre-menopause 0.027* 2.271 0.200 2.65 post-menopause clinical attachment level 0.208 2.00 pre-menopause *significant at(p<0.05),**highly significant at(p<0.01),df=50 the concentration of salivary magnesium, calcium and phosphorus ion in post-menopause and pre-menopause group was presented in table (3), the salivary magnesium (mg+2) concentration of pre-menopause was higher than postmenopause group with highly significant difference, also the concentration of salivary calcium (ca+2) and inorganic phosphorus was found lower in post-menopause group than other test groups, where as the difference was statistically not significant between both test groups. j bagh college dentistry vol. 25(3), september 2013 periodontal health pedodontics, orthodontics and preventive dentistry123 table 3. salivary elements among premenopause and post-menopause groups. sig t-test ±sd mean variable 0.000 ** -5.56 0.03 0.28 post-menopause mg 0.05 0.60 premenopause 0.307 -1.03 0.08 1.79 post-menopause ca 0.16 1.97 premenopause 0.211 -1.27 0.01 0.25 post-menopause p 0.01 0.27 premenopause df=50,* significant at p 0.05,** highly significant at p 0.01. discussion menopause is complete and permanent cessation of menstrual flow (amenorrhea), precipitate by fewer functioning follicles and ova and a consequent reduction in the estrogen level (19), which may cause periodontal disease following menopause as periodontitis and gingivitis, a prevalent oral diseases, have been connected to several systemic health changes (20). periodontitis leads to progressive and irreversible loss of bone and periodontal ligament attachment, as inflammation extends from the gingiva into adjacent bone and ligament (21), also menopause associated with significant adverse changes in the oro facial complex, in which women appear to experience an increase in oral symptoms that may result from endocrine disturbances (reduced estrogen) (22). the present study represented that the level of ph and flow rate of saliva was significantly lower in post-menopause than per-menopause this may lead to complain of post-menopause women from dry mouth because of decreased salivary secretion, as the female hormone estrogen influences many physiological and psychological function of oral discomforts such as burning sensations have long been reported to be strongly associated with the menopause (5, 23, 24). previous studies on the topic of the effect of menopause on salivary flow rate have revealed diverse results. a study has reported no change in salivary flow rate after menopause (25), while other studies have shown lower flow rates in postmenopausal women , as it is well known that salivary ph and flow rate play important roles in the oral mucosal defense (24,26). when the salivary flow rate is reduced, susceptibility to various oral diseases is enhanced, so that the periodontal parameters in the present study including, the gingival index, pocket depth and loss of attachment significantly was higher in post-menopause group as the menopause women has also been associated with destructive periodontal disease in older women (27). however, hormones have long been recognized as having some role in periodontal disease, so any change in sex hormones have long been considered to affect periodontal tissues and periodontal disease progression (28), as in menopause, estrogen levels decline rapidly, which can lead to systemic bone loss (6,29), this may explain why the difference of plaque index in pre and post-menopause group was non-significant. also the calculus index was found higher in post-menopause with no significant difference. the present study represented that the salivary constituents (magnesium, calcium, phosphorus) were lower in post-menopause group, as women appear to experience an increase in oral symptoms that may result from endocrine disturbances (reduced estrogen), calcium and vitamin deficiency and various psychological factors during menopausal years (5,26). the relative concentrations of the organic and inorganic salivary constituents are known to depend on salivary flow rate (30,31), because the salivary ph, and flow rate post-menopause decline may lead to decrease the level of minerals in saliva of post-menopause women, metabolic changes that occur in postmenopausal women due to hormonal changes can also affect the salivary gland function and salivary composition. in conclusion, the present study revealed that decreased ph, flow rate and oral hygiene might risk periodontal health of aged women. therefore, importance of preventive dentistry increases with aging in female subjects. references 1. amar s, chung km. influence of hormonal variation on the periodntioum in women. periodontology 2000 1994; 6: 79-87. 2. jeffecoat mk. osteoporosis: a possible modifying factor in oral bone loss. ann periodontal 1998; 3: 312-21. 3. frıedlander ah. the physiology, medical management and oral implications of menopause. j am dent assoc 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(ivsl). j bagh college dentistry vol. 32(1), march 2020 effect of dispensing 9 effect of dispensing method and curing modes on the microleakage of composite resins bahar jaafar selivany (1), muhand abduljabar khadim (2), dara hama saeed (3), abdulhaq abdulmajeed suliman (4) abstract background: vibration decreases the viscosity of composite, making it flow and readily fit the walls of the cavity. this study is initiated to see how this improved adaptation of the composite resin to the cavity walls will affect microleakage using different curing modes materials and methods: standard class v cavities were prepared on the buccal surface of sixty extracted premolars. teeth were randomly assigned into two groups (n=30) according to the composite condensation (vibration and conventional) technique, then subdivided into three subgroups (n=10) according to light curing modes (led-ramp, led-fast and halogen continuous modes). cavities were etched and bonded with single bond universal then restored with filtek® z350 (3m espe, usa). in the vibration group, condensation was done using compothixotm (kerr, switzerland). in the conventional group, condensation was done with hand plugger. curing modes for all groups were led-ramp, led-fast and halogen continuous modes, respectively. samples stored in distilled water at 37°c for seven days, and painted completely with two layers of nail varnish with only 1 mm around the composite restoration left. samples were thermocycled, immersed in 2% methylene blue solution for 3 hours, and sectioned longitudinally. dye penetration was assessed under a stereomicroscope. data were analyzed by kruskal-wallis and mann-whitney u tests with p <0.05 considered significant. results: vibration group showed less microleakage (p=0.028). in the conventional group there were no differences by using different curing modes (p=0.277). in the vibration group no differences were found between led-ramp and led-fast mode (p=0.989). however, there were significant differences between led-fast and halogen (p=0.05) and between led-ramp and halogen group (p=0.001). microleakage scores of all cervical walls were higher than the occlusal walls (p=0.001). occlusal walls leakage for conventional and vibration groups were not different (p=0.475), while there were significant differences between them at cervical walls (p=0.001). conclusion: vibration with led-ramp curing mode may decrease marginal leakage of composite restoration placed in standard class v tooth preparations. key-words: composite resin, vibration, condensation, compothixo, microleakage, (received: 19/12/2019; accepted: 20/1/2020) introduction composites resins are the most commonly used restorative material.(1,2,3) however, multiple clinical restrictions affect the widespread of this material.(1) the major constraints that affect the longevity of composite resin are polymerization shrinkage and stress-causing microcracks within the body of the filling which can be fractured easily and marginal gap leading to microleakage, bacterial invasion,(1,4,5) secondary caries, marginal staining, discoloration, tooth sensitivity, inflammation of the pulp, and loss of all or part of the restoration.(1,3,6-9) sonicfill system use sonic energy decreases the viscosity of the filling to about 87% which will improve the adaptability of the filling to the cavity walls. after stopping the sonic energy, the decreasing polymerization shrinkage and microleakage can be achieved by many (1) assistant professor, department of conservative dentistry, college of dentistry, university of duhok. (2) assistant lecturer, department of conservative dentistry, college of dentistry, university of duhok. (3) assistant professor, department of conservative dentistry, college of dentistry, hawler medical university. (4) professor, unit of restorative dentistry, college of dentistry, ajman university, uae. corresponding email, bahar.jaafar@uod.ac modifications in the composition of the filling materials, light curing mode and condensation procedures.(10,11,12) led light curing systems giving several benefits over traditional halogen curing units used in composite fillings in that they cure composite more rapidly, produce less heat, consistent output over time and more longevity. conventional halogen needs more curing times and their parts may be exhausted causing inadequate output and heat generation. (13-20) vibration lowers the viscosity of composite, and increases adaptation to tooth aiming in reducing microleakage. ultrasonic vibration of the uncured composite resin at room temperature increases flowability and improves cavity walls adaptation. different devices have been used to decrease composite viscosity, such as sonicfill® (kerr/kavo, usa) and compothixo™ (kerr dental, switzerland). composite returns to its normal viscosity and becomes suitable for contouring and carving.(21) compothixo™ is used to condense composite with vibration frequency. it is like a dental carver for composite. compothixo consists of four tip handle: pointed, spatula, plugger and semi-sphere tips. the button on the handle is used to activate j bagh college dentistry vol. 32(1), march 2020 effect of dispensing 10 the device, which must gently touch the composite materials.(22) the aim of this study was to determine the effect of composite placement technique namely vibration using compothiox (kerr) plugger as compared to conventional hand plugger condensation on the microleakge of composite restoration placed in class v tooth preparation that cured using three different curing modes (ledramp, led-fast and halogen continuous). materials and methods sixty non-carious human premolars freshly extracted for orthodontic purpose were collected and stored in 0.2% thymol solution at room temperature until used. the routine prophylactic procedure was carried out with a rubber cup and pumice slurry for all teeth. all teeth with cracks, fracture or pigmentation were excluded. standard class v cavities were prepared on the buccal surface of all 60 premolars, using #245 carbide burs (d-flex, germany, ce8120) using a high-speed hand-piece with a copious amount of water coolant. bur was changed after each cavity preparation. dimensions of the cavity preparation were kept approximately to mesio-distal width of 3 mm, occluso-gingival height of 2 mm and pulpal depth of 2 mm by using a small ruler. all cavity margins were kept in enamel. williams periodontal probe was used for checking the measurements. to decrease the errors only one operator prepared all teeth.(4,23,24,25) the teeth were then randomly classified into two main groups according to the condensation protocol to be used; vibration and conventional (n=30 each). those two groups further divided into three subgroups (n=10 each) according to light curing modes; led-ramp mode, led-fast mode and halogen in continuous mode. the cavities were treated with 37% phosphoric acid (denfiltm etchant-37, korea) for 15 seconds, rinsed for 15 seconds with distilled water, then gently dried for 5 seconds. single bond universal (3m espe) was applied using a disposable clean brush by painting the prepared cavity for 10 seconds, gently dried, then cured for 20 seconds. all groups were filled with the composite material (filtektm z350, 3m espe) according to the manufacturer’s instructions. the material was inserted in one increment and cured. in the vibration group, condensation of the composite was performed using compothixotm plugger tip (number 5405, kerr), while in the conventional group the condensation was performed using conventional hand plugger (smic s.s.2). for the led curing light (mini led acteon, france) the intensity, as measured by a light meter, was 1250 mw/cm2, while that for the halogen light (coxo-dental halogen curing unit cbc-682) was 1500 mw/cm2. for all modes (led-fast, led-ramp and halogen continuous) the curing time was 40 seconds following the manufacturer’s instructions. the restorations were finished with fine and extra-fine finishing diamond burs (diatech dental ag, heerbrugg, switzerland) used in a highspeed handpiece under constant air/water coolant and polished with sequential aluminium oxide discs. all restored teeth were stored in 37°c distilled water for 1 week using an incubator. (2,14) thermocycling was done to simulate the temperature changes that take place in the oral cavity that might result in changes in the micro space between the tooth and the restoration. the procedure was done by cycling the teeth between two water baths: one bath maintained at 5⁰c (±0.5°c) and the other at 55⁰c (±0.5⁰c), with a dwell time of 15 seconds. the number of cycles was 500 cycles according to the international organization for standardization. the apices of the roots were sealed with wax and then the teeth were covered with two coats of nail varnish except for 1 mm around the margins of the restoration. this is a well-known standardized procedure for leakage studies. nail polish was painted all over the tooth after sealing any tooth opening. teeth were immersed in 2% methylene blue solution for 3 hours. (https://www.ncbi.nlm.nih.gov/pmc/articles/pm c4963767/) the teeth were longitudinally sectioned using microtome (minitome, struers, copenhagen, denmark) (figure 1). for each tooth, there were two readings, one for each half (n=20). dye penetration was assessed under a stereomicroscope (10x). dye penetration was scored for both enamel and dentin margins on a scale from 0 to 4.(26) score 0= no microleakage. score 1= dye penetration within 1/3 of cavity wall. score 2= dye penetration within 2/3 of cavity wall. score 3= dye penetration within the last 1/3 of cavity wall up to the axial wall. score 4= dye penetration spreading along the axial wall. https://www.ncbi.nlm.nih.gov/pmc/articles/pmc4963767/ https://www.ncbi.nlm.nih.gov/pmc/articles/pmc4963767/ j bagh college dentistry vol. 32(1), march 2020 effect of dispensing 11 figure 1: minitome, struers, copenhagen, denmark. multiple group comparisons were performed using the nonparametric kruskal-wallis test. the p value between different test groups was calculated by using the mann-whitney test with bonferroni correction. p value of less than 0.05 indicated a significant difference. in this study we assigned a score for different extends of leakage, therefore, it is not a parametric test since there was no actual numerical measurement. results data analysis showed that there were statistically significant differences between two main groups, with less microleakage in vibration group (table 1). table 1: distribution of the overall microleakage scores of the conventional method compared to that of vibration method. microleakage score conventional hand plugger (n= 60) vibration using compothiox (n= 60) 0 0 13 1 38 30 2 19 15 3 3 2 p value 0.028* * using mann whitney test. the microleakage score of each curing mode by vibration technique was compared with the microleakage score of the same mode by conventional technique. using led-ramp curing mode resulted in highly significant less microleakge when it was combined with vibration condensation technique (p<0.001), while the leakage was not significantly different in both placement techniques when the composite was cured with led-fast (p=0.171) and halogen light curing units (p=0.358) (table 2). table 2: microleakage scores of each curing mode by the two condensation methods. microleakage score vibration# conventional$ vibration convent. vibration conventional led-ramp (n=20) led-ramp (n=20) led-fast (n=20) led-fast (n=20) halogen (n=20) halogen (n=20) 0 4 0 7 0 2 0 1 15 14 8 14 7 10 2 1 3 4 6 10 10 3 0 3 1 0 1 0 p value < 0.001* 0.171* 0.358* * using mann whitney test. # vibration: using compothixo plugger for composite condensation. $ conventional: using hand plugger for composite condensation. another comparison between the microleakage score performed, between the different light curing modes for each condensation technique. using the kruskal-wallis test there was a significant difference in the microleakage score between the light curing mode by using the vibration technique (p=0.011). using mann whitney test the result showed that there was a significant difference in the microleakage score between led-fast and halogen curing mode (p=0.05). and there was highly significant difference between led-ramp and halogen curing mode (p=0.001). the difference in the microleakage score between led-ramp and led-fast was not significant (p=0.989) (table 3). the difference in the microleakage score by using conventional technique was not significant between the three-curing mode (p=0.277) (table 3). j bagh college dentistry vol. 32(1), march 2020 effect of dispensing 12 table 3: microleakage scores of vibration and conventional condensation methods using three light curing methods. microleakage score vibration# method conventional$ method led-ramp (n=20) led-fast (n=20) halogen (n=20) led-ramp (n=20) led-fast (n=20) halogen (n=20) 0 4 7 2 0 0 0 1 15 8 7 14 14 10 2 1 4 10 3 6 10 3 0 1 1 3 0 0 p value 0.011*† 0.277* * using kruskal-wallis test. † using mann whitney test: led-ramp compared to led-fast (p=0.989); led-ramp compared to halogen (p=0.001), led-fast compared to halogen (p=0.05). # vibration: using compothixo plugger for composite condensation. $ conventional: using hand plugger for composite condensation. another comparison found that the difference in the microleakage scores between the cervical walls and occlusal walls was highly significant regardless of the condensation techniques and light curing mode, p<0.001 (table 4). the microleakage scores of the cervical walls were compared between conventional and vibration techniques, in which the difference was highly significant (p<0.001). in comparison with the occlusal walls between the two condensation techniques, the difference was statistically nonsignificant (p=0.475) (table 5). table 4: microleakage scores of all cervical walls compared to that of all occlusal walls. microleakage score cervical (n=120) occlusal (n=120) 0 23 88 1 31 26 2 41 3 3 12 0 4 13 3 p value < 0.001* * using mann whitney test. table 5: microleakage scores of the cervical walls compared to that of occlusal walls, by condensation method. microleakage score cervical occlusal conventional $ (n=60) vibration # (n=60) convention al (n=60) vibration (n=60) 0 0 23 45 43 1 17 14 15 11 2 30 11 0 3 3 7 5 0 0 4 6 7 0 3 p value <0.001* 0.475* * using mann whitney test. # vibration: using compothixo plugger for composite condensation. $ conventional: using hand plugger for composite condensation. discussion the longevity of the restoration is greatly affected by marginal seal integrity.(16) this integrity is affected by the microleakage that occurs due to polymerization shrinkage which is the main cause of composite restoration failure.(9) one way to minimize the polymerization shrinkage is to allow the flow of resin composite during setting by means of controlled polymerization. this flow might be enhanced using vibration during composite placement such as using the compothixo plugger to facilitate the material flow and adaptation to the walls of the cavity. this study assessed the composite microleakage using two different condensation techniques j bagh college dentistry vol. 32(1), march 2020 effect of dispensing 13 (conventional and vibration) for composite placement and using different light curing modes in an attempt to promote the longevity of the composite restorations. all cavities had the same dimensions to overcome the effect of configuration factor (c-factor).(27) all cavity preparations and restorations were performed by the same operator to surpass multiple operator’s errors as some researches recommended. (25) it is obvious from table (1) that the placement of composite using vibration showed significantly lower microleakage scores when compared to conventional hand plugger condensation. this could be explained by the fact that vibration decreases the viscosity of the material and facilitates its flow within the prepared cavity with better adaptation.(22) regarding the effect of light curing mode and the two condensation methods, there were highly significant differences between led ramp groups with the least scores in the vibration group (table.2). this finding could be explained by the fact that pre-polymerization at lower light curing intensity followed by final cure at high power intensity leads to improved flow of molecules in the material, decreasing the polymerization shrinkage stress in a restoration.(28) therefore, the led-ramp group was expected to produce better marginal integrity and sealing especially when used with vibration which also enhances the flow of material and better marginal adaptation. no significant differences were found between led-fast and conventional groups in both main condensation groups. this could be attributed to the fact that both led-fast and conventional halogen light modes did not allow material flow during polymerization as in led-ramp mode.(26) there was a significant difference in the microleakage score between the two types of condensation as the vibration method recorded significantly less leakage (table 3). in the conventional group, there were no significant differences by using different curing modes. in the vibration method, no significant differences were found between led-ramp and led-fast mode (p=0.989). also, there were significant differences between led-fast and halogen (p=0.05) and highly significant differences between led-ramp and halogen group (p=0.001). these results showed that vibration would result in better adaptation of the resin composite to the walls of the cavity as compared to the conventional hand plugger and ultimately producing less microleakage. for all groups, microleakage scores of all cervical walls were significantly higher compared to that of all occlusal walls (p=0.001) as shown in table (4). there were no differences in the score of occlusal walls leakage for conventional and vibration groups (p=0.475), while there were highly significant differences between two main groups regarding leakage of cervical walls (p=0.001) as seen in table (5). these results could be due to the differences in the arrangement of the enamel rods between the cervical and coronal parts of the tooth. these observations agree with the previous studies(29-32) but disagree with other studies.(24-29,33,34) as in the current study the cervical walls were located in enamel while in the previous studies were located in dentin and marginal leakage at dentin was more than in enamel.(29,31) also, these differences may be attributed to differences in placement techniques. vibration technique, as reported in this study seems to promote cervical integrity. conclusion vibration technique in the insertion of composite decreases marginal leakage significantly as compared to conventional hand plugger. the decrease in marginal leakage is also affected by light curing modes used, especially with ledramp mode produced less leakage compared to the led-fast and halogen continuous modes. refrences 1. radhika m, sajjan g, kumaraswamy b, mittal n. effect of different placement techniques on marginal microleakage of deep class-ii cavities restored with two composite resin formulations. j conserv dent. 2010;13: 9-15. 2. ben-amar a, slutzky h, matalon s. the influence of 2 condensation techniques on the marginal seal of packable resin composite restorations. quintessence int. 2007;38: 423-428. 3. schneider l, cavalcante l, silikas n. shrinkage stresses generated during resin-composite applications: a review. j s dent biomech. 2010;114. 4. vicente a, ortiz a, bravo l. microleakage beneath brackets bonded with flowable materials: effect of thermocycling. europ j orthodont. 2009;31:390396. 5. gogna r, jagadis s, shashikal k. a comparative in vitro study of microleakage by a radioactive isotope and compressive strength of three nanofilled composite resin restorations. j conserv dent. 2011; 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25: 321-330. 29. walshaw pr1, mccomb d.clinical considerations for optimal dentinal bonding. quintessence int. 1996; 27: 619-25. 30. ferrari m, goracci c, sadek f, eduardo p, cardoso c. microtensile bond strength tests: scanning electron microscopy evaluation of sample integrity before testing. eur j oral sci. 2002; 110: 385-91. 31. hansen se, swift ej jr. microleakage with gluma: effects of unfilled resin polymerization and storage time. am j dent. 1989; 2: 266-8. 32. malmström hs1, schlueter m, roach t, moss me. effect of thickness of flowable resins on marginal leakage in class ii composite restorations. oper dent. 2002; 27: 373-80. 33. muangmingsuk a, senawongse p, yudhasaraprasithi s. influence of different soft start polymerization techniques on marginal adaptation of class v restorations. am j dent. 2003; 16:117-119. 34. nalcaci a, ulusoy n, küçükeşmen c. effect of led curing modes on the microleakage of a pit and fissure sealant. am j dent. 2007; 20: 255-258. الخالصة هذه الدراسة استهدفت. المحضر بسهولة مع جدران تجويف السن وتلتصق: يقلل االهتزاز من لزوجة المادة الراتنجية، مما يجعلها تتدفق خلفيةال .على التسرب المجهري للحشوات الراتنجيةواستخدام طرق تصلب الحشوات تاثير االهتزازلمعرفة األسنان عشوائيا إلى تقسيم. تم قلوعةلستين من الضواحك الم يسطح الشدق الالمواد والطريقة: تم إعداد تجاويف من الفئة الخامسة على ( وفقًا ألنماط معالجة 10= ع إلى ثالث مجموعات فرعية ) قسمت التقليدية(. ثم الطريقة )االهتزاز و لوضع الحشوة ( وفقا 30= عمجموعتين ) هاملئ ثم single bond universal الالصق ستخداموا (. تم حفر التجويفات halogenو led-fastو led-rampالضوء )أوضاع (. z350 ®filtek( حشوةب . وياليد المدكباستخدام وضعهافي المجموعة التقليدية، تم و )kerr ,tmcompothixo)باستخدام وضع الحشوةفي مجموعة االهتزاز، تم العينات تم وضع . (والهالوجين المستمرة على التوالي ledالمستمرة والمنحدرة led) هيالمجاميع جميعل تصلب الحشوةكانت أوضاع تم غمر جميع ، الحشوةملم واحد فقط حول بقاء طبقتين من طالء األظافر مع ب ثم صبغت درجة مئوية لمدة سبعة أيام، 37في الماء المقطر عند https://www.ncbi.nlm.nih.gov/pubmed/22026005 http://www.sonicfill.eu/ https://scholar.google.com/citations?user=ltcok0iaaaaj&hl=en&oi=sra http://www.ijmd.ro/articole/205_38_pdfsam_revista%20ijmd%20nr%203-2011%20final.pdf http://www.ijmd.ro/articole/205_38_pdfsam_revista%20ijmd%20nr%203-2011%20final.pdf https://www.ncbi.nlm.nih.gov/pubmed/?term=yazici%20ar%5bauthor%5d&cauthor=true&cauthor_uid=19212529 https://www.ncbi.nlm.nih.gov/pubmed/?term=celik%20c%5bauthor%5d&cauthor=true&cauthor_uid=19212529 https://www.ncbi.nlm.nih.gov/pubmed/?term=dayangac%20b%5bauthor%5d&cauthor=true&cauthor_uid=19212529 https://www.ncbi.nlm.nih.gov/pubmed/?term=ozgunaltay%20g%5bauthor%5d&cauthor=true&cauthor_uid=19212529 https://www.ncbi.nlm.nih.gov/pubmed/19212529 https://www.ncbi.nlm.nih.gov/pubmed/19212529 https://www.ncbi.nlm.nih.gov/pubmed/?term=walshaw%20pr%5bauthor%5d&cauthor=true&cauthor_uid=9180419 https://www.ncbi.nlm.nih.gov/pubmed/?term=mccomb%20d%5bauthor%5d&cauthor=true&cauthor_uid=9180419 https://www.ncbi.nlm.nih.gov/pubmed/?term=walshaw+and+mccomb%2c+(1996 j bagh college dentistry vol. 32(1), march 2020 effect of dispensing 15 . تم تحليل المعطيات التسرب المجهري باستخدام المجهرطولياً. تم تقييم قطعت ساعات، ثم٪ لمدة ثالث 2زرق األميثيلين الفي محلول العينات . mann-whitney uو kruskal-wallisبواسطة اختبارات في المجموعة التقليدية لم تكن هناك فروق باستخدام طرق عالج بينما .(p=0.028) مجهري تسرب أظهرت مجموعة االهتزاز أقل النتائج: (. بينما كانت هناك led-fastو (led-rampبين وضع p=0.989)) توجد فروق م(. في مجموعة االهتزاز لp=0.277مختلفة ) من التسرب المجهري (. p = 0.001ومجموعة الهالوجين ) led-ramp( وبين p=0.05والهالوجين ) fast ledاختالفات كبيرة بين =pلمجموعات التقليدية واالهتزاز لم تكن مختلفة )ل(. تسرب الجدران اإلطباقية p=0.001اإلطباق )جهة أعلى من كانت السن عنق جهة (. p=0.001) سنعنق ال جهة في حين أن هناك اختالفات كبيرة بينهما في جدران (،0.475 مجهري. قد يقلل من التسرب ال led-ramp لتصلباالهتزاز مع وضع اوضع الحشوة بطريقة : االستنتاجات asmaa f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 36 immunohistochemical expression of e-cadherin and cd44 adhesion molecules in oral squamous cell carcinoma asmaa s. al janabi, b.d.s. (1) seta a. sarkis, b.d.s, m.sc., ph.d. (2) abstract background: head and neck squamous cell carcinoma is the sixth most common cancer world wide. despite greater emphasis on multi-modality therapy including surgery, radiation and chemotherapy, advanced stage head and neck squamous cell carcinoma continues to have poor 5-year survival rates (0-40%) that have not significantly improved in the last (30) years. to improve outcomes for this deadly disease , it is required a better understanding of the mechanisms underlying head and neck squamous cell carcinoma tumor growth, metastasis, and treatment resistance. this study evaluates the immunohistochemical expression of e-cadherin and cd44 adhesion molecules in oscc and to correlate the expression of either marker with each other, with lymph node metastasis and with tumor grade. materials and methods: thirty blocks of oscc were included in this study. an immunohistochemical staining was performed using anti e-cadherinand anti cd44 monoclonal antibodies. results: negative immunohistochemical expression of e-cadherin was found in(66.7%)of the cases and only (33.3%)revealed positive immunoexpression. positive cd44 immunoreaction was seen in(86.7%)of the cases. there was no statistically significant correlation regarding either marker with respect to the tumor stage, grade and lymph node matastasis. moreover anon-significant correlation was found between the expression of both markers. conclusions: this study revealed negative e-cadherin expression in two thirds of the cases, while positive cd44 was illustrated in most of them. nonsignificant correlation was found regarding the expression of both markers with tumor stage, grade and lymph node status. inverse significant correlation was found regarding cd44 expression with the clinical presentation of the study sample. in addition, non significant correlation was found between the e-cadherin and cd44 immunoexpression. key words: oral squamous cell carcinoma, adhesionmolecules, e-cadherin, cd44, immunohistochemistry. (j bagh coll dentistry 2013; 25(special issue 1):36-42). الخالصة بالرغم من التاكیدالشدیدعلى العالج المتعدد االشكال الذي یشمل الجراحة،االشعاع والعالج الكیمیائي،مراحل متقدمة من . سرطان الخالیا الحرشفیة للراس والرقبة ھو السادس االكثرشیوعا في كل العالم:الخلفیة ولتحسین النتائج لھذا المرض الممیت یحتاج الى فھم . والذي لم یتقدم بشكل مفید في السنوات الثالثین االخیرة%) 40-0(سنوات للبقاء ھزیل) 5(سرطان الخالیا الحرشفیة للراس والرقبة یواصل امتالكھ مستوى .افضل لاللیة وراء نمو ورم سرطان الخالیا الحرشفیة للراس والرقبة،االنبثاث ومقاومة العالج موقعھ على سطح الخالیا الطالئیة في مناطق تماس خلیة مع خلیة تعرف 0من اھم الجزیئات اللتصاق خلیة مع خلیة في االنسجة الظھاریة على الظھاروھو واحدمحافظة ولللتكوین ي لكادھرین ضرور -االي .بالرباط االلتصاقي .امكانیة االنبثاث من قبل الخالیا السرطانیةین الذي یكون التصاق الخالیا یرتبط بفقدان تشكل الظھار مع اكتساب ركادھ -في اورام االنسان، فقدان االي مولد المضاد في معظم انسجة االنسان وعرف بامتالكھ وظائف متعددة منذ وجد . ھوجزیئة في غشاء الخلیة الذي وجد اوال في الخلیة اللمفیة وعرف ابتدائیا بامتالكھ لوظائف لصق وایواء الخلیة) 44( السي دي ربطت بتقدم الورم ) 44( -سي دي -اشارة حامض الھیالورونیك. ا یتعلق بدوره في االسھام بتقدم الورم في مختلف االورام الصلبة بما في ذلك سرطان الخالیا الحرشفیة للراس والعنقوقد درس فیم. اكتشافھ االول .تراق واالنبثاثخبما في ذلك عملیة اال الالصقة في سرطان الخالیا الحرشفیة للفم وربط ظھور كل منھما بمرتبة الورم واالنبثاث للعقد ) 44(كادھرین والسي دي-ي المناعي لجزیئات االيیم وربط الظھور الكیمیائي النسیجیھذه الدراسة الى تقتھدف .اللمفیة جرى صبغ . لمقاطع النسیجیة المثبتة بالفورمالین والمطمورة بشمع البارافینالشخاص مصابین بسرطان الخالیا الحرشفیة للفم والتي استخرجت من ا استرجاعیة تضمنت ھذه الدراسة ثالثین عینة:المواد والطرق على شرائح نسیجیة ) 44( -كادھرین ومضاد السي دي -اجریت الصبغات الكیمیائیة النسیجیة المناعیة باستخدام مضاد االي. كل عینة بالھیماتوكسلین واالیوسین العادة تقییمھا لغرض الفحص النسیجي المرضي .یقة من العیناتدق :عینة من سرطان الخالیا الحرشفیة للفم كمایلي) 30(نتائج ظھرت :النتائج .1:2مع نسبة الذكور الى االناث %) 70(سنة ومعظم الحاالت ھم من الذكور) 50(سجلت اكثرالحاالت في االعمارمافوق • .%)50(ومعظمھا ظھرت سریریا بشكل تقرح %) 7,36(وجدت معظم الحاالت في اللسان • .واضحة التماییز%) 30(متوسطة التماییز وفقط من الحاالت %) 70(الفحوصات النسیجیة المرضیة اظھرت ان • .كادھرین-اظھرت ایجابیة الظھورالمناعي لالي%) 3,33(وفقط %) 7,66(في ظھرت كادھرین -سلبیة الظھورالكیمیائي النسیجي المناعي لالي • وفقط ) 1(اظھرت الدرجة %) 7,6(، )2(اظھرت الدرجة %) 7,26(، ) 3(اظھرت الدرجة %) 7,46(من بینھا من الحاالت %)7,86(في )44(نسیجي المناعي للسي دي لوحظ ایجابیة الظھورالكیمیائي ال • .)44( -من ایجابیة االصطباغ المناعي للسي دي) 4(اظھرت الدرجة %) 7,6( عالوة على ذلك لم یوجد أي ارتباط معنوي بین الظھورلكال المؤشرتین الحیویتین مع . مرحلة الورم واالنبثاث للعقد اللمفیةو شرتین الحیویتین ودرجةي معنوي بین أي من المؤلم یكن ھناك اي ارتباط احصائ • .بعضھما البعض ارتباط وجد . في معظم الحاالت لسرطان الخالیا الحرشفیة للفم) 44( -المناعي للسي دي ایجابیة الظھور وجدتكادھرین في ثلثي الحاالت بینما -سلبیة الظھورالمناعي لالي ھذه الدراسة اظھرت :االستنتاجات الضافة با. مع الظھور السریري لعینات الدراسة) 44( -عالقة معنویة عكسیة فیما یخص ظھور السي ديوجدت . وحالة العقداللمفیةمرحلة الورم وة المعنوي فیما یخص ظھوركال المؤشرتین الحیویتین مع درج .في الحاالت المدروسة) 44( كادھرین لم یؤثر معنویا في الظھور المناعي للسي دي-الظھور المناعي لالي فأن الى ذلك introduction over 90% of oral cancers (ocs) are squamous cell carcinomas (sccs). they constitute a major health problem in developing countries, representing a leading cause of death. the survival index continues to be small (50%), as compared to the progress in diagnosis and treatment of other malignant tumors. (1) master student. department of oral diagnosis, college of dentistry, university of baghdad (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad this is because patients continue to die from metastatic diseases at regional and distant sites (1). neoplasia or cancer is viewed as a cell cycle disease. although this concept implies that every tumor is defective in one or more aspects of the cell cycle control, it clearly does not mean that oncogenesis targets only oncogenes and the cell cycle clock. development of malignancy appears to require also aberrations in the cell death machinery and cell-cell and/or cell-matrix interactions that cooperate with cell cycle defects. j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 37 many of the processes in which adhesion molecules play central role – anchorage dependent growth, apoptosis, differentiation, and migration are those that are characteristically dysregulated in malignancy (2). adhesion molecules (am) are transmembrane glycoproteins acting as a molecular link between the outside and inside of the cell. the adhesion molecules are involved in the cell differentiation, migration and sorting. broadly, these proteins can be classified into five families including immunoglobulin superfamily, integrins, cadherins, selectins, and cd44(3). alterations of these cell adhesion molecules are a common event in cancer. the disrupted cell-cell or cell-ecm adhesion significantly contributes to uncontrolled cell proliferation and progressive distortion of normal tissue architecture. more importantly, changes in cell adhesion molecules play a causal role in tumor dissemination. loss of cell adhesion contacts allows malignant cells to detach and to escape from the primary mass (4,5). e-cadherin, a calcium-dependent cell adhesion molecule,is a cell membrane-associated protein involved in cell–cell adhesion, and loss of expression of the cadherin/catenin complex has been described in various human malignancies (6). changes or alterations in the function and expression of this cell to cell adhesion molecule have been postulated to be an early event in the multiple step process of tumour metastasis and an important factor in tumour progression(7). the loss of cadherines expression was observed in many types of carcinomas and usually it is associated to late stages of the disease and to the progression of malignant epithelial neoplasias (8). cd44 was first described by dalchau et al. as a molecule present on the surface of tlymphocytes, granulocytes, and cortical thymocytes (9). human cd44 is a transmembrane hyaluronan-binding glycoprotein that can bind to hyaluronic acid, an extracellular matrix, and regulate a variety of cellular functions, such as cell migration, proliferation, cell–cell interaction, and apoptosis (10). these cellular functions of cd44 imply that a disorder of cd44expression plays a crucial role in the behavior of a malignant tumor (11). cd44 plays an important rolein metastases. in oscc, decreased immnoexpression is associated with increased invasive potential of tumors and the presence of metastases (12, 13). since (am) are involved in many fundamental processes of the cell involving normal physiological growth and development as well certain pathological conditions (wound heals, inflammation and neoplasia) and the loss of their expression or disordered expression plays important roles in the behavior of malignant tumors, therefore, this study concerned ecadherin and cd44 adhesion molecules to elucidate their role in oscc development and progression. materials and methods thirty formalin-fixed paraffin-embedded tissue blocks of oscc were collected the archieves of the department of oral diagnosis ⁄ college of dentistry ⁄ baghdad university;alshaheed ghazi hospital/medical city/baghdad; and private laboratories in baghdad and najaf, dated from(2000-2012). four-micrometer-thick sections were cut from each paraffin tissue block and stained with hematoxylin(mayer′s) and eosin for diagnostic confirmation and histological grading. another two 4-µm section was cut from each tissue block and mounted on positively charged slides (fisher super frost,usa) to be stained with monoclonal antibodies to e-cadherin and cd44 (abcam). negative and positive tissue controls were included into each immunohistochemical run (according to the manufacturer). immunostaining five micrometer thick sections were cut and mounted on (fisher super frost, usa) positively charged slides, then deparaffinized and rehydrated for immunohistochemical staining by e-cadherin and cd44(abcam) monoclonal antibodies;heat mediating antigene retrieval was done for cd44 using phosphate buffer ph(6) then the sections were immersed in hydrogen peroxide (h2o2) to block the endogenous peroxidase activity, washed in phosphate-buffered saline (pbs), and then protein blocking reagent and incubated for 20 minutes at 37 c within humid chamber to reduce non specific staining. the tissue sections were incubated with mouse monoclonal [5h9] antihuman e-cadherin antibody (diluted 1:10) and cd44 (diluted 1:50) antibodies for one hour at 37 c.after that the slides were kept in the refrigerator at 4 c over night in humid chamber. the bounded antibodies were detected by the streptavidin-biotin complex method, after an immunoreaction, the sections were counterstained with hematoxylin (mayer’s). scoring system the scoring of the markers was done by examining of at least 1000 cells per section in five different representative fields. the membranous or membranous and cytoplasmic was considered positive for e-cadherin and membranous was considered positive for cd44 immunostaining. the percentage of positive cells was scored as j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 38 follows:score (0):<10% positive cells,score(1):1025%positive cells,score(2):25-50%positive cells,score(3):50-75%positive cells and score(4):>75%positive cells (14). statistical analysis the data was compiled into statistical software, statistical package of social sciences (spss) version 17. all variables were compared using chisquare test. while pearson correlation coefficient was applied to plot a correlation matrix among the different immunohistochemical markers expression values altogether. p values of less than 0.05 were considered statistically significant. anova test was carried out to compare the numerical values of the study samples, spearman′s rho was also applied in order to find any possible correlation between the categorical variables of the study sample. results: the results of (30) oral squamous cell carcinoma cases were designed as follows: most of the cases (62%) aged > 50 years; the majority of the cases were males (70%) with male to female ratio 2:1.the most common site was the tongue (36.7%). most of the cases presented clinically as ulcer (50%). histopathological examination showed that (70%) of the cases were moderately differentiated and only (30%) were well differentiated carcinomas. negative immunohistochemical expression of e-cadherin was found in(66.7%) of the cases and only (33.3%) revealed positive immunoexpression. positive cd44 immunoreaction was seen in (86.7%) of the cases, of which (46.7%) presented score (3), (26.7%) score (2), (6.7%) score (1) and only (6.7%) presented score (4) cd44 positive immunostaining. table 1: age and sex distribution of the study sample age no. % 50> 18 62 50≤ 11 37 29* 99 sex male 21 70 female 9 30 30 100 *1 case the age was not recorded. table 2: e-cadherin ihc expression in oscc cases e-cadherin score* frequency valid percent valid 0 20 66.7 1 7 23.3 2 2 6.7 3 1 3.3 total 30 100.0 *score 0:<10% positive cells,score 1:10-25% positive cells,score 2:25-50%positive cells,score 3:50-75% positive cells,score 4:>75% positive cells. figure 1: positive brown membranous and /or cytoplasmic immunostaining of ecadherin in well differentiated osccbuccal mucosa(400x). figure 2: positive brown membranous immunostaining of e-cadherin in moderately-differentiated oscc-maxilla (400x). table 3: cd44 ihc expression in oscc cases cd44 score * frequency percent valid 0 4 13.3 1 2 6.7 2 8 26.7 3 14 46.7 4 2 6.7 total 30 100.0 *score 0:<10% positive cells,score 1:10-25% positive cells,score 2:25-50% positive cells,score 3:50-75% positive cells,score 4:>75% positive cells. j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 39 figure 3: positive brown membranous immunostaining of cd44 in well differentiated oscc –buccal mucosa (400x). figure 4: positive brown membranous immunostaining of cd44 in moderately differentiated oscc –buccal mucosa (400x). table 4: the correlation of e-cadherin & cd44 expressions. cd44 scores e cadherin scores cd44 scores pearson correlation 1 0.124 sig. (2-tailed) *0.513 n 30 30 ecadherin scores pearson correlation 0.124 1 sig. (2-tailed) *0.513 n 30 30 *p value more than 0.05 is considered nonsignificant table 5: correlation of cd44 and e-adherin scores with the clinical presentation using spearman's rho. scores sperman's rho clinical presentation cd44 score r sig. (2-tailed) n **-.419 0.033* 26 e-cadherin score r sig. (2-tailed) n -.277 0170 26 * correlation is significant at the 0.05 level (2-tailed) . ** negative(-ve) indicates a reverse correlation . there was no statistically significant correlation regarding either markers with respect to the tumor grade, lymph node status and stage .moreover a statistically non significant correlation was found between the expressions of both markers. discussion this study is not a large epidemiological one that expressed the incidence and prevalence of different clinicopathological features of oscc. the clinicopathological information were evaluated and analyzed for only (30) oscc surgical specimens, however, there is a close correlation between the present data and other published data concering the incidence of oscc in previous foreign and iraqi studies records. assessment of e-cadherin immunohistochemistry the results of this study showed reduction in the immunoexpression of e-cadherin in (66.7%) of the cases, this is in agreement with the findings of williams et al. who found e-cadherin underexpression in carcinoma in situ cases and infiltrative tumors and santos et al. who recorded e-cadherin underexpression in (90%) of oral squamous cell carcinoma cases (15,16). generally e-cadherin is expressed as membranous immunostaining, but cytoplasmic expression (a translocation of this marker into the cytoplasim) was detected in some cases of the study sample such finding was also found by massarelli et al. and aguiar et al. who observed higher cytoplasmic expression of e-cadherin in oscc with nodal metastasis(17,18). in fact, a redistribution of the e-cadherin complex out of tight junctions can affect its functions in cell-cell adhesion and increase its degradation by cytoplasmic endocytosis resulting in cytoplasmic e-cadherin expression(19). this study revealed a non-significant correlation regarding e-cadherin expression with any of the clinicopathological data including the tumor stage, grade and lymph node involvement. generally, more aggressive oral carcinomas show loss of epithelial cell cohesion, and this is often associated with a reduction in e-cadherin expression. however, loss of cohesion may also be due to reduced e-cadherin function as a result of sequence mutation or by abnormalities in the cadherin-catenin complexes. thus, e-cadherin may still be detected by immunohistochemistry, even in non-functional form, and this possibly explains some of the apparently conflicting results produced by immunohistochemical studies on oral carcinoma. furthermore, several factors such as the sample size, methods of histological grading of j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 40 malignancy, the visual judgment of pathologists ,type of antibody used, immunohistochemical techniques, the choice whether to use frozen or paraffin embedded material, relative subjectivity in interpreting and scoring the staining results and the cellular heterogeneity of oscc may also be responsible for those conflicting results(20). assessment of cd44 immunohistochemistry the expression of different cd44 isoforms in hnscc has been studied, but their role remained controversial. whereas some studies have found a correlation between increased cd44 expression and hnscc progression, others have reported no such correlations or negative correlations (21). in the present study isoform (10)epithelial isoform is used, but regardless to its type, the study focused on the tissue specificity of the marker namely epithelial cells in which cd44 expressed in carcinomas was indicated according to the manufacturer data sheet. the results of this study showed that most of the studied cases(86.7%) presented positive cd44 immunostaining ,of which (46.7%) revealed score (3)immuno expression, and only(13.3%) of the studied cases were negative.similar results reported in other studies in different cancers including head and neck, breast ,lung ,gastrointestinal, bladder, cervical carcinomas by employing immunohistochemical staining,rtpcr and northern blotting techniques and using different isoforms of cd44(22,23,24). in the present study no correlation was found between the histological grade of the tumors and the cd44 expression,this finding is in agreement with herold-mende et al and van hale who also found no correlation regarding cd44splice variants expression and any clinicopathological variables (25,26). however, ue et al. found that the reduction in the expression of certain variants of cd44 was correlated with tumor cell differentiation in primary oscc cases(27). concerning the relation of cd44 expression with the tumor stage, a non –significant correlation was found . similar results recorded by van hal et al. and kanke et al. who found (96%) cd44v6 immunoexpression in hnscc, with no correlation to the tumor stage (26,28). while other investigators revealed that cd44 play crucial role in tumor progression and its expression is correlated well to the tumor stage (29-31). regarding the relation of cd44 immunoexpression with lymph node involvement, this study showed a non-significant correlation, as mentioned previously, this finding may be due to the small size of the node positive cases enrolled in this study (14 out of 30). another investigators found direct correlation between increased or decreased expression of cd44variant isoforms with lymph node involvement and development of metastasis within different kinds of tumors in different organs(32,33) . the present study revealed an inverse significant correlation between cd44 immunostianing and the clinical presentation of the studied cases. no previous studies highlighted such correlation to compare with; however, this inverse correlation suggests that reduced cd44expression is associated with increased tumor aggrasiveness (ulcer), while increased expression of cd44 is associated with decreased tumor aggressiveness (mass). there are some possible explanations for the discrepant results among different studies regarding the correlation between cd44expression and the clinicopathological presentation, these could be, the employment of different antibodies (cd44 different isoforms), which makes comparison between research groups difficult.moreover, certian cd44 variant domain epitopes may become hidden and not regognized by some antibodies due to post -translational changes which alter the three-dimensional conformation of the protein.in addition, assessment of immunostaining positivity is dependant on what region of the tumor is examined, size of the study sample, method used for assessment of cd44 expression (rt-pcr, fish, immunohistochemistry ….etc), techniques of immunohistochemistry (manual or automated) (34,35,36). assessment of the correlation between ecadherin and cd44 immunohistochemical expression: regarding the correlation between both markers, the results revealed a non-significant correlation between them, i.e,each marker acts independently(each marker works alone) . furthermore, either markers showed no correlation to tumors stage, grade and lymph node status.similar results revealed by (carmen et al. and vazifeh et al., ivsl) (36,37).however,different findings revealed by simionescu et al.(14). indeed, the cellular and molecular processes involved in malignant neoplasms are complex. further studies are required to clarify the role of ecadherin and cd44 ams in the development and progression of osccs. fortunately, the progress in the area of adhesion molecules is expected to be rapid in the following years. this may result in novel prognostic and therapeutic tools in the problematic field of head and neck cancer. it j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 41 seems that this interesting journey is long and we are just at the beginning. references 1. pantel k, brankenhoff rh. dissecting the metastatic cascade. nat rev cancer 2004; (6):448-456. 2. lukas z, dvofiak k. adhesion molecules 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leukocyte-specific membrane glycoprotein probably homologous to the leukocyte-common (l-c) antigen of the rat. eur j immunol 1980; 10:737– 744 (ivsl) 10. sato s, miyauchi m, takekoshi t. reduced expression of cd44 variant 9 is related to lymph node metastasis and poor survival in squamous cell carcinoma of tongue. oral oncol 2000; 36:545–549. 11. gonzalez-moles ma, gil-montoya ja, ruiz-avila i, esteban f, delgado-rodriguez m, bascones-martinez a. prognostic significance of p21waf1/cip1, p16ink4a and cd44s in tongue cancer. oncol rep 2007; 18:389–396. 12. carinci f, stabellini g, calvitti m, pelucchi s, targa l, farina a, pezzetti f, pastore a. cd44 as prognostic factor in oral and oropharyngeal squamous cell carcinoma. j craniofac surg 2002; 13: 85–89. 13. sato s, miyauchi m, kato m, kitajima s, kitagawas, hiraoka m, kudo y, ogawa i, tata t. upregulated cd44v9 expression inhibits the invasion of oral squamous cell carcinoma cells. pathobiology 2004; 71(4):171–175. 14. simionescu cl, margaritescu m, surpateanu l, mogoanta r, zavoi r, ciurea p, surlin a, stepan. the study of e-cadherin and cd44 immunoexpression in oral squamous cell carcinoma. romanian journal of morphology and embryology 2008; 49(2):189-193. 15. williams hk, sanders ds, jankowski ja, landini g, brown am. expression of cadherins and catenins in oral epithelial dysplasia and squamous cell carcinoma. j oral pathol med 1998; 27:308-17. 16. santos-garcia a, abad-hernandezm m, fonsecasanchez e, julian-gonzalez r, galindovillardon p, cruz-hernandezj j, bullon-sopelana a. e-cadherin, laminin and collagen iv expression in the evolution from dysplasia to oral squamous cell carcinoma. med oral patol oral cir bucal 2006; 11(2): 100–105. 17. lin yc, wu my, li dr, wu xy, zheng rm. prognostic and clinicopathological features of ecadherin, alpha-catenin, beta-catenin, gamma-catenin and cyclin d1 expression in human esophageal squamous cell carcinoma, world j gastroenterol 2004; 10(22): 3235–3239. 18. massarelli e, erika b, ngoc kt, diane d liu , julie gi, lee jj, el-naggar a k, waun kh, vassiliki ap. loss of e-cadherin and p27 expression is associated with head and neck squamous tumorigenesis. american cancer society, wiley inter science, january; 2005. 19. aguiar júnior fca, kowalski lp, almeida op. clinicopathological and immunohistochemical evaluation of oral squamous cell carcinoma in patients with early local recurrence. oral oncol 2007; 43:593601. 20. fujita y, krause g, scheffner m. hakai. a c-cbl-like protein, ubiquitinates and induces endocytosis of the e-cadherin complex. nat cell biol 2002; 4:222–231. 21. georgolios a, batistatou a, manolopoulos l, charalabopoulos k. role and expression patterns of e-cadherin in head and neck squamous cell carcinoma (hnscc). j exp clin cancer res 2006; 25(1). 22. reategui ep, de mayolo aa, das pm, astor fc, singal r, hamilton kl, goodwin wj, carraway kl, franzmann ej: characterization of cd44v3containing isoforms in head and neck cancer. cancer biol 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(ivsl) 24. kahara n, ozaki t, doi t, nishida k, kawai a, shibahara m, inoue h. cd44 in soft tissue sarcomas. virchows arch 2000; 436: 574-578. 25. ylagan lr, scholes j, demopoulos r. cd44: a marker of squamous differentiation in adenosquamous neoplasms. arch pathol lab med 2000; 124: 212-215. 26. herold-mende c, seiter s, born ai, patzelt e, schupp m, zöller j, bosch fx, zöller m. expression of cd44 splice variants in squamous epithelia and squamous cell carcinomas of the head and neck. j pathol 1996;179:66–73 27. van hal nl, van dongen ga, stigter-van walsum m, snow gb, brakenhoff rb. characterization of cd44v6 isoforms in head and neck squamous cell carcinoma. int j cancer 1999; 82: 837845. 28. ue t, yokozaki h, kagai k, higashikawa k, yasui w, sugiyama m, tahara e, ishikawa t. reduced expression of the cd44 variant exons in oral squamous cell carcinoma and its relationship to metastasis. j oral pathol med 1998; 27: 197-201. 29. kanke m, fujii m, kameyama k, kanzaki j, tokumaru y, imanishi y, tomita t, matsumura y: clinicopathological significance of expression of cd44 variants in head and neck squamous cell carcinoma. jpn j cancer res 2000; 91:410–415 30. sato s, miyauchi m, kato m, kitajima s, kitagawas, hiraoka m, kudo y, ogawa i, tata t. upregulated cd44v9 expression inhibits the invasion of oral squamous cell carcinoma cells. pathobiology 2004; 71(4):171–175. j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 42 31. garcía-montesinos-perea b, val-bernal jf, saizbustillo r. epidermoid carcinoma of the lip: an immunohistochemical study. med oral patol oral cir bucal 2005; 10:454-461. 32. kosunen r, pirinen k, ropponen m, pukkila j, kellokoski j, virtaniemi r, sironen m, juhola e, kumpulainen r, johansson j, nuutinen, kosma. cd44 expression and its relationship with mmp-9, clinicopathological factors and survival in oral squamous cell carcinoma. oral oncol 2007; 43:51– 59.(ivsl) 33. massano j, regateiro fs, januario g, ferreira a. oral squamous cell carcinoma: review of prognostic and predictive factors. oral surg oral med oral pathol oral radiol endod 2006; 102:67–76. 34. lyons aj& jones j. cell adhesion molecules, the extracellular matrix and oral squamous carcinoma. int joral maxillofac surg (2007); 36 :671–679. 35. mack b &gires o. cd44s and cd44v6 expression in head and neck epithelia. plos one 2008; 3: 3360. 36. carmen mf, antonio la, fernanda f, cassiano fw, raimunda r, roseana a, lelia b, leao pp. immunohistochemical expression of e-cadherin and cd44v6 in squamous cell carcinomas of the lower lip and tongue. braz dent j 2009; 20(1):64-69. 37. vazifeh l, mostaan m, khorsandi t, shahriarmohammed rs, fatemeh hs, fatemeh m, homa s, reza b, hasti b, nasrin y. correlation between ecadherin and cd44 adhesion molecules expression and cervical lymph node metastasis in oral tongue scc:predictivre significance or not. cancer research centre, mashhad university of medical sciences, iran, pathology –research and practice 2011; 207: 448-451.(ivsl) haitham f.docx j bagh college dentistry vol. 28(2), june 2016 the effect of restorative dentistry 7 the effect of ceramic thickness and number of firings on the color of two all-ceramic systems measured by spectrophotometer zaid abdul mahdi abdul ameer al marah, b.d.s. (1) haitham j. al-azzawi, b.d.s., m.sc. (2) abstract background: this in vitro study was carried out to evaluate the effects of various veneering dentin ceramic thicknesses and repeated firings on the color of lithium disilicate glass-ceramic (ips e.max press) and zirconium-oxide (ips zircad) all-ceramic systems, measured by clinical spectrophotometers (easyshade advance 4.0) . materials and methods: the 72specimens cube-shaped have the dimension of about 11 mm in width, 14 mm in length, 1mm in thickness, these cores divided into 3 groups according to the type of material each group have (24)core specimens. each group had been divided into three sub-groups (each having 8 specimens) according to veneering with dentin ceramic thicknesses: as 0.5, 1, or 2 mm (n=8). ips e.max press and zircad cores group had been veneered with ips e.max ceram dentin ceramic shade a2 according to manufacturer’s instructions and the metal group had been veneered with ips classic dentine ceramic with shade a2 according to manufacturer’s instructions. repeat firings (3, 5 and 7 times) had been applied on all the specimens. color differences among ceramic specimens had been measured using a clinical spectrophotometer (vita easyshade); the color data had been expressed according the vita classic shade guide. results: the shade of all specimens had been compared inside the subgroups and with the main groups. the percentage of color agreement among the subgroups showed the color of all ceramic systems had been affecting by firing interval, the ceramic thickness and brand of ceramic. the number firings intervals applied on the all ceramic system has a significant effect on the final color, the increase of firing number change the color to a darker and reddish color. the 5th firing interval is the point at which the major color changes happened (darker shade), and in next interval (7th firing) less color changes happened. the thickness of veneering ceramic affected the color significantly. the 0.5 mm specimens in all groups showed the highest percentage of agreement (less color changes) after firing intervals, then the 1mm came and the least percentage of agreement ( highest color changes ) was the 2 mm specimens. the brand of veneering ceramic and the type of core record a significance difference in color changes when exposed to firing heat. conclusion: with limit of this study, the final color of the all ceramic system definitely affected by the number of firing cycle exposed to, and the veneering ceramic thickness have a clear effect on the final shade of the all ceramic tested. keywords: color, shade measurement, dental porcelain, dental zirconia, e.max all ceramic system, cad/cam. (j bagh coll dentistry 2016; 28(2):7-13). introduction all-ceramic restorations are developed rapidly and used widely nowadays; there is a lack of information on the way that the color is affected by manipulation and fabrication procedures. most all ceramic systems require the application of two layers of ceramic material, such as a core (strong ceramic) and a veneering porcelain (weak ceramic) (1) with different shade, opacity, and thickness, to provide a natural appearance (2, 3). all ceramic restorations without a metal core allow more light transfer within the restoration, this happened by improving the color and translucency of the restoration; however, a perfect esthetic tooth-colored restoration cannot be ensured (4). the amount of light that is transmitted, absorbed, and reflected depends on, the size of the particles compared to the incident light wavelength and the quantity of crystals within the core matrix, their chemical nature (5). (1) master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. the translucency of the core was also considered as a primary factor in controlling esthetics and a critical consideration in the selection of the materials (6). many factors affect the ability of a ceramic system to produce good match with corresponding shade guides, such as condensation techniques, firing temperatures and dentin ceramic layer thickness. the effects of dentin thickness on the color of metal-ceramics were studied, and the researchers reported that a clinically acceptable shade match was influenced by this parameter (7). a study examining color changes of surface colorants after firing have demonstrated pigment breakdown at firing temperatures (8). hue, chroma and value color parameters of metal-ceramic specimens, which were fired 1.68°c and 21°c above the manufacturer’s instructions firing temperature, indicated substantial differences in color (9).instrumental measurements can quantify color shade and allow communication to be more uniform and precise. development of advanced computerized colorimeters and spectrophotometers has j bagh college dentistry vol. 28(2), june 2016 the effect of restorative dentistry 8 increased their use in dental applications. spectrophotometers measure the absorption or transmittance or reflectance factors of an object for one wavelength at a time. material and methods sample preparation: group a(zirconia based all ceramic system): twopresented y-tzp block (ips e.maxzircad, ivoclarvivadent, schaan, liechtenstein)were divided to specimens (dimensions: 1.4-1.5 mm in height, 15.5mm in width,19mm in length). then the specimens were sintered in furnace (infirehtc speed sintering furnace, sirona) according to the cycle recommended by manufacturer. after sintering, approximately 25% shrinkage was occurred in zirconia specimens. after sintering, the dimensions of specimens was about (11.7 mm in width, 14.3 mm in length, 1 in height), then(24) zirconia core specimens were divided randomly to three subgroups according to the veneering ceramic thickness added, each subgroup contains (8) specimens. these subgroups are: group a1: zirconia core of 1 mm and veneering ceramic thickness 0.5 mm. group a2: zirconia core of 1 mm and veneering ceramic thickness 1 mm. group a3: zirconia core of 1 mm and veneering ceramic thickness 2 mm. all specimens were cleaned with water for (10) minutes in a digital ultrasonic cleaner (model cd-4820\china), and air dried. a liner was applied to all specimens by using a brush to create an even layer (7).then zirliner was fired in calibrated porcelain furnace (p3000, ivoclarvivodent, schaan, liechtenstein) according to the manufacturer’s recommendations. then the ceramic (ips e.max ceram dentine a2) was added incrementally onto the customizemade stainless steel mold (on one of the surfaces of the zirconia) by using brush, the excess liquid sucked off with paper tissue, the veneering procedure was continued until the mold completely filled. because of the volumetric shrinkage during firing of porcelain, the rings of the custom made mold designed larger in size to compensate the shrinkage and achieve the exact thickness needed. eight samples of each thickness (0.5mm, 1mm and 2 mm) of veneering ceramic prepared. firing of ceramic\dentin was performed in a calibrated porcelain furnace (p 3000, ivoclar vivadent, schaan, liechtenstein) according to the manufacturer’s recommendations. the same firing cycle repeated 3 times before the first shade test and 2 firing cycles added after each testing procedure (5 and 7 firings). group b (e.maxpress all ceramic system): twenty four specimens prepared by cut the thermoforming sheet (forplast, roko), have dimensions of about (1mm thickness, 10 mm width,10 mm length) for the single specimen. all specimens attached to wax minor sprus, using blue wax wire, each four minor sprus attached to a major connector (major spru). investing was carried out with ips press vest speed (speed investment).burn-out (wax elimination) technique used, the investment ring was removed from the burnout oven to the pressing furnace (p 3000\ ivoclar vivadent) without cooling it. then the pressing procedure achieved with e.mac press ingots after cooling to room temperature the ring was broken by using plaster knife and cutting disc with care. all the specimens were cleaned from the investment remnants and the reacting layer was removed by immersing them in ips e.max press invex liquid for (10-30 min) and washed with water the sandblasted. the same procedure used of applying veneering ceramic in the zirconia group used in the e.max group and for the same thicknesses achieved. then (24) e.max core specimens were divided randomly to three subgroups according to the veneering ceramic thickness added, each subgroup contains (8) specimens. these subgroups are: group b1: e.max press core of 1 mm and veneering ceramic thickness 0.5mm. group b2:e.max press core of 1 mm and veneering ceramic thickness 1 mm. group b3: e.max press core and veneering ceramic thickness 2 mm. group c (porcelain fused to metal system) control group: twenty four specimens prepared by cut the thermoforming sheet (for-plast, roko), in dimensions of about (1mm thickness , 10 mm width, 10 mm length ) for the single specimen. the same steps used of spruing in the e.max press group. then the usual steps of preparing and casting metal cores done (investing, wax elimination ,casting , recovery of casting, finishing , oxide treatment , sandblasting , first opaque application and firing and second opaque firing) . to obtain the desired dimensions of veneering ceramic, the same custom made mold is used in the same method of specimens of zirconia and e.max. then (24) core specimens were divided randomly to three subgroups according to the veneering ceramic thickness added, each j bagj bagh college dentistry restorative dentistry subgroup contains (8) specimens. subgroups group c1 and veneering ceramic thickness group c2 ( and veneering ceramic thickness 1mm group c3 and veneering ceramic thickness color test all the specimens were measured 3 times the firing firings). each type of specimens certain temperature as instructions. shade test by the specimens were placed over a surface of fifty white a4 papers, to ensure a complete wh background especially for the transparent specimens (e.max cores). the easyshade advance 4.0 device was turned on, calibrated and the option average reading was selected. captures were taken and the result of the average shade was recorded b 3, a2, etc.). results shade test easyshade advance 4.0 results: group veneering ceramic thickness the results of this group (table 1) showed a relatively high percentage of agreement when comparing the samples inside the group after each firing interval, happened after firing. table 1: core with ceramic thickness 0.5 mm) 1. percentage of agreement between the 3 firing is 100 %. 2. percentage of agreement between the 3 firing is 87.5 %. 3. percentage of agreement between the 5 firing is 87.5 %. h college dentistry restorative dentistry subgroup contains (8) specimens. subgroups are: c1 (control group) veneering ceramic thickness c2 (control group) veneering ceramic thickness 1mm c3 (control group) veneering ceramic thickness color test all the specimens were measured 3 times the firing interval ( firings). each type of specimens certain temperature as instructions. shade test by easyshade the specimens were placed over a surface of fifty white a4 papers, to ensure a complete wh background especially for the transparent specimens (e.max cores). the easyshade advance 4.0 device was turned on, calibrated and the option average reading was selected. captures were taken and the result of the average shade was recorded for each specimen like (a 3.5, b 3, a2, etc.). results shade test easyshade advance 4.0 results: group a1 (zirconia core with 0.5mm veneering ceramic thickness the results of this group (table 1) showed a relatively high percentage of agreement when comparing the samples inside the group after each firing interval, which happened after firing. : shade results of group a1 (zirconia core with ceramic thickness 0.5 mm) 1. percentage of agreement between the 3 firing is 100 %. 2. percentage of agreement between the 3 firing is 87.5 %. 3. percentage of agreement between the 5 firing is 87.5 %. h college dentistry restorative dentistry subgroup contains (8) specimens. (control group): metal core of 1 mm veneering ceramic thickness 0.5mm. control group): metal core of 1 mm veneering ceramic thickness 1mm (control group): metal core of 1 mm veneering ceramic thickness 2 mm. all the specimens were measured 3 times interval (3 firings, 5 firings and 7 firings). each type of specimens certain temperature as the manufacturer easyshade advance 4.0 the specimens were placed over a surface of fifty white a4 papers, to ensure a complete wh background especially for the transparent specimens (e.max cores). the easyshade advance 4.0 device was turned on, calibrated and the option average reading was selected. captures were taken and the result of the average for each specimen like (a 3.5, shade test easyshade advance 4.0 results: zirconia core with 0.5mm veneering ceramic thickness): the results of this group (table 1) showed a relatively high percentage of agreement when comparing the samples inside the group after each which means less color changes happened after firing. shade results of group a1 (zirconia core with ceramic thickness 0.5 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 h college dentistry vol. 2 subgroup contains (8) specimens. these metal core of 1 mm 0.5mm. metal core of 1 mm veneering ceramic thickness 1mm. metal core of 1 mm 2 mm. all the specimens were measured 3 times after 3 firings, 5 firings and 7 firings). each type of specimens was fired at a the manufacturer advance 4.0 the specimens were placed over a surface of fifty white a4 papers, to ensure a complete wh background especially for the transparent specimens (e.max cores). the easyshade advance 4.0 device was turned on, calibrated and the option average reading was selected. four to five captures were taken and the result of the average for each specimen like (a 3.5, shade test easyshade advance 4.0 results: zirconia core with 0.5mm the results of this group (table 1) showed a relatively high percentage of agreement when comparing the samples inside the group after each means less color changes shade results of group a1 (zirconia core with ceramic thickness 0.5 mm) 1. percentage of agreement between the 3rd and 5 2. percentage of agreement between the 3rd and 7 3. percentage of agreement between the 5th and 7 vol. 28(2), june 9 these metal core of 1 mm metal core of 1 mm metal core of 1 mm after 3 firings, 5 firings and 7 fired at a the manufacturer the specimens were placed over a surface of fifty white a4 papers, to ensure a complete white background especially for the transparent specimens (e.max cores). the easyshade advance 4.0 device was turned on, calibrated and the four to five captures were taken and the result of the average for each specimen like (a 3.5, zirconia core with 0.5mm the results of this group (table 1) showed a relatively high percentage of agreement when comparing the samples inside the group after each means less color changes shade results of group a1 (zirconia and 5th and 7th and 7th group ceramic thickness relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which happened especially after the 7 results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm (group a1). table 1. percentage of agreement between the 3 firing is 75 %. 2. percentage of agreement between the 3 firing is 0 %. 3. percentage of agreement between the 5 firing is 25 %. group a ceramic thickness relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which means much color changes, happened esp results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm table zirconia 1 2 3 4 5 6 7 8 june 2016 group a2 (zirconia core with ceramic thickness the results of this group (table 2) showed a relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which happened especially after the 7 results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm (group a1). table 2: shade results of group a core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 firing is 75 %. 2. percentage of agreement between the 3 firing is 0 %. 3. percentage of agreement between the 5 firing is 25 %. group a3 (zirconia core with ceramic thickness the results of this group (table relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which means much color changes, happened especially after the results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm (group a1 table 3: shade results of group a3 (zirconia core with ceramic thickness 2 mm) zirconia 1 mm 3rd 1 b3 2 b3 3 b3 4 b3 5 b3 6 b3 7 b3 8 b3 zirconia core with ceramic thickness): the results of this group (table 2) showed a relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which means much color changes, happened especially after the 7 results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm shade results of group a core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 (zirconia core with ceramic thickness): the results of this group (table relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which means much color changes, ecially after the results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm (group a1 and group a2 shade results of group a3 (zirconia core with ceramic thickness 2 mm) rd firings 5th b3 a3.5 b3 b3 b3 b3 b3 a3.5 b3 b3 b3 b3 b3 b3 b3 b3 the effect zirconia core with 1mm veneering the results of this group (table 2) showed a relatively low percentage of agreement when comparing the samples inside the group after each means much color changes, happened especially after the 7th firing. these results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm shade results of group a2 (zirconia core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 (zirconia core with 2mm veneering the results of this group (table 3) showed a relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which means much color changes, ecially after the 5th firing. these results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm and group a2). shade results of group a3 (zirconia core with ceramic thickness 2 mm) th firings 7th a3.5 a3.5 b3 a3.5 b3 a3.5 a3.5 a3.5 b3 a3.5 b3 a3.5 b3 a3.5 b3 a3.5 the effect of mm veneering the results of this group (table 2) showed a relatively low percentage of agreement when comparing the samples inside the group after each means much color changes, firing. these results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm (zirconia core with ceramic thickness 1 mm) 1. percentage of agreement between the 3rd and 5th 2. percentage of agreement between the 3rd and 7th 3. percentage of agreement between the 5th and 7th mm veneering ) showed a relatively low percentage of agreement when comparing the samples inside the group after each firing interval, which means much color changes, firing. these results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm shade results of group a3 (zirconia core with ceramic thickness 2 mm) th firings a3.5 a3.5 a3.5 a3.5 a3.5 a3.5 a3.5 a3.5 of j bagj bagh college dentistry restorative dentistry 1. percentage of agreement between the 3 firing is 25 %. 2. percentage of agreement between the 3 firing is 12.5 %. 3. percentage of agreement between the 5 firing is 87.5 %. group b ceramic thic the results of this group (table 4) showed a relatively high percentage of agreement when comparing the samples inside the subgroup after each firing interval and in comparing with other subgroup , which means less color changes happened after there is a between the zirconia core specimens and the e.max core specimens that have the same veneering ceramic thickness and brand during the same firing cycles , that make the core ma real effecting factor on color of all ceramic system . table 4 core with veneering ceramic thickness 0.5 1. percentage of agreement between the 3 firing is 87.5 %. 2. percentage of agreement betwe firing is 75 %. 3. percentage of agreement between the 5 firing is 62.5 %. group b2 (e.max core with 1mm veneering ceramic thickness): the results of this group (table 5) showed a relatively low percentage of agreement when comparing the samples firing cycle inside the sub much color changes, happened especially after the 5th firing that agree with showed a different color changes behavior from the less veneerin e.max core h college dentistry restorative dentistry percentage of agreement between the 3 firing is 25 %. 2. percentage of agreement between the 3 firing is 12.5 %. 3. percentage of agreement between the 5 firing is 87.5 %. b1 (e.max core with 0.5mm veneering ceramic thickness): the results of this group (table 4) showed a relatively high percentage of agreement when comparing the samples inside the subgroup after each firing interval and in comparing with other subgroup , which means less color changes happened after firing . there is a different color changes behavior between the zirconia core specimens and the e.max core specimens that have the same veneering ceramic thickness and brand during the same firing cycles , that make the core ma real effecting factor on color of all ceramic system table 4: shade results of group b1 (e.max core with veneering ceramic thickness 0.5 1. percentage of agreement between the 3 firing is 87.5 %. 2. percentage of agreement betwe firing is 75 %. 3. percentage of agreement between the 5 firing is 62.5 %. group b2 (e.max core with 1mm veneering ceramic thickness): the results of this group (table 5) showed a relatively low percentage of agreement when comparing the samples firing cycle inside the sub much color changes, happened especially after the firing that agree with showed a different color changes behavior from the less veneering ceramic thickness 0.5mm e.max core (group b1). h college dentistry restorative dentistry percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 1 (e.max core with 0.5mm veneering the results of this group (table 4) showed a relatively high percentage of agreement when comparing the samples inside the subgroup after each firing interval and in comparing with other subgroup , which means less color changes firing .the results also showed that different color changes behavior between the zirconia core specimens and the e.max core specimens that have the same veneering ceramic thickness and brand during the same firing cycles , that make the core ma real effecting factor on color of all ceramic system shade results of group b1 (e.max core with veneering ceramic thickness 0.5 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 group b2 (e.max core with 1mm veneering the results of this group (table 5) showed a relatively low percentage of agreement when comparing the samples after the 3 firing cycle inside the subgroup, which means much color changes, happened especially after the firing that agree with(11) . these results showed a different color changes behavior from g ceramic thickness 0.5mm (group b1). h college dentistry vol. 2 percentage of agreement between the 3rd and 5 2. percentage of agreement between the 3rd and 7 3. percentage of agreement between the 5th and 7 1 (e.max core with 0.5mm veneering the results of this group (table 4) showed a relatively high percentage of agreement when comparing the samples inside the subgroup after each firing interval and in comparing with other subgroup , which means less color changes the results also showed that different color changes behavior between the zirconia core specimens and the e.max core specimens that have the same veneering ceramic thickness and brand during the same firing cycles , that make the core material a real effecting factor on color of all ceramic system shade results of group b1 (e.max core with veneering ceramic thickness 0.5 1. percentage of agreement between the 3rd and 5 en the 3rd and 7 3. percentage of agreement between the 5th and 7 group b2 (e.max core with 1mm veneering the results of this group (table 5) showed a relatively low percentage of agreement when after the 3rd and the 5 group, which means much color changes, happened especially after the . these results showed a different color changes behavior from g ceramic thickness 0.5mm with vol. 28(2), june 10 and 5th and 7th and 7th 1 (e.max core with 0.5mm veneering the results of this group (table 4) showed a relatively high percentage of agreement when comparing the samples inside the subgroup after each firing interval and in comparing with other subgroup , which means less color changes the results also showed that different color changes behavior between the zirconia core specimens and the e.max core specimens that have the same veneering ceramic thickness and brand during the terial a real effecting factor on color of all ceramic system shade results of group b1 (e.max core with veneering ceramic thickness 0.5 and 5th and 7th and 7th group b2 (e.max core with 1mm veneering the results of this group (table 5) showed a relatively low percentage of agreement when and the 5th group, which means much color changes, happened especially after the . these results showed a different color changes behavior from with table 1. percentage of agreement between the 3 firing is 12.5 %. 2. percentage of agreement between the 3 firing is 12.5 %. 3. percentage of agreement between the 5 firing is 100 %. group b3 ( ceramic thickness): zero samples inside the group after firing also zero when comparing the samples af 3rd color changes, happened especially after the 5 firing when increasing the firing till 7 agreement between the samples after the 5 the 7 different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm (group group with same veneering ceramic table 6 1. percentage of agreement between the 3 firing is 0 %. 2. percentage of agreement between the 3 firing is 0 %. 3. percentage of agreement between the 5 firing is 100 %. june 2016 table 5: shade results of group b core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 firing is 12.5 %. 2. percentage of agreement between the 3 firing is 12.5 %. 3. percentage of agreement between the 5 firing is 100 %. group b3 (emax ceramic thickness): the results of this group (table zero percentage of agreement when comparing the samples inside the group after firing interval, the percentage of agreement was also zero when comparing the samples af rd and the 7th color changes, happened especially after the 5 firing and there is no changes happened in color when increasing the firing till 7 agreement between the samples after the 5 the 7th firing cycles) fferent color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm (group b1 and group group with same veneering ceramic table 6: shade results of group b2 (e.max core with ceramic thickness 2 mm) 1. percentage of agreement between the 3 firing is 0 %. 2. percentage of agreement between the 3 firing is 0 %. 3. percentage of agreement between the 5 ing is 100 %. shade results of group b core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 firing is 12.5 %. 2. percentage of agreement between the 3 firing is 12.5 %. 3. percentage of agreement between the 5 firing is 100 %. emax core with 2mm veneering ceramic thickness): the results of this group (table percentage of agreement when comparing the samples inside the group after interval, the percentage of agreement was also zero when comparing the samples af thfiring cycle, color changes, happened especially after the 5 and there is no changes happened in color when increasing the firing till 7 agreement between the samples after the 5 firing cycles). these results showed a fferent color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm 1 and group b2) and even from zirconia group with same veneering ceramic shade results of group b2 (e.max core with ceramic thickness 2 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 ing is 100 %. the effect shade results of group b2 core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 core with 2mm veneering the results of this group (table 6) showed a percentage of agreement when comparing the samples inside the group after the 3rd and the interval, the percentage of agreement was also zero when comparing the samples af firing cycle, which means much color changes, happened especially after the 5 and there is no changes happened in color when increasing the firing till 7 times (100 agreement between the samples after the 5 . these results showed a fferent color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm and even from zirconia group with same veneering ceramic thicknesses. shade results of group b2 (e.max core with ceramic thickness 2 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 the effect of (e.max core with ceramic thickness 1 mm) 1. percentage of agreement between the 3rd and 5th 2. percentage of agreement between the 3rd and 7th 3. percentage of agreement between the 5th and 7th core with 2mm veneering ) showed a percentage of agreement when comparing the and the 5th interval, the percentage of agreement was also zero when comparing the samples after the means much color changes, happened especially after the 5th and there is no changes happened in color (100% of agreement between the samples after the 5th and . these results showed a fferent color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm and even from zirconia thicknesses. shade results of group b2 (e.max core with ceramic thickness 2 mm) 1. percentage of agreement between the 3rd and 5th 2. percentage of agreement between the 3rd and 7th 3. percentage of agreement between the 5th and 7th of j bagj bagh college dentistry restorative dentistry group c1 control group (metal core with 0.5mm veneering ceramic thickness): the results of this group (table 7) showed 100 percentage of agreement when comparing the samples inside the group after each firing interval, which means no color firing. the comparison between the group c1 and groups a1, b1 showed that porcelain fused to metal system is not sensitive to firing. table 7: core with ceramic thickness 0.5 mm) 1. percentage firing is 100 %. 2. percentage of agreement between the 3 firing is 100 %. 3. percentage of agreement between the 5 firing is 100 %. group c2 veneering ceramic the results of this group (table 8) showed a relatively high percentage of agreement when comparing the samples inside the group after each firing interval, which means happened after firing. table 8 core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 firing is 100 %. 2. percentage of agreement between the 3 firing is 100 %. 3. percentage of agreement between the 5 firing is 100 %. h college dentistry restorative dentistry group c1 control group (metal core with 0.5mm veneering ceramic thickness): the results of this group (table 7) showed 100 percentage of agreement when comparing the samples inside the group after each firing interval, which means no color firing. the comparison between the group c1 and groups a1, b1 showed that porcelain fused to metal system is not sensitive to firing. : shade results of group a1 (zirconia core with ceramic thickness 0.5 mm) 1. percentage of agreement between the 3 firing is 100 %. 2. percentage of agreement between the 3 firing is 100 %. 3. percentage of agreement between the 5 firing is 100 %. group c2 control group veneering ceramic th the results of this group (table 8) showed a relatively high percentage of agreement when comparing the samples inside the group after each firing interval, which means happened after firing. table 8: shade results of group c2 (metal core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 firing is 100 %. 2. percentage of agreement between the 3 firing is 100 %. 3. percentage of agreement between the 5 firing is 100 %. h college dentistry restorative dentistry group c1 control group (metal core with 0.5mm veneering ceramic thickness): the results of this group (table 7) showed 100 percentage of agreement when comparing the samples inside the group after each firing interval, which means no color changes happened after firing. the comparison between the group c1 and groups a1, b1 showed that porcelain fused to metal system is not sensitive to firing. shade results of group a1 (zirconia core with ceramic thickness 0.5 mm) of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 control group (metal core with 1mm thickness): the results of this group (table 8) showed a relatively high percentage of agreement when comparing the samples inside the group after each firing interval, which means no happened after firing. shade results of group c2 (metal core with ceramic thickness 1 mm) 1. percentage of agreement between the 3 2. percentage of agreement between the 3 3. percentage of agreement between the 5 h college dentistry vol. 2 group c1 control group (metal core with 0.5mm veneering ceramic thickness): the results of this group (table 7) showed 100 percentage of agreement when comparing the samples inside the group after each firing interval, changes happened after firing. the comparison between the group c1 and groups a1, b1 showed that porcelain fused to metal system is not sensitive to firing. shade results of group a1 (zirconia core with ceramic thickness 0.5 mm) of agreement between the 3rd and 5 2. percentage of agreement between the 3rd and 7 3. percentage of agreement between the 5th and 7 (metal core with 1mm the results of this group (table 8) showed a relatively high percentage of agreement when comparing the samples inside the group after each color changes, shade results of group c2 (metal core with ceramic thickness 1 mm) 1. percentage of agreement between the 3rd and 5 2. percentage of agreement between the 3rd and 7 3. percentage of agreement between the 5th and 7 vol. 28(2), june 11 group c1 control group (metal core with the results of this group (table 7) showed 100 percentage of agreement when comparing the samples inside the group after each firing interval, changes happened after firing. the comparison between the group c1 and groups a1, b1 showed that porcelain fused to shade results of group a1 (zirconia and 5th and 7th and 7th (metal core with 1mm the results of this group (table 8) showed a relatively high percentage of agreement when comparing the samples inside the group after each changes, shade results of group c2 (metal and 5th and 7th and 7th group c3 control group ( veneering ceramic thickness zero samples inside the group after interval means happened after a different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm (group groups (zirconia and e.max). table 1. percentage of agreement between the 3rd and 5th firing is 0 %. 2. percentage of agreement between the 3rd and 7th firing is 0 %. 3. 7th firing is 100 %. discussion the effect of veneering ceramic brand on shade and reflection dentine ceramics and ips e.max ceram dentine) used in this study, the metal group veneered with ips classic have a different behavior of color changes from the e.max and zirconia groups veneered with ips e.max ceram which they are undergo a relatively similar behavior of changes . that is mean color shade and even the reflection value affected by the veneering ceramic brand , ips e.max ceram is glass ceramic filled with fluorapatite crystals which does not contain feldspar or leucite that make it more translucent and the ips classic (metal ceramic is more opaque . these differences in optical properties affect the results of this study that is agreed with antonson june 2016 group c3 control group ( veneering ceramic thickness the results of this group (table zero percentage of agreement when comparing the samples inside the group after interval and after 3 means the most dramatically happened after a different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm (group c1 and group groups (zirconia and e.max). table 9: shade results of group c2 (metal core with ceramic thickness 2 mm) 1. percentage of agreement between the 3rd and 5th firing is 0 %. 2. percentage of agreement between the 3rd and 7th firing is 0 %. 3. percentage of agreement between the 5th and 7th firing is 100 %. discussion the effect of veneering ceramic brand on shade and reflection two types of veneering ceramic (ips classic dentine ceramics and ips e.max ceram dentine) used in this study, the metal group veneered with ips classic have a different behavior of color changes from the e.max and zirconia groups veneered with ips e.max ceram which they are undergo a relatively similar behavior of changes . that is mean color shade and even the reflection value affected by the veneering ceramic brand , ips e.max ceram is glass ceramic filled with fluorapatite crystals which does not contain feldspar or leucite that make it more translucent and the ips classic (metal ceramic) is a feldspar is more opaque . these differences in optical properties affect the results of this study that is agreed with antonson (11). group c3 control group (metal veneering ceramic thickness the results of this group (table percentage of agreement when comparing the samples inside the group after and after 3rd and 7th the most dramatically the 5th firing. these results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm 1 and group c2) groups (zirconia and e.max). shade results of group c2 (metal core with ceramic thickness 2 mm) 1. percentage of agreement between the 3rd and 5th firing is 0 %. 2. percentage of agreement between the 3rd and 7th firing is 0 %. percentage of agreement between the 5th and 7th firing is 100 %. discussion the effect of veneering ceramic brand on shade and reflection two types of veneering ceramic (ips classic dentine ceramics and ips e.max ceram dentine) used in this study, the results showed that the metal group veneered with ips classic have a different behavior of color changes from the e.max and zirconia groups veneered with ips e.max ceram which they are undergo a relatively similar behavior of changes . that is mean color shade and even the reflection value affected by the veneering ceramic brand , ips e.max ceram is glass ceramic filled with fluorapatite crystals which does not contain feldspar or leucite that make it more translucent and the ips classic ) is a feldspar is more opaque . these differences in optical properties affect the results of this study that is heffernan (5) the effect metal core with 2mm veneering ceramic thickness): the results of this group (table 9) showed a percentage of agreement when comparing the samples inside the group after 3rd and 5 th firing interval, the most dramatically changes firing. these results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm 2) and from groups (zirconia and e.max). shade results of group c2 (metal core with ceramic thickness 2 mm) 1. percentage of agreement between the 3rd and 2. percentage of agreement between the 3rd and percentage of agreement between the 5th and the effect of veneering ceramic brand on two types of veneering ceramic (ips classic dentine ceramics and ips e.max ceram dentine) results showed that the metal group veneered with ips classic have a different behavior of color changes from the e.max and zirconia groups veneered with ips e.max ceram which they are undergo a relatively similar behavior of changes . that is mean color shade and even the reflection value affected by the veneering ceramic brand , ips e.max ceram is glass ceramic filled with fluorapatite crystals which does not contain feldspar or leucite that make it more translucent and the ips classic ) is a feldspar-based ceramic which is more opaque . these differences in optical properties affect the results of this study that is (5), uludag the effect of core with 2mm ) showed a percentage of agreement when comparing the and 5th firing firing interval, which in color firing. these results showed a different color changes behavior from the less veneering ceramic thickness 0.5mm and 1 mm and from the other shade results of group c2 (metal core with ceramic thickness 2 mm) 1. percentage of agreement between the 3rd and 2. percentage of agreement between the 3rd and percentage of agreement between the 5th and the effect of veneering ceramic brand on two types of veneering ceramic (ips classic dentine ceramics and ips e.max ceram dentine) results showed that the metal group veneered with ips classic have a different behavior of color changes from the e.max and zirconia groups veneered with ips e.max ceram which they are undergo a relatively similar behavior of changes . that is mean color shade and even the reflection value affected by the veneering ceramic brand , ips e.max ceram is glass ceramic filled with fluorapatite crystals which does not contain feldspar or leucite that make it more translucent and the ips classic based ceramic which is more opaque . these differences in optical properties affect the results of this study that is (10) and of j bagh college dentistry vol. 28(2), june 2016 the effect of restorative dentistry 12 the effect of firings number on the shade and the refection repeating firing have a different effect on each type ceramic system, the effect of firing depend on the chemical components of the ceramic system and the way that these components react with heat, many compound are decomposed and a new compounds formed after firing. the ceramic system consist of core, veneering layer and sometime an intermediate layer which have bonding or coloring function , the interaction between these layers different from one system to another, this interaction may give different byproducts when exposed to heat. all these factors could give the ceramic system a unique optical property ( that is depend on the chemical composition)dissimilar to the others, so this phenomenon is one of the explanations of the dissimilar reflection and color changes behavior of each type of ceramic system showed in this study results after multiple firing intervals. according to this study results, there is a direct proportion among three variables: 1. the increase in thickness 2. the color which change toward darker and more reddish color 3. the increase of firing intervals. this relation between these factors may happened because of the increase in the ceramic amount, more amount means more material and metal oxides, needs more heat to react and more time to reach the final shape and properties, this explain the relatively unique reflection behavior of the 2mm thickness. this results agreed with several studies have suggested that metal oxides are not color stable after they are subjected to firing temperatures, and color changes of surface colorants after firing have demonstrated pigment breakdown at firing temperatures (12). it is noticeable when the shade measured of the thickness 2mm of each group, the percentage of agreement between the 3rd and the 5th firings in all group is almost 0% or less than 25%. for the other two ceramics thickness (0.5 and 1 mm) the percentage of agreement between the 3rd and the 5th thickness almost higher, that is mean the color faced less changes. the metal group recorded 100% of agreement between the 3rd and the 5thfirings for both thicknesses 0.5mm and 1 mm that make them extremely different from the 2mm thickness. this study showed that the effect of multiple firing changed the color toward darker and more reddish shades, and that is agreeing with (10, 12). it is clear that the 5th firing is the point at which the specimens undergo most of their changes, and in the next firing interval (7th) there are no huge changes the shade. the explanation may be because most of the decomposition, metal oxides losses, particles fusion and new bonding and by products happened in the early firing cycles and the material couldn't change more, that is an agreement with uludag (10) and disagreed with barghi (13) and seghi (14). the effect of veneering ceramic thickness on shade and reflection the thicknesses of the core and the veneering ceramic are represent the amount of tooth structure reduction during preparation. according to the results of this study, the increase in the thickness of veneering ceramic in the control group (metal core) showed darker or more reddish and brownish color, that is happened with the 2mm thickness of veneering ceramic, the shade was (a3.5) according to the easyshade readings in the 3rd firing (first interval), and for the 0.5 and 1mm veneering ceramic thickness when measured in the same criteria and number of firings(3rd firing ) the shade was (b3) which lighter and yellower . in the last firing interval (the 7th firing) the 2 mm thickness showed an extreme shade change to became (a4), statically that mean a high significance difference from the 0.5 mm and 1 mm thicknesses in the metal group. that is agreeing with dozic (2) and hammad (15). these criteria mentioned and explained by hammad et al.(15) and uludag et al.(10), they have been reported that" an increase in the dentin thickness can cause significant differences in the color of metal ceramics ,this has been attributed to diffuse reflection properties of the opaque ceramic, which have less effect on color as the dentin ceramic thickness increases. in the two other groups (e.max core and zirconia core), the effect of the increase of veneering ceramic thickness became much less than in the metal group and that is clear from the shade measurement of three different thickness (0.5 , 1 and 2 mm ) in the 3rd firing . so, the effect of increase in ceramic thickness on color depend on the brand of the ceramic and contents , the least effect in the ips e.max ceram may be because of its' translucent nature , and the presence of the nanoscale fluorapatite crystals that are responsible for the material’s opalescence and thereby decisively contribute to its aesthetic properties. the material’s opacity (level of transparency) is mainly determined by the larger fluorapatite crystals (scientific documentation of ips e.max ceram). these results are agreed with sithiamnuai et al. (16) who reached to a j bagh college dentistry vol. 28(2), june 2016 the effect of restorative dentistry 13 conclusion" when the thickness of the veneering ceramic was increased in both the brands (vita vm9 and ips e-max ceram), color changes were observed as an increase shade elements". references 1. isgrò g, pallav p, van der zel jm, feilzer aj. the influence of the veneering porcelain and different surface treatments on the biaxial flexural strength of a heat-pressed ceramic. j prosthet dent 2003; 90:46573. 2. dozic a, kleverlaan cj, meegdes m, van der zel j, feilzer aj. the influence of porcelain layer thickness on the final shade of ceramic restorations. j prosthet dent 2003; 90:563-70. 3. mclean jw. evolution of dental ceramics in the twentieth century. j prosthet dent 2001; 85(1): 61-6. 4. wee ag, monaghan p, johnston wm. variation in color between intended matched shade and fabricated shade of dental porcelain. j prosthet dent 2002; 87:657-66. 5. heffernan mj, aquilino sa, diaz-arnold am, haselton dr, stanford cm, vargas ma. relative translucency of six all-ceramic systems. part i: core materials. j prosthet dent 2002;88(1): 4-9. 6. kelly jr, nishimura i, campbell sd. ceramics in dentistry: historical roots and current perspectives. j prosthet dent 1996; 75:1832. 7. jacobs sh, goodacre cj, moore bk, dykema rw. effect of porcelain thickness and type of metalceramic alloy on color. j prosthet dent 1987; 57:13845. 8. lund ps, piotrowski tj. color changes of porcelain surface colorants resulting from firing. int j prosthodont 1992; 5:22-7. 9. jorgenson mw, goodkind rj. spectrophotometric study of five porcelain shades relative to the dimensions of color, porcelain thickness, and repeated firings. j prosthet dent 1979; 42: 96-105. 10. uludag b, usumez a, sahin v, eser k, ercoban e. the effect of ceramic thickness and number of firings on the color of ceramic systems: an in vitro study. j prosthet dent 2007; 9725-31. 11. antonson sa, anusavice kj. contrast ratio of veneering and core ceramicsas a function of thickness. int j prosthodont 2001; 14:316-20. 12. bachhav v, aras m. the effect of ceramic thickness and number of firings on the color of a zirconium oxide based all ceramic system fabricated using cad/cam technology. j advprosthodont 2011; 3:5762. 13. barghi n, lorenzana re. optimum thickness of opaque and body porcelain. j prosthet dent 1982; 48:429-31. 14. seghi rr, hewlett er, kim j. visual and instrumental colorimetric assessments of small color differences on translucent dental porcelain. j dent res 1989; 68(12): 1760-4. 15. hammad ia, stein rs. a qualitative study for the bond and color of ceramometals. part ii. j prosthet dent 1991; 65:169-79. 16. sithiamnuai p, eiampongpaiboon t, shrestha a, suputtamongkol k. the effect of thickness on the contrast ratio and color of veneering ceramics. m dent j 2014; 34 (2):137-43. haitham.doc j bagh college dentistry vol. 27(2), june 2015 the effect of restorative dentistry 6 the effect of glass flakes reinforcement on the surface hardness and surface roughness of heat-cured poly (methyl methacrylate) denture base material haitham t. abdulrazzaq, b.d.s. (1) mohammed mm. ali, b.d.s., m.sc. (2) abstract background: heat-cured poly (methyl methacrylate) the principal material for the fabrication of denture base have a relatively poor mechanical properties. the aim of this study was to investigate the effect of glass flakes used as reinforcement on the surface hardness and surface roughness of the heat-processed acrylic resin material. material and method: glass flakes (product code: gf002) pretreated with silane coupling agent were added to triplex® denture base powder using different concentrations. a total of 100 specimens of similar dimensions (65 x 10 x 2.5) mm were prepared, subdivided into 2 main groups of 50 specimens for each of the study tests. ten specimens for the control group and 40 specimens for each of the experimental groups (2%, 3%, 5%, and 7%) glass flakes content. the surface hardness was evaluated using the shore d hardness test, while the surface roughness was evaluated using a profilometer device that detect the geometry of the specimen unpolished surface. results were analyzed using the wilcoxon rank sum test and the 1-way analysis of variance, (p-value< 0.05). results: the surface hardness tended to increase significantly p 0.05 with the increasing flakes concentration, as an increase of 5.12% was recorded in surface hardness for the highest loading level; while the roughness showed a significant increase that remained within the tolerable range –less than 2µm– (significant bacterial colonization would occur if the surface roughness is more than 2µm). conclusion: the addition of glass flakes to heat-cured poly(methyl methacrylate) enhanced the hardness of the material, the improvement was statistically significant for the higher glass flakes concentrations (5% and7%), while for the surface roughness there were a constant increase in roughness along with the increasing glass flakes content key words: glass flakes, acrylic resin, hardness, roughness. (j bagh coll dentistry 2015; 27(2):6-10). introduction the material most commonly used for the fabrication of dentures complete or partial is heatcured poly (methyl methacrylate) (pmma). this material is not ideal in every respect and it is the combination of virtues rather than one single desirable property that accounts for its popularity and usage; but, it is still far from ideal in fulfilling the mechanical requirements of prosthesis (1).pmma continues to be used because of its favorable working characteristics, processing ease, accurate fit, and stability in the oral environment, superior esthetics and use with inexpensive equipment. despite these excellent properties, there is a need for improvement in the fracture resistance of pmma (2). methods to improve the inherent material properties of pmma have included using alternate polymers such as polycarbonate (3), nylon (4), chemical modification by including butadiene-styrene rubber co-polymers (5,6) and the addition of reinforcing agents including particulates and fibers (7). altering a material by adding functional fillers to improve some of its properties may introduce deleterious effects on other properties; hence the incorporation of glass flakes into pmma attempt (1) master student. department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of prosthodontics, college of dentistry, university of baghdad. ting to improve its fracture resistance may adversely affect other properties such as surface hardness and surface roughness. hardness is broadly defined as the resistance to permanent surface indentation or penetration.hardness is indicative of the ease of finishing of a structure and its resistance to inservice scratching (8). based on this definition of hardness, it is clear why this property is so important in dentistry. it is important that the surface roughness (ra) of materials used for dental prostheses is determined before their use in the mouth. rougher surfaces can cause discoloration of the prostheses, be a source of discomfort to the patient, it contributes to microbial colonization, biofilm formation, and the accumulation of plaque and the adherence of candida albicans (9-11).increased presence of candida species is reported in denture-related stomatitis (12). the intaglio surface of the denture is not polished prior to insertion; the rough areas, areas of imperfections and porosities serve as a breeding ground for opportunistic oral fungi, that's why roughness as a surface property is so crucial for polymers used in the construction of dentures (13). glass flakes, a high aspect ratio reinforcing additive with many commercial applications. glass flakes has been used in many industrial polymers, their manufacturers claim that its addition to some thermoplastics has resulted in a j bagh college dentistry vol. 27(2), june 2015 the effect of restorative dentistry 7 significant improvement in flexural properties and planar reinforcement (14). the current study was conducted to investigate the effect of glass flakes added as a strengthener on the surface hardness and surface roughness of conventional heatprocessed poly (methyl methacrylate) denture base resin. material and method micronised glass flake, surface pre-treated with silane coupling agent as it was ordered from the manufacturer, product code: (gf002). (glassflake ltd, leeds, uk). this consists of flake particles 1.3-2.3µm thick, and a range of diameters of which 88% were below 50µm.triplex® hot (ivoclarvivadent ag, schaan, liechtenstein) was selected as both the control and the agent to be experimented. the glass flake was mixed with the poly (methyl methacrylate) denture base powder, using weight/weight (w/w) ratio14, to be mixed with a constant amount of liquid. the glass flake was added in amounts of 2%, 3%, 5% and 7% by weight of powder, an electronic balance (a&d® hr-200, japan) with accuracy of (0.0001g) was used for this purpose. molds were prepared using dental stone in standard denture flasks, by investing plastic patterns (template) measuring (65x10x2.5) mm. powder and liquid were mixed in accordance to the manufacturer instructions (23.4g/10ml), the mixture was covered and left to mature until dough was reached, dough was packed into the prepared stone molds, trial closure of the flask halves was carried out under 80 bar pressure in a hydrolytic press (bego®, germany) using transparent sheets then final closure of the flask halves was performed and clamped before curing. curing (polymerization) was carried out by immersing the clamped flasks in cold water in a thermostatically controlled water bath (kavo® ewl 5501, germany), heated until boiling temperature (100 c˚), then boiling continued for (45) minutes, this is the standard procedure which is the curing method recommended by the manufacturer. the flasks were left to cool to room temperature before being opened. specimens were finished and polished (except the specimens for surface roughness test)this latter group was designated as "unpolished" and represents the denture intaglio surface which does not undergo any alteration prior to insertion intraorally; finishing and polishing was accomplished in a way similar to that used in the fabrication of complete dentures. testing procedure the specimens used were with dimensions of (65mm x 10mm x 2.5mm) (15) ±0.2mm; specimens were conditioned in distilled water at 37 ˚c for 48 hours before being tested (16). i. surface hardness ten specimens for the control and ten specimens for each glass flakes concentration were prepared to make a total of (50) specimen for the surface hardness measurement.each specimen was indented using compact portable indenter (shore d hardness tester, ht-5610d, china), the equipment generally consist of springloaded metal indenter point (0.8mm diameter) and a gauge from which the hardness was read directly from the digital display. the device was used along with its test block that controls both the direction (leveling) and the amount of the applied force as in (figure 1). according to the device manufacturer’s instructions, the test block must be positioned above the specimen which was supported on a flat surface and the indenter point pressed firmly and in a steady motion through the hole of the test block until metal to metal contact obtained between the head of the device and the test block to apply the same amount of load in the same direction. the first indentation point (test pattern) was carried out 10mm from the specimen edge and it was repeated every ten millimeters along a line that bisects the specimen surface as in (figure 2). five measurements were performed for each specimen, and the average of these measurements was calculated and considered for that single specimen. figure 1: compact portable indenter (shore d hardness tester) with its test block. 10mm 10mm 10mm 10mm figure 2: schematic diagram of the surface hardness test specimen with five test sites. j bagh college dentistry vol. 27(2), june 2015 the effect of restorative dentistry 8 ii. surface roughness ten specimens for the control and ten specimens for each concentration were prepared to make a total of (50) specimen for the surface roughness measurement. each specimen was tested for surface roughness using a portable surface roughness tester (tr220, time high technology ltd., china), which can measure small surface variations by moving a diamond stylus (needleshaped) in contact with the surface, while moving along the specimen surface, measurements were done on the same selected area of each specimen as in (figure 3). the vertical displacement of the stylus was measured as the microgeometry of the surface varies; these measurements were processed, stored and displayed. the tests were performed with a scan length range of 11mm. the device was set at the zero level as the baseline for measurement and for each specimen before performing the surface roughness measurement. surface roughness was measured at 3 positions as in (figure 4) across each specimen surface which was divided into areas (3 equal thirds, 2 at each end and one in the middle), and a final average was then calculated for that specimen. figure 3: profilometer (portable roughness tester) figure 4: schematic diagram of the surface roughness test and the specimen. results surface hardness the control acrylic resin samples (0% glass flakes) exhibited a mean surface hardness of (18.15); when all the mean values of the test groups are compared, there is an obvious trend of surface hardness increase along with the increase in the flakes addition percentage. details are presented in (table 1). table 1: descriptive statistics of the surface hardness test. test group mean s.d. surface hardness control 18.15 0.7230 2% 18.62 0.5245 3% 18.88 0.4442 5% 18.94 0.3438 7% 19.08 0.1686 the one way analysis of variance (anova) was conducted between the test groups to examine sources of variation, as shown in (table 2). table 2: one way anova between the tested groups regarding surface hardness test surface hardness sum of squares df mean square f-test sig. between groups 5.375 4 1.344 5.884 0.001 * within groups 10.277 45 0.228 total 15.652 49 * indicate the presence of statistically significant differences at a level less than 0.05 the wilcoxon test (wilcoxon rank sum test) was conducted to investigate the difference between each two test groups. a statistically significant difference (p<0.05) was found between the control group and the case groups of (3%, 5%, and 7%) and also between the 2% and 7% groups; comparison between all the other groups revealed a statistically non-significant difference (p > 0.05). further details are presented in (table 3). table 3: wilcoxon test between tested groups regarding surface hardness comparison p-value % difference control & 2% 0.221 +2.58% control & 3% 0.038* +4.02% control & 5% 0.036* +4.35% control & 7% 0.012* +5.12% * indicate the presence of statistically significant differences at a level less than 0.05 surface roughness the control acrylic resin samples (0% glass flakes) exhibited a mean surface roughness of (1.3394); when all the mean values of the test groups are compared, there is an obvious trend of surface roughness increase along with the increase in the flakes addition percentage. details are presented in (table 4). j bagh college dentistry vol. 27(2), june 2015 the effect of restorative dentistry 9 table 4: descriptive statistics of the surface roughness test test group mean s.d. surface roughness (µm) control 1.33 0.1793 2% 1.47 0.1314 3% 1.55 0.1303 5% 1.58 0.1050 7% 1.65 0.2020 the one way analysis of variance (anova) was conducted between the test groups to examine sources of variation, as shown in (table 5). table 5: one way anova between the tested groups regarding surface roughness test surface roughness sum of squares df mean square ftest sig. between groups 0.592 4 0.148 6.259 0.000* within groups 1.064 45 0.024 total 1.657 49 * indicate the presence of statistically significant differences at a level less than 0.05 the wilcoxon test (wilcoxon rank sum test) was conducted to investigate the difference between each two test groups. a statistically significant difference (p<0.05) was found between the control group and the case groups of (3%, 5%, and 7%) and also between the 2% and 7% groups; comparison between all the other groups revealed a statistically non-significant difference (p > 0.05). further details are presented in (table 6). table 6: wilcoxon test between tested groups regarding surface roughness comparison p-value % difference control & 2% 0.074 +10.34% control & 3% 0.028* +16.4% control & 5% 0.009* +18.6% control & 7% 0.007* +23.65% * indicate the presence of statistically significant differences at a level less than 0.05 discussion in an attempt to explain these results, one must imitate the micro-structure of the reinforced pmma resin specimens; these specimens are planar structures (having thickness much lower than their other two dimensions i.e. length and width), and during the fabrication of these specimens using the compression-molding technique, a considerable amount of these flakes might align parallel to the specimen's principal plane especially as the flakes approaches the surface, and as these flakes are high aspect ratio fillers, they offer greater opportunity of overlapped surfaces; and since they possess an elastic modulus greater than that of the denture base resin so they are stiffer and deform less than the acrylic matrix. in the result, much more resistance was provided against the penetrating indenter as more glass flakes were incorporated into the acrylic resin samples. this finding agrees with that of al momen (18) who indicated a significant increase in surface hardness when 6.6% of glass fibers were added to pmma matrix. chen et al. (19) stated that the knoop hardness was decreased as compared to the control when glass fibers was added in 1%, 2% and 3% concentrations; they also stated that the most prominent decrease in surface hardness was in the 1% concentration, the issue that may disagree with the results of the current study. the variance in surface roughness might be attributed to the protrusion of flakes from the surface of pmma specimens, since these fillers are micron-sized and as the samples were prepared using the compression-molding; it was assumed that the flakes were spread or forced randomly within the thickness and across the surface of the samples, acquiring different orientations in a more free random manner as they approach the core of the sample; while, as these flakes reach the surface of the specimen they tend to align parallel to each other’s and to the specimen's principal plane; this assumption don’t exclude that a considerable amount of these flakes might take other different random orientations having their edges protruding out of the polymer matrix rendering the surface of the reinforced specimens rougher. it’s worthy to say that, this assumption might occur at higher scale as the concentration of flakes was increased, to explain why the roughness was increased with the increasing glass flakes concentration. references 1. jagger dc, harrison a, jandt kd. the reinforcement of dentures: a review. j oral rehabil 1999; 26:18594. 2. john j, gangadhar sa, shah i. flexural strength of heat-polymerized poly (methyl methacrylate) denture resin reinforced with glass, aramid, or nylon fibers. j prosthet dent 2001; 86:424-7. 3. stafford gd, smith dc. polycarbonatesa preliminary report on the use of polycarbonates as a denture base material. dent pract1967; 17:217-23. 4. hargreaves as. nylon as a denture-base material. dent pract 1971; 22:122-8. 5. rodford ra. the development of high impact strength denture-base materials. j dent1986; 14:214-7. j bagh college dentistry vol. 27(2), june 2015 the effect of restorative dentistry 10 6. rodford ra. further development and evaluation of high impact strength denture base materials. j dent1990; 18:151-7. 7. vallittu pk. a review of fiber-reinforced denture base resins. j prosthodont1996; 5:270-6. 8. powers jm, sakaguchi rl. craig’s restorative dental materials. 12th ed. st. louis: mosby elsevier; 2006; p. 513-553. 9. yamauchi m, yamamoto k, wakabayashi m, kawano j. in vitro adherence of microorganisms to denture base resin with different surface texture. dent mater j1990; 9:19-24. 10. radford dr, sweet sp, challacombe sj, walter jd. adherence of candida albicans to denture-base materials with different surface finishes. j dent1998; 26: 577-83. 11. quirynen m, marechal m, busscher hj, weerkamp ah, darius pl, van steerberghe d. the influence of surface free energy and surface roughness on early plaque formation: an in vivo study in man. j clin periodontol 1990; 17:138-44. 12. barbeau j, seguin j, goulet jp, de koninck l, avon sl, lalonde b, rompre p, deslauriers n. reassessing the presence of candida albicans in denture-related stomatitis. oral surg oral med oral pathol oral radiol endod 2003; 95: 51-9. 13. ramage g, tomsett k, wickes bl, lopez-ribot jl, redding sw. denture stomatitis: a role for candida biofilms. oral surg oral med oral pathol oral radiol endod2004; 98:53-9. 14. franklin p, wood dj, bubb nl. reinforcement of poly (methyl methacrylate) denture base with glass flake. dent mater2005; 21: 365-70. 15. iso 1567:1999. dentistry – denture base polymers. geneva: international organization for standardization; 1999. available at: http://www.iso.ch/iso/en/prods-services/ iso store /store.html. 16. american dental association ada specification no: 12, 1975. 17. american national standard specification for denture base polymers, chicago, 2002. 18. al-momen mm. effect of reinforcement on strength and radio-opacity of acrylic denture base materials. a master thesis, college of dentistry/university of baghdad, 2000. 19. chen sy, liang wm, yen ps. reinforcement of acrylic denture base resin by incorporation of various fibers. j biomed mater res 2001; 58: 203-8. http://www.iso.ch/iso/en/prods-services/ tania.doc j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 98 assessment of the immunohistochemical expression of ebv in oral lichen planus tania abdulelah al-tahan, b.d.s. (1) ahlam hameed majeed, b.d.s., m.sc. (2) abstract background: oral lichen planus (olp) is a chronic immunologic disease. the etiology of olp is unknown, viral antigens (for example ebv) have been proposed as etiologic agents. olp may get transformation to malignancy so research on the presence of these in olp lesions seems to be necessary. the aim of this study was to evaluate ebv expression immunohistochemically in olp. materials and methods: tissue specimens of 30 formalin fixed, paraffin-embedded tissue blocks histologically diagnosed oral lichen planus was performed to evaluate ebv expression. results: expression of ebv was detected in epithelium of (46.6%) in the study samples in (olp). no statistically significant correlation was found with clinical parameters except for a significantly higher expression in females. conclusions: epstein barr viruses were present in considerable amounts in oral lichen planus. taking into account the potential of viruses in olp proving or disapproving or etiological role of viruses in olp is continuously need to be examined in further studies. key words: ebv, lichen planus. (j bagh coll dentistry 2015; 27(2):98-100). introduction oral lichen planus (olp) is a chronic mucocutaneous t-cell mediated immunoinflammatory disease which was first described by erasmus wilson (1869). oral, genital, and some skin types of lp may predispose to the development of squamous cell carcinoma (1). it is estimated to affect 0.5% to 2% of the general population (2), the most commonly affected peoples are middleaged adults of both sexes with slight predilection for women, although it may occur at any age (3) olp may arise anywhere in the oral cavity. the buccal mucosa, tongue and gingiva are commonly affected sites, whereas palatal localization is uncommon. the lesions are usually symmetrical, bilateral or may be multiple. it has a variety of clinical presentations, including reticular, papular, plaque-like, atrophic, and ulcerative forms. (4) the etiology of olp is unknown. an alteration in the basal keratinocytes by certain stimuli that induce humeral and cell mediated immune response has been postulated as a mechanism (5). many variations in the clinical presentation of cutaneous lichen planus have been described (5). oral lesions are reported to have distinct clinical and histological features and characteristic distribution (3). the histopathological features of olp include liquefaction of the basal cell layer accompanied by apoptosis of the keratinocytes, a dense bandlike lymphatic infiltrate between the epithelium (1) master student. department of oral diagnosis, college of dentistry, university of baghdad (2) professor, department of oral diagnosis, college of dentistry, university of baghdad and connective tissue, focal areas of hyperkeratinized epithelium (which give rise to the clinically apparent wickham’s striea) and occasional areas of atrophic epithelium, where the rete pegs may be shortened and pointed.(6) exogenous agents may also alter keratinocyte antigen expression. the response of these specific cd8+t cells is similar to what occurs during a viral infection where a virus can act as a cytoplasmic antigen or induce the expression of host cell proteins, resulting in an altered host cell protein profile (8). therefore, it is of interest to investigate the possibility of viral involvement in the pathogenesis of olp. the epstein-barr virus, a member of the human. (9) approximately 90% of adults have demonstrable ebv antibodies. in-vivo, the infection is restricted to 2 target cells, the oronasopharyngealor the salivary gland epithelium and b-cell lymphocytes. ebv has the ability to establish a latent infection, which means a silent state of viral infection, characterized by a low expression of viral genes and minimal cytopathic effects or production of infectious virus. ebv is associated with infectious mononucleosis and oral hairy leukoplakia and with burkitt lymphoma and nasopharyngeal carcinoma. (10). materials and methods tissue specimens thirteen tissue samples of paraffin embedded blocks histologically verified as oral lichen planus were randomly chosen from the archives of oral pathology department, college of dentistry, baghdad university. j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 99 immunohistochemical staining five-micrometer thick sections of formalin fixed and paraffin embedded biopsy samples were processed by the avidin-biotin-peroxidase complex (abc) method. deparaffinization and rehydratation of the sections were followed by the blocking of endogenous peroxidise activity with incubating the sections in 3 % h2o2 for 10 minutes. after rinsing with phosphate buffered saline (pbs, ph:7.0), non specific binding was reduced with protein blocking serum for 10 minutes. sections were incubated with herpes simplex virus type 1 primary antibody(hsv i polyclonal antibody) , epstein barr virus primary antibody (ebv/lmp1 monoclonal antibody at room temperature for 60 minutes. after rinsing with pbs, the slides were incubated with biotinylated secondary antibody for 30 minutes. the sections were washed with pbs and then the slides were incubated with label (streptavidin peroxidise, lab vision) for 30 minutes. .then used chromogen for visualization of the antibody binding. finally, the sections were counter stained with mayer’s haematoxylin, cleared and mounted. results evaluation of ebv immunohistochemical expression immunostaining of ebv was detected as a brown staining in the cytoplasim of cells, in olp cases positive ihc expression was found in 14 cases (46.66%).fig (1) figure 1: positive brown cytoplasim immunostaining of ebv olp (40x). three cases showed nuclear expression and were not counted as positive as recommended by the antibody manufacturer’s data sheet. as shown in fig (2). figure 2: positive brown nuclear immunostaining of ebv in olp (40x). according to spearman correlation and person correlation test , the results of this study in olp showed statistically non significant correlation regarding ebv expression in relation to the age (p-value =0.098) for person, (p-value =0.087) for spearman, and to the clinical presentation (pvalue=0.127) for person,(p-value=0.174) for spearman statically non-significant. while for sex statistically significant correlation (p-value=0.039) was showed as clarified in table (1.2.3). table 1: ebv expression as related to age age groups score 0 score 1 score 2 score 3 score 4 20-29 1 0 0 1 1 30-39 3 0 0 0 2 40-49 5 0 1 2 1 50-59 5 1 0 0 2 60 2 0 0 3 0 total 16 1 1 6 6 pearson correlation=0.654, p-value=0.098* ns spearman correlation=0.662, p-value=0.087* ns table 2: ebv positivity as related to sex gender score0 score1 score2 score3 score4 male 7 0 1 0 0 female 9 1 0 6 6 total 16 1 1 6 6 pearson correlation=0.478, p-value=0.039 *s spearman correlation=0.462, p-value=0.028* s table 3: ebv positivity as related to type. type score0 score 1 score 2 score 3 score 4 reticular 10 1 0 6 5 erosive 6 0 1 0 1 total 16 1 1 6 6 person correlation=0.234, p-value=0.127* ns spearman correlation=0.334, p-value=0.174*ns j bagh college dentistry vol. 27(2), june 2015 assessment of the oral diagnosis 100 discussion ebv has the ability to establish a latent infection, which mean a silent state of viral infection, characterized by a low expression of viral genes and minimal cytopathic effects or production of infectious virus, the association between ebv and premalignant and malignant disorders has been studied for the oral region. some authors consider olp to be premalignant lesions, but the premalignant potential of olp remains controversial (10). regarding the possible premalignant potential of olp, in any cases, the premalignant potential of olp can not be ruled out. in the present study the number of olp cases that were positive for ebv was 14 (46%). high ebv prevalence in olp in some studies (9,10) might be due to a decrease in the immune defense, locally or generally. studies on immunecompromised patients seem to support this theory, because they show a higher prevalence of ebv, even in clinically normal oral mucosa (11).this study show higher positivity than yildirim study in 2011 in this study show 3 cases with nuclear positivity, were not counted as positive as recommended by the antibody manufacturer’s data sheet, this expression attributed to ebv lmp1 localization ,lmp1expressing show three patterns; aggregated patches in the membrane ,diffused expression in the nuclei ,and mixture of these three form (8), these results show that lmp1 has distinct plasma membrane and intracellular localization in different ebvpositive cell lines and that the heterogeneous distribution an inheretant feature (11). observed specific ebv in some olp specimens suggested that ebv may be involved in the pathogenesis of some oral lesions. these high variability and inconsistency probably reflect geographical difference as well as differences in methodological sensitivity (12). horiuch et al 1995 shows that ebv could be one of the normal flora component of their mouth and higher prevalence of ebv in their country. three theories for the presence of ebv in oral premalignant and malignant lesions have proposed: [i] ebv infection may be involved in the carcinogenesis of oral squamous cell epithelium; [ii] ebv easily infects squamous cell carcinoma cells [iii] ebv exists in cancer cells as a passenger. (13) references 1. horiuchi k, mishima k, ichijima kk, sugimura m, ishida t, kirita t. epstein-barr virus in the proliferative diseases of squamous epithelium in the oral cavity. oral surg oral med oral pathol oral radiol endod 1995; 79(1): 57-63. 2. eisen d. the clinical features, malignant potential and systemic associations of oral lichen planus a study of 723 patients. dermatology research association. j am acad dermatol 2002; 46: 207-14. 3. elazebith vl, brieva j, schachter m, west le. successful treatment of erosive lichen planus with topical tacrolimus. arch dermatol 2001; 137: 142-5. 4. al-anni lsy. oral lichen planus clinical study with the clinicopathological correlation in the diagnosis of o.l.p. j bagh coll dentistry 2005; 17: 57-60. 5. abbas k, lichtman ah. immunity to microbes, in cellular and molecular immunology, chapter 15, pp. 345–366, wb saunders, philadelphia, pa, usa, 5th ed. 2004; 37(5): 338-43. 6. tsu-yi, fire son dp, wells m, et al. lichen planus. e medicine 2005; 1-33. 7. fitzpatrick tb, freed berg im, arthur z e, klaus w, austen kk, lowell a, smith g, katz si. lichen planus: fitzpatrick's dermatology in general medicine. 6th ed. mc graw-hill 2003. p. 463-77. 8. james flanagan, jaap middeldorp and tom sculley. localization of ebv protein lmp1 to exosomes. j general virol 2003; 84: 1871-9. 9. katta r. lichen planus. baylor college of medicine, houston, texas am fam physician 2000; 61(11): 3319-28. 10. sahebjamee m, eslami m, jahanzad i, babaee m, kharazani tafreshi n. presence of epsteinbarr virus in oral lichen planus and normal oral mucosa. iranian j publ health 2007; 36(2): 92-8. 11. jingwu xu, ali ahmed and jose menezes. pereferantial localization of ebv oncoprotein lmp1 to nnclei in human t-cells.laboratory of immunology, department of microbiology and immunology. university of montreal and ste-justine hospital, canada h3t 1c5 2002; 76: 4081. 12. meij ebv, schepman k, smeele l, waal jvd, bezemer p, waal ivd. a review of the literature regarding malignant transformation of oral lichen planus. oral surg oral med oral pathol oral radiol endod 1999; 88(4): 307-10. 13. pedersen a. abnormal ebv immune status in oral lichen planus. oral dis 1996; 2(2): 125-8. الخالصة تھدف . ة كأحد االسباب المرضی ebvو یفترض فایروس ال . یعد الحزاز الفموي المنبسط من احد االمراض المناعیة المزمنة غیر معروفة االسباب: لخلفیةا .في عینات الحزاز الفموي المنبسط ebvفایروس الدراسة الى تقییم الظھور النسیج المناعي ل عن طریق االجسام المضادة في ثالثین عینة من الحزاز الفموي المنبسط محفوظة في ebvالكیمیائي النسیجي المناعي لفایروس تم تقییم الظھور :طرق البحث .الفورمالین ومغمورة بشمع البارافین ظھور الفایروس مع المتغیرات السریریة باستثناء لم یتم ایجاد اي عالقة ل .من الحاالت المدروسة% 46,6في ebvاظھرت الدراسة وجود فایروس :النتائج .وجوده بشكل اكبر في االناث وبداللة معنویة .من الممكن اجراء دراسات اخرى لتأكید دور الفایروس في نشأة المرض. بشكل ملحوظ في الحزاز الفموي المنبسط ebvیتواجد فایروس : االستنتاجات wesal f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 dental caries pedodontics, orthodontics and preventive dentistry174 dental caries and salivary interleukin-6 among preterm postpartum women in relation to baby birth weight (comparative study) dhamiaa m. tajer, b.d.s. (1) wesal a. al-obaidi, b.d.s., m.sc. (2) abstract background: the physiologic, biochemical and anatomic changes that occur during pregnancy are extensive and may be systemic or local. however, most of these changes return to pre pregnancy status six weeks postpartum. the aim of the study was to investigate the effect of dental caries among preterm postpartum women and it's relation to baby birth weight and salivary interleukin-6 (il-6). materials and methods: 66 postpartum women were examined, 33 preterm postpartum women (study group) and 33 full term postpartum women (control group). dental caries was recorded using, decayed, missing and filled surfaces index, also assess the decayed lesion by severity. salivary samples were taken from all subjects to estimate salivary il6 levels. babies' birth weight also was measured. results: data of the present study showed a higher caries severity among study group compared to control group, with no statistically significant difference (p> 0.05). for both groups, the initial decayed surface d2 was the lightest value for both groups. while the deep frank cavitations d4 was the lowest in study group with no data recording among control group. the result revealed highly significant difference in baby birth weight between the two groups. the correlation between ds and salivary il-6 was highly significant, and a significant correlation noticed between d3 and salivary il-6 in study group. in control group, a highly significant positive correlation was detected between baby birth weight and dmfs, and a significant correlation was obscured between baby birth weight with decayed surface, also a significant correlation was found between salivary il-6 and decayed surface in the same group. conclusion: during pregnancy, a woman may be particularly amenable to disease prevention and health promotion interventions that could enhance her oral health on that of her infant's, due to the potential associations between oral health and preterm delivery and baby birth weight. keywords; dental caries, salivary il-6, preterm postpartum women, baby birth weight. (j bagh coll dentistry 2013; 25(special issue 1):174-177). introduction dental caries is an infections micro biological disease that results in localized dissolution and destruction of the calcified tissue of teeth (1) . dental calcium is present in a stable crystalline form and is not mobilized during pregnancy to supply fetal demand as in bone calcium, since no histological evidence that calcium can be removed from erupted teeth during pregnancy was reported (2). hill et al (3) proposed that oral bacteria might reach aminotic fluid and influence foetuses via haematogenous spread, giving rise to suspicious that chronic inflammatory processes in the oral cavity such as periodontitis might influence pregnancy. so, this association must be further explored in observational and intervention studies to establish whether it is causal in nature or incidental and to determine the possible benefits of intervention and the potential to generalize the finding in diverse populations. in iraq, some studies regarding the assessment of dental carries among pregnant women were reported (4-7). (1) master student. department of pedodontics and preventive dentistry, dental college, university of baghdad. (2) professor, department of pedodontics and preventive dentistry, dental college, university of baghdad. yet, no previous studies were established to found the relation between dental caries and salivary il-6 among preterm postpartum women with baby birth weight, so for this reason this study was designed. materials and methods dental caries was recorded from 66 postpartum women with an age rang at 20-25 year old, 33 preterm postpartum women (study group ppw) and 33 full term postpartum women (control group fpw), selected from the different maternity wards in baghdad. dental caries was recorded by using decayed, missing and filled surfaces index according to the criteria described by world health organization 1987 (8) and d1-4 criteria by muhelmman (9) to assess the severity of decayed lesion. saliva samples were collected from all samples and collected in plastic tubes after stimulation by chewing arabic gums, then centrifuged at 4000 rpm for 30 minutes, the clear supernatant was separated by micro pipette, stored at (-20◦c) in a deep freeze till being assessed. the expected day of delivery (edd) was calculated by counting back 3 months and adding 7 days to the first day of last menstrual period (10) . baby weight was measured by taking the baby with his light cloths and the weight was measured carefully. j bagh college dentistry vol. 25(special issue 1), june 2013 dental caries pedodontics, orthodontics and preventive dentistry175 mean and standard deviation (sd) were calculated. spearman`s correlation coefficient and student`s t-test were used for statistical analysis, at level of significance 0.05. results table (1) demonstrates the mean values of dmfs index and by the fractions among both groups. it showed that the mean values of ds, ms, fs and dmfs were higher among preterm postpartum women (ppw) than that among full term postpartum women (fpw) with no statistically significant difference (p > 0.05). the mean values of dental caries by grades of lesion severity (d1-4) were illustrated in table (2). the ppw had a higher grade of (d1-4) than that of control group, statistically no significant difference was found between the two groups. table (3) shows the mean and sd of baby birth weight (bbw) among the two groups. a highly significant difference was noticed between them. the correlation coefficient between bbw and salivary il-6 is seen in table (4). it is cleared that a weak negative correlation was found between salivary il-6 and bbw in study group, while among control group it was weak positive correlation. however, statistically this correlations were recorded to be not significant (p>0.05). tables (5 and 6) show the correlation between salivary il-6 and bbw with dental caries severity among both groups. a highly significant positive correlation was detected between salivary il-6 and ds, also a significant positive correlation was noticed between salivary il-6 and d3. on the other hand, the relation between bbw and (ds, ms, dmfs, d1, d2 and d3), and between salivary il-6 with ms and d1, were weak negative correlation. but the correlation between bbw with fs and d4 and between salivary il-6 with dmfs, d2 and d4, were weak positive correlation. while the correlation between salivary il-6 and fs was strong negative correlation. all these correlations statistically were not significant (p>0.05). it could be noticed that a highly significant positive correlation was observed between bbw and dmfs, also a significant correlation were noticed between bbw and salivary il-6 with ds. on the other hand, weak negative correlations were detected between salivary il-6 with ms and fs and between bbw with fs, d1 and d3. while the relation between bbw with ms and d2 were weak positive correlations, and the same between salivary il-6 with dmfs, d1, d2 and d3. discussion caries is a multifactorial disease; it is a complicated process depends on many factors (11, 12). result of the present study showed that (ppw) had a higher caries intensity (dmfs) than that among control group, but the difference was statistically not significant. for both groups, decated surface (ds) was the major component of dmfs index followed by (ms) then filled surface (fs). this indicates that those women received less dental care during their pregnancy and that they had a more caries teeth and even when treatment was applied it was directed toward tooth extraction rather than conserving the tooth. this might had to the popular notions that pregnancy leads to tooth loss (“a tooth for every pregnancy”) (6, 13). no statistically significant difference was observed between both groups regarding dmfs mean value. this might be attributed to the accumulative nature of dental caries. so, no difference between women who deliver preterm and full term. this result agrees with buduneli et al study (14), in which no statistically significant difference among study and control groups regarding number of teeth mean value and number of teeth with restoration mean value. in this study, the initial decayed surfaces (d2) were found to be the highest, while frank cavitation (d4) was the lowest in occurrence among both groups with no statistically significant difference was found between the two groups. this is due to that dental caries is a chronic disease; it may need years to progress, unfortunately, no previous studies were available to compare with, therefore, further studies are needed regarding preterm delivery in relation to dental caries. highly significant difference was found in bbw between study and control groups. this result could be attributed to the fact that low birth weight is very closely related to preterm birth as it is estimated that approximately 50% of preterm infants weight less than 2500 g, whereas only 2% of full term infant's weight below that threshold (15). also babies are born with a wide range of birth weight, while those born prematurely are more likely to be low birth weight (10, 16, 17) .the present study improved that in the study group a negative correlation was detected between bbw and salivary il-6, this result may due to produce of mean inflammatory cytokines, although produced with the intention to compact the infection, also may cause tissue destruction. because the structural integrity of the placenta is vital for the normal exchange of nutrients between the fetus and the mother, this placenta tissue damage contribute to impaired fetal growth could lead to lbw (18-20). j bagh college dentistry vol. 25(special issue 1), june 2013 dental caries pedodontics, orthodontics and preventive dentistry176 from other side, the relation between bbw and dmfs was positive and highly significant for the second group, this could be explained by, the second group as documented (21) pregnancy may be accompanied by increased dental caries incidence, this is due to that, the number of certain salivary cariogenic microorganisms as streptococcus mutans and lactobacilli may increase during pregnancy, concurrently with a decrease in salivary ph and buffer effect which may predispose to tooth decay (4, 22, 23). also alterations in the psychology, behavior with a tendency toward decreased of personal care have been confirmed during pregnancy (24). furthermore, increased appetite and craving for unbalanced meal with frequent snacking on candy or other decayedpromoting diet all are sharing in placing pregnant women at high risk towered developing dental caries, also will increase pregnant weight gain and this will lead to increase bbw (10, 17, 25). any infection that may cause chorioaminonitis resulting in increase cytokine and prostaglandin levels in the aminotic fluid leads to premature rupture and the initiation of birth (18, 19, 20). highly significant correlation was found between salivary il-6 and ds among study group which was higher than that seen in control group which was a significant correlation also, a significant correlation was found between salivary il-6 and d3 among study group which was also higher than that seen among control group which was a positive correlation. unfortunately, no previous studies were available to compare with. therefore further studies regarding these variables are needed. references 1. peter s. essentials of preventive and community dentistry. 2nded. new delhi: garya gani; 2004. 2. little j, falace d, miller c, rhodus n. dental management at the medically compromised patient. 5th ed. mosby, vsa. 1997: 434-42. 3. hill g. preterm birth: association with genital and possible oral microflora. j perio 1998; 3: 222-232. 4. sulaiman a. oral health status and cariogenic micro flora during pregnancy. a master thesis, college of dentistry, university of baghdad, 1995. 5. alguboory i. evaluation of dental health, knowledge, attitude and oral health status of pregnant women in baghdad city. a master thesis, college of dentistry, university of baghdad, 1999. 6. yas b. evaluation of oral health status, treatment needs, knowledge, attitude and behavior of pregnant women in baghdad governorate. a master thesis, college of dentistry, university of baghdad, 2005. 7. alzaidi w. oral immune protein and salivary constituents in relation to oral health status among pregnant women. ph.d. thesis, college of dentistry, university of baghdad, 2007. 8. who: oral health surveys. basic methods. 4th. geneva, 1987. 9. muhlemann h. oral epidemiology-caries. in: introduction to oral preventive medicine. buch-und zeitschriften-verlag, die quintessenze. 1976. 10. raju g. textbook of obstetrics. 3rd ed. new delhi: s. chand and company ltd. ram nagar; 1996: 51-58, 409445. 11. harris n. introduction to primary preventive dentistry. 4th ed. apple ton and lange, vsa. 1995: 1-15. 12. thylstrup a, fejerskov o. clinical cariology, 4th ed. copenhagen: munksgaard; 1996: 11-15. 13. steinberge b. j. women oral health tissue. j dent educ 1999; 63(3): 271-275. 14. buduneli n, baylas h, budunli e, turkogiu o, kose t, dahlen g. periodontal infections and preterm low birth weight: a case control study. j clin perio 2005; 32: 174-181. 15. nault f. infant mortality and low birth weight, 19751995. health rep 1997; 9: 39-46. 16. aljstair w, kevin p, ian r. obstetrics lh untreated. churchill livingstone; 1997. 17. james n, brian a. clinical obstetrics and gynecology. saunders, houdon. 2004: 293-380. 18. yoon b, romero r, pank j, kim y, kim j, kim k. microbial invasion of the amniotic cavity with ureaplasma ureaalyticum is associated with a roust host response in fetal, amniotic and maternal compartments. am j obstet gyn 1998; 179:12541260. 19. lewis d, barrilleaux p, wang y, adair c, baier j, kruger t. detection of interleukin-6 in maternal plasma predicts neonatal and infections complications in preterm premature rapture of membranes. am j perio 2001; 18: 387-391. 20. keelan j, blumensterin m, helliwell r, sato t, marium k, mitchell m. cytokines, prostaglandin and parturitionareview. plasma. 2003; 24 (suppl. a): 3346. 21. laine m. effect of pregnancy on periodontal and dental health. acta odontol scan 2002; 60: 257-264. 22. vadikas g, lianos c. correlation between pregnancy and dental caries. hell stomatol chron 1998; 32: 267272. 23. soderling e. influence of maternal xylitol consumption on acquisition of mutan streptococci by infants. j den res 2000; 79: 882-7. 24. machuca g, khoshifez o, bullon p. the influence of general health and socio-cultural variables on the periodontal condition of pregnant women. j perio 1999; 70: 785-799. 25. balgojevic d, brkanic t, stojic s. oral health in pregnancy. med pregl 2002; 55: 213-6. j bagh college dentistry vol. 25(special issue 1), june 2013 dental caries pedodontics, orthodontics and preventive dentistry177 table 1: caries severity dmfs and its components among preterm and full term groups. groups ds sig. ms sig. fs sig. dmfs sig. mean ± sd mean ± sd mean ± sd mean ± sd preterm 6.585 5.52 n.s. 6.79 12.62 n.s. 0.97 1.99 n.s. 14.70 14.02 n.s. full term 5.94 4.80 5.30 9.51 0.58 1.41 11.79 10.46 table 2: decayed surfaces by severity among preterm and full term groups groups d1 sig. d2 sig. d3 sig. d4 sig. mean ± sd mean ± sd mean ± sd mean ± sd preterm 2.58 2.62 n.s. 3.82 3.17 n.s. 1.88 2.97 n.s. 0.18 0.77 n.s. full term 2.70 2.26 3.15 2.74 1.21 2.76 0.00 0.00 table 3: baby birth weight among preterm and full term groups groups bbw (gram) sig. mean ± sd preterm 1848.48 371.75 t =16.72* full term 3284.85 324.39 *p< 0.01, d.f = 64 table 4: correlation coefficient between salivary il6 and baby birth weight among preterm and full term groups groups bbw preterm salivary il-6 r = 0.03 p = 0.83 full term salivary il-6 r = + 0.02 p = 0.88 table 5: correlation coefficient between caries severity and salivary il-6 and baby birth weight among preterm group salivary il 6 bbw ds r = + 0.44** p = 0.009 r = 0.12 p = 0.49 ms r = 0.12 p = 0.48 r = 0.10 p = 0.55 fs r = 0.89 p = 0.62 r = + 0.22 p = 0.21 dmfs r = + 0.15 p = 0.38 r = + 0.11 p = 0.53 d1 r = 0.08 p = 0.62 r = 0.01 p = 0.92 d2 r = + 0.18 p = 0.29 r = 0.18 p = 0.29 d3 r = + 0.41* p = 0.01 r = 0.01 p = 0.93 d4 r = + 0.01 p = 0.95 r = + 0.23 p = 0.19 *significant correlation, n=33 ** highly significant correlation, n=33 table 6: correlation coefficient between caries severity and salivary il6 and baby birth weight among full term group salivary il 6 bbw ds r = + 0.40* p = 0.02 r = 0.39* p = 0.02 ms r = -0.10 p = 0.57 r = + 0.29 p = 0.09 fs r = -0.12 p = 0.47 r = 0.02 p = 0.87 dmfs r = + 0.07 p = 0.67 r = + 0.45** p = 0.009 d1 r= + 0.10 p = 0.56 r = 0.05 p = 0.75 d2 r = + 0.09 p = 0.58 r = + 0.33 p = 0.06 d3 r = + 0.18 p = 0.30 r = 0.01 p = 0.91 *significant correlation, n=33 ** highly significant correlation, n=33 bashar.doc j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 78 a comparative study of clinicopathological and immunohistochemical expression of cd1a, rank and rankl in langerhans cell histiocytosis of jaw and skull lesions alyaa kadhim mohammed, b.d.s. (1) bashar hamid abdullah, b.d.s., m.sc., ph.d. (2) abstract background: langerhans' cell histiocytosis (lch) is a group of conditions affecting the reticuloendothelial system. it includes letterer-siwe disease, hand-schuller-christian disease and eosinophilic granuloma and most often presents in childhood. materials and methods: twenty-five cases of lch were diagnosed histologically and confirmed by cd1a antibody and assessed immunohistochemically using anti-rankl and anti-rank antibodies to evaluate osteoclastogenic mechanism. results: regarding jaw cases, there was a significant correlation between cd1a and rank (p=0.016). while in the skull, highly significant correlation existed between rank and rankl (p=0.001). among the sites, there was no statistically significant difference found for each the immunohistochemical markers used. conclusion: lch of jaws and skull bear similar osteoclastogenic mechanism when quantified with rank and rankl immunostaining respectively. with a significant correlation between cd1a and rank for jaw cases, while in the skull lesions, there was a high significant correlation between rank and rankl. keywords: langerhans cell histiocytosis (lch), receptor activator of nuclear factor kappa-b ligand(rankl), receptor activator of nuclear factor kappa-b (rank),cluster of differentiation(cd1a), langerhans cells(lcs). (j bagh coll dentistry 2016; 28(1):78-83). introduction langerhans cell histiocytosis (lch) is a clonal proliferation of langerhans cells (lcs) occurring as an isolated lesion or as a part of systemic (multifocal) proliferation. it affects children as well as adults, presenting with a heterogeneous clinical picture ranging from involvement of a single organ system, primarily skin or bone, to multiple organ systems complicated by organ dysfunction (1). radiologically, lch is characterized by destructive osteolytic lesion, edges of which may be beveled, scalloped or confluent (geographic), or show a “button sequestrum” (2). cd1a, is a specific marker for lcs, it used in the histological comparison of jaw and skull lesions of lch. rankl is a potent osteoclastogenic factor that, exists as a type ii homotrimeric protein and is expressed as a membrane-bound protein on the surface of osteoblasts, osteocytes and marrow stromal cells. in addition, activated t cells secrete rankl as a soluble molecule. rankl binds to its receptor rank, present at the surface of osteoclast precursors and mature osteoclasts, inducing osteoclast formation and activation (3). (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. studies concerning immunehistochemical expression of rank and rankl as markers for osteoclastogenesis of bone in lch are very limited for this reason the present research is aiming to assess histological behavior difference of lch in the craniofacial region in relation to rank and rankl based on cd1a labeling index. materials and methods 25 lch specimens, including 13 cases in the jaws, 9 were in the mandible, 4 in the maxilla, 1 case was in both jaws and 11cases were in the skull. monoclonal mouse anti-human cd1a [7a7 abcam] antibody was used to confirm the diagnosis. monoclonal mouse anti-rank antibody [64c1385 abcam] and monoclonal mouse anti-rankl antibody [12a668 abcam] used to assess the osteoclastogenic mechanism. immunohistochemistry: paraffin sections were reacted with cd1a (1:1000), rankl (1:115), and rank antibodies (1:100) dilution. to evaluate rankl, rank, and cd1a staining, tumor cells exhibiting positive staining on cell membranes and in cytoplasm were counted in at least 5 representative fields (400xmagnification) and the mean percentage of positive tumor cells was calculated. cd1a: labelling index (li) = (number of positive cells/1,000) × 100. labeling index of j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 79 those fields were considered to be the labeling index for the case (4). rankl: 0 (≤10%), 1(11–50%), 2 (51–75% ) and 3 (>75%) immunostained cells (5). rank: cases in which the proportion of positive cancer cells was (≥50%) were positive, and those containing (<50%) positive cells were negative (6). results clinical description the age range of the patients was between 2.550 years with the mean of (23.61±12.17) in the jaw bones. while in the skull, was between 2-35 years with the mean of (11.32±10.28), there was a high significant difference according to age between the two sites. according to gender distribution, the jaw cases comprising 12 males, and 2 females, to give a total male/female ratio of (6:1). while the skull cases comprising 6 males, and 5 females to give (1.2:1), there was no significant difference according to genders between the two sites (table 1). histopathological findings histologic examination of hande stained slides showed numerous histiocytic cells. these histiocytes were large cells with elongated, irregular nuclei, prominent nuclear grooves, giving them typical “coffee been”appearance having a moderate amount of homogeneous, pink, granular cytoplasm and distinct cell margins. the background showed lymphocytes, giant cells and a variable numbers of eosinophils. mitotic figures, were observed in 8 of total 14 cases of lch in jaws and in 4 of total 11cases in skull lesions. spearman's correlation showed that there was no significant correlation between cd1a, rank, rankl and mitoses in each group (table 2). immunohistochemical findings: cd1a immunoreactivity was recognized in all 25 cases of lch. in the jaws, the mean of labeling index was (37.21±19.60), while in the skull(38.64±17.33). comparatively, using mannwhitney u test, there was no statistically significant difference of the expression of cd1a between the two sites of lch (table 3). in the skull, all cases were positive for rankl, with the mean (56.36±14.85).while in the jaws, 13cases was positive, with the mean (51.79±21.45).comparatively, there was no statistically significant difference of rankl expression between the two sites (table 4). in the jaws, 10 cases of lch were positive for rank, with the mean (60±16.98).while in the skull, 10 cases were positive, with the mean (67.27±10.34). comparatively, there was no statistically significant difference between rank positivity between the two sites (table 5). correlations among immunohistochemical markers using spearman's correlation; for the jaws, there was a significant correlation between cd1a with rank (p=0.016). while in the skull, a high significant correlation between rank with rankl (p=0.001) as shown in table (6). table 1: frequency distribution and percentage of age and genders age group jaws skull genders frequency frequency frequency males females <10 1 6 12 6 10-19 5 4 2 5 20-29 5 0 male/female ratio 30-39 1 1 6:01 1.2:1 40-49 1 x2 2.968 501 continuity correction 1.624 d.f. 1 p-value 0.203 (ns) no. of cases jaws skull total 14 11 25 mean 23.61 11.32 18.2 s.d. 12.17 10.28 12.77 min. 2.5 2 2 max. 50 35 50 mann-whitney u test -2.606 p-value 0.009 ** j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 80 table 2: relation between the variables in cd1a, rankl and rank in the jaws and skull markers site % of cells no. of mitoses cd1a jaws r -0.44 p-value 0.11 (ns) skull r -0.11 p-value 0.74 (ns) rankl jaws r -0.11 p-value 0.72 (ns) skull r -0.03 p-value 0.94 (ns) rank jaws r 0.36 p-value 0.21 (ns) skull r 0 p-value 1 (ns) table 3: descriptive statistics and site comparison in cd1a marker variables site descriptive statistics site comparison mean s.d. s.e. mannwhitney u test p value sig. % of cells for cd1a jaw 37.21 19.60 5.24 -0.44 0.66 ns skull 38.64 17.33 5.23 table 4: descriptive statistics and site comparison in rankl marker variables site descriptive statistics site comparison mean s.d. s.e. mannwhitney u test p value sig. % of cells for rankl jaw 51.79 21.45 5.73 -0.33 0.741 ns skull 56.36 14.85 4.48 table 5: descriptive statistics and site comparison in rank marker variables site descriptive statistics site comparison mean s.d. s.e. mannwhitney u test p value sig. % of cells for rank jaw 60 16.98 4.54 -0.81 0.419 ns skull 67.27 10.34 3.12 table 6: correlations among immunohistochemical markers jaws skull variables rank rankl rank rankl cd1a r 0.627 0.056 -0.121 -0.222 p-value 0.016 (s) 0.850 (ns) 0.723 (ns) 0.512 (ns) rank r 0.070 0.852 p-value 0.811 (ns) 0.001 (hs) discussion langerhans cell histiocytosis is by far the commonest of the histiocytoses, is one of the rarest bone tumors representing less than 1% of them. bone involvement is seen in 80-100% of lch patients. in this study, there was a male predominance, these findings were in agreement with other studies (7,8), where all showed a slight to pronounced male predominance, while disagrees with others (9,10), all demonstrated that females and males were equally affected, with a female predominance in pulmonary (lch) cases, with approximately (5:3) ratio. in this study, the mean age of all cases was lower than those demonstrated by previous researchers (11,12), who described a mean age above 30 years. this study showed that there was no significant correlation in the expression values of cd1a, rank, rankl and mitotic figures between jaws and skull lesions. these findings support that the lch is a locally infiltrative neoplasm with frequent pleomorphism and no abnormal mitotic figures j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 81 figure 1: a: h&e stained photomicrograph of a jaw lch (40x). b: positive control ''normal brain tissues'' for cd1a. c&d: positive control ''tonsillar hyperplesia'' for rankl&rank. e&f: cd1a stain (40x objective) demonstrating positive membrane staining of lesional histiocytes in a skull lch (40x&10x).g&h: positive cytoplasmic immunostaining to rankl antibody in a jaw lch(40x&10x), pointer showed a mitotic figure. i&j: positive cytoplasmic immunostaining to rank antibody in a skull lch (40x&10x). j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 82 pleomorphism and no abnormal mitotic figures were seen. this results in accordance with bank et al., (13) who observed mitotic figures in 34 of 61 evaluated specimens based upon ki-67 expression, the presence of mitotic figures indicate that local proliferation contributes to the accumulation of lcs, and a level of ki-67 expression was lower than that of neoplastic tissue. rankl expression in this study indicated that the tumor cells acts as a source of this osteoclastogenic factor. this consistently seen in jaw and skull lesions of lch, which may indicate that ranklproducing tumor cells had the potential to induce osteoclastogensis that account to aggressive behavior and recurrence of lch in both sites. egeler et al., (14) showed that the environment in which the mononuclear cells are present determines their differentiation into the various mononuclear phagocyte system-derived cells. in this study, there was a statistically significant relationship between cd1a and rank, concerning jaw bones alone, that means the expression of rank would be increased with increased number of tumor cells. specifically cd1a+ve lcs which led to local infiltrative activity of lch lesions and bone resorption. egeler et al., (14) had extended the analysis of cytokines to those specifically involved in the induction of osteoclast differentiation. in 24 lch lesions studied for rankl expression, 17 were found to be positive. the majority of cd1a + lcs expressed rankl. thus, both the cd1a+ lch cells and t cells contribute to osteoclast-togenesis through up-regulated rankl, thus, provide a mechanism for the potentiation of osteoclast formation and bone resorption in lch lesions. in this study, the expression of rank, in the tumor cells of both sites indicate that it play a role in the local bone resorption. similarly, there was a statistically significant relationship between rank and rankl, concerning skull bones alone, which indicated that rank and its ligand had play a role in osteoclastognesis process of lch lesions. egeler et al., (14) showed that the one key feature of osteoclast differentiation is the interaction between rankl and its receptor. the expression of rank by cd1a+ cells as well as the presence of its ligand by activated t cells in lch lesions is also important, as this interaction is known to induce a survival signal to dendritic cells (dcs) (15). senechal et al., (16) found that lcs from lch granulomas expressed rank and rankl (17). the present study improves the way of understanding the mechanism of osteoclast activation in lch of the jaws and skull. in summery, langerhans cell histiocytosis is a locally destructive neoplasm with similar biological behaviour in the jaws and the skull, according to immunohistochemical expression of the studied markers which showed a positive correlation between cd1a and rank in the jaws, rank and rankl in the skull, indicated that rank and rankl contributed to the osteoclastogenesis process of lch in both sites. referances 1. howarth dm, gilchrist gs, mullan bp, wisemanga, edmonson jh, schomberg pj. langerhans cell histiocytosis: diagnosis, natural history, management, and outcome. cancer 1999; 85: 2278–90. 2. flaitz cm. langerhans cell histiocytosis: current insights in a molecular age with emphasis on clinical oral and maxillofacial pathology practice. oral surg oral med oral pathol oral radiol endod 2005; 100:s42–66. 3. lacey dl, timms e, tan hl, kelly mj, dunstan cr, roodman gd. mechanisms of bone metastasis. n engl j med 2004; 350:1655-64. 4. sahaya s, hemalatha r, avaneendra t, et al. immunohistological analysis of cd1a+ langerhans cells and cd57+ natural killer cells in healthy and diseased human gingival tissue: a comparative study. j indian soc periodontol 2009; 13(3): 150-4. 5. da silva, ta, batista ac, mendonc ef, leles cr; fukada s, cunha fq: comparative expression of rank, rankl, and opg in keratocystic odontogenic tumors, ameloblastomas, and dentigerous cysts. oral surg oral med oral pathol oral radiol endod 2008; 105: 333–41. 6. xianbo p, wei g, tingting r, et al: differential expression of the rankl/rank/opg system is associated with bone metastasis in human non-small cell lung cancer plos one 2013; 8(3): e58361. 7. cochrane la, prince m, clarke k. langerhans' cell histiocytosis in the paediatric population: presentation and treatment of head and neck manifestations. j otolaryngol 2003; 32: 33–7. 8. aricò m, clementi r, caselli d, danesino c. histiocyte disorders. hematol j 2003; 4:171-9. 9. nicholas d'ambrosio, soohoo s, warshall c, johnson s. craniofacial and intracranial manifestations of langerhans cell histiocytosis: report of findings in 100 patients. am j roentgenol 2008; 191(2): 589–97. 10. colby tv, lombard c. histiocytosis x in the lung. hum pathol 1983; 14: 847–56. 11. scholz m, firsching r, feiden w, breining h, brechtelsbauer d, harders a: gagel's granuloma (localized langerhans cell histiocytosis) in the pituitary stalk. clin neurol neurosurg 1995; 97(2):164–6. 12. islinger rb, kuklo tr, owens bd, horan pj, choma tj, murphey md, temple ht: langerhans' cell j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 83 histiocytosis in patients older than 21 years. clin orthop relat res 2000; 379: 231–5. 13. bank mi, rengtved p, carstensen h, petersen bl. langerhans cell histiocytosis: an evaluation of histopathological parameters, demonstration of proliferation by ki-67 and mitotic bodies. apmis 2003; 111: 300–8. 14. egeler m, costa c, annels n, hogendoorn p, et al :presence of osteoclast-like multinucleated giant cells in the bone and non-ostotic lesions of langerhans cell histiocytosis. jem 2005; 201(5): 687–93. 15. cremer im, dieu-nosjean s, marechal c, et al. longlived immature dendritic cells mediated by trancerank interaction. blood 2002; 100: 3646–55. 16. senechal b, elain g, jeziorski e, et al. expansion of regulatory t cells in patients with langerhans cell histiocytosis. plos med 2007; 4(8): e253. 17. egeler rm, favara be, van meurs m. differential in situ cytokine profiles of langerhans-like cells and tcells in langerhans cell histiocytosis abundant expression of cytokines relevant to disease and treatment. blood 1999; 94: 4195-201. shukria f.doc j bagh college dentistry vol. 25(4), december 2013 effectiveness of prophylactic oral diagnosis 56 effectiveness of prophylactic agents in prevention of oral mucositis in patients with head and neck cancer receiving radiotherapy shukria m. al-zahawi, b.d.s., m.sc. (1) showan s. marouf, m.b.ch.b., m.sc. (2) hassan a.m. al-barzenji, b.d.s., ph.d. (3) abstract background: oral mucositis is regarded as one of the major complications of radiation therapy especially in patients with head and neck cancer. the aim of this study was to evaluate the efficacy of glutamine in preventing or minimizing the development of mucositis of the oral cavity. subjects and methods: forty-six participants were randomly selected amongst those who were planned to receive radiation therapy for head and neck region cancers. they were randomly divided into two groups of 23 subjects, one group received glutamine and the second group received a placebo. results: glutamine had a statistically significant effect in reducing the occurrence and/or severity of oral mucositis in the treated patients compared to patients in the control group. gender and age had no effect in the development or severity of oral mucositis in the studied patients. conclusions: it can be concluded that glutamine can be used effectively to prevent or minimize oral mucositis amongst cancer patients who receive radiation therapy. key wards: oral mucositis, head and neck cancer, radiation therapy, glutamine. (j bagh coll dentistry 2013; 25(4):5659). introduction oral mucositis refers to lesions that characterize by sore erythematous and ulcerative changes of the mouth which are regarded as common complications in patients undergoing cancer therapy. they are painful and negatively influence the nutrition and quality of life, and sometimes can contribute to local and systemic infections.1 radiation-induced oral mucositis have been observed and studied since a long time.2 it is often the dose limiting factor that interferes greatly with the intensification of anticancer therapy.3,4 patients with head and neck cancer usually receive approximately 200 cgy daily dose of radiation, five days per week, for five to seven continuous weeks.5-8 almost all such patients will develop some degree of oral mucositis within the first three weeks of radiotherapy; it peaks at week five and can persist for weeks following the end of the radiation therapy.9,10 the development of oral mucositis depends on a number of factors such as the type and dose of ionizing radiation, angulation of the radiation beam, location of the tumor, volume of irradiated tissue, dose per fraction, cumulative dose and, also importantly, the degree of oral hygiene.11 pathologically, radiation therapy is an effective activator of several injury-producing pathways such as nuclear factor-κb (nf-κb) and nrf-2 that lead to the upregulation of genes that modulate the damage response. (1)department of oral diagnosis. college of dentistry. hawler university. (3)department of oral diagnosis. college of dentistry. hawler university. macrophages produce pro-inflammatory cytokines that causes further tissue injury.12 in addition, direct and indirect damages to epithelial stem cells result in a loss of renewal capacity. as a result, the epithelium begins to thin and patients start to experience the symptoms of radiationinduced mucositis.13 clinically, mucositis is characterized by painful mouth sores, sloughing of the epithelium, crusting of the lips and ulcerations at various parts of the oral mucosa.14 it often causes severe pain and increases the risk for the development of systemic infection due to bacterial, fungal, or viral infections in the mouth.15 glutamine is a neutral amino acid that acts as a substrate for nucleotide synthesis in most dividing cells.16 it is a major energy source for mucosal epithelial cells and stimulates mucosal growth and repair. a number of studies have shown its effectiveness in the prevention and treatment of oral mucositis due to radiation therapy.17-20 the aim of this study was to evaluate the efficacy of glutamine preventing the development or minimizing the severity of oral mucositis in patients with head and neck cancer receiving radiation therapy. additionally to evaluate whether factors such as gender and age have any impact on the protective effect of glutamine. patients and methods the study aimed at comparing the efficacy of glutamine on preventing or minimizing radiationinduced oral mucositis. it was conducted over a period of six months, from april through to j bagh college dentistry vol. 25(4), december 2013 effectiveness of prophylactic oral diagnosis 57 september 2012. during this period, 60patients were enrolled in the study amongst the patients who were attending the department of radiation therapy at rizgary teaching hospital in erbil city for the purpose of receiving therapeutic radiation for head and neck region cancers. the ages of the patients ranged from 20 to 70 years, who classified to young (aged 45 or younger) and older (aged more than 45 years). the participants were randomly divided into two groups as follows: the first group was the control group who received a placebo (distilled water 50 cc), and the second group was regarded as intervention group who received glutamine (10 grams of glutamine powder, dissolved in water (50 cc), taken three times per day). from the 60 patients, who were enrolled initially in the study, only 46 patients (23 in the control and 23 in the treatment arm) were continued until the end of the study. the treatment protocol was started on the first day of radiation therapyand continued regularly through to the end of the course, during which the subjects were evaluated at intervals of every week starting from the beginning of the radiation therapy course thought to the end of the course. the patients received conventionally fractionated radiotherapy as an average of 2.0 gy/day, 5 days per week to the total dose of 50 gy by 5 weeks (end of the radiation therapy course). the oral examination was performed blindly by two specialist dentists, and the mean of their readings were taken for the final analysis. severity of oral mucositis was assessed using who grading criteria as illustrated in table (1). table 1. criteria for the severity of oral mucositis according to the who grading (mucositis of grades 2-4 was regarded as “moderate to severe”) source grade 0 grade 1 grade 2 grade 3 grade 4 who no changes soreness with erythema erythema, ulcers, can eat solids ulcers, liquid diet only alimentation not possible the data entry and statistical analysis was done using spss version 18. the mean difference, standard errors of mean difference and significance was calculated using independentsamples t-test. a p value of less than 0.05 was regarded as significant. results forty-six patients with various types of headand-neck cancers, who were on some sort of radiation therapy, were continued until the end of the study upon which the final data analysis was performed. table (2) showed that glutamine, which was used as intervention, had a statistically significant effect in reducing the occurrence and/or severity of oral mucositis in the treated patients by week 4 and 5 compared to patients in the control group (who received a placebo). the mean degree of mucositis in the control arm was 1.65, meanwhile, this mean of mucositis decreased significantly in the patients in the intervention are, who received glutamine, to 0.87 with a p value of 0.001. as it is illustrated in figure (1), the protective effect of glutamine started to appear in the very first weeks of commencing the radiation therapy, and became more evident after the 3rd week of treatment by glutamine. table 2. distribution of mean levels of oral mucositis in control group andintervention (glutamine) group, and mean difference between the groups (wk5) treatment no. mean s.e. mean difference s.e. 95% confidence interval of difference p value mucositis control glutamine 23 1.65 0.18 0.78 0.23 0.33 – 1.24 0.001 23 0.87 0.13 j bagh college dentistry vol. 25(4), december 2013 effectiveness of prophylactic oral diagnosis 58 additionally, as it is shown in figure (2), amongst the twenty-three patients in the control group (without intervention), ten (77%) of them developed some degree of moderate to severe mucositis (grades 2-4), while less than a quarter of patients the intervention groups (who received glutamine) developed moderate to severe mucositis. the study also showed that gender had no effect in the development or severity of oral mucositis in the studied patients. as the mean difference of severity of mucositis between males and females in both the control and intervention arms, was very small; although slightly favoring the male gender, but the difference was not statistically significant, as it is illustrated in table (3). table 3. distribution of mean levels of oral mucositis between the male and female patients in both the control and intervention arms treatment no. mean of mucositis s.e. mean difference s.e. 95% confidence interval of difference p value mucositis male female 26 1.12 0.15 0.34 0.26 -0.86 – 0.19 0.21 20 1.45 0.21 additionally, the study showed that age had no effect in the development or severity of oral mucositis in the studied patients. as the mean difference of severity of mucositis, between those who aged equal or less than 45 years compared to those older than 45 years of age in both of the control and intervention arms was small. although the younger patient developed slightly less severe mucositis comparing their older counterparts, but the difference was not statistically significant, as it is illustrated in table (4). table 4. distribution of mean levels of oral mucositis according to age groups treatment number mean s.e. mean difference s.e. 95% confidence interval of difference p value mucositis young older 19 1.05 0.21 0.36 0.26 -0.88 – .017 0.18 27 1.41 0.15 discussion glutamine is a neutral amino acid that acts as a substrate for nucleotide synthesis in most dividing cells. it is a major energy source for mucosal epithelial cells and stimulates mucosal growth and repair.20,21 animal studies have suggested that dietary supplementation with glutamine may protect the gut mucosa from both radiotherapy and chemotherapy side effects,21,22 and some other studies have showed, with limited evidence, that glutamine may decrease the duration of mucositis.18-20 figure 1: mean severity of mucositis amongst patients on glutamine vs. placebo from the start through to the end of radiation therapy course. figure 2: percentage of patients who developed “moderate to severe mucositis amongst the control group vs. the intervention group j bagh college dentistry vol. 25(4), december 2013 effectiveness of prophylactic oral diagnosis 59 many studies have been done in order to define the best clinical protocol for prophylaxis and treatment of radiation-induced mucositis.1,3,4,9,14 in this study we used glutamine powder for preventing and treating oral mucositis in patients with head and neck cancer receiving radiation therapy. concordantly with other studies that have been done before on glutamine, our study results revealed that glutamine was significantly reduced both the occurrence and severity of mucositis amongst the studied twentythree patients with head and neck cancer who received radiation therapy. this protective effect is may be due to the fact that malignancy produces a state of physiologic stress that is characterized by a relative deficiency of glutamine, a condition that is further exacerbated by the effects of cancer treatment (radiation therapy). glutamine deficiency may impact on normal tissue tolerance and repair following antitumor treatment. therefore, providing glutamine during cancer treatment has the potential to abrogate treatment-related toxicity; and its supplementation may enhance the therapeutic index by protecting normal tissues, and sensitizing tumor cells to chemotherapy and radiation-related injury.16-21 additionally, glutamine helps the function immune system which is part of protection against development of cancer and treatment-related complications.23 as a conclusion, glutamine, which is an amino acid that acts as a substrate for nucleotide synthesis in most dividing cells and is a major energy source for mucosal epithelial cells that stimulate mucosal growth and repair, can be used effectively in clinical practice to prevent or to reduce the development of oral mucositis as a side effect of radiation therapy amongst patients with head and neck cancer. references 1. plevovia p. prevention and treatment of chemotherapy and radiotherapy induced oral mucositis: a review. oral oncol 1999; 35: 453–70. 2. berger am, kilroy tj. oral. in: devita vt, hellman s, rosenberg sa (eds). cancer: principles and practice of oncology. 5th ed. philadelphia: jb lippincott; 1997. pp. 2714–25. 3. lalla rv, peterson de. oral mucositis. dent clin north am 2005; 49:167–84. 4. treister n, sonis s. mucositis: biology and management. curr opin otolaryngol head neck surg 2007; 15:123–9. 5. vikram b, strong ew, shah j, spiro rh. elective postoperative irradiation in stages iii and iv epidermoid carcinoma of the head and neck. am j surg 1980; 140: 580. 6. devitajr, lawrence t, resenber s, eds. cancer principles and practice of oncology. 8th ed. philadilphia: lippincott williams & wilkins; 2008. 7. peters lj, goepfert h, ang kk, et al. evaluation of the dose for postoperative radiation therapy of head and neck cancer: first report of a prospective randomized trial. int j radiat oncol biol phys 1993; 26; 3-11. 8. thames hd jr, withers hr, peters lj, fletcher gh. changes in early and late radiation responses with altered dose fractionation: implications for dosesurvival relationships. int j radiat oncol biol phys 1982; 8: 219-26. 9. resenthal di, trotti a. strategies for managing radition-induced mucositis in head and neck cancer. semin radiat oncol 2009; 19: 29-34. 10. ballantyne jc, fishman sm, rathmell jp. bonica's management of pain. 4th ed. lippincott williams & wilkins; 2009. pp. 621-9. 11. andrews n, griffiths c. dental complications of head and neck radiotherapy: part 1. aust dent j 2001; 46(2): 88-94. 12. logan rm, gibson rj, sonis st, keefe dm. nuclear factor-κappa b (nf-kappab) and cyclooxygenase-2 (cox-2) expression in the oral mucosa following cancer chemotherapy. oral oncol 2007; 43: 395–401. 13. gibson rj, bowen jm, cummins ag, logan r, healey t, keefe dm. ultrastructural changes occur early within the oral mucosa following cancer chemotherapy [abstract a-373] support care cancer 2004; 12: 389. 14. silverman s, jr. diagnosis and management of oral mucositis. j supp oncol 2007; 5: 13-21. 15. ankaya h, güneri p. importance of a dental approach in head and neck cancer therapy. apjoh 2005; 1 (4): 114-9. 16. wasa m, bode bp, abcouwer sf, collins cl, tanabe kk, souba ww. glutamine as a regulator of dna and protein biosynthesis in human solid tumor cell lines.ann surg 1996; 224(2):189-97. 17. savarese dm, savy g, vahdat l, wischmeyer pe, corey b. prevention of chemotherapy and radiation toxicity with glutamine. cancer treat rev 2003; 29(6): 501-13. 18. wolfgang kostler, michael hejna, catherina, wenzel, christopher, zeilinski. oral mucositis complicating chemotherapy /radiotherapy: options for prevention and treatment. ca cancer j clin 2001; 51: 290-315. 19. eilers j. nursing interventions and supportive care for the prevention and treatment of oral mucositis associated with cancer treatment. oncology nursing forum 2004; 31(4): 13-21 20. huang ey, leung sw, wang cj, et al. oral glutamine to alleviate radiation induced mucositis. a pilot randomized trial. int j radat oncol biol phys 2000; 46: 535-9. 21. skubitz km, anderson pm. oral glutamine to prevent chemotherapy induced stomatitis: a pilot study. j lab clin med 1996; 127(2): 223-8. 22. carneiro-filho ba, oria rb, wood rea k, brito ga, fujii j, obrig t, lima aa, guerrant rl. alanylglutamine hastens morphologic recovery from 5fluorouracil-induced mucositis in mice. nutrition 2004; 20(10): 934-41. 23. abcouwer sf. the effects of glutamine on immune cells [editorial]. nutrition 2000; 16(1): 67-9. ban.doc j bagh college dentistry vol. 27(1), march 2015 salivary antioxidants pedodontics, orthodontics and preventive dentistry 159 salivary antioxidants in relation to dental caries among a group of lead-acid batteries factory workers ban t. al-souz, b.d.s. (1) wesal a. al-obaidi, b.d.s. m.sc. (2) abstract background: lead-acid battery workers are at higher risk for systemic diseases as well as oral diseases like dental caries. the aim of this study was to assess selected salivary antioxidants and their relation with dental caries among lead acid battery factory workers in comparison with non-exposed group. materials and methods: the sample consisted of 35 subjects aged 35-45 year-old who worked in babylon lead acid battery factory in baghdad city and matching group that not exposed to lead were selected as a control. dental caries severity was recorded by using dmfs index, stimulated salivary samples were collected and analyzed for the measurement of salivary antioxidants (uric acid, total protein, catalase and glutathione peroxidase enzymes). results: the antioxidants levels (uric acid, catalase and glutathione peroxidase enzymes) were higher among the study group than the control group with non-significant difference for uric acid, highly significant difference for catalaseenzyme and significant for glutathione peroxidaseenzymes, whereas total protein level was significantly lower among the study group than the control. regarding dental cariesseverity, dmfs values were significantly higher among study group compared to that among control group. all the correlations between salivary antioxidants and dental carries found to be weak non-significant for both groups. conclusions: selected salivary antioxidants were found to have little effects dental caries of the study group, although dental caries revealed higher percentage of occurrence among lead exposed workers. therefore, special oral health preventive and educational programs are needed for them. key words: lead exposure, lead acid battery workers, antioxidants, oral health status. (j bagh coll dentistry 2015; 27(1):159-163). introduction air-pollution is a major public health problem affecting everyone in developed and developing countries alike (1), it can be define as an introduction of physico-chemical or biological materials into the earth's atmosphere that may cause harm or discomfort to humans or other living organism or deterioration of natural environment (2). one of the most familiar of the particulates in air pollutants is lead (3). the manufacturing of lead acid batteries can result in lead exposures sufficient to cause chronic and acute health effects (4,5), it effects almost all the body systemsespecially red blood cells, liver, nervous system, gonads andkidneys (1). air pollutants give rise to oxidative stress and reactive oxygen species production occurs in the mitochondria, cell membranes, phagosomes, and the endoplasmic reticulum(6). dental caries is the localized destruction of susceptible dental hard tissues by acids produced by bacterial fermentation of dietary carbohydrates (7). it is a multifactorial disease involving the presence of microorganisms, the host, the substrate and alteration of the immunological system (8).studies found an increased in the caries prevalence among lead exposed people (9, 10). (1)m.sc. student, department of pedodontics and preventive dentistry, dental college, university of baghdad. (2)professor, department of pedodontics and preventive dentistry, dental college, university of baghdad. saliva was found to affect oral health through various defense mechanisms such assalivary flow rate, buffer capacity,electrolytes, total protein, antimicrobial activities etc(11), in addition to its antioxidant system (12). the specific role of antioxidants is to neutralize rampaging free radical and thus reducing its capacity to damage (13). materials and methods the sample consisted of 35 subjects aged 3545 year-old at babylon lead acid battery factory in baghdad city. they should be non-smoker, with no medical history, shouldn't take any medications, and shouldn't wear any fixed or removable dental prostheses. the collection of stimulated salivary samples was performed according to the instructions cited by tenovuo and lagerlöf (14).then salivary samples were taken to the laboratory for biochemical analysis at the poisoning consultation center/ medical city. salivary antioxidants were determined colorimetrically by using the spectrophotometer for uric acid (ua) a ready kit was used (human, germany). this method enables to determination of uric acid by reaction with uricase. the formed h2o2 reacts under catalysis of peroxidase with 3.5-dichloro-2-hydroxybenzenesulfonic acid (dchbs) and 4-aminophenazone (pap) to give a red-violet quinoneimine dye as indicator. for total protein (tp) (sybrio frace) kit was used, proteins modify spectrum j bagh college dentistry vol. 27(1), march 2015 salivary antioxidants pedodontics, orthodontics and preventive dentistry 160 of absorption of the complex pyrogallol red molybdate. globins together with albumin react. the optical density read at 598nm is proportional to concentration in proteins. determination of catalase enzyme (cat) according to beers and sizer (15) modified by aebi (16) using phosphate buffer (50 mm) andhydrogen peroxide (30 mm). whileglutathione peroxidase enzyme (gpx) according to flohe and gunzler (17) using phosphate buffer (0.1 m), glutathione reduced (2 mm), sodium azide (10 mm), hydrogen peroxide (1 mm), trichloroacetic acid (tca) 5 %, dtnb (0.4 mg/ml). dental caries severity was recorded by using dmfs index by who (18). results sample distribution according to age is shown intable-1.the means and standard deviations of dmfs in study and control groups are demonstrated in table-2 which revealed that dmfs, ds, ms, fswere higher among study group with statistically highly significant difference for dmfs, ds and no significant for ms, fs components. table-3 demonstrates comparison of salivary antioxidant concentration between the study and control groups, all the selected antioxidant except the total protein showed higher mean values among study groupwith non-significant difference for ua, significant for gpx and highly significant difference concerning cat enzyme, while tp was significantly lower amongstudy group than the control group. pearson’s correlation coefficient between caries experience and salivary elements concentrations are clarified in table-4, all salivary antioxidants showed weak and statistically not significant correlations with caries experience, in positive direction concerning ua with ms, also tp with ds, ms, fs, dmfs and cat enzyme with fs for the study group, while the positive relation in control group was recorded between tp with ds and cat enzyme with fs, concerning gpx enzyme positive relation was found with all dmfs components, where all the other relations was negative. table 1: distribution of subjects' sample by age groups age group (years) no. % study 35-40 22 62.86 41-45 13 37.14 total 35 100 control 35-40 22 62.86 41-45 13 37.14 total 35 100 tables 2: caries experience among study and control groups variables age group (years) study group control group statistic test mean ± sd mean ± sd t-test p-value df ds 35-40 10.41 6.53 3.23 3.07 4.67 0.00** 42 41-45 12.00 7.34 6.15 6.37 2.16 0.04* 24 total 11.00 6.78 4.31 4.71 4.79 0.00** 68 ms 35-40 12.68 9.87 8.82 8.95 1.36 0.18 42 41-45 13.31 9.21 8.00 9.68 1.43 0.17 24 total 12.91 9.5 8.51 9.01 1.98 0.05 68 fs 35-40 2.41 2.80 2.73 4.07 -0.30 0.76 42 41-45 4.77 8.74 2.69 5.69 0.71 0.48 24 total 3.29 5.76 2.71 4.65 0.45 0.65 68 dmfs 35-40 25.50 12.14 15.00 11.05 2.98 0.005** 42 41-45 29.31 16.01 15.31 11.98 2.52 0.02* 24 total 26.91 13.64 15.11 11.33 3.94 0.00** 68 *significant (p<0.05), **highly significant (<0.01). j bagh college dentistry vol. 27(1), march 2015 salivary antioxidants pedodontics, orthodontics and preventive dentistry 161 table 3: salivary antioxidants among study and control groups variables age group (years) study group control group statistic test mean ± sd mean ± sd t-test p-value df ua (mg/dl) 35-40 2.59 0.88 2.58 0.96 0.06 0.95 42 41-45 2.81 0.88 2.48 0.89 0.95 0.35 24 total 2.67 0.87 2.54 0.92 0.61 0.54 68 tp (mg/dl) 35-40 59.62 12.18 65.17 15.20 -1.33 0.19 42 41-45 58.66 11.29 69.88 8.22 -2.89 0.01* 24 total 59.26 11.70 66.92 13.11 -2.57 0.01* 68 cat (u/ml) 35-40 21.30 0.69 19.98 0.98 5.13 0.00** 42 41-45 21.79 0.45 19.70 1.22 5.76 0.00** 24 total 21.48 0.65 19.87 1.07 7.56 0.00** 68 gpx (u/ml) 35-40 0.30 0.19 0.21 0.15 1.76 0.09 42 41-45 0.28 0.17 0.22 0.08 1.06 0.30 24 total 0.29 0.18 0.21 0.13 2.07 0.04* 68 *significant (p<0.05), **highly significant (p<0.01). table 4: salivary antioxidant in relation tocaries experience among study and control groups variables study group control group ds ms fs dmfs ds ms fs dmfs ua r -0.12 0.02 -0.08 -0.06 -0.18 -0.04 -0.29 -0.18 p 0.48 0.91 0.64 0.72 0.29 0.84 0.09 0.29 tp r 0.04 0.04 -0.07 0.02 0.05 -0.02 -0.06 -0.06 p 0.80 0.79 0.68 0.89 0.76 0.88 0.73 0.72 cat r -0.07 0.01 0.05 0.01 -0.05 -0.21 0.10 -0.18 p 0.68 0.95 0.76 0.97 0.77 0.23 0.57 0.28 gpx r -0.05 0.01 -0.11 -0.06 0.14 0.14 0.10 0.21 p 0.76 0.94 0.53 0.74 0.41 0.43 0.56 0.22 discussion lead is a ubiquitous environmental toxin that induces abroad range of physiological, biochemical, and behavioraldysfunctions (19). results of the current study revealed thatuawas slightly higher among study group than the control group, the same result was also reported by other studies (20-22), this elevation in ua level may be due to adverse effects of lead on renal function that may cause hyperuricemia (22) or may be explained as a defense mechanism against pollutants, since ua is a dominant antioxidant in the body (23), while tp was significantly lower in the study group than the control group, the decrease in tp level may be due to proteinuria that occur as a result of kidney impairment in lead toxicityand may be a cause of protein loss (24),or could be attributed to lower intake of protein-rich due to low socio-economic level and lacking knowledge about the importance of healthy diet (25), same result was reported by other studies (26, 27). also the results revealed signifigantly higher levels of both cat and gpx enzymes were found among the study group than the control group, this may be explained as a defense mechanism against oxidative stress as results of pollution (28). also data showed that dental caries (dmfs, ds, ms, fs) were significantly higher among study group than the control group, this may be due to poor oral hygiene among the study or may be attributed to the lead exposure effect, as lead ions considered as a cariogenic element (29,30). also the result of this study revealed a weak negative nonsignificant correlation between dental caries and salivary antioxidants (ua, cat, gpx enzyme) among study group, this confirmed the protective role of salivary antioxidants and this effect is nonsignificant or limited in this study may be due to the fact that dental caries is a multi-factorial disease (31). the present research also give a positive relations of dmfs index and ds fraction with the total protein although statistically were not significant, this may be due to the fact that total salivary proteins may have both protective and detrimental properties. some proteins such as antimicrobial and ph modulating proteins play a protective role in the oral cavity, while adhesins and agglutinins play a detrimental role by increasing the colonization of microorganisms (32).from the present study, workers exposed to lead showed an elevated risk of achieving caries, missed teeth due to caries and high dmft index, thus it is recommended that this group should j bagh college dentistry vol. 27(1), march 2015 salivary antioxidants pedodontics, orthodontics and preventive dentistry 162 receive a special preventive program and specialized care centers should be offered. references 1. who. air quality and health number 313, world health organization, genava, switzerland, 2011. 2. gurjar b, molina l, ojna c. air pollution, health and environmental impact. usa: crc press; 2010. 3. hodgson e. a textbook of modern toxicology. 4th ed. canada: john wiley and sons; 2011. 4. gottesfeld p, pokhre a. review: lead exposure in battery manufacturing and recycling in developing countries 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na.chronic occupational exposure to lead and its impact on oral health.j egypt public health assoc 2008; 83: 56. 11. pedersen am. saliva. 1st ed. blumøller healthcar: university of copenhagen; 2007. 12. battino m, ferreiro ms, gallardo i, newman hn, bullon p. the antioxidant capacity of saliva. j clin periodontol 2002; 29: 189-94. 13. sapakal vd, shikalgar ts, ghadge rv, adnaik rs, naikwade ns, magdum cs. in vivo screening of antioxidant profile: a review. j herb med toxicol 2008; 2: 1-8. 14. tenovuo j, lagerlöf f. saliva. in: thylstrup a, fejerskov o (eds.). textbook of clinical cariology. 2nded. copenhagen: munksgaard; 1994. p. 17-43. 15. beers r, sizer i. a spectrophotometric method formeasuring the breakdown of hydrogen peroxide by catalase. j biol chem 1952; 195: 133-40. 16. flohé l. günzler wa. assay of glutathione peroxidase. methods enzymol 1984; 105: 115-21. 17. aebi h. catalase in vitro. methods enzymol 1984; 105: 121-6. 18. who. basic methods of oral health survey 3rd ed. world health organization, geneva, switzerland, 1987. 19. ic consultants ltd. lead: the facts. london: ic consultants lt; 2001. 20. weaver vm, jaar bg, schwartz bs. associations among lead dose biomarkers, uric acid, and renal function in korean lead workers. environ health perspect 2005; 113(1): 36-42. 21. ahmed k, ayana g, engidaworkc e. lead exposure study among workers in lead acid battery repair units of transport service enterprises, addis ababa, ethiopia: a cross-sectional study. j occup med toxicol 2008; 3: 30. 22. alasia dd, emem-chioma pc, wokoma fs. association of lead exposure, serum uric acid and parameters of renal function in nigerian lead exposed workers. ijoem 2010; 1(4); 182-90. 23. glantzounis gk, tsimoyiannis ec, kappasam, galaris da. uric acid and oxidative stress. curr pharm des 2005; 11(32): 4145-51. 24. gonick h. nephrotoxicity of cadmium and lead. indian j med res 2008; 128(4): 335-52. 25. woolley p. syncrisis: the dynamics of health: an analytic series on the interactions of health and socioeconomic development, issues 7-11. u.s. office of international health, division of planning and evaluation, 2008 26. pachathundikandi s, varghese e. blood zinc protoporphyrin, serum total protein, and total cholesterol levels in automobile workshop workers in relation to lead toxicity: our experience. indian journal of clinical biochemistry 2006; 21 (2): 114-7. 27. kasperczyk s, slowinska-lozynska l, kasperczyk a, wielkoszynski t, birkner e. the effect of occupational lead exposure on lipid peroxidation, protein carbonylation, and plasma viscosity. toxicol ind health 2013. 28. kelly f. oxidative stress: its role in air pollution and adverse health effects. occup environ med 2003; 60: 612-6. 29. zahir s, sarkar s. study of trace elements in mixed saliva of caries free and caries active children. j indian soc pedod prev dent 2006; 24(1): 27-9. 30. pradeep kk, hegde a m. lead exposure and its relation to dental caries in children. j clin pediatr dent 2013; 38(1): 71-4. 31. marya cm. a textbook of public health dentistry. 1st ed. new delhi: jaypee brothers; 2011. 32. deshpande rr, panvalkar ps, kulkarni aa, gadkri tv. age-related changes of the human salivary secretory total protein complex and trace elements in children between the age group of 3-16 years. j biomed sci res 2011; 3: 362-7. j bagh college dentistry vol. 27(1), march 2015 salivary antioxidants pedodontics, orthodontics and preventive dentistry 163 الخالصة الھدف من ھذه الدراسة ھو لتقییم مستوى . یتعرض العاملون في معامل البطاریات إلى مشاكل في الصحة العامة باالضافة الى صحة الفم واالسنان من ضمنھا تسوس االسنان المقدمة .اللعابیة ومدى تأثیرھا على تسوس األسنان لعینة من العاملین في معمل بطاریات بابل ومن ثم مقارنتھا مع عینة ضابطةمضادات األكسدة س والعمر شخصا مطابقین بالجن) 35(وكذلك 45-35عامل في معمل بطاریات بابل في مدینة بغداد واللذین تتراوح أعمارھم بین ) 35(تكونت مجموعة الدراسة من المواد والطرق تم حساب شدة التسوس من خالل تطبیق مؤشر دالة تسوس سطح االسنان لمنظمة الصحة العالمیة وبعدھا تم تحلیل . وغیر معرضین لمادة الرصاص تم اختیارھم كمجموعة ضابطة ).ي الكاتالیز و الكلوتاثیون بیروكسیدایزأنزیم, یكرویحامض ال, البروتین الكلي (عینات اللعاب كیمیائیا لغرض إیجاد مستوي تركیز مضادات األكسدة اعلى في مجموعة الدراسة مقارنة بالمجموعة الضابطة مع وجود فرق ) أنزیمي الكاتالیز و الكلوتاثیون بیروكسیدایز, حامض الفولیك(األكسدة وجد إن مستوى تركیز مضادات النتائج لي اقل في مجموعة الدراسة مقارنة بینما كان مستوى البروتین الك, معنوي بالنسبة ألنزیم الكاتالیز و الكلوتاثیون بیروكسیدایز وعدم وجود فرق معنوي بالنسبة لحامض الفولیك أظھرت . كذلك وجد ان دالة تسوس سطح األسنان اعلى لدى مجموعة الدراسة مقارنة بالمجموعة الضابطة مع وجود فرق معنوي عالي. بالمجموعة الضابطة مع وجود فرق معنوي جابي بالنسبة للبروتین الكلي و أنزیم الكاتالیز لمجموعة الدراسة و أنزیم الكلوتاثیون بیروكسیدایز مضادات األكسدة ارتباطا ضعیف غیر معنوي مع دالة تسوس األسنان باالتجاه اإلی .للمجموعة الضابطة وبقیة العالقات باالتجاه السالب لدى مجموعة الدراسة ولھذا یتطلب األمر برامج وقائیة وجد إن مضادات األكسدة اللعابیة المختارة لھا تأثیر ضعیف على تسوس االسنان الذي اظھر نسبة حدوث وشدة عالیة االستنتاج .و تثقیفیة خاصة بصحة الفم و األسنان لعمال معمل البطاریات .التعرض لمادة الرصاص ، عمال معمل البطاریات الحامضیة، مضادات االكسدة، صحة الفم واالسنانكلمات مفتاحیة faris.doc j bagh college dentistry vol. 27(2), june 2015 salivary iga in oral diagnosis 54 salivary iga in chronic kidney disease patients undergoing hemodialysis in missan governorate faris abid hatem, b.d.s., h.d.d. (1) zaheda jassim mohammad, b.d.s, m.sc., ph.d. (2) abstract background: chronic kidney disease is a worldwide health problem, with adverse outcomes of cardiovascular disease and premature death, can be divided into five stages, depending on how severe the damage is to the kidneys, or the level of decrease in kidney function, the final stage of chronic kidney disease is called end-stage renal disease, salivary immunoglobulin a is the main immunoglobulin found in mucous secretions, including tears, saliva, colostrum and secretions from the genitourinary tract gastrointestinal tract, prostate and respiratory epithelium. it is also found in small amounts in blood.this study aimedto measuresalivary flow rate and salivaryimmunoglobulin alevels in chronic kidney disease patients on hemodialysis treatment in comparison with healthy control subjects. materials and methods: ninety (90) subjects were participated in this study; 45 patients undergoing hemodialysis with chronic kidney diseases; 45 health control subjects. saliva collected was measured and levels of salivary immunoglobulin a were measured by enzyme link immunosorbent assay (elisa). results:the present studyrevealed that the mean value of salivary flow rate in chronic kidney disease patients was (0.34 ± 0.19) ml/min, while for healthy control subjects was (1.02 ± 0.39) ml/min, there wasstatisticallysignificantly decrease in salivary flow rate ofchronic kidney disease on hemodialysis patients as compared to control healthy subjects.the present study revealed that the (mean±sd) of the immunoglobulin a in chronic kidney disease patients on hemodialysis (388.81±227.86) µg./ml, while in control group (273.98±155.89) µg./ml, the result revealed statistically significant increase in chronic kidney disease patients on hemodialysis as compared to control subjects. conclusions: salivary immunoglobulin (iga) reflects the functional capacity of the glands. increased concentration of this component is usually marker of a poor general condition. key words: chronic kidney disease; hemodialysis; salivary flow rate and salivary immunoglobulin a. (j bagh coll dentistry 2015; 27(2):54-57). introduction chronic kidney disease (ckd) is a worldwide health problem, with adverse outcomes of cardiovascular disease and premature death (1).ckd can be divided into five stages, depending on how severe the damage is to the kidneys, or the level of decrease in kidney function, the final stage of chronic kidney disease is called end-stage renal disease (esrd). at this stage, the kidneys are no longer able to remove enough wastes and excess fluids from the body. at this point, the patient would need dialysis or a kidney transplant (25). in end stage renal disease (esrd) patients, the oral health could also negatively be affected by the underlying pathology, the dialysis treatment, oral dryness or an altered salivary composition (6-8). renal failure is associated with vomiting, oral malodor and xerostomia which could all affect the oral health of these patients (9, 10). immunoglobulin a (iga, also referred to as siga) is an antibody that plays a critical role in mucosal immunity. more iga is produced in mucosal linings than all other types of antibody combined (11), between three and five grams are secreted into the intestinal lumen each day (12). (1)master student, department of oral diagnosis. college of dentistry, university of baghdad. (2)assistant professor, department of oral diagnosis. college of dentistry, university of baghdad. iga is the main immunoglobulin found in mucous secretions, including tears, saliva, colostrum and secretions from the genitourinary tract, gastrointestinal tract, prostate and respiratory epithelium. it is also found in smallamounts in blood. the secretory component of siga protects the immunoglobulin from being degraded by proteolytic enzymes, thus siga can survive in the harsh gastrointestinal tract environment and provide protection against microbes that multiply in body secretions (13), siga can also inhibit inflammatory effects of other immunoglobulin (14). the high prevalence of iga in mucosal areas is a result of cooperation between plasma cells that produce polymeric iga (piga), and mucosal epithelial cells that express an immunoglobulin receptor called the polymeric ig receptor (pigr). piga is released from the nearby activated plasma cells and binds to pigr. this results in transportation of iga across mucosal epithelial cells and its cleavage from pigr for release into external secretions (15). secretory immunoglobulin a (siga) is the most frequently found immunoglobulin in mixed saliva and is considered to be a secretory factor for acquired immunity in the oral cavity. antibodies of this type participate in the preservation of the integrity of the oral surfaces (enamel and mucous membrane) and, through j bagh college dentistry vol. 27(2), june 2015 salivary iga in oral diagnosis 55 restriction of microbial adhesion, become part of the first line of defense. siga antibodies independently, or in complexes, participate in antigen-antibody reactions on the mucous membrane (and partly on the enamel too), thus limiting the penetration of bacteria and toxins (1618). it is clear that siga plays an important role in oral homeostasis and is an important indicator of the defensive status of the oral cavity, where the rich oral microbiota has antigenic potential and can stimulate secretory antibodies (19). materials and methods ninety (90) subjects were participated in this study, they were divided into two groups: patients group comprised of 45 subjects undergoing hemodialysis with chronic kidney diseases; control group comprised of 45 subjects with no history of any systemic diseases. the patients were excluded: smoking; pregnancy; hepatitis; malignancy. salivary samples were collected from the study group and the control group, were collected between 8:00 am and 11:00 am to minimize effects of the diurnal variability in salivary composition. samples were collected before meals or at least 2 h after meals. after giving instruction to wash the oral cavity with distal water to remove any debris, unstimulated whole saliva was collected by spitting method, to avoid influence of stress on the secretion rate, all patients were told to rest for 10 minutes before the registration of the salivary flow rate. during the period of collection the individuals were comfortably seated in a ventilated and lighted room. the saliva was collected for exactly (5minutes). all subjects were asked to achieve a passive flow of saliva without masticatory movements for 5 minutes, timed with a stop watch. then the volume of each saliva sample was measured and the flow rate ml/5min. was calculated, salivary flow rate= volume of saliva per ml/time per minute. then sample were put in small cooling box after collection to stop the growth of bacteria, the samples centrifuged at 4000 rpm for 15 minutes. the supernatant aspirated and stored together in deep freezer at -20 c until the other parameters were analyzed. saliva collected was measured and level of siga was measured by enzyme immunosorbent assay (elisa). results table (1) and figure (1) revealed that the mean value of salivary flow rate in ckd patients was (0.34 ± 0.19) ml/min, while for healthy control subjects was (1.02 ± 0.39) ml/min, the salivary flow rate in ckd on hd patients was significantly decrease than in the control healthy subjects. the present study revealed that the (mean±sd) of the siga in ckd patients on hd (388.81±227.86) µg./ml, while in control group (273.98±155.89) µg./ml, this result revealed statistically significant increase in ckd patients on hd as compared to control subjects as shown in table (2) and figure (2). table 1: mean ±sd of salivary flow with t-test between ckd patients on hd & control group parameter no. mean ±sd se range t-test p-value salivary flow rate patients 45 0.34 ± 0.19 0.03 0.1 0.8 10.24 0.01 (s) control 45 1.02 ± 0.39 0.06 0.5 2.2 s: significant at p<0.05 figure1: mean of salivary flow rate in ckd patients on hd and healthy control group. table 2: mean ±sd of salivary iga with t-test in ckd patients on hd & control subjects. j bagh college dentistry vol. 27(2), june 2015 salivary iga in oral diagnosis 56 n mean ±sd se range t-test p value s iga patients 45 388.81 ± 227.86 33.9 113.92 1063.32 2.79 0.05 (s) control 45 273.98 ± 155.89 23.2 125.43 638.81 (s): significant at p<0.05 figure 2: mean of salivary iga levels in patients & control groups. discussion the lower flow rates of both unstimulated and stimulated whole saliva can be attributed to direct uremic involvement of the salivary glands leading to decreased parenchymatous and excretory functions, and as a result of dehydration due to restriction in fluid intake. acute stress levels in these patients may also possibly reduce the salivary flow rate (20, 21). in the present study, unstimulated whole sfr values in the hd (0.34 ± 0.19) group were significantly lower than those in health control (1.02 ± 0.39), this finding in agreement with previous reports (22-27). only a few studies exist in which saliva of hd patients had been investigated, salivary immunoglobulin may be used as a marker of general oral inflammatory state. salivary iga is considered to belong to the first line of defense of the host against pathogensin saliva via binding to soluble and particulate antigens as well as it inhibits various enzymes and bacterial colonization on oral hard surfaces (28). the logistic regression analysis identified the patient age, the number of concomitant diseases and the low salivary flow rate values as explaining variables for the highest tertiles of salivary protein concentrations (29). salivaryimmunoglobulin (iga) reflects the functional capacity of the glands. increased concentration of this component is usually marker of a poor general condition (30-34). in present study increase salivary iga level as compared to apparently health control showed significantly differences, no previous study could be traced in iraq to compare the present result with. in a study carried out by bots et al in netherland, this study showed that hd has significant acute effects on both salivary secretion rate and protein concentrations in saliva. the total protein concentration decreased significantly comparing before and after dialysis (35). level of siga does not influence the total protein concentration in saliva, suggesting that the salivary glands maintain a normal function and no basement membrane defect seems to be present in hd patients (36). another a study carried out by vesterinen in finland, for oral health was assessed from the predialysis stage through to dialysis and post transplantation stage, the siga concentrations were highest in the dialysis stage, the urea concentration of saliva was high in all stages after kidney transplantation a decrease in siga concentration, was logical and probably due to the immunosuppressant medications taken and to decrease in plasma urea (37). references 1. levey as, de jong pe, coresh j, nahas me, astor bc, matsushita k, gansevoort rt, kasiske bl, eckardt ku. the definition, classification and prognosis of chronic kidney disease: a kdigo controversies conference report. kidney int 2011; 80:17-28. 2. abboud h, henrich wl. clinical practice. stage iv chronic kidney disease. n 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(eds.). brenner and rector's the kidney. 9th ed. philadelphia, pa: saunders elsevier; 2011. j bagh college dentistry vol. 27(2), june 2015 salivary iga in oral diagnosis 57 5. upadhyay a, earley a, haynes sm, uhlig k. systematic review: blood pressure target in chronic kidney disease and proteinuria as an effect modifier. ann intern med 2011; 154: 541-8. 6. kho hs, lee sw, chung sc, kim yk. oral manifestations and salivary flow rate, ph, and buffer capacity in patients with end-stage renal disease undergoing hemodialysis. oral surg oral med oral pathol oral radiol endod 1999; 88: 316–9. 7. klassen jt, krasko bm. the dental health status of dialysis patients. j can dent assoc 2002; 68: 34–8. 8. bayraktar g, kazancioglu r, bozfakioglu s, yildiz a, ark e. evaluation of salivary parameters and dental status in adult hemodialysis patients. clin nephrol 2004; 62: 380-3 9. nagler rm. saliva analysis for monitoring dialysis and renal function. clin chem 2008; 54(9):1415– 1417. 10. virga g, mastrosimone s, amici g et al. symptoms in hemodialysis patients and their relationship with biochemical and demographic parameters. int j artif organs 1998; 21: 788-793. 11. fagarasan s, honjo t. intestinal iga synthesis: regulation of front-line body defenses. nature reviews immunology 2003; 3(1): 63–72. 12. brandtzaeg p, pabst r. let's go mucosal: communication on slippery ground. trends immunology 2004; 25 (11): 570–577 . 13. mescher al. junqueira's basic histology text and atlas. 13th ed. china: mcgraw-hill; 2003. 14. holmgren j, czerkinsky c. mucosal immunity and vaccines. nature medicine 2005; 11: s45 s53. 15. snoeck v, peters i, cox e. the iga system: a comparison of structure and function in different species. vet res 2006; 37 (3): 455–67. 16. bokor-bratic m. clinical significance of analysis of immunoglobulin a levels in saliva. medicinskipregled 2000; 53: 164-8. 17. dodds mw, jonson da, yeh ck. health benefits of saliva: a review. j dentistry 2005; 33(3): 223-33. 18. gonçalves ts, morganti ma, campos lc, rizzatto sm, menezes lm. allergy to auto-polymerized acrylic resin in an orthodontic patient. am j orthod dentofac orthop 2006; 129(3): 431-5. 19. bernimoulin jp. recent concepts in plaque formation. j clin periodontol 2003; 30(suppl 5): 7-90 20. gavalda c, bagan j, scully c, et al. renal hemodialysis patients: oral, salivary, dental and periodontal findings in 105 adult cases. oral dis 1999; 5: 299-302. 21. kho hs, lee sw, chung sc, kim yk. oral manifestations and salivary flow rate, ph, and buffer capacity in patients with end-stage renal disease undergoing hemodialysis. oral surg oral med oral pathol oral radiol endod 1999; 88:316–9 . 22. abdul-razak e. dental, periodontal and salivary changes in patients with chronic renal failure. a master thesis in oral medicine, college of dentistry, university of baghdad, 1994. 23. postorino m, catalano c, martorano c, et al. salivary and lacrimal secretion is reduced in patients with esrd. am j kidney dis 2003; 42: 722-728. 24. bayraktar g, kazancioglu r, bozfakioglu s, yildiz a, ark e. evaluation of salivary parameters and dental status in adult hemodialysis patients. clin nephrol 2004; 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62:71-109. 31. seemann r, hagewald sj, sztankay v, drews j, bizhang m, kage a. levels of parotid and submandibular/sublingualsalivary immunoglobulin an in response to experimental gingivitis in humans. clin oral inves 2004; 8:223-237. 32. teeuw w, bosch ja, veerman ec, amerongen av. neuroendocrine regulation of salivary iga synthesis and secretion. implications for oral health. biol chem 2004; 385:1137-46. 33. pink r, simek j, vondrakova j, faber e, michl p, pazdera j, indrak k. saliva as a diagnostic medium. biomed pap med fac univ palacky olomouc czech repub 2009; 153:103-10. 34. hopcraft ms, tan c. xerostomia: an update for clinicians. aust dent j 2010; 55: 238-44. 35. bots cp, poorterman jh, brand hs, et al. the oral health status of dentate patients with chronic renal failure undergoing dialysis therapy. oral dis 2006; 12(2):176–80. 36. epstein sr, mandel i, scopp iw. salivary composition and calculus formation in patients undergoing hemodialysis. j periodontol 1980; 51:3368. 37. vesterinen m, ruokonen h, furuholm j, honkanen e, meurman jh. oral health in predialysis patients with emphasis on diabetic nephropathy. clin oral investig 2011; 15: 99-104. reem f.doc j bagh college dentistry vol. 25(2), june 2013 surface area measurements restorative dentistry 36 surface area measurements of upper dental cast with different final impressions reem abdul rahim, b.d.s., m.sc. (1) abstract background : surface area anatomy is a proportional point to the retention of complete denture, in past there was no quantitative method to evaluate the surface area, nowadays the size and shape of maxillary arch is measured by different electronically and mathematical devices. a study was therefore, undertaken to measure surface area of upper dental cast that was taken by different final impressions. materials and methods: twenty patients were examined. all of them had a healthy palate with no singe of injury, trauma, or deformity. casts were taken by three different final impressions; zinc oxide, additional silicon, and poly ether. and two different devices were used; the computerized one and the aluminum foil measure. age, sex, and shape of upper dental arch were also evaluated. results: the results of this study showed that the use of different methods to measure the surface area of upper dental cast had a significant difference between the two different measurements, while there was no difference in the measurements between the different final materials. age variable showed more significant difference between the first and second method than sex variable. conclusion: data collected in the present investigation showed a highly significant difference in measurements between the computerized method and the direct foil method. zinc oxide, silicon and poly ether materials showed no significant differences in readings. keywords: surface area, final impression, digitalized measure of dental cast. (j bagh coll dentistry 2013; 25(2):36-40). introduction assessment of surface area is an important factor in dental prosthesis; it has been proved that the retention of complete denture is proportional to its anatomic surface area (1-3). the size of the arches is being important from the standpoints of denture retention; larger area of hard palate is greater for developing good retention of upper denture (4). also the form of the dental supporting tissues become more important in denture retention , with tapering arch is considerably less than with other forms; square , and ovoid forms (1,5). with all these facts dental cast analysis is a threedimensional assessment of the maxillary and mandibular dental arches, and this is one of the basic tools of diagnosis and treatment planning in prosthesis (6, 7). so many measurements techniques have been used to obtain data of palatal tissue bearing area; some researchers used the direct standardized land marks that used as end points of the measurements on the cast, but this method was unfortunately timeconsuming, and no derived future data could be obtained (8,9). others used the indirect analyzing data of two dimensional photographic and radiographic projections, but this data losing the third dimension, with some errors in the picture dimension by optical camera (8, 10). with the development of the scientific researches, using computerized measures provide an accurate description of normal palatal size and shape (11-13). (1)lecturer. department of prosthodontics, college of dentistry, baghdad university. till now, there were so little methods measuring surface area of dental arch specifically, so in this study, the surface area of maxillary dental cast had been calculated directly by mathematical equation and compared with the computerized digital method using threedifferent final impressions to compare surface area data between these different dental casts related to each materials, age, sex of the patients and morphology of the palate were also evaluated. materials and methods sample sixty upper dental casts for twenty patients were made, (12 males, and 8 females). each subject should have a healthy palatal tissue; with no evidence of trauma, injury, or deformity to be included in this research. every patient had received a three different types of final impression materials for his upper casts; zinc oxide eugenol (ss white), additional silicon (hydrophilic vinylpolysiloxane addition silicon impression material) (zhermack, elite p&p), and polyether (3m espe, impregum tm.soft). each material was mixed and submitted to the trays according to their mixing, working, and manipulating time of manufactures specific for each material. these threedifferent final impression materials were selected because of their properties of dimensional stability and accurate restoration of details (14-16). after setting of these impression materials inside the patient mouth, maxillary cast were made with dental stone type iv(zhermack, elite rock), this type of stone has a characteristics of surface accurate details (15, 17). j bagh college dentistry vol. 25(2), june 2013 surface area measurements restorative dentistry 37 digitalization of maxillary casts and mathematically equation: the method was derived from the original description made by ferrario et al (18)and hamdi et al (2) , on each cast, the intersections of lines were drawn as fellow land marks; straight line between the most anterior base of labial frenum and most posterior palatal foveae and this represent the length of cast (l) along the median palatine line; width (w) is represent the average of straight lines( about six readings) distributed in anteroposterior direction along the denture supporting area; and(h) is the average height of the crest of the ridge relative to the corresponding point on the median palatine line (average of six readings evenly distributed in an anteroposterior direction) fig (1). with the current technology that provide a computerized digitizers that can directly used on dental casts to supply metriccordinates of selected land marks. in this study we use the ordinary scanner to take a picture with its original dimensions of the casts without any change in the optimization or resolution readings of any indirect optical photo device, these pictures were directly evaluated and measured through data analyzed in the computer (9,18). approximation formula was developed that expressed the maxillary denturesupporting area (ad) as a function of three distances between anatomic landmarks (2, 3): ad= πl w/6 + 5l [ (πh / 4) 2 + (w/6)2 ]½ this mathematical equation was computerized and data were obtained. use of aluminum foil to measure surface area: for each patient a final impression of zinc oxide eugenol, additional silicon, and poly ether materials for maxillary arch were poured with dental stone type iv to obtain a master model. according to salman,s theory(4); an outline representing the extension of the upper denture base was marked on the model) , the line was passed through buccal and labial sulcus and extended onto the palatal area representing the posterior extension of the denture base. an aluminum foil of (29.12) µm thickness was adapted to the model within the determined outline without any bending of the foil, this was obtained by cutting the foil to six pieces to avoid folds fig (2) , for measurement of the surface area of the denture bearing mucosa the following equation was followed (19): surface area of denture weight of al. foil pieces (mg) bearing mucosa (cm) 2 = weight of 1 cm2 al. foil piece (mg) the weight of aluminum foil piece could be obtained by weighting the cut pieces of aluminum foil using amput analytic balance , fig (3), while the weight of 1cm2 aluminum foil piece was equal to (3.33) mg/ cm2. measurements of the foil were calculated at the ministry of science and technology at the department of measurements. statistical analyses statistical measurements were analyzed to assess the results of the present study; descriptive statistics: mean (m) and standard deviation (sd) were assessed for both variables age and sex for both digitalized computer method and the aluminum foil method. the analysis of variance (anova) and multiple comparisons, with p= 0.05 as a significant level of difference were performed. results table (1) and (2) were shown the descriptive mean and standard deviation of the digitalized method and the aluminum foil method for both variables; age and sex. table (3) and (4) showed that there was no significant differences between the three different final impressions; zinc oxide eugenol, additional silicon, and poly ether materials in surface area measurements for both methods of measuring (digitalized and aluminum foil method (p≥0.05). table (5) with (anova) test analysis showed that there was a highly significant difference in readings between the first method (al. foil) and second method (digitalized computer) with p value of (≤ 0.01). table (6) showed the descriptive analysis of surface area for both two different distinguished area forms in this study; oval and tapered arch form, this table showed that most females with tapering arch form and smaller surface area measurements than males with oval arch form and larger size of surface area measurements. discussion the proportional area of the ridge and the palate to the total denture foundation area may be of considerable significance in the retention and stability of maxillary complete denture and to measure this basal seat area is of considerable importance to evaluate possible meanings of increasing such variable prosthetic properties (2,7,8). measurements of upper surface area of dental cast were evaluated in this study by using two different measuring methods. the first method is to measure the area of upper basal seat by using j bagh college dentistry vol. 25(2), june 2013 surface area measurements restorative dentistry 38 mathematic equation and measuring the corresponding data directly on the upper stone cast. the second method was to measure the maxillary surface area by using the digitalized scanner device and three different final impressions were used in this study; zinc oxide euogenol, additional silicon and poly ether materials to compare the difference in measurements of surface area between these three different materials. data obtained from this study showed that both the direct aluminum foil method and the digitalized method were of similar results; that surface area measurements for zinc oxide euogenol, additional silicon, and poly ether materials were of non-significant differences between them and this results revealed the fact that these materials showed almost a similar accurate details in stone cast registrations (16,20-22). the use of two different methods to measure the upper basal seat area of the denture corresponding to the maxillary cast showed a highly significant difference between the aluminum foil method and the newly digitalized method, this result came in agreement with the fact of the need for newly computerized device is nowadays widely used because of their best detailed image, less time consuming and more accurate measurements with less error accumulation than the direct distance measurements (7,23,24), also difference in the measuring between these two different method; that aluminum foil method give an three distance measurements of length, width and height directly from the cast but with error identification of percentage more in landmark identification than for the landmark digitalization for the same cast (8, 18, 28). age, sex, and palatal morphology were also evaluated in this study, that these three factors of great importance for definitive diagnosis and optimal prosthetic goals (26,27). the changes of oral structures (both dental and skeletal) still continue to modify; and as expected the changes occurring as slower rate than the observed during the first two decade of life (15,27). in this investigation, the results showed that the age variable show a significant difference for both types of measuring methods for the different three final impressions (p≤0.05), this results come in agreement with the findings of harris and bondvik (15) who reported that hard palatal tissue dimensions showed increased in dental arch with aging, but disagreed with the results found by bishara et al who found that decrease in dental arch measurements with aging, and this may be due to the different techniques and materials used in this study (15,28). surface area measurements in women were of non-significant difference than mean, this came in agreements with the findings of ferrario et al who found that both males and females had the same experience of dental arch measurements (8,27). carrillo et al found that males had longer diameters of dental arch than females, this difference in findings may related to the different ethnic groups shared in these different investigations (26) arch form was also discussed in this study that oval shape arch shape showed larger surface area dimensions than that of tapered arch forms, this results agreed with all investigations that under taken to discuss the palatal arch form (6,11,18,26). references 1. nallaswamy d. textbook of prosthodontics. 3 rd ed. new delhi: jaypee brothers publishers; 2005. p. 22 25. 2. mohamad h, johnston wm, obrien wj. empirical equation for estimating the area of maxillary edentulous jaw. j dent res 1973; 52(4): 725-730. 3. craic rg, berry gg, peyton fa. physical factors related to dental retention. j prosthet dent 1960; 10: 459-467. 4. salman ym. effect of denture adhesives on the retention of maxillary complete denture. a master thesis, department of prosthodontics, college of dentistry, university of baghdad, 2001. 5. shay k. cited from boucher's prosthodontic treatment for edentulous patients.11th ed. st. louis: mosbyyear book inc;1997. 6. dostalova t, racek j, tauferova e, smutny v. average arch width and associated changes between initial, post-treatment, and post-retention measurements. braz dent j 2004; 15(3): 218-221. 7. adaskevecius r, vasiliauskas a. evaluation of dental arch form using 3d dental cast scanner technology. electronics and electrical engineering 2009; 5(93): 99-102. 8. ferrario vf, sforza c, schmitz jh, colombo a. quantitative description of the morphology of the human palate by a mathematical equation. cleft palatecranio facial j 1998; 35(5): 396-401. 9. persson a, andersson m, oden a, sandborghenglund g. a three dimensional evaluation of a laser scanner and a touch probe scanner. j prosthet dent 2006; 95(3):194-200. 10. kamegawa m, nakamura m, tsutsumi s. 3d morphological measurements of dental cast with occlusal relationship using micro focus x-ray ct. dent mater j 2008; 27(4): 549-554. 11. lun-jou lo, fen-hwa wong, yu-ray chan, wenyuan lin, ellen wen-ching ko. palatal surface area measurements: comparison among different cleft types. annals plastic surg 2003; 50(1): 18-24. 12. rangel fa, maal tjj, berge sj, vanvligmin ojc, schutyser f, kuijpers-jagtman am. integration of digital dental casts in 3-dimensional facial photographs. am j orthod dentofac orthop 2008; 134: 820-826. (ivsl). j bagh college dentistry vol. 25(2), june 2013 surface area measurements restorative dentistry 39 13. kojima t, sohmura t, wakabayashiti k, kinuta s, takahashi j. computer assisted morphological analysis of dental casts with maxillary prognathism and reversed occlusion j oral rehabil 2004; 31: 2934. 14. lee ea. predictable elastomeric impressions in advanced fixed prosthodontics: a comprehensive review. pract prieodont aesthet dent 1999; 11(4): 497-504. 15. mandikos mn. poly vinyl siloxane impression materials: an update on clinical use. australian dental j 1998; 43(6):428-434. 16. vakay rt, kois jc. universal paradigms for predictable final impressions. compendium j 2005; 26(3): 81-87. 17. butta r, tredwen cj, nesbit m, moles dr. type iv gypsum compatibility with five addition reaction silicon impression materials prosthet dent 2005; 93(6): 540-544. 18. ferrario vf, sforza c, poggio ce, tartaglia g. mathematical definition of the shape of dental arches in human permanent healthy dentitions. cleft palate cranio-facial j 1998; 35:9-15. 19. lathra sp. measurements of maxillary basal seat for dentures. j prosth dent 1973; 30(1): 25-27. 20. adriana cl, renata cs, anapaula m, maria dc, ricardo fr. accuracy of stone casts obtained by different impression materials. brazilian oral research 2008; 22(4):98-108. 21. petropoulos vc, rashedi b. current concepts and techniques in complete denture final impression procedures. prosthodontics 2003; 12(4): 280-287. 22. reddy ss, rakesh n, kaushik a, devaraju d, kumar bsn. evaluation of the accuracy, precision and validity of hydrophilic vinyl poly siloxane impression material for bite mark analysis. excli j 2011; 10: 5561. 23. holst s, blatz mb, eitner s. precision for computer guided implant placement: using 3d planning software and fixed intraoral reference points. j oral maxillofac surg 2007; 65: 393-399. 24. uchida y, katsuki t.measurement of maxillary sinus volume using computerized tomographic images. int j oral maxillofacial implant 1998; 13: 811-818. 25. kuroda t, motohashi n, tominaga r, iwata k. three dimensional dental cast analyzing system using laser scanning. am j orthod dentofac orthop 1996; 110(4): 365-369. 26. edith lc, juan cgp, toshio kl, norma mm, gema ie. dental arch morphology of mazahua and mestizo teenagers from central mexico braz j oral sci 2009; 8(2): 62-98. 27. lee rt. arch width and form. am j orthod dentofac orthop 1999; 115: 305-313. 28. bishara se, jacobson ar, nowak a. arch width changes from 6 weeks to 45 years of age. am j orthodont dentofac orthop 1997; 111:401-409. table 1: descriptive of first and second methods z s p first method mean 42.692 40.090 35.786 sd 6.8991 5.7040 7.6488 second method mean 42.058 39.330 46.412 sd 9.8384 8.6289 9.2620 age mean 64.2 sd 8.343 figure 1: average of six readings evenly distributed in an anteroposterior direction figure 2: cutting the foil to six pieces to avoid folds. figure 3: amput analytic balance j bagh college dentistry vol. 25(2), june 2013 surface area measurements restorative dentistry 40 table 2: descriptive of first and second methods by sex genders method z s p first method mean 45.211 41.791 38.121 males sd 6.063 4.868 8.058 second method mean 48.01 44.23 40.97 sd 7.061 7.139 8.926 age mean 66.7 sd 8.026 females first method mean 38.91 37.53 32.284 sd 6.649 6.2168 5.7782 second method mean 33.12 31.969 29.576 sd 5.679 4.333 4.3128 age mean 60.4 sd 7.781 table 3: lsd of the two methods between the different final impressions first method second method p sig p sig z&s 0.009 s 0.007 s z&p p≤0.01 hs p≤0.01 hs s&p 0.008 s 0.026 s table 4: t-test between first for the different final impressions t-test p-value sig z 0.313 0.758 ns s 0.380 0.709 ns p 0.309 0.761 ns table 5: anova test between the first and second methods f-test p-value sig first method 13.829 p≤0.01 hs second method 12.955 p≤0.01 hs table 6: mean values between male and female according to the arch form arch form male arch form female first method mean z 45.211 38.91 s 41.791 37.53 p 38.121 32.284 second method z 48.01 33.12 s 44.23 31.969 p 40.97 29.576 zienab.doc j bagh college dentistry vol. 28(1), march 2016 color stability pedodontics, orthodontics and preventive dentistry 164 color stability of different aesthetic archwires (an in vitro study) zainab th. noori, b.d.s. (1) nidhal h. ghaib, b.d.s., m.sc. (2) abstract background: coated aesthetic archwires are currently the existing solutions for the esthetic problem, but the color of these archwires tends to change overtime. this study was aimed to evaluate the color stability of different types of esthetic archwires from four different companies at different time periods after immersion of two different staining drinks which are tea and pepsi cola. materials and methods: 48 specimens were prepared, each specimen contains 10 aesthetic archwires; and were divided according to type of solution into two groups: a (tea) &b (pepsi cola); each group contained 24 specimens (12 specimens were immersed in the staining solution as 4 specimens for each time intervals and 12 specimens were immersed in distilled water as control group). each subgroup contains one specimen from each company. color measurements were performed by means of a computed spectrophotometer according to the commission internationale de i’eclairage l*a*b* system, and color changes (δe*) and national bureau of standards units. results: both staining solution caused color change in variable degree and the higher amount of color instability was found for the archwires from the hubit company while the least amount of color change was for the archwires from the orthotechnology company. conclusion: the tea caused highly significant change on the aesthetic archwires which is higher than the effect of the pepsi cola. key words: color stability, aesthetic archwires, staining drinks. (j bagh coll dentistry 2016; 28(1):164-168). introduction esthetic of the patient, is one of main concerns during orthodontic treatment. there is a growing demand for esthetic appliances because most fixed orthodontic appliance components are metallic and silver in color, the demand for esthetic orthodontic appliances is increasing, and the development of materials that present an acceptable esthetics for the patients and an adequate clinical performance for clinicians is needed, this demand has led to the development of orthodontic appliances that had an acceptable esthetics both for patients and clinicians (1,2). the problem has been partially solved by the introduction of esthetic brackets made of ceramic or composite, which are becoming more popular. however, most archwires are still made of metal such as stainless steel and nickel-titanium. a number of alternatives have been explored to create an esthetic archwire that would allow efficient orthodontic treatment from the labial aspect (3,4). metallic archwires coated with toothcolored resin materials, such as synthetic fluorinecontaining resin or epoxy resin composed mainly of poly-tetra-fluoro-ethylene, are currently the existing solution to this esthetic problem, ideally, the color of esthetic archwires should match that of natural teeth and esthetic brackets (5-7). (1)master student. department of orthodontics, college of dentistry, university of baghdad. (2)professor. department of orthodontics, college of dentistry, university of baghdad. the color stability of esthetic archwires during orthodontic treatment is clinically important, any staining or discoloration or change in esthetic of patient will affect the cooperation and acceptance to his treatment, color instability of these wires and exposure of the underlying metal is also often reported. it has been found that 25% of coating is lost in 33 days intra-orally, therefore, the wire becomes aesthetically degraded (8). coating improves esthetics but has some disadvantages, the color tends to change with time coat as “un-durable”, like other esthetic orthodontic products, and there are internal and external causes for the discoloration of esthetic archwires (9). external discoloration can be caused by food dyes and colored mouth rinses, the type of coating material and its surface roughness play decisive roles in the extent of the discoloration caused by diverse substances. the amount of color change can be influenced by a number of factors, including oral hygiene and water absorption (10). materials and methods the samples in this study, four brands of esthetic archwires were assessed. the brands, cross section size, composition, and coating surfaces are shown in table 1, as described by the manufacturers. j bagh college dentistry vol. 28(1), march 2016 color stability pedodontics, orthodontics and preventive dentistry 165 table 1: characteristics of the esthetic archwires used in the study company cross section size coating type composition hubit company / korea 0.019 * 0.025” polytetrafluoroethylene stainless steel dany bmt company / korea 0.019 * 0.025” polytetrafluoroethylene stainless steel orthotechnology company / u.s.a. 0.019 * 0.027” epoxy stainless steel g &h wire company / u.s.a. 0.019 * 0.025” epoxy stainless steel twelve samples from each company were prepared; each sample was made by cutting the preformed archwires into two halves, then placing ten halves of the coated archwires segments together and uniting there free ends first by the light cure composite resin because it has quick set so it makes it easier to use the ethyl cyanoacrylate (ameer) for more fixation so that the sample resemble a strip (see figure 1). figure 1: the samples resemble strips staining solution preparation a standard solution of tea was prepared so that five tea bags of a commercial brand (ahmad tea company; tea bags / london; england.) was boiled in 500 milliliters of distilled water for 4 minutes after beginning of boiling and allowed to cool at room temperature (about 30º c). the solution was replaced four times daily 6 hours each to prevent the precipitation and change in concentration. cans of pepsi cola were used at the room temperature (about 30º c); they were replaced twice daily to prevent the precipitation. baseline color measurements the color was assessed using a spectrophotometer with xenon lamp as light source, according to commission internationale de l’eclairage (translated as the international commission on illumination) cie 1976 l*a*b’* color space system. after numbering the specimens of each subgroup from 1 to 4 for tea and 1 to 4 for pepsi cola by the marker pencil which couldn’t be removed by the solutions, they were incubated in distilled water in glass container at 37°c for 24 hours using incubator, baseline measurements was done to measure the light reflection of each specimen by spectrophotometer at visible wavelengths started from 400-700nm at 10nm intervals so for each specimen, thirty one value of light reflection were obtained (11) (see figure 2). figure 2: the sample in the spectrophotometer (uv-1800 shimadzu / japan) the result converted to cie color system, (matlab 8 software, r2012b, 2012/ usa) was used to obtain the values for x, y and z obtained. the cie system uses three-dimensional colorimetric measurements: l* values correspond to the brightness of a color, a* values to the redgreen content, and b*values to the yellow-blue content (12). then the l*, a* and b* were calculated by the following formula: measurement of the color change after immersion in the staining solutions the samples were placed in a glass container with the prepared staining solutions (tea and pepsi cola), then incubated in the incubator at 37º c. color measurements were repeated after 7 days (t1), 14 days (t2), and 21 days (t3) of immersion in the solution; the solutions was replaced four times daily at each six hours. before each measurement, samples were removed from the solution and rinsed with distilled water for 5 minutes. excess water on the surfaces was removed with tissue papers, and the samples were allowed to dry. then the l*, a*and b* values of each specimen after immersion in j bagh college dentistry vol. 28(1), march 2016 color stability pedodontics, orthodontics and preventive dentistry 166 treatment solutions were measured. the color difference between baseline measurement and measurement after immersion in solution as follows: δ l* = l2 _ l1 δ a * = a 2 – a1 δ b* = b2 – b1 then the total color dereferences δ e* for each specimen (distance between the 2 point in color space) were calculated by following equation: the δ e* of each subgroup was compared with others, to distinguish which type of coating material was more unstable in color and which staining solution cause more color change in aesthetic archwires. to relate the amount of color change (δe*) to a clinical environment, the data were converted to national bureau of standards (nbs) units (13) as the following: nbs units = δ e* × 0.92 the definitions of color changes quantified by nbs units were used. these values were suggested by koksal and dikbas (14). statistical analysis 1. descriptive statistics including mean, standard deviation, maximum, minimum, and standard error. 2. inferential statistics: including: one way analysis of variance (anova) to test any statistically significant difference among the light reflection of groups and least significant difference (lsd) to test any statistically significant differences between each two subgroups when anova showed a statistical significant difference within the same group. significance for all statistical tests was predetermined at p ≤ 0.05. results table 3 shows the total color difference (δl*, δa*, δb*) of the aesthetic archwires after 21 days of immersion in the staining solution. and table4 shows the total color difference (δe*) of the aesthetic archwires after 21 days of immersion in the staining solution. both solutions (tea and pepsi cola) caused color change in variable degree for all companies; the tea caused a large amount of color change than pepsi cola, with highly significant change for all companies, while pepsi cola caused significant change. hubit company has the highest δe* after immersion in tea and pepsi cola (table 5); orthotechnology company has the lowest δe* after immersion in pepsi cola (table 6). the amount of color change increased with time, but the great amount of change occurs in the first week then the staining progress in slower rate. table 3: descriptive statistics of δl*, δa*, δb* values of the four companies and for both staining solution (tea and pepsi cola) after all time interval 1: dany company 2: g&h company 3: hubit company 4: orthotechnology company subgroup descriptive statistics δl* δa* δb* mean sd min. max. mean sd min. max. mean sd min. max tea 1 -13.56 2.563 -18.31 -9.305 2.164 0.445 -1.57 5.382 1.190 0.37 -6.53 5.28 2 -16.53 2.924 -22.15 -12.924 1.555 0.533 -0.30 4.162 3.062 0.908 -0.83 6.37 3 -17.83 1.347 -20.70 -16.211 -7.556 1.451 -8.75 -3.163 33.14 5.436 17.09 36.8 4 -9.817 0.263 -16.95 -4.976 -0.029 0.008 -1.80 10494 1.056 0. 62 -2.06 7.76 pepsi cola 1 -6.578 1.273 -8.471 -4.523 0.014 0.005 -0.85 1.364 0.721 0.087 -2.74 -2.74 2 -7.832 2.873 -11.76 -2.045 0.774 0.025 0.164 1.698 -1.00 0.944 -3.05 -0.13 3 -11.93 0.843 -13.00 -10.598 -0.233 0.031 -0.91 0.509 -1.54 0.050 -4.02 0.51 4 0.855 0.137 -3.958 3.365 -1.251 0.015 -2.79 -0.004 2.163 0.153 -2.79 5.04 j bagh college dentistry vol. 28(1), march 2016 color stability pedodontics, orthodontics and preventive dentistry 167 table 4: descriptive statistics of δe* values of the four companies and for both staining solution (tea and pepsi cola) after all time interval subgroup descriptive statistics δe* mean sd min. max. tea 1 14.056 2.986 9.383 19.751 2 19.461 3.261 15.74 25.689 3 39.687 4.244 27.297 42.899 4 17.225 4.218 3.618 19.214 pepsi cola 1 6.847 1.301 4.966 8.891 2 9.898 1.947 6.247 13.303 3 11.983 0.882 10.6 13.176 4 3.256 0.737 2.119 4.608 table 5: anova test results for δe* values for all time interval of dany company after immersion in pepsi cola and tea sig p-value f-test media hs p<0.01 18.685 tea s 0.01 8.960 pepsi table 6: anova test results for δe* values for all time interval of orthotechnology company after immersion in pepsi cola and tea sig p-value f-test media s 0.049 2.818 tea hs p<0.01 13.394 pepsi discussion color changes were characterized by using the cie l*a*b* color space. the cie l*a*b* color space is currently one of the most popular and widely used systems of color measurement, and it is well suited for the determination of small color differences (15). when compared the l*, a* and b* values of each company, the results found that means of l* values of all companies were decrease after immersion in both treatment solutions (δl* negative), because all of the specimens became darker after immersion in solutions, except for the orthotechnology company after immersion on pepsi cola which had δl* positive; when compared δe* of all the companies , we found that the highest change on color occurred at the end of the 3rd week , which means that it increased with time , but the greater change from the basic measurement occur on the 1st week, then the change in color progress in slower rate. the present study shows that there are differences in the amount of color change of the difference aesthetic archwires from different companies under the same circumstances; this may be related to the chemical and physical composition of the aesthetic archwires which need further investigations to each company to discover out the cause of this variation (16-18). the difference between the two staining solution (tea and pepsi cola) is related to the composition of these solution. there is difference in the caffeine content between the two solutions, each 8 oz. (237 ml) of black tea contain about 1470 mg of caffeine while each 12 oz. (355 ml) of pepsi cola contain about just 32-39 mg of caffeine(19,20). the pepsi cola contain also carbonated water (soda), phosphoric acid, citric acid that may have some cleaning action, while the tea contain some precipitation from the tea leaves that will increase the staining effect (21-23). references 1. elayyan f, silikas n, bearn d: ex vivo surface and mechanical properties of coated orthodontic archwires. eur j orthod 2008; 30:661–7. 2. kaphoor aa, sundareswaran s. aesthetic nickel titanium wires-how much do they deliver. eur j orthod 2012; 34:603-9. 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27(l):139-44. 16. da silva dl, mattos ct, de araujo mv, de oliveira ruellas ac. color stability and fluorescence of different orthodontic esthetic archwires. angle orthod 2013; 83:127-32. 17. mccusker rr, et al. caffeine content of specialty coffees. j analytical toxicology 2003; 27: 520. 18. mccusker rr, et al., caffeine content of decaffeinated coffees. j analytical toxicology. 2006; 30: 611. 19. mccusker rr, et al. caffeine content of energy drinks, carbonated sodas, and other beverages. j analytical toxicology 2006; 30:112. 20. chin jm, et al. caffeine content of brewed teas. j analytical toxicology 2008; 32:702. 21. heckman ma, et al. caffeine (1,3,7trimethylxanthine) in foods: a comprehensive review on consumption, functionality, safety, and regulatory matters. j food science. 2010; 75: r77. 22. neeraj v. pesticides in coca –cola and pepsi cola: consumerism, brand image, and public interest in a globalizing india. cultural anthropol 2007; 22-4: 65984 23. hammer ka, carson cf, riley tv. effects of melaleucaalternifolia (tea tree) essential oil and the major monoterpene component terpinen-4-ol on the development of singleand multistep antibiotic resistance and antimicrobial susceptibility. antimicrobial agents chemotherapy 2012; 56(2): 909. alan f.doc j bagh college dentistry vol. 25(4), december 2013 the prevalence of basic sciences 171 the prevalence of candida spp. in the saliva of controlled and uncontrolled diabetes mellitus type ii patients alan nazar talabani (1) chong lee kim (2) alan ong han kiat (3) abdul rashid ismail (4) karuthan chinna (5) abstract background: diabetes mellitus type 2 has been known for many years as the most common endocrine metabolic disorder that affect the oral cavity and cause many oral diseases including candidiasis. in this study, the incidence of candida spp. in the saliva of controlled and uncontrolled diabetic patients were determined and compared with non diabetic group. material and method: the sample consists of 200 subjects: 100 diabetic patients [57 (28.5%) uncontrolled diabetes, 43 (21.5%) controlled diabetes] and 100 (50%) non diabetic groups. saliva samples was obtained from the subjects and cultured on selective media using appropriate microbiological method to observe the presence of candida spp. results: the results revealed a significant association (p < 0.001) between diabetic patients and the presence of candida spp. using statistical analysis. the odds ratio of the presence of candida spp. in the controlled and uncontrolled diabetic patients were 0.539 (95% ci= 0.193, 1.508).the odds ratio of the presence of candida spp. in the uncontrolled and controlled diabetic patients were 17.433 (95% ci= 7.298, 41.642) and 9.40 (95% ci = 4.068, 21.686), respectively, compared to non diabetic group. a significant association was found between the presence of candida spp. and the following variables: groups (p < 0.000), gender (p < 0.000), smoking (p < 0.000), antibiotics (p < 0.000), oral mouthwash (p < 0.000) edentulous (p < 0.000) and denture wearing (p < 0.000). conclusion: candida spp. population significantly increased in the oral flora of diabetic patients compared with non diabetic group. keywords: diabetes mellitus type ii, controlled and uncontrolled diabetes, candida spp. (j bagh coll dentistry 2013; 25(4):171-176). introduction diabetes mellitus (dm) has been known for many years as the most common endocrine metabolic disorder and its occurrence increased worldwide, it affects about 14 million people in the united states, the number of new cases increases by more than 700, 000 per year (1). the first broadly accepted classification of diabetes mellitus was published by world health organization in 1980 (2). the expert committee proposed in 1980 two main modules of diabetes mellitus and named them, insulin dependent diabetes mellitus (iddm) or type 1, and non insulin dependent diabetes mellitus (niddm) or type 2 (2). basically, this study will be focused only on type 2 dm because patients with this type of dm are suffering from many complications such as neuropathy, nephropathy, blurring vision and oral complications. (1)assistant lecturer, department of microbiology & immunology, school of medical sciences, faculty of medicine, university of sulaimaniayah (2)senior lecturer, department of biotechnology, faculty of science and engineering, malaysia university of science and technology (m.u.s.t) (3)associate professor, department of pre-clinical sciences, faculty of medicine and health sciences, universiti tunku abdul rahman (utar) (4)professor, faculty of dentistry, melaka-manipal medical college (mmmc) (5)associate professor, department of social and preventive medicine, faculty of medicine, university of malaya (um) type ii dm can be classified based on the degree of the disease into controlled diabetes and uncontrolled diabetes based on glycosylated hemoglobin (hba1c) serum levels (3-5). from all the best known systemic diseases, diabetes has been the most frequently blamed as a risk factor for oral pathogenic disorders such as candidiosis (6). the saliva contains a great number of microorganisms (approximately 108 per ml). most of the microorganisms in the saliva are derived from other parts of the oral cavity such as the teeth and oral mucosal surfaces as a result of mechanical abrasion caused by chewing, talking and swallowing. the microvascular changes and possibly increased glucose concentration in the saliva and gingival crevicular fluid which might contribute in declining ph of saliva resulting in acidogenic microorganism substrate and plaque formation. as a result of that, the increased growth of acidogenic microorganisms such as candida albicans will had a prominent role in developing various oral complications (7). based on some studies indicated that the degree of metabolic control may play an important role in the oral manifestations of diabetes whether the type of disease is insulin dependent diabetes mellitus (iddm) or non insulin dependent diabetes mellitus (niddm). the uncontrolled dm may cause tissue j bagh college dentistry vol. 25(4), december 2013 the prevalence of basic sciences 172 destructions leading to advanced periodontal and oral fungal infections. although there are many published reports on the high presence of candida spp. in the oral cavity of diabetic patients than in non-diabetic subjects (8-10), studies regarding the presence of these species in a specific criteria of type 2 diabetes are still unknown. therefore, the aim of this study is to determine the presence of candida spp. in the controlled and uncontrolled diabetes mellitus type ii patients and compare it with non diabetic groups. subjects and methods study groups the data were collected from patients attending the diabetic clinic at hospital university sains malaysia (husm) in kota bahru, malaysia during a period of two months started from 9th january 2011 to 8th march 2011. non-diabetic group subjects were selected after checking their fasting blood glucose from outpatient clinic in school of dental sciences at university sains malaysia (usm). after obtaining the permission from the patients to participate in this study by signing a consent form given to them, data were collected. a total of 100 type 2 diabetic patients (39 males and 61 females) and 100 non diabetic groups (39 males and 61 females) were included in this study based on a sample size formula suggested by daniel (1999) (11). the controlled and uncontrolled type 2 diabetic patients were verified by checking the glycosylated hemoglobin (hba1c) from patient records in the diabetic clinic after taking the permission from the clinic. patients with an average age from 40 – 60 years having type 2 diabetes were included in this study. severally debilitated subjects such as neuropathy and necrosis (gangrene) were excluded from this study after checking their records from the clinic. sample collection swabs were taken from the floor of the mouth of 200 individuals included in the study. the swabs were placed in sterile transport media to maintain the validity of the microorganisms, and then they were transported to the oral microbiology lab at the school of dental science for processing. procedure of culturing and isolating candida spp. the samples were cultured immediately on sabouraud dextrose agar (sda) using streaking method described by (pollack et al., 2002) (12) and incubated aerobically for 48h at 37ºc. after incubation, well isolated colonies were picked up for identification purposes and transferred into a sterile nutrient broth and incubated at 48h at 37ºc. each culture was checked for purity by subculturing it onto another sda plate by transferring 0.1 ml of the sample on to the plate and spread the entire plate using a sterile hokey stick and incubated with the same circumstances. most of the species that have been identified were c. albicans. the growth of candida was identified by smooth, creamy white dots (figure 1. and figure 2.). statistical analysis spss version 14.0 was used for data entry and analysis. the association between the study groups and the presence of candida spp. were compared using chi-square test. univariate logistic regression was used to determine the association between the presences of candida spp. with groups, gender, smoking, alcoholic, antibiotics, oral mouthwash, edentulous and denture wearing. covariates such as age, height and weight are reported as mean ± sd. p ≤ 0.05 was considered statistically significant. figure 1. the growth of candida spp. on sabouraud dextrose agar figure 2. gram positive round candida cells j bagh college dentistry vol. 25(4), december 2013 the prevalence of basic sciences 173 results demographic characteristics in those present study, the majority of diabetic patients were malay (86%) as it is the predominant race in kelantan state were the diabetic disease has been reported to be higher at 10.5% as contrast to 8.2% for the rest of malaysia (13). the distribution of demographic characteristics between the groups is shown in table 1. table 1. demographic characteristics between diabetic and non diabetic groups note. sd= standard deviation, n= number of participants description of diabetic patients most of the subjects were suffering from diabetes less than ten years. all diabetic patients were taking medications except 2 (2%) patients didn't take any medications. of the 100 diabetic patients, 82 (82%) were taking other medications besides medicine for diabetes such as anti hpt, cholesterol and other medications, the description of diabetic patients is shown in table 2. table 2. description of diabetic variables among diabetic patients variables controlled diabetes uncontrolled diabetes n (%) n (%) diabetes duration < 10 years 10 years > 10 years 28 (28) 3 (3) 12 (12) 30 (30) 7 (7) 20 (20) diabetic pills 43 (43) 55 (55) other medications that diabetic patients take 33 (33) 49 (49) note. n= number of participants associations of candida spp. and study groups it was observed that older men patients show significantly higher incidence of candida spp. in the oral flora (p < 0.000). most of the previous studies (14-16) revealed that females are more vulnerable to oral candida than males due to the hormonal factor and the great incidence of iron deficiency that might be responsible for the activity of the yeasts and thus leads to oral lesions (17). however, there is no social or physiological characteristic that could influence the incidence of oral candida among men except for some habits such as smoking that could be the main factor for the presence of some yeast that mainly occurs among men. the prevalence of candida spp. among diabetic patients was higher than that in the non diabetic group. diabetic patients are more vulnerable to oral candida infections than non diabetic groups due to factors that promote oral fungal infections accredited to many reasons including hyperglycemia, xerostomia, variables diabetic group non diabetic group n (%) n (%) gender male 39 (19.5) 39 (19.5) female 61 (30.5) 61 (30.5) race malay 92 (46) 80 (40) chinese 7 (3.5) 8 (4) indian 1 (0.5) 10 (5) others 0 (0) 2 (1) educational level < primary 36 (18) 8 (4) secondary 46 (23) 52 (26) tertiary 18 (9) 40 (20) occupation employee 36 (18) 67 (33.5) housewife 53 (26.5) 30 (15) retired 11 (5.5) 3 (1.5) age (mean ± sd) 58.6 ± 8.7 39.4 ± 14.8 j bagh college dentistry vol. 25(4), december 2013 the prevalence of basic sciences 174 hyposalivation that reduce the salivary flow rate and oral habits. these findings are supported by many studies (8-10,18,19). oral candidiasis, which is a disease caused by the genus candida, is an opportunistic fungal infection generally associated with hyperglycemia and is thus a common complication of marginally controlled or uncontrolled diabetes (20). this statement is supporting the findings of this study that showed controlled and uncontrolled diabetic patients are more prone to oral candidal infections that caused by candida spp. compared to non diabetic group. the results have shown that the odds for the prevalence of candida spp. in the uncontrolled and controlled diabetic patients are 17.433 [95% ci= 7.298, 41.642] and 9.40 [95% ci= 4.068, 21.686] times more, respectively, compared to the non diabetic group. according to a previous study done by hill et al. (21), who studied the association of predisposing factors related to diabetic patients such as glycosylated haemoglobin with oral candida. they found that patients with glycosylated haemoglobin above 12% (considered as uncontrolled diabetic) were strongly associated with oral fungal infection. the odds ratio of hill et al. (21) was 13.00 times more than non diabetic group. the results of this study showed a higher incidence of candida spp. in the uncontrolled diabetic with odds ratio of 17.433 times more compared to non diabetic groups. patients who were uncontrolled diabetes may suffer from many complications including increased glucose level in saliva, decreased saliva secretion, delayed healing and other pathological changes which can contribute to high susceptibility of the oral tissues to infection and local irritants (22). however, the current study didn't found any significant difference in the prevalence of candida spp. between specific criteria of type 2 dm because of the low data that have been collected smoking habit was found to be an important risk factor for prevalence of candida spp. among the subjects. the results of this study have shown a significant association between smoking habit and candida spp. smoking has been known as an important factor in the oral candidal infection (23). this finding is in agreement with khaled et al. (18) who also found a significant association between smoking and the presence of candida spp. (p < 0.001). although, the percentage of smokers among the subjects was low compared to non smokers who were significantly high but it still considered as a risk factor for oral candidal infection. alcoholism is another oral habit which can lead to a variety of oral lesions that caused by candida spp. (24). however, no significant association was found between alcoholism and candida spp. in this study because of the low percentage of alcoholic subjects. therefore, there is a less possibility of considered it a risk factor in this study. the results are also shown a significant association between oral mouthwash and candida spp. (p < 0.000). the number of subjects who were using oral mouthwash or oral rinses were 60 (30%) compared to 48 (24%) of whose who were not using these solutions. although, the presence of candida spp. was less among subjects who were not using mouthwashes in this study, they are still at risk of having oral candidal infections. it is known from the results of this study that there is a significant association between edentulous and the prevalence of candida spp. (p < 0.000). subjects who were edentulous showed a high percentage of candia spp. 72 (36%) in their oral cavity compared to those who were not edentulous 36 (18%). according to price et al., 1982, common oral complications are associated with diabetes include tooth loss, gingivitis, periodontitis and pathological changes of oral soft tissues. this statement is in agreement with the results of this study. patients who wear dentures in their oral cavity, associated with the limited changes of the oral mucosa and the systemic complications, are more susceptible to candida infections (15). a significantly higher incidence of candida infection and increased levels of candida spp. were found in diabetic patients wearing removable dentures (6,21, 25). these findings are in agreement with the results of this study that shows a significant association between candida spp. several complications may occurs in patients who wears removable denture such as the decrease of salivary ph and saliva flow rate that slow down the mechanical cleaning process of the soft tissue surfaces by the tongue and thus, it reduced the tissue resistance against infections (26). therefore, diabetic patients wearing removable denture in this study are at high risk of having candidal infections in their oral cavity. there was a significant association between the prevalence of candida spp. and antibiotics (p < 0.000) in this study. the results showed the prevalence of candida spp. was higher among subjects who were non taking antibiotics 91 (45.5%) compared to those who were taking antibiotics 17 (8.5%). the ignorance of taking the appropriate antibiotics including antifungal will increase the prevalence of candida spp. and thus, it will lead to oral fungal complications. according to paula et al. (16), the knowledge of antifungal susceptibility testing and the j bagh college dentistry vol. 25(4), december 2013 the prevalence of basic sciences 175 development of new antifungal drugs are compulsory to accomplish a decrease in candida infections and raise the quality of life denturewearing individuals with and without type 2 diabetes mellitus. the association between the presence of candida spp. and variables is shown in table 3. as conclusion; the presence of candida spp. is more frequent among diabetic patients than non diabetic patients. diabetic patients showed a higher incidence of candida spp. than non diabetic group. generally, diabetic patients have a low resistance to infections including oral candidal infections due to suppressed (low) immunity. factors such as smoking, edentulous, and denture wearing are the main factors for the prevalence of candida spp. the refusal to take antibiotics or use oral mouthwashes as recommended by dentists also increases the risk of oral candida infections. further studies on the prevalence of these species among specific criteria of type 2 dm is recommended. table 3: the association between the presence of candida spp. and other variables acknowledgments the author is thankful to the ethical committee at universiti sains malaysia (usm), school of dental sciences at usm, diabetic clinic at hospital universitit sains malaysia (husm) for their support and malaysia university of science and technology (must) for sponsoring this project. references 1. jajarm hh, mohtasham n, rangiani a. evaluation of oral mucosa epithelium in type ii diabetic patients by variables presence of candida spp. crude or 95% ci p value yes no n (%) n (%) group (1) diabetic 82 (41) 18 (9) 12.97 [6.581, 25.546] 0.00 non diabetic 26 (13) 74 (37) group (2) controlled dm 33 (16.5) 10 (5) 9.40 [4.068, 21.686] 0.00 non diabetic 26 (13) 74 (37) group (3) uncontrolled dm 49 (24.5) 8 (4) 17.433 [7.298, 41.642] 0.00 non diabetic 26 (13) 74 (37) group (4) uncontrolled dm 49 (24.5) 8 (4) 0.539 [0.193, 1.508] 0.17 controlled dm 33 (16.5) 10 (5) gender male 64 (32) 13 (6.5) 8.84 [4.385, 17.818] 0.00 female 44 (22) 79 (39.5) smoking yes 28 (14) 0 (0) 2.150 [1.832, 2.524] 0.00 no 80 (40) 92 (46) alcohol consumption yes 2 (1) 0 (0) 1.87 [1.641, 2.127] 0.19 no 106 (53) 92 (46) on antibiotics yes 17 (8.5) 0 (0) 2.011 [1.738, 2.326] 0.00 no 91 (45.5) 92 (46) oral mouthwash yes 60 (30) 24 (12) 3.542 [1.943, 6.457] 0.00 no 48 (24) 68 (34) edentulous yes 72 (36) 0 (0) 3.556 [2.695, 4.690] 0.00 no 36 (18) 92 (46) denture wearing yes 65 (32.5) 0 (0) 3.140 [2.453, 4.014] 0.00 no 43 (21.5) 92 (46) j bagh college dentistry vol. 25(4), december 2013 the prevalence of basic sciences 176 an exfoliative cytology method. j oral sci 2008; 50(3): 335-40. 2. who. who expert committee on diabetes mellitus. geneva: who, 1980 contract no.: second report. 3. tavintharan s, chew h. a rational alternative for diagnosis of diabetes mellitus in high risk individuals. ann acad med singapore 2000; 29(2): 8-213. 4. ehab hn, ghada mm. uncontrolled diabetes mellitus and fetal heart. researcher 2010; 2(5): 45-55. 5. ahmed s, elbakry a, hamed h, emad m. psychosocial profile of adolescent patients with diabetes mellitus. current psychiatry 2010; 17(4): 4756. 6. akpan a, morgan r. oral candidiasis: a review. postgrad med j 2012; 78: 455-9. 7. touger h. dental care and patients with diabetes. gaithersburg, us: gaithersburg aspen publishers; 1996. 8. kumar bv, padshetty ns, bai ky, rao, ms. prevalence of candida in the oral cavity of diabetic subjects. japi 2005; 53: 599-602. 9. hintao j, teanpaisan r, chongsuvivatwong v, ratarasan c, dahlen g. the microbiological profiles of saliva, supragingival and subgingival plaque and dental caries in adults with and without type 2 diabetes mellitus. oral microbiol immunol 2007; 22: 175-81. 10. varin ta. oral findings and oral microflora in type 2 diabetes mellitus in sulaimani city. a master thesis, university of sulaimani, iraq, 2010. 11. daniel ww. biostatistics: a foundation for analysis in the health sciences 7th ed. new york: john wiley & sons; 1999. 12. pollack ra, lorriane f, walter m, ronald rm. laboratory exercises in microbiology. 2nd ed. hoboken, nj: john wiley & sons; 2002. 13. mafauzy m. diabetes mellitus in malaysia. med j malays 2006; 61: 397-8. 14. de resende, ma, de sousa lv, de oliveria rc, kogalto cy, lyon jp. prevalence and antifungal susceptibility of yeasts obtained from the oral cavity of elderly individuals. mycopathologia 2006; 162: 168-76. 15. khosravi ar, yarahmadi s, baiat m, shokri h, pourkabireh m. factors affecting the prevalence of yeasts in the oral cavity of patients with diabetes mellitus. j mycol med 2008; 18: 8-83. 16. paula vs, eunice tg, ewerton go, carlos ev. candidia spp. prevalence in well controlled type 2 diabetic patients with denture stomatitis. ooooe. 2011; 111: 726-33. 17. espinoza i, rojas r, aranda w, gamonal j. prevalence of oral mucosal lesions in elderly people in santiago, chile. j oral pathol med 2003; 32(10): 5715. 18. khaled h, mawieh a, suleiman a. prevalence of oral candida infections in diabetic patients. bahrain medical bulletin 2006; 28(1). 19. siribang pk, tongchat s, soisiri t, somsak m, umawadee c, weerapan k. xerostomia, hyposalivation, and oral microbiota in type 2 diabetic patients: a preliminary study. j med assoc thai 2009; 92(9): 1220-8. 20. guggenheimer j, moore pa, rossie k. insulindependent diabetes mellitus and oral soft tissue pathologies, ii: prevalence and characteristics of candida and candidal lesions. ooooe 2000; 89:6570. 21. hill lv, tan mh, pereira lh, embil ja. association of oral candidiasis with diabetic control. j clin pathol 1989; 42: 502-5. 22. sykes lm, sukha a. potential risk of serious oral infections in the diabetic patients: a clinical report. j prosthet dent 2001; 86: 569-73. 23. fongsmut t, deerochanawong c, prachyabrude w. intraoral candida in thai diabetes patients. j med assoc thai 1998; 81: 449-53. 24. rajan s, sadeq a, deepti s, noorliza m, abdul rashid i. oral mucosal lesions in non oral habit diabetic patients and association of diabetes mellitus with oral precancerous lesions. diabetes res clin pract 2010; 83(3): 320-2. 25. daniluk t, tokajuk g, stokowska w, fiedoruk k, sciepuk m, zaremba ml, et al. occurance rate of oral candida albicans in denture wearer patients. adv med sci 2006; 51 suppl 1: 77-80. 26. budtz-jorgensen e. histopathology, immunology and serology of oral yeast infections, diagnosis of oral candidosis. acta odontol scand 1990; 48: 37-43. karawan f.docx j bagh college dentistry vol. 28(2), june 2016 a comparative study oral diagnosis 52 a comparative study of immunohistochemical expression of moesin, cytokeratin 14 andmmp7 in oral squamous cell carcinoma and oral verrucous carcinoma karawan khaleel jubair, b.d.s., m.sc. (1) wasan hamdi younis, b.d.s., m.sc., ph.d. (2) bashar hamid abdulla, b.d.s., m.sc., ph.d. (2) abstract background: squamous cell carcinoma (scc) is the most prevalent malignant neoplasm of the oral cavity that exhibits certain histological variations. verrucous carcinoma (vc) is an uncommon exophytic low-grade welldifferentiated variant of scc. cellular differentiation and morphology play important roles in cell functions and maintenance of structural integrity .as the cancer is a malignant process in which disorder of the cell growth and behavior occurs, such changes may differ in different tumor types and within different grades of the same tumor. materials and methods:forty two formalin – fixed, paraffin – embedded tissue blocks were included in this study (30 blocks were diagnosed as oscc and 12 blocks were diagnosed as ovc). an immunohistochemical staining was performed using anti moesin, anti ck14 and anti mmp7 monoclonal antibodies. results: moesinimmunoreactivity was recognized in all the studied groups with predominant cytoplasmic expression in oscc & membranous expression in ovc. no difference was noticed between 2 studied groups &between different grades of oscc. cytokeratin 14 positivity was noticed in all studied groups with significant difference between oscc&ovc (p=0.012) & there was a significant difference between the different grade of oscc (p=0.047). mmp7 expression was observed in the all studied groups with predominant cytoplasmic pattern in oscc & nuclear pattern in ovc. no difference was found between the 2studied groups &between the different grades of scc. a strong positive linear correlation between mmp7&ck14 was noticed. conclusion: verrucous carcinoma has a specific pattern for moesin and mmp7 that differs from oscc, however; the difference is not significant. ck14 immunoreactivity indicated a significant difference in the degree of cellular differentiation between oscc &ovc. keywords: oral squamous cell carcinoma,oral verrucous carcinoma, moesin,ck14,mmp7. (j bagh coll dentistry 2016; 28(2):52-57). introduction the most common oral cancer (oc) of epithelial origin is oral squamous cell carcinoma (oscc) which is the most frequent malignant neoplasm of the oral cavity, corresponding to almost 95% of all lesions and to about 38% of malignant tumors of the head and neck (1). oral verrucous carcinoma (ovc) is an uncommon exophytic low-grade well-differentiated variant of squamous cell carcinoma. it is well known for its locally aggressiveness and for its clinically slowgrowing behavior with minimal metastatic potential and represent 0.3% to 10% of all oral cavity scc (1). oscc is different from ovc in its clinical and histopathological aspects, as well as in its prognosis (2). several physiologic functions including cell shape, adhesion and motility require a connection between cell membrane proteins and the cortical cytoskeleton (3). a subgroup of superfamily, ezrin-radixinmoesin (erm), is known to function as a link between the cell membrane and actin cytoskeleton (4). altered expression of particular erm proteins is believed to contribute to carcinogenesis and metastasis (5,6). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. a well controlled balance of cellular proliferation and differentiation is necessary for the development and maintenance of normal epithelium throughout the body. keratins are cytoplasmic intermediate filament proteins (7), that regulate/modulate different signaling pathways associated with various cellular processes such as protein synthesis, cell growth, and cell differentiation (8,9). several cellular alterations occur in the cytoskeleton during oncogenic development that can be assessed through the expression of these proteins (10). degradation of the basement membrane and invasion of the underlying connective tissue by neoplastic cells are recognized as fundamental steps in the progression of many epithelial cancers. mmp-7 (matrilysin) is among the smallest members of the mmp family, has the capacity to start an activation cascade of mmps and is able to degrade a variety of extracellular matrix (ecm) substrates (11). tumor growth and progression depends critically on the ability of tumor cells to proliferate, cell motility, receptors mediated cell adhesions, production of proteolytic enzymes, and certain extracellular matrix proteins. moesin, cytokeratin 14 and mmp7 will be used in this study to show the degree of cellular changes, j bagj bagh college dentistry oral diagnosis assessing tumor behav comparing these biological parameters in oscc and ovc. this study aimed to immunohistochemical expression of ck14, moesin and mmp7 in oral squamous cell carcinoma and verrucous carcinoma correlate their histopathological grading. materials and methods forty two formalin embedded tissue blocks (30 oscc and 12 ovc) were collected from labrotaries archives and included in this study. reassessment of sections for each block four mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies mmp7 monoclonal abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit ab80436, cambridge, uk) results the age of the studied samples ranged between 24 15.3 years in scc whi in ovc. male predominance was found with 60% of scc group and 75% of vc group. no statistically significant differences in age and sex distribution were observed between the 2 studied groups (table 1). the most affected site 26.7% (8 cases) while buccal mucosa and alveolar ridge 33.3% (4 cases for each) were the common sites in ovc. histopathological examination showed that 14 cases (46.7%) were well differentiated scc, 12 cases (40%) moderately differentiated and 4 cases (13.3%) were poorly differentiated moesinimmunoreactivity was recognized in all the studied groups with predominant cytoplasmic expression in scc and membranous expression in ovc(table 3and figure1). h college dentistry oral diagnosis assessing tumor behav comparing these biological parameters in oscc and ovc. this study aimed to immunohistochemical expression of ck14, moesin and mmp7 in oral squamous cell carcinoma and verrucous carcinoma correlate their histopathological grading. materials and methods forty two formalin embedded tissue blocks (30 oscc and 12 ovc) were collected from labrotaries archives and included in this study. reassessment of haematoxylin& eosin stained sections for each block four micrometer thick sections were cut and mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies using anti moesin, anti ck14 and anti mmp7 monoclonal abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit ab80436, cambridge, uk) results the age of the studied samples ranged between 24-99 years old. the mean age was 59+/ 15.3 years in scc whi in ovc. male predominance was found with 60% of scc group and 75% of vc group. no statistically significant differences in age and sex distribution were observed between the 2 studied groups (table 1). the most affected site 26.7% (8 cases) while buccal mucosa and alveolar ridge 33.3% (4 cases for each) were the common sites in ovc. histopathological examination showed that 14 cases (46.7%) were well differentiated scc, 12 cases (40%) moderately tiated and 4 cases (13.3%) were poorly differentiated (table 2) moesinimmunoreactivity was recognized in all the studied groups with predominant cytoplasmic expression in scc and membranous expression in table 3and figure1). h college dentistry assessing tumor behavior and invasiveness; comparing these biological parameters in oscc this study aimed to immunohistochemical expression of ck14, moesin and mmp7 in oral squamous cell carcinoma and verrucous carcinoma correlate their expression histopathological grading. materials and methods forty two formalin – fixed, paraffin embedded tissue blocks (30 oscc and 12 ovc) were collected from labrotaries archives and included in this study.after histopathological haematoxylin& eosin stained sections for each block. micrometer thick sections were cut and mounted on positively charged slides and stained immunohistochemically with monoclonal using anti moesin, anti ck14 and anti mmp7 monoclonal antibodies abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit ab80436, cambridge, uk) was used. the age of the studied samples ranged 99 years old. the mean age was 59+/ 15.3 years in scc while it was 61.3 +/ in ovc. male predominance was found with 60% of scc group and 75% of vc group. no statistically significant differences in age and sex distribution were observed between the 2 studied the most affected site in scc was the tongue 26.7% (8 cases) while buccal mucosa and alveolar ridge 33.3% (4 cases for each) were the common sites in ovc. histopathological examination showed that 14 cases (46.7%) were well differentiated scc, 12 cases (40%) moderately tiated and 4 cases (13.3%) were poorly (table 2). moesinimmunoreactivity was recognized in all the studied groups with predominant cytoplasmic expression in scc and membranous expression in table 3and figure1). h college dentistry vol. 2 ior and invasiveness; comparing these biological parameters in oscc compare immunohistochemical expression of ck14, moesin and mmp7 in oral squamous cell carcinoma and verrucous carcinoma and to expression with the materials and methods fixed, paraffin embedded tissue blocks (30 oscc and 12 ovc) were collected from labrotaries archives and after histopathological haematoxylin& eosin stained micrometer thick sections were cut and mounted on positively charged slides and stained immunohistochemically with monoclonal using anti moesin, anti ck14 and anti antibodies(abcam uk). abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit (catalog no. was used. the age of the studied samples ranged 99 years old. the mean age was 59+/ le it was 61.3 +/14.4 years in ovc. male predominance was found with 60% of scc group and 75% of vc group. no statistically significant differences in age and sex distribution were observed between the 2 studied in scc was the tongue 26.7% (8 cases) while buccal mucosa and alveolar ridge 33.3% (4 cases for each) were the common sites in ovc. histopathological examination showed that 14 cases (46.7%) were well differentiated scc, 12 cases (40%) moderately tiated and 4 cases (13.3%) were poorly moesinimmunoreactivity was recognized in all the studied groups with predominant cytoplasmic expression in scc and membranous expression in vol. 28(2), june 53 ior and invasiveness; comparing these biological parameters in oscc compare the immunohistochemical expression of ck14, moesin and mmp7 in oral squamous cell and to with the fixed, paraffin – embedded tissue blocks (30 oscc and 12 ovc) were collected from labrotaries archives and after histopathological haematoxylin& eosin stained micrometer thick sections were cut and mounted on positively charged slides and stained immunohistochemically with monoclonal using anti moesin, anti ck14 and anti (abcam uk). abcam expose mouse and rabbit hrp/dab (catalog no. the age of the studied samples ranged 99 years old. the mean age was 59+/14.4 years in ovc. male predominance was found with 60% of scc group and 75% of vc group. no statistically significant differences in age and sex distribution were observed between the 2 studied in scc was the tongue 26.7% (8 cases) while buccal mucosa and alveolar ridge 33.3% (4 cases for each) were the common sites in ovc. histopathological examination showed that 14 cases (46.7%) were well differentiated scc, 12 cases (40%) moderately tiated and 4 cases (13.3%) were poorly moesinimmunoreactivity was recognized in all the studied groups with predominant cytoplasmic expression in scc and membranous expression in groups and between different grades of scc. cytokeratin 14 positivity was noticed in all studied groups with significant scc and ovc p=0.012 and there was a significant difference between the different grade of oscc (p= june 2016 figure1: cytoplasmic expression in scc, b: membranous &cytoplasmic in vc no difference was noticed between 2 studied groups and between different grades of scc. cytokeratin 14 positivity was noticed in all studied groups with significant scc and ovc p=0.012 and there was a significant difference between the different grade of oscc (p=0.047) (figure2). figure2: cytoplasmic expression in scc,b: cytoplasmic expression invc a b a b figure1:moesinimmunostainig,a: cytoplasmic expression in scc, b: membranous &cytoplasmic in vc no difference was noticed between 2 studied groups and between different grades of scc. cytokeratin 14 positivity was noticed in all studied groups with significant scc and ovc p=0.012 and there was a significant difference between the different grade 0.047) (figure2). ck14 immunostaining, a: cytoplasmic expression in scc,b: cytoplasmic expression invc a comparative study moesinimmunostainig,a: cytoplasmic expression in scc, b: membranous &cytoplasmic in vc no difference was noticed between 2 studied groups and between different grades of scc. cytokeratin 14 positivity was noticed in all studied groups with significant difference between scc and ovc p=0.012 and there was a significant difference between the different grade 0.047) (figure2). ck14 immunostaining, a: cytoplasmic expression in scc,b: cytoplasmic expression invc omparative study moesinimmunostainig,a: cytoplasmic expression in scc, b: membranous &cytoplasmic in vc no difference was noticed between 2 studied groups and between different grades of scc. cytokeratin 14 positivity was noticed in all difference between scc and ovc p=0.012 and there was a significant difference between the different grade ck14 immunostaining, a: cytoplasmic expression in scc,b: cytoplasmic expression invc omparative study j bagh college dentistry vol. 28(2), june 2016 a comparative study oral diagnosis 54 collectively, mmp7 expression was observed in the all studied groups with predominant cytoplasmic pattern in scc and nuclear pattern in ovc(figure3). figure 3:mmp7 immunostaining, a:cytolasmic expression in scc,b: nuclear expression in vc no difference was found between the 2studied groups and between the different grades of scc. a strong positive linear correlation between mmp7and ck14 was noticed (tables 4 and 5) discussion assessment of moesinimmunohistochemical expression: all the studied cases showed positive expression for moesin, interestingly, moesin cytoplasmic expression was detected in 86.7% of scc group which is higher than that of vc group (66.7%), while vc showed membranous expression(16.7%) compared to scc group (3.3%). this would corroborate the finding of (12), however in this studied series the difference in this protein expression failed to reach the level of statistical significance which may be attributed to the small sample size. there are several explanations for the shift in localization: firstly, conformational and functional changes of moesin results in redistribution of this molecule in tumor cells (13). secondly, cd44(a cell surface receptor) has been cleaved by mmp-1 in carcinoma cells at a membrane proximal domain, thereby suggesting that functional moesin migrates with cd44 degraded from the cell surface to the cytoplasm (14). thirdly, according to carcinogenesis, it is possible that increased membranous degredation in more aggressive neoplasms and mutation of moesin gene cannot cross-link between plasma membrane and actin filament (15). the last reason may explain the present work results regarding the grades in which proportional decrease in the moesin score with increasing histopathologic grade was observed, however no statistical significance in median moesin score was noticed between the different grades of scc. assessment of cytokeratin 14 immunohistochemical expression: the results showed that scc cases showed ck14 immunostaining in all the neoplastic cells, irrespective of the grade. these findings are in contrast to those ofsu et al.(16). whilechu et al. (17)found that over 90% of cases of scc of various origins were ck14 positive. in previous studies performed by morgan and lane(18), ck 14 expression was detected regardless of the differentiation compartment. in the current study, all oral epithelial layers in vc exhibited strong immunostaining for ck 14 and that in accordance witholiveira et al.(10). the difference was significant regarding the ck 14 profile between oscc and ovc, p=0.012,which emphasized the biological behavior of the studied lesions, especially pattern of ovc as the cks profile was similar to the cks profile in well differentiated oral squamous cell carcinoma. on the other hand there was significance among the different grades of oscc(p=0.047). moreover, it confirms the use of this protein as a marker of cellular differentiation. assessment of mmp7 immunohistochemical expression: in the present work, all the studied cases showed positive reaction to mmp7. in vc, nuclear immunostaining was the main staining pattern of the cells, which also reported in other studies (19). the explanation of nuclear expression is based on findings of a recent study carried out by (20) which focused on epithelial cell adhesion molecule (epcam, a single-transmembrane protein), mmp7 is a target of epcam, which is induced at the transcriptional level upon nuclear translocation of epicd. expression patterns and levels of epcam and mmp7 correlated closely in vivo in tumors suggesting that there is biological relevance of this association during malignancy (20).while the absence of mmp-7 from epithelial cells of ovc was found in a study conducted byimpola et al.(21), who consideredthat matrilysin expression a b j bagh college dentistry vol. 28(2), june 2016 a comparative study oral diagnosis 55 correlates with the aggressive phenotype of many cancers. while the cytoplasmic stain was the predominant one in the scc; this is accordance withweber et al.(22), who found that cytoplasmic mmp-7 is mainly produced by tumor cells themselves and is associated with short survival times in head and neck cancer(23), also demonstrated that mmp-7cytoplasmic expression is significantly correlated with lymph node metastasis in oral cavity cancers. as oscc &ovc are carcinoma,both of them have the ability to induce angiogenesis and local invasion of the basement membrane so,both of them expressed mmp7 positive immunoreactions, no difference was observed between both tumors and among the 3 grades of scc concerning the degree of expression. as conclusion; in this project moesin and ck14 are present normally in squamous cells. they changed their cellular localization and expression pattern in neoplastic epithelia. as vc is a very well differentiated variant of scc, it has specific pattern for moesin, ck14 and mmp7 that differed from scc, however, the current work not reach the level of significance in moesin and mmp7. ck14 immunoreactivity indicated a significant difference in the degree of cellular differentiation between oscc &ovc. table 1: the difference in age and sex between (scc) group and vc group variables scc verrucous p n % n % age group (years) 0.67 [ns] <50 9 30.0 2 16.7 50-69 13 43.3 6 50.0 70+ 8 26.7 4 33.3 total 30 100.0 12 100.0 range (24-99) (32-83) mean 59 61.3 sd 15.3 14.4 sex 0.36 [ns] female 12 40.0 3 25.0 male 18 60.0 9 75.0 total 30 100.0 12 100.0 table 2: frequency distribution of scc group by grading grading for scc n % well differentiated 14 46.7 moderately differentiated 12 40.0 poorly differentiated 4 13.3 total 30 100 table 3: the difference in type of moesin tissue stain expression between scc and vc groups moesin tissue stain expression verrucous ca (vs squamous cell ca) p scc verrucous n % n % mainly cytoplasmic 26 86.7 8 66.7 0.24 ns mainly membranous 1 3.3 2 16.7 mainly mixed 3 10.0 2 16.7 total 30 100.0 12 100.0 table 4: the difference in median score of the 3 markers staining between scc and vc groups. verrucous ca (vs squamous cell ca) scc verrucous n % n % p moesin score 0.18[ns] score-i 0 0.0 0 0.0 score-ii 9 30.0 7 58.3 score-iii 15 50.0 3 25.0 score-iv 6 20.0 2 16.7 j bagh college dentistry vol. 28(2), june 2016 a comparative study oral diagnosis 56 total 30 100.0 12 100.0 median score-iii score-ii mean rank 23 17.8 mmp7-score 0.09[ns] score-i 1 3.3 0 0.0 score-ii 15 50.0 3 25.0 score-iii 14 46.7 9 75.0 score-iv 0 0.0 0 0.0 total 30 100.0 12 100.0 median score-ii score-iii mean rank 19.8 25.9 cytokeratin score 0.012 score-i 1 3.3 0 0.0 score-ii 17 56.7 2 16.7 score-iii 12 40.0 10 83.3 score-iv 0 0.0 0 0.0 total 30 100.0 12 100.0 median score-ii score-iii mean rank 18.9 28.1 table 5: the difference in average score of 3 types of markers staining between the three grades of scc grading well differentiated moderately differentiated poorly differentiated n % n % n % p moesin score 0.12[ns] score-i 0 0.0 0 0.0 0 0.0 score-ii 3 21.4 3 25.0 3 75.0 score-iii 7 50.0 7 58.3 1 25.0 score-iv 4 28.6 2 16.7 0 0.0 total 14 100.0 12 100.0 4 100.0 median score-iii score-iii score-ii mean rank 17.4 15.8 8 r=-0.314 p=0.09[ns] mmp7-score 0.18[ns] score-i 0 0.0 0 0.0 1 25.0 score-ii 10 71.4 4 33.3 1 25.0 score-iii 4 28.6 8 66.7 2 50.0 score-iv 0 0.0 0 0.0 0 0.0 total 14 100.0 12 100.0 4 100.0 median score-ii score-iii score-iii mean rank 13.1 18.7 14.3 r=0.216 p=0.25[ns] cytokeratin score 0.047 score-i 0 0.0 0 0.0 1 25.0 score-ii 4 28.5 8 66.7 2 50.0 score-iii 10 71.5 4 33.3 1 25.0 score-iv 0 0.0 0 0.0 0 0.0 total 14 100.0 12 100.0 4 100.0 median score-iii score-ii score-ii mean rank 19.7 13.1 11.4 r=0.17 p=0.37[ns] j bagh college dentistry vol. 28(2), june 2016 a comparative study oral diagnosis 57 references 1. spíndula-filho s, aparecido d, elismauro fm. oral squamous cell carcinoma versus oral verrucous carcinoma: an approach to cellular proliferation and negative relation to human papillomavirus (hpv). tumor biol 2011; 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93: 341–53 . 21. impola u, uitto vj, hietanen j. et al. differential expression of matrilysin-1 (mmp-7), 92 kdgelatinase (mmp-9), and metalloelastase (mmp-12) in oral verrucous and squamous cell cancer. j pathol 2004;202: 14–22 22. weber a, hengge ur, stricker i. et al. protein microarrays for the detection of biomarkers in head and neck squamous cell carcinomas. hum pathol 2007;38: 228–38 23. de vicente jc, lequerica-fernandez p, santamarı j. expression of mmp-7 and mt1-mmp in oral squamous cell carcinoma as predictive indicator for tumor invasion and prognosis. j oral pathol med 2007; 36: 415–24. j bagh college dentistry vol. 29(2), june 2017 discoloration of pedodontics, orthodontics and preventive dentistry 97 discoloration of stretched clear elastomeric chains by dietary media (an in vitro study) athraa a. abass b.d.s, m.sc. (1) akram f. alhuwaizi b.d.s., m.sc., ph.d. (2) abstract: background: with the increasing demand on esthetic orthodontic appliances, discoloration of clear elastomeric chains and modules remains an issue which concerns both orthodontics and patients. this in vitro study was conducted to evaluate the effect of exposing stretched clear elastomeric chains from six different companies (ortho technology, ormco, ortho organizer, american orthodontics, opal and g&h companies) to three types of dietary media (tea, coffee and turmeric). materials and methods: a total of 960 lengths of six modules were cut from short type elastomeric chain; 160 pieces from each brand. the specimens were stretched 50%, placed on plastic boards, and incubated in water at 37°c for 1 day, 7 days, 14 days and 28 days. once a day, the specimens were immersed for ten minutes in the testing dietary media, washed and then returned back to the water container. color measurements were made before and after incubation of the specimens. digital image were taken by an slr digital camera and the color changes were calculated according to cie l*a*b* color space system by adobe photoshop program. the resulting data were statistically analyzed using anova and lsd tests. result: elastomeric chains from ao, opal and g&h companies were the most brands prone to discoloration. ortho organizers and ortho technology chains were the least prone to discoloration. tea, coffee and turmeric solutions discolored elastomeric chains from all companies in a variable degree, however turmeric caused significantly more discoloration, followed by tea and least by coffee. the amount of discoloration caused by tea and coffee increases gradually to peak at 28 days, while most of the discoloration caused by turmeric was in the first day and reached a plateau in a week. conclusion: to decrease the discoloration of clear elastomeric chains the consumption of colored dietary media especially spices like turmeric are to be discouraged. key words: clear elastomeric chains, discoloration, and dietary media. . (j bagh coll dentistry 2017; 29(2):97-103 introduction orthodontic patients, including a growing population of adults, not only want an improved smile, but they are also increasingly demanding better aesthetics during treatment. the development of appliances that combine both acceptable aesthetics for the patient and adequate technical performance for the clinician is the ultimate goal. this problem was partially solved by the introduction of aesthetic transparent brackets made of ceramic or composite (1). however, while most of these brackets were resistant to stain, clear elastomeric chains used to retract teeth or to close spaces discolored if patients ate certain dietary media like coffee, tea and turmeric (2). it is difficult to measure the colour of elastomerics using a spectrophotometer or a colorimeter because of their small size and curved geometry. recent advances in digital cameras and imaging software encouraged their use in colour measurement for clinical dentistry. moreover, a statistically significant correlation was found between a digital camera with an appropriate calibration protocol and a spectrophotometer (3). there is some concern regarding the quality of elastomers and which company is superior to (1) orthodontist, karbala specialized dental center, ministry of health. (2) professor. department of orthodontics. college of dentistry, university of baghdad. the others in efficacy or cost-effectiveness. many studies have been carried out on the force decay of elastomeric chains (4,5). however, the literature is very scares on studies on their color stability. materials and methods six brands of clear orthodontic elastomeric chains were investigated (ortho technology, ormco, ortho organizer, ao, opal and g&h). from each brand 160 pieces of 6 modules were cut. these had initial lengths of 16-19mm which when stretched 50% become 24-27.5mm long. this distance approximated the distance between the hook of the lateral bracket and the hook of the first molar tooth for en-masse retraction of the anterior teeth. a total of 960 elastomeric chain specimens were tested, 240 for each dietary medium (distilled water, tea, coffee and turmeric) where distilled water served as a positive control. holding blocks were made by inserting 24 stainless steel pins perpendicularly into a plastic board making 12 pairs set at a distance of 50% more than the original length of the elastomeric chains (fig. 1). all the test specimens were placed on the holding blocks and incubated in water containers for 1, 7, 14 or 28 days at 37°c. once each day, all the plastic holding blocks with their elastomeric j bagh college dentistry vol. 29(2), june 2017 discoloration of pedodontics, orthodontics and preventive dentistry 98 specimens were removed from water containers and immersed for ten minutes in the testing dietary media containers. after that, the holding blocks were removed from the dietary media containers and rinsed with copious amount of water to wash out any remnants of the dietary solutions and returned back and incubated in the water containers until the next day (6). figure 1: plastic holding block. color measurements were made before and after immersion. a commercial slr camera, nikon d40 (nikon corp., japan) with tamron sp af 18-55mm with 1:1 macro lens (saitama, japan) were used. the digital camera was set to manual mode, which allowed total control of the shutter speed and aperture size. the shutter speed was set at 1/5 seconds with an aperture of f32, and the film sensitivity was set at international organization for standardization 200 sensitivity mode (7). digital images were taken in a darkroom with a ring fluorescent tube (opple/ 40w, 6500k) as a light source. the fluorescent tube was perpendicularly fixed at a distance of 45cm from the platform where the elastomeric chains were placed. a standard grey card (dgk color tools) was used because neutral light grey was considered to be the ideal background for shade matching which had 17.68 % reflectance (7). the digital image files were opened in adobe photoshop program (version 7.0; adobe systems inc., san jose, california, usa). four areas (average 5 × 5 pixels) were randomly selected using the ‘eyedropper’ tool. the cie l*, a*, and b* values of each area were obtained using the ‘lab sliders’ in the software. l* is in the range of 0-100 and a* and b* in the range of -120 to 120. the l*, a*, and b* values were calculated by averaging the four areas of each specimen. the threedimensional cie lab color order system provided a useful standardization technique for color difference assessments. the system included three color co-ordinates. cie l* corresponded to the value (degree of lightness) in the munsell system, and a* and b* co-ordinates designate the positions on the red/green and yellow/blue axes, respectively (+a= red, -a= green; +b= yellow, -b= blue). color difference ∆e*= ∆l*2 +∆a*2+∆b*2 2 (8). statistical analysis data was collected and analyzed by using statistical package of social science program (spss, chicago, illinois, usa). mean and standard deviation (sd) values were computed. one-way analysis of variance (anova) and least significant difference (lsd) tests were used to test the differences between brands and the effect of different dietary media. p values of less than 0.05 were regarded as statistically significant. results color changes (∆e* ab) after immersion in the dietary media are displayed in table 1. difference between brands: the difference of ∆e*values of elastomeric chains between different companies was minimal for the specimens immersed in water but was more evident for those immersed in tea, coffee and turmeric solutions (fig. 2). all the readings were comparable for all brands immersed in water. however, at 14 days anova test showed a significant difference and lsd test showed that ao chains had a significant less ∆e*values than ormco, ortho organizers and opal chains (table 2). the highest color change caused by tea was for opal (δe*=40.6), followed by ao (δe*=39.4), g&h (δe*=39.1), ormco (δe*=38.9), ortho technology (δe*=35.1) and least was for ortho organizers (δe*=30.9). however, at 7, 14 and 28 days anova test showed significant differences and lsd test showed significant differences between all brands (table 2). the highest color change caused by coffee was for ormco (δe*=27.2), followed by g&h (δe*=26.3), ortho technology (δe*=24.8), opal (δe*=23.8), ao (δe*=23.5), and least was for ortho organizers (δe*=22.2). however, at 1, 7 and 14 days anova test showed significant differences and lsd test showed significant differences between all brands (table 2). the highest color change for the turmeric solution was for ao (δe*=57.5), followed by g&h (δe*=56.4), opal (δe*=55.9), ortho organizers (δe*=53.4), ormco (δe*=53.2), and least was for ortho technology (δe*=52.1). however, at all time intervals anova test showed significant differences and lsd test showed significant differences between all brands (table 2). j bagh college dentistry vol. 29(2), june 2017 discoloration of pedodontics, orthodontics and preventive dentistry 99 difference between dietary media for all brands, chains immersed in turmeric showed highest color change peaking at 28 days followed by tea then coffee and lastly water which showed only minimal color change (fig. 3). for all brands, anova test showed significant differences for all media and all time intervals (table 3). lsd test for the specimens immersed in water showed significant differences from those immersed in tea or coffee for 7 to 28 days but not for 1-day. but for those immersed in turmeric solution the difference was significant from day 1 to 28 days. lsd test for the specimens immersed in tea showed significant differences from those immersed in coffee for all brands and at all time intervals except at 1-day. lsd test for the specimens immersed in turmeric solution showed significant differences from those immersed in tea or coffee for all brands and at all time intervals. discussion the color change values were recorded for test periods of 1, 7, 14 and 28 days in order to measure the relative changes occurring throughout the whole time period between visits. a digital camera was used to assess the amount of color change because of its reliability and accuracy. jarad et al. (3) used a 5-megapixel camera and found a highly significant correlation between a spectrophotometer and digital camera for all cie l*a*and b* coordinates (9). the cie l*a* and b* color space was used for assessment of color changes. this system was commonly used for assessment of small color differences (10). the discoloring effect of tea and coffee on elastomeric modules had been extensively researched, but turmeric was added to this investigation because of its widespread use in cooking. recent researches had evaluated the discoloration caused by turmeric on esthetic brackets and elastomeric modules (11-14). difference between brands from the result of this study, no clear pattern was found regarding the susceptibility of a particular brand of elastomeric chain to discoloration but these general points could be noted: • elastomeric chains from ao, opal and g&h companies were the most discolored brands. • elastomeric chains from ortho organizers and ortho technology companies were the least discolored brands. these differences might be because of several factors like the chemical composition and details of manufacturing and processing. the polyurethane used to make the elastomeric chains was made by several chemical reactions involving many compounds making products with different chemical compositions which affected the configuration of the chains of the elastomer and their ability to withstand deterioration from external agents and processing conditions (15). the surface characteristics such as texture and porosity could be different (12). to the authors’ knowledge, there is no published report on the discoloration of elastomeric chains, therefore the comparison with other researches is not possible. however, previous researches on the discoloration of elastomeric modules also show a diversity in the intensity of discoloration caused by different media on the different brands of modules (4,12,14,16-18). difference between dietary media in the present study, turmeric caused significantly more discoloration than tea and coffee. this agrees with previous studies (13) but disagrees with the findings of other studies (15) who found more discoloration of elastomeric modules caused by coffee than turmeric. the difference with bhandari et al. (14) may be because of the different response of modules than chains and the variable company brands. in the present study, tea caused significantly more discoloration than coffee. however, this disagrees with the findings of other studies carried out on elastomeric modules (12,14,16). the difference may be because of the different chemical composition and manufacturing technique between elastomeric chains and modules. comparison between immersion times since all elastomeric brands tested underwent color change in all solutions over time, the storage period was taken to assess the degree of staining. it was seen that the storage time influenced the amount of color change of the elastomeric chains and this was agreement with kim and lee (8) and bhandari et al. (14). exposure to water led to chemical degradation of polyester polyurethane. substances leached from the polymer over time so that pigments and other compounds from dietary media could penetrate deep into elastomeric chains and cause discoloration (19,20). thus when the elastomeric chains were stretched, the stretching affected the color stability of elastomeric chains giving a significant difference between the readings of 1 day, 7 days, 14 days and 28 days after immersion in dietary media for all groups. this was in agreement with j bagh college dentistry vol. 29(2), june 2017 discoloration of pedodontics, orthodontics and preventive dentistry 100 bhandari et al. (14) who found the amount of discoloration increased as the amount of immersion time increased. the amount of discoloration caused by tea and coffee increased gradually to peak at 28 days. this agrees with the findings of bhandari et al. (14) who found similar findings on elastomeric modules. this disagree with the findings of lew (21) who found the amount of discoloration of elastomeric modules increased rapidly. most of the discoloration caused by turmeric was in the first day. after this period, there was trend towards saturation and reached a plateau at 7 days. this agrees with the findings of bhandari et al. (14) who found the same outcome on elastomeric modules. limitations of the study: reader should be cautious when interpreting this data to the clinical condition. in vivo staining differs from that found in vitro because of the lack of bacteria, abrasion from occlusion, eating and brushing, salivary mucins and proteins and the dilution effect of saliva on the ingested dietary media. furthermore, the technique to assess color change needs further development because of the small surface area, clear color, and geometry of the elastomeric chains. clinical consideration: 1. the orthodontic patient should be advised to minimize the consumption of coloring foods like turmeric, tea and coffee to keep the esthetic appliance clear with minimum amount of discoloration to get benefit from choosing this type of appliance. 2. the orthodontist should use the clear elastomeric chains with the best color stability to minimize their discoloration to satisfy the patient. conclusion 1. elastomeric chains from ao, opal and g&h companies were the most brands prone to discoloration, while elastomeric chains from ortho organizers and ortho technology companies were the least ones. 2. tea, coffee and turmeric solutions discolored elastomeric chains from all companies in a variable degree, however turmeric caused significantly more discoloration, followed b y tea and least by coffee. the amount of discoloration caused by tea and coffee increased gradually to peak at 28 days, while most of the discoloration caused by turmeric was in the first day and reaches a plateau at 7 days. table 1: mean and standard deviation of the color changes (∆ e* ab) of all brands after immersion in the dietary media. 1 day 7 days 14 days 28 days mean sd mean sd mean sd mean sd w at er ortho technology 6.578 4.376 6.849 3.375 6.649 1.706 6.887 1.943 ormco 5.492 2.044 4.815 1.714 4.884 3.129 6.202 1.867 ortho organizers 8.508 4.215 6.932 2.8 6.202 2.531 7.717 3.851 ao 8.011 2.689 8.414 3.86 8.873 3.246 7.856 3.99 opal 7.543 1.92 5.12 2.375 5.348 2.244 6.631 2.01 g&h 8.189 5.076 7.679 3.204 7.375 3.82 7.437 4.021 t ea ortho technology 9.515 3.534 17.097 2.126 24.933 3.027 35.088 4.685 ormco 7.539 2.467 17.097 1.074 29.462 1.578 38.9 2.028 ortho organizers 9.781 3.271 14.963 2.699 27.625 4.182 30.876 4.657 ao 9.944 2.773 20.932 4.844 25.627 5.73 39.428 4.458 opal 8.265 3.189 16.208 3.434 20.247 4.361 40.56 2.716 g&h 11.616 5.637 23.61 3.744 29.782 5.3 39.081 6.05 c of fe e ortho technology 9.116 3.385 12.637 2.622 14.95 2.252 24.79 5.194 ormco 11.469 1.582 12.795 2.731 17.463 1.294 27.232 2.305 ortho organizers 12.015 3.474 12.732 2.359 13.495 2.637 22.191 3.275 ao 11.838 4.823 14.94 3.429 15.714 1.596 23.533 3.392 opal 14.575 1.753 13.481 2.825 14.312 1.681 23.831 3.487 g&h 13.575 3.403 17.368 2.389 18.67 6.666 26.294 4.625 t ur m er ic ortho technology 25.756 3.478 41.511 4.392 49.911 2.235 52.116 3.632 ormco 23.959 1.423 43.675 1.771 52.987 1.942 53.233 2.362 ortho organizers 26.483 4.867 41.298 5.782 50.001 4.653 53.392 2.072 ao 28.706 4.267 53.34 3.725 57.023 6.141 57.531 4.735 opal 23.928 2.088 44.607 2.186 51.33 5.449 55.898 2.415 g&h 26.27 2.537 46.753 3.053 50.715 4.279 56.388 4.705 j bagh college dentistry vol. 29(2), june 2017 discoloration of pedodontics, orthodontics and preventive dentistry 101 figure 2: color changes of elastomeric chains (ortho technology, ormco, ortho organizer, ao, opal and g&h) after immersion in water, tea, coffee, and turmeric. table 2: difference between the color changes of the elastomeric chains of different companies. days anova lsd test a a a a a b b b b c c c d d e b c d e f c d e f d e f e f f w at er 1 ns 7 ns 14 * ns ns ns ns ns ns ** ns ns * ns ns ** ns ns 28 ns t ea 1 ns 7 *** ns ns * ns *** ns * ns *** *** ns *** ** ns *** 14 *** * ns ns * * ns ns *** ns ns *** ns ** * *** 28 *** ns * * ** * *** ns ns ns *** *** *** ns ns ns c of fe e 1 * ns ns ns *** ** ns ns * ns ns ns ns ns ns ns 7 *** ns ns ** ns *** ns ** ns ** ** ns ** * ns ** 14 ** ns ns ns ns * * * * ns ns ns ** ns ** ** 28 ns t ur m er ic 1 * ns ns ns ns ns ns ** ns ns ns ns ns ** ns ns 7 *** ns ns *** ns ** ns *** ns ns *** ns ** *** *** ns 14 ** ns ns ** ns ns ns * ns ns ** ns ns ** ** ns 28 ** ns ns ** * ** ns ** ns ns * ns ns ns ns ns a. ortho technology, b. ormco, c. ortho organizers, d. ao, e. opal, f. g&h ns= non-significant, * = p<0.05, ** = p<0.01, *** = p<0.001 j bagh college dentistry vol. 29(2), june 2017 discoloration of pedodontics, orthodontics and preventive dentistry 102 figure 3: mean color change of clear elastomeric chains from ortho technology, ormco, ortho organizer, ao, opal and g&h companies after immersion in water, tea, coffee, and turmeric. table 3: statistical difference between the color changes of the clear elastomeric chains immersed in different dietary media. days anova lsd test water water water tea tea coffee tea coffee turmeric coffee turmeric turmeric ortho technology 1 *** ns ns *** ns *** *** 7 *** *** *** *** ** *** *** 14 *** *** *** *** *** *** *** 28 *** *** *** *** *** *** *** ormco 1 *** * *** *** *** *** *** 7 *** *** *** *** *** *** *** 14 *** *** *** *** *** *** *** 28 *** *** *** *** *** *** *** ortho organizers 1 *** ns ns *** ns *** *** 7 *** *** ** *** ns *** *** 14 *** *** *** *** *** *** *** 28 *** *** *** *** *** *** *** ao 1 *** ns * *** ns *** *** 7 *** *** *** *** * *** *** 14 *** *** * *** *** *** *** 28 *** *** *** *** *** *** *** opal 1 *** ns *** *** *** *** *** 7 *** *** *** *** * *** *** 14 *** *** *** *** ** *** *** 28 *** *** *** *** *** *** *** g&h 1 *** ns ** *** ns *** *** 7 *** *** *** *** *** *** *** 14 *** *** *** *** *** *** *** 28 *** *** *** *** *** *** *** ns= non-significant, * = p<0.05, ** = p<0.01, *** = p<0.001 j bagh college dentistry vol. 29(2), june 2017 discoloration of pedodontics, orthodontics and preventive dentistry 103 references 1. russell js. aesthetic orthodontic brackets. j orthod 2005;32(2):146-63. 2. lew kk. staining of clear elastomeric modules from certain foods. j clin orthod 1990; 24: 4724. 3. jarad fd, moss bw, russell md. the use of digital camera for color matching and communication in restorative dentistry. brit dent j 2005; 199: 43-9. 4. de genova dc, mcinnes-ledoux p, weinberg r, shaye r. force degradation of orthodontic elastomeric chains—a product comparison study. am j orthod dentofacial orthop 1985; 87: 377– 84. 5. baty dl, storie dj, von fraunhofer ja. synthetic elastomeric chains. a literature review. am j orthod dentofacial orthop 1994; 105: 536–42. 6. alhuwaizi af, yousif haa. the effect of food simulants on the bond strength of orthodontic adhesive (an in vitro study). iraqi orthod j 2008; 4(1): 1-7. 7. wee ag, johnston wm, lindsey dt, kuo s, the color accuracy of c digital cameras for using in dentistry. dent mat 2006; 22: 553-9. 8. kim sh, lee yk. the measurement of discoloration of orthodontic elastomeric chains with a digital camera. eur j orthod 2009; 31(5): 556-62. 9. commission internationale de l’eclairage (cie) colorimetry. technical report, 2004. 10. da silva dl, mattos ct, de araújo mv, de oliveira ruellas ac. color stability and fluorescence of different orthodontic esthetic arch wires. angle orthod 2013; 83: 127-32. 11. wriedt s, schepke u, wehrbein h. the discoloring effects of food on the color stability of esthetic brackets – an in vitro study. j orofac orthop 2007; 68(4):308-20. 12. ardeshna ap, vaidyanathan tk. color changes of orthodontic elastomeric module materials exposed to in vitro dietary media. j orthod 2009; 36(3):177-185. 13. akyalcin s, rykiss j, rody wj, wiltshire wa. digital analysis of staining properties of clear esthetic brackets. j orthod 2012; 39(3); 170-5. 14. bhandari v, singla a, mahajan v, jaj hs, saini ss. reliability of digital camera over spectrophotometer in measuring the optical properties of orthodontic elastomeric ligatures. j indian orthod soc 2014; 48(4): 239-44. 15. brantley wa, eliades t. orthodontic materials: scientific and clinical aspects. stuttgard. thieme. 2001; 91-9. 16. ferrnandes abn, ribeiro aa, araujo mva, ruellas aco. influence of exogenous pigmentation on the optical properties of orthodontic elastomeric ligatures. j appl oral sci. 2012; 20(4): 4626. 17. silva avm, mattos gv, kato cm, normando d. in vivo color changes of esthetic orthodontic ligatures. dental press orthod, 2012. 17(5):76-80. 18. cavalcante js, barbosa mc, sobral mc. evaluation of the susceptibility to pigmentation of orthodontic esthetic elastomeric ligatures. dental press j orthod 2013; 18(2): 20.e1-8. 19. huget ef, patrick ks, nunez lj. observation on the elastic behavior of a synthetic orthodontic elastomer. j dent res. 1990; 496501. 20. macedo eod, collares fm, leitune vcb, samuel smw, fortes cbb. pigment effect on the long-term elasticity of elastomeric ligatures. dent press j orthod. 2012; 17(3):27. 21. lew kk. staining of clear elastomeric modules from certain foods. j clin orthod. 1990; 24(8):472-4. taghreed f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of serum oral diagnosis 83 assessment of serum and salivary oxidant and total antioxidant status of patients with recurrent aphthous stomatitis in a sample of basrah city hussein sh. al-essa, b.d.s. (1) taghreed f. zaidan, b.d.s., m.sc., ph.d. (2) abstract background: recurrent aphthous stomatitis (ras) is the most common painful oral mucosal disease, affecting approximately 20% of the population. ras presents with a wide spectrum of severity ranging from a minor nuisance to complete debility. many of factors thought to have been involved in its etiology; that might have at the same time a direct or indirect impact upon oxidant/antioxidant system and trigger free radicals production. the aim of this study was to determine the possible association of oxidant/total antioxidant status and recurrent aphthous stomatitis (ras). subjects, materials and methods: the study consisted of thirty patients with recurrent aphthous stomatitis and thirty healthy controls from which saliva and blood samples were collected. malondialdehyde as an oxidative stress biomarker and total antioxidant status were measured in serum and saliva. results: malondialdehyde in serum and saliva was significantly higher in recurrent aphthous stomatitis patients in comparison to healthy controls (p<0.05). no significant differences were found in total antioxidant status between recurrent aphthous stomatitis patients and control subjects (p>0.05). conclusions: the changes in the oxidative stress in biological systems can be induced by the consumption of antioxidants and/or by an overload of oxidant species, so the antioxidant defense system become deficient that may be important in the inflammatory reactions observed in recurrent aphthous stomatitis. keywords: recurrent aphthous stomatitis, oxidative stress, antioxidants, malondialdehyde, total antioxidant status. (j bagh coll dentistry 2013; 25(special issue 1):83-88). الخالصة وتمثل األلتھابات الفمویة القالعیة . من سكان العالم) %20(یصیب أكثر من من اكثر أمراض أنسجة الفم المؤلمھ شیوعا حیث) ras(یعتبر ألتھاب الفم القالعي المتكرر:المقدمة .المتكررة مدیات واسعة من الشدة تتراوح من االنزعاج البسیط الى الوھن الكامل بین المصابین ) oxidative stress(شر على الشد التأكسدي لك العدید من العوامل التي یعتقد أنھا من مسببات ألتھاب الفم القالعي المتكرر والتي یكون لھا في نفس الوقت تأثیر مباشر أو غیر مباھنا .الضارة للخالیا الحیة) free radicals(وبالتالي أنتاج الجذور الحرة antioxidants)(و نظام مضادات العوامل المؤكسدة الدفاعیة من جھة وأصابات ألتھاب الفم القالعي antioxidants)(ومضادات األكسدة ) oxidative stress(الدراسة صممت لتحدید العالقة الممكنة بین الشد التأكسدي : الھدف من الدراسة .المتكرر من جھة اخرى وكانت المجموعتان متماثلتین بالجنس والعمر . ن مریضا بألتھاب الفم القالعي المتكرر وثالثون شخصا طبیعیا للمقارنھ بینھماالدراسة شملت ثالثو: االشخاص والمواد وطریقة العمل malondialdehyde) (mda وبعدھا تم حساب ) 20ºc-(اخذت العینات من مصل ولعاب المجموعتین وخضعت للطرد المركزي وخزنت عند . سنة) 55-14(الذي یتراوح بین .لكال المجموعتین) tas )total antioxidant statusو ال توجد أختالفات ھامة في مؤشر ). p<0.05(كمؤشر للشد التأكسدي مقارنة باألصحاء ) mda(أظھرت النتائج أن في األلتھابات الفمویة القالعیة المتكررة أرتفاع ملحوظ في :النتائج )tas .( أو حمل زائد من العوامل antioxidants) (في األنظمة الحیویة ناجم عن أستھالك مضادات األكسدة الدفاعیة ) oxidative stress(تأكسدي أن التغیرات في الشد أل: األستنتاجات .القالعي المتكرر اب الفمالمؤكسدة وبالتالي عدم كفاءة النظام الدفاعي لمضادات العوامل المؤكسدة ومن ھذا نستنتج الدور الفاعل للشد التأكسدي كمسبب لمرض ألتھ .الفمویة القالعیة المتكررة كذلك یمكن أستخدام اللعاب كسائل حیوي تشخیصي مؤثر ومالئم لقیاس مؤشرات الشد التأكسدي ومضادات األكسدة للمرضى المصابین باأللتھابات introduction recurrent aphthous stomatitis (ras) is a common condition in which recurring ovoid or round ulcers affect the oral mucosa. it is one of the most painful oral mucosal inflammatory ulcerative conditions and can cause pain on eating, swallowing and speaking (1). aphthous ulcers are classified into three different types, minor, major and herpetiform, figure-1. minor aphthae are generally located on labial or buccal mucosa, the soft palate and the floor of the mouth (nonkeratinized mucosa), they can be singular or multiple and tend to be small (less than 1 cm in diameter) and shallow, this type of ras is the most common (80% of cases), and usually heals within 7-14 days (2). (1) m.sc. student, department of oral diagnosis, college of dentistry, baghdad university. (2) professor, department of oral diagnosis, college of dentistry, baghdad university. major aphthae is typically larger and deeper in ulceration and heals slowly over weeks, or even months. it has also been shown that major aphthae are more likely to scar with healing. herpetiform aphthae are frequently more numerous and vesicular in morphology and usually heals within about 1 month (2). different subgroups of patients appear to have different causes for occurrence of aphthae. these factors suggest a disease process that is triggered by a variety of causative agents (such as trauma, stress, genetic, hypersensitivity, nutrition, immune disturbance and hormonal imbalance) (3). when all the subgroups are combined, the various causation clusters into three categories: primary immune dysregulation, decrease of the mucosal barrier and increase in an antigenic exposure (3,4). j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of serum oral diagnosis 84 all of the above mentioned conditions can disturb the oxidant/antioxidant balance of organism and can accelerate the formation of free radicals. oxidative stress occurs when the intracellular concentrations of reactive oxygen species (ros) increase over the physiological values (5). the cytotoxic effects of free radicals are detrimental for mammalian cells and lead to cell damage through its damaging effects on peroxidation of double-chain fatty acids, protein and dna, as well as, increase oxidative stress (6). accordingly, mammalian cells have developed complicated antioxidant defense system to prevent oxidative damage and allow survival in an aerobic environment. this system includes: enzymatic activities such as superoxide dismutase (sod), catalase (cat) and glutathione peroxidase (gpx), or non-enzymatic antioxidants such as vitamins (a, c & e) and uric acid (ua) (7). the aim of the present study was to determine the possible association of oxidant/total antioxidant status and recurrent aphthous stomatitis (ras) through measuring malondialdehyde (mda) as a biomarker for oxidative stress, and evaluate the level of serum and salivary total antioxidant status (tas) of (ras) patients in a sample in basrah city. minor aphthae major aphthae herpetiform ulceration figure1: clinical presentation of ras. materials and methods patients: this study was conducted in department of oral and maxillofacial surgery at al-basrah teaching hospital and specialized teaching center for dentistry in basrah. a total of (68) subjects were in cooperated in this study. they were divided as following: recurrent aphthous stomatitis (ras) patients group: thirty eight patients of both sexes with ras were examined. those patients had recurrent oral aphthae at least three times a year(8); eight patients were excluded from this study. healthy control group: thirty gender and agematched healthy individuals were selected from the same hospital and privates (medical staff and dental students). ras was diagnosed clinically by an expert in oral medicine. patients were otherwise healthy and had active aphthous lesions during the study. they were not under a therapeutic regimen for the past 3months. patients with behcet's disease, chronic diarrhea, trauma history, any systemic disease, smoking history, alcohol drinking, or addiction were not included in the study. blood samples: five ml of venous blood samples were aspirated from anticubital vein of each individual in the morning. the whole blood was collected in sterile disposable plain tube. the blood was left to clot then the supernatant serum which was obtained by centrifugation at 3000 rpm for 10 minutes was aspirated and transferred immediately into another tube and frozen at (20°c) for subsequent analysis. haemolyzed samples were discarded, figure-2. saliva samples: five ml of unstimulated salivary samples were taken with the consent of the subjects. started to gain unstimulated saliva samples and no oral stimulus was permitted prior to collection. then the patients were told to sitcomfortably and to spit into the plastic polyethylene tubes for five minutes. the samples then were centrifuged at 3000 rpm for 10 minutes and the supernatant was aspirated then stored at (20°c) until biochemical analysis, figure-2. mda measurement: lipid peroxidation end products, particularly malondialdehyde (mda) react with thiobarburic acid (tba)under acidic condition and heating to give a pink chromogen j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of serum oral diagnosis 85 that measured spectrophotometrically at (532) nm(9). tas measurement: incubation of abts®* with a peroxidase (metmyoglobin) results in production of the radical cation abts+®*. this species is blue-green in color and can be detected at 600 nm (10). antioxidants in the added sample cause inhibition of this color production to a degree that is proportional to their concentration. this is a two-reagent assay and may be performed using either serum or saliva.tas was estimated by the use of commercially available kits randox (randox laboratory ltd., uk). serum samples saliva samples figure 2: serum and saliva samples. results the patient group comprised 16 females and 14 males, whose mean age was 34.03± 11.98 years, while the control group consisted of 16 females and 14males, whose mean age was 29.50±10.72 years. the percentage of female patients with ras (53.3%) was higher than the percentage of male patients (46.3%) with ras. clinical examination findings types of ulcer(s): out of 30 patients; the results showed that (18) patients (60%) had minor aphthous ulceration, whereas (8) patients (26.66%) had major aphthous ulceration and (4) patients (13.33%) had both minor and major ulcers. herpetiform type of ulcers was not found in those patients. chi square= 7.727, pvalue = 0.021, the distribution is significant (p<0.05). the number of ulcer(s): on examination of thirty patients with (ras); (11) patients (36.66%) had single ulcer, whereas (19) patients (63.33%) were with multiple ulcers (more than one ulcer at the time of examination). chi square = 0.010, p value = 0.919, the distribution is not significant (p>0.05). sites of ulcer(s): it has been found that twenty one patients (70%) had oral ulcers located on nonkeratinized mucosa: [upper and lower labial mucosa, labial part of commissures, labial sulci, buccal mucosa (right and left), (tip of the tongue, ventral side and margins), soft palate]. while three patients (10%) had oral ulcers on keratinized mucosa [dorsal of the tongue, attached gingiva (labial & lingual)]. whereas six patients (20%) had oral ulcers on both keratinized and nonkeratinized mucosa. chi square = 10.903, p value = 0.004, the distribution is highly significant (p<0.01). biochemical findings: table-1 & figure-3 assessment of oxidative stress marker malondialdehyde (mda):the results of this study showed that the mean of serum and salivary mda in ras patients was significantly higher (p<0.01) than that of healthy controls, using t-test. assessment of total antioxidant status (tas): the mean of serum and salivary tas in ras patients was also slightly lower than that of healthy controls, but both of them statistically was not significant (p>0.05), using t-test. table1: the mean of oxidant and total antioxidant status in serum and saliva according to the study groups comparison control groups n=30 ras patients n=30 variables pvalue t-test ±sd mean ±sd mean 0.001 3.384 0.567 5.236 0.523 5.713 serum mda µmol/l 0.001 2.971 0.639 3.886 0.762 4.426 saliva mda µmol/l 0.122 1.571 0.410 1.752 0.276 1.610 serum tasµmol/l 0.136 -1.517 0.617 2.727 0.396 2.524 saliva tas µmol/l j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of serum oral diagnosis 86 0 2 4 6 variablesserum mda µmol/l saliva mda µmol/l serum tas µmol/l saliva tas µmol/l ras control figure 3: the mean of oxidant and total antioxidant status in serum and saliva according to the study groups biochemical findings according to gender the results showed that the mean of serum and salivary mda and tas in female higher than males with ras, but statistically was not significant (p>0.05) using t-test, table-2; figure-4. table 2: the mean of oxidant and total antioxidant status in serum and saliva of patients with ras according to gender comparison female patients n=16 male patients n=14 variables pvalue t-test ±sd mean ±sd mean 0.481 -0.720 0.308 5.781 0.0.699 5.635 serum mda µmol/l 0.283 -1.094 0.806 4.568 0.703 4.264 saliva mda µmol/l 0.468 0.710 0.250 1.643 0.307 1.571 serum tasµmol/l 0.692 0.400 0.325 2.496 0.474 2.555 saliva tas µmol/l 0 2 4 6 variablesserum mda µmol/l saliva mda µmol/l serum tas µmol/l saliva tas µmol/l male figure 4: the mean of oxidant and total antioxidant status in serum and saliva of patients with ras according to gender. discussion considerable activity of reactive oxygen radicals may lead to destroyed normal cell functions and integrity of cell structures. oxidative stress in biological systems can be induced by the consumption of antioxidants and/or by an overload of oxidants species, so that antioxidant levels become deficient. it appears that imbalance between free radicals and antioxidants causes many inflammatory oral soft tissue disease varying from infections and immunological diseases to lethal cancers (6,11). clinical examination findings: gender: in the present study the results showed that females with ras formed (53.3%), while the males was (46. 6%), this was reported in most other studieswhich suggested a female predilection (12,13), but other studies showed a males predominance (14,15). j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of serum oral diagnosis 87 age: the study showed that the mean age of the patients with ras was (34.03±11.93) years, which means that ras was found to be around the 3rd decade. while, other studies have noted that the average age group to be around 4th decade (16, 17). type of ulcer(s): the results showed that patients with minor aphthous ulceration were significantly higher. this result agreed with other studies (2,4), but disagreed with (15). number of ulcer(s): this study showed that (36.66%) of aphthae cases were with single ulcer on examination; whereas (63.33%) were with multiple ulcers; this is in a positive agreement with clinical study that had been done by hashem (15). in other epidemiological study on ras by safadi (18) demonstrated that approximately half of participants reported that ulcerations were single while the other half reported them as multiple ulcerations. site of ulcer(s): in the present study the results showed that (70%) of patients with ras have aphthous lesions on non-keratinized mucosa, while (10%) located on areas of keratinized mucosa and (20%) located on both areas of keratinized and non-keratinized mucosa, which means that the percentage of patients with ras on non-keratinized mucosa was significantly higher. this could be explained on the basis that the non-keratinized mucosa areas were movable structure and least resistant and mostly affected by trauma which was the most precipitating factor in developing the aphthous ulcer. these were agreed with the results of (6, 15). biochemical findings malondialdehyde (mda):oxidation of lipids initiates a process that result in impairment of structural/ functional properties of the cell membrane, lysis of the cell and tissue damage occurs as a final result. in the current study, the serum and salivary mda which is used as a marker of lipid peroxidation was found to be significantly higher in patients with ras if compared with the control groups. these were agreed with results of hashem (15). likewise, elevation of mda was reported in previous studies in saliva and serum (19) and in erythrocytes (20) and in serum (21) of ras patients. total antioxidant status (tas):in the present study, it has been shown that there was aslightly decreased in serum and salivary tas in ras patients than healthy controls and the results showed that the mean of serum and salivary tas in males were lower than females, but not reach the significant level. these were agreed with the study of aylin sepici-dinçel et al. (22); who demonstrated that serumtas was statistically decreased in ras patients, and oxidative stress levels increased in behcet's disease and ras patients than those in healthy controls. cimen et al. (23) concluded finally that enzymatic and non-enzymatic antioxidant defenses in ras patients are defective. it can be concluded that the ras samples were under reactive oxygen species stress due to significant increase production of serum and salivary (mda) as an oxidative stress biomarker. in recent years, there are increasing reports on literature regarding application of natural antioxidant products on management of ras .these herbal preparations including extracts and/or essential oils of medical plants exhibits promising effects on shortening healing time and severity of pain in ras patients (24). references 1. jurge s, kuffer r, scully c, porter sr. mucosal disease series. number vi. recurrent aphthous stomatitis. oral dis 2006; 12 (1): 1–21. 2. greenberg ms, glick m, ship ja. burkett's oral medicine. 11th ed. hamilton: bc decker inc; 2008. p. 57-60. 3. cawson ra, odell ew. cawson's essential of oral pathology and oral medicine. 8th ed. london: elsevier science limited; 2008. p. 220-24. 4. neville bw, damm dd, allen cm, bouguot je. oral and maxillofacial pathology. 3rd ed. philadelphia: w.b. saunders company; 2008. p. 333-336. 5. momen-beitoallahi j, mansourian a, momen-heravi f, amanlou m, obradov s, sahebjamee m. assessment of salivary and serum antioxidant status in patients with recurrent aphthous stomatitis. med oral patol oral cir bucal 2010; 15(4): e557-61. 6. scully c, gorsky m, lozada-nur f. the diagnosis and management of recurrent aphthous stomatitis: a consensus approach. j am dent assoc 2003; 134:2007. 7. karincaoglu y, batcioglu k, erdem t, esrefoglu m, genc m. the levels of plasma and salivary antioxidants in the patient with recurrent aphthous stomatitis. j oral pathol med 2005; 34:7-12. 8. albanidou-farmaki e, deligiannidis a, markopoulos ak, katsares v, farmakis k, parapanissiou e. hla haplotypes in recurrent aphthous stomatitis" a mode of inheritance. int j immunogenet 2008; 35: 427-32. 9. shah sv, walker pd. evidence suggesting a role for hydroxyl radical in glycerol induced acute renal failure. am j physiol 1988; 255(3 pt 2): f438-443. 10. erel o. a new automated colorimetric method for measuring total antioxidant status. clin biochem 2005; 38: 1103-11. 11. beevi ss, rasheed am, geetha a. evaluation of oxidative stress and nitric oxide levels in patients with oral cavity cancer. jpn j clin oncol 2004; 34: 379-85. j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of serum oral diagnosis 88 12. porter sr, scully c, pedersen a. recurrent aphthous stomatitis. crit rev oral biol med 1998; 9(3): 306321. 13. eris s, ghaemi eo, moradi a, mansourian ar, rabiei mr, nosrat sb, amirchaghmaghi a, ahmadi ar. aphthous ulcer and the effective factors on its incidence among the students of golestan medical sciences. university in the north of iran. j biol sci 2007; 7(5): 830-832. 14. fernades r, tuckey t, lamp, allidina s, shaarifi s, nia d. the best treatment for recurrent aphthous ulcer. an evidence based study of the literature 2000: 30-34. 15. hashem mn. assessment of salivary and serum lipid peroxidation/ antioxidant status and c-reactive protein marker in patients with recurrent aphthous stomatitis (ras) in selected sample in baghdad city. a master thesis. department of oral diagnosis, college of dentistry, baghdad university 2012. p. 78-86. 16. ship ja. recurrent aphthous stomatitis. an update. oral surg. oral med oral path oral radiol endod 1996; 81: 141-7. 17. oh sh, han ec, lee jh, bang d. comparisons of the clinical features of recurrent aphthous stomatitis and behcet's disease. british j assoc dermatol. clinical and experimental dermatol 2009; 34: e208-e212. 18. safadi ra. prevalence of recurrent aphthous ulceration in jordanian dental patients. bmc oral health 2009; 9: 31. 19. saral y, basak k, perihan o, fikret k, ahmet a. assessment of salivary and serum antioxidant vitamins and lipid peroxidation in patients with recurrent aphthous stomatitis. tohoku j exp med 2005; 206: 305312. 20. altinyazar hc, ahmet g, rafet k, ferah a, murat u. the status of oxidants and antioxidants in the neutrophils of patients with recurrent aphthous stomatitis. turk j med sci 2006; 36: 87-91. 21. gurel a, altinyazar hc, unalacak m, armutcu f, koca r. purine catabolic enzymes and nitric oxide in patients with recurrent aphthous ulceration. oral dis 2007; 13: 570-74. 22. aylin sepici-dinçel,yeşim özkan, sevgi yardimakaydin, gülçin kaymak-karataş, meltem önder, bolkan şimşek. the association between total antioxidant status and oxidative stress in behcet's disease. scand j rheumatol 2006; 26(11):1005-1009. 23. cimen my, kaya ti, eskandari g, tursen u, ikizoglu g, atik u. oxidant/antioxidant status in patients with recurrent aphthous stomatitis. clin exp dermatol 2003; 28:647-50. 24. babaee n, mansourian a, momen-heravi f, moghadamnia a, momen-beitollahi j. the efficacy of a paste containing myrtus communis (myrtle) in the management of recurrent aphthous stomatitis. a randomized control trial. clin oral investig 2010; 14: 65-70. j bagh college dentistry vol. 28(4), december 2016 effect of disinfection restorative dentistry 16 effect of disinfection on some properties of heatvulcanized maxillofacial silicone elastomer reinforced by nano silicone dioxide madiha fouad, b.d.s. (a) mohammed moudhaffer, b.d.s., m.sc. (b) abstract background: the daily cleaning routine of the silicone maxillofacial prostheses by the patient may cause some alteration in the materials properties. the purpose of the present study was to investigate the effect of different disinfection procedures on some properties of silicon dioxide reinforced cosmesil m511 htv maxillofacial silicone. materials and methods: one hundred and sixty (160) specimens were prepared by mixing 5% sio2 nano particles and 0.5% intrinsic cream color into the silicone polymer according to manufacturer's instructions. specimens were divided into 4 groups according to the performed test (tear strength, surface hardness, surface roughness and color) with 40 specimens each. each group was further subdivided according to the disinfection procedure conducted (control, microwave exposure, neutral soap and 4% chlorhexidine gluconate). measurements for tear strength were done using universal testing machine. surface hardness test was carried out with a shore a durometer. surface roughness was analyzed with a portable digital profilometer. color change was established with a spectrophotometer. after the initial testing, all specimens were submitted to disinfection procedure 3 times a week for 60 days. measurements were repeated and data were statistically analyzed using one-way anova followed by fisher's lsd or games-howell test . results: spectrophotometer results showed non-significant decrease in the light absorbance of all experimental groups after disinfection, indicating a strong integration between the nano filler and the polymeric chains, which was not broken during the disinfection procedure. highly-significant increase in shore a hardness was recorded, while the decrease in surface roughness was highly significant in all experimental groups. tear strength reduced significantly after disinfection in all experimental groups. conclusion: disinfection seemed to cause different amount of alteration in all of the tested properties of silicone. high color stability is expected in this type of maxillofacial silicone after disinfection.although microwave exposure had increased the hardness of the material, it is considered a satisfactory disinfection procedure since it caused the least effect on the tear strength and surface roughness of the material. therefore, microwave exposure is recommended for the disinfection of maxillofacial silicone prostheses. key words: disinfection, maxillofacial prostheses, reinforced silicone. (j bagh coll dentistry 2016; 28(4)16-21) introduction despite the advances in plastic and reconstructive surgery, there are cases with extensive loss of tissues that cannot be surgically corrected because of lack of sufficient donor tissue, age and general condition of the patient.maxillofacial prostheses were introduced as a natural need of human to repair or hide their facial defect (1). since the introduction of silicone elastomer by barnhart in 1960, it has been used as the material of choice in maxillofacial prostheses due to its inertness, strength, durability biocompatibility and ease of manipulation and coloring.a successful maxillofacial prosthesis should be tough and strong, but at the same time it should remain soft and pliable in order to cope with facial movements (2). (a)m.sc. student. department of prosthodontics. college of dentistry, university of baghdad. (b)assistant professor. department of prosthodontics. college of dentistry, university of baghdad. however, deterioration of the properties of the prosthesis is a major problem that is mainly caused by environmental factors, uv light exposure, skin secretions, microbial ingrowth, use of adhesives and daily handling and cleaning of the prostheses by patient (3-8). for these reasons, facial prostheses require remake and replacement every 12-18 months, which is costly and timeconsuming for both, patients and prosthodontists (9, 10(. prosthesis hygiene is an important factor for maintaining the health of the soft tissue underneath the prosthesis and for keeping the prosthesis itself in a good condition. since silicone prostheses are in direct contact with facial tissues and fluids for extended time, microorganisms can colonize and form a biofilm leading to skin infections and degrading the prostheses material as well (11). patients usually disinfect their prosthesis for 3 to 5 minutes daily. neutral soap, chlorhexidine gluconate and using microwave exposure are some of the disinfectants used with silicone prostheses. nevertheless, the daily use of disinfectants, using aggressive chemical solutions and mechanical cleansing reduce the service-life j bagh college dentistry vol. 28(4), december 2016 effect of disinfection restorative dentistry 17 of the prosthesis and raises the need to its replacement (9,12).therefore, the disinfecting solution used must be selected with caution in order to avoid the extraction and deterioration of the material compounds during disinfection procedure (9,13). the purpose of this study was to evaluate the possible alteration in some physical and mechanical properties of silicone dioxide reinforced m511 cosmesil htv maxillofacial silicone after application of three different disinfection procedures. the properties tested are tear strength, shore a hardness, surface roughness and color stability. these properties were tested under the influence of neutral soap, 4% chlorhexidine gluconate and microwave exposure disinfection procedures. materials and methods one-hundred and sixty (160) samples were prepared according to manufacturer's instructions. the silicone used was cosmesil m511 (factor ii inc., usa) reinforced with silicone dioxide nano fillers (us research nanomaterial, usa). compounding of the nano sio2to part a (base) of the silicone was done before mixing with part b (crosslinker). the mixing ratio was 1:10 base to crosslinker with the addition of 5% nano sio2 concentration (14). cream color liquid pigment was added to the reinforced silicone at the mixing stage. the pigments were weighed in a precision scale to constitute 0.5% of the silicone weight. after mixing by a vacuum mixer, the material was injected into custom made metal molds, which were made according to the dimensions approved by iso specifications (15,16) (fig. 1). molds were sandwiched by two vaseline-coated glass slabs and closed tightly. silicone was then cured in a dry heat oven at 100 c° for 1 hour. figure 1: custom made metal molds. after polymerization, specimens were removed from the molds carefully and excess flush was trimmed with a scalpel. scanning electron microscope (sem) had been done for some samples in order to insure the homogeneity of sio2nano particles dispersion within the silicone polymeric matrix. initial testing was then performed for the following properties: a-tear strength: tear test samples were fabricated and tested according to iso 34-1:2010 specifications (15). trouser shaped samples with right angle were fabricated with 2 ± 0.2mm thickness. computerized universal testing machine (instrone) was used; samples were stretched at a rate of 500 mm\ min until rapture (17). tear strength (t) was then calculated according to the following formula: t=f/d where (f) is the maximum force exerted to break the specimen and (d) is the thickness of the specimen. b-shore a hardness test: samples were fabricated according to iso 7619-1:2010 specifications (16), the dimensions of the test samples were 25mm × 25mm × 6mm (7).samples were tested using a digital shore a durometer (ht-6510a – china).five measurements were carried out for each specimen and the average for these measurements was calculated (18,19). csurface roughness test: samples were fabricated according to iso 7619-1:2010 specifications (16), test samples have the same dimensions of the samples used for testing surface hardness (7).a portable digital roughness tester (profilometer) was used (tr 220, beijing time high technology ltd., china). 3 readings were done for each specimen, which was then transformed into mean values (19). dspectrophotometer color change: disc samples with diameter of 20mm and thickness of 2mm were fabricated according to han et al. (20). color absorption was evaluated using a spectrophotometer uv (model uv-1800, shimadzu, kyoto, japan) thereafter, specimens were divided into 3 subgroups of 40 samples and stored in a light proof container. samples were divided according to the mode of disinfection performed into: microwave exposure: samples were subjected to microwave radiation for 3 minutes at 650 w (samsung – model ms23f301eak230 v50 hz1150 w – malaysia). samples were immersed in a glass container with 200 ml of tap water which was replenished after each cycle (6,9,12). soap: samples were immersed in the solution (johnson and johnson gmbh, italy)for 75 minutes a day, and then rinsed with water(9, 12). 4% chlorhexidine gluconate: samples were immersed in the solution for 10 minutes a day and then rinse with water (5,18,21-23) all disinfection procedures were carried out 3 times a week for 60 days (18,19,22,23). after disinfection, the specimens were dried with paper j bagh college dentistry vol. 28(4), december 2016 effect of disinfection restorative dentistry 18 towel to insure that no absorption of solutions occurred, specimens were then stored again.at the end of the disinfection period, specimens were submitted to a new testing. statistical analysis of the collected data was then performed with spss 19.0 software with a significance level of 0.05. one-way anovawas used for comparing variables among groups, followed by fisher's lsd or games-howell test. results sem images had shown regular and uniform distribution of the sio2 nano particles within the polymeric matrix as shown in (fig. 2). figure 2: sem tear strength reduced significantly after disinfection in all experimental groups (table 1). microwave exposure recorded the highest tear strength (19 n\mm), whereas soap disinfection group recorded the lowest (17 n\mm). shore a hardness increased high-significantly (table 2).microwave exposure had recorded the most noticeable increase in hardness (38.55), whereas samples disinfected with chlorhexidine were the least changed (37.61). the decrement in surface roughness was highly significant after disinfection (table 3). microwave exposure was the group of least decrement in surface roughness (0.392 µm); whereas chlorhexidine gluconate disinfection was the group of highest decrement (0.227 µm) compared to the control group. spectrophotometer results had shown nonsignificant decrease in the light absorbance of all experimental groups after disinfection (table 4). samples disinfected with 4% chlorhexidine gluconate were the most color stable with the least change in light absorption (1.940%), whereas samples disinfected with microwave exposure were the least color stable with the highest reduction in light absorption (1.917%). table 1: descriptive statistics, one-way anova and lsd of tear strength control a soap b chx c microwave d anova f-test sig. groups p-value sig. n 10 10 10 10 3.501 0.025 (s) a b 0.006 hs mean 21 17 18 19 c 0.012 s sd 2.25 2.14 3.56 3.85 d 0.116 ns se 0.71 0.67 1.12 1.22 b c 0.771 ns min. 18 15 12 13 d 0.196 ns max. 25 21 24 24 c d 0.312 ns table 2: descriptive statistics, one-way anova and lsd of surface hardness control a soap b chx c microwave d anova f-test sig. groups p-value sig. n 10 10 10 10 42.575 0.000 (hs) a b 0.000 hs mean 34.835 37.710 37.610 38.550 c 0.000 hs sd 0.634 0.844 1.028 0.534 d 0.000 hs se 0.201 0.267 0.325 0.169 b c 0.777 ns min. 33.6 36.4 36.4 37.6 d 0.022 s max. 35.7 39.1 39.1 39.2 c d 0.011 s table 3: descriptive statistics, one-way anova and games-howell test of surface roughness control a soap b chx c microwave d anova f-test sig. groups p-value sig. n 10 10 10 10 102.659 0.000 (hs) a b 0.000 hs mean 0.680 0.261 0.227 0.392 c 0.000 hs sd 0.105 0.039 0.026 0.057 d 0.000 hs se 0.033 0.012 0.008 0.018 b c 0.136 ns min. 0.443 0.208 0.19 0.312 d 0.000 hs max. 0.797 0.320 0.271 0.482 c d 0.000 hs j bagh college dentistry vol. 28(4), december 2016 effect of disinfection restorative dentistry 19 table 4: descriptive statistics and one-way anova of color absorbance discussion degradation of the physical properties and discoloration of maxillofacial silicone are the main causes that necessitate replacement of the prosthesis every 6 months (24). maxillofacial silicone elastomers must have some properties which include: high tear resistance, similar hardness to the skin of the defective site and color stability (25). the changes in the physical and mechanical properties of silicone polymer after disinfection is mainly caused by structural changes in the distribution of the molecular masses due to either chain scission or further cross-linking (26,27). in order to have prosthesis with thin and fine margins that blind with the surrounding tissues, high tear strength is required. in the present study, significant reduction in the values of tear strength resulted after the disinfection period in all the experimental groups. this reduction could be attributed to the propagation of cross-linking that occurs as the material is exposed to moisture. immersion in disinfecting solutions accelerates the polymerization of silicone (28). tear strength is mainly affected by the arrangement and amount of cross-links. more flexible cross-linking arrangements yields in better tear strength, whereas high cross-linking densities tighten and brittle the network (25,29). this increase in cross-linking density continues from the mixing of the component to after the structural application. although tear strength increase upon cross-linking, it is also reduced with too high level of cross-linking due to the formation of obstacles that prevent the molecules from sliding past each other, resulting in inelastic brittle material that ruptures at lower deformation (3,26,29,30). the results of tear strength in this test was in accordance with hattamleh et al (26) and gautriaud et al (29) who claimed reduction in tear strength values after disinfection. highly-significant increase in shore a hardness was resulted irrespective of the disinfection procedure. this increase in the materials' hardness was attributed to the ongoing silicone polymerization which occurs during aging process. post-polymerization cross-linking increases the density of the polymer, leading to minimal space between the cross-links to deform to lesser distance, therefore increasing the rigidity of the material (18,19,31,32). this increase in the materials' hardness also indicates a strong association of the sio2nano-filler with the polymeric matrix. if these particles were removed during the disinfection procedure, increase in the porosity of the polymer and therefore reduction in the hardness would be expected as was indicated by goiato et al (18). microwave exposure disinfection caused the most significant increase in the materials hardness. thermal cycles which occur during microwave exposure, work against the water uptake that leads to softening of the material. in addition to that, temperature raise during microwave cycles could lead to further polymerization reaction (12,17). elastomeric structure become denser when exposed to high energy radiation due to the intensified crosslinking, which is directly proportional to the dose and duration of the radiation (26). on the contrary, chlorhexidine gluconate caused the least effect, which could be attributed to the fact that chlorhexidine is chemically inert and acts by saturation (18). considering neutral soap, disinfected specimens showed mild alteration in materials' hardness. neutral soap was considered as control disinfectant in many studies since it is chemically inert (21, 26, 33). to be clinically applicable, the hardness value of maxillofacial silicone prosthesis should be close to the hardness of the missing facial part. this value ranges from 10-45 according to eleni et al, 2013. therefore, all the changes in hardness values in the present study could be considered as clinically acceptable. the results of shore a hardness in this study were in accordance with eleni et al (3,9); goiato et al (19); hatamleh et al (26); gautriaud et al (29) who recorded increase in the elastomeric hardness after disinfection. on the contrary, eleni et al (12) had recorded decrease in the hardness of the material after disinfection; this could be attributed to the long period of immersion and different disinfecting solution. control a soap b chx c microwave d anova f-test sig. n 10 10 10 10 1.316 0.284 (ns) mean 2.090 1.929 1.940 1.917 sd 0.097 0.249 0.293 0.208 se 0.031 0.079 0.093 0.066 min. 1.930 1.631 1.426 1.623 max. 2.180 2.244 2.234 2.151 j bagh college dentistry vol. 28(4), december 2016 effect of disinfection restorative dentistry 20 surface roughness was tested in the present study since it is a good indicator for the bacterial colonization and adhesion. in addition to that, mechanical properties are also affected by the roughness of the surface since irregularities may lead to nucleation sites for cracks (24). significant reduction in the surface roughness had resulted irrespective of the disinfection procedures. this decrement is mostly attributed to the continuous polymerization process which leads to enhancement and complement of the polymeric chain structure, therefore, smoother silicone surface will results with time (19). these results were in line with goiato et al (19) but againstthe results of al-dharrab et al (24) which could be due to different disinfecting solution and longer period of immersion. color change and optical properties are the most frequent reason that makes patients seek remake for their maxillofacial prostheses (34). the type of silicone used and the duration of exposure to the disinfectant significantly affect the color stability of silicone prostheses (28). regarding color absorbance in the present study, it was the most stable property after the disinfection procedure. non-significant reduction in the absorbance of the material indicates high association of the nano-filler with the polymeric matrix, which was not removed during the disinfection procedure (5,19, 22). unlike fillers with large particles that could be washed away upon the disinfection procedure leading to color instability, the extremely small particles of the sio2 linked strongly with the polymeric matrix forming an integration that was not broken upon disinfection. these particles act as a physical barrier that prevents the silicone chromatic deterioration (5,7, 19,22). the small, yet non-significant decrease in the color absorption might be a consequence of chemical or mechanical activation (wiping the specimens before storage) that could probably washed away some of the pigment particles that accumulated on the surface of the elastomer during storage (22,33,35). due to its biocompatibility, chlorhexidine gluconate caused the least effect on the color property; whereas the change in color absorption after microwave radiation was morethan other disinfection procedures which might bedue to thermal cycling (temperature variation) that leads to structural alteration of silicone (5). nevertheless, the difference between the disinfection groups was non-significant. these results agreed with kiat-amnuay (36); haddad et al (5); griniari et al (28); hatamleh and watts (35) and disagreed with goiato et al (22,33) which could be due to different material and disinfecting procedure. references 1. zardawi fm. characterization of implant supported soft tissue prostheses produced with 3d colour printing technology. a master thesis, university of sheffield; 2012. 2. li x-n, zhao y-m, li s-b, liu x-c, wu g-f, zhen l-l and wu n. comparison of mechanical properties of cosmesil m511 and a-2186 maxillofacial silicone elastomers. j us-china med sci 2007; 4(1): 34-7. 3. eleni pn, katsavou i, krokida mk, polyzois gl, gettleman l. mechanical behavior of facial prosthetic elastomers after outdoor weathering. dent mater 2009; 25(12): 1493-502. 4. guiotti am, goiato mc, dos santos dm. marginal deterioration of the silicone for facial prosthesis with pigments after effect of storage and chemical disinfection. j craniofac surg 2010; 21(1): 142-5 5. haddad mf, goiato mc, santos dm, pesqueira aa, moreno a. color stability of maxillofacial silicone with nanoparticle pigment and opacifier submitted to disinfection and artificial aging. j biomed opt 2011; 16 (9): 095004. 6. kiat-amnuay s, johnston da, powers jm, et al. interactions of pigments and opacifiers on color stability of mdx4-4210/type a maxillofacial elastomers subjected to artificial aging. j prosthet dent 2006; 95: 249y257 7. mancuso dn, goiato mc, santos dm. color stability after accelerated aging of two silicones, pigmented or not, for use in facial prostheses. braz oral res 2009; 23(2): 144-8. 8. polyzois gl, tarantili pa, frangou mj, andreopoulos ag. physical properties of a silicone prosthetic elastomer stored in simulated skin secretions. j prosthet dent 2000; 83(5): 572-7. 9. eleni pn, perivoliotis 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elastomer. a master thesis, college of dentistry, university of baghdad; 2014. 15. iso 34-1. rubber, vulcanized or thermoplastic determination of tear strength -part 1: trouser, angle and crescent test pieces, 2010. j bagh college dentistry vol. 28(4), december 2016 effect of disinfection restorative dentistry 21 16. iso 7619-1. rubber, vulcanized or thermoplastic - determination of indentation hardness--part 1: durometer method (shore hardness) 2010. 17. machado al, breeding lc, puckett ad. effect of microwave disinfection on the hardness and adhesion of two resilient liners. j prosthet dent 2005; 94(2): 183-9. 18. goiato mc, haddad mf, santos dm, pesqueira aa, moreno a. hardness evaluation of prosthetic silicones containing opacifiers following chemical disinfection and accelerated aging. braz oral res 2010; 24(3): 303–8. 19. goiato mc, pesqueira aa, santos dm, dekon sf. evaluation of hardness and surface roughness of two maxillofacial silicones following disinfection. braz oral res 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maxillofacial material. isrn dentistry 2013. 25. hatamleh mm, watts dc. mechanical properties and bonding of maxillofacial silicone elastomers. dent mater 2010; 26(2): 185-91. 26. hatamleh mm, polyzois gl, silikas n, watts dc. effect of extraoral aging conditions on mechanical properties of maxillofacial silicone elastomer.j prosthodont 2011; 20(6): 439-46. 27. zayed sm, alshimy am, fahmy ae. effect of surface treated silicon dioxide nanoparticles on some mechanical properties of maxillofacial silicone elastomer. inter j biomater 2014; id 750398. 28. griniari p, polyzois g, papadopoulo t. color and structural changes of a maxillofacial elastomer: the effects of accelerated photoaging, disinfection and type of pigments. j appl biomater funct mater 2015; 12(2): 87-91 29. gautriaud e, stafford k, adamchuk j, simon m. effect of sterilization on the mechanical properties of silicone rubbers. saint-gobain performance plastics, 2009. 30. cheremisinoff p. handbook of engineering polymeric materials. new york: crc press; 1997. pp. 30-31. 31. polyzois gl, eleni pn, krokida mk. effect of time passage on some physical properties of silicone maxillofacial elastomers. j craniofac surg 2011; 22(5): 1617-21. 32. aziz t, waters m, jagger r. analysis of the properties of silicone rubber maxillofacial prosthetic materials. j dent 2003; 31(1): 67-74. 33. goiato mc, pesqueira aa, dos santos dm, zavanelli ac, ribeiro pp. color stability comparison of silicone facial prostheses following disinfection. j prosthodont 2009; 18(3): 2424. 34. polyzois gl, eleni pn, krokida mk. optical properties of pigmented polydimethylsiloxane prosthetic elastomers: effect of" outdoor" and" indoor" accelerating aging. j craniofac surg 2011; 22(5): 1574-8. 35. hatamleh mm, watts dc. effect of extraoral aging conditions on color stability of maxillofacial silicone elastomer. j prosthodont 2010; 19(7): 536-43. 36. kiat-amnuay s, johnston da, powers jm, rhonda f, jacob rf. color stability of dry earth pigmented maxillofacial silicone a-2186 subjected to microwave energy exposure. j prosthodont 2005; 14(2): 91-96. 37. gary jj, huget f, powell l. accelerated color change in a maxillofacial elastomer with and without pigmentation. j prosthet dent 2001; 85: 614-20. j bagh college dentistry vol. 30(3), september 2018 serum tumor 7 serum tumor necrosis factor alpha and high sensitive c-reactiveprotein as biomarkersin periodontitis in iraqi patients with osteoarthritis enas nihad muhammad, b.d.s.(1) saif s. saliem b.d.s, m.sc.(2) enas razzoqi naaom b.d.s, m.sc. p.h.d (3) abstract background: periodontitis (pd) is well-known chronic disease affecting the periodontal ligament and alveolar bone, osteoarthritis (oa) is a chronic joint disease with compound reasons characterized by synovial inflammation, subchondral bone remodeling, also the formation of osteophytes, that cause cartilage degradation. chronic periodontitis and osteoarthritis are considered widely prevalent diseases and related to tissue destruction due to chronic inflammation in general health and oral health. the aim of this study is todetermine the association of chronic periodontitis and osteoarthritits in patients by analysing tumor necrosis factor alpha tnfα and high sensitive c-reactive protein (hscrp) in the serum. materials and method: a total of 80 patients of both sexes aged 35-50 years ,30 patients with osteoarthritis and moderate chronic periodontitis (cp+oa), 30 patients of both sexes aged 35-50 years with moderate chronic periodontitis alone (cp). and control group (c) of 20 healthy patients with healthy periodontium participated in this cross sectional study. we excluded the postmenopausal and pregnant woman from female patient and smoker patient also. all patients are free of medication and have good general health with no history of systemic disease. participants with oa have documentation or radiographic imaging, consistent with degenerative arthritis in the absence of an inflammatory condition. venous blood samples were drawn from each subject using pyrogen-free heparinized collection tubes. tubes were centrifuged according to the manufacturer’s guidelines, then stored at 15°c till analyse. serum tnfα and hs crp were measured using an enzyme-linked immunosorbent assay (elisa). results: a non-significant differences between studied group regarding serum level of hscrp and tnf-α, as well as, the result revealed that the median of serum levels of hscrp were little higher in chronic periodontitis with osteoarthritis group than chronic periodontitis group and control groups represent as 0.31, 0.29, and 0.24. similarly, the medium serum level of tnfα was higher in chronic periodontitis with oathan in other two groups (10.615, 10.533, and 9.682 respectively). the age and gender showed a non-significant difference between the groups conclusion: the present study revealed that there’s a strong positive correlation between serum levels of hscrp and tnfα in patients of all groups but there is no correlation between osteoarthritis and chronic periodontitis. keywords: chronic periodontitis, osteoarthritis, tnfα, hscrp. (j bagh coll dentistry 2018; 30(3): 7-12) introduction pd, is considered one of the common oral diseases, it is a destructive inflammatory disorder affecting the tissues that support teeth and it is mostly associated with range of pathogenic bacteria (porphyromonas gingivalis, tannerella forsythia, prevotella intermedia together with aggregatibacteractinomycetem-comitans) (1), pd is characterized by both chronic inflammation of connective tissue and alveolar bone destruction which lead to loss of tooth-supporting apparatus (2). sequentially, pd followed gingivitis, which involves inflammation of marginal periodontium. however, not every gingivitis develops into pd. the progression of the periodontal destruction depends on the quantity, quality, virulence of the microorganisms and the immune response of the host (1). oa is the most important reason of disability in musculoskeletal worldwide (3), and the major factor in physical limitation of old people. (4) (2) assistant professor, department of periodontics, college of dentistry, university of baghdad. (3) lecturer department of oral surgery and peridontology college of dentistryal mustansryia university also, it is a chronic joint disease that has compound etiologies characterized with synovial inflammation, remodeling of subchondral bone, and produce osteophytes, which in turn cause cartilage deterioration, severity of oa afflicted functional ability. (5). hence, oa in most of people leads to maintain proper oral hygiene, lead to accumulation of plaque and calculus, which increases hazard of dental caries and periodontal disease (6). cytokinesact as a communication between immune and non-immune cells (7). it has been proposed that cytokines are necessary to the pathogenesis of many diseases (8). c-reactive protein is a systemic marker released during the acute phase of an inflammatory response. creactive protein is produced by the liver and is regulated by circulating cytokines, such as tnfα and interleukin1, from local and/or systemic inflammation such as periodontal inflammation (9). tnfα is a critical pro-inflammatory mediator that results in destruction of periodontal tissues. tnfα has many actions mostly pro-inflammatory. leukocyte recruitment and vascular permeability are facilitated by stimulating expression of selectins and adhesins by tnf-α, activating the osteoclasts (1) ministry of health, baghdad, iraq j bagh college dentistry vol. 30(3), september 2018 serum tumor 8 similarly to way with il-1 lead to resorption of bone and extracellular matrix. monocytes and macrophages are the most important cell types producing tnf-α(10). these cytokines are normally found in the blood and increase with inflammation so in this study we determine the level of tnfα and hscrp in the serum of the patient to determine the degree of inflammation in chronic periodontitis and osteoarthritis. materials and methods sample population consisted of eighty male and female subjects with age range 35-50 years. moderate chronic periodontitis with oa (cp+oa) group 30 subject seeking treatment in the rheumatology clinic in baghdad teaching hospital and the cp groups 30 subject, with control (c) group (20 subjects) were recruited from the attendants to iraqi national blood bank. the people enrolled voluntarily in the study in the period between december 2016 and march 2017. they were subjected to a questionnaire including question about their name, age, full medical history, dental history, medications and they were diagnosed for detecting a periodontal disease. followed by blood collection for the assessment of serum level of tnfα and hscrp. exclusion criteria: pregnant and menopause ladies, smokers, any patient with history of other chronic systemic diseases which are known to be associated with cp such as cardiovascular diseases and diabetes mellitus. also, rheumatoid patient and pd patient who received periodontal treatment and /or antibiotics during the last 3months. collection of blood samples: after the subjects have been selected,5ml of venous blood sample were aspirated from anticubital vein of each individual, using disposable plastic syringes with 23 gauge stainless steel needle. the whole blood was collected in sterile disposable plain tubes. after collection of the whole blood, centrifuging at2, 000-3, 000rpm for 20 minutes. then aspirated and transferred immediately into another tube and frozen at (-15°c) for subsequent analysis. haemolyzed samples were discarded. then, using elisa kit (96-wells) for quantitative determination of serum human tnf-α, hs crp (sunlong biotech co. ltd, china) the microelisa strip plate provided in this kit has been pre-coated with an antibody specific to tnfα and hscrp. standards or samples were added to the appropriate microelisa strip plate wells and combined to the specific antibody. statistical analysis: each patient assigned a serial identification number. the data were reviewed, cleaned with double check entry into the computer using statistical package for social sciences (spss) version 21. the overall comparison of mean values among the different study groups was done by kruskal–wallis. comparison between any two study groups was done by mann–whitney u-test. the correlation between tnf-α, hs crp and the clinical variables in each group was done by spearman's correlation test. results in this study, 80 patients were included in 3 main groups. the first group consist of 30 patients with moderate cp+oa, second group include 30 patients with moderate cp, third group is the c group consisting of 20 subjects. the age range for participants between 35-50 years. the 32 females represent 40% from the total samples and 48 males represent 60% of the total samples. from the 30 patients in cp+oa group, 13 are males (43.33%) and the others are females representing 56.67% of the group, but in cp group the number of females (9) and the males are 21 from this we observed that males are the dominant in this group and they represent 70% of the total samples. the c group, 6 females and 14 males. there were no statistical association between males and females (table 1). the age of the patient was 35-50 years, in c group the patient age from 35-42 represent 75% of the total patient in this group and the age from 43-50 was only represent 5% in the group. the cp+oa group the percentage of age from 35-42 was 43% and 43-50 was 56%, in cp group the age of the patient from 35-42 was 53% and from 43-50 was 46%. in all these groups the age distribution had no significant difference (table 2). the current study indicated that tnfα exhibited little increase in cp+oa group, the median was 10.615 as compared with cp group (10.533) and c group (9.682). analysis of results using kruskal-wallis test showed that the difference was statistically non-significant (table 3). in table 4, data showed that the hscrp was found to be high in the cp with oa the median is 0.314 followed by cp (0.289), while the lowest median of crp was in c group (0.242), and the result was statistically not significant (p>0.05). there was strong positive correlation between tnfα and hscrp in each study group as shown in table 5. j bagh college dentistry vol. 30(3), september 2018 serum tumor 9 table 1: gender distribution among study groups. group chi-square# p-value total sig control cp. only cp+oa male no. 14 21 13 5.556 0.062 48 % 70.00 70.00 43.33 60.00 % total 17.50 26.25 16.25 60.00 ns female no. 6 9 13 32 % 30.00 30.00 56.67 40.00 % total 7.50 11.25 21.25 40.00 table 2: age distribution among study groups. group chi-square# sig. total control cp. only cp+oa 35-42 years no. 15 16 13 4.916 0.086 ns 44 % 75.00 53.33 43.33 55.00 % total 18.75 20.00 16.25 55.00 43-50 years no. 5 14 17 36 % 25.00 46.67 56.67 45.00 % total 6.25 17.50 21.25 45.00 table 3: illustrates the analytic test of tnfα. group min. max. mean ±sd median mean rank kruskal-wallis x2 sig. control 5.036 34.550 11.125 6.331 9.682 38.88 0.131 0.937 ns cp only 4.552 26.557 10.662 4.387 10.533 41.08 cp+oa 4.552 16.375 10.190 2.948 10.615 41.00 table 4: illustrates the analytic test for hscrp. group min. max. mean ±sd median mean rank kruskal-wallis sig x2 p-value ns control 0.101 1.681 0.334 0.335 0.242 33.25 2.894 0.235 cp only 0.117 1.052 0.316 0.164 0.289 41.28 cp+oa 0.122 3.023 0.389 0.504 0.314 44.55 table 5: illustrates the correlation of tnfα and hscrp among study groups. groups r p-value sig control 0.512 0.021 s cp 0.581 0.001 hs cp+oa 0.694 0.000 hs discussion oa occurs in the population with a high incidence about in fourth decade of life. supporting the above fact, the groups of oa patients in the current study consisted of more females between 35-50 years, in cp+oa group, cp group the number of female was 26 (40%), and number of male 34 (60%), while the c group consisted of 6 females and 14 males. statistical analysis showed that there were non-significant differences regarding gender and these demographic data is coinciding with a study done in europe by lugonja et al. (11) they mentioned that no significant difference in terms of gender and age between cp+oa group and cp group and also agree with study of torkzaban et al. (12) which found no correlation between gender and any of periodontal indices. this study disagrees with the study done by pokrajac‐zirojevic et al. (13) which found the association between oa and gender was proven to be highly significant with female more commonly affected with oa than male (p=0.001). interestingly, the present study reported non-significant correlation of tnfα among the groups, although tnfα was increased in oa+cp group more than cp and c group, tnfα has an important role in inflammatory arthritis and in degenerative joint disease (14) it may be from the fact that human articular j bagh college dentistry vol. 30(3), september 2018 serum tumor 10 chondrocytes from oa cartilage expressed a significantly higher number of the p55 tnfα receptor which could make oa cartilage particularly susceptible to tnfα degradative stimuli(15). also associated with the level of oa severity. it is known that tnfα induces bone and extracellular matrix resorption by activating the osteoclasts, also it is secreted by leukocyte, macrophage, lymphocyte in the local lesion of pd.(16) this agree with fernandes et al.(17) who observed that high serum levels of tnfα detected in patients with cp. so it was clear that their levels increased in oa and periodontal disease but in this study the difference was statistically nonsignificant which may be related to the newly diagnosed disease, oa is a noninflammatory disease, and the proinflamatory tnfα level is still less in the serum of the patient and may be the severity of pd had moderate effect on the destruction of the supporting tissue which is reflected on the level of inflammatory markers in the serum. also, in this study the hscrp was nonsignificant related among the study groups but it was higher in oa+cp group than cp, c group. crp, is a protein mainly produced by the liver in response to an increase in interleukin-6 and tnfα, which is part of the non-specific response to inflammation, infection and tissue damage (18). there is a strong evidence that individuals with cp have elevated crp levels as compared to the c groups which agrees with previous studies conducted by martu et al. and salzberget al.(19). cpr is related to the initial host response to injuries, infections, ischemic necrosis or malignancy. it is initiated by the activation of local macrophages and other cells (including fibroblasts and endothelial cells), leading to the release of mediators such as tnfα, il-6 and il-13. these in turn cause systemic changes including hepatic release of a range of plasma proteins (including crp), activation of complement proteins and various metabolic changes. (20) this result disagrees with the study of beck et al.(21) whom assessed the relationship between crp and the periodontal status was not as clear. in spite of lack of previous study about the serum level of hscrp and tnfα in patient with moderate cp and oa, this study indicated anon-significant correlation between the markers in the study groups, it may be due to differences that can be influence crp level such as different level of inflammation regarding oa or amount of adipose tissue or the effect of body mass index (bmi), high blood pressure, alcohol use, chronic fatigue, diabetes, sleep disturbances, depression, lifestyle, in addition diet may fluctuate crp level. other factors can have influence on proinflammatory cytokine production and/or activity are the cytokines having antiinflammatory properties. for such cytokines, namely transforming growth factor (tgf)α, il-4, il-10 and il-13, have been identified as modulator for various inflammatory processes. this study found a strong positive correlation between tnfα and crp in each group which agree with foss et al.(22)whom revealed a positive correlation between the level of tnfα and hscrp that indicate when patients have high tnfα levels, a proportional increase in crp concentrations also occurs, this correlation considered that when the onset of acute-phase inflammatory response changes the concentrations of many plasma proteins, reflecting reorganization of the gene expression of hepatocyte secretory proteins after the inflammatory stimulus hscrp is the acute phase protein occurring in humans, normally, these proteins are present in small amounts in plasma, and an exacerbated increase in their rate of synthesis occurs after stimulation. a progressively increasing number of hepatocytes are recruited for crp synthesis during the first days after the inflammatory reaction. thus, persistently elevated crp levels reflect active disease, and have been reported to occur in several infections, inflammatory reactions, tumors, and lesions. as conclusion of this study, cp and oa showed no significant association in overall analysis. findings from this cross-sectional study do not provide evidence for a correlation between cp and oa. prospective research and studies using clinical criteria for diagnosis of symptomatic oa are needed to confirm these findings. references 1. saini r, marawar p, shete s, saini s. periodontitis, a true infection. j global inf dis. 2009;1(2):149-50. 2. destefano f, anda rf, kahn hs, williamson df, russell cm. dental disease and risk of coronary heart disease and mortality. bmj. 1993;306(6879):688-91. j bagh college dentistry vol. 30(3), september 2018 serum tumor 11 3. ganley tj, flynn jm, scott wn. insall scott surgery of the knee. 4. cheng yj, hootman jm, murphy lb, langmaid ga, helmick cg. centers for disease control and prevention (cdc) prevalence of doctor-diagnosed arthritis and arthritis-attributable activity limitation-united states, 2007-2009. mmwr morb mortal wkly rep. 2010;59(39):1261-5. 5. el-sherif he, kamal r, moawyah o. hand osteoarthritis and bone mineral density in postmenopausal women; 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60(6): 275-7. 18. martu s, nicolaiciuc ov, solomon s, sufaru i, scutariu mo, rezus c, popescu eu. the evaluation of the c reactive protein levels in the context of the periodontal pathogens presence in cardiovascular risk patients. rev chem (bucharest). 2017;68(5):1081-4. 19. salzberg tn, overstreet bt, rogers jd, califano jv, best am, schenkein ha. creactive protein levels in patients with aggressive periodontitis. j periodontol. 2006; 77(6): 933-9. 20. ide m, mcpartlin d, coward py, crook m, lumb p, wilson rf. effect of treatment of chronicperiodontitison levels of serum markers of acute‐phase inflammatory and vascular responses. j clin periodontol. 2003; 30(4): 33440. 21. beck jd, slade g, offenbacher s. oral disease, cardiovascular disease and systemic inflammation. periodontol 2000. 2000; 23(1): 110-20. 22. foss nt, de oliveira eb, silva cl. correlation between tnf production, increase of plasma creactiveprotein level and suppression of t lymphocyte response to concanavalin a during erythema nodosum leprosum. int j leprosy mycobact dis. 1993;61:218. الخالصة ايضا التهاب المفاصل هو حول االسنان والعظم السنخي، ما ةوانسج ةالتهاب اللثة هو مرض التهابي مزمن يؤثر على اربط :ةالخلفي النتوء تحت العظام وتكوين تشكيل ما ةوفي واعاد منها التهاب السائل الغضر ةومتداخل ةاسباب مركب ةالتهاب المفصل المزمن مع عد التهاب اللثة المزمن والتهاب المفاصل تعتبر أمراض منتشرة على نطاق واسع الغضروفي والذي يؤدي الى انحالل وتحطم الغضروف. وصحة الفم. ةوتقوم بتدمير األنسجة بسبب االلتهاب مزمن في الصحة الجسم العام بين بين مرضى التهاب ةحول االسنان في مرضى التهاب المفاصل واختبارالعالق ما ةالنسج ةالصحي ةلتقييم الحال :ةالهدف من الدراس وعامل نخر الورم الفا. ةالعالي ةالتفاعلي ذو الحساسي (cالمزمن والتهاب المفاصل من خالل تحديد مستويات المصل من البروتين ) ةاللث مع التهاب المفاصل والتهاب سنة 33إلى 03مريضا من كال الجنسين الذين تتراوح أعمارهم بين 03 ةمجموع المواد وطرق لعمل: . ةالتهاب اللثة المزمن وحد سنة من متوسط 33إلى 03مريض في كال الجنسين الذين تتراوح أعمارهم بين 03 اللثة المزمن المتوسط، بعد سن النساء ما ةاستبعدنا في هذه الدراس .ةماحول االسنان صحي ةم انسجمريضا اصحاء سريريا ولديه 03المجموعه الضابطه من أو التصوير الشعاعي، بما يتفق اليأس والنساء الحوامل والمريض المدخن أيضا. المرضى المصابين بالتهاب المفاصل مزودين بوثائق . يتم سحب عينات مصل الدم من كل مريض باستخدام ةمع التشخيص السريري اللتهاب المفاصل مع عدم وجود حالة التهابية روماتيدي حتى 53cأنابيب جمع خالية من عامل التخثر وتخضع لجهاز الطرد مركزي وفقا للمبادئ التوجيهية الشركة المصنعة، ثم تخزن في _ .والبروتين سي التفاعلي تحليل المصل من عامل نخر الورم الفا جموعة المدروسة فيما يتعلق بمستوى مصل الدم من البروتين سي التفاعلي وعامل نخر الورم وجود فروق غير معنوية بين الم النتائج: المزمن مع حول االسنان مستويات مصل الدم من البروتين سي التفاعلي كانت أعلى قليال في التهاب ماالفا وكذلك كشفت أن متوسط j bagh college dentistry vol. 30(3), september 2018 serum tumor 12 (. وبالمثل كان 3.05،3.00،3.00مزمن ومجموعات السيطرة تمثل )مجموعة التهاب المفاصل من مجموعة التهاب ماحول االسنان ال في ةمما كانت علي حول االسنان المزمن مع التهاب المفاصل أعلى في التهاب ما مستوى مصل الدم من عامل نخر الورم الفا كشفت بين المجموعات. اوي( على التوالي. وكان العمر ونوع الجنس فرقا غير معن00..53،53.300،0..53المجموعتين األخريين ) العاليه وعامل نخر الورم ةالدراسة الحالية أن هناك عالقة إيجابية قوية بين مستويات مصل الدم من البروتين سي التفاعلي ذو الحساسي .جميع المجموعات في المرضى في الفا عامل و (hscrp) التفاعلي cاظهرت الدراسة الحالية أن هناك عالقة إيجابية قوية بين مستويات مصل الدم من البروتين االستنتاج: ما حول االسنان والتهاب ةاالنسج بين التهاب ةفي المرضى من جميع المجموعات ولكن ال يوجد تاثير او عالق (tnfα) نخر الورم المفاصل. journal of baghdad college of dentistry, vol. 34, no. 3 (2022), issn (p): 1817-1869, issn (e): 2311-5270 26 research article dental aerosol hazard prevention with preprocedural antiseptic mouthwashes (comparative study) wasnaa majid hameed1*, nada jafer mh radhi2 1. master student. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad. baghdad-iraq. 2. assistant professor. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad. baghdad-iraq. *correspondence:: wasnaamajid92@gmail.com abstract background: one of the recommended methods for reducing aerosol contamination during the daily regular usage of high-speed turbine and ultrasonic scaling is the use of preprocedural mouth rinse. several agents have been investigated as a preprocedural mouth rinse. chlorhexidine significantly reduce the viable microbial content of aerosol when used as a preprocedural rinse. studies have shown that cetylpridinum chloride (cpc) mouthwash is equally effective as chlorhexidine in reducing plaque and gingivitis. this study compared the effect of 0.07% cpc to 0.2% chlorhexidine gluconate (chx) as preprocedural mouth rinses in reducing the aerosol contamination by high-speed turbine. materials and methods: 36 patients were divided into three groups based on the preprocedural rinse used (0.2% chx, 0.07% cpc and distilled water). conservative treatment was done for 20 min. (10 min before rinsing and 10 min after rinsing) in the same closed operatory for all the patients after keeping blood agar plates opened at three standardized locations (patient chest, dentist chest and at 12-inch from patient mouth). colony forming units (cfus) on blood agar plates were counted, after incubation at 37°c for 48 hr. statistical analysis was done with (spss version 21(. results: this study showed that the two antiseptic mouthwashes significantly reduced the bacterial colony forming units (cfus) in aerosol samples at three plates locations. chlorhexidine rinses were found to be superior to cetylpridinum chloride when used pre-procedurally in reducing aerolized bacteria. the number of cfus were higher at the patient’s chest location as compared to other locations. conclusion: 0.07% cpc and 0.2% chx were effective as a pre-procedural rinse in reducing cfu count during dental treatment using high-speed turbine. keywords: dental aerosol; pre-procedural mouthrinse; chlorhexidine mouthwash; cetylpyridinium chloride; colony forming units. introduction the spread of oral microbes in the dental office during various oral treatments has been a source of concern. the use of specific equipment, such as ultrasonic devices (1), high-speed dental hand-pieces (2), or three-way syringes (3), may disseminate microorganism-containing aerosols and splatters into the surroundings. aerosol is a volatile dispersion of solid or liquid particles carrying different microorganisms such as bacteria, viruses, or fungus (4). these particles and organisms may induce crossinfections at the dental office, putting patients' and dental workers' health at risk (5). ultrasonic scalers and highspeed handpieces generate more airborne contaminants than any other dental equipment (6). chlorhexidine (chx) is regarded as the gold standard chemical for reducing oral biofilm development and more potent than other compounds in reducing the levels of salivary streptococci and mutans received date: 20-10-2021 accepted date: 22-11-2021 published date:15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licen ses/by/4.0/). https://doi.org/10.26477/jb cd.v34i3.3214 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3214 https://doi.org/10.26477/jbcd.v34i3.3214 j. bagh. coll. dent. vol. 34, no. 3 2022 hameed and radhi 27 streptococci bacteria (7), or microbiological transmission via oral aerosols (8), also have many oral uses such as; control of gingivitis and periodontal diseases, (9) because of its wide antibacterial range and sustained period around the oral mucosa (10). other antiseptics, such as cetylpyridinium chloride, have been utilized as pre-procedural mouth rinses (11). cpc has significant antibacterial activity (12), and is a product that may be marketed safely (13). plaque and gingivitis effectiveness tests have been conducted on commercial mouth rinse products containing the antibacterial component cetylpyridinium chloride (cpc) (14). because of its excellent antibacterial activity, fewer side effects, and cheaper cost, cpc was offered as a suitable alternative to chx (1). as far as, no iraqi study was found to evaluate the efficacy of a preprocedural mouthrinse containing 0.07% cpc compare to 0.2% chx and distilled water in reducing the levels of viable bacteria in oral spatter during use of high-speed turbine within dental treatment. therefore, a clinical study was conducted. material and methods this study was carried out after the confirmation by the research ethics committee at college of dentistry/ university of baghdad. patients who satisfied the inclusion and exclusion criteria were included in the research, who received dental care at a private specialist dental clinic, completed an informed consent form, and their participation were entirely voluntary. total 36 patient were selected for the study, and there randomly divided into 3 groups i.e. 12 patients in each group, and without gender criteria. 1. patient’s inclusion criteria: 1patients who were over the age of 15, and had dmft ≥ 4. 2. exclusion criteria 1any patient who wore orthodontic bands or had partial removable dentures. 2a patient had soft or hard tissue tumors of the oral cavity. 3patient had a history of systemic illness or disorders. 4patient was taking antibiotics or anti-inflammatory medication prior to the trial. 5women who were pregnant or nursing. in the present study, the sample size was based on statistical analysis, 36 patients were randomly divided into four groups according to pre-rinse with mouthwash as followed: group i: control group was rinsed with distilled water (d.w) group ii: rinsed with 0.2% chlorhexidine gluconate (chx) group iii: rinsed with 0.07% cetylpyridinium chloride (cpc) methods the study was carried out at a private dental clinic in baghdad city/ iraq after gaining permission from the clinic's dentist. half an hour before the start of work, the clinic's ventilation was checked, and then the dental chair and its accessories were cleaned, and all surfaces inside the clinic were disinfected with 70% alcohol, all instruments which used during treatment were sterilized in an autoclave at 121oc and a pressure of 15 pounds per square inch (psi) for 15 minutes. then dentist, researcher and patient were used the personal protective equipments (ppe) that included; face mask, face shield, medical gloves, gown and patient towel. before dental treatment all the participants were received pi according to plaque index system (15), and dental caries following the criteria recommended by world health organization (who) (16). patients who participated within study had a conservative treatment for selected half that contained two adjacent carious teeth, the researcher putted three labeled blood agar plate (17) at three standardized locations: (18) (figure 1) j. bagh. coll. dent. vol. 34, no. 3 2022 hameed and radhi 28 • plate at patient chest • plate at dentist chest • plate at 12-inch from the patient mouth prior to the dental treatment, the high-speed turbine, handpiece, and air-water syringe were turned on and flushed for one minute to remove contaminated water caused by overnight stagnation in the water lines (19). after conservative treatment for 10 minutes, the researcher asked the patient to rinse with 10ml of mouthwash randomly for one minute and wait for 10 minutes for better retention of solution within the mouth (20), after those the new agar plates were putted in the same predestined locations and dental treatment continued for 10 minutes. the same dental clinic and the same dentist was work for all participants and only one patient was treated per day to ensure that the clinic free from aerosol contamination. after the end of time for aerosol collection the plates were closed, sealed, labelled, and immediately transferred for incubation. figure 1: position of agar plates microbiological examination after the samples were collected, the blood agar plates were incubated aerobically at 37 degrees celsius for 48 hours before being examined for the number of bacterial colony forming units (cfus/agar plate). a manual bacterial count was carried out under the guidance of a microbiologist. statistical analysis the statistical analysis was performed by statistical package for the social science (spss version 22). descriptive statistics was used as mean and standard deviation with cluster chart bars. inferential statistics were performed as one way analysis of variance anova, levene test of homogeneity of variance, shapiro wilk test of normality, dunnett t3 post hoc test for multiple pairwise comparison and paired t test. results total 36 patients were selected for the study, and there randomly divided into three equal groups i.e. 12 patients in each group. all patient were examined for pl, dmfs and dmft, and the most correlation between the dental caries (dmfs, dmft) and the colony count of bacteria was strong positive significant except for chx group was strong positive significant between dmft and cfu before rinsing and non-significant correlation after rinsing at patient chest, and weak positive non-significant for dmfs and cfu before rinsing and significant after, at dentist chest, while at 30-cm location there was weak negative non-significant before rinsing and significant relation after rinsing (table-1).while the most correlation between the plaque and the microbial colony count was weak not significant (table-2). 2 3 1 agar plates position 1. plate at the patient’s chest area. 2. plate at the dentist’s chest area. 3. plate at 12 inches (30-cm) from patient mouth j. bagh. coll. dent. vol. 34, no. 3 2022 hameed and radhi 29 table 1: the statistical correlation between caries experience (dmfs, dmft) and the colony count of aerosol bacteria in all mouthwashes groups, locations and periods. groups dmfs dmft r p r p chx pchb 0.541 0.069 0.674 0.016 pcha 0.564 0.056 0.564 0.056 dchb 0.158 0.624 0.457 0.136 dcha 0.363 0.247 0.375 0.229 30 cm b -0.186 0.563 0.073 0.822 30 cm a -0.474 0.120 -0.2750.387 cpc pchb 0.777 0.003 0.793 0.002 pcha 0.721 0.008 0.782 0.003 dchb 0.798 0.002 0.819 0.001 dcha 0.785 0.002 0.850 0.000 30cm b 0.873 0.000 0.833 0.001 30 cm a 0.753 0.005 0.789 0.002 dw pchb 0.617 0.033 0.788 0.002 pcha 0.593 0.042 0.764 0.004 dchb 0.664 0.018 0.839 0.001 dcha 0.652 0.021 0.844 0.001 30 cm b 0.665 0.018 0.798 0.002 30 cm a 0.785 0.002 0.809 0.001 table 2: the statistical correlation between plaque index and the colony count of aerosol bacteria in all mouthwashes groups, locations and periods. plate positions chx cpc dw r p r p r p pchb 0.021 0.949 -0.318 0.314 0.103 0.749 pcha -0.085 0.792 -0.343 0.275 0.083 0.797 dchb 0.182 0.572 -0.336 0.285 -0.038 0.907 dcha 0.564 0.056 -0.364 0.245 -0.152 0.636 30 cm b 0.399 0.199 -0.044 0.891 -0.107 0.740 30 cm a 0.365 0.243 -0.171 0.596 -0.094 0.772 1. location i: patient chest the mean of bacterial colony before and after treatment among groups at three positions showed within (figure 2). the mean of cfus was significantly post-rinse as compared to pre-rinse within all groups. the lowest bacterial mean was in the group that used 0.2% chx mouthwash as pre-procedural rinsing (39.333 cfus/agar plate), followed by group whose rinsed with 0.07 % cpc (55.167 cfus/agar plate) and highest mean within control group (184.917 cfus/agar plate) in patient chest location. the analysis results showed that post-rinse bacterial reduction with 0.2% chx was 86.7% followed by 0.07% cpc in the percentage of colony reduction at patient chest area with 79.2 % and least within dw group 9.7% (table 3) (figure 3) with significant difference among three groups at this location. j. bagh. coll. dent. vol. 34, no. 3 2022 hameed and radhi 30 figure 2: the mean of bacterial colony before and after treatment among groups at three positions. table 3: bacterial colony mean and percentage of reduction among groups before and after rinsing at patient chest position. groups before after mean ±sd mean ±sd % red. p *value chx 294.250 133.196 39.333 25.649 86.767 0.000 cpc 259.167 105.277 55.167 29.557 79.265 0.000 dw 205.833 58.454 184.917 49.381 9.727 0.000 f 2.213 57.855 p value 0.125 0.000* *=significant at p<0.05. figure 3: a: microbial colony growth on agar plate before rinsing at patient chest b: microbial growth after rinsing with cpc mouthwash at patient chest position. 2. location ii: dentist chest in the dentist chest area the mean number of colony after rinsing was significantly lowest within chx mouthwash group (12.250 cfus/agar plate) followed by (34.750 cfus/agar plate) for group with cpc prerinsing and highest mean was (120.000 cfus/agar plate) within control group. the colony reduction after treatment was 89.9% for chx and 80.2% with cpc mouthwash and least bacterial reduction after distilled water rinsing 13.3%, and there was significant difference found among groups in this position (table 4). j. bagh. coll. dent. vol. 34, no. 3 2022 hameed and radhi 31 table 4: bacterial count mean and reduction among groups before and after rinsing in dentist chest. groups before after mean ±sd mean ±sd % red. p *value chx 140.667 110.783 12.250 5.691 89.992 0.002 cpc 170.917 84.459 34.750 21.111 80.257 0.000 dw 137.750 47.998 120.000 45.451 13.335 0.000 f .559 45.719 p value 0.577 0.000* *=significant at p<0.05. 3. location iii: 12-inches from patient mouth the mean of bacterial colony for all groups before and after rinsing has been show within (table 5). according to statistical result there was no significant difference among groups before rinsing, while the relation was significantly difference after rinsing among three groups at this location. the lowest mean of microbial colony was showed with chx group (5.333cfu/agar plate) and group (10.167cfu/agar plate) after mouthwash rinsing with highest mean within group rinsed with distilled water (39.500cfu/agar plate). the microbial reduction was highest within groups that used chx followed by cpc mouthwash as pre-rinse with (88.5% and 82.1%) respectively, and the lowest reduction had been shown within dw rinsing (26.02%) with significant difference among group at this location at (p<0.05). table 5: bacterial count mean and reduction among groups before and after rinsing in 12-inches location groups before after mean ±sd mean ±sd % red. p*value chx 46.833 25.626 5.333 3.143 88.554 0.000 cpc 56.417 25.678 10.167 4.970 82.177 0.000 dw 53.417 18.817 39.500 15.085 26.023 0.000 f .518 46.952 p value 0.600 0.000* discussion pre-procedural mouthwash appears to be among the most efficient techniques of limiting the spread of microorganisms in the dental office, and some research has been conducted on this subject (21). the current study demonstrated a strong great relation between dental caries and colony count, which is comparable with an iraqi study (al-khayoun et al., 2015) that discovered the intensity of caries lesion to be extremely important and significantly associated with salivary mutans streptococci (22). other research has discovered a significant positive link between the quantity of functional mutans streptococci and the number of decayed, missed, and filled permanent teeth (dmft) (23, 24). the present study results are in contrast with iraqi studies that found no significant relationship between the mean number of decayed, missing, and filled primary teeth (dmft) and the number of (s. mutans), attempting to demonstrate and encourage the principle that tooth decay is a multifactorial disease influenced by a number of factors (25,26). j. bagh. coll. dent. vol. 34, no. 3 2022 hameed and radhi 32 because blood agar plates are a suitable nonselective culture medium for culturing airborne bacteria, they were used in this work to catch airborne microorganisms. when an airborne bacterium fell and grew on culture medium, it created colonies, which are measured in colony forming units (cfus) (20). the present study found that the patient's chest had the highest bacterial accumulation compared to other locations. these findings are consistent with previous studies which show that larger salivary droplets generated during dental procedures settle quickly from the air with massive contamination on the patient's chest (8, 27), because the operator was subjected to a reflecting spray instead of a direct aerosol released straight from the patient's mouth as seen in other previous studies that viewed through their results that the dentist chest area was the next higher position for bacterial concentration after the patient chest (21, 28). the control and test groups' observations demonstrate that as distance extended, the number of cfus created by aerosol reduced significantly. this finding is consistent with the findings of a 1995 research by logothesis and martinez-welles (20), who used agar plates positioned at eight standardized sites to collect aerosols and found that the number of cfus reduced as the distance from the reference point increased. cpc 0.07% had efficiency in reducing the number of cfus on the blood agar plate when used as a preprocedural mouthrinse 10 minutes prior to conservative treatment. these results are in agreement with those of a previous study that evaluated a mouthwash containing cpc as pre-rinse (11). according to the present study findings, the dentist profited the most from pre-procedural rinse. blood agar plates placed on the dentist's chest in groups that rinsed with chx or cpc had 89 percent and 80 percent less cfus, respectively, than plates from patients who rinsed with water. this protects dentists from the pathogens that are created during dental procedures. to lower the risk of cross-infection in the dental environment, it is necessary to reduce the number of germs in the oral cavity prior to the formation of the aerosol/splatter. the pre-rinse also have benefit to patient, the plate positioned on patient chest showed bacterial reduction 86% and 79% with chx and cpc prerinse mouthwashes respectively. these interventions may help patients in a variety of ways throughout dental procedures, including minimizing the likelihood of bacterial transmission to other regions of the body, such as the eyes via airborne particles (29), or even into the lungs by breathing (30). the improved efficiency of 0.2 percent chx in reducing cfus might be attributed to the fact that chx begins its antibacterial action at the time of aerosol creation as well as the start of aerosol formation. chx's antiplaque activity appears to be linked to the drug's retention in oral tissues and subsequent delayed active release (10). conclusion within the limitations of this research, the results reveal that 0.07% cpc and 0.2 % chlorhexidine as a preprocedural rinse were effective in 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apr;85(4):562-8. 19. lizzadro j, mazzotta m, girolamini l, dormi a, pellati t, cristino s. comparison between two types of dental unit waterlines: how evaluation of microbiological contamination can support risk containment. international journal of environmental research and public health. 2019 jan;16(3):328. 20. logothesis d.d., martinez-welles jm. reducing bacterial aerosol contamination with a chlorhexidine gluconate pre-rinse. the journal of the american dental association. 1995 dec 1;126(12):1634-9. 21. saini r. efficacy of preprocedural mouth rinse containing chlorine dioxide in reduction of viable bacterial count in dental aerosols during ultrasonic scaling: a double-blind, placebo-controlled clinical trial. dental hypotheses. 2015 apr 1;6(2):65. 22. al-kayoun, j. d., diab, b. s. , al-rubaii, a. y.. the relation of salivary glucose with dental caries and mutans streptococci among type1 diabetic mellitus patients aged 18-22 years. journal of baghdad college of dentistry. 2015, 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2017 23, 1-10. 27. kaur r, singh i, vandana kl, desai r. effect of chlorhexidine, povidone iodine, and ozone on microorganisms in dental aerosols: randomized double-blind clinical trial. indian journal of dental research. 2014 mar 1;25(2):160. 28. paul b, baiju rm, raseena nb, godfrey ps, shanimole pi. effect of aloe vera as a preprocedural rinse in reducing aerosol contamination during ultrasonic scaling. journal of indian society of periodontology. 2020 jan;24(1):37. 29. nejatidanesh f, khosravi z, goroohi h, badrian h, savabi o. risk of contamination of different areas of dentist's face during dental practices. international journal of preventive medicine. 2013 may;4(5):611. 30. bhattacharya s, livsey sa, wiselka m, bukhari ss. fusobacteriosis presenting as community acquired pneumonia. journal of infection. 2005 apr 1;50(3):236-9. مخاطر الرذاذ الجوي لألسنان بغسوالت الفم المطهرة قبل العمل )دراسة مقارنة(الوقاية من ندى جعفر الشيخ راضي, وسناء ماجد حميدالباحثون: الخالصة السرعة وتنظيف االسنان بالموجات فوق الصوتية هي استخدام غسول الفم إحدى الطرق الموصى بها لتقليل التلوث بالرذاذ المتطاير أثناء االستخدام اليومي المنتظم أللة حفر االسنان عالية المقدمة: لميكروبي الحيوي للرذاذ المتطاير عند استخدامه كغسول قبل عالج االسنان. تم التحقيق في العديد من العوامل مثل مضمضة الفم قبل عالج االسنان. يقلل الكلورهيكسيدين بشكل كبير من المحتوى ا ا أظهرت هذهللجراحة. قارنت اللثة. والتهاب االسنان ترسبات تقليل في الكلورهيكسيدين مثل الفعالية نفس له السيتيلبريدين كلوريد الفم غسول أن % لدراسات تأثير كلوريد 0.07الدراسة من االسنان عالية السرعة.كلورهيكسيدين جلوكونات كغسوالت للفم قبل العالج لتقليل الرذاذ المتطاير اللة حفر 0.2السيتيلبريدين مع % دقائق 10دقيقة ) 20من كلوريد السيتيلبريدين او الماء المقطر(. تم حفر االسنان لمدة 0.07كلورهيكسيدين جلوكونات, % 0.2مريض حسب نوع غسول الفم المستعمل )%36المواد والعمل: تم تقسيم ادة االسنان المغلقة لكل المرضى المشاركين بعد وضع صفائح الوسائط البكتيرية مفتوحة خالل العالج في ثالث مواقع ثابتة دقائق بعد الغسول(وتم العمل في نفس عي10قبل استعمال غسول الفم و درجة 37درجة حرارة انش من فم المريض(.تم حساب وحدة تكوين المستعمرات البكتيرية على صفائح االوساط البكتيرية بعد الحضن في -12 )صدر المريض, صدر طبيب االسنان وعلى مسافة ) spss 21)ساعة. التحليل االحصائي تم بواسطة . 48سيليزية لمدة الرذاذ عينات في البكتيرية المستعمرات تكوين وحدات من كبير بشكل يقلل المطهر الفم غسول استخدام أن الدراسة هذه أظهرت الفم النتائج: غسول ان ايجاد تم مواقع. ثالثة في الجوي لبكتيرية أعلى في موقع صدر المريض مقارنة يدين اعلى تأثيرا في تقليل الرذاذ المتطاير من كلوريد السيتيلبريدين عند استخدامه قبل عالج االسنان. وكانت عدد وحدات المستعمرات االكلورهيكس بالمواقع األخرى. % 0.2% االستنتاج: و جلوكونات لديه 0.07كلورهيكسيدين السيتيلبريدين كلوريد االسنان من عالج قبل للفم كغسوالت استخدامهم عند الجوي للرذاذ البكتيرية المستعمرات وحدة لتقليل فعالية م باستعمال الة حفر األسنان عالية السرعة. المستعمرات البكتيرية. كلمات مفتاحية: رذاذ االسنان, غسول الفم ما قبل العالج, غسول الفم الكلورهيكسيدين, كلوريد الستيلبريدين, وحدة تكوين type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 59 review article continuous chelation concept in endodontics ayat h. adham1* , ahmed h. ali2, francesco mannocci3 1ministry of health, baghdad al-rusafa health department, istiqlal sector, baghdad, iraq. 2assistant professor, aesthetic and restorative dentistry department,college of dentistry,university of baghdad, baghdad, iraq. 3department of endodontics, faculty of dentistry, oral & craniofacial sciences, centre of oral clinical & translational sciences, guy's dental hospital, king's college london, london, uk. * correspondence: ayat.hashem1204a@codental.uobaghdad.edu.iq abstract :background:continuous chelation can be defined as the concept of using a single mix of a weak chelator with naocl throughout the entire root canal preparation procedure without causing a reduction in the antimicrobial and proteolytic activity of naocl. etidronic acid, also known as "1-hydroxyethylidene-1, 1-bisphosphonate" hebp, or hedp, is a soft biocompatible chelator utilized in direct combination with sodium hypochlorite to form an all-in-one deproteinizing, disinfecting, and chelating solution. it's the only chelator available as a certified commercial product, "dual rinse hedp," approved for endodontic usage. this review aims to analyze and bring up-to-date data about the continuous chelation protocol using a combination of hedp with sodium hypochlorite in endodontic irrigation. data: only papers that were published electronically were searched within the review. sources: “google scholar”,” pubmed” websites were used for searching data by using the following keywords: : bisphosphonates, continuous chelation, dual rinse hedp, etidronate, hebp. the most relevant papers related to the topic were chosen, specifically the original articles and clinical studies, including only english-language articles from 2005 to september 2022. conclusion:combining a weak chelator with naocl solution, a single irrigation solution mixture with soft tissue dissolving ability and antibacterial properties with chelating capability can be created, which can be considered a good alternative to the conventional irrigation protocol (sequential irrigation) with naocl followed by using a strong chelator such as edta. the obvious benefit is that only one solution is required for root canal cleansing and decontamination, also decreasing the time for irrigation and providing better conditioning of root canal walls for root-filling materials. keywords: bisphosphonates, continuous chelation, dual rinse hedp, etidronate, hebp introduction the goal of a root canal treatment is three-dimensional obturation with a complete seal of the root canal system (1). sodium hypochlorite (naocl) is a proteolytic agent with significant tissue solvent action, microbicidal, and anti-biofilm properties and is utilized in concentrations ranging from (0.5–6%) (2, 3). the inorganic tissue remnants and debris that developed throughout the instrumentation technique are not removed by naocl (4). as a result, a sequestering or chelator, such as ethylenediaminetetraacetic acid (edta), the most frequently used chelator in endodontics, should be utilized afterward. this standard technique is known as sequential chelation, the most commonly applied irrigation regimen in endodontic treatment. however, it has several disadvantages, including widening in the opening of dentinal tubules, and significant decalcification of the intertubular dentin surface (5); as a result, dentin flexural strength will be reduced by these microscopic and chemical changes (6,7( .furthermore, when mixed with received date: 12-10-2022 accepted date:15-11-2022 published date: 15-12-2022 copyright: © 2022 by the authors. the article is publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/ jbcd.v34i4.3287 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/%2010.26477/jbcd.v34i3.3211 https://doi.org/%2010.26477/jbcd.v34i3.3211 https://doi.org/%2010.26477/jbcd.v34i3.3211 j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 60 naocl, edta decreases the quantity of free available chlorine, reducing naocl's tissue-dissolving ability (8). to address all of the previous issues with naocl\ edta, a new irrigation protocol based on continuous chelation was established in 2005 by dr. matthias zehnder from the university of zurich, switzerland (9). in 2012, the actual terminology was used for the first time. this protocol combines a weak chelator called etidronic acid "1-hydroxyethylidene-1, 1-bisphosphonate" hebp, or hedp, with naocl as a single irrigant solution during the instrumentation procedure (10). in 2016, a commercially certified etidronate chelation powder product dual rinse (hedp) (medcem gmbh, weinfelden, switzerland) that has been clinically approved for endodontic use became available. it’s manufactured in the form of capsules and each one contains 0.9 g powder of etidronate, which must be added to 10 ml of sodium hypochlorite solution immediately before root canal therapy, yielding a combination irrigant that contains both active chlorine and nearly 9% hedp (11). according to the studies, using a mild chelator such as etidronic acid (hedp) in a freshly formed mixture with naocl has several advantages, including not interfering with the antibacterial and tissuedissolving capabilities of the resultant mixture (9, 12), preventing the accumulation of hard tissue debris and smear layer (13), and naocl's disinfection efficacy in experimentally contaminated dentin was improved (14). to our knowledge, no previous inclusive review article on the continuous chelation protocol is in the literature. this review aims to review most, if not all, of the available studies about continuous chelation as a novel irrigation protocol. most of the research is centered on the weak chelator etidronate. methods\search strategy a comprehensive electronic search was conducted on the following websites: pubmed database and google scholar. the search was limited to manuscripts published in the english language from 2005 till september 2022 by utilizing the following keywords: bisphosphonates, continuous chelation, dual rinse hedp, etidronate, hebp. a further manual search of the references list of the relevant articles was also performed. the following types of articles were excluded: articles not published in a highly ranked journal , studies not conducted on human dentin, studies unrelated to the topic, personal opinions,editorials and social media sources. after filtering process, only 50 articles were included. common chelators used in continuous chelation in a continuous chelation protocol, a chelator combined with sodium hypochlorite can be utilized as a single irrigant throughout the root canal instrumentation procedure (15) . the chelator etidronate in this procedure is the only commercially available product (11) . nevertheless, studies exist on two additional chelators, edta and clodronate, at alkaline ph. the concentration of the anion hypochlorite, which is responsible for organic tissue disintegration, is maximized when alkalinity is maintained(12) . the characteristics of edta are affected by whether it is provided as a disodium or tetrasodium salt(9). the acidic ph of the edta disodium salt is close to neutral. the sodium hypochlorite's action disintegrates organic tissue and causes antibacterial activity, which is reduced when acidifying the media. on the other hand, the edta tetrasodium salt has a basic ph of nearly 11, making it stable with naocl without changing j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 61 its features (9, 15) . as a result of the increased depletion of free available chlorine that happens when alkaline edta (na4 edta) is combined with sodium hypochlorite, it is not suitable to be used in continuous chelation (15) . another study found that the compatibility of na4 edta with naocl is less than that of tetrasodium etidronate (na4 etidronate). after 20 minutes, the level of free available chlorine in solutions of 5% na4 edta and 2.5 % naocl was 12% at room temperature and 6% at 35 °c. as a result, it is not recommended to use these solutions in continuous chelation protocol (16) . it's thought that the better compatibility of sodium hypochlorite with hedp "etidronate" than edta is because hedp is a non-nitrogenous chelating agent that comprises phosphorus rather than nitrogen. the chlorine atoms in sodium hypochlorite have a positive charge and will attack the nitrogen atoms' electrophilic centers. because phosphorus has less electronegativity than nitrogen, it has a lower chance of reacting with naocl (17) . biel et al. (2017) compared na4edta salt with hedp, and the findings revealed that na4edta is compatible with sodium hypochlorite at low concentrations and for a short time (15) . nevertheless, for clinical practice, hedp appears to be superior to its edta counterpart (9, 15 (. despite these promising results, the combination of etidronate and naocl is chemically unstable and loses its free available chlorine with time. at room temperature, solutions containing 18% etidronate and 5% naocl (15) or 9% dual rinse \ 2.5% sodium hypochlorite(11) had a usage life of 1 and 2 hours, respectively. on the other hand, clodronate "novel chelator," is more stable in naocl combinations than etidronate(18) . recently, a study was carried out to assess the efficacy of clodronate. it was reported that a mixture of naocl and clodronate does not lose free available chlorine after 18 hours and can eradicate the smear layer, despite a reduced degree of opening of dentinal tubules than etidronate(19). similarly, etidronate or clodronate combinations with naocl were just as efficient as naocl against enterococcus.faecalis(20) . in terms of organic tissue dissolution, wright et al. (2020) found that 7.6% clodronate \2.5 % sodium hypochlorite can dissolve organic tissue just like 2.5% sodium hypochlorite (21). furthermore, clodronate combinations dissolve organic tissue with greater residual free available chlorine (fac) than etidronate mixes. however, more studies and investigations should be carried out to assess the effect of the novel chelator clodronate and its safety in a continuous chelation approach in clinical practice. biocompatibility assessment of etidronate numerous questions about biocompatibility and toxicity must be addressed whenever new materials are utilized in different concentrations or with different procedures. an in vitro study by ballal et al. (2019) assessed whether the incorporation of dual rinse hedp product into naocl induced genotoxic or cytotoxic effects using a micronucleus test for determining genotoxicity and the tetrazolium dye mtt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and the clonogenic assay for assessing cell viability. for all assays, no untoward effects were detected for the etidronate-naocl combination (22). also, a randomized safety clinical trial was performed on adult patients who presented with teeth affected by primary asymptomatic apical periodontitis comparing irrigation using 2.5% naocl with 2.5%\9%dual rinse hedp during the cleaning and shaping procedure, and it was shown that no adverse effect was found by adding etidronate to naocl)23) . j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 62 effect of continuous chelation on the properties of sodium hypochlorite: 1.effect of continuous chelation on antimicrobial\antibiofilm activity of naocl the main goal of chemomechanical endodontic treatment is the reduction or elimination of microorganisms from the root canal system (24) . adequate mechanical preparation, copious and effective irrigation, and intracanal medications are used to eliminate the bacteria and their products are required for successful root canal treatment (25) . the antibacterial effects of continuous chelation have been studied using e. faecalis (9, 14, 26-32) , and candida albicans were also included in one study(31) . alkaline edta has only been investigated in one study using colony counting and the adenosine triphosphate assay. it was determined that 10 % or 10% edta\2.5 % sodium hypochlorite was equally effective against 3-weekold e. faecalis biofilms as was 2.5 % sodium hypochlorite (30) . nevertheless, an exothermic reaction occurs when an oxidizing agent (naocl) is combined with a chelating substance frequently used in endodontics (edta or citric acid). consequently, the free available chlorine in sodium hypochlorite solutions is depleted, and their antimicrobial and tissue-dissolving abilities are compromised (33) . primarily, zehnder et al. (2005) examined the antibacterial activity of etidronate in continuous chelation using 1:10 and 1:100 dilutions of 3.5%etidronate-0.5% naocl using a planktonic suspension. the disinfection duration was 15 minutes, and it was shown that combining edta or citric acid (ca) with naocl in 1:100 dilutions decreased the latter's antibacterial activity completely. on the other hand, etidronate didn't show any adverse effect on the ability of naocl to kill bacteria. after 1 hour, the free available chlorine content was decreased by the hebp solution. this decline was dose-dependent. however, fresh mixtures contained 100% free chlorine. at the same time, the free available chlorine level in ca/naocl combinations dropped to zero in less than a minute (9) . earlier investigations have reported that mixing sodium hypochlorite with hedp resulted in a 20% reduction in fac after 1 hr. while preserving the naocl's proteolytic/antibacterial effects, making this mixture theoretically suitable for chemomechanical preparation and as a final irrigant(5, 9, 26). a clinical trial compared irrigation protocols of 9 % etidronate\2.5 % sodium hypochlorite to irrigation with 2.5 % sodium hypochlorite using paper points to sample the root canal bacteria and found that there is a lack of culturable microorganisms in 50% of the root canals in the hedp\ naocl group, compared to 40% in the 2.5 % sodium hypochlorite group, indicating that the antimicrobial efficacy of sodium hypochlorite is not affected by hedp when both irrigants are freshly mixed (34) . in the existence of a smear layer, there is little evidence about how the mixture of sodium hypochlorite with hebp exhibits antibacterial efficacy against infected dentin. morago et al. (2016) stated that the antibacterial activity of 2.5 % sodium hypochlorite when mixed with 9% hebp was unaffected by the presence of the smear layer, and the combined solution could be utilized in any condition irrespective of the smear layer amount in the walls of the root canal. if there is a smear layer, the mixed solution will eliminate it, allowing the naocl to act, and in the absence of the smear layer, there would be no interference(29) . the greater activity of naocl\ hebp compared to naocl alone is likely due to hebp's ability to remove the smear layer, permitting sodium hypochlorite to infiltrate into the structure of dentin and exert its antibacterial activity (5) . j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 63 only a few studies have been carried out on the antimicrobial effectiveness of commercial dual rinse hedp in sterile saline solution. because of the lack of antibacterial activity and the inability to remove the smear layer, hedp solution mixed with saline must not be used as a single irrigant (35) . 2.effect of continuous chelation on tissue dissolving ability of naocl the sodium hypochlorite tissue-dissolving capability is proportional to the amount of free chlorine in the solution (36) , which comprises hypochlorous acid (hocl) and the hypochlorite ion (ocl). the chelator na4edta has been used in only one tissue dissolution study, and it was reported that there was no significant difference in the percentage of reduction in bovine muscle tissue between 5-10 % tetrasodium edta\2.5 % sodium hypochlorite mixtures and a 2.5 % sodium hypochlorite control during 15 minutes (37) . tartari et al. (2015) evaluated the effect in tissue dissolution of single and combined use of sodium hypochlorite (hedp) and edta, and they found that the combination of sodium hypochlorite with edta (ph 7.4) was not associated with tissue dissolution, while the combination of sodium hypochlorite with hedp (ph 11.2) had a superior ability in tissue dissolution. as a result, hedp had only a minor effect on naocl, indicating that if utilized during instrumentation, this mixture can efficiently dissolve organic tissues (12). the non-dissolution of organic materials by the combination of sodium hypochlorite and edta could be because of the decrease in the release of the ocl ion, which encourages the tissue-dissolving action of naocl (38) . when examining the combination of sodium hypochlorite and hedp, a minor change in organic matter dissolution was found, which was most likely because this chemical is a weak chelating agent (39, 40) , which causes some reduction in the fac amount after 1 hour of mixing (9) . another etidronate study investigated the effect on the removal of bovine muscle from concavities made within human root canals by utilizing passive ultrasonic irrigation and the xp-endo shaper, and it has been shown that without activation or with the use of passive ultrasonic irrigation naocl\edta caused a similar amount of tissue removal as the water. in contrast, the effects of the combination etidronate\ naocl were comparable to plain sodium hypochlorite. all the irrigants were used in the canal for only 2 min; the result is not surprising. a 1 min application of sodium hypochlorite was followed by another min of edta for the sequence. compared to the naocl control or the etidronate-naocl mixture, the specimens in the sequence were exposed to naocl for half the time. as a result, the sequence naocl \edta is unlikely to dissolve as much organic tissue. given the short time frame, the equivalent results for the naocl control and the etidronate mixture are reasonable (41). 3. effect of temperature on naocl stability combined with etidronate heating the sodium hypochlorite/dual rinse combinations harmed the fac content, with a full loss of that component after one hour, but the pure sodium hypochlorite solutions preserved all of their fac, indicating that heating of dual rinse and naocl should be avoided. hedp breaks down into the components utilized to make it, notably acetic and phosphonic acid (42). sodium hydroxide buffers the acetic and phosphonic acids that arise. then, naocl will break down under the effect of temperature and light. then, the fac (in the forms of ocl-, hocl, and naocl) will undoubtedly be lost as soon as these reactions occur (11). on the contrary, it was found that when the naocl/hedp mixture was heated to 40°c, it dissolved more organic matter than when it was kept at ambient temperature (25°c)(43) . also, another j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 64 study has shown that heating sodium hypochlorite alone or in combination with hedp has been demonstrated to boost their ability to dissolve organic tissue and eliminate the smear layer. the temperatures of 60 °c for sodium hypochlorite alone and 37 °c for its combination with hedp were the optimum temperatures for the properties studied, but they needed to be refreshed frequently to maintain their benefits. the increase in collisions between the molecules of sodium hypochlorite and the organic tissue and the replenishment of the combination before each immersion of the specimens likely contributed to these results. nevertheless, after 10 minutes, no differences between the 37°c, 48°c, and 60°c groups were detected. heating was not advantageous for the mixture of naocl and na4edta, likely due to the quick loss of fac. because the improved efficiency of preheated solutions is restricted to the time they are vigorously introduced and the rapid temperature equilibrium inside the root canal, they must be regularly replenished throughout root canal therapy (44) . effect of continuous chelation on the chemical composition and ultrastructure of dentin rath et al. (2020) characterized and compared the effects of two different irrigation protocols on ultrastructural characteristics of dentin: sequential chelation (naocl (3.0, 6%)/17.5% edta) and continuous chelation (hedp dual rinse). they discovered that sequential chelation leads to the exposure of thick collagen bundles on the surface, whereas continuous chelation results in a thin, frail layer of exposed collagen on the surface. in contrast to the organic-components-rich dentin surface after sequential chelation treatment, continuous chelation resulted in a homogeneous organic and inorganic structure of the dentin surface. when hedp-treated dentin was compared to sodium hypochlorite/edta-treated dentin, the collagen fibers had shorter and thinner strands. the root canal dentin was imaged using a transmission electron microscope. it revealed a dense collagen network that was parallelly oriented without any loss of banding pattern in the sub-surface layer, indicating partial degradation of the surface fibers exposed by hedp and proteolyzed by sodium hypochlorite. while edta-induced dentin surface demineralization results in a surface with loosely arranged, "naked" collagen fibrils reaching up to 880 nm into the dentin(45) . effect of continuous chelation on removal of smear layer and debris from dentinal tubules the smear layer is formed during the instrumentation process due to the action of endodontic instruments during the shaping process and it should be removed as it might decrease the overall success of endodontic therapy (46) . during continuous chelation, there is some evidence that less dentin debris accumulates. in a study performed by paque et al. (2012) using microcomputed tomography, they found that debris accumulation in the isthmuses of the mesial roots of extracted lower molars was less in the case of irrigation with 9% tetrasodium etidronate\2.5% sodium hypochlorite compared to 2.5% sodium hypochlorite and this decrease seemed to occur throughout the whole root canal, including apical ramifications, rather than only in the isthmus (13) . however, comparing it with naocl is unreasonable because rinsing with edta after applying naocl has been shown to minimize dentine debris accumulation (4) . it would have been more conclusive to compare etidronate combinations to standard sequences. the smear layer is a thin layer formed during mechanical root canal instrumentation that is made up of organic and inorganic material from the dentine and pulp tissue, as well as microorganisms and their products in infected teeth (47) . j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 65 regarding continuous chelation mixture using etidronate, zehnder, et al. (2005) demonstrated that 17 % edta is more effective in eliminating the smear layer than 3.5 % tetrasodium etidronate\0.5 % sodium hypochlorite over 1 min, and this finding could be attributed to the low concentration of etidronate and the short period of application (9) . also, de-deus et al. (2008) evaluated the chelating capability of etidronate as compared with edta using co-site optical microscopy, and they revealed that edta is more effective in removing the smear layer than hebp. the kinetics of demineralization endorsed by both 9 and 18 % hebp were slower than those promoted by 17 % edta (39) . while lottani et al. (2009) showed that protocols employing 1% naocl \17% edta, 1% naocl \ 2.25% peracetic acid, and 1% naocl \9% etidronic acid left the same amounts of smear layer in the walls of the root canals. furthermore, compared to 1 % sodium hypochlorite for 15 min followed by 17 % edta for 3 min, less ca2+ is eluted from the root canal when dentine discs are subjected to 9 % tetrasodium etidronate\1% sodium hypochlorite for 15 min. as a result, the etidronic acid \naocl mixture can be used as a single irrigation solution throughout canal instrumentation without causing dentin decalcification (5) . also, kfir et al. (2020) reported that there is no substantial difference between the sequential chelation protocol (3% naocl \edta) and continuous chelation protocol (3%naocl \9%hedp) in the removal of smear layer and debris. moreover, neither protocol could completely remove the smear layer from the root canal walls (48) . the stability constant measures a chelator's capacity to bind metal ions, with a larger number suggesting stronger binding. compared to etidronate, edta has a higher stability constant (49) . deari et al. (2019) found that etidronate removed less smear layer as compared with edta at neutral ph, and this finding could be due to etidronate having lower stability constant and higher ph as compared with edta (50) . morago et al. (2016) stated that continuous irrigation with 2.5% sodium hypochlorite/9% hebp solution as a substitute for using sodium hypochlorite followed by a strong chelator resulted in less debris and smear layer. this will reduce the reactivity of sodium hypochlorite with the residual debris, which means less depletion of the fac and, thus, higher stability of the mixture (29) . conclusions continuous chelation is beneficial since it facilitates the clinical procedure while improving debris removal from the root canal. combining an oxidation-resistant chelator with naocl can expedite and simplify root canal cleaning during endodontic treatments. lastly, because of its better antibacterial effect despite a higher surface tension value, sodium hypochlorite /dual rinse hedp may be a feasible substitute for naocl + edta. directions for future studies it's unclear if continuous chelation protocol will improve the outcome of root canal therapy, especially in retreatment cases. accordingly, more clinically relevant studies should be carried out to confirm the real effectiveness of continuous chelation innovative protocol in clinical practice. furthermore, one of the main issues that should be taken into consideration is the compatibility with naocl in continuous chelation mixture and preservation of free available chlorine despite the promising results of chelators such as etidronate but still, there is gradual loss of free available chlorine with time. consequently, future studies should be conducted using other more compatible chelators such as clodronate to ensure high j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 66 maintenance of free available chlorine which results in preserving and enhancing the main functions of naocl. conflict of interest: none references: 1. mounes b, alhashimi r. the push out bond strength of bioceramic seal-er (total fill) after warm and cold obturation tech-niques an in vitro comparative. j baghdad coll dent. 2022; 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42:771-5. 29. morago a, ordinola-zapata r, ferrer-luque cm, baca p, ruiz-linares m, arias-moliz mt. influence of smear layer on the antimicrobial activity of a sodium hypochlorite/etidronic acid irrigating solution in infected dentin. j endod. 2016;42:1647-50. 30. solana c, ruiz-linares m, baca p, valderrama mj, arias-moliz mt, ferrer-luque cm. antibiofilm activity of sodium hypochlorite and alkaline tetrasodium edta solutions. j endod. 2017;43(12):2093-6. j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 68 31. tartari t, wichnieski c, bachmann l, jafelicci jr m, silva r, letra a, et al. effect of the combination of several irrigants on dentine surface properties, adsorption of chlorhexidine and adhesion of microorganisms to dentine. int endod j. 2018;51:1420-33. 32. morago a, ruiz‐linares m, ferrer‐luque cm, baca p, rodríguez archilla a, arias‐moliz mt. dentine tubule disinfection by different irrigation protocols. micros res techniq. 2019;82:558-63. 33. clarkson rm, podlich hm, moule aj. influence of ethylenediaminetetraacetic acid on the active chlorine content of sodium hypochlorite solutions when mixed in various proportions. j endod. 2011;37(4):538-43. 34. ballal n, gandhi p, shenoy pa, shenoy belle v, bhat v, rechenberg dk, et al. safety assessment of an etidronate in a sodium hypochlorite solution: randomized double‐blind trial. int endod j. 2019;52:1274-82. 35. giardino l, savadori p, generali l, mohammadi z, del fabbro m, de vecchi e, et al. antimicrobial effectiveness of etidronate powder (dual rinse® hedp) and two edta preparations against enterococcus faecalis: a preliminary laboratory study. odontology. 2020;108:396-405. 36. hand re, smith ml, harrison jw. analysis of the effect of dilution on the necrotic tissue dissolution proper ty of sodium hypochlorite. j endod. 1978;4:60-4. 37. tartari t, oda d, zancan r, da silva t, de moraes i, duarte m, et al. mixture of alkaline tetrasodium edta with sodium hypochlorite promotes in vitro smear layer removal and organic matter dissolution during biomechanical preparation. int endod j. 2017;50:106-14. 38. macedo r, wesselink p, zaccheo f, fanali d, van der sluis l. reaction rate of naocl in contact with bovine dentine: effect of activation, exposure time, concentration and ph. int endod j. 2010;43:1108-15. 39. de-deus g, zehnder m, reis c, fidel s, fidel ras, galan jr j, et al. longitudinal co-site optical microscopy study on the chelating ability of etidronate and edta using a comparative single-tooth model. j endod. 2008;34:71-5. 40. tartari t, duarte junior ap, silva junior joc, klautau eb, souza junior mhs, souza junior pdars. etidronate from medicine to endodontics: effects of different irrigation regimes on root dentin roughness. j appl oral sci. 2013;21:409-15. 41. ulusoy ö, savur i, alaçam t, çelik b. the effectiveness of various irrigation protocols on organic tissue removal from simulated internal resorption defects. int endod j. 2018;51:1030-6. 42. hoffmann t, friedel p, harnisch c, häußler l, pospiech d. investigation of thermal decomposition of phosphonic acids. j anal appl pyrol . 2012;96:43-53. 43. kim r, kim yg, kim m-y, song bc, kim s-h, kim j-h. interaction of hydroxyethylidene bisphosphonate (hebp) with other endodontic irrigants on tissue dissolving capacity and antimicrobial effect. j dent rehabil appl sci . 2017;33:106-13. 44. de hemptinne f, slaus g, vandendael m, jacquet w, de moor rj, bottenberg p. in vivo intracanal temperature evolution during endodontic treatment after the injection of room temperature or preheated sodium hypochlorite. j endod. 2015;41:1112-5. 45. rath pp, yiu ck, matinlinna jp, kishen a, neelakantan p. the effects of sequential and continuous chelation on dentin. dent mater . 2020;36:1655-65. j. bagh. coll. dent. vol. 34, no. 4 2022 adham et al 69 46. al-khafaji ha, al-huwaizi hf. cleaning efficiency of root canals using different rotary instrumentation systems: a comparative in vitro study. ijmrhs. 2019;8:89-93. 47. mccomb d, smith dc. a preliminary scanning electron microscopic study of root canals after endodontic procedures. j endod. 1975;1:238-42. 48. kfir a, goldenberg c, metzger z, hülsmann m, baxter s. cleanliness and erosion of root canal walls after irrigation with a new hedp-based solution vs. traditional sodium hypochlorite followed by edta. a scanning electron microscope study. clin oral investig. 2020;24:3699-706. 49. smith rm, martell ae. critical stability constants: second supplement: springer; 1989. 50. deari s, mohn d, zehnder m. dentine decalcification and smear layer removal by different ethylenediaminetetraacetic acid and 1‐ hydroxyethane‐1, 1‐diphosphonic acid species. int endod j. 2019;52:237-43. مفهوم االستخالب المستمر في عالج جذور األسنان فرانسيسكو مانوش , علي حامد احمد , ادهم هاشم ايات الباحثون: المستخلص التحضير طوال عملية هيبوكلوريت الصوديوم مع فضعي ستخلبعلى أنها مفهوم يتضمن استخدام مزيج واحد من ماالستخالب المستمر يمكن تعريف عملية االهداف: والمحلل الميكروبات مضادات نشاط انخفاض في التسبب دون الصوديو بأكملها لهيبوكلوريت باسم المعروف etidronic ضحم. مالبروتيني ايضا hydroxyethylidene-1, 1-bisphosphonate” "1 hebp or hedpم عن عبارة توليفة ست، في استخدامه يمكن حيويًا متوافق ناعم مع خلب مباشرة تمت الموافقة " dual rinse hedp "وهو المستخِلب الوحيد المتاح كمنتج تجاري معتمد "الكل في واحد "خلب ستهيبوكلوريت الصوديوم لتشكيل محلول مطهر وم مع hedp المستمر المبتكر باستخدام مزيج من بستحالعليه لالستخدام اللبي. تهدف هذه المراجعة إلى التحليل الشامل وتحديث البيانات الموجودة حول بروتوكول اال تم البحث فقط في األوراق التي تم نشرها إلكترونيًا ضمن : البيانات . naocl ئص هيبوكلوريت الصوديوم في الري اللبي وتأثيره على خصائص عاج قناة الجذر وخصا ,bisphosphonates باستخدام الكلمات المفتاحيه االتيه للبحث عن البيانات "pubmed" و "google تم استخدام مواقع "الباحث العلمي من :المصادرالمراجعة. continuous chelation, dual rinse hedp, etidronate, hebp: األصلية تم و المقاالت وتحديداً ، بالموضوع الصلة ذات البحثية األوراق معظم اختيار محلول هيبوكلوريت و ضعيف المستخلبمن خالل الجمع بين : االستنتاجات. 2022 ايلولحتى 2005والدراسات السريرية ، بما في ذلك مقاالت باللغة اإلنجليزية فقط من يمكن اعتبارها بديالً جيدًا للري استخالبيهخاصية مضادة للبكتيريا مع قدرة لديه األنسجة الرخوة ، و قادر على اذابة خليط محلول ري واحد يتم الحصول علىالصوديوم ، بًا لتطهير قناة الجذر وإزالة التلوث ، وكذلك تقليل وقت الري وتوفير تكييف واحدًا فقط مطلومحلوال الفائدة الواضحة هي أن هناك naocl \ edta. التقليدي باستخدام لمواد حشو الجذر أفضل لجدران قناة الجذر j bagh college dentistry vol. 31(4), december 2019 comparison between 31 comparison between the effects of aloe vera and chlorhexidine on clinical periodontal parameters sarah adil abed, b.d.s. (1) basima ghafory ali, b.d.s, m. sc.. (2) hanaa jawad mohsin, b.d.s, d.d.s, (3) abstract background: periodontal diseases are one of the major dental pathologies that affect human populations worldwide at high prevalence rates the term periodontal disease usually refers only to plaque related inflammatory disease of the dental supporting tissues. mouth rinses which act as an anti-plaque agents mostly used as adjuncts to oral hygiene. aims of the study: to estimate and compare the effects of aloe vera relative to chlorhexidine on the clinical periodontal parameters (plaque index, gingival index, bleeding on probing). material and method: a total of 44 subjects with plaque-induced gingivitis, baseline of data were collected for (pli, gi, and bop) and underwent oral hygiene instruction, scaling and polishing, then divided into: study group i : 15 patients instructed to use aloe vera mouth wash (100% pure aloe vera juice) for home application twice daily for 7 days. study group ii: 15 patients instructed to use chlorhexidine (0.2%) mouthwash twice daily for 7 days. control group: 14 patients instructed not to use any adjunct. results: pli and bop showed significant differences between 1st and 2nd visits in all groups with the larger effects were found in chlorhexidine followed by aloe vera while the lowest change was found in control group. gi showed significant change between 1st and 2n visits in study groups (chlorhexidine and aloe vera groups) with the larger effects was in chlorhexidine group, while there was no significant changes were found in control group. conclusion: chlorhexidine remain the bench mark control as adjunct to periodontal therapy but aloe vera can be used as alternative to chlorhexidine when it cannot be used. key word: aloe vera, chlorhexidine, clinical periodontal parameters. (received: 2/1/2018; accepted: 11/2/2018) introduction the term periodontal disease usually refers only to plaque related inflammatory disease of the dental supporting tissues. although wide variety of diseases of the oral mucosa can also affect the gingiva occasionally, so that conditions as diverse as tuberculosis or lichen planus can produce lesions in this area. such conditions referred as “non-plaque induced gingivitis” do not play any significant part in the development of periodontal disease in its commonly accepted sense.(1) gingivitis and periodontitis are the two main periodontal diseases and may be present concurrently. gingivitis is a form of periodontal disease in which gingival tissues are inflamed but their destruction is reversible while periodontitis is a chronic inflammatory response to the subgingival bacteria with irreversible changes.(2) chlorhexidine is (a cationic bisbiguanide) that has been used as a broad-spectrum antiseptic in medicine since the 1950s. in europe, a 0.2% concentration of chlorhexidine has been used for years as a preventive and therapeutic agent. 1. master student 2. assistant professor, department of periodontics, college of dentistry, university of baghdad. 3. assistant professor, department of periodontics, college of dentistry, university of baghdad. chlorhexidine acts either bacteriostatic or bactericidal, depending on the dose. adverse effects of chlorhexidine include an increase in calculus formation, dysgeusia (altered taste), and permanent staining of teeth.(3) it may be particularly useful for older adults who have difficulty with plaque removal and those who take phenytoin, calcium channel blockers, or cyclosporines and who are at risk for gingival hyperplasia.(4) for thousands of years and in many countries in the world, medicinal plants were traditionally used as a treatment for a variety of human diseases and persistently used as a major source of medicine in rural areas of the developing countries. about 80% of the people in developing countries use traditional medicines for their health care. medical plants contain natural products that have been demonstrated to be a copious source of biologically active compounds, many of which have been the basis for the development of new chemicals for pharmaceuticals.(5) aloe vera (lilaceae family), a cactus like plant, with a core mucilaginous tissue that has been used as a gel which act as a laxative as well as to treat multiple conditions including: sunburn, wounds, and digestive tract disorders. pharmacological attributes to aloe vera that it acts as an antibacterial, antiviral, antifungal, j bagh college dentistry vol. 31(4), december 2019 comparison between 32 antioxidant, and anti‑inflammatory.(6) aloe vera extract which may be tested as one such oral hygiene aids to reduce plaque formation .(7) aloe vera gel exhibits its wound-healing effects through several mechanisms, which include keeping the wound moist, enhance the migration of epithelial cells, quicker collagen maturation and an anti-inflammatory effect.(8) a study done by abed and al-hijazi in 2016 used aloe vera gel in periodontium defect relate its ability to accelerate wound healing as it increase syndecan 1 expression in epithelial cells, precursor progenitor cells and in early stage of cell proliferation of mesenchymal cell, and in inflammatory cells, and cementoblast.(9) glucomannan, a mannose-rich polysaccharide and gibberellin, a growth hormone, stimulate fibroblastic activity and proliferation through the interaction with growth factor receptor on the fibroblast, which in turn enhance the synthesis of collagen after topical and oral application. following oral and topical application, aloe vera has been proven to increase the hyaluronic acid and dermatan sulfate synthesis in the granulation tissue of a healing wound.(10) the objective of the study was to estimate and compare the effects of aloe vera on the clinical periodontal parameters (pli, gi, bop) as compared to chlorhexidine. materials and methods human sample a total of 44 subjects (12 males, 32 females) with plaqueinduced gingival overgrowth / age range (15-30) years attending the clinics at the department of periodontics in the teaching hospital at college of dentistry university of baghdad / iraq and al baladiyate specialized dental center . exclusion criteria: included the presence of less than twenty natural teeth, history of habits (alcohol or tobacco); any systemic situation that could affect the host’s periodontal health or that would require antibiotics treatment procedures (e.g. heart conditions and joint replacements); patients under corticosteroid therapy; use of antibiotics and/or anti-inflammatory drugs within the last three months; and drug-induced gingival enlargement; patients undergo radiation therapy or chemotherapy; gingival enlargement due to drug therapy (phenytoin, cyclosporine, or calcium channel blockers) and patients with periodontitis. study design all participants were informed about the purpose of the study and their consents were provided prior to their inclusion into the study. all the subjects were examined for checking their appropriateness for the study. then, they received baseline examination; collection of base line data include: plaque index (pli)11 , gingival index (gi)12 , and bleeding on probing(bop)13 and underwent the 1st phase of periodontal treatment including oral hygiene instructions, scaling and polishing ,then the patients divided into three group : • study group i (aloe vera group): 15 patients with gingivitis receive oral hygiene instruction and motivation, scaling and polishing, and aloe vera mouth wash for home application twice daily for seven days . • study group ii: (chlorhexidine group) 15 patients with gingivitis receive oral hygiene instruction and motivation, scaling and polishing, and chlorhexidine mouthwash twice daily for seven days . • control group: 14 patients with gingivitis, receive oral hygiene instruction and motivation, scaling and polishing . the second measurements were recorded at the second visits (after 7 days). statistical analysis data were calculated and entered into a computerized data base structure. statistical analysis was done using spss software. mean and sd, paired t-test, and the effect of size (ez) for normally distributed data and median, mean rank, wilcoxon sign rank, and ez for not normally distributed data. level of significance was 0.05 . results plaque index : table (1) reveals descriptive and statistical changes in plaque index between the visits. plaque index showed high significant changes between visits in all groups with the greatest changes in chlorhexidine group as the median values were changed (from 1.340 to 0.58) at 1st and 2nd visits respectively, followed by aloe vera group as the median values at 1st visit and 2nd visit were (1.650) and (0.82) respectively while the lowest changes were in control group as the median values at 1st visit and 2nd visit were (1.575) and (1.005) respectively. the effect of size (ez) showed large value in all groups with highest value chlorhexidine group (0.8805), followed by aloe vera group (0.8655) while the lowest value were in control group (0.8650) . gingival index : table (2) reveals descriptive and statistical changes in gingiva index between the visits. gingival index showed high significant changes between visits in study group with the greatest j bagh college dentistry vol. 31(4), december 2019 comparison between 33 changes in chlorhexidine group as the median values at 1st and 2nd visits were changed (from 1.65 to 1.30) respectively, followed by aloe vera group (from 1.64 to 1.27) respectively while there is a significant changes between the visits in control group as (from 1.62 to 1.5) respectively. the effect of size (ez) showed large value in chlorhexidine group and aloe vera group with highest value in chlorhexidine group (0.8799), followed by aloe vera group (0.865) while the control group showed medium effect of size (0.596) . bleeding on probing: table (3) reveal descriptive and statistical changes in bleeding in probing (bop) between the visits. bleeding of probing shows significant changes between visits in all groups with the greatest changes in chlorhexidine group as the mean value at 1st and 2nd visits were (64.400, 32.100) respectively, followed by aloe vera group as the mean value at 1st visit and 2nd visit were (59.200, 26.560) respectively while the lowest changes between visits were in control group as the mean value at 1st visit and 2nd visit were (61.143, 50.779) respectively . the effect of size (ez) showed large value in all groups with highest value in chlorhexidine group (1.722), followed by aloe vera group (1.682) while the lowest value were in control group (1.630) j bagh college dentistry vol. 31(4), december 2019 comparison between 34 discussion plaque index showed high significant reduction between the first and second visits in all study and control groups. this may indicate good oral hygiene instructions and motivation as well as an appropriate maintaining of oral hygiene over the period of the study time, and also may related to the antimicrobial activity of chlorhexidine that exhibits anti-microbial effects against grampositive, gram-negative, yeast and fungi5 a study done by al-timimi and al-casey in 2012 showed that chlorhexidine is still more effective than other agents in reduction the counts of salivary streptococci and mutans streptococci bacteria when compared to thymus vulgaris extract and normal saline.(14) as well as the antimicrobial effect aloe vera as it is very effective in fighting of bacteria and preventing gingival inflammation .(15) gingival index showed high significant reduction between the first and second visits in the study groups (chlorhexidine and aloe vera). this may attributed to wound healing and antiinflammatory effect of aloe vera constituents on gingival tissue as they obstruct the cyclooxygenase pathway and reduce prostaglandine e2 that results in reduction of gingival inflammation. aloe vera also contains vitamin c which involved in synthesis of collagen as well as increase o2 concentration in the site of inflammation that lead to fibroblast activation and the proliferation of collagen in this area.(8, 16) bleeding on probing shows high significant reduction between first and second visits in all groups which may indicates that there were an adequate reduction in the inflammatory process after scaling and polishing as well as maintaining of a good patients personal oral hygiene practice throughout the time of the study, also it related to the reduction effect of aloe vera in the instances of gingival bleeding as it have healing and soothing properties, reduce swelling, and soft tissue edema that lead to stop the bleeding and to the restoration of gingival tissue health.(17) it also may indicate the anti-plaque activity of chlorhexidine as it has a wide range inhibition of glycosidic and proteolytic bacterial dental plaque enzymes and also has concentration dependent bacteriostatic and bactericidal effects, in the fact that wound healing is more likely to be affected by the presence of pathogenic bacteria.(18) these results were in agreement with the results of the studies done by (cchina, 2016) and similar results have been reported by (nair and malaiappan, 2016; gupta et al, 2014; karim et al, 2014; and vangipuram et al, 2016). j bagh college dentistry vol. 31(4), december 2019 comparison between 35 references 1. roderick a. cawson, edward w. odell, 2008, essentials of oral pathology and oral medicine, 8th edition, churchill living stone . 2. catalina pisoschi, camelia stanciulescu and monica banita.,2012, growth factors and connective tissue homeostasis in periodontal disease, nurcan buduneli (ed.), isbn: 978-953-307-924-0, intech, available from: http://www.intechopen.com/books/pathogenesis-andtreatment-of-periodontitis/growth-factors-andconnective-tissue-homeostasis-in-periodontal-disease . 3. american dental association: guide to dental therapeutics, 2000, ed 2,chicago, ada 4. spackman ss, bauer jg, 2015, carranza’s clinical periodontology, 12th edition, saunders, an imprint of elsevier inc., 447-450 . 5. matos f. j. a., sousa m. p., a. craveiro a., and matos m. e. o., , 2004,constituintes qu´ımicos ativos e propriedades biol´ogicas de plantas medicinais brasileiras, editora da ufc, fortaleza, brazil, 2nd edition ., 6. chhina s, singh a, menon i, singh r, sharma a, aggarwal v. a randomized clinical study for comparative evaluation of aloe vera and 0.2% chlorhexidine gluconate mouthwash efficacy on de‑ novo plaque formation. j int soc prevent communit dent 2016;6:251-5 . .7 gupta rk, gupta d, bhaskar dj, yadav a, obaid k, mishra s,2014, preliminary antiplaque efficacy of aloe vera mouthwash on 4 day plaque re-growth model: randomized control trial, ethiop j health sci. vol. 24, no. 2,139-144 . 8. josias h., 2008, hamman composition and applications of aloe vera leaf gel. molecules;13:1599–616. 9. abed, s. and al-hijazi, a. ,2016, “expression of syndecan 1 on periodontium treated with topical application of aloe-vera”, journal of baghdad college of dentistry, 28(3), pp. 82-86. doi: 10.12816/0031129. 10. chithra r, sajithlal gb, chandrakasan g., 1998, influence of aloe vera on collegan characterstic in healing dermal wound in rats. mol cell biochem. ; 181:71–6. 11. silness j.,löe h..periodontal disease in pregnancy ii. correlation between oral hygiene and periodontal condition. acta odontologica scandinavica, 1964; 22(1): 121-135 . 12. löe h.the gingival index, the plaque index and the retention index systems. j periodontol. 1967; 38(6):610-6 . 13. newman m.g, carranza f.a , takei h.h..clinical periodontology 8th edition, philadelphia .wb saunders company (1996);169:356-357 . 14. al-timimi, e. and al-casey, m. (1) “effect of thymus vulgaris extract on streptococci and mutans streptococci, in comparison to chlorhexidine gluconate (in vivo study)”, journal of baghdad college of dentistry, 24(3), pp. 116-121. available at: http://jbcd.uobaghdad.edu.iq/index.php/jbcd/article/vi ew/1309 (accessed: 31august2019). 15. vangipuram s, jha a, bhashyamm. comparative efficacy of aloe vera mouthwash and chlorhexidine on periodontal health: a randomized con-trolled trial.j clin exp dent. 2016;8(4):e442-7. http://www.medicinaoral.com/odo/volumenes/v8i4/jce dv8i4p442.pdf 16. nair aa, malaiappan s, 2016, the comparison of the antiplaque effect of aloe vera, chlorhexidine and placebo mouth washes on gingivitis patients, j. pharm. sci. & res. vol. 8(11), 2016, 1295-1300 . 17. namiranian h and serino g., 2012, the effect of a toothpaste containing aloe vera on established gingivitis. swedish dental journal, 36(4), 179–185 . 18. lang np, schild u, bragger u, 1994, effect of chlorhexidine(0,12%) rinses on periodontal tissue healing after tooth extraction, (i), clinical parameters, jclinperi-odontol1994; 21:415 421,©munksgaard. 19. karim b, bhaskar dj, agali c, gupta d, gupta rk, jain a, kanwar a, effect of aloe vera mouthwash on periodontal health: triple blind randomized control trial; 2014, 13: 1, 14-19. الخالصة يشير مصطلح أمراض اللثة عادة .خلفية: أمراض اللثة هي واحدة من أمراض األسنان الرئيسية التي تؤثر على السكان في جميع أنحاء العالم بمعدالت انتشار عالية .ل مساعدة لنظافة الفمفقط إلى مرض التهاب اللويحات المرتبطة باألنسجة الداعمة لألسنان. غسول الفم الذي يعمل كعوامل مضادة للوحة غالبًا ما يستخدم كعوام سيدين على المعلمات اللثوية السريرية )مؤشر البالك ، مؤشر اللثة ، النزيف أهداف الدراسة: تقدير ومقارنة آثار األلو فيرا او جل الصبار بالنسبة إلى الكلورهيك .عند التسبير( شخًصا مصابين بالتهاب اللثة الناجم عن البالك وخضعوا لتعليمات 44المواد والطريقة: تم جمع ما مجموعه (bop ، و pli ،gi)كلمريض ثم قسموا الى ٪ 100مرض تلقوا التعليمات الستخدام غسل الفم الصبار ) 1:15قسموا إلى: مجموعة الدراسة ، وتم جمع البيانات األساسية النظافة الفموية ، التنظيف والتلميع دين مريضاً تلقوا تعليمات باستخدام غسول الفم بالكلورهكسي 15أيام. مجموعة الدراسة الثانية: 7عصير الصبار النقي( لالستخدام المنزلي مرتين يوميا لمدة .مريضا تلقوا : تعليمات بعدم استخدام أي مساعد 14أيام. مجموعة االضابطةة 7٪( مرتين يوميًا لمدة 0.2) نما تم العثور على أقل افروق ذات داللة إحصائية بين الزيارات األولى والثانية في جميع المجموعات ذات التأثيرات األكبر في الكلورهيكسيدين تليها الصبار بي ظهر فرق واضح مجموعات الدراسة )مجموعات الكلورهيكسيدين واأللو 2و 1النتائج: الزيارات أظهر bop و pli ن في المجموعة الضابطة. اما تغيير . giفيرا( مع اآلثار األكبر كان في مجموعة الكلورهيكسيدين ، في حين لم يكن هناك تغييرات كبيرة وجدت في المجموعة الضابطة يدين عندما ال ة: يظل الكلورهيكسيدين عنصر التحكم في عالمة مقاعد البدالء كعامل مساعد لعالج اللثة ولكن يمكن استخدام األلو فيرا كبديل للكلورهكسالخالص .يمكن استخدامه .الكلمة األساسية: الصبار ، الكلورهيكسيدين ، معلمات اللثة السريرية journal of baghdad college of dentistry, vol. 34, no.3 (2022), issn (p): 1817-1869, issn (e): 2311-5270 58 review article different methods of canine retractionpart 1 mohammed nahidh 1*, yassir a. yassir 2, grant t. mcintyr3 1 ph.d. student, department of orthodontics, college of dentistry, university of baghdad, baghdad, iraq 2 assistant professor, department of orthodontics, college of dentistry, university of baghdad, baghdad, iraq. bab-almoadham, p.o. box 1417, baghdad, iraq. 3 honorary professor of orthodontics. school of dentistry, university of dundee, uk * correspondence: m_nahidh79@codental.uobaghdad.edu.iq abstract background: this review aimed at explaining different methods of canine retraction along the archwire. methods: searching for different methods of canine retraction using fixed orthodontic appliances was carried out using different databases, including pubmed central, science direct, wiley online library, the cochrane library, textbooks, google scholar, research gate, and hand searching from 1930 till february 2022. results: after excluding the duplicate articles, papers describing the methods of canine retraction along the archwires were included. the most commonly used methods are niti closed coil spring and elastic chain. conclusions: various methods of canine retraction along the archwires were explained in detail regarding their advantages, disadvantages, and comparisons among different methods supported by clinical trials, systematic review, and meta-analysis. the preferred method is canine retraction with niti closed coil spring with 150 and 200 gm. elastic chain is considered an alternative, low-cost option. keywords: canine, retraction, fixed appliance, frictional technique. introduction orthodontic correction of different malocclusions may entail extraction of some teeth to create space for alignment and retraction of the anterior teeth. such a case like class ii and bimaxillary proclination may need extraction of first premolars and retraction of anterior teeth. anterior teeth retraction can be performed by two major methods: two stages and one-stage (en-masse) methods (1). the uses, advantages, and disadvantages of each method will be discussed below. two-stage space closure (separate canine retraction) tweed (2) advocated two stages of space closure involving canine distalization followed by retraction of incisors. he believed that by this method, the anchorage would be preserved as light force will be applied to distalize the canine to be ligated then in the anchorage unit with the posterior teeth;after that, the retraction of incisors will be commenced. two-stage retraction is used to manage cases with severe anterior teeth crowding, flared incisors, extruded or high canines, and midline discrepancies (3). there are some arguments about anchorage preservation by this method compared to one-stage retraction although heo et al. (4) proved no significant difference in terms of anchorage loss of posterior teeth and amount of retraction of anterior teeth between the two methods. there are many disadvantages to this method (3): 1. it is a more complicated procedure. 2. relatively unaesthetic as momentary space will be created distal to the lateral incisor after canine retraction. received date: 2-2-2022 accepted date: 1-3-2022 published date: 15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license. (https://creativecommons.org/licen ses/by/4.0/). https://doi.org/10.26477/j bcd.v34i3.3217 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3217 https://doi.org/10.26477/jbcd.v34i3.3217 j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 59 3. it takes a longer treatment time. 4. iatrogenic extrusion of the incisors may occur resulting in an anterior deep bite. one-stage space closure (en-masse retraction) this method was developed by bennett and mclaughlin (5) utilizing a 0.019×0.025 inch stainless steel archwire to retract the whole anterior teeth at one time using an active tie-back extended from the hook of the molar band to a soldered hook distal to the lateral incisors. the tie-back is an elastic module stretched twice its length (about 2-3 mm) to produce 50-150 gm force resulting in space closure at a rate of 0.5-1.5 mm per month. this tie-back is usually replaced every 4-6 weeks. the main advantages of this method included: 1. it takes a relatively shorter time. 2. anchorage is comparable with two stages retraction method. 3. uncomplicated method and takes less chairside time. 4. the dental arches are controlled by heavy gauge rectangular archwires. while the disadvantages included: 1. variable force levels in case of using elastic chain. 2. the elastics may slip off their position. 3. using an elastic band may be compromised by the patient's cooperation. 4. using a closed coil spring may cause tipping and binding if excessive force is applied. canine retraction generally, canine retraction can be performed using removable or fixed orthodontic appliances. with the fixed orthodontic appliance, canines will be retracted by two principal methods; either by sliding along the archwire (frictional retraction) or by sliding with the archwire (frictionless retraction) (3). each method has advantages and disadvantages that will be discussed in detail. some other methods that combined both techniques or utilize new technique may also be present. canine retraction along the archwire (frictional technique) in this technique, the canine will move along the archwire by sliding, just like train movement on rails. it is performed on a continuous stainless steel archwire extended from the molar to the molar on the other side using many tractions means like elastics and springs (6-8). this technique has the following advantages (7,9): 1. simple technique. 2. changing elastic is very easy, and archwire removal is not required. 3. elastic traction can be applied from buccal and lingual sides to reduce the rotation and flaring. 4. no complicated wire configurations are needed, so less chair-side time is required, and patients get more comfort and can maintain oral hygiene effectively. on the other hand, there are many disadvantages inherited with this technique like: j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 60 1. any interaction between archwire, brackets, and ligatures causes friction and binding, making mechanics unpredictable, impairing tooth movement, and affecting anchorage (9). 2. using flexible archwires or excessive force during retraction may cause extrusion of incisors resulting in an iatrogenic anterior deep bite (10). 3. problems associated with using elastics for retraction include cleaning, breakage, difficulty assessing the force applied, and rapid decay (7,11). methods of canine retraction along the archwire reviewing the literature revealed that there are eight methods for distalization of canine along the archwire according to the type of traction means: (1) elastic thread. (2) elastic chain. (3) elastic ligature. (4) elastic bands. (5) coil springs. (6) extra-oral traction using j-hook. (7) sliding jig and traction. (8) lace-back. (1) elastic thread according to daskalogiannakis (12), an elastic thread can be defined as a stretchable thread produced from elastic materials and used mainly to apply forces that move teeth (figure 1). it is one of the oldest methods used to retract the canines, usually coming in two forms and two sizes: the cotton covered and the plain uncovered thread with 0.625 mm (0.025 inches) and 0.75 mm (0.030 inches) in size. it retracts the canines by tying in a figure of eight under the archwire either from the second premolar or the first molar. here the canine must be loosely ligated with stainless steel ligature wire to prevent its rotation upon retraction; moreover, the second premolar and first molar must be ligated firmly to get adequate anchorage. with this method, the canine must be retracted on a rigid, closely fitting to the bracket's slot archwire; otherwise, retraction on a thin and flexible archwire with excessive force will lead to bowing of the archwire (roller coaster effect) and the development of iatrogenic anterior deep bite and posterior open bite with mesial tilting of the posterior teeth (loss of anchorage) (3), so this method is not recommended to retract canines on thin and flexible archwires. farrant (6) summarized the advantages and disadvantages of this method as follows: advantages j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 61 1. elastic thread is neat and comfortable for the patient. 2. it has remarkably good elastic properties. 3. no need for the patient's cooperation. 4. the cotton-covered type of elastic thread is easier to knot firmly. 5. the uncovered thread is supposed to remain clean in the mouth. 6. regarding the size, the 0.75 mm thread provides a greater force than the 0.625 mm one. 7. the 0.625 mm thread is thin enough not to contact the archwire when ligated to the canine's bracket. disadvantages 1. tying the knot is time-wasting. 2. the cotton-covered elastic threads become dirty in the mouth after a short tying period because of food adherence, unlike the uncovered thread. 3. the uncovered thread is slick, so the knot can gradually loosen and become untied if not it is pulled very tight. 4. it can cause cheek irritation if not tucked out carefully. 5. the amount of force applied is difficult to adjust. 6. unlike 0.75 mm thread which is relatively bulky, the 0.625 mm thread can be cut upon tying on the edge of the bracket. figure (1): using of elastic thread for canine retraction in the lower arch (2) elastic chain (elastomeric power chain) it is one type of elastic module that comes in a chain of connected elastomeric rings of different configurations like the closed-loop, short, and long filaments depending on the amount of distance between the rings in a passive state(12). it is considered the most popular space closure method by sliding along the archwire, like in the case of canine retraction by stretching from the canine to the second premolar brackets or the hook of the molar tube (figure 2). like the elastic thread, the second premolar and first molar must be connected tightly with steel ligature wire. the main advantages of the elastic chain are: (6,7,13,14) 1. simple to apply. 2. inexpensive. 3. easy to be replaced with no need to remove the archwire (less chair time). 4. no need for the patient's cooperation. 5. it causes minimal food stagnation. 6. it can be applied from the buccal and lingual directions, minimizing rotation's side effect during retraction. j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 62 while the disadvantages are: 1. forces applied are tricky to assess, and the forces reduce rapidly (force decay) with wearing (11,15), although a power chain with low force decay is available now. 2. it may break if not appropriately placed(7). 3. difficult to clean, absorb saliva, and stain easily with dietary foods and beverages (7). 4. depending on its attachment to the canine bracket, if it engages the whole wing of the bracket, it will cause tooth rotation and may increase the friction and binding that decrease the rate of tooth movement and threaten the anchorage (11,16,17). 5. needs monthly replacement in order for the force remains adequate for retraction (18). figure (2): using of elastic chain for canine retraction (3) elastic ligature (active tie-back) bennett and mclaughlin (5) introduced this method for en-mass retraction of anterior teeth and can be used for canine retraction too. the retraction is performed on a rigid stainless steel archwire with the canine ligated loosely with steel ligature wire. in this method, a single elastic ligature is attached to the hook of the canine by ligature wires extending from the hook of the first molar (figure 3). the activation of this elastic tie-back is done by tightening the ligature wire so that the elastic ligature will be twice its original size to produce a force of about 50-150 gm. the tie-back can be replaced every four to six weeks. figure (3): using of active tie-back for canine retraction (4) elastic band an elastic band is an elastomeric ring used to generate forces to move teeth depending on its purpose, location, and orientation (12). it can be used in a single arch (intra-maxillary) or between both arches (intermaxillary). it may be hooked over a prefabricated ligature hook (kobayashi ligatures), attached to the hook of the brackets or welded hook on the archwire (figure 4). using an elastic band is helpful to tip the mesially angulated canine distally along a thin and flexible archwire using light force, yet it is not indicated for retracting an already upright canine that needs bodily movement (6). j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 63 advantages 1. simple in wearing and removal. 2. the force of retraction is light and predetermined. 3. it can be applied easily by the patients using elastic director. disadvantages 1. needs the patient's cooperation. 2. it is not an effective method to retract the canine bodily along the archwire as the strong elastic is required for this action which may cause rotation and excessive binding of the canine; moreover, the force is brutal to be directed along the archwire. figure (4): using of elastic band for canine retraction (5) coil springs basically, coil springs can be classified into open and closed also either on or off the archwire. open coil spring may be utilized as an inter-canine coil, push coil, pull the coil, push-pull coil, and open rotation coil. the closed coil may be called a closed rotation coil, contraction coil (single or double nagamoto), or a pletcher t-spring (19). an open coil spring is a wound spring activated by compression and applied a net "pushing" force in two directions away from its center. the closed one is activated by tension so that the applied force is pulling or retraction (20). the coil spring is usually made of stainless steel, nickel-titanium, or co-cr-ni alloy, and it may be coated (tooth tone) to get maximum esthetics. regarding the open coil spring, the nickel-titanium one is preferred over the stainless steel because it delivers continuous force for opening or holding spaces between teeth (21). many methods have been utilized for the coil springs to retract canine (6): (a) threaded onto the archwire and compressed between the two canine brackets; (b) compressed between a soldered stop on the archwire and the canine bracket; (c) compressed between an incisor bracket and the canine; (d) compressed by a tie-back ligature; (e) expanded tied back coil spring and (f) niti closed spring between the first molar or miniscrew and canine. (a) coil spring threaded onto the archwire and compressed between the canine brackets j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 64 a piece of push coil spring with a length of less than ¾ of the distance between the canines is cut and threaded on the archwire, excluding the incisors (figure 5). the canines must be ligated loosely with stainless steel ligature wire to prevent their rotation during movement. the archwire must be rigid and closely fit the bracket slot and must not be cinched down at each end distal to the molar tubes to prevent the reciprocal forward movement of the archwire (6,19). advantages 1. constant force can be delivered over a long distance. 2. it requires little reactivation. 3. the applied force can be easily quantified. disadvantages 1. irritation of the lip. 2. unaesthetic. 3. unhygienic. 4. buccal distortion of the archwire will cause an increase in the inter-canine width during distal movement of the canines due to the distal and lateral components of the force exerted by the spring. 5. lingual root torque of the molars due to the lingual distortion of the wire ends that occurs simultaneously with the buccal distortion. 6. mesial movement of the molars will have occurred if the wire ends cinched back because the length of the wire will be shortened by this bend. figure (5): canine distal movement with coil spring between the canine brackets (b) coil spring compressed between a soldered stop on the archwire and the canine bracket a soldered post or small piece of wire is soldered on either side of the archwire to stop at the distal margin of the lateral incisor or between the lateral and central incisors (figure 6). a piece of a little more than half the distance from the stop to the canine is threaded on the archwire, which should closely fit the bracket's slot. again the canine must be ligated loosely with steel ligature wire (6). j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 65 advantages 1. irritation of the lip is less than the longer one. 2. the applied force can be measured easily. 3. the amount of reactivation is little either by using a small piece of coil spring (2 mm length left distal to the canine) or with a flowable composite or metal stop. disadvantages 1. annealing the archwire due to soldering the stop may be anticipated, so crimpable stops are preferred. 2. increase in the inter-canine distance but less than that with the long one. 3. it needs frequent reactivations. (c) coil springs compressed between an incisor bracket and the canine tooth in this method, a piece of push coil is threaded on the archwire between the brackets of the canine and lateral incisor or between the canine and central incisor (figure 6). this method is good in closing median diastema by the reciprocal action of the coil spring on the incisors. the canine and incisor must be ligated loosely. care must be taken to ligate the central incisor when the push coil is between the canine and lateral incisor brackets to prevent moving the central incisor out of alignment. the advantages are just like in point b (6). figure (6): canine retraction using coil spring compressed between a soldered stop on the archwire and the canine bracket in the lower arch and coil springs compressed between an incisor bracket and the canine tooth in the upper arch (d) coil spring compressed by a tie-back ligature a piece of 3-4 mm length coil spring is threaded on a rigid, closely fit the bracket's slot archwire just mesial to the canine activated by stainless steel ligature wire extends from the brackets of a second premolar or first molar (which must be ligated tightly to preserve the anchorage) to pull the coil spring compressing it against the canine (figure 7). in order to reduce the possibility of ligature wire fracture, the whole length of the tie-back ligature from the coil spring to the second premolar must be twisted and lying alongside the archwire so as not to interfere with the movement of the canine (6). advantages j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 66 it can be easily activated by just tightening or retying the tie-back ligature. disadvantages 1. a ligature tie extended from the first molar is too long and liable to damage. 2. interference with canine movement may be anticipated because of the difficulty in placement. (e) tied back expanded coil spring in this method, a closed coil spring instead of an open coil spring is used. a piece of 5 mm. length of closed spring is used to distalize, not push (mesialize) the canine. a ligature wire is threaded to the last four or three coils of the spring and tied loosely to the brackets of the canine from one side and the hook of the molar band (tube) from the other side, then the ligature is pulled tightly to activate the spring by opening it (figure 7). the spring lies alongside the archwire, not threaded on it because of insufficient space to activate a length of closed coil spring on the archwire. this method is indicated to retract mesially angulated canine along a thin and flexible archwire and retract canine bodily along a rigid archwire (6). advantages 1. instant application of the coil spring with no need to remove the archwire. 2. the applied force can be readily calculated. 3. simple reactivation of the spring by just tightening the ligature wire around the molar tube. 4. as the coil is located behind the canine, the inter-canine width will not be increased. disadvantages 1. the possibility of damage is high as it is not threaded on the archwire. 2. fracture of the ligature tie is inevitable, which may stop the movement of the canine or cause trauma to the patient's lip or cheek. 3. the spring tends to trap food (unhygienic). figure (7): canine distalization using coil spring compressed by a tie-back ligature in the upper arch and using tied back expanded coil spring in the lower arch j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 67 (f) niti closed spring between the first molar or mini-screw and canine this type of spring is manufactured from nickel-titanium alloy and indicated to close large spaces when infrequent adjustment is preferred (22). it is available in 6, 9, and 12 mm and three levels of force; light, medium, and heavy. some types are provided with a large diameter stainless steel key-end eyelet that fits the head of miniscrews. it can be extended from the first molar hook to the canine for the canine retraction or to a soldered hook or crimpable hook located just distal to the lateral incisor for en-masse retraction. it can also be tied to the miniscrews for the same purposes (figure 8). bonding a modified long hook or power arm above the canine bracket to act as a point of attachment near the canine's center of resistance is preferred when canine retraction is performed on miniscrews (23). advantages 1. compared to the elastomeric chain, it produces more consistent space closure till the terminal of the deactivation stage is reached. 2. it can be placed and removed easily without archwire removal. 3. it does not need reactivation at each appointment. disadvantages it is relatively unhygienic in comparison with elastomeric chains. figure (8): canine retraction using niti closed spring (6) extra-oral traction using j-hook by this method, the canine can be retracted either in the maxillary arch or in both arches (with some modification) also on both flexible and rigid archwires using extra-oral force and intra-oral attachment of either ready-made or manually bent small open circle to be hooked directly on the archwire mesial to the canine brackets that are ligated loosely with steel ligature wire. the direction of pulling must be as near as possible along the occlusal plane during the maxillary canine retraction (figure 9). using this technique to retract all four canines mutually, a high pull headgear can be used for the maxillary canines while a straight pull for the mandibular ones (7). advantages 1anchorage is conserved as the reaction outside the oral cavity (head). j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 68 2when a retraction is performed on a rigid archwire, the possibility of tipping is minimized to some extent. 3overjet reduction may frequently be seen. 4bite opening may be seen, which is beneficial in treating deep bite cases. disadvantages 1patient cooperation is a significant issue. 2the force application is intermittent, so canine retraction may be slower. 3the chance of developing soreness at the corners of the mouth from the side piece arms is high. figure (9): canine retraction with j-hook. (7) sliding jig and traction one of the methods used to retract the canine is a sliding jig with elastic for traction. it is made of a piece of 0.55 mm round wire or 0.017×0.022 inch rectangular wire that slides on the main archwire. a piece of 4 mm length open coil spring is threaded on the archwire to be between the circle of the jig and the mesial surface of the canine's bracket (figure 10). the traction force is applied to the jig's hook using either intraor intermaxillary elastics or extra-oral traction that compressed the coil spring against the canine bracket. the canine is preferably retracted on a rigid archwire (6). advantages 1. bodily movement of the canine is expected because the exerted force by the elastics is directed along the archwire. 2. the possibility of developing soreness of the corners of the mouth is decreased by using eot as the jig will bring the point of force application of the eot forward. disadvantages 1. the jig is relatively difficult to fabricate. 2. it should be fabricated with the correct length to allow free distal movement of the canine. j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 69 3. it may rotate around the archwire and become trapped under the bracket. 4. it may cause cheek irritation and food trapping because it is bulky. figure (10): canine retraction using sliding jig and elastic traction (8) lace back it is a 0.010 or 0.009-inch stainless steel ligature wire that extends from the hook of the first molar tube or band to the canine bracket in a figure of eight light ligations under the archwire (figure 11). it is used mainly to maintain the anchorage by restricting the crown of the canine from tipping forward during the leveling and alignment stage, but it has been shown that it is effective in canine retraction without causing unwanted tipping. the mechanism of canine retraction by the lace-back can be explained by the initial slight distal tipping of the crown of the canine followed by a period of rebound due to the effect of the archwire in aligning the teeth during which distal movement of the root of the canine is achieved. it can be adjusted monthly by tightening about 1-2 mm (24). advantages 1. easy to perform. 2. not need patient cooperation. 3. cheap. 4. less chair time. 5. it produced more controlled canine movement in the sagittal, vertical, and transverse planes. disadvantages the amount and rate of canine movement are less than the superelastic niti closed coil springs. j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 70 figure (11): canine retraction with lace-back evidence about mechanics of space closure with the presence of various canine retraction methods, choosing the best method for the patients and orthodontists is crucial. many randomized and non-randomized clinical trials have been done to compare the rate of space closure using different techniques. sonis et al. (18) compared the rate of canine retraction using elastic thread and two types of elastomeric chains and found a non-significant difference among the groups. they concluded that the elastomeric chain is more hygienic and needs less chair-time in its application than the elastic thread. comparing the rate of space closure using niti coil spring and tie-back, many studies (25-30) have shown that niti spring produced a significantly greater and more consistent rate of space closure than the modules with no difference clinically regarding tooth position. along with the findings of the previous studies, samuels et al. (31) evaluated the rate of teeth movement during retraction along the archwire using niti closed coil spring with different force levels (100,150 and 200 grams) in comparison with elastic active tie-back and found that at the force levels of 150 and 200 grams, there was no significant difference in the rate of space closure between these two force levels and the movement was faster in comparison with either spring delivered 100 grams force or the active tie-back. sonis (21) compared the rate of canine retraction using niti closed coil spring compared to the 3/16" elastic band and found that the spring produced a rate of canine distal movement of nearly twice as rapid as elastic bands with the advantage of excluding the patient's cooperation. dixon et al. (13) compared three space closure methods: niti closed coil spring, elastomeric power chain, and active tie-back. they found that niti coil spring produced a more rapid rate of space closure than other methods, on the other hand, the elastomeric power chain offered a cheaper treatment modality that was as effective as the spring, on the other hand, active tie-back was the slowest option. this conclusion is confirmed in mahobia and mahobia's study (32). nevertheless, mitra et al. (33) concluded that active tie-back is better than elastic chain in space closure. many studies (34-41) compared the rate of space closure between niti closed coil spring and elastomeric chain and found that both of them have the same rate of space closure. this can be confirmed by a recent study carried out by barsoum et al. (42), who found the same findings regarding the rate of tipping, rotation distal movement of canine also root resorption. sueri and turk (43) compared the effects of lace back and niti closed coil spring in canine distalization during the leveling and aligning stage and found that lace back is effective in retracting canine, but the j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 71 rate of distal movement was slower significantly in comparison with the spring. nevertheless, a more controlled canine movement was obtained in three planes of space was gained with the lace back. norman et al. (44) compared the rate of space closure using stainless steel and niti closed coil spring and found that stainless steel closed the space as rapidly as the niti one. goyal et al. (45) evaluated the effectiveness of niti and stainless steel closed coil spring, elastic chain and active tie-back in closing extraction spaces and found that the stainless steel spring was clinically as effective as the niti one in addition to its lower cost, so it can be considered as a good alternative to ni-ti coil spring. on the other hand, active tie-back was as efficient as the elastomeric chain with no significant difference in the rate of retraction between the two groups. finally, according to the latest systematic reviews and meta-analyses, the findings of the previous studies have been confirmed regarding the efficiency of power chain and niti spring in space closure with low to moderate-quality evidence that niti spring produced a faster rate of space closure (46,47). on the other hand, the quality of evidence is moderate in favor of niti coil springs in comparison with the active tie-back (47). further studies are needed to find evidence for any difference between different means of space closure in terms of anchorage loss. conclusions various methods of canine retraction along the archwires were explained in detail regarding their advantages, disadvantages, and comparisons among different methods supported by clinical trials, systematic reviews, and meta-analyses. the preferred method is canine retraction with niti closed coil spring with 150 and 200 gm force. elastic chain is considered an alternative, low-cost option. the orthodontists' preference, the state of malocclusion, and the anchorage demand may guide the orthodontist to select the best retraction method. conflict of interest: none. references 1. littlewood, sj., mitchell, l. an introduction to orthodontics. 5th ed. oxford: oxford university press; 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17(10): 70–75. 40. davidović, mu., savić, ma., arbutina, a. examination of postextraction space closure speed using elastic chains and niti closed coil springs. serbian dent j. 2018; 65(4): 179–186. 41. barlow, m., kula, k. factors influencing efficiency of sliding mechanics to close extraction space: a systematic review. orthod craniofacial res. 2008; 11(2): 65-73. 42. barsoum, ha., elsayed, hs., el sharaby, fa., palomo, jm., mostafa, ya. comprehensive comparison of canine retraction using niti closed coil springs vs. elastomeric chains: a split-mouth randomized controlled trial. angle orthod. 2021; 91(4): 441–448. 43. sueri, my., turk, t. effectiveness of laceback ligatures on maxillary canine retraction. angle orthod. 2006; 76(6): 1010-1014. 44. norman, nh., worthington, h., chadwick, sm. nickel titanium springs versus stainless steel springs: a randomized clinical trial of two methods of space closure. j orthod. 2016; 43(3): 176–185. 45. goyal, t., munjal, s., singh, s., natt, as., singh, h. a comparative evaluation of space closure using different force delivery systems a clinical study. j adv med dent sci res. 2020; 8(5): 56-60. 46. mohammed, h., rizk, mz,, wafaie, k., almuzian, m. effectiveness of nickel-titanium springs vs. elastomeric chains in orthodontic space closure: a systematic review and meta-analysis. orthod craniofacial res. 2018; 21(1): 12–19. 47. sebastian, b., bhuvaraghan, a., thiruvenkatachari, b. orthodontic space closure in sliding mechanics: a systematic review and meta-analysis. eur j orthod. 2021; 1-16. doi:10.1093/ejo/cjab047. j. bagh. coll. dent. vol. 34, no. 3. 2022 nahidh et al 74 الجزء االول -العنوان: الطرق المختلفة لسحب الناب 2، ياسر عبد الكاظم ياسر 1الباحثون: محمد ناهض المستخلص المراجعة إلى شرح الطرق المختلفة لسحب االنياب على طول السلك المقوس. الخلفية: هدفت هذه و pubmed centralي ذلك الطرق: تم إجراء البحث عن طرق مختلفة لسحب االنياب باستخدام أجهزة تقويم األسنان الثابتة باالستعانة بقواعد بيانات مختلفة ، بما ف science direct وwiley online library تبة ومكcochrane والكتب المدرسية وgoogle scholar وresearch gate والبحث اليدوي من عام . 2022حتى فبراير. 1930 قة هي النوابض الملفوفة المغلالنتائج: بعد استبعاد المقاالت المكررة ، تم تضمين األوراق التي تصف طرق سحب االنياب على طول األسالك المقوسة. أكثر الطرق شيوعًا niti .والسلسلة المرنة المختلفة التي تدعمها التجارب االستنتاجات: تم شرح طرق مختلفة لسحب االنياب على طول األسالك المقوسة بالتفصيل فيما يتعلق بمزاياها وعيوبها ومقارنتها بين الطرق جم. تعتبر السلسلة المرنة خياًرا 200و 150بقوة nitiتخدام نابض ملفي مغلق السريرية والمراجعة المنهجية والتحليل التلوي. الطريقة المفضلة هي سحب الناب باس بديالً منخفض التكلفة. aseel f.doc j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 8 the effect of solo and sodium hypochlorite disinfectant on some properties of different types of dental stone aseel m. al-khafaji, b.d.s., m.sc. (1) shorouq m. abass, b.d.s., m.sc. (1) bayan s. khalaf, b.d.s., m.sc. (1) abstract background: dental casts come into direct contact with impression materials and other items that are contaminated by saliva and blood from a patient's mouth, leaving the casts susceptible to cross-contamination. the disinfectant solutions of the impression materials cause various adverse reactions. therefore, disinfection of dental casts may be effective in preventing cross infection. this study was carried out to evaluate the surface hardness, dimensional accuracy, reproduction of details and surface porosity of type iii, type iv and type iv extra hard dental stone after immersion in and spray by using solo and sodium hypochlorite disinfectant solutions. materials and methods: 240 stone samples were prepared in rubber rings, a total of 60 test block were prepared for each test (surface hardness, dimensional accuracy, reproduction of details and surface porosity).the samples were divided into three groups (20 for each type of stone) type (iii, iv, iv extra hard); solo and sodium hypochlorite disinfectant by 2 methods (immersion and spray) were used in each test. results: the results of dimensional accuracy, reproduction of details, surface hardness and surface porosity revealed no significant difference for all types of tested stone samples after immersion or spraying in solo and naocl except the surface hardness of type iv extra hard showed significant difference after spray with solo and the surface porosity of type iv extra hard showed significant difference after immersed in both solo and naocl solutions. conclusions: based on the results of this study immersion in and spray by using solo and naocl disinfectant solutions produced no adverse effect on dimensional accuracy, reproduction of details, surface hardness and surface porosity for type iii, type iv dental stone and for type iv extra hard dental stone except for the surface hardness for type iv extra hard when sprayed with solo and the surface porosity when type iv extra hard stone immersed in the solo and naocl solutions. key words: dental stone, immersion, spraying, solo, sodium hypochlorite. (j bagh coll dentistry 2013; 25(2):8-17). introduction dentistry is predominantly a field of surgery, involving exposure to blood and other potentially infectious materials therefore requires a high standard of infection control and safety practice in controlling cross-contamination. the cross contamination with stone casts is especially present in prosthodontics because of multiple opportunities for the transfer of infectious agents to the casts through impressions, record bases, occlusion rims, and trial dentures (15). in 1996, the ada along with the national association of dental laboratories of the united states (nadl) formulated (infection control recommendations for the dental office and dental laboratory), which for the first time included recommendations for the commercial laboratory as well as the dental office (6,7) .the disinfection of the impression is difficult and associated with several problems, so the disinfection of casts became an important procedure for obtaining uncontaminated models thus establishing a cross-contamination control procedure (8-10). it is important that disinfectant solutions should not only be effective as antimicrobial agents, but also should not degrade the physical properties of the gypsum casts (11). (1) lecturer, department of prosthodontics, collage of dentistry, baghdad university. american dental association (ada) and the centers for disease control and prevention have suggested methods for the disinfection of dental casts, including immersion in or spraying with a disinfectant. other methods for disinfection of the casts include incorporating chemicals into gypsum at the time of mixing or using die stone containing a disinfectant (6, 12-15). disinfection by soaking in chemical materials has been shown to cover all surfaces in one time, while spraying is not capable of disinfecting all surfaces effectively and also cannot cover all undercuts. contrary to immersing, spraying can significantly reduce the amount of distortion (16,17). sodium hypochlorite is one of the original and most widely used disinfectants (11, 18). the literature shows that it is effective against a broad spectrum of micro-organisms including human immunodeficiency virus, viruses ,fungi, bacterial species and their spores (19-26). ivanovski et al in 1995 found that alteration in the physical properties of the casts resulted when the sodium hypochlorite disinfectants was incorporated into dental stone (14). while breault et al reported that the addition of a solution of sodium hypochlorite actually increases the compressive strength of gypsum and decreases the setting time, but leaves other physical properties unchanged (27). on the j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 9 other hand kumar et al in 2012 (11) found that repeated immersion of type iii dental stone specimens in slurry of distilled water with sodium hypochlorite and glutaraldehyde, along with drying in air, caused a significant increase in linear dimension and a significant decrease in hardness. sarma and neiman reported that sodium hypochlorite produced the least undesirable effects with regard to surface erosion, surface hardness, compressive strength, and chemical reactivity when compared with gluteraldehyde, phenol and iodophor. (28) some studies showed that the casts should be sprayed rather than immersed in disinfecting solutions like berko in 2001 who found that spraying with madacide could be used to disinfect dental cast with least effect when compared with the other methods(immersion and incorporation).(29) while other studies like tarik &al-ameer found that the immersion method had more inhibitory effect to the microorganism followed by incorporation method and the least inhibitory effect was for spray method.(30) michael et al 2010 studied the change in the compressive strength and surface roughness of type iv dental stone casts after several times of immersion or spraying with sodium hypochlorite disinfectant solution. the results showed that both spraying and immersion significantly decreased the compressive strength after 24 hours and increased the value of the roughness, with immersion as a higher value (31).also, lucas et al found that reproduction of details, dimensional stability, and setting time of the type iv die stone specimens were significantly altered when sodium hypochlorite was added to the stone. (32) while abdullah in 2006 demonstrated that repeated immersion of stone in slurry with water and slurry with sodium hypochlorite caused some degree of damage to surface details, increase in linear dimension and decrease in wet compressive strength. (33) in 2012 abass et al reported that solo disinfectant solution produced no adverse effect on the color stability, surface hardness, and surface roughness of the hot cure, cold cure, and soft acrylic denture lining materials (34). the purpose of this study was to investigate the change in the surface hardness, dimensional accuracy, reproduction of details and surface porosity of type (iii, iv, iv extra hard) of dental stone after immersion or spraying with sodium hypochlorite and solo disinfectant solution. the hypothesis was that the immersion or spraying in naocl and solo solution disinfection procedure could influences the dimensional stability, reproduction of details, surface porosity, and surface hardness of type (iii, iv,iv extra hard) of dental stone. materials and methods disinfectant solutions used in this study were: 1-solo disinfectant solution (solo, ebiox ltd., healthcare enterprise house, uk.) diluted to 2% according to the manufacturer’s instructions and duration of immersion was 5 min. 2sodium hypochlorite solution (fas (6% w/v), baghdad, iraq), the sodium hypochlorite solution was diluted to 0.6 % by using the household bleach of hypochlorite solution and diluted with water at a ratio of 1 part of bleach: to 10 parts of water to make 1:10 ratio and the samples were immersed in this solution for 10 minutes (35) according to the ada recommendation for disinfection. spray procedure was done by spraying the stone specimens with the disinfectant solution until saturation of the surface of the specimens was apparent, that is the liquid spray no longer penetrated the stone whereby the liquid residue was evident on the stone surface. while the disinfection by immersion was done by using a suitable sized container filled with fresh disinfectant solutions that cover the stone samples completely. preparation of the dental stone specimens: three types of dental stone were subjected to solo & sodium hypochlorite (naocl) disinfectant solution by two different ways (spray & immersion).the stone selected was: 1. type iii dental stone (elite model, zhermack, italy), 2. type iv dental die stone (elite stone, zhermack, italy) 3. type iv extra hard dental die stone (elite rock, zhermack, italy) an electronic balance and a measuring cylinder were used for measuring the stone and water according to the manufacturer’s instructions, after hand mixing the mixture was poured in rubber ring with dimensions of 20mm height and 30mm diameter which was used for making the stone samples. constant manual vibration was used during the pouring process of the mixed dental stone to draw out air bubbles from the mixture and reduce porosity. glass slabs were placed on the upper and lower borders of the rubber ring, to obtain samples with flat and parallel surfaces. all stone specimens were removed gently from the rubber ring after one hour of mixing and left for 24 hour at an average room temperature of 21˚c and average relative humidity of 40 % j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 10 before measurement and during the duration of the testing period. a total of 240 samples were prepared; 60 samples for each tested group (dimensional accuracy, reproduction of details, surface porosity and microhardness), for each test the samples were divided to twelve groups according to the types of the investigated stone and the types of the disinfectant and the method of disinfectant procedure as shown in table 1. as listed below:fig1 group 1: type iii dental stone, immersed in solo disinfectant group 2: type iii dental stone, sprayed by solo disinfectant group 3: type iii dental stone, immersed in nacl disinfectant group 4: type iii dental stone, sprayed by nacl disinfectant group 5: type iv dental stone, immersed in solo disinfectant group 6: type iv dental stone, sprayed by solo disinfectant group 7: type iv dental stone, immersed in nacl disinfectant group 8: type iv dental stone, sprayed by nacl disinfectant group 9: type iv extra hard dental stone, immersed in solo disinfectant group 10: type iv extra hard dental stone, sprayed by solo disinfectant group 11: type iv extra hard dental stone, immersed in nacl disinfectant group 12: type iv extra hard dental stone, sprayed by nacl disinfectant surface hardness evaluation: the surface hardness was evaluated for each 12 test groups at 2 time intervals the first was before the disinfection procedure and the second was after one hour of disinfection. after setting of the stone about 1 h after mixing and pouring of the stone mixture in the ring the first indentation was performed for all groups then disinfection was commenced for all the samples, according to the disinfection regime for each group after the disinfection procedure we wait 1 h then all specimens were tested in brinell hardness tester, with a tungsten carbide sphere of (4mm) in diameter and 40 kg load that was maintained for 30 seconds on the surface of the samples the surface hardness was performed by the brinell hardness test because some researchers found in their study that the brinell hardness test was the most suitable among other surface hardness tests for gypsum products (36). the resulted hardness value represented by the brinell hardness number (bhn) was calculated from the following formula below; where (l) is the load in kilograms, (d) diameter of sphere (4 mm), and (d) diameter of indentation in millimeters:. ( ) 222 mm kg dd-d 2 d l bhn = − = π dimensional accuracy evaluation: a test block certified according to ada specification no. 19 (37) was used to make dental stone samples for evaluation of dimensional accuracy. the test block was engraved with 3 parallel lines, x, y, and z and two cross lines of (cd) and (c´d´), as seen in figure (2). before the fabrication of each specimen, the surface of the test block was cleaned with cotton gauze soaked in alcohol, rinsed with distilled water, and dried. the test block was fixed under the ring (20mm height and 30mm diameter) and the gypsum product was poured with constant vibration into the ring and then covered with a glass slab. two measurements were recorded for each stone sample; the first was before the disinfection procedure (the first measurements were performed after 24 h after mixing and poring of the stone) and the second was after one hour of disinfection. the samples were scanned with a scanner to achieve a digital picture from which the measurement of the distance (cd) (c´d´) was obtained with the computer program corel draw x3 version 13. reproduction of details evaluation: according to the ada specification for detail reproduction of the dental stone test block was used to assess reproduction of details. the test block had a 600 angle groove with a width of 0.05 mm and a cross line groove that passed at a perpendicular angle to the 0.05 mm wide groove. the stone samples were poured, in the rubber ring (20mm height and 30mm diameter) while placed over the test block as previously mentioned; vibration was used during the pouring process of the mixed dental stone. the examination for reproduction of details of the stone samples was randomly conducted by 10 examiners, without magnification, under low angle illumination. the samples made for each gypsum product were examined before and after disinfection. the ansi/ada specification no.25 requires that gypsum products reproduce a line of 0.05mm in width. the samples were scored in relation to scoring system from 1-4. reproduction of a 0.05mm wide line on the test samples was used as j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 11 criteria for surface detail evaluation scoring system as follows: score 1: well-defined, sharp, and continuous. score 2: continuous and clear for more than half the length. score 3: the continuity and clearness was less than half the length. score 4: the ridge failed to be reproduced along the length of the sample. surface porosity evaluation: a total of 60 samples were made for surface porosity evaluation. each stone sample was scanned with a scanner twice; before and after one hour of the disinfection procedures. then, with the use of the program corel draw x3 version 13, a circle was drawn to outline the outer border of the sample. in the center of this circle another circle was drawn with a diameter of 4 mm. surface porosity was assessed by counting the number of pores inside the smaller circle. surface porosity of each stone sample was read twice and an average of the two attempts was obtained for each of stone samples. thus an average was obtained before disinfection and one after. statistical analysis included descriptive statistics and paired sample t-test statistical at a significance level was (s) p< 0.05, (hs) p<0.01, (ns),p>0.05. results the mean and standard deviation of the surface hardness for all tested group are listed in table (1). the results showed no significant difference in the hardness for all groups except type iv extra hard dental stone which showed significant increase in the hardness after disinfection with solo by spraying method table (2). the mean and standard deviation of the surface porosity for each tested group were calculated and listed in table (3). the results showed no significant difference in mean porosity for all types of stone of both disinfection methods except for type iv extra hard when immersed with solo and naocl solution table (4). the mean and standard deviation of the dimensional stability values for all tested groups are shown in table (5). the paired samples t–test showed no significant differences in the dimension of the test samples for all of the test groups after sprayed or immersed in solo and naocl as present in table (6). the results of reproduction of details test revealed that disinfection of dental stone specimens with naocl solution and solo both by spraying and immersion produced insignificant effect on the reproduction of details value as seen in table (7). as showed in the results that all the test samples had the same score, in which the percentage were 100% score 1, no samples registered score (2, 3 or 4). discussion in prosthodontics, objects potentially contaminated with pathogenic microorganisms are transported between dental laboratory and dental clinic. it has been claimed that to avoid cross contamination, specific disinfection measures should be followed. the usual solution to this problem has been to chemically disinfect the casts and the efficacy of such disinfectants has been the subject of several studies (11,38). the dental profession continues to search for improved methods to protect personnel and patients from possible microbial crosscontamination. to date, no single approach exists to accomplish this objective. it is recognized that microorganisms can be transferred to a gypsum cast from a contaminated dental impression. efforts to minimize the amount of microbial contamination vary widely. the most widely used disinfection protocols involve either spray or immersion of dental casts in different chemical disinfectants. in this study naocl disinfectant solution was used because one of the ada recommended disinfectants is chlorine compounds such as (1:10 dilution) of sodium hypochlorite solution. solo disinfectant solution was used because this new product was found by some studies very effective as disinfectant solution for acrylic and soft liner (34). the result of surface hardness showed that an improvement of hardness for most types of dental stone after treatment with the disinfectant solution this may be due to the more crystals will be formed with time as a result of dehydration of the stone from the excess water which allow more calcium sulfate dihydrate crystals to precipitate to anchor the larger crystals so increase the hardness of the stone will occur; while the type iv stone samples showed decrease in surface hardness after sprayed with solo solution this may be due to reaction between disinfectant and stone. in general this finding was in agreement with those of a previous study by syed mohammed et al and kumer et al. who found the decreased hardness in gypsum specimens immersed in disinfectant solutions may have been a result of a reaction between disinfectants and stone, the disinfectant may have reacted with gypsum to produce decreased hardness. the disinfectant did not visibly roughen the impression, but a film of disinfectant could be remained on the material j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 12 even after thorough rinsing with water. this concentrated residual disinfectant may have reacted with gypsum to produce decreased hardness. (11,39,40) on the other hand the treatment with the two disinfectant solutions by the two methods for all tested groups shows no significant difference in hardness after treatment. this in agree with the result of kumer et al who found repeated disinfection of stone casts in naocl and glutaraldehyde solutions showed no significant difference in hardness value (11). the dimensional stability test revealed that some tested groups showed expansion and other groups showed shrinking although both groups were statistically insignificant after treatment with the disinfectant (naocl solution and solo) by spraying and immersion. in 2004 hall et al also found that some stone samples expanded and others shrinked. they could not find any explanation for the results, although the amount of shrinkage was not significantly different (41). none of dental stones underwent expansion or contraction that resulted in statistically significant linear dimensional change. the findings of this study are in general agreement with previous studies. in which there was no significant difference in dimensional change in gypsum products after immersed or spray with the disinfectant. (11,13,41,42) the surface porosity of all the test groups was insignificantly different (table 7) after treatment with the disinfectant solution (naocl and solo) both by spraying and immersion and this could be due to the fact that the disinfectant solutions and the methods employed were safe and no interaction occured between the stone and the solutions, except the type iv extra hard stone samples that were immersed in solo and naocl solution which was statistically significant after treatment. this may be due to interactions that occured between stone and the solution which caused solubility or leaching of some molecules present leaving air bubbles in place or may be due to voids formation on the surface of the dental cast due to air bubbles entrapped during mixing and pouring of the gypsum product. in this research manual spatulation was employed because most of the iraqi dentists mix the gypsum products manually. also, the results of the studies conducted by mazzetto et al. (43) and schelb (44) both showed that the two different techniques of spatulation, manual spatulation and vacuum mechanical spatulation, did not influence the superficial smoothness of the models significantly. detail reproduction is an important characteristic of the plaster, since the correct adaptation of the prosthetic restoration is directly related to the exactitude of the cast. the result of this study showed that the stone samples immersed or sprayed with the solo and naocl disinfection solutions showed no signs of deterioration of surface details. they were in resemblance with the stone samples before disinfection which all had scores 1, all the gypsum products used in this research had the same capacity for surface details reproduction. this was in agreement with rudd et.al.(45) and abass in 2009 (46) , but the results of reproduction of details was in disagreement with abdullah (45) , who found that immersion of dental stone type iii and iv in slurry of naocl solution lead to some deterioration to the dental stone. references 1. marya cm, shukla p, dahiya v, jnaneswar a. current status of disinfection of dental impressions in indian dental colleges: a cause of concern. j infect dev ctries. 2011; 5(11):776-780. 2. the japan prosthodontic society. a guideline for infection control protocol in prosthodontic practice. ann jpn prosthodont soc 2007; 51: 629-689. 3. egusa h, watamoto t, abe k, kobayashi m, kaneda y, ashida s, matsumoto t, yatani h. an analysis of the persistent presence of opportunistic pathogens on patient derived dental impressions and gypsum casts. int j prosthodont 2008; 21: 62-68. 4. rutala wa, weber dj, healthcare infection control practices advisory committee (hicpac). guideline for disinfection and sterilization in healthcare facilities, atlanta: centers for disease control and prevention (cdc); 2008: 20-21, 88-89, 104-105. 5. hiraguchi h, kaketani m, hirose h , yoneyama t. effect of immersion disinfection of alginate impressions in sodium hypochlorite solution on the dimensional changes of stone models. dent mater j 2012; 31(2): 280–286(ivsl) 6. american dental association: infection control recommendations for the dental office and dental laboratory. jam dent assoc 1996;127:672-680 7. watkinson ac. disinfection of impressions in uk dental schools. british dent j 1988; 164:22-23. 8. leung rl, schonfeld se. gypsum casts as a potential source of microbial cross contamination. j prosthet. dent 1983;.49, :210-211, 9. abdelaziz km, combe ec, hodges js. the effect of disinfectants on the properties of dental gypsum. part 2: surfaces properties. j prosthodont. 2002; 11: 234– 240. 10. bal bt, yılmaz h, aydın c et al. antibacterial and antifungal properties of polyether impression materials. j oral sci 2001; 49: 265–270 11. kumar rn, reddy sm, karthigeyan s, rpunithavathy, karthik ks, manikandan r. the effect of repeated immersion of gypsum cast in sodium hypochlorite and glutaraldehyde on its physical properties: an in vitro study. j pharm bioallied sci. 2012 august; 4(suppl 2): s353–s357. j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 13 12. bass ra, plummer kd, anderson ef. the effect of surface disinfectants on a dental cast. j prosthet dent 1992; 67: 723-725. 13. stern ma, johnson gh, toolson lb. an evaluation of dental stones after repeated exposure to spray disinfectant. part 1: abrasion and compressive strength. j prosthet dent 1991; 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255:1887-91. 20. bloomfield sf, smith-burchnell ca, dalgleish ag. evaluation of hypochlorite-releasing disinfectants against the human immunodeficiency virus (hiv). j hospital infection 1990; 15:273-8. 21. bond ww, favero ms, peterson nj, ebert jw. inactivation of hepatitis b virus by intermediate to high level disinfectant chemicals. j clini microbiology 1983; 18:535-8. 22. death je, coates d. effect of ph on sporicidal and microbiocidal activity of buffered mixtures of alcohol and sodium hypochlorite. j clini pathology 1979; 32:148-53. 23. rueggeberg fa, beall fe, kelly nt, schuster gs. sodium hypochlorite disinfection of irreversible hydrocolloid impression material. j prosthet dent 1992; 67:628-31. 24. look jo, clay dj, gong k, messer hh. preliminary results from disinfection of irreversible hydrocolloid impressions. j prosthet dent 1990; 63:701-07. 25. beyerle m,hensley oh. bradley dv jr, schwartz rs, hilton tj. immersion disinfection of irreversible hydrocolloid impressions with sodium hypochlorite. part 1: microbiology. international j prosthodont 1994; 7:234-8. 26. mc neill mrj, coulter wa, hussey dl. disinfection of irreversible hydrocolloid impressions: a comparative study. int j prosthodont 1992; 5:563-7. 27. breault lg, paul jr, hondrum so et al. die stone disinfection: incorporation of sodium hypochlorite. j prosthodont 1998; 7: 13–16. 28. sarma ac, neiman r. a study of the effect of disinfectant chemicals on physical properties of die stone. quintessence int 1990; 21: 53–59. 29. berko ry. effect of madacide disinfectant solution on some of physical and mechanical properties of dental stone. a master thesis, university of baghdad 2001. 30. tarik em, al-ameer ss, the effect of storage time and disinfection method on the activity of some dental stone disinfectants. j bagh coll dent 2005; 17(3): 812 31. michael j, khamas am, al-azzawi s.compressive strength and surface roughness of die stone cast after repeated disinfection with sodium hypochlorite solution. j bagh college dent 2010; 22(3), 37. 32. lucas mg, arioli-filho jn, nogueira ss, batista ad, & pereira rp. effect of incorporation of disinfectant solutions on setting time, linear dimensional stability, and detail reproduction in dental stone casts. j prosthodont 2009; 18: 521–526. 33. abdullah ma. surface detail, compressive strength, and dimensional accuracy of gypsum casts after repeated immersion in hypochlorite solution. j prosthet dent 2006;95:462-8 34. abass sm, nassif ra, khalaf bs. influence of solo disinfectant on some properties of different denture lining materials. j bagh coll dent 2012; 24(3):36-41. 35. council on dental therapeutics council on prosthetic services and dental laboratory relations. guidelines for infection control in the dental office and the commercial dental laboratory. jada 1985:110; 96972. 36. johansson eg, erhardson s, wictorin l. influence of stone mixing agents, impression materials and lubricants on surface hardness and dimension of a dental stone die material. acta odont scand 1975; 33: 17-25. 37. american dental association. council on dental materials and devices. revised american dental association specification no.19 for non-aqueous, dental elastomeric dental impression materials. jada 1977; 94:733-41. 38. patrick naylor w. infection control in fixed prosthodontics. dent clin n am 1992; 36:809-31. 39. hussain sm, tredwin cj, nesbit m, moles dr. the effect of disinfection on iireversible hydrocolloid and type iii gypsum casts. j prosthodont restor dent 2006; 11:52-4. 40. vandewalie ks, charlton dg, schwartz rs, reagan se, koeppen rg. immersion disinfection of irreversible hydrocolloid impressions with sodium hypochlorite. part ii: effect on gypsum. int j prosthodont 1994; 7:315-22. 41. hall bd, muñoz-viveros ca, naylor wp, jenny sy, effects of a chemical disinfectant on the physical properties of dental stones. int j prosthodont 2004; 17: 65–71. 42. duke p, moore bk, haug sp, andres cj. study of the physical properties of type iv gypsum, resincontaining, and epoxy die materials. j prosthet dent 2000; 83: 466–73. 43. mazzetto mo, maia campos g, roselino rb. [medical rugosity (ra) of the surface of stone models from alginate impressions using two processes: manual spatulation and vacuum mechanical spatulation]. rev odontol univ saopaulo.1990;4(3):228-33. 44. schelb e. using a syringe to make void-free casts from elastomeric impressions. j prosthet dent 1988; 60:121-2. 45. rudd kd, morrow rm, brawn ce, powell jm. rahe aj. comparision of effects of tap water and slurry water on gypsum casts. j prosthet dent 1970; 24(5):563-70 j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 14 46. abass sm. effect of microwave disinfection on some properties of gypsum products. j bagh coll dent 2009; 21(3):47-52. figure 1. grouping of the samples cd cd x y z figure 2. diagram of die for dimensional accuracy 240 samples 60 samples dimensional accuracy 60 samples surface hardness 20 type iv extra hard 10 samples for solo 5 for immersion 5 for spray 10 samples for naocl 20 type iii 20 type iv 60 samples surface porosity 60 samples reproduction of details j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 15 table 1: mean and standard deviation for surface hardness of the tested groups type of the stone type of the disinfection method of disinfection before treatment after treatment mean std. devi. mean std. devi. type iii solo spray 10.79 1.40 11.22 1.93 immersion 12.05 .28 12.73 1.36 naocl spray 12.12 a .00 12.12 a .00 immersion 11.97 1.10 12.11 1.58 type iv solo spray 16.41 1.60 16.35 1.06 immersion 15.85 1.84 16.62 2.97 naocl spray 12.40 .63 12.97 .77 immersion 18.13 1.93 18.75 1.04 type iv extra hard solo spray 23.63 1.87 26.53 1.89 immersion 21.70 1.25 22.82 3.08 naocl spray 23.39 2.62 24.07 2.69 immersion 20.94 2.22 21.14 1.53 table 2: paired sample t-test surface hardness of the tested groups type of the stone type of the disinfection method of disinfection t sig. type iii solo spray -1.06 .348 immersion -1.23 .284 naocl spray immersion -.20 .845 type iv solo spray .10 .922 immersion -1.06 .348 naocl spray -1.0 0 .374 immersion -1.53 .199 type iv extra hard solo spray -3.90 .017 immersion -1.16 .307 naocl spray -1.62 .179 immersion -.335 .754 a. the correlation and t cannot be computed because the standard error of the difference is 0. table 3: mean and standard deviation for surface porosity of the tested groups type of the stone type of the disinfection method of disinfection before treatment after treatment mean std. devi. mean std. devi. type iii solo spray 7.20a 1.09 7.20 a 1.09 immersion 7.80 1.09 8.00 1.41 naocl spray 4.80 3.27 5.40 2.60 immersion 7.00 5.38 7.60 5.02 type iv solo spray 3.00 2.12 4.40 2.30 immersion 8.80 a 3.03 8.80 a 3.03 naocl spray 5.40 3.28 5.60 2.07 immersion 6.60 4.92 7.60 4.15 type iv extra hard solo spray 5.40 1.34 8.0 1.41 immersion 9.60 3.97 12.20 3.03 naocl spray 7.20 5.06 8.80 4.38 immersion 4.60 1.94 11.20 2.58 j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 16 table 4: paired sample t-test surface porosity of the tested groups type of the stone type of the disinfection method of disinfection t sig. type iii solo spray immersion -1.00 .36 naocl spray -1.50 .20 immersion -1.50 .20 type iv solo spray -1.60 .18 immersion naocl spray -.20 .84 immersion -1.58 .18 type iv extra hard solo spray -2.52 .06 immersion -3.83 .01 naocl spray -2.35 .07 immersion -8.12 .001 a. the correlation and t cannot be computed because the standard error of the difference is 0. table 5: mean and standard deviation for dimensional accuracy of the tested groups type of the stone type of the disinfection method of disinfection before treatment after treatment mean std. devi. mean std. devi. type iii solo spray 19.76 .055 19.73 .049 immersion 19.68 .018 19.72 .036 naocl spray 19.724 .061 19.66 .04604 immersion 19.74 .023 19.66 .074 type iv solo spray 19.65 .075 19.69 .087 immersion 19.69 .053 19.67 .052 naocl spray 19.71 .038 19.72 .023 immersion 19.71 .079 19.7 .02 type iv extra hard solo spray 19.71 .071 19.71 .02 immersion 19.71 .048 19.70 .033 naocl spray 19.66 .035 19.67 .069 immersion 19.70 .043 19.66 .028 table 6: paired sample t-test of dimensional accuracy of the tested groups type of the stone type of the disinfection method of disinfection t sig type iii solo spray .72 .50 immersion -2.56 .06 naocl spray 1.32 .25 immersion 2.60 .05 type iv solo spray -.85 .44 immersion .72 .50 naocl spray -.40 .70 immersion .39 .71 type iv extra hard solo spray .00 1 immersion .14 .89 naocl spray -.13 .90 immersion 1.51 .20 j bagh college dentistry vol. 25(2), june 2013 the effect of solo restorative dentistry 17 table 7: score of the reproduction of details type of the stone type of the disinfection method of disinfection scores type iii solo spray score 1 immersion score 1 naocl spray score 1 immersion score 1 type iv solo spray score 1 immersion score 1 naocl spray score 1 immersion score 1 type iv extra hard solo spray score 1 immersion score 1 naocl spray score 1 immersion score 1 taif.doc j bagh college dentistry vol. 28(1), march 2016 an evaluation oral and maxillofacial surgery and periodontics 127 an evaluation of the effectiveness of coenzyme q10 gel in management of patients with chronic periodontitis (ii inter group comparison) taif m. salih, b.d.s. (1) maha sh. mahmood, b.d.s., m.sc. (2) abstract background: anti-oxidants are used as supplements to counteract the over production of free radicals in periodontal disease.co-q10 functions as an intercellular antioxidant by acting as a primary scavenger of free radicals (frs) and reactive oxygen species (ros), this study aimed to evaluate the effect of intra pocket application of perio q gel (coenzyme q10) alone and as adjunct to scaling and root planing on the periodontal clinical parameters in the treatment of patients with chronic periodontitis and compare the better improvement on the clinical periodontal parameters among different treatment modalities at 3 and 6 weeks. materials and methods: a total of 323 sites with pocket depth (5-8) mm in patients with chronic periodontitis were randomly divided into three groups. the gel group, 111 sites were treated with intra-pocket application of perio q gel alone. in the combination group, 106 sites were treated with scaling and root planning (srp) plus intrapocket application of perio q gel, in scaling and root planing group, 106 sites were treated with scaling and root planing alone. clinical periodontal parameters such as plaque index (pi), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd), relative attachment level (ral) were assessed at first visit, 3weeks and 6weeks. results: inter-group analysis, showed significant reduction in the clinical parameters ppd and ral of combination group in comparison to srp group. conclusion: better improvement of the clinical periodontal parameters had been achieved by using the gel in combination with scaling and root planing instead of using scaling and root planing only. keyword: chronic periodontitis, antioxidants, coenzyme q10, perio q gel (j bagh coll dentistry 2016; 28(1):127-132). introduction inflammation represents the response of the organism to a noxious stimulus, whether mechanical, chemical, or infectious. it is a localized protective response elicited by injury or destruction of tissues which serves to destroy, dilute, or wall off both the injurious agent and the injured tissue. whether acute or chronic, inflammation is dependent upon regulated humoral and cellular responses, and the molecules considered to mediate inflammation at one time or another are legion (1). periodontitis is an immunoinflammatory disease process resulting from the interaction of a bacterial attack and host inflammatory response, causing inflammation of the supporting tissues of the teeth leading to tissue destruction and tooth loss (2). coenzyme q10 (co-q10; ubiquinone) is a compound which is naturally found in every cell of the human body. it derives its name from the ubiquitous presence in nature and quinone structure, which is similar to that of vitamin k. it is a fat-soluble compound which forms an important link in the electron transport system of mitochondria (3). (1) master student. department of periodontics, college of dentistry, university of baghdad. (2) professor, department of periodontics, college of dentistry, university of baghdad. true deficiency states are rare but often present with severe health consequences. numerous disease processes which are linked to low levels of co-q10 can benefit from co-q10 supplementation including cardiovascular disease, parkinson's disease, muscular dystrophy, breast and other cancers, diabetes mellitus, male infertility, acquired immunodeficiency syndrome (aids), asthma, thyroid disorders, and periodontal disease. co-q10 has been the topic of research interest since 1970s, which experienced a series of trails depicting its anti-inflammatory, anti-oxidant, and immune modulatory activities (4). this research is part ii of the original one and it s aimed to compare the better improvement among different treatment modalities of patients suffering from chronic periodontitis with a 6 weeks follow up study. materials and methods the total patients number were 15, both genders, with an age range (35-55), had chronic periodontitis. the aims and purposes of the study were well explained to the patients so they participated voluntarily in the period from april to the beginning of july 2014. a total of 323 sites of the probing depth (5-8) mm were included in the study. j bagh college dentistry vol. 28(1), march 2016 an evaluation oral and maxillofacial surgery and periodontics 128 each patient mouth splited into three quadrants, each quadrant should have at least 4 pocket sites of (5-8) mm depth. the selected sites were divided into three groups according to the different treatment modalities: gel group: these sites treated with intra-pocket application of perio q gel only without any deep scaling or root planing. combination group: these sites treated by both: intra-pocket application of perio q gel with scaling and root planing. scaling and root planning group: these sites treated with scaling and root planing alone. periodontal examinations were performed before and after three and six weeks after the beginning of the experiment. periodontal assessments were performed using theplaque index (pli) (5), gingival index (gi) (6), bleeding on probing (bop) (7), probing pocket depth (ppd) (8) and relative attachment level (ral). occlusal stent was constructed for each patient. for the three groups, the initial visit (1st day) included patient selection, supra gingival scaling, alginate impression, motivation and instruction. gel group 111 sites received intra pocket application of perio q gel only. combination group: 106 sites in this group received deep scaling and root planing, then after one hour, the patient examined if there was no blood oozing, then the gel applied. if not, the patient was referred to the next day. scaling and root planning group: received scaling and root planing only. data collected after 3weeks and 6weeks. data obtained after treatment was compared with the initial values. details of statistical analysis regarding mean±sd of plaque index (pli), gingival index (gi), probing pocket depth (ppd) and relative attachment level (ral) and median for bleeding on probing of each group of treatment modality were mentioned in the first part of the research (9) .analysis of variance test (anova) one-way, lsd test , t –test and mann whitney u test were used where indicated. the level of significance was 0.05. results inter-group comparison: table 1 showed the comparison of the clinical periodontal parameters pli, gi, ppd and ral at each visits. regarding pli and gi indices, there were no significant differences among three groups in the three visits. regarding ppd and ral, it was showed that there were significant differences among three groups in the 1st and2nd visits and a non-significant difference in the 3rd visit. table 2 showed the details of inter-groups comparison of mean differences for the clinical periodontal parameters (ppd and ral) between each pairs of groups. probing pocket depth in first visit showed non-significant difference between gel and combination groups but showed significant differences between gel and scaling and root planing groups, as well as between combination and scaling and root planing. second visit showed non-significant difference between gel and combination groups but showed significant difference between gel and scaling and root planing groups and between combination and scaling and root planing. ral in first visit showed non-significant difference between gel and combination groups but showed significant difference between gel and scaling and root planing groups, and between combination and scaling and root planing. second visit showed non-significant difference between gel and combination groups but showed significant difference between gel and scaling and root planing groups, and between combination and scaling and root planing groups. table 3 showed that in the third visit a significant difference was found between combination and scaling and root planing in both clinical periodontal parameters (ppd and ral). table 4 showed non-significant differences between each two groups of bleeding on probing periodontal parameter score 0 and1 in the three visits. j bagh college dentistry vol. 28(1), march 2016 an evaluation oral and maxillofacial surgery and periodontics 129 table 1: mean and standard deviation values of the clinical periodontal parameters (pli, gi, ppd and ral) in inter-groups comparison among the three groups by anova test variables visits groups descriptive statistics groups' difference d.f.= 44 mean s.d. min. max. f-test p-value pli 1st gel 1.80 0.33 1 2.1 1.414 0.254 (ns) combination 1.83 0.23 1.5 2 scaling and rp 1.94 0.13 1.57 2 2nd gel 1.33 0.37 0.83 2 0.366 0.696 (ns) combination 1.41 0.31 1 2 scaling and rp 1.42 0.19 1 1.6 3rd gel 0.98 0.29 0.5 1.6 0.957 0.392 (ns) combination 1.02 0.20 0.6 1.4 scaling and rp 1.09 0.18 0.7 1.4 gi 1st gel 1.99 0.05 1.83 2.09 0.076 0.927 (ns) combination 1.98 0.06 1.75 2 scaling and rp 1.98 0.13 1.57 2.2 2nd gel 1.59 0.17 1.25 2 0.291 0.749 (ns) combination 1.56 0.17 1.3 1.8 scaling and rp 1.54 0.22 1.25 2 3rd gel 1.25 0.24 1 1.63 0.447 0.634 (ns) combination 1.20 0.23 1 1.75 scaling and rp 1.18 0.17 1 1.42 ppd 1st gel 6.75 0.68 5.8 7.8 3.532 0.038 (s) combination 6.20 0.62 5.5 7.75 scaling and rp 6.40 0.66 5.2 7.28 2nd gel 6.23 0.61 5.5 7.3 4.130 0.023 (s) combination 5.67 0.60 5.16 7.25 scaling and rp 6.10 0.61 4.6 6.7 3rd gel 5.59 0.62 4.6 6.7 2.907 0.066 (ns) combination 5.19 0.71 4.25 6.87 scaling and rp 5.75 0.62 4.2 6.25 ral 1st gel 7.74 0.68 6.8 8.9 3.525 0.038 (s) combination 7.20 0.62 6.5 8.89 scaling and rp 7.50 0.66 6.2 8.4 2nd gel 7.23 0.61 6.5 8.4 4.221 0.021 (s) combination 6.67 0.60 6.16 8.4 scaling and rp 7.05 0.61 5.6 7.8 3rd gel 6.58 0.62 5.6 7.8 2.946 0.063 (ns) combination 5.75 0.71 5.25 7.98 scaling and rp 6.19 0.61 5.2 7.3 table 2: inter groups comparison of ppd and ral between each pair of the study groups using lsd test at 1st and 2nd visits variables groups mean difference p-value 1st visit ppd gel combination 0.001 0.998 (ns) scaling and rp 0.551 0.026 (s) combination scaling and rp 0.551 0.026 (s) 2nd visit ppd gel combination 0.011 0.959 (ns) scaling and rp 0.556 0.016 (s) combination scaling and rp 0.545 0.018 (s) 1st visit ral gel combination -0.026 0.914 (ns) scaling and rp 0.539 0.030 (s) combination scaling and rp 0.565 0.023 (s) 2nd visit ral gel combination 0.004 0.986 (ns) scaling and rp 0.559 0.015 (s) combination scaling and rp 0.555 0.016 (s) j bagh college dentistry vol. 28(1), march 2016 an evaluation oral and maxillofacial surgery and periodontics 130 table 3: inter-groups comparison between each two groups of the clinical periodontal parameters (pli, gi, ppd and ral) and the significance of differences by t-test at each visit variables visits groups comparison (d.f.=28) t-test p-value pli 1st gel x combination -0.210 0.835 (ns) gel x scaling and rp -1.522 0.139 (ns) combination x scaling and rp -1.733 0.094 (ns) 2nd gel x combination -0.594 0.557 (ns) gel x scaling and rp -0.802 0.429 (ns) combination x scaling and rp -0.135 0.893 (ns) 3rd gel x combination -0.456 0.652 (ns) gel x scaling and rp -1.298 0.205 (ns) combination x scaling and rp -1.046 0.304 (ns) gi 1st gel x combination 0.533 0.598 (ns) gel x scaling and rp 0.285 0.777 (ns) combination x scaling and rp -0.037 0.971 (ns) 2nd gel x combination 0.410 0.685 (ns) gel x scaling and rp 0.733 0.470 (ns) combination x scaling and rp 0.374 0.711 (ns) 3rd gel x combination 0.593 0.558 (ns) gel x scaling and rp 0.964 0.343 (ns) combination x scaling and rp 0.288 0.775 (ns) ppd 1st gel x combination 0.003 0.998 (ns) gel x scaling and rp 2.247 0.033 (s) combination x scaling and rp 2.344 0.026 (s) 2nd gel x combination 0.051 0.959 (ns) gel x scaling and rp 2.496 0.019 (s) combination x scaling and rp 2.472 0.020 (s) 3rd gel x combination -0.659 0.515 (ns) gel x scaling and rp 1.751 0.091 (ns) combination x scaling and rp 2.290 0.030 (s) ral 1st gel x combination -0.109 0.914 (ns) gel x scaling and rp 2.190 0.037 (s) combination x scaling and rp 2.401 0.023 (s) 2nd gel x combination 0.018 0.986 (ns) gel x scaling and rp 2.512 0.018 (s) combination x scaling and rp 2.516 0.018 (s) 3rd gel x combination -0.692 0.495 (ns) gel x scaling and rp 1.740 0.093 (ns) combination x scaling and rp 2.316 0.028 (s) discussion intergroups comparison: plaque index among these three groups showed non-significant differences at three visits that indicated the patient maintained oral hygiene to the three quadrants that involved in this study equally, so no differences between the three groups. this agrees with chaudhry et al. (10) and disagrees with other studies (4,11-13), gingival index and bleeding on probing showed non-significant differences among these three groups at the three visits. this indicated that the three treatment modalities resulted in reduction of the gingival inflammation ,in addition to that the coenzyme q10 have an effect with significant reduction of motile rods and spirochetes (14), also mechanical therapy have an effect that prevent bacteria from easily colonizing so the three treatment modalities have an effect of preventing bacteria. this result agrees with chaudhry et al (10) and disagree with other studies (4,1113). probing pocket depth and relative attachment level in third visit showed significant differences between combination group and scaling and rootplaning group with a better improvement of the combination group. this could be due to the potential additive effect of coenzyme q10.this was in agreement with these studies (10,4,11,13). the improved clinical periodontal parameters in this study could also possibly be credited by improvement in immunity in combating periodontal insult. j bagh college dentistry vol. 28(1), march 2016 an evaluation oral and maxillofacial surgery and periodontics 131 table 4: inter-groups comparison between each two groups of the clinical periodontal parameter (bleeding on probing) scores by mann-whitney u test at each visit bop visits groups comparison mann-whitney u test p-value 0 1st gel x combination 112 0.962 (ns) gel x scaling and rp 112 0.962 (ns) combination x scaling and rp 112 0.962 (ns) 2nd gel x combination 79.5 0.167 (ns) gel x scaling and rp 81 0.189 (ns) combination x scaling and rp 101.5 0.639 (ns) 3rd gel x combination 87 0.288 (ns) gel x scaling and rp 85 0.252 (ns) combination x scaling and rp 110.5 0.933 (ns) 1 1st gel x combination 103 0.692 (ns) gel x scaling and rp 111 0.950 (ns) combination x scaling and rp 107 0.817 (ns) 2nd gel x combination 106 0.786 (ns) gel x scaling and rp 107 0.818 (ns) combination x scaling and rp 103 0.686 (ns) 3rd gel x combination 103 0.680 (ns) gel x scaling and rp 95 0.449 (ns) combination x scaling and rp 111 0.947 (ns) all the results of this study disagree with the studies that mentioned the coq10 have no place in periodontal treatment (15,16). problems there were certain problems encountered during the present study. the intra-pocket placement of the gel was difficult due to unfavorable thixotropic properties which is a time-dependent shear thinning property. certain gels or fluids that are thick (viscous) under static conditions will flow (become thin, less viscous) over time when shaken, agitated, or otherwise stressed (time dependent viscosity) (17), although the pocket was filled up thoroughly from its base to the gingival margin. other problem was bioavailability of the gel was not known (bioavailability is defined as the proportion of an orally administered substance that reaches the systemic circulation (18)). it has been found that improving the bioavailability of coq10 can be achieved through: a) reduction in particle size (19). b) coq10 in oil suspension (20). c) novel forms of coq10 with increased water solubility (21). other problem was the substantively of the gel (pertaining to the capacity of an oral antimicrobial agent to continue its therapeutic activity for a prolonged period of time) (22), as it was neither a sustained release nor a controlled release formulation; therefore, it may have had a short wash out period. in this study, the gingiva visibly regained the normal color and cohesion. the shallowing of periodontal pockets could also been noted, the decrease in gingival bleeding while brushing teeth, pale gingiva and the subsidence of pain in ailments. the patient that maintained good oral hygiene gave more significant differences than the others did. as a conclusion; inter-group comparison between srp group and combination group in ppd and ral showed significantly reduction of combination group than srp group. the results from scaling and root planing group almost showed similar improvement in clinical periodontal parameters with perio-q gel alone group. the benefit is almost using of q10 alone was proved to reveal good results which has an advantage in patients who cannot be treated by srp (systemic diseases). references 1. battino m, bullon p, wilson m, newman h. oxidative injury and inflammatory periodontal diseases: the challenge of anti-oxidants to free radicals and reactive oxygen species. crit rev oral biol med 1999; 10: 458–76. 2. prakash s, sunitha j, hans m. role of coenzyme q10 as an antioxidant and bioenergizer in periodontal diseases. indian j pharmacol 2010; 42: 334–7. 3. ashtaputre vand limaye m. local drug delivery in periodontics: a tactical entreaty. j research in pharmaceutical sci 2014); 2(1): 6-11 4. chatterjee a, kandwal a, singh n, singh a. evaluation of co-q10 antigingivitis effect on plaque induced gingivitis: a randomized controlled j bagh college dentistry vol. 28(1), march 2016 an evaluation oral and maxillofacial surgery and periodontics 132 clinical trial, j indian soc periodontol 2012; 16(4): 539–42. 5. silness j, loe h. periodontal disease in pregnancy. ii. correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22:112-35. 6. löe h. the gingival index, the plaque index and the retention index systems. j periodontol 1967; 38(6): 610-16. (ivsl). 7. carranza n, takei k. carranza's clinical periodontology. 11th ed. 2012. 8. lindhe j, karring t, lang n. clinical periodontology and implant dentistry. 3rd ed. copenhagen: munksgaard; 1998. 9. salih tm, mahmood msh. evaluation of the effectiveness of coenzyme q10 gel in management of patients with chronic periodontitis (i intra group comparison). j bagh coll dentistry 2015; 27(2): 10. chaudhry s, vaish s, dodwad v, arora a. natural antioxidant :coenzyme q10 (perio q)tm in management of chronic periodontities: a clinical study .int j dent health sci 2014; 1(4):475-84 11. hans m, prakash s, gupta s. clinical evaluation of topical application of perio-q gel (coenzyme q10) in chronic periodontitis patients. j indian soc periodontol 2012; 16(2): 193–9 12. zaki nm. site-specific delivery of the nutraceutical coq10 for periodontal therapy .international journal of pharmacy and pharmaceutical sciences int j pharm pharm sci 2012; 4: 717-23. 13. sale st, parvez h, yeltiwar rk, vivekanandan g, pundir aj, jain p. a comparative evaluation of topical and intrasulcular application of coenzyme q10 (perio q™) gel in chronic periodontitis patients: a clinical study. j indian soc periodontol 2014; 18(4): 461–5. 14. denny n, chapple il, matthews jb. antioxidant and anti-inflammatory effects of coenzyme q10: a preliminary study. j dent res 1999; 78:543. 15. lister re. coenzyme q10 and periodontal disease. br dent j 1995; 179(6): 200-1 16. watts tl. coenzyme q10 and periodontal treatment: is there any beneficial effect? br dent j 1995; 178(6): 209-13. 17. chanson h, aoki s, hoque a. bubble entrainment and dispersion in plunging jet flows: freshwater versus seawater. j coastal res 2006; 22(3): 664–77 18. weis m, mortensen sa, rassing mr, et al. bioavailability of four oral coenzyme q10 formulations in healthy volunteers. mol aspects med 1994; 15: s273-s280. 19. joshi ss, sawant sv, shedge a, halpner ad. comparative bioavailability of two novel coenzyme q10 preparations in humans. int j clin pharmacol ther 2003; 41: 42-8. 20. westesen k, siekmann b. particles with modified physicochemical properties, their preparation and uses. 2001. 21. kagan d, madhavi d. a study on the bioavailability of a novel sustained-release coenzyme q10-ßcyclodextrin complex. j int med 2010; 11:109-13. 22. elworthy a, greenman j, doherty fm, newcombe rg, addy m. the substantivity of a number of oral hygiene products determined by the duration of effects on salivary bacteria. j periodontol 1996; 67(6): 572-6. mayada f.doc j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 17 evaluation of tissue displacement in posterior palatal seal area with different impression techniques with varying palatal forms mayada q. abdul khafoor, b.d.s., m.sc. (1) rafah a. ibrahim, b.d.s., m.sc. (2) ilham h. al-abdulla, b.d.s., m.sc. (3) abstract background: this study was designed to measure the displacement pattern of posterior palatal seal (pps) area in different forms of the palate and with different impression techniques. materials and method: this study was used to measure the displacement pattern of (pps)in different palatal shapes by using different impression materials korrecta wax no.4,green compound and design of house for pps for each palatal forms by using a 3d scanner of cad/cam and measuring the distance between 2 points in pps area by using caural threw. result: the results show highly significant differences between these techniques and the control group (impression with light body) conclusion: the physiological impression technique of pps with korecta wax no.4 and design of house for each palatal forms give less displacement than the physiological impression with green compound. keywords: maxillary complete dentures, posterior palatal seal. (j bagh coll dentistry 2013; 25(4):17-25). introduction the security of maxillary complete denture depends primarily on close peripheral contact between the denture and its supporting tissue. 1 the pps area has been defined as an area that is located at the junction of hard and soft palate and which is composed of a soft tissue, along which pressure will be applied by a denture, within the physiological limits of the tissue, to aid in denture retention2. a well fitting and retentive maxillary complete denture requires : a well fitting surface, a peripheral border compatible with the muscles and tissues which make up the muco-buccal and muco-labial space, so that a peripheral seal is created by soft tissues draping over them and finally by a pps3 . brian and robert discussed different materials for achieving a pps of a maxillary complete denture which include arbitrary scraping of the cast prior to denture processing, the physiological impression technique and the selective pressure impression technique.4 laney and gonzales5 discussed the need for knowledge of the oral cavity anatomy so that the static surface of the denture base can be balanced against one dynamic tissue surface. in the pps area, the tissues are displaceable and the degree of displacement can be sensitized by palpation with “t” burnisher6, by closing both nostrils of the patient and make him blow gently7 (1)assistant professor, department of prosthodontics, college of dentistry, university of baghdad. (2)lecturer, department of prosthodontics’, college of dentistry, university of baghdad. (3) assistant lecturer, department of prosthodontics, college of dentistry, university of kerbala. or by noticing the vibrating line when the patient says “ah” 8. the anterior and posterior vibrating lines are considered as two separate lines of flexion 9. also by measuring the tissue with various impression materials, a functional or physiological pps can be made as early as the maxillary final impression10. the posterior border of the maxillary denture extends into and through the pterygo-maxillary notches and along the vibrating line. the pterygomaxillary notch is bounded posteriorly by the hamular process of the sphenoid bone and the lateral pterygyoid plate and anteriorly by the maxillary tuberosity 11. the tensor palati muscle wraps around the hamular process and attaches to the posterior nasal spine to form the palatal aponeurosis12. the pterygo-mandibular ligament extends from the hamular process to the lingula of the mandible. pendleton’s13 anatomic dissections and histological and clinical examination have shown this area to vary greatly in size, form and character. the shape of palatal vault is related to the activity of the soft palate .the flat vault has the least movable soft palate and the widest area of displaceable tissue. in contrast, the high vault or “v” shaped palate often has a soft palate virtually at right angles to the hard palate and is extremely mobile. thus, the area of tissue displaceability is very narrow .the intermediate palatal vault lies between these two extremes so that house classified the palatal form to class i flat palatal vault in the hard palate and class iii a high vault and class ii intermediate between them14,15. nikoukari16measured the dimension and j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 18 displacement of pps in different palatal shapes, he used different impression materials and found that the tissue displacement caused by zoe was less than that caused by other materials. this study was designed to detect the displacement pattern of pps in different palatal shapes with different impression techniques. materials and methods a. selection of patient: twenty one (21) patients with different palatal form (deep, medium and flat), were selected visually by a team of prosthodontics to determine the palatal form , from prosthodontic clinic , college of dentistry , university of baghdad ,seven for each group. the age ranges between 60-70 years without any posterior under cut. b. impression techniques: the primary impressions were made with alginate. then impressions were poured with stone (zeta, selensor, industriazingardi, italy) three closed fit special tray and one spaced special tray were fabricated for different impression techniques. i. final impression (control group) by using spaced special tray and taking impression with light body (elastic impression material ) ,then poured with stone .the cast considered as control was marked 1,as shown in fig (1). ii. physiological pps impression technique by using korecta wax no.4 and another one by using low –fusing modeling compound with the following steps: 1. the posterior border of the special tray should be trimmed and adjusted one to two mm distal to the vibrating line. 2. border molding should be done and the final impression was taken by using zinc oxide eugenol (zoe) paste. 3. the vibrating line should be marked in the mouth with indelible pencil by asking the patient to say “ah” with nose blowing and using the fovea palatine in locating the vibrating line (anterior and posterior vibrating line) and transferring the location to the zoe impression17. 4. kerr korecta wax no.4 and low fusing modeling compound were used to record the pps by painting it on pps area of impression. 5. the impression should be returned to patient mouth and held it in place for about 3 minutes. patient is guided to tip its head forward to approximately 30o from the vertical position and place his tongue against tray handle 18-20. 6. impression is removed and excess material removed with bard-parker blades. then impression is reseated for 5 to 8 minutes. 7. impression is carefully beaded and boxed and poured with stone .these 2 castes were marked 2 with korrecta wax and 3with modeling compound as shown in fig (2) and (3). iii. ordinary impression technique with zoe 1. the same steps 1, 2 and 3 which were done in the previous technique are done here. 2. the impression then was poured with stone and the master cast was marked 4. 3. scraping cast 4 for incorporation of pps to carve certain design by using no.4 round bur with lacron carver21 .the patients were classified (visually) into groups according to house’s classification of palatal form. group a (deep palatal form) a1=control group with light body impression. a2=physiological impression of pps with kerr korrecta wax no.4 a3=physiological impression of pps with low – fusing molding compound. a4=scraping casts no.4 in pps area according to housesingle bead 1mm depth and width22. group b (intermediate palatal form) b1=control group with light body impression. b2= physiological impression of pps with kerr korrecta wax no.4 b3=physiological impression of pps with low – fusing molding compound. b4=scraping casts no.4in pps area according to house –modified butterfly 2-3mm wide and 1mm depth. group c (flat palatal form) c1=control group with light body impression. c2=physiological impression of pps with kerr korrecta wax no.4. c3=physiological impression of pps with lowfusing modeling compound. c4=scraping casts no.4 in pps area according to house –modified butterfly 3-4mm wide and 1mmdepth22. c. preparing working casts i. on the working casts (no.1) indicate the incisive papilla and the position of fovea palatine on the midline, 1/3distance between these two points indicated as point 1 near fovea palatine on midline. indicate the crest of hamular notch on the cast and put a point on the end of hamular notch on the ridge on both sides, which are indicated as points 3 and 7. j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 19 draw a straight line between points 3 and 7 and put point no.5 on the midline .half the distance between point 3 and 5, put point 4. half the distance between points 5 and 7 put point 6. put a point on the location of fovea palatine on the midline indicate as point 9, draw a horizontal straight line from point 9 on the center of crest of ridge on both sides and indicated as points 2 and 8, half the distance between points 9 and 2, put point 10 ,half the distance between points 9 and 8, put point 11 . also half the distance between points 9 and 10 put point 12 and half the distance between 9 and 11 put point 13 .these points 10, 11, 12, 13 are used to measure the depth of pps area .as shown in fig (4). ii. a splint was made on the control casts no.1 by using cold cure acrylic23 (ivoclar).fig (5), these points were transferred on the cast to the splint by indelible pencil and a hole was made on the splint by using round bur no.4. then this splint was used on the other casts no.2, 3 and 4 and the location of these points should be transferred to the casts fig (6). iii. for measuring the width of tissue displacement in pps area ,scanner of these casts should be made by using three dimension (laser denta) of cad/cam (computer-aided design/computer-aided manufacture) 3 dimension scanner to take a picture with its original dimensions of the casts as shown in fig. (7 and 8) ,these pictures were directly evaluated and measured through data analyzed in the computer by using caural threw program to measure the distance between points 1-3, 1-4, 1-5, 1-6, and 1-7 and distance between points 2-9 and 8-9 to show the displacement pattern in post dam area for each impression technique in millimeters 24,25. iv. measuring the depth of pps at different points. the acrylic splint which is used for transferring the points was put on the cast no. 1 (control) and pins were put on both sides of points 2 and 8 to fix the split on the cast. then by using a pin like (reamer which is used for endodontic treatment) with stopper to determine the length of pins which were inserted inside points 10, 11, 12 and 13 to measure the depth of pps in this area and then should be measured by vernier .this procedure should be repeated on casts no. 2, 3 and 4 to measure the depth of pps for all the patients for each group as shown in fig 9. results 1. measurement of width of pps area: group a (deep palatal vault) the mean values, sd and anova of the statistical analysis for the data of the distance between the 2 points for group a were shown in table 1. whereas the result of lsd (multiple comparison) between the four groups (a1, a2, a3 and a4) were shown in table 2. the results show that there were highly significant differences in data between the groups a1, a2, a3 and a4 except for the data of distance 1-5 between a1 and a4 which show that there were non significant differences. the mean differences for each distance for group a2,a3 and a4 with the control a1 show that the least tissue displacement were in group a4 (design of house single bead )followed by a2 (physiological impression with korecta wax)also show the least displacement while a3(low-fusing compound )which show more displacement. group b (intermediate palatal vault). the mean values, sd and anova of statistical analysis for the data of distance between 2 points for group b were shown in table 3.whereas the result of lsd between the 4 groups b1, b2, b3 and b4 were shown in table 4. the results explained that there were very highly significant differences between the data of each group (b1, b2, b3 and b4). the mean differences for the data of each distance between the groups ( b2, b3, and b4) with the control group b1 show the least displacement were in groups b2 (korrecta wax ) and b4 (design of house).while the most displacement was in group b3 (low-fusing compound ). group c (flat palatal vault) the mean values, sd and anova of statistical analysis for the data of distance between 2 points for group c were shown in table 5. whereas the result of lsd between the four groups is shown in table 6. the result explained that there were highly significant differences between the four groups c1, c2, c3 and c4 for each distance except that there was a non significant difference for data of distance 1-4 points between c2 and c3 groups. the mean difference between groups c2, c3 and c4 with c1 for the result shows that the least displacement were in groups c2 (korrecta wax) and c4 (design of house) and more displacement was in group c3 (low-fusing compound). 2. measurements of the depth of points in pps area: tables 7 , 8 , 9 , 10 , 11 and 12 give readings for deep , medium and flat palates respectively j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 20 with anova and lsd multiple comparison , which show highly significant differences between these groups. the results indicated that the tissue displacement caused by elastic materials (control group) was less than that caused by other materials in all three types of palatal shape. the casts in which the pps area was obtained with modeling compound had the highest displacement readings; this result was found for all three types of palatal shapes; while the measurements obtained from korecta wax and design of house were between those readings of control group and modeling compound. discussion the pps area has been defined as an area that is located at the junction of hard and soft palat and which is composed of a soft tissue, along which pressure will be applied by a denture within the physiological limits of the tissue to aid in denture retention2. the results of all groups indicated that the tissue displacement caused by kerr korecta wax no.4 was less than the green compound tracing impression technique this due to the fact that this wax is a fluid and the mouth temperature wax is more preferable for this procedure .it flows sufficiently at mouth temperature to avoid displacement of tissues, and as the wax continues to exhibit its property of flow in the mouth ,it permits the tissues in the area of pps to rebound ,establishing a degree of displacement that is physiologically acceptable18 .this result agrees with nikoukari 16.,who stated that casts in which the pps area obtained with modeling compound had a higher displacement than that obtained by korrecta wax no.4. the scraping method according to house classification of palatal vault of pps for each group showed that the best result (the lowest displacement ) approximately nearer to the result of kerr korecta wax .this result occurred because in group c (flat palatal vault )the vibrating line was further posteriorly, resulting in the broadest pps area ,so that the design of house is 3-4 mm butterfly .where as in the deep vault ( group a), the posterior extension of pps area was less than in group b (medium vault )so the design of house in deep vault single bead is 1 mm in depth and width. this result agrees with the observation of swenson and terkla who observe that the direction of vibrating line differ with the shape of the palate .the higher the vault the more abrupt and forward is the vibrating line. in a mouth with a flat vault, the vibrating line is usually further posteriorly and has a gradual curvature affording a broader pps area 26,27. as conclusions; one of the most important problems that associated with poor retention of the maxillary complete denture is a faulty pps it can be concluded from this study the following: 1the physiological impression with korecta wax no.4 for pps area gives less tissue displacement than other materials. 2the palatal form aids in the selection of the type of posterior palatal seal needed .the house design of pps for each type of palatal forms gives less displacement in this area. references 1. lamb dj, samara r, johnson a. palatal discrepancies and post dam. j oral rehabil 2005; 32:188-92 2. ronald le, forrest rs. the posterior palatal seal .a review. aust dent j 1980; 25(4):197-200. 3. avants we. comparison of the retention of complete denture bases having different types of posterior palatal seal. j prosthet dent 1973; 29(50): 484-93 4. brain w, robert f. accurate location of posterior palatal seal area on the maxillary complete denture cast. j prosthet dent 2006; 96(6): 454-5. 5. laney wr, gonzales jb. the maxillary denture: its palatal relief and posterior palatal seal. j am dent assoc 1967; 75: 1182-7. 6. bylicky hs. variable approaches in obtaining a posterior palatal seal: description of technique. nyj dent 1966; 36: 280-2. 7. heart well gm, rhn ao. syllabus of complete dentures. 1st ed. philadelphia: lea and febiger publishers; 1968. 8. hardy ir, kapur kk. posterior border seal, it’s rational and importance. j prosthet dent 1958; 8(3): 386-7. 9. vernie af, chitrev, aras m. a study to determine whether the anterior and posterior vibrating lines can be distinguished as two separate lines of flexion by unbiased observer: a pilot study. indian j dent researcher 2008; 19(4): 335-9 [ivsl]. 10. house mm. full dentures techniques study club no.1, 1950. 11. edwards lf, boucher co. anatomy of the mouth in relation to complete denture. jada 1942; 29(3): 33143. 12. boucher co, hickey jc, zarb ga. prosthetic treatment for edentulous patients. 11th ed. st. louis. the c.v mosby company. 1997. pp.118-20. 13. pendleton ec. influence of biological factors in retention of artificial dentures. jada 1936; 23(7): 1233-51. 14. sudhakara vm, sudhakara um, karthik ks, vdita sm. a review on diagnosis and treatment planning for completely edentulous patients. jiads 2010; 1(2):1522. 15. watt dm, mac greagor ar. designing complete dentures. philadelphia: w.b. saunders company; 1976. pp. 83-6. 16. nikoukari h. a study of posterior palatal seal with varying palatal forms. j prosthet dent 1975; 34: 60513. j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 21 17. behnoush r, vicki cp. current concept for determining the posterior palatal seal in complete denture. j prosth dent 2003; 12(4): 265-70. 18. gerald sw. establishing the posterior palatal seal during the final impression procedure: a functional approach. j am dent assoc 1977; 94; 505-10. 19. silverman si. dimension and displacement patterns of posterior palatal seal. j prosth dent 1971; 25: 470. 20. aaron yu-jen and terry e. donovan.engaging the physiological pps with the frame work of a maxillary over denture. j pros dent 2009; 101: 214-5 21. mohammed aa, et al. comparing required dislodging forces between different types of posterior palatal seal. must dent j 2006; 3(1): 97-101. 22. sudhakara vm, karthik k.s. a review on posterior palatal seal. jiads 2010; 1(1): 16-21. 23. aljudy hj. measurement of the extension ridges tissue displacement on the cast obtained from various impression techniques. college of dentistry – university of baghdad 2001. 24. reem a. surface area measurement of upper dental arch with different final impressions. j bagh coll dentistry 2013; 25(2): 36-41. 25. andrea e, albert m. accuracy of complete – arch dental impressions: a new method of measuring trueness and precision. j.p.d 2013; 109: 121-8. 26. swenson mg, terklal g. complete denture. 6th ed. st. louis: the c.v. mosby company: 1970. pp. 65-70, 372-6. 27. mayada q. a comparison of the retention of complete denture base having different types of posterior palatal seal with different palatal forms. j bagh coll dentistry 2012; 24(2): 11-5. table 1: means, standard deviation (sd) and anova of each distance between 2 points of group a (deep palatal vault) width of pps in (mm) distance between 2 points a1 control a2 korrectawa a3 tracing compound a4 single bead sig. mean sd mean sd mean sd mean sd 1-3 31.21 .0283 32.68 .01582 33.6 .00708 32.3 .0079 .000 1-4 27.24 .01225 30.2 .0083 31.1 .01581 29.25 .0077 .000 1-5 22.86 .0100 23.18 .00707 23.6 .01581 22.86 .0592 .000 1-6 27.24 .0173 32.95 .00707 33.3 .01582 28.24 .01732 .000 1-7 31.84 .0100 33.52 .01581 34.56 .0083 32.82 .0158 .000 9-2 21.6 .0123 24.0 .012 24.3 .0273 22.78 .00708 .000 9-8 22.0 .0255 24.53 .00707 24.63 .02236 23.11 .01000 .000 table 2: lsd multiple comparisons between the groups of each distance between 2 points for group a( for width of pps ) groups 1-3 1-4 1-5 1-6 1-7 9-2 9-8 mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig a1 a2 -1.47 .000 -2.96 .000 -.32 .000 -5.71 .000 -1.68 .000 -2.4 .000 -2.53 .000 a1 a3 -2.39 .000 -3.86 .000 -.74 .000 -6.06 .000 -2.72 .000 -2.7 .000 -2.63 .000 a1 a4 -1.09 .000 -2.01 .000 .00 1.00 -1.0 .000 -.98 .000 -1.18 .000 -1.11 .000 a2 a3 -.92 .000 -.90 .000 -.42 .000 -.35 .000 -1.04 .000 -.30 .000 -.10 .000 a2 a4 .38 .000 .95 .000 .320 .000 4.71 .000 .70 .000 1.22 .000 1.42 .000 a3 a4 1.3 .000 1.85 .000 .74 .000 5.06 .000 1.74 .000 1.52 .000 1.52 .000 the mean differences are significant at the .05 level table 3: means, standard deviation (sd) and anova of each distance between 2 points of group b (intermediate palatal vault) width of pps in (mm) distance between 2 points b 1 control b2 korrecta wax b3 tracing compound b4 butterfly 2-3mm sig. mean sd mean sd mean sd mean sd 1-3 30.68 .0282 31.1 .1000 32.66 .01581 30.9 .00707 .000 1-4 23.4 .00707 23.85 .03803 23.95 .0308 24.12 .0187 .000 1-5 18.22 .0158 18.44 .0169 19.02 .01000 18.32 .00707 .000 1-6 23.38 .0173 23.6 .00707 23.95 .01581 24.12 .01581 .000 1-7 30.56 .010101 31.32 .0123 31.93 .01225 30.77 .0123 .000 9-2 22.11 .01225 24.08 .01581 24.98 .00837 23.02 .01000 .000 9-8 24.23 .0255 26.2 .00707 26.45 .02236 25.99 .01000 .000 j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 22 table 4: lsd multiple comparisons between the groups of each distance between 2 points for group b (for width of pps in (mm)) groups 1-3 1-4 1-5 1-6 1-7 2-9 9-8 mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig b1 b2 -.42 .000 -.45 .000 -.22 .000 -.22 .000 -.76 .000 -1.97 .000 -1.97 .000 b1 b3 -1.98 .000 -.55 .000 -.80 .000 -.57 .000 -1.37 .000 -2.87 .000 -2.22 .000 b1 b4 -.22 .000 -.72 .000 -.10 .000 -.74 .000 -.21 .000 -.91 .000 -1.76 .000 b2 b3 -1.56 .000 -.10 .000 -.58 .000 -.35 .000 -.61 .000 -.902 .000 -.25 .000 b2 b4 .20 .000 -.27 .000 .12 .000 -.52 .000 .55 .000 1.06 .000 .21 .000 b3 b4 1.76 .000 -.17 .000 .70 .000 -.17 .000 1.16 .000 1.962 .000 .46 .000 the mean difference is significant at the .05 level. table 5: means, standard deviation (sd) and anova of each distance between 2 points of group c (flat palatal vault ) for width of pps in (mm) distance between 2 points c 1 control c2 korrecta wax c3 tracing compound c4 butterfly 3-4mm sig. mean sd mean sd mean sd mean sd 1-3 33.38 .01581 34.28 .01581 35.06 .02074 33.98 .01225 .000 1-4 25.1 .07071 26.74 .03162 26.78 .01581 26.57 .05148 .000 1-5 18.50 .02236 18.8 .01871 18.95 .02915 18.6 .03536 .000 1-6 24.72 .01582 25.1 .00707 25.92 .01581 25.32 .01581 .000 1-7 35.07 .03391 35.79 .01225 36.28 .01581 35.95 .03162 .000 9-2 25.32 .01581 26.33 .01671 26.92 .01591 26.8 .02345 .000 9-8 27.71 .0133 28.63 .0123 28.93 .0273 28.42 .0122 .000 table 6: lsd multiple comparison between the groups of each distance between 2 points for group c (for width of pps in (mm)) groups 1-3 1-4 1-5 1-6 1-7 2-9 9-8 mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig mean diff sig. c1 c2 -.90 .000 -1.64 .000 -.30 .000 -.38 .000 -.72 .000 -1.01 .000 -.92 .000 c1 c3 -1.68 .000 -1.68 .000 -.45 .000 -1.2 .000 -1.21 .000 -1.6 .000 -1.22 .000 c1 c4 -.60 .000 -1.47 .000 -.10 .000 -.60 .000 -.88 .000 -1.48 .000 -.71 .000 c2 c3 -.784 .000 -.04 .199 -.150 .000 -.82 .000 -.49 .000 -.59 .000 -.30 .000 c2 c4 .30 .000 .17 .000 .20 .000 -.22 .000 -.16 .000 -.47 .000 .21 .000 c3 c4 1.084 .000 .21 .000 .35 .000 .60 .000 .33 .000 .12 .000 .51 .000 the mean difference is significant at the .05 level. table 7: means, standard deviation and anova of depth of points in pps area in (mm) of group a (deep palatal vault) points a1 control a2 korecta wax a3 tracing comp. a4 single beed anova sig. mean sd mean sd mean sd mean sd 10 5 .30 7.6 .37 9.5 .30 6.5 .38 .000 11 5 .36 7.3 .58 8.9 .74 6.8 .6 .000 12 6.2 .2 7.9 .6 8.2 .3 7.5 .32 .000 13 6.5 .38 8.2 .31 9 .41 7.6 39 .000 table 8: lsd multiple comparison between the groups of group a (deep palatal vault) for depth of pps groups 10 point 11 12 13 mean diff. sig. mean diff. sig. mean diff. sig . mean diff. sig. a1 a2 -2.6 .000 -2.3 .000 -1.7 .000 -1.7 .000 a1 a3 -4.5 .000 -3.9 .000 -2.0 .000 -2.5 .000 a1 a4 -1.5 .000 -1.88 .000 -1.3 .000 -1.1 .000 a2 a3 -1.9 .000 -1.5 .001 -.30 .269 -.80 .004 a2 a4 1.1 .000 .44 .265 .4 .146 .6 .023 a3 a4 3.0 .000 2.02 .000 .70 .017 1.4 .000 the mean differences are significant at the .05 level j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 23 table 9: means, standard deviation and anova of depth of points in pps area in (mm)of group b (intermediate palatal vault ) points b1 control b2 korecta wax b3 tracing comp. b4 butterfly 2-3 mm anova sig. mean sd mean sd mean sd mean sd 10 5.7 .18 7.9 .53 8.9 .6 7.2 .46 .000 11 5.5 .33 7.5 .53 8.9 .6 6.9 .34 .000 12 6.2 .67 7.9 .25 8.7 .3 7.7 .18 .000 13 6.2 .38 7.8 .3 8.9 .25 7.8 .29 .000 table 10: lsd multiple comparisons between the groups of group b (intermediate palatal vault) for depth of pps groups 10 point 11 12 13 mean diff. sig. mean diff. sig. mean diff. sig . mean diff. sig. b1 b2 -2.2 .000 -2.0 .000 -1.7 .000 -1.5 .000 b1 b3 -3,2 .000 -3.4 .000 -2.5 .000 -2.6 .000 b1 b4 -1.5 .000 -1.4 .000 -1.5 .000 -1.52 .000 b2 b3 -1.0 .005 -1.4 .000 -.80 .006 -1.1 .000 b2 b4 .7 .038 .60 .068 .20 .444 .000 1.0 b3 b4 1.7 .000 2.0 .000 1.0 .001 1.1 .000 the mean differences are significant at the .05 level table 11: mean, standard deviation and anova of depth of points in pps area in (mm) of group c (flat palatal vault) points c1 control c2 korecta wax c3 tracing comp. c4 butterfly 3-4mm anova sig. mean sd mean sd mean sd mean sd 10 5.0 .30 7.2 .29 7.8 .36 6.5 .38 .000 11 5.3 .18 7.3 .14 7.9 .122 6.6 .46 .000 12 5.4 .10 7.0 .37 7.4 .32 6.3 .44 .000 13 5.5 .12 7.0 .37 7.3 .17 6.4 .41 .000 table 12: lsd multiple comparisons between the groups of group c (flat palatal vault) for depth of pps groups 10 point 11 12 13 mean diff. sig. mean diff. sig. mean diff. sig. mean diff. sig. c1 c2 -2.2 .000 -2.0 .000 -1.6 .000 -1.5 .000 c1 c3 -2.8 .000 -2.6 .000 -2.0 .000 -1.8 .000 c1 c4 -1.5 .000 -1.3 .000 -.9 .001 -.9 .000 c2 c3 -.6 .013 -.6 .003 -.4 .079 -.3 .133 c2 c4 .7 .005 .70 .001 .70 .005 .6 .006 c3 c4 1.3 .000 1.3 .000 1.1 .000 .9 .000 the mean differences are significant at the .05 level j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 24 fig. 1: final impression with fig. 2: final impression with korecta wax spaced special tray by using light body fig. 3: final impression with modeling compound fig. 4: selection of 13 point for measuring tissue displacement j bagh college dentistry vol. 25(4), december 2013 evaluation of tissue restorative dentistry 25 fig. 6: casts no. 2, 3 and 4 after transferring the points by the splint fig. 5: acrylic splint of cast no. 1 fig. 7: 3d three dimension scanner laser dent of cad/cam fig. 8: 3d three dimensions image of stone cast fig. 9: using reamer on the splint to measure the depth of pps65 16. karrar f.doc j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 94 immunohistochemical expression of basic fibroblast growth factor-2 and heparanase in oral squamous cell carcinoma karrar n. shareef, b.d.s. (1) ahlam h. majeed, b.d.s., m.sc. (2) abstract back ground: the aim of this study was to evaluate the expression of fibroblast growth factor-2 and heparanase in oral squamous cell carcinoma, and to correlate the two studied marker with each other and with clinicopathologicalfinding including grade, stage. methods: sections of 30 formalin-fixed paraffin embedded blocks specimens of oral squamous cell carcinoma were immunostained to assess the expression of fibroblast growth factor-2 and heparanse in oral squamous cell carcinoma cases. results: the expression of fibroblast growth factor-2 and heparanase were positive in all oral squamous cell carcinoma cases (100%). the positive expression of fibroblast growth factor-2 was significantly correlated with tumor site (p=0.016),and clinical presentation(p-value =0.003).the positive expression of heparanse was significantly correlated with tumor grade(p-value =0.002) .on other hand there was non-significant correlation between fibroblast growth factor-2 ,heparanase and other clinicopathological parameters .statistically significant correlation was found between the expressions of fibroblast growth factor-2 and heparanase(p-value= 0.021). conclusion: the fibroblast growth factor-2 and heparanase positive expression was noted in all cases of oral squamous cell carcinomasignifying their important role in the angiogenesis and lymph node metastasis in oral squamous cell carcinoma, furthermore they cooperate in promoting vascularization, suggesting that fibroblast growth factor-2 and heparanase are promising targets for the development of anticancer therapeutics for head and neck malignancies. key words: oral squamous cell carcinoma, fgf-2, heparanase. (j bagh coll dentistry 2013; 25(1):94-98). introduction oral cancer is a major public health issue worldwide; it remains a highly lethal and disfiguring disease. it makes the whole dental team with important obligations, challenges, and a real opportunity to save lives (1). oral squamous cell carcinoma account for about 95% of all malignant neoplasm's in the mouth (2). it remains a lethal disease in over 50% of the cases diagnosed annually, due mostly to late detection of advanced stage cancer. oscc characterized by a high degree of local invasiveness and a high rate of metastasis to cervical lymph nodes, but a low rate of metastasis to distant organs. death as a result of cancer is often the result of local recurrence or regional and/or systemic metastasis (3). the expansion or extension of existing vasculature, is necessary to deliver oxygen and nutrients to ischemic area in the wounds and solid tumors (4) . angiogenesis is a crucial step in the successful growth, invasion and metastasis of tumors, without which tumors will not grow more than 1-2 mm3 in size (5,6). (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. tumor angiogenesis' plays an important role in the growth, invasion and metastasis of (oscc) (7,8). it’s regulated by numerous pro angiogenetic factors and antiangiogenetic factors by interstitial cell and tumor cell itself (9). fibroblast growth factor-2(fgf-2) is a powerful pro angiogenetic factor (10). it's the prototypic member of a family containing at least 23 structurally-related polypeptide growth factors. the expression of fgf-2 augmented at sites of chronic inflammation, after tissue injury, and in different types of human cancer (11). fgf2 over expression plays a key role in the progression of oscc, correlated with lymph node metastasis (12). the activity of fgf-2 is mediated by binding to heparan sulfate proteoglycans (hspg) and to high affinity, cell surface receptor tyrosine kinases.the role of hspg in modulating fgf-2 activity has been described at many levels. the generation of stable, high affinity fgf-2/fgfr complexes is probably the major mechanism leading to hspg-dependent fgf-2 activity. in addition, fgf-2 has been localized to the extracellular matrix (ecm) associated with hspg (6,7). heparanase is an end glycosidase which cleaves heparan sulfate (hs) and hence participates in degradation and remodeling of the (ecm). heparanase is preferentially expressed in human tumors and its over-expression in tumor cells confers an invasive phenotype in experimental animals. this enzyme also releases j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 95 angiogenic factors from the ecm and thereby induces an angiogenic response in vivo.many evidences suggest that the expression of heparanase in the tumor closely relates with thepotential for tumor invasion, angiogenesis and metastasisin most tumors examined (13). materials and methods the sample: thesample of this study included thirty formalin-fixed, paraffin-embedded tissue blocks, which have been diagnosed as oscc, dated from (2000 till 2012). the study samples were obtained from al-shaheed ghazi hospital/ medical city /baghdad; the archives of the department of oral and maxillofacial pathology/ college of dentistry/ university of baghdad; and private laboratories in baghdad.demographic and clinicopathological datain regard topatient's age, sex, clinical presentation, site of the tumor, grading and stagingobtained from the case sheets.allhematoxylin and eosin stained tissue sections were reviewed by two specialized pathologists,andthe best sections and those representing the original tumor site from each specimen were selected. another 4µm thick sections for each case were cut and mounted on positively charged slides for immunohistochemical staining with monoclonal antibodiesfibroblast growth factor-2(us. biological)andheparanase(us.biological).positi ve and negative tissue controls were obtained according antibodies manufacturer’s datasheet and added to each test run. evaluation of immunohistochemistry results: immunohistochemical signal specificity was demonstrated by the absence of immunostaining in the negative control slides and its presence in recommended positive controls.for fgf-2tumor cells with clear brown cytoplasmic staining pattern wereconsideredpositive, and membranous or membranous and cytoplasmic immunoreactivities were considered positive for heparanase. immunohistochemical stained oscc sections were studied by light microscope under 10xobjective. in each tissue section, five representative fields (areas showed well preserved oscc islands in which the reaction was clearly positive) were selected for fgf-2 and heparanse monoclonal antibodies immunostaining evaluation, with an average of 1000 tumor cell per case and 200 tumor cells per field. only the number of cells that were positive for fgf-2 and positive for heparanse was quantified by counting at least one thousand cells in representative five fields at 40x objective in each case. the extent of staining was scored using the following scale: 0 = no staining (negative), 1 =staining of 1–25% of cells (weak positive), 2 = staining of 26–75% of tumor cells(moderate positive), 3 =staining of 76– 100% of tumor cells(strong positive)(14). statistical analysis: the studied parameters were scored and considered as categorical data thus theypresented as count and percentage. the relationship between categories was tested bychi-square test. spearman's rho correlation was applied to assess the linear association between fgf-2 and heparanse. the level of significance was 0.05 (two-sided) in allstatistical testing. results immunohistochemical staining with fgf-2 monoclonal antibody showed that fgf-2 expression was positive in all examined oscc specimens.positive fgf-2 immunostaining was detected as brown cytoplasmic staining of the tumor cells as shown infigure(1 a, b, c).regarding degree of expression as illustrated in table (1) which reveals that 3 cases (10.0%) showed weak positive expression, 9 cases (30.0%)showedmoderate positive expressionand 18 cases (60.0%) showed strong positive \ expression. immunohistochemical staining with heparanase monoclonal antibody showed that heparanase expression was positive in all examined oscc specimens.positive heparanase immunostaining was detected as brown for both cytoplasm and cell membrane in tumor cellsshown in figure (2 a, b, c).regarding degree of expression as illustrated in table (4) which reveals that 4 cases (13.3%) showed weak positive expression, 11cases (36.7%)showed moderate positiveexpression and 15 cases (50.0%)showed strong positiveexpression.the positive expression of fibroblast growth factor-2 was significantly correlated with tumor site (p=0.016),and clinical presentation (p value=0.003).the positive expression of heparanse was significantly correlated with tumor grade(p-value =0.002) table (6).on other hand there was non-significant correlation between fibroblast growth factor-2,heparanase and other clinicopathological parameters tables (2, 3, 5).statistically significant correlation was found between the expressions of fibroblast growth factor-2 and heparanase (p-value= 0.021) table (7). j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 96 table 1: fgf-2 ihc expression in oscc cases % no. fgf-2 score* 10.0% 3 1 30.0% 9 2 60.0% 18 3 100% 30 total *1(weak expression),2 (moderate expression), 3 (strong expression). table 2: correlation of fgf-2 with tumor stage stage total i ii iii iv fgf-2 score* 1 1 0 2 0 3 33.4% .0% 66.6% .0% 100.0% 2 2 1 2 4 9 22.2% 11.1% 22.2% 44.5% 100.0% 3 6 2 4 6 18 33.3% 11.2% 22.2% 33.3% 100.0% total 9 3 8 10 30 30.0% 10.0% 26.7% 33.3% 100.0% value df p.value pearson chi-square 5.106 9 .825 table 3: correlation of fgf-2 with tumor grade grade total well moderate poor fgf-2 score* 1 0 2 1 3 .0% 66.6% 33.4% 100.0% 2 0 8 1 9 .0% 88.9% 11.1% 100.0% 3 7 9 2 18 38.9% 50.0% 11.1% 100.0% total 7 19 4 30 23.3% 63.3% 13.3% 100.0% value df p.value pearson chi-square 8.618 6 .196 figure 1: (a) positive immunostaining of fgf-2in well differentiated oscc(40x) (b) positiveimmunostaining of fgf-2 in moderate differentiated oscc(40x) (c)positive immunostaining of fgf-2 in poorly differentiated oscc(40x) table 4: heparanase ihc expression in oscc cases % no. heparanasescore* 13.3% 4 1 36.7% 11 2 50.0% 15 3 100% 30 total *1(weak expression),2 (moderate expression), 3 (strong expression). table 5: correlation of heparanase with tumor stage stage total i ii iii iv heparanase score* 1 1 0 1 2 4 25.0% .0% 25.0% 50.0% 100.0% 2 3 1 3 4 11 27.3% 9.1% 27.3% 36.3% 100.0% 3 5 2 4 4 15 33.3% 13.3% 26.7% 26.7% 100.0% total 9 3 8 10 30 30.0% 10.0% 26.7% 33.3% 100.0% value df p.value pearson chi-square 3.036 9 .963 j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 97 table 6: correlation of heparanase with tumor grade grade total well moderate poor heparanase score* 1 0 2 2 4 .0% 50.0% 50.0% 100.0% 2 1 10 0 11 9.1% 90.9% .0% 100.0% 3 6 7 2 15 40.0% 46.7% 13.3% 100.0% total 7 19 4 30 23.3% 63.4% 13.3% 100.0% value df p.value pearson chi-square 20.345 6 .002 table 7: the correlation of fgf-2 &heparanase ihc expressions fgf-2 heparanase fgf-2 pearson correlation 1 19.591 sig. (2-tailed) .021 * heparanase n 30 30 pearson correlation 19.591 1 sig. (2-tailed) .021 * n 30 30 figure 2: (a) positiveimmunostaining of heparanasein well differentiated oscc (40x) (b) positive immunostaining of heparanasein moderate differentiated oscc (40x) (c) positive immunostaining of heparanase in poorly differentiated oscc (40x) discussion the results of this study showed positive fgf-2 expression in all oscc cases with (60.0%) of cases showed strong positive score. the present finding was in agreement with previous reports in oscc (15-17). this suggest that fgf-2 may be involved in mitoses seen in squamous cells of oral squamous cell carcinoma (15). it has been demonstrated that fgf-2 promotes the production of cancer cell proteinases and enhances their invasive ability, this explain that fgf-2 produced by cancer cells,and could activates the cancer cells themselves and/or the fibroblasts for the invasion and growth of the cancer (17).the present study showed positive heparanase expression in all oscc cases, which also revealed that (50.0%) showed strong positive score ,these finding was in agreement withprevious reports in oscc (18) .the key role of heparanase in tumorigenesis and the existing evidence for only one endogenous mammalian heparansulphate degrading endoglycosidase (19), as well as the expression of heparanase even by a few tumor cells may be sufficient to promote dissemination of single tumor cells into adjacent tissues and lead to formation of local metastases (20) .in agreement with the role of the heparanase in releasing fgf2 from the ecm ,the results of the present study revealed that both fgf-2 and heparanase showed similar pattern of expression, they were highly correlated by pearson chi square with significant correlation between either proteins expression was found (p-value=.021). this result agree withprevious reports (21) that found heparanase mrna and fgf-2 mrna are associated with higher tumor mvd in oscc.it have revealed that heparanase degradation of cell surface hs can augment fgf-2 activity, j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 98 depending on the heparanase concentrations used to alter cell surface hs. fgf-2 binding and signaling require hs sequence-specific interactions. depending on the extent of hs degradation, hs sequences, which bind to either fgf-2 or fgfr, could be removed or cryptic sites could be revealed, angiogenesis is dependent multiple components that can be affected by heparanase in the ecm provide binding sites for angiogenic factors such as fgf-2 and vascular endothelial growth factor. cell surface hspg acts as growth factor and adhesion receptors on tumor cells and vascular endothelial cells. modifying the hs may affect tumorigenicityby modifying the responsiveness of multiple receptors to the extracellular environment (22),(23). in conclusion both heparanase and fgf-2 might contribute in angiogenesis and metastasis in oscc and they cooperate in promoting vascularization. these findings are contribute to our understanding of head and neck tumor biology, suggesting that fgf-2 and heparanase are the promising target for the development of anticancer therapeutics for head and neck malignancies. references 1. federation dentaire internationale fdi statement: oral cancer. 1999; fdi world 8(1):24. 2. vermorken jb, remenar e, van herpen c, gorlia t, mesia r, degardin m. cisplatin fluorouracil and docetaxel in unresectable head and neck cancer. n engl j med 2007; 357:1695-1704. 3. warnakulasuriya s. global epidemiology of oral and oropharyngeal cancer. oral oncol 2009; 45:309–316. 4. carmeliet p, jain rk. angiogenesis in cancer and other diseases. j nature 2000; 407: 249 e257. 5. shang zj, li jr. expression of endothelial nitric oxide synthase and vascular endothelial growth factor in oral squamous cell carcinoma: its correlation with angiogenesis and disease progression. j oral pathology & medicine 2005; 34(3): 134. 6. johnstone s, logan rm. the role of vascular endothelial growth factor (vegf) in oral dysplasia and oral squamous cell carcinoma. oral oncology 2006; 42(4): 337-42. 7. feng hc, song yf. the relationship between tumorassociated macrophages and lymphatic metastasis in oral squamous cell carcinoma. j clin stomatol (chinese) 2003; 19:135-7. 8. zhuo xl, feng hc, song yf. expression of surviving and its relationship with angiogenesis in oral squamous cell carcinoma. j clin stomatol (chinese) 2004; 20: 207-9. 9. wu h' deng, zd, chen de. the partial purification of angiogenesis factor of human osteosarcoma. chinesegemran j clinoncol 2002; 1:94-97. 10. kos m, dabrowsky a. tumor's angiogenesisthe function of vegf and b fgf in colorectal cancer. ann univ mariae curie slododowska 2002; 57:55661. 11. presta m, dell ’era p, mitola s, et al. fibroblast growth factor/ fibroblast growth factor receptor system in angiogenesis. cytokine growth factor rev 2005; 16: 159. 12. zhuo xl, song yf. expression of basic fibroblast growth factor and relationship with angiogenesis in oral squamos cell carcinoma. j pract stomatol (chinese) 2005; 21:303-306. 13. netailan michael elkin, israel vlodavsky regulation, function and clinical significance of heparanase in cancer metastasis and angiogenesis. the international journal of biochemistry & cell biology 2006; 38(12): 2018-39. 14. davidson b, vintman l, zcharia e, bedrossian c, berner a, ilan n, vlodavsky i, reich r, nielsen s. heparanase and basic fibroblast growth factor are coexpressed in malignant mesothelioma clinical & experimental metastasis. kluwer academic publishers netherlands 2004; 21: 469-76. 15. wakulich c, boeters lj, tom dd, wysocki gp. immunohistochemical localization of growth factors fibroblast growth factor–1 and fibroblast growth factor–2 and receptors fibroblast growth factor receptor–2 and fibroblast growth factor receptor–3 in normal oral epithelium, epithelial dysplasias, and squamous cell carcinoma. oral surg oral med oral pathol oral radiol endod 2002; 93: 573-9. 16. begum s, zhang y, shintani t, toratani s, denry sato, tetsuji okamoto: immunohistochemical expression of heparin-binding protein 17/ fibroblast growth factor-binding protein-1 (hbp17/fgfbp-1) as an angiogenic factor in head and neck tumorigenesis. oncology reports 2006; 17: 591-6. 17. hase t, shuichi kawashiri, akira tanaka, shinichi nozaki, natsuyo noguchi, hiromitsu nakaya, kiyomasa nakagawa, koroku. correlation of basic fibroblast growth factor expression with the invasion and the prognosis of oral squamous cell carcinoma. j oral pathol med 2006; 35: 136–9. 18. ali dr. immunohistochemical expression of cyclooxygenase-2 and heparanase enzymes in oral squamous cell carcinoma. a master thesis in oral pathology, department of oral diagnosis, college of dentistry, university of baghdad, 2010. 19. rohloff j, zinke j, schoppmeyer k, tannapfel a, witzigmann h, mossner j, wittekind c, caca k. heparanase expression is a prognostic indicator for postoperative survival in pancreatic adenocarcinoma. br j cancer 2002; 86: 1270-5. 20. beckhove p., burkhard m. helmke, yvonne ziouta, et al. heparanase expression at the invasion front of human head and neck cancers and correlation with poor prognosis. clin cancer research 2005; i:10. 1158/1078-0432. 21. chen z, zheng x, feng h. the expression and significance of hparanase and bfgf in oral squamous cell carcinoma. chinese-german j. of clinical oncology 2009; 8(1): 46-9. 22. kato m, wang h, kainulainen v, fitzgerald ml, ledbetter s, ornitz dm, bernfield m. physiological degradation converts the soluble syndecan-1 ectodomain from an inhibitor to a potent activator of fgf-2. nat med 1998; 4: 691-7. 23. liu d, shriver z, venkataraman g, el shabrawi y, sasisekharan r. tumor cell surface heparan sulfate as cryptic promoters or inhibitors of tumor growth and metastasis. proc natl acad sci usa 2002; 99: 568-73. dania.docx j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 17 the effect of pores in dual nano hydroxyapatite coating on thermally oxidized commercial pure titanium: mechanical and histological evaluation dania fawzi mahmood, b.d.s.(1) salah a. mohammed, b.d.s., m.sc. (2) abstract background:in this study,tio2 layer was thermally grown as a diffusion barrier on cp ti substrate prior to electrophoretic deposition of ha coatings, to improve the coating’s compatibility also macro and micro pores in nano hydroxyapatite dual coatings were created and their effect on the bond strength between the bone and implant was evaluated. materials and methods: electrophoretic deposition technique (epd) was used to obtain coatings for each one of four types of hydroxyapatite(ha)on cp ti screws (micro ha, nano ha, dual nano ha with micro pores, dual nano ha with macro pores) where carbon particles used as fugitive material to be removed by thermal treatment to create porosity.for examination of the changes occurred on the substrate, sem, spm and xrd used, coatings characterized by xrd, sem and interfacial shear strength measurements. results:the results mentioned the formation of rutilenano tio2 with, sem showed that the size of pores in ha coatings corresponded to the size of carbon particles. statistical analysis of the removal torque tests showed highest means of the single nano ha coating at 2 and 4 weeks implantation intervals. histological analysisrevealed a faster reaction of bone and higher osteoblasts activity towards thermally oxidized cp ti implants coated with single nano ha coating. conclusion:carbon particles as a fugitive material within nano ha coat produced porosity.presence of pores 1µ in nano ha coats did not achieve highest removal torque values nor highest osteoblasts activity in 2 and 4 weeks implantation intervals. keywords:titanium, thermal oxidization, nano hydroxyapatite, coatings, porosity. (j bagh coll dentistry 2016; 28(1):17-25). introduction one of the major issues with hydroxyapatite coating on a metallic substrate is certain level of porosity in the hydroxyapatite films can be achieved using electrophoretic deposition but with limits where no macro pores are evident, only small pores up to 1 μm observed in the coating. similar surface morphology of the nanohydroxyapatite(1,2)and bioglass® coatings(3) formed by electrophoretic deposition followed by sintering was reported.but the necessity of porosity in bone regeneration has been shown by many studies(4,5). pores are necessary for bone tissue formation because they allow migration and proliferation of osteobalsts and mesenchymal cells, as well as vascularization(6). in addition, a porous structure improves mechanical interlocking between the implant biomaterial and the surrounding natural bone, providing greater mechanical stability at this critical interface(7). thermal treatment is one of the many techniques described(8)to produce porosity in scaffolds used for bone regeneration by extruding fugitive materials from thermoplastic ceramics to produce a 3directional macroporous structure. the production of porous tubes was performed by means of electrophoretic deposition for use in biomedical application. (1)master student, department of prosthetic dentistry, college of dentistry, university of baghdad. (2)assistant professor, department of prosthetic dentistry, college of dentistry, university of baghdad. by means of the hydrothermal process, the mixing of carbon nanotubes and hydroxyapatite was obtained. the hydroxyapatite porous tubes processed with electrophoretic deposition (dc 60v) had a thickness of 310 µ after sintering (1200°c, for 60 min). after the sintering process, porous crack free hydroxyapatite micro tubes were obtained. the experiments conducted reveal that the hydroxyapatite-multi wall carbon nano tubes combination enables the production of complexshaped ceramics using the electrophoretic deposition process(9). materials and methods in vitro commercial available cp ti grade 2 substrate, micro and nano ha powders were used. 1. substrate thermal oxidization: mirror polished cp ti substrates were ultrasonicated in water bath for 30 min, followed by acetone wash(10) then were heated at 650⁰c for 8h in oven (11). 2. carbonpowder preparation:graphite blocks were ground by ball milling and sieved into two groups according to particles size range; 1~50µ micro and 60~125µ macro particles. 3. epd:thermally oxidized cp ti substrate was used for both electrodes. j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 18 single layer micro ha: the distance between the electrodes was10 mm., suspension preparedfroml00g micro ha in 1 liter ethanol (12) andin order to determine the most suitable time and voltage that would give the best ha film 3 voltages were used (30, 40 and 60) v and for each voltages 3 times were used (2, 3 and 5) minutes finally sintering was carried out at 800 c under argon for 2 hours(13). single layer nano ha: the distance between the electrodes was 5 mm., suspension preparedof 0.5g nanoha in 100 ml ethanolin order to determine the most suitable time and voltage that would give the best ha film 3 voltages used (40, 50 and 60), v were used for each voltages 3 times (4, 5 and 6) minutes finally sintering was carried out at 900 c under argon for 2 hours. dual layer nano ha: for the basal layer, the distance between the electrodes was 5mm, suspension was preparedfrom0.5g nanoha in 100 ml ethanol the deposition voltage and time were40v/ 6 minutes finally sintering was carried out at 900 c under argon for 2 hours (1). for the superficial layer,the distance between the electrodes was 5mm., suspension was preparedfrom0.5g nanoha in 100 ml ethanol with 1, 1.5, 2 (14), 10 and 20 wt. percentage micro or macro carbon particlesaccording to the desired pores sizes, the deposition voltage and time were40v/6 minutesfinally sintering was carried out at 700 c under air for 2 hours(15). 4.characterization both tio2 and ha coatings phase analysis was done by x-ray diffractometer (shimadzu, xrd6000, japan), microstructural analysis was done by optical microscope (nikon eclipse me 600l/441002,japan with digital camera type dxm 1200 f) and (vega easy probe scanning electron microscope, spain), thickness measurement was done by microprocess coating thickness gauge (erichsen gmbh & ckg, d-5870 hemer sundwig, w-germany). for tio2 topography analysis scanning probe microscope (angestrom advanced inc., spm-aa3000) was used. shear strength measurements for the ha coatings were done according to astm f1044 –11by using automatic extensometer (instron 1122, england with load cell of 500 n). in vivo 1. implant preparation: eighty screws machined from cp ti grade 2,10mm rod by using lathe machine, then they were thermally oxidized and divided into four groups according to the coatings type; micro ha, nano ha, nano ha with micro pores and nano ha with macro pores coated screws finally the coated screws were sterilized with gamma irradiation dose of 2.5-3.0 mega rad using gamma cells 220 with co60source. 2. implantation and removal torque and histological tests: 16 rabbits were divided into 2 groups for each healing interval (2 and 4 weeks) each one consist of 8 animals, one of them were sacrificed for histological study, while the other 7 were sacrificed for mechanical test by torque removal test. four implants implanted in the tibiae of each rabbit, in the right tibia implant coated with nano ha implanted medially and implant coated with micro, ha implanted laterally in the same tibia, while in the left tibia of the same rabbit implant coated with nano with micro pores, ha implanted medially and implant coated with nano with macro pores implanted laterally in the same left tibia. results phase identification: xrd patterns of unoxidizedcp ti substratesand oxidized substrates were obtained. upon peak matching with the relevant icdd files, before oxidation the peaks corresponded to α–ti and after thermal oxidation of the substrates the peaks corresponded to formation of rutile phase of tio2 as shown in figure 1. xrd pattern of epd deposited and sintered ha coatings on substrates shows there isn’t any unstablephase formed during sintering like ttcp, tcp or calcium oxide,crystallite size in the grains of nano ha coatings was estimated according to sherrer equation (d = b ג / ß cos ), for the single layer of nano ha, the particle size or diameter ranges from 23.1 ~ 138.6 nm and for the dual layer nano ha the particle size or diameter ranges from 20 ~ 198 nm.the results supported the formation of ha coating on oxidized cpti substrate and absence of any other reaction products.no peaks for titania (tio2) are detected in the xrd spectrum, this shows that the sintered hap coating completely cover the entire substrate as shown in figure 2. j bagj bagh college dentistry restorative dentistry unoxidized cp ti grade 2 microstructural optical microscope observations f substrate optical microscope formation of scales after thermal treatment 3.sem showed the formation highly porous su after thermal oxidization, microscope thermally ha coating after sintering the optical microscope observations showed that th uniform coating layer of formed at 40v/2 minutes while for the nano ha coatings nano ha the number of the carbon particles after 1 hour sintering under air proceeded to complete absence after 2 hour h college dentistry restorative dentistry figure 1: unoxidized cp ti grade 2 microstructural analysis: ptical microscope observations f substrates before and after thermal oxidization optical microscope, formation of uniform layer of rainbow colored oxide es after thermal treatment showed the formation highly porous su after thermal oxidization, figure 3: optical figure 4:scanning microscope for the hermally grown tio ha coating after sintering the optical microscope observations showed that th uniform coating layer of formed at 40v/2 minutes while for the nano ha was formed at 40v/6 minutes. while for nano ha with carbon particles the number of the carbon particles after 1 hour sintering under air proceeded to complete absence after 2 hour, as shown in h college dentistry restorative dentistry figure 1:xrd patterns unoxidized cp ti grade 2 substrates. nalysis: ptical microscope observations f before and after thermal oxidization observation showed uniform layer of rainbow colored oxide es after thermal treatment as shown in showed the formation highly porous su after thermal oxidization,figure 4. opticalmicrograph scanning electron the tio2barrier. rown tio2. ha coating after sintering the optical microscope observations showed that th uniform coating layer of the micro ha coatings was formed at 40v/2 minutes while for the nano ha was formed at 40v/6 minutes. while for with carbon particles showed decrease in the number of the carbon particles after 1 hour sintering under air proceeded to complete absence as shown in figure 5. h college dentistry vol. 28 atterns of oxidized ubstrates. ptical microscope observations for cp ti before and after thermal oxidization observation showed that uniform layer of rainbow colored oxide as shown in f showed the formation highly porous su icrograph lectron arrier. view for ha coating after sintering the optical microscope observations showed that the most the micro ha coatings was formed at 40v/2 minutes while for the nano ha was formed at 40v/6 minutes. while for showed decrease in the number of the carbon particles after 1 hour sintering under air proceeded to complete absence 8(1), march 19 xidizedandfigure 2: or cp ti before and after thermal oxidization that the uniform layer of rainbow colored oxide figure showed the formation highly porous surface for ha coating after sintering the optical e most the micro ha coatings was formed at 40v/2 minutes while for the nano ha was formed at 40v/6 minutes. while for showed decrease in the number of the carbon particles after 1 hour sintering under air proceeded to complete absence (a) before s m nano ha, carbon 1% total powder weight nano ha absence of macro pores, the nano ha coatings contained pores up to 1µ only f with 40 voltz and 2 minute electrophoretic deposition, showing the surface m march 2016 figure 2:xrd (a) before s air (c) after sintering in a magnification. hours, at 50&100x figure 5:optical microscopic image for nano ha, carbon 1% total powder weight micro particles c sem for the micro nano ha coating, absence of macro pores, the nano ha coatings contained pores up to 1µ only figure 6: sem for micro ha coat a with 40 voltz and 2 minute electrophoretic deposition, showing the surface m at (100 and 168 xrd patterns (a) before sintering,(b) (c) after sintering in a agnification.for one hour, at 100x for 2 ours, at 50&100xm optical microscopic image for nano ha, carbon 1% total powder weight micro particles c sem for the micro ha coating, f coating,figure 7 after sintering showed the absence of macro pores, the nano ha coatings contained pores up to 1µ only igure 6: sem for micro ha coat a with 40 voltz and 2 minute electrophoretic deposition, showing the surface m at (100 and 168) x sem m the effect of ha. (b) after sintering in (c) after sintering in airat 100x for one hour, at 100x for 2 magnification. optical microscopic image for nano ha, carbon 1% total powder weight micro particles coating. ha coating, f after sintering showed the absence of macro pores, the nano ha coatings contained pores up to 1µ only as shown in igure 6: sem for micro ha coat a with 40 voltz and 2 minute electrophoretic deposition, showing the surface morphology sem magnification. the effect of after sintering in at 100x for one hour, at 100x for 2 agnification. optical microscopic image for nano ha, carbon 1% total powder weight ha coating, figure 6 and after sintering showed the absence of macro pores, the nano ha coatings as shown in figure 8. igure 6: sem for micro ha coat achieved with 40 voltz and 2 minute electrophoretic orphology agnification. of j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 20 figure 7: sem for nano ha coat achieved with 40 voltz and 6 minute electrophoretic deposition after sintering, showing the surface morphology at sem magnification 100 and 500 x. figure 8: sem shows the surface morphology of nano ha after sintering, showing the typical pore size in the nano ha coat, sem magnification 14.76kx. sem for the nano ha with carbon before sintering showed the inclusion of the carbon particles within the nano layer as shown in figure 9, and after sintering showed that for the nano ha coatings with micro and macro carbon particles , the formation of few number of pores corresponded in size of the carbon particle size at 1, 1.5 and 2 % from the total powder weight concentrations, for the nano ha with micro carbon particles the number of pores increased when 10% concentration was used, up to critical level of 20% concentration were large devoid areas of the superficial layer detected as shown in figure 10, while for the nano ha with macro carbon particles when 10% concentration was used, formation of nano ha whiskers were detected, and when 20% concentration was used, pores up to 85µ were detectedfigure 11. figure 9: sem image of the dual nano ha coat with 10% micro carbon, before sintering, shows the sistribution of the sarbon micro particles within nano ha (arrows). (a) (b) figure 10:sem of dual nano ha coat /micro carbon particles with 2 concentrations:(a) 10 % and (b) 20 % from the total powder weight, after sintering at 700ºc for 2hrs in air atmosphere. (a) (b) figure 11:sem of dual nano ha coat/macro carbon particles with 2 concentrations:(a) 10 % from the total powder weight at 25 kx sem magnification, and (b) 20 % from the total powder weight at 500x sem magnification, after sintering at 700ºc for 2hrs in air atmosphere. thickness measurements: formation of 1.6µ thick tio2 detected, while for the micro and nano ha coatings, the thickness increased with increasing both voltage and time, while for the dual nano layer when the voltage and time fixed the thickness was constant (68µ). spm measurementsshowed the formation of oxide with nano topography as shown in figure 12. figure 12: spm shows the tio2 barrier has nano surface roughness. j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 21 shear strength measurements: the highest magnitude for the dual nano ha, followed by single layer nano ha and the least magnitude was for micro ha coatings, as shown in table 1. table 1: values for the mean failure load (newton) with failing stresses or adhesion strength (mpa) for each type of coating type of coat mean failure load /n adhesion strength / mpa micro ha 20 0.4 nano ha 57 1.14 nano ha with micro pore 100 2 nano ha with macro pore 78 1.6 removal torque test: removal torque test revealed that the highest torque mean values were for the screws coated with nano ha at 2 and 4implantationintervals, and statistical analysis done by anova at p=0.05 showed highly significant difference between removaltorque meanvalues for screws coated with four different coatings at eachimplantation intervalsof 2 and 4 weeks, while there was a significant difference only for the dual coat with pores 50 µ between 2 and 4 weeks implantation intervals. histological evaluation: historical evaluation revealed that there was a faster reaction of bone and higher osteoblasts activity towards thermally oxidized cp ti implants coated with nano ha compared to thermally oxidized cp ti implants coated with micro ha at 2 and 4 weeks implantation intervals,as shown in figure 13 and figure 14. early formation of haversian system observed after 2 weeks of implantation at bone implant interface in screws coated with nano ha with macro pores,as shown in figure 15. figure 13: optical microscopesshow newly formed bone trabeculaearound the four different types of ha coatings at 2 weeks implantation intervals. figure 14: optical microscopesshow newly formed bone trabeculaearound the fourdifferent types of ha coatings at 4 weeks implantation intervals. figure 15: optical microscope shows early formation of haversiansystem at bone implant interface in screws coated with nano ha with macro pores after 2 weeks of implantation intervals. j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 22 discussion thermally grown tio2 barrier in the current work, a transition layer of thermally grown titanium oxide is intentionally grown between cpti and epd grown ha coating to prevent ha decomposition as a result of ionic transport from metallic substrate to ha(1).the presence of a tio2 layer also introduces ceramic– ceramic (tio2–ha) interface in place of metal– ceramic (cpti /ha) interface, hence reducing the thermal expansion coefficient mismatch between the coating and substrate (16). the surface morphology of thermally oxidized sample both optical microscopic and sem image clearly reveals the presence of oxide smooth scales throughout the surface without spallation. obviously, the duration of oxidation is considerably high to achieve a good surface coverage with the oxide scale and this agrees with other findings (11). pores are also evident throughout the surface,this microstructural inhomogenities might be generated during the growth of oxide islands and their orientation on the surface, where thermal oxidation would lead to an increase in surface roughness of the oxide film due to the differential oxidation rate of individual grains of the polycrystalline alloy. structural characteristics of untreated and thermally oxidizedsamples the xrd pattern of the untreated cp ti sample is entirely comprised of hexagonal α-phase, while xrd pattern of thermally oxidized sample exhibit the presence of dominant rutile phase peaks, this disagrees with kumar et al (11).weak intensity α-ti peaks are also present and this agrees withkumar et al(11),where α-ti peaks are evident in thermally oxidized cp ti sample having a thin oxide layer and this may be due to that cu–kα radiation could penetrate to a depth of 10~20 μm, much larger than the thickness of the oxide film where the average thickness of the oxide layer is 1.6µ.from the data obtained from the xrd and according to scherer equation, the grain size of tio2 has nano measurements suggesting the presence ofnano surface roughness supported by the measurement provided from the scanning probe microscope, this may be due to the effect of thermal oxidation conditions like temperature and time. oxide film thickness the oxide film average thickness is 1.6µ, measured by microprocess coating thickness gauge, and this disagree withjain et al and kumar et al(10,11),who reported the formation of thicker oxide layer may be due to different thermal oxidation conditions.the surface morphology, oxide grains size and the evolution of surface topography of the oxide film may suggest the mechanism of the growth mode for the oxide barrier which involves the formation of a thin oxide scale followed by its agglomeration and growth, to completely cover the surface, versus oxide film formation mode according to which the nucleation of oxide takes place throughout the surface when it immediately comes in contact with oxygen (11). ha coatings morphology of ha coatings in thepresent study cracks observed across the single layer nano and micro ha which is probably due to thermal expansion mismatch of ha and cp ti substrate. the thermal expansion coefficient of titanium substrate is much lower than that of ha, so large thermal contraction mismatch would arise and tend to induce the formation of cracks when cooled from the elevated temperatures of sintering; besides, a significant firing shrinkage during sintering will lead to the formation of cracks in coatings as well this agrees with wang et al (17). cracks increase in size with increase of the thickness of coating layers, whether the increase of the thickness was due to increase in time or in applied voltage this agrees with the findings of meng et al(13). cracks were clearly seen in the top coating layers in the dual coat approach and it appeared that there is no distinct border between the first and the second coating layers, this agrees with wei et al(1)and may suggest that a strong seamless bonding formed between these two coating layers.the porosity in the single layer micro ha differs from that in nano ha, since porosity is particle size dependent where larger than pores present in micro ha sample compared with nano ha sample, no macro pores are evident, only small pores up to 1μm observed in the coating, this agrees with other findings(2,3). carbon particles with particle size (1~125) µ, was successfully electrophoretically deposited as a composite with nano ha on cp ti substrate, smaller percentages of the carbon particles from the total powder weight didn’t give distinct pores, while increasing the percentage of carbon particles weight from the total powder weight in the deposition process increased the number of the pores in the coatings after sintering this may be due to increased inclusion of carbon particle.the size of the pores in the coatings seems to correspond roughly to the size of the carbon particles used, they are smaller, may be due to thermal contraction after cooling from sintering, except for 20% j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 23 concentration of carbon with particle size (1~50)µ from the total powder weight, carbon particles deposited in large accumulations leaving no clear morphology pores after they had been removed by sintering, only large areas devoid from the second layer. sem image of dual nano ha coat electrophoretically deposited with carbon particles sizes ranges from 60 µ to 125 µ with 10 % concentration from the total powder weight after sintering, it shows the formation of ha nano whiskers; they are rod like particles with high aspect ratio (length to diameter), they possea great influence on osseointegration, and improving mechanical properties, as well as the nano ha whiskers resemble both the size of the nano apatite and the anisotropy in the natural bone(18). ha coatings micro thickness from the results,electrophoretic deposition indicated that the coating thicknessincreases with deposition time under a constant voltage condition and this agreed with the findings ofzhitomirsky(19).alsoepd indicated that the coating thicknessincreases with applied voltage under a constant deposition time, and this agreed with the findings of meng et al(13). although the time and voltage were the same for the first and second layer of the dual coat but the thickness differs between them, where the first layer is thicker, and this may be due to the voltage drop across the first deposited and sintered layer.also the result shows that the carbon particles size didn’t have any effect on the thickness of the dual coat where after sintering the thickness of the both nano ha with micro and macro pores did have same thickness. structural characteristics of ha coatings the xrd patterns for the electrophoretically deposited micro ha coat, nano ha single layer coat and for nano ha dual layer coat showed pure phase of ha after sintering and there is no presence of any decomposition phase, like ttcp, αtcp or cao upon comparison with icdl files, this disagrees withruys et al(16). no decomposed phases are reported may be due to the presence of tio2 barrier that prevent that act as diffusion barrier between the substrate and the coat, as well as for the dual coat might be protected from the metal substrate ion migration and subsequent protection from decomposition, is that the first layer of the coat acts as a diffusion barrier, and application of the first coating layer also created a large diffusion distance to be traversed by the diffusing ions. while the peaks of the micro ha coat after sintering are broad as an index of poor crystallization,the peaks of the nano ha coat both single and dual layers are sharp with low background as an index for high crystallinity and this agrees with wong et al(17). crystallite size in the grains of nano ha coatings after sintering was estimated by using scherrer’s formula, for the single layer nano ha the crystal size or diameter ranges from 23.1 ~ 138.6 nm and for the dual layer nano ha the crystal size or diameter ranges from 20 ~ 198 nm and this agrees with other findings(10,20).the three xrd patterns of micro ha, nano single layer and nano dual layer coatings did not include peaks for the substrate (α-ti), and this may be due to that the sintered hap coating completely cover the entire substrate. this disagrees with wong et aland jain et al(10,20).the three xrd patterns of micro ha, nano single layer and nano dual layer coatings possess high crystallinity as indicated by sharp peaks, this agrees with wong et al(20), also the peaks corresponding to nano ha are much broader than those of micro ha sample which is due to its smaller grain size. shear testing of ha coatings to access the reliability of ha coatings when used in vivo; that is the adhesive strengthor the interfacial shear strengthof the screw coatings upon tightening in the bone during implantation process, the astm f1044 was performed for the micro , nano , nano with micro pores and nano with macro pores ha coatings. in thepresent study, the fracture always happened at the interface of ha coating and ti substrate, for all types of coatings implying that the test was viable and acceptableand this agrees withchen et al(21)and disagrees withwei et al(1). the value of adhesive strength was least for micro ha then nano ha,nano with macro pores and the highest value was for nano ha with micro pores. in general the adhesive strength for the nano was higher than that for the micro ha, this may be due to that the nano particles provide larger interfacial area with the substrate, this agrees with sun et al(22)also the larger pores in micro ha sample compared with nano ha sample,and the larger the pore the more stress concentration and weaker mechanical properties. the larger adhesive strength for the dual layer nano ha as compared with single layer may be due to that when the second coating layer was coated on top of the primary layer, it filled in the cracks in the primary layer, thereby creating coating integrity(1).although they didn’t found correlation between the observed degree of cracking and adhesive strength of nano ha dual coatings.coat integrity may also explains the reason why nano ha j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 24 coat with micro pores has larger adhesive strength than the coat with macro pore. mechanical test in the present study, it has been shown that a difference between different time periods was presentwere the minimum torque value was seen in 2 weeks implantation time while the maximum value was observed in the 4 weeks implantation periods for the four groups.this agreed with the study of johansson and albrektsson(23)thatdemonstrated an increase in the removal torque with time. it has been suggested that this increase depends on an increasing bone-tometal contact with time as a result of a progressive bone formation and remodeling around the implant during healing, whichsubstantially improved the mechanical capacity. a comparison between the different implantation periods in this study shows that after 2 weeks of implantation a higher torque value was needed to remove the screws coated with nanoha, followed by the screws coated with micro ha, then the screws coated with nano ha with macro pores and finally the screws coated with nano ha with micro pores.after 4 weeks of implantation, a higher torque value was needed to remove the screws coated with nano ha, followed by the screws coated with nano ha with macro pores, then the screws coated with nano ha with micro pores and finally the screws coated with micro ha,this may be due to the effect of the surface topography of the ha coat , where removal torque values revealed an increased retention for the chemically modified implants that exhibit specific nano topography, this agrees with meirelles et al(24). in the present study there was a significant difference in torque value between all 4 groups of implant screws coated with nano ,micro , nano with micro pores and nano with macro pores ha,at two periods of healing interval (2 and 4 weeks).regarding the torque values with implantation time, the findings of present study showed that there is significant increase in the torque value after 4 weeks of implantation, only for the screws coated with nano ha with macro pores at p 0.05, this may reflects the importance of the ha coat pores with macro dimension on osteobalsts and osseointegration. histological test the histological analysis of all groups showed a new bone trabeculae formation, with active osteoblats on borders and osteoblast rim activity is also evident, and pre-osteocytes are trapped in the newly formed matrices.the bone trabeculae are thicker at both implantation intervals for the nano ha coated implants when compared to micro ha coated implants, this is due to nanotopography against micro topography which enhance bone formation. this agrees with meirelles et al(24). theimplant coated with nano ha with macro pores in the histological microphotograph showed beginning of haversian system formation at 2 weeks implantation interval this may be due to that macro pores might provide encouraging environment for the progenitor cells to proliferate and differentiate. references 1. wei m, ruys aj, milthorpe bk, sorrell cc, evans jh. electrophoretic deposition of hydroxyapatite coatings on metal substrates: ananoparticulate dual-coating approach. j sol-gel scitechnol 2001; 21:39–48. 2. wei m, ruys aj, milthorpe bk,sorrell cc. precipitation of hydroxyapatite nanoparticles: effects of precipitation method on electrophoretic deposition. j mater sci mater med 2005; 16: 319–324. 3. krause d, thomasm b, leinenbach c, eifler d, minay ej, boccaccini ar. surface and coating technology 2004; 200: 4835-45. 4. d’lima dd, lemperle sm, chen pc, holmes re, colwell jr cw. bone response to implant s 5. surface morphology. j arthroplasty 1998; 13(8):928–34. 6. yuan h, kurashina k, de bruijn jd, li y, de groot k, zhang x. a preliminary study on osteoinduction of two kinds of calcium phosphate ceramics. biomaterials 1999; 20(19):1799–806. 7. kuboki y, takita h, kobayashi d, tsuruga e, inoue m,murata m, et al. bmp-induced osteogenesis on the surface of hydroxyapatite with geometrically fasible and nonfeasible structures: topology of osteogenesis. j biomedmater res 1998; 39(2):190–9. 8. story bj, wagner wr, gaisser dm, cook sd, rustdawicki am. in vivo performance of a modified csti dental implant coating. int j oral maxillofac implants 1998; 13(6):749–57. 9. bae chang-jun,kim hae-won,koh young-hag, kim hyoun-ee. hydroxyapatite (ha) bone scaffolds with controlled macrochannel pores. j mater sci mater med 2006; 17: 517–21. 10. ustundag cb, kaya f,kamitakahara m, kaya c,ioku k. production of tubular porous hydroxyapatite using electrophoretic deposition. j ceram socjpn 2012; 120: 569–73. 11. jain p, mandal t, prakash p, garg a, balanik. electrophoretic deposition of nano crystalline hydroxyapatite on ti6al4v/tio2 substrate. j coat technol res 2013; 10 (2) 263–275. 12. kumar s, narayanan ss, raman gs,seshadri sk. thermal oxidation of cp-ti: evaluation of characteristics and corrosion resistance as a function of treatment time. materials science and engineering c 29 2009; 1942–1949. 13. zhitomirsky i, gal-or. l. electrophoretic deposition of hydroxyapatite. j mater sci mater med 1997; 8: 213219. 14. meng x, kwon ty, kim kh. hydroxyapatite coating byelectrophoretic deposition at dynamic voltage. dental materials j 2008; 27(5): 666-671. j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 25 15. kaya c. electrophoretic deposition of carbon nanotubereinforced hydroxyapatite bioactive layers on ti–6al– 4v alloys for biomedical applications. ceram int 2008; 34: 1843–7. 16. chang-jun b,hae-won k,young-hag k,hyoun-ee k. hydroxyapatite (ha) bone scaffolds with controlled macrochannel pores. j mater sci mater med 2006; 17: 517–21. 17. ruys aj, brandwood a, milthorpe bk, dickson mr, zeigler k.a., and sorrell c.c., sintering effects on the strength hydroxyapatite. j mat sci med 1995; 6: 297. 18. wang z, ni y, huang j. fabrication and characterization of hap /al2o3 composite coating on titanium substrate. j biomed sci and eng 2008; 1:190-194. 19. kumar r., hydroxyapatite-chitosan hybrid nanomaterials 2005, key engineering materials, 284-286, 59. 20. zhitomirsky i. ceramic films using cathodicelectrodeposition. j minerals metals & materials society 2000; 52(1):1-11. 21. wongpk, kwok ct, chengft, manhc.characterization and corrosion behavior of hydroxyapatite coatings on ti6al4v fabricated by electrophoretic deposition. applied surface sci2009; 255:6736–6744. 22. chen f, lam wm, lin cj, qiu gx, wu zh, luk kdk, lu ww.biocompatibility of electrophoretical deposition of nanostructured hydroxyapatite coating on roughen titanium surface: in vitro evaluation using mesenchymal stem cells. j. biomed. mater. res. part b applbiomater 2007; 82: 183–91. 23. sun y, meguid sa, liewand km, ong ls.design and development of new nano-reinforced bonds and interfaces. nsti-nanotech 2004; 3. 24. johansson cb,albrektsson t. integration of screw implants in. the rabbit: a 1-yr follow-up of removal torque of titanium implants.int j oral maxillofac implants 1987; 2:69-75. 25. meirelles l, currie f, jacobsson m, albrektsson t, wennerberg a. the effect of chemical and nanotopographical modifications on the early stages of osseointegration. int j oral maxillofac implants 2008 j; 23(4):641-7. aws.doc j bagh college dentistry vol. 27(2), june 2015 periimplantitis oral and maxillofacial surgery and periodontics 101 periimplantitisa review aws nabeel k, b.d.s. (1) saif seeham saliem, b.d.s., m.sc. (2) abstract this review article concentrates the light about aetiology and treatment of the periimplantitis. (j bagh coll dentistry 2015; 27(2):101-104). introduction the goal of modern dentistry is to restore the patient to normal contour, function, comfort, esthetics, speech, and health, regardless of the atrophy, disease or injury of stomatognathic system. teeth are integral part of the stomatognathic system. the primary function of teeth is to prepare food for swallowing as well as to initiate and facilitate digestion. teeth are also necessary for the articulation of speech and proper looks. implant-based dental rehabilitation techniques has come to offer highly predictable results, hence it has become one more element to be included in the wide range of therapeutic alternatives for totally or partially edentulous patients, albeit some complications have been described in relation with this type of treatment; of these complications, the progressive loss of alveolar bone surrounding the implant is perhaps the most salient. the name periimplant disease refers to the pathological inflammatory changes that take place in the tissue surrounding a loadbearing implant (1) for some authors it is the most common complication in oro-facial implantology (2). two entities are described within the concept of periimplant disease: mucositis: a clinical manifestation characterized by the appearance of inflammatory changes restricted to the periimplant mucosa. if treated properly, it is a reversible process (3). periimplantitis: a clinical manifestation where clinically and radiologically evident loss of the bony support for the implant occurs, together with an inflammatory reaction of the periimplant mucosa (4). (1)high diploma student, department of periodontics, college of dentistry, university of baghdad. (2)assistant professor, department of periodontics, college of dentistry, university of baghdad. etiopathogeny of periimplantitis 1periimplant tissue morphology: healthy periimplant tissue plays an important role as a biological barrier to some of the agents that cause periimplant disease. the epithelium and the interface between the supralveolar connective tissue and the titanium surface of an implant differ from the interface of the dental-gingival unit. like the connective tissue attachment, the epithelium presents a hemidesmosomal attachment to the implant surface; the difference lies in the fact that the epithelial fibers are predominantly longitudinal to the surface of the implant and not perpendicular, as in the case of a natural tooth. in the most coronal region, they are circumferential, in addition to presenting a low degree of vascularization and a higher collagen fiber to fibroblast ratio in comparisonto the tooth (a ratio of 4 in a tooth to 109 in the implant) (5). 2implant structure: the design of the implant is an important factor in the onset and development of periimplantitis. poor alignment of the components that comprise an implant prosthesis system may foster the retention of bacterial plaque, as well as enabling microorganisms to pass inside the transepithelial abutment. 3microbial infection: another cause of periimplantitis, as previously mentioned, is the bacterial colonization of theperiimplant pocket. the association between different microorganisms and destructive periodontal or periimplant disease is governed by the same biological parameters. the microorganisms most commonly related to the failure of an implant are the gram negative anaerobes, like prevotellaintermedia,porphyromonasgingiva lis, actinobacillusactinomycetemcomitans, bacterioidesforsythus, treponemadenticola, prevotellanigrescens, peptostreptococcus micros and fusobacteriumnucleatum (6). 4excessive mechanical stress: another factor that intervenes in periimplantitisaetiopathogeny is excessive j bagh college dentistry vol. 27(2), june 2015 periimplantitis oral and maxillofacial surgery and periodontics 102 mechanical stress. the process begins with the appearance of microfractures of the bone around an osseointegtated implant, as a result of being subjected to axial or lateral stresses that are excessive for its load-bearing capacity. on occasions, these forces cause a prosthetic component (resin, ceramic or the transepithelial abutment screw) or the implant itself to fracture, without any loss of bone height or osseointegration whatsoever. diagnoses, prevalence, and incidence from a clinical standpoint, signs that determine the presence of peri-implant mucositis include bleeding on probing and/or suppuration, which are usually associated with probing depths +4 mm and no evidence of radiographic loss of bone beyond bone remodeling. outcomes from reports (7,8) assessing the prevalence of periimplant diseases revealed that peri-implant mucositis was present in 48% of implants followed from 9 to 14 years affected with this problem. since peri-implant mucositis is reversible with early intervention and removal of etiology, it is quite possible that its prevalence could be under reported. however, when these same parameters are present with any degree of detectable bone loss following the initial bone remodeling after implant placement, a diagnosis of peri-implantitis is made. peri-implantitis can be diagnosed early or once clear clinical evidence has developed. the most common signs and symptoms are: color changes in keratinized gum tissue or in the oral mucosa. bleeding on probing. increased probing depth of periimplant pockets. suppuration. periimplant radiotransparency. progressive loss of bone height around the implant. the absence of bleeding on probing is indicative of good health. probing depth depends on the force applied, so that when equal amounts of force are exerted, the depth reached by the probe is greater in periimplantitis than in the case of a natural tooth. it is recommended the use of probes calibrated to a force of 0.25 n (25 g) to avoid test errors. at any rate, a pocket larger than 5 mm is deemed to have a greater likelihood of being contaminated. on x-ray, the problem can be detected once 30% of the bone mass has been lost; hence this is not an optimal method for early diagnosis of periimplantitis. distinct differences in the incidence and prevalence of peri-implantitis have been reported by a number of authors. most recently, a publication discussed this problem and noted that a literature search of 12 studies in which bleeding on probing and/or purulence were detected with concomitant radiographic bone loss, revealed eight different thresholds of radiographic bone loss used as a disease criteria. this has led to a variation in the reported prevalence of periimplantitis around implants. for example, one study found the prevalence to be 6.61% over a 9 to 14year period (8), another 23% during 10 years of observation (9), and a third reported a prevalence of 36.6% with a mean of 8.4 years of loading (10). the problem with applying differing thresholds for probing depth and radiographic bone loss to define peri-implantitis has been discussed in explaining the variance in reporting the prevalence of peri-implantitis. in one study, the prevalence varied from approximately 11% to 47% of subjects depending on the threshold used (10). although it requires evidence based studies for validation, a peri-implant disease classification has been proposed to aid in explaining disease severity and threshold. risk factors a number of risk factors have been identified that may lead to the establishment and progression of peri-implant mucositis and peri-implantitis (11).the following are some of those factors: 1previous periodontal disease: systematic reviews (12-15) have indicated that although the implant survival rate may not be affected by the periodontal history, peri-implantitis was a more frequent finding in patients with a history of periodontitis. 2poor plaque control/inability to clean: implant prosthesis design can obviate the patient’s ability to mechanically clean the site with brushes, interdental brush, and floss. this can be related to implant positioning and meeting patient expectations for esthetics, phonetics, and function. moreover, prosthesis design can also preclude clinical evaluation with probing and adequate home-care procedures (16). 3residual cement: a growing area of concern has been the incomplete removal of cement left in the subgingival space around dental implants (17). j bagh college dentistry vol. 27(2), june 2015 periimplantitis oral and maxillofacial surgery and periodontics 103 4smoking: four systematic reviews have concluded that there is an increased risk for peri-implantitis in smokers, with odds ratios ranging from 3.6 to 4.6 (12). 5genetic factors: genetic variations have been cited as a risk factor for periimplantitis. however, the association between il-1 gene polymorphism and peri-implantitis remains to be determined since conflicting results exist. 6diabetes: the evidence regarding the association between diabetes and periimplantitis is limited because of the small number of studies. 7occlusal overload: one of the difficulties in conducting clinical studies on this topic rests on the definition of occlusal overload. differences in the magnitude, duration, direction, and frequency of the applied occlusal load and the tolerance threshold of the host are the underlying reasons of the observed conflicting reports. possible mechanisms of why occlusal overload can lead to periimplantitis are conceivable. implants are considered less tolerable to non-axial occlusal load compared to teeth because of a lack of a periodontal ligament. 8potential emerging risk factors: research endeavors continue to explore some additional areas that may impact the development and pathogenesis of peri-implantitis. these include rheumatoid arthritis with concomitant connective tissue disease, increased time of loading, and alcohol consumption. further study will determine the appropriateness of their inclusion. the goals of treatment of periimplantitis 1regeneration of bone structures; complete elimination of inflammatory processes in the peri-implant tissues. 2reduction in the duration of the treatment. 3creation of aseptic conditions around the implant. 4securing the reliability of the implanted artificial supports. the criteria of the treatment • early, the chances of success are best. • supported by procedures designed to lead to the improvement towards healing. • simple removal of local factors is not sufficient. • supported and complemented by surgical and biostimulation procedures. • complex procedures – antibiotics and anti inflammatory drugs. • surgical procedures. • restoration of teeth and arch morphology. • occlusion balancing. • the more diversified the disease, the more it shows an advanced degree in evolution. • designed for each individual, is the main condition of success, to improve the condition, to obtain healing. • treatment of periodontal disease must take into account the general condition of the patient as periodontal treatment can be both local and general. nonsurgical treatment of peri-implantitis amechanical treatments karring et al. compared the results compared the treatment results obtained with the vector® ultrasound system and with carbon fiber curettes (18). after 6 months of follow-up, no significant differences were found between the two techniques, and neither proved sufficient to treat peri-implantitis. these authors evaluated 31 patients, comparing ultrasound (vector® system) and mechanical treatment with curettes. after 6 months, both study groups showed improvement in plaque index and bleeding, though without improvement in terms of pocket depth. there were no significant differences between the groups, and the changes recorded were of no clinical relevance. in relation to bacterial load, there were no differences in the change in bacterial composition in the two groups after treatment. bmechanical treatments associated to antibiotics the recommended antibiotic treatments are amoxicillin, amoxicillin plus clavulanic acid, amoxicillin plus metronidazole, or erythromycin plus tetracycline, with a duration of 7-10 days. the selected articles examined treatment with minocycline microspheres, the use of doxycycline, and the administration of metronidazole. surgical treatment of peri-implantitis aresection techniques resection techniques are used when there are moderate (< 3 mm) horizontal suprabony defects or vestibular dehiscences in a non-aesthetically compromised region. these procedures include ostectomy or osteoplasty, with the raising of an apical repositioning flap and implantoplasty. j bagh college dentistry vol. 27(2), june 2015 periimplantitis oral and maxillofacial surgery and periodontics 104 bregenerative surgery regenerative surgery is used when the implant is decisive for prosthetic preservation, or when aesthetic considerations are involved. regenerative treatment requires prior decontamination of the implant surface. most studies use the concept of guided bone surgery, which includes the placement of a membrane after grafting. many bone substitutes are available, though very few randomized trials have compared them in the context of the treatment of periimplantitis. conclusions most of the factors that lead to implant failure can be controlled by the dentist by means of proper treatment planning prior to implant surgery. the number, diameter and location of the implants depending upon patient bone type and the type of prosthesis to be inserted, are all factors that are clearly within our control. patients undergoing chronic corticoid therapy, poorly controlled diabetics, smokers, those who present active periodontal disease and individuals with serious systemic pathology or predisposing genetic factors should be considered high-risk cases. prognosis of the affected implant will be contingent upon early detection and treatment of mucositis and periimplantitis. references 1mombelli a, lang np. antimicrobial treatment of peri-implant infections. clin oral implants res 1992; 3: 162-8. 2göthberg c, bergendal t, magnusson t. complications after treatment with implant supported fixed prostheses: a retrospective study. int j prosthodont 2003; 16: 201-7. 3jovanovic s. the management of peri-implant breakdown around functioning osseointegrated dental implants, j periodontol 1993; 64:1176-83. 4branemark pi, hansson bo, adell r, breine u, lindstrom j, hallen o, et al. osseointegrated implants in the treatment of edentulous jaw. experience from a 10 years period. scand j plast reconstr surg 1997; 16:1-132. 5berglundh t, lindhe j, ericsson i, marinello cp, liljenberg b, thomson p. the soft tissue barrier at implants and teeth, clin oral impl res 1991; 2: 8190. 6heydenrijk k, meijer hja, van der reijden wa, raghoebar gm, vissink a, stegenga b. microbiota around root-form endosseous implants: a review of the literature, int j oral maxillofac implants 2002, 17: 829-38. 7fransson c, lekholm u, jemt t, berglundh t. prevalence of subjects with progressive bone loss at implants. clin oral implants res 2005; 16: 440-6. 8roos-jansa˚ker am, lindahl c, renvert h, renvert s. nineto fourteen-year follow-up of implant treatment. part ii: presence of peri-implant lesions. j clin periodontol 2006; 33: 290-5. 9marrone a, lasserre j, bercy p, brecx mc. prevalence and risk factors for peri-implant disease in belgian adults. clin oral implants res 2013; 24: 934-40. 10koldsland oc, scheie a, aass am. prevalence of periimplantitis related to severity of the disease with different degrees of bone loss. j periodontol 2010; 81: 231-8. 11rocchietta i, nisand d. a review assessing the quality of reporting of risk factor research in implant dentistry using smoking, diabetes and periodontitis and implant loss as an outcome: critical aspects in design and outcome assessment. j clin periodontol 2012; 39 (suppl. 12):114-21. 12klokkevold pr, han tj. how do smoking, diabetes, and periodontitis affect outcomes of implant treat ment? int j oral maxillofac implants 2007; 22(suppl.): 173-202. 13schou s, holmstrup p, worthington hv, esposito m. outcome of implant therapy in patients with previous tooth loss due to periodontitis. clin oral implants res 2006; 17(suppl. 2):104-23. 14karoussis ik, kotsovilis s, fourmousis i. a comprehensive and critical review of dental implant prognosis in periodontally compromised partially edentulous patients. clin oral implants res 2007; 18: 669-79. 15van der weijden ga, van bemmel km, renvert s. implant therapy in partially edentulous, periodontally compromised patients: a review. j clin periodontol 2005; 32: 506-11. 16serino g, strom c. peri-implantitis in partially edentulous patients: association with inadequate plaque control. clin oral implants res 2009; 20:16974. 17wilson tg jr. the positive relationship between excess cement and peri-implant disease: a prospective clinical endoscopic study. j periodontol 2009; 80:1388-92. 18karring es, stavropoulos a, ellegaard b, karring t. treatment of peri-implantitis by the vector system. clin oral implants res. 2005; 16: 288-93. j bagh college dentistry vol. 26(1), march 2014 dissolution of calcium orthodontics, pedodontics and preventive dentistry 166 dissolution of calcium ion from teeth treated with different concentrations of siwak water extract in comparison with sodium fluoride nibal mohammed hoobi, b.d.s., m.sc. (1) baydaa hussein, b.d.s., m.sc. (2) alhan ahmed qasim, b.d.s., m.sc. (1) manhal abdulrahman, b.d.s., m.sc., ph.d. (3) abstract background: the miswak is a teeth cleaning twig made from a twig of the salvadora persica tree (known as arak in arabic).a traditional alternative to the modern toothbrush, it has a long, well-documented history and is reputed for its medicinal benefits. it also features prominently in islamic hygienical jurisprudence. materials and methods: twenty maxillary first premolars were treated with the selected solutions which included siwak water extract (5%, 10%) and sodium fluoride 0.05% for 2minutes once daily for 20 days interval, deionized water was used as control negative. then the concentration of the dissolved calcium ion in the etching solution of 2n hcl was measured. results: the least amount of the dissolved calcium ion was registered for water siwak extract 10%, then sodium fluoride0.05%followed by water siwak extract5%. a significant difference was found between the two concentrations of siwak water extract, while no significant difference was recorded between the mentioned agents and sodium fluoride. there was highly significant difference between deionized water group and other groups except between water and siwak water extract5% the difference was significant. conclusions: siwak water extract is successful in improving tooth resistance against caries challenge as it mineralize and harden enamel surface. keywords: siwak water extract, calcium dissolution, acid etching. (j bagh coll dentistry 2014; 26(1):166-170). introduction the use of plants as medicines is an ancient and reliable practice (1).tooth brush tree, salvadora persica locally called siwak is a member of salvadoraceae family has been used by many islamic communities as tooth brush and has been scientifically proven to be very useful in the prevention of tooth decay ,even when used without any other tooth cleaning method (2). the wide spread use of siwak among muslims was attributed to the prophet mohammed (peace and blessing of allah be upon him) who recommended its use for tooth cleaning before each of the five daily prayer (3,4). chemical analysis of salvadora persica has demonstrated the presence of sulfur that has a bactericidal effect (5) and vitamin c was found to help in tissue healing and repair (6). silica acts as an abrasive and was found to help in removing stains from tooth surfaces (3,7).the astringent effect of tannins may help to reduce clinically detectable gingivitis. tannins were found to inhibit the action of glucosyltransferase, thereby reducing plaque and gingivitis (8). resins may form a layer on enamel that protects against dental caries. (1) lecturer, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (3)assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. salvadorine, an alkaloid present in s. persica miswak, may exert a bactericidal effect and stimulate the gingiva (6,7). the mildly bitter taste of the essential oils in s. persica miswak stimulates the flow of saliva, which acts as a buffering agent. high concentrations of chloride inhibit the formation of calculus ( 9) and aid in removing stains from tooth surfaces (6).it contains nearly 1.0µglg of total fluoride and found to release significant amount of calcium and phosphorous into water (10). saturation of calcium in saliva due to the use of chewing sticks was found to inhibit demineralization and promote enamel remineralization (8,11) . in 2006, al-obaidy measured the concentration of calcium and phosphorous ions in the crude water siwak extract and found that the concentration of calcium was higher as compared to phosphorous, an interesting result in al-obaidy study was that the water siwak extract at a concentration (5%) was very effective in remineralization of initial carious lesion even better than stannous fluoride (12). studies found that salvadora persica extract is somewhat comparable to other oral disinfectants and antiplaque agents such as triclosan and chlorhexidine gluconate and the use of such extract in tooth paste will protect teeth and gums (13-15).aqueous extract of siwak could be used to reduce the growth of candida albicans (16). the values of these sticks are due to their components and cleaning mechanism. recently http://en.wikipedia.org/wiki/teeth_cleaning_twig http://en.wikipedia.org/wiki/salvadora_persica http://en.wikipedia.org/wiki/arabic_language http://en.wikipedia.org/wiki/toothbrush http://en.wikipedia.org/wiki/islamic_hygienical_jurisprudence http://www.sciencedirect.com.tiger.sempertool.dk/science/article/pii/s1013905212000181#b0255 j bagh college dentistry vol. 26(1), march 2014 dissolution of calcium orthodontics, pedodontics and preventive dentistry 167 these sticks were recommended as an effective tool for oral health by world health organization (who) (17). because siwak contain minerals like calcium that may react with outer enamel surface improving its resistance against acid dissolution therefore, this study was designed to test the ability of water siwak extract to increase the enamel resistance against caries challenge. materials and methods teeth sample consisted of twenty randomly selected human maxillary first premolars extracted from (10-13) year old patients for orthodontic purpose. the extracted teeth were cleaned using conventional hand piece and rubber cup with non-fluoridated pumice and deionized water and stored in 0.1% thymol solution at 4ºc until use, to minimize brittleness of enamel and microbial growth (18) . the siwak water extract was prepared by taking a 250 gm of siwak powder and placed in a beaker to which de-ionized water was added till reach a volume of one liter. the beaker was closed tightly and left to boil at 100oc for 15 minutes, then left to warm, the liquid was then filtered using filter paper (no.1). the filtered water extract was left to dry at 40oc in the incubator for 24 hours, to allow the evaporation of water and to obtain a powder of siwak extract. the powder was collected and kept in tightly closed glass container and kept in refrigerator until use (19).teeth were divided randomly into four equal groups, each group consisted of five teeth and then the teeth were immersed individually for two minutes once daily over twenty days in thirty ml of their assigned test solution which included, siwak water extract (5%, 10%) (12) and sodium fluoride (0.05%) which is the approved concentration of a daily home-used sodium fluoride (20). deionized water group was used as a control negative. after each immersion, the specimens were water washed in deionized water for 5 minutes, then stored in humid condition of deionized water to which 0.1% thymol was added until the next immersion. after the twenty day treatment period, a circular area, 3 mm in diameter were selected on each enamel specimen by applying prepared annular adhesive discs, avoiding macroscopic cracks and hypoplastic areas .the rest of the specimen was covered with a sticky wax, leaving only the circular enamel window exposed for subsequent etching. the windows were etched for ten seconds in separate polyethylene tubes; each containing five ml of 2nhcl .the concentration of dissolved calcium ion was determined by flame atomic absorption spectrophotometer (18). statistical parameters mean and standard deviation were calculated. analysis of variance (anova) and least significant difference (lsd) tests were used to evaluate the significance of difference between different variables. the confidence limit was accepted at 95%. results after acid etching the mean values of the released calcium concentration were illustrated in table(1).the maximum amounts was recorded for deionized water group followed by siwak water extract5% immersed group ,then sodium fluoride treated teeth group, while the least amount of the dissolved calcium was registered for siwak water extract 10% treated group. table (2) showed by anova test the difference in the calcium concentration was statistically highly significant among different groups. in table (3) lsd test was presented to evaluate the difference between each two groups. it showed that there was significant difference between the two concentrations of siwak water extract where as the difference was statistically not significant between the mentioned solutions and sodium fluoride. the difference between water immersed group and the tested solutions was statistically highly significant except between deionized water and siwak water extract solution 5% the difference was significant. discussion siwak has been used by many islamic communities as tooth brush and has been scientifically proven to be very useful in the prevention of tooth decay. the mechanical action of the stick fibers was proved to be effective by many studies (21,22). it was documented that the extracts of these sticks had a drastic antimicrobial effect (7,14,23). many investigators found that siwak contains efficient chemical substances as alkaloids, fluoride, calcium, phosphorous, etc, these agents may have antibacterial action in addition it may chemically react with the outer enamel surface (24,25). in this experiment a water extract of siwak (salvadora persica) was chosen to investigate its ability to decrease the loss of calcium ions from enamel of teeth which immersed in 2n hcl (increase enamel hardness) in comparison to sodium fluoride and deionized water. sodium fluoride was used as a control positive because of its well documented ability to increase the enamel resistance to acid dissolution that protect tooth against dental caries (26,27), while de-ionized water was used as a control negative. siwak sticks were j bagh college dentistry vol. 26(1), march 2014 dissolution of calcium orthodontics, pedodontics and preventive dentistry 168 powdered and water extract was prepared according to al-jeboory technique (19). many types of siwak extract are present beside water siwak extract, as ethanol and chloroform and ethanol siwak extracts, but the aqueous one was selected due to the uniform solvent of the used agents. it was shown by previous iraqi study that water siwak extract can be easily prepared and effective even more than other types of extracts (14). calcium is one of the enamel major elements that comprise about 33.6%-39.4% of hydroxyapatite crystal (28,29),therefore it was chosen to test its dissolution upon exposure to acid attack. after treatment of the enamel samples with water siwak extract (5%, 10%) and sodium fluoride 0.05%, an acid etching revealed that the released calcium ion concentration was higher for deionized water than the selected solutions and the difference was statistically highly significant except between water and siwak water extract 5% the difference was statistically significant .this may be an indication of incorporation of ions that decrease porosity, and increase enamel microhardness against demineralizing action of acid. when sodium fluoride solution is applied on the tooth surface as topical agent, it reacts with the enamel to form calcium fluoride or fluoridated hydroxyapatite crystal and these will increase the concentration of fluoride on enamel surface which in turn makes the tooth surface more resistance to acid attack (29). concerning siwak water extract, its mineralizing ability may be related to its content of calcium and phosphorus ions which are the major components of hydroxyapatite crystal, in addition to other anticariogenic ions like fluoride (30). it was proposed that these ions incorporated in the outer enamel surface harden it and explain this difference in the concentration of dissolved calcium between siwak water extract and deionized water.this combination of cariostatic ions in siwak could also explain the higher amount of released calcium from teeth treated with sodium fluoride compared with those treated with siwak water extract 10% and the difference was not significant. the concentration of the dissolved calcium ions from the acid-etched teeth immersed with 10% siwak water extract was less compared with that after treatment in 5% of the extract and the difference was significant. an increase in the concentration of siwak water extract result in an increase in the concentrations of calcium, phosphorus and fluoride, the increase in calcium and phosphorus in the extract led to an increase in ca/p ratio thus increase the resistance of enamel to acid dissolution and increase in concentration of fluoride in enamel surface made the tooth surface harder (12,31) . it is not well understood what was the type of reaction took place with enamel surface, which finally decrease the concentration of the dissolved calcium ion, it may be attributed to its content of calcium and phosphorous. both ions are the major components of apatite crystals. other studies reported a presence of a small amount of fluoride. presence of calcium, phosphorous and fluoride ions in siwak extract make the assumption of production of calcium fluoride, in addition to fluoroapatite crystals and fluorohydroxyapatite crystals, all these may increase the mineralization of porous enamel, thus decreasing calcium release from enamel surface. an interesting result recorded in this study was the lowest concentration of calcium ions released from enamel surface was for 10% water siwak extract compared to its 5% concentration. as the concentration of calcium ions from enamel surface was measured, water siwak extract at 10% was found to produce minimum demineralization as the lowest calcium concentration was recorded for it. sodium fluoride came the next then 5% water siwak extract and finally de-ionized water. one can reveal from above results that water siwak extract at a concentration 10% was very effective in increasing the resistance of enamel to demineralization even better than sodium fluoride. these results need to be confirmed by further studies involving in vivo, before the recommendations of using water siwak extract in dental practice as an active way for prevention of dental caries. references 1. arshad m, rao a. medicinal plants of cholistan desert. in anwar r, haq n, masood s. medicinal plants of pakistan, 2001.p.1. 2. salehi p, momeni danaie sh. comparison of antibacterial effects of persica mouth wash with chlorhexidine on streptococcus mutans in orthodontic patients. daru 2006; 14: 178-82. 3. khoory t. the use of chewing sticks in preventive oral hygiene. clin prev dent 1983; 5(4): 11-4. 4. gazi mi, lambourne a, cyagla ah. the antiplaque effect of toothpaste containing savadora persica compared with chlorhexidine gluconate. clin prev dent 1987; 9(6): 3-8. 5. grant j. miswak toothbrushes that grow on trees todays. fda 1990; 2: 60. 6. al-sadhan r, almas k. miswak chewing sticks, a cultural and scientific heritage. saudi dent j 1999; 11(2): 80-7. 7. al-lafi t, ababneh h. the effect of extract of miswak used in jordan and the middle east on oral bacteria. int dent j 1995; 45(3): 218-22. 8. gazi mi, davies tj, al-bagieh n, cox sw. the immediate and medium term effect of meswak on the j bagh college dentistry vol. 26(1), march 2014 dissolution of calcium orthodontics, pedodontics and preventive dentistry 169 composition of mixed saliva. j clin periodontal 1992; 19: 113-7. 9. akhtar ms, ajmal m. significance of chewing sticks (miswak) in oral hygiene from a pharmacological view point. j pak med assoc 1981; 31(4): 89 – 95. 10. halawany h. areview on miswak (salvadora persica) and its effects on various aspects of oral health. saudi dent j 2012; 24(2): 63-69. 11. amin tt, al-abad bm. oral hygiene practices, dental knowledge, dietary habits and their relation to caries among male primary school children in al hassa, saudi arabia. int j dent hyg 2008; 6: 361–70. 12. al-obaidy n. effect of siwak extract on the microhardness and microscopic features of initial caries like lesion of permanent teeth compared to fluoridated agents. a master thesis, college of dentistry, university of baghdad, 2006. 13. ezmirly st, cheng jc,wilson sr. saudi arabian medicinal plants salvadora persica. chemistry and industry 2001; 21: 191-2. 14. al-nidawi a. effect of siwak extracts on mutans streptococci in comparison to selected antimicrobial agents. a master thesis, preventive dentistry, university of baghdad, 2004. 15. wolinsky le, sote eo. isolation of natural plant inhibiting substances from nigerian chewing sticks. caries res 1984;18(3):216-25. 16. edi ma, selim ha. retrospective study on the relationship between miswak chewing stick and periodontal health. egyptian dent j 1994; 40: 589-92. 17. ardakani f. efficacy of miswak (salvadora persica) in preventing dental caries. j health 2010; 2(5): 499-503. 18. barbakow f, sener b, snr lab tech, lutz f. dissolution of phosphorus from human enamel pretreated in vitro using snf2 stabilized with amine fluoride 297. clin prev dent 1987; 9(5): 3-6. 19. al-jeboory a. ethnopharmacology. baghdad: alhauria house press; 1994. 20. featherstone jd. prevention and reversal of dental caries role of low level fluoride. community dental epidimiol 1999; 2: 31-40. 21. gazi m, saini t, ashri n, lambourne a. meswak chewing stick versus conventional tooth brush as an oral hygiene aid. clin prev dent 1990; 12(4): 19 – 23. 22. el-samarrai s, al-deen l, al-azawi l. comparative effects of siwak and tooth brush on plaque index and gingival index among groups of dental students. iraq dent j 1997; 19: 169 – 81. 23. almas k. the antimicrobial effects of extract of azadirachta indica (neem) and salvadora persica (arak) chewing sticks. indian j dent res 1999; 10(1): 23–6. 24. darout ia, christy aa, skaug n, egeberg pk. identification and quantification of some potentially antimicrobial anionic components in miswak extract. indian j pharmacol 2000; 32: 11-4. 25. alali f, al-lafi t. gc – ms analysis and bioactivity testing of the volatile oil from the leaves of the toothbrush tree salvadora persica l. nat prod res 2003;17(3): 189-94. 26. al-anni m. effect of selected metal salts on the microhardness and microscopic feature of initial carious lesion of permanent teeth. a master thesis, preventive dentistry, university of baghdad, 2005. 27. shaker n. effect of water extract of cinnamon on the microhardness and microscopic feature of initial caries –like lesion of permanent teeth compared to fluoridated agent. a master thesis, college of dentistry, university of baghdad 2008. 28. thylstrap a, fejerskov o. textbook of cariology. 1st ed. copenhagen: munksgaard; 1986. p.189. 29. peter s. essentials of preventive and community dentistry. 2nd ed. darya ganj. new delhi: arya publishing house; 2004. 30. hattab fn. meswak, the natural tooth brush. j clin dent 1997; 8: 125-9. 31. stooky gk. critical evaluation of the composition and use of topical fluorides. j dent res 1990; 69: 805-12. table 1: concentration of calcium ion (mean and standard deviation) dissolved in 2 n hcl from enamel treated with selected agents table 2: anova test among different solutions sum of squares df mean square f-value p-value. between groups 16.88 3 5.62 7.64 .002** within groups 11.77 16 .73 total 28.65 19 ** highly significant agent no. mean (mmol/ l) ±sd siwak5% 5 2.92 1.182 siwak10% 5 1.80 0.132 naf0.05% 5 2.05 0.732 deionized water 5 4.15 0.99 j bagh college dentistry vol. 26(1), march 2014 dissolution of calcium orthodontics, pedodontics and preventive dentistry 170 table 3: least significant difference (lsd) between each two agents agent(1) agent (2) mean difference sig. siwak 5% siwak10% 1.11 .056* naf0.05% 0.81 n.s. deionized water 1.2 3 .038* siwak10% siwak5% 1.11 .056* naf0.05% 0.24 n.s. deionized water 2.3 4 .001** naf 0.05% siwak5% 0 .87 n.s. siwak10% 0.24 n.s. deionized water 2.1 0 .001** deionized water siwak5% 1.23 .038* siwak10% 2.34 .001** naf0.05% 2.1 0 .001** *. significant ** highly significant j bagh college dentistry vol. 31(4), december 2019 evaluation of 71 evaluation of effect of local exogenous application of myrrh oil on healing of wound incisions of facial skin (histochemical, histological and histomorphometrical study in rabbits) nawar bahjet kamil, b.d.s , m.sc. (1) nada m. h. al-ghaban, b.d.s, m.sc., ph.d. (1) abstract aim of the study: is to evaluate the effect of myrrh oil local application on the healing process of skin wounds histologically , histomorphometrically and , histochemically. materials and methods:twenty male white new zealand rabbits were used in this study. an incisional wounds with full thickness depth and of 2 cm length were done on both sides of the cheek skin of each rabbit. the left sided incisions (the control group) were irrigated with distilled water (10µl). the right sided incisions (the experimental groups) were treated with myrrh oil (10µl). each group was subdivided into 4 subgroups according to the healing interval into 1,3,7 and 14 days(5 rabbits for each group). results: histological findings of our current study showed a highly significant difference between the experimental and the control groups in count of the inflammatory cells which showed that mean values increased with time for the control and the experimental groups. the histomorphometrical findings had shown that the thickness of the epithelium was nearly completed at about 7 days for the experimental groups and at about 14 days for the control. the blood vessels count was recorded to have a highly significant difference between the groups at days 1 and 3 only. the histochemical findings had shown that the collagen fibers remodeling had recorded a highly significant difference between the control and the experimental groups at days 7 and 14. conclusion: the current study had revealed that myrrh oil accelerates wounds healing in rabbits. key word:wound healing , myrrh oil, masson’s trichrome staining. (received: 25/11/2018; accepted: 3/1/2019) introduction: the skin can be defined as an interface or a barrier between the body and the external environment (1). a wound can be described as a loss of the function and integrity of the body tissues. the injury can be usually caused by an external force (traumatic/accidental or surgical) and it can involve any type of organs or tissues (2). the process of wound healing, which is considered a normal biological process of the body, can be achieved by four highly programmed, strict and precise phases. these phases include: "hemostasis, inflammation, proliferation, and remodeling". for a successful healing of any wound, the four phases must occur in the proper sequences and accepted time limit (3). myrrh oil is described as a hardened sap that oozes from the commiphora molmol stem (family burseracea) tree. it is collected from the natural cracks or it can be from cuts made by human in the trees bark (4). myrrh had been used frequently in the recorded history and it had been concidered to be a fragrance and also a medical agent by "the ancient chines and by the old egyptians" (5). "caryophyllene c15h24" which is present in myrrh oil also has an anti inflammatory, antibacterial and anti tumor action (6). 1. department of oral diagnosis, college of dentistry, university of baghdad. marerials and methods twenty new zealand male rabbits, of (1.5– 2 kg) body weight and (4-7) months of age were used in this study. all of the rabbits were housed with controlled ventilation conditions and temperature and were given a standard diet (barseem and pellet) with an easy accessed tap water. the animals were kept in a standard separated cages for 2 weeks in the same suitable environment before the surgical procedure. all of the animals underwent examination by "veterinarian staff in the animal house of biotechnical research center at alnahrain unniversity" for the evaluation of their general condition and health in order to exclude any unhealthy animals. the animals then were fasted about 6-8 hours before the operation. all of the experimental procedures were done in accordance with "the animal experimentation ethical principles" (7). a full skin thickness surgical incisional wounds and 2 cm length were done on both sides of the cheek skin for each rabbit (11). the animals then were randomly divided in accordance to the healing intervals into 4 groups (1,3,7,14) (5 rabbits in each group) and each group was subdivided in to: 1control group: the left sided incisions were irrigated with distilled water. 2experimental group: the right sided incisions j bagh college dentistry vol. 31(4), december 2019 evaluation of 72 were treated with 10µl of a myrrh oil. all of the specimens were taken and prepared for the histological (h&e stain) and the histochemical examination with masson's trichrome stain for collagen fibers density assessment. assessment of wound healing parameters clinical assessment wound contraction: at 3,7 and 14 days period interval the wounds were measured by ruler (8,9). 2 histological analysis 1. inflammatory cells analysis : with power x40 lens, we counted the inflammatory cells number in five fields and then recorded the mean number of cells (10). 2. epithelial thickness assessment: with power x40 lens, the measurement of the epithelial thickness was performed by measuring the distance from the outermost layer of the epidermal keratin to the inner most basal layer of it at the edges of the wound as a mean of two readings with the help of image j computer software (11). 3. blood vessels analysis: blood vessels analysis was done using the image j software. using light microscope, power x40 lens (12). 4. collagen fiber density analysis: the slides were stained with masson’s trichrome stain and were examined under the light microscope, power x40, at 3,7 and 14 days period intervals with the help of image j software (13). results wound contraction estimation: table (1) is showing that with time there is a decrease in the recorded mean values, and that there is a high significant difference between the control and the experimental groups in all healing periods. inflammatory cell parameter the results showed as in table (2) that the highest mean values were recorded for the experimental groups at day 3 and the lowest mean value was at 14 days. the epithelial thickness parameter: results had revealed as shown in table (3) that the epithelial thickness highest mean value for the control and the experimental groups was recorded at day 14 and that the lowest mean value for both both groups wasrecorded at day 1, also it showed a highly significant differences between the control and the experimental groups at all healing period intervals (p<0.01). table 1: descriptive statistics of wound contraction at different healing period table 2: descriptive statistics of inflammatory cells account in each period interval time/day control mean±sd myrrh mean±sd pvalue lsd 1 days 0.95 1.9 0.000** -4.8 3days 3.81 7.94 0.000** -20.5 7days 17.69 32.41 0.000** -6.82 14days 42.11 63.22 0.000** 18.84 blood vessels account: as shown in table(4), the study revealed that the blood vessels count highest mean value that was recorded for the experimental groups was at day 3, and for the control groups was at day 7. while the control and experimental groups lowest mean time/da y control mean±s d myrr h mean ±sd p value ls d 3 days 1.86 1.56 0.000* * 0.3 0 7 days 1.50 1.18 0.000* * 0.3 2 14 days 0.80 0.09 0.000* * 0.7 1 j bagh college dentistry vol. 31(4), december 2019 evaluation of 73 values were recorded at day 1 and there was no significant difference at 7 and 14 days. collagen fiber density: the study results revealed that the recorded highest mean values for the control and the experimental groups were at 14 days and the lowest mean values were recorded at day 3 as shown in table 5. histological finding (h&e and masson’s trichrome chemical stain) • one day duration: (control group ) fig. (1) fig. 1: view of control group at day 1showed inflammatory cells infiltration and scab,h&e,x40. one day duration :experimental group (m) fig. (2) table 3: descriptive statistics of epithelial thickness (µm) in each period interval table 4: descriptive statistics of blood vessels account in each period interval table (5) descriptive statistics of the collagen fiber density (%) in each period interval time/day control mean±sd myrrh mean±sd p value lsd 1 day 0.80 2.40 0.003** -1.40 3 days 3.60 7.40 0.000** -4.60 7 days 7.80 5.80 0.09 1.00 14 days 6.40 5.90 0.52 0.40 time/day control mean±sd myrrh mean±sd p value lsd 3days 18.83 41.43 0.000** -22.6 7days 24.19 54.72 0.000** -29.4 14days 44.11 68.67 0.000** 23.5 time/day control mean±sd myrrh mean±sd p value lsd 1 day 11.80 31.40 0.000** -19.6 3 days 17.60 27.00 0.000** -9.4 7 days 26.40 15.20 0.000** 9.2 14 days 22.80 10.60 0.000** 12.2 j bagh college dentistry vol. 31(4), december 2019 evaluation of 74 a b figure 2: view of myrrh oil group at day 1showed a: epithelial cutting edge and migration of basal cell , h&e,x40.b: showed infiltration of inflammatory cells in dermis as black points,h&e,x40. three days duration(control group) fig. (3). a b figure 3: view of control group at day 3 showed showed a: epithelial proliferation, h&e, x40 b: fine collgen fiber and granulation tissue mtx10. three days duration experimental group(m) fig. 4. a b figure 4: view of myrrh oil at day 3 showed ,a: scab, new epithelium , inflitrationof inflammatory cells and hair follicle, h&e,x10.b: new fine collagen fiber, mt,x40. seven days duration(control group) fig. 5. j bagh college dentistry vol. 31(4), december 2019 evaluation of 75 a b figure 5: view of control group at day 7 showed, new epithelium formation, and scab, h&e,x10..b: g: granulation tissue, blue area: coarse of collagen fibers, mt, x40. seven days duration (experimental group): fig. 6 a b figure 6: view of myrrh oil group at day 7 showed, a: keratin , new epithelium, h&e,x10.b: blood vessels, col: coarse of collagen fibers, g: granulation tissue, mt, x40. fourteen days duration: control group: fig. 7 a b figure 7: view of control group at day 14 showed, a: keratin layer, epidermis, granulation tissue, h&e,x10. b: granulation tissue and blue area: remodeling of collagen fiber. mt,x40. fourteen days duration (experimental group):fig. 8 j bagh college dentistry vol. 31(4), december 2019 evaluation of 76 a b figure 8: view of myrrh oil group at day 14 showed, a: keratin layer, hf, complete formation of epithelium, h&e, x10.b: large area occupied by remodeling collagen fiber (col) and invaded by blood vessel, mt, x10. discussion nowadays, medicinal herbals are considered to be one of the branches of the complementary and alternative medicine. herbals use for caring of wounds and injuries had been known since the ancient civilizations (14,15). our present study had shown that wounds contraction was accelerated in the experimental groups as compared to the control groups. this acceleration in the wounds contraction can be explained be due to the increased proliferation and progression of the epidermal cells in the experimental groups and because of the anti inflammatory effect of this oil (16). histological and histomorphometrical evaluation: in our study the experimental groups had displayed variable degrees of the inflammatory reaction especially in the first 24 hours, in contrast to the control groups which had displayed a more prolonged and sever inflammatory reaction extending up to the 7th day attributed to the bacterial colonization and the lack of the immunomodulation and the antiinflammatory activities. this agrees with (almobeeriek,2011)(17) the intensity of the inflammatory cells in the wounds areas was found to be predominant and the density of the inflammatory reactions was more sever in experimental groups as compared to the control groups in the 1st and 3rd day, while in the 7th and 14th days the inflammatory cells had become mild because of the established and completed inflammatory stage and the start of the remolding stage in the experimental groups, while they recorded a high mean value in the control groups at day seven and a decrease in day fourteen. this may be because of the anti bacterial effects of the myrrh oil (18,19) and this had led to the promotion and the acceleration of the healing processes. neovascularization is another very important event that should take place in the 2nd stage of the wound healing (20). in our study, in the 1st day, the neovascularization in the control groups was found to be little or nearly absent, while in the experimental group, it was present but to a very little extent, high significant differences was recorded between the control groups and the experimental groups in day 1 and 3 but there was a none significant difference in the days 7 and 14. the early neovascularization in the experimental groups had led to promote the healing process because new vessels usually supplies oxygen and the required nutrients and remove the waste products (21). the present study had shown that the reepithelialization had occurred faster in the experimental groups and it recorded a high significant difference as compared to the control groups because of the increased proliferation and the progression of the epidermal cells with an increment in the amount of the neovascularization, the fibroblast cells and the collagen fiber of the dermal layer in the experimental groups and this agrees with (almobeeriek,2011)(17), the remodeling phase had started earlier in the experimental groups than in the control groups and this agrees with a previous study (al-mobeeriek,2011)(17). "masson’s trichrome stain" was used in this study for assessment of the density of the collagen fiber, this agrees with previous study (suvik, and effendy, 2012)(13)the experimental groups had been found to have a higher collagen density than the control groups at day 3,7 and 14 and this agrees with a previous study (enoch and leaper, 2007;reinke and sorg, 2012)(22,23) j bagh college dentistry vol. 31(4), december 2019 evaluation of 77 conclusion myrrh oil has the ability to accelerate healing of the wounds because of the faster wounds contraction, early neovascularization, reepithelization and a higher collagen density than the control groups. myrrh oil groups had shown an anti-inflammatory effects which is identified by a decrease in the count of the inflammatory cells with time. references 1. 1.hongbo ,z. and maibach, hi. 2004. dermatotoxicology. crc press lcc, usa, 6: 938-955. 2. rose, l.and hamm,dpt.2015.text and atlasof wound diagnosis and treatmeant,new york mcgrow hill,chapter (1):1-39. 3. thiruvoth ,fm., mohapatra, dp., kumar, d., chittoria ,s r k., nandhagopal, v.2015. current concepts in the physiology of adult wound healing.plastic and esthetic research. indea, 2:2506. 4. marshall,s. 2004. myrrh: magi, medicine and mortality. the pharmaceutical j. 273: 919-921. 5. etman, m., amin, m., nada, ah., shams-eldin ,m. and salama, o .2011. emulsions and rectal formulations containing myrrh essential oil for better patient compliance. drug discov ther, 5, 150 156. 6. suad, a. gadir , ibtisam, m.and ahmed, j. 2014. chem. pharm. res., 6(7):151-156. 7. rollin, a. and bernard,e.2006.the regulation of animal research and the emergence of animal ethics :a conceptual history. theoretical medicine and bioethics,27(4):285-304. 8. al-kadhimi,b.,j. 2014. effect of topical application of estrogen hormone on wounds healing in ovariectomized rabbits, university of baghdad,m.sc.thesis. 9. kumar, a.chomwal, r., kumar, p. and sawal, r. 2009. anti inflammatory and wound healing activity of curcuma aromatic salisb extract and its formation. journal of chemical and pharceutical research, 1(1):304-310. 10. accorinate, m., holland, r., reise, a., bortuluzzi, m. and murate, s.2008. union of mineral trioxide cement as pulp capping agent in teeth ,journal of endo,34:1-6. 11. gal,p.,vidinsky,b. and toporcer,t. 2006. histological assessment of the effect of laser irradiation on skin wound healing in rats.photomed. las. surg.,24(4):408-488. 12. wosgrau, acc., jeremias, tds., leonardi ,df.,pereima, mj di., giunta, g.and trentin, ag .2015.comparative experimental study of wound healingin mice: pelnac versus integra. plose one journal.pone ,10(3). 13. suvik, a. and effendy a.w.m. 2012. the use of modified masson’s trichrome staining in collagen evaluation wound healing study. malaysian journal of veterinary research 3 (1): 39-47. 14. hajiaghaalipour,f.,kanthimathi,ms.,abdulla,ma. and junedah sanusi, j.2013.the effect of camellia sinesis on wound healing potential in an animal model .evidencebased complementary and alternative medicine research article,2:1-7. 15. nezhad, hr., sahhri, nm. and rakhshandeh. 2013.the importance of tomeric extract on wound repaire in rate. animals of biological research,4(12):123-128. 16. shalaby ,m a. and hammouda ,a a-e. 2014. analgesic, anti-inflammatory and antihyperlipidemic activities of commiphora molmol extract (myrrh).j intercult ethnopharmacol , 3(2): 56–62. 17. al-mobeeriek,a.2011.effect of myrrh on intra oral mucosal wounds compared with tetracycline and chlorhexidine based mouth washes. clinical, cosmetic and investigational dentistry,3:53-58. 18. almekhlafi,s., anes, a. m., thabit, ameen, m. i., alwossabi, awadth,n. abdulbaqi, a. m. and zaid algaadari,z.2014. antimicrobial activity of yemeni myrrh mouthwash. journal of chemical and pharmaceutical research, 6(5):1006-1013. 19. elsarag, smm. 2008. the activity of commphora myrrh against microorganism recoverd rfom wounds.msc thesis, sudan university of science and technology. 20. gurtner, gc. werner, s. barrandon, y. longaker, mt. wound repair and regeneration. nature. 2008; 453 (7193):314–21. 21. shaykhiev, r., beisswenger, c.and kandler ,k. 2005. human endogenous antibiotic ll-37 stimulates airway epithelial cell proliferation and wound closure. am j physiol lung cell mol physiol. 289(5):l842–848. 22. enoch, s. and leaper, d.j. 2007. basic science of wound healing. surgery; 26(2):31-37. 23. reinke ,jm. and sorg, h. 2012. wound repair and regeneration. eur surg res., 49: 35-43. الخالصة فقدان الوظيفة الحيوية وسالمة النسيج او العضو يحدث بسبب تداخل جراحي او حادث. التئام الجروح يعتبر عملية بيولوجية طبيعية خلفية الموضوع: الجروح هي التكاثر واعادة البناء. ‘االلتهاب ‘ في جسم االنسان ويتحقق من خالل اربع مراحل مبرمجة بدقة عالية وهي : وقف النزف وقد اثبت نبات المرة خصائصه كمضاد لاللتهابات ومعقم للجروح والخدوش ومحفز اللتئام ‘د من فروع الطب بأشكال مختلفة طب االعشاب يمكن ان يعَرف كواح . الجروح وعالج االلتهابات .كنسيج كيميائي وتحليل شكلي نسيجي ‘اهداف الدراسة :تقييم تأثير االستخدام الموضعي لزيت المرة نسيجيا مجموعة ,ام اربعين ارنبا نيوزلنديا في هذه الدراسة وتم عمل جرح كامل السمك وبطول سنتمترين على جانبي جلد الخد االيمن وااليسر المواد والطرائق: تم استخد مجموعة زيت المرة )وتشمل عشرون جرح وتم معالجتهم بعشرة ماكروميتر من زيت ،التحكم )وتشمل عشرون جرح في الجهة اليمنى تم غسلهم بالماء المقطر( يوم( 1,3,7,14المرة( ثم قسمت الى اربع مجاميع حسب فترة الشفاء ) سمك الطبقة الطالئية وعدد االوعية الدموية، ايضا تم تحضير ، كل العينات تم تحضيرها نسيجيا باستخدام صبغة الهيماتوكسلين واإليوزين وتم تقييم الخاليا االلتهابية تراي كروم وتم فحص االلياف الكوالجينية. العينات باستخدام الصبغة الكيميائية ماسون القدرة على تسريع التئام الجرح حيث ان جميع مجاميع التجربة كانت لها اقل معدل قيمة في اليوم هالنتائج: النتائج النسيجية للدراسة الحالية اوضحت بان زيت المرة ل بالمقارنة مع مجموعة التحكم. 14 اصية المضادة لاللتهابات حيث لوحظ ان عدد الخاليا االلتهابية قد تناقصت مع مرور الوقت. كما اثبتت ان زيت المرة لهما الخ https://www.ncbi.nlm.nih.gov/pubmed/?term=shalaby%20ma%5bauthor%5d&cauthor=true&cauthor_uid=26401348 https://www.ncbi.nlm.nih.gov/pubmed/?term=hammouda%20aa%5bauthor%5d&cauthor=true&cauthor_uid=26401348 https://www.ncbi.nlm.nih.gov/pmc/articles/pmc4576796/ j bagh college dentistry vol. 31(4), december 2019 evaluation of 78 ك الخاليا الطالئية في دراسة النسيج الشكلي اوضحت ان سمك الخاليا الطالئية في مجموعة التجربة تقريبا اكتمل في اليوم السابع بينما مجموعة التحكم اكتمل سم . 14اليوم االوعية الدموية كان اسرع في مجاميع التجربة بالمقارنة مع مجموعة التحكم. تكوين (، وكان اكثر كثافة 3،7،14دراسة النسيج الكيميائي اوضحت ان االلياف الكوالجينية سجلت اختالف عالي ومهم بين مجموعة التحكم ومجموعة التجربة في االيام ) في مجاميع التجربة. ban f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of microvessels oral diagnosis 43 assessment of microvessels density and inflammatory status in oral lichen planus ban f. aldrobie, b.d.s. m.sc., ph.d. (1) abstract background: oral lichen planus (olp) is a chronic inflammatory disease with an autoimmune inflammatory pathogenesis. the purpose of this study was to evaluate the role of angiogenesis in the pathogenesis of olp, using cd34 stain to highlight the blood vessels for measuring the microvessel density (mvd) as well as to evaluate the relation of this marker with the degree of inflammation materials and methods: immunohistochemical (ihc) staining technique was used to evaluate angiogenesis using cd34 in 46 paraffin blocks 10 of them obtained from normal mucosa and 36 from cases diagnosed as lichen planus , 20 of them diagnosed as reticular type while 16 as erosive type. severity of inflammation was divided into mild, moderate and severe according to the number of mononuclear cell infiltrate. results: the mean mvd as determined by the mean number of cd34 positive vessels in hot areas for olp group was higher 39.2 (31.9 for reticular group & 48.375 for erosive group), whereas the mean mvd for control group 19.5 so that there was statistically significant difference between olp group and the control group (p value<0.001). regarding the severity of inflammation mean mvd was significantly increased as the degree of inflammation increased ( p value<0.001). conclusion: angiogenesis may be an integral component associated with the development of the olp key words: oral lichen planus, angiogenesis, cd34, microvesels density. (j bagh coll dentistry 2013; 25(special issue 1):43-47). introduction oral lichen planus (olp) is a chronic inflammatory disease with unknown etiology appears in different clinical forms and neville et al. recognized essentially two types, the reticular and the erosive (1) .olp affects approximately 2% of the population (2,3). the reticular lesions appear as a network of connecting and overlapping lines, papules or plaques. the erosive and ulcerative forms are more destructive forms and cause enormous oral discomfort (4), while reticular forms are associated with fewer symptoms and therefore might reflect an intermediate phase (5). lp most commonly affects middle-aged people, although childhood-onset lp has also been well described. women are affected as frequently as men.olp is a self-limited condition that, according to one epidemiologic study, may resolve after 1 month to 7 years.(6) a range of topical and systemic medications have been shown to improve the symptoms associated with lp and to hasten the resolution of lp (7). the pathogenesis of olp is not entirely understood. in general, activated t lymphocytes are recruited to the dermal–epidermal junction and induce apoptosis in basal keratinocytes. both cd4+ and cd8+ t lymphocytes are found in the lichenoid infiltrate of lp, with a predominance of the latter cell type being present in established lesions (8-10) . the interaction between pathogenic t lymphocytes and basal keratinocytes is enhanced by increased expression of intercellular adhesion molecule(icam-1)by basal keratinocytes (11,12). (1) lecturer, department of oral diagnosis, college of dentistry, university of baghdad. ihc studies showed that the infiltrating cells in olp are predominantly t lymphocytes with very few b lymphocytes. several cytokines (13-15), adhesion molecules (16), and apoptosis-related molecules (17) are involved in its pathogenesis. neo-angiogenesis, together with a rich vascular proliferation, were reported to be essential factors in the pathogenesis of different types of o lp (18, 19) angiogenesis, which is the formation of new blood vessels, is an important component in many biological processes, whether physiological as in proliferating endometrium, corpus luteum formation and embryogenesis, or pathological including neoplastic, inflammatory, and degenerative conditions (20). in normal tissues, new vessel formation is dependent on a delicate balance between several different stimulatory and inhibitory factors; any change in this balance, weather physiological or pathological can result in acquisition of an angiogenic phenotype. several scientific studies (21,22) have verified the presence of neo-angiogenesis and its importance in a number of inflammatory pathologies such as rheumatoid arthritis, psoriasis, bronchial asthma, diabetic retinopathy, atherosclerosis, and alzheimer’s disease. the importance of angiogenesis in the pathogenesis of chronic inflammatory illnesses is through its allowing of better oxygenation and a greater contribution of metabolites to the proliferating tissue by the formation of new vessels, and through an increase in the turnover of the cells involved in the inflammatory process. (23) angiogenesis has been recognized as an important feature in chronic inflammation accompanies many autoimmune and j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of microvessels oral diagnosis 44 inflammatory conditions including olp. moreover, investigations have also shown a close relationship between angiogenesis and the activity of these diseases. therefore, it is necessary to elucidate the role of angiogenesis in the pathogenesis of olp to better understand its mechanisms and, better understanding of the etiopathological mechanism underlying olp will help in the development of new treatment strategies, as well as to manage persistent inflammation in patients showing poor response to conventional immunosuppressive drug regimes. (19) microvessel density (mvd, the number of micro vessels per mm2) is a commonly applied estimate of tumor angiogenesis and is widely accepted to play a role in the pathogenesis of some inflammatory conditions. cd34 monoclonal antibody is considered to be an appropriate marker to investigate the vascular endothelium (24, 25) and to quantify microvessel density (mvd) in inflammatory or neoplastic disorders because of its capability of staining the vascular endothelial cells. few studies have reported the importance of angiogenesis in o lp (18, 19). the purpose of this study was to evaluate the role of angiogenesis in the pathogenesis of olp, using cd34 stain to highlight the blood vessels in both normal and lichen planus affected oral mucosa for measuring the mvd as well as to evaluate the relation of this marker with the degree of inflammation materials and methods this is a retrospective study conducted at the oral pathology department, college of dentistry, baghdad university. a total number of 46 cases involved in this study. they were categorized into 2 groups as follow; group 1 (control group); consisted of 10 cases of apparently normal mucosa taking from subjects underwent tooth extraction or other dental procedures, those were subjected to classical 4-6 mm punch biopsy of normal looking oral mucosa(buccal or gingival) group 2 those with olp lesion 36 cases, which were collected either from the blocks of previously diagnosed cases from the archives of the department of oral and maxillofacial pathology and from surgical specialist hospital. those were asserted as; group 2 a; those with histopathological diagnosis of reticular type olp 20 cases group 2b; those with histopathological diagnosis of erosive type olp 16 cases the files of pts with olp were reviewed biopsies were fixed in formalin and embedded in paraffin wax. four micron thick sections from the paraffin embedded biopsies were stained by haematoxylin and eosin to verify the clinical diagnosis of lp for those with a clinical diagnosis of olp and to confirm the diagnosis of normal oral mucosa for the control group. the histopathological features of olp shows varying degrees of orthokeratosis and parakeratosis, the rete ridges may be absent or hyperplastic, but classically have seen tooth appearance. hydropic degeneration of basal cell layer and band like infiltration of t lymphocyte.civatte bodies may be seen (1) ihc staining was carried out using cd34 antibody. all blocks that collected from the archives of the department of pathology were cut at a thickness of 4 micron& were mounted on glass slides. sections were deparaffinized in xylene, &subsequently rehydrated with ethanol&water. the section then incubated with the primary monoclonal antibody at 4c overnight for cd34 (diluted 1:40). the bounded antibodies were detected by streptavidin-biotin complex. washing by pbs (phosphate-buffered saline). the sections were then counterstained with hematoxylin and the slides were observed under olympus research microscope identification of microvessels was indicated by cytoplasmic immunostaining of the endothelial cells with anti-cd34 monoclonal antibody. the entire section was scanned systematically by light microscopy at low magnification to identify the area with the highest number of stained microvessels(hot spots). then the vessels were counted in the 5 areas of hot spots at x400 magnification mvd was expressed as the average number of vessels in these areas (19). degree of inflammation was subjectively graded into mild, moderate, or severe according to density of mononuclear infiltrate data processing &statistical analysis was done by excel 2003(microsoft,seattle wa,usa) .the t student test was used to test the difference. chi square test for the association of mvd and inflammation results a total number of 46 subjects were included in this study. the age range of control group was 2550 years with a mean of 39.4 years, while the range for olp group was 28-60 years with a mean of 38.6 years with no statistically difference between olp cases and controls as regards the mean age j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of microvessels oral diagnosis 45 figure 1: oral lichen planus: ah & e x 400, b & cmarked newangiogenesis x200 d-x400 table1: mvd in different group groups minimum mvd maximum mvd mean +sd p value group1 (control) 15 24 19.5 p<0.001 group 2 a (reticular olp) 28 41 31.9 group 2 b (erosive olp) 36 65 48.375 table 2: mean mvd in different grades of inflammation in the lichen planus group mild (9) moderate (16) severe (11) mvd 26.33 ± 4.1 37.37 ± 3.94 52.45 ± 7.7 p<0.001 regarding sex distributions in the olp group, 24 patients (66.6%) were females & 12 patients (33.3%) were males while in the control group, there were 5 females (50%) & 5 males (50%) with significantly higher rates of females in patients of olp group compared with control group when all olp patients were regarded as a whole. in the present study, anti-cd34 antibodies were used for the determination of mvd. high cd34 staining was observed in the cytoplasm of the vascular endothelium of all specimens. most of the microvessel hot spots were located in the lamina propria (fig. 1) the mean mvd as determined by the mean number of cd34 positive vessels in hot areas for olp group was 39.2 (31.9 for reticular group & 48.375 for erosive group), whereas the mean mvd for control group 19.5 so that there was statistically significant difference between olp group and the control group (pvalue<0.001) as shown in table 1 regarding the severity of inflammation, the mean of mvd was significantly increased as the degree of inflammation increased (p value<0.001) as shown in table 2 discussion angiogenesis is an important part in the inflammatory response that explains the persistence and chronicity of different autoimmune and inflammatory disorders including olp angiogenesis is a complex process characterized by the formation of new capillaries from the preexisting vascular network. this study revealed that females were more often affected than males was , this is in agreement with the study done by yas l.s in her b a c d j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of microvessels oral diagnosis 46 histopathological observation of 194 cases of lichen planus (26) and other previous studies (27,28) but it disagrees with the finding of sugerman etal. which showed that the females and males were affected equally. the current study showed that angiogenesis, as estimated by mvd using the endothelial cell markers cd34 is significantly increased in olp lesion group compared to the control group which agrees with many studies conducted by different authors (18,19).and also agrees with study done by mittal etal (29) this finding may be explained by the concept that angiogenesis could be an important step in the etiology and pathogenesis of olp furthermore in this study the mvd was significantly higher in olp lesion with erosive type compared to the reticular type and this finding is in accordance with similar observations in several different studies (18,19,29) the current study revealed that angiogenesis is significantly increased in olp as compared to normal oral mucosa (table 1), also in erosive olp as compared to reticular olp, this suggests that angiogenesis is one of the main contributing factors in the progression of olp it is still possible that the activity of angiogenic factors might be especially elevated at olp lesion sites. one hypothesis, to be tested for increased angiogenesis in these lesions is that some of the lesional cells switch to an angiogenic phenotype. the molecular basis of the angiogenic switch is not entirely clear but may involve an increase in angiogenesis stimulators, a decrease in angiogenesis inhibitors, or a combination of the two. although angiogenesis may not be the primary step in the pathogenesis of lp, understanding the pathways leading to angio-proliferation may help in finding novel therapeutic modalities for this common disease. the current results, demonstrated that there is a direct relationship between angiogenesis and different clinical presentations of olp and different degree of inflammation. since the increase of mvd offered the favorable environment and indispensable condition for the proliferation and transformation of epithelia in the lesions, these findings will be helpful in some extent to explain several important clinical observations. in summary, this study revealed that the aberrant angiogenesis and cd34 expression occurred in olp lesions, closely correlated to its clinical forms. the complex regulatory mechanisms of angiogenesis existing in different clinical forms of olp require further study to validate. our result supports the view that angiogenesis may be a future target for the management of different forms of olp angiogenesis has long been known to be closely linked to chronic inflammation, and it is a component of various chronic inflammatory diseases. however the exact pathological mechanism of olp is still not clear. most of the studies have not been able to demonstrate a direct relation between angiogenesis and olp. antiangiogenic drug is not commonly used in olp patients; it would reduce the dependency on corticosteroid drugs the proven role of angiogenesis in the pathogenesis olp and the resistant of some olp lesions to the conventional immunosuppressive therapy may govern the attention to new treatment strategies targeted angiogenesis, so that angiogenesis suppressor drug may play a role in the treatment of olp in conclusion, it suggests that angiogenesis may be an integral component associated with the development of the olp references 1. neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology. 3rd ed. philadelphia: wb saunder; 2009. 2. sugerman pb, savage nw, walsh lj, zhao zz, zhou xj, khan a, et al. the pathogenesis of 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(1) ahlam t. mohammed, b.d.s., m.sc. (2) abstract background: gasoline constituents and its derivatives had many hazardous effects on the general health of humans. thus, gasoline stations workers may be affected by different types of related diseases.this study was conducted to assess selected salivary elements and their relation with dental caries, oral hygiene status and periodontal diseases among gasoline stations workers in comparison with individuals have no regular exposure to gasoline. materials and methods: the study group consists of thirty male subjects with an age range (33-39) years who worked in different gasoline stations in different areas of baghdad city and thirty persons that matching in age and gender and not exposed to gasoline were selected as a control group. dental caries was recorded by lesion severity through the application of d1-4 mfs index of (manji et al). plaque index of silness and loe and calculus index of ramfjord were used for recording oral hygiene status. periodontal diseases were evaluated by using the gingival index of loe and silness and periodontal pocket depth of carranza. stimulated salivary samples were collected and chemically analyzed to determine the concentration of salivary calcium, phosphorous, iron, copper and lead ions. results: caries experience (dmfs) was higher among the study group compared with the control group with significant difference (p<0.05) for ds and highly significant difference (p<0.01) for d2. the mean values of plaque, calculus and gingival indices were significantly higher (p<0.01) among the study group than the control group and the mean value of periodontal pocket depth was significantly higher (p<0.05) among the study group. the levels of salivary calcium and phosphorous were lower among the study group compared with the control group with no significant difference between them; whereas iron, copper and lead levels were higher among the study group than the control group with highly significant differences (p<0.01) for both copper and lead. conclusion: dental caries and periodontal diseases revealed higher percentage of occurrence among the study group and salivary elements were found to have little effects on the oral health status. therefore, special oral health preventive and educational programs are needed for them. key words: gasoline, salivary elements,dental caries, oral hygiene status and periodontal diseases. (j bagh coll dentistry 2013; 25(3):125-129). introduction gasoline is the generic term for petroleum fuel used mainly for internal combustion engines. it is complex, volatile and flammable and contains over 500 saturated and unsaturated hydrocarbons. the variable mixture characteristics depend on crude oil origin, differences in process techniques and blades, season to season changes and the additives required meeting particular performance specifications. generally, a common gasoline formulation contains approximately (80-90%) hydrocarbons in addition to alcohols, ethers and additives (1). gasoline has many negative effects on the general health of humans depending upon both the amount and duration of the exposure. the major toxic risk of gasoline comes from breathing exhaust fumes, evaporative and refueling emissions rather than from occasional skin contact from spills (2), also personal habits and lack of protective measures at the workplace and lack of awareness about the effects of gasoline were reported to contribute in facilitating exposure to gasoline (3,4). (1) m. sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. saliva is an important fluid and plays an essential role in maintaining the integrity of the oral structure (5). recently saliva is a promising option for diagnosis of many systemic diseases through the evaluation of certain substances for each type of disease (6). as there are no available studies that investigate the relation between the exposure to gasoline constituents and its additives with the oral health status among the gasoline stations workers, so this study was conducted to increase the knowledge and to improve human oral health. materials and methods the study group includes 30 males who work at least five years in different gasoline stations in baghdad city. their ages were between 33-39 years and the age was recorded according to the last birthday (7). they were non-smokers with no history of serious medical problems, not received any medicaments in the last two weeks before examination and not wear any fixed, removal dental prosthesis or orthodontic appliance and their permanent residence were in baghdad city. the control group also includes 30 males that matching the study group in everything except they were not in contact with gasoline. dental examination and oral health assessments j bagh college dentistry vol. 25(3), september 2013 oral health status pedodontics, orthodontics and preventive dentistry126 were performed after the collection of the stimulated saliva and according to the basic method of oral survey of the who (8). caries experience was recorded using plane mouth mirror and dental explorer according to decayed, missing and filled surfaces index (dmfs). the diagnosis of the severity of dental caries was according to the criteria of manji et al (9) . radiographs were not taken because of the technical difficulties. dental plaque was assessed by using plaque index (pli) of silness and loe (10). gingival inflammation was assessed by using the gingival index by loe and silness (11). dental calculus was assessed according to criteria of ramfjord (12). the probing pocket depth was measured with calibrated periodontal probe (william's probe) according to criteria of carranza (13). the collection of stimulated salivary sample was performed following instruction cited by tenovuo and lagerlof (14). chemical analyses of the elements were carried out at the poisoning consultation center / specialized surgeries hospital. ca, cu and pb ions were determined using air-acetylene atomic absorption spectrophotometer (buck scientific, 210 vgp, usa) according to instrumental manufacturer’s specification (15). while inorganic phosphorous and iron were determined colorimetrically by the molybdenum-vanadata method (16) and by using readymade kit (biomaghreb, tunisia) for phosphorous and a readymade kit (biolabo, france) for iron . analysis of data was carried out using spss( version16). statistical tests used were student's t-test and pearson’s correlation coefficient. the confidence limit was accepted at 95% , p< 0.05 was regarded as statistically significant and p< 0.01 were regarded as highly significant. results result revealed that caries experience represented by dmfs index was higher among study group compared with control group, but the difference was statistically not significant (p>0.05). in both groups missing component of dmfs index represented the highest proportion. decayed surfaces value was significantly higher among the study group (p<0.05). although missing surfaces value was higher among study group compared with control group, but the difference was statistically not significant (p>0.05).while filled surfaces value was higher among control group compared with study group, but the difference was statistically not significant (p>0.05) table (1). results also showed that only d2 value was highly significant higher among study group compared with control group (p<0.01), while for the other grades, study group d1, d3 and d4 were higher than control group d1, d3 and d4 respectively, but the differences were statistically not significant (p>0.05) table (2). oral examination revealed higher mean values of plaque index, calculus index ,gingival index and periodontal pocket depth among the study group than the control group with statistically highly significant difference (p<0.01) except for ppd the difference was significant (p<0.05) table (3). table (4) showed that salivary calcium and phosphorous ions levels were higher among control group compared with study group, but the difference were statistically not significant (p>0.05). while iron ions concentration was higher among study group compared with control group, but the difference was statistically not significant (p>0.05). for copper and lead ions concentrations they were higher in study group than control group with statistically highly significant different between them (p<0.01). pearson’s correlation coefficient between caries experience and salivary elements concentrations showed that both groups have weak and statistically not significant correlations with caries experience where some of these correlations were positive while the others were negative table (5). table 1. caries experience among study and control groups. *significant (p<0.05), d.f =58 variable study group control group statistical test mean + sd mean + sd t-test p-value ds 10.43 5.53 7.00 5.81 2.34 0.023 * ms 14.50 12.75 10.30 8.78 1.48 0.143 fs 5.13 9.73 7.80 9.29 -1.1 0.282 dmfs 30.07 18.52 25.10 14.21 1.16 0.249 j bagh college dentistry vol. 25(3), september 2013 oral health status pedodontics, orthodontics and preventive dentistry127 table 2. caries severity among study and control groups variables study group control group statistical test mean + sd mean + sd t-test p-value d1 2.67 2.64 2.2 2.83 0.66 0.512 d2 5.1 3.91 2.67 3.04 2.68 0.009 ** d3 1.5 2.54 1.47 2.12 0.05 0.956 d4 1.17 2.84 0.67 2.85 0.68 0.499 **highly significant (p<0.01), d.f = 58 table 3. oral hygiene and periodontal indices among study and control groups. variables study group control group statistical test mean + sd mean + sd t-test p-value pli 1.27 0.61 0.88 0.45 2.75 0.008 ** cali 0.54 0.51 0.14 0.17 4.03 0.000 ** gi 0.94 0.53 0.6 0.39 2.78 0.007 ** ppd 1.88 0.75 1.5 0.35 2.54 0.014 * *significant (p<0.05), **highly significant (p<0.01), d.f = 58 table 4. salivary elements among study and control group variable study group control group statistical test mean + sd mean + sd t-test p-value ca (mg/dl) 3.86 2.13 4.12 0.9 -0.62 0.537 po4 (mg/dl) 4.89 1.77 5.18 2.69 -0.49 0.626 fe (µg/dl) 41.41 16.06 38.41 11.43 0.83 0.408 cu (µg/dl) 13.86 3.08 5.8 1.8 12.36 0.000 ** pb (µg/dl) 15.9 3.26 7.23 1.16 13.7 0.000 ** **highly significant (p<0.01), d.f = 58 table 5. correlation coefficients between salivary elements with caries experience discussion gasoline constituents and its additives had many effects on the general health of humans and as gasoline stations workers who pump gasoline are liable to exposed to the products present in the gasoline so they may have an increase in the risk for the development of many health disorders (17). as there is no previous iraqi studies concerning the effect of gasoline constituents and its additives on the oral health status, so this study was conducted. the sample consist of 30 males who worked at least five years at different gasoline stations in baghdad city to determine the effect of gasoline exposure on the oral health status. their ages were between 33-39 years to exclude the systemic effects which occur as a result of aging. they were non smokers and looking healthy and not take any medication in the last two weeks to exclude any effect on the oral health status except the effect of gasoline. regarding the difference in the caries susceptibility, finding of this study found that missing surface fraction in the current study was the highest proportion of the dmfs index in the both groups. ds fraction was higher than the fs fraction in the study group, while fs fraction higher than the ds fraction in the control group. this finding indicates that the study group did not received an optimal dental care and have poor dental health knowledge , in addition to the that, the study group showed higher caries experience compared with the control group which indicated by the higher d2 grade with highly significant difference and a significantly higher difference in the ds fraction. this could be explained by the poor oral hygiene among the study group as in the present study the study group had higher plaque and calculus deposits compared with the control group, since dental plaque plays an essential role in caries pathogenesis (18). variable study group control group ds dmfs ds dmfs r p r p r p r p ca -0.079 0.680 0.129 0.496 -0.176 0.352 0.001 0.998 po4 -0.122 0.521 0.231 0.220 0.052 0.784 0.137 0.472 fe 0.025 0.895 0.244 0.195 -0.356 0.053 -0.140 0.460 cu -0.015 0.937 0.002 0.990 0.105 0.582 -0.152 0.422 pb 0.060 0.754 0.101 0.595 -0.112 0.556 -0.097 0.609 j bagh college dentistry vol. 25(3), september 2013 oral health status pedodontics, orthodontics and preventive dentistry128 the other important factor that may affect caries experience is saliva through its constituents (19). electrolytes in the saliva especially calcium and phosphorous are necessary to maintain the integrity of the teeth and considered to be an important variable explaining the difference in caries experience (20). as high concentration of calcium and phosphorous in the saliva guarantee the ionic exchange that directed towards the tooth surfaces and resulting in posteruptive maturation. remineralization of carious tooth before cavitation is then possible, mainly due to the availability of calcium and phosphorous in the oral cavity (21). iron ions in the present study showed inverse correlation with dental caries indicated by dmfs, ds and all grades of dental caries in the control group this in agreement with other study (22). this indicated that when iron increased in saliva, dental caries decreased, so it act as cariostatic element in the saliva by the inhibition of gtfs enzyme produced by mutants streptococci, so it affect the growth and metabolism of microorganism on the teeth (23). lead ions considered a cariogenic element as its concentration increase in carious teeth compared with its concentration in the sound teeth with a highly significant difference between them (24). this is confirmed in the present study by a positive correlation with dental caries represented by dmfs, ds; however, the correlation was not reach the significance. it is essential to know that dental caries is a multi-factorial disease of which salivary composition represent only a fraction of all contributing factors, furthermore, salivary composition showed considerable variation since it depend on their present in the systemic environment which affected by the type of food, water, air and even drugs, also affected by the salivary flow rate, (25). in addition caries experience affected by other factors that is not involved in this study which include the diet and the cariogenic bacteria (26). in this study results shown that the study group have higher mean value of gingival inflammation with highly significant difference and higher periodontal pocket depth mean value with significant difference compared with the control group. this could be attributed to the poor oral hygiene which plays an important role in the etiology and progression of periodontal disease (27)as indicated by the higher plaque and calculus mean values among the study group compared with the control group with highly significant difference between them and since plaque and calculus is the causative factors for the development of gingival inflammation(28) so they are also the causative factors for the increase in the periodontal pocket depth as previous study find that the gingival inflammation plays an important role in the occurrence of periodontal pocketing (29). saliva may affect periodontal diseases as any changes in the salivary constituents will affect the pathogenicity of dental plaque; this in turn will affect the periodontal response. the results of this study revealed that both salivary calcium and phosphorous ions were higher among the control group compared with the study group, although the difference failed to reach the significance. this could be attributed to the absence of both calcium and phosphorous ions in the composition of gasoline (30) since calcium and phosphorous ions were found to be essential for the health of the bone including the alveolar bone (31). iron ions in this study was higher among the study group compared with the control group, but with no significant difference between them, this may be due to the addition of iron carboxyl to gasoline as antiknock agent, but it added in very small amount because it increases the engine wear due to its abrasive combustion product (32), so there is an exposure to small amount of iron ions. beside this effect, the study group also had a higher iron level because they had higher gingival inflammation than the control group with a highly significant difference between the two groups, this is in agreement with the study done by petrovich et al (33) who found that the salivary iron level was higher among persons with gingivitis than persons with normal gingival. regarding the copper ions, the present study revealed that the study group has higher salivary copper level compared with the control group, with highly significant difference between them. this could be attributed to the presence of copper ions in the gasoline as it is used as a metal deactivator which is effectively catalyze the oxidization of gasoline (32). other reason could be due to subjects exposed to gasoline may had liver dysfunction which lead to an increase in the plasma level of copper (34), and as salivary composition resembles to that of serum (35), so this will lead to an increase in the salivary copper level. lead ions also was evaluated in this study and found that the study group had higher salivary lead level compared with the control group, with highly significant difference between them. this may be due to the addition of tetraethyl lead as anti-knock agent to the gasoline (36). the higher level of both copper and lead ions may be attributed to that gasoline stations workers spend large part of the day exposed to gasoline, beside these workers did not use the preventive measures which include the using of proper personal protection which include the use of masks and gloves, use of ointment which reduce dermal exposure to gasoline and drinking of milk which retard the absorption of heavy metals, beside the poor health knowledge about the harmful effects of gasoline (37). j bagh college dentistry vol. 25(3), september 2013 oral health status 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(1) hussain f. al-huwaizi, b.d.s., m.sc., ph.d. (2) abstract background: the isthmus is a difficult area in the root canal complex to manage. the research aimed to evaluate the efficiency of three different obturation techniques (lateral condensation, eandq (thermoplasticized gutta percha system) and soft core (thermoplasticized core carrier gutta percha system)) to obturate the isthmus area of roots prepared by two different instrumentation techniques (rotary protaper universal and protaper next systems). material and method: sixty freshly extracted teeth were randomly divided into two main groups (a and b) of 30 teeth each. group a was prepared by rotary protaper universal whereas group b was prepared by protaper next system. each main group was then randomly subdivided into three subgroups of 10 teeth each, to be obturated with the three obturation techniques. all specimens were then placed in cold cure acrylic mold just from the side of the crown leaving the root unmolded to facilitate the sectioning process, then three sections were obtained from each specimen by using microtome at 2, 6 and 10 mm from the apex. each section was viewed under stereomicroscope(40x) and imaged with digital camera(4x). each image was managed with image j program to calculate the surface area of the whole isthmus and that of the gutta percha and/or sealer extended into the isthmus so the collected data represented the percentage of extension degree of gutta percha and /or sealer into the isthmus(edgs). results: the highest mean value of (edgs) was evident with soft core technique in the apical area and was significantly higher than that of the eandq and lateral condensation techniques. conclusion: under the conditions of this study, soft core system showed a higher efficiency in obturating the isthmus area than the other obturation techniques. keywords: isthmus, protaper next, soft core, eandq, image j program. (j bagh coll dentistry 2016; 28(2):14-18). introduction the aim of endodontic therapy is the removal of all tissues whether vital or necrotic, microorganisms, and microbial byproducts from the root canal system. although this may be accomplished by chemomechanical debridement (1), it is difficult do it efficiently (2) because of the complex nature of root canal anatomy (3). isthmi, fins, webs, and other irregularities within the root canal often harbor tissue, microbes, and debris after instrumentation (4). the isthmus is a narrow connection between two root canals that contains pulp tissue (5). it is also known as corridor (6), lateral interconnection (7) and transverse anastomosis (8). isthmi may be present in all types of roots in which two canals are normally found, including the mesial roots of maxillary and mandibular molars, the distal root of mandibular molars, the maxillary and mandibular first and second premolars and mandibular incisors. instrumentation of the root canal system must always be assisted by irrigation to remove pulp tissue remnants and other loose material. (1) m.sc student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor. department of conservative dentistry, college of dentistry, university of baghdad. the efficacy of an irrigation delivery system is dependent not only on its ability to deliver the irrigant to the apical and non-instrumented regions of the canal space and to create a current strong enough to carry the debris away from the canal systems but also on the ability of the irrigating solutions to dissolve both organic and inorganic matter (9, 10). irrigation is essential for eliminating or reducing the number of bacteria in an infected root canal. few studies have focused on filling of the isthmus area by obturation. so the present study will focus the light on the efficiency of three different obturation techniques to obturate the isthmus area of roots prepared by three different instrumentation techniques. materials and methods sixty freshly extracted mandibular first molar teeth with their mesial roots having two canals and mature apices were selected for this study from several dental treatment centers. the age of the donors of the teeth was in the range of 25-35 years of age. the gender, pulpal status and reason for extraction were not considered, and criteria for teeth selection included the following: j bagh college dentistry vol. 28(2), june 2016 evaluation of the restorative dentistry 15 1. patent apical foramen. a #15 file had to bind to the working length. 2. roots were devoid of any resorptions, cracks or fractures. 3. the mesial roots were not less than 12 mm in length from the apex up to the canal orifice. after extraction, all the teeth were stored in 0.1 % thymol solution at room temperature. any soft tissue remnants on the root surface were removed with sharp periodontal curette. using a diamond disc bur with a straight handpiece and water coolant, each tooth was hemisectioned to separate the roots. the mesial half of the crown remained attached to the mesial root to facilitate grasping of the tooth during sectioning process by the microtome device. the access opening was prepared and the pulpal tissue was removed by using barbed broach. then the exact location of the apical foramen and the patency of the canals were verified by insertion of a no. 10 k-file into the canal and advancing until it could be visualized at the apical foramen. the correct working length was established by subtracting l mm from this measurement. all specimens were then randomly divided into two main groups (a and b): group a: thirty teeth were prepared by rotary protaper universal system. group b: thirty teeth were prepared by protaper next system. all the canals in both of the groups were agitated by using the endoactivator irrigation device in the presence of naocl for 30 seconds for each canal. each main group was then randomly subdivided into three subgroups: subgroups a1 and b1 were obturated with soft core thermoplasticized cones. subgroups a2 and b2 were obturated with lateral condensation subgroups a3 and b3 were obturated with eandq thermoplasticized gutta percha obturation system. ah26 sealer was used in all the groups. after obturation, the roots were placed in a moist container in an incubator for 37º c for 1 week for aging. all the samples were then sectioned by using microtome device under water coolant. the sections were made at three levels 2, 6 and 10 mm from the apex. each sectioned piece was then viewed under a stereomicroscope with a magnification power of (40x) and images were then captured with a digital camera (4x) and each image was analyzed by using (image j) program to calculate the percentage of extension degree of gutta percha and / or sealer into the isthmus. results the collected data represents the means of percentages of the extension degree of gutta percha and/or sealer (edgs) into the isthmus area (in relation to the whole surface area of the isthmus) in each section area (apical, middle and coronal) for both groups. the highest mean values were found in the apical area followed by middle and then coronal area in both groups. the soft core subgroups (a1 and b1) showed the highest mean values of edgs into the isthmus followed by eandq (a3 and b3) and finally by cold lateral condensation (a2 and b2). anova and lsd tests were used for statistical analysis. figure 1: bar chart of group a (instrumentation with protaper universal system) 0 50 100 a1 a2 a 3 coronal middle apical j bagj bagh college dentistry restorative dentistry statistical analysis of group a presented a non significant difference in the soft core subgroup (a1) and significant difference in the e system (a2) and cold lateral condensation technique (a3) (table 1). significan microscopical pictures of the cross section of the obturated teeth are shown in figures 3 subgroups subgroups figure 3: cross section of an obturated h college dentistry restorative dentistry figure 2: statistical analysis of group a presented a non significant difference in the soft core subgroup (a1) and significant difference in the e system (a2) and cold lateral condensation technique (a3) (table 1). significant difference for all the subgroups. microscopical pictures of the cross section of the obturated teeth are shown in figures 3 table 1: statistical analysis of data of group a (protaper universal system) subgroups f a1 2.934 a2 7.128 a3 13.735 table 2: statistical analysis of data of group b (protaper next system) subgroups f b1 10.944 b2 21.955 b3 84.021 figure 5: cross section of an obturated tooth with 50 100 figure 3: cross section of an obturated tooth with h college dentistry restorative dentistry bar chart of group b statistical analysis of group a presented a non significant difference in the soft core subgroup (a1) and significant difference in the e system (a2) and cold lateral condensation technique (a3) (table 1). group b presented non t difference for all the subgroups. microscopical pictures of the cross section of the obturated teeth are shown in figures 3 table 1: statistical analysis of data of group a (protaper universal system) anova test f-test d.f. 2.934 29 7.128 29 13.735 29 table 2: statistical analysis of data of group b (protaper next system) anova test f-test d.f. 10.944 29 21.955 29 84.021 29 igure 5: cross section of an obturated tooth with 0 50 100 b1 figure 3: cross section of an obturated with soft core cones. h college dentistry vol. 2 bar chart of group b (instrumentation with protaper next system) statistical analysis of group a presented a non significant difference in the soft core subgroup (a1) and significant difference in the eand system (a2) and cold lateral condensation group b presented non t difference for all the subgroups. microscopical pictures of the cross section of the obturated teeth are shown in figures 3-5 for all table 1: statistical analysis of data of group a (protaper universal system) anova test p-value 0.070 (ns) 0.003 (hs) 0.000 (hs) table 2: statistical analysis of data of group b (protaper next system) anova test p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) igure 5: cross section of an obturated tooth with b1 b2 figure 3: cross section of an obturated soft core cones. vol. 28(2), june 16 (instrumentation with protaper next system) statistical analysis of group a presented a non significant difference in the soft core subgroup andq system (a2) and cold lateral condensation group b presented non microscopical pictures of the cross section of 5 for all the subgroups. figure 3 shows the complete obturation system. isthmus area with no gutta percha when obturated with cold lateral condensation technique. the eand the isthmus by gutta pe table 1: statistical analysis of data of group a (protaper universal system) apical-middle 0.005 (hs) 0.000 (hs) table 2: statistical analysis of data of group b (protaper next system) apical-middle 0.188 (ns) 0.012 (s) 0.000 (hs) igure 5: cross section of an obturated tooth with b3 figure 3: cross section of an obturated figure 4: cross section of an obturated june 2016 (instrumentation with protaper next system) the subgroups. figure 3 shows the complete obturation of the isthmus area by the soft core system. figure 4 shows the entrance of the sealer in the isthmus area with no gutta percha when obturated with cold lateral condensation technique. the andq system showed incomplete obturation of the isthmus by gutta pe table 1: statistical analysis of data of group a (protaper universal system) lsd test middle apical 0.005 (hs) 0.002 (hs) 0.000 (hs) 0.000 (hs) table 2: statistical analysis of data of group b (protaper next system) lsd test middle apical 0.188 (ns) 0.000 (hs) 0.012 (s) 0.000 (hs) 0.000 (hs) 0.000 (hs) igure 5: cross section of an obturated tooth with eand figure 4: cross section of an obturated tooth with (instrumentation with protaper next system) the subgroups. figure 3 shows the complete of the isthmus area by the soft core figure 4 shows the entrance of the sealer in the isthmus area with no gutta percha when obturated with cold lateral condensation technique. the q system showed incomplete obturation of the isthmus by gutta pe table 1: statistical analysis of data of group a (protaper universal system) lsd test apical-coronal middle 0.002 (hs) 0.000 (hs) table 2: statistical analysis of data of group b (protaper next system) lsd test apical-coronal middle 0.000 (hs) 0.000 (hs) 0.000 (hs) andq obturation system apical middle coronal figure 4: cross section of an obturated tooth with cold lateral condensation technique evaluation (instrumentation with protaper next system) the subgroups. figure 3 shows the complete of the isthmus area by the soft core figure 4 shows the entrance of the sealer in the isthmus area with no gutta percha when obturated with cold lateral condensation technique. the q system showed incomplete obturation of the isthmus by gutta percha (figure 5). table 1: statistical analysis of data of group a (protaper universal system) middle-coronal 0.725 (ns) 0.464 (ns) table 2: statistical analysis of data of group b (protaper next system) middle-coronal 0.003 (hs) 0.001 (hs) 0.105 (ns) q obturation system. middle coronal figure 4: cross section of an obturated cold lateral condensation technique. evaluation of the the subgroups. figure 3 shows the complete of the isthmus area by the soft core figure 4 shows the entrance of the sealer in the isthmus area with no gutta percha when obturated with cold lateral condensation technique. the q system showed incomplete obturation of rcha (figure 5). coronal coronal figure 4: cross section of an obturated cold lateral condensation the j bagh college dentistry vol. 28(2), june 2016 evaluation of the restorative dentistry 17 discussion the main goal of endodontic therapy is to clean the entire pulp cavity and fill it with aninert filling material. but such a goal could not be easily achieved because there are several challenges that may impair the success of endodontic treatment. cambruzzi and marshall found that the incidence of isthmus was around 30% in mandibular premolar, 60% in mesiobuccal roots of maxillary first molar with two canals (11), while another study found that, the prevalence of isthmuses in the mesial root of mandibular molars has been observed to be as high as 80% (8), so because the root canal system has such complex anatomy, it is difficult to shape and clean the root canal completely. lee et al. said that the isthmuses and irregularities have been shown to be inaccessible to conventional hand and rotary instrumentation (12). luebke et al. concluded that 60% of endodontic failures are caused by incomplete obturation of the root canal, untreated canals, accessory canals and the presence of an isthmus (13). therefore; in this study we tried to find which obturation technique may have the ability to fill the isthmus better than the other techniques. although, cold lateral condensation was considered the golden standard in endodontics, weller et al in 1997 found that cold gutta-percha techniques rely on a root canal sealer to overcome the problem of the accessory anatomy, as the core filling material will not move out of the main canal. voids, spreader tracts, incomplete fusion of the gutta-percha cones, and lack of surface adaptation have been reported (5). budds et al. found that injectable, heated gutta-percha technique were found to be significantly superior to lateral condensation and had a better adaptation to the three-dimensional root canal system (14). carrier based system (soft core) was used in this study because it was expected that it has improved ability to penetrate the isthmus for considerable distances, improving the quality and durability of the rct. (ah26) sealer was used in this study because it has a good sealing ability by incorporating resin monomer into the sealer. ah26 exhibit very low shrinkage during setting and has shown long term stability and strong adhesive property (9). the highest mean values of the edgs were obtained in the apical part, while the lowest mean values were obtained in the coronal part. two factors may interpret this finding 1the surface area of isthmus is increased considerably from the apical to coronal area and both canals are being closer to each other in the apical area than in other area, so the smaller the surface area of isthmus the higher the edgs. 2the presence of smear layer or dentin chips inside the isthmus adversely affects edgs into the isthmus. however, the results of present study are supported by the results of rodig et al. (15) who showed that more smear layer removal at apical region is effective when endoactivator system was used and our results came in agreement with that of kadhom and al-hashimi (16) who found that the apical area was cleaner than middle and coronal area and protaper universal system has a better cleaning ability than revo s and twisted file especially in the apical area. this study disagrees with that of arvaniti and khabbaz (17), who showed that the smear layer was not removed, especially from the apical part of the canals. the highest mean value of edgs into the isthmus area was obtained in the sub group of soft core obturation technique, while the lowest mean value was obtained in the sub group of cold lateral condensation obturation technique. the superiority of soft core system was because 1it is a type of thermoplasticized gutta percha and this preheated soft core cone was introduced into the canal by single penetration method, so the presence of a core may act as a piston and enhances the penetration ability of gutta percha and sealer into the isthmus. 2the soft core is an alpha type gutta percha which has a lower viscosity and higher flowabilty, sealability and adaptability than that of eandq and lateral condensation. our result coincided with that of deus et al. (18) who found that the core carrier gutta-percha system produced significantly higher percentage of gutta-percha-filled area than lateral condensation and system b techniques and with that of dulac et al. (19) who concluded that the core carrier based gutta percha had the ability to fill the lateral canals with gutta percha better than other five systems especially in the apical area. (eandq) subgroups were lower than that of soft core and higher than that of lateral condensation subgroups. these results may be related to several causes which are: 1-the pressure applied on the lateral walls during this technique is lower than that of other techniques. 2as the pellet of the eandq system is made in beta form gutta percha , so it has lower ability to penetrate deeply into the isthmus compared with that of soft core system because of the beta form has higher viscosity and lower flowability, sealability and adaptability than that of alpha form. j bagh college dentistry vol. 28(2), june 2016 evaluation of the restorative dentistry 18 3-the shrinkage or contraction after setting of the beta form gutta percha( eandq) system is higher than that of alpha form ( soft core ) (20). 4the gutta percha of eandq will become cold inside the canal faster than that of soft core system and there will not be enough time to penetrate deeply into the isthmus in comparison with soft core system. this result coincided with that of the study performed by mahdi and kuba (21). in general speech, the subgroups that were prepared by protaper next showed better results than those prepared by protaper universal. the protaper next files have a bilateral symmetrical rectangular cross section with an offset from the central axis of rotation. however, van der vyver and scianamblo (22) found that some of the advantages of this design were that: 1-it ensures debris removal in a coronal direction. 2-the swaggering (asymmetric) rotary motion of the instrument initiates activation of the irrigation solution. 3-every instrument is capable of cutting a larger envelope of motion (larger canal preparation size) and as a result, smaller surface area of isthmus and higher percentages of edgs. in conclusion, no one of the obturation material can fill isthmus completely. however; soft core obturating system was the best to fill an isthmus in all areas (apical, middle and coronal) followed by eandq system and finally by cold lateral condensation. references 1sjogren u, hagglund b, sundqvist g. factors affecting the long-term results of endodontic treatment. j endod 1990; 16: 498–504. 2fariniuk lf, baratto-filho f, da cruz-filho am. histologic analysis of the cleaning capacity of mechanical endodontic instruments activated by the endoflash system. j endod 2003; 29:651–3. 3peters oa, laib a, reuegsegger p. three dimensional analysis of root canal geometry using high resolution computed tomography. j dent res 2000; 79: 1405–9. 4paqu f, laib a, gautschi h. hard-tissue debris accumulation analysis by high resolution computed tomography scans. j endod 2009; 35: 1044–7. 5weller nr, niemczyk sp, kim s. incidence and position of the canal isthmus. part 1. mesiobuccal root of the maxillary first molar. j endod 1995; 21: 380–3. 6green d. double canals in single roots. oral surg 1973; 35: 689. 7pineda f. roentgen graphic investigation of the mesiobuccal root of the maxillary first molar. oral surg 1973; 36: 253. 8vertucci fj. root canal anatomy of the human permanent teeth. oral surgery oral medicine oral pathology 1984; 58: 589-99. 9boutsioukis c, lambrianidis t, kastrinakis e. irrigant flow within a prepared root canal using various flow rates: a computational fluid dynamics study. int endod j 2009; 42: 144–55. 10tay fr, gu ls, schoeffel gj. effect of vapor lock on root canal debridement by using a side vented needle for positive-pressure irrigant delivery. j endod 2010; 36: 745–50. 11cambruzzi jv, marshall fj. molar endodontic surgery. j canad dent assoc 1983; 1: 61-6. 12lee sj, wu mk, wesselink pr. the effectiveness of syringe irrigation and ultrasonics to remove debris from stimulated irregularities within prepared root canal walls. inter endod j 2004; 37:672-8. 13luebke rg, glick dh and ingle ji. indications and contraindications for endodontic surgery. oral surgery, oral medicine, oral pathology 1964; 18: 97113. 14budd cs, weller rn, kulild jc. a comparison of thermoplasticized injectable gutta-percha obturation techniques. j endod 1991; 17: 260–4. 15rödig t, döllmann s, konietschke f, drebenstedt s, hülsmann m. effectiveness of different irrigant agitation techniques on debris and smear layer removal in curved root canals: a scanning electron microscopy study. j endod 2010; 36: 12: 1983-7. 1. 16-kadhom th, al-hashimi wn. the efficiency of different instrumentation systems for cleaning ovalshaped root canals (an in vitro study). j coll dent 2013; 25(1). 16arvaniti is, khabbaz mg. influence of root canal taper on its cleanliness: a scanning electron microscopic study. j endod 2011; 37 (6): 871-4. 17de-deus g, gurgel-filho ed, magalhães km, coutinho-filho t. a laboratory analysis of guttapercha-filled area obtained using thermafil, system b and lateral condensation, int endod j 2006; may: 39(5): 378-83. 18dulac ka, nielsen cj, tomazic tj, ferrillo pj jr, hatton jf. comparison of the obturation of lateral canals by six techniques. j endod 1999; may: 25(5): 376-80. 19meyer km, kollmar f, schirrmeister jf, schneider f, hellwig e. analysis of shrinkage of different guttapercha types using optical measurement methods, schweiz monatsschr zahnmed 2006; 116 (4): 356-61. 20mahdi ja, kuba ms. comparison of apical sealability of three obturation techniques (an in vitro study). mdj 2012; 9(2): 130-6. 21van der vyver pj, scianamblo. clinical guidelines for the use of protaper next instruments: part one. endod practice 2013; 16(4): 33-40. khulood f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry126 evaluation of frictional forces generated by different brackets and orthodontic wires khulood a. almakhzomi, b.d.s., h.d.d. (1) nidhal h. ghaib, b.d.s., m.sc. (2) abstract background: sliding mechanics is widely used during orthodontic treatment. one of the disadvantages of this mechanics is the friction generated at the bracket/archwire interface, which may reduce the amount of desired orthodontic movement obtained. the aim of the present in vitro study was to evaluate and compare the static frictional forces produced by two passive self-ligating brackets stainless-steel and hybrid and two conventional brackets stainless-steel and monocrystal ligated with stainless-steel ligature wire at two degrees of torque(zero and twenty) under dry condition. materials and method: one hundred and sixty brackets were used in this study divided into four groups each group consisted of forty brackets these are: two self-ligating (stainless-steel and hybrid) while the two conventional types are the (stainless-steel and monocrystal).twenty of each group examined with 0.016"x0.022"archwire, ten at 0˚ torque and ten at 20˚ torque while the other twenty of each group examined with 0.019"x0.025", ten at 0˚ torque and ten at 20˚ torque. results: there was a significant different between all groups except in case when self-ligating brackets (both types) ligated to both wires at 0˚torque there was no significant difference. conclusions: the selfligating brackets produce significantly lower static friction than the conventional types at both degrees of torque. there was no significant different between both self-ligating brackets at0˚torque while at 20˚ torque the stainlesssteel self –ligating produce lower static friction than the clear self-ligating type. keywords: static, friction, self-ligating, conventional, torque. (j bagh coll dentistry 2013; 25(special issue 1):126-131). introduction the appearance of fixed orthodontic appliances has always been of particular concern in orthodontic treatment. in the 1970s, attempts to produce brackets from different aesthetic materials included the use of plastic brackets that were injection molded from the aromatic polymer polycarbonate. problems reported included crazing and deformation as well as stains and odors1. even alternative composite brackets made of chopped glass fibers did not change these problems; it was nearly ten years before ceramic brackets became available for orthodontic applications. the ceramic brackets available nowadays are made of alumina (al2o3) either in polycrystalline or monocrystalline forms, the manufacturing process of monocrystalline brackets results in a purer structure, a smoother surface, and a considerably harder substance than the fabrication of polycrystlline brackets2. the proper magnitude of force during orthodontic treatment will result in optimal tissue response and rapid tooth movement3therefore orthodontic movement should be impressed with low forces4, thus ensuring treatment efficiency in respect of biologic principles5. (1) master student. department of orthodontics. college of dentistry. university of baghdad. (2) professor. department of orthodontics. college of dentistry. university of baghdad during mechanotherapy involving movement of the bracket along the wire, friction at the bracket-archwire interface might prevent attaining optimal force levels in the supporting tissues 3. in orthodontics, a tooth subjected to sliding motion along the archwire is alternately inclined and uprighted, moving in small increments therefore, space closure depends more on static than kinetic friction6. the search for a bracket system with a low frictional resistance resulted in the development of self-ligating brackets, although the first selfligating bracket was the russell lock 7. manufacturers and orthodontists have shown renewed interest in the development of selfligating brackets since the mid-1970s. two different types of self-ligating brackets were produced: those with a spring clip that pressed actively against the archwire, called active selfligating such as the speed bracket, and passive self-ligating brackets, like activa bracket whose self-ligating clip did not press against the wire 2. the attempt to combine the benefits of both types of brackets, an acceptable aesthetic appearance for the patient and low friction for adequate clinical performance, resulted in the development of self-ligating aesthetic brackets such as the opal, a new glass filled nickel free polycrystaline self ligating aesthetic bracket2 . the present study has been performed, because there was no previous iraqi study on aesthetic brackets whether conventional or selfligating, at the same time there was no previous iraqi study measured friction with torque. j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry127 materials and methods the sample(brackets and tubes) one hundred and sixty upper right central incisor brackets divided into four groups were used in the present study, each group include forty brackets, all types are pre-adjusted roth type (incorporating +12° torque and +5° angulation) and have 0.022" slot width (orthoclassic company, usa). these are: 1self-ligating stainless-steel 2self-ligating clear 3conventional stainless-steel 4 conventional sapphire. one hundred and sixty buccal tubes edgewise type (dentarium company, germany) two types of wires has been used in this study 0.016"x 0.022" and 0.019"x 0.025" stainless-steel archwires. friction generated by the experimental model consisting of one upper right central incisor bracket (which chosen according to8). twenty brackets of each type were bonded with a composite to a plastic bars, each bar dimensions were 10x10x100 mm, each one had a line drawn parallel to its long axis to ensure the straightness of the bracket slot to the bar. two brackets of the same type fixed to the plastic bar one on each side by using a piece of 0.0215″ x 0.025″ straight stainless-steel archwire that bend into l-shape used to align the brackets this guide allowed the slot axis of the bracket to be perpen-dicular to the plastic bar, so the brackets fixed by using the l-shape wire had 0˚ torque and 0˚tip, two brackets of the same type fixed to the plastic bar one on each side by using this wire (guide) (figure 1), after the fixation of the brackets another piece of 0.0215″ x 0.025″ straight stainless—steel archwire used to fix the buccal tubes by inserting two tubes into this piece ,then the two ends of this tube ligated into the brackets at each side of the plastic bar to ensure the vertical parallelism of these tubes to the brackets and the bar, each tube fixed at a distance of ten millimeter from each bracket (figure 2) . ten brackets of each group fixed in this way tested with 0.016"x 0.022" and the other ten tested with 0.019"x 0.025"archwires. the other twenty brackets of each type bonded to the plastic bar by using another piece of 0.0215″ x 0.025″ straight stainless-steel archwire that bend into l-shape and the its vertical arm which was perpendicular to the bar bent to create a twenty degree angle with its horizontal arm, so the angle formed between the archwire and the bar became twenty degree(figure 3) ,then this archwire would be used to align the brackets on the plastic bar in this case the bracket slot would be tilt exactly twenty degree to the plastic bar in anterio-posterior direction (figure 4)which mean the bracket slot had a twenty degree torque in relation to the plastic bar,two brac-kets of the same type fixed to the plastic bar one on each side by using this wire (guide), then the two tubes fixed on the same bar, each one at a distance of ten millimeter away from each bracket on that bar as explained previously. ten brackets of each group fixed in this way tested with 0.016"x 0.022" and the other ten tested with 0.019"x 0.025"archwires. a new bracket and ten centimeter length archwire used for each test run to prevent any distortion of the bracket slot or archwire surface. each testing archwire bent into a key hole bend at one end that was attached to the to the assembly that was clamped by the load cell of instron machine, and seated in the slot of one bracket and pass through one tube at one end of the bar after it was degreased with ethanol to remove oil and dust as factors can affecting frictional resistance 9,10 and ligated either with the ligature wire tightened first then untwisted 90° to become slackened and to allow the archwire to slide freely, and then cut the access leaving a small part of it for the conventional bracket11,12,13,14, and with the solid labial slider by rotating the slide downward with a special tool into the slot-open position , it then rotated upward with finger pressure to entrap the archwire in a passive configuration for the self-ligating bracket , after the looped end of the wire was attached to the assemb-ly that was clamped by the load cell of instron ma-chine , the bottom of the plastic bar was clamped by the lower fixed crosshead of the instron machine. friction generated by the experimental model consisting of one upper right central incisor bracket (which chosen according to 8, the archwire and the ligation method was tested on the instron h50kt tinius olsen testing machine with a load cell of 10 n 8,15 and speed of 6 mm/minute 8. this arrangement allowed the wire to move along the bracket and tube on one side of the plastic bar as an axial tensile force was applied by the instron’s load cell 8. in the same time, a computer connected to the testing machine displayed a graph showing peak force variation and recording the frictional resistance force generated on every 0.01mm distance of the tested wire for everytraction test over a distance of 12 mm, the maxim-um frictional resistance force generated in newton was noted at the beginning of the movement and then the graph was declined j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry128 slightly, the newton then converted to grams by the following equation: friction in gram = [friction in (n) ÷ 9.8] x 1000 all measurements were performed under dry conditions at room temperature of 25 ± 2 degrees centigrade 8. a total of one hundred and sixty tests were carried out (10 tests for each group). results the data collected from the present study had been analyzed and the descriptive statistics were performed for all the variables measured. these statistics included mean, standard deviation, standard error, minimum, and maximum values, these values were displaced in table (1). as shown in table (1), self-ligating stainlesssteel brackets showed the lowest measurement level of static frictional force when coupled with both wires at both degrees of torque and there was a very high significant different between all bracket types this was followed by the selfligating clear, convention-nal stainless-steel and then the conventional monocrystal. table 1: descriptive statistic of different brackets on 0.016”×0.022"and 0.019”×0.025" s.s. wires the measurements of friction were in grams, s.s. = stainlesssteel. a one way analysis of variance was carried out for comparison among brackets self-ligating stainless steel, self-ligating clear, conventional stainless steel and conventional monocrystal, the tests showed very high significant differences in static frictional forces (p≤0.001) the least significant difference (lsd) method, at a significance level of p <0.05, was used with the purpose of identifying significant differences between the combinations used in the study. there was a significant difference (p < 0.05) between the static frictional means of the self ligating stainless steel brackets with other brackets,except for the self-ligating clear there was no significant difference (p>0.05) between these brackets when coupled with both wires at 0˚torque,while in all other cases the self-ligating stainless-steel brackets produce the lowest static friction, then the self-ligating clear which was followed by the conventional stainless-steel and lastly the highest friction was recorded by the conventional monocrystal in all types of combinations. the0.016"x 0.022" archwire also produce lower static friction than the0.019"x 0.025" in all types of bracket combinations. in the same time we can detect than when torque increase the static friction increased in all types of bracket wire combinations. all these results summarized in figure (5). discussion the influuence of different factors on friction the readings obtained from the instron testing machine for each combination represented the outcome of the interaction of the bracket, arch wire and ligature, which makes it difficult to identify the effect of each variable (bracket, arch wire and ligature) separately, therefore in this study we tried to evaluate the effect of each variable separately by making other variables constants. the results of the present study indicate that there were a significant different between the static friction of all combinations except in case of both self-ligating brackets when combined with both wire at 0˚ torque, on the bases of biomechanical principles, one explanation for this finding that there was no actual binding between the wire and the bracket slot in case of 0˚ torque. bracket type no. wire size torque (º) min max mean sd se self-ligating s. s. 10 0.016”×0.022” 0 1.42 1.776 1.64 0.13 0.055 10 0.016”×0.022” 20 192.857 214.286 198.776 7.85 3.206 selfligating clear 10 0.016”×0.022” 0 1.73 2.14 1.9 0.16 0.068 10 0.016”×0.022” 20 240.81 266.32 251.87 9.9 4.042 conventional s.s. 10 0.016”×0.022” 0 91.73 95.91 94.18 1.43 0.58 10 0.016”×0.022” 20 317.3 330.61 323.29 4.34 1.77 conventional monocrystal 10 0.016”×0.022” 0 108.2 111.22 109.54 1.03 0.42 10 0.016”×0.022” 20 325.51 355.10 341.66 11.38 4.649 self-ligating s. s. 10 0.019”×0.025" 0 2.031 2.857 2.43 0.33 0.1364 10 0.019”×0.025" 20 274.490 330.612 305.95 23.12 9.439 self-ligating clear 10 0.019”×0.025" 0 6.73 7.95 7.44 0.47 0.19 10 0.019”×0.025" 20 328.57 408.16 373.63 28.28 11.54 conventional s. s. 10 0.019”×0.025" 0 117.34 135.71 125.85 6.47 2.643 10 0.019”×0.025" 20 407.14 467.34 438.027 25.87 10.56 conventional 10 0.019”×0.025" 0 151.02 178.57 166.15 9.38 3.831 monocrystal 10 0.019”×0.025" 20 486.735 530.61 509.405 15.454 6.309 j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry129 the influence of bracket jeometry the self-ligating brackets always produce lower static friction than the conventional counterpart did this is related to the fact that in the conventional type apply a force to the archwire pushing it against the depth of the slot, thus increasing friction. this finding agree with many researches 2,3, 1619,but didn’t agree with 20,21 this may be related to the type of the bracket which is active type in both studies. this also didn’t agree with 22-24 this maybe because they made their tests on typodonts in the presence of rotation, angulation, and torque in the pretreatment typodont models which also increase frictional resistance; attributing to binding rather than classic friction. the influence of torque degree according to the results gained from this study, the static friction is always increased for all bracket wire combination when torque increased from 0˚to 20˚ angle, this is related to the fact that 20˚ angle torque exceed the third order angle clearance that lead to increase the binding between the wire and bracket slot. reportedly, the third-order clearance for a fully drawn, 0.019"× 0.025" wire in a 0.022" is close to 10 degree 25. this agree with 17,26,27,however, the selflgating brackets still have a significantly less frictionl force than the conventional brackets in spite of increase in the torque , this finding agree with 28, but this finding disagree with 29, in their study they use active self-ligating brackets they found that with the increase of torque degree, the self-ligating brackets displayed the greatest increase in frictional resistance which is possibly a result of magnified normal forces from its active self-ligation and asymmetrical clip. the influence of wire dimensions the results of the present study revealed that, there was a wide range of variation in the mean values of static friction between the 16"x22" and19"x25" wires when coupled with different brackets, self-ligating stainless-steel bracket has the lowest static friction followed by clear selfligating bracket which was followed by conventional stainless-steel and lastly the highest friction was recorded by clear conventional bracket, but always the 16"x22" wire has lower friction than the 19"x25" wire when both coupled with the same bracket, the same ligature method and the same degree of torque, on the bases of this comparison we conclude that the friction will increase as the archwire increase this is in agree with18,30-32. according to 33the influence of the wire size on friction increases because thicker wires fulfill the bracket slot and the amount of force needed to cause orthodontic tooth movement is also increased. generally, friction appears to be more when wire diameter increase in all of the previous studies. this didn’t agree wih 2,34,which may be due to the experimental set-up of their study in which there was tipping that increase the binding between the wire and bracket . in the present study the static friction increase with icreasing the wire dimension, but there was only one exception, that there was no significant difference between the two wires when coupled with the selfligating brackets (both types) when the torque was zero degree. on the bases of biomechanical principles, the explanation for this finding is also related to the fact that there is no actual contact (binding) between these wires and the slot of the brackets, this is related to the fact that the bracket slot is bigger than both wires ,so there was no binding between these wires and self-ligating brackets at zero degree torque. the influence of bracket material in the present study , the aesthetic bracket had higher frictional force when compared with the stainless-steel bracket when used with the same wire at the same degree of torque. this finding agrees with the findings of many other researchers 20,22,33-35 . the higher frictional resistance of ceramic brackets may be attributed in part to the rough surface texture of these brackets in contrast to the smooth surface of stainless steel brackets. also the increased hardness of the ceramic aluminum oxide material as compared to metal brackets and wires may have contributed to such result. there was only one exception for this comparisom that in case of clear self-ligating brackets there was no significant difference from stainless-steel self-ligating in case of zero torque in both wires, this is related to the fact that there is no actual binding between these brackets and the wires. references 1. dobrin rj, kamel il, musich dr. load deformation characteristics of polycarbonate orthodontic brackets. am j orthod 1975; 67: 24-33. 2. reicheneder ca, baumert u, gedrange t, proff p, faltermeier a, muessig d. frictional properties of aesthetic brackets. eur j orthod 2007; 29(4): 359-65. 3. maria francesca sfondrini, danilo fraticelli federico rosti, andrea scribante, paola gandini. frictional j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry130 properties of self-ligating brackets and low-friction ligatures. current research in dentistry 2012; 3(1): 16. 4. berger j.self-ligation in the year. j clin orthod 2000; 34: 74-81. 5. thorstenson ga, kusy rp. effects of ligation type and method on the resistance to sliding of novel orthodontic brackets with second-order angulation in the dry and wet states. angle orthod 2003; 73: 418430. (ivsl) 6. nanda r. biomechanics in clinical orthodontics. 1st ed. w.b. saunders company; 1997. 7. stolzenberg j. the russell attachment and its improved advantages. int j orthod dentistry children 1935; 21: 837-840. 8. gandini p, orsi l, bertoncini c, massironi s, franchi l. in vitro frictional forces generated by three different ligation methods. angle orthod 2008; 78(5): 917-921. 9. taylor ng, ison k. ferictional resistance between orthodontic brackets and archwires in the buccal segments. angle orthod 1996; 66(3): 215-222. 10. kahlon s, rinchuse d, robison jm, close jm. invitro evaluation of frictional resistance with 5 ligation methods and gianelly-type working wires. am j orthod dentofac orthop 2010; 138:67-71. 11. meling tr, qdegaard j, holthe k, segner d. the effect of friction on the bending stiffness of orthodontic beams: a theoretical and in vitro study. am j orthod dentofac orthop 1997; 112(1): 41-9. 12. hain m, dhopatkar a, rock p. the effect of ligation method on friction in sliding mechanics. am j orthod dentofac orthop 2003; 123(4):416-422. 13. krishman v, kumar j. mechanical properties and surface characteristics of three arch wire alloys. angle orthod 2004; 74(6):823-829. 14. jassim es. the effect of bracket ligation methods on canine retraction. master thesis, college of dentistry, university of baghdad, 2006. 15. baccetti t, franchi l, camporesi m. forces in the presence of ceramic versus stainless steel brackets with unconventional vs conventional ligatures. angle orthod 2008; 78(1): 120-124. 16. sims ap, waters ne, birnie dj, pethybrige rj. a comparison of the forces required to produce tooth movement in vitro using two self-ligating and a preadjusted bracket employing two types of ligation. eur j orthod 1993; 15(5): 377-85. 17. pizzoni l, ravnholt g, melsen b. frictional forces related to self-ligating brackets. eur j orthod 1998; 20(3): 283-91. 18. cacciafesta v, sfondini mf, ricciardi a, scribante a, klersy c, auricchio f. evaluation of friction of stainless steel and esthetic self-ligating brackets in various bracket-archwire combinations. am j orthod dentofac orthop 2003; 124(4): 395-402 19. mohammed aa. frictional forces generated by three different ligation methods (an in vitro study). a master thesis, college of dentistry, university of baghdad, 2010. 20. bednar jr, gruendeman gw, sandrik jl. a comparative study of frictional forces between orthodontic brackets and archwires. am j orthod dentofac ortho 1991; 100(6): 513-22. 21. redlich m, mayer y, harari d, lewinstein i. in vitro study of frictional force during sliding mechanics of ‘‘reduced-friction’’ brackets. am j orthod dentofac orthop 2003;124:69–73 22. articolo lc, kusy rp. influence of angulation on the resistance to sliding in fixed appliances. am j orthod dentofac orthop 1999; 115(1): 39-51. 23. kusy rp, whitley jq. influence of archwire and bracket dimensions on sliding mechanics: derivations and determinations of the critical contact angles for binding. eur j orthod 1999; 21: 199-208. 24. zufall sw, kusy rp. sliding mechanics of coated composite wires and the development of an engineering model for binding. angle orthod 2000; 70(1): 34–47. (ivsl) 25. proffit wr, fields hw, ackerman jl, baily l, tulloch jfc: 1st stage of comprehensive treatment: alignment and leveling. in: contemporary orthodontics. 3rd ed. mosby; 2000: pp.526-551. 26. moore mm, harrington e, rock wp. factors affecting friction in the pre-adjusted appliance. eur j orthod 2004; 26: 579–583. 27. hamdan a, rock p. the effect of different combinations of tip and torque on archwire/bracket friction. school of dentistry, university of birmingham, uk. eur j orthod 2008; 30: 508–514. 28. sims apt, waters ne, birnie dj. a comparison of the forces required to produce tooth movement ex vivo through three types of pre-adjusted brackets when subjected to determined tip or torque values. br j orthod 1994; 21: 367–373. 29. chunga m, nikolai rj, kim kb, oliver dr. thirdorder torque and self-ligating orthodontic bracket–type effects on sliding friction. angle orthod 2009; 79: 551-557. 30. drescher d, bourauel c, thier m. application of the orthodontic measurement and simulation system (omss) in orthodontics. eur j orthod 1991; 13: 169 – 178. 31. ogata rh, nanda rs, duncanson mg, sinha pk, currier gf. friction resistances in stainless steel bracket-wire combinations with effect of vertical deflections. am j orthd dentofac orthop. 1996; 109(5): 535-542. 32. henao sp, kusy rp. evaluation of the frictional resistance of conventional and self-ligating bracket designs using standardized archwire and dental typodonts. angle orthod 2004; 74(2): 202-211. 33. omana hm, moore rn, bagby md. frictional properties of metal and ceramic brackets. j clin orthod 1992; 26(7): 425-432. 34. al-nasseri nah. frictional resistance between orthodontic brackets, and archwires. a simulation of maxillary canine retraction along a continuous archwire. a master thesis, college of dentistry, university of baghdad, 2000. 35. al-mukhtar amy. evaluation of friction generated during sliding of orthodontic bracket on orthodontic arch wire using different bracket, arch wire and ligature materials. a master thesis, orthodontic department, college of dentistry, university of mosul, 2005. j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of pedodontics, orthodontics and preventive dentistry131 figure 5: static frictional force of different brackets and wires figure 1: the alignment of the brackets at zero degree torque figure 2: the fixation of the tubes by composite figure 3: measuring twenty degree figure 4: the alignment of the brackets at twenty degree torque hussein.doc j bagh college dentistry vol. 27(2), june 2015 a study to compare restorative dentistry 11 a study to compare the cleaning efficiency of different irrigation systems for macro debris removal in instrumented canals (an in vitro study) hussein a. hussein, b.d.s. (1) mohammed r. hameed, b.d.s., m.sc., ph.d. (2) abstract background: irrigation of the canal system permits removal of residual tissue in the canal anatomy that cannot be reached by instrumentation of the main canals so the aim of this study was to compare and evaluate the efficiency of conventional irrigation system, endoactivator sonic irrigation system,p5 newtron satelec passive ultrasonic irrigation and endovac irrigation system in removing of dentin debris at three levels of root canals and to compare the percentage of dentin debris among the three levels for each irrigation system. materials and methods: forty extracted premolars with approximately straight single root canals were randomly distributed into 4 tested groups of 10 teeth each. all canals were prepared with protaper universal hand files to size #f4, and irrigated with 2.5% naoci 1 ml between files and 5ml for 60 seconds as a final irrigant by different irrigation devices; group one, by using conventional system; group two, by using endoactivator sonic irrigation system, group three, by using satelec passive ultrasonic irrigation and group four by using the endovac system. after the final irrigation, the roots were split longitudinally and photographed with a digital microscope. the roots were magnified to 100x; a percentage of debris was calculated for the apical 0-3, middle 3-6 and coronal 6-9 mm. the debris score was calculated as a percentage of the total area of the canal that contained debris as determined by pixels in adobe photoshopcs5. data were analyzed statistically by anova and lsd at 5% significant level. results: when comparing the debris remaining, the endovac, endoactivator and satelec groups showed significantly less debris than the conventional group at all three levels (p < 0.01). the endovac group showed significantly less debris than the endoactivator group at middle and coronal levels while no significant difference found between the endovac system and endoactivator system at apical level. the apical 0-3 mm showed significantly more debris than both the middle and coronal level for all groups. conclusion: the endovac system showed a higher cleaning capacity of the canal at all levels, followed by the protocols that used endoactivator sonic irrigation system. the conventional irrigation system with maxi-i-probe needles showed inferior results. the apical three millimeters showed a greater amount of debris than the 3-9 millimetres from the working length, regardless of the irrigation device used. key words: dentin debris, endoactivator, p5 newtron satelec, endovac. (j bagh coll dentistry 2015; 27(2):11-16). introduction removal of the remains of vital and necrotic pulp tissue, microorganisms and microbial toxins from the root canal system is essential for successful endodontic treatment. irrigating solutions act mainly as lubricant and cleaning agent during biomechanical treatment, removing microoganisms, products associated to tissue degeneration and organic and inorganic remains, guaranteeing elimination of contaminated dentin and permeability of the canal throughout its length (1,2). effective action is achieved by ensuring that irrigants come into direct contact with all canal walls, particularly in the more apical portion (3). at present, no single irrigant combines all the ideal characteristics, even when they are used with a lower ph, increased temperature or added surfactants to increase their wetting efficacy. no single irrigant has demonstrated an ability to dissolve organic pulp material and demineralize the calcified organic portion of canal walls (4). (1)master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. throughout the history of endodontics, ongoing efforts have been made to develop more effective systems to send and agitate irrigant solutions in the canal system. these systems can be divided into two broad categories of manual and mechanical agitation techniques. machineassisted procedures include using rotary brushes, simultaneous irrigation with rotary instrumentation of the canal, pressure alternation devices and sonic and ultrasonic systems. all of them appear to improve canal cleaning in comparison to conventional syringe and needle irrigation (5,6). the purposes of this study are to compare and evaluate the efficiency of maxii-probe (conventional irrigation system), endoactivator (sonic irrigation system), satelec p5 newyron (passive ultrasonic irrigation system and endo vac (apical negative pressure irrigation system) in removing of dentin debris at three levels of root canal and to compare the percentage of dentin debris among the three levels for each irrigation system. j bagh college dentistry vol. 27(2), june 2015 a study to compare restorative dentistry 12 materials and methods a total of 40 extracted permanent single canal premolars teeth were used. immediately after extraction, the teeth cleaned with cumine scaler to remove calculus and soft tissue debris then washed under tap water and kept in distilled water (7). access preparations were made and patency established by passing a #10 k-file beyond the apex of all canals. working lengths were determined by subtracting 0.5 mm from the length at which the # 10 file first appeared at the apical foramen. the teeth were mounted in the surgical tube filled with silicon material within l mm apical to cemento-enamel junction (8). the teeth prepared with protaper hand system (dentsply, maillefer, switzerland), the method of use was based on the balanced force technique. shaping files sx were used to enlarge the coronal two third of the canal then the shaping continue with s 1 and s2 files to the wl. the apical third prepared with finishing files f1 followed by f2, f3, and f4 in sequence to the full wl (9). the teeth were divided into three groups 10 teeth for each. group 1 served as conventional (control) group, a 30-gauge max-i-probe needle (maxp30i, dentsply, rinn, usa.) attached to 5 mlluer lock syringe was used to deliver 1ml of 2.5% sodium hypochlorite to the canals between each files and 1 ml before sx protaper file. during irrigation, the needle was placed short of the binding point in the canal and no closer than 2 mm to the wl. the final irrigation with 5 ml of 2.5 % sodium hypochlorite was applied inside the canal 2 mm shorter from working length in up and down movement of the needle for 60 seconds (6). group 2 received sonic irrigation by endoactivator system (figure 1). the activating of the irrigation solution was following the manufacturer's recommendations for using this device after completion of cleaning, shaping and irrigation of the canal with a manual syringe and an endodontic irrigation needle. irrigant into the canal and chamber, passively fitting tip #25 was activated at 10,000 cycles/min for 30-60 seconds and 2 mm shorter than the working length then the canal was dried after delivering the final irrigation solution (10). figure 1: endoactivator system group 3 received apical negative pressure irrigation by the endo vac system (figure 2). its technique was according to the manufacturer's instructions. irrigation was started by using the mdt at the access and dispensing 1 ml of naoci each time after using protaper hand instrumentation to size f4. the macrocannula was then used and placed inside the canal to about 3-4 mm from wl to dispense the same amount (1 ml) of naocl after each endodontic file. at the same time, the master delivery tip was placed at the access to continue irrigating at the access. again, 1 ml of naocl was delivered after each endodontic file. each canal should be cleaned and irrigated simultaneously for 30 seconds. then the master delivery tip was removed quickly approximately 1 second after removing the macrocannula to leave the canals charged with fresh irrigant. lastly, the mdt was returned to continue irrigating at the access while placing the microcannula inside the canal at 2 mm from the wl for 6 seconds. the microcannula was then moved down to wl and held in position for 6 seconds. this process was repeated for a total of 3 cycles per canal with delivering 1 ml of naocl each time. figure 2: endovac system group 4 received a passive ultrasonic activation for the irritant figure 3. the instrumented teeth on placing were subjected to an ultrasonic activation on power 5 passively movement inside the root canal. the file used was #15 tip size in 1 mm shorter than the working length the irrigation solution was delivered intermittently every 20 seconds for 1 minute for better removal of debris than continuous irrigation (11). figure 3: p5 newtron satelec ultrasonic irrigation system j bagh college dentistry vol. 27(2), june 2015 a study to compare restorative dentistry 13 the canals were dried by protaper paper point and the access cavities were closed by cotton pellet and temporary filling (12). guiding lines were made horizontally and longitudinally by blue marker before sectioning. the horizontal groove was made at cementoenamal junction and the roots were longitudinally grooved with a diamond disk. the crowns and roots were split by chisel in the groove and striking the chisel with a small mallet. the bucco-lingual longitudinal section of each root with < 180° of the canal circumference was selected for study. the sections with > 180° of canal circumference would possibly interfere with total canal visualization during photography (13). the magnification should be a 100 x magnification for debris analysis so a digital microcroscope was used figure 4 (, for transferring images to the pc and processed via adobe photoshop cs2 software (adobe systems inc., san jose, ca) and enlarged to 100 x the original size. lines were superimposed over the canals at 0, 3,6, 9 mm from the apical constriction. each canal was traced and the total number of pixels occupied by the debris was reported by using the histogram function in the software program. the outline of the canal up to 9mm then traced and the same feature of the software reported the total pixels occupied by the canal. percentage of debris was calculated by the pixels of debris at each level pixels representing the entire area of the canal. percentage of debris was calculated for 3 levels (11,13). the data were collected and analyzed using spss (version 16) for statistical analysis. one way analysis of variance (anova) and least significant difference test (lsd) was used to determine whether there is a statistical difference among the groups and within group at different levels with a significance level of p<0.05. results the mean percentage of debris remaining in experimental groups is shown in table 1 and figure 5. the comparison between the four irrigation systems in removing of dentin debris at each level to compare among the four irrigation systems at each region, anova test was performed to analyze the presence of statistically difference for the percentage of remaining debris and the result showed that there were high significant differences at all regions. least significant difference (lsd) test was performed and the result showed that at the apical region high significant differences (p<0.0l) were found between maxi-i­ probe, passive ulatrasonic irrigation, endoactivator and endovac. while no significant difference was found between endoactivator, ultrasonic irrigation and endovac, while at the middle region high significant differences (p<0. 01) were found between. maxii-probe and both other groups, endoactivator and pui, pui and endovac while no significant diffrerence between endovac and endoactivator. at the coronal region high significant differences (p<0.0l) were found between the groups except for passive ultrasonic irrigation and endoactivator where no statistical significant difference were found. (p>0.05) the percentage of dentin debris at three difference levels for each irrigation system the percentages of dentin debris remaining at the middle and coronal levels were significantly less than found at apical groups, while the middle level showed no significant difference with coronal percentage of dentin debris for all groups. table 1: descriptive statistical analysis for the percentage of debris remaining at three levels for three irrigation systems region group n min % max. % mean % +sd apical max-i-probe 10 2.024 4.425 2.950 0.630 endoactivator 10 0.701 1.156 0.891 0 .143 pui 10 0.636 1.688 0.977 0.136 endovac 10 0.507 0.856 0.657 0.094 middle max-i-probe 10 0.751 1.838 1.365 0.377 endoactivator 10 0.364 0.622 0.501 0.077 pui 10 0.473 1.063 0.707 0.073 endovac 10 0.268 0.508 0.330 0.077 coronal max-i-probe 10 0.845 1.459 1.045 0.213 endoactivator 10 0.416 0.681 0.557 0.096 pui 10 0.416 0.915 0.551 0.091 endovac 10 0.197 0.417 0.320 0.079 j bagh college dentistry vol. 27(2), june 2015 a study to compare restorative dentistry 14 figure 5: bar chart showing means percentage of dentin debris remaining three difference levels for each irrigation system. discussion the main aim of root canal treatment is to eliminate microorganisms and their irritants from root canals before filling (14). but it has been proven that 40-50% of the root canal walls is untouched by the mechanical instrumentation (15). the technical problem associated with endodontic irrigation; getting sufficient volume of solution to the working area of the instrument, particularly in fine or tortuous root canals. so other systems for irrigation activation were used to increase the efficiency of cleanliness. in this study, four irrigation systems were used to compare between their efficacy for cleaning the root canals and at different levels. the first group was depending on side vented max-i-probe irrigation needle, used because of its ease of use and popularity in iraqi clinics, the second group depending on sonic vibration concept, the third one depending on a passive ultrasonic mean, which is also widely available in iraqi specialized dental centres, and the apical negative pressure device. the efficiency of the three irrigation systems at apical level: at the apical level, the endoactivator, endovac and satelec pui resulted in less debris removal than needle irrigation. the least debris remained were seen in endovac group followed by endoactivator and pui respectively with no significant difference. due to the apical suction effect of pulling (not pushing) endodontic irrigants down and along the walls of the root canal system that created a rapid turbulent cascading effect as close as 0.2mm microcannula of the endovac (16,17). the endoactivator works under the principle of sonic vibration to activate the irrigant and the satelec with the ultrasonic waves following the rule stated by van et al (18). the efficiency of the three irrigation systems at middle and coronal levels at the middle and coronal levels the endovac group registered the lowest mean debris remainants while no significant difference was seen between the endovac and endoactivator at the middle level and between pui and endoactivator but at the coronal level, the rest were high (p<0.05) significant, this was because the endovac macrocannula design and mode of irrigation permitting lower debris in those thirds i.e. the tip design of the cannula giving a more approximate contact with the walls giving a higher shear stresses on the canal walls resulting in cleaner canals which coincides with boutsioukis et al (19). the macrocannula also act as a manual­ dynamic irrigant system and negative pressure system at the same time; the open end acted to sucking of irrigation solution with debris. the push-pull motion of a plastic macro cannula in the canal might generate higher intracanal pressure changes during pushing movements resulting in greater debris removal which agreed with mcgill et al. (20). palazzi et al. in 2012 showed that negative pressure irrigation may improve irrigants volumes, intimacy and time of contact with root canal walls, especially into un instrumented areas of the rcs, enhancing surface debridement (21). the results also coincides with kanter and weldon in 2009 (22) who found that the sonic irrigation was statistically significantly better than the control group in removing loose debris 3mm from the radiographic apex while there is no j bagh college dentistry vol. 27(2), june 2015 a study to compare restorative dentistry 15 agreement or definitive evidence to support one form of energy is superior to the other, this observation is supported by the mathematical formula that prognosticates streaming velocity. v = 2fa2/r where f'= frequency, a = amplitude, and r = the radius of the instrument. ultrasonic energy generates higher frequencies than those generated by sonic driven devices. the frequency may be thought of as the interval of time it takes a vibrating tip to move through one back and forth displacement cycle. further, it is also well known that sonic energy generates significantly higher amplitudes or greater back and forth tip movement, compared to ultrasonically driven instruments. regardless of the energy source, a sinusoidal type wave of energy, with a given periodicity, is produced that travels over the length of an instrument. this oscillating wave of energy produces amplitude of modulation. on the contrary, sonic energy produces lower frequencies compared to ultrasonic devices. however, van der sluis (11) has shown that when a sonically driven instrument was loaded, the elliptical motion was eliminated, leaving a pure longitudinal file oscillation. this mode of vibration has been shown to be particularly efficient, as it was largely unaffected by loading and displayed large displacement amplitudes. even though the streaming velocity formula may not perfectly account for intracanal conditions, larger amplitudes exponentially influence the hydrodynamic phenomenon. mozo et al. concluded that pui is more effective than conventional syringe and needle irrigation in eliminating pulp tissue and dentin debris due to the fact that ultrasound creates a higher speed and flow volume of the irrigant in the canal during irrigation, thereby eliminating more debris (23). also the result of this study showed that a higher mean percentage of debris in the coronal than the middle in the endoactivator. a possible explanation is that may be the oscillation amplitude of the sonically activated irrigation needle is higher than at the attached end where sonic node of vibration exists (24). the amount of dentin debris among three levels susin et al. suggested that the difficulty in getting irrigating solutions to reach the isthmus and to create a strong enough current to flow through the isthmus between canals could explain why anp irrigation did not completely remove debris from the isthmus regions in a closed canal system. the amount of debris removal was lower in the apical than other levels for all groups because the apical instrumented space was narrowest than the middle and coronal region so less amount of irrigation delivered to these area and also the complexity and irregularity of these area rendering more debris apically (25). the use of finer needles (30g) may facilitate direct access to the apical region. although conclusive evidence is lacking, the introduction of fine irrigation needles with a safety tip placed at the working length or 1 mm shorter can improve irrigant effectiveness, though still more apical part had more remnants than upper levels (26). references 1. candeiro gt, matos lb, costa cf, fonteles cs, vale ms. a comparative scanning electron microscopy evaluation of smear layer removal with apple vinegar and sodium hypochlorite associated with edt a. j appl oral sci 2011; 19(6): 639-43. 2. costa e, evangelista a, medeiros a, dametto f, carvalho r. in vitro evaluation of the root canal cleaning ability of plant extracts and their antimicrobial action. braz oral res 2012; 26(3): 21521. 3. dadresanfar b, khalilak z, delvarani a, mehrvarzfar p, vatanpour m, pourassadollah m. effect of ultrasonication with edta or mtad on smear layer, debris and erosion scores. j oral sci 2011; 53(1): 31-6. 4. mittal r, singla m, garg a, gupta s, dahiya v. comparative evaluation of the antimicrobial efficacy of mtad, oxytetracycline, sodium hypochlorite and chlorhexidine against enterococcus faecalis: an exvivo study. ir dent j 2012; 2(2): 70-4. 5. kocani f, kamberi b, dragusha e, mrasori s, haliti f. the cleaning efficiency of the root canal after different instrumentation technique and irrigation protocol: a sem analysis. j endod 2012; 2(2): 69-76. 6. snjaric d, carija z, braut a, halaji a, kovacevic m, kuis d. irrigation of human prepared root canal ex vivo based computational fluid dynamics analysis. croat med j 2012; 53(5): 470-9. 7. tasdemir er, yildirim c. effect of passive ultrasonic irrigation. eur j dentistry 2008; 2:198-203. 8. shen y, bian z, cheung gs, peng b. analysis of defects in pro taper hand-operated instruments after clinical use. j endod 2007; 33: 287-290. 9. perez-heredia m, ferrer-luque enl gonzalez­ rodriguez mp. the effectiveness of different acid irrigating solutions in root canal cleaning after hand and rotary instrumentation. j endod 2006: 32: 993 997. 10. haapasalo m, shen y, qian w, gao y. irrigationin endodontics. dent clin n am 2010: 54: 291-312. 11. van der sluis lw, versluis m, wu nik, wesselink pr. passive ultrasonic irrigation of the root canal: a review of the literature. int endod j 2007; 40: 415-26. 12. torres u, paloma m, maria c. effectiveness of the endoactivator system in removing the smear layer after root canal instrumentation. j endod 2009; 35: 699-702. 13. munley pi, goodell gg. comparison of passive j bagh college dentistry vol. 27(2), june 2015 a study to compare restorative dentistry 16 ultrasonic debridement between fluted and nonfluted instruments in root canals. j endod 2007; 33: 578-80. 14. jaju s. newer root canal irrigants in horizon: a review. int j dent 2011; 2: 312-24. 15. pitt wg. removal of oral biofilm by sonic phenomena. am j dent 2005; 18(5): 345-52. 16. siu c, baumgartner je. comparison of the debridement efficacy of the endovac irrigation system and conventional needle root canal irrigation in vivo. j endod 2010; 36: 1782-5. 17. nielsen b, baumgartner j. comparison of the endovac system to needle irrigation of root canals. j endod 2007; 33(10): 46-9. 18. van der sluis lw, gambarini g, wu mk, wesselink pr. the influence of volume, type of irrigant and flushing method on removing artificially placed dentine debris from the apical root canal during passive ultrasonic irrigation. int endod j 2006; 39:472-6. 19. boutsioukis c, verhaagen b, versluis m, kastrinakis e, wes-selink pr, van der sluis lw. evaluation ofirrigant flow in the root canal using different needle types by an unsteady computa-tional fluid dynamics model. j endod 2010; 36(5): 875-9. 20. mcgill s, gulabivala k, mordan n, ng yl the efficacy of dynamic irrigation using a commercially available system (rinsendo) determined by removal of a collagen 'biomolecular film' from an ex vivo model. intern endod j 2008; 41, 602-8. 21. palazzi f, morra m, mohammadi z, grandini s, giardino l. comparison of the surface tension of 5.25% sodium hypochlorite solution with three new sodium hypochlorite-based endodontic irrigants. intern endod j 2012; 45:129-35. 22. kanter v, weldon e, nair u, varella c, kanter k, anusavice k, pileggi r. a quantitative and qualitative analysis of ultrasonic versus sonic endodontic systems on canal cleanliness and obturation. oral surg oral med oral pathol oral radiol endod 2011; 112(6): 809-13. 23. mozos s, llena c, forner l. review of ultrasonic irrigation in endodontics: increasing action of irrigating solutions med oral patol oral cir bucal 2012; 17(3): e512-6. 24. jiang lm, verhaagen b, versluis m, van der sluis lw. evaluation of a sonic device designed to activate irrigant in the root canal. j endod 2010; 36: 143-6. 25. rodig t, bozkurt m, konietschke f, hiilsmann m. comparison of the vibringe system with syringe and passive ultrasonic irrigation in removing debris from simulated root canal irregularities. j endod 2010; 36: 143-6. 26. tasdemir er, yildirim c. effect of passive ultrasonic irrigation. eur j dentistry 2008; 2: 198-203. :الخالصة بازالة الحطام والشوائب في ثالث مناطق في القنوات الجذریة المجھزة باستعمال ٠اجریت ھذه الدراسة في المختبر لتقییم ومقارنة كفاءة اربعھ من انظمة الغسیل واستعمال الترددات الفوق صوتیة بواسطة جھاز endoactivatorوالغسل بمساعدة الترددات الصوتیة باستعمال جھاز max-probeالطریقة االعتیادیة بواسطة satelec pui والغسل باستخدام الضغط السلبي للغسل القمي بجھازendovac م تم تقسی , ومقارنة النسبة المئویة لكل منطقة ومقارنة النسب بین الطرق االربعة عھ تم اعداد جمیع االسنان الضواحك االربعین المقلوعھ ذوات القنوات االحادیة المستقیمة الجذر الى مجموعات االختبار االربع بواقع عشرة اسنان لكل مجمو ثانیة بمادة صودیوم 60سل النھائي لمدة تم الغ, مل بین المبارد التي كانت نصف ملم من القمة التشریحیة 1 العینات بواسطة نظام البروتیبر لحجم وغسل القنوات ب endoactivatorوالمجموعة الثانیة باستخدام الترددات الصوتیة ) max -i-prob(مل باستخدام النظام التفلیدي 5بكمیة وقدرھا %) 2.5(ھایدروكلورایت والمجموعة االخیرة باستخدام الضفط السلبي للغسل القمي satelec puiوالمجموعة الثالثة باستخدام الترددات الفوق صوتیة بواسطة جھاز . endovacبجھاز تم حساب النسبة المئویة . مرة 100بعد الغسل النھائي تم تقسیم الجذور طولیا ولكشف وحساب الحطام في كل مستوى صورت العینات بواسطة مجھر رقمي بتكبیر وب فوتوشوب االصدار الخامس دل مستوى في المجموعھ مع مساحة القناة كاملة في الحاسوب باستخدام برنامج االحطام في ك من الحطام بتقسیم مساحة البكسل من . %5توى سم و عند lsd testو anova testالبیانات احصائیا بواسطة تحلیلوقد ئم لم ینتج , على جمیع المستویات max-probeورنت بنظام الغسل التقلیدي ان اجھزة الغسل الجدیدة في القنوات تنظف كثیرا اذا ما ق:تم االستنتاج من ھذه الدراسة اظھرت افضل النتائج و عند endovacفي المنطقة القمیة و القنوات التي استخدمت معھا جھازendoactivator و satelec pui فرق كبیر بین مجموعتیي عن الطریقة المستخدمة للغسلالمنطقة القمیة تبین وجود اكبر كمیة من الحطام بغض النظر ban f.doc j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 91 periodontal health status and salivary enzymes level in smokers and non-smokers (comparative, cross sectional study) ban karem, b.d.s. (1) leka'a m. ibrahim, b.d.s, m.sc. (2) abstract background: smoking is considering a major risk factor for development and progression of periodontal disease. investigations regarding the association between smoking and periodontal disease have consistently demonstrated negative periodontal effects and greater probabilities of established periodontal disease among smokers in comparison with non smokers. the purpose of this study was to evaluate the effects of smoking on periodontal health status and on the salivary levels of alkaline phosphatase (alp), lactate dehydrogenase (ldh) and creatine kinase (ck), and to correlate the clinical parameters of periodontal health with the biochemical findings in smokers and non-smokers. materials and methods: unstimulated saliva sample was collected from 25 smokers and 25 non-smokers for biochemical analysis of salivary enzymes. periodontal parameters including: plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level were recorded. results: statistical analysis revealed that alp in saliva was significantly higher in smoker than the non smoker group and there was a highly significant difference in the salivary ldh and ck levels between smokers and non-smokers groups. plaque index (pli), probing pocket depth (ppd) and clinical attachment level (cal) were higher in smokers compared with non smokers, while there was decrease in the number of bleeding sites. conclusions: smokers group revealed more periodontal tissue destruction than non-smokers group represented by deeper pockets and more clinical attachment level. salivary enzymes (alp, ldh and ck) are considered as good biochemical markers of periodontal tissue destruction and can be used to evaluate the effect of smoking on periodontal health status. keywords: non-smokers, smokers, salivary enzymes, periodontal health status. (j bagh coll dentistry 2013; 25(3):9196). introduction periodontal disease is defined as inflammatory destruction of periodontal tissue and alveolar bone supporting the teeth. severe and prolonged periodontal inflammation leads to loss of teeth, thereby affecting oral functions (e.g., mastication, speech and facial esthetics). progression and severity of the disease depends on complex interactions between several risk factors such as microbial, immunological, environmental and genetic factors as well as age, sex and race (1). tobacco smoking, mostly in the form of cigarette smoking, is recognized as the most important environmental risk factor in periodontitis (2). the role of smoking in periodontal diseases has been extensively studied for many years. clinical and epidemiological studies build up an increasing amount of scientific data which support the concept that tobacco use has a clear association with the prevalence and progression of periodontal disease (3). studies have indicated that the risk of having periodontitis among smokers varied from two to six times compared with non-smokers (4, 5). saliva has been used in the past few decades as a new diagnostic fluid (6-8). (1) m.sc. student, department of periodontics, college of dentistry, baghdad university. (2) professor, department of periodontics, college of dentistry, baghdad university. saliva has been extensively studied in relation to periodontal disease because it is easily collected and allows analysis of several local and/or systemic biological markers. proposed salivary diagnostic markers for periodontal diseases have included serum and salivary molecules such as immunoglobulins, enzymes constituents of gingival crevicular fluid, bacterial components or products, volatile compounds and phenotypic markers, such as epithelial keratins (6). enzymes are biological catalysts that carry out tightly controlled biological reactions with high specificity. like a chemical catalyst, an enzyme acts by lowering the activation energy of a reaction, thereby inducing the formation of the products from the substrates (9). intracellular enzymes are increasingly released from the damaged cells of periodontal tissues into the gingival crevicular fluid (gcf) and saliva. several enzymes are evaluated for the early diagnosis of periodontal disease such as alkaline phosphatase (alp), lactate dehydrogenase (ldh) and creatine kinase (ck) (6, 10, 11). materials and methods human sample fifty subjects were enrolled in the study, the subjects with an age range (30-45) year's old males and females. subjects included in the study were drawn randomly regardless the periodontal j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 92 health status from patients attending the department of diagnosis in the college of dentistry, university of baghdad and department of diagnosis in al-karama specialized center. each participant received complete medical and dental history to determine their suitability to the study and all of them had no history of systemic disease. all subjects were presenting at least 20 teeth. the exclusion criteria were including: a course of anti-inflammatory or antimicrobial therapy within the previous three months, a history of regular use of mouth washes, use of any vitamin supplementation, mucosal lesions, chemotherapy, radiation therapy, medications that cause xerostomia. pregnant and lactating females, female patients during the menstrual cycle or suffering from any hormonal disturbance, post-menopausal females or others on estrogen therapy were excluded from this study. former smokers were also excluded. the subjects were divided into non-smokers group included 25 subjects who are not smoking and never smoked before and smokers group included 25 subjects regularly smoked at least 15 cigarettes on average per day for at least 5 years; current smoker and had not quit smoking (12). saliva samples collection un-stimulated whole saliva was collected before the clinical examination. a sample was collected after an individual was asked to rinse his/her mouth thoroughly with water to insure the removal of any possible debris or contaminating materials and waiting for 1-2 min for water clearance. the samples were collected at least 1 h after the last meal. each one of the groups’ subjects was asked to spit saliva into the polyethylene tubes until 5 ml was collected. the collected saliva was centrifuged and then the centrifuged clear supernatant saliva was collected by micropipette into eppendrof tubes and kept frozen and store at -20oc until biochemical analysis of salivary enzymes. clinical examination clinical periodontal parameters included assessment of plaque index (pli) (13), gingival index (gi) (14), bleeding on probing (bop) (15), probing pocket depth ppd and clinical attachment level cal. collected data were recorded by using william’s periodontal probe on four sites around each tooth (mesial, buccal, distal and lingual) excluding third molars. the probe was directed parallel to the long axis of the tooth. the ppd measurement has been performed using a scale for ease of comparison between groups; it contains scores from (0-3) as shown in table 1. table 1: scale of ppd measurements scale score 0 score 1 score 2 score 3 ppd in (mm) 0-3 >3-5 >5-7 >7 clinical attachment level was obtained by measuring the distance from the cemento-enamel junction to the bottom of the pocket at each site. the cal measurement performed using a scale that contains scores from (1-4) as shown in table 2. table 2: scale of cal measurements scale score 1 score 2 score 3 score 4 cal in (mm) 1-3 >3-5 >5-7 >7 biochemical analysis for enzymes analysis we use kits manufactured by biolabo sa (alp, ck), also we used kit manufactured by human; german company, for ldh enzyme. the activity of alp was determined by measuring its absorbance at 510 nm by the spectrophotometer, while the activities of ldh and ck were determined by measuring the absorbance at 340 nm by the spectrophotometer. statistical analysis descriptive statistics in the form of mean, standard deviation and percentage and inferential statistics in the form of student t-test, p-value and pearson correlation were used in this study. the level of significance was accepted at p< 0.05, and highly significance when p< 0.01. results a-clinical periodontal parameters the result of the study revealed that pli in smokers was higher that non smokes and the difference was statistically significant, while non significant difference was found in gi between smokers and non smokers as shown in table 3. the bop results showed that smokers have less number of sites with bleeding on probing than non smoker group, chi-square test was applied to bop and revealed highly significant difference between the two groups (p<0.01) (table 4). there was increase in the total number of ppd scores (1and 2) in smokers compared to nonsmokers except for score 0 which was decreased. chi-square test revealed highly significant difference in ppd between the two groups (table 5). the results of the study revealed increase in cal with its different scores in smokers group (score 1, 2 and 3) when compared with nonj bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 93 smokers group. chi-square test was applied to cal and revealed non significant difference between the two groups (p>0.05) as shown in table 6. b-biochemical analysis the obtained results have shown that the activity of examined enzymes (alp, ldh and ck) in saliva of smokers group was higher than non smokers group as shown in table 7. statistical analysis using the student t-test revealed the presence of significant difference in the activity of alp and a highly significant difference in the activity of ldh and ck between non smokers and smokers groups (p-value < 0.01) as shown in table 8. c-correlation of alp, ldh and ck levels with clinical periodontal parameters this study revealed non significant correlation between the activities of these enzymes with the clinical periodontal parameters (pli, gi, bop, ppd and cal), except between ldh and ppd and between ldh and cal. there was positive significant correlation between pd score 1 and salivary ldh level in smoker group (r=0.487, p=0.014). there was positive strong highly significant correlation between cal score 2 and ldh (r=0.589, p=0.002) and positive significant correlation between cal score 3 and ldh (r=0.407, p=0.043) in smoker group. discussion the result of this study revealed more plaque accumulation in smokers than non-smokers, and this was in agreement with other studies (16, 17, 18), while its disagree with giannopoulou et al (19). it's possible that the increased level of plaque accumulation and debris observed in smokers may attributed to personality trait leading to decreased oral hygiene and / or increased rates of plaque formation (20). the results showed that there was slight elevated gingival index in smokers group compared with non-smokers and the difference between them was non significant. this was in agreement with hashim (21), ustün and alptekin (22) and rosa et al (23), and in disagreement with sreedevi et al (18) and mohammad (24). this could be due to sample selection in which both groups selected randomly regardless periodontal health status. the result of this study revealed that the smokers have less number of sites with bleeding on probing than non smoker group and this was in agreement with sreedevi et al (18), hashim (21) and thomas (25), while disagreement was recorded with linden and mullally (26). this result may be explained by the fact that one of numerous tobacco smokes by-products, nicotine, exerts local vasoconstriction, reducing blood flow, edema and acts to inhibit what are normally early signs of periodontal problems by decreasing gingival inflammation, redness and bleeding (27). studies have suggested that nicotine increases rate of proliferation of gingival epithelium, thus increasing epithelial thickness among smokers (28). also tobacco use has been associated with reduced permeability of peripheral blood vessels (29). according to results of this study, there was increased ppd with its different scores in smokers group compared with non-smokers group (scores 1 and 2) except for score 0 which represent normal gingival sulcus and it was higher in nonsmokers group compared with smokers group. this general increase in ppd in smokers group compared with non-smokers group was in agreement with many studies (17, 18, 21, 24), while it was disagree with preber et al (30). pocket depth measurements are found to be greater in smokers due to increased alveolar bone loss (31, 32). alveolar bone is one of the tissues that is most affected by the progression of periodontal disease. the mechanism of alveolar bone damage produced by smoking is related to the components of tobacco and nicotine metabolites which may act directly as local irritants on the gingival and alveolar bone or systemically because these components are absorbed in the lung, which affects the cellular host defense or bone turnover. smoking seems to disturb the balance between proteolytic and anti-proteolytic activities in periodontal tissue. some in vitro studies provided other possible intimate mechanisms by which smoking may affect bone metabolism. rosa et al (23) reported that nicotine increased the secretion of interleukin-6 and tumor necrosis factor alpha in osteoblasts, also nicotine increased the production of tissue-type plasminogen activator, prostaglandin e2 and matrix metalloproteinase, thereby tipping the balance between bone matrix formation and resorption toward the latter process, as reported by katono et al (33). according to the results, there was increased cal with its different scores in smokers group (score 1, 2 and 3) when compared with nonsmokers group. this general increase in cal in smokers group compared with non-smokers group was in agreement with sreedevi et al (18) and mohammad (24). the general explanation for increase cal in smokers when compared with non-smokers can j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 94 be derived from the same explanations of increased ppd in smokers which were mentioned previously as both of them represent the most important features of chronic periodontitis and reflect the progress and severity of periodontal tissue destruction. cigarette smoking is associated with periodontal disease and considered as major risk factor that lead to increased severity of periodontal disease (34, 35) and increased rates of disease progression (4) and this destruction of periodontal tissue in smokers could affect salivary alp, ldh and ck levels. findings of this study revealed that the level of alkaline phosphatase alp in the smoker group was significantly higher than the non smoker group. only one study was found about the effect of smoking on salivary alp by kibayashi et al (36). in this study alkaline phosphatase were significantly lower in current smokers than in non-current smokers. in this study different enzyme analytical and statistical methods was used. alkaline phosphatase is released from polymorphonuclear cells (pmns) during inflammation (37) and from osteoblasts (38) and periodontal ligament fibroblasts (39) during bone formation and periodontal regeneration respectively. during the active stages of periodotitis, there will be destruction of alveolar bone osteoblasts and fibroblasts and their cell membrane will be ruptured releasing their intracellular contents outside. therefore alp will be released into gcf and saliva and the level of alp will increase in saliva (6, 10, 40). further more, among the various periodontopathogenic bacteria prevotella intermedia and porphyromaonas gingivalis are known to have high alp activity (17) and in this study the smoker group was shown to have higher plaque index which mean higher number of bacteria and this also adding to the total alp level. in this study, there was highly significant difference in salivary ldh level between smoker and non smoker groups. this result was in agreement with ria et al (41), leyva et al (42) and mohammad (24), while it disagrees with kibayashi et al (36). the result of this study showed highly significant difference in salivary ck level between smoker and non smoker groups. in past literature, no study could be traced that assessed the effect of smoking on the ck level in saliva. this increase in the ldh and ck levels in smoker group could be resulting from the destructive effect of smoking on periodontal tissue. ldh and ck are intracellular enzymes included in metabolic processes of cells and they are mostly present in cells of soft tissues. these enzymes are indicators of a higher level of cellular damage and their increased activity in saliva is a consequence of their increased release from the damaged cells of soft tissues of periodontium and a reflection of metabolic changes in the inflamed gingiva (6, 10, 40). consequently, ldh and ck concentrations in saliva, as an expression of tissue breakdown, could be a specific indicator for periodontal disease that affects the integrity of the periodontium in smokers. references 1. nunn me. understanding the etiology of periodontitis: an overview of periodontal risk factors. j periodontol 2000 2003; 32: 11-23. 2. palmer rm, wilson rf, hasan as, scott da. mechanism of action of environmental factorstobacco smoking. j clin periodontol 2005; 32(s6): 180-95. 3. johnson nw, bain ca. tobacco and oral disease. eu-working group on tobacco and oral health. br dent j 2000; 189(4): 200-6. 4. bergström j. influence of tobacco smoking on periodontal bone height. long-term observations and a hypothesis. j clin periodontol 2004; 31(4): 260-6. 5. reibel j. tobacco and oral diseases. update on the evidence, with recommendations. j med princ pract 2003; 12(1): 22-32. 6. kaufman e, lamster ib. analysis of saliva for periodontal diagnosisa review. j clin periodontal 2000; 27(7): 453-65. 7. wong dt. salivary diagnostics powered by nanotechnologies, proteomics and genomics. j am dent assoc 2006; 137: 313-21. 8. lee jm, garon e, wong dt. salivary diagnostics. j orthod craniofac res 2009; 12(3): 206-211. 9. markus r, aaron z. a manual for biochemistry protocols. singapore: world scientific publishing co. pte. ltd.; 2007. 10. ozomeric n. advances in periodontal disease markers. j clin chim acta 2004; 343(1-2): 1-16. 11. todorovic t, dozic i, vicente-barrero m, ljuskovic b, pejovic j, marjanovic m, knezevic m. salivary enzymes and periodontal disease. j med oral patol oral cir bucal 2006; 11: 115-9. 12. arinola og, akinosun om, olaniyi ja. passiveand active-cigarette smoking: effects on the levels of antioxidant vitamins, immunoglobulin classes and acute phase reactants. african journal of biotechnology 2011; 10 (32): 6130-2. 13. loe h, silness j. periodontal disease in pregnancy. i. prevalence and severity. j acta odontol scand 1963; 21, 533-551. j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 95 14. silness j, loe h. periodontal disease in pregnancy. ii. correlation between oral hygiene and periodontal condition. j acta odontol scand 1964; 22, 121-135. 15. carranza fa, newman mg. clinical periodontology. 8th ed. st. louis: saunders; 1996. 16. ankola a, nagesh l, tangade p, hegde p. assessment of periodontal status and loss of teeth among smokers and non-smokers in belgaum city. indian j community med 2007; 32: 75–6. 17. sanikop sh, bhattacharjee s, patil s. a comparative analysis of serum alkaline phosphatase in smokers and non-smokers with chronic periodontitis. srm uni j dent sci 2011; 2(4): 290-5. 18. sreedevi m, ramesh a, dwarakanath c. periodontal status in smokers and nonsmokers: a clinical, microbiological, and histopathological study. int j dent 2012; 2012: 571590. 19. giannopoulou c, cappuyns i, mombelli a. effect of smoking on gingival crevicular fluid cytokine profile during experimental gingivitis. j clin periodontal 2003; 30(11): 996-1002. 20. tonetti ms.cigarette smoking and periodontal disease etiology and management of disease. j ann periodontal 1998; 3: 88-101. 21. hashim f. assessment of alveolar bone loss and measurement of periodontal status by clinical and digital radiographic analysis in smokers and nonsmokers (comparative study). a master thesis, department of periodontology, college of dentistry, university of baghdad, 2007. 22. ustün k, alptekin no. the effect of tobacco smoking on gingival crevicular fluid volume. eur j dent 2007; 1(4): 236-9. 23. rosa mr, luca gq, lucas on. cigarette smoking and alveolar bone in young adults: a study using digitized radiographic. j periodontal 2008; 79(2): 232-44. 24. mohammad an. salivary enzymes as markers of chronic periodontitis among smokers and non smokers. j bagh college dentistry 2011; 23(3): 83-7. 25. thomas d, jean –pierre b, robert j. the effect of cigarette smoking on gingival bleeding. j periodontol 2004; 75: 16-22. 26. linden gj, mullary bh. cigarette smoking and periodontal destruction in young adults. j periodontal 1994; 65(7): 718-23. 27. chen x, wolff l, aeppli d, guo z, luan w, baelum v, fejeskov o. cigarette smoking, salivary/gingival crevicular fluid cotinine and periodontal status. a 10year longitudinal study. j clin periodontol 2001; 28(4): 331–9. 28. gultekin se, sengüven b, karaduman b. the effect of smoking on epithelium proliferation in healthy and periodontally diseased marginal epithelium. j periodontol 2008; 79(8): 1444–50. 29. powell jt. vascular damage from smoking: disease mechanisms at the arterial wall. j vascular medicine 1998; 3: 21-8. 30. preber h, kant t, berbström j. cigarette smoking, oral hygiene and periodontal health in swedish army consenpts. j clin periodontal 1980; 7: 106. 31. stoltenberg j, osborn jb, pihlstrom bl, herzberg mc, aeppli dm, wolff lf, et al. association between cigarette smoking, bacterial pathogens and periodontal status. j periodontol 1993; 64: 242–6. 32. bergstrom j. cigarette smoking and periodontal bone loss. j periodontal 1991; 62: 242-6. 33. katono t, kawato t, tanabe n. nicotine treatment induces expression of matrix metalloproteinases in human osteoblastic saos-2 cells. j acta biochim biophys sin (shanghai) 2006; 38(12): 874-82. 34. mullally bh. the influence of tobacco smoking on the onset of periodontitis in young persons. j tob induc dis 2004; 2(2): 53-65. 35. baljoon m. tobacco smoking and vertical periodontal bone loss. swed dent j suppl 2005; 174: 1-62. 36. kibayashi m, tanaka m, nishida n, kuboniwa m, kataoka k, nagata h, nakayama k, morimoto k, shizukuishi s. longitudinal study of the association between smoking as a periodontitis risk and salivary biomarkers related to periodontitis. j periodontol 2007; 78(5): 859-67. 37. yan f, cao c, li x. alkaline phosphatase level in gingival crevical fluid of periodontitis before and after periodontal treatment. j zhonghua kou qiang yi xue za zhi 1995; 30(4): 255-66. 38. gibert p, tramini p, sieso v, piva mt. alkaline phosphatase isozyme activity in serum from patients with chronic periodontitis. j periodontal res 2003; 38(4): 362-5. 39. taylor ak, lueken sa, libanati c, baylink dj. biochemical markers of bone turnover for the clinical assessment of bone metabolism. j rheum dis clin north am 1994; 20: 589-607. 40. numabe y, hisano a, kamoi k, yoshie h, ito k, kurihara h. analysis of saliva for periodontal diagnosis and monitoring. j periodontology 2004; 40: 115-9. 41. rai b, kharb s, anand sc. salivary enzymes and thiocynate: salivary markers of periodontitis among smokers and nonsmokers; a pilot study. j adv in med dent sci 2007; 1(1): 1-4. 42. leyva huerta er, esquivel chirino c, marín gonzález g, neblina noriega m, olivares tapia s. lactate dehydrogenase activity in gingival crevicular fluid and saliva of smoker with chronic periodontitis. j avances en periodoncia 2009; 21(1). table 3: statistical description (mean ± sd) and t-test of pli and gi between smoker and non smoker groups pli t-test p-value sig. gi ttest p-value sig. non smokers 1.062±0.349 −2.615 0.012 s 1.018±0.271 0.919 0.363 ns smokers 1.347±0.417 1.071±0.090 j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 96 table 4: number and percentage (in sites) of bleeding on probing scores and chi-square test for both groups table 5: number and percentage (in sites) of probing pocket depth scores and chi-square test for both groups table 6: number and percentage (in sites) of clinical attachment level and chi-square test for both groups table 7: statistical description (mean level in iu/l ± sd) of alp, ldh and ck in both groups table 8: inter group comparison between non smokers and smokers groups by using t-test for mean alp, ldh and ck score non smokers smokers chi-square df p-value sig. no. % no. % 0 2275 88.31 2347 92.40 24.481 1 0.000 hs 1 301 11.68 193 7.59 score non smokers smokers chi-square df p-value sig. no. % no. % 0 2561 99.417 2445 96.259 60.849 2 0.000 hs 1 15 0.582 92 3.622 2 0 0 3 0.118 3 0 0 0 0 score non smokers smokers chi-square df p-value sig. no. % no. % 1 139 5.395 409 16.102 4.516 2 0.105 ns 2 22 0.854 110 4.330 3 5 0.194 14 0.551 4 0 0 0 0 enzymes non smokers group smokers group alp 29.673 ± 2.188 31.333 ± 3.442 ldh 63.937 ± 19.704 151.712 ± 65.576 ck 24.637 ± 11.615 45.233 ± 19.491 enzymes t-test p-value significant alp 2.035 0.047 s ldh 6.404 0.000 hs ck 4.539 0.000 hs nadia f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 effect of pedodontics, orthodontics and preventive dentistry137 effect of chemotherapy on oral health status and salivary alkaline phosphatase among leukemic patients nadia a. al-rawi, b.d.s., m.sc., ph.d. (1) raya r. al-dafaai, b.d.s., m.sc. (2) mohamad sammi, m.sc., ph.d. (3) abstract background: leukemia is a broad term given to a group of malignant diseases characterized by diffuse replacement of bone marrow with proliferating leukocyte precursors. chemotherapy has been increasingly used to treat malignant conditions. the systemic sequelae as a result of these immunosuppressive techniques induce many oral and dental complications. this study was conducted to evaluate the effect of chemotherapy on oral health status and activity of salivary alkaline phosphates enzyme in patients with acute lymphocytic leukemia. materials and methods: the study groups included 28 patients with acute lymphocytic leukemia; they were under chemotherapy, aged 20-25 year old. the control group includes healthy subjects matching with study group. plaque, gingival, calculus and loss of attachment status were recorded. after oral examination, stimulated saliva samples were collected from the subjects (study & control groups) and performed under standard condition following instruction and chemically analyzed for the detection of salivary alkaline phosphates enzyme. results the study showed higher mean values of plaque index, gingival index, attachment loss and concentration of salivary alkaline phosphates enzyme among leukemic group than control group with statistically high significant differences. conclusions: it was concluded that patients with acute lymphocytic leukemia have poor oral hygiene and need intense oral hygiene program before, during and after chemotherapy. key words: oral health, salivary alkaline phosphates, chemotherapy, acute leukemia. (j bagh coll dentistry 2013; 25(special issue 1):137-139). introduction acute lymphoblastic leukemia (all) is a fastgrowing cancer of the white blood cells where the bone marrow makes lots of unformed cells called blasts that normally would develop into lymphocytes. however, the blasts are abnormal. they do not develop and cannot fight infections. (1).initial signs and symptoms of leukemia can appear in the mouth or neck. these oral presentations may lead the patient to seek dental care, or they may be noticed during a routine dental examination. oral lesions are more commonly found in patients with acute leukemia; mucosal pallor, mucosal purpura, lymphadenopathy, gingival bleeding, and petechiae are typical manifestations. gingival swelling is frequently found in patients with acute myelogenous leukemia (aml) but is uncommon in patients with acute lymphocytic leukemia (2). immunosuppressive chemotherapy has been increasingly used to treat and, in some cases, cure numerous malignant conditions. the systemic sequelae as a result of these immunosuppressive techniques induce many oral and dental complications. the direct and indirect stomatotoxic effects are associated with the development of ulcerative, hemorrhagic, or infectious complications (3). (1)lecturer. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad. (2)assistant professor. department of basic sciences. college of dentistry. university of baghdad. intracellular enzymes are increasingly released from the damaged cells of periodontal tissues into the gingival crevicular fluid and saliva. several enzymes that are evaluated for the early diagnosis of periodontal disease are aspartate and alanine aminotransferase, lactate dehydrogenase, creatine kinase, alkaline and acid phosphatase (4). the enzyme alkaline phosphatase (alp) plays a role in bone metabolism. it is a membranebound glycoprotein produced by many cells, such as polymorph nuclear leukocytes, osteoblasts, macrophages, and fibroblasts within the area of the periodontium and gingival crevice (5). untreated chronic periodontitis patients exhibit higher level of alkaline phosphatase in whole saliva than did healthy control. a positive correlation was found for alkaline phosphatase in periodontitis patients with pocket depth. alkaline phosphatase is released by secondary granules of neutrophils and its concentration increases significantly with plaque accumulation and increasing inflammation. so this enzyme should be considered to be the best indicator for periodontal disease (5). aims of the study were to evaluate the effects of chemotherapy on the oral hygiene, periodontal health and the activity of salivary alkaline phosphates enzyme in patients with acute lymphocytic leukemia (all) who received chemotherapy, in comparison with control group matching with the study group, and to evaluate the effect of duration of treatment on j bagh college dentistry vol. 25(special issue 1), june 2013 effect of pedodontics, orthodontics and preventive dentistry138 the attachment loss and the concentration of alp enzyme. subjects and method the study groups included 28 patients (19 female, 9 male) with acute lymphocytic leukemia, they were under chemotherapy, (clinically examined at the centre of hematology and scientific research of al – yarmook hospital) aged 20-25 year old. the patients were selected according to the type of the disease (acute lymphocytic leukemia) and according to the duration of the treatment (from 6 -12 months). they were hospitalized after chemotherapy administration. the control group includes 28 healthy subjects matching the study group by age and gender which were randomly selected from the visitors, accompaniers of leukemia patients in the hospital. plaque status was evaluated according to the silness and loe index (6), gingival condition according to loe and silness (7), while dental calculus and the loss of attachment were assessed according to periodontal disease index (pdi) by ramfjord(8). after oral examination, stimulated saliva samples were collected from the subjects (study & control groups) and performed under standard condition following instruction cited by tenovuo and lagerlof (9), and chemically analyzed for the detection of salivary alkaline phosphates enzyme. results table (1) is showing higher means values of plaque and gingival indices among leukemic group than control group with statistically high significant differences (p 0.01). mean value of calculus index has been shown no statistical differences between study and control groups. statistically, highly significant differences (p 0.01) were also found among study group in mean values of attachment loss (mm) and alkaline phosphatase concentration (iu/l). table 1: mean values of plaque, gingival, calculus indices, loss of attachments and alkaline phosphatase concentration among study and control groups variables patients (all) controls t-value mean± sd mean± sd pli 1.96 0.25 1.54 0.32 5.37* gi 1.83 0.39 1.43 0.31 4.18* cali 0.24 0.93 0.01 0.02 ns loss of attachment (mm) 0.63 0.48 0.09 0.23 5.29* alp (iu/l) 20.03 5.00 6.21 2.54 13.02* * highly significant (p 0.01) , df= 54 ns= not significant a high significant correlation was found for the duration of the treatment with loss of attachment and concentration of alkaline phosphatase enzyme in saliva (p 0.01) as demonstrated in table (2). this study also has been shown significant correlation between loss of attachment and concentration of alkaline phosphatase enzyme (p 0.05), table (3). table 2: correlation coefficients between duration, loss of attachment (mm) and alkaline phosphatase (iu/l) among study groups parameter loss of attachment alp duration r p r p 0.69* 0.00 0.48* 0.009 * highly significant table 3: correlation coefficients between loss of attachment (mm) and alkaline phosphatase (iu/l) among study groups parameter alp loss of attachment r p 0.44* 0.01 * significant discussion this study has been shown higher mean value of plaque index among patients with acute lymphocytic leukemia than healthy subjects which may be related to neglect or poor oral health measures, as most of patients reported their afraid from brushing their teeth due to bleeding and susceptibility to infections. previous studies showed that patients undergoing cytotoxic chemotherapy and radiation therapy often experience poor oral hygiene during and after treatment despite the supervised oral hygiene and conventional antimicrobial regimens (2,10). j bagh college dentistry vol. 25(special issue 1), june 2013 effect of pedodontics, orthodontics and preventive dentistry139 periodontal diseases are among highly prevalent oral disorders and can affect up to 90% of the worldwide population. the severity of the disease ranges from gingivitis to various classes of periodontitis and mostly due to plaque formation and accumulation which may explain the higher mean value of gingival index that observed among patients in the study group (11). it is known that a reduced salivary flow rate (due to chemotherapy induced salivary gland hypoplasia) favors dental plaque accumulation, which if left uncontrolled, may trigger periodontal inflammation in immuno-compromised patients (12). this fact could be related to the higher mean values of plaque, gingival and attachment loss recorded in this study. saliva is an important physiologic fluid that contains a highly complex mixture of substance. saliva contains locally and systemically derived biomarkers of periodontal disorders and can therefore, be recommended as patient specific diagnostic test (13). alp is very important enzyme as it is part of normal turnover of periodontal ligament, root cementum and bone homeostasis, it will be released from the damaged cells of periodontal tissues into the gingival crevicular fluid (gcf) and saliva (11). evaluation of some salivary enzymes has been used as markers for the early diagnosis of periodontal disease. higher level of alp has been demonstrated in this study among patient with leukemia which may be due to an increase in the inflammation and bone turnover rate as alp is produced by pmns, osteoblasts, macrophages, fibroblasts and plaque bacteria within periodontal tissues or periodontal pocket (13,14). the increased activity of alp is probably a consequence of destructive process in the alveolar bone in advanced stages of development of periodontal disease (5). a high significant correlation was found for the duration of the treatment with loss of attachment and concentration of alkaline phosphatase enzyme. previous studies were reported higher bone alp after chemotherapy and suggested that chemotherapy depressed bone formation and enhanced bone resorption during this period (15,16). the study also showed a significant correlation between the enzyme activity and the value of the attachment loss. this is probably a consequence of pathological processes in periodontal tissues from where this intracellular enzyme is increasingly released into saliva. in conclusion, the findings of this study showed that patients with all are at high risk of dental problems and its recommend that frequent dental examinations and intense oral hygiene program before, during and after chemotherapy are necessary in these patients. references 1. margolin jf, steuber cp, poplack dg. acute lymphoblastic leukemia. in: pizzo pa, poplack dg, eds. principles and practice oncology. 4th ed. philadelphia: lippincott williams & wilkins; 2002: 489-544. 2. javeda f, utrejab a, fernanda o. correac b, alaskara m, hudieba m, qayyumd f, al-rasheeda a, almasf k, al-hezaimia k. oral health status in children with acute lymphoblastic leukemia. critical reviews in oncology/hematology 2012; 83(3): 303– 309.(ivsl) 3. cho sy, cheng ac, cheng mj. oral care for children with leukaemia. hkmj 2000; 6: 203-8 4. desai s, shinde h, mudda j, patil v. levels of alkaline phosphatase (alp) in saliva of patients with chronic periodontitis; a clinical and biochemical study. internet j dental science 2009; 8(1): 19378238 5. randhir k, geeta s. salivary alkaline phosphatase level as diagnostic marker for periodontal disease. j int oral health 2011; 3 (5): 81-86. 6. silness j, loe h. periodontal disease in pregnancy ∏. acta odontol scand 1964; 24: 747-759. 7. loe h, silness j. periodontal disease in pregnancy 1. acta odontol scand 1963; 21: 533-551. 8. ramfjord sp. indices for prevalence and incidence of periodontal disease. j periodontol 1959; 30: 51-9. 9. tenovuo j and lagerlof f. saliva. in: thyistrup and fejerskoy, textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1996. 10. hegde am, joshi s, rai k, shetty s. evaluation of oral hygiene status, salivary characteristics and dental caries experience in acute lymphoblastic leukemia (all) children. j clin pediatr dent 2011; 35: 319– 323. 11. afsaneh r, reyhaneh s. salivary diagnosis of periodontitis status: a review. pharmacologyonline 2011; 2:1039-1054 12. gomes mf, kohlemann kr, plens g, silva mm, pontes em, da rocha jc. oral manifestations during chemotherapy for acute lymphoblastic leukemia: a case report. quintessence int 2005; 36(4): 307-13 13. numbe y, hisano a, kamoi k, yoshie h, ito k, kurihara h. analysis of saliva for periodontal diagnosis and monitoring. periodontology 2004; 40:115-119. 14. mccauley lk, nohutcu rm. mediators of periodontal osseous destruction and remodeling: principles and implications for diagnosis and therapy. j periodontol 2002; 73(11): 1377-91. 15. crofton pm, ahmed f, wade jc, stephen r, kelnar h, wallace w. effects of intensive chemotherapy on bone and collagen turnover and the growth hormone axis in children with acute lymphoblastic leukemia. journal of clinical endocrinology and metabolism 1998; 83(9): 3121-3126. 16. massey gv, dunn nl, heckel jl, chan jc, russell ec. benign transient hyperphosphatasemia in children with leukemia and lymphoma. clin pediatr (phila) 1996; 35(10):501-4. hibah.doc j bagh college dentistry vol. 28(1), march 2016 cephalometric study oral diagnosis 84 cephalometric study of iraqi adult subjects with cl i and cl iii skeletal relationships and their effects on masseter muscle thickness by using ultrasonography hibah ezzat rashid berum, b.d.s. (1) ahlam a. fatah, b.d.s., m.sc. (2) abstract background: masseter muscle is one of the most obvious muscles of mastication and considered as one indicator of jaw muscle activity. it has a major influence on the transverse growth of the midface and the vertical growth of the mandible. this study undertaken to determine the role of cephalometric analysis for discrimination between cl i and cl iii skeletal relationships, determine the role of ultrasonography in determination of masseter muscle thickness, compare masseter muscle thickness between cl i and cl iii skeletal relationships, and determine the effect of gender on masseter muscle thickness. material and method: the sample of the current study consisted of 70 iraqi subjects 40 males and 30 females with age ranging 18-25 years. they were divided into 2 groups depending on anb angle: class i skeletal relationship 20 males and 15 females and class iii skeletal relationship 20 males and 15 females. the collected sample included patients attended for different diagnostic purposes to the dental radiology department at college of dentistry/babylon university, standardized lateral cephalogram was taken to determine facial morphology, six angular and eight linear measurements were assessed. masseter muscle thickness measured ultrasonography in al-hilla general teaching hospital/ultrasonorgaphic department, in relaxation and contraction conditions for both sides. results: various parameters measured for males and females in each class and the comparison shown statistically significant differences between them (p<0.05). no difference in muscle thickness between right and left sides in the same class (p>0.05). gender variation showed significant difference in masseter muscle thickness during rest and occlusion conditions (p<0.001). conclusion: cephalometric analysis served to demonstrate the skeletal morphologies and provide a base for discrimination between class i and class iii skeletal relationships. ultrasonographic scanning is an important imaging procedure. it is reproducible and simple method for accurately measuring masseter muscle thickness. the ultrasonorgaphic study has revealed variations in masseter muscle thickness among individuals with different skeletal morphologies in each gender on one hand and between males and females in each skeletal class on the other hand. key words: masseter muscle thickness, skeletal morphology, cephalometric analysis, ultrasonorgaphic scanning. (j bagh coll dentistry 2016; 28(1):84-91). introduction masseter muscle is one of the most obvious muscles of mastication since it is the most superficial and one of the strongest. it is a broad, thick, flat rectangular muscle (almost quadrilateral) on each side of the face, anterior to parotid gland (1). thickness of masticatory muscles (especially masseter) have been measured and correlated with variables of facial morphology. muscle thickness has been considered as one indicator of jaw muscle activity (2). the masticatory muscle thickness increases with age. males have thicker masseter muscle when compared to females (3). masseter muscle thickness was measured because of the fact that in the group of masticatory muscles, the masseter muscle seems to represent the functional capacity of the masticatory apparatus and is said to have major influence on the transverse growth of the midface (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. and the vertical growth of the mandible (4), and masseter muscle is a superficial muscle and can be easily recorded on ultrasonography. however, other muscles of mastication also contribute to the interaction between muscle and facial morphology, and their influence might have biased the relation found between the masseter muscle and facial morphology (2). the ultrasonorgaphic studies revealed variations in masseter muscle thickness (both in the relaxed and the contracted state) among individuals with different skeletal morphologies. significant positive correlations also observed between masseter muscle thickness and various craniofacial parameters (5). non-invasive imaging techniques such as computerized tomography, magnetic resonance imaging (mri), and ultrasonography (us) enable measurements of the cross-section and thickness of human jaw muscles. the first imaging technique used for direct measurements of muscle size in living human subjects was ultrasonography (6). therefore, ultrasonography is used for muscle examination, especially for large superficial muscle groups (7). j bagh college dentistry vol. 28(1), march 2016 cephalometric study oral diagnosis 85 ultrasound has no ionizing radiation, no known harmful effects at the energies and doses used, in addition the technique is widely available and inexpensive (2). the image displayed on the screen has different densities in the black/white echoes and described as hypoechoic (dark) or hyperechoic . ultrasound is an attractive modality for imaging muscle and tendon motion during dynamic tasks and can provide a complementary methodological approach for biomechanical studies in a clinical or laboratory setting, towards this goal, methods for quantification of muscle kinematics from ultrasound imagery are being developed based on image . cephalometric is the scientific measurement of the dimensions of the head; cephalic pertains to head, metric means measurements, and thus cephalometric radiograph means head measurement with the x. a cephalometric analysis identifies anatomical landmarks on the film measuring the angular and linear relationships between them. this numerical assessment can provide detailed information on the relationship of skeletal, dental and soft tissue elements within the craniofacial that's why cephalometer is used to obtain standardized and comparable craniofacial images on radiographic . antero-posterior skeletal relationships are commonly defined by the relationship of the maxilla and mandible to the cranium. class i skeletal relationship defined as the condition of occlusion between maxilla and mandible in their normal antero-posterior relationship. class ііі skeletal relationship defined as the condition of occlusion in which the mandible is placed in a relatively protrusive . the current study measures and compare masseter muscle thickness and craniofacial morphology in class i and class iii skeletal relationships using cephalometric and ultrasonorgaphic investigation. materials and methods prospective study of cephalometric radiographs and ultrasonorgaphic scans taken for 70 iraqi subjects (40 males and 30 females) with age ranging (18-25 years) selected in the study sample, the collected sample included patients attended for different diagnostic purposes to the dental radiology department at college of dentistry/ babylon university, standardized lateral cephalogram was taken to determine facial morphology, six angular and eight linear measurements were assessed. masseter muscle thickness measured ultrasonography in al-hilla general teaching hospital/ ultrasonorgaphic department, in relaxed and contraction conditions for both sides. distribution of sample the subjects were divided according to the skeletal relationships into 2 groups: group a: consists of 20 males and 15 females. the subjects in this group have skeletal class i relationship with anb angle (2°-4°) and bilateral class i molar relationship based on angle's classification, in which the mesiobuccal cusp of the maxillary first molar should occlude with the buccal groove of the mandibular first molar. the incisal relationship was normal overbite and overjet (2-4 mm). group b: consists of 20 males and 15 females. the subjects in this group have skeletal class iii relationship with anb angle < 2° and bilateral class iii malocclusion based on angle's classification, in which the mesiobuccal cusp of the maxillary first molar lies posteriorly to the mesiobuccal groove of the mandibular first molar and the overbite and overjet of the anterior teeth were zero. the inclusion criteria of sample selection all subjects with skeletal class iii relationship should have dental class iii and the incisal relationship should have zero overbite and zero overjet, (edge to edge). 1. all the subjects should be free from extreme body mass index. 2. all the subjects are free from tmj problems including rheumatoid arthritis and osteoid arthritis (clinical and opg examinations). 3. all the subjects are free from cross bite, deep bite, reversed overjet, spacing, and crowding (clinically assessed by senior orthodontist). 4. no missing teeth (regardless the wisdom teeth). 5. no history of orthodontic treatment, orthopedic or facial surgical treatment. 6. no history of facial trauma or surgery. 7. no history of abnormal habits, bruxism and clinching. 8. all the subjects asked about chewing on bilateral sides, right and left, to exclude masseter muscle hypertrophy on the chewing side. body mass index (bmi): bmi is composited of weight and height that represents a summary measurement of the distribution of corporal . for each j bagh college dentistry vol. 28(1), march 2016 cephalometric study oral diagnosis 86 participant, the height (in centimeters) and the weight (in kilograms) were recorded. bmi was calculated using the equation weight/height² (kg/m²). the entire participants have normal range 18.50 24.9. methodology: patients’ preparation of radiographs: the patients were prepared for the exposure by asking them to remove any spectacles, hearing aids, and personal jewelry such as ear rings, necklaces, and hairpins, these entire things may effect on the important anatomical landmarks like ear ring may cover the articulare point. the patient was positioned within the cephalostat as shown in (figure1) with vertical sagittal plane of the head, the frankfort plane horizontal (determined visually) and the teeth were in centric occlusion, then using certain exposure factors for each gender (male and female) according to user manual. figure1:patient position for cephalometric radiography. cephalometric analysis: every lateral cephalometric radiograph was analyzed by auto cad program 2010 to calculate the angular and linear measurements after magnification was corrected, after the measurements were saved on an excel sheet with their records in degrees for angular measurement and in millimeters for linear measurements. linear measurements used in cephalometric (figure 2): 1. antigonial notch depth (and):mandibular notch depth, it represented a line drawn from gonion to menton, (go-me). 2. anterior lower facial height (alfh):a line extended from anterior nasal spine to menton, (ans-me). 3. anterior total facial height (atfh):a line extended from nasion to menton, (n-me). 4. posterior total facial height (ptfh): a line extended from silla to gonion, (s-go). 5. jarabak ratio:represented a ratio between posterior total facial height to anterior total facial height, (ptfh/atfh). 6. mandibular ramus height (mrh):a line extended from condylion to gonion, (cd-go). 7. maxillary length (max l):a line extended from point a to pterygomaxillary fissure, (a-ptm). 8. mandibular length (mand l): a line extended from condylion to gonion,(cd-gn). figure 2: linear measurements obtained from cephalometric radiography. angular measurements used in cephalometric (figure2): 1. sna: the angle between a line joining sella and nasion (s-n) and a line joining nasion and point a (n-point a). 2. snb: the angle between a line joining silla and nasion (s-n) and a line joining nasion and point b (n-point b). 3. mandibular plane angle (mp angle): the angle between mandibular plane (go-me) and frankfort plane (or-po). 4. upper gonial angle (gonial u): the angle between a line joining the ascending ramus (ar-go) and a line joining the nasion-gonion. 5. lower gonial angle (gonial l): the angle between line joining nasion-gonion and mandibular plane (go-me). 6. palatal plane/mandibular plane angle (pp-mp angle): the angle between a line joining anspns and mandibular plane (go-me). 7. saddle angle: the angle between anterior cranial base (n-s) and posterior cranial base (n-ar). 8. articular angle: the angle between posterior cranial base (s-ar) and a line joining articulare and gonion (ar-go). j bagh college dentistry vol. 28(1), march 2016 cephalometric study oral diagnosis 87 figure 3: angular measurements obtained from cephalometric radiography. patients’ preparation for ultrasonographic scanning: the muscle thickness measured ultasonographically in millimeters by asking the participant to seat in a supine position and gently turns his/her head to expose the area we need to make the measurements. a water-based gel was applied to the probe before the imaging procedure, then the transducer was held perpendicular to the surface of the skin and care was taken to avoid excessive pressure then apply the probe at a point representing the halfway between the zygomatic arch and gonial angle and this point represented the thickest part of the masseter as shown in figures (4 and 5), the imaging and measurements were performed bilaterally under rest and maximum clinching conditions; when teeth are occluding gently with muscle in a relaxed condition and during maximal clenching with the masseter muscle contracted. figure 4: right masseter muscle thickness scanning, the red arrow representing the masseter muscle thickness (mm) under rest condition, the blue arrow representing the masseter muscle thickness (mm) under occlusion condition. figure 5: left masseter muscle thickness scanning, the red arrow representing masseter muscle thickness (mm) under rest condition, and the blue arrow representing masseter muscle thickness (mm) under occlusion condition. statistical analysis: data analysis was computer aided by using spss version 21 computer software (statistical package for social sciences). results table 1 shows the difference between skeletal class i and class iii relationships in selected measurements stratified by gender. various parameters measured for males and females in each class and the comparison shown statistically significant differences between them (p<0.05), except sna°, upper gonial angle, saddle angle, articular angle, and maxillary length shown statistically non-significant differences between them (p>0.05). table 2 shows gender effect on selected measurements in each class. gender variation shown statistically non-significant differences in angular measurements between males and females in the same class (p>0.05), while the linear measurements shown statistically significant difference between males and females in the same class (p<0.05). table 3 shows right to left side differences in masseter muscle thickness in each class. the results show no difference in muscle thickness between right and left sides in the same class (p>0.05). table 4 shows effect of occlusion compared to rest stratified by gender and class. gender variation shows significant difference in masseter muscle thickness during rest and occlusion conditions (p<0.001). table 5 shows the effect of gender on masseter muscle thickness under rest and occlusion conditions in each class. the results show j bagh college dentistry vol. 28(1), march 2016 cephalometric study oral diagnosis 88 statistically significant difference in masseter muscle thickness for males and females during rest and occlusion conditions (p<0.05). table 6 shows the effect of skeletal relationships on masseter muscle thickness among males and females. the results show statistically significant differences in masseter muscle thickness in skeletal class i and class iii relationships for males and females during rest and occlusion conditions (p<0.001). table 1: difference between skeletal class i and class iii relationships in selected measurements stratified by gender male (n = 20) female (n = 15) variables p (t-test) cohen's d cl iii cl i p(t-test) cohen's d cl iii cl i mean mean mean mean 0.37[ns] 0.4 81.7 82.3 0.24[ns] 0.46 81.4 82.1 sna a ng ul ar m ea su re m en ts (° ) <0.001 1.25 81.4 79.1 <0.001 1.47 81.2 78.9 snb <0.001 1.42 23.1 25.9 <0.001 2 21.1 25.9 fmpa 0.58[ns] 0.2 52.6 52.1 0.32[ns] 0.37 52 52.8 gonial u <0.001 2.66 74.4 72.1 <0.001 1.65 73.5 71.7 gonial l <0.001 -2.21 21.5 24.8 <0.001 -2.86 21.1 24.4 pp-mpa 0.16[ns] 0.46 123.6 122.8 0.14[ns] 0.44 123.1 122.3 n-s-ar 0.75[ns] 0.2 138 137.6 0.35[ns] 0.29 138.2 137.9 s-ar-go <0.001 1.8 80.6 75.5 <0.001 2.3 78.9 71.4 and l in ea r m ea su re m en ts (m m ) <0.001 2.1 70.7 73.7 <0.001 1.84 67.1 70.7 alfh 0.008 -1.9 126.8 130.5 <0.001 2.17 120.4 124.8 atfh <0.001 1.45 92.4 87.5 <0.001 3.5 83.8 78.8 ptfh <0.001 5 0.73 0.67 <0.001 4 0.71 0.63 j-ratio 0.83[ns] 0.58 56.6 53.9 0.16[ns] 0.5 52.2 51 maxl <0.001 1.4 122.5 118.6 <0.001 1.57 121.2 117.5 mandl <0.001 1.3 64.2 62 <0.001 1.2 57.2 55.6 m ramus h table 2: gender effect on selected measurements stratified by class class iii [n = 35] class i [n = 35] variables p (t-test) cohen's d male [n = 15] female [n = 15] p(ttest) cohen's d male [n = 20] female [n = 15] mean mean mean mean 0.43[ns] 0.49 81.7 81.4 0.68[ns] 0.12 82.3 82.1 sna a ng ul ar m ea su re m en ts (° ) 1[ns] 0.46 81.4 81.2 0.7[ns] 0.14 79.1 78.9 snb 0.15[ns] 0.56 23.1 22.8 0.66[ns] 0.13 26.2 25.9 fmpa 0.19[ns] 0.44 52.6 52 0.78[ns] 0.12 52.1 51.8 gonial u 0.09[ns] 0.56 74.4 73.5 0.52[ns] 0.27 72.1 71.7 gonial l 0.1[ns] 0.46 21.5 21.1 0.1[ns] 0.4 24.8 24.4 pp-mpa 0.19[ns] 0.47 123.6 123.1 0.08[ns] 0.46 122.8 122.3 n-s-ar 0.12[ns] 0.48 138 138.2 0.89[ns] -0.29 137.6 137.8 s-ar-go 0.03 0.73 80.6 78.9 0.01 0.97 75.4 71.4 and l in ea r m ea su re m en ts (m m ) <0.001 2.1 70.7 67.1 <0.001 1.9 73.7 70.7 alfh <0.001 2.91 126.8 120.4 <0.001 1.18 130.3 124.8 atfh <0.001 2.61 92.4 83.8 <0.001 1.59 82.5 78.8 ptfh <0.001 3 0.73 0.70 <0.001 2 0.67 0.63 j-ratio 0.03 1.4 56.6 52.2 0.003 0.9 53.9 51 maxl <0.001 1.2 122.5 121.2 0.002 0.98 118.6 117.5 mandl <0.001 2.84 68.2 57.2 <0.001 1.58 62 55.5 m ramus h j bagh college dentistry vol. 28(1), march 2016 cephalometric study oral diagnosis 89 table 3: right to left side differences in mm thickness stratified by classes class iii [n = 35] class i [n = 35] variables p(t-test) rt side lt side p(t-test) rt side lt side 0.29[ns] 1.46 1.46 0.42[ns] 1.3 1.3 mm thickness-occlusion (mm) 0.74[ns] 1.24 1.24 0.45[ns] 1.09 1.09 mm thickness-rest(mm) table 4: effect of occlusion compared to rest stratified by gender and class class iii class i gender p(t-test) cohen's d occlusion rest p(t-test) cohen's d occlusion rest <0.001 4 1.43 1.26 <0.001 2.3 1.23 1.02 female [n = 30] <0.001 4.5 1.49 1.22 <0.001 2.7 1.3 1.11 male [n = 40] table 5: effect of gender on mm thickness under rest and occlusion conditions in each class class iii class i variable p(t-test) cohen's d male [n = 40] female [n = 30] p(t-test) cohen's d male [n = 40] female [n = 30] 0.02 0.9 1.29 1.25 0.02 0.9 1.13 1.08 mm-rest )mm( 0.03 1.2 1.45 1.39 0.01 1.3 1.36 1.29 mm-occ )mm( table 6: effect of skeletal relationships on mm thickness stratified by gender male [n = 40] female [n = 30] variable p(t-test) cohen's d class iii class i p(t-test) cohen's d class iii class i <0.001 2.1 1.22 1.11 <0.001 2.2 1.26 1.07 mm-rest )mm( <0.001 3.6 1.55 1.3 <0.001 3.8 1.43 1.21 mm-occ )mm( discussion the difference between skeletal class i and class iii relationships in selected measurements stratified by gender: from the results shown in table 1, we noticed that the mean value of sna and snb angles shown that the selection of subjects with class iii skeletal relationship was built on the measurements of sna and snb angles. if we consider skeletal class i subjects as a control group and compare the result of sna angle between skeletal class i and class iii relationships show statistically non-significant difference (p>0.05), while the result of snb angle between skeletal class i and class iii relationships show statistically significant difference for both males and females (p<0.05), also the maxillary length (a-ptm) for females and males in each class shown statistically non-significant differences (p>0.05), while the mandibular length (cd-gn) shows statistically significant difference for males and females in each class (p<0.05) that means the skeletal class iii relationship in our study result from protruded mandible and normal length of the maxilla. the effect of jarabak ratio (cohen’s d test) in females was (4) and males was (5) shown a highly significant differences between class i and class iii skeletal relationships because the posterior total facial height and anterior total facial height were statistically significant difference and had a strong effect (p<0.001). gender effect on selected measurements stratified by class: from the results shown, all the linear measurements were significantly higher in males than females in each class. the craniofacial skeleton of males is larger in all linear dimensions than . this finding may be attributed to the fact that maturation is attained earlier in females than males with a longer growth period in males. males had consistently larger values for linear dimensional variables, including anterior and posterior facial heights, mandibular length, and ramus . the angular measurements showed nonsignificant differences between males and females in each class. right to left side differences in masseter muscle thickness in each class: the masseter muscle thickness was scanned for both sides under rest and occlusion conditions in class i and class iii skeletal relationships showed statistically insignificant differences (p>0.05), this was because we excluded abnormal habits, bruxism, clinching, also subject sample are j bagh college dentistry vol. 28(1), march 2016 cephalometric study oral diagnosis 90 free from cross bite and crowding, and all subjects asked about chewing on bilateral sides, right and left, to exclude masseter muscle hypertrophy on chewing side. effect of occlusion compared to rest stratified by gender and class: the masseter muscle thickness increased under occlusion compared to rest conditions among males and females, this explained by huxley's sliding filament theory in 1954, the key principle behind muscle contraction is the overlapping of the actin and myosin filaments. sarcomeres represented the basic unit controlling changes in muscle length, within the sarcomere, myosin (thick filaments) slides along actin (thin filaments) to contract the muscle fiber in a process that requires effect of gender on masseter muscle thickness under rest and occlusion conditions in each class: the masseter muscle thickness under rest and occlusion conditions among males much thicker compared to that for female, this was related to a large variation in masseter muscle thickness among individuals, during both relaxation and contraction conditions due to the fact that there are differences in the fiber-type and fiber-size composition of the masseter muscle. various factors have been proposed to account for interindividual variation in fiber-type composition of skeletal muscle. some of these factors relate with the level of physical activity, genetic factors, and an influence of sex . although the fiber profile of an individual muscle results from the influence of multiple factors as mentioned above, one of the most important factors contributing to the sex difference in masseter muscle fiber-type composition may be male and female sex hormones. in female masseter muscle, type i (slow-twitch) fibers constituted a larger percentage of cross-sectional area and number than in males. whereas in the male masseter muscle, the cross-sectional area and number of type ii (fast-twitch) fibers were larger than in the female masseter other factors which may be attributed to inter-individual variation are the racial, ethnic differences, and different dietary effect of skeletal relationships on masseter muscle thickness stratified by gender: the masseter muscle thickness increased in class iii skeletal compared to class i skeletal relationships in both rest and occlusion conditions among males and females, this was because the effects of muscle thickness on bone morphology can be explained by wolff's this law states that “the internal structure and the shape of the bone are closely related to the bone's function and it also defines a relationship between the bone's shape and muscle function”, so the thickness of masseter muscle affected by ramus height due to its the mean ramus height among females with class iii skeletal relationship was (57.2mm) compared to females with class i skeletal relationship (55.6mm) and the ramus height among males with class iii skeletal relationship was (64.2mm) compared to males with class i skeletal relationship (62mm), we noticed that the ramus height in class iii was higher than the ramus height in class i skeletal relationship. according to wolff's law the muscle affected by ramus height, so that the thickness of masseter muscle will increase with increased ramus . furthermore, the orientation of the masseter muscle fibers in class iii patients compared to the controls was found to be in a more forward direction, forming an obtuse angle with the frankfort horizontal it has been suggested that the more upright the direction of the masseter muscle fibers (as in subjects with class iii skeletal relationship) in relation to the frankfort horizontal or functional occlusal planes, the greater the occlusal refferences 1. fehrenbach mj, herring sw. illustrated anatomy of the head and neck. 4th ed. cv mosby; 2012.p.110-21. 2. rohila ak, sharma vp, shrivastav pk, nagar a, singh gp. an ultrasonographic evaluation of masseter muscle thickness in different dentofacial patterns, indian j dent res 2012; 23(6):726-31. 3. premkumar s. textbook of craniofacial growth.1st ed. st. louis: cv mosby; 2011. p. 26-28, 281-3, 286-90. 4. kubota m, nakano h, sanjo i, satoh k, sanjo t, kamegai t, ishikawa f. maxillofacial morphology and masseter muscle thickness in adults. eur j orthod 1998; 20:535-42. 5. rani s, ravi ms. masseter muscle thickness in different skeletal morphology: an ultrasonographic study. indian j dent res 2010; 21(3):402-7. 6. fukunaga t. die absolute muskelkraft und das muskelkrafttraining. sportarzt sportmed 1976; 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prognathism. j dent res 2002; 81(11):752-6. 20. ariji y, kimura y, gotoh m, sakuma s, zhao yp, ariji e . blood flow in and around the masseter muscle: normal and pathologic features demonstrated by color doppler sonography. oral surg oral med oral pathol oral radiol endodontol 2001; 91:472-82. j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 19 effect of sulcular green tea extract irrigation on experimental rabbit’s gingivitis (a histopathological study) dilyar ahmed baban (1) abstract background and objective: considering the antioxidant, anti-inflammatory, and antimicrobial properties of green tea, this study aimed to evaluate the histopathological effect of the sulcular irrigation of green tea extract in the treatment of experimental gingivitis in rabbit. materials and methods: for this experimental study, 45 male rabbits, separated in two groups, control nonirrigated group (5rabbits) and study group (40 rabbits), gingivitis induced by ligatures was packed subgingivally in the lower right central incisors of the experimental group for seven days. then, the animals were randomly designated to two irrigated groups (20 rabbits for each) with 50µl/kg of distilled water and 5% green tea extract once daily for seven days starting from the day of ligature removal respectively. specimens have taken at 1, 3, 7, and 14 days for light microscopical evaluation of inflammatory cellular infiltration. results: regarding study group (5% of green tea extract), results demonstrated a significant reduction in the mean values of inflammatory cell counts within three days (p≤ 0.05) to reach the amount of control group within seven days (p˃ 0.05). a highly significant difference was detected between control group and study group sprayed with distilled water during all healing periods (p≤ 0.05). histological examination showed that the resolution of gingival inflammation, re-epithelization, and tissue healing were achieved much quicker in the group of gingival sulcular irrigation with 5% green tea extract. conclusions: in this experimental study, the histopathological analysis demonstrated that the use of 5% extract of green tea as gingival sulcular irrigation might fasten healing after the induction of gingivitis. keywords: green tea, animal model, gingival sulcular irrigation, experimental gingivitis. (received: 25/10/2019; accepted: 30/12/2019) introduction animal models have an essential role in the generation of new knowledge in medical sciences, including periodontology. these innovative models have distinct advantages because they can reproduce in vivo cellular characteristics and reactions that occur in humans. animal models in periodontal disease are particularly important in the development of the scientific basis for understanding the pathological processes.(1) gingivitis, as the multifactorial disease, is mainly derived by the interaction between invasions of causative bacteria and host immune response of varying degrees.(2) plaque induced gingivitis is the most common form of gingivitis and is induced by accumulation of microbial plaque containing more than 300 types of bacterial species (3) and characterized by gingival redness and edema.(4) gingivitis is commonly painless which rarely leads to spontaneous bleeding, and is often described by subtle clinical changes, resulting in most patients being unaware of the disease or unable to recognize it.(5) periodontal diseases are one of the oldest and most prevalent illnesses known to humanity. as long back as 4000 years ago, (1) lecturer, periodontology, college of dentistry, hawler medical university, erbil, iraq green tea is abundant in polyphenols especially catechins, which contribute up to 30% of the dry leaf weight. catechins include free catechins like catechins, gallocatechin, epicatechin and epigallocatechin and gallolyl catechins like epicatechin gallate, epigallocatechin gallate (egcg), catechin gallate and gallocatechin gallate.(7) green tea exhibits antioxidant effects on the reactive oxygen species component, which plays an essential role in periodontal destruction. coimbra et al.,(8) illustrated a significant decrease in lipid peroxidation products in the serum of green tea drinkers. they suggested that drinking green tea reduced the development or enhancement of oxidative stress thereby protecting the individual against oxidative stress diseases. a modest inverse association between the intake of green tea and periodontal disease has also shown, and the authors suggested that the application of concentrated green tea components, such as catechin may have a more beneficial effect on the periodontal condition.(9) with one such an attempt, the present research was designed to evaluate the effectiveness of 50 μl/kg of 5% green tea extract(10) sprinkled in the gingival sulcus to arrest the gingival inflammation induced by plaque accumulation in experimental gingivitis in rabbits by using a silk ligature around the lower central incisor. j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 20 material and methods rabbits and housing: forty-five healthy male rabbits were used in the study, aged about 810 months, weighing 1-1.3 kg and cared in the animal house of college of medicine, hawler medical university, erbil/ iraq by the ethical principles of animal experimentation. they have maintained on a 12-hour light/dark cycle at 20± 5°c and 20%-25% humidity. the research project has approved by the research ethics committee at the college of dentistry, hawler medical university. preparation of plant extract: an aqueous extraction of dry green tea has prepared by using five grams of dried green tea (camellia sinensis) in 100 ml distilled water, heated to a temperature of 160 f˚/ 69 c˚, and then steeped for 2 minutes. the decoction was filtered with filter paper and allowed to cool at room temperature.(11) induction of experimental gingivitis: the rabbits in the study groups (40 animals) were anesthetized by intraperitoneal administration of 4 mg/kg xylazine plus 40 mg/kg ketamine hcl(12) and placed on a proper operating table, which allowed open-mouth maintenance of the rabbits to facilitate access to the teeth. gingivitis has produced by a ligature of 4/0 non resorbable sterile thread silk placed around the cervix of the lower right central incisor for each animal and kept for seven days. the rope was knotted on the lingual side so that it remained subgingivally on the labial side and supragingival on the lingual side. the animals were switched to a soft diet, consisting of commercial food biscuits soaked in warm water for 10 min and then drained.(13) daily we performed ligatures control and checking, and if any had been lost or become loose, it would be replaced. this ligature was acted as a gingival irritant for eight days and promoted the accumulation of plaque and subsequent development of gingivitis. a periodontal evaluation was performed for the lower right central incisor by a university of north carolina (unc) periodontal probe (15 mm) to determine to bleed upon probing (bop) at four sites: distobuccal, buccal, mesiobuccal, and lingual.(14) experimental design: a total of 45 males rabbits were divided randomly into two groups as follow: the control group (5 rabbits): animals received healthy food and no ligatures, the normal gingival sulcus of nonirrigated and free from experimental gingivitis (baseline apparently healthy). study groups (40 animals): after induction of gingivitis, the animals have randomly divided into two groups (20 animals each) according to type of materials used in sulcus irrigation, distilled water gingival sulcus irrigated group and 5% green tea extract gingival sulcus irrigated group. in the distilled water treated group, a volume of distilled water (50 μl/kg b.w) equal to green tea extract (50 μl/kg b.w of 5% green tea extract) have used. sulcular gingival irrigation was performed into the midlabial area of the gingival sulcus of the lower right central incisor for once daily for seven days starting from the day of ligature removal. the depth of needle penetration was measured by adjusted stopper 5mm from the tip of the needle; the solution was injected slowly and carefully throughout ten seconds.(10) for distilled water gingival sulcus irrigated group and 5% green tea extract gingival sulcus irrigated group, five animals for each healing interval (1, 3, 7 and 14 days), were sacrificed and studied. tissue processing: at day 1,3,7, and 14, all the animals were sacrificed (5 animals each) and the mandible from each animal was taken, fixed in 10% neutral buffered formalin, decalcified in 37% hydrochloric acid, processed, sectioned in labio-lingual direction, and stained with hematoxylin and eosin. two representative tissue sections from each block were analyzed to examine the gingiva on the labial side of the tooth. analysis of the intensity of the inflammatory reaction performed by assessing the number of inflammatory cells in histological sections (h&e stained), for each animal and in four microscopic fields under x40 magnification and the gingival inflammatory scores were graded as follows(15): score 0: absence of or only discrete inflammatory cellular infiltration (from 0 to < 5 cells) score 1: mild inflammatory cellular infiltration (5 to less than 25 cells). score 2: moderate inflammatory cellular infiltration (25 to less than 125 cells). score 3: severe inflammatory cellular infiltration (more or equal to 125 cells). all analysis was blind to the origin of the sample. statistical analysis: data were analyzed using the statistical package for social science (spss, statistical for windows, version 20.0 armonk, ny: ibm corp). all data were expressed using j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 21 descriptive statistics like the mean and standard deviation±(sd) and statistical analysis using paired sample t-test. p-value of ≤ 0.05 was considered statistically significant. results animals showed no apparent signs of systemic illness throughout the study. on the third day (after surgical placement of the silk ligature around the cervix of the lower right central incisor), clinical periodontal evaluation revealed the presence of little gingival inflammation; gingival tissue began to lose its regular aspect and structure. the gingival color changed from pink to intense red. plaque accumulation was detected around the ligated silk thread including the dentogingival junction. the changes observed were accentuated from the third day until seven days from the induction of gingivitis. descriptive histology control group histological analysis of apparently healthy gingiva revealed mature squamous cell epithelium with subepithelial connective tissue region made of well-arranged bundles of collagen fibers, fibroblasts, and few inflammatory cells infiltrated the area. the dentogingival tissue did not reveal any signs of inflammatory response in the connective tissue (figure 1). study group distilled water gingival sulcus irrigation group on day 1 after one day of induction of gingivitis, the histological view of dentogingival tissues of group b1, shown moderate chronic inflammatory cell accumulation along the gingival wall with ulcerative sulcular epithelium, highly vascularized connective tissue filled with rbc and destructive of collagen fiber (figure 2). on day 3 histological findings at defect site of control group of 3 days duration shows parakeratinized oral epithelialization and scant inflammatory cells together with irregular arrangement of collagen fibers containing moderate chronic inflammatory cells mainly a few monocytes and small lymphocytes in a narrow zone at the epithelialconnective tissue interface with ulcerative sulcular epithelium, and destructive blood vessels (mild hemorrhage) (figure 3). on day7 histological section of dentogingival are showed parakeratinized oral epithelium with mild inflammatory reaction in the lamina propria directly below oral and sulcular epithelium, besides that there was ulceration of the superficial gingival tissue of sulcular epithelium due to the ligature (figure 4). on day14 histological sections showed mild inflammatory reactions in the lamina properia with irregularaligned new collagen fibers found in the interdental region of control group. however, inflammatory cells decreased, and a lot of fibroblasts were found with incomplete reepithelialization (figure 5). 5% green tea extract irrigation group on day 1 histological examination revealed moderate inflammatory response to irritation caused by ligature thread which induced significant gingival inflammation revealed abundant infiltration of inflammatory cells with slight fibroblastic activity and destructed blood vessels (mild bleeding) in the connective tissue supporting gingival epithelium. the histopathological aspect of the superficial gingival tissue in sulcular area revealed ulceration as affected by existence of the ligature (figure 6). on day 3 histological section showed mild inflammatory response with scant chronic inflammatory cells among the gingival epithelial rete pegs and deep in connective tissue. in addition, there was loose fibrous connective tissue with signs of remodeling accompanied by active fibroblasts and re epithelialization (figure 7). on days 7-14 histological section revealed no inflammatory response with sparsely scattered chronic inflammatory cells infiltration and complete epithelialization, formation of new blood vessels, and accumulation of irregular-aligned new collagen fibers. after 14 days duration, we observed no signs of inflammation in the connective tissue, dense collection of relatively well-aligned new collagen fibers, which indicated relatively complete healing of dentogingival region (figures 8 and 9). j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 22 ff figure 1: histopathological findings belong to apparently normal gingiva (control group) in rabbit showing normal histology of dentogingival area epithelial (e), fibrous connective tissue and fibroblasts (fb). h&e x20, x40. figure 2: microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of distilled water after one day showing moderate diffuse inflammatory cell infiltration, ulceration of sulcular epithelium (arrows). h&e x20, x40. figure 3: microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of distilled water after three days showing a moderate inflammatory reaction, ulcerative sulcular epithelium (arrow). h&e x20, x40. fb e j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 23 figure 4: microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of distilled water after seven days showing mild inflammatory cell, ulcerative sulcular epithelium (arrow). h&e x20, x40. figure 6: microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of 5% green tea extract after one day showing moderate inflammatory cell infiltration with slight fibroblastic activity, mild bleeding and ulcerative sulcular epithelium (arrows). h&e x20, x40. figure 5: microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of distilled water after 14 days showing shows a mild inflammatory cell with still exhibited incomplete reepithelization (arrow). h&e x20,x40 . j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 24 figure: 7 microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of 5% green tea extract after three days showing a mild inflammatory reaction, no ulcerative epithelia (e) with remodeling fibrous connective tissue (ct). h&ex20, x40. figure 8: microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of 5% green tea extract after seven days showing fibrous connective tissue (ct), scarce number of inflammatory cells (ic) (arrow) and complete epithelization. . h&e x20, x40. figure 9: microphotograph of study group treated with gingival sulcular irrigation of 50 μl/kg of 5% green tea extract after 14 days showing complete epithelization, dense fibrous connective tissue (ct). h&e x20, x40. table 1 shows descriptive statistics of inflammatory cell count/ mm2 of control and study groups at different healing periods (1, 3, 7 and 14 days) at the gingival inflammatory site. the results of the present study showed a higher number of inflammatory cells for study group sprayed with distilled water than in study group inundated with 5% of green tea extract. regarding study group (5% of green tea extract), the mean values of cell count were observed to decrease within three days to reach the amount of control group within seven days. a major significant difference was detected between control group and study group sprayed with distilled water during all healing periods, while no significant differences were observed between control group and study group sprayed with 5% of green tea extract at seven and 14 days. ct ct ic e ct j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 25 table 1: distribution of the observed inflammatory cells in different periods among the control group (healthy gingiva) and study groups irrigated with (distilled water and green tea extract). day groups number of inflammatory cells p-value day 1 healthy gingiva gingivitis/distilled water 3.8 ± 1.30 44.6 ± 5.98 .000 healthy gingiva gingivitis/green tea 3.8 ± 1.30 40.0± 3.60 .000 gingivitis/ distilled water gingivitis/green tea 44.6 ± 5.98 40.0± 3.60 .259 day 3 healthy gingiva gingivitis/ distilled water 3.8 ± 1.30 37.00± 8.86 .002 healthy gingiva gingivitis/green tea 3.8 ± 1.30 17.80± 5.63 .005 gingivitis/ distilled water gingivitis/green tea 37.00± 8.86 17.80± 5.63 .014 day 7 healthy gingiva gingivitis/ distilled water 3.8 ± 1.30 15.80± 5.26 .004 healthy gingiva gingivitis/green tea 3.8 ± 1.30 3.60± 1.140 .799 gingivitis/ distilled water gingivitis/green tea 15.80± 5.26 3.60± 1.140 .005 day 14 healthy gingiva gingivitis/ distilled water 3.8 ± 1.30 11.40± 3.646 .004 healthy gingiva gingivitis/green tea 3.8 ± 1.30 2.60± 1.516 .145 gingivitis/ distilled water gingivitis/green tea 11.40± 3.646 2.60± 1.516 .001 discussion gingivitis is one of the most prevalent diseases in humans, and many studies have used experimental animals to investigate its pathogenesis. ligature placement in the teeth has been proposed to obtain an experimental gingivitis condition more quickly than natural occurring gingivitis.(16) in this study, we achieved a stage of periodontal disease consistent with moderate gingivitis. this type of gingivitis is similar to the level of periodontal disease identified in humans. the present study used 5% of green tea extract irrigated in the gingival sulcus of rabbit’s periodontium; related to its ability to accelerate the healing of experimental rabbit’s gingivitis. findings support the beneficial effect of green tea to improve inflammatory experimental gingivitis after one week of treatment. furthermore, improvement of gingival conditions in the control group is due to the positive effects of distilled water in increasing oral hygiene. the most prominent feature of distilled water irrigated group is continuation of moderate inflammatory reaction over one week. this attributes to, in periodontal inflammation, polymorph nuclear leucocytes (pmns) produce reactive oxygen species (ros) as the initial host defense against bacterial pathogens.(17) however, excessive production of ros has determinately an effect on the host defense system.(18) in the present work, we have observed that healing repair is noticed by declining the inflammatory reaction after seven days of induction of gingivitis and irrigated by distilled water but remains through the experimentation. the actual mechanism for such reduction of inflammatory response would not explain clearly, but the following hypothesis may propose that pmns and macrophage cells contain intracellular ascorbic acid concentrations that are 10-40 times higher than plasma. high ascorbic acid level achievable in leucocytes contributes to the ability of these cells to react to inflammatory stimuli.(19) green tea has been reported to be useful for the prevention of periodontal disease and the maintenance of oral health. green tea has been found to decrease plaque formation in previous studies.(9,20) green tea is reported to prevent gathering of bacteria and thereby to prevent plaque formation on teeth.(20) green tea has shown inhibitory effect on collagenolytic enzymes, thus preventing periodontal inflammation. its catechin significantly reduces the expression of matrix j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 26 metalloproteinase-9 in osteoblasts and also inhibits the formation of osteoclast.(21) tea catechins containing the galloyl radicals possess the ability to inhibit both eukaryotic and prokaryotic cell-derived collagenase, an enzyme that plays an essential role in the disruption of the collagen component in the gingival tissues of patients with periodontal disease. green tea catechins have also been shown to inhibit protein tyrosine phosphatase in p. intermedia.(22) green tea can sequester metal ions and scavenge reactive oxygen species. studies showed that green tea might decrease several proteins involved in inflammation, including lipogenase, cyclooxygenase, nitric oxide synthase, tumor necrosis factor-α and nuclear factor-kb (nfkb), to modulate inflammation associated signals.(23) these results agree with those obtained in this study that there is an improvement in the healing process more seen in experimental gingivitis treated with a 5% green tea group. the recovery is probably due to decreased collagenolytic activity and inhibitory effect on periodontal pathogens. however, in an experimental study performed on tea polyphenols in the form of sulculer irrigation on gingival inflammation over one-week period showed that the tea polyphenols might exert a positive influence on gingival inflammation. histological review of tissue response showed that after administration of sulcular irrigation of 5% aqueous green tea extract there are marked degree of restoration and improvement of inflammatory reaction. this improvement might be explained by the fact that green tea is rich in polyphenols, but it also contains ascorbic acid (vitamin c), which could increase the green tea polyphenol antioxidant potential.(24,25) this result agreed with almost all studies that recorded reactive oxygen species would appear to play a significant role in the pathogenesis of periodontal disease.(26) morphometric analysis of gingival rabbit showed that all the changes in inflammatory reaction caused by the ligature irritant have significantly improved after administration of sulcular irrigation green tea extract. the reduction of inflammatory response indicated that a positive influence of green tea polyphenols on reduction of inflammatory response of the gingiva.(27) the present study supported the previous study performed by abdel-raheem et al.(28) who reported that green tea extract blocked cellular inflammatory process as indicated from alleviation of prevascular edema and reduction in mononuclear leucocytes inflammatory cells infiltration. conclusions the results of the current study indicated that the use of natural antimicrobial agents might prevent the formation of biofilms and treated the gingival inflammation. in comparison with distilled water, green tea showed better effects and potency because of its active phenolic ingredients or other nutritional components. histological findings revealed that 5% green tea extract as gingival sulcular irrigation in treatment of experimental model of gingivitis in rabbits might improve and fasten healing after the induction of gingivitis. acknowledgement the author would like to thank dr. saman abdulla, consultant histopathologist frcpath (uk ) ccst histopath (rcpiireland)hawler medical university , and special thanks to prof. dr. seta arshak sarkisuruk university, iraq for help reading the slides. references 1graves dt, kang j, andriankaja o, wada k, rossa c jr. animal models to study host bacteria interactions involved in periodontitis. front oral biol 2012;15:117-132. 2poosattar bejeh mir a. focusing on periodontitis as a vasculopathy: the therapeutic possibilities from the perspective of a dentistry student. j pharm biomed sci. 2011;13:1-5. 3newman mg, takei hh, klokkevold pr, carranza fa: carranza’s clinical periodontology. 12th ed. st louis: w.b.saunders elsevier; 2015. 4american academy of periodontology. the parameter on plaque-induced gingivitis. j periodontol. 2000;71:851–852 . 5blicher b, joshipura k, eke p. validation of selfreported periodontal disease: a systematic review. j dent res. 2005;84:881-890. 6loe h. periodontal diseases: a brief historical perspective. periodontol. 1993;2:7-12. 7cabrera c, artacho r, and giménez r. beneficial effects of green tea—a review. j am coll nutr. 2006;25:79-89. 8coimbra s, castro e, rocha-pereira p, rebelo i, rocha i, santos-silva s. the effect of green tea in oxidative stress. clin nutr. 2006;25:790-796. 9kushiyama m, shimazaki y, murakami m, yamashita y. relationship between intake of green tea and periodontal disease. j periodontol. 2009;80:372‑7. 10baban da, ibrahim lm, waheeda ne. the effect of gingival sulcular injection of green tea extract. biochemical, immunological and histopathological study on rabbit. 2013. phd thesis, college of dentistry, hawler medical university, iraq. 11avwioro g, lyiola s, aghoghovwia b. histological and biochemical markers of the liver of wistar rats on j bagh college dentistry vol. 32(1), march 2020 effect of sulcular 27 subchronic oral administration of green tea. n am j med sci. 2010; 2: 376–380. 12hedquist, p. anaesthesia and analgesia for surgery in rabbits and rats: a comparison of the effects of different compounds. ph.d. a thesis submitted to the karolinska institute, stockholm sweden. 2008. 13kornman ks, holt sc, robertson pb. the microbiology of ligature-induced periodontitis in the cynomolgus monkey. j periodontal res. 1981;16:363371. 14cappelli d, holt sc, singer re, pickrum hm, ebersole jl. effects of 0.12% chlorhexidine gluconate on experimental gingivitis in nonhuman primates: clinical and microbiological alterations. oral dis. 2000;6:124-131. 15accorinte m, holland r, reis a, bortoluzzi m, murates s. union of mineral trioxide cement as a pulp capping agent in teeth. j endod. 2008;34:1-6. 16giavedoni ld, chen h, hodara vl. impact of mucosal inflammation on oral simian immunodeficiency virus transmission. j virol. 2013;87:1750-1758. 17sculley dv and langley-evans sc. salivary antioxidants and periodontal disease status. proc nutr soc. 2002;61:137-143. 18das, s. and vasudevan, d. alcohol-induced oxidative stress. life sci. 2007;81:177-187. 19oberritter h, glatthaar b, moser u. effect of functional stimulation on ascorbate content in phagocytes under physiological and pathological conditions. int arch allergy appl immunol. 1986;81:46-50. 20kaur h, jain s, kaur a. comparative evaluation of the antiplaque effectiveness of green tea catechin mouthwash with chlorhexidine gluconate. j indian soc periodontol. 2014;18:178-182. 21yun jh, pang ek, kim cs, yoo yj, cho ks, chai jk. inhibitory effects of green tea polyphenol (-)epigallocatechin gallate on the expression of matrix metalloproteinase-9 and the formation of osteoclasts. j periodontal res. 2004; 39:300-307. 22poyato-ferrera m, segura-egea jj, bullón-fernández p. comparison of modified bass technique with normal toothbrushing practices for efficacy in supragingival plaque removal. int j dent hyg. 2003;1:110-114. 23caveat mk, and vollmer tr. anti-inflammatory and anti-oxidative effects of the green tea polyphenol epigallocatechin gallate in human corneal epithelial cells. mol vis. 2011; 17:533–542. 24kim jh, kang bh, jeong jm. antioxidant, antimutagenic, and chemopreventive activities of a phyto-extract mixture derived from various vegetables, fruits, and oriental herbs. food sci biotechnol. 2003;12:631–638. 25hijazi mm, khatoon n, azmi ma, rajput mt, zaidi si, perveen r, naqvi sn, rashid m. effects of camellia sinensis l. (green tea) extract on the body and testicular weight changes in adult wister rat. pak. j pharm sci. 2015;28 :249-253. 26lakshmisree s, and mythili r. antioxidants in periodontal disease. ind j multidisciplinary dent. 2011;1. 27krahwinkel t, willershausen b. the effect of sugar – free green tea chew candies on the degree of inflammation of the gingiva. eur j med res. 2000;5:463-467. 28abdel-raheim mm, enas ah, khaled ae. effect of green tea extract and vitamin c on oxidant or antioxidant. indian j clin biochem. 2009;24:280-287. ةخالصال هذه هدفت ، للميكروبات كمضادة وايضا لاللتهابات كمضاد ، لألكسدة كمضاد الشاي االخضرله خصائص عديده: واهداف البحث خلفية األرانب . في التجريبي اللثة التهاب عالج في األخضر بمستخلص الشاي الغسل تأثير الدراسة من خالل دراسه التشريح النسيجي تقييم المجموعه االولى )مجموعه : مجموعتين الى تقسيمهم وتم التجريبية الدراسة هذه في ذكرا أرانبا خمسه واربعون تم استخدام: المواد والطرق التهاب اجريت لهم ارنبا (40) الدراسة( تتالف من ( ارانب, بدون استخدام الغسل, اما المجموعة الثانيه )مجموعه5(, تتكون من ) السيطرة مجموعه الدراسه توزيع تم ، ثم بعد ذلك . أيام سبعة لمدة التجريبية للمجموعة السفلية الوسطيه اليمنى الربط تحت اللثه للقواطع عن الناجم اللثة من ٪ 5 و المقطر الماء من كغم / ميكرولتر (50) مجموعه بالغسل بمقدار وتم العالج لكل أرنبا, (20) لمجموعتين تجريبيتين عشوائي بشكل جمعت النماذج . الرباط تحت اللثه إزالة يوم من بتدأ ا يوميًا واحدة الغسل استمر لمده سبعه ايام لمرة التوالي, األخضر على الشاي مستخلص . الضوئي المجهر لتقييم النسيج تحت ( يوما 14و ايام7 , ايام3, يوم 1خالل فترات زمنيه ) بشكل تحقق األنسجة بشكل كبير قد وشفاء تكوين النسيج الطالئياللثه مع اعاده االتهاب السيطره على أن النسيجي الفحص أظهر: النتائج . األخضر الشاي بمستخلص اللثه غسل مجموعة في أسرع ، نتائج التحليل التشريحي المرضي اللتهاب اللثه في االرانب قد اوضحت, ان الغسل بمستخلص الشاي الدراسة هذه في: االستنتاجات فاء بعد تحريض اللثه على االلتهاب. % قد عجل عمليه الش5االخضربتركيز j bagh college dentistry vol. 29(2), june 2017 assessment of pedodontics, orthodontics and preventive dentistry 104 assessment of mandibular third molar position by using computed tomography and reconstructed lateral radiograph istabraq m. mohamed, b.d.s. (1) nidhal h. ghaib, b.d.s., m.sc. (2) abstract background: consideration of mandibular third molar is important from orthodontic perspective due to several factors such as, lower anterior arch crowding, relapse in lower anterior region, interference with uprighting of mandibular first and second molars during anchorage preparation and molar distalization. the aims of this study were to assess of gender differences in the mandibular third molar position and compare and evaluate whether there is any differences in the results provided by ct scan and lateral reconstructed radiograph. materials and methods: the sample of present study consisted of 39 patients (18 males and 21 females) with age range 11-15 years. ct images for patients who were attending at al suwayra general hospital/the computerized tomography department. computed tomographic images were obtained for the distance from xi point to distal surface of permanent mandibular second molar was measured in both three dimensional volumetric images and two dimensional ct derived lateral image. the statistical analyses included: means, standard deviations. paired t-test was used to compare between the two methods and independent t-test was used in verifying the genders difference. results: the results showed that there was high significant method difference between 3d ct and 2d image and gender differences was observed in values of linear measurements of present study, as males showed higher mean values than females. conclusion: there is high accuracy of measurement on ct images, so ct scan is advisable during the diagnosis and treatment plan of orthodontic cases. key words: mandibular third molar, computed tomography, lateral radiograph. (j bagh coll dentistry 2017; 29(2):104-107) introduction the third molar is a tooth that show great difference in its formation, developmental position and size compared to the other teeth in the jaws. this variability in third molars is due to the gradual dimension in the growth of the jaw bone with a consequent reduction in the space available for the teeth (1). since third molars are the last tooth to form and erupt, they will become liable to be affected by abnormalities like congenital absence, ectopic eruption and impaction (2). this has led to advise removal of the third molar bud at the age of 7-10 years when unsuccessful eruption is predicted (3). the evaluation of mandibular third molar depends on good clinical diagnosis and radiographic aid examination like periapical, panoramic and cephalometric radiograph to analyze the different factors that related to the surrounding structures such as; the amount of space available, angulation of the tooth, its height in the jaw, its relation to the mandibular second molar and to the occlusion (4). the mandibular third molar exhibits the highest rate of impaction. the rates, as reported by quiros and palma (5): ------------------------------------------------------- (1) orthodontist wasit ,ministry of health. (2) professor, depart ment of orthodontics, college of dentistry, university of baghdad.  hellman 9.5 %  björk 25 %  ricketts 50 %  richardson 35 % the ability for evaluation of the third molars position is important for dentist (6). if they erupt, they have advantage for anchorage, prosthetic abutments, or transplantation (7). if they impacted, they have disadvantage because of adjacent root resorption, inflammatory process, temporomandibular joint problem and late lower anterior crowding (8); thus early removal minimize risk to a patient as extraction later in life (9). early removal of third molar can minimize the risk of post-operative complications related to surgery on a fully developed third molar such as nerve damage with parasthesia, dry socket, inflammation, bleeding, and pain (10). thus, assessment of third molar position and its eruption is important for the patient management. materials and methods the sample of the present study consisted of 39 patients (18 males and 21 females with mean age of 13 years) who were attending at al suwayra general hospital/ the computerized tomography department, who met a special selective criteria were selected. the following criteria were used in the selection of the total sample: j bagh college dentistry vol. 29(2), june 2017 assessment of pedodontics, orthodontics and preventive dentistry 105 1iraqi arab subject their age from 11-15 years. 2normal general health status, by taking medical history from parents. 3skeletal class i relationship assessed in three planes of space(11). 4no history of dentofacial deformities, pathologic lesions in the jaws or facial trauma. 5full set of teeth with developing mandibular third molar. 6no congenital missing or supernumerary teeth 7normal overbite and over jet (2-4 mm) measured by sliding caliper (dentarum ® – germany). 8no shifting in dental midline. 9mild crowding (not more than 2 mm) measured by sliding caliper (dentarum ® – germany). 10mild spacing (not more than 2 mm) measured by sliding caliper (dentarum ® – germany). 11no previous orthodontic treatment like habits breaker or chin-cap. methods for every patient in the sample; a clinical examination and computerized tomographic imaging had been done using brilliance™ 16 ct (philips c, netherland), then the ct images were collected from the workstation of the ct unit of and the imaging data were analyzed with the software provided by the manufacturer. firstly, the mesio-distal crown dimension of mandibular 1st molar was measured clinically using vernier. this is done to compare it with the measurements obtained from the 3d and 2d images. on each image, the distances from "xi" point to the distal surface of permanent mandibular second molar (12), in both 3d and 2d images was measured. xi point: a point located at the geometric center of the mandibular ramus. location of xi is keyed geometrically to frankfort horizantal plane (fh) and perpendicular through pt (pterygoid vertical [ptv]; a line perpendicular to fh at the posterior margin of the pterygopalatine fossa), in the following steps as show in figure [1](13): 1. planes perpendicular to fh and ptv are constructed. 2. the constructed planes that tangent to points r1, r2, r3, and r4 on the borders of the ramus. r1-mandible: the deepest point on the curve of the anterior border of the ramus, one half the distance between the inferior and superior curves. r2-mandible: a point located on the posterior border of the ramus of the mandible. r3-mandible: a point located at the center and most inferior aspect of the sigmoid notch of the ramus. r4-mandible: a point on the lower border of the mandible, directly inferior to the center of the sigmoid notch of the ramus. 3. the constructed planes form a rectangle enclosing the ramus. 4. xi is located in the center of the rectangle at the intersection of the diagonals. (figure1):obtaining the location of xi point statistical analysis all the data of the sample was subjected to computerized statistical analysis using spss for windows xp. the statistical analysis included: a. descriptive statistics  means.  standard deviations.  statistical tables. b. inferential statistics paired sample t-test: it was used to compare the measurements between the ct and the reconstructed lateral view. independent sample ttest was used to verify the gender differences. results table 1 and 2 showed the descriptive statistics and gender difference of the measured variables in 3d and 2d images. generally, the mean values was slightly higher in males than females. j bagh college dentistry vol. 29(2), june 2017 assessment of pedodontics, orthodontics and preventive dentistry 106 comparing the two methods of measurements revealed highly significant difference between them in all measurement with 3d measurements slightly larger than 2d (table 3). paired sample t-test was done to detect the method difference in the mean values for the permanent mandibular first molars mesio-distal width between the direct clinical measurement and the 3d ct and 2d images. a high significant difference was found between the direct clinical measurements and the 2d image and between the 3d and 2d methods with the same mean value for the clinical and 3d methods as seen in table (4). discussion it is important to mention that direct comparisons with results from other studies will not be always possible, since this study represents the first approach to compare the 3d ct and the 2d reconstructed lateral view in the assessment of mandibular third molar position. the age of samples ranged between 11-15 years old because development of mandibular third molar was not completed at this age, early removal of third molar at this age is simple and atraumatic (12). about the distance from xi point to distal surface of permanent mandibular second molar, the result of the present study was agreed with the finding of forsberg et al. (14) and venta et al. (15) there was gender difference in the mean value of this measurement, since the mean value of this measurement in males higher than females. in present study, all the measurements on 3d and on 2d images show statistically high significant difference between them. this may be explain by that the two dimensional diagnostic imaging including the reconstructed lateral view have certain analysis limitations such as geometric distortion, superimposition of structures, rotational errors and linear projective transformation. to compare between the clinical and image method of measurement, the mean value of the width of mandibular 1st molar measured clinically and by 3d image is coincide, while it is about 0.8 mm smaller than 2d image. this result gives an impression about the accuracy of 3d image in measurement and diagnosis of orthodontic problems. although the method difference is statistically significant but clinically is of no value (0.3). table 1: descriptive statistics and gender difference for the variables measured in 3d image measurements descriptive statistics gender difference (d.f.=37) total sample (n=39) males (n=18) females (n=21) mean s.d. mean s.d. mean s.d. mean difference t-test p-value xi to 7(mm) 19.98 0.77 20.02 0.83 19.96 0.72 0.06 0.24 0.812(ns) table 2: descriptive statistics and gender difference for the variables measured in 2d image measurements descriptive statistics gender difference (d.f.=37) total sample (n=39) males (n=18) females (n=21) mean s.d. mean s.d. mean s.d. mean difference t-test p-value xi to 7(mm) 18.74 0.81 18.77 0.80 18.71 0.83 0.06 0.20 0.843(ns) table 3: descriptive statistics and image difference for the variables measured measurements descriptive statistics image comparison (d.f.=38) 3d image 2d image mean s.d. mean s.d. mean difference t-test p-value xi to 7 19.98 0.77 18.74 0.81 1.25 34.47 0.000 (hs) j bagh college dentistry vol. 29(2), june 2017 assessment of pedodontics, orthodontics and preventive dentistry 107 table 4: descriptive statistics and measurements difference for the md width of permanent mandibular first molars md of 6 measurement descriptive statistics measurements difference (d.f.=38) mean s.d. mean difference t-test p-value 3d image 10.28 0.31 0.80 125.73 0.000 (hs) 2d image 9.48 0.30 clinical 10.28 0.32 -0.001 -0.007 0.994 (ns) 3d image 10.28 0.31 clinical 10.28 0.32 0.799 11.531 0.000 (hs) 2d 9.48 0.30 references 1. bindayel a. the role of third molar in orthodontic treatment. pakistan oral & dental j 2011; 31(2): 3747. 2. hellman m. our third molar teeth, eruption, presence and absence. dent cosmos 1936; 78: 750-62 3. ricketts, rm, roth, rh, chaconas, sj, schulhof, rj, engel, ga. orthodontic diagnosis and planning. in: rocky mountain/orthodontics, denver, colorado; 1982:243–260. 4. laskin dm. evaluation of third molar problem. jada 1971; 82: 824-8. 5. quiros j, palma a. the mandibular third molar: a method for predicting its eruption. ortho j 1999; 2(4): 8-15 6. qamruddin i, qayyum w, mahmood s, wasif s, rehan f. differences in various measurements on panoramic radiograph among erupted and impacted lower third molar groups. j pak med assoc 2012; 62(9): 883-7. 7. hattab fn, alhaija es. radiographic evaluation of mandibular third molar eruption space. oral surg oral med oral pathol oral radiol endod 1999; 88: 285-91. 8. daley td. third molar prophylactic extraction, a review and analysis of the literature. gen dent 1996; 44: 310-2. 9. venta i, murtomaa h, ylipaavalniemi p. a device to predict lower third molar eruption. oral surg oral med oral pathol oral radiol endod 1997; 84: 598603. 10. niedzielska ia, drugacz j, kus n, kreska j. panoramic radiographic predictors of mandibular third molar eruption. oral surg oral med oral pathol oral radiol endod 2006; 102: 154-8. 11. foster td. a textbook of orthodontics. 3rd ed. oxford; london: blackwell scientific publications; 1990. p. 83-5. 12. ricketts rm. third molar inoculation: diagnosis and technique. j calif dent assoc 1976; 4:52-7. 13. bjork a, jensen e, palling m. mandibular growth and third molar impaction. acta odonto scand 1956;14:231-72. 14. forsberg cm, vingren b, wesslen u. mandibular third molar eruption in relation to available space as assessed on lateral cephalograms. swed dent j 1989; 13(1-2): 23-31. 15. venta i, murtomaa h, turtola l, meurman j, ylipaavalniemi p. assessing the eruption of lower third molars on the basis of radiographic features. br j oral maxillofac surg 1991; 29: 259-62. المستخلص رجوع من الضروري االخذ بنظر االعتبار موقع سن العقل االسفل من الناحیھ التقویمیھ وذلك لعدة عوامل منھا ازدحام االسنان االمامیھ السفلى, وتداخل مع عالج االضراس السفلى. الحالھ في المنطقھ االمامیھ السفلى بعد العالج لعقل األسفل ومالحظھ الفرق بالنتائج بین الجنسین بواسطھ االشعة ثالثیھ االبعاد واالشعة الجانیھ ھذا البحث یھدف الى تحري ومقارنھ موقع سن ا ثنائیھ االبعاد المصنعھ بواسطھ جھاز المفراس الحلزوني. )سنة وقد تم 1511لقد تم فحص وتشخیص تسعھ وثالثین مریضا (ثمانیھ عشر من الذكور واحدى وعشرین من االناث) وباعمار تراوحت ما بین ( (تم تقیمھا باستخدام االشعھ المقطعیھ ثالثیھ االبعاد) والطریقھ الثانیھ (تم تقیمھا باستخدام االشعھ الجانبیھ المصنعھ تقیمھم بطریقتین:الطریقھ االولى ثنائیھ االبعاد) وقد تم اخذ التقیم االتي لكل طریقھ: المسافھ من المركز الھندسي لعظم الفك االسفل الى اقصى الضرس الثاني االسفل. المعدل الحسابي بالنسبھ للجنس,حیث تبین ان المعدالت الحسابیھ للقیاسات الماخوذه للذكور اعلى من االناث.لقد ظھر وجود فرق ب ه الدراسة.كذلك لوحظ وجود اختالفات ذوات اھمیھ احصائیھ ما بین االشعھ الثالثیھ االبعاد والثنائیھ االبعاد فیما یتعلق بالقیاسات المتعلقھ بھذ الدراسھ ان االشعھ الحلزونیھ ثالثیھ االبعاد توفر معلومات دقیقھ وقیمھ, لھذا ننصح باستخدام المفراس المقطعي الحلزوني تبین وفقا لنتائج ھذه الثالثي االبعاد خالل التشخیص والتقیم العالجي لحاالت التقویم. abbas.doc j bagh college dentistry vol. 28(1), march 2016 the effect of basic sciences 169 the effect of multi-wall carbon nanotubes on the microhardness of the tooth enamel mohammed k. jawad, b.d.s. (1) abbas f. ali, b.d.s., ph.d. (2) abstract background: the objectives of this study are to evaluate the effect of addition of multi-wall carbon nano tubes (mwcnts) of different concentrations (0.05 mg.ml-1,0.25 mg.ml-1,0.5 mg.ml-1and1 mg.ml-1) on dimethyl sulphoxide dmso and distilled water (dw) on tooth enamel. it intends to evaluate enamel microhardness in (kg. m-2) pre and post the application of multi-wall carbon nano tubes (mwcnts). materials and methods: thirty specimens prepared for the present study to measure the hardness of the enamel. results: the results showed that a significant increase in the enamel microhardness for groups 0.05 mg/ml (group b), 0.25 mg/ml (group c), 0.5 mg/ml (group d) and 1 mg/ml (group e) compared with control group (group a) in dimethyl sulphoxide media. also, the results showed a significant increase in the enamel microhardness for polished samples compared with unpolished samples in dmso media. conclusion: the final conclusion highest mean value obtained was 1 mg/ml (group e) in the enamel microhardness suspension in and dimethyl sulphoxide media. key words: multi-wall carbon nano tubes, enamel hardness. (j bagh coll dentistry 2016; 28(1):169-173). introduction enamel, the outer hard tissue layer of tooth crowns, is a composite material that comparable to other biological tissues like bone or dentin exhibits a unique and complex hierarchical structure (1). the bulk of human teeth consists of two main mineralized tissues, collagen-rich dentine and highly mineralised enamel. they join formulating of a complex and mechanically durable dentine–enamel junction (dej) that contributes to the lifelong success of the tooth structure under thermo-mechanical loadings encountered in the oral cavity under the conditions such as mastication, chemically active environment and thermal shock (2, 3). enamel is the hardest tissue in the human body and is considered a nanostructured biocomposite in which its mineral phase predominates (95-96 wt. %) (4). in this mineral portion, large hexagonal carbonated hydroxyapatite crystals are tightly packed creating prisms with a keyhole-like structure of about 5 µm in diameter (5). prisms are aligned and run approximately perpendicular from the dentin-enamel junction to the tooth surface (3). each prism is separated from each other by a nanometer-thin layer of a protein-based organic matrix (6). the term “nano” is derived from the greek word “dwarf ”.(8) more simply speaking, one nanometer is one-billionth or 10-9 of a meter(7-9). nanotechnology can be classified in terms of application into three broad and extensively overlapping categories (10) they are: nanoelectronics, nanomaterials/particles and nano-biotechnology. (1)master student, department of basic science, college of dentistry, university of baghdad. (2)assist. professor, department of basic science, college of dentistry, university of baghdad. carbon nanotubes (cnt) are a new crystalline form of carbon. wound in a hexagonal network of carbon atoms constituting a graphene nanofoil, hollow cylinders can have diameters as small as 0.7 nm with lengths that can be ranged from a few micrometres to several millimeters in length (11). each end can be opened or closed by a fullerene half molecule. these nanotubes can have a single layer (swcnt for single walled carbon nanotube) or several layers (mwcnts for multi walled carbon nanotube) of coaxial cylinders of increasing diameters in a common axis. multilayer carbon nanotubes can reach diameters of 100 nm (12). enamel surface microhardness refers to a tooth’s resistance to scratching, abrasion, and indentation. a substantial number of mineral ions can be removed from hydroxyapatite latticework without destroying its structural integrity; however, such demineralized enamel transmits hot, cold, pressure and pain much more readily than normal enamel. microhardness tests are commonly used to study the physical properties of materials, and they are widely used to measure the hardness of teeth (13, 14). the hardness of knoop (khn) and vicker (vhn) reported approximately the same value (15). the average hardness value of enamel and dentin is between 270 to 350 knoop microhardness or from 250 to 360 vickers microhardness and from 50 to 70 knoop microhardness respectively (16). materials and methods activation of commercial carbon nano tube(17). one gram of multi-wall carbon nano tubes was transferred into a glass beaker and (10 j bagh college dentistry vol. 28(1), march 2016 the effect of basic sciences 170 cm3) of nitric acid were added. then (30cm3) of sulphuric acid were added drop wise to the mixture and placed in two-neck round bottomed flask enquired with a condenser to continue stirring and heated to 50 ◦c for 24 hrs after which the mwcnts were filtered off using cellulose filter paper (pore size 0.45 micrometer). followed by subsequent washing with distilled water until the ph was almost neutral. the mwcnts were then dried under vacuum at room temperature. then dried in furnace oven set at 150◦c for 2hr. in the third step 0.02 g from mwcnts were put in 20 ml dw and dmso. the mwcnts did not mixed with dw instead formed a suspension, while the mwcnts are properly mixed with dmso. the whole solution is transferred into sonicator. teeth specimens preparation the total number of samples were 54 (24 samples in dw and 24 samples dmso in different concentrations and 6 samples control) from mandibular first premolar for micro hardness test were prepared. samples divided the microhardness samples into polished samples and unpolished samples and was polishing the polished samples by hand piece device with pumice material and repeat the polishing more than once until the surface become roughness. samples were collected from healthy teeth of female patients attending a dental teaching hospital at the university of baghdad collage of dentistry, also thi-qar specialized dental center in department of orthodontics of the ages ranging between 15 24 years. the first selection criterion for the sample was tooth quality. only teeth with no visible defects were selected, not taking into account any damage at the micro structural level. they were without any caries, no attrition or erosion. the patients were non-smokers and do not consume alcoholic beverages. all samples we kept in water for further tests. the samples were shaken in the vibrator for limited period of time ten minute for three times in six continuous days. the hardness of a material the hardness of a material its resistance to penetration under a localized pressure or resistance to abrasion. the baseline of the hardness of base lines was measured through the use of micro -vickers hardness testing machine (cv-400 dm, europe) (figure1), with a load of 500 g and 1000 g, in 5 seconds. principle of hardness determination the micro hardness test involves a microscopic and static method, of which the results are mostly expressed in terms of vickers and knoop hardness numbers. the micro hardness tester is provided with an optical magnifying system. the hardness is determined by penetrating a diamond pyramid indenter under a known test force into the surface of test piece and then measuring the diagonal of the indentation left on the surface after removal of the test force. the hardness number is calculated upon the below equations: vickers test: hv= 1854 f/d2. where hv: vickers hardness number, in kg .m-2, f: test force, in kg, d: diagonal length of the indentation, in m2. figure 1: micro-vickers hardness testing machine (cv-400 dm). sample preparation to measure the hardness the total number of samples was 54 samples to measure the hardness of the enamel, the group is divided into subgroups as follows: control group (a): (3 unpolished enamel surface and 3 polished enamel surface samples). group b (0.05 mg/ml): (3 unpolished enamel surface and 3 polished enamel surface samples in dw) and (3 unpolished enamel surface and 3 polished enamel surface samples in dmso). group c (0.25 mg/ml): (3 unpolished enamel surface and 3 polished enamel surface samples in dw) and (3 unpolished enamel surface and 3 polished enamel surface samples in dmso). group d (0.5 mg/ml): (3 unpolished enamel surface 3 polished enamel surface samples in dw) and (3 unpolished enamel surface and 3 polished enamel surface samples in dmso). group e (1 mg/ml): (3 unpolished enamel surface and 3 polished enamel surface samples in dw) and (3 unpolished enamel surface and 3 polished enamel surface samples in dmso). j bagh college dentistry vol. 28(1), march 2016 the effect of basic sciences 171 statistical analysis statistical analysis was done by using the software spss version 17.0; the results were expressed as mean ± standard deviations (mean ± sd). one way anova was used to compare parameters in different studied groups. p-values (p < 0.01) were considered statistically significant. results statistical analysis of the results used to evaluate enamel hardness in (kg.m-2) after mwcnts application with dmso in different concentration treatment. enamel hardness test control group compared with groups dealing with mwcnts application with dmso in different concentration treatment and different surfaces treatment (fig. 2,3). enamel microhardness test in difference groups table (1) showed that the results of lsd test after anova a statistically highly significant differences among groups (a compared with b, c, d, e), (b compared with c, d, e), (c compared with e only but compared with d a statistically significant differences) and (d compared with e) in unpolished state in dw media, and also a statistically highly significant differences among groups (a compared with b, c, d, e), (b compared with c, d, e) , (c compared with e only but compared with d a statistically significant differences ) and (d compared with e) in polished state in dw media. in dmso media a statistically highly significant differences among all groups in unpolished state and polished state. figure 2: the enamel microhardness in (kg.m-2) after mwcnts application with dw media figure 3: the enamel microhardness in(kg.m-2)after mwcnts application with dmso media. j bagh college dentistry vol. 28(1), march 2016 the effect of basic sciences 172 table 1: lsd test and anova of enamel microhardness state groups media d.w. dmso mean difference p-value mean difference p-value unpolished a b -26.03 0.000 (hs) -65.97 0.000 (hs) c -54.00 0.000 (hs) -107.37 0.000 (hs) d -62.97 0.000 (hs) -148.97 0.000 (hs) e -79.83 0.000 (hs) -177.00 0.000 (hs) b c -27.97 0.000 (hs) -41.40 0.000 (hs) d -36.93 0.000 (hs) -83.00 0.000 (hs) e -53.80 0.000 (hs) -111.03 0.000 (hs) c d -8.97 0.019 (s) -41.60 0.000 (hs) e -25.83 0.000 (hs) -69.63 0.000 (hs) d e -16.87 0.000 (hs) -28.03 0.000 (hs) polished a b -27.37 0.000 (hs) -82.30 0.000 (hs) c -49.33 0.000 (hs) -125.70 0.000 (hs) d -58.23 0.000 (hs) -150.17 0.000 (hs) e -85.50 0.000 (hs) -207.63 0.000 (hs) b c -21.97 0.000 (hs) -43.40 0.000 (hs) d -30.87 0.000 (hs) -67.87 0.000 (hs) e -58.13 0.000 (hs) -125.33 0.000 (hs) c d -8.90 0.046 (s) -24.47 0.009 (hs) e -36.17 0.000 (hs) -81.93 0.000 (hs) d e -27.27 0.000 (hs) -57.47 0.000 (hs) discussion based on the findings of the current study, the average value of vickers enamel microhardness was 334.87 ± 2.91, which is similar to the findings of panich and poolthong (18), enamel hardness depends on different factors such as degree of enamel mineralization, enamel prisms and enamel tufts variations in different areas of enamel, presence or absence of any structural defects in the enamel, type of the teeth (whether it is anterior or posterior), and procedures of preparing the samples to perform the hardness test(13). other factors influencing enamel hardness are the bio environmental factors, fluoridation of the drinking water, age of the teeth, and different eating habits in different societies (19). enamel microhardness in difference groups the results of the microhardness are reported in table (1) showed that the results of lsd test after anova have a statistically highly significant differences among groups (a compared with b, c, d, e) , (b compared with c, d, e) , (c compared with e only but compared with d a statistically significant differences ) and (d compared with e) in unpolished state in dw media, and also a statistically highly significant differences among groups (a compared with b, c, d, e) , (b compared with c, d, e) , (c compared with e only but compared with d a statistically significant differences) and (d compared with e) in polished state in dw media. in dmso media a statistically highly significant differences among all groups in unpolished state and polished state. peter atkin`s and julio de paula (20) described that the well-known cnts are thin cylinders of carbon atoms that mechanically strong. the intentional integration of two or more distinct materials into one composite material would make use of preferred properties of each material. the mwcnts reported to be the stiffest and strongest fibers ever produced with young’s modulus reach up to 1 tpa experimentally four times stronger than steel. the hexagonal structure with a separation of planes is about 0.353 nm which will enables those tubes to penetrate as deep as many micrometers inside the teeth enamel rods. at the same time, the increase in microhardness is due to the increase in concentration of mwcnts. the tremendous surface area of cnts is up to 200 m2.g-1 which leads to formation of clusters due to van der waals forces. clustering and non-uniform dispersion of cnts will lead to inhomogeneous property distribution in the structural component(21) as shown in figure (4). j bagh college dentistry vol. 28(1), march 2016 the effect of basic sciences 173 a b figure 4: sem: a: unpolished sample with mwcnts, b: polished sample with mwcnts in 5μm. references 1. sabine b, stefan h, arndt k, theo f, gerold as. the fracture behaviour of dental enamel. biomaterials 2011; 31: 375-84. 2. marshall sj, balooch m, breunig t, kinney jh, tomsia ap, inai n, watanabe lg, wu-magidi ic, marshall gw. human dentin and the dentin–resin adhesive interface. acta mater1998; 46: 2529–39. 3. ten cate ar. oral histology: development, structure and function. st. louis: mosby; 1994. 4. robinson c, connell s, kirkham j, shorea r, smith a. dental enamel-a biological ceramic: regular substructures in enamel hydroxyapatite crystals revealed by atomic force microscopy. j mater chem 2008; 14: 2242-8. 5. habelitz s, marshall sj, marshall gw, balooch jr. mechanical properties of human dental enamel on the nanometre scale. arch oral biol 2001; 46: 173183. 6. cuy jl, mann ab, livi kj, teaford mf, weihs tp. nanoindentation mapping on the mechanical properties of human molar tooth enamel. arch oral biol 2002; 47: 281-91. 7. kaehler t. nanotechnology: basic concepts and definitions. clin chem 1994; 40: 1797-9. 8. schleyer tl. nanodentistry. fact or fiction? j am dent assoc 2000; 131: 1567-8. 9. lahn j. nano’s big future: nanotech –national geographic. 2006. 10. majumder dd. iete technical review. 2007; 24: 9-25. 11. hett a. nanotechnology: small matters, many unknowns. swiss reinsurance company 2004; 57; 123-56. 12. aitken rj, creely ks, tran cl. nanoparticles: an occupational hygiene review, institute of occupational medicine, health and safety executive (hse), uk, research report 2004; 41: 274. 13. attin t, meyer k, hellwig e, buchalla w, lennon am. effect of mineral supplements to citric acid on enamel erosion. arch oral biol 2003; 48(11): 753-9. 14. chunmuang s, jitpukdeebodintra s, chuenarrom c, benjakul p. effect of xylitol and fluoride on enamel erosion in vitro. j oral sci 2007; 49(4): 2937. 15. ryge g, foley de, fairhurst cw. microhardness and chemical composition of human tooth. j dent res 1961; 40: 1116-1121. 16. meredith n, sherriff m, setchell dj, swanson sav. arch oral biol 1996; 41: 539-45. 17. salipira kl, mamba bb, krause rw, malefetse tj, durbach sh. cyclodextrin polyurethanes polymerised with carbon nanotubes for the removal of organic pollutants in water. water sa 2008; 34: 113-8. 18. panich m, poolthong s. the effect of casein phosphor peptideamorphous calcium phosphate and a cola soft drink on in vitro enamel hardness. j am dent assoc 2009; 140: 455-60. 19. potocnik i, kosec l, gaspersic d. effect of 10% carbamide peroxide bleaching gel on enamel microhardness, microstructure, and mineral content. j endod 2000; 26: 203-6. 20. peter atkin’s and julio de. p. atkin’s physical chemistry 2006; 720-725. 21. agarwal a, bakshi sr, lahiri d. carbon nanotubes reinforced metal matrix composites. new york: crc press taylor and francis group; 2011. j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 45 treatment of recurrent aphthous ulceration by mastic orabase tagreed altaei, b.sc., m.sc., ph.d. (1) abstract background: recurrent aphthous ulcer is a chronic inflammatory disease of the oral mucosa. substance p has activity in the inflammatory response. transforming growth factor beta (tgf-β) as immune-modulators regulates the immune response and has anti-inflammatory, pro-inflammatory effects. pistacia lentiscus (mastic) of anacardiaceae family have pharmacological activities like anti-inflammatory, antioxidant, and used in treatment of wound and repair. the aim of this study is to find the safety and efficacy of a new product mastic orabase; experimentally and clinically. methods: this research studied two parts: first; experimentally for assessment of mastic orabase effects on rabbit dermal irritation, efficacy of mastic orabase on the induced ulceration, with histopathology of rabbits’ tissues, and safety: therapeutic index and safety factor. second; clinical efficacy of mastic orabase on the healing of rau by assessment of ulcer size reduction, inflammation, healing time, pain, saliva substance p and tgf-β levels in rau patients, and monitoring for any adverse effects or adverse drug reactions. results: experimental study of topical mastic orabase treatment showed significant reduction of inflammation and ulcer size, healing time. safety of mastic orabase was confirmed by no dermal irritation, no toxicity, and wide therapeutic index range. clinical study showed reduction of inflammation, ulceration, healing in short time, pain was relieved from the first topical dose, and the anti-inflammatory activity of mastic orabase was confirmed by reduction of salivary substance p and tgf-β elevation. conclusion: mastic orabase showed dose-dependent efficacy in the treatment of recurrent aphthous ulceration, short healing time. this may be related to effect of mastic orabase on proinflammatory and anti-inflammatory mediators; substance p and tgf-β. key words: mastic orabase, rau, substance p, tgf-β. (j bagh coll dentistry 2017; 29(3):45-53) introduction recurrent aphthous ulcer (rau) is one of the most painful oral mucosal inflammatory ulcerative conditions and can cause pain on eating, swallowing and speaking (1). a prodromal localized burning or pain for 24 to 48 hours can precede the ulcers. the lesions are painful, clearly defined, shallow, round or oval, with a shallow necrotic center covered with a yellow-grayish pseudomembrane and surrounded by raised margins and erythematous haloes. the pain lasts for three to four days, at which point early epithelialization can occur (2). substance p (sp) is an undecapeptide member of the tachykinin neuropeptide family. it is a neuropeptide, acting as a neurotransmitter and as a neuromodulator (3), it's closely related neurokinin a (nka) are produced from a polyprotein precursor after differential splicing of the preprotachykinin a gene. the neuropeptide substance p is widely distributed in the central and peripheral nervous system including the skin (4); it is capable of inducing a number of inflammatory responses including vasodilatation, plasma extravasation, leukocyte activation, endothelial cell adhesion molecule expression, cellular cytokine production, and mast cell activation (5). (1)assistant professor, college of dentistry, hawler medical university these sp pro-inflammatory effects are mediated by the neurokinin receptor 1 (nk1r) (3,4). its proinflammatory effects in immune and epithelial cells and participates in inflammatory diseases. also stimulate cell growth in normal and cancer cell line cultures (6), and it could promote wound healing of non-healing ulcers in humans (7), and its induced cytokines promote multiplication of cells required for repair or replacement, growth of new blood vessels (8). the tgf-beta superfamily encompasses a diverse range of proteins, many of which play important roles during development, homeostasis, disease, and repair (9). mastic is a white, semitransparent, natural resin that is obtained as a trunk exudate from mastic trees. scientific name is pistacia lentiscus, of the anacardiaceae family (10). the essential oil extracted from the aerial parts has been proven to exhibit antioxidant, anti-inflammatory, antimicrobial, antifungal (11) and anti-atherogenic activities (12). mastic gum has been used in clinical trials on patients with peptic ulcers; the administration of mastic (1 g daily) relieved the pain and healed the stomach and duodenal ulceration in the majority of the patients within 2 weeks (13). mastic gum has bactericidal activity on h. pylori in vivo. mastic gum kills helicobacter pylori, at concentrations as low as 0.06 mg/ml. the effect of mastic has been studied on j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 46 experimentally induced gastric and duodenal ulcers in rats. mastic at an oral dose of 500 mg/kg produced a significant reduction of gastric secretions, protected cells, and reduced the intensity of gastric mucosal damage. the in vitro antimicrobial activity of p. lentiscus extracts has also been tested on bacteria and fungi (13). concerning internal use of mastic oil, tests of repeated toxicity via rectal route, showed that mastic oil is well tolerated with no adverse effect neither on liver nor renal functions; rabbits subjected to six consecutive weeks of oil administration, showed no anatomical or blood biochemical variations of biological signification toxicity (14).in dentistry, mastic acts as an oral antiseptic and tightens the gums, and for that reason it is used in toothpastes and chewing gums. the essential oil of mastic gum is also used in perfumery and in the cosmetic industry (creams and other facial products) (15). the aims of this study are: 1-effects of mastic orabase on rabbit dermal irritation. 2-efficacy of mastic orabase on the induced ulceration. 3microscopical histopathology of rabbits’ tissues. 4-safety: therapeutic index and safety factor. 5clinical efficacy of mastic orabase on the healing of rau patients; ulcer size reduction, healing time, pain. 6-saliva substance p level of rau subjects: 7-saliva tgf_beta level of rau subjects: 8-adverse effects or adverse drug reactions. methods the study protocol was approved by the ethics committee of the college of dentistry/hawler medical university. formulation of orabase the orabase was prepared according to pharmacopoeia (16) under aseptic conditions. the required weights of dried pectin, sodium carboxymethyl cellulose, gelatin, methyl paraben, and propyl paraben were added gradually to form a homogenous orabase. the measured quantity of mastic oil was added to the orabase gradually with continuous stirring till homogenous orabase was attained. the mastic orabase was poured into the collapsible tubes, closed properly and stored in dry cool place. placebo was prepared as above but free of the active constituent. effects of mastic orabase on rabbit dermal irritation primary irritation to the skin was measured by a patch-test technique on the intact skin of the albino rabbit in accordance with the guidelines of the consumer product safety commission, title 16, chapter ii, part 1500. the backs of the rabbits were clipped free of fur with an electric clipper at least 4 h before application of the sample. introduction under a square patch of surgical gauze measuring 1 inch by 1 inch and two single layers thick, the tests orabase and placebo were applied topically on the back of the animals. the animals were immobilized with patches secured in place by adhesive tape. the first evaluation was made after 1 h, then the entire trunk of the animal is wrap with a rubberize cloth, for the 24 h period of exposure. after 24 h of exposure, the patches were removed and the resulting reactions were evaluated on the basis of the designated values for erythema and oedema with the draize scoring criteria. readings were again made at the end of 48, and 72 h. the primary irritation index (p.i.i.) was calculated following test completion. material producing a p.i.i. score of greater than or equal to 5.00 was considered positive; the material was considered a primary irritant to the skin. efficacy of mastic orabase on the induced ulceration this study involving animals followed the institutional and national guide for the care and use of laboratory animals. new zealand albino rabbits (oryctolagus cuniculus) of both sexes were used to assess the efficacy of 3 concentrations (5, 10, and 15%) of mastic orabase (on the induced ulcers. the mucosal injury was performed on both cheek pouches, under ether anaesthesia by two methods (six rabbits for each): in the first method, the buccal surfaces of the animals were exposed for 20 seconds to contact with glacial acetic acid, using a plastic tube of 4 mm in diameter. this produce an immediate mucosal necrosis within the affected area followed 2 days after (designed as ulceration day 0) by the development of a chronic ulcer with a well-define crater, which normally heals within 10 days. in the second method, the ulcer in the buccal mucosa of the rabbit’s cheek pouch was induced by surgical incision and exposed for 20 seconds to contact with aspirin (100 mg/kg); chemicals such as aspirin that are held or that come in contact with the oral mucosa may cause tissues to become necrotic and slough off creating an ulcerated surface. the animals were examined by measuring the size of the ulcer using a calibrated probe; signs of inflammation, oedema, and erythema were assessed. microscopical histopathology of rabbits’ tissues j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 47 the cheek pouch was collected and placed in 10% formalin solution for at least 24 hours, then prepared for light microscope examination. the parameters to examine; histopathological alterations, state of epithelial proliferation, type of inflammatory cells, fibrous tissues state, and number of blood vessels in the connective tissue under the microscope. safety: therapeutic index and safety factor: this was assessed by measuring the toxicity and mortality of animals to calculate the therapeutic index (ti) and safety factor using the following formulas: therapeutic index= td50/ed50 where td is toxic dose, and ed is effective dose at 50% of animales. safety factor = td1 / ed99 where td is toxic dose at 1%, and ed is effective dose at 99% of animales (17). clinical efficacy of mastic orabase on the healing of rau this study involving human subjects is in accordance with the helsinki declaration of 1975 as revised in 2000 and that it has been approved by the relevant institutional ethical committee. a prospective randomized double blind; placebo controlled study was performed. the subjects were divided randomly into 2 groups: 3 concentrations of mastic orabase treatment group and a placebo group. the tests concentrations and placebo were applied topically on the ulcerated areas 3 times daily for 5 days. the assessed parameters were ulcer size reduction, healing time, tolerance, and pain reduction by comparative pain scale and memorial pain assessment. the efficacy indices (ei) of the ulcer size improvement was calculated with the following formula (v4 and v7 refer to the values measured at day 5 visit and day 7 visit, while v1 refers to the baseline value measured before the study entry): ei = ([v4 or v7−v1] / v1) × 100%. the ei were evaluated on a 4-rank scale: [heal: ei = 100%, marked improvement: 100% >ei ≥70%, moderate improvement: 70% >ei ≥30%, no improvement: ei <30%. saliva substance p level of rau patients substance p levels in saliva samples were assessed according to kit procedure. saliva tgf_beta level of rau patients tnf-beta levels in saliva samples were assessed according to kit procedure. adverse effects or reaction monitoring for the presence of any adverse effects or adverse reaction. statistical analysis results are presented as mean ± sd or percentage (%). statistical significance was calculated by comparing results by t test or linear regression analysis. anova, chi-square, fisher exact test. a p value less than 0.05 were considered statistically significant, aided by spss software. results effects of mastic orabase on rabbit dermal irritation dermal irritation test of mastic orates showed no erythema or oedema on the intact sites, for placebo group; some animals had very slight erythema after 1, 24 hrs., then disappeared after 48 hrs., and there were no signs of erythema or oedema in all animals after 72 hrs. pii calculation of mastic orabase was 0.00, while in placebo group was the pii was 0.125, as showed in table (1). table 1: primary skin irritation test of six rabbits observed at 1, 24, 48, and 72 hrs. for erythema: 0 = no erythema, 1 = very slight erythema (barely perceptible), 2 = well-defined erythema, 3 = moderate to severe erythema, 4 = severe erythema (beet redness) to slight eschar formations (injuries in depth). for edema: 0 = no edema, 1 = very slight edema (barely perceptible), 2 = slight edema (edges of area well defined by definite raising), 3 = moderate edema (raised approximately 1 millimeter), 4 = severe edema (raised more than 1 millimeter and extending beyond the area of exposure). evaluation of primary irritation index (pii): 0.00 no irritation, 0.04 – 0.99 irritation barely perceptible, 1.00 – 1.99 a n i m a l # mastic orabase placebo erythema oedema erythema oedema observation periods (hr.) observation periods (hr.) observation periods (hr.) observation periods (hr.) 1 24 48 72 1 24 48 72 1 24 48 72 1 24 48 72 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 t o t a l 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 p i i 0.00 0.00 0.125 0.00 j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 48 slight irritation, 2.00– 2.99 mild irritation, 3.00 – 5.99 moderate irritation, 6.00 – 8.00 severe irritation. effects of mastic orabase on induced ulcer all rabbits developed erythematous surface and ulceration of 1.5-3.5 mm after 24 hrs. of ulcer induction. there was no differences between the two tested methods used for ulcer induction, after 2 days treatment with mastic orates, there was a significant declined ulcer size and healing in animals of ulcer size range (1.5-2.5 mm), p=0.01. the other animals showed healed ulcers after 3 days of treatment by mastic orabase with ulcer size range (2.6-3.5 mm), p=0.02. placebo groups showed redness, ulceration along the treatment period (5 days), p=0.6, as showed in figure (1).there was a dose-dependent efficacy of the treatment by three doses of mastic orabase. fig.1: ulcer area of rabbits’ cheek pouches of mastic orabase treated compared to placebo group, level of significance p< 0.05. microscopical histopathology study histopathology examination of the rabbit’s cheek pouch showed no inflammatory cells infiltration and there was re-epithelization, and healing evidence were seen with mastic orabase treated group, while placebo group showed heavy infiltration of acute and chronic inflammatory cells, and fibrous tissues with no evidence of reepithelization. safety/ toxicity rabbits of both sexes showed no signs of toxicity or death during the study& monitoring period (15 days). ld50 of mastic was 39±2 ml/kg oral, and 2.9±0.8 i.p., the therapeutic index was 10.9, and safety factor was 0.11 oral. therapeutic dose: 2 g/ day, toxic dose: 100 mg/kg, and oral toxic dose: 5 g/ kg. clinical study sixty five subjects enrolled were randomized to mastic orabase treatment groups i [35 (53.85%)]; a 5%, b10%, c 15%, or placebo group ii [30 (46.15 %)]. 41 females (63.08%), and 24 males (36.92%) were participated in this study, mean age was 32, and mean weight was 73 kg, all enrolled subjects have a minor aphthous ulcer type, table (2) clarified the subjects’ characteristics. table 2: subjects’ characteristics no. of subjects 65 gender ratio [female: male] 41 (63.08%): 24 (36.92%) mean age (year) 32 mean weight (kg) 73 family history ratio {+ve: -ve} 20 (30.77%): 45 (69.23%) mastic orabase treated group 35 (53.85 %) placebo group 30 (46.15 %) all subjects have inflammation and minor aphthous ulceration of 2-3 mm size at baseline, 52.3% (n: 34) of enrolled subjects have 2 mm ulcer size, showed a significant reduction of inflammation and ulcer size, and complete healing within 2 days of treatment (p=0.02), other subjects 47.7% (n: 31) have 3 mm ulcer size, showed a significant reduction of inflammation and ulcer size, and complete healing within 3 days of treatment by mastic orabase (p=0.01). there was no significant difference of inflammation, ulcer size after five days of treatment by placebo compared to baseline (p=0.7), as elucidated in figure (2, 3). fig. 2: ulcer area size (mm2) with days of trial of mastic orabase and placebo groups. fig. 3: level of inflammation and ulceration at baseline and after 3 days of treatment in both groups. the time needed for diminished the signs of inflammation and healing of ulceration were 0" 2" 4" 6" 8" 10" 1" 2" 3" 4" 5" u lc e r& a re a &s iz e &( m m 2 )& masc"orabase" placebo" inflamma&on( ulcera&on(0( 1( 2( 3( 4( mas&c( orabase( placebo( mas&c( orabas( placebo( le ve l%o f% in fl a m m ao n %& %u lc er ao n % baseline%%%%%%%%%%%%%%%%%%%%%%%%%%%%%a5er%3%days%of%treatment% j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 49 faster in mastic orabase treated group than placebo group, as follows: erythema; mastic orabase 2±0.5, placebo 9±1.5, oedema; mastic orabase 1±0.5, placebo 8±1.8, ulcer healing; mastic orabase 2±0.6, placebo 11±0.7. pain; mastic orabase 1±0.0, placebo 7±1.5. the efficacy indices (ei) of the ulcer size improvement were 90.8 for mastic orabase treated group, for placebo group ei was 8.2, as elucidated in table (3). pain was relieved from the first dose in all subjects treated by mastic orates in a significant value (p= 0.02) compared to non-relieved pain in placebo group, as showed in figure (4). table 3: effectiveness index in ulcer size reduction grading mastic orabase placebo p value heal 29 0 marked improvement 6 0 moderate improvement 0 1 no improvement 0 16 % improvement 100 5.8 0.001 efficacy index 90.8 8.25 0.0001 fig. 4: the peak intensity of pain reduction with the dosage of mastic orabase and placebo groups. {(0= baseline severe pain, 2= moderate, 4= mild, 6= minimal, 8= no pain), dose no. was 5 minutes between each}. saliva substance p level of rau subjects saliva substance p level was significantly high in both groups at baseline, after 4 days of treatment by mastic orabase showed highly significant reduction, and more reduction after 7 days compared to baseline (p=0.002), while placebo group showed no changes after 4 days of treatment and after 7 days (p=0.6), as clarified in figure (5). fig. 5: saliva substance p values at baseline, 4 days after treatment, and after 7 days for mastic orabase and placebo treated groups. saliva tgf_beta level of rau subjects saliva tgf-beta level was low at baseline in mastic orabase, and placebo groups; 139.9±20.8 and 139.8±23.4pg/ml, respectively. after 4 days of treatment, the level increased significantly in mastic orabase treated group (168.9±22.3pg/ml) compared to baseline (p=0.01), then the tgf-β level increased significantly to 180±40.7pg/ml (p=0.02) after 7 days, but placebo group showed no statistical differences after 4 days of treatment, and after 7 days (p=0.8), as showed in figure (6). fig. 6: mean saliva tgf-beta values for mastic orabase treated and placebo groups at baseline, 4 days after treatment, and after 7 days. adverse effects or reaction there was no adverse effect or reaction noticed during the study period (5 days) and monitoring period (3 weeks) after treatment. no sensitivity or allergy to treatment components was recorded from the usage of mastic orabase. discussion many studies focused on the causes or factors that lead to rau, and how is driven by unnatural cytokine responses associated with cellular immunity in oral mucosa. the aim of this study was to study the efficacy of mastic orabase for the first time on the healing process of induced ulcers on animals, and clinically on subjects suffered from rau. also for assessment of the levels of salivary cytokine such as substance p, and growth factor such as tgf-beta for the first time. mastic oil from pistacia lentiscus l. p e a k% in te n si ty %o f% p ai n %r e d u c2 o n % dosage% 0 50 100 150 200 250 baseline after 4 days of treatmentafter 7 days s u b st a n c e p p g /m l le v e l mastic orabase placebo 0 50 100 150 200 baseline after 4 days of treatment after 7 days m e a n s a li v a t g f -b l e v e l (p g /m l) mastic orabase placebo j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 50 (anacardiaceae) has been extensively studied for its anti-inflammatory activity attributed to the combination of its bioactive components. it has been widely used since ancient times without any reported toxicity in humans (18). this study agrees with that. analysis of the chemical composition of mastic oil revealed that is a complex mixture of volatile compounds, mainly terpenes, with established beneficial biological properties (15). the monoterpene perillyl alcohol (poh), which corresponds to 0.84% of mastic oil, is of great clinical interest due to its established chemopreventive and chemotherapeutic potential (19,20). poh, besides its antitumor effect, acts as an angiogenesis inhibitor (21). mastic oil has a widerange of therapeutic effects: anti-inflammatory, antibacterial, antifungal, antiviral, anticancer, and hypolipidemic activities (22,23). pistacia lentiscus is also effective in the treatment of functional dyspepsia and gastric ulcer (24), as well as in the healing of burns (14). anti-inflammatory properties have been reported from masticadienolic acid, masticadienonic acid, and morolic acid (25). the dermal irritation test of mastic orabase was performed in this study to ensure the safety usage in humans, the topical application of mastic orabase caused no signs of irritation, neither erythema nor oedema at the intact site, it can be categorized as a non-irritant drug. mastic orabase is safe and did not exhibit any toxicity during toxicity assessment by ld50, therapeutic index and safety factor on animals, which confirm the safety of mastic orabase, and agrees with studies, which mentioned that mastic agent without substantial side effects in humans and animals (26, 27). the induced ulcers on animals (by two different methods) were clinically indistinguishable from the spontaneous ulcers of patients, except that the induced lesions were generally smaller and healed more quickly. this study agreed with the previous study (28). topical application of mastic orabase showed a significant dose-dependent reduction of the induced ulcer size on animals, which healed between 2-3 days after treatment compared to non-effect by placebo. mastic orabase has the ability to heal and may protect the induced ulcers, the mechanism that explains this healing activity of mastic orabase can be explained by creating a protective layer on the ulcers and enhancing reepithelialization and healing of ulcers. histopathology of the cheek pouch elucidated that there was no inflammation, re-epithelialization, and healing evidence in mastic orabase treated group compared to placebo group, this can be explained by the anti-inflammatory activity of mastic orabase, which help re-epithelialization, and healing of induced ulcer. clinical effects of mastic orabase on the inflammation and ulceration in patients suffering from rau, showed a significant reduction of inflammation, decline ulcer size, and healing of ulcers within 2-3 days of treatment compared to baseline and placebo. the efficacy indices of the ulcer size improvement were higher significantly in mastic orabase group than placebo group. healing of ulcer was significantly enhanced by the topical application of mastic orabase, so it is considered as an active healing agent. there is increasing evidence that neuropeptides derived from sensory nerves are important mediators of inflammation in various tissues including the skin. substance p (sp) has been demonstrated to have a broad range of proinflammatory effects in vitro and in vivo by the activation of the nk1r on various immune and non-immune cell types (29,30). it is a neuropeptide, acting as a neurotransmitter & as a neuromodulator. sp amplifies or excites most cellular processes (32,33). it is a potent vasodilator, and induced vasodilatation is dependent on nitric oxide release (34). substance p released as a response to certain types of infection or injury (35), and initiates expression of almost all known immunological chemical messengers (cytokines) (36-38), most of the cytokines, can induce sp and the nk1 receptor (39,40), which is particularly excitatory to cell growth and multiplication (8). treatment by topical mastic orabase in this study showed a highly significant reduction of inflammatory mediator substance p compared to baseline and no effect in placebo group, this confirm the anti-inflammatory activity of mastic orabase. release of substance p is induced by stressful stimuli, and the magnitude of its release is proportional to the intensity and frequency of stimulation (6), and it was shown that substance p could promote wound healing of non-healing ulcers in humans (7), and its induced cytokines promote multiplication of cells required for repair or replacement, growth of new blood vessels (41).ulcer healing in mastic orabase group was faster and complete than that of placebo group, which may explain by the effect on inflammatory mediator substance p. from preclinical data, substance p is an important element in pain perception; the sensory function of substance p is thought to be related to the transmission of pain information into the central nervous system, which coexists with the excitatory neurotransmitter glutamate in primary j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 51 afferents that respond to painful stimulation (42). however, if substance p/neurokinin antagonist should have therapeutically useful analgesic activity, substance p release is a primary event, the resultant analgesia correlates to the occupancy of the neurokinin receptor by antagonist. in this study, the pain was relieved significantly from the first topical application of mastic orabase, while placebo no effect on pain, the peak intensity of pain reduction was confirmed by mastic orabase. this may be related to the topical protective coverage of ulcer, and the effects on substance p. cytokines are important factors that may induce and determine the type of the immune response in the human body (43), strong antiinflammatory effect is contributed to another cytokine called transforming growth factor (tgf)-beta, secreted mainly by the t-regulator lymphocytes (44,45). it was found that aphthous ulcer develops in response to the enhanced immunologic reaction against particular regions of the oral mucosa, this reaction occurs as a result of initiated cascade of cytokines that activate certain immune processes (2, 45, 46). patients with rau, the immune system’s function becomes disrupted in response to some kind of trigger factor, which may include viral and bacterial antigens or stress, and auto immunization (47, 48). the secretion of anti-inflammatory cytokines tgf-β was significantly decreased in ras patients compared to the healthy controls (49-51). this study revealed that mean salivary tgf-β level was significantly decreased in rau patients at baseline in both groups, which agrees with the above study, then a significant elevation of tgf-β level was seen after topical treatment by mastic orabase in rau patients, compared to the baseline and no effect on placebo group. mastic can affect the function of activated macrophages, inhibited the production of proinflammatory substances such as nitric oxide (no) and prostaglandin (pge2) by lipopolysaccharide (lps)-activated mouse macrophage-like cells. western blot and (rtpcr) analyses showed that mastic inhibited the expression of inducible no synthase (inos) and cox-2 at both the mrna and protein level (52-54). the anti-inflammatory activity of mastic orabase explains its effects on inflammation, and ulcer healing. these activities explain the mechanism of action of mastic orabase in the treatment of aphthous ulceration. other mechanism of mastic orabase action that may explain its ability to enhance ulcer healing is an immunity enhancer. further studies should evaluate the pharmacokinetic effects of mastic orabase and the recurrence of rau. references 1scully c, gorsky m, lozada-nur f. the diagnosis and management of recurrent aphthous stomatitis. a consensus approach. jada 2003; 134: 200-7. 2eversole lr. immunopathology of oral mucosal ulcerative, desquamative, and bullous 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j oral pathol med 2012; 41:158– 64. 49lewkowicz n, lewkowicz p, banasik m, kurnatowska a, tchórzewski h. predominance of type 1 cytokines and decreased number of cd4+ cd25+ high t regulatory cells in peripheral blood of patients with recurrent aphthous ulcerations. immunol j bagh college dentistry vol. 29(3), september 2017 treatment of recurrent oral diagnosis 53 lett 2005; 99 (1): 57-62. 50albanidou-farmaki e, markopoulos ak, kalogerakou f, antoniades dz. detection, enumeration and characterization of t helper cells secreting type 1 and type 2 cytokines in patients with recurrent aphthous stomatitis. tohoku j exper med 2007; 212 (2): 101-5. 51seifi s, maliji gh, azadmehr a, motallebnejad m, maliji e, khosravi samani m, farokhi r, babaei khameneh h. salivary vegf-r3, tnf-α, tgf-β and il-17a/f levels in patients with minor aphthous. res mol med 2015; 3 (4): 30-5. 52zhou l, satoh k, takahashi k, watanabe s, nakamura w, maki j, hatano h, takekawa f, shimada c, sakagami h. reevaluation of antiinflammatory activity of mastic using activated macrophages. in vivo 2009; 23: 583-9. 53mahmoudi m, ebrahimzadeh ma, nabavi sf, hafezi s, nabavi sm, eslami sh: anti-inflammatory and antioxidant activities of gum mastic. eur rev med pharmacol sci 2010; 14: 765-976. 54triantafyllou a, bikineyeva a, dikalova a, nazarewicz r, lerakis s, dikalov s. antiinflammatory activity of chios mastic gum is associated with inhibition of tnf-alpha induced oxidative stress. nutr j 2011; 10: 64. الخالصة (tgf-β) لديها نشاط في االستجابة االلتهابية. تحويل عامل النمو بيتا p للفم. المادةخلفية: القرحة القالعية المتكررة هي مرض التهابي مزمن في الغشاء المخاطي بطمية لديه أنشطة هو وجهري المناعي ينظم االستجابة المناعية وله خصائص مضادة لاللتهابات، واآلثار الموالية لاللتهابات. بطم عدسي )المصطكي( من عائلة ومضادات األكسدة، ويستخدم في عالج وإصالح الجروح . الهدف من هذه الدراسة للعثور على سالمة وفعالية المستحضر دوائية مثل المضادة لاللتهابات، .الموضعي الدوائي الجديد المصطكي؛ تجريبيا وسريريا رن،، فعالية المصطكي على القرح طرق العمل: درس هذا البحث قسمين: أوال، تجريبيا لتقييم فعالية المستحضر الموضعي المصطكي على تهيج الجلد لال تحضر الموضعي المستحدثة، مع دراسة التغيرات في أنسجة األران،، وسالمة المستحضر: المؤشر العالجي وعامل األمان. ثانيا؛ الفعالية السريرية من المس اللتهاب، وتقليل وقت التآم القرحة، و تقليل األلم، قياس مستويات المصطكي على الشفاء من القرحة القالعية المتكررة عن طريق تقييم للحد من حجم القرحة، وقلة ا .ارةوعامل النمو التحويلي بيتا في لعاب المرضى الذين يعانون القرحة القالعية المتكررة ، ورصد أي آثار سلبية أو التفاعالت الدوائية الض p المادة عي المصطكي، انخفاض كبير في التهاب و حجم القرحة، وتضميد الجراح بوقت قصير: وأكد سالمة النتائج: أظهرت الدراسة التجريبية الستخدام العالج الموض تضميد الجراح في مستحضر المصطكي بعدم تهيج الجلد، ال سمية، ومستوى واسع للمؤشر العالجي. أظهرت نتائج الدراسة السريرية الحد من االلتهاب والتقرح، و ة موضعية، والتأكد من وصول النشاط المضادة لاللتهابات من استعمال المستحضر الموضعي المصطكي بتخفيض مستوى وقت قصير،الغي االلم من اول جرع .في اللعاب tgf-β وارتفاع مستوى p المادة ذلك متعلقا بتأثير المصطكي اإلستنتاج: أظهر مستحضر المصطكي الموضعي فعالية تعتمد الجرعة في عالج التقرح القالعي المتكرر، قصر وقت الشفاء. قد يكون .بيتا tgfو p على العوامل الوسيطة التي تعمل قبل االلتهاب والمضادة لاللتهابات. المادة firas f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of transverse 1 restorative dentistry evaluation of transverse and tensile bond strength of repaired nylon denture base material by heat, cold and visible light cure acrylic resin firas a.f., b.d.s., m.sc. (1) ghazwan a.a., b.d.s., m.sc. (1) ali a.m., b.d.s., m.sc. (1) abstract background: denture fracture is one of the most common problems encountered by the patients and prosthodontists. the objective of present study was to evaluate the transverse strength of nylon denture base resin repaired by using conventional heat polymerized, autopolymerized and visible light cure {vlc} resins, surface treatment that used for repair and adjustment of insufficient nylon denture bases and in case of addition of artificial teeth. as these corrective procedures are common chair side procedures in dental clinic. materials and methods: one hundred twenty nylon specimens were prepared by using metal patterns with dimension of (65x10x2.5 mm) length, width, and thickness respectively for transverse strength test while for tensile bond strength a dumbbell-shaped with measurement (65x12.5x25mm) length, width, and thickness respectively were flasked with stone. the nylon specimens were molded by reflasked with dental stone that used as an index for these specimens in the repair procedure and repaired with 45 degree bevel joint by using metal holding device. the two parts of nylon specimen to be repaired were realigned in its repair index and adhere with special adhesive material to stabilize the combination during repair procedure. the dough of heat and cold cure resin was packed into the joint and then cured. the specimen repaired with cold cure resin was placed in the ivomat containing water at (40°c) and pressure (30ib/inch²) for 15 minutes. the specimen repaired with {vlc} was placed in the light cure unit for 4 minutes following manufacturer’s instruction. the fractured nylon specimens were divided according to the type of repaired materials into (40) specimens received heat cure acrylic and the (40) specimens received cold cure acrylic and the other 40 specimens received {vlcr}. each 40 specimens were subdivided according to the type of surface treatment received into 20 specimens were treated with coarse stone bur (control), 20 specimens were treated with combination of coarse stone bur and monomer of the heat cure acrylic. after that the specimens were subjected to transverse {tr} and tensile bond {tb} strength tests. for each test 10 specimens. results and conclusions: this study showed that specimens treated with combination of coarse stone bur and monomer of the acrylic (heat, cold or vl cure) had the highest transverse and tensile strength values, followed by the specimens treated with coarse stone bur. the results showed that the specimens repaired with heat cure acrylic had transverse and tensile strength values higher than the specimens repaired with cold and vl cure acrylic when compared between subgroups of heat, cold and vl cure acrylic that received the same treatments. key words: transverse and tensile stress, denture repair. (j bagh coll dentistry 2013; 25(special issue 1):1-5). inroduction in recent years, nylon polymer has been attracting attention as a denture base material because of a host of advantages: favorable esthetic outcome, toxological safety to patients allergic to conventional metals and resin monomers, higher flexibility which than conventional heatpolymerizing resin facilitate denture retention by utilizing the undercuts of abutment teeth in the denture base design. this meant that metal clasps can be eliminated from denture bases, which also meant that problems resulting from metal clasps such as excessive stress on abutment teeth, esthetic compromise can be reduced. in this study, a nylon denture base polymer was subjected to surface treatment with a coarse stone bur to form a rough surface to assess the effect of this surface treatment on the transverse strength of nylon repaired with different types of acrylic resins the final strength of an acrylic resin repair relies on the type of repair material used. (1)assistant lecturer. department of prosthodontics. college of dentistry, university of baghdad. transverse strength of a conventional heatcured repair is about 80% of that of the intact material, while repairs conducted with a chemically activated resin can reach 60% of the strength of the original denture base material. when choosing a repair technique, other factors besides strength must be considered, such as the working time demanded and the degree to which dimensional accuracy is maintained during repair (1,2). the objective of present study was to evaluate the transverse strength of nylon denture base resin repaired by using conventional heat polymerized, autopolymerized and visible light cure {vlc} resins, surface treatment that used for repair and adjustment of insufficient nylon denture bases and in case of addition of artificial teeth. materials and methods a metal pattern were prepared with measurement (65x10x2.5mm) length, width, and thickness respectively used for produced sixty nylon specimens for transverse strength test while j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of transverse 2 restorative dentistry for tensile bond strength test a dumbbell-shaped metal pattern of (65x12.5x2.5) length, width, thickness respectively was constructed to produced sixty nylon specimens for that test according to ada no.12, 1999. the metal pattern was flasked with metal flask by using dental stone (geastone, zeus sriloc. tamburine roccastrada, gr, italy). the metal patterns were coated with a separating medium and a sprue wax gauge 5 mm was attached to the middle of the metal mold and allowed to dry after investing them in the lower half of the flask which contain mixed stone according to the manufacturer instruction (100 g/31ml) ;(p/w) and allowed to set. the set lower half was coated with separating medium and then the upper half of flask was assembled and filled with stone mixture and the sprue wax should appear to be easily recognized during injection process. after wax elimination procedure the metal patterns were removed and the two halves of the flask were coated with a separating medium to be ready for injection with nylon denture base (valplast international corporation, usa) (2-4). one hundred twenty (120) nylon specimens were prepared and divided according to the type of acrylic resin received each type 40 specimens, for heat {h} and for cold {c} cure acrylic resin, and for visible light cure resin {vl}, the specimens were subdivided according to the type of surface treatment received into (20) specimens for coarse stone bur surface treatment (control) for heat cure {h1}, for cold cure {c1}, for light cure {vl1} and (20) specimens for combination of coarse bur and heat cure monomer (experimental) for heat cure {h2}, for cold cure {c2}, for light cure {vl2} as shown in diagram below. diagram showed groups distribution preparation of the repaired nylon specimens fracturing and joint preparation the nylon specimens were molded with stone mix with metal flask to make an index after fracture procedure. the nylon specimens were repaired with 45 degree bevel joint by using metal holding device having a central recess figure (1). the dimension of the central recess of the holding device was (31mm length x12.5 mm width from posterior end of the recess x 2.5 mm thickness. the nylon specimen was placed in the central groove and cut with a fissure bur near the bevel end. the cut end was prepared with course stone bur. the same procedure was done for the other half. by this method the gap space between these two halves was (3mm) with 45 flaring downward (5,16). figure 1: holding device with 45° bevel joint repair by the heat cure acrylic resin the nylon specimens were placed on the stone mold that had been done previously for repairing procedure and divided according type of repaired material. for heat cure acrylic resin, the two parts of nylon specimen to be repaired were realigned in its repair index and adhere with special adhesive material to stabilize the combination during repair procedure. after painting it with separating medium, and the repaired specimen was treated according to the classification of surface treatment received, for the combination surface treatment the monomer was applied by painting over the nylon specimen 10 seconds before the dough heat cure resin packed into the fracture joint area, pressed and then cured (3,6). repair by the cold cure acrylic resin the two parts of nylon specimen to be repaired were realigned in its repair index and adhere with special adhesive material to stabilize the two parts during repair procedure. after painting it with separating medium, and with monomer for combination surface treatment the cold cure resin dough was adapted well into the repair joint area and then placed in the ivomat containing water at (40°c) and at pressure (30ib/inch²) was applied for 15 minutes. all repaired specimens were stored in distilled water and incubated at 37°c for 48 hours (7,10). j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of transverse 3 restorative dentistry figure 2: a fracture nylon specimen placed in the stone mold with 3mm gap for repair material application preparation of the vlcr the nylon specimens were fixed on a flat glass plate, then a layer of separating medium was applied on the nylon specimen, then a stone mixture was prepared by mixing the correct water powder liquid ratio which was then poured onto the nylon specimen with vibration to get rid of air bubbles, a second glass plate was placed over the stone mix which stopped by placing a layers of sheet wax (2.5mm thickness) at the two end of glass plate, so the nylon specimen and stone was sandwiched between the two glass plates with 2.5mm thickness of stone. repair by vlcr the same procedure in the repair of nylon specimen with heat and cold cure resin was followed, after application of separating medium, and monomer for combination surface treatment, the light cure sheet was cut into small piece and adapted well on repair joint area. the material adapted well using glass plate weight, access material was removed by using sharp knife and then cured with light curing unit for 4 minutes (following manufacture´s instruction). testing procedure transverse strength test {tr} the specimens were measured by three points bending on instron universal testing machine. the load was measured by compression load cell with scale of 100 kg the specimens were deflected until fracture occurred. the values of transverse strength were computed by the following equation: s = 3pi/2bd in which s: transverse strength (n/mm²) or (mpa) p: peak load exerted on specimen (n) i: distance between supporting rollers (mm) b: width of the specimen (mm) d: depth of the specimen (mm) (2,8). tensile bond strength test {tb} the test of specimens were measured by instron universal testing machine with grips suitable for the test specimens, at cross head speed of 0.5 mm/min and the chart speed was 20 mm/min. a tensile load cell measured with a scale of 100kgthe recorded at failure was measured. results the mean values of transverse strength and tensile bond strength were classified according to the type of acrylic and subdivided according to the type of surface treatments received for heat cure acrylic h, for cold cure c and for light cure vl. discussion in general the results of the transverse strength (tr) and tensile bond (tb) of repaired specimens with heat, cold or light cure acrylic showed that application of monomer to the nylon specimen has the highest mean value while the strength decreased in the specimens without monomer application; table (1,7). the effect of monomer was present clear when compare between the specimens that not treated with monomer for both tr and tb strength tests as shown in table (2, 8). (9,10) the effect in regard to the type of material of repair: all the flexible specimens that repaired with heat cure acrylic with combination surface treatment (monomer and coarse stone bur) or without monomer showed highly significant difference for both tr and tb strength than specimens repaired with cold and light cure acrylic table (3,4,9,10). this may be due to the higher degree of temperature reached during polymerization of heat cure acrylic resin than other types so more softening of surface layer of flexible specimens and more penetration of repaired material into surface layer (11-13). the effect of tr and tb tests in regard to the type of surface treatment applied the repaired flexible specimens treated with monomer (for heat cure or for cold or vl cure groups) had higher tr and tb strength mean values, with highly significant differences, this may attributed to the fact that the repaired surface was well dissolved with monomer and this lead to the formation of micropores which act as mechanical retention, thus enhanced bonding of the repaired resin to the treated flexible resin surface (14-16). due to the metylmethacrylate act as a reactive solvent with nylon specimen make interlocking bond with repaired material especially heat cure lead to increase the functional sites which produce a stronger tr and tb strength at which act as chemical retention that shown in tables (5,6,11,12). the specimens repaired with heat and cold cure showed higher tr and tb strength than that j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of transverse 4 restorative dentistry with vl cure, this result due to higher viscosity exhibited by the vl cure which makes the diffusion of the repair material to the original material less than that shown with other types as showed in table (1, 7) (2,17). furthermore, the vl cure had poor wettability due to less monomer contain than other types which lack makes interlocking bond with the repaired specimen. (18,19). table 1: descriptive data of transverse strength of the specimens repaired by heat h, cold c, and light vl cure acrylic repaired material surface treatments statistical analysis mean sd heat cure h1 124 2.748 h2 95 1.813 cold cure c1 80 1.490 c2 55.1 1.449 vlc vl1 45.2 1.316 vl2 27 1.024 table 2: t-test between with and without monomer subgroups specimens of transverse strength test for heat {h}, cold {c} and light {vl} subgroups t-test p-value significant h1 & h2 27.004 p<0.01 hs c1 & c2 38.88 p<0.01 hs vl1 & vl2 27.31 p<0.01 hs table 3: t-test of transverse strength between with monomer subgroups specimens of h, c, and vl groups t-test p-value significant h & c 59.03 p<0.01 hs h & vl 74.91 p<0.01 hs c &vl 47.85 p<0.01 hs table 4: t-test of transverse strength between without monomer subgroups specimens of h, c, and vl groups t-test p-value significant h & c 74.33 p<0.01 hs h & vl 88.86 p<0.01 hs c &vl 45.91 p<0.01 hs table 5: anova of transverse strength test of specimens repaired with monomer h, c, and vl groups f-test p-value significant h&c&vl 406.41 p<0.01 hs table 6: anova of transverse strength test of specimens repaired without monomer h, c, and vl groups f-test p-value significant h&c&vl 35.116 p<0.01 hs table 7: descriptive data of tensile bond strength of the specimens repaired by heat h, cold c, and light vl cure acrylic repaired material surface treatments statistical analysis mean sd heat cure h1 103.6 2.674 h2 74.2 1.813 cold cure c1 59.8 1.619 c2 34.8 1.032 vlc vl1 24.3 1.337 vl2 8.5 1.080 table 8: t-test between with and without monomer subgroups specimens of tensile bond strength test for heat {h}, cold {c} and light {vl} subgroups t-test p-value significant h1 & h2 28.11 p<0.01 hs c1 & c2 50.56 p<0.01 hs vl1 & vl2 24.44 p<0.01 hs table 9: t-test of tensile bond strength between with monomer subgroups specimens of h, c, and vl groups t-test p-value significant h & c 51.31 p<0.01 hs h & vl 74.45 p<0.01 hs c &vl 51.66 p<0.01 hs table 10: t-test of tensile bond strength between without monomer subgroups specimens of h, c, and vl groups t-test p-value significant h & c 61.95 p<0.01 hs h & vl 110.1 p<0.01 hs c &vl 48.83 p<0.01 hs table 11: anova of tensile bond strength test of specimens repaired with monomer h, c, and vl groups f-test p-value significant h&c&vl 409.24 p<0.01 hs table 12: anova of tensile bond strength test of specimens repaired with monomer h, c, and vl groups f-test p-value significant h&c&vl 409.24 p<0.01 hs j bagh college dentistry vol. 25(special issue 1), june 2013 evaluation of transverse 5 restorative dentistry references 1. harper ca. handbook of plastics, elastomers and composites. 4th ed. new york: mcgraw-hill; 2004. 2. abdul-hadi nf. the effect of fiber reinforcement and surface treatment on some of the mechanical properties of the repaired acrylic denture base materials (a comparative study). a master thesis, prosthetic, university of baghdad, 2007. 3. al-nadawi lm. the effect of different surface treatment and joints surface shapes on some mechanical properties of the repaired acrylic denture base resin cured by two different techniques. a master thesis. university of technology, 2005. 4. shamnur sn, jagadeesh kn, kalavathi sd, kashinath kr. flexible dentures – an alternate for rigid dentures. j dent sciences and research 2010; 1:74-79. 5. naveen bh, patil sb, kumaraswamy k. a study on transverse strength of different denture base resins repaired by various materials and methods: an in-vitro study. j dent sciences and research 2010; 1: 66-73. 6. parvizi a, lindguist t, schneider r, williamson d, boyer d, dawson dv. comparison of the dimensional accuracy of injection-molded denture base materials to that of conventional pressure-pack acrylic resin. j prosthodontics 2004; 13(2):83-9. 7. rached rn, powers jm, del bel cury aa. efficacy of conventional and experimental techniques for denture repair. j oral rehabil 2004; 31: 1130–1138. (ivsl). 8. abuzar ma, bellur s, duong n, kim bb, lu p, palfreyman n, surendran d, tran vt. evaluating surface roughness of a polyamide denture base material in comparison with poly (methyl methacrylate). j oral science 2010; 52: 577-581. 9. yunus n, rashid aa, azmi ll, abu-hassan mi. some flexural properties of a nylon denture base polymer. j oral rehabil 2005; 32: 65-71. 10. rizgar ma. the effect of addition of radio opaque materials on some mechanical and physical properties of flexible denture. a ph.d. thesis, department of prosthodontics, college of dentistry, university of baghdad, 2011. 11. dhiman rk, chowdhury sk. midline fracture in single maxillary complete acrylic vs. flexible denture. m jafi j 2009; 65:141-5. 12. abuzar am, bellur s, duong n, kim bb, lu, palfreyman n, surendran d, tran tv. evaluating surface roughness of a polyamide denture base material in comparison with poly (methyl methacrylate). j oral sci 2010; 52(4): 577-81. 13. aljudy hj, hussein an, safi in. effect of surface treatments and thermocycling on shear bond strength of various artificial teeth with different denture base materials. j bagh coll dentistry 2013; 25(1): 5-13. 14. anusavice kj. phillip's science of dental materials. 10th ed. philadelphia: w.b, saunders co; 2008. p. 211, 220, 235, 237-271. 15. meng gk, chung kh, fletcher-stark ml, zhang h. effect of surface treatments and cyclic loading on the bond strength of acrylic resin denture teeth with autopolymerized repair acrylic resin. j prosthetic dent 2010; 103(4): 245-52. (ivsl). 16. cunningham jl. shear bond strength of resin teeth to heat cured and light cured denture base resin. j oral rehabil 2000; 27: 31216 (ivsl). 17. abdulsahib aj. evaluation of the tensile bond strengths of heat cure acrylic and valplast with silicone self-cure soft liner a master thesis, department of prosthodontics, college of dentistry, university of baghdad, 2011. 18. mohammed ali b. preparation and evaluation of some properties of heat-cured, acrylic-based soft denture liner. a ph.d. thesis, department of prosthodontics, college of dentistry, university of baghdad, 2006. 19. kawara m, carter jm, ogle re, johnson rr. bonding of plastic teeth to denture base resins. j prosthet dent 1991; 66:566–71. cited by: marra j, paleari ag, pero a, de souza rf, barbosa db, compagnoni ma. effect of methyl methacrylate monomer on bond strength of denture base resin to acrylic teeth. int j adhesion adhesives 2009; 29:3915. j bagh college dentistry vol. 28(4), december 2016 the effect of restorative dentistry 22 the effect of silver-zinc zeolite incorporation on some properties of condensation silicone impression material rehab a. al-azawi, b.d.s., h.d.d. (a) widad a. al-naqash, b.d.s., h.d.d., m.sc. (b) abstract background: elastomeric impression materials are indicated when a high degree of accuracy is required, due to their excellent properties like details reproduction, dimensional stability and tear strength but with main two disadvantages those are their hydrophilicity as well as the absence of antibacterial activity. this study aimed to evaluate the effect of incorporation of 0.5% wt ag-zn zeolite into condensation silicone through the following tests; setting time, dimensional stability, reproduction of details, wettability, and hardness . materials and methods: one hundred specimens were constructed of condensation silicone, divided into two groups for the first 50 specimens one0.5% by wt ag -zn zeolite was added, keeping the other fifty specimens without addition. then each group further subdivided into five subgroups according to the conducted test. the tests performed were; setting time, dimensional stability, reproduction of details, hardness and wettability. results: a statistically non-significant effect on the setting time and reproduction of details tests was observed, combined with a highly significant increase of wettability of condensation silicone after incorporation of 0.5% wt agzn zeolite with non-significant increase of dimensional change of condensation silicone following incorporation of 0.5% wt ag-zn zeolite. hardness test results shoed statistically significant increase following the addition of ag-zn zeolite. conclusion: ag-zn zeolite incorporated into condensation silicone, improved wettability which determine the extent to which an impression material replicates the structures of the oral cavity and production of bubble-free gypsum die. it also showed a statistically significant increase in the hardness of condensation silicone impression material, and had no effect on setting time, reproduction of details and dimensional stability. key words: condensation silicone impression materials, antimicrobial agent, agzn zeolite, wettability. (j bagh coll dentistry 2016; 28(4):22-27) introduction elastomeric impression materials include a group of synthetically polymerized impression materials that are chemically cross-linked when set and could be stretched and recover to their original dimensions. there are three types based on the chemical backbone of polymer chains: polysulfide, polyether, and silicone; the condensation and addition (1). condensation silicone impression materials are widely used nowadays is supplied in a two consistencies light and putty-like. the curing of this material involves a reaction of triand tetrafunctional alkyl silicates in the presence of stannous octoate as a catalyst. the material sets by cross-linking between terminal groups of the silicone polymers and the alkyl silicate to form a three-dimensional network, the ethyl alcohol as a byproduct. its subsequent evaporation accounts for much of the contraction that takes place in the setting impression (1,2). nowadays infection control takes interest in order to prevent cross infection between the patients and dental staff. the threat of infections could be transferred by blood, saliva, and/or plaque is a potential occupational risk as they include pathogenic microorganisms (3). (a)m.sc. student. department of prosthodontics. college of dentistry, university of baghdad. (b)professor. department of prosthodontics. college of dentistry, university of baghdad. the incorporation of zeolite as filler in polymers was reported in literatures and proved that it enhanced the antibacterial activity of these polymers. silver ion exchanged zeolites have excellent antibacterial activity and therefore have a potential in the medical field to enhance antimicrobial properties.(4) the present study was conducted to assess the incorporation of ag-zn zeolite into condensation impression material and evaluate its effects on their properties materials and methods one hundred specimens of condensation silicone were prepared, divided into two groups; fifty specimens control (without addition) and fifty experimental specimens (with addition of 0.5% ag-zn zeolite) with fifty specimens, then each group was subdivided according to the test conducted; each subgroup containing ten specimens for each test. the percentage 0.5 % is chosen in this study as this percentage representing the minimum percentage as an effective bactericidal agent as proved by many authors (5,6). physical and mechanical tests: 1dimensional change test: the test block and ring mold were fabricated for this study (ada/ansi) specification no.19. consisted of two parts; a circular stainless steel j bagh college dentistry vol. 28(4), december 2016 the effect of restorative dentistry 23 block, and a hollow stainless steel ring was used to retain and confine the impression material. three vertical lines a 25 mm length and of 25 μm, 50 μm and 75 μm width were engraved on the metal surface of the stainless steel block (line a 50μm, line b 25 μm, and line c 75 μm).two additional horizontal lines 25 mm apart from each other were engraved perpendicular to the previously marked lines, each have 50 μm width, (line d1 and d2) as in (fig. 1) figure 1: the lines of the test mold: 1 line a (50 um thick.), 2 line b(25 um thick.), 3 line c (75 um thick.), 4 line d1(50 um thick), 5 line d2 (50 um thick).(7) 2-reproduction of details test the same mold used for dimensional change test (fig. 1) was again used for this test. following the separation and washing of the specimen an enter-estimation by three independent examiners was carried on to assess the reproduction of details by examining the continuity of the line b (25 µm) on the impression surface. where line b is the smallest in diameter among the die lines, so if it is clearly reproduced the other larger lines would be already reproduced (8-10). 3-setting time test vicat penetrometer has been used, with a needle of 3-mm diameter and a total weight of 300g. a metal ring of8 mm high and diameter of 16 mm was filled with newly mixed material and positioned on the penetrometer base. then needle was applied to the surface of the impression material for 10 sec. and a reading was recorded. this step was repeated every 30 sec. the initial set is that time when the needle no longer penetrates the specimen completely to the bottom of the specimen. while the final set is the first of three non-maximum identical penetration readings (2). 4-wettability test: wettability assessed by measuring the advancing contacting of liquid on the surface of the set impression material. specimens were poured in cylindrical metal mould a drop of distilled water falling down above a set specimen and after one minute measure the angle between the surface of the drop and the surface of specimen by dino-litemicroscope (11). 5hardness test: the specimens made for this test by using a cylindrical mold. then the hardness of condensation silicone impression material was tested by shore a hardness durometer instrument. this device was firmly grasped and insert it's indenter in the set specimen as shown in the (fig.2) the specimen was placed on a stable bench where the readings were recorded on the device screen. two readings were obtained, the first represented the hardness 1.5 minutes after setting, where the second reading was for the hardness after 2 hours.(12) four specific indentations were measured each time distributed it in a 90 ° manner at a location12 mm from any edge and at least 6 mm from any previous indent (the same selected area of each specimen), measurements followed astm d2240–05specification for shore a hardness measurements. the average of the four readings in order to measure the whole surface of the specimen (13). figure 2: hardness sample with the sites of penetration results 1dimensional change test: mean values, number of specimens, standard deviation, t-test, and p-values of dimensional change test for control and experimental groups of 1 2 3 25mm 4 5 j bagh college dentistry vol. 28(4), december 2016 the effect of restorative dentistry 24 condensation silicone are presented in table 1, table 2 and fig. 3. the results of dimensional test indicated nonsignificant difference between experimental and control groups which exhibited a mean values 0.877 and -0.917 respectively. table 1: descriptive data of dimensional change test for control and experimental groups group n mean% sd control 10 -0.917 0.47 experimental 10 -0.877 0.4 table 2: t-test and p-value for dimensional change test t-test p-value sig. -0.2 0.84 ns figure 3: bar chart of dimensional change for condensation silicone 2-reproduction of details the results of reproduction of details test are listed in table 3, showed the similarity in descriptive data for both groups; control and experimental. table 3: reproduction of details results for the control and experimental groups. group n satisfactory unsatisfactory control 10 100% 0% experimental 10 100% 0% 3wettability mean values, number of specimens, standard deviation, t-test, and p-values of wettability test, are presented in tables 4, 5 and fig4. the results indicated very clear and highly significant difference between means of the experimental (62.27) and control (72.84) groups. table 4: descriptive data of wettability test for control and experimental groups. group n mean° sd control 10 72.84 1.28 experimental 10 62.27 2.38 table 5: t-test and p-value for wettability test t-test p-value sig. 12.346 0.00 hs figure 4: bar chart for wettability test. 4-setting time test: mean values, number of specimens, standard deviation, t-test, and p-values of setting time test, are presented in table 6, table 7 and fig. 5. these results indicated a similar mean values for both groups; experimental and control, which is (216 seconds). table 6: descriptive data of setting time test for control and experimental groups group n mean(sec) sd control 10 216 12.64 experimental 10 216 12.64 table 7: t-test and p-value for setting time test t-test p-value sig. 0.00 1 ns figure 5: bar chart for setting time test. 0.85 0.86 0.87 0.88 0.89 0.9 0.91 0.92 cond_contr cond_exp dimensional_change 56 58 60 62 64 66 68 70 72 74 cond_contr cond_exp wettability 0 50 100 150 200 250 cond_contr cond_exp setting_time_seconds j bagh college dentistry vol. 28(4), december 2016 the effect of restorative dentistry 25 5-hardness test: a– after 1.5 minute: mean values, number of specimens, standard deviation, t-test, and p-values of hardness test at 1.5 minute, are presented in table 8,table 9 and fig. 6. figure 6: bar chart for hardness at 90 second their results indicated a non-significant difference between experimental and control means which are 16.62 and 16.14 respectively table 8: descriptive data of hardness test at 90 sec. for control and experimental groups. group n mean(°) sd control 10 16.14 1.58 experimental 10 16.62 0.94 table 9: t-test and p-value for hardness test at 90 sec. t-test p-value sig. -0.595 0.42 ns b-hardness test at 2 hour mean values, number of specimens, standard deviation, t-test, and p-values of hardness test at 1.5 minute, are presented in table 10, table 11 and fig. 7. the results indicated very clear and highly significant difference between means of the experimental and control groups, which are; 35.04 and 31.39 respectively. table 10: descriptive data of hardness test at 2hr. for control and experimental groups. group n mean(°) sd control 10 31.39 1.77 experimental 10 35.04 0.78 table 11: t-test and p-value for hardness test at 2hr. t-test p-value sig. -0.82 0.00 hs figure 7: bar chart for hardness at 2 hour disscusion zeolite was selected as a vehicle for antimicrobial cations because of its characteristics, including prolonged antimicrobial activity, non-toxicity and lack of odor or flavor (1416). zeolite type x was used in this study due to the fact that zeolite x has got an excellent ionic conductivity as well as superior hydrophilicity. as zeolite x has low si/al ratio where the cation concentration, ion exchange capacity and hydrophilicity are inversely proportional to that ratio (15-17) hydrophilicity is a beneficial attribute to prevent air bubbles formation within gypsum replica (18). sliver and zinc ion as the cations of choice to be used in this study because they proved to possess strong antibacterial and antifungal activity (19,20). the concentration of 0.5 % selected in this study was optimized as this percentage representing the minimum percentage as an effective bactericidal agent (5,6). the results of dimensional change test in this study shows that the incorporation of ag-zn zeolite into condensation silicone because a nonsignificant change in the dimensional change of condensation silicone, this could be due to that the zeolite slightly decreases the evaporation of ethanol as by product. another explanation is that it could be due to that the condensation silicone already contain silica in its basic ingredients in a percentage between (35-70%) so the added 0.5% by wt well probably has no sensible effects on condensation properties (12,21). concerned with reproduction of details test it was noticed that the experimental group of condensation silicone showed almost identical results with those of control group, as an explanation it could be due to the small particles of incorporated zeolite in a range of (0.5–1µm) which was in accordance with the requirements of ada/ansi specification no. 19 for elastomeric impression material (7,8,21). also it could be due to 15.8 16 16.2 16.4 16.6 16.8 cond_contr cond_exp hardness_90seconds 28 30 32 34 36 cond_contr cond_exp hardness_2hours j bagh college dentistry vol. 28(4), december 2016 the effect of restorative dentistry 26 the small percentage of ag-zn zeolite incorporated (22). another explanation is that may be due to an increase in the hydrophilicity of the impression material as a result of incorporation of zeolite. as the hydrophilicity increased the reproduction of details enhanced (1). the wettability test results showed a highly significant increase in wettability of the experimental groups for condensation silicone in comparison to its control group. this increase of wettability could be explained by hygroscopic property of zeolite (23-25). the setting time results experimental and control groups for condensation silicone had nearly the same mean values of setting time test which was statistically non-significant. this may be contributed to the fact that only small percentage as well as small particle size (in range of 0.5-1µm) of the ag-zn zeolite incorporated into experimental material (21,22,24). the results of hardness test showed that the hardness after 1.5 min. of setting exhibit a statistically non-significant increase but with highly significant increase after 2 hours of setting time. generally, zeolite incorporation may increase the hardness values of the material, and this increase in hardness was directly proportional to the increases in concentration of incorporated ag-zn zeolite (25). as an explanation that it could be attributed to the randomly distributed particles of a hard material into impression material matrix. other explanation; it could be due to that zeolite is mainly composed of silica with small particle size and high surface area leading to better interfacial adhesion of the test material (25). references 1. anusavice kj, shen c, rawls hr. phillips’ science of dental materials.12th ed. st. louis: saunders, elsevier inc.; 2013. pp.153. 2. craig rg, powers jm. restorative dental materials.12th ed. st. louis: elsevier; 2006. pp.291. 3. samra rk, bhide sv. efficacy of different disinfectant systems on alginate and addition siliconee impression materials of indian and international origin: a comparative evaluation. j indian prosthodont soc 2010; 10(3):182–9. 4. kamişoğlu k, aksoy ea, akata b, hasirci n, baç n. preparation and characterization of antibacterial zeolite–polyurethane composites. j appl polymer sci 2008; 110: 2854–61. 5. mutneja p, raghavendraswamy kn, gujjari ak. flexural strength of heat cure acrylic resin after incorporation of different percentage of sliver-zinc zeolite an in-vitro study. ijci 2012; 4(4): 25-31. 6. kawahara k, tsuruda k, morishita m, uchida m. antibacterial effect of silver-zeolite on oral bacteria under anaerobic condition. dent mater 2000; 16: 4525. 7. american national standardization institute / american dental association, specification no.19 for elastomeric impression material. 2004. chicago il: ansi/ada. 8. johnson gh, lepe x, aw tc. the effect of surface moisture on detail reproduction of elastomeric impressions. j prosthet dent 2003; 90: 354-64. 9. petrie cs, walker mp, o’mahony am, spencer p. dimensional accuracy and surface detail reproduction of two hydrophilicvinyl polysiloxane impression materials tested under dry, moist, and wet conditions. j prosthet dent 2003; 90: 365-72. 10. katyayan pa, kalavathy n, katyayan m. dimensional accuracy and detail reproduction of two hydrophilic vinyl polysiloxane impression materials tested under different conditions. indian j dent res 2011; 22: 8812. 11. zgura l, beica t, mitrofan il, mateias cg, pirvu d, patrascu i. assessment of the impression materials by investigation of the hydrophilicity. dig j nanomater bios 2010; 3: 749-55. 12. powers jm, sakaguchi rl. craig’s restorative dental materials.13th ed. philadelphia: mosby co.; 2012. 13. astm international d2240–05. standard test method for durometer hardness. 2010. west conshohocken, pa. 14. zhang y, zhong s, zhang m, lin y. antibacterial activity of silver-loaded zeolite a prepared by a fast microwave-loading method. j mater sci 2009; 44: 457–62. 15. matsuura t, sato ay, okamoto k, ueshige m, akagawa y. prolonged antimicrobial effect of tissue conditioners containing silver-zeolite. j dent mater 1997; 25: 373–7. 16. bekkum hv, flanigen em, jansen jc. introduction to zeolite science and practice. amsterdam: elsevier; 1991. pp.58. 17. čejka j, bekkum h, corrma a, schűth f. introduction to zeolite science and practice. 3rd revised ed. st. louis: elsevier; 2007. 18. forch r, schonherr h, tobias a. surface design: applications in bioscience and nanotechnology. wileyvch; 2009. 19. nikawa h, yamamoto t, hamada t, rahardjo mb, murata h, nakanoda s. antifungal effect of zeoliteincorporated tissue conditioner against candida albicans growth and/or acid production. j oral rehabil 1997; 24: 350–7. 20. abe y, ueshige m, akagawa tm. cytotoxicity of antimicrobial tissue conditioners containing silverzeolite. int j prosthodont 2003; 16:141-4. 21. azeez za, hattor na. the effect of incorporation of prepared ag-zn zeolite on some properties of heat polymerized acrylic denture base materials. j bagh coll dentistry 2015: 27(1): 63-9. 22. nakanoda s, nikawa h, hamada t, yamamoto t, nakamoto t. the material and antifungal properties of antibiotic zeolite incorporated acrylic resin.j jpn prosthodont soc1995; 39: 926. 23. kaali p, pérez-madrigal mm, strömberg e, aune r e, czél g, karlsson s. the influence of ag+, zn2+ and cu2+ exchanged zeolite on antimicrobial and long term in vitro stability of medical grade polyether polyurethane. express polymer lett 2011; 5(12):1028–40. j bagh college dentistry vol. 28(4), december 2016 the effect of restorative dentistry 27 24. park yj, kim ho, kim mk, han hs, song hj, vang ms. effects of zeolite filler in surfactant-containing silicone rubber impression materials. 86th iadr, 2008. 25. bussaya r. the development of rubber compound based on natural rubber and ethylene propylene die ne monomer for playground rubber material. a master thesis, kasetsart university, 2007. mailto:yjpark@chonnam.ac.kr j bagh college dentistry vol. 31(4), september 2019 priorities and emergency 36 the priorities and emergency treatments of multisystem injuries associated with maxillofacial traumas ahmed orkhan hasan, b.d.s., f.i.b.m.s.(1) abstract background: the purpose of this study is to evaluate the care of multiple trauma victims with maxillofacial injuries in terms of epidemiological distributions, types of injuries, the related different modalities of surgical treatments delivered, and their complications. materials and methods: this prospective study was performed on 50 patients with multiple traumas including maxillofacial injuries, caused by different etiological factors, who were brought first to the surgical emergencies department of the medical city then referred to the maxillofacial unit in the specialized surgeries hospital, baghdad, iraq, during the period from april 2007 to april 2008. information was documented prospectively from the time of the emergency call to discharge (or death). results: the age range was from 6 to 63 years, with the most frequent age group for injury being ranged between 21-30 years. the male to female ratio was 6:1. the missile injuries accounted for 90% of multiple traumas with maxillofacial injuries, while civilian injuries accounted for 10% of the cases. the mechanisms of injury, concerning war injuries, were gunshot injuries 46% and blast injuries 44%, while concerning civilian injuries: road traffic accidents 8% and stabbing injuries 2%. among 50 people injured, 3 (6%) died. conclusion: the priority during initial treatment is the achievement of patent airway, hemostasis, and the maintenance of vital tissues oxygenation. keywords: maxillofacial traumas, multiple traumas, emergency treatments (received: 16/9/2019; accepted: 28/10/2019) introduction according to the who, trauma from industrial accidents, everyday perils, and individual or collective violence causes 3.5 million deaths a year worldwide. the major causes of multiple traumas include car accidents, gunshot injuries, and pedestrian/auto-accidents, crush injuries, and falls. trauma causes considerable losses of productivity, and hence causes social and economic damage (1). it is vitally important to determine the factors that influence the outcome for patients with multiple injuries, because reduction in mortality and morbidity could result in social and economic gains. many studies have attempted to identify prehospital and in-hospital factors related to the outcome of severely injured patients. one of these factors is the time. in trauma care, the timing of intervention is essential. much of “the golden hour”, the time after a trauma in which swift and adequate treatment is of vital importance to improving patient’s outcome, usually passes in the pre-hospital phase. current pre-hospital trauma systems focus on delivering patients, without unnecessary delay, to hospitals within the golden hour. however, scientific evidence supporting these systems, based on the principle of “the golden hour”, is lacking (2). 1. oral and maxillofacial surgeon, azadi teaching hospital, kirkuk health directory, ministry of health and environment. the influence of pre-hospital trauma care and the level of medical expertise needed; pre-hospital trauma life support (phtls) vs. advanced trauma life support (atls) are the subject of discussions all over the world. on-site physicianprovided atls is often associated with invasive, time-consuming interventions, leading to increased on-scene times (osts). increased osts may be associated with increased mortality in severely injured patients (3, 4). injury is the leading cause of death worldwide among those aged 5 to 44 years. in the united states, it is the leading cause of death in the 1 to 44 year age group and the third leading cause of death overall. of the deaths due to injury, 50% occur in the field, 30% occur in the first 24 hours, and 20% are late deaths due to multiple organ failure (mof). of the early deaths, 30% to 50% are due to exsanguinations (5). advanced trauma life support (atls) is widely accepted and used to treat traumatized patients prehospitally. the supporters of atls assume that atls techniques improve survival by providing a definitive airway and preventing aspiration, cervical spine clearance, decreasing hypotension, correcting fluid and electrolyte imbalances (6). trauma can be classified according to both the mechanisms (blunt and penetrating trauma) and circumstances surrounding the trauma j bagh college dentistry vol. 31(4), september 2019 priorities and emergency 37 (unintentional, intentional, self-inflicted, and assault) (7). the multiply injured patients must be received at the resuscitation room by a trauma team led by an atls-trained senior surgeon. (8) facial injuries should alert the examiner to the possibility of airway compromise, cervical spine injuries, or central nervous system, injuries, the latter which is best assessed by glasgow coma scale (9, 10,). first and always first is the maintenance of:-a-airway with cervical spine control, b-breathing and ventilation, c-circulation with hemorrhage control and d-disability, neurosurgical status and eexposure i.e. taking off the clothes to uncover the hidden injuries.(11) the aim of this study is to evaluate the care of multiple trauma victims with maxillofacial injuries in terms of epidemiological distributions, types of injuries, the related different modalities of surgical treatments delivered, and their complications. materials and methods this study included 50 patients with multiple traumas including injuries in the maxillofacial region. the age range of the patients was 6-63 years and the study period extended from april 2007 to april 2008. for every patient in the study a standardized case sheet was performed, which consisted of three main topics: preoperative, operative and postoperative information. the information collected from the patients in the case sheet included the followings: the pre-operative notes which included personal information, medical history, etiology of trauma, associated injuries, extraand intra-oral examination, radiographic assessment, diagnosis, laboratory investigations, consultations with other specialties and medications. this was followed by the operative and post-operative notes. diagnosis was based on history, clinical and radiological examinations (12). the pre-operative preparations included the followings: preliminary measures (abcdes), namely; a (airway), b (breathing), c (circulation), d (disability) and e(exposure) (13),airway assessment and the need for gaining a surgical route to airway has been made. circulatory status is also evaluated to determine the quantity of blood or fluid needed to be transfused after blood grouping and cross matching (14, 15), meanwhile onegative blood group was used. then after, investigations, consultations, and medications were written and requested followed by the immediate surgical operations and post-operative follow-up and rehabilitation results among 50 patients in this study, 43 patients (86%) were males and 7 patients (14%) were females. the male: female ratio was 6:1. the age range of the patients was 6-63 years with a mean age of 32.98 years. of the 50 patients, 45 (90%) sustained war injuries; these were gunshot injuries 46% and blast injuries 44%, while 5 patients (10%) sustained civilian injuries; road traffic accidents (rtas) in 8% and stabbing injuries 2%. twenty patients (40%) presented with compromised airway who underwent tracheostomy (fig. 1) and 30 (60%) with clear airway. sixteen patients (32%) were with frank hypovolemia, 38 patients (76%) were fully conscious, while 10 (20%) were semiconscious and 2 (4%) were unconscious. thirty two patients (64%) presented with mandibular fractures, 15 (30%) with maxillary fractures, 9 (18%) with dentoalveolar fractures, 8(16%) with orbital fractures, 6 (12%) with zygomatic complex fracture, 5 (10%) with isolated nasal fracture, 3 (6%) with frontal bone fracture and 1 (2%) with nasoethmoidal fracture. thirty three patients (66%) had concomitant orthopedic injuries, 16 (32%) with head injury, 15 (30%) with ocular injuries, 11(22%) with chest injuries, 9 (18%) with abdominal injuries and 2 (4%) with spinal injuries. the involved specialties were as follows: 24 (48%) otolaryngology, 19(38%) cardiothoracic surgery, 17(34%) orthopedic surgery, 11 (22%) ophthalmology, 9(18%) plastic surgery, 8(16%) general surgery and 1 (2%) urosurgery. the immediate surgical managements have been established first to save lives and second to do preliminary surgical treatments until more sophisticated methods employed later on. table-1 demonstrates the immediate resuscitating measures, while table-2 shows the immediate surgical operations as teamwork. three patients (6%) died during the emergency treatment. j bagh college dentistry vol. 31(4), september 2019 priorities and emergency 38 table 1: immediate resuscitating measures table 2: initial surgical teamwork treatments *the remaining 9 patients were delayed until the other more urgent surgeries done for them figure 1: patient with severe maxillofacial injury, the airway was secured by a tracheostomy. discussion a male predominance of victims is evident, which can be explained by mostly male drivers, soldiers, and probably in the places where terror attacks occurred. most of the patients were between 21-30 years old. the predominance of young age can be explained by the location of many terrorist attacks in restaurants and social meeting places, the presence of young people, soldiers, or activists on the front line, and the young people, especially males, being more physically active therefore they are at greater risk of injury. gunshot and blast injuries were the most frequent cause in contrast to the civilian ones including rtas. most of injuries were caused by bullets and shell fragments from mortars and explosive cars that had caused penetrating wounds (16, 17).our primary aim with casualties of multisystem injuries is to secure the airway, cervical spine and the circulating volume until more formal treatment could begin (18). triage must first be done by the casualty residents to assess the in-coming cases and assign them to the various specialties (19). concurrent or sequential multidisciplinary operations often take place after management priorities had been agreed. the priority in treatment is to the neurosurgical, cardiovascular, and general surgery departments to deal with more life-threatening injuries first, while maxillofacial injuries can be delayed or managed simultaneously. however the team work is the best i.e. completing all the definite surgeries of all the involved specialties in one operation under the same general anesthesia. to conclude, the priority during initial treatment is the achievement of patent airway, hemostasis, and the maintenance of vital tissues oxygenation. references 1. van beeck ef , van roijen l, mackenbach jp. medical costs and economic production losses due to injuries in the netherlands. j trauma. 1997; 42:1116-1123 2. lerner eb, moscati rm. the golden hour: scientific fact or medical “urban legend”? acad emerg med. 2001; 8:758-760. 3. birk ho, henriksen lo. pre-hospital interventions: onscene-time and ambulance-technicians’ experience. pre-hospital disaster med. 2002; 17:167-169. 4. sampalis js, lavoie a, salas m, nikolis a, williams j. li. determinants of on-scene time in injured patients treated by physicians at the site. pre-hospital disaster med. 1994; 9:178-188; discussion 189. 5. krug eg, sharma gk, lozano r: the global burden of injuries am j public health 90:523-526.2000 % no. of patients type of management %36 18 tracheostomy %2 1 cricothyrotomy %2 1 endotracheal intubation %14 7 chest tube placement 8% 4 ligation of major bleeders % no. of patients type of treatment %22 11 laparatomy %2 1 craniotomy %8 4 amputation %6 3 eye enucleation %16 8 orthopedic treatment %82 maxillofacial treatment 41 ٭ j bagh college dentistry vol. 31(4), september 2019 priorities and emergency 39 6. liebermann m, mulder d, sampalis j. advanced or basic life support for trauma: meta-analysis and critical review of the literature. j trauma 2000; 49:584-599. 7. champion hr, sacco wj, copes ws, et al. a revision of the trauma score. j trauma. 1989:29:623-629. 8. american college of surgeons. committee on trauma. chicago, illinois: advanced trauma life support care course, 1989. 9. jannett b. and teasdale g.(1981). management of head injuries. philadelphia:f.a. davis 10. charles h. thorn. 2007. grabb and smith’s plastic surgery. lippincott williams and wilkins. chapter 31.315. 11. rowe n.l. and williams j.l1.eds (1994). maxillofacial injuries vol.1. edinburgh:churchil livingstone, chap.5.140-141. 12. chan rn, ainscow d and siksorski jm, diagnostic failures in the multiply injured. j trauma 1980; 20:684687. 13. down ke, boot da and gorman df. maxillofacial and associatd injuries in severely traumatized patients: implications of a regional survey. int. j oral maxillofac surg 1995: 24:409-412. 14. yang wg, tsai tr, hung cc, tung tc. lifethreatening bleeding in facial fracture. ann plast surg. 2001: 46:159-162. 15. ardekian l, samat n, shoshani y, taicher s. lifethreatening bleeding following maxillofacial trauma. j craniomaxillofac surg. 1993; 21:336-338. 16. jackson ds, batty cg, ryan jm, et al: the falklands war army field surgical experience. ann r coll surg eng 65:281, 1983 17. banks p: gunshot wounds, in row nl, williams ji,: maxillofacial injuries. london, united kingdom, churchil livingstone, 1994, pp 665. 18. kummoona r. evaluation of immediate phase of management of missile injuries affecting maxillofacial region in iraq. j craniofac surg .2006; 17:217-223. 19. joosse p, goslings jc, et al. m-study; arguments for regional trauma databases. j trauma. 2005; 58:12721276. :الخالصة ين وذلك من ناحية أنواع في هذه الدراسة تم تقييم العناية الجراحية األولية للجرحى الذين يعانون من أصابات متعددة أضافة ألى أصاباتهم في منطقة الوجه والفكالخلفية: وأخيرا المضاعفات. األصابات واألسبقيات في العالج وأنواع العالجات المقدمة لهم مريضا يعانون من أصابات متعددة متضمنة ألصابات الوجه والفكين. لقد كان السبب الرئيسي لهذه األصابات هو ٥۰هذه الدراسة المنظورة أنجزت على المادة والطريقة: مدينة -حصرا في مستشفى الجراحات التخصصية ۲۰۰٨نيسان ۱ى أل ۲۰۰۷نيسان ۱المقذوفات أضافة ألى أسباب مدنية أحرىز تم أنجاز هذه الدراسة في الفترة بين العراق.المعلومات المنشورة عن المرضى تم توثيقها من وقت نداء الطوارئ الى خروج المرضى من المستشفى )أو وفاة بعضهم(.-بغداد-الطب من ٪۹۰. و٦:۱سنة ونسبة الذكور الى االناث كانت ۳۰-۲۱ت تتراوح بين سنة .الفئة العمرية األكثر شيوعت كان ٦۳-٦أعمار المرضى كانت تتراوح بين النتائج: بالنسبة للمقذوفات: -من االصابات كانت بسبب الحوادث المدنية كحوادث المرور والعنف. ميكانيكية االصابات كانت كاالتي: ٪۱۰االصابات كانت بسبب المقذوفات بينما ( ٪٦بسبب طعنات السكاكين. ثالث مرضى ) ٪۲بسبب حوادث الطرق المرورية و ٪٨جارات وبالنسبة للحوادث المدنية: بسبب االنف ٪٤٤بسبب الطلقات النارية و ٪٤٦ م سجيلهمريضا.أثناء فترة الدراسة بعض الجرحى الذين جلبوا الى قسم الظوارئ كانوا قد فارقوا الحياة في طريقهم الى المستشفى, هؤالء لم يتم ت ٥۰فارقوا الحياة من بين في البحث. يوية كالدماغ االولوية في العالج االبتدائي هو لتحقيق مجرى تنفسي مفتوح وضمان سالمة العمود الفقري ووقف النزيف والمحافظة على أكسجة االنسجة الحاالستنتاجات: الصدر واالوعية الدموية,البطن واالطراف وذلك لعالج االصابات االكثر والقلب والرئة والكبد والكلى .األسبقية في المعالجة كانت من نصيب اصابات الجملة العصبية, )وهو االفضل( مع التخصصات خطورة بينما اصابات الوجه والفكين كان باالمكان تأجيلها بشكل مؤقت لحين استقرار الوضع العام للمريض أو اجراء العملية بشكل متزامن االخرى. saad f.doc j bagh college dentistry vol. 25(2), june 2013 comparative study of restorative dentistry 41 comparative study of retention of fiber-reinforced post at middle and cervical one thirds of root canal cemented by polycarboxylate and zinc phosphate cements measured at different storage times saad zabar, b.d.s., m.sc. (1) abstract background: the purpose of this study was to compare regional bond strength at middle and cervical thirds of the root canal among glass fiber-reinforced composite (frc) endodontic posts cemented with different cements, using the push-out test to compare the performance (retention) of two types of luting cements; polycarboxylate cement and zinc phosphate cement used to cement translucent fiber post and to compare the result of the push-out test at different storage times;1 week ,1month and 2 months. materials and methods: ninety caries-free, recently extracted single-rooted human teeth with straight root canals was used in this study, the root canals were endodontically instrumented at a working length of 0.5 mm from the apex by means of conventional instruments for hand use (dentsply, switzerland) up to size 35.then root canal filling was performed followed by post space preparation up to 8mm including cervical and middle one third of root canal then the fiber post was cemented into canal post space then the root was sectioned to get cervical (4 mm in length) and middle (4 mm in length) thirds ,these thirds were examined by push out test to get values of retention of fiber post inside these canal thirds . results and conclusions: the results of this study has been showed that there was no significant differences between push out bond strength between fiber post and root at cervical third as compared with middle third when using polycarboxylate cement or zinc phosphate cement to cement the fiber post to the canal walls and the results showed that there was no significant differences in push out bond strength for polycarboxylate or zinc phosphate cement after one and two months but there was highly significantly increase in push out bond strength for resin cements used to cement the fiber post to the root canal after one and two months keywords: glass fiber post, push out retention, polycarboxylate, zinc phosphate. (j bagh coll dentistry 2013; 25(2):4146). introduction increased post retention and fracture resistance have been reported when posts are cemented with composite cements and conventional luting systems1. the resultant homogeneous biomechanical unit allows a more uniform stress distribution, which better preserves the weakened tooth structure and reduce microleakage at dentine-cement interface, secondary caries and re-infection of the periapical area 2. various luting agents and accompanied adhesives that either follow a self-etch or etchand-rinse approach, can be used to bond fiber posts into root canals. the actual bond strength at the post-cement-root interface is affected by many factors, among which have been described the hydration degree of the root-canal dentin, the kind of conditioning agent and accompanied cement used, the unfavorable cavity configuration of the root canal, the use of eugenol-containing sealers and the anatomical differences in density and orientation of the dentinal tubules at different levels of the root-canal areas 3.the aim of the study was to compare regional bond strength at middle and cervical thirds of the root canal among glass fiber-reinforced composite (frc) endodontic posts cemented with different (1) assistant lecturer. department of conservative dentistry. college of dentistry. university of baghdad. cements, using the push-out test to compare the performance (retention) of two types of luting cements .zinc phosphate and polycarboxylate cements when used to cement translucent fiber post and to compare the result of the push-out test at different storage times various methods are available to analyze the adhesive bond strength of cement and bond strength of the fiber posts. the two most commonly used techniques are the micro tensile bond strength (mtbs) and the push out test. most scientists prefer the push out test for the analysis of fiber posts bond strength to root dentine because it has been documented that the results of this test are more reliable for posts compared to the mtbs test/by using the push out test, the premature loss of samples during the manufacturing of the specimens is reduced. furthermore, the micro push out test enables the measurement of bond strength to very small areas such as the interior of a root canal6. material and methods sample selection ninety caries-free, recently extracted singlerooted human teeth with straight root canals will be used in this study. the inclusion criteria were absence of caries or root cracks, no fractures, no external resoption and x-ray will be taken to j bagh college dentistry vol. 25(2), june 2013 comparative study of restorative dentistry 42 confirm no signs of internal resoption ,no calcification ,single canal and absence of previous endodontic treatments. teeth will be stored in 0.1% thymol at room temperature. preparation of acrylic blocks: each tooth was fixed inside and at the base of clear tube with sticky wax at it apex then the clear acrylic will be mix and pour inside the clear tube till the tooth will be completely embedded inside the clear acrylic, the crown portion of each tooth was sectioned perpendicularly to the long axis of the tooth at the cementum-enamel junction level, using a sectioning instrument under copious water cooling leaving 12mm root length embedded inside acrylic for further steps root canal preparation: the root canals were endodontically instrumented at a working length of 0.5 mm from the apex by means of conventional instruments for hand use (dentsply ; switzerland) up to size 35. after each instrumentation, root canals were flushed with 2 ml of 2.5% sodium hypochlorite and dried with adsorbent paper points. canals were filled with cold lateral gutta-percha condensation using gutta-percha size 35 as master cones and size15as accessory cones, and ah2 root canal sealer the sealer will be mixed, according to manufacturers' instructions. after filling the access chamber with temporary filling material, all root canals were stored in distilled water at 37c for 1 week, 1mounth and 2 month period , to study the effect of storage periods on the results of this study . post space preparation filling material of the middle and cervical thirds was then removed with pesso drills (maillefer-dentsply), and the canal wall of each specimen was enlarged with low speed frc postecl drills (ivoclar, schaan, liechtenstein) under copious water cooling, following the manufacturer's instructions, creating a 8-mm length post space (measured from cementoenamel junction) with a no. 3 post drill, keeping at least 4mm of gutta-percha apically. groups teeth were randomly assigned into three main groups (group a and group b, n=30 each), depending on the type of cement will be used; polycarboxylate cement (dorident ; austria) (a) , and zinc phosphate cement (dorident ; austria) (b). and then each group is sub-divided into three groups (n=10 each), depending on storage period;1 week(a1 and b1), 1 month(a2 and b2) and 2 month period(a3 and b3) each root was sectioned into cervical (a1c,a2c,a3c,b1c,b2c and b3c)and middle(a1m,a2m,a3m,b1m,b2m and b3m) thirds. group a (a1,a2,a3) the post space will be irrigated with distilled water and dried with paper points then the polycarboxylate cement will be mixed according to manufacturer instruction and then will be used to cement the fiber post into post space (8mm of canal filling the middle and cervical one third of the canal space group b (b1,b2,b3) the post space will be irrigated with distilled water and dried with paper points then the zinc phosphate cement will be mixed according to manufacturer instruction and then will be used to cement the fiber post into post space (8mm of canal filling the middle and cervical one third of the canal space preparation of specimens for the push-out bond strength test specimen will attached to the holder to keep it fix and then with sectioning disc under cooling water the specimen will be sectioned perpendicular to the long axis under water cooling. three slices per each root representing cross-sections of cervical ( c ) and, middle (m )of the bounded posts will be obtained. each slice was marked on its apical side with marker. the thickness of each specimen was measured with vernea. the sections will be stored individually in black container with sterile water. push-out tests will be performed by applying a compressive load to the apical aspect of each slice via a cylindrical plunger mounted on a universal testing machine managed by pc software. because of the tapered design of the post, three different sizes of punch pin: 1.1 mm diameter for the coronal, 0.9 mm for the middle, will be used for the push out testing. the punch pin was positioned to contact only the post, without stressing the surrounding root canal walls care will also taken to ensure that the contact between the punch tip and the post section occurred over the most extended area, to avoid notching of the punch tip into the post surface. the load was applied to the apical aspect of the root slice and in an apical-coronal direction, so as to push the post towards the larger part of the root slice, thus avoiding any limitation to the post movement. loading was performed at a crosshead speed of 0.5 mm min) 1 until the post segment was j bagh college dentistry vol. 25(2), june 2013 comparative study of restorative dentistry 43 dislodged from the root slice 3. a maximum failure load value will recorded (netween) and converted into mpa, considering the bonding area of the post segments. post diameters were measured on each surface of the post/dentine sections using the digital caliper and the total bonding area for each post segment was calculated using the formula: π(r1+r2) (r1-r2)2 +h2 where: r represents the coronal post radius, r is the apical post radius and h is the thickness of the slice. all fractured specimens were carefully removed and observed under stereomicroscope at 20 and 50 magnification from the cervical as well as from the apical direction to determine, for each root third, the mode of failure, which were classified into five types5: (i) adhesive between post and resin cement (no cement visible around (ii) mixed, with resin cement covering 050% of the post diameter. (iii) mixed, with resin cement covering 50100% of post surface. (iv) adhesive between resin cement and root canal (post enveloped by resin cement). (v) cohesive in dentine. results the results showed (figure 1 and table 1) that the group (a1c and a2c) has the highest push out bond strength while the group (b2m) has the lowest push out bond strength. a-push out bond strength for zinc phosphate cement and polycarboxylate cement at middle and cervical third of root canal: one-way anova test (table 2) showed that there was statistically significant difference among all the groups at the p value less than 0.01 lsd test (table 3) showed that there was no significant differences between push out bond strength between fiber post and root at cervical third as compared with middle third when using polycarboxylate cement and zinc phosphate cement to cement the fiber post to the canal walls. b-push out bond strength for the type of cement (zinc phosphate cement and polycarboxylate cement): lsd test (table 4) showed that there was higher significant differences between push out bond strength between the two types of dental cements used to cement the fiber post to the root canal. the results showed that polycarboxylate cement has higher bond strength than zinc phosphate cement . c-push out bond strength for zinc phosphate cement and polycarboxylate cement at 1 week, 1 month and 2month storage periods: lsd test (table 5) showed that there was no significant differences in push out bond strength for polycarboxylate cements used to cement the fiber post to the root canal after one and two months the same results gain when using zinc phosphate cement . discussion the objective of a post endodontic restoration is to achieve normal form and function as well as the prevention of fracture of the residual root. other considerations are esthetic, prevention of caries an retention of final restoration6. the amount of tooth structure is a significant factor in determining the fracture resistance of an endodontically treated tooth. it has been shown that endodontically treated tooth restored with posts and cored of different materials and designs tend to exhibit similar fracture resistance when abundant tooth structure remains7. in this study the push out bond strength test was used to evaluate the efficiency of two types of cement used to retain the fiber post in the two thirds of root canal to support tooth structure and retained the final restoration, the finding of the present study were: 1. the effect of root thirds on bond strength of fiber post to the root canal: the result of the present study showed that two types of cements used demonstrate a measurable adhesive property, by using polycarboxylate cements to cement the fiber posts to canal walls the results appeared no difference of bond strength of the post to canal walls at cervical third and middle third. this results interfere with results of (karin et al in 20088) who showed that bond strength to root dentine is higher at coronal part compared to the apical part. several factors may contribute to the reduction in the bond strength from coronal to apical direction. some of these factors are inherited to the root dentin composition, and others are related to the restoration techniques used9.but when using polycarboxylate cement and zinc phosphate cement to cement the fiber posts to canal walls the results appeared no differences in values for the cervical third and the middle may be related to lack of adhesion to the fiber post while there adhesion mechanism to root dentine at the same values for cervical and middle thirds. 2. the effect of type of cements on bond strength of fiber post to the root canal: the result of this study showed higher bond strength gain when polycarboxylate cement was j bagh college dentistry vol. 25(2), june 2013 comparative study of restorative dentistry 44 used as compared with zinc phosphate cement this results coincide with results of michael et al (10) who said that the clinical performance of zinc phosphate cement to lute alloy based restorations seems astonishing because the mechanical and biological properties of this cement are considered to be poor, the compressive strength is lower than those of resin cements. (10) 3the effect of storage period on bond strength of fiber post to the root canal: the result of this study showed that there was no increase in push out bond strength when using polycarboxylate and zinc phosphate cements this may be these cements materials will reach maximum setting reaction and maximum bond strength after shorter period of time thus the different storage periods did not increase the push out bond strength of fiber post to canal walls when using these cement materials (11,12). references 1o'keefe kl, miller bh, powers jm. in vitro tensile bond strength of adhesive cements to new post materials. int j prosth 2000; 13: 47-51. 2reid lc, kazemi rb, meiers jc. effect of fatigue on core integrity and post microleakage of teeth restored with different post systems. j endod 2003; 29:125-31. 3vano m, cury ah, goracci c, chieffi n, gabriele m, tay fr, et al. the effect of immediate versus delayed cementation on the retention of different types of fiber post in canals obturated using a eugenol sealer. j endod 2006; 32:882-5. 4maria d, husamettin g, werner g, anne k. push out strength of fiber posts depending on the type of root canal filling and resin cement. clin oral invest 2011; 15: 273-81(ivsl). 5perdigao j, gomes g, lee ik. the effect of silane on the bond strengths of fiber posts. dental materials 2006; 22: 752-8. 6perel ml, muroff fl. clinical criteria for posts and cores.j prosth dent 1972; 28: 405-11. 7raygot cg, chai j, jameson dl. fracture resistance and primary failure mode of endodontically treated teeth with a carbon fiber reinforced resin post system in vitro. int j prosthodont 2001; 14: 141-5. 8karin k, lutz f, bemd k, norbert h. influence of endodontic post type (glass fiber, quartz fiber or gold) and luting material on push out bond strength to dentin in vitro. dent mater 2008; 5(24): 660-666 (ivsl). 9lopez gc, ballarin a, baratieri ln. bond strength and fracture analysis between resin cements and root canal dentin. aust endod j 2012; 38(1):14-20. 10michael b, martin r, jutta w, reinhold l, carola k, ralf b, gerhard h. self-adhesive resin cement versus zinc phosphate cement luting material: a prospective clinical trial begun 2003 dental materials 2009; 25: 601-604 (ivsl). 11feng l, suh bi. the effect of curing modes on polymerization contraction stress of a self adhesived composite. j biomed mater res b appl biomater 2006; 76(1):196-202. 12graig rg. restorative dental materials. st. louis: the cv. mosby co; 1985. figure 1: push out bond strength (mpa) of all groups of this study. j bagh college dentistry vol. 25(2), june 2013 comparative study of restorative dentistry 45 table 1: mean and standard deviation (mpa) of push out bond strength of all groups of this study table 2: anova test for push out bond strength for polycarboxylate cement and zinc phosphate cement at cervical and middle roots thirds with 1 week, 1 month and 2month storage periods. sum of square df mean square f-test p(value) between groups 1253.28 33 37.98 18.482 p<0.01 within groups 176.72 86 2.505 total 1430 119 d.f.=degree of freedom p-value=probability table 3: lsd test to compare push out bond strength between cervical and middle third of root of tested groups comparism mean differences (i-j) significance (i)group x (j)group (a1c) x (a1m) 0.080 0.931 (a2c) x (a2m) -0.061 0.511 (a3c) x (a3m) 0.055 0.553 (b1c) x (b1m) -0.01 0.941 (b2c) x (b2m) -0.061 0.023* (b3c) x (b3m) -0.13 0.337 * significant at (p<0.05) table 4: lsd test to compare push out bond strength between the two types of dental cements used to cement the fiber post to the root canal. comparison mean differences (i-j) significance (i)group x (j)group (a1c) x (b1c) 2.25 0.000* (a1m) x (b1m) 2.23 0.000* (a2c) x (b2c) 1.99 0.000* (a2m) x (b2m) 1.75 0.000* (a3c) x (b3c) 1.33 0.000* (a3m) x (b3m) 1.15 0.000* * significant at (p<0.05) cement type root third storage period n mean ±sd polycarboxylate cement (a) cervical ( c ) 1 week (a1c) 10 10.22 0.21 1 month (a2c) 10 10.22 0.18 2 month (a3c) 10 10.14 0.21 middle (m) 1 week (a1m) 10 10.2 0.15 1 month (a2m) 10 10.22 0.13 2 month (a3m) 10 10.17 0.13 zinc phosphate cement (b) cervical ( c ) 1 week (b1c) 10 8.98 0.5 1 month (b2c) 10 8.14 0.37 2 month (b3c) 10 8.89 0.43 middle (m) 1 week (b1m) 10 7.99 0.37 1 month (b2m) 10 8.45 0.33 2 month (b3m) 10 9.02 0.37 j bagh college dentistry vol. 25(2), june 2013 comparative study of restorative dentistry 46 table 5: lsd test to compare push out bond strength for polycarboxylate cement and zinc phosphate cement at 1 week, 1 month and 2month storage periods. comparison mean differences (i-j) significance (i)group x (j)group (a1c) x (a2c) 0.085 0.360 (a1c) x (a3c) 0.004 0.966 (a2c) x (a3c) -0.084 0.383 (a1m) x (a2m) 0.016 0.863 (a1m) x (a3m) 0.051 0.582 (a2m) x (a3m) 0.035 0.706 (b1c) x (b2c) -0.15 0.238 (b1c) x (b3c) -0.91 0.000* (b2c) x (b3c) -0.75 0.000* (b1m) x (b2m) -0.45 0.000* (b1m) x (b3m) -1.03 0.000* (b2m) x (b3m) -0.57 0.000* * significant at (p<0.05) journal of baghdad college of dentistry, vol. 34, no. 3 (2022), issn (p): 1817-1869, issn (e): 2311-5270 50 research article determination of surface roughness and accuracy of alginate impression material disinfected by immersion israa mohammed hummudi1* , nidhal sahib mansoor1 1 assistant professor, middle technical university \ college of health and medical techniques, baghdad, iraq *correspondence: karrarnajeh33@gmail.com abstract background: this study was conducted to evaluate the surface roughness and dimensional accuracy of commercially obtainable alginate impression material in terms of imbibition after immersion in two different media. materials and method: two disinfecting agents, ethanol 70% and povidone-iodine 4%, were used to access the dimensional accuracy and surface roughness of alginate impression material. weights of specimen discs of alginate impressions were measured before and immediately after immersion to gain a measure of imbibition. for surface roughness, disinfected specimens rectangle was examined before and after disinfection. results: minimal changes in weight were observed after disinfection, but a statistically non-significant difference was found before and after immersion. it did not affect the surface roughness of alginate impression material conclusion: disinfection of alginate impression material with ethanol and povidone iodine had no significant effect on dimensional accuracy and surface roughness. keywords: alginate, ethanol, povidone iodine, dimensional accuracy, surface roughness. introduction alginate impression is one of the highly contaminated materials between dental laboratory workers and patients. infectious agents are transferred from saliva and blood to the casts via dental impression(1,2). it has been found that 67% of dental material forward from a dental clinic to the lab is contaminated(3). dental materials must be disinfected after making an impression (4,5). various disinfection protocols related to the type and method of disinfection have been proposed for alginate and dental cast(3). immersion and spray application are two different chemical disinfection processes that are carried out on impression(6). american dental association for control guidelines infection advised immersion disinfection of hydrocolloid irreversible impression because it was more reliable and effective. various solutions, such as sodium hypochlorite, formaldehyde, synthetic phenol, iodine, and alcohol, are applied to the chemical disinfection of dental material (7). the seen changes in the dimensional stability and surface chemistry of the impression depend on the type of disinfectant used. one of the adverse effects of disinfection solution is the dimensional change of the impression due to physical and chemical reactions between impression and disinfecting substance (8,9). alginate impression has an imbibition phenomenon that absorbs water within a certain time so it will expand. in addition, alginate can experience syneresis which is a continued reaction because of its ability to expand which may lead to more deformation of impression (10) . various types of research studied the effect generated by imbibition on the surface detail reproduction and dimensions of impression. some studies have agreed that the effect produced is negligible, others have shown that a significant dimensional change is caused by immersion(11).the time for which the disinfection happens is also a contributing factor(12). immersion of impression in disinfectant solutions for a longer time causes changes in the impression, transferred to the cast(13). changes in the properties of gypsum cast, containing dimensional stability, hardness, surface detail reproduction and roughness will affect the accuracy of complete restoration after increasing the time of immersion of an impression(7) . this study received date: 10-1-2022 accepted date: 12-2-2022 published date: 15-9-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license. (https://creativecommons.org/licen ses/by/4.0/). https://doi.org/10.26477/jb cd.v34i3.3234 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3234 https://doi.org/10.26477/jbcd.v34i3.3234 j. bagh. coll. dent. vol. 34, no. 3. 2022 hummudi and mansoor 51 was designed to access the dimensional accuracy due to imbibition phenomena and surface roughness of alginate material immersed in two different chemical disinfectant solutions. materials and methods in this study, alginate material (zhermack, hydrogum) was used. forty specimens were prepared, 20 specimens for the surface roughness test, and 20 specimens for the dimensional accuracy test. each test has two groups (consisting of 10 specimens, each n =10) the study groups were as follows: 1-impressions were immersed in ethanol 70% for 3 minutes 2-impressions were immersed in povidone-iodine 4% for 3 minutes a rectangular silicon mold measuring (521 cm) was used (14). figure (1) a round disk-shaped silicon mold measuring (4mm h, 6 mm w) is used for the dimensional accuracy test(3).figure(2).following the water-powder ratio (18gm / 36 ml) recommended by manufacturer instructions figure (1): dimensional accuracy mold figure (2): surface roughness mold after applying the alginate to the impression mold, a glass slab was placed over the alginate material to ensure the accurate contact of alginate with the mold and a uniform flat surface(15). all of the alginate specimens were allowed to sit for five minutes at 37 cᴼ. after setting, the impression was separated, removed from the mold, and immersed in disinfecting solution(3). figure (3, 4) . figure (3): specimen of dimensional accuracy figure (4): specimens of surface roughness test j. bagh. coll. dent. vol. 34, no. 3. 2022 hummudi and mansoor 52 testing procedure dimensional accuracy test after specimens were constructed, the initial weight for each was measured using an electronic balance (kern ,als 220.4, germany) and was indicated as w1. the specimens were weighed again after immersion. change in percentage weight for each specimen in two different media was calculated.figure (5). figure (5): digital electronic balance surface roughness test the specimens' surface was evaluated using a profilometer (600 s , china), a measurement length of 5 mm /s. the device was adjusted according to the instructions before the measurement and the evaluated measures of each specimen surface; ra's gained surface roughness values were averaged. figure(6). figure (6): surface roughness tester results dimensional accuracy test table (1) presents the descriptive statistics and figure (7) for the alcohol and povidone iodine groups. the mean values of alcohol specimens were decreased after immersion while increased in a povidoneiodine group after immersion. j. bagh. coll. dent. vol. 34, no. 3. 2022 hummudi and mansoor 53 table (1): summary statistics of dimensional accuracy test dimensional accuracy alcohol groups n mean std. deviation std. error mean before 10 .1477 .01121 .00354 after 10 .1382 .01049 .00332 dimensional accuracy povidone iodine before 10 .1454 .00681 .00215 after 10 .1478 .00762 .00241 the f-test results were accounted for nonsig differences before and after immersion in the povidone iodine solution group while significant in the alcohol group before and after immersion. the t-test revealed non – significant before and after immersion for both groups, as in table (2). table (2): fand t-test of experimental groups levene's test for equality of variances t-test for equality of means f sig. t df sig. (2tailed) mean difference std. error difference 95% confidence interval of the difference lower upper dimensional accuracy alcohol equal variances assumed 0.02 0.89 1.959 18 0.066 0.009 0.004 -0.0006 0.0197 equal variances not assumed 1.959 17.921 0.066 0.009 0.004 -0.0006 0.0197 dimensional accuracy povidone iodine equal variances assumed 0.15 0.70 -0.739 18 0.469 -0.002 0.003 -0.0092 0.0044 equal variances not assumed -0.739 17.777 0.469 -0.002 0.003 -0.0092 0.0044 figure (7): bar chart of mean values for experimental groups j. bagh. coll. dent. vol. 34, no. 3. 2022 hummudi and mansoor 54 surface roughness test table (3) presents descriptive statistics. the surface roughness values of alcohol and povidone iodine groups were decreased after immersion—figure (8). table (3):: summary statistics of surface roughness test groups n mean std. deviation std. error mean surface roughness alcohol before 10 1.4785 .33265 .10519 after 10 1.4585 .27289 .08629 surface roughness povidone iodine before 10 1.5620 .32673 .10332 after 10 1.4585 .27289 .08629 the results of the f-test and ttest were accounted for non-sig differences before and after immersion in povidone-iodine and alcohol solution groups as in table (4). table (4): fand t-test of experimental groups figure (8): bar chart of mean values for experimental groups levene's test for equality of variances t-test for equality of means f sig. t df sig. (2tailed) mean differenc e std. error difference 95% confidence interval lower upper surface roughness alcohol equal variances assumed 0.758 0.395 0.15 18 0.885 0.020 0.1361 -0.266 0.3058 equal variances not assumed 0.15 17.337 0.885 0.020 0.1361 -0.2666 0.3066 surface roughness povidone iodine equal variances assumed 1.107 0.307 0.77 18 0.452 0.103 0.1346 -0.1793 0.3863 equal variances not assumed 0.77 17.446 0.452 0.104 0.1346 -0.1799 0.3869 j. bagh. coll. dent. vol. 34, no. 3. 2022 hummudi and mansoor 55 discussion when making an impression, pathogens were transmitted in the oral cavity to the outer environment. the spread of infectious diseases can be prevented due to contamination (16). disinfection of impressions is considered a topic of significance for several years(17). the effect of disinfection treatment on the properties of dental impression and disinfecting solution in removing the pathogen is the main requirement (18). the most workable and dependable method is chemical disinfection by immersion, which does not affect dental impressions and dimensional accuracy(19). irreversible hydrocolloids tend to be hydrated by ethanol. therefore, it should be disinfected for a short time because of imbibition (absorption of water), resulting in inaccurate impressions and casts (20).in this study comparison of alcohol, and disinfectant occurs with povidone-iodine. the observed alginate is a minimum dimensional change in weight immediately after immersion in two media but is statistically non-significant. this is in accordance with the results of the previous study (3) which concluded that disinfection of alginate material with clorax will cause minimal dimensional changes related to imbibition and syneresis, but after thirty minutes, it observed the overall minimal change in weight. the activity of disinfecting agent is not essentially the same for all impressions, depending on the thickness and texture of the impression. to provide maximum accuracy, a uniform thickness of 4-6 mm was proposed for irreversible hydrocolloid rudd and morrow. in this study, the alginate disc was used to measure the dimensional accuracy before and after disinfection with a uniform thickness of 4 mm. the conclusion does not give a significant change in dimensional accuracy. the disinfection procedure should not cause alteration in the surface roughness of impression material. several studies were conducted to estimate the surface roughness of hydrocolloid impression materials. kotha et al.(2017) concluded that chemical disinfection did not significantly affect surface roughness. in this study, no significant differences were found before and after immersion for two disinfectant solutions. this result agrees with ai kheraif (2013), who evaluated polyvinyl siloxane material's surface roughness after various disinfection procedures. conclusions 1the dimensional accuracy of hydrogum alginate material was not affected by immersion in either ethanol or povidone-iodine. 2the immersion time or disinfecting agents did not have a significant effect in terms of surface roughness. acknowledgments thanks and appreciation to mr.jaffer raa'd for his help in prosthetic work. conflict of interest: none references 1. oancea l, bilinsche l g.,burlibasa m.et al. effects of disinfectant solutions incorporated in dental stone on setting expansion, compression and flexural strength of dental models. rom biotechnol lett. 2020; 25(6): 2095-2102. 2. ozdogan a and ozmen mf. effect of two different disinfectant agents on wettability of elastomeric impression materials.2020,9(3):130-138. j. bagh. coll. dent. vol. 34, no. 3. 2022 hummudi and mansoor 56 3. zahid sh, qadir s, zehra bano n, qureshi sw, kaleem m. evaluation of the dimensional stability of alginate impression materials immersed in various disinfectant solutions.pakistan oral and dental journal.2017; april-june,37(2);371-76. 4. celebi h, bukukerkmen eb, torlak e.disinfection of polyvinylsilaxone impression material by gaseous ozone. j prosthet dent.2018;120(1):138-43. 5. karaman t, oztekin f, tekin s, effect of application time of two different disinfectants on the surface roughness of an elastic impression material. j of clinical and diagnosis research.2020; jul,14(7): zc10-zc13. 6. omidkhoda m,hasanzadeh n,soleimani f,shafaee h. antimicrobial and physical properties of alginate impression material incorporated with silver nanoparticles.dent res j.2019;nov-dec,16(6):372-376. 7. mostafavi a, koosha s, amjad m.effect of disinfection on the surface roughness of dental casts retrieved from addition silicon impressions. j res dentomaxillofac sci.2018;3(1):27-33. 8. soganci g,cinar d,caglar a,yagiz a . 3d evaluation of the effect of disinfectants on dimensional accuracy and stability of two elastomeric impression materials.dent mater j.2018;37(4):675-84. 9. mushtaq ma and ullah khan mw. an overview of dental impression disinfection techniquesa literature review.jpda.2018;oct-dec,27(4):207-11. 10. sumantri d and maulida ch.inhibition effect of hydrocolloid irreversible alginate on soaking spray using aloevera juice.intisari sains medis,doaj.2018 ;9(3):24-29. 11. kotha sb, ramakrisknaiah r, devang divakar d, celur sl, qasim s, matinlinna jp.effect of disinfection and sterilization on tensile strength, surface roughness, and wettability of elastomers. j investing clin dent.2017 nov; 8(4):1-6. 12. aalaei sr,gangi-khanloo,gholami f.effect ofstorage period on dimensional stability of alginplus and hydrogum 5.journal of dentistry of tehran university of medical sciences.2017;14(1):p31-39. 13. demajo jk, cassar v, farrugia c, millan-sango,d, sammut c, valdramidis v, et al. effectiveness of disinfectants on antimicrobial and physical properties of dental impression materials. int j prosthodont. 2016 jan-feb;29(1):63-7. 14. saji p, mohamed r, noufal pk, sesha reedy p, jain ar, varma a, gounder r.compartive evaluation of the influence of cast hardening agents on surface abrasion, surface hardness and surface detail reproduction properties of refractory investment materials. biomedical and `pharmacology journal.2017;10(3):1517-1524. 15. dreesen k,kellens a, wevers m, thilakarathne pj, willems g.the influenceof mixing methods and disinfectant on the physical properties of alginate impression materials.european journal of orthodontics.2013;35:pp.381-87. 16. sharif ra, abdelaziz km, alshahrani nmz, almutairi fs, alaseri ms, lotfy abouzeidh,. elagib mf. dimensional stability and surface details reproduction of two extended-pour alginate materials: a function of chemical disinfection and storage time. an invitro study. research article.jan 2021;doi: https://doi.org/10.21203/rs.3.rs-41597/v1 17. rentzia a, coleman dc, o´donnall mj, dowling ha, o´sullivan m. disinfection procedure: their efficacy and effect on dimensional accuracy and surface quality of an irreversible hydrocolloid impression material. j dent. 2011;39(2):133–40. 18. malaviya n, shrestha a.compartive evaluation of surface detail changes and compressive strength of gypsum casts and dies after immerssion in hypochlorite soluttion and microwave irradiation.an in vitro study.ijcmr.2016;3(6):154751. 19. doddamani s, patil ra, gangadhar sa. effcacy of various spray disinfectants on irreversible hydrocolloid impression materials: an in vitro study. indian j dent res. 2011;22(6):764–9. 20. kotsiomiti e, tzislla a, hatjivasiliou k.accuracy and stability of impression materials subjected to chemical disinfection . a literature review.journal of oral rehablitation.may 2008; 35(4):291-9 j. bagh. coll. dent. vol. 34, no. 3. 2022 hummudi and mansoor 57 تحديد خشونه السطح ودقه طبعة ماده االلجنيت بعد تطهيرها بالغمر صاحب منصور اسراء محمد حمودي, نضال المستخلص الخلفية:: تهدف هذه الدراسه الى تحديد خشونه السطح ودقه طبعة ماده االلجنيت بعد تطهيرها بالغمر ايثانول المطهرات من نوعين استخدام تم العمل: وطرق ايودين 70المواد وبوفيدون الدقه %4 لقياس قرص شكل على االلجنيت ماده من عينه استخدام .تم % بواسطه الوزن قبل الغمر وبعده اما خشونه السطح فشكل العينه مستطيل وقد استخدم جهاز خشونه السطح للقياس قبل وبعد الغمر. ر بعد لوحظ انه لم يتاثالنتائج: لقد لوحظ وجود تغييرات طفيفه لقياس الدقه بواسطه الوزن ولكن احصائيا لوحظ عدم وجود اي تغيير اما بالنبسبه لخشونه السطح ف الغمر.. % اليؤثر على دقه الطبعه وكذلك خشونه السطح.4% والبوفيدون ايودين 70االستنتاجات: تم االستنتاج الى ان تعقيم ماده طبعه االلجنيت بواسطه االيثانول arkan.doc j bagh college dentistry vol. 28(1), march 2016 the soft tissue pedodontics, orthodontics and preventive dentistry 133 the soft tissue changes following orthodontic treatment of bimaxillary protrusion (a clinical and photographical study) arkan muslim, b.d.s., m.sc. (1) hayder a. kadhim, b.d.s., m.sc. (2) abstract background: bimaxillary protrusion is considered as one of the most important causes to seek the orthodontic treatment to get better esthetics. this study aimed to test the effect of orthodontic treatment in improvement the facial esthetics. materials and methods: ten iraqi arab females having bimaxillary protrusion based on class i malocclusions treated with fixed orthodontic appliance and extraction of the maxillary and mandibular 1st permanent premolars. pre and post-treatment facial profile photographs were taken for each patients and the effect of treatment was tested in comparison with the pre-treatment photographs by using seven angular measurements. results: after treatment, the upper and lower lip projections were decreased significantly, the naso-labial and mento-labial angles were increased significantly. conclusion: treatment of bimaxillary protrusion with fixed orthodontic appliances and extraction of four premolars improve the facial esthetics of the patients by decreasing the lip projection and increasing the naso-labial and mento-labial angles. key words: bimaxillary protrusion, facial esthetics, photographs. (j bagh coll dentistry 2016; 28(1):133-137). introduction bimaxillary dentoalveolar (bialveolar) protrusion is defined as an anterior position and labial inclination of the maxillary and mandibular incisors with respect to their supporting bones and the facial profile (1). patients with bimaxillary protrusion demonstrated increased incisor proclination and protrusion, a vertical facial pattern, increased procumbency of the lips, a decreased nasolabial angle, thin, elongated upper and lower anterior alveoli (2-4). bimaxillary protrusion is seen commonly in african-american and asian population, but it can be seen in almost every ethnic group. because of the negative perception of protrusive dentition and lips in most cultures, many patients with bimaxillary protrusion seek orthodontic care to decrease the procumbency (5-8). the etiology of bimaxillary protrusion is complex involving environmental factors, genetic component, soft tissue function, volume and habit (9). the goals of orthodontic treatment of bimaxillary protrusion include the retraction of both maxillary and mandibular incisors to decrease soft tissue procumbency and facial convexity. the extraction treatment has gained the popularity due to its greater long-term stability and greater esthetic changes after treatment especially in those cases where there is dentoalveolar protrusion. (1)lecturer. department of pop, college of dentistry, university of babylon. (2)assistant lecturer. department of pop, college of dentistry, university of kufa. the common treatment approach involves extraction of first four premolars with maximum anchorage mechanics (8). in iraq, ismael (10) identifies the cephalometric features of bimaxillary protrusion in ninety four mosuli adolescents with class i normal occlusion. the present study aimed to demonstrate the effect of orthodontic treatment on the facial profile of bimaxillary protrusion cases. materials and methods sample ten female patients with an age ranged between 17-22 years, had bimaxillary dentoalveolar protrusion based on class i angle' classification malocclusion were selected in this study. all of them were white iraqi arab in origin and had full permanent dentition regardless the wisdom teeth with minimal crowding (1-2mm.). methods standardized profile photographs with frankfort plane horizontal using canon power shot sd750 digital elph (7.1 megapixel, japan) camera with a 100 cm distance from the patient were taken prior to the orthodontic treatment. after dental extraction of the maxillary and mandibular first permanent premolars, roth stainless steel brackets (bionic, orthotechnology co., usa) with 0.022" slot were bonded on the maxillary and mandibular teeth using no-mix orthodontic composite (orthotechnology co., usa). orthodontic bands with roth prescription were cemented on the first and second permanent j bagh college dentistry vol. 28(1), march 2016 the soft tissue pedodontics, orthodontics and preventive dentistry 134 maxillary and mandibular molar teeth using glass ionomer cement. trans-palatal and lingual bars were constructed to get good anchorage during anterior teeth retraction. firstly, maxillary and first mandibular permanent premolars were extracted, leveling and alignment phase was completed by using niti sequence archwires with cinch back posteriorly. then, canines were retracted on 0.018" stainless steel archwires, with stopper in front of the 1st molars and cinch back posteriorly, using elastomeric chain with 150 gm. finally the anterior teeth were retracted with closing loop on 0.017 × 0.022" stainless steel archwires. finishing was done with 0.019 × 0.025" niti, stainless steel archwires and settling of occlusion was completed then the orthodontic applainces were removed in about two years of treatment. second profile photographs were taken after the orthodontic treatment and the effect of treatment was compared. photographic analysis every profile facial photograph was analyzed by autocad program 2008 to calculate the angular measurements. once the picture was imported to the autocad program, the points and lines would appear that determine the obtained measurement. photographic points, lines and angular measurements (11) points 1. point na’ (nasion soft tissue): the point of deepest concavity of the soft tissue contour of the root of the nose. 2. point nt (nasal tip): the most protruded point of the apex nasi. 3. point cm (columella): the most anterior point on the columella of the nose. 4. point sn (subnasale): the point where the lower border of the nose meets the outer contour of the upper lip. 5. point ls (labrale superious): the median point in the upper margin of the upper membranous lip. 6. point li (labrale inferius): the median point in the lower margin of the lower membranous lip. 7. point b’ (soft tissue b): the point of greatest concavity in the midline of the lower lip between labrale inferius and menton. 8. point pog’ (soft tissue pogonion): the most prominent point on the soft tissue contour of the chin. 9. point ct (chin tangent): the most anterosuperior point on the soft tissue chin where the concavity of the soft tissue changes to convexity. 10. point or (soft tissue orbitale): the lowest point on the lower margin of each orbit. it is identified by palpation and is identical to the bony orbitale. 11. point po (soft tissue porion): the highest point of the upper margin of the cutaneous auditory meatus. lines 1. frankfort horizontal plane: it extends between soft tissue porion and orbitale. 2. na'-pog' line: it extends between soft tissue nasion and pogonion. 3. na'nt line: it extends between soft tissue nasion and the tip of the nose. 4. sn-cm line: it extends between subnasale and columella. 5. sn-ls line: it extends between subnasale and labrale superious. 6. na'-ls line: it extends between soft tissue nasion and labrale superious 7. na'-li line: it extends between soft tissue nasion and labrale inferius. 8. li-b' line: it extends between labrale inferius and soft tissue b. 9. ct-b' line: it extends between chin tangent and soft tissue b. 10. na'-sn line: it extends between soft tissue nasion and subnasale. 11. sn-pog' line: it extends between soft tissue subnasale and pogonion. 12. pog'nt line: it extends between soft tissue pogonion and the tip of the nose. angular measurements 1. na'-ls/fh: the inferior, inner facial angle formed by the intersection of a line drawn from nasion (na') to labrale superiors (ls) and frankfort plane (fh). 2. na'-li/fh: the inferior, inner facial angle formed by the intersection of a line drawn from nasion (na') to labrale inferius (li) and frankfort plane (fh). 3. naso-labial angle: the angle formed between columellasn line and sn –ls line. 4. na'-pog’/fh (facial divergence): the inferior, inner facial angle formed by the intersection of a line drawn from nasion (na') soft tissue pogonion (pog') and frankfort plane (fh). 5. na'-sn-pog' (profile angle): the inner angle between na'-sn and sn-pog' lines. 6. na'ntpog': the inner angle between na' nt and ntpog'. 7. labio mental angle (li-b'-ct): the intersection angle at point (b') of the lines j bagh college dentistry vol. 28(1), march 2016 the soft tissue pedodontics, orthodontics and preventive dentistry 135 extending from the laberale inferius (li) and the tangent to the chin. statistical analyses all the data of the sample were subjected to computerized statistical analysis using spss version 20 computer program. the statistical analysis included: 1. descriptive statistics: means and standard deviations. 2. inferential statistics: paired-samples ttest to test the treatment effect. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results table 1 showed the descriptive statistics and treatment effect of the bimaxillary protrusion of extraction of four premolars. the results showed highly significant decrease in the upper and lower lips protrusion and increase in the naso-labial and mento-labial angles. the facial divergence and profile angle showed non-significant difference. table 1. descriptive statistics and treatment effect on the angular measurements. angular measurements (degree) descriptive statistics difference (d.f. = 9) before treatment after treatment mean s.d. mean s.d. mean difference t-test p-value na'-ls/fh 102.6 3.89 89.7 4.11 12.9 129 0.000 (hs) na'-li/fh 99.6 3.89 94.7 3.83 4.9 49 0.000 (hs) naso-labial angle 76.1 3.35 93.2 3.49 -17.1 -171 0.000 (hs) na'-pog’/fh 89.6 3.06 88.9 3.13 0.7 19 0.142 (ns) na'-sn-pog' 167.9 3.28 168.8 3.22 -0.9 -9 0.257 (ns) na'ntpog' 130.85 3.02 131.325 3.32 -0.475 -0.513 0.621 (ns) labio mental angle 124.95 2.95 141.85 2.81 -16.9 -169 0.000 (hs) discussion when a decrease of lip procumbency is wanted, extracting premolars and retracting incisors is a practicable option to complete these objectives. on the basis of the patient’s chief complaint and the diagnosis of the malocclusion, extracting the maxillary and mandibular first premolars was indicated (12). when extracting premolars is preferred to correct the malocclusion, the treatment plan must address space closure of the extraction sites. closure of the extraction sites can happen by retraction of the anterior segments, protraction of the posterior segments, or a combination of the two (13). maximum anchorage indicates to prevent mesial movement of the posterior segments in the anteroposterior dimension. maximum anchorage in this case was necessary and predicated on the need to restrict mesial movement of the maxillary and mandibular first molars until the crowding and bimaxillary protrusion were resolved. to increase anchorage, adjunctive appliances, such as a trans-palatal bar, a nance holding arch, palatal implants, or extra-oral traction, are usually necessary. intraoral sources of anchorage include alveolar bone, teeth, dental arches, palatal and mandibular basal bone and differential moment mechanics (13). renfroe (14) stated that, to be stable, the anchorage unit must be overwhelmingly more resistant than with the moving teeth. in this case, anchorage in the maxilla was achieved with a trans-palatal bar, bonding of the second molar, and class ii elastics. mandibular anchorage was achieved by bonding the second molars. nowadays, mini-implants provide excellent anchorage control and considered to be effective that the trans-palatal bar. in this study, transpalatal and lingual bar were used on the maxillary and mandibular first and second molars to increase the anchorage. generally the prominence of the upper and lower lips was reduced significantly about 12.9 degrees for the upper lip and about 4.9 for the lower lip; this is due to the retraction of the maxillary and mandibular incisors (15,16). figure 1 confirms that the naso-labial and labio-mental angles were increased significantly due to the retraction of the maxillary and mandibular anterior teeth; this comes in agreement with bravo (15). sukhia et al. (16) who found significant increase for the naso-labial angle and non-significant for labio-mental angle. j bagh college dentistry vol. 28(1), march 2016 the soft tissue pedodontics, orthodontics and preventive dentistry 136 lo and hunter (17) reported that the greater the maxillary incisor retraction the greater the increase in the naso-labial angle. in the present study, the naso-labial angle was increased about 17 degrees. the soft tissue nasion and the tip of the nose to the soft tissue pogonion revealed non-significant difference after treatment. this indicates that the retraction of the anterior teeth may not affect the underlying basal bone and hence the soft tissue pogonion followed the bony one, so the soft tissue profile is not affected. the small change in na'sn-pog' angle (0.9 degrees) was attributed to the backward position of the subnasale after treatment. as a conclusion; treatment of bimaxillary protrusion with fixed orthodontic appliances and extraction of four premolars improves the facial esthetics of the patients by decreasing the lip projection and increasing the naso-labial and mento-labial angles. careful evaluation of patients with bimaxillary protrusion is needed to gain more information on the possible consequences of incisor retraction, so one should bear in mind that individual variation in response is great. therefore, it would be prudent to inform the patient of average changes to expect, while also informing the patient that in his/her particular instance, this could be different. before treatment after treatment figure 1: case pre and post treatment. references 1. tsai hh. cephalometric characteristics of bimaxillary dentoalveolar protrusion in early mixed dentition. j clin pediatr dent 2002; 26(4): 363-70. 2. diels rm, kalra v, deloach n jr, powers m, nelson ss. changes in soft tissue profile of african americans following extraction treatment. angle orthod 1995; 65(4): 285-92. 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(ivsl). 16. sukhia rh, sukhia hr, mahdi s. soft tissue changes with retraction in bimaxillary protrusion orthodontic cases. pakistan oral dent j 2013; 33(3): 480-5. 17. lo fd, hunter ws. changes in nasolabial angle related to maxillary incisor retraction. am j orthod 1982; 82(5): 384-91. wasan f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 89 the effect of autologous bone marrow-derived stem cells with estimation of molecular events on tooth socket healing in diabetic rabbits (immunohistochemical study) mohamed a.h. mohamed, b.d.s, m.sc. (1) wasan h. younis, b.d.s, m.sc., ph.d. (2) nahi y. yaseen, m.sc., ph.d. (3) abstract background: healing of a tooth extraction socket is a complex process involving tissue repair and regeneration. it involves chemotaxis of appropriate cells into the wound, transformation of undifferentiated mesenchymal cells to osteoprogenitor cells, proliferation and differentiation of committed bone forming cells, extracellular matrix synthesis, mineralization of osteoid, maturation and remodeling of bone. these cellular events are precisely controlled and regulated by specific signaling molecules. some of these like transforming growth factor beta (tgf-β), vascular endothelial growth factor (vegf), bone morphogenetic proteins (bmp) and insulin like growth factors (igf) are well conserved proteins involved in the initial response to injury and repair in soft and hard tissue. materials and methods: 48 rabbits weighting an average of (2.5 3 kg) were used in this experimental study, and divided into 3 groups as follows; group a ( contains 16 healthy rabbits regarded as control group ) , group b ( contains 16 diabetic rabbits not received treatment ), group c ( contains 16 controlled diabetic rabbits received insulin as a treatment ), the lower incisor for each rabbits was extracted, after 2, 10, 20 and 30 days of healing periods after scarification , the socket was analysed by immunohistochemical (ihc) estimation of growth factors : tgfbeta-3 , vegf , igf-1r , bmp-4 . results: ihc findings revealed high positive expression of tgfbeta-3, bmp-4 on fibroblasts, osteoproginetor cells, osteoblasts and osteocytes,high positive expression of vegf on endothelial cells and high positive expression of igf-1r on endothelial cells and moderate expression on osteoblasts. conclusions: the inhibition of proliferation and migration of osteoblasts, or differentiation from progenitor cells, is implicated in the delay of teeth sockets healing. for this fact the results of the present study concluded that in the diabetic healing bone (rabbits of group b), the onset of cell proliferation and osteoblast differentiation were delayed and subsequently prolonged healing process when compared with the other groups (rabbits of group a,cand d). key words: growth factors and tooth socket healing, experimental diabetic animals, delay socket healing. (j bagh coll dentistry 2013; 25(special issue 1):89-95). introduction diabetes mellitus is a chronic, widely spread human disease. experimental induction of diabetes mellitus in animal models is essential for the advancement of our knowledge and understanding of the various aspects of its pathogenesis and ultimately finding new therapies and cure. several methods have been used to induce diabetes mellitus in laboratory animals with variable success and many difficulties. surgical removal of the pancreas is effective method; however, to induce diabetes, at least 90-95% of the pancreas has to be damaged (1) . alloxan is a naturally occurring, broad spectrum antibiotic and cytotoxic chemical that is particularly toxic to the pancreas (2). induction of experimental diabetes in the rabbit using alloxan is very convenient and simple to use. alloxan injection leads to the degeneration of the langerhans islets beta cells clinically; symptoms of diabetes are clearly seen in rabbits within 2-4 days following single intravenous or intraperitoneal injection of 100 mg/kg (3). (1) ph.d. student, department of oral diagnosis, college of dentistry, baghdad university. (2) professor, head of oral diagnosis department, college of dentistry, baghdad university. (3) professor, general manager of iraqi center for cancer and medical genetic research. healing of a tooth extraction socket is a complex process involving tissue repair and regeneration. it involves chemotaxis of appropriate cells into the wound, transformation of undifferentiated mesenchymal cells to osteoprogenitor cells, proliferation and differentiation of committed bone forming cells, extracellular matrix synthesis, mineralization of osteoid, maturation and remodeling of bone. these cellular events are precisely controlled and regulated by specific signaling molecules. (4-10). studies of the spatial and temporal expression patterns of several growth factors (vegf, tgfbeta, bmp-4 and igf-1r) and the close correlation of their expression with local histological events showed that they play important roles in the healing process of tooth extraction sockets. materials and methods sixty four adult rabbits weighting an average of (2.5 3 kg) were used; the experimental animals were divided into four groups as follows: group a: contains 16 healthy rabbits regarded as control group. group b: contains 16 diabetic rabbits, not received any treatments. j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 90 group c: contains 16 controlled diabetic rabbits received insulin as a treatment. group d: contains 16 diabetic rabbits received mscs as a treatment. induction of diabetes mellitus in rabbits (group b, c and d rabbits) the rabbits were injected by a single dose (120 mg/kg) intravenous injection of the pancreatic betacells toxin monohydrate (alloxan), which was administered to the rabbits via the marginal ear vein(fig.1). severity of the induced diabetic state was assessed by daily monitoring of blood glucose levels with a calibrated glucose meter (few drops from the ear) and daily estimation of the body weight. for determination of blood glucose level, the animals whose blood glucose level was greater than 200mg / dl were indicated as hyperglycemic. five to seven days after injection, alloxan induced diabetes by destroying the beta cells of the pancreas; the blood glucose level was elevated above the 200mg/dl. animals of group c were received daily insulin as a treatment in a dose of 0.1 mg/ kg of body weight. isolation of mscs from the bone marrow (group d rabbits) the surgery was performed under well sterilized condition and gentle surgical technique. the surgical towels were placed around the site of operation; the site chosen for operation was the proximal tibia metaphysis of the right limb (fig.2). figure 1: alloxan injection skin incision was done by using a sharp blade to expose the muscle (fig.3). then the muscle was dissected to expose the tibia (fig.4). by intermittent drilling with (1 mm surgical drill) and continuous, vigorous irrigation with sterile normal saline, a guide hole was made (fig.5). by using sterile syringe (5ml) that contains few drops of heparin (to prevent blood clotting) the bone marrow was aspirated as soon as possible (fig.6). after that the area was washed very well with a sterile normal saline, the muscle was sutured with 3/0 absorbable (catgut) suture (fig.7). the skin was sutured with interrupted 3/0 silk suture (fig.8). figure 2: the site of operation figure 3: skin incision figure 4: dissection of the muscle figure 5: 1mm guide hole figure 6: aspiration of bone figure7: cat gut suture was made marrow figure 8: skin sutured with silk suture j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 91 inside the hood the bone marrow was inserted into two test tubes t.t.), equal volumes of phosphate buffer saline (pbs) was added to (t.t.) and shake very well ,then the two t.t. was put inside the centrifuge (2000 rpm) for 10 minutes. inside the hood the top two thirds of the solution were removed. rpmi-culture media was added to the precipitate 1/3 of the t.t. & shake very well until the media was became homogenous, then the media was added into a well sterilized plastic falcons & covered very well by a parafilm, finally the media was incubated at (37 °c, 5% co2 & 95% air).the cells were checked periodically under inverted microscope, the culture media was changed twice a week for two weeks. with the medium changes, almost all the non adherent cells were washed away. differentiation of mscs into insulin producing cells 1inside the hood about 2/3 of the medium in the falcons was removed and pre-inducing medium was added to the remaining 1/3 of the falcons, the pre-inducing medium containing low glucose– rpmi (l-rpmi) supplemented with 10 mm nicotinamide, plus 1 mm beta-mercaptoethanol and 10% of fetal bovine serum (fbs), then covered by a parafilm and incubated at (37 °c, 5% co2 & 95% air) (for 24 hours). 2the medium was changed with fresh inducing medium; containing serum free high glucose– rpmi (h-rpmi) , supplemented with 10 mm nicotinamide , plus 1 mm beta-mercaptoethanol , then covered by a parafilm and incubated at (37 °c, 5% co2 & 95% air) (for 10-12 days). detection of insulin producing cells the insulin producing cells can be detected by dithiazone (dtz) stain. dtz is a zinc-chelating agent known to selectively stain pancreatic beta cells because of their high zinc content. inside the hood about 2/3 of the medium was removed from the falcon, then 2 ml of dtz solution was added for the remaining 1/3 of the medium in the falcon that containing the mscs, the cells were incubated at (37 °c, 5% co2 & 95% air) for 30 minutes and examined under inverted microscope. reimplantation of mscs 5 ml of the medium was reimplanted to the rabbits by subcutaneous injection. under sterile condition and gentle surgical technique, the lower incisor of each rabbits for all groups was extracted. 2 days after extraction 4 rabbits from each group were killed; 10 days after extraction another 4 rabbits from each group were sacrificed; 20 days after extraction another 4 rabbits from each group were sacrificed; 30 days after extraction the remaining 4 rabbits from each group were sacrificed; the sockets blocks were immediately fixed in 10% formaldehyde solution and processed for ihc evaluations of growth factors : tgf beta-3 , vegf , igf-1r and bmp4, statistical analysis (pearsons correlation) with scoring and positive cells counting at different healing periods was done. results immunohistochemical examination of tgfbeta-3 the human placenta was used as a positive control for detection of tgfbeta-3 (fig.9),the immunostaining was detected as brown color for both cytoplasm and cell membrane. the ihc staining with tgfbeta-3 was positive in the fibroblasts, osteocytes and osteoblasts of groups a , c and d in comparison with group b animals (fig.10 and fig.11). fig.9: the human placenta was used as positive control for tgf-beta expression, dab stains with counter stain hematoxylin, 40 x. fig.10: positive expression of osteocytes (oc), and osteoblasts (ob) , 30 days healing period dab stain with counter stain hematoxylin, 40 x. fig.11: view for positive expression of tgfbeta on osteocytes (oc) and osteoblasts (ob), 20 days healing period dab stain with counter stain hematoxylin, 40 x. j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 92 immunohistochemical examination of vegf the human kidney was used as positive control for detection of vegf (fig.12), the ihc staining with vegf was positive in endothelial cells of the blood vessels (fig.13), while negative in osteocytes and osteoblasts. groups a,c and d animals have great numbers of blood vessels in comparison with group b. immunohistochemical examination of igf-1r the human placenta was used as a positive control for detection of igf-1r ,the ihc staining with igf-1r was highly expressed in extracellular matrix and endothelial cells in rabbits of groups b, c and d in comparison with group a animals, while moderately expressed on osteoblasts and negative expression on osteocytes (fig.14 and fig.15). immunohistochemical examination of bmp4 the human kidney was used as positive control for detection of bmp-4, the ihc staining with bmp-4 was positive in the fibroblasts, osteocytes and osteoblasts of groups a , c and d in comparison with group b animals (fig.16 and fig.17). fig.12: the human kidney was used as positive control for vegf expression, dab stains with counter stain hematoxylin, 40 x. fig.13: positive expression of vegf on endothelial cells of blood vessels (arrows) at 10 days healing period, dab stain with counter stain hematoxylin, 40 x. fig.14 positive ihc dab stain for localization of igf-1r on blood vessels(arrows)and osteoblasts(ob), dab stain with counter stain hematoxylin, 40 x. fig.15 positive ihc dab stain for localization of igf-1r on blood vessels (arrows), dab stain with counter stain hematoxylin, 40 x. fig.16: positive ihc dab stain for localization of bmp-4 on fibroblasts (arrows), dab stain with counter stain hematoxylin, 40 x. fig.17: positive ihc dab stain for localization of bmp-4 on osteoblasts (red arrows) and osteocytes (black arrows),dab stain with counter stain hematoxylin, 40 x. ob j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 93 ihc scoring of tgf beta-3 table 1: the positive cells percentage counting of tgf beta -3 at all healing periods periods group a group b group c group d 2 days 73% 52% 70% 71% 10 days 65% 20% 63% 62% 20 days 52% 23% 48% 47% 30 days 45% 18% 43% 44% ihc scoring of vegf table 2: the positive cells percentage counting of vegf at all healing periods periods group a group b group c group d 2 days 70% 45% 65% 67% 10 days 68% 23% 65% 67% 20 days 45% 35% 44% 43% 30 days 20% 45% 22% 23% ihc scoring of igf-1r table 3: the positive cells percentage counting of igf-1r at all healing periods periods group a group b group c group d 2 days 20% 35% 30% 31% 10 days 17% 30% 24% 22% 20 days 17% 23% 21% 20% 30 days 14% 20% 18% 19% ihc scoring of bmp-4 table 4: the positive cells percentage counting of bmp-4 at all healing periods periods group a group b group c group d 2 days 48% 40% 45% 46% 10 days 65% 40% 62% 60% 20 days 62% 35% 61% 63% 30 days 45% 23% 42% 41% statistical correlations of all markers among groups at all healing periods statistical correlations of all markers in group a at all healing periods according to the pearson correlation (table 5), there was a significant correlation between tgfbeta and vegf. in addition to a significant correlation between tgf-beta and bmp-4. while showed a non-significant correlation between the other markers. statistical correlations of all markers in group b at all healing periods according to pearson correlation (table 6), there was a significant correlation between tgf-beta and igf1r. in addition to a significant correlation between igf1r and bmp-4. while showed a nonsignificant correlation between the other markers. statistical correlations of all markers in group c at all healing periods according to the pearson correlation (table 7), there was a significant correlation between tgfbeta and vegf, between tgf-beta and igf1r. in addition to a significant correlation between vegf and igf1r. while showed a non-significant correlation between the other markers. statistical correlations of all markers in group d at all healing periods according to the pearson correlation (table 8), there was a significant correlation between tgfbeta and vegf, between tgf-beta and igf1r. in addition to a significant correlation between vegf and igf1r. while showed a non-significant correlation between the other markers. table 5: pearson correlation between all markers in group a at all intervals markers rabbits no. of each group pearson correlation sig. (2-tailed) tgf-beta vegf tgf-beta bmp-4 16 16 0.908** 0.533* **. correlation is significant at the 0.01 level (2-tailed). *. correlation is significant at the 0.05 level (2-tailed). table 6: pearson correlation between all markers in group b at all intervals markers rabbits no. of each group pearson correlation sig. (2-tailed) tgf-beta igf1r 16 0.689** igf1r bmp-4 16 0.789** **. correlation is significant at the 0.01 level (2-tailed). table 7: pearson correlation between all markers in group b at all intervals markers rabbits no. of each group pearson correlation sig. (2-tailed) tgf-beta vegf tgf-bet igf1r 16 16 .891** .843** vegf igf1r 16 .790** **. correlation is significant at the 0.01 level (2-tailed). j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 94 table 8: pearson correlations among all markers in group d at all intervals markers rabbits no. of each group pearson correlation sig. (2-tailed) tgf-beta vegf tgf-beta igf1r 16 16 0.901** 0.835** vegf igf1r 16 0.684** **. correlation is significant at the 0.01 level (2-tailed). discussions the morphology and physiology of the rabbit oral apparatus are well known and the mechanical properties of its incisors and periodontal ligaments have been thoroughly examined , therefore it is suggested to be the experimental animal of choice in the present study (12 , 13 , 14). osteoblast growth and differentiation is determined by a complex array of growth factors and signalling pathways. the following three families of growth factors influence the main aspects of osteoblast activity and induce, mediate or modulate the effects of other bone growth regulators: tgf-β , igfs and bmps (15,16,17), furthermore, other growth factors, such as the vegf, as well as platelet derived growth factor (pdgf) are involved in bone formation. many growth factors involved in the natural process of bone healing have been identified and tested as potential therapeutic candidates to enhance the regeneration process (18 , 19).bone-related growth factors, including tgf beta-3, vegf, igf-1r and bmp-4 were selected in this experimental study. the current results showed that the fibroblasts, osteoproginator cells and osteoblasts had a strong positive expression with tgf-b monoclonal antibody at early stages of socket healing (10 days), while started to be decreased to become moderately expressed at 20 and 30 days, these findings agreed with spinella who demonstrated (regarding the effect of tgfbeta on the differentiation of osteoprogenitor cells, most studies agree that tgf-b have a positive function in the early differentiation stage but an inhibition effect on differentiation in the terminal stage) (20) , the results showed that the endothelial cells and endothelial progenitor cells were highly expressed with vegf at early healing periods (2 and 10 days), while decreased in expression at 20 and 30 days of healing periods , also the current result showed that the number of blood vessels and endothelial progenitor cells which positively expressed with vegf was higher in groups a and c than those of group b. this data suggests that diabetes delays wound healing of the tooth extraction socket by inhibiting angiogenesis; these results were in agreement with cross et al (21) , the results also showed that at 2 and 10 days of healing period the immunohistochemical staining, with igf-1r was positive in the epithelial cells, and endothelial cells of groups b and group c while group a showed a negative expression in the epithelial cells and weak expression in endothelial cells, at 20 and 30 days of healing periods the igf1r was highly expressed in endothelial cells , adipose cells , while moderately expressed on osteoblasts (groups b and c), while in group a there was a weak positive expression on endothelial cells and negative expression on osteoblasts and osteocytes. also the results showed that there was a significant difference in positive cell expression in rabbits of group band c at all healing periods when compared with rabbits of group a, the previous results are in agreement with markopoulos and katz et al ( 22 ) , the current study showed that the bmp-4 has a positive expression on osteoblasts and osteocytes ranging from intensely stained ( at 10, 20 days of healing periods) to moderately stained ( at 30 days of healing period) depending on the numbers of these cells in all groups , this result is in agreements with jason et al. whom evaluated the expression patterns of several members of the bmp family (2,4, and 7) in bone defect which was made in a mandible of 28 rats and studied the healing process after 1,2,3, and 4 weeks . they found that the bmp-4 had a strong positive expression on osteoblasts,osteocytes and osteoclasts at 2 and 3 weeks of healing periods, while the immunostaining of bmp-4 protein return to moderate expression at 4 weeks of healing period which was coincided with the histological appearance of mature lamellar bone (23) . references 1. akbarzadeh a, norouzian d, mehrabi mr, jamshidi s, farhangi a, allah a, mofidian s, lame rad b induction of diabetes by streptozotocin in rats. ijcb 2007; 22: 60-64. 2. brosky g, logothetopoulos j. alloxan diabetes in the mouse and guinea pig. diabetes 8. diabetes 1999; 60611. 3. ikebukuro k, adachi y, yamada y, fujimoto s, seino y, oyaizu h.treatment of alloxan-induced diabetes mellitus by transplantation of islet cells plus bone marrow cells via portal vein in rabbits. transplantation 2002; 73(4):518. 4. calhoun jh, laforte aj, yin s. osteogenic protein-1 (bone morphogenetic protein-7) in the treatment of tibial nonunions. j bone joint surg am 2001; 83: suppl 1:s151-8. 5. street j, bao m, deguzman l, bunting s, peale fv jr, ferrara n, steinmetz h, hoeffel j, cleland jl, daugherty a, van bruggen n, redmond hp, carano ra, filvaroff eh. vascular endothelial growth factor stimulates bone repair by promoting angiogenesis and j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of oral diagnosis 95 bone turnover. proc natl acad sci usa 2002: 99: 9656–9661. 6. schneir m, ramamurthy n, golub l. skin collagen metabolism in the streptozotocin-induced diabetic rat: enhanced catabolism of collagen formed before and during the diabetic state. diabetes 1982; 3: 1:426. 7. cooley bc, hanel dp, anderson rb. the influence of diabetes on free flap transfer: i. flap survival and microvascular healing. ann plast surg 1992; 29-58. 8. devlin h, garland h, sloan p, tang n. healing of tooth extraction sockets in diabetic animals. j oral maxillofac surg 1996; 54(9):1087-91. 9. lalani zs. characterization of healing tissue in a tooth extraction socket in a rabbit model. texas medical center dissertations (via proquest). paper aai3034645. 10. evian ci, rosenberg es, coslet jg, corn h. 2008; 231237 11. lalani z, wong m, brey em, mikos ag, duke pj. spatial and temporal localization of transforming growth factorbeta, bone morphogenetic protein-2, and vascular endothelial growth factor in healing tooth extraction sockets in a rabbit model. j oral maxillofac surg 2003; 61: 1061. 12. peng y, kang q, cheng h, et al. transcriptional characterization of bone morphogenetic proteins (bmps)-mediated osteogenic signaling. j cell biochem 2003; 90:1149–1165. 13. anapole f, muhl z, fuller j. the force velocity relations of the rabbit digastrics muscle. arch oral biol 1987; 32: 93-99. 14. yamane a, fukui t, chiba m. in vitro measurement of orthodontic tooth movement in rabbits given aminopropionitrile or hydrocortisone using a time lapse videotape recorder. eur j orthod 1997; 8:19-21. 15. zhao gq. consequences of knocking out bmp signaling in the mouse. genesis 2003; 35:43–56. 16. mundy gr. regulation of bone formation by bone morphogenetic proteins and other growth factors. clin orthopead rel res 1996; 324: 24-28. 17. bikle, d.d. integrins, insulin like growth factors, and the skeletal response to load. osteoporos int 2008; 19: 9: 1237-46. 18. chen tl, bates rl. recombinant human transforming growth factor beta 3 modulates bone remodeling in a mineralizing bone organ culture. j bone miner res 1993; 8: 423. 19. luu h, kraut d, graves d, gerstenfled l. diabetes interferes with the bone formation by affecting the expression of transcription factors that regulate the osteoblasts differentiation. endocrinology 2003; 144:352-64. 20. spinella-jaegle s, roman-roman s, faucheu c, dunn fw, kawai s, gallea s, stiot v, blanchet am, courtois b, baron r, rawadi g. opposite effects of bone morphogenetic protein-2 and transforming growth factor-beta1 on osteoblast differentiation. bone 2001; 29: 323. 21. cross mj, claesson-welsh l. fgf and vegf function in angiogenesis: signalling pathways, biological responses and therapeutic inhibition. trends pharmacol sci 2001; 22: 201-7. 22. markopoulos ak, poulopoulos ak, kayavis i, papanayotou p. immunohistochemical detection of insulin-like growth factor-i in the labial salivary glands of patients with sjogren's syndrome. oral dis 2000; jan: 6(1):31-4. 23. spector ja, luchs js, mehrara bj, greenwald ja, smith lp, longaker mt. expression of bone morphogenetic proteins during membranous bone healing. plast recostr surg 2001; 107: 124-134. hasan.doc j bagh college dentistry vol. 27(1), march 2015 evaluation of the pedodontics, orthodontics and preventive dentistry 164 evaluation of the relationship between curve of spee and dentofacial morphology in different skeletal patterns hasan jameel kazem al-amiri, b.d.s. (1) dhiaa jaafar n. al-dabagh, b.d.s., m.sc. (2) abstract background: curve of spee (cs) is an anteroposterior anatomical curve established by the occlusal alignment of the teeth viewed in the sagittal plane. this occlusal curvature has clinical importance in orthodontics and other fields of dentistry. this study aimed to evaluate the relationship between the cs and dentofacial morphology of different skeletal patterns in both genders. materials and methods: eighty six iraqi arab subjects (44females,42 males ) their age ranged from 17 -30 years, classified into: skeletal i with normal occlusion(15 females and 15 males), skeletal ii with ci ii div 1 malocclusion (15 females and 15 males) and skeletal iii with ci iii malocclusion (14 females and 12 males). forty one variables measured using direct dental cast measurements , dental cast photographs and cephalometric radiographs with the aid of autocad program version 15 (2006). results: no significant differences in the cs depth between males and females or between right and left sides in both arches of different skeletal patterns. no significant differences in the maxillary cs among the 3 skeletal patterns, the mandibular cs in ci ii div 1 malocclusion was larger than normal occlusion and ci iii malocclusion. maxillary cs significantly correlated to arch length, inter canine distance and inter second premolar distance in normal occlusion and overbite in cl iii malocclusion. mandibular cs significantly correlated with overbite and overjet in cl ii div 1 and cl iii malocclusions. conclusions: cs was not influence by sides and gender in both arches of different skeletal patterns. cs was concave in the mandibular arch with the maximum concavity at the mesio-buccal cusp tip of the mandibular first molar and convex in the maxillary arch with the maximum convexity at the buccal cusp tip of the maxillary second premolar, in different skeletal patterns. key words: curve of spee, arch length, overbite, overjet, dentofacial morphology. (j bagh coll dentistry 2015; 27(1):164-168). introduction the curve of spee was described firstly in 1890 by f. graf von spee, a german anatomist (1855-1937), who used skulls with abraded teeth to define the line of occlusion as the line on a cylinder tangent to the anterior border of the condyle, the occlusal surface of the second molar, and the incisal edges of the mandibular incisors(1). spee located the center of this cylinder in the midorbital plane so that it had a radius of 6.5 to 7.0 cm.(2).the curve of spee depth is minimal in the deciduous dentition, it increases to maximum depth with eruption of the permanent second molars and then remained relatively stable into late adolescence and early adulthood (3). the functional significance of the curve of spee depth has not been completely understood (4). however, it had been suggested that it had a biomechanical function during food processing by increasing the crush-shear ratio between the posterior teeth and the efficiency of occlusal forces during mastication (5). an increased curve of spee was seen in brachycephalic facial patterns (6) and associated with short mandibular bodies (7). the curve of spee was influenced by the ratio between posterior and anterior facial heights (4). (1) master student. department of orthodontics, college of dentistry, university of baghdad (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad certain cephalometric and dental factors were associated with individual variations in the curve of spee (8). little information's were found regarding the curve of spee in different skeletal patterns in iraqis, specially by using computerized method of assessment, so it is intended to implement this study to establish a baseline data regarding: 1. the features of the curve of spee in different skeletal patterns in iraqis. 2. gender difference of the curve of spee in different skeletal patterns. 3. the relations between the curve of spee and dentofacial morphology. materials and methods fifty females and forty six males of iraqi arab subjects with an age range between 17 30 years and full permanent teeth excluding the third molars were selected from college of dentistry, baghdad university after clinically examining 312 subjects (152 females, 160 males) because of the following exclusion criteria: cast restoration or cuspal coverage, tmj disorder (9), severe craniofacial disorders (10), previous orthodontic, orthopedic or facial surgical treatments(11), active periodontal diseases (1),supernumerary tooth or teeth, transposition of teeth, microdontia and/or macrodontia and history of systemic diseases. j bagh college dentistry vol. 27(1), march 2015 evaluation of the pedodontics, orthodontics and preventive dentistry 165 the following records were taken for every subject included in this study: 1dental casts (86 pairs of dental casts). 2three photographs for every dental cast (occlusal, left side and right side for upper and lower dental cast photographs). 3 eighty six digital lateral cephalometric radiographs. the sample sub divided into:-skeletal i with normal occlusion, skeletal ii with cl ii div 1 malocclusion and skeletal iii with cl iii malocclusion. each subject was clinically examined (intraorally and extraorally) to check his/her fulfillment of the required criteria. impression of the dental arches was taken before taking lateral cephalometric radiograph. each dental cast would be numbered on the artistic portion on the left side, right side and occlusal view to be ready for photograph. then cephalometric radiograph was taken under rigidly standardized conditions using dimax3 digital x-ray unit system machine. the standardization of the dental casts photographs that was used in this study was similar to the standardization method used by saadi (13). once the picture of the photographs and radiographs imported to the autocad program, it would be divided by scale for each picture to overcome the magnification. linear and angular measurements would be obtained by using the autocad measuring tools, on the lateral view the occlusal plane was determined, then perpendicular distances from the occlusal plane to the buccal cusp tip of each lateral tooth were measured. cs of the particular dental arch was determined by taking the average of the points located at the maximum concavity in the lower arch (below occlusal plane) with its contralateral tooth and the points located at the maximum convexity in the upper arch (above occlusal plane) with its contralateral tooth, while on the occlusal view inter canine distance (icd), inter second premolar distance (ispd), inter first molar distance (ifmd), inter second molar distance (ismd) and arch length (al) were measured. the overbite and overjet were directly measured on the study cast using dental vernier (14). cephalometric skeletal and dental measurements used in this study were frankfort mandibular plane angle, anb angle, gonial angle, inter incisal angle, incisor mandibular plane angle, lower anterior facial height and posterior facial height. data of the sample were subjected to computerized statistical analysis using spss version 15 (2006) computer program. descriptive statistics included mean values and standard deviations. inferential statistics included paired ttest, independentsamples t-test, analysis of variance (anova) test, least significant difference (lsd test) and pearson’s correlation coefficient (r) were done. results table1 showed the descriptive statistics (means and standard deviations) and side differences for the depth of each lateral tooth relative to occlusal plane in cl i, cl ii and cl iii respectively. statistically no significant side difference was found in both arches. table1: depth of each lateral tooth relative to occlusal plane teeth no. side (d. f. = 28) ci i ci ii (d. f. = 28) ci iii (d. f. = 24) descriptive statistics side difference descriptive statistics side difference descriptive statistics side difference mean s.d. t-test p-value mean s.d. t-test p-value mean s.d. t-test p-value upper 2 l -0.02 0.61 0.22 0.824 (ns) 0.53 0.94 0.32 0.748 (ns) 0.09 1.10 -1.51 0.143 (ns) r -0.04 0.66 0.46 1.48 0.43 0.91 upper 3 l 1.34 0.89 0.46 0.650 (ns) 2.01 1.62 1.71 0.097 (ns) 1.17 1.54 1.67 0.108 (ns) r 1.28 0.89 1.70 2.04 0.43 2.05 upper 4 l 2.08 0.96 0.97 0.340 (ns) 2.52 1.30 1.70 0.100 (ns) 2.18 0.92 0.91 0.370 (ns) r 1.94 1.14 2.30 1.35 1.98 1.40 upper 5 l 2.13 0.93 1.04 0.305 (ns) 2.64 1.35 1.42 0.165 (ns) 2.33 1.02 -0.03 0.973 (ns) r 1.96 1.10 2.37 1.22 2.32 1.34 upper 6 l 1.69 0.80 0.39 0.6991 (ns) 2.05 1.28 1.12 0.270 (ns) 1.94 0.89 0.93 0.363 (ns) r 1.63 0.86 1.86 1.07 1.75 1.18 lower 2 l 0.51 0.36 0.64 0.527 (ns) 0.28 0.62 -1.00 0.324 (ns) 0.33 0.70 -1.02 0.319 (ns) r 0.45 0.51 0.40 0.68 0.45 0.59 lower 3 l 0.66 0.70 -0.83 0.416 (ns) 0.40 1.12 -0.78 0.440 (ns) 0.73 0.92 -1.00 0.327 (ns) r 0.77 0.81 0.50 1.22 0.91 0.96 lower 4 l -0.43 0.79 -1.31 0.201 (ns) -0.78 1.41 -1.44 0.160 (ns) -0.09 1.31 -1.46 0.156 (ns) r -0.25 0.83 -0.56 1.55 0.20 1.07 lower 5 l -1.03 0.96 -0.78 0.441 (ns) -1.50 1.19 -1.24 0.224 (ns) -0.79 1.20 -1.17 0.254 (ns) r -0.94 1.06 -1.25 1.62 -0.52 1.19 lower 6 l -1.57 0.83 -0.54 0.596 (ns) -1.76 1.02 -1.61 0.119 (ns) -1.08 1.05 -1.93 0.065 (ns) r -1.50 1.09 -1.57 1.30 -0.73 0.88 all measurements are in millimeters, l: left side, r: right side, t-test: paired t-test, ns: none significant p-value > 0.05. j bagh college dentistry vol. 27(1), march 2015 evaluation of the pedodontics, orthodontics and preventive dentistry 166 table 2 showed the descriptive statistics and gender difference of the cs in cl i, cl ii and cl iii respectively, however (t-test and p-value) showed no significant gender differences in both arches in all 3 classes. table 2: gender difference of the mean depth of contra-lateral teeth relative to occlusal plane. teeth gender females 15 males d.f.=28 15 ci i ci ii 15 females 15 males d.f.=28 ci iii 14 females 12 males d.f.=24 mean s.d. t-test p-value mean s.d. t-test p-value mean s.d. t-test p-value upper 2 males 0.01 0.66 0.580 0.564 (ns) 0.53 1.14 0.551 0.584 (ns) 0 1.24 -1.765 0.084 (ns) females -0.08 0.61 0.35 1.37 0.48 0.72 upper 3 males 1.46 0.81 1.270 0.209 (ns) 2.33 1.67 1.595 0.116 (ns) 0.94 1.75 0.483 0.631 (ns) females 1.17 0.94 1.66 1.62 0.69 1.93 upper 4 males 2.06 0.99 0.412 0.682 (ns) 2.33 1.61 0.112 0.912 (ns) 1.85 1.03 -1.295 0.201 (ns) females 1.95 1.12 2.29 1.09 2.27 1.27 upper 5 males 2.01 0.98 -0.256 0.799 (ns) 2.23 1.42 -1.655 0.103 (ns) 2.24 1.01 -1.663 0.103 (ns) females 2.08 1.06 2.78 1.09 2.71 1.01 upper 6 males 1.62 0.82 -0.403 0.688 (ns) 1.91 1.26 -0.278 0.782 (ns) 1.74 0.73 -1.6 0.116 (ns) females 1.70 0.85 2.00 1.10 2.16 1.10 lower 2 males 0.58 0.39 1.740 0.087 (ns) 0.18 0.73 -1.978 0.053 (ns) 0.46 0.41 0.649 0.519 (ns) females 0.38 0.47 0.50 0.51 0.36 0.71 lower 3 males 0.79 0.71 1.720 0.091 (ns) 0.17 1.51 -1.492 0.141 (ns) 0.80 0.92 -0.176 0.861 (ns) females 0.50 0.65 0.66 0.97 0.84 0.97 lower 4 males 0.08 1 1.526 0.132 (ns) -0.89 1.48 -1.898 0.063 (ns) -0.14 1.23 -1.093 0.280 (ns) females -0.30 0.96 -0.16 1.52 0.22 1.15 lower 5 males -0.68 0.95 1.793 0.078 (ns) -1.44 1.36 -0.709 0.481 (ns) -0.84 1.22 -1.042 0.302 (ns) females -1.15 1.06 -1.18 1.57 -0.50 1.16 lower 6 males -0.99 0.97 1.101 0.275 (ns) -1.43 1.22 0.234 0.815 (ns) -1.09 1.18 -1.233 0.223 (ns) females -1.34 1.44 -1.50 1.33 -0.75 0.76 all measurements are in millimeters, t-test: independent samples t-test, ns: none significant p-value > 0.05. table 3 showed the descriptive statistics and classes difference for the maxillary and mandibular cs among the 3 classes. the maxillary cs had larger value than the mandibular cs in all 3 classes. the mean value of the maxillary cs was largest in ci ii div 1 malocclusion and smallest in normal occlusion. while, the mean value of the mandibular cs was largest in ci ii div 1 malocclusion and smallest in ci iii malocclusion. table 3: comparison among classes regarding curve of spee and depth of the teeth relative to occlusal plane. arches classes descriptive statistics classes' differences anova lsd mean s.d. f-test p-value i-ii i-iii ii-iii maxillary cs i 2.14 0.79 1.857 0.163 (ns) ii 2.58 1.22 iii 2.57 0.97 mandibular cs i -1.15 1.27 3.138 0.049 (s) 0.041 (s) 0.815 (ns) 0.028 (s) ii -1.80 1.37 iii -1.08 0.84 all measurements are in millimeters, cs: curve of spee, s: significant, hs: highly significant, ns: none significant. table 4 showed the pearson's correlation coefficient factor and pvalue among the maxillary and mandibular cs with the other measured variables in the 3 skeletal classes. discussion in this study attempt was made to separate the sample according to gender, skeletal patterns and select a limited range of age to evaluate the variables more precisely. data obtained in this study showed no significant gender and side differences in the mean of the mandibular cs depth that agreed with the results of currim and wadkar (15). no significant gender difference in the maxillary cs depth that agreed with the result of cheon et al. (9). there was no significant side difference in the maxillary cs depth that disagreed with the result of cheon et al. (9) possibly due to racial difference or the sample of a right handed subjects. data showed an upward concave cs relative to occlusal plane in the mandibular arch that was agreed with garcia (16) and a downward convex cs relative to occlusal plane in the maxillary arch that was agreed with the result of shannon and nanda(9). j bagh college dentistry vol. 27(1), march 2015 evaluation of the pedodontics, orthodontics and preventive dentistry 167 the present findings showed that, the maximum concavity in the mandibular cs was the mesio-buccal cusp tip of the first molar that was agreed with the results of ferrario et al. (17) but disagreed with koyoma (18) who found that the deepest point of the cs in the mandibular arch was in the second premolar. the buccal cusp tip of the maxillary second premolar was the maximum convexity in the maxillary cs, agreed with cheon et al. (9). the convexity of the maxillary cs was larger relative to occlusal plane than the concavity of the mandibular cs in all 3 classes that was agreed with cheon et al.(9) but, in contrast to the result of xu et al. (19) who determined anterior point of the maxillary cs from the tip of the canine. the mandibular curve of spee in skeletal ci ii was significantly deeper when compared with skeletal ci i and skeletal ci iii subjects, that was agreed with shannon and nanda (8). however, no significant differences in the depth of the cs between skeletal ci i and skeletal ci iii. table 4: correlations between the curve of spee and the measured variables variables pearson’s correlation coefficient class i class ii class iii maxillary cs mandibular cs maxillary cs mandibular cs maxillary cs mandibular cs upper lal r 0.461 0.325 0.317 0.278 0.267 0.213 p-value 0.010 (hs) 0.080 (ns) 0.087 (ns) 0.136 (ns) 0.187 (ns) 0.296 (ns) upper ral r 0.406 0.349 0.306 -0.351 0.360 0.047 p-value 0.026 (s) 0.059 (ns) 0.100 (ns) 0.057 (ns) 0.071 (ns) 0.820 (ns) upper icd r 0.540 0.217 0.083 0.015 0.209 0.113 p-value 0.002 (hs) 0.250 (ns) 0.664 (ns) 0.937 (ns) 0.306 (ns) 0.582 (ns) upper ispd r 0.389 0.240 0.044 0.253 -0.227 0.093 p-value 0.034 (s) 0.201 (ns) 0.819 (ns) 0.177 (ns) 0.265 (ns) 0.650 (ns) upper ifmd r 0.353 0.130 0.168 0.086 0.325 0.102 p-value 0.056 (ns) 0.493 (ns) 0.375 (ns) 0.651 (ns) 0.105 (ns) 0.621 (ns) upper ismd r 0.347 0.008 0.047 0.049 0.142 0.168 p-value 0.060 (ns) 0.967 (ns) 0.804 (ns) 0.799 (ns) 0.490 (ns) 0.412 (ns) lower icd r 0.203 0.224 0.132 0.015 0.079 0.416 p-value 0.282 (ns) 0.235 (ns) 0.488 (ns) 0.939 (ns) 0.702 (ns) 0.035 (s) lower ispd r 0.089 0.184 0.052 0.092 0.023 0.149 p-value 0.641 (ns) 0.330 (ns) 0.784 (ns) 0.628 (ns) 0.912 (ns) 0.469 (ns) lower ifmd r 0.235 -0.145 0.024 0.213 0.129 0.039 p-value 0.212 (ns) 0.444 (ns) 0.899 (ns) 0.259 (ns) 0.531 (ns) 0.851 (ns) lower ismd r 0.253 0.059 0.012 0.066 0.239 0.097 p-value 0.177 (ns) 0.757 (ns) 0.949 (ns) 0.730 (ns) 0.239 (ns) 0.639 (ns) lower lal r 0.292 0.406 0.169 -0.194 -0.316 0.175 p-value 0.118 (ns) 0.026 (s) 0.373 (ns) 0.304 (ns) 0.116 (ns) 0.394 (ns) lower ral r 0.302 0.342 0.253 -0.282 0 0.084 p-value 0.105 (ns) 0.064 (ns) 0.178 (ns) 0.130 (ns) 1 (ns) 0.683 (ns) fma r 0.085 -0.041 0.520 0.087 -0.001 -0.174 p-value 0.656 (ns) 0.828 (ns) 0.003 (hs) 0.646 (ns) 0.995 (ns) 0.395 (ns) anb r 0.186 0.139 0.204 0.268 0.231 0.203 p-value 0.326 (ns) 0.464 (ns) 0.279 (ns) 0.152 (ns) 0.256 (ns) 0.320 (ns) ga r 0.054 0.168 0.334 0.097 0.193 0.087 p-value 0.775 (ns) 0.375 (ns) 0.072 (ns) 0.609 (ns) 0.344 (ns) 0.673 (ns) iia r 0.222 0.169 0.337 0.121 0.122 0.093 p-value 0.238 (ns) 0.371 (ns) 0.069 (ns) 0.524 (ns) 0.553 (ns) 0.652 (ns) impa r -0.152 -0.075 -0.367 -0.094 0.140 0.423 p-value 0.422 (ns) 0.695 (ns) 0.046 (s) 0.622 (ns) 0.496 (ns) 0.031 (s) lafh r 0.041 0 0.196 -0.039 -0.120 -0.012 p-value 0.829 (ns) 0.998 (ns) 0.300 (ns) 0.839 (ns) 0.558 (ns) 0.955 (ns) pfh r 0.320 0.090 0.248 0.065 0.372 0.184 p-value 0.085 (ns) 0.636 (ns) 0.187 (ns) 0.735 (ns) 0.061 (ns) 0.368 (ns) overbite r 0.046 0.154 0.259 0.673 0.527 0.664 p-value 0.810 (ns) 0.415 (ns) 0.167 (ns) 0.000 (hs) 0.006 (hs) 0.000 (hs) overjet r 0.263 0.210 0.030 0.565 0.208 0.391 p-value 0.160 (ns) 0.266 (ns) 0.873 (ns) 0.001 (hs) 0.308 (ns) 0.048 (s) lal: left arch length, ral :right arch length ns: none significant, s: significant, hs: high significant,(r):pearson’scorrelation coefficient. no significant differences in the depth of the maxillary cs among the 3 skeletal classes, possibly because of the high variability in incisors positions relation of maxillary and mandibular relationships , that was agreed with shannon and nanda(8). significant correlation was found between fma and cs depth in skeletal ci ii, that came in agreement with shannon and nanda (8). the cs had no significant correlation with ga, lafh and pfh , that agreed with cheon et j bagh college dentistry vol. 27(1), march 2015 evaluation of the pedodontics, orthodontics and preventive dentistry 168 al.(9) but disagreed with farella et al.(4) who found that the cs was more marked in short-face subjects and less marked in long-face subjects because in this study generally, the sample was of a normal or long face type. there were statistically high significant correlation between cs and overbite and overjet in skeletal ci ii and skeletal ci iii which agreed with the results of baydas et al. (10). the anb angle had no significant correlation to the cs this was agreed with the result of shannon and nanda(8)and disagreed with cheon et al. (9) possibly because of the great variations in incisor positions, irrelative to maxillary and mandibular relationships. it was clear that the cs was influence more by dental factors than skeletal factors so, it is preferable to evaluate the cs in relations to soft tissues and biting force. references 1. kumar kp, tamizharasi s. significance of curve of spee: an orthodontic review. j pharm bioallied sci 2012; 4(suppl 2): s323-8. 2. spee fg, beidenbach ma, hotz m, hitchcock hp. the gliding path of the mandible along the skull. j am dent assoc 1980;100(5): 670-5. 3. marshall sd, caspersen m, hardinger rr, franciscus rg, aquilino sa, southard te. development of the curve of spee. am j orthod dentofacial orthop 2008; 134(3): 344-352. (ivsl). 4. farella m, michelotti a, van eijden tm, martina r. the curve of spee and craniofacial morphology: a multiple regression analysis. eur j oral sci 2002; 110(4):277-81. 5. osborn jw. relationship between the mandibular condyle and the occlusal plane during hominid evalution:some of its effects on jaw mechanics. am j phys anthropol1987; 73(2):193-207. 6. wylie wl. overbite and vertical facial dimensions in terms of muscle balance. angle orthod j. 1994; 14(1):13-7. (ivsl). 7. salem oh, al-sehaibany f, preston cb. aspects of mandibular morphology, with specific reference to the antegonial notch and the curve of sٍpee. j clin pediatr dent 2003; 27(3):261-5. 8. shannon kr, nanda r. changes in the curve of spee with treatment and at 2 years posttreatment. am j orthod dentofacial orthop 2004; 125(5):589-96. 9. cheon sh, park yh, paik ks, ahn sj, hayashi k, yi wj, lee sp. relationship between the curve of spee and dentofacial morphology evaluated with a 3dimentional reconstruction method in korean adults. am j orthod dentofacial orthop 2008;133: 640. (ivsl). 10. baydas b, yavuz i, atasarl n, ceylan t, dagsuyu i. investigation of the changes in the positions of upper and lower incisors, overjet, overbite, and irregularity index in subjects with different depths of curve of spee. angle orthod 2004; 74(3):349-55. (ivsl). 11. peck s, peck l, kataja m. the gingival smile line. angle orthod 1992; 62(2): 91-100. (ivsl). 12. krishnan v, daniel st, lazar d, asok a. characterization of posed smile by using visual analog scale, smile arc, buccal corridor measures, and modified smile index. am j orthod dentofacial orthop 2008; 133(4): 515-23. (ivsl). 13. saadi z. the effect of nutritional status on dental health, salivary physicochemical characteristics and odontometric measurements among five years old kindergarten children and fifteen years old students ph. d. thesis. baghdad universityiraq, 2010. 14. draker hl. handicapping labiolingual deviations proposed for public health purpose. am j orthod 1960; 46(4):295-305. 15. currim s, wadkar pv. objective assessment of occlusal and coronal characteristics of untreated normals: a measurement study. am j orthod dentofacial orthop 2004; 125(5): 582-8. 16. garcia r. leveling the curve of spee: a new prediction formula. j charles h. tweed int found 1985; 13:65-72. 17. ferrario vf, sforza c, miani a. statistical evaluation of monson’s sphere in healthy permanent dentitions in man. arch oral biol 1997; 42(5):365-9. 18. koyama t. comparative analysis of the curve of spee (lateral aspect) before and after orthodontic treatmentwith particular reference to overbite patients. j nihon univ sch dent 1979; 21(1-4): 25-34. 19. xu h, suzuki t, muronoi m, ooya k. an evaluation of the curve of spee in the maxilla and mandible of human permanent healthy dentitions. j prosthet dent 2004; 92(6):536-9. لخالصةا األسنان تقویم في سریریھ أھمیة لھ اإلطباق في نحناءاال ھذا. السھمي المستوى في ویظھر األسنان إطباق بمحاذاة ینشأ , خلفي أمامي تشریحي منحني ھو سبي منحنى :الخلفیة السني بالتشكل وعالقتھ سبي منحنى تقییم إلى الدراسة ھذه ھدفت . معالجتھ تمی مریض كل في تقریبا سبي منحنى مع یتعاملون األسنان تقویم أطباء .األخرى األسنان طب مجاالتو و األسنان لصور قیاساتو ؛ األسنان إلطباق مباشرة قیاسات باستخدام مختلفة أسالیب في المتغیرات من) 41( قیاس طریق عن الجنسین كال في العظمي الھیكل مختلفة نماطأل ألوجھي .2006 نسخة أوتوكاد امجبرن بمساعدة الرأس أشعة : التالي النحو على تصنف ، سنة 3017 بین أعمارھم تراوحت) 44= اإلناث ،42= الذكور( العرب العراقیین من شخص" 86" من الدراسة عینة تكونت :العینة و المواد 15 و إناث 15( األسنان اإلطباق سوء 1 شعبة الثانیة الدرجة مع الثاني الصنف العظمي كلالھی ،) ذكور 15 و إناث 15( الطبیعي األسنان إطباق مع األول الصنف العظمي الھیكل ) .ذكور 12 و إناث 14( األسنان اإلطباق سوء الثالثة الدرجة مع الثالث الصنف العظمي الھیكل و) ذكور للبیانات اإلحصائي التحلیل باستخدام سبي منحنى كان .المختلفة العظمي الھیكل أنماط من الفكین كال في األیسر و األیمن الجانبین بین أو واإلناث الذكور بین سبي منحنى عمق في إحصائیة داللة ذات فروق توجد ال :النتائج من الشدق أعتاب طرف في بتحد أقصى مع العلوي الفك قوس في محدبةو السفلي لفكل األولى الرحى من شدقي إنسي أعتاب طرف في التقعر أقصى مع السفلي الفك قوس في مقعرة .المختلفة العظمي الھیكل أنماط ،في العلوي لفكل الثاني الضاحك سوء 1 شعبة الثانیة الدرجة في السفلي الفك في سبي منحنى كان ، حین في الثالثة العظمي الھیكل أنماط بین من العلوي لفكل سبي منحنى في إحصائیة داللة ذات فروق توجد ال سوء الثالثة الدرجة و الطبیعي األسنان إطباق بین السفلي الفك في سبي منحنى في كبیر فرق یوجد ال. اإلطباق سوء الثالثة الدرجة و الطبیعي األسنان إطباق من بالمقابلة رأكب اإلطباق . اإلطباق الدرجة في العضة تراكب و الطبیعي، اإلطباق في الثاني الضاحك و النابین بین العرضیة والمسافة العلوي القوس طول معكبیر بشكل مترابط العلوي الفك في سبي منحنى :االستنتاجات سوء 1 شعبة الثانیة الدرجة في ، بینما. الثالث الدرجة اإلطباق سوء و الطبیعي اإلطباق في العضة تراكب معكبیر بشكل مترابط السفلي الفك في سبي منحنى .اإلطباق سوء الثالث . العضة وتراكب بروز األسنان مع سبي منحنى بین كبیر ارتباط ھناك كان اإلطباق inas.doc j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 58 clinicopathological analysis of oral squamous cell carcinoma in iraq during period (2001-2013) inas a. taha, b.d.s. (1) wasan h. younis, b.d.s., m.sc., ph.d. (2) abstract background: oral cancer is a highly lethal and disfiguring disease. squamous cell carcinoma of the oral cavity constitutes about 90% of all oral malignancies. the aims of the study was to achieve an epidemiological description of the oral squamous cell carcinoma in iraq in general and in iraqi governorates except kurdistan region retrospectively during period 2001-2013 materials and methods: data were collected from department of oral and maxillofacial pathology, college of dentistry, university of baghdad, nuclear medicine and radiotherapy hospital, iraqi cancer registry center, main hospitals in baghdad and iraqi governorates, private labs. for histopathological examinations. the descriptive and inferential statistical methods were used (frequency distributions, percentages, incidence rate, standardized ratio and relative risk) results: in iraq from 2001-2013, there were 1664 cases with overall m:f ratio (1.4 : 1). the most affected age group was (50-69 yrs), tongue was the most common affected site, grade ii was the most common, and the highest number of oscc was reported in baghdad governorate. a negative time trend was observed in the overall (crude) incidence rate of all registered oscc in iraq. conclusion: the incidence rate (crude rate) of oscc decreased in iraq from 2001 to 2013, and the standardized ratio showed that there is a decrease in tumor risk with advancing time. key words: oral squamous cell carcinoma, incidence rate, iraq. (j bagh coll dentistry 2015; 27(2):58-65). introduction squamous cell carcinoma (scc) of the oral cavity constitutes about 90% of all oral malignancies (1). the annual incidence and mortality rates vary between different races, genders, and age groups. world wide oc show high incidence in males more than females. (2,3) . an estimated 263,000 new oc cases were reported annually over the world which accounts 2.1% of all new cancers, for this reason, oc considered as a major health problem worldwide. (4). geographical and regional varieties with respect to oc incidence show that the sociocultural aspect of a population’s life style plays an important role in this disease (5). in the united states, approximately 22,000 new cases of oscc are diagnosed annually (6). in some industrialized countries, oc witnessed an increase. from 1990 to 1999, in the uk there was a statistical significance increase in ocs especially in lip cancer (2). on the other hand, other countries reported a decrease in oc like the usa, italy, hong kong, france, germany and australia (7) . the highest rates of oc have been reported in countries such as india, sri-lanka, south vietnam, the philippines, hong kong and taiwan (8), oc showed a high relative frequency among yemenis (9), oc is believed to be relatively rare amongst africans and 1.2% of all malignant lesions are oscc (10). (1)master student, department of oral diagnosis. college of dentistry, university of baghdad. (2)professor, department of oral diagnosis. college of dentistry, university of baghdad. several studies were carried out on the occurrence of oc in iraq, mainly retrospective in nature. in iraq, oc account for about 4.5% of all cancer cases according to iraqi cancer registry and scc represents about 91.5% of all oc and 37% of the head and neck cancer (11). during the period (1991-2000) in iraq, the incidence of ocs was unchanged (12). the commonest malignant lesions were oscc (56.1% ) (13). also in iraqi study during the period 2003-2006, the highest prevalence of oscc was observed in tongue 72 (55.81%) while the lowest prevalence was found in the floor of the mouth 5 (3.87%). the age groups 51–60 years were highly affected by scc 45(34.88%), baghdad governorate had the highest prevalence of oscc 53(41.08%) (14). from 2000 to 2008, there were 1787 new ocs registered in iraq, 1035 in men and 752 in women. oc accounted for approximately 2% of all cancers. scc was the most common oral malignancy accounting 90.92% for histopathological analysis from c00 to c06 (15). this research was attempted due to lack of dependable and documented data reporting oscc during the past years from 2001 to 2013 especially in iraqi governorates level. materials and methods cases of oscc in iraq and in iraqi governorates except kurdistan region were collected during the period (2001-2013) from the following centers after attaining the legal acceptances:department of oral and j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 59 maxillofacial pathology, college of dentistry, university of baghdad , nuclear medicine and radiotherapy hospital , iraqi cancer registry center at the ministry of health , main hospitals in baghdad and iraqi governorates , private labs. for histopathological examinations. the icd-o-10 coding system was used for reporting topographical information for lip (c00), tongue (c01&c02), gingival (c03), floor of the mouth (c04), palate (c05), other and unspecified parts of the mouth (c06). histopathological grading of oscc was: grade i (well differentiated), grade ii (moderately-well differentiated), grade iii (moderately-poor differentiated) and grade iv (poorly differentiated). a special patient case sheet was used for collecting the data. the descriptive and inferential statistical methods were used for the collected data (frequency distributions, percentages, incidence rate, standardized ratio and relative risk). results a total of 1664 cases (976 male and 688 female, m:f ratio (1.4 : 1) with a final histopathological diagnosis as oscc were recorded in iraq (except kurdistan region) during the period 2001-2013. the most affected age group was (50-69 yrs) (48.9%) in both men and women as in tables (1)&(2). according to the icd-10 the most common affected site was tongue (42.7%) and the highest percentage of oral subsite was reported in tongue –nos (not otherwise specified) (70%) followed by the lip (23%) as in table (3). the nos was the dominant and most commonly reported oral subsite in all oral sites from c00 to c06 according to icd-o10. scc of lip, tongue, floor of the mouth, palate and others and unspecified parts of the mouth were most common in men than in women as in table (4). the most common grade was grade ii which represented by (36.9%) as in table (5). the highest value of frequency distribution and percentage of oscc cases was reported in baghdad governorate (25.7%) and the lowest value was reported in al-muthana (1.2%) as in table (6). during (2001-2013) a negative time trend was observed in the overall (crude) incidence rate of all registered oscc in iraq in both males and females and by measuring the relative risk of male compared to female, the risk of oscc was always higher in male compared to female in all years studied as in table (7). the highest incidence rate and relative risk in age groups was found in (70+ yrs) in all years as in table (8) the highest incidence rate (1.23 per 100,000 per year) was found in al-basrah in 2006 followed by wasit (1.12 per 100,000 per year) in 2009. in baghdad, the highest ir (0.72 per 100,000 per year) in 2006 whereas in ninawa, the highest ir (0.67 per 100,000 per year) in 2004 as in fig. (1,2,3,4) .there was a decrease in the standardized ratio for each year that measure the risk of oscc with advancing time from 2001 to 2013 as in fig. (5) table 1: gender and age distribution for oscc cases gender n % male 976 58.7 female 688 41.3 total 1664 100 male to female ratio 1.4 : 1 age group n % <20 yrs 26 1.6 20-49 yrs 350 21 50-69 yrs 813 48.9 70+ yrs 475 28.5 total 1664 100 j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 60 table 2: gender distribution of oscc cases in relation to age. groups table 3: site distribution of oscc cases according to icd-10 table 4: gender distribution of oscc cases in relation to oral site according to icd-10 table 5: distribution of histopathological grading for oscc cases age group (years) gender m:f ratio male female n % n % <20 21 2.2 5 0.7 4.2 : 1 20-49 202 20.7 148 21.5 1.4 : 1 50-69 476 48.8 337 49 1.4 : 1 70+ 277 28.4 198 28.8 1.4 : 1 total 976 100 688 100 site icd code n % lip c00 382 23 tongue c01 & c02 711 42.7 gingiva c03 83 5 floor of the mouth c04 98 5.9 palate c05 72 4.3 other and unspecified parts of the mouth c06 318 19.1 total 1664 100 site icd code gender m : f ratio male female n % n % lip c00 248 25.4 134 19.5 1.9 : 1 tongue c01 & c02 410 42 301 43.8 1.4 : 1 gingiva c03 39 4 44 6.4 0.9 : 1 floor of the mouth c04 55 5.6 43 6.3 1.3 : 1 palate c05 50 5.1 22 3.2 2.3 : 1 other and unspecified parts of the mouth c06 174 17.8 144 20.9 1.2 : 1 total 976 100 688 100 histopathological grading n % grade i well differentiated 522 31.4 grade ii moderately –well differentiated 615 37 grade iii moderately poorly differentiated 195 11.7 grade iv – poorly differentiated 36 2.2 not stated (missing) 296 17.8 total 1664 100 j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 61 table 6: iraqi governorates distribution for oscc cases table 7: overall ir (crude) & gender specific yearly ir and relative risk of oscc (per 100,000/year) in iraq from 2001 to 2013. table 8: age specific yearly ir (per 100,000/year) and relative risk of oscc in iraq from 2001 to 2013. governorate n % baghdad 428 25.7 ninawa 178 10.7 al-basrah 173 10.4 babil 98 5.9 thi-qar 96 5.8 salah al-din 90 5.4 al-najaf 79 4.7 wasit 78 4.7 al-anbar 69 4.1 diyala 67 4 al-ta'mim 60 3.6 al-qadisiyah 57 3.4 karbala 42 2.5 maysan 42 2.5 al-muthanna 21 1.2 not stated (missing) 86 5.2 total 1664 100 ir of oscc (per 100,000/year) 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 crude rate (overall) 0.81 0.65 0.5 0.61 0.53 0.66 0.41 0.37 0.43 0.44 0.39 0.39 0.37 male 0.89 0.8 0.6 0.64 0.65 0.81 0.49 0.43 0.52 0.47 0.46 0.46 0.41 female 0.73 0.51 0.4 0.58 0.41 0.5 0.32 0.31 0.33 0.41 0.32 0.32 0.33 relative risk (rr) for male compared to female 1.2 1.6 1.5 1.1 1.6 1.6 1.5 1.4 1.6 1.1 1.4 1.4 1.2 age group (years) ir of oscc (per 100,000/year) 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 <20 0.02 0.02 0.01 0.02 0.02 0.03 0.02 0.01 0.01 0.02 0.01 0.01 0 20-49 0.53 0.26 0.31 0.35 0.29 0.37 0.29 0.26 0.27 0.19 0.2 0.22 0.16 50-69 5.66 4.65 3.46 4.33 3.67 4.03 2.49 2.41 2.73 2.71 2.18 2.28 2.21 70+ 11.15 12.14 7.77 9.12 8.19 12.14 6.12 5.27 7.31 7.78 6.15 6.31 7.11 rr for (50-69) compared to (20-49) 10.7 17.9 11.2 12.4 12.7 10.9 8.6 9.3 10.1 14.3 10.9 10.4 13.8 rr for 70+ compared to (20-49) 21 46.7 25.1 26.1 28.2 32.8 21.1 20.3 27.1 40.9 30.8 28.7 44.4 j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 62 figure 1 figure 2 figure 3 figure 4 figures 1-4: iraqi governorates specific yearly ir of oscc (per 100,000/year) figure 5: time trend for the age and gender standardized ratio using the year 2001 age and gender specific irs as a reference. discussion a negative time trend was observed in overall crude ir of all registered oscc in iraq from 2001-2013. our results reported that the frequency distribution and incidence of oscc declined during the study period. this observation was consistent with other studies (15,16) who reported that there was a decrease in count and incidence of oscc during their study periods (1999-2006), (2000-2008) respectively. while other study reported that oc occurrence for (10) years (1991-2000) was unchanged and constant (12). the standardized ratio was calculated to estimate the risk of oscc from 2001 to 2013 in iraq. it is evident that the standardized ratios are less than 1 with the recent years having a much smaller ratio than the older years indicating a decrease in tumor risk with advancing time. the incidence of oc varies widely around the world and data in some cases are difficult to interpret since cancer registrations using international agreed criteria based on the icd is comparatively recent. when the international data were observed, some countries had also reported a decrease in the incidence of oc like usa (17) italy, hong kong, germany (7). amongst africans, oc is believed to be relatively rare (10). conversely, the present results disagree with several epidemiological studies about oscc around the world that show a high incidence of oscc in brazil (18), in uk (19) as well as in indian j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 63 subcontinent, australia, france, yemen (6,9,20). possible reasons for the increase in incidence of oscc are tobacco and alcohol consumption, however in developed countries, both these cancer risk factors have shown a decrease, resulting in a decrease in oc incidence (8). this highlights the need for tobacco and alcohol consumption prevention programs and an early diagnosis of oc, which could impact the prevalence and incidence of this neoplasm. the negative time trend during (2001-2013) may be attributed to errors in collection of oc data in the providing resource, also in the past few years a considerable section of iraqi population preferred to seek medical care outside iraq (mainly in neighboring countries) therefore, such cases may not be included (15). besides that, according to iraqi ministry of migration and displacement, a considerable number of iraqi people migrated outside especially after 2003 war. in iraq, although oscc is a major problem, there is no complete registry of all cases of oscc. in this study the male were more affected than female with m:f ratio was (1.4 : 1) and this was compatible with the many international studies (2123) and with many iraqi studies (11-13,15,16,24,25) the difference in oc between men and women can be attributed to an increase in exposure of men to exogenous carcinogens. the variations in the contributions of smoking and alcohol were the possible causes of differences in oc between both genders. the most affected age group was (50-69 yrs) during the whole period from 2001-2013, this is in agreement with many of iraqi studies (12-16,25). also agreed with many international studies (21,22,26,27). the substantial increase of oscc cases in (50-69 yrs) age group can be explained by their lifestyle and the high exposure to carcinogenic factors like tobacco, alcohol and the professions. the age specific yearly ir was higher in age group (70+yrs), the explanation for these results, is the low iraqi population count in this age group that result in increase of their calculated ir when compared to the high population count of the age group (50-69 yrs). for the same mentioned reason , the relative risk of age group (70+yrs) was always higher than age group (50-69 yrs) when compared to age group (20-49 yrs). taking in consideration that the age group (< 20) was not used as a reference category in spite of their lowest count because it is unstable as a result of very small count of cases therefore the age group (20-49) was used as a reference. regarding to oral site, tongue scc was the first most common affected site. this is in agreement with many iraqi studies (14-16) and also agreed with other international studies (20,21,26,27). on the other side we disagreed with (11-13,24,25) who reported that the lip was the first affected site. tongue scc represents 30-40% of oc and is the most commonly observed oc into the oral cavity; traumatic lesions due sharp cusps or sharp edged teeth, by badly positioned teeth or by maladjusted dentures that chronically rub, leukoplakia and lichen planus are predominant precancerous conditions (28). tongue is also reported to be bathed in carcinogens mixed with saliva pool at the bottom of the mouth (29). in this study regarding the topographical information about oscc in all oral sites from c00 to c06 according to icd-o-10, the nos was the dominant and most commonly reported oral subsite. these results can be explained by the under-registration of tumor information about the oral subsite in the medical records, bad archiving and missing of some reports in patients files, poor application of icd coding system that used incorrectly by medical sub-staff in our health institutes. the grade ii had the highest percentage these results were in agreement with others (16,23,26). this disagreed with several studies (11,12,20,21) who reported that grade i was the most common grade. also disagreed with other research (30) who reported that grade iii was the most common grade. delayed detection of tumor is the underlying cause of advanced stages at the time of diagnosis (31).the differences among grading is attributed to the methods of data collection and the size of studied sample (32).in addition to that, the determination of grade of oscc is a subjective point and depend on the opinion of the histopathologist in his diagnosis and interpretation of the slide and this is may be an additional underlying cause for the high percentage of moderate differentiation. the highest value of frequency distribution and percentage of cases was reported in baghdad governorate. this is in agreement with all iraqi researches that studied the geographical distribution of oc (12,14,16). the high number of population can explain the underlying cause behind the highest percentages of oscc in baghdad among other iraqi governorates. also the presence of many centers and hospitals, the location of the institute and hospital of radiotherapy and nuclear medicine center in baghdad which made the referral cases reach the institute easier. regarding the ir according to geographical distribution, the highest ir was found in al-basrah. the explanations for this include a change in population composition and the high population of governorate lead to j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 64 decrease its ir, so the higher population of baghdad compared with al-basrah lead to shifting the ir of baghdad to be lower than albasrah. geographical and regional varieties with respect to oc incidence show that the sociocultural aspect of a population’s life style plays an important role (5). references 1. rapidis ad, gullane p, langdon jd, et al. major advances in the knowledge and understanding of the epidemiology, aetiopathogenesis, diagnosis, management and prognosis of oral cancer. oral oncol 2009; 45: 299-300. 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3: 75-83. http://www.ons.gov.uk/ons/rel/vsob1/cancer-statistics http://www.wales.nhs.uk/sites3/page.cfm?orgid=242& j bagh college dentistry vol. 27(2), june 2015 clinicopathological oral diagnosis 65 31. al-janabi as, sarkis sa. immunohistochemical expression of e-cadherin and cd44 adhesion molecules in oral squamous cell carcinoma. j bagh coll dentistry 2013; 25(1): 36-42. 32. al-qazzaz hh, sarkis sa. immunohistochemical expression of tgf-β in relation to invasion potential evaluated by mmp-2 in oral squamous cell carcinoma. j bagh coll dentistry 2012; 24(4): 62-6. الخالصة .عن طریق الفم م الخبیثةاألورا من جمیع %90یشكل حوالي الفمي الحرشفیة سرطان الخالیا .تشوھاتللغایة ومصحوب ب فتاك مرض ھو الفم سرطان: المقدمة -2001الفت رة خ الل كردس تان ع دا إقل یم العراقی ة المحافظ ات بش كل ع ام وف ي في العراق الفمي الحرشفیة سرطان الخالیال ابدیمیولوجي ھووصف أھداف الدراسة 2013 الع الج و مستش فى الط ب الن ووي ،جامع ة بغ داد /ط ب األس نان ی ة كل ،والوج ھ والفك ین الف م أم راض قس م :المراك ز التالی ة م ن البیان ات ت م جم ع :الط رق الم واد و األس الیب ت م اس تخدام . للفح ص النس یجي خاص ة ومختب رات العراقی ة والمحافظ ات ف ي بغ داد الرئیس یة المستش فیات , الس رطان العراق ي تس جیل اإلش عاعي ،مجل س ةاالستنتاجیو الوصفیة اإلحصائیة ، وك ان عاما 69-50 ھياألكثر اصابة الفئة العمریة ، وكانت )1:1.4( نسبة الذكور الى االناث ھي ،حالة 1664كانت ھناك ، 2013-2001 العراق من في :النتائج س جلت محافظ ة بغ داد أعل ى قیم ة م ن حی ث ) . التمی ز النس یجي الوس طي (أما درجة التمی ز النس یجي للس رطان األكث ر ش یوعا ھ ي ,األكثر اصابة الموقع اللسان ھو ف ي مع دل االص ابة بح االت بس رطان الخالی ا الحرش فیة انخف اض ل وحظ ) 2013-2001(خ الل . زیع والنسبة المئویة لحاالت سرطان الخالی ا الحرش فیة الفم ي التو .الفمي المسجلة في العراق م ع االص ابة بالس رطان خط ر انخف اض ف ي ھن اك انكم ا 2013-2001في العراق للفت رة انخفض معدل اإلصابة بسرطان الخالیا الحرشفیة الفمي إن :االستنتاج .الوقت تقدم العراق ،اإلصابة ي ، ومعدلالحرشفیة الفم سرطان الخالیا :الكلمات الرئیسیة j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 1 evaluation of the effect of surface treatments on shear bond strength between lithium disilicate ceramic and dentin. makdad chakmakchi , b.d.s., m.sc., ph.d., post doc (1) abstract purpose: to evaluate the effect of different surface treatments on shear bond strength between dentin and ips e.max lithium disilicate glass-ceramic. materials and methods: eighteen extracted third molars were embeded in epoxy resin. the tooth was sectioned vertically in mesiodistal direction using a low speed hard tissue microtome. the buccal and lingual surfaces of each section were ground flat using 600 grit silicone carbide paper. eighteen ceramic discs consisted of lithium disilicate glass-ceramic were prepared with a diameter of 4.7mm and height of 2.2mm. the discs were divided in two groups (n=10): (1) ips e.max treated with hydrofluoric acid and monobond plus (mbp) and (2) ips e.max treated with monobond etch &prime (mbep). the tooth was cemented with multilink automix and stored for 24hours at room temperature before thermocycling and subsequently loaded to failure in universal testing machine. failure mode were recorded for each specimen. result: bond strength analysis and t-test analysis mbep demonstrated the higher shear bond strength (sbs). mbp and mbep showed no statistically significant difference were found between them. one-way anova and t-test was used to determine differences in bond strength within and between the groups. cohesive failure in resin cement was predominant with higher results while adhesive and mixed with lower and equal. conclusion: surface treatment with monobond etch and prime has a favorable effect on sbs between dentin and lithium disilicate glass-ceramic with resin cement compared with monobond plus. keywords: lithium disilicate glass-ceramic, shear bond strength, monobond plus. (j bagh coll dentistry 2017; 29(3):18) introduction the increasing esthetic demands of conservative dentistry led to the launch of new materials and techniques. a major development in the field was the introduction of lithium disilicate ceramics a group of etchable glassceramics stronger than feldspathic porcelain, with exceptional esthetics that can establish a strong micromechanical bond with methacrylate based resin luting agents. in addition, by using methacrylate functionalized silane primers on the etched surface, chemical bonding is mediated with the methacrylate resin matrix of the luting agents (1,2). silanization transforms the hydrophilic etchedceramic surface to hydrophobic, promoting thus the wettability of the hydrophobic resin luting agent on the silane treated surface and improves bond strength in comparison with etched, but not silanated surfaces (3). bonded restorations have important advantages over conventionally cemented since they effectively reduce marginal defects and require cavity preparation with minimal removal of sound dental tissues (4). the standard procedure for bonding lithium disilicate ceramics involves two separate steps of ceramic surface treatment. the first step includes chemical etching with hydrofluoric acid (hf-acid), water rinsing, acid neutralization, water rinsing again and air drying. assisstant professor, conservative department, mosul.college of dentistry, university mosul. rinsing again and air drying. then follows the second step where the silane primer is applied, left intact and air-dried. to reduce the steps required for ceramic surface preparation, a new ceramic conditioning agent was introduced in early 2015 (monobond etch&prime ivocar vivadent ag), which integrates the etching and silane priming treatments in a single step. these materials shortened the treatment time of the clinical steps by etch and silanate glass-ceramic surfaces in one working step. furthermore, the technique sensitivity or inaccuracy of the pre-treatment of glass-ceramic restorations compared with conventional conditioning is reduced. etching the inner surface of the porcelain veneer with hydrofluoric acid creates a retentive etch pattern. sem of etched porcelain surface showed an amorphous micro-structure with numerous porosities (5,6,7,8,9). these micro-porosities increase the surface area for bonding and lead to a micro-mechanical interlocking of the resin cement. several factors like the etching time, concentration of the etching liquid, fabrication method of the porcelain restoration (10,11), and type of porcelain (12,13) determine the micro-morphology of the etch pattern and consequently the bond strength of the resin cement to the etched porcelain (14). multilink automix is used in combination with hf-acid and monobond plus or can be used in j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 2 combination with self-etching and self-curing multilink primer. this primer is responsible for establishing a strong adhesive bond to the tooth structure. the initiator contained in the primer permits chemically initiated polymerization (selfcuring), which is accelerated when the resin comes into contact with the primer. furthermore, the presence of a photo-initiator enables final polymerization with light. bonding of resin to dentine is based on resin infiltration into dentine tubules and bonding the collagen fibers of the dentine to form a hybrid layer. this layer is considered essential to create a strong and reliable bond between resin and dentine (15). therefore, the aim of this study is evaluating the shear bond strength of all ceramic with different surface treatment bonded to dentine using monobond plus or monobond etch & prime together with the multilink automix cement system and the bond failures. the null hypothesis was that monobond etch & prime would result in bond strength that is comparable with that of 5% hf acid etch and treated by monobond plus. materials and methods tooth preparation: extracted intact third molars, stored at 8 ◦c in tap water containing 0.5% sodium azide, were embed in epoxy resin, up to the cervical region. each tooth is sectioned vertically in mesiodistal direction using a low speed hard tissue microtome (isomet, buhler, evanstone, il, usa). the cutting was performed under water coolant. the buccal and lingual surfaces of each section were cut lat using 600 grit silicone carbide paper. the cutting surfaces were covered with an adhesive tape (50μm thick), providing holes (4mm diameter) located at the center of the specimens to standardize the bonding area. eighteen dentin specimens were prepared and randomly divided in two groups of nine specimens for each. the surfaces were thoroughly cleaned using the medium-grit paste (proxyt rda 36, ivoclar vivadent) indicated for the cleaning of cavities. preparation of lithium disilicate glass-ceramic discs: eighteen ceramic discs consisted of lithium disilicate glass-ceramic (ips e.max press, ivoclar-vivadent ag, schaan, liechtenstein) were prepared with a diameter of 4.7mm and height of 2.2mm according to (ss-en iso 6872:2015 (e)). the discs were divided in two groups (mbp, mbpe) and treated as follows: 1) mbp group acid etching was performed by 5% hf (ips ceramic etching gel, ivoclar vivadent ) for 30 seconds, residual acid were neutralized in powder for 60 seconds, then water-rinsed for 30 seconds and finally air-dried for10 seconds. silanization was performed by applying a silane agent with phosphate and disulphate monomers (monobond plus, ivoclar vivadent ) for 60 seconds followed by 10 seconds air drying. this treatment was used as the control group. 2) mbep group a new primer for simultaneous etching and silanization was used (monobond etch &prime, ivoclar vivadent). the ceramic surface was primed with the new agent by agitation with a microbrush for 20 seconds, the primer was allowed to react for 40 seconds, rinsed with water for 30 seconds and finally air-dried for 10 seconds. bonding of discs to the dentin: all treated discs were cemented to dentine using a resin luting agent (multilink automix, ivoclar vivadent). dentine specimens were treated with the corresponding primers and then the ceramic disks were bonded to dentin. to control the luting agent thickness, constant force of 15 n was applied for 1 mint. resin excess was removed and then light-cured from four directions for 20 seconds with a curing halogen device (heraeus translux®powerblue®, heraeus kulzer gmbh, hanau, germany), emitting1000 mw/cm2 light intensity. the curing time was set at 20 seconds for each of four directions 90◦ apart and finally for 60 seconds with the seating load removed and stored for 24 h at room temperature before thermocycling. artificial ageing – thermocycling (tc): all specimens were after water storage then subjected to thermal-cycling (tc) under the following conditions: 5000 cycles, 5°c/55°c, 1cycle/min, 20 seconds’ dwell time, 10 seconds’ transfer time. each cycle lasted 60 seconds. the specimens were subsequently loaded to failure under shear stress applied at the interface using a knife-edge loading head at a cross-head speed of 0.5 mm/min, until the ceramic disc was dislodged from the tooth. maximum load to failure was recorded in newton (n) for each sample and then shear bond strength was expressed in megapascals (mpa) by dividing the load at failure (newtons) by the bonded surface area. s=f max/a where: s= shear bond strength (mpa). f= load at failure (n). a= π r2. j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 3 the debonded ceramic surfaces were examined under a stereomicroscope lens (wild m3, wild heerbrugg, switzerland) at 6.4× magnification to assess the failure modes. the type of failures was classified as resin cohesive, adhesive (at the dentin-resin interface), or mixed (combination of adhesive and cohesive). figure (1) universal testing machine figure 2: sample holder. failure mode: to classify the type of the failure, which could be either cohesive, adhesive, or mixed (combination of adhesive and cohesive failure). statistics analysis: the spss software was used to perform the statistical analysis. one way analysis and normality test (shapiro-wilk) and was used to determined differences in bond strength within and between the groups (ibm spss statistics 20.0, spss inc., chicago, il, usa). the level of significance was set to α = 0.05. results: shear bond strength: the mean (and standard deviation) of shear bond strength are presented in table 1. mbep demonstrated the highest bond strength values. no statistically significant difference was found between the two different surface pretreatments (mbp and mbep) (p = 0.551). table 1: comparison of shear bond strength (mpa) between the two groups showing mean, standard deviation, and standard error of mean. se sd mean missing n groups 1.061 3.182 9.629 0 9 mbp 0.913 2.739 10.482 0 9 mbep difference -0.853 t = -0.610 with 16 degrees of freedom. (p = 0.551) 95 percent confidence interval for difference of means: -3.820 to 2.114 figure 3: mean shear bond strength values of the tested groups showing the shear bond strengths with standards error between the groups failure mode: figure 4,5 shows stereomicroscope images of the fracture surfaces of the dentin and ceramic substrates at a magnification of 6.4x. the distribution of the different failure mode of both groups mbp and mbep revealed that the predominant mode of failure (66.67% and 55.56 %) was cohesive failure, (22.22 %) adhesive for both and the remaining (11.11% and 22.22 %) mixed failure. 0 5 10 15 20 1 2 3 4 5 6 7 8 9 s b s [ m p a ] sample no. shear bond strength monobond plus monobond etch and prime j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 4 figure 4: representative images of failure mode of ceramic surface (cs) (ace) and dentin surface (ds) (bdf) in group mbp (a,b) adhesive; (c,d) cohesive; (e,f) mixed. figure 5: representative images of failure mode of ceramic surface (cs) (ace) and dentin surface (ds) (bdf) in group mbep (a,b) adhesive; (c,d) cohesive; (e,f) mixed. discussion: according to the results of this study the null hypothesis must be accepted. there are no significant differences in the shear bond strength (sbs) values between the treated groups. although bond strength tests are not fully standardized, they are considered essential to examine factors related to bonding effectiveness as well as for the screening of new materials (16). sbs tests are one of the most commonly used for testing dentin adhesion (17). this popularity may be related to the simplicity of specimen preparation. however, large bonded areas more than 0.8 mm diameter of the bonded area (macroshear) may include critical flaws at the interfaces resulting in lower bond strength value j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 5 as compared to the small bonded area of microshear and microtensile (16,18). moreover, there are concerns about the non-uniform stress generated along the interface as a consequence of specimen’s geometry and loading condition. in the present study, ceramic specimens were bonded to dentin with the luting cement to simulate the clinical situation. sbs to dentin with the hybridization mechanism ranges between 22 and 35 mpa. this strength is theoretically higher than that of enamel, because dentin is more resistant to shear fracture. the presence of more water in dentin than enamel, may affect the clinical longevity of dentin bonding. the success of all-ceramic restoration is greatly determined by the strength and durability of the formed bond between the three different components of the bonded area the tooth surface, cement and the ceramic. the mechanism of dentin adhesion, enhanced by hybrid layer formation between the resin and dentin, was proposed by nakabayashi et al (1982) (19). formation of hybrid layer is considered essential to create a strong bond between the resin and dentin. the penetration of adhesive monomers into the superficially demineralized dentin and subsequent polymerization are indispensable to create one of an ideal hybrid layer. when dentin is acid etched, the apatite phase of the smear-layer and of the underlying dentin is solubilized to permit exposure of the underlying collagen fibrils. these may leave spaces for bonding resin to penetrate (20). the extend of resin infiltration depends on the amount of apatite removed by conditioning and the moisture of dentin. the intrinsic moisture, i.e. the outward flow of dentinal fluid, may interfere with monomer infiltration into the dentin, depending on the monomer composition of the dbs’s (15). theoretically, the higher the tubule density and the more the tubules are widened by the etchant, the greater is the chance of obtaining a reliable bond because of the increase in the number and diameter of resin tags (21, 22). this can be true only for bonding systems in which an acid etching step is included and is important especially for crown preparations in which approximately two million tubules are exposed (23). there is little data published on the contribution of the tubule density to resin bonds. gwinnett et al. (24) showed that the resinreinforced (or hybridized) collagen network did not contribute any significant quantitative value per se to dentin bonding with an enamel–dentin bonding system. pashley et al. (21) correlated the dentin substrates at different depths with the bond strength using a theoretical model. the resulting calculations indicated the potential for higher bond strengths to deep dentin than to superficial dentin and the importance of resin tags in the development of strong bonds. this may explain the low values of bond strength in our study as we used the superficial dentin. by etching the inner side of the ceramic discs with hydrofluoric acid creates retentive etch pattern subsequently silanizing the etched surface. these micro-porosities increase the surface area for bonding and lead to a micromechanical interlocking of the resin cement. in addition to micro-porosities, micro-cracks were observed that grow when the etching time increases (25). these cracks can act as sources of crack initiation and slightly, although not significantly, decrease the flexural strength of the etched porcelain. weakening of the porcelain by etching was also noted in other in vitro studies (26, 27). silanization of etched porcelain with a bifunctional coupling agent provides a chemical link between the luting resin composite and porcelain. a silane group at one end chemically bonds to the hydrolysed silicon dioxide at the ceramic surface, and a methacrylate group at the other end with the adhesive resin. singlecomponent systems contain silane in alcohol or acetone and require prior acidification of the ceramic surface with hydrofluoric acid to activate the chemical reaction. with twocomponent silane solutions, the silane is mixed with an aqueous acid solution to hydrolyse the silane, so that it can react directly with the ceramic surface. if not used within several hours, silane will polymerise to an unreactive polysiloxane (28). several authors reported differences in bond strength dependent on the silane treatment used (29, 30, 31 and 32). in addition, heating of the silane-coated porcelain to 100°c resulted in bond strength twice as high than if no heating was used (33). monobond etch&prime significantly shortens the treatment time for all ceramic materials compared with the conventional procedure. enabling users to apply the same contact time for all materials reduces the risk of errors. the reason why monobond prime&etch achieves similar bond strengths as the combination of hf etching and monobond plus even if it produces a less pronounced etching pattern lies in the fact that the ammonium polyfluoride ions induce the formation of reactive silanol groups. when the ceramic is rinsed, the polyfluoride is removed and the silanol groups are no longer stabilized. this gives way to a highly effective j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 6 functionalization process that offsets the less pronounced etching pattern (34). the mode of failure in this study was predominantly cohesive failure (66.67%) followed by adhesive failure at the dentin-cement interface/mode (16.66%) and mixed failure (16.66%). correlating with findings of other researchers (35), the ceramic bond strength can be therefore interpreted to be stronger than the dentin-cement bond strength. the present study indicated that the use of the self-etching glass-ceramic primer as a pretreatment of ceramic enhanced the adhesion between ceramic and resin cement. this treatment is an alternative treatment to sandblastparticle-abrasion and avoids micro-crack formation and phase transitions that are detrimental to the longevity of the ceramic restoration. however, the monobond etch& prime treatment still requires further studies with use different types of resin composite cements. all the samples there were no adhesive mode of failure with the ceramic surface, it is still strong enough to produce sufficient microretention for a reliable adhesive bond, as confirmed by the bond strength measurements. conclusion: the new glass-ceramic primer is a self-etching single component without using hydrofluoric acid that produces an equivalent sbs and failure mode. monobond etch & prime more safe, simple in treatment and require less steps. acknowledgement this study was granted by the professor per vult von steyern and i have received helpful input from evaggelia papia, lecturer. i gratefully acknowledge the support and generosity of the department of materials science and technology faculty of odontology malmö, sweden, without which the present study could not have been completed. references: 1. matinlinna jp, lassila lvj, ozcan m, yli-urpo a, vallittu pk (2004). an introduction to silanes and their clinical applications in dentistry. int j prosthodont 17:155-164. 2. lung cyk, matinlinna jp (2012). aspects of silane coupling agents and surface conditioning in dentistry: an overview. dent mater j 28:467-477. 3. simonsen rj, calamia jr. tensile bond strength of etched porcelain. journal of dental research 1982, 62:297 abstract 1/54. 4. eliades gc, caputo aa, vougiouklakis gj. composition, wetting properties and bond strength with dentin of 6 new dentin adhesives. dent mater 1985; 1:170-176). 5. i. stangel, d. nathanson and c.s. hsu, shear strength of the composite bond to etched porcelain. journal of dental research 66 (1987), pp. 1460– 1465. 6. r. lu, j.k. harcourt, m.j. tyas et al., an investigation of the composite resin/porcelain interface. australian dental journal 37 (1992), pp. 12–19. 7. h. schäffer, h. dumfahrt and k. gausch, öberflächenstruktur und substanzverlust beim ätzen keramischer materialien. schweizerische monatsschrift zahnmedicin 90 (1989), pp. 530–543. 8. t.w. yen, r.b. blackmann and r.j. baez, effect of acid etching on the flexural strength of a feldspathic porcelain and a castable glass ceramic. the journal of prosthetic dentistry 70 (1993), pp. 224–233. 9. m. peumans, b. van meerbeek, y. yoshida et al., porcelain veneers bonded to tooth structure: an ultra-morphological fe-sem examination of the adhesive interface. dental materials (1999). 10. simonsen rj, calamia jr. tensile bond strength of etched porcelain. journal of dental research 1982, 62:297 abstract 1/54. 11. i. stangel, d. nathanson and c.s. hsu, shear strength of the composite bond to etched porcelain. journal of dental research 66 (1987), pp. 1460– 1465. 12. j.r. calamia, j. vaidyanathan, t.k. vaidyanathan et al., shear bond strength of etched porcelains. journal of dental research 64 (1985), p. 828 abstract 1096. 13. j.f. roulet, k.j.m. söderholm and j. longmate, effects of treatment and storage conditions on ceramic/composite bond strength. journal of dental research 74 (1995), pp. 381–387. 14. horn rh. porcelain laminate veneers bonded to etched enamel. dental clinics of north america 1983;27: 671-84. 15. n. nakabayashi and d.h. pashley. in: hybridization of dental hard tissue, quintessence publishing co., ltd, berlin (1998), pp. 65–69. 16. armstrong, s., s. geraldeli, et al. (2010). "adhesion to tooth structure: a critical review of "micro" bond strength test methods." dent mater 26(2): e50-62. 17. burke, f. j., a. hussain, et al. (2008). "methods used in dentine bonding tests: an analysis of 102 investigations on bond strength." eur j prosthodont restor dent 16(4): 158-165. 18. scherrer, s. s., p. f. cesar, et al. (2010). "direct comparison of the bond strength results of the different test methods: a critical literature review." dent mater 26(2): e78-93. 19. nakabayashi, n., k. kojima, et al. (1982). "the promotion of adhesion by the infiltration of monomers into tooth substrates." j biomed mater res 16(3): 265-273. 20. paul sj, welter dh, ghazi m, et al. nanoleakage at the dentin adhesive interface vs. microtensile bond strength. oper dent 1999;24:181-188. 21. d.h. pashley, b. ciucchi, h. sano, r.m. carvalho and c.m. russell, bond strength versus dentine structure: a modelling approach. arch oral biol 40 (1995), pp. 1109–1118. 22. m.c. cagidiaco, m. ferrari, a. vichi and c.l. davidson, mapping of tubule and intertubule https://maps.google.com/maps?ie=utf-8&q=dpt.of+materials+science+and+technology+faculty+of+odontology+se-205+06+malm%c3%b6,sweden https://maps.google.com/maps?ie=utf-8&q=dpt.of+materials+science+and+technology+faculty+of+odontology+se-205+06+malm%c3%b6,sweden https://maps.google.com/maps?ie=utf-8&q=dpt.of+materials+science+and+technology+faculty+of+odontology+se-205+06+malm%c3%b6,sweden j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 7 surface areas available for bonding in class v and class ii preparations. j dent 25 (1997), pp. 375– 389. 23. w.c. outhwaite, m.j. livingston and d.h. pashley, effects of changes in surface area, thickness, temperature and post-extraction time on human dentine permeability. arch oral biol 21 (1976), pp. 599–603. 24. a.j. gwinnett, f.r. tay, k.m. pang and s.h.y. wei, quantitative contribution of the collagen network in dentin hybridization. am j dent 9 (1996), pp. 104–144. 25. t.w. yen, r.b. blackmann and r.j. baez, effect of acid etching on the flexural strength of a feldspathic porcelain and a castable glass ceramic. the journal of prosthetic dentistry 70 (1993), pp. 224–233. 26. m.a. hussain, e.w. bradford and g. charlton, effect of etching on the strength of aluminious porcelain jacket crowns. british dental journal 147 (1979), pp. 89–90. 27. d.w. jones, the strength and strengthening mechanisms of dental ceramics. in: j.w. mclean editor, dental ceramicsproceedings of the first international symposium on ceramics quintessence publishing co, chicago (1983), pp. 83–136. 28. b.i. suh, all bond––fourth generation dentin bonding system. journal of esthetic dentistry 3 (1991), pp. 139–146. 29. a.m. lacy, j. laluz, l.g. watanabe et al., effect of porcelain surface treatment on the bond to composite. the journal of prosthetic dentistry 60 (1988), pp. 288–291. 30. j.i. nicholls, tensile bond of resin cements to porcelain veneers. the journal of prosthetic dentistry 60 (1988), pp. 443–447. 31. j.r. calamia, j. vaidyanathan, t.k. vaidyanathan et al., shear bond strength of etched porcelains. journal of dental research 64 (1985), p. 828 abstract 1096. 32. g. müller, ätzen und silaniseren dentaler keramiken. deutsche zahnärtzliche zeitschrift 43 (1988), pp. 438–441. 33. j.f. roulet, k.j.m. söderholm and j. longmate, effects of treatment and storage conditions on ceramic/composite bond strength. journal of dental research 74 (1995), pp. 381–387. 34. tian, t., et al., aspects of bonding between resin luting cements and glass ceramic materials. dent. mater., 2014. 30(copyright (c) 2015 american chemical society (acs). all rights reserved.): p.e147-e162. 35. a. piwowarczyk, h. c. lauer, and j. a. sorensen, “in vitro shear bond strength of cementing agents to fixed prosthodontic restorative materials,” journal of prosthetic dentistry, vol. 92, no. 3, pp. 265–273, 2004. j bagh college dentistry vol. 29(1), march 2017 evaluation of the effect restorative dentistry 8 :الخالصة الليثيوم ديسيليكات سيراميك المزجج. e.maxالغرض من هذه الدراسة لتقييم تأثير العالجات السطحية المختلفة بين العاج و سطح القريب المواد والطرق تم تضمين ثمانية عشر من األضراس المستخرجة الثالثة في راتنجات االيبوكسي. وقطعت األسنان مقطعا عموديا في االتجاه ال ورقة السيليكون كربيد. 066والوحشي باستخدام مشرح األنسجة الصلبة ذو السرعة المنخفضة. تم تلميع األسطح الشدقية واللسنية من كل قسم شقة باستخدام الرقم ملم. تم تقسيم األقراص إلى 2.2ملم وارتفاع 7.4تم تحضير ثمانية عشر أسطوانة من السيراميك تتكون من الليثيوم ديسيليكات سيراميك المزجج أعدت بقطر monobond etchتعامل مع e.maxوالمجموعة الثانية ) monobond plus) تعامل مع حامض الهيدروفلوريك و e.max ) :(9مجموعتين االولى )العدد= &bond تم لصق السيراميك مع األسنان باستخدام .)multilink automix رة الغرفة قبل وضعها في جهاز التبديل ساعة في درجة حرا 27وتخزينها لمدة الحراري وتحميلها الحقا إلى الفشل في آلة اختبار العالمي. تم تسجيل وضع الفشل لكل عينة. عدم وجود فرق ذو داللة إحصائية بينهما. تم استخدام mbp,mbep (. أظهرت sbsأظهرت اعلى قوة االلتصاق ) tألنتيجة تحليل قوة االلتصاق وتحليل اختبار لتحديد االختالفات في قوة االلتصاق داخل وبين المجموعات. وكان الفشل متماسك في األسمنت الراتنج الغالب مع نتائج أعلى في حين tأنوفا في اتجاه واحد واختبار الصقة ومختلطة مع أقل ومساوية. له تأثير إيجابي على قوة االلتصاق بين العاج الليثيوم ديسيليكات سيراميك المزجج مع االسمنت prime &monobond etchع ألخالصة المعالجة السطحية م .monobond plusالراتج مقارنة مع lamia f.docx j bagh college dentistry vol. 28(2), june 2016 an assessment of oral diagnosis 58 an assessment of sagittal condylar position of tmj dysfunction in centric occlusion by using cone beam computed tomography lamia h. al-nakib, b.d.s, m.sc. (1) ako omer abdullah,b.d.s., m.sc. (2) saeed a.abd al-kareem, b.d.s., m.sc. (3) sangar hamid ali, b.d.s., m.sc. (4) abstract background: temporomandibular joint (tmj) is a compound articulation formed from the articular surfaces of the temporal bone and the mandibular condyle.cbct imaging of tmj is that it allows accurate measurements of the volume and surface of the condyle. the aim of the study is to assess the sagittal position of mandibular condyle in patients with temporomandibulardysfunction using cone beam computed tomography in centric occlusion. materials and methods: cbct images for all patients were obtained in an upright position using new tom giano cbct with different field of view (11 x 8), (11 x 5), and (8 x 8) and exposure factors was changed accordingly using nnt version 5.1 software for sagittal reconstruction, anterior, superior and posterior joint spaces was measured. results: there was a significant change in the anterior, posterior and superior joint spaces when compared to normal functioning tmj. the sagittal position of the condyle in glenoid fossa could be affected by tmj dysfunction and it would be positioned centrally but slightly inferior to the normal position according to the results of this study. there was no significant difference in the sagittal condylar position in glenoid fossa between sexes. there was significant difference in the value of anterior, posterior and superior tmj spaces between right and left sides of the mandible in both normal cases and tmjd. conclusion: sagittal section of temporomandibular joint revealed that tmj dysfunction affects the joint spaces in sagittal plane. it means significant changes occur in the value of anterior, posterior and superior joint spaces when compared to normal functioning tmj. keywords: condylar position, tmj dysfunction cone beam computed tomography. (j bagh coll dentistry 2016; 28(2):58-62). introduction temporomandibular joint (tmj) is one of the complex joints of the body which comprises the mandibular condyle, and the temporal bone forming the superior component of the joint (1). the articular eminence is a part of the temporal bone on which the condylar process slides during mandibular movements (2). an articular disk is interposed between the temporal bone and the mandible, dividing the joint space into two components, i.e. an upper one in which gliding movements occur, and a lower one characterized by rotation or hinge movements. temporomandibular joint is morphologically structured to support the specialized functional demands of mastication(3). a fundamental question in dentistry is what to be regarded as the optimal position of the condyle in the glenoid fossa when the teeth are in maximum intercuspation (4). (1)professor, department of oral diagnosis, college of dentistry/ university of baghdad. (2)specialist dentist, sulaimania directory of health, ministry of health in kurdistan rejoin. (3) assistant professor, department of oral diagnosis, school of dentistry, faculty of medical sciences/university of sulaimania. (4) specialist dentist, khanzad teaching center/ erbil,ministry of health in kurdistan rejoin. the optimal condylar position in the glenoid fossa can be determined by the dimension of the joint space. radiographically the joint space is a total term that is used for the description of the radiolucent zone that is placed between condylar and temporal parts (5). standard radiographic studies of the temporomandibular joint (tmj), such as the plain film radiography and panoramic radiography, have little capacity to reveal anything more than gross osseous changes within the joint (6). the use of conventional radiographs has inherent limitations such as structural superimpositions in two-dimensional imaging, particularly in the region of the petrous temporal bone, the mastoid process, and the articular eminence, which indeed limits an accurate view of the tmj (7). even conventional ct was used for tmj evaluation and it was with reasonable results (8) but ct is performed with the patient in the supine position, rather than in the upright position, which may have led to errors in the evaluation of the condyle-fossa relationships (9). the high cost, access to equipment, motion artifact and the relatively high radiation dose have limited the widespread use of ct for tmj evaluation (10).while magnetic resonance imaging (mri) is j bagh college dentistry vol. 28(2), june 2016 an assessment of oral diagnosis 59 considered as one of the most useful tools that shows disc displacement. unfortunately, mri gives little information of the bone tmj structures (5). cone beam computed tomography (cbct) for dental and maxillofacial diagnostic osseous tasks has been developed as an alternative to conventional ct, the results of cbct technology in images of ct-like quality were obtained on the basis of less expensive equipment and components, shorter patient examination time and much lower radiation dose than required for conventional ct. in addition, the scanning procedure of the patient and the software for image reconstruction connected with cbct are very user-friendly (11). cone beam computed tomography is similar to conventional ct in diagnosing different osseous conditions and that it provides a costand dose effective diagnostic options (12) . a large body of literatures has been published recently about cbct in temporomandibular joint imaging due to the fact that cbct has inspired research in tmj imaging. an important advantage of cbct imaging of tmj is that it allows accurate measurements of the volume and surface of the condyle. these measurements are extremely advantageous in the clinical practice when treating patients with tmj dysfunctions (13). many in vitro cadaveric studies have explored the role of cbct in assessing bony defects and osteophytes. erosive changes in the tmj are most effectively diagnosed using cbct in the 6 inch fov as compared to the 12 inch fov(14). alkhader et al.(15)performed a comparative study between cbct and mri and it was revealed that cbct is better than mri in detecting changes in shape (flattening, osteophyte formation or erosion) rather than changes in size, however there is a poor correlation between condylar changes observed on cbct images and clinical signs and symptoms seen in patients with tmj osteoarthritis (oa), cbct plays an important role in diagnosing early stages of juvenile idiopathic arthritis (jia) in children which, when undetected, can damage facial development and cause growth alterations. farronato et al.(16)concluded from their study that cbct can be used to volumetrically quantify the tmj damage in these patients by measuring condylar and mandibular volumes. materials and methods after approval of scientific ethical committee/school of dentistry at sulaimany university a cross-sectional study carried out on thirty-two patients attending oral and maxillofacial department of dental center in erbil city from february to june 2014. (all patients were between 20 to 35 years old). patients were classified into two groups, control group: 32 joints of 16 patients (8 males and 8 females) attending denta center for different purposes other than tmj problems and tmjd group: 32 joint of 16 patients with pre diagnosed to have tmj dysfunction by oral medicine specialist (8 males and 8 females). cbct images for all patients were obtained in an upright position using new tom giano cbct with different field of view (11 x 8), (11 x 5), and (8 x 8) and exposure factors will be change accordingly using nnt version 5.1 software for sagittal reconstruction. at the beginning, on axial slices, the cut that showed the largest medio-lateral dimension of condylar heads was selected (figure 1). figure 1: largest medio-lateral dimension of condylar head on axial slice next, true sagittal images with 0.15 mm thickness and interval distance on medio-lateral axis of condyle were reconstructed then, two true central sagittal images with 0.15 mm thickness and interval distance were chosen. after that, anterior, superior and posterior joint spaces were measured on these reconstructed sagittal images. initially, a horizontal line on uppermost area of glenoid fossa was drawn and the intersection of this line with glenoid fossa was selected as superior reference point (s), sequentially, this point was connected to the most prominent points on anterior (a) and posterior (p) aspects of the condyle. finally, the perpendicular distance from a and p tangent points to glenoid fossa was measured as anterior and posterior joint spaces (ajs, pjs), the right distance between s point and superior prominent point of condylar head were considered as superior joint space (sjs). an nnt version 5.1 software was used for sagittal reconstruction and measurements (figure 2). j bagj bagh college dentistry oral diagnosis figure 3: measurement of superior, anterior and posterior joint spaces results thirty two patients were participated in this study (16 males two groups, control and tmjd group table 1: right and left temporo discussion in the current study, the value of sjs was the greatest among tmj spaces followed by ajs and pjs in both sexes in control and tmjd groups. this result is in agreement with ikeda and kawamura hansson thickness in autopsy materials and found that the thickness of the posterior and anterior bands was h college dentistry oral diagnosis figure 3: measurement of superior, anterior and posterior joint spaces results thirty two patients were participated in this study (16 males and 16 females) and were divided into two groups, control and tmjd group table 1: right and left temporo table 2 table 3: r discussion in the current study, the value of sjs was the greatest among tmj spaces followed by ajs and pjs in both sexes in control and tmjd groups. this result is in agreement with ikeda and kawamura hansson et al. (17) who directly thickness in autopsy materials and found that the thickness of the posterior and anterior bands was h college dentistry figure 3: measurement of superior, anterior and posterior joint spaces for male patient with tmjd thirty two patients were participated in this study and 16 females) and were divided into two groups, control and tmjd group table 1: right and left temporo tm joint space right ajs left ajs right pjs left pjs right sjs left sjs table 2: right and left temporomandibular joint spaces in control group tm joint space ajs pjs sjs table 3: right and left tempor tm joint space ajs pjs sjs in the current study, the value of sjs was the greatest among tmj spaces followed by ajs and pjs in both sexes in control and tmjd groups. this result is in agreement with dalili et al ikeda and kawamura(4)but is incompatible with who directly thickness in autopsy materials and found that the thickness of the posterior and anterior bands was h college dentistry vol. 2 figure 3: measurement of superior, anterior for male patient with thirty two patients were participated in this study and 16 females) and were divided into two groups, control and tmjd group table 1: right and left temporo-mandibular joint spaces in control and tmjd groups joint space mean right ajs 2.36 left ajs 2.01 right pjs 2.00 left pjs 2.21 right sjs 2.43 left sjs 2.79 right and left temporomandibular joint spaces in control group tm joint space ajs 2.36 pjs 2.00 sjs 2.43 ight and left tempor tm joint space ajs 2.61 pjs 2.18 sjs 3.57 in the current study, the value of sjs was the greatest among tmj spaces followed by ajs and pjs in both sexes in control and tmjd groups. dalili et al. (5) and but is incompatible with measured disc thickness in autopsy materials and found that the thickness of the posterior and anterior bands was vol. 28(2), june 60 figure 3: measurement of superior, anterior for male patient with thirty two patients were participated in this study and 16 females) and were divided into the mean age 3.6 years and that of (temporo dysfunction) tmjd group was 29.3 with similar sex distribution tmjd group and control group (all three spaces were presented to be larger in tmjd group than control group, p<0.01 and p<0.0 (table 1), but a non sexes when a comparison of temporomandibular joint spaces (ajs, pjs, and sjs) in control and tmjd groups were table 2 shows the mean temporomandibular joint space in control group. right ajs was signif while the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.01 and p<0.05. table 3 shows the mean temporomandibular joint space in tmjd group. the right ajs was significantly left ajs, however the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.05 and p<0.01 respectively. mandibular joint spaces in control and tmjd groups control mean + sd mean 2.36 + 0.31 2.01 + 0.26 2.24 2.00 + 0.12 2.18 2.21 + 0.18 2.35 2.43 + 0.17 3.57 2.79 + 0.41 3.85 right and left temporomandibular joint spaces in control group right 2.36 + 0.31 2.01 2.00 + 0.12 2.21 2.43 + 0.17 2.79 ight and left temporomandibular joint spaces in tmjd groups right 2.61 + 0.42 2.24 2.18 + 0.19 2.35 3.57 + 0.27 3.85 in the current study, the value of sjs was the greatest among tmj spaces followed by ajs and pjs in both sexes in control and tmjd groups. and but is incompatible with measured disc thickness in autopsy materials and found that the thickness of the posterior and anterior bands was more than that of the intermediate zone. in addition, the significant difference in the thickness of intermediate joi the thickness of the soft tissues covering the fossa. revealed that the values of ajs, pjs, and sjs were greater in tmjd group than in the control group dysfunction which means in the centric position of june 2016 the mean age 3.6 years and that of (temporo dysfunction) tmjd group was 29.3 with similar sex distribution there was a tmjd group and control group (all three spaces were presented to be larger in tmjd group than control group, p<0.01 and p<0.0 (table 1), but a non sexes when a comparison of temporomandibular joint spaces (ajs, pjs, and sjs) in control and tmjd groups were table 2 shows the mean temporomandibular joint space in control group. right ajs was signif while the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.01 and p<0.05. table 3 shows the mean temporomandibular joint space in tmjd group. the right ajs was significantly left ajs, however the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.05 and p<0.01 respectively. mandibular joint spaces in control and tmjd groups tmjd mean + sd 2.61 +0.24 2.24 + 0.16 2.18 + 0.19 2.35 + 0.20 3.57 + 0.27 3.85 + 0.31 right and left temporomandibular joint spaces in control group left 2.01 + 0.26 2.21 + 0.18 2.79 + 0.41 omandibular joint spaces in tmjd groups left 2.24 + 0.16 2.35 + 0.20 3.85 + 0.31 more than that of the intermediate zone. in addition, the significant difference in the thickness of intermediate joi the thickness of the soft tissues covering the fossa. the results obtained in the present study revealed that the values of ajs, pjs, and sjs were greater in tmjd group than in the control group, all the three spaces dysfunction which means in the centric position of + sd of control group was 28.7 3.6 years and that of (temporo dysfunction) tmjd group was 29.3 with similar sex distribution. there was a significant difference between tmjd group and control group (all three spaces were presented to be larger in tmjd group than control group, p<0.01 and p<0.0 (table 1), but a non-significant difference sexes when a comparison of temporomandibular joint spaces (ajs, pjs, and sjs) in control and tmjd groups were assessed table 2 shows the mean + sd of the right and left temporomandibular joint space in control group. right ajs was significantly higher than left ajs while the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.01 and table 3 shows the mean + sd of the right and left temporomandibular joint space in tmjd group. the right ajs was significantly left ajs, however the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.05 and p<0.01 respectively. mandibular joint spaces in control and tmjd groups p value 0.016 0.005 0.003 0.046 0.001 0.001 right and left temporomandibular joint spaces in control group p value 0.028 0.001 0.037 omandibular joint spaces in tmjd groups p value 0.035 0.019 0.001 more than that of the intermediate zone. in addition, the significant difference in the thickness of intermediate joint space can be due to ignoring the thickness of the soft tissues covering the fossa. the results obtained in the present study revealed that the values of ajs, pjs, and sjs were greater in tmjd group than in the control all the three spaces dysfunction which means in the centric position of an assessment sd of control group was 28.7 3.6 years and that of (temporo-mandibular joint dysfunction) tmjd group was 29.3 + . significant difference between tmjd group and control group (all three spaces were presented to be larger in tmjd group than control group, p<0.01 and p<0.05 in both sides significant difference sexes when a comparison of temporomandibular joint spaces (ajs, pjs, and sjs) in control and assessed (p>0.05). sd of the right and left temporomandibular joint space in control group. icantly higher than left ajs while the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.01 and sd of the right and left temporomandibular joint space in tmjd group. the right ajs was significantly higher than the left ajs, however the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.05 and p<0.01 respectively. mandibular joint spaces in control and tmjd groups right and left temporomandibular joint spaces in control group omandibular joint spaces in tmjd groups more than that of the intermediate zone. in addition, the significant difference in the thickness nt space can be due to ignoring the thickness of the soft tissues covering the fossa. the results obtained in the present study revealed that the values of ajs, pjs, and sjs were greater in tmjd group than in the control all the three spaces were larger in tmj dysfunction which means in the centric position of an assessment sd of control group was 28.7 + mandibular joint 4.4 years significant difference between tmjd group and control group (all three spaces were presented to be larger in tmjd group than 5 in both sides significant difference in both sexes when a comparison of temporomandibular joint spaces (ajs, pjs, and sjs) in control and sd of the right and left temporomandibular joint space in control group. icantly higher than left ajs while the left pjs and sjs were significantly higher than the right pjs and sjs, p<0.01 and sd of the right and left temporomandibular joint space in tmjd group. higher than the left ajs, however the left pjs and sjs were significantly higher than the right pjs and sjs, mandibular joint spaces in control and tmjd groups more than that of the intermediate zone. in addition, the significant difference in the thickness nt space can be due to ignoring the thickness of the soft tissues covering the fossa. the results obtained in the present study revealed that the values of ajs, pjs, and sjs were greater in tmjd group than in the control were larger in tmj dysfunction which means in the centric position of an assessment of j bagh college dentistry vol. 28(2), june 2016 an assessment of oral diagnosis 61 mandible in patients with tmj dysfunction the head of the condyle in the glenoid fossa is positioned more centrally and inferiorly when compared to normal subjects (centrally and slight inferior position is more common than other positions). the results of wiese et al. (18)and dalili et al. (5)studies were similar to the present results, that the condyle was positioned centrally in most tmjs. but the results are in agreement with incesu et al. who reported the posterior position of condyle as the most common position in patients with temporomandibular joint disorder. sicher et al. (19)wrote that, in all synovial joints in the human body, the articulating surfaces of the opposing bones are kept in firm contact by the associated ligaments and musculature, and that firm contact is maintained with the disc closely fitted between the opposing articular surfaces throughout the range of jaw movement. if this close relationship between the eminence and the condyle is lost due to disc displacement, there should be changes in joint space. the present study included joints with no signs of tmd which were considered as normal samples based only on radiographic and chair-side examinations, and cases having tmd by using pain, joint sound, tenderness of joint area and limitation of mouth opening leaving the possibility of undetected disc displacements. in addition, the normalcy of disc position in a static mandibular position does not ensure its functional normalcy. the older age range of the subjects might be associated with an increased risk of disc displacement and morphologic changes in joint structures. gateno et al.(20) found that in patients with anterior disc displacement, the position of the condylar head was significantly different than in patients with normal joints in which condylar heads in patients with anterior disc displacement were positioned more posteriorly and superiorly within the fossa than in patients with normal joints. however, there is one author who reported no difference in condylar position between add joints and normal joints(21). according to the present result, there is no significant difference in the value of ajs, pjs and sjs between sexes and this result is in agreement with ikeda and kawamura(4)and in agreement with dalili et al. (5), who found that sjs showed statistically significant difference between the genders using limited cbct. it is also incompatible with kinniburgh et al. (22)who used the conventional tomography, and this different result may be because of the difference in the population that they took their samples from, compared to the sample of this study which was taken from kurdish population. in the control group, the value of right ajs was greater than the left side. the left pjs and sjs were significantly higher than the right pjs and sjs. this result was the same for tmjd group. this result is in agreement with dalili et al. (5). significant differences between the values of aja, pjs and sjs in right and left sides were observed in the study by dalili et al.(5).previous studies concluded that asymmetric tmj spaces were usually associated with tmj dysfunction conversely; bilateral condylar concentricity was associated with an absence of clinical symptoms. moreover, questions have not been clearly answered regarding the potential of any differences in patients with or without symmetry as to the right-sided or left-sided condylar positioning or deviated or non-deviated sides, as well as how much of a difference between the right and left sides exists (9). kim et al. (9)investigated whether the condylarfossa relation is bilaterally symmetrical in class iii patients with or without asymmetry, compared to that of the subjects with normal occlusion and found that the condylar spaces of ajs, sjs, and pjs were not significantly different whether the patient had a class iii malocclusion or class i normal occlusion and whether the patient had symmetry or asymmetry. this result showed that the tmj spaces were not significantly different regardless the presence of asymmetry. references 1. shahidi s, vojdani m, paknhad m. correlation between articular eminence steepness measured with cone-beam computed tomography and clinical dysfunction index in patients with temporomandibular joint dysfunction. oral surg oral med oral pathol oral radiol 2013; 116(1): 91-7. 2. sumbullu ma, caglayan f, akgul hm, yilmaz ab. radiological examination of the articular eminence morphology using cone beam ct. dentomaxillofacradiol 2012;41: 234–40. 3. mastumoto m, bolognese a. study of radiographic morphology of the temporomandibular joint. braz dent j1993;4(2): 97-103. 4. ikeda k, kawamura a. assessment of optimal condylar position with limited cone-beam computed tomography. am j orthod dentofac orthop 2009; 135(4):495-501. 5. dalili z, khaki n, kia sj, salamat f. assessing joint space and condylar position in the people with normal function of temporomandibular joint with cone-beam computed tomography. dental res j 2012; 9(5):60712. 6. schlueter b, kim kb, oliver d, sortiropoulos g. cone beam computed tomography 3d reconstruction of the mandibular condyle. angle orthod2008; 78(5):880-8. 7. arieta-miranda jm,silva-valencia m, flores-mir c, paredes-sampen na, arriola-guillen le. spatial analysis of condyle position according to sagittal j bagh college dentistry vol. 28(2), june 2016 an assessment of oral diagnosis 62 skeletal relationship, assessed by cone beam computed tomography. progorthod 2013; 18(1):36. 8. abdul-nabi la, al-nakib lh. flattening of the posterior slope of the articular eminence of completely edentulous patients compared to patients with maintained occlusion in relation to age using computed tomography. jbaghcoll dentistry 2015; 27(2): 66-71. 9. kim ho, lee w, kook ya, kim y. comparison of the condyle-fossa relationship between skeletal class iii malocclusion patients with and without asymmetry: a retrospective three-dimensional cone-beam computed tomograpy study. korean j orthod2013; 43(5):209-217. 10. barghan s, tetradis s, mallya s. application of cone beam computed tomography for assessment of the temporomandibular joints. aust dent j 2012; 57(suppl 1):109-18. 11. hintze h, wiese m,wenzel a. cone beam ct and conventional tomography for the detection of morphological temporomandibular joint changes cone beam ct and conventional tomography for the detection of morphological temporomandibular joint changes.dentomaxillofacradiol 2007; 36(4):192-7 12. krisjane z, urtain i, krumania g, neimane l, ragovska i. the prevalence of tmj osteoarthritis in asymptomatic patients with dentofacial deformities: a cone beam ct study. inter j oral and maxillofacsurg 2012;41(6):690-5. 13. tecco s, saccucci m, nucera r, polimeni a,pagnoni m, cordasco g, et al. condylar volume and surface in caucasian young adult subjects. bmc med imaging 2010;31:10-28. 14. librizzi zt, tadinada as, valiyaparambil jv, lurie ag, mallya sm. cone-beam computed tomography to detect erosions of the temporomandibular joint: effect of fi eld of view and voxel size on diagnostic efficacy and effective dose. am j orthod dentofac orthop 2011;140:e25-30. 15. alkhader m, ohbayashi n, tetsumura a, nakamura s, okochi k, momin ma, et al. diagnostic performance of magnetic resonance imaging for detecting osseous abnormalities of the temporomandibular joint and its correlation with cone beam computed tomography. dentomaxillofacradiol2010;39:270-6. 16. farronato g, garagiola u, carletti v, cressoni p, mercatali l, farronato d. change in condylar and mandibula morphology in juvenile idiopathic arthritis: cone beam volumetric imaging. minerva stomatol 2010;59:519-34. 17. hansson t, oberg t, carlsson ge, kopp s. thickness of the soft tissue layers and the articular disk in the temporomandibular joint. actaodontolscand 1977; 35:77-83. 18. wiese m, wenzel a, hintze h, petersson a, knutsson k, bakke m, et al. osseous changes and condylar position in tmj tomograms: impact of rdc/tmd clinical diagnosis on agreement between expected and actual fi nding. oral surg oral med oral pathol oral radiolendod2008;106:52-63. 19. sicher h, dubrule el. sicher’s oral anatomy. 5th ed. st. louis: c.v. mosby; 1980. p.158. 20. gateno j, anderson pb, xia jj, horg jc, teichgraeber jf, liebschner ma. a comparative assessment of mandibular condylar position in patients with anterior disc displacement of the temporomandibular joint. j oral maxillofacsurg2004;62:39-43. 21. katzberg rw, keith da, ten eick wr, et al: internal derangements of the temporomandibular joint: an assessment of condylar position in centric occlusion. j prosthet dent 1983;49:250. 22. kinniburgh rd, major pw, nebbe b, west k, glover ke. osseous morphology and spatial relationships of the temporomandibular joint: comparisons of normal and anterior disc positions. angle orthod 2000; 70:7080. j bagh college dentistry vol. 30(2), june 2018 effect of alendronate oral and maxillofacial surgery and periodontics 17 effect of alendronate treatment on salivary levels of osteoprotegrin and tnf-α in postmenopausal woman with osteoporosis and periodontal diseases aseel j. ibraheem, b.d.s. (1) aysar n. mohammed, b.d.s., m.sc. (2) abstract background: all diseases concerning bone destruction such as osteoporosis and periodontal diseases share common pattern in which the osteoclast cells are absolutely responsible for bone resorption that occurred when osteoclast activity exceeds osteoblast activity. osteoprotegrin (opg) considered as novel soluble decoy receptor known as “bone protector” since it prevents extreme bone resorption through inhibition of differentiation and activity of osteoclast by competing for binding site. it binds to receptor activator of nuclear factor kappa-b ligand (rankl) and prevent its interaction with receptor activator of nuclear factor kappa-b (rank), thus inhibits osteoclast formation. tnf-α is a pro-inflammatory cytokines having a broad range of important roles in regulation of immune system and bone resorption through the stimulation of osteoclastogenesis. alendronate (aln) diminishes the expression of osteoclast activating factors and cytokines such as rankl and enhances the production of decoy receptor osteoprotegerin in osteoblast cells. moreover, it decreases the production of proinflammatory cytokines such as tnfα by macrophage, stimulates apoptosis of monocyte-macrophage cell lines derivative and reduces inflammatory response. aims of the study: 1. to assess the effect of alendronate treatment on salivary levels of osteoprotegrin and tnf-α in postmenopausal women with osteoporosis and periodontal disease 2. to find any possible correlation between salivary levels of osteoprotegrin and tnf-α in control and study groups. materials and methods: total sample of 90 female subjects (55-65 years) were divided into 3 groups, (30 subjects in each group): first control group involved systemically healthy subjects with healthy periodontium, second group involved postmenopausal women with osteoporosis under alendronate treatment for(3-6)months (alendronate group), third group involved postmenopausal women with osteoporosis without alendronate treatment(osteoporosis group). the last two groups were subdivided into two sub –groups (15 subjects in each sub-group) of gingivitis and periodontitis subjects respectively. salivary samples were collected from all subjects and salivary levels of osteoprotegrin and tnfα were determined by enzyme –linked immune sorbent assay (elisa). results: highest median value of salivary (opg) was found in alendronate group followed by control group while the lowest value was found in osteoporosis group. highest median value of tnfα was found in osteoporosis group followed by control group and alendronate group respectively with highly significant differences between them. spearman correlation between salivary levels of tnf-α and opg showed nonsignificant correlation at all subgroups. conclusion: subjects with osteoporosis in this study had greater levels of tnf-α and decrease in the level of opg comparing with patients under alendronate treatment. alendronate treatment for women with osteoporosis and periodontal disease may have beneficial outcome. keywords: periodontal diseases, osteoporosis, alendronate, osteoprotegrin, tnf-a. (j bagh coll dentistry 2018; 30(2): 17-22) introduction estimation of the association between osteoporosis (op) and periodontal disease (pd) is confused by the truth that both conditions are caused by incorporation of multiple etiological factors for disease initiation and progression (1). it was found that periodontal disease destruction might be greatly affected by the systemic loss of bone associated with osteoporosis (2). discovery of opg/ receptor activator of nuclear factor kappa-b (rank)/ and receptor activator of nuclear factor kappa-b ligand (rankl) system develops the perception about molecular system concerned with the balancing of bone turnover. binding of rankl to rank on preosteoclast and osteoclast (oc) cells is crucial for their maturation and activity (3). (1) master student, (2) assistant professor, department of periodontics, college of dentistry, university of baghdad. osteoprotegrin (opg) and receptor activator of nuclear factor kappa-b ligand (rankl) act as negative and positive regulators in osteoclastogenesis and bone resorption. opg is a soluble molecule that inhibits osteoclast differentiation. it binds to rankl and inhibits its interaction with rank leading to neutralization and inhibition of oc formation (4), as well as provoking apoptosis of matured oc (5, 6, 7) . involvement of the rankl/opg system is well recognized in the pathogenesis of bone diseases and mineral metabolism, such as postmenopausal osteoporosis, (8). biological analysis of rankl and opg for periodontitis patients may provide information about periodontal disease status, however may not be capable to expect the activity of disease prospectively (9). periodontitis is related to increase rankl and decreased opg levels in gingival tissue and biological fluids including saliva and gingival crevicular fluid (gcf), in other words, periodontitis is related to increase j bagh college dentistry vol. 30(2), june 2018 effect of alendronate oral and maxillofacial surgery and periodontics 18 rankl/opg ratio. evidence obtained from experimental studies advocated that increase bone resorption after menopause may be due to excessive activation of osteoclast (oc) by increase proinflammatory cytokines production such as tnf-α due to decrease estrogen secretion, which considered as critical factor in the pathogenesis and development of pd as well as osteoporosis (10). alendronate (aln) an aminobisphosphonate is an individual of the second generations of bisphosphonates which are chemical analogs of pyrophosphate (a result of human metabolism) established to be capable of inhibition of bone resorption by osteoclast through modulation of bone mineralization. various studies confirmed that the systemic use of aln in humans and some animal models reduced bone loss and increased bone density. it was also proved that treatment with aln in postmenopausal women with osteoporosis carries a considerable improvement in bone mass (11). the aims of this study were to assess the effect of alendronate treatment on salivary levels of opg and tnf-α in postmenopausal women with osteoporosis and periodontal disease and to find any possible correlation between salivary levels of opg and tnf-α in control and study groups. materials and methods total sample of 90 female subjects (55-65years) were selected to take part in this study. the subjects recruited for this study were attending to the branch of rheumatology of baqubah teaching hospital in baqubah city. salivary sample collection was started from 7th december 2016 till 2th april 2017.each subject was informed about the aims and protocol of the study and they were permitted to accept or reject to participate in the study. all subjects were divided into three groups: 1-first group (control group): 30 healthy (systemically and periodontally) postmenopausal women. 2-second group (aln group): 30 post postmenopausal osteoporosis women under aln treatment for a period of 3-6 months. they were further divided into two subgroups of 15 gingivitis (alng) and 15 periodontitis (alnp). 3-third group (op group): 30 post postmenopausal women with osteoporosis without alendronate treatment. they were further divided into two subgroups of 15 gingivitis (opg) and 15 periodontitis (opp). about five ml of unstimulated salivary sample were collected from all subjects in to a sterile disposable test tube; the samples were placed in a cooling package for inhibition of microorganism growth. each donor number and group was written on each corresponding tube, and then salivary samples were centrifuged for 20 minutes at 3000 rpm. the supernatant was separated using micropipette in to two eppendorf tubes and stored at -20 ͦ c in deep freeze for later analysis by enzyme linked immunosorbent assay (elisa) kit for quantitative determination of salivary opg and tnfα. the laboratory tests were done in the laboratory of baqubah teaching hospital. at the time of chemical analysis, all salivary samples were defreezed at room temperature before investigation (12). statistical analysis was done using kruskal-wallis h test, mannwhitney u test, dun test for multiple comparisons with control, and spearman's rank correlation coefficient test (r). results the results in this study showed that the highest median value of opg found in aln group (7.25) followed by control (3.35) then op group (2.05) with highly significant difference between them. the median value for gingivitis and periodontitis in aln group (7.20 and 7.30 respectively) were higher than the median value of gingivitis and periodontitis in op group (2.20 and 2.00 respectively) with highly significant difference between them as illustrated in table 1. multiple comparisons among groups were showed highly significant difference when compare between each two group (table 2). inter group comparison in table 3, showed non-significant difference between alng and alnp and between opg and opp subgroups with nearly an equal median value between gingivitis and periodontitis in each group (7.20, 7.30, 2.20 and 2.00 respectively). multiple comparisons of each subgroup with control group (table 4) showed highly significant difference when compare each subgroup with control. regarding tnf-α the highest median value was in op group (281.90) followed by control then aln group (144.80 and 113.45 respectively) with highly significant difference between them. when compared gingivitis and periodontitis in aln and op group the median value for op group were higher than median value for aln group in both gingivitis and periodontitis (281.40, 283.10, 112.50 and 114.50 respectively) with highly significant difference between them (table 5). multiple comparisons among groups were showed highly significant difference between each two group (table 6). inter group comparisons in table 7 j bagh college dentistry vol. 30(2), june 2018 effect of alendronate oral and maxillofacial surgery and periodontics 19 showed nearly an equal median value between alng and alnp (112.50 and 114.50) and between opg and opp (281.40 and 283.10 respectively) with non-significant difference between them. multiple comparisons of each subgroup with control group (table 8) showed highly significant difference when compare each subgroup with control. spearman’s rank correlation coefficient between salivary levels of tnf-α and opg showed non-significant correlation at all subgroups. table 1: the concentration of salivary opg for study and control group with comparison of gingivitis and periodontitis between study groups. statistics groups gingivitis periodontitis control aln op aln op aln op median 3.35 7.25 2.05 7.20 2.20 7.30 2.00 mean rank 45.50 75.50 15.50 23 8 23 8 statistic kruskall-wallis=79.185 p=0.000 hs z=4.670 p=0.000 hs z=4.675 p=0.000 hs kruskall-wallis h test, z = mann-whitney u test table 2: multiple comparison among groups for salivary opg concentration. groups z p sig. (control) x (aln) 4.45 0.000 hs (control) x (op) 4.45 0.000 hs (aln) x (op) 8.899 0.000 hs table 3: inter group comparisons of salivary opg concentration. statistics inter groups comparisons subgroups alng alnp opg opp median 7.20 7.30 2.20 2.00 mean rank 13.30 17.70 15.77 15.23 statistics z=1.372 p=0.174 ns z=0.167 p=0.870 ns z = mann-whitney u test table 4: dun test for multiple comparisons of subgroups with control for salivary opg concentration. statistical test comparison mean rank z p-value sig. kruskall-wallis= 79.695 mean rank of control =45.50 alng 73.30 3.360 0.0031 hs degree of freedom=4 alnp 77.70 3.893 0.0004 hs p=0.000 hs opg 15.77 3.594 0.0013 hs opp 15.23 3.659 0.0010 hs z = mann-whitney u test table 5: the concentration of salivary tnf-α for study and control group with comparison of gingivitis and periodontitis between study groups. statistic group gingivitis periodontitis control aln op aln op aln op median 144.80 113.45 281.90 112.50 281.40 114.50 283.10 mean rank 45.50 15.50 75.50 8 23 8 23 statistic kruskall-wallis=79.125 p=0.000 hs z=4.667 p=0.000 hs z=4.667 p=0.000 hs kruskall-wallis h test, z = mann-whitney u test table 6: multiple comparisons among groups for salivary tnfα concentration groups z p sig. (control) x (aln) 4.45 0.000 hs (control) x (op) 4.45 0.000 hs (aln) x (op) 8.89 0.000 hs z = mann-whitney u test table 7: inter group comparisons of salivary tnf-α concentration. statistics inter groups comparisons subgroups alng alnp opg opp median 112.50 114.50 281.40 283.10 mean rank 14.30 16.70 13.53 17.47 statistics z=0.747 p=0.461 ns z=1.224 p=0.233 ns z = mann-whitney u test j bagh college dentistry vol. 30(2), june 2018 effect of alendronate oral and maxillofacial surgery and periodontics 20 table 8: dun test for multiple comparisons of subgroups with control for salivary tnf-α concentration. statistical test comparison mean rank z p-value sig. kruskall-wallis = 79.358 mean rank of control=45.50 alng 14.30 3.771 0.007 hs degree of freedom =4 alnp 16.70 3.480 0.002 hs p=0.000 hs opg 73.53 3.387 0.003 hs opp 77.47 3.863 0.000 hs z = mann-whitney u test table 9: spearman’s correlation coefficient (r) between salivary concentration of opg and tnfα in control and subgroups group r p significance control 0.112 0.554 ns alng 0.125 0.656 ns alnp 0.128 0.650 ns opg 0.483 0.068 ns opp 0.038 0.894 ns r= spearman's rank correlation coefficient test discussion the result of this study indicate significant increase in the level of salivary opg in aln group when compared to control and op group with highly difference between them and when compared gingivitis and periodontitis between two groups. osteoporosis is one of the risk factors that have been implicated in the progression of periodontal disease (13). a number of studies showed that there is a relationship between oral and systemic bone loss as well as an association of osteoporosis with periodontal diseases (14-16). estrogen hormone plays vital protective effect as antiresorptive agent on alveolar bone, since it improve opg production and decrease rankl expression, therefore estrogen deficiency after menopause considered as a key feature for development of osteoporosis(17), progression of periodontitis, alveolar bone resorption, and osteoporotic changes in the jaw(18). bone resorption and formation is regulated by the quantity of rankl and rank on the osteoclast surface and the presence of opg (5) that inhibit osteoclast function and prevent bone resorption through binding to rankl (19). any alteration to this regulation due to inflammatory conditions will lead to bone resorption like in case of osteoporosis (20), and periodontitis (21).alendronate has been revealed as modulators of osteoclast function and bone metabolism as a result it may inhibit the development of op due to reduction of bone loss (22). also it is able to produce mediators that inhibits osteoclastogenesis, moreover influences the rankl/opg system by increasing opg and declining rankl construction(23). the median value of salivary tnfα levels in this study showed significant increase in op group when compared to control and aln group with highly significant difference between them and in gingivitis and periodontitis between two group. tnf-α has an important role in increasing bone resorption following menopause, and the incidence of postmenopausal osteoporosis due to estrogen deficiency, since estrogen was reported to inhibit stimulation of osteoclast maturation by tnfα(24). proinflammatory cytokines such as tnf-α play vital function in inflammation and bone loss in many conditions like osteoporosis and periodontal disease (25). it was reported that tnf-𝛼 contributes to a basic responsibility in periodontal tissue destruction (26) and progression of periodontitis (27), also it is highly expressed in osteoporosis (28). all medications that involve inhibition of osteoclast function such as alendronate may be useful in inflammatory conditions (27) through decreasing cytokines production (29), since these cytokines essential for stimulation of rankl expression, which is crucial for osteoclastogenesis (30) and decreasing opg production (9). the cause of non-significant correlation in this study between salivary level of opg and tnfα may be due to reduced number of subject’s distribution in each group and apparent variations in disease activity between subgroups, and could be attributed to limited changes in alveolar bone during gingivitis as compared to periodontitis. in conclusion the present study provides evidence of association between periodontal diseases and osteoporosis. patients with osteoporosis had increased tnfα and decreased opg level compared to the patients under alendronate treatment, so these biochemical markers could be used for diagnosis and prediction of periodontal disease and osteoporosis. references 1. al habashneh, r., alchalabi, h .a., khader, y. s., hazza'a, a., odat, z. and johnson, g. k. association between periodontal disease and osteoporosis in postmenopausal women in jordan. journal of periodontology, 81, 1613-1621. 2010. 2. shum, i., leung, p.-c., kwok, a., corbet, e. f., orwoll, e. s., phipps, k. r. and jin, l. periodontal j bagh college dentistry vol. 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archives of oral biology, 57, 1537-1544. 2012. j bagh college dentistry vol. 30(2), june 2018 effect of alendronate oral and maxillofacial surgery and periodontics 22 الخالصة ان جميع الامراض التي تتصف بحدوث نخر وامتصاص النسيج العظمي كمرض هشاشة العظام والتهاب اللثة وانسجة ماحول الاسنان تشترك بنمط الخلفية: ن يا اكثر معام والذي يتميز بكون الخلايا الملتهمة للعظم هي الخلايا المسؤولة بشكل مطلق عن ذوبان العظم والذي يحدث عندما يكون نشاط هذه الخلا عظم بشكل نشاط الخلايا المسؤولة عن بناء العظم.يعتبر الاوستيوبروتجرين كمستلم وفخ يوجد بشكل ذائب ويعرف ب "حامي العظم" لكونه يمنع ذوبان ال الفا –مل تي ان اف عن طريق احتلاله لمكان ارتباط الرانك.ان عامفرط من خلال عمله كفخ للرانكل وبذلك يعمل على تثبيط نشاط الخلايا الملتهمة للعظم فيز تكون الخلايا يعتبر من السايتوكينات المؤدية لحدوث الالتهابات من خلال امتلاكه لدور مهم في تنظيم الجهاز المناعي وعملية ذوبان العظم عن طريق تح لخلايا الالتهامية مثل الرانكل بالاضافة لتأثيره على الملتهمة للعظم.ان عقار الندرونيت يعمل على التقليل من تكوين العوامل والسايتوكينات المحفزة لنشاط ا اج السايتوكينات زيادة افراز العامل المضاد للرانكل وهو الاوستيوبروتجرين من قبل الخلايا المسؤولة عن بناء العظم.بالاضافة لدوره في التقليل من انت البلعمية والذي يؤدي بدوره الى التقليل من الاستجابة -المشتقة من خط الخلايا الاحاديةالخلايا البلعمية وتحفيز موت الخلايا الفا بواسطة –كعامل تي ان اف للتاثير الالتهابي. الفا في النساء -تهدف الدراسة الى تقييم تاثير العلاج بعقار الندرونيت على المستويات اللعابية للاوستيوبروتجرين وعامل تي ان افاهداف الدراسة: للربط بين لايجاد اي احتمال ممكن كما تهدف الدراسة.والتهاب اللثة وانسجة ماحول الاسنان العظام مابعد سن اليأس المصابات بمرض هشاشة الفا في مجموعة الضبط ومجاميع الدراسة.-المستويات اللعابية للاوستيوبروتجرين وعامل تي ان اف سنة تم تقسيمهم الى ثلاثة (55-55ادراجها في هذه الدراسة تتراوح اعمارهم مابين )مشاركة من النساء فقط تم 09 المرضى,المواد وطرق العلاج: من النساع الاصحاء والحالة الصحية للثة وانسجة ماحول الاسنان صحية 09شخص لكل مجموعةوكالاتي:اولا:مجموعة الضبط تتكون من 09مجاميع اشهر)مجموعة 5-0لمدة صابة بهشاشة العظام تخضع لعلاج الندرونيتمن النساء الم 09ايضا.ثانيا:مجموعة الندرونيت تتكون من من النساء المصابة بمرض هشاشة العظم لاتخضع للعلاج بالالندرونيت او اي علاج اخر.تم تقسيم كل 09الالندرونيت(.ثالثا:مجموعة الهشاشة تتكون من وهي المجموعة الفرعية لالتهاب اللثة والمجموعة الفرعية مجموعة فرعيةلكل شخص 55تتكون من من المجموعتين الاخيرتين الى مجموعتين فرعيتين يوبروتجرين لالتهاب الانسجة الرابطة للاسنان المزمن.تم تجميع عينات اللعاب من جميع المشاركات في الدراسة وتم تحديد المستويات اللعابية للاوست الممتز المناعي.مرتبط الفا عن طريق نظام مقايسة الانزيم ال-وعامل تي ان اف الدراسة بان القيم الوسطية للمستويات اللعابية للاوستيوبروتجرين في مجموعة الالندرونيت هي الاعلى بين المجاميع تتبعها اظهرت نتائج هذهالنتائج: الفا فقد كانت اعلى قيم وسطية للمستويات اللعابية في -مجموعة الضبط وبعدها مجموعة الهشاشة باقل قيم وسطية.اما فيما يخص عامل تي ان اف احصائية معنوية عالية بين المجاميع تتبعها مجموعة الضبط ثم مجموعة الالندرونيت باقل مستويات لعابية.وكانت الفروق ذات دلالة مجموعة الهشاشة الفا حيث-افالدراسية ومجموعة الضبط.باستخدام معامل سبيرمان للارتباط تم تقييم العلاقات بين المستويات اللعابية للاوستيوبروتجرين وعامل تي ان . اظهرت النتائج وجود علاقات غير معنوية في كل المجاميع الفرعية من الممكن الاستنتاج بان المريضات اللواتي يعانين من هشاشة العظام يملكن مستوى عالي من عامل تي ان اف مع انخفاض مستوى الاستنتاج: فض من تي ان اف مع ارتفاع مستوى اوستيوبروتجرين..بالاضافة لذلك مستوى منخاوستيوبروتجرين بالمقارنة مع مجموعة الندرونيت والتي تكون ذات ماحول فان العلاج بعقار الندرونيت من الممكن ان يكون ذات مردود فعال ومفيد في المريضات التي تعاني من هشاشة العظام والتهاب اللثة وانسجة الاسنان مابعد سن اليأس. 17. lamia f.doc j bagh college dentistry vol. 25(1), march 2013 evaluation of the oral diagnosis 99 evaluation of the anterior loop of the mental nerve incidence and extension in different age groups in sulaimania city using digital panoramic imaging system lamia h. al-nakib, b.d.s., m.sc. (1) sarkawt khidhir rasul, b.d.s., m.sc. (2) abstract background: the anterior loop of mental nerve is commonly described as that part of the neurovascular bundle that transverses anterior and inferior to the mental foramen only to loop back to exit the mental foramen. the aim of the study is to evaluate the incidence and extension of anterior loop of mental nerve by using digital panoramic imaging system to avoid nerve damage during different surgical procedures in dentistry. materials and method: panoramic image was taken for all 400 patients and stored in the computer. then horizontal and vertical for the anterior loop extension when exist was measured and recorded in a special case sheet prepared for each subject. results: results indicated that out of 400 patients there were only 25 patients (6.25%) having anterior of the inferior alveolar nerve, 14 cases (56%) of them were males and 11 cases (44%) were females. the extension of the anterior loop of mental nerve was with wide range, for horizontal extension it was 1.3-6.36mm with significant difference between right and left sides, and with vertical extension was between 1.44 -5.98mm with no significant difference between the right and left sides. conclusion: no significant difference among subjects according to sex and the pattern of visualization of the anterior loop was shown. the anterior loop was visible in 6.25% of the dental panoramic radiographs with 3.5% for males and 2.75% for females. keywords: anterior loop, inferior alveolar nerve, panoramic image. (j bagh coll dentistry 2013; 25(1):99-104). introduction jalbout and tabourian (1) described anterior loop as “an extension of the inferior alveolar nerve, anterior to the mental foramen, prior to exiting the canal.” this means that the mental nerve, however, may extend beyond the mental foramen boundary as an intraosseous anterior loop. larger terminal branch of inferior alveolar nerve emerges from the mental foramen as the mental nerve. usually three nerve branches of approximately 1 mm in diameter come out of the mental foramen (2). hu and co-workers (3) investigated the topography of the mental nerve by dissecting 31 hemifaces of korean cadavers and divided this nerve based on the distribution area of the mental nerve as follows: angular, medial inferior labial, lateral inferior labial and mental branches. in most cases lateral inferior labial branch is separating from the angular branch. pogrel et al. (4) tested the hypothesis that some sensory innervations to the lower incisor teeth come from re-entry of the terminal branches of the mental nerve through the labial plate of the anterior mandible. (1)assistant professor. oral and maxillofacial radiologist, college of dentistry, university of baghdad, department of oral diagnosis. (2)specialist dentist, ministry of health, shahrazur general directorate of health they investigated 10 cadaver’s heads and concluded: three of 20 (15%) specimens showed unequivocal evidence of nerve re-entry into the labial plate. five specimens displayed strong evidence of nerve fibers re-entering the plate, but these were too fragile to be dissected through the periosteum without breaking. in 12 of 20 (60%) specimens, there were no branches identified that re-entered the bone plate. of the 8 specimens showing evidence of re-entry, 4 had substantial midline crossover. the finding indicates that branches of the mental nerve may re-enter the labial plate to supply the innervations from the contra lateral mental nerve. when inferior alveolar nerve arises from the mandibular canal and runs outward, upward and backward to open at the mf it is referred to as anterior loop (5), figures (1&2) several studies have shown wide variations in anterior loop length (5,7-9) , because of this, it is not advisable to assume that a fixed distance mesially from the mental foramen will be safe for the placement of an endosseous implant, even with the current recommendation of a safety margin of 4-6 mm (8,10) . the anterior loop cannot be seen clinically but can be detected in radiographs, which include dental panoramic radiographs, magnetic resonance imaging and computed tomography. dental panoramic radiographs are widely used to locate anatomic landmarks in planning for the placement of endoosseous implant in the jaw bones. the mental foramen is commonly used as j bagh college dentistry vol. 25(1), march 2013 evaluation of the oral diagnosis 100 the boundary of the inferior alveolar nerve in the mandible when planning for the placement of dental implants in the anterior mandible (11,12). figure 1: the anterior loop (al) of the mental nerve: length variations from the most anterior loop point to mental foramen. colours: blue = mic, red = mental canal(the anterior opening of the mandibular canal) . yellow = mandibular canal. 1 = length of the al (0.00 to 10 mm). (6) figure 2: panoramic radiograph showing extension of the mental nerve beyond the mental foramen boundary as an intra osseous anterior loop (arrows). (5) yosue and brooks (13) noted that an anterior loop (termed continuous type mental foramen in their study) was present in 21% of the 297 radiographs studied, while jacobs et al. (14) noted that it was present in 11% of panoramic radiographs, but was well visualized in only 3%. similarly, arzouman et al. (5) reported the structure in 12% of dental panoramic radiographs. solar et al. (12) detected al in 60% (22 of 37) of dissected cadaver mandibles, ranging in length from 0.5 to 5 mm (mean 1 mm). neiva et al. (15) were probing the mesial cortical wall of the mental canal in 22 cadavers and reported that al was present in 88% of the time and its length ranged from 1 to 11 mm (mean= 4.13 mm). rosenquist (11) detected anterior loop in 24% (15 of 58) of cadaveric mandibles with loop length variations from 0 to 1 mm. in 13 cadavers, the loop was 0.5 mm long, and two patients had a 1 mm length loop (mean = 0.15 mm). similarly, keiser et al. (16) found that there was no measurable al after exposing 1 cm of the nerve on both sides of the mf in 56 cadaveric mandibles. arzouman et al. (5) assessed 25 adult skulls using two panoramic machines both with and without radiopaque markers placed into the mandibular canal and anterior loop. the anterior loop was also measured directly using flexible tubing (2 mm in diameter). significantly fewer loops were detected in radiographs as compared with anatomic assessment (p < 0.001). a significant loop (> 2 mm) was identified in 92% to 96% of the direct measurements, whereas radiographs identified only 56% and 76% using different panoramic machines. the average length of the anterior loop based on direct measurements was 6.95 mm, whereas radiographic measurements were 3.18 mm and 3.45 mm using different panoramic machines. jacobs et al. (17) examined 230 spiral ct scans taken for preoperative planning of implant placement in the posterior mandible where the al appeared in 7 % of the cases. later jacobs with co-workers (14) examined 545 patients’ panoramic radiographs and found anterior loop in 11% of the cases, but was well visualized in only 3% of the detected loops. a study was undertaken by ngeow et al. (18) to determine al visibility on 97 dental panoramic radiographs in dentate subjects of various age groups. the anterior loop was visible in 39 (40.2%) dental panoramic radiographs encompassing 66 sites (34.4%). anterior loops were most often observed bilaterally, followed by on the right side only. the visibility of anterior loop reduced as the age of the subjects increased. no relationship was found between subject gender and the pattern of visualization of the anterior loop. authors then concluded that panoramic radiography is not sufficient for presurgical implant planning in the mental region and may need to be supplemented with other modalities such as ct for better visualization of the area. investigations that compared radiographic and cadaveric dissection data with respect to identifying the anterior loop reported that radiographic assessments result in a high percentage of false positive and false-negative findings. (5,8,9,19) varied results may be attributed to different criteria used to define the anterior loop, dissimilar diagnostic techniques, and diverse findings in patients greenstein and tarnow (20). for example, in above mentioned study of arzouman et al. (5), a significant loop (> 2 mm) was identified in 92% j bagh college dentistry vol. 25(1), march 2013 evaluation of the oral diagnosis 101 to 96% of the direct measurements, whereas radiographs identified only 56% and 76% using different panoramic machines. this can be explained by the finding that distance bone markers or tubing that penetrates the mandibular foramen (on dry skulls) cannot reliably be used to indicate the length of the anterior loop because these devices may penetrate into the mandibular inferior cortex .(8,11) bavitz et al. (19) reported that the anterior loop was present in 54% (17 of 35) of periapical radiographs taken of hemi mandibles. however, this finding was only confirmed by dissection in 11% (4 of 35) of the corresponding cadaver specimens. loop sizes ranged from 0.0 to 7.5 mm on periapical radiographs and from 0 to 1.0 mm among cadaver specimens. they concluded that damage to the mandibular nerve can be avoided if the distal surface of the most posterior implant is 1 mm anterior to the anterior border of the mandibular foramen. mardinger et al. (9) assessed 46 hemimandibles using periapical films and dissection with physical evaluation. anatomically, an anterior loop of the mn was observed in only 13 hemimandibles (28%). no correlation was found between the radiographic image and the anatomical shape of the loop. furthermore,in 70% of the radiographically diagnosed loops, 40% were not seen in anatomical examination. anatomically, 8 of 13 anterior loop were 0.4 to 1 mm long, 4 of 13 al were 1.1 to 2 mm, and one anterior loop was 2.19 mm. thus, 11% (5 of 46) of al were > 1 mm. kuzmanovic et al. (8) studied correlation between the visual interpretation of the panoramic radiographs and the anatomical dissection findings in a 22 cadaveric sample. the anterior loop of the mental canal was only identified in 6 panoramic radiographs (27%) (range: 0.5-3 mm) and 8 (35%) anatomical measurements. authors then concluded that clinicians should not rely on panoramic radiographs for identifying the anterior loop of the mn during implant treatment planning. however, a safe guideline of 4 mm, from the most anterior point of the mf, is recommended for implant treatment planning based upon the anatomical findings. more accurate anterior loop assessments were obtained by uchida et al. (21) who used cone beam computed tomography in 4 cadavers and dissected 71 cadavers. the anatomic measurements revealed mean anterior loop size of 1.9 ± 1.7 mm and range 0.0 to 9.0 mm. the average discrepancies between cbct and anatomic measurements were 0.06 mm or less. materials and method the sample consisted of retrospective and prospective study of 400 male and female dentate patients’ panoramic images collected from panoramic images saved in the archives and new patients attending the radiologic department of the school of dentistry and piramerd dental hospital. the patients were subdivided according to age as the following: 1. 20-29 years 2. 30-39 years 3. 40-49 years 4. 50 & more panoramic image was done for all 400 patients and stored in the computer. they were subjected to contrast and density enhancement and restored for further evaluation by autocad program. all the information and measurements were recorded in a special form prepared for each subject, selected images were clear to be investigated and without any jaw fracture or other pathological conditions affecting the area of interest. the horizontal extension was done by measuring the distance between the tangent to the anterior border of mental foramen to the parallel tangent to the posterior border of the anterior loop was measured for the right side (d1) and for the left side (d2).( figure 3). while the vertical extension was done by measuring the distance between the tangent to the inferior border of the mental foramen and the parallel line which is tangent the upper border of the anterior loop of mental nerve was measured for the right side (d3) and for the left side (d4) as seen in figure 4. results and discussion the current study used panoramic image modality as it is the most routinely used tool in implant treatment planning. moreover, no similar study has been performed on a sulaimani population. the loop was present in 6.25% of all subjects (400 subjects). this is lower than the incidence reported by arzourman et al. (5) which was 12%,, yosue and brooks (8) 21%, and kuzmanovic et al. (8) 27%. their higher incidence of visualization may be related to the use of newer panoramic machines providing higher resolution radiographs, while jacobs et al. (14) noted that the anterior loop of mental nerve was well visualized in only 3% .one possible explanation for the underestimation of the anterior loop is because it is an intermedullary structure that is located in an area with relatively thick cortical plates, hence making it difficult to distinguish in plain films (5). j bagh college dentistry vol. 25(1), march 2013 evaluation of the oral diagnosis 102 the difficulty in identifying the mental foramen and anterior loop has been attributed to poor radiographs or bone quality, and the inability to distinguish these structures from the trabecular pattern (8,13). patient position and technician errors affect the quality of the radiograph. objects that are outside the section or plane of focus (in the focal trough) will result in distorted or obscured images (22). the incidence of the anterior loop was noted as 56% in males and 44% in females as shown in table1. the anterior loop was more commonly identified in males than in female, while wei et al. (23) showed that no anterior loop was visible in the majority (79%) of female subjects aged ≥ 50, and in all male subjects aged ≥ 50 of malay patients. in female and male subjects aged 20 – 29, there was no anterior loop of mental nerve (table1), while wei et al. (23) showed that in female subjects the anterior loop was most commonly visible bilaterally (in 43% of radiographs) for the same age group. in contrast, for the male subjects of the same age, the anterior loop was most commonly visible on the right side (in 29% of radiographs). another 24% of male subjects in this age group exhibited an anterior loop on both sides. in the subjects aged 30 – 39 (second agegroup), the anterior loop was more commonly identified in male than in female. only one subject (12.5%) of male and female subjects of this age group presented with an anterior loop on both sides and confined to the right side in 3 (37.5%) subjects in males and 2 (25%) subjects in females while on the left side of the second agegroup there were 4(50%)subjects in males and 2 (25%) subjects in female having anterior loop of mental nerve (table1), however wei et al. (23) showed that there was three-quarters (75%) of male subjects of this age group presented with an anterior loop on both sides. in comparison, only a quarter (25%) of female subjects showed an anterior loop of mental nerve, this was bilateral in 2 (16.7%) subjects, and confined to the right side in 1 (8.3%) subject. in the subjects aged 40-49 (third age-group) ), the anterior loop was more commonly identified in males than in females , on both sides there was only 1 (12.5%) subject in both sexes having anterior loop of mental nerve, on the right side 3 (37.5%) subjects in males and 2 (25%) subjects in females having anterior loop of mental nerve, on the left side there were 4(50%) subjects in males and 3 (37.5%) subjects in females having anterior loop of mental nerve, while wei et al. (23) showed that the percentage of subjects with at least one visible anterior loop was almost equal between genders in subjects aged 40 – 49 years. in subjects aged 50 and more (forth age-group) the anterior loop was more commonly identified in males than in females. there was increased percentage of the incidence of anterior loop of mental nerve as the age of subjects increased (table1). while wei et al. (23) showed that as the age of subjects increased, it became more difficult to identify an anterior loop in the radiographs. they were unable to determine the presence of an anterior loop in almost three-quarters of radiographs in both men and women aged 40 – 49 years. similarly, no anterior loop was visible in the majority (79%) of female subjects aged ≥50, and in all male subjects aged ≥50. with this study, while unable to confirm the presence of the anterior loop in young subjects (first age-group), it cannot be definitively show that these subjects do not have anterior loops. only a larger study using a superior imaging modality such as computed tomography may be able to improve the findings of this study. the horizontal extension of anterior loop of mental nerve was noted as (mean=3.07 mm) ranging from 1.3mm to 6.36mm and the vertical extension of anterior loop of mental nerve was noted as (mean=3.27) ranging from 1.44mm to 5.98mm (table2). this agrees with several studies which have shown wide variations in anterior loop length. (5,7-9) it is not advisable to assume that a fixed distance mesially from the mental foramen will be safe for the placement of an endosseous implant, even with the current recommendation of a safety margin of 4-6 mm. (8,10) more accurate of anterior loop assessments were obtained by uchida et al. (21) who used cone beam computed tomography in 4 cadavers and dissected 71 cadavers. the anatomic measurements revealed mean anterior loop size of 1.9 ± 1.7 mm and range 0.0 to 9.0 mm. figure 3: the horizontal extension of anterior loop of mental nerve j bagh college dentistry vol. 25(1), march 2013 evaluation of the oral diagnosis 103 figure 4: the vertical extension of anterior loop of mental nerve table 1: the frequency distribution and percentage of the total cases with anterior loop of mental nerve and its vertical and horizontal dimensions. no. %of positive cases % of population sex total 25 100 6.25 male 14 56 female 11 44 age groups 20-29 years old 0 0 30-39 years old 5 20 40-49 years old 10 40 50 years old & more 10 40 sides right 14 56 3.5 left 19 76 4.75 both 8 32 2 total 33 100 table 2: horizontal and vertical measurements of anterior loop of mental nerve with minimum and maximum values horizon tal and vertical measure ment n o. mini mum maxi mum mean ±sd test ed gro ups p horizo ntal d1 14 1.3 4.8 2.77± 0.97 d1 vs d2 0. 12 d2 19 1.73 6.36 3.37± 1.15 vertic al d3 14 1.44 5.25 3.17± 1.12 d3 vs d4 0. 58 d4 19 2.02 5.98 3.36± 1.02 references 1. jalbout z, tabourian g. glossary of implant dentistry. upper montclair, nj: international congress of oral implantologists; 2004; 16. 2. mraiwa n, jacobs r, moerman p. presence and course of the incisive canal in the human mandibular interforaminal region: two dimensional imaging versus anatomical observations. surg radiol anat 2003; 25: 416-23. 3. hu ks, yun hs, hur ms, kwon hj, abe s, kim hj branching patterns and intraosseous course of the mental nerve. j oral maxillofac surg 2007; 65: 228894. 4. pogrel ma, dorfman d, fallah h. the anatomic structure of the inferior alveolar neurovascular bundle in the third molar region. j oral maxillofac surg 2009; 67:2452-4. 5. arzouman mj, otis l, kipnis v, levine d. observations of the anterior loop of the inferior alveolar canal. int j oral maxillofac implants 1993; 8: 295300. 6. juodzbalys g, wang hl, sabalys g. anatomy of mandibular vital structures. part ii: mandibular incisive canal, mental foramen and associated neurovascular bundles in relation with dental implantology. j oral maxillofac res 2010; 1(1): e3. 7. uchida y, yamashita y, goto m, hanihara t. measurement of anterior loop length for the mandibular canal and diameter of the mandibular incisive canal to avoid nerve damage when installing endosseous implants in the interforaminal region. j oral maxillofac surg 2007; 65: 1772-9. 8. kuzmanovic dv, payne ag, kieser ja, dias gj. anterior loop of the mental nerve: a morphological and radiographic study. clin oral implants res 2003; 14: 464-71. 9. mardinger o, chaushu g, arensburg b, taicher s, kaffe i. anterior loop of the mental canal: an anatomical radiologic study. implant dent 2000; 9:120-5. 10. babbush ca. transpositioning and repositioning the inferior alveolar and mental nerves in conjunction with endosteal implant reconstruction. periodontol 2000 1998; 17:183-90. 11. rosenquist, b. is there an anterior loop of the inferior alveolar nerve? int j periodontics restorative dent1996; 16: 41-5. 12. solar p, ulm c, frey g, matejka m. a classification of the intraosseous paths of the mental nerve. int j oral maxillofac implants 1994; 9: 339-344. 13. yosue t, brooks sl. the appearance of mental foramina on panoramic and periapical radiographs.ii. experimental evaluation. oral surg oral med oral pathol 1989; 68: 488-492. 14. jacobs r, mraiwa n, van steenberghe d, sanderink g, quirynen m. appearance of the mandibular incisive canal on panoramic radiographs. surg radiol anat 2004; 26: 329-333. 15. neiva rf, gapski r, wang hl. morphometric analysis of implant-related anatomy in caucasian skulls. j periodontol 2004; 75: 1061-7. 16. kieser j, kuzmanovic d, payne a, dennison j, herbison p. patterns of emergence of the human mental nerve. arch oral biol 2002; 47:743-7. 17. jacobs r, mraiwa n, van steenberghe d, gimbals f, quirynen m. appearance, location, course, and morphology of the mandibular incisive canal: an assessj bagh college dentistry vol. 25(1), march 2013 evaluation of the oral diagnosis 104 ment on spiral ct scan. dentomaxillofac radiol 2002; 31: 322-7. 18. ngeow wc, dionysius dd, ishak h, nambiar p. a radiographic study on the visualization of the anterior loop in dentate subjects of different age groups. oral sci 2009; 51: 231-7. 19. bavitz jb, ham sd, hansen ca, lang m. an anatomical study of mental neurovascular bundleimplant relationships. int j oral maxillofac implants 1993; 8: 563-567. 20. greenstein g, tarnow d. the mental foramen and nerve: clinical and anatomical factors related to dental implant placement: a literature review. j periodontol 2006; 77: 1933-43. 21. uchida y, noguchi n, goto m, yamashita y, hanihara t. measurement of anterior loop length for the mandibular canal and diameter of the mandibular incisive canal to avoid nerve damage when installing endosseous implants in the interforaminal region: a second attempt introducing cone beam computed tomography. j oral maxillofac surg 2009; 67:74450. 22. dharmar s. locating the mandibular canal in panoramic radiographs. int j oral maxillofac implants. 1997; 12: 113-117. 23. wei cn, dionetta dd, hayati i, phrabhakaran na. radiographic study on the visualization of the anterior loop in dentate subjects of different age groups. j oral science 2009; 51: 231-7 nagham f.doc j bagh college dentistry vol. 25(4), december 2013 inhibition of bacterial restorative dentistry 26 inhibition of bacterial growth around gutta percha cones by different antimicrobial solutions using antibiotic sensitivity test (an in vitro study) nagham a. al-hyali, b.d.s., m.sc. (1) abstract background: decontamination of gutta percha cones was important factor for success of root canal treatment. the aim of the present in vitro study was to identify and to compare the antimicrobial effect of following disinfection solutions: 0.2% chlorhexidine gluconate, iodine, tetracycline hydrochloride solution, edta & formocresol mixed with zinc oxide eugenol, on e faecalis, e coli and candida albicans using sensitivity test materials and methods: three types of microorganisms were isolated from infected root canals (e faecalis, e coli and candida albicans) and cultured on mueller hinton agar petri-dishes. disinfection of gutta percha cones done by immersion in six disinfection solutions (six groups), the groups are: distill water (used as control group), 0.2% chlorhexidine gluconate, iodine, tetracycline hydrochloride solution, edta & formocresol mixed with zinc oxide eugenol. the immersion times were 5 min. and the incubation was aerobically at 37 °c for 24 hr. for bacterial species and at 28°c for 48 hr. for candida albicans. after incubation, zones of inhibition (no growth of bacteria) were examined around the gutta percha cones & diameters of the zones were measured with a boley gauge. the means of inhibition zones for each group were measures and statistically analyzed among groups using anova and lsd tests at 0.05 significance level. results: there is highly significant differences (p=0.000) among all the tested groups. 0.2% chlorhexidine gluconate showed the maximum antibacterial efficacy (broader zones of inhibition) against e faecalis. compound of formocresol + zinc oxide eugenol showed the maximum antibacterial efficacy against candida albicans, and e coli. the minimum antibacterial efficacy against candida albicans occurred with tetracycline group, while against e faecalis and e coli occurred with edta group conclusion: all the tested materials had antibacterial efficacy against candida albicans, e faecalis and e coli; but chlorhexidine gluconate and compound of formocresol & zinc oxide eugenol, are more effective agents for a rapid disinfection of gutta-percha cones in five minutes. keywords: anaerobic bacteria, chlorhexidine, edta, mueller hinton agar and formocresol. (j bagh coll dentistry 2013; 25(4):26-32). introduction there is direct relationship between bacterial infection of dental pulp and periapical lesions formation. bacterial infection of dental pulp results in pulpal destruction and subsequently stimulates an inflammatory cell response and destruction of bone in the periapical area.1 the main goal of endodontic therapy is to eliminate microorganisms from the root canal system and the prevention of subsequent reinfection2. although the majority of bacteria are eliminated by biomechanical preparation of root canal space, a few microorganisms might still survive, thus using of intracanal medication and filling materials with antimicrobial and sealing properties are of essential importance, to avoid the growth of microorganisms3. in endodontic practice, the elimination or significant reduction of microorganisms from the root canal by chemo-mechanical preparation is an essential factor in successful treatment. care must be taken during this procedure to prevent contamination of instruments and filling materials, to avoid root canal cross-infection4, 5. (1)assistant lecturer. department of conservative dentistry. college of dentistry, university of bghdad. the studies found that gutta-percha cones (gpc) taken directly from the manufacturer's sealed package harbored cultivable microorganisms. while the numbers of these microorganisms were quite low at the time of opening of the package, and clinical use of the packages increased the number of microorganisms contaminating the (gpc), so preventive procedures needed including rapid chair side decontamination of the (gpc) with chemical disinfectants.5 several tests were used to observe the antimicrobial activity of chemical decontaminants of gpc, but there is no consensus for the best method. in order to better investigate this matter, we carried out disk diffusion antibiotic sensitivity testing to investigate the antimicrobial activity of several types of medicated solutions. materials and methods case selection this in vitro study examined 20 patients who attended the clinic of college of dentistry, university of baghdad, conservative department. their ages ranged from 20 to 40 years with periapical pathology. a detailed medical and dental history was obtained from each patient. none of the patients had received antibiotic treatment during the previous 3 months, and none j bagh college dentistry vol. 25(4), december 2013 inhibition of bacterial restorative dentistry 27 had any systemic disease. the lesion diagnosed clinically and confirmed by radiographic examination. isolation of bacteria the whole procedure of culturing was undertaken under strict aseptic conditions. the operating field was isolated using rubber dam and disinfected with 10% povidone iodine solution in order to avoid interference with isolation of bacteria. all coronal restorations and carious lesion were removed from the infected teeth. then access cavity was prepared with a new sterile carbide fissure bur. new sterile files and barbed broach inserted into the root canals up to the apical foramina (the working length confirmed by diagnostic x-ray) to remove the content of root canals, followed by enlargement of the canals with minimal instrumentation without use of any irrigant. sterile paper points were introduced in to the full length of the canals and retained in the canals for 1min. for microbiological sampling.6 the paper points were immediately introduced inside amice transporting media to preserved collected bacteria from dyeing and sealing the bottle tightly until send to the central public health laboratory for isolation of bacterial species within 4 hrs only. identification of bacterial species broth culture suspensions of bacteria and c. albicans were adjusted to no. 0.5 mcfarland standard (approximately 1.5 × 108 cells/ml), and 100 ml aliquots of each microbial suspension were dispersed on the surface of agar plates then transferred to specific fluid growth media before the experiment. three types of agers used for isolation of bacteria. blood agar for isolation of gram +ve bacteria, macconkey agar for isolation of gram -ve bacteria (both agers incubated at 37°c for 24 hrs), and sabouraud agar for candida albicans (candida incubated at 28°c for 48 hrs.)7 fig.1. from these mixed colonies, single bacterial or fungal species can be identified based on their morphological (size/shape/colour) differences with the help of hand lens. each type of colony was picked up and subcultured aerobically as well as anaerobically. only those organisms which failed to grow aerobically were taken as anaerobes. if no growth was obtained then re-incubation was done. microorganisms were identified by biochemical test using api. api 20e for distinguishing of gram -ve bacteria, api strep for distinguishing of gram -ve bacteria and api candida for distinguishing of candida albican. candida albicans and two types of anaerobic bacterial strains were isolated from the infected canals and pure cultures of them were prepared: 1. enterococcus faecalis, e. faecalis (gram +ve bacteria). 2. escherichia coli, e coli (gram-ve bacteria). bacterial subculturing after identification of microorganism, each type of microorganism subcultured onto the following agars: blood agar for enterococcus faecalis, macconkey agar for e coli (both agers incubated at 37°c for 24 hrs), and sabouraud agar for candida albicans, incubated at 28°c for 48 hrs inoculated on three types of agers using streaking microbiology technique, the incubator used for performance of the test. decontamination of gutta percha and growth inhibition zones measurement before the experiment each gutta percha cones (diadent/size 90) were immersed completely for one hr. in 2 ml of sterile water in a test tube to release for example the free iodine, because gutta-percha cones remains inert until it comes in contact with tissue fluids8. then gutta-percha cones immersed in six disinfection solutions for 5 min. (types of disinfection solutions and their manufacturer were mentioned in table 1 & fig.2). pure culture of each microorganism inoculated on mueller hinton agar petri-dishes using (kirbybauer antibiotic testing or named disk diffusion antibiotic sensitivity testing) 7,9 and two gpc from the same group placed on agar petri-dishes and incubated aerobically at 37 °c for 24 hr. for bacterial species and at 28°c for 48 hr. for candida albicans. after incubation, zones of inhibition (no growth of bacteria) were examined figure 1: types of agers used for micobiological acandida albicans inoculated on sabouraud agar be coli inoculated on macconkey agar ce faecalis inoculated on blood agar. j bagh college dentistry vol. 25(4), december 2013 inhibition of bacterial restorative dentistry 28 around the gpc (fig. 3 & 4). these appeared as clear, circular halos surrounding the wells. diameters of the zones around gutta percha were measured with a boley gauge by one investigator (minus the diameter of the gutta percha). experiments were repeated (n=10) and the mean value was determined. it should be noted that the inhibition zone size diameters did not necessarily represent absolute inhibitory values of a particular agent/species combination, but rather general indications of the agents' potency or lack thereof in relation to other materials. in addition, slight variations in zone sizes may have resulted from errors made in judgment of well depth and angulations in the agar.7 measurements of inhibitory zone were ranked into five inhibition categories according to the proportional distribution of the data set.9 (see table 2) table 1: disinfection solutions used in study and their manufacturers materials manufacturers chlorhexidine gluconate 0.2% corsodyl mint mouth wash, glaxosmithkline, uk iodine media co., syria tetracycline hydrochloride capsules (50mg/ml) 250 mg, samacycline s.d.i.-iraq edta glyde syringe kit, a 0901, dentsply maillefer , usa tricresol & formalin tricresol 35%, formaldehyde 40% , pd, switzerland zinc oxide 99.86% zinc oxide, zomed, dubai, uae eugenol deepak, usa table 2: five inhibition categories according to the proportional distribution of the data set rank range of zone diameters(mm) no 2 weak 1.4-6.2 medium 6.3-10.3 medium strong 10.4-26.8 strong antimicrobial activity > 26.8 sample grouping thirteen gutta percha cones (gpc) disinfected by immersion in each group, then these 30 cones subdivided into 3 subgroups according to types of microorganisms tested in this study (candida albicans, e faecalis and e coli subgroups). group 1(control): 30 gpc immersed in distill water. group 2(chx): 30 gpc immersed in chlorhexidine gluconate 0.2 % . figure 2: the disinfection materials used in study. figure 3: inhibition zones (no growth of e. faecalis) around gutta percha cones disinfected by chlorhexidine gluconate 0.2 % on mueller hinton agar petri-dishes figure 4: six groups showed inhibition growth zone of candida albicans around gpc. j bagh college dentistry vol. 25(4), december 2013 inhibition of bacterial restorative dentistry 29 group 3(iodine): 30 gpc immersed in povidone – iodine. group 4(tetracycline): 30 gpc immersed in tetracycline hcl 250 mg capsule /5ml distill water = 50 mg/ ml. group 5(edta): 30 gpc immersed in 17% edta. group 6(fc+ zoe): 30 gpc immersed in formocresol + zinc oxide eugenol. formocresol: zno: eugenol =2 drops: 1 scoop:6 drops = 0.02 cc: 0.2 g:0.06cc. (see table 1 & fig. 2) statistical analysis all statistical analyses were carried out using spss statistical software (version 19.0, spss, chicago, il, usa). after data collection, mean values and standard deviations were calculated for all groups and subgroups. one way analysis of variance (anova) was performed among the experimental groups to determine if there is any statically significant difference among the groups. when a significant difference was found, least significant difference (lsd) test was done to find where is the significance occurs. the mean difference is significant at the 0.05 level. results the inhibitory potential of each material was categorized as strong, medium strong, medium, weak, or non-inhibitory depending on the average size of the zones. mean of inhibitory zone size for each groups and their categories, standard deviation (sd) presented in table 3. the result found that, control group showed no inhibition activity against the tested microorganism, while other groups showed medium strong or medium inhibition activity; and only edta materials showed weak effect on candida albicans (see table 3 & fig 4), with highly significant differences (hs) among the groups revealed by one way anova test (p = 0.000) as shown in tables 4. further investigation using lsd test showed that a statistically high significant differences (p<0.05) among the groups and with three tested microorganism (table 5). table 3: mean of inhibitory zone size, table 3: mean of inhibitory zone size, categories & standard deviation for each groups and their subgroups. group supgroup mean zone categories sd control e. feacalis 0.00 no inhibition 0.00 e. coli 0.00 no inhibition 0.00 candida albicans 0.00 no inhibition 0.00 chx e. feacalis 18.2 medium strong 0.63 e. coli 17.2 medium strong 0.37 candida albicans 13.4 medium strong 0.51 iodine e. feacalis 17.3 medium strong 0.49 e. coli 13.2 medium strong 0.5 candida albicans 14.8 medium strong 0.5 tetra. e. feacalis 9.1 medium 0.42 e. coli 12.6 medium strong 0.48 candida albicans 11.1 medium strong 0.69 edta e. feacalis 5.8 weak 0.23 e. coli 11.4 medium strong 0.37 candida albicans 12.3 medium medium 0.32 fc+ zoe e. feacalis 10.2 medium 0.27 e. coli 25.8 medium strong 1.53 candida albicans 27.6 medium strong 0.38 table 4: one way anova test among the six groups and for each subgroup. subgroup fvalue p -value e. feacalis 60.36 0.000 e. coli 93.61 0.000 candida albicans 81.95 0.000 figure 4: bar chart shows the differences in mean of inhibitory zone size according to types of disinfection solution used in the study. j bagh college dentistry vol. 25(4), december 2013 inhibition of bacterial restorative dentistry 30 table 5: lsd test among the groups and for each tested microorganism. groups p. value e. feacalis e. coli candida albicans control vs. chx, iodine, tetra., edta and fc+zoe 0.000 hs 0.000 hs 0.000 hs chx vs. iodine, tetra., edta and fc+ zoe iodine vs. tetra, edta and fc+zoe. tetra. vs. edta and fc+ zoe. edta vs. fc+zoe significant at the 0.05 level. discussion the major causes of pulpal and periapical diseases are living and nonliving irritants. the nonliving group includes mechanical, thermal and chemical irritants. the living irritants include various microorganisms including bacteria, yeasts and viruses. when pathological changes occur in the dental pulp, the root canal space acquires the ability to harbor various species of bacteria, along with their toxins and by products.8 two of the main goals of endodontic therapy are: the elimination of microorganisms from the root canal system and the prevention of subsequent reinfection. the most common types of root canal filling materials used were gutta percha. commercially available gpc come in presterilized packages. however, some studies have shown that 5-8% of the cones from sealed packages can be contaminated with bacteria 5-10. also, gpc can be contaminated by handling, when exposed to the dental operatory environment and during storage 11. so for preventing crosscontamination of the root canal during endodontic treatment, it has been recommended that guttapercha cones be sterilized prior to obturation. gutta-percha cones cannot be sterilized by conventional autoclaving; different chemicals have been suggested for use in decontamination of cones. in this study five types of solutions used for decontamination of gutta percha against three bacterial strains: e. faecalis, e. coli and candida albicans; which are frequently isolated during routine endodontic treatment of an infected root or from teeth with periapical pathology.8-12 in particular, e. faecalis is gram-positive facultative anaerobic coccus that are a normal part of human intestinal flora. e. faecalis cells are ovoid in appearance and can grow in single cells and in chains. they have been implicated in persistent root canal infections included failed cases and has been used in several previous studies on the efficacy of endodontic irrigants, its characterized by high resistance to a wide range of antimicrobial agents and causes reinfection of root canal .13-14 while e. coli is gram-negative, facultative anaerobic and non-sporulating, rodshaped cells.15 candida albicans is a diploid fungus that grows both as yeast and filamentous cells and a causal agent of opportunistic oral and genital infections in humans.16 in this study the results found that distill water showed no antimicrobial activity against e. faecalis, e. coli and candida albicans, no inhibition of growth occurred with distill water (control group). (table 3 & fig 4). chlorhexidine has broad spectrum of antimicrobial activity, kills vegetative bacteria by disrupting the membrane integrity and inducing the precipitation of the cytoplasm. chx used either as irrigant solution or as an intracanal medication and it's found to be effective at 15 sec. to 2 hrs in direct contact with infected gpc17. resent form of gutta percha matrix embedded with 5% chlorhexidine diacetate. chlorhexidine gutta percha showed strong antimicrobial activity on e.faecalis.10 (table 3) in this study 0.2 % chlorhexidine gluconate solution (chx) used for measurement of chx effect on bacteria by using antibiotic sensitivity test, the result found medium strong inhibition effect on the three tested microorganism. this result agree with gomes et al 10 they found that chlorhexidine in liquid form was most effected in disinfection of gpc contaminated by (e. faecalis, streptococcus sanguis, aerobes staphylococcus aureus and candida albicans) than gel form. also they found that chx, at all concentrations and presentation forms tested, was not effective in eliminating bacillus subtilis spores on gpc, even after 72 hours of contact. iodine as antimicrobial agent showed growth inhibition lower than chx and higher than tetracycline solution with higher effect on e. faecalis, and lower effect on e. coli (table 3), this agree with bodrumlu and alaçam 7; they found that gpc impregnated with povidone– iodine inhibited all bacterial strains (e. faecalis, pseudomonas aeruginosa. staph. aureus, e. coli and candida albicans) for up to 72 hours and when compared with regular gpc, no inhibition zones were seen around. also they found that gpc medicated with tetracycline inhibited the growth j bagh college dentistry vol. 25(4), december 2013 inhibition of bacterial restorative dentistry 31 of all bacteria over 24 hours, but in some cases these effects did not continue over longer periods, specifically against e. coli and p. aeruginosa, its disappeared by 48 and 72 hours. tetracycline, a broad spectrum antibiotic has been widely used in the treatment of various endodontic infections. the gpc impregnated with tetracycline acts as an antimicrobial reservoir that is capable of diffusing onto the surface of the gutta percha, thereby inhibiting colonization of bacteria on the gpc and within the root canals. the important fact is that tetracycline can become incorporated into calcified structures due to its ability to bind to mineralized dentinal matrices and its slow release from dentin makes its antimicrobial effect substantive. moreover tetracycline is stable in an acid environment thereby making it effective in the inflamed area of the root canal periapex, where most alkaline type antimicrobials agents neutralize, this a distinct advantage for the tetracyclines18. in this study tetracycline solution (250mg/ 5ml distill water) used as antimicrobial agent for rapid disinfection of gpc by immersion the cones in tetracycline solution for 5 min. then the cones incubated in agers containing the tested microorganisms and the results found, tetracycline has medium strong disinfection effect on candida albicans and e.coli but medium effect on e. faecalis. (table 3). vijay & shashikala 19 found that tetracycline impregnated gpc showed the maximum antimicrobial efficacy on e.faecalis compared to chlorhexidine impregnated gutta percha when used as an intracanal medicament. but in this study the effect is lower than chlorhexidine solution; this may be related to lower concentration of tetracycline solution used. edta is organic acid (ethylene diaminetetraacetic acid) which eliminates the mineral part of pulp tissue 4, 20. it is advised to use of edta from the beginning of the preparation in order to eliminate the mineral layer before its thickening and condensing it inside the canal systems which will close the entrances of lateral and accessory canals and dentinal tubules, and facilitates the flow of the different irrigants such as naocl or chlorhexidine in the lateral canals permitting a chemical preparation of all the endodontic system.21 edta showed lower growth inhibition compared with other tested group against all tested microorganism. also, its only group that causes weak growth inhibition of e. faecalis, followed by e. coli and higher effect on candida albicans. (table 3). in agreement with fidalgo et al 22 found that 17% edta was more effective than 0.5% naocl against candida albicans and staphylococcus aureus in group 6 (fc+ zoe), the mean of inhibiton zones showed that, it's the most efficient material in growth inhibition of candida albicans and e.coli (medium strong effect) (table 3), but their effect on e. faecalis was medium. tchaou et al. 9 used this mixture as root canal filling material and they tested its antimicrobial activity against 21 microbial species including anaerobic gram +ve, anaerobic gram -ve, facultative anaerobic gram +ve and facultative anaerobic gram -ve. they found that fc+zoe mixture inhibited all tested strain. so using this mixture was highly effected on disinfection of tested bacteria but further investigation needed to measure its effect on physical properties of gutta percha and on sealer material, when used as rapid agent for decontamination of gutta perch. however, in vitro tests such as the ones performed here can only indicate the potential of some materials to inhibit microbial growth and metabolism in the local microenvironment of the root canal; but further studies in vivo needed, with change of the experimental methods. references 1. haapasolo m. bacteroids in dental root canal infections. endod dent traumatol 1989; 5: 1 – 10. 2. bodrumlu e, alacam t, semiz m. the antimicrobial and antifungal efficacy of tetracyclineintegrated gutta-percha. indian j dent res 2008; 19(2): 112-5. 3. schafer e, bossmann k. antimicrobial efficacy of chlorhexidine and two calcium hydroxide formulations against enterococcus faecalis. j endod 2005; 31(1): 536. 4. siqueira jr, pereira da silva chf, lopes hp. effectiveness of four chemical solutions in eliminating bacillus subtilis spores on gutta-percha cones. endod dent traumatol 1998; 14: 124-6 5. kayaoglui g, güreli m, ömürlüi h, gonca beki z, sadiki b. examination of gutta-percha cones for microbial contamination during chemical use. j appl oral sci 2009; 17: 23 (ivsl). 6. ercan e, dulgergil t, yavuz i. the effects of antibacterial solutions on microorganisms isolated from infected root canals. biotechnol & biotechnol eq. 20/1/2006/1. 149-156. 7. bodrumlu e, alaçam t. evaluation of antimicrobial and antifungal effects of iodoform-integrating gutta-percha. cand dent assoc 2006; 72(8):733-733d. 8. siqueira jr, rôças, in. endodontic microbiology in: endodontics: principles and practice. 4th ed. philadelphia: saunders; 2009. 9. tchaou w, turng bf, glenn e, james a. & coil j. inhibition of pure cultures of oral bacteria by root canal filling materials. american acad ped dent 1996; 18(7): 444-9. 10. gomes b, vianna m, matsumoto c. disinfection of gutta-percha cones with chlorhexidine and sodium hypochlorite. oral surg oral med endod 2005; 100(4): 512. j bagh college dentistry vol. 25(4), december 2013 inhibition of bacterial restorative dentistry 32 11. da motta p, de figueiredo c, maltos s. efficacy of chemical sterilization and storage conditions of guttapercha cones. int endod j 2001; 34(6): 435. 12. zoletti g, siqueira j, santos k. identification of enterococcus faecalis in root filled teeth with or without periradicular lesions by culture dependent and independent approaches. cand dent assoc 2006; 32(8): 7226. 13. rani a, chopra a. isolation and identification of root canal bacteria from symptomatic non vital teeth with periapical pathosis. int endod j 2003; 36: 1-11. 14. peciuliene v, maneliene r, balcikonyte e, drukteinis s, rutkunas v. microorganisms in root canal infections: a review. stomatologija j baltic dental & maxillofacial 2008; 10(1): 4-9. 15. facts about e. coli: dimensions, as discussed in bacteria: diversity of structure of bacteria: – britannica online encyclopedia". britannica.com. retrieved 2011-06-05. 16. denfert c, hube b. candida. comparative and functional genomics. caister academic press 2007. isbn 978-1-904455-13-4. 17. jenkins s, addy m, wade w. the mechanism of action of chlorhexidine. a study of plaque growth on enamel inserts in vivo. j clin periodontol 1988; 15: 415-24. 18. martin, howard. antibiotic/medicated gutta percha point. us patent 6, 602,516; 2003. 19. vijay r, shashikala k. evaluation of antimicrobial efficacy of medicated gutta percha against enterococcus faecalis (an in vitro study. arch dental sci 2010; (1)1; 36-40 20. taha my, al-sabawi na, shehab ey. rapid decontamination of gutta percha cones using different chemical agents. al–rafidain dent j 2010; 10(1): 30-7. 21. bystrom a, sundqvist g. the antibacterial action of sodium hypochlorite and edta in 60 cases of endodontic therapy. int endod j 1985; 18: 35–40. 22. fidalgo tks, barcelos r, portela mb, soares rma, gleiser r, silva-filho fc. inhibitory activity of root canal irrigants against candida albicans, enterococcus faecalis and staphylococcus aureus. braz oral res 2010; 24(4): 406. pardeep f.doc j bagh college dentistry vol. 28(2), june 2016 management of restorative dentistry 26 management of independent middle mesial canal in mandibular first molar using cone beam computed tomography imaging as an adjunct – a case report pardeep mahajan, b.d.s., m.d.s. (1) prashant monga, b.d.s., m.d.s. (2) roma goyal, b.d.s. (3) nitika bajaj, b.d.s., m.d.s. (4) abstract the primary objective of root canal therapy is adequate biomechanical preparation of root canal system followed by 3d obturation.in clinics we are encountered with several anatomical variations, which we need to manage efficiently. one of the major factors responsible for failure of root canal therapy is missed canals. recent technological advances have given the clinician opportunity to identify anatomical variations and treat them to satisfaction. key words: root canal aberrations, middle mesial canal, missed canals, anatomy of mandibular molar. (j bagh coll dentistry 2016; 28(2):26-29). introduction root canal anatomy plays a significant role in endodontic success and failure (1,2), therefore; for initiation of endodontic procedure, we should be familiar with internal tooth anatomy (3). if a canal is missed during endodontic treatment, then necrotic debris, pathogens and related irritants present in it can contribute to the formation of endodontic lesion, thus failure (2,4). so, for the success of root canal therapy, a thorough knowledge of normal root canal anatomy and its possible variations of that particular tooth are vital. when we consider different type of teeth, mandibular molar has complex anatomy (5).the presence of middle mesial (mm) canal in a mandibular molar was first reported by vertucci and williams (6,7). out of the types of middle mesial canals, the independent middle mesial canal is one which originates as a separate orifice and terminates at a separate foramen (8). out of hundred cases studied by pomeranz et al. (8), only two cases were having independent canals. according to goel et al. (9) out of total sixty mandibular first molars studied by them, only 6.7% of the middle mesial canals were independent. traditionally we use radiographic examination using conventional iopa films for the evaluation of the root canal configuration. but due to its limitations; it is sometimes not able to identify the root canal system to satisfaction. (1)head of the department, conservative dentistry and endodontics. (2)reader, conservative dentistry and endodontics. (3)postgraduate student, conservative dentistry and endodontics. (4)reader, pedodontics and preventive dentistry so to overcome these limitations, cone beam computed tomography (cbct) imaging is a useful adjunct to study the root canal anatomy more precisely. it is better alternative to multidetector ct imaging in endodontics (10). cbct has a number of applications in endodontics as stated by cotton et al (11). furthermore, matherne et al. (12) suggested that cbct imaging also helps in identifying the root canal system. this case report presents management of mandibular first molar with an independent middle mesial canal by using cbct imaging as an adjunct to identify the anatomy of middle mesial canal from orifice to apical foramen. case report a 55 year-old female reported to department of conservative dentistry and endodontics, genesis institute of dental sciences and research, ferozepur, india with pain in the posterior right mandibular region for the last two weeks. she gave a history of intermittent, moderate intensity and non radiating type of pain. she gave dental history of sensitivity to hot and cold in that region for the past few months. her past medical history was non significant. on clinical examination, a carious lesion was found on right mandibular first molar. tooth was tender on percussion. so, a diagnosis of chronic irreversible pulpitis with apical periodontitis was reached, thus requiring root canal treatment (figure1). on thorough radiographic examination, there was slight indication of abnormal canal j bagh college dentistry vol. 28(2), june 2016 management of restorative dentistry 27 configuration as compared to usual two canals in the mesial root. figure 1: preoperative radiograph of right mandibular first molar to study the exact anatomy configuration of expected extra canal in mesial root, decision was taken to get cbct imaging done. consent was taken from the patient. cbct of the mandible with the focus on the right mandibular first molar was performed. axial, coronal, and sagittal cbct slices revealed four canals (one in the distal root and three in the mesial root) in the referred tooth (figure 2a,2b). figure 2: a. coronal cbct slice of right mandibular first molar at various levels figure 2: b. sagittal cbct slice of right mandibular first molar tooth was anesthetized using 2% lignocaine with 1:80,000 adrenaline. under rubber dam isolation access cavity was prepared. the pulp floor showed three orifices corresponding to normally present three root canals: mesiobuccal, mesiolingual (ml), distal (d). but on careful inspection of the pulp chamber floor with magnification using operating microscope and dg16 probe revealed third canal opening in the mesial root (figure 3). apex locator (root zx, morita, tokyo, japan) was used to measure working length, then a confirmatory iopa radiograph was taken (figure 4). figure 3: view of pulp chamber under operating microscope j bagh college dentistry vol. 28(2), june 2016 management of restorative dentistry 28 figure 4: working length radiograph. after confirmation of four canals, pulpectomy was performed. root canal preparation was performed with protaper rotary instruments (dentsply maillefer, ballaigues, switzerland) using step-down technique. 3% sodium hypochlorite (prevest denpro limited. jammu, india) was used for irrigation during instrumentation, followed by 17% edta (prevest denpro limited, jammu, india). normal fresh saline (beryl drugs ltd, india) was used as final irrigant, then canals were dried with fresh sterile paper points (diadent group international, korea). obturation was performed using gutta-percha (dentsply, petropolis, rj, brazil) and ah plus sealer (dentsply detrey gmbh, konstanz, germany) using cold lateral condensation technique (figure 5). in the follow up visit after six months of the endodontic treatment, the patient was asymptomatic. figure 5: post-obturation radiograph. discussion for the success of root canal treatment, a thorough knowledge of root canal morphology is vital (13). when we are not able to locate the canal, it lefts untreated (14,15). presence of three canals in mesial root of mandibular first molar has been reported by many authors (16). fabra et al. (17) found in a study that out of total 760 samples, 20 mandibular molars were having three canals in the mesial root but only one tooth had independent middle mesial canal. as reported in various case reports and in vitro studies, incidence of middle mesial root canal in mandibular molars is 1-15% (18). careful clinical and radiographic inspection is backbone of endodontic success. important diagnostic aids in locating root canal orifices are taking multiple angled radiographs, using sharp explorer to examine the pulp chamber floor , use of magnification, observing canal bleeding points, using ultrasonic tips for troughing, staining the chamber floor with 1% methylene blue dye and using sodium hypochlorite “champagne bubble test” (19). careful observation of angled radiographs is an important adjunct in identifying the variations in anatomy of mesial root of mandibular first molar. instead of single straight view, buccolingual views i.e. 20° from mesial and 20° from distal reveal much better information of the root canal system. but a 2d image of 3d object is a significant limitation of conventional radiography. but interpretation based of 2d radiograph may alert the clinician about any aberrant root canal anatomy of tooth but would not be able to present the exact anatomy and its interrelations (20). so, advanced diagnostic aids should be used to study morphology more precisely (19). tuned aperture computerized tomography imaging enhances canal detection as compared to conventional radiography as stated by nance et al. (21). gopikrishna et al. also used spiral computerized tomography to study morphological aberration in the maxillary first molar (20). cbct machine used in this report is specifically made to display small parts of the jawbone with an image field size similar to that of ordinary dental films. advantage of this machine is that it has considerably low effective dose than conventional cbct machines. when only a small volume is examined dose is equivalent to two to three periapical radiographs (21). thus by using this imaging, we are able to study the root canal configuration and treat it adequately which is vital for long term success of root canal therapy. as conclusion; treating tooth with abnormal root canal morphology is a tough task. inadequate preparation of root canal system can lead to failure. with the advent of cbct, we can better understand root canal anatomy, which in turn enables the clinician to do root canal procedures in a better way with predictable results j bagh college dentistry vol. 28(2), june 2016 management of restorative dentistry 29 references 1. hargreaves km, cohen s. pathways of the pulp. 10th ed. st. louis: mosby; 2011. 2. barkhordar r, stewart g. the potential of periodontal pocket formation associated with untreated accessory root canal. oral surg oral med oral pathol 1990; 7: 6– 10. 3. petridis xm, dechouniotis gp, kondylidou v, georgopoulou mk. middle mesial canal in mandibular molars: review and clinical case reports. endo (londengl) 2012; 6(2):143–52 4. hess j, culieras m, lamiable n. a scanning electron microscope investigation of principal and accessory foramina on the root surfaces of human teeth: thoughts about endodontic pathology and therapeutics. j endod 1983; 9: 7–11. 5. skidmore ae, bjorndal am. root canal morphology of the human mandibular first molar. oral surg oral surg oral pathol 1971; 32: 778–84. 6. vertucci fj, williams rg. root canal anatomy of the mandibular first molar. jnj dent assoc 1974; 48: 27–8. 7. weine fs. case report: three canals in the mesial root of a mandibular first molar. j endod 1982; 8: 517–20. 8. pomeranz hh, eidelman dl, goldberg mg. treatment considerations of the middle mesial canal of mandibular first and second molars. j endod 1981; 7:565–8. 9. goel nk, gill ks, taneja jr. study of root canals configuration in mandibular first permanent molar. jisppd 1991; 8:12–4 10. tachibana h, matsumoto k. applicability of x-ray computerized tomography in endodontics. endod dent traumatol 1990; 6:16–20. 11. cotton tp, geisler tm, holden dt, et al. endodontic application of cone-bean volumetric tomography. j endod 2007; 33:1121-32. 12. matherne rp, angelopoulos c, kulild jc, et al. use of cone-bean computed tomography to identity of root canal systems in vitro. j endod 2008; 34:87-9. 13. adanir n. an unusual maxillary first molar with four roots and six canals: a case report. aust dent j 2007; 52: 333-5. 14. ingle jl, backland lk, brveridge ee, glick dh, hoskinson ae. modern endodontic therapy. 5th ed. philadelphia: lea and febiger; 2002. pp. 123. 15. cohen s, burns rc. nonsurgical endodontic retreatment. pathways of the pulp. 8th ed. st. louis: mosby; 2002. pp. 875929. 16. baugh d, wallace j. middle mesial canal of the mandibular first molar: a case report and literature review. j endod 2004; 30: 185-6. 17. fabra-campos h. three canals in the mesial root of mandibular first permanent molars: a clinical study. int endod j 1989; 22: 39-43. 18. subbiya a, kumar ks, vivekanandhan p, prakashv. management of mandibular first molar with four canals in mesial root. j conser dentistry 2013; 16: 471-3. 19. vertucci fj. root canal morphology and its relationship to endodontic procedures. endod topics 2005; 10: 3-29. 20. gopikrishna v, ruben j, kandaswamy d. endodontic management of a maxillary first molar with two palatal roots and a single fused buccal root diagnosed with spiral computerized tomography: a case report. oral surg oral med oral pathol oral radiol endod 2008; 105:74-8. 21. nance r, tyndall d, levin lg, trope m. identification of root canals in molars by tuned-aperture computer tomography. int endod j 2000; 33: 392-6. 22. lofthag-hansen s, hummonen s, grondahi k, et al. limited cone-beam ct and intraoral radiography for the diagnosis of periapical pathology. oral surg oral med oral pathol oral radiol endod 2007; 103:114-9. journal of baghdad college of dentistry, vol. 35, no. 1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 1 research article in vitro assessment of bracket adhesion post enamel conditioning with a novel etchant paste hayder a. kadhim1, 2, *, sanjukta deb3, ali i. ibrahim 1, 3 1 department of orthodontics, college of dentistry, university of baghdad, baghdad, iraq. 2 department of p.o.p., college of dentistry, university of kufa, najaf, iraq. 3 centre for oral, clinical and translational sciences, faculty of dentistry, oral & craniofacial sciences, king’s college london, london, uk. * corresponding author: ali.ibrahim@kcl.ac.uk abstract: background: 37% phosphoric acid (pa) is the traditional enamel etching technique prior to bracket adhesion, yet it has been implicated in numerous enamel injuries. the purpose of the current study was to create a calcium phosphate (cap) etching paste in a simplified capsule formula that can underpin clinically adequate bracket bond strength without jeopardizing the integrity of enamel upon the debracketing procedure. materials and methods: micro-sized hydroxyapatite (ha) powder was mixed with 40% pa solution to prepare experimental acidic cap paste. sixty human premolars were assigned into two groups of 30 each. enamel conditioning was accomplished using 37% pa-gel for control group and cap paste for experimental group. each group was further divided into two subgroups regarding the water storage (ws) period (24 h and 30 days). shear bond strength (sbs) test conducted with examination of debonded surfaces for adhesive remnants and enamel damage using a digital microscope. results: cap paste produced significantly lower sbs values than pa (p < 0.01), yet sufficient for clinical use. pa etching caused often cracked enamel surfaces with excessive retention of adhesive remnants (mainly ari scores 2 and 3). contrarily, enamel treated with the experimental cap paste exhibited smooth, unblemished surfaces mostly clean of adhesives residues (scores 0 and 1). conclusion: a newly developed cap paste in a capsule formula fosters clinically adequate bracket adhesion with a sustained bonding performance, allows a harmless bracket removal with minimal or no adhesive residues on debonded surfaces; thus, it can be introduced as a suitable alternative to pa. keywords: enamel conditioning, calcium phosphate, bracket bond strength. introduction direct bracket adhesion to tooth enamel represents a milestone in contemporary orthodontics. bracket adhesion using resin-composite adhesives is typically preceded by alteration of the enamel surface via 37% pa etching. such treatment was found to provide a robust bracket adhesion as it induces the most retentive surface topography for resin adhesive (1). nevertheless, this technique enclosed several potential harms to tooth substrate. of these, the deep and pronounced demineralization effect which substantially minimizes micromechanical properties of the enamel, besides the potential cracks and tear-outs occurring in the course of the debonding procedure because of the excessive force applied in brackets removal at the end of orthodontic therapy (2–4). moreover, the detriment can be aggravated with remaining a lot of adhesives on the debonded surfaces that necessitate removal using traumatic rotary burs that inevitably induce additional enamel scratching (5). several other acids with different concentrations, e.g. citric, pyruvic, and maleic acids, were investigated for enamel conditioning. it was found that such acids were less effective compared with received: date: 01-12-2022 accepted: date: 10-01-2023 published: date: 15-03-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v35i1.3309 mailto:ali.ibrahim@uokufa.edu.iq https://orcid.org/0000-0002-8476-3034 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3309 https://doi.org/10.26477/jbcd.v35i1.3309 j. bagh. coll. dent. vol. 35, no. 1. 2023 kadhim et al 2 pa in terms of providing clinically useful bracket bonding strength (6). in the last decades, self-etch primers (seps) were suggested as an alternative enamel conditioning technique (7). seps were advocated to facilitate the fixation of orthodontic brackets to teeth surfaces by reducing bonding steps as they merge etching and priming steps excluding the water-rinsing phase. it was observed that seps induce a conservative etching effect with decreased resin infiltration, which more likely minimizes the extent of enamel loss (8). however, contradicting data were documented regarding the sbs to enamel, adhesive remnants and the occurrence of enamel damage at bracket debonding (9). besides these, a novel etchant system was recently evolved, based on mixing two cap compounds with a pa solution to formulate an acidic cap paste capable of inducing gentle enamel etching accompanied by cap precipitation, prior to orthodontic bracket bonding. it was observed that this paste provided bracket bond strength suitable for clinical use, and also induced minimal residual adhesives remained with a low incidence of enamel harms upon bracket debond. nevertheless, a time-consuming manual mixing, of two types of caps, basic (β-tcp) and acidic (mcpm) powders, was required for paste preparation (10). research is ongoing to find out a time-conserving and tooth-friendly enamel conditioning system that can induce orthodontic bracket bonding and debonding with minimal undesirable iatrogenic impacts. from a clinical perspective, the bonding system being effective when providing a tooth-adhesive interface able to survive storage in a degrading medium (11). therefore, the aim of this study was to develop a cap-based etchant in a simplified recipe as a mixing capsule formula to be more clinically convenient for enamel conditioning during orthodontic bonding procedure, and investigate its bonding efficiency in terms of shear bond strength, amount of residual adhesive, and enamel surface damage after shortand long-term ws in comparison with the standard etchant material (37% pa). material and methods experimental cap etchant paste was prepared as follows: micro-powder of hydroxyapatite (ha) (sigma-aldrich chemie gmbh co., steinheim, germany) was used to be mixed with pa solutions of 40% by weight that prepared by diluting pa (85 wt%, carlo erba reagent, france) with distilled water (dw). using a 0.4:1 powder to liquid ratio (p: l), the assigned amounts of powder and liquid were gathered into a 2ml eppendorf tube, that was used as a “mixing capsule” and placed in a dental amalgamator (lingchen dental co., ltd, china). a homogenous workable paste was obtained after 15 s mixing, ready to be applied on the buccal enamel surface. the ph of the resultant paste in addition to 37% pa was assessed using a digital ph meter supplied with a flat-surface ph electrode (model s450cd, sensorex, usa) after mixing under ambient lab conditions (22-25° c, 30-40% humidity). the sample of current study involved sixty human premolars extracted for orthodontic reasons from individuals with an age range of 15-30 years after acquiring ethical approval from the research ethical committee of the college of dentistry at the university of baghdad (ref. no.: 355421/355). after extraction, the soft tissues and blood residuals were cleaned from teeth surfaces using running tap water. teeth were stored in 1% chloramine-t trihydrate as a bacteriostatic/bactericidal solution for one week, then transmitted into dw for storage. the teeth selected for this study had a sound enamel surface with no cracks or hypoplasia and did not undergo any chemical treatment. to facilitate handling and control of the specimens during sbs test, each premolar tooth was fixed vertically inside a custom-made silicone mould (18×18x15 mm). the analyzing rod of dental surveyor (addler, j. bagh. coll. dent. vol. 35, no. 1. 2023 kadhim et al 3 golden nimbus ltd, maharashtra, india) was utilized to align the buccal surface, thereby the bracket base, to be parallel to the debonding force applied during the shear test. self-cure acrylic resin (major repair, major prodotti dentari s.p.a., italy) was mixed to be poured around the root up to 1mm apical to the cementoenamel junction. after complete acrylic curing, the mounted teeth were kept moist at the lab temperature until the bonding time. they were divided into two main groups (n=30) regarding the etchant applied for enamel etching, i.e. commercial 37% pa and developed cap paste. the etch-and-rinse (ear) protocol was followed for conditioning enamel surfaces in all study groups. this protocol was implemented as follows: 30 s etchant application, 10 s water rinsing and 10 s oil-free air drying. the surface of each specimen was primarily polished with non-fluoridated pumice at a low speed (10 s), then rinsing with water (10 s) and air-drying (10 s). the etchant material, 37% pa-gel (proclinic, madrid, spain) in the control group and cap paste in the experimental group, was applied on the middle third of the buccal surface of each specimen. afterwards, stainless steel premolar brackets (pinnacle, mbt prescription with 0.022” slot, orthotechnology, usa) were used for bonding in both groups using transbond xt primer and transbond xt adhesive (3m unitek, monrovia, california, usa). a thin layer of transbond xt primer was applied onto the etched enamel surface and spread by air-jet for 3 s. after loading the base with a thin layer of transbond xt adhesive, the bracket immediately positioned on the specimen surface and firmly pressed (300 g force for 10 s) using a pressure gauge (dontrix force gauge, dtc medical apparatus co., hangzhou, china). light-curing of adhesive was conducted for 10 s on each mesial and distal side of the bracket using light emitting diode (led) curing light (sdi radii plus, 1,500mw/cm2 light intensity, victoria, australia) according to manufacturer instructions. after bonding, the specimens were incubated inside dw at 37°c for 24 h, after that half of each group (n=15) was tested for shear bond strength (sbs), while the other half continued storage in dw for 30 days with daily dw refreshment. after the mentioned storage periods, specimens were subjected to sbs test using universal testing machine (wdw-100e, time group inc., beijing, china) with a 4 kn load cell, at the college of material engineering/university of kufa; the bracket debonded with a crosshead speed of 0.5 mm/min. the surface area of the bracket base (11.46 mm) was input into the computer prior to testing, so that the readings were demonstrated in megapascal (mpa). the debonded bracket besides the specimen were set aside in a labelled container showing the subgroup name for post-debonding surface examination. the debonded enamel surfaces were inspected using a digital microscope (dino-lite pro, anmo electronics co., taiwan) at x20 magnification to determine signs of crack or tear-out if any, and to evaluate the amount of the adhesive material remaining on the tooth surface to be scored according to the ari system (12). statistical analysis sbs data distribution at both testing times, preliminarily checked by shapiro-wilk test, assumed the normality (p ˃ .05). student t-test for independent samples applied to assess the statistical difference between subgroups of 37% pa and experimental cap pastes at both debonding time points. ari scores were examined for difference between control and cap paste subgroups using mann-whitney test. the level of significance was set p< 0.05 at all statistical tests. j. bagh. coll. dent. vol. 35, no. 1. 2023 kadhim et al 4 results the ph and sbs values of both the control and experimental subgroups at 24 h ws and 30 d ws are shown in table 1 and figure 1. at both testing time points, teeth etched with pa recorded consistently higher sbs values than those etched with the experimental cap paste. the 30 d ws showed a non-significant influence on sbs of brackets bonded to teeth treated either with 37% pa or acidic cap paste. statistically significant differences were also found in the ari scores between the control and cap paste subgroups (table 2). it was obvious that specimens etched with 37% pa tended to retain more amounts of adhesive upon brackets debonding at both testing times. in contrast, debonded teeth in cap paste subgroups revealed enamel surfaces with minimal or no adhesive residues. in addition, by examining the debonded enamel surfaces using a digital microscope, several specimens of the control subgroups were found to have either cracks or fractures, whereas the specimens of the cap subgroups showed smooth surfaces with no evidence of enamel injury at both testing time points (figure 2). table 1: ph and sbs (mpa) values of the control and experimental etchants after 24 h and 30 d ws. etchant ph 24 h ws mean (sd) 30 d ws mean (sd) cap paste 1.2 21.9 (7.99) a 18.2 (5.58) a 37% pa 0.6 31.99 (3.83) b 31.86 (8.93) b different letters indicate statistically significant differences between control and cap paste subgroups (t-test). table 2: ari scores after 24 h and 30 d ws for control and experimental subgroups. etchant 24 h ws ari 30 d ws ari 0 1 2 3 0 1 2 3 cap paste 9 6 0 0 a 11 4 0 0 a 37% pa 1 7 (4 ec) 4 (2 ef) 3 b 2 7 (3 ec) 2 (1 ef) 4 b ec: enamel crack, ef: enamel fracture. adhesive remnant index (ari) scores: (0): no adhesive left on the tooth, (1): less than half of the adhesive left on the tooth, (2): more than half of the adhesive left on the tooth, (3): all adhesive left on the tooth with a distinct impression of the bracket mesh. different letters indicate statistically significant differences between control and cap paste subgroups (mann-whitney test). j. bagh. coll. dent. vol. 35, no. 1. 2023 kadhim et al 5 figure 2: digital microscope photographs of debonded specimens. a-d: etched with cap paste; the enamel surfaces appear smooth and unharmed with minimal or no adhesive remnants. e-h: etched with 37% pa; enamel surfaces have noticeable damage. bracket debonding was accomplished after 24 h (a, b, e, f) and after 30 d (c, d, g, h). discussion orthodontic bracket fixation to teeth preceded by 35-40% pa treatment of enamel surface has been undoubtedly an effective approach in clinical practice, yet it has been implicated with a wide range of undesirable iatrogenic impacts on enamel surface. despite several promising attempts in this regard, enamel conditioning techniques still require to be optimized to establish a secure bracket figure 1: bar chart illustrating sbs values for all subgroups according to testing time. 0 5 10 15 20 25 30 35 40 45 24 h 30 d ws s b s ( m p a ) testing time 37% pa cap paste j. bagh. coll. dent. vol. 35, no. 1. 2023 kadhim et al 6 adhesion associated with fewer or no adverse effects. therefore, the current study intended to develop a bioactive etchant material in a simplified capsule formula that can underpin clinically adequate bracket bond strength without jeopardizing the integrity of enamel upon etching and debonding procedures. considerably variable sbs values have been described in the literature for nominally the same enamel etching protocol and adhesive system; this can be attributed to the multiplicity in test configurations among in vitro experiments (13). many parameters, such as etching protocol, adhesive material, debonding time and bracket base shape, have been defined as variables affecting the in vitro evaluation of orthodontic brackets bond strength (14). thus, the ear technique using 37% pa reported a wide spectrum of bond strength values ranged from 9 to 35 mpa (15). the mean sbs values of all subgroups in the present study came in accordance with the above-reported range. enamel etching with 37% pa-gel yielded significantly higher sbs values, at both testing times, than etching with the experimental cap paste. this finding comes in accordance with the fact that the 37% pa etchant produces the highest bond strengths compared to any other etchant used for enamel conditioning (16,17). indeed, the mechanism of bonding to enamel is essentially based on the micro-mechanical interlocking of resin monomers into created micro-pores through the differential removal of minerals from the dental substrate as a result of surface pre-treatment with an acidic etchant material (18). thus, the resin infiltration morphology plays a major role in determining the resultant resin-enamel bond strength. the pattern of inter-crystallite resin infiltration inside the prisms and the deep penetration into the inter-prismatic spaces was associated with high bond strength, whilst a shallow etch depth with intercrystallite resin infiltrations and lack of inter-prismatic resin tags were accounting for reduced bond strength. the former was frequently correlated to high pa concentrations, whereas the latter was observed when reduced concentrations were used (19). this is also supported by previous research stating that the resultant morphology and depth of resin infiltration depend on the etching potential and the ph value of the etchant materials (4). enamel treatment with 37% pa-gel of an acidic ph value (0.6) leads to extensive micro-pores creation post a very short application time (15-30 s) because the ph remained probably unchanged even with the dissolution of ha from the enamel surface leading to a strong etching effect and a recognized inter-prismatic demineralization, thereby thick resin tags are established yielding high bond strengths (20). this finding is supported by a previous study that recorded higher bond strength values with a more acidic meta-pa (ph 0.5), similar to conventional 37% pa (21). it was also concluded that the sbs is closely related to the ph of the etchant (22). on the other hand, enamel etching with cap pastes of higher ph (1.2) yielded significantly lower sbs values compared with the control (37% pa). pre-mixing of ha micro-powder with 40% pa imposed an effective buffering effect leading to a rise in the ph of resultant cap paste. when this paste with less acidity was applied onto the tooth surface, the demineralization process occurred to a limited extent producing a milder etching effect; thereby resin penetration was diminished leading to a drop in resultant sbs. however, the sbs values obtained with the cap pastes subgroups exceeded the suggested threshold (6–10 mpa) in the vast majority of the literature as admissible for clinical performance (23,24). the change in bond strength following 24 h has received limited attentiveness, where most in vitro experiments were confined to the evaluation of sbs at 24 h presuming that this reflects long-term bonding efficiency. the resultant enamel-adhesive interface actually undergoes several challenges in j. bagh. coll. dent. vol. 35, no. 1. 2023 kadhim et al 7 the oral environment, which can impose adverse effects on the bonding longevity of an orthodontic adhesive system (25). it was reported that one of the major factors encountered in vivo environment is the bond strength deterioration due to water ageing that is thought to be a result of interface components hydrolysis and water infiltration, which can also weaken the mechanical properties of the adhesive polymer matrix (26,27). therefore, aging in water was the most frequently used artificial aging protocol to examine the durability of created enamel-adhesive joint (28). the testing of bracket adhesion in specimens treated with either the cap paste or pa revealed a non-significant reduction in sbs outcomes after 30 d ws. this can be attributed to that the created enamel-adhesive joint using the etchant paste or 37% pa was sufficiently appropriate to endure the long-term water ageing process. this agrees with the findings of previous studies, which found that the durable bonding interface established by the ear technique could tolerate prolonged ws periods, extended for 30 d to 2 years, without significant alteration in bond strengths (11,28,29). in the current study, the examination of the debonded enamel surfaces demonstrated that the etchant type had an impact on the failure mode, with the site of bond failure differing between the control and experimental etchant material. in control subgroups, the failure was mainly an adhesive failure at the bracket/adhesive interface, with the majority of residue adhesive remained on the tooth surface (ari scores 2 and 3), indicating a stronger bond between the adhesive and enamel. it was observed that when the enamel was etched using 37% pa, where a deep and pronounced interaction occurs with the enamel surface creating the most retentive morphology for adhesive material, hence upon bracket debonding, much of adhesive remains on the tooth surface (20). moreover, brackets bonded to pa-etched enamel surfaces entail a high debonding force which associated with high incidence of enamel hurts, e.g. cracks and/or tear-out (30,31). it was reported that the risk for enamel damage increased with a higher bracket bond strength (4). the outcomes of the present study advocate this view, as shown in figure 2 e-h, where bracket removal in 37% pa subgroups was associated with varying forms of enamel damage so that several teeth exhibited enamel cracks and tear-outs. in contrast, the experimental pastes revealed a frequent failure at the enamel/adhesive interface recording significantly lower ari scores (mostly 0 and 1). changing the composition and the ph of experimental etchant pastes achieved in the current study probably had a considerable role in the conservative interaction with enamel, hence facilitating adhesive failure at the enamel/adhesive interface, more clinically convenient, which makes the debonding and subsequent polishing much easier (10). moreover, the teeth treated with developed etchant paste notably revealed smooth, unblemished enamel surfaces after bracket debonding; this might have resulted from the milder etching effect and diminished resin penetration into the etched enamel substrate that has frequently been associated with a reduced risk of enamel damage upon bracket removal (8). with the absence of the effect of other intraoral factors such as chewing forces besides temperature and ph fluctuations commonly encountered in the normal oral environment, the findings of this study should be extrapolated with caution; the evaluation of bonding performance of the developed cap paste via a clinical trial is thus required. conclusion this in vitro study presented a newly developed cap paste in a mixing capsule formula, which fosters clinically adequate bracket adhesion with a sustained bonding performance, and allows a harmless bracket removal with minimal or no adhesive residues on debonded surfaces; thus, it can be introduced as a suitable alternative to conventional 37% pa. j. bagh. coll. dent. vol. 35, no. 1. 2023 kadhim et al 8 conflict of interest: none references 1. vinagre, a.r., messias, a.l., gomes, m.a., et al. effect of time on shear bond strength of four orthodontic adhesive systems. rev port estomatol med. dent. cir. maxilofac. 2014; 55(3): 142-51. 2. hosein, i., sherriff, m., ireland, a.j. enamel loss during bonding, debonding, and cleanup with use of a self-etching primer. am j orthod dentofacial orthop. 2004; 126(6): 717-24. 3. pont, h.b., özcan, m., bagis, b., et al. loss of surface 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cracks and ceramic bracket failure during debonding in vitro. angle orthod. 2008; 78(6): 1078-83. جديد تقييم مختبري للتصاق الحاصرات بعد تكييف المينا باستخدام عجينة حفرالعنوان: اسماعيل ابراهيم , علي سانجوكتا ديب , الباحثون: حيدر عبد المنعم كاظم المستخلص في العديد من إصابات المينا. الهدف من هذه الدراسة هو تورط٪ التقليدي هو المعيار الذهبي لحفر المينا قبل الصاق الحاصرات ، ومع ذلك فقد 37 (pa)الخلفية: حمض الفوسفوريك بصيغة كبسولة مبسطة يمكن أن تدعم قوة رابطة الحاصرات المناسبة سريريًا دون المساس بسالمة المينا عند عملية إزالة األقواس. المواد (cap)تطوير معجون فوسفات الكالسيوم بشريًا سليًما بشكل الحمضي التجريبي. تم تقسيم ستين ضاحكًا capلتحضير معجون pa٪ محلول 40( مايكروية الحجم مع haوطرق العمل: تم خلط مسحوق هيدروكسيباتيت ) )ن= رئيسيتين مجموعتين إلى باستخدام 30عشوائي المينا تكييف إجراء تم جل37(. ٪ pa ومعجون الضابطة إلى capللمجموعة مجموعة كل تقسيم تم التجريبية. للمجموعة ( مع فحص األسطح بعد نزع الحاصرات بحثًا عن بقايا sbsر قوة رابطة القص )يوًما(. تم إجراء اختبا 30ساعة و 24) (ws)مجموعتين فرعيتين فيما يتعلق بفترة تخزين المياه في pa، لكنه كاف لالستخدام السريري. تسبب حفر pa (p <0.01)٪ 37أقل بكثير من sbsالمطور قيم capالالصق وتلف المينا باستخدام مجهر رقمي. النتائج: أنتج معجون التجريبي cap(. في المقابل ، أظهر المينا المعالجة بمعجون ariمن 3و2 ا مع االحتفاظ المفرط ببقايا المادة الالصقة )بشكل أساسي درجاتكثير من األحيان في تشقق أسطح المين بة كبسولة خلط يعزز التصاق حاصرات المطور حديثًا في تركي cap(. االستنتاج: معجون 1و 0أسطًحا ناعمة ال تشوبها شائبة نظيفة في الغالب من بقايا المواد الالصقة )الدرجات لمنزوعة الحاصرات؛ وبالتالي ، يمكن تقديمه مناسب سريريًا مع أداء ارتباط مستدام ، ويسمح بإزالة القوس غير المؤذي مع الحد األدنى من بقايا الالصق أو عدم وجودها على األسطح ا .التقليدي pa٪ 37كبديل مناسب لـ enas.doc j bagh college dentistry vol. 27(2), june 2015 efficacy of arthrocentesis oral and maxillofacial surgery and periodontics 105 efficacy of arthrocentesis with injection of hyaluronic acid in the treatment of internal derangement of temporomandibular joint adil al kayat, b.d.s., m.sc., f.d.s.r.c.s. (1) thair abdul lateef, b.d.s., h.d.d., f.i.b.m.s. (2) enas abdulsttar abdulmajed, b.d.s. (3) abstract background: temporomandibular joint disorders refer to a group of heterogeneous pain and dysfunction conditions involving the masticatory system, reducing life quality of the sufferers. arthrocentesis is simple and less invasive surgical procedure for the treatment of internal derangement than arthroscopy and better than other conservative procedures such as drugs, occlusal appliances and physiotherapy. the aim of the study was to evaluate the effect of arthrocentesis with injection of hyaluronic acid in the treatment of internal derangement of temporomandibular joint for the restoration of its function, reducing pain and preventing further deterioration of the temporomandibular joint dysfunction. materials and methods: this study was performed in al-sheed ghazi al-hariri hospital, department of oral and maxillofacial surgery, from november 2012 to october 2013, included 60 patients, aged 18 to 45 years with symptoms of temporomandibular joint pain, clicking during function and limited mouth opening. temporomandibular joint internal derangement was assessed with clinical examination and confirmed with computed tomography scan. arthrocentesis was done with insertion of two 18 gauge needles in the upper joint compartment, lavaged with ringer’s lactate solution and at the end of the procedure 1ml of hyaluronic acid was injected. intensity of temporomandibular joint pain was assessed using visual analog scale, maximum mouth opening was assessed with ruler scale and joint clicking was assessed clinically by stethoscope and manual palpation. all the parameters were measured before the procedure then 1 and 3 months later. results: during 4 months follow-up, clinical examination and comparison of the results showed reduction in pain with success rate 95%, improvement in mouth opening with success rate 100% and clicking disappeared in 95% of patients. conclusion: the technique of arthrocentesis using sodium hyaluronate injection, used in patients who presented with internal derangement, showed therapeutic benefits, simplicity, safety, patients acceptance of the technique and lack of significant side effects and complications. key words: tmj pain, clicking, internal derangement, arthrocentesis, hyaluronic acid. (j bagh coll dentistry 2015; 27(2):105-109). introduction temporomandibular joint dysfunction (tmjd) is a therapeutic challenge for oral and maxillofacial surgeons. the term tmjd is used to describe a group of conditions that include painful myofascial problems involving the muscles of mastication. internal derangements (id) of the joint space contents is one of most frequent cause of temporomandibular joints dysfunction.(1) temporomandibular joint internal derangement (tmjid) or articular disk displacement is abnormal relationship between the disk, the mandibular condyle and the articular eminence resulting from stretching or tearing of attachment of the disk to the condyle and glenoid fossa, tmjid is later characterized by pain during mandibular movement, abnormal joint sounds (clicking) and limitation in range of mandibular motion.(2) (1) assistant professor, chairman of the scientific council of oral and maxillofacial surgery. the iraqi board for medical specializations. (2) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (3) student at the scientific council of oral and maxillofacial surgery, the iraqi board for medical specializations. the specific etiology in majority of cases of disc displacement is laxity of joint.the primary goal of therapeutic management of tmj is pain relief, maintain normal range of motion and prevention of joint damage.many conservative approaches include para-functional habits control, physiotherapy, soft diet and non-steroid antiinflammatory drugs (nsaids) before any invasive procedure is considered.(3)arthrocentesis is a minimal invasive technique, simple, less expensive, with low morbidity used for flushing out tmj that is performed by double access to theupper joint space.(4) the effectiveness of joint lavage in those cases may be explained by the joint space expansion with ringer lactate and washing out the intra articular inflammatory mediators and catabolytes to release the articular disc and to remove adhesions between disc surface and mandibular fossa and combined technique providing the injection hyaluronic acid (10 mg/ml) 1ml sterilized syringe at the end procedure to improve joint lubrication of synovial membrane and replacement of synovial fluid in tmj joint.(5) j bagh college dentistry vol. 27(2), june 2015 efficacy of arthrocentesis oral and maxillofacial surgery and periodontics 106 hyaluronic acid (ha) is a very important component of the articular cartilage and has a significant role in maintaining the articular lubrication and nutrition for the articular tissues. sodium hyaluronate (sh) is indicated in case of replacement and/or complementing of synovial fluid damaged following degenerative or traumatic origin diseases of the articulation. the administration of sh results in a marked pain reduction and improvement of mobility.in pathological conditions, like rheumatoid arthritis and osteoarthritis, the concentration and molecular weightof sh in the synovial fluid are diminished which synthesized by synoviocytes with consequent impact on the sh articulation. so the pathological fluid is removed and the exogenoussh material is infiltrated thus bring the synovial fluid back to normal and is able to restore the physiological conditions of the joint that has failed to respond to conservative medical and physical therapies.(6) materials and methods this prospective study include 60 patients (40 females and 20 males), their ages ranged from 1845 years with mean of age 31.5 years. these patients were seen and treated in the consultation clinic of oral and maxillofascial surgery in ghazi al-hariri hospital in medical city (from november 2012 to october 2013) in which all patients were accepted to be involved in the study. inclusion criteria: 1. clinical signs of id, (pain, crepitus and limitation mouth opening with close lock of tmj more than six months). 2. previous conservative treatment failed to resolve symptoms (homecare, dietary restriction and pharmaco therapy). 3. age of patients range from 18-45 years. 4. patients signed a special consent on the procedure. exclusion criteria: patients suffering from degenerative joint disease (osteoarthritis, rheumatoid arthritis and gout) were excluded from the study. the following materials and instruments used: 1. ringer lactate solution (na 130 /cl 109 /k 4 /hco3 28 /ca 3 meq/l) 2. sodium hyaluronate 10 mg/ml (hyalgan; fida, albano, italy). 3. local anesthesia (1 cartridge) septodent1:80000 lignocaine with adrenaline 4. disposable syringe 60 cc. 5. two needles with 18 gauges. 6. soft plastic ruler. 7. plastic mouth gag. 8. antiseptic (betadine). the patient was placed in supine position with head in opposite direction. the pre-auricular area of the affected site was prepared aseptically with betadine solution. a line was drawn from mid tragus of the ear to lateral canthus of the eye. the first point was marked 7 mm anterior from tragus and 1 mm downward in the tragalcanthal line. the second point was marked 10 mm posterior and 2 mm downward in the same line. auriculotemporal nerve was blocked through the skin just anterior to the junction of the tragus and ear-lobe.the needle was advanced behind the posterior aspect of the condyle in anteromedial direction to depth of 1cm and 1.5ml of 1:80000 lignocaine with adrenalin was deposited. an eighteen gauge needle was inserted from first point upward, inward and forward at 45 degree angle to corresponding plane during injection until feel joint space by decrease the resistance to the needle this approach to the upper joint compartment and approximately 2 ml ringers lactate solution deposited to distend the upper joint compartment (ujc). a second needle was inserted in second point backward, upward and inward to correspond the area of articular eminence to establish a free flow of irrigating solution from the ujc.the joint was irrigated with at-least 200 ml of ringer’s lactate solution. during the procedure patients were advised to keep the mouth open to distend the jointand then at the end of lavage 1 ml of ha was injected, see figurein page 3. both needles were removed and patients were advised for soft diet and nsaid (olfen 100 mg once daily) prescribed for 3 days with prophylactic antibiotic augmentin 625mg three times daily. post-operatively follow up period for 4 months, with 1st follow-up visit at 1 month from 1st injection procedure and 2nd followup visit 3 months after 2nd injection procedure with all the parameters for tmj functions measured with the same technique. the criteria for success was no pain(vas) equal to 0, clicking absent and maximum mouth opening ranged from (35-45)mm. j bagh college dentistry vol. 27(2), june 2015 efficacy of arthrocentesis oral and maxillofacial surgery and periodontics 107 (a) (b) (c) (d) (e) figure 1: the procedure of arthrocentesis with injection of hyaluronic acid. (a)the drawn line from mid tragus of the ear to the lateral canthus of eye (holmlund-hellsing line); (b) the two needles procedure; (c) and (d)irrigation with ringer`s lactate with the spurt of the solution from the second needle during the lavage; (e)injection of 1 ml of ha. results this study included 60 patients, there were 40 females (60.6%) and 20 males (33.4%), their ages ranged from 18 years to 45 years with a mean age of 31.5 years . all patients received the same treatment modalities with follow up period for 4 months. pre-treatment, treatment and follow up data were collected. the evaluation between different follow up results was done by (f-test) and mcnemar chi square test. the results were considered significant if p value < 0.05. description and statistics of data: 1 –pain level : the studied data elicited from avs showed significant reduction in pain from (6.25 to2.1) at 4months follow up with a (p value<0.01), with success rate (95%).the data of pre-treatment and post-treatment for degree of pain are illustrated in table (1). table 1: the comparison of pre-treatment and post-treatment for the degree of pain anova post-treatment pre-treatment p-value 2nd follow-up visit (3 month) 1st follow-up visit (1 month) sd mean % no. sd mean % no. sd mean % no. f-test=53.58 p<0.01 hs 0.134 2.12 33.4% 28.3% total 20 improved 17 0.198 4.35 100% 66.6% total 60 improved 40 0.312 6.25 100 60 vas pain * (vas) score = visual analogue score, * highly significant improvement in pain (p value <0.01), *success rate in pain improvement 95% 2 – joint clicking all patients (100%) included in the study were suffering from joint clicking. the study revealed complete tmj clicking sound disappearance in 57 patients (95 %) , while no change in joint clicking in 3 patients (5 %) at 4 months following treatment , (p value < 0.01), as demonstrated in table (2). table 2: comparison of pre-treatment and post treatment for tmj sound clicking. p-value non improved patients total improved patients post-treatment pretreatment patients improved at 2nd follow up visit (3 month) patients improved at 1st follow up visit (1 month) chisquare=23.4 p<0.01 hs * 3 57 7 50 60 no tmj clicking 5% 95% 11.7% 83.3% 100% % *highly significant improvement in sound clicking (p value <0.01), *success rate in sound clicking improvement 95% 3 – maximal mouth opening(mmo) initial measurements of maximal mouth opening revealed a limited mouth opening in only 20 patients included in this study.this study demonstrates a success rate of 100% in complete improvement in mmo, (p value < 0.01), as illustrated in table (3). j bagh college dentistry vol. 27(2), june 2015 efficacy of arthrocentesis oral and maxillofacial surgery and periodontics 108 table 3: comparison of pre-treatment and post treatment for maximum mouth opening evaluation p-value 2nd follow up visit (3 month) 1st follow up visit (1 month) pretreatment chi-square=19.6 p<0.01 hs * 20 20 20 no. mouth opening evaluation 40mm 35.7mm 30mm mean * normal mmo = 35 – 45 mm., *highly significant improvement in mmo (p value <0.01). discussion in the present study the mean age was 31.5 years ranged between 18-45 years old with maximum age group ranging from 26 to 30 years. this can be explained that certain age groups have a greater risk for developing tmjd than others. the most prevalent age groupfortmjd are people between the 2nd and 3rd decades. the condition is extremely uncommon after the age of 55 years and the reduced prevalence of tmjd signs and symptoms in older age groups supports the probability that most tmjd are self-limiting. these results are in agreement with edmond lt et al (7) and blasberg b and greenberg ms et al (2) studies who showed the same results.the result of sex distribution in the present study, showed evidence of high predilection to female, with female to male ratio of 2:1. this can be explained by the fact that females suffered higher levels of pain and dysfunction, and greater persistence of symptoms over a longer time.as with most other health conditions, females are more likely to seek treatment for the problem more than males, leading to the erroneous assumption that females have a higher incidence of tmd. this study was in agreement with researches of steven g. et al 20078that showed functional estrogen receptors have been identified in the female tmj but not in the male tmj. estrogen may also promote degenerative changes in the tmj by increasing the synthesis of specific cytokines, whereas testosterone may inhibit these cytokines. all patients had improvement in symptoms related to the intraarticular derangement and increased mandibular movements. results are in agreements with studies done by guarda-nardini 9, puffer et al 10. lavage of the upper joint space reduces pain by removing inflammatory mediators from the joint, increasing mandibular mobility by removing intra-articular adhesions, eliminating the negative pressure within the joint, recovering disc and fossa space and improving disc mobility, which reduces the mechanical obstruction caused by the disc displacement.this is in agreements with researches of carvajal and laskin 11 and totsuka 12.the final outcome of this study explain safety of ringer lactate and sodium hyaluronate, no serious complications, no side effects and patient could be tolerant under local anesthesia, just mild to moderate pain due to injection and enhancement inflammatory process (normal healing) according to mechanism of action of sodium hyaluronate. hyaluronic acid (ha) is a very important component of the articular cartilage and has a significant role in maintaining the articular lubrication and nutrition for the articular tissues and these results were in agreement with other studies like in umut tuncel (13) and luca guarda-nardini et al(14). the effectiveness of arthrocentesis with injection of hyaluronic acid in this study was based on 3 clinical parameters: reduction in pain and clicking sound during function and increase in maximum mouth opening. many researchers and clinicians have reported the results of series of patient treated with arthrocentesis and they are uniformly positive.in this study all patients were suffering from tmj pain. their pain score was equal to 6.25 (ranging from 5 to 8). at 1st follow-up visit the mean of pain score reduced to 4.35 (ranged from 3 to 5) for all the patients. for 40 patients (66.6%) the mean of pain score was 0 (complete relief after single injection only), the remaining 20 patients (33.4%) need a 2nd injection. the study data elicited from (avs) showed significant reduction in pain from (6.25 to 2.1) with a (p value<0.01) with success rate (95%). these results are in agreement with studies that performed by nitzan et al15,16 who described the high success rate (95%) in 39 cases treated with arthrocentesis only. the study data elicited significant improvement in mmo of patients (p value < 0.01), with success rate (100%).these results are in agreement with studies that performed bynitzan et al (15,16) which report a 3 years long term outcome for 39 patients with closed lock tmj in which high success (95 %) was achieved with the average mean for mmo (23.1 to 44.3mm ) with a p value < 0.01. in the present study all the patients (60 patients) were suffering from tmj clicking.at 1st follow-up visit 50 patients (83.3 %) show significant disappearance of tmj clicking. at 2nd follow-up visit 7 patients (11.6 %) show significant disappearance of tmj clicking. from total 60 patients only 3 patients (5%) showed no improvement of joint clicking. the final outcome j bagh college dentistry vol. 27(2), june 2015 efficacy of arthrocentesis oral and maxillofacial surgery and periodontics 109 of the study showed significant tmj clicking sound disappearance in 57 patients (95 %) with a p value < 0.01.in this study the success rate of arthrocentesis for joint clicking was similar to sato et al (17) show absence of clicking in 52 patients (88 %) from the total number of patients (59) that were included in his study.kanayama k et al (18) reviewed 25 treated cases with absent of clicking in represent of 97% success rate at duration 6 month. as conclusion; in this study, the technique of arthrocentesis using sodium hyaluronate injection, used in patients who presented with internal derangement, showed therapeutic benefits, simplicity, safety, patients acceptance of injection technique and lack of significant side effects and complications. all patients who were refractory to the conservative methods and psychologically depressed due to lack of proper treatment reported subjectively improvement in pain levels, improvement in joint clicking episodes and improvement in mouth opening with great psychological benefit. references 1. dworkin s, leresche l. research diagnostic criteria for tempormandibular disorders: review, criteria, examinations, and specifications, critique. j craniomandib disord 1992; 6: 301-35. 2. blasberg b, greenberg ms. burket's oral medicine diagnosis and treatment. 10th ed. new york: bc decker inc.; 2003. 3. nardini g, stifano m, brombin c, salmmaso l, manfredini d. a one year series of arthrocentesis with hyaluronic acid injection for tmj osteoarthritis.oral surgery med oral pathol oral radiol endod 2007; 103: e14-e22. 4. santos gs, calado r, sousa ne, gomes jb. arthrocentesis procedure: using this therapeutic maneuver for tmj closed lock management: j craniofac surg 2013; 24: 1347-9. 5. fader kw, et al. pressurized infusion of sodium hyaluronate for closed lock of tmj. part one: a case study. craniomandib pric 1993; 11: 68. 6. marshall kw. the current status of hulan. therapu. for the treatment of osteoarthritis. todays therapeutic trends 1997; 15: 99-108. 7. silverman sol jr., eversole l, truelove e. essentials of oral medicine. new york: bc decker; 2001. 8. abubaker ao, benson kj. oral and maxillofacial surgery secrets. 2nd ed. mosby; 2007. 9. guarda-nardini l, stifano m, brombin c, salmaso l, manfredini d. temporomandibular joint pain: relationship to internal derangement type, osteoarthrosis, and synovial fluid mediator level or tumor necrosis factor-alpha. oral surg oral med oral pathol oral radiol endod 2000; 90: 442-9. 10. puffer p, rudisch a, gassner r. temporomandibular joint pain: relationship to internal derangement type, osteoarthrosis, and synovial fluid mediator level or tumor necrosis factor-alpha. oral surg oral med oral pathol oral radiol endod 2000; 90: 442-9. 11. carvajal wa, laskin dm. long-term evaluation of arthrocentesis for the temporomandibular joint. j oral maxillofac surg 2000; 58: 852-5. 12. yura s, totsuka y. relationship between effectiveness of arthrocentesis under sufficient pressure and conditions of the temporomandibular joint. j oral maxillofac surg 2005; 63:225-8. 13. tozoqlu s, al-belasy fa, dolwick mf. a review of techniques of lysis and lavage of the tmj. br j oral maxillofac surg 2011; 49: 302-9. 14. guarda-nardini l, ferronato g. arthrocentesis of the temporomandibular joint: a proposal for a singleneedle technique. oral surg oral med oral pathol oral radiol endod 2012; 96:467-5. 15. nitzan d. arthrocentesis for management of severe closed lock of the temporomandibular joint: current controversies in surgery for internal derangement of the temporomandibular joint, atlas oral maxillofac surg clin north am 1994; 6: 245. 16. nitzan dw, samson b, better h. long-term outcome of arthrocentesis for sudden-onset, persistent, severe closed lock of the temporomandibular joint. j oral maxillofac surg 1997; 55:151-7. 17. sato s, oguri s, y amaguchi k, kawamura h, motegi k. effect of pumping with injection of sodium hyaluronate and other factors related to outcome in patient with non-reducing disc displacement of the tmj. int j oralmaxillofacial surg 2001; 30: 194-8. 18. kaneyama k, segami n, shin-ichi t, fujimura k, sato j, nagao t. anchored disc phenomenon with a normally positioned disc in the temporomandibular joint: characteristics and behaviour. br j oral maxillofac surg 2007; 45: 279-283. skeletal anterior facial heights changes among adolescent subjects of class l normal occlusion j bagh college dentistry vol. 29(3), september 2017 the effect of among among pedodontics, orthodontics and preventive dentistry 93 the effect of bracket ligation method on canine retraction akram f. alhuwaizi b.d.s., m.sc., ph.d (1) esraa salman jasim b.d.s., m.sc. (2) abstract: aim: this study aimed to compare different types of ligation methods to obtain maximum tooth movement with the least undesirable rotation. methods: titanium brackets bonded to acrylic canine teeth were ligated to straight stainless steel (ss) archwires using four ligation methods (figure-o and figure-8 elastics, ss ligatures, and leone slide ligatures). the teeth with the ligatures in place were stored in a water bath at 37ºc for 1 day, 1 week, 2, 4 or 6 weeks before testing. the teeth were retracted through softened wax along the archwire and the amount of tooth movement and degree of rotation were measured. results: slide ligatures showed the highest distance of tooth movement and degree of canine rotation followed by figure-o elastics, while figure-8 elastics showed the least amount of retraction and degree of rotation. ss ligatures showed moderate tooth movement with a minimal degree of rotation. conclusions: the study recommends the use of loose ss ligatures for canine retraction in sliding mechanics, while slide elastic ligatures are best used in leveling and aligning stage of crowded teeth since they showed reduced friction with the archwire. keywords: elastic, ligatures, friction, canine retraction. (j bagh coll dentistry 2017; 29(3):93-99) introduction during orthodontic treatment of extraction cases by sliding the canine along archwire, frictional force is generated at the bracket/ archwire/ ligature interface. to obtain an efficient orthodontic treatment, the applied force should be enough to overcome frictional force and the remaining part of force sufficient to induce a biological response within periodontal ligaments to get the desired tooth movement. approaches to avoid or minimize the effect of ligatures on frictional resistance include self-ligating brackets, differential placement of conventional elastomeric ligatures on special brackets or by using lubricated elastomeric modules or loosely tied stainless steel ligatures. not only is a pure bodily distal movement of the canine difficult to achieve with so-called sliding mechanics, the canine will also rotate because the force application is not through the center of resistance of the tooth in the labiolingual direction. a moment is necessary to counteract tooth rotation. this moment is exerted by the ligature tying the archwire to the bracket. because of the risk of friction, the ligature tie cannot be very tight. also, the ligature will probably yield during the control intervals, resulting in rotation of the canine during its distal movement (1). (1) prof., department of orthodontics, college of dentistry, university of baghdad. (2) assist. prof., department of orthodontics, college of dentistry, university of baghdad. thorstenson and kusy (2) found that ligation with loosely tied stainless steel ligature wires eliminated friction. but, iwasaki et al. (3) reported that consistent ligation forces are difficult to attain with stainless steel ligatures even for a trained operator and loose stainless steel ligation was not associated with lower frictional forces than tight stainless steel ligation. elastomeric modules are adversely affected by the oral environment, demonstrate stress relaxation with time, and exhibit great individual variation in properties. also, size and cross-section of elastomeric ligatures have an effect on friction (4,5). edwards et al. (6) showed that elastomeric ligatures tied in figure-8 pattern gave significantly greater mean static frictional forces than the other ligation techniques, while teflon-coated ligatures produced the lowest mean static frictional forces. leone slide ligature was introduced recently. it is manufactured with a special polyurethane mix by injection molding. once the ligature is applied on the bracket, the interaction between ligature and slot form a tube-like structure, which allows the archwire to slide freely (7). the aim of the study was to compare between four different types of ligation methods (figure-o elastics, figure-8 elastics, stainless steel ligatures and leone slide ligatures) regarding the distance of canine retraction and the degree of canine rotation after retraction and to correlate between the distance moved and the rotation obtained for each ligation method. j bagh college dentistry vol. 29(3), septem 2017 the effect of among among pedodontics, orthodontics and preventive dentistry 94 materials and methods a freshly extracted human permanent maxillary canine tooth was used as a replica for fabrication of one hundred similar acrylic teeth for standardization of all teeth dimensions and avoid any surface area differences could affect our results. five copper boxes (88 x 48 x 30mm) each with eight brass posts (30 x 8 x 4mm) were used. the posts were fixed at a distance of 10mm from the walls of metal box to have a uniform amount of heat distribution through the wax. the wax used in this study was an equal mixture of baseplate wax and utility wax melted and mixed together (8,9). a molar tube (titanium, slot .018x.030, dentaurum) was attached to each post being 7mm under the upper edge of post. this level will keep the apex of the acrylic teeth at a distance of 6 mm from the base of the metal box to avoid friction between the apex of tooth and the base during canine retraction. a bracket (titanium, slot .018x.030, dentaurum) was bonded to each acrylic tooth with cyanoacrylate adhesive material in a standardization manner by the use of a specially fabricated mold. then, the acrylic canine teeth were inserted in the copper box by ligating their brackets to a .018x.025 ss archwire passing through the molar tubes by the use of elastic ligature. the copper box was put on a flat table horizontal to the floor and checked by the pendulum fixed on both sides of the box as shown in figure 1. an equal mixture of baseplate wax and utility wax was prepared in accordance with previous studies (8,9) and poured into the boxes as three successive layers to compensate for cooling shrinkage, so that at the end a flat surface was obtained about 2mm gingival to the cemento-enamel junction of the teeth. figure 1: test apparatus with different bracket ligations. after cooling, the archwires were changed with .016”x.022” stainless steel (dentaurum) and was cinched back at both ends wire for stabilization. then in each box the four brackets were ligated with different ligature types by using a mathieu artery forceps making four groups: group 1: ligature elastics in figure-o (silver-metallic, dentaurum). group 2: ligature elastics in figure-8 (silver-metallic, dentaurum). group 3: slide leone elastic ligatures (leone orthodontic products). group 4: preformed short stainless steel ligature wire ties (.010, dentaurum), twisted 8 turns then untwisted 90 degrees and the excess was cut and tucked behind the archwire (10-13). the boxes were then immersed in distilled water at a temperature of 37°c in a water bath to simulate the environments of temperature and humidity of oral cavity until testing time. according to the time of storage 5 subgroups were identified (24 hours, one week, two weeks, four weeks, and six weeks). each subgroup composed of five teeth. because the molar tube represented the position of the second premolar, special hooks were custom made to enter in the molar tubes to standardize the distance between the hook and the canine bracket hook at 19mm (12mm for the coil spring length and 7mm for the activation). the hook was custom hand made from .016”x.022” spring hard stainless steel straight wire. at the end of the storage period the temperature of the water bath was raised to 50°c for mild softening of wax and the boxes were kept in the water bath for one hour to allow temperature to equilibrate inside the wax of the assembly (8). then niti closed coil spring (12mm rematitan, dentaurum) were quickly placed for the 4 types of ligature at the same time as shown in figure 2 to minimize the difference in starting time for them as possible. springs were replaced after three runs, because it was reported that the springs decayed by the seventh run (9). the boxes were kept in the water bath at 50°c for 20 minutes and then chilled. the distance from the molar tube to the bracket was measured using a dental vernier. the difference between the measurements before and after testing was regarded as the amount of tooth movement. then a top view image was taken by a digital camera to measure the degree of rotation of each tooth. this image was imported into fotocanvas program where a line was drawn along the bracket wings and another one along the archwire. the angle j bagh college dentistry vol. 29(3), september 2017 the effect of among among pedodontics, orthodontics and preventive dentistry 95 between the two lines was measured as shown in figure 3. finally, the copper boxes were cleaned from the wax and the whole procedure was repeated for the other time interval until all five storage times were tested. it is worth mentioning that practical research steps have been done in orthodontic lab in college of dentistry/ baghdad university. anova test was used to examine any significant difference between more than two groups and lsd test was used to find any statistical significant difference between any two groups. p values of less than 0.05 were regarded as statistically significant as follows: p>0.05 ns non-significant 0.05≥p>0.01 * significant 0.01≥p>0.001 ** highly significant p≤0.001 *** very highly significant a. figure-o elastic ligature b. figure-8 elastic ligature c. stainless steel ligature d. slide elastic ligature figure 2: canine retraction by niti closed coil spring for the four groups. figure 3: measuring canine rotation. results concerning the distance moved by the teeth, after one-day storage of the ligatures the highest amount of tooth movement was with slide elastics followed by ss ligatures, then figure-o elastics and lastly figure-8 elastics as shown in table 1. after one week the same sequence of ligation methods was found. while, after 2 weeks the sequence changed where slide elastics remained in the lead, but was followed by figure-o elastics, ss ligatures and lastly figure-8 elastics. this sequence remained the same for the 4 and 6 weeks storage periods. anova test showed highly significant differences between the methods of ligation for each time interval and hence lsd test between each pair of ligation methods was done (table 2). figure-8 elastics showed significantly less tooth movement than all the other 3 ligation methods at all time intervals, except for with ss ligatures at 6 weeks. while, slide elastics presented significantly higher tooth movement than all the 3 ligation methods at all the 5 time intervals except for a statistically non-significant difference between slide elastics with ss ligatures at the first day and with figure-o elastics at 2 weeks storage. on the other hand, figure-o elastics started at the first day in the middle being significantly different from all the other three ligation methods. at the 1 week period the figure-o elastics approximated the reading of ss ligatures being statistically nonsignificant. at two weeks it increased even more to be non-significantly different from the slide elastics, j bagh college dentistry vol. 29(3), septem 2017 the effect of among among pedodontics, orthodontics and preventive dentistry 96 but significantly higher than figure-8 elastics and ss ligatures. at 4 and 6 weeks periods, the amount of tooth movement for figure-o elastics dropped to be significantly lower than slide elastics and significantly more than figure-8 elastics and ss ligatures. the time of the storage had a statistically significant effect on all types of ligation elastics but not on ss ligatures and that is clear in table 1. anova test showed highly significant differences between the different time intervals for all ligation methods except ss ligatures. lsd test was made to find the differences between each two successive time intervals (table 1). the differences between one day and one week were generally weak and only significant for figure-o elastics, while the differences between one and two weeks were highly significant for the three elastics. the differences between two and four weeks were significant for figure-o and figure-8 elastics, while between four and six weeks were weak and only significant for figure-8 elastics. lsd test was not computed for ss ligature because the result of anova test was non-significant. concerning tooth rotation, the maximum rotation was seen with slide elastics in all time intervals followed by figure-o elastics, while the least was with figure-8 ligation and ss ligatures (table 3). anova test were a highly significant difference at each time intervals differences between different methods of ligation and the results. so an lsd test was made to find the difference between each two different ligation methods (table 4). slide and figure-o elastics showed significantly more rotation than figure-8 elastics and ss ligatures for all time intervals. slide elastics showed more rotation than figure-o elastics at all time intervals. however, this difference was non-significant at 1 day period but statistically significant at 1, 2, 4 and 6 weeks periods. the degree of tooth rotation was statistically non-significant between figure-8 elastics and ss ligatures at all time intervals, where rotation was higher for figure-8 elastics than for ss ligatures except for 1 week period where the readings where comparable. the effect of storage time on degree of rotation is displayed in figure 1, where there is a tendency to increased rotation with time for figure-o and slide elastics. however, figure-8 elastics and ss ligatures showed a different picture. anova test showed significant differences in the degree of rotation between the 5 time intervals for figure-o and slide elastics only, so lsd test was made for them only where only slide ligatures showed a significant increase in rotation from 1 day to 1 week (table 3). discussion slide elastics showed significantly higher tooth movement than all the other ligation methods at all time intervals, which may be attributed to that when the slide elastics is applied on the bracket, the interaction between the ligature and the slot form a tube-like structure which allows the archwire to slide freely and achieve a large amount of tooth movement (7); unlike the other three types of ligatures which make a direct contact with the archwire increasing friction. figure-8 elastics showed significantly less tooth movement than all the other 3 ligation methods at all time intervals, because of the higher stretching of the elastic making a greater force of ligation which makes an intimate relationship between the bracket slot and the archwire increasing friction. this is in agreement with the findings of previous studies (2,10,12). after one day, tooth movement with figure-o elastics lower than ss ligatures. this may be attributed to that the elastic ligatures were stretched during placement on the bracket wings creating more ligation force than the loose ss ligatures. this result agrees with bednar and gruendeman (12), iwasaki et al. (3) and khambay et al. (14) who showed that elastomers induced more friction and archwire seating force than slackened steel ligatures but disagree with riley et al. (15) and schumacher et al. (11) who showed that ss ligatures produce more friction than elastomers. this diversity of agreement with previous researches on the difference between figure-o and ss ligatures may be because consistent ligation forces are difficult to obtain with ss ligatures even for a well-trained operator (3). after one-week period, figure-o elastics approximated the reading of ss ligatures. at 2, 4 and 6 weeks it increased even more, to approximate slide elastics but significantly higher than ss ligatures. this is attributed to that figure-o elastics are greatly affected by storage in water because elastomeric material undergo swelling and slow hydrolysis and this leads to filling of the voids in the rubber matrix by water where the water act as a plasticizer which facilitates slippage of polymeric chains past each other, eventually force decay occurs as explained by young and sandrak (14). this is in agreement with the results of andreasen and bishara (17) and nikolai (18). j bagh college dentistry vol. 29(3), september 2017 the effect of among among pedodontics, orthodontics and preventive dentistry 97 table 1: descriptive statistics (mean ±s.d.) of the distance moved (in mm) with anova and lsd tests for the difference between the time intervals. material 1 day 1 week 2 weeks 4 weeks 6 weeks anova lsd (difference between time intervals) f$ p level 1d–1w 1w–2w 2w–4w 4w–6w figure-o 2.840 ±0.261 3.160 ±0.230 4.340 ±0.207 4.020 ±0.164 4.040 ±0.167 47.283 0.000*** 0.025* 0.000*** 0.025* 0.881 figure-8 1.780 ±0.311 2.080 ±0.228 2.940 ±0.261 2.500 ±0.374 2.980 ±0.228 16.949 0.000*** 0.113 0.000*** 0.025* 0.015* slide 3.560 ±0.371 3.840 ±0.391 4.500 ±0.122 4.420 ±0.164 4.560 ±0.230 13.023 0.000*** 0.127 0.001** 0.654 0.435 ss ligature 3.380 ±0.327 3.200 ±0.245 3.460 ±0.321 3.360 ±0.167 3.200 ±0.187 1.006 0.428 $ d.f.=24; d=day; w=week table 2: difference between the distance moved according to the ligation method at the five time intervals by anova and lsd tests. anova lsd (difference between materials) f p level o 8 o s o ss 8 s 8 ss s ss 1 day 31.278 0.000*** 0.000*** 0.003** 0.017* 0.000*** 0.000*** 0.387 1 week 33.501 0.000*** 0.000*** 0.002** 0.825 0.000*** 0.000*** 0.002** 2 weeks 47.639 0.000*** 0.000*** 0.306 0.000*** 0.000*** 0.003** 0.000*** 4 weeks 63.480 0.000*** 0.000*** 0.016* 0.000*** 0.000*** 0.000*** 0.000*** 6 weeks 64.425 0.000*** 0.000*** 0.001** 0.000*** 0.000*** 0.109 0.000*** $ d.f.=19; o=figure-o; 8=figure-8; s=slide; ss=ss ligature table 3: descriptive statistics (mean ±s.d.) of the degree of rotation (in degrees) with anova and lsd tests for the difference between the time intervals. material 1 day 1 week 2 weeks 4 weeks 6 weeks anova lsd (difference between time intervals) f$ p level 1d–1w 1w–2w 2w–4w 4w–6w figure-o 13.566 ±2.074 14.512 ±2.025 16.118 ±1.177 16.580 ±0.692 16.038 ±1.391 3.309 0.031* 0.350 0.120 0.645 0.589 figure-8 3.792 ±1.626 3.354 ±0.363 3.894 ±0.929 2.852 ±0.630 2.316 ±0.777 2.358 0.088 slide 15.546 ±1.423 18.942 ±1.338 18.260 ±2.337 19.088 ±1.198 19.458 ±0.820 5.463 0.004** 0.002** 0.483 0.396 0.702 ss ligature 1.738 ±0.736 3.486 ±0.999 2.838 ±1.581 2.248 ±0.553 2.076 ±0.352 2.668 0.062 $ d.f.=24; d=day; w=week table 4: difference between the degree of rotation according to the ligation method at the five time intervals by anova and lsd tests. anova lsd (difference between materials) f$ p level o 8 o s o ss 8 s 8 ss s ss 1 day 100.309 0.000*** 0.000*** 0.059 0.000*** 0.000*** 0.051 0.000*** 1 week 177.504 0.000*** 0.000*** 0.000*** 0.000*** 0.000*** 0.877 0.000*** 2 weeks 126.666 0.000*** 0.000*** 0.050* 0.000*** 0.000*** 0.311 0.000*** 4 weeks 603.271 0.000*** 0.000*** 0.000*** 0.000*** 0.000*** 0.255 0.000*** 6 weeks 495.006 0.000*** 0.000*** 0.000*** 0.000*** 0.000*** 0.683 0.000*** $ d.f.=19; o=figure-o; 8=figure-8; s=slide; ss=ss ligature j bagh college dentistry vol. 29(3), septem 2017 the effect of among among pedodontics, orthodontics and preventive dentistry 98 storage time significantly affected tooth movement with all types of elastomeric ligatures but not ss ligatures. this may be attributed to that swelling and hydrolysis will occur because of decomposition and leaching of some element from elastic (16) and prolonged contact with water leads to weakening of the intermolecular attraction forces of the chains since it acts as a plasticizer (19,20). this is especially true for stretched elastic ligatures as found by al-faham (19) and al-mothaffar and al-khafaji (20) who reported a significantly faster breakdown of elastics when stretched compared with non-stretched. figure-o elastics significant increased the amount of tooth movement in relation to storage time from one day, one week and two weeks successively. but the difference between 4 weeks and 6 weeks was non-significant because the maximum force decay occurs until four weeks as shown by hershey and reynolds (21) who demonstrated that the average force remaining 25-35% of the initial force with simulated tooth movement. on the other hand, figure-8 elastics showed a nonsignificant difference only between one day and one week, but showed highly significant differences after one week until six weeks. this is because figure-8 elastics are over-stretched causing full engagement of archwire in bracket slot (10). after one week, the elastic force drops but is still enough to fully engagement of archwire in bracket slot and hence does not significantly affect the amount of tooth movement. slide elastics presented a non-significant difference between the successive time intervals with the exception of a significant difference between one week and two weeks periods. this may be because slide elastics are not stretched during their placement on the brackets. hence, they need more time of contact with water to undergo hydrolysis until two weeks storage time. this agrees with al-faham (19) who found that the effect of stretching is more than the effect of water sorption on force decay. concerning the degree of rotation of the tooth, slide elastics allowed for more tooth rotation which may be because its design makes it fit on bracket slot without any pressure on archwire (tube like structure); allowing the bracket to rotate. the same can be seen in figure-o elastics, although they are stretched over the bracket wings and press on the archwire but do not provide enough force to produce the adequate anti-rotation moment. this agrees with bednar and gruendeman (12) who stated that during canine rotation, the elastic merely stretch and this prevent the wire from being completely seated in bracket slot. on the other hand, ss ligatures produced significantly less tooth rotation than figure-o and slide elastics, because throughout the range of axial rotation the ss ligatures seated the wire tightly in the bracket slot, and this produces enough moment to reduce canine rotation during sliding mechanics which agrees with bednar and gruendeman (12) who stated that the ss ligated brackets produce moments approximately 2.5 times than the elastomeric ligated brackets. figure-8 elastics showed a similar manner, because it is highly stretched over the bracket causing full engagement of archwire in bracket slot (10) even during canine retraction which produces a large moment to counteract tooth rotation. the difference between figure-o and slide elastics was non-significant in the first day because the maximum amount of force decay occur in the first day for the stretched figure-o elastics approximating the properties of the unstretched slide elastics which need prolonged contact with water to undergo hydrolysis (19). this difference became statistically significant for the 1, 2, 4 and 6 weeks period when the elasticity of slide elastics was affected. while the difference between figure-8 elastics and ss ligature was non-significant because they both cause full engagement of archwire in bracket slot which produce large anti-rotation moments that reduce canine rotation. storage time affects the degree of rotation through its effect on the force of ligation. hence, it was found that there is a significant difference for figure-o and slide elastics with the time intervals because with prolong contact with water and temperature, it undergo more force decay which lead to more tooth rotation (16). when breaking up the time intervals, figure-o elastics show non-significant increase of tooth rotation between successive time intervals till 4 weeks. this is consistent with our previous finding of increased tooth movement with increased storage time. these findings were small and statistically nonsignificant may be because elastomeric materials lose about 50-75% of their force in the first day so the degree of rotation in first day was not much different from the other time intervals because only about 1015% of force will be lost in the other time intervals (16) so there is no much difference in degree of rotation between them. slide elastics also showed a tendency to increased canine rotation and tooth movement with increased j bagh college dentistry vol. 29(3), september 2017 the effect of among among pedodontics, orthodontics and preventive dentistry 99 storage time. the amount of rotation was significantly different between the first day and first week because as explained earlier the slide elastics being unstretched required prolonged contact with water to undergo hydrolysis and force degradation (19,20). on the other hand, the effect of storage time on figure-8 elastics and ss ligatures was non-significant because it fully engages the archwire into the bracket slot which minimizes tooth rotation (10). conclusions 1. ss ligatures are preferred for canine retraction with sliding mechanics because they give moderate tooth movement with minimal tooth rotation. 2. the new leone slide ligature elastic ligature show the highest amount of tooth movement but with the highest degree of tooth rotation. hence, it can be used successfully in leveling and aligning stage. references 1. ziegler p, ingervall b. a clinical study of maxillary canine retraction with a retraction spring and with sliding mechanics. am j orthod dentofac orthop 1989; 95(2): 99-106. 2. thorstenson ga, kusy rp. effect of ligation type and method on the resistance to sliding of novel orthodontic brackets with second–order angulation in the dry and wet states. angle orthod 2003; 73(4): 418-30. 3. iwasaki lr, beatty mw, randall j, nickel jc. clinical ligation forces and intaoral friction during sliding on a stainless steel archwire. am j orthod dentofacial orthop 2003; 123(4): 408-15. 4. chimenti c, franchi l, giuseppe mg, lucci m. friction of orthodontic elastomeric ligatures with different dimensions. angle orthod 2005; 75(3): 421-5. 5. griffiths hs, sherriff m, ireland aj. resistance to sliding with 3 types of elastomeric modules. am j orthod dentofacial orthop 2005; 127(6): 670-5. 6. edwards gd, davies eh, jones sp. the ex vivo effect of ligation technique on the static frictional resistance of stainless steel brackets and archwires. br j orthod 1995; 22(2): 145-53. 7. baccetti t, franchi l. friction produced by types of elastomeric ligatures in treatment mechanics with the preadjusted appliance. angle orthod 2006; 76(1): 211-6. 8. tanne k, matsubara s, shibaguchi t, sakuda m. wire friction from ceramic brackets during simulated canine retraction. angle orthod 1991; 61(4): 285-92. 9. ryan r, walker g, freeman k, cisneros gj. the effects of ion implantation on rate of tooth movement: an in vitro model. am j orthod dentofac orthop 1997; 112(1): 64-8. 10. hain m, dhopatkar a, rock p. the effect of ligation method on friction in sliding mechanics. am j orthod dentofacial orthop 2003; 123(4): 41622. 11. schumacher ha, bourauel c, drescher d. the effect of ligature on the friction between bracket and archwire. fortschr kieferthopadie 1990; 51(2): 106-16. 12. bednar jr, gruendeman gw. the influence of bracket design on moment production during axial rotation. am j orthod dentofac orthop 1993; 104 (3): 254-61. 13. meling tr, qdegaard j, holthe k, segner d. the effect of friction on the bending stiffness of orthodontic beams: a theoretical and in vitro study. am j orthod dentofac orthop 1997; 112(1): 41-9. 14. khambay b, millett d, mchugh s. archwire seating forces produced by different ligation methods and their effect on frictional resistance. eur j orthod 2005; 27(3): 302-8. 15. riley jl, garrett sg, moon pc. frictional forces of ligated plastic and metal edgewise brackets. j dent res 1979; 58(1): a21. 16. young j, sandrik jl. the influence of preloading on stress relaxation of orthodontic elastic polymers. angle orthod 1979; 49(2): 104-9. 17. andreasen gf, bishara se. comparison of alastic chain with elastics involved with intra-arch. molar to molar forces. angle orthod. 1970; 40(3): 151-8. 18. nikolai rj. material behavior of the orthodontic appliance bioengineering analysis of orthodontic mechanics. 1st ed. lee and febiger, philadelphia, 1985. 19. al-faham amm. force decay of elastomeric ligatures. master thesis, college of dentistry, university of baghdad, 2002. 20. al-mothaffar nm, al-khafaji aj. force degradation of elastic ligatures during chlorhexidine application. iraqi orthod j 2006; 2(2): 22. 21. hershey hg, reynolds wg. the plastic module as an orthodontic tooth-moving mechanism. am j orthod dentofac orthop 1975; 67(5): 554-62. 22. alhuwaizi af. in-vitro simulated tooth movement with self-ligating and conventional brackets. iraqi orthod j 2009; 5(1): 1-7. الملخص .هبدوران غير مرغوب القصوى بأقلسنان اال للحصول على حركة ربطال طرقلى مقارنة أنواع مختلفة من هدفت هذه الدراسة إ خلفية: سااتامال طاارق مختلفااة بأساال بالحاصاارا ربااط ال. قولميااةت حاصاارا خاا ل ماان فوالذلااةساا أب ُربِطااتم مشاةاار كرللياا مصاانوعة ماان اأأنياااب الطريقةةة: سااعة 44لماد سايليزلة 33 بدرجةتم تخزلن اأسنان مع اأربطة في حمام مائي ثم (.س لد ليون مطاطا وأ أوأربطة فوالذلة 8 و o يةكلعلى ا مطاط) وتام قيااك كمياة حركاة سايليزلة 05بدرجة لين ةمع خ ل سل الاأسنان على طول تسحشبادها تم أسابيع قشل االختشار. 6أسابيع أو 4أسابيع 4أسشوع 1 اأسنان ودرجة الدوران. أظهر أقل مسافة سحب ودرجاة 8ةكل ا . بينما مطاطo ةكل ا ألنياب ثم تلتها مطاطلحركة ودرجة دوران مسافة كشر أ س لد مطاطا أظهر: النتائج ماتدلة بدرجة دنيا من الدوران بسشب حصر السل الفوالذي داخل ةق الحاصر . حركةأظهر الفوالذلة ربطةاأ أما .دوران باستامال اأربطة الفوالذلة المرتخية لسحب الناب باالنزالق الميكانيكي بينما لتم تفضيل استامال الس لد المطاطي في مرحلة توصي الدراسة :االستنتاجات االحتكا مع السل الفوالذي. خفضت هانأ التسولة واالستواء من ع ج اأسنان المزدحمة bashar f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 irradiation effect oral diagnosis 48 irradiation effect of 780-805nm diode laser on wound healing in mice warkaa m. al-wattar, b.d.s, m.sc. (1) bashar h. abdulluh, b.d.s, m.sc., ph.d. (2) ali s. mahmmod, m.b.ch.b., f.i.c.m.s. (3) abstract background: wound healing is a complicated, interactive, integrative process involving cellular and chemotactic activity, the release of chemical mediators and associated vascular response which includes number of phases: inflammatory phase, proliferative phase and remodeling phase. low level laser therapy can be more effective in the three overlapping phases of wound healing. biostimulation appears to have an effect on the cellular level, by increasing cellular function and stimulating various cells. the aim of present study was to evaluate histologically the effect of 780-805 diode laser the intensity of inflammation and pattern of epithelization in mice model. material and methods: the experimental study was performed on ninety six white albino mice. an incision of 1.5cm length was done on the face side of each mouse. then the animals were divided into two main groups; control group which didn’t receive laser irradiation while the other group was the lased group which exposed to single dose of 360j/cm of 780-805nm diode laser. animals were subdivided into four subgroups according to healing periods. histological specimens were taken at 1st, 3rd, 7th and 14th day for microscopical examination concerning inflammatory cells infiltration and epithelial cell layer thickness. results: results show obvious reduction in inflammatory cell infiltration and more epithelization in laser treated wounds compared with control wounds. statistical analysis showed a significant difference between two groups. conclusion: low level diode laser (790-805nm) has beneficial effects in enhancement of soft tissue wound healing process histologically. keywords: low level laser therapy (lllt), photobiomodulation. (j bagh coll dentistry 2013; 25(special issue 1):48-52). :الخالصة تعتبر عملیة شفاء الجروح عملیة معقدة تتطلب فعالیة خلویة وتجاذب كیمیاوي وافراز وسائط كیمایویة واستجابة وعائیة والذي یتضمن عدة -: خلفیة الموضوع ویظھر تاثیر االستحاثة . ادخلة لعملیة الشفاءویعتبر العالج باللیزر الواطئ الطاقة فعاال اكثر في المراحل الثالث النات. التھابیة تكاثریة واعادة تشكیل:مراحل نانومیتر 805-780ھدف الدراسة الحالیة ھو التقییم النسیجي لـاثیر اللیزر . البایولوجیة على المستوى الخلوي من خالل زیادة فعالیة الخالیا وتحفیز انواع الخالیا .على شدة االلتھاب وطریق تشكیل الطبقة الطالئیة في جروح الفار ثم قسمت الحیوانات الى مجموعتین رئیسیتین اللیزر . سم 1.5فأرا ابیض تعرضوا جمیعھم لعملیة جرح قطعي في ناحیة الوجھ بطول 96استخدم : المواد والطرائق ذ العینات من كل مجموعة في بعد ذلك تم اخ. 2سم\جول 360تعرضت مجموعة اللیزر لجرعة واحدة من اشعاع اللیزر بعد عملیة الجرح مباشرة بجرعة . والقیاس .الیوم االول والثالث والسابع والرابع عشر من ایام الشفاء اظھرت نقصا واضحا في انتشار الخالیا االلتھابیة وزیادة سمك الطبقة الطالئیة في مجموعة اللیزر مقارنة بمجموعة القیاس والنتائج االحصائیة بینت النتائج : النتائج تینفرقا واضحا بین المجوع تسریع عملیة شفاء الجروح نسیجیا لھ تأثیر واضح على نانومیتر805-780ان استعمال اللیزر الواطئ الطاقة: اجاتتنتاالس introduction laser energy is a sort of electromagnetic energy which, depending on its source, can be converted into luminous energy, visible or not. laser arrays are, therefore, a highly concentrated noninvasive kind of non-ionizing radiation that, in contact with different tissues, promotes thermic, photochemical, and nonlinear effects(1) .several studies have indicated that laser arrays at low frequencies (low-level laser therapy, lllt) are quite helpful in modulating different biological activities, such as trophic regenerative(2) antiinflammatory(3) and analgesic effects(4) it has been suggested that biological properties of visible spectra of lllt are probably a result of cellular photoacceptors and signaling pathway stimulation by light. (1)ph.d. student. department of oral diagnosis. college of dentistry. university of baghdad. (2)assistant professor. department of oral diagnosis. college of dentistry. university of baghdad. (3)assistant professor. laser institute of postgraduated study. university of baghdad. therefore, the absorption of monochromatic visible radiation by components of the cellular respiratory chain accelerates the transfer of electrons from nadh and fadh2 (produced in the krebs cycle) to oxygen molecules to form (with the aid of protons) water molecules, harnessing the energy released by this transfer to the pumping of protons (h+) from the matrix to the intermembrane space. this gradient of protons formed across the inner membrane by this process of active transport forms a miniature battery. consequently, this mechanism increases the mitochondrial atp production and protein synthesis. furthermore, it was proposed that cytochrome c oxidase is the primary photoacceptor for both the red and infra-red range in mammalian cells (1) .wound healing is a biological response to tissue injury. this highly controlled repair process is characterized by the movement of specialized cells into the wound site, in order to provide key signaling events required for the influx of connective tissue cells and a new j bagh college dentistry vol. 25(special issue 1), june 2013 irradiation effect oral diagnosis 49 blood supply(5,6) despite the fact that wound healing represents a reparative response to tissue insult, a long-term or overinduced inflammatory reaction is extensively implicated in promoting atypical patterns of healing, such as fibrosis, strictures, adhesions, and contractures (7). previous reports have demonstrated that lllt is efficient in stimulating cellular proliferation and collagen synthesis in biological assays (8). variations in the wavelength and dose of phototherapy, as well as optical characteristics inherent to every single tissue, have been pointed out as relevant factors to assure the success of the laser-induced biological modulation. moreover, the latter variable has been currently considered particularly important to evaluate the extent of the interaction between laser irradiation and cells (10). materials and methods ninety –six white albino mice weighting 150200gm; 3-6 months old were used in this study. the animals were divided into 2 groups, control group which includes 48 animals and lased group includes 48 animals. laser system: laser system which is used in this study is an infrared (ga al as) diode laser, class iv laser (k-laser, italy), its wavelength is 790805 nm, mode of operation is modulated cw, maximum cw power is 4 w. animal irradiation: the surgical field was done on the check side. an incision was done with 1.5cm length. the animals of lased group had been irradiated by an infrared diode laser while the wound of the control group didn’t irradiated. the animals were divided into 4 groups related to healing period intervals: the specimens were taken from both groups in 1st, 3rd, 7th and 14th days and prepared for histological examination. method of assessment: 1. evaluation of inflammatory cells infiltration:-it was made by examining many sections of each specimen by measuring the number of inflammatory cells per square of grid at power field (x40) magnification. the inflammatory cells that were investigated are (neutrophil, lymphocyte, macrophage and eosinophil). 2. evaluation of epithelial cell layers thickness:it was done by examining the surface of wound at the incision site of each specimen using computerized microscope by measuring ruler within the software of light microscope (micros, astruia). the measurement of epithelial thickness was performed by measuring the distance from outermost keratin layer to innermost basal layer of epidermis. in the current study, the descriptive and inferential statistics (independent ttest and analysis of variance (anova) two way tests) were used in order to assess and analyze the results. statistical probability (p) <0.05, 0.001. results as showed in [table 1], the intensity of the inflammatory response was severe in absolutely all the cases of in control group in day 1 and 3. besides, the leukocyte infiltrate was predominantly composed of neutrophils and lymphocytes, characterizing an acute inflammatory reaction. in general, neutrophils were distributed along the wound surface, particularly within the fibrinous exudate membrane [figure 1 and 3] whereas lymphocytes were observed in the deeper regions of the specimens. macrophages and eosinophils were observed in little number in day 1 and increased till day 7 to incline gradually till day 14. the wounds of the irradiated animals in day 1 presented a severe inflammatory response. neutrophils and lymphocytes were also the most frequently observed leukocytic cells, but they appeared to be less abundant in this group in day 3, particularly neutrophils [figure 2 and 4]. however, the pattern of distribution of these leukocytes throughout the wound was nearly similar to that seen in control group. in addition, the macrophages and eosinophils of laser group presented the very same profile found in control group. at the 7th day, the intensity of the inflammatory response in control group was predominantly mild, although it still presented macrophages. besides, lymphocytes were the less abundant leukocyte and some blood vessels neoformation were observed spread out in the connective tissue, but this vascular component was less obvious as in laser group [figure 5].the inflammatory response subsided in laser group; [table 1]. moreover, a remarkable neoformation of capillary blood vessels, mainly in the deeper regions of the healing area, was also observed [figure 6]. even though the presence of neutrophils could still be seen in some cases, their presence was not remarkable in any case. as indicated in the [table 1], epithelization was seen to be highest level at the 7th day of surgery in both control and laser group [figure 5 and 6 ] was seen in all the specimens but the laser group showed thicker epithelial layer than control group . on the 14 th day, epithelial neoformation was less and irregular in control group of the wound surface [figure 7]. on the other hand, significant neoformation of the recovering epithelial tissue was observed in almost all the animals of laser group more than control group, but it was seen to be complete remodeled than that seen in day 7[figure 8]. j bagh college dentistry vol. 25(special issue 1), june 2013 irradiation effect oral diagnosis 50 table 1: comparison between control and laser group (independent t-test) day parameter control laser t-test p-value sig. m sd m sd 1 neutrophil 33.33 23.02 35.5 32.27 -.19 .85 ns lymphocyte 8 10.92 8.58 9.93 -.14 .88 ns macrophage .58 1 2.75 3.76 -1.93 .666 ns eosinophil 0.5 .522 1.5 2.46 -1.37 .18 ns epithelization 69.34 25.87 102.95 38.28 -2.52 .01 s 3 neutrophil 35.5 32.27 10.58 9.49 3.84 .002 hs lymphocyte 16.92 18.4 8 8.27 1.53 .154 ns macrophage 5.92 5.19 2.75 3.77 1.82 .08 ns eosinophil .33 .49 .75 .75 -1.6 0.123 ns epithelization 86.31 38.63 138.5 49.48 -2.88 .008 hs 7 neutrophil 15.92 20.95 11.92 10.97 .59 .56 ns lymphocyte 17.16 21.23 6.17 2.97 1.75 .08 ns macrophage 20.75 20.85 4.25 3.27 2.71 0.01 s eosinophil .17 .38 .33 .49 -.92 0.36 ns epithelization 112.65 51.92 207.04 175.15 -1.79 0.08 ns 14 neutrophil 7.66 12.11 8.75 6.04 -.28 0.952 ns lymphocyte 10.66 10.21 5.00 2.92 1.68 .107 ns macrophage 3.33 2.57 1.41 .9 2.44 .023 s eosinophil 1 1.7 .41 .51 1.13 .27 ns epithelization 112.07 64.19 98.22 .75 .6 .55 ns fig.5: control group/day7 fig.1: control group/day1 fig.2: lased group/day1 fig.3: control group/day3 fig.4: lased group/day3 fig.6: lased group/day7 fig.7: control group/day14 fig.8: lased group/day14 j bagh college dentistry vol. 25(special issue 1), june 2013 irradiation effect oral diagnosis 51 discussion the induction of repair in wounds represents a dynamic process that involves the integrated actions of many cell types, extracellular matrix and chemical mediators. the inflammatory reaction represents the earliest event to take place after tissue injury, whose main function is to eliminate eventual microorganisms and provide wound cleaning. subsequently, biological events, such as formation of new capillary blood vessels associated with progressive deposition and remodeling of collagen fibers will end in a complete repair of the injured area (6). inflammatory response is absolutely required to provide wound healing, but its long-term persistence has been considered one of the most important reasons of delay in the healing process (11). despite recent advances in improving the wound-healing process, many studies have still been performed looking at new strategies to stimulate the biological events that comprise the repair phenomenon (12). studies have demonstrated that laser arrays present some biostimulatory properties apparently able to accelerate wound healing of soft tissue injuries (13, 14) . wavelengths in the 600-700 nm range have been employed in treating superficial tissues, such as cutaneous or mucosal wounds, whereas wavelengths between 780 and 950 nm have been applied in deep seated tissue insults, like bone fracture healing (15). however, both positive and negative results have been reported in the literature, probably as a result of different protocols of photobiomodulation employed in as in vitro and in vivo biological assays. the beneficial effects of adequate protocols of photobiomodulation on wound healing can be explained by considering its ability to stimulate several biological mechanisms responsible for triggering many phases of the repair of soft tissue injuries, including the induction of cytokines and expression of growth factors by keratinocytes and stromal cells (1). on the other hand, negative responses can be a result of an unsuitable interaction between laser light and tissue components of the wound-healing process due to the application of inappropriate protocols of photoirradiation (10). the dosage of energy applied in the photobiomodulation procedure is currently considered as an extremely relevant parameter to provide a significant improvement in repair (10). a specific protocol of laser irradiation at 790-805nm has been previously reported which showed to be truly effective in improving the wound-healing process, possibly by promoting photostimulation of a variety of cell subsets, such as fibroblasts, myofibroblasts, and epithelial cells, at the same time modulating the inflammatory response (14). in this study, we investigated the effectiveness of a increased energy dosage of laser irradiation in stimulating wound healing. we made use of the very same general protocol employed in a previous work (14). in order to afford subsequent reliable comparisons between our findings and those recently reported. within the protocol of photobiomodulation applied in this study, lllt was able to induce a certain decrease in the intensity of the inflammatory reaction at both 1st and 3ed days after surgical procedures. in fact, a remarkable antiinflammatory activity of lllt has been reported within other different protocols (16,17). the findings suggest that, this protocol of lllt had shown ability to modulate the inflammatory response; it asserted that its effect might truly favor the acceleration of the healing process. however, this protocol of lllt appeared to be successful in influencing the immunoinflammatory response, i.e., once it reduced the amount of neutrophils at the earlier stages of the wound-healing process irradiated wounds. this modulatory effect of lllt over the acute inflammatory response might be a result of an important inhibitory role played by laser arrays, on the synthesis of prostaglandin, a chemical mediator widely supposed to provide chemotactic signals for polymorphonuclear neutrophils (18). therefore, lllt might provide a short term acute inflammatory response in earlier stages of wound healing, which certainly would favor the process of wound repair. epithelization is the process where epithelial cells on the edges of the wound or in residual skin appendages lose contact inhibition and migrate into the wound area. simultaneously, additional epithelial cells are provided by the proliferation of immature keratinocytes in the basal layer .as keratinocytes are supposed to be a source of a variety of cytokines involved in remodeling the collagen fibers deposited at the final stages of repair, the development of epithelial lining is considered a relevant step of wound healing. furthermore, the epithelial bridge is also responsible for removal of scab by dissolution of its attachments to the underlying connective tissue (6). in this study, the process of wound surface epithelization was enhanced by lllt in both stages of wound healing, although the advances in epithelial neoformation had been less apparent in 8 than in 14 days. these findings are supported by previous studies asserting that lllt was shown to be effective in stimulating the migration of keratinocyte along the healing wound surface, probably as a result of the release of growth factors such as egf (epidermal growth factor) j bagh college dentistry vol. 25(special issue 1), june 2013 irradiation effect oral diagnosis 52 and tgf-á (transforming growth factor alpha) by irradiated macrophages (1,18,19). furthermore, lllt was recently proved to act directly on keratinocyte-promoting epithelial cell proliferation in vitro (19). this may be the reason for increased epithelization to be more intense in final than in early stages of the healing process .once the wound is "cleaned," the inflammatory phase of the wound repair is gradually substituted by the proliferating phase as the healing process takes place. the latter is characterized by migration of fibroblasts into the wound area and consequent deposition of the collagen fibers required for the repair of tissue injury (11,6). the results obtained in this study by using a 790805nm of dose of 360j/cm2 can assert that this protocol of photobiomodulation was successful in improving certain steps of wound healing, such as inflammatory profile and epithelization. as conclusions; the lllt protocol tested in this study improved wound healing in vivo. nevertheless, further investigations are necessary to provide data about possible extrapolations of its effectiveness in wound repair in human beings. references 1. hamblin mr, demidova tn. mechanisms of lowlevel light therapy. proc spie 2006; 6140: 1-11. 2. kreisler m, christoffers ab, willershausen b, d'hoedt b. low-level 809 nm gaalas laser irradiation increases the proliferation rate of human laryngeal carcinoma cells in vitro. lasers med sci 2003;18:1005 3. ribeiro ms, silva f, araújo ce, oliveira sf, pelegrini cm, zorn tm, et al. effect of low-intensity polarized visible laser radiation on skin burns: a light microscopy study. j chin laser med surg 2004; 22: 59-66. 4. nes ag, posso mb. patients with moderate chemotherapy-induced mucositis: pain therapy using low intensity lasers. int nurs rev 2005; 52: 68-72. 5. gillitzer r, goebeler m. chemokines in cutaneous wound healing. j leukoc biol 2001; 69: 513-21. 6. diegelmann rf, evans mc. wound healing: an overview of acute, fibrotic and delayed healing. front biosci 2004; 9: 283-5. 7. van zujilen pp, angeles ap, kreis rw, bos ke, middelkoop e. scar assessment tools: implications for current research. plast reconstr surg 2002; 109: 110822. 8. leung mc, lo scl siu fk, so kf. treatment of experimentally induced transient cerebral ischemia with low energy laser inhibits nitric oxide synthase activity and up-regulates the expression of transforming growth factor-beta 1. lasers surg med 2002; 31: 283-8. 9. mendez t, pinheiro a, pacheco m, nascimento p, ramalho l. dose and wavelength of laser light have influence on the repair of cutaneous wounds. j clin laser med surg 2004; 22: 19-25. 10. karu t, kolyakov sf. exact action spectra for cellular responses relevant to phototherapy. photomed laser surg 2005; 23: 355-61. 11. clark ra. wound repair-overview and general considerations. in: clark ra (ed). the molecular and cellular biology of wound repair. new york: plenum press; 1996. p. 3-50. 12. gibran ns, boyce s, greenhalgh dg. cutaneous wound healing. j burn care res 2007; 28: 577-9. 13. whelan ht, smits rl jr, buchman ev, whelan nt, turner sg, margolis da, et al. effect of nasa lightemitting diode irradiation on wound healing. j clin laser med surg 2001; 19: 305-14. 14. ribeiro ma, albuquerque rl, ramalho lm, bonjardim lr, da cunha ss. immunohistochemical assessment of myofibroblasts and lymphoid cells during wound healing in rats submitted to laser photobiomodulation at 660 nm. photomed laser surg 2009; 27: 49-55. 15. yasukawa a, hrui h, koyama y, nagai m, takakuda k. the effect of low reactive-level laser therapy (lllt) with helium-neon laser on operative wound healing in a rat model. j vet med sci 2007; 69: 799806. 16. conlan m, rapley jw, cobb cm. biostimulation of wound healing by low-energy laser irradiation: a review. j clin periodontol 1996; 23: 492-6. 17. freitas ac, pinheiro al, miranda p, thiers fa, vieira al. assessment of inflammatory effect of 830 laser light using c-reactive protein levels. bras dent j 2001; 12: 187-90. 18. sakurai y, tamaguchi m, abiko y. inhibitory effect of low-level laser irradiation on lps-stimulated prostaglandin e2 production and cyclooxygenase-2 in human gingival fibroblasts. eur j oral sci 2000; 108: 29-34. 19. eduardo fp, mehnert du, monezi ta, zezell dm, schubert mm. eduardo cp, et al. cultured epithelial cells response to phototherapy with low intensity laser. lasers surg med 2007; 39: 365-72. mohammed f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of pedodontics, orthodontics and preventive dentistry 132 the effect of tooth shape ratio on mandibular incisors arrangement in iraqi adult subjects sami k. al-joubori, b.d.s., m.sc. (1) mohammed nahidh, b.d.s., m.sc. (2) abstract background: this study aimed to assess the effect of tooth shape ratio on mandibular incisor arrangement. materials and methods: the sample included dental casts of some dental students and orthodontic patients having class i dental and skeletal patterns with normal occlusion and severe crowding. the sample was divided into two groups according to the severity of crowding into: group i had class i normal occlusion with mild or no crowded mandibular dentition and group ii had class i malocclusion with severe crowded mandibular dentition. each group comprising of 40 subjects (20 males and 20 females). the mesio-distal and facio-lingual crown diameters were measured manually for each cast using modified vernier caliper gauge. descriptive statistics were obtained for the measurements for both genders; independent samples t-test was performed to evaluate the gender difference in each group and to evaluate the groups' difference in total sample. results and conclusions: the results showed that there is non-significant genders difference in both groups. generally, the mesio-distal and facio-lingual dimensions were higher in severely crowded mandibular incisor group. neither facio-lingual dimension nor the tooth shape ratio has significant influence of the mandibular incisor arrangement and the mesio-distal dimension is the most important factor. keywords: tooth shape (peck and peck) ratio, normal occlusion, severe crowding. (j bagh coll dentistry 2013; 25(special issue 1):132-136). introduction the four mandibular incisors are the teeth most prone to positional irregularity. studies have shown this, and no clinical orthodontist will deny it (1,2). there are many potential factors in the etiology of mandibular anterior crowding. tooth size variation is one of them (3). although a relationship between crown dimensions and the presence or absence of tooth irregularity is generally recognized, the exact nature of this association has, as yet, eluded investigators (4,5). peck and peck (6) conducted a study to answer the question, "do naturally well-aligned mandibular incisors possess distinctive dimensional characteristics?" two samples of american white female young adults of european ancestry were utilized. the first group consisted of forty-five subjects carefully selected for their "perfect" mandibular incisor alignment. the second sample was a control population group of seventy subjects. mesio-distal (md) and faciolingual (fl) crown diameters of the mandibular incisors were recorded for each subject in both groups by direct intraoral measurement. the results of this study indicated that mandibular incisors in perfect alignment are significantly smaller mesio-distally and significantly larger facio-lingually. from these findings it becomes apparent that tooth shape (md and fl dimensions) is a determining factor in the presence and absence of mandibular incisor crowding. (1)assistant professor. department of orthodontics, college of dentistry, university of baghdad (2)lecturer. department of orthodontics, college of dentistry, university of baghdad in 1972, peck and peck (7) conducted, on the same sample of the past study, a study to present the scientific basis and the clinical application of a new method for detecting and evaluating tooth shape deviations of the mandibular incisors. they proposed an index for clinical orthodontics utilizes an md/fl ratio. it is constructed by dividing the mesio-distal on facio-lingual crowns diameters multiplying by 100. they concluded that a substantial relationship existed between mandibular incisor shape and the presence and absence of mandibular incisor crowding and the well-aligned mandibular incisors had md/fl indices significantly lower than those-of crowded incisors. bau (8) carried out a study to investigate whether naturally perfectly aligned mandibular incisors differ significantly in their mesio-distal and facio-lingual dimensions and their mesiodistal-facio-lingual indices from naturally crowded mandibular incisors and whether associated with more ideal anterior intermaxillary tooth size indices than naturally crowded mandibular incisors. his results indicated that the mesio-distal dimension appears to demonstrate the most important distinctive difference between naturally aligned and naturally crowded mandibular incisor teeth. smith et al. (9) performed a study to answer the question of whether or not peck and peck ratios are more useful than simple measurements of incisor mesio-distal length. the results showed that the mesio-distal incisor lengths have slightly higher correlations with crowding than the shape ratios. j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of pedodontics, orthodontics and preventive dentistry 133 imai et al. (10) investigated the relationship between tooth shape ratio and incisor arrangement and found that there is no clear relationship between tooth shape ratio of the mandibular incisors and arrangement of the permanent incisors in japanese children. this study aimed to assess the effect of tooth shape ratio on mandibular incisor arrangement. materials and methods sample the sample included dental casts of some dental students and orthodontic patients having class i skeletal pattern according to foster (11) and class i normal occlusion and class i malocclusion (with severe crowding). the inclusion criteria 1. complete mandibular dentition (regardless the third molars). 2. approximal contact present among the mandibular incisors. 3. healthy gingival tissue with no gingivitis or periodontitis or any gum recession. 4. no history of abnormal habit. 5. no history of previous orthodontic treatment or maxillofacial surgery and facial trauma 6. no massive carious lesion or bulky restorations. the sample was divided into two groups according to the degree of the mandibular dental arch crowding (12): 1. the group 1: it includes (20 males and 20 females) with mild or no crowding. 2. the group 2: it includes (20 males and 20 females) with severe crowded mandibular dentition that is tooth size-arch size discrepancy of > 4mm. method history and clinical examination each subject is asked to seat comfortably on the dental chair and asked information about the name, age, origin, medical history, the history of facial trauma and orthodontic treatment. then they were asked to look forward horizontally (frankfort plane parallel to the floor) for clinical examination, extra-orally and intra-orally to check their fulfillment of the required sample selection. dental cast production impressions were taken for every subject with alginate impression material then poured with a prepared amount of stone. after setting of the dental stone, a base of plaster of paris was prepared and then the poured cast was inverted over it. after the final setting of the gypsum, the base was trimmed uniformly by trimmer and made ready for the measuring procedure. measuring procedure 1. assessment of the mandibular dental arch crowding the assessment of the mandibular dental arch crowding was obtained by measuring the discrepancy in millimeters between the dental arch space available and the dental arch space required which was as followed: calculation of dental arch space available to obtain the space available, a brass wire was extended from mesio-buccal cusp tip of first permanent molar on one side to that on the other side passing through the line of occlusion over the buccal cusps of the premolars, over the normal cuspal position of the canine and the incisal edge of mandibular incisors. then the wire was carefully straightened and measured with modified vernier caliper gauge to the nearest 0.1mm (13). calculation of dental arch space required the procedure of measuring the mesio-distal crown width was done as described by hunter and priest (14) as the greatest mesio-distal crown width of the teeth which was measured from the anatomic mesial contact point to the distal one. the measurements were made to the nearest 0.1 mm by using the modified sliding caliper gauge with pointed beak inserted in a plane parallel to the long axis of the tooth. the measurements started from the mandibular first permanent molar to the right central incisor on one side through to the corresponding tooth on the opposite side. after the mesio-distal crown width of each tooth was measured, the summation of these measurements in both right and left sides were calculated to determine the amount of the total mesio-distal crown width in the dental arch to calculate the space required. these measurements were used to quantify the dental arch length discrepancy by employing the basic equation: dental arch space available dental arch space required = arch length discrepancy. 2. measuring the diameters of the mandibular incisors the maximum mesio-distal diameter was usually found at or near the incisal edge while the maximum facio-lingual diameter was measured by placing the vernier tips gingivally. the index proposed for clinical orthodontics utilizes an j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of pedodontics, orthodontics and preventive dentistry 134 md/fl ratio. it is constructed in the following manner (7): index= mesio-distal diameter in mm. × 100 facio-lingual diameter in mm. statistical analyses all the data of the sample were subjected to computerized statistical analysis using spss version 19 computer program. the statistical analyses included: 1. descriptive statistics: means, standard deviations (sd) and statistical tables. 2. inferential statistics: independentsamples ttest for the comparison between both genders in each group and between the groups in total sample. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 * significant 0.01 ≥ p > 0.001 ** highly significant p ≤ 0.001 *** very highly significant results and discussion the results indicated in normal occlusion group (table 1), the mesio-distal and facio-lingual dimensions were higher in males, while the md/fl ratio was higher in females with a nonsignificant gender difference. on the other hand, in severe crowding group (table 2), the results showed that the mesio-distal and facio-lingual dimensions and md/fl ratio were higher insignificantly in males except mesiodistal dimension and md/fl ratio of mandibular right lateral incisor where were higher insignificantly in females. as there was no genders difference in both groups, the total sample was compared between the two groups (table 3) and the results showed that the mesio-distal and facio-lingual dimensions and md/fl ratio were higher in severe crowding group with varying degrees of significance regarding the md dimension only. the findings of this study are in contrary to that of peck and peck (6) who found that the mandibular incisors in perfect alignment are significantly smaller mesio-distally and significantly larger facio-lingually, while agree with bau (8), imai et al. (10) and agenter et al. (15) who found the same findings of the present study. this variability in the results may be attributed to the sample size and to the ethnic difference of other studies; in addition to that peck and peck (6) did their research on females only. reviewing the mean values of the variables measured in other studies, table 4 revealed that the md and fl dimensions are slightly larger in the iraqi sample while the tooth shape ratio is variable as it is affected by the md and fl dimensions. the conclusion that drawn from this study is that neither facio-lingual dimension nor the tooth shape ratio has significant influence of the mandibular incisor arrangement and the mesiodistal dimension is the major contributing factor for that. references 1. massler m, frankel jm. prevalence of malocclusion in children aged 14 to 18 years. am j orthod 1951; 37(10): 751-68. 2. berger h. the lower incisors in theory and practice. angle orthod 1959; 29(3): 133-48. (ivsl). 3. ballard ml. asymmetry in tooth size: a factor in the etiology, diagnosis and treatment of malocclusion. angle orthod 1944; 14(3): 67-70. (ivsl). 4. moorrees cfa, reed rb. biometrics of crowding and spacing of the teeth in the mandible. am j phys anthropol 1954; 12(1): 77-88. 5. mills lf. arch width, arch length, and tooth size in young adult males. angle orthod 1964; 34(2): 1249. (ivsl). 6. peck s, peck h. crown dimensions and mandibular incisor alignment. angle orthod 1972; 42(2): 14853. (ivsl). 7. peck h, peck s. an index for assessing tooth shape deviations as applied to the mandibular incisors. am j orthod 1972; 61(4): 384-401. 8. bau dj. mandibular incisor dimensions anterior intermaxillary ratio, in relation to mandibular incisor alignment. a master thesis. department of preventive dentistry, faculty of dentistry, university of sydeny, 1973. 9. smith rj, davidson wm, gipe dp. incisor shape and incisor crowding: a re-evaluation of the peck and peck ratio. am j orthod 1982; 82(3): 231-5. 10. imai h, kuwana r, yonezu t, yakushiji m. the relation between tooth shape ratio and incisor arrangement in japanese children. bull tokyo dent coll 2006; 47(2): 45–50 11. foster td. a textbook of orthodontics. 2nd ed. oxford: blackwell scientific publications; 1985. 12. ngan p, alkire rg, fields h jr. management of space problems in the primary and mixed dentitions. j am dent assoc 1999; 130(9):1330-9. 13. nance hn. the limitations of orthodontic treatment: i. mixed dentition diagnosis and treatment. am j orthod oral surg 1947; 33(4): 177-223. 14. hunter ws, priest wr. errors and discrepancies in measurement of tooth size. j dent res 1960; 39(2): 405-14. 15. agenter mk, harris ef, blair rn. influence of tooth crown size on malocclusion. am j orthod dentofac orthop 2009; 136(6):795-804. (ivsl). j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of pedodontics, orthodontics and preventive dentistry 135 table 1: descriptive statistics and gender difference in normal occlusion group teeth descriptive statistics genders difference male (n=20) female (n=20) total (n=40) mean s.d mean s.d mean s.d t-test p-value l at er al in ci so r left md 6.25 0.48 6.25 0.48 6.25 0.47 0 1 (ns) fl 6.73 0.43 6.69 0.43 6.71 0.42 0.3 0.77 (ns) ratio 93.05 7.33 93.72 8.64 93.39 7.91 -0.26 0.80 (ns) right md 6.07 0.45 6.26 0.37 6.16 0.41 -1.51 0.14 (ns) fl 6.67 0.35 6.54 0.43 6.6 0.4 1 0.32 (ns) ratio 91.19 7.67 96.06 7.68 93.63 7.97 -2 0.052 (ns) both md 6.16 0.57 6.25 0.42 6.2 0.44 -0.98 0.33 (ns) fl 6.69 0.39 6.61 0.43 6.65 0.41 0.9 0.37 (ns) ratio 92.12 7.46 94.89 8.16 93.51 7.89 -1.58 0.12 (ns) c en tr al in ci so r left md 5.63 0.38 5.59 0.48 5.61 0.43 0.29 0.77 (ns) fl 6.47 0.56 6.41 0.54 6.44 0.54 0.35 0.73 (ns) ratio 87.35 6.21 87.51 7.57 87.43 6.84 -0.07 0.94 (ns) right md 5.69 0.4 5.6 0.44 5.64 0.42 0.72 0.48 (ns) fl 6.49 0.44 6.3 0.52 6.4 0.48 1.25 0.22 (ns) ratio 87.82 5.5 89.24 8.73 88.53 7.24 -0.62 0.54 (ns) both md 5.66 0.39 5.59 0.45 5.63 0.42 0.71 0.48 (ns) fl 6.48 0.49 6.36 0.53 6.42 0.51 1.1 0.28 (ns) ratio 87.59 5.79 88.38 8.11 87.98 7.02 -0.5 0.62 (ns) table 2: descriptive statistics and gender difference in severe mandibular anterior teeth crowding group teeth descriptive statistics genders difference male (n=20) female (n=20) total (n=40) mean s.d mean s.d mean s.d t-test p-value l at er al in ci so r left md 6.42 0.3 6.33 0.26 6.37 0.28 1 0.32 (ns) fl 6.84 0.46 6.75 0.32 6.8 0.39 0.72 0.48 (ns) ratio 94.08 6.22 93.82 4.24 93.95 5.26 0.16 0.88 (ns) right md 6.35 0.24 6.47 0.38 6.41 0.32 -1.24 0.22 (ns) fl 6.82 0.41 6.61 0.4 6.71 0.42 1.67 0.10 (ns) ratio 93.29 5.56 98.21 7.21 95.75 6.83 -2.42 0.2 (ns) both md 6.38 0.27 6.4 0.33 6.39 0.3 -0.26 0.80 (ns) fl 6.83 0.43 6.68 0.36 6.75 0.4 1.71 0.09 (ns) ratio 93.69 5.84 96.01 6.25 94.85 6.12 -1.72 0.09 (ns) c en tr al in ci so r left md 5.84 0.24 5.84 0.28 5.84 0.26 0 1 (ns) fl 6.73 0.55 6.58 0.37 6.65 0.47 1.04 0.30 (ns) ratio 87.25 7.18 89.02 5.56 88.14 6.4 -0.87 0.39 (ns) right md 5.89 0.27 5.75 0.35 5.82 0.32 1.37 0.18 (ns) fl 6.67 0.45 6.6 0.38 6.63 0.41 0.57 0.57 (ns) ratio 88.46 5.04 87.34 5.67 88.9 5.33 0.66 0.51 (ns) both md 5.86 0.25 5.8 0.31 5.83 0.29 1.05 0.29 (ns) fl 6.7 0.5 6.59 0.37 6.64 0.44 1.17 0.25 (ns) ratio 87.86 6.15 88.18 5.61 88.02 5.85 -0.25 0.81 (ns) j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of pedodontics, orthodontics and preventive dentistry 136 table 3: mean values and comparison between normal and severe mandibular anterior teeth crowding groups tooth mean values group difference normal severe t-test p-value l at er al in ci so r left md 6.25 6.37 -1.44 0.16 (ns) fl 6.71 6.80 -0.99 0.33 (ns) ratio 93.39 93.95 -0.37 0.71 (ns) right md 6.16 6.41 -2.96 0.000 *** fl 6.60 6.71 -1.21 0.23 (ns) ratio 93.63 95.75 -1.28 0.20 (ns) both md 6.2 6.39 -3.08 0.002 ** fl 6.65 6.75 -1.55 0.12 (ns) ratio 93.51 94.85 -1.2 0.23(ns) c en tr al in ci so r left md 5.61 5.84 -2.90 0.000 *** fl 6.44 6.65 -1.87 0.06 (ns) ratio 87.43 88.14 -0.48 0.63 (ns) right md 5.64 5.82 -2.11 0.04 * fl 6.40 6.63 -2.36 0.21 (ns) ratio 88.53 88.9 0.44 0.66 (ns) both md 5.63 5.83 -3.55 0.001 *** fl 6.42 6.64 -2.98 0.3 (ns) ratio 87.98 88.02 -0.04 0.97 (ns) table 4: mesio-distal, facio-lingual dimensions and tooth shape ratio in different studies author(s) year country gender state no. central incisor lateral incisor md fl ratio md fl ratio peck and peck 1972 usa female perfect 90 5.16 5.84 88.4 5.68 6.29 90.4 control 130 5.39 5.72 94.4 5.91 6.11 96.8 bau 1973 australia male perfect 16 5.18 5.39 87.53 5.75 6.41 90.03 crowded 60 5.37 6.03 89.29 5.99 6.37 94.2 smith et al. 1982 usa male orthodontic patients 36 5.6 6 94 6.2 6.1 102 canada hutterite 50 5.2 6.3 83 5.8 6.5 90 usa female orthodontic patients 64 5.5 5.8 95 6 6.1 98 canada hutterite 42 5.1 6.1 85 5.7 6.2 91 imai et al. 2006 japan mixed normal 27 5.26 5.45 97.32 5.9 5.66 105.1 crowded 13 5.54 5.73 97.17 6.21 5.86 106.59 agenter et al. 2009 usa male good occlusion 42 5.31 5.91 5.78 6.28 malocclusion 90 5.53 6.13 6.08 6.38 present study 2013 iraq mixed normal 40 5.63 6.42 87.98 6.2 6.65 93.51 crowded 40 5.83 6.64 88.02 6.39 6.75 94.85 j bagh college dentistry vol. 31(4), december 2019 maximum bite force 1 maximum bite force in relation to maximum mouth opening among primary school children athraa hussein medhat (1) aseel haidar m.j. al haidar (2) abstract background: the vertical distance between the upper and lower incisal edge of the central incisors when the mouth is opened as wide as possible is called maximum mouth opening (mmo). any pathological change in the masticatory system had a direct effect on the maximal mouth opening. the aim of this study was to evaluate the relationship between the maximum bite force and the maximum mouth opening among group of children. materials and methods: four hundred children of both genders were included in this study, their age ranged from eight to ten years. anterior and posterior (right, left) bite force were measured using bite force sensor. maximum mouth opening was evaluated by electronic digital caliper. data was statistically analyzed by descriptive statistics and by using paired t‑test and chi‑square test. results: the value of maximum mouth opening was increased with the increasing of age in both genders; however, boys had higher value of maximum mouth opening than that of girls. a significant difference was found between genders among 9 years old children concerning the maximum bite force. a weak positive relation was observed between maximum mouth opening and maximum bite force among the boys in both of the age groups. conclusions: in this study, a significant positive correlation was found between maximum bite force and maximum mouth opening for boys, as they had higher mean value of maximum mouth opening and maximum bite force than girls. (received: 15/12/2018; accepted: 21/1/2019) introduction teeth have an important role in the masticatory system, as they form the occlusal area where the food particles are fragmented, so that the grinding force will depend on the total occlusal area and thus on the number of teeth (1-3). chewing performance and bite force can influence the development of masticatory function. chewing is a developmental function and its maturation occurs from learning experiences. if mastication is adequate, it gives stimulus for the proper function to normal development of maxilla and mandible. (1,4) masticatory function can be predicted by a number of parameters, including bite force (5)and occlusal contact area,the higher the bite force and the larger the occlusal contact area can aid in the more efficient mastication. on the other hand, reduced masticatory function may be related to the smaller occlusal contact area (6). maximum mouth opening which is the greater distance between the incisal edges of the upper and lower central incisors (at the midline when the mouth is open widely) (7) . it is a simple but important clinical parameter to conduct a thorough conventional oral examination and for the follow-up assessments of the diverse affections of the stomatognathic system. 1. master student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. 2. assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad limitation in the mouth opening is one of the early signs of some pathological and/or traumatic conditions that may affect the oral cavity, e.g. temporomandibular disorders (tmd) (8), odontogenic infections (9) trauma (10,11) , tumors (12), dental infections, craniofacial malignancies, fractures and myopathies (in the head and neck region) (13). all clinicians dealing with the oral cavity facing various problems when there is a limited mouth opening (14).till now there is no previous iraqi studies dealing with this subject .the aim of present study to identify the possible relationship between maximum bite force and maximum mouth opening among children for this reason this study conducted. materials and methods in total, 400 primary school children aged 8-10 years were selected from (1100) students at ten primary schools in al-khalis city/ diyala /iraq. after getting the approval from the scientific committee of the pedodontics and preventive dentistry department / college of dentistry/ university of baghdad, this cross sectional study was carried out during the period from the end of december 2017 until the end of february 2018. to conduct this study without obstacles, official permission was obtained from the general directorate of education of diyala governorate. aims of this study were explained to the school authority to obtain cooperation as much as possible and that was done by a formal document. a singed consent was gained from the j bagh college dentistry vol. 31(4), december 2019 maximum bite force 2 parents of each student participated in this study to get full information about the child (general health and age) and to examine their children as a part of the study sample without obligation. examination was done at the students, school. the students were examined intra and extraorally and the exclusion criteria were 1.children with uncooperative behavior 2.children with cleft lip and/or palate. 3. facial abnormalities.4. children who their teeth were present with: congenital defects or deformed teeth, missing, unerupted, or fractured permanent centrals, large carious lesions or presence of large restorations.5.children who had any prosthesis or orthodontic treatment.6.children with tmj problems. in this study, the bite force were measured using bite force sensor (loadstar sensor, usa).the device capacity was 100 kg. children were instructed to bite three times, as hard as possible, on the gauge sensor without moving the head .the measurement was done while the child was sitting on a chair, with straight head and back, when his frankfort horizontal plane was kept horizontal(15). biting force of each child was measured alternately three times for the posterior area (right and left) and the anterior area each at 10 seconds intervals and the average of the readings was assumed to be mbf of each child where the teeth at maximum intercuspation according to standard procedure (15). meanwhile, evaluation of the maximum mouth opening (mmo) was done by asking the child to open the mouth as wide as possible (16), while the child was seated comfortably in the chair resting their head against hard wall surface in an upright position. the maximum distance from the incisal edges of the maxillary and the mandibular central incisors at the midline (7) was measured by using electronic digital caliper (china). the values of the present study were subjected to statistical analysis by using spss version 20 (statistical package for social sciences) to specify the statistical differences between the two groups. p value of less than or equal the 0.05 level of significance was considered to be statistically significant. results table (1), shows the distribution of the sample according to their age and gender in relation to the maximum mouth opening (mmo). in both of the groups, the girls had the higher maximum value of mmo than that of boys. however, the value of the mmo was increased with increasing of the age in both genders. table (2), shows that although the maximum bite force (total) of 8 years boys was larger than that of girls, (106.4 ± 34.6, 104.3±31 respectively) the difference was not statistically significant. however, among the age group of 9 years the difference between genders concerning the maximum bite on the anterior area and maximum bite force (total) were statistically significant (p=0.01). as shown in table 3, a significant but weak positive correlation was found between (mmo) and mbf (total) among boys for both of the age groups. table (1): distribution of the study sample according to age and gender in relation to the maximum mouth opening variable maximum mouth opening 8 year 9 year boy girl boy girl number % 80 39% 97 49.7% 125 61% 98 50.3% range 25.40 28.40 25.90 25.60 minimum 22.00 22.00 24.30 25.00 maximum 47.40 50.40 50.20 50.60 mean± sd 37.53 ±4.65 37.51±4.93 39.39±4.76 38.83±5.29 j bagh college dentistry vol. 31(4), december 2019 maximum bite force 3 table (2): maximum bite force by age and gender mbf (r) =maximum bite force in the right side. mbf (l) =maximum bite force in the left side. mbf (a) =maximum bite force in the anterior area. mbf (total) = average maximum bite force. ns =not significant, s=significant, hs= highly significant, (significance level=p ≤ 0.05). table.3: pearson correlation coefficient of maximum mouth opening in relation to maximum bite force s=significant, ns=not significant (significance level=p ≤ 0.05). discusion maximum mouth opening is an important tools for dental clinicians as a preliminary evaluation .it is a relevant references for assessment of the masticatory functional status (7,17). in this study, the values of maximum mouth opening varied considerably among the children. it ranged from a minimum values (22 mm) among the 8 years old children (both boys and girls), to a maximum value which was (50.60 mm) among the 9 years old girls .the measurement of mmo of the present study come in accordance with that of other studies (1822). lower value of mmo (25.40 to 28.40) at the mixed dentition stage was reported by other studies (23, 24). this narrow range value could be due to the small-ranged age groups (8 9 years) of the current study. as reported by hirsh et al. (22), cortese et al (24) and vanderas (25) mmo was related to age, which was in agreement with the present study, which revealed that the mmo was increased with increasing age. in the present study, the significant difference between genders was present only among the age group of 9 years. meanwhile, gender differences concerning mmo were observed in a few studies (20, 26, 27), while other studies reported that there was no gender difference in the measurement of mmo among children, which disagreed with the present study (18, 24, 26, 28). the results of the present study showed that a significant difference was not found between genders in regard to the maximum bite force mbf on the posterior area (right and left side) among children in both of the age groups. however, gender difference concerning mbf (total) was significant only among the older age group. while some investigators did not find a difference in mbf between genders that disagree with present study (29-32) , a significant difference in bite force between boys and girls was reported by several studies (27, 33-35) by which the bite force of boys was considerably stronger than that of girls. results of the present study revealed that there was no clear relationship between the mmo and the mbf, which could be due to the age of the sample (children) and the sample size. however, fields et al.36 previously reported an associated between the presence of larger mouth opening and the presence of a stronger maximum bite force. however, this study was done among adults. conclusion based on the finding of present study, there was a significant weak positive correlation between maximum mouth opening (mmo) and maximum bite force (mbf total) among boys in both of the age groups as they had higher mean maximum mouth opening and maximum bite force than girls references 1. english jd, buschang ph, throckmorton gs. does malocclusion affect masticatory performance. angle orthod. 2002; 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(2) measurements of biting pressure in children. am j orthod oral surg 1940;26: 41−6. 32. ingervall b, minder c. correlation between maximum bite force and facial morphology in children. angle orthod 1997; 67:415−24. 33. shiau yy, wang js. the effects of dental condition on hand strength and maximum bite force. cranio 1993;11:48−54. j bagh college dentistry vol. 31(4), december 2019 maximum bite force 5 34. chen cs. the relationship between dental caries prevalence and the relative biting force in children. chin med coll j 1993;2:17−26. 35. fields hw, proffit wr, case jc, vig kw. variables affecting measurements of vertical occlusal force. j dent res 19 86; 65:135−8. الخالصة: (. كان ألي تغيير مرضي في mmoعندما يتم فتح الفم على أوسع نطاق ممكن تُسمى فتحة الفم القصوى ) االماميةلقواطع ا لية بين الحافة العلوية والسفلية المسافة العمودالمقدمة: األطفال. بين مجموعة منلفم لفتح اوالحد األقصى المضغ تأثير مباشر على فتحة الفم القصوى. هدفت هذه الدراسة إلى تقييم العالقة بين قوة العّضة القصوى طريقة األمامية والخلفية )اليمنى واليسرى( قوة العضةسنوات. تم قياس 10و 8( طفل من كال الجنسين في هذه الدراسة ، تراوحت أعمارهم بين 400المواد والطريقة: تم تضمين أربعمائة ) tاألقصى لفتح الفم بواسطة الفرجار الرقمي اإللكتروني. تم تحليل البيانات إحصائيًا عن طريق اإلحصاء الوصفي وباستخدام اختبار باستخدام جهاز استشعار قوة العضة. تم تقييم الحد المزدوج واختبار مربع كاي. مقارنة بالفتيان. تم العثور على اختالف كبير القصوىالفم ا ةأعلى لفتح النتائج: تم زيادة قيمة الحد األقصى لفتح الفم مع زيادة العمر في كال الجنسين. ومع ذلك ، كان لدى البنات قيمة لوحظ وجود عالقة إيجابية ضعيفة بين الحد األقصى لفتح الفم و قوة العض القصوى على المنطقة الخلفية وعلى المنطقة األمامية بين كل من الفئات العمرية ببين الجنسين فيما يتعلق سنوات . 8انب األيسر بين األوالد في الفئة العمرية من وقوة العض القصوى على الج ( وقوة العضة mmoى عالقة ضعيفة إيجابية ولكنها ليست كبيرة بين أقصى فتحة للفم )وص قالفم ال ة وفتح العض في هذه الدراسة كانت العالقة بين الحد األقصى لقوة االستنتاجات: ( وقوة العّضة القصوى mmoالفم ) تحإيجابي بين الحد األقصى لفوف يضعيوجد ارتباط سنوات من الفتيات بينما 9لبنين و سنوات ل 8عند mbf (l)القصوى )الجانب األيسر( (mbf.عند األوالد لكل من الفئات العمرية )المجموع( ) ، األطفال. فتحة الفم القصوى، العضة الكلمات المفتاحيه: قوة ma'an.doc j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 26 a comparison between the horizontal condylar and bennett angles of iraqi full mouth rehabilitation patients by using two different articulator systems (an in-vivo study) ma'an rasheed zakaria, b.d.s., m.s., ph.d. (1) abstract background: errors of horizontal condylar inclinations and bennett angles had largely affected the articulation of teeth and the pathways of cusps. the aim of this study was to estimate and compare between the horizontal condylar (protrusive) angles and bennett angles of full mouth rehabilitation patients using two different articulator systems. materials and methods: protrusive angles and bennett angles of 50 adult males and females iraqi tmd-free full mouth rehabilitation patients were estimated by using two different articulator systems. arbitrary hinge axis location followed by protrusive angles and bennett angles, estimation was done by a semiadjustable articulator system. a fully adjustable articulator system was utilized to locate the terminal hinge axis using a kinematic face bow followed by protrusive angles location by the aid of two square shaped transparent hard plastic protractors attached close to the condylar stylus of the articulator followed by bennett angles calculation according to the hanau formula. all results were subjected to statistical analyses. results: the two articulator systems scored protrusive angles for male patients greater than female patients which were non-significant for the fully adjustable articulator but they were significant for the semiadjustable articulator. non-significance existed between females of the fully adjustable articulator and males of the semiadjustable articulator while high significance was located between males of the fully adjustable articulator and females of the semiadjustable articulator. concerning bennett angles, the highest mean value belonged to the male group of the fully adjustable articulator, while the lowest scored by the female group of the semiadjustable articulator. highly significant differences were located between the bennett angle mean values of the groups. conclusion: using both articulators, the total mean values of the males were greater than the females regarding both horizontal condylar angles and bennett angles with the total means scored by the fully adjustable articulator being larger than those of the semi-adjustable type. using both articulators, the males' right and left condyles exhibited greater bennett angles than their female equivalents. the precision estimation of the horizontal condylar angles and bennett angles provided by the condylar axis protractors of the fully adjustable articulator render such type of articulators most suitable for treating full mouth rehabilitation cases. keywords: horizontal codylar angles, bennett angles, two articulator systems. (j bagh coll dentistry 2016; 28(1):2635). introduction the management of tooth wear, especially attrition, is becoming a subject of increasing interest in the prosthodontic literature, both from preventive and restorative points of view (1). focusing on the interactions between occlusion and brain function has been reported as brain activity may change depending on the strength of the movements in the oral and maxillofacial area. therefore, mastication and other movements stimulate the activity in the cerebral cortex and may be helpful in preventing degradation of a brain function (2). the relationship between the dental occlusion and temporomandibular disorders (tmds) has been one of the most controversial topics in the dental community (3). oral rehabilitation restores form and function and impacts on general health. teeth provide a discriminating senseof touch and directional specificity for occlusal perception, management of food with mastication and swallowing, and awareness of its texture and hardness. (1)professor, formerly in the department of conservative dentistry, college of dentistry, university of baghdad. it has been shown that optimum restoration design appears to be significant for bone remodeling and bone strains around implants with occlusal loading. load concentration increased with steeper cusp inclination and broader occlusal table and decreased with central fossa loading and narrower occlusal table size (4). the primary objective of rehabilitating occlusion is to improve stomatognathic function in patients experiencing dysfunction in mastication, speech, and swallowing as a consequence of tooth loss. the procedure of occlusal treatment involves improving the morphology and the stomatognathic function (5). mastering occlusion is the primary objective that must be achieved in order to restore the function of the dentition to last a lifetime (6). the most difficult and potentially threatening oral rehabilitationinvolves all of the teeth on one or both arches being prepared at the same time, or when the vertical dimension of occlusion being changed. diagnostic casts are a necessary aid in determining the characteristics of occlusion to be developed in the rehabilitated dentition. the preoperative occlusion must be observed carefully on j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 27 diagnostic casts. if most of the characteristics of the original occlusion are replaced in the rehabilitated occlusion, the treatment will seldom, if ever, fail. on the contrary, if steep incisal guidance is placed in the mouth of a person who previously had worn his or her teeth into a group function, failure may occur over a short time. if a dentition is restored into a centric relation occlusion, when the natural occlusion had a long shift from centric relation to centric occlusion, broken porcelain on anterior maxillary crowns or drifting anterior teeth within weeks or months of seating the rehabilitation have been observed (7). on april 27th, 1908 dr. norman g. bennett of london, england presented a paper on mandibular movements to the "royal society of medicine odontology section"; the article, originally published in the proceedings of the society that year, reprinted in the journal of prosthetic dentistry (8). specifically, he intended to show that no single fixed rotation center of the condyles exists, but that the center is constantly moving. that is, for any normal opening movement of the mandible, a succession of instantaneous centers of rotation occurs in a curved path. these paths vary among individuals. he attached small light bulbs to a mandibular framework, one over the condyle and another at the symphysis and used lenses to focus the images on the wall, where they were traced during mandibular motion onto a sheet of paper placed in the sagittal plane, and the focused spots were marked by bennett's brother at several intervals. bennett's conclusions were that there was an instantaneous center of rotation that varied with different condylar movements and position, rather than a solitary, fixed center of rotation. bennett made a secondary observation when spots were recorded in the frontal plane. he noticed a lateral shift in the position of the working condyle towards the side to which the movement was being made. in summary, he noted that when the mandible was moved bodily to one side, the condyle on the side of the movement rotated in place or moved slightly, and the opposite condyle (the side away from the movement) moved downward and forward. bennett's report was considered important to bring to the attention of the profession a concept that "balkwill" had discovered but had been neglected for over 40 years (9). the bennett path influences the positions of the cusps in their mesiodistal relation to each other on the working side. on the balancing side, the bennett path influences the height of the cusps as well as their position. it is important to record the path of the bennett movement and arrange the cusps of the teeth so that they can pass each other without clashing or climbing upon each other during function. at the same time, a continuous contact of these surfaces should be maintained in order they can efficiently perform their function of chewing without damage to the supporting structure (10). bennett angle is the angle formed by the sagittal plane and the path of the advancing condyle during lateral mandibular movements as viewed in the horizontal plane (11). the protrusive angle is the angle formed between the condyles of the mandible and a horizontal line passing through the condyles' centers when the mandible moves forward of centric position (viewed in the horizontal plane) (10). an analogue of the condylar guidance on an articulator is considered to be a necessary requisite in prosthodontics. condylar guidance is described as the mandibular guidance generated by the condyle and articular disc traversing the contour of the glenoid fossae or, synonymously, as the mechanical form located in the upper posterior region of an articulator that controls movement of the mobile member (12). the guidance inclination in semi-adjustable articulators is set either by individual protrusive or lateral inter-occlusal (ioc) registrations. studies have shown the unreliability of recording and reproducing the condylar guidance on these instruments. average value settings are used with mean inclinations of normal adult eminence morphology. reported average ioc registrations values of the condylar guidance inclination vary from 21-64 degrees. some advocated setting the condylar inclination at a flatter than average value to ensure disocclusion of the posterior teeth during excursions. however, if the individual inclination of the eminence is very steep or flat, guidance obtained from average value settings may differ sufficiently to cause problems in achieving particular clinical objectives, such as posterior disocclusion or balanced occlusion (12). the rotating condylar movement affects both the working and the nonworking sides but has its greatest effect on the working side. semiadjustable articulators do not have the ability to compensate for this movement. the fully adjusttable articulators can be so modulated that the pathway of the rotating condyle on the articulator will duplicate that in the patient (13). the fully adjustable articulator permits adjustment of both the bennett angle and the immediate side shift to duplicate these movements j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 28 of the patient's orbiting condyle. many semiadjustable articulators cannot duplicate this exact pathway since only flat surfaces (slot-track) are available to guide the condyle. when the exact characteristics of the orbiting condylar movement are duplicated, the correct groove placement and fossa width can be more precisely developed in a posterior fixed restoration (14). ultrasonic mandibular movement recorders have been used to record sagittal condylar inclinations which showed no difference when compared to mechanical pantograph recordings although the latter persistently under recorded the immediate side shift (15). protrusive movement recordings are also important in fully edentulous complete denture wearers and to be takeninto account during the final occlusal selective grinding for new sets of complete dentures (16). materials and methods fifty adult patients (25 females and 25 males) aged 30 to 65 years participated in the present study. all subjects had generalized loss of incisal and occlusal morphology due to attrition and faceting of teeth, extensive defective restorations, or multiple missing teeth, associated with moderate or severe ovd collapse.they were recruited from those seeking fixed prosthodontic work at the department of conservative dentistry, college of dentistry, university of baghdad and they didn't present signs of muscular or articular pain according to the examination criteria of the multiaxial research diagnostic criteria for tmds (rdc/tmd)since myofacial pain of the masticatory muscles can affect mandibular range of motion and spatial relationship between upper and lower jaws (17). full series of periapical x-rays and a panoramic radiograph were taken for each patient. for each patient, two sets of maxillary and mandibular irreversible hydrocolloid impressions (tropicalgin chromatic, zhermackspa, italy) were made and converted into stone casts. centric jaw relationship was made using aluwax (aluwax dental products co, michigan, usa) following dawson's technique (6) stressing that any perforated cr record due to premature tooth contact was discarded. all procedures for recording, mounting, and setting were done in the same session. arbitrary mandibular hinge axis location after feeling the condyle rotation, the axis was located within an average of 2 mm or less since the axis generally occurs near the center of the depression felt by the fingertip and it was marked as a dot by an indelible pencil (18). a measurement method was applied by placing a ruler on an imaginary line running from the patient's superior border of the tragus of the ear to the outer canthus of the eye. the arbitrary axis was marked on the skin at eleven mm anterior to the tragus (19). arbitrary face-bow record orientation of dental casts within a full sized articulator is an essential element in producing a realistic analogue of a patient. this process is facilitated by using a face-bow to record the orientation of maxillary arch relative to a patient's transverse hinge axis of the mandible. the maxillary cast is then positioned within the articulator in the same anatomic relation. facebows were developed in conjunction with articulators to relate the maxillary arch to the axis of the condylar hinge in all three planes of space(20). after achieving the hanau face-bow record (fascia bow 132-2sm, teledyne-hanau co., ny, usa), (figure 1), the face-bow assembly was removed and the axis locator rods of the face-bow were placed to contact the outside of the metal posts of the condylar elements on both sides of the hanau h-2 non-arcon articulator (teledynehanau co., ny, usa) with the horizontal condylar guidance screws locked at 30°(21). the upper cast was oriented and luted on the wax bite record of the maxillary arch for mounting (fig.2). the middle groove on the incisal guide pin of the articulator was used as the 3rd point of reference for positioning the upper cast on the articulator(22). figure 1: arbitrary face-bow record. figure 2: mounting the upper cast using the hanau face-bow. j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 29 following that, the lower cast was mounted on the lower member of the articulator according to the cr record. several protrusive bite records were made for each patient then the wax bite was removed from the mouth and trimmed back to the tips of the upper and lower cusps so that the stone cast was clearly visible where it contacted the wax bite (19). all wax records were accepted when it was evident that the patient had protruded straight forward at least 6 mm anterior to centric relation, as shown on the hanau articulator by the condylar spheres having moved anteriorly an equal distance of 6 mm on both sides (23). the condylar inclination on the articulator was adjusted accordingly by releasing the condylar centric locksand the condyle path was altered to varying degrees of steepness until the maxillary cast fitted precisely into the wax bite record with no separation between the stone and the bite, i.e. separation at the distal part of the bite meant that the guidance was too steep, while any anterior separation between the cast and bite record could be a result from too flat condylar guidance (21). after setting the horizontal condylar angles, their centric locks were tightened (figure 3). figure 3: setting the horizontal condylar angle. bennett angle measurement: the lateral condylar angle (bennett angle) for each patient was calculated using the hanau formula: l (lateral adjustment) =h (horizontal adjustment)/8+12 (24) (figs. 4a & b). figure 4a: condylar post setting for estimating bennett angle. figure 4b: condylar post fixed at estimated bennett angle. terminal mandibular hinge axis location: it was performed by using the tmj kinematic face-bow (tmj instrument co. inc, usa).when the axis locator pin of the kinematic face-bow stylus achieved a pure rotational movement during arcing the patient's mandible, the location of the pin point was marked on the flags' graph paper grids on both sides (figure 5). when the axis was located, the flags were removed, styli moved out to mark its tip with graphite pencil and with holding the supported mandible in terminal hinge position; each stylus was moved toward the skin to mark it. the kinematic face-bow assembly was detached from the universal clutch which was taken out of the patient's mouth. the terminal hinge axis point was darkened with a red pen. after that, the interfacial width (ifw) was measured by an electronic caliper (prokit's industries co, ltd, taiwan) (25). figure 5: marking locationof pin point on the flag's graph paper. the face-bow record was transferred to the tmj deluxe model t-7 fully adjustable arcon articulator (tmj instrument co, inc, usa), and the icd of each patient was determined and the condyle posts of the articulator were locked at the determined measurements (18). the maxillary cast of the patient was mounted on the maxillary member of the articulator according to the kinematic face-bow recordthen the mandibular cast was attached to the centric ioc record, placed between the two casts, and j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 30 mounted on the mandibular member of the articulator. verifying the protrusive angle of each patient to figure out the exact fossa analog degree which should be used for fossa molding for that case in order to duplicate that of the patientfor constructing the full mouth rehabilitation prostheses (26), a protrusive ioc record was registered for each patient then two square shaped transparent hard plastic protractors having a scale ranging from (0-60°) were attached to the articulator outside each of its fossa compartments in such a way that the protractor was close to the condylar stylus. the condyle pin was located at the center of the protractor in the terminal hinge position (fig.6). figure 6: the condyle pin located at the protractor center. placing the protrusive ioc record in position between the maxillary and mandibular casts, the angle of eminentia was observed by sighting the center of the condyle pin through the transparent protractor and the protrusive angle of each patient was recorded (figs.7a & b). figure 7 a: estimation of the protrusive angle. figure 7 b: estimation of protrusive angle by sighting the center of the condylar stylus through the protractor. the bennett angle of each condyle was calculated following hanau formula. all angles were tabulated and statisticallyanalyzed with a significance level of p< 0.05. results the descriptive statistics of the mean protrusive angle values showed that the highest was related to the male group recorded by the tmj fully adjustable articulator (35.4°) followed by that scored by the female group (32.4°). the mean protrusive angle value of the male group scored by the hanau h-2 articulator (30.0°) also was higher than the female group (25.6°), (table1). table 1: descriptive statistics of the mean protrusive angle verified by tmj & hanau h-2 articulators (in degrees). type of articulator mean protrusive angle mean s.d. tmj female 32.4 8.180 male 35.4 9.345 hanau h-2 female 25.6 7.947 male 30.0 7.500 total 30.85 8.906 the anova test results of the mean protrusive angle groups verified a highly significant difference between the groups combined, (table 2). table 2: anova test results of the mean protrusive angle groups. mean protrusive angle groups s.o.s df m.s. sig. between groups 1284.750 3 428.250 0.001 within groups 6568.000 96 68.417 total 7852.750 99 the descriptive statistics of the difference of mean values of protrusive angles scored by the tmj articulator and the hanau h-2 articulator for the female patients was higher (6.8°) than for the males (5.4°) as shown in table 3 & fig. 1; a finding that was statistically not significant (table 4). j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 31 table 3: descriptive statistics of the difference of protrusive angle mean values verified by tmj & hanau h-2 articulators (in degrees). tested groups mean protrusive angle, tmj mean protrusive angle, hanau h2 mean diff. of protrusive angle, tmj & hanau h2 s.d. female 32.4 25.6 6.8 3.50 male 35.4 30.0 5.4 4.06 total 30.85 6.1 3.81 figure 1: the mean protrusive angles verified bytmj & hanau h-2 articulators & the mean differences of females & males (in degrees). table 4: anova test results of the difference in protrusive angle means verified by tmj & hanau h-2 articulators. mean difference s.o.s df m.s. sig. between groups 24.5 1 24.500 0.198 ns within groups 690.0 48 14.375 total 714.5 49 concerning the bennett angle, the highest mean (16.42º) which was related to the male group was scored by the tmj articulator, while the lowest one (15.2º) which belonged to the female group was scored by the hanau h-2 articulator (table 5). table 5: descriptive statistics of mean bennett angles of females & males, verified by tmj & hanau h-2 articulators in degrees. groups of mean bennett angle mean s.d min. max. female, tmj 16.05 1.022 14.5 18.25 female, hanau h-2 15.20 0.994 13.88 17.63 male, tmj 16.42 1.167 14.50 18.25 male, hanau h-2 15.75 0.937 13.88 17.00 total 15.85 1.113 13.88 18.25 the anova test results showed a high-ly significant difference (p<0.001) between the groups, (table 6). table 6: anova test results of mean bennett angles. mean s.o.s df m.s. sig. between groups (combined) 20.055 3 6.685 0.001 hs within groups 102.645 96 1.069 total 122.700 99 concerning protrusive angles, the total means of female patients (31.90°) and males (35.40°) verified by the tmj articulator were higher than those scored by the hanau h-2 articulator (26.70° & 30.40°). as a consequence, the total means of protrusive angles verified by the tmj articulator (33.67°) were more than those of the hanau h-2 articulator (28.55°). for the right and left tmjs, group means verified by both articulators were close to each other with the left joint score being more than the right when using the tmj articulator (34.30° vs. 33.04°). also, the left joint group mean was higher than the right joint when using the hanau h-2 articulator (28.70 vs.28.40°), (table 7). comparing the bennett angles of the right and left joints, the means of the female group determined by the tmj articulator were of the same value (16.05°) while in the male group, the left joint angles (16.52°) were more than the right (16.32°) with a difference of 0.2°. means verified j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 32 by the hanau h-2 articulator showed that the angles scored by the females' right joints (15.35°) were more than their left joints (15.02°) with a difference of 0.33°. the opposite occurred with the males where their left joint bennett angles (15.75°) were more than their right joints (15.72°) with a difference of 0.03°.the males' right and left tmjs had bennett angles more than their equivalents of the female patients scored by the two articulator systems (table 8). table 7: descriptive statistics of the detailed group mean values of the female and male patients concerning the right and left joints' protrusive angles. groups (mean) protrusive angle° total mean female tmj r 31.48 31.90 l 32.40 h-2 r 26.80 26.70 l 26.60 male tmj r 34.60 35.40 l 36.20 h-2 r 30.00 30.40 l 30.80 groups mean tmj r 33.04 33.67 l 34.30 groups mean h-2 r 28.40 28.55 l 28.70 table 8: descriptive statistics of the detailed group mean values of the female and male patients concerning the right and left joints' bennett angles. groups (mean) bennett angle° total mean female tmj r 16.05 16.05 l 16.05 h-2 r 15.35 15.19 l 15.02 male tmj r 16.32 16.42 l 16.52 h-2 r 15.72 15.74 l 15.75 groups mean tmj r 16.18 16.23 l 16.28 groups mean h-2 r 15.54 15.46 l 15.39 discussion horizontal condylar (protrusive) angle: the hanau h-2 semi-adjustable non-arcon articulator used in this study revealed that the groups' mean values of left side protrusive angles were equal to (28.70°) which was smaller than that scored by the dentatus arh non-arcon semiadjustable articulator (43.83°) tested in dos santos and ash study (27). also, the right side groups' mean values of protrusive angles of both sexes (28.40º) were smaller than their right side mean angles (44.70°). although the dentatus arh articulator is considered the swedish copy of the hanau h-2 articulator, the differences in these values could be related to the attempt of dos santos and ash to duplicate the jaw movement tracings of the pantograph in the semi-adjustable articulator, a conclusion in which they stressed that their study indicated that a pantographic instrument is too critical to be used to set a semiadjustable articulator. the results of the current study went along with those of el-gheriani and winstanley (28)who reported the presence of great variation in condylar inclinations between the studied patients on one side and between the left and right sides of the same patient. such variation could be explained in that the protrusive and retrusive movements, generated by condylar translation, are influenced by the shape of the eminentia and their maximal range is restricted by the mechanical constraint of the temporomandibular ligaments, namely the stylomandibular ligament and capsule causing the condyles to have limited rotation during protrusion and retrusion(29).this has been clearly explained in that the downward inclination of the articular eminence makes it plausible that the condyle is slightly pressed against the articular eminence during the main translatory protrusive movement and opening movement which are considered of a compressive nature (30). in current study, the hanau h-2 semiadjustable articulator was chosen since the data obtained by this articulator regarding the sagittal condylar inclination using the protrusive ioc record has been compared with that obtained by a jaw-tracking system (31) where the hanau h-2 articulator was recommended for accurate measurements of the sagittal condylar path inclination. in a previous study, taylor et al. (32) repor-ted that the protrusive ioc record was a gene-rally acceptable way for adjusting the horizontal condylar inclination of the hanau h-2 and dentatus semi-adjustable articulators. the use of ioc check bite registrations for programming semiadjustable articulators has been found as an easier alternative to the axiograph (33). since many condylar path recordings have pronounced curvatures, it's doubtful that an articulator can be programmed to reproduce the condylar inclination by assigning fixed values to j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 33 it, thus a custom-fossa insert that could be shaped to follow the curvature of the condylar path would be more accurate (28). as an alternative to the ioc registration methods, average values have been used to set the condylar guidance of articulators in referral to mean inclinations of normal adult eminence morphology (34). as a consequence, setting the condylar inclination at a flatter than average value was advocated to ensure disocclusion of the posterior teeth during excursions (35). how-ever, if the individual inclination of the eminence is very steep or flat, guidance obtained from average value settings may differ sufficiently to cause problems in achieving particular clinical objectives, such as posterior disocclusion or balanced occlusion (12). bennett angle significant and highly significant differ-rences were also present between male and female groups which could generally be related to anatomical variations concerning the shape of condylar heads and fossae curvatures. generally, the males' right and left tmjs had bennett angles more than their equivalents of the female patients scored by the two articulator systems used in this study, a finding which could be due to increased laxity of the temporomandibular ligaments(29) and/or anatomical variations in the inclination of the eminentia(12). the explanation for the differences bet-ween the bennett angle mean values determined by the tmj fully adjustable articulator system with those of the hanau h-2 semi-adjustable articulator system lies in the different techniques utilized in each system starting from locating the arbitrary and terminal hinge axes and deter-mining the protrusive condylar angles on which estimation of the patients' bennett angles were entirely dependent on. it has been reported that the rotating condylar movement affects both the working and the nonworking sides but has its greatest effect on the working side. semiadjustable articulators do not have the ability to compensate for this movement. the fully adjustable articulators can be modulated so that the pathway of the rotating condyle on the articulator can duplicate that of the patient (14). the right and left bennett angle groups' mean values recorded by the hanau h-2 non-arcon semi-adjustable articulator in this study (15.54° & 15.39°) were greater than those recor-ded by the dentatus arh non-arcon-semi-adjustable articulator (12.80° for right side&12.26° for left side) in dos santos and ash study (27), a variation which might be related to their attempt to duplicate the jaw movement tracings of the pantograph in the semi-adjustable articulator. in other words, the condyles usually follow a convex path (curve), on any but the most damaged eminentia, which isn't copied in the slottrack (straight-line) articulators which don't reflect the medial curvature of the non-working horizontal condylar path (36). theusner et al. (29) showed a maximum range of 12.7° for the right joint of their asymptomatic patients while a range of 12.2° maximum existed for the left joint. in their study, the group means of bennett angles of the right joint were significantly larger than those of the left joint. the terminal hinge axis was located with the "sas hinge axis tracing system". on the other hand, the results of thecurrent study indicated that the tmj articulator system, in which a kinematic hinge axis locator was used, has shown that the group means of the female and male bennett angles were close to each other. the left and right joint group means of both sexes were also close to each other (16.28°& 16.18°) but were more than those of theusner et al.(29) study. the difference between the two studies may be due to the different estimation techniques of the bennett angles since theusner et al. applied a" modified sas electronic axiograph" for their different mandibular movement measurements while in this study, the bennett angles were verified by applying the hanau formula in which the actual protrusive condylar angles verified by the axis protractors were incorporated. on the other hand, no statistical differences were located between the bennett angles of the females and males that were verified by the tmj fully adjustable articulator while significant differences were located between the two sexes when using the hanau h-2 semi-adjustable articulator. after comparing the mean values, the bennett angles of both sexes verified by the tmj articulator were statistically significant compared to those verified by the hanau h-2 articulator, a finding that was related to the high precision degree which the axis protractors had provided the tmj articulator with in order to accurately locate the protrusive angles of each patient involved in this study. the results of the current study coincide with that patients acquiring excessive bennett movement and little or no anterior guidance present the greatest challenge in occlusal rehabilitation procedures because the cusp movement pathways of their posterior teeth are very shallow and the elimination of eccentric cusp j bagh college dentistry vol. 28(1), march 2016 a comparison between restorative dentistry 34 interferences can be very difficult. the completely adjustable articulators would be most helpful for these types of patients. as conclusions 1. male protrusive angles were higher than females with the fully adjustable articulator scoring higher mean values than the semiadjustable articulator. 2. non-significant differences existed between the protrusive angles of male and female patients scored by the fully adjustable articulator while significant differences were located using the semi-adjustable articulator. 3. generally, the males' right and left condyles had bennett angles greater than their female equivalents. 4. the highest bennett angle mean values were scored by the male group of the fully adjusttable articulator while the lowest belonged to the female group of the semi-adjustable articulator. 5. a fully adjustable articulator that can provide precision estimation of the horizontal condylar angles and bennett angles would be most helpful in treating full mouth rehabilitation cases. references 1. moslehifard e, nikzad s, geraminpanah, f, mahboub f. full-mouth rehabilitation of a patient with severely worn dentition and uneven occlusal plane: a clinical report. j prosthodont 2012; 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69(2):209-15. 30. naeije m. measurement of condylar motion: a plea for the use of the condylar kinematic centre. j oral rehabil 2003; 30(3):225-30. 31. hangai k. a study on morphological changes in the glenoid fossa by the chew-in method: with reference to effect of the form of central bearing pate. j japan prosthodont soc 2008; 23(2): 239-61. 32. taylor td, huber lr, aquilino sa. analysis of the lteral condylar adjustment of non-arcon semiadjustable articulators. j prosthet dent 1985; 54(1):140-43. 33. boulos pj, adib sm, naltchayan lj. the bennett angle. clinical comparison of different recording methods. ny state dent j, 2008; 74(2):34-8. 34. zarb ga, bolender ci. prosthodontic treatment for edentulous patients: complete denture and implantsupported prostheses. 12th ed. st louis: mosby co., 2004. pp. 294-6. 35. gracis s. clinical considerations and rationale for the use of simplified instrumentation in occlusal rehabilitation. part 2: setting of the articulator and occlusal optimization. int j periodont rest dent 2003; 23:139-45. 36. hobo s. formula for adjusting the horizontal condylar path of the semi-adjustable articulator with intero-cclusal records. part i: correlation between the immediate side shift, the progressive side shift, and the bennett angle. j prosthet dent 1986; 55(4):422-6. j bagh college dentistry vol. 29(3), september 2017 prevalence and oral diagnosis 54 prevalence and localization of the posterior superior alveolar artery in relation to the floor of the maxillary sinus and alveolar crest among sample of iraqis using computed tomography abdullah ahmed ibrahim, b.d.s. (1) lamia h. al nakib, b.d.s, m.sc. (2) abstract background: posterior superior alveolar artery (psaa) is branch of the maxillary artery. it usually supplies the lateral wall of the sinus and overlying membrane. evaluation and awareness of the anatomy of maxillary sinus before surgery is crucial to avoid surgical complications. the aim of this study is to examine the prevalence, location of the (psaa) in relation to the floor of the maxillary sinus and alveolar crest using computerized tomography (ct) scans. materials and methods: this study included 180 iraqi subjects (99 males and 81 females) with age more than 16 years old. ct scans for (right and left) maxillary sinuses were done for each patient. the information obtained was assessed in a coronal multi planar reconstructions images (mprs) in order to obtain the following parameters: prevalence rate of psaa, distance from the lower border of the artery to the: alveolar crest, the floor of the sinus and the medial sinus wall. results: the prevalence of psaa on ct images was 73.61% among total sample. distance from the lower border of the artery to the alveolar crest was (18.42± 4.07) mm, and to the sinus floor was (8.99 ±3.86) mm and to the medial sinus wall was (12.68 ± 2.81) mm. conclusions: ct scan is valuable tool in evaluation and localization of the psaa before maxillary sinus surgery. keywords: psaa, maxillary sinus, maxillary artery, computed tomography. (j bagh coll dentistry 2017; 29(3):54-58) introduction the posterior superior alveolar artery and infraorbital artery (ioa) are branches of the maxillary artery. they supply the lateral wall of the maxillary sinus and the schneiderian membrane (1,2). these arteries should be taken into concern during sinus augmentation procedures because of the possibility of bleeding during the surgery due to injure to the vascular supply of the lateral sinus wall (3). surgical intervention in the maxillary sinus needs a good knowing of its anatomy. the maxillary sinus is the largest sinus of the paranasal sinuses (4). placing dental implants required the presence of enough thickness of the bone. in the posterior maxillary areas, where there is atrophy of the bone and pneumatization of maxillary sinuses which occur as a results of teeth extraction in this area. as any other surgical intervention, a large number of complications whether it was intraoperative or postoperative may occur during the surgery of sinus floor elevation. one common complication is the blood vessel trauma (5,6). (1)master student. department of oral diagnosis, college of dentistry, university of baghdad (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. computerized tomography (ct) is a digital imaging tool that allows the quantification and differentiation of hard and soft tissues. ct can examine the arteries, anatomical structures, is also can calculate bone dimension, identify specific anatomical landmarks and detect sinus pathologies (7). hence, this study was undertaken in order to show variations in the vascular morphology of the posterior superior alveolar artery in a sample of iraqi subjects using ct scans. materials and methods the sample the sample in this study composed of 180 iraqi patients (99 males and 81 females) with an age not less than 16 years old. they attended the radiology department at neuro science hospital in baghdad to take spiral ct scan of the brain and paranasal sinuses from november 2015 till february 2016. all participants were informed well about the aim and the method of the study and asked them if they agree to participate and they were free to withdrawal at any time they decide. a special consent form was to be signed by each one. the patients were divided according to dental status into dentate partially edentulous patients and then ct scans for (right and left) maxillary sinuses were taken for each patient using siemens somatom definition as (germany). the parameters of the acquisition were 1 mm thickness slice, kv=120, mas=370 and exposure time was 20 seconds. the patients were j bagh college dentistry vol. 29(3), september 2017 prevalence and oral diagnosis 55 positioned in supine on the ct examination table with the head on the head rest. the information obtained was the measurements parameters which were done using the calibration function of the syngo software program on syngo acquisition workplace in coronal multi planar reconstructions (mprs), axial and coronal images were evaluated to reconfirm that the examined area contain artery canal. these ct scan images were used to identify the psaa in order to obtain the following parameters: 1. prevalence rate of the psaa (figure 1). 2. distance from the lower border of the artery to the alveolar crest (the vertical line from the artery to the crest) (8) (figure 2). 3. distance from the lower border of the artery to the sinus floor (the vertical line from the artery to the floor) (figure 3). 4. distance from the lower border of the artery to the medial sinus wall (9) (figure 4). statistical analyses data were analyzed using spss (statistical package of social science) software version 19. in this study the following statistics were used: 1. descriptive statistics: including means, standard deviations, frequency (no.), percentages, and statistical tables and figures. 2. inferential statistics: including: independent sample t-test: to verify the gender difference for the measured variables. figure 1: coronal sections shows the psaa canal figure 2: coronal sections shows distance between lower border of the posterior superior alveolar artery to the alveolar crest figure 3: coronal sections shows distance between lower border of the posterior superior alveolar artery to the floor of the sinus figure 4: coronal sections shows distance between lower borders of the posterior superior alveolar artery to the medial sinus wall j bagh college dentistry vol. 29(3), september 2017 prevalence and oral diagnosis 56 results radiographical prevalence rate of the posterior superior alveolar artery (psaa) on ct images the radiographical prevalence rate of psaa was 73.61% among total sample and it was 82.32% in males and was 62.96% in females (figure 5). figure 5: radiographic prevalence of psaa in relation to the gender. (a) for females, (b) for males and (c) for total sample. psaa measurement parameters (table 1) 1. the mean distance from the lower border of the artery to the alveolar crest was 18.42± 4.07 mm for the total sample in which it was 18.18 ± 3.70 mm in females and 18.57± 4.29 in males. statistically there no significant correlation between genders and this distance since the p-value=0.447. 2. the mean distance from the lower border of the artery to the sinus floor was 8.99 ± 3.86 mm for the total sample in which it was 8.41 ± 3.16 mm in females and 9.35 ± 4.21inmales. statistically there no significant correlation between genders and this distance since the p-value=0.053. 3. the mean distance from the lower border of the artery to the medial sinus wall was 12.68 ± 2.81 mm for the total sample in which it was 13.10 ± 2.61 mm in females and 12.41 ± 2.90inmales. statistically there no significant correlation between genders and this distance since the p-value=0.053. table 1: descriptive statistics and genders difference of psaa measurement parameters distance from the artery genders descriptive statistics genders difference (d.f.=263) n mean s.d. t-test p-value to the alveolar crest total 265 18.42 4.07 -0.762 0.447 (ns) females 102 18.18 3.70 males 163 18.57 4.29 to the sinus floor total 265 8.99 3.86 -1.944 0.053 (ns) females 102 8.41 3.16 males 163 9.35 4.21 to the medial sinus wall total 265 12.68 2.81 1.944 0.053 (ns) females 102 13.10 2.61 males 163 12.41 2.90 j bagh college dentistry vol. 29(3), september 2017 prevalence and oral diagnosis 57 discussion the importance of considering the vascular system of the maxillary sinus when employing sinus surgery, particularly lateral approach sinus floor augmentation relates to potential intraoperative complications (1,2,10). sinus augmentation is a method with high predictability for placing successful dental implants into atrophic posterior maxilla (11,12). blood vessels distribution in this area changes when the alveolar bone is severely atrophied because of increased age and loss of dentition. moreover, the number and diameter of the blood vessels may decrease in elderly edentulous patients (13), so knowledge of the anatomic structure of the area is important for this procedure. the prevalence of the psaa from the examined sinuses using mpr-ct images was found to be 73.6% for the total sample. the success rate for identifying the artery was slightly higher than that reported by fontana et al. (14) for african-americans (72.2%) and in the caucasians (43.2%). guncu et al. (7) reported a prevalence of 64.5%, elian et al. (8) 52.9%, mardinger et al. (9) 55% and kim et al., (13) 52%. this variation may be related to the methods the other groups used to detect and describe the artery. psaa measurements parameters in the present study, comparison between right and left sides in the same patient was not done but only gender difference was performed due to the anatomical difference in addition to the dental condition on both sides that were not always the same. distance from the lower border of the artery to the alveolar crest the mean distance from the lower border of the artery to the alveolar crest and it was 18.57 ± 4.29 mm for males and 18.18 ± 3.70 mm for females and for the total sample it was 18.42 ± 4.07 mm. this finding is close to that of guncu et al. (7) and kim et al. (13) and higher than elian et al. (8) (16.4 mm) and mardinger et al. (9) (16.9 mm). distance from the lower border of the artery to the sinus floor the second measurement was the mean distance from the lower border of the artery to the sinus floor which was 8.99 ±3.86 mm for the total sample (9.35 ± 4.21 mm in males and 8.41± 3.16 mm in females). this distance was reported by guncu et al. (7) as 7.8 ± 0.3 mm and by mardinger et al. (8) as 7–8 mm. distance from the lower border of the artery to the medial sinus wall the third measurement was the mean distance from the lower border of the artery to the medial sinus wall which was 12.68 ± 2.81 mm for the total sample (12.41± 2.90 mm in males and 13.10± 2.61 mm in females). it is near to that reported by guncu et al. (7) which was 11 ± 3.8 mm. references 1. solar p, geyerhofer u, traxler h, windisch a, ulm c, watzek g. blood supply to the maxillary sinus relevant to sinus floor elevation procedures. clin oral implants res 1999; 10: 34-44. 2. traxler, h., windisch, a., geyerhofer, u., surd, r., solar, p. and firbas, w. arterial blood supply of the maxillary sinus. clin anat 1999; 12, 417-21. 3. ella, b., sedarat, c., noble rda, c., normand, e., lauverjat, y., siberchicot, f., caix, p. and zwetyenga, n. vascular connections of the lateral wall of the sinus:surgical effect in sinus augmentation. int j oral maxillofac implants 2008; 23, 1047-52. 4. park, w.-h., choi, s.-y. and kim, c.-s. study on the position of the posterior superior alveolar artery in relation to the performance of the maxillary sinus bone graft procedure in a korean population. j korean assoc oral maxillofac surg 2012; 38, 71-77. 5. flanagan, d. arterial supply of maxillary sinus and potential for bleeding complication during lateral approach sinus elevation. implant dent 2005;14, 3368. 6. testori, t., rosano, g., taschieri, s. and del fabbro, m. ligation of an unusually large vessel during maxillary sinus floor augmentation. a case report. eur j oral implantol 2010;3, 255-8. 7. guncu, g. n., yildirim, y. d., wang, h. l. and tozum, t. f. location of posterior superior alveolar artery and evaluation of maxillary sinus anatomy with computerized tomography: a clinical study. clin oral implants res 2011; 22, 1164-7. 8. elian, n., wallace, s., cho, s. c., jalbout, z. n. and froum, s. distribution of the maxillary artery as it relates to sinus floor augmentation. int j oral maxillofac implants 2005; 20, 784-7. 9. mardinger, o., abba, m., hirshberg, a. and schwartz-arad, d.prevalence, diameter and course of the maxillary intraosseous vascular canal with relation to sinus augmentation procedure: a radiographic study. int j oral maxillofac surg 2007; 36, 735-8. 10. rosano, g., taschieri, s., gaudy, j. f., weinstein, t. and del fabbro, m. maxillary sinus vascular anatomy and its relation to sinus lift surgery. clin oral implants res 2011; 22, 711-5. 11. wallace, s. s. and froum, s. j. effect of maxillary sinus augmentation on the survival of endosseous dental implants. a systematic review. ann periodontol 2003; 8, 328-43. j bagh college dentistry vol. 29(3), september 2017 prevalence and oral diagnosis 58 12. pjetursson, b. e., tan, w. c., zwahlen, m. and lang, n. p. a systematic review of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation. j clin periodontol 2008; 35, 216-40. 13. kim, j. h., ryu, j. s., kim, k. d., hwang, s. h. and moon, h. s. a radiographic study of the posterior superior alveolar artery. implant dent 2001; 20, 306310. 14. fontana, iii, john battista; reynolds, mark a.maxillary sinus morphology: a radiographic retrospective evaluation of the posterior superior alveolar artery in caucasian and african-american subjects. (master’s thesis, university of maryland, baltimore. biomedical sciences-dental school), 2012. الخالصة السنــــــــــــــــــــــــيي الشـــــريــــــــــا . الجراحية المضاعفات لتجنب ضرورية الجيب رفع قبل الفـــــكي الجيب تشريح وتقيـــــيم معرفة :المقدمة .المغطي والغشاء الوحشي الجيب جدار يغذي الذي ـلويالع ـكيالف الشــريا فروع من فرع هو ـلفيالي ـلويلعا الفــــــكي والعمـم ـبقــــــــــتب رضرضـية الجيــوعال ـلفيــريـــا السنـــيي العـــلوي اليـالشـــهو معرفـة احتماليـة وجـو و موقـع الهدف من الدراسة: ـــية.السنـيي راستيدام التصــويرراألشــــــــعة المقطع تـم و عاما، 01 من أكثر اعمارهم كانت الذين( اإلناث من 80 و الذكور من 99) فر ا( 081) الدراسة هذه شملت :المستيدمة الموا و البحث طرق الفكـي للجيـب المقطعيـة األشـعة اجـراء تـم.5101 شـباط إلـ 5102 الثـاني تشـرين مـن للفتـر رغـدا فـي العصـبية العلـوم مستشـف فـي الدراسة اجراء علـ الحصـو اجـل مـن المسـتويات متعـد مركبـة صـور رواسـطة تقييمـــــها تـم عليهـا الحصـو تـم التـي المعلومـات. مـري لكل( واليسار اليمين) السـنيي الشـريا مـن السـفلي الحـد مـن المسـافةو اليــــــــــــــلفي العـــــــــــــلوي السنـــــــــــيي الشــــــــــريا وجو احتمالية معد :ا ناه القياسات . الفكي للجيب الجدارالوسطي إل و الفكي الجيب ارضية إل و السنيية العمم قمة إل اليــــلفي العـلوي وكانـت ،(٪60.1) هـو الدراسـة ضـمن االفـرا لكـل فكـي جيـب 011 فحـ عند اليلفي العلوي السنيي الشريا وجو احتمالية معد وكا :النتائج الجيـب ارضـية إلـ و ملـم( 8.16± 08.85) السنيية العمم قمة إل الشريا من السفلي الحد من المسافة وكانت.اإلناث من الذكور عند أعل النسبة . ملم( 5.80± 05.18) الفكي للجيب الوسطي الجدار إل و ملم( 0.81± 8.99) الفكي جراحــة قبـل اليلفـي العلـوي السـنيي الشـريا موقـع وتحديـد ايجـا فــي قيمـة أ ا هـو المقطعيـة عةراالشـ التصـوير أ إلـ الدراسـة تشـير:االسـتنتاجات .العلوية األنفية الجيوب https://archive.hshsl.umaryland.edu/browse?type=author&value=fontana%2c+iii%2c+john+battista https://archive.hshsl.umaryland.edu/browse?type=author&value=reynolds%2c+mark+a. https://archive.hshsl.umaryland.edu/browse?type=author&value=reynolds%2c+mark+a. alan.docx j bagh college dentistry vol. 28(1), march 2016 an in vitro basic sciences 174 an in vitro evaluation of the effectiveness of gotu kola (centella asiatica) on inhibiting the growth of selected microorganisms in human saliva alan n. talabani, b.d.s., m.sc. (1) abstract background: gotu kola (centella asiatica) has been used as a traditional medicine for many years to cure different kinds of diseases. studies have been reported that gotu kola extracts might be used as a cure for oral diseases such as periodontal disease. in the present study, gotu kola leaves extracted with water will be used to evaluate its effect on some microorganisms living in the human saliva using minimum inhibitory concentration (mic) method. material and method:gotu kola fresh leaves extract have been used with water as a solvent, a rotary evaporator was used to separate the solvent from the extract. the following microorganisms: streptococci, lactobacilli, and staphylococcus aureus have been isolated fromthe saliva of ten volunteers participated in the present study. nutrient broth tubes have been prepared for mic test, where various concentrations of the gotu kola extracts (0.5mg/ml, 1 mg/ml, 2 mg/ml, 3 mg/ml, 4 mg/ml, and 5 mg/ml) were added, respectively. the tubes incubated at 370c for 48h. results:the mic test shows that a concentration of 4 mg/ml have the ability to inhibit the growth of oral lactobacilli and 8 mg/ml has the ability to inhibit the growth of s. aureuswhich may be due to asiaticoside and asiatic acid which are active ingredients that the leaves extracts consists of. there was no mic for streptococci. conclusion:the gotu kola leaves extract can be used to inhibit the growth of some oral microorganisms at certain concentration. keywords:centella asiatica, oral microorganisms, antimicrobial activity, minimum inhibitory concentration. (j bagh coll dentistry 2016; 28(1):174-178). introduction gotu kola which is also known in malaysia as (pegaga) is one of the most well-known herbs in the world that have been used as a folk medicine, especially in south east asia. the plant is a slender-stemmed delicate perennial creeping herb, belonging to the umbelliferae family. originally, the plant was identified botanically as hydrocotyle asiatica linn, but subsequently, it was named centella asiatica (1). gotu kola, c. asiatica is also known as (vallarai in india, di chien tsao in china and navelwort in europe). all are believed to have the same active compounds and possibly good antimicrobial activity to inhibit the growth of some microorganisms that are believed to be etiologic microorganisms in oral diseases (1-4). many microorganisms including staphylococcus species, streptococcus species, and lactobacillus species are found in human saliva (5). dental caries has been known to be caused by acidogenic and aciduric bacteria, such as mutans streptococci and lactobacilli (6,7). these bacteria are involved in the fermentation of dietary carbohydrates producing organic acids that are responsible for decalcification and decay of teeth (8,9). as the main reservoir for s. aureus are the nares, it is reasonable that the organism will occasionally be present in saliva and on the oral mucosa which cause the infection (10). (1)lecturer, department of microbiology and immunology, school of medical sciences, faculty of medicine, university of sulaimaniayah this gives a great motive for the researchers to evaluate the effect of gotu kola extracts on these microorganisms. several methods have been used for preparation of medicinal plants extract such as maceration, infusion, digestion, decoction, and percolation. the extraction process of medicinal plant extracts including freeze drying and rotary evaporator. different solvents have been used for extraction of medicinal plants including 95% ethanol and n-hexane (11,12), according to dashet al.(12), water can be used as another solvent for extraction process. in the present study, an experiment will be performed to see how effective is the gotu kola fresh leaves extracted with water as a solvent on some isolated microorganisms in human saliva using minimum inhibitory concentration (mic). materials and methods gotu kola source gotu kola fresh plants which is also known as (pucuk pegaga) in local malaysian markets were obtained. the plants were washed with distilled water and sterile scissor was used to cut the leaves from the stem to cut into pieces (figure. 1). j bagh college dentistry vol. 28(1), march 2016 an in vitro basic sciences 175 figure 1. centella asiatica fresh leave extraction method the extraction method of gotu kola was performed by using water as solvent; the procedure followed dash with some modifications(12). the gotu kola fresh contained 262.41 g of leaves were weighed using electronic balance (monobole inside, weighting technology, pb 3002-s), then were chopped and placed inside a blender (fiamma sdn bhd, ebm-9182fg, kuala lumpur, malaysia) with 300 ml distilled water for 2-3 minutes. the blended leaves were then poured in a sterile flask inside the reflux ® (copnes scientific sdn bhd, selangor, malaysia). the reflux consists of an allihn condenser (cone 24/29, 250 mm effective length, copnes scientific sdn bhd, selangor, malaysia) and a conical flask (1000 ml, socket 24/29, copens scientific sdn bhd, selangor, malaysia). an anti-bumping granule (bdh prolabo ® (batch no. 08a110018, uk) was added to the flask to prevent the liquid from being bumped during the boiling process (figure. 2). figure 2. the design of the reflux containing the gotu kola fresh leaves the fresh leaves were boiled under reflux for one hour. after the boiling process, the flask containing the extract solution is kept for 20 minutes to cool at room temperature. then the solution was filtered using a sterile handkerchief, folded, and squeezed to obtain a red colored solution (figure. 3). figure 3. filtered gotu kola extracts solution the filtered extract solution was placed in the rotary evaporator (heidolph, laborota 4011digital) for 3-4 h which was run at 870c, 150c vacuum cooler, 300 mbar and 62 rpm to remove water solvent from the extract (figure 4). figure 4. rotary evaporator containing the extract solution after the evaporation process, the concentrated extract was poured in a crucible and placed in a drying oven for 24h at 1050c. the dried gotu kola was first broken into smaller pieces by using a pair of sterile forceps then it was ground by a mortar and pestle to obtain the fine powder. the gotu kola powder is put in a sterile glass petri dish and placed in a drying oven overnight at 1050c to remove all the moistures from the powder. then, the glass petri dish placed in desiccators to cool for 1 hour. then, the powder is stored in small container for use (figure 5). j bagh college dentistry vol. 28(1), march 2016 an in vitro basic sciences 176 figure 5. gotu kola fine powder in a sterile container media preparation for mic mixing 8g of nutrient broth from merk ® (cat no. 1.0543.0500, darmstadt, germany) with 1l of distilled water. the media poured into six test tubes and autoclaved at 1210c for 15 min.mouthwash containing chlorhexidine 0.12% w/v (oradex, malaysia) was used as positive control and deionized water was used as negative control. then, the tubes were stored in the fridge for use.38g of mueller hinton agar (sigma aldrich, malaysia) mixed with 1l of distilled water. the media was autoclaved at 1210c for 15 min, the media poured into the plates and kept in the fridge. saliva samples fresh saliva samples from 10 clinically healthy volunteers without any obvious signs and symptoms of systemic and oral diseases were collected in the morning. the volunteers were university students aged (18-24) and previously informed not to wash their mouth for 24 hours. bacterial culture three types of bacteria species were isolated from the saliva of the volunteers: streptococci, lactobacilli, and staphylococcus aureus. mitis salivary agar sigma aldrich, malaysia was used to culture oral streptococci. rogosa agar (himedia labs. india) was used to culture oral lactobacilli. blood agar (himedia labs., india) was used to culture s. aureus. both streptococci and s. aureus were incubated aerobically at 370c for 24h while lactobacilli were incubated anaerobically at the same temperature. the isolated microorganisms were subcultured on mueller hinton agar and inoculated into nutrient broth as stock cultures for use. the cultures were identified on the basis of gram staining characters and biochemical tests. the method of minimum inhibitory concentration (mic) extracting 0.5g (500mg) of gotu kola leaves powder dissolved in 5 ml distilled water in a small beaker to get a concentration of 100 mg/ml.a series of different concentrations (10 mg/ml, 8mg/ml, 4 mg/ml, 2mg/ml, 1 mg/ml, and 0.5 mg/ml) have been added aseptically into the broth tubes, respectively. the microbial inoculum was standardized at 0.5 mcfarland. 0.1 ml of the broth containing the isolated microorganisms from the saliva had been added to each one of the eight tubes including positive and negative controls, respectively. the tubes were then incubated at 370c for 24h. 0.1 ml from each tube have been added to mueller hinton agar plates to assist the mic results and incubated at 370c for 48h. the procedure was done in triplicate. results the results showed that none of the concentrations inhibit the growth of oral streptococci (table 1). a concentration of 4 mg/ml showed antimicrobial activity towards oral lactobacilli except for 3 out of 10 (30%) volunteers (table 2). a concentration of 8 mg/ml showed antimicrobial activity towards s. aureuswhich can be consider to be mic (table 3). table 1. test performance for minimum inhibitory concentration (mic) on oral streptococci no. of volunteers 10 mg/ml 8 mg/ml 4 mg/ml 2 mg/ml 1 mg/ml 0.5 mg/ml + ve chl0.12% -ve dw 1 + + + + + + + 2 + + + + + + + 3 + + + + + + + 4 + + + + + + + 5 + + + + + + + 6 + + + + + + + 7 + + + + + + + 8 + + + + + + + 9 + + + + + + + 10 + + + + + + + +: microbial growth, -: no microbial growth j bagh college dentistry vol. 28(1), march 2016 an in vitro basic sciences 177 table 2. test performance for minimum inhibitory concentration (mic) on oral lactobacilli no. of volunteers 10 mg/ml 8 mg/ml 4 mg/ml 2 mg/ml 1 mg/ml 0.5 mg/ml + ve chl 0.12% -ve dw 1 + + + + 2 + + + + 3 + + + + 4 + + + + 5 + + + + 6 + + + + + 7 + + + + 8 + + + + 9 + + + + + 10 + + + + + +: microbial growth, -: no microbial growth table 3. test performance for minimum inhibitory concentration (mic) s. aureus no. of volunteers 10 mg/ml 8 mg/ml 4 mg/ml 2 mg/ml 1 mg/ml 0.5 mg/ml + ve chl 0.12% -ve dw 1 + + + + + 2 + + + + + 3 + + + + + 4 + + + + + 5 + + + + + 6 + + + + + 7 + + + + + 8 + + + + + 9 + + + + + 10 + + + + + +: microbial growth, -: no microbial growth discussion methanol and ethanol were used previously to obtain extracts from centella asiatica while in the present study water was usedto obtain plant extracts. few factors contribute in influencing the rate of extraction and quality of extracted bioactive phenolic compounds, including type of extraction method, particle size of medicinal plants, type of solvent, temperature and extraction time (13,14). the results showed that c. asiatica has no antimicrobial activity on oral streptococci which is compatible with other studies (15) and incompatible with others (16) which it might due to the type of extraction method and the antimicrobial susceptibility test they used. antimicrobial activity of c. asiatica towards oral lactobacilli appeared at 4 mg/ml which is relevant to previous studies on the same microorganism (16). the results also showed positive antimicrobial activities towardss. aurues at 8 mg/ml, the results similar to previous studies(11,17-19). it was reported that gotu kola leaves are rich in asiaticoside and asiatic acid which are considered as the active ingredients in the herb itself that proves its efficacy towards microorganisms such as s. aureus, e. coli, s. pneumonia, and h. pylori(11,13,14). analytical methods such as tlc and hplc are needed for further confirmation. as a conclusion, the gotu kola leaves extract using water as solvent with mic of4 mg/ml and8 mg/ml can inhibit the growth oforal lactobacilli and s. aureus, respectively. the crude extract couldn’t inhibit the growth of oral streptococci. further in vitro studies evaluating the effectiveness of c. asiatica on different types of oral microorganisms are recommended to accomplish this study. references 1. babu td, kuttan g, padikkala j. cytotoxic & antitumor properties of certain taxa of umbelliferae with special reference to centella asiatica (l.) urban. ethnopharmacol 1995; 48(1): 53-7. 2. sastravaha g, gassmann g, sangtherapitikul p, grimm wd. adjunctive periodontal treatment with centella asiatica and punica granatum extracts in supportive periodontal therapy. journal international academic periodontol2005; 7: 70-9. 3. ali j, pramod k, shahid h. herbal remedies for the treatment of periodontal disease – a patent review. recent patents on drug delivery & formulation. 2009; 3: 221-228. 4. cravotto g, boffa l, genzini l, garella d. phytotherapeutics: an evaluation of the potential of j bagh college dentistry vol. 28(1), march 2016 an in vitro basic sciences 178 1000 plants. j clinical pharmacy and therapeutics. 2010; 35: 11–48. 5. philip k, teoh wy, muniandy s, yaakob h. identification of major cultivable aerobic bacteria in the oral cavity of malaysian subjects americans. j biochemistry and biotechnology 2008; 4(4): 367-70. 6. brooks gf, carroll kc, butel js, morse sa, mietzner ta. jawetz, melnick and adelber's medical microbiology. michael weitz and harriet lebowitz, editors. 25th ed. new york: mcgraw hill; 2010. 7. palombo ea. traditional medicinal plant extracts and natural products with activity against oral bacteria: potential application in the prevention and treatment of oral diseases. medicinal plants and oral health. 2009:1-15. 8. van houte j. role of micro-organisms in caries etiology. j dent res 1994; 73: 672. 9. jebashree sh, jayasurya sk, emmanuel ss, devapriya d. antimicrobial activity of few medicinal plants against clinically isolated human cariogenic pathogens—an in vitro study. international scholarly research network. 2011 10. dahlen g. bacterial infections of the oral mucosa. periodontol 2009; 49:13–38. 11. duangkamol t, theera r, thavajchai s, nongluck r. a study on antibacterial activity of crude extracts of asiatic pennywort and water pennywort against staphylococcus aureus. kmitl science journal. 2008; 8(2). 12. dash bk, faruquee hm, biswas sk, alam mk, sisir sm, prodhan uk. antibacterial and antifungal activities of several extracts of centella asiatica l. against some human pathogenic microbes. lsmr. 2011; 35. 13. zainol na, voo, sc, sarmidi mr, aziz ra. profiling of centella asiatica (l.) urban extract. the malaysian j analytical sci 2008; 12(2): 322-327. 14. norzaharaini mg, wan norshazwani ws, hamsah a, nor izani nj, rapeah s. a preliminary study on the antimicrobial activities of asiaticoside and asiatic acid against selected gram positive and gram negative bacteria. health and the environment j 2011; 2(1). 15. vadlapudi v, behara m, kaladhar d, kumar s, seshagiri b, paul j. antimicrobial profile of crude extracts calotropis procera and centella asiatica againstsome important pathogens. indian j sci technol 2012; 5(8): 0974-6846. 16. gauniyal p, teotia us. antimicrobial activity of sixteen medicinal plants against oral flora and its efficacy comparison with 2% chlorhexidine. international j multidisciplinary and scientific emerging res 2015; 4(2): 2349-6037. 17. panthi mp, chaudhary rp. antibacterial activity of some selected folklore medicinal plants from west nepal. scientific world 2006; 4(4). 18. areekul v, jiapiyasakul p, chandrapatya a. in vitro antimicrobial screening of selected traditional thai plants. thai j agricultural science. 2009; 42(2): 81-9. 19. jagtap ns, khadabadi ss, ghorpade ds, banarase nb, naphade ss. antimicrobial and antifungal activity of centella asiatica (l.)urban, umbeliferae. research j pharm tech2009; 2(2). athraa f.doc j bagh college dentistry vol. 25(2), june 2013 immunohistochemical study oral diagnosis 47 immunohistochemical study of cd34 in tooth eruption by using amniotic stem cells lubna k. jassim, b.d.s., m.sc. (1) athraa y. alhijazi, b.d.s., m.sc., ph.d. (2) abstract background: tooth eruption is a more general process, however, which includes certain posteruptive tooth movements. there are two fundamental requirements for both tooth eruption to occur: (1) require soft tissue, intervening between tooth structure and alveolar bone, which plays an important role in regulating the remodeling of adjacent tissues. (2) require bone turnover that is temporally and spatially regulated to facilitate specific translocations of teeth through alveolar bone these amniotic stem cells are multipotent and able to differentiate into various tissues, which may be useful for human application and recently it used in many medical branches. cd34 is an endothelial marker that is extensively used in immunohistochemistry and most vascular endothelial cells. expression of the stem cell antigen cd34 is a defining hallmark of hemopoietic stem cells and progenitors. this study aimed to study the expression of cd34 by dental cells involved in tooth eruption after administration of amniotic stem cell materials and methods: forty eight albino swiss mice of one day old age injected with isolated amniotic stem cells in the anterior region of maxilla (incisors area) other 16 mice injected with saline represents control. sacrifice 4 mice for each period (4, 7, 10, and 13) day old age. the result were studied histologically and immunohistochemistry. results: immunohistochemical result revealed positive expression of cd34 in pulp (vascular, paravascular), mesenchymal cell and in the dental sac of different groups. coincidence test of expression marker cd34 in various studied group shows that chorion application affected on cd34 expression in pulp while amniotic fluid affected on dental sac. conclusion immunohistochemical study of expression marker cd34 in various studied groups show that chorion application affected on cd34 in pulp .while amniotic fluid affected on dental follicle. key words: amniotic stem cells, tooth eruption. (j bagh coll dentistry 2013; 25(2):47-53). introduction stem cells are reprogrammed cells which were able to develop into many different types of functioning cells, including liver, bone and nerve cells. amniotic fluid stem cells are intermediate between embryonic stem cells and adult stem cells. all over the world, universities and research institutes are studying amniotic fluid to discover all the qualities of amniotic stem cells. amniotic fluid is a good source of stem cells. the advantages of generating pluripotent cells without any genetic manipulation makes them more likely to be used for therapy.tooth eruption is a localized process in the jaws which exhibits precise timing and bilateral symmetry. develop within the jaws and their eruption is a complex infancy process during which they move through bone to their functional positions within the oral cavity (3) . cd34 is a 90to 120-kda cell surface sialomucin that is widely used for the enrichment of human hematopoietic stem cells (hscs) because of its selective expression on progenitor cells and absence on mature hematopoietic cells. (1)msc student, department of oral diagnosis, college of dentistry, university of baghdad. (2)professor. department of oral diagnosis, college of dentistry, university of baghdad. cd34 molecule is a cluster of differentiation molecule present on certain cells within the human body. it is a cell surface glycoprotein and functions as a cellcell adhesion factor. it may also mediate the attachment of stem cells to bone marrow extracellular matrix or directly to stromal cells. cd34 marker is the commonly used marker of hematopoietic progenitor cells and endothelium (4). materials and methods seventy nine albino swiss female mice were used in the present study. those mice were divided into 3 main groups: 1. experimental group: consisted of 16 mice of one day old of age injected with isolated amniotic stem cells in the anterior region of maxilla (incisors area). sacrifice 4 mice for each period (4, 7, 10, and 13) day old age. those 16 mice injected with amnionic cells, 4mice for each scarifying periods. 2. control group: consists of 16 mice of one day old age, injected with normal saline in the anterior incisors region of maxilla. sacrifice 4 mice for each period (4, 7, 10, and 13) day. 3. pregnant mice group: consists of 15 pregnant mice: 5 out of 15 were used to collect their j bagh college dentistry vol. 25(2), june 2013 immunohistochemical study oral diagnosis 48 autologous amniotic fluid at (13 day of gestation period), and stored to be used to their neonatal embryo. while other 10 pregnant mice were scarified to obtain amnionic and chorionic cells from their placenta at (17 day of gestation period). collection of amniotic fluid amniotic fluid was collected from each 5 pregnant mice at 13 day of gestation period ( separately) , by using needle aspiration technique , cleaned their skin and wiped with alcohol, then aspirate the fluid using insulin syringe and preserved the amniotic fluid in sterile tube at 80°c until it used. isolation amniotic stem cells from the placenta samples were obtained from 10 pregnant mice at 17 day gestation period to isolate chorion and amnion, after sacrifice the pregnant mice by over dose anesthesia, the embryos inside amniotic membrane with their placenta will excluded immediately. then isolate the embryo from the placenta, and carrying the following procedures: 1. the placenta was cleaned from blood clot with a sterile phosphate-buffered saline solution. 2. removing of amniotic membrane from embryos and put in flask. 3. take a pair of sterile scissors and carefully cut the outside epithelial layer off. the more cut the more stem cells get. the amnion layer is mechanically peeled off the chorion. 4. washing the amnion in phosphate buffered saline solution (pbs) in several times (8-10x) to remove blood. 5. mince the tissue thoroughly with a pair of another sterile scissors. 6. to release amniotic epithelial cells, incubate the minced amnion membrane with trypsin (0.05%) for 10 minutes at 37°c. 7. treating the remaining tissue in another tube of trypsin (0.05%) for 20 minutes at 37 °. 8. pooling the cells from the digests. 9. fuge the filtered cell suspension for 8 minutes at 1200 rpm. 10. washing the cell pellet with pbs and fuge again. 11. counting the cells with a hemocytometer and it is advisable to determine the viability of the cells by exclusion of trypan blue dye, 12. resuspending the pellet in freezing medium by pipetting gently. 13. in order to freeze the cells gradually and safe, place the ampoules in -60°c or less and leave them there for 16-24 hours(5). (all operation was done under sterile condition, using a laminar flow hood. monoclonal antibodies cd34 and their detection kit. anti-cd34 antibody [mec 14.7] hematopoietic stem cell marker (ab8158) monoclonal (rat anti -mouse), isotype (igg2a), applied dilution 1:50, store at -20ºc. abcam anti mouse hrp/ dab immunohistochemistry detection kit, (catalog no. ab64259) was used. results histological and immunohistological tests for detection the expression of cd34 marker were performed on both experimental and control groups for all periods. 1. at 4 days old mouse in control group, dental sac only shows positive expression of cd34 in tooth of mouse 4 days old seen in figure (1). in experimental group ( amnion) :pulp tissue of tooth in mouse 4 days old treated with shows positive e expression of cd34 in paravascular area. figure (2) with chorion: positive cd34expression of vascular cell and mesenchymal cell figure (3). while tooth of mouse treated with amniotic fluid shows the expression of cd34 marker in mesenchymal cell and paravascular cell in the pulp. and in the area of new bone formation around the tooth view the cd34expression in stromal cell. figures (4&5) figure 1: positive cd34 demonstrated in dental sac (arrow) area of tooth germ of mouse 4 days old (control). dab stain with j bagh college dentistry vol. 25(2), june 2013 immunohistochemical study oral diagnosis 49 2at 7 days old mouse figure (6) shows the endothelial cell of blood vessels with positive cd34expression in control group. while section in pulp of tooth mouse treated with chorion illustrates expression of cd34 obviously in the endothelial cell (vascular cell, mesenchymal cell, and paravascular cell) in figures (7, and 8). with amnion see the expression in pulp and dental sac as seen in figure (9). figure 2: cd34 positive (arrow) paravascular location in pulp tissue of mouse 4 days old treated with amnion, dab stain with counter stain hematoxylin x400 figure 3: cd34 positive expression by vascular cell (arrow) and even in mesenchymal cell (mc) in pulp of mouse 4 days old treated with chorion. dab stain with counter stain hematoxylin. x 400 figure 4: positive cd34 expression by paravascular cell (arrow) and in mesenchymal cell (mc) in pulp of mouse 4 days old treated with amniotic fluid. dab stain with counter stain hematoxylin. x400 figure 5: positive cd34 demonstrated in stromal cell (arrow) of new bone formation around teeth of mouse 4 days old treated with amniotic fluid. h&e x400 j bagh college dentistry vol. 25(2), june 2013 immunohistochemical study oral diagnosis 50 3at 10 days old mouse: (fig.10) shows obviously positive cd34 expression in dental sac and pulp (vascular and paravascular) in control group. with amnion, view expression of cd34 in root formation portion (fig.11). with chorion illustrates expression of cd34 in pulp and dental sac area include periodontal ligament and stromal cell of newly formed bone (fig.12). with amniotic fluid cd34 express in numerous blood vessels in pulp and dental sac area, as seen in (fig.13). figure 7: positive cd34 expressed on endothelial cell, mesenchymal cell in pulp of mouse 7 days old treated with chorion. dab stain with counter stain hematoxylin .x200 figure 8: magnifying view of figure (3-64) shows positive vascular, and paravascular cell (arrow). dab stain with counter stain hematoxylin. x400. figure 9: positive cd34 expression in pulp and dental sac area (arrow) of tooth mouse 7 days old treated with amnion. dab stain with counter stain hematoxylin, x400. figure 6: positive cd34 in endothelial cell of blood vessels in pulp of mouse 7 days old (control). dab stain with counter stain hematoxylin , x200. j bagh college dentistry vol. 25(2), june 2013 immunohistochemical study oral diagnosis 51 4at 13 days old mouse figure (14) shows positive expression of cd34 in blood vessels and endothelial cells. with amnion and chorion shows positive expression of cd34 as seen in figure (15, 16&17). amniotic fluid shows expression of cd34 marker in the newly formed blood vessels and in vascular endothelial cells (fig.18&19). figure 11: positive cd34 expression in apical area (arrow) of root formation in tooth of mouse 10 days old treated with amnion. dab stain with counter stain hematoxylin ,x400. figure 12: positive cd34 expression in pulp (p) and dental sac area include p.d.l and in stromal cell of newly formed bone (arrow) in tooth of mouse 10 days old treated with chorion. dab stain with counter stain hematoxylin, x200. figure 10: positive cd34 expression in pulp (p) and dental sac (arrows) in tooth of mouse 10 days old (control). dab stain with counter stain hematoxylin, x200. figure 13: positive cd34 expression in pulp and dental sac (ds) area include blood vessels in tooth of mouse 10 days old treated with amniotic fluid. dab stain with counter stain hematoxylin, x200. p p ds j bagh college dentistry vol. 25(2), june 2013 immunohistochemical study oral diagnosis 52 figure 14 figure 15 figure 16 figure 17 figure 18 figure 19 discussion positive expression of cd34 in pulp expressed by vascular endothelial cells and paravascular cells which may be endothelial cell or progenitor cells. also positive expression of cd34 was detected in pulp and dental sac of developing tooth at 4,7,10 and 13 day of eruptive periods of mouse and in different studied groups (amnion, chorion, amniotic fluid and control) but in different level and scoring. the present results reported an early eruption of mouse tooth at day 13 in amniotic fluid showing well arranged p.d.l groups, well developed surrounding bone and root formation, with angiogenesis illustrates in bone and p.d.l sites. for angiogenesis it creates change in blood volume and in turn increases vascular pressure. all these histological features aids in lifting up the tooth for eruption in supraosseous level. and all these features need for high cell proliferation that could be attributed to administration of stem j bagh college dentistry vol. 25(2), june 2013 immunohistochemical study oral diagnosis 53 cell from amniotic fluid. presentation of cd34 marker which is specifically expressed by the progenitors of the endothelial and mesenchyme was studied (6,7). abedini, et al (8) studied the cd34 and alkaline phosphatase activity of the stem cells in pulp of deciduous tooth and they propose the probable role of endothelial progenitor cells as well as the neural crest in the derivation of pulp stem cells. maltby et al (9) reported that various endothelial markers have been used in order to identify the antigen reactivity of vessels in a variety of tissues. and they illustrate cd34 marker in most of endothelial cells, and it has been suggest that cd34 regulate early events in blood cell migration and differentiation, and it may help in cell adhesion molecules. references 1poloni a, maurizi g, babini l, serrani f, berardinelli e, mancini s, costantini b, discepoli g, leoni p. human mesenchymal stem cells from chorionic villi and amniotic fluid are not susceptible to transformation after extensive in vitro expansion. cell transplant 2011; 20(5): 643-54. 2siegel n, rosner m, hanneder m, freilinger a, hengstschlager m. human amniotic fluid stem cells: a new perspective. amino acids 2008; 35(2): 291293. 3shuichi yoda, naoto suda, yutaka kitahara ,toshihisa komori, kimie ohyama. delayed tooth eruption and suppressed osteoclast number in the eruption pathway of heterozygous runx2/cbfa1 knockout mice. archives of oral biology 2004; 49(6): 435–442. 4dedeepiya v, rao yy, jayakrishnan g, parthiban jkbc, baskar s, manjunath s, senthilkumar r and abraham s. index of cd34+ cells and mononuclear cells in the bone marrow of spinal cord injury patients of different age groupsa comparative analysis. bone marrow research 2012; 8. 5attilacsordas tierneylab: new science blog hosted by the new york times. how to isolate amniotic stem cells from the placenta, at home! posted on january 23, 2007, boing boing. 6lee es, leong as, kim ys. calretinin, cd34 and alpha-smooth muscle actin in the identification of peritoneal invasive implants of serous borderline tumors of the ovary. mod pathol 2006; 19: 364-372. 7steidl u, bork s, schaub s, selbach o, seres j, et al. primary human cd34+ hematopoietic stem and progenitor cells express functionally active receptors of neuromediators. blood 2004; 104: 81-88. 8abdini f, foroutan t, jahangiri l. alkaline phosphatase and cd34 of reaction in deciduous teeth pulp stem cell. pakistan j biol sci 2007; 10: 31463149. 9maltby s, wohlfarth c, gold m, zbytnuik l, hughes mr, mcnagny km "cd34 is required for infiltration of eosinophils into the colon and pathology associated with dss-induced ulcerative colitis. am j path 2010; 177(3): 1244–54. j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 171 comparison of metal ions release and corrosion potential from different bracket archwire combinations (an in vitro study) asmaa m. khamees, b.d.s. (1) sami k. al-joubori, b.d.s., m.sc. (2) abstarct background: esthetic treatment is the options of patient seeking orthodontic treatment. therefore this study was conducted to measure the concentration of aluminum, nickel, chromium and iron ions released from combination of monocrysralline brackets with different arch wires immersed in artificial saliva at different duration, to evaluate the corrosion point on different parts of the orthodontic appliances before and after immersion in artificial saliva, and to evaluate the corrosion potential of each group of the orthodontic appliances. material and methods: eighty orthodontic sets prepared. each set represents half fixed orthodontic appliance, from the central incisor to the first molar, for the maxillary arch, each set consisted of molar band, five brackets, half arch wire and ligature elastic.these sets are divided into two groups: group a: with monocrystalline brackets divided into five subgroups (each subgroup has ten sets), but differ in arch wires, as numbered stainless steel, nickel-titanium, thermally activated, coated stainless steel and coated nickel-titanium arch wires respectively. group b: with stainless steel brackets divided into three subgroups (also each subgroup has ten sets), but differ in arch wires, as numberedstainless steel, nickel-titanium, and thermally activated arch wires respectively. used optical microscope to check the corrosion points, and used potentiostat techniques to indicate corrosion rate and tendency. results: the greatest concentration of aluminum and nickel ions release during the 1st week in group a, then sharply decreased in the 2nd week. the release of chromium ion released increase with increase intervals, while iron ion released decrease with increase time. both nickel and chromium ions increase with increase intervals in group b,while iron increase to the maximum at 3rd weeks, then began to degrease. optical microscope displayed pitting, crevices, and intergranular corrosion. potentiostat techniques indicated that increase corrosion when used stainless steel and coated nickel titanium than others arch wires with group a, while corrosion increase with nickel titanium than stainless steel arch wires with group b. conclusions: non-significant difference in the total nickel, chromium and iron release in group b. aluminum and iron increase in a4 and a5, while nickel and chromium increase in a1 and a2.the total released amounts of metals ions in both groups were less than the amounts of daily intake. key words: ions release, aluminum, nickel, chromium, iron. (j bagh coll dentistry 2014; 26(1):171-179). introduction in orthodontics a broad spectrum of stainless steels (1,2) and ti-based alloys (3)are used for the production of brackets and arch wires although the latter are mainly fabricated from ni-ti alloys (4). ceramic brackets when introduced overcome the partial of problems with aesthetic demand. ceramic brackets largely overcome the esthetic limitations of plastic brackets in that they are quite durable and resist staining. in addition, they can be custom-molded for individual teeth and are dimensionally stable, so that the precise bracket angulations and slots of the straight-wire appliance can be incorporated. most currentlyavailable ceramic brackets are produced from alumina, either as single-crystal (sapphire) or polycrystalline (ceramic) units came into the field of orthodontics. single-crystal brackets should offer greater strength than polycrystalline brackets, and fracture resistance is reduced to or below the level of the polycrystalline materials. (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2)assistant professor, department of orthodontics, college of dentistry, university of baghdad. because of the multiple crystals, polycrystalline alumina brackets have relatively rough surfaces, even though monocrystalline alumina is as smooth as steel, these brackets also show greater friction than steel, perhaps reflecting a chemical interaction between the wire and bracket material (5). a number of alternatives have been explored to create an esthetic arch wire that would allow efficient orthodontic treatment from the labial aspect (6).materials used in coating are polymers such as synthetic fluorine-containing resin or epoxy resin composed mainly of polytetrafluoroethylyene, which is used to simulate tooth color (7). these metallic arch wires coated with colored polymers or inorganic materials are currently the solution to this esthetic problem (8). the purpose of this in vitro study is to determine the ions release, corrosion points and corrosion tendency when used monocrystalline brackets with different arch wires and also compare them with stainless steel arch wires. j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 172 materials and methods eighty orthodontic sets prepared. each set represents half fixed orthodontic appliance, from the central incisor to the first molar, for the maxillary arch, these preparation and measurement were taken from model which prepared with fixed orthodontic appliance.each set consisted of molar band of similar size and closely weight, five brackets, half arch wire and finally ligated by ligature elastic.these sets are divided into two groups, group a: divided into five subgroups (each subgroup has ten sets, all with monocrystalline brackets), these subgroups numbered according to the arch wires: a1 stainless steel arch wires, a2 nickel-titanium arch wire, a3 thermally nickel-titanium arch wire, a4 coated stainless steel arch wire, and a5 coated nickel-titanium arch wire. group b: divided into three subgroups (also each subgroup has ten sets, all with stainless steel brackets),these subgroups numbered according to the arch wires: b1 stainless steel arch wires: b1 stainless steel arch wires, b2nickel-titanium arch wire, and b3thermally nickel-titanium arch wire. the samples immersed in ethanol for 4-5 seconds and then immersed in acetone for 8 seconds and dried in hot air and restored again, this is to get rid of any contaminants during ligation. neither the inner surface of the bands, nor the mesh of the brackets were covered by any material so that the exposed surface area of the appliance components was approximately equal to the exposed surface area of the bonded and banded full arch fixed orthodontic appliance (9). the artificial saliva which is testing solutions (the electrolytic media) used in this study consisted of 0.7g nacl, 1.2g kcl, 0.26g na2hpo4, 0.2g k2hpo4, 1.5g nahco3, 0.33g kscn, 0.13g urea and 1000 ml deionized water, ph of the saliva adjusted to 6.7 ± 0.10 using the phmeter, this ph value coincides with that reported of human saliva (9). each sample was placed in glass container, filled with 30 ml of artificial saliva, and closed by parafilm to control evaporation. to avoid saturation with the released ions during the incubation period, the solutions were changed four times with 7 days intervals (10). to measure ions [aluminum (al), nickel (ni), and chromium (cr)]used flameless atomic absorption spectrophotometer (aas) concentration (buck scientific/graphite furnace, 210 vgp, usa), while used spectrophotometer (cecil, 1011, france) to measure iron (fe) concentration.microscopical examination was done using optical microscope (mti corporation, 2700, camera 94804, usa), performed to determine the position and severity of corrosion in the components of fixed orthodontic appliance with 100x magnification. the potentiostat (m lab 200, germany) used to determine the e-corr (corrosion tendency) and icorr (corrosion rate) with different appliances combinations. results the greatest concentration of al ions release during the 1st week in all subgroup of group a, then sharply decreased in the 2nd week with significant difference between 1st week with all others weeks.the greatest ni release for a1, a4 and a5 noticed in the 1st week, while a2 and a3 in the 4th week then reduced at day (14), increased in (21) days, and the release then followed a regular pattern at the final intervals for all types of the appliances combination.the release of cr increase with intervals until reach the greatest level in the 3rd week for a1, a2, a3 and a4, and then decrease in 4th intervals,while in group a5 the cr increases with time to reach maximum at 4th week.the greatest fe ion released in the 2nd week in a1 and a3, while in the 1st week in a2, a4 and a5 tables (1-5).in group bthe amount of ni and cr ions increased with increased intervals for all subgroups.fe ions increased as the immersion time progressedespecially at 3rd weeks, and then decreased at 4th weeks table (6-8). the wing of the monocrystalline bracket was subjected to pitting and crevice corrosion appeared in all groups, but large pitting apparent in a1, while crevice more apparent in a2 and a3 figure 1, and no clearly appearance of corrosion in slots.the wings of stainless steel brackets showed slightly defect especially in b1 and b2 figure 2,while slot showed only minor pitting corrosion occur.the welder area between band and tube reflect intergranular corrosion, reveled more in groups with niti arch wires figure 7.stainless steel orthodontic arch wiresidentified clearly pitting and crevice corrosion in both bracket and band position figure 3.niti arch wires showedclearly pitting and with crevice corrosion in bracket position while more clearly appearance of large pitting corrosion in b2 figure 4.thermally activated niti arch wires showed clearly pitting and slightly crevice corrosion in bracket position while more clearly exhibition of large pitting corrosion in both a3 and b3 at band position figure 5.new coated stainless steel arch wiresdisplayed slightly solving the coated materials, with pitting corrosion in the uncoated area. in contact area also displayed solving the coated material with slightly pitting corrosion. new coated niti arch wires displayed clearly pitting corrosion at bracket position after tear out j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 173 coated area during used period. while band position were tested after used indicated more pitting and crevice corrosion on uncoated area. in contact area between coated and uncoated displayed pitting corrosion figure 6. e-corr and i-core values for the group a according to groups was as following table (9),ecorr and i-core values for the group b according to groups was as following table (10). discussion although aluminum oxide or alumina (al2o3) is an extremely stable compound with a high melting point, however consider all possible reactions. suppose the first step of the reaction is the reduction of al3+ and oxidation of the alkali metal (m) al2o3 + tm ----→ u mvow + xalyoz.… (1) the reaction with the most favorable change in energy for all alkali metals is: al2o3 + 6m ----→ 3m2o + 2al …… (2) these reactions allow al to be released; these reactions contribute a lot of energy to the overall reaction. for this reason oxygen has a detrimental effect on the alkali metal resistance of alumina (11). the reduction in the al ions concentration between the first and the other weeks may be due to the (3) reaction, that after released al ions then react with water to the reformation of the al2o3 as following: 2al+ h2o → al2o3 + 3h2 ………. (3) the results also may be due to (4) reaction, according to the research suggested that the enhancing effect of aluminum oxide on the reactivity of aluminum with water may also be mechanochemical in nature (12). al2o3+ 3h2o → 2alooh ….…… (4) alooh film growth and formation of h2 bubbles 6alooh+2al → 4al2o3 + 3h2 after reduction in of al in second week, there were slightly increase with intervals in a1 and a5 with non-significant differences between 2nd week with 3rd week, and 3rd week with 4th week, and these mainly related to the stability of the alumina formation by the reactions (3) or (4), also may be related to the arch wires. while in a2, a3, and a4 after reduction in of al in 2nd week, still continuous reduction with intervals, this related to the stability of the alumina formation by the reactions (3) or (4) which was more stable in these groups than previous groups, also may be related to the arch wires. the greatest ni release for a1, a4 and a5 was in the 1st week, therefore stainless steel and both coated arch wires taken the same pattern of corrosion with monocrystalline brackets, while a2 and a3 in the 4th week, from that niti and thermally niti took the same pattern of corrosion with these brackets.the release of cr increase with intervals until reach the greatest level in the 3rd week for a1, a2, a3, and a4, and then decrease in four intervals, these indicated that stability of the formation of the passive film began after 3rd week. while in a5 the cr increase with increase time to reach maximum at 4th week, this indicated that in the presence of the coated niti arch wire will delay formation of passive film by reduction of the oxygen.the greatest fe ion released in the 2nd week for a1 and a3, while in the 1st week for a2, a4 and a5, the release then reduced with increase time, because of the low amount of chromium comparing with the high amount of iron, it may not enough to produce such strongly adherent passivation layer of chromium oxide on the surface to prevent corrosion of iron (13). there was non-significant difference of total amount of al ion between a1, a2, and a3 even with different arch wires; this indicated that monocrystalline brackets took similar degree of corrosion with the uncoated arch wires, also there was non-significant difference between a4 and a5 and this may be indicated that monocrystalline bracket took similar degree of corrosion with coated arch wires. the greater total amount of ni and cr ions release in a1 and this may be due to the reaction (1) or (2), the composition percentage, and/or passive film stability. the chromium oxide passive films are not as stable as their titanium oxide and thus contribute to the inferior corrosion resistance of stainless steel relative to ti alloys (14,15), therefore more (ni and cr) ions released in a1 than other groups. total amount of fe ion release, more in coated than uncoated arch wires groups, these results depend specially on the manufacturing of the wires, and according to the researches showed that coated arch wires had low esthetic value after clinical used. the remaining coating showed a severe deterioration and a greater surface roughness compared to preclinical used (16). for the ni and cr ions, the greatest amount with b1, b2 and b3 noticed in the 4th week. the amount of ni and cr ions increased with intervals for all types of the appliances combination. these agreement with studies (17-19). but disagree with others (9,20-22). the results showed that the release of fe ions increased especially at 3rd weeks, and then decreased at 4th weeksthese agreement withstudies (15,18,23) and disagree with others (22).at the end of 28 days, the total ni, cr and fe release were non-significant difference in the levels in different groups, this agree with study (24). j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 174 the total amount of ni, cr and fe ions in all subgroups of both main groups were less than the cumulative daily intake. quantities of all released ions were below the toxic levels and did not exceed daily (9,18,24,25). corrosion in the form of pitting has been identified in brackets and wires, initiation of the process may take place before immersion placement since excessively porous surfaces have been found on as-received, these agrees with other studies (26,27). also crevice corrosion is obvious at different parts including bracket slots, the arch wire side at the bracket slot and the part passes through molar band tube. these agree with those mentioned by others (26). the crevice sites represent a harbor of stagnant solution and under the deposit area, oxygen depletion takes place, no further oxygen reduction occur, although the dissolution of the metal continues, this tend to produce an excess of positive charges in the solution that is balanced by migration of chloride ions to the crevice, caused increase concentration of metal-chloride within the crevice (28). microscopically examined of the arch wires both stainless steel and niti showed evidence of pitting formed on the wire surfaces, these agreement with other study (29). however, surface irregularities observed in niti arch wires, which are sites susceptible to selective dissolution of ni may arise from the manufacturing process, since the presence of manufacturing defects may accelerate the corrosion process (14,30). niti and thermally niti arch wires showed pitting corrosion more with stainless steel than monocrystalline groups due to a galvanic reaction. coated niti showed more corrosion than coated stainless steel arch wires. the surface defects produced during the manufacturing processes in molar band near the welded area, such manufacturing defect was observed by other (31), reveled more corrosion in groups with niti arch wires due to a galvanic reaction will occur. potentiostatic polarization curves associated with group a depend on the arch wire and band because monocryatalline brackets were insulator for electrical current. a1 and a2, both (e-corr) and (i-corr) with stainless steel indicated more corrosion tendency and higher corrosion rate than with niti arch wires. these results were coincidence with the results of atomic absorption spectrophotometer and spectrophotometer. while a3, both (e-corr) and (i-corr) indicated less corrosion and higher corrosion rate than above. both (e-corr) and (i-corr) with a5 indicated more corrosion tendency and higher corrosion rate with coated niti than coated stainless steel arch wires with a4, also microscopical examination indicated more corrosion with coated niti arch wires. in groups of stainless steel brackets, potentiostatic polarization curves associated with arch wire, band and brackets. b1 and b2, the analysis of the curves reveals the following: 1. the corrosion potential (e-corr) was higher in stainless steel than nickel-titanium arch wire. 2. the values of (i-corr) were higher in nickeltitanium than in stainless steel arch wire. 3. in b3, e-corr indicated less corrosion tendency, but high i-corr indicated higher corrosion rate. when contact with a dissimilar metal is made, the self-corrosion rates will change, corrosion of the anode will accelerate; corrosion of the cathode will decelerate or even stop. the two major factors affecting the severity of galvanic corrosion are (1) the voltage difference between the two metals, and (2) the size of the exposed area of cathodic metal relative to that of the anodic metal. corrosion of the anodic metal is both more rapid and more damaging as the voltage difference increases and as the cathode area increases relative to the anode area. e-corr values for appliances contain stainless steel arch wire was agreed with other studies (9,26). i-corr values it was higher in the presence of niti and thermo niti as compared with the presence of stainless steel arch wires, also agree with other study (9). references 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(ivsl). figure 1: monocrystalline bracket figure 2: stainless steel bracket figure 3: stainless steel arch wire new a1 a2 a3 a4 a5 new b1 b2 b3 a1bracket position b1 bracket position a1 band position b1band position j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 176 figure 4: nickel titanium arch wire figure 5: thermally nickel titanium arch wire figure 6: coated arch wire figure 7: band figure 7: band table 1: concentration (µg/ml) a1 a2 bracket position b2 bracket position a2 band position b2 band position a3bracket position b3bracket position a3band position b3band position ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value al 1st week 0.00529 0.00247 0.00078 0.0023 0.0091 16.38 0.000 (hs) 2nd week 0.001689 0.00021 0.00007 0.00129 0.00192 3rd week 0.002154 0.00012 0.00004 0.00199 0.00233 4th week 0.00313 0.00030 0.00010 0.00256 0.00341 ni 1st week 0.01396 0.00261 0.00082 0.0089 0.0182 151.475 0.000 (hs) 2nd week 0.002169 0.00048 0.00015 0.00125 0.00281 3rd week 0.003908 0.00011 0.00003 0.00371 0.00402 4th week 0.007264 0.00036 0.00011 0.00681 0.00774 cr 1st week 0.000352 0.00010 0.00003 0.00019 0.00051 32.593 0.000 (hs) 2nd week 0.000521 0.00013 0.00004 0.00029 0.0007 3rd week 0.000698 0.00002 0.00001 0.00066 0.00073 4th week 0.000446 0.00002 0.00001 0.00042 0.00047 fe 1st week 0.3202 0.033419 0.010568 0.288 0.392 13.156 0.000 (hs) 2nd week 0.3608 0.083518 0.026411 0.248 0.472 3rd week 0.3264 0.047673 0.015076 0.248 0.384 4th week 0.2208 0.025633 0.008106 0.184 0.256 new stainless steel used new niti used a1 a2 a3 a4 a5 b1 b2 b3 j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 177 table 2: concentration (µg/ml) a2 table 3: concentration (µg/ml) a3 table 4: concentration (µg/ml) a4 ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value al 1st week 0.00468 0.00175 0.00055 0.0025 0.0081 15.907 0.000 (hs) 2nd week 0.002628 0.00023 0.00007 0.00208 0.00287 3rd week 0.002696 0.00010 0.00003 0.00252 0.00283 4th week 0.002166 0.00011 0.00004 0.00201 0.00232 ni 1st week 0.00552 0.00212 0.00067 0.0023 0.0098 23.578 0.000 (hs) 2nd week 0.002717 0.00048 0.00015 0.00226 0.00357 3rd week 0.003561 0.00004 0.00001 0.00349 0.00361 4th week 0.006339 0.00024 0.00008 0.00598 0.00665 cr 1st week 0.000195 0.00004 0.00001 0.00012 0.00025 29.382 0.000 (hs) 2nd week 0.000348 0.00016 0.00005 0.00019 0.00071 3rd week 0.000564 0.00007 0.00002 0.00048 0.00069 4th week 0.000408 0.00001 0.00000 0.0004 0.00042 fe 1st week 0.3152 0.02269 0.007175 0.264 0.336 38.564 0.000 (hs) 2nd week 0.3072 0.044173 0.013969 0.248 0.384 3rd week 0.1866 0.038598 0.012206 0.136 0.242 4th week 0.2128 0.02173 0.006872 0.184 0.248 ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value al 1st week 0.00634 0.001862 0.000589 0.0028 0.0093 46.116 0.000 (hs) 2nd week 0.003462 0.00023 0.00007 0.00315 0.00382 3rd week 0.00269 0.00004 0.00001 0.00263 0.00275 4th week 0.00154 0.00033 0.00011 0.00121 0.00202 ni 1st week 0.00403 0.00120 0.00038 0.0023 0.0059 94.520 0.000 (hs) 2nd week 0.001107 0.00015 0.00005 0.00089 0.0013 3rd week 0.003272 0.00010 0.00003 0.00312 0.00345 4th week 0.005588 0.00009 0.00003 0.00544 0.00571 cr 1st week 0.000534 0.00013 0.00004 0.00034 0.00076 16.095 0.000 (hs) 2nd week 0.000307 0.00008 0.00003 0.00019 0.00044 3rd week 0.000502 0.00005 0.00002 0.00044 0.00061 4th week 0.000391 0.00001 0.00000 0.00038 0.0004 fe 1st week 0.344 0.069128 0.02186 0.248 0.432 43.998 0.000 (hs) 2nd week 0.4496 0.063978 0.020232 0.352 0.536 3rd week 0.2418 0.0406 0.012839 0.174 0.292 4th week 0.2 0.028472 0.009004 0.176 0.256 ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value al 1st week 0.00871 0.00079 0.00025 0.0076 0.0099 499.376 0.000 (hs) 2nd week 0.003462 0.00023 0.00007 0.00315 0.00382 3rd week 0.002762 0.00007 0.00002 0.00269 0.00291 4th week 0.002288 0.00015 0.00005 0.00211 0.00256 ni 1st week 0.00665 0.00098 0.00031 0.0055 0.0082 22.988 0.000 (hs) 2nd week 0.003438 0.00198 0.00063 0.00083 0.00614 3rd week 0.00292 0.00011 0.00003 0.00275 0.00305 4th week 0.00497 0.00010 0.00003 0.00481 0.00515 cr 1st week 0.000336 0.00008 0.00002 0.00022 0.00044 21.902 0.000 (hs) 2nd week 0.000204 0.00006 0.00002 0.00013 0.00031 3rd week 0.000376 0.00004 0.00001 0.00029 0.00042 4th week 0.000359 0.00002 0.00001 0.00033 0.00038 fe 1st week 0.5072 0.06324 0.019998 0.44 0.632 69.073 0.000 (hs) 2nd week 0.2768 0.037938 0.011997 0.24 0.36 3rd week 0.29705 0.036262 0.011467 0.2275 0.344 4th week 0.2256 0.046464 0.014693 0.152 0.304 j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 178 table 5: concentration (µg/ml) a5 table 6: concentration (µg/ml) b1 table 7: concentration (µg/ml) b2 ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value al 1st week 0.01065 0.002008 0.000635 0.0064 0.0142 172.348 0.000 (hs) 2nd week 0.001929 0.000310 0.000098 0.00143 0.00241 3rd week 0.002224 0.000036 0.000011 0.00217 0.00229 4th week 0.002416 0.000182 0.000058 0.00204 0.00261 ni 1st week 0.00811 0.000504 0.000159 0.0072 0.0088 423.728 0.000 (hs) 2nd week 0.002038 0.000608 0.000192 0.00109 0.00312 3rd week 0.002704 0.000077 0.000025 0.00261 0.00284 4th week 0.004426 0.000260 0.000082 0.00392 0.00465 cr 1st week 0.000284 0.000058 0.000018 0.0002 0.00038 4.375 0.000 (hs) 2nd week 0.000262 0.000032 0.000010 0.00019 0.00031 3rd week 0.000284 0.000020 0.000006 0.00025 0.00031 4th week 0.000318 0.000009 0.000003 0.00031 0.00033 fe 1st week 0.4448 0.070975 0.022444 0.312 0.512 11.696 0.000 (hs) 2nd week 0.3056 0.035337 0.011175 0.264 0.368 3rd week 0.3081 0.031827 0.010065 0.264 0.36 4th week 0.352 0.084664 0.026773 0.232 0.488 ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value ni 1st week 0.0061 0.00018 0.00006 0.0058 0.0064 207.337 0.000 (hs) 2nd week 0.00608 0.00019 0.00006 0.0058 0.0064 3rd week 0.00741 0.00018 0.00006 0.0071 0.0077 4th week 0.00783 0.00023 0.00007 0.0075 0.0082 cr 1st week 0.000406 0.00003 0.00001 0.00036 0.00045 74.711 0.000 (hs) 2nd week 0.00044 0.00002 0.00001 0.00041 0.00049 3rd week 0.00052 0.00002 0.00001 0.00049 0.00055 4th week 0.000572 0.00004 0.00001 0.00051 0.00061 fe 1st week 0.4696 0.108848 0.034421 0.24 0.576 10.330 0.000 (hs) 2nd week 0.4208 0.1398 0.044209 0.28 0.624 3rd week 0.568 0.122086 0.038607 0.424 0.744 4th week 0.2954 0.058606 0.018533 0.2 0.36 ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value ni 1st week 0.0067 0.00015 0.00005 0.0065 0.0069 87.088 0.000 (hs) 2nd week 0.00626 0.00022 0.00007 0.0059 0.0066 3rd week 0.00766 0.00028 0.00009 0.0072 0.0081 4th week 0.00766 0.00028 0.00009 0.0074 0.0083 cr 1st week 0.000368 0.00004 0.00001 0.00031 0.00044 75.926 0.000 (hs) 2nd week 0.000413 0.00002 0.00001 0.00039 0.00045 3rd week 0.00052 0.00002 0.00001 0.00049 0.00055 4th week 0.000556 0.00004 0.00001 0.00049 0.00061 fe 1st week 0.3472 0.051873 0.016404 0.264 0.44 30.972 0.000 (hs) 2nd week 0.28 0.069128 0.02186 0.192 0.384 3rd week 0.61625 0.085399 0.027006 0.456 0.7145 4th week 0.4387 0.112637 0.035619 0.32 0.632 j bagh college dentistry vol. 26(1), march 2014 comparison of metal orthodontics, pedodontics and preventive dentistry 179 table 8: concentration (µg/ml) b3 table 9: values of group a table 10: value of group b ions duration descriptive statistics (n= 10) group comparison mean s.d. s.e. min. max. f-test p-value ni 1st week 0.0063 0.00018 0.00006 0.006 0.0066 129.085 0.000 (hs) 2nd week 0.00686 0.00016 0.00005 0.0066 0.0071 3rd week 0.00738 0.00018 0.00006 0.0071 0.0076 4th week 0.00776 0.00019 0.00006 0.0075 0.0081 cr 1st week 0.000348 0.00003 0.00001 0.00031 0.0004 252.605 0.000 (hs) 2nd week 0.000438 0.00002 0.00001 0.00041 0.00047 3rd week 0.000528 0.00001 0.00000 0.00051 0.00055 4th week 0.00058 0.00002 0.00001 0.00055 0.00061 fe 1st week 0.2848 0.071475 0.022602 0.184 0.384 101.890 0.000 (hs) 2nd week 0.2944 0.056669 0.01792 0.24 0.432 3rd week 0.76265 0.063254 0.020003 0.644 0.8375 4th week 0.4496 0.084899 0.026847 0.344 0.568 group a e-corr i-core a1 -159.4 2.42 a2 -144.5 2.29 a3 -164.1 3.02 a4 -157.3 1.38 a5 -195.2 1.96 group b e-corr i-core b1 -111 1.92 b2 -125.7 3.7 b3 -12 4.96 banaz f.doc j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 97 periodontal health status of heavy and light smokers and its correlation with salivary superoxide dismutase enzyme (a comparative study) banaz j. ali, b.d.s. (1) leka'a m. ibrahim, b.d.s., m.sc. (2) ali y. majid, m.b.ch.b., m.sc., f.i.c.m.s. (3) abstract background: periodontal disease is a chronic bacterial infection that affects the gingiva and bone supporting the teeth. smoking, which is an important risk factor for periodontitis, induce oxidative stress in the body and cause an imbalance between reactive oxygen species (ros) and antioxidants, such as superoxide dismutase (sod). this study aimed to evaluate the influence of smoking on periodontal health status by estimating the levels of salivary sod level in non-smokers (controls) and light and heavy smokers and to test the correlation between the sod enzyme level and the clinical periodontal parameters in each group. materials and methods: the study sample consisted of 75 male, with age ranged from 35 to 50 years. clinically, the periodontal parameters used in this study were plaque index (pli). gingival index (gi), probing pocket depth (ppd), bleeding on probing (bop) and clinical attachment level (cal), unstimulated saliva sample were collected from all subjects and the levels of superoxide dismutase enzyme was analyzed for each group , and correlate the mean of salivary enzyme levels with the clinical periodontal parameters. results: highly significant differences in pli between (non smokers/heavy smokers) and (light smokers/heavy smokers).on the other hand no significant difference in gingival index between groups. there were a high association between severity of smoking & probing pocket depth and there is association between severity of smoking and clinical attachment loss. there were a significant difference in the level of salivary superoxide dismutase enzyme between the (non smokers/light smokers) groups & between (heavy smokers/light smokers) &there were highly significant differences between (non smokers/heavy smokers) groups. there is no correlation between the activities of the salivary superoxide dismutase enzyme and the clinical periodontal parameters except in sod with (bop score 0 and ppd score 1&score 3) in heavy smokers group. conclusions: superoxide dismutase enzyme can be used as biomarker for estimating the level of oxidative stress on smoking habits. key words: periodontal health status, superoxide dismutase, heavy and light smoking. (j bagh coll dentistry 2013; 25(3):97-102). introduction periodontal disease is a chronic disease of the oral cavity comprising a group of inflammatory conditions affecting the supporting structures of the dentition (1, 2). saliva is an aqueous fluid found in the oral cavity, composed of a complex mixture of secretory products (organic and inorganic products from the salivary glands and other substances coming from the oropharynx, upper airway, gastrointestinal reflux, gingival sulcus fluid, food deposits, and blood-derived compounds (3,4) . for the local inflammatory process of periodontitis, salivary diagnostics may promote early diagnosis and aid in the monitoring of treatment (5). for some diagnostic purposes, salivary biomarkers may prove more useful than serum analysis (6). the severity of the periodontitis process can be modified by a variety of factors, the most important risk factor markedly affected the initiation and progression of periodontitis was smoking (7,8). (1) m.sc. student, department of periodontics, college of dentistry, baghdad university. (2) professor, department of periodontics, college of dentistry, baghdad university. (3) consultant. cigarette consumption and duration of smoking are associated with the severity of periodontal disease. the more tobacco is smoked the more periodontal attachment loss has been observed (9). heavy smokers were more likely to suffer from periodontitis than non-smokers, with light smokers less likely to have this problem (10). smoking induces oxidative stress in the body and causes an imbalance between reactive oxygen species (ros) and antioxidants, such as superoxide dismutase (sod), the role of reactive oxygen species (ros) has been established in the pathogenesis of periodontitis, in healthy individuals, ros are produced during various physiologic processes. normally there is a balance between ros and antioxidants that may be disturbed by a variety of factors, including smoking (11). this dysregulation may damage the cells by variant mechanisms, such as peroxidation of lipid membranes, protein inactivation, and induction of (deoxyribonucleic acid) dna damage. (12) superoxide (o2•-) is biologically quite toxic and is deployed by the immune system to kill invading microorganisms in phagocytes, superoxide is produced in large quantities by the enzyme nicotinamide adenine dinucleotide j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 98 phosphate (nadph) oxidase for use in oxygendependent killing mechanisms of invading pathogens .because superoxide is toxic, nearly all organisms living in the presence of oxygen contain isoforms of the superoxide scavenging enzyme, superoxide dismutase (sod) (13). sod is an antioxidant enzyme that acts against superoxide, oxygen radical that is released in inflammatory pathways and causes connective tissue breakdown. this enzyme is released as a homeostatic mechanism to protect the tissues, and it can be detected in extraand intracellular compartments (14,15). measurement of sod in human saliva might be useful for estimating the level of oxidative stress on smoking habits. materials and methods human samples:consist of 75 subjects ,male only with age range (35-50) years old , attending the oral diagnosis department in the college of dentistry / al-mustansiria university and divided into 3 groups: group 1 (g1):composed of 25 non smokers group2 (g2):composed of 25 light smokers (who smoke ≤10 cig/day) for the last five years (16). group 3 (g3):composed of 25 heavy smokers (who smoke ≥10cig/day) for the last five years (16) all the subjects were in a good health, with no history of systemic disease, no a history of regular use of mouth washes, no special dietary requirements and did not take vitamins or minerals supplements or medication of any type. the periodontal examination includes: 1-assessment of dental plaque by pli of sillenes and loe (17) 2assessment of gingival condition by gi of loe and silness (18) 3probing pocket depth (ppd) a scale was designed for ease of estimation and as follows: scale 1 = 0-3 mm scale 2 = >3-5 mm scale 3 =>5-7mm scale 4 =>7mm 4assessment of clinical attachment level (cal). a scale was designed for ease of assessment as follows: scale 1= 1-3 mm scale 2= >3-5 mm scale 3= >5-7 mm scale 4= >7mm biochemical analysis: the biochemical analysis includes measuring the concentrations of superoxide dismutase enzyme in saliva. (spectrophotometric) principle of reaction: the o2substrate for sod is generated indirectly in the oxidation of epinephrine at alkaline ph by the action of oxygen on epinephrine. as o2builds in the solution, the formation of adrenochrome accelerates because o2also reacts with epinephrine to form adrenochrome. toward the end of the reaction, when the epinephrine is consumed, the adrenochrome formation slows down. super oxide dismutase enzyme reacts with the o2formed during the epinephrine oxidation and therefore slows down the rate of formation of the adrenochrome as well as the amount that is formed. because of this slowing process, sod is said to inhibit the oxidation of epinephrine. statistical analysis: data were analyzed through the use of spss (statistical process for social science).the following statistical data analysis approaches were used in order to analyze and assess the results of the study: i. descriptive data analysis: arithmetic mean, standard deviation, standard error, two extreme values (min. and max.) of the calculated. ii. inferential data analysis: these were used to accept or reject the statistical hypotheses, which included the student t-test for equality of means of two independent groups. also, pearson's correlation coefficient was used for testing the correlation between the two independent variables; the clinical and biochemical parameters results clinical parameters: the mean and standard deviation of pli&gi for the groups are (0.936 ±0.415) (0.940 ±0.355) respectively for group 1 , (0.942 ±0.504) (0.9563±0.1680) respectively for group 2 and (1.333 ±0.407) (1.005±0.204) respectively for group 3 . as shown in table (1). statistical analysis using the t-test to compare the mean of plaque index & gingival index between each two groups ,regarding pli there was no significant difference between g1 and g2 while a highly significant difference were found between g1and g3, g2and g3 as shown in the table (2). regarding gingival index, there was no significant difference between the groups. there was a high association between severity of smoking & probing pocket depth and there is association between severity of smoking and clinical attachment loss. as shown in the table (4). biochemical parameters: the mean and standard deviation of sod level in g1 (52.128±9.421)u/ml was higher than the other group, the mean and standard deviation of superoxid dismutase for g2 was(45.976 ±11.85)u/ml and for g3 was(37.244±15.657) u/ml. as shown in the table (5). j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 99 statistical analysis using the t-test to compare mean between each groups revealed that there were a significant difference between the g1 andg2, g3and g2 and there were a highly significant difference between g1and g3 as shown in the table (6). correlation between clinical and biochemical parameters: there is no correlation between the activities of the salivary superoxide dismutase enzyme and the clinical periodontal parameters except in sod with bop in score 0, there is significant positive strong correlation in heavy smokers group and with ppd in (score 1, there was significant positive week correlation & in score 3, there was significant negative week correlation) both in heavy smokers as shown in the table (7). discussion clinical periodontal health parameters: dental plaque (pli) significant difference was found between light smokers and heavy smokers group i.e. more plaque accumulation in heavy smokers group than non smokers group. this increased level of plaque which have been observed in smokers have been tentatively attributed to personality traits leading to decreased oral hygiene habits in smokers, this agree with muller et al,sreedhar & shobha (19,20) who showed smokers have a higher prevalence of dental plaque than non-smokers and disagree with jayashree & vandana (21) who found that plaque level was similar in smokers and non-smokers. this indicated that smoking did not appear to increase the amount of plaque when controlling for other factors. besides, heat and accumulated product of combustion that result in tobacco stain as well as calculus are particular undesirable local irritants that increased with smoking (22). non significant difference was found between the non smokers and light smokers groups and this might be explained from the case sheet data which shows a high level of education in majority of light smoker groups gingival index (gi) the results showed that the gingival index in heavy smokers group was slightly elevated compared with non-smokers and light smoker, with non significant differences between them. according to the results, it has been found that smokers had slightly elevated gingival index than non-smokers, the explanation for the result that these alterations of gingival index follow physiologic changes related to the disease process (more plaque accumulation in smokers group lead to more gingival inflammation). this disagrees with darby et al (23) who showed that smokers had a decreased expression of clinical inflammation in the presence of plaque accumulation when compared with non-smokers. probing pocket depth (ppd) and clinical attachment loss (cal) according to the results, there were increased ppd with its different scores in smokers group compared with non-smokers group. this general increase in ppd in smokers group compared with non-smokers group was in a agreement with haffajee & socransky, calcina et al (24,25) there were an increased in cal with its different scales in smokers group compared with non-smokers group, and this came in agreement with susin et al & bajloon (26,27) it was shown that deleterious effects of smoking on periodontium resulted not only from plaque amount and poor oral hygiene, but also from the effect of direct tissue destruction of smoking in homogen groups. it has been suggested that smoking may also be a risk factor for gingival recession in adults with minimal periodontal destruction (28). regarding the duration of smoking, a significant association was noted between gingival other recession and duration of smoking in the present study. this finding is consistent with other observations (19). all scores were less in light smokers compared with non smokers group may be because most of the light smokers group was found to be educated patient from the record obtained from the case sheet. biochemical finding the mean of sod level in control group was higher than the other groups, and the mean of sod level in light smokers group was higher than heavy smokers group. according to the results, the mean level of salivary sod activity was significantly lower in the smokers group than non-smokers. this finding is agreed with reddy et al, agnihotri et al (11,29) and in disagreement with kanehira et al, baharvand (15,30) who showed that cigarette smoke leads to an elevation in salivary superoxide dismutase activity. the result showed elevated level of sod in light smokers compared with heavy smokers and this agree with agnihotri et al (11) who showed that mean levels of sod in the gcf and saliva of heavy smokers were lower than those in light smokers. the reduction of the antioxidative enzyme might be due to the excessive release of oxidative free radicals caused by cigarette smoke, which consumes the enzymes and are more utilized in the cellular process (31-33). j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 100 this reduction in the levels of sod may be related to an increased concentration of cadmium in cigarette smoke. cadmium replaces the bivalent metals in sod, such as zinc, copper, and manganese, resulting in its inactivation. an increased accumulation of cadmium in blood and a decrease in the levels of sod enhance the destructive process (34). the saturation of already present sod by the increased concentration of free radicals in cigarette smoke is another possible mechanism for the increased destruction of the periodontium, especially in heavy smokers (35). a dose-related reduction of salivary and gingival crevicular fluid superoxide dismutase levels was found in both light and heavy smokers compared to nonsmokers (11) correlation of sod levels with clinical periodontal parameters: in this study, there is negatively non significant relation between salivary superoxide dismutase with plaque index and gingival index. there is no statistically significant correlation between pocket depth and sod except with score one and three in heavy smoker and no statistical significant correlation between sod and clinical attachment loss. the delicate balance between the ros and tissue concentrations of antioxidants may be disturbed by various factors, including smoking. (36) elevated levels of ros stimulate the neutrophils to upregulate the adhesion integrins, leading to their increased accumulation in tissues and a local sealing off of antioxidant enzymes, such as sod, catalase, and protease inhibitors (37), consequent to this, there is degradation and collagenolysis of ground substance or increased stimulation of excessive proinflammatory cytokines through nuclear transcription factorkappa b activation or an increased production of prostaglandin e2 via lipid peroxidation and superoxide release; all are linked to bone resorption (38). there was a decrease in the levels of sod as cal and ppd increased. these findings are in accordance with (39) references 1. giannobile wv, beilker t, kinney js, ramseier ca, morelli t, wong dt. saliva as a diagnostic tool for periodontal disease: current state and future directions. periodontol 2000 2009; 50: 52-64. 2. armitage gc. development of a classification system for periodontal diseases and conditions. ann periodontol 1999; 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3:76-87. 38. alfano mc. the origin of gingival fluid. j theor biol 1974; 47:127-36. 39. ellis sd, tucci ma, serio fg, johnson rb. factors for progression of periodontal diseases. j oral pathol med 1998; 27:101-5. table 1. statistical description of pli &gi findings (mean, standard deviation) for three groups clinical parameter g1 g2 g3 mean sd mean sd mean sd pli 0.936 ±0.415 0.942 ± 0.504 1.333 ± 0.407 gi 0.940 ± 0.355 0.956 ± 0.167 1.005 ±0.205 table 2. inter groups comparison of means of plaque index &gingival index for all groups. gingival index plaque index groups sig p-value t-test sig p-value t-test ns 0.839 0.204 ns 0.961 0.5 g1-g2 ns 0.433 -0.791hs 0.001 3.41 g1-g3 ns 0.361 -0.922hs 0.004 3.007 g2-g3 table 3. numbers and percentages of probing pocket depth &clinical attachment loss sites for three groups cal pd groups score4 score3 score2 score1 score4 score3 score2 score0 % no % no % no % no % no % no % no % no 0.194 5 0.272 7 1.516 39 6.415 165 0.194 5 0.583 15 2.566 66 96.65 2486 g1 0.2 5 0.44 11 1.482 37 3.285 82 0.2 5 0.6 15 1.682 42 96.52 2434 g2 0.353 9 0.511 13 3.577 91 13.05 332 0.235 6 0.668 17 3.53 90 95.55 2431 g3 table 4. association between severity of smoking &clinical attachment loss, probing pocket depth by using chi-square test sig p-value df chi-square group cal ppd cal ppd cal ppd cal ppd s hs 0.015 0.00 6 6 15.704 17.477 g1 g2 g3 j bagh college dentistry vol. 25(3), september 2013 periodontal health oral and maxillofacial surgery and periodontics 102 table 5. statistical description (mean level in u/ml, standard deviation) of sod for each group g3 g2 g1 group 37.244 45.976 52.128 mean u/ml ± 15.657 11.85± ± 9.421 sd table 6. inter group comparison of mean of sod level by using t-test sig. p-value t-test group s* 0.048 2.032 g1-g2 hs** 0 4.072 g1-g3 s* 0.031 2.223 g2-g3 table 7. the coefficients of pearson correlation (r) of sod levels with clinical periodontal parameters and their level of significant differences cal ppd gi pli groups score4 score3 score2 score1 score3 score2 score1 score0 -0.150 -0.258 -0.331 -0.116 -0.017 0.265 0.101 -0.187 0.127 0.039 r g1 0.474 0.213 0.106 0.581 0.934 0.2 0.632 0.37 0.545 0.852 p-value ns ns ns ns ns ns ns ns ns ns sig -0.206 0.117 0.17 -0.215 0.082 -0.008 0.098 0.069 0.099 -0.055 r g2 0.324 0.578 0.417 0.301 0.695 0.97 0.642 0.744 0.637 0.779 p-value ns ns ns ns ns ns ns ns ns ns sig 0.082 -0.205 -0.218 -0.175 -0.047 -0.429 -0.020 0.439 -0.351 -0.267 r g3 0.696 0.326 0.296 0.403 0.824 0.032 0.926 0.028 0.085 0.196 p-value ns ns ns ns ns s ns s ns ns sig yasamin.doc j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 92 a comparative immunohistochemical expression of cyclin d1 in keratocystic odontogenic tumor, dentigerous and radicular cysts yasamin hamid al-amiri, b.d.s. (1) lehadh m. al-azzawi, b.d.s., m.sc., ph.d. (2) abstract background: odontogenic cysts include a group of osseodestructive lesions that frequently affect the jaws. those cysts could derive from odontogenic epithelium and occur in the tooth-bearing regions of the jaws. the aims of this study were to evaluate the immunohistochemical expression of cyclin d1 in keratocystic odontogenic tumor, dentigerous cyst and radicular cyst in epithelium and connective tissue capsule. materials and methods: in this study, thirty formalin fixed paraffin embedded tissue blocks of odontogenic cysts and tumor, consist of 14 keratocystic odontogenic tumor, 8 dentigerous cysts and 8 radicular cysts were analyzed immunohistochemically for the presence of cyclin d1 proteins. results: strong to moderate expression of cyclin d1 in epithelium was found in keratocystic odontogenic tumor cases with positive cases percentage was (85.7%). statistical significant differences (p<0.001) observed when comparing the three lesions. immunoreactivity of cyclin d1 in stroma of keratocystic odontogenic tumor was higher than in dentigerous cysts and radicular cysts cases. however, the difference was not statistically significant (p<0.067). conclusion: the results of this study propose that high expression rate of cyclin d1 might be one of the reasons for aggressive behavior of keratocystic odontogenic tumor and high recurrence rate. key words: keratocystic odontogenic tumor, dentigerous cysts, radicular cysts, cyclin d1, immunohistochemistry. (j bagh coll dentistry 2016; 28(1):92-98). introduction odontogenic cysts are sub-classified as developmental or inflammatory in origin with different clinical and biological behaviors, odontogenic keratocyst (okc) and dentigerous cyst (dc) are developmental in origin whereas, radicular cyst (rc) is an inflammatory in origin, which derived from the epithelial rest of malassez. amongst these, odontogenic keratocyst demonstated aggressive behavior and higher recurrence rate (1). odontogenic keratocyst presents as a cystic structure similar to that of dc andrc, but its infiltrative and destructive growth is similar to that of ameloblastoma (2). several investigators have proposed that odontogenic keratocysts be regarded as benign cystic neoplasms rather than cysts, and in the latest who classification of odontogenic tumors, these lesions have been given the term “keratocystic odontogenic tumor.” “kcot” the arguments to support this change in nomenclature largely depend on a few studies that have shown certain molecular genetic alterations that are also present in some neoplasms, but little studies have analyzed other cystic lesions of the jaws; therefore, there is some confusion about these alterations whether are unique to the odontogenic keratocyst (3). okcs accounted for approximately 3-11% of all cysts in the jaws; when regarded as cyst. they occurred in all ages, with a peak incidence in the second and fourth decades of life. there was a slight male predilection (4). kcot can be found in the mandible and the maxilla but are twice as common in the mandible, with a predilection for the angle and ascending ramus (5). dc were the most common developmental oc and comprised 18.1% of all oc (6). dcs were discovered most frequently in patients between 10 and 30 years of age. there was a slight male predilection. dcs might occur in association with any unerupted tooth; most frequently mandibular third molars. other moderately frequent sites included maxillary canines, maxillary third molars, and mandibular second premolars. occasionally, they were associated with supernumerary teeth or odontomas. dcs rarely involved unerupted deciduous teeth (7). there are some dcs reported to have a certain neoplastic potential manifested by ameloblatomatous transformation to form a unicystic ameloblastoma(8). rcs represented the most frequently encountered jaw cyst 9. they constituted nearly one half to three fourths of all cysts in the jaws. the age distribution peaked in the third through sixth decades (5). rcs were most common in the anterior maxillary area, especially in association with the lateral incisor teeth. rcs were more common in males than females (6). some cases of rc could grow and reach a considerable size, associated with local destruction (8). cyclin d1 is one of the rb pathway proteins with oncogene properties which control g1-s transition. elevated levels of this protein might permit cells to escape from the cell cycle check j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 93 point control and play an important role in tumorigenesis. cyclin d1 is expressed in various types of malignant tumor whereas negative or weakly expressed in normal tissue and benign tumors (10). cyclin d1 served as a key sensor and integrator of extracellular signals of cells, mediating its function through binding both the cdks and histone acetylase and histone deacetylases to modulate local chromatin structure of the genes that were involved in regulation of cell proliferation anddifferentiation (11). the availablity of cyclin d1 was induced by growth factors including epithelial growth factor and insulin growth factor (igf) iandii; amino acids and hormones, each regulated expression of cyclin d1 in specific cell types (12,13). amplification or overexpression of cyclin d1 played key roles in the development of a subset of human cancers including parathyroid adenoma, breast cancer, lymphoma, melanoma, colon cancer, prostate cancer, head and neck squamous cell carcinoma (14). the aims of the present study were to evaluate the immunohistochemical expression of cyclin d1 in keratocystic odontogenic tumor, dentigerous cyst and radicular cyst in epithelium and conecctive tissue capsule. materials and methods in current study, thirty formalin fixed paraffin embedded tissue blocks of odontogenic cysts , consist of 14 keratocystic odontogenic tumor, 8 dentigerous cysts and 8 radicular cysts were analyzed immunohistochemically for the presence of cyclin d1 proteins. positive staining indicates a lack of specification of the antibody and breast carcinomas were used as positive control for cyclin d1 according to abcam manufacturer’s data sheets. immunohistochemistry sections of 5µm were deparaffinized in xylene and rehydrated in graded alcohol. enough drops of hydrogen peroxide block were added to slides and incubated in humid chamber at 37c° for 10 minutes, and then socked 2 times in buffer (5 minutes for each). then tissue retrieving is done to the slides in order to uncover antigenicity because formalin or other aldehyde fixation forms protein cross-links that mask antigenic sites in tissue specimens. after that enough drops of protein block were added to slides and incubated at 37°c for 10 minutes. then washed 2 times in buffer (5 minutes for each), finally drained and blotted gently. then diluted primary antibody was applied to each slide, incubated in humid chamber at 37°c. overnight. early in the next day, the slides were washed in buffer (4 times for each), finally drained and blotted gently as before. next enough drops of secondary antibody reagent were added and incubated in humid chamber for 30 minutes at 37°c. after that, the slides were washed 4 times in buffer (5 minutes for each), finally drained and blotted gently. then streptavidine-hrp antibodies were applied on tissue and incubated for 30 minutes at 37°c. later diluted dab was applied on tissue (this process was done in dark room) and incubated in humid chamber for 10 minutes at 37°c. then slides washed carefully in tap water for 5 minutes. after that the slides were bathed in hematoxylin counterstain for 1-2 minutes then they were rinsed with tap water for 10 minutes. later the slides were dehydrated by immersing them in ethanol and xylene containing jars then one to two drops of dpx mounting medium were applied to the xylene wet sections and covered with cover slips and left to dry overnight. then the results were evaluated by the presence of brown coloured end product at the site of target antigen (nucleus) was indicative of positive immunoreactivity. percentage of ihc positive cystic cells per highlighting area was calculated and the mean percentage per slide was determined. assessing the expression of cyclin d1 in this study was classified as positive which showed brown nuclear staining in epithelial cells and connective tissue cells, whereas others were defined as negative. the positive cases were classified to additional categories, focal and diffuse expression. the slides were also evaluated for intensity of staining as mild, moderate and strong. moreover, the epithelial layers predominantly containing the positive cells were noted in each group 1. immunoreactivity of cyclin d1 was classified as follows into four categories according to the percentage of positively stained nuclei in the entire sections: (score 0) (-ve) < 5% or less of epithelialand stromal cells positive. (score 1) (+) 5-25%. (score 2) (++)> 25-50%. (score 3) (+++)> 50 % or more of epithelial and stromal cells positive 15. statistical analysis all the clinical, histopathological and immunohistochemical relevant data so obtained was tabulated and subjected to appropriate statistical analysis using the spss 17 statistical software. numerical values were used in this study for describing the variables which includes: j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 94 median, maximum, minimum and mean ± sd for age, cyclin d1 protein expressions. categorical variables which include: sites, sex and clinical presentation were described using number and percentage. non parametric chisquare test was used to evaluate the difference between the scores. kruskall-wallis h test used for ordinal variable followed by mann-whitney u test was used to find the relation between two cystic lesions. p value equal or less than 0.05 was considered to be statistically significant. results cyclin d1 immunoreactivity was noticed as brown staining localized in the nucleus of both epithelial and mesenchymal cells (figures 1 to 6). strong to moderate expression of cyclin d1 in epithelium was found in odontogenic keratocysts cases with positive cases percentage was (85.7%).statistical significant differences (p<0.001) observed when comparing the three lesions. immunoreactivity of cyclin d1 in stroma of keratocystic odontogenic tumor was higher than in dentigerous cysts and radicular cysts cases. however, the difference was not statistically significant (p<0.067). table 1: age, sex, and site distribution for cases with kcot, dc and rc of the jaw variable kcot(14) dc (8) rc(8) age mean±sd 30.36±13.80 24.50±17.26 29.50±20.38 minimum 12 5 11 maximum 57 50 63 sex male 10(71.43%) 4(50%) 5(62.5%) female 4(50%) 4(50%) 3(37.5%) site maxilla 5(35.71%) 6(75%) 7(87.5%) mandible 9 (64.29%) 2(25%) 1(12.5%) table 2: cyclin d1 score distribution in the cystic epithelium of kcot, dc and rc cases table 3: case distribution of odontogenic cysts according to expression pattern of cyclin d1 expression pattern lesions kcot (12) dc(4) rc(3) diffuse 4(33.33%) 2(50%) 2(66.66%) focal 8(66.67%) 2(50%) 1(33.33%) test x2=1.162; p-value=0.558(ns) table 4: case distribution of odontogenic cysts according to staining intensity of cyclin d1 scores lesions kcot 14 dc 8 rc 8 0 2 (14.29%) 4(50%) 5(62.5%) 1 0(0%) 3(37.5%) 0(0%) 2 6 (42.86%) 1 (12.5%) 3 (37.5%) 3 6(42.86%) 0(0%) 0(0%) test chi square=20.328 ; p-value= 0.001(hs) staining intensity lesions kcot (12) dc(4) rc(3) mild 1(8.33%) 1(25%) 1(33.33%) moderate 4(33.33%) 3(75%) 2(66.66%) strong 7(58.33%) 0(0%) 0(0%) test x2 =7.485 ; p-value = 0.054(ns) j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 95 table 5:case distribution of odontogenic cysts according to staining localization of cyclin d1 staining localization lesions kcot(12) dc(4) rc(3) all layer 0 1 0 (0%) (100%) (0%) basal and/or parabasal 2 1 1 (50%) (25%) (25%) parabasal 9 2 2 (69.2%) (15.4%) (15.4%) parabasal and superfacial layer 1 0 0 (100%) (0%) (0%) test x2 =4.963; p-value= 0.588(ns) table 6: cyclin d1 score distribution in the connective tissue capsule of kcot, dc and rc cases scores lesions kcot(14) dc(8) rc(8) 0 3(21.43%) 3(37.5%) 4(50%) 1 1(7.14%) 3(37.5%) 3(37.5%) 2 7 (50%) 2(25%) 1(12.5%) 3 3(21.43%) 0(0%) 0(0%) test x2 =10.056 ; p-value=0.067(ns) figure 1: keratocystic odontogenic tumor: cyclin d1 ihc expression of cystic epithelium with strong intensity and focally pattern with immunoreactivity in basal and parabasal layer x400. figure 2: dentigerous cyst: cyclin d1 ihc expression of cystic epithelium with moderate intensity and focally pattern with immunoreactivity in basal and parabasal layer x400. figure 3: radicular cyst: cyclin d1 ihc expression of cystic epithelium with moderate intensity and focally pattern with immunoreactivity in basal layer x400. figure 4: keratocystic odontogenic tumor: cyclin d1 ihc expression of the connective tissue capsule x400. figure 5: dentigerous cyst: cyclin d1 ihc expression of the connective tissue capsule x400. figure 6: radicular cyst: cyclin d1 ihc expression of the connective tissue capsule x400. j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 96 discussion the transition between different cell cycle stages is regulated at several checkpoints. regulation of the g1-s transition is controlled by the rb pathway proteins, which include, among others, the cyclin d1 gene. the over expression of this protein shows accelerated g1 progression entering in the s-phase of cell cycle. cyclin d1 may play an important role in tumorigenesis and it has been detected in malignant tumors but also in benign neoplasms (16). in the present study, 12 of 14(85.7%) cases of keratocystic odontogenic tumor, 4 of 8 of dentigerous cysts (75%) and 3 of 8 of radicular cysts(62.5%) cases showed positive immunoreactivity to cyclin d1. this is in line with many studies (15-17). in their study de vicente et al., cyclin d1 was found in 91% of kcots, and the rate of its expression was significantly higher than that of dc (50%), rc (40%). they observed the cyclin d1 expression in a focal and basal pattern, while in dcs and in rcs focal and diffuse patterns were equally observed. the staining pattern was only diffuse. razavi et al. found in their study the expression of cyclin d1 in the suprabasal layers of kcots was significantly higher than in the basal and superficial layers (p < 0.001). taghavi et al. observed a decreased staining positivity for cyclin d1 in the following order: kcots (87%), gocs (60%), rcs (30%), and dcs (25%). it was detected mostly in the parabasal layer of all cysts types. kimi et al. investigated immunohistochemical expression of cyclin d1 and p16 in sporadic, recurrent and syndromic kcots. similar to the present study, cyclin d1 was detected in parabasal layer of kcots with higher expression in syndromic kcots. lo muzio et al., (18) compared cyclin d1 expression in sporadic kcots and kcots associated with gorlin syndrome. on the contrary, they observed cyclin d1 expression just in syndromic kcots not in sporadic ones. the discrepancy between findings may be due to various laboratory methods and used antibody. evaluation of staining pattern and intensity in the present study showed no significant difference among groups. this result is in agreement with de vicente et al., (16) who examined cyclin d1 expression in okcs in comparison with other lesions including ameloblastoma. in most kcots, cyclin d1 was detected in parabasal layer and in consistent with other studies (1,15,16). these results may imply different proliferative activity in the epithelial layers in each group. besides, it can justify the aggressive behavior of kcots. the increased cellular proliferation in the suprabasal layer of the kcots may suggest an abnormal cell cycle control. this unusual pattern of proliferation in the kcots lining is also thought to represent an epithelial disorganisation similar to dysplasia of oral squamous epithelium in premalignant lesions of the oral mucosa, whereby proliferating cells are found in greater numbers in the suprabasal compartment (19-22). the high proliferative potential of the kcots also reinforces its classification as a benign cystic odontogenic neoplasm (23). till the time of the present study, there was no study in the literature established to examine cyclin d1 expressions in connective tissue cells of kcots, dc and rc, so the present study is important to compare connective tissue cells of kcots, dc and rc. there was emphasis in research which concentrated on the epithelium itself, only a few studies have investigated non-epithelial factors i.e. underlying connective tissue stroma that could contribute to the variable biological behavior of the different types of odontogenic cysts and tumors and needs more investigation. hirsberg et al., (24) made a study on the kcots connective tissue. they revealed that stroma not only plays a supporting structure role, but also has an important role in its neoplastic behavior. in the present study, 11 of 14(78.57%) cases of kcots, 5 of 8 of dc (62.5%) and 4 of 8 of rc (50%) cases showed positive immunoreactivity to cyclin d1 in stroma. so positive connective tissue cells for cyclin d1 were recognized exclusively in kcots, whereas other two groups expressed very low cyclin d1 positive cells in their stroma. this reflects the intrinsic growth potential of kcots which was different from other cysts and the stroma played a role in their aggressive behavior. tekkeşi̇n et al.,(25) showed that positive connective tissue cells for ki-67 were recognized exclusively in rc, whereas kcots and ab expressed very low ki-67 positive cells in their stroma. (p<0.01, p<0.09, respectively) there was no significant difference in the ki-67 expression between connective tissue cells of kcots and ab. as explanation of their study these features may suggest that heavy subepithelial chronic inflammation of rc can stimulate proliferation of fibroblasts and endothelial cells. regarding ki-67 as a proliferation markers used in this study, this study disagreed with results of the present study in regarding kcots and rc. the reasons of this discrepancy may be 1st difference in markers used, 2nd limited number of sample in the present study. j bagh college dentistry vol. 28(1), march 2016 a comparative oral diagnosis 97 the results of this study propose that high expression rate of cyclin d1 might be one of the reasons for aggressive behavior of keratocystic odontogenic tumor and high recurrence rate. references 1. taghavi n, modabbernia s, akbarzadeh a, sajjadi s. cyclin d1 expression in odontogenic cysts. turk patoloji derg 2013; 29(2):101-7. 2. da silva ta, batista ac, mendonça ef, leles cr, fukada s, cunha fq. comparative expression of rank, rankl, and opg in keratocystic odontogenic tumors, ameloblastomas, and dentigerous cysts. oral surg oral med oral pathol oral radiol endod 2008; 105: 333-41. 3. neville bw, damn dd, allen cm, bouquot je. oral and maxillofacial pathology. 3rd ed. china: saunders elsevier; 2009. 679-700. 4. wang xx, zhang j, wei fc. familial multiple odontogenic keratocysts j dent child (chic). 2007; 74(2):140-2. 5. regezi ja, scibubba jj, jordan k. oral pathology, clinical pathologic correlation. 6th ed. philadelphia: saunders co; 2012. 246-9. 6. shear m, speight p. cysts of the oral and maxillofacial regions. odontogenic keratocyst. 4th ed., 2007: 6-58. 7. gnepp d. diagnostic surgical pathology of the head and neck. 2nd ed. china: saunders; 2009. 434-530. 8. regezi ja. odontogenic cysts, odontogenic tumors, fibroosseous, and giant cell lesions of the jaws. mod pathol 2002; 15: 331-41. 9. rosai j, ackerman lv. rosai and ackerman's surgical pathology. 10th ed. usa: mosby; 2011. 10. kumamoto h. molecular pathology of odontogenic tumors. j oral pathol med 2006; 35: 65–74. 11. iyengar p, combs tp, shah sj, gouon-evans v, pollard jw, albanese c, flanagan l, tenniswood mp, guha c, lisanti mp, pestell rg, scherer pe. adipocyte secreted factors synergistically promote mammary tumorigenesis through induction of antiapoptotic transcriptional programs and protocncogene stabilization. oncogene 2003; 22:6408–23 12. beier f, ali z, mok d, taylor ac, leask t, albanese c, pestell rg, luvalle p. tgfβ and pthrp control chondrocyte proliferation by activating cyclin d1 expression. mol biol cell 2001; 12(12): 3852-63. 13. hanai j, dhanabal m, karumanchi sa, albanese c, waterman m, chan b, ramchandran r, pestell r, sukhatme vp. endostatin causes g1 arrest of endothelial cells through inhibition of cyclin d1. j biol chem 2002; 277:16464–9. 14. fu m, wang c, li z, sakamaki t, pestell r g. minireview: cyclin d1: normal and abnormal functions. endocrinol 2004; 145(12):5439-47. 15. kimi k, kumamoto h, ooya k, motegi k. immunohistochemical analysis of cell-cycleand apoptosis-related factors in lining epithelium of odontogenic keratocysts. j oral pathol med 2001; 30: 434-42. 16. de vicente jc, torre-iturraspe a, gutiérrez am, lequericafernández p: immunohistochemical comparative study of odontogenic keratocysts and other odontogenic lesions. med oral patol oral cir bucal 2010; 15: 709-15. 17. razavi sm, poursadeghi h, aminzadeh a. immunohistochemical comparison of cyclin d1 and p16 in odontogenic keratocyst and unicystic ameloblastoma. dent res j (isfahan) 2013; 10(2):180-3. 18. lo muzio l, staibano s, pannone g, bucci p, nocini pf, bucci e, de rosa g. expression of cell cycle and apoptosis-related proteins in sporadic odontogenic keratocysts and odontogenic keratocysts associated with the naevoid basal cell carcinoma syndrome. j dent res 1999; 78(7):1345-53. 19. li tj, brown rm, matthews jb. epithelial cell proliferation in odontogenic keratocysts: a comparative immunocytochemical study of ki-67 in simple, recurrent and basal cell naevus syndrome (bcns)-associated lesions. j oral pathol med. 1995; 24:221-6. 20. gadbail ar, chaudhary m, patil s, gawande m. actual proliferating index and p53 protein expression as prognostic marker in odontogenic cysts. oral dis 2009; 15:490–8. 21. nadalin mr, fregnani er, silva-sousa yt, perez de. syndecan-1 (cd138) and ki-67 expression in odontogenic cystic lesions. braz dent j 2011; 22(3):223-9. 22. gadbail ar, hande a, chaudhary m, nikam a, gawande m, patil s, tekade s, gondivkar s .tumor angiogenesis in keratocystic odontogenic tumor assessed by using cd-105 antigen .j oral pathol med 2011; 40: 263–9. 23. mateus gc, lanza gh, de moura ph, marigo hde a, horta mc. cell proliferation and apoptosis in keratocystic odontogenic tumors. med oral patol oral cir bucal. 2008; 13: e697-702. 24. hirsberg a, sherman s, buchner a, dayan d. collagen fibers in the wall of odontogenic keratocysts: a study with picrosirius red and polarizing microscopy. j oral pathol med. 1999; 28:410-12. 25. tekkeşi̇n m s, mutlu s, olgac v. expressions of bax, bcl-2 and ki-67 in odontogenic keratocysts (keratocystic odontogenic tumor) in comparison with ameloblastomas and radicular cysts. turkish j pathol 2012; 28(1): 49-55. ayam f.doc j bagh college dentistry vol. 25(3), september 2013 root resorption and pedodontics, orthodontics and preventive dentistry134 root resorption and anti-dentine antibody level in serum and saliva of well-controlled type ι diabetic patients undergoing orthodontic treatment ayam a. h. taha, b.d.s., m.sc. (1) esra h. alhashemy, b.sc., m.sc., ph.d. (2) abstract background: diabetic mellitus type ι is a metabolic disorder of diverse etiological factors, characterized by hyperglycemia resulting from an absolute deficiency of insulin affected childhood and adolescent. some of these patients seek an orthodontic care .the orthodontist who is treating these medically compromised patients should have a working knowledge of the multitude of medically complex problems. this information will support and enable for delivery of high standards of dental care in general and orthodontic care in particular. the aim of this study was to analyze serum igg levels and salivary secretory iga (siga) levels in human dentine extract (hde) before (t0) and 6 months after (t6) orthodontic treatment and to correlate anti-hde autoantibodies to root resorption in well-controlled type ι diabetic patients. materials and methods: sixty individuals, who were attending to al-mustansiriya national diabetes center from april to october, 2012 and classified as wellcontrolled type ι diabetic patients (hba1c <8.5), were participating in this study .the mean age of the whole samples was (15±1 sd ) years, thirty three of them(18 males and 15 females) were not wearing orthodontic appliance and were selected as the controls, while twenty seven of them (12 males and 15 females) were wearing orthodontic appliance . periapical radiographs of the upper central incisors , unstimulated saliva and serum samples were obtained of all patients before(t0) and 6 months after(t6) orthodontic treatment. anti-dentine antibody (ab) levels were determined by mean of enzyme linked immune sorbant assay (elisa) technique. at t6, root resorption was classified as grade 0 (no resorption), grade 1 (slight resorption), and grade 2 (moderate to severe resorption). chi square test and ttest were used to assess the association between qualitative and quantitative results respectively ,while paired ttest was used to analyze the results before(t0) and 6 months after(t6) orthodontic treatment. differences were considered significant at p<0.05. results: there was statistical significant difference in the level of (antidentine ab) in saliva between the two study groups at t0 and t6, its level was higher in the wearing group comparing with non wearing group, while it didn’t differ in serum. in the wearing group, the level of anti -dentine antibody in serum and saliva significantly decreased at t6 comparing with its level at t0. high level of the (anti -dentin ab) shown in serum and saliva in grade 1 root resorption (r1) comparing with grade 0 root resorption (r0) at t0 and also at t6. conclusions: the results of this study indicate that the anti -dentin antibody plays an important role in the detection of root resorption during orthodontic treatment in wellcontrolled diabetic patients type ι and its level is different according to the grade of root resorption in both saliva and serum. keywords: diabetes mellitus type ι, anti-dentine antibody, root resorption, orthodontic treatment. (j bagh coll dentistry 2013; 25(3):134-141). introduction insulin dependent diabetic mellitus (iddm) is the most common chronic metabolic autoimmune disease (1). it is characterized by hyperglycemia due to the infiltration of lymphocytes in the pancreas causing destruction of insulin producing beta-cells (2,3). the incidence of (iddm) is reported to be increasing by 3-5% per year, and the number of people with diabetes is estimated to reach 380 million by 2025(4).the major cause of (iddm) is attributed to changes in their habitual lifestyle represents a major clinical and public health problem (5,6) . some of these diabetic patients for a reason or another seek an orthodontic treatment which is not restricted only for healthy patients (7). (1)assistant lecturer, department of pedodontics, orthodontics and preventive dentistry/ college of dentistry/al-mustansiriya university. (2)lecturer, department of basic sciences / college of dentistry/al-mustansiriya university. the orthodontic treatment is a discipline in dentistry, like many other disciplines in this field; it can have adverse effects associated with the execution of treatment. these effects can be related to the patient or practitioner. some of these effects are not fully understood, such as root resorption, and others are associated with orthodontic treatment without supporting evidence (8). consideration of risk factors prior to treatment is important, because dental resorptions constitute a challenge to dentistry due to their organic complexity. the concern and curiosity on this subject are not recent. the oldest report about resorptions of the dental structures was described by michael blum in 1530, probably the first book about the topic. however, the scientific study of root resorptions is considered recent, embracing nearly two decades (9). numerous potential factors, related to both the individual patient and to treatment, have been suggested as risk factors for root resorption, but j bagh college dentistry vol. 25(3), september 2013 root resorption and pedodontics, orthodontics and preventive dentistry135 direct causal factors have not been identified (10). the degree of resorption can be very variable, highlighting the importance of individual susceptibility over and above other risk factors (11). it was hypothesized that susceptibility to root resorption may be associated with autoimmune responses against dentine matrix proteins, based on evidence that anti-dentine antibodies could be detected in experimental root lesions in mice and in traumatized patients with root resorption (12-14). autoimmune responses can influence the resorption of calcified tissues through interactions among immune and clast cells or through the production of cytokines and other mediators that modulate local inflammatory responses (15,16). orthodontic forces induce an inflammatory cell infiltration on periodontal tissues that produce signals and cytokines for differentiation and activation of clast cells (13,17-21). the chronic inflammatory process may aid the presentation of autoantigens to the immune system and the breakdown of immunological tolerance (22,23). migration of immunocompetent cells to the periodontal ligament, such as lymphocytes, plasma cells, and antigen-presenting cells (macrophages and dendritic cells), has been reported during orthodontic movement (24,25). in patients with pathological root resorption, the presence of antibodies against dentine antigens, increased serum igg, and low levels of igm suggests that an autoimmune reaction is present (14). secretory iga (siga) is the main line of defence of the oral cavity and upper respiratory tract surfaces and is secreted in large amounts into saliva by the salivary glands (22,23,26,27). siga represents the local response of adaptative immune systems to environmental antigens found in the digestive and upper respiratory tract (26,28,29). alterations of the salivary levels of siga autoantibodies may represent a local imbalance of the immune response in the oral cavity (30). autoantibodies (siga) can be detected in saliva samples of patients with autoimmune diseases (3134). currently, information is available concerning the presence of autoantibodies in the saliva of patients with orthodontic root resorption. salivary antibodies may be a more suitable approach to study oral pathological disorders since they represent the local immune response, are a noninvasive method, and can be easily sampled (35). materials and methods the sample: the sample of this study had been selected from patients who were attending to almustansiriya national diabetes center from april,2012 till october, 2012.before starting the study an approval was obtained and the objective of the study was explained to the parents of each participant. the sample consist of sixty wellcontrolled type ι diabetic patients with mean age (15±1 sd) years ,of certain criteria ,thirty three of them(18 males and 15 females) were not undergoing orthodontic treatment and were selected as the controls, while twenty seven of them (12 males and 15 females)who had class ι malocclusion (crowding in the upper anterior teeth need to be treated without premolar extraction) were undergoing orthodontic treatment by using straight wire fixed orthodontic appliances with 0.018×0.025 inch bracket slots .the degree of upper central incisor root resorption , anti-hde igg and anti-hde siga levels were analyzed in the saliva and serum of all patients before(t0) and 6 months after(t6) orthodontic treatment. the inclusion criteria: certain points were considered in the selection of the sample. 1the participants were classified as well controlled type ι diabetic patients (hba1c <8.5) with no history of other autoimmune diseases or chronic inflammatory diseases. 2none of the patients or controls reported previous trauma of permanent dentition . 3the participants didn’t use steroidal and nonsteroidal anti –inflammatory drugs for at least one month before sampling. 4no history of previous orthodontic treatment. 5the patients didn’t show clinical or radiographic signs of periodontal diseases,periapical lesions, or root resorption before starting this study . 6patients with active caries or oral mucosa lesions were excluded. 7presence of only permanent dentition. blood sample: after an overnight fast,(5 ml) of blood samples were collected from well-controlled type ι diabetic patients of both groups by venipuncture between 8.30 a.m. and 10.30 a.m., allowed to clot ,then these blood samples centrifuged at 30 rpm for 10 minutes to obtain serum samples to asses fbs(fasting blood sugar level) and hba1c (glycoslyted hemoglobulin)and then stored at 20˚c until using for detection of anti-hde igg level. saliva sample: unstimulated whole saliva (2ml) were collected from patients of both groups by expectoration into sterilized vials after they rinsed j bagh college dentistry vol. 25(3), september 2013 root resorption and pedodontics, orthodontics and preventive dentistry136 their mouth twice with water to avoid the effect of the circadian cycle of cortisol on secreted siga into saliva because the amount of secreted siga into saliva is decreased during early morning by cortisol variation (36) ,samples were obtained between 10.00 a.m. and 4.00 p.m., then saliva sample were centrifuged at 12000 rpm for 10 minutes and the supernatants were stored at -20˚c until use. radiographs: periapical radiographs were obtained for all patients at t0 and t6.the radiographs (70 kv,10 ma, exposure time 0.7 seconds) of the upper central incisors were taken using the long cone paralleling technique.the most resorbed incisor was considered for analysis .the degree of root resorption was classified using the criteria described by malmgren et al. (37). tooth length was measured from the incisal edge to the apex. root and crown length was measured from the incisal edge to the apex using cemento-enamel junction as the limit. image distortion was determined by comparing the image length to the real length of a radiopaque object placed on the film. image distortion between t0 and t6 radiographs was determined by comparing crown length .the maximum acceptable distortion was 5%. root resorption was graded from 0 to 2, where 0=no discernible root resorption; 1=slight root resorption (less than 2mm); 2 moderate to severe resorption (more than or equal to 2 mm). laboratory investigation: serum antidentin ab was measured by using elisa (enzyme linked immune sorbant assay) technique by procedure of the test as follows: 1-antigen preparation: the human dentin extract (hde) which containing the organic materials of the dentin extract, was used as antigen. hde was obtained was obtained through a modification of the technique described by bradford (38), using third molars donated by patients in which extractions were indicated .the dentin was drilled out using a high speed bit .the precipitate was placed in a demineralizing solution diluted 1:1(guanidinehcl 5 m, 10 percent enzymelinked immunosorbant assay (edta),5 µm phenylmetilsulfonylflouride, ph 5.0)for 14 days at 4˚c and then centrifuged at 12000 rpm for 20 minutes (here z 323k/germany). the supernatant was dialyzed overnight against phosphate-buffered saline (pbs; ph 7.2) at 4˚c.protein concentration (ranging from 300 to 400µg/ml) was determined . hde was stored at 20˚c until use. this procedure was done in institute of molecular biotechnology and genetic engineering for postgraduate study at baghdad university. 2determination of protein concentration: protein concentration was carried out using the method of bradford(1976)and standard curve bovine serum albumin was done using different concentration , each one was pipetted in duplicated sterilized test tubes ,then protein concentrations were measured using the method of bradford(1976) and then read the optical density(o.d) .the absorbency was plotted against the corresponding concentration of bovine serum albumin. 3elisa for detection of serum anti-hde igg: astandards concentration was constituted to 100ng/ml. (5,10,15,20,25)ng/ml. bhde (100µg/ml)in carbonate-bicarbonate buffer (na2co3 1.59g, nahco3 2.93g, distilled water qsp1000ml,ph 9.6)was used to coat 96 –well immunoplates for 1 hour at 37˚c and then stored overnight at 4˚c . cthe plates were washed four times with pbs containing 0.05 percent tween 20(pbs-t) blocked with pbs –t-5 percent skimmed milk for 1 hour at room temperature. dafter washing , the serum sample (1/10 in pbs),were incubated at 37 ˚c for 1 hour, then washed four times ,incubated with goat anti-human igg labeled with peroxidase ( sigma-aldrich ,st louis, usa)diluted 1:4000 at 37˚c for 1 hour . ethe substrate solution (100µl), after washing, was added (5 mg orthophenylenediamine , 10ml of 0.1m citrate buffer, ph 4.5,and 5 µl h2o2). fthe reaction was stopped after 15 minutes with 50 µl h2so44n and the absorbance was read in elisa reader at 492nm (biotek , usa) at immunnology unit/ alkaramh teaching hospital . 4elisa for detection of salivary anti-hde iga: by using (elisa test) started by sensitizing and blocking the immunoplates as described before, followed by washing, then 100 µl from undiluted saliva samples were added and incubated at 37˚c for 2 hours, then rewashed ,and 100 µl of mouse monoclonal igg to human secretory chain(sigma-aldrich, ,st louis, usa)were added for each well and incubated at 37˚c for 2 hour after preparation of the dilution 1/4000. after washing the plate wells, 100µl from goat anti –mouse igg labeled with peroxidase (sigma-aldrich,st louis, usa) were added for each well and incubated for 1 hour at 37˚c , then stopped the reaction and the absorbance was read. j bagh college dentistry vol. 25(3), september 2013 root resorption and pedodontics, orthodontics and preventive dentistry137 statistical analysis the data were entered and analyzed on spss version-20, and were summarized using frequency and proportions. chi-square test , t-test and paired t-test were used for assessing significance of association .p-value of equal or less than 0.05 was used as the level of significance (39,40) . results the results of this study show that there was no significant difference between the two study groups according to gender and age which were classified as : wearing orthodontic appliance group includes 44.4% male and 55.6% female and non –wearing orthodontic appliance (control) group which includes 54.5% male and 45.5% female as seen in table 1. the results also showed that 33.3% of wearing group develops grade r1 of root resorption with significant statistical differences by chisquare test (p value 0.05).table 2. regarding the level of antidentine ab in serum, it was reported that there was no significant difference between wearing and non wearing (control) groups at t0 and t6 seen in table 3, while there was statistical significant difference in anti-dentine ab level in saliva between the two study groups, where the mean level of antibody was higher in the wearing group comparing with non wearing group at t0 and t6 (p value=0.059,0.02 respectively) as seen in table 4. in the wearing orthodontic appliance group, the concentration of anti-hde in serum and saliva showed statistical significant differences between t0 and after 6 months (t6) of wearing orthodontic appliance (p value=0.02) as shown in table 5, where the level of anti –hde igg was at t6 (20.222) which is less than that at t0 (22.422) and the level of anti–hde siga was at t6 (21.181) which also less than that at t0 (23.356). it can be also seen high statistical significant differences in the concentration of anti-dentine ab in serum between r0 and r1 at t0 and t6, in which the result revealed, increased the serum level of antibody in (r1) in wearing group as seen in table 6. the results also demonstrated high significant difference regarding the level of anti-dentine ab in saliva in wearing group between (r0)and (r 1) at zero time, and also at t6 (after 6 months of wearing the orthodontic appliance) which is also more in (r1 ) than in ( r0) at two different times with (p value=0.002) seen in table 7. discussion external root resorption is a phenomenon that has been associated with orthodontic treatment. there are numerous potential factors, related to both the individual patient and to treatment, have been suggested as risk factors for root resorption ; therefore, it is a multifactorial occurrence and can be detected early during orthodontic treatment, after 6 months of force application (41-45).the susceptibility to root resorption may be associated with autoimmune responses against dentine matrix protein , based on evidence that antidentine antibodies could be detected in experimental root lesions in mice and in traumatized patients with root resorption (12-14). the presence of autoantibodies may not cause root resorption ,where as autoimmune aggression occurs when the tissue antigen are accessible to specific receptors of the immune system and there are costimulatory stimuli (46) .during orthodontic treatment ,the compression areas and hyaline necrosis in the periodontium may damage the cementum layer and expose the dentine matrix (13). the resulting inflammation caused by damaged periodontal tissue can result in recruitment of antigen –presenting cells (47) and can also induce the expression of costimulatory molecules that favor lymphocyte activation (25) which are the primary cells of the immunologic system, and developed one of the most sophisticated defense mechanisms in the biological system (48); therefore, the levels of antidentine antibody in saliva and serum can be detected and they were higher in patients who were wearing orthodontic appliances comparing with nonwearing group. the anti-dentine antibodies can be also detected in the patients who were not undergoing orthodontic treatment because the organic matrix of dentine shares common components with bone matrix protein, especially type ι collagen ,as well as non collagenous proteins and serum components(49). there is an evidence demonstrated that some proteins considered exclusively expressed by odontoblasts ,such as cleavage products of dentine sialophosphoprotein , are now known to be expressed in periodontium and bone (50,51).the mean concentration of some of these dentine protein (dentine matrix protein 1,dentine sialoprotein, and dentine phosphoprotein)is higher in the dentine matrix (50,52) .for this reason ,the emergence of antidentine antibodies could be caused by several factors, such as periodontal or root damage or oral inflammatory processes, thus the level of antidentine antibody is high in saliva and serum of j bagh college dentistry vol. 25(3), september 2013 root resorption and pedodontics, orthodontics and preventive dentistry138 well-controlled type ι diabetic patients who were wearing orthodontic appliances and suffering from root resorption grade 1 (r1) at t6 comparing with patients who were also wearing orthodontic appliances but didn’t suffer from root resorption (r0). the resorption of mineralized tissues by clast cells is influenced by cytokines and costimulatory molecules produced by lymphocytes (15,16) .the present results suggest that a local and systemic immunomodulation of specific b lymphocytes to dentine may occur during orthodontic treatment. the modulation of t and b lymphocyte responses has been observed in other inflammatory diseases where clasts play a pivotal role, and this phenomenon induces bone destruction (15,16). some inflammatory cytokines of the innate immune response ,which induced by orthodontic force, may affect the production and delivery of siga on the mucosal surface such as tumour necrosis factor–alpha(tnfα) and interleukine-1 (il-1) (19,46,53,54) .both can stimulate siga transposition throughout the epithelial barriers and stimulate clast differentiation and activation (15,55) ,thus the level of anti-hde siga was increased in the wearing group comparing with non-wearing at t6 (after 6 months orthodontic treatment) .however, patients with significant degree of root resorption cannot maintain increased levels of siga during the application of orthodontic force suggesting that local anti-hde antibody production was not exclusively supported by unspecific inflammatory responses54, since it excluded from the beginning such as periodontal diseases, caries and trauma ;therefore, the level of anti-hde siga was decreasing at t6 comparing with its level at t0 in the wearing group who suffering from root resorption grade1 (r1) .these findings agreed with solange et al. (35) in healthy patients undergoing orthodontic treatment with root resorption grade 2 (r2) . the level of anti-hde igg was also found decrease at t6 comparing with the same wearing group at t0 who suffering from root resorption grade 1(r1), suggesting that the formation of immunocomplexes may be responsible for such a difference, and this is agreed with the experiments were done in mice by wheeler and stroup (12),and in traumatized patients with root resorption by hidalgo et al. (14). these findings also agreed with solange et al. (35) in healthy patients undergoing orthodontic treatment with root resorption grade 2 (r2). the level of anti-hde antibody in serum and saliva of well-controlled type ι diabetic patients was higher in patients from the beginning of orthodontic treatment who later showed root resorption after 6 months of treatment. these findings suggest that analysis of serum igg antihde and saliva siga anti-hde before starting orthodontic treatment are preferable to give an idea about the susceptibility of these patients to develop root resorption after wearing orthodontic appliance in the future. references 1. shulman rm, daneman d .type 1 diabetes mellitus in childhood. medicine 2010; 38: 679-85. 2. atkinson ma, maclaren n. the pathogenesis of insulin –dependent diabetes mellitus. n engl j med 1994; 33: 1428-36. 3. waldron –lynch f, herold kc. immunomodulatory therapy to preserve pancreatic β-cell function in type 1 diabetes. nat rev drug discov 2011; 10: 439-52. 4. international diabetic federation. diabetic atlas. 3rd. brussels: international diabetic federation 2006. 5. abduljabbar ma, aljubeh jm, amalraj a, cherian mp. incidence trends of childhood type ι diabetes in eastern saudi arabia. saudi med j 2010; 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7(2). 49. qin c, et al. a comparative study of sialic acidrich proteins in rat bone and dentine. eur j oral sci 2001; 109: 133-41. 50. qin c et al. the expression of dentine sialoprotein gene in bone. j dent res 2002; 81: 392-4. 51. baba o, et al. detection of dentin sialoprotein in rat periodontium. eur j oral sci 2004;112:163-70. 52. qin c, brunn jc, cadena e, ridall a, butler wt. dentin sialoprotein in bone and dentin sialoprotein gene expressed by osteoblasts. connective tissue res 2003; 44: 179-83. 53. blesta a, berggreen e, brudvik p. interleukin -1 alpha and tumor necrosis factor –alpha expression during the early phases of orthodontic tooth movement in rats. eur j oral sci 2006; 114: 423-9. 54. maeda a, et al. force induced il-8 from periodontal ligament cells requires il-1beta. j dent res 2007; 86: 629-34. 55. liu d y, wang x l, liu p. tumor necrosis factor – alpha upregulates the expression of immunoglobulin j bagh college dentistry vol. 25(3), september 2013 root resorption and pedodontics, orthodontics and preventive dentistry140 secretory component. j investig allergol clin 2007; 17: 101-6. table 1. distribution of study groups according to gender and age variables non-wearing (control) wearing (study group) comparison no. % no. % p-value male 18 54.50% 12 44.40% ns female 15 45.50% 15 55.60% total 33 100% 27 100% age (year) 15±1sd 15±1sd ns sd=standard deviation, ns=non significant table 2. distribution of study groups according to root resorption. groups no. and % grades total comparison r0 r1 chi square p-value wearing no. 18 9 27 12.94 hs % within wearing/ non-wearing 66.7 33.3 100 % of total 30 15 45 non-wearing no. 33 0 33 % within wearing/ non-wearing 100 0 100 % of total 55 0 55 total no. 51 9 60 % within wearing/ non-wearing 85 15 100 % of total 85 15 100 table 3. mean of anti-dentine antibody level of study groups in serum at two different time. conc. of anti-hde ab wearing/ not wearing no. mean s.d. t-test pvalue t0 wearing 27 22.42 8.25 1.7 0.09 nonwearing 33 19.23 5.69 t6 wearing 27 20.22 5.34 0.822 0.4 nonwearing 33 19.22 4.08 table 4. mean of antibody in saliva for wearing and non-wearing at two different time. conc. of anti-hde ab wearing/not wearing no. mean s.d. t-test pvalue t0 wearing 27 23.35 7.91 1.929 0.059 not wearing 33 19.82 6.27 t6 wearing 27 21.18 4.99 2.261 *0.02 not wearing 33 18.50 3.96 *hs: highly significant difference table 5. concentration of anti-dentine antibody in serum and saliva of wearing group at different times. anti-dentine antibody no. mean s.d. t-test pvalue conc. in serum t0 27 22.422 8.2509 2.420 * 0.02 t6 27 20.222 5.3448 conc. in saliva t0 27 23.356 7.9135 2.338 * 0.02 t6 27 21.181 4.9973 j bagh college dentistry vol. 25(3), september 2013 root resorption and pedodontics, orthodontics and preventive dentistry141 table 6. mean of anti-dentine antibody level in serum of two grades at two different times in wearing group table 7. mean of antibody level in saliva of two grades of root resorption at two different times in wearing group. conc . of anti-hde ab level in saliva root resorption grade no. mean s.d. t-test pvalue t0 r 0 18 18.772 4.8149 -7.578 hs r 1 9 32.522 3.5309 t6 r 0 18 19.222 3.7217 -3.424 0.002 r 1 9 25.100 5.0811 conc. of anti-hde in serum root resorption grade no. mean s.d. t-test pvalue t0 r 0 18 17.989 4.8475 -6.119 hs r 1 9 31.289 6.2170 t6 r 0 18 18.378 4.1098 -2.866 0.008 r 1 9 23.911 5.8298 nagham f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 estimation of 140pedodontics, orthodontics and preventive dentistry estimation of some salivary variables and oral health status of patients with chronic myeloid leukemia aged 45-55 years nagham h. al-shaikh radhi, b.d.s. (1) athraa m. al-waheb, b.d.s, m.sc. (2) abstract background: chronic myeloid leukemia is a cancer of the white blood cells characterized by the increased and unregulated growth of predominantly myeloid cells in the bone marrow. this study aimed to determine the effect of chronic myeloid leukemia on dental caries and oral health status including gingivitis, loss of attachment, plaque index and calculus index as well as evaluation of salivary flow rate and salivary interleukins-6 and tumor necrosis factor-α. material and methods: study group consisted of (75) subjects, (25) were newly diagnosed with chronic myeloid leukemia, (25) were taking medications (glevic), and (25) were control subjects, all aged 45-55 years old. collection of stimulated salivary samples was performed under standard conditions, then salivary flow rate and salivary cytokines estimation was done. clinical examination and oral health assessment were carried out under the standardized conditions of oral health surveys of world health organization. dental plaque was scored according to the criteria of plaque index by silness and loe(1964), dental calculus was scored following the criteria of calculus component of the periodontal index (ramfjord, 1959), assessment of gingival health done according to the criteria of gingival index for loe and silness (1963) and loss of attachment done following the criteria of who (1997). caries assessment was done according to the who modified decayed-missing-filled index (dmf) and examination was done with a plane mouth mirror and cpi probe. results: dmfs index were higher in the newly diagnosed group followed by the control group and then the treated group but the lsd test showed that differences were statistically not significant between each two groups, plaque index was higher in the newly diagnosed group, and the differences were statistically significant only between the newly and the control group (p<0.05), calculus index was higher in the newly diagnosed group and the difference was statistically significant between the newly diagnosed group and the treated group. gingival index was higher in the control group and the difference was statistically highly significant between the new and control groups (p<0.01) and also highly significant between control group and the treated group. loss of attachment index was higher in the control group the lsd test show that the difference was statistically significant between the control group and each one of the other two groups. in regard to saliva, salivary flow rate was higher in the control group; the difference was significant between the control and the newly diagnosed group and highly significant between control and the treated group. interleukin-6 level was higher in the newly diagnosed group then the treated group then the control group. lsd test show that the difference was statistically significant between the new and the treated group (p<0.05) and it was highly significant between the new and the control group (p<0.01) but it was not significant between the treated and control group. tnf-α level was higher in newly diagnosed group followed by the treated group then the control group and the difference was statistically significant with the treated group and highly significant with the control group, but the difference was not significant between the treated and the control group. conclusion: salivary interluekine-6 and tumor necrosis factorα levels were higher in the newly diagnosed group. saliva provides an ideal tool for the detection of pro-inflammatory markers. salivary il-6and tnf-α may play an important role as biomarkers for cmland il-6 is more predictable for the response to the treatment than tnf-α. key words: chronic myeloid leukemia, myeloid cells, glevic, salivary cytokines. (j bagh coll dentistry 2013; 25(special issue 1):140-145). الخالصة ، فقدان التھاب اللثة بما في ذلكصحة الفم على تسوس األسنان وابیضاض الدم النقیاني تحدید تأثیر :األھداف من الدراسة .ھو سرطان خالیا الدم البیضاء ، یتمیز بزیادة و عدم انتظام نمو أغلب الخالیا النخاعیة في نخاع العظم ، مرض ابیضاض الدم النقیاني:المقدمة ) .ألفا عامل النخر الورميو 6 األنترلوكین( العوامل المناعیةمعدل تدفق اللعاب و، و تقییم الترسبات الكلسیة مؤشرو صفیحة الجرثومیةال مؤشر ، ةالتصاق األسنان باللث تم جمع عینات من اللعاب المحفز ، . سنة 55و 45تتراوح أعمارھم ما بین .مشارك سلیم25و،) glivec( منھم كان یتم عالجھم بالمستحضر 25ابیضاض الدم النقیاني و نھم كانوا مشخصین حدیثا بمرض م 25، ) امشارك 75( شملت الدراسة :المواد و الطرائق و تقییم صحة الفم حسب الظروف القیاسیة الخاصة بمسح ألسریريتم أجراء الفحص كما و .في اللعاب ، و بعدھا تم تقییم معدل تدفق اللعاب و تركیز االنترلوكین )tenovuo & lagerlof, 1996( من قبل المذكورة اإلرشاداتحسب الظروف القیاسیة ، بأتباع ,ramfjord( أمراض ما حول اللثة تم قیاس الترسبات الكلسیة الفمویة حسب مواصفات مؤشر . )silness and loe, 1964(ب طریقة حس الصفیحة الجرثومیةتبعا لمواصفات مؤشر الصفیحة الجرثومیةتم قیاس ) . 1997منظمة الصحة العالمیة ( صحة الفم دالة تسوس األسنان (تم تقییم تسوس األسنان حسب مواصفات منظمة الصحة العالمیة ، كما و 1997، كما و تم تقییم فقدان االلتصاق حسب مواصفات منظمة الصحة العالمیة ) loe and silness, 1963(تم تقییم صحة اللثة حسب مواصفات مؤشر اللثة . )1959 ) .الدائمیة المعدل . اتبین المجموع كانت الفروقات غیر معنویھو ) 22.20±4.29( المرضى المعالجین وتلیھم مجموعة) 25.96±2.27( الضابطةمجموعة الو تلیھم ) 27.20±5.02(كان أعلى في مجموعة المرضى المشخصین حدیثا مؤشر تسوس سطوح األسنان الدائمیة :ألنتائج كان أعلى في مجموعة فیحات الجرثومیةصشر المؤ . )p< 0.05(الضابطة المرضى المشخصین حدیثا و مجموعة تيو الفروقات كانت ذات داللة إحصائیة بین مجموع ) 1.56±0.11( شر الترسبات الكلسیة كان أعلى في مجموعة المرضى المشخصین حدیثاؤم ة عالیةو الفرو قات كانت ذات داللة إحصائی) 0.49±0.06( الضابطةمجموعة الكان أعلى في التھاب اللثة .المرضى المعالجین المرضى المشخصین حدیثا و مجموعة تيو الفروقات كانت ذات داللة إحصائیة بین مجموع) 0.32±0.06(المرضى المشخصین حدیثا و الفرو قات الضابطةمجموعة المؤشر فقدان االلتصاق كان أعلى في .)p< 0.01( الضابطةمجموعة الو الفروقات كانت ذات داللة إحصائیة عالیة بین مجموعة المرضى المعالجین و ) p< 0.01( الضابطةمجموعة البین مجموعة المرضى المشخصین حدیثا و و الفروقات كانت ذات داللة ) 1.96±0.11(الضابطة مجموعة البخصوص اللعاب ، كان معدل تدفق اللعاب أعلى في .و كل من مجموعتي المرضى المشخصین حدیثا و مجموعة المرضى المعالجین ) 0.56±0.10( الضابطةمجموعة الة بین كانت ذات داللة إحصائی أعلى في مجموعة المرضى المشخصین 6المناعي األنترلیوكین نتركیز البروتیكان . لمجموعة الضابطة ، و الفرو قات كانت ذات داللة إحصائیة عالیة بین مجموعتي المرضى المعالجین و ا الضابطةمجموعة الإحصائیة بین مجموعة المرضى المشخصین حدیثا و الفرو قات و ، ) p < 0.05( الفرو قات كانت ذات داللة إحصائیة بین مجموعة المرضى المشخصین حدیثا و مجموعة المرضى المعالجین و ) 56.0±8.33(ابطة و المجموعة الض) 76.86±18.25(و من ثم مجموعة المرضى المعالجین ) 134.20±60( حدیثا الفا عامل النخر الورمي( تركیز البروتین المناعي .المجموعة الضابطة یر ملحوظة بین كل من مجموعتي المرضى المعالجین و و لكن الفرو قات كانت غ ) p < 0.01(الضابطة مجموعة الكانت ذات داللة إحصائیة عالیة بین مجموعة المرضى المشخصین حدیثا و و مجموعة المرضى المرضى المعالجین ةمجموعبین ذات داللة إحصائیة تفرو قاو كانت ال) 88.60±7.82(و المجموعة الضابطة ) 99.40±6.72(و من ثم مجموعة المرضى المعالجین ) 135.20±13.28( أعلى في مجموعة المرضى المشخصین حدیثا) . المرضى المعالجین ةمجموعة الضابطة و مجموعالبین ةالضابطة ، و لكن الفروقات كانت غیر ملحوظمجموعة ال بین مجموعة المرضى المشخصین حدیثا والفرو قات كانت ذات داللة إحصائیة عالیة و ،) p < 0.05(المشخصین حدیثا بالنسبة لمعدل . المشخصین حدیثا ، بینما ألتھاب اللثة و فقدان االلتصاق كانا أعلى في المجموعة الضابطة الصفیحة الجرثومیة و الترسبات الكلسیة كانت أعلى في مجموعة المرضى. ال توجد فروقات إحصائیة في حالة تسوس األسنان بین المجامیع الثالثة :االستنتاجات ال توجد فروقات معنویھ بین الرجال و . رة ملحوظة في مجموعة المرضى المشخصین حدیثافقد كانا أعلى بصو ) الفا عامل النخر الورمي( البروتین المناعي و 6البروتین المناعي األنترلیوكین تدفق اللعاب فقد كان أعلى في المجموعة الضابطة ، و مستوى تركیز .في مجموعة المشخصین حدیثا والمجموعھ الضابطھ و كذلك مؤشر الصفیحھ الجرثومیھ في المجموعھ المعالجھ) 6االنترلوكین(النساء في جمیع المتغیرات ما عدا العامل المناعي introduction leukemia is a slowly progressing cancer that starts in blood-forming cells of the bone marrow. (1)m.sc. student, department of pedodontic and preventive dentistry, dental college, university of baghdad. (2)professor, department of pedodontic and preventive dentistry, dental college, university of baghdad. leukemia cells are the result of an abnormal development of leukocytes (white blood cells) and their precursors. these cells look different than normal cells and do not function properly(1).there are four main types of leukemia, which can be further divided into subtypes. for classifying j bagh college dentistry vol. 25(special issue 1), june 2013 estimation of 141pedodontics, orthodontics and preventive dentistry leukemia, the first steps are to determine whether the cancer is lymphocytic or myelogenous, (cancer can occur in either the lymphoid or myeloid white blood cells) and whether it is acute or chronic (rapidly or slowly progressing) (2). chronic leukemia cells live much longer than normal white blood cells, resulting in an accumulation of too many mature granulocytes or lymphocytes. chronic leukemia progresses slowly but can develop into an acute form. major types include chronic lymphocytic leukemia (cll) and chronic myelocytic leukemia (cml) (3). chronic myelomonocytic leukemia is a chronic, slowly progressing form characterized by malignant monocytes and myeloblasts, splenomegaly, and thrombocytopenia. based on clinical characteristics and laboratory findings cml is divided in to three phases: chronic phase, accelerated phase and blast crises phase (4).cml patients usually have a tendency to bleed and high risk of getting infection. regarding to oral health, a number of scientific studies were carried out to determine the relation between cml and oral health status (dental caries and periodontitis) (5, 6). material and methods in this study the sample was consisting of study group (50 patients) with confirmed diagnosis of the disease (cml), 25 of them were newly diagnosed and 25 of them were taking medications which were derivative of 2 phenylaminopyrimidine, (glevic), for more than one year; and they were examined in baghdad teaching hospital. in comparison with control group consisting of (25 subject). the samples (both study and control) were aged (45-55 years), (14) males and (11) females. collection of stimulated salivary samples was performed under standard conditions following the instructions cited by (tenovuo &lagerlof) (7). salivary flow rate was expressed as milliliter per minute (ml\min). the salivary samples were then taken to the laboratory for biochemical analyses. samples then centrifuged at 4000 rpm for 30 min; the clear supernatant was separated by micropipette and divided into 2 portions, stored at (-20 c) in a deep freeze till being assessed in the laboratory. clinical examination and oral health assessment were carried out under the standardized conditions of oral health surveys of who (8). for dental plaque, selected teeth were examined which was ramfjord teeth (9).the four surfaces of each tooth were examined and scored following the criteria of plaque index (pli) by silness and loe (10); this assessment done before saliva sample collection. for dental calculus, the four surfaces of ramfjord teeth were examined and scored following the criteria of calculus component of the periodontal index. gingival health status, the four surfaces of ramfjord teeth were examined and scored following the criteria of gingival index (gi) for loe and silness. loss of attachment (loa) was done after the patient's teeth were divided into six sextants, a selected tooth from each sextant was examined by using community periodontal probe (cpi probe), and the maximum score of all the examined teeth were recorded as loa score of that patient(8). dental examination was done after collection of salivary sample. according to the who modified decayed-missing-filled index (dmf) examination was done with a plane mouth mirror and cpi probe. a systematic approach of examination was performed starting from upper right second molar and proceeding in an orderly manner from one tooth or space to the adjacent tooth or space reaching upper left second molar passing to the lower left second molar and then to the lower right second molar(8). salivary cytokines assessment: (r and d) system, quantikine enzyme-linked immuno sorbent assay (elisa) (sandwich technique). before starting the procedure, all reagents were brought to room temperature and mix gently until the crystals completely dissolved and then the procedure was done according to the manufacturer insetructions for both il-6 and tnf-α. results caries experience: the mean values of dmfs index were higher in the newly diagnosed group followed by the control group and then the treated group but the lsd test showed that differences were statistically not significant between each two groups(p>0.05). mean value of the decayed surfaces (ds) was higher in the newly diagnosed group. however; the differences were statistically not significant among the three groups (p 0.05).on the contrary the mean value of missing surfaces (ms) was higher in the control group and the differences were statistically not significant among the three groups. .control group showed a higher value of filled surfaces (fs) and statistically the differences were proved to be significant only between the treated and control groups (p<0.05) (table 1). plaque index (pli) was higher in the newly diagnosed group, and anova test show that the difference was significant among the three groups (p<0.05). the lsd test show that the differences j bagh college dentistry vol. 25(special issue 1), june 2013 estimation of 142pedodontics, orthodontics and preventive dentistry were statistically significant only between the newly and the control group (p 0.05) (table 2). calculus index (cali) was higher in the newly diagnosed group. anova test show that the difference was not significant among the three groups and the lsd test shows that the difference was statistically significant between the newly diagnosed group and the treated group but not significant between the newly diagnosed and the control group (p> 0.05) (table 2). gingival index (gi) was higher in the control group followed by newly diagnosed group then the treated group. anova test show that the difference was highly significant among the three groups (p<0.01) and the lsd test showed that the difference was statistically highly significant between the new and control groups and also highly significant between control group and the treated group (p<0.01) (table2). loss of attachment index (loa) was higher in the control group. anova test show that the difference was not significant among the three groups (p>0.05) but lsd test show that the difference was statistically significant between the control group and each one of the other two groups (p<0.05) (table 2). salivary flow rate (sfr) was higher in the control group. anova test show that the difference was significant among the three groups, and the lsd test show that the difference was significant between the control and the newly diagnosed group (p<0.05) and highly significant between control and the treated group (p<0.01) (table 2). cytokines level: interleukin6 levels was higher in the newly diagnosed group. anova test show that the difference among the three groups was significant (p<0.05), lsd test show that the difference was statistically significant between the new and the treated group (p< 0.05) and it was highly significant between the new and the control group (p< 0.01) but it was not significant between the treated and control group (p>0.05) as shown in (table 3). regarding tnfα, anova test show that the difference was highly significant among the three groups (p<0.01). it s level was higher in newly diagnosed group and the difference was statistically significant with the treated group (p 0.05) and highly significant with the control group, but the difference was not significant between the treated and the control group (p>0.05) (table 3). the cut off value test: show the sensitivity and the specificity of the eliza cytokines test done in this study which was acceptable for both il-6 and tnf-α since the percent of both is near 70% (table 4). discussion in this study all participants was found to have dental caries and the difference in dmfs index was statistically not significant among the three groups and this finding was also reported by other studies (5) and it was higher in the newly diagnosed group as those patients had painful mucositis and bleeding tendency leading to alteration in their oral hygiene measures and food type. saliva may affect cariesexperience through its physical and chemical constituent (11).in this study the significant difference in salivary flow rate between the control and the newly diagnosed group may give an explanation for the increase in caries experience in this group, and for the treated group dmfs index was less than the other two groups may be because patients usually give more attention for their oral health to prevent the need for more aggressive dental procedure. plaque index was higher in the newly diagnosed group with a statistically significant difference with the control group and this result is in consistent with (6) which may explained by the decreased salivary flow rate, neglected hygienic measures and the type of diet of those patients as leukemia cause a burning mucositis that made tooth brushing painful and also made the patients have a tendency toward the soft food (12)in the treated group plaque index become less, this may be because treatment made the patients oral mucosa better so brushing became possible and may because the instructions given for the cml patients regarding the importance of good oral hygiene to prevent the need for any procedure that could cause bleeding or infection (13). differences in calculus index was significant only between the newly and the treated group, this result can be explained only by the fact that there are many factors effect dental calculus including the amount of dental plaque, which was higher in the newly diagnosed group, salivary flow rate which was lower in the treated group, and salivary composition (14). gingival index, was higher in the control group with a statistically highly significant difference with both the newly diagnosed and the treated group, and that was a confusing result as plaque index was the least in the control group and many previous studies reported a positive correlation between plaque and gingival indices (15), this result can be explained by the immune disturbances of those patients comparing to the normal subjects that lead to impaired inflammatory response. j bagh college dentistry vol. 25(special issue 1), june 2013 estimation of 143pedodontics, orthodontics and preventive dentistry data of the current study show no impact of the cml on the loss of attachment since it was higher in the control group than in the other two affected groups with a significant difference; this result was expected since gingival index was higher in the control group and can be explained by the difference in the immune factors of the three studied groups. in the newly diagnosed group, il-6 and tnf-α were highly increased comparing to the control group this may cause decrease in gingivitis and loss of attachment. the mean value of the salivary flow rate was higher in the control group then the newly diagnosed group and the treated group and the differences was significant with the newly diagnosed (p<0.05) and highly significant with the treated group (p<0.01) and the lower value in the newly diagnosed group could be explained by the effect of medications such as analgesics because cml patients usually have abdominal pain before the diagnoses (16). the mean value of il-6 was higher in the newly diagnosed group than the treated group and the control group and the difference was highly significant with the control (p<0.01) and significant with the treated group (p<0.05), this results could be compared with anand et al(17) ,who found that the level of il-6 was significantly higher in the serum of newly diagnosed cml patients because of the fact that saliva is the mirror of the serum (18). this increase in the salivary il-6 in the newly diagnosed group may explain why gingival index and loss of attachment was higher in the control group comparing to the newly diagnosed one since il-6 act as proinflammatory and anti-inflammatory mediators (19). tnf-α level in the saliva of the newly diagnosed cml patients was the higher with a significant deference with the treated group and highly significant difference with the control group; this result is agreed with the fact that dysregulation of tnf-α production is involved in many types of cancer and autoimmune diseases (20). table 1: comparison of the mean (dmfs) and its component in the three groups enrolled in the present study table 2: comparison of mean plaque index, gingival index, calculus index, loss of attachment and salivary flow rate among the three groups. variables descriptive statistic comparative statistic f-value lsd newly diagnosed group (mean±se) treated group (mean±se) control group (mean±se) p1 new + treated p2 new + control p3 treated + control pli 1.56+0.11 1.29+0.11 1.19+0.09 0.034* 0.061 0.012* 0.508 gi 0.71+0.07 0.63+0.06 0.94+0.06 0.002** 0.387 0.009** 0.001** call 0.32+0.06 0.18+0.03 0.22+0.04 0.085 0.033* 0.108 0.591 loa 0.28+0.09 0.28+0.09 0.56+0.10 0.062 1.000 0.041* 0.041* salfr 1.62+0.12 1.47+0.13 1.96+0.11 0.016* 0.383 0.048* 0.005** variables descriptive statistic comparative statistic f value lsd newly diagnosed group (mean±se) treated group (mean±se) control group (mean±se) p1 new + treated p2 new + control p3 treated + control dmfs 27.44+5.02 22.20+4.29 25.96+2.72 0.652 0.372 0.800 0.521 ds 11.80+2.79 9.64+3.28 5.20+0.99 0.183 0.551 0.071 0.222 ms 13.76+3.73 11.28+2.60 16.92+2.66 0.426 0.566 0.465 0.194 fs 1.92+0.83 1.28+0.57 3.84+0.90 0.059 0.562 0.085 0.023* j bagh college dentistry vol. 25(special issue 1), june 2013 estimation of 144pedodontics, orthodontics and preventive dentistry table 3: comparison of mean interleukin-6 and tumor necroses factor-α among the three groups variables descriptive statistic comparative statistic f-value lsd newly diagnosed group(mean±se) treated group (mean±se) control group (mean±se) p1 new+ treated p2 new+ control p3 treated+ control il6 134.60+25.51 76.86+18.25 56.00+8.33 0.012* 0.033* 0.004** 0.434 tnfα 135.20+13.28 99.40+6.72 88.60+7.82 0.001** 0.011* 0.001** 0.434 table 4: the cutoff value for il6 and tnfα il-6 cutoff value = 57.5 tnf cutoff value = 87.5 sensitivity 64 % 76 % specificity 68 % 78 % area uc 0.730 0.775 p-value 0.005 0.001 figure 1: receiver operator characteristic curve (roc) to determine the cutoff values for both il6 and tnfα table 5: number of positive and negative cases in the newly diagnosed and the treated groups, calculated according to above mentioned cutoff value of il-6 negative positive groups no. % no. % new 9 36% 16 64% glivic 16 64% 9 36% table 6: number of positive and negative cases in the newly diagnosed and the treated groups, calculated according to above mentioned cutoff value of tnf-α negative positive groups no. % no. % new 6 24% 19 76% glivic 12 48% 13 52% j bagh college dentistry vol. 25(special issue 1), june 2013 estimation of 145pedodontics, orthodontics and preventive dentistry references 1. greaves mf. biological models for leukaemia and lymphoma. 2nd ed. london: iarc sci publ; 2004. p. 351-72. 2. bullock l henze l. focus on pathophsiology. 3rd ed. philadelphia: lippincott williams and wilkins; 2000. p. 42-50. 3. karbasian m, morris e, dutcher j, wiernik p. blastic phase of chronic myelogenous leukemia. current treatment options in oncology. 3rd ed. copenhagen: copenhagen; 2006.p. 189–199. 4. hoffbrand a, moss p, pettit j. essential haematology. 4thed. oxford: blackwell science; 2006. p. 15-20. 5. dens f, boute p, otten j, vinckier f, declerck d. dental caries, gingival health, and oral hygiene 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(eds). textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1996. p.43. 8. who: oral health surveys. basic methods. 4th. genora 1997. 9. ramfjord s. indices for prevalence and incidence of periodontal disease. j periodontal 1959; 30: 51-9. 10. silness j, loe h. periodontal disease in pregnancy ii. j acta odontal scand 1964; 24: 747-759. 11. harris n, godoy f. primary preventive dentistry .6th ed. new jersey: upper saddle river; 2004. p.88. 12. ross j, kasum c, davies s, jacobs d, folsom a, potter j. diet and risk of leukemia in the iowa women's health study. j cancer epidemiology biomarkers 2002;11(8):777-81. 13. emidio t, maeda y, caldo-teixeira a, puppinrontani r. oral manifestations of leukemia and antineoplastic treatment a literature review (part ii). braz j health 2010; 1:136-49. 14. alnsudar j, kingman a, brown l. gingival inflammation and subgingival calculus a 5 determenauts of disease progression in early-onset periodontitis. j clin periodontal 1998; 25: 231. 15. tefferi a. classification, diagnosis and management of myeloproliferative disorders. hematology educ program; 2006. p. 240–5. 16. faguet, b. the war on cancer. springer isbn; 2005. p. 1020-1083. 17. anand m, chodda sk, parikh pm, nadkarni js .abnormal levels of proinflammatory cytokines in serum and monocyte cultures from patients with chronic myeloid leukemia in different stages, and their role in prognosis. j hematol oncol 1998; 16(4): 14354. 18. vanbruggen d, hackney c, mcmurray g, ondrak s. the relationship between serum and salivary cortisol levels in response to different intensities of exercise, saliva as a mirror of serum. j sports physiol and performance 2011; 6(3): 396-407. 19. song m, kellum j. interleukin-6. j crit care med 2005; 33(12): 463-5. 20. cronstein b. interleukin-6: a key mediator of systemic and local symptoms in rheumatoid arthritis. j bull nyu hosp joint dis 2007; 65(1): 11-15. j bagh college dentistry vol. 32(1), march 2020 influence of smoking 28 influence of smoking on salivary interleukin-8 levels in chronic periodontitis haween t. nanakaly (1), aveen e. ismail (2), daldar a. othmn (3) abstracts background: smoking is the major environmental risk factor that has been associated with the pathogenesis and progression of periodontal diseases. interleukin-8 (il-8), has been associated with the immunopathology of periodontitis. objectives: to determine the influence of smoking on salivary interleukin-8 level from smokers and non-smokers with periodontitis and periodontally healthy control subjects. materials and methods: un-stimulated saliva samples were collected of 90 participants: 30 smokers and 30 non-smokers with chronic periodontitis, as well as 30 periodontally healthy control subjects. the clinical parameters such as the pocket depth, clinical attachment loss, plaque index, and gingival index were measured. il-8 level in the saliva was measured by enzyme linked immunosorbent assay (elisa) kit. results: it was found that the mean value of salivary il-8 levels was significantly higher in smokers (461.76 ± 329.66 ng/l) than in non-smokers periodontitis (257.83 ± 247.19 ng/l) and the controls (96.55 ± 62.35 ng/l) (p < 0.001). moreover, salivary il-8 levels were significantly higher in smokers compared with non-smokers periodontitis (p< 0.001). conclusion: smoking subjects showed increased level of salivary il-8 and a worse periodontal condition than non-smoking subjects. our results suggest that smoking alters an immune response which may contribute to an increased susceptibility to periodontal disease among smokers keywords: smoking; chronic periodontitis; saliva; interleukine-8. (received: 15/8/2018; accepted: 30/9/2018) introduction saliva is a fluid, which provides a primary growth environment for oral flora of the oral cavity. salivary secretions are protected in nature because they preserve the oral tissues in a physiological state. as the physic-chemical properties are changed, it affects the microorganisms which grow in the mouth. therefore, the protective effect of saliva may be accomplished by means of secretion rate, buffering capacity, phosphate and calcium concentration (biochemical substances, antibacterial components, and different antioxidants).(1) saliva with and without stimulation is readily accessible via a totally noninvasive collection method, which contains locally produced microbial and host response mediators. subsequently, the use of saliva for periodontal diagnosis and monitor response to treatment has been the subject of considerable research activity, and proposed markers for disease including enzymes, proteins, immunoglobulins, cytokines, host cells, etc.(2) (1) asst. prof. department of basic sciences, college of dentistry, hawler medical university (clinical immunology) (2) asst. lect. department of periodontology, college of dentistry, hawler medical university (periodontology) (3) asst. lect. department of periodontology, college of dentistry, hawler medical university (periodontology) periodontitis is an array of inflammatory diseases affecting the supporting tissues of teeth and resulting in periodontal pocket formation and alveolar bone resorption, which might eventually lead to tooth loss. it is a chronic inflammatory disease associated with gram negative anaerobic bacteria present in the dental biofilm, leading to an excessive inflammatory response, which is influenced by several risk factors, such as stress and host-specific factors or habits, such as smoking.(3) a complex interaction between these bacteria and host defensive capacity results in periodontal tissue breakdown.(4) the presence of periodontopathogens, such as porphyromonas gingivalis, tannerella forsythia, and treponema denticola is considered the predominant etiologic agents in periodontitis,(5) triggers the expression of proinflammatory cytokines, such as interleukin-1(il-1), interleukin6(il-6), interleukin-8 (il-8), tumor necrosis factor-α (tnf-α) and matrix metalloproteinases (mmps), which have been related with the immunopathology of periodontitis. these mediators may affect the activities of leukocytes, osteoblasts and osteoclasts and stimulate the tissue remodelling process systematically and locally.(6) interleukin-8 (il-8), is formerly known as neutrophil-activating peptide-1 (nap-1), a member of the cxc chemokine family, plays a significant role in the recruitment and activation of j bagh college dentistry vol. 32(1), march 2020 influence of smoking 29 neutrophil during inflammation.(7) il-8 is predominantly produced by gingival endothelial cells, fibroblasts, keratinocytes and macrophages in response to periodontal bacterial and bacterial components. il-8 is a potent pro-inflammatory cytokine that regulates alveolar bone resorption during tooth crusade by acting early in the inflammatory response,(7,8) thus directly contributing to the progression of the periodontal lesion.(8,9) the expression of il-8 mrna and protein have been detected to be increased in chronically inflamed periodontal tissue, as well as gingival crevicular fluid of patients with periodontitis.(10,11) it is recognized that overproduction and excessive il-8 mediated chemotactic and activation having effects on neutrophils in the inflamed gingiva may contribute to the periodontal tissue impairment.(12) smoking is the major risk factor, which is closely related with extent and severity of periodontal diseases.(13) cross-sectional studies have consistently shown that smokers are two to six times more likely to have severe periodontitis than non-smokers.(14) in addition, clinical studies have recognized that severe periodontal disease with increased bone loss, greater periodontal attachment loss, more gingival recession and periodontal pocket formation are more frequent in smoking patients with periodontitis compared to nonsmokers.(15,16) it is well established that smoking alters the host response, including changes vascular function, neutrophil/monocyte activities, adhesion molecule expression, cytokine and inflammatory mediator release, as well as antibody production.(17,18) these changes likely contribute to the negative effect of smoking on the reparative and regenerative potential of the periodontium. various studies have stated the possible role of il8 in gcf as a biomarker for periodontal disease but less literature is available on its role in saliva. based on these findings, it seems reasonable to speculate that il-8 may influence the initiation and progression of periodontitis. thus, the aim of present study was to assess the influence of smoking on periodontal health by estimating the il-8 level in saliva of smokers and nonsmokers with chronic periodontitis. the il-8 levels in saliva among individuals with healthy periodontium, smokers and non-smokers with periodontitis were also compared and correlated with clinical findings. materials and methods study population: the protocol for the present case-controlled study was approved by the committee of ethics at college of dentistry/ hawler medical university. written informed consent was obtained from all participants before conducting the study. ninety male participants, aged between 25-50 years old were selected by random sampling from patients attending outpatient clinics of the department of periodontitics at college of dentistry, hawler medical university from february to august 2017. subjects were categorized into three groups: group-i comprised of 30 smokers with chronic periodontitis; group-ii comprised of 30 non-smokers with chronic periodontitis; and group-iii comprised of 30 nonperiodontitis and non-smoking controls. periodontitis diagnosis was based on the classification of american academy of periodontology.(19) patients with at least 30% of sites with loss of attachment were classified as having generalized chronic periodontitis and radiographic evidence of bone loss. subjects must not have less than 20 standing teeth in their mouth. the periodontal patients group included individuals with probing pocket depth (ppd) ≥ 5 mm and clinical attachment level (cal) ≥ 3 mm (> 30% affected sites). furthermore, current smokers who smoked ≥ 10 cigarettes per day for not less than 2 years and who fulfilled the criteria of chronic periodontitis, were enrolled in the study. the control group consisted of individuals without a history of periodontal disease and attachment loss, as well as probing pocket depth (ppd) ≤ 3 mm. all the participants were systemically healthy; had no medical history or clinical evidence of any acute or chronic diseases; had no intraoral inflammatory and noninflammatory lesions; had no history of antibiotic and anti-inflammatory drug treatment within the previous 6 months; had no history of scaling and root planning for at least 6 months prior to sampling and recording. saliva sampling and analysis: unstimulated whole expectorated saliva (3 ml) was collected from each subject between 8:00 and 11:00 a.m. (at least 2 hours after a meal) before doing periodontal examination according to a modification in the method described by navazesh.(20) subjects were requested to rinse their mouth with distilled water thoroughly to remove exfoliated cells and food debris, which they j bagh college dentistry vol. 32(1), march 2020 influence of smoking 30 expectorated at least 3 ml of un-stimulated whole saliva into a 5ml sterile tubes while seated in an upright position. collected samples were placed immediately on ice pack, then transported to the laboratory and centrifuged at 3500 rpm for 10 minutes. the supernatant structure was kept frozen at -40 ºc as aliquots till analysis. salivary il-8 levels were measured with an elisa kit using human interleukine-8(il-8) provided by expert chem serv (catalog # dre10290) according to manufacturerʼs instructions. the standard range was 50ng/l1000 ng/l. clinical parameters: clinical measurements and radiographic examination of all participants were performed by a single experienced examiner after the collection of saliva sample. the gingival index (gi),(21) plaque index (pi),(22) probing pocket depth (ppd), clinical attachment level (cal) using unc 15 probe were measured at six sites for all the present teeth except third molar. statistical analysis: the descriptive data were expressed as mean and standard deviation (mean ± sd). comparison of clinical parameters of the three groups was analyzed using t-test and analysis of variance by one-way anova test. comparison of salivary il8 level among three groups was analyzed by oneway anova test. pair-wise comparison was performed by tukey’s multiple comparison tests to determine the difference of salivary il-8 level between the groups. possible correlations between salivary il-8 levels and clinical periodontal parameters were assessed by the spearman’s correlation coefficients. statistical analyses were performed with spss version 22 (spss, chicago, il, usa), and p-value<0.05 were considered statistically significant. results the mean age of the participants was 39.10 ± 4.71 years in group i; 38.83 ± 3.29 years in group ii; and 38.40 ± 4.64 years in group iii with no significant differences among the three study groups (p > 0.05). all clinical periodontal parameters were significantly higher in the patients groups as compared to the healthy control. on the other hand, the mean ppd, cal, and pi were significantly higher in the smokers group compared to non-smokers (p < 0.001), while the mean gi score among the smokers ( 1.30 ± 0.28) was significantly less than that of non-smokers (2.51 ± 0.39) (p < 0.001) (table 1). the mean values of salivary il-8 levels in smoker and non-smoker periodontitis groups were higher than in the control group (figure 1). salivary il-8 level was significantly higher in smokers, followed in descending order by non-smokers and the controls with the mean values of (461.76 ± 329.66, 257.83 ± 247.19, and 96.55 ± 62.35 ng/l) respectively. with respect to salivary il-8 levels, a pairwise comparison between the groups also showed a highly statistically significant results (p< 0.01) (table 2). by spearman correlation coefficient analysis, in smokers and non-smokers with chronic periodontitis and control groups, salivary il-8 levels did not show any significant correlation with clinical parameters of periodontal disease (ppd, cal, pi, and gi) (all p > 0.05, data not shown). figure 1: mean levels of il-8 in saliva of smoker and non-smoker periodontitis groups and control group discussion smoking is one of the most important risk factors for periodontal disease. it has been shown that various components of tobacco smoke, nicotine act on the periodontal tissues causing destruction of the supporting tissues.(23) il-8 is a multifunctional cytokine that plays a role in immune and inflammatory activities like recruitment and activation of neutrophils.(9) thus, this study attempted to estimate and compare the level of il8 in saliva of smokers and non-smokers with chronic periodontitis and correlate these levels with the severity of periodontal diseases. in the present study, smokers with chronic periodontitis had significantly increased ppd, j bagh college dentistry vol. 32(1), march 2020 influence of smoking 31 table 1: comparison of the three groups with respect to clinical periodontal parameters. clinical parameters§ group i group ii group iii p-value ppd 5.82± 0.75 5.25 ± 0.27 1.97± 0.63 0.000* cal 4.93± 1.07 3.90± 0.73 0.00± 0.00 0.000* pi 1.86± 0.42 1.27± 0.33 0.37± 0.15 0.000* gi 1.30 ± 0.28 2.51± 0.39 0.79± 0.27 0.000** § values expressed as mean ± sd ppd=probing pocket depth, cal= clinical attachment level, pi=plaque index, gi= gingival index group i= smoker, group ii= nonsmoker, group iii= control * statistical difference at p< 0.05 by anova test ** statistical difference at p< 0.05 by kruskal-wallis test table 2: comparison of the three groups with respect to salivary il-8 levels study groups salivary il-8 comparison mean differences p-value* mean ± sd mean ± sd group i: smoker 461.76 ± 329.66 i vs ii 209.6 ± 364.91 0.004 group ii: nonsmoker 257.83 ± 247.19 i vs iii -209.6 ± 155.32 0.000 group iii: control 96.55 ± 62.35 ii vs iii -364.91 ± 155.32 0.030 *significance at p< 0.05 by hsd (honest significant difference) cal, and pi, compared to non-smokers (p < 0.001). however, the gingival index (gi) was significantly higher in non-smokers with chronic periodontitis than in smokers (p < 0.001). previous studies (24,25) showed similar results. jenifer et al.,(26) found a positive relationship between periodontal disease and smoking and have also reported a positive correlation with greater probing depth, attachment loss and plaque index in smokers. this supports the concept that smokers are generally presented with reduced gingival inflammation and bleeding on probing, compared to non-smokers, because smoking has a strong, chronic, dose-dependent suppressive effect on gingival inflammation and bleeding on probing.(27) results significantly showed increased il-8 levels in the saliva of smokers with periodontitis, compared to non-smokers with periodontitis and healthy controls (p< 0.001). comparing between smoker with periodontitis and control group, salivary il-8 level increased significantly and this relationship was highly significant (p < 0.001) the same results were obtained when non-smokers with chronic periodontitis and control group were compared. again, there was significant increase in salivary il-8 level (p < 0.001). comparing smoker to non-smoker periodontitis groups, it was found that salivary il-8 level increased significantly (p < 0.001). our results demonstrated that smoking significantly influences salivary il-8 levels in periodontitis patients. studies evaluating the effects of smoking on the expression of il-8 level in periodontitis patients, have suggested that smoking increases the il-8 expression in gcf.(25,28) it has also been reported that following periodontal therapy il-8 levels decreased significantly in non-smokers, while in smokers it increased steadily and became significantly higher than in non-smokers.(28) it is primarily attributed to the fact that tobacco smoke activates more cells of the periodontium to express il-8, thereby resulting in a local accumulation of polymorphonuclear cells (pmnʼs).(29) the results of our study explain the hypothesis that an exaggerated response by neutrophils occurs in response to increased il-8 expression in smokers, suggesting an effect of smoking on the inflammatory responses against oral pathogens. interestingly, increased gcf production of inflammatory molecules, such as il-1β, il-6, and il-8, and suppression of anti-inflammatory molecules, such as il-4, were discussed to imply increased periodontal destruction among smokers.(30) moreover, johnson et al.,(31) reported that nicotine can directly modify the production of cytokines and inflammatory mediators, causing increased il-1, and il-8 production by gingival keratinocytes. nicotine also has a deleterious effect on the gingival and periodontal fibroblasts leading to further periodontal progression and periodontal tissue destruction.(32) a study on vitro by lizheng et al.,(32) demonstrated that nicotine j bagh college dentistry vol. 32(1), march 2020 influence of smoking 32 up-regulates the production of il-1β and il-8 via the α7nachr/nf-κb pathway in human periodontal ligament cells (pdl), which could be inhibited by pretreatment with pdtc or α-btx, suggested that α7nachr/nf-κb pathway might play a key role in the up-regulation of these cytokines in smoking-associated periodontitis.(32) altogether, these studies underline the important role of smoking by assessing potential markers for periodontitis. in contrast to our results, some studies have shown significantly lowered il-8 level among smokers with chronic periodontitis in blood,(33) in gcf,(34) and salivary,(35) whereas other studies have reported no changes on the gcf levels of il1β,il-4,il-6 and il-8 among smokers and nonsmokers.(36) these studies have suggested that reduction in chemokines in smokers could contribute to the phenomena of impaired neutrophil chemotaxis and migration in the periodontium in spite of the presence of leucocytosis.(37) however, the increased level of salivary il-8 in our study confirmed several findings in medical literature on positive association between smoking and increased expression of pro-inflammatory and chemokine molecules particularly il-8. however, in the present study no correlation was found between clinical periodontal parameters ppd, cal, pi, gi and 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and stress on gingival crevicular fluid cytokine level. j clin periodontol. 2003;30:145-153. 31. johnson gk, guthmiller jm, joly s, organ cc, dawson dv. interleukin-1 and interleukin-8 in nicotineand lipopolysaccharide-exposed gingival keratinocyte cultures. j periodontal res. 2010;45:583588. 32. lizheng wu, yongchuan z, zhifei z, yingfeng l, yudi b, xianghui x, xiaojing w. nicotine induces the production of il-1β and il-8 via the α7 nachr/nf-κb pathway in human periodontal ligament cells: an in vitro study. cell physiol biochem. 2014;34:423-431. 33. fredriksson m j, bergström and b. åsman, il-8 and tnf-α from peripheral neutrophils and acute –phase proteins in periodontitis. effect of cigarette smoking: a pilot study. j clin periodontol. 2002;29:123-128. 34. tymkiw kd, thunell dh, johnson gk, joly s, burnell kk, cavanaugh je, et al. influence of smoking on gingival crevicular fluid cytokines in severe chronic periodontitis. j clin periodontol. 2011;38:219-228. 35. jain s, kaur h, aggarwal n, gupta m, saxena d, pandav g. comparative evaluation of salivary interleukin-8 levels in diabetics, hypertensives and smokers with chronic periodontitis. djas. 2014;2:145-149. 36. kamma jj, giannopoulou c, vasdekis vg, mombelli a. cytokine profile in gingival crevicular fluid of aggressive periodontitis: influence of smoking and stress. j clin periodontol. 2004;31:894902. 37. palmer rm, wilson rf, hasan as, scott da. mechanisms of action of environmental factors-tobacco smoking. j clin periodontol. 2005;32:180– 195. j bagh college dentistry vol. 32(1), march 2020 influence of smoking 34 :ةالخالص ( يكون مشاركا interleukin-8سيه المساهمه في التسبب و تطور مرض األنسجه ما حول الفم .)ان التدخين يعد احد العوامل الرئي :هدف البحثو ةخلفي ( اللعابي interleukin-8في عملية تقدم و تطور حاله المرض من الناحيه المناعيه لمرض األنسجه ما حول الفم.تحديد تأثير التدخين على مستوى ال ) مرض األنسجه ما حول الفم و مقارنتها مغ أشخاص ال يشكون من مرض األنسجه ما حول الفم و على مرضى)مدخنين و غير مدخنين( يعانون من .(controlاعتبارهم عينه سيطرة) سريريا على 30غير مدخن و 30مدخن و 30مشارك تم تصنيفهم على ثالث مجاميع : 90عينات من اللعاب الغير محفز تم جمعه من :المواد والطرق .المعايير السريريه مثل عمق الجيب اللثوي, مستوى فقدان االلتماس, فهرس البالك و فهرس اللثه تم قياسهم. صحه تامه في ما يخص األنسجه ما حول الفم (. elisaفي اللعاب تم قياسه بأستعمال عدة فحص انزيم األرتباط المناعي ) il-8مستوى ال ( اللعابي كان كبير جدا في مجموعه المدخنين الذين يعانون من من مرض interleukin-8لتجربه لقد وجد ان معدل القيمه لل )من خالل هذه ا :النتائج ± 257.83( بالمقارنه مع غير المدخنين الذين يعانون من من مرض األنسجه ما حول الفم ) ng/l 329.66± 461.76األنسجه ما حول الفم ) 247.19 ng/lوفي مج ) ( موعه الcontrol( )96.55 ±62.35 ng/l) (p < 0.001( اما مستويات ال .)interleukin-8 اللعابي في الألشخاص ) . p< 0.001) الذين يعانون المرض فقد كانت كبيره جدا في مجموعه المدخنين عنده مقارنتها مع غير المدخنين ) ( اللعابي ترافها تزايد في سوء حاله األنسجه ما حول الفم بالمقارنه مع غير interleukin-8ل )األشخاص المدخنين اظهرو مستويات مرتفعه ل :األستنتاج م بين المدخنين المدخنين. نتائجنا تقترح ان التدخين قد يغير في استجابه الجهاز المناعي و الذي قد يساهم في زيادة سوء حاله مرض األنسجه ما حول الف ما حول الفم . الذين يعانون من مرض األنسجه moamin.doc j bagh college dentistry vol. 27(2), june 2015 evaluating the effect restorative dentistry 17 evaluating the effect of silver nanoparticles incorporation on antifungal activity and some properties of soft denture lining material moamin i. issa, b.d.s. (1) nabeel abdul-fattah, b.d.s., m.sc. (2) abstract background: colonization of soft denture liners by candida albicans and other microorganisms continued to be a serious problem. the aim of this study was to evaluate the effect of incorporating silver nanoparticles into heat cured acrylic-based soft denture liner on the antifungal activity, and on water sorption, solubility, shear bond strength and color change of the soft lining material. furthermore, evaluating the amount of silver released. materials and methods: silver nanoparticles were incorporated into soft denture liner in different percentages (0.05%, 0.1% and 0.2% by weight). four hundred and twenty specimens were prepared and divided into five groups according to the test to be performed. the antifungal activity of the soft liner/agnps composite was evaluated in three different periods by using (viable count of c. albicans and disk-diffusion test). the amount of silver released in artificial saliva was measured by atomic absorption spectroscopy. the water sorptions, solubility, shear bond strength and color change was measured and the results were statistically analyzed. results:all experimental groups showed a highly significant decrease in colony forming units of c. albicans in comparison to control group. there was no inhibition zone around any test specimen of any test group. there was no silver detected to be released. the addition of agnps resulted in a highly significant decrease in water sorption, while only 0.2% group showed highly significant decrease in solubility. non significant differences in shear bond strength were found. a highly significant increase in light absorption percentage was observed in all experimental groups. conclusion: the addition of agnps helps to produce soft denture liner with antifungal properties. silver was not detected to be released. this addition resulted in decrease in water sorption, and did not affect the shear bond strength and it increased the opacity of the material. keywords: soft denture liners, antifungal activity, silver nanopaticles. (j bagh coll dentistry 2015; 27(2):17-23). introduction soft denture liners represent polymeric materials which can be placed on the tissue surface of a hard denture base to absorb some of the load resulted from the masticatory forces, and to act as shock absorbers between the hard denture and the underlying supporting oral tissues.(1) one of the main drawbacks associated with using soft denture liners is their susceptibility to be colonized by pathological microorganisms which can be enhanced by increased humidity and high temperature beneath the dentures and by the surface characteristics of the material.(2) candida albicans was isolated from the surface of soft denture liner and it was considered as one of the etiological factors of denture stomatitis.(3) in addition to that some studies showed that c. albicans has the ability to penetrate into different levels of the soft lining materials. this could limit the cleaning efficiency of the available chemical agents.(4) mechanical and chemical plaque control proceduresare frequently used to prevent subsequent denture stomatitis. (1) m.sc. student. department of prosthodontics. college of dentistry, university of baghdad. (2) professor. department of prosthodontics, college of dentistry, university of baghdad. however, to some geriatric or hospitalized patients suffering from cognitive impairment, reduced motor dexterity or memory loss cleaning the denture may be a difficult procedure. in addition to that, these methods can cause substantial damage to the soft lining materials. (5-7) silver is well known for its antimicrobial activity against different bacteria, fungi and certain viruses (8), and recently the antimicrobial properties of nanoparticles have drawn attention of researchers.(9) smaller particle size results in greater surface area to volume ratio, which enhances its chemical and biological activity.(10) particularly, silver nanoparticles with their antimicrobial properties have elicited high interest, and their incorporation into polymers can be beneficial in wound dressings and sutures, venous and urinary catheters, endotracheal tubes, drugs, artificial tendons and orthodontic adhesives. (11) in the present study silver nanoparicles were incorporated in to acrylic-based soft denture liner in an attempt to minimize the microbial growth of c. albicans, and evaluating whether this addition would significantly affecting the mechanical and physical properties of the soft lining material ,in addition to evaluate silver release. j bagh college dentistry vol. 27(2), june 2015 evaluating the effect restorative dentistry 18 materials and methods heat cured acrylic-based soft denture liner (vertex™ soft, vertex-dental, netherlands) was used in this study. silver nanopowder (mk nano, canada) was incorporated into the soft liner in different percentages (0.05%, 0.1% and 0.2% by weight). a total of four hundred and twenty specimens were prepared and divided into five groups according to the test to be performed. ftir analysis was performed to determine if there is any chemical reaction between agnps and the soft liner. evaluating antifungal activity of soft liner /agnps specimens using viable count of c. albicans: specimen fabrication specimens with dimensions of (10× 10 × 2.3mm, length, width and thickness respectively) were prepared using plastic patterns to make a silicon-stone mould. the soft lining material was mixed packed and cured according to manufacturer’s instructions. for experimental specimens agnps were added into the liner monomer and dispersed by using probe sonication apparatus(soniprep-150, england) for 3 minutes to break them into individual nanoparticles.(12) the mixture was cooled down by placing the container in a cooling bath (ice-water bath), to prevent bulk heating of the liquid during sonication which can cause substantial liquid evaporation, or the degradation of the material.(13) after complete curing the specimens were finished polished and autoclaved to be sterile. isolation of c. albicans c. albicans was isolated from the oral cavity of 18 patients with signs of denture stomatitis and oral thrush,by gentle rubbing of the lesional tissue by a sterile cotton swab, and subsequent culturing on sabouraud dextrose agar(that was prepared according to manufacturer’s instructions) and incubated aerobically at 37°c for 24 48 hrs. identification of c. albicans it was identified by colony morphology as it develops as creamy, smooth, pasty convex colonies on sda (14) ,and by microscopical examination using gram stain method (15), furthermore, germ tube formation procedure was used (16), and the final verification was made by biochemical method by using api candida system (biomérieux). evaluating viable count of c. albicans to examine the antimicrobial activity of the soft liner/agnps composites, c. albicans was diluted in 0.9% nacl, and a yeast suspension of approximately 107 cfu/ml (0.5 mcfarland standards) was prepared using a mcfarland densitometer. each specimen was placed in a tube containing 9.9 ml of sabouraud dextrose broth, into which were dispensed 100 μl of the yeast suspension. the final concentration of cells was 105cfu/ml. (11) after incubation for 24 hours at 37◦c, 100µl of each mixture was transferred to 9.9ml of nacl (0.9%) and tenfold dilution was performed. from the second dilution, 100µl was taken and spread on sda and incubated aerobically for 24hrs at 37ºc (fig.1). this procedure had been repeated after 7 days and 30 days of specimens' storage in artificial saliva at 37ºc. figure 1: (a)inoculation of broth with c. albicans, (b)placement of specimen in the broth, (c)serial dilution,(d) c. albicans growth. evaluating antifungal activity of soft liner /agnps specimens using disk-diffusion test: specimens used in this test were (6mm in diameter and 0.5mm in thickness). the culture medium used for this test was mueller-hinton agar (that prepared according to manufacturer's instructions) containing 2% glucose and 5μg/ml methylene blue. (17) kirbybaure disk diffusion test was performed. five-well isolated colonies of c. albicans were suspended in 0.85 % sterile normal saline 5 ml to achieve 0.5 mcfarland turbidity to yield a yeast stock suspension. a sterile swab was dipped into the inoculum suspension and excess fluid was pressed out. the agar was swabbed in 3 directions to achieve even growth on the surface of the agar plate. (18) a d c b j bagh college dentistry vol. 27(2), june 2015 evaluating the effect restorative dentistry 19 after the agar surface has been left for about 5 minutes, then the soft liner disks (with and without agnps) were placed on the agar and the plates were kept at room temperature for 120 min for diffusion of the antimicrobial agents (19), then these agar plates were incubated aerobically for 24 hrs at 37º c. a digital caliper used to measure the inhibition zone that may appear around the disks. silver release test the amount of silver released was evaluated by using specimens with dimensions of (10mm in diameter and 3mm in thickness)(11)and two atomic absorption spectrophotometers (phoenix-986/aa biotech engineering management co., and shimadzu aa-6800)with a limits of detection of(0.025ppm and 0.01ppb) respectively. all specimens were immersed in 25 ml of artificial saliva inside a plastic plane tubes and kept at 37◦c under agitation for two different periods: t1 = 7days, t2 = 30days. the volume of the artificial saliva was reconstituted every 10 days to account for evaporation. during each period solution of each tube was collected, and the amount of silver releasedwas analyzed by atomic absorption spectroscopy. watersorption and solubility test: disks measuring 50±1mm in diameter and 0.5±0.05mm in thickness were prepared for experimentaland control specimens according to ada specifications no.12 (20), by using metal patterns. all disk-shaped specimens were dried at 37ºc ± 2ºc for 24 hours in a desiccator containing dry silica gel, after that the specimens were removed to room temperature for one hour, and weighed with digital electronic balance with accuracy of (0.0001g).this cycle was repeated untilconstant weight (± 0.5mg) was obtained. this was considered to be the initial weight (w1). then specimens were immersed in distilled water for 7 days at 37ºc ± 2ºc. after this period of time, each specimen was removed from the water, wiped with clean, dry hand towel until free from visible moisture, waved in the air for 15 seconds and weighed one minute after removal of water. this weight represents (w2). after that the specimens dried by the desiccator and they were weighed every 24 hours until a constant weight (± 0.5mg) was obtained, this weight represents (w3). water sorption and solubility of each specimen were calculated according to the following formulae: sorption (mg / cm²) = solubility (mg / cm²) = shear bond strength test to evaluate shear bond strength of soft lining material to acrylic denture base, acrylic blocks with specified dimensions (75mm × 25mm × 5 mm length, width, depth respectively) with stopper of depth about 3mm needed to be made.(21) (fig.2a). heat cured acrylic resin (spofa dental, czech) was used. mixing packing and curing was done according to manufacturer’s instructions. then one block of the acrylic put over the other block leaving a space between them of (25mm × 25mm × 3mm length, width, depth respectively), that filled with wax. then the whole specimen (the 2 blocks with wax) was invested into silicon material to fabricate a mould for final specimen curing. wax elimination procedure was done and the formed space (25mm × 25mm × 3mm) was filled with soft lining material and curing was carried out (fig.2 b&c). the specimens were tested using instron testing machine (instron 1195, england). the maximum load required for failure was recorded in order to calculate the value of shear bond strength for each test specimen according to (astm specification d-638m, 1986) formula (22) : bond strength (n/mm2)= = figure 2: (a) acrylic block used in test, (b) custom-fabricated flask with silicon-stone mould. (c) shear bond strength test specimen. a b c j bagh college dentistry vol. 27(2), june 2015 evaluating the effect restorative dentistry 20 color change test: disk-shaped specimens with 50 ± 1mm in diameter and 0.5 ± 0.05mm in thickness (in accordance with ada specifications no.12) (20) were prepared to be used for color change measurements by using uv-visible spectrophotometer (uv-160ashimadzu, japan) that evaluates color change by measuring the absorbed light percentage. results ftir analysis showed that there was no chemical interaction between the soft lining material and agnps. all experimental groups (0.05%, 0.1% and 0.2% agnps) showed a highly significant decrease in colony forming units of c. albicans in comparison to control group with more decrease as the incubation time in artificial saliva increase (table 1&2,fig. 3). disk-diffusion test didn’t show any inhibition zone around test specimens of any test group. there was no silver detected to be released in artificial saliva at any incubation period. the addition of agnps resulted in a highly significant decrease in water sorption mean value (table 3&4), while only 0.2% group showed highly significant decrease in solubility (table 5&6). non significant differences in shear bond strength found among all test groups (table 7). a highly significant increase in light absorption percentage observed in all experimental groups (table 8 & 9). table 1: descriptive statistics and one-way anova of viable count of c.albicans for all study groups and for different periods. incubation period groups mean s.d. anova f-test before incubation in saliva control 262.7 10.57 279.268 (hs) 0.05% ag 160 10.60 0.1% ag 158.1 9.05 0.2% ag 181.3 6.43 after 7 days of incubation in saliva control 249.8 7.66 306.291 (hs) 0.05% ag 149.6 9.12 0.1% ag 145.6 8.09 0.2% ag 164.6 10.29 after 30 days of incubation in saliva control 245.7 10.02 485.996 (hs) 0.05% ag 139.8 6.61 0.1% ag 136.1 8.75 0.2% ag 130.5 5.52 table 2: lsd test between viable count means. incubation period groups md p-value before incubation in saliva control 0.05% 102.7 0.000 (hs) 0.1% 104.6 0.000 (hs) 0.2% 81.4 0.000 (hs) 0.05 0.1% 1.9 0.651 (ns) 0.2% -21.3 0.000 (hs) 0.1% 0.2% -23.2 0.000 (hs) after 7 days of incubation in saliva control 0.05% 100.2 0.000 (hs) 0.1% 104.2 0.000 (hs) 0.2% 85.2 0.000 (hs) 0.05% 0.1% 4 0.319 (ns) 0.2% -15 0.001 (hs) 0.1% 0.2% -19 0.000 (hs) after 30 days of incubation in saliva control 0.05% 105.9 0.000 (hs) 0.1% 109.6 0.000 (hs) 0.2% 115.2 0.000 (hs) 0.05% 0.1% 3.7 0.303 (ns) 0.2% 9.3 0.013 (s) 0.1% 0.2% 5.6 0.123 (ns) md = mean difference figure 3: bar chart showing mean values of cfu/ml at different periods of the study for each experimental group. table 3: descriptive statistics and one-way anova of water sorption test results. groups mean s.d. anova f-test p-value control 0.806 0.137 8.973 0.000 (hs) 0.05% ag 0.643 0.095 0.1% ag 0.628 0.083 0.2% ag 0.601 0.057 j bagh college dentistry vol. 27(2), june 2015 evaluating the effect restorative dentistry 21 table 4: lsd test between water sorption study groups. groups mean difference p-value control 0.05%ag 0.163 0.001 (hs) 0.1% ag 0.178 0.000 (hs) 0.2% ag 0.204 0.000 (hs) 0.05% ag 0.1% ag 0.015 0.737 (ns) 0.2% ag 0.041 0.351 (ns) 0.1% ag 0.2% ag 0.026 0.548 (ns) table 5: descriptive statistics and one-way anova of solubility results. groups mean s.d. anova f-test p value control 0.223 0.037 24.359 0.000 (hs) 0.05% ag 0.202 0.035 0.1% ag 0.243 0.036 0.2% ag 0.130 0.007 table 6: lsd test between solubility study groups. groups mean difference p-value control 0.05% 0.021 0.141 (ns) 0.1% ag -0.020 0.158 (ns) 0.2% ag 0.093 0.000 (hs) 0.05% ag 0.1% ag -0.042 0.006 (hs) 0.2% ag 0.071 0.000 (hs) 0.1% ag 0.2% ag 0.113 0.000 (hs) table 7: descriptive statistics and one-way anova of shear bond strength test results. groups mean s.d. anova f-test p-value control 0.534 0.071 0.253 0.859 (ns) 0.05% ag 0.529 0.071 0.1% ag 0.548 0.042 0.2% ag 0.551 0.081 table 8: descriptive statistics and one-way anova of color change test results. groups mean s.d. anova f-test p-value control 0.120 0.013 70.664 0.000 (hs) 0.05% ag 0.144 0.012 0.1% ag 0.198 0.014 0.2% ag 0.236 0.033 table 9: lsd test between color change study groups. groups mean difference p-value control 0.05% ag -0.024 0.009 (hs) 0.1% ag -0.078 0.000 (hs) 0.2% ag -0.116 0.000 (hs) 0.05% ag 0.1% ag -0.054 0.000 (hs) 0.2% ag -0.092 0.000 (hs) 0.1% ag 0.2% ag -0.038 0.000 (hs) discussion in this study agnps were added into soft denture liner in an attempt to improve the antimicrobial properties of the liner against c. albicans yeast which is one of the main causative factors of denture-induced stomatitis. the results of this study showed a statistically highly significant decrease in colony forming units/ml of c. albicans after incorporating the soft denture liner with agnps. the antimicrobial efficacy seemed to be concentration dependant. the antifungal activity of the tested soft liner /agnps composite seemed to increase with the increase of incubation time in artificial saliva. the explanation for that could be due to the presence of specimens in aqueous environment for longer period, so there was a greater possibility of agnps oxidation and ag+ formation which enhance the antimicrobial activity , because the silver ions are the main active and reactive species of silver.(23) in addition to that movement of some agnps from the bulk of specimen to the surface might occur with increase in storage time, however silver or its ions were not detected to be released.(11) these phenomena together with decrease in water sorption could explain the lower level and later improvement of antifungal activity in (0.2% group). for disk-diffusion test, no inhibition zone was detected around specimens for any agnps percentage used even after incubating the specimens in artificial saliva. this could be explained by absence of silver ions release from soft liner/agnps composite which was verified by the results of this study. these findings indicated that the antifungal activity was achieved by contact kill; no ag+ leached out of the copolymer. (24) this was also confirmed by the results of this study as no silver or silver ions were detected in artificial saliva using atomic absorption spectroscopy at any incubation period. previous studies were made to evaluate silver release from different polymeric materials, and some of them confirmed the results of the present study (11), while others disagreed by detecting different concentrations of silver released. (25, 26) this could be explained by differences in the type of polymeric materials and their polymerization methods, in addition to differences in agnps incorporation methods. water sorption and solubility were evaluated simultaneously through water gain and loss of soluble components. the resulted decrease in water soption mean values could be attributed to addition agnps, with their hydrophobic nature, so j bagh college dentistry vol. 27(2), june 2015 evaluating the effect restorative dentistry 22 the number of pema molecules which would be available on the surface of the specimen which would allow water diffusion reduced, this is in accordance with arora et al. (27). furthermore, the addition of agnps resulted in decrease of microporosity that resulted after polymerization process and subsequently reducing the water sorption. while for solubility test only (0.2% group) showed a highly significant decrease in solubility. this could be attributed to the decrease in water sorption properties of the soft lining material with the increase in the amount of agnps added, as indicated by this study. this limitation in the diffused water will reduce the possibility of molecular flexibility and the leach out of soluble constituents from the polymer mass. about the shear bond strength, the non significant change that resulted could be explained by the compatibility and high degree of similarity in chemical structure between polymethyl methacrylate denture base material and polyethyl methacrylate soft liner which would result in a chemical bonding between the two materials. however, ftir analysis showed that no chemical interaction was detected between agnps and soft liner. in addition to that the flowability of the soft lining material; which allows the material to readily adapt to the bonding surfaces and creates an intimate union, didn’t seem to change subjectively. color change test results showed that there was a statistically highly significant increase in light absorption percentage with the increase in agnps amount which was added to the soft lining material. this could be explained by the presence agnps in the polymer matrix, as the silver nanoparticles have extraordinary efficient ability to absorb and scatter light due to their optical properties (28), and a single silver nanoparticle can interact with light more efficiently than any known organic or inorganic colored particle with same dimensions (29), so agnps absorb more light energy than polymer matrix and appear more opaque. in addition to that agnps will act as fillers which tend to fill any spaces or voids within the polymer, thereby increasing the amount of scattered and absorbed light by the specimen and decrease the amount of transmitted light. references 1. anusavice k j. phillips' science of dental materials. 11th ed. st louis: mo: elsevier science (usa); 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24(3): 42-46. 22. american society for testing and material, astm d, 638-m standard test method for tensile properties of plastics. philadelphia: american national standards institute,1986. 23. reidy b, haase a, luch a, dawson k a, lynch i. mechanisms of silver nanoparticle release, transformation and toxicity: a critical review of current knowledge and recommendations for future studies and applications. materials 2013; 6: 2295350.(ivsl) 24. cao z, sun x, sun y, fong h. rechargeable antibacterial and antifungal polymeric silver sulfadiazines. j bioact compat polym 2009; 24(4): 350-67. 25. furno f, morley k s, wong b, et al. silver nanoparticles and polymeric medical devices: a new approach to prevention of infection. j antimicrob chemother 2004; 54:1019-24. 26. kumar r, m¨unstedt h. silver ion release from antimicrobial polyamide/silver composites. biomaterials 2005; 26: 2081-8. 27. arora n, jain v, chawla a, mathur v p. effect of addition of sapphire (aluminum oxide) or silver fillers on the flexural streangth, thermal diffusivity and water sorption of heat polymerized acrylic resin. ijprd 2011; 1(1): 21-27. 28. mavani k and shah m. synthesis of silver nanoparticles by using sodium borohydride as a reducing agent. ijert 2013; 2(3): 1-5. 29. evanoff jr. dd, chumanov g. synthesis and optical properties of silver nanoparticles and arrays. chem phys chem 2005; 6: 1221-31. الخالصة كان الغرض من ھذه الدراسة إن عملیة استیطان بطانة طقم االسنان اللینة من قبل المبیضات البیض والكائنات الدقیقة االخرى الیزال یمثل مشكلة جدیة ، :الخلفیة ) ضد المبیضات البیض(على النشاط المضاد للفطریات بالحرارة اللینة لطقم االسنان معالجةھو تقییم تأثیر ادماج الفضة النانویة في مادة التبطین االكریلیكیة ال عالوة على ذلك، تقییم كمیة الفضة المتحررة من مركب البطانة . ،وعلى امتصاص المیاه، قابلیة الذوبان، قوة الربط القصیة والتغیر اللوني لمواد التبطین اللینة .اللینة مع الفضة النانویة تم اعداد اربع %).0.2و% 0.1، % 0.05(نانویة مع مادة التبطین االكریلیكیة اللینة لطقم االسنان بنسب وزنیة مختلفة تم دمج الفضة ال: المواد وطرق البحث تم تقییم نشاط مزیج مادة التبطین اللینة مع الفضة النانویة ضد الفطریات . مائة وعشرین عینة وتم تقسیمھا الى خمس مجموعات وفقا لنوع االختبار المراد اجرائھ وقد تم قیاس كمیة الفضة المتحررة في اللعاب . تعدادالمبیضات البیض القابلة للحیاة واختبار انتشار القرص: على ثالثة فترات مختلفة وباستخدام طریقتین تم تحلیل النتائج و.غیر اللونيالتوقوة الربط القصیة ,قابلیة الذوبان , تم قیاس قابلیة امتصاص الماء . ياالصطناعي بواسطة التحلیل الطیفي لالمتصاص الذر .احصائیا لم یكن ھنالك اي . اظھرت نتائج جمیع المجموعات التجریبیة انخفاضا كبیرا للغایة في عدد مستعمرات المبیضات البیض مقارنة بالمجموعة الضابطة: النتائج اظھرت النتائج ان اضافة الفضة النانویة ادت الى . المتحررة ر للفضةلم یتم الكشف عن اي اث. منطقة تثبیط حول اي عینة في اي مجموعة من مجامیع االختبار تم العثور على اختالفات . فقط انخفاض كبیر جدا في قابلیة الذوبان% 0.2انخفاض ملحوظ بدرجة كبیرة في قابلیة امتصاص الماء، في حین اظھرت مجموعة .زیادة كبیرة جدا في نسبة امتصاص الضوء في جمیع المجموعات التجریبیة غیر ملحوظة في قوة الربط القصیة لجمیع المجموعات، وقد لوحظ لم یتم . یاتان اضافة الفضة النانویة الى مادة التبطین االكریلیكیة اللینة لطقم االسنان یساعد على انتاج مادة تبطین لینة مع خصائص مضادة للفطر: االستنتاج فة عن انخفاض في قابلیة امتصاص الماء ولم تؤثر على قوة الربط القصي لمادة التبطین، في حین ادت الى تغیر وقد اسفرت ھذه االضا. اي فضة متحررةاكتشاف .لون المادة من خالل زیادة التعتیم .الفضة النانویة, النشاط المضاد للفطریات, بطانة طقم االسنان اللینة: الكلمات الرئیسیة hikmat f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 effect of plasma restorative dentistry 6 effect of plasma treatment of acrylic denture teeth and thermocycling on the bonding strength to heat cured acrylic denture base material hikmat j. aljudy, b.d.s., m.sc., ph.d. (1) abstract background: acrylic resin polymer s used in prosthodontic treatment as a denture base material for several decades. separation and debonding of artificial teeth from denture bases present a laboratory and clinical problem affect patient and dentist. the aim of this study is to evaluate the effect of oxygen plasma and argon plasma treatment of acrylic teeth and thermocycling on bonding strength to hot cured acrylic resin denture base material. materials and methods: sixty denture teeth (right maxillary central incisor) are selected. the denture teeth are waxed onto the beveled surface of rectangular wax block according to japanese standard for artificial teeth. the control group consisted of 20 denture teeth specimen without any treatment. the oxygen plasma group consisted of 20 denture teeth specimen treated with oxygen plasma for two minutes exposure time at plasma apparatus. the argon plasma group consisted of 20 denture teeth treated with argon plasma for two minuets exposure time. all the specimens are undergone flasking and wax elimination procedure in the conventional way. all specimens stored in distilled water for 7 days at 37°c, then half of the specimens of all groups undergoes thermocycling between 5°c 55°c in 60 seconds cycles for three days and tested for shear bond strength using universal testing machine the data was collected and analyzed statistically using analysis of variance and independent sample t-test. results: the plasma treated groups showed the higher mean force required to fracture the acrylic teeth from their heat cured acrylic resin denture bases, as compared to control group, and the oxygen plasma treatment group showed higher shear bond value than the argon plasma treatment. the thermocycling had a deleterious effect on bonding strength for control group while the plasma treated group showed an increase in bond strength following thermocycling. conclusion: plasma treatment method was an effective approach for increasing the shear bond strength as a result of surface oxidation and chemical etching effect of oxygen plasma and micromechanical interlocking effect of argon plasma. key words: plasma treatment, shear bond strength, thermocycling, acrylic resin teeth. (j bagh coll dentistry 2013; 25(special issue 1):6-11). introduction acrylic resin denture teeth had been widely used for removable prosthesis construction, principally due to these acrylic teeth ability to be bond chemically to the acrylic resin denture base material, owing to the similar chemical composition and formulation of the materials (1). one of the main advantages of acrylic teeth are their ability to adhesively bonding to acrylic resin denture base material, in spite of that bonding which seems satisfactory, failures are still common and teeth detachment from denture base is one of the frequent complain and repair requirement for conversional prosthodontics, and this resin teeth detachment and fracture are considered to be a tragedy for the patient, whatever his or her age or social position status are being (2). acrylic teeth detachment from the denture, resin material could be attributed to several factors, from these factors is the direction of functional forces ridge lap area which prepared for teeth bonding to base material, contamination of acrylic resin teeth with separating medium or remnant of wax contaminate the bonding surface during wax elimination procedure (3). (1)lecturer. department of prosthodontics. college of dentistry. university of baghdad. on the other hand, attempt to improve artificial acrylic teeth bonding to acrylic denture base that influence on the bonding strength as ridge lap grinding, bonding agents, solvents or monomer / polymer solution application, microwave polymerization, polymerization temperature or cross linking agent concentration (4). one of the most universal surface treatment techniques is the plasma treatment (5). plasma consisted from a partially ionized gas or gas mixture, the charged ions or electrons accelerated in electrical field to the energies that are comparable or exceed bond energies of the polymer surface plasma treatments had been found to improve the hydrophilicity of polymers surface without altering the bulk properties which directly impact their function (6). plasma surface treatments are using gases as oxygen, argon and nitrogen (7). oxygen plasma was reported to improve hydrophobicity and hydrophilicity and induce various functional groups which affect polymer bonding (8). in addition oxygen plasma treatment increased surface energy of polymers (9), while argon plasma treatment of polymers reported to induce cross linking properties of polymers (10). recent studies have been indicated that plasma treatment j bagh college dentistry vol. 25(special issue 1), june 2013 effect of plasma restorative dentistry 7 could increase the bond strength between heat cured and self cured acrylic resins to levels exceeding that obtained with adhesive primer (12, 13), also studies indicated that plasma treatment increased tensile bond strength between soft liner and denture base resin (6,11). from that this study was designated to evaluate the effect of oxygen plasma treatment and argon plasma treatment of acrylic resin artificial teeth and themocylcing on the shear bond strength (sbs) to hot cured acrylic resin denture base material. materials and methods sixty right maxillary central incisor acrylic artificial teeth (florident, china) were selected, and had been waxed onto the beveled surface of rectangular wax block, the slope of the beveled surface aligned each artificial acrylic tooth so that the long axis of the tooth was at a 45° from the base of wax testing block, that would be in accordance to the japanese standard for artificial teeth bonding test (jist) (november 6506, 1989). the conventional flasking technique had been followed for specimen preparation, the two halves of the flask were coated with separating medium (vertx divosep holland) and allowed to dry to be ready for pouring of the stone type iii (elite model, italy) in the lower half of the flask using vibrator to avoid air entrapment. then waxed teeth were loaded in the stone mould before setting of stone in such a way that the waxed denture bases were embedded in the stone only. following stone setting, a layer of separating medium had been used to coat the lower half of the flask; then the upper portion of the metal flask was positioned on top of the lower portion and filled with type iii dental stone with vibration, then wax elimination was done by placing the flask in boiling water for 5 minutes. the flask was opened and washing of the two halves with water and detergent to remove any wax remnant. after dryness the two halves of the flask was coated with separating medium to be ready for packing with acrylic dough. for plasma treatment, the artificial acrylic teeth were removed from the upper half of the flask, and each 10 artificial teeth were tied with upper silk as a ring surrounding the cervical portion of the teeth and the teeth were inserted in plasma apparatus chamber with base of the teeth is toward the plasma source to be exposed to the plasma gas. the exposure time was 2minutes, at 800 volt; 75ma powers of 60 watt, with plasma source were kept 4cm above the teeth specimens (6, 11). according to type of plasma treatment 10 specimens of artificial acrylic teeth were treated with oxygen plasma other 10 specimens of artificial teeth were treated with argon plasma for the same exposure time and distances following plasma treatment. the artificial acrylic teeth were replaced in their position in the upper halves of the flask, a layer of separating medium was placed on the stone of both halves, heat cured acrylic resin(vertex, holland)was mixed according to manufacture recommendation using dry and clean jar using a clean wax knife for 30 second. packing of acrylic dough by rolling the acrylic resin dough with the poly ethylene sheet, the two halves of the flask were assembled and placed under hydraulic press with gradual application of pressure to allow even flow of the dough throughout the mold space, then pressure was relived and the flask opened and the over flowed material surround the mould space were cut with sharp knife and removed. final flask closure was performed by contacting the two flask halves till metal to metal contact had achieved and left under pressure for 5 minute with 20 bars, then flasks were immersed in water bath for 90 minutes at temperature of 73 c° then the temperature was raised to 100 c° and kept boiling for 30 minute then the flasks allowed to slow cooling in a water bath at room temperature before deflasking. the sample were carefully deflasked and cleaned, all acrylic access were removed with an acrylic and then all samples were polished using bristle brush or rouge wheel with pumice and lathe polishing machine. after finishing and polishing, all of the specimens were stored in distilled water at 37 °c for seven days before sbs was tested. half of the experimental specimens were thermocyled using thermocycling device, by subjecting the samples to 60-second cycle for three days at temperature ranging from 5 °c to 55 °c after finishing the thermocycling then all the experimental specimen that were thermocycled or non thermocycled were tested. sbs was measured at a cross head speed of 1.5 mm/min using universal testing machine (hack, germany), with load being applied at 45° from the log axis of each acrylic resin tooth on palatal surface, till fracture was reached. the sbs were calculated based on the fracture force in newton the adhesive surface area in millimeter and converted to megapaskal (mpa). the data had been statistically analyzed. results descriptive statistics include means and standard deviation of sbs in (mpa) of the experimental group showed the higher sbs values in plasma treated groups as compared to the control group and the oxygen plasma treated group indicated the higher sbs than the argon j bagh college dentistry vol. 25(special issue 1), june 2013 effect of plasma restorative dentistry 8 plasma treated group. the analysis of variance (anova) test showed a highly significant difference between plasma treated groups and control group, (table 1, figure1). the least significant difference (lsd) test showed a highly significant difference in sbs values between oxygen plasma group and control group and between argon plasma group and control group, and between oxygen plasma group and argon plasma group, (table 2). effect of thermocycling with the thermocycling anova and lsd showed a highly significant difference in sbs values among the control and the plasma treated groups, (table 1 & 2).the sbs values are higher under thermocycling for both plasma treated groups and the higher value was detected in oxygen plasma group. for control group, thermocycling decrease the sbs values in comparison with the control group without thermocycling, (figure 3). the independent sample t-test used to compare the effect of thermocycling for each experimental group and showed a highly significant difference between each group before and after thermocycling, (table 3). in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 * significant 0.01 ≥ p > 0.001 ** highly significant p ≤ 0.001 *** highly significant table 1: descriptive statistic and anova test of sbs in (mpa) between control and plasma treatment groups with and without thermocycling. state groups descriptive statistics group difference anova test mean s.d. f-test p-value without thermocycling control 2.20 0.02 5101.08 0.000 *** oxygen plasma 9.07 0.06 argon plasma 8.59 0.29 with thermocycling control 2.03 0.07 41304.46 0.000 *** oxygen plasma 9.48 0.06 argon plasma 8.94 0.07 table 2: the lsd test of sbs in (mpa) between control and oxygen plasma and argon treated groups with and without thermocycling. state groups mean difference p-value without thermocycling control oxygen plasma -6.88 0.000 *** argon plasma -6.39 0.000 *** oxygen plasma argon plasma 0.49 0.000 *** with thermocycling control oxygen plasma -7.46 0.000 *** argon plasma -6.92 0.000 *** oxygen plasma argon plasma 0.54 0.000 *** figure 1: sbs in (mpa) of all experimental groups with and without thermocycling. j bagh college dentistry vol. 25(special issue 1), june 2013 effect of plasma restorative dentistry 9 table 3: differences in sbs in (mpa) in each experimental group under the effect of thermocycling groups state descriptive statistics state difference mean s.d. t-test p-value control without thermocycling 2.20 0.02 7.66 0.000 *** with thermocycling 2.03 0.07 oxygen plasma without thermocycling 9.07 0.06 -15.75 0.000 *** with thermocycling 9.48 0.06 argon plasma without thermocycling 8.59 0.29 -3.77 0.001 *** with thermocycling 8.94 0.07 figure 2: comparison of the effect of thermocycling on sbs in (mpa) in each experimental group. discussion in clinical practicing, the ability of artificial teeth to resist debonding from denture during masticatory stresses is of paramount importance for successful prosthodontic treatment and patient's confidence in removable prosthesis, since the bond failures between tooth and denture base represent a problem for rehabilitation success (16, 17). in order to minimize these failures, several approach being used for enhancement of bonding strength between acrylic teeth and the resin base. it had been demonstrated that the type of acrylic resin teeth, method of polymerization, tooth surface treatments and conditioning and the thermal stress can influence the resin/tooth bond strength (3, 14, 15, 18). one of the fast and efficient methods for improving bonding properties of artificial acrylic teeth to heat cured resin denture base material is the plasma surface treatment techniques. according to the results of the present study, both types of oxygen and argon plasma showed an improvement in sbs and bonding ability of acrylic resin teeth to heat cured acrylic resin denture base materials, and the hypothesis of if oxygen and argon plasma could provide more retention against debonding of artificial teeth from heat cured denture base materials was accepted. effect of oxygen plasma treatment of acrylic teeth the oxygen plasma treatment of artificial acrylic teeth showed a highly significant difference with control group in the values of sbs, (table 1). effect of oxygen plasma treatment of artificial acrylic teeth on bonding strength to heat cured acrylic resin denture base material could be explained on the bases of oxygen plasma produce oxidation reactions on the basal surface of acrylic teeth, this oxidation reaction allowing the introduction of oxygen containing group of carbonoxygen single bond (c-o) and carbon oxygen double bond (c=o) on to the polymer of j bagh college dentistry vol. 25(special issue 1), june 2013 effect of plasma restorative dentistry 10 acrylic teeth surface, due to high reactive property of oxygen plasma (6). as a result of oxygen containing groups the surface hydrophilicity of the plasma treated teeth will be improved (19), allowing the denture base resin to be penetrated into artificial teeth resin resulting in improvement in bonding strength. inaddition, oxygen plasma treatment of artificial teeth producing an increase in surface area of polymer by removal of surface material and producing a rough surface, this rough surface will contribute in more intimate contact between teeth polymer and heat cured denture base polymer which in turn resulting in further bonding strengthening (6, 11). these findings of present study come with zhang et al (6) and massod and mohamed (11) findings in bond strength improvement with oxygen plasma treatment. effect of argon plasma treatment of acrylic teeth the argon plasma treatment of artificial acrylic teeth showed a highly significant difference with control group in the values of sbs, (table 1). this highly significant difference may be attributed to the effect of argon gas particles which specified by high molecular weight and as being hit the acrylic teeth polymer surface, physical removal of polymer surface material due to high energy and enhance micromechanical interlocking and inducing crosslinking properties of polymer with denture base polymer leading to highly significant bond strengthening with the denture base material, as compared to the control group. this result is in agreement with chan et al (5) and massod and mohamed (11). difference in sbs between oxygen plasma and argon plasma acrylic teeth treatment the findings of the present study indicating that oxygen plasma treatment of acrylic teeth is highly significant in sbs values in comparison with argon plasma (table 1). this could be explained by the oxygen plasma had double effect on the surface of acrylic teeth; the first is the oxidation reaction and introduction of oxygen containing group and the second effect is the surface etching and roughing which in turn increase the surface area of polymer treated to bond to other polymer area. while the argon plasma had micromechanical interlocking and crosslinking properties which improve bonding strength of acrylic teeth to denture base material (5, 6, 11). effect of thermocycling for control group, the sbs between the acrylic teeth and acrylic denture base was decreased after thermocycling, (table 3). this could be explained on the bases of hydration of specimen leading to development of voids between the acrylic teeth and their denture bases, these voids will affect significantly on bonding strength resulting in decrease in sbs since the water absorbed by polymer material resulting in stress buildup at the interface area between teeth and denture base due to swelling of the voids with thermocycling procedure (20, 21, 23). while the effect of thermocycling on plasma treated group is appositive effect leading to highly significant difference in sbs values compared with control group, (table 2). this improvement in bonding ability explained by plasma treatment introduce element into the treated surfaces of acrylic resin teeth without thermodynamic constraints, radical are created in plasma zone play an important role in implantation process these facts are combined with ability of plasma to convert polymer from hydrophobic to hydrophilic which in turn improve the adhesion strength since the thermocycling process lead to hydration of the specimen (12, 13, 19, 22, 24). the results also indicated that the oxygen plasma had higher bond strength after thermocycling than the argon plasma, (table 3). this high significant difference in sbs values could be cleared by implantation of radical will be in combination with oxidation and surface roughing in oxygen plasma while the argon plasma will lead to micromechanical interlocking combined with implantation of radical after hydration in thermocycling procedure (19). as conclusions • plasma treatment method was an effective approach for increasing the sbs as a result of surface oxidation and chemical etching effect of oxygen plasma and micromechanical interlocking effect of argon plasma. • oxygen plasma treatment showed greater effect on the sbs than the argon plasma treatment due to the double effect of oxidation and etching on the surface of acrylic teeth. • thermocycling showed an increase in bonding strength following plasma treatment. j bagh college dentistry vol. 25(special issue 1), june 2013 effect of plasma restorative dentistry 11 references 1consani rl, naoe ht, mesquita mf, sinhoreti ma, mendes wb. effect of ridge-lap surface treatments on the bond of resin teeth to denture base. j adhes dent 2011; 13(3):287-93. 2stoia ae, sinescu c, pielmusi m, enescu m,tudor a, rominu ro, rominu m. tensile testing, a method used to demonstrate the effect of organic solvents on acrylic teeth denture base resin bond strength. international j of biology and biomedical engineering 2011; 5 (1):9-17. 3chaves c al, regis rr, machado al, souza rf. effect of ridge lap surface treatment and thermocycling on microtensile bond strength of acrylic teeth to denture base resins. braz dent j 2009; 20 (2): 121-31. 4bragaglia le, prates lh, calvo mc. the role of surface treatments on the bond between acrylic denture base and teeth. braz dent j 2009; 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(ivsl) 16kamposiora p, papadopoulos t, papavasiliou g, sarafianou a, tzanakakis e. a qualitative evaluation. denture base resin-acrylic tooth bond. j dent techol 2009; 30-5. 17saavedra g, neisser mp, sinhoreti mac, machado c. evaluation of bond strength of denture teeth bonded to heat polymerized acrylic resin denture bases. braz j oral sci 2004; 3(9):45864. 18chatterjee n, gupta tk, banerjee a. a study on effect of surface treatments on the shear bond strength between composite resin and acrylic resin denture teeth. j indian prosthodont soc 2011; 11(1):20–25. 19lai j, sunderland b, xue j, yan s, zhao w, folkard m, michael bd, wang y. study on hydrophilicity of polymer surfaces improved by plasma treatment. appl surf sci 2006; 252(10): 3375-9. 20schneider rl, curtis er, clancy jms. tensile bond strength of acrylic resin denture teeth to a microwave or heat-processed denture base. j prosthet dent 2002; 88 (2):145-50. (ivsl) 21elias cn, henriques fq. effect of thermocycling on the tensile and shear bond strength of three soft liners to a denture base resin. j appl oral sci 2007; 15(1):18-23. 22chu pk, chen jy, wang lp, huang n. plasmasurface modification of biomaterials. mater sci eng r 2002; 36:143-206. 23cunningham jl. shear bond strength of resin teeth to heat-cured and light-cured denture base resin. j oral rehabil 2000; 27:312-6. (ivsl) 24bismarck j, springer. wettability of materials: plasma treatment effects, in encyclopedia of surface and colloid science, p somasundaran, ed., taylor & francis, new york, 6592 (2006). j bagh college dentistry vol. 31(4), december 2019 oral health in 46 oral health in relation to nutritional status among 10 years old primary school children in al-hillah city/ iraq sarah y. al khafaji, b.d.s.(1) nadia aftan al rawi, b.d.s., m.sc., ph.d. (2) abstract background: oral health and nutrition are in interdependent relationship that good nutritional health enhancing good oral health. nutrition can affect the development and integrity of oral cavity and the progression of oral disease. the aim of the present study was to assess the prevalence of the gingival health condition in relation to the nutritional status, among 10 years old primary school children in urban and rural area in al-hillah city. material and method: eight hundred ninety one (891) students, aged10 years old, selected randomly from different primary schools, in urban and rural area in al-hillah city, were included in this study. oral examination including of plaque index assessment, which was done according to the criteria by silness and loe, in 1964, gingival health conditions was determined according to loe and silness, 1963. nutritional status was assessed using body mass index (bmi), following the criteria of centers for disease control and prevention growth chart (cdc). statistical analysis was done using kruskal wallis test, mann-whitney u test and anova, p-value of < 0.05 was considered as statistically significant. results: this study showed that the majority of the sample was found to be with normal gingival health condition. no significant difference was observed between the gingival index in relation to gender, or residence also, no significant result was found, between plaque and gingival index in relation to the nutritional status. conclusion: the majority of the sample with normal gingiva however the nutritional status had no significant effect on gingival health condition while the urbanization had an effect on oral hygiene keywords: children, condition, nutritional, oral hygiene. (received: 15/8/2018; accepted: 1/10/2018) introduction dental plaque is a non-mineralized soft bacterial deposit, which form and adhere firmly to the tooth (1). the accumulation of plaque enhanced gingivitis (2). gingivitis is described as an inflammation of the marginal gingival tissues with no detectable loss of bone or connective tissue attachment, caused by local irritation of substances derived from microbial plaque accumulating on and near the cervical region of the teeth(3). in most children, the process of gingival inflammation remains superficial (2,4,5). the role of diet and nutritional factors in the development of periodontal diseases remain vague, although adequate diet is important nutritionally to maintain host resistance and maintain the integrity of the periodontal tissues, but many recent studies failed to find an association between nutritional status and periodontal disease (6). malnutrition can increase the susceptibility to periodontal disease directly or in directly: by forming changes in the supporting soft tissue structures and by differences in the functional ability of saliva that will lead to alterations in the differentiation, development and maturation of gingival margin, attachment epithelia, periodontal 1. m.sc. student, department of pedodontics and preventive, dentistry, college of dentistry, university of baghdad. 2. assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad membrane and alveolar bone(7). some of previous iraqi studies addressed the prevalence of gingivitis and their relation to nutritional status (815). al-galebi in 2011 reported higher percentage for the moderate amount of plaque in alnassiyria governorate (11). al-awadi in 2016 reported that, the higher percentage of the children (79.5%) demonstrated amount of plaque scores between 1.1-2 in al-dewaniyia governorate (12). however other iraqi studies were found no significant difference between males and females concerning plaque index such al-galebi, el-samarrai, hassan, and droosh (11-15). al-galebi in 2011 reported moderate type of gingivitis among 9 -10 years –old in al-nassiyria city (11). as far as there is no previous iraqi study concerning the assessment of oral health condition in relation to nutritional status among children aged 10 years old in al-hillah city this study was conducted. materials and methods eight hundred ninety one (891) children aged ten years old were selected randomly from different rural and urban primary schools in alhillah city. according to the division of general directorate of education of al-hillah city, which classified the primary schools into urban schools that were located in the center of the city and rural schools that were located in the neighboring villages. the cross sectional random sample was calculated form the prevalence of previous studies by the formula as n=zp2 (1-p)/ (d) 2 (16). n= sample size. j bagh college dentistry vol. 31(4), december 2019 oral health in 47 z=z statistics for the level of the confidence (at 95% confidence level, z=1.96). p= prevalence of the proportion. d=precision (if the precision is 5%, d=0.05). this study was done during the period from december 2018 to february 2019. a pre-study ethical approval was assigned, approval was taken from the general directorate of education of alhillah city in order to achieve subject without obligation, also the children's parent consent form that was taken before starting the study. inclusion criteria: the selected students were with: • no history of medication, (antiinflammatory or antimicrobial therapy) within previous 3 months. • no history of orthodontic treatment. • no history of any systemic disease. oral examinations were performed according to the criteria of who, 1997 (17) that are the examination of the children done in an arranged area for maximum efficiency and cooperation. the most comfortable situation for the children was the sitting on a chair and the examiner standing behind the children's head as well as facing the opening through which sunlight enters as source of light for get good illumination. the instruments were used: plane mouth mirror; several pairs of tweezers; containers; gauze; periodontal probe; towel. plaque index assessment was done using silness and leo (18). the six index teeth were selected to represent whole dentition, the examination started with buccal surface following by mesial, lingual and distal surfaces . according to fdi (19) teeth numbering system, these teeth are: 16, 12, 24, 36, 32, and 44 for permanent and 55, 52, 64, 75, 72, and 84 for primary teeth. only fully erupted teeth were included and if the indexed tooth was missing or partially erupted, it was not replaced by the adjacent tooth. gingival condition was assessed using gingival index according to loe and silness(20). the examination sequence was similar to that of used for the dental plaque. nutritional status was assessed according to body mass index (bmi) indicator by using anthropometric measurement (weight and height) then followed the criteria of centers for disease control and prevention growth chart (cdc)(21). children were weighted by a bathroom scale (22). from the child's weight and height, bmi index determined according to this formula (22): body weight / (height) 2 = bmi kg/m2 the result of that formula was compared with the international reference values using cdc growth charts (21). statistical analysis was performed using spss® software (version 23.0 for linux®). the statistical tests were used: student's t-test; anova; mann-whitney u test; kruskal wallis h test, p-value of < 0.05 was considered as statistically significant. results this study included a total of (891) school children aged (10) years, boys and girls constituted close proportions, with boys forming (50.28%) while girls (49.72%). children living in urban areas constituted (57.58%) of the study sample, while the remaining (42.42%) children lived in rural areas, as illustrated in figure (1). table (1) illustrates distribution of the total sample between the residences table 1: distribution of the children according to gender by residency figure 1: residence of the sample table (2) demonstrates the mean value and standard error of plaque concerning both genders. plaque evaluation was found to be even in both gender. no significant difference in plaque index was observed between boys and girls. student's ttest was used because the data was normally distributed. table 2: plaque index (mean and standard error) by gender gender plaque index t-test p-value mean se boy(no.=448) 0.69 0.04 0.71 0.475 girl(no.=443) 0.72 0.04 total(no.=891) 0.70 0.03 table (3) demonstrates the mean value and standard error of plaque index concerning place residence gender no. (%) total no. (%) boys girls urban 249 (55.58%) 264 (59.59%) 513 (57.58%) rural 199 (44.42%) 179 (40.41%) 378 (42.42%) total 448 (100%) 443 (100%) 891 (100%) j bagh college dentistry vol. 31(4), december 2019 oral health in 48 of residence. plaque evaluation was found to be significantly higher in rural than urban area with a statistical significance. table 3: plaque index (mean and standard error) by residence. residence plaque index t-test p-value mean se urban (no.=513) 0.60 0.03 4.78 < 0.001 rural (no.=378) 0.84 0.05 table (4) demonstrates the mean value and standard error of plaque evaluation among children in regarding to the nutritional status. there was no statistical significant difference in plaque index value among the different categories of nutritional status. table 4: plaque index by nutritional status. nutritional status plaque index anova f value p-value mean se underweight (< 5th percentile) (no.=45) 0.67 0.11 1.37 0.252 normal (5th-85th percentile) (no.=594) 0.74 0.03 overweight (85th-95th percentile) (no.=134) 0.65 0.06 obese (> 95th percentile) (no.=118) 0.61 0.06 table (5) demonstrates the prevalence of gingival inflammation and the distribution of children according to the severity of gingivitis. the majority of the sample was found to be with normal gingival condition followed by the mild type while the moderate and sever type were the lowest percentage. table 5: distribution of the children according to the severity of gingivitis. severity of gingivitis no. % normal 720 80.81% mild 138 15.49% moderate 31 3.48% severe 2 0.22% table (6) demonstrates the mean values and standard error of gingival condition concerning both of gender and place of residency. in this table z score was used because the variables were not normally distributed. no significant relationship was observed between gingival index and any of gender, or residence. mann-whitney u test was used. table 6: gingival index by gender and residence. variable gingival index z pvalue mean se gender boys 0.10 0.01 0.44 0.662 girls 0.09 0.01 residence urban 0.10 0.01 0.61 0.542 rural 0.10 0.01 table (7) demonstrates the mean values and standard deviation of gingival condition in regarding to nutritional status. differences were statistically not significant between the nutritional status and the gingival index p-value (0.478). kruskal wallis h test was used. table 7: gingival index by nutritional status. nutritional status gi mean ± sd kruskal wallis h p value underweight (< 5th percentile) 0.09 ± 0.27 2.49 0.478 normal (5th-85th percentile) 0.10 ± 0.46 overweight (85th-95th percentile) 0.10 ± 0.34 obese (> 95th percentile) 0.09 ± 0.30 discussion periodontal status of children was determined by using gi in this study. while pi determined the presence and the amount of the visible plaque accumulating on the supragingival area(18), gi determine the extent and severity of gingival inflammation based on the assessment of the gingival color, contour and bleeding(20). the mean of plaque index in this study was less than that reported by al-galebi in 2011(11); with matching age and also lower than other studies (10, 8, 23, 24) but higher than that that reported by alsadam in 2013(8). these variations might be due to the differences in the sample size, residency (urban or rural), and knowledge. rural children showed a significantly higher mean of plaque index than that found among the urban j bagh college dentistry vol. 31(4), december 2019 oral health in 49 children, this was in agreement with the findings of the other studies (8,9,25,26). the result reflected the presence of poor oral hygiene among the rural children, which could be due to the low awareness level and the less use of oral hygiene aids in rural area than the urban one (27). in present study, there was no significant difference between boys and girls concerning of plaque index and this was in agreement with other studies (12-15). however, other studies (8,23.28-34,12) found that boys had statistically higher plaque index than girls. this difference could be due to the effect of many factors like; diet, oral hygiene, age, secretion of salivary gland could be effect on the amount of dental plaque, therefor the amount of plaque was vary among the individuals (4,35,36). result in this study showed that the prevalence of gingivitis was lower than that reported by previous iraqi studies (11,12,15). it was assured that dental plaque is the main etiological factor for gingivitis (37). in the present study, no significant difference was recorded for the gingival index among the nutritional status grades as well as gender, which could be attributed to the absence of the significant difference in plaque index; this finding was in agreement with that of al-sadam in 2013(9). this may be related to that oral health problem is a multifactorial disease, including poor oral hygiene, dealing with tooth brush, frequencies visiting to the dentist, and diet (39). coniclusion: a largest percent of children had normal weight and healthy gingiva; there was no significant relation between the gingival index and the nutritional status of children while urbanization had significant effect on plaque index references 1. dumitrescu a. etiology and pathogenesis of periodontal disease. new york: springer. 2010. 2. mooder t, wondimu b. periodontal diseases in children. health dentistry. 2008;68:70-75. 3. damle s. text book of pediatric dentistry. 3rd ed. darya ganj, new delhi. 2009. 4. okada k, kato t, ishihara k. involvement of periodontopathic biofilm in vascular diseases.oral diseases. 2004;10:5-12. 5. hiremath v, mishra n, patil a, sheetal a, kumar s. prevalence of gingivitis among childrenliving in bhopal. journal of oral health and community dentistry. 2012;6(3):118-120. 6. moynihan p. the role of diet and nutrition in the etiology and prevention of oral disease.bulletin of the world health organization. 2005;83(9):694-699. 7. marshall t. caries prevention in pediatrics: dietary guidelines. quintessence international. 2004;35(4):332-335. 8. al-azawi l. oral health status and treatment needs among iraqi five-year old kindergartenchildren and fifteen-years old students (a national survey). ph.d. thesis submitted to college of dentistry, university of baghdad. 2000. 9. al-sadam n. oral health status in relation to nutritional and social status in kerbal'agovernorate for primary school students aged 12 years old. master thesis submitted to the college of dentistry, university of baghdad. 2013. 10. liath n, al-rawi n. oral health status relation to nutritional status among a group of 13-15 years old intermediate school girls in al-najaf city in iraq. master thesis submitted to the college of dentistry, 11. al-ghalabi s. oral health status and treatment need in relation to nutritional status among 9-10 year-old school children in nassirya city/iraq. master thesis submitted to college of dentistry, university of baghdad. 2011.university of baghdad. 2016. 12. al-awadi z. oral health status relation to nutritional status among a group of 9 years oldschool children in al-diwaniyah city in iraq. master thesis submitted to the college of dentistry, university of baghdad. 2016. 13. el-samarrai s. oral health status and treatment needs among preschool children. master thesissubmitted to college of dentistry, university of baghdad. 1989. 14. hassan z. oral health status and treatment needs among institutionalized iraqi children and adolescents in comparison to school children and adolescents in iraq. master thesis submitted to the college of dentistry, university of baghdad. 2002. 15. droosh m. protein-energy malnutrition in relation to oral health condition among 6 and 9 years old primary school children in sulaimania city in iraq. master thesis submitted to college of dentistry, university of baghdad. 2007. 16. daniel w. biostatistics: a foundation for analysis in the health science. 7th ed. new york: john wiley and sons. 1999. 17. world health organization (who). oral health survey, basic method. geneva, switzerland.1997. 18. silness p, loe h. periodontal disease in pregnancy. acta odontologica scandinavica. 1964;22:121-135. 19. fdi two-digit notation archived at the wayback machine, hosted on the fdi world dental federation website. page accessed april 1, 2007. 20. loe h, silness j. periodental disease in pregnancy. acta odontologica scandinavica. 1963;21:533-551. 21. centers for disease control and prevention (cdc). clinical growth charts. national centerfor health statistics in calibration with the national center for chronic disease prevention and health promotion. 2000. 22. world health organization (who). the management of nutrition in major emergencies. worldhealth organization; 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25(1):114-119. albander j, rams t. global epidemiology of periodontal diseases an overview. periodontal. 2002;29:7-10 الخالصة جيدة. التغدية لها تاثير على تطور و سالمة التجويف الفمي فمال صحة عنى الحالة الغدائية الجيدة تجعلالتغدية وصحة الفم هما عالقة متازرة بم خلفية الموضوع: سنوات في 10االبتداية العمار وكداللك تفاقم امراض الفم الهدف من الدراسة الحالية هو تقيم الحالة الصحية لاللتهاب اللثة وعالقتها بالحالة الغدائية الطفال مدارس مدينة الحلة في العراق مدارس االبتدائية الريف والحضر في مدينة الحلة .يتظمن فحص الفم بتقيم الصفيحة طالب بعمر العشر سنوات عشوائيا من مختلف 891ر المواد والطرق: تم اختيا ت الحالة الغدائية تم تقيمها باستخدام القياسا loe and silness, 1963 ..وتم تشخيص الحالة الصحية لللثة حسب silness and loe, 1964الجرثومية حسب software ®spss التي استخدمت هي: االختبارات االحصائية(.2000عام )الجسمية وفقا للرسم البياني للنمو تابعة لمراكز السيطرة عن االمراض والوقاية منا whitney u test; kruskal wallis h test.-test; anova; mann-). student's t®(version 23.0 for linux من العينة لية من االطفال لديهم الصفيحة الجرثومية كانت النتجة بفارق معنوي في اطفال الريف مقارنة باطفال مدارس المدن وايضا نسبة الريئسيةالنتيجة:نسبة عا فال.كانت لديهم صحة اللثة جيدة.لم تسجل أي فروق معنوية بين التهاب اللثة وكال من المكان المعيشة ونوع الجنس والحالة الغدائية لالط االستنتاج:نسبة عالية من االطفال لديهم اوزان طبيعة وهدا دليل على تطورالحالة الغدائية في مدينة الحلة . ateka.doc j bagh college dentistry vol. 28(1), march 2016 the salivary pedodontics, orthodontics and preventive dentistry 138 the salivary inflammatory biomarkers (interleukin-6, c reactive protein) in relation with caries-experience among a group of 12 year old obese boys ateka r. aziz, b.d.s. (1) ahlam t. mohammed, b.d.s., m.sc. (2) abstract background: obesity and dental caries are multifactorial diseases related to poor eating habits and show a close relationship with the sociodemographic characteristics of individuals presenting these diseases. this research aimed to investigate the severity of dental caries among group of obese boys aged 12 year in relation to salivary interleukin6 (il-6) and c-reactive protein (crp) of unstimulated whole saliva in comparison with normal weighted boys of the same age. materials and methods: the study group included 40 obese boys, with an age of 12 year. the control group included 40 normal weighted boys of the same age. the total sample involved for nutritional status assessment using body mass index specific for age and gender according to cdc growth chart (2000). the diagnosis and recording of dental caries conducted by using (d1-4mfs and d1-4mfs) index according to the criteria of muhlemann (1976). the collection of unstimulated whole saliva was performed under standardized condition. salivary samples were chemically analyzed for measuring il-6 and crp. results: the caries experience among study group was lower than that among control group for both dentitions, with significant differences for d2, ds and dmfs and highly significant difference for d4. salivary inflammatory biomarkers (il-6, hs-crp) were slightly higher among study group compared with control group with no significant difference between them. salivary il-6 and hs-crp were negatively correlated with dental caries of both dentitions among study group with significant correlation between il-6 and d2, while they were correlated positively with dental caries of both dentitions among control group with highly significant correlation between il-6 and d3 and significant correlation between il-6 and d4. conclusion: obesity and dental caries are associated with increased levels of salivary interleukine-6 and c-reactive protein, this making both obesity and dental caries as a state of inflammation that exacerbating immune responses in the body. key words: obesity, salivary cytokines, interleukine-6, c-reactive protein. (j bagh coll dentistry 2016; 28(1):138-142). introduction obesity in adolescents and children has raised to significant levels globally with serious public health consequences. in addition to cardiovascular, emotional and social issues, it poses a serious hazard to the basic health care delivery system (1). it is associated with an increased risk of morbidity and mortality as well as reduced life expectancy (2). dental caries is a process that may take place on any tooth surface in the oral cavity where dental plaque is allowed to develop over a period of time (3). according to mathus-vliegen et al., (4) obesity is related to several aspects of oral health, including dental caries. dental caries and obesity are multifactorial diseases related to poor eating habits and show a close relationship with the sociodemographic characteristics of individuals presenting these diseases. cytokines are small regulatory proteins that are released in a wide variety of cells to modulate cell–cell interaction and other functions especially important for inflammation and immune responses (5). (1) master student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. some of these cytokines are proinflammatory (make disease worse such as il-1, tnf, il-6). il-6 is produced by adipocytes, monocytes, macrophages, lymphocytes and fibroblasts and stimulates t cell proliferation, activation, apoptosis and cytotoxicity. besides activating the immune system, the increase in il-6 induces hepatic synthesis of acute phase proteins and increases the activity of the hypothalamicpituitary-adrenal axis, altering metabolic responses (6). in obesity, il-6 secreted in an endocrine manner in proportion to the expansion of fat mass particularly in the abdominal region, with a corresponding increase in hepatic production of crp (7). obesity is associated with elevated levels of il-6 (8) and crp (9,10). as well as, dental caries associated with elevated levels of il-6 (11,12) and crp (13). materials and methods: the study group included 40 obese boys aged 12 years were randomly selected from primary schools in al-najaf city, the control group included 40 normal weighted boys were chosen from the same class matching in age with study group. anthropometric measurements included measurement of weight and height according to trowbidge (14) using bathroom scale and height j bagh college dentistry vol. 28(1), march 2016 the salivary pedodontics, orthodontics and preventive dentistry 139 measuring tape. body mass index (bmi) is a number calculated from person`s weight and height, according to this formula bmi (kg/m2) = body weight (kg)/ (height)2 (m) according to specific chart (cdc growth chart) that was used to indicate bmi according to age and gender and identify the obesity at or above 95 percentile while the normal weight between 5-85 percentile (15). caries experience was recorded according to decayed, missing and filled index (dmfs, dmfs for permanent and primary teeth respectively) using the criteria of muhlemann (16) which allow recording decay lesion by severity. the collection of unstimulated salivary samples was performed under standard condition following instruction cited by navazesh and kumar (17). salivary inflammatory biomarkers were interleukin-6 and high sensitive c-reactive protein which analyzed by enzyme linked immuno sorbent assay (elisa) test using special kits according to the manufactured instructions. data analysis was conducted by application of spss program (version 16). results the result of present study showed that the mean dmfs for study group was lower than that of control group, but the difference was not significant. table 1 illustrates dmfs and its components and ds grades among study and control groups. table 1 reveals that d2 was significantly lower among study group compared with control group. caries experience for primary dentition showed in table 2, which reveals dmfs, dmfs components and ds grades; dmfs was significantly lower among study group compared with control group with significant difference for ds component, as well as d4 was highly significantly lower among study group compared with control group. table 3 demonstrates salivary inflammatory biomarkers among study and control groups. it reveals that il-6 was higher among study group compared with control group with no significant difference. it was also found that there is no significant difference between the study and control groups regarding hs-crp. correlation coefficients between salivary inflammatory biomarkers and caries experience among study and control groups are shown in table 4 which reveals that il-6 and hs-crp were correlated inversely with dental caries of both dentitions (dmfs/dmfs) among the study group while they were correlated positively with dental caries of both dentitions among the control group; although the differences were not significant. also il-6 was negatively significantly correlated with d2 among the study group, while it was correlated positively highly significantly with d3 among the control group. concerning primary dentition, il-6 was positively significantly correlated with d4 among the control group. table1: caries experience of permanent dentition (dmfs, dmfs component and ds grades) between study and control groups variables study group control group statistical test mean ± sd mean ± sd t-test p-value d1 d2 d3 d4 0.68 2.55 0.30 0.75 1.35 2.75 0.65 1.98 0.33 4.10 0.58 0.50 0.76 3.04 1.01 1.45 -1.42 2.39 1.44 -0.64 0.15 0.01* 0.15 0.52 ds 4.28 3.94 5.50 3.78 1.42 0.15 ms 0.13 0.79 0.13 0.79 0.00 1.00 fs 0.05 0.22 0.18 0.68 1.11 0.26 dmfs 4.45 3.95 5.80 4.05 1.51 0.13 *significant (p<0.05), d.f=78 j bagh college dentistry vol. 28(1), march 2016 the salivary pedodontics, orthodontics and preventive dentistry 140 table 2: caries experience of primary dentition (dmfs, dmfs component and ds grades) between study and control groups variables study group control group statistical test mean ± sd mean ± sd t-test p-value d1 d2 d3 d4 0.03 0.35 0.13 0.33 0.16 1.00 0.65 1.12 0.00 0.40 0.35 1.65 0.00 1.17 0.74 2.78 -1.00 0.20 1.45 2.79 0.32 0.83 0.15 0.00** ds 0.83 2.09 2.40 3.82 2.28 0.02* ms 0.25 1.10 0.38 1.33 0.45 0.64 fs 0.05 0.32 0.05 0.32 0.00 1.00 dmfs 1.13 2.44 2.83 4.46 2.11 0.03* *significant (p<0.05), **highly significant (p<0.01), d.f=78 table 3: salivary (il-6 and hs-crp) between study and control groups variables study group control group statistical value mean ± sd mean ± sd t-test p-value interleukine-6 56.25 10.54 55.13 13.61 -0.41 0.68 high sensitive c-reactive protein 0.75 0.22 0.75 0.27 -0.02 0.97 d.f=78 table 4: correlation coefficients between salivary (il-6 and hs-crp) and caries experiences (dmfs, ds grades, dmfs and ds grades) variables il-6 hs-crp study group control group study group control group r p r p r p r p d1 d2 d3 d4 dmfs 0.24 -0.31 -0.28 -0.10 -0.15 0.12 0.04* 0.07 0.53 0.33 -0.18 0.02 0.47 -0.08 0.02 0.25 0.90 0.00** 0.59 0.89 -0.03 -0.07 -0.00 -0.13 -0.07 0.85 0.64 0.96 0.42 0.63 0.00 0.05 -0.02 0.21 0.12 0.98 0.72 0.90 0.19 0.44 d1 d2 d3 d4 dmfs -0.18 0.00 0.25 -0.1 -0.04 0.25 0.99 0.11 0.42 0.79 -0.08 0.02 0.04 0.07 0.58 0.89 0.03* 0.66 -0.01 0.00 -0.10 -0.05 -0.04 0.93 0.98 0.50 0.71 0.78 0.05 -0.02 0.01 0.03 0.75 0.85 0.91 0.81 *significant (p<0.05), **highly significant (p<0.01) discussion the present study revealed a low caries experience among obese group compared with normal weight group for both dentitions; this goes in accordance with previous studies (18-20). the low caries experience among study group could be attributed to that the obese subjects were reported to consume more fast foods (21,22) and these fast foods contain unacceptable high levels of fats. fats were found to reduce dental caries through a variety of mechanisms: fats may form a protective barrier on enamel by coating it and thus making it difficult for penetration of acids. in addition, fats replace the carbohydrate intake thereby reducing its intake; also some fatty acids have antimicrobial effects as it inhibits glycolysis in human dental plaque and it coats the plaque to prevent reduction of fermentable carbohydrate to acids (23). additionally, high level of fat in the diet binds to the sugars content of it thus reducing their solubility, resulting in a lower drop in ph and weaker acid attack (24). another cause for lower caries experience among study group is that the mean of plaque index in the present study was lower among the study group than that among the control group with no significant difference between them, as the plaque is the primary etiologic factor for the most frequently occurring oral diseases, dental caries and periodontal diseases (25,26). also the present study showed that salivary phosphorus was higher among the study group than that among the control group with no significant difference between them, the same result was found in the study of hartman et al (27), so due to its cariostatic action and its role as a buffer and in j bagh college dentistry vol. 28(1), march 2016 the salivary pedodontics, orthodontics and preventive dentistry 141 remineralization of the teeth (28), this may lead to low caries experience among the study group. the results of current study revealed that the concentration of salivary interleukine-6 among study group was higher than that among control group with no significant difference between them; this result was in agreement with quelletmurin et al (29). the explanation for this result could be that the effect of obesity related inflammation which is the characteristic feature of the study group. results also showed that there was no significant difference between the study and control groups concerning salivary c-reactive protein level, although some studies revealed elevated level of c-reactive protein in obese compared with normal weight subjects (29-31). the explanation for this result could be the presence of a state of inflammation in both of study and control groups; represented by obesity in the study group where salivary crp concentration has been found to correlate well with serum concentrations (32), and dental caries in the control group as reported by gawri et al., (13) who found that there is a significant relation between level of salivary c-reactive protein and dental caries. data analysis of the present study found that, in the control group, interleukin-6 (il-6) was correlated positively with dental caries for both dentitions with no significant difference; this correlation was highly significant with d3 and significant with d4. the same also reported by(11, 12). the explanation for this result was that the cells in the odontoblast layer initiate immunologic responses of the tooth to dental caries through proinflammatory cytokine and chemokine signaling, in the presence of bacteria, odontoblasts secrete various chemotactic cytokines for neutrophils, monocytes/macrophages, immature dendritic cells, and lymphocytes (33), the migratory immune cells, in particular monocytes/ macrophages, release a large amount of pro-inflammatory cytokines such as il-1β, tnf-α, il-6, and il-12, which regulate inflammatory reactions in the tissue (34). studies of matsushima et al., (35) and wisithphrom and windsor (36) suggest that the glycoprotein which was purified from lactobacillus casei (gram-positive bacteria frequently isolated from deep carious lesions and suspected to be a pathogen of pulpitis) stimulate il-6 production in a timeand dose-dependent manner. data analysis of the present study found that, in the study group, il-6 was correlated negatively with dmfs and dmfs with no significant differences. this may be attributed to the presence of other factors affecting the caries process like type of diet and oral hygiene, as dental caries is a multifactorial disease, or it may be explained partly by that the functional response of odontoblasts to caries is recognized as extending a barrier to the spread of infection by forming reparative dentine, so that odontoblasts attenuating carious infections thereby limiting the inflammatory changes within odontoblasts and maintaining the pulp in a relatively protected environment (37). the hs-crp was negatively correlated with dental caries of both dentitions (dmfs/dmfs) in the study group, and these correlations were not significant.regarding the control group, hs-crp was found to be correlated positively with dental caries for both dentitions (dmfs/dmfs). this result was in agreement with the study of horst et al., (37) and gawri et al., (13) who found that increasing crp in the odontoblast of carious teeth. one can explain that by the presence of il6 which is secreted by various cell types in response to microbes or cytokines such as il-1 and tnf-α (38), which stimulates hepatocytes to synthesize two major acute-phase proteins: creactive protein (crp), which increases the rate of bacterial phagocytosis, and serum amyloid a (saa), which influences cell adhesion, migration, proliferation, and aggregation (39). references 1. raj m, kumar rk. obesity in children and adolescents. indian j med res 2010; 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8(4): e59498. 33. silva ta, garlet gp, fukada sy, silva js, cunha fq. chemokines in oral inflammatory diseases: apical periodontitis and periodontal disease. j dent res 2007; 86: 306-19. 34. curfs jh, meis jf, hoogkamp-korstanje ja: a primer on cytokines: sources, receptors, effects, and inducers. clin microbiol rev 1997; 10: 742-80. 35. matsushima k, ohbayashi e, takeuchi h, hosoya s, abiko y, yamazaki m. stimulation of interleukin-6 production in human dental pulp cells by peptidoglycans from lactobacillus casei. j endod 1998; 24: 252–5. 36. wisithphrom k, windsor lj. the effects of tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, and transforming growth factor-beta1 on pulp fibroblast mediated collagen degradation. j endod 2006; 32(9): 853-61. 37. horst ov, horst ja, samudrala r, dale ba. caries induced cytokine network in the odontoblast layer of human teeth. bmc immunology 2011; 12: 9 38. mostefaoui y, bart c, frenette m, rouabhia m. candida albicans and streptococcus salivarius modulate il-6, il-8, and tnf-alpha expression and secretion by engineered human oral mucosa cells. cell microbiol 2004; 6: 1085–96. 39. jones kg, brull dj, brown lc, sian m, greenhalgh rm, humphries se, powell jt. interleukin-6 (il-6) and the prognosis of abdominal aortic aneurysms. circulation 2001; 103: 2260–2265. j bagh college dentistry vol. 28(4), december 2016 comparison of the restorative dentistry 28 comparison of the marginal fitness of the ceramic crowns fabricated with different cad/cam systems (an in vitro study) akram m. abdulkareem, b.d.s. (a) adel f. ibraheem, b.d.s., m.sc. (b) abstract background: the marginal fit is the most characteristic that closely related to the longevity or success of a restoration, which is absolutely affected by the fabrication technique. the objective of present in vitro study was to evaluate the effect of four different cad/cam systems on the marginal fit of lithiµm disilicate all ceramic crowns. materials and methods: adentoform tooth of a right mandibular first molar was prepared to receive all ceramic crown restoration with deep chamfer finishing line (1mm) and axial reduction convergence angle of 6 degree, dentoform model duplicated to have nickel-chromiµm master die. thirty two stone dies produce from master die and distributed randomly in to four groups (8 dies for each group) according to the type of cad/cam system that used: group a: fabricated with ceramill motion2 (amann girrbach); group b:fabricated with cerec in lab mcxl (sirona);group c: fabricated with coritec 250i (imes-icore); group d: fabricated with zirkonzahn m5 (zirkonzahn). marginal discrepancy was measured at four points at each tooth surface. sixteen points per tooth were measured using digital stereomicroscope at (140x) magnification. results: anova and lsd post hoc tests were used to identify and localize the source of difference among the groups. it was found that there is a highly significant difference in the marginal gap mean values between group c and group d, and highly significant differences between group a and group d. conclusions: from the above result we can conclude that better marginal fit values were may be exhibited by coritec 250i cad/cam system. key words: marginal fitness, cad/cam system, ceramic crown. (j bagh coll dentistry 2016; 28(4):28-33) introduction although marginal discrepancy alone does not directly correlate with microleakage, the accuracy of marginal adaptation is valued as one of the most important parameters for the clinical quality, success, and longevity of fixed dental restorations (1). the importance of precise marginal fit and the subsequent implications of marginal misfit, including microleakage, caries, and periodontal inflammation, have been confirmed in many studies (2). generally, marginal fit proposed as clear terminology by holmes et al. through the measuring the marginal gap or the absolute marginal discrepancy (3-5). the vertical distance from the finishing line of the preparation to the cervical margin of the restoration was obvious definition of the marginal gap (6). an overall review of the data collected for the vertical marginal gap presented that 94.9% of the values measured were less than or equal to120 µm, the widest marginal gap measured was 174 µm, and the smallest was 3.7 µm (7). all-ceramic restorations are vastly used in dental field to attain the superior esthetics demanded by patients. (a) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (b) professor, department of conservative dentistry, college of dentistry, university of baghdad. they show better light transmission than other restorative material, which improved reproduction of the color and translucency of natural teeth (8). many commercially in office and laboratory cad/cam systems are available today (9,10). marginal adaptation of cad/cam restorations is relying on different parameters that include finishing line configuration, die space, type of cement used, and the cementation technique (11,12). studies were suggested that scanning, software, and milling process have a detrimental effect on the marginal adaptation of cad/cam restorations (13,14). recent studies have reported average marginal discrepancies for cad/cam restoration that range from 24-110 µm (15), and clinical studies with scanning electron microscopy data have equivalent values about 35-71µm (16). several studies have been investigated the effect of scanning and milling process of cad/cam and its related to the marginal adaptation (14,17,18). following on from these studies, it was of interest to investigate whether or not the cad/cam system used could influence the marginal accuracy of the cad/cam crowns when fabricated with lithiµm disilicate glass ceramic material. it was also of interest to evaluate whether the use of a different cad/cam system would produce a different marginal integrity of the ceramic restoration. j bagh college dentistry vol. 28(4), december 2016 comparison of the restorative dentistry 29 materials and methods preparation of master die: a dentoform tooth of a mandibular right first molar (dentoform, nissin, kyoto, japan) was prepared to receive all-ceramic crown restoration with following preparation properties: deep chamfer finish line (1mm), flat occlusal reduction to the depth of central occlusal pit, 1 to 1.5 mm of axial reduction with 6 degree convergence angle (fig.1) (19,20).the prepared dentoform tooth was used as a pattern for the construction of the metal master die (fig. 2). the dentoform tooth was sprued, invested, burn out and casting using nonprecious-dental cast alloy for ceramics on nickel base, type 3, hard. figure 1: a dentoform tooth prepared with deep chamfer finish line figure 2: master metal die fixed to acrylic base impression procedures a special tray was fabricated to be used during impression procedure. prior to fabrication of special tray, a two layer of modeling wax were adapted all around the metal die, this will provide a space about (2-2.5mm) for the impression material, the traditional method was followed to fabricate the special tray using translucent cold cure acrylic resin (21). to ensure that there is a single path of insertion and removal of the impressions, a dental surveyor was used during impression procedure. in order for the special tray to be attached on the dental surveyor, some modifications were carried out; one end of the analysis rod was fixed to the most upper part of special tray while the other end connected to the vertical suspending arm of surveyor. in addition, the lower part of the special tray that opposing the horizontal surface of the acrylic base of master die was designed so that it contained three pines to engage three holes on the acrylic base, this will serve as a guide and stopper for the special tray during impression procedure (22,23). a thin layer of tray adhesive was brushed onto the tray 24 hours after the tray fabrication. twostep impression technique was selected as technique for impression making. auto mix heavy and light viscosity polyvinylesiloxanes (pvs) (ivoclar vivadent ag, liechtenstein, italy) was used as impression materials (fig. 3). this procedure was continued thirty two times to get thirty two impression. impressions were then poured using type iv dental die stone; all the procedure was done with manufacturer's instructions. figure 3: impression making with dental surveyor. crown construction using cad/cam system thirty two stone dies were used to produce 32 crowns by using 4 different cad/cam systems. to ensure standardization the same cad programs parameters was detected for all cad/cam system, so the parameters were selected as follows: full anatomical tooth 46#; wet milling; spacer, 50µm; marginal adhesive gap, 0; starting or begin, 50µm; proximal contact, non; minimal thickness (radial), no; minimal thickness (occlusal), no; margin thickness, 0; consider instrument geometry, no; remove undercuts, yes (18). in addition, one type of lithiµm disilicate j bagh college dentistry vol. 28(4), december 2016 comparison of the restorative dentistry 30 glass ceramics material blocks, ips e.max–cad (ivoclar vivadent, schaan, liechtenstein), for cerec and inlab, lt a2, c14were used for the fabrication of the all-crowns and new set of milling burs were used for each group. ceramill motion 2 ceramill map 400 scanner and ceramillr mind software (amann girrbach gmbh, durrenweg 40, pforzheim, germany) were used for scanning and designing of the group a restorations. data were sent to the ceramill motion 2 milling engine, 5-axis milling device, wet grinding, three steps milling with diamond burs: 2.5mm, 1.0mm and 0.6mm (fig :4). figure 4: final crown design before milling cerec in lab mcxl ineos blue scanner and in lab 4.2 software (sirona dental systems gmbh, bensheim, germany) were used for scanning and designing of the group b restorations. cerec in lab mcxl milling engine, 4-axis milling device, wetgrinding, two step milling with diamond burs: step bur 12s (1.2 mm) and step bur 12 (1.0 mm) has been used to produce eight glass ceramic crowns by milling the ips emax cad blocks. coritec 250i i3d scan scanner and the exocad software were used for the scanning and designing of the group c restoration, which was milled with coritec 250i milling engine (imes-icore gmbh, leibozgraben, germany) , 5-axis milling device, wet grinding, three steps milling with diamond grinding pins: 2.5/6.0 mm, 1.0/6.0 mm and 0.6/6.0 mm. zirkonzahn m5 s600 arti scanner and zirkonzahn software package were used for the scanning and designing of the group d restoration. ips emax cad block has been milled with m5 milling engine (zirkonzahn gmbh, italy), 5+1 axis milling device, wet grinding, three steps milling with diamond burs: 2.5 mm for rough milling, 1.0 mm for precise milling and 0.6 mm for very precise milling. this procedure was repeated for each die stone with his group following the manufacturer's instructions. after the completion of the glass ceramic crowns construction for all groups, all crowns were glazed and fired using ips e-max cad crystal/glaze (ivoclar vivadent, italy) and fired with digital porcelain furnace (programat ep3000), (ivoclar vivadent ag, schaan, liechtenstein), ips emax glazing program. measurement of the marginal gap the marginal fit of the crown was calculated by measuring the vertical gap between the margin of the master die and that of the ceramic crown, all crowns were seated on master die to ensure standardization of study. four indentations on the margin at the midpoint of mesial, distal, buccal and palatal surfaces of the master die were done. four points in each surface were selected for vertical marginal gap measurement by using a stereo-microscope (17,22,24). a screw loaded holding device (essentials, china) was used during all measurement steps in order to maintain a seating pressure of(50 n) between all-ceramic crown and the master die (19, 25-27).to apply a uniform static load on the tested crown, a loading cell sensor (sf-400, china) was fixed to the metal die base during measurement procedure. the measurement were performed on four points on each surface (two on each side of the indentation), first point was determined on the edge of the indentation whereas the second one was (1mm) away from the first point (28). this was achieved by using a stereo microscope with a digital camera in the eye lens connected with the computer. the digital images were captured and measurements were done using image j software (image j 1.32, u.s. nih, bethesda, ma, usa) which calculated the values in pixels, mark by drawing a line between the finishing line on the die and the crown margin line (29) (fig. 5). figure 5: two points for marginal gap measurement with image j j bagh college dentistry vol. 28(4), december 2016 comparison of the restorative dentistry 31 the images were observed and captured at 140x magnification and calibrated using a photograph of a (1mm) increment taken at the same focal length and input into (image j) by the option of set scale, which converted all the calculated reading from pixels to (µm) (24). sixteen measurements were obtained from all the four surfaces (mesial, distal, palatal and buccal) of each sample. all measurements were done by the same investigator (17,28). statistical analyses data were collected and analyzed using spss (statistical package of social science) software version 15 for windows 8.1 chicago, usa. the following statistics were used: adescriptive statistic: including mean, standard deviation, statistical tables and graphical presentation by bar charts. binferential statistics 1one way analysis of variance test (anova) was used to see if there were any significant differences among the means of groups. 2-lsd (least significant difference) test was carried out to examine the source of differences among the four groups. results total of (512) measurements of vertical marginal gap from four groups were recorded, with 16 measurements for each crown. table (1) showed that the highest mean of vertical marginal gap was recorded in group d (39.12 µm ± 3.969) (manufactured with zirkonzhan cad/cam system).while the lowest mean marginal gap was recorded in group c (29.00 µm ±4.761) (manufactured with imesicore cad/cam system). table (2) showed that there is a highly significant difference in vertical marginal gap among the four groups. table 1: descriptive statistics of vertical marginal gap for the four groups in (µm) source of variation n mean s.d. min max group a amann girrbach system 8 29.3984 ±5.569 21.63 37.75 group b sirona system 8 33.6484 ±5.409 28.88 43.63 group c imes-icore 8 29.0000 ±4.761 22.63 35.94 group d zirkonzhan system 8 39.1250 ±3.969 34.25 46.00 total 32 32.7930 6.28571 21.63 46.00 table 2: one way-anova test among the four groups significant at p≤ 0.05 discussion results obtained from the current study showed that the marginal gap of the 4 tested groups was within the clinically acceptable range and with acceptable range of the cad/cam fabricated restoration marginal gap, because the mean marginal gap with the range of 100 μm have been proposed as being clinically acceptable with regard to the longevity of restorations(30). furthermore, recent studies have reported that vertical marginal gap for cad/cam fabricated all ceramic restorations range from 24 to 110 µm (6,15,27). this study revealed different values of vertical marginal gap among the four groups, which indicated that the type of the cad/cam system may affected the marginal adaptation of the all ceramic crown fabricated with cad/cam technology, these results were in agreement with other study reported the same result (14,17,18,31,32). in present study there is a highly significant difference was reported between group d (zirkonzhan m5) with group a (ceramill motion 2) and c (coritech 250i) respectively, in addition to the significant differences between group d and group b (cerec in lab mcxl), the explanation that the various result for different cad/cam systems has been resulted during different steps in cad/cam processing, scanning, design and milling step. the first three systems (ceramill motion 2, cerec in lab mcxl, coritec 250i) used the blue-light scanning technology, which use short wavelength that lead to high level of scanning accuracy as compared to the s600 arti scanner of zirkonzhan system which used the red laser anova sµm of squares d.f. mean square f-test sig. between groups 533.887 3 177.962 7.212 .001 (hs) within groups 690.929 28 24.676 total 1224.816 31 j bagh college dentistry vol. 28(4), december 2016 comparison of the restorative dentistry 32 technology to capture image from multiple angles for scanning, but with the higher wavelength of red laser, the accuracy of scanner may reduce, this findings were in agreement with that reported by neves et al. (33). but disagree with another opinion that the variability of cutting tool was another explanation of these differences. an additional to the problem that may associate with scanning device during ceramic restorations constructed with cad/cam, the design of the cutting tools may affect the marginal accuracy of all ceramic restoration because it may be larger in diameter than some small parts of the tooth preparation, such as the inner surface of the finish line causing misfits, resulting in inferior marginal adaptation, this will coincided with that reported by reich et al. (34). in current study, cerec in lab mcxl system (group b) may provide less marginal fit as compared with group a and group c, these differences may attributed to that cerec in lab mcxl system was used a 4-axis milling device, while the coritec 250i and ceramill motion 2 systems were used a 5-axis milling machine. the five-axis milling machine have been found to improve accuracy and precision of the ceramic restorations by using the machines additional axes; these 2 additional orientation axes allow the machining and processing of complex parts, which cannot be machined with 3-axis and 4-axis orientation machines. the 5-axis machinery has superior cutting conditions to those of the 3-axis type or 4-axis type, which improves the efficiency of the milling by creating efficient tool paths and movement directions which improve the dimensional accuracy, texture, and surface finish of the milled products. this may explain the more accurate fit of restoration that fabricated with 5axis milling machine (13,35).these findings were coincided with different studies reported that the 5-axis milling device of cad/cam system provided better marginal adaptation than 4-axis milling device (14,17,18). however conflicted with another opinion that the quality or marginal accuracy of the ceramic restoration does not necessarily improve as the number of milling device axes increases, which reported with a study that done by beuer et al. (36). in this study, the result was revealed that the coritec 250i (group c) may demonstrated smaller marginal gaps than the ceramill motion 2 (group a) group. in spite of that the both cad/cam systems are similar to each other in fabricating steps of lithium disilicate restorations and the milling device movement axes, there is apriority for the coritec system in the result obtained with each systems. these priority may attributed to the efficiency of cad software and the constant quality of scanners, which may make the restoration fabricated with the coritec 250i system more precise in marginal fit. these results were in agreement with that reported by agarwal and ram (37) that the type of the cad/cam scanner have been affected the marginal adaptation of the ceramic restoration. also, software limitations in restorations design, could produce errors in the cad/cam technique especially during manual tracing of the finish line, this fact was coincided with other studies (38,39), but disagree with another studies that reported, the shape of the cutting instrument is various and these differences may affect the final result of ceramic restoration (18,33). for example, significant enlargement in internal gap would result when the internal cutting bur that used in milling device larger than small parts of the tooth preparation considering manufacturing techniques and tools, this will agree and parallel with that reported by abduo et al. (40). it can be concluded that better marginal fit values were exhibited by coritec 250i cad/cam system. the present study was supported the good performance of cad/cam milling process of singleunite lithiµme disilicate fdp while also highlighting the possible effect of different cad/cam scanner and software on fdp fabrication. references 1. white sn, ingles s, kipnis v. influence of marginal opening on microleakage of cemented artificial crowns. j prosthet dent 1994; 71(3): 257-64. 2. beuer f, naµmann m, gernet w, sorensen ja. precision of fit: zirconia three-unit fixed dental prostheses. clin oral investig 2009; 13: 343-49. 3. holmes jr, bayne sc, holland ga, sulik wd. considerations in measurement of marginal fit. j prosthet dent 1989; 62: 405-8. 4. suarez mj, gonzalez de villaµmbrosia p, pradies g, lozano jf. comparison of the marginal fit of procera allceram crowns with two finish lines. int j prosthodont 2003; 16: 229-32. 5. pelekanos s, koµmanou m, koutayas so, zinelis s, eliades g. micro-ct evaluation of the marginal fit of different in-ceram alµmina copings. eur j esthet dent 2009; 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31: 2559-73. 36. beuer f, schweiger j, edelhoff d. digital dentistry: an overview of recent developments for cad/cam generated restorations. br dent j 2008; 204(9): 50511. 37. agarwal n, ram s. a comparative evaluation of marginal fit of crowns fabricated by three all ceramic cad/cam systems using their respective scanners an in vitro study. j contemporary dent 2012; 2(1): 10-9. 38. aboushelib mn, elmahy wa, ghazy mh. internal adaptation, marginal accuracy and microleakage of a pressable versus a machinable ceramic laminate veneers. j dent 2012; 40: 670-7. 39. kollmuss m, kist s, goeke je, hickel r, huth kc. comparison of chairside and laboratory cad/cam to conventional produced all-ceramic crowns regarding morphology, occlusion, and aesthetics. (internet), springer berlin heidelberg, 07 aug 2015, available from: www.springer/link/com . 40. abduo j, lyons k, swain m. fit of zirconia fixed partial denture: a systematic review. j oral rehabil 2010; 37: 866–76. http://www.ncbi.nlm.nih.gov/pubmed/?term=song%20tj%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=kwon%20tk%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=yang%20jh%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=han%20js%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=lee%20jb%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=kim%20sh%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=yeo%20is%5bauth%5d http://www.springer/link/com shahbaa f.doc j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry151 soft tissue facial profile analysis of adult iraqis with different classes of malocclusion shahbaa a. mohammed, b.d.s., m.sc. (1) layth m. k. nissan, b.d.s., m.sc. (1) shaymaa sh. taha, b.d.s., m.sc. (1) abstract background: complete analysis of facial profile should also include an evaluation of soft tissue morphology. materials and method:the sample consisted of 90 iraqi adults (45 males and 45 females) aged 18-25 years from baghdad city divided into 3 groups according to the anb angle with 30 subjects in each group (15 males and 15 females) for class i, ii and iii. lateral cephalometric radiograph was taken for each subject and 8 angular and 5 linear measurements were identified and determined, t-test, anova and lsd test were used to compare between both genders and between different classes. results:showed that females had greater angular measurements and smaller linear measurements with more lip prominence than males in all classes, there was more convex facial profile with more prominent forehead, more prominent tip of the nose with increased facial heights and more prominent lips in class ii subjects than in class i and iiisubjects. conclusion: there is wide variation in soft tissue facial profile among different classes of malocclusion and careful determination of the components of soft tissue facial profile is very important in the diagnosis and treatment planning. key wards: soft tissue facial profile, malocclusion classes, profile analysis. (j bagh coll dentistry 2013; 25(4):151-159). introduction one of the primary goals of orthodontic treatment is to preserve and/or achieve optimal facial esthetics and balanced facial profile for any form of malocclusion.the harmonious soft tissue profile is one of the most important treatment goals in orthodontics and soft tissue profile analysis can provide valuable information in developing a meaningful concept of facial esthetic and harmony and supplemental tool for diagnosis and treatment planning1. facial harmony is defined as orderly and pleasing arrangement of the facial parts in profile.facial harmony in orthodontics is determined by the morphological relationships and proportions of the parts of the face that include the facial profile as a whole; the nose, the lips and the chin2, 3.the soft tissue covering the face plays an important role in facial esthetics, speech and other physiological functions, moreover the force generated by the perioral soft tissue structure is known to be the most potent that can affect tooth position and malocclusion, therefore a good evaluation of soft tissue profile is very important in the standard diagnosis and treatment planningto ensure post treatment stabilityand success 4. successful evaluation of the facial balance and harmony include a study of the facial profile and the relationship of the nose, lips and chin; and after the clinical introduction of x-ray cephalometrics; lateral cephalometric radiograph has been used to study and evaluate the soft tissue (1)lecturer. department of orthodontics. college of dentistry. university of baghdad. profile including studies of the alteration that may occur as result of growth or effect of orthodontic treatment on the soft tissue profile 5, studies to predict and measure the changes associated with orthognathic surgery 6, studies dealing with facial forms to establish a base line data 7, 8 and studies that compare between the soft tissue profile of two or more populations or different ethnic groups 9, 10. relying on dentoskeletal analysis for treatment planning can sometimes lead to esthetic problems, especially when the orthodontist tries to predict soft tissue outcome using only hard tissue normal values. many authors obtained soft tissue standards from subjects selected on basis of class i normal occlusion due to presence of strong interrelation between good facial esthetics and good occlusion 11. however, good occlusion does not necessarily mean good facial balance 1. the soft tissue analysis includes an appraisal of the adaptation of soft tissue to the bony profile with consideration to the size, shape and the posture of the parts of the face as seen on the lateral head film 2, 3. it has been shown previously that a marked variation exists in the soft tissue covering the skeletodental framework, and the soft tissue vary in thickness over different parts of the facial skeleton, therefore the outline of the soft tissue profile does not correspond well with the underlying skeletal framework so that complete analysis of facial profile should also include an evaluation of soft tissue morphology 12. as mentioned earlier most authors obtained soft tissue profile standards from subjects withclass i normal occlusion, therefore the present j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 152 study was carried out to study and compare between the soft tissue profile analysis in iraqi subjects with class i, ii and iii occlusion. materials and methods sample out of more than 200 subjects attending the orthodontic department at the college of dentistry, university of baghdad; 90 subjects were selected that fit the following selection criteria: 1. all the subjects were iraqi arabs and were 1825 years old. 2. they have complete set of permanent teeth regardless of the third molar with no severe crowding or spacing and no bimaxillary protrusion. 3. they have no facial asymmetry or malformation and no previous orthodontic or orthopedic treatment. the subjects were divided into three groups as follows13: 1. class i group (30 subjects; 15 males and 15 females) with class i molar relation and normal overjet and overbite (2-4 mm) and normal anb angle (2-4º). 2. class ii group (30 subjects; 15 males and 15 females) with class ii molar relation with increased overbite greater than 4 mm and anb angle greater than 4º. 3. class iii group (30 subjects; 15 males and 15 females) with class iii molar relation with overjet less than 2 mm and anb less than 2º. method after clinical examination a lateral cephalometric radiograph was taken for each subject with p m 2002 prolineplanmeca x-ray machine, all the images were imported into pentium 4 laptop for processing where all the measurements were done using autocad software and cephalometric points and planes were determined and then angular and linear measurements were obtained (after correction of the magnification). cephalometric points13, 14 (figure 1) skeletal points • nasion (n): the most anterior point of frontonasal suture. • orbitale (or): the lowest point of orbital shadow. • porion (po): the most superior point of the external auditory meatus. • pogonion (pog): the most anterior point of the bony chin. • subspinale (point a): deepest midline point in the curved bony outline from the base to the alveolar process of the maxilla. • menton (me): the most caudal point in the outline of the symphysis. • gonion (go): at the intersection of the lines tangent to the posterior border of the ramus and the mandibular base. soft tissue points • skin nasion (n): the most concave point overlying the area of frontonasal suture. • pronasal (no): tip of the nose which is the most anterior point in the midsagittal plane. • subnasale (sn): where the nasal septum merges with the upper cutaneous lip in the midsagittal plane. • labralesuperius (ls): the most anterior point on the margin of the upper membranous lip. • stomion (sto): the median point of oral embrasure when the lips are closed. • labraleinferius (li): the most anterior point on the margin of the lower membranous lip. • soft tissue submentale (sm): the point of greatest concavity in the midline of lower lip. • soft tissue pogonion (pog): the most prominent point on soft tissue midsagittal plane. planes: (figure 1) • skeletal facial plane (n pog): line extending from nasion to pogonion. • frankfort horizontal plane (fh): horizontal plane running between porion and orbitale. • mandibular plane (mp): line tangent to the lower border of the mandible angular measurement: (figure 2) • angle of convexity (n-a-pog): it expresses the protrusion of the maxillary part of the face to the total profile13. • skeletal facial mandibular angle (sk-mp): the angle between the skeletal facial plane and mandibular plane, it was developed by 15. • nasofrontal angle: formed by a line tangent to the forehead from soft tissue nasion with the line tangent to the dorsum of the nose. • nasal angle: formed by a line tangent to the dorsum of the nose from soft tissue nasion with the line tangent to the lower border of the nose from soft tissue subnasale. • nasolabial angle: formed by a line tangent to the lower border of the nose from soft tissue subnasale with the line from labralesuperius to subnasale. j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 153 • interlabial angle: it is the intersection angle at stomion of lines extending from labralesuperius and labraleinferius. • labiomental angle: it is the intersection angle at point (sm) of lines extending from labraleinferius and the tangent to the chin 16. • z-angle: formed by a line tangential to the soft tissue chin and to the most anterior part of either upper or lower lip which ever was most prominent to intersect the frankfort horizontal plane 17. linear measurements: (figure 1) a-vertical: all the vertical variables were measured (in millimeters) perpendicular to the frankfort horizontal plane; the following measurements were done 13: • upper facial height (ufh): distance between soft tissue nasion to subnasale point. • lower facial height (lfh): distance between subnasale point and soft tissue pogonion. • total facial height (tfh): distance between soft tissue nasion to soft tissue pogonion bhorizontal: the perpendicular measurements on ricketts esthetic line ("e" line) from ls and li 2. statistical analysis: was done using spss software version 15. 1. descriptive statistics: means and standard deviations 2. inferential statistics: independent sample t-test to compare between means for gender differences, anova test followed by lsd test was used to compare between the means of the three groups. the following levels of significance were used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 * significant 0.01 ≥ p > 0.001 ** highly significant p ≤ 0.001 *** very highly significant results and discussion the descriptive statistics and gender differences between males and females for all the variables in class i, ii and iii are shown in table (1). comparison between different classes in the study was done using anova test followed by lsd test for the measurements that showed significant difference and the results are shown in table (2) for males and in table (3) for females. figure 1: cephalometric points, planes and linear measurements. po or n go po g n me po g li ls sn no sm a sto ricke tts ”e” line n po g mp t f ufh lfh fh z-angle nasal nasofrontal sk-mp n-a-pog nasolabial interlabial labiomental figure 2: angular measurements used. j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 154 study of the soft tissue covering of the face plays an important role in facial esthetics and these soft tissues are affected by a variety of variables including skeletal relationship, soft tissue thickness and function 18. many studies for profile analysis were done in iraq, however all their samples were having class i normal occlusion 19, 20 or comparison between class i and ii 21, in this study a comparison was done among the soft tissue facial profile for class i, ii and class iii occlusion in a sample of iraqi adults, therefore comparing the results with other studies may be difficult due to difference of the sample or difference in the variables measured. the results for the variables in this study showed the following: • n-a-pog angle; there was non-significant difference between both genders for all the classes, however the mean values were higher in males than in females in class i sample which could be due to that males have more straight profiles than females 3, 13, 20-22, while it was higher in females in class ii and iii (table 1). when comparing among different classes we found higher values in class iii and lowest in class ii sample with significant difference for males (table 2) and females (table 3) and this could be due to the difference in the position of the skeletal bases in the sagittal plane with the maxilla in more anterior position than the mandible in class ii sample than in class i and iii 13. • sk-mp angle was higher in females than in males in class i subjects and this differ from other studies 19, 20, while it was higher in males than females with significant difference in class ii and iii subjects indicating that females have more facial tapering than males in these groups (table 1). however there was significant difference among different classes for males and females with more facial tapering in class iii males (table 2) and females (table 3) followed by other classes. this angle is greatly affected by the direction of mandibular rotation and further studies may be required to investigate the relation in different skeletal classes. • nasofrontal angle was higher in females than in males with significant difference for all the classes (table 1), while it was higher in class iii subjects and lowest in class ii subjects for males (table 2) and females (table 3) with significant differences and these results are similar to those of 19, 21. these results indicate that class iii subjects have slightly more flattened forehead than that of class i and ii subjects. this angle is highly related to the length of anterior cranial base and direction of facial growth and as the class ii subjects have more anteriorly positioned maxillary base than the mandible so this may bring the nose into more prominent position in the face increasing the value of this angle, and this agree with 23. • nasal angle was higher in females than in males with significant difference for all the classes (table 1), which means that females have more rounded tip of the nose than males and this could be due to the fact that males have more growth increment than females 21, 24, however the nasal angle was higher in class iii subjects and lowest in class ii subjects with significant difference for males (table 2) and non-significant difference for females (table 3) which means that class iii subjects have more rounded and less prominent tip of the nose than other classes in the study while class ii subjects have more prominent tip of the nose which give the face more convex appearance and this could be due to the more anterior position of the nasomaxillary complex in class ii subjects while in class iii subjects the more prominent mandible and chin and/or retruded maxilla make the face appear more flattened and concave 25. • nasolabial angle was higher in females than in maleswith significant difference for all the classes (table 1), however there was higher values in class ii males than class i and class iii males with significant difference (table 2), and higher in class i females than class ii and class iii females (table 3). this angle is affected by the elevation of the nose tip and also the inclination of the upper incisors which could lead to difference in the values of the angle unrelated to the underlying skeletal pattern 18, our results differ from 21 who found no difference between class i and ii sample. • interlabial angle was higher in females than in males in class i and class ii subjects and higher in males in class iii sample (table 1), and these results are somewhat similar to the findings of other studies 19-21. however it was higher in class iii males than in class ii and i maleswith significant difference (table 2), and higher in class i females than class ii and iii with significant difference (table 3). the value of this angle is greatly affected by the position and inclination of the incisor teeth (upper or lower) and/or the thickness of the lips 26 and further studies may be needed to study that effect. • labiomental angle was higher in females than males for all the classes with significant difference (table 1). however it was higher in j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 155 class iii subjects and lowest in class ii subjects for males and females with significant difference (table 2, 3), this could be caused by that the more anterior position of the mandible in class iii subjects may cause flattening to the mentolabial sulcus while in class ii subjects the more posterior position of the mandible may cause deepening of the mentolabial sulcus due to curling of the lower lip into forward position to contact the upper lip causing more acute angle 27. our results were higher than that of 19-22, 28 and similar to 8. • z-angle was higher in females than in males for all the classes although it was nonsignificant (table 1). however it was higher in class iii male sample and lowest in class ii with significant difference (table 2), while it was higher in class i females and lowest in class ii (table 3), this could be due to the fact that this angle is affected by the position of the lips and the chin in anterioposterior relation and as the mandible is in more anterior position in class iii so the angle becomes more obtuse, while in class ii relation the mandible is in more posterior pisition and the angle becomes more acute 17.our results were higher than that of 21 and similar to 20, 22 and lower than 17. • facial heights; the values were lower in females than in males with significant difference for all the classes(table 1) and this is similar to other findings 3, 19-21, 29 and this could be because males have larger growth increment that continues for longer period than females, however when we compared between different classes we found that for both genders the values were higher in class ii subjects than those of other classes (table 2, 3); this could be as a result of the direction of growth of the nasomaxillary complex in class ii sample could have some excess of growth in a forward and/or downward direction causing increase in the facial heights more than that of other classes 24. • e-ls and e-li;our results showed that females have more protrusion of the upper and lower lips in relation to the nose and chin than males in all the classes except upper lip in class i and lower lip in class iii subjects, however there was non-significant difference for most of the readings (table 1), this could be because males have larger measurements than females in general or males have longer lasting mandibular growth that could continue into adult life which may bring chin forward in relation to the nose 20, 24, 29, 30. however there was more protrusion of the upper lip in class ii males and females than that of class i and class iii subjects with significant difference, and more retrusion of the upper lip in class iii subjects than in other classes (table 2, 3), while for the lower lip there was more protrusion in class ii females than other classeswith significant difference, while for males the lower lip was more protruded in class iii subjects than in class i and class ii subjects, this could be due to the effect of the difference in the position of the tip of the nose and position of the chin in different classes and also the effect of the degree of the inclination of the incisors on lip protrusion which is greatly affected by the skeletal relation of the underlying dental bases resulting in different degrees of lip protrusion or retrusion in the upper or lower arch 13. in summary we can say that: • females have higher values of almost all the angular measurements than males and this would give the face a smoother outline with more pleasant appearance than males. • facial heights were higher in males than in females in all the classes with higher values in class ii sample than other classes. • females have more prominent upper and lower lips in almost all the classes than males especially in class ii sample. • females have less prominent tip of the nose than males in all classes while males have more prominent tip of the nose in class ii subjects than other classes. • males and females have similar skeletal facial profile in all classes of the study with more convex facial profile in class ii subjects than class iii and class i that showed straight facial profile. • class ii subjects showed more prominent forehead than other classes. • there is more facial tapering in males than in females in class ii and class iii subjects. • the lips are more prominent than the chin in class ii subjects than those of class i and iii subjects. j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 156 references 1. bergman rt. cephalometric soft tissue facial analysis. am j orthod dentofac orthop 1999; 116: 373-89. 2. ricketts rm. esthetic environment and the law of lip relation. am j orthod 1967; 54(4): 272-89. 3. skinazi gl, lindauer sj, isacson rj. chin, nose, and lips normal ratios in young men and women. am j orthod 1994; 106(4): 510-23. 4. jung mh, yang ws, nahm ds. effects of upper lip closing force on craniofacial structures. am j orthod dentofac orthop 2003; 123: 58-63. 5. bishara se, zaher ab, cumins dm, jackobson. effect of orthodontic treatment on the growth of individuals with class ii division 1malocclusion. angle orthod 1994; 64(3): 221-30.(ivsl) 6. kobayashi-t, ueda-k, honma-k, sasakur-h, hauadak, nakajim-t. three dimensional analysis of facial morphology before and after orthodontic surgery. j craniomaxillofac surg 1990; 18(2): 68-73. 7. lundstrom t, forsbery gm, peck s, mcwillaim j. a proportional analysis of the soft tissue facial profile on young adults with normal occlusion. angle orthod1992; 62(2): 127-133.(ivsl) 8. sandra a-m, marina l-v, mladen š. analysis of the soft tissue facial profile by means of angularmeasurements. eur j orthod 2008; 30: 135–40. 9. celebi aa, tan e, gelgor ie, colak t, ayyildiz e. comparison of soft tissue cephalometric norms between turkish and european-american adults. the scientific world j 2013; 1-6. 10. hashim ha, al-barakati sf. cephalometric soft tissue profile analysis between two different ethnic groups: a comparative study. j contemp dent practice 2003; 4(2): 60-73. 11. forsberg cm, derrick l. changes in the relationship between the lips and the aesthetic line from 7 years of age to adulthood. eur j orthod 1979; 1: 265-70. 12. holdaway ra. asoft-tissue cephalometric analysis and its use in orthodontic treatment planning, part ii. am j orthod 1984; 85: 279-93. 13. rakosi t. an atlas and manual of cephalometric radiography. 2nd ed. london: wolfe medical publications ltd; 1982. 14. jacobson a, caufield p. introduction to radiographic cephalometry. 1st ed. pheladelphia; lea and febiger; 1985. 15. rickettsrm. a foundation for cephalometric communication. am j orthod 1957; 46: 330-7. 16. smith rj, drobocky ob. changes in facial profile during orthodontic treatment with extraction of four first premolars. am j ortho 1989; 95(3): 220-30. 17. merrifield ll. the profile line as an aid in critically evaluating facial esthetics. am j orthod1966; 52: 80422. 18. saxby phj, freer uj. dentoskeletal determinants of soft tissue morphology. angle orthod 1985; 55(2): 147-54.(ivsl) 19. al-ta'ani, ma. soft tissue facial profile analysis, cephalometric study of iraqi adults. a master thesis, college of dentistry, baghdad university, 1996. 20. agha nf. facial profile soft tissue analysis for mosuli adults class i normal occlusion. a master thesis, college of dentistry, mosul university, 1998. 21. youssef ma. soft tissue facial profile analysis: a comparative studyof the dental and skeletal class i and class ii for iraqi adult sample. a master thesis, college of dentistry, baghdad university, 2001. 22. al-zubaidi sh. the skeletal and soft tissue facial profile in adolescent and adult. al-rafidain dent j 2009; 9(1):149-55. 23. obwegeser hl. profile planning based on alteration in the position of the bases of the facial thirds. j oral maxillofac surg 1986; 44(10): 302-12. 24. chaconas sj, bartroff jd. prediction of normal soft tissue facial changes. angle orthod 1975; 45(1): 1225. (ivsl) 25. rothstein tl. facial morphology and growth from 10 to 14 years of age in children presenting class ii division 1 malocclusion: a comparative roentgenographic cephalometric study. am j orthod 1971; 60:619-20. 26. sayagh nm. correlational study of the facial soft tissue dimensions to the underlying dentoskeletal structures. iraqi dent j 2002; 30: 5-28. 27. pancherz h, zieber k, hoger b. cephalometric characteristics of class ii division l and class ii division 2 malocclusion: a comparative study. angle orthod 1997; 2: 11-120.(ivsl) 28. al-ani ra. soft tissue profile analysis for iraqi patients with β-thalassemia major. must dent j 2008; 5(2):187-93. 29. ghaib nh, al-timimy i. soft tissue facial profile analysis. iraqi dent j 2003; 33: 91-113. 30. hameed a, khan ji, ijaz a. soft tissue facial profile analysis in patients with class i and class ii skeletal pattern visiting children’s hospital, lahore. pakistan oral dental j 2008; 28(2): 183-8. j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 157 table 1: descriptive statistics and gender differences for class i, ii and iii variables class descriptive statistics genders difference males (n=15) females (n=15) (d.f.=28) mean s.d. mean s.d. t-test p-value n-a-pog cl i 175.13 1.68 175.07 1.98 0.1 0.922 (ns) cl ii 167.73 2.15 168.8 1.82 -1.46 0.154 (ns) cl iii 175.13 1.85 176.2 2.01 -1.51 0.141(ns) sk-mp cl i 66.73 1.75 67.73 1.71 -1.58 0.125 (ns) cl ii 68.67 1.91 63.53 1.81 7.55 0.000 ** cl iii 64.93 2.02 61.87 1.92 4.26 0.000 ** nasofrontal cl i 124.4 1.96 128 1.89 -5.13 0.000 ** cl ii 120.73 1.94 126.2 1.57 -8.48 0.000 ** cl iii 127.4 2.06 128.67 1.95 -1.73 0.095 (ns) nasal cl i 75.2 1.7 81 2.1 -8.31 0.000 ** cl ii 70.87 1.85 80 1.85 -13.53 0.000 ** cl iii 77.67 1.95 81.53 2.17 -5.14 0.000 ** nasolabial cl i 102.6 2.16 112.4 1.99 -12.9 0.000 ** cl ii 105.07 1.58 110.6 1.8 -8.94 0.000 ** cl iii 98.27 1.94 100.6 2.03 -3.22 0.003 ** interlabial cl i 98.27 2.25 110.87 1.81 -16.9 0.000 ** cl ii 109.33 1.72 110.47 1.88 -1.72 0.096 (ns) cl iii 110.07 1.83 103.8 1.97 9.02 0.000 ** labiomental cl i 129.4 1.8 131.8 2.04 -3.41 0.002 ** cl ii 101 1.69 129.8 1.93 -43.42 0.000 ** cl iii 131.53 1.88 139 2 -10.52 0.000 ** z angle cl i 76.8 1.97 79.53 1.68 -4.08 0.000 ** cl ii 69.6 1.35 69.87 1.77 -0.46 0.646 (ns) cl iii 79 1.56 79.07 1.79 -0.11 0.914 (ns) ufh cl i 56.39 1.92 55.89 1.97 0.7 0.488 (ns) cl ii 58.87 1.86 56.1 1.77 4.17 0.000 ** cl iii 56.68 1.78 55.3 1.8 2.11 0.044 * lfh cl i 55.94 1.99 48.95 1.9 9.84 0.000 ** cl ii 60.87 1.99 56.57 1.77 6.24 0.000 ** cl iii 54.85 1.99 52.84 1.85 2.85 0.008 ** tfh cl i 110.88 1.47 103.09 1.71 13.37 0.000 ** cl ii 120.03 1.48 111.04 1.82 14.86 0.000 ** cl iii 111.22 2.14 106.05 1.64 7.44 0.000 ** e line-ls cl i 4.28 1.59 5.01 1.1 -1.47 0.152 (ns) cl ii 3.45 2.12 2.19 1.76 1.78 0.086 (ns) cl iii 5.21 1.9 5.04 1.22 0.3 0.763 (ns) e line-li cl i 2.88 1.65 2 1.94 1.34 0.192 (ns) cl ii 1.26 1.87 -0.06 1.09 2.35 0.026 * cl iii 0.49 2.09 0.63 1.27 -0.23 0.818 (ns) s.d.: standard deviation, d.f.: degree of freedom j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 158 table 2: comparison between the measurements of class i, ii and iii for males using anova test followed by lsd test variables anova for males class i (n=15), class ii (n=15), class iii (n=15) classes difference (d.f.=44) lsd test after anova for males classes mean p-value f-test p-value difference n-a-pog 75.46 0.000 ** i ii 7.4 0.000 ** iii 0 1 (ns) ii iii -7.4 0.000 ** sk-mp 14.52 0.000 ** i ii -1.93 0.008 ** iii 1.8 0.013 * ii iii 3.73 0.000 ** nasofrontal 42.28 0.000 ** i ii 3.67 0.000 ** iii -3 0.000 ** ii iii -6.67 0.000 ** nasal 52.77 0.000 ** i ii 4.33 0.000 ** iii -2.47 0.001 ** ii iii -6.8 0.000 ** nasolabial 48.65 0.000 ** i ii -2.47 0.001 ** iii 4.33 0.000 ** ii iii 6.8 0.000 ** interlabial 172.97 0.000 ** i ii -11.07 0.000 ** iii -11.8 0.000 ** ii iii -0.73 0.308 (ns) labiomental 1352.63 0.000 ** i ii 28.4 0.000 ** iii -2.13 0.002 ** ii iii -30.53 0.000 ** z angle 133.59 0.000 ** i ii 7.2 0.000 ** iii -2.2 0.001 ** ii iii -9.4 0.000 ** ufh 8.03 0.001 ** i ii -2.48 0.001 ** iii -0.29 0.671 (ns) ii iii 2.19 0.002 ** lfh 38.99 0.000 ** i ii -4.93 0.000 ** iii 1.09 0.139 (ns) ii iii 6.02 0.000 ** tfh 136.2 0.000 ** i ii -9.15 0.000 ** iii -0.34 0.587 (ns) ii iii 8.81 0.000 ** e line-ls 3.29 0.047 * i ii 0.82 0.237 (ns) iii -0.94 0.180 (ns) ii iii -1.76 0.014 * e line-li 6.38 0.004 ** i ii 1.63 0.022 * iii 2.4 0.001 ** ii iii 0.77 0.268 (ns) n: number,d.f.: degree of freedom j bagh college dentistry vol. 25(4), december 2013 soft tissue facial profile pedodontics, orthodontics and preventive dentistry 159 table 3: comparison between the measurements of class i, ii and iii for females using anova test followed by lsd test. variables anova for females class i (n=15), class ii (n=15), class iii (n=15) classes difference (d.f.=44) lsd test after anova for females classes mean p-value f-test p-value difference n-a-pog 63.45 0.000 ** i ii 6.27 0.000 ** iii -1.13 0.117 (ns) ii iii -7.4 0.000 ** sk-mp 41.6 0.000 ** i ii 4.2 0.000 ** iii 5.87 0.000 ** ii iii 1.67 0.016 * nasofrontal 7.45 0.002 ** i ii 1.8 0.009 ** iii -0.67 0.319 (ns) ii iii -2.47 0.001 ** nasal 2.17 0.127 (ns) i ii ns ns iii ns ns ii iii ns ns nasolabial 160.33 0.000 ** i ii 1.8 0.015 * iii 11.8 0.000 ** ii iii 10 0.000 ** interlabial 66.24 0.000 ** i ii 0.4 0.565 (ns) iii 7.07 0.000 ** ii iii 6.67 0.000 ** labiomental 88.43 0.000 ** i ii 2 0.009 * iii -7.2 0.000 ** ii iii -9.2 0.000 ** z angle 145.81 0.000 ** i ii 9.67 0.000 ** iii -9.67 0.000 ** ii iii -9.2 0.000 ** ufh 0.76 0.476 (ns) i ii ns ns iii ns ns ii iii ns ns lfh 64.02 0.000 ** i ii -7.62 0.000 ** iii -3.9 0.000 ** ii iii 3.72 0.000 ** tfh 81.14 0.000 ** i ii -7.94 0.000 ** iii -2.96 0.000 ** ii iii 4.98 0.000 ** e line-ls 20.88 0.000 ** i ii 2.82 0.000 ** iii -0.02 0.961 (ns) ii iii -2.85 0.000 ** e line-li 7.52 0.002 ** i ii 2.06 0.000 ** iii 1.37 0.015 * ii iii -0.69 0.208 (ns) n: number, d.f.: degree of freedom type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 1 research article salivary vitamin d3 in relation to dental caries among pregnant women in baghdad city maimonah tariq abed1*, nada jafer mh radhi2 1 master student, ministry of health, baghdad. 2 assist professor. department of pediatric and preventive dentistry, college of dentistry, university of baghdad, iraq. *correspondence email: maymuna.hassan1901@codental.uobaghdad.edu.iq abstract: background: vitamin d deficiency is a problem for pregnant women, and it affects general and oral health. this problem increases as vitamin d requirements increase during pregnancy. this study was conducted among pregnant women in urban and rural areas in order to assess the relation between salivary vitamin d3 and dental caries. materials and methods: in this comparative cross-sectional study, all women participating were attending the primary health care centers in baghdad city in al-karkh sector, they were with age ranged from (15-44) years old. the total number 90 pregnant women in the second trimester only which include: the first group consists of (45) pregnant women attendance seeking dental treatment in urban areas, the second group consists of (45) pregnant women attendance seeking dental treatment in rural areas. collection of the unstimulated saliva was done according to tenovuo (1996). after that the clinical examination of dental caries dmft/s was performed according to the world health organization in (2013). results: the findings of this study revealed that the percentage of pregnant women in the age range of 15– 29 years was higher in the rural areas than in the urban areas. while those in the age range of 30–44 years were higher in the urban areas. regarding the age, the percentage of dental caries experience was increased with age. regarding the area, the percentage of dental caries was higher in the urban area than in the rural area. the highest mean value of dmft was found in the urban area, with no significant differences. while the highest mean value of dmfs was found in the rural areas with no statistically significant difference, except the fs, where was statistically significant and higher in the urban areas. the mean value of salivary vitamin d3 was found to be higher in rural areas than in urban areas, although statistically non-significant. the correlation between dental caries experience (dmft/s) and salivary vitamin d3 level was statistically non-significant among urban and rural pregnant women, except in the urban areas where the dmfs was found to be significant with salivary vitamin d3. conclusions: according to the results of this study, there was a non-significant negative correlation between dental caries and salivary vitamin d3 among pregnant women in urban and rural areas. except, the correlation between dental caries experience by surfaces and salivary vitamin d3 was negative and significant among urban pregnant women. keywords: dental caries, pregnant women, vitamin d3. introduction ''dental caries is a localized, chemical dissolution of a tooth surface brought about by metabolic activity in a microbial deposits (a dental biofilm) overing a at any given time''(1). it affects people of all ages, races, and genders (2). this process was aided by a number of bacteria, especially streptococcus mutans, which are highly cariogenic. dental caries, on the other hand, is not thought to be a classic infectious disease; rather, it is seen as a multifactorial disease involving a variety of risk factors. it occurs when there is an environmental disturbance inside the oral cavity, which is supplemented by other external influences (3). received date: 15-01-2022 accepted date: 26-02-2022 published date: 15-12-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/li censes/by/4.0/). https://doi.org/10.26477/ jbcd.v34i4.3271 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3214 https://doi.org/10.26477/jbcd.v34i3.3214 j. bagh. coll. dent. vol. 34, no. 4. 2022 abed and radhi 2 vitamin d plays an important role in calcium absorption and musculoskeletal health regulation(4). it has also been linked to cardiovascular health, immunological response, wound healing, and prevention of cancer (5-9). teeth are mineralized organs surrounded by alveolar bone and formed by enamel, dentin, and cementum, which are three distinct hard tissues. while tooth mineralization is similar to skeletal mineralization, if mineral metabolism is disrupted, failures similar to those seen in bone tissue will occur.vitamin d is essential for bone and tooth mineralization, and when levels aren't controlled, it can result in the "rachitic tooth," a deficient and hypomineralized organ that's prone to fracture and decay (10,11). two mechanisms for vitamin d's effect on caries have been proposed. vitamin d is thought to work through the vitamin d receptor, and polymorphisms in this gene have been linked to tooth decay(12). low vitamin d levels can promote topical demineralization of teeth, similar to its known effect on bone, by lowering calcium and phosphate ions concentrations. vitamin d can influence caries through immunological factors like cathelicidins(13,14). iraqi study worked among nutritional rickets children revealed the dmfs was lower than control group(15).pregnancy is a stressful disorder that causes significant changes in metabolic and physiological functions extent(16). as a result, the most significant physiological and hormonal changes in a woman's life occur during pregnancy(17). and one of the focus areas for these changes is the oral cavity(18). pregnant women are more likely to develop tooth decay for a variety of reasons, including a decrease in salivary ph in the oral cavity, sweet food preferences, and a lack of focus on oral health(16,18,19). unfortunately, becoming pregnant can lead to unhealthy behaviors. these behaviors may include a preference for certain food groups at the expense of others, as well as snacking on harmful foods, such as candy, on a regular basis in order to relieve nausea, increased consumption of processed carbohydrates will give a favorable environment for cariogenic bacteria, potentially increasing the risk of tooth decay in certain people (20). in iraq, research compared pregnant women to non-pregnant women and found that pregnant women had more dental caries than non-pregnant women (21-25). as far as, no iraqi study has been carried out to measure the level of salivary vitamin d3 and its relation to dental caries among pregnant women in urban and rural areas. therefore, this study was conducted. we suggest the null hypothesis that there is no relation between the salivary vitamin d3 level and dental caries. materials and methods the present research was carried out between 13th of april and the 8th of september. the pregnant women were examined during this time; the saliva samples were collected. before starting the study, approval was achieved from the ministry of health for women examinations verbal consents were obtained from all women and the ethical committee had accepted the study's protocol in university of baghdad, college of dentistry. in this comparative cross sectional study, all women participating in this study were attending the primary health care centers in baghdad city in al-karkh sector, they were with the age ranged from (15-44) years. the total number 90 pregnant women in the second trimester only which include. the first group consists of (45) pregnant women attendance seeking dental treatment in urban areas, the second group consists of (45) pregnant women attendance seeking dental treatment in rural areas. collection of the un-stimulated saliva were done according to tenovuo.(26)the saliva is allowed to accumulate in the floor of the mouth and the pregnant woman spits out it into the disposable graduated test tube. saliva samples were taken to a lab at a primary health care center and centrifuged for 15-20 minutes at (3000) rpm. the clear samples was collected by a micropipette and stored into eppendrouftubes at (-20 c) in a deep freeze until the time of biochemical analysis. after collection of saliva the clinical examination of dental caries dmft/s was performed according to who.(27) the concentration of salivary vitamin d3 was detected by an enzyme linked immune-sorbent assay (elisa) using a salivary vitamin d3 kit. j. bagh. coll. dent. vol. 34, no. 4. 2022 abed and radhi 3 exclusion criteria: the pregnant women should be: • free from any systemic diseases • not receiving any multivitamins, calcium and vitamin d3 supplements • non smokers statistical analysis: the statistical package for social science was used to conduct the statistical analysis (spss version -22, chicago, illionis, usa). the mean and standard error were calculated using descriptive analysis with a simple chart bar. the difference between two groups was tested using inferential analysis as an independent sample t test parametric test. for the linear correlation between two quantitative variables, the pearson correlation parametric test was used. results the results showed that the percentage of pregnant women in the age range of 15–29 years was higher in the rural areas than in the urban areas. while those in the age range of 30–44 years were higher in the urban areas. as shown in the table 1. table 1: the distribution of pregnant women according to the age and area area age (years) urban rural 15-29 30 44.78% 37 55.22% 30-44 15 65.21% 8 34.78% regarding the descriptive and statistical tests of age by area, the mean value of age in urban pregnant women was found to be 26.20 and the mean value of age in rural pregnant women was found to be 23.4 as shown in table (2). table 2: descriptive and statistical tests of pregnant women in the second trimester regarding age by area pregnancy area mean se 2nd trimester urban 26.20 1.041 rural 23.41 0.774 the results of the distribution of caries among pregnant women by age and area were reported that pregnant women in the age range of 30–44 were found to have higher percentages of caries than those in the age range of 15–29. regarding area, the percentage of caries was higher in the urban area than in the rural area table 3. table 3: distribution of caries status by age and area vars. n. % age (years) 15-29 53 79.10 30-44 22 95.65 area urban 41 91.11 rural 34 75.56 j. bagh. coll. dent. vol. 34, no. 4. 2022 abed and radhi 4 the results demonstrated that the highest mean value of dmft was found in the urban area, with no significant differences as shown in the table 4. table 4: descriptive and statistical tests of dental caries experience (dmft) among pregnant women by area pregnancy area urban rural mean ±se mean ±se t test p value 2nd trimester dt 0.696 0.234 1.614 0.440 1.864 0.066 mt 0.717 0.169 0.614 0.244 0.352 0.726 ft 2.065 0.435 1.068 0.267 1.935 0.056 dmft 3.478 0.499 3.295 0.640 0.226 0.821 concerning dental caries experience by surfaces the results show that the highest mean values of dmfs were found in the rural areas with no statistically significant difference, except the fs, where was statistically significant and higher in the urban areas. descriptive and statistical tests of caries experience by surfaces and areas are shown in table 5. table 5: descriptive and statistical tests of dental caries experience (dmfs) among pregnant women by area. pregnancy area urban rural mean ±se mean ±se t test p value 2nd trimester ds 2.304 0.993 4.864 1.746 1.289 0.201 ms 3.543 0.829 3.068 1.219 0.325 0.746 fs 3.543 0.721 1.750 0.517 2.005 0.048* dmfs 9.391 1.555 9.682 2.484 0.100 0.921 *=significant statistically at p<0.05. in reference to vitamin d3 the findings revealed that the mean values and standard error of salivary vitamin d3 were found to be higher in rural areas than in urban areas, although statistically non-significant, as shown in figure 1. figure 1: descriptive and statistical tests of vitamin d3 among area. 10 15 20 urban rural s.vit d3 urban rural m e a n j. bagh. coll. dent. vol. 34, no. 4. 2022 abed and radhi 5 the correlation of salivary vitamin d3 with all variables in the urban and rural areas was negative and weak, but not significant. except in the urban areas, the dmfs was found to be significant with vitamin d3 as shown in table 6. table 6: correlation between dental caries experience by teeth, dental caries experience by surfaces and salivary vitamin d3. area vitd3 r p value urban dt -0.186 0.216 mt -0.111 0.463 ft -0.184 0.220 dmft -0.285 0.055 ds -0.240 0.108 ms -0.109 0.472 fs -0.205 0.171 dmfs -0.306 0.038* rural dt 0.051 0.742 mt -0.172 0.264 ft -0.097 0.531 dmft -0.071 0.647 ds -0.073 0.639 ms -0.172 0.264 fs -0.051 0.744 dmfs -0.146 0.344 discussion this study looked at the relation between salivary vitamin d3 and dental caries among pregnant women in urban and rural areas. regarding the personal characteristics, most pregnant women were under 30 years of age. dental caries was measured by dmft/s and they were grouped according to who.(27)in terms of age, the present study's findings revealed that dental caries increase with age, which was consistent with iraqi study.(28) this could be explained by the fact that age is the major risk factor for dental caries.(29) also be related to the accumulative and irreversible nature of dental caries.(30)regarding to the area where the percentage of dental caries was higher in the urban area and this disagreed with study by siddiqui et al. (2018) where the highest percentage of dental caries was in the rural areas. (31)and this may be related to the low level of vitamin d3 in urban areas in this study. as a result, a deficiency in this vitamin causes a variety of issues, including changes in the composition and mineralization of teeth and bones. (32) regarding to the caries experience by teeth and surfaces where the dmft higher in urban pregnant women and this could be related to the ft mean value which was higher than other components of dmft and this good indication that the women visit the dentist for filling. while the dmfs was higher in the rural pregnant women and this may be related to the ds mean value where was higher than other j. bagh. coll. dent. vol. 34, no. 4. 2022 abed and radhi 6 components of dmfs. rural women's negative attitudes toward dental treatment during pregnancy related to a reduced use of dental services and a high frequency of untreated dental caries.(33)despite this the dental caries is remains a multifactorial disease.(34)in reference to vitamin d3. the findings reported that the mean value in the rural areas was higher than those in the urban areas, but statistically non-significant. this may be explained by their exposure to the sun more than those in the urban areas, the sun is considered the main source of vitamin d3.(35) regarding the correlation between salivary vitamin d3 and dental caries experience in urban pregnant women, there was a statistically significant negative correlation between dmfs and salivary vitamin d3, and this agreed with botelho et al. (36). this could be explained by that when the vitamin d3 level decreases, it leads to an increase in dental caries because it is essential for bone and tooth mineralization, and when levels aren't controlled, it can result in hypomineralized teeth and decay.(37,38) conclusion the findings of the present study concluded that there were negative correlation of dental caries with salivary vitamin d3 levels among pregnant women in urban and rural areas. pregnant women need more education and encouragement for oral health care and visiting the dentist during pregnancy. conflict of interest: none. references 1. kidd, e. a. & fejerskov, o. (2016). essentials of dental caries, oxford university press. 2. masthan, k. (2011). textbook pediatric oral pathology, jaypee 3. fejerskov, o. (2004). changing paradigms in concepts on dental caries: consequences for oral health care. caries research, 38, 182-191. 4. dusso as, brown aj & e, s. 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(2009). vitamin d status and the risk of cardiovascular disease death. american journal of epidemiology, 170, 1032-1039. 9. foster, b. l., nociti jr, f. h. & somerman, m. j. (2014). the rachitic tooth. endocrine reviews, 35, 1-34. 10. d’ortenzio, l., kahlon, b., peacock, t., salahuddin, h. & brickley, m. (2018). the rachitic tooth: refining the use of interglobular dentine in diagnosing vitamin d deficiency. international journal of paleopathology, 22, 101-108. 11. hu, x. p., li, z. q., zhou, j. y., yu, z. h., zhang, j. m. & guo, m. l. (2015). analysis of the association between polymorphisms in the vitamin d receptor (vdr) gene and dental caries in a chinese population. genet mol res, 14, 11631-8. 12. gombart, a. f. (2009). the vitamin d–antimicrobial peptide pathway and its role in protection against infection. future microbiology, 4, 1151-1165. j. bagh. coll. dent. vol. 34, no. 4. 2022 abed and radhi 7 13. youssef, d. a., miller, c. w., el-abbassi, a. m., cutchins, d. c., cutchins, c., grant, w. b. & peiris, a. n. (2011). antimicrobial implications of vitamin d. dermato-endocrinology, 3, 220-229. 14. rawi, n. a. a. & jameel, s. a. (2019). assessment of caries experience, enamel defects and selected salivary biomarkers in children with nutritional rickets. journal of baghdad college of dentistry, 31. 15. soulissa, a. g. (2014). hubungan kehamilan dan penyakit periodontal. jurnal pdgi, 63, 72. 16. laine, m. a. (2002). effect of pregnancy on periodontal and dental health. acta odontologica scandinavica, 60, 257-264. 17. amar, s. & chung, k. m. (1994). influence of hormonal variation on the periodontium in women. periodontology 2000, 6, 79-87. 18. edwina a., k. m. (2005). essentials of dental caries. 3rd ed. oxford. .123-166. 19. kornman, k. s. & loesche, w. j. (2008). the subgingival microbial flora during pregnancy. journal of periodontal research, 15, 111-122. 20. chour, g. v. & chour, r. g. (2014). diet counselling–a primordial level of prevention of dental caries. iosr-jdms, 13, 64-70. 21. suliaman, a. (1995). oral health status and cariogenic microflora during pregnancy. a master thesis, college of dentistry, university of baghdad. 22. yas, b. (2004). evaluation of oral health status treatment needs knowledge, attitude and behavior of pregnant women in baghdad governorate. m. sc., thesis, college of dentistry, university of baghdad. 23. al-zaidi, w. (2007). oral immune proteins and salivary constituents in relation to oral health status among pregnant women. ph. d. thesis, college of dentistry, university of baghdad. 24. issa, z. (2011). oral health status among groups of pregnant and lactating women in relation to salivary constituents and physical properties. master thesis submitted to the college of dentistry, university of baghdad. 25. mutlak, n. q. (2016). selected salivary physico-chemical characteristics in relation to oral health status for a sample of pregnant women. university of baghdad. 26. tenovuo j, lagerlöf f.saliva (1996) in: textbook of clinical cariology. in: thylstrup a and fejerskov o, eds. 27. 2nded. munksgaard, copenhagen: denmark; p.17-44. 28. world health organization. oral health surveys: basic methods. world health organization; 2013. 29. hussein, z. (2014). dental caries and treatment needs among 16-18 years old high school girls, in relation to oral cleanliness, parent's education and nutritional 30. hiremath, s. (2011). textbook of preventive and community dentistry, elsevier india. 31. rao, a. (2012). principles and practice of pedodontics, jp medical ltd. 32. siddiqui, t. m., akram, s., wali, a., mahmood, p. & rais, s. (2018). dental caries and gingivitis amongst pregnant women: a sample from urban and rural areas of karachi. pakistan oral & dental journal, 38, 88-91. 33. hujoel pp (2013). vitamin d and dental caries in controlled clinical trials: systematic review and meta-analysis. nutrition reviews. feb 1;71(2):88-97. 34. mital, p., agarwal, a., raisingani, d., mital, p., hooja, n. & jain, p. (2013). dental caries and gingivitis in pregnant women. age, 25, 166. 35. silk, h., douglass, a. b., douglass, j. m. & silk, l. (2008). oral health during pregnancy. american family physician, 77, 1139-1144. 36. wilson, l. r., tripkovic, l., hart, k. h. & lanham-new, s. a. (2017). vitamin d deficiency as a public health issue: using vitamin d2 or vitamin d3 in future fortification strategies. proceedings of the nutrition society, 76, 392-399. j. bagh. coll. dent. vol. 34, no. 4. 2022 abed and radhi 8 37. botelho, j., machado, v., proenca, l., delgado, a. s. & mendes, j. j. (2020). vitamin d deficiency and oral health: a comprehensive review. nutrients, 12, 1471. 38. d’ortenzio, l., kahlon, b., peacock, t., salahuddin, h. & brickley, m. (2018). the rachitic tooth: refining the use of interglobular dentine in diagnosing vitamin d deficiency. international journal of paleopathology, 22, 101-108. 39. foster, b. l., nociti jr, f. h. & somerman, m. j. (2014). the rachitic tooth. endocrine reviews, 35, 1-34. بغداد مدينة في الحوامل النساء لدى االسنان بتسوس وعالقته اللعابي 3 د فيتامين العنوان: الشيخ راضي جعفر ندى, عبد طارق ميمونة الباحثون: المستخلص: هذه أجريت. الحمل أثناء د فيتامين متطلبات زيادة مع المشكلة هذه تزداد. الفم وصحة العامة الصحة على ويؤثر ، الحامل للمرأة مشكلة د فيتامين نقص:الخلفية .األسنان وتسوس اللعابي 3 د فيتامين بين العالقة تقييم أجل من والريفية الحضرية المناطق في الحوامل النساء بين الدراسة قطاع في بغداد مدينة في األولية الصحية الرعاية مراكز على يترددن المشاركات النساء جميع كانت ، المقارنة المقطعية الدراسة هذه في:العمل وطرق المواد ( 45) من تتكون األولى المجموعة -: تشمل والتي فقط الثاني الفصل في حامل سيدة 90 اإلجمالي العدد بلغ . سنة( 44-15) بين أعمارهن وتراوحت ، الكرخ تم . الريفية المناطق في أسنان عالج عن تبحث حامل امرأة( 45) من الثانية المجموعة وتتكون ، الحضرية المناطق في األسنان عالج عن تبحث حامل امرأة العالمية الصحة لمنظمة وفقًا dmft / s األسنان لتسوس السريري الفحص إجراء تم ذلك بعد (. 1996) عام tenovuo لـ وفقًا المحفز غير اللعاب جمع .(2013) عام كانت بينما . الحضرية المناطق في منها الريفية المناطق في أعلى كانت سنة 29-15 العمرية الفئة في الحوامل النساء نسبة أن الدراسة هذه نتائج كشفت: النتائج بالمنطقة يتعلق فيما . العمر تقدم مع تزداد األسنان تسوس لتجربة المئوية النسبة فإن ، بالعمر يتعلق فيما . الحضرية المناطق في أعلى سنة 44-30 العمرية الفئة مع ، الحضرية المنطقة في dmft قيمة متوسط أعلى على العثور تم. الريفية المناطق في منها الحضرية المناطق في أعلى األسنان تسوس نسبة كانت ، ، إحصائياً به معتد فرق وجود عدم مع الريفية المناطق في dmfs متوسط قيمة أعلى على العثور تم حين في. إحصائية داللة ذات فروق وجود عدم المناطق في أعلى لتكون اللعابية3د لفيتامين المتوسطة القيمة على العثور تم. الحضرية المناطق في وأعلى إحصائية داللة ذات كانت حيث ، fs باستثناء فيتامين ومستوى (dmft / s) األسنان تسوس تجربة بين العالقة كانت. غيرإحصائية داللة ذات أنها من الرغم على ، الحضرية المناطق في منها الريفية بفيتامين معنوي dmfs أن وجد حيث الحضرية المناطق باستثناء ، والريفية الحضرية المناطق في الحوامل النساء بين غيرإحصائية داللة ذات اللعابي3د .اللعابي3د الحضرية المناطق في الحوامل النساء بين اللعابي 3د وفيتامين األسنان تسوس بين معنوية غير سلبية عالقة هناك كان ، الدراسة هذه لنتائج وفقا :االستنتاجات .الحضرية المناطق في الحوامل النساء بين ومعنوية سالبة اللعابي3د وفيتامين األسطح طريق عن األسنان تسوس تجربة بين العالقة كانت ، عدا فيما . والريفية meena.doc j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 169 the effect of inhaled corticosteroid on oral conditions among asthmatic children meena o. abdul wadood b.d.s. (1) zainab a.a. al-dahan, b.d.s., m.sc. (2) abstract background: inhalation therapy has been employed as the mainstay of the treatment in chronic respiratory diseases such as asthma, patients who taking asthma medication may be at risk of many health problems including oral health .the purpose of this study was to assess the local effect of ics on oral tissue by measuring candida albicans count colonies in saliva among12 years old asthmatic children who were collected from alzahra center advisory for allergy and asthma, and compares them with non asthmatic children of the same age and gender. material and methods: the total sample involved sixty children of 12 years old, thirty asthmatic children who received medium dose of ics/day (200-400 microgram/day) for 2 years and 30 non-asthmatic children. the unstimulated saliva was collected under standard condition and then analyzed for candida albicans colony counts assessment. results: the mean rank of the colony counts were found to be higher among asthmatic than nonasthmatic children with statistically significant difference (p<0.05). concerning each gender, the results illustrated that the difference for boys was statistically non significant (p>0.05), while for girls the difference was statistically significant (p<0.05). concerning gender differences, data analysis showed that the mean rank of colony counts were found to be higher among girls than boys in both groups with statistically non-significant difference (p>0.05) conclusions: the findings of the present study showed that the asthmatic disease and ics treatment play an important role in elevation of the candida prevalence in oral cavity. keywords: asthma, candida, inhaled corticosteroid. (j bagh coll dentistry 2015; 27(1):169-174). introduction inhaled corticosteroid (ics) therapy is commonly used for treatment of allergic phenomenon such as asthma (1). patients taking asthma medication may be at risk of oral candidiasis (2). the local mode of action of ics lead to local adverse effects of ics on oral tissue (3, 4), the one most common local adverse effect of ics is oral candidiasis (5). previous studies which regarding the incidence of candida in inhaled corticosteroid treated patients reported divergent results. dubus et al. (6), ellepola and samaranayake (7), fukushima et al. (8), and fukushima et al. (9), suggested that the inhaled corticosteroids in addition to other host factors could potentially increase the risk of oral candidiasis. on the other hand, komiyama et al. (10), reported that the percentage of candida were 43.33% in thirty asthmatic children of 4 -12 years old who treated with corticosteroids for period range between 2-48 months and were 30% in thirty control children with no significant difference between them and no correlation was observed between the number of colony-forming units of candida per ml of saliva (cfu/ml), dose of medication and time of treatment. while adams et al. (11), rachelefsky et al. (12), and van boven et al. (13), had been conducted the association between ics and the occurrence of oral candidiasis regardless of the dose. (1) m.sc. student department of pedodontics and preventive dentistry, collage of dentistry, baghdad university. (2)professor, department of pedodontics and preventive dentistry, collage of dentistry, baghdad university söderling et al. (14), and cortelli et al. (15), reported that females tended to have higher candida prevalence than males. while lotti et al. (16), and reynaud et al. (17), found no relationship between the candida counts and age or gender. saliva is a diagnostic and monitoring method for many infectious diseases(18), saliva contain a large numbers of proteins that participate in protection of oral tissue in addition to several peptides with fungal killing activity that had been identified (19), in this way saliva determined the composition of the oral micro flora and controlled oral health(20), by maintaining the integrity of the oral hard tissues and soft tissues through the salivary immune and non-immune defense proteins (21-23). this study was performed to provide greater visibility to the harmful effects of beclamethasone inhaler on oral pictures among asthmatic children aged 12 years in comparison to control group to evaluate the association between ics, asthma and oral health which include salivary candida prevalence. materials and methods in the present investigation, the study group included 30 asthmatic children aged 12 years old who received medium dose of ics/day (200-400 microgram/day) for 2 years, they were examined in alzahra center advisory for allergy and asthma during the period from 20 december 2013 till the end of march 2013. the control group included 30 non asthmatic children who possess as much as similarity as possible to the j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 170 study group with regard to age, gender, social structure and geographic position except in asthmatic condition. both groups should not possess any systemic disease that could effect on salivary analysis. the collection of unstimulated saliva was performed under standard condition according to the instructions cited by navazesh and kumer (24) and immediately placed it in ice box until reach the microbiological laboratory. at the ministry of science and technology fungal laboratory, each salivary sample of control and study group was dispersed using vortex mixer for 1 minute and then tenfold dilutions were performed by transferring 0.1 ml of each suspension from each tube of the control and study to 0.9 ml of sterile phosphate buffer saline (ph 7.0), then from dilution salivary samples, 0.1 ml was taken and spread on the sabourauds dextrose agar (sda), the plates were incubated aerobically for 48 hr at 37°c, then the colony–forming unit per milliliter was counted (cfu/ ml) for all the plates. the identification of candida albicans (c.albicans) can be done through: (a) colony morphology: colonies of c. albicans appeared smooth creamy in color with a yeast odor and typically medium size (1.5-2) mm diameter which later developed into high convex, off-white larger colonies after 2 days (25,26). (b) gram stain: a small inoculum from a discrete, singly isolated colony was picked up from sda plates separately under sterilized conditions and subjected to gram’s stain according to koneman et al. (27).(c) germ tubes formation: very small inoculums from isolated colonies was suspended in 0.5 ml of normal human serum. the inoculated tubes were incubated at 37°c for 3hr. after incubation, a drop of yeast suspension was placed on clean microscopic slide covered with cover slip and examined under low power magnification (28). intra and inter calibration were performed to overcome any problems that could faced during the research. statistical analysis and processing of the data were performed using the spss version 19. after exploring the data, it had been found that the data were not normally distributed. the non-parametric test mann-whitney test was utilized for the parameters of data which were not normally distributed, in this test the median and mean rank were used to determine and analyze the differences between the study and control groups. the confidence level was accepted at the level of less than or equal to 5%. the highly confidence level was accepted at the level of less than or equal to 1%. results the description of the samples is illustrated in table (1). the c. albicans carrier group of asthmatic children was represented by 60%, while the c. albicans carrier group of non-asthmatic children was represented by 33.33%. the asthmatic children without c. albicans were represented by 40%, while the non-asthmatic children without c. albicans were represented by 66.67%. identification of c. albicans: (a)colony morphology: colony of c.albicans appeared smooth, creamy in color with yeast odor and typically medium sized (1.5-2 mm) diameter which later develop into high convex, offwhite large colonies after 2 days. figure (1) (b)microscopic examination: the slide was examined under light microscope, the rounded or oval yeast cells were stained gram positive (gram staining test). figure (2) (c)germ tube formation: under light microscope (100 x magnification), the presence of germ tubes were the characteristic of c.albicans. figure (3) the differences in c.albicans x102 quantities (cfu /ml) between asthmatic and nonasthmatic children are demonstrated in table (2). results reported that the mean rank of the colony counts were found to be higher among asthmatic than nonasthmatic children with statistically significant difference (mann whitney=311.5, z= 2.180, p=0.029). concerning each gender, the results revealed that the difference for boys was statistically non significant (mann whitney=99, z= -1.130, p=0.259), while for girls the difference was statistically significant (mann whitney=58, z= -2.087, p=0.037). table (3) shows comparison between genders in asthmatic and non-asthmatic children, the mean rank of colony counts were found to be higher among girls than boys with statistically nonsignificant difference (p>0.05). table 1: description of the experimental samples groups with candida (carrier) without candida no. % no. % asthmatic 18 60 12 40 non-asthmatic 10 33.33 20 66.67 j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 171 table 2: difference in salivary c.albicans x 102 quantities (cfu /ml) between the asthmatic and nonasthmatic children variables genders asthmatic nonasthmatic difference no. median mean± s.d. mean rank no. median mean±s.d. mean rank u test zvalue pvalue c. albicans x102 (cfu /ml) boys 16 2 24.25±69.07 18.31 16 1 1.81±2.83 14.68 99 -1.130 0.259 girls 14 1 15.21±29.97 17.36 14 0 1±2.94 11.64 58 -2.087 0.037* total 30 1 20.03±53.77 35.12 30 0 1.43±2.86 25.88 311.5 -2.180 0.029* (non sig. at p>0.05;*s: sig. at p<0.05 between asthmatic and nonasthmatic children) table 3: genders difference for asthmatic and non-asthmatic children asthmatic nonasthmatic variables genders no. median mean rank u test z-value pvalue no. median mean rank u test z-value pvalue c. albicans x102 (cfu) boys 10 10.5 9.4 39 -0.090 0.929 7 1 5.14 8 -0.610 0.542 girls 8 11.5 9.62 3 2 6.33 (non sig. at p>0.05 between asthmatic and nonasthmatic children) figure 1: c. albicans colonies on sda (15x magnification) figure 2: gram’s stain of c. albicans colonies showing gram positive stains (100x magnification). j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 172 figure 3: germ tube formation discussion data analysis of the current study concluded that the percentage of c. albicans in carrier group of asthmatic children were higher than nonasthmatic children and the mean rank of the colonies counts were found to be higher among asthmatic than nonasthmatic children with statistically significant difference. these finding were in angreement with dubus et al. (6), ellepola and samaranayake (7), fukushima et al. (8), adams et al. (11), fukushima et al. (9), rachelefsky et al. (12), and van boven et al. (13),and in disagreement with komiyama et al. (10), generally it is difficult to compare the prevalence of c. albicans (cfu/ml) reported by different studies in literature with that of the present study, this might be due to variability in the type and dose of ics used, frequency of the use of medication, patient compliance with instructions for administration, duration of drug therapy and the mode of delivery (direct or with spacer) or due to the hospital-based population of children with moderate asthma or due to methodologic issues such as study design, sample size, age, gender and length of observations .the findings of the current study can be explained by the fact that the mechanisms by which ics cause local adverse effects have appear to be related to the deposition of the active ics into the oral cavity, since the major proportion of the inhaled drug is retained in the oral cavity and oropharynx and only 10-20% reach to the lung during drug administration (29), so it might interfere with normal physiology of oral tissues(3), and it might interferes with the cellmediated immunity and involve the inhibition of normal host defense functions of neutrophils, macrophages and t lymphocytes at the oral mucosal surface and the esophagus that cause local immunosuppressant in oral cavity(7,30), the decreased efficiency of the immune system may in turn allow an opportunistic infection of candida (31), or ics might cause an increase in salivary glucose levels, which stimulate growth, proliferation and adhesion of candida to oral mucosa (32) and these events accompanied by acid production and a significant concomitant reduction in ph to very low levels (33,34). however, the reduced ph levels may potentiate candida virulence by enhancing acidic proteases and phospholipases enzymes of the yeast (35). in addition the results of the this study might be due to the presence of some predisposing factors in asthmatic children who treated with ics that influence candida carriage more than the nonasthmatics which include the lack of salivary flushing action and absence of antifungal salivary constituents such as lactoferrin and lysozyme which was attributed to underlying disease and medication intake, the deficiency of salivary iga which caused by ics(36,9), the significant alterations in the microbial flora which occur with ics, the intake of medication at night before going to bed due to poor patient awareness, no oral hygiene measures after medication, the diminution of salivation and lack of masticatory movements during the night might increased c. albicans prevalence which predisposed to candidosis (37) . furthermore this study showed that the prevalence of colonies counts was higher among girls as compared with boys among asthmatic and non asthmatic children with non-significant difference, these results were in agreement with söderling et al. (14), and cortelli et al. (15) and in disagreement with lotti et al. (16), and reynaud et al. (17), the disagreement with these studies could be due to ethnic differences, sample size and j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 173 selection differences. this result might be attributed to the lower salivary secretion in females than males even after controlling other variables such as underlying disease and medications (38), which might be attributed to different volumes of salivary glands as described by inoue et al. 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14(12): 801-9. j bagh college dentistry vol. 27(1), march 2015 the effect of pedodontics, orthodontics and preventive dentistry 174 30. fidel pl. distinct protective host defenses against oral and vaginal candidiasis. med mycol 2002; 40: 359– 75. 31. park kk, brodell rt, helms se. angular cheilitis, part 2: nutritional, systemic, and drug-related causes and treatment. cutis 2011; 88(1): 27-32. 32. samaranayake yh, cheung bpk, parahitiyawa n, et al. synergistic activity of lysozyme and antifungal agents against candida albicans biofilms on denture acrylic surfaces. oral biol j 2009; 54(2): 115-26. 33. samaranayake lp, hughes da, weetman and tw macfarlane: growth and acid production of candidaspecies in human saliva supplemented with glucose. j oral pathol 1986; 15:251-4. 34. al-jboori zj, al-obaidi wa, al-mashhadani a. salivary candida albicans in relation to oral health status among 4-5years old children in baghdad city. j bagh coll dentistry 2006; 18(3): 73-7. 35. krishnan pa. fungal infections of the oral mucosa. indian j dent res 2012; 23(5): 650-9. 36. torres sr, peixoto cb, caldas dm, silva eb, akiti t, nucci m, et al. relationship between salivary flow rates and candida counts in subjects with xerostomia. oral surg oral med oral pathol oral radiol endod 2002; 93:149–54. 37. shashikiran nd, reddy vv, raju pk. effect of antiasthmatic medication on dental disease: dental caries and periodontal disease. j indian soc pedod prev dent 2007; 25(2): 65-8. 38. navazesh m, brightman vj, pogoda jm. relationship of medical status, medications, and salivary flow rates in adults of different ages. oral surg oral med oral pathol oral radiol endod 1996; 81:172-6. 39. inoue h, ono kw, masuda y, morimoto t, tanaka m, yokota k . gender difference in unstimulated whole saliva flow rate and salivary gland sizes. arch oral biol 2006; 51(12):1055-60. لخالصھا الصحیة المشاكل من للكثیر عرضةقد یكونون الربو أدویة یتناولون الذین المرضىان . الربو مثل المزمنة التنفسیة األمراض لعالج ساسیةا دعامةق یستخدم كستنشااال عالجان : الخلفیة األطفال المصابین لعاب مستعمرات المبیضات في على انسجھ الفم وذلك بواسطھ عد )ics(استنشاق كورتیكوستیروید تقییم تاثیران الھدف من ھذه الدراسھ ھو. الفم صحة ذلك في بما .مع األطفال غیر المصابین بالربو من نفس العمر والجنس مومقارنتھ الذین یراجعون مركز الزھراء االستشاري للحساسیھ والربو سنة 12بعمربالربو طفال غیر 30لسنتین و ) الیوم/ ics )200-400μgمصابین بالربو والذین حصلوعلى جرعة متوسطة من 30(سنة 12بعمر طفال 60تتكون العینة الكلیة من :المواد والطرق .عد وحدة مستعمرات المبیضات ل تحلیلھ تمبعد ذلك و ظروف موحدة تحت محفز من العینة الكلیةالجمع اللعاب الغیر وقد تم). مصابین بالربو لكال الجنسین مع وتم الحصول على نفس النتائج عنھ لغیرالمصابین مع وجود فروق ذات قیمھ معنویھ والمصابین بالرب االطفال بینالمستعمرات أعلى بكثیر إن رتبة متوسط :النتائج .لالناث بالنسبھ للذكور بینما كانت ذات قیمھ معنویھ فروق ذات قیمھ معنویھعدم وجود . الفم تجویف في المبیضات انتشار ارتفاع في ھاما دورا لعبیاستنشاق كورتیكوستیروید و الربو مرض أن الدراسة ھذه ائجنت أظھرت :االستنتاج .استنشاق كورتیكوستیروید المبیضات، الربو، :الكلمات الرئیسیھ rana f.docx j bagh college dentistry vol. 28(2), june 2016 the marginal fitness restorative dentistry 30 the marginal fitness of cad/cam all ceramic crowns constructed by two types of direct digitization techniques (an in vitro study) rana m. khdeir, b.d.s. (1) adel f. ibraheem, b.d.s., m.sc. (2) abstract background: in capturing a negative image, the digital impression secures a digital record for the purposeof designing and creating restorations. the introduction of scanning system presents a paradigm shift in the way of the dental impression procedure and encourages the accuracy of obtained restoration especially in the marginal area as a result of producing accurate final impression the digital system offers many advantages over the conventional method.. the objective of this present in vitro study was to evaluate the marginal fitness of all ceramic crowns fabricated by direct digital scanning of the prepared tooth using two types of intra-oral cameras (bluecam camera with strip light projection technique and omnicam camera with video sampling technique). materials and methods: sixteen sound upper first premolar teeth of comparable size were collected. standardized preparation of all teeth samples were carried out to receive all ceramic crown restoration with deep chamfer finishing line (1mm), axial length (4mm) and convergence angle (6◦). the specimens divided in to two groups according to the type of digital impression technique: group a, eight prepared teeth scanned directly by bluecam camera; group b, eight prepared teeth scanned directly by omnicam camera. then cad/cam all ceramic crowns constructed for each tooth sample. marginal discrepancy was measured at sixteen points per tooth using digital microscope at (120x) magnification. results: independent sample t-test was used to identify and localize the source of difference among the groups. it was found that there is statistically nonsignificant difference in the marginal gap mean values between (group a and group b). conclusions: from the above result we can conclude that the two types of direct digitization techniques have the same accuracy. key words: marginal fitness, cad/cam system, digital impression. (j bagh coll dentistry 2016; 28(2):30-33). introduction the conventional impression technique for construction of the indirect dental restoration include many steps; preparation of the abutment teeth, impression making, pouring procedure to form master model, wax up and finally casting, so there are several factors could effect on the accuracy of the traditional impression-making. the introduction of cad/cam systems in 1980s to dental field resolved a wide range of these limitations found in the conventional impression techniques since they provide speed, property of storing captured images indefinitely with no distortion (1). the early systems of cad/cam using extraoral scanners that enable scanning the stone models after taking impressions or the impression itself were scanned(2). nowadays many companies developed an in-office scanners that enhance capturing of three dimensional virtual images of the prepared teeth intra-orally without needing to conventional impression making, then the restorations were designed on a computer using cad software relies on the captured data that acts as a virtual wax-up. (1)master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. the introduction of scanning system presents a paradigm shift in the way of the dental impression procedure and encourages the accuracy of obtained restoration especially in the marginal area as a result of producing accurate final impression because any inaccuracy in impression results in crown restoration having marginal discrepancy that compromises preexisting periodontal diseases, secondary caries and eventually crown failure (3,4). materialsand methods sixteen sound recently extracted maxillary 1st premolar were collected, the root of each tooth were embedded in an individual block of acrylic to about (3mm) by the aid of surveyor. each specimen was prepared to receive all ceramic crown with flat occlusal surface, (1mm) deep chamfer finishing line, 6 degree axial tapering and (4mm) axial length (fig. 1). prior to scanning,each specimen with its acrylic base was reseated in its corresponding place inside a modified mannequin to replicate natural dental arch, so each tooth sample will have adjacent and opposing teeth which was needed in the scanning procedure (fig. 2) j bagh college dentistry vol. 28(2), june 2016 the marginal fitness restorative dentistry 31 figure 1: the final preparation of the tooth sample. figure 2: the modified custom made model the teeth samples in (group a) were scanned using intra-oral digital scanning by bluecam camera (fig. 3), and (group b) were scanned using intra-oral digital scanning by omnicam camera (fig:4), all the scanning procedure were done according to the manufacturer’s instructions. the ceramic vita mark ii cad /cam crowns were then constructed for all teeth samples.the crowns for all groups were designed using the biogeneric software according to the recommended parameters, all the information were then sent to the milling machine cerec mc xl. figure 3: scanning with bluecam camera. figure 4: scanning with omnicam camera the marginal fitness of the crowns were calculated by measuring the vertical gap between the margin of tooth and that of the ceramic crown, no any type of cement or luting agent was used to affixthe crown onto the specimenbecause when specimens are cemented, they may lose the precision of the primary adaptation by the effect of cement type, cement viscosity and cementation technique which influence the results (5), but the specimens fixed in place with a specially designed holding device to apply a constant seating of the tested crowns to ensure the accuracy of their examination (6). the area of (mid-buccal, mid-lingual, midmesial, mid-distal) was selected to measure the space between the margin of the tooth and that of the crown during marginal fitness measurement (7,8). the measuring was done by the digital microscope at magnification 120x (figure 5). the digital imageswere captured and measured utilized image j software (image j 1.32, u.s. national institutes of health, bethesda, ma, usa)(9,10) that calculate the value in pixel. the samples were observed and photographed at 120x magnification and calibrated using a photograph of a (1mm) increment take at the same focal lengthand input into (image j) by the option of j bagh college dentistry vol. 28(2), june 2016 the marginal fitness restorative dentistry 32 set scale (11) that converted all calculated readings from pixel to (µm) (fig:6 a and b). figure 5:digital image captured by dinolite digital microscope. figure 6 a and b: calibration the measurements by set scale option. statistical analysis data were collected and analyzed using spss (statistical package of social science) software version 15 for windows xp chicago, usa. the following statistics were used: adescriptive statistic: including mean, standard deviation, statistical tables and graphical presentation by bar charts. binferential statistics: including t-test to see if there were any significant differences between the means of groups. p value of more than 0.05 was regarded as statistically insignificant as follows: p≥0.05 ns non-significant 0.05≥p>0.01 * significant 0.01≥p>0.001 ** highly significant results table 1 showed the descriptive statistics and groups' comparison of vertical marginal gap measured in μm. the results revealed nonsignificant difference between the two groups. table 1: descriptive statistics and comparison of vertical marginal gap for the two groups in (µm). groups descriptive statistics comparison (d.f.=14) n mean s.d. min. max. t-test p-value a 8 36.688 2.018 34.799 40.864 -1.796 0.484 (ns) b 8 34.892 3.723 28.713 39.576 discussion in the present study, all the evaluated values obtained were clinically acceptable(1214) who concluded that marginal discrepancy in the range of (100 um) being clinically acceptable. the results of our study showed that the accuracy difference between the two types of cameras (bluecam camera continuous images techniques and omnicam camera video sampling technique) was statistically non-significant, which is in agreement with the results of previous studies that showed no statistically significant differences between the technique of video sampling and that of stripelight projection (15-17). on the other hand our results reflect a small degree of difference between (bluecam camera 36.688) and (omnicam camera 34.892) which in total agreement with a recent laboratory research which concluded that powder-free and powder-based systems can achieve comparable results (16). the explanation of that difference might be due to the fact that the layer of powder used in scanning procedure of bluecam camera, which is necessary to applied to prevent reflections of glossy surfaces, could lead to inaccurate measurements. this comes j bagh college dentistry vol. 28(2), june 2016 the marginal fitness restorative dentistry 33 in total agreement with other findings (1,17,18) who stated that powdering may adversely affect the marginal fitness instead of improving it even if the scanners' program capable of taking the powder layer into account in the algorithm. references 1. kim sy, kim mj, han js, yeo is, lim yj, kwon hb. accuracy of dies captured by an intraoral digital impression system using parallel confocal imaging. int j prosthodont 2013; 26(2): 161-3 2. miyazaki t,kunii j, kuriyama s, tamaki y. a review of dental cad/cam: current status and future perspectives from 20 years of experience. dent mater j 2009; 28: 44-56. 3. nathan s. birnbaum, heidi b. aaronson, chris stevens, bob cohen. 3d digital scanners: a hightech approach to more accurate dental impressions. j inside dentistry 2009; 5: 4 4. terry da, leinfelder kf, geller w. aesthetic and restorative dentistry: material selection and technique, 2009 5. chan c, haraszthy g, geis-gerstofer j, weber h. the marginal fit of cerestore full-ceramic crowns a preliminary report. j quintessence int 1985; 6: 399402 6. thiab ss, zakaria mr. the evaluation of vertical marginal discrepancy induced by using as cast and as received base metal alloys with different mixing ratios for the construction of porcelain fused to metal copings. al-rafidain dent j 2004; 4(1): 10-19 7. bindl a, mörmann wh. marginal and internal fit of all-ceramic cad/cam crown-copings on chamfer preparations. j oral rehabil 2005; 32: 441-7. 8. naert i, van der donck a, beckers l. precision of fit and clinical evaluation of all-ceramic full restorations followed between 0.5 and 5 years. j oral rehabil 2005; 32: 51-7 9. keith se, miller bh, woody rd, higginbottom fl. marginal discrepancy of screwretained and cemented metal-ceramic crowns on implants abutments. international j oral andmaxillofacial implants 1999; 14: 369. 10. tan pl, gratton dg, diaz-arnold am, holmes dc. an in vitro comparison of vertical marginal gaps of cad/cam titanium and conventional cast restorations. j prosthodont 2008;17(5):378-83. 11. romeo e, iorio m, storelli s, camandona m, abati s. marginal adaptation of fullcoverage cad/cam restorations: in vitro study using a non-destructive method. minerva stomatol 2009;58(3):61-72. 12. 12-groten ms, girthofer s, probster l. marginal fit consistency of copy-milled allceramic crowns during fabrication by light and scanning electron microscopic analysis in vitro. j oral rehabil 1997; 24: 871-81. 13. 13-boening kw, wolf bh, schmidt ae, kastner k, walter mh. clinical fit of procera all ceram crowns. j prosthet dent 2000; 84(4): 419-24. 14. 14-gassino g, baronemonfrin s, scanu m, spina g, preti g. marginal adaptation of fixed prosthodontics: a new in vitro 360-degree external examination procedure. int j prosthodont 2004; 17: 218-23 15. van der meer wj, andriessen fs, wismeijer d, ren y. application of intra-oral dental scanners in the digital workflow of implantology. j plos one 2012; 7(8) : e43312. 16. 16ender a, mehl a. accuracy of complete-arch dental impressions: a new method of measuring trueness and precision. j prosthetic dentistry 2013; 109: 121-8. 17. schaefer o, decker m, wittstock f, kuepper h, guentsch a. policlinic of prosthetic dentistry and material science. j dentistry 2014; 42: 677-83 18. patzelt sbm, emmanouilidi a, stampf s, strub jr, att w. accuracy of full-arch scans using intraoral scanners. j clinical oral investigations 2014; 18: 1687-94. thaer.doc j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 129 immunohistochemical expression of p53, as a marker of apoptosis in hodgkin’s and non hodgkin’s lymphoma of the head and neck region thaer k. ali, b.d.s., m.sc. (1) bashar h. abdulla, b.d.s., m.sc., ph.d. (2) khitam r. kadhim, m.b.ch.b., f.i.c.m.s. (3) abstarct background: malignant lymphomas represent about 5% of all malignancy of the head and neck region which can involve lymph nodes as well as soft tissue and bone of the maxillofacial region. apoptosis is considered a vital component of various processes including normal cell turnover, proper development and functioning of the immune system. inappropriate apoptosis is a factor in many human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer. expression of p53 proteins in hodgkin׳s and non hodgkin׳s lymphomas suggested that it can help in monitoring of patients and the markers may aid in controlling the progression of lymphoma and detect the degree of aggressiveness of the disease to give suitable treatment and management of patients. material and methods: sixty seven formalin-fixed, paraffin-embedded tissue, histopathologically diagnosed lymphoma blocks (head and neck lesions) as (24) hodgkin’s lymphoma and (43) non hodgkin’s lymphoma. immunohistochemical (ihc) technique was used for the evaluation of p53 monoclonal antibodies expression and correlated with the clinicopathological parameters. results: the mean of expression of p53 in relation to tumor grades was different as it had a value of (51.2±13.5) in low grade tumors, (55.7±20) in the intermediate grade tumor and (45±17.6) in high grade tumors; consequently, this difference did not reached the level of statistical significance p(anova) >0.05. conclusions: this study had shown that there was no significant correlation between the mean of expression of p53 in hl and nhl. key words: p53, apoptosis, hodgkin’s lymphoma, non hodgkin’s lymphoma. (j bagh coll dentistry 2014; 26(4):129132). الخالصھ موت الخالیا . من كل االمراض لمنطقة الرأس والعنق والتي یمكن ان تنطوي على العقد اللمفاویھ وكذلك االنسجھ الرخوه ومنطقة الوجھ والفكین% 5اللمفوما الخبیثھ تمثل حوالي :خلفیھ اما (موت الخالیا المبرمج الغیر مناسب . لخالیا والتطور المناسب وعمل الجھاز المناعيالمبرمج یعتبر عنصر حیوي لكثیر من العملیات المتنوعھ من ضمنھا عملیة التحول الطبیعي ل وعدة أنواع من ھو عامل في العدید من الحاالت البشریھ من ضمنھا أمراض التحلل العصبي، التلف نتیجھ فقر الدم الموضعي ،حاالت أضطراب المناعھ الذاتیھ) بصوره قلیلھ أو كثیره p53في ھودجكن والھودجكن لمفوما مستعملین طریقة النسیجي المناعي الكیمیائي ، اقترحت بأن الدراسات المناعیھ النسیجیھ الكیمیائیھ لعامل p53بیر عن بروتینالتع. السرطان فوما ونتحقق من درجة عدوانیة المرض العطاء العالج وظھوره في أورام االنسجھ یمكن أن یساعد في رصد المرضى والدراسات وكذلك المعلمات ممكن أن تساعد في ضبط تقدم اللم .المالئم وأدارة المرض اربعھ وعشرون حالة ھودجكن لمفوما وثالثھ وأربعون .من منطقة الراس والعنق مع البرافین، مشخصھ نسیجیاسبعھ وستین نسیج مثبت بالفورمالین ومطموره بش: المواد والطرق . كمضاد احادي النسل وربط ذلك مع المعاییر العیادیھ المرضیھ p53كیمیائیھ النسیجھ قد استعملت لتقییم تعبیر تقنیة المناعھ ال. الھوجكن لمفوما ي الورم ف 17.6±45في الورم متوسط الدرجھ و 20±55.7في الورم واطيء الدرجھ و 13.5±51.2وعالقتھ بدرجھ الورم كانت مختلفھ كما كانت لھا قیمھ p53معدل تعبیر: النتائج . p>0.05وكنتیجة االختالف لم یصل الى المستوى االحصائي المھم : عالي الدرجھ .في ھودجكن والھوجكن p53ھذه الدراسھ قد أظھرت بأنھ لم تكن ھناك عالقھ مھمھ بین معدل تعبیر : االستنتاج introduction malignant lymphomas can be divided into two major categories: hl which is almost exclusively a nodal disease and nhl. lymphomas presenting in extranodal sites of the head and neck and these sites includes oral cavity, oropharynx, nasopharynx, paranasal sinuses, and larynx, which are mainly nhls of low or high grade, it may also presents as cervical lymphadenopathy which is the most common head and neck presentation for both diseases. the process of programmed cell death, or apoptosis, is generally characterized by distinct morphological characteristics and energydependent biochemical mechanisms; also apoptosis is considered a vital component of vari (1) ph.d. student. department of oral diagnosis, college of dentistry, university of baghdad. (2) professor. department of oral diagnosis, college of dentistry, university of baghdad. (3) assistant professor. department of pathology and forensic medicine, college of medicine, university of baghdad. ous processes including normal cell turnover, proper development and functioning of the immune system, hormone-dependent atrophy, embryonic development and chemical-induced cell death. inappropriate apoptosis is a factor in many human conditions including neurodegenerative diseases, ischemic damage, autoimmune disorders and many types of cancer. the capacity of p53 for multiple biological functions can be attributed to its ability to act as a sequencespecific transcription factor to regulate expression of over one hundred different targets, and thus to modulate various cellular processes including apoptosis, cell cycle arrest and dna repair (1). expression of p53 proteins in hodgkin׳s lymphomas and non hodgkin׳s lymphoma patients using immunohistochemistry (2), suggested that these studies can help in monitoring of patients at risk, and the markers j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 130 may aid in controlling the progression of lymphoma and detect the degree of aggressiveness of the disease to give suitable treatment and management of patients (3). materials and methods this study included (67) formalin-fixed, paraffin-embedded histopathologically diagnosed lymphoma blocks (head and neck lesions). the diagnosis of each case was confirmed by the histological examination of the hematoxylin and eosin staining (h&e), examined and confirmed by two experienced pathologists. demographic and clinical data provided by the surgeon were obtained from the case sheets presented with the tumor specimens, including information concerning patient's age, gender, clinical presentation, site of tumor. histological classification was determined according to the international working formula (iwf) criteria, where all cases classified into hodgkin's lymphoma (24 cases) and non-hodgkin's lymphoma (43cases). positive tissue control included in this study was: breast carcinoma .the diagnosis of each case was confirmed by the use of cd15, cd30 for hl and cd20, bcl2 for nhl. sections of 5µm thickness were mounted on glass slides for routine (h&e), from each block of the studied sample and the control group for histopathological re-examination. other 10 sections of 4µm thickness were mounted on positively charged microscopic slides to obtain a greater tissue adherence. all of these collected specimens were subjected to immunohistochemical staining using different and specific monoclonal antibodies included in the study. abcam, expose mouse and rabbit specific hrp/dap detection ihc kit, antigen retrieval solutions: citrate buffer ph 6.0., anti-p53 mouse monoclonal[pab] to p53, 1:250-1:500, overnight, abcam, england. immunohistochemical staining is accomplished with antibodies that recognize the target protein. only the number of cells showing nuclear expression of p53 was quantified by counting at least 1000 cells in five representative fields at 40x objective in each case, the intensity of staining was not considered for evaluation. all fine to coarse brown granular nuclear precipitate were regarded as positive. the percentage of p53 positively stained cells was semi-quantitatively determined as follows (-) negative ≤5%, (+) low 6-25%, (++) moderate 26-50% and (+++) high 51-100% (2,3). statistical analysis an expert statistical advice was sought for. statistical analyses which were done using spss version 21 computer software (statistical package for social sciences) in association with microsoft excel 2010. results there was no statistical significant difference in the mean of expression of p53 between hl (fig 1) and nhl (fig 2) as shown in table 1 the mean of expression of p53 in relation to tumor grades was different as it had a value of (51.2±13.5) in low grade tumors, (55.7±20) in the intermediate grade tumor and (45±17.6) in high grade tumors; consequently, this difference did not reached the level of statistical significance p(anova) >0.05as shown in table 2: the mean of expression of p53 in nodular sclerosing hl (48.1±18.4) was higher than that of mixed cellularity (46.3±26.4). obviously there was a difference in the mean of expression but it did not revealed any statistical significance (table 3). table 1: difference in the mean of expression of p53 between hl and nhl nhl compared to hl p (t-test) hl nhl p53 0.6[ns] range (18 81) (13 88) mean 47.3 49.8 sd 20.1 18.4 se 4.1 2.8 n 24 43 table 2: difference in the mean of expression of p53 in relation to the tumor grades tumor grade p (anova) trend low grade intermediate grade high grade p53 0.46[ns] range 27 65 24 85 13 88 mean 51.2 55.7 45 sd 13.5 20 17.6 se 5.53 5.01 3.83 n 6 16 21 r=-0.254 p=0.1[ns] j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 131 table 3: difference in the mean of expression of p53 in relation to hl subtypes morphology nodular sclerosing mixed cellularity p p53 0.85[ns] range (20 80) (18 81) mean 48.1 46.3 sd 18.4 26.4 se 4.59 9.98 n 16 7 fig. 1: hl mixed cellularity p53 brown staining of nucleus of tumor cells (x 400) fig. 2: nhl dlbc p53 brown staining of nucleus of tumor cells. (x400) discussion in non-hodgkin's lymphomas, apoptosis plays an important role together with proliferative activity in counter-balancing tumor volume (1,4). there has been accumulating evidence that hodgkin and reed-sternberg (h/rs) cells, the presumed neoplastic-cell population in hl are characterized by a profound disturbance of the cell cycle and apoptosis regulation (5). the mean of expression of p53was different among the tumor grade with increasing toward intermediate grade but the difference did not reach the level of statistical difference; a result that merely the same what mishra and crasta (6) conducted to the expression of apoptotic markers is higher in highgrade oscs, which also have a higher proliferative activity compared with those in lowgrade oscs a conclusion that of ozer et al. (7). there is growing evidence that p53 also exerts its effects on multiple aspects of tumor formation, including suppression of metastasis and, inhibition of new blood vessel development (angiogenesis) (8). this study had shown that there j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 132 is a difference in mean of expression of p53 in hl47.3±20.1 which lower as compared to the mean of its expression in nhl 49.8± 18.4 and even when this difference did not reached to level of statistical significance but it could explain the difference in behavior between the more aggressive tumor (nhl) as compared to (hl). references 1. alaswad ea, abdul-mohymen n, ghazi hf. expression of ki67and p53 proteins in hodgkin׳s lymphomas and non hodgkin׳s lymphoma patients using immunohistochemistry. iraqi cancer and medical genetics 2011; 4: 37-42.. 2. alves fa, pires fr, de almeida op, lopes ma, kowalski lp. pcna, ki-67 and p53 expressions in submandibular salivary gland tumors. int j oral maxillofac surg 2004; 10: 593-7. 3. lee jj, kuo my, cheng sj, chaing cp, jeng jh, chang hh, kuo ys, lan wh, kok sh. higher expressions of p53 and proliferating cell nuclear antigen (pcna) in atrophic oral lichen planus and patients with areca quid chewing. oral surg oral med oral pathol oral radiol endod 2005; 99: 471-8. 4. takano y, saegusa m, ikenaga m, okayasu i, apoptosis and proliferative activity of non-hodgkin's lymphomas: comparison with expression of bcl-2, p53 and c-myc proteins. pathol int 1997; 47(2-3): 90-4. 5. prasad rk, koduru k r, veena v, geetha m , shefali s, myron s, jonathan k, john db. correlation between mutation in p53, p53 expression, cytogeneticshistologic type, and survival in patients with b-cell non-hodgkin’s lymphoma. blood 1997; 90(10): 4078-91. 6. mishra sk, crasta ja. an immunohistochemical comparison of p53 and bcl-2 as apoptotic and mib1 as proliferative markers in low-grade and high-grade ovarian serous carcinomas. int j gynecol cancer 2010; 20(4): 537-41. 7. ozer h, yenicesu g, arici s, cetin m, tuncer e, cetin a. immunohistochemistry with apoptoticantiapoptotic proteins (p53, p21, bax, bcl-2), c-kit, telomerase, and metallothionein as a diagnostic aid in benign, borderline, and malignant serous and mucinous ovarian tumors. diagnostic pathol 2012; 7: 124. 8. teodoro jg. inhibition of tumor angiogenesis by p53: a new role for the guardian of the genome. j mol med (berl) 2007; 85 (11): 1175-86. 9. vu th, werb z. matrix metalloproteinases: effectors of development and normal physiology. genes development 2000; 14: 2123-33. luma.doc j bagh college dentistry vol. 27(2), june 2015 flattening of the oral diagnosis 66 flattening of the posterior slope of the articular eminence of completely edentulous patients compared to patients with maintained occlusion in relation to age using computed tomography luma abdul-rada abdul-nabi, b.d.s., d.d.s. (1) lamia h. al-nakib, b.d.s., m.sc. (2) abstract background: the posterior slope of the articular eminence of completely edentulous patients compared to patients with maintained occlusion shows significant flattening. this study aimed to correlate between the flattening of the posterior slope of the articular eminence, with dental status, age, genders, on both sides using computed tomography. materials and methods: the sample of the present study was a total of 117 iraqi subjects, who admitted to the maxillofacial department at al-sadr teaching hospital in al-najaf city. the examination was performed on ct scanner; the eminence inclination was measured in two methods using sagittal section. results: clinically, the inclination of articular eminence was higher in edentulous subjects than in dentate subjects. while no statistically significant differences were found in the eminence inclination between the age groups. no statistically significant differences were found between the right and left side measurements or between female and male subjects. conclusion: there were no statistically significant differences in eminence inclination according to sex, age and between right and left side. the flattening of the articular eminence was significantly higher in completely edentulous patients than in patients with maintained occlusion. keyword: elderly, complete edentulousness, condyle of the mandible, articular eminence, condylar inclination. (j bagh coll dentistry 2015; 27(2):66-71). introduction tmj is a complex articular system which is located between the mandible and the temporal bone (1). the osseus parts of tmj, in addition to other factors, exert important influence upon the magnitude of the lower jaw movement. particularly, the slope of the posterior wall of the articular eminence (2), which is that part of the temporal fossa over which the condyle-disk complex, slides during the various mandibular movements. the articular eminence inclination is defined as the angle formed by the articular eminence and the frankfort horizontal (fh) plane or any other horizontal plane, such as the occlusal or palatal plane.(3) flattening of the articular eminence might occur via disuse or lesser masticatory activity in edentulous patients and changes in the consistency of their diets seem to generate it. another possible cause can be observed such as partial edentulism, orthopedic aparotology and orthodontic strengths, angle’s class ii and iii malocclusions, over closure, the presence of tmj disorders. (4-14) alterations from erosion, osteophyte formation, anterior disc displacement with reduction or anterior disc displacement without reduction. (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. these transformations appear to represent an adaptation of the condyle, articular disc and the articular eminence to changes in loading. (15) some authors have found a connection between the loss of teeth and the articular eminence inclination (16,17). such changes are significant when individuals have been edentulous for periods lasting more than three years (18). there are several methods to determine the angulation of the posterior slope of the articular eminence. some authors took anthropological measurements carried out on dry skulls, while others utilized medical imaging techniques (conventional radiography and tomography, mri and ct (19). the application of conventional ct in imaging the tmj has been most significant for the evaluation of hard tissue or bony changes of the joint. multidetector ct (mdct) demonstrated the highest accuracy, with 93% sensitivity and 100% specificity (20). materials and methods the study sample consists of 117 iraqi subjects (60 male and 57 female) with age ranged from (20-80) years, attending to the maxillofacial department at al-sadr teaching hospital in alnajaf city. the sample was divided into three groups: 1group i: 2030 years with maintained occlusion (males: 20, females: 21) j bagh college dentistry vol. 27(2), june 2015 flattening of the oral diagnosis 67 2group ii: over 50 years with maintained occlusion (males: 19, females: 19) 3group iii: edentulous subjects over 50 years at least for three years (males: 21, females: 17) the three groups were compared according to dentalstatus, age, sex and side. patients with degenerative disorders of tmj like interal derangement, arthritis, bruxism and history of orthodontic treatment were excluded from the study. the eminence inclination was measured in two methods using sagittal section which were: 1-best-fit line method:the best-fit plane of the articular eminence posterior surface was drown, in sagittal section. frankfort horizontal plane was drawn. the angle that formed between two planes in sagittal section was measured (eminence inclination), (figure 1). this method was done for the right &left sides. figure 1: angle between two planes in sagittal section represented the eminence inclination. 2top-roof line method which is the angle between the plane passing through the points (the deepest point of articular eminence & the highest point of the fossa) and frankfort horizontal plane, in sagittal section. the plane which joined the two points was drawn (highest point of the mandibular fossa & the deepest point of the articular eminence). frankfort horizontal plane was drown. angle that formed between two planes in sagittal section (which represent the articular eminence inclination), was measured (figure 2). this was done for right &left sides. figure 2: angle between two planes in sagittal section (which represent the articular eminence inclination). statistical analyses were done using spss version 21 frequency distribution for selected variables was done first. the primary outcome quantitative variable (slope measurement) for the present study was shown to be normally distributed. such quantitative variables are described by mean, sd, se. the independent samples t-test was used to assess the statistical significance of difference in mean between 2 groups. anova trend model was used to test the statistical significance of difference in mean of a quantitative normally distributed variable with age group. results the mean of psaei angle was significantly higher among dentate group compared to edentulous group. the difference in mean (-6.6 o , 14.5 o ). while the effect of being edentulous was strong (cohen's d = -1.73, -2.14). table 1 and figure 3. j bagh college dentistry vol. 27(2), june 2015 flattening of the oral diagnosis 68 table 1: the differences in mean measurement of psaei angle between dentate and edentulous group. being edentulous for 50+ years only diff. in mean cohen's d p dentate edentulous mean of left and right side (top roof line method) range (36.1 to 46) (24 to 42) -6.6 -1.73 <0.001 mean 41 34.4 sd 2.8 4.7 se 0.63 1.15 n 19 17 mean of left and right side (best fit line method) range (52 to 72.5) (32 to 61.5) -14.5 -2.14 <0.001 mean 62 47.5 sd 6.1 7.5 se 1.39 1.83 n 19 17 0 5 10 15 20 25 30 35 40 45 50 being edentulous (for 50+ years only) em in en ce in cli na tio n an gl e (b es t f it lin e m et ho d) -m ea n le ft an d rig ht s id e dentate edentulous figure 3: dot diagram with error bars showing the mean measurements of psaei angle(toproof method) by age and dentition status(with its 95%ci). the eminence inclination value of males were higher than those of females in both dentate and edentulous groups for right and left sides and by two way of measurements; however, these differences were not statistically significant (p> 0.05).comparing the differences between the mean angle values of right and left sides of the three groups, it can be seen that the values found in the group of elderly patients with maintained occlusion were much closer to the values of the young group. no significant difference was measured between the right and left side in these groups (p> 0.05). table 2 j bagh college dentistry vol. 27(2), june 2015 flattening of the oral diagnosis 69 table 2: age difference in mean measurement of psaei angle (dentate only) age group (years) p group i<=30 group ii 50-69 group iii 70+ psaei angle (top-roof method)-mean left and right side range (38 to 51.3) (36.1 to 47) (38 to 45.5) 0.18[ns] mean 42.7 41.3 4o.7 sd 3.1 2.9 2.3 se 0.49 0.56 0.68 n 41 27 11 psaei angle (best-fit-line) mean left and right side range (57 to 72.2) (52 to 69) (54 to 70) 0.84[ns] mean 63.8 60.9 60 sd 4.1 5.1 5 se 0.63 0.98 1.5 n 41 27 11 the mean of left and right side was higher in group i compare to group ii, difference in mean was (-5.5 o ,-2.9 o ). the effect was strong (cohen's d = -0.85, -0.78) table 3. there was no significant difference between right and left side in dentate and edentulous group and by two ways of measurements (figure 4). table 3: age difference in mean measurement of psaei angleedentulous group age group( years ) diff. in mean cohen's d p group 1 (50-69) group 2 70+ mean of left and right side (best-fit-line) range (41 to 61.5) (32 to 57.5) -5.5 -0.85 0.013 mean 51 45.5 sd 5.5 7.4 se 1.24 1.75 n 20 18 mean of left and right side (top-roof-method ) range (28.5 to 42) (24 to 39.5) -2.9 -0.78 0.021 mean 35.7 32.8 sd 3.1 4.3 se 0.7 1 n 20 18 -20 -15 -10 -5 0 5 10 15 20 25 eminence inclination angle (best fit line method)-difference between left and right sideeminence inclination angle (top-roof method)-difference between left and right side figure 4: dot diagram psaei angle-difference between right and left side [ discussion best-fit-line method top-roof method j bagh college dentistry vol. 27(2), june 2015 flattening of the oral diagnosis 70 from analysis shown in table 1 & figure 1 there was significantly increase in reduction in psaei in edentulous group compare to dentate group. flattness of articular eminence directly propotion with loss of teeth & this effect was strong as the cohen's > 0.8. whats found is in agreement with other studies who reported the same relationships (11,14,15, 21,22).some authors concluded thata reduction in the height of the fossa was observed in individuals who had remained edentulous for three years compared to dentate subjects.(20,17,4,9,10) this study is disagreed with other previous investigations that show the loss of teeth has no effect upon the articular eminence inclination (2,23). in the current study showed that gender had no significant effect on psaei, however, the mean of eminence inclination value in males were higher than in females these marginal differences were not statistically significant. found that there were no differences in eminence inclination by gender(15). there are few studies in the literature that found a difference in eminence inclination according to gender.(2,24,25,26)these differences may be attributed to the sample sizes used in these studies. from table2,the mean of left and right side of psaei was found to be highest in the group i (42.7°,63.8°), followed by group ii (41.3°,60.9°), and lowest in the group iii (40.7° , 60°).but the differences in mean not reach significant effect related to measurements of articular eminence. so the age has no or mild effect on articular eminence. similar findings were reported by dilhan (26). even though less adaptive capacity is recognized during an individual’s advanced age, articular remodelling in such people has been proved to be constant, especially in edentulates having total prosthesis (9). this study is in disagreement with previous studies by kurita (27) and sülün (28) who reported that morphological changes may occur in the eminence structure with advanced age and this results in the flattening of the eminence in the long term. in the present study, it was found that there was a significant difference between the mean of right and left sides of subjects in group i and group ii,(35.7°, 51°) (31.1°,45.5°) respectively, differences in mean (-2.9°,-5.5°) this mean increase in reduction with age & the effect of age was moderate to strong on psaei (cohen's -0.78 ,-0.85)(table 3) it was noted that eminence inclination is dependent not only upon age but also on dental status in edentulous subjects, so it would be wrong to assess eminence inclination according to age only in edentulous subjects. this is in agreement with other sciences (15) reported the flattening of the articular eminence could be correlated with age; however, the rate of deformation is significantly higher in completely edentulous patients than in patients with a maintained occlusion. similar findings were reported by previous studies (28-30). ballesteros et al (1) concluded that there was association between dental state and age as being determinant factors in reducing mandibular fossa depth. no significant differences were observed between left and right side. this is in agreement with kinga et al (15) reported no significant difference was measured between the two sides. zabarovil (2) concluded that the asymmetry between the left and right joint was almost a rule, and the difference reaches up to 30°. in this study, figure 2 showed no differences between the two methods of measurements, both angles represent the articular eminence inclination, the (best fit line–frankfurt horizontal plane) focuses primarily on the posterior surface of the eminence, whereas the latter method (fossa roof–eminence top, frankfurt horizontal plane) focuses on the location of the eminence crest relative to the fossa roof. it seems that ‘‘best fit line’’ method is more accurate due to the fact that the posterior slope of the articular-eminence is easy to observe (and measure the inclination), while the location of the eminence crest and the fossa roof are more subjected to individual determination (possibility of mistake) (3). references 1. ballesteros le. ramirez lm, muñoz g. mandibular fossa depth variations: relation to age and dental state. int j morphol 2011; 29(4): 1189-94. 2. zabarovic d, jerolimov v, carek v, vojvodic d, zabarovic k, bukovic d jr. the effect of tooth loss on the tm-joint articular eminence inclination. coll antropol 2000; (suppl 1): 37–42. 3. katsavrias eg. changes in articular eminence inclination during the craniofacial growth period. angle orthod 2002; 72(3): 258–64. 4. oberg t, carlsson ge, fajers cm. the temporomandibular joint. a morphologic study on a human autopsy material. acta odontol scand 1971; 29(3): 349-84. 5. carlsson ge, oberg t. remodelling of the temporomandibular joints. oral sci rev 1974; 6(0): 53-86. 6. granados j. the influence of the loss of teeth and attrition on the articular eminence. j prosthetic dent 1979; 42: 78–85. 7. floridi a, matson e. contribution to the study of variation of the depth of the human jaw cavity, face of the total absence of the permanent teeth. rev odontusp1987; 1:42-5. 8. pirttiniemi p, kantomaa t, rönning o. relation of the glenoid fossa to craniofacial morphology, studied on j bagh college dentistry vol. 27(2), june 2015 flattening of the oral diagnosis 71 dry human skulls. acta odontol scand 1990; 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25:174–9. 22. yamada k, tsuruta a, hanada k, hayashi t. morphology of the articular eminence in temporomandibular joints and condylar bone change. j oral rehabil 2004; 31: 438–44. 23. kranjčić j, vojvodić d, žabarović d, vodanović m, komar d, mehulić k. differences in articulareminence inclination between medieval & contemporary human populations. arch oral biol 2012; 57(8):1147-52. 24. zivko-babic´ j, panduric´ j, jerolimov v, mioc m, pizeta l,jakovac m. bite force in subjects with complete dentition. coll antropol 2002; 26: 293–302. 25. ejima k, schulze d, stippig a, matsumoto k, rottke d, honda k. relationship between the thickness of the roof of glenoid fossa, condyle morphology and remaining teeth in asymptomatic european patients based on cone beam ct data sets. dentomaxillofacial radiology 2013; 42(3): 90929410. 26. elgüy d, elgüy m, figekçiollu e, dölekollu s, ersan n. articular eminence inclination, height, and condyle morphology on cone beam computed. turkey hindawi publishing corporation the scientific world j 2014. 27. kurita h, ohtsuka a, kobayashi h, kurashina k. flattening of the articular eminence correlates with progressive internal derangement of the temporomandibular joint. dentomaxillofac. radiol 2000; 29(5): 277-9. 28. kurita h, ohtsuka a., kobayashi h. & kurashina k. flattening of the articular eminence correlates with progressive internal derangement of the temporomandibular joint. dentomaxillofac radiol 2000; 29(5): 277-9. 29. touré g, duboucher c. & vacher c. anatomical modifications of the temporomandibular joint during ageing. surg radiol anat 2005; 27(1): 51-5. 30. meng fw, hu kj, zhou sx, ning wd, yang xc, liu ck. the value of multislice helical ct in the morphological study of temporomandibular joint. j pract radiol 2006; 22: 1308-11. maha f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of oral and maxillofacial surgery and periodontics 96 assessment of transforming growth factor beta one (tgfβ1) immunohistochemical (ihc) expression profile in the gingival tissue of patients with different forms of periodontal diseases basma f. ali, b.d.s. (1) maha sh. al-rubaie, b.d.s., m.sc. (2) abstract background: this study evaluate the immunohistochemical expression profile of transforming growth factor beta-1 in inflamed gingival tissue of patients with gingivitis and chronic periodontitis compared to healthy subjects and, determine the correlation between this cytokine and the clinical periodontal parameters, intensity of inflammation and chronic periodontitis severity. materials and methods: gingival tissue specimens were taken from 23 chronic periodontitis patients, 20 gingivitis patients and 20 periodontally healthy subjects. the periodontal status was evaluated by dichotomous measurements of the clinical periodontal parameters (pli, gi, bop, ppd, cal). the gingival specimens were fixed immediately in 10% formalin and processed routinely into paraffin blocks for further immunohistochemical analysis. results: a highly significant statistical difference was observed between the study groups regarding the pli ,gi ,the percentage of bleeding on probing sites and the intensity of inflammation .tgf-β1 expression profile statistical analysis showed a high statistical significant difference among the study groups , a highly significant statistical difference was found between the ppd scores while a significant statistical difference was revealed among the cal scores when the expression profile of tgf-β1 was compared.tgf-β1 was positively correlated with the clinical periodontal parameters (pli, gi, and bop) as well as with the intensity of inflammation in the three study groups. in chronic periodontitis group a highly significant positive linear correlation between the ppd and cal with the tgf-β1 expression profile. conclusions: tgf-β1 expression profile showed variations as the destructive character of the periodontal disease changed. therefore, it could be proposed that tgf-β1 might contribute both to inflammatory regulation and remodeling events during periodontal disease. key words: transforming growth factor beta-1, periodontal diseases, gingival tissues. (j bagh coll dentistry 2013; 25(special issue 1):96-101). مرض النساغ المزمن ومقارنتھم ,للثة الھدف من ھذه الدراسة ھو تقییم نمط التعبیر لعامل النمو المحول بیتا في االنسجة اللثویة الملتھبة للمرضى الذین یعانون من التھاب ا:الخالصة عینة من مرضى النساغ 23تم اخذ .شدة التھاب اللثة وشدة مرض النساغ المزمن,معلمات اللثة السریریة معباالصحاء عن طریق التحلیل المناعي واختبار العالقة بین ھذا السیتوكین معامل الصفیحة (عینة من االشخاص ذوي االنسجة اللثویة السلیمة وجرى تقییم حالة اللثة عن طریق قیاس المعلمات اللثویة 20عینة من مرضى التھاب اللثة و 20المزمن و فورمالین تحضیرا لمعالجتھا بشكل % 10تم تثبیت العینات اللثویة على الفور في).عمق الجیب اللثوي ومستوى االنسجة الرابطة,النزف عند التسمیر,معامل التھاب اللثة,الجرثومیة جموعات الداخلة في الدراسة فیما یخص معامل الصفیحة في نتائج البحث لوحظ وجود فروقات احصائیة عالیة بین الم.روتیني وطمرھا بشمع البارافین الغراض التحلیل المناعي اظھرت النتائج االحصائیة لنمط تعبیر عامل النمو المحول بیتا وجود فروقات عالیة ضمن المجموعات الداخلة في .النزف عند التسمیروشدة االلتھاب,معامل التھاب اللثة,الجرثومیة ارتبط نمط تعبیر عامل .واالنسجة الرابطة عندما تمت مقارنة نمط تعبیر عامل النمو المحول بیتاستویات المختلفة لعمق الجیب اللثوي تم ایجاد فروقات احصائیة عالیة بین الم.الدراسة االنسجة الرابطة مع تعبیر عامل وي ومستوىالنمو المحول ایجابیا مع جمیع المعلمات اللثویة السریریة ومع شدة االلتھاب وتم ایجاد عالقة خطیة ایجابیة بین كل من عمق الجیب اللث .االنسجة اللثویةاستنتاجات ھذه الدراسة تقترح ان التغییرات في عامل النمو المحول بیتا یمكن ان یساھم في كل من تنظیم االلتھابات وعملیة اعادة بناء .النمو المحول بیتا introduction transforming growth factor beta-1 is one of the key cytokines with pleiotrophic properties that has both pro-inflammatory and anti-inflammatory features in regulation of the inflammatory infiltrate. this cytokine is a multifunctional cytokine that is involved in angiogenesis,immune suppression,extra cellular matrix synthesis ,apoptosis and cell growth inhibition and it is pro-inflammatory, since it is chemoattractant for neutrophils, monocytes, mast cells and lymphocytes and also causes the release of proinflammatory cytokines, such as interleukine-1 (il-1), interleukine-6 (il-6) and tumor necrosis factor-α (tnf-α), by these cells, anti-inflammato (1)m.sc. student. department of periodontics. college of dentistry. university of baghdad. (2)assistant professor. department of periodontics. college of dentistry. university of baghdad. ry properties of this cytokine include suppression of cell-mediated as well as humoral immune response (1, 2). the above features of tgf-β1 make it an interesting protein to monitor in the pathogenesis of periodontal disease. limited knowledge on the role of tgf-β1 in various periodontal disease types and particularly in advanced periodontitis forms warranted the conduction of this study in order to investigate tgf-β1 expression profile in tissue sections of subjects with healthy periodontium as a control group and patients with gingivitis and chronic periodontitis as study groups and test whether tgf-β1expression profile is correlated with the clinical periodontal parameters, intensity of microscopic inflammation and the severity of the periodontal diseases. j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of oral and maxillofacial surgery and periodontics 97 materials and methods patients and biopsies a total of 63 subjects (38 male, 25 female) attending the outpatient clinic at the department of periodontics in the teaching hospital of dentistry collegebaghdad / iraq, al khadhimya specialized dental centre as well as patients from private practices were recruited for the study. exclusion criteria included the presence of less than 20 natural teeth, pregnancy, non smoker, any systemic condition that could affect the host’s periodontal status or that would require antibiotics for monitoring or treatment procedures (e.g. heart conditions and joint replacements); use of antibiotics and/or anti-inflammatory drugs within the last 3 months; and professional cleaning or periodontal treatment within the last 6 months.the periodontal status was evaluated by dichtomous measurements of the following clinical periodontal parameters (pli, gi, bop, ppd, cal),t he first measurements were at the initial periodontal examination and the second measurements were recorded before tissue sampling at the time of periodontal surgery. measurements were performed at four sites per tooth for whole mouth excluding the 3rd molar. chronic periodontitis group was firstly subdivided intotwo scores according to the ppd which are: score (1): includes the examined sites with ppd range of 5-6 mm. score (2): includes the examined sites with ppd range of ≥ 7mm. then secondly into 3 scores according to measured cal for better estimation of the disease severity: score (1): includes the sites with cal range of 3-4 mm. score (2): includes the sites with cal range of 5-6 mm. score (3): includes the sites with cal ≥ 7 mm. all the patients underwent the 1st phase of periodontal therapy. based on the recorded gingival index (gi), probing pocket depth (ppd), clinical attachment level (cal) and radiographic evidence of bone loss; subjects were categorized into three groups: • group i (healthy) consisted of 20 subjects /age range (25-40) years with clinically healthy periodontium, ppd ≤ 3 mm and cal = 0. • group ii (gingivitis) consisted of 20 subjects/ age range (25-40) years who showed clinical signs of gingival inflammation, gingival enlargement and false pocket formation, ppd ≤ 3 mm and had no attachment loss (cal = 0) or radiographic bone loss. • group iii (chronic periodontitis) consisted of 23 subjects/ age range (30-50) years with at least four sites with a ppd ≥5mm and cal > 3 mm with radiographic evidence of bone loss. tissue sampling each patient underwent periodontal surgery, independently of this study, as a part of their routine periodontal treatment .the chronic periodontitis patients were arranged for fullthickness mucoperiosteal flap/debridement, the gingivitis patients with gingival enlargement were arranged for gingivectomy procedure while the healthy subjects underwent crown lengthening procedure or tooth extraction for orthodontic indication or extraction of impacted 3rd molar according to the designated treatment plan. informed consent was obtained from the patients to collect, preserve and analyzes the gingival tissues for this study. biopsies were obtained from the suitable sites at the time of surgeries. tissue preparation and staining all samples and positive controls were presumably fixed in 10% formalin, and processed routinely into paraffin blocks. from each paraffin embedded tissue block (samples and controls); serial sections were cut as follows: sections of 4μm thickness were mounted on normal glass slides, stained with hematoxylin and eosin (hand e), and histopathologically re-evaluated, the intensity of inflammation assessed according to farhad et al (3) and then photographed ,two other 4μm thick sections for each case were cut and mounted on positively charged slides (fisher scientific and eschosuperfrost plus, usa) for immunohistochemical staining with monoclonal antibodies.negative and positivetissue controls were included into each immunohistochemical run (according to the manufacturer).for transforming growth factor beta (tgf-β) monoclonal antibody, two tissue blocks of human breast cancer were used. immunohistochemical staining five micrometer thick sections were cut andmounted on (biocare, usa) positively charged slides, then de-paraffinized and rehydrated. for immunohistochemical staining by tgf-β (us biological) monoclonal antibodies; then the sections were immersed in 0.3%hydrogen peroxide (h2o2) to block the endogenous peroxidase activity, washed in phosphate-buffered saline (pbs), and then incubated in 10% normal serum to block any non-specific binding of antibodies. the tissue sections were incubated with monoclonal mouse anti-human tgf-β (diluted 1:30) antibodies over night at 37 ºc. the bounded antibodies were detected by the j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of oral and maxillofacial surgery and periodontics 98 streptavidin-biotin complex method, after an immunoreaction, the sections were counterstained with hematoxylin. quantitative assessments evaluation of inflammation on h and e stained specimens according to the method proposed by farhad et al (3), quantitative assessment of the inflammatory cells was performed in 5 separate fields of each h and e stained specimen at 400x magnification of light microscope. the mean count of inflammatory cells for the 5 fields was determined, and severity of tissue inflammatory response was classified as follows figure (1): • grade 0: absence of inflammatory cells or presence of fewer than 5 cells. • grade 1 (mild reaction): presence of 5 to 25 cells. • grade 2 (moderate reaction): presence of 25 to 125 cells. • grade 3(severe reaction): presence of more than 125 cells. figure 1: top; photomicrograph showing healthy gingiva. middle; photomicrograph showing chronic gingivitis (moderate), bottom; photomicrograph showing chronic periodontitis (severe), 100 x (h and e). evaluation of immunohistochemistry results immunohistochemical signal specificity was demonstrated by the absence of immunostaining in the negative control slides and its presence in recommended positive controls. membranous / or membraneous and cytoplasmic staining pattern was considered positive for tgf-β1 immunostaining, according to the manufacturer’s data sheets and were studied by light microscope under 10x objective. in each tissue section five representative fields were selected for tgfβ1maps immune-staining evaluation. positively stained cells were counted in fields (0.03 mm2) determined by an ocular grid at 400x magnification. cells edging the upper and left grid lines were included, whereas cells edging the bottom and right lines were excluded from the counts. cells were counted within 5randomly chosen areas in the ct. cell density was calculated as cells/mm2 (4). in the context of this research (tgf-β expression) term would be used as a synonym for the (tgf-β1 expressing inflammatory cell density), figures (2 and 3). figure 2 and 3: chronic gingivitis with positive brown -staining of tgf-β1 in the inflammatory cells tgf-β1 ecd = 160 cells/mm2 (200 x) (left photo). right photo represents chronic periodontitis with positive brown staining of tgf-b1 in the inflammatory cells tgf-b1 ecd=130cells/mm2 statistical analysis data are calculated and entered into a computerized data base structure. statistical analysis was done using spss software. mean and sd, t-test, chi square, anova test, mannwhitney test, kruskal-wallis test and pearson correlation coefficient (r) were used. level of significance was 0.05. results a highly significant statistical difference was observed between the study groups regarding the pli, gi, the percentage of bleeding on probing sites, table (1) and the intensity of inflammation, table (2). tgf-β1 expression profile's statistical analysis showed a high statistical significant difference among the study groups, table (3). a highly significant statistical difference was found between the ppd scores with a significant statistical difference among the cal scores when j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of oral and maxillofacial surgery and periodontics 99 the expression profile of tgf-β1 was compared table (4). tgf-β1was positively correlated with the clinicalperiodontal parameters (pli, gi, and bop) as well as with the intensity of inflammation in the three study groups, table (5). in chronic periodontitis group a highly significant positive linear correlation was revealed between the ppd and cal with tgf-β1 expression profile, table (6), figures (4 and 5). discussion in the present study, tgf-β1ecd was evaluated in patients with different forms of periodontal disease and in healthy subjects. the results demonstrated significantly elevated tgfβ1ecd in patients with chronic periodontitis and gingivitis compared to healthy subjects (p<0.001). elevated levels of tgf-β1ecd in advanced periodontitis and gingivitis could suggest that this cytokine is one of the components that contribute to the extent of inflammatory response.tgfβ1exerts both anti-inflammatory and proinflammatory effects on host cells during the onset and progression of periodontal disease, it is a critical mediator in resolution of inflammation and indicates ongoing wound healing and chronic inflammation during host response (5,2), any or all of these tgf-β1 dependent mechanisms could contribute both to the initiation and regulation of inflammation and connective tissue destruction in periodontal diseases. the gingivitis group showed a higher significant tgf-b1ecd as compared to the control group this result is in line with other studies (6 -8). the presence of tgf-β1in the gingival overgrowth is attributed to (besides to its role as pro-inflammatory cytokine) its important profibrogenetic role, not onlyby inhibiting the synthesis of metalloproteinases, but also by stimulating synthesis of collagen in lamina propria (9)..tgf-β1 role in gingival overgrowth can be interpreted as the natural evolution of the periodontal lesion, inflammation preceding fibrosis, and tgf-β1 activity phase of this evolution: the initial pro-inflammatory cytokine (10), suggesting a key role in host response to immune challenge initiated by the presence of bacteria. subsequently, tgf-β1 over expression that we noticed could be a response to paracrine stimulation by other cytokines secreted by the pro-inflammatory cells causing excessive deposit of collagen by exceeding its physiological effect on healing (increasing the number of fibroblasts and increase their capacity for synthesis of collagen). the elevated tgf-β1ecd in periodontitis groups compared to gingivitis might indicate the counterbalancing role of tgf-β1in periodontal tissue breakdown by acting against exaggerated immune and inflammatory host response.tgfβ1might switch from proto anti-inflammatory role in order to regulate immune-inflammatory responses and limit tissue degradation with the progression of periodontal disease to a more destructive state as in periodontitis (4). results obtained from immunohistochemical reactions of the present study have shown a steady increase in tgf-β1 expression from normal gingiva to chronic periodontitis this is in agreement with other studies (4,11,12). a highly significant strong positive correlation was revealed between the pli and tgf-β1 expression, this is in accordance with others (11, 13), plaque with its components of bacteria and their products, in addition to directly recruiting and activating leukocytes at sites of infection, indirectly influence the inflammatory events through the induction of cytokines such as tgfβ1 (14). transforming growth factor beta 1 expression correlated to the gi in highly significant strong positive correlation and this is in agreement with gürkan et al. (11). in keeping with its dichotomous nature, recent evidence suggests that overproduction and/or activation of tgf-β1 contribute to persistent inflammation and that antagonists of tgf-beta delivered locally can break the cycle of leukocyte recruitment and fibrotic sequelae. on the other hand, systemic routing of tgf-beta can also inhibit inflammatory pathogenesis by multiple mechanisms as exemplified by systemic injections (15). the results showed the presence of positive significant correlation between the tgf-β1 ecd and bop. the findings of the study are in consistence with the results of gurkan (11). bop represents the earliest sign of the gingival inflammation (16) hence such an objective index is expected to be sensitive to the molecular changes that take place during the progression of the periodontal disease and correlates with quanititative and qualitative expression of the pro/anti-inflammatory cytokines.a significant positive correlation was established between the intensity of inflammation and tgf-β1expression profile, this is consistent with (6). our results confirm that increased gingival inflammation accompanying the progression of periodontal disease is associated with high levels of tgfβ1.a direct relation exists between the magnitudes of the inflammation process with the level of this cytokine (17). tgf-β1 has the ability to induct and potentiate the action of other inflammatory cytokine resulting in multiplying the magnitude of the j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of oral and maxillofacial surgery and periodontics 100 inflammatory condition, tgf-β in the presence of il-6 drives the differentiation of t helper 17 (th17) cells, which can promote further inflammation (18), tgf-β orchestrates the differentiation of both treg and th17 cells in a concentration-dependent manner (19), in addition, tgf-β in combination with il-4, promotes the differentiation of il-9and il-10-producing t cells, which lack suppressive function and also promote further tissue inflammation (20,21). regarding the severity of chronic periodontitis, statistical analysis showed a highly significant positive linear correlation between ppd and cal with the expression profile of tgf-β1 this in agreement with the findings of other studies (6,7,11,22). also a highly significant difference was found between ppd scores while cal scoresshowed a significant difference this is in agreement with skaleric et al (22). these results represent that in human periodontal disease tgfβ1 shows a concomitant elevation trend as the disease severity progresses. in other words, tgfβ1 expression profiles were higher in patient groups as there is little doubt that excessive and/or continuous production of this cytokine in inflamed periodontal tissues is responsible for the progress of periodontitis and periodontal tissue destruction (23). however, it remains unknown whether advanced periodontal destruction at sites of severe chronic periodontitis is due to insufficiently elevated anti-inflammatory cytokine levels. advances in periodontal treatment strategies showed that by antagonizing the activity of tgfbeta with neutralizing antibodies, a causal relationship between this cytokine, inflammation, and pathogenesis has been demonstrated. administration of anti-tgf-beta to sites of chronic destructive inflammation not only blocked leukocyte recruitment and activation, but also inhibited the subsequent destruction of bone and cartilage characteristics of such lesions (14,24,25). references 1. kritsy cp, lynch se. role of growth factors in cutaneous wound healing: a review. crit rev oral biol med 1993; 4: 729-60. 2. marek a, brodzicki j. tgf-β (transforming growth factor-b) in chronic inflammatory conditions-a new diagnostic and prognostic marker? med scimonit 2002; 8:145-51. 3. farhad ar, hasheminia s. histopathological evaluation of subcutaneous tissue response to three endodontic sealers in rats. j oral sci 2011; 53(1):1521(ivsl). 4. steinsvoll s, halstensen ts, schenck k. extensive expression of tgf-b1 in chronically-inflamed periodontal tissue. j clin periodontol 1999; 26: 366– 373. 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(ivsl). 20. dardalhon v, awasthi a. il-4 inhibits tgf-betainduced foxp3+ t cells and, together with tgf beta, generates il-9+ il-10+ foxp 3 (−) effector t cells. nat immunol 2008; 9: 1347–1355. 21. veldhoen m, uyttenhove c. transforming growth factor-beta 'reprograms' the differentiation of t helper 2 cells and promotes an interleukin 9-producing subset. nat immunol 2008; 9: 1341–1346.2. 22. skaleric u, kramar b, petelin m, pavlica z, wahl sm. changes in tgf-b1 levels in gingiva, crevicular fluid and serum associated with periodontal inflammation in humans and dogs. eur j oral sci 1997; 105: 136-42. (ivsl). 23. okada h, murakami s. cytokine expression in periodontal health and disease. crit rev oral biol med 1998; 9(3):248266. j bagh college dentistry vol. 25(special issue 1), june 2013 assessment of oral and maxillofacial surgery and periodontics 101 24. ruscetti f, varesio l, ochoa a, ortaldo j. pleiotropic effects of transforming growth factor-beta on cells of the immune system. ann n y aca sci 1993; 685:488500. 25. kaigler d, cirelli ja, giannobile wv. growth factor delivery for oral and periodontal tissue engineering. expert opin drug deliv 2006; 3(5): 647–662. table 1: the mean values of pli, gi and the percentages of sites with bop among the study groups c g cp p sig pli 0.514±0.271 1.699±0.330 1.467±0.570 <0.001 hs gi 0.435±0.338 1.536±0.370 1.343±0.451 <0.001 hs bop score 0 95.40% 75.40% 84.30% <0.001 hs score1 4.50% 24.50% 15.60% table 2: distribution of study groups according to different inflammation grades table 3: the mean ±sd of tgf-β1 expressing cell density (tgf-β1 ecd) in the study groups table 4: tgf-β1 ecd means of each ppd and cal score table 5: the correlation between pli, gi and bop of the study groups with tgf-β1 ecd table 6: the correlation between ppd and cal means with the tgf-β1 expression figure 4 and 5: scatter plots showing the linear correlation between ppd and cal with tgf-β1 expression. c g cp p sig. intensity of inflammation mild 45% 0 0 <0.001 hs moderate 55% 40% 17% severe 0 60% 83% control gingivitis chronic periodontitis *p-value sig tgf-β1 expressing inflammatory cells density(cell\mm2) mean 44 147.50 156.87 <0.001 hs ±sd 26.852 29.470 24.242 mean cell density pvalue sig. ppd score1 127.69 0.003 hs score2 162.33 cal score1 137.5 0.020 s score2 150.9 score3 191 tgf-β1 ecd clinical parameters control gingivitis chronic periodontitis r p-value r p-value r p-value pli 0.695 0.01 0.819 <0.001 0.801 <0.001 gi 0.601 0.005 0.819 <0.001 0.619 <0.001 bop 0.69 <0.001 0.71 <0.001 0.65 <0.001 intensity of inflammation 0.876 <0.001 0.785 <0.001 0.478 0.021 chronic periodontitis ppd cal tgf-β1 ecd r 0.586 0.558 p -value 0.003 0.006 0 200 400 0 5 10tg f β 1 e c d ppd 0 200 400 0 5 10t g f -β 1 ec d cal 18. muhassad f.doc j bagh college dentistry vol. 25(1), march 2013 salivary assessment oral diagnosis 105 salivary assessment of interleukin-6, c-reactive protein and albumin in ulcerative colitis patients in relation to oral findings muhassad h. al-mudhaffer, b.d.s. (1) sahar h. abdul-ghafoor, b.d.s., m.sc. (2) abstract background: ulcerative colitis disease is a chronic inflammatory condition that affects the gastrointestinal tract. in regulation of this inflammatory process, interleukin-6, c-reactive proteins and albumin have a major role. overproduction of il-6 by immunocompetent cells contributes to activate the liver to produce crp, transudation of plasma albumin and development of the inflammatory condition. elevated levels of il-6 in saliva could be expected, because the saliva-producing cells are part of the digestive system. the purpose of this study was to assess salivary il6, crp and albumin in ulcerative colitis patients in relation to oral findings. materials and methods: forty eight saliva specimens collected from three groups of subjects (sixteen newly diagnosed uc patients, sixteen uc patients on medication and sixteen healthy subjects). the specimens were centrifuged and stored at -20°c then three elisa kits were used for estimating the three variables. results: there was a significant elevation of salivary il-6, crp and albumin level in both newly diagnosed and on medication groups in comparison to healthy persons. there was a significant elevation differences of salivary il-6, crp and albumin level between newly diagnosed and on medication groups. the prevalence of aphthus ulcer was highly significant in the newly diagnosed group in comparison to the other groups. twenty five percent of patients on medication complain from candidiasis and only one patients with tempromandibular joints problem (hard clicking). conclusions: salivary il-6, crp and albumin are elevated simultaneously in uc patients, in both newly diagnosed and on medication groups, but the mean of variables in second group was lower than in the newly diagnosed group. there are no correlation between salivary il-6, crp and albumin with oral findings. key word: interleukin-6, crp and albumin, ulcerative colitis, aphthus stomatitis. (j bagh coll dentistry 2013; 25(1):105109). introduction the human body is a complementary unit physically and biochemically, its parts are interrelated one with another and with the body as a whole. the oral cavity and its contained structures are important parts which serve as an indicator of the general health status of the whole body (1). the mouth and its contained structures comprise the first part of gastrointestinal tract, the gi diseases leaves their shadows on the oral cavity, they affect oral tissues and saliva. saliva is a unique biological fluid, with an important role in the oral physiology. it is a major player in the process of oral and general health maintenance (2). patients with inflammatory bowel disease (ibd) are at increased risk of developing dental caries and oral infections. mucosal changes of ulcerative colitis (uc) in the oral cavity include stomatitis, glossitis, cheilitis, aphtous ulcerations, and pyostomatitis vegetans. the latter represents a specific marker of ulcerative colitis (3). cytokines play a key role in the initiation, augmentation, and perpetuation of the disease, since they are directly responsible for the mucosal injury. the role of cytokines involved in uc pathogenesis is characterized by a th2 atypical immune response, with high levels of il-6, il-10, and il-13, beside the classical pro-inflammatory cytokines (4). (1)m.sc. student . oral diagnosis department. college of dentistry, university of baghdad. (2)assist professor . oral diagnosis department, college of dentistry, university of baghdad. material and methods this cross-sectional study in which forty eight volunteers from (40-50) years old were recruited and divided into three groups; each contains sixteen subjects. all of them were selected from patients attending al-sadder hospital in najaf city and baghdad teaching hospital. group1: newly diagnosed ulcerative colitis patients not yet on medication group2: ulcerative colitis patients on medication. group3: healthy control subjects. inclusion criteria: 1. all patient were selected (newly diagnosed and on medication) from proctosigmoditis type of ulcerative colitis. 2. all patients in group 2 on sulfasalazine antiinflammatory drug. 3. the mean age of diagnosis was 45 years. 4. all subjects were selected from male gender. exclusion criteria: patients were selected with no sign and symptoms of any other systemic disease, smoking and gingivitis or periodontitis. method method of examination oral examination all the patients have been examined by single examiner, under standardized conditions; the oral cavity has been examined by artificial light by using a mouth mirror. the procedure of examination of oral soft tissue was done in j bagh college dentistry vol. 25(1), march 2013 salivary assessment oral diagnosis 106 sequence according to direction suggested by the w.h.o. (1987): the examination would begin with the lip, upper and lower sulcus, retro-molar area, upper and lower labial mucosa, buccal mucosa, then hard and soft palate, dorsal margin and inferior surface of the tongue, floor of the mouth were also examine. in case of oral mucosal lesion; the duration, size, clinical description, location of lesion, and finally the clinical diagnosis was stated. sample collection saliva sample unstimulated (resting) whole saliva was collected, under resting conditions between 8.011.0 a.m. patients were asked to avoid any oral hygienic procedure and rinse their mouth with water and to generate saliva in their mouth and to spit into a wide test tube (5). estimation of salivary interlukin-6 (il-6) levels for interleukins-6 quantitative determination, the method of elisa was used in duplicate procedure. the solid phase antibody was prepared by purified human il-6 antibody which has been pre-coated onto a microplate, standards reagent and samples containing il-6 were added into the wells. after washing away any unbound substances, a horse reddish peroxidase (hrp)labeled-il-6 antibody was added in the form of a complex of antibody-antigen-enzyme labeledantibody. after washing to remove any unbound antibody-enzyme reagent, tetramethylbenzidine (tmb) substrate was added. tmb substrate produced blue color when was catalyzed by the hrp enzyme. after reaching desired color intensity, the reaction was terminated by adding an acidic stop solution which changed the solution color from blue to yellow. the absorbance (od value) was determined at wave length (450) by microplate reader and the concentrations of il-6 were calculated according to a standard curve results oral findings: chi-square was used to assess the significant difference between newly diagnosed and on medication ulcerative colitis groups (table 1). about eighty percent of the newly diagnosed group complain from apthus stomatitis and only twenty five percent from on the medication group complain from candidiasis, and only one patient with tempromandibular joint problem (hard clicking ) as in figure (1, 2). table 1: chi-square comparison between ulcerative colitis groups. chisquare with oral findings without oral findings pvalue newly diagnosed 13 (81.2 ) 3 (18 ) 0.004 on ٭٭ medication 4 (25 ) 12 (75 ) ** = highly significant difference variables difference descriptive statistics and analysis of variance for salivary markers among study groups the mean, standard deviation, standard error, maximum, minimum and pvalues for interleukin-6, c-reactive and albumin are shown in tables (2, 3, 4) and figures (3, 4, 5). for all groups saliva sample were taken from subjects of age range from (40-50) years to estimate il-6, crp and albumin levels, it was found that these markers increased in ulcerative colitis patients with newly diagnosed in comparing with healthy control subjects. ulcerative colitis patient groups taking anti inflammatory medication showed that their salivary markers levels were lower than newly diagnosed group but remain higher than healthy control subjects by comparing the means of variables. one way anova test was used to examine the differences among study groups. analysis of variance between and within groups showed highly significant differences at pvalue = 0.000 in three markers tested in saliva (il-6, crp and albumin). table 2: the descriptive statistic and anova analysis of salivary il-6 among study groups. *** = very highly significant difference. table 3: the descriptive statistic and anova analysis of salivary crp among study groups. g. mean pg/ ml sd p-value 1 1484.37 235.94 0.000 ٭٭٭ 2 893.78 160.51 3 539.05 92.25 t 972.40 428.91 groups mean pg/ ml sd p-value 1 7.89 3.63 0.000 ٭٭٭ 2 0.03 0.79 3 -1.97 1.80 total 1.98 4.8 j bagh college dentistry vol. 25(1), march 2013 salivary assessment oral diagnosis 107 figure 1: the mean of saliva il-6 for all groups figure 2: the mean of saliva crp for all groups table 4: the descriptive statistic and anova analysis of salivary albumin among study groups. groups mean pg/ ml sd p value 1 11.82 1.49 0.000 ٭٭٭ 2 7.67 0.69 3 6.15 0.85 total 8.55 2.63 figure 3: the mean of saliva albumin for all groups least significance difference among study groups (lsd) test: the lsd test carried out between three groups separately that it was named group (i) and group (j), group (i) represented one of the study group that used to compare the differences with two other groups. multiple comparison (lsd) test for three dependent variables saliva il-6, crp and albumin were showing significant difference at p-value = (0.0210.000) and mean differences (md) at the 0.05 level (tables 5). table 5: least significance difference (lsd) of saliva il-6 among groups. group(i) group(j) md(i-j) p-value 1 2 7.85 *** 3 9.86 *** 2 1 -7.85 *** 3 2.01 ** 3 1 -9.86 *** 2 -2.01 ** the pearson correlations between variables ( r ): to examine the interrelationship between variables among three groups, simple scattered correlation were carried out between these measures. pearson correlation coefficient revealed significant correlation between variables at 0.01 level as in table (6) and figures (4, 5, 6). table 6: the pearson correlations between variables in all group. variables n r p-value il-6 crp 48 0.798 0.000 ٭٭٭ j bagh college dentistry vol. 25(1), march 2013 salivary assessment oral diagnosis 108 il6 20100-10 c r p p g/ m l 2000 1800 1600 1400 1200 1000 800 600 figure 4: correlation between saliva crp and saliva interleukin-6 variables il6 20100-10 al bu m in p g/ m l 16 14 12 10 8 6 figure 5: correlation between saliva interleukin-6 and saliva albumin variables discussion oral findings during examination of patients who gave saliva samples, found about eighty percent of the newly diagnosed ulcerative colitis patients complain of recurrent aphthus stomatitis (ras) and twenty five percent of the on medication group complain from candidiasis and tempromandibular joint clicking. this complication agrees with (3,6-9). temporo-mandibular joint problem (hard clicking). one of the patients on medication group (6.25%) complains from hard clicking. this may be muscular changes or bony changes (10). bony changes may be secondary to ulcerative colitis disease. this comes into agreement with daley and armstrong (9). finally, it was difficult to determine whether oral manifestations were expressions of ulcerative colitis, represent preexisting, coincidental findings, or as a direct result from medical treatment. variable differences newly diagnosis group the present study found the concentrations of il-6 increased in saliva patients with uc. this may indicate that the inflammatory process in the bowel causes a high release of il-6 in the saliva, because the saliva-producing cells are a part of the digestive tract (15). the activity of ibd might be estimated from levels of il-6 in plasma and albumin in cd patients and levels of il-6 in saliva as well as plasma and albumin in uc patients (14). salivary crp increased in patients with ulcerative colitis. the elevation of salivary crp was not surprising in inflammatory bowel disease, this come in agreement with (11). the crp was a very sensitive index of ongoing inflammation, rapidity of response and specificity for inflammation in comparison to erythrocyte sedimentation rate (esr) (12, 13). the understanding of the cytokines networks leads to important developments in both diagnostic and therapeutic phase of uc (4). variables level in patients on medication group the most common drugs used in the treatment of uc (sulfasalazine, oral and topical 5aminosalicylic acid, systemic and topical corticosteroid and immunosuppressors) corticosteroids are potent anti-inflammatory agents for moderate to severe relapses of j bagh college dentistry vol. 25(1), march 2013 salivary assessment oral diagnosis 109 ulcerative colitis. they act through inhibition of several inflammatory pathways suppressing interleukin transcription, induction of ikb that stabilizes the nfkb complex, suppression of arachidonic acid metabolism, and stimulation of apoptosis of lymphocytes within the lamina propria of the gut and maintained barrier function and decreased vascular permeability (17). therefore albumin, crp and il-6 level were decreased in saliva ulcerative colitis patients on medication group than patients without medication but still higher than that in healthy control, these salivary level depending on dose taking and indicated that these variables high sensitive mediator to any inflammatory process (17). variables correlation there were significant correlations between il-6, crp and albumin level in saliva of ulcerative colitis patients. this comes into agreement with (18,19). the microalbuminuria level in urine patients with ulcerative colitis may result from the increased renal microvascular permeability in response to increased circulating cytokines (18). the interleukin-6 is the chief stimulator of the production of most acute-phase proteins (19). variables in relation to oral findings no statistical difference was observed between t cells secreting il-5 or il-6 in patients with ras and controls (20). so these studies revealed that there is no any relation between oral findings and salivary il-6, crp and albumin level references 1. aljaafery r. dental findings with salivary physical and biochemical analysis in patients with upper gastrointestinal disorders. a master thesis, college of dentistry, university of bagdad, 1999. 2. humphrey sp, williamson rt. a review of saliva: normal composistion, flow and function. j prosthet dent 2001; 85 (2): 162-9. 3. mancheño fa, jiménez sy, sarrión mg. dental management of patients with inflammatory bowel disease. j clin exp dent 2010; 2(4): 191-5. 4. roda g, marocchi m, sartini a, roda e. cytokine networks in ulcerative colitis. ulcers 2011: 1-5 5. navazesh m. methods for collecting saliva. ann ny acad sci 1993; 694: 72-7. 6. gregory b, ho vc. cutaneous manifestations of gastrointestinal disorders. part ii. j am acad dermatol 1992; 26(3): 371-83. 7. scully c, el kabir m, samaranayake lp. candida and oral candidosis: a review. crit rev oral biol med 1994; 5 (2): 125-57. 8. macphail l. topical and systemic therapy for recurrent aphthous stomatitis. semin cutan med surg 1997; 16(3): 301-307. 9. daley td, armstrong je. oral manifestations of gastrointestinal diseases. can j gastroenterol 2007; 21 (4): 241-244. 10. martin sg, michael g, jonathan a, ship ba. burcket’s oral medicine 11th ed. canada: bc decker inc hamilton; 2008. p. 248. 11. fagan ea, dyck rf, maton pn, hodgson hj, chadwick vs, petrie a, pepyes mb. serum levels of c-reactive protein in crohn’s disease and ulcerative colitis. eur j clin invest 1982; 12(4):/351-9. 12. young b, gleeson m, crrips aw. c-reactive protein: an critical review. pathol 1991; 23(2): 118-24. 13. pepys mb. the acute phase response and c-reactive protein. the oxford textbook of medicine 3rd ed. oxford 1996. 14. larsen tb, nielsen jn, fredholm l, lund ed, brandslund i, munkholm p. platelets and anticoagulant capacity in patients with inflammatory bowel disease. pathophysiol haemost thromb 2002; 32 (2):/92-6. 15. aleksandra na, nederby nj, schmedes a, brandslund i, hey h. saliva interleukin-6 in patients with inflammatory bowel disease. scand j gastroenterol 2005; 40(12): 1444-8. 16. franchimont d, kino t, galon j, meduri gu, chrousos g glucorticoids and inflammation revisited: the state of the art. neuroimmunomodulation 2003; 10(5): 247-60. 17. parra md, tuomola m, cabezas-herrera j, ceron jj. analytical and clinical validation of a time-resolved immunofluorometric assay (tr-ifma) for canine creactive protein in serum. vet res commun 2006; 30(2): 113-26. 18. mahmud n, stinson j, o'connell ma, mantle tj, keeling pw, feely j, weir dg, kelleher d. micro albuminuria in inflammatory bowel disease. gut 1994; 35(11): 1599-604 19. gabay md, kushner md. acute phase proteins and other systemic responses to inflammation. n engl j med 1999; 340 (17): 448-54. 20. albanidou-farmaki e, markopoulos ak, kalogerakou f. antoniades dz detection, enumeration and characterization of t helper cells secreting type 1 and type 2 cytokines in patients with recurrent aphthous stomatitis. tohoku j exp med 2007; 212(2): 101-15. waffaa f.doc j bagh college dentistry vol. 25(4), december 2013 the effect of addition restorative dentistry 33 the effect of addition of untreated and oxygen plasma treated polypropylene fibers on some properties of heat cured acrylic resin waffaa i. mohammed, b.d.s. (1) intisar j. ismail, b.d.s., m.sc., ph.d. (2) abstract background: the polymethyl methacrylate is the most reliable material for the construction of complete and partial dentures, despite satisfying esthetic demand itsuffered from having unsatisfactory properties like impact strength and transverse strength. this study was designed to improve the impact strength and transverse strength of heat cure acrylic resin by adding untreated and oxygen plasma treated polypropylene fibers and investigate the effect of this additive on some properties of acrylic resin materials. materials and methods: untreated and oxygen plasma treated polypropylene fibers was added to pmma powder by weight 2.5 %. specimens were constructed and divided into 5 groups according to the using tests; each group was subdivided in to 3 subgroups. the tests conducted were impact strength, transverse strength, surface hardness, surface roughness, water sorption and solubility. data were analyzed by one way analysis of variance (anova) and least significant differences (lsd). results: after incorporation of untreated and oxygen plasma treated polypropylene fibers there was a highly significant increase in impact strength and surface hardness; while there was a non significant difference in transverse strength. also the value of water sorption increase significantly but with the limit of ada specification. conclusion:within the limit of this study it can be concluded that the reinforcement with polypropylene fibers effective method to increase fracture resistance of denture base; while reinforcement with oxygen plasma treated polypropylene fibers further increase fracture resistance. key words: acrylic resin, impact strength, transverse strength, polypropylene fibers, plasma treatment. (j bagh coll dentistry 2013; 25(4):33-38). introduction polymethyl methacrylate has proved to be the most satisfactory denture base material currently available. despite satisfying esthetic demands it is far from ideal in fulfilling the mechanical requirements of prosthesis. the main problem associated with pmma as a denture base material, is unsatisfactory strength particularly under fatigue failure inside the mouth caused by occlusal biting force and impact failure outside the mouth by dropping the dentures (1). numerous attempts have been used to strengthen pmma denture base resin such as incorporation of metal wire, the primary problem of using metal wire is poor adhesion between wire and acrylic resin matrix (2), production of alternative polymer slike polystyrene and polycarbonate, but have not been shown to produce dentures of greater accuracy with better performance (3), and incorporation of rubber phase in the bead polymer has improved the impact strength but result in increased cost (4). the other approach is the reinforcement of pmma denture base resin with fibers such as glass fibers, carbon fibers, aramide fibers, nylon fibers and polyethylene fibers (5). (1)master student. department of prosthodontics. college of dentistry, university of baghdad. (2)assistant professor. department of prosthodontics. college of dentistry, university of baghdad. in this study is going to use type of olefin fibers named polypropylene (pp) as reinforcing filler to pmma denture base resin which has many properties like high strength, good surface finish and polish, low cost and excellent biocompatibility (6). however, these fibers breakup the homogenous matrix of acrylic resin due to poor interface between fiber and resin affecting the mechanical properties. in order to avoid this, the polypropylene fiber surface energy increased by chemical or plasma treatment (7). a method based on cold plasma treatment represents an environmentally attractive alternative able to replace chemical methods, with plasma treatment surface chemistry and topography may be influenced to result in improved adhesion (8). materials and methods one hundred fifty acrylic specimens were constructed by conventional flasking technique using heat cure acrylic resin (super acryl®plus) the samples were divided into five groups according to the using tests and each group sub divided into three subgroups. three different plastic patterns were constructed by cutting plastic plates with different thickness into desired shape and dimension using highly accurate laser cutting machine. these plastic patterns were used in formation of mold j bagh college dentistry vol. 25(4), december 2013 the effect of addition restorative dentistry 34 for construction of the specimens by conventional flasking technique (9). the required weight of the powder of the polymer and polypropylene fibers was weighted by using digital electronic balance for each group. mixing of polymer powder and fibers was done randomly by using mortar and pestle until homogenous mixture was attained. mechanical and physical tests aimpact strength test the specimens were prepared with dimensions (80mm x 10mm x 4mm) (iso 179, 2000) for unnotched specimens. specimens were stored in distilled water at 370c for 48 hours before being tested (9). the impact strength test was evaluated following the procedure recommended by the iso 179 with impact testing device. the specimens were supported horizontally at each end and struck by free swinging pendulum of 2 joules. the scale readings give the impact energy in joules. the charpy impact strength of unnotched specimens was calculated in kilo joules per square meter by the following equation: impact strength = x103 (iso, 2000) e: the impact energy in joules b: is the width of the specimens in millimeters d: is the depth of the specimens in millimeters then the fracture surface of specimen examined and photographed using scanning electroning microscope (sem) to study the difference in adhesion before and after plasma treatment. figure 1: scanning electroning microscope for fracture surface of specimen (a, b) btransverse strength test specimens were prepared with dimensions (65mm x 10mm x 2.5 + 0.1mm). all specimens stored in distilled water at 37 0c for 48 hours before being tested (9). the test was performed using instron universal testing machine (wdw-200 e), each specimen was positioned on the bending fixturewhich consist of two parallel supports (50 mm apart), the full scale was 50 kg andthe load was applied with across headspeed of1mm/min. by a rod placed centrally between the supports making deflection until fracture occurs. csurface hardness test specimens of heat cure acrylic resin were prepared with a dimension (65mm x 10mm x 2.5 + 0.1mm). all specimens were stored in distilled water at 370c for 48 hours before being tested (9). surface hardness was determined by using (shore d) durometer hardness tester which is suitable for acrylic resin material. the instrument consist of spring loaded indenter (0.8mm in diameter), the indenter is attached to digital scale that is graduated from 0 to 100 units. the usual method is to press down firmly and quickly on the indenter and record the reading. three readings were done on each specimen (one in the center and other at each end) then the mean of three readings was calculated. dsurface roughness test specimens with dimensions (65mm x10mm x 2.5+ 0.1mm) were prepared to be used for surface roughness test. all the specimens were stored in distilled water at 370c for 48 hours before being tested (9). the profilometer device was used to study the effect of fiber reinforcement on the microgeometry of the test surface. this device is supplied with sharp stylus surface analyzer from a diamond to trace the profile of the surface irregularities by recording of all the peaks and recesses which characterized the surface by its scale. the acrylic specimen was placed on its stable stage and the location of the tested area was selected (the specimen was divided into three parts) then the analyzer was traversed along the tested area and the mean of three readings was calculated. ewater sorption and solubility test acrylic disc specimens were prepared by using plastic pattern having dimensions of (50mm+1mm in diameter and 0.5 mm +0.1 mm in thickness). a-before treatment bafter treatment j bagh college dentistry vol. 25(4), december 2013 the effect of addition restorative dentistry 35 the specimens were dried in desiccators containing freshly dried silica gel .the desiccator was stored in an incubator at a370c +20c for 24 hours after that the specimens were removed to room temperature for one hour then weighted with electronic balance with accuracy of (0.0001g). this cycle of weighting was repeated every day until a constant mass (m1) (conditioned mass) was reached (9). all discs of all groups were immersed in distilled water for 7 days at 370c + 20 c (9). the discs were removed from the water with a dental tweezers wiped with a clean dry towel until free from visible moisture, waved in the air for 15 seconds and weighted; this mass was recorded as (m2). the value of water sorption was calculated for each disc from the following equation: s mm wsp 12 − = (ada specification no.12, 1999) wsp = water sorption in mg/cm2 2m = the mass of the disc after immersion in distilled water (mg) 1m =the mass of the disc before immersion in distilled water (conditioned mass) (mg). s = surface area of the disc (cm2) in order to obtain the value of water solubility the discs were again reconditioned to a constant mass in the desiccator at 370c + 20c as done in the first time for sorption test and the reconditioned mass was recorded as (m3). the solubility during immersion was determined for each disc by the following equation: s mm wsl 31 − = (ada specification no.12, 1999) wsl= water solubility in mg/ cm2. m1= the conditioned mass (mg). m3= the reconditioned mass (mg). s= the surface area of the disc (cm2). results statistical analysis was done by using spss version 20.the results obtained from the measured data were classified according to the followings experimental groups: • group (a) control group • group (b) acrylic resin+ untreated polypropylene fibers • group (c) acrylic resin + 4 minutes oxygen plasma treated polypropylene fibers impact strength test the result of this test showed that group (c) exhibited the highest impact strength mean value (10.986 kj/m2); while the group (a) exhibited the lowest one (7.190 kj/m2). one way analysis of variance (anova test) indicated a highly significant difference among the studied groups (p< 0.01). table 1: descriptive data and anova test of impact strength test among studied groups anova test descriptive studied groups between groups sd mean kj/m2 n 2 df 0.864 7.190 10 control 69.976 f 0.671 9.705 10 untreated polypropylene fiber 0.000 hs pvalue 0.634 10.986 10 plasma treated polypropylene fiber transverse strength test one way analysis of variance (anova test) indicated a non significant difference among all groups (p >0.05) surface hardness test the result of this test showed that group (c) had the highest mean value (86.517); while group (a) had the lowest one (83.318). one way analysis of variance (anova test) indicated a highly significant difference among studied groups (p < 0.01). table 2: descriptive data and anova test of transverse strength test among studied groups anova test descriptive studied groups between groups sd mean n/mm2 n 2 df 3.271 95.63 10 control 0.646 f 3.766 96.801 10 untreated polypropylene fiber 0.532 ns pvalue 4.187 97.523 10 plasma treated polypropylene fiber j bagh college dentistry vol. 25(4), december 2013 the effect of addition restorative dentistry 36 table 3: descriptive data and anova test of surface hardness test among studied groups surface roughness the result of this test showed that group (c) had the highest mean value (0.915µm); while group (a) had the lowest one (0.903 µm). one way analysis of variance (anova test) indicated a highly significant difference among studied groups (p < 0.01). table 4: descriptive data and anova test of surface roughness test among studied groups anova test descriptive studied groups between groups sd mean µm n 2 df 0.007 0.903 10 control 7.135 f 0.008 0.908 10 untreated polypropylene fiber 0.003 hs pvalue 0.006 0.915 10 plasma treated polypropylene fiber water sorption test the result of this test showed that group (c) had the highest mean value (0.409 mg/cm2); while group (a) had the lowest one (0.357mg/cm2). one way analysis of variance (anova test) indicated a highly significant difference among studied groups (p < 0.01). table 5: descriptive data and anova test of water sorption test among studied groups anova test descriptive studied groups between groups sd mean mg/cm2 n 2 df 0.017 0.357 10 control 12.571 f 0.026 0.386 10 untreated polypropylene fiber 0.000 hs pvalue 0.026 0.409 10 plasma treated polypropylene fiber water solubility test the result of this test showed that group (b) had the highest mean value (0.02 mg/cm2); while group (a) had the lowest one (0.018mg/cm2). one way analysis of variance (anova test) indicated significant difference among studied groups (p < 0.05). table 6: descriptive data and anova test of water solubility test among studied groups anova test descriptive studied groups between groups sd mean mg/cm2 n 2 df 0.001 0.018 10 control 3.520 f 0.002 0.02 10 untreated polypropylene fiber 0.044 s pvalue 0.002 0.019 10 plasma treated polypropylene fiber discussion in this study used plasma treatment rather than chemical treatment for polypropylene fibers since plasma a convenient procedure and environmentally friendly technique (8). oxygencontaining plasmas were most commonly employed to improve polymer surface properties, these results might be due to the effects of chemical oxidation reactions and/ or chemical etching process. during the oxidation reactions, plasma promotes adhesion by inducing further chemical reactions with generated new chemical functional groups such as the hydroxyl group which increased the surface energy; while during the chemical etching process, this process result in chemical removal of surface material that increased the effective surface area of the polymer (i.e., surface roughning) this roughing in turn promote more intimate molecular contact between the plasma exposed fiber surface and the matrix allowing for stronger bond to occur (10). impact strength the results revealed that the addition of untreated polypropylene fibers produced a highly significant increase in impact strength mean value anova test descriptive studied groups between groups sd mean n 2 df 2.172 83.318 10 control 10.746 f 1.098 86.447 10 untreated polypropylene fiber 0.000 hs pvalue 1.843 86.517 10 plasma treated polypropylene fiber j bagh college dentistry vol. 25(4), december 2013 the effect of addition restorative dentistry 37 compared with control group, this increase which could be related to the presence of fibers which prevent the crack propagation and change in direction of cracks resulting in smaller cracks between the fibers, this can be correlated to the increased impact strength of fiber reinforcedspecimens compared to the unreinforced specimens where there is unobstructed crack propagation . these results are in agreement with results obtained by mowade et al (6). there was also a highly significant increase in impact strength mean value of specimens after incorporation of plasma treated pp fibers compared with control group, this increase could be attributed to the fact that plasma introduce functional groups on the surface of fibers there by making the surface polar, which improve the surface energy of the fiber and its compatibility with other materials (11) therefore, enhance the impact strength. these results are in agreement with results obtained by mowade et al (6). transverse strength the results revealed that the addition of untreated polypropylene fibers produced non significant difference in transverse strength mean value compared with the control group, this may be related to the fact that the random orientation of fibers allows only small portion of the reinforcement to be directed perpendicular to the applied stress. unalan et al (12) and kamble et al (13) found that reinforced acrylic with 2% by weight of glass and polyethylene fibers improved the flexural strength of the specimens compared to unreinforced pmma and bisacryl composite resins; while al momen (14) found after the addition of 5% and 10% styrene butadiene rubber into acrylic resin produce a significant decrease in transverse strength was observed duo to increase in flexibility of composite containing sbr. there was also non significant difference in transverse strength mean value after incorporation of plasma treated polypropylene fibers into pmma resin compared with control group, this due to the internal voids formed in the resinfiber composite caused by poor wetting of fibers with resin (perhaps the using fibers not undergo changes from plasma treatment), these voids were oxygen reserves that allowed oxygen to inhibit radical polymerization of the acrylic resin inside composite,this can lead to higher residual monomer content of fiber composite and affect strength. surface hardness the results revealed that the addition of untreated polypropylene fibers produce a highly significant increase in surface hardness mean value compared with control group; this increase could be related to the presence of these fibers near or at the surface of the composite which extremely hard and stiff. almomen (14) and salih (15) they found a remarkable increase in the hardness observed when the randomly oriented form of kevlar, glass and carbon fibers were added to resin. there was also a highly significant increase in surface hardness mean value after incorporation of plasma treated pp fibers to pmmaresin compare with control group this could be attributed to that treatment increase the fiber hardness. ahmad and wel (16) showed that addition of saline coupling agent only improved the interfacial bonding between the matrix and glass fibers without giving any perceptible impression to the value of hardness. surface roughness the results revealed that the addition of untreated polypropylene fibers produce non significant difference in surface roughness compared with control group, this could attributed to smooth surface of polypropylene fibers. waltimo et al (17) found significant increase in surface roughness with glass fibers reinforcement. there was a highly significant increase in surface roughness mean value of specimens after incorporation of plasma treated pp fibers compared with control group, this increase could be attributed to fact that oxygen – plasma treatment increase the surface roughness of treated polymer (11). cvelbar et al (18) and wei et al (19) revealed by using atomic force microscope (afm) that oxygen plasma treatment usually creates micro roughness on the treated surface due to an etching effect. water sorption the results revealed that the incorporation of untreated polypropylene fibers produced a highly significant increase in the water sorption of acrylic resin when compared with control group and this increase could be related to the voids and defects formed at fiber/ matrix interface in poorly impregnated regions which more readily encourage water sorption. there was also a highly significant increase in water sorption mean value of specimens after incorporation of plasma treated pp fibers j bagh college dentistry vol. 25(4), december 2013 the effect of addition restorative dentistry 38 compared with control group; this increase could be attributed to fact that plasma treatment changed totally hydrophobic surface of untreated pp fibers to hydrophilic surface due to incorporating of functional groups (7). water solubility the obtained results revealed that there was a significant increase in water solubility of the specimens reinforced with untreated polypropylene compared with control specimens, this increase could be attributed to the presence of air voids in the composite structure and the polymerization reaction inhibited by oxygen resulted in higher residual monomer content in the polymer (20) subsequent greater solubility of the polymerwill occur. there was a non significant difference in water solubility of the specimens reinforced with plasma treated polypropylene fibers compared with control group, this attributed to the transverse interlocking occurred between the reinforced plasma treated polypropylene fibers and acrylic resin may lead to decrease in the residual monomer content subsequent lesser solubility of the polymer will occur. references 1. alla rk, sajjan s, alluri vr, ginjupalli k, upadhya n. influence of fiber reinforcement on the properties of denture base resins. j biomat nanotechno 2013; 4: 91-7. 2. vojdani m, khaledi ar. transverse strength of reinforced denture base resin with metal wire and eglass fibers. j dentistry 2006; 3: 167-72. 3. smith dc. recent development and prospects in dental polymers. j prosth dent 1992; 12: 1066-78. 4. jagger dc, harrison a, jandt k. the reinforcement of dentures. j oral rehabil 1999; 26: 185-94. 5. hui s, lee y, seunghan o, won c, oda y, bae j. reinforcing effects of different fibers on denture base resin based on the fiber type, concentration, and combination. dental mater j 2012; 31(6): 103946. 6. mowade tk, dange shp, thakre mb, kamble vd. effect of fiber reinforcement on impact strength of heat polymerized polymethyl methacrylate denture base resin: in vitro study and sem analysis. j adv prosthodont 2012; 4(1): 30-6. 7. skacelova d, fialova m, stahel p, cemak m. improvement of surface properties of reinforcing polypropylene fibers by atmospheric pressure plasma treatment. 2011; belfast, uk, no. d13. 8. morent r, degeyter n, leys c, gengembre l, payen e. comparison between xps and ftir analysis of plasma treated polypropylene film surfaces. surf interface anal 2008; 40: 597-600. 9. american dental association specification no.12; 1999 for denture base polymers chicago. council on dental materials and devices. 10. wang j, chen p, li h, wang b, zhang ch, ren n. surface characteristic of poly (p-phenylene trephthalamide) fibers with oxygen plasma treatment. surf interfac anal 2008; 40: 1299-303. 11. hocker h. plasma treatment of textile fiber. pure appl chem 2002; 74(3): 423-7. 12. unalan f, dikbas i, gurbuz o. transverse strength of polymethyl methacrylate reinforced with different forms and concentrations of e-glass fibers. ohdmbsc 2010; 9: 144-7. 13. kamble vd, porkhedkar rd, mowade tk. the effect of different fiber reinforcement on flexural strength of provisional and restorative resin: an in-vitro study. j adv prosthodont 2012; 4(1): 1-6. 14. almomen mm. effect of reinforcement on strength and radiopacity of acrylic denture base material. a master thesis, department of prosthodontics, university of baghdad, 2000. 15. salih zh. the effect of fibers reinforcement on some properties of visible light cured acrylic denture base material. a master thesis, department of prosthodontics, university of baghdad, 2006. 16. ahmad i, wel ls. effect of fiber surface chemistry on the mechanical properties of glass fiber mat reinforced thermoplastic natural rubber composites. j teknologi 2006; 45: 67-79. 17. waltimo t, tanner j, vallittu pk, haapasalo m. adherence of candida albicans to the surface of polymethyl methacrylate e-glass fiber composite used in denture. int j prosthodont 1999; 12: 83-6. 18. cvelbar u, pejounik s, mozetie m, zalar a. increased surface roughness by oxygen plasma treatment of graphite/polymer composite. appl surf sci 2003; 210: 255-61. 19. wei qf, gao wd, hou dy, wang xq. surface modification of polymer nanofibers by plasma treatment. appl surf sci 2005; 245: 16-20. 20. vallittu pk, ruyter ii, kstrand i. effect of water storage on the flexural properties of eglass and silica fibers acrylic resin composite. int j prosthodont 1998; 11: 340-50. nebal f.doc j bagh college dentistry vol. 25(3), september 2013 antibacterial effect pedodontics, orthodontics and preventive dentistry158 antibacterial effect of cardamom and black tea aqueous extract on mutans streptococci in comparison to chlorhexidine (in vitro study) nebal th. shaker, b.d.s., m.sc. (1) abstract background: antimicrobial agents have been considered as having potential for the prevention of dental caries. this study aimed to test the effect of different concentrations of cardamom and black tea extracts on the sensitivity and growth of salivary mutans streptococci in comparison to chlorhexidine gluconate (0.2%) in vitro. materials and methods: in this study. mutans streptococci were isolated from saliva of 34 healthy people (aged between 22-40yrs). the bacteria was isolated, purifiedand diagnosed according to morphologicalcharacteristic and biochemical tests. aqueous extracts of cardamom and black tea were prepared. different concentrations of extracts were prepared and estimated in gm/ 100ml deionized water. the agar diffusion technique was used to determine the antibacterial activity of cardamom and tea extracts in which the inhibition of bacteria growth by different concentrations of extracts was measured by diameter of inhibition zone in millimeter. the viable count was measured in different concentrations for both types of extracts on comparison to chlorhexidine 0.2%. results: the result showed that the mutans streptococci is more sensitive to tea extract than cardamom one, where the mean value of diameter of inhibition zone was higher by tea extract than cardamom type in all concentrations and chlorohexidine0.2% is more effective than both extracts. for viable count no statistical significant difference between two extract types at concentration of 40% but there are a high statistical significant difference for other concentrations, where the chlorhexidine is moreeffective than tea type and the last one is more effective than cardamom type with p value 0.05 . conclusions: cardamom and black tea have antibacterial effect against mutans streptococci; the accused factor of dental caries. key words: cardamom, black tea, mutans streptococci, antibacterial. (j bagh coll dentistry 2013; 25(3):158-164). introduction finding healing powers in plants is an ancient idea. people on all continents have long applied poultices infusions of hundreds, if not thousands of indigenous plants, dating back to prehistory (1). cardamom is the third most expensive spice in the world (after saffron and vanilla), and the high price reflects the high reputation of this most pleasantly scented spice (2). it refers to several plants of the genera elettaria and amomum in the ginger family zingibreaceae. both genera are native to india; they are recognized by their small seed pod, triangular in cross-section and spindle shaped, with a thin papery outer shell and small black seeds. elettaria pods are light green while amomum pods are larger and dark brown commonly known as black cardamom (3, 4). the content essential oil in the seeds is strongly on storage conditions, but may be as high as 8%. in oil were found α-terpineol 45%, myrcene 27%, limonene 8%, menthone 6%, β-phenllandrene 3%, 1,8-cineol 2% and heptane 2% (5).cardamom has a strong, unique taste, with an intensely aromatic, resinous fragrance. both forms of cardamom are used as flavorings in food and drink, as cooking spices and as a medicine. it is a common ingredient in indian cooking, and is often used in backing in nordic countries such as in the finnish (1)assistant lecturer, department of preventive dentistry. college of dentistry. almustansyria university sweet bread pulla or in scandinavian bread julekake. 60% of the world production is exported to arab countries, where the large part used to prepare coffee and tea. individual seeds are sometimes chewed, in much the same way as chewing gum to neutralize the toughest breath odors (6). in traditional medicine it is used to treat infections in teeth and gums, to prevent and treat throat troubles, congestion of the lungs and pulmonary tuberculosis, inflammation of eyelids and totreat digestive disorders such as stomachaches, constipation, and dysentery. it also used to break up kidney stones and gall stones, and was reportedly used as an antidote for both snake and scorpion venom (7). cardamom is best stored in pod form because once the seeds are exposed or ground they quickly lose their flavor. the seeds show a loss of about 40% of the essential oil per year (8). one of the most popular, widely used plants all over the world is the tea plant (camellia sinesis; fam; teacea) (9). the tea plant is a shrub or semi tree belonging to the transtroemia with alternative evergreen leaves. the fresh leaves pickets from the tea plant are processed into varicose kind of tea according to the means of manufacturing methods but the three main types of tea can be classified as black, green and oolong tea.there are more than 500 various chemical elements contained in tea. black tea has many j bagh college dentistry vol. 25(3), september 2013 antibacterial effect pedodontics, orthodontics and preventive dentistry159 more components than green tea partly because of the oxidation process that occur during fermentation (10). tea consists of caffeine 1%_4%, tannin 10_24%; fluoride, cadimium, cobalt, vitamins and volatile oil have been identified among the elements in tea (11). tea plant is considered to be one of the most important medicinal plants due to its various beneficial effects. tea has antioxidant effect, antimutagenic activity; antimicrobial effects, anticarcinogenic property, reduce blood pressure and the possibility of coronary heart disease. tea improves the cognitive and psychomotor performance (12). the antibacterial activity (especially anticariogenic activity of cardamomand tea) is going to take place in this study aiming tobenefit from tea and cardamom extract to control and prevent dental caries in the future. dental caries is a microbial disease affecting mineralized tissues of teeth (13). mutans streptococcus (ms) is considered to be the most accused factors to the initiation and progression of dental caries (14). materials and methods preparation of aqueous extracts cardamom was purchased from the market. ground into fine powder in an electrical mixer. 100g of the finely powdered cardamom mixed with one liter of deionized water and kept in a water bath at 60 c for five hours, then filtered through filter paper. the extract was then left to dry at 40º c in hot air oven for evaporation of water. the extract was preserved in a refrigerator until use (15). the commercial type of tea was used in this project supplied from local supermarket. the aqueous extract was prepared by 100g of dried leaves of black tea were infused in 500ml. of boiling distilled water, and left to cool at room temperature. agitation of the infusion with magnetic stirrer had been done alternatively. then the infusion was filtered by filter paper (wattman no. 1) and the residue discarded. the extract left to dry in a petridish at room temperature, the resulted powder kept in tightly closed glass container in refrigerator until used for different concentrations(1). isolation of mutans streptococcus stimulated saliva was collected from 34 healthy individual (aged 22-40yrs). saliva was homogenized by vortex mixer for 2 minutes and serial dilutions were prepared by using normal saline then the appropriate dilutions from saliva for each microbial type was inoculated on mitissalivaris bacitracin agar (msb agar), selective media for ms; by taking 100ml from dilution (102,10-4) and spread on plates of msb agar by sterile microbiological spreader after thatincubated anaerobically by using gas pack supplied in anaerobic jar for 48 hours at 37 c followed by aerobic incubation 24 hours at 37 c(16). the colonies on msb agar were studied under microscope and gram stain was used followed by biochemical test to identify the isolates by catalase test and carbohydrate fermentation test(17).different concentrations of cardamom and black tea extracts were prepared, 40%, 80%, 120% and 160%. the agar diffusion technique was applied to study the antimicrobial effect of these concentrations on thegrowth of ms and colony counts. statistical analyses data were analyzed using spss program version 20.data were present in simple measures of mean and standard deviation, the significance of difference between studied variables was tested using student ttest for comparing between two means of independent groups. anova used to test the difference among groups and dunitti test used to compare the results of two groups with control one. p value less than0.05 was used as the level of significance. results the result revealed a high statistical significant difference by independent ttest between the two types of extracts. (p value ≤ 0.05). the result showed that the micro-organism is more sensitive to tea extract than cardamom one, where the mean value of diameter of inhibition zone was higher by tea extract than cardamom type in all concentrations as seen in table 1and figure 1. the result of anova test illustrates a high statistical significant differences (p value 0.05) regarding the mean diameter of inhibition induced by three types of extracts at all concentrations ,where the result showed that the chlorohexidine (chx) is more effective than tea extract and the latter one is more effective than cardamom one, as seen in table 2. when a comparison of inhibition zone induced by two types of extracts (tea and cardamom) and control group (chx) by dunetti test revealed high statistical significant differences in all tested concentrations (p value 0.05) where the chlorhexidine is more effective than tea and cardamom extracts in all concentrations as seen in table 3. the figures 2 and 3 showed a positive linear correlation between the diameter of inhibition zone and different concentration of each extract, where the mean of diameter of inhibition zone increased by increasing the concentration. j bagh college dentistry vol. 25(3), september 2013 antibacterial effect pedodontics, orthodontics and preventive dentistry160 counts of m.s were tested in the presence of different concentrations of cardamom and tea aqueous extract. the result revealed no statistical significant difference between two extract types at concentration of 40% but there are a high statistical significant difference for other concentrations with p value less than 0.05 as seen in table 4. the result demonstrated a high statistical significant difference among three groups at different concentrations regarding the mean viable count of ms, where the result revealed that the chlorhexidine is more effective than other groups with p value 0.05 .when the dunneti test to compare the result of viable count by two extract types with the control group (chlorhexidine),the result revealed a high statistical difference between each type of extract and control group in different concentrations with p value 0.05.table 5 and 6. discussion scientific analysis of plant components follows a logical pathway. initial screening of plants for possible antimicrobial activities typically being by using crude aqueous or alcoholic extraction and sometimes can be followed by various organic extraction methods. the aqueous extract of plants is considered to be the best way for the extract activity, in addition , the amateur herbalist will be able to prepare this extract easily(1). the sensitivity of mutans streptococci to different concentrations of cardamom and black tea aqueous extract in comparison to 0.2% chlorhexidine gluconate antimicrobial agent was tested. the zone of inhibition were found to increase when the concentration of cardamom and tea extract increased; but for tea extract zone of inhibition were higher than that seen for cardamom one. this may indicate that the sensitivity of mutans streptococci to higher concentrations of aqueous extract of tea was more than that of cardamom extract. it could due to that the antimicrobial constituents of tea was in much more amount than that obtained from cardamom extract. in the present study effects of aqueous extract of cardamom and tea on the viable count of mutans streptococci were tested. both types had antibacterial activity against mutans streptococci because they were able to reduce the viable cell count profoundly. this is a desirable property for anticariogenic agent. the results showed that no statistical significant difference between two extract types at concentration of 40% but there are a high statistical significant difference for other concentrations. chx had the greatest effect in comparison to the both. mouth washes are used to clean and deodorize the oral cavity. generally, they contain antibacterial agents and are most often used for their deodorizing, refreshing and antiseptic effects (9). the results of this study indicate that cardamom and tea had highly significant antimicrobial activity. such antimicrobial property is a desirable property for mouth washes. these findings were in coincidence with other studies (9,18-21). references 1. cowan m. plant products as antimicrobial agents. clinical microbiology reviews 1999; 12: 564-82. 2. buckingham js, petheram rj. cardamom cultivation and forest biodiversity. agricultural research, london, 2004. 3. norajit k, lua n, orapin k. antibacterial effect of five zingiberaceae essential oils. molecules 2007; 12(8): 2047-60. 4. aubertine c. cardamom in lao pdr: the hazardous future of an agroforest system product. international forest research. jakarta, indonesia, 2004. 5. kaskoos kn, mir sr. essential oil composition of fruits of amomumsudulatumroxb. j essential oil bearing plants 2008; 11: 184-7. 6. sabulal b, dan m, pradeep ns. composition and antimicrobial activity of essential oil from cardamom. acta pharm 2006; 56:473-80. 7. kumar gp, chaturvedi a. antimicrobial activity of some medicinal plants of euphorbiaceae. india drugs 2006; 43:156-9. 8. gurudutt kn, naik jp, srinivas p. volatile constituent of large cardamom (amomumsubulatumroxb). flavfragr j 1996; 11:7-9. 9. esimone c, adikwu m, nwafor s, okoklo c. potential use of tea extract as a complementary mouthwash: comparative evaluation of two commercial samples. j alternative and complementary medicine 2001; 7(5): 523-7. 10. tingli l. mechanism and clinical study on the anticaries effect of green tea polyphenols. information of chinese traditional medical science. 2002; 6: 22-3. 11. mckay d, blumberg j. the role of tea in human health. journal of the american college of nutrition 2002; 21(1):1 -13. 12. turkemen n. effect of extraction conditions on measured total polyphenol contents and antioxidant and antibacterial activities of black tea. molecules. 2007; 12(3): 484-96. 13. kidd e, jouyston-bechal s. essentials of dental caries. the disease and its management. oxford. hong kong 2002. p.1-20. 14. touys l, amsel r. anticariogenic effects of black tea (camellia sinensis) in caries-prone rate. quintessenceint 2001; 32(8):647-50. 15. rout pk, sahoo d, jena ks, rao yr. analysis of the oil of large cardamom. j essent oil res 2003; 15: 2656. 16. koneman ew, schreckenberge pc, allens sd, jr.wcw, janada wm. diagnostic microbiology. 4th ed. j.b. lippincott co., usa. 1992. j bagh college dentistry vol. 25(3), september 2013 antibacterial effect pedodontics, orthodontics and preventive dentistry161 17. fingold c, barone. methods for identification of etiologic agents of infectious disease. in: bialey and scotts diagnostic microbiology 7thedt. cv mosby co. st. louis 1986, 382-422. 18. supriya a, wakode s. antimicrobial activity of essential oil and various extracts of fruits of greater cardamom. indian j pharmaceutical sciences 2010; 72(5): 657-659. 19. gilani sr, shahid i, javed m, mehmud s, ahmed r. antimicrobial activities and physio-chemical properties of the essential oil from amomumsubulatum. int j appl chem 2006; 2:81-6. 20. al-izzy m. antibacterial effects of black and green tea extract on mutans streptococci and lactobacilli(in vitro and vivo study).m.sc. thesis. college of dentistry, baghdad university, 2005. 21. sasaki h, masumoto m, tanakat, maeda m. antibacterial activity of polyphenol components in oolong tea extract against streptococcus mutans. caries res 2004; 38: 2-8. table1. mean diameter of inhibition zone/mm by two types of extracts. conc. type of extract no. mean diameter of inhibition zone/mm ±s.d. ttest p-value 40% tea 34 6.6 .7851 7.186 hs card 34 5.3 .6974 80% tea 34 7.1 .7634 8.022 hs card 34 5.7 .6599 120% tea 34 7.6 .7855 9.041 hs card 34 6.1 .6213 160% tea 34 8.1 .6937 11.157 hs card 34 6.4 .5841 hs=highly significant figure 1: 1mean diameter of inhibition zone of ms/mm by two types of extracts in different concentrations. table 2. mean diameter of inhibition zone by different types of extracts at different concentrations concentration /extract type no. mean of inhibition zone/mm ±s.d. 95% confidence interval for mean f test p-value lower bound upper bound 40% tea 34 6.6 .7851 6.403 6.950 318.061 hs card 34 5.3 .6974 5.139 5.626 chx 34 10.6 1.1500 10.258 11.060 80% tea 34 7.1 .7634 6.904 7.437 275.080 hs card 34 5.7 .6599 5.552 6.013 chx 34 10.6 1.1500 10.258 11.060 120% tea 34 7.6 .7855 7.385 7.933 234.952 hs card 34 6.1 .6213 5.889 6.323 chx 34 10.6 1.1500 10.258 11.060 160% tea 34 8.1 .6937 7.899 8.383 217.456 hs card 34 6.4 .5841 6.202 6.610 chx 34 10.6 1.1500 10.258 11.060 hs=highly significant 0 2 4 6 8 10 conc.40% conc.80% conc.120% conc.160% chart title tea ex card ex. j bagh college dentistry vol. 25(3), september 2013 antibacterial effect pedodontics, orthodontics and preventive dentistry162 table 3. compares of mean of inhibition zone between two types of extracts and control group (chx) dependent variable (i) type of extract (j) type of extract (control group) mean difference (i-j) sig. 95% confidence interval lower bound upper bound 40% tea chx -3.9824* .001 -4.472 -3.493 card chx -5.2765* .001 -5.766 -4.787 80% tea chx -3.4882* .001 -3.969 -3.007 card chx -4.8765* .001 -5.357 -4.396 120% tea chx -3.0000* .001 -3.479 -2.521 card chx -4.5529* .001 -5.032 -4.074 160% tea chx -2.5176* .001 -2.978 -2.057 card chx -4.2529* .001 -4.713 -3.793 chx=chlorhexidine figure 2. correlation between different concentrations of cardamom extract and mean diameter of inhibition zone figure 3. correlation between different concentrations of tea extract and mean diameter of inhibition zone 4 5 6 7 8 0% 50% 100% 150% 200% inhibition zone/mm by card ex. for different conc. linear (inhibition zone/mm by card ex. for different conc ! 5 5% 6 5% 7 5% 8 5% 0% 50% 100% 150% 200% mean ofinhibition zone in mm by tea ext.at diff.conc. mean ofinhibition zone in mm by tea ext.at diff.conc. linear ( mean ofinhibition zone in mm by tea ext.at diff.conc ! j bagh college dentistry vol. 25(3), september 2013 antibacterial effect pedodontics, orthodontics and preventive dentistry163 figure 4: mean diameter of inhibition zone by different concentrations of two types of extracts and control group. table 4: mean count of ms by different concentrations for two types of extracts concentrationstype of extract n0. mean count of ms ±s.d. ttest p value zero time tea 34 76.59 11.004 0.358 0.721 card 34 75.65 10.657 40% tea 34 67.00 9.851 -1.684 0.09(ns) card 34 70.50 9.740 60% tea 34 61.53 8.999 -2.587 0.012 card 34 67.29 9.373 120% tea 34 58.00 9.036 -2.587 0.002 card 34 64.74 9.571 160% tea 34 52.68 9.550 -3.365 0.001 card 34 60.32 9.187 table 5: mean count of ms in different concentration for three types of extracts concentrations/extracts no. mean of viable count of ms ±s.d. 95% confidence interval for mean f test p value lower bound upper bound zero time tea 34 76.59 11.004 72.75 80.43 128.465 hs card 34 75.65 10.657 71.93 79.37 chx 34 44.59 5.349 42.72 46.45 40% tea 34 66.50 9.851 63.06 69.94 90.006 hs card 34 70.50 9.740 67.10 73.90 chx 34 44.59 5.349 42.72 46.45 60% tea 34 61.53 8.999 58.39 64.67 71.961 hs card 34 67.29 9.373 64.02 70.56 chx 34 44.59 5.349 42.72 46.45 120% tea 34 57.56 9.036 54.41 60.71 52.691 hs card 34 64.74 9.571 61.40 68.07 chx 34 44.59 5.349 42.72 46.45 160% tea 34 52.68 9.550 49.34 56.01 30.925 hs card 34 60.32 9.187 57.12 63.53 chx 34 44.59 5.349 42.72 46.45 j bagh college dentistry vol. 25(3), september 2013 antibacterial effect pedodontics, orthodontics and preventive dentistry164 table 6. comparison of mean viable count between two extract types and control group concentrations (i) type of extract (j)type of extract (control) mean difference in mean of viable count of ms (i-j) p value. 95% confidence interval lower bound upper bound zero time tea chx 32.000* .001 26.90 37.10 card chx 31.059* .001 25.96 36.16 40% tea chx 21.912* .001 17.25 26.58 card chx 25.912* .001 21.25 30.58 60% tea chx 16.941* .001 12.53 21.36 card chx 22.706* .001 18.29 27.12 120% tea chx 12.971* .001 8.51 17.44 card chx 20.147* .001 15.68 24.61 160% tea chx 8.088* .001 3.60 12.58 card chx 15.735* .001 11.24 20.23 figure 5. mean of viable count of ms by different concentrations of two types of extracts and control group zainab f.doc j bagh college dentistry vol. 28(2), june 2016 evaluation of the oral diagnosis 63 evaluation of the level of melatonin, cortisol and iga in saliva of patients with oral lichen planus lesions zainab zamil hamdan, b.d.s. (1) jamal noori ahmed, b.d.s., m.s., ph.d. (2) hazem hamid hamdo, b.sc. m.sc. (3) abstract back ground: oral lichen planus is a chronic inflammatory disease that affects the mucous membrane of the mouth. several researchers suggest that oxidative stress is implicated in the pathogenesis of this disorder. it has been hypothesized that melatonin is powerful anti-oxidants and can easily cross the cell membrane and is considered a free radical scavenger of hydroxid, oxygen and nitrogen dioxide, cortisol as a stress hormone and the immunoglobulin a as first line of defense and protection to the mucous membrane of the mouth are interrelated factors for the emergence of oral lichen planus. aim of this study was to evaluate the level of melatonin, cortisol and iga in saliva of patients with oral lichen planus lesions in comparison with participants with normal oral mucosa. materials and methods: in this study seventy five subjects with age 18 and over were included. the subjects were divided into two groups; control group, this group comprised of 41 subjects with normal oral mucosa and the study group, which comprised of 34 subjects with clinically and histopathologically diagnosed oral lichen planus lesion. the samples were selected from patients attending college of dentistry/university of baghdad and cases that recruited to the al-emmam ali hospital / in baghdad /dermatology department. samples collection started from 2/ may 2013 to 23/ january 2014.saliva samples were collected between 10-12 am. high performance chromatography (hplc) analyzing technique was used for estimating the salivary melatonin and cortisol level. iga level was measured by eliza method. results: the mean salivary melatonin level in patients with oral lichen planus was 4.786 µg/ml and the mean saliva melatonin level in normal person was 8.759 µg/ml. significant difference (p<0.01) was observed in the salivary melatonin levels between the study and control group. the mean salivary cortisol level in patients with olp was 0.730 µg / ml and the mean saliva cortisol level in normal persons was 0.165 µg/ml. significant difference (p<0.01) was observed in the salivary cortisol levels between the study and control, group. the mean salivary iga level in patients with olp was 221.4 µg/ml and the mean saliva iga level in normal person was 125.8 µg/ml. there was a high significant difference (p<0.01) the study and control groups. conclusions: the level of salivary melatonin was lower in patients with oral lichen planus, however cortisol and iga was higher when comparing the salivary level with that of the control groups. key words: lichen planus, melatonin, cortisol, siga. (j bagh coll dentistry 2016; 28(2):63-68). introduction certain diseases can cause alteration of the body tissues in general and the oral cavity in particular, one of these diseases is lichen planus which is a mucocutanueous inflammatory disease of unknown origin. the skin and oral mucosa are the most frequently involved areas. other mucous membranes (including the genitalia, esophagus, and conjunctiva) and skin appendages (e.g. scalp hair and nails) can also be affected (1). oral lichen planus is a chronic inflammatory disease of unknown etiology that affects the mucous membrane of the oral cavity (2). the reported prevalence rates of olp vary from 0.5% to 2.2% of the general population. it is more frequently observed, in middle-aged women, female to male ratio is 1.4:1 (3). it occurs more commonly in the mucosa than the cutaneous form and tends to be more persistent and more resistant to treatment. oral lesion may accompany, precede or follow cutaneous lesion, also affect all racial groups (4-7). (1)master student, department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. (3) assist. lecturer, baghdad college of pharmacy. many clinical forms of oral lichen planus are recognized, the reticular, erosive or ulcerative, papular, plaque-like, atrophic, bullous and pigmented (8). the etiology of this cellular degeneration is believed to be attributed to sub epithelial infiltration of t-lymphocytes that contributes to the local production of cytokines which in turn can stimulate production of reactive oxygen species (ros) and cause oxidative damage to the tissues (9). the who considers olp as a precancerous condition; the premalignant potential of olp is still debatable. malignant transformation has been estimated to occur in 0.5 – 2.9% of the olp patients (4,10). since etiology is unknown, there is no cure for lichen. the symptomatic treatment has been focused on reducing the subjective discomfort and to maintain or improve the quality of life (11). in recent years, there has been an increasing research interest in oxidation of biological systems including free radicals, reactive oxygen species (ros), oxidative stress and antioxidant defence mechanisms in inflammatory and chronic degenerative diseases and during carcinogenesis j bagh college dentistry vol. 28(2), june 2016 evaluation of the oral diagnosis 64 (12-14). oxidative stress results from the metabolic reactions that use oxygen and represents a disturbance in the equilibrium status of prooxidant/antioxidant reactions in living organisms (15). it has been found that ros produced by keratinocytes, fibroblasts and various inflammatory cells could result in disequilibrium between the pro-oxidants and antioxidants (16). reactive oxygen metabolites lead to destruction and damage to cell membranes by lipid peroxidation (12). melatonin is the principal secretory product of the pineal gland. it has immunomodulatory and antioxidant activities. arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen (17). steroid hormone cortisol released in response to stress which is one of the factors that leads to or triggering the oral lichen planus. immunoglobulin a (iga) is an antibody that plays a critical role in mucosal immunity (18). iga serves an important defending function at mucous membrane surfaces, which are the main entry sites for most pathogenic organisms. rabiei et al. found that the salivary cortisol and iga levels are correlated with the incidence of olp, and one may consider the salivary iga and cortisol levels as a possible indicator in the creation or development of olp lesions (19). the following study aimed to evaluate the salivary melatonin, cortisol and iga levels in patients with olp and normal subjects. subjects, materials and methods seventy five subjects with age 18 and over were included in this study. the subjects were divided into two groups; control group, this group comprised of 41 subjects with normal oral mucosa and the study group, this group comprised of 34 subjects with clinically and histopathologically diagnosed oral lichen planus lesion. thorough clinical history was obtained from the participants. oral cavity was examined by oral diagnosis set under artificial light. after proper clinical examination and required investigation (biopsy), clinical diagnosis was established. the procedure of the study was explained to the recruited subjects and informed consent was obtained before starting the procedure. the participants were instructed not to eat, drink or take any medication 1hr before the sample collection, and then they were asked to rinse their mouth with tap water to remove any derbies before the saliva samples collection. unstimulated whole saliva was collected for the analyses in order to avoid any changes in the chemical composition of saliva initiated by stimulation (20). saliva was collected between 1012 a.m. the collected saliva samples were centrifuged at 3000 rpm for fifteen minutes. the supernatant was aspirated for estimating the salivary analysis. hplc – uv detector was used for estimation the salivary melatonin and cortisol level. for evaluation the level of salivary iga the elisa method was used. results in this study, 34 patient with olp aged 20-63 years and a mean age of 45.3 years and 41 subject with normal oral mucosa aged 18-65 years old with mean age of 54.7 years were studied. majority of olp cases (24 cases) 75% were above 30 years of age. the predominance of olp was among female patients who showed 29 cases (85.3%); and 5 cases (14.7%) of olp were male, with a female to male ratio was 5.8:1. the distribution result of the study groups regarding gender and lesion form with comparisons significant has shown a non significant different between the two groups (p<0.05), since 24.1% of the female and 0.0% of male group were having plaque like lesion figure (3), while 48.3% of female and 80% of male were having reticular form of lesion, figure (4) and the leftover of 27.6% female and 20.0% of male were having erosive form of lesion, figure (5) ,these data illustrated in table (1). j bagh college dentistry vol. 28(2), june 2016 evaluation of the oral diagnosis 65 table 1: distribution of lesion form factor and gender with comparisons significant lesion form freq. & percents gender total c.s. (*) p-value male female plaque freq. 0 7 7 c.c.= 0.242 p=0.348 ns % lesion form 0.0% 100% 100% % gender 0.0% 24.1% 20.6% reticular freq. 4 14 18 % lesion form 22.2% 77.8% 100% % gender 80% 48.3% 52.9% erosive freq. 1 8 9 % lesion form 11.1% 88.9% 100% % gender 20.0% 27.6% 26.5% total freq. 5 29 34 % lesion form 14.7% 85.3% 100% % gender 100% 100% 100% (*)ns: non sig. at p>0.05 table 2: levels of the three parameters (µg/ml) for the study and control groups c.s.(*) z-value mann-whitney u sd median mean no group parameter hs -2.618 451 2.344 5.001 4.786 34 study melatonin (µg/ml) 6.235 5.800 8.759 41 control hs -4.163 306 0.691 0.280 0.730 34 study cortisol (µg/ml) 0.132 0.140 0.165 41 control hs -3.172 399 151.3 176.9 221.4 34 study siga (µg/ml) 69.4 82.4 125.8 41 control (*) hs: sig p<0.01 figure 6: cluster bar chart of the studied distribution of gender and lesion form factors figure 3: plaque like olp lesion at left side of palate figure 4: reticular form of olp at the left side of the buccal mucosa figure 5: erosive form of olp at the right buccal mucosa j bagh college dentistry vol. 28(2), june 2016 evaluation of the oral diagnosis 66 the result has shown a non normal distribution data of melatonin, cortisol and siga. mann – whitney u test was used for all readings of the studied parameters and the median values assessed to compare between the groups (table 2). high significant difference at (p<0.01) observed between the study and control groups. control group has shown higher readings of melatonin level (µg/ml) compared with the study groups (fig. 7). figure 7: melatonin of the study and control groups there was a high reading of cortisol level in saliva compared with that of the control group. the results showed that there was a highly significant different (p<0.01) between the study group and control group (fig. 8). figure 8: cortisol of the study and control groups based on the elisa test the results have shown that the study group reported a high readings of siga compared with the control group (fig. 9) with highly significant difference (p<0.01). figure 9: salivary iga of the study and control groups discussion in this study the patients under steroid or immunomodulation or cytotoxic drug, pregnant or breast feeding women and patient under medication that might cause lichenoid lesion like (antihypertensive, diabetic and sulfa drug) were excluded. lichen planus is a common, chronic, autoimmune, mucocutaneous disease affecting the skin, genital mucosa, scalp, nails, as well as the oral mucosa. studies and researches have been going on to elucidate the main causes of disease in addition to explore the factors that may initiate the emergence of the disease. identifying the causes will enhance the treatment or reaching to a specific therapy. furthermore avoiding the occurrence of the precipitating factors and the appropriate treatment will be in hand to treat the lesion radically rather than just symptomatic relieve (soreness, burning sensation or discomfort).melatonin, cortisol,and iga level in saliva were measured in patients with oral lichen planus and compared with that of the control group to determine if they could be used as marker of existence of the lesion or assess the activity of the disease. the samples were collected from participants; their age was ranged between 18 years and over. the first group was the study group, they were patients having oral lichen planus lesion and their mean age was 45.3 years. the control group was the second group consisted of participants having normal oral mucosa and their mean age was 54.7 years. the study revealed that the majority of cases (24 cases) 82% were above 30 years of age and this was in consistent with the other reported studies (21). predominance of olp among female patients was observed, which showed 29 cases (85.3%) of oral lichen planus were females; and 5 cases (14.7%) of olp were males, with a female to male ratio was 5.8:1 and this was in agreement with other studies (22-24). the reticular form was the most frequent clinical form observed, they were 18 cases (52.9%) followed by the erosive form, 9 cases (26.5%) then the plaque like form, 7 cases (20.6%). this finding was also noticed in harmony with result reported by other investigators (21,23,25). melatonin, known chemically as n-acetyl-5methoxytryptamine, is a hormone found in animals, plants, and microbes (26, 27). in animals, circulating levels of melatonin vary in a daily cycle, thereby allowing the entrainment of the circadian rhythms of several biological functions (28). j bagh college dentistry vol. 28(2), june 2016 evaluation of the oral diagnosis 67 the hormone is synthesized by the pineal gland and a variety of other body organs; melatonin had been reported to play a role in protecting the oral cavity from tissue damage through its antioxidant, anti-inflammatory or immunomodulator activity (29). cortisol is a natural steroid hormone produced by the adrenal gland cortex. it has a strong diurnal variation, generally high early in the early morning and falling during the day time. stress induces increased cortisol secretion that counteracts inflammatory reactions. in this study, the correlation between the level of salivary cortisol and the olp was analyzed. iga is the secretory immunoglobulin exists in the saliva as well as other body secretory fluid. it is the first line of the host defense against pathogens that invades the mucosal surfaces. salivary iga is antibody responsible for oral immunity by preventing microbial adherence, neutralizing enzymes, toxins and viruses (30). it was theorized that serum level of immunoglobulin may play a role in the pathogenesis of oral mucosal diseases, or reflect clinical changes in these conditions (31). increased levels of serum iga in patients with olp were reported (32, 33). the evaluation of iga in saliva was performed by elisa assay through which the optical density (od) was measured and the concentrations calculated by using the quadratic equation. hplc system has been used to estimate the salivary melatonin and cortisol level. hplc system was used for its advantages which include; speed (allow analysis to be done in a shorter time), sensitivity, accuracy and high resolution. the results of melatonin level have shown highly significant difference between the study and control groups (p<0.01), since the control group has shown higher readings of melatonin level (µg/ml) compared with the study groups. up to our knowledge, there is no study considering the level of melatonin in patients with oral lichen planus lesion in order to compare it with the results of the present study. however, these results support the previous findings of the researchers which revealed the protective role of melatonin through its antioxidant and free radical scavenger, anti inflammatory or through immunomodulatory activity of this hormone (34,35). psychological stress which is one of the significant causal factors of oral lichen planus may have an effect on the interpretation of this difference between the levels of melatonin of two groups. raff and benloucif and their colleagues have reported that chronic stress deplete melatonin and causes the production of too much cortisol which lowers melatonin, therefore melatonin can be considered a stress protective hormone act by keeping down the hyper production of cortisol (the stress hormone) since melatonin can help control excess cortisol production, this may also be involved in lowering adrenal function (36, 37). it was also suggested that melatonin could be used therapeutically, for instance locally in the oral cavity to treat diseases such as bacterial and viral lesions, postsurgical wounds, and oral surgeries, lichen planus and oral cancers (38). about the cortisol level the results showed that there was a highly significant difference (p<0.01) between the study group and control group. there was a high reading of cortisol level in saliva compared with that of the control group. this result is in agreement with previous results from koray et al. who studied the relation between levels of cortisol (the stress hormone) in the saliva of fourty patients with oral lichen planus. the analysis compared salivary cortisol levels in these patients with the control group (39). the authors concluded that salivary cortisol level were considerably higher in patients with oral lichen planus compared to those without disease, further strengthening the ties between salivary cortisol levels and oral lichen planus, ivanovski et al. 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(a) nidhal h. ghaib, b.d.s., m.sc. (b) abstrac background: because of the demands for aesthetic orthodontic appliances have increased, aesthetic archwires have been widely used to meet patient's aesthetic needs. the color stability of aesthetic archwires is clinically important, any staining or discoloration will affect patient’s acceptance and satisfaction. this study was designed to evaluate the color stability of different types of aesthetic archwires after immersion into different types of mouth washes. materials and methods: four brands of nickel titanium coated aesthetic arch wires: epoxy coated (orthotechnology and g&h) and teflon coated (dany and hubit) were evaluated after 1 week, 3 weeks and 6 weeks of immersion into two types of mouthwashes (listerine with alcohol and listerine without alcohol). color change measurements were performed by using spectrophotometer vita easyshade compact according to the commission internationale de i’eclairage l*a*b* color space system. results: the results of this study showed that there were highly significant differences in color change values among all brands of aesthetic archwires at various immersion media. on the other hand, a significant difference was found between dany and orthotechnology aesthetic archwires at 1 week immersion in distilled water. listerine with alcohol mouthwash produced more color changes of aesthetic archwires and color change value increases with the time of immersion. conclusions: all brands of aesthetic archwires showed different degrees of color changes but most of these changes were not visible or clinically acceptable. key words: color stability, aesthetic archwires, mouthwash. (j bagh coll dentistry 2017; 29(3):100-105) introduction aesthetic, is one of major concerns during orthodontic treatment. the great demand for better aesthetics has led manufacturers to develop appliances which combine both acceptable aesthetics for the patient and adequate technical performance for the clinician. there are many aesthetic brackets and archwires in the markets when compared to mid-1990s (1-3). most of the orthodontic appliance components are metallic and silver in color. by the introduction of aesthetic brackets made of ceramic or composite, which become more popular, the aesthetic problem is partially solved, but the archwires are still made of metals such as titanium molybdenum alloy, nickel-titanium or stainless steel. lately, coated metallic and fiber-reinforced archwires have been introduced to overcome this aesthetic problem. fiber-reinforced arch wires are experimental and not universally commercial available, there are good anticipations from them for the future (2,4,5). materials used in archwire coatings are colored polymers or inorganic materials like polytetrafluoroethylene (teflon), epoxy-resin, parylene-polymer, synthetic fluoride resins or less (a) master student, department of orthodontics, college of dentistry, university of baghdad. (b)professor, department of orthodontics, college of dentistry, university of baghdad. commonly palladium coverings to produce aesthetic archwires which simulate the color of teeth (2,6). the color stability of aesthetic archwires is clinically important during orthodontic treatment. ideally, the color of aesthetic archwires should match that of natural teeth and aesthetic brackets, but the color of natural teeth varies according to color measurement protocol, race, age and gender (3,4). however, some authors have suggested that the color of coated archwires tends to change over time and the coating splits during use in the mouth exposing the underlying metal (7). there are internal and external causes of discoloration of aesthetic arch wires. external discoloration may be caused by food dyes and colored mouth rinses, the type of coating material and its surface roughness play important roles in the extent of the discoloration. the amount of color change can be influenced by a number of factors, such as oral hygiene and water absorption (8). this study was designed to evaluate the color stability of different types of aesthetic archwires after immersion into different types of mouth washes. j bagh college dentistry vol. 29(3), september 2017 color stability of pedodontics, orthodontics and preventive dentistry 101 materials and methods the samples preparation the samples consisted of maxillary nickel titanium coated aesthetic archwires (0.018 *0.025 inch) with different coating materials and from different companies, they were: epoxy coated (orthotechnology company / u.s.a. and g & h company/ u.s.a.) and teflon coated (dany company/korea and hubit company/korea). thirty six samples (nine samples from each company) were prepared; each sample was made by cutting the preformed archwires into two halves, then putting ten halves of the aesthetic archwires segments together and uniting their free ends firstly by the light cure composite resin (fig. 1), because it set quickly so it becomes easier to use the ethyl cyanoacrylate (super glue) to get more fixation, therefore; the sample resembles a strip (fig. 2) (9,10). the ethyl cyanoacrylate can tolerate the humidity so the samples stay as strips in the mouthwashes during the testing time. the coating surface of each wire segment was facing into the same direction so that the color could be measured properly. fig. 1: uniting the ten halves of the coated archwires segments together by light cure composite resin fig. 2: sample from each company resembles a strip the samples grouping the samples were grouped according to different time intervals which are: 1 week, 3 weeks and 6 weeks. for each time interval each group contains four strips, one strip from each company as follow: distilled water as a control group listerine with alcohol listerine without alcohol listerine mouthwashes preparation two types of listerine mouth washes (listerine with alcohol and listerine without alcohol johnson & johnson, uk.) used in this study were ready made solution. equal amounts of mouth washes (500ml) were poured in covered containers to be ready for the designed procedure. color measurements the color measurement of each sample was performed by using a spectrophotometer vita easyshade compact (vita zahnfabrik, bad sackingen, germany) (fig. 3). fig. 3: spectrophotometer vita easyshade compact after numbering the samples of each company from 1 to 4; 1 for dany company, 2 for hubit company, 3 for orthotechnology company and 4 for g&h company by permanent marker that couldn’t be removed by the mouth washes, they were incubated in distilled water at 37°c for 24 hours, baseline measurements (t0) were done. then, the samples were divided into three main groups according to the immersion media (distilled water as a control media, listerine with alcohol and listerine without alcohol) and immersed in separate containers for 30 seconds twice daily, according to the manufacturer's instructions. during immersion, the samples were incubated at 37°c. after that the samples were stored in distilled water in the incubator at 37°c which is the temperature of the human body. color change measurements were calculated after 1 week (t1), 3 weeks (t2), and 6 weeks (t3). before each color measurement, the samples were removed from the mouthwashes and rinsed with distilled water for 5 minutes. excess water was removed by tissue papers and the samples were allowed to dry (4). the samples were fixed and stabilized on white card boards (11). before performing the color measurements, the (4 strips; 1 strip from each company) j bagh college dentistry vol. 29(3), september 2017 color stability of pedodontics, orthodontics and preventive dentistry 102 spectrophotometer vita easyshade compact was adjusted and calibrated according to the manufacturer’s instructions and it was hold by a special holder and keep the tip of it perpendicular and in contact with archwires surface using ruler as a guide (fig. 4) (5,11). fig. 4: the tip of vita easyshade compact was perpendicular and in contact with archwires surface the color measurements were taken from twelve reference points which located at different distances from the beginning of the coating material and these points were recognized by permanent marker at the posterior surface of the sample. five measurements of each reference point were performed and the average was calculated (4,5,9). color changes were characterized using the commission internationale de l’eclairage l*a*b* color space system (cie l*a*b*), it depends on the following coordinates: l* describes lightness with values from 0 (black) to 100 (white), a* describes the red/green coordinate, with +a* indicating red and -a* indicating green and b* describes the yellow/blue coordinate, with +b* indicating yellow and -b* indicating blue (4,12-14). total color change δ e* value was measured by this equation: δe* = (δl*2 + δa*2 + δb*2)1/2 (4,14), where δl*, δa* and δb* are differences in l*, a* and b* values between baseline measurement (t0) and measurement after immersion at each time interval (t1, t2, t3) as follows: δ l* = l2 _ l1 δ a * = a 2 – a1 δ b* = b2 – b1 then relate the δe* values to the clinical environment by converting the data to national bureau of standards (nbs) units (9,14,15) as follow: nbs units = δ e* × 0.92 statistical analyses data were collected and analyzed using spss (statistical package of social science) software version 19.the following statistics were used: adescriptive statistics: including mean, standard deviation (s.d.), minimum (min.) and maximum (max.) values. binferential statistics: including: 1. one-way anova test: was used to compare the δe* value (color change) among the different media and wire brands. 2. tukey’s honestly significant difference test (hsd): was performed to test any statistically significant difference in δe* value (color change) between any two groups. in the statistical evaluation, the following levels of significance were used as follow: ns non-significant p>0.05 s significant 0.05≥p>0.01 hs highly significant p≤0.01 results table (1) showed total color changes (δe* values) and national bureau of standards (nbs) units of the aesthetic archwires at different time intervals of immersion in various media. it was found that hubit aesthetic archwires were the least color stable while orthotechnology aesthetic archwires were the most color stable. listerine with alcohol caused more color changes of aesthetic archwires than listerine without alcohol and color change value increases with the time of immersion. although all tested aesthetic archwires showed color changes among all immersion media at different time intervals but not all these color changes are clinically important. from clinical point of view, color changes can be expressed according to δe* values and nbs units, there were color changes not appreciable by the human eye (δ e* < l, trace and slight color change) while clinically acceptable color changes which appreciable by skillful operator (3.3 > δ e* > l, slight and noticeable color change). but clinically unacceptable color changes which appreciable by non-skilled persons (δ e* > 3.3, appreciable color change) (9,14-16). table (2) and (3) showed anova test and tukey hsd test results. it was found that there were highly significant differences in color changes (δe* values) among all aesthetic archwires brands in all immersion media at different time intervals. j bagh college dentistry vol. 29(3), september 2017 color stability of pedodontics, orthodontics and preventive dentistry 103 on the other hand, a significant difference was found between dany and orthotechnology aesthetic archwires at 1 week immersion in distilled water. table 1: descriptive statistics of δe* values and national bureau of standards (nbs) units of aesthetic arch wires in various immersion media at differenttime intervals. companies media duration n mean s.d. min. max. nbs unit color change dany distilled water 1 week 12 0.141 0.002 0.138 0.146 0.12972 trace 3 weeks 12 0.273 0.003 0.268 0.277 0.25116 trace 6 weeks 12 0.286 0.001 0.284 0.289 0.26312 trace listerine with alcohol 1 week 12 0.539 0.004 0.534 0.546 0.49588 trace 3 weeks 12 1.014 0.008 1.010 1.040 0.93288 slight 6 weeks 12 1.536 0.002 1.532 1.539 1.41312 slight listerine without alcohol 1 week 12 0.323 0.003 0.320 0.329 0.29716 trace 3 weeks 12 0.494 0.002 0.490 0.498 0.45448 trace 6 weeks 12 0.896 0.002 0.892 0.899 0.82432 slight hubit distilled water 1 week 12 0.342 0.003 0.338 0.347 0.31464 trace 3 weeks 12 0.697 0.002 0.693 0.699 0.64124 slight 6 weeks 12 0.726 0.004 0.719 0.730 0.66792 slight listerine with alcohol 1 week 12 1.396 0.004 1.389 1.399 1.28432 slight 3 weeks 12 2.132 0.002 2.128 2.135 1.96144 noticeable 6 weeks 12 3.358 0.002 3.354 3.360 3.08936 appreciable listerine without alcohol 1 week 12 0.852 0.002 0.849 0.856 0.78384 slight 3 weeks 12 1.244 0.003 1.240 1.249 1.14448 slight 6 weeks 12 2.266 0.003 2.260 2.270 2.08472 noticeable ortho technology distilled water 1 week 12 0.123 0.003 0.118 0.127 0.11316 trace 3 weeks 12 0.213 0.002 0.210 0.217 0.19596 trace 6 weeks 12 0.253 0.038 0.200 0.300 0.23276 trace listerine with alcohol 1 week 12 0.637 0.003 0.630 0.643 0.58604 slight 3 weeks 12 1.065 0.031 1.010 1.100 0.9798 slight 6 weeks 12 1.804 0.002 1.801 1.808 1.65968 noticeable listerine without alcohol 1 week 12 0.242 0.002 0.238 0.246 0.22264 trace 3 weeks 12 0.341 0.003 0.337 0.346 0.31372 trace 6 weeks 12 0.748 0.005 0.740 0.755 0.68816 slight g&h distilled water 1 week 12 0.313 0.029 0.280 0.380 0.28796 trace 3 weeks 12 0.456 0.004 0.450 0.461 0.41952 trace 6 weeks 12 0.491 0.003 0.488 0.496 0.45172 trace listerine with alcohol 1 week 12 1.310 0.054 1.200 1.390 1.2052 slight 3 weeks 12 1.841 0.004 1.836 1.850 1.69372 noticeable 6 weeks 12 2.882 0.003 2.879 2.887 2.65144 noticeable listerine without alcohol 1 week 12 0.703 0.003 0.700 0.710 0.64676 slight 3 weeks 12 0.813 0.003 0.810 0.818 0.74796 slight 6 weeks 12 1.246 0.004 1.240 1.252 1.14632 slight table 2: anova test and tukey hsd test results of aesthetic arch wires and the effect of aesthetic arch wires brand. duration media f-test p-value tukey hsd test dany vs. hubit dany vs. orthotec dany vs. g&h hubit vs. orthotec hubit vs. g&h orthotec vs. g&h 1 week distilled water 722.576 0.000(hs) 0.000(hs) 0.017(s) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) listerine with alcohol 1007032.162 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) listerine without alcohol 131963.910 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 3 weeks distilled water 72137.972 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) listerine with alcohol 722497.476 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) listerine without alcohol 262314.062 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 6 weeks distilled water 1580.672 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) listerine with alcohol 1125902.728 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) listerine without alcohol 417999.534 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) j bagh college dentistry vol. 29(3), september 2017 color stability of pedodontics, orthodontics and preventive dentistry 104 table 3: anova test and tukey hsd test results of aesthetic arch wires and the effect of various immersion media. companies duration f-test p-value tukey hsd test control vs. lis a control vs. lis w lis a vs. lis w dany 1 week 3103525.149 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 3 weeks 1585764.170 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 6 weeks 7821098.786 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) hubit 1 week 3718981.182 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 3 weeks 5787882.082 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 6 weeks 6349430.423 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) ortho technology 1 week 723610.659 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 3 weeks 64977.088 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 6 weeks 87695.362 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) g&h 1 week 17658.179 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 3 weeks 1882589.490 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) 6 weeks 5123299.815 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) *lis. a (listerine with alcohol), *lis. w (listerine without alcohol). discussion the color stability of aesthetic archwires is an important factor in the success of an aesthetic orthodontic treatment, but the color of these archwires tends to change overtime (7). the sensitivity of the human eye in observing small color differences is limited and the interpretation of visual color comparisons is subjective. instrumental measurements minimize the subjective interpretation of visual color comparisons, therefore; spectrophotometer is used instead of visual evaluation (4,5). recently, vita easyshade compact is one of the latest spectrophotometers which available for clinical use. this instrument is small, wireless, easy to handle and allow an improved understanding of color perception and its correlation with clinical aspects (13). color changes were characterized using the commission internationale de l’eclairage l*a*b* color space system (cie l*a*b*) which is one of the most popular and universally used system for dentistry and many authors used this system to evaluate the perceptibility of color differences (4,12-14). many authors had used δe* values to evaluate the perceptibility of color differences (18,19). however, it is noteworthy that the criteria for perceptibility used by each author were somewhat different. to overcome these differences and disagreements in the criteria, the national bureau of standards (nbs) system is frequently used to define the degree of color difference (δ e* value) according to the clinical significance (9,14,15). water absorption, absorption or adsorption of colorants from mouthwashes may be the causes of color changes of aesthetic archwires that is in agreement with other findings (17-19). moreover, color changes of aesthetic archwires may be related to presence of alcohol and ph level of the tested mouthwashes, it was found that low ph level and high alcohol concentration of mouthwashes may affect the surface integrity by softening the coating material and cause discoloration, this comes in agreement with other researches (20,21). in conclusion; although all brands of aesthetic archwires showed color changes at variable degrees but most of these changes were not visible or clinically acceptable. references 1. russell js. current products and practice: aesthetic orthodontic brackets. j orthod 2005; 32(2): 146-63. 2. kaphoor aa, sundareswaran s. aesthetic nickel titanium wireshow much do they deliver? eur j orthod 2012; 34(5): 603-9. 3. aksakalli s, malkoc s. aesthetic orthodontic arch wires: literature review. j orthod res 2013; 1(1): 24. 4. da silva dl, mattos ct, de araujo mv, de oliveira ruellas ac. color stability and fluorescence of different orthodontic aesthetic arch wires. angle orthod 2013; 83: 127-32. 5. akin m, ileri z, aksakallı s, basçiftçi fa. mechanical properties of different aesthetic arch wires. turk j orthod 2014; 27(2): 85-9. 6. arango s, peláez-vargas a, garcía c. coating and surface treatments on orthodontic metallic materials. coatings 2013; 3(1): 1-15 . 7. elayyan f, silikas n, bearn d. ex vivo surface and mechanical properties of coated orthodontic arch wires. eur j orthod 2008; 30(6): 661-7. 8. faltermeier a, rosentritt m, reicheneder c, behr m. discoloration of orthodontic adhesives caused by food dyes and ultraviolet light. eur j orthod 2008; 30: 89-93. j bagh college dentistry vol. 29(3), september 2017 color stability of pedodontics, orthodontics and preventive dentistry 105 9. mohammed i. evaluation and comparison of color stability and fluorescence of recent high aesthetic arch wies: an in vitro study under spectrophotometer and flourscence lamp. a master thesis, navodaya dental college and hospital, raichur, karntaka. 2013. 10. noori zt, ghaib nh. color stability of different aesthetic arch wires: an in vitro study. j bagh coll dentistry 2016; 28(1): 164-8. 11. razavish, ahmadizenouz g, gholinia h, jafari m. evaluation of the effects of different mouth rinses on the color stability of one type of glass ionomer, compomer and giomer. j dent mater tech 2016; 5(1): 36-42. 12. commission internationale de i’ecleirage (cie).colorimetry technical report. cie publication nu 15. 3rd ed. vienna, austria: bureau central de la cie; 2004 . 13. corciolani g. a study of dental color matching, color selection and color reproduction. ph.d. thesis, university of siena, school of dental medicine, italy, 2009. 14. inami t, tanimoto y, minami n, yamaguchi m, kasai k. color stability of laboratory glass-fiberreinforced plastics for aesthetic orthodontic wires. korean j orthod 2015; 45(3): 130-5 . 15. filho hl, maia lh, araújo mv, eliast cn, ruellas ac. colour stability of aesthetic brackets: ceramic and plastic. aust orthod j 2013; 29: 13-20 . 16. de oliveira cb, maia lg, santos-pinto a, gandini junior lg. in vitro study of color stability of polycrystalline and monocrystalline ceramic brackets. dental press j orthod 2014; 19(4): 114-21 . 17. lepri cp, ribeiro m, dibb a, palma-dibb rg. influence of mouth rinse solutions on the color stability and microhardness of a composite resin. int j esthet dent. 2014; 9: 236-44 . 18. noie f, o’keefe kl, powers jm. color stability of resin cements after accelerated aging. int j prosthodont 1995; 8: 51-5 . 19. dietschi d, campanile g, holz j, meyer jm. comparison of the color stability of ten new generation composites: an in vitro study. dent mater 1994; 10(6): 353-62. 20. villalta p, lu h, okte z, garcia-godoy f, powers jm. effects of staining and bleaching on color change of dental composite resins. j prosthet dent 2006; 95: 137-42 . 21. asmussen e. softening of bisgma-based polymers by ethanol and by organic acids of plaque. scand j dent res 1984; 92: 257-61 . الخالصة إن األستقرار اللوني .لمطالب المرضىتلبيةً واسع نطاق علىعلى أجهزة تقويم األسنان التجميلية ,أُستُخدمت أسالك التقويم التجميلية نتيجة الطلب المتزايد الخلفیة: من مختلفة نوا أل ياالستقراراللون لتقييم ت هذه الدراسةصمم .ألسالك التقويم التجميلية مهم سريرياً, فأي تصبغ أوتغير لوني سيؤثر على رضا وقناعة المريض غسوالت الفم. من مختلفة أنوا فيها غمر بعدأسالك التقويم التجميلية (danyوالمغلفة بالتفلون g&h)و (orthotechnologyالمغلفة باأليبوكسي :أربع ماركات من أسالك النيكل تيتانيوم التجميلية المغلفة تقييمتم : رقالموادوالط وقد أجريت قياسات حول(غسوالت الفم )ليسترين مع الكحول و ليستيرين بدون ك بعد أسبو واحد وثالثة أسابيع ثم ستة اسابيع من الغمر في نوعين من (hubitو .وفقاً للمنظمة العالمية لألضاءة (vita easyshade compactجهاز فحص الطيف اللوني )التغير اللوني بأستخدام بيئات الغمر.من مختلفأسالك التقويم التجميلية في وجود أختالفات معنوية كبيرة في قيم التغير اللوني بين جميع ماركات أظهرت نتائج هذه الدراسة لقد النتائج: خالل فترة الغمر ألسبو واحد في الماء orthotechnology)وشركة ) (dany)الجانب االخر, ُوِجد أختالف معنوي بين أسالك التقويم التجميلية لشركة . لتغير اللوني تزداد بزيادة فترة الغمرإن قيمة اكما ألسالك التقويم التجميليةوقد أنتج غسول الفم ليستيرين مع الكحول تغيرات لونية أكثر المقطر .مقبولة سريرياً أوهذه التغيرات كانت غير مرئية معظمأسالك التقويم التجميلية تغيرات لونية بدرجات مختلفة ولكن ماركات أظهرت جميع االستنتاجات: سالك التقويم التجميلية ,غسول الفم.أ األستقرار اللوني, :المفتاحیة الكلمات 29. sulafa f.doc j bagh college dentistry vol. 25(1), march 2013 concentrations of 176orthodontics, pedodontics and preventive dentistry concentrations of selected elements in permanent teeth and enamel among a group of adolescent girls in relation to severity of caries shahba’a m. al-jorrani, b.d.s. (1) sulafa k. elsamarrai, b.d.s., m.sc., ph.d. (2) abstract background: human teeth considered to be an important etiological host factor in relation to dental caries through its morphology and composition. elements may incorporate in tooth structure during pre and post-eruptive period changing the resistance for caries. the aims of this study were to determine the concentration of selected major (calcium and phosphorus) and trace elements (ferrous iron, nickel, chromium and aluminum) in permanent teeth and enamel among a group of adolescent girls in relation to severity of dental caries material and methods: the study group consisted of 25 girls with an age of 13-15 years old referred by orthodontists for extractions of upper first premolars (two sides). tooth and enamel samples were prepared for chemical analysis according to method described by lappalainen and knuttila (1979). dental caries was diagnosed by both clinical and radiographical examinations following the criteria of d1-4mfs index described by muhlemann (1976). all data were analyzed using spss version 19. results: the concentration of major elements in teeth and enamel (measured in % of dry weight) showed that ca ions were higher than p ions. on the other hand the concentration of trace elements in teeth and enamel samples (measured in ppm) showed that al ions was the highest followed by ferrous fe then ni ions, while cr ions were the least in concentration. all elements showed statistically highly significant difference in concentration between teeth and enamel samples. ca/p ratio was higher in enamel than tooth, but the difference was statistically not significant. major elements (calcium and phosphorus) in tooth and enamel samples recorded negative correlations with dmfs. trace elements except chromium ions recorded positive correlations with dmfs. they were not significant except for nickel ions in tooth and aluminum ions in enamel. conclusions: the presence of these elements in both teeth and enamel samples indicated that these elements present in our environment; as foods, water, and air so they incorporate through out the tooth layers during the preeruptive period of tooth development, and incorporate the outer enamel surface during the demineralization and remineralization processes that occurs in the post-eruptive periods. ca and p ions play an important role in mineralization of tooth and enamel. cr ions may play a role in improving mineralization and crystallity of teeth, while fe, ni and al may act as cariogenic elements. key words: trace elements, permanent teeth and enamel, caries severity. (j bagh coll dentistry 2013; 25(1):176-180). introduction the tooth is considered to be the most etiological host factor in relation to dental caries through its morphological characteristics and composition, so chemical analysis of teeth for their major and trace elements may allow understanding of the increase and decrease in their susptability to dental caries (1, 2). incorporation of trace elements during mineralization has been recorded to affect the resistance to dental caries (3, 4). fluoride was reported to decrease dental caries, while the role of other trace element in the prevention of the disease is not well substantiated. several studies in iraq were conducted concerning chemical constitution of teeth in relation to dental caries and a controversy was reported (57) . for all of the above and in order to increase the knowledge about the inorganic elements and dental caries etiology, this study was designed. (1) m.sc. student. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad (2) professor. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad materials and methods patients involved in this study were those referred by orthodontists for extractions of upper first premolars (two sides). the total number of patients was 25 girls with an age rang of 13-15 years, recorded according to the last birthday (8). examinations were carried out in the specialized dental center in al-sader city and the specialized center for prosthodontic and orthodontic treatment in al-qaira in baghdad province under standarized conditions (8). dental caries was diagnosed by both clinical and radiographical examinations. the clinical examination of teeth surfaces was done by using dental mirror and sharp dental explorer. assessment and recording of caries experience was done by the application of (d1-4 mfs index for permanent teeth) (9). at the end of caries examination patient was anesthetized for extraction of the upper first premolars cited by the orthodontist. after extraction teeth were cleaned and polished firstly by pumice slurry and rubber cup using slow speed hand piece, then washed with de-ionized water. the right upper 1st premolar of each patient was j bagh college dentistry vol. 25(1), march 2013 concentrations of 177orthodontics, pedodontics and preventive dentistry prepared by separating the root from its crown using curbide fissure burs number 36/19, and then dentine was removed from enamel by diamond round burs number 1/18 (6).then the prepared enamel and the whole left upper 1st premolar were prepared for chemical analysis (10). tooth and enamel samples were dried at 105 ºc for 6-8 hours to a constant weight, then powdered using ceramic mortar and pestle. samples of 250 mg of tooth powder and enamel powder were dissolved in 2ml of concentrated hcl and 1ml of concentrated hno3. following dissolution of samples they were diluted with 5 ml de-ionized water then filtered by using of preweight filter (cinter silica filter). after filtering the volume was completed to reach a final of 25 ml. the filter was re-weighted again following dryness and the final weight of the dissolved tooth powder was determined. chemical analysis was carried out at poisoning consultation center, medical city. calcium, aluminum, nickel and chromium ions were determined using air-acetylene atomic absorption spectrophotometer (aas) using standardized procedure by air-acetylene, while inorganic phosphorus and iron were determined colormetrically by using chemical kits. spss version 19 (statistical package for social sciences) was used for statistical analysis. descriptive measurement (mean and standard deviation) were used to describe variables. student's t-test was used to test the statistical significance of difference in mean of elements, concentrations between tooth and enamel samples. the statistical significance, directions and strength of linear correlation between the concentration of element in each sample and values of d1-4mfs index was measured by person's correlation coefficient. multiple linear regressions between dependant variable (dental caries) and independent variable (concentration of elements) were applied. p value equal to or less than 0.05 level of significance (p ≤ 0.05) was considered to be statistically significant, p value equal to or less than 0.01 level of significance (p ≤ 0.01) was considered to be statistically highly significant. the confidence limit was accepted at 95%. results decayed, missed and filled teeth surfaces of girls by fractions of d1-4mfs index were represented by their means and standard deviation (sd) in table (1). clinical and radiographical examinations showed that all subjects were affected by dental caries. the decayed surfaces (ds) contributed the major parts of this index followed by filled surfaces (fs) then missed surfaces because of caries (ms). grade (2) of lesion severity was the highest one, while the frank cavitation; grade (4) was the lowest one. table (2) illustrates the concentration of elements in teeth and enamel samples (mean ± sd) with statistical differences between them. the concentration of major elements in teeth and enamel (measured in % of dry weight) showed that ca ions were higher than p ions. on the other hand the concentration of trace elements in teeth and enamel samples (measured in ppm) showed that al ions was the highest followed by ferrous fe then ni ions, while cr ions were the least in concentration. all elements showed statistically highly significant difference in concentration between teeth and enamel samples. ca/p ratio was higher in enamel than tooth, but the difference was statistically not significant. pearson's correlations coefficient between cariesexperience and elements concentration in teeth are seen in table (3). negative, weak and statistically not significant correlations were recorded between major elements (ca and p ions) in teeth samples and dmfs. regarding trace elements in teeth sample al ions recorded a positive, weak and statistically highly significant correlation with d3 (p= 0.01); on the other hand ni ions recorded a positive, weak and statistically significant correlation with dmfs (p=0.05). generally the correlations between other elements (major and trace elements) measured in the teeth in addition to ca/p ratio with cariesexperience were all statistically not significant where as some of them showed positive correlations, while others showed negative correlations. table (4) illustrates the correlation coefficient between elements (major and trace) in enamel with caries-experience. major elements in enamel samples showed a negative, weak and statistically significant correlation between p ions and dmfs (p= 0.05), while statistically not significant correlation was seen with ca ions. for trace element al ions recorded a positive, strong and statistically highly significant correlation with dmfs (p 0.01), al ions also showed a positive, weak and statistically significant correlation with d1 (p= 0.01). while other elements (major and trace elements) measured in enamel in addition to ca/p ratio in enamel recorded statistically not significant correlation with cariesexperience. table (5) illustrates the result of mlr for dmfs surfaces (dependent variable) explained by elements measured in teeth samples (independent variables). a complete correlation coefficient of 0.565 was recorded between the dmfs and all factors entered. the r2 value of 0.320 was recorded indicated that 32 % of changes occurred j bagh college dentistry vol. 25(1), march 2013 concentrations of 178orthodontics, pedodontics and preventive dentistry in dmfs were explained by inorganic composition of teeth. for major elements the highest betacorrelation was recorded for ca/p ratio followed by p then ca. for trace elements the highest beta-coefficient was recorded for ni ions followed by cr then al and finally fe ions. no one of these betacoefficients was recorded to be statistically significant (p 0.05). table (6) illustrates the result of mlr for the dmfs (dependant variable) explained by elements measured in enamel samples. a complete correlation coefficient of 0.754 was recorded between dmfs and all factors. the r2 value of 0.569 was recorded indicated that 56.9 % of changes occurred in dmfs were explained by the inorganic composition of enamel. for major elements betacoefficient recorded for ca ions was the highest followed by that recorded for ca/p ratio and finally for p ions. for trace elements al ions recorded the highest betacoefficient followed by ni then fe and finally for cr ions. betacoefficient for al ions was highly significant (p 0.01), while other beta coefficients were recorded to be not significant (p 0.05). discussions different types of elements may incorporate in preeruptive and post-eruptive stages of tooth development, changing the resistance against dental caries (11, 12). incorporation of elements through layers of enamel and dentine may affect the rate of progression of dental caries, while incorporation of others following eruption involve the outer enamel surface, may affect initiation of dental caries. for this reason dental caries by grades of lesion severity was explored by the present studied. the d1-4mfs index was applied, as d1 and d2 fractions indicated that lesion is in the outer enamel surface, which may or may not progress in the deeper layers of tooth, while d3 and d4 fractions indicated that caries was already progressed to the deeper tooth layer. according to the results of this study the concentration of ca ions in both tooth and enamel samples were higher than p ions. this was true since these two ions are the major elements of the inorganic composition of tooth that form the apatite crystals with chemical formula [ca10 (po4)6 (oh) 2] (13, 14). the ca/p ratio of both tooth and enamel samples was lower than that of pure synthetic hydroxy apatite crystals that is 2.15 indicating the incorporation of other elements that replacing ca ions of these crystals resulting in new type of crystals. ca/p ratio of enamel was found to be higher than that of teeth, this result seems to be true since the inorganic constituents of enamel are higher than that of dentine that form the main bulk of tooth (15, 16). the presence of these elements in teeth samples indicating their incorporation through out the tooth layers during the pre-eruptive period of tooth development, on the other hand their presence in enamel may give an indication that there may be a continues incorporation of these elements in the outer enamel surface during the demineralization and remineralization processes that occurs in the posteruptive periods. the presence of these trace elements in both teeth and enamel samples give us an idea that these elements present in our environment; as they present in foods as (meats, potatoes, cheeses, whole-grain breads and cereals, fresh fruits and vegetables, chicken, eggs, milk, nuts, dried beans and peas). these elements could also be found in water that used for drinking or cooking foods and in air as pollutant as for cr vi that presents in air due to erosion of chromium containing rocks and nickel that presents in cigarettes (17, 18, 19) that may inhale by those group as passive smokers. although statistically not significant, inverse correlations were recorded between cariesexperience (dmfs) and major elements (ca and p) in tooth sample, this could indicate the important role of these elements in mineralization process of teeth. the same results were seen for enamel, but with statistically significant correlation between p ions and dmfs. from all of the trace elements studied only cr ions showed negative correlations with dmfs in both tooth and enamel samples, so it may have a role in improving resistance of teeth against caries; however these correlations were statistically not significant. for the other trace elements positive correlations were recorded with caries-experience (dmfs) in tooth and enamel. although they were statistically not significant, except for ni in teeth and al in enamel, these positive correlations may indicate that these elements affect composition and crystallity of dental hard tissue in a way favoring an increase in dental caries. regarding grads of lesion severity, most of elements showed weak and statistically not significant correlations, with variation in direction of these correlations, except al ions which recorded positive and statistically significant correlation with d3 in teeth samples and with d1 in enamel samples, indicating that this ion may have a role in both initiation and progression of dental caries. the impact of major and trace elements on dental caries seems to be much more in enamel compared to the whole tooth, as results recorded a value of r2 equal to 0.569 in enamel j bagh college dentistry vol. 25(1), march 2013 concentrations of 179orthodontics, pedodontics and preventive dentistry compared to only 0.320 in tooth, indicating that 56.9 % of changes occurred in dmfs were explained by inorganic composition of enamel, while the inorganic composition of the whole teeth explain only 32% of changes occurred in dental caries. this result gives an idea about the important role of composition and crystallity of enamel in the initiation of caries. references 1. baelum d, edwina k, bente n, vibeke s. dental caries and its clinical management. 2nd ed. oxford, blackwell munksgaard, 2008. 2. peter s. essentials of preventive and community dentistry. 3rd ed. arya (medi) publishing house; 2008. 3. fejerskov o. and kidd e. dental caries: the disease and its clinical management. 2nd ed. black well munksgaard; 2008. 4. moya k. and mason f. vitamins and minerals. new york publishing house, 2011. 5. el-samarrai s. major and trace elements contents of permanent teeth and saliva, among a group of adolescents, in relation to dental caries, gingivitis and mutans streptococci (in vitro and in vivo study). ph.d thesis, college of dentistry, baghdad university, 2001. 6. al-ani h. concentration of major and trace element in permanent teeth and enamel among (11-14) years old children in relation to dental caries. m. sc thesis, college of dentistry, baghdad university, 2005 7. al-ani r. molybdenum level in permanent teeth, enamel and saliva among a group of adolescents, in relation to dental caries and gingivitis and its effect on solubility and micro-hardness. ph.d thesis, college of dentistry, baghdad university, 2007. 8. who. oral health surveys. basic methods. 4th geneva, 1997. 9. muhlemann h. introduction to oral preventive medicine. quintessenze 1976. 10. lappalainen r. and kunuttila m. the distribution and accumulation of cd, zn, pb, cu, co, ni and k in human teeth from five different geological areas of finland. arch oral biol 1979; 24(5): 363-8. 11. demetrescu i, luca r, ionita d, prodana m. evaluation of heavy metals of temporary teeth from areas with different pollution level. indian j dental research 2010; 523(1): 73-81. 12. arun k. mode of action and toxicity of trace elements. john wiley and sons; 2008. 13. robert m, kliegmin s, karen j, marcdante a, hal b, jenson n. essentials of pediatrics. 5th ed. philadelphia: 2006. 14. fejerskov o. and kidd e. dental caries: the disease and its clinical management. 2nd ed. blackwell munksgaard; 2008. 15. chen c, gopalan g. calcium. in: dawson r, tontisirin k (ed). human vitamins and mineral requirement. mahicol university. nakhon panthmo; 2008. 16. jane h, victoria j. evidencebased approach to vitamins and minerals: health benefits and intake recommendations. 2nd ed. triltsch, melissa parsons, 2011. 17. maurice e, moshe s, catharine c, robert c. modern nutrition in health and disease. 10th ed. lippincott williams and wilkins, 2006. 18. vincent j. the nutritional biochemistry of chromium (iii). 1st ed. elsevier science ltd, 2007. 19. ehrenreich b. nickel and dimed. a holt paperback. new york, 2011. table 1: caries – experience of permanent teeth (d1-4mfs) among patients. fractions mean ± sd ds 4.44 ± 2.48 ms 1.60 ± 2.78 fs 2.60 ± 2.60 dmfs 8.64 ± 4.06 d1 0.84 ± 0.68 d2 1.76 ± 0.87 d3 1.20 ± 0.95 d4 0.64 ± 1.11 table 2: concentration of elements in teeth and enamel samples (mean ±sd) with statistical differences between teeth and enamel samples elements tooth enamel tvalue probability mean ± sd mean ± sd major elements in % of dry weight ca 21.56 ± 1.34 19.59 ± 1.32 5.215* 0.000 p 11.90 ± 1.17 10.31 ± 2.00 4.946* 0.000 ca/p 1.82 ± 0.19 1.91 ± 0.23 1.527 0.133 trace elements in ppm fe 8.40 ± 2.99 6.20 ± 2.24 2.936* 0.005 ni 12.47 ± 1.93 8.77 ± 1.26 7.984* 0.000 al 63.76 ± 22.56 25.60 ± 11.2 7.573* 0.000 cr 0.29 ± 0.03 0.17 ± 0.02 14.503* 0.000 j bagh college dentistry vol. 25(1), march 2013 concentrations of 180orthodontics, pedodontics and preventive dentistry table 3: correlation coefficients between elements in teeth and cariesexperience elements d1 d2 d3 d4 ds fs dmfs r p r p r p r p r p r p r p m ajor ca 0.09 0.67 0.10 0.63 0.08 0.69 0.09 0.66 0.00 0.99 0.03 0.88 0.09 0.64 p 0.24 0.23 0.09 0.64 0.07 0.74 0.22 0.28 0.02 0.91 0.19 0.36 0.29 0.15 ca/ p 0.29 0.14 0.05 0.79 0.88 0.67 0.16 0.41 0.01 0.96 0.16 0.44 0.24 0.23 t race fe 0.16 0.43 0.09 0.65 0.16 0.43 0.03 0.88 0.06 0.76 0.05 0.78 0.05 0.80 al 0.25 0.21 0.06 0.74 0.46** 0.01 0.02 0.90 0.28 0.16 0.23 0.25 0.28 0.16 ni 0.02 0.91 0.05 0.80 0.09 0.64 0.25 0.22 0.17 0.40 0.22 0.29 0.40* 0.05 cr 0.02 0.89 0.02 0.89 0.32 0.11 0.03 0.85 0.14 0.50 0.09 0.65 0.07 0.73 table 4: correlation coefficients between elements in enamel and cariesexperience elements d1 d2 d3 d4 ds fs dmfs r p r p r p r p r p r p r p m ajor ca 0.10 0.63 0.33 0.10 0.12 0.53 0.24 0.23 0.20 0.31 0.32 0.11 0.29 0.15 p 0.16 0.43 0.08 0.68 0.01 0.94 0.18 0.37 0.01 0.95 0.28 0.17 0.4* 0.05 ca/p 0.26 0.19 0.23 0.26 0.06 0.76 0.05 0.81 0.11 0.57 0.09 0.65 0.13 0.53 t race fe 0.07 0.72 0.08 0.69 0.31 0.12 0.25 0.21 0.28 0.16 0.09 0.63 0.20 0.31 al 0.44** 0.01 0.01 0.96 0.15 0.44 0.15 0.46 0.24 0.23 0.17 0.39 0.56** 0.003 ni 0.30 0.14 0.02 0.92 0.03 0.86 0.10 0.62 0.10 0.60 0.12 0.55 0.14 0.48 cr 0.29 0.14 0.15 0.46 0.11 0.59 0.10 0.62 0.22 0.27 0.01 0.63 0.15 0.45 table 5: multiple linear regressions (mlr) between elements in teeth and dmfs elements b (slope) std. error beta t pvalue m ajor ca 4.214 3.292 -1.393 1.280 0.218 p 6.946 6.041 2.004 1.150 0.266 ca/p 53.571 41.087 2.544 1.304 0.210 t race fe 0.106 0.285 0.078 0.371 0.715 al 0.022 0.042 0.120 0.510 0.617 ni 0.583 0.485 0.278 1.201 0.242 cr 15.955 31.449 0.122 0.507 0.618 r= 0.565 r2= 0.320 table 6: multiple linear regressions (mlr) between elements in enamel and dmfs elements b (slope) std. error beta t pvalue m ajor ca 0.680 1.418 0.223 0.480 0.638 p 4.342 2.852 1.174 -1.522 0.146 ca/p 18.294 14.968 1.034 -1.222 0.238 t race fe 0.012 0.371 0.007 0.033 0.974 al 0.197 0.060 0.545 3.276 0.004 ni 0.464 0.597 0.145 0.777 0.448 cr -7.337 31.591 0.043 0.232 0.819 r= 0.754 r2= 0.569 hiba f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 53 immunohistochemical expression of d2-40, vegf and pcna as biological markers of lymphangiogenesis, angiogenesis and proliferation in pleomorphic adenoma of salivary gland origin hiba jasim rassol, b.d.s. (1) kadhim al-soudani, b.d.s, m.sc. (2) abstract background: pleomorphic adenoma is the most common benign salivary gland tumor and shows a pronounced morphological complexity and diversity; for this the immunoprofiles and clinical course of pa differed according to cellular differentiation. therefore, it is important to assess potential biomarkers in diagnostic and therapeutic trials. this study evaluates the immunohistochemical expression of d2-40, vegf and pcna as markers of lymphangiogenesis, angiogenesis and proliferation of pa and their correlation with clinicpathological parameters and with each other. materials and methods: twenty five formalin – fixed, paraffin – embedded tissue blocks were included in this study. after histopathological reassessment of haematoxylin & eosin stained sections for each block, an immunohistochemical staining was performed using anti d2-40, anti vegf and anti pcna monoclonal antibodies. results: positive immunohistochemical of d2-40, vegf and pcna was found in (100%), (92%) and (88%) of the cases respectively. no statistically significant correlation neither among the markers immunoexpression nor with the clinicopathological finding, except a statistical significant correlation was found between (d2-40andvegf) expression with the histopathological presentation of the cases. conclusion: d2-40, vegf and pcna immunoexpression showed significant correlation with respect to the histopathological presentation of the cases. while no significant correlation seen regarding the expression of aforementioned markers with each other, suggests that each marker might affect on tumor behavior independently. keywords: pleomorphic adenoma, d2-40, vegf, pcna. (j bagh coll dentistry 2013; 25(special issue 1):53-58). introduction pleomorphic adenoma (pa) is a common benign salivary gland neoplasm characterized by neoplastic proliferation of parenchymatous glandular cells along with myoepithelial components (1). blood and lymphatic vascular systems are very important for supplying cells with nutrients and oxygen and for removing excessive fluids, which are crucial tasks for hemodynamic maintenance; so is an important issue for cell nutrition not only in malignant but also in benign tumor (2-4). d2-40 is a novel monoclonal antibody to o-linked sialoglycoprotein that reacts with affixation – resistant epitope, 40 kd a sialoglycoprotein found on lymphatic endothelium, glandular myoepthelial cells, fetal testis and on the surface of testicular germ cell tumors (5). vascular endothelial growth factor (vegf) is a signal protein produced by cells that stimulates vasculogenesis and angiogenesis. it is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate active in angiogenesis, vasculogenesis and endothelial cell growth. induces endothelial cell proliferation, promotes cell migration, inhibits apoptosis (6,7) . (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. the expression of genes related to cell proliferation and oncogenesis seems to be associated with the prognosis of the pa. tissue growth depends on both the rate of cell proliferation and cell death. the increased ability of cells in pa to proliferate is suggesting a tendency of tumor toward recurrence and possible susceptibility of pa to malignant transformation (8). proliferating cell nuclear antigen, commonly known as pcna, is a protein that acts as a processivity factor for dna polymerase δ in eukaryotic cells. it achieves this processivity by encircling the dna, thus creating a topological link to the genome. it is an example of a dna clamp. in response to dna damage, this protein is ubiquitinated and is involved in the rad6dependent dna repair pathway (9). the biological knowledge of pa plays a crucial role in their diagnosis, treatment and prognosis .the evaluation of the expression of different proteins can reflect facts about the biology and behavior of this tumor. this study aimed to asses: • immunohistochemical expression of (d2-40), (vegf) and (pcna) as biological markers of lymphangiogenesis, angiogenesis and proliferation in pleomorphic adenoma of salivary glands. j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 54 • correlation of studied markers with clinicopathological finding of pleomorphic adenoma and with each other. materials and methods: twenty five formalin – fixed, paraffin – embedded tissue blocks were collected from labrotaries archives and included in this study. after histopathological reassessment of haematoxylin & eosin stained sections for each block. four micrometer thick sections were cut and mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies using anti d2-40, anti vegf and anti pcna monoclonal antibodies (abcam uk). abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit (catalog no. ab80436, cambridge, uk) was used. results the sample comprised 14 (56%) females and 11 (44%) males with a female/male ratio (1.27:1). the age range of the patients with pleomorphic adenoma was between (16 -59) years with a mean of (36.5600 ±12.51026). the majority of the cases 20 (80%) was located in parotid gland followed by palate 5 (20%) cases. histopathological classifying was performed for each case of pleomorphic adenoma as follows, cellular and classic types were represented in 10 (40%) of the studied cases for each, while stromal type was presented in 5 (20%) of the cases (table 1). d2-40 immunostaining revealed positive lymphatic vessels immunoreactivity in intratumoral lymphatic vessel density (ilvd) was recorded in 7 cases (28%) out of 25 with a mean of (0.7600±1.755942) whereas lymphatic endothelial cells that limited to peritumoral lymphatic vessel density (plvd) was recorded in 4 cases (16%) out of 25 with a mean of (1.0000±2.107131). (table 2 and figure1&2). myoepithelial cells showed d2-40 +v immunostaining in all studied cases (table 3 and figure 3&4). regarding immunohistochemical expression of vegf and pcna monoclonal antibodies, positive immunostaining was seen in 23 cases (92%) and 22 cases (88%) respectively (table 4 and figure5) (table 5 and figure 6) there was no significant statistical correlation neither among the markers immunoexpression nor with the clinicopathological finding, except a statistical significant correlation was found between (d2-40 and vegf) expression with the histopathological presentation of the cases (table 6&7). figure 1: photomicrograph shows d2-40 immunostaining positive lymphatic vessels in pa (arrow). (original magnification x 200) figure 2: photomicrograph shows d2-40 immunostaining-positive lymphatic vessel (arrow).the adjacent blood vessel is negative (original magnification x400) j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 55 figure 3: photomicrograph shows positive d2-40 immunostaining in myoepithelial cells (pa). (original magnification x200) figure 4: photomicrograph showing positive d2-40 immunostaining in myoepithelial cells (pa). (original magnification x200) figure 5: photomicrograph shows positive vegf immunostaining in duct like structure, myoepithelial cells and stromal cells of pa.(original magnification x100) figure 6: photomicrograph shows positive nuclear pcna immunostaining in epithelial/myoepithelial cells of pa. (original magnification x400) discussion concerning the epidemiological parameters, including age, sex, site, clinical presentation, studies showed variable results; these inconsistent findings among different studies could be credit with the fact that the current study and some of the others are not an epidemiological type of studies, therefore the limited number and the random selection of the cases according to what is available preclude for definitive clinical findings. assessment of d2-40 immunohistochemical expression: a) assessment of lymphatic vessel density (lvd): in this study d2-40 immunostaining revealed positive lymphatic vessels immunoreactivity in intratumoral lymphatic vessel density (ilvd) was recorded in 7 cases (28%) out of 25 with a mean of (0.7600±1.755942) whereas lymphatic endothelial cells that limited to peritumoral lymphatic vessel density (plvd) was recorded in 4 cases (16%) out of 25 with a mean of (1.0000±2.107131). b) assessment of d2-40 expression in tumor cells. a) assessment of d2-40 expression in myoepithelial cells: as it was expected, in this study when d2-40 was applied to demonstrate lymphatic vessels in pa cases, the myoepithelial cells showed positive expression to it in all the studied cases in the basal cells of glandular structures as well as in stellate/spindle cells in myxochondroid matrices. this is in agreement with many researches (9,1215). j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 56 b) assessment of d2-40 expression in epithelial cells: regarding epithelial cells, d2 40 immunostaining was not detected in this study. similar findings found by soares et al,(2007) who reported that neoplastic epithelial cells showed enhanced membranous positivity in carcinoma expa but not in pa without malignant transformation. from the above findings it is possible that no normal epithelial cells expressed d2-40 and to assume that d2-40 act as a good tumor marker in the differential diagnosis of certain carcinomas from their potential histologic mimics since the presence of morphological similarities between the cells of some neoplastic lesions and their normal or benign counterparts impose diagnostic difficulties (16, 12,17,18). regarding clinicopathological variables; the present study showed statistically non significant correlation were identified except a statistical significant correlation was found between d2-40 immunoexpression with histopathological presentation of the cases; however, no previous reports highlights this correlation. assessment of vegf expression: this study showed a positive expression to vegf antibody in 23 (92%) of the cases. this finding comes in accordance with the results of previous study performed by pammer et al. (19) who demonstrated vegf mrna and protein in (100%) of pa cases. the majority of the cases showed weak (32%) to moderate (48%) immunoreactivity, this could be confined to metabolically low rate of the tumor that maintain metabolic activity via an oxygen-independent process (20). as far as correlation of vegf expression with clinicopathological parameters of pa is concerned; the present study showed statistically non significant correlation were identified except a statistical significant correlation was found between vegf immunoexpression with histopathological presentation of the cases; however, no previous reports highlights this correlation. assessment of pcna expression: the current study, ihc results of 25 cases of pa revealed positive pcna expression in 22 (88%) of the cases, this findings is similar to other findings (21,22) who found positive pcna expressed in (78.9%) and (75%) of pa cases respectively. the current results for most cases showed a predominantly weak pcna labeling 10 (40%) or no labeling 3 (12%). this result agrees with the those of (23-26) who reported a predominance of weak expression of this protein in pa, could be attributed to the less aggressive behavior of pa and possibly may indicate a lower tendency of the studied cases toward recurrence and possible susceptibility of these lesions to malignant transformation. regarding clinicopathological variables; the present study showed statistically no significant difference neither among different age nor between males and females. similarly nonsignificant correlation was found between pcna expression and different tumor site, this is in accordance with the findings of two researches (27,28) . as far as the histolpathological aspect is concerned, the present study showed nonsignificant correlation in pcna expression scores among different tumor histopathological subtypes. the correlation between the biological markers in pa: among all the available studies reviewed, to the best of our knowledge, the present work is the first to study these biomarkers all together except several studies that assessed only one of the aforementioned markers (19,5,11,12) . there was non-significant statistical correlation neither among the markers immunoexpression nor with the clinicopathological finding, except a statistical significant correlation was found between (d2-40 and vegf) expression with histopathological presentation of the cases. this study reveals that of the aforementioned markers were positivity expression by most of the studied cases suggests that each of them may act independently of each other in influencing of the tumor behavior. references 1. eveson jw, kusafuka k, stenman g, et al. in: barnes l, eveson jw, reichart p, sidransky d, editors. pathology and genetics of head and neck tumors. lyon: iarc press; 2007: 2548. 2. reis-filho js, schmitt fc. lymphangiogenesis in tumors: what do we know? microsc res tech 2003; 60(2): 171–80. 3. choi ww, lewis mm, lawson d, et al. angiogenic and lymphangiogenic microvessel density in breast carcinoma: correlation with clinicopathologic parameters and vegf family gene expression. mod pathol 2005; 18: 143–52. 4. maby-el hajjami h, petrova tv. developmental and pathological lymphangiogenesis: from models to human disease. histochem cell biol 2008; 130(6):1063-78. 5. al-rawi nh, omar h, alkawas s. immunohistochemical analysis of p53 and bcl-2 in benign and malignant salivary glands tumors. j oral pathol med 2010; 39:48-55. 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25:1-4. 23. yang l, hashimura k, qin ch, shrestha zp, et al. immunoreactivity of proliferating cell nuclear antigen in salivary gland tumors: an assessment of growth potential. a pathol anat 1993; 86: 422: 81. 24. matturri l, lavezzi am, biondo b, mantovani m. cell kinetics of pleomorphic adenomas of the parotid gland. eur j cancer b oral oncol 1996; 32b:154– 57. 25. trendell-smith nj, oates j, crocker j. the evaluation of salivary gland tumors using proliferating cell nuclear antigen. j laryngo otol 1997; 111: 5515. 26. zhu q, white f h, tipe g l. the assessment of proliferating cell nuclear antigen (pcna) immunostaining in human benign and malignant epithelial lesions of the parotid gland. oral oncol 1997; 33:29-35. 27. daniele e, tralongo v, morello v, et al. pleomorphic adenoma and adenoid-cystic carcinoma of salivary glands: immunohistochemical assessment of proliferative activity in comparison with flowcytometric study. cell prolif 1996; 29(3): 15362. 28. da cruz perez de, de abreu alves f, et al. prognostic factors in head and neck adenoid cystic carcinoma. oral oncol 2006; 42(2):139-146. j bagh college dentistry vol. 25(special issue 1), june 2013 immunohistochemical oral diagnosis 58 table 1: clinicopathological characteristic of 25 pa cases age no. % 15-24 5 20 25-34 5 20 35-44 9 36 45-54 2 8 sex male 11 44 female 14 56 tumor site parotid 20 80 palate 5 20 histological type cellular 10 40 stromal 5 20 classic 10 40 table 2: labeling index of the ilvd, plvd, tlvd in 25 cases of pa n min. max. mean s.d. ilvd 25 0.00 6.00 0.7500 1.755942 plvd 25 0.00 8.00 1.0000 2.107131 tlvd 25 0.00 12.00 1.8000 3.329164 table 3: d2-40 expression scores in 25 cases of pa % no. of cases d2-40 expression 52 13 score 1 20 5 score 2 28 7 score 3 table 4: vegf expression scores in 25 cases of pa % no. of cases vegf expression 8 2 score 0 32 8 score1 48 12 score2 12 3 score3 table 5: pcna expression scores in 25 cases of pa: % no. of cases pcna expression 12 3 score 0 40 10 score1 40 10 score2 8 2 score3 table 6: correlation between d2-40 and tumor histopathological subtypes in pa sig. x total histopathological subtypes d2-40 scores % n classic type of pa stromal type of pa cellular type of pa 0.01 8.231 52.0 13 70.0% 7 100% 5 10.0% 1 score1 20.0 5 30.0% 3 0.0% 0 20.0% 2 score2 28.0 7 0.0% 0 0.0% 0 70.0% 7 score3 100 % 25 100.0% 10 100% 5 100.0% 10 total table 7: correlation between vegf and tumor sites in pa sig. χ total histopathogical subtypes vegf scores % n classic type of pa stromal type of pa cellular type of pa 0. 012 16.354 8.0 2 20.0% 2 0.0% 0 0.0% 0 score0 32.0 8 10.0% 1 100% 5 20.0% 2 score1 48.0 12 60.0% 6 0.0% 0 60.0% 6 score2 12.0 3 10.0% 1 0.0% 0 20.0% 2 score3 100.0 25 100.0% 10 100% 5 100.0% 10 total j bagh college dentistry vol. 31(4), december 2019 flap and flapless 6 evaluation of crestal bone resorption around dental implants in flapped and flapless surgical techniques depending on cone beam ct scan (comparative study) mustafa abdul hussein al najjar b.d.s.(1) sahar shakir aladili b.d.s., m.sc.(2) abstract background: the long term survival of dental implants is evaluated by the amount of crestal bone loss around the implants. some initial loss of bone around dental implants is generally expected. there is reason to believe that reflecting a mucoperiosteal flap promotes crestal bone loss in the initial phase after an implant has been inserted. the surgical placement of a dental implant fixture is constantly changing and in recent years, there has been some interest in developing techniques that minimize the invasive nature of the procedure, with flapless implant surgery being advocated. the purpose of this study was to compare the radiographic level of the periimplant bone after implant placement between traditional flapped surgery and flapless approach depending on cbct during 24 weeks healing period. materials and methods: a total of 25 iraqi patients with an age range of 20-60 years who received 46 implants were randomly divided into two groups: a control group which involved 27 implants inserted by conventional flapped surgical approach and a study group which involved 19 implants inserted by flapless surgical approach. the bone level was measured by cbct for each implant at buccal and palata/lingual sides at two times, immediately after implant placement (base line data), and after 24 weeks healing period. results: there was no significant difference between study (flapless) and control (flapped) groups in the mean of total crestal bone resorption for buccal and palatal side after 24 weeks from implant placement (p= 0.393 for buccal side and p= 0.214 for palatal side). there was highly significant difference between buccal and palatal side regarding crestal bone loss around implants (p = 0.001) conclusions: bone resoption around dental implants placed with conventional flap surgery compared to flapless surgery does not seem to be influenced during the healing period before implant loading. (received: 16/2/2019; accepted: 17/3/2019) introduction osseointegrated dental implants are usually placed with a flap approach, which is based on soft tissue flap reflection and repositioning with suture after implant placement. this traditional approach has several drawbacks: decreased supraperiosteal blood supply due to flap elevation procedures, which can theoretically lead to bone loss; patient discomfort, which includes pain, bleeding, edema, and a longer surgical time (1, 2). the objective of modern implant treatment involves not only the successful osseointegration of the dental implant but furthermore an esthetic and functional restoration. the implant is required to be surrounded by stable peri-implant tissue levels that are in harmony with the existing dentition. stable bone levels at or close to the implant margin (shoulder) are among the factors used to consider implant treatment successful (3, 4). successful prosthetic reconstruction by dental implant mainly depends on the preservation of peri-implant bone (5, 6). in recent years, flapless surgery is increasingly becoming a routine clinical procedure, and has been reported to have a predictable outcome with high success rate. 1. baghdad health directorate – alrusafa, ministry of health. 2. assist. professor, department of oral and maxillofacial surgery, college of dentistry university of baghdad. corresponding author mustafa abdul hussein al najjar, mustafaalnajjar17@gmail.com this is facilitated by modern radiographic technologies and dental implant treatment planning software to perform three-dimensional evaluation of bone volume at anticipated implant sites (7). flapless surgery has several theoretical advantages. from a patient point of view, it shortens the surgical time, decreases discomfort by reducing swelling and pain and accelerates postsurgical healing. moreover, the blood vessels of hard and soft tissues around the implant site are preserved. some studies state that this less traumatic surgery implies reduced bone resorption (8). nevertheless, flapless surgery has some risks due to the limitations of exposure in the surgical site. a reported risk is buccal or lingual cortical plate perforation. therefore, the technique requires advanced clinical experience, and surgical judgement for appropriate case selection (patients with sufficient alveolar three dimensional bone and adequate keratinized gingiva) (9). several studies report on bone resorption and ridge alterations after implant placement in humans (10) and animals (11, 12). many studies in animals assess that leaving the periosteum in place with flapless implant surgery clearly decreases the bony resorption rate (13, 14), and according to some authors, the flapless procedure is superior to flap implant procedures for maintaining original mucosal shape surrounding implants (15). j bagh college dentistry vol. 31(4), december 2019 flap and flapless 7 therefore, it can be speculated that similar events may occur in humans after implant surgery. imaging may aid in evaluating implant therapy outcomes, such as peri implant bone defects and level and bone to implant interface (16, 17). recently, cone beam computed tomography (cbct) has been heavily marketed for implantbased oral rehabilitation procedures, mainly for treatment planning (18). nevertheless, some studies have used the method for assessment of the marginal peri-implant bone level and thickness, primarily of the buccal bone, and outcome of regenerative procedures (19, 20, 21). this study aimed to compare the radiographic level of the periimplant bone after implant placement between traditional flapped surgery and flapless approach depending on cbct during 24 weeks healing period. the working hypothesis is that using flapless technique decrease crestal bone resoption around dental implant. materials and methods this clinical randomized prospective study was conducted from december 2017 to november 2018, it included 25 iraqi patients who received 46 implants with an age range of 20-60 years. the patients were randomly divided into two groups: a control group which involved 27 implants inserted by conventional flapped surgical approach and study group which involved 19 implants inserted by flapless surgical approach. preoperative clinical and radiographic assessment were done for all patients. one implant system was utilized in the study (nucleoss co., turkey). inclusion criteria 1. patients had to be at least 18 years of age 2. implants to be placed at least 6 months after teeth extraction (healed sites). 3. only those patients who did not need any soft or hard tissue augmentation. 4. a minimum distance of 2 mm to adjacent anatomical structures (mandibular canal, maxillary sinus, mental foramen, and adjacent teeth). 5. the presence of attached non-mobile soft tissue at least 1.5 mm in thickness above the crest of bone in the area receiving the implant, as measured by reamer and stopper. 6. the presence of adequate bone width at least 5 mm, 3 mm apical to crest measured by bone caliper after measurement of soft tissue above the crest, no need for bone augmentation procedures. 7. patients with good oral hygiene. exclusion criteria 1. insufficient keratinized tissue above the implant site (less than 2 mm above the ridge crest). 2. insufficient bone width (less than 5 mm, 3 mm apical to crest). 3. presence of any pathological condition adjacent to proposed implant site or at the implant zone. 4. any medical conditions that could not withstand implant surgery or conditions that would interfere with normal healing mechanism including uncontrolled diabetes, osteoporosis, psychosis, current pregnancy at the time of surgical procedures. 5. heavy smokers (more than 20 cigarette per day) 6. patients with history of head and neck radiotherapy or chemotherapy over the past 5 years. 7. history or clinical evidence of para-functional habits such as bruxism and clenching. 8. patients with active periodontitis. 9. any dehiscence or fenestration of alveolar bone happened during the operation of implant placement. surgical procedures flap procedure (control group) after anaesthetization with lidocaine 2% by infiltration technique, a three sided flap (extensive flap design) or two sided flap was made initiated via paracrestal incision with palatal bias for better visibility, preserving a wider band of keratinized attached gingiva for more solid wound closure and avoiding wound dehiscence as seen in fig (1). full thickness mucoperiosteal flap reflection to expose crestal and buccal alveolar bone using periosteal elevator. the implant bed was prepared by the conventional drilling procedure. the predetermined dental implant size installed in its position. soft tissue closure was achieved with 3/0 black silk non absorbable suture (simple interrupted technique). j bagh college dentistry vol. 31(4), december 2019 flap and flapless 8 figure 1: placement of dental implants through the palatal bias incision flapless procedure (study group) after anaesthetization with lidocaine 2% by infiltration technique, the soft tissue punch was used with speed 400-600 rpm to remove the soft tissue and expose the bone in which the implant to be driven in as seen in fig (2). figure 2: mucosa was punched by tissue punch. the drilling procedure was started by pilot drill, fig. (3), then the parallelism and angulation of drilling holes checked with parallel pins, fig. (4) figure 3: drilling with pilot drill. figure 4: parallel pin to verify proposed implant angulation. followed by sequential stepped drilling until reaching the appropriate final drill size according to manufacturer instructions. the predetermined dental implant size installed in its position, fig. (5), and the margin of implant checked by periodontal probe to ensure that it was with the level of the surrounding bone followed by subjoining the cover screw into the fixture, fig. (6). then a single 3/0 black silk suture was used to preserve blood clot above the implant area. j bagh college dentistry vol. 31(4), december 2019 flap and flapless 9 figure 5: installation of dental implant in its position. figure 6: fixtures after placement in prepared sockets with cover screws. after six months the patients re-attended for second stage surgery and placement of healing abutments for about (10-14) days, fig. (7), then the patients were referred for prosthesis fabrication, fig. (8). figure 7: healing abutment connection after six months. figure 8: final prosthesis was fixed in patient's mouth. data collection and post-operative radiological assessment all patients in both surgical groups were informed to take cbct (time 1) in the same day or at the second day of surgery to assess the position of the implants within the bone; the relation of the implant/s to the other dentition, vital structures and the relation of the implant to the crestal bone level in 3 planes. data were collected first at the seventh day after surgery (first follow up). determination of bone level immediately that represents as base line data for each implant in both group on two sides, buccal side and palata/lingual side, firstly a vertical line was drawn at the center with the long axis of the dental implant passing through the notch of the cover screw which represent a reference point, then another horizontal line was drawn at the top of implant to determine its level with the crestal bone, also another two vertical lines along the buccal and palatal/lingual sides of implant were drawn where from these lines about 1mm the bone level was measured on each side of implant if the bone thickness was enough (such as implants placed in posterior area) or about 0.5 mm if the bone was thin (such as implants placed in anterior region), fig. (9 a) all the patients were investigated by cbct (time 2) after 24 weeks post-operatively with the same relations of (time 1), also assessment of osseointegration, survival and early failure rate with the aid of alberktson criteria of success (implant immobility, no peri-implant radiolucency, asymptomatic), and checking for any complication that may have occurred. determination of crestal bone level after 24 weeks was done with the same method in (time 1) and the difference was calculated which represented bone loss that was shown as a shadow in the area, fig. (9 b). in order to view the same j bagh college dentistry vol. 31(4), december 2019 flap and flapless 10 section in the cbct and to avoid any error that may affect the result in reading the section, the notch of the cover screw is used as a reference point. figure (9): cbct (oblique view) for the same posterior di placed with flapped procedure. (a) immediate post-operative cbct illustrating the buccal side bone level of di (arrows) in relation to the horizontal line. (b) 24 weeks post-operative cbct illustrating the difference in bone level (arrow) that presented as shadow. statistical analysis the data were analyzed using statistical package for social sciences (spss) version 25. the data presented as mean, standard deviation and ranges. categorical data presented by frequencies and percentages. independent t-test and analysis of variances (anova) (two tailed) was used to compare the continuous variables among study groups accordingly. z-test was used to evaluate the difference in proportions between flapped and flapless cases regarding survival rate. a level of p – value less than 0.05 was considered significant. results there was no significant difference between study (flapless) and control (flapped) groups in the mean of total crestal bone resorption for buccal and palatal sides after 24 weeks from implant placement (p= 0.393 for buccal side and p= 0.214 for palatal side), table (1). there was highly significant differences between buccal and palatal sides regarding crestal bone loss around implants measured by cbct after 24 weeks from implants placement for both flapped and flapless surgical techniques (p = 0.001), table (2). table 1: comparison according to total mean bone loss in buccal and palatal sides between two surgical groups. sides total bone loss in surgical groups p value flapped group mean ± sd flapless group mean ± sd buccal side 0.5 ± 0.43 0.39 ± 0.35 0.393 palatal side 0.13 ± 0.18 0.06 ± 0.14 0.214 values are expressed in mean ± sd table 2: comparison between total resorption of buccal and palatal sides group total bone loss of buccal and palatal sides p value buccal side mean ± sd palatal side mean ± sd flapped group 0.5 ± 0.43 0.13 ± 0.18 0.001 flapless group 0.39± 0.35 0.06 ± 0.14 0.001 values are expressed in mean ± sd discussion according to our data flapless surgery cannot fully avoid bone resoption this was true with all implants placed by flapless technique in this study as they were evaluated by cbct. this agree with a study done by nickenig et al. (2010) (22) , they found that the mean crestal bone loss of (0. 5 mm) for implants placed with flapless surgery after a healing period determined radiographicaly using digital panoramic radiographs. so it possible to say that gentle flap raising does not hamper bone healing around dental implants in humans. based on the results obtained from this study, the choice of type of surgical approach does not affect peri-implant bone resorption. our data on bone resoption are in line with the majority of data in the literature, lin et al. (2014) (23) reported no significant reduction of marginal bone resorption with flapless technique, also studies showed that crestal bone loss was comparable among implants placed either using flapped or flapless surgical technique (24, 25). the findings of this study disagree with tsoukaki et al. (2013) (8) who reported that no bone resoption around flapless implants and (job et al., j bagh college dentistry vol. 31(4), december 2019 flap and flapless 11 2008) (26) who reported a significantly lower resoption around implants in flapless group. in this study, there was significant difference between total mean of buccal and palatal aspects (p = 0.001) for both flapped and flapless group. there was obvious that bone resoption in buccal side much more than palatal / lingual side in both groups. also bone resoption in buccal side was a little higher in maxilla than mandible and anteriorly more than posteriorly for the flapped group, while for flapless group was nearly the same. the data from this study can be accounted for the following reasons: according to anterior maxilla the bone loss in buccal/facial side was higher than palatal side in both flapped and flapless groups, this may be related to the thinner facial plate that leading to more bone resoption after implant placement. this was supported by el nahass & naiem. (2015) (27), who reported that in the incisor region, the buccal bone plate around a tooth was thinner than 1 mm in 86% of the cases as demonstrated by computerized tomography. for posterior maxilla and mandible in flapless group also the bone loss was higher in buccal side than palatal/lingual side, there was no clear interpretation for this result but after evaluation of the buccal plates for implants placed with flapless procedures, we noticed that most of them were thinner than palatal/lingual plates, this may be either they were initially thin or implant were deviated slightly towards buccal side during placement which made them more thin. it however noteworthy that thin buccal plates lost more bone than thick buccal plates. the deviation of implants supported by a study done by van de velde et al. (2008)(28) performed an in vitro model study to analyze deviations in the position and inclination of implants placed with flapless surgery compared with the ideal, virtual planned position and they concluded that location of implants installed with a flapless approach differed significantly from the ideal position. the findings were supported or in line with a hypothesis reported by (teughels et al., 2009; merheb et al., 2015) (29) (30), stated that a thin buccal plate is less resistant to the different types of trauma an implant can endure and would therefore be more prone to resoption and buccal implant exposition. according to posterior maxilla and mandible in flapped group the buccal bone loss was higher than palatal/lingual bone, this may be related to the flap elevation during surgical procedure on the buccal side and subsequent trauma that occurred more buccally rather than palatal/ lingual sides where there was no flap elevation. this was supported and in accordance with the fundamental studies reported by merheb et al. 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31: 591-601. 25. de bruyn h, atashkadeh m, cosyn j, et al. clinical outcome and bone preservation of single tiunite implants installed with flapless or flap surgery. clin implant dent relat res 2011; 13: 175-183. 26. job s, bhat v, naidu em. in vivo evaluation of crestal bone heights following implant placement with'flapless' and'with-flap'techniques in sites of immediately loaded implants. indian j dent res. 2008; 1;19(4):320. 27. el nahass h, n. naiem s. analysis of the dimensions of the labial bone wall in the anterior maxilla: a cone‐ beam computed tomography study. clin. oral impl.res. 2015; 26(4):e57-61. 28. van de velde t, glor f, de bruyn h. a model study on flapless implant placement by clinicians with a different experience level in implant surgery. clin. oral impl.res. 2008; 19(1):66-72. 29. teughels w, merheb j, quirynen m. critical horizontal dimensions of interproximal and buccal bone around implants for optimal aesthetic outcomes: a systematic review. clin. oral impl.res. 2009; 20:134-45. 30. merhab j, vercruyssen m, couke w, beckers l, teughels w, quirynen m. the fate of buccal bone around dental implants. a 12-month postloading follow-up study. clin. oral impl. res. 00, 2015, 1-6. j bagh college dentistry vol. 31(4), december 2019 flap and flapless 13 الخالصة من خالل تقييم كمية فقدان العظم السنخي الحافي حول زراعة األسنان تعد بمثابة جذور االسنان االصطناعية حيث يتم تقييم بقائها على المدى الطويل خلفية الدراسة: ضع الجراحي لزراعة االسنان زرعة السن. هناك سبب لألعتقاد بأن رفع السدلة الجراحية يعزز من فقدان العظم في المراحل األولية بعد ادخال الغرسة. يتغير الو حة الالسديلة, أن استخدام بشكل مستمر وفي السنوات االخيرة كان هناك بعض االهتمام بتطوير التقنيات التي تقلل من طبيعة األجراء الجراحي مع تزايد عملية الجرا ن منصة الغرسة وبداية الغرسة مع العظم يمكن أن يكون مفيدا جدا التصوير الشعاعي المقطعي المخروطي لقياس حجم العظم حول الغرسات السنية واالرتفاع بي ومهما لمراقبة األنسجة العظمية للحفاظ على طول عمر الزرعة وجمالية األسنان االصطناعية المدعمة بالزرعات. ة( والجراحة )الالسديلة( اعتمادا على التصوير الشعاعي لمقارنة المستوى الشعاعي للعظم المحيط بالزرعة بين عملية الجراحة التقليدية )السديل أهداف الدراسة: أسبوع(. أيضا الجراء مقارنة عامة بين كل من التقنيات فيما يتعلق بمدة العملية الجراحية. 24المقطعي المخروطي خالل فترة الشفاء ) مريضا عراقيا 25وان ما مجموعه ,2018الى تشرين الثاني/نوفمبر 2017 أجريت هذه الدراسة االستباقية السريرية من كانون االول/ديسمبر المواد وأساليب العمل: سنة. فشلت عملية زرع واحدة في المجموعة الضابطة لذلك تم استبعادها من التحليل االحصائي بأستثناء تحليل 60و 20عملية زرع تتراوح اعمارهم بين 47مع عملية زرع يتم ادخال الزرعات عن طريق الجراحة 27ية في مجموعتين: المجموعة الضابطة التي تضمنت معدالت البقاء والفشل. تم اختيارالمرضى بصورة عشوائ عملية زرع تم ادخال الزرعات عن طريق الجراحة )الالسديلة( حيث تم اجراء تقييم سريري وشعاعي قبل الجراحة 19التقليدية )السديلة( ومجموعة الدراسة تضمنت , تركيا( nucleossء تقدير العظم السنخي لمجموعة الدراسة عن طريق التخطيط العظمي, تم استخدام نظام زرع واحد في الدراسة )شركةلجميع المرضى وتم اجرا carestream cs 8100 3d)وتم قياس مستوى العظم )الخسارة( ومدة العملية لكل زرعة. قياس مستوى العظم تم بواسطة التصوير الشعاعي المخروطي بجهاز health inc., france) ( 24في الجانب الخدي والجانب الحنكي مرتين لكل زرعة, فور وضع الزرعة وبعد فترة الشفاء .)اسبوع ( للجانب الخدي p= 0.393) لم يكن هناك فرق معنوي بين مجموعة الدراسة ومجموعة الضبط في متوسط اجمال فقدان العظم في الجانب الخدي والحنكي النتائج: قياسها ( للجانب الحنكي. كانت هناك فروق ذات داللة احصائية كبيرة بين الجانب الخدي والحنكي فيما يتعلق بفقدان العظم حول الزرعات التي تم p=0.214)و اعة السن في مجموعة (. وفقا لوقت العملية, استهلكت زر p=0.001) اسبوع من وضع الزرعات لكل من التقنيات الجراحية 24بواسطة التصوير الشعاعي بعد . p=0.001)) الدراسة حوالي ثلث الوقت الالزم لزراعة المجموعة الضابطة مع فرق كبير للغاية فاء قبل تحميل ال يبدو ان فقدان العظم حول الغرسات السنية الموضوعة بطريقة الجراحة )السديلة( مقارنة بالجراحة )الالسديلة( قد تاثر خالل فترة الش األستنتاجات: الزرعة. dropbox 7 nadia f 37-41.pdf simplify your life j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 17 in vitro the effect of canals instrumented with three rotary ni-ti systems on the dislocation resistanceo guttafusion® versus single cone obturation technique rafal s. ameen, b.d.s. (1) raghad a. al hashimi, b.d.s., m.sc., ph.d. (london, uk) (2) abstract background: complete seal of the root canal system following its chemo-mechanical debridement plays a pivotal role for achieving successful endodontic treatment. this can be established by reducing the gaps between the core filling material and root canal wall. aim: to assess and compare the dislocation resistance of root canals obturated with guttafusion® and totalfill bc sealer versus single cone obturation technique and totalfill bc sealer after instrumentation of the canals with waveone, protaper next and protaper universal system. material and method: sixty extracted human permanent mandibular premolars were conducted in the current study. the teeth were decorated and left the root with 15mm length; the roots were divided randomly into three main groups, twenty roots in each group. the roots were instrumented with different rotary systems using crown down technique according to the groups: (group i) was instrumented with waveone files. (group ii) was instrumented with protaper next system and (group iii) was instrumented with protaper universal system. for each group the same irrigation regimen was used, 3 ml of 5.25% sodium hypochlorite and 3 ml of 17% edta to remove the smear layer. then, group i was also subdivided randomly into two subgroups of ten samples each, (group i a) obturated with single cone gutta-percha and (group i b) filled with guttafusion®. group ii was divided into (group ii a) obturated with single cone gutta-percha and (group ii b) filled with guttafusion®. group iii was divided into (group iii a) obturated with single cone gutta-percha and (group iii b) obturated with guttafusion®. in the present study, totalfill bc sealer was used for all the tested groups. then, the roots were embedded in clear acrylic resin and each root sectioned into three sections of 2mm thick (apical, middle and coronal). the push-out bond strength values represented by (mpa) unit was calculated by dividing the load on the surface area and the last was measured in collaboration with autocad system software program. failure mode analysis was carried out to examine the type of failure in each sample by using a stereomicroscope. results: the results showed highly significant differences among the main groups that instrumented with different rotary systems (waveone, protaper next and protaper universal system). there were highly significant differences between the two obturation techniques of the subgroups (single cone gutta-percha versus guttafusion®). however; gutta-fusion® showed highest bond strength value than single cone obturation technique. the coronal third slices of all groups showed highest value of bond strength in comparison to the middle thirds and apical thirds. in the meantime, the middle third slices showed bond strength higher than that of the apical thirds for all groups. statistical analysis was performed by using two way anova and lsd tests. conclusions: the instrumentation techniques and the obturation materials significantly affected the push-out bond strength values of obturation system. the highest value was appointed in root canals instrumented with protaper universal system; obturated with guttafusion® and bc sealer, whereas, the lowest bond strength was appeared at canals instrumented with protaper next; obturated with single cone gutta-percha and bc sealer. keywords: bc sealer, guttafusion®, push-out bond, waveone system, protaper next, protaper universal. (j bagh coll dentistry 2017; 29(3):17-25) introduction three-dimensional seal of the root canal space is one of the fundamental goals of successful endodontic treatment, therefore various obturation materials and techniques were developed to fill root canal system and obliterate any voids or space within it in order to prevent reinfection of the tooth with bacteria and their by-product (1). in this study, three rotary systems were employed for preparation of the root canals including, waveone (reciprocation motion), protaper next (continuous rotation) and protaper universal (continuous rotation) due to its improved cutting efficiency and safety in comparison with stainless steel files (2). (1) master student, department of conservative dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. in addition, totalfill bc sealer was used for all the experimental groups since; it has been reported that the hydrophilic sealer uses moisture of the root space for completing setting reaction (3). moreover, this sealer was adapted perfectly to dentine and formation of a chemical bond with inorganic phase of dentine (4). in this study, half of the tested groups were obturated using single cone technique, which uses larger master cone that closely match the geometry of the last rotary niti files that used during instrumentation; thereby it is facilitating the root canal filling (5). nevertheless, guttapercha is not adhered to the root canal wall compromising the concept of three-dimensional seal, therefore; a nother obturation techniques have been introduced over the past decade to improve the seal of the root canal system. j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 18 however, a three-dimensional seal is important for reducing diseases associated with root canal treatment (6). thus, carrier based gutta-percha technique is an effective method for obturation of the rest prepared canal with a guttafusion® in which the core made from chains of crosslinked polymer of gutta-percha that coated with flowale gutta percha without need for metal or plastic core. the benefit of carrier is to condense gutta-percha which is heated by special devise to enhance its flow into the canal (7). so, half of the groups were obturated with guttafusion®. this study was designed to compare the push-out bond strength exhibited by root fillings performed with either guttafusion® and bc sealer or single cone gutta-percha and bc sealer after instrumentation of root canals with either waveone (wo) (reciprocating file) or protaper next and pro taper universal (rotation files). the null hypothesis stated that there is no effect of either instrumentation technique or obturation method on the push-out bond strength value. material and method sample selection sixty extracted human mandibular permanent premolars were selected from different health centers according to specific criteria. the age (1824 years) while the status of the pulp, gender and extraction reason were not being considered and the criteria for selection of teeth included the following: straight root canal, mature, patent, centrally located apical foramen and roots devoid of any resorptions (8, 9). sample preparation after extraction, all the teeth were stored in distilled water. afterward, sharp periodontal curette was used to remove remnants of soft tissue on the root surface and magnifying eye lens (10x) was used to verify the root surfaces and any visible cracks or fractures saw by using a light cure device (10). then, the teeth were decorated and left the root with 15mm length using diamond cut off saw with the use of the water coolant to minimize the formation of smear fig. 1 (11). then a size 10 kfile (dentsply, maillefer, switzerland) was used to ensure straight canal, patency and central position of apical foramina. the exact location of the apical foramen was determined by advancing the size 10 k-file into the canal until it was visualized at the apical foramen (10). then silicon rubber base impression material (heavy-body) was mixed according to manufacturer’s instructions (base and catalyst) and inserted inside the plastic containers, then the root was inserted in center of the heavy body to facilitate handling of the roots during instrumentation and obturation procedure (10). study design the selected teeth were randomly divided into the following 6 subgroups (n = 60): 1. group i a: waveone instrumentation (dentsply, maillefer, switzerland), followed by obturation using single cone gutta-percha (dentsply, maillefer, switzerland) and totalfill bc sealer (brasseler, savannah, usa). 2. group i b: waveone instrumentation (dentsply, maillefer, switzerland), followed by obturation using guttafusion® (vdw, germany) and totalfill bc sealer (brasseler, savannah, usa). 3. group ii a: protaper next instrumentation (dentsply, maillefer, switzerland) followed by obturation using single cone gutta-percha (dentsply, maillefer, switzerland) and totalfill bc sealer (brasseler, savannah, usa). 4. group ii b: protaper next instrumentation (dentsply, maillefer, switzerland) followed by obturation using guttafusion® (vdw, germany) and totalfill bc sealer (brasseler, savannah, usa). 5. group iii a: protaper universal instrumentation (dentsply, maillefer, switzerland) followed by obturation using single cone gutta-percha (dentsply, maillefer, switzerland) and totalfill bc sealer (brasseler, savannah, usa). 6. group iii b: protaper universal instrumentation (dentsply, maillefer, switzerland) followed by obturation using guttafusion® (vdw, germany) and totalfill bc sealer (brasseler, savannah, usa). root canal instrumentation 1. group i (a and b) waveone system instrumentation: (20sample) firstly, waveone primary file was connected to endo-motor (smart x) (densply, maillefer switzerland) to produce glide path for large wo file (black) which is 40\08 (12). the irrigation regimen which used for all groups was 3 ml of 5.25% naocl (cerkamed, poland). the smear layer was removed with 3 ml of 17% aqueous edta solution (dental produits dentaires sa, switzerland) for one minute and followed with a final flush with 3 ml of distilled water (9). 2. group ii (a and b) protaper next instrumentation: (20sample) the endo-motor x-smart (densply, maillefer switzerland) was worked at speed of 300 rpm and torque of 2.0 ncm with x1 20/04. then, x2 j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 19 25/06, x3 30/07, were used in same manner to provide glide path for x4 40/06 (12). 3. groups iii (a and b) protaper universal instrumentation (20sample) firstly, the canal was instrumented with (s1), 17/04 with endo-motor x-smart (densply, maillefer switzerland) which was operated at speed of 250 rpm and torque of 3.0 ncm then, (s2) 20/02 was used with speed of 250 rpm and torque of 1.0 ncm, while f1 20\ 07 was worked at speed of 250 rpm and torque of 1.5 ncm while f2 25\08, f3 30\09, f4 40\06 were used respectively at constant speed of 250 rpm and constant torque of 2.0 ncm (12). samples obturation: i.group i a, ii a, iii a obturation with single cone technique: the canal was dried with a corresponding paper point size # 40 (dentsply, maillefer, switzerland).at this time, the canal was ready for obturation with single cone obturation material(dentsply, maillefer, switzerland) and a totalfill sealer (brasseler, savannah, usa) that dispensed through its auto mix syringe tip into the coronal third of the root canal according to the manufacturer's instructions (8), afterwards a single cone gutta-perch size #40 was slowly inserted to full working length of the canal. for these groups (ia, iia and iii a) a heated plugger (medesey, italy) was used to remove the access gutta-percha out of the orifice of the canal (13). i. group i b, ii b, iii b obturation with guttafusion®: these groups were obturated with guttafusion® after drying the canal with a corresponding paper point size #40(dentsply, maillefer, switzerland) fig. 2. next, totalfill sealer (brasseler, savannah, usa) was dispensed through its automix syringe tip into the coronal third of the root canal according to the manufacturer's instructions and hand file size #15 coated with a thin layer of bc sealer dispensed on glass slab, then the file was lightly coat the canal wall with existing sealer. afterward, the holder of guttafusion® oven was raised to hold the guttafusion® obturator size # 40 then pushed down to start thermoplasticizing the obturator fig. 3. then the oven gave visual and acoustic warning signals which indicated that the obturator was ready to be used. afterward, the obturator was took out from the obturater holders which can be released easily by pushing it down and placed within the canal to the full working length. afterward, the obturator handle was bending to right and left until separation took place and then, core material condensated with plugger (14). then, the root was radiographed within their silicon rubber base mold to ensure adequate obturation, then moistened gauze with normal saline was wrapped each group. afterward, all samples were stored in an incubator for 7 days at 100% humidity and 37 oc to ensure complete setting of the sealer (15). teeth sectioning the samples were embedded in clear orthodontic resin after the period of storage (16). firstly, a cylinder mold with four holes was prepared from silicon material (oomoo® smooth-on, east texas), each hole has 25 mm depth and 10 mm width .in general, the width of the cylinder was 6 cm while, the depth of it was 25mm. the root was inserted in the base (center) of each hole with the aid of dental surveyor; however, the coronal surface of the root was fixed with sticky wax to the dental surveyor to ensure accurate and central placement of the root and perpendicular sectioning to the long axis of the roots. as recommended by the manufacturers, the acrylic was prepared by mixing powder and liquid. evaporation of monomer was prevented by covering the jar. afterward, the material was left for few minutes to reach the workable stage. afterward, the freshly prepared cold cure acrylic paste was loaded in cylinder hole and pushed with spatula to ensure that the acrylic sample was devoid from any void with complete coverage of the root with acrylic fig. 4 (17). then, after complete setting of the acrylic sample; it was removed from the cylinder hole and each sample was sectioned horizontally into 2 mm thick slices at each of the three-thirds (coronal, middle and apical) of the root using a diamond disc with continuous water flow to minimize smearing fig. 5 (11). push-out test after measuring of the apical side diameter of the slice, the cylindrical metal punch tip (either 0.4, 0.6 or 0.8 mm in diameter) was selected to cover as much as possible of the root filling, yet avoiding any contact with the canal walls (18). after placement of specimens on base, the load was applied by the punch in apico-coronal direction using a universal testing machine at speed 0.5mm/min fig. 6. the push-out bond strength value represented by (mpa) unit was calculated by dividing the load in newton on the surface area (mm2) that calculated in collaboration with auto cad system software program (19). afterward, a stereomicroscope examined the root canal wall of each samples at 25x magnification to determine the failure mode (20). bond strength mpa = debonding force (n)/ interfacial area mm2 j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 20 the interfacial area (mm2) was calculated by 0.5(circumference of coronal aspect + circumference of apical aspect) * thickness (21). analysis of failure modes stereomicroscope (hamilton, altay) was used to inspect a slice at 25x magnification to determine the failure mode. each sample was evaluated and placed into one of three failure modes (22) type i: adhesive failure, either at the sealer-dentin (s/d) or between the sealer-core (s/c) interfaces, type ii: cohesive failure, within the filling material (sealer or core material), type iii: mixed failure, which contains both adhesive and cohesive failures. figure 1: length of tooth was measured with a digital caliper figure 2: guttafusion® gutta-percha size # 40 & totalfill sealer figure 3: guttafusion® oven with guttafusion® after pressed its handle figure 4: central placement of the root with a cylinder hole figure 5: a. sectioning of the specimen, b. the specimen measured with digital caliper figure 6: universal testing machine results mean values and standard deviation for all groups are presented in (table 1). analysis of variance (anova) test was performed and showed that the highest and the lowest mean values of push-out bond strength were seen in (group iii b) at coronal third of root canal that instrumented with ptu system and filled with guttafusion® (5.017 mpa) and (group ii a) at apical level of canal filled with single cone guttapercha after its instrumented with ptn (1.645 mpa) respectively fig. 7. other mean values of the study groups were swing between these values. a b j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 21 analysis of variance (anova) test was preformed to compare between the obturation systems at each level and to identify if there is any statistically significant differences (regarding push-out bond strength) between two obturation systems within each level. highly significant differences (p≤0.01) were found at all levels and the results showed the followings: 1. anova test showed that among each site, there is highly significant effect of group, subgroup and interaction effect of group* subgroup on the variability of push-out bond strength with strong coefficient of determination was found in the coronal site. 2. it was found at each site, protaper universal system has the highest mean of push-out bond strength followed by waveone system. while, protaper next system showed the lowest push-out bond strength with highly significant difference among them (regarding instrumentation techniques). 3. there was a highly significant difference of subgroups that obturated with guttafusion® than single cone obturation material at all level regardless the instrumentation techniques. however, group i a (wo instrumentation, single cone obturation) showed highly significant difference than group ii a (ptn instrumentation, single cone obturation). while group i a (wo instrumentation, single cone obturation) showed no significant difference than group iii a (ptu instrumentation, single cone obturation). while, group i b(wo instrumentation, guttafusion® obturation) was showed no significant difference than group ii b (ptn instrumentation, guttafusion® obturation). while group iii b (ptu instrumentation, guttafusion® obturation) showed a highly significant difference than group i b and group ii b table 12. 4. there was a highly significant difference between all levels within all groups. the least significance difference test (lsd) was performed to evaluate the significant differences between each obturation system at each level and showed that: at each site and each subgroup; there is highly significant difference between groups except between (wo and ptu instrumentation with single cone obturation technique) and (wo and ptn instrumentation with gutafusion® obturation) however, the result was found to be statistically not significant. the coronal third slices of the groups showed a highest value of bond strength in comparison to the middle thirds and apical thirds. in the meantime, the middle third slices showed bond strength higher than the apical thirds for all groups (table 3) (fig. 7). figure 7: the mean value of push-out bond strength of two obturation systems the failure mode of the samples is presented in (table 4). in this study the predominant mode of failure for canal instrumented with different rotary system (wo, ptn, ptu system and obturated with single cone gutta percha) was adhesive failure mainly at dentine / sealer interface. in addition the same groups showed fewer mixed failures followed by cohesive failure mainly within sealer when compared to the other techniques. however, the predominant mode of failure for canal instrumented with previous rotary systems and obturated with gutta-fusion® was mixed failure followed by cohesive failures mainly within gutta-percha and then adhesive failure was less frequent at all the sections of all subgroups that obturated with guttafusion®. j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 22 table 1: descriptive statistics of push-out bond strength (mean, ±sd, max, min) of tooth sites by groups and subgroups. site group subgroup single cone (a) guttafusion® (b) total min. max. mean ±sd min. max. mean ±sd min. max. mean ±sd apical wo 1.87 2.80 2.46 0.30 3.30 4.26 3.61 0.29 1.87 4.26 3.03 .66 ptn 1.23 2.09 1.65 0.33 3.19 4.06 3.47 0.28 1.23 4.06 2.56 .98 ptu 1.74 2.65 2.22 0.33 4.22 5.20 4.51 0.30 1.74 5.20 3.36 1.21 total 1.23 2.80 2.11 0.47 3.19 5.20 3.86 0.55 1.23 5.20 2.98 1.02 middle wo 2.32 3.24 2.65 0.29 3.45 4.37 3.94 0.34 2.32 4.37 3.30 .73 ptn 1.46 2.29 1.88 0.31 3.36 4.31 3.78 0.34 1.46 4.31 2.83 1.03 ptu 2.00 2.96 2.40 0.36 4.46 5.37 4.84 0.30 2.00 5.37 3.62 1.29 total 1.46 3.24 2.31 0.45 3.36 5.37 4.19 0.57 1.46 5.37 3.25 1.07 coronal wo 2.54 3.28 2.82 0.28 3.55 4.40 4.02 0.29 2.54 4.40 3.42 .68 ptn 1.56 2.36 1.96 0.27 3.75 4.38 4.00 0.22 1.56 4.38 2.98 1.07 ptu 2.25 3.14 2.68 0.30 4.55 5.35 5.02 0.29 2.25 5.35 3.85 1.23 total 1.56 3.28 2.49 0.47 3.55 5.35 4.35 0.55 1.56 5.35 3.42 1.07 total wo 1.87 3.28 2.64 0.32 3.30 4.40 3.86 0.35 1.87 4.40 3.25 .70 ptn 1.23 2.36 1.83 0.32 3.19 4.38 3.75 0.35 1.23 4.38 2.79 1.03 ptu 1.74 3.14 2.44 0.37 4.22 5.37 4.79 0.36 1.74 5.37 3.61 1.24 total 1.23 3.28 2.30 0.48 3.19 5.37 4.13 0.58 1.23 5.37 3.22 1.06 table 2: push-out bond strength variability of subgroups in each group by site by using two ways anova site group subgroup f sig. single cone guttafusion® mean se mean se apical wave one 2.455 .097 3.609 .097 70.872 .000 protaper next 1.645 .097 3.471 .097 177.445 .000 protaper universal 2.220 .097 4.508 .097 278.595 .000 middle wave one 2.654 .102 3.940 .102 79.571 .000 protaper next 1.879 .102 3.781 .102 174.057 .000 protaper universal 2.404 .102 4.837 .102 284.810 .000 coronal wave one 2.824 .087 4.022 .087 94.152 .000 protaper next 1.959 .087 3.999 .087 273.008 .000 protaper universal 2.682 .087 5.017 .087 357.675 .000 df=1. table 3: lsd tests for push out bond strength among groups by subgroups at three sites site subgroup group group sig. apical single cone waveone protaper next .000 protaper universal .092 protaper next protaper universal .000 guttafusion® waveone protaper next .319 protaper universal .000 protaper next protaper universal .000 middle single cone waveone protaper next .000 protaper universal .089 protaper next protaper universal .001 gutta fusion® waveone protaper next .275 protaper universal .000 protaper next protaper universal .000 coronal single cone waveone protaper next .000 protaper universal .255 protaper next protaper universal .000 gutta fusion® waveone protaper next .853 protaper universal .000 protaper next protaper universal .000 j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 23 table 4: failure mode for different subgroups groups adhesive cohesive mixed group i a 57% 20% 23% group ii a 73% 5% 22% group iii a 70% 10% 20% group i b 16% 21% 63% group ii b 26% 30% 44% group iii b 13% 30% 57% discussion successful endodontic treatment is depending on the adhesion of obturation material to the root canal wall which is advantageous for two reasons. first, it must remove any void that permit fluid leakage between core material and dentine in static situation and the second reason is enabling obturation material to resist its dislodgement during subsequent manipulation in dynamic situations (23).the null hypothesis was rejected since both the instrumentation technique and obturation method was affecting the push-out bond strength. amara et al in 2012 stated that push-out test is popular method for measuring the effectiveness of adhesion between dentine wall and intra-canal material (24). there was a highly significant difference between group i, ii, iii (b) that obturated with carrier based obturation materials (guttafusion®) and group i, ii, iii (a)(single cone obturation technique). an explanation for these results could be attributed to the decreased sealing ability of obturation materials when the thickness of sealer is increased regardless of the instrumentation technique. initially, single cone obturation technique consists of placement of master cone obturation material that matched the last taper and size of file used in instrumentation (25). it was found that group i a (canal instrumented with wo, single cone obturation) showed higher push out bond strength value than group ii a (ptn instrumentation and single cone obturation). an explanation for that taper of master large file (wo) is 08 and this is different from taper of ptn that 06. this led to enlargement of the apical third (especially the last 3 mm) of root canals to an 8% taper which is necessary for irrigation displacement and is enhancing a better sealing ability and long-term success for root canal obturations (26). this agree with wu who found that reciprocation has better performance than continuous movements (wu etal., 2000) (27) and (de-deus et al., 2013) (18). thus, the results disagreed with (pawer et al., 2016) (9). while, group i a (that instrumented with wo and single cone obturation) showed no significant differences with group iii a (instrumented with ptu, single cone obturation). this might be due to absence of a significant difference with 0.06 and 0.08 final taper (26).while, group iii a (ptu instrumentation with single cone obturation) showed highly significant differences than group ii a (ptn instrumentation and single cone obturation). thus result might be related to difference in cross section or mode of rotation since, ptu has a convex triangle cross-section and symmetric rotation while, ptn has a patented, off-centred rectangular cross-section and asymmetric ‘swaggering’ rotation (28). this result disagrees with (li et al., 2014b) who indicated that the protaper next is more efficient in cleaning and shaping the canal more than protaper universal (29). moreover, group iii b (canal instrumented with ptu, guttafusion® obturation) showed highly significant difference compared with group i b and ii b (canal instrumented with wo and ptn, guttafusion® obturation). thus might be due to using of multiple files in some cases to shape and finish the canal completely resulting in more cleaned canal (30). in contrast, there was no significant difference between group i b and ii b (canal instrumented with wo and ptn and obturated with guttafusion®) as in previous study on the shaping ability of rotary instrument; it was found that there were no significant differences between protaper next and the waveone (31). thus agreed with (zogheib et al., 2012) (26). independent of the preparation technique and obturation material, the coronal third showed the highest value of bond strength than the middle third. the apical third showed the lowest value of bond strength due to differences in the internal anatomy of each level of the root canal (32). this disagreed with (babb et al., 2009) (33). after that, each slice was examined under stereomicroscope x 25 to determine the failure mode. in general, the predominant failure mode for canal instrumented with different rotary system (wo, ptn and ptu) and obturated with single cone gutta-percha was adhesive failure mainly at dentine / sealer interface. this may be related to the high amount of sealer relative to j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 24 cone volume since, the sealer was not compacted against the root canal wall resulting in void that might be facilitate the separation of sealer from dentine surface (34).in addition the same groups showed fewer mixed failures followed by cohesive failure mainly within sealer when compared to the other techniques. however, the predominant mode of failure for canal instrumented with previous rotary systems and obturated with guttafusion® was mixed; this may be due to a thin layer of sealer that might be incorporated in the dentinal tubule with slight expansion due to the hydrophilic nature of bc sealer (3) and the thermoplastic gutta-percha had penetrated into the dentinal tubules resulting in well adapted root filling (35) followed by cohesive failures mainly within gutta-percha and then adhesive failure mainly at sealer /dentine interface. references 1. schilder h. filling root canals in three dimensions. joe 2006; 32: 4. 2. yin ly, xie xl, chen mm, liu lh, ling ty. experimental study of preparing curved root canals with different instrument. j west china 2008; 26(6): 660–3. 3. pawar ss, pujar ma, makandar sd. evaluation of the apical sealing ability of bioceramic sealer, ah plus &epiphany: an in vitro study. j cons dent 2014; 17(6): 579-82. 4. malhotra s, hedge mn, shetty c. bio-ceramic technology in endodontics. british j med & med res 2014; 4(12): 2446–54. 5. nagas e, altundasar e, serper a. the effect of master point taper on bond strength and apical sealing abilityof different root canal sealers. oral surg oral med oral pathol oral radiol 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laser surgery 2013; 31(12): 578-85. 12. bürklein s, hinschitza k, dammaschke t, schäfer e. shaping ability and cleaning effectiveness of two single-file systems in severely curved root canals of extracted teeth: reciproc and waveone versus mtwo and protaper. int endod j 2012; 45(5): 449-61. 13. schäfer e, köster m, bürklein s. percentage of guttapercha-filled areas in canals instrumented with nickeltitanium systems and obturated with matching single cones. j endod 2013; 39(7): 924-8. 14. hanna m, daou m, naaman a, zogheib c. push-out strength of 3 warm obturation techniques: warm vertical compaction, guttacore, guttafusion. j int oral health 2016; 8(5): 585-590. 15. ertas h, kucukyilmaz e, ok e, uysal b. push out bond strength of different mineral trioxide aggregates. eur j dent 2014; 8: 348-2. 16. al-kahtani a, al-subait s, anil s. an in vitro comparative study of the adaptation and sealing ability of two carrier based root canal obturators. sci world j 2013; article id 532023: 7. 17. pane es, palamara je, messer hh.critical evaluation of the push-out test for root canal filling materials. j endod 2013; 39(5): 669–73. 18. de-deus g, accorsi-mendonc_at, de carvalho e silva l, de souza leite ca, da silva d, moreira ejl. self-adjusting file cleaning-shaping-irrigation system improves root filling bond strength. j endod 2013; 39: 254–7. 19. türker as, uzunoğlu e, yılmaz z, effects of dentin moisture on the push-out bond strength of a fiber post luted with different self-adhesive resin cements. restor dent endod 2013; 38(4): 234–240. 20. carneiro sm, sousa-neto md, rached fa jr, miranda ce, silva sr, silva-sousa yt.push out strength of root fillings with and without thermo-mechanical compaction. int endod j 2012; 45(9): 821-8. 21. gesi a, raffaelli o, goracci c, pashley dh, tay fr, ferrari m. interfacial strength of resilon and guttapercha to intraradicular dentine. j endod 2005; 31(11): 809-13. 22. el sheikh am, mohamed ge and saba aa. push out bond strength of glass ionomer-impregnated gutta percha/glass ionomer sealer system to root canal dentin conditioned with different endodontic irrigants. eygpt dent j 2011; 57(3): 2351-55. 23. van meerbeek b, peumans m, poitevin a, mine a, van ende a, neves a, de munck j. review relationship between bond strength tests and clinical outcomes. dent master 2010; 26(2): e100-21. 24. amara l, shivanna v, rajesh lv. push out bond strength of the dentine sealer interface with and without a main core: a comparative study using different sealers and cone systems. endodontology j 2012; 24(1): 56-64. 25. monticelli f, sword j, martin rl, schuster gs, weller rn, ferrari m, pashley dh, tay fr. sealing properties of two contemporary single-cone obturation systems. int endod j 2007; 40(5):374-85. 26. zogheib c, naaman a, medioni e, arbab-chirani r. influence of apical taper on the quality of thermoplasticized root fillings assessed by microcomputed tomography.j clin oral investig 2012; 16(5):1493-8. 27. wu mk, fan b, wesselink pr. leakage along apical root fillings in curved root canals: part i—effects of apical transportation on seal of root fillings. j endod 2000; 26(4): 210–16. 28. www.dentsply.com.au. http://www.vdw-dental.com/ https://www.ncbi.nlm.nih.gov/pubmed/?term=aktemur%20t%26%23x000fc%3brker%20s%5bauthor%5d&cauthor=true&cauthor_uid=24303359 https://www.ncbi.nlm.nih.gov/pubmed/?term=uzuno%26%23x0011f%3blu%20e%5bauthor%5d&cauthor=true&cauthor_uid=24303359 https://www.ncbi.nlm.nih.gov/pubmed/?term=y%26%23x00131%3blmaz%20z%5bauthor%5d&cauthor=true&cauthor_uid=24303359 https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3843035/ https://www.ncbi.nlm.nih.gov/pubmed/?term=pashley%20dh%5bauthor%5d&cauthor=true&cauthor_uid=17326785 https://www.ncbi.nlm.nih.gov/pubmed/?term=tay%20fr%5bauthor%5d&cauthor=true&cauthor_uid=17326785 j bagh college dentistry vol. 29(3), september 2017 in vitro the effect restorative dentistry 25 29. li h, zhang c, li q, wang c, song y. comparison of cleaning efficiency and deformation characteristics of twisted file and protaper rotary instruments. eur j dent 2014b; 8(2): 191–6. 30. ruddle cj, machtou p, west jd. the shaping movement: fifth-generation technology. dent today 2013; 32(94): 96–9. 31. ozsu d, karatas e, arslan h, topcu mc.quantitative evaluation of apically extruded debris during root canal instrumentation with protaper universal, protaper next, waveone, and self-adjusting file systems. euro j dent 2014; 8(4): 504-8.40. 32. ebrahimi sf, shadman n, nasery eb, sadeghian f effect of polymerization mode of two adhesive systems on push out bond strength of fiber post to different regions of root canal dentine. dent res j 2014; 11(1): 32-8. 33. babb br, loushine rj, bryan te, ames jm, causey ms, kim j, kim yk, weller rn, pashley dh, tay fr. bonding of self-adhesive (self-etching) root canal sealers to radicular dentine. j endod 2009; 35(4): 57882. 34. robberecht l, colard t, claisse-crinquette a. qualitative evaluation of two endodontic obturation techniques: tapered single-cone method versus warm vertical condensation and injection system: an in vitro study. j oral sci 2012; 54(1): 99-104. 35. migliau g., sofan a.a.a., sofan e.a.a., cosma s., eramo s., gallottini l. root canal obturation: experimental study on the thermafil system related to different irrigation protocols. annali di stomatologia 2014; 5(3): 91-7. الخالصة مختلفة استخدمت تقنيات ارتباط ختم ثالثي األبعاد لنظام قناة الجذرهو أحد األهداف األساسية للمعالجة اللبية. وقد أجريت هذه الدراسة لتقييم قوة الدفع للخارج لقوة waveone, protaper next, protaperلختم القنوات الجذرية التي تم تحضيرها باستخدام ثالثة أنظمة دواره مصنوعة من النيكل والتيتانيوم والتي تتضمن universal)) يسية، كان هناك عشرون ئئي إلى ثالث مجموعات ربشكل عشوا ملم. ثم قسمت الجذور51ستين جذرمقلوع من الضواحك السفلية تم قطعه و ترك الجذر مع طول waveoneيسية األولى مع ئيسية، والتي تم تحضيرها باستخدام انظمه دوارة مختلفة وفقا للمجموعات: تم تحضيرأسنان المجموعة الرئجذر في كل مجموعة ر لكل . protaper universal يسية األخيرة فقد حضرت باستخدامئاما المجموعة الر protaper next يسية الثانية تم تحضيرها باستخدامئوالمجموعة الر لمدة دقيقة واحدة ثم edta ٪51مل من 3ثم يتم غسلها ب %1..1مل من هايبوكلورات الصوديوم بتركيز 3مجموعة تم استخدام نفس نظام الغسل باستخدام .مل من الماء المقطر 3تغسل القنوات ب شكل عشوائي إلى مجموعتين فرعيتين لكل منهما عشرة عينات ، وتمالء المجموعة الفرعية االولى مع تقنية المخروط االحادي بعد ذلك تقسم المجموعة األولى ب وأيضا قسمت المجموعة الثانية إلى مجموعتين فرعيتين، وتمالء واحدة مع تقنية المخروط االحادي ، بينما guttafusion ®وتمأل المجموعة الفرعية الثانية مع . ثم تقسم المجموعة الثالثة عشوائيا إلى مجموعتين فرعيتين. واحدة تمالء مع تقنية المخروط االحادي و guttafusion ®ء المجموعة الفرعية الثانية مع تمال guttafusion .®االخرى تمالء مع ملم )القمي، .فة وكل جذر قطعت منه ثالثة اجزاء ذات سمك بعد ذلك، وضعت الجذور في الحاضنة لمدة سبعة أيام، ثم صبت الجذورفي مادة االكريليك الشفا ملم | دقيقة. تم احتساب 5.1العنقي باستخدام جهاز اختبار عالمي بسرعة -العنقي(وتثبت هذه العينات على قاعدة و يسلط عليها الحمل في االتجاه القمي و الوسطي ميغاباسكال عن طريق قسمة قوة الحمل على المساحة التي يتم احتسابها باستخدام اعلى قوة ارتباط لمادة الحشوة قبل ازاحتها التي تقاس بوحدة (.(autocadبرنامج ,waveone, protaper next) يسية التي حضرت مع انظمة دوارة مختلفةئبين المجموعات الر جداتم إجراء التحليل اإلحصائي وأظهرت النتائج اختالف كبير protaper universal) هناك اختالفات كبيرة جدا بين التقنيتين المستخدمة لمأل قنوات الجذورالمجموعات الفرعية )مخروط احادي ، وكانت اعلى لقوة ارتباط حشوة الجذر من الجزء الوسطي وأظهر هذا األخير قيمة عالية لقوة ( و بالنسبة الجزاء الجذر فقد اظهر الجزءالعنقي قيمةguttafusion®مقابل .ذرمن الجزء القميارتباط حشوة الج https://www.ncbi.nlm.nih.gov/pubmed/?term=ozsu%20d%5bauthor%5d&cauthor=true&cauthor_uid=25512732 https://www.ncbi.nlm.nih.gov/pubmed/?term=karatas%20e%5bauthor%5d&cauthor=true&cauthor_uid=25512732 https://www.ncbi.nlm.nih.gov/pubmed/?term=arslan%20h%5bauthor%5d&cauthor=true&cauthor_uid=25512732 https://www.ncbi.nlm.nih.gov/pubmed/?term=topcu%20mc%5bauthor%5d&cauthor=true&cauthor_uid=25512732 https://www.ncbi.nlm.nih.gov/pubmed/?term=kim%20yk%5bauthor%5d&cauthor=true&cauthor_uid=19345809 https://www.ncbi.nlm.nih.gov/pubmed/?term=weller%20rn%5bauthor%5d&cauthor=true&cauthor_uid=19345809 https://www.ncbi.nlm.nih.gov/pubmed/?term=pashley%20dh%5bauthor%5d&cauthor=true&cauthor_uid=19345809 https://www.ncbi.nlm.nih.gov/pubmed/?term=tay%20fr%5bauthor%5d&cauthor=true&cauthor_uid=19345809 https://www.ncbi.nlm.nih.gov/pubmed/?term=tay%20fr%5bauthor%5d&cauthor=true&cauthor_uid=19345809 type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 10 research article anti-inflammatory effects of manuka honey on salivary cytokines (clinical study) mustafa waseem al-kubaisi1 *, batool hassan al-ghurabi 2, waqar alkubaisy3, nik nairan abdullah4 1 master student, department of dentistry, dijlah university college, baghdad, iraq. 2 professor, phd in microbiology/immunology, department of basic science college of dentistry, university of baghdad/ baghdad, iraq. 3 professor, phd in community medicine, faculty of medicine, mutah university, jordan. 4 phd in department public health medicine, faculty of medicine, universiti teknologi mara, malaysia. * correspondence: mustafa8787waseem@gmail.com; batoolamms@yahoo.com abstract: background: manuka honey (mh) is a mono-floral honey derived from the manuka tree (leptospermum scoparium). mh is a highly recognized for its non-peroxide antibacterial activities, which are mostly related to its unique methylglyoxal content (mgo) in mh. the beneficial phytochemicals in mh is directly related to their favorable health effects, which include wound healing, anticancer, antioxidant, and anti-inflammatory properties. aims: the purpose of this study was to evaluate the effect of mh on pro-inflammatory cytokines (il-8 and tnf-α) in patients with gingivitis and compare it with chlorhexidine (chx) and distilled water (dw). materials and methods: this study was a randomized, double blinded, and parallel clinical trial. forty-five young participants aged (20–40) years were randomly selected and allocated into three groups: mh, chx, and dw mouthwash groups. each participant was given a random bottle. five milliliters each of honey-based mouthwash formulation, chx mouthwashes (0.2%) and dw were used twice daily for 21 days. all the participants were examined twice, once on the zero day (base line) and once after 21 days. before and after each participant's mouthwash use il-8 and tnf-α were measured using enzyme-linked immunosorbent assay (elisa). results: the results revealed a drop in the level of interleukin-8 in the manuka honey group which was statistically significant, but the decrease in the same biomarker in the chlorhexidine group was insignificant statistically. tnf-α levels were found to be insignificantly reduced in both the mh and chx groups (p˃0.05). the dw group, on the other hand, obtained the opposite outcome in both biomarkers. conclusion: mouthwash containing mh had an anti-inflammatory impact, indicating an immunomodulatory action. these signs may be encouraging and promising for the use of mh in treating gingivitis. keywords: manuka honey, interleukin-8, tumor necrosis factor -α, gingivitis. introduction biofilm-induced gingivitis is the most common periodontal condition affecting mankind, with high potential to progress into more destructive periodontal disease if not managed at early stages. although gingivitis is considered as the simplest form of periodontal disease, it is relatively easy to reverse. however, treatment of this condition is crucial as a preventive measure against more progressive periodontal disease, hence preserving the periodontal support and minimizing the need for more complicated and costly treatment (1). cytokines are small, low molecular weight, soluble proteins that are produced in response to an antigen and function as chemical messengers for regulating the innate and adaptive immune systems (2). pro-inflammatory cytokines and chemokines, comprising il-1, il-6, il-8 and tnf-α create an environment that helps disease progression. these cytokines and chemoattractant are secreted by immune regulatory cells, tumor cells, tumor-associated macrophages, and stromal cells (3). tnf-α has the potential to stimulate the production of secondary mediators, including chemokines or cyclooxygenase products, which consequently amplifies the degree of inflammation (4). recently tnf-α regarded as the most important cytokine in the periodontitis pathogenicity could be explained by their role in the destruction and erosive reaction of periodontal tissue, it was manifested, there was none correceived date: 11-07-2022 accepted date: 18-08-2022 published date: 15-03-2023 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/lic enses/by/4.0/). https://doi.org/10.26477/j bcd.v35i1.3310 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3310 https://doi.org/10.26477/jbcd.v35i1.3310 j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 11 relation among concentration of salivary tnf-α and explanation for the chronic, degenerative changes, like indices of plaque and gingival in addition to the probing pocket depth, therefore, tnf-α considered as a good indicator inflammatory process (5). il-8 is a cytokine /chemo attractant protein/chemokine which is produced by a variety of immune inflammatory cells in response to inflammation. il-8 functions primarily to activate neutrophils, and plays a role in pmn recruitment to the inflammatory site. the unique coordinated expression of il-8 facilitates the transit of neutrophils from the highly vascularized gingival tissue to the gingival crevice (6). it is known that il-8 plays a role in angiogenesis by stimulating the formation of new blood vessels through inducing the proliferation of endothelial cells (7). microorganisms and toxins in periodontal tissues stimulate the formation of il-8, which induces a signal for the collection of neutrophils in local sites. il-8 is identified to be a key molecule in the localization, collection and activation of neutrophils (8). because of its pro-inflammatory and neutrophil chemotactic properties, il-8 may play a significant role in the pathogenesis of periodontitis (9). the european workshop on periodontology in 1996 defined, the agents used in chemical supragingival plaque control as antiplaque, anti-gingivitis, plaque reducing, and antimicrobial agents. all of them have been shown to benefit gingivitis by altering the quantity/quality of plaque (10). chx is one of the most effective antimicrobial agents for plaque control and anti-inflammatory. but unfortunately have several adverse effect, the serious side effects of chx are most often associated with its' prolonged use are: oral mucosa ulcer, white patches or sores and desquamative lesions, swelling of salivary glands, signs of an allergic reaction which may include difficulty in breathing or swelling of face, lips, tongue and throat (11). manuka honey contains a high level of potent antioxidant phenolic compounds i.e., flavonoids, methyl syringate, methoxylated benzoic acid, and syringic acid as well as non-phenolics including vitamin c, vitamin e, and β-carotene. methyl syringate in mh is known to possess scavenging activity against superoxide anion radical, and to protect middle-aged sprague-dawley rats from oxidative damage after 30 days of daily supplementation confirming mh antioxidant activity. mh has been used as an anti-inflammatory remedy since ancient times, mostly attributed to its phenolics (12). moreover, mh improved cellular respiration and glycolysis via the activation of phosphorylated 5′ amp activated protein kinase (p-ampk), sirtuin 1, and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (pgc1α) which protect macrophage cells from lps (13). interestingly, mh was found to decrease inflammation in lpsor fmlp (n-formylmethionine-leucyl-phenylalanine, chemotactic peptide)-treated neutrophils through the inactivation of nuclear factor-κb (nf-κb) signaling pathway and the reduction in superoxide release. moreover, the recruitment of neutrophils to fmlp was decreased indicating the beneficial use of mh in the treatment of wounds and suggestive for its dual effect of antimicrobial and anti-inflammatory actions (14). the purpose of this study was to evaluate the effect of mh on pro-inflammatory cytokines (il-8 and tnf-α) in patients with gingivitis and compare it with chx and dw. materials and methods experimental design: this study was a randomized, double blinded parallel clinical trial. it was carried out at the department of basic sciences, college of dentistry, university of baghdad, between november 2021 and april 2022. the study was approved by the ethical committee at dentistry college/ university of baghdad (project no 381821 in november 21-2021). subjects: 45 people with gingivitis were included in this study. each of the three groups had 15 participants. the participation of each participant in the three study groups was randomly assigned. the first group included 15 people who used mh mouthwash; the second group included 15 people who used mouthwash with 0.20 percent chx; and the third group included 15 people who used a placebo (dw) mouthwash. all participants evaluated were asked to complete a systematic questionnaire containing questions about their age, gender, and purpose for attending the dental clinic. in addition, the subject's medical history and past periodontal treatment history were documented. j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 12 sample size: the sample size was determined using g power 3.1.9.7 (program written by franz-faul, universitatit kiel, germany), with a 80 % power of study, an alpha error of probability of 0.05, a correlation between time points of 0.5, an effect size of f of 0.2526 (medium effect size), three major groups, and two time points. inclusion criteria: participants in this research who were deemed eligible must have satisfied the following criteria: subjects aged 20 to 40 years old, in good overall health, with more than 20 teeth, and gingivitis patients. exclusion criteria included active cavity caries and/or periodontal disease, ongoing orthodontic treatment, a history of antibiotic intake within the previous 4 months, the need for prophylactic antibiotic coverage, the need for systemic and/or topical nonsteroidal anti-inflammatory drugs within the previous 4 months, pregnant and lactating mothers, having heart valve replacement and/or any systemic disease, smokers, and using mouthwash within the previous month. saliva sample collection: unstimulated saliva samples were taken for study participants between 9:00 am and 1:00 pm, samples were collected before oral examination using a spit technique (15). then a letter and a number (before b and after a) were assigned to the sample. each participant was given a plastic cup and instructed to allow saliva flow into the cup for five minutes in a quiet. after collection, the samples were immediately centrifuged at 3000 rpm for 10 minutes and the resulting supernatant were stored at -80˚c in eppendorf tubes until further immunological analysis by elisa. oral examination: periodontal health status was recorded through the examination of clinical periodontal parameters (pli and bop) by using a periodontal probe of william's graduation (16, 17). preparation of mh mouthwash: based on a prior study done in new zealand, a manuka honey (514+ mgo; 15+umf) mouthwash was created (18). the dilution ratio was (1:3) (v/v) percent, which means that for every 250 ml of mh, there was 750 ml of dw. the solutions mh, chx, and dw were placed in similar canisters to prevent prejudice between them. the examiner was provided a number-coded intervention sequence list created by a random number generator (microsoft excel 2016) to allocate the blinded intervention. because of this, everyone had the same chance of being put in the intervention sequence. randomization and blinding: this trial was double blinded in which examiner and participants were unable to identify the corresponding intervention. decoding was done at the end of the study. the process of randomization, blindness and intervention allocation were carried out as described in a previous study (19). simple randomization and coding were performed by a third party not involved in the study. in order to ensure blinding of both participants and the examiner, the mouthwashes were dispensed into identical white opaque bottles, measuring 300 ml and each mouthwash group was assigned a random sequential letter (a, b, c) and decoding was performed at the end of the study. microsoft excel (microsoft office 2016, microsoft corporation, usa) was used to generate random numbers that were used to resort the order of the mouthwash groups (a, b, c) and the participants (n=45) so that each group was received equal number of participants (n=15) with 1:1:1 allocation. then, the coded bottles with the mouthwashes were given to the participants together with instructions of use. oral hygiene education: each participant was given oral hygiene instructions. the examiner instructed the participant to brush and paste his / her teeth twice a day, and after finishing brushing for 15 minutes, all the participants were instructed to rinse twice daily (every 12 hours) with 5 ml of the assigned mouthwash (undiluted) for 30 seconds. they were also provided with measuring cups with 5 ml marking in order to use the correct volume of mouthwash. clinical trial: participants attended the dental clinic twice during the study period: once on the zero day (baseline) and once after 21 days. an elisa test for il8 and tnfα was performed on each participant before and after they used mouthwash. measurement of salivary cytokines: tnf-α and il-8 concentrations in saliva were quantified using an elisa according to the instructions in the kit's instruction booklet (shanghai, china). j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 13 calibration a single examiner recorded all participants' pli and bop scores. the calibration of the scoring system in particular was carried out under the supervision of a senior periodontist. the examiner and supervisor reviewed the protocol, the case report form, and the pli and pob criteria one week before the clinical calibration session. 1-inter-examiner assessment: the all surface of all teeth except the third molars for bop and two surfaces except third molar and caries or tooth with filling for pli were examined by the examiner and the supervisor for five randomly selected subjects. 2-intra-examiner assessment: the all surface of all teeth except the third molars for bop and two surfaces except third molar and caries or tooth with filling for pli for five subjects were examined and repeated after two hours by the same examiner. statistical analysis: data description, analysis and presentation have been performed using computerized software statistical package for social science (spss version-22). shapiro wilk test was used to test the normality distribution of the quantitative variable. one-way analysis of variance (anova) parametric test was used to determine and find difference between 3 or more independent groups, and tukey honestly significant difference (hsd)/post hoc test was used to determine if the relationship between two sets of data is statistically significant. paired t-test was used to compare the variables at baseline and after using. the percentage change quantifies the change between the old value and the new one and expresses the change as an increase or decrease. results the mean age of the mh mouthwash group was 30.94 ±7.38 years, the chx group was 30.80 ±8.32 year, and the dw group was 32.4±5.76 years. distribution according to sex, mh group male was 9 (39.1%) and female was 6 (27.3%), chx group male was 5(21.7%) and female was 10(45.5%), whereas, dw group male was 9(39.1%) and female was 6(27.3%). in the mh group, 6 (40%) were in high school and 9 (60%) were post-high school, in the chx group, 6 (40%) were in high school and 9 (60%) were post-high school, while in the dw group, 7 (46.7%) were in high school and 8 (53.3%) were post-high school. the distribution of employment is as follows: in the mh group, 10 (66.7%) were employees and 5 (33.3%) were not. in the chx group, 9 (60%) were employees and 6 (40%) were not, while in the dw group, 7 (46.7%) were employees and 8 (53.3%) were not, as shown in table (1) table 1: demographic characteristic of participants in three groups of the study. demographic characteristics study groups p-value mh n=15 chx n=15 dw n=15 age (years) 0.830ns range (20-40) (20-40) (22-40) mean ± sd 30.9±7.38 30.8±8.32 32.4±5.76 gender 1.000ns female, f (%) 6 (40) 10 (67) 6 (40) male, f (%) 9 (60) 5 (33) 9 (60) education 0.182 ns high school, f (%) 6 (40) 6 (40) 7 (47) post high school, f (%) 9 (60) 9 (60) 8 (53) employment 0.528 ns employee, f (%) 10 (67) 9 (40) 7 (47) non-employee, f (%) 5 (33) 6 (60) 8 (53) f: frequency, %: percentage, mh: manuka honey; chx: chlorhexidine; dw: distilled water j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 14 tumor necrosis factor-alfa tumor necrosis factor-α levels were measured in the study groups at baseline and after 21 days, as shown in table (2) and plotted in figure (1). the mean salivary level of tnf-α in the mh group was (22.29±9.57) at baseline and (19.28±7.15) at 21 days, with a (13%) percentage change that was nonsignificant (p˃0.05). the chx group's mean was (19.17±8.07) at baseline and (16.26±5.91) at 21 days, the reduction was statistically insignificant (p<0.01) with a (15%) percentage change as seen in figure (3-6). while the dw group's mean was (19.43±5.57) at baseline and (20.71±8.25) at 21 days, the mean was raised and statistically insignificant (p˃0.05) with a (6%) percentage change in the negative direction. the tnf-α change among all groups of study between two-time intervals; the mean difference was statistically insignificant (p˃0.05). table 2: mean value of tnf-α in study groups before and after mouthwash use. tnf-α study groups anova (p-value) mh n=15 chx n=15 dw n=15 before 0.717ns range (4.83-41.35) (9.00-33.57) (12.35-29.30) mean± sd 22.29±9.57 19.17±8.07 19.43±5.57 after range (7.57-33.77) (3.75-24.22) (5.17-32.97) mean± sd 19.28±7.15 16.26±5.91 20.71±8.25 0.233ns t-test (p-value) 0.169ns 0.135ns 0.310ns percentage change 13% (decrease) 15% (decrease) 6% (increase) mh: manuka honey; chx: chlorhexidine; dw: distilled water. figure 1: mean values of tnf-α in study groups before and after mouthwash use mh chx dw 22.29 19.17 19.4319.28 16.26 20.71 m e a n o f t n f -α interval of treatment tnf-α before after j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 15 table (3) illustrates the mean difference and intergroup comparisons of mean values of tnf-α for all pairs of groups at day 21. statistically, the comparisons between all groups were non-significant (p˃0.05). table 3: intergroup comparisons of mean values of tnf-α between all pairs of groups after mouthwash use. grouping mean difference tukey's hsd (p-value) tnf-α mh vs. chx 3.02 0.487ns mh vs. dw 1.43 0.848 ns chx vs. dw 4.45 0.217ns mh: manuka honey; chx: chlorhexidine; dw: distilled water. the present findings revealed that the salivary mean level of il-8 in mh group was (53.23±13.80) at baseline and (42.88±12.53) at 21 days, the reduction was statistically significance (p<0.05) with a (19%) percentage change. the mean of il-8 in chx group was (45.79± 9.61) at baseline and (43.42±11.89) at 21 days, the reduction was statistically not significance (p˃0.05) with a (5%) percentage change. while the mean in the dw group was (39.69± 10.42) at baseline and (49.30±12.37) at 21 days, the mean was increase and statistically significance (p<0.05) with (24%) percentage change in negative direction. the il-8 change among all groups of study between two-time intervals; the mean difference was statistically nonsignificant (p˃0.05), as described in table (4) and figure (2). table 4: mean value of il-8 in study groups before and after mouthwash use. il-8 study groups anova (p-value) mh n=15 chx n=15 dw n=15 before 0.008** range (25.2469.54) (31.4362.04) (22.9059.62) mean± sd 53.23± 13.79 45.79± 9.61 39.69± 10.42 after range (24.55-65.28) (17.24-62.18) (32.27-71.95) mean± sd 42.88±12.53 43.42±11.89 49.30±12.37 0.293ns t-test (p-value) 0.020* 0.276ns 0.014* percentage change 19% (decrease) 5% (decrease) 24% (increase) mh: manuka honey; chx: chlorhexidine; dw: distilled water. j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 16 figure 2: mean values of il-8 in study groups before and after mouthwash use. additionally, table (5) shows the mean difference and intergroup comparisons of il-8 mean values at day 21 for all pairings of groups. statistically, all group comparisons were insignificant (p˃0.05). table 5: intergroup comparisons of mean values of il-8 between all pairs of groups after mouthwash use. grouping mean difference tukey's hsd (p-value) il-8 mh vs. chx 0.54 0.992ns mh vs. dw 6.42 0.333 ns chx vs. dw 5.88 0.395ns mh: manuka honey; chx: chlorhexidine; dw: distilled water. discussion regarding salivary il-8, the findings of this study showed a decline in the salivary level of il-8 in the mh mouthwash group before and after use, and the difference was statistically significant. this reduction in il8 levels was seen in the mh group because mh contains high levels of phenolic acid and flavonoids, which are the two most powerful antioxidants and anti-inflammatory agents by quenching reactive free radicals, which are directly related to the hydroxyl level of both compounds and are thought to be responsible for lowering il8 levels (20). it is noteworthy that the effect of mh mouthwash on il-8 levels in gingivitis patients has not been examined before, however there are other studies in which the effect of mh on il-8 levels has been measured in another kind of inflammation. keenan et al. investigated the possibility of using mh internally to treat gastritis caused by helicobacter pylori. it showed significant activity and enhanced the anti-inflammation impact of isothiocyanate-rich broccoli sprouts. reduced cytokine production (e.g., il-8 release from macrophages), induced ros generation, and/or activity in stomach mucosal tissue are all possible. additionally, cyclodextrin-encapsulated mh has been found to decrease inflammation by inhibiting neutrophil tnf release (21). on the other hand, the chx mouthwash also showed decrease in the mean level of salivary il-8 but not statistically significant, this is consistent with previous research on the effect of chx in lowering il-8 levels in gingivitis patients. türkoğlu et al. study found that using chx mouthwash for four weeks reduced the level of il-8 in gingivitis patients (22). this does not imply that chx is ineffective against this biomarker; the cause might be that the research sample was small, the participant did not fully comply mh chx dw 53.23 45.79 39.6942.88 43.42 49.3 m e a n o f in te r le u k in -8 interval of treatment il-8 before after j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 17 with the instructions, or the participant experienced other inflammation throughout the clinical study. in a comparison of mh with chx mouthwashes, the present findings revealed that mh mouthwash had the highest effect in lowering il-8 levels when compared to chx mouthwash. moreover, these results revealed that there was no statistically significant difference between mh mouthwash and chx in reducing of il-8 levels at day 21. tumor necrosis factor-α is a pro-inflammatory cytokine with several immunoregulatory roles. tnf has the ability to trigger the creation of secondary mediators such as chemokines or cyclooxygenase products, which increases the degree of inflammation (23). tnfα and il-8 are secreted by the same cell types, they frequently interact, and many of their pathways are similar, including inflammatory bone resorption. in the development ofa th17 response tnf-α and il-1β are found to amplify the response induced by tgf-β and il-6, but unable to replace any of these cytokines (24). in the current study, salivary level of tnf-α was decrease in the mh and chx mouthwash groups but the difference from baseline was not statistically significant. this can be attributed to the small sample size, compliance to instruction, and may be the participant have another type of inflammation. as with the il-8, no clinical studies have been performed on the efficacy of mh on tnf-α in patients with gingivitis. however, several research (in vivo and in vitro) have been conducted to investigate the effect of honey or its constituents on tnf expression. in an rct study done by tartibian and maleki observed an increase in il-1, il-6, il-8, and tnfin male road cyclists who did not consume honey compared to the group that consumed 70 g of honey for 8 weeks. their findings indicate that honey intake during long-term exercise can lower seminal plasma cytokines while increasing antioxidant levels (25). moreover, ahmed colleagues' study was performed on the sprague-dawley rats, and the results showed that systemic administration of tualang honey (th) and mh increases the susceptibility to expression of proapoptotic proteins (apaf-1, caspase-9, ifn-γ, ifngr1, and p53) and decreases the expression of antiapoptotic proteins (tnf-α, cox-2, and bcl-xl 1) in its mechanism of action. it suggests that, th and mh may have a novel role in alleviating breast cancer (26). other authors, however, have indicated that manuka and other types of honey can reduce tnf-α expression in vitro studies (candiracci et al., 2012; song et al., 2012; majtan et al., 2013; safi et al., 2016; al-abd et al., 2017) (27). similarly, majtan et al. investigated the influence of flavonoid content in honey on inhibiting tnf-α-induced mmp-9 expression in human keratinocytes, and the results showed that flavonoid content in honey suppressed tnf-α-induced mmp-9 expression in immortalized human keratinocytes (hacat) (28). all of the previous investigations support findings that mh has the ability to lower the amount of tnf-α. honey's anti-inflammatory effect may be explained by several mechanisms of action, including; inhibition of the classical complement pathway, inhibition of reactive oxygen species formation (23), inhibition of leucocyte infiltration (29) and inhibition of cyclooxygenase-2 (cox-2) and inducible nitric oxide synthase expression (inos) (30). honey's anti-inflammatory action is mostly attributed to phenolic constituents, especially flavonoids. chrysin has been demonstrated to be an effective anti-inflammatory chemical. it reduces the production of no and pro-inflammatory cytokines such as tnf-a and il-1b and inhibits lps-induced cox-2 expression by inhibiting nuclear factor for il-6 dna-binding activity (30, 31). on the other hand, the third (placebo) group in both biomarkers showed negative results. this is a logical finding given that dw lacks anti-inflammatory properties like mh and chx. conclusion manuka honey revealed an anti-inflammatory activity by significantly decreasing il-8 levels. it also decreased tnf levels. all of the evidence points to mh being a safe agent that might be used as a component in mouthwash formulations. to promote oral health, this study recommend utilizing mh. according to the findings of thisstudy, il8 might be a useful immunological marker for gingivitis. j. bagh. coll. dent. vol. 35, no. 1. 2023 al-kubaisi et al 18 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blocking nf-κb and jnk activations in microglia cells. neurosci letters. 2010; 485(3): 143-7. ( دراسه سريرية ) tnfαو il8العنوان: تقييم آثار عسل مانوكا على 2* ، بتول حسن الغرابي 1مصطفى وسيم الكبيسي الباحثون: المستخلص: معترف به بشكل كبير ألنشطته غير البيروكسيدية المضادة mh .(leptospermum scoparium)( هو عسل أحادي األزهار مشتق من شجرة مانوكا mhالخلفية: عسل مانوكا ) ارتباطًا مباشًرا بآثارها الصحية اإليجابية ، والتي تشمل mh. ترتبط المواد الكيميائية النباتية المفيدة في mh( في mgoللبكتيريا، والتي ترتبط في الغالب بمحتواها الفريد من ميثيل جليوكسال ) و il-8على السيتوكينات المؤيدة لاللتهابات ) mhات السرطان ، ومضادات األكسدة ، وخصائصها المضادة لاللتهابات. األهداف: الغرض من هذه الدراسة هو تقييم تأثير التئام الجروح ، ومضاد tnf-α( في مرضى التهاب اللثة ومقارنتها بالكلورهيكسيدين )chx( والماء المقطر )dwلدراسة عبارة عن تجربة سريرية عشوائية مزدوجة التعمية ومتوازية. (. المواد والطرق: كانت هذه ا . تم إعطاء كل مشارك dwو chxو mh( عاًما بشكل عشوائي وتم تقسيمهم إلى ثالث مجموعات: مجموعات غسول الفم 40-20تم اختيار خمسة وأربعين مشاركًا شابًا تتراوح أعمارهم بين ) يوًما. تم فحص جميع المشاركين مرتين ، مرة في يوم 21مرتين يوميًا لمدة dw٪( و 0.2) chxمليلتر من كل من غسول الفم القائم على العسل وغسول الفم زجاجة عشوائية. تم استخدام خمسة (. النتائج: أظهرت elisaتز المناعي المرتبط باإلنزيم )باستخدام مقايسة المم tnf-αو il-8يوًما. قبل وبعد استخدام غسول الفم لكل مشارك تم قياس 21بعد الصفر )خط األساس( ومرة في مجموعة عسل مانوكا كان ذا داللة إحصائية ، لكن االنخفاض في نفس المرقم الحيوي في مجموعة الكلورهيكسيدين كان ضئياًل من الناحية interleu-kin-8النتائج انخفاًضا في مستوى على النتيجة المعاكسة في dw. من ناحية أخرى ، حصلت مجموعة chx (p˃0.05)و mhانخفضت بشكل ضئيل في كل من مجموعات tnf-αاإلحصائية. تم العثور على أن مستويات في mhله تأثير مضاد لاللتهابات ، مما يشير إلى وجود تأثير مناعي. قد تكون هذه العالمات مشجعة وواعدة الستخدام mhكل من المرقمات الحيوية. االستنتاج: غسول الفم الذي يحتوي على عالج التهاب اللثة. j bagh college dentistry vol. 26(1), march 2014 distribution of tooth wear orthodontics, pedodontics and preventive dentistry 180 distribution of tooth wear among institutionalized residents (50-89 years old) in baghdad city\ iraq (cross-sectional study) mohammed g. al-azawi, b.d.s. (1) sulafa k. el-samarrai, b.d.s., m.sc., ph.d. (2) abstract background: tooth wear is one of the most common problems in the older dentate population which results from the interaction of three processes (attrition, abrasion and erosion) and it affects all societies, different age groups, and all cultures. this study was achieved to evaluate the prevalence and distribution of tooth wear among institutionalized residents in baghdad city\ iraq. subjects and methods: this survey was accomplished on four private and one governmental institution in baghdad city. one-hundred twenty three (61 males, 62 females) aged 50-89 years were participated in this study. the diagnosis and recording of tooth wear were according to criteria of smith and knight. results: the prevalence of tooth wear was 100% with a mean (30.79± 19.39) and median (28). the highest grade of tooth wear recorded was grade 2 (56.9%), followed by grade 3 (26%), grade 4 (17.1%). there was no statistically significant difference of total tooth wear among age groups (p>0.05), astatistically significantdifference was seen regarding the severity of tooth wear among different age groups; for grade 2 and grade 4 (p <0.05), while a statistically highly significant difference recorded for both grade 1 and grade 3. a statistically highly significant difference of the total tooth wear was recorded between the total males and females (p <0.01). conclusion: the occurrence of tooth wear among those subjects was high thus they need oral health policy makers for promotion, prevention and restorative care. key words: tooth wear, institutionalized elderly. (j bagh coll dentistry 2014; 26(1):180-183). introduction older people suffer from many oral health problems as studied by previous iraqi studies like coronal and root caries (1,2), edentulism(1), periodontal diseases (2), dry mouth, soft tissue lesions and age related odontometric changes as tooth wear (3). tooth wear describes the non-carious loss of tooth tissue, and is one of the most common problems in the older dentate population which results from the interaction of three processes (attrition, abrasion and erosion) (4, 5). tooth wear seems to affect all societies, different age groups, and all cultures (6, 7). the clinical significance of this increase negatively impacts on aesthetics and/or function (8). as available, this is the first iraqi cross-sectional study to determine the prevalence, distribution of tooth wear among institutionalized residents in baghdad city. such a study may provide a baseline data aids for future comparison with other studies, as well as putting strategies for monitoring, prevention and treatment of tooth wear among this group of adults. (1) m.sc student department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) professor department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. subjects and methods this study was conducted during the period between the fourth of november on 2012 and twelfth of january on 2013 among five institutions in baghdad city. there were about 214 institutionalized residents (91males, 123 females) distributed in four private and one governmental institution, with age range about 50-89 years old according to the report of ministry of labor and social affairs. after getting approval of the ministry of labor and social affairs to carry out this study, contacts with institution’s authorities were made to explain the purpose of the study. the exclusion criterion was cognitive impaired individuals who were 13 subjects (5 males, 8 females). the initial step and before data collection, examiners explained to the participants the aims and details of the study to participate for a detailed interview and a clinical examination. every subject was informed of his or her right to refuse participation or to withdraw from the study at any moment. the authority of dar anya totally refused the examination with unexplained reasons thus the number of residents who refused was 45 (9 males, 36 females) thus the participants was 156 (77 males, 79 females) and those 33 subjects were divided into completely edentulous (17, 51.5%) and those with complete denture wearers (16, 48.5%) were excluded thus the net number of individuals for tooth wear examination was 123 subjects. clinical examination was performed inside the institution with the aid of dental mirror and j bagh college dentistry vol. 26(1), march 2014 distribution of tooth wear orthodontics, pedodontics and preventive dentistry 181 explorer. teeth were dried using cotton rolls. the exclusion criteria were as follows: any participants received restorative treatment for tooth surface loss, badly carious tooth and teeth received fixed prosthesis al-zarea, (12). the surfaces of all teeth were scored according to tooth wear index by smith and knight (9). intra and inter calibration were performed to overcome any problem that could be faced during the research, and to ensure proper application of diagnostic criteria used in recording dental status through inter calibration. statistical analysis and processing of the data were carried out using spss version 18. the statistical tests that were used in are pair sample t-test, z-test, mannwhitney utest, kruskalwallis h test, spearman correlation coefficient and chi-square. the level of significance was accepted at p< 0.05, and highly significance when p< 0.01. results in this study, not all the elderly individuals were involved in the diagnosis and recording of tooth wear as those 33 subjects were divided into completely edentulous (17, 51.5%) and those with complete denture wearers (16, 48.5%) were excluded. concerning the remaining dentate individuals as those 123 subjects (61 males, 62 females), the percentage of individuals with tooth wear in this study was 100% with a mean (30.79± 19.39) and median (28) as all the elderly examined were having one or more types of tooth wear. results illustrate that the distribution of subjects by their highest grades of tooth wear was grade 2 and seen in 56.9% (70 subjects) of the examined subjects followed by those with grade 3 (26%, 32 subjects), the lowest was those with grade 4 (17.1%, 21 subjects) followed by those with grade 1 which was completely absent. regarding age; results in table 1 show that rating of total tooth wear among age groups was found to be statistically not significant (p >0.05) when kruskal-wallis h test was applied. tooth wear by grades of severity according to age groups is demonstrated in table 2. results indicate that the differences in the severity of tooth wear among age groups were found to be statistically significant for grade 2 and grade 4 (p <0.05) and highly significant for grade 1 and grade 3 (p <0.01). table 3 illustrates that tooth wear according to gender in different age groups. males demonstrated a high tooth wear values compared to females in all ages, however differences were found to be statistically not significant (p >0.05), while the difference was statistically highly significant between the total males and females (p <0.01) according to mann-whitney u test. discussion the prevalence of tooth wear among elderly population as seen by this study was 100% which is higher than that found by taiwo et al (11) 92.8% among nigerian individuals, aged 65 years and above. in this study, results demonstrate that grade 2 was the highest score, while the least was grade 1, this is in agreement with alzarea(12)whose sample’s age was from 15-65 among saudian adults, and disagree with daly et al (13) who found that the highest grade was grade 1 (81%), among 18-80 years malizian adults. results in this study demonstrated that rating or ranking total tooth wear among age groups was not significant although all tooth wear values decreased with the increase of age, except at the last age group, a tooth wear increased. previous studies, concluded that tooth wear was an accumulative process throughout life and was an age-related phenomenon (10, 14-16); but severe tooth wear is not and could happen during any period of life (17). many studies recorded that severe levels of wear could be observed in each age group, and it could be argued that this was independent of age (7,18,19). the increase teeth exposure to environmental factors (local or systemic, erosive, attritive or abrasive factors) may cause more tooth wear rather than age per say (16,20,21). further longitudinal studies are needed among single age group to explore the effect of aging and determine the accumulation of tooth wear throughout their life. results recorded that total tooth wear values were higher among males than those of females with a highly significant difference. this may due to increased muscle mass and muscular strength seen in males in general (5, 17), other results found that males had higher magnitude of bite forces than females (15, 22, 23). studies of tooth wear among adults revealed that tooth wear is also significantly more prominent in men than women (9, 24), due to different dietary patterns between the two genders (25). females may care more about their dentition and visit dentists more than males and this allows early detection with possible preventive program being introduced to stop progression (12). institutionalized older adults suffer from tooth surface loss thus they need public health campaigns aimed at reducing the incidence of and progression of tooth wear lesion among them. j bagh college dentistry vol. 26(1), march 2014 distribution of tooth wear orthodontics, pedodontics and preventive dentistry 182 references 1al-damerchi j. suzan. oral health status and treatment needs among iraqi institutionalized elderly population. m.sc. thesis. college of dentistry, university of baghdad, 2001. 2al-yas ab. salivary antioxidants and physiochemical characteristics related to oral health status among group of older adults. phd. thesis college of dentistry, university of baghdad, 2009. 3roopa nr, usha g, kumar v, rao r, bugalia a. geriatric restorative care the need, the demand and the challenges. j conservative dentistry 2011; 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(ivsl). 11taiwo jo, ogunyinka a, onyeaso co, dosumu oo. tooth wear in the elderly population in south east local government area in ibadan, nigeria. odontostomatol trop 2005; 28(112): 9-14. 12al-zarea bk. tooth surface loss and associated risk factors in northern saudia arabia. international scholarly research network (isrn) dentistry. 2012; 2011:161565. doi: 10.5402/2012/161565. epub 2012 aug 7. 13daly r wirdatul r, wan zaripah wan bakar, adam huseinnoorlizamastura. the study of tooth wear patterns and their associated aetiologies in adults in kelantan, malaysia. archives of orofacial sciences 2010; 5(2): 47-52. 14nunn j, morris j, pine c, pitts nb, bradnock g, steel j. the condition of teeth in the uk in 1998 and implication for the future. br dent j 2000 23; 189(12): 639-44. 15bernhardt o, gesch d, splieth c, schwhan c, mack f, kocher t, meyer g, jhon u, kordass b. risk factors for high occlusal wear scores in a population based sample: results of study of health in pomerania (ship) int j prosthodont 2004; 17(3): 333-9. 16arnadottir ib, holbrook wp, eggertsson h, gudmundsdottir h, jonsson sh, gudlaugsson jo, saemundsson sr, eliasson st, agustsdottir h. prevalence of dental erosion in children: a national survey. community dent oral epidemiol 2010; 38: 521-526. 17seligman da, pullinger ag, solberg wk. prevealnce of dental attrition and its association with factors of age, gender, occlusion and tmj symptomatology. j dent res 1988; 67(10): 1323-33. 18smith bgn, robb nd. the prevelance of tooth wear in 1007 dental patients. j oral rehabil 1996; 23: 23239. 19richards lc, kaidonis ja, townsend gc. a model for the prediction of tooth wear in individuals. aust dent j 2003; 48(4): 259-62. 20donachie ma, walls awg. the tooth wear index: a flawed epidemiological tool in an ageing population group. community dent oral epidemiol 1996 24: 152-158. 21hamudi z. genetic and environmental influences on variation in overbite, overjet, and tooth wear. degree of doctor thesis, university of adelaide, 2011. 22van der glass hw, lobbezzoo f, van der bilt a, bosman f. influence of the thickness of soft tissues overlying human masseter and temporalis muscles on the electromyographic maximal voluntary contraction level. eur j oral sci 1996; 104: 87 95. 23pigno ma, hatch jp, rodrigesgarcia rc, sakai s, rauph jd. severity, distribution and correlates of occlusal tooth wear in a sample of mexican – american and european-american adults. int j prosthodont 2001; 14: 65-70. 24oginni o, olusile ao. the prevalence, aetiology and clinical appearance of tooth wear: the nigerian experience. i n t e r d e n t j 2002; 52: 268-72. 25harnack l, stang j, story m. soft drink consumption among us children and adolescents: nutritional consequences. j a m d i e t e t i c a s s o c 1999, 99(4): 436-441. table 1: descriptive and statistical results of tooth wear according to age ^= not significant at p >0.05. age group no. mean ±sd median mean rank chi-square df p-value 50-59 26 32.04 17.12 32.00 66.71 1.093 3 0.779^ 60-69 34 30.94 18.31 31.500 63.97 70-79 35 30.09 21.78 21.00 57.81 80-89 28 30.36 20.48 27.00 60.46 total 123 30.79 19.39 28.00 http://www.jcd.org.in/searchresult.asp?search=&author=g+usha&journal=y&but_search=search&entries=10&pg=1&s=0 http://www.jcd.org.in/searchresult.asp?search=&author=vinod+kumar&journal=y&but_search=search&entries=10&pg=1&s=0 http://www.jcd.org.in/searchresult.asp?search=&author=raghoothama+rao&journal=y&but_search=search&entries=10&pg=1&s=0 http://www.jcd.org.in/searchresult.asp?search=&author=anupriya+bugalia&journal=y&but_search=search&entries=10&pg=1&s=0 http://www.ncbi.nlm.nih.gov/pubmed?term=taiwo%20jo%5bauthor%5d&cauthor=true&cauthor_uid=16491916 http://www.ncbi.nlm.nih.gov/pubmed?term=ogunyinka%20a%5bauthor%5d&cauthor=true&cauthor_uid=16491916 http://www.ncbi.nlm.nih.gov/pubmed?term=onyeaso%20co%5bauthor%5d&cauthor=true&cauthor_uid=16491916 http://www.ncbi.nlm.nih.gov/pubmed?term=dosumu%20oo%5bauthor%5d&cauthor=true&cauthor_uid=16491916 http://www.ncbi.nlm.nih.gov/pubmed?term=al-zarea%20bk%5bauthor%5d&cauthor=true&cauthor_uid=22919505 j bagh college dentistry vol. 26(1), march 2014 distribution of tooth wear orthodontics, pedodontics and preventive dentistry 183 table 2: descriptive and statistical results of tooth wear by grades of severity according to age table 3: descriptive and statistical results of tooth wear according to gender # = mean rank, ##=sum rank, ^ =not significant at p>0.05, **=highly significant at p<0.01. g r a d e 1 age groups (years) no. mean ±sd median mean rank chi-square df p-value 50-59 26 6.89 6.55 5.00 83.02 17.947 3 0.000** 60-69 34 3.62 4.99 1.00 62.82 70-79 35 1.34 2.59 0.00 45.87 80-89 28 3.00 4.11 1.00 61.64 g r a d e 2 50-59 26 12.15 8.86 11.00 72.13 7.911 3 0.048* 60-69 34 11.29 7.47 9.50 69.46 70-79 35 7.05 5.11 6.00 49.87 80-89 28 8.31 5.39 7.00 58.70 g r a d e 3 50-59 26 0.30 0.97 0.00 43.60 13.690 3 0.003** 60-69 34 1.26 3.00 0.50 60.59 70-79 35 4.23 6.09 2.00 72.71 80-89 28 2.18 3.22 1.00 67.41 g r a d e 4 50-59 26 0.00 0.00 0.00 52.00 9.798 3 0.020* 60-69 34 0.23 0.78 0.50 59.19 70-79 35 0.48 1.24 1.00 65.83 80-89 28 0.82 1.94 2.00 69.91 age group (years) gender no. mean ±sd median mr# sr## z-value p-value 50-59 males 14 34.57 4.39 34.00 15.25 213.50 -1.262 0.207^ females 12 29.08 18.17 27.50 11.46 137.50 60-69 males 22 31.68 14.42 33.00 18.66 410.50 -0.920 0.358^ females 12 29.58 24.62 22.50 15.38 184.50 70-79 males 19 36.95 25.86 28.00 20.50 389.50 -1.577 0.115^ females 16 21.94 11.93 19.00 15.03 240.50 80-89 males 6 44.00 25.19 47.50 19.33 116.00 -1.625 0.104^ females 22 26.63 17.90 23.50 13.18 110.34 total males 61 35.19 19.95 33.00 70.55 4303.50 -2.639 0.008** females 62 26.47 17.97 23.50 53.59 3322.50 zainab.docx j bagh college dentistry vol. 28(1), march 2016 cone beam computed oral diagnosis 99 cone beam computed tomography in an evaluation and diagnosis of anatomical variations and pathological lesions in maxillary sinus prior to maxillary sinus lift surgery zainab h. al-ghurabi, b.d.s, m.sc. (1) abstract: thorough assessment of the maxillary sinus is very important. recently 3-dimensional image with cone beam computed tomography (cbct) is very dependable in maxillary sinus diagnosis. the aim of this study is to: shade light on the role of (cbct) diagnosis of the maxillary sinus anatomical variation and pathological finding among smokers and nonsmokers prior to maxillary sinus lift techniques. materials and method: in this study 60 males with age ranged between 20-50 years old, referred for (cbct) assessment of maxillary sinus in the specialist health center of al-sadder city. the scanning were performed using kodak 9500 (cbct), the kv was 90, ma10 and scanning time 10 s. voxel size 0.3mm with( dicom ) software on a multiplaner reconstruction window in which the axial, coronal and sagittal plane could be visualized in 0.3 mm interval, 40 were smokers and 20 nonsmokers, both sides were evaluated to assess the presence of septa, maxillary sinus membrane (schneiderian membrane)thickening, complete opacification and adenoid polyp. result:the maxillary for nonsmoker patients (20) patients were clean and have no any pathological or anatomical changes, among smoker patients, it was found that 7 (17.5%) of them had a clean maxillary sinus, 25 (62.5%) patient from smokers, the mucosal thickening was clear and measured more than 4 mm, 20 (80%) of them bilateral maxillary sinus were involved and 5 (20%) of them have a unilateral thickening, 6 (15%) of the smoker patient have bilateral involved adenoid with max sinus, and 2(5%) of them have full opacification., no septa was found in this study. conclusion:cone beam computed tomography(cbct)was themost useful technique to diagnose maxillary sinusbefore maxillary sinus augmentation, an evaluation ofcone beam computed tomography(cbct)scans before implant surgery or sinus augmentation procedures has extreme clinical importance in evaluation of anatomic structures, such as thickening of the schneiderian membrane and presence of pathological lesion such as adenoid polyp. key words: cone beam computed tomography, maxillary sinus, anatomical variations. (j bagh coll dentistry 2016; 28(1):99-102). introduction sound knowledge of maxillary sinus and its anatomical variationsis very importantfor surgeons,especially before surgical procedures, such as insertion of dental implants with or without maxillary sinus lifting (1-3). anatomic variations within the sinus, such as septa and mucosal thickening of the sinus floor increase the possibility of the sinus membrane perforation during preimplant surgery in maxillary sinus(4). very few knowledge about the thickening and the dimension of the maxillary sinusmembrane, there is no specific method for evaluationand classification of mucosal findings in it. many findings determined that, the thickening of maxillary sinus mucosa less than 2 mm was consider asa normal variant(5,6). radiographically, the normal maxillary sinus, because it is air filled so it is radiolucent structure, while its walls appear as radiopaque(7). in the case of a diseased sinus, a radiologist may observe clouding (opacifying) or mucosal thickening(8). (1) lectuere, department of oral diagnosis, college of dentistry, university of baghdad. thorough assessment of the maxillary sinus is very important. panoramic imaging technique is used widely in dentistry but it is still 2dimensional image that loss some important anatomical details recently, (cbct) isconsidered as an acceptable alternative. since the end of 90s(cbct) has become a popular imaging technique in dentistry, even for visualization of the paranasal sinuses(9,10). (cbct) can accurately capture, display and provide undistorted 3-dimensional view of maxillofacial anatomy and pathology. it is important to be acquainted with different anatomic and pathologic findings in maxillary sinus, (cbct) scanning has become the standard in dentistry for evaluating the maxillary sinuses because of the ability to accurately scanning the sinus in multiple views with thin sectioning (11). (cbct) images allow localizing the anatomic structures and providing information about bone dimensions and morphology (12,13). the relationship between smoking and thickening of sinus mucosa was directrelationship (17). the effect of smoking and non-allergic inhalants cause chronic inflammation of the nasal and sinus mucosa which may lead to adenoid polyp formation (18). j bagh college dentistry vol. 28(1), march 2016 cone beam computed oral diagnosis 100 the present study was designed to: 1-shed light on the importance of (cbct) in pre implant evaluationfor patients who have alveolar bone loss in the maxillary sinus area. 2to compare the maxillary sinus appearance and pathological images between smokers and nonsmokers. materials and methods in the present study 60 males with age ranged between 20-50 years old,(mean 35 years)referred to(cbct) scanning for maxillary sinus in specialist health center in al-sadder city.the scanning were performed using kodak 9500 (cbct), french origin, the kv was 90, ma10 and time of scan 10 s. voxel size 0.3mm with(dicom) software on a multiplaner reconstruction window in which the axial, coronal and sagittal plane could be visualized from period between september 2014 to march 2015. cbctscan was done for all patients to assess the presence of any anatomical variation or pathological finding pre implant associated with maxillarysinusaugmentation. scanning of maxillary sinus was performed by using three orthogonal slices. the (cbct) scans were analyzed by independent two readings by the specialist radiologist.the criteria of evaluation based on scanning of:(1) presence of septa, (2)mucosal thickening more than 2mm,(mucosa was measured from different point corresponding to the underlying bone in the area of 1st,2nd premolars and 1st,2nd molars, the highest point was recorded),(3)full opacification of maxillary sinus and/or any other (4) pathological finding. classification of mucosal thickening (14). (1) flat: shallow thickening without welldefined(irregular)outlines. (2)semi-spherical: thickening with well defined(round)outline (3) mucocele-like: complete opacificationofthe sinus. all patients were asked about: age, tobacco use, classified as with duration of more than 2 years, history of sinusitis and time of last extraction. all patients were informed about the aim and method of the study and they fill a special consent form after their agreement in participation. chi square statistical analysis was used to compare the result finding between smokers and nonsmokers. (a) (b) figure 1: (a&b) coronal view showing bilateral thickening of maxillary sinus membrane. figure 2: coronal view showing unilateral thickening of maxillary sinus membrane (a) (b) figure 3: (a) axial & (b) coronal showing full opacification of the lt. maxillary sinus j bagh college dentistry vol. 28(1), march j bagh college dentistry vol. 28(1), march oral diagnosis figure 4 represent bilateral maxillary sinus adenoid result the included in the sample, 40 of them smokersand 20 as shown in the table nonsmoker patient pathological or anatomical changes table 1 presence of septa thickening adenoid full opacification figure 4: j bagh college dentistry vol. 28(1), march oral diagnosis figure 4: (a) axial and (b) coronal view represent bilateral maxillary sinus adenoid results the (cbct) scanning luded in the sample, 40 of them and 20 nonsmoker as shown in the table nonsmoker patients were ological or anatomical changes table 1: clear the p criteria presence of septa clear thickening more than 4 mm. bilateral unilateral adenoid bilateral full opacification total figure 4: the percentages 0 10 20 30 40 50 60 70 80 90 100 clean j bagh college dentistry vol. 28(1), march (b) : (a) axial and (b) coronal view represent bilateral maxillary sinus adenoid polyp scanning of 60 patient luded in the sample, 40 of them nonsmokers. as shown in the table 1, maxillary sinus were totally clear ological or anatomical changes the percentage of th the side among t presence of septa more than 4 mm. bilateral unilateral bilateral full opacification *percentages were calculated from 25 cases ercentages of the thickening, adenoid and full o clean more than 4 j bagh college dentistry vol. 28(1), march : (a) axial and (b) coronal view represent bilateral maxillary sinus adenoid of 60 patients were luded in the sample, 40 of them were maxillary sinus clear and have no ological or anatomical changes (mucosal ercentage of the thickening, adenoid and full o the side among t smokers no. (%) 0 7 (17.5%) 25 (62.5%) 20 (80%) * 5 (20%) * 6 (15%) 2 (5%) 40 (100%) *percentages were calculated from 25 cases of the thickening, adenoid and full o thickening more than 4 mm. j bagh college dentistry vol. 28(1), march 101 : (a) axial and (b) coronal view represent bilateral maxillary sinus adenoid were were maxillary sinus for and have no (mucosal thickening and full opacification) smoker 40 s sinus with maxillary sinus which fig bilateral maxillary sinus fig1, maxillary sinus opacification which was seen only among smoker patient patients sinus as shown significant since the anatomi pathological smoker e thickening, adenoid and full o the side among two study g non-smokers no. (%) 0 20 (100%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) 20 (100%) *percentages were calculated from 25 cases of the thickening, adenoid and full o adenoid j bagh college dentistry vol. 28(1), march 2016 thickening and full opacification) smoker patients 40 smoker patient sinus, and 25 (62.5%) from 40 with maxillary sinus whichmeasured fig1,from those 25 patients20 bilateral maxillary sinus fig1, and 5 (20%) of the maxillary sinus two patients opacification which was seen only among smoker patients fig 3, patients have sinus(bilateral involved as shown in figure 4. the difference between significant since the anatomi pathological finding smokersgroup. e thickening, adenoid and full o study groups smokers x2 0 20 (100%) 36.667 20 (100%) *percentages were calculated from 25 cases of the thickening, adenoid and full o full opacification thickening and full opacification) s it was found that, 7 (17.5%) moker patient were showed a clear maxillary 25 (62.5%) from 40 with maxillary sinusmucosal thickening measured more than 4 mm as shown from those 25 patients20 bilateral maxillary sinus were inv and 5 (20%) of the unilateral thickening as clear in figure patients(5%) of smoker patients opacification which was seen only among smoker , 6 patients (15%) among smoker have a pathology bilateral involved) which is in figure 4. the difference between two significant since the anatomi findings were found only e thickening, adenoid and full opacification roups. groups' difference likelihood ratio 0 45.479 *percentages were calculated from 25 cases of the thickening, adenoid and full opacification full opacification cone beam computed thickening and full opacification), while among it was found that, 7 (17.5%) were showed a clear maxillary 25 (62.5%) from 40 patient associated mucosal thickening more than 4 mm as shown from those 25 patients20 (80%) of them were involved as clear in unilateral thickening as clear in figure 2. (5%) of smoker patients opacification which was seen only among smoker 6 patients (15%) among smoker pathology of maxillary ) which is adenoid two groups was highly significant since the anatomical changes s were found only pacification in respect to groups' difference likelihood ratio d.f. 0 45.479 3 pacification for both g smokers non-smokers cone beam computed , while among it was found that, 7 (17.5%) from were showed a clear maxillary associated mucosal thickening more than 4 mm as shown (80%) of them as clear in unilateral thickening of have full opacification which was seen only among smoker 6 patients (15%) among smoker of maxillary adenoid polyp, groups was highly cal changes and s were found only among in respect to p-value 0 0.000 (hs) for both groups. smokers cone beam computed j bagh college dentistry vol. 28(1), march 2016 cone beam computed oral diagnosis 102 discussion in the present study after the evaluation of maxillary sinus it was found that the thickening of sinus membranehas the highest percentage among the other changes (62%), while the full opacification was found in only 2patients (5%) ,this com in conformity with ilze et al.,(15) who found that, there was thickening in 19 patient from 33 patient, 14 bilateral and 5 unilateral , slight difference of the percentage between twostudies may be due to sample size differences and also conform with regaetal.,(16) who stated that, the most prominent anatomical changes was thickening of maxillary sinus membrane followed by full opacification. it is clear thatthere is a direct relationship between smoking and thickening of sinus mucosa which is agreement with janner et al.,(17). in this study, it was found that 6 patients involved with adenoid polyp and all of them were bilatera, since the smoker effect on the sinuses as its effect on lung epithelial, especially these adenoid were found only among smoker patientsand this disagree with ilze et al.,(15)who found no pathological findings among his sample. while gorgulu et al.,(18) result is very near to the presentresults, they approved that, smoking is found to be the only risk factor for development of maxillary sinus and nasal polyp, and they concluded that the smoking restriction and avoiding exposure to cigarette smoking by patient with nasal polyps may be important in prevention of the recurrence of nasal and sinus polyp. according to the result of thepresent study,one can considercbctasan accurate diagnostic tool to evaluate the anatomical changes pathological disease in maxillary sinus and significant effects of smoking on maxillary sinus. references 1chan hl, wang hl. sinus pathology and anatomy in relation to complications in lateral window sinus augmentation. implant dent 2011; 20:1-7. 2naitoh m, suenaga y, kondo s, gotoh k, ariji e. assessment of maxillary sinus septa using conebeam computed tomography: etiological consideration. clinical implant dentistry and related research 2009; 11: 52–8. 3özyuvaci h, aktas i, yerit k, aydin k, firatli e. radiological evaluation of sinus lift operation: what the general radiologist needs to know. dentomaxillofac radiology 2005;34: 199–204. 4neugebauer j, ritter l, mischkowski ra, dreiseidler t, schherer p, ketterle m.evaluation of maxillary sinus anatomy by cone– beam ct prior to sinus floor elevation. int j oral maxillofac implants 2010;5:258–5. 5rak km, newell jd, yakes wf, damiano ma, luethke jm. paranasal sinuses on mr images of the brain: significance of mucosal thickening. ajr am j roentgenol 1991; 156:381–4. 6thunthy kh. diseases of the maxillary sinus. gen dent 1998; 46:160–5 7maloney pl, doku hc.maxillary sinusitis of odontogenic origin. j can dent assoc (tor) 1968;34:591–603. 8poyton hg. maxillary sinuses and the oral radiologist. dent radiogrphotogr 1972; 45:43–50. 9ziegler cm, woertche r, brie j, hassfeld s. clinical indications for digital volume tomography in oral and maxillofacial surgery. dentomaxillofacradiol 2002;31:126–30. 10bremke m, sesterhenn am, murthum t hail aa, kadah ba, bien s, werner ja. 2008 11nishimura t, iizuka t. evaluation of odontogenic maxillary sinusitis after conservative therapy using ct and bone spect.clin imaging 2002;26:153–60 12beaumont c, zafiropoulos gg, rohmann k, tatakis dn. prevalence of maxillary sinus disease and abnormalities in patients scheduled for sinus lift procedures. j periodontol 2005;76:461–7. 13guerro me, jacobs r, loubele, schutyser f, suetens p, van steenberghe d. state of the art on cone beam ct imaging for preoperative planning of implant placement. clin oral investig 2006;10:1–7. 14soikkonen k, ainamo a. radiographic maxillary sinus findings in the elderly. oral surg oral med oral pathol oral radiolendod 1995;80: 487–91. 15ilze d, ligija k, peteris a, gints k, andris b. radiographic assessment of findings in the maxillary sinus using cone-beam computed tomography.stomatologija baltic dental and maxillofac j 2013; 15:4. 16rega i, susa th, leles c, mendonca e. accuracy of maxillary sinus abnormalities detected by cone beam ct in asymptomatic patient. bmc oral health 2012; 12:30 17janner sfm, caversaccio md, dubach p, sendi p, buserd,bornstein mm. characteristics and dimensions of the schneiderian membrane: a radiographic analysis using cone beam computed tomography in patients referred for dental implant surgery in the posterior maxilla. clin oral impl 2011; 18gorgulu o, ozdmir s, canbolat ep, sayar c, olgun mk, akbas y. analysis of the roles of smoking and allergy in nasal polyposis. ann otolrhinollaryngol2012; 121(9):615-9. aysar f.doc j bagh college dentistry vol. 25(2), june 2013 the value of lateral oral diagnosis 54 the value of lateral cephalometric image in sex identification aysar razzaq ali, b.d.s. (1) lamia h. al-nakib, b.d.s., m.sc. (2) abstract background: determination of sex and estimation of stature from the skeleton is vital to medicolegal investigations. skull is composed of hard tissue and is the best preserved part of skeleton after death, hence, in many cases it is the only available part for forensic examination. lateral cephalogram is ideal for the skull examination as it gives details of various anatomical points in a single radiograph. this study was undertaken to evaluate the accuracy of digital cephalometric system as quick, easy and reproducible supplement tool in sex determination in iraqi samples in different age range using certain linear and angular craniofacial measurements in predicting sex. materials and method the sample consisted of 113of true lateral cephalometric radiographs for adults with age range from 22-43 years old (51 males, 62 females), using certain linear and angular craniofacial measurements with the aid of computer program “autocad 2007” results: the eleven parameters measured for males and females when compared are statistically significantly different. all cranio-cephalometric measurements gave overall predictive accuracy of sex determination by discriminant analysis (86.7%). the stepwise selection method gave overall predictive accuracy of sex determination by discriminant analysis (85.8%). age showed no statistical difference among the studied age range except for the distance from mastoid to frankfort plane. conclusion: the lateral cephalometric measurements of craniofacial bones are useful to support sex determination of iraqi population in forensic radiographic medicine. keyword: sex determination, lateral cephalgram, discriminant analysis, craniofacial measurements. (j bagh coll dentistry 2013; 25(2):54-58). introduction sex determination of skeletal remains is part of archaeological and many medico-legal examinations. the methods vary and depend on the available bones and their condition. the only method that can give a totally accurate result is the dna technique, but in many cases for several reasons it cannot be used. anthropological measurements of the skeleton and the comparison with existing standard data must then be applied and may help to differentiate between male and female remains. on an individual basis however, sex differences are not always distinctive, but taken collectively they can give a good indication in the majority of cases (1). identification of skeletal and decomposed human remains is one of the most difficult skills in the forensic medicine. sex estimation is an important problem in the identification. if all the bones composing the skeleton are present, sex estimation is not difficult , as can be determined with 100% accuracy. this estimation rate is 98% in existence of pelvis and cranium, 95% with only pelvis or pelvis with long bones and 80-90% with only long bones. however, in explosion, warfare and other mass disasters like aircraft crashes, identification and sex determination are not very easy (2,3). (1) m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. ceballos and rentschler in 1958(4) compared the posterio-anterior radiographs of 100 males and 100 females adult skulls and claimed 88% success in sexing the skulls. kaptanoglu and ozedmir study in 2001(5) about sex determination found that the accuracy rate of the thickness of the skull was found to be 74.7% in male and 67.6% in female. the present study is an attempt to derive a discriminant function to determine sex and to evaluate the accuracy of digital cephalometric system as quick, easy and reproducible supplement tool in sex identification in iraqi samples in different age range and to establish the effectiveness of certain linear and angular craniofacial measurements in predicting sex. materials and method for this study, total 113 normal healthy adults originating from iraqi origin, comprising of 51 males and 62 females, their ages ranging between 22-43 years old were selected at the oral diagnosis and orthodontic departments, college of dentistry/ university of baghdad, in addition to cephalometric images saved in archives (pro and retrospective study). to ensure the selection of normal healthy person, detailed history of each patient was taken, no history of abnormal habits, no apparent facial disharmony or cleft lip and palate, no history of orthodontic, orthopedic or facial surgical treatment, symmetrical faces with normal j bagh college dentistry vol. 25(2), june 2013 the value of lateral oral diagnosis 55 occlusion skeletal class i, anb angle between 2-4 degrees (6). images of good quality had the clearest reproduction of lateral anatomical cephalometric landmarks depiction a reference ruler on the cephalostat for exact measurement of the magnification factors. new participants were carefully informed about the aim and the method of investigation of the study and they were free to accept or refuse. all the radiographs were taken in the oral diagnosis, college of dentistry, baghdad university, using dimax3 digital x-ray unit system machine (finland) , the correct exposure parameters for the individual being x-rayed were selected according to the user's manual (2004)(7) as shown in table (1). table 1: lateral view exposure values (user's manual, 2004). patient kv value ma value adult female or small male 68 5 adult male 70 5 large adult male 72 5 all lateral cephalometric image were analyzed by auto cad program (version 2007) to identify cephalometric points and plane landmarks when image was imported to autocad program , it was appeared in the master sheet on which the points were determined, and measurements were obtained, after correction of magnification. the magnification was corrected by multiplying the readings by the magnification factor which was obtained as a ratio between the real distance measurements for a scale and the distance measurements for the same scale from radiographic image; after that the measurements were saved on an excel sheet with their records in degrees for angular measurement and in millimeter for linear measurements. the cephalometric bony landmarks, which were used in this study, include the following: glabella (g) most anterior point in the midsagittal plane between the superciliary arches, basion (ba)lowest point on the anterior rim of the foremen magnum in the median plane , anterior nasal spine (ans) it's the tip of the bony anterior nasal spine in the median plane , nasion (n) the most anterior point on the naso-frontal suture in the median plane, menton (m) the lowest point on the symphyseal shadow of the mandible seen on a lateral cephalogram, opisthocranion (op)most prominent point of the occipital bone in the midline , mastoidale (ma)lowest point of the mastoid process, sella (s) the midpoint of the hypophysial fossa , v1 and v2 upper and lower parameter of the frontal sinus cavity respectively cephalometric planes used in measurements sn plane (sella-nasion): it is the anterior posterior extent of anterior cranial base , frankfort horizontal plane (fh): it is a horizontal plane running between porion and orbitale. lines used in the measurements g–op: maximum length of skull ,the distance was obtained from glabella (g)to opsithocranium (op), fsht: (v1–v2) frontal sinus height, the distance from upper and lower parameter of frontal sinus cavity, ba–n: length of cranial base, the distance was obtained from basion (ba) to nasion(n), n–ans: upper facial height, the distance was obtained from nasion(n) to anterior nasal spine(ans), n–m: total face height, the distance was obtained from nasion (n) to menton(m), ba–ans: the distance was obtained from basion to anterior nasal spine , ma–sn: perpendicular distance was obtained from mastoidale to sn plane, ma–fh: perpendicular distance was obtained from mastoidale to fh plane. angle used in measurements: ba-n-m angle: the angle which between basion & nasion& menton, m-n-ans angle: the angle which between menton & nasion & anterior nasal spine, s-n-m angle: the angle which between sella & nasion & menton. initially mean values, standard deviations and co-efficient of variation were calculated for all the variables, the values derived were compared between both the sexes using student's t-test. discriminant analysis was used to test the performance of all the 11 measurements and indices (used together in a univariate modelling) in differentiating male from female sex. the resulting discriminant score (d score) from using the equation could be used in predicting sex based on cranial measurements and indices. the stepwise selection method of discriminant analysis was used next to select from the tested 11 measurements only those that contribute to the bulk of discrimination power of the model. roc analysis on the other hand is a univariate analysis testing the discrimination power of each measure when used alone. a multiple linear regression model was used to study the net and independent effect of sex after adjusting for age on each of the 11 quantitative outcome (dependent) variables. the performance characteristics (validity) of a test or criteria, include among others: sensitivity, specificity, positive predictive value and negative predictive value. j bagh college dentistry vol. 25(2), june 2013 the value of lateral oral diagnosis 56 results the mean values for males were significantly greater than those for females for all linear measurements and two angular measurements except for angle degree (m_n_ans), the discriminant function was highly significant and therefore all the 11 variables were useful in determination of sex, as shown in table (2). table 2: mean, standard deviation, standard error, p (t-test), sexual dimorphism for 11 variables variables female male p (t-test) sexual dimorphism (% difference compared to females) mean sd se mean sd se (g_op)mm 174.2 8.5 1.08 184.4 8.3 1.17 <0.001 5.9 % (v1_v2mm 26.8 5.7 0.72 30.1 4.6 0.64 0.001 12.3 % (ba_n) mm 98.1 5.1 0.64 105.1 6.4 0.9 <0.001 7.1 % (n_ansmm 50.5 3.3 0.41 54.2 4.1 0.57 <0.001 7.3 % (n_m) mm 113.2 6.2 0.79 122.8 6.7 0.93 <0.001 8.5 % (ba_ans)mm 93 5.5 0.7 99.4 6 0.84 <0.001 6.9 % (ma_sn) mm 36.2 4.8 0.61 40.6 5.3 0.74 <0.001 12.2 % (ma_fh) mm 25.6 4.1 0.52 27.3 4.1 0.58 0.03 6.6 % angle degree (ba_n_m) 58 2.6 0.32 59.2 3.1 0.43 0.028 2.1 % angle degree (m_n_ans) 11.2 2.4 0.3 9.9 2.5 0.34 0.005 -11.6 % angle degree (s_n_m) 76.3 3 0.38 78.2 3.9 0.55 0.004 2.5 % all the 11 cephalometric measurements and indices were used together in discriminant model to differentiate between males and females. the resulting equation was statistically significant and able to predict sex with overall accuracy of 86.7%.the total facial height distance ranked first in its predictive power followed by the length of cranial base distance, the maximum length of skull, linear distance (ba_ans), upper facial height distance, linear distance (ma-sn), frontal sinus height distance, angle degree (s-nm), the angle degree (m-n-ans). the angle degree (ba-n-m) and the linear distance (mafh) are least contribution to the model. the resulting discriminant score (d score) from applying the specific value of each measurement and index in the equation could be used in predicting male sex if d score ≥0.104 (cutoff value) otherwise its labeled as female sex. the stepwise selection method was used next to select from the total 11 tested measurements, only those contributing to the major part of discrimination power of model. only 3 of 11tested variables were enough to provide a statistically significant equation with an overall predictive accuracy of 85.8% which is almost near to the previously reported discriminant model containing all 11 measurements .these variables were in order of importance, starting from the most important:the total facial height ; followed by; the length of cranial base ; and finally; (s-n-m) angle as shown in table (3, 4). table 3: discriminant model for 11 selected measurements when used to discriminate between male and female sex. variables rank according to importance (discriminating power) linear distance (n_m) mm 1 linear distance (ba_n) mm 2 linear distance (g_op) mm 3 linear distance (ba_ans) mm 4 linear distance (n_ans) mm 5 linear distance (ma_sn) mm 6 linear distance (v1_v2) mm 7 angle degree (s_n_m) 8 angle degree (m_n_ans) 9 angle degree (ba_n_m) 10 linear distance (ma_fh) mm 11 table 4: discriminant model for 11 elected measurements when used to discriminate between male and female sex. the stepwise selection method was used. variables rank according to importance (discriminating power) linear distance (n_m) mm 1 linear distance (ba_n) mm 2 angle degree (s_n_m) 3 j bagh college dentistry vol. 25(2), june 2013 the value of lateral oral diagnosis 57 discussion in establishing the identity of sex from a defleshed skull, lateral cephalograms and pa radiographs assumes a pre-dominant role, as they can provide architectural and morphological details of the skull, thereby revealing additional characteristics and multiple points for comparison (8). in sexing a skull the initial impression often is the deciding factor, a large and robust skull is generally a male; a small and gracile skull is of a female (9,2), this subjective approach of sexing skull by inexperienced individual may produce misleading results. however methods based on measurements and morphometry are accurate and therefore can be used in determination of sex from skull. next to pelvis, skull is the most easily sexed portion of the skeleton, but the determination of the sex from the skull is not reliable until well after puberty (9,8). in the present study 11 cephalometric measurements were used in discriminant function analysis and they provided very good sex discrimination in iraqi subjects of known sex. lazic et al (10) performed various measurements on 64 skulls by electron gilding meter goniometer to study basic craniometric and skeletotopic characteristics of facial skeleton and hard palate in osteologic samples and found that the average length of skulls was (173.27±7.355)mm ;all the male skulls had higher values than the females skulls and their ratio was 175.59:170.94 mm., these values were lower than that of the current study because of different methodology used and as a result of the racial anatomic variety in the studied samples. zavando et al(11) performed sex determination from lineal dimensions in a sample of human skulls collection belonging to the universidade federal de sao paulo (unifesp), the sample comprised 149 males skulls with a mean of age of 43.41 years old and 77 females skulls with a mean of age of 38.19 years old. this sample considered skulls from individuals with white, brown, and black skin, the means of all the analyzed lineal dimensions were larger in the men skulls than in the women skulls. nevertheless g -op, na-pr (nasion – prosthion), zi-zi (bizagomatic), and na-ans were statistically significant with p <0.05. the result of this study showed the skull of human exhibits anatomic variability between sexes. all the 11 cephalometric measurements and indicies are used together in discriminant model to differentiate between males and females. the resulting equation was statistically significant and able to predict sex overall accuracy of 86.7%. altayeb et al (12) found that males had statistically significantly greater measurements than females. complete crania showed a high degree of sexual discrimination with 83.6% success for recent northern sudanese for all variables and using stepwise discriminant function analysis only three variables were selected as the best discriminant between sexes was the glabello-occipital length being the most dimorphic followed by the basion-nasion length and basion-bregma height 81.8% accuracy was obtained. sumati et al (13) found that four variables of mastoid process sexed with 76.6% accuracy of the sample while stepwise discriminant function analysis, mastoid length was found to the best determinant that alone correctly sexed the sample with an accuracy of 66.7%. while the current study the first ranked in discrinimt power was (n-m) with 87.3% diagnostic accuracy and this due to different method was used (magnification factor), different populations and geographical regions. the success rates obtained in this study are generally similar to those obtained in various parts of the world e.g. south africans, cretan, white and black americans (82-89%), and japanese who showed 84.1% for crania and mandible; but they are less than those obtained in indians (90%), taiwanese (100%) and chinese (96.7%); and also sex prediction using the complete cranium was better than using fragmentary crania (13). from the above study, following conclusions were made. all selected linear and angular craniofacial measurements shown significant statistical differences between males and females and give strong predictive accuracy of sex determination by discriminant analysis, the stepwise selection method which choose only three from eleven parameters in order of importance, starting from the most important: the total facial height ;followed by; the length of cranial base ;and finally; (s-n-m) angle and give overall predictive accuracy of sex determination nearly equal to all eleven craniofacial parameters by dicreminant analysis, male sex was associated with statistically significant positive association with all the linear measurements and 2 angular measurements compared to females after adjusting the possible age effect and the effect of male sex was negative (reduction) on (m-nans) angle, (ma-fh) linear measurement in which the positive effect of male sex was small and failed to reach statistical significance after j bagh college dentistry vol. 25(2), june 2013 the value of lateral oral diagnosis 58 adjusting for the obviously important positive effect of increasing age, the age effect in the all the remaining 10 indices evaluated was not statistically significance during the age interval of 22-43 included in the current study. references 1. mughal ia, saqib as, manzur f. mandibular canine index (mci): it’s role in determination gender. professional med j 2010; 17(3): 459-63. 2. krogman wm, iscan my. the human skeleton in forensic medicine. 2nd ed. springfield illinois: charles thomas publisher; 1986. pp: 189-243. 3. jones g. canadian forces dental services play major role in swissair disaster aftermath. cjmrt 1991; 31(2): 80-3. 4. ceballos jl, rentschler eh. roentgen diagnosis of sex based on adult skull characteristics. comparison study of cephalometry of male and female skull films (frontal projection). radiology 1958; 70: 55–61. 5. kaptanoglu k, ozedemir b. gender dimorphism from skull thickness: a preliminary study (in turkish). annual forensic medicine meeting proceeding, istanbul 2001; 153-156. 6. foster td. a textbook of orthodontics. oxford: blackwell scientific publication; 3rd ed, 1990. p: 1817. 7. user's manual of promax x-ray with dimax3. publication number 10007367. version 7. published 2004; 01. 8. biggerstaff rh. craniofacial characteristics as determinants of age, sex and race in forensic dentistry. dent clin north am 1977; 21(1): 85–97. 9. giles e. sex determination by discriminant function analysis of the mandible. am j phys anthropol 1964; 22: 129–36. 10. lazić b, keros j, komar d, ćatović a, azinović z, bagić i. assessment of craniometric and skeletotopic characteristics of the facial skeleton and palate in a population of north-west croatia. acta stomatol croat 2000; 34(2): 143-7. 11. zavando mda, suazo gic, smith rl. sexual dimorphism determination from the lineal dimensions of skulls. int j morphol 2009; 27(1): 133-7 (ivsl). 12. altayeb aa, hassan ah, mohamed ah. sex determination from cranial measurements in recent northern sudanese. khartoum medical j 2001; 4(1): 539 – 47. 13. sumati, patnaik vvg, ajay p. determination of sex form mastoid process by discriminant function analysis. j anati soc india 2010; 59(2): 222-8 (ivsl). munad.doc j bagh college dentistry vol. 26(4), december 2014 in vivo plaque count pedodontics, orthodontics and preventive dentistry175 in vivo plaque count of streptococcus mutans around orthodontic brackets bonded with two different adhesives munad j. al-duliamy, b.d.s., m.sc. (1) abstract background: the prevention of the enamel demineralization at the periphery of the brackets is a significant challenge to orthodontic professionals. the aim of this clinical study was to compare the streptococcus mutants count in the plaque surrounding two orthodontic adhesive types, fuji ortho lc and enlight (ormco). materials and methods: a total of 13 patients (7 males and 6 females) needing fixed orthodontic appliance therapy were participated. a split mouth technique was followed with appliances bonded by two orthodontic adhesive types, fuji ortho lc and enlight (ormco). saliva was collected before placement of appliances (t0) and again at three weeks (t1) and six weeks (t2) after placement of appliances. plaque was collected from areas adjacent to brackets and buccal tubes at three weeks (t1) and six weeks (t2) after placement of appliances. the numbers (colony-forming units) of streptococcus mutans were determined with the side-specific modified strip-mutans. results: no significant modification in the number of streptococcus mutans cfu in saliva was observed at both time intervals (t1) and (t2) after placement of appliances. the number of streptococcus mutans cfu in plaque at both time intervals (t1) and (t2) was statistically lower in sites adjacent to fuji ortho lc than in those adjacent to enlight (ormco) adhesive. conclusion: plaque surround brackets and tubes bonded with fuji ortho lc adhesive harbor less streptococcus mutans and this will aid in prevention of enamel demineralization. keywords: plaque, streptococcus mutans, orthodontic adhesive. (j bagh coll dentistry 2014; 26(4):175-179). الملخص كان الھدف من ھذه الدراسة السریریة . الوقایة من ظاھرة انتزاع معادن مینا السن حول اجزاء جھاز تقویم االسنان الثابت یمثل تحدیا كبیرا للمھنیین في اختصاص تقویم األسنان: خلفیة fuji ortho lcو enlight (ormco) :المثبتة الجھزة تقویم االسنان وھما لمقارنة اعداد بكتریا العقدیة الطافرة في المادة الجیریة المحیطة بنوعین من المواد تم تثبیت اجھزة االسنان بواسطة المادتین .من الذین یحتاجون إلى عالج تقویم االسنان بواسطة األجھزة الثابتة) إناث 6ذكور و 7(مریضا 13شارك في البحث :المواد والطرق وقد تم جمع عینات اللعاب قبل وضع أجھزة التقویم ومرة اخرى بعد ثالث اسابیع ومن ثم ستة اسابیع . احد بقسمة الفم الى قسمین كل مادة تستخدم في قسمالالصقتین في فم المریض الو ثالثة اسابیع ومن ثم بعد ستة اسابیع من وضع أجھزة تقویم وقد تم جمع المادة الجیریة من المناطق المحیطة الجھزة التقویم المثبتھ على االسنان بعد. بعد وضع اجھزة تقویم االسنان لبكتریا العقدة الطافرة في عینات اللعاب والمادة الجیریة ) الوحدات المكونة للمستعمرة(وتم حساب عدد . االسنان و كان عدد مستعمرات بكتریا العقدة الطافرة في المادة الجیریة . ة فترات البحثلم یالحظ أي تغیرات ذات اھمیة احصائیة في عدد العقدیة الطافرة في عینات اللعاب في كاف :النتائج enlight ormcoاعداد تلك المستعمرات في المادة الجیریة المحیطة بمادة ال یفوق fuji orthoال المحیطة بمادة یساعد في الوقایة من ظاھرة انتزاع معادن مینا لتثبیت اجھزة تقویم االسنان الثابتة fuji ortho ان استخدام مادة ال :االستنتاج المادة الجیریة، العقدیة الطافرة، المادة المثبتة لجھازتقویم األسنان: الكلمات الرئیسیة introduction biofilm formation on orthodontic adhesives is a serious clinical problem, as it leads to enamel demineralization around fixed orthodontic appliances, often leaving white spot lesions after their removal (1). clinical observation indicates that the most common site for bacterial adhesion and biofilm formation is at the bracket-adhesiveenamel junction, an area that is difficult to clean by daily brushing. furthermore, the surface of an orthodontic adhesive is often rough, with a gap of around 10 µm at the adhesive enamel interface due to polymerization shrinkage (2,3). streptococcus mutans has been considered as a major cariogenic bacterium involved in the initiation and progression of dental caries. the correlation between s. mutans counts in saliva or dental plaque and the incidence of dental caries has been postulated (5). placement of fixed orthodontic appliances leads to an increase in the level of streptococcus mutans within dental plaque (6). orthodontic adhesives have a higher streptococcus mutans -retaining capacity than bracket materials (7). (1)assistant lecturer. department of dentistry, iraqi university. for this reason, many studies have examined the antibacterial properties of orthodontic adhesives or the effect of antibacterial agents incorporated into orthodontic adhesives. enamel demineralization is a commonly recognized complication of orthodontic treatment with a fixed appliance. this enamel demineralization is principally streptococcus mutans–associated disease (8). it is caused by organic acids produced by mutans streptococci (9). preventing these lesions is an important concern for orthodontists because the lesions are unaesthetic, unhealthy and potentially irreversible (10). in this sense, one of the effective methods for preventing enamel demineralization is to use orthodontic adhesives resistant to bacterial accumulation (11). composite and glass ionomer are the two main classes among many commercially available orthodontic bonding adhesives. their physical properties, surface characteristics, and fluoridereleasing capacities have been extensively studied; their biologic properties associated with adhesion of cariogenic streptococci also have been investigated. differences in bacterial adhesion to the different orthodontic adhesives may be expected because of their different j bagh college dentistry vol. 26(4), december 2014 in vivo plaque count pedodontics, orthodontics and preventive dentistry176 characteristics and the release of incorporated fluoride (9,12). however, the effect of fuji ortho lc glass ionomer adhesive on the plaque streptococcus mutans has not been clinically compared with that of enlight (ormco) composite adhesives. therefore the aim of the present prospective clinical study was to compare the streptococcus mutans counts in the plaque adjacent to fuji ortho lc -bonded brackets and that adjacent to brackets bonded with enlight (ormco). material and methods volunteer were recruited from patients about to start their treatment with maxillary and mandibular fixed orthodontic appliances in a private orthodontic clinic in baghdad. a total of 13 patients (7 male and 6 female) were participated in this prospective clinical study after signing an informed consent according to the ethics of human research. the inclusion criteria were class i malocclusion cases planned to treat with non extraction, good general health, no detectable carious lesions and faulty restorations, no signs of gingival inflammation before starting the study, no pregnancy, non-smokers, and no pharmacotherapy for at least 3 months. placement of maxillary and mandibular fixed orthodontic appliances were performed using stainless steel trufit bondable maxillary and mandibular buccal tubes (ortho technology company, usa ) on the first molars and stainless steel bionicr bracket system (roth prescription , slot (.020" x .020") ortho technology company, usa) on the maxillary and mandibular incisors, canines and premolars. two commercially available adhesives which is widely used in orthodontic clinic for brackets bonding were evaluated in the present study, resin-reinforced glass-ionomer cement (fuji ortho lc, gc corporation, us) and enlight (ormco, usa) light cured composite resin adhesive. before bonding each tooth was polished, etched and prepared according to manufacturer’s instructions for each product. a split mouth technique was followed with slight modification of previous method by mota et al. (13). brackets and buccal tubes were bonded with a fuji (ortho lc) in one side of the dental arch, and with enlight (ormco) in the other side. the bonding material used in each quadrant was: maxillary left = fuji ortho; maxillary right = ormco; mandibular left = ormco; and mandibular right = fuji ortho. excess adhesive was removed from around the margins using dental probe. immediately after bonding, .014" truflex niti arch wire (ortho technology company, usa ) were inserted into brackets and molar tubes slots and elastomere ligatures power sticks™ (ortho technology) were used for arch wire ligation into the brackets. the patients were given oral hygiene instructions, fluoridated toothpaste, and an orthodontic toothbrush, and asked not to use other oral hygiene supplements during the study. analysis of the number of streptococcus mutans was performed by using dentocult sm strip mutans test. the patient previously instructed not to eat or brush their teeth two hours before the sampling appointments. saliva specimens collected before fixed appliance placement (t0), after three weeks (t1) and after six weeks (t2) of appliance placement. plaque specimens collected, after three weeks (t1) when arch wire changed to 0.018-inch niti in all patients and after six weeks (t2) of appliance placement. selected teeth for plaque sampling were isolated with cotton rolls and dried. plaque specimens were collected from the labial surfaces immediately surrounding the orthodontic brackets and buccal tubes with a sterilized dental scaler with the same tip dimensions. the plaque and saliva streptococcus mutans number of colony-forming units (cfu) were determined with the site-specific modified stripmutans® technique (orion diagnostica, finland) according to wallman and krasse (14). for the saliva collection, the participants were instructed to chew a paraffin pellet for 1 minute and to swallow any excess saliva and then press the rough surface of the round-tipped strip from the strip-mutans® kit (orion diagnostica, finland) against saliva remaining on the patient’s tongue and then removed gently from the patient mouth. saliva sample were incubated in a selective culture vial at 37º c for 48 hours in a liquid medium. sampled plaque was immediately spread in a thorough and gentle manner on the rough surface of the square-tipped strip from the kit. strips were allowed to dry for 5 minutes at room temperature and then incubated in a selective culture vial at 37º c for 48 hours in a liquid medium. results were presented as colony-forming units (cfu). the data was analyzed via student paired t test. results the mean value and standard deviation of streptococcus mutans cfu counts in saliva are given in tables 1. there was no significant difference in streptococcus mutans cfu counts in saliva between the values obtained at t0, t1 and t2 as shown in tables 2. j bagh college dentistry vol. 26(4), december 2014 in vivo plaque count pedodontics, orthodontics and preventive dentistry177 regarding the effect of the tested materials on cfu formation, it was observed that cfu means in the plaque adjacent to fuji ortho lc at three and six weeks after the beginning of the treatment was significantly lower than the cfu means in the plaque adjacent to enlight (ormco) as shown in tables 3 and 4. table 1: descriptive statistics of the number (cfu) of streptococcus mutans in saliva at the beginning of treatment (t0) and three weeks (t1) and six weeks (t2) after placement of the appliances table 2: paired t-test for comparison of means for the number (cfu) of streptococcus mutans in saliva obtained at t0, t1 and t2 significance level: p < 0.05 table 3: descriptive statistics of the number (cfu) of streptococcus mutans in plaque for type of material and time of treatment time adhesives mean s.d. (t1) fuji lc 43.308 1.601 ormco 53.769 1.423 (t2) fuji lc 43.154 1.345 ormco 53.615 1.325 table 4: paired t-test for comparison of means for the tested material at three and six weeks after placement of the appliances * significance level: p < 0.05 discussion an essential event in the initiation of enamel demineralization is microbial adhesion to the teeth and/or orthodontic appliances. once adhesion has occurred, cell proliferation can lead to increase of the density of ms in plaque, which is the main cause of enamel demineralization. researches show that one of the most potent risk factors for enamel demineralization on during orthodontic treatment are the orthodontic bonding adhesives. these adhesives have higher retaining capacity of cariogenic streptococci than bracket materials (2,3,10,15) composite resin, frequently used for the fixation of fixed orthodontic appliances has been reported to increase the accumulation of plaque (16), as well as the proportion of mutans streptococci in plaque (17-19). therefore, many modifications and alternate materials have been advocated in an attempt to prevent enamel demineralization from occurring (20). these attempt focused on the control of the cariogenic streptococci adhesion around the brackets as an important factor for the success of orthodontic treatment (10,15) . therefore interest has developed in the use of glass ionomer cements (gics) as orthodontic bonding agents. glass ionomer cements (gics) reduce or prevent decalcification of dental enamel (21). careful selection of the orthodontic bonding agent is one of the important factors for the success of orthodontic treatment. in the present study two commercially available bonding agents have been used resin-reinforced glass-ionomer cement (fuji ortho lc, gc corporation, us), and enlight bonding system (ormco, usa) light cured composite resin adhesive with fluoriderelease. both of them classified as good bonding material regarding their bond strength (22). therefore the present study compared their antimicrobial activity against mutans streptococci in plaque. based on the findings obtained in this study the number of streptococcus mutans cfu in saliva, showed no significant difference at all the experimental periods (t0), (t1) and (t2). this finding inconsistence with mota et al. (13) and may be explained by the suggestion of scheie et al. (23). concerning the number of streptococcus mutans cfu in plaque the present study observed significant reduction in plaque adjacent to brackets bonded with fuji ortho than in plaque adjacent to brackets bonded with enlight (ormco) at (t1) and (t2). this in accordance with the result of mcneill et al. (24) who concluded that glass ionomer cement is more effective than composite resin in preventing white spot formation. another explanation is the result of gorton and featherstone (25) who observed that the resin modified gic showed a cariostatic effect around brackets up to 4 weeks after appliance time mean s.d. (t0) 6.308 1.032 (t1) 6.154 0.899 (t2) 6 0.817 time mean diff. s.d. t-test p-value t0 0.154 0.376 1.477 0.165 t1 t0 0.308 0.630 1.760 0.104 t2 t1 0.154 0.555 1.000 0.337 t2 time adhesives mean diff. s.d. t-test p-value (t1) fuji lc -10.462 2.634 -14.322 0.000 * ormco (t2) fuji lc 2.222 .616 -16.978 0.000 * ormco j bagh college dentistry vol. 26(4), december 2014 in vivo plaque count pedodontics, orthodontics and preventive dentistry178 placement and assumed that this cariostatic effect may be due to the slow fluoride release, which results in the presence of fluoride in enamel or in plaque fluid. on the other hand fishman and tinanoff (26) suggested that the bacterial growth inhibiting effect seemed to be associated with gic acid release. moreover cacciafesta et al. (27) suggested that fuji ortho lc recommended as suitable fluoride-releasing orthodontic adhesives because of their high fluoride releasing capacity than the other adhesives. the significant increase in the number of streptococcus mutans in plaque adjacent to brackets bonded with enlight (ormco) may be explained by the in vitro studies of quirynen et al. (28,29) that showed surface roughness of orthodontic adhesive have a significant impact on the bacterial adhesion and colonization references 1. chin my, busscher hj, evans r, noar j, pratten j. early biofilm formation and the effects of antimicrobial agents on orthodontic bonding materials in a parallel plate flow chamber. eur j orthod 2006; 28: 1–7 2. gwinnett aj, ceen rf. plaque distribution on bonded brackets: a scanning microscope study. am j orthod 1979; 75: 667–77. 3. sukontapatipark w, el-agroudi ma, selliseth nj, thunold k, selvig ka. bacterial colonization associated with fixed orthodontic appliances. a scanning electron microscopy study. eur j orthod 2001; 23: 475–84. 4. fang gu, renate lux, anderson mh, del aguila ma, wolinsky l, hume wr, shi w. analyses of streptococcus mutans in saliva with species-specific monoclonal antibodies. hybridoma and hybridomics 2002; 21(4): 225–232. 5. corbett ja, brown lr, keene hj, horton im. comparison of streptococcus mutans concentrations in non-banded and banded orthodontic patients. j dent res 1981; 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22: 1–14. thekra.doc j bagh college dentistry vol. 27(1), march 2015 effect of different restorative dentistry 92 effect of different palatal vault shapes and woven glass fiber reinforcement on dimensional stability of high impact acrylic denture base [part ii] shnay m. atiyah, b.d.s., h.d.d. (1) thekra i. hamad, b.d.s., m.sc., ph.d. (2) abstract background: change in palatal vault shape and reinforcement of high impact acrylic denture base resin may in turn affect the dimensional accuracy of acrylic resin and affecting the fitness of the denture. the aim of study is to evaluate the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on linear dimensional change and effect of palatal vault shapes on linear dimensional changes of nonreinforced and fiber reinforced high impact denture base acrylic resin material and method: three different palatal vault shapes were prepared on standard casts using cnc (computer numerical control) machine. 60 samples of heat polymerized high impact acrylic resin maxillary denture base were fabricated onto each definitive cast according to manufacturer instruction. samples divided into three main experimental groups represented the three different palatal vault shapes (20 samples for each main group); 1st rounded 2nd u-shaped and the 3rd groups v-shaped. each main group divided into two subgroups (10 samples for each subgroup) representing non fiber reinforced high impact acrylic group as a control and the fiber reinforced high impact acrylic. the measurements of linear dimensional changes of denture bases done at two stages, 1st 24 hour after polymerization and 2nd measurement done after one month storage in distilled water at room temperature. results and conclusion: linear dimensional changes of high impact acrylic denture base not affected by glass fiber reinforcement p-value in all reference lines ≥ 0.05, while topographical change in maxillary vault shapes effects on the linear dimensional changes in woven glass fiber reinforced high impact acrylic denture base p-value < 0.05. key words: high impact acrylic resin, topographical change in vault, woven glass fiber reinforcement. (j bagh coll dentistry 2015; 27(1):92-95). introduction most fractures of maxillary dentures are caused by a combination of fatigue and impact which is reported more in case where maxillary denture base oppose the mandibular natural teeth. the fracture of denture bases when dropped is due to impact force and authors have suggested that repeated flexing from chewing ultimately fatigues the denture in the mouth, in most situations, fractures occur in the midline of the maxillary dentures (1, 2). considering only the strength though the incorporation of fillers like rubber and fibers to heat-cured poly methyl methacrylate resin improves the impact strength and fatigue resistance (3), improvement may in turn affect some of the properties of heat-cured poly methyl methacrylate resin such as dimensional accuracy, dimensional stability, water sorption, and affecting the fitness of the denture (4). highimpact acrylic denture base is made by the heatcured dough method; impact resistance arises from the incorporation of rubber phase into the beads during their suspension polymerization (5), an alternative of the direct addition of elastomers is the use of acrylic/elastomer copolymers. these are, typically, methyl methacrylate-butadiene or (1)master student. department of prosthodontics. college of dentistry, university of baghdad. (2)assistant professor . department of prosthodontics. college of dentistry, university of baghdad. methyl methacrylate-butadiene styrene copolymers which are now available in certain commercial products. (6) dimensional changes caused by water uptake are influenced by the storage period and may compensate the polymerization shrinkage to a certain extent (7). however, after 3 weeks of storage in water, no further significant dimensional changes were observed (8). the aim of study is to evaluate the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on linear dimensional change and effect of palatal vault shapes on linear dimensional changes of non-reinforced and fiber reinforced high impact denture base acrylic resin. materials and methods the study involves preparation of 60 samples of heat polymerized high impact acrylic resin maxillary denture base without artificial teeth onto definitive casts according to the recommendations of manufacturer, the samples divided into three main experimental groups represented the three different palatal vaults shapes (20 samples for each main group); 1st rounded, 2nd u-shaped and the 3rd groups vshaped. each main group divided into two subgroups (10 samples for each subgroup) representing the non-fiber reinforced high impact j bagh college dentistry vol. 27(1), march 2015 effect of different restorative dentistry 93 acrylic group (nf group) and the fiber reinforced high impact acrylic (wf group) (table 1). according to cross-arch forms three casts with different palatal vault shapes were prepared by carving palatal vault of standard cast using cnc machine (computer numerical control). according to anatomical land marks on the upper master cast four reference points (a, b, c, &d) were chosen and prepared using stainless steel round hand piece bur (018 size) (figure 1). point (a) was marked in the center of incisive papillary region, points (b) and (c) were marked in the right and left anterior of maxillary tuberosity, and point (d) was marked in the fovea palatine area (fig.2). denture base without reinforcement preparation for denture base preparation in three different palatal vault shapes in non-fiber reinforced groups (nfo, nfu, and nfv) heat polymerized high impact acrylic powder and liquid was placed in clean, dry porcelain jar and mixed according to manufacturer instruction 10ml/21gm w/p ratio, mixing time 30 second until the monomer and polymer were thoroughly companied, the jar sealed and the mixture left for 5min at room temperature 22c° (±2) until reaching the dough stage. the resin removed from the jar, rolled and packed into the mold of each flask. denture bases with glass fiber reinforcement preparation reinforced high impact acrylic include groups wfo, wfu and wfv, woven type glass fibers were shaped to provide 2mm shorter border than the boundaries of acrylic resin bases (9). also a study recommended that woven glass fiber reinforcement should be placed on the tensile side of the specimens under loading resulted in considerably higher flexural strength and flexural modulus values (10). as result, in clinical situations the fiber reinforcement in complete maxillary denture base should be close to the oral surface of the denture and perpendicular to the midline; so two layers of high impact acrylic resin precisely prepared to encase the woven glass fibers by using 2 and 3mm thickness record base. finally for or all specimens (fiber reinforced and nonfiber reinforced high impact denture base) pressed in the hydraulic press under the load of 100 bar for 5 min. the flasks then placed in clamp and immersed in water bath 70°c for 90 min then the temperature raised to100°c for 30 min according to manufacturer instruction. after curing the flask was left to cool on bench for three hours (11). the samples detached from their corresponding casts and are kept in distilled water to be measured at two periods. the first measurement after one day (24h) then the second measurement done after one month storage in distilled water (12,13), and measurement of linear dimensional change performed by measuring the distance between the reference points as follow ab, ac, ad, and bc (fig. 2) using digital microscope at magnification 10x (fig. 3). table 1: research methodology and grouping of the samples fig. 1: three maxillary casts with different palatal vault shapes each cast with four reference points (a, b, c, and d) fig. 2: denture bases of high impact acrylic with four reference points fig. 3: measurement of linear dimensional changes using digital microscope j bagh college dentistry vol. 27(1), march 2015 effect of different restorative dentistry 94 results mean difference between two measuring interval calculated (24hours and 30 days immersion in distilled water) for all lines, standard deviation was examined for mean difference and subjected to statistical analysis (ttest, and anova test). t-test for linear dimensional changes estimated between nonreinforced and reinforced high impact acrylic in rounded, u-shaped, and v-shape maxillary vault shapes for four lines (table1). anova test for linear dimensional changes affected by change in maxillary vault shape for all lines estimated between reference points in reinforced and nonreinforced high impact acrylic denture base. and when the difference was found to be statistically significant lsd test (least significant difference test) was used for examining differences between each 2 groups. discussion in the present study it was revealed that water storage of 30 days and fiber reinforcement have no significantly effect on the linear distance between references points marked on high impact acrylic resin bases in all experimental groups and this is agreed with others (14-16). anova test revealed highly significant difference in ac line, and significant difference in ad line, while no significant difference in both ab and bc lines (table 2). consequently the difference in oral anatomy appear to have a significant effect to the size of the discrepancy level of fiber reinforced high impact acrylic denture base, and this is accepted with the study of mehmet et al. (17). it may be due to that distribution of linear dimensional changes of fiber reinforced high impact acrylic denture base affected by change in palatal vault shape and not equally distributed. as conclusions 1. linear dimensional changes of high impact acrylic denture bases stored for 30 days in distal water not affected by woven glass fiber reinforcement. 2. topographical changes in maxillary vault shape not effect on linear dimensional change of high impact acrylic denture base. 3. topographical changes in maxillary vault shape effect on linear dimensional changes of woven glass fiber reinforcement of high impact acrylic denture base. table 2: linear dimensional changes in different palatal vault shapes between non-reinforced and fiber reinforced high impact acrylic denture base studied groups no-fiber with fiber t-test no. mean difference ±sd no. mean difference ±sd t sig. (mm) (mm) p-value o -s ha pe ab 10 0.1 0.03 10 0.11 0.03 0.71 0.49 non sig. ac 10 0.1 0.04 10 0.13 0.04 1.53 0.14 non sig. ad 10 0.13 0.04 10 0.12 0.04 0.32 0.75 non sig. bc 10 0.12 0.02 10 0.13 0.02 1.42 0.17 non sig. u -s ha pe ab 10 0.09 0.01 10 0.12 0.05 0.78 0.578 non sig. ac 10 0.21 0.01 10 0.18 0.04 0.77 0.452 non sig. ad 10 0.13 0.03 10 0.15 0.02 0.73 0.475 non sig. bc 10 0.12 0.02 10 0.13 0.02 0.58 0.388 non sig. v -s ha pe ab 10 0.13 0.06 10 0.13 0.03 0.75 0.94 non sig. ac 10 0.29 0.03 10 0.25 0.04 0.38 0.7 non sig. ad 10 0.14 0.04 10 0.19 0.04 1.73 0.09 non sig. bc 10 0.21 0.03 10 0.13 0.02 0.8 0.43 non sig. references 1. johnston ep, nicholls, smith pe. flexural fatigue of 10 commonly used denture base resin. j prosth dent 1981; 46(5):478-483. 2. sung-hun k, david cw. the effect of reinforcement with woven e-glass fibers on the impact strength of complete dentures fabricated with high-impact acrylic resin. j prosth dent 2004; 91:274-80. 3. uma mb, patil kg, nagaraj kr, shweth k. comparative analysis of flexural strength of conventional polymethyl methacrylate resin, high impact resin and glass fiber reinforced resin-an in vitro study. indiana j dental sci 2013; 5(4): 77-9. 4. ranganath lm, shet rgk, rajesh ag, sathish. the effect of fiber reinforcement on the dimensional changes of poly methyl methacrylate resin after processing and after immersion in water: an in vitro study. the journal of contemporary dental practice 2011;12(4):305-317 5. o brain wj. dental materials and their selections. 3rd ed. quintessence publishing co.; 2002. 6. mccabe jf, walls awg. applied dental materials. 9th ed. oxford: blackwell publishing; 2008. j bagh college dentistry vol. 27(1), march 2015 effect of different restorative dentistry 95 table 3: linear changes for all lines in three different palatal vaults shapes (rounded, u-shaped and v-shaped) in non-reinforced and reinforced high impact acrylic denture base studied groups anova no fiber with fiber no. mean difference (mm) f-test p-value no. mean difference (mm) f-test p-value ab o-shape 10 0.1 1.13 0.34 non sig. (p≥0.05) 10 0.11 0.25 0.78 non sig (p≥0.05) u-shape 10 0.1 10 0.12 v-shape 10 0.13 10 0.13 ac o-shape 10 0.01 2.62 0.09 non sig (p≥0.05) 10 0.13 10.7 0.000 highly sig. (p<0.01) u-shape 10 0.21 10 0.18 v-shape 10 0.29 10 0.25 ad o-shape 10 0.13 0.4 0.67 non sig (p≥0.05) 10 0.12 3.86 0.03 sig (p<0.05) u-shape 10 0.13 10 0.15 v-shape 10 0.14 10 0.19 bc o-shape 10 0.11 0.39 0.39 non sig (p≥0.05) 10 0.13 0.01 0.89 non sig. (p≥0.05) u-shape 10 0.12 10 0.13 v-shape 10 0.21 10 0.13 7. miessi ac, goiato mc, dos santos dm, dekon sf, okida rc. influence of storage period and effect of different brands of acrylic resin on the dimensional accuracy of the maxillary denture base. braz dental j 2008; 19: 204-8. 8. peroz i,manke p, zimermann e. polymerization shrinking of prosthetic plastic materials in a variety of manufacturing processes [in german] zwr. 1990; 99: 292-6 9. vallittu pk. flexural strength of acrylic resin polymers reinforced with unidirectional and woven glass fiber. j prosth dent 1999; 81(3): 318-26. 10. katja kn, lippo vl, pekka kv. the static strength and modulus of fiber reinforced denture base polymer. dental materials 2005; 21:421-8 11. al-khafaji am. the effect of four different cooling procedures on the dimensional stability of microwaveactivated acrylic resin at different time interval. j bagh coll dentistry 2011; 23(2): 1-5. 12. duymus zy, yanikoglu nd. influence of a thickness and processing method on the linear dimensional change and water sorption of denture base resin. dent mater j 2004; 23 (1):8-13. 13. vurakkara v. an in-vitro study to evaluate the effect of thickness of different heat cured acrylic denture base materials on water sorption, linear dimensional change and warpage. dissertation, rajiv gandhi university of health sciences, bangalore, karnataka, 2006. 14. rafael lx, marcelo fm, mario ac, simonides c. influence of the deflasking delay time on the displacements of maxillary denture teeth. j appl oral sci 2003;11(4):332-6 15. consani rlx, mesquita mf, consani s, corrersobrinho l, sousa-netomd. effect of water storage on tooth displacement in maxillary complete dentures. braz dent j 2006; 17:53-57. 16. henrik v. the effect of processing methods and acrylic resin on the accuracy of maxillary dentures and toothless denture bases: an in vitro study. quint int 2011; 42 (8): 669-77. 17. mehmet d, demet a, ali riza t, mslim b, halila p. effect of different palatal vault shapes on the dimensional stability of glass fiber-reinforced heatpolymerized acrylic resin denture base material. eur j dentistry 2012; 6:70-8. الخالصھ یھ الطقمدعم االكلریلك عالي الصدمات المستخدم في قاعده الطقم ممكن ان یؤثر على االستقرار البعدي للراتنج االكلریك ویؤثر بالتالي على ثبوت:المقدمھ صدماتھو بحث تاثیر الیاف االزجاج الداعمھ وتاثیر تغییر شكل القحف على االستقرار البعدي للطقم العلوي المصنوع من راتنج االكلریك عالي ال :الھدف من الدراسھ ج ري باس تعمال م اده الس لیكون الخ اص ث م یستنس خ القال ب الح , ت م تحض یرثالثھ اش كال م ن القح ف للف ك العل وي باس تعمال جھ از النحتب الكومبیوتر الرقم ي :المواد والطرق المس تعملھ تقیس التغیر بالبع د الطولی او الخط ي . عینھ قاعده طقم علوي من ماده االكلریك عالي الصدمات تحضر لكل قالب صخري حسب تعلیمات المنشاء 60.قالب صخري60للحصول على ث م ك ل مجموع ھ رئیس یھ تقس م لمجم وعتین , عین ھ 20ولك ل مجموع ھ , -uوح رف v-ح رفوش كل ,تقس م العین ات ال ى ث الث مجموع ات رئیس یھ حس ب ش كل القح ف وھ ي ال دائري . مجموعھ فرعیھاالولى تستخدم االكریلك عالي الصدمات غیر المدعم والمجموعھ الفرعیھ الثانیھ تس تخدم االكلریل ك ع الي الص دمات الم دعم ): عینات لكل مجموعھ فرعیھ 10(فرعیتین یوم من حفظ العینات بالم اء المقط ر بدرج ھ 30ساعھ من الطبخ والمرحلھ الثانیھ للقیاس تتم بعد 24المرحلھ االولى بعد :ات للبعد الطولي تقاس لمرحلتین كل القیاس. بااللیاف الزجاجیھ .حراره الغرفھ باالض افھ تغیی ر ش كل القح ف الی ؤثر عل ى . الیؤثر باالبع اد الخطی ھ ایض ا وتغییر شكل القحف , االبعاد الخطیھ في االكریلك عالي الصدمات التتأثر بالدعم من االلیاف الزجاجیھ:النتائج الراتنج االكریلك عالي الصدمات المدعم بااللیاف الزجاجیھ .ات المدعم بالیاف الزجاجلكن تغییر شكل القحف یؤثر على االبعاد الخطیھ في االكلریلك علي الصدم, تغییر باالبعاد الخطیھ الیتاثرباستعمال الیاف الزجاج الداعم :االستنتاج mohannad.doc j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 36 the effect of led light on depth of cure and microhardness of three types of bulkfill composite mohannad r. a. b.d.s. (1) luma m.s. baban, b.d.s., m.sc. (2) abstract background: to evaluate the iso depth of cure of bulkfill composites and depth of cure which determined by vickers microhardness test. materials and methods: bulkfill resin composite specimens (n=150) were prepared of three bulkfill composite materials (tetricevo ceram, quixfil and sdr) and light cured by flash max p3 for 3, 10, 20 seconds and by wood pecker for 10, 20 seconds respectively, a mold was filled with one of the three bulkfill composites and light cured. the specimens removed from the mold and scraped by plastic spatula and the remaining length (absolute length) was measured which represent the iso depth of cure. after that the specimens were returned into the mold and a microhardness indentation device applied on the specimen and hardness measurements (vickers hardness, vhn) were made at defined distance, beginning at the resin composite that had been closest to the light curing unit (i.e. at the top) and proceeding toward the uncured resin composite (i.e. toward the bottom) on the basis of the vhn measurement, vickers hardness test generated for each group. results and conclusion: iso depth of cure of bulkfill composite materials is time and type of light curing protocol dependent rather than type of material of bulkfill composite while the depth of cure determined by vickers hardness number is material dependent in addition to the light curing protocol. key words: bulkfill composite light curing intensity, depth of cure. (j bagh coll dentistry 2016; 28(1):36-40). introduction adequate polymerization is a crucial factor in obtaining optimal physical performance to improve the clinical performance of resin composite materials (1). however, it is common sense that incomplete polymerization of composite restorations is one of the major clinical problems to be overcome because since inadequate resin activation compromises the restoration both mechanicallydegree of conversion of the resin composite material at increasing distance from the irradiated surface. when restoring cavities with light-curing resin composites, it has therefore been regarded as the gold standard to apply and cure the resin composite in increments of limited thickness has been generally defined as 2mm (2). to achieve successful direct posterior composite restorations, the layering technique was the necessary procedure, requiring competence, proficiency and dexterity, a complex and sensitive technique procedure, one inadequately placed layer could result in an otherwise successful restoration and developing microleakage, causing postoperative sensitivity and leading to secondary caries (3). restoring cavities, especially deep ones, with resin composite increments of 2mm thickness is time-consuming and implies a risk of incorporating air bubbles or contaminations between the increments. (1)master student, department of conservative dentistry, college of dentistry, university of baghdad. (2)professor, department of conservative dentistry, college of dentistry, university of baghdad. thus, various manufacturers have introduced new types of resin composites, so-called "bulk fill" materials, which are claimed to be curable to a maximal increment thickness of 4 mm (tetricevo ceram bulk fill press release. ivoclar vivadent, 2011). the manufacturers claimed that bulk fill materials can achieve a depth of cure of 6 mm (venus bulk fill technical information 2011). although there have been numerous investigations of resin composites cured with leds, the results were varied considerably, probably because of the multiplicity of test configurations, the individual characteristics of each commercial unit and the assumption and approximations integrated into the experimental methodologies. therefore, it is important to obtain additional data on the performance of newly developed leds with light intensities higher than 1000 mw/cm² (4) and biologically. the non-polymerized components may influence the material's chemical stability, increasing it's susceptibility to degradation and leading to release of byproducts, such as formaldehyde and acid methacrylates, which increases the possibility of pulpal adverse reactions and decrease the wear resistance and color stability (1). energy of the light emitted from a light-cured unit decreases drastically when transmitted through resin composite leading to a gradual decrease in the current study was carried on three types of bulk fill composites to evaluate the performance of high power led curing units in comparison to low power led curing unit by using parameter related to photopolymerization j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 37 such as hardness measurement by vickers hardness number (vhn). the depth of cure also determined by the iso 4049 method. hardness measurement is a practical method to indirectly determine degree of conversion for a given resin composite, hardness profiles can be used to alternatively measure depth of cure which determined by the iso 4049 method which was accurately reflected with bulk fill materials when compared to depth of cure determined by vickers hardness number (5). materials and methods three bulkfill resin composites (quixfil, tetricevo ceram and sdr) were used for evaluating the depth of cure by iso and by vickers hardness test (table 1). all bulkfill composites cured by led (flash max p3) with light power density 1600 mw/cm² for 3,10 and 20 seconds respectively and by led (wood pecker) with light power density 800 mw/cm² for 10 and 20 seconds respectively. depth of cure by iso 4049 depth of cure by iso 4049 was performed with re-usable stainless steel molds according to iso 4049:2000. the mold was filled in bulk with one of the three resin bulkfill composite then the top side of the mold was covered with a transparent strip and covered by glass slide which gently pressed under a load of 200 g for 1 minute. the glass slide was removed and the bulkfill resin composite was irradiated from the top through the celluloid strip in a way that the distal end of the light curing device tip was held in contact to the celluloid strip and the center was coincident with the long axis of the specimen. after light curing the specimens were pushed out of the mold and the uncured resin composite material was removed with a plastic spatula. the absolute length of the specimen of cured resin composite was measured with a caliper. the absolute length was divided by two and the latter value recorded as the iso depth of cure. depth of cure by vickers hardness test specimens positioned within the mold and divided in 1 mm incremental depth with the caliper gauge of vickers hardness tester. the hardness test was performed with the digital vickers microhardness tester (th 715) beijing time high technology. the specimens positioned beneath the indenter of the microhardness tester with a load 200g for 15 sec. table 1: resin composites used resin composites type of resin composite (according to manufacturer) maximum increment thickness (mm) (according to manufacturer) shade lot-number quixfil dentsply detrey gmbh konstanz germany posterior restorative 4 universal 1307000933 tetric evoceram bulk fill ivoclar vivadent, schaan, liechtenstein moldable posterior composite for bulk filling technique 4 iva 14900 sdr dentsply caulk, usa posterior bulk-fill flowable base 4 universal 140326 a. assembled b. apart figure 1: the metal mold used in the present study j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 38 results the results show all types of bulkfill composite resin used in the study cured by flash max p3 for 20 sec. pass iso depth of cure while other groups did not pass.the results shows the highest vhn obtained for all types of bulkfill composites with high intensity led (flash max p3) for 20 seconds and the lowest vhn for all types of bulkfill composites with high intensity for 3 seconds. the result also shows that the quixfil bulkfill composite has the vhn value with all types of led light curing protocol at all intervals. anova test used in this study showed high significant difference between groups. after (anova) lsd test revealed that curing with flash max p3 for 20 seconds with all types of bulkfill composites used in this studyhave highest depth of cure iso with high anova analysis shows high significant difference between groups. after (anova) lsd test reveal that flash max p3 for 20 seconds shows the highest microhardness mean values with high significant difference in comparison to other groups of light curing protocol. discussion all types of bulkfill composites (tetricevo ceram, quixfil and sdr) when cured with high intensity (flash max p3) for 20 seconds pass the iso 4049 and can be accepted because it has depth of cure iso 3.5 mm which can be considered as acceptable value because the manufacturer stated that 4 mm depth as an acceptable depth and according to the iso 4049 the depth of cure should be no more than 0.5 mm below the value stated by the manufacturer (iso 4049) (6). the depth of cure was affected by intensity and time of light curing protocol rather than the type of composite material because all composite material (tetricevo ceram, quixfil and srd) for each type of light cure intensity and time show the same depth of cure with for each type of light cure protocol used in this study. therefore, the intensity of light cure and irradiation time are two factors affecting the depth of cure by iso 4049 rather than type of composite material. the high intensity light is necessary for complete polymerization and optimal mechanical properties (7). the polymerization time of 20 seconds and bulk placement up to 4 mm can be recommended (8). there is an adequate polymerization at the depth of 4 mm when bulkfill composite materials are used (9). the doubling of curing time from 10 sec. to 20 sec. led to an average increase in iso depth of cure of 17% (6) significance in comparison to other groups of light curing protocol. vickers hardness number (vhn) for tetricevo ceram bulkfill composite shows that flash max p3 light curing for 20 seconds reveal highest microhardness mean values at all depth intervals followed by flash max p3 for 10 seconds, wood pecker for 20 seconds, wood pecker for 10 seconds and flash max p3 for 3 seconds respectively. anova analysis shows high significant difference between groups. after (anova) lsd test reveal that flash max p3 for 20 seconds shows the highest microhardness mean values with high significant difference in comparison to other groups of light curing protocol. vickers hardness number (vhn) for quixfil bulkfill composite shows that flash max p3 light curing for 20 seconds reveal highest microhardness mean values at all depth intervals followed by flash max p3 for 10 seconds, wood pecker for 20 seconds, wood pecker for 10 seconds and flash max p3 for 3 seconds respectively. anova analysis shows high significant difference between groups as shown in 4. after (anova) lsd test reveal that flash max p3 for 20 seconds shows the highest microhardness mean values with high significant difference in comparison to other groups of light curing protocol. vickers hardness number (vhn) for sdr flowable bulkfill composite shows that flash max p3 light curing for 20 seconds reveal highest microhardness mean values at all depth intervals followed by flash max p3 for 10 seconds, wood pecker for 20 seconds, wood pecker for 10 seconds and flash max p3 for 3 seconds respectively. the bulkfill composite exhibit acceptable to high curing at the deepest portion of 4 mm increment and this showed that bulkfill material met the requirement stipulated in the iso 4049 specification with light curing time 20 seconds(10). there was a decrease in the microhardness mean value of all bulkfill composites used in this study with increasing depth despite the curing protocol. this may be probably attributed to the fact that the light cure intensity was greatly reduced while passing the bulk of the composite resin due to light scattering and absorptions decreasing polymerization effectiveness which lead to decreasing in the microhardness value at every depth of each material cured with different light curing protocol used in this study. the j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 39 microhardness of the composites will reduce with increasing depth of resin as useable curing light intensity and wavelengths are attenuated in the resin and less camphorquinone will be activated(11). the degree of cure of visible light activated dental resin is strictly dependent on the characters of the curing light. a curing light intensity output depends on many factors including light guide, condition of the bulb and battery power (12). energy of the light emitted from a light-curing unit decreases drastically when transmitted through resin composite leading to a gradual decrease in degree of conversion of the resin composite material at increasing distance from the irradiated surface (10). the increase in radiant energy led to a significant increase in microhardness and depth of cure (13). the narrow light spectrum of leds, with a peak intensity at 465-475nm, better fits the absorption peak of camphorquinone where led units should be more efficient in curing activation. where the transmittance of light through composites is wavelength-dependent, where the longer wavelength penetrates composite more deeply than do shorter ones and therefore result in greater curing depth (14). the increased in curing intensity leads to a better conversion rate, assuming that the spectrum of the curing unit, irradiation time and light guide tip diameter are very similar (15). it is better to use high intensity curing mode to improve the physical properties of the composite(16). the light intensity which was lower than 280 mw/cm² could not activate enough initiator molecules to start an adequate reaction (17). the photopolymerization reaction of resin monomer is diffusion controlled after the gel point. therefore after a critical threshold of light intensity-which is necessary for the initiation of the polymerization reaction in a resin compositesthe gel point is reached in the first few seconds and any further increase in light intensity does not significantly enhance the degree of conversion (18). microhardness is dependent on depth of cure which is related to size of the incorporated fillers. the filler particles in the resin based composites scatter light. this scattering effect is increased as the particle size of the fillers in the composite approaches the wavelength of the activating light and will reduce the amount of light that is transmitted through the composite where the material with the smallest filler particle size (0.19-3.3µm) showed the highest values of overall light transmittance for all filler content, where as those with the large sized filler (0.04-10 µm) showed lower light transmittance for all filler contents (19). on the other hand, materials with smaller filler particle size showed sharper angular distribution of diffuse light, indicating that less light scattered within the material. as light scattering is expected to increase with increasing filler particle diameter, the larger scattering causedby larger fillers thus resulted in higher transmittance loss in comparison with materials containing smaller filler particles (19). in addition, other characteristics of the material may have contributed to these results, such as the organic matrix composition, as the polymerization level varies according to the amount of the monomer present in the composite resins (20). the increase in time of cure of flash max p3 and wood pecker from 10 seconds to 20 seconds gives higher microhardness values and greater depth of cure for all types of bulkfill composites while the high intensity with short curing time (flash max p3 for 3 seconds) revealed lowest microhardness value in comparison to other groups of light curing protocol. the increase in irradiation time from 10 to 40 seconds at the surface the hardness increase from 70 to 110 vhn which it is related to increase the degree of conversion and the depth of cure by 1.5 fold due to decrease the irradiation with depth (21). the depth of cure of composite resins is mainly dependent on exposure time of the light source to the composite resin (22). the reduction of photoactivation time when use light curing units with high intensity such reduction of photoactivation time is based on the total radiant exposure concept that a certain dose (irradiance x time) of light is needed to adequately cure a specific material where the high irradiance combined with a short photoactivation time may reduce the degree of cure and the kinetic chain length and increase the frequency of cross-linking (23). the insufficient curing light with very high intensity is likely to happen when too short an irradiation time is used because it is under higher irradiation the life time of free radicals is shorter(24). the bulk fill composites exhibit acceptable to high curing at the deepest portion of a 4 mm increment and this showed that bulk fill materials met the requirements stipulated in the iso 4049 specification even with a light curing time as short as 20 seconds (10). the increased irradiation time resulted in an increase in hardness mean values (25). j bagh college dentistry vol. 28(1), march 2016 the effect of restorative dentistry 40 as conclusion; depth of cure of bulkfill composite by iso 4049 is irradiation condition dependent rather than type of the material while microhardness value of the bulkfill composite is irradiation condition and type of the material dependent. references 1. nogueira jcc, borsatto mc, wanessa christine wc, ramos rp, palma-dibbrg. microhardness of composite resin at different depths varying the post irradiation time. j appl oral sci 2007; 15(4): 1678 1757. 2. sideridou id, achilias ds. elution of unreacted bisgma, tegdma, udma and bis-ema from light cured dental resins composites. j biomed mater res 2005; 74: 617-26. 3. isherwood j. how to simplify composite restorations with ivoclar vivadent tetricevo ceram bulkfill composite.www.dentalproductsreport.com, 2012. 4. christos r, katerina p, nick s and afrodite k. curing efficiency of high intensity light emitting diode (led) devices. j oral sci 2010; 52(2): 187-95. 5. bouschlicher mr, rueggeberg fa, wilson bm. correlation of bottom to top surface microhardness and conversion ratios for a variety of resin composite compositions. oper dent 2004; 29: 698704. 6. rueggeberg fa, looney s, oxford a, hassan z. variation comparison of depth of cure between scraping and chemical removal methods. miami, florida 2009. 7. biradar bc, chandurkan am, metgud ss. comparative evaluation of the effect of light intensity curing cycle of qth and led lights on microleakage of cl v composite. 2014; 8(3): 221-4. 8. czasch p, ilie n. in vitro comparison of mechanical properties and degree of cure of bulk fill composites. 2013; 17(1):227-235. 9. platt ja, el-damanhoury m. polymerization shrinkage stress kinetics and related properties of bulk fill resin composite. 2013; 39(1):1-9. 10. knezevic a, zeljezic d, kopjar n, tarle, z. influence of curing mode intensities on cell culture cytotoxicity/ genotoxicity. am j dent 2009; 22: 438. 11. dasilva em, poskus lt, guimaraes jg, de araujo lima barcellos a, fellows ce. influence of light polymerization modes on degree of conversion and cross link density of dental composites. j mater sci mater med 2008; 19: 1027-32. 12. calheiros fc, darnoch m, rueggeberg fa, braga rr. influence of irradiant energy on degree of conversion, polymerization rate and shrinkage stress in an experimental resin composite system. dent mater 2008; 24: 1164-8. 13. soh ms, yap au. influence of curing modes on crosslink density in polymer structures. j dent 2004; 32: 321-6. 14. jandt kd, mills rw, blackwell gb, ashworth sh. depth of cure and compressive strength of dental composites cured with blue light emitting diode. dent mater 2000; 16(1):41-7. 15. han kk, kown ty, bagheri r, kim yk. cure mechanism in materials for use in esthetic dentistry. 2012; 3(1): 3-16. 16. chanddurkan am. evaluation of qth and led light curing lights on microleakage. 2014; 8: 221-224. 17. watts dc. reaction kinetics and mechanics in photopolymerization network. dent mater 2005; 21: 27-35. 18. arikawa h, kanie t, fujii k, takahashi h, ban s. effect of filler properties in composite resin on light transmittance characteristics and color. dent mater 2007; 26(1): 38-44. 19. filho ac, ribeiro bci, boaventura jmc, britogoncalves j, rastelli a, bagnato vs, saad rc. degree of conversion of nanofilled and microhybrid composite resin photoactivated by different generations of leds. 2012; 20(2): 212-7. 20. leveque p, leprince jg, bebelman s devaux j, leloupg, gallez b. spectral spatial electron paramagnetic resonance imaging as a tool to study photoactive dimethacrylate based dental resins. j magnetic resonance 2012; 220: 45-53. 21. schattenberg a, lichtenberg d, stender e, willershauser b, ernst cp. minimal exposure time of different led curing devices. dent mater 2008; 24, 1043-9. 22. cavalcante lm, schneider lfj, consani s, ferracane jl. effect of co-initiator ratio on the polymer properties of experimental resin composite formulated with camphorquinon and phenylpropanedione. dent mater 2009; 25: 329-75. 23. busemann i, lipke c, schattenberg a. shortest exposure time possibility with led curing light. 2011; 24(1): 37-44. 24. allesandra nr, ricardo sn, jose rc, marcelo f, vaderlei s b. effect of different light cure techniques on hardness of a microhybrid dental composite. braz dental sci 2014; 17(1): 45-53. http://www.dentalproductsreport.com j bagh college dentistry vol. 28(4), december 2016 evaluation of mandibular pedodontics, orthodontics and preventive dentistry 168 evaluation of mandibular third molar position by using space-width ratio method istabraq m. mohamed, b.d.s. (a) nidhal h. ghaib, b.d.s., m.sc. (b) abstract background: the prediction of changes in the mandibular third molar position and eruption is an important clinical concern because third molar retention may be beneficial for orthodontic anchorage. the aims of this study were to assess the mandibular third molar position by using medical ct scan and lateral reconstructed radiograph and evaluate gender differences. materials and methods: the sample of present study consisted of 39 patients (18 males and 21 females) with age range 11-15 years who were attending at al-suwayra general hospital/ the computerized tomography department. the distance from anterior edge of ramus to distal surface of permanent mandibular second molar and mesio-distal width of developing mandibular third molar were measured in both three dimensional volumetric and two dimensional ct derived lateral images. the statistical analyses included: means, standard deviations. paired t-test was used to compare between the two methods and independent t-test was used in verifying the genders difference. results: the results showed that there was high significant method difference between 3d ct and 2d image and gender differences were observed in values of linear measurements of present study, as males showed higher mean values than females. conclusion: there is high accuracy of measurement on ct images, so c.t. scan is advisable during the diagnosis and treatment plan of orthodontic cases. key words: mandibular third molar, space width ratio method. (j bagh coll dentistry 2016; 28(4):168-171) introduction a wisdom tooth or third molar is one of the three molars per quadrant of the human dentition. it is the most posterior of the three. wisdom teeth generally appear between the ages of 17 and 25 (1). the mandibular third molar has the greatest variability in development, morphology (shape and size), eruption and occlusion (2). there is great correlation between the eruption of mandibular third molar and malocclusion, like crowding of the lower anterior teeth which occur as a result from the mesial force that exerted from the mandibular third molar. presence or absence of mandibular third molars in patient is relevant to orthodontic treatment planning (3). orthodontic therapy in maxillary and mandibular arches may need distal movement of both first and second molars by either tipping or translation, which may result in impaction of third molar. so to avoid impaction of third molar and to facilitate retraction, it is advisable in some cases to remove third molars before starting teeth retraction (4). there are many indications for retention of unerupted mandibular third molar, when there are medical reasons to avoid surgery if there is a likelihood of subsequently losing the second molar because of a large restoration, periodontal disease, or extensive caries, other indications is in (a)m.sc. student. department of orthodontics. college of dentistry, university of baghdad. (b)professor. department of orthodontics. college of dentistry, university of baghdad. orthodontic patients in whom four premolars have already been extracted and removal of third molars would reduce the dentition by a total eight teeth. finally, there may be instance in which the orthodontist may need these teeth for anchorage (5). in an attempt to predict the probability of third molar eruption, many studies have been done; most of them using dissected skulls, lateral cephalic radiographs or orthopantomograph (6). the aims of this study were to assess the mandibular third molar position by using medical ct scan and lateral reconstructed radiograph and evaluate gender differences. materials and methods sample the sample of the present study consisted of 39 patients (18 males and 21 females with mean age of 13 years) who were attending at al suwayra general hospital/ the computerized tomography department, who met a special selective criteria were selected. the following criteria were used in the selection of the total sample: 1. iraqi arab subject their age from 11-15 years. 2. normal general health status, by taking medical history from parents. 3. normal skeletal relationship assessed in three planes of space (7). 4. no history of dentofacial deformities, pathologic lesions in the jaws or facial trauma. http://en.wikipedia.org/wiki/molar_(tooth) http://en.wikipedia.org/wiki/commonly_used_terms_of_relationship_and_comparison_in_dentistry#quadrant http://en.wikipedia.org/wiki/human_tooth http://en.wikipedia.org/wiki/posterior_(anatomy) http://en.wikipedia.org/wiki/human_tooth j bagh college dentistry vol. 28(4), december 2016 evaluation of mandibular pedodontics, orthodontics and preventive dentistry 169 5. full set of teeth with developing mandibular third molar. 6. no congenital missing or supernumerary teeth 7. normal overbite and over jet (2-4 mm) measured by sliding caliper (dentarum ® – germany). 8. no shifting in dental midline. 9. mild crowding (not more than 2 mm) measured by sliding caliper (dentarum ® – germany). 10. mild spacing (not more than 2 mm) measured by sliding caliper (dentarum ® – germany). 11. no previous orthodontic treatment like habits breaker or chin-cap. methods for every patient in the sample; a clinical examination and computerized tomographic imaging had been done using brilliance™ 16 ct (philips c, netherland), then the ct images were collected from the workstation of the ct unit of and the imaging data were analyzed with the software provided by the manufacturer. firstly, the mesio-distal crown dimension of mandibular 1st molar was measured clinically using vernier. this is done to compare it with the measurements obtained from the 3d and 2d images. on each image, the distances from the anterior border of ramus to distal surface of the permanent mandibular second molar (ab) and the mesiodistal width of developing mandibular third molar (cd) were measured. the ratio of ab/cd (8) was used to determine the lower third molar position. olive and basford (8) founded that if the ab/cd ratio equaled or more than 1, the space was enough for eruption of mandibular third molar and if it was less than 1, the space is not enough. statistical analysis all the data of the sample was subjected to computerized statistical analysis using spss version 19 for windows xp. the statistical analysis included: a. descriptive statistics  means.  standard deviations.  statistical tables. b. inferential statistics paired sample t-test: it was used to compare the measurements between the ct and the reconstructed lateral view. independent sample ttest was used to verify the gender differences. results table 1 and 2 showed the descriptive statistics and gender difference of the measured variables in 3d and 2d images. generally, the mean values were slightly higher in males than females with a significant gender difference for the mesio-distal width of developing mandibular third molar. comparing the two methods of measurements revealed highly significant difference between them in all measurement with 3d measurements slightly larger than 2d (table 3). . a high significant difference was found between the direct clinical measurements and the 2d image and between the 3d and 2d methods with the same mean value for the clinical and 3d methods as seen in table (4). table 1: descriptive statistics and gender difference for the variables measured in 3d image measurements descriptive statistics gender difference (d.f.=37) total sample (n=39) males (n=18) females (n=21) mean s.d. mean s.d. mean s.d. mean difference t-test p-value ramus to 7 (ab) 10.25 0.73 10.34 0.79 10.18 0.68 0.16 0.67 0.507 (ns) md of 8 (cd) 9.42 0.24 9.52 0.24 9.34 0.22 0.18 2.54 0.015 (s) ratio of ab/cd 1.08 0.08 1.08 0.09 1.09 0.07 0.01 0.20 0.844 (ns) table 2: descriptive statistics and gender difference for the variables measured in 2d image measurements descriptive statistics gender difference (d.f.=37) total sample (n=39) males (n=18) females (n=21) mean s.d. mean s.d. mean s.d. mean difference t-test p-value ramus to 7 (ab) 9.13 0.72 9.24 0.79 9.03 0.66 0.21 0.91 0.369 (ns) md of 8 (cd) 8.63 0.25 8.72 0.26 8.54 0.23 0.18 2.32 0.026 (s) ratio of ab/cd 1.05 0.08 1.06 0.10 1.05 0.08 0.01 0.12 0.907 (ns) j bagh college dentistry vol. 28(4), december 2016 evaluation of mandibular pedodontics, orthodontics and preventive dentistry 170 table 3: descriptive statistics and image difference for the variables measured measurements descriptive statistics image comparison (d.f.=38) 3d image 2d image mean s.d. mean s.d. mean difference t-test p-value ramus to 7 (ab) 10.25 0.73 9.13 0.72 1.13 49.21 0.000 (hs) md of 8 (cd) 9.42 0.24 8.63 0.25 0.80 116.24 0.000 (hs) ratio of ab/cd 1.08 0.08 1.05 0.08 0.03 10.65 0.000 (hs) table 4: descriptive statistics and measurements difference for the md width of permanent mandibular first molars md of 6 measurement descriptive statistics measurements difference (d.f.=38) mean s.d. mean difference t-test p-value 3d image 10.28 0.31 0.80 125.73 0.000 (hs) 2d image 9.48 0.30 clinical 10.28 0.32 -0.001 -0.007 0.994 (ns) 3d image 10.28 0.31 clinical 10.28 0.32 0.799 11.531 0.000 (hs) 2d 9.48 0.30 discussion it is important to mention that direct comparisons with results from other studies will not be always possible, since this study represents the first approach to compare the 3d ct and the 2d reconstructed lateral view in the assessment of mandibular third molar position. the age of samples ranged between 11-15 years old because development of mandibular third molar was not completed at this age, early removal of third molar at this age is simple and atraumatic (9). about the distance from anterior border of ramus to distal surface of permanent mandibular second molar (ab), the result of the study showed that there was gender difference in the mean value of this measurement, with the mean value of this measurement in males higher than females, this comes in agreement with finding of other researches (10-12). about the mesio-distal width of developing mandibular third molar (cd), the result of the present study agreed with the finding of abu alhaija et al. (11). there was significant difference between males and females, this can be explained by the fact that the teeth dimensions in males are larger than females and this comes in accordance with the finding of bindayel (2). furthermore, the ratio of ab/cd in the present study was agreed with the finding of zelic and nedeljkovic (13) who found no significant gender difference. this finding can be related to the age of the group in the sample and this ratio may be increase with age of patients due to remodeling and growth. regarding the mean value of the ratio, it is more than 1 and this indicated the presence of adequate space for the eruption of the lower third molar. in this study, all the measurements on 3d and on 2d images showed statistically high significant difference. this may be explained by that the two dimensional diagnostic imaging including the reconstructed lateral view have certain analysis limitations such as geometric distortion, superimposition of structures, rotational errors and linear projective transformation. to compare between the clinical and image method of measurement, the mean value of the width of mandibular 1st molar measured clinically and by 3d image is coincide, while it is about 0.8 mm smaller than 2d image. this result gives an impression about the accuracy of 3d image in measurement and diagnosis of orthodontic problems. although the method difference is statistically significant but clinically is of no value (0.3). references 1. "wisdom teeth". american association of oral and maxillofacial surgeons. retrieved 2010-09-28. 2. bindayel a. the role of third molar in orthodontic treatment. pakistan oral dental j 2011; 31(2): 374-7. 3. menzies ca. radiographic survey of third molar development: a comparison. br j orthod 1984; 11: 109-15. 4. judd w. consensus development conference at the national institutes of health. indian health services http://www.aaoms.org/wisdom_teeth.php j bagh college dentistry vol. 28(4), december 2016 evaluation of mandibular pedodontics, orthodontics and preventive dentistry 171 dental newsletter 1980; 18:63-80. (cited by bishara s, andereason g. third molars, a review. am j ortho dentofac orthop 1983; 83: 131-7) 5. laskin dm. evaluation of third molar problem. jada 1971; 82: 824-8. 6. quiros j, palma a. the mandibular third molar: a method for predicting its eruption. ortho j 1999; 2(4): 8-15. 7. foster td. a textbook of orthodontics. 3rd ed. oxford; london: blackwell scientific publications; 1990. p. 83-5. 8. olive r, basford k. reliability and validity of lower third molar space assessment technique. am j orthod 1981; 79: 45-52. 9. ricketts rm. third molar inoculation: diagnosis and technique. j calif dent assoc 1976; 4: 52-7. 10. hattab fn, alhaija es. radiographic evaluation of mandibular third molar eruption space. oral surg oral med oral pathol oral radiol endod 1999; 88: 285-91. 11. abu alhaija es, al-bhairan hm, al-khateeb sn. mandibular third molar space in different anteroposterior skeletal patterns. eur j orthod 2011; 33: 570–6. 12. qamruddin i, qayyum w, mahmood s, wasif s, rehan f. differences in various measurements on panoramic radiograph among erupted and impacted lower third molar groups. j pak med assoc 2012; 62(9): 883-7. 13. zelic k, nedeljkovic n. size of the lower third molar space in relation to age in serbian population. vojnosanit pregl 2013; 70(10): 923–8. rola f.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the effect of thermocycling 12 the effect of thermocycling and different ph of artificial saliva on the impact and transverse strength of heat cure resin reinforced with silanated zro2 nano-fillers. rola w. abdul-razaq, b.d.s., m.sc. (1) abstract background: the aim of this study was to evaluate the effect of thermo cycling and different ph of artificial saliva (neutral, acidic, basic) on impact and transverse strength of heat cure acrylic resin reinforced of with 5% silanated zro2 nano fillers. materials and methods: 120 samples were prepared, 60 samples for impact strength test and another 60 samples for transverse strength test, for each test, samples were divided into two major groups (before and after thermo cycling), then each of these major groups were further subdivided into 3 subgroups according to the ph of prepared artificial saliva (neutral, acidic, basic). charpy impact device was used for impact strength test and flexural device was used for transverse strength test. result: there was a non-significant difference between the two major groups (before and after thermo cycling). also results showed that there was a non-significant difference between the subgroups for each major group in reference to ph of artificial saliva. these results were found in both impact and transverse strength. conclusion transverse strength and impact strength of heat cure acrylic resin reinforced with silanated zro2 nanofillers was not affected by thermocycling and different ph of artificial saliva suggesting improvement in the mechanical properties. key word: artificial saliva, thermo cycling, impact strength, transverse strength, nanocomposite. (j bagh coll dentistry 2013; 25(special issue 1):12-17). introduction saliva in the mouth participates in the activity of speaking, swallowing, chewing, mucosal protection against penetration of various substances, regulation of ph, taste sensitivity and lubrication of tissue.(1) due to the impossibility of duplicating the properties of human saliva as a result of the inconsistent and unstable nature of natural saliva, a development of artificial saliva is essential for well justified and controlled experiments which were reported as early as since 1931.(2) during use, prostheses are submitted to various clinical situations like different temperature, alteration in ph, salivary flow, and the denture base material should withstand all these condition without change. acrylic resin was the material which were used in complete dentures, so this material has been subjected to different alterations including several types of reinforcement to improve their properties.(3) because denture base materials had a high incidence of fractures and need to a constant repairs. different methods are used to reinforce these materials. (4) so an improvement in properties of polymers can be achieved with the addition of nano-sized fillers. the purpose of using nano fillers is to achieve higher abrasion resistance, improved esthetic, physical and mechanical properties of dental materials. (1)assistant lecturer. department of prosthodontics. college of dentistry. university of baghdad. increase several properties of the material like mechanical strength can be obtained by blending polymer material with different organic fillers (5). the size, shape, concentration, type of nanoparticals, and interaction with polymer matrix affect the properties of polymer nano composites. (6) the ability of a denture base material to be strong to withstand functional and masticotary forces can be reflected by the flexural and impact strength of the material.(7) in denture wearing patients saliva has an important role in providing comfort to the mucosa under denture base, maintenance of oral health and denture retention.(8) the normal range of salivary ph is between 6.2-7.4, so any change in the ph of saliva would be due to different types of food ingested. so it may be more acidic or more basic which may have an erosion effect on denture base materials. (9) during service in oral cavity denture resins subjected to a variation in temperatures by ingestion of cold and hot foods which causes a thermal stresses in denture base materials, this thermal stress will have an effect on the water sorption of denture base materials because water sorption is a process that depended on temperature. (10) although reports on the effect of thermo cycling on impact and transverse strength are limited but it is important to be investigate. (10) the aim of this in vitro study was to evaluate the effect of different ph of artificial saliva and restorative dentistry 13 thermo cycling on impact and transverse strength of heat cure acrylic resin reinforced with 5% of silanated zro2nano fillers. materials and method 120 samples were prepared for this study, these samples were divided into 60 samples for impact strength test and 60 samples for transverse strength test. for each test the samples were divided into two major groups: before thermo cycling contains 30 samples and after thermo cycling which also contain 30 samples. each major group were subdivided into three subgroups contains 10 samples for each and stored in artificial saliva with different ph (neutral, acidic and basic). the materials used in this study was: heat cured acrylic denture resin (superacryle plus,spofa dental; europe), dental stone (type iii, zermack; italy), distilled water (iraq) , separating medium (iso dent,spofa dental; europe), silanated zirconium oxid (zro2) nano fillers (sigma, aldrich; germany). artificial saliva preparation artificial saliva was prepared in different ph (acidic: 5.7-nuetral: 7-basic: 8.3) by using ph meter device (wtw, germany). preparation of saliva had been done by using an electrolytes composition similar to that of human saliva according to (pusz et al, 2010) and as illustrated in table 1. table 1: the chemical constituents of the artificial saliva used in the study material conc. material conc. nacl 0.700 g/l na2hpo4 0.260 g/l kscn 0.330 g/l kcl 1.200 g/l kh2po4 0.200 g/l nahco3 1.500 g/l buffer solution from kh2po4 and na2hpo4 was prepared by dissolving each one in 1 liter of de-ionized distilled water. (12) then basic saliva was prepared by taking 500 ml of na2hpo4 and added kh2po4 gradually to it until reached the exact ph, after that added the other salts to saliva and complete the volume to 1 liter by de-ionized distilled water. (12) on the other hand, neutral and acid saliva were prepared by taking 500 ml of kh2po4 and added na2hpo4 gradually to it until reached the exact ph. then adding the other salts just like in basic saliva. for neutral saliva greater amount of na2hpo4 was added to reach the exact ph, to control the measurement, a freshly artificial saliva was prepared every day because the ph of saliva may change within 48h. (12) impact strength test a mould of stone in dental flask was prepared by using bar shaped metal pattern with dimensions of (80mm, 10mm and 4mm) length, width and thickness respectively figure (1). after that the mould was coated by separating medium and left to dry for 15 minutes, then packing with acrylic resin. preparation of acrylic was done by the following: the p/l ratio for acrylic was 2.5g:1g according to the manufacturer's instructions, the amount of acrylic powder was (11.400 g) weighted by using electronic balance (sartorius bp 30155, germany) of ( 0.0001g) accuracy, the amount of monomer was (6ml=4.80g) to which the 5% silanated (0.600g)of zro2 nano fillers was added. the zro2 filler was mixed with the monomer by ultra sonication for 3 minutes using a probe sonication apparatus (saniprep-150, england, 120w,60khz), the silanated nanofiller were well dispersed into the monomer(13), then the acrylic was mixed and packed in the dough stage in the mould and cured. the curing process was done according to ada specification no 12, 1999 by heating the dental flask in water bath at 74cº for 1.5 hours, then increased the temperature to boiling for 30 minutes, after that cool the flask for 30 minutes at room temperature, then for 15 minutes under tap water. after flask was cold, the acrylic samples were removed, finished and polished. half of samples (30) were stored in artificial saliva (neutral, acidic and basic) for 16 hours and then in distilled water for 8 hours at 37cº in an incubator for 30 days. (12, 14) the other half of samples (30) were subjected to thermo cycling by (1000 cycle) then stored in artificial saliva (neutral, acidic and basic) for 30 days like above. the thermo cycling was done by using machine (haack, germany) that subject the samples in bath of hot distilled water (55cº±2cº) for 30 seconds then in other bath of cold distilled water (5cº±2cº) for 30 seconds, this cycle was repeated until complete 1000 cycles.(12) the samples were tested with charpy type impact testing device (impact tester, n. 43-1, inc. usa) of 2 joules capacity, impact strength was calculated by this formula: impact strength = in kj/m² by anusavice (15) where: e= impact energy, b= width of sample, d= thickness of sample. transverse strength test the procedure for preparation of the transverse strength samples were done just like the procedure for preparation of impact strength samples, the dimensions of transverse test restorative dentistry 14 samples were (65mm, 10mm and 2.5mm) length, width and thickness, respectively figure (1). the samples were tested by flexural measuring device (jian, qiao, japan). the full scale load was (7.5 kn), the distance between 2 parallel supports was (50mm) and transverse strength was calculated by this formula: transverse strength= in n/mm2 (anusavice, 2008). (15) where: p= peak load, i= distance between 2 support, b= width of sample, d= thickness of sample. the samples shown in figure 1, 2 for impact and transverse strength test before and after testing. (a) (b) figure 1: asamples for impact strength before testing. bsamples for transverse strength before testing. figure 2: samples for transverse and impact strength after testing. results impact strength test: (before thermo cycling) table (2) and figure (3) shows the mean distributions, standard deviation, maximum value and minimum value for samples before thermo cycling in neutral, acidic and basic artificial saliva, the maximum mean value was found in basic saliva (8.92 kj/m²) and the minimum mean value was found in acidic saliva (8.02 kj/m²). table 2: mean, sd, max and min for impact strength in kj/m² for samples before thermo cycling. figure 3: bar chart for impact strength means in kj/m² for samples before thermo cycling. in table (3) one way anova analysis of variance shows a non-significant difference between the three groups at different ph of artificial saliva, the p-value was (0.814). table 3: anova (f-test) analysis between neutral, acidic and basic saliva for samples before thermo cycling. anova f-test p-value sig 0.207 0.814 ns impact strength test: (after thermo cycling). table (4) and figure (4) show the mean distribution, standard deviation, maximum value and minimum value for samples after thermo cycling in neutral, acidic and basic saliva. the maximum mean value was found in basic saliva (8.97 kj/m²) also the minimum mean value was found in basic saliva (8.12 kj/m²). table 4: means, sd, max and min for impact strength in kj/m² for samples after thermo cycling. sample groups neutral acid base mean 8.553 8.545 8.612 sd 0.229495 0.280802 0.24939 max 8.9 8.9 8.92 min 8.25 8.02 8.26 sample groups neutral acid base mean 8.550 8.599 8.583 sd 0.206667 0.170258 0.284138 max 8.82 8.85 8.97 min 8.25 8.38 8.12 restorative dentistry 15 figure 4: bar chart for impact strength means in kj/m² for samples after thermo cycling. in table (5) one way anova analysis of variance shows non-significant differences between the three groups of different ph of saliva, the p-value was (0.885). table 5: anova (f-test) analysis between neutral, acidic and basic saliva for samples after thermo cycling in table (6) and figure (5) t-test between samples before and after thermo cycling shows a non-significant difference for the three groups of different ph of saliva. p-value for neutral groups was (0.972), for an acidic group was (0.635) and for basic groups was (0.814). table 6: t-test between samples before and after thermo cycling for impact strength test figure 5: bar chart for comparison between means in kj/m² for impact strength samples before and after thermo cycling. transverse strength test (before thermo cycling) table (7) and figure (6) shows the mean distribution, standard deviation, maximum value and minimum value for samples before thermo cycling in neutral, acidic and basic artificial saliva, the maximum mean value was found in basic saliva (588.1 n/mm2) and the minimum mean value was found in acidic saliva (511.8 n/mm2). table 7: mean, sd, max and min for transverse strength in n/mm2 for samples before thermo cycling figure 6: bar chart for transverse strength means in n/mm2 for samples before thermo cycling. in table (8) one way anova analysis of variance shows a non-significant difference between the three groups at different ph of saliva, the p-value was (0.984). table 8: anova (f-test) analysis between neutral, acidic and basic saliva for samples before thermo cycling transverse strength test (after thermo cycling) table (9) and figure (7) shows the mean distribution, standard deviation, maximum value and minimum value for samples after thermo cycling in neutral, acidic and basic artificial saliva, the maximum mean value was found in basic saliva (588.2 n/mm2) and the minimum mean value was found in neutral saliva (525.2 n/mm2). anova f-test p-value sig 0.123 0.885 ns groups t-test p-value sig neutral 0.036 0.972 ns acid 0.491 0.635 ns base 0.242 0.814 ns sample groups neutral acid base mean 556.03 556.18 554.56 sd 19.90612 26.205 20.3732 max 582.1 583.1 588.1 min 521.8 511.8 527.2 anova f-test p-value sig 0.016 0.984 ns restorative dentistry 16 table 9: means, sd, max and min for transverse strength in n/mm2 for samples after thermo cycling figure 7: bar chart for transverse strength means in n/mm2 for samples after thermo cycling. in table (10) one way anova analysis of variance shows a non-significant difference between the three groups of different ph of saliva, the p-value was (0.921). table 10: anova (f-test) analysis between neutral, acidic and basic saliva for samples after thermo cycling in table (11) and figure (8), t-test between samples before and after thermo cycling shows a non-significant differences for the three groups of different ph of saliva, the p-value for the neutral groups was (0.992), for acidic groups was (0.739) and for basic groups was (0.705). table 11: t-test between samples before and after thermo cycling for transverse strength test figure 8: bar chart for comparison between means in n/mm2 for transverse strength samples before and after thermo cycling. discussion in this study addition of 5% silanated zro2 nano-fillers to the heat cure acrylic resin were done in order to prepare reinforced acrylic material, it was found that there is no effect of thermo cycling process and different ph of artificial saliva on both impact and transverse strength. this can be explained by that silane coupling agent has an affinity to the polymer matrix because silane contain vinyl group and alkoxy groups that can react with organic matrix and substrate. so this will form covalent bonds between both matrices. so the use of silane coupling agent was to coat the fillers and this will led to produced covalent bonded polymer chain because coated fillers has an affinity to polymer matrix.(16) this bond can prevent water from penetrating filler resin interface by inhibition of fluid leaching and improved the adhesion between polymer matrix and enforcing filler, so this will improve the mechanical properties of the acrylic resin materials. (15,17) also due to the use of very fine size nanofillers with concentration between (5 %) enable them to enter and fill the space between the chains of polymer, so it restrict the motion of chains and lead to increase rigidity and this will increase the transverse strength. (18) the addition of 5% of silanated zro2nanofillers to the acrylic resin showed a higher impact and transverse strength by (safi i.n, 2011). which made the acrylic material more strong by the addition of zirconium.(19) water sorption could decrease the strength of the polymer because water molecules acts as a plasticizer and weak acids that causes mobility of polymer chains. (20, 21) so the use of silanated fillers made the mixture more homogenous and decreases the mobility of polymer chains and this make pmma stronger sample groups neutral acid base mean 555.95 559.42 557.85 sd 19.59077 18.66648 19.12551 max 583.3 585.7 588.2 min 525.2 528.6 526.3 anova f-test p-value sig 0.082 0.921 ns groups t-test p-value sig neutral 0.011 0.992 ns acid 0.344 0.739 ns base 0.390 0.705 ns restorative dentistry 17 and leads to increase the transverse and impact strength. (3, 22, 23) on the other hand, the highly filled material by silanated molecules forms a layer to protect the surface of filler particles from the erosional effect of acids and bases. so the storage in the acidic and basic environments had no significant effects on the transverse and impact properties of the reinforced resin bases. (21) as conclusion, the addition of 5% of silanated zro2 nanofillers makes the acrylic resistant to the effect of change in the ph of artificial saliva and the thermocycling process as shown by the non-significant effect on both transverse and impact strength. references 1. silva mp, junior jc, jorjaa al, machado aks, olivera ld, junqueira jc, jorge aoc. influence of artificial saliva in biofilm formation of candida albicans in vitro. braz oral res 2012; 26(1): 24-8. 2. leung vwh, darvell bw. artificial saliva for in vitro studies of dental materials. j dent 1997; 25: 475-85. 3. silva lh, feitosa sa,valeva mc, aranjo mam, tanjo rn. effect of addition of silanated silica on the mechanical properties of microwave heat-cured acrylic resin. gerodontology j 2012; 29: 1019-23 (ivsl). 4. oris la, soares rg, villabona ca, panzeri h. evaluation of the flexural strength and elastic modulus of resins used for temporary restorations reinforced with particulate glass fiber. gerodontology j 2012; 29: 63-8 (ivsl). 5. fischer h. polymer nanocomposite: from fundamental research to specific applications. materials science and engineering: c. 2003; 23: 763-72. 6. jordan j, jacob kl, tannenbaum r, shart ma, jasink i. experimental trends in polymer nanocompositesa review. mater sci eng 2005; 393(1): 1-11. 7. seo rs, murata h, hong g. influence of thermal and mechanical stress on strength of intact and reline denture bases. j prosthet dent 2006; 96: 59-67. 8. lakhyani r, wagdargi ss. saliva and its importance in complete denture prosthodontics. njirm 2012; 3(1): 139-146. 9. minich dm, bland js. acid –alkaline balance: role in chronic disease and detoxification. alternative therapies in health and medicine 2007; 13: 62-65. 10. machado al, puckett ad, breeding lc, wady af, vergani ce. effect of thermocycling on flexural and impact strength of urethane-based and high-impact denture base resins. gerodontology j 2012; 29: 318-23 (ivsl). 11. pusz a, szymicze km, michalik k. aging process influence on mechanical properties of polyamide-glass composites applied dentistry. j achiv mat 2010; 38(1): 49-55. 12. hussein ya. the influence of different ph of saliva and thermal cycling on adaptation of different denture base materials. a master thesis, department of prosthetic dentistry, college of dentistry, university of baghdad, 2012. 13. safi in. evaluation of the effect of modified nanofillers addition on some properties of heat cure acrylic resin denture base material. a master thesis, department of prosthetic dentistry, college of dentistry, university of baghdad, 2011. 14. qasim sb, alkheraif aa, ramakrishaniah r. an investigation into the impact and flexural strength of light cure denture resin reinforced with carbon nanotubes. world app sci 2012; 18(6): 808-12. 15. anusavice kj. philips science of dental materials. 11th ed. st. louis: saunders elsevier; 2007. p.143-166, 721-756. 16. benjamin jash, rogers df, wicgand cj, schadler ls, siegel rw, benicewicz bc, apple t. mechanical properties of al2o3 / polymethyl methacrylate nanocomposites. polymer composites 2002; 23(6): 1014-25. 17. kani t, fujii k, arikawa h. inoue k. flexural properties and impact strength of denture base polymer reinforced with woven glass fibers. dent mat 2000; 16:150-8. 18. katsikis n, franz z, anne h, helmut m, andri v. thermal stability of pmma/ silica nano-and micro composites as investigated by dynamic-mechanical experiments. polymer degra and stability 2007; 22: 1966-76. 19. ayad nm, badawi mf, fatah aa. effect of reinforcement of high impact acrylic resin with microzirconia on some physical and mechanical properties. cairo dent j 2008; 24(2): 245-50. 20. takahashi y, yoshida k, shimizu h. fracture resistance of maxillary complete dentures subjected to long-term water immersion. gerodontology j 2012; 29: 1086-91(ivsl). 21. ferracane jl. hygroscopic and hydrolytic effect in dental polymer networks. dent mater 2006; 22: 21122. 22. bowen rl. compatibility of various materials with oral tissue. j dent res 1979; 58: 1493-1501. 23. hu y, zhou s, wu l. surface mechanical properties of transparent pmma/ zirconia nano-composites prepared in situ bulk polymerization. polymer 2009; 50: 3609-3616. thaer.doc j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 128 immunohistochemical expression of mmp9, as a marker of local invasion in hodgkin’s and non-hodgkin’s lymphoma of the head and neck region thaer k. ali, b.d.s., m.sc. (1) bashar h. abdulla, b.d.s., m.sc., ph.d. (2) khitam r. kadhim, m.b.ch.b., f.i.c.m.s. (3) abstarct background: malignant lymphoma is the generic term given to tumors of the lymphoid system and specifically of lymphocytes and their precursor cells, while all lymphomas are malignant neoplasms, there is a wide spectrum of clinical behavior, with some following an indolent clinical course and others behaving in an aggressive manner (will causing death in a short time frame if left untreated). the metastatic process involves intravasation and extravasation of tumor cells, followed by reimplantation of tumor cells, formation of a new tumor stoma, degradation of the extracellular matrix and components of the basement membrane by proteases facilitates the detachment of tumor cells, their crossing of tissue boundaries, and invasion into adjacent tissue compartments. the importance of tumor-associated proteases in invasion and metastasis has been demonstrated for a variety of solid malignant tumors. mmp family has been implicated in tumor cell invasion and metastasis. material and methods: this study included 67 formalin-fixed, paraffin-embedded histopathologically diagnosed lymphoma blocks (head and neck lesions), 24 hodgkin’s lymphoma and 43 non hodgkin’s lymphoma. immunohistochemical (ihc) evaluation of mmp-9 monoclonal antibodies), in relation to the clinicopathological parameters was assessed. results: the mean of expression of mmp-9 in nhl was higher (65.4±18) than that in hl (56.7±21.4) though it did not reach the level of statistical difference p > (0.05), while the mean of expression of mmp-9 in relation to tumor grades was different as it had a value of (72±14.1) in low grade tumors, (68.3±15) in the intermediate grade tumor and (61.4±20.7) in high grade tumors; consequently, this difference did not reached the level of statistical significance p(anova) >0.05 . mmp 9 had no statistical significant correlation in regard to its mean in hl subtypes. conclusions: this study had shown that there was no significant correlation between age and mean of expression of mmp-9 in hl and nhl. there was no statistical significant difference in the mean of expression of mmp-9 between hl and nhl subtypes. keywords: mmp-9, local invasion, hodgkin’s lymphoma, non hodgkin’s lymphoma. (j bagh coll dentistry 2015; 27(1):128-132). introduction malignant lymphomas can be divided into two major categories: hl and nhl. lymphomas presenting in extranodal sites of the head and neck and these sites includes oral cavity, oropharynx, nasopharynx, paranasal sinuses, and larynx which are mainly nhls of low or high grade, it may also present as cervical lymphadenopathy which is the most common head and neck presentation for both diseases (1,2). the metastatic process involves intravasation and extravasation of tumor cells, followed by reimplantation of tumor cells, formation of a new tumor stoma, and neoangiogenesis to consolidate a secondary tumor at a distant site (3). degradation of the extracellular matrix and components of the basement membrane by proteases facilitates the detachment of tumor cells, their crossing of tissue boundaries, and invasion into adjacent tissue compartments. (1) m.sc department of oral and maxillofacial pathology, college of dentistry, university of baghdad. (2) professor. head department of oral and maxillofacial pathology, college of dentistry, university of baghdad. (3) assistant professor. head department of pathology& forensic medicine, college of medicine university of baghdad. the importance of tumor-associated proteases in invasion and metastasis has been demonstrated for a variety of solid malignant tumors. mmp family has been implicated in tumor cell invasion and metastasis. as tumors vary considerably in their behavior; the degree of their differentiation and ability to invade and metastasize are not the same, however, not all cancers have equivalent ability to metastasize. in general the more likely anaplastic and larger is the primary neoplasm, the more likely is the metastatic spread, however, exceptions abound, i.e. extremely small cancers have been known to metastasize and conversely some large ugly lesions may not spread (4,5). because of the obscure and variable biological behavior of head and neck hodgkin lymphoma this study will concerned with tumor dynamics such as mmp9 as a biological marker in hl and nhl of the head and neck. the aim of this study is to evaluate the expression of the biological marker of local invasion (mmp-9) in hodgkin’s and nonhodgkin’s lymphoma via immunohistochemical technique. j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 129 materials and methods this study included (67) formalin-fixed, paraffin-embedded histopathologically diagnosed lymphoma blocks (head and neck lesions). the diagnosis of each case was confirmed by the histological examination of the hematoxylin and eosin staining (h&e), examined by two experienced pathologists. demographic and clinical data provided by the surgeon were obtained from the case sheets presented with the tumor specimens, including information concerning patient's age, gender, clinical presentation, site of tumor. histological classification was determined according to the international working formula (iwf) criteria, where the lesions classified into hodgkin's lymphoma (24cases) and non-hodgkin's lymphoma (43 cases). positive tissue controls included in this study were breast carcinoma for mmp-9. the diagnosis of each case was confirmed by the use of cd15, cd30 for hl and cd20, bcl2 for nhl. sections of 5µm thickness were mounted on glass slides for routine (h&e), from each block of the studied sample and the control group for histopathological re-examination. other sections of 4µm thickness were mounted on positively charged microscopic slides (biocare medical and fischre brand) to obtain a greater tissue adherence. all of these collected specimens were subjected to immunohistochemical staining using specific monoclonal antibodies included in the study mmp9. abcam, expose mouse and rabbit specific hrp/dap detection ihc kit, antigen retrieval solutions: citrate buffer ph 6.0., mouse monoclonal [ab58803] to mmp9 abcam, england. immunohistochemical staining is accomplished with antibodies that recognize the target protein. only the number of cells showing cytoplasm and the cell membrane expression of mmp9 was quantified by counting at least 1000 cells in five representative fields at 40x objective in each case, the intensity of staining was not considered for evaluation. tumor cells with brown staining of the cell membrane predominately or of the cytoplasm and the cell membrane occasionally were considered positive for mmp-9 the percentage of mmp-9 positively stained cells was semi-quantitatively determined as follows (-) negative ≤5%, (+) low 6-25%, (++) moderate 26-50% and (+++) high 51-100%. statistical analysis an expert statistical advice was sought for. statistical analyses were done using spss version 21 computer software (statistical package for social sciences) in association with microsoft excel 2010. results the mean of expression of mmp 9 in nhl was higher (65.4±18) (fig 1, 2 and 3) than that in hl (56.7±21.4) (fig 4 and 5) though it did not reach the level of statistical significant difference p >0.05, this result is shown in table 1 regarding nhl the mean of expression of mmp 9 in low grade was 72±14.1 and in intermediate grade the mean was 68.3±15 while in high grade it had a mean of 61.4±20.7 and even when the mean of mmp -9 was different between the grades of nhl but it did not reach the level of statistical significance. these details are found in table 2. in hl cases the mean of expression of mmp 9 in mixed cellularity (65.9±19.4) was higher than that of nodular sclerosing (53.3±22.2). obviously there was a difference in the mean of expression but it did not reveal any statistical significance. table 3 gives the difference in mean of expression of mmp 9 between nodular sclerosing and mixed cellularity. table 1: difference in mean of expression of mmp 9 between hl and nhl mmp9 nhl compared to hl p (t-test) hl nhl range (17 93) (23 97) 0.08 [ns] mean 56.7 65.4 sd 21.4 18 se 4.36 2.75 n 24 43 j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 130 table 2: difference in mean of expression of mmp 9 between tumor grades of nhl mmp9 tumor grade p (anova) trend low grade intermediate grade high grade range (49 92) (38 97) (23 97) 0.21 [ns] mean 72 68.3 61.4 sd 14.1 15 20.7 se 5.77 3.75 4.52 n 6 16 21 table 3: difference in mean of expression of mmp 9 between nodular sclerosing and mixed cellularity mmp9 morphology p nodular sclerosing mixed cellularity range (17 93) (37 87) 0.21 [ns] mean 53.3 65.9 sd 22.2 19.4 se 5.55 7.33 n 16 7 fig 3: nhl small cell type mmp9 cytoplasmic expression (x400) fig 4: hl mixed cellularity mmp9 expression in hodgkin’s cells. (x1000) fig 1: nhl dlbc mmp9 cytoplasmic expression (x400) fig 2: burkitt’s lymphoma mmp9 expression (x400) j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 131 discussion matrix metalloproteinase (mmp)-mediated degradation of the extracellular matrix is a key point in tumor development and expansion. a former study found elevated expression of mmp9 and mmp10 in endometrial tumor related endothelium. xue-lian du et al (6) stated that the metastatic process involves intravasation and extravasation of tumor cells, followed by reimplantation of tumor cells, formation of a new tumor stroma, and neoangiogenesis to consolidate a secondary tumor at a distant site. degradation of the extracellular matrix and components of the basement membrane by proteases facilitates the detachment of tumor cells, their crossing of tissue boundaries, and invasion into adjacent tissue compartments. in recent years, the importance of tumorassociated proteases in invasion and metastasis has been demonstrated for a variety of solid malignant tumor. one of the first observations that suggested a role for mmp-9 in tumor invasion relates to the fact that the release of mmp-9 is associated with the metastatic phenotype of transformed rat embryo cell 92,000 gelatinase release correlates with the metastatic phenotype in transformed rat embryo cells (7,8). the increase in pro-mmp-9 in ovarian cancer and their corresponding metastases could be attributable to the infiltration of inflammatory cells that express a high amount of pro-mmp-9 and often surround malignant tumors that growth of liver metastasis from colon cancer was associated with elevated tumor tissues mmp-9, and treatment of ulinastatin significantly reduces mmp-9 expression (9,10). mmp-9 may be particularly relevant to the progression of lymphomas. mmp-9 has been shown to be important for the in vitro degradation of extracellular matrix components by nonhodgkin's lymphoma cells (11). in vivo, mmp-9 is also overexpressed in a subset of high grade nonhodgkin's lymphomas, and this correlates with a poor clinical outcome. the results of this study showed that mmp-9 is consistently expressed by the malignant hodgkin and reed-sternberg cells of hodgkin's disease (12). this study had showed that the expression of mmp 9 in hl56.7±21.4mean of expression and in nhl the mean was 65.4±18 with positive staining in all cases and this is in accordance with previous studies in regard to its expression in all malignant tumors moreover its expression was higher in nhl cases than hl cases but it did not reached the level of statistical significance. the infiltration of inflammatory cells that express a high amount of pro-mmp-9 and often surround malignant tumors (10). mmp-9 may be particularly relevant to the progression of lymphomas which has been shown to be important for the in vitro degradation of extracellular matrix components by nonhodgkin's lymphoma cells; mmp-9 is also overexpressed in a subset of high grade nonhodgkin's lymphomas, and this correlates with a poor clinical outcome. the results of previous study showed that mmp-9 is consistently expressed by the malignant hodgkin and reedsternberg cells of hodgkin's disease12. regarding the grades of the tumors, mmp9 showed negative non-significant correlation with the tumor grades and this in agreement with other studies (13,14) whom concluded from their study that there is no correlation was found between mmp-9 expression and tumor invasion or histological grade; whereas other studies had reached to contradictory results as the levels of mmp 9 and mmp 2 are highly correlated with the histological grade of malignancy (15, 16). moreover other study reached to a conclusion that mmp-9 has been showed a tendency to increase with increasing tumor grade (15, 17). the possible explanation for this difference in relation of mmp 9with tumor grade might be attributed to fig 5: hl mixed cellularity mmp9 expression in hodgkin’s cells. (x400) j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 132 microenvironment component interaction and to small sample size of this study as compared with large studies. references 1. rosai j. ackerman's surgical pathology. 10th ed. elsevier, mosby; 2011. 2. rubin r, strayer ds. rubin's pathology. 6th ed. philadelphia: lippincott williams & wilkins; 2012. 3. hanahan d, weinberg ra. the hallmarks of cancer. cell 2000; 100: 57-70. 4. kumar a, boriek am. mechanical stress activates the nuclear factor-kappab pathway in skeletal muscle fibers: a possible role in duchenne muscular dystrophy. faseb j 2003; 17: 386–96. 5. arshak ss. review. in: (eds.) immuonohistochemical expression of epidermal growth factor receptor (egfr) in oral squamous cell carcinoma in relation to proliferation, apoptosis, angiogenesis and lymphangiogenesis. 1st ed. iraq; 2008. 6. xue-lian du. gene alterations in tumor-associated endothelial cells from endometrial cancer. international j molecular medicine 2008; 22: 619-32. 7. barbara s. increased expression of matrix metalloproteinases (mmp)-2, mmp-9, and the urokinase-type plasminogen activator is associated with progression from benign to advanced ovarian cancer. clin cancer res 2001; 7: 2396 8. bernhard ej, muschel rj, hughes en mr. the invasiveness of ovarian cancer cell lines correlated with expression of mmp-2 and mmp-9 in vitro cancer res 1990; 50: 3872-7. 9. zeng zs, guillem jg. distinct pattern of matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 mrna expression in human colorectal cancer and liver metastases. br j cancer 1995; 72: 575-82. 10. mccawley lj, matrisian lm. tumor progression: defining the soil round the tumor seed. curr biol, 2001; 11: r25-r27 11. xu b, li k, shen f, xiao h, cai w, li j, liu q, jia l. ulinastatin reduces cancer recurrence after resection of hepatic metastases from colon cancer by inhibiting mmp-9 activation via the antifibrinolytic pathway. biomed research international 2013; 2013: 437950.. 12. flavell jr, baumforth krn, williams dm, lukesova m, madarova j, noskova v, prochazkova j, lowe d, kolar z, murray pg, nelson pn. expression of the matrix metalloproteinase 9 in hodgkin's disease is independent of ebv status. molecular pathology 2000; 53(3):145-9. 13. panagopoulos at, lancellotti cl, veiga jc, de aguiar ph, et al. expression of cell adhesion proteins and proteins related to angiogenesis and fatty acid metabolism in benign, atypical, and anaplastic meningiomas. j neurooncol 2008; 89: 73-87. 14. quan huang, 5185 increased co-expression of macrophage migration inhibitory factor and matrix metalloproteinase 9 is associated with tumor recurrence of meningioma. int j med sci 2013; 10(3): 276-85. 15. rao js, steck pa, mohanam s., stetler-stevenson w. g., liotta l. a., sawaya r. elevated levels of mr 92,000 type iv collagenase in human brain tumors. cancer res 1993; 53: 2208-211. 16. gheeyoung choe, active matrix metalloproteinase 9 expression is associated with primary glioblastoma subtype. clin cancer res september 2002; 8: 2894. 17. paek sh, kim cy, kim yy, et al. correlation of clinical and biological parameters with peritumoral edema in meningioma. j neurooncol 2002; 60: 23545. الخالصھ ینما كل اللمفوما ھي اورام خبیثھ وھناك اللمفوما الخبیثھ ھو مصطلح عام یعطى الى االورام التي تصیب الجھاز اللمفاوي وبصورة خاصھ الخالیا اللمفاویھ والخالیا المكونھ لھل ب: خلفیھ عملیة االنتشار تتضمن الدخول . الجطیف واسع من التصرف العیادي حیث بعضھا یتبع نمطا عیادیا بطیأ واالخر یتصرف بطریقھ عدوانیھ مسببا الموت بفتره قصیره اذا ترك بدون ع تحلل المصفوفھ الخارجیھ للخالیا ومكونات الغشاء . بوعة باستزراع الخالیا السرطانیھ مكونھ حشوه سرطانیھ جدیدهفي االوعیھ الدمویھ والخروج منھا بالنسبھ للخالیا السرطانیھ مت لالورام في اھمیھ محلالت البروتین المصاحبھ . القاعدي بواسطھ محلالت البروتین یسھل أنفصال الخالیا السرطانیھ وعبورھا حدود االنسجھ وھجومھا الى االنسجھ المجاوره المستقلھ .قد تم تضمینھا على خالیا الورم اثناء الغزو واالنتشار mmp 9عائلة . عملیة الغزو واالنتشار قد تم استیضاحھا النواع من السرطانات الخبیثھ الصلبھ اربعھ وعشرون حالة ھودجكن لمفوما وثالثھ وأربعون .سبعھ وستین نسیج مثبت بالفورمالین ومطموره بشمع البرافین، مشخصھ نسیجیا لمفوما من منطقة الراس والعنق :المواد والطرق .لمعاییر العیادیھ المرضیھكمضاد احادي النسل وربط ذلك مع ا mmp 9تقنیة المناعھ الكیمیائیھ النسیجھ قد استعملت لتقییم تعبیر . الھوجكن لمفوما ورغم ذلك لم تصل الى مستوى االختالف االحصائي 21.4± 65من ما في ھودجكن لمفوما، 18± 65.4في ھودجكن والھودجكن لمفوما كان اعلى mmp 9معدل تعبیر :النتائج p>0.05 بینما معدل تعبیرmmp 9 في الورم متوسط الدرجھ و 15±68.3في الورم واطيء الدرجھ 72± 14.1وعالقتھ بدرجة الورم كان مختلف حیث كانت لھ قیمھ لم تكن لھ عالقھ أحصائیھ مھمھ بالنسبھ الى أنواع ھودجكن .p>0.05 mmp 9في الورم عالي الدرجھ وبالنتیجھ ھذا االختالف لم یصل الى المستوى االحصائي المھم 61.4±20.7 .لمفوما لم تكن ھناك أختالفات أحصائیھ مھمھ بالنسبھ الى معدل . في ھودجكن وال ھوجكن لمفوما mmp9ھ بأنھ لم تكن ھناك عالقھ مھمھ بین معدل تعبیر أظھرت ھذه الدراس :االستنتاجات .بین ھودجكن والھودجكن وأنواعھا الفرعیھ mmp 9تعبیر nidhal f.doc j bagh college dentistry vol. 25(3), september 2013 the multi-detector pedodontics, orthodontics and preventive dentistry165 the multi-detector computed tomographical analysis of bone density in impacted maxillary canines nidhal h. ghaib, b.d.s., m.sc. (1) nadia b. al-ansari, b.d.s. (2) abstract background: maxillary canines are important aesthetically and functionally, but impacted canines are more difficult and time consuming to treat, the aim of this study is to investigate with multi-detector computed tomography the correlation between the bone density and the upper canine impaction. material and method: a sample of unilaterally impacted maxillary canines from 24 patients (19 female, 5 male) who were referred to accurately localize the impacted canines at alkarkh general hospital were evaluated by a volumetric 3-d images by the multi-detector computed tomography to accurately measure the bone density of the maxillary cortical palate of the maxillary impacted canine side and compare it with the other side of the normally erupted canine. results: the statistical descriptive analysis showed that the ratio of the maxillary canine impaction was higher in females than in males, also the it revealed that the mean bone density of the cortical bone was greater in the maxillary impacted canine side (affected side) than in the control side (the side of the normally erupted canine), the wilcoxon signed ranks test showed a significant difference in the mean bone density between the affected side and the control side. conclusions: the increased bone density of the maxillary cortical plate could be an obstructive factor that cause maxillary canine impaction. keyword: multidetector computed tomography, impacted maxillary canine, bone density. (j bagh coll dentistry 2013; 25(3):165-167). introduction maxillary canines are important aesthetically and functionally, but impacted canines are more difficult and time consuming to treat (1). permanent maxillary canines are the second most frequently impacted teeth; eighty-five percent of impacted maxillary permanent cuspids are palatal impactions, and 15% are labial impactions. inadequate arch space and a vertical developmental position are often associated with buccal canine impactions. if buccally impacted cuspids erupt they do so vertically, buccally and higher in the alveolus. however due to denser palatal bone and thicker palatal mucosa, as well as a more horizontal position, palatally displaced cuspids rarely erupt without requiring complex orthodontic treatment (2). although impacted canines can be seen in tooth size arch length discrepancy, early loss of deciduous teeth, craniofacial syndromes like crouzon syndrome, cliedocranial dysostosis etc, the exact etiology of palatally impacted maxillary cuspids is unknown; however, two common theories may explain the phenomenon: the guidance theory and the genetic theory (3). the “guidance theory of palatal canine displacement” proposes that this anomaly is a result of local predisposing causes including congenitally missing lateral incisors, supernumerary teeth, odontomas, transposition of teeth and other mechanical determinants that all interfere with the path of eruption of the canine. (1)professor. department of orthodontics, college of dentistry, university of baghdad. (2)master student. department of orthodontics, college of dentistry, university of baghdad. maxillary canines develop high in the maxilla, are among the last teeth to develop and travel a long path before they erupt into the dental arch. these factors increase the potential for mechanical disturbances resulting in displacement and, thus, impaction. the second theory focuses on a genetic cause for impacted cuspids. palatally impacted maxillary cuspids often present with other dental abnormalities, including tooth size, shape, number and structure, which baccetti reported to be linked genetically (4). research demonstrates that up to 33% of patients with palatally impacted cuspids also have congenitally missing teeth, a frequency that is 4-9 times that of the general population (5). diagnosis and early detection of impacted maxillary canines may reduce treatment time, complexity, complications and cost. recently, computed tomographic scanning (ct) has been used, because it can provide more reliable information than conventional methods (6). ct provides excellent tissue contrast, eliminating blurring, overlapping of adjacent teeth, distortion and projection effects are also encountered with conventional radiographs (7). the aim of this study was to investigate with computed tomography the bone density of the maxillary cortical plate for patients with maxillary impacted canine and compare it with the other normally erupted canine side to see if there is any correlation between the bone density and the maxillary canine impaction. j bagh college dentistry vol. 25(3), september 2013 the multi-detector pedodontics, orthodontics and preventive dentistry166 materials and methods ct images were collected from 24 consecutive patients (19 female, 5 male) with unilaterally maxillary impacted canine who were referred to al-karkh general hospital /the computerized tomography department for localization of impacted maxillary canines, the patients’ ages ranged from 16 to 20 years (average=18), they were selected after meeting a special criteria (no history of general diseases that affect the bone density such as hypertension, chronic renal failure, diabetes mellitus and hormonal disorders, particularly thyroid, parathyroid, and adrenal impairment, no history of dentofacial deformities, pathologic lesions in the jaws or facial trauma). for every subject in the sample; a clinical examination was done prior to imaging, and then the patient was informed about the investigation and instructed not to move or swallow during scanning. the patients were in supine position with the cervical spine slightly overextended backward. the head was strapped to the head rest and positioned as symmetrically as possible then the computerized tomogrphic imaging was taken in the computerized tomography using multislice spiral computed tomography scanner (brilliance™ 64, philips ct, netherland). the exposure protocol was 30 ma, 80 kv, 0.6 mm slice thickness, 246 mm field of view (fov), 512x256 matrix then all images were prospectively reconstructed at 0.6 mm, using high-resolution bone filter (80 s sharp). the reconstructed transverse images (dicoms) were transferred to the workstation, and multi-planar reconstructions were generated using the included standard dental software package. to measure the bone density of the alveolar cortical bone the transaxial reconstruction plane was selected (radial vertical images perpendicular to the occlusal plane) then the cortical bone density of interest was chosen and localized precisely about 3 to 6 mm apically from the alveolar crest as shown in figure (1) and measured on both the right and left sides in hounsfield units (hu) by using the specific bone density evaluation tools provided in the philips analysis software. results the statistical analysis showed that the ratio of the female maxillary impacted canines was higher than the male ratio of maxillary canines’ impaction as seen in table 1. regarding the cortical bone density the descriptive analysis revealed that the bone density mean value for the affected side (side of canine impaction) was higher than the bone density mean value of the control side (normally erupted canine side) as shown in table 2. the inferential analysis including the wilcoxon signed ranks test that showed significant difference between both the affected side (side of canine impaction) and the control side with respect to the maxillary cortical bone density. figure 1. measuring the bone density table 1. distribution of maxillary canines according to sex gender no (%) males 5 (20 %) females 19 (80 %) total 24 table 2. the statistical analysis of the bone density discussion the results of the present study showed that the prevalence of maxillary canine impaction were higher in female than male this result supports the same results with many previous researches which indicates that women are twice as likely as men to have impacted maxillary canines (8). the etiology of impacted maxillary canines is thought to be multifactorial, but the exact etiology is still unclear (9,10). many studies were done previously trying to find the exact cause of maxillary canine impaction some of them relate the impaction to local obstructive causes other groups descriptive statistics group difference median mean s.d. wilcoxon signed ranks test pvalue study 1197.5 1102.25 333.64 -2.54 0.011 control 925.5 954.5 325.20 j bagh college dentistry vol. 25(3), september 2013 the multi-detector pedodontics, orthodontics and preventive dentistry167 studies relate the impaction to systematic disorder, in this research we are attempting to find if there is any correlation between the canine impaction and the bone density ,and the result of this study showed a marked increase in the mean bone density in the side of the canine impaction , also the inferential test showed a significant difference in the bone density between the normally erupted canine side and the other impacted canine side of the same patient which indicates that the bone density could be a cause for palatal canine impaction. references 1. deng-gao liu, wan-lin zhang, zu-yan zhang. localization of impacted maxillary canines and observation of adjacent incisor resorption with conebeam computed tomography. oral and maxillofacial radiology 2008; 105(1): 91-8. 2. gupta a, makhija p, bhatia v, navlani m, virang b. impacted caninediagnosis and prevention. webmed central dentistry 2012. 3. bishara se. impacted maxillary canines: a review. am j orthod dentofac orthop 1992; 101:159-71. 4. baccetti t. a controlled study of associated dental anomalies. angle orthod 1998; 68: 267-74. (ivsl). 5. brin i, becker a, shalhav m. position of the maxillary permanent canine in relation to anomalous or missing lateral incisors: a population study. eur j orthod 1986; 8:12-6. 6. ericson s, kurol j. ct diagnosis of ectopically erupting maxillary canines—a case report. eur j orthod 1988; 10:115-21. 7. bodner l, bar-ziv j, becker a. image accuracy of plain film radiography and computerized tomography in assessing morphological abnormality of impacted teeth. am j orthod dentofac orthop 2001; 120: 6238. 8. park j, srisurapol t, tai k. impacted maxillary canines: diagnosis and management. dent today j 2012; 31(9): 62, 64-6; quiz 68-9. 9. rajic s, muretic z, percac s. impacted canine in a prehistoric skull. angle orthod 1996; 66: 477-80. (ivsl). 10. bedoya mm, park jh. a review of the diagnosis and management of impacted maxillary canines. j am dent assoc 2009; 140: 1485-93. figure 2. a 16 years old patient with impacted maxillary canine j bagh college dentistry vol. 29(3), september 2017 salivary physicochemical among pedodontics, orthodontics and preventive dentistry 68 salivary physicochemical characteristics in relation to oral health status among institutionalized autistic adolescents in baghdad/iraq ali hadi f. al-fatlawi, b.d.s., m.sc. (1) nada jafer mh. radhi, b.d.s., m.sc., ph.d. (2) abstract background: autism spectrum disorder (asd) is characterized by impairments in social interaction and communication, restricted patterns of behavior, and unusual sensory sensitivities. saliva may provide an easily accessible sample for analysis. some salivary constituents levels altered in adolescents with asd including antioxidants . this study aimed to investigate salivary physicochemical characteristic in relation to oral health status among adolescents with asd. materials and methods: two groups were included in this study: 40 institutionalized autistic adolescents and 40 apparently healthy school adolescents control group with age range (12-15 years old, only males) selected randomly from baghdad. each group subdivided into two groups according to the severity of dental caries: caries free group (20 child, dmft=0) and high caries group (20 child, dmft≥6). decayed, missing and filled surfaces (dmfs), plaque (pli), gingival (gi) and calculus (ci) indices were used to measure oral health status for both groups. copper (cu), zinc (zn) and thiocyanate (scn) in saliva measured by atomic absorption spectrophotometer. salivary alpha amylase (saa) and glutathione (gsh) assessed by enzyme-linked immunosorbent assay (elisa). salivary ph and flow rate were measured directly. the data of current study was analyzed using spss version 21. results: a higher value of salivary ph, flow rate, saa, scn, cu and zn were found among study group than control group with significant difference, also higher in caries free subgroup than high caries subgroup. while gsh was significantly higher in control group than study group. moderate negative correlations between saa, cu, zn and pli, ci, gi with highly significant and salivary ph correlate moderately with pli and ci with highly significant. conclusion: there was alteration in salivary constituents levels which related to oral health status in adolescents with asd and can act as adjunctive diagnostic aid for diagnosing autism. keywords: autism spectrum disorder; saa; scn; gsh. (j bagh coll dentistry 2017; 29(3):68-74) introduction autism spectrum disorders (asd) is a neurodevelopmental disorder in which social interaction, language, behavior and cognitive functions are impaired severely (1). it is characterized by a complex, behaviorally defined, static immature brain disorder that is of great concern to various professions (2). individuals with asd may have less learning abilities than healthy individuals. this may affect their oral hygiene (3). various studies in the past have shown a higher prevalence of periodontal disease and a lower caries in autistics compared to unaffected children (2,4,5). oral fluid or whole saliva is an important complex chemical milieu of teeth and oral soft tissues, which maintains the homeostasis of the oral cavity (6). the most abundant protein in saliva is alpha amylase (saa), accounting for approximately 20% of salivary proteins. thiocyanate (scn) is an important physiological anion involved in innate defense of mucosal surfaces. ______________________________________________ (1) ph.d. student, department of pediatric and preventive dentistry, college of dentistry, baghdad university. (2) assist. professor, department of pediatric and preventive dentistry, college of dentistry, baghdad university. there are indispensable parts of host defense system that act as a substrate for lactoperoxidase that oxidizes airway surface lipid thiocyanate thereby generating antimicrobial agent hypothiocyanate (7). copper (cu) ions have been reported to have an antibacterial effect. it was suggested that there is an altered regulation of ceruloplasmin in a subset of children with autism. such alterations may lead to abnormal copper metabolism that may play a pathological role in autism (8). zinc (zn) can reduce dental calculus formation, control plaque and reduce the solubility of enamel. in fact, some preliminary studies suggested altered serum cu/zn ratios in autism (8,9). the antioxidant defense system of saliva has several components. one of these antioxidants is glutathione (gsh), salivary gsh levels decrease in periodontal diseases and dental caries (10). individuals with asd showed elevated levels protein, scn, and saa when compared to normal children. antioxidant enzymes, cholesterol and gsh levels were found to be decreased in asd than in normal children (7). as far as, no previous study was conducted among institutionalized autistic adolescents in baghdad regarding the relation between physicochemical characteristic of saliva, dental j bagh college dentistry vol. 29(3), september 2017 salivary physicochemical among pedodontics, orthodontics and preventive dentistry 69 caries and gingival health. for all these explanation, this study was designed. materials and methods the study included two male groups: 40 institutionalized autistic children and 40 apparently healthy schoolchildren with age range (12-15 years old, only males). the sample selected according to the severity of dental caries. each group subdivided into two groups: caries free group (20 child, dmft=0) and high caries group (20 child, dmft≥6). for all children intra-oral assessment of caries experience was measured according to criteria of who (1997) (11), oral hygiene status was evaluated by application plaque index (pli) of silness and löe (12), and calculus index (ci) of ramfjord (13). gingival inflammation assessed by using gingival index (gi) of löe and silness (14). for salivary samples each child was asked to sit down and relaxes as much as possible and was asked to chew a piece of arabic gum for one minute before all the saliva was removed by expectoration; chewing was then continued for ten minutes with the same piece of gum and the collection of saliva by spitting was done during this time (15). the collected saliva was centrifuged at 1000 rpm for 10 minutes; this done after 1 hour after collection to eliminate debris and cellular matter. the centrifuged supernatants stored frozen at (-20°c) in polyethylene tube until assayed. salivary flow rate assessed by dividing the total volume of saliva collected in milliliter over the time of collection in minute. ph of saliva was measured by using ph meter. copper and zinc in saliva were measured by atomic absorption spectrophotometer using commercial kits (spectrum, germany). salivary thiocyanate assessed according to the method described by slowinski et al. using spectrophotometer (16). salivary alpha amylase and glutathione measured by enzyme-linked immunosorbent assay (elisa) using special commercial kits (cloud-clone corp., usa). the mean values with sd were measured for all tested salivary variables. the statistical significance, direction and strength of linear correlation between two quantitative normally distributed variables, by pearson’s rank linear correlation coefficient. p value less than the 0.05 level of significance was considered statistically significant. a receiver operating characteristic (roc), or simply roc curve, is a graphical plot which illustrates the performance of a binary classifier system as its discrimination threshold is varied. all analyzed tests were bilateral. results table 1 shows mean values of ph and flow rate (ml/min) in stimulated saliva among study and control groups by caries severity. a higher value of salivary ph and flow rate were found among study compared to the control group, which was statistically high significant with ph (p<0.001) and flow rate (p=0.003). a higher value of salivary ph and flow rate were found among caries free subgroup than high caries subgroup, which was statistically high significant with ph (p<0.01) and not significant difference with flow rate (p>0.05). the correlation coefficients of salivary ph and flow rate with pli, gi and ci among study and control groups are illustrated in table 2. in study group, data of present study shows that a moderate negative correlations between salivary ph and pli, ci. in control group, a strong negative correlation between salivary ph and pli, gi, ci. a moderate negative correlation between salivary flow rate and pli, ci among control group. the mean values of all salivary constituents were found higher in caries free than high caries subgroup among study group with high significant differences for saa, cu and zn. as shown in table 3. table 4 demonstrates the mean concentration of salivary constituents in (µg/dl) among study and control groups with statistical differences. a higher mean value of salivary saa, scn, cu, zn, and cu/zn were found among study compared to the control group, with high statistical significant difference for saa, scn and cu, while significant difference with zn. mean value of gsh was lower in study group than control group with high significant difference. figure 1 and table 5 demonstrate the areas under roc curve for saa (0.838), cu (0.813) and zn (0.763) were significantly from 0.5 value of an equivocal test (p<0.001 for saa, cu and p= 0.005 for zn), whereas the areas under roc curve for cu/zn (0.621), scn (0.616) and gsh (0.501) were not significantly different from 0.5 value of an equivocal test. figure 2 and table 6 show the areas under roc curve for salivary gsh (0.858), scn (0.821), saa (0.786), cu (0.652) and zn (0.648) were significantly from 0.5 value of an equivocal test (p<0.001 for gsh, scn, saa; p= 0.019 for cu; p= 0.023 for zn), whereas the areas under roc curve for cu/zn (0.538) was not significantly different from 0.5 value of an equivocal test. j bagh college dentistry vol. 29(3), september 2017 salivary physicochemical among pedodontics, orthodontics and preventive dentistry 70 table 7 demonstrates the correlation coefficients of salivary constituents with pli, gi and ci among study and control groups. in study group, a moderate negative correlations between saa, cu, zn and pli, gi, ci. a very weak negative correlation between gsh, scn, cu/zn and pli, gi, ci. in control group, a moderate negative correlation between zn and pli as well as ci, while a very weak negative correlation was seen regarding saa, gsh, scn. a weak negative correlation between cu and pli, ci. disscusion autism spectrum disorder is a neurodevelopment disorder characterized by impaired social interaction and behavior, which can have adverse influence on dental care and oral health in the affected individuals. studies on oral health in individuals with asd have conflicting results. in a population-based sample of autistic children and adolescents, parents reported poorer condition of their children’s teeth and gingiva compared to other children (17,18,19). this study recorded an increasing in the flow rate and ph of stimulated saliva in the study group which was statistically significant compared to control group. individuals with asd report more stress in everyday life and they also report a higher level of dental anxiety, both factors that may negatively affect salivary secretion. these results disagreement with other studies (5,18,20). alpha-amylase is a calcium-dependent metalloenzyme which can hydrolyze starch to glucose and maltose; consequently, having an important role in binding to bacteria (21). in the present study, saa was higher in study group compared to control group with highly significant difference. in addition, saa was higher in caries free subgroup than high caries subgroup with highly significant difference. saa activity is an increasingly investigated biomarker for the activation of the autonomic nervous system. hence, the high activity of αamylase in autistic children shows that there is hyperstimulation of autonomic nerves, which may be associated with hyperactive nature of autistic children. this result in line with other studies (7,22). glutathione is a family of multifunctional enzymes that plays an important role in the detoxification of xenobiotics including carcinogens. in addition, gsh plays a critical role in cellular protection against oxidative stress and toxic foreign chemicals. the level of salivary gsh was lower in asd group compared to control group with highly significant differences. in addition, there is a slight increase of gsh level in high caries subgroup in relative to caries free subgroup among asd group with non-statistical differences, and this might be due to lack of the substrate gsh and hence may be accounted for the reduced detoxifying capacity of gsh in autistic children. the activity of the enzyme may possibly be affected, if there is any genetic polymorphism in gst (23). this result was supported by other studies (24,25,26). thiocyanate is an important physiological anion involved in innate defense of mucosal surfaces. it is a metabolite of cyanide and the product of detoxification of compounds containing cyanide through a reaction catalyzed by the enzyme rhodanese (27). in the current study, the concentration of salivary scn was higher in study group than control group with highly significant differences. in addition, the level of salivary scn was slightly higher in caries free subgroup than high caries subgroup among asd group, but with non-significant differences. the elevated scn level in asd group may be attributed to low rhodanese activity as supported by waring and klovrza (28), who stated that the raised ratio of thiosulfate and scn might be due to reduced rhodanese activity. scientists interested the relationship between salivary trace elements (zn and cu) and dental caries activity for many years. conflicting reports from researchers who have investigated cu and zn in saliva indicate that the nature of the role that these elements play in the carious process remains undefined (29). elevated level of cu and depressed zn have been associated with asd, attention deficit disorders and depression (30). in this study, the concentration of cu and zn were higher in study group than control group with significant differences, in addition, the level of cu and zn were higher in caries free subgroup than high caries subgroup among study group with highly significant differences. this may be attributed to the antimicrobial properties of cu and zn, which include acute loss of bacterial intracellular k+ and inhibition of h—atp synthase, inhibition of various bacterial metabolic enzymes through oxidation of key thiol groups, and formation of insoluble salts on the tooth surface, thereby increasing its acid resistance (31). references 1. friedlander ah, yagiela ja, paterno vi, mahler me. the neuropathology, medical management and dental implications of autism. j am dent assoc 2006; 137: 1517–27. j bagh college dentistry vol. 29(3), september 2017 salivary physicochemical among pedodontics, orthodontics and preventive dentistry 71 2. luppanapornlarp s, leelataweewud p, putongkam p, ketanont s. periodontal status and orthodontic treatment need of autistic children. world j orthod 2010; 11: 256– 61. 3. pilebro c, backman b. teaching oral hygiene to children with autism. int j paediatr dent 2005; 15: 1–9. 4. rai k, hegde am, jose n. salivary antioxidants and oral health in children with autism. arch oral biol 2012; 57: 1116–20. 5. blomqvist m, bejerot s, dahllöf g. a cross-sectional study on oral health and dental care in intellectually able adults with autism spectrum disorder. bmc oral health 2015; 5: 81. 6. amado fm, vitorino rm, domingues pm, lobo mj, duarte ja. analysis of the human saliva proteome. expert rev proteomics 2005; 2(4): 521-39. 7. suganya v, umashangeethapriy d, lakshmi m, geetha a, sujatha s. analysis of salivary components to evaluate the pathogenesis of autism in children. asian j pharm clin res 2014; 7(4): 205–211. 8. zahir s, sarkar s. study of trace elements in mixed saliva of caries free and caries active children. j indian soc pedod prev dent 2006; 24: 27–29. 9. chauhan a, chauhan v, brown wt and cohen i. oxidative stress in autism: increased lipid peroxidation and reduced serum levels of ceruloplasmin and transferrin the antioxidant proteins. life sci 2004; 75 (21): 2539–49. 10. vojdani a, mumper e, granpeessheh d. low natural killer cell cytotoxic activity in autism: the role of glutathione, il-2 and il-15. j neuroimmunol 2008; 205: 148–154. 11. who. oral health surveys basic methods. 4th ed. world health organization. geneva, switzerland, 1997. 12. silness j, löe h. periodontal disease in pregnancy: correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22: 121–135. 13. ramfjord sp. indices for prevalence and incidence of periodontal disease. j perio 1959; 30: 51–59. 14. löe h and silness j. periodontal disease in pregnancy. acta odontol scand 1963; 21: 533–551. 15. ali r. odontometric measurements and salivary cortisol among low birth weight 5 years old kindergarten children in relation to dental caries. master thesis, college of dentistry, university of baghdad, 2013. 16. lahti m, vilpo j, hovinen j. spectrophotometric determination of tiocyanate in human saliva. j chem educ 1999; 76: 1281–2. 17. kopycka-kedzierawski dt, auinger p. dental needs and status of autistic children: results from the national survey of children's health. pediatr dent 2008; 30: 54– 8. 18. bassaoukou ih, nicolau j, dos santos mt. saliva flow rate, buffer capacity, and ph of autistic individuals. clin oral investig 2009; 13: 23–27. 19. loo cy, graham rm, hughes cv. the caries experience and behavior of dental patients with autism spectrum disorder. jada 2008; 139: 1518–24. 20. gunawan i, wibowo t, pradopo s. salivary ph conditions in children patients with mild autism and normal children. indonesian pediat dent j 2010; 2: 2. 21. harris n, garcia-godoy f, nathe cn. primary preventive dentistry. 7th ed. london: asimon and schuster company, 2009. 22. mojarad f, fazlollahifar s, poorolajal j, hajilooi m. effect of alpha amylase on early childhood caries: a matched case-control study. braz dent sci 2013; 16: 1. 23. williams ta, mars ae, buyske sg, stenroos es, wang r, factura-santiago mf, et al. risk of autistic disorder in affected offspring of mothers with a glutathione s-transferase p1 haplotype. arch pediatr adolesc med 2007; 161(4): 356–61. 24. al-gadani y, el-ansary a, attas o, al-ayadhi l. metabolic biomarkers related to oxidative stress and antioxidant status in saudi autistic children. clinical biochemistry 2009; 42; 1032–40. 25. geier, kern, geier. a prospective study of oxidative stress biomarkers in autistic disorders. electronic j applied psychology 2009; 5(1): 2–10. 26. rasheed m. assessment of serum and salivary oxidative stress biomarkers with evaluation of oral health status in a sample of autistic male children. m.sc. thesis, college of dentistry, university of baghdad, 2011. 27. wang gf, li mg, gao yc, fang b. amperometric sensor used for determination of thiocyanate with a silver nanoparticles modified electrode. sensors 2004; 4(9):147–55. 28. waring rh, klovrza lv. sulphur metabolism in autism. j nutr environ med 2000; 10: 25–32. 29. irving g, lantana d, sunnyvale. copper and manganese in saliva of children. den res j 2010; 49(4): 776–782. 30. osredkar j, sustar n. copper and zinc. biological role and significance of copper/zinc imbalance. j clinic toxicol 2011; s3: 001. 31. stipanuk mh. biochemical, physiological & molecular aspects of human nutrition. saunders company; 2006. j bagh college dentistry vol. 29(3), september 2017 salivary physicochemical among pedodontics, orthodontics and preventive dentistry 72 table 1: mean values of salivary ph and flow rate among study and control groups by caries severity with statistical difference. table 2: correlation coefficients of salivary ph and flow rate with plaque, gingival and calculus indices among study and control groups. * significant, ** highly significant table 3: mean values of salivary constituents (µg/dl) among study group by caries experience with statistical differences. ** highly significant table 4: mean values of salivary constituents (µg/dl) among study and control subgroups with statistical differences. salivary parameters subgroups study control statistical difference (mean ± sd) (mean ± sd) t-value p-value ph caries free 7.71 ± 0.36 7.29 ± 0.36 3.718 < 0.001** high caries 7.19 ± 0.44 6.51 ± 0.46 4.757 < 0.001** total 7.45 ± 0.48 6.90 ± 0.57 4.689 < 0.001** flow rate (ml/min) caries free 1.75 ± 0.21 1.61 ± 0.22 2.062 0.046* high caries 1.65 ± 0.29 1.41 ± 0.34 2.476 0.018* total 1.70 ± 0.25 1.51 ± 0.30 3.103 0.003** groups salivary parameters pii gi ci r p r p r p study ph -0.491 < 0.001** -0.281 0.079 -0.421 0.007** flow rate -0.182 0.262 -0.277 0.084 -0.219 0.175 control ph -0.675 < 0.001** -0.527 < 0.001** -0.556 < 0.001** flow rate -0.321 0.043* -0.246 0.126 -0.337 0.033* salivary variable caries free high caries t-value p-value mean sd mean sd α-amylase 10.39 0.80 9.24 0.87 4.311 < 0.001** glutathione 0.91 0.61 0.87 0.56 0.197 0.845 thiocyanate 105.39 13.25 100.02 10.75 1.408 0.167 copper 37.92 11.57 25.24 8.03 4.026 <0.001** zinc 82.18 14.40 65.15 16.75 3.448 <0.001** cu/zn 0.48 0.19 0.40 0.14 1.428 0.162 groups study control statistical difference (mean ± sd) (mean ± sd) t-value p-value α-amylase 9.81 1.01 8.63 1.07 5.113 <0.001** glutathione 0.89 ± 0.58 2.20 ± 1.10 6.626 <0.001** thiocyanate 102.70 ± 12.21 87.21 ± 11.14 5.929 <0.001** copper 31.58 ± 11.74 25.21 ± 9.15 2.708 0.008** zinc 73.66 ± 17.67 64.05 ± 16.64 2.505 0.014* cu/zn 0.44 ± 0.17 0.41 ± 0.16 0.729 0.468 * significant, ** highly significant * significant, ** highly significant j bagh college dentistry vol. 29(3), september 2017 salivary physicochemical among pedodontics, orthodontics and preventive dentistry 73 figure 1: roc curve for selected quantitative measurements when used to differentiate caries free subgroup from high caries subgroup among study group. table 5: area under roc curve selected quantitative measurements when used to differentiate caries free subgroup from high caries subgroup among study group. ** highly significant figure 2: roc curve for selected quantitative measurements when used to differentiate study group from control group. tested variable area under the curve p-value alpha amylase 0.838 < 0.001** copper 0.813 < 0.001** zinc 0.763 0.005** cu/zn ratio 0.621 0.190 thiocyanate 0.616 0.199 glutathione 0.501 0.989 j bagh college dentistry vol. 29(3), september 2017 salivary physicochemical among pedodontics, orthodontics and preventive dentistry 74 table 6: area under roc curve selected quantitative measurements when used to differentiate study group from control group. * significant, ** highly significant table 7: correlation coefficient between salivary constituents and plaque, gingival, calculus indices among study and control groups. ** highly significant الخالصة ( بضعف في التفاعل االجتماعي والتواصل، أنماط محدودة من السلوك وتحسس حسي غير عادي. امراض الفم asdيتميز اضطراب طيف التوحد ) :المقدمة االسنان وذلك بسبب المظاهر السريرية المعقدة والمتنوعة تكون غير محددة للغاية لدى األفراد الذين يعانون من اضطراب التوحد اال انها تشكل تحد كبير ألطباء الكيميائية للعاب فيما يتعلق بصحة الفم للمراهقين الذين يعانون من اضطراب التوحد في بغداد.-الخاصة بهم. تهدف الدراسة لبحث الخواص الفيزيائية التوحد معاهد رعايةمراهق يعانون من اضطراب التوحد تم اختيارهم من 04مجموعة الدراسة وتتكون من تضمنت الدراسة مجموعتين: :والطرق المواد ( سنة ومن الذكور فقط. كل مجموعة قسمت الى 21-21مراهق سليم من المدارس الثانوية القريبة لمعاهد رعاية التوحد وبعمر ) 04ة وتتكون من سيطرومجموعة ال (، dmfsاستخدام مقاييس تسوس االسنان )(. dmft≥6( ومجوعة عالية التسوس )dmft=0مجموعتين وفقا لشدة التسوس: مجموعة خالية التسوس ) ( تم scn( والثايوسيانيت )zn(، الزنك )cu( لتقييم صحة الفم واالسنان للمجموعتين. كال من النحاس )ci( والقلح )gi(، التهاب اللثة )pliاللويحة الجرثومية ) (. بينما الفا اميليز والجلوتاثيون تم قياسهم باستخدام تقنية قياس االنزيم المناعي المرتبط spectrophotometerالذري )قياسهم باستخدام جهاز معامل االمتصاص (elisa.) تم تحليل بيانات الدراسة الحالية باستخدام برنامجspss 12النسخة . في مجموعة الدراسة اعلى من أظهرت الدراسة ان قيم كال من االس الهيدروجيني للعاب، سرعة تدفق اللعاب، الفا اميليز، ثايوسيانيت، النحاس والزنك النتائج: في توى الجلوتاثيونة وبفارق معنوي، كذلك هذه القيم في المجموعة خالية التسوس اعلى من المجموعة عالية التسوس وبفارق معنوي. بينما مسسيطرمجموعة ال مقياس (، pli)ة. وجود عالقة ارتباط متوسطة عكسية بين الفا اميليز، النحاس والزنك مع مقياس اللويحة الجرثومية سيطرمجموعة المجموعة الدراسة كان اقل من القلح ( وpli)متوسطة بمقياسي اللويحة الجرثومية ( وبفارق معنوي عالي، وكذلك االس الهيدروجيني للعاب يرتبط بعالقةgi( ومقياس صحة اللثة )ciالقلح ) (ci.وبفارق معنوي عالي ) وعة مجماعلى من حد قيم كال من االس الهيدروجيني للعاب، سرعة تدفق اللعاب، الفا اميليز، ثايوسيانيت، النحاس والزنك في مجموعة اضطراب التو ان :االستنتاج د مقارنة مجموعة اضطراب التوح خالية التسوس اعلى من المجموعة عالية التسوس. بينما الجلوتاثيون كان اقل فية، وجميع هذه القيم في المجموعة السيطر .ةلسيطرمجموعة اب tested variable area under the curve p-value glutathione 0.858 < 0.001** thiocyanate 0.821 < 0.001** alpha amylase 0.786 < 0.001** copper 0.652 0.019* zinc 0.648 0.023* cu/zn ratio 0.538 0.564 groups salivary constituents pli gi ci r p r p r p study amylase -0.537 < 0.001** -0.460 0.003** -0.491 < 0.001** glutathione -0.016 0.924 -0.028 0.866 -0.023 0.890 thiocyanate -0.043 0.790 -0.101 0.534 -0.225 0.162 copper -0.577 < 0.001** -0.493 < 0.001** -0.539 < 0.001** zinc -0.526 < 0.001** -0.546 < 0.001** -0.560 < 0.001** cu/zn -0.278 0.082 -0.209 0.195 -0.181 0.263 control amylase -0.089 0.587 -0.078 0.631 -0.245 0.127 glutathione -0.097 0.553 -0.094 0.564 -0.162 0.317 thiocyanate -0.120 0.460 -0.194 0.230 -0.097 0.551 copper -0.221 0.170 -0.089 0.583 -0.263 0.101 zinc -0.415 0.008** -0.163 0.315 -0.500 < 0.001** cu/zn 0.069 0.670 -0.025 0.877 0.118 0.467 raed.doc j bagh college dentistry vol. 25(special issue 1), june 2013 the effects of pedodontics, orthodontics and preventive dentistry146 the effects of different concentrations of alum solutions on mutans streptococci (in vitro study) raed f. ai-huwaizi, b.d.s., h.d.c.d., m.sc. (1) wael s. al-alousi, b.d.s., m.d.sc. (2) abstract background: alum has been used as a treatment medication in cases of oral and gingival ulcers, and also as antiseptic mouthwash. this study aimed to examine the effects of different concentrations of alum on inhibition zone, viability counts and adherence ability of mutans streptococci compared with deionized water and chlorhexidine gluconate in vitro. materials and methods: the study dealt with an in vitro study to establish a concentration of alum mouthrinse that would have the minimum inhibitory concentration and minimum bacteriocidal concentration. the second part evaluated the anti-adherence ability of the experimental agents. results: this study found that the antibacterial effect of alum increases with its concentration from 50 to 10000 ppm but still weaker than 0.1% chlorhexidine gluconate. only concentrations of 5000 and 10000 ppm showed negative adherence of mutans streptococci to the tooth surface. conclusions: this study found that the antibacterial effect of alum increases with its concentration from 50 to 10000 ppm but still weaker than 0.1% chlorhexidine gluconate. only concentrations of 5000 and 10000 ppm showed negative adherence of mutans streptococci to the tooth surface. key words: alum, chlorhexidine, mutans streptococci. (j bagh coll dentistry 2013; 25(special issue 1):146-151). introduction potassium alum, k2so4·al2(so4)3·24h2o, crystallizes in regular octahedra and is very soluble in water. the solution reddens litmus and is an astringent. alum is used in cases of gingivitis (1,2), in management of mucositis (3) and oral ulcers when it was noticed that the treatment of recurrent aphthus ulcerations with alum in concentrations of 1000, 2000, and 4000 ppm was significant in enhancing the healing procedure of the ulcers (4). aluminum salts have demonstrated anticaries activity in a number of laboratory and animal studies (1,5) and was proved to be significant as alum mouthrinse in prolonged daily use of the mouthrinse for decreasing the level of mutans streptococci in saliva (three and six weeks) (6), and also the effect of an alum mouthrinse on dental caries formation both by itself and in combination with an ada-approved sodium fluoride dentifrice (7). it was concluded that daily supervised use of an alum mouthrinse inhibited caries development in decay-prone children at least as effectively as a fluride dentifrice (1,5). olmez et al (8) assessed the effect of daily supervised rinsing with a specially formulated, alum-containing mouthrinse on plaque and salivary levels of s. mutans, s. mitis and s. salivarius in caries susceptible children (12-14 years old) and to monitor the effect on the oral tissues and acceptability to subjects. (1) lecturer, college of dentistry, university of kufa. (2) professor, college of al-yarmook he concluded a daily use of an alumcontaining mouthrinse was safe and produced significant reduction effect on plaque and salivary levels of oral streptococcus and can be used in children for the preventive dentistry. some authors introduced alum in dentifrices and investigated a comparative three-year caries protection from an aluminum-containing and a fluoride-containing toothpaste and concluded that after 3 years, the mean caries increment was significantly higher in the group using the aluminum-containing toothpaste measured both clinically and radiographically (9). the effects of solutions containing various aluminum concentrations (alum) on formation of smooth surface and sulcal caries in cariogenically challenged rats infected with streptococcus sobrinus was investigated using aik(so4)2 solutions containing 100, 1000, 2000, or 4000 ppm. results showed that topically applied aluminum reduced the formation and progression of both smooth surface and sulcal caries and showed evidence of a dose response in a rat model infected with s. sobrinus (10-12). it was found that aluminum reduced enamel dissolution in a ph 4 acetate buffer most effectively when used in the ph range of 3 to 4, at concentrations above 0.005 mol/l, and for treatment times of more than four minutes (13). however, significant activity was observed with concentrations as low as 0.0005 mol/l aluminum and treatment times as short as 15 seconds. the effects of aluminum solution ph and concentration on enamel dissolution were related to the hydrolysis of aluminum above ph 4 and to j bagh college dentistry vol. 25(special issue 1), june 2013 the effects of pedodontics, orthodontics and preventive dentistry147 the accelerated dissolution of apatite below ph 3 (14-16). a sodium-potassium aluminum silicate cleaning and polishing agent was compared with conventional prophylaxis abrasives and was found to be highly compatible with fluoride. when formulated into a fluoride prophylaxis paste, especially with stannous fluoride, a larger reduction in enamel solubility and greater fluoride uptake were obtained with representative commercial prophylaxis pastes (17). the study aimed to evaluate the effect of different concentrations of alum (50 10000 ppm) on the inhibition zone, viability counts and adherence ability of mutans streptococci in vitro. materials and methods media preparation: a) preparation of phosphate buffer saline (pbs): a phosphate buffer saline of ph 7.0-7.2 was prepared by dissolving a tablet of phosphate buffer (ldh) in 100 ml of deionized water and spread in ten test tubes (9.9ml) and sealed with a piece of cotton and tin foil and then sterilized in the autoclave. then it was left to cool down and finally stored in the fridge until the time of its use. b) mitis salivarius agar (msa): it is a selective medium was used for the cultivation of total streptococci. the medium was prepared and sterilized according to the manufacturer's directions (himedia, india). its ph was adjusted to 7.2 by adding naoh or hcl and then sterilized by autoclave. after the media cooled to 45-50°c, 20 ml was poured in each plate and left to cool down to room temperature. the plates were collected and turned upside-down and sealed, and finally stored in the fridge until time of use. c) mitis salivarius bacitracin agar (msba): this medium is selective for the cultivation of mutans streptococci. the selective property is determined by the addition of the selective agents, sucrose and bacitracin (applichem, germany), at the optimal levels determined to the msa composition to be effective in inhibiting bacteria other than mutans streptococci since the relative resistance of mutans streptococci to high concentration of both sucrose and bacitracin had been reported (18). bacitracin stock solution was prepared by dissolving 0.364 gm powder in 100 ml of deionized water to give 200 iu/litre concentration (1 unit bacitracin= 0.0182 mg). then it was sterilized by 0.45µm millipore filtering (19) and kept in the fridge. a new fresh solution was prepared every 2-3 weeks. msa was prepared as described above. sucrose was added to obtain a concentration of 150 gm per one liter of the medium (18). the media ph was adjusted to 7.2 by adding naoh or hcl and then sterilized by autoclave. after the media cooled to 45°c, bacitracin stock solution was added under aseptic conditions. then the media was poured into plates and left it to cool for 24 hours at room temperature and store it in the fridge until use. d) mueller hinton agar (mha): this was prepared according to manufacturer instruction, which involved the suspension of 35 gm in one liter of distilled water. after being completely dissolved with boiling, it was autoclaved at 121ºc for 15 minutes. finally, kept tightly closed in a cool dry place. e) tryptose phosphate broth (tpb): it is composed from the following ingredients: tryptose 20 gm (oxide) dextrose 2.0 gm (difco) sodium chloride 2.0 gm (bdh) di-sodium hydrogen phosphate 2.5 gm these were dissolved in one liter of distilled water (ph 7.2) distributed in screw-capped bottles (10 ml each) sterilized by autoclave, then stored in the fridge till use. isolation and purification of mutans streptococci collection of the stimulated salivary samples: stimulated saliva was collected from a 26 year old healthy male under the conditions following the criteria described by tenovuo and lagerlof (20); by asking the volunteer not to take antibiotic for the last two week before the collection of the samples and not to eat or to drink (except water) for an hour before the collection of the samples. the volunteer did not have any illnesses or diseases. the volunteer was seated in a relaxed position on an ordinary chair. the saliva collection includes the following steps: chewing a piece of arabic gum (0.35–0.4 gm) for 1 minute and then expectorate to remove all saliva. chewing a small piece of the gum (0.35-0.4 gm) for 10 minutes and collecting the saliva. after collection and disappearance of salivary foam, 0.1 ml of saliva is transferred to 0.9ml of sterile phosphate buffer saline (ph 7.0) for microbiological analyses. within less than 15 minutes, the ph of the saliva was measured by the digital ph meter and the volume and the rate of secretion were measured. j bagh college dentistry vol. 25(special issue 1), june 2013 the effects of pedodontics, orthodontics and preventive dentistry148 isolation of mutans streptococci: ten-fold dilutions of saliva were performed by transferring 0.1 ml of from each suspension to 0.9 ml of sterile phosphate buffer saline (ph 7.0). each suspension was agitated well using vortex mixer for two minutes. from dilutions 10-3 and 10-5 of salivary samples, 0.1 ml was taken and spread in duplicate on the selective media mitis salivarius bacitracin agar (msb). plates were incubated anaerobically using a gas pack (bd bbltm, usa) or 48 hours at 37°c, then aerobically for 24 hours. the examination and diagnosis of colonies incubated was done according to the following criteria: 1morphological characteristics: mutans streptococci were examined under dissecting microscope (magnification x15). diagnosis was according to their morphological characteristics on msb agar plates (fig. 1), according to the criteria described by edwardsson (21). 2gram’s stain (crescent diagnostics, ksa): colonies were picked up from the msb agar plates under the microscope and subjected to gram’s stain method (22). mutans streptococci are gram positive, appear small ovoid or spherical in shape in small or medium chains (23) (fig. 2). 3biochemical tests: a colony of mutans streptococci was elevated from each msb agar plate under a microscope inoculated in 10 ml of sterile tpb. when two types of colonies were observed in one plate, each colony was picked up and inoculated separately. broths were incubated aerobically at 37°c for 18 hours, there after the following tests were conducted (fig. 3). carbohydrate fermentation test: the ability of mutans streptococci to ferment sugars was tested by the addition of a selected carbohydrate (sorbitol and mannitol) in a concentration of 1% to bhi broth (himedia, india) in a presence of an indicator (bromocresol purple, bdh). carbohydrate utilization broth was prepared by dissoliving 10 gm carbohydrate in one liter brain heart infusion broth and adding 1 ml bromocresol purple (1.6% in 95% ethanol) (fig. 4a & b). the broth was distributed into test tubes (3ml each) and autoclaved. each incubated aerobically at 37ºc for four days. change in the color from red to yellow indicated a positive reaction, in comparison to control positive (broth and bacteria only) and control negative (broth and sugar with out bacteria) (24). maintenance of bacterial isolates: isolates of mutans streptococci were checked for purity by re-inoculation on msb agar plates incubated anaerobically for 48 hours at 37ºc followed by another incubation aerobically for 24 hours. a selected colony was transferred to 10 ml of sterile tpb (ph 7.0), incubated for 24 hours aerobically at 37ºc. broth was stored in fridge until use. this procedure was repeated monthly. part one this involved bacteriological analyses of an in vitro study to establish a concentration of alum (bdhgreat britain) mouthrinse that has the mic and mbc. bacterial inoculum used in all sets of in vitro experiments were prepared by addition of pure isolates of mutans streptococci in concentration of 1% to 10 ml of sterile bhi broth (ph 7.0), incubated aerobically for 18 hours (25). determination of mic and mbc a serial dilution method was applied to identify the lowest concentration of alum that inhibited the growth of mutans streptococci (26). the experiment was carried out on eleven isolates of mutans streptococci with different concentrations of alum (50, 100, 250, 500, 1000, 2000, 5000, 10000 ppm) compared with chlorhexidine (0.1% and 0.2%) and deionized water as control. figure 1: colonies of mutans streptococci. figure 2: gram’s stain positive view of a slide. j bagh college dentistry vol. 25(special issue 1), june 2013 the effects of pedodontics, orthodontics and preventive dentistry149 figure 3: tpb (on the right control without agent and on the left with alum 1000 ppm). figure 4: carbohydrate fermentation test using (a) mannitol and (b) sorbitol. procedure: 1brain heart infusion broth was prepared and distributed in test tubes by 8.9 ml each (ph 7.0), sterilized by autoclave. 2one ml of the tested agent was added to both control and study groups. 30.1 ml inoculum was added to each broth of the study group giving the total volume for each test tube 10 ml of bhi broth plus tested agent plus bacterial inoculum. 4both study and control groups were incubated aerobically at 37ºc for 24 hours. 5the least concentration that lacks a visual turbidity matching the negative control (deionized water) was considered as the mic. 6the mbc was assessed, by inoculating 0.1 ml of the concentration assigned as mics on msb agar, then incubated anaerobically for 24 hours at 37ºc. the least concentration that inhibited growth of mutans streptococci on msb agar was considered as mbc. sensitivities of mutans streptococci to different concentration of alum mouthrinses: agar well technique was applied to study the antibacterial effect of different concentrations of alum (50, 100, 250, 500, 1000, 2000, 5000, 10000 ppm) compared with chlorhexidine (0.1% and 0.2%) and deionized water as control on mueller hinton agar media. the experiment was conducted on 11 isolates of mutans streptococci. procedure: 1a volume of 25 ml of mha (ph 7.0) was poured into sterile petri dish, left at room temperature for 24 hours. 2to each plate 0.1 ml of mutans streptococci inoculum was spread, left at room temperature for 20 minutes. 3four wells of equal size and depth were prepared in each agar plate. each well was filled with 0.1 ml of the test agent (alum, chlorhexidine and deionized water). 4plates were left at room temperature for one hour then incubated anaerobically for 24 hours at 37ºc. zones of inhibition were measured across the diameter of each well. no zone indicated a complete resistance of bacteria to the tested agent (fig. 5). effects on viability counts of mutans streptococci: the viability counts of mutans streptococci inoculated from broth media, to which different concentrations of alum rinses were added, have been estimated in comparison to the control. the procedure was carried out on eleven isolates, eight from different concentration of alum mouthrinses (50, 100, 250, 500, 1000, 2000, 5000 and 10000 ppm), and two with chlorhexidine gluconate mouthrinse 0.1% and 0.2%, and deionized water as control. the followed method was in accordance to that described by baron et al. (26). figure 5: well agar technique. procedure: 1brain heart infusion broths were prepared (ph 7.0) and distributed in screwcapped bottles by 8.9 ml to each bottle. 2one ml of the test agent was added to each bottle. 3then 0.1 ml of bacterial inoculum was added to both study and control bottles. from the control tube, 0.1 ml was transferred to 0.9 ml of sterile pbs (ph 7.0) and a ten-fold dilution j bagh college dentistry vol. 25(special issue 1), june 2013 the effects of pedodontics, orthodontics and preventive dentistry150 was performed. from dilutions 10-3 and 10-5, 0.1 ml was taken and spread on duplicates of msb agar plates which were incubated anaerobically at 37ºc for 48 hours. this value was considered as the initial count of bacteria. 4study and control cultures were incubated aerobically at 37ºc for 24 hours. from the each tube, 0.1 ml was transferred to 0.9 ml of sterile pbs and a ten-fold dilution was performed. from dilutions 10-3 and 10-5, 0.1 ml was taken and spread on duplicates of msb agar plates which were incubated anaerobically at 37ºc for 24 hours. the colony-forming units per milliliter of innoculum was counted (cfu/ml) for all the plates. results sensitivity tests of ms: the results of the in vitro bacteriological tests revelaed that the mic of alum was 500 ppm whereas the mbc was 1000 ppm. the sensitivity of ms to the different concentrations of alum and chlorhexidine in comparison to control were performed by two tests. inhibition zone: the inhibition zone (mm) for the control and test agents are presented in table 1. the inhibition zone for alum increased with the increase of concentration of the solution starting from 0mm for 50 ppm to 5mm for 10000 ppm. while, chlorhexidine showed a considerably larger inhibition zone of 8mm for 0.1% concentration and 10mm for 0.2%. viability count of ms: the colonyforming units per millilitre of the inoculum for the control and test agents are presented in table 2 and figure 6. low alum concentrations were close to the count obtained for deionized water, while stronger concentrations approximated the readings for chlorhexidine. adherence test the results of the adherence test for the control and test agents are displayed in table 3. low alum concentrations (50, 100, 250, 500, 1000 and 2000 ppm) resembled the negative control (deionized water) in showing positive adherence of the ms to the tooth surface, while a stronger concentration of 5000 ppm resembled the action of 0.1% chlorhexidine in showing negative adherence at 2 minutes only. whereas, the strongest alum tested concentration of 10000 ppm resembled the action of 0.2% chlorhexidine in showing negative adherence at 1 and 2 minutes. discussion the inhibition zone increased with the increase of concentration of alum solution from 50 to 10000 ppm; while, chlorhexidine showed a considerably larger inhibition zone for 0.1% and 0.2% concentration. viability count of ms also decreased with higher alum concentration, with stronger concentrations approximating the readings for chlorhexidine, which agrees with mourughan and suryakanth (6). this indicates that alum has an antibacterial action somewhat weaker than that of chlorhexidine. this action increases with increased alum concentration which agrees with the findings of putt and kleber (12) who found that the protective effect of the 100 ppm alum solution was less than solutions containing 1000 ppm alum or more. therefore it was decided to use the alum concentration of 1000 ppm for the in vivo study as a mouth rinse as there was a scant difference between 1000 ppm and higher concentration regarding the inhibition zone and the ms viability count in agreement with putt and kleber (12). low alum concentrations showed positive adherence of the ms to the tooth surface, while stronger concentrations of 5000 and 10000 ppm resemble the action of 0.1% and 0.2% chlorhexidine in showing negative adherence, this was with agreement to the findings of bihani and damle (2) and olmez et al (8). this indicated that alum has a weak effect on the adherence of ms to the tooth surface. table 1: results of the inhibition zone (mm) for different test agents. agent chx d w alum (ppm) concent ration 0. 1% 0. 2% 50 10 0 25 0 50 0 10 00 20 00 50 00 10 00 0 inhibition zone (mm) 8 10 0 0 0 0 1 3 3 4 5 table 2: the viability count of ms in different media. agent chx d w alum (ppm) concentration 0. 1% 0. 2% 50 10 0 25 0 50 0 10 00 20 00 50 00 10 00 0 cfu ml x105 5 3 36 31 25 22 18 10 9 7 4 j bagh college dentistry vol. 25(special issue 1), june 2013 the effects of pedodontics, orthodontics and preventive dentistry151 0 5 10 15 20 25 30 35 40 0. 10 % 0. 20 % 50 10 0 25 0 50 0 10 00 20 00 50 00 10 00 0 chx dw alum (ppm) figure 6: the viability count (colonyforming units per millilitre) of ms (x105/ml) in different media. table 3: results of the adherence test for different test agents by time. agent chx d w alum (ppm) concentration 0. 1% 0. 2% 50 10 0 25 0 50 0 10 00 20 00 50 00 10 00 0 1 min + + + + + + + + + 2 min + + + + + + + + means presence of adherence means absence of adherence references 1. putt ms, kleber cj, smith ce. evaluation of an alumcontaining mouthrinse in children for plaque and gingivitis inhibition during 4 weeks of supervised use. pediatr dent 1996; 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(eds) textbook of clinical cariology. 2nd ed. munksgaard. copenhagen. 1994: 17-43. 21. edwardsson s. the caries-inducing property of variants of streptococcus mutans. odont rev 1970; 21: 154-7. 22. koneman e, allen s, janda w, scherekerger p. color plates and textbook of diagnostic microbiology. 4th ed. jb. lippincott co, philadelphia 1992. 23. nolte aw. oral microbiology with basic microbiology and immunology. 4th ed., mosby st. louis london. 1982; pp.304-17. 24. finegold s, baron e. methods for identification of etiologic agents of infectious disease. in: bailey and scotts diagnostic microbiology 7th ed. cv mosby co., st. louis. 1986: 382. 25. el-samarrai s. major and trace elements contents of permanent teeth and saliva, among a group of adolescents, in relation to dental caries, gingivitis and mutans streptococci (in vitro and in vivo study). ph.d. thesis, college of dentistry, university of baghdad, iraq, 2001. 26. baron e, peteson l, fingold s. methods for testing antimicrobial effectiveness. in: bailey and scotts diagnostic microbiology. 9th ed. cv mosby co, st. louis, 1994. dropbox 5 taghreed f 25-31.pdf simplify your life j bagh college dentistry vol. 30(4), december 2018 early impact of 1 early impact of fixed orthodontic therapy on gingival health status in relation to weight status zaid ali alasadi b.d.s. (1) alhan ahmed qasim b.d.s, m.sc. (2) abstract background: fixed orthodontic appliances deleterious influence on gingival health is well documented. association between weight status and gingival health is presented in many studies. this study aimed to evaluate how early the impact of fixed orthodontic therapy on patients` gingival health, and if there are differences of that impact among different weight status groups. materials and methods: sample consisted of 54 patients (25 males, 29 females; age limits are 16 -18 years) going under the course of treatment with fixed orthodontic appliance. patients were categorized according to their body mass index (bmi) into 3 weight status groups considering who charts in 2007 (underweight, normal weight, overweight and obese), then determination of each patient`s gingival health status was through the criteria of the gingival index (gi) by loe and silness in 1963 which modified by loe in 1967. records of gingival index for all patients who met specific criteria were taken in three time points [before bonding (1st visit), 2 weeks after bonding (2nd visit), and 4 weeks after bonding (3rd visit)]. also bmi of the patients were checked at each of the three visits. results: there was a significant increase in gingival index for all bmi weight status groups after just two weeks of treatment, and the increase continues during the 3rd visit, with no significant difference in impact among weight status groups. conclusions: oral health preventive measures should be applied rapidly and equally to all patients treated with fixed orthodontic appliances, without taking their bmi weight status in consideration. key words: early, fixed, orthodontic, gingival health, weight, bmi. (received: 12/8/2018; accepted: 16/9/2018) introduction fixed orthodontic appliances introduce an additional constituent to the oral cavity complex that may enhance oral environment in a variety of ways (1). on the other hand, orthodontic treatment leads to changes in the oral environmental factors that encourage deteriorations in oral hygiene status and increased plaque coverage in orthodontic patients to 2 or 3 folds than levels observed in high plaque forming subjects without appliance (2). elevation of plaque and calculus presence, and increased gingival inflammation are all factors supplement the risk of caries activity and periodontal health, and shake the stability of the oral environment (3). pain is considered one of the major factors that cause deterioration in gingival health status, due to difficulties in performing usual preventive measures (4) and changes in patients` dietary habits (5). pain and discomfort caused by fixed orthodontic appliance can last for 14 days (6). the world health organization (who) describes obesity as one of today’s most neglected public health problem, affecting every region of the globe (7). __________________________ (1) ministry of health, baghdad, iraq (2) b.d.s, m.sc., assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. well documented researches had established significant relationship between weight status and periodontal diseases (8, 9). gingivitis, the mildest form of periodontal disease, is a rapidly inducible and reversible inflammatory affection of the gingiva, mainly caused by accumulation of bacterial biofilm. the combination of bacterial infection and persistent inflammatory response can eventually induce the progressive destruction of the deeper periodontal tissues, a worse form of periodontal disease called periodontitis (3). gingivitis and periodontitis can be considered a continuum of the same inflammatory process, although it is important to note that gingivitis lesions do not necessarily progress to periodontitis (10). additional risk factors include genetic susceptibility, tobacco smoking, alcohol consumption, and systemic conditions such as diabetes, osteoporosis, malnutrition, and overweight and obesity can facilitate the progression of gingivitis into periodontitis (11-13). since there is a well known effect of fixed orthodontic appliance on gingival health that is mainly provoked by pain. and previous studies findings that correlate periodontal problems to malnourishment and obesity. the hypothesis of the present study is that there will be an early impact of fixed orthodontic appliance on gingival health, and this impact will be of different effect on different weight status groups. literature had showed only one study concerning differences of effects of fixed orthodontic treatment on gingival j bagh college dentistry vol. 30(4), december 2018 early impact of 2 health status on patients with different bmi weight statuses, which is a study by von bremen et al (14) materials and methods study group this was an observational, prospective, selfcontrolled study. the study group consisted of patients about to be orthodontically treated with fixed appliances in the department of orthodontics inside the specialized dental center for prosthodontics and orthodontics in babalmoadham in baghdad/iraq. the inclusion criteria was only to be within the age limits, while the exclusion criteria were: (1) subjects with any systemic or oral diseases or any kind of allergies (2) subjects undergone orthodontic treatment before (3) subjects with congenital craniofacial anomalies (4) subjects with any oral or general pain (5) subjects who had been; or willing to be on a diet (include fasting) (6) subjects require the usage of space gaining appliance during their treatment (7) subjects receiving any medications (8) subjects with any kind of addiction (include all types of smoking) (9) uncooperative patients who didn’t commit to the previous criteria during the study period, or miss appointments in ±1 day. since the present study is a follow up study, in order to minimize the effects of different known and unknown variables, subjects before wearing orthodontic appliances were used as a study control. informed consent was obtained from all participants and their parents after a detailed explanation of the study. approval of the study protocol was obtained by the scientific committee of the pediatric and prevention department/collage of dentistry/university of baghdad. due to the dental center policy, all patients must receive a full dental treatment, plus a complete scaling and polishing treatment and oral hygiene instructions, maximally 2 days prior starting the bonding of orthodontic fixed appliance. all patients were orthodontically treated using the same equipments [stainless steel arch wire (world class tech. /ortho classic / usa), stainless steel brackets (stratus / fairfield / usa), bonding agent, (resilience / ortho technology / usa), stainless steel bands (world class tech. /ortho classic / usa), luting glass ionomer cement (riva luting /sdi /ireland), ligature rings (world class tech./ortho classic / usa)]. at the beginning of each of the three visits; a data sheet were filled for each subject; including records of height and weight taken for each patient in order to calculate their body mass index (bmi) (15), next, according to the results of those calculations, patients were grouped under three categories (underweight, normal weight, overweight and obese), considering a standerd charts set by world health organization (who); specific for each age (in months) and gender (16). the final number of patients in each category was (underweight group=16, normal weight group= 25, overweight and obese group=13) oral examination clinical examination and oral hygiene assessment have been done on dental chairs of the orthodontic department of the specialized dental center of bab-almuadham, fallowing standardized conditions of the basic methods of oral health surveys set by who in 1997 (17). a complete oral examination to all aspects and surfaces of soft and hard tissues was done for each participant, and all observations were recorded on each patient`s case sheet. the assessment of gingival health of the patients was done through examining four aspects (facial, lingual or palatal, mesial, distal) of all teeth according to the criteria of the gingival index (gi), which was set by loe and silness (18), and modified later by loe(19). statistical analysis residuals are tested with the use of shapiro-wilk test of normality after applying it to the whole sample, and all appeared to be normally distributed. general linear model (glm) for repeated measures was used to determine the different readings of the variables included in the study for the same subject in different time intervals for both (within-subjects factors and between-subjects factors), also using of bonferroni because of having three levels in the study structure, so univariate tests were illustrated to show the within-subjects effects, while pairwise t-test comparisons were used in estimation of means difference between each two visits. one-way anova was used in order to compare between the three categories that the sample was divided into, in order to test significance of the relations between them. the level of significance was set at 0.05. statistical analyses were performed with the use of (statistical package for social science spss version 21), results the distribution (in numbers and percentages) of the sum of study participants inside each bmi j bagh college dentistry vol. 30(4), december 2018 early impact of 3 weight status group in the three visits is shown in table 1. the table reveals that the sum and percentage of patients inside each group did not had any change during the three visits, while table 2 shows that changes in patients' body mass index (bmi) through the three visits were not significant. table 3 shows descriptive and statistical test of gingival index changes through visits and by weight status. the table shows under the column of "general liner model (glm) of repeated measures" that there was significant change through the three visits for all weight status groups. under the column "pairwise t-test" comparing between each two visits, which shows that there was a significant increase in the 2nd visit for all weight status groups, and the increase continues in the 3rd visit. comparing the readings of the three weight status groups in each visit had been showed in the raw "anova", the results in it shows no significant difference among weight status groups at each visit. table 1: distribution (in numbers and percentages) of the study subjects weight status through the three visits table 2: descriptive and statistical test of changes of means of bmi of each weight status group between visits by gender bmi weight status gender 1st visit 2nd visit 3rd visit anova mean ±sd mean ±sd mean ±sd f sig underweight male 18.34 0.26 18.14 0.28 18.27 0.13 0.860 0.439 female 17.17 1.49 17.05 1.47 17.15 1.50 1.002 0.381 normal weight male 21.14 1.76 21.01 1.72 21.22 1.64 2.521 0.110 female 19.90 2.27 19.74 2.32 19.79 2.35 0.775 0.473 overweight and obese male 30.82 4.33 30.48 4.01 30.02 3.28 2.668 0.150 female 27.54 5.04 27.36 4.64 27.54 5.36 0.050 0.880 table 3: descriptive and statistical test of gingival index changes through visits and by weight status. weight status 1st visit 2nd visit 3rd visit glm for repeated measures pairwise t-test m ±sd m ±sd m ±sd f p visits p underweight 0.06 0.06 0.19 0.18 0.28 0.23 11.950 0.000* 1st x 2nd 0.012* 1st x 3rd 0.002* 2nd x 3rd 0.159 normal weight 0.04 0.05 0.21 0.21 0.36 0.33 19.353 0.000* 1st x 2nd 0.000* 1st x 3rd 0.000* 2nd x 3rd 0.017* overweight & obese 0.08 0.10 0.25 0.27 0.44 0.43 9.767 0.002* 1st x 2nd 0.037* 1st x 3rd 0.010* 2nd x 3rd 0.128 f 1.621 0.359 0.847 p 0.208 0.700 0.435 *significant (p< 0.05) bmi weight status 1st visit 2nd visit 3rd visit sum % sum % sum % underweight 16 29.6% 16 29.6% 16 29.6% normal weight 25 46.3% 25 46.3% 25 46.3% overweight and obese 13 24.1% 13 24.1% 13 24.1% total sum of samples 54 100% 54 100% 54 100% j bagh college dentistry vol. 30(4), december 2018 early impact of 4 discussion the present study had the closest design to von bremen et al study (14), but still had few differences from it. its study samples were categorized according to their body mass index into three categories (normal weight, overweight, and obese), also, records had been taken in only two visits (before bonding and after debonding of fixed orthodontic appliance), that is because von bremen study was retrospective, depending on previously recorded data and photographs in scoring gingival index. the von bremen study has some advantages over the present study, like larger number of the study subjects (181 patients). the von bremen et al study had found that there was a significant increase in gingivitis of obese patients than normal and overweight ones. this finding may be considered consecutive with the present study findings, since in this study in overweight and obese group there were only 4 obese patients of 13, while the rest were just overweight subjects, so the readings of overweight subjects were more influential on the group values than obese subjects. the result of the present study showed no significant difference between weight status groups, this may be referred to four hypothetical reasons: [1] the duration of the study was not long enough to reveal differences among weight status groups, because gingival inflammation is directly related to the duration of treatment (20). [2] the differences in bmi were not enough to provoke any differences on gingival health status, or in other words, weight differences are not effective yet to produce bad effects on gingival health /or deteriorate an already found ones. this can be noticed in von bremen et al study (19), when overweight group showed no significant difference while obese group showed significant increase in gingival index. [3] the effect of fixed orthodontic appliance was uniform in affecting all study subjects. pain had a great contribution on changing dietary behavior of patients, and had a direct effect on physical properties of diet consumed by patients, since patients prefer softer food types and avoid harder ones (5). that change in food preferences may cause a decrease in chewing behavior, which can cause an elevation in gingival inflammation (21). another effect of pain and discomfort from using fixed orthodontic appliance is when practicing everyday oral preventive routine. oral hygiene practice had the upper hand in controlling plaque and gingival health (22). although of different patients` attitude toward oral hygiene practice, but the design of the study eliminates these differences since it is a self-controlled study, so it measures changes on study subjects rather than differences between study subjects and controls. [4] results of the present study may be included with other results of future studies that support no significant differences on gingival health among adolescent subjects with different bmi after ongoing under the course of fixed orthodontic treatment. the age of the patients may had an influence that provide higher immunological characteristics, which can compensate of the damaging effects of bacterial plaque on gingival health in spite of bad influence of thinness or obesity (23). each one of the previous four hypotheses needs more investigation to be proven, also each one needs to be edited and modified. also new theories may be added when extensive researches about the same subject of this study are redone. the present study considered different than other studies because of categorizing early effect of fixed orthodontic treatment according to weight status of the patients on gingival health. also what increase its individuality is it checks with patients after 2 weeks and then after 4 week from the first visit, which is very important to determine the true impact of orthodontic appliance away from patients` adaptation to pain and discomfort, which maximally recorded after 14 days (6). result of the present study revealed that there was an increasing in gingival index, a result that many researchers are in accordance with, especially within the period of four weeks or a month (20, 24, 25). the present study revealed a significant elevation in gingival index at the 2nd visit. sudden impact of pain through the first period which led to a change in the form of the food to a softer and less fibrous composition (5), less chewable diet leading to increased gingival inflammation (21). addition of numerous components of fixed orthodontic appliance (brackets and auxiliaries) that increase the difficulty of the conventional oral hygiene practices (26), which led to rapid and effective plaque formation. plaque bacteria which considered the main factor in increasing gingival inflammation(3), beside the traumatic action of the fixed orthodontic appliance components, like bands impinge on gingiva and over extended luting material over the gingiva (27). the results showed that after the significant increase in gingival index on the 2nd visit for all weight status groups there was a non significant increase for the underweight and overweight group, but kept its significant increase for normal weight status group. this may be related to the continuous exaggeration and consistent focusing of the immune system on the impact of fixed orthodontic appliance of normal weight group j bagh college dentistry vol. 30(4), december 2018 early impact of 5 more than underweight and overweight groups (28). conclusions there was a significant early impact of fixed orthodontic treatment on gingival health status; but there was no significant difference of that impact among weight status groups. oral health preventive measures should be applied instantly and equally to all patients under fixed orthodontic treatment without taking their weight status in consideration. acknowlegment the authors would like to give deep appreciation, gratitude, and gratefulness to the administration, dentists and orthodontists, medical staff, and all workers inside the specialized prosthodontics and orthodontic dental center in bab-almoatham /baghdad /iraq, for their contribution of the success of this study. references 1. mitchell l. an introduction to orthodontics. 4th ed. united kingdom: oxford university press; 2013. 2. klukowska m, bader a, erbe c, bellamy p, white dj, anastasia mk, wehrbein h. plaque levels of patients with fixed orthodontic appliances measured by digital plaque image analysis. am j orthod dentofacial orthop. 2011; 139: 463-470 3. marsh p, lewis m, rogers h, williams d, wilson m. marsh and martin`s oral microbiology. 6th ed. united kingdom: churchill livingstone; 2017. 4. shanbhog r, raju v, nandlal b. correlation of oral health status of socially handicapped children with their oral heath knowledge, attitude, and practices from india. j nat sc biol med. 2014; 5(1):101-107. 5. al jawad fa. an investigation of the early effects of fixed orthodontic treatment on dietary intake and body weight in adolescent patients. united kingdom, queen mary’s school of medicine and dentistry/ university of london, phd thesis dissertation; 2011. 6. brown, d, moerenhout, r. the pain experience and psychological adjustments to orthodontic treatment of preadolescents, adolescents and adults. am j orthod dentofacial orthop.1991; 100: 349-356. 7. kalra s, unni krishnan ag. obesity in india: the weight of the nation. j med nutr nutraceut. 2012; 1:37-41. 8. deshpande nc, amrutiya mr. obesity and oral health is there a link? an observational study. j indian soc periodontol. 2017; 21(3):229-233. 9. al-zahrani ms, bissada nf, borawskit ea. obesity and periodontal disease in young, middle-aged, and older adults. j periodontol. 2003; 74:610–5. 10. scapoli l, girardi a, palmieri a, martinelli m, cura f, lauritano d, carinci f. qualitative analysis of periodontal pathogens in periodontitis and gingivitis. j biol regul homeost agents. 2015; 29(3): 101-110. 11. pihlstrom bl, michalowicz bs, johnson nw. periodontal diseases. lancet 2005; 366(9499):1809-20. 12. heitz-mayfield lj. disease progression: identification of highrisk groups and individuals for periodontitis. j clin periodontol 2005; 32 (6):196-209. 13. keller a, rohde j f, raymond k, heitmann b l. association between periodontal disease and overweight and obesity: a systematic review. j periodontol. 2015, 86: 766-776. 14. von bremen j, lorenz n, ruf s. impact of body mass index on oral health during orthodontic treatment: an explorative pilot study. eur j orthod. 2016; 38: 386–392. 15. world health organization. who expert consultation. appropriate body mass index for asian population and its implication for policy and intervention strategies. lancet. 2004; 363:157-163. 16. de onis m, onyango aw, borghi e, siyam a, nishida c, siekmann j. development of a who growth reference for school-aged children and adolescents. bull world health organ. 2007; 85: 649-732. 17. who. oral health surveys` basic methods. 4th ed. world health organization. geneva, switzerland. 1997. 18. loe h, silness j. periodontal disease in pregnancy. acta odontol scand. 1963; 21: 533-51. 19. loe, h. the gingival index, the plaque index system. j periodontol. 1967; 38: 610-16. 20. alidan e, alrawi n. oral health status among patients treated with fixed orthodontic appliance at different time intervals. mustaniriya dent j. 2016; 13: 31-37. 21. doi t, hinode d, nakae h, yoshioka m, matsuyama m, iga h, fukushima y. relationship between chewing behavior and oral conditions in elementary school children based on the“chewing 30” program: an intervention study. j dent hlth. 2016; 66: 438–444. 22. sreenlvasan p k, prasad k v v, javali b s. oral health practice and prevalence of dental plaque and gingivitis among indian adults. clin exp dent res. 2016; 2(1): 6-17. 23. cole mf, hsu sd, baum bj, et al. specific and nonspecific immune factors in dental plaque fluid and saliva from young and old populations. infect immun. 1981; 31(3): 998-1002. 24. naranjo aa, trivino ml, jaramillo a, betancourth m, botero je. changes in the subgingival microbiota and periodontal parameters before and 3 months after bracket placement. am j orthod dentofacial orthop. 2006; 130: 17-22. 25. lara-carrillo e, montiel-bastida nm, snchez-pérez l, alans-tavira j. changes in the oral environment during four stages of orthodontic treatment. korean j orthod. 2010; 40: 95-105. 26. mount gj, hume wr. preservation and restoration of tooth structure. 2nd ed. queensland: knowledge books and software; 2005. tel:2015 tel:766-776 http://www.who.int/bulletin/en/ http://www.who.int/bulletin/volumes/85/9/en/ http://www.who.int/bulletin/volumes/85/9/en/ j bagh college dentistry vol. 30(4), december 2018 early impact of 6 27. kassab m m, cohend e r. the etiology and prevalence of gingival recession. j am dent assoc. 2003; 134(2): 220-225. 28. niemanl dc, nehlsen-cannarellaz sl, henson da, butterworth de, fagoagaz or, warren bj, mk rainwater. immune response to obesity and moderate weight loss. int j obes. 1996; 20: 353-360. http://m.kassabd/ http://e.cohend/ tel:134 tel:220-225 j bagh college dentistry vol. 30(4), december 2018 early impact of 7 المستخلص لتقييم كم من المبكر يبدا . هدفت هذه الدراسه وصحه اللثه قدمت في العديد من الدراسات العالقه بين حاله الوزن يد, موثق بشكل ج صحه اللثهالتاثير السلبي لجهاز التقويم الثابت على . على المرضى باختالف فئاتهم الوزنيه هذا التاثيرتاثير جهاز التقويم الثابت على صحه لثه المرضى, و بيان ان كان هنالك اختالف في عام(ماضين للبدء بالعالج بجهاز التقويم الثابت. قسمت العينه حسب مؤشر كتله 18و 16انثى بعمر بين 29ذكر و 25مريضا ) 54المواد و االساليب : تكونت عينه الدراسه من لكل مريض من خالل بعدها تم تحديد حاله صحه اللثه .فض الوزن , معتدل الوزن , مرتفع الوزن و بدين(منخ ) 2007حسب جداول منظمه الصحه العالميه الجسم الى ثالث مجاميع ولكل {(3(, بعد اربع اسابيع من التثبيت)زياره 2(, بعد اسبوعين من التثبيت )زياره 1قبل تثبيت جهاز التقويم)زياره }فحص الفم و تسجيل القراءات على مدى ثالث فترات زمنيه كذلك تم قياس مؤشر كتله الجسم خالل الزيارات الثالثه تباعا.(.giاللثه ) حاله من خالل استخدام مؤشر . تم تقييم صحه اللثه وافقوا المعايير الخاصهمرضى اللذين ال ولكن و استمر االرتفاع في مؤشر صحه اللثه خالل الزياره الثالثه,الزياره الثانيه , اسبوعين ضمن خاللو ;ولكل الفئات الوزنيه اللثه صحه حالهلارتفاعا داال احصائيا :اظهرت النتائج .الوزنيه بين تلك الفئاتمن دون فروقات داله احصائيا و مبكر ,بشكل جدي ايه صحه الفم ,و بشكل مرتفع و سريع . لذا يجب ان تطبق وسائل وق الثابت يؤدي الى تراجع جدي بصحه اللثه م العالج باستخدام جهاز التقوي االستنتاج : المرضى بغض النظر عن اوزانهم .لكل متساوي basima.doc j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 133 quantitative detection and correlation of epstein barr virus in plasma with gingivitis and severity of chronic periodontitis by using real-time polymerase chain reaction technique nada k. imran, b.d.s. (1) basima gh. ali, b.d.s, m.sc. (2) duraid q. jassim, m.b.ch.b., f.i.b.m.s. (3) abstract background: this study aimed to detect ebv quantitatively in plasma using real-time polymerase chain reaction technique in chronic periodontitis and gingivitis patients and to compare the finding with control subjects (healthy periodontium) and to investigate the relationship between the presence of ebv & the severity of periodontal diseases using the clinical periodontal parameters (pli ,gi , bop ,ppd and cal) between each of (chronic periodontitis and gingivitis) patients and compare with control (healthy periodontium) subjects . materials and methods: the study sample consisted of (101) individual of both genders, (61) chronic periodontitis patients which were subdivided into (mild, moderate & severe) depending on the scores of clinical attachment level, (20) gingivitis patients and (20) control subjects (healthy periodontium) with age ranged from (30-50) years. all the groups were without any history of systemic diseases. clinical periodontal parameters used in this study were (pli ,gi , bop ,ppd and cal) .blood samples were collected from all individuals and examined by real-time pcr technique for the detection of ebv. results: the result of comparison for the occurrence of ebv among study and control groups according to sequential responding of ebv appears to be highly significant at negative level of ebv, significant in (100 500 copy/105 cells) level and the results of leftover levels appear non significant difference. the result of correlation between the actual occurrence of ebv and ppd scores in severe chronic periodontitis subgroup appears to be significant at ppd score (1) and non significant at scores (2&3). the correlations between ebv and ppd scores in moderate and mild chronic periodontitis subgroups appear to be non significant with all scores. the results of correlation between ebv and cal parameter appear to be non significant among all scores of chronic periodontitis subgroup. concerning plaque index, the correlation appears to be significant in mild chronic periodonttis subgroup and highly significant in control group. in case of gingival index, the correlation appears to be significant in severe chronic periodontitis subgroup and control group .the result of correlation with (b.o.p. score 1) appears to be highly significant in severe subgroup of chronic periodontitis group and significant in gingivitis group, while in case of (b.o.p. score 0), the correlation appears to be significant only in severe chronic periodonttis subgroup. conclusions: the present findings revealed that there may be an association between ebv infection and the severity of periodontal diseases and thus coinfection with ebv may play a role in increase destruction of periodontal tissues. keyword: chronic periodontitis, ebv, real-time pcr. (j bagh coll dentistry 2014; 26(4):133-140). introduction periodontal diseases (pd) are group of inflammatory diseases caused by pathogenic microflora organized in biofilms surrounding the teeth (1). the causes of infection may include bacterial plaque and herpes virus (2,3) . there are two major types of periodontal disease: gingivitis and periodontitis. gingivitis involves a limited inflammation of the unattached gingiva and is a relatively common and reversible condition. in contrast, periodontitis is characterized by general inflammation of the periodontal tissues, which leads to the apical migration of the junctional epithelium along the root surface and progressive destruction of the periodontal ligament and the alveolar bone (4). (1) master student, department of periodontics, college of dentistry, baghdad university. (2) assistant professor, department of periodontics, college of dentistry, baghdad university. (3) assistant professor, baghdad medical city, ministry of health. bacterial infection alone may not explain the conversion of gingivitis to periodontitis(5) ,rapid tissue destruction around teeth exhibiting little plaque, the propensity of periodontitis to proceed with periods of exacerbation, remission and the tendency of periodontal tissue breakdown to advance in a localized and bilaterally symmetrical pattern (6) . however, it has been difficult to unravel the precise role of various putative pathogens and host responses in the pathogenesis of periodontitis. recent finding have showed herpes viruses especially epstein-barr virus (ebv) can infect or alter structural cells and host defense cells of the periodontium (7). it’s obvious that others factors beyond biofilm are important in the pathogenesis of periodontitis like tobacco smoking and genetically determined variations in inflammatory response patterns and recently, it was suggested that certain viruses might also influence the development and severity of periodontal diseases, though the cause of gingivitis and periodontitis is j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 134 credited to bacteria colonizing tooth surfaces and initiating the major mechanisms of periodontal destruction (8). viruses can also interfere on immune responses though immune modulators encoded within viral genomes, which include proteins that regulate antigen presentation, function as cytokines or cytokine antagonists, inhibit apoptosis and interrupt the complement cascade (9). viral infections may facilitate the destruction of periodontal tissue by lytic activity against periodontal cells, immune mediated tissue destruction and immune suppression, which increase the susceptibility of the host to bacterial attacks (10,11) .thus, a situation of viral-bacterial interaction could occur in the oral cavity without a denial of the argument for a major etiological role of bacteria in human periodontal disease. human cytomegalovirus (hcmv) and ebv-1 assume a particularly close relationship with human periodontitis while herpes simplex virus (hsv) , human herpesvirus-6 (hhv-6) and epstein-barr virus type-2 seem to exhibit little or no association with most types of periodontitis disease (12) . various systems for the detection of oral pathogens have been reported, but most are qualitative (13,14). because periodontal pathogens exist not only in infected pockets but also in the healthy sulcus, qualitative detection is not suitable for the diagnosis of periodontitis. for this purpose, the present study used a quantitative detection system that uses real-time polymerase chain reaction (real-time pcr) methodology. materials and methods human sample the sample in this study consisted of onehundred & one subjects with an age ranged from (30-50) years, males (73) & females (28), sample collection was started at 16th february 2013 till 20 march 2013. patients participating in the present study with chronic periodontitis (no=61), which were subdivided according to the severity of disease into (mild, moderate & severe) depending on the scores of clinical attachment level, gingivitis patients (no.=20) with limited inflammation of the gingiva , no probing pocket depth & no clinical attachment loss and control subjects (healthy periodontium) (no.=20) where there was no signs of periodontal disease with clinically healthy gingiva, no pockets, no bleeding on probing and no evidence of bone loss. the sample collected from patients recruited from the clinic of the department of periodontics/ college of dentistry/ baghdad university. clinical examination periodontal examination consisted of plaque index (pli) (15) ,gingival index (gi) (16), bleeding on probing (bop) (17), probing pocket depth (ppd) and finally clinical attachment level (cal) (18) measured at 4 sites for all teeth except 3rd molar on (mesial, vestibular, distal, lingual) using a calibrated periodontal probe (michigan o probe). patients with chronic periodontitis had periodontal pockets equal or greater than 3mm with clinical attachment loss (19). all subjects participated in this study without any systemic diseases, had not received previous periodontal treatment and had not used antibiotics in the past 3 months. patients were excluded if pregnant, smokers, menapaused women, female under contraceptive pills and patients with history of herpetic infection (self-reported) during the last six months. in the present study the laboratory results will be divided into 5 levels according to the quantity of ebv with cutoff point will be (100-500 copy/105 cell) level, these levels are: 1. negative level (score-1). 2. % <100 copy/105 cells level (score-2). 3. 100-500 copy/105 cells level (cutoff point) (score-3). 4. 600-1000 copy/105 cells level (score-4). 5. % >1000 copy/105 cells level (score-5). collection of blood sample and plasma preparation the blood was collected from all participants between (9 am-12 pm), the blood samples were taking from their arms from cubital fossa (cubital vien) , 5cc of venous blood taken from patients & control healthy individual and put it in [ethylen diamine tetra acetic acid (edta)] tubes as anticoagulant tubes used to preserve collected blood samples and then preserved in a cool box containing ice packs until transferring the samples to the laboratory. plasma separated from blood samples using centrifuge at speed (1600 r/min) for 20 min according to dna extraction kit manuals, then plasma samples preserved immediately into other plain tubes and stored in freeze at (15 cº ) until they were assayed. this was done within 4 hours after sample collection. dna extraction the kit used is dna column extraction kit {sacace-italy (lot number 1306/001)}, for extraction of dna using column method and j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 135 samples preserved in freeze thawed in room temperature for extraction. eppendorf tubes used in first step of extraction prepared & numbered according to the samples and then ribovirus columns used. after a long series of adding washing solutions, centrifuge and heating, we can get the pure dna captured at the bottom of each eppendorf tube. real-time pcr amplification the kit used is ebvreal time pcr kit from {sacace biotechnology (italy) (lot number 23k13k705)}, which contains (polymerase, mastermix, controls for quantitation, internal control). smart cycler pcr tubes used that numbered according to the samples, then 12.5 µl of extracted dna and pcr mix (which contain taq. polymerase enzyme ) added to each tube and each tube closed well & centrifuged in minispin centrifuge at (8000 r/min) for 20 seconds ,then tubes put in real-time pcr for amplification , we notice that internal control dna appears in fam fluorescent signal on pcr ,while dna samples appear in cy3 fluorescent signal channel on pcr. quantitation based on formulation of the kit and the results appear as curves of different colors on the monitor of real-time pcr system and the quantitation depends on standard curve. results the goodness-of-fit test ,which tests the mean value of the studied parameters {pli & gi, bop (score 1) and the sequential responding}, which was used to determine the normal and non normal distribution of the data , this test reflects that the results of (mean and standard deviation) for the study group was higher than that of control group as seen in table (1). the descriptive statistics of the clinical periodontal parameters reflect that the results of the study group were higher than that of the control group. according to sequential responding parameter, we notice that the mean values of positive records increase with increase severity of periodontal diseases & ebv levels at different groups and subgroups recorded, the higher mean was at severe subgroup of chronic periodontitis (3.77), while the least appears at control group (1.55) as seen in table (2). by using (lsd test ) ,this test revealed highly significant differences between severe subgroup & other groups and subgroups of the study according to sequential responding and significant difference between moderate subgroup of chronic periodontitis group & control group, while the leftover revealed non significant differences as seen in table (3). the result of comparison between the groups of the study & the levels of ebv appears to be highly significant at the negative level of ebv, non significant positive difference at the (%<100 copies/105 cells), significant positive difference at (100-500 copies/105 cells), non significant positive difference at the (600-1000 copies/105 cells) & non significant positive difference at the (% >1000 copies/105 cells). the result of comparison between the 3 groups of the study and ebv at the cutoff point (100-500 copies/105 cells) level appears to be statistically significant as seen in table (4). spearman's correlation coefficient. test, that is used for testing the correlation between different periodontitis subgroups & the clinical periodontal parameters {plaque index, gingival index & bop (score 0& 1)} according to sequential responding of ebv. in case of plaque index, a negative significant correlation appears in mild chronic periodontitis subgroup, while it appears non significant in case of (moderate and severe) chronic periodontitis subgroups. a negative significant correlation appears in case of gingival index in severe chronic periodontitis subgroup, while it is non-significant in (mild and moderate) chronic periodontitis subgroups. in case of bop score 1, the correlation appears to be highly significant and negative in severe subgroup of chronic periodontitis group and non significant in (mild and moderate) subgroups. the correlation of bop score 0 appears to be significant & positive in severe chronic periodontitis subgroup , while it appears non significant in case of (mild and moderate) subgroups of chronic periodontitis group as seen in table (5) . the correlation of ebv & { pli, gi, and bop (score 0&1)} in gingivitis group, which appears non significant, while the correlation of ebv & bop score (1) appears to be significant and negative as seen in table (6). the correlation of ebv & clinical periodontal parameters{ pli, gi, and bop (score 0&1)} in control group appears to be highly significant and negative (strong correlation) with plaque index, negative significant correlation with gingival index , while it appears non significant in case of bop score (0 &1) as seen in table (7). the correlation of ebv & ppd scores in severe periodontitis subgroup appears to be significant and negative at ppd score (1), while it appears a non significant correlation at ppd score (2&3). the correlation of ebv & all cal scores j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 136 appears to be non-significant and negative as seen in table (8). the correlation of ebv and (ppd & cal) scores in moderate periodontitis subgroup appears to be non significant with all scores of (ppd & cal) parameters as seen in table (9). the correlation of ebv and (ppd & cal) scores in mild periodontitis subgroup appears to be non significant with all scores of (ppd&cal) parameters as seen in table (10). table 1: goodness of fit test of normal distribution function for the studied parameters (pli, gi, bop score 0&1 and sequential responding) in study and control groups groups statistical information p la qu e in de x g in gi va l in de x b .o .p sc or e 1 se qu en ti al r es po nd in g study no. parameters 81 mean 1.506 1.452 61.69 2.280 ± sd 0.538 0.452 34.23 1.280 control no. parameters 20 mean 0.110 0.147 4.800 1.550 ± sd 0.057 0.164 2.840 0.690 table 2: summary statistics of (sequential responding) parameter at the different groups and subgroups parameter groups and subgroups no. mean ±std. dev. std. error sequential responding chronic periodontitis severe 13 3.77 0.73 0.2 chronic periodontitis moderate 23 2.26 1.01 0.21 chronic periodontitis mild 25 2.00 1.22 0.24 gingivitis 20 1.70 1.22 0.27 control 20 1.55 0.69 0.15 table 3: multiple comparisons (lsd) between all pairs of different groups and subgroups according to sequential responding parameter: dependent variable study groups & subgroups mean difference sig. c.s. sequential responding chronic periodontitis – severe chronic periodontitis –mod. 1.51 0.001** hs chronic periodontitis mild 1.77 0.001** hs gingivitis 2.07 0.001** hs control 2.22 0.001** hs chronic periodontitis moderate chronic periodontitis mild 0.26 0.383 ns gingivitis 0.56 0.078 ns control 0.71 0.026* s chronic periodontitis mild gingivitis 0.30 0.334 ns control 0.45 0.149 ns gingivitis control 0.15 0.646 ns (**) hs: highly sig. at p< 0.01; (*) s: sig. at p<0.05; ns: non sig. at p>0.05 j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 137 table 4: distribution of the absent & present responding at each group according to different levels of ebv with contingency coefficients levels resp. (+& -) no. & percents groups c.s. p-value c hr on ic p er io do nt it is g in gi vi ti s c on tr ol negative ( score -1) 0 no. 45 7 9 c.c.=0.32 5 p=0.003 (**) hs %negative 73.8% 11.5% 14.8% %groups 73.8% 35% 45% 1 no. 16 13 11 %negative 40% 32.5% 27.5% %groups 26.2% 65% 55% <100 copy/105 cells ( score -2) 0 no. 43 16 13 c.c.=0.10 6 p=0.564 ns %< 100 copy/10^5 cells 59.7% 22.2% 18.1% %groups 70.5% 80% 65% 1 no. 18 4 7 %< 100 copy/10^5 cells 62.1% 13.8% 24.1% %groups 29.5% 20.0% 35.0% 100 500 copy/105 cells ( score 3) 0 no. 47 20 18 c.c.=0.24 7 p=0.037 (*) s %100 500 copy/10^5 cells 55.30% 23.50% 21.20% %groups 77.00% 100.00 % 90.00% 1 no. 14 0 2 %100 500 copy/10^5 cells 87.50% 0.0% 12.50% %groups 23.00% 0.0% 10.00% 600 -1000 copy/105 cells ( score 4) 0 no. 53 18 20 c.c.=0.16 7 p=0.234 ns %500 -1000 copy/10^5 cells 58.20 % 19.80% 22.00% %groups 86.90% 90.00% 100.00 % 1 no. 8 2 0 %500 -1000 copy/10^5 cells 80.00 % 20.00% 0.0% %groups 13.10% 10.00% 0.0% >1000 copy/105 cells ( score 5) 0 no. 56 19 20 c.c.=0.13 4 p=0.306 ns %> 1000 copy/10^5 cells 58.90% 20.00% 21.10% %groups 91.80% 95.00% 100.00 % 1 no. 5 1 0 %> 1000 copy/10^5 cells 83.30% 16.70% 0.0% %groups 8.20% 5.00% 0.0% (**) hs: highly sign. at p<0.01; (*) s: sign. at p<0.05 ; ns: non sign. at p>0.05 c.c.: contingency coefficient j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 138 table 5: spearman's correlation coeff. for testing the correlation between sequential responding of ebv and (pli, gi, bop score 0 & bop score 1) parameters at each chronic periodontitis subgroups: clinical parameters spearman's corr. coeff. chronic periodontitis severe chronic periodontitis moderate chronic periodontitis mild plaque index corr. coeff. -0.217 -0.324 -0.387* p-value 0.477 0.132 0.05 no. 13 23 25 gingival index corr. coeff. -0.608* -0.256 -0.119 p-value 0.028 0.239 0.572 no. 13 23 25 b.o.p score 1 corr. coeff. -0.822** -0.253 -0.179 p-value 0.001 0.244 0.392 no. 13 23 25 b.o.p score 0 corr. coeff. 0.583* 0.26 0.179 p-value 0.036 0.231 0.392 no. 13 23 25 (**) hs: highly sign. at p<0.01; (*) s: sign. at p<0.05 ; ns: non sign. at p>0.05 table 6: correlation coefficients with their testing of null hypotheses between the actual of virus readings and the studied parameters ( pli, gi, bop score 0 & bop score 1) in gingivitis group group corr. and p-value plaque index gingival index b.o.p score 1 b.o.p score 0 gingivitis correlation -0.333 -0.293 -0.383 0.373 p-value 0.076 0.105 0.048 0.053 c.s. ns ns s ns table 7: correlation coefficients with their testing of null hypotheses between the actual of virus readings and the studied parameters ( pli, gi, bop score 0 & bop score 1) in control group group corr. and p-value plaque index gingival index b.o.p score 1 b.o.p score 0 control correlation -0.537 -0.476 -0.274 0.274 p-value 0.007 0.017 0.121 0.121 c.s. hs s ns ns table 8: correlation coefficients between the actual virus readings and the studied parameters (ppd and cal) scores in chronic periodontitis – severe subgroup: group corr. and p-value ppd score-1 ppd score-2 ppd score-3 cal score-1 cal score-2 cal score-3 chronic periodontitis –severe subgroup correlation -0.496 -0.175 0.214 -0.362 -0.263 -0.018 p-value 0.043 0.284 0.241 0.112 0.193 0.477 c.s. s ns ns ns ns ns table 9: correlation coefficients between the actual virus readings and the studied parameters in ch. periodontitis – moderate subgroup: group corr. and p-value ppd score-1 ppd score-2 ppd score-3 cal score-1 cal score-2 cal score-3 chronic periodontitis – moderate subgroup correlation -0.048 0.312 -0.105 0.102 0.03 0.303 p-value 0.414 0.074 0.317 0.321 0.445 0.08 c.s. ns ns ns ns ns ns table 10: correlation coefficients between the actual virus readings and the studied parameters in ch. periodontitis – mild subgroup: group corr. and p-value ppd score-1 ppd score-2 ppd score-3 cal score-1 cal score-2 cal score-3 chronic periodontitis –mild subgroup correlation 0.161 -0.150 0.049 0.052 -0.143 0.036 p-value 0.221 0.237 0.408 0.402 0.248 0.432 c.s. ns ns ns ns ns ns j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 139 discussion in this study a significant difference appears when comparison was made between 3 groups of the study and the percentage of ebv at the cutoff point of sequential responding parameter. this finding agree with wu et al (20) , where the higher level of ebv among study group compare to control group represent the role of these pathogens in destructive periodontal lesion where the virus effect on immune response of such patients. the pathogenic mechanisms of herpes viruses cooperate in exacerbating disease and probably for that reason, a periodontal dual infection with (hcmv and ebv) tends to occur in severe types of periodontitis (21) . a non significant negative correlation appears when correlation was made between the quantity of ebv and plaque index in case of {chronic periodontitis (severe & moderate) subgroups and in gingivitis group}, while there is a significant negative correlation in case of chronic periodontitis (mild subgroup) and a highly significant strong negative correlation appears in healthy control group. these findings appear to be disagree with saygun et al (22) where the difference in the measurements of plaque index in viral detected & undetected sites were statistically significant . when the correlation was made between the presence of ebv and gingival index, it's found that there is a non significant negative correlation in all groups and subgroups except in chronic periodontitis (severe subgroup) and healthy control group which showed a statistical significant negative correlation with the quantity of ebv. these findings are agree with the study done by charu (23) .the reasons of variation in ebv occurrence among studies may include differing ebv detection technique, dissimilar periodontal disease states studies and true geographic variation in ebv prevalence. a significant negative correlation was found between the presence of ebv and bleeding upon probing for (score 1) in chronic periodontitissevere subgroup and gingivitis group & a non significant correlation was found in case of bop score (0) with different groups and subgroups except chronic periodontitis-severe subgroup, which showed a significant strong positive correlation. these findings are disagree with maryam et al (24) , who found that there were no statistically significant differences in mean of bop among positive and negative patients for ebv-1, ebv-2 and hcmv ,where a higher mean of bop among patients who were infected with ebv-1 and hcmv did not reach to the level of statistical significance. the coinfection with ebv revealed bleeding upon probing, a clinical sign of elevated risk for disease progression (21) . the result of correlations between the three scores of periodontal pocket depth of chronic periodontitis subgroups & ebv quantity showed a significant correlation in case of severe chronic periodontitis subgroup at score (1), while there were non significant differences at scores (2&3), also non significant correlations were found in case of (moderate & mild) chronic periodontitis subgroups including all scores. these findings are disagree with ling (25), who found that the prevalence of virus in chronic periodontitis is very low (4%). these differences between studies could be due to differing in ebv detection technique, dissimilar in estimation of (ppd), but the present finding agrees with saygun et al and moghim et al (26,27). saygun et al observed that periodontal pocket depth was positively correlated with salivary ebv-dna counts. the results agree with wu et al (28) who found that a higher percentage of ebv associated with a deeper probing pocket depth. the prevalence of ebv-1 found in pd ≥ 6 mm was statistically greater than that in ppd ≤ 3 mm (24) . a study done by kubar et al (6) showed that a statistical significance difference was found between ebv subgingival counts and periodontal pocket depth at sample sites (spearman's correlation), where chronic periodontitis patients revealed more than 10,000 copies of (hcmv or ebv) in subgingival or gingival tissue samples (chi-square test. the interaction between ebv and p. gingivalis is bi-directional with p. gingivalis having the potential to induce ebv reactivation and ebv reactivation suppressing host defenses and permitting overgrowth of p. gingivalis which having the potential to induce periodontal tissue destruction (29) . a non significant correlation was found between the three scores of clinical attachment level (cal) of chronic periodontitis subgroups with the actual virus readings of ebv, this result disagree with wu et al (28), which found that a more serious attachment loss associated with the presence of ebv. a periodontal dual infection of ebv and pathogenic bacteria gives rise to enhanced cytokine release and immune signaling dysregulation and tends to be associated with more severe periodontitis than a periodontal infection involving solely bacteria (30-32). references 1. pihlstrom bl, michalowicz bs, johnson nw. periodontal diseases. lancet 2005; 366(9499):180920. 2. contreras a, slots j. herpes virus in human periodontal disease. j periodontal res 2000; 35:3-16. j bagh college dentistry vol. 26(4), december 2014 quantitative detection oral and maxillo-facial surgery and periodontics 140 3. surang t, penpan l, sroisiri t, varunee d, preeda w, sompoj c, potjamas p, pornsawan a, kruavan b, wasun c, panadda d. prevelence of cytomegalvirus, human herpesvirus-6 and epstein-barr virus in periodontitis patients and healthy subjects in the thai population. southeast asia j trop med puplic health 2004; (3593): 635-40. 4. pejčić a, peševska s, grigorov i, et al. periodontitis as a risk factor for general disorders. acta facult med naiss 2006; 23(1): 59-65. 5. slots j, sugar c, kamma jj. cytomegalovirus periodontal presence is associated with subgingival dialister pneumosintes and alveolar bone loss. oral microbiol immunol 2002; 17: 369-74 . 6. kubar a, saygun i, özdemir a, yapar m, slots j. real-time polymerase chain reaction quantification of human cytomegalovirus and epstein–barr virus in periodontal pockets and the adjacent gingiva of periodontitis lesions. j periodontal res 2005; 40: 97– 104. (ivsl). 7. contreras a, nowzari h, slots j. herpes viruses in periodontal pocket and gingival tissue specimens. oral microbiol immunol 2000; 15: 15-8. 8. cappuyns i, gugerli p, mombelli a. viruses in periodontal disease – a review. oral dis 2005; 11: 219-29. 9. spriggs mk. one step ahead of the game: viral immunomodulatory molecules. annu rev immunol 1996; 14:101-130. review. oral dis 2005; 11: 219-29. 10. banks t, rouse b. herpes viruses immuno escape artist. clin infect dis 1992; 14: 933-41. 11. taga h, taga k, wang f, chretien j, tosato g. human and viral interlukin-10 in acute epstein-barr virus induced infectious mononucleosis. j infect dis 1995; 171: 1347-50. 12. contreras a, umeda m, chen c, bakker i, morrison jl, slots j. relationship between herpes viruses and adult periodontitis and periodontopathic bacteria. j periodontol 1999; 70: 478–84. 13. yoshida a, nagashima s, ansai t, tachibana m, kato h, watari h, notomi t, takehara t. loopmediated isothermal amplification method for rapid detection of the periodontopathic bacteria porphyromonas gingivalis, tannerella forsythia, and treponema denticola. j clinical microbiol 2005a; 43(5): 241824. 14. yoshida a, tachibana m, ansai t, takehara t. multiplex polymerase chain reaction assay for simultaneous detection of black-pigmented prevotella species in oral specimens. oral microbiology and immunology 2005b; 20 (1): 43-6. 15. silness j, loe h. periodontal disease in pregnancy ii. corelation betweenoral hygiene and periodontal condition. acta odont scand 1964; 22: 121-35. 16. loe h. the gingival index, the plaque index and the retention index systems. j periodontal 1967; 38(6): 610-616. 17. newbrun e. indices to measure gingival bleeding. j periodontol 1996; 67: 555-61. 18. armitage gc. development of a classification system for periodontal diseases and conditions. ann periodontol 1999; 4(1):1-6. 19. eke pi, dye ba, wei l, thornton-evans go, genco rj. prevalence of periodontitis in adults in the united states: 2009 and 2010. j dent res 2012; 91(10): 91420. 20. wu ym, yan j, chen ll, sun wl, gu zy. infection frequency of epstein-barr virus in subgingival samples from patients with different periodontal status and its correlation with clinical parameters. j zhejiang univ sci b 2006; 7:876-83. 21. kamma jj, contreras a and slots j. herpes virus and periodontopathic bacteria in early-onset periodontitis. j clin periodontal 2001; 28: 879-85. 22. saygun i, sahin s, ozdemir a, kurtis b, yaper m, kubar a and ozcan g. detection of human viruses in patients with chronic periodontitis and the relationship between viruses and clinical parameter. j periodontal 2002; 73: 1437-43. 23. charu g. detection and assessment of human cytomegalovirus, eptein-bar virus-1 (ebv-1) and herpes simplex virus (hsv) in patients with chronic periodontitis of varying pocket depths. a thesis present to the faculty of gandhi university of health sciences for a degree of master science in periodontology, 2006. 24. maryam ch, sharareh m, ahamad m, farid n, faranak r. ebv and cmv in chronic periodontitis: a prevalence study. arch virol 2008; 153:1917–9. 25. ling lj, chuan-chen h, wu cy, et al. association between human herpes viruses and severity of periodontitis. j periodontol 2004; 75(11): 1479-85. 26. saygun i, kubar a, özdemir a, slots j. periodontitis lesions are a source of salivary cytomegalovirus and epstein-barr virus. j periodontal res 2005; 40(2):187191. (ivsl). 27. moghim sh, chalabi m, abed am, rezaei f, tamizifar h. prevalence of epstein-barr virus type 1 in patients with chronic periodontitis by nested-pcr. pak j biol sci 2007; 10: 4547-50. 28. wu ym, yan j, ojciu dm, chen ll, gu zy, pan jp. correlation between infections with different genotypes of human cytomegalovirus and epsteinbarr virus in subgingival samples and periodontal status of patients. j clin microbiol 2007; 45: 3665-70. (ivsl). 29. naoyuki s, kyoko i, maiko o, masataka i, hajime t, shuichi s, koichi i. relationship between porphyromonas gingivalis, epstein-barr virus infection and reactivation in periodontitis. j oral sci 2004; 46 (4): 203-6. 30. botero je, vidal c, contreras a, parra b. comparison of nested polymerase chain reaction (pcr), real-time pcr and viral culture for the detection of cytomegalovirus in subgingival samples. oral microbiol immunol 2008; 23: 239–44. 31. liu yc, lerner uh, teng yt. cytokine responses against periodontal infecton: protective and destructive roles. periodontal 2000 2010; 52: 163-206. 32. taylor jj. cytokine regulation of immune responses to porphromonas gingivalis. periodontal 2000 2010; 54: 160-4. j bagh college dentistry vol. 32(1), march 2020 the impact of dental 35 the impact of dental environment stress on caries experience, salivary flow rate and uric acid raghad ibrahim kadhum (1), alhan ahmed qasim (2) abstract background: several pathologies of the oral cavity have been associated with stress. dental students need to gain assorted proficiencies as theoretical knowledge, clinical proficiencies, and interpersonal dexterity which is accompanied with high level of stress. uric acid is the major antioxidant in saliva. the aim of this study is to assess the dental caries experience among dental students with different levels of dental environment stress in relation to physicochemical characteristics of whole unstimulated saliva. materials and methods: the total sample is composed of 300 dental students (73 males, 227 female) aged 22-23 years old, from collage of dentistry / university of baghdad, from the 4th and 5th grade. the total sample was classified into three categories (mild stress, moderate stress and severe stress) according to dental environment stress questionnaire (desq); diagnosis and recording of dental caries were assessed according to decay, missed, filled surface and teeth index (dmfs, dmft) of who criteria in 1987. unstimulated salivary samples were collected from the 95 dental students from the mild stress group (27 male, 28 female) and from the severe stress group (11 male, 29 female). then, salivary flow rate was measured and chemically analyzed to determine salivary uric acid concentration. all data were analyzed using statistical package for social science (spss) version 21. results: the mean value of the dmft and ds fraction was higher among severe stress group of dental environment stress scale with no significant differences (p≥ 0.05), while dmfs, fs and ms fractions were higher among moderate stress group of dental environment stress scale with no significant differences (p≥ 0.05). the data from salivary analysis showed that the mean value of salivary flow rate was lower among severe dental environment stress category than mild dental environment stress category but the difference was statistically not significant, while the mean value of uric acid was higher among students with severe dental environment stress than students with mild dental environment stress with statistically significant difference. the flow rate was negatively correlated with caries experience among both mild and severe stress groups except for the ds was positively correlated with flow rate among students with mild stress. the correlation of uric acid with dmft was negative among students with mild stress while among severe stress group was positive; however all these correlations were not statistically significant. conclusion: dental environment stress appears to affect oral health, shown by higher caries prevalence among dental students with moderate and severe dental environment stress level by affecting the normal level of salivary flow rate and uric acid. keywords: dental environment stress, stress, dental caries, flow rate, uric acid. (received: 15/12/2019; accepted: 23/1/2020) introduction most of the stress definitions emphasize stress as any factor that menaces the wellbeing of an individual or cause adverse effects on the body functions.(1) the central nervous system (cns) reacts to stress; this reaction involves different morphological and neurochemical alterations, among them, oxidative stress.(2) oxidative stress consists of an imbalance between the amounts of reactive oxygen species (ros) and the capability of antioxidant systems to equalize them.(3) stressors are known as the causes of stress, they could be emotional or physical, in addition, they could be internally or externally generated. (1) m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assist. professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. the stressors are categorized as: a) exogenous or outer stressors. b) endogenous or inner stressors. c) the formation of stress is also caused by the combination of exogenous and endogenous influences.(4) d) system induced stress is a kind of stress that is distinguished by psychologists. system is related to association such as schools, family, offices, and any other social structures, in which a person is dealt with.(5) dentistry is known as a very stressful occupation and dental education is involved as being a stressful education environment because the dental occupation demands interpersonal dexterity and clinical competencies as well as theoretical knowledge.(6) this stress can result in physical and psychological distress, which in turn can affect the health and performance of the student.(7-8) the main sources of stress among dental students include the education environment, apprehension of fail, hardness in dealing with patients, clinical requirements, hardness in dealing with transitions in curriculum and difficult relationships with academic staff.(9) j bagh college dentistry vol. 32(1), march 2020 the impact of dental 36 dental caries is a complex, chronic, multifactorial disease and one of the most prevalent diseases in industrialized and developing countries.(10) when the individual is exposed to stressful event, the psychological reaction to this event activates the sympathetic nervous system and the hypothalamicpituitary-adrenocortical (hpa) axis, causing the secretion of elevated amount of stress hormones, primarily cortisol and catecholamine, which causes decrease in salivary flow and in this manner changes salivary capability with regards to oxidation reduction.(11-12) the reduction in salivary flow decreases the defensive actions created by saliva and, as a result, raising the hazard for dental caries.(13-14) it was proposed that persons with psychological disturbance were more susceptible to bad caries state, which is because of a variety of causes such as selfnegligence.(15) the severity of the psychological stress diminishes in the capability to understand the complications of poor oral health, poor attention of oral hygiene, and illogical fear from dental therapy.(16-18) another study found that there is no relation between stress and salivary flow rate.(19-20) the major anti-oxidant of the saliva is the uric acid. the first defense mechanism against oxidative stress due to free radicals is the anti-oxidants present in the saliva.(21-23) the disequilibrium in concentrations of free radicals (reactive oxygen species) and antioxidants in saliva may have an important action in the initiation and progression of dental caries.(24) several studies found that the adherence capacity of some bacteria may be modulated via the antioxidant capacity of their environment.(25-26) therefore, the increase in the total antioxidant capacity (tac) of saliva could cause changes in the streptococcus adherence to the dental plaque, leading to maximal cariogenic action.(27) results of studies on the relation between uric acid concentration and caries experience were controversial. therefore the mean goal of this study was to determine the dental caries experience among different stress levels of dental students and to conduct an evaluation of its relation with salivary uric acid and flow rate. the null hypothesis was that there is no relation between salivary uric acid and flow rate with the development of dental caries experience among different stress levels of dental students. materials and methods the total sample is composed of 300 dental students (73 males, 227 female) aged 22-23 years old, from college of dentistry/ university of baghdad, from the 4th and 5th grad. dental environment stress was recorded for all dental students by means of selfrecorded questionnaire using dental environment stress questionnaire (desq).(28) this is a specific scale designed to measure the stress of dental students which consisted of (24) items, for each event 5 alternatives (very stressful, stressful, moderately stressful, not stressful, and not stressful at all), so the students have to answer for each event by choosing one of these alternatives. this questionnaire was adopted from other studies. the scale validity and reliability were checked. caries experience was diagnosed according to decay, missed, filled surface and teeth index dmfs/dmft of who.(29) for salivary analysis, a sub-sample of 95 students was taken. the collections of unstimulated saliva were performed under standard condition according to the university of southern california school of dentistry guidelines for saliva collection.(30) the collected saliva sample was poured directly after being collected in a graduated test tube to determine the volume collected through the 5 minutes period. the salivary flow rate was calculated by dividing the volume of collected saliva in milliliter (ml) by the time required for collection in minute (min), flow rate (ml/min) = volume (ml)/ time (min).(31) after the collection of saliva, each salivary sample was centrifuged (at 2000-3000 rpm) for approximately 20 minutes. salivary uric acid was determined colorimetrically by using the spectrophotometer and ready kit (agappe kit /switzerland). this method allows the determination of uric acid by reaction with uricase. uricase transforms uric acid into allantoin, with formation of hydrogen peroxide, and produces a violet colored complex whose color intensity is directly proportional to the uric acid concentration in the sample. data processing; analysis and description were performed by the use of (statistical package for social science spss version 21), frequency and percentage were used for qualitative variable, while mean and standard error were used for quantitative variable. results tables (1 and 2) illustrate the caries experience (dmft, dmfs and its components ds, ms and fs) among dental students according to dental environment stress levels for the total sample. the mean value of dmft and ds fraction was higher among severe stress level with statistically nonsignificant difference (p≥0.05), while dmfs, fs and ms fractions were higher among moderate stress level with statistically non-significant difference (p≥0.05). table (3) demonstrates the mean value of salivary flow rate and uric acid. the mean value of j bagh college dentistry vol. 32(1), march 2020 the impact of dental 37 flow rate was lower among severe dental environment stress category than mild dental environment stress category, statistically the difference was not significant (p≥0.05), while the mean value of salivary uric acid was higher among severe dental environment stress category than mild dental environment stress category with statistically significant difference (p< 0.05). table (4) demonstrates the correlation between salivary physicochemical characteristics and dental caries. the caries experience caries (dmft, dmfs and its components ds, ms and fs) were negatively correlated with flow rate among students with mild dental environment stress except for the ds and positively correlated with flow rate; while among the student with severe dental environment stress there was negative correlation between the caries experience and flow rate. there were negative correlations between uric acid and caries experience except for the ms and fs which were positively correlated with uric acid among students with mild dental environment stress; while among students with severe dental environment stress the caries experience were positively correlated with uric acid except for ds and ms which were negatively correlated with uric acid, however all these correlations were statistically not-significant (p≥ 0.05). table 1: caries experience (dmft, dmfs) of dental students according to dental environment stress levels table 2: caries experience (dmfs and its components ds, ms and fs) of dental students according to dental environment stress levels table 3: salivary physicochemical characteristics among dental students of mild and severe dental environment stress variable stress level n mean se f p-value dmfs mild 83 9.37 0.899 0.087 0.916 moderate 141 9.84 0.753 severe 76 9.72 0.756 dmft mild 83 5.30 0.438 0.461 0.631 moderate 141 5.46 0.347 severe 76 5.88 0.412 variable stress level n mean se f p-value ds mild 83 3.33 0.390 0.748 0.474 moderate 141 2.89 0.253 severe 76 3.38 0.411 ms mild 83 1.02 0.268 1.079 0.341 moderate 141 1.24 0.226 severe 76 0.72 0.243 fs mild 83 5.02 0.685 0.308 0.735 moderate 141 5.72 0.626 severe 76 5.63 0.612 variable stress level statistical test mild severe n mean sd n mean sd t-test df p-value flow rate ml/min 55 0.804 0.358 40 0.715 0.282 1.299 93 0.197 uric acid mg/dl 55 5.142 1.706 40 6.059 2.485 2.134 93 0.035 j bagh college dentistry vol. 32(1), march 2020 the impact of dental 38 table 4: correlation coefficient of caries experience (dmft, dmfs and its components ds, ms and fs) with salivary physicochemical characteristics according to dental environment stress levels correlations stress level ds ms fs dmfs dmft mild flow rate ml/min r 0.002 -0.179 -0.056 -0.110 -0.076 p 0.989 0.191 0.684 0.424 0.583 uric acid mg/dl r -0.111 0.000 0.035 -0.035 -0.075 p 0.418 0.999 0.798 0.799 0.586 severe flow rate ml/min r -0.049 -0.074 -0.011 -0.003 -0.018 p 0.764 0.650 0.948 0.983 0.913 uric acid mg/dl r -0.147 -0.088 0.001 0.004 0.018 p 0.365 0.588 0.996 0.978 0.914 discussion the defensive elements of saliva and the relationship between oral diseases and psy-chological components were taken into consideration. it is surprising how minimal psychological stress can adjust the safeguard element in saliva. in this study the dental caries was higher among severe dental environment stress category than other categories, the increase of dental caries occurrence with increased stressful situation agrees with other studies.(32-33) this might be because of affecting the immunity and weakening the host defense to cariogenic bacteria (34), by the increase of the secretion of catecholamines and corticosteroids in serum and saliva. the cortisol level of the body increases during stress producing acid creating a favourable environment for bacteria,(35) by unhealthy meals eating prompting frequent snacking and increase the intake of sugar rich diet,(36-35) by weakening the execution of self-care behavior (flossing teeth, brushing teeth) prompting poor oral cleanliness making great condition for microbes,(37) by diminishing salivary flow prompting diminished removal of cariogenic bacteria subjective oral dryness and unstimulated salivary flow were connected with stress to decrease the protective functions of saliva, increasing the vulnerability to dental caries.(20,38-39) although a lower unstimulated salivary flow rate was found in the severe stress group, this difference did not reach statistical significance; the same result was found by other studies.(20,40-41) this is because anxiety and fear may influence salivary flow through pathways in the amygdala, the hypothalamus, and the brainstem.(42) the salivary flow rate was negatively correlated with caries experience among students with severe stress level and this agrees with other studies.(43-45) this may be because of the important action of salivary flow rate as washing action and the defensive components of saliva increase with increasing salivary flow rate,(44) while among mild stress category the flow rate was positively correlated with ds; this agree with other studies.(20) this may be due to higher flow rate; the flow rate may have little effect on the activity of caries at a specific point in time and determination of salivary flow rate at one-time may not be thorough estimation of salivary flow actions.(46) in this study the uric acid was significantly higher among students with severe dental environment stress than those with mild dental environment stress; the same result was found by other studies.(39) antioxidant one of the protection components against oxidative stress is available in all body liquids and tissues, uric acid is the major anti-oxidant of the saliva which comprises more than 85% of saliva total antioxidant capacity (tac) which may be increased as a protection mechanism during stress,(23,46-47) or maybe the adaptive response to a long dated expanded oxidative stress can result in high antioxidant of saliva,(48) or might be because of a significant number of the constituents of saliva changes with flow rate and as the flow rate declines during stress so the antioxidant may be increased for this cause.(49) goodman found that with activation of hippocampal during stress uric acid level increased.(50) the data of present current study found that uric acid was weak and negatively correlated with dental caries; the same result was found by other studies.(23,51-52) this may be due to enhanced production of reactive oxygen species (ros) in the presence of bacteria by increased activity of neutrophils and monocytes in the oral cavity during phagocytosis.(23) in contrast, other studies(53) found positive correlation between tac and dental caries and explained that a raise in total antioxidant capability of saliva could create alterations in the adherence of streptococcus to the dental plaque and lead to more cariogenic action. in evaluating caries risk the determining of single salivary antibacterial component is not significant.(54) therefore, further experimental and j bagh college dentistry vol. 32(1), march 2020 the impact of dental 39 clinical studies are required for progress to estimate the anticarious activity of uric acid. conclusion the results of this study maintain that the salivary flow rate and uric acid may serve as a biomarker of stress, which affects the oral health as showed by the 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مهارات مثل طالب كلية طب االسنان يحتاجون الى اكتساب الكفاءات المتنوعة من امراض الفم تكون مصاحبة للضغط.العديد الخلفية: . حمض اليوريك هو مضاد االكسدة الرئيسي في اللعاب. من الضغط والتي تكون مصحوبة بمستوى عال سريرية, وخبرة في العالقات الشخصية ن ان تعادل التأثير القاتل للجراثيم للجزيئات التي تحفز الضغط التأكسدي الموجودة في اللعاب الكميات الكبيرة من مضادات االكسدة اللعابية من الممك صفيحة الجرثومية, وبذلك تدعم نمو تسوس االسنان.وال ن وعالقته الهدف من هذه الدراسة هو تقييم تسوس االسنان لطالب كلية طب االسنان لديهم مستويات مختلفة من الضغط الناجم عن بيئة طب االسنا كيميائية للعاب الغير محفز. -بالخصائص الفزيو ( عام, الذين تم اختيارهم من كلية 23-22اناث( اعمارهم تتراوح بين )227ذكور, 73طالب طب اسنان ) 300مواد وطرق البحث: العينة الكلية كانت مقياس الضغط لبيئة طب االسنان الى ثالثة اقسام )ضغوط طب االسنان/جامعة بغداد. حيث تم اختيارهم من المرحلة الرابعة والخامسة, تم تصنيفهم وفق سنان باستخدام مؤشر االسنان وسطوح االسنان المفقودة والمعالجة والمتسوسة قليلة, ضغوط متوسطة, ضغوط شديدة(. تم تشخيص وتسجيل تسوس اال (dmft, dmfs )وفقا لمعاييرwho. 28ذكور, 27) طالب من الذين لديهم مستوى ضغوط قليلة 95من تم جمعها عينات اللعاب الغير محفز . وتم وتحليلها كيميائيا لتحديد تركيز حمض اليوريك اللعابي تدفق العابنسبة لتقييم اناث( 29ذكور, 11)والذين لديهم مستوى ضغوط شديدة اناث( . 21النسخة spssتحليل جميع البيانات باستخدام برنامج ( كان لدى الذين لديهم ضغوط شديدة من مقياس الضغط لبيئة طب االسنان مع عدم dsوللجزء ) dmft)النتائج: اظهرت النتائج ان قيمة متوسط ل ) ≤p)( كانت اعلى لدى الذين لديهم ضغط متوسط مع عدم وجود اختالفات معنوية dmfs, fs, ms, بينما )(p≥ 0.05)وجود اختالفات معنوية j bagh college dentistry vol. 32(1), march 2020 the impact of dental 41 اظهرت نتائج تحليل اللعاب ان تدفق اللعاب كان اعلى لدى مجموعة الضغط القليل من مجموعة الضغط الشديد مع عدم وجود اختالفات معنوية, .(0.05 الطالب الذين لديهم مجموعة مع تسوس االسنان لدى كانت عالقته سالبة تدفق اللعاب .الضغط الشديد كان اعلى لدى مجموعة حمض اليوريكبينما مع تدفق اللعاب كانت موجبة لدى طالب الصغط القليل. عالقة حمض اليوريك مع ال dsوالذين لديهم ضغوط شديدة ماعدا عالقة ال وط قليلةضغ dmft العالقات كانت احصائيا غير , مع ذلك كل هذه كانت سالبة لدى طالب الضغط القليل, بينما طالب الضغط الشديد كانت هذه العالقة موجبة معنوية. الذين لديهم الفم, شوهدت باالنتشار االعلى لتسوس االسنان لدى طالب طب االسنانله تأثير على صحة يبدو ان ضغط بيئة طب االسنان االستنتاج: ضغوط متوسطة وشديدة وذلك بتأثيره على المستويات الطبيعية لتدفق اللعاب وحمض اليوريك. االسنان, الضغط, تسوس االسنان, تدفق اللعاب, حمض اليوريك. ضغط بيئة طب :المفتاحية الكلمات dropbox 12 alhan f 70-74.pdf simplify your life dropbox 8 nibal f 42-47.pdf simplify your life mustafa.doc j bagh college dentistry vol. 27(2), june 2015 histological and oral diagnosis 72 histological and mechanical evaluation of the osseointegration of titanium implants by the modifications of thread design and/or coating with flaxseed (an experimental study on rabbits) mustafa h. jawad, b.d.s. (1) athraa y. al-hijazi, b.d.s., m.sc., ph.d. (2) abstract background: dental implant surface technologies have been evolving rapidly to enhance a more rapid bone formation on their surface and improve implant therapy.implant threads should be designed to increase surface contact areathat induced better stability. in addition, implant surface coating with flaxseed was used to enhance bone formation at the bone-implant interface. materials and methods: ninety-six commercially pure titanium (cpti) screws were implanted in rabbits' tibiae and divided into three groups as dual-threaded group, flaxseed-coated group and control group. all groups were evaluated mechanically, histologically and radiographically after each healing periods (2, 4, 6 and 8) weeks and the resulting data were statistically analyzed using anova and t-test at 0.05 significance level. results: dual threaded implant recorded the highest value in removal torque testand it showed mature bone at 8 weeks period. coated implant shows enhancement of osteoblast and it is the only modified implant that illustrates proliferating cartilage zone that later on degenerated and replaced by bone. conclusion: each modified implants shows different benefits whether a modification of the implant surface mechanically (dual-threaded) or by coating the implants with flaxseed. keywords: bone formation, titanium implant, thread design, flaxseed. (j bagh coll dentistry 2015; 27(2):72-78). introduction implants could be considered predictable tools for replacing missing teeth or teeth that are irrational to treat (1). dental implant is defined as a “prosthetic device of alloplastic material(s) implanted into theoral tissues beneath the mucosal and/or periosteal layer, and/or within the bone to provide retention and support for a fixed or removable prosthesis” (2). today, implant success is evaluated from the esthetic and mechanical perspectives. both depend on the degree and integrity of the bond created between the implant and the surrounding bone. osseointegration actually refers to a structural and functional fusion of the implant surface with the surrounding bone. many factors affect osseointegrationsuch as surgical technique, host bed, implant design, implant surface, material biocompatibility and loading conditions (3). implant design refers to the three-dimensional structure of the implant, with all the elements and characteristics that compose it. implant design features are one of the most fundamental elements that have an effect on implant primary stability and implant ability to sustain loading during or after osseointegration. (1) msc student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. hence, implant threads should be designed to maximize the delivery of optimal favorable stresses while minimizing the amount of extreme adverse stresses to the bone implant interface. in addition, implant threads should allow for better stability and more implant surface contact area (4). the thread lead and pitch are important thread characteristics that affect bone-implant contact, stress distribution and primary stability. thread pitch refers to the distance from the center of the thread to the center of the next thread, measured parallel to the axis of a screw (5).pitch differs from lead, which is the distance from the center of the thread to the center of the same thread after one turn or, more accurately, the distance that a screw would advance in the axial direction if turned one complete revolution.in a single-threaded screw, lead is equal to pitch; however in a double threaded screw; lead is double the pitch (figure 1). an implant with double threads would insert twice as fast the single threaded (4). studies found that implants with more threads (lower pitch) had a higher percentage of bone-implant contact. the pitch is considered to have a significant effect among implant design variables, because of its effect on surface area (6). j bagh college dentistry vol. 27(2), june 2015 histological and oral diagnosis 73 figure 1: single threaded and dual threaded implant there are two essential fatty acids (efas) in human nutrition: alpha-linolenic acid (ala), an omega-3 fatty acid, and linoleic acid (la), an omega-6 fatty acid. efas are required for the structure of cell membranes and, because they are unsaturated, they help keep membranes flexible. they serve as precursors of eicosanoids, a group of powerful compounds that affect many biological processes, including the aggregation or clumping of blood platelets and the constriction of blood vessels. efas also help maintain the barrier of the skin and are involved in cholesterol metabolism (7). flaxseed (binomial name: linumusitatissimum) contains a mixture of fatty acids. it is rich in polyunsaturated fatty acids, particularly ala, the essential omega-3 fatty acid (57%), and linoleic acid (16%), the essential omega-6 fatty acid. these two polyunsaturated fatty acids (pufas) are essential for humans, that is, they must be obtained from the fats and oils in foods because our bodies cannot make them (8,9). materials and methods commercially pure titanium (cpti) rods (30 cm in length and 5 mm in diameter) were machined to form 96 screw-shaped implants by using lathe machine. each screw was 8 mm in length (5 mm threaded and 3 mm smooth) and the diameter was 3.5 mm in the threaded part and 4mm in the smooth part. implants were divided as follows: 1. dual-threaded group (32 implants). 2. single-threaded coated with grinded flaxseed group (32 implants). 3. single-threaded (control) group (32 implants). thirty-two adult male new zealand white rabbits ranging in weight from 1.75 – 2.75 kg were used in this study. all animals were radiographed prior to surgery to ensure that the bone of the tibia was sufficient to accept the diameter and length of the implants. general anesthesia was induced by intramuscular injection of ketamine hydrochloride 50 mg/ml (1 ml/kg body weight) and xylazine 20 mg/ml (1 ml/kg body weight). the skin of both tibiae was shaved and cleaned. all instruments used in surgical procedure were autoclaved and the surgical operation was performed gently under sterile condition. incision was made on the lateral side of the rabbit's leg; skin, fascia and muscles were reflected to expose the tibia bone.drilling was performed intermittently by micro-engine with continuous saline irrigation. three screws were implanted in each rabbit; the dual-threaded and coated implants were placed in right tibia (figure 2) while the control one was placed in left tibia (figure 3). coating of the implants was done by dipping technique. figure 2: the dual-threaded and the coated implants in the right tibia figure 3: control implant in the left tibia suturing of the muscles was done with absorbable catgut suture followed by skin suturing with silk suture. an x-ray was taken immediately after the operation to ensure that the implants were properly inserted in their positions (figure 4). figure 4: immediate radiograph after implantation j bagh college dentistry vol. 27(2), june 2015 histological and oral diagnosis 74 the rabbits were divided into four groups according to the healing periods (2, 4, 6 and 8) weeks. at the end of each healing period, eight rabbits were sacrificed; histological, mechanical and radiographical tests were performed for implants. for histological test, the rabbits were scarified and both tibiae were exposed. the bone was cut about 5 mm away from the head of the implant with normal saline cooling to prepare the boneimplant specimen that was prepared as decalcified section. histometric quantification was carried out using a light microscope (olympus, tokyo, japan) at a magnification (x2.5) with grid eyepiece with a good located anatomical reference to measure the width of thread and the distance between two opposing threads. osteoblast, osteocyte and osteoclast counting was performed in five histological sections for each animal and in five microscopic fields at 40x magnification. mechanical test was performed by using torque meter with a range of (0-200 n.cm) which was applied into the slits of implant's head and an anti-clock wise movement was applied to measure the torque force required to unscrew the implants. radiographic examination was doneafter each healing period to assess bone healing around each implant. the resulting data were statistically were statistically analyzed by one-way analysis of variance (anvoa), student t-test and least significant difference (lsd) test. results all animals recovered well after surgery and they moved normally within one week with no weight loss which indicates that they tolerated the implant well. at sacrifice, no signs of gross infection, tissue reaction or any other negative clinical observations were noted around the implant site. radiographically, there were no gross changes in the tibial architecture with no areas of radiolucency between implant and adjacent cortical bone. histological analysis (hematoxylin and eosin stain) control group at 6 weeks duration, new bone surrounds the apex of thread and bone trabeculae coalesce with basal bone (figure 5).at 8 weeks duration, large marrow space filled most of thread and the immature bone was replaced by new bone (figure 6). figure 5: view for thread in control at 6 weeks shows bone trabeculae (bt), osteocytes (arrows heads) and osteoblast (arrow) h&e x20 figure 6: view for threads in control at 8 weeks. h&e x4 dual-threaded implant group at 6 weeks duration, new trabeculated bone filled most of thread (figure 7). at 8 weeks duration, mature bone with osteocytes and haversian canals were shown (figure 8). figure 7: view for thread of dual-threaded implant at 6 weeks duration h&e x20 j bagh college dentistry vol. 27(2), june 2015 histological and oral diagnosis 75 figure 8: view for thread with mature bone fordual-threaded implant at 8 weeks duration h&e x20 implant with flaxseed group at 6 weeks duration, cartilage was surrounded by seed particles and the thread sided by new bone. then, cartilage was degenerated and replaced by new bone which surrounds the threads (figures 9, 10and 11).at 8 weeks duration, immature bone filled the thread and occupies the implant bed. the immature bone shows irregularly arranged osteocytes and haversian canals (figures 12 and 13). figure 9: view shows cartilage (cal) surrounded by flaxseed particles (arrows) for coated implant at 6 weeks. h&e x40 figure10: view for thread sided by new bone (nb)for coated implant at 6 weeks.h&e x20 figure 11: view shows replaced new bone (rb) by degradation of cartilage (arrows)for coated implant at 6 weeks. h&e x40 figure 12: immature bone filled the thread for coated implant at 8 weeks.h&e x20 figure 13: view for immature bone (imb) shows irregular arranged osteocytes (arrow heads) with haversian canal (hc)for coated implant at 8 weeks.h&e x40 radiographical evaluation the result of radiographic evaluation appeared that there were no gross changes in the tibial architecture with no areas of radiolucency between implant and adjacent cortical bone in all specimens for radiographical examination (figure 14). j bagh college dentistry vol. 27(2), june 2015 histological and oral diagnosis 76 figure (14): radiograph of dual-threaded implant, implant with material and control after 8 weeks statistical analysis findings the results illustrate the data of histological measurement for thread separation (µm), thread width (µm), bone cell count (osteoblast, osteocyte, and osteoclast) and the mechanical torque removal values (n.cm2). (table 1) illustrates statistics of histometric and mechanical parameters at different groups distributed in different periods with comparisons significant. the results show the followings: 1. thread separation decreased with increment of the period of implantation. 2. thread width increased with increment of the period of implantation. 3. osteoblast cell count recorded high values at 4 and 6 weeks for all groups. 4. osteocyte cell count recorded a high value at 6 weeks for all groups. 5. osteoclast cell count recorded a high value at 4 weeks for control and dual-threaded groups. 6. torque values increase with increment of the period of implantation and recorded the highest values at 8 weeks for all groups. table 1: descriptive statistics of histometric and mechanical parameters at different groups distributed in different periods with comparisons significant parameters periods group control dual coated no. mean s.d. f-test pvalue mean s.d. ftest pvalue mean s.d. ftest pvalue thread sep. 2nd w 5 14.2 1.64 15 0.000 hs 11 0.71 12.2 0.000 hs 12 0.71 59.1 0.000 hs 4th w 5 14.4 1.34 11 0.71 9.4 0.89 6th w 5 13 0.71 9.8 0.45 7.6 0.55 8th w 5 10 0.71 8.4 1.14 6.6 0.55 thread width 2nd w 5 13.2 1.3 145.8 0.000 hs 22.4 1.82 70.5 0.000 hs 8.6 1.14 65.05 0.000 hs 4th w 5 16.8 0.84 27.2 1.92 12.2 1.48 6th w 5 20.6 0.89 33.6 2.19 19 1.41 8th w 5 26.6 1.14 41.8 2.86 23 2.74 osteoblast 2nd w 5 6 2 22.9 0.041 s 8.6 0.89 85.3 0.000 hs 12.2 3.35 18.71 0.000 hs 4th w 5 11.4 0.89 14.2 0.45 25.8 3.77 6th w 5 11.8 1.48 14.2 0.45 20.8 3.03 8th w 5 7.4 0.55 10.2 0.84 14.6 2.41 osteocyte 2nd w 5 1 0.71 130.1 0.000 hs 3 0.71 132.6 0.000 hs 4.2 0.45 135.4 0.000 hs 4th w 5 5.4 1.14 8.6 0.55 12.8 1.3 6th w 5 11 0.71 10.6 0.89 15 1 8th w 5 6.6 0.55 10.4 0.55 15 1 osteoclast 2nd w 5 0.8 0.45 13.3 0.000 hs 3 1 10.5 0.000 hs 4 1.22 9.33 0.001 hs 4th w 5 2.8 0.84 1.6 0.55 2.6 0.55 6th w 5 1 0.71 1.4 0.55 2.6 0.55 8th w 5 0.4 0.55 0.6 0.55 1.2 0.84 removal torque value 2nd w 5 5.4 1.14 122.6 0.000 hs 7.6 1.82 321.9 0.000 hs 6.6 2.07 282.3 0.000 hs 4th w 5 12 2.12 17 2 8.6 0.89 6th w 5 18.8 1.1 29.8 2.05 22.6 2.51 8th w 5 34 4.18 48 2.74 42 2.74 (*) hs: highly sig. at p< 0.01; s: significant at p<0.05 discussion all animals tolerated the implantation well; no sign of cross infection, tissue reaction or any other negative clinical indications like mobility of the implants were noted around the implants site. this study discussed different designs of selected implants, single-threaded implant (control), dual-threaded implant and implant coated with grinded flaxseed. j bagh college dentistry vol. 27(2), june 2015 histological and oral diagnosis 77 mechanical test all implants were stable during healing periods in the sense that they could not be removed with manual force without the aid of the torque gage instrument. removal torque values were increasing with advancing time and significant differences between different time periods was present. a comparison between the different implantation periods shows that the minimum torque value was seen in 2 weeks implantation time while the maximum value was observed in 8 weeks implantation time for the studied groups. these increased values can be attributed to progressive bone formation, maturation and bone remodeling around the implant as time. these findings of increased torque values with time were in accordance with previous studies (10, 11). histological findings dual threaded implant dual-threaded implant records the highest mean value in thread width and the mean values of removal torque in proceeding periods; histologically, it shows mature bone at 8 weeks period. these results can be explained that the implant design features are one of the most important elements that have an effect on implant primary stability and implant ability to sustain loading during or after osseointegration(4). in addition, increased surface area of dual-threaded implant led to increased bone to implant contact that improved the interaction between them, increased primary stability and provided a better distribution of forces to the surrounding bone. implant with flaxseed the present results reported that coated implant with flaxseed show enhancement of osteoblast and its progenitor cells with highest mean value in bone cell count records and illustrated a proliferating cartilage zone. this result can be attributed to that the flaxseed powder acts as micro roughed area, which maximizes the interlocking between mineralized bone and implant surface. cells have mechanoreceptor properties that can identify whether or not the surface has features appropriate to begin the process of differentiation (12). the surface roughness of the implants can significantly alter the process of osseointegration because the cells react differently to smooth and rough surfaces. in addition, enhancement of osteoblast and chondroblast by flaxseed may related to flax contains of a mixture of fatty acids. it is rich in polyunsaturated fatty acids, particularly alpha-linolenic acid (ala), the essential omega-3 fatty acid, and linoleic acid (la), the essential omega-6 fatty acid. these two polyunsaturated fatty acids (pufas) are essential for the structure of cell membranes .they serve as precursors of eicosanoids, a group of powerful compounds that affect many biological processes (13). normally, osteoblasts attach on the implant surface from first day of implant insertion, but in our results, chondroblasts seemed to be prominent at first period, forming a cartilage as scaffold, then, replaced by bone with presence of active, and proliferative osteoblast cells. references 1. lang np, salvi g. implants in restorative dentistry. in: lindhe j, lang np, karring t (eds). clinical periodontology and implant dentistry. 5th ed. denmark: blackwell munksgaard; 2008. p. 1138– 1145. 2. o'brien wj. dental materials and their selection. 4th ed. hanover park, il: quintessence pub. co.; 2008. 3. albrektsson t, brånemark pi, hansson ha, lindström j. osseointegrated titanium implants. requirements for ensuring a long lasting, direct bone‑to‑implant anchorage in man. acta orthop scand 1981; 52:155‑70. 4. abuhussein h, pagni g, rebaudi a, wang hl. the effect of thread pattern upon implant osseointegration. clin oral impl res 2010; 21: 129–36. 5. misch ce, strong t, bidez mw. scientific rationale for dental implant design. in: misch ce (ed.) contemporary implant dentistry. 3rd ed. st louis: mosby; 2008. p.200–229. 6. steigenga jt, al-shammari kf, nociti, fh, misch ce, wang hl. dental implant design and its relationship to long-term implant success. implant dentistry 2003; 12: 306–17. 7. horrobin df, manku ms. clinical biochemistry of essential fatty acids. in: omega-6 essential fatty acids, edhorrobin df, alan r. liss, new york, 1990; p. 21-53. 8. mason jk, thompson lu. flaxseed and its lignan and oil components: can they play a role in reducing the risk of and improving the treatment of breast cancer? appl physiol nutr metab 2014; 39(6): 663-78. 9. muíño i, apeleo e, de la fuente j, pérezsantaescolástica c, rivas-cañedo a, pérez c, díaz mt, cañeque v, lauzurica s. effect of dietary supplementation with red wine extract or vitamin e, in combination with linseed and fish oil, on lamb meat quality. meat sci 2014; 98(2):116-23. 10. al-mudarris ba, salem sa, al-zubaydi tl. the significance of biomimetic calcium phosphate coating on commercially pure titanium and ti-6al-7nb alloy. a phd thesis, college of dentistry, university of baghdad, 2006. 11. hammad t, al-ameer ss, al-zubaydi t. histological and mechanical evaluation of electrophoretic bioceramic deposition ti-6al-7nb dental implant. phd thesis, college of dentistry, university of baghdad, 2007. 12. carlos ne. factors affecting the success of dental implants, implant dentistry a rapidly evolving j bagh college dentistry vol. 27(2), june 2015 histological and oral diagnosis 78 practice, prof. ilserturkyilmaz (ed.) 2011; isbn: 978-953-307-658-4. 13. hurteau mc. unique new food products contain good omega fats. journal of food science education 2004; 3(4): 52-3. الخالصة أما الجزء المسنن .عالج الزرعتعجیل إمكانیةلزیادة سطح وتلك األعلى بشكل أسرع عظمكونالت فیزر بسرعة لتحتتطو زرعات السنیةسطوح ال تقنیاتان :الخلفیة فیزلَتحور الكتان ذتم طالء الزرعة بمادة ب, لكذاضافة ل. من الزرعة فیجب أن یصمم لزیادة مساحة االلتصاق السطحیة للحصول على استقرار أفضل للزرعة .عظمكونالت , الى ثالث مجموعات وھي زرعات مسننة ثنائیاوقسمت مصنوعة من التیتانیوم النقي التجاریقد زرعت في ساق األرنب زرعةستة وتسعون :المواد وطرق العمل أسابیع ) 8و 6,4,2(نسیجیا وشعاعیا بعد انتھاء كل فترة عالج , میكانیكیا تم تقییم كل مجموعة. ور الكتان المطحونة و زرعات سیطرةذزرعات مطلیة بمادة ب .0.05عند مستوى معنویة tو اختبار ) anova(اباستخداماختبارتحلیاللتباین یحللتالبیاناتالناتجةإحصائو ور الكتان ذأما الزرعات المطلیة بمادة ب. بعد ثمان أسابیعدوران وأظھرت تكون عظما ناضجا السجلت الزرعات المسننة ثنائیا أعلى قیم المتوسط في عزم :النتائج .فقد أظھرت تحسین الخالیا المكونة للعظم كما أنھا الوحیدة التي بینت تكون منطقة غضروفیة والتي ستتحلل الحقا وتستبدل بالعظم أو ) زرعات مسننةثنائیا(لك في تحویرات أسطح الزرعات میكانیكیا ذنستنتج من النتائج الحالیة بأن كل تحویر للزرعات أظھر منافع مختلفة سواء كان :الخاتمة .ور الكتان المطحونةذطالء أسطحھا بمادة ب j bagh college dentistry vol. 29(2), june 2017 dental caries and pedodontics, orthodontics and preventive dentistry 108 dental caries and treatment needs in relation to nutritional status among children with congenital heart disease marwa jamal al-haidary, b.d.s.(1) nada j. radhi, b.d.s., m.sc., ph.d.(2) abstract background: congenital heart disease is one of the most common developmental anomalies in children. these patients commonly have poor oral health that increase caries risk. dental management of children with congenital heart disease requires special attention, because of their heightened susceptibility to infectious endocarditis. the aims of this study were to assess the severity of dental caries of primary and permanent teeth and treatment needs in relation to nutritional indicator (body mass index) among children with congenital heart disease. materials and methods: in this case-control study, case group consisted of 399 patients aged between 6-12 years old with congenital heart disease were examined for dental status in ibn al-bitar specialized center for cardiac surgery in baghdad/iraq. a case-matched group (healthy control) of 485 children was also examined from primary schools in baghdad city. diagnosis and recording of dental caries and treatment needs were recorded according to the criteria of who (1997). the assessment of nutritional status (bmi) was performed following centers for disease control and prevention growth chart (2000). all data were analyzed using ibmspss version 23. results: results recorded the highest mean rank value of (dmfs)and (dmfs) were among chd cases than control group with statistically high significant difference. results revealed the mean rank values of (ds, ms, fs and dmfs) were higher at age group 6-7 years among chd cases, while the mean rank values of (ds, ms, fs and dmfs) were higher at age group 12 years with statistically high significant difference among age group. the mean rank values of all types of treatment needs were recorded to be higher among chd cases than control group, except for children no treatment needs, these differences were statistically highly significant. also this study found that the mean rank values of caries experience (ds, ms, fs and dmfs) were higher among wasted than well nourished chd cases with statistically highly significant for dmfs. moreover, the mean rank values of all types of treatment need required were higher among wasted chd cases than well nourished; however, the differences were statistical highly significant. conclusion: the study revealed that these children are “at risk” from dental disease and malnourished, the primary focus should be on oral hygiene instructions, the awareness of infective endocarditis and they required a development of preventive programs. key words: congenital heart disease, dental caries, treatment need, bmi. (j bagh coll dentistry 2017; 29(2):108-114) introduction congenital heart disease (chd) refers to the structural or functional heart defect which is present at birth, it is one of the leading causes of morbidity and mortality in the first years of life (1,2). there are many types of congenital heart defects, they range from simple defects with no symptoms to complex defects with severe, lifethreatening symptoms but the most common anomalies ventricular septal defect (vsd) and aterial septal defect (asd) (3). clinically classified depending on the existence of cyanosis, in acyanotic which are characterized by physiological amount of oxygen in arterial blood and normal skin color; in cyanotic characterized by reduced oxygen in arterial blood and cyanotic skin color (4,5). bad oral hygiene that usually associated with these children may be largely attributed to cardiac disease (6,7). studies have shown significant findings regarding poor oral health, especially periodontal status, dental caries and dental procedures are risk factors in these patients (6,8). (1) m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assist. professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. in addition, several studies showed that dental caries had a higher prevalence and severity among children with congenital heart disease when compared to healthy controls (9,10,11). the oral microbiological flora plays a very important role in the etiopathogenesis of bacterial endocarditis, given the condition that it is of oral or dental origin (12). untreated dental decay in paediatric cardiac patients has a significant implication in the medical care of these patients, as it may develop into pulp infections which are associated with bacteraemia, endocarditis, and even brain abscesses (7,13). the severity of growth disturbance depend on the anatomical defect of heart and its functional defect, however, most children with mild defect grow normally but gaining weight slower than normal, who describe a list of growth problem with z score lines (7, 5, 9, 14). panggabean et al observed that malnutrition more prevalent and more severe in children with chd than healthy (15). a study of al-etbi revealed that 60% of children among vsd groups were in malnourished status (11).yet, in iraq, no study was conducted regarding severity of dental caries and treatment need in relation to nutritional status (bmi) among different types of chd children j bagh college dentistry vol. 29(2), june 2017 dental caries and pedodontics, orthodontics and preventive dentistry 109 congenital heart disease for this reason, the study was designed. materials and methods the sample involved children with congenital heart disease (cases) consisted of 399 males and females aged between (6-12) years according to the last birthday (16).this study was carried out during the period between december, 2015 and may, 2016. collection sample (cases) includes all patients attending the hospital from december 2015 to march 2016, firstly, diagnosed by the specialist as having different type of congenital heart disease attended to ibn al-bitar specialized center for cardiac surgery for diagnosis, treatment and follow up. all children were examined with no medication for at least three months ago from start of examination date. the control group consisted of 485 students selected randomly matching with age and gender from primary schools in baghdad city; they are healthy without any systemic disease (from personal file). diagnosis and recording of dental caries (dmfs, dmfs) and treatment need were recorded according to the criteria of who 1997 (16) using plane mouth dental mirrors and (cpi) probe. the assessment of nutritional status was performed using bmi following centers for disease control and prevention growth chart (17). bmi was calculated by dividing weight of each child in kilogram by his/her length^2 in meter. non-normally distributed variables were conveniently presented by median and mean rank. the difference in median between 2 groups was assessed by non-parametric test (mann-whitney), while between 3 groups kruskal-wallis test was used; and the differences between percentages chi-square (2) test was used. data analysis was conducted by application of ibmspss program version 23. results table (1) illustrates the distribution of total sample by age. the high percentage of children was found at age group 6-7 years old among both groups. the median and mean rank of caries experience and its component of primary and permanent teeth (ds, ms, fs and dmfs; ds, ms and fs and dmfs) respectively among chd cases and control group are seen in table (2). results showed that the mean rank values of caries experience and its components of primary and permanent teeth were higher among chd cases than control group, except for (fs and fs), all these results were statistically high significant (ds: z=-17.152, mann-whitney=33447.0; ms: z=7.493, mann-whitney=76607.0; fs: z=-5.984, mann-witney=87134.0; dmfs: z=-16.529, mannwhitney=35160.0; ds: z=-10.265, mannwhitney=71756.5; ms: z=-4.304, mannwhitney=93120.0; fs: z=-2.547, mannwhitney=92905.5; dmfs: z=-7.875, mannwhitney=75617.5), (p<0.01). concerning age, the median and mean rank of caries experience and its component of primary teeth (ds, ms, fs and dmfs) among chd cases is shown in table (3). results showed that the mean rank values of (ds and fs) were higher at age group 6-7 years, with statistically highly significant (ds: chi=174.182, df=3; fs: chi=5.319, df=3;), (p<0.01).while for permanent teeth, table (4) illustrates the median and mean rank of caries experience and its component of permanent teeth (ds, ms, fs and dmfs) among chd cases by age. the mean rank values of caries experience (ds, ms, fs and dmfs) were found to be higher at age group12 years, with statistical highly significant differences (ds: chi=200.815, df=3; ms: chi=32.977, df=3; fs: chi=26.265, df=3; dmfs: chi=200.295; df=3), (p<0.01). regarding the treatment need, the median and mean rank among both groups seen in table (5). the mean rank values of all types of treatment need were recorded to be higher among chd cases than control group, except for tn0 (no treatment need) recorded opposite picture, these differences were statistically highly significant (tn0: z=-20.225, mann-whitney=20570.0; tn1: z=-22.729, mannwhitney=15434.0; tn2: z=-16.127, mannwhitney=37936.0; tn6: z=-11.156, mannwhitney=68739.0; tn7: z=-7.684, mannwhitney=76180.0), (p˂0.01). table (6) demonstrates the median and mean rank of treatment need required among chd cases by age. all the differences among different age for all type of treatment need were statistically significant however a higher mean rank value for tn0no treatment need was recorded among age group 12 years, while concerning tn1one surface filling recorded higher mean rank value among age group 6-7 years; for tn2 and tn6 mean rank values were higher among age group 8-9 years than other age groups and mean rank value of tn7need for other treatment care was higher among age group 10-11 years (tn0: chi= 206.262, df=3; tn1: chi=21.736, df=3; tn2: chi=96.564, df=3; tn6: chi=15.670, df=3; tn7: chi=15.361, df=3), (p˂0.01). regarding nutritional status, the mean values of (bmi) were lower among chd cases (-0.6±0.11) than control group (0.8±0.09) with statistically highly significant differences z=-12.497, mannwhitney=49334.0), (p˂0.01).also, the distribution of wasting among chd cases by age j bagh college dentistry vol. 29(2), june 2017 dental caries and pedodontics, orthodontics and preventive dentistry 110 are seen in table (7). the percentage of wasting was higher among age group 10-11years but lower in age group of 12 years with statistically significant difference (chi=8.373, df=3, p˂0.05).table (8) demonstrates caries experience and its component of primary and permanent teeth (ds, ms, fs and dmfs; ds, ms, fs and dmfs) respectively according to nutritional indicator body mass index for age (bmi) among chd cases. all mean rank values of caries experience were higher among wasted children than well nourished, while the opposite results for permanent teeth with statistically highly significant for dmfs (z=-3.096, mannwhitney=7257, p˂0.01) and significant for ms (z=-2.297, mann-whitney=8215.5, p˂0.05).the median and mean rank of treatment need required according to nutritional indicator body mass index for age (bmi) among chd cases is shown in table (9). a higher values of mean rank of teeth with tn0-no treatment need and those in need of tn1-one surface filling were observed among well-nourished than wasted, while the opposite was found for other types; however, the differences were statistically highly significant (tn0: z=-1.346, mann-whitney= 8665; tn1: z=-2.135, mann-whitney=8049; tn2: z=-0.835, mann-whitney=9082; tn6: z=-2.099, mannwhitney=8336; tn7: z=-1.879, mannwhitney=8496.5), (p˂0.01). table 1: the distribution of total sample by age (year). age groups chd* cases control group no. % no. % 6-7 172 43.1 179 36.9 8-9 69 17.3 129 26.6 10-11 81 20.3 81 16.7 12 77 19.3 96 19.8 total 399 100.0 485 100.0 *congenital heart disease table 2: the median and mean rank of caries experience and its component of primary and permanent teeth (ds, ms, fs and dmfs; ds, ms, fs and dmfs) among chd* cases and control group. caries experience chd* cases control group no. median mean rank no. median mean rank ds 399 11 601.2 485 0 312.0 ms 0 493.0 0 401.0 fs 0 418.4 0 462.3 dmfs 12 596.9 2 315.5 ds 0 505.2 0 391.0 ms 0 451.6 0 435.0 fs 0 432.8 0 450.4 dmfs 0 494.5 0 398.9 *congenital heart disease table 3: the median and mean rank of caries experience and its component of primary teeth (ds, ms, fs and dmfs) among chd* cases by age (year). age caries experience ds ms fs dmfs no. median mean rank no. median mean rank no. median mean rank no. median mean rank 6-7 172 13 259.7 172 0 196 172 0 202.6 172 14 247.1 8-9 69 13 254 69 0 233.6 69 0 198 69 17 264.4 1011 81 6 150 81 0 217.2 81 0 198 81 10 171.1 12 77 0 70.9 77 0 160.8 77 0 198 77 0 67.6 *congenital heart disease j bagh college dentistry vol. 29(2), june 2017 dental caries and pedodontics, orthodontics and preventive dentistry 111 table 4: the median and mean rank of caries experience and its component of permanent teeth (ds, ms, fs and dmfs)among chd*cases by age(year). age caries experience ds ms fs dmfs no. median mean rank no. median mean rank no. median mean rank no. median mean rank 6-7 172 0 144.5 172 0 192.5 172 0 194.1 172 0 142.6 8-9 69 0 161.3 69 0 192.5 69 0 198.8 69 0 163.2 10-11 81 1 244.8 81 0 202.5 81 0 195.4 81 1 243.3 12 77 4 311.6 77 0 220.9 77 0 219.0 77 4 312.5 *congenital heart disease table 5: the median and mean rank of treatment need required of teeth among chd* cases and control group. type of treatment need chd* cases control group no. median mean rank no. median mean rank tn0-no treatment need 399 16 251.6 485 23 599.6 tn1-one surface filling 3 646.3 0 274.8 tn2two or more surface filling 2 589.9 0 321.2 tn6extraction 0 512.7 0 384.7 tn7need for other care 0 494.1 0 400.1 *congenital heart disease table 6: the median and mean rank of treatment need required among chd* cases by age (year). type of treatment need age 6-7 8-9 10-11 12 no . media n mea n rank no . media n mea n rank no . media n mea n rank no . media n mea n rank tn0-no treatment need 17 2 13 119.8 69 16 186.4 81 18 256.0 77 22 332.5 tn1-one surface filling 4 229.8 3 168.8 3 175.4 3 187.2 tn2two or more surface filling 3 238.2 4 257.1 2 155.2 1 110.7 tn6 extractio n 0 207.0 0 225.8 0 195.4 0 166.0 tn7 need for other care 0 190.3 0 222.2 0 224.1 0 176.6 *congenital heart disease table 7: the distribution of wasting among chd* cases by age (year). age chd* cases wasting total no. % 6-7 172 27 15.7 8-9 69 9 13.0 10-11 81 17 21.0 12 77 4 5.2 *congenital heart disease j bagh college dentistry vol. 29(2), june 2017 dental caries and pedodontics, orthodontics and preventive dentistry 112 table 8: caries experience and its component of primary and permanent teeth (ds, ms, fs and dmfs; ds, ms, fs and dmfs) according to nutritional indicator among chd* cases. caries experience nutritional indicator well nourished wasted no. median mean rank no. median mean rank ds 342 11 196.5 57 12 220.7 ms 0 195.5 0 226.9 fs 0 199.7 0 201.5 dmfs 12 192.7 16 243.7 ds 0 202.5 0 185.1 ms 0 200.7 0 196.0 fs 0 200.6 0 196.6 dmfs 0 201.7 0 186.1 *congenital heart disease table 9: the median and mean rank of treatment need required according to nutritional indicator among chd* cases. treatment need nutritional indicator well nourished wasted no. median mean rank no. median mean rank tn0-no treatment need 342 16 203.2 57 16 181.0 tn1-one surface filling 4 205.0 2 170.2 tn2two or more surface filling 2 198.1 3 211.7 tn6extraction 0 195.9 0 224.8 tn7need for other care 0 196.3 0 221.9 *congenital heart disease discussion this study observed that the caries experience and its components of primary and permanent teeth were higher among chd cases than control group, with statistically high significant differences, these results in line with other studies (9,18-23), however, these finding may be attributed to decrease dental intervention in the cardiac group as compared to the control group may be related to the high complexity of congenital cardiac disease and the greater health demands made by this medical condition (24). many parents mentioned that they had experienced a dentist’s refusal to treat their child, also inadequate professional and home care (19, 22, 18). also, particularly disappointing was that a large number of children brushed their teeth only once or no times per day. paradoxically, this is because the parents and children may be aware that bleeding gums are potentially harmful and are unaware that if gingiva bleed on brushing (19, 25). several studies have shown that socioeconomic conditions may influence oral health status of children with chd (2628). or could be attributed to the change in salivary constituents and parameters that related to increase in dental caries experience among chd group (children with vsd) compared to the control group (11). another explanation could be due to the digoxine which is cardiac glycoside medication mostly named sugar loaded medicine (sweetened with 30-50% sugar) which related to dental caries(9, 29). since dental caries is a chronic disease with accumulative effect, in spite that, chd group in this study with no medication for just three months ago. the present study recorded that the caries experience in the primary dentition among chd cases was decreased with age, the same findings were in other studies among healthy children (30-32). this may be related to decrease in number of primary teeth with advanced age (the natural shedding of primary teeth) (33). this was confirmed by study of al-etbi among chd children (11). also, this may explain that the criteria of one surface filling need (tn1) decrease gradually with increase age among chd children according to the results of this study. however no iraqi study was found regarding dental treatment need among chd cases. concerning permanent dentition, the mean rank values of caries experience were higher at age group12 years than other age groups this may be related to the accumulative nature of caries lesion that increase with age (34, 35). this study revealed that the chd cases need for more dental treatment and oral health care with preventive program than control group, as a high caries experience among chd cases was noticed, in addition, the majority of studies with heart disease patients of all ages reported that the dental health of these subjects is usually poor (19, 21, 36). j bagh college dentistry vol. 29(2), june 2017 dental caries and pedodontics, orthodontics and preventive dentistry 113 the values of bmi was compared according to cdc growth according to the age and gender because unavailability of iraqi standard for comparison (19). regarding nutritional status, the mean values of (bmi) were lower among chd cases than control group with statistically highly significant differences. it is a popular view that children with congenital heart disease are often small and undernourished (37,38). this also found by previous iraqi study among vsd group (11). also, the adverse impact of chd on growth has been reported by many studies and they attributed to the effects of increased total energy expenditure in these patients (3943). concerning age, the percentage of wasting was higher among age group 10-11years but lower in age group of 12 years with statistically significant difference. this may attributed to that medical condition of those children with congenital heart disease become better due to spontaneous closure of defect with time because some of cases require no treatment just periodic follow up and prophylaxis or other cases resolved with non-surgical intervention (5, 44), other possible cause, with age, the ability of children to depend on themselves to rely dietary requirement and take meals increase gradually because of normal development, which is reflected on their nutritional status positively with increased nutritional requirements commensurate with the growth of objects. in present study the caries experience (dmfs) were found to be higher among wasted than well-nourished chd cases, and this may explain that the higher dental treatment was needed among wasted than wellnourished chd cases. this study is in agreement with al-etbi (11). the increased severity and prevalence of dental caries among malnourished children may be attributed to the nutritional deficiency which increase tooth susceptibility to dental caries by changing in tooth formation or in the quality of the hard tissues of the tooth that can be affected by nutrition (44). referances 1boon n, colledge a, ewald d, knight b, wheaton g. davidson principles and practice of medicine, 20th ed. churchill livingstone, oxford, 2006. 2shah g, singh m, 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status of children with congenital heart disease. br heart j 1995; 73:277-283. 38weintraub g, menahem s. early surgical closure of a large ventricular septal defect: influence on long term growth. j am coll cardiol 1991; 18:552-558. 39ackerman l, karn a, denne c, ensing j, leitch a. total but not resting energy expenditure is increased in infants with ventricular septal defects. pediatrics 1998; 102:1172-1177. 40varan b, tokel k, yilmaz g. malnutrition and growth failure in cyanotic and acyanotic congenital heart disease with and without pulmonary hypertension. arch dis child 1999; 81:49-52. 41rhee k, evangelista k, nigrin j, erickson c. impact of anatomic closure on somatic growth among small asymptomatic children with secundum atrial septal defect. am j cardiol 2000;85:1472-1475. 42vaidyanathan b, roth j, rao g, gauvreau k, shivaprakasha k, kumar k. outcome of ventricular septal defect repair in a developing country. j pediatr 2002; 140:736-741. 43eroglu a. qztunc f. saltic l. evolution of ventricular septal defect with special reference to spontaneous closure rate, subaortic ridge and aortic valve prolapsed. pediatric cardiol. 2003;24:31. 44cecillia a, tiffany u. nutrition and periodontal disease. in: nutrition 3rd ed. 2000. p.1225-33. المستخلص الفمویة ضعیفة الصحةعادة لدیھم الخلقيالقلب بمرض المصابین األطفال شیوعا في األطفال. التنمویةالعیوب أكثرواحد من ھوالخلقي القلب مرض ألخلفیة : الذین یعانون من مرض القلب الخلقي تتطلب اھتماما خاصا، بسبب قابلیتھم المتزایدة األطفال بأسنان العنایة. األسنانالذي یزید مخاطر االصابھ بتسوس األمر لدى مؤشر التغذیة العالج وعالقتھا مع احتیاجات والدائمیھ مع اللبنیة األسنانلتقییم شدة تسوس كانت الدراسةھذه أھداف إنلالصابھ بالتھاب شغاف بطانة القلب. .الخلقيالقلب بمرضالمصابین األطفال مرض الذین یعانون من سنھ 12-6 أعمارھممریضا تتراوح 399والتي تكونت من الحالةلمجموعة األسنان,تم فحص المقارنة الدراسةالمواد والطرق : في ھذه ابتدائیةطفل تم فحصھم من مدارس 485) من الضابطة( المطابقة ألمجموعھ إمافي المركز التخصصي ابن البیطار لجراحة القلب في بغداد/العراق. الخلقيالقلب التغذویھ (مؤشر كتلة الجسم) الحالة). تم تقییم 1997( یةالعالم الصحةالعالج وفقا لمعاییر منظمة احتیاجاتو اإلنسانفي مدینة بغداد. تم تشخیص وتسجیل تسوس .23 ألنسخھ ibmspss). وتم تحلیل جمیع البیانات باستخدام 2000على المرض ( والسیطرة الوقایةوفق خریطة نمو مركز مقارنھ بالمجموعة الضابطة مع اختالفات خلقيالقلب ال مرضبین األطفال المصابین ب dmfs)و(dmfs) سجلت النتائج أعلى قیمھ للرتب الوسطیة ( النتائج : لدى حاالت مرض القلب ) سنوات7-6) كانت للفئة العمریة (ds, ms, fs, and dmfsالنتائج إن أعلى قیم للرتب الوسطیة ( كشفت.p˃0.01)معنویة عالیھ ( قد سجلت أعلى قیم للرتب ة. ) سنھ مع وجود اختالفات معنویة عالی12العمریة ( ) كانت للفئةds, ms, fs, and dmfs, بینما أعلى قیم للرتب الوسطیة (الخلقي , االطفال الذین الیحتاجون إلى عالجمقارنة بأطفال ألمجموعھ الضابطة,باستثناء یھالعالج الحاجات لكل أنواع خلقيقلب الال مرضالوسطیة لألطفال المصابین ب أعلى بین )ds, ms,fs and dmfsھرت نتائج الدراسة إن قیم الرتب الوسطیة شدة التسوس ومكوناتھ لألسنان اللبنیة (وأظ. وكانت ھذه االختالفات معنویة عالیھ عالیھ. معنویة اختالفات مع وجود في حاالت مرض القلب الخلقي الذین یعانون من نقص الوزن والھزال من األطفال الذین الیعانون من نقص الوزن والھزال (tn1,tn0خلقي ماعدالب مرض قمتطلبات العالج أعلى لدى األطفال الھزل من األطفال الغیر ھزال ممن لدیھم لجمیع قیم متوسط الرتبان ك, وعالوة على ذل .مع وجود فروق معنویة عالیھ) والعنایةن التركیز الرئیسي على إرشادات النظافة ، وینبغي أن یكوالمختلفة ھؤالء األطفال "في خطر" من أمراض األسنانأوضحت نتائج الدراسة إن االستنتاج : , أضافھ إلى الحاجة لتطویر البرامج الوقائیة.والوعي حول التھاب شغاف القلب ویھالفم journal of baghdad college of dentistry, vol. 34, no. 4 (2022), issn (p): 1817-1869, issn (e): 2311-5270 9 research article assessment of serum levels of monocyte chemoattractant protein 1 (mcp 1) in patients with periodontitis and atherosclerotic cardiovascular disease safa ali hamad 1*, maha shukri mahmood2 1 master student, ministry of health, baghdad. 2 professor, department of periodontics, college of dentistry, university of baghdad. bab almoadham, p.o. box 1417, baghdad, iraq * correspondence: safa.almahamdah@yahoo.com abstract: background: monocyte chemotactic protein-1 (mcp-1) is a chemokine expressed by inflammatory and endothelial cells. it has a crucial role in initiating, regulating, and mobilizing monocytes to active sites of periodontal inflammation. its expression is also elevated in response to pro-inflammatory stimuli and tissue injury, both of which are linked to atherosclerotic lesions. aim of the study: to determine the serum level of mcp-1 in patients with periodontitis and atherosclerotic cardiovascular disease in comparison to healthy control and evaluate the biomarker's correlations with periodontal parameters. methods: this study enrolled 88 subjects, both males and females, ranging in age from 36-66 years old, and divided into four groups: 1st group with atherosclerotic cardiovascular disease (ascvd) without periodontal disease (25 patients), 2nd group with periodontitis and systemically healthy, (25 patients),3rdgroup having both ascvd and periodontitis (25 patients), and the 4th is the control group without any systemic disease and with good oral hygiene (13 subjects). the clinical periodontal parameters plaque index (pl i), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal) were used to evaluate periodontal health status. atherosclerotic cardiovascular disease patients were chosen after clinical examination by specialists and diagnoses confirmed with catheterization. following clinical assessment, 5ml of venous blood was drawn from each participant mcp-1 levels in the blood were then measured using enzyme-linked-immunosorbent assay (elisa). results: according to the findings of this study, the mean values of pli and bop were higher in periodontitis group and athero+periodontitis group than in athero group and control group, ppd and cal mean values were greater in athero+periodontitis group than in periodontitis group. the serum level of mcp-1 was higher in athero+periodontitis group than in athero, periodontitis and control groups. regarding the correlations between mcp-1 and clinical periodontal parameters. in periodontitis group there was a positive correlation with ppd and cal and there was a positive correlation with cal in athero+periodontitis. conclusion: this study revealed that periodontitis with higher mcp-1 level may be linked to an increased risk of atherosclerosis. keywords: periodontitis, cardiovascular, plasminogen activators, monocyte chemoattractant. introduction periodontal diseases (pds) are inflammatory diseases that affect the tissues that support the teeth. periodontitis is defined as a loss of supportive periodontal tissue, manifested clinically as clinical loss of attachment with gingival bleeding, and pocketing, while loss of alveolar bone is determined by radiography (1). atherosclerosis is a chronic inflammatory disease of the arteries caused by cholesterol accumulation and other physiological factors, and it is the leading cause of heart disease. cardiovascular disease (cvd) is the leading cause of death worldwide. cvd is anticipated to kill 17.3 million people per year, accounting for 30% of all fatalities, and this figure is expected to rise to 23.3 million received date: 10-01-2022 accepted date: 26-02-2022 published date: 15-12-2022 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org /licenses/by/4.0/). https://doi.org/10.2647 7/jbcd.v34i4.3272 mailto:safa.almahamdah@yahoo.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i3.3214 https://doi.org/10.26477/jbcd.v34i3.3214 j. bagh. coll. dent. vol. 34, no. 4. 2022 hamad and mahmood 10 by 2030 owing to enhanced aging and obesity prevalence (2). for over a century, there has been speculation that there is a link between dental health and cvd and according to epidemiological data, persons with periodontitis are more prone to develop the atherosclerotic disease than people without (3). the investigation into potential links between periodontitis and atherosclerosis has intensified, and various correlations and causalities are being studied (4,5) two publications looked at the scientific evidence for these associations: one looked at the function of invading microbes and infections (6), whereas the other is based on inflammatory processes (7). this academic evidence now suggests that periodontitis leads to the entry of bacteria or their products into the circulatory system, which increases the host's inflammatory response through numerous pathways, favoring the formation and worsening of atheromatous lesions (8). monocyte chemoattractant protein-1 (mcp-1) is a strong factor for macrophage and monocyte chemotaxis, reflecting the very first identified. human cc chemokine with monocyte chemotactic functions (9). a number of various cells, such as epithelial, endothelial, smooth muscle, astrocytic, mesangial, microglial, monocytic, and fibroblastic cells producing mcp-1 following oxidative stress, particular cytokine or growth factor action which is either biologically derived or stimulated (9). the key role of mcp-1 is the regulation of monocytes, macrophages, natural killer (nk) cells, and memory t lymphocyte recruitment and aggregation (10). in atherosclerotic cvd, research findings have shown that mcp-1 promotes endothelial cell activity with chemokine receptors and enhances the vulnerability of plaques (11). furthermore; mcp-1 was shown to be selectively present at affected periodontal sites and displayed a distinct distribution pattern in the periodontium, as it is expressed in the inflammatory infiltrate along the basal layer of the oral epithelium and by endothelial cells, fibroblasts, and mononuclear phagocytes (12). material and methods study design eighty-eight subjects were selected according to inclusion and exclusion criteria in a period from march to july 2021. the study protocol was approved by the ethical committee of the college of the dentistry/university of baghdad follow the guidelines of helsinki and tokyo for humans (the reference no.249 in 18/2/2021). all the individuals were informed about the purpose of this investigation. informed consent was obtained from each participant, and a questionnaire was used to record the background information. subjects were divided into four main groups: •athero group, 25 patients with atherosclerotic cardiovascular disease (ascvd) who have had catheterization for less than one year and are taking anticoagulant medicines (plavix) and have stenosis of about fifty percent or more of at least one coronary artery and with healthy periodontium. • periodontitis group, 25 patients diagnosed to have periodontitis and didn’t have any systemic disease. a patient is a periodontitis case in the context of clinical care with interdental cal is detectable at ≥2 non-adjacent teeth, or buccal or oral cal ≥3 mm with pocketing >3 mm is detectable at ≥2 teeth (13). •athero+periodontitis group, 25 patients with both periodontitis and atherosclerosis, •control group, 13 subjects with clinically healthy periodontium and no systemic disease, in which bleeding on probing less than 10% and probing pocket depth of ≤ 3 mm (14). this group represents baseline data for the serum level of mcp-1. the exclusion criteria were: patients with a history of another chronic, systemic disease with a known link with periodontitis, such as diabetes mellitus, rheumatoid arthritis, and so on, medication (antiinflammatory or antibacterial medication) during the past three months and smokers, pregnancy, and contraceptive pills. j. bagh. coll. dent. vol. 34, no. 4. 2022 hamad and mahmood 11 examiner alignment for inter-examiner calibration, the periodontal parameters (bop, ppd, and cal) for 5 subjects were measured by the researcher and the supervisor at the same time. the measurements were assessed using interclass correlation coefficient (icc), and there was a good level of agreement for all parameters 0.785,0.760, and 0.753 respectively. for intra examiner calibration, the periodontal parameters (bop, ppd, and cal) for 5 subjects were measured twice by the researcher with a two-hour interval between the two measurements. there was a good level of agreement for bop and ppd, and excellent for cal (16). clinical assessment assessment of the periodontal status was carried out for all participants in which full mouth plaque score by o’leary (1972 ) is used to detect presence or absence of plaque at four surfaces of each tooth (buccal, palatal/lingual, mesial & distal) by using a disclosing agent (15), full mouth bleeding on probing score recorded as present (1) or absent (0), probing pocket depth and clinical attachment level were recorded using a periodontal probe of william’s (marking at 1,2,3,5,7,8,9 and 10 mm). ppd was measured from the gingival margin to the base of the pocket while cal is the distance measured from cemento-enamel junction to the base of the pocket/sulcus at six sites per tooth. mcp-1 measurement 5ml of venous blood was collected from each participant from the cubital fossa using 5ml plastic disposable syringe, then transferred into jell separating tubes, centrifuged for 5 minutes at (3000 rpm) and then sera were separated, then the tubes were labeled and stored at (-20°c) for later analysis by enzyme-linked immuno-sorbent assay (elisa) for the quantitative determination of serum mcp-1. statistical analysis data description, analysis, and presentation were performed using statistical package for social science (spss version 21) (chicago, usa, illinois). mean, and standard deviation (sd) for nominal variables, also inferential statistics as levene test, pearson correlation (r), interclass correlation coefficient (icc), two independent sample t-test, shapiro wilk and d'agostino pearson test for the normality distribution of the quantitative variables, and one way analysis of variance (anova) with games-howell posthoc test and tukey kramer hsd (according to levene's p-value) were used to analyze data. results all studied variables were found to be normally distributed (parametric data) using shapiro-wilk and d’agostino pearson at (p˃0.05). for pli analysis, the mean value of pli was found to be higher in athero+periodontitis group followed by periodontitis group then athero group, and lowest in the control group with a significant difference at p.value ˂0.05. while in bop it was found to be higher in periodontitis group, followed by athero+periodontitis group, then athero group, and also lowest in control group with a significant difference at p.value ˂0.05 table.1 levene statistics=1.904, p value=0.135 ns, * = significant at p<0.05. for pli levene statistics=15.375, p value=0.000 sig., *= significant at p<0.05.for bop following multiple pairwise comparisons (mpc), the only non-significant finding was found when comparing control group with athero group and periodontitis group with athero+periodontitis group while other results were significant, bop showed the same results table 2. for ppd and cal, athero+periodontitis group showed j. bagh. coll. dent. vol. 34, no. 4. 2022 hamad and mahmood 12 a higher mean value and sd than periodontitis group with a significant difference between them at p.value ˂0.05 as shown in table 3. table 1: statistical test of pli and bop among groups using one way anova. groups pli (mean±sd) of score 1 p-value bop (mean±sd) of score 1 p-value athero 25.080±8.411 0.000 sig 5.080±1.656 0.000 sig periodontitis 70.400±13.342 39.360±18.154 athero+periodontitis 70.640±11.139 35.440±15.594 control 24.538±13.956 5.154±2.853 table 2: inter groups multiple pairwise comparisons of the mean values of pli and bop. (a) groups (b) groups mean difference (a-b) of pli p-value mean difference (a-b) of bop p-value athero periodontitis -45.3200 0.000 * -34.2800 0.0000 * athero+periodontitis -45.5600 0.000 * -30.3600 0.0000 * control 0.5415 0.9991 ^ -0.0738 0.9998 ^ periodontitis athero+periodontitis -0.2400 0.9999 ^ 3.9200 0.8452 ^ control 45.8615 0.000 * 34.2062 0.0000* athero+periodontitis control 46.1015 0.000 * 30.2862 0.0000* *=significant at p<0.05, ^=not significant at p>0.05 table 3: a statistical test of ppd and cal among groups using independent sample ttest. variables periodontitis athero+periodontitis t-test p-value ppd (mean±sd) 4.759±0.727 5.169±0.583 2.202 0.032* sig cal (mean±sd) 3.459±1.033 4.649±0.999 4.143 0.000* sig *=significant at p˂0.05 primary outcomes the current study showed that mcp-1 was higher in athero+periodontitis group followed by athero group, and then periodontitis group, while lower in control group with a significant difference at p.value ˂0.05 table 4. after doing mpc the only non-significant result was found when comparing athero group with periodontitis group while other findings were significant as shown in table 5. concerning the correlation of mcp-1 and clinical periodontal parameters in the current study, there was a significant strong positive correlation with ppd (r=0.503; p=0.0104), and cal (r=0.501; p=0.0107) in periodontitis group and there was a significant strong positive correlation with cal (r=0.510; p=0.009) in athero+periodontitis group table 6. j. bagh. coll. dent. vol. 34, no. 4. 2022 hamad and mahmood 13 table 4: a statistical test of mcp-1 among groups using one way anova. groups mean ±sd p-value athero 83.857 33.742 0.000* sig periodontitis 82.433 26.499 athero+peridontitis 148.177 51.693 control 48.594 14.586 table 5: inter groups multiple pairwise comparisons of the mean values of mcp-1 multiple comparisons ( games-howell) dependent variable: mcp-1 (ng/l) (a) groups (b) groups mean difference (a-b) sig. athero periodontitis 1.4244 0.9983 ^ athero+periodontitis -64.3200 0.0000* control 35.2632 0.0004* periodontitis athero+periodontitis -65.7444 0.0000* control 33.8388 0.0001* athero+periodontitis control 99.5832 0.0000* levene statistics=3.730, p value=0.014 sig. *= significant at p<0.05 *=significant at p<0.05, ^=not significant at p>0.05 table 6: correlation between mcp-1 and periodontal parameters by each group.. mcp-1 (ng/ l) r p-value athero. pli 0.477 0.016 * bop 0.215 0.302 periodontitis pli 0.071 0.736 bop 0.079 0.709 ppd (mm) 0.503 0.0104* cal (mm) 0.501 0.0107* athero+periodontitis pli 0.291 0.158 bop 0.318 0.121 ppd (mm) 0.011 0.958 cal (mm) 0.510 0.009* control pli 0.175 0.569 bop -0.028 0.927 discussion the current study showed that the mean values of ppd and cal in athero+periodontitis group were greater than in periodontitis group with significant difference between them. these results agreed with other previous studies (17-20). this could be due to an increase in plaque and bacterial invasion with its toxin, which induces further damage of the alveolar bone tissue, sulcular and junctional epithelium, and other supporting tissue, ultimately increasing the supply of nutrients required for the multiplication of bacteria (21). in terms of increased periodontal damage when atherosclerosis is present, there are two possible explanations: either a direct effect of atherosclerosis on the immune system, resulting in the release of enzymes and pro-inflammatory cytokines such as il-1α, il-6, mmps, and tnf-α, or the effect of plaque accumulation. endothelial dysfunction has also been linked to more periodontal destruction (22). also, the increased loss of periodontal attachment may be due to the host immune responses to the presence of pathogens leading to collagen and bone destruction by the production of cytokines from cells such as pmns and monocytes that played an active role in inflammatory processes and were involved in numerous activities that would enhance the amount of damage. furthermore, the existence of atherosclerosis would result in a rise in cytokine release, greater damage, and hence an increase in cal levels (23). results as well showed that the mean value of serum mcp-1 was higher in athero+periodontitis group than in athero group, periodontitis group and the control group with highly significant difference between them this agreed with previous findings (21). regarding the increased level of mcp-1 with j. bagh. coll. dent. vol. 34, no. 4. 2022 hamad and mahmood 14 periodontitis, the possible explanation is that pathogens such as (p. gingivalis, fusobacterium nucleatum, aggregatibacter actinomycetemcomitans) may cause local production of mcp-1 by various cells at diseased periodontal sites, attracting circulating monocytes to the periodontal tissues, where they mature into macrophages upon exposure to various stimuli, including cytokines. macrophages are found in large numbers in inflamed gingival tissues in periodontal disease and are considered to have a key role in pathogen killing and the production of pro-inflammatory mediators and cytokines. in addition to that, il-1 and tnf-α, which are produced by macrophages, are known to cause bone resorption in addition to their pro-inflammatory characteristics (24). regarding the increased level of mcp-1 with atherosclerosis, the observed increase of mcp-1 protein levels in the circulation of individuals with atherosclerosis can be attributed to at least two processes.1st , it might be a direct result of the progression of atherosclerosis. endothelia and macrophage-like cells are the major sources of mcp-1, which are known to play a key role in the development of atherosclerosis and plaque formation. endothelial cells can generate mcp-1 in response to low-density lipoprotein (ldl), a key atherosclerotic trigger factor, according to in vitro studies (25, 26). 2nd, elevated mcp-1 levels may reflect the progression of the inflammatory response in the heart and brain. mcp-1 and macrophage inflammatory protein-1beta (mlp-lbeta) are two major chemokines that coordinate the infiltration of blood-derived monocytes and lymphocytes into the ischemic region, according to several research on animal models of stroke. in addition, a significant positive correlation was found with ppd and cal. our results were in agreement with (27-29), the possible explanation for these findings is that in periodontal disease, mcp1/ccl2 is thought to be the main chemoattractant for macrophages. macrophages are abundant in inflamed gingival tissues and are hypothesized to play a key role in pathogen killing as well as the release of pro-inflammatory mediators such tnf-, il-1, and nitric oxide (24, 30, 31). these mediators also promote the cellular immune response, which could help with periodontopathogen control. in contrast, macrophages produce inflammatory products that have been shown to promote osteoclast formation and maturation, which leads to bone resorption (31). as a result, the attraction of macrophages by mcp-1 may result in increased periodontal disease severity, a theory confirmed by data revealing that more macrophages were detected in active periodontitis sites. mcp1/ccl2 is also linked to osteoclast chemotaxis and differentiation, most likely due to its interaction with the ccr2 receptor (32, 33) conclusion according to the findings of this study the significant positive correlations between serum level of mcp-1 and clinical periodontal parameters (ppd and cal) in both periodontitis and athero+periodontitis group and assuming that serum mcp-1 level rise proportionally to the severity of periodontal disease, and suggesting that mcp-1 could be used as an inflammatory biomarker in periodontal disease. conflict of interest: none. references 1. peres ma, macpherson lm, weyant rj, daly b, venturelli r, mathur mr, et al. oral diseases: glob. public health. the lancet. 2019;394(10194):249-60. j. bagh. coll. dent. vol. 34, no. 4. 2022 hamad and 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authentic human osteoclasts differentiated with rankl and osteoclast like cells differentiated by mcp‐1 and rantes. j. cell. biochem. 2006;97(3):512-8. في مرضى التهاب دواعم االسنان و مرض التصلب العصيدي 1العنوان: تقييم مستويات مصل الدم للبروتين الجاذب ألحادي الخلية مها شكري محمود , صفا علي حمد الباحثون: : المستخلص وتنظيم بدء في مهما دوًرا يلعبو والبطانية، االلتهابية لخاليا ا بواسطة عنها التعبير يتم كيميائية مادة هو 1– الخلية ألحادي الجاذب البروتين الخلفية: مرتبط وكالهما األنسجة، وإصابة لاللتهابات المؤيدة للمنبهات استجابةً أيًضا تعبيره يرتفع اللثة. اللتهاب النشطة المواقع في االحادية الخاليا وتعبئة الجيوب عمق مؤشر وقيم التسبير عند النزف ومؤشر الجرثومية الصفيحة مؤشر مثل اللثوية السريرية المعلمات قياس األهداف:.الشرايين تصلب بآفات المرتبط، لألنزيم المناعية االمتصاصية المقايسة فحص باستخدام 1– الخلية ألحادي الجاذب للبروتين المصل مستويات قياس الرابطة، االنسجة وفقدان والضبط الدراسة مجموعات في 1– الخلية ألحادي الجاذب للبروتين المصل مستويات ومقارنة الضبط، ومجموعة الدراسة مجموعات من كل في 66 إلى 36 من أعماره تراوحت وإناثًا، ذكوًرا شخصا، 88 الدراسة هذه ضمت العمل: وطرق المواد األشخاص، اللثوية. السريرية بالمعلمات وربطها 25 تضم الثانية المجموعة سليمة، لثة مع العصيدي التصلب مرض لديهم شخصا 25 تضم األولى المجموعة مجموعات: أربع إلى تقسيمهم تم عاًما، تضم الرابعة والمجموعة المرضين كال لديهم شخصا 25 تضم الثالثة المجموعة جهازية، امراض أي وبدون االسنان دواعم التهاب مرض لديهم شخصا تم السريري، التقييم وبعد .للثة الصحية الحالة لتقييم اللثوية السريرية المعلمات استخدام تم مزمن. جهازي مرض أي وبدون سليمة لثة لديهم شخصا 13 المقايسة فحص باستخدام mcp-1 الخلية ألحادي الجاذب البروتين مستوى لقياس الدم مصل وفصل مشارك كل من الوريدي لدم ا من مل 5 سحب كان التسبير عند النزف ومؤشر الجرثومية الصفيحة مؤشر قيم فإن الدراسة، هذه لنتائج وفقًا النتائج:. elisaالمرتبط لألنزيم المناعية االمتصاصية في منها 3 المجموعة في أكبر الرابطة االنسجة وفقدان الجيوب عمق مؤشر قيم كانت المقابل. في .4و 1 المجموعة في منه 2و 3 مجموعة في أعلى يتعلق وفيما ، 4 و2 و 1 المجموعة في منه 3 المجموعة في أعلى الدم مصل في الخلية ألحادي الجاذب البروتين مستوى ان وجد كما ،2 المجموعة االنسجة وفقدان الجيوب عمق مؤشر قيم مع معنوي إيجابي ارتباط هناك كان 2 المجموعة في اللثوية. السريرية والمعلمات mcp -1 بين باالرتباطات الجاذب البروتين مستوى أن الدراسة هذه كشفت االستنتاج: الرابطة. االنسجة فقدان مؤشر مع معنوي إيجابي ارتباط هناك كان 3 المجموعة وفي الرابطة مستوى ارتفاع يرتبط قد لذلك، نتيجة والثانية. األولى المجموعة في منه ملحوظ بشكل أعلى كان الثالثة المجموعة في الدم مصل في الخلية ألحادي الشرايين. بتصلب اإلصابة خطر بزيادة االسنان دواعم بالتهاب المرتبط الخلية ألحادي الجاذب البروتين intisar .doc j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 40 the effect of the addition of silanated poly propylene fiber to polymethylmethacrylate denture base material on some of its mechanical properties intisar j. ismaeel, b.d.s., m.sc., ph.d. (1) hasanain k.a. alalwan, b.d.s., m.sc. (2)) mustafa m.j., b.d.s., m.sc. (2) abstract background: poly propylene fibers with and without silane treatment have been used to reinforce heat cure denture base acrylic but, some mechanical properties like transverse strength, impact strength, tensile strength, hardness, wear resistance and wettability. which are related to the clinical use of the prosthesis are not evaluated yet. the aim of the study is to identify the influence of incorporation of treated and untreated fibers on these properties materials and methods: eighty four heat cure acrylic specimens were constructed by conventional flasking technique. they were divided into six groups according to the tests and each group was subdivided into two subgroups control and experimental groups (seven samples for each subgroup).transversestrength and tensile strength test were performed using instron universal testing machine. the impact strength test was evaluated by the use of impact testing device. wear resistance was evaluated by pin on disk wear measurement method while, a digital microscope supplied with high resolution camera was utilized to measure the contact angle reflecting wettability grade. descriptive statistics and independent t test were used for statistical significance. results:the results revealed that the addition of silanated polypropylene fibers produced significant difference in transverse strength and highly significant difference in tensile strength, the impact strength,wettability value compared with the control group also the results showed that the hardness test was not significant and different control group . wear resistance was highly significant decreased in experimental groups conclusion: incorporation of silanated treated poly propylene fibers to heat cure poly methyl methacrylate resin was beneficial regarding the tested properties to improve the mechanical properties of the resin. key words: poly propylene fibers, transverse strength, impact strength, tensile strength, hardness, wear resistance, wettability. (j bagh coll dentistry 2015; 27(1):40-47). introduction developments in dentistry have largely been investigated as a result of scientific research. of particular note, are developments in the field of dental materials and a drive towards the practical dentistry. many aspects of prosthodontic treatment; clinical or laboratory based, may impact on overall patient satisfaction and the clinical success of treatment (1). denture base materials, especially the resin based poly (methymethacrylate) (pmma) materials are the most widely used non-metallic denture base materials (2). they do, however, have a number of well documented problems. since its introduction in 1937, poly (methyl methacrylate) (pmma) has become the most commonly used material for denture bases. it remains most popular of all the polymeric denture base materials. this is largely due to its favourable, although not ideal, characteristics (3). (1)assistant professor. department of prosthodontics, college of dentistry, university of baghdad. (2)assistant lecturer. department of prosthodontics, college of dentistry, university of baghdad. since pmma was introduced, most dental material research has been focused upon developing materials with higher strength, lower levels of residual methacrylate monomer after processing, improved dimensional stability, increased radiopacity and improved resistance to candidal infiltration (4). there are three potential avenues for investigation which have been studied in the field of denture base materials. these are: the development of a new alternative to pmma, the chemical alteration of pmma; or the reinforcement of pmma with another material such as fibres of with more favourable fracture resistance properties (5,6) . acrylic resin dentures are susceptible to fracture during wear or if dropped, fractures in dentures occur principally due to two different types of forces, flexural fatigue or impact (5). flexural fatigue results from repeated application of a force. numerous techniques for reinforcement of pmma with inclusion of other materials have been described (7,8). carbon and kevlar fibre reinforcement techniques have also been investigated. these were found to be not satisfactory aesthetically. however the complicated etching process required to improve their incorporation into pmma, and preparation j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 41 and positioning of the fibre layers, was found to be both time consuming and technique sensitive (9). such factors have thereby, reduced the routine applicability of this method. the use of glass fibres to reinforce pmma is probably the most common technique described in the literature (9-11), not only have these been found to improve the mechanical properties of pmma, but they are also highly publishable, aesthetic and easy to manipulate (5,11). the addition of treated and untreated silica to pmma was investigated by mcnally et al.2006 silica is commonly used as a filler to improve strength and wear characteristics of dental materials. the data collected in the study did not support the hypothesis that silica would improve the material’s impact or transverse strength. therefore, the authors were unable to recommend the inclusion of silica fillers in pmma materials (12). notable efforts have been conducted to solve this problem and to strengthen the dental polymer by incorporating various types of fibers (10, 13, 39–43) and fillers (19,24, 44–46), but it has not been solved (13). interfacial phase and coupling agents for a composite to have effective clinical performance, a good bond must form between the inorganic filler particles and the organic resin matrix during setting. this phenomenon is achieved through the use of coupling agents, such as silane (14). this interfacial bonding is important to transfer load from the polymer matrix to the reinforcing fillers. the most common types of coupling agents are organ of unctionalsilanes and organotitanates, which are used to improve filler dispersion in matrix, prevent aggregation, and reinforce the interfacial coherence with resin (15). silane-coupling agents silanes are commonly used in dentistry in different applications to provide the opportunity for chemical bonding. the silane can function as mediators between dispersed and organic phases. the most common silane, 3-methacryloyloxypropyltrimethoxysilane (mps, or 3-mps (15) ,which chemically bond the silica, present in silica-based fillers such as porcelain, quartz, pyrogenic silicon dioxide, and silicate glasses because of the similarity in their ordered structure (16), to the organic matrix of resin by means of siloxane bonds and hydrogen bond (17). most recent investigations give increasing prominence to transverse strength, impact strength, tensile strength and hardness as these properties give an idea about the resistance of the material during use, in order to develop strong denture base material (17). wear resulted from removal and relocation of materials via the contact of two or more materials which cause the material to be loss. wear resistance is deemed as one of the characteristics that be developed by composite (18). denture base material wettability play an effective role in denture retention, complete wetting of denture surface increase the capillary force therefore, raising denture retention in static and dynamic situations (18). in this study the attempt has been done to incorporate silanated polypropylene fibers to reinforce polymethyl methacrylate denture base material and examine the effect of this addition to some mechanical properties, which are: transverse strength, impact strength, tensile strength, hardness, wear resistance and wettability which are related to the clinical use of the prosthesis. materials and methods eighty four acrylic specimens were constructed from heat cure acrylic resin by conventional technique for flasking and curing using heat cure acrylic resin. they were divided into six groups according to the tests and each group was subdivided into two subgroups (control and experimental groups, seven samples for each subgroup). the required amount of the powder of the polymer and polypropylene fibers was used by weighting using digital electronic balance 2.5 %( by weight 6mm length) poly propylene fibers (pp fibers) (cracecemfiber®) as more recent study showed an incorporation of 2.5% percentage had the best effect regarding impact and transverse strengths as that considered to be important in measuring the strength of materials (19). polypropelene fibers were treated with 3(methacryloyloxy)propyltrimethoxysilane (mps) to improve the bonding between pp fibers and pmma matrix to get pmma/pp fibers composite with improved properties over pure pmma . one hundred milliliter of ethanol aqueous solution (70 vol%) was prepared using 99.8 vol% ethanol and deionized water, and adjusted to ph of 4.5 by titrating with 99.9% acetic acid using a ph meter. then, 5wt%, g of mps was added respectively into ethanol aqueous solution, and stirred. this mps solution was stored in a 100 ml polyethylene cup with a cover, and allowed 5 min for hydrolysis and silanol formation. then, 100 g pp fibers were added into mps solution. the mixture was stirred with magnetic stirrer for 30 j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 42 minutes, then the mixture was sonicated with probsonication apparatus for 30 minutes, then the solution left dried at room temperature for 14 days (20). the (ftir) spectrophotometer where done to determine whether or not functional group of the mps have been attached to pp fibres by analyzing characteristic vibrations of functional groups (21) . when there was change in the vibration or absorption of functional group indicated to be used to complete the study,change which has been occurred indicated by the ftir spectra as shown in figure 1and 2. after silanization of pp fibers, the selection of the percentage of the fiber has been done. 2.5% were used as percentages of fiber to be added to the pmma according to previous study (19), mixing of polymer powder and fibers was done by using mortar and pestle to attained homogenous mixture for about 3.0 minutes, all the specimens for all the six tests were finished and polished. the addition of silanated pp fiber to the pmma was done only to the experimental groups fig. 1: ftir of polypropylene fiber without silanation fig. 2: ftir of silanated polypropylene fiber the tests used in this study were: atransverse strength test specimens were prepared with dimensions (65mm x 10mm x 2.5 + 0.1mm). all the specimens were stored in distilled water at 37 0oc for 48 hours before performing the test (22). the test was performed using instron universal testing machine (wdw-200 e), each specimen was positioned on the bending fixture which consist of two parallel supports (50 mm apart), the full scale was 50 kilo and the load was applied with across head speed of1mm/min until fracture occurs. bimpact strength test specimens have dimension of (80mm x 10mm x 4mm) (iso 179, 2000) for unnotched specimens. specimens were stored in distilled water at 370c for 48 hours before being tested (22). the impact strength test was evaluated following the procedure recommended by the iso 179 with impact testing device. by supporting the specimen horizontally at each end and struck by free swinging pendulum of 2 joules. the scale readings give the impact energy in joules. the charpy impact strength of unnotched specimens was calculated in kilo joules per square meter by the following equation: impact strength =e/bd x103 (iso, 2000) e: the impact energy in joules b: is the width of the specimens in millimeters d: is the depth of the specimens in millimeters ctensile strength test dumbbell shaped specimens were fabricated according to astm specification d638m(1986).conditioning of the specimen was done by storing them in distilled water for two days at room temperature25ºc±2before testing according to ada specifications. the testing procedure was accomplished using instron universal testing machine (laryee, make test easy, china) with crosshead speed 1 mm/min and maximum loading of 20 kg. tensile strength calculations was performed are automatically done by the program of the testing machine software. d-surface hardness test specimens were prepared with a dimension of (65mm x 10mm x 2.5 + 0.1mm). all specimens were stored in distilled water at 370c for 48 hours before being tested (22). (shore d) durometer hardness tester surface hardness were used for measuring the hardness which is suitable for acrylic resin material. it consists of spring – loaded indenter (0.8mm in j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 43 diameter), that attached to digital scale scored from 0 to 100 units. three readings were done on each specimen (one in the center and other at each end) then the mean of three readings was calculated. ewear rate test special device was used to test the wear that was designed at university of technology material, engineering department, resistance laboratory-iraq. called pin on disk wear testing device ,it was recognized with high accuracy of results (23,24), the specimens were cylindrical in shape with dimensions of 20mm length and 10mm diameter according to the device requirement(figure 3). it consisted of pin which was the held specimen and disk made from stainless steel wheel which revolve 950 r/min, the specimen was weighed before and after the testing procedure, after that the specimen was secured to the holder and was put 10n load on the horizontal arm, the device switched on for 10 minutes (wear testing time)(25). the distance between the center of the disk and center of the specimen was 65mm. the following equation to was used determine the wear resistance: wear resistance (grm/mm) =change in weight/slide distance (slide distance=2π×radius distance between centers of disk and specimen×number of cycles ×time of test)(25). cleaning of the disk must be done after each test all specimens were immersed in distilled water for 48 hours before testing.as shown in figure 3. fwettability measurement of the contact angle was necessary to determine the wettability; the angle was between the base of the sessile drop and the tangent line contacting the solid, liquid and air simultaneously. dispersing of distilled water 10µl at the center of the fabricated sample using pipette. the sample dimensions was 8×30×2mm width, length and thickness respectively (26).static sessile drop method was utilized in this study. as the water dispersed, wait for 5 minutes to allow the drop to be in status of equilibrium. measurement of the contact angle was accomplished employing a digital microscope (dino-lite digital microscope pro -taiwan) at magnification 45× supplied with camera (high resolution 1024×768 pixel) and software (dino capture2.0 version 1.3.3.) granted a complete and precision analysis to the contact angle(27) (figure 4). statistical analysis the data collected of the tested specimens were translated to computerized statistical analysis system by using (spss) statistical package for social sciences version 20. descriptive statistics and independent t test where used for statistical significance. results characterization of silanized pp fiber the absorption bands of mps can be assigned to the presence of the functional groups, which are two prominent peaks at 2945cm-1 and 2841cm-1 which can be attributed to the (c-h) stretching, and the characteristic (c=o) stretching occurs at 1720cm-1, and the characteristic for (c=c) stretching occurs at 1637cm-1 for (chr2r andchr3r) occurs at 1413cm-1,and groups of peaks between 1296cm-1 and 1166cm-1can be attributed (c-o-c) stretching, the characteristic (si-o-chr3r) stretching occurs between (400 470)cm-1figure (1,2) . the descriptive statistics which include means, standard deviations, standard error of mean value, of the tests which are conducted to evaluate the effect of silanizedpp fibers addition on some properties of pmma are shown in table 1. by using independent samples t-test, the results revealed statistically significant difference between flexural strength of fiber reinforced pmma and the control resin group. fig. 3: pin on disk with the specimen fig. 4: digital microscope with specimen. j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 44 table 1: statistical analysis between control and experimental groups for all the tests tests performed studied groups descriptive statistics comparison n mean s.d. s.e. t-test df p-value transverse strength control 7 86.9187 7.2264 2.7313 2.632 12 .022 silanated pp fiber 2.5% 7 76.5621 7.4945 2.8327 impact strength control 7 12.2601 1.0234 .3868 -6.352 12 .000 silanatedpp fiber 2.5% 7 23.1549 4.4210 1.6710 tensile strength control 7 54.2143 1.5126 .5717 -3.421 12 .005 silanatedpp fiber 2.5% 7 57.1286 1.6710 .6316 hardness control 7 83.0000 .9018 .3409 .499 12 .627 silanated pp fiber 2.5% 7 82.7143 1.2158 .4595 wear rate control 7 .000012.000001.000000 3.795 12 .003 silanated pp fiber 2.5% 7 .000010.000001.000000 wettability control 7 45.8739 1.6865 .6374 21.015 12 .000 silanated pp fiber 2.5% 7 28.2646 1.4391 .5439 the addition of 2.5% silanized pp fiber lead to decrease in the mean value of transverse strength from (86.9187 mpa)to (76.5621 mpa) and when applying t. test the results revealed a significance difference p= 0.022 as shown in table 1 and the mean in figure 5. the impact strength test results showed a highly significant difference, between the control which has been found (12.2601 kj/m2) mean value, with the silanated pp fiber group which had (23.1549 kj/m2) mean value,p 0.000.as seen in table 1.fig 6,7. the tensile test revealed highly significant difference between the control (54.2143 mpa) and the silanated pp fiber group (57.1286 mpa), p= .005,as shown in (table 1. and figure 7.) no significant difference was found in the hardness test, decreased wear rate from (.000012 to 0.000010 gm/mm) and decreased wettability after addition of ppfiber 2.5 %, as shown in table 1 and figure 8. fig. 5: bar chart for the mean value of transverse strength of the control and ppf groups reinforced pmma fig.6: graph showing mean impact strength of control and ppfiberreinforced polymethyl methacrylate j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 45 discussion the use of fibers to reinforce denture base material has an acceptable success rate mainly because of the advancements in the fiberreinforcing materials. reinforcement with fibers enhances the mechanical strength characteristics such as transverse strength, ultimate tensile strength, and impact strength (9). in this study, using a type of olefin fibers named polypropylene (pp) as reinforcing filler to pmma denture base resin has many properties like high strength, good surface finish and polish, low cost and excellent biocompatibility (28). however, these fibers breakup the homogenous matrix of acrylic resin due to poor interface between fiber and resin affecting the mechanical properties. in order to avoid this, the polypropylene fiber surface energy increased by chemical or plasma treatment (29), surface chemistry and topography may be influenced to result in improved adhesion between the polymer matrix and fibers used. plasma treated polypropylene fiber had been used (19) , which results in improvement in the mechanical properties, but in this study the attempt has been done to use chemical surface treatment for the fibers, by treated with 3-(methacryloyloxy) propyltrimethoxysilane (mps) to improve bonding between pp and pmma matrix. the results revealed that the addition of silanated polypropylene fibers produced significant difference decrease in transverse strength mean value compared with the control group, this may be related to the fact that the random orientation of fibers allows only small portion of the reinforcement to be directed perpendicular to the applied stress. also this may be due to the internal voids formed in the resin fiber composite caused by poor wetting of fibers with resin (perhaps the using fibers not undergo changes from silane treatment), these voids were oxygen reserves that allowed oxygen to inhibit radical polymerization of the acrylic resin inside composite, this can lead to higher residual monomer content and affect strength, these results were with no agreement with result of waffae(19) who found increase in transverse strength after addition of plasma treated pp fiber but was not significant. highly significant increase in impact strength mean value (23.1549 kj/m2)compared with control group, this increase which could be related to the presence of silanated pp fibers which prevent the crack propagation and change in direction of cracks resulting in smaller flows between the fibers, these results are in agreement with results obtained by waffae,2013 and mowade et al 2012., this increase could be attributed to the fact that silane introduce functional groups on the surface of fibers there by making the surface polar, which improve the surface energy of the fiber and its compatibility with other materials therefore, enhance the impact strength. the results also revealed highly significant difference in tensile test, for the 2.5 wt% silanated pp fibers group, these are unlike the study done by alalwan (27) who used 2.5 wt% pp fibers plasma treated and found negative effect of plasma treatment to pp on the tensile strength, it could be inferred to the water absorption of pp fibers which was improved by plasma treatment, while silanated pp fiber may show reduced water absorption. because the functional group which fig. 7: graph showing means tensile strength of control and fiber-reinforced pmma fig. 8: graph showing mean wear rate test of control and pp fiber-reinforced polymethyl methacrylate j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 46 cause stretching not include polar group-oh, many, studies reported that incorporation of oxygen plasma treated poly propylene fibers to pmma had increased the water absorption significantly (19) and pmma tensile strength is negatively affected by water absorption and ambient moisture, this is in agreement with ishiyama et al (30), in addition to the acrylic used in this study was of cross linked type that might exaggerate the water absorption (31), in addition to that the orientation of the fibers and the bonding with the matrix of pmma affect the mechanical properties. plasma treatment for fibers can lessen the tensile strength of the fibers themselves due to their loss of weight and diameter reduction (32), this is not present with silanation,in contrast , there is addition of layer to the fibers. in this study there was slight decrease in the hardness number which statistically not significant, this decrease could be related to no presence of these fibers near or at the surface of the composite which extremely hard and stiff (33,34) . highly significant (p=0.003) decrease in the wear rate could be attributed to that high abrasion resistance of pp fiber(35) ;however, after silane treatment it significantly improved in comparison to control group and this may be attributed to formation of functional groups on the pendant methyl group of the isotactic pp fiber leading to increased cross linking that decreased plastic flow which in turn increased the wear resistance and that was consistent with kyomoto et al2007 and drobny2013(36,37). wettability of acrylic reinforced with silanated treated pp fiber was highly significant, regarding the treated pp, it might be pp fibers used are insoluble in water and could reduce the overall volume of the absorbing polymer (38). the second factor could be the silane coupling agent which was used to silanization of pp fibers the silane coupling agent had similar chemical nature to polymer matrix (methacrylate at one side). thus, the pp fibers-resin interface provided by silane coupling agent could lead to a reduction in the amount of water that reached to the inner layers of the polymer matrix.this is in agreement with several researchers (39,40), that overwhelmed on pmma-pp fiber composite wettability and occurrence of new functional groups as noticed guiding the change in a surface layer structure. references 1. beth gy, allen sm, harrison a. an 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(ivsl). الخالصة لكن لحد االن لم یختبر تاثیرھا على لقاعدة الطقم قد استخدمت في تقویة الراتنج االكریلي الحراري بالسیالنحدیثا الیاف البولي بروبیلین مع و بدون معالجة :الخلفیة .طب ومقاومة البلىرقوة الشد وقابلیة الت ئیسة تحوي مجموعتان ریة ومقسمة على ستة مجامیع ولكل مجموعة رارة الحریقة البلمرت بطرمبع وثمانونعینھ استخدمت في البحث بلرا:المواد و االسالیب عن طریق استخدام جھاز اختبار البلى ، تم تقییم مقاومةونرباستخدام شھاز االنستضةرالمستعقوة االختبار الشد واقوة اختباز أجریتعیة سبع عینات لكل منھا رف مع السطح عالیة الدقة لقیاس زاویة االتصال قمیةراریكامواستخدمت لقیاس قوة الصالدة رامیتراستخدم جھاز الدییوقیاس الوقت، ورصبطریقة المسمار على الق . صفة الترطیبلقیاس قابلیة المعالجة البولي بروبیلینلیاف لصالح اضافة اصفة الترطیبقابلیة قوة الصالدةوضةورالمستعقوة االختبار وااظھرت النتائج تباینا واضحا عند فحص قوة الشد:النتائج .صالبة السطح یخص ق فیمارفي ما یخص صفة مقاومة البلى وال یوجد فلاللیاف المعالجة ایجابيبینما بینت تاثیر بالسیالن . وسةالیاف البولي بروبیلین المعالجة اثر ایجابیا بالصفات المدرث یستنتج بأن اضافة مع محدودیة البح:االستنتاج http://journals.cambridge.org/action/displaya http://textilelearner.blogspot.com/2013/01/polyp widad f.doc j bagh college dentistry vol. 25(3), september 2013 clinical evaluations restorative dentistry 57 clinical evaluations for the masticatory efficiency of heat cure resin and flexible types of denture base materials zainab m. j. al-jammali, b.d.s. (1) widad abdul-hadi al nakkash, b.d.s., h.d.d., m.sc. (2) abstract background: the aim of this study was for estimation and comparism of masticatory efficiency in patient wearing heat cured acrylic and flexible base partial denture, finding out the role of peanuts and carrots on the measurement of chewing efficiency, and to find out whether the types of p.d. (being single or two opposing each other) has any effect on the masticatory performance. materials and methods: twenty partially edentulous patients were selected. five of these patients were selected having kennedy class i with no modification against natural dentition, other 5patients having cl.i against cl.i . the other 5 patients having cl.iii against natural dentition and the last 5 patients were with cl.iii against cl.iii. several ways were used for measuring masticatory efficiency including: number of chewing strokes, number of swallows, the mastication time, and measure the masticatory performance by sieving method. differences between the means of the four groups were analyzed with t-test. results: the differences between the two denture base types in total number of strokes was significant at (p<0.001) in study group (2,3,4), the study group (4)have the highest mean value of the total number of strokes for acrylic denture during chewing carrots food types(47.6)strokes. the highest mean value of the total chewing time is for the fourth group with the acrylic denture during chewing carrots (35.2 sec.), and the highest masticatory performance index was for the flexible denture in all study groups during chewing the two tested food. conclusion: the flexible partial denture provide better chewing efficiency than heat cure acrylic partial denture, the masticatory performance was higher for flexible partial denture than heat cure acrylic partial denture, there was significant differences between carrots and peanuts in both flexible and heat cure acrylic partial denture, and patient with single denture show better chewing efficiency than patient with paired denture. key words: heat cure acrylic partial denture, flexiblepartial denture, masticatory performance, and masticatory efficiency. (j bagh coll dentistry 2013; 25(3):57-61). introduction chewing is the primary function of teeth and dentistry is the science that is responsible for returning structural integrity not only of the teeth, but the stomatognathic system in general. however if all missing teeth have been replaced, the masticatory function is usually improved but to a lesser extent than that of previous natural dentition. favorable denture base material is needed for fabricating long lasting and biologically acceptable dentures. acrylic "poly methyl methacrylate"(pmma) is one of the most widely used denture base material with numerous advantages (1),but pmma has poor mechanical properties like fracture (2), allergic reactions to pmma are also reported (3). the flexible denture base was introduced in order to improve both the aesthetic and functional limitations of conventional rpd (4). materials and methods twenty partially edentulous patients were be selected (10 male and 10 female) attending the removable prosthodontics clinic, at babylon dental university. (1) master student. department of prosthodontics, college of dentistry, baghdad university. (2) professor. department of prosthodontics, college of dentistry, baghdad university. five of these patients were selected having a maxillary or mandibular partially posterior edentulous area kennedy class i with no modification against natural dentition with no complaint of pain or discomfort at the time of study ,other five patients having cl.i against cl.i. the other five patients having cl.iii including missing (3 or 4 posterior teeth) against natural dentition and the last five patients were with cl.iii against cl.iii kennedy classification. two types of food were employed for the measurement of chewing efficiency which are peanuts and carrots. peanut was characterized as a soft food(5) and raw carrot was considered to be one of the hardest foods(6). both are inexpensive, uniform and most people like them as test material. raw carrots containing both inner core and outer portion was prepared by boring machine to obtain standardized square form with 1 cm² then cut by using a sharp knife and millimeter ruler to get cube piece(1cm³) . in this study several ways were used for masticatory efficiency including: 1. number of chewing strokes performed up to the first swallow. 2. number of chewing strokes until the mouth is empty. 3. number of swallows till the mouth is empty. 4. the time (seconds) elapsed until the first swallow. j bagh college dentistry vol. 25(3), september 2013 clinical evaluations restorative dentistry 58 5. the time (seconds)elapsed until the mouth was free of food . then measure the masticatory performance was evaluated by measuring the particle size by sieving method as follow: a. the subject was instructed to chew a carrots (3g) then peanuts(3g) , to a prefixed numbers of strokes (15 strokes) of mastication on the artificial teeth. b. spit the chewed sample (chewed test portions) in a container. c. the subject was asked to rinse with water and make a new expectoration of waste. d. intraoral inspection to verify the absence of waste. e. the particles were washed and left to dry by air in a container. f. recording the weight of the particles. g. vibration analysis through sieves of 4 mm ,2.5 mm and 1.5 mm opening for 120 sec. . h. the weight of particles retained on each sieve was recorded. i. application of masticatory performance index: r = 100 [1 (x + y) / (2t-x)] r = percentage of masticatory performance. x = weight in grams of material in the coarse fraction. y = weight in grams of material in the middle fraction. t = total weight in grams of the test portion after chewing. the sum of the weight in grams of the chewed material accumulated on the sieve with aperture of 4 mm was referred to as the coarsest fraction (x). the sum of the weight in grams of the chewed material accumulated on the sieve with aperture of 2.5 and 1.5 mm was combined and was referred to as the medium fraction (y). (t) was the total weight in grams of the test portion after mastication(7,8). results the flexible partial denture performed the chewing of the carrots raw to the first swallowing threshold with the least number of strokes than the acrylic denture and the carrots required more strokes than peanuts, also the patients in group (4) registered the largest number of strokes to the first swallow(25) than the other groups, and the effect of paired denture compared to single denture among class-iii is significantly increasing the number of strokes to first swallowing by 5 strokes in flexible and 4.6 strokes for acrylic dentures. among the fourth study group (class-i against class-i) having flexible partial denture significantly reduce the total number of chewing strokes to mouth empty by 14.4 strokes compared to acrylic denture, the percentage of change for flexible denture in reduction the number of strokes by 30.2% of acrylic denture strokes during chewing carrots .there is no differences in number of swallows till mouth empty between the two denture base materials during chewing carrots, with little but not significant differences in group (2) during chewing peanuts. the differences in chewing time between the two different denture base materials was highly significant at (p<0.001) in groups (1,2,4) during chewing carrots and in group (4) only during chewing peanuts. the total chewing timewas higher for the heat cured acrylic partial denture for both types of food compared to flexible partial denture.the highest masticatory performance index was for the flexible denture in all study groups during chewing the two tested food. using carrots as the test food significantly decrease the masticatory performance index by 10.5% compared to using peanuts as a test food. discussion the flexible denture wearer had the lowest number of chewing strokes and the shortest mastication times, figures (1 and 2) during chewing the two food types and the least number of swallows compared with acrylic denture wearer. the highest masticatory performance index was for the flexible denture wearers, tables (1 and 2) that means it provided the largest weight of fine particles of the chewed food with both carrots and peanuts ,and consequently the most efficient mastication, the probable explanation is that because the flexible denture has the flexibility to disengage forces on individual teeth and prevent transfer of forces to remaining natural teeth and the other side of the arch because it acts as stress-breaker to disengage forces on individual saddles, thus shifting the burden of force control from the design features of the appliance to the material properties of the base material, where flexible lever does not work well as a lever. so let’s make the partial flexible to reduce the leverage effects of its extensions (9). when comparing single dentures with paired dentures ,we can notice that single denture (partial denture against natural dentition) was more efficient in all scales of measurements than paired denture and the probable explanation is that with single denture the food will be crushed between natural dentition and artificial teeth, in the presence physiological human factors influence such as the bite force and the oral sensorimotor of the natural dentition(10),the bite force was greater j bagh college dentistry vol. 25(3), september 2013 clinical evaluations restorative dentistry 59 in natural dentition than artificial teeth that will facilitate better food breakage and so better masticatory performance (11). -10 -5 0 5 10 15 20 25 30 35 40 study group class-iii against natural teeth class-iii against class-iii class-i against natural teeth class-i against class-i flexible partial denture acrylic partial denture difference between flexible and acrylic figure 1. bar chart of the mean time interval to mouth emptying (seconds) for flexible denture, acrylic denture and for the differences between flexible and acrylic in 4 study group(carrots). -10 -5 0 5 10 15 20 25 time interval to mouth emptyong (seconds)-flexible partial denture -peanutstime interval to mouth emptyong (seconds)-acrylic partial denture -peanutstime interval to mouth emptyong (seconds)-difference between flexible and acrylic-peanuts study group class-iii against natural teeth class-iii against class-iii class-i against natural teeth class-i against class-i flexible partial denture acrylic partial denture difference between flexible and acrylic figure 2. bar chart ofthe mean time interval to mouth emptying (seconds) for flexible denture, acrylic denture and for the differences between flexible and acrylic in 4 study group (peanuts). references 1. anusavice kj. phillips science of dental materials. 11th ed. st. louis: saunders company; 2003. p. 14370, 721-56. 2. yazdanie n, mahood m. carbon fiber acrylic resin composite: an investigation of transverse strength. j prosthet dent1985; 54(4): 543-7. 3. mabraden jk. some aspects of the chemistry and physic of dental resins adv dent res 1988; 2(1): 93-7. 4. lowe lg. flexible denture flanges for patients exhibiting undercut tuberosities and reduced width of the buccal vestibule: a clinical report. j prosthet dent 2004; 92(2):128-31. 5. manly rs, braley lc. masticatory performance and efficiency j dent res 1950; 29: 448-62. 6. kayser af, hoeven js. colorimetric determination of masticatory performance. j oral rehabil 1977; 4: 1458. 7. cho ll, kim kn, chang it, heo sj. a study on the effects of chewing patterns to occlusal contact points and chewing efficiency. j korean acad craniomandib disord 1994; 6: 125–35. 8. edlund j, lamm cj. masticatory efficiency. j oral rehabil 1980; 7(2): 123-30. 9. warriener g.2010.internet. 10. hirano k, hirano s, hayakawa i. the role of oral sensorimotor function in masticatory ability. j oral rehabil 2004; 31: 199-205. 11. fontijn-tekamp fa, slagter ap, van der bilt a, ‘t hof ma, witter dj, kalk w & jansen ja. biting and chewing in overdentures, full dentures, and natural dentitions. j dent res 2000; 79(7): 1519-24. j bagh college dentistry vol. 25(3), september 2013 clinical evaluations restorative dentistry 60 table 1. the difference in mean masticatory performance index between 4 study group in flexible denture, acrylic denture and differences between flexible and acrylic (carrots) masticatory performance index flexible partial denture acrylic partial denture difference between flexible and acrylic percent change for flexible compared to acrylic p (paired t-test) class-iii against natural teeth range (74 to 77) (48 to 55) (20 to 27) (36.4 to 56.3) mean 75.6 51.6 24 46.9 <0.001 sd 1.3 2.7 3.3 8.7 se 0.6 1.21 1.48 3.89 n 5 5 5 5 class-iii against class-iii range (34 to 38) (29 to 32) (4 to 9) (12.5 to 31) mean 35.4 30.2 5.2 17.4 0.006 sd 1.7 1.1 2.2 7.8 se 0.75 0.49 0.97 3.49 n 5 5 5 5 class-i against natural teeth range (42 to 46) (34 to 39) (3 to 11) (7.7 to 32.4) mean 43.4 36.6 6.8 18.9 0.009 sd 1.9 1.8 3.2 9.6 se 0.87 0.81 1.43 4.3 n 5 5 5 5 class-i against class-i range (29 to 33) (21 to 23) (6 to 12) (26.1 to 57.1) mean 31.8 22.2 9.6 43.6 <0.001 sd 1.8 1.1 2.2 11.3 se 0.8 0.49 0.98 5.03 n 5 5 5 5 class-iii-effect of paired denture compared to single denture (against natural teeth) difference in mean -40.2 -21.4 p <0.001 <0.001 class-i-effect of paired denture compared to single denture (against natural teeth) difference in mean -11.6 -14.4 p <0.001 <0.001 single denture-effect of class-iii compared to class-i difference in mean 32.2 15 p <0.001 <0.001 paired denture-effect of class-iii compared to class-i difference in mean 3.6 8 p 0.011 <0.001 j bagh college dentistry vol. 25(3), september 2013 clinical evaluations restorative dentistry 61 table 2. the difference in mean masticatory performance index between 4 study group in flexible denture, acrylic denture and differences between flexible and acrylic (peanuts) masticatory performance index flexible partial denture acrylic partial denture difference between flexible and acrylic percent change for flexible compared to acrylic p (paired t-test) class-iii against natural teeth range (84 to 87) (70 to 74) (12 to 16) (16.2 to 22.9) mean 85.8 72.4 13.4 18.6 <0.001 sd 1.1 1.7 1.9 3.1 se 0.49 0.75 0.87 1.38 n 5 5 5 5 class-iii against class-iii range (38 to 42) (34 to 35) (4 to 7) (11.4 to 20) mean 39.6 34.4 5.2 15.1 <0.001 sd 1.5 0.5 1.3 3.7 se 0.68 0.24 0.58 1.66 n 5 5 5 5 class-i against natural teeth range (60 to 65) (50 to 55) (7 to 15) (12.7 to 30) mean 62.4 52.2 10.2 19.7 0.003 sd 1.8 1.9 3.4 7.3 se 0.81 0.86 1.53 3.25 n 5 5 5 5 class-i against class-i range (34 to 37) (27 to 31) (4 to 9) (13.3 to 33.3) mean 35.4 28.8 6.6 23.3 0.002 sd 1.1 1.8 1.9 8.1 se 0.51 0.8 0.87 3.62 n 5 5 5 5 class-iii-effect of paired denture compared to single denture (against natural teeth) difference in mean -46.2 -38 p <0.001 <0.001 class-i-effect of paired denture compared to single denture (against natural teeth) difference in mean -27 -23.4 p <0.001 <0.001 single denture-effect of class-iii compared to class-i difference in mean 23.4 20.2 p <0.001 <0.001 paired denture-effect of class-iii compared to class-i difference in mean 4.2 5.6 p 0.001 <0.001 ali f.doc j bagh college dentistry vol. 28(2), june 2016 photodynamic therapy oral and maxillofacial surgery and periodontics 69 photodynamic therapy and periodontology ali jawad mohammed ali, b.d.s. (1) saif sehaam saliem, b.d.s., m.sc. (2) abstract this review highlights the importance of photodynamic therapy in periodontology. it can be confirmed that the photodynamic therapy as adjunct to classical scaling and root planing can be recommended as treatment option, which can by no means replace the classical therapy concepts. but even over an observation period of six months a slightly higher improvement of the clinical parameters was achieved than with srp alone. (j bagh coll dentistry 2016; 28(2):69-72). introduction periodontal disease caused by dental plaque is characterized by the clinical signs of inflammation and loss of periodontal tissue support. the mechanical removal of this biofilm and adjunctive been the conventional methods of periodontal therapy (1). but the removal of plaque and the reduction in the number of infectious organisms can be impaired in sites with difficult access. the possibility of development of resistance to antibiotics by the target organism has led to the development of a new antimicrobial concept with fewer complications. photodynamic therapy (pdt) involves the use of low power lasers with appropriate wavelength to kill micro organisms treated with a photosensitizer drug (2). pdt could be useful adjunct to mechanical, as well as antibiotics in eliminating periopathogenic bacteria. medical applications of (pdt) include treatment of cancer, psoriasis, actinic keratosis, rheumatoid arthritis, age related macular degeneration(3). broadly, it represents an alternative antibacterial, antifungal, and antiviral approach for drug-resistant organisms including bacteria that grow in the biofilm. photodynamic therapy (pdt) has emerged in recent years as a noninvasive therapeutic modality for the treatment of various infections by bacteria, fungi, and viruses (4). photodynamic therapy is defined as an oxygen-dependent photochemical reaction that occurs upon light–mediated activation of a photosensitizing compound leading to the generation of cytotoxic reactive oxygen species; predominantly singlet oxygen(5). it also minimizes the occurrence of bacterial resistance. photodynamic antimicrobial chemotherapy represents an alternate antibacterial, antifungal, (1) high diploma student. department of periodontics. college of dentistry. university of baghdad. (2)assistant professor. department of periodontics. college of dentistry. university of baghdad. and antiviral treatment against drug-resistant organisms photo-sensitizer are activated by red light between 630 and 700 nm corresponding to a light penetration depth from 0.5 cm (at 630 nm) to 1.5 cm at (700 nm) which is sufficient for periodontal treatment (6). sources of this light include arrange of lasers. in present, diode lasers are used predominantly. non-laser light sources like light emitting diode (led) and light cure units have tried. an ideal photo-sensitizer should be non-toxic, displaying local toxicity only after activation by illumination. most commonly use photosensitizers include phenothiazine dyes, methylene blue, and toluidine blue. pdt resulted in improved clinical parameters and decrease in tumor necrosis factorα (tnf) and the ligand for receptor activator of nf-κb (rankl) levels when used as a monotherapy in aggressive periodontitis with srp (7). principles of photodynamic therapy the knowledge of the preferred uptake and accumulation of some dyes (mostly porphyrins) into tumor tissues stimulated the introduction of pdt into clinical practice. pdt is based on the principle that a photo activable substance (the photosensitizer) binds to the cell and can be activated by light of a suitable wavelength (8). during this process, free radicals are formed (among them singletoxygen), which then produce an effect that is toxic to the cell. to have a specific toxic effect on bacterial cells, the respective photosensitizer needs to have selectivity for prokaryotic cells. although several authors have reported the possibility of a lethal photosensitization of bacteria in vivo and in vitro, others have pointed out that gram negative bacteria species, due to their special cell wall, are largely resistant to pdt(9). by irradiation with light in the visible range of the spectrum the dye (photosensitizer) is excited to its triplet state, the energy of which is transferred to molecular oxygen. the formed product is the highly reactive singlet oxygen j bagh college dentistry vol. 28(2), june 2016 photodynamic therapy oral and maxillofacial surgery and periodontics 70 capable of reacting with biological systems and destroying them. only the first excited state with energy of 94 kj/mol (22kcal/mol) above the ground state is important, the second excited state does not react. light source pdt requires a sources of light to activate the photosensitizer by exposure to low power visible light at a specific wavelength. most photosensitizers are activated by red light between 630 and 700 nm, corresponding to a light penetration depth from 0.5 cm to 1.5 cm. this limits the depth of necrosis. the total light dose, dose rates, and the depth of destruction vary with each tissue treated and photosensitizer used (10). currently, the light source applied in photodynamic therapy are those of helium – neon lasers (633 nm), gallium-aluminum – arsenide diode lasers (630-690, 830 or 906 nm), and argon laser (488-514 nm), the wavelength of which range from visible light to the blue of argon lasers, or from the red of helium-neon laser to the infrared area of diode lasers (11). recently, non-laser light source, such as lightemitting diodes (led), has been used as new light activators in pdt. led devices are more compact, portable, and cost effective compared to traditional lasers (12). photosensitizers an optimal photosensitizer must possess photo-physical, chemical, and biological characteristics. most of the sensitizers used for medical purposes belong to the following basic structure. 1. 1. tricyclic dyes with different meso-atoms e .g: acridine orange, proflavine, riboflavin, methylene blue, fluorescein, and erythrosine(13). 2. tetrapyrroles. e.g.: porphyrins and derivatives, chlorophyll, phylloerythrin, and phthalocyanines. 3. furocoumarins. e.g.: psoralen and its methoxyderivatives, 4. xanthotoxin, and bergaptene. photofrin and hematophyrin derivatives are referred to as first generation sensitizers. second generation photosensitizers include 5-aminolevulinic acid (ala), benzoporphyrin derivative, texaphyrin, and temoporfin (mthpc). these photosensitizers have greater capability to generate singlet oxygen. topical ala have been used to treat pre-cancer conditions, and basal and squamous cell carcinoma of skin (14). comparison between scaling-root-planing (srp) alone and srp/photodynamic therapy: sixmonth study. a total of 22 adults, aged 38 to 74 years, presented as out patients to the department of operative dentistry of the university medical center, johannes gutenberg university mainz. all patients (10 = female ; 12 = male) were diagnosed with chronic periodontitis, with four teeth having at least one site with a probing depth of five mm, and presence of bleeding on probing (bop). the subjects were informed in detail about the aim and course of the study and gave written informed consent. the approval of the course of the study by the ethics commission. criteria for exclusion from the present study were: presence of a systemic disease, treatment with antibiotics within the last six months, pregnancy, and smoking. for inclusion in the study, the patients had to have at least four teeth with a probing depth of ≥ 5 mm. in addition, a good patients’ compliance was required, which was monitored over the course of the study by means of measuring plaque and gingival indices. at the beginning of the study, two types of therapy were selected: scaling and root planning (srp) or srp and photodynamic therapy (srp + pdt). for each patient, it was decided by means of a randomization list, which tooth receives which type of therapy. the treatment was done according to a “split mouth design”, so that in each patient two teeth belonged to the control group (srp) and two to the test group (srp + pdt). all subsequent examinations were done by the same examiner with a fixed periodontal probe (pcp 12, hu-friedy, chicago, il, usa). all patients received a professional tooth cleaning three weeks prior to the treatment begin. the measurements of the clinical parameters were performed at baseline (one week before treatment), and one month, three and six months after treatment. clinical parameters at each visit, probing depths, absence or presence of bleeding on probing (bop), gingival recessions and clinical attachment levels at six sites per tooth (buccal; mesiobuccal; distobuccal; lingual; mesiolingual; distolingual) were recorded by the examiner. the examiner was not involved in the therapy, and therefore didn’t know which tooth had received which type of therapy (single blinded). to assess the patients’ compliance, the gingival index and the plaque index were determined in addition. course of treatment j bagh college dentistry vol. 28(2), june 2016 photodynamic therapy oral and maxillofacial surgery and periodontics 71 scaling and root planing was performed in all 22 patients by the same examiner with hand instruments (gracey curettes, hu-friedy, chicago, il, usa). teeth belonging to the test group received a photodynamic therapy in addition. for the photodynamic therapy0.005% methylene blue was used as photosensitizer and activated with a laser [periowave, ondine biopharma, vancouver, canada] at a wavelength of 670 nm and a maximum power of 150 mw for 60 seconds. all patients were assessed again by the same examiner at recall visits one month, three and six months after treatment. statistical analysis the statistical analysis of the data was performed in collaboration with the institute of medical biostatistics, epidemiology and informatics of the university medical center of the johannes gutenberg university using the program spss for medical statistics (17.0 for windows, chicago, il, usa). descriptive statistics were calculated, and values are given as means ± sd or are shown as boxplots a descriptive analysis of the gain in clinical attachment and the improvement in probing depths was performed. comparisons were made for the two different treatments (srp or srp + pdt), using as nonparametric test the wilcoxon test for paired samples. the significance level was set at p ≤ 0.05. results all subjects enrolled in the present study as outpatients, with a mean age of 59.3 years (sd: 11.7 years), could be examined as planned one month, three and six months after the end of the periodontal treatment. in each case, the chronic periodontitis could be treated successfully by means of the two different therapy concepts using a split mouth design, as it had been explained to the patients. no undesirable effects were observed, and both therapies were tolerated well by the patients. both lead to a significant reduction in the number of teeth positive when tested for bleeding on probing (bop), showed high scores for the plaque index; 73% of the patients had a score of 3. one month after the treatment, considerably lower plaque index scores were determined for both therapy forms. after three months, 77% of the teeth treated with srp alone had low scores of 0 or 1for the plaque index, and after the combined therapies of srp and pdt, in 82% of the teeth scores of 0 or 1 were found for the plaque index. after six months, a slight increase in the plaque index scores was observed; however, independent of the type of treatment, in none of the cases a high plaque index score of 3 was determined. similar results were found with regard to the measurements of the clinical attachment levels (cal) over a period of six months. at baseline, the cal measured 7.2 ± 1.2 mm (srp) or 8.1 ± 1.3 mm (srp +pdt). both therapies lead to a recognizable improvement of the cal values, with the combined therapy achieving a slightly higher gain in clinical attachment. at the end of the observation period (six months), there was a clear difference in the effect of the two therapies (p = 0.052). at baseline, the probing depth was 5.9 ± 0.8 mm (srp) or 6.4 ± 0.8 mm (srp/pdt). both after the treatment with srp alone, and with the combined treatment with srp, followed by photodynamic therapy (pdt), a clear improvement in the measured probing depths was observed over an observation period of six months. after four weeks for srp therapy alone a mean reduction of the pocket depths by 1.3 ±0.4 mm, and for the combination therapy of srp+ pdt a mean decrease in the probing depths of 1.5 ± 0.6 mm was found. however, after an observation period of six months, the combined therapy srp+pdt showed that the mean reduction in probing depths of 2.9 ± 0.8 mm statistically significant improvement (p = 0.007), in comparison to therapy alone (2.4 ± 0.6 mm). advantage of pdt 1. minimally invasive technique with least collateral damage to normal cell enhances results and superior healing. 2. exceedingly efficient broad spectrum of action, since one photosensitizer act on bacteria, virus, fungi, yeasts and protozoa. 3. efficacy independent of antibiotic resistance pattern of a given microbial strain. 4. the therapy also causes no adverse effect such as ulcers, sloughing or charring of oral tissue. 5. lesser chance of recurrence when used in treatment of malignancy. 6. economical to use. limitation of pdt systemic administration of photosensitizer causes a period of residual skin photosensitivity due to accumulation of photosensitizer under the skin. therefore photosensitizer can be activated by daylight and cause first and second degree of burns. hence, direct exposure to sunlight should be avoided for several hours until the drugs completely eliminated from the body. j bagh college dentistry vol. 28(2), june 2016 photodynamic therapy oral and maxillofacial surgery and periodontics 72 in conclusion, antimicrobial pdt seems to be a unique and interesting therapeutic approach towards periodontal and endodontic therapy. the numerous in vitro studies have clearly demonstrated the effective and efficient bactericidal effect of pdt. however, the superior effects of the adjunctive use of pdt have not been demonstrated clinically or in vivo in either periodontal or endodontic therapy. there is a great need to develop an evidence based approach to the use of pdt for the treatment of periodontitis, peri-implantitis, and endodontic therapy. it would be prudent to say that there is an insufficient evidence to suggest that pdt is superior to the tradition l modalities of periodontal therapy. further, randomized long term clinical studies and meta analyses are necessary to demonstrate the beneficial effect of antimicrobial photodynamic therapy, and in comparison with conventional methods. antimicrobial photodynamic therapy may hold promise as a substitute for currently available chemotherapy in the treatment of periodontal disease. in conclusion, it can be confirmed that the photodynamic therapy as adjunct to classical scaling and root planing can be recommended as treatment option, which can by no means replace the classical therapy concepts. but even over an observation period of six months a slightly higher improvement of the clinical parameters was achieved than with srp alone. references 1. rajesh s, elizabeth k, philip k, mohan a. photodynamic therapy: an overview. j ind soc periodontol 2012; 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2003:1-18. 9. nitzan y, shainberg b, malik z. photodynamic effects of deuteroporphyrin on gram positive bacteria. j microbiol 1987; 15:251-8. 10. hopper c, speight pm, bown sg. photodynamic therapy, an effective, but non selective treatment for cancers in the oral cavity. int j cancer 1997; 71: 93742. 11. biel ma. photodynamic therapy in head and neck cancer. curr oncol rep 2002; 4: 87-96. 12. juzneas p, ma lw, iani v, moan j. effectiveness of different light sources for 5aminolevulinic dynamic therapy. lasers med sci 2004; 19:139-49. 13. wilson m. sensitization of oral bacteria in biofilms to killing by light from a low power laser. arch 1992; 37:883-7. 14. bagnato vs, cuenca r, downie gh, sibate ch. clinical photodynamic therapy of head and neck. a review of applications and outcomes. photodiagn photodyn ther 2005; 2:202-5. j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 34 comparative evaluation of the effect of different universal adhesives and bonding techniques on the marginal gap of class i composite restoration (a sem study) ali f. al-qrimli, b.d.s. (a) abdulla m.w. al-shamma, b.d.s., m.sc., ph.d. (b) abstract background: with the increase in composite material use in posterior teeth, the concerns about the polymerization shrinkage has increased with the concerns about the formation of marginal gaps in the oral cavity environment. new generation of adhesives called universal adhesive have been introduced to the market in order to reduce the technique sensitive bonding procedures to give the advantage of using the bonding system in any etching protocol without compromising the bonding strength. the aim of the study was to study marginal adaptation of two universal adhesives (single bond™ universal and prime and bond elect) using 3 etching techniques under thermal cycling aging. materials and methods: forty-eight sound maxillary first premolar teeth were included in the study. teeth were divided into two groups according to the universal adhesive used then each group was subdivided into 3 subgroups according to the etching protocol used. standardized class i cavities were prepared in the teeth followed by the restoration of teeth using filtek™ bulk fill posterior restorative composite material. after finishing and polishing, teeth were subjected to 500 thermal cycles in 55º-5ºc bath with dwell time of 30 seconds. teeth then were examined using sem to measure the marginal gap at 12 points. data obtained were analyzed using one-way anova and lsd test for each group and with student t-test to compare the two adhesives. results: the result of this study the showed that etch and rinse technique showed significantly the least marginal gap width for both adhesive types. the selective etch technique showed lower gaps compared to the self-etch technique with no significant difference. the result showed that single bond universal showed significantly the least marginal gap for the all etching techniques compared to prime and bond elect. conclusion: the etch and rinse technique remains the most suitable technique for adhesive restoration. the type of adhesive plays an important role in adhesion. key words: marginal adaptation, universal adhesives, etching technique. (j bagh coll dentistry 2016; 28(4):34-42) introduction the increased demand for the replacement of natural dentition in the posterior region of the mouth with aesthetic restorations has resulted in increased usage of resin-based composite materials worldwide. the increase in usage caused the materials and techniques to continue developing to reduce the time of placement of the restoration as well as creating easier techniques (1). despite many new and innovative developments in the field of resin-based composite materials, a 100% perfect margin is not realistically achievable. composite materials undergo volumetric polymerization contraction of at least 2%, which may result in gap formation as the composite pulls away from cavity margins during polymerization. adhesive’s ability to seal a cavity preparation can be influenced by its composition, flow, penetration into dentinal tubules, coefficient of thermal expansion, modulus of elasticity and the mechanical stresses caused by cavity shape. (a) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (b) assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. therefore, a tight marginal seal still has to be the primary goal for the clinician, because once happened; gap formation cannot be counteracted with restorative materials. in addition to stress shrinkage, the occlusal loads and alterations of the temperature of the oral behavior produce stress on the restoration and can also compromise the marginal sealing (1,2). another disadvantage of resin-based composite restoratives include the increased technique sensitivity and time required to adequately place restorations, which can be up to two and a half times longer when compared with nominally identical dental amalgam restorations. the acid-etch, wash/dry and light irradiation component steps were reported to account for 86% of the increased time required for resin-based composite restoration placement (3). in an attempt to decrease resin bonded composite placement times, etch and rinse adhesive bonding systems which include a separate etch with acid and rinse step, a priming step followed by the application of the adhesive resin have been simplified by dental adhesive manufacturers. two-step etch and rinse adhesives were developed and today self-etch adhesives that eliminate the rinsing phase have been advocated j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 35 to significantly reduce resin bonded composite placement time (4). continuous improvements in the self-etch adhesives by better chemical composition resulted in increased adhesion to dentine, however, this improvement remained unsatisfactory in enamel. therefore, the selective etching procedure for the enamel was recommended specially for mild selfetch adhesives. on contrary, this selective etching was reported to have an adverse effect on the bonding to dentine because it is difficult to perform etching to enamel without accidental etching of dentine (5). more recently, for the aim of reducing complications of current self-etch adhesives a new family of bonding agents known as universal or multi-mode adhesives have been introduced into the dental market and are essentially one-step selfetch adhesives that can be employed with or without a separate etching step (6). the key for the success of this new generation is the chemical bonding ability of the functional monomer to hydroxyapatite and not depending on the hybrid layer (7). however, it was reported that longer resin tags and thicker hybrid layer that results from acid etching may improve the bond strength of universal adhesives, a clear correlation to higher bond strengths could not be established (6). the high quality of modern composite materials has made it more difficult to see changes in the quality of restoration margins, which in turn, has increased the need for more sensitive methods to assess the early changes of the marginal adaptation. scanning electron microscopy (sem) is a method that can be used for closer examination of the restoration margins because of its ability to magnify and reveal details (8). materials and methods teeth selection forty-eight teeth were included in the study. the criteria depended on selecting teeth with comparable size. therefore, the dimensions of all collected teeth were measured from buccopalatal and mesio-distal distance using a point vernier caliper. the selected 48 teeth were assigned into 6 groups and distributed in a way that their standard deviation is not exceeding 10% of their means. one-way anova test was performed for each dimension and no statistically significant difference was found among the 6 groups. all the teeth then were cleaned carefully for any calculus deposits with hand scalar and polished with a rubber cup and slurry of pumice then rinsed with water to remove the residual debris (9). teeth mounting a plastic container of 4.6x4.6x3cm dimensions was used to construct the silicon mold of 15x15x20mm dimensions at the center of the container for the construction of 48 acrylic-teeth blocks. a mix of self-cure acrylic resin was prepared in the mold and the tooth is inserted slowly into the center of acrylic and locked in this position for 10 minutes to give time for the acrylic to set in order to separate the rod from the tooth (fig. 1). figure 1: tooth with 8mm length showing above the acrylic cavity preparation standardized class i cavities with butt joint cavo-surface margins was prepared according to the cavity design as follows (fig. 2): 1. bucco-palatal width 3mm. 2. mesio-distal width 4mm. 3. occlusal depth 2mm from the center of the fossa. a modified dental surveyor with a modified high speed hand piece where used to perform the preparation. figure 2: cavity design samples grouping teeth were divided into 2 groups according to the type of the adhesive (group a and b) used and each group was subdivided into 3 j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 36 subgroups of 8 teeth each according to the type of the surface treatment as follows: in group a single bond™ universal adhesive (table 1) where used. in each subgroup different bonding technique were used as follows: group a1: teeth in this group were treated with the etch and rinse technique. group a2: teeth in this group were treated with the self-etch technique. group a3: teeth in this group were treated with the selective etch technique in group b prime and bond elect universal adhesive (table 2) where used. in each subgroup different surface treatment were used as follows: group b1: teeth in this group were treated with the etch and rinse technique group b2: teeth in this group were treated with the self-etch technique group b3: teeth in this group were treated with the selective etch technique bonding procedure etch and rinse groups (a1, b1) the teeth were conditioned with a 36% phosphoric acid for 15 second. after that the adhesive of each group is applied according to the manufacture instructions. self-etch groups (a2, b2) the adhesive of each group is applied according to the manufacture instructions directly without any surface treatment. selective etch groups (a3, b3) the enamel margins of the cavity were conditioned with a 36% phosphoric acid for 15 second making sure no acid etch gel reach or touch the dentine. after that the adhesive of each group is applied according to the manufacture instructions. restoration procedure after completion of the adhesive procedure, each tooth was restored with filtek™ bulk fill posterior restorative composite material using a single increment finishing and polishing was preformed was preformed followed by checking of teeth with a stereomicroscope (altay, italy) at 20x magnification to ensure that no overhangs of the restoration material remain along the margins of the restorations. thermocycling procedure all samples were subjected to 500 thermal cycles in 5 °c and 55°c water baths with dwell time of 30 seconds according to the iso tr 11405 (10) in order to simulate the oral cavity environment. sem examination all the samples were examined by inspect s50 sem at 2000x magnification under low vacuum to detect marginal gaps along the composite/enamel interfaces at the occlusal regions (fig. 4). the measurement of marginal gap width (the distance between the enamel wall and the restoration) in each sample were taken at twelve points at the occlusal region (3 points in buccal side, 3 points in palatal side, 3 points at the mesial side and 3 points in distal side) (fig. 3) (1). figure 3: points location used for the sem examination a c b j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 37 figure 4: (a) represent gaps of group a1 (b) represent gaps of group a2 (c) represent gaps of group a3 (d) represent gaps of group b1 (e) represent gaps of group b2 (f) represent gaps of group b3 table 1: composition of the two universal adhesives bonding used materials composition single universal adhesive (sbu) 10-mdp phosphate monomer, dimethacrylate resins, hema, vitrebond™ copolymer, filler, ethanol, water, initiators, silane. prime and bond elect universal adhesive (pbe) mono-, diand trimethacrylate resins; penta (dipentaerythritol penta acrylate monophosphate); diketone; organic phosphine oxide; stabilizers; cetylamine hydrofluoride; acetone; water. statistical analyses the data were collected and analyzed using spss (statistical package for the social science, version 22) for statistical analysis. results a total of 576 enamel/composite gap measurement were examined by sem and recorded. the largest measurements in each surface were used in the statistics. descriptive statistics the means, standard deviations, minimum and maximum values for each group are summarized in (table 2). the lowest mean values for the marginal gaps width (µm) was for the group a1, while the highest mean values for the marginal gaps width (µm) was for group b2. inferential statistics effect of the adhesive technique one-way anova test showed that there were statistically highly significant differences among the different subgroups for both types of adhesives (table 3). lsd test result showed that subgroup a1 produced the least gap which was statistically very highly significant difference compared with subgroups a2 and a3. however, there was no statistically significant difference between subgroup a2 and a3 (table 4). the result also showed that subgroup b1 produced the least gap which was statistically very highly significant difference compared with subgroups b2 and statistically significant difference with subgroup b3. lsd test also showed that there was no significant difference in the marginal gaps between subgroups b2 and b3 (table 4). effect of the type of adhesive type student t-test was used to examine if there is any significant difference between each subgroup of group a with its corresponding subgroup in group b. the result showed that there was a significant difference in the gap width between group a1 and b1 and group a3 and b3 and also a highly significant difference in the gap width between group a2 and b2 (table 5). e d f j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 38 table 2: table showing mean, sd, se, minimum and maximum of the data collected material group surface treatment group descriptive statistics mean s.d. s.e. min max group a (3m espe single bond universal adhesive) a 1 etch and rinse group 6.495 1.189 .42 4.69 8.17 a 2 self-etch group 10.406 1.867 .66 7.712 13.151 a3 selective etch group 9.89 1.72 .608 7.045 11.427 group b (dentsply prime and bond elect universal adhesive) b 1 etch and rinse group 8.792 1.208 .427 7.102 10.6 b 2 self-etch group 13.995 2.618 .925 9.637 16.751 b 3 selective etch group 11.901 2.492 1.101 8.634 14.832 table 3: anova test for both group a and group b group anova sum of squares df mean square f-test sig. a between groups 72.227 2 36.114 13.788 .000 (vhs) within groups 55.004 21 2.619 total 127.231 23 b between groups 109.686 2 54.843 11.329 . 000 (vhs) within groups 101.658 21 4.841 total 211.344 23 table 4: lsd test between the subgroup of both group a and group b groups subgroups mean difference sig. group a a1 a2 -3.911 .000 (vhs) a3 -3.395 .000 (vhs) a2 a3 .5157 .531 (ns) group b b1 b2 -5.204 .000 (vhs) b3 -3.109 . 010 (hs) b2 b3 -2.094 .071 (ns) table 5: student t-test to study the effect of the type of adhesive on the marginal gap subgroup t-test df sig. a1 – b1 -2.836 7 .025 (s) a2 – b2 -4.981 7 .002 (hs) a3 – b3 -2.367 7 . 05 (s) discussion type of adhesive technique in this study, the marginal quality of two types of universal adhesives was investigated under different etching modes with the effect of aging with thermal cycling. the results of this study revealed that etch and rinse technique produced the lowest gap which is significantly lower than self and selective etch techniques for both adhesives. the superiority of etch and rinse technique could be due to many reasons: 1. in enamel, etching creates micro-retentive porosities that facilitate the micro mechanical interlocking of adhesive and this may be considered the mechanism of etch and rinse bonding technique (11,12). a more reliable clinical result was obtained with the use of phosphoric acid etching which increase the surface area for micromechanical retention (11-13). in a study done by alessandro et al (14), they showed that with phosphoric acid pre-etching there is an increase in the surface area in intact and ground enamel after the application of self-etch adhesives which is lower than that achieved with self-etch adhesive alone. consequently, the performance of self-etch adhesives is significantly improved with preliminary phosphoric acid etching which is in an agreement with the result of this study where eandr technique performed better with the adhesives used. moreover, it was reported from earlier studies that etch and rinse technique creates a micro morphological interaction that extend deeper into enamel (15). when compared with universal and self-etch adhesives, the reduced acidity renders the adhesive to create less and shallower microretentive porosities which is due to the fact that they are unable to fully demineralize the mineral phase of enamel and this may compromise the adhesion to enamel (16). to explain this more, the self-etch technique renders the monomer to a shallower inter-crystallite infiltration and also lack the presence of inter-prismatic resin tags resulting in lower micromechanical interlocking with enamel (17). this was supported by many j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 39 studies that reported an increase in the micro shear and micro tensile bond strength to enamel of universal adhesives when etching step was employed (18). in one study the presence of air void along the enamel-composite interface was reported to be a stress raiser which may provoke crack propagation along the interface. in the same study they found that the absence of resin tags in self-etch systems may be responsible for the decreased marginal quality. on the other hand, the presence of resin tags with the etch and rinse technique may provide 3 dimensional grasp along the etched surface. this may act as a crack deflector that may consume the fracture energy and improve the fracture toughness of the interface producing a lower gap (13). the result of this study came in agreement with a study that indicates that preforming the etching step is still the most reliable technique to get a better bond strength and to have an enamel bond with the highest fatigue resistance. this is reflected on the marginal quality of the enamel/composite interface and since universal adhesive is essentially one step self-etch its ability to etch enamel is limited (14,19,20). additional agreement was found in a study done by nihan et al (21), were they found that samples treated with etch and rise technique and thermocycled between 1000 and 5000 cycle had the lowest microleakage scores which indicate longer bonding resistance in enamel. 2. in dentin, the etching step before the application of the self-etch adhesive aid in removing the smear layer to make it easier for the adhesive to penetrate and infiltrate the surface morphology and this creates longer resin tags and thicker hybrid layer. this increase in the penetration has been reported for universal adhesive as well where an increase in the infiltration and improvement in the resin tag length and morphology was also reported compared with the self-etch mode alone (6). this result was in agreement with one study where its result indicates that prior etching of dentine produce a better impregnated hybrid layer which resulted in increased µ tensile bond strength when compared with only self-etching technique (22). in one study, when the universal adhesives applied in self-etch mode did no modification of smear layer or penetration into the dentinal tubules and the hybrid layer was very thin or inexistent and was in agreement with others studies conducted with self-etch adhesives. for this reason, decrease in the overall bond strength may occur and this may reflect on the marginal quality of the restoration (23,24). from the result of this study, the mean of gap was lower for the selective etching giving it the advantage when compared with the self-etch for both adhesive systems used, however the difference was not significant. the superiority of selective etching over the self-etch groups could be related to the additional step of enamel acid etching which might provide a better micro mechanically prepared enamel surface for bonding. although the result showed that there is no significant difference between the self and selective modes. this could be due to the number of cycles used in this study which is 500 thermal cycle which may be not enough to show a significant difference. this result came in agreement with one study that showed a non-significant difference in the marginal quality and restoration retention with and without prior etching of the enamel (25). moreover, peumans et al (26) mentioned that there was no significant difference between restoration retention in cervical region with and without selective enamel etching. it was suggested that enamel pre-etching with phosphoric acid may provide greater bond strength and better sealing ability of the margins (25). however, in one clinical trial study, a universal adhesive was evaluated with and without the selective etching step. the result showed there was no different in the retention of the restoration and only a reduced in the marginal quality of the self-etch group after 18 months (27). clinical studies pointed out that enamel preetching resulted in a more durable marginal integrity of restorations bonded with self-etch adhesives. nevertheless, it is a challenge in clinical situations to use phosphoric acid only on enamel margins, as accidental dentin etching might occur; especially if a low-viscosity etchant is used (11). type of adhesive material the result of this study showed that single bond universal produced lower compositeenamel gap compared to prime and bond elect universal adhesive regardless to method used. there is no previous study in literature that measure the two adhesives used in this study (sbu, pbe) regarding marginal gap. the result of this study came in agreement with a study performed by luque-martizez et al (28) who found an increase in the micro tensile bond strength (µtbs) of sbu compared to pbe. this increase in the µtbs of the sbu may suggest a better marginal adaptation with lower j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 40 gap. moreover, the result was also in agreement with issis et al (29) who found also that pbe has the lowest µtbs compared to sbu in different evaporation times. this superiority may be explained by the difference in the composition of the two adhesives in term of different monomer, solvent and presence or absence of filler (14). the effect of each component can be explaind in the following point. 1. the presence of 10-methacryloyloxydecyl dihydrogenphosphate (10-mdp) in the sbu may be one reason why it performs better that the pbe. this functional monomer can form a low soluble calcium salt on the hydroxyapatite surface which creates a durable and more effective bond to dentine (30). 10-mdp not only bonds to the hap but also self-assemble into nanolayers that have a high hydrophobic feature that helps in protecting the hybrid layer from hydrolytic degradation (5). in one study, the author found that there is an increase in the µtbs bond strength in two universal adhesives that contain 10-mdp monomer which was statistically significant than that observed with adhesive that does not include this monomer (6). on the other hand, the penta monomer has no data in literature to prove its efficiency and effect on bonding. the presence of hema in sbu may be the reason for the better mechanical properties of this adhesive which resulted in higher µtbs which reflected on the decreased marginal gap. since sbu is a hema containing adhesive, the solvents can be easier to remove and since the hema also functions as a solvent this result in lower solvents (water, ethanol) concentration (31). this feature also prevents phase separation where the hema replace the evaporated solvent and keep the components together (32). in addition, hema is a very hydrophilic monomer that’s makes it very effective in wetting the dentine and that is why it is one of the best adhesion improving monomers (33). since pbe is a hema free adhesive, the mixture of the hydrophobic and hydrophilic components makes the adhesive susceptible to phase separation which may be the reason for its lower mechanical properties (31). 2. the presence of filler in sbu may be one of the reasons that it performed better since the pbe is unfilled adhesive. two reasons may be responsible for this effect. adhesive is considered the weak link between composite and tooth structure and since it was traditionally unfilled, the addition of filler was proposed in several studies to fortify and to enhance the physical properties of adhesives which will lead to increase performance and may lead to a lower marginal a gap (34). moreover, some manufactures add fillers to adhesive to change the viscosity and to achieve a thicker hybrid layer to overcome the problem of insufficient polymerization, due to the air inhibited layer, of overly thinned adhesive after air thinning specially on enamel margins which may lead to marginal discrepancy (35). 3. the difference in the solvent composition between sbu (ethanol/ water) and the pbe (acetone/water) may be the reason for the superiority of sbu. it was found that ethanol can re-expand the collapsed collagen fibers because of the hbonding property of the solvent and this may be an enhancing feature for the sbu (35). on the other hand, acetonelack the ability of reexpanding collapsed collagen fibers due to the absence of h-bonding capability which in turn affect the pandb ability to expand the collapsed collagen fibers (36). solvents help the infiltration of monomers into the demineralized spaces of dentin and enamel and lower the viscosity of the adhesive (29). hence acetone has a higher vapor pressure, it can evaporate so quickly after it’s been dispensed and this leads to a fast increase in the viscosity of the liquid that may hinder its ability to infiltrate the dentin leading to a lower bonding strength (36). it was reported if solvents are not removed entirely form the adhesive, it can inhibit the polymerization of the resin monomers leading to a lower bonding strength (29). it was reported that even with the increase of the vapor pressure of acetone where it should evaporate easily (37), the result was in disagreement in one study where the pbe required a longer evaporation time than the recommended by the manufacture and this may be due to the high concentration of the acetone 50 wt%. this led to the presence of residual solvent in the adhesive resin decreasing the bonding strength (38). on the other hand, sbu have a low concentration of ethanol, 10-15 wt%, which in turn evaporated easily according to the manufacture instruction (29). under the experimental conditions of this in vitro study, the following conclusions can be drawn: 1. none of the universal adhesives produced a zero gap margins regardless of the etching mode employed. 2. etch and rinse technique produced the lowest marginal gap compared with other bonding techniques for both types of adhesives. j bagh college dentistry vol. 28(4), december 2016 comparative evaluation restorative dentistry 41 3. self-etch technique produced the largest gap 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zhang y, lockwood pe, rueggeberg fa, pashley dh. effects of hema on water evaporation from water–hema mixtures. dent mater 1998; 14(1): 6–10. 38. cho bh, dickens sh. effects of the acetone content of single solution dentin bonding agents on the adhesive layer thickness and the microtensile bond strength. dent mater 2004; 20:107–15. mustafa.doc j bagh college dentistry vol. 27(1), march 2015 evaluation of pedodontics, orthodontics and preventive dentistry 175 evaluation of a new orthodontic bonding system (beauty ortho bond) mustafa m. al-khatieeb, b.d.s., m.sc. (1) shahbaa a. mohammed, b.d.s., m.sc. (1) ali m. al-attar, b.d.s., m.sc. (2) abstract background: the purpose of the current study was to evaluate the efficacy of a new orthodontic bonding system (beauty ortho bond) involving the shear bond strength in dry and wet environments, and adhesion remnant index (ari) scores evaluation in regard to other bonding systems (heliosit and resilience orthodontic adhesives). materials and methods: sixty defect free extracted premolars were randomly divided into six groups of 10 teeth each, mounted in acrylic resin, three groups for a dry environment and three for a wet one. shear bond strength test was performed with a cross head speed of 0.5 mm/min, while surfaces of enamel and bracket-adhesive-enamel surfaces were examined with stereomicroscope for ari scores evaluation. data were analyzed by one way analysis of variance, least significant difference, student's t-test, and fisher exact test. results: the mean shear bond strength showed highest values for resilience adhesive followed by beauty ortho bond and heliosit adhesives respectively both in dry and wet environments. interestingly, there was a non-significant difference (p<0.05) between resilience and beauty ortho bond adhesives using least significant difference at dry environment. in wet environment the beauty ortho bond showed an acceptable mean shear bond strength value (6.39 mpa) which is considered as a clinically acceptable value. adhesive remnant index scores demonstrated a tendency towards score 1 in dry environment, and towards score 3 in wet environment, the scores also showed a non-significant difference (p<0.05) between resilience and beauty ortho bond adhesives using fischer exact test. conclusion: beauty ortho bond is less sensitive to wet environment than resilience and heliosit adhesives, therefore it has an advantage during clean up, as it reduces the risk of enamel damage during debonding procedure. keywords: beauty ortho bond, shear bond strength, light cured composite. (j bagh coll dentistry 2015; 27(1):175181). introduction since the introduction of the concept of the acid etching that was invented by buonocore in 1955(1), then the direct bonding of orthodontic appliances to enamel with composite resin was introduced by newman in 1965 (2).at current time, the bonding of different attachments, such as brackets and tubes, on the enamel surface is a routine clinical procedure, typically using a resin composite adhesive (3-6). many researches described the use of phosphoric acid for creating micro-irregularities in the enamel surface to enhance mechanical interlocking, the effect of time factor (7,8), and concentration of phosphoric acid (9) have been investigated to determine the most suitable technique of enamel preparation. in spite the bond strength to the tooth structure is favorable in restorative dentistry, the bond strength in orthodontics must give two durable requirements, it must be so sufficient to retain the brackets but low enough to allow easy removal and cleanup of the adhesive remnants during brackets debonding procedure (10). (1) assistant professor, department of orthodontics, college of dentistry, university of baghdad. (2) lecturer, department of orthodontics, college of dentistry, university of baghdad. it has been recommended that the bond strength values must fall in the rage of six to eight mega pascal, which are sufficient to get a clinically effective orthodontic bonding procedure (5,10,11). the higher bond strength may increase the risk of enamel chipping (12).although acid etching of enamel may cause micro-roughness about 1020 micrometer (4,9). most orthodontists accept enamel surface acid etching as a routine technique which has a risk of iatrogenic enamel deterioration, such as surface staining stemming from increased surface porosity, discoloration by resin tags retention in enamel, enamel fracture, and chipping (10,13). advances in an adhesive technique have let orthodontists to incorporate new adhesives, composite resins and bonding techniques into clinical practice, the invention of self-etching primer is to expedite the bonding procedure by combining etching and priming into a single step (14). furthermore, saving time and reducing procedural faults, their lower etching capability, due to higher ph relatively to the acid etch technique, which it might decrease the potential for iatrogenic enamel damage (14-16). the purpose of the current study was to evaluate the efficacy of a new orthodontic bonding system (beauty ortho bond®)involving the shear bond strength in dry and wet environments, and adhesive remnant index scores evaluation in regard to other bonding systems. j bagh college dentistry vol. 27(1), march 2015 evaluation of pedodontics, orthodontics and preventive dentistry 176 materialsand methods tooth specimens ninety four human healthy maxillary first premolars teeth were collected for orthodontic purposes from 15-25 years old iraqi patients seeking the orthodontic treatment, all the teeth were examined for any visible decalcification, hypoplastic areas by using light curing unit, any tooth that has a defect was discarded, and only 60 teeth were included in the current study, then the teeth were washed with water and stored in normal saline in a sealed box for 1-3 months at room temperature (220 ±3) and the normal saline changed it periodically until bonding procedure (17,18), then the 60 teeth were randomly allocated into six groups of ten for shear bond strength measurement. mounting of the teeth: the roots of the included teeth were serrated by a diamond disk, made a retentive wedge shaped to increase the teeth retention inside the self-cured acrylic blocks, then each tooth was fixed on a glass slide in a vertical position using soft sticky wax at the root apex, so that the middle third of the buccal surface was oriented to be parallel to the analyzing rod of the surveyor, so that the force could be applied at right angle to the enamel-bracket interface (19). another tooth was fixed on the glass slide about 1 cm away from the first tooth and was oriented in the same manner, then three more teeth were placed and fixed on the glass slide in the same way of the second tooth in order to have five premolars fixed on the glass slide one cm apart, having the middle third of the buccal surface of each tooth parallel to the analyzing rod of the surveyor and the occlusal surface of each tooth oriented to the same height by using a stone disc bur (20), then the two l-shaped metal plates were painted with a thin layer of a separating medium (vaseline), and placed opposite to each other in such a way to form a box around the vertically positioned teeth with the crowns protruding. then the powder and liquid of the cold cured acrylic were mixed and poured around the teeth to the level of the cement-enamel junction of each tooth. after cold cure acrylic resin setting, the two l-shaped metal plates were removed, the sticky wax used for fixation of teeth in the proper orientation removed too and the resulting holes filled with cold cure acrylic, slightly adjustment of the acrylic blocks was done using a portable engine. after mounting, the teeth were stored in normal saline solution to prevent dehydration until bonding procedure (21). preparation of bracket-bonded specimens the 60 teeth were separated into six equal groups (10 teeth each), three groups for a dry environment testing were separated and the other three groups for a wet environment testing. 60 new stainless steel standard edgewise ultratrim brackets (dentaurum/ germany) were used with coarse mesh base with surface area of 10.165 mm2, the buccal surface of all teeth were cleaned and polished using non-fluoridated pumice (dfl minmet refractories corp; shijiazhuang/ china) for 30 seconds (each tooth), then washing with water spray for 10 seconds, drying with air syringe for 10 seconds, oil and humidity free, then each one of the three bonding systems was applied on 20 teeth (10 teeth in dry environment and 10 in wet), the three bonding systems (table 1) in the current study were classified into the following groups: group 1 (an adhesive system with a primer and needs an etchant):the enamel surfaces were treated with 37% phosphoric acid etching agent (etching agent, resilience; orthotechnology; fl/usa) and allow the etchant to remain for 30 seconds, washed for 20 seconds with an air/water spray, and dried for 20 seconds with an oil and humidity free air stream, the etched enamel surface should be of a white chalky appearance, a primer (sealant resin,resilience light cure adhesive; orthotechnology; fl/usa) was applied with a cotton applicator on etched enamel surface, then the metal bracket base was bonded with adhesive paste (resilience light cure adhesive; orthotechnology; fl/usa), seat the bracket on the tooth with light pressure and after positioning press firmly to place not express all the paste from under the bracket, remove any gross excess of paste that expresses from around the bracket, light cure the adhesive from two directions (incisal and gingival or mesial and distal) by a light cure unit (radii plus, high powered cordless led curing light, sdi; austria). excess bonding was removed with a small scaler. all samples were light cured for 20 seconds (10 seconds for each proximal side) following the manufacturer instructions, after performing the bonding procedure the specimens were immersed in normal saline solution and stored in incubator at 37oc for 24 hours before the bond strength testing (22,23). group 2(an adhesive system with no primer but needs an etchant): the enamel surface was treated with 37% phosphoric acid (total etch, ivoclarvivadent clinical; schann/liechtenstein), and allow the etchant to remain on enamel surface j bagh college dentistry vol. 27(1), march 2015 evaluation of pedodontics, orthodontics and preventive dentistry 177 for 30 seconds, washed for 20 seconds with an air/water spray and dried for 20 seconds with an oil and moisture free air stream, the enamel surface becomes chalky white, apply the translucent low viscosity adhesive agent (heliosit orthodontic adhesive, ivoclar vivadent clinical; schann/liechtenstein) to the under surface of the metal bracket, then position the bracket on the tooth surface, cure with the light unit (radii plus, high powered cordless led curing light, sdi; austria), and follow the previous instructions. group 3(an adhesive system with no etching gel but with a self-etching primer with fluoride releasing property) (figure 1): primer a and primer b were mixed, then the solution was rubbed on enamel surface for approximately three seconds. an air jet was briefly applied to the enamel surface, and the paste (beauty ortho bond, shofu; kyoto /japan) was applied onto the back of bracket base, then position the bracket on the tooth surface, cure with the same light unit in groups one and two, and follow the same previous instructions. each primer-composite combination was tested under two different enamel surface conditions: dry and saliva application (wet), therefore: figure 1: beauty ortho bond (shofu; kyoto /japan) groups 4, 5, and 6:apply the same bonding, systems in groups 1, 2, and 3 respectively but in wet environment, to achieve a saliva contaminated condition (wet environment), human saliva from one donor was applied with a brush on to the buccal surfaces without air jet "after priming in groups 1 and 3, and after etching in group 2". then, the brackets were bonded with composite paste, for the group 6 (in wet environment testing of beauty ortho bond), also apply salivatect paste on tooth surface, not just the standard paste on base of bracket. each bonding procedure was done by the same operator. excess bonding was removed with a small scaler. all samples were light cured for 20 seconds (10 seconds for each proximal side) following the previous manufacturer instructions, after performing the bonding procedure the specimens were also immersed in normal saline solution and stored in incubator at 37oc for 24 hours before the bond strength testing (22,23). shear bond strength test (figure2) the embedded specimens (teeth in the acrylic blocks) were secured in a jig attached to the base plate of an instron universal testing machine (tinius olsen, model 1150, england). a chiseledge plunger was mounted in the movable cross head of the testing machine and positioned so that the leading edge was aimed at the enamel/composite interface, the speed of the cross head was 0.5mm/minute, and the maximum load necessary to debond the bracket was recorded, the force required to remove the brackets was measured in newtons (n), and the shear bond strength (1mpa= 1n/mm2) was then calculated by dividing the force values by the bracket base area (10.165mm2). figure 2: the embedded specimen (teeth in the acrylic block) was secured in the sliding jig residual adhesive after debonding procedure, all teeth and brackets were examined under x20 magnification of a stereomicroscope (olympus, tokyo, japan), the adhesive remnant index (ari) scores were evaluated by the same operator, enamel surface was scored using the criteria proposed in ari of wang et al. (24), as follows: score 1= the failure occurred between bracket base and adhesive. score 2= cohesive failure occurred within the adhesive itself. score 3= adhesive failure occurred between adhesive and enamel. score 4= enamel detachment. j bagh college dentistry vol. 27(1), march 2015 evaluation of pedodontics, orthodontics and preventive dentistry 178 statistical methods all statistical analyses were performed with the statistical package for social science (spss for windows, 16.0, chicago, illinios/usa). descriptive statistics, including the mean, standard deviation, minimum, and maximum shear bond strength values were calculated for the six groups, furthermore, number and percentage of observations for ari scores were also evaluated. inferential statistics, including one way analysis of variance (anova) was used to determine any statistical difference between shear bond strength values of the three bonding systems in both dry and wet environments, least significant difference was used to compare between each two groups of bonding systems in both dry and wet environments. a student's t test was used to compare the shear bond strength data of ortho beauty bond "bob" with other bonding groups under different environments, fisher exact test was used to test the exact relationship of ari scores values between dry and wet environments. the levels of probability in statistical evaluation were: significance at 0.05≥p>0.01; highly significance at 0.05 ≥ p>0.001; and nonsignificance at p>0.05. results the descriptive statistics of shear bond strength for each group of the three adhesive systems are presented in table 2. in both dry and wet environments, highest mean shear bond strength values were found in groups 1 and 4 (resilience light cure adhesive), followed by groups 3 and 6 (bob), and groups 2 and 5 (heliosit orthodontic adhesive) respectively. when comparing the three adhesive systems, there were highly significant differences (p=0.000) in the mean shear bond strength values using anova test in both dry and wet environments. the results of the student's t-test for the independent samples (between dry and wet environments) revealed highly significant differences (p=0.000) in the mean shear bond strength values, with lower mean values in wet environment (groups 4, 5, and 6) than dry environment (groups 1, 2, and 3), as shown in table 2. the least significant difference (lsd) test for the three adhesive systems in dry environment showed that there were highly significant differences (p=0.000) between groups 1 and 2, and groups 2 and 3, while there was a no significant difference (p>0.05) between groups 1 and 3. in wet environment there were highly significant differences (p=0.000) between the three adhesive systems (groups 4, 5, and 6), as shown in table 3. adhesive remnant index (ari) scores (table 4) indicate the site and mode of bond failure for the three adhesive systems in dry and wet environments. the ari scores of the three adhesive systems had a slight tendency towards score 1 (failure between bracket base and adhesive) in dry environment, while revealed a slight tendency towards score 3 (adhesive failure between adhesive and enamel) in wet environment. the scores showed a highly significant difference (0.05 ≥ p > 0.001) between groups 1 and 4, and a significant difference (0.05 ≥ p > 0.01) between groups 2 and 5, and a nonsignificant difference (p>0.05) between groups 3 and 6, respectively, when fisher exact test was used. discussion ever since the procedure of bonding was introduced by neuman into orthodontic practice (2), there has been a constant endeavor to improve the qualities of materials in bonding procedures. the search still continues, ideally, the bond strength needs to be optimum rather than too much or too less. excessive bond strength increases the risk of damage to enamel during debonding and too weak bond strength results in frequent bond failures during the course of treatment. according to reynolds, the optimum bond strength should be in the range of 5.9-7.8 mega pascal (25). researchers have been attempting to gain the best quality and gentlest techniques for bonding orthodontics brackets, various new developments have been made to help improve the technique, these developments have concentrated on improving bond strength, decreasing bonding time, reducing the number of bonding steps, and decreasing the adhesive remnants. all these advances have worked towards creating the best bonding protocol while maintaining enamel health during treatment and after debonding. as newer and more efficient products are marketed worldwide, evaluation of their interactions with other orthodontic products available to practitioners, as well as their effect on enamel must be performed. the current study compared shear bond strength of the new adhesive (bob) with two adhesives (resilience and heliosit) available in iraqi market. all of these adhesives were light cured type. it is important to mention that the mean shear bond strength values for all the adhesive (resilience, heliosit, and bob) were greater than 6-8 mpa previously reported (25,26), as j bagh college dentistry vol. 27(1), march 2015 evaluation of pedodontics, orthodontics and preventive dentistry 179 an adequate bond strength for routine bonding procedure in both dry and wet environments, with highest mean shear bond strength value for resilience followed by bob and heliosit adhesives respectively in dry condition, except for the heliosit adhesive in wet condition, showed lowest and unacceptable (to the suggested range) mean shear bond strength value, as shown in table 2, this may be due to variation in the amount of glass filler in resilience and bob, and the glass filler absence in heliosit. furthermore, contamination of enamel with saliva after priming as in groups 4, 5, and 6 decreases the mean shear bond strength values for the three adhesives, although it still practically adequate except for heliosit, where it was unacceptable in wet environment (condition 5). the decrease in shear bond strength in wet environment comes in agreement with another research (27), which stated that humidity decreases the shear bond strength because the saliva consistency could have caused that the adhesive was not in contact with the etched enamel surface at the time of polymerization of the adhesive system, thus producing poor mechanical retention. the least significant difference test showed that there was a non-significant difference between groups 1 and 3 (resilience and bob adhesives) in dry condition, because both of the adhesives exhibited high mean shear bond strength values, as shown in tables 2 and 3. in general the shear bond strength tests involve numerous variables and are technique-sensitive, so the same bonding study can have varying results under different experimental conditions, or when performed by different orthodontists. in addition an in-vitro bonding enamel is very different from an in vivo bonding environment. factors such as the patient's enamel composition and saliva contamination can cause the same bonding research to yield different results when performed in intraoral environment. thus it is important to conduct more clinical studies. in orthodontics, the site of bonding failure is important because an effort is made to maintain an intact and sound enamel surface after debonding. thus, in order to minimize the risk of enamel damage, it is more desirable for bond failure to occur within the adhesive or at the bracket-adhesive interface than the adhesiveenamel interface. however, a smaller adhesive remaining after debonding, the perfect bonding procedure would be, because it would leave a healthy enamel surface without large amount of adhesive to remove. when evaluating the adhesive remnant index (ari) scores for the three adhesives, in dry conditions groups 1, 2, and 3 had showed a slight tendency towards score 1(failure between bracket base and adhesive),this implied that the bond strength would be strong at that locus, in wet conditions groups 4, 5, and 6 had showed a slight tendency towards score 3 (adhesive failure between adhesive and enamel), this implied that the bond strength at enamel bonding resin interface would be weak at that locus because of wet condition (saliva). when fisher exact test was used to compare the scores between dry and wet conditions, the scores showed a non-significant difference (p>0.05) between groups 3 and 6, that means the bob is less sensitive to wet condition than the other two adhesives (resilience and heliosit), and the more frequent bond failure occurs at the enamel-adhesive interface, this may be due to the hydrophilic nature of the salivatect paste of bob that allows to function in the presence of saliva contamination, perhaps displacing or diffusing through it, to infiltrate and polymerize within the micromechanical retention of the etched enamel surface, so bob anticariogenic property that comes from the fluoride releasing ability because of presence of pre-reacted glass ionomer filler, might help orthodontists to decrease the risk of enamel damage and to remove residual adhesive form the enamel surface easily at debonding. however, a smaller adhesive remnant can mean less chair time for removal of the adhesive remaining after debonding. the ideal bonding system would leave a healthy enamel surface without large amounts of adhesive to remove, and thus prevent iatrogenic enamel loss. furthermore, the locus of bond failure is determined by a complex combination of contributory factors including the direction of the force applied, enamel pretreatment, the adhesive itself, and the bracket type. within the limitation of this in vitro study, the following conclusions should be drawn: 1. all these adhesives demonstrated adequate bond strength to withstand orthodontic forces throughout the experiment, except for heliosit, which exhibited unacceptable bond strength 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23: 85-90.(ivsl) 14. zeppieri il, chung ch, mante fk. effect of saliva on shear bond strength of an orthodontic adhesive used with moisture-insensitive and self-etching primers. am j orthod dentofacial orthop 2003; 124: 414-9. 15. pashley dh, tay fr. aggressiveness of contemporary self-etching adhesives. part ii: etching effects on unground enamel. dent mater 2001; 17: 430-44. 16. basaran g, ozer t, kama j. comparison of recently developed nanofiller self-etching primer adhesive with other self-etching primers and conventional acid etching. eur j orthod 2009; 31:271-5. 17. alexander jc, viazis ad, nakajima h. bond strength and fracture modes of three orthodontic adhesives. j clin orthod 1993; 27(4):207-9. 18. meng cl, wang wn,yeh is. fluoridated etching on orthodontic bonding. am j orthod dentofacial orthop 1997; 112: 259-62. 19. klocke a, kahl-nieke b, effect of debonding force direction on orthodontic shear bond strength. am j orthod dentofacial orthop 2006; 129: 261-5. 20. swanson lt, beck jf. factors effecting bonding to human enamel with specific reference to a plastic adhesive. am j dent assoc 1960; 61: 581-6. 21. beck dr, jalaly t. bonding of polymers to enamel influence of deposits formed during etching, etching time and period of water immersion. j dent res 1980; 59:1159-52. 22. wang wn, li ch, chou th, wang dh, lin lh, lin ct. bond strength of various bracket base designs. am j orthod dentofacial orthop 2004; 125:65-70. 23. sharma-sayal sk, rossouw pe, kufkami gv, titley kc. the influence of orthodontic bracket base design on shear bond strength. am j orthod dentofaial orthop 2003; 124:74-82. 24. wang wn, meng cl, tarng th. bond strength: a comparison between chemical coated and mechanical interlock bases of ceramic and metal brackets. am j orthod dentofacial orthop 1997; 111(4): 374-81. 25. reynolds ir. a review of direct orthodontic bonding. br j orthod 1975; 2: 171-178. 26. frota p, tanaka a,loguercio a, lima d, carvalho c, bauer j. effect of different times of solvent evaporation and ph in two self-etching adhesive systems on the shear bond strength of metallic orthodontic brackets. international j adhesion &adhesives 2014; 40:223-27. 27. orendin dr, espinolos gs. comparison between the adhesive forces of two orthodontic systems with moisture affinity in two enamel surface conditions. revista mexicana de orthodoncia 2014; 2(2): 87-92. الخالصة یابقا معامل تقییم في البیئة الجافة والرطبة وكذلك القصیة من خالل حساب قوة اللصق) بیوتي اورثو بوند ( تقیم فعالیة مادة الصقة تقویمیة جدیدة ھول من ھذه الدراسة الغرض :الخلفیة .المادة الالصقة بالمقارنة مع بقیة انواع اللواصق تحتوي كل مجموعة على عشرة اسنان ، ثبتت ھذه االسنان بواسطة مادة االكریلیك؛ ثالثة مجامیع ,مجامیع ستة تم تقسیمھا الى خالي من االضرار ون سنا ضاحكاتس :المواد والطرق بینمااسطح واجھاتوصالت المینا والمواد الالصقة , دقیقة/ملم 0,5أحتساب قوة اللصق القصیة بجھاز االنسترون ذي الرأس الصلیبي وبسرعة تم .لبیئة الرطبةللللبیئة الجافة وثالثة .والحاصرات السنیة تم فحصھا بواسطة مجھر لتقییم معامل بقایا المادة الالصقة من المثیر , البیئة الجافة والرطبة كالمن لیوست فيیلینس ذات التصلب الضوئي ثم في بیوتي اورثو بوند واخیرا في ھزیمعدل قوة اللصق القصیة كانت اعلى قیمة في مادة الر :النتائج .ة الرطبة قوة لصق مقبولة ایضا في البیئ كما وجد,بأستعمال اختبار أل أس دي لینس وبیوتي اورثو بوند في البیئة الجافةزیلم یتم تسجیل فرق معنوي بین مادة الر لالھتمام یظھر اي فرق معنوي في ھذا المعامل بین لم و ةالدرجة الثالثة في البیئة الرطب اضھر میل نحوالدرجة االولى في البیئة الجافة ، بینما میل نحو معامل بقاء المادة الالصقةكما اضھر .لینس وبیوتي اورثو بوند باستخدام اختبار فیشرزیالرتي ماد لصق الحاصرات السنیة من سا للرطوبة من بقیة مواد اللصق وكذلك ھي سھلة التنظیف مما یقلل من خطر تكسر مادة المینا اثناء عملیة ازالة سي اورثو بوند اقل تحمادة بیوت :االستنتاج .االسنان j bagh college dentistry vol. 27(1), march 2015 evaluation of pedodontics, orthodontics and preventive dentistry 181 table 1: the bonding systems employed in the present study table 2: descriptive statistics, comparative statistics for the shear bond strength (mpa) of the three adhesive systems in both dry and wet environments table 3: least significant difference test for shear bond strength between the adhesive systems in dry and wet environments **=highly significant 0.05 ≥ p > 0.001 table 4: scores of the adhesive remnant index for the three adhesive systems in dry and wet environments, and the difference between them using fisher exact test group 1 vs. 4: fisher exact test= 0.0832, p-value= 0.003 **, d.f.=1 group 2 vs. 5: fisher exact test= 0.519, p-value= 0.03 *, d.f.=1 group 3 vs. 5: fisher exact test= 0.782, p-value= 1, d.f.=1 *= significant 0.05 ≥ p >0.01; **=highly significant 0.05 ≥ p > 0.001 material manufacturer components compositions resilience light cure adhesive (with an etchant agent and primer) orthotechnology; fl/usa), etching gel sealant resin (primer) paste bis-gma, glass filler, photosensitive catalyst tegdma, silane-treated quartz,amorphous silica, camphorquinone heliosit orthodontic adhesive (with an etchant agent and no primer) ivoclarvivadent clinical; schann/liechtenstein) etching gel translucent low viscosity paste urethane dimethacrylate,bis-gma, decadioldimethacrylate,silicon dioxide, catalysts, stabilizers beauty ortho bond (with selfetching primer) shofu, kyoto, japan primer a primer b paste salivatect water, acetone, others phosphoric acid monomer, ethanol tegdma, s-prg filler, bis-gma t-test (d.f.=18) wet environment bonding system dry environment bonding system p-value t-test sd mean max min sd mean max min .000** 7.92 0.648 9.02 10.01 8.01 group 4 (n=10) 0.744 11.48 12.81 10.32 group 1 (n=10) .000** 20.6 0.400 2.45 3.05 2.04 group 5 (n=10) 0.490 6.57 7.32 5.80 group 2 (n=10) .000** 22.7 0.300 6.39 7.03 5.98 group 6 (n=10) 0.563 10.97 11.73 10.06 group 3 (n=10) **=highly significant 0.05 ≥ p > 0.001 sig. f-test mean square d.f. anova sig. f-test mean square d.f. anova .000** 495.9 109.2 29 .000** 197.3 72.84 29 wet environment (se=0.209 ) dry environment (se=0.271 ) p-value mean difference groups p-value mean difference groups .000** 6.567 group 5 group 4 .000** 4.906 group 2 group 1 .000** 2.625 group 6 group 4 .075 0.503 group 3 group 1 .000** 3.942 group 6 group 5 .000** 4.403 group 3 group 2 wet environment dry environment ari score group 6 group 5 group 4 group 3 group 2 group 1 n (%) n (%) n (%) n (%) n ( %) n (%) 1.00(10) 2.00(20) 3.00(30) 1.00(10) 6.00(60) 8.00(80) 1 7.00(70) 0.00(0) 0.00(0) 8.00(80) 2.00(20) 2.00(20) 2 2.00(20) 8.00(80) 7.00(70) 1.00(10) 2.00(20) 0.00(0) 3 0.00(0) 0.00(0) 0.00(0) 0.00(0) 0.00(0) 0.00(0) 4 27. sarah f.doc j bagh college dentistry vol. 25(1), march 2013 bone density orthodontics, pedodontics and preventive dentistry 164 bone density determination for the maxilla and the mandible in different age groups by using computerized tomography (part i) sarah m. tewfiq, b.d.s. (1) hadeel a. alhashimi, b.d.s., m.sc. (2) abstract background: mini implant stability is primarily related to local bone density; no studies have evaluated bone density related to mini implant placement for orthodontic anchorage between different age groups in the maxilla and the mandible. the present research aims to evaluate side, gender, age, and regional differences in bone density of the alveolar bone at various orthodontic implant sites. materials and method: fifty three individuals who were divided into two groups according to their age into: group i (ages 16-20 years) and group ii (ages 21-29 years) had subjected to clinical examination, then 64-multislice computed tomography scan data were evaluated and bone density was measured in hounsfield unit at 102 points (51 in the maxilla and 51 in the mandible), and mean alveolar bone density was calculated at each site in the ct axial plane. results: no significant differences in bone density between the sides and gender were found. generally, the bone density measurements of group i and ii were not statistically different at almost most sites. the mean bone density of the alveolar cortical bone was greater in the mandible than in the maxilla and showed a progressive increase from the anterior to the posterior area, while in the maxilla the highest bone density was at the premolars region. the maxillary tuberosity was the region with lowest bone density. cancellous bone had almost comparable densities between the mandible and the maxilla and its density was less than those of cortical sites. conclusion: when mini implants are indicated, no gender and side differences affect the success rate regarding bone density; while age and area should be considered when selecting and placing mini implants for orthodontic anchorage. keywords: bone density, orthodontic mini implant, computerized tomography. (j bagh coll dentistry 2013; 25(1):164170). introduction goal of any orthodontic treatment is to achieve desired tooth movement with a minimum number of undesirable side effects. anchorage control is an important factor directly affecting the results of orthodontic treatment, mainly when maximum anchorage is necessary 1, 2. strategies have been made to develop suitable anchorage for successful orthodontic treatment. mini implants are clinical extra-dental intraoral anchorage systems that provide enhanced anchorage 3,4. regarding the failure rate of dental implants, which seems to be highly dependent on bone density as it was shown by jaffin and berman 5 who reported that it was 3% for types 1, 2, and 3 bone, but 35% for type 4 bone, according to bone quality as defined by lekholm and zarb. it was concluded that q1 bone experienced a failure rate greater than the q2 and q3 bones6. friberg et al reported that jaws with high bone density can experience overheating of the surgical sites during preparation without proper irrigation causing extensive bone necrosis which can result in subsequent implant failure during healing. this suggests that excessive bone density also might because of miniscrew loosening, whereas poor bone quality is certainly a risk factor for instability. (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad. therefore, data concerning density of the alveolar bone are essential for selecting sites for mini implant placement and predicting success7. however, there are not enough data, especially dealing with density of the alveolar bone in the dentulous areas in patients. generally, bone density is higher in the dentulous than edentulous bone and increases with decreasing inter-radicular distance. furthermore, bone density tends to decrease with increasing depth, particularly in the posterior area 8. factors affecting the success of dental and mini implants might be multifactorial. in the clinic, mini implants can loosen during orthodontic treatment, often in teenagers 9, 10 which suggest that age may be a primary risk factor associated with such failure. density of bone is a host factor that is known to play a crucial role in mini implant stability 11, 12. one method for measuring bone density appropriately and more precisely is computerized tomography (ct) 13,14. tomography is a generic term formed from the greek words tomo (slice) and graph (picture) that was adapted in by the international commission of radiological units and measurements in 1977 to describe all forms of body section radiography. ct has expediency and nondestructive nature and its images in dicom format contain data of bone density so that the software program can measure it 14. misch15 mentioned that the bone density measurements using ct provide more accurate j bagh college dentistry vol. 25(1), march 2013 bone density orthodontics, pedodontics and preventive dentistry 165 results than radiographic assessment. misch and kircos16expressed numerically the subjective bone density obtained mainly from experience and tactile sensation, and classified the bones into 5 categories according to density: d1>1250 hu; d2, 850-1250 hu; d3, 350-850 hu; d4, 150-350 hu; and d5<150 hu. the purpose of this study was to determine the bone density of the maxilla and the mandible for patients in different age groups with normal occlusion and compare the data according to the side, gender and site to supply a guideline for bone density when ct imaging is not possible so that orthodontic clinicians would not overlook some potentially important information. materials and method sample the total sample consisted of 53 iraqi subjects, 28 males and 25 females, with age range of 16-29 years old, collected from al-shaheed ghazi alhariri hospital.subject selection criteria included: 1. they have full set of permanent teeth in both jaws “excluding the 3rdmolar” 2. clinically skeletal class i, bilateral class i molar and canine relationships, with normal over jet and overbite and well-aligned arches. 3. subjects should have no large metal restorations (including crowns and fillings) that produce ‘‘scatter’’ and cause streak artifacts and affect the density of the adjacent bone tissue. 4. no history of general diseases, chronic regular use of medication that affect the bone density. 5. no previous or present regular tobacco smoking or alcohol drinking. 6. no history of dentofacial deformities, pathologic lesions in the jaws or facial trauma. 7. none of the subjects had received previous orthodontic and orthopedic treatment. materials and equipment a. disposable dental mirrors and probes and sliding caliper b. 64-multi-detector ct scanner (somatom definition as, siemens ag, germany, zuhr (ultra high resolution). c. siemens work station computer. d. syngovx2009b, image fusion(siemens ag imaging software multimodality reading, germany). method to measure the bone density of the alveolar bone, the axial plane was selected. the measurements were performed by the "threedimension view" to indicate the planned point in three planes of space at the same time, given that the location of any point in any plane will be changed at the same time in the three planes, consequently the appropriate slice in the wanted section can be matched by the slice serial number to be opened on the "viewing" mode, then all the desired points would be measured. for the alveolar bone 51 points for each jaw was measured, 24 points for each side and 3 points between the right and left central incisors, the buccal cortical bone, cancellous bone and palatal/lingual cortical bone between each two teeth (central incisor, lateral incisor, canine, first premolar, second premolar, first molar, second molar areas and tuberosity area in the maxilla and the retromolar pad area in the mandible) for both the left and right side in the male and female subjects were the bony sites of interest to perform the measurements. for the cortical bone, the center point of its thickness distal to the distal most surface of the tooth of interest was chosen 5 to 7 mm apical to the alveolar crest, the density of the cancellous bone was measured at the trabeculae, located halfway bucco-lingually between the buccal and palatal/lingual cortical plates of each tooth17. for the cortical bone distal to the second molar, 1 to 2 mm distal to the distal most surface of the distal root of the second molar, 5 to 7 mm from the alveolar crest ridge was the point of choice. for the cancellous bone, its density was measured at the trabeculae, located halfway buccolingually between the buccal and palatal/lingual cortical plate. forthe cortical bone of the maxillary tuberosity and mandibular retromolar pad areas, its center point was chosen 3 to 4 mm away from the distal most surface of the last molar root, 5 to 7 mm from the alveolar crest. for the cancellous bone, the density was measured at the trabeculae, located halfway bucco-lingually (figure 1). figure 1: measurement points on the alveolar bone of the maxilla and the mandible (a) on the buccal cortical bone (b) on the cancellous bone (c) on the palatal/lingual cortical bone j bagh college dentistry vol. 25(1), march 2013 bone density orthodontics, pedodontics and preventive dentistry 166 results bone density measurements are given according to misch’s16 classification (table 1). with this classification, the alveolar cortical bone in the maxilla was type 2 or 3 and for the mandible, the alveolar cortical bone was type 1and 2; whereas the density of the cancellous bone was type 3 and 4 in the maxilla and type 3 in the mandible in both groups. table 2 showed that although there were significant differences between the two age groups for the maxilla and the mandible in some points, there were no significant differences in the others. for the buccal cortical bone in the maxilla, the differences were present anteriorly; while for the mandible, the differences occurred posteriorly. regarding the alveolar cancellous bone, the differences occurred posteriorly in both the maxilla and the mandible. for the maxillary palatal cortical bone, there were no significant differences between both groups; yet there were significant differences between the groups in the mandible except the point between the central incisors and the point distal to the canine. when comparing the buccal cortical bone in the maxilla and the mandible, the mandible was denser than the maxilla in both groups except the point distal to the maxillary central incisor at which there was statistically no significant difference. for the cancellous bone, the mandible tended to be denser than the maxilla but statistically there was no significant difference anteriorly in both groups. for palatal/lingual cortical bone there were significant differences between the maxilla and the mandible except the points between two centrals and central/lateral in group i and the points between two centrals and first/second premolars in group ii which show no significant difference (table 3). discussion in the present study the interradicular spaces were the areas of interest since they are generally the site of choice for mini implant placement for their ease of access, simplicity of procedure, and less traumatic placement 18.the results of the present study indicate that there were no significant differences between the right and left sides for all measured variables for both genders and in both groups. therefore, all comparisons were performed with combined data. this could be supported by the observations of bilateral symmetry in bone density in the same anatomic sites that was reported for animal studies of rhesus monkey19. this investigation found no significant gender differences in the bone density which is in agreement with others 8,17,20. this result can be explained by the presence of estrogen hormone in higher levels in the female subjects compared to the male subjects which is compensated by the exercises exerted by the males and the different chewing patterns. however other studies 21,22 showed that adult females had significantly greater cortical bone density than adult males did, this is in conflict with the finding of the present study suggesting that the presence of gender difference may be dependent on the different specific sites being examined in the bone or due the ct scanning machine setting being used. this study showed that the differences in bone density between group i and ii were not statistically different at almost most sites. the age range for successful implantation is a matter of controversy. this study covered a broad age range, from 16 to 29 years since orthodontic treatment is mostly applied in that age. during childhood and adolescence, a bone mass increase till a plateau is reached between 18 and 23 years 23. also, in both gender, a large variance in bone density is observed among healthy individuals at the beginning of the third decade 24.the age differences can be attributed to the normal bone physiology and histology 25 and by changes in functional capacity, because maximum bite forces, masticatory muscle size, and muscle activity all tend to increase with age considering that muscle conditioning has a positive effect on bone density 26. it was found that the maxillary buccal cortical alveolar bone at the canine and the premolars area has the highest bone density and the maxillary tuberosity area was found to have lowest bone density, these variations may be partly explained by the different anatomic characteristics in these areas 27. in the present study, the bone density showed increase from the anterior to the posterior area in the mandible, this pattern might be explained by the higher functional demands placed on the posterior teeth since they receive two thirds of the occlusal loads 28 and by the increase in the longitudinal elastic modulus between the molar region and the symphysis 29. in this study there is a general observation that the density of the cancellous bone is less than that of cortical bone which may be attributed to the fact that the cancellous bone forms a trabecular network pierced by many small blood vessels, lymphatic vessels, and nerves. these elements will reduce the amount of the basic chemical in bone, calcium phosphate, which gives bone its hardness and strength 30. the bone density of the present study was compared between the maxilla and the mandible on the buccal and lingual sides of cortical bone and for the cancellous bone. j bagh college dentistry vol. 25(1), march 2013 bone density orthodontics, pedodontics and preventive dentistry 167 however, the mandible tended to be denser than the maxilla on both groups and all the mandibular posterior sites showed statistically greater bone densities while the differences in the anterior areas mostly were not significant especially in the cancellous bone. these results agree with other previous studies8,17,31. concerning bone density differences between the maxilla and the mandible, it might be associated with the different biomechanical functions: the mandible is a force absorption unit; while the maxilla is a force distribution unit hence the maxilla has a thin cortical palate and fine trabecular bone 14. moreover, the obtained data of the present study may serve as tips for selecting the most suitable areas during mini implants installation and give clinicians, for the first time, reference data for clinical assessments of bone density for iraqi subjects, both within and between ages and both within and between regions in human maxilla and mandible. finally, it remains pertinent to be aware of the attendant risk of computed tomography, which continues to impart a higher radiation dosage compared to conventional radiographs, but to weigh this against the power of the diagnostic information that it can provide. references 1. angle eh. treatment of malocclusion of the teeth. 7th ed. philadelphia: w.b. saunders company; 1907. 2. proffit wr, fields hw, sarver dm, ackerman jl. contemporary orthodontics. 5th ed. st. louis: mosby elsevier; 2013. 3. mcnamara ja jr. implants, microimplants, onplants and transplants: new answers to old questions in 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steele j, nohl f. applied occlusion. london: quentessence publishing, 2008. 29. van eijden tm. biomechanics of the mandible. crit rev oral biol med 2000; 11(1):123-36. 30. clarke b. normal bone anatomy and physiology. clin j am soc nephrol 2008; 33 (4 suppl):s131-9. 31. borges ms, mucha jn. bone density assessment for mini-implants position. dental press j orthod 2010; 15(6): 58.e1-9. table 1: distribution of bone density according to misch’s classification in the maxilla and the mandible site bone group 1-1 1-2 2-3 3-4 4-5 5-6 6-7 7 tuberosity/ retromolar pad areas m a x il l a buccal cortical group i 3 2 2 2 2 2 2 2 3 group ii 3 2 2 2 2 2 2 2 3 cancellous group i 3 3 3 4 4 4 3 3 4 group ii 3 3 3 4 4 4 3 3 4 palatal cortical group i 2 2 2 2 2 2 2 2 3 group ii 2 2 2 2 2 2 2 2 3 m a n d ib l e buccal cortical group i 2 2 2 2 2 1 1 1 1 group ii 2 2 2 2 1 1 1 1 1 cancellous group i 3 3 3 3 3 3 3 3 3 group ii 3 3 3 3 3 3 3 3 3 lingual cortical group i 2 2 2 2 1 1 1 1 1 group ii 2 2 2 2 2 1 1 1 1 j bagh college dentistry vol. 25(1), march 2013 bone density orthodontics, pedodontics and preventive dentistry 169 table 2: comparison between the groups in the alveolar buccal cortical, cancellous and palatal/lingual cortical bones of the maxilla and the mandible buccal cortical cancellous palatal/lingual cortical points groups descriptive statistics p-value descriptive statistics pvalue descriptive statistics pvalue mean s.d mean s.d mean s.d m a x il l a 1-1 i 829.10 98.47 0.59 (ns) 411.13 118.05 0.73 (ns) 755.96 74.54 0.75 (ns) ii 840.35 75.85 399.90 138.55 878.11 74.86 1-2 i 1006.85 113.43 0.004 (hs) 420.12 121.17 0.76 (ns) 1119.62 124.32 0.79 (ns) ii 1076.24 74.11 412.22 133.99 1126.25 72.12 2-3 i 885.05 95.65 0.006 (hs) 409.84 123.16 0.84 (ns) 1004.48 94.49 0.36 (ns) ii 948.21 84.46 404.42 123.83 1029.43 108.66 3-4 i 1051.27 103.37 0.38 (ns) 330.10 98.63 0.84 (ns) 1168.01 120.77 0.39 (ns) ii 1072.70 87.37 347.20 95.93 1138.16 120.25 4-5 i 1123.83 112.74 0.14 (ns) 300.35 93.45 0.08 (ns) 1217.47 112.06 0.96 (ns) ii 1164.51 102.04 342.35 83.80 1218.71 83.59 5-6 i 1126.30 116.14 0.52 (ns) 319.81 95.48 0.70 (ns) 1218.95 112.97 0.72 (ns) ii 1144.81 109.62 339.56 87.38 1209.02 90.55 6-7 i 976.24 81.15 0.06 (ns) 408.81 101.72 0.76 (ns) 1066.30 95.60 0.30 (ns) ii 1016.35 79.38 401.37 84.67 1085.41 65.02 7 i 961.21 87.10 0.06 (ns) 418.53 100.59 0.52 (ns) 1037.42 90.60 0.11 (ns) ii 1002.54 83.55 401.61 97.08 1073.05 70.01 tuberosity area. i 500.64 85.48 0.11 (ns) 239.07 102.54 0.01 (s) 602.29 110.70 0.66 (ns) ii 546.30 119.43 190.07 54.95 615.11 99.03 m a n d ib l e 1-1 i 895.88 89.96 0.98 (ns) 427.43 99.83 0.47 (ns) 904.62 98.01 0.72 (ns) ii 895.31 98.84 405.14 122.94 894.95 92.57 1-2 i 1031.94 104.36 0.87 (ns) 437.18 101.61 0.52 (ns) 1134.61 93.92 0.001 (hs) ii 1036.13 82.84 418.21 104.72 1028.90 91.98 2-3 i 1087.05 105.53 0.81 (ns) 465.12 100.55 0.14 (ns) 1187.38 92.54 0.001 (hs) ii 1094.01 99.13 422.64 110.97 1080.91 108.49 3-4 i 1167.07 92.97 0.06 (ns) 480.34 92.73 0.06 (ns) 1240.18 91.06 0.38 (ns) ii 1214.69 85.98 426.58 107.46 1216.07 105.86 4-5 i 1228.04 85.58 0.07 (ns) 486.35 109.85 0.054 (ns) 1295.89 90.43 0.048 (s) ii 1277.19 94.31 428.00 122.88 1242.97 93.91 5-6 i 1298.57 82.66 0.68 (ns) 501.56 108.94 0.09 (ns) 1338.10 94.20 0.02 (s) ii 1309.94 101.79 427.03 115.54 1272.85 86.32 6-7 i 1400.75 99.67 0.02 (s) 509.96 114.03 0.04 (s) 1424.83 99.37 0.024 (s) ii 1475.58 105.37 436.73 112.64 1364.87 75.64 7 i 1428.58 93.28 0.01 (s) 520.00 113.76 0.008 (hs) 1442.99 90.76 0.007 (hs) ii 1505.88 109.79 428.56 129.94 1369.64 87.48 retromolar pad area. i 1467.37 103.70 0.009 (hs) 512.72 111.06 0.012 (s) 1435.77 76.67 0.001 (hs) ii 1549.42 108.94 427.86 109.5 1344.92 100.15 p > 0.05 ns non-significant p ≤0.05 s significant p ≤0.01 hs highly significant j bagh college dentistry vol. 25(1), march 2013 bone density orthodontics, pedodontics and preventive dentistry 170 table 3: difference between the maxilla and mandible regarding the alveolar buccalcortical, cancellous and palatal/lingual cortical bone in both groups buccal cortical cancellous palatal/lingual cortical group i group ii group i group ii group i group ii point jaw mean s.d p-value mean s.d pvalue mean s.d pvalue mean s.d pvalue mean s.d pvalue mean s.d pvalue 1-1 max. 829.10 98.47 0.03 (s) 840.35 75.85 0.02 (s) 411.13 118.05 0.63 (ns) 399.90 138.55 0.87 (ns) 870.92 104.54 0.29 (ns) 878.11 74.86 0.43 (ns) man. 895.88 89.96 895.31 98.84 427.43 99.83 405.14 122.94 904.62 98.01 894.95 92.57 1-2 max. 1006.85 113.43 0.46 (ns) 1076.24 74.11 0.045 (s) 420.12 121.17 0.62 (ns) 412.22 133.99 0.84 (ns) 1119.62 124.32 0.66 (ns) 1126.25 72.12 0.000 (vhs) man. 1031.94 104.36 1036.13 82.84 437.18 101.61 418.21 104.72 1134.61 93.92 1028.90 91.98 2-3 max. 885.05 95.65 0.000 (vhs) 948.21 84.46 0.000 (vhs) 409.84 123.16 0.12 (ns) 404.42 123.83 0.54 (ns) 1004.48 94.49 0.000 (vhs) 1029.43 108.66 0.05 (s) man. 1087.05 105.53 1094.01 99.13 465.12 100.55 422.64 110.97 1187.38 92.54 1080.91 108.49 3-4 max. 1051.27 103.37 0.000 (vhs) 1072.70 87.37 0.000 (vhs) 330.10 98.63 0.000 (vhs) 347.20 95.93 0.003 (hs) 1168.01 120.77 0.04 (s) 1138.16 120.25 0.008 (hs) man. 1167.07 92.97 1214.69 85.98 480.34 92.73 426.58 107.46 1240.18 91.06 1216.07 105.86 4-5 max. 1123.83 112.74 0.002 (hs) 1164.51 102.04 0.000 (vhs) 300.35 93.45 0.000 (vhs) 342.35 83.80 0.002 (hs) 1217.47 112.06 0.02 (s) 1218.71 83.59 0.28 (ns) man. 1228.04 85.58 1277.19 94.31 486.35 109.85 428.00 122.88 1295.89 90.43 1242.97 93.91 5-6 max. 1126.30 116.14 0.000 (vhs) 1144.81 109.62 0.000 (vhs) 319.81 95.48 0.000 (vhs) 339.56 87.38 0.000 (vhs) 1218.95 112.97 0.001 (hs) 1209.02 90.55 0.005 (hs) man. 1298.57 82.66 1309.94 101.79 501.56 108.94 427.03 115.54 1338.10 94.20 1272.85 86.32 6-7 max. 976.24 81.15 0.000 (vhs) 1016.35 79.38 0.000 (vhs) 408.81 101.72 0.004 (hs) 401.37 84.67 0.16 (ns) 1066.30 95.60 0.000 (vhs) 1085.41 65.02 0.000 (vhs) man. 1400.75 99.67 1475.58 105.37 509.96 114.03 436.73 112.64 1424.83 99.37 1364.87 75.64 7max. 961.21 87.10 0.000 (vhs) 1002.54 83.55 0.000 (vhs) 418.53 100.59 0.004 (hs) 401.61 97.08 0.35 (ns) 1037.42 90.60 0.000 (vhs) 1073.05 70.01 0.000 (vhs) man. 1428.58 93.28 1505.88 109.79 520.00 113.76 428.56 129.94 1442.99 90.76 1369.64 87.48 tuberosity/ retromolar pad areas max. 500.64 85.48 0.000 (vhs) 546.30 119.43 0.000 (vhs) 239.07 102.54 0.000 (vhs) 190.07 54.95 0.000 (vhs) 602.29 110.70 0.000 (vhs) 615.11 99.03 0.000 (vhs) man. 1467.37 103.70 1549.42 108.94 512.72 111.06 427.86 109.5 1435.77 76.67 1344.92 100.15 rabeia.doc j bagh college dentistry vol. 27(2), june 2015 early and delayed restorative dentistry 24 early and delayed effect of 2% chlorhexidine on the shear bond strength of composite restorative material to dentin using a total etch adhesive rabeia j. khalil, b.d.s. (1) abdulla m.w. al-shamma, b.d.s., m.sc., ph.d. (2) abstract background: lack of durability of the bond of the dental adhesive systems to tooth structure is one of the most important problems in tooth colored restorative work. this in vitro study was performed to evaluate the effect of 2% chlorhexidine gluconate(chx) on dentin bond strength by using total etch adhesive system at twenty-four hours and three months of water storage. material and methods:a flat dentin surface was prepared for forty sound human maxillary premolar teeth which were acid etched with 36% phosphoric acid gel after being divided randomly into four groups of ten teeth each according to storage time and chx application, thechx was applied for 60 seconds before adhesive application for groups i and iii which were tested after twenty-four hours and three months respectively, while the distal water was applied for 60 seconds before the application of adhesive for group ii and iv which were tested after twenty-four hours and three months respectively.the prime and bond® nt™ adhesive (dentsply) was applied and cured, composite (ceram x mono, dentisply) was applied through special mold with 2 mm thickness and light cured, then all specimens were stored in distilled water 37oc until the time of testing of each group.shear bond strength test was performed at the end of the storage period (24 hours or 3 months). results:t-test results showed high statistically significant reduction in shear bond strength (sbs) in non chx group iv (tested after 3 months) compared to non chx group ii (tested after 24 hours)(p< 0.01). in chx groups i (tested after 24 hours) and iii (tested after 3 months), results showed no statistically significant differences in shear bond strength(p> 0.05).on the other hand result showed statistically no significant differences between groups i and ii in 24 hours shear bond strength (p> 0.05). after 3 months water storage, there was statistically high significant differences between the groups iii and iv (p< 0.01). conclusion: the use of 2 % chx glocounate solution after acid etching and before bonding of dentin have no adverse effect on immediate bond strength (24 hours storage), and was effective in reducing degradation of resindentin bond interface after three months of water storage. keywords: 2% chlorhexidine, shear bond strength, composite, total-etch adhesive. (j bagh coll dentistry 2015; 27(2):24-31). introduction the advance of adhesive systems contributed to new possibilities in clinical dentistry, this including the conservation of the dental substrate. the intimate attachment in dentin was very difficult to achieve and also difficult to accomplished, and this due to the fact that dentin contains significant amount of organic material and water, also dentin is porous and wet biological structure composed of hydroxyapatite crystals which embedded in proteinaceous matrix which include type i collagen. the formation of the hybrid layer started with the polymerization of monomers in the adhesive and it include a mixture of the resin, water, collagen and the hydroxyapatite crystals which bond the resin restoration to the dentin structure (1) at the bonding interface there will be a hybridized tissue formation, but the etch-and-rinse have their bonding ability compromised over time, both in vivo (2) and in vitro (3). (1) master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. despite the evolution of adhesive systems, the major problems was that over time, there was a degradation of dentin and hybrid layercausing early loss of bond strength, thus influencing the clinical longevity of restoration (4). this degradation associated with (5): 1. some monomers are hydrophilic in its nature and this monomers inter in the dentin adhesives composition. 2. the totaletch adhesive associated with moist-bonding or wet-bonding technique. 3. the presence of fluid filled tubules in the anastomoses which permeate the dentinaltubules. the degradation of collagen fibrils at the bottom of and in the hybrid layer has been shown to occur during a period of storage due to two main facts, the first one is that the diffusion of resin monomer into the demineralized dentin shows a decreasing concentration gradient and this result in unprotected collagen fibrils which present at the bottom of the hybrid layer (6). the second fact, is that the water play very important role in the decreasing of the physical properties of adhesive polymers over time because of partial hydrolytial degradation effect j bagh college dentistry vol. 27(2), june 2015 early and delayed restorative dentistry 25 of water. the plasticization of adhesives occurred due to water absorption over time resulted in a lower bonding strength (7). thus, the degradation of the exposed collagen by collagenolytic host – derived enzymes, such as dentin matrix metalloproteinase (mmps), which are a family of zinc and calciumdependent endopeptides that are capable of degrading most of the components of the extracellular matrix (ecm), is another factor associated with decreased longevity of restorations (8). protease inhibitors as additional primers might be recommended to inhibit the intrinsic collagenolytic activity of human dentin, to reduce the aging of bonding interfaces and to increase the stability of the dentinal collagen fibrils within the hybrid layer. this is essential in dentin bonding and may be achieved by inhibiting activated hostderived dentin enzymes which are liable for the breakage of dentin collagen fibrils without bacteria; therefore, the application of some specific mmp inhibitors which can suppress dentin collagenolytic and gelatinolytic activities such as edta (ethylene diaminetetraacetic acid), galardin, tetracyclines, green tea polyphenols, especially epigallocatechin gallate (egcg) and chlorhexidine (chx), which act as abroadspectrum antimicrobial agent used widely in the treatment of oral disease, chx has been found to have desirable mmpinhibition properties (mmp-2, -8 and -9) even at low concentrations which result possibly resulting from its zn2+cation-chelating property and cysteine cathepsins inhibition(9). the dentin collagen degradation activity can be reduced through the use of 2% chx on the dentin surface after the application of phosphoric acid, when a layer of denuded collagen is exposed (10, 11) . materials and method sample forty extracted, sound human maxillary first premolar teeth extracted for orthodontic purpose (the patient age range from 18 to 22 years) of comparable size and shape were selected and collected from different health centers and used for this study. the teeth were stored in 0.1% thymol solution for 48 hours (12), then in deionized distilled water at 37 oc (13),teeth storage lasted for a maximum of three months before samples were chosen for the study.during all stages of the study, dehydration of the specimens was avoided (14) .the teeth selected were free from cracks and caries and were sound when examined by transillumination using the fiber optic of the light curing unit and by magnifying lens (10x) and approximately had similar crown size, if cracks present, such teeth were excluded from the sample. the forty sound teeth were cleaned from debris by using slurry of pumice in a rubber cup with low speed hand piece, and then washed with distilled water (15). the teeth were mounted in self-cured acrylic resin by using specially designed rubber mold. a flat surface for bonding was obtained by cutting the buccal and palatal cusps.the sectioning was done by a sectioning device and using of diamond cutting disk (with continuous cooling by distilled water spray)as shown in figure (1). a standardized length of abrasive paper (600 grit) 10 cm length were fixed on a flat table. the occlusal surface of each tooth then were ground against the flat wet surface of abrasive paper. each surface were four times ground and the occlusal surface of all teeth were observed visually using device and checking for the presence of any remnant enamel as shown in figure (2). a b figure 1: sectioning device figure 2: abrasive paper method the selected forty teeth, were randomly divided into four groups of ten teeth each according to the time of storage and chx application: j bagh college dentistry vol. 27(2), june 2015 early and delayed restorative dentistry 26 group i: 10 teeth treated with 2% chx for 60 seconds prior to adhesive application and was tested after 24hours, group ii: 10 teeth treated with distilled water for 60 seconds prior to adhesive application and was tested after 24hours, group iii: treated with 2% chx for 60 seconds prior to adhesive application and was tested after 3 months, group iv: 10 teeth treated with distilled water for 60 seconds prior to adhesive application and was tested after 3 months. the exposed surfaces (dentin only) was etched by using specially designed sticking paper(4 mm hole diameter) which was positioned on the ground dentin surface to demarcate the bonding region (16) , then the exposed dentin surface was etched with using the total etch technique with 36% phosphoric acid gel for 15 seconds as manufacturer's instructions, the surface was rinsed with water for 20 second, excess water was removed by the application of a gentle stream of air for 2 seconds at a distance of approximately1cm(17),(standardization was confirmed by keeping the air syringe away from the acrylic block that hold the tooth by 1 cm using two handles parallel to each other , one of the handles grasped the air syringe , the other carried the acrylic block)(18) .after etching and dryness, the dentin surfaces in groups i and iii were rewetted by application of 2% chlorhexidine gluconate by rubbing the exposed dentin surface for 60 seconds with disposable brush tip, while in groups ii and iv the detected dentin surface were rewetted by rubbing the exposed dentin surface for 60 seconds with distilled water by using of disposable brush tip , then excess solution was removed with absorbent paper, prime &bond® nt™ adhesives (dentsply, germany) used with total etch technique according to the manufacturer's instruction. two coats of adhesive applied by using of disposable brush tip, then gentle blowing of adhesive for 10 seconds at 20 cm by using of triple syringe for solvent evaporation (17,19,20) (standardization was confirmed by keeping the air syringe away from the acrylic block that hold the tooth by 20 cm using two handles parallel to each other, one of the handles grasped the air syringe, the other carried the acrylic block)(18). the adhesives were light cured with a led light curing unit (sdi, australia) with a power intensity of 600 mw/cm2for 10 seconds according to the manufacturer's instruction. the composite resin restoration ceram x-mono from (dentsply, germany) was applied according to manufacturer instruction and using a mold especially designed for standardization of composite application, this mold was custom made from teflon material and consists of different parts. it has a cylindrical shape to facilitate the easy insertion of acrylic block, the upper part of mold consist of two removable parts fixed to the body of the mold by two screws forming a hole in the center which has a diameter of 4 mm and 2 mm height for application of composite in a standardized manner as shown in figure (3). a b figure 3: teflon mold the restorative material (ceram x mono dentsply, germany) was applied by using plastic instrument in a single increment to the height of the hole (2mm) of the mold. so the material were positioned vertically exactly on the bonding site through the hole. after packing of composite in the mold celluloid strip was placed under two mm thickness glass slide and pressed under a load of 200gm for 1 minute. the excess material was then removed (21). the material was light cured for 20 seconds with the tip of the lightcuring unit (sdi, australia) placed in an intimate contact with overlying celluloid strips for all samples (17). all the samples were stored in a deionized distilled water within a dark container at37 oc before bond strength testing, the groups i and group ii were stored for 24 hours, while groups iii and iv were stored for 3 months. the samples were tested for shear bond test with laryee universal testing machine (china) using a stainless steel chisel-shaped rod with across head speed 1 mm/min (20). the specimen was stressed to get failure by laryee machine j bagh college dentistry vol. 27(2), june 2015 early and delayed restorative dentistry 27 (figure 4). the force then was recorded in newton, which then divided by the surface area (12.56mm2) to obtain the sbs calculated in mpa (n/mm2) (22).data obtained were analyzed statistically using one way anova test and student t-test. anova test results revealed statistically highly significant differences among the groups. figure 4: laryee testing machine. results the means and standard deviations of sbs with minimum and maximum values which were calculated for each group are shown in table(1) and figure (4). the results showed that the lowest mean of sbs was scored by group 4 (without chx 3months) (2.4160 ± 0.46294 mpa) while the highest mean belonged to group 1(chx 24 hours) (4.6020 ± 0.97708mpa). there was no statistically significant differences in the immediate sbs (p>0.05) between the group i and group ii , after three months storage in distilled water, the sbs of group iii (chx 3 months) was higher than group iv (without chx 3months) (p<0.01). in non chx groups, sbs after three-month storage in the distilled water was significantly lower than the immediate sbs (p<0.01) table. however, there was no significant differences in the sbs of immediately and after three-month storage of chx groups (p>0.05) all previous results shown in table (2). the results of failure mode were displaced in the table (3). by using the magnifying lens (10x)the results were in twenty-four hours groups showed mostly mixed mode of failure with high percentage, the group iii treated with chx the adhesive failure slightly increased compared with group i and group ii, on the other hand the group vi treated with distilled water showed high percentage of adhesive failure. table 1: the means and standard deviations of sbs groups n mean sd min max group i (chx 24hrs) 10 4.6020 .97708 3.00 5.40 group ii (without chx 24hrs) 10 4.4080 .97881 3.08 5.92 group iii (with chx 3months) 10 4.1020 .95086 3.00 5.64 group iv (without chx 3months ) 10 2.4160 .46294 1.43 3.04 table 2: ttest among different groups groups sd t sig. chx.24hrs without.24hrs 1.34722 .455 .660 chx.24hrs chx.3m 1.42930 1.106 .297 without.24hrs –without chx.3m 1.21845 5.170 .001 chx.3m without.3m 1.25773 4.239 .002 table 3: mode of failure (%) observed in shear bond strength (mpa) among studied groups. mode of failure (%) studied groups combined ( type ii) adhesion (type i) 80 20 group i 70 30 group ii 60 40 group iii 10 90 group iv discussion in this in vitro study application of 2% chx after etching and before the application of the adhesive resin had "no adverse effect on immediate-bond-strength" and this agree with (19, 23, 24, 25, 20), and this may be due to most of adhesives have good properties which may counteract the polymerization shrinkage, and in the result act on increasing the strength of the hybrid layer which resulted in high immediate sbs(26).also the moist-bonding strength used with total-etch adhesives preserve the porosity of the collagen network which support the collagen fibrils and resulted in good resin monomers diffusion into the nano-spaces of the collagen network (27). j bagh college dentistry vol. 27(2), june 2015 early and delayed restorative dentistry 28 figure 5: bar-chart of mean shear bond strength values among groups however, the result of this study disagrees with (28), who found that in vitroit is contraindicated to apply chx with a concentration greater than 0.12% prior to application of primer because it may cause a significant drop in bond strength during first 24 hours. also this result disagrees with (29), who showed that chx may result in the drop in the bond strength and lead to increasing in the microleakage because it may interfere with the bonding procedure. also the chx could bind to the phosphate groups of the apatite either on the dentin surface or in the smear layer due to its cationic properties, so it might affect negatively on the infiltration of resin. although there is no statistically significant differences between group i and group ii, but the results showed that the mean sbs slightly higher than the group ii (without chx ) and this result agree with (30),this superiority of chx group could be attributed to certain chx properties, including strong positive ionic charge; ready binding to phosphate groups; strong affinity to the tooth surface, which is increased by acid etching and, finally, an increase in surface-free energy of dentin, are the likely reasons responsible for the good resin-dentin bond strengths obtained when chx is applied after acid etching (31). when comparing the group iii (chx 3 months) with group iv (without chx 3months) it has been found that there is highly significant differences in mean sbs between them, group iii maintained its bond strength after 3 months with little decrease in bond strength ,but bond strength of group iv significantly decreased and this result comes in agreement with other findings (3,6,7,10,17,20,23,32), for etch-and-rinse adhesives, the diffusion of resin monomer into the demineralized dentin shows a decreasing concentration gradient. this results in water filled interfibrillar spaces with unprotected and vulnerable collagen fibrils at the bottom of the hybrid layer. they may be structurally unstable owing to the absence of resin protection within the hybrid layer over time, resulting in reduced long-term bond strength. they may also become the sites for collagen hydrolysis by host-derived matrix metalloproteinase (mmps) enzymes using chx after acid-etching preserve both durability and bond strength of the hybrid-layer of in vitro aged due to chx may: 1. prevent exposed collagen within dentin bonds from degradation by activated mmps, thereby improving its longevity (10, 19). 2. as long as the mmps are zinc-calcium dependent enzymes (33,34, 35), the chx demonstrates beneficial anti proteolytic properties, and they proposed two different mechanisms of action involved in mmps inhibition: a chelating mechanism of zinc or calcium ions for inhibition of mmp-2 and -9, the chx in the case of mmp-8 interact with the cysteine and/or the essential sulfhydryl groups which present in its active site (9). 3. a positively charged molecules release from dentin treated with chx and its ability to adsorb to the surfaces of the oral cavity (36), this ability to adsorb to the surfaces of the oral cavity can also be the same for collagen fibrils, which probably preserves degradation of the hybrid layer after long-term water exposure. by comparing the group ii (without chx 24 hrs.) and group iv (without chx 3months), we found statistically highly significant differences in mean sbs between two groups that indicate the loss both of durability of hybrid layer and bond strength over time. the result of this study comes in agreement with the many studies (8, 37-40), the loss of durability and bond strength may be due to a) the plasticization of the adhesive might occur j bagh college dentistry vol. 27(2), june 2015 early and delayed restorative dentistry 29 with time due to water absorption which lead to hydrolytical degradation of unreacted adhesive monomers, which in turn leads to decrease of bonding strength over time, such polymers undergo decreasing in the physical properties as a result of sorption of the water after polymerization and the extraction of these unreacted and water soluble monomers and decrease its concentration over time , the elution of resin from hydrolytically unstable polymers inside the hybrid layer may also cause exposure of the collagen fibers. these newly exposed fibrils, along with the collagen fibrils not fully enveloped by resin monomers during the bonding protocol, are vulnerable to mechanical and hydrolytical fatigue as well as degradation by collagenolytic enzymeswhich may compromise the integrity of dentin–resin bonds (27, 32).during water storage the adhesive sorption leading to swelling and softening in the net wok of the polymeric network, and reduction in the friction force between the polymeric chains which lead to releasing of unreacted monomers trapped in this chins to the storage solution which leads to saturation of storage solution ,and producing of dynamic equilibrium between undissolved solute and the solution ,and this very important for stability of degradation and bond strength over time during storage in this study, so the storage solution was not changed during storage period (41). b) the deterioration of the resin-dentin bond strength interface could be attributed to the effect of water storage that result in the break-down of uncovered collagen fibrils beneath the hybrid layer(4). c) human dentin contains at least collagenase (mmp-8), gelatinases mmp-2 and -9, mmps are class of zinc-calcium depended endo peptidases are trapped within the mineralized dentin matrix during tooth development, this mmps bound to collagen matrix are covered at this stage with apatite crystals which is extrafibrlar and intrafibrillar crystallites, in mineralized dentin and before of acid-etching, these mmps are fossilized and inactive. several mechanisms have been suggested for activation of mmps, the most important one according to this in vitro study is decrease in ph value by etchrinse adhesive (33-35), low ph value was suggested to cause a conformational change within the pro peptide domain which block the zn+2ions binding site of the enzyme that facilitate the cysteine switch, a critical step in the activation process (33).after superficial demineralization by using a 37% phosphoric acid, both extrafibrillar and intrafibrillar crystallites removed that lead to uncover of matrix-bond mmps and activating them, allowing slowly attacking and degrading of the unprotected collagen fibrils at the bottom of hybrid layer, these unprotected fibrils are created due to decrease gradient of monomer impregnation of the fibers with the depth that mean the base of hybrid layer is less infiltrated with resin leading to zones of un infiltrated collagen network in the hybrid layer (40). d) the presence of water regards an obligatory requirement for the action of mmps and for degradation process to occur, because no loss of dentin-adhesive bond strength with time when mineral oil was used as a storage medium instead of water, in etch and rinse adhesive, the water is present both in intra and extrafibriller collagen compartment, in this type of adhesive, a waterfilled collagen network is created due to rinse after etching, also due to using of the moist – bonding technique which is very important to prevent the collagen fiber collapse because of dryness, so the dentine must be fully hydrated, so the collagenase were firstly occuerd by mmp-8 by adding the water across the specific peptide bonds in the collagen, then by the presence of water the gelatinases mmp-2 and 9 digest of unprotected collagen fibers resulting in degradation of resin-dentin interfaces (8,19,40). e) at a low ph during etching procedure, the cysteine capthesin enzyme activated and acted on degrade the uncovered collagen fibrils over time (42). the comparison between group i (chx 24hrs) and group iii (chx 3months) revealed that the group iii preserved both the bond strength and the durability of the hybrid layer of aged specimens in vitro and according to the distribution of mode of failure. also there is a high correlation between this result and many of in vivo study including same methodology (10), the most logical and acceptable explanation of this result was the inhibition of dentin-matrix-bound mmps(9), which resulted in the preservation of integrity of the denuded or uncoverd collagen fibrils and the overlying hybrid layer. so the chx agent act on improve and increase the bond strength and the integrity of hybrid layer over time, and this was very clear when compared with the group iv (without chx 3 months). the proportional reduction of the mean bond strength might be due to the hydrolytic degradation of the adhesive polymer compared to the initial value of mean bond strength of group i (43). also the bond reduction of group iii was in agreement with others (22,24), who showed that the hydrolytic degradation regard one of most important factors that resulted in decreases durability of bond strength over time. the unreacted or uncured hydrophilic monomer that j bagh college dentistry vol. 27(2), june 2015 early and delayed restorative dentistry 30 are present in the adhesive systems (to increase the dentin surface energy) leach out because of water and lead to reduction in the bond strength over time. these kinds of extrinsic degradation of the resin-dentin interface, which originate in the adhesive above the hybrid layers, take place over time. it is widely accepted that the marketed resin adhesives contain high concentrations of ionic and hydrophilic resin monomers to enable bonding to wet dentin substrates, and to etch and bond simultaneously enamel and dentin they may produce permeable unstable resin matrices that are liable to water sorption, resin leaching and hydrolysis over time (44). references 1. van meerbeek b, inokoshi s, braem m, lambrechts p, vanherle g.morphological aspects of the resindentin interdiffusion zone with different dentin adhesive systems. j dent res 1992; 71:1530–40. 2. van meerbeek b, yoshida y, lambrechts p, vanherle g, duke e, eick jd, robinson sj. atem study of two-based adhesive systems bonded to dry and wet dentin. j dent res 1998; 77: 50-9. 3. de munck j, van landuyt k, peumans m, poitevin a, lambrechts p, baem m, van meerbeek b. a critical review of the durability of adhesion to tooth tissue, j dent res 2005; 84(2):118-41. 4. de munck j, van meerbeek b, lambrechts p, vanherle g. four-year water 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in root canal dentin. j oral surg oral med oral pathol oral radiol endod 2004; 98(4): 488-92. 37. hashimoto m, tay fr, ohno h, sano h, kaga m, yiu c, kumagai h, kudou y, kubota m, oguchi h. sem and tem analysis of water degradation of human dentinal collagen. j biomed mater res b appl biomater 2003; 66: 287-98. 38. hashimoto m, ohno h, sano h, kaga m, oguchi h. in vitro degradation of resin-dentin bonds analyzed by microtensile bond test, scanning and transmission electron microscopy. biomaterials 2003, 24: 3795805 . 39. mazzoni a, pashley dh, nishitani y, breschi l, mannello f, tjäderhane l, toledano m, pashley el, tay fr. reactivation of inactivated endogenous proteolytic activities in phosphoric acidetched dentin by etch and – rinse adhesives. biomaterials 2006; 27: 4470-6. 40. pashley dh, tay fr, imazato s.how to increase the durability of resin-dentin bonds. compend contin educ dent 2011; 32(7): 60-4, 66. 41. skovron l, kogeo d, gordillo la, meier mm, gomes om, reis a, loguercio ad. effects of immersion time and frequency of water exchange on durability of etch-and-rinse adhesive. j biomed mater res b appl biomater 2010; 95(2): 339-46 42. nascimento fd, minciotti cl, geraldeli s, carrilho m r, pashley d h, tay fr, nader hb, salo t, tjäderhane l, tersariol il. cysteine cathepsins in human carious dentin. j dent res 2011; 90: 506–11. 43. carrilho mr, tay fr, pashley dh, tjäderhane l, carvalho rm. mechanical stability of resin-dentin bond components. dent mater 2005; 21:232–41. 44. zhang sc, kern m. the role of dentinal hostderived matrix metalloproteinases in reducing dentin bonding of resin adhesives. international j oral sci 2009; 1(4): 163–76. الخالصة اثیر ـــتم انجاز ھذه الدراسة المختبریة لتقییم ت. مع مادة السنالسنیة الصقة لا لالنظمةربط الفقدان متانة ھي واحدة من اھم المشاكل في عمل الحشوات السنیة: نبذة والعشرون ربع العند فترة ا التخریش الشاملعلى قوة ربط العاج باستخدام نظام (chlorhexidine gloconate %2)% 2وكـــونیت كلـــ لورھیكسیدینــــمادة الك . و ثالثة اشھر من الخزن المائي ساعة بعد ان تم تقسیمھا % 36الفوسفورك سطح عاجي مستوي تم تحضیره الربعین عینة بشریة سلیمة للضواحك العلویة التي تم تخریشھا بحامض : المواد والطرائق مادة الكلورھیكسیدین تسلط لمدة ستون ثانیة , عشوائیا الى اربع مجامیع كل مجموعة مكونة من عشرة اسنان وحسب وقت التخزین وتسلیط مادة الكلورھیكسیدین بینما یتم تسلیط الماء المقطر غیر االیوني , وثالثة اشھر وحسب التوالي, التي تم فحصھا بعد اربع وعشرین ساعة, قبل عملیة تسلیط الالصق للمجامیع االولى والثالثة , التي تم فحصھا بعد اربع وعشرین ساعة وثالثــــة اشھر وحســـــب التوالـــــــــــي, لمدة ستون ثانیة قبل عملیة تسلیط الالصق بالنسبة للمجامیع الثانیة والرابعة .تم تســــلیطھ وتصـــلیبھ ضوئیـــــا (dentsply)مــــــــن شركـــة (prime and bond nt)بعد ذلك الصــــــــــق .ملم 2تم تعبئتھ من خالل قالب تم اعداده مسبقا لیعطي عینة رانتج الكومبوزت بصورة موحدة وبسمك (dentsply)رانتج الكومبوزت من شركة تفحظ لقوة الربط اللصقي , لحین وقت الفحص لكل مجموعة, بعد ذلك جمیع العینات تم تخزینھا في الماء الغیر ایوني بدرجة حرارة الغرفة ثم جمیع العینات تخضع ).ساعة و ثالثة اشھر 24(في نھایة فترة الخزن ایضا , النتائج اظھرت وجود فروقات ذات دالالت احصائیة عالیة بین المجامیع(one-way anova test) د ـــــاین باتجاه واحــــــبار تحلیل التبــــــاخت: النتائج مقارنة مع المجموعة , )اشھر 3الرابعة التي فحصت بعد (اظھر نقص في قوة الربط القصي بالنسبة للمجموعة الخالیة من الكلورھیكسیدین (t-test)فحص ال االولى التي فحصت بعد اربع (بمقارنة مجموعة الكلورھیكسیدین , (p<0.01)) الثانیة التي فحصت بعد اربع وعشرین ساعة( الثانیة الخالیة من الكلورھیكسیدین ایضا اظھر اختبار . (p<0.05)اظھرت النتائج عدم وجود فروقات ذات داللة احصائیة عالیة بقوة الربط ) التي فحصت بعد ثالثة اشھر(والثالثة ) وعشرین ساعة (student t-test) ساعة العشرون وعة االربع ومعدم وجود فروقات ذات داللة احصائیة في قوة الربط القصي بین المجموعتین االولى والثانیفي مج( p > .(p<0.01) والرابعة لكن بعد ثالثة اشھر من الخزن المائي لوحظ وجود فروقات ذات داللة احصائیة عالیة في قوة الربط القصي بین الجموعتین الثالثة ,(0.05 وقبل استخدام الرانتج العاجي ال یؤثر على قوة الربط التخریش الحامضي بعد % 2من الناتج اعالة نستنتج بانھ استخدام مادة الكلورھیكسیدین كلوكونیت : االستنتاج قوة الربط البیني للرانتج مع العاج بعد ثالثة اشھر بنحالل االعملیة تقلیل بینما یمكن ان یكون فعاال في , الفوریة خالل فترة االربع والعشرونساعة من الخزن المائي .من الخزن المائي .الصق التخریش الشامل, قوة الربط القصي, كلورھیكسیدین% 2: كلمات الداللة dropbox 6 ahlam f 32-35.pdf simplify your life luma f.doc j bagh college dentistry vol. 25(3), september 2013 marginal leakage restorative dentistry 35 marginal leakage of amalgam and modern composite materials related to restorative techniques in class ii cavity (comparative study) mohammad k. sabah, b.d.s. (1) luma m. baban, b.d.s., m.sc. (2) abstract background: restoration of the gingival margin of class ii cavities with composite resin continues to be problematic, especially where no enamel exists for bonding to the gingival margin. the aim of study is to evaluate the marginal leakage at enamel and cementum margin of class ii mod cavities using amalgam restoration and modern composite restorations filtek™ p90, filtek™ z250 xt (nano hybrid universal restorative) and sdr bulk fill with different restoratives techniques. materials and method: eighty sound maxillary first premolar teeth were collected and divided into two main groups, enamel group and cementum group (40 teeth) for each group. the enamel group was prepared with standardized class ii mod cavity with gingival margin (1 mm above c.e.j) on both box sides. while the cementum group with the gingival margin (1 mm below c.e.j) on both sides. the enamel and cementum groups were then subdivided into eight subgroups for each (five teeth) with 10 boxes for each group. subgroups within the main group named according to materials and techniques that were used with it as following: amalgam subgroup (permite, sdi), sdr subgroup (dentsply) with bulk technique, filtek™ p90 subgroup (3m espe) with three incremental techniques (oblique, horizontal and centripetal technique), and filtek™ z250xt subgroup (3m espe) with three incremental techniques (oblique, horizontal and centripetal technique).after specimens were stored in distilled water at 37°c for 7 days. all specimens were subjected to thermocycling at (5° to 55 °c). microleakage was evaluated by stereomicroscope (20 x). data were analyzed statistically by kruskal-wallis test and mann-whitney u-test. result: all experimental groups showed leakage at cementum more than enamel groups. sdr bulk fill subgroup showed the highest marginal leakage among all experimental groups followed by filtek™ z250 xt subgroup with horizontal technique at both enamel and cementum groups. silorane and filtek™ z250 xt subgroups with oblique technique showed the least marginal leakage followed by centripetal technique at both enamel and cementum groups. amalgam restoration subgroup shows lesser leakage than sdr bulk fills subgroup significantly at both enamel and cementum groups. while it show higher leakage than silorane subgroup with oblique technique significantly at enamel margin only. conclusion: the limiting factors for marginal leakage are technique and material dependent. key words: marginal leakage, composite resin, restorative techniques. (j bagh coll dentistry 2013; 25(3):35-42). introduction resin based restorative materials are used worldwide due to their good aesthetic characteristics. furthermore, their coupling with adhesive systems allows for the advantages of adhesive restorations such as minimally invasive treatment. from the early 1970s, resin their manufacturers concerning mechanical and aesthetic behavior have dramatically improved based restorative materials. this has been mainly achieved by continuous attempts to change their particle morphology particularly, the latest developments in nanotechnology. contemporary composite materials are very different from those of the 1970s. not only fillers have changed with time, but also matrix components have also been modified (1). however, for class ii cavities, the factors primarily responsible for microleakage problems are related to the initial shrinkage stress of the composite resin, the difference between the (1)master student, department of conservative dentistry, college of dentistry, university of baghdad. (2)professor, department of conservative dentistry, college of dentistry, university of baghdad. coefficient of thermal expansion of materials with hard dental tissue, the inaccessibility of the cervical area and, in particular, problems of bonding to the cervical substrate (2). the incremental technique based on polymerizing with resin-based composite layers less than (2 mm) thick can help achieve good marginal quality, prevent distortion of the cavity wall (thus securing adhesion to dentin) and ensure complete polymerization of the resin-based composite (3). materials and methods eighty sound maxillary first premolar teeth, non-carious, and non-restored were collected. all of them were checked for cracks, decay, fracture, abrasion or structural deformities using magnifying lens and by transilluminating fiber optic from a light cure device (4,5).all the teeth were cleaned carefully for any calculus deposits with air scaler and teeth were polished with pumice (6). a restoration template (manikin) was used to simulate the clinical situation during restoration placement. maxillary second premolar and j bagh college dentistry vol. 25(3), september 2013 marginal leakage restorative dentistry 36 maxillary canine (artificial teeth) were included in a manikin during the filling procedure, with a space between them to place the tested tooth and fixing by condensation silicon (7-9). eighty sound maxillary first premolar teeth were divided into two main groups, enamel group and cementum group (40 teeth) for each. enamel group will receive a standardized class ii mod cavity with gingival margin (1 mm above c.e.j) on both box sides (to have 80 boxes). while cementum group with gingival margin (1 mm below c.e.j) on both sides (to have 80 boxes).the enamel and cementum groups are then subdivided into eight subgroups (five teeth) with 10 boxes for each. subgroups within the main group were named according to materials and techniques that were used with it as following: amalgam subgroup (permite), sdr subgroup (dentsply), filtek™ p90 subgroup (3m espe) with three incremental techniques (oblique, horizontal and centripetal technique), and filtek™ z250xt subgroup (3m espe) with three incremental techniques (oblique, horizontal and centripetal technique). the dimensions of a standardized class ii mod cavity preparation boxes were (4 mm) in width bucco-lingually, (4 mm) in depth occlusally from the tip of palatal cusp to pulpal floor and (1.5 mm) depth axially (9,10). the cavity preparation was carried out on a dental surveyor after positioned the tooth in the template and fixed with condensation silicon. flat-ended fissure carbide bur (1 mm in diameter) used to carry out all preparations with a highspeed air water-cooled hand-piece, and a new bur was used for every four preparations to maintain cutting efficiency. all cavosurface line angles for all enamel and cementum groups are not beveled (9). each preparation’s dimensions was measured and verified with a periodontal probe. one operator performed all preparations, while another investigator checked them before restoration to ensure that they conformed to the dimensions (11). after complete of cavity preparation, a universal metal matrix band/retainer (ivory no.8) was placed around each prepared tooth and wedges placement then the boxes would be checked under magnification lens with probe to ensure that there is no any gap. amalgam subgroup: (admix, permite, sdi) mixing according to manufacture instruction and insert to cavity by amalgam carrier and condensed with amalgam condenser using a weight scale to adjust (400 gm) force till over filled of cavity then removed of access amalgam, carved and burnished to improve smoothness, adaptation and sealing of amalgam at the margins. bonding procedure: self-etch (adper™ easy bond, 3m espe) apply for entire cavity for 20 seconds and air dry for 5 seconds then light cure for 10 seconds according to manufacturer’s instructions. this adhesive used with sdr bulk fill and z250xt subgroups. silorane system adhesive (3m espe) was applied according to the manufacturer’s instruction, the primer placed to the entire cavity for 15 seconds then dispersed with a stream of air and light-cured the primer for 10 seconds then the bond rubbed and light-cured for 10 seconds according to the manufacturer’s instructions. bulk technique (b.t):the preparations were restored using resin composite bulk placement (single increment) and light cured (12).the sdr placed in a bulk increment (4 mm) according to the manufacturer’s instructions then curing for 20 seconds only from the occlusal surface. oblique technique (o.t): the first oblique increment not more than (2 mm) was contacted the gingival, axial, and buccal walls. after the first increment was cured, the second oblique increment was inserted to contact the occlusal, axial, and lingual walls (8). all increments were light cure 40 seconds for silorane p90 and 20 seconds for z250xt subgroups. horizontal technique (h.t): cavity filled with horizontal layering technique not more than (2 mm)(13). all increments were light cure 40 seconds for silorane p90 and 20 seconds for z250xt subgroups. centripetal technique (c.t):composite increment is applied on the cervical margin against the metal matrix transformation of class ii cavities into class i cavities, then the cavity completed by horizontally layering with not more than (2mm) for each increment (14). all increments were light cure 40 seconds for silorane p90 and 20 seconds for z250xt subgroups. after complete of the restorations, the restorations were finished and polished. all specimens were stored in distilled water at 37°c for 7 days then subjected to thermocycling according to the international organization for standardization (iso) tr11405 standard of 500 cycles, at 5° to 55 °c, with a 15 second dwell time (15,16). after that, apical foramina were sealed with resin modified glass ionomer (rmgi) cement. in order to prevent dye penetration into the dentinal tubules or the lateral canals, the teeth were coated with two layers of nail varnish except for an area approximately 1 mm around the gingival margin of the restorations (16).the teeth were then immersed in 2% methylene blue for 24 hours at 37°c. after removal from the dye solution, the teeth rinsed with running water (17). j bagh college dentistry vol. 25(3), september 2013 marginal leakage restorative dentistry 37 the root will be embedded in chemically cured acrylic resin with the long axis of tooth by dental surveyor up to (2 mm) apical to the cementoenamel junction (cej) to facilitate handling during sectioning procedures (11). the specimens were sectioned in mesio–distal direction at the center of the restorations with water coolant to obtain two similar dental fragments. the fragment that exhibited greater dye leakage was evaluated and the other was discarded (18). dye penetration evaluated at the gingival margin of the longitudinally sectioned teeth examined using a stereomicroscope (20 x). the extent of dye penetration was scored by two independent observers according to a five-points scale (11): 0 = no leakage. 1 = leakage extending to the outer half of the gingival seat. 2 = leakage extending to the inner half of the gingival seat. 3 = leakage extending up to 2/3 of the axial wall. 4 = leakage extending through the axial wall up to the pulpal floor. the data was analyzed using kruskal-wallis test to detect the significant differences among the groups. further analysis with mann-whitney utest was conducted for pair-wise comparisons among groups. results the microleakage percentage in filtek™ silorane p90 (o.t) subgroup has lowest value (60% score zero at enamel and 40% score zero at cementum), while in sdr subgroup has highest value (30% score 3 at enamel and 30% score 4 at cementum) as in bar chart (figure 1). the statistical analysis of data by kruskalwallis non-parametric one-way anova test revealed highly significant difference (p < 0.001) among the subgroups in enamel and cementum groups (table 1) and (table 2). the descriptive statistics will be presented as the mean, median, minimum value and maximum value of microleakage of enamel and cementum groups, are summarized in table 3and 4. to determine which mean is significantly different from which others, select box-andwhisker plot from the list of graphical options and select the mean notch option (figure 2, 3). the box represents the inter-quartile range. you have three points: the first middle point (the median), and the middle points of the two halves (what i call the "sub-medians"). these three points divide the entire data set into quarters, called "quartiles". the top point of each quartile has a name, being a "q" followed by the number of the quarter. therefore, the top point of the first quarter of the data points is "q1". note that q1 is also the middle number for the first half of the list, q2 is also the middle number for the whole list, and q3 is the middle number for the second half of the list. the whiskers represent the highest and lowest microleakage values. all experimental groups showed leakage at cementum more than enamel groups. sdr bulk fill subgroup showed the highest marginal leakage among all experimental groups followed by filtek™ z250 xt subgroup with horizontal technique at both enamel and cementum groups. silorane and filtek™ z250 xt subgroups with oblique technique showed the least marginal leakage followed by centripetal technique at both enamel and cementum groups. amalgam restoration subgroup shows lesser leakage than sdr bulk fills subgroup significantly at both enamel and cementum groups. while it show higher leakage than silorane subgroup with oblique technique significantly at enamel margin only. discussion in this study, there is no significant difference within the filtek™ silorane subgroup at both (enamel and cementum groups) with oblique, centripetal and horizontal placement technique, although oblique technique shows the least mean leakage value among them. the possible explanation may be that the oblique layering technique given minimal contact with the cavity walls during polymerization. therefore, there is a lower cavity configuration factor (c-factor) due to the large free surface permitting resin to flow during polymerization (19).these finding come in agreement with the study of mereuta et al. (20). mereuta et al. (20) evaluated the clinical performances of class ii composite restorations performed with different restorative techniques for 12 months as longitudinal study in vivo. there is no significant difference in marginal adaptation between the oblique layering technique and the centripetal build-up technique but oblique technique by mean was the best followed by centripetal and horizontal technique respectively. the result of this study shows that the oblique technique is the best technique to be used with filtek™z250 xt subgroup, although there is no significant difference between oblique and centripetal technique but the mean value for oblique technique is less at both enamel and cementum groups. on the other hand, the j bagh college dentistry vol. 25(3), september 2013 marginal leakage restorative dentistry 38 horizontal placement technique with filtek™z250 xt subgroup shows high mean leakage value with significant difference in comparison to the oblique and centripetal technique with both enamel and cementum groups. this may be attributed to that as we said previously to the high cavity configuration factor (c-factor), in which the c-factor with horizontal technique is 2, while the c-factor for oblique technique is 1.5 with minimum bonded surface permitting the resin to flow during polymerization. these results come in agreement with eakle and ito (21), neiva et al.(22), duarte and saad (23).they shows that the oblique layering technique has revealed less microleakage than bulk or other incremental techniques. szep et al. (24) postulated that in the proximal box first horizontal increment tended to pull away from the cervical margin during the polymerization shrinkage. giachetti et al. (19) concluded that large volume of increment could not compensate the polymerization shrinkage. these finding come in agreement with our study because the increment used to fill by horizontal technique is large by volume in comparison to the increment used for oblique technique. the result of this study shows that the centripetal technique comes after the oblique technique in reducing the microleakage with both materials p90 and z250xt subgroups with no significant difference between them. this may attributed to that in centripetal technique. a thin proximal layer placed towards the matrix band was cured before adjacent composite increments were applied into the cavity. this can reduce the v/a ratio, where v is the cavity volume and a is the area of the cavity walls. this first layer had less contact with the lateral walls. alternatively; the first layer of the centripetal technique had no contact to the pulpoaxial walls and thus had less tendency to contract toward this wall and away from the cervical floor during polymerization (24). this explanation comes in agreement with study of mereuta et al. (20). mereuta et al. (20) postulated the centripetal and oblique techniques, which were better than horizontal technique. by excluding of the placement techniques used in this study, the result revealed that the filtek™ silorane subgroup as composite restoration show low value of marginal leakage at both enamel and cementum groups in comparison to filtek™z250 xt and sdr subgroups. the possible explanation may be: a. the difference in the matrix system, the methacrylates based composite are cured by radical intermediates while filtek™ silorane via cationic intermediates. the ring-opening polymerization mechanism of oxirane moieties in the silorane monomer was responsible for the reduced shrinkage (less than 1%). therefore, the polymerization shrinkage of silorane based composite did not start immediately after light exposure, but an expansion occurred instead (25). b. filtek™ silorane took the longest time to reach gel and vitrification points (low degree of conversion).so the filtek™ silorane based composite react with slow set (slower to polymerize) , that allow for flow of material and stress relaxation(25). c. low water sorption and solubility of filtek™ silorane, due to presence of hydrophobic siloxane and quartz filler is more stable to leach into water than those with metallo-silica glasses (26-28).this result comes in agreement with al-qahtani et al. (29). al-qahtani et al. (29) show that the filtek™ silorane have lowest mean value of water sorption and solubility after storage for one week in distilled water due to hydrophobicity of silorane followed by filtek™ z250 xt and sd respectively. sdr subgroup shows the highest mean value of microleakage at both enamel and cementum group among all other subgroups with significant difference in comparison to filtek™ silorane, filtek™z250 xt and amalgam subgroups. the possible explanation may be: 1. high water sorption and solubility of sdr, due to: a. chemistry of sdr, that contain ethoxylated bisphenol a dimethacrylate (ebpadma), modified urethane dimethacrylate (mudm), and triethylene glycol dimethacrylate (tegdma) resins, and the last two are more hydrophilic than ebpadma, so higher water sorption is expected from this material compared with other resin based composite materials (30,31). b. sdr contains barium glass, strontium glass, some studies have shown that barium and strontium glasses are more readily leached into water than silica particles, and that the resin-based composite with quartz filler is more stable than those with metallo-silica glasses (26,27). this result comes in agreement with al qahtani et al. (29) who showed that the sdr have high mean value of water sorption and solubility after storage for one week in j bagh college dentistry vol. 25(3), september 2013 marginal leakage restorative dentistry 39 distilled water in comparison to filtek™ silorane and filtek™ z250 xt. 2. even with low stress that is provided by sdr about (1.5 mpa), but shrinkage volume is still high about (3.5%) followed by filtek™ z250 xt about (1.7%) and least shrinkage volume of filtek™ silorane (less than 1%) according to manufactures. this agrees with a clinical report of christensen (32) who concluded that the volumetric shrinkage and stress of bulk fill resins are not less than other conventional restorative resins. boaro et al. (33) showed that there is a weak relationship between shrinkage rate and shrinkage stress. matthias et al. (34) shows that none of the sdr groups caused less gap-free margins compared to incrementally layered resin composites. in this study, the amalgam restoration subgroup show higher marginal leakage with significant difference in comparison to p 90(o.t) in enamel group only. this may be related to that what we mentioned previously about low shrinkage characteristic of silorane (less than 1%) and the better performance of oblique placement technique over the other techniques (centripetal and horizontal) (19,20). additionally, the coefficient of thermal expansion of amalgam that is about three times greater than that for dentine. this coupled with the grater diffusivity of amalgam, results in considerably more expansion and contraction in the restoration than in the surrounding tooth when thermocycling may cause micro leakage around the filling. in addition, there is no adhesion between amalgam and tooth substance (15). in this study, the amalgam restoration subgroup show better performance with lower leakage significantly in comparison to sdr bulk fill and z250 xt (h.t) with both enamel and cementum groups. the possible explanation may be due to that what we mentioned previously about the shortcoming of sdr bulk fill and bad performance of horizontal technique. in this study, all subgroups show low mean leakage value at enamel than cementum group. the possible explanation may be: a. the bond strength to enamel is usually higher than bond strength to dentin. however, enamel is a highly mineralized tissue composed of more than 90% (by volume) hydroxyapatite. while, dentin is less favorable bonding substrate due to its heterogenous structure (35). b. the orientation of dentin tubules can affect the formation of the hybrid layer. in areas with perpendicular tubule orientation, the hybrid layer was significantly thicker than areas with parallel tubule orientation (35). c. the presence of fluid inside the dentinal tubules that diluted the dentin conditioner may decrease its potential for demineralization of the intertubular and peritubular dentin, and eventually affect on hybrid layer thickness (36). this result in agree with bogra et al. (9). bogra et al.(9) show that the dentin surface on the gingival floor of class ii preparations may be a surface on which good hybrid layer formation is difficult. mann-whitney u-test show significant difference at (p < 0.05) of sdr subgroup only while there is no significant difference between other materials and techniques subgroups. the possible explanation may be related to that the actually time of 20 second as recommended from manufacture to cure (4 mm) thickness of sdr thought to be insufficient for optimum polymerization, mainly on the bottom surface specially for the bulk build up technique. the increasing of the distance from bottom up to the cusp tip makes a serious problem in curing causes the resin composite on the bottom surface and disperses the light of the light curing unit. as a result, when the light passes through the bulk of the composite, the light intensity is reduces and the energy of the light emitted from a light-curing unit decreases drastically when transmitted through resin composite, leading to a gradual decrease in degree of conversion of the resin composite material at increasing distance from the irradiated surface(37,38). christensen (32)who compared different types of bulk fill resins (sdr), he concluded that the most bulk fill reins have many challenges which still exist for most material that include the light cure does not reach the bottom of deep box form. hilton and ferracane (39)compare the depth of cure of various bulk-placement composites as assessed by hardness. they found the sdr did not reach accepted hardness when used as (4 mm) increment. according to this study, it can be concluded that: 1. the sdr bulk fill not recommended to be used in deep class ii cavity. 2. low-shrinkage materials such as silorane and z250 xt recommended to be used with oblique and centripetal incremental techniques rather than horizontal incremental technique. references 1. ardu s, vedrana b, ivone u, nacer b, albert jf, ivo k. new classification of resin-based aesthetic adhesive materials. coll antropol 2010; 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(article in press). table 1. kruskal-wallis test for enamel group test statistical value p -value kruskal-wallis 31.6876 0.000 table 2.kruskal-wallis test for cementum group test statistical value p -value kruskal-wallis 41.0285 0.000 table 3. descriptive statistics of microleakage for enamel group table 4. descriptive statistics of microleakage for cementum group group materials & techniques subgroups sample no mean median (q1) median (q2) median (q3) minimum value maximum value c em en tu m p 90 (o.t) 10 0.70 0 1 1 0 2 p 90 (h.t) 10 0.70 0 1 1 0 1 p 90 (c.t) 10 0.90 0 1 1.5 0 3 z250 xt (o.t) 10 1.00 0 1 1.5 0 2 z250 xt (c.t) 10 1.10 1 1 1.5 0 2 amalgam 10 1.20 1 1 1.5 1 2 z250 xt (h.t) 10 2.00 1 2 3 1 3 sdr 10 3.30 3 3 4 3 4 group materials & techniques subgroups sample no mean median (q1) median (q2) median (q3) minimum value maximum value e na m el p 90 (o.t) 10 0.40 0 0 1 0 1 z250 xt (o.t) 10 0.50 0 0 1 0 2 p 90 (h.t) 10 0.60 0 1 1 0 1 p 90 (c.t) 10 0.60 0 1 1 0 1 z250 xt (c.t) 10 0.90 0 1 2 0 2 amalgam 10 1.00 1 1 1 1 1 z250 xt (h.t) 10 1.80 1 1.5 3 0 3 sdr 10 2.10 1.5 2 3 1 3 restorative dentistry 42 figure 1. microleakage percentage of enamel and cementum dropbox 9 nidhal f 48-51.pdf simplify your life 404 not found j bagh college dentistry vol. 29(3), september 2017 the effect of artificial pedodontics, orthodontics and preventive dentistry 106 the effect of artificial saliva on the surface roughness of different esthetic archwires (an in vitro study) noors. muayad, b.d.s. (1) nidhal h. ghaib, b.d.s., m.sc. (2) abstract background:the demand for esthetic orthodontic appliances is increasing so that the esthetic orthodontic archwires were introduced. this in vitro study was designed to evaluate the surface roughness of fiber-reinforced polymer composite (frpc) archwires compared to coated nickel-titanium (niti) archwires immersed in artificial saliva. materials and methods:three types of esthetic orthodontic archwires were used: frpc (dentaurum), teflon coated niti (dentaurum) and epoxy coated niti (orthotechnology). they were round (0.018 inch) in cross section and cut into pieces of 15 mm in length.forty pieces from each type were divided into four groups; one group was left dry condition and the other three groups were immersed in artificial saliva (ph=6.75 ± 0.015) at 37ºc for 1, 14 and 28 days intervals. the afm was used to evaluatesurface analysis of all samples.anova, kruskal-wallis, lsd and mann-whitney u tests were used to identify and localize the source of differences among the groups. results:at each immersion period, frpc wires exhibited the highest ra among the study groups, except at 28 days immersion period where the teflon coatings were the roughest. on the other hand, the least rough surfaces were the epoxy coatings when compared to analogous esthetic archwires, except at 1 day immersion period where the teflon coatings had the least roughness. however, statistically non-significant differences were found between teflon and epoxy at the dry condition and the 1 day immersion. conclusions:the epoxy coated archwires were the best and the most appropriate esthetic orthodontic alignment archwires in term of the least surface roughness initially and over the course of study period. keywords:esthetic archwires, fiber-reinforced polymer composite wires, surface roughness, afm. (j bagh coll dentistry 2017; 29(3):106-112) introduction with the advent of increasing number of adults seeking orthodontic treatment, the development of orthodontic appliances with ample emphasis on esthetics coupled with optimal performance has become an essential goal or rather necessity of the day(1). it has been partially solved by the introduction of esthetic brackets made of ceramic or composite (2). however, most archwires are still made of efficientunesthetic metal alloys such as stainless steel and nickel-titanium. an esthetic archwire is highly desirable to complement esthetic brackets in clinical orthodontics (3,4). coating metallic archwires with plastic resin materials were the main solution to provide esthetic characteristics to wires with metallic or silver coloredappearance (5). patients prefer that wires are not apparent or opaque, therefore alternatives could be archwires with transparent or translucent features (6). moreover, esthetic coatings of alloy archwires are not clinically durable and tends to tear over a period of time (5,7). through composite technology, an esthetic wire has been developed from continuous fibers and polymer matrix (tube shrinkage technique), giving rise to the fiberreinforced polymer (1) master student, department of orthodontics, college of (1)master student, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. entistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, composite (frpc) archwire which showed promise in its application as an esthetic aligning archwire (1,8). the translucent nature of the polymer matrix confers itsesthetic property, whilstthe fiber content gives the material flexibility, overcoming the inherent problem of composite brittleness(9). among the material’s characteristics that alter the behavior of the archwires, the surface roughness plays an important role. it is an essential factor in determining the esthetics and color stability of archwires, hygiene, biocompatibility, effectiveness of archwire-guided tooth movement, surface contact and friction, and thereby, the quality of orthodontic treatment(10-13). intra-orally placed materials (i.e. wires, brackets) exhibit a pattern of continuous reaction with the environmental factors present in the oral cavity(14). orthodontic materials are in contact with a variety of substances that impose potent effects on their reactive status and surface integrity such as saliva(15). looking at the surface roughness before and after immersion in artificial saliva using atomic force microscopy (afm) may give more insights to these frpc archwires and their application in orthodontics compared to their counterparts. materialsand methods preparation of artificial saliva j bagh college dentistry vol. 29(3), september 2017 the effect of artificial pedodontics, orthodontics and preventive dentistry 107 the components of artificial saliva (400 mg/lnacl, 400 mg/l kcl, 960 mg/l cacl2.2h2o, 690 mg/l nah2po4.2h2o, 5 mg/l na2s.9h2o, 1000 mg/l urea) (16-19)were measured via an electronic balance, and stirred with a glass rod until all the components dissolved in water (500 ml deionized water and 500ml distilled water). the ph of artificial saliva was adjusted to 6.75±0.015 using aph meter (jenway, model 3320, cyprus)corresponding tothe human salivary ph (20,21). preparation and grouping of the samples the sampleswere consisted of three types of roundcross-section (0.018 inch) maxillary esthetic archwires: frpc archwires (translucent ideal arches pearl, dentaurum, germany), teflon labially coated niti archwires (rematitan® “lite” white ideal arches, dentaurum, germany) andepoxy fully coated niti archwires (tooth tone® arches, orthotechnology, brazil). the straight portions were cut into pieces of 15 mm in length(21). total of 120 pieces, 40 pieces from each kind of archwires, weredivided in such away that 10 pieces from each type remained in a dry condition as a control group, while the other 30 pieces were immersed in artificial saliva for different immersion periods (1 day, 14 days and 28 days),ten pieces each. afterward,sampleswas placed in glass containers seperately and held from one of its ends using dental floss in such a waythat avoid touching the wall.artificial saliva was added so that the sample was immersed completely except for the epoxy ball. thereafter, the glass container was capped perfectly by its lid and a piece of parafilm (figure1). figure 1: immersion of the sample in the artificial saliva. after that, the samples were kept at 370c in an incubator (fisher scientific, usa)for 1 day, 14 days and 28 days intervals.the artificial saliva was replacedregularly every 7 days with a fresh solution to avoid its saturation with the degradation products(20,21).after the intervals were elapsed the samples were washed with distilled water, left to dry on filter papers and then kept in petri dishes. preparation of testing specimens preparation of slides and fixing the samples in order to use afm for analysis,it needs to use small slides instead of regular ones.the slides were cut into small sections (1x1 cm)using a diamond cutting pen.each wire segment was then affixed on a new slide (figure 2). for the labially coated samples, they were fixed with their labial surface facing upward(22). figure 2: wire sample fixed on a small slide. cleaning the samples after each incubation the samples were immersed in distilled water with one drop of 2% sodium dodecyl sulfate solution, and ultrasonically cleaned at 20 watt for 3 minutes to remove the contaminated layer formed during handling. the samples were then rinsed with distilled water, allowed to dry in air and kept in closed petri dishes to be ready for the assessment. testing the samples the afm was used to assessthe surface topography of the samples(21-27).for each specimen, three areas on the archwire have been scanned with a scanning area of 25 * 25 µm: one in the center of the wire and the others on 2 mm away on both sides. their mean value was used. two numerical values in nm were determined in each scan (ra and ry) to elucidate its surface roughness(3,4,25).ra (average roughness)is the arithmetical mean of the absolute valuesof the scanned surface profile, while ry (maximum peak-to-valley roughness height) is the maximum height of a profile peak(23). tapping mode was used under ambient conditions(8,24).the specimen was fixed to a piezo scanner with three translatory degrees of freedom. subsequently, the three dimensional afm view was shown on the monitor of the attached computer representing the surface of the specimen. usingproprietary software supplied with the afm, the images were processed. statistical analysis data were analyzed using a computer software j bagh college dentistry vol. 29(3), september 2017 the effect of artificial pedodontics, orthodontics and preventive dentistry 108 (spss -statistical package of social science-, version 19, chicago, usa). the following statisticswere used: a. descriptive statistics:including: the mean, median, standard deviation (s.d.),minimum (min.) and maximum (max.) values andstatistical tables. b.inferential statistics data were tested for its normality using the shapiro-wilks test.in addition,one-way analysis of variance (anova), kruskal-wallis test, least significant difference (lsd) and mann-whitney u test were carried out to see if there were any significant differences among the groups and to examine the source of these differences. the probability (p) value of more than 0.05 was regarded as statistically non-significant and less than 0.05 was considered as significant. results average roughness (ra) at first, using shapiro-wilks test, it was found that ra values were normally distributed. table (1) showed that at each immersion period, frpc wires had the highest ra among esthetic archwires, except that, at 28 days immersion period, the teflon coated wires were the roughest. on the other hand, the lowest ra found in epoxy coated wires except that at 1 day immersion period, the teflon coated wires had the lowest. one-way (anova) demonstrated a highly significant difference in ra among the three types of wires at each immersion duration (p=0.000). the data revealed that there were nonsignificant differences in ra between teflon coated and epoxy coated wires at the dry condition and the 1day immersion, whilst a highly significant difference was found between each pair of wire's types at other durations(table 2). table 1: mean and s.d. values of the average roughness (ra) in nm of different esthetic archwire types. condition wire types descriptive statistics anova test (d.f.= 29) mean s.d. min. max. f-test p-value dry condition frpc 147.14 13.06 135.94 168.63 16.947 **0.000 teflon coated 111.45 15.82 92.38 129.45 epoxy coated 109.18 19.54 90.53 143.12 1 day immersion frpc 182.991 9.89 172.10 199.43 264.187 **0.000 teflon coated 104.79 9.91 90.55 115.23 epoxy coated 107.62 5.18 100.07 112.23 14 days immersion frpc 157.91 7.40 150.70 168.61 289.496 **0.000 teflon coated 121.46 6.53 112.35 128.95 epoxy coated 89.22 5.00 83.01 96.43 28 days immersion frpc 126.93 12.26 107.76 139.33 47.086 **0.000 teflon coated 172.24 27.68 140.81 219.13 epoxy coated 95.41 5.83 87.99 104.21 (**) means highly significant (p ≤ 0.01). table 2: differences in ra of different types of esthetic wires ateach immersion period. condition wire types mean difference p-value dry condition frpc teflon coated 35.69 **0.000 epoxy coated 37.95 **0.000 teflon coated epoxy coated 2.26 0.759 1 day immersion frpc teflon coated 78.13 **0.000 epoxy coated 75.30 **0.000 teflon coated epoxy coated -2.83 0.469 14 days immersion frpc teflon coated 36.45 **0.000 epoxy coated 68.69 **0.000 teflon coated epoxy coated 32.24 **0.000 28 days immersion frpc teflon coated -45.31 **0.000 epoxy coated 31.52 **0.000 teflon coated epoxy coated 76.84 **0.000 (**) means highly significant (p ≤ 0.01). j bagh college dentistry vol. 29(3), september 2017 the effect of artificial pedodontics, orthodontics and preventive dentistry 109 maximum peak-to-valley roughness height (ry) shapiro-wilks test revealed that ry values were not normally distributed. table (3)showed that at each immersion period, frpc wires had the highest ry among esthetic archwires, except that, at 28 days immersion periods, the teflon coated wires had the highest value. on the other hand, the lowest ry found in epoxy coated wires except that for the control group, the teflon coated wires had the lowest value. kruskal-wallis test demonstrated a non-significant difference in ry among the three types of wires at 14 days immersion period and a significant difference between them at the 28 days immersion, whereas highly significant differences were found at the other two periods. mann-whitney u test revealed that there were non-significant differences in ry between tefloncoated and epoxy coated wires at the dry condition, frpc and teflon coated wires at 1 day immersion period and frpc and epoxy coated wires at 28 days immersion period. in contrast, ry differed significantly between frpc and epoxy coated wires at the dry condition, frpc and teflon coated wires at 28 days immersion period and teflon coated and epoxy coated wires at 28 days immersion period, while highly significant differences were found between the others (table 4). table 3: medianvalues of the maximum roughness height (ry)in nm of different esthetic archwire type. condition wire types descriptive statistics kruskal-wallis test (d.f.= 2) median min. max. x2 p-value dry condition frpc 731.080 635.790 819.780 13.154 **0.001 teflon coated 329.420 202.110 525.090 epoxy coated 414.350 214.710 910.950 1 day immersion frpc 260.350 255.700 269.620 19.079 **0.000 teflon coated 256.850 192.270 368.200 epoxy coated 170.725 143.470 193.520 14 days immersion frpc 247.260 203.340 256.100 5.040 0.080 teflon coated 245.920 204.840 260.100 epoxy coated 218.880 99.489 245.930 28 days immersion frpc 215.955 153.260 241.470 6.823 *0.033 teflon coated 241.040 206.530 435.800 epoxy coated 174.410 135.340 278.160 (*) means significant (0.05 ≥ p > 0.01). (**) means highly significant (p ≤ 0.01). table 4: differences in ry of different types of esthetic wires at eachimmersion period. condition wire types mann-whitney u test p-value dry condition frpc teflon coated 0 **0.000 epoxy coated 23 *0.041 teflon coated epoxy coated 36 0.290 1 day immersion frpc teflon coated 44 0.650 epoxy coated 0 **0.000 teflon coated epoxy coated 1 **0.000 28 days immersion frpc teflon coated 24 *0.049 epoxy coated 42 0.545 teflon coated epoxy coated 18 *0.016 (*) means significant (0.05 ≥ p > 0.01). (**) means highly significant (p ≤ 0.01). discussion at the dry condition, frpc wires were the roughest (had the highest ra) which was presumably due to the concurrent high (ry) values in relation to other two types this might be due to the surface characteristics of the composite material and/or the manufacturing process. the pre-existed surface defects are believed to be the j bagh college dentistry vol. 29(3), september 2017 the effect of artificial pedodontics, orthodontics and preventive dentistry 110 preferred degradation sites and accelerate it due to the higher residual stressesbesides harboring stagnant solution. thesemight contribute todislodgement of fillers from composite materials in artificial saliva which is in agreement with ferracane and condon(28)and/or leaving partly exposed filler particleswhich is in agreement withlarsen and munksgaard(29) that might explain the higher roughness of frpc wires than the other wires in artificial saliva thereafter.this outcome is also congruent with the findings noted by al-najafy(30),al-jumailiand tawfek(31)andchng et al.(8). on the contrary,inami et al.(13)found that the surfaces of the as-received frpc and metallic wires (except β-ti) appeared almost smooth with slightly higher ra in the frpc ones. the cause of this conflicting finding might be due to the differentmanufacturers of frpc archwires used in both studies such as biomers. teflon coated niti archwires had the highest roughness at 28 days that were probably explained by changes in the elemental composition of their surfaces and the occurrence of additional elements due to interactions with saliva that altered the morphology, which is in agreement with zegan et al.(32). this result is also in concordance with the one month clinically retrieval and afm study done by rongo et al.(26).however, in these two in vivo studies, two factors might contribute to this effect; intra-oral exposure of teflon coated archwires and the archwire-bracket friction and thereby direct comparisons with the present results are difficult due to the differences in the study designs.conversely, the current result contradictsmohsin(21) study which was a similar afm study reported non-significant differences in roughness between teflon and epoxy niti coated wires at 28 days immersion period in artificial saliva. thecause of this disagreement might be the different manufacturers of the teflon coated wires used and the slightly different protocol used as measuring roughness without ultrasonic cleaning and immersion of 10 samples in the same container that might alter the roughness values. on the other hand, the least rough surfaces (ra) were the epoxy coatings compared to the analogous archwires, except that at 1 day immersion periods where the teflon coatings had the lowest ra. however, statistically nonsignificant differences were found between teflon and epoxy at the dry condition and the 1 day immersion. this might be attributed to the concurrent low (ry) values of the two coatings at the dry condition in relation to the frpc wires, being non-significantly different between teflon and epoxy coatings which coincides with that reported by rongo et al.(26).this might be ascribed to the method of applying the coating, which could require some surface treatment and/or heat treatment, and/or due to the properties and composition of the coating material, and these specific information are not readily available and are companies secretes. furthermore, these little pre-existed surface defects inflicted during manufacturing process are believed to prefer less and slow the degradation that might explain the lower roughness of epoxy coated wires than the other wires in artificial saliva thereafter. in addition, the epoxy resin was primarily recognized for its excellent adhesion and a broad range of physical properties, such as chemical resistance and dimensional stability. meanwhile, due to the strength of the carbon-fluorine bonds, ptfe (teflon) is nonreactive and hydrophobic. all that is in agreement with kravitz(33). these data are also consistent with the results of other previous afm study done byd'antò et al. (23)and mohsin(21).in addition, the results from the current study agreed with that reported by krishnan et al.(25)who found that the as-received epoxy coated niti wires demonstrated the significantly lowest roughness values. however, they found higher roughness values of teflon coated niti wires in relation to other study groups (surface modified and conventional niti wires). similarly, krishnan et al. (34) found that teflon had more breakdown potential in ringer´s solution than the epoxy type that complies with the current result. however, the present result disagreed with their findings, which showed a significant higher roughness of epoxy than teflon coatings in asreceived state. these inconsistencies might arise from the different manufacturing processes of the niti-based archwires and/or from the different protocols used.on the other hand, the present result disagreed withrongo et al.(26) who found that the epoxy coated niti wires had a significantly lower roughness than teflon in the as-received state. generally, the disparities in roughness among the three types of wires might be attributed to the type of surface material, manufacturer, and manufacturing technique. moreover, probable factors influencing the surface integrity in artificial saliva might be associated with the original surface roughness, deposition method (synthesis and fabrication process) used, material stability, and surface material-substrate adhesion strength that is in agreement with bourauel et al.(11), daemset al.(12),ryu et al.(27)andzegan et al.(32). it can be concluded from this in vitro study that the surface roughness of esthetic archwires j bagh college dentistry vol. 29(3), september 2017 the effect of artificial pedodontics, orthodontics and preventive dentistry 111 immersed in artificial saliva has a material specific pattern. further refinement in the manufacture of frpc archwires would be necessary to fully realize their potential as esthetic archwires. care should be taken of their extremely high initial roughness. in addition, improvements to coating techniques of teflon coatings or using alternative wires must be explored. epoxy coated archwires are the best esthetic archwires in term of the least surface roughness initially and over the course of orthodontic treatment for patients seeking esthetics during fixed appliance therapy. references 1. huang zm, gopal 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shibata y, nishiyama n, kasai k. surface topography, hardness, and frictional properties of gfrp for esthetic orthodontic wires. j biomed mater res b applbiomater 2016; 104(1):88-95. 14. eliades t, athanasiou ae. in vivo aging of orthodontic alloys: implications for corrosion potential, nickel release, and biocompatibility. angle orthod 2002;72(3):222-37. 15. eliades t, eliades g, watts dc. intraoral aging of the inner headgear component: a potential biocompatibility concern?.am j orthoddentofacialorthop 2001;119(3):300-6. 16. heravi f, mokhber n, shayan e. galvanic corrosion among different combination of orthodontic archwires and stainless steel brackets. j dent mater tech2014;3(3):118-22. 17. liu jk, liu ih, liu c, chang cj, kung kc, liu yt, lee tm, jou jl. effect of titanium nitride/titanium coatings on the stress corrosion of nickel-titanium orthodontic archwires in artificial salvia. appl surf sci2014;317:974-81. 18. poosti m, ahrari f, moosavi h, najjaran h. the effect of 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surface roughness of orthodontic arch wire materials (an in vitro study). master thesis, college of dentistry, university of mosul, mosul, iraq, 2006. 31. al-jumaili ka, tawfekzs. evaluation of the effect of immersion periods in the artificial saliva on the surfaceroughness of three types of orthodontic arch wires. al–rafidain dent j 2008;8(1):72-8. 32. zegan g, sodor a, munteanu c. surface characteristics of retrieved coated and nickel-titanium orthodontic archwires. rom j morpholembryol2012;53(4):935-9. 33. kravitz nd.aesthetic archwire. 2013. a report from internethttp://www.orthodonticproductsonline.com on 16/10/2015. 34. krishnan m, seema s, kumar av, varthini np, sukumaran k, pawar vr, arora v. corrosion resistance of surface modified nickel titanium arch wires. angle orthod2014;84(2):358-67. ةالخالص يبببدث اس تيبببيم نابببلتج اليبببي ن الد مسلسبببلا ةبببمم ببب ال ايبببل إن الطلبببل لبببة تقوببباأل نابببلتج اليبببي ن الد مسلسبببل لبببم نااتببب بببدم لببب ل نبببج إ:ةالمقدم لببببم الم مليببببل niti))يأيببببيم اليسيببببو نسدببب سل الم ل ببببل ا ببببل (frpc)الماببببلاأل ي للسببب البللسم تببببلل يبببيم الم بببببيببببط التالد تبسبببل لداسببببسج ببببل ل اللع ب اإلةي ما ، (dentaurum)المابببلاأل ي للسببب البللسم تبببلل يبببيم الم ببببيبببيم نابببلتج اليبببي ن الد مسلسبببل التخ ا ثيثبببل ت بببلا ببب دنبببج إيبببالم اطريقة ق ةرال م : بببببب قمسعوبببببب ببببببد ت أل الماطبببببب .(orthotechnologyنسدبببببب سل الم ل ببببببل ي إلتبل ببببببم )( اليسيببببببو dentaurumيبببببب لد للن )اليسيببببببو نسدبببببب سل الم ل ببببببل لبببجا ت يعبببلن تطعبببل ببب بببو بببل ت بببم إلبببة ت يعبببل ببب س ا ن ببب الم مل بببل ال لبببة لبببم البس بببل ال لبببل 1.لبببة تطببب يطبببل إإ بببو( تطعببب 0.0ا0) 1., .لمببب أل ة قبببل يبببلساتل 37(نثببب ة قبببل ببب ا أل 0.015 ± 6.75=لضبببل ع بببو الثم لم س الثيثبببل ال ببب ل لبببم اللعببب ب اإلةبببطي م )غم بببد anova ( ،)(kruskal-wallis( ،(lsdا )ِتيبببببدخ إ دببببببب ا العسيبببببب ا قمسببببب تيببببببط تبببببل ا تيبببببدخ وبببببب الابببببلل ال تببببببل ل ايبببببل 80 mann-whitney u)لدث ت نمسسا ص اإل ديل يس الم س ا ) لدبببب أل يبببب بببب بببب ا ،يببببس الم بببب س الم يببببلa(r(ت لببببة تببببسج الماببببلاأل ي للسبببب البللسم تببببلاليببببيم الم بببببل تظو ، ببببو لدبببب أل إ مبببب يبببب النت : ببب تل ببب تغل بببل اإلتبل بببم يببب ببب اليبببط التبببو بببل ل ،تبببل سببب ببب تغل بببل الد لبببلن بببم ال ثببب بببل لا ببب قوبببل ت ببب ل 80اإل مببب غس ت بببج قببب ل تببب غسببب عيلتبببل خ بببل لاتبببسج التغل بببل الد لل أتبببو إ دليببب لدببب أل اإل مببب لسبببل ا ببب سث يببب ببب ببب ا ،اليبببيم الد مسلسبببل الميببب ظ أل يس الد للن اإلتبل م ي الث لل ال لل أل اإل م لسل ا اإ ص ئس بببي ن بببدم ل وببب التبببو بببل ل الب اتبببل ال ثببب ي بببل اللضبببو اليبببيم الم ل بببل ي إلتبل بببم بببم تيبببيم نابببلتج اليبببي ن الد مسلسبببل إن س تنت :اإل اال ايللد أل و الالل ال تلا المالاأل ي للس ، ل ل ال ط ، البللسم تلم بل الييم الالييم الد مسلسل، :الكلم ترالة يسية http://www.ncbi.nlm.nih.gov/pubmed?term=krishnan%20m%5bauthor%5d&cauthor=true&cauthor_uid=24004028 http://www.ncbi.nlm.nih.gov/pubmed?term=seema%20s%5bauthor%5d&cauthor=true&cauthor_uid=24004028 http://www.ncbi.nlm.nih.gov/pubmed?term=kumar%20av%5bauthor%5d&cauthor=true&cauthor_uid=24004028 http://www.ncbi.nlm.nih.gov/pubmed?term=varthini%20np%5bauthor%5d&cauthor=true&cauthor_uid=24004028 http://www.ncbi.nlm.nih.gov/pubmed?term=sukumaran%20k%5bauthor%5d&cauthor=true&cauthor_uid=24004028 http://www.ncbi.nlm.nih.gov/pubmed?term=pawar%20vr%5bauthor%5d&cauthor=true&cauthor_uid=24004028 http://www.ncbi.nlm.nih.gov/pubmed?term=arora%20v%5bauthor%5d&cauthor=true&cauthor_uid=24004028 http://www.ncbi.nlm.nih.gov/pubmed/?term=corrosion+resistance+of+surface+modified+nickel+titanium+arch+wires dropbox 01 anaam 1-4 .pdf simplify your life wsamaa.doc j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 96 the effect of incorporating carbon nanotubes on impact, transverse strength, hardness, and roughness to high impact denture base material wsamaa s. mahmood, b.d.s., m.sc. (1) abstract background: one of the most common complications of dentures is its ability to fracture, so the aim of this study was to reinforce the high impact denture base with carbon nanotubes in different concentrations to improve the mechanical and physical properties of the denture base. materials and methods: three concentrations of carbon nanotubes was used 0.5%, 1%, 1.5% in a pilot study to see the best values regarding transverse strength, impact, hardness and roughness test, 1 wt% was the best concentration, so new samples for control group and 1wt% carbon nanotubes and the previous tests were of course repeated. results: there was a significant increase in impact strength and transverse strength when we add carbon nanotubes in 1wt%, compared to control group where as hardness decrease when adding carbon nanotubes. conclusion: the addition of carbon nanotubes improves the physical and mechanical properties. key words: carbon nanotubes, high impact denture base. (j bagh coll dentistry 2015; 27(1):96-99). introduction poly methylmethacrylate is one of the most widely used material in prosthetic dentistry, because of its good esthetic, ease of manipulation, low density, low cost and ability to repair, but one of the most common complications of denture base prosthesis is cracking of denture due to its rigidity either from long-term fatigue failure caused by repeated masticatory force or from extra-oral high impact force resulting from accidental dropping of the prosthesis. studies have shown that 68% of dentures will break within few years of fabrication (1-4). so serious efforts to improve the properties of denture base, the goal is to create a material with better mechanical properties; some of these efforts were by incorporating different additives to the polymer like glass fiber, metal wires, long carbon fibers, metal powder fillers, and cnt (carbon nanotubes).(5) a wide interest has been generated regarding the use of carbon nanotubes in dentistry, still few reports on the use of cnt as dental material. cnt are macromolecular form of carbon and considered as a class of nanomaterials, with high potential of biological applications due to their mechanical , physical and chemical properties, cnt has large surface area, ultra-light weight, they are structures of single or multiple sheets of graphene rolled up to form single walled and multiwall cnt (6,7) as in figure (1). what makes cnt so stable is the strong bond between carbon atoms, in nanotubes the carbon atoms arrange themselves in hexagonal rings, however their only drawback is the high cost and color.(8) (1)lecturer. department of prosthodontics. college of dentistry, university of baghdad. nano technology will bring enormous changes into the field of dentistry, however it might pose a risk of misuse, time and human need will determine which of the applications are first realized.(9) figure 1: single wall and multi wall carbon nanotubes materials and methods a pilot study was first undertaken in this study to find out the best concentration of carbon nanotubes when incorporated to high impact denture base material (vertex). three concentration were selected 0.5wt%, 1.0wt% and 1.5wt% of single wall carbon nanotubes, three samples for each concentration and three samples for each test, were constructed in the dental lab of prosthetic department, collage of dentistry, baghdad university according to the manufacturing instructions as shown in figure (2). figure 2: samples of pilot study j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 97 dxb 2x width x(thickness)2 10 ml of monomer is added to 21mg of powder after mixing, and reaching the dough stage, applying it carefully into the mold which were previously fabricated in the lab following the conventional flasking technique for complete denture with the following dimensions 65× 10×2.5mm (ansi, ada specifications no.12) for transverse strength, hardness and roughness, 80×10×4 mm (iso 179) for the impact test.(10)then curing for 90 minutes in700c followed by 30 minutes in 1000 c, allow for bench cooling; after finishing all the samples, they were re-measured by the digital vernier, the above procedure is for making the control sample, same previous technique is repeated, but by adding carbon nanotubes to 10ml monomer with the aid of the probe sonication apparatus for proper dispersion of nanomaterial to the monomer then quick mixing with 21mg powder to prevent agglomeration. for accurate measurement of powder, carbon nanotubes, electronic balance was used. for the impact strength, we use impact testing machine, the following equation give us the result in kj/m2. impact strength= energy x103 d=thickness of specimens b=width of specimen for testing transverse strength we use the universal testing machines and the final result was obtained from the following equation: transverse strength= 3x load x span length the profilometer device was used to study the roughness of specimens. for hardness test shore d hardness is suitable device for measuring the acrylic. table 1: the mean values of the pilot study % impact strength kj/m2 transverse strength n/mm2 hardness no. roughness μm 0% 8.25 105 83.3 3.27 0.5% 9.18 134.8 68.3 2.66 1.0% 11.7 160.8 66 2.35 1.5% 10.34 90.7 67 3.93 based on results obtained from table (1), the 1.0wt% carbon nanotubes had the best values, therefore the decision was to choose this concentration; new samples were prepared, they were divided to two groups first group with no additives (control group), the other group is high impact denture base with 1wt% carbon nanotubes, ten sample for each test were made as previously mentioned. results the statistic analyses give the following results; first table (2) shows the mean, standard deviation, standard error, minimum and maximum of impact strength, transverse strength, roughness and hardness for the control group, whereas table (3) give us the same descriptive values of the same mechanical test but for specimens with1.0wt% cnt. for the impact strength the mean value was much higher when adding 1.0wt% cnt 11.18kj/m2, t-test showed significant difference. for the transverse strength, the values is also higher 157.3n/mm2 as seen in table (3) when adding 1.0wt% cnt, compared to the mean values of control samples 107.07 n/mm2, the ttest give us a highly significant difference as seen on table (4). roughness is lower in table (3) when compared to control group in table (2), also the mean value of hardness test showed higher values in table (2) equal to 83.3, compared to table (3) where the mean values equal 66.3. table 2: descriptive of control groups roughness μm. hardness no. transverse strength n/mm2 impact strength kj/ms 3.128 83.22 107.07 8.39 mean 0.323 3.338 11.702 0.735 sd 0.103 1.063 3.726 0.234 se 2.74 80 90.7 7.4 min 3.605 89.1 122 9.5 max j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 98 table 3: surface hardness, roughness, impact strength, transverse strength parameter analysis for 1.0w% cnt roughness hardness transverse strength impact strength 2.473 66.58 157.36 11.183 mean 0.574 3.513 7.093 2.168 sd 0.182 1.118 2.259 0.690 se 1.66 61 148.6 8.78 min 3.09 72.8 169.3 14.8 max table 4: t-test between control group and 1.0wt%cnt roughness hardness transverse strength impact strength 3.828 9.871 11.154 4.29 t-test 0.004 p<0.01 p<0.01 0.002 p-value hs hs hs s sig *p<0.05 significant, hs<0.01 discussion this study was designed to investigate the application of carbon nanotubes to high impact denture base resin on some mechanical properties, cnt was chosen because limited studies on their use plus it is known of its high material properties, which are very close to their theoretical limits, like electrical, strength, stiffness and toughness.(11) the pilot study shows that 1.0wt% cnt had the best values whereas higher wt% of cnt had lower values than control groups, may be due to the inhomogeneous dispersion of cnt causing more agglomerations, the other cause is associated with the interfacial interaction-wetting between polymer and cnt (12). so the decision was to take the 1.0wt% cnt. impact strength impact testing machine was used to measure the impact strength, results showed increase values in table (3) when adding 1.0wt% cnt , the highly significant increase in impact strength of the specimen could be due to the inclusion of cnt into the polymer (4), this comes in agreement with mars and pienkowski (13) that cnt effectively bridge the cracks, also cnt is strong and stable because, carbon in nanotubes are arranged in hexagonal ring, this lead to a reduction in segmental motion thus increasing the impact strength, results agrees with luciano et al(14), and sung et a l(15), that impact strength increase when acrylic resin is reinforced with eglass fiber, also with hari et al (16) when adding glass fiber to high impact denture base material. transverse strength the assessment of transverse strength is used in most studies as its loading effect mimics the clinical situation, when denture is in the oral environment receiving various forces. as seen in table (3) transverse strength is higher than table (2) with highly significant difference, results agree with zhou (17) by adding carbon nanotubes to poly methylmthacrelate denture base material cause improvement of transverse strength, also ayad et al (2) showed an increase in transverse strength of high impact resin when reinforced with zirconia, could be explained by the good dispersion of nano particles which enable them to inter between the chains of polymer and fill the space between them, this will restrict chain movement and will increase strength and rigidity, thus ameliorating the transverse strength (18), also comes in agreement with wang et al when adding cnt to denture base (12). authors also found that loading cnt in polymethyle methycrelate pmma improve transverse strength, it was suggested that well dispersed cnt is able to reinforce pmma matrix prior to crack initiation and arresting the early phase of crack propagation (19,20). roughness in the present study we use the profilometer device to estimate the effect of incorporating cnt on surface geometry of specimens, results showed decrease of surface roughness when adding 1.0wt% cnt because cnt are very small in size and well dispersed and since roughness test measure only surfaces, so few particles of cnt on the surface will have no effect, this result agrees with dahham (20) when modified zno filler were added to heat cure acrylic. hardness with the aid of shore d hardness tester, the values of hardness decreased in table (3), since j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 99 the improvement of properties of cnt and polymer are result of the type of cnt used, the weight added percentage, dispersion, alignment of cnt and polymer matrix (4) , so may be one of the above factor did contribute to the result obtained . abdulameer (22) also found a decrease in surface hardness when titanium powder is added to acrylic, results also agrees with ayad et al (2) found that adding zirconia to high impact acrylic resin did not improve the hardness. the study above showed an improvement of the mechanical properties of high impact denture base when adding cnt, although the material is black in color, so until this esthetic problem is resolved, it may be used in mid line area of complete denture for reinforcement, since it is not a visible place. references 1. meng t, latta m. physical properties of four acrylic denture base resin. j contemp dent pract 16 2005: 93100. 2. ayad nm, badawi mf, fatah aa. effect of reinforcement of high impact acrylic resin with zirconia on some physical and mechanical properties. rev clin pesq odontol 2008; 4(3):145-51. 3. abhay pn, karishma s. comparative evaluation of impact and flexural strength of four commercially available flexible denture base materials: an in vitro study. j indian prosthodont soc 2013; 13: 499-508. 4. qasim sb, al kheraif aa, ramakrishaniah r. an investigation into the impact and flexural strength of light cure denture resin reinforced with carbon nanotubes. world applied science j 2012; 18(6): 80812. 5. scotti k. mechanical properties evaluation of denture base pmma enhanced with single-walled carbon nanotubes. thesis, indiana university school of dentistry, 2010. 6. bai yu, iisong p, taesung b, kyounga k, fumio w, motohiro uo, minho l. carbon nanotubes coating on ti substrate modified with tio2 nanotubes. j wuhan univ technology-mater sci edu 2011. 7. kou w, aksaka t, wakari f, sjogren g. an in vitro evaluation of biological effects of cnt-coated dental zirconia" isrn dentistry, 2013. http://dx.doi.org/10.1155/2013/296727. 8. collins pg, avouris p. nanotubes for electronics. j scientific american 2000: 62-69. 9. archana b, abhishek b, abhinav m, sohani m, manjula s, aruind k. nanotechnology in dentistry: present and future. jioh 2014; 6(1):121-6. 10. iso 179-1:2000: plastic...determination of charpy impact properties—part 1: non-instrumented impact test. 11. applications and benefits of multi-walled carbon nanotubes" internet. http://www.cefic.org/documents/other/benefits%20of %carbons%20nanotubes.pdf. 12. wang r, tao j, yu b, dai l. characterization of multiwall carbon nanotubes-polymethyl methacrylate composite resins as denture base materials. jpd 2014; 3(4): 318-26. 13. mars b, pienkowski ad. multi wall carbon nanotubes enhance fatigue performance of physiologically maintained methyl methacrylate-styrene copolymer. carbon 2007; 45: 2098-104. 14. goguta l, marsavina l, bratu d, topala f. impact strength of acrylic heat curing denture base resin reinforced with e-glass fiber. timisora medical j 2006; 56: 88-92. 15. kim sh, watts dc. the effect of reinforcement with woven e-glass fibers on the impact strength of complete denture fabricated with high impact acrylic resin. j prosthet dent 2004; 91: 274-80. 16. pasad h, kalavathy a, mohammed hs. effect of glass fiber reinforcement on impact strength of maxillary complete denture. aedj 2011; 3(4): 7-12. 17. zhou z. augmentation of pmma dbm with multiwalled carbon nanotubes. ms thesis, queen's univ, belfast, ireland, 2009. 18. alwan sa. the effect of the addition of silanized titanium fillers on some physical and mechanical properties of heat cured acrylic denture base material. thesis, university of baghdad, 2014. 19. hartsfield jk, subramani k jr., ahmed w. nanobiomaterial in clinical dentistry elsevier. p50 20. dahham tb. the effect of modified zinc oxide nano fillers addition on some properties of heat cured acrylic resin denture base material. a master thesis, university of baghdad, 2014. 21. ghosh m. a comparative study of flexural strength on microadditions of graphene and carbon nanotubes to polymethylmethacrylate: an invitro study. rajiv gandhi university of health sciences 2013. 22. abdul ameer as. evaluation of changes in some properties of acrylic denture base material due to addition of radio-opaque fillers. a master thesis, university of baghdad, collage of dentistry, 2006. http://dx.doi.org/10.1155/2013/296727 http://www.cefic.org/documents/other/benefits%20of type of the paper (article journal of baghdad college of dentistry, vol. 35 , no. 1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 20 research article effect of a novel coating material on the microleakage of glass hybrid restoration in primary teeth – an in vitro study halah abdulkareem a. alkhawaja 1,*, aseel haidar m.j. al haidar 2 1 master student, department of pediatric and preventive dentistry, college of dentistry, university of baghdad, iraq 2 assistant professor, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. iraq * correspondence: halaalkhawaja2020@gmail.com abstract: background: glass ionomer restorations are widely employed in the field of pediatric dentistry. there is a constant demand for a durable restoration that remains functional until exfoliation. this study aimed to measure and compare the effect of a novel coating material (equia forte coat) on the microleakage of glass hybrid restoration (equia forte ht) in primary teeth. material and method: thirty cavitated (class-ii) primary molars were allocated randomly into two groups based on the coat application; uncoated (control) and coated group (experimental). cavities were prepared by the use of a ceramic bur (cerabur) and restored with equia forte ht with or without applying a protective coat (equia forte coat). samples went through the thermocycling process and dipped in 2% methylene blue dye before being sectioned through the center of the restoration. microleakage was evaluated digitally using software and a camera connected to a stereomicroscope (30 x magnification) to assess dye penetration of the sectioned samples at both the occlusal and gingival marginal levels. results: there was a significant difference between the coated and uncoated groups at both occlusal (p=.029) and gingival margin sites (p=.001). conclusion: higher microleakage values were associated with the uncoated group compared to the coated one. the application of a protective coating to the restorations is an efficient approach to decrease the microleakage of the restorations that can be usefully adopted in clinical practice. keywords: cerabur, equia forte coat, glass hybrid restorative system, microleakage, nano coat. introduction dental caries is the oral disease with the highest incidence and prevalence worldwide, which constitutes an oral public health problem (1). the prevalence of dental caries is high in children across the globe. because primary teeth serve as the foundation for permanent teeth and are highly susceptible to decay, these teeth are considered of utmost significance, and preserving their health is a major health priority (2). the prerequisites for the treatment of decayed primary teeth are conservative tooth preparation and durable restorative materials that remain in function until exfoliation time (3). for the conservative preparation, manufacturers have developed new burs composed of ceramic (cerabur, komet, germany) with the benefits of better tactile feeling and greater excavation capabilities on softened carious dentin while maintaining as much sound dental structure as feasible (4). there is a critical demand to find restorative materials that need fewer steps, less time, and less expense in pediatric dentistry. glass ionomer restorations have been widely employed in this field since they fulfill those requirements (5). glass ionomer-based restorative materials have the advantages of chemically adhering to the tooth structure, anti-cariogenic properties through the release of fluoride, biocompatibility, and minimal thermal expansion (6,7). however, these materials also have shortcomings received date: 10-04-2022 accepted date: 03-06-2022 published date: 15-03-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v35i1.3311 mailto:halaalkhawaja2020@gmail.com https://orcid.org/0000-0002-4936-4927 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3311 https://doi.org/10.26477/jbcd.v35i1.3311 j. bagh. coll. dent. vol. 35, no. 1. 2023 alkhawaja and al haidar 21 compromising restoration durability, such as being moisture sensitive, desiccation intolerant, non-stress-bearing, wear-prone, crack-prone, and excessive porosity (8). to improve the previously existing shortcomings, a glass hybrid-based restoration (equia forte ht) was introduced in 2019. the new hybrid chemical structure and protective coating system (equia forte coat) confer the restoration improvement in physicomechanical properties (9). it is generally accepted that one of the most important factors that determine how long dental restorations will last is marginal leakage at the tooth/restoration interface (10). a restoration with a satisfactory, marginal seal minimizes marginal deterioration, preventing further leakages and secondary caries (11). to compare the effect of equia forte coat on the marginal seal (microleakage), the generated hypothesis was that the applied coating would not influence the microleakage, and the coated group would not significantly differ from the uncoated group. the null hypothesis was compared against the alternative hypothesis. this study aimed to measure and compare the effect of a novel coating material (equia forte coat) on the microleakage of glass hybrid restoration (equia forte ht) in primary teeth. materials and methods preparation of the sample the research ethics committee of the university of baghdad/college of dentistry approved the study (reference number: 333/333321). this study included thirty cavitated (class-ii) primary molar teeth. over-retentive, serially extracted (orthodonticlly), and naturally exfoliated teeth were used for this study. teeth were preserved in a 0.1 solution of thymol after proper prophylactic cleaning until usage (12). any tooth having breaks or malformations was eliminated throughout the sample collecting procedure (13). a single, well-trained operator prepared all the samples. after establishing appropriate access to the carious cavitation by removing carious and undermined enamel using a diamond bur (henry schein, usa)(14), cavities were prepared by ceramic bur (cerabur, komet, germany) mounted on slow speed hand-piece to remove carious tissue selectively. then cavities were washed with water spray, air dried, and a suitable matrix band was applied, preparing them for the restorative procedure. restoration of the samples glass hybrid restoration (equia forte ht) was applied with or without a coat (equia forte coat) according to each group as follows: before the restoration procedure, the cavities were conditioned for 10 seconds with a cavity conditioner acid (gc, japan) containing 20% polyacrylic acid, followed by washing and drying. equia forte ht (gc, japan) capsule was mixed in an amalgam mixer according to the manufacturer's instructions (gc, 2019), and immediately injected via the nozzle into the cavities using the riva applicator (sdi limited, australia). the filling was then contoured, and any excess material was removed using a proper instrument. a water-cooled, superfine diamond bur (henry schein, usa) was utilized to finish the restoration. then, teeth were allocated in a random manner using a simple randomization technique according to the presence of coating into two groups: uncoated (control) and coated group. the restorations in the coated group were then coated with a thin layer of equia forte coat (gc, japan) using a micro brush applicator and light-cured for twenty seconds as per the manufacturer's instructions (gc, 2019). j. bagh. coll. dent. vol. 35, no. 1. 2023 alkhawaja and al haidar 22 microleakage test samples were maintained for 24 hours in a container with distilled water at 37° c. thermal cycling was performed at 5°c and 55°c water baths for 500 cycles with a 30-second dwell time (15). to avoid methylene blue penetration via unfavorable areas, a flowable composite was used to seal the root apices (16), and two coats of nail varnish were applied to the entire tooth except for the restoration and 1 millimeter beyond the margins (17). at 37°c, samples were immersed in a 2% methylene blue dye solution for 24 hours, followed by washing with distilled water and drying (18,19). samples were embedded in acrylic resin blocks and subjected to longitudinal sectioning through the center of the restoration by xp precision sectioning saw (ted pella, usa) in a mesiodistal direction (20). all the generated sections received digital examination using a stereomicroscope (30 x magnification) with a software (optika vision lite 2.1 software) to assess the dye penetration in millimeters at both the occlusal and gingival marginal levels. dye penetration assessment was carried out by two trained examiners with 99% intra and interexaminer agreement (intraclass correlation coefficient), who were blinded to the tested groups. image of each section was obtained using a camera connected to the stereomicroscope, then imported to the software, and the length of methylene blue dye penetration was measured in millimeters. each tooth was represented by the section that recorded the highest dye penetration value (21). statistical analysis the analyses of data were performed with spss version 26.0 software (spss inc., chicago, usa). to determine the level of significance at p < 0.05, groups were compared using the mann-whitney u test. results effect of the coating on the microleakage marginal microleakage values in mm were recorded and analyzed (for both the coated and uncoated groups) at both the occlusal and gingival margin levels, (table 1). the occlusal margin site at the occlusal margin, the mann whitney u test revealed a statistically significant difference between the coated and uncoated groups (p=.029), (figure 1). all of the samples in the coated group exhibited no microleakage (zero values) at the occlusal margin, whereas only 50% of the uncoated group showed no microleakage. the gingival margin site at the gingival margin, the results of the mann whitney u test showed a statistically significant difference between the coated and uncoated groups (p=.001), (figure 1). whereas 60% of the coated group's samples recorded zero value (no microleakage) at the gingival margin, the entire uncoated group showed microleakage. effect of coating on the surface of the filling material it was noticed that the surface appearance of equia forte ht under the microscope showed cracks in the uncoated samples while smooth crackles surface presented in the coated groups. j. bagh. coll. dent. vol. 35, no. 1. 2023 alkhawaja and al haidar 23 table 1: mann whitney u test compares the microleakage between the coated and uncoated cerabur groups at the occlusal and gingival margin sites. site group n mean rank u value p-value significance occlusal coated 15 12 165.0 0.029 s. uncoated 15 19 gingival coated 15 10.33 190.0 0.001 s. uncoated 15 20.67 s=significant at p<0.05 figure 1: microleakage in millimeters of coated and uncoated groups represented by box and whisker plot. discussion primary teeth restoration varies from that of the permanent teeth. the capacity of primary teeth to appropriately support and hold intra-coronal restorations is impaired by the shorter clinical crown heights of these teeth. additionally, the bigger pulp chambers, pulp horns that are nearer to the surface and the wide contact areas are factors that need consideration concerning the restorative procedures (22). glass ionomer (gi) restorations have been used widely in the treatment of primary teeth due to their capacity to chemically adhere to the tooth structure and release fluoride (23). however, the traditional gi materials possess limitations resulting in marginal disintegration, microleakage, and subsequent restoration failure (3). one of the essential requirements for the longevity of restoration is an adequate seal between the tooth and the restoration. a weak marginal seal with subsequent microleakage permits the entrance of bacteria and oral fluids, which might contribute to the formation of secondary caries, hypersensitivity, and pulpal pathology (20,24). various modifications and formulae have been developed in an attempt to improve the traditional gi restorations (3). j. bagh. coll. dent. vol. 35, no. 1. 2023 alkhawaja and al haidar 24 the success of the gi-based equia and equia forte (gc, japan) restorations led to the development of equia forte ht in 2019. it is a novel, capsulated form, glass hybrid substance with a higher viscosity than the previous generations. these glass hybrid materials were created by mixing glass particles of varied sizes with the conventional filler-like, highly reactive, microscopic particles. this property enhances reactivity and physicomechanical properties, making it suitable for long-lasting fillings and allowing an easy bulk placement for stress-bearing class i and ii cavities (9,25). a light-cured nano-filled resin covering equia forte coat is another modification of equia forte ht. according to manufacturers (gc, 2019), this new coat contains nano-fillers that boost mechanical properties and marginal sealing. it also offers protection of the restoration throughout the initial phase of the setting when it is most vulnerable to water absorption or dehydration. over time, the nano-coating is supposed to wear off as the manufacturer (gc, 2019) designed to allow for the second phase of restoration maturation (26). in addition, the coat confers a shiny, smooth finish to the final restoration, which adds to its advantage (19,27). in this study, microleakage was measured and compared in two groups (equia forte ht without and with nano-coating) to assess the effectiveness of the equia forte coat. since equia forte ht is a novel material, no available research was found in the widely distributed literature that specifically measured and compared the microleakage values of equia forte ht with the use of equia forte coat. however, research on previous generations of equia fil and equia forte fil were used to compare the result of this study. concerning microleakage, the results of this study revealed that the equia forte coat was able to inhibit dye penetration at the occlusal margin of all the samples (100%) and showed significantly less leakage at the gingival margin (60%). this might be due to the protective effect of the nano-coating against water absorption and dehydration in the initial setting and the ability of the coat's nanoparticles to tightly seal any surface imperfections resulting in a better marginal seal. these results agreed with gopinath, 2017(28); gaintantzopoulou et al., 2017(3); ali et al., 2019(5); habib et al., 2021(19); alwan and athraa, 2021(29), who concluded that less microleakage was associated with the equia and equia forte restorations with coat application. regarding surface texture, coat application resulted in a smooth, lustrous surface, indicating that the coat filled all the possibly formed cracks. the resulted smooth surface is more durable since crack is the future leading to stress points and facilitating future fracture, microleakage, secondary caries, and subsequent failure of restoration, which emphasizes the use of the coating. further in vitro studies considering mechanical loading (chewing simulator) are recommended. the study result must be confirmed in vivo with follow-up evaluation after a while to assess the duration of coat wear and the restoration status (clinical performance) after the coat wearing. conclusion higher microleakage values were associated with the uncoated group compared to the coated one. the application of a protective coating to the restorations is an efficient approach to decrease the micro j. bagh. coll. dent. vol. 35, no. 1. 2023 alkhawaja and al haidar 25 leakage of the restorations that can be usefully adopted in clinical practice. in addition, the coat imparts a highly glossy texture to the structure of the teeth. conflict of interest: none. references 1. duangthip, d., chu, c.h. challenges in oral hygiene and oral health policy. front oral health. 2020; 1: 575428. 2. kazeminia, m., abdi, a., shohaimi, s., et al. dental caries in primary and permanent teeth in children’s worldwide, 1995 to 2019: a systematic review and meta-analysis. head face med. 2020; 16(1):1-21. 3. gaintantzopoulou, m.d., gopinath, v.k., zinelis, s. evaluation of cavity wall adaptation of bulk esthetic materials to restore class ii cavities in primary molars. clin oral investig. 2017; 21(4): 1063-70. 4. ardeshana, a., bargale, s., karri, a., et al. evaluation of caries excavation efficacy with ceramic bur and hand excavation in primary teeth: an experimental study. j. south asian assoc pediatric dent. 2020; 3: 60-64. 5. ali, a.s., el-malt, m.a., mohamed, e.a. a comparative evaluation of equia forte microleakage versus resin-modified glass ionomer. al-azhar dent j girls. 2019; 6(3): 249-54. 6. sharafeddin, f., shoale, s., kowkabi, m. effects of different percentages of microhydroxyapatite on microhardness of resin-modified glass-ionomer and zirconomer. j clin exp dent. 2017; (6): e805. 7. wiegand, a., buchalla, w., attin, t. review on fluoride-releasing restorative materials—fluoride release and uptake characteristics, antibacterial activity and influence on caries formation. dent mater. 2007; 23(3): 343-62. 8. ilie, n., hickel, r., valceanu, a.s., et al. fracture toughness of dental restorative materials. clin oral investig. 2012; 16(2):489-98. 9. brkanović, s., ivanišević, a., miletić, i., et al. effect of nano-filled protective coating and different ph enviroment on wear resistance of new glass hybrid restorative material. materials (basel). 2021; 14(4): 755. 10. jia, s., chen, d., wang, d., et al. comparing marginal microleakage of three different dental materials in veneer restoration using a stereomicroscope: an in vitro study. br dent j. 2017; 3(1):1-5. 11. fathy, d., el-tekeya, m., bakry, n.s., et al. microleakage evaluation of composite restoration following caries removal using ceramic bur in primary teeth (an in vitro study). alex dent j. 2021; 46: 169-73. 12. kitsahawong, k., seminario, a.l., pungchanchaikul, p., et al. chemomechanical versus drilling methods for caries removal: an in vitro study. braz oral res. 2015; 29: 1-8. 13. majeed, m.a. microleakage evaluation of a silorane-based and methacrylate-based packable and nanofill posterior composites (in vitro comparative study). tikrit j dent sci. 2012; 1(2): 19-26. 14. ali, a.h., thani, f.b., foschi, f., et al. self-limiting versus rotary subjective carious tissue removal: a randomized controlled clinical trial—2-year results. j clin med 2020; 9: 2738. 15. daub, j., berzins, d.w., linn, b.j., et al. bond strength of direct and indirect bonded brackets after thermocycling. angle orthod. 2006; 76(2): 295-300. 16. donmez, n., siso, s.h., usumez, a. microleakage of composite resin restorations in class v cavities etched by er: yag laser with different pulse modes. j laser health acad. 2013; 1: 6-10. 17. sooraparaju, s.g., kanumuru, p.k., nujella, s.k., et al. a comparative evaluation of microleakage in class v composite restorations. int j dent 2014; 2014: 685643. 18. dhingra, v., taneja, s., kumar, m., et al. influence of fiber inserts, type of composite, and gingival margin location on the microleakage in class ii resin composite restorations. oper dent. 2014; 39: e9-e15. 19. habib, s.i., yassen, a.a., bayoumi, re. influence of nanocoats on the physicomechanical properties and microleakage of bulk-fill and resin-modified glass ionomer cements: an in vitro study. j contemp dent pract. 2021; 22(1): 62-8. j. bagh. coll. dent. vol. 35, no. 1. 2023 alkhawaja and al haidar 26 20. hafez, m.a., elkateb, m., el shabrawy, s., et al. microleakage evaluation of composite restorations following papain-based chemo-mechanical caries removal in primary teeth. int j clin pediatr dent. 2017; 41: 53-61. 21. sharafeddin, f., yousefi, h., modiri, s., et al. microleakage of posterior composite restorations with fiber inserts using two adhesives after ging. j dent (shiraz) 2013; 14: 90-5. 22. american academy of pediatric dentistry reference manual. american academy of pediatric dentistry, 2008. 23. vishnurekha c, annamalai s, baghkomeh p.n, et al. effect of protective coating on microleakage of conventional glass ionomer cement and resin-modified glass ionomer cement in primary molars: an in vitro study. indian j dent res. 2018; 29(6): 744-748. 24. mousavinenasab, s.m., jafary, m. microleakage of composite restorations following chemo-mechanical and conventional caries removal. front dent. 2004: 1(4): 12-7. 25. valeri, a. in vitro wear of glass-ionomer containing restorative materials: (doctoral dissertation, the university of north carolina at chapel hill). 2021. 26. kielbassa, a.m., oehme, e.p., shakavets, n., et al. in vitro wear of (resin-coated) high-viscosity glass ionomer cements and glass hybrid restorative systems. j dent. 2021; 105: 103554. 27. basso, m., brambilla, e., benites, m.g., et al. glassionomer cement for permanent dental restorations: a 48-months, multi-centre, prospective clinical trial. stoma edu j. 2015; 2(1): 25-35. 28. gopinath, v.k. comparative evaluation of microleakage between bulk esthetic materials versus resin-modified glass ionomer to restore class ii cavities in primary molars. j indian soc pedod prev dent. 2017; 35(3): 238. 29. alwan, s.q., al-waheb, a.m. effect of nano-coating on microleakage of different capsulated glass ionomer restoration in primary teeth: an in vitro study. indian j forensic med toxicol. 2021; 15(4): 2674-2684. مختبرية دراسة اللبنية األسنان فيمهجنة ال glassحشوةل الدقيق التسرب على جديدة واقية مادة تأثير العنوان: 2حيدر محمد جواد الحيدرأسيل , 1الخواجة عبدالمجيد هاله عبدالكريم الباحثون: المستخلص: واستبدالها األسنان هذه سقوط موعد حتىتبقى فعالة ر للحصول على حشواتمستم طلب كلهنا. األطفال أسنان طب مجال في واسع نطاق على glass ionomerحشوات ال تستخدمالخلفية: األسنان في (equia forte ht)مهجنة الglass لحشوة الدقيق التسرب على( equia forte coat) جديدة واقية مادة تأثير ومقارنة قياس إلى الدراسة هذه هدفت. ةيالدائم باألسنان .اللبنية المطلية غير المجموعة ؛ الطبقة الواقية تطبيق على بناء مجموعتين إلى عشوائية بطريقةوتقسيمها ( الثانية الفئة) التجاويف المتسوسة ذات اللبنية األسنان من ثالثين استخدام تمالمواد وطرق العمل: بدون أو مع equia forte ht باستخدام حشوتها وتم( cerabur)سنبلة مصنوعة من السيراميك بواسطة التجاويف تحضير تم(. التجريبية المجموعة) والمطلية( الضابطة المجموعة) الدقيق التسرب تقييم تم. قطعها من منتصف الحشوة يتم أن قبل٪ 2بتركيز زرقاءال ميثيلينال صبغة في هاغمستم و الحراري التدوير بعملية العينات مرت(. equia forte coat) واقية طبقةال .واللثوي اإلطباقي الهامشي المستويين على المقطوعة العينات في الصبغة تغلغل لتقييم×( 30 تكبير) مجسم بمجهر متصلة وكاميرا برنامج باستخدام رقمي ا (. p = .001) وياللثو( p = .029) ياإلطباق الهامشي المستويين من كل في المطلية وغير المطلية نمجموعتيال بين كبير معنوي فرقتم العثور على : النتائج يمكن التي للحشوات و الدقيق التسرب لتقليل فعالة طريقة الحشوات على واقيةال طبقةال تطبيق يعد . المطلية بالمجموعة مقارنة المطلية غير بالمجموعة الدقيق لتسربل العالية قيمال ارتبطت االستنتاج: . السريرية الممارسة في مفيد بشكل اعتمادها j bagh college dentistry vol. 31(3), september 2019 salivary vitamin 39 salivary vitamin e and uric acid in patients with olp and healthy individuals adel jasim mohammed, b.d.s., h.d.d.(1) ameena ryhan diajil, b.d.s., m.sc., ph.d.(2) abstract background: oral lichen planus (olp) is a t-cell mediated chronic inflammatory oral mucosal disease of unknown etiology. recent studies have reported an increased oxidative stress and lipid peroxidation in such patients. this suggests that reactive oxygen species may have a role in the pathogenesis of lichen planus. oxidative stress in olp release molecules consisting of granzymes resulting in local tissue damage in the effectors. antioxidants that can defend against oxidative stress in the body cells include enzymes, as well as nonenzymatic antioxidants, such as melatonin, uric acid, vitamin a and e. purpose: to study the level of salivary vitamin e and uric acid as antioxidant agents in patients with olp and compared with healthy control. methods: twenty five patients with olp were enrolled in this study. age, gender, occupation, smoking status (smokers or non-smokers), lesion types, duration, location and size were recorded for each patient. after an oral examination, salivary samples were collected and flow rates (ml/min) were recorded. the collected samples were centrifuged at 3000 rpm for 10 minutes; the clear supernatants were separated and stored frozen at (-20 c) until analysis. then salivary vitamin e was investigated using elisa kit based on bioten double antibody sandwich technology . uric acid was analyzed using a proprietary enzymatic reaction mixture that enables the detection of uric acid by the production of a red chromogen, which is quantitatively measured at a wavelength of 515 or 520 nm . results: the mean age of olp patients was 48.3 years with a range of 30-60 years. control group consisted of 35 healthy subjects who were age matched with olp patients. fourteen (56%) patients were with reticular and 11 (44%) were with erosive form, with the buccal mucosa was the most commonly affected site (88%), followed by tongue (8%) then gingiva (4%). a significantly lower salivary flow-rate, lower salivary vitamin e and uric acid level in olp patients compared to control; while, no significant difference was seen between reticular and erosive type of olp for both vitamin e and uric acid level. regarding gender, no differences were found between males and females in salivary vitamin e. no significant correlation was found between vitamin e /uric acid and age. similarly, no difference was found between males and females in uric acid. conclusion: salivary anti-oxidant markers represented by vitamin e and uric acid decreased in olp patients due to increase oxidative stress which may have an important role in the pathogenesis. thus, it is recommended to give olp patients anti-oxidant agents that may either help in healing process or decreased the severity. key words: olp, saliva, vitamin e, uric acid.. (received: 10/1/2019; accepted: 19/2/2019) introduction oral lichen planus (olp) is a t-cell mediated chronic inflammatory mucosal disease of unknown etiology (1). it is clinically presented as reticular, popular, plaque, erosive, atrophic or bullous types (2). the exact pathogenesis is unknown, but cell mediated and humoral immunity has been implicated (3). activation of the cellmediated immune response destined toward keratinocyte apoptosis is the prime event in the pathogenesis of olp. the process involves three sequential stages; lpspecific antigen recognition, cytotoxic lymphocyte activation and keratinocyte apoptosis (3,4). oxidative stress in olp release molecules consisting of granzymes that may result in local tissue damage in the effectors (5). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. antioxidants present in the mammalian cells can defend against oxidative stress. these include enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, as well as nonenzymatic antioxidants, including melatonin, uric acid, and vitamin a and e (6,7). increased oxidative stress and lipid peroxidation in patients with lichen planus has been reported (8). this may suggest a role of reactive oxygen species in the pathogenesis of lichen planus. antioxidant therapy strategies aimed to protect keratinocyte against damage, independent of disease progression, can be used on knowledge of the molecular aspects of oxidative stress in numerous diseases, including olp (9). some researchers suggest that oral use of antioxidants or antioxidant medications may successfully inhibit increased oxidative stress, and thus may help clinical improvement of disease (10). materials and methods participants sixty subjects were participated in this study; twenty-five oral lichen planus patients who were j bagh college dentistry vol. 31(3), september 2019 salivary vitamin 40 diagnosed clinically and histopathologic ally as an oral lichen planus, and thirty-five healthy looking volunteers as a control group who were age matched with olp patients. the study was approved by the ethics committee of oral diagnosis department in the college of dentistry –university of baghdad. method of saliva collection: salivary samples collection and histopatholgical study was done in imam hussain medical city/ kerbala dermatology department during the period from january to may 2017. saliva collection was started after the clinical examination. saliva was collected from all participants under the same circumstances (20). saliva was allowed to accumulate in the mouth and to expectorate all saliva formed over five minutes period into a sterile graduated test tube. the saliva samples of all the participants were identified by a code number during the period of s collection and processing. after the disappearance of the salivary froth, the salivary flow rate was measured in millilitres per minutes. samples were stored at 80°c, until analyzed. samples collection was limited to the hours between 8:00 and 11:00 am to minimize the effect of diurnal variations. salivary vitamin e was measure using elisa kit (shanghai yuhua biological technology); salivary uric acid was estimated using enzymatic assay kit. a description about the purpose and aim of the study was performed for participants. the study was carried out using a structured case sheet; the first part was related to the demography regarding name, age, gender, occupation and marital statutes. the second part involved clinical oral examination that carried out under natural light using disposable plane mouth mirrors. oral examination was performed by the same examiner. inclusion criteria of the current study include patients who were clinically and histologically diagnosed as an olp exclusion criteria were patients having any systemic treatment suppressing the immune system such as systemic steroids or other immunosuppressive agents, as well as nsaids, antimalarial, diuretics, antihypertensive, antibiotics, and antifungals for the last 4 weeks and topical medications for last 3 weeks prior to sample collection. also, patients with a history of trauma or any surgery 4 weeks prior to sampling, and those who were suffering from any systemic or dermatological disease affecting the immune system or any malignancy. furthermore, smoker patients were also excluded from this study. statistical analysis statistical analysis was performed with spss version 19.0. descriptive statistical analysis, student t-test, analysis of variance (anova) and linear and multiple linear correlation were used. a p-value of less than 0.05 was considered to indicate statistical significance. results age and gender: twenty -five patients were with olp (14 were females and 11 were males).the mean age was 48.3 years with an age range of 30-60 years. the control group consisted of 35 healthy subjects (20 were females and 15 were males) with an age range of 38-60 years and a mean of 48.2 years. occupation: the majority of olp patients were workers (18; 72%) followed by house wives (4; 16%) and officers 3(12%). similarly, in control group subjects, 26(74%) were workers, 6(17%) were house wives, and 3(8%) were officers. oral lichen planus findings: oral lichen planus patients were divided into two subgroups according to the clinical presentation of the lesions at first presentation, 14 patients were with reticular form (56%) and 11 patients were with erosive form of olp (44%). location: the present study showed that buccal mucosa was the most common affected site (88%), followed by tongue (8%) then gingiva (4%). in reticular form, buccal mucosa represented 86 % of the affected site followed by tongue 14%. while in erosive form of olp, buccal mucosa represented 91% of the affected sites followed by gingiva 9%. size in this study, the size of the olp lesion was divided into three categories: 1.5, 2.5 and 3.3 cm. the majority of the reticular type of olp was 1.5 cm in diameter, followed by 2.5 cm. in relation to the erosive type, the majority of olp lesions were 1.5 cm followed by 2.5 cm in diameter. salivary flow rate (f/r): regarding salivary f/r, the present study showed a significant difference between the control and olp patients (p=0.001); salivary f/r is significantly lower in olp patients (0.04±0.06) compared to the control (0.05±0.02) (p=0.001 ) in relation to the subgroups, there is no significant difference between reticular and erosive type of olp in salivary flow rate. oral health status j bagh college dentistry vol. 31(3), september 2019 salivary vitamin 41 oral health status was divided into three scores: fair, moderate and good. the majority of patients with reticular form of olp were seen with fair oral hygiene 6(43%) followed by 4(28.5%) moderate with similar number with good hygiene status. in relation to erosive form of olp, 6 (43%) were observed with a fair oral hygiene, 3 (27 %) with moderate, and 2 (18 %) were seen with a good oral hygiene status. salivary vitamin e (pg/ml): regarding salivary vitamin e, the present study showed a significant difference between olp patients and control group; olp patients showed lower salivary vitamin e level (18.08 pg/ml) compared to control subjects (20.32 pg/ml)( p=0.001),figure 1. in relation to olp subgroups, there is no significant difference between reticular and erosive type of olp in vitamin e level. figure 1: mean salivary vitamin e in olp patients and healthy subjects salivary uric acid a significant difference in salivary uric acid level was fond between control and olp patients; patients with olp showed lower mean levels of salivary uric acid (2.17 mg/dl) compared to healthy control subjects (5.32 mg/dl) (p=0.0001) or (p‹ 0.01), figure2. regarding olp subgroups, there was no significant difference between reticular and erosive types of olp. figure 2: mean salivary uric acid in olp patients and healthy subjects. discussion vitamin e is the major lipid-soluble antioxidant in the cell antioxidant defense system and is exclusively obtained from the diet. the term "vitamin e" refers to a family of eight naturally occurring homologous that are synthesized by plants from homogentistic acid (11). the major biologic role of vitamin e is to protect poly unsaturated fatty acids and other components of cell membranes and low-density lipoprotein (ldl). vitamen e is located primarily within the phospholipid bilayer of cell membranes. it is particularly deterioration of poly unsaturated fatty acids. elevated levels of lipid peroxidation associated with numerous diseases and clinical conditions (12). the results showed statistically significant reduction in the level of vitamen e in olp patients in comparism with healthy subjects. many studies have been done to determine the level of antioxidant in patients with lichen planus and other autoimmune disease (13;14;15). in many of them, decrease in the production of antioxidants has been implicated in the etiology of lichen planus and lichenoid reactions which is agreed with the present study. pathophysiology of olp is multifarious associated with pathognomonic characteristics and degeneration of cells which is supported to be certified to associate epithelial permeation of tlymphocytes leading to local production cytokines (16). recently, it has been stated that imbalance in free radical and ros with antioxidants may play an important role in the initiation of several inflammatory oral disease (14). ros and tissues oxidative damage, following extend a lack of antioxidants may result in appearance of this disease (15; 17). the age incidence of olp as stated in selected previous studies suggests that this disease is most commonly seen in the fifth decade of life (15; 18). uric acid is one compound of catabolism purine nucleotides is a main significant antioxidants and also a powerful free radical scavenger in human biological fluids. the present study showed a significant decrease in salivary uric acid for olp patients when compared with healthy individuals which is agreed with previous studies (19). the problem of oxidative stress and free radicals in olp should be examined in studies with larger number of patients, and with other indicators of oxidative stress and antioxidants to support the present study findings. also, the results of this study may indicate that olp may be related to decrease of ua concentration in saliva. ua may be considered as a useful biomarker of antioxidant status for difficulty of treatment strategy and monitoring process in olp patients. low levels of total antioxidant are known to disturb its balance 16 17 18 19 20 21 20.32 18.08 m e a n v it a m e n e l e v e l( p g /m l) control olp patients 0 2 4 6 5.32 2.17 m e a n s a li v a ry u ri c a ci d l e v e l( m g /d l) control olp patients j bagh college dentistry vol. 31(3), september 2019 salivary vitamin 42 to oxidative stress parameter (20). thus, further studies are required to see if ua level in saliva may play a role in treatment of olp. references 1. ropashree mr,gondhalekar rv,shashikanth mc,george j, thippeswamy sh, shukla a. pathogenesis of oral lichen planus. a review. j oral pathol med 2010; 39(10): 729-34. 2. neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology. 2nd edition. w.b. saunders company, 2002. 3. daoud ms, wakid mr. lichen planus. in: irwin mf, eisen az, wolf k, austen kf, goldsmith la, katz si.(eds.). fitzpatrick,s dermatology in general medicine, sixth ed. mcgrawhill, new york, 2003, p. 463-477. 4. middel p, lippert u, hummel km, bertsch hp, artuc m, schweyer s, radzun h-j. expression of lymphotoxinby keratinocytes: a further mediator for the lichenoid reaction. pathobiology 2000; 68(4): 291300. 5. scrobotăl i, mocan t, cătoi c, bolfă p. mureşan a, băciuţ g. histopathological aspects and local implications of oxidative stress in patients with oral lichen planus. rom j morphol embryol 2011; 52(4): 1305-9. 6. nagler rm, klein i, zarzhevsky n, drigues n, reznick az. characterizatin of the differentiated antioxidant profile of human saliva. free radic biol med 2002;32(3): 268-277. 7. momenbeitollahi j, mansourian a, momen-heravi f, amanlou m, obradov s, sahebjamee m. assesment of salivary and serum antioxidant status in pateints with recuurent aphthous stomatitis. med oral patol oral cir bucal 2010; 15(4): 557-61. 8. anshumalee n, shashikanth mc. efficacy of oral lycopene in management of lichen planus [dissertation]. rajv ghandi university of health sciences. bangalore. 2007; 91-119. 9. iqubal maa, khan m, kumar p, ajai k. role of vitamin e in prevention of oral cancer: a review. j clin diagn res 2014; 8(10): ze05-ze07. 10. de gutierrez er, di fabio a, salomon s, lanfranchi h. topical treatment of orallichen planus with anthocynins. med oral patol oral cir bucal 2014; 19(5): 459-66. 11. scott g. antioxidants in science, technology, medicine and nutrition. chichester, abion publishing,1997. 12. kagan ve. lipid peroxidation. eur j clin nutr 1998; 4:759-764. 13. nagao t, warnakulasuria s, ikeda n, fukano h, yamamuto s, yano m, miyazaki h, ito y. serum antioxidant micronutrient levels in oral lichen planus. j oral pathol med 2001 30: 264-7. 14. agha-hosseini f, mirzaii-dizgah i, mikaili s, abdollahi m, abdolahi m. increased salivary lipid peroxidation in human subjects with oral lichen planus. in j dent hyg 2009; 7(4): 246-50. 15. updhay rb, carmelio s, shenoy rp, gyawali p, mukherjee m. oxidative stress and antioxidant defense in oral lichen planus and oral lichenoid reaction. scand j clin lab invest 2010; 70(4): 225-8. 16. khan a, farah cs, savage nw, walsh lj, harbrow dj, sugerman pb. th1 cytokines in oral lichen planus. j oral pathol med 2003; 32:77-83. 17. batu s, ofluoğlu d, ergun s, warnakulasuria s, uslu e, gȕven, y, tanyeri h. evaluation of prolidase activity and oxidative stress in patients with oral lichen planus and oral lichenoid contact reactions. j oral pathol med 2016; 45(4): 281-8. 18. scrobotă i, mocan t, cătoi c, bolfă p, mureşan a, băciuţ g.. histopathological aspects and local implications of oxidative stress in patients with oral lichen planus. rom j morphol embryol 2011; 52(4): 1305-1309. 19. battino m, greabu m, tatan a, bullon p, bucur a, palatos i, spinu t, totan c. oxidative stress markers in oral lichen planus. biofactors. 2008; 33(4): 301-10. 20. serafini m, villano d, spera g. pellegrini n. redox molecules and cancer prevention: the importance of understanding the role of the antioxidant network. nutr cancer 2006; 56(2): 232-40. j bagh college dentistry vol. 31(3), september 2019 salivary vitamin 43 الخالصه: الحديثه ان هنالك زياده الحزاز المسطح الفمي هو مرض التهابي مزمن يصيب الطبقه الطالئيه من الفم ويحدث السباب غير معروفه. لوحظ في الدراسات الخلفيه: ي قد \لك نوع االوكسجين التفاعلي لربما له دور في النشوء المرضي. الجهد التاكسدي يحرر انزيمات وال\ في الجهد التاكسدي لدى مرضى الحزاز المسطح, و ك catalase,superoxideجسم تتضمن انزيمات مثل مضادات االكسده التي يمكن ان تعمل ضد الجهد التاكسدي في خاليا ال يؤدي الى ضرر النسيج المحلي. dismutaseوglutathone باالضافه الى مضادات االكسده غير االنزيميه والتي تشملmelatonin,uric acid, فيتامين اي و فيتامينa سطح و مقارنة دلك بالمجموعه الضابطهلدراسة مستوى فيتامين اي و حامض اليوريك في اللعاب كعناصر مضاده لالكسده في مرضى الحزاز الم :الغرض : شارك في هده الدراسه خمسه و عشرون مريضا خضعوا للفحص النسيجي لتلكيد التشخيص وتم تقسيمهم الى مجموعتين اعتمادا على الوصف طريقة العمل الفمي التاكلي باالضافه الى المجموعه الضابطه والتي السريري للحاله, اربعة عشر يمثلون الحزاز المسطح الفمي الشبكي و احد عشر يمثلون الحزاز المسطح تتكون من خمسه وثالثون شخصا من االفراد االصحاء المطابقين من حيث العمر.وقد تم تجميع عينات اللعاب لغرض تحليل النتا ئج. شخص سليم. طبقا لالعراض السريريه 35ت سنه.المجموعه الضابطه شمل 60-30ويتراوح بين 48,3متوسط عمر مرضى الحزاز المسطح كان :النتائج %(. اغلبية 4%( ثم اللثه)8%( يليها اللسان)88%( من النوع التاكلي, بطانة الفم هي الموقع االكثر تاثرا )44) 11%) كانوا من النوع الشبكي, و 56(14للمرض, حزاز المسطح كانوا عمال و غير مدخنين و ال توجد اي عالقه هامه بين التدخين سم. اغلبية مرضى ال 3,5سم و بعدها 2,5سم في القطر ثم 1,5قياس كال النوعين لوحظ ان مستوى كمية فيتامين اي و حامض اليوريك اقل في المرضى مقارنة باالصحاء, بينما ال توجد اختالفات بين النوع الشبكي وحجم الحزاز احصائيا. ليوريك(. بالنسبه للجنس, ال اختالفات توجد بين الدكور واالناث في كمية فيتامين اي وكدلك حامض اليوريك في والتاكلي لكال مضادات االكسده)فيتامين اي,حامض ا اللعاب, وال يوجد ارتباط مهم بين فيتامين اي والعمر. يادة االجهاد التاكسدي )زياده في نوع : كمية مضادات االكسده في العاب بالنسبه لفيتامين اي, حامض اليوريك تقل في مرضى الحزاز المسطح بسبب زالخاتمه التي تساعدهم التفاعل االوكسجيني( ودلك لربما له دور مهم في نشوء مرض الحزاز المسطح. ولدلك يوصى بان يدعم مرضى الحزاز المسطح بمضادات االكسده و اما في الشفاء او التقليل من حدة المرض. j bagh college dentistry vol. 28(4), december 2016 immunohistochemical oral diagnosis 68 immunohistochemical expression of endocan in ameloblastoma salam n. jawad, b.d.s., m.sc. (a) bashar h. abdullah, b.d.s., m.sc., ph.d. (b) abstract background: ameloblastoma is the most common clinically significant odontogenic tumor, known for its locally invasive potential and frequent recurrences unless treated radically. endocan is a soluble proteoglycan which is reported to have prognostic implications in multiple human diseases and tumors. this study aims to describe the expression of endocan in ameloblastoma. materials and methods: with immunoperoxidase method; tissue sections of formalin fixedparaffin embedded blocks for ameloblastomas were stained with monoclonal antibodies to endocan, the localization of the endocan expression was examined and the resulting scores of the tissue sections were analyzed according to age, sex, site and tumor subtype. results: endocan was found to be expressed in peripheral and central epithelial cells of ameloblastoma tumor islands and stroma to different extents; a selectively increased expression was noted in epithelial cells with acanthomatous differentiation. tumor epithelial cells of plexiform subtype tend to have higher expression levels of endocan. however, the associations did not reach statistically significant levels. conclusions: endocan is expressed specifically in various populations of tumor epithelial cells and stromal elements of ameloblastoma. the prognostic significance of the expression needs to be clarified in further studies. keywords: ameloblastoma, endocan. (j bagh coll dentistry 2016; 28(4):68-71) introduction amid odontogenic tumors; ameloblastoma (ab) is characterized to be the most common (1). except for the cystic subtype; it grows in an invasive fashion that often extends beyond radiographic borders (2), its local behavior prompt the clinicians for a radical surgical treatment (3). esm-1 (endothelial cell specific molecule-1) or as called later (endocan) is a dermatan sulphate proteoglycan that was first described in 1996 , it is a peculiar molecule that circulate freely in the blood stream in addition to its expression in endothelial cells. experimental evidence showed that it plays a definite role in inflammation and tumor progression (4, 5). immunohistochemical expression of endocan was examined in multiple human normal tissues including lung (4), liver, brain, kidneys, skin and myocardium (6) and was expressed and positively related with the unfavorable outcome of several neoplastic processes such as pituitary adenoma (7), hepatocelular (8), ovarian (9) and colon carcinomas (10). this study aims to evaluate the immunohistochemical expression and localization of endocan in ameloblastoma in relation to age, sex, site and histological subtypes. (a)ph.d. student. department of oral diagnosis, college of dentistry, university of baghdad. (b) professor. department of oral diagnosis, college of dentistry, university of baghdad. materials and methods the study involved thirty seven archival formalin fixed-paraffin embedded tissue blocks of ab that were retrieved from the laboratory of the college of dentistry/baghdad university and the medical city laboratories. five um thick tissue sections of the blocks were mounted on positively charged slides, dewaxed and rehydrated in xylene and serial dilutions of ethanol. endogenous peroxidase activity and nonspecific antibody binding were blocked with h2o2 and protein block respectively then, a monoclonal antibody to endocan (ab56914; abcam, cambridge, uk) with a concentration of 1:2000 was added to tissue section and incubated for 2 hours at 37˚c then, “complement” and “conjugate” solutions of the (expose mouse and rabbit specific hrp/dab detection ihc kit , ab80436; abcam inc., cambridge, uk) were added to tissue sections and incubated for 10 and 15 minutes respectively. the antibody binding was finally visualized with dab chromogen and counterstained with mayer’s hematoxylin. a positive control of a normal lung was included into each immunohistochemical run and a negative control section was selected in each slide that was stained with the omission of the primary antibody. two pathologists examined at least 5 high power fields of each stained tissue section independently, tumor epithelial and stromal expression was classified semiquantitatively to a 4 tiered scores where tissue sections with 0-24% positivity classified as negative, 25-49% as (+), 50-74% as (++) and 75% and above as (+++) (10). j bagh college dentistry vol. 28(4), december 2016 immunohistochemical oral diagnosis 69 statistical analysis was performed with spss.22 statistical software employing one way anova, mann-whitney and kruskal-wallis tests. test results with p values less than 0.05 were considered significant. results the mean age of the study sample was slightly more than 35 years with a predominance of females. the study included four maxillary and 33 mandibular cases. about eighty percent of the study sample was represented by solid ab that was further subdivided into follicular (56.8%), plexiform (16.2%) and acanthomatous (5.4%). the remaining 21.6% were of the cystic type (table 1). an intense cytoplasmic and nuclear epithelial expression was found within peripheral ameloblast like cells and stellate reticulum like cells. table 1: study sample characteristics variable value total (%) 37 (100%) age (mean±sd) 35.16(±16.26) gender males 12 (32.4%) females 25 (67.6%) m: f ratio 0.48:1 site mandible 33 (89.2%) maxilla 4 (10.8%) histologic subtype sol fol 21 (56.8%) plex 6 (16.2%) acan 2 (5.4%) cys 8 (21.6%) sol, solid; fol, follicular; plex, plexiform; acan, acanthomatous; cys, cystic areas with acanthomatous differentiation showed selective antibody positivity as well. stromal expression was noticed in a diffuse manner, accentuated at vascular endothelial cells, fibroblasts and focal inflammatory cells (figures1: a, b, c and d). figure 1: high power photomicrograph depicting immonohistochemical expression of endocan in follicular (a), plexiform (b), cystic (c) and acanthomatous (d) ameloblastomas (x40; scale bar = 100 um). as it is detailed in tables 2 and 3; scored endocan tumor epithelial and stromal expression showed no significant correlation with age. maxillary cases had a notably higher stromal expression than mandibular cases that did not reach statistically significant level. mean tumor epithelial expression in males was higher than females and barely missed significance whereas stromal expression showed an opposite nonsignificantly higher expression in females. though statistically non-significant; cystic ab showed a higher expression in mural (n=1), luminal (n=5) and intraluminal (n=2) areas than solid subtypes in general with respect to tumor epithelial and stromal parts (p=0.77; p=0.09 respectively). within solid ab, the highest mean expression values were found in plexiform j bagh college dentistry vol. 28(4), december 2016 immunohistochemical oral diagnosis 70 subtype for tumor epithelial part and in the follicular subtype for the stromal part. table 2: mean scores of endocan expression in epithelial parts of ameloblastoma against age, sex, site and subtype table 3: mean scores of endocan expression in stromal parts of ameloblastoma against age, sex, site and subtype sub, subtype; fol, follicular; plex, plexiform; acan, acanthomatous; cys, cystic; €, anova test; ¥, mann-whitney test; ɨ, kruskal-wallis test. discussion despite it has been characterized to tag vascular endothelial cells (4,5); endocan is known to be expressed in multiple tissue components including epithelial cells of gastrointestinal tract, renal tubules, respiratory alveoli and epithelia of normal skin and adnexal structures (6). in this study, it was shown to be expressed in a variable extent within tumor epithelial islands at both peripheral ameloblast like cells and inner stellate reticulum like cells denoting a harmonious endocan immunoprofile within the tumor islands’ various locations, however; a slightly increased selective expression was noted at epithelial cells with acanthomatous differentiation, although it did not substantially affect the overall expression values of acanthomatous subtype; such pattern of expression marks an intricate presence of the antigen among subsets of tumor epithelial cells with variable differentiation. an earlier study by zhang et al.(6) suggested that endocan expression is associated with neogenesis or in tissue parts that are in a non quiescent state, an observation that is substantiated by several studies that demonstrated endocan as a soluble circulating marker for aggressiveness in disease processes and outcome of neoplastic conditions (5,7-9). tumor epithelial expression of endocan in ab found in this study does not depart from this general notion since that ab is a relentless tumor with a capacity for growth, invasion and a remarkable recurrence potential (3). although it is reported to harbor a vascular stroma (11); plexiform subtype of ab had a lower stromal endocan score than other subtypes in this study, however; it had the highest tumor epithelial scores which could denote a trend toward aggressive behavior aside from its stromal components. nevertheless; the small number of tumor epithelium (n=37) + ++ +++ mean score (±sd) p age (mean±sd) 0 24.0 (±10.39) 34.71 (±11.31) 36.52 (±17.67) 35.16(±16.26) 0.461€ sex m 0 0 1 11 2.92(±0.289) 0.073¥ f 0 3 6 16 2.52(0.714) site max. 0 0 2 2 2.5(±0.577) 0.378¥ mand. 0 3 5 25 2.67(±0.645) sub sol fol 0 3 3 15 2.57(±0.746) 2.62(±0.677) (among all)=0.824ɨ (sol vs cys)=0.776¥ plex 0 0 1 5 2.83(±0.408) acan 0 0 1 1 2.5(±0.707) cys 0 0 2 6 2.75(±0.463) total 0 3 7 27 2.65(±0.63) stroma (n=37) + ++ +++ mean score(±sd) p age(mean±sd) 25 21.33 (±3.51) 33.4 (±13.03) 38.17 (±17.91) 35.16(±16.26) 0.336€ sex m 1 2 1 8 2.33(±1.07) 0.896¥ f 0 1 9 15 2.56(±0.58) site max. 0 0 0 4 3.0(±0.0) 0.111¥ mand. 1 3 10 19 2.42(±0.792) sub sol fol 0 2 6 13 2.52(±0.680) 2.38(±0.82) (among all)=0.157ɨ (sol vs cys)=0.09¥ plex 1 1 2 2 1.83(±1.169) acan 0 0 1 1 2.5(±0.707) cys 0 0 1 7 2.88(±0.354) total 1 3 10 23 2.49(±0.77) j bagh college dentistry vol. 28(4), december 2016 immunohistochemical oral diagnosis 71 each subtype within this study sample precludes a conclusive result in this context. another notable finding is that cystic ab had a relatively high mean score when compared to the collective mean of solid subtypes; it actually approached significant levels of difference in stromal expression, keeping in mind that cystic ameloblastomas are much less aggressive than solid ones (11,12), this expression pattern may point to either an inverse relation to the outcome or that stromal expression of endocan is of no value in ab, nevertheless; these presumptions that to be accentuated in a more detailed studies. finally, to the best of the authors’ knowledge; no previous studies were found that addresses the expression of endocan in ameloblastomas. this study showed the presence of endocan antigen in ab epithelial and stromal elements in addition to its potential for behavioral discrimination which would need further clarification. references 1johnson nr, gannon om, savage nw, batstone md. frequency of odontogenic cysts and tumors: a systematic review. j invest clin dent 2014; 5: 9–14. 2macdonald-jankowski ds, yeung r, lee k m, li tk. ameloblastoma in the hong kong chinese. part 2: systematic review and radiological presentation. dentomaxillofac radiol 2004; 33: 141–51. 3hertog d, schulten ea, leemans cr, winters ha, van der waal i. management of recurrent ameloblastoma of the jaws; a 40-year single institution experience. oral oncol 2011; 47:145-6. 4lassalle p, molet s, janin a, van der heyden j, tavernier j, fiers w, tonnel ab. esm-1 is a novel human endothelial cell-specific molecule expressed in lung and regulated by cytokines. j biol chem 1996: 271: 20458-64. 5sarrazin s, adam e, lyon m, depontieu f, motte v, landolfi c, delehedde m. endocan or endothelial cell specific molecule-1 (esm-1): a potential novel endothelial cell marker and a new target for cancer therapy. biochim biophys acta (bba)-reviews on cancer 2006; 1765: 25-37. 6zhang sm, zuo l, zhou q, gui sy, shi r, wu q, wang y. expression and distribution of endocan in human tissues. biotech histochem 2012; 87: 172-8. 7cornelius a, cortet‐rudelli c, assaker r, kerdraon o, gevaert mh, prévot v, maurage ca. endothelial expression of endocan is strongly associated with tumor progression in pituitary adenoma. brain pathol 2012; 22: 757-64. 8ziol m, sutton a, calderaro j, barget n, aout m., leroy v, ganne-carrié n. esm-1 expression in stromal cells is predictive of recurrence after radiofrequency ablation in early hepatocellular carcinoma. j hepatol 2013; 59: 1264-70. 9el behery mm, seksaka ma, ibrahiem ma, saleh hs, el alfy y. clinicopathological correlation of endocan expression and survival in epithelial ovarian cancer. arch gynecol obstet 2013; 288: 1371-6. 10kim jh, park my, kim cn, kim kh, kang hb, kim kd, kim jw. expression of endothelial cell-specific molecule-1 regulated by hypoxia inducible factor-1α in human colon carcinoma: impact of esm-1 on prognosis and its correlation with clinicopathological features. oncol rep 2012; 28: 1701-8. 11neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology. 3rd ed. philadelphia: saunders; 2008. pp. 702–9. 12saravanakumar b, parthiban j, aarthi nv, sarumathi t, prakash ca. unicystic ameloblastoma of the mandible–report of two cases with review of literature. journal of clinical and diagnostic research: jcdr 2014; 8: zd07. dropbox 7 abeer f 36-43.pdf simplify your life dropbox 1 abeer f 1-8.pdf simplify your life lehadh f.doc j bagh college dentistry vol. 25(2), june 2013 expression of ki67 and oral diagnosis 76 expression of ki67 and p53 as proliferation and apoptosis markers in adenoid cystic carcinoma lehadh m. al-azzawi, b.d.s., m.sc., ph.d. (1) abstract background: adenoid cystic carcinoma (acc) constitutes about 4% of salivary epithelial tumors and is the second common malignant epithelial salivary gland tumor involving both the major and minor salivary glands. aims of the study is to evaluate immunohistochemical expression of ki67 and p53 proteins in acc. materials and methods: immunohistochemical analyses of fifteen cases of formalin – fixed paraffin – embedded tissues blocks of acc of salivary glands using ki67 and p53 antibodies. results: ki67 was expressed in 6 of 15 acc (40%) while p53 aberration was demonstrated in 11 of tumor (73.3%). there was a statistically significant difference between the expression of ki67 and p53 proteins in acc cases (p value = 0.041). pearson’s correlation test demonstrated a significant positive correlation between the numbers of percentage of ki67 and p53 positive cells in acc cases (r = 0.042). conclusions: this study suggests that ki67 positive actively proliferating cells and p53 aberrations may play a role in acc development and progression. keywords: adenoid cystic carcinoma, ki-67, p53. (j bagh coll dentistry 2013; 25(2):76-79). introduction carcinomas of the salivary glands are rare, comprising less than 0.5% of all malignancies and about 5% of head and neck cancers (1). they are characterized by morphological diversity between different tumor types or even within an individual tumor mass (2, 3). adenoid cystic carcinoma (acc) is a common salivary gland cancer subtype accounting for 22% of salivary gland malignancies and 1% of all head and neck cancers (4,5). perineural invasion, delayed onset of hematogenous metastasis and poor response to traditional chemotherapies are characteristics of this cancer (6,7). acc is histologically characterized by cribriform pattern. tubular and solid patterns are also recognized. acc is composed of epithelial and myoepithelial cells (7,8). acc was originally described by lorain and laboulbene in 1853. in 1859, billroth suggested the name cylindroma. in 1930, spies suggested the term adenoid cystic carcinoma to replace cylindroma and this name has been widely accepted. until 1940s, the tumor was thought to be a benign variant of the mixed salivary gland tumor. in 1943, dockerty and mayo emphasized the malignant nature of this tumor (9,10). ki67 is a nuclear protein that is encoded by the gene mki67 (11). this protein is associated with cell proliferation and is associated with transcription of ribosomal rna (12,13). the ki-67 is used as a marker for cell proliferation. during inter-phase, the ki-67 protein is found specifically in the cell nucleus, whereas in mitosis most of the protein is transported to the surface of the chromosomes. this protein is present in all active phases of the cell cycle (g2, s, g1 and mitosis) but is absent in resting cells (g0) (14,15). p53 is located at 17p 13.1, and it is altered in many types of cancer. the p53 protein stimulates the transcription of several genes that mediate cell cycle arrest, and this protein initiates apoptosis in response to dna damage. while the wild-type p53 protein makes tumor differentiation possible, the mutant p53 protein blocks it (16,17). mutation in the p53 gene, which results in encoded nonfunctional protein, is considered as the most common genetic event in human cancer. it has been suggested that mutated p53 may lead to carcinogenesis, as the wild-type p53 contributes to tumour suppression through at least two mechanisms in response to dna damage, arrest of cell proliferation and induction of apoptosis (18). it is important to note that some p53 mutations do not result in positive immunostaining. however, p53 protein accumulation can occur in the absence of underlying gene mutations (19) in response to cellular stress that can result in stabilization, accumulation and activation of p53 in the nucleus (20,21). aim of this study is to evaluate the immunohistochemical expression of ki67 and p53 proteins in acc cases. (1) assistant professor, department of oral diagnosis, collage of dentistry, university of baghdad. j bagh college dentistry vol. 25(2), june 2013 expression of ki67 and oral diagnosis 77 materials and methods sample collection a retrospective study was carried out on a fifteen of formalin fixed and paraffin embedded tissue blocks of adenoid cystic carcinoma of salivary gland origin, which were collected from different laboratories archives in baghdad (collage of dentistry, al – shaheed hospital and private centre). tissue preparation and staining protocol first, h and e stained sections were employed for confirmation of diagnosis. for immunohistochemical staining (ihc), sections with 5μ thickness were prepared, deparaffinised and rehydrated. antigen retrieval was performed for 30 minutes. internal peroxidase activity was inhibited by 3% h2o2. tissue sections were then incubated overnight with the anti-ki67 monoclonal antibody (mib-1, dako, denmark) and p53 (do 7, dako, denmark) at a 1/50 dilution separately. staining results and scoring system brown nuclear staining for ki-67 and p53 was considered as positive. immunoreactivity was expressed by determining the percentage of positive tumor cells, intensity of staining was not considered for evaluation. at least 1000 cells per case in ten high power fields were considered. the ki-67 and p53 nuclear expression in ≤5% of tumor cells was scored as negative, 6 – 25% (+), 26 – 50% (++), 51 -100% (+++). statistical analysis data were analyzed by spss (statistical package of social sciences) software for window 10. the percentage of variable was obtained by using chi – square test. the p ≤ 0.05 was considered statistically significant. pearson’s correlation test was used to verify any correlation between the percentage of positive cells of ki67 and p53 of acc cases. results sex of patients with acc included nine females (60%) and six males (40%) with mean age of 55.5 ± 15.4 years. the majority of the cases were located in minor salivary glands mainly the palate (46.7%), followed by floor of the mouth (20%), upper lip (13.3%), and one case in the maxilla (6.7%) and only two cases were from major salivary gland (submandibular gland). the histologic pattern of acc case was mainly cribriform pattern (figure 1a and b) with some exception in few areas showed tubular pattern. forty percent (40%) of acc cases expressed ki67 immunopositivity (figure 2). p53 immunopositivity was seen in 73.3% (figure 3), seven cases showed score (+) expression, p53 immunopositive cells tend to be evenly distributed within the tumor islands. in normal salivary gland tissue expressed positive ki67 while negative expression for p53 (figure 4 a and b respectively). there was a statistically significant difference between the expression of ki67 and p53 proteins in acc cases (p value = 0.041) (figure 5). pearson’s correlation test was also able to demonstrate significant positive correlation between the numbers of percentage of ki67 and p 53 positive cells in acc cases (r = 0.042). discussion adenoid cystic carcinoma is an uncommon form of malignant neoplasm that arises most commonly in the major and minor salivary glands of the head and neck. it is often slow to metastasize, but has a persistent and relentless growth with a poor long term prognosis. major and minor salivary glands including seromucinous glands are the frequent sites of occurrence. the histological picture is variable. in its classic form, the tumor is composed of small uniform cells arranged in cribriform, tubular or solid growth patterns with interspersed globules and cylinders of hyaline basement membrane material (5, 6, 9, 10). one of the most important biological mechanisms in oncogenesis is cell proliferation. ki-67 is essential for cell proliferation. ki-67 is required for the synthesis of ribosomes during the cell cycle. therefore it is relevant to the rate of protein synthesis. ki-67 was expressed at a rate of 40%. the difference in the expression of this marker in different studies may be related to the type of antibody used (monoclonal and polyclonal), and the differences in how the cells are counted. this relatively low expression ki-67 rate may explain the present study and due to a relatively small number of patients and measuring the expression by using immunohistochemical staining, which effected by its a semi-quantitative nature, tissue aging effects, the staining technique, the enzyme antibody used, and single observer bias. however in accordance with other reported, in all of revealed the frequency of ki67 expression in acc was lower and showed that this marker j bagh college dentistry vol. 25(2), june 2013 expression of ki67 and oral diagnosis 78 has a role in determining the short-term prognosis (5,7,11,12,14-16,18,22) . in this study, 73.3% of cases were p53 positive and seven cases of them showed low expression and this finding is similar to previous reports (7,14,16-19,20-22). this could be explained by the fact that in some tumors, for instance, p53 intronic mutations have been associated with stabilization of the p53 protein (21). on the other hand, p53 protein can accumulate in the absence of underlying gene mutations (18) in response to cellular stress that can result in stabilization, accumulation and activation of p53 in the nucleus. the exact role of this p53 protein accumulation in tumors has not been completely clarified. in conclusion; this study suggests that ki67 positive actively proliferating cells and p53 aberrations may play a role in acc development and progression. references 1. speight pm, barrett aw. salivary gland tumours. oral dis 2002; 8: 229–40. 2. barnes l, international academy of pathology, world health organization, international agency for research on cancer. pathology and genetics of head and neck tumours. lyon: iarc press; 2005. 3. schwarz s, ettl t, kleinsasser n, driemel o. loss of maspin expression is a negative prognostic factor in common salivary gland tumors. oral oncol 2008; 44, 563– 70. (ivsl). 4. jaso j, malhotra r. adenoid cystic carcinoma. arch pathol lab med 2011; 135: 511–515. 5. malhotra kb, agrawal v, pandey r. high grade transformation in adenoid cystic carcinoma of the parotid: report of a case with cytologic, histologic and immunohistochemical study. head and neck path 2009; 3: 310–314. 6. ashkavandi z, ashraf m, moshaverinia m. salivary gland tumors: a clinicopathologic study of 366 cases in southern iran. asian pacific j cancer prev 2013; 14: 27-30. 7. terada t. adenoid cystic carcinoma of the oral cavity: immunohistochemical study of four cases int j clin exp pathol 2013; 6: 932-938. 8. el-naggar ak, huvos ag. adenoid cystic carcinoma. in: barnes l, eveson jw, reichart p, sidransky d (eds). world health organization classification of tumours. pathology and genetics of head and neck tumours. lyon: iarc press; 2005. pp: 221-222. 9. ajila v, hegde s, gopakumar n, babu s. adenoid cystic carcinoma of the buccal mucosa: a case report and review of the literature. dent res j 2012; 9: 642 – 6. 10. mehta dn, parikhsj. adenoid cystic carcinoma of palate. j nat sci biol med 2013; 4: 249–252. 11. bullwinkel j, baron-lühr b, lüdemann a, wohlenberg c, gerdes j, scholzen t. ki-67 protein is associated with ribosomal rna transcription in quiescent and proliferating cells. j cell physiol 2006; 206: 624-35. 12. tadbir aa, pardis s, ashkavandi1 zj, najvani ad, ashraf mj, taheri a. expression of ki67 and cd105 as proliferation and angiogenesis markers in salivary gland tumors. asian pacific j cancer prev 2012; 13: 5155-59. 13. rahmanzadeh r, hüttmann g, gerdes j, scholzen t. chromophore-assisted light inactivation of pki-67 leads to inhibition of ribosomal rna synthesis. cell prolif 2007; 40: 422-3. 14. alves fa, pires fr, de almeida op, lopes ma, kowalski lp. pcna, ki-67 and p53 expressions in submandibular salivary gland tumors. int j oral maxillofac surg 2004; 33:593-597. 15. huang y, yu t, fu x, chen j, liu y, li c, xia y, zhang z, li l. egfr inhibition prevents in vitro tumor growth of salivary adenoid cystic carcinoma. bmc cell biology 2013; 14:13. (ivsl). 16. ko yh, roh sy, won hs, et al. prognostic significance of nuclear survivin expression in resected adenoid cystic carcinoma of the head and neck. head neck oncol 2010; 2: 30 17. barrera je, shroyer kr, said s, hoernig g, melrose r, greer ro. estrogen and progesterone receptor and p53 gene expression in adenoid cystic cancer. head and neck pathol 2008; 2:13–18 18. ben-izhak o, laster z, araidy s, nagler rm. tunel – an efficient prognosis predictor of salivary malignancies. british j cancer 2007: 96: 1101-1106. 19. kandel r, li sq, ozcelik h, rohan t. p 53 protein accumulation and mutations in normal and benign breast tissue. int j cancer 2000; 87: 73–78. 20. bode am, dong z. post-translational modification of p 53 in tumorigenesis. nat rev cancer 2004; 4: 793– 805. 21. gomes cc, diniz mg, orsine la, duarte ap, fonseca-silva t, et al. assessment of tp53 mutations in benign and malignant salivary gland neoplasms. plos one 2012; 7(7): e41261. 22. saghravania n, nooshin m, jafarzadeh h. comparison of immunohistochemical markers between adenoid cystic carcinoma and polymorphous low grade adenoma. j oral sci 2009; 51: 509-14. (ivsl). 23. tewari a, padma s, sundaram ps. detection of atypical metastases in recurrent adenoid cystic carcinoma of parotid gland. j can res ther 2013; 9: 148-50. j bagh college dentistry vol. 25(2), june 2013 expression of ki67 and oral diagnosis 79 a b figure 1.a adenoid cystic carcinoma, cribriform histological subtype and b. neural infiltration (invasion) in adenoid cystic carcinoma. original magnification 100x – h&e. figure 2. adenoid cystic carcinoma, cribriform histological subtype demonstrating nuclear immunostaining for ki67. original magnification 200x. figure 3. adenoid cystic carcinoma, cribriform histological subtype demonstrating nuclear immunostaining for p53. original magnification 200x figure 4a. normal salivary gland tissue demonstrating nuclear immunostaining for ki67. original magnification 200x. figure 4b. normal salivary gland tissue demonstrating negative staining for p53. original magnification 200x. figure 5. expression of ki67 and p53 in acc. ali.doc j bagh college dentistry vol. 27(1), march 2015 effect of systemic oral and maxillofacial surgery and periodontics 133 effect of systemic administration of simvastatin on dental implant stability: a random clinical study ali mohammed hassan, b.d.s. (1) adil al kayat, b.d.s., m.sc., f.d.s.r.c.s. (2) abstract background: the primary objective for many researches carried out in dental implantology was to reduce the period needed for functional implant loading, simvastatin (cholesterol lowering medication) had many pleiotropic effects, one of which was increasing bone density around titanium implants (1) and subsequently establishing faster osseointegrated dental implants (2,3). this study aims to reduce the period of time needed to establish secondary stability of dental implant measured in isq (implant stability quotient) by investigating the effect of orally administered simvastatin on bone. materials and methods: simvastatin tablets (40mg/day for three months) were administered orally for 11 healthy women aged (40-51) years old who received 15 dental implants (dentium, implantium) in the traumatic functional implant zone(4), this is the intervention group, the control group (n=11) received 14 dental implants in the same zone. 3 dental implants in 2 subjects were lost, leaving a total of 26 dental implants in 20 patients with 10 patients in each group. all subjects were radiographed with opg for preliminary assessment and with ct scan for registering bone density in hounsfield units. different dental implant sizes were used according to optimal patients' needs. an informed consent was obtained from the intervention group and the recommended monitoring protocol was followed. dental implant stability isq were recorded using rfa by osstelltm isq for both groups three times: immediately after implant placement (at surgery) and after 8,12 weeks respectively. results: results showed that the mean implant stability for the intervention group was significantly higher p= 0.01 after 12 weeks in comparison to that of the control group. simvastatin showed statistically significant effect on implant stability among the intervention group after 8 and 12 weeks (p value for both times <0.001) with the attributed risk percent was 70.8 and 50 respectively. conclusions: this study concluded that the intervention group had higher implant stability and was ready for functional loading prior to control group and that simvastatin might enhanced and/or accelerated the process of osseointegration. keywords: implant stability, simvastatin, resonance frequency analysis. (j bagh coll dentistry 2015; 27(1):133-137). introduction the dental implant is increasingly becoming a popular treatment for replacing missing teeth for partially dentated as well as edentulous patients. in 2011 alone, dentists across the u.s. placed over five million implants, according to the american dental association (5). osseointegration was first described by brånemark and co-workers (6) . the term was first defined in a paper by albrektsson et al 1981 as direct contact (at the light microscope level) between living bone and implant (7). since the histological definitions have some shortcomings, mainly that they have a limited clinical application, another more biomechanically oriented definition of osseointegration has been suggested: “a process whereby clinically asymptomatic rigid fixation of alloplastic materials is achieved, and maintained, in bone during functional loading” (8). over the following years attempts have been made by researchers to improve dental implant osseointegration (clinically applicable in terms of dental implants (1)master student, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2) assistant professor, chairman of the scientific council of oral and maxillofacial surgery, iraqi council of medical specialties. stability) through understanding the factors influencing it and the production of various materials in favor of that concept. one of these newly studied materials is simvastatin. simvastatin is a 3-hydroxy-3-methylglutarylcoenzyme a (hmg-coa) reductase inhibitor. it is widely used as a cholesterol-lowering drug and inhibits hepatic cholesterol biosynthesis. recent studies have shown a beneficial effect of statins on bone mineral density (bmd) (9,10) . it has been suggested that several statin drugs, including simvastatin, increase the mrna expression of bone morphogenetic protein (bmp-2) in osteoblasts, with a subsequent increase in bone formation. simvastatin has been shown to enhance osseointegration of pure titanium implants in osteoporotic rats (11). other experimental study shows that locally administered simvastatin was detrimental to the repair of defects in the calvaria of rats (12). the period required generally for an osseointegration to be achieved and for dental implant to be loaded is about 3-6 months which still represent a relatively long period for patients and any efforts focusing on reducing this period are entitled for consideration and scientific research which is the objective of this study. j bagh college dentistry vol. 27(1), march 2015 effect of systemic oral and maxillofacial surgery and periodontics 134 materials and methods this study was conducted at the dental implant unit in oral and maxillofacial department of college of dentistry, baghdad university, from january 2012 to february 2014, where twenty two healthy females aged (40-51) years old received 29 dental implants (dentium, implantium) were divided randomly (using alternating randomization method) into two groups, control and intervention group. 3 dental implants in 2 subjects were lost, leaving a total of 26 dental implants in 20 patients with 10 patients in each group: the intervention group , this group received 14 titanium screw type endosseous dental implants (dentium, implantium) in the traumatic functional implant zone (the area from maxillary right 1st premolar to the maxillary left 1st premolar) along with systemically administrated (oral) simvastatin 40mg/day (as an accepted dose for humans) (13) post-operatively for three months. the control group, this group received 12 titanium screw type endosseous dental implants (dentium, korea) in the traumatic functional implant zone and submitted to the same procedure of intervention group without the administration of post-operative simvastatin. exclusion criteria: a) smokers. b) alcoholics. c) patients with any chronic systemic disease. for example (active liver disease, patients on warfarin and/or antifungal medication and/or cyclosporine…etc.) d) pregnant or lactating females. e) patients with inadequate sub-antral distance, due to maxillary sinus neumatization (14). f) implant site subjected previously to supplemental surgical procedures (bone graft, ridge augmentation….etc.). the prospective implant sites were examined clinically and radiographically by two views: orthopantomogram (opg) and ct scan for registering bone density (using hounsfield units and according to misch classification of bone quality) (15) at the target site and also for precise placement of the dental implants through providing information about width of the alveolar bone and proximity to the maxillary sinus. after the patients signed an informed consent expressing their approval for participating in this study the insertion of fixtures is carried out in the traumatic zone for both groups then the primary stability is measured immediately after dental implant placement by a colleague for each patient by resonance frequency analysis (rfa) using osstelltm isq (goteborg, sweden) through inserting the smart peg into the implant and two readings of the isq (implant stability quotient) values are recorded; in bucco-palatal direction and the other in mesio-distal one. implant stability was measured again after 8 and 12 weeks postoperatively by the same colleague using rfa to compare its values (isqs) between both groups. group a were asked to perform a liver function test (sgpt, sgot) after 6 and 12 weeks postoperatively as a monitoring for any hepatic side effects and to report any muscular/joint pain, spasm or discomfort for further cpk (creatine phosphokinase) evaluation (16). results statistical analysis statistical analyses were done using spss version 21 computer software (statistical package for social sciences) in association with microsoft excel 2010. in this study the following statistics were used: 1. descriptive statistics: including; mean, standard deviation and standard error. 2. parametric statistical tests of significance: including; t-test, paired t-test and cohen’s d (standardized measure of effect size). the difference in mean stability between the two groups (table 1) shows a comparison of dental implant mean stability between both groups through time intervals, where in group a after 8 weeks of surgery there was an increase in the mean stability which was not statistically significant by 1.8 isq units compared to the primary stability readings. the changes observed during the 1st 8 weeks of surgery were evaluated as a weak effect (cohen’s d= 0.22). table 1: mean-isq of the 2 perpendicular directions at surgery and after 8 weeks at surgery after 8 weeks changes compared to baseline cohen’s d p (paired t-test) control n 12 12 12 mean 72.8 66 -6.7 -0.65 0.045 sd 8.2 6.3 10.3 se 2.36 1.81 2.97 intervention n 14 14 14 mean 73.5 75.3 1.8 0.22 0.44[ns] sd 7 6.6 8.3 se 1.87 1.78 2.21 j bagh college dentistry vol. 27(1), march 2015 effect of systemic oral and maxillofacial surgery and periodontics 135 at week 12 of surgery the mean isq increased from that of the 8th week by an average of 4.2 isq units. this positive effect was statistically significant and it was evaluated as a strong effect (cohen’s d= 1) (table 2). table2: mean-isq of the 2 perpendicular directions after 12 weeks and compared to primary stability after 12 weeks changes compared to baseline cohen’s d p (paired t-test) control n 12 12 mean 69.3 -3.5 -0.42 0.17[ns] sd 5 8.3 se 1.44 2.4 intervention n 14 14 mean 79.5 5.9 0.81 0.01 sd 3.9 7.3 se 1.05 1.96 the total change in mean isq after 12 weeks of the surgery compared to the primary stability was an average increase of 5.9 isq units which is statistically significant (p value = 0.01), and the effect evaluated as a strong effect (cohen’s d= 0.81). the whole behavior of implant stability for both groups is shown in (figure 1) figure 1: illustrating the mean stability of the dental implants for both control and intervention groups where the left (y) axis represent the isq units and the horizontal (x) axis represent the time measured in weeks. number of implants achieved 70+ isq in both groups the stability of implant at 70 isq or more is considered an implant with high isq stability (17), statistical test using attribute risk percent was used to compare numbers of dental implants in treated versus non treated control group that achieved the bench mark of implant stability (70+ isq) over time as illustrated in (figure 2) below. figure 2: number of implants achieved high stability in (figure 2) the control group and the intervention group show no difference at surgery but after 8 weeks 25% of the control group reached the high isq level while in the intervention group 85.7% achieved the high stability level of 70+ isq. at week 12, 50% of the control group dental implants reached to the bench mark level of high implant stability in comparison to the intervention group where 100% of the dental implants were at high implant stability (all the dental implants in the intervention achieved 70+ isq at the end of the study). discussion to the best of the authors' knowledge; this study is the first and no other comparable studies were available. the sample selection was based on two basic features: gender and age. females were selected over males because the changes in bone remodeling occur in a faster rhythm, and their age was 40+ years old and not younger because in this range of age most of bone parameters regarding bone regeneration capacity, elasticity, strength and even cell viability are declining especially in females aged above 40 years old, where 34% had osteopenia and 8% had osteoporosis (18). j bagh college dentistry vol. 27(1), march 2015 effect of systemic oral and maxillofacial surgery and periodontics 136 monitoring protocol was applied throughout this study to all intervention group, their liver function tests were negative and within the normal range (sgpt < 34 µ/l, sgot < 31 µ/l). members of the intervention group were asked routinely to report any muscular pain, cramps, and weakness. no such reports or complaints were informed. among the control group; the mean isq after 8 weeks of surgery showed an obvious reduction which re-increased to an obvious increment till 12 weeks. the overall change after 12 weeks compared to primary stability at surgery was still in the negative direction making the final stability still less than the primary one; yet they are loadable. this pattern is well documented in literature especially for mean primary stability of more than 70 isq giving the fact that the conventional 2-stage treatment loading protocol used a period of 3-6 months for osseointegration prior to loading (19,20). however, simvastatin treatment changed the pattern described earlier for the control group. the mean isq for the intervention group was obviously higher compared to primary stability (mean isq at surgery was 73.5 and at the 8th week was75.3), although the positive changes observed were less than the level of statistical significance; nevertheless, it contradicted the negative trend observed for isq in the first 8 weeks in untreated control group (mean isq at surgery was 72.8 and at the 8th week was 66). this positive trend in isq change in treatment group continued till the end of the study, making the stability after 12 weeks significantly and noticeably higher than that of primary stability. this finding is opposite to the negative loss in isq in relation to primary stability observed in control group within the scope and parameters of the current study. another advantage for effectiveness of simvastatin on dental implant stability was the absence of difference in mean isq at primary stability between the two groups (control 72.8 isq, intervention 73.5 isq, the difference was 0.7 isq), while after 8 and 12 weeks the intervention group had a significant advantage around 10 isq units increase in mean difference over the untreated control group (control group mean isq at week 8 and 12 was 66, 69.3 respectively while intervention group mean isq at week 8 and 12 was 75.3, 79.5 respectively). since these numbers represent the mean stability, it doesn't mean that each individual dental implant of the intervention group is necessarily ready for immediate loading. to summarize the current study outcome, it is worth mentioning that an almost comparable proportion of subjects had high primary stability (>70 isq) in both control (75%) and simvastatin treated group (71.4%). after 8 weeks of surgery the rate of high stability in the intervention group increased to (85.7%) while among those untreated (control group) only (25%) had high stability. after 12 weeks, all simvastatin treated group achieved the bench mark of implant stability (70+ isq) while only 50% of untreated group achieved this favorable outcome which they may reach it eventually on the expense of time. in conclusion, simvastatin administration had reduced the generally needed functional loading time in traumatic functional implant zone of dental implants from 3-6 months (12-26 weeks) to almost 2 months (8 weeks) by enhancing osseointegration of dental implant and increasing its stability faster than that in control group. simvastatin was well tolerated in all healthy subjects as they were submitted for periodic monitoring (liver function test) and all tests were normal and no subject reported muscular pain or weakness. further recommendation is to measure dental implant stability at shorter time intervals (after 7 weeks from primary stability) to detect earlier changes associated with the drug. inclusion of a larger sample for more conclusive results and a longer period of follow up to evaluate the long term effect on success rate of dental implants. references 1. du z, chen j, yan f, xiao y. effects of simvastatin on bone healing around titanium implants in osteoporotic rats. clinical oral implants research 2009; 20(2):145-50. 2. yang f, zhao sf, zhang f, he fm, yang gl. simvastatin-loaded porous implant surfaces stimulate preosteoblasts differentiation: an in vitro study. oral surgery, oral medicine oral pathol oral radiol endodontol 2001; 111(5): 551-556. 3. nyan m, hao j, miyahara t, noritake k, rodriguez r, kasugai s. accelerated and enhanced bone formation on novel simvastatin loaded porous titanium oxide surfaces. clinical implant dentistry and related research 2013. 4. tolstunov l. implant zones of the jaw: implant location and related success rate. j oral impl 2007; 33(4): 211-20. 5. http://www. american dental association.org.2014, january. 6. branemark p, hansson b, adell r, breine u, lindstrom j, hallan o, ohman a. osseointegrated implants in the treatment of the edentulous jaw. experience from a 10years period. scand j plast reconstr surg suppl 1977; 16: 1-132. 7. albrektsson t, brånemark pi, hansson ha, lundström i. osseointegrated titanium implants. requirements for ensuring a long-lasting, direct bonej bagh college dentistry vol. 27(1), march 2015 effect of systemic oral and maxillofacial surgery and periodontics 137 to-implant anchorage in man. acta orthop scand 1981; 52(2):155-70. 8. mantri, s, khan, z. prosthodontic rehabilitation of acquired maxillofacial defects. head and neck cancer. intech 2012. p.315-36. 9. klçcoglu ss, erdemli e. new addition to the statin’s effect. journal of trauma-injury, infection, and critical care 2007; 63(1): 187-191. 10. uzzan b, cohen r, nicolas p, cucherat m, perret gy. effects of statins on bone mineral density: a metaanalysis of clinical studies. bone 2007; 40(6): 1581-7. 11. du z, chen j, yan f, doan n, ivanovski s, xiao y. serum bone formation marker correlation with improved osseointegration in osteoporotic rats treated with simvastatin. clin oral imp res 2013; 24: 422-7. 12. calixto j, villaboim de castro lima c, frederico l, pio dos santos de castro lima r, anbinder a. the influence of local administration of simvastatin in calvarial bone healing in rats. journal of craniomaxillofacial surgery 2011; 39(3): 215-220. 13. park jb. the use of simvastatin in bone regeneration. med oral patho 2009; 14(9): 485-8. 14. calvo l, gómez-moreno g, lópez-marí l, ortiz-ruiz aj, guardia-muñoz j. atraumatic maxillary sinus elevation using threaded bone dilators for immediate implants. a three-year clinical study. med oral patol oral cir bucal 2010; 15(2): e366-70. 15. misch c. contemporary implant dentistry. 3rd ed. st louis, missouri: mosby, elsevier; 2008. p.137. 16. phillip o, james e, william g. handbook of clinical drug data. 10th ed. new york: mcgraw-hill publications; 2002. 17. sennerby l. 20 years of experience with the resonance frequency analysis. implantologie 2013; 21(1):21-33. 18. unni j, grag r, pawar r. bone mineral density in women above 40 years. j midlife health 2010; 1(1), 19-22. 19. atieh m, alsabeeha n, duncan w, silva r, cullinan m, schwass d, payne a. immediate single implant restorations in mandibular molar extraction sockets: a controlled clinical trial. clinical oral implants research 2013; 24(5): 484-96. 20. funato a, yamada m, ogawa t. success rate, healing time and implant stability of photofunctionalized dental implants. int j oral maxillofac imp 2013; 28: 1261-71. ali f.doc j bagh college dentistry vol. 25(2), june 2013 effects of time delay restorative dentistry 1 effects of time delay and tension system application after final flask closure on the vertical displacement of acrylic and porcelain teeth in maxillary complete dentures ali n.a. hussein, b.d.s., m.sc. (1) abstract background: the displacement of artificial teeth during complete denture construction presents major processing errors in the occlusal vertical dimension which were verified at the previous trial denture stage. the aim of this study was to assess the effect of delay in processing after final flask closure and tension application on the vertical acrylic and porcelain teeth displacement of complete dentures constructed from heat cured acrylic and the results were compared with the conventional processing method. materials and methods: forty samples of identical maxillary complete dentures were constructed from heat polymerized acrylic resin. these samples were subdivided into the following experimental subgroups in which each subgroup contains 5 samples for both acrylic and porcelain teeth and as follows: 1. conventional flasking technique and immediate processing. 2. conventional flasking technique and 6 hours delay in processing. 3. flasking technique with tension system and immediate processing. 4. flasking technique with tension system and 6 hours delay in processing. reference metal pins were attached to the middle of the buccal surface of the upper right canine and center of the buccal groove of the left first molar. and according to these reference points on the teeth another metallic reference pins were fixed on the denture vestibules and at a distance of 7.5mm by straight lines and 6.5mm where placed between the metal pins and the vestibules in order to standardize the measurement. the distance between the right and left metal pins on the canine and molars and the corresponding metal pins on the buccal vestibules were measured during the wax up stage and after processing by using an optical travelling microscope with an accuracy of 0.0005 mm. means in (mm) were analyzed statistically by analysis of variance and the comparative t-test and least significance test (lsd). results: significant reduction in vertical displacement of the teeth occurred in groups when 6 hours delay in processing were applied, but a significant improvement was also observed in groups with tension system application when compared with control group. on the other hand, there were a high significant reduction in the vertical displacement in groups with tension system and 6 hours delay in processing combination. while for the type of artificial teeth data showed significant difference in the amount of vertical displacement of the teeth in groups with acrylic teeth when compared with porcelain teeth. conclusions: the findings of this study showed that 6 hours delay in processing and tension system application were effective in reducing the vertical displacement of the artificial teeth during flasking. the maximum reduction in the displacement was observed in dentures constructed from acrylic teeth. on the other hand, significant decrease in vertical displacement of the teeth was detected in dentures constructed from porcelain teeth. key words: complete denture, flasking, tension system, vertical displacement, porcelain teeth, and optical travelling microscope. (j bagh coll dentistry 2013; 25(2):1-7). introduction accurate occlusal vertical dimension and stable occlusal scheme are very important criteria in order to obtain normal function. the artificial teeth displacement during complete denture flasking creates inharmonious occlusal configuration which were obtained during the previous trial denture stage.(1) its important from the clinical point of view to study the teeth movements during denture processing in order to obtain an accurate occlusal contact, retention, esthetics, health and functional quality of complete dentures.(2) the undesirable dimensional changes during processing are considered a major disadvantages of acrylic resin because these changes can modify tooth position.(3) (1) assist. lecturer, department of prosthodontics, college of dentistry, university of baghdad. the teeth displacement results in difficulties in occlusal adjustment procedure and leads to modifications in the planned vertical dimension and results in trauma and damages to the oral mucosa and loss of the alveolar bone.(4) the time delay after final flask closure whether 6,12 or 24 hours before placing in the water bath was an effective method for decreasing the teeth displacement.(5) but this procedure did not influence the dimensional change values of the denture bases.(6) methods of flask closure should be considered when the denture base stability and comfort of the patient are being assessed during clinical use of the dentures.(7) dimensional changes in the denture bases were reduced when these dentures were processed by using tension system to avoid flask opening during its transference from the hydraulic press. (8) accurate measurements of teeth displacement by using optical microscope is necessary in order to detect minor denture processing inaccuracies, j bagh college dentistry vol. 25(2), june 2013 effects of time delay restorative dentistry 2 which resulted in displacement of artificial teeth and responsible for poor retention and stability of the complete dentures and the increase in the vertical tooth displacement which results in difficulty in the occlusal adjustment procedures. (2) this study was conducted to evaluate and compare the effect of time delay in processing after final flask closure and tension system application on the vertical displacement of the artificial teeth (acrylic and porcelain) in maxillary complete dentures constructed from heat cured acrylic and comparing the results obtained with the conventional flasking technique and evaluate whether the type of artificial teeth influence the amount of that displacement. material and methods an edentulous silicone mold (columbia dentoform corp., new york, usa) was made from a metallic master die simulating an edentulous maxillary arch without irregularities in the alveolar ridge walls as shown in figure (1,a). forty similar stone casts were poured in type iii dental stone (elite model, zhermack technical, italy) in a w/p ratio of 30ml water to 100g powder. pouring was accomplished by using a vibrator (quayle dental, england) and the cast was left undisturbed for 45 min. then removed from the mold as illustrated in figure (1,b). (a) (b) figure 1: a. an edentulous silicone mold. b. stone cast used in the study. a standardized record bases were formed by the same technique for each stone cast with a 2mm-thick thermoplastic acrylic cakes (biocryl”c”, scheu-dental, iserlohn germany) by using biostar machine (schu-dental, germany) manipulated according to the manufacturer recommendations, an even thickness of 2mm for each record base was obtained and measured with a digital caliper (shanghai shenhanme assuring tools co., ltd, china), for standardization purposes, as shown in figure 2. figure 2: the stone cast with the thermoplastic record base attached to the biostar machine. after completion of record bases, a horse shoe shaped block of extra-hard wax (shanghai new century dental material, china) was attached to the record base to form the occlusion rim. the wax was contoured with a measurement of 22 mm length from the highest area of the labial flange to the occlusion edge and 18 mm in the posterior area. the width of the rim was about 3-4 mm anteriorly and (7-8) mm posteriorly (9) as illustrated in figure 3. figure 3: occlusion rim with record base and attached horse shoe wax. the maxillary stone casts were mounted on a semi adjustable articulator (model h2, hanau eng. co. buffalo, new york, usa) with an universal mounting technique. the condylar track was fixed at an average angle of 30 degree and the bennett angle was set at 10 degree. the incisal pin was secured to zero. the midline of the occlusal rim was oriented according to the incisal pin. to get the cast correctly seated in an anterio-posterior direction, the midline of the record base in the incisal region was placed at the tip of the triangle of bonwill. (10) in order to mount the maxillary cast with the wax rim. the interoclusal relation were set by using a standardized glass slab which had been mounted to the lower member of the articulator with plaster of paris half away between the upper and lower members of the articulator after the incisal pin was tightly secured at zero degree. this glass slab acted as an occlusal table upon j bagh college dentistry vol. 25(2), june 2013 effects of time delay restorative dentistry 3 which the maxillary cast with the occlusion rim was mounted. (11) the occlusal plane of the maxillary occlusal rim was oriented in the articulator with the aid of the marks on the condylar posts and the incisal pin, respectively. a dentate silicone mold (columbia dent form corp., new york, usa) was used as a standard guide for the arrangement of the artificial teeth in all dentures. the arrangement of the acrylic (florident, cross linked, shade no.3, china) and porcelain teeth (ivoclar vivadent, shade no.3, germany) started with the carved wax rim serving as a guide to the positions of the teeth inside the silicon mould as shown in figure 4. figure 4: the stone cast with the record base and artificial teeth were fixed to the semi adjustable articulator. metallic referential pins (unimetric 0.8 mm, dentsply-maillefer, swiss) of 8mm in length were fixed with instantaneous adhesive (cyanoacrylate adhesive material, japan) on the middle of the buccal surface of the upper right canine and buccal groove of the left first molar after drilling 3mm by using acrylic round bur for acrylic teeth and diamond bur for porcelain teeth. and according to these reference pins on the teeth another metallic reference pins were fixed on the denture vestibules by straight lines, keeping a 6.5mm distance between each screw and the upper border of the record base and 7.5mm between the reference pins on the teeth and that of the vestibules in order to have a standardized position for the right and left screws as shown in figure 5. the preprocessing vertical distances between the reference pins were measured with an stm microscope (leitz/wetzlar, germany) with an accuracy of 0.0005mm as shown in figure 6. the stone casts samples were subdivided into the following subgroups were each subgroup contains 5 samples for both acrylic and porcelain teeth and as follows: 1. conventional flasking technique and immediate processing (group1, control). 2. conventional flasking technique and 6 hours delay in processing (group2). 3. flasking technique with tension system and immediate processing (group3). 4. flasking technique with tension system and 6 hours delay in processing (group4). (a) (b) figure 5: a: the anterior reference point on the right canine. b: the posterior reference point on the left first molar. figure 6: the optical travelling microscope which was used for measuring the vertical distances. the stone cast and wax pattern with teeth sets were flasked in the lower part of conventional brass flasks (broden, sweden) with type ii dental stone (elite model, zhermack technical, italy). petroleum jelly (vaseline petroleum jelly, germany) was used as a separating medium. after 1 hour, the flasks were placed in boiling water to soften the wax base plate. the stone was cleaned with liquid detergent (alamadia, iraq) and boiling water solution, and two coats of sodium alginate (kamadent,swindon, england) were used as a mold separator. the proportion for mixing acrylic resin (regular tm, vertex-dental, netherlands) was used with a monomer: polymer ratio of 1:3 by volume. the resin was prepared in accordance with the manufacturer’s instructions and was carried out at once, in a clean and dry mixing j bagh college dentistry vol. 25(2), june 2013 effects of time delay restorative dentistry 4 vessel and mixed by a clean wax knife for 30 second. the mixture was then covered and left to stand until a dough stage was reached and then each sample was packed in accordance with the group assignments. a plastic sheet (amalgamated dental trade distributors ltd, london, england) was used as a separating medium during the initial flask closure under a pressure of 20 bars. after this procedure, the plastic sheet was removed and the acrylic resin excess trimmed away. in the conventional flask closure (groups 1 and 2), the flasks were placed in traditional clamps (ash co., england) after final pressing in a hydraulic press (bremer goldschlagerei wilh, herbst west germany) for 5 minutes. the flasks of group 1 were immediately immersed in water bath (ewl 55 01, west germany) at 73cº for 90 minutes, raising the temperature to 100ºc and maintaining the boiling for 30 minute, while the flasks of group 2 were submitted to the same procedures, however, the polymerization took place after 6 hours.(12) in the flask closure with tension system (groups 3 and 4), the same trial pack at final closure was accomplished; however, the flask was positioned between the 2 plates of the tension system(l). during the definitive flask closure, the screws of the lower plate were fitted into the holes of the upper plate and after hydraulic pressure; the screw-nuts were strongly tightened on the screws until just one stop as shown in figure 7. figure 7: the flasks were placed under the two plates of the tension system while they were still placed under the hydraulic press. flasks of the group 3 were immediately immersed in water bath at 73cº for 90 minutes, raising the temperature to 100ºc and maintaining the boiling for 30 minute, while the polymerization of the group 4 took place after 6 hours.(12) once the polymerization cycle was completed, the flasks were allowed to slow cooling in a water bath at room temperature before deflasking. the specimens were trimmed with a tungsten bur to remove acrylic flashes and finishes by using silicon carbide abrasive papers. pumice was used for final polishing. the specimens were immersed in water at 50ºc for 3 hours for excess residual monomer removal (13). the vertical distances in mm between the reference pins of the teeth and corresponding reference pins on the vestibules were measured in conditions similar to those used before denture polymerization by using optical microscope. the differences between pre and post polymerization measurements were calculated, organized and submitted to analysis of variance (anova), considering 2 factors (delay after final flask closure and tension system) and their interactions. differences between subgroups were submitted to comparative t-test and least significant testing (lsd at level of significance of 0.05). results the amount of the vertical displacements means of the artificial teeth in (mm) results were given in table 1. table 1: means and standard deviations for the data of vertical displacement of the artificial teeth. descriptive analysis experimental groups conventional flasking technique and immediate processing (control) conventional flasking technique and 6 hours delay in processing flasking technique with tension system and immediate processing flasking technique with tension system and 6 hours delay in processing artificial teeth measuring distances right canine left 1st molar right canine left 1st molar right canine left 1st molar right canine left 1st molar acrylic teeth mean 1.30 1.482 1.10 1.298 0.876 1.10 0.504 0.704 sd 0.015 0.047 0.015 0.014 0.011 0.015 0.011 0.011 porcelain teeth mean 3.104 3.312 2.704 2.906 2.506 2.612 1.88 2.066 sd 0.011 0.013 0.011 0.008 0.008 0.013 0.015 0.011 the experimental groups: 1. conventional flasking technique and 6 hours delay in processing: the results of this study indicated that conventional flasking technique and 6 hours delay in processing is effective in reducing the amount of vertical displacement of the artificial teeth and this was illustrated in table 2. 2. flasking technique with tension system and immediate processing: the results indicated that flasking technique with tension system and immediate processing is effective in reducing the amount of vertical displacement of the artificial teeth. and this was illustrated in table 3. j bagh college dentistry vol. 25(2), june 2013 effects of time delay restorative dentistry 5 table 2: t-test between control and experimental groups for conventional flasking technique and 6 hours delay in processing for acrylic and porcelain teeth (group2). groups t-test p-value sig control& group2 ( acrylic teeth) right canines 14.14 0.000 hs control& group2 ( acrylic teeth) left 1st molars 10.191 0.000 hs control& group2 (porcelain teeth) right canine 73.03 0.000 hs control& group2 (porcelain teeth) left 1st molars 79.62 0.000 hs table 3: t-test between control and experimental groups of flasking technique with tension system and immediate processing for acrylic and porcelain teeth (group3). 3. flasking technique with tension system and 6 hours delay in processing: the results indicated that flasking with 6 hours delay in processing and tension system is the best method in reducing the amount of vertical displacement of the artificial teeth and this were illustrated in table 4. the vertical tooth movements occurred in all measuring points; and the data showed high significant difference. however, movements were greater in the posterior region (1st molar region) when compared with the anterior region (canine region) for the control and time delay and tension system and combination of both as shown in table 5. the analysis of variance (anova) table shows that there were significant difference between the tested groups for the different processing times (immediate and 6 hours delay) and for flasking technique (conventional flask closure and tension system) were used as shown table 6 for acrylic teeth and table 7 for porcelain teeth. on the other hand the results indicated that significant reduction in the mount of vertical displacement for experimental groups with acrylic teeth when compared with same groups with porcelain teeth as shown in table 8; and figure 8 in the canine region and figure 9 in the first molar region. table 4: t-test between control and experimental groups for flasking technique with tension system and 6 hours delay in processing for acrylic and porcelain teeth (group4). groups t-test p-value sig control& group4 ( acrylic teeth) right canine 77.31 0.000 hs control& group4 ( acrylic teeth) left 1st molars 37.34 0.000 hs control& group4 (porcelain teeth) right canine 20.40 0.000 hs control& group4 (porcelain teeth) left 1st molars 31.1 0.000 hs table 5: t test between canine region and 1st molar region for the control groups and experimental groups for acrylic and porcelain teeth. groups t-test p-value sig right canines & left 1st molars of acrylic teeth in control group 6.906 0.002 hs right canines & left 1st molars of acrylic teeth in group2 99.00 0.000 hs right canines & left 1st molars of porcelain teeth in control group 24.18 0.000 hs right canines & left 1st molars of porcelain teeth in group2 27.48 0.000 hs right canines & left 1st molars of acrylic teeth group3 43.93 0.000 hs right canines & left 1st molars of porcelain teeth group3 12.139 0.000 hs right canines & left 1st molars of acrylic teeth group4 63.24 0.000 hs right canines & left 1st molars of porcelain teeth group4 22.89 0.000 hs table 6: anova table for comparison of control, delay in processing, tension system and combination of both for acrylic teeth in both measuring areas. measuring areas f-test p-value sig right canine 23.82 0.000 hs left 1st molars 74.25 0.000 hs right canines & left 1st molars 113.9 0.001 hs table 7: anova table for comparison of control, delay in processing, tension system and combination of both for porcelain teeth in both measuring areas. measuring areas f-test p-value sig right canine 109.2 0.000 hs left 1st molars 189.1 0.000 hs right canines & left 1st molars 83.16 0.000 hs *p<0.05 significant **p>0.05 non significant ***p<0.001 high significant. groups t-test p-value sig control& group3( acrylic teeth) right canine 106.6 0.000 hs control& group3( acrylic teeth) left 1stmolars 14.197 0.000 hs control&group3(porcelain teeth) right canine 90.15 0.000 hs control& group3(porcelain teeth) left 1st molars 110.68 0.000 hs j bagh college dentistry vol. 25(2), june 2013 effects of time delay restorative dentistry 6 table 8: lsd test for comparison of the control groups and experimental subgroups for the type of artificial teeth (acrylic and porcelain). groups right canine left 1st molar t test pvalue sig t test pvalue sig group1 (control) 194.5 0.001 hs 78.03 0.001 hs group2 ( time delay) 40.11 0.001 hs 21.88 0.001 hs group3 (tension system) 124.5 0.001 hs 155.95 0.001 hs group4 (combination of time delay and tension system) 202.8 0.001 hs 133.5 0.001 hs *p<0.05 significant **p>0.05 non significant ***p<0.001 high significant. figure 8: bar chart of the comparison of means in mm between acrylic and porcelain teeth in the canine region. figure 9: bar chart of the comparison of means in mm between acrylic and porcelain teeth in the first molar region. discussion the delay in processing by a period of time (6-hours) found to be effective in increasing resin dough relaxation, and probably a possible laboratory technique to be used in the laboratory steps for denture processing. the explanation for leaving the flask to stay for several hours before processing is to allow the resin dough mass to flow into all regions of the mold. in this study, 6hours delay time produced statistically significant reduction in the vertical tooth displacement in relation to the flask closure methods used, when compared to the immediate processing time due to resin mass stay for a longer time before polymerization.(14,15) the flask closure with tension system method positively influenced the tooth displacements independently of the post-pressing time used. this system reduced the stress release because flask closure was maintained after press releasing, promoting less distortion in the denture base. therefore, the reduction of the base inaccuracy allowed the teeth to preserve their position in the denture.(16,17) reduced dimensional changes in the denture bases processed with tension system suggest that this system maintained the acrylic resin dough under constant pressure conditions, because the halves of the flasks remained in contact when it was removed from the hydraulic press. this condition may impede or inhibit the premature release of the residual internal stresses from the acrylic resin dough before polymerization.(8) so the combinations of the two methods were found to be beneficial for reducing the vertical displacement of artificial teeth. a greater magnitude of tooth movement occurs in posterior teeth, altering the occlusal relationship. a possible explanation is that the exothermic setting reaction of the investing stone in contact with the wax trial denture causes softening and expansion of the wax leading to a change in tooth master cast relationship.(18, 19) and as the posterior teeth has a wider wax band than the anterior teeth so the amount of inaccuracies were also greater posteriorly.(20, 21) so the anterior teeth are located in a restrictive topographic area resulting from cast anatomy which impedes resin expansion. in addition, the topographic form of the anterior arch limits the stresses released after mould separation. the posterior region is less restrictive and permits strain release, producing more evident distortion in this region. (8, 22) teeth displacement were found to be smaller when acrylic teeth where used compared with porcelain teeth. the possible explanation for these finding is that the coefficient of thermal expansion of the acrylic teeth and denture base was the same, while for the porcelain teeth the coefficient is different from that of acrylic denture base.(23) this mismatch between porcelain coefficient and acrylic coefficient is responsible for the higher degree of porcelain teeth displacement. (24) j bagh college dentistry vol. 25(2), june 2013 effects of time delay restorative dentistry 7 the results of this study suggest that the delay in denture processing reduces the amount of teeth displacement. also tension system application should be a factor in decreasing the magnitude of vertical teeth displacement. on the other hand, the combination effect of delay in processing and tension system was found to be the method of choice in order to improve the stability and accurate position of the artificial teeth in the complete dentures. references 1. jackson ad, lang br, wong rf. the influence of teeth on the denture base processing accuracy. int j prosthod 1993; 6: 333-40. 2. barbosa cmr, fraga ma and goncalves tm. acrylic resin water sorption under different pressure, temperature, time conditions. mat res 2001; 4(1): 16. 3. vallittu pk, ruyer ie, buykuilmaz s. effect of polymerization temperature and time on the residual monomer content of denture base polymers. eur j oral sci 1996; 106(1): 588-93. 4. ono t, kila s, nakabi t. dimensional accuracy of acrylic resin maxillary denture base polymerized by a new injection pressing method. dent mater j 2004; 23(3): 348-52. 5. abd shukor ss, juszczyk as, clark rkf, radford dr. the effect of cyclic drying on dimensional changes of acrylic resin maxillary complete dentures. j oral rehab 2006; 33: 654. 6. consani rlx, mesquita mf, sobrinho lc, sinhoreti mac. dimensional accuracy of upper complete denture bases: the effect of metallic flask closure methods. gerodontology 2009; 26(1): 58-64. 7. consani rlx, domitti ss, mesquita mf, consani s. effect of packing types on the dimensional accuracy of denture base resin cured by conventional cycle in relation to post-pressing times. braz dent j 2004; 15(1): 63-7. 8. consani rlx, domitti ss, consani s. effect of a new tension system used in acrylic resin flasking, on the dimensional stability of denture bases. j prosthet dent 2002; 88(3): 285-9. 9. levin b, richardson gd. complete denture prosthodontics. a manual for clinical procedures. 17th ed. 2002. p. 54-5. 10. carlsson ge and magnusson t. management of temporomandibular disorders in the general dental practice. quintessence publishing co, inc1999. p 113. 11. bayraktar g, guvener b, bural c, uresin y. the influence of polymerization method, curing process, and length of time of storage in water on the residual methyl methacrylate content in dental acrylic resins. j oral rehabil 2005; 33: 115-20. 12. reeson mg, jepson nja. achieving an even thickness in heat polymerized acrylic resin denture bases for complete dentures. j prosthet dent 1999; 82(3): 359-61. 13. wagner a, negreiros i, rafael lx, consani i, marcelo f, mesquita i, mario ac, sinhoreti and faria ir. effect of flask closure method and postpressing time on the displacement of maxillary denture teeth. the open dentistry j 2009; 3: 21-5. 14. sykora o, sutow ej. posterior palatal seal adaptation: influence of high expansion stone. j oral rehab 1996; 23(5): 342-5. 15. boscato n, consani rlx, consani s, cury aadb. effect of investment material and water immersion time on tooth movement in complete denture. eur j prosthodont rest dent 2003; 13(4): 164-9. 16. bartoloni ja, murchison df, wofford dt, sarker nk. degree of conversion in denture base materials for varied polymerization techniques. j oral rehabil 2000; 27(6): 488-93. 17. duymus zy, yanikoglu nd. influence of a thickness and processing method on the linear dimensional change and water sorption of denture base resin. dent mater j 2004; 23(1): 8-13. 18. yau wef, chang yy, clark rkf, chow tw. pressure and temperature changes in heat cured acrylic resin during processing. dent mater 2002; 18: 622-9. 19. consani rlx, domitti ss, mesquita mf, consani s. influence of flask closure and flask cooling methods on tooth movement in maxillary dentures. j prosthodont 2006; 15(4): 229-34. 20. keenan pl, radford dr, clark rk. dimensional change in complete dentures fabricated by injection molding and microwave processing. j prosthet dent 2003; 89(1): 37-44. 21. kobayashi n, komiyama o, kimoto s, kawara m. reduction of shrinkage on heat activated acrylic denture base resin obtaining gradual cooling after processing. j oral rehab 2004; 31(7): 710. (ivls). 22. anusavice kj. phillips’ science of dental materials. 11th ed. 2008. pp.143-166. 23. kawara m, komiyama o, kimoto s, kobayashi n, nemoto k. distortion behavior of heat-activated acrylic denture-base resin in conventional and long, low-temperature processing methods. j dent res 1998; 77(6):1446-53. (ivls). 24. laughlin a, david eick j, alan g, leslie young, dorsey j. a comparison of palatal adaptation in acrylic resin denture bases using conventional and anchored polymerization techniques. j prosthodont 2001; 10(4): 204-211. (ivls). nawar.doc j bagh college dentistry vol. 26(4), december 2014 mesio-distal crown pedodontics, orthodontics and preventive dentistry180 mesio-distal crown dimension of permanent dentition in normal, crowding, and spacing of young adult sample aged 18-25 years nawar a. gburi, b.d.s. (1) dhiaa j. al-dabagh, b.d.s., m.sc. (2) abstract background: this study aimed to assess the effect of tooth width in malocclusion in relation to normal, crowding, and spacing dentition. materials and methods: the sample included dental casts of some dental students and orthodontic patients; their age was (18-25) years and having three groups normal, crowding, and spacing dentition groups. the sample was equally divided to three groups normal, crowding, and spacing dentition groups, each group contained 50 maxillary and 50 mandibular casts that were further subdivided by gender; all the stone casts were measured by highly sensitive digital vernier. results and conclusions: non-significant side difference was found in both dental arches in the three studied groups. males had higher mesiodistal crown dimension than females in all three groups, with significant gender difference in crowding and normal dentition groups. the mesiodistal distance of the segment measurements (total anterior material; total posterior material and total teeth material) were larger in crowded dentition then followed by normal and spaced dentition groups respectively in both gender. total anterior material in both arches had direct significant correlation with crowding malocclusion, while maxillary total anterior material had indirect significant correlation with spacing malocclusion. keywords: mesiodistal crown dimension, segment measurements, normal dentition, crowding dentition, spacing dentition. (j bagh coll dentistry 2014; 26(4):180-186). الخالصة متباعدة، والذي تم عن طریق فحص مرضى تقویم األسنان الذین حضروا قسم تقویم ،الطبیعیة، والباالسنان المزدحمة ھو تقییم تأثیر عرض األسنان فیما یتعلق : الھدف من الدراسة . سنة) 25-18(و كانت اعمارھم ,جامعة بغداد/ األسنان في كلیة طب األسنان، و طالب كلیة طب األسنان و , للفك السفلي 50قالب سني للفك العلوي و 50متباعدة، كل مجموعة تحتوي على تم تقسیم العینة بالتساوي إلى ثالث مجامیع المزدحمة، الطبیعیة، ومجموعة األسنان ال: اداة البحث . كذلك تم تقسیمھا حسب الجنس ؛ وقد تم قیاس كل القوالب السنیة باستخدام المقیاس السني الرقمي وھو حساس للغایة الذكور عموما كانوا . سر على حد سواء ألقواس األسنان في المجموعات الثالث التي شملتھا الدراسةتم العثور على فرق غیر ذا داللة إحصائیة بین الجانب األیمن واألی: الستنتاجا بعد اإلنسي الوحشي ال.لطبیعیة والمزدحمةیمتلكون اكبر بعد في التاج اإلنسي الوحشي لألسنان من اإلناث في جمیع الفئات الثالث، مع فارق كبیر بین الجنسین في مجموعة االسنان ا كانت أكبر بشكل موحد في مجموعة االسنان المزدحمة ثم تلیھا ) إجمالي مواد االسنان األمامیة؛ إجمالي مواد االسنان الخلفیة وإجمالي مواد األسنان(قیاسات المجزأة للقوس السني لل میة في كل من األقواس السنیة لھا ارتباط كبیر و مباشر مع مقدار التناقض في حجم كان إجمالي مواد االسنان األما. مجموعة األسنان الطبیعیة والمتباعدة على التوالي في كال الجنسین ناقض في حجم األسنان في مجموعة االسنان األسنان في مجموعة االسنان المزدحمة، في حین الفك العلوي كان إجمالي مواد االسنان األمامیة لھا ارتباط كبیروغیرمباشر مع مقدار الت .المتباعدة فقط introduction nance (1) described dental crowding as the difference between the spacing needed in the dental arch and the space available in that arch. also, the dental arches of a considerable number of individuals show spaces between some, or even all of the teeth, such dental arches are known as spaceddentition (2,3). thus, crowding or spacing can be described as an expression of an altered tooth/tissue ratio of as a dentoalveolar disproportion. tooth size in relation to the mandibular and maxillary arches determines whether the dentition is spaced or crowded, and discrepancies in the sizes of teeth in different arches determine buccal inter-digitation, overjet, overbite, and center line discrepancies (4,5). correspondingly, genetic factors may influence variation in space anomalies among different ethnic groups.the factors that associatedwith variability in space anomalies prevalence are gender (6), heredity and environment (7) and location, i.e. maxillary or mandibular arch (8). (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) assistant professor. department of orthodontics, college of dentistry, university of baghdad. crowding and spacing are considered as the most common manifestations of malocclusion and can occur as a result of either a shortage of the space required for tooth alignment or an excess of available space. hence, tooth size and arch perimeter should generally correspond in cases of acceptable arch alignment (9). this study aimed to compare the mesio-distal crown dimension of the teeth for both arches in both sides and for both gender in normal, crowded and spaced permanent dentition groups and to find out the correlation between mesio-distal crown dimension of the teeth with crowding and spacing malocclusion. materials and methods sample the sample included dental casts ofstudents of college of dentistry/baghdad universityand orthodontic patients who attended orthodontic department in college of dentistry/baghdad university.the sample was equally divided to three groups normal, crowding, and spacing dentition groups j bagh college dentistry vol. 26(4), december 2014 mesio-distal crown pedodontics, orthodontics and preventive dentistry181 selection criteria all subjects were iraqi arab in origin with an age (18-25) years, all of their permanent teeth must present except wisdom teeth. exclusion criteria the following subjects were excluded: 1. bimaxillary protrusion malocclusion; 2. history of orthodontic treatment or interproximal stripping performed prior to impression taken; 3. coronal carious lesion, restoration, crowns and/or onlays that affect mesio-distal dimensions of the teeth. 4. clinical sign of attrition; broken tooth; 5. pathological periodontal problems according to the gingival index and calculus deposition; 6. congenital dental defects such as deformed or supernumerary teeth; 7. bad habits; congenital deformity (cleft lip and palate). the sample was divided into: • 1st group (normal arches): this group included 50 cases (24 males and 26 females) with a space discrepancy (crowding or spacing) of less than 2 mm (12), bilateral cl i molars relationship (17), and bilateral cl i canines relationship (18), normal overjet and overbite (2-4 mm) (19). no evident rotation of teeth. • 2nd group (crowded arches): this group included 50 cases (26 males and 24 females), with a space deficiency of 2 mm or more (12). • 3rd group (spaced arches): this group included 50 cases (22 males and 28 females), with a space excess of 2 mm or more (12). method clinical examination each examined subject seated on the dental chair in an upright position, then clinically examined (extra-orally and intra-orally) to check his/her fulfillment of the required sample selection criteria, and if the examined subject was chosen to be included in the sample, his/her name, age and gender were recorded in a specific case sheet. dental cast production alginate hydrocolloid impression material was mixed with water according to manufacture instruction, after that, upper and lower impressions were taken for every subject of the samples from each group, and then the impression was poured immediately with dental rock die stone. before the final setting of the dental stone, the cast base was prepared. the base was labeled for name and number recording to be ready for the measuring procedure. cast measurements after completion of the cast production, the following measurements were done: a. space required mesiodistal crown dimension in millimeters of all maxillary and mandibular teeth except 1st, 2nd, and 3rd permanent molar was measured. the anatomic mesial and distal contact points of each tooth were marked by a fine marker on the dental cast and then the greatest mdcd was measured by sharp ends of digital vernier. the largest mesiodistal widths of the teeth are obtained by measuringthe distance between the anatomically correct contactpoints of each tooth mesial to the first molars. thedigital vernier was usually positioned buccal tothe teeth and parallel to the occlusal plane (the instrument held at right angle to the long axis of the crown). the measuring device may need tobe positioned occlusal to a rotated tooth (20, 21). each pair of study casts required 20 measurements which were all recorded on the subject’s case sheets. b. space available arch length measurement was obtained by digital vernier. the tips of measuring instrument are placed in the alveolar ridge from the points where the teeth are expected to contact one another in ideal alignment. only the arch length mesial to first permanent molar was measured. the measurement was done by dividing the arch into six segments (right and left)(21): 1. the anterior segments extend from a point between the central incisors to the point mesial to the canines. 2. the arch length around the canine. 3. the posterior parts of arch were measured from distal of canine to the mesial of the first permanent molar. grouping of the casts the grouping of the castswill be done on the basis of space analysis (tooth size-arch lengthdiscrepancy) into (12): 1. the normal arches: those with a space discrepancy of less than 2 mm and other normal occlusion features. 2. the crowded arches: those with a spacediscrepancy (space deficiency) of ≥ (-2 mm). 3. the spaced arches: thosewith a space discrepancy (space excess) of ≥ (+2 mm). space discrepancy should be coinciding for both arches in each group. j bagh college dentistry vol. 26(4), december 2014 mesio-distal crown pedodontics, orthodontics and preventive dentistry182 the measuring data the measuring data from the selected casts were computed into two waysfor the purpose of statistical analysis: i. segment measurements as: a) total anterior material (tam): cumulative mdcd of the four incisors in each arch. b) total posterior material (tpm): cumulative mdcd of the both canines and the four premolars in each side for each arch. c) total teeth material (ttm): cumulative mdcd of tam and tpm materials in each arch. ii. individual teeth measurements: mdcd of each tooth separately in each arch for all groups. statistical analysis all the data of the sample were subjected to computerized statistical analysis using spss computer program (version 19). the statistical analysis includes: 1descriptive statistics: including means, standard deviation (sd), statistical tables and figures. 2inferential statistics: including paired t-test: for intra-examiner and inter-examiner calibration and for side comparison, independent sample ttest: for the gender difference, anova test: for the comparison among the three groups, lsd test: for pair comparisons when anova test was significant and person’s correlation coefficient: for establish correlation of space discrepancy with mean values of segment measurements in each group. in the statistical evaluation, the following levels of significance are used: ns: non-significant, p > 0.05 s: significant, 0.05 ≥ p > 0.01 hs: highly significant p ≤ 0.01 results and discussion side difference the measured mean values of mdcd of individual teeth, in both arches showed no significant difference (p-value > 0.05)between right and left side by using paired ttest in all three groups of the sample, therefore, the mean of both sides of each individual tooth can be taken in the present study, and the degree of freedom was (d.f) = 49. however, the cause of this side similarity was attributed to a fact that, same factors on the same individual that affects the tooth size like genetic, nutrition, hormonal disturbances will affect its antimer (27). this is similar to previous findings (24,25) who found that, there were no differences between the right and left sides, in the permanent dentition. gender difference i. segment measurements: by using independent t-test, there was no significant difference (p > 0.05) between males and females regarding m-d distances of all segment measurements (tam, tpm, ttm) of spacing dentition group in both arches and the degree of freedom was (d.f) = 48. however, regarding normal dentition group, the degree of freedom was (d.f) =48; while maxillary tam (p-value = 0.03; t-test =2.242), mandibular tpm (p-value = 0.002; t-test =3.199) and ttm (p-value = 0.004; t-test =3.015) had significant difference between males and females. regarding crowding dentition group the degree of freedom was (d.f) =48; while maxillary tpm (p-value =0.037; t-test =2.151) and ttm (p-value =0.046; t-test =2.052)had significant difference between males and females. ii. mdcd of individual teeth: there were varying degree of significance and nonsignificance in all three measured groups of the sample between males and females in both arches by using independent t-test as shown in table (1). comparison among the mdcd of the segment measurements the mean values of segment measurements in both arches and in both gender were higher in crowding dentition group then followed by normal and spacing dentition group respectively, with high significant difference (p-value = 0.000) as indicated by anova test among the three group as shown in table (2); while lsd test as shown in the table (3). the present finding partially agreed with previous findings (22,23) who found crowded arches had significantly larger teeth than those with no crowding. furthermore, these findings partially agreed with previous studies (22, 14) who found the ttm in both arches and mandibular tam was significantly smaller in spaced dentition when compared with normal dentition. also, the present results were in agreement with previous findings (22,23) who found crowded group had significantly larger segment measurements than spaced group. the large mdcd of crowding dentition when compared with normal dentition group was attributed to environmental factors as the dietary consistency, the ‘‘toughness’’ of the diet and how much it exercises the muscles and stimulates the jaw growth (13,27). j bagh college dentistry vol. 26(4), december 2014 mesio-distal crown pedodontics, orthodontics and preventive dentistry183 table 1: descriptive statistics and genders difference of the mdcd of the individual teeth (mm) arch teeth descriptive statistics genders difference (d.f.=98) males females mean s.d. mean s.d. t-test p-value n or m al maxillary i1 8.78 0.52 8.47 0.48 3.05 0.003 (hs) i2 6.88 0.59 6.62 0.5 2.36 0.02 (s) c 7.89 0.52 7.7 0.51 1.81 0.073 (ns) p1 6.9 0.4 6.92 0.33 -0.28 0.784(ns) p2 6.66 0.41 6.6 0.4 0.73 0.466 (ns) mandibular i1 5.48 0.37 5.37 0.27 1.67 0.099 (ns) i2 6.03 0.43 5.79 0.36 3.08 0.003 (hs) c 7 0.49 6.58 0.41 4.64 0.000 (hs) p1 7.14 0.4 6.89 0.39 3.17 0.002 (hs) p2 7.18 0.5 6.88 0.4 3.37 0.001 (hs) c ro w di ng maxillary i1 9.3 0.53 8.99 0.57 2.8 0.006 (hs) i2 7.24 0.81 7.15 0.43 0.65 0.517 (ns) c 8.21 0.54 7.95 0.42 2.68 0.009 (hs) p1 7.38 0.44 7.21 0.47 1.88 0.063 (ns) p2 7.02 0.46 6.79 0.46 2.44 0.016 (s) mandibular i1 5.82 0.32 5.71 0.3 1.69 0.094 (ns) i2 6.44 0.38 6.32 0.39 1.46 0.147 (ns) c 7.32 0.41 6.89 0.38 5.43 0.000(hs) p1 7.43 0.43 7.5 0.46 -0.78 0.436 (ns) p2 7.68 0.57 7.66 0.51 0.24 0.814 (ns) sp ac in g maxillary i1 8.44 0.47 8.27 0.51 1.75 0.084 (ns) i2 6.49 0.51 6.54 0.51 -0.42 0.678 (ns) c 7.76 0.37 7.46 0.49 3.31 0.001 (hs) p1 6.78 0.48 6.85 0.43 -0.82 0.414 (ns) p2 6.53 0.51 6.63 0.43 -1.07 0.289 (ns) mandibular i1 5.27 0.33 5.31 0.32 -0.69 0.494 (ns) i2 5.72 0.35 5.83 0.53 -1.15 0.252 (ns) c 6.82 0.38 6.57 0.47 2.89 0.005 (hs) p1 6.86 0.41 6.83 0.4 0.37 0.715 (ns) p2 6.94 0.48 7.02 0.46 -0.86 0.39 (ns) table 2: comparison among segment measurements (mm) genders arch measurements descriptive statistics comparison crowding normal spacing d.f. =71 mean s.d. mean s.d. mean s.d. f-test p-value males maxillary tam 33.08 1.98 31.31 1.94 29.88 1.7 17.476 0.000 (hs) tpm 45.22 2.19 42.9 1.95 42.13 2.17 14.276 0.000 (hs) ttm 78.3 3.71 74.21 3.52 72 3.66 18.79 0.000 (hs) mandibular tam 24.5 1.24 23.03 1.39 21.98 1.16 24.021 0.000 (hs) tpm 44.86 2.11 42.64 2.47 41.24 2.05 16.389 0.000 (hs) ttm 69.36 2.99 65.68 3.57 63.22 2.99 22.652 0.000 (hs) females maxillary tam 32.29 1.76 30.19 1.6 29.62 1.71 17.555 0.000 (hs) tpm 43.91 2.11 42.45 1.95 41.89 2.21 6.302 0.003 (hs) ttm 76.2 3.5 72.63 3.21 71.5 3.66 12.667 0.000 (hs) mandibular tam 24.07 1.08 22.33 1.14 22.28 1.32 18.223 0.000 (hs) tpm 44.09 2.26 40.7 1.79 40.83 2.03 22.258 0.000 (hs) ttm 68.16 2.98 63.04 2.57 63.12 3.05 25.84 0.000 (hs) j bagh college dentistry vol. 26(4), december 2014 mesio-distal crown pedodontics, orthodontics and preventive dentistry184 table 3: lsd test for segment measurements (mm). gender arch measurements groups mean difference p-value m al es m ax ill ar y tam crowding normal 1.77 0.001 (hs) spacing 3.2 0.000 (hs) normal spacing 1.43 0.012 (s) tpm crowding normal 2.32 0.000 (hs) spacing 3.09 0.000 (hs) normal spacing 0.77 0.218 (ns) ttm crowding normal 4.09 0.000 (hs) spacing 6.3 0.000 (hs) normal spacing 2.21 0.043 (s) m an di bu la r tam crowding normal 1.47 0.000 (hs) spacing 2.52 0.000 (hs) normal spacing 1.05 0.006 (hs) tpm crowding normal 2.22 0.001 (hs) spacing 3.62 0.000 (hs) normal spacing 1.41 0.035 (s) ttm crowding normal 3.69 0.000 (hs) spacing 6.15 0.000 (hs) normal spacing 2.46 0.011 (s) f em al es m ax ill ar y tam crowding normal 2.11 0.000 (hs) spacing 2.68 0.000 (hs) normal spacing 0.57 0.220 (ns) tpm crowding normal 1.46 0.016 (s) spacing 2.02 0.001 (hs) normal spacing 0.56 0.330 (ns) ttm crowding normal 3.57 0.000 (hs) spacing 4.7 0.000 (hs) normal spacing 1.13 0.236 (ns) m an di bu la r tam crowding normal 1.74 0.000 (hs) spacing 1.78 0.000 (hs) normal spacing 0.05 0.882 (ns) tpm crowding normal 3.38 0.000 (hs) spacing 3.26 0.000 (hs) normal spacing -0.13 0.815 (ns) ttm crowding normal 5.12 0.000 (hs) spacing 5.04 0.000 (hs) normal spacing -0.08 0.918 ( ns) correlation between the space discrepancy and segment measurements by using person’s correlation test, tam in both arches had direct significant correlation in crowding dentition group, this is came to be in agreement with the previous findings (15,16), while, maxillary tam had indirect significant correlation in spacing dentition group,the present finding may be attributed to genetic factors or racial variation of present sample, table (4). correlation between the maxillary and mandibular segment measurements by using person’s correlation test, there were highly significant direct correlations between each variable with its opposite variable in the opposing arch in all three groups of the sample; as shown in table (5). regarding to normal dentition group, the present finding agreed with the previous findings (11,24) who found that, correlation coefficient for the incisors group and the canines and premolars group between maxillary and mandibular arch were moderate to high correlation between the variables. regarding to crowding and spacing dentitions ,the present findings agreed with the previous findings (10) who found that, because of the pervasive, positive inter-correlations among crown sizes, people with large dimensions of one tooth are predisposed to have large dimensions of other teeth and vice versa. the conclusions that can be drawn from this study are: 1. no significant side difference for mdcd of the individual teeth in the dental arches of normal, crowding and spacing dentition groups. 2. the segment measurements (tam, tpm and ttm): j bagh college dentistry vol. 26(4), december 2014 mesio-distal crown pedodontics, orthodontics and preventive dentistry185 a. mostly higher in males than in females in both arches and in all three groups. b. significantly larger in crowded dentition group compared with normal dentition group in both genders. c. significantly smaller in spaced dentition in comparison to normal dentition group in males and no significant in females. d. significantly larger in crowded dentition group in comparison to spaced dentition group in both genders. 3. total anterior material in both arches had direct significant correlation with crowding malocclusion, while tam in the maxillary arch had indirect significant correlation with spacing malocclusion. table 4: correlation between the space discrepancy and segment measurements (mm) table 5: correlation between the maxillary and mandibular segment measurements (mm) arch teeth crowding spacing maxillary tam r 0.287 -0.297 p-value 0.043 (s) 0.036 (s) tpm r 0.174 -0.124 p-value 0.226(ns) 0.390 (ns) ttm r 0.251 -0.213 p-value 0.079(ns) 0.138 (ns) mandibular tam r 0.325 -0.168 p-value 0.021 (s) 0.242 (ns) tpm r 0.19 -0.19 p-value 0.187(ns) 0.186 (ns) ttm r 0.265 -0.199 p-value 0.063(ns) 0.167 (ns) references 1. nance hn. the limitations of orthodontic treatment. am j orthod oral surg 1947; 33: 177-223. 2. seipel cm. variation of tooth position. svensk, tandlakaretidskrift 39: supply; 1946. (cited by hunter ws, priest wr. errors and discrepancy in measurement of tooth size. j dent res 1960; 39 (2): 405-13. 3. lavelle cl, flinn rm, foster td, hamilton mc. an analysis into age changes of the human dental arch by a multivariate technique. am j phys anthropol 1970; 33: 403–11. 4. mckeown hf, robinson dl, elcock c, al-sharood m, brook ah. tooth dimensions in hypodontia patients, their unaffected relatives and a control group measured by a new image analysis system. eur j orthod 2002; 24(2):131–41. 5. gungor ay, turkkahraman h. tooth sizes in nonsyndromic hypodontia patients. angle orthod 2013; 83(1):16-21. (ivsl). 6. magnusson te. an epidemiologic study of dental space anomalies in iceland schoolchildren. groups arch teeth mandibular tam tpm ttm normal maxillary tam r 0.742 0.771 0.829 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) tpm r 0.59 0.778 0.775 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) ttm r 0.734 0.856 0.885 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) crowding maxillary tam r 0.582 0.398 0.516 p-value 0.000 (hs) 0.004 (hs) 0.000 (hs) tpm r 0.582 0.82 0.824 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) ttm r 0.645 0.694 0.756 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) spacing maxillary tam r 0.736 0.657 0.751 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) tpm r 0.718 0.837 0.865 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) ttm r 0.774 0.808 0.869 p-value 0.000 (hs) 0.000 (hs) 0.000 (hs) j bagh college dentistry vol. 26(4), december 2014 mesio-distal crown pedodontics, orthodontics and preventive dentistry186 community dent oral epidemiol 1977; 5(6): 292– 300. 7. king l, harris ef, tolley ea. heritability of cephalometric and occlusal variables as assessed from siblings with overt malocclusions. am j orthod dentofacial orthop 1993; 104(2):121–31. 8. mugonzibwa ea. variation in occlusal and space characteristics in a series of 6 to 18-year-olds, in ilala district, tanzania. african dent j 1992; 6:17–22. 9. proffit wr, fields hw, sarver dm. contemporary orthodontics. 5th ed. st. louis: mosby elsevier; 2013. 10. agenter mk, harris ef, blair rn. influence of tooth crown size on malocclusion. am j orthod dentofacial orthop 2009; 136(6):795-804. 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(ivsl). ghada f.doc j bagh college dentistry vol. 25(3), september 2013 expression of matrix basic sciences 176 expression of matrix metalloproteinase-2 in the extracellular matrix of osseointegrated and diseased implants ghada i. al-duboni, b.sc., m.sc., ph.d. (1) abstract background: recently with improvement of dental implantology science, osseointegrated implants show a considerable durability, however; failures are not completely avoidable. matrix metalloproteinase-2 (mmp-2) expression is disturbed in many pathological conditions such as peri-implantitis and periodontitis. this study was carried out to investigate the tissue expression of mmp-2 in the extracellular matrix of osseointegrated and diseased implants. subjects and methods: gingival biopsies were collected from six patients having osseointegrated or working implants and twenty with diseased or non osseointegrated implants and (6) controls having no implants. in situ hybridization technique was used to analyze the changes in immunoreactivity of ecm-controlling mmp-2. results: the findings of the present study indicate that the expression of mmp2 was significantly elevated in failed implants versus healthy implants (p<0.01). in addition, mmp-2 was detected in peri-implant sites with ongoing bone loss, cavitations and inflammatory reaction. conclusion: the in situ hybridization technique, showed clear evidence that mmp-2, which is involved in the process of osseointegration and bone remodeling, increase greatly in the presence of bone destruction, cavitations, severe inflammation and fibrous tissue formation. the data link titaniuminduced bone remodeling to changes in expression and distribution of mmp-2. keywords: dental implant; osseointegration; matrix metalloproteinase-2 (mmp2). (j bagh coll dentistry 2013; 25(3):176-182). introduction although implant-supported oral rehabilitation has gained worldwide popularity throughout the last decades due to its efficient clinical success rate and substantiated improvement of individual's quality of life [1,2]. recent reports on the long-term success of implant therapy have presented surprisingly high prevalence rates of periimplant diseases; perimucositis and peri-implantitis [3] which has been reported to occur in 6–10% of the installed implants and eventually can lead to implant mobility and loss [4,5]. in the initial stage, plaque accumulation can cause perimucositis, a reversible inflammation of the soft tissues surrounding functional implants [6]. periimplantitis is defined as an inflammatory process, with microorganisms associated in patterns known from the chronic periodontitis of natural teeth, affecting soft and hard tissues surrounding an osseointegrated implant associated with breakdown of the peri-implant epithelial seal, pocket formation, purulence, and progressive bone loss [7,8] it is well known that periodontal bacteria are the main causative agents inducing the initiation of periodontitis and peri implantitis. although dental implant therapy has been considered to have an excellent prognosis, peri-implantitis, subsequent progression and disease severity are also determined by the host immune response [9] (1)lecturer. department of basic sciences. college of dentistry, university of baghdad. the degradation of peri-implant and periodontal tissues can be mainly mediated by matrix metalloproteinases (mmps). bone matrix turnover is regulated by the extracellular zincdependent endopeptidase, family of matrix metalloproteinases (mmps) comprising collagenases, gelatinases, stromelysins and membrane-type mmps [10]. bone development and remodeling requires activity of mmps for matrix maintenance and repair, bone resorption and the coupling to bone formation [11] fibrillar collagens are the major components of periodontal extracellular matrix, during periodontal homeostasis and pathologic conditions they are cleaved into smaller fragments by collagenases (mmps -1, -8, and -13) and further degraded by active gelatinases (mmps -2 and -9) and other non specific tissue proteinases [12]. furthermore both mmp-2 and mmp-9 (gelatinase a&b) have been implicated in bone resorption that results in the loosening of prostheses [13] matrix metalloproteinase-2 (also known as gelatinase a or type iv collagenase) is a 72 kda enzyme in humans encoded by the mmp2 gene [14]. mmp-2 is responsible for the breakdown of type iv collagen of the extracellular matrix, which is a major structural component of a typical basement membrane [15]. in addition, mmp-2 is also able to cleave native type i collagen, which is the abundant component of gingival connective tissue matrix, this protein is widely expressed by a number of normal and transformed cells j bagh college dentistry vol. 25(3), september 2013 expression of matrix basic sciences 177 [16].mmp-2 plays a critical role in invasion, metastasis, angiogenesis and tissue remodelling [17]. it has been immunolocalized in fibroblasts and macrophages, as well as in epithelial cells of gingival tissues in periodontitis affected patients [18]. elevated levels of matrix metalloproteinase-2 have also been detected in gingival crevicular fluid [19], peri-implant sulcular fluid [20] and gingival tissues of periodontititis / peri-implantitis patients [21]. therefore, the present study was performed to investigate the tissue expression of mmp-2 in the extracellular matrix of osseointegrated and diseased implants. subjects and methods a total number of 32 subjects were enrolled in this study. patients were attending the department of maxillofacial surgeryspecialization surgical hospital, alwasity hospital, alkarkh hospital, and al-mamoon dental center. partially edentulous patients of age range (4060) were grouped in to three groups, (6) with working osseo-integrated implants (2 male and4 female), (20) patients with at least one failed or diseased implants (7 male and 13 female), beside (6) randomly taken healthy control subjects (3 of each sex). identifying socio demographic information's together with radiographic and clinical evaluation including pain, mobility, bone loss, suppuration, peri-implantitis were recorded for each subject. nevertheless criteria of failing implants were judged by the maxillofacial surgeon. flap surgery was performed where gingival biopsy taken, fixed with formaldehyde and paraffin sections performed for in situ hybridization technique as recommended in leaflet with the kit [maxim biotech. usa cat no. ih60001 (ihd-0050). statistical analysis: spss statistical analysis was used. semirnovkolmogorov test was used to find the frequency distribution for selected variables. nonparametric tests were used to assess the statistical significance for these variables. mann whitney test was used to assess the statistical significance of difference in median of quantitative variable between two groups. kruskallwallis test was used to assess the statistical significance of difference in median of quantitative variable between more than two groups bonferonni ttest was used to assess further exploration of statistical significance of difference in mean between each pair of groups. results in this study ish was attempted in order to identify the cellular types expressing mmp-2 cdna and the changes in distribution of this endoproteinase in gingival tissue biopsies taken from patients post dental implantation. the result reported the changes in mmp2 levels among those patients relative to controls. the histological analysis of titanium bone interface following 8 wks of implant surgery indicates successful osseointegration with minimal inflammatory reaction and minimum expression of mmp2, while the ecm of the implant bone interface showed an increase expression of mmp2 in diseased implants. figure (1 and 2) show clear evidence of increase in expression of mmp2 in failed implants versus healthy implants an increase expression of mmp2 was associated with the presence of bone destruction , cavitations , inflammation , granulation tissue in addition to fibrous tissue formation table(3,4,5,6 and7) the differences in mmp-2 score and intensity among the three study groups is glanced in table 1 figure 1&2.the marker score was clearly but not significantly higher among failure group 10(50%), 6(30%) and 4(20%) at low, intermediate and high grades respectively, compared to osseointegrated group (p-value=0.34), while significant higher scores were seen in failure group compared to controls (p-value=0.04) table 1, fig 1. furthermore higher but not significant marker intensities was observed in failure group12 (60%), 4(20%) (x2) at low, intermediate and high grades respectively, compared to osseointegrated group (p-value=1.0) table 1, fig 2. talking about the correlation between subjects expressing bone destruction in histopathology compared to those having no evidence of bone loss, higher intermediate scores 4(36%) and intensity 3(2.3%) were seen in the failure group than those in osseointegrated implant group ,although these differences did not reach the statistical significance (p-value=0.2 and 0.19) respectively. (table 2) as clearly shown in table 3 the marker values reach the statistical significance, they were increased with increasing severity of cavitations 41.2% and 17.6% at intermediate and high grades respectively compared to negative ones(pvalue=0.014)and (23.5%) or both intermediate and high intensities (p-value=0.003). although gingival tissues reflects different grades of inflammatory reaction, heavy inflammation of 6(46.2%), 4(30.8%), 3(23.1%) were associated with low, intermediate and high scores respectively (p value=0.2 ns)(r=0.34ns), the heaviest inflammatory reaction 9(69.2%) was seen in tissues expressing low marker intensity (p value=0.19 ns) table 4. j bagh college dentistry vol. 25(3), september 2013 expression of matrix basic sciences 178 similar association was seen in table 5 regarding the presence of granulation tissue in which 8(47.1%), 6(35.3%), 3(17.6%) positive values were seen in the three marker scores respectively (p value=0.07) and 11(64.7%), 3(17.6%), 3(17.6%) positivity related to intensities (p value=0.16). discussion integration of external titanium fixtures into living bone (osseointegration) occurs through active bone remodeling [22], resulting in sensory neuronal changes, these changes were associated with permanent pure titanium implants rather than bone surgery alone [23]. it is well known that the peri-implant diseases are characterized by implant loosening, destruction of collagen fibers and other extracellular matrix components in periodontal tissues that is likely to be mediated, to a significant extent, by the host cells derived mmps and many studies have establish the relationship between these endoproteinases and periodontal / peri-implant diseases. tissue degradation by the matrix metalloproteinase-2 (gelatinase a) is pivotal to inflammation and metastases, however, both mmp-2 and mmp-9 have been implicated in bone resorption that results in the loosening of prostheses [12]. this suggests that matrix metalloproteinases are both effectors and regulators of the inflammatory response [24]. in the present study, ish was assessed to quantify and localize the expression of mmp-2 in gingival tissues of controls, versus healthy and diseased implant biopsies which showed that the number (score) and intensity of mmp2 signals positive cells varied between the three study groups. gelatinase a (mmp-2) cdna was most frequently found in diseased implants and less in osseointegrated ones. although this level was not significantly different between the two groups, the observation pointed out that mmp2 signals found mainly in fibroblast cell sites in biopsies of diseased implants specially when there is bone destruction , cavitations and inflammation more extensive than healthy ones and controls, this might explain the process of remodeling which occur during the osseointegration process, however, the presence of bacterial infection in diseased implants might participate in the process of degradation of ecm and activation of fibroblast to produce mmps. dahan et al [25] use ish and rt-pcr to quantify and localize the expression of mrna for mmp-1, mmp-2 and mt1-mmp and stated that the mrna encoding those mmps are most frequently found in periodontitis affected and healthy patients, and they were expressed in fibroblastic spindle-shaped cells at sites of connective tissue remodeling or chronic inflammation. meikle et al [18] stated that the number and distribution of mmp-1,mmp-2 and mt1-mp positive cells varied considerably not only between individual biopsy specimens but also from section to section within the same specimen, and their observation pointed out that fibroblasts are the major cell origin for mmp-2 and mt1mmp production. similarly, corroti et al [26] and paula-silva et al [27] observed the critical role of mmp-2 and mmp-9 in the development of inflammatory peri apical lesions and ecm degradation during the initiation and progression of apical periodontitis dale [28] suggests that the host response to microbial infection in periodontal tissues may lead to the altered production of human mmps and that the human, rather than bacterial proteinases are predominantly responsible for cleavage of the ln-332 molecule and for pathological changes in the junctional epithelium. an immunohistochemical examination done by yokohama et al [29] revealed that expression of mmp-2 and timp-1 mrna in the multinucleated giant cells that are present in fibrous granulation tissue of the membranes obtained from the loose bone-implant interface, was demonstrated by in situ hybridization, where mmp-2 was immunolocalized mainly in the fibroblasts while timp-1 was localized in the endothelial cells of the blood vessels and weakly in fibroblasts other investigators as di nezza et al [30] studied the actions of many extracellular-matrix degrading enzymes, matrix metalloproteinases (mmps) in tumorigenesis using ish and in situ zymography and found that mmp-9 and mmp-2 mrnas were predominantly observed in tumor epithelial cells as well as in the stroma to varying degrees. as far as many investigators focus on the increased expression and activity of mmp-2 and 9 in tumors which leads to the degradation of basement membranes, an essential step in tumor invasion. in this respect, a correlation between a high expression of mmp-2 and reduced survival in breast cancer patients has been proved by andrea köhrmann et al [31] vasaturo et al [32] observed a significant and direct correlation between the concentrations of mmps 2 and 9 and tumor histological grade of breast cancer, and suggests that the quantification of plasma mmp 2 and mmp 9 levels may provide j bagh college dentistry vol. 25(3), september 2013 expression of matrix basic sciences 179 additional clinical information of the tumor and it is, therefore, a possible prognostic index for breast cancer. as a conclusion, mmp-2 (gelatinasea) is an important enzyme envolved in the process of remodeling of ecm of bone tissue interface but there is an imbalance increase in mmp2 in diseased and failed implants. furthermore the results of this study suggested the gingival fibroblasts as a major source for mmp-2 and evidenced the fact that the host endoproteinases plays an important role in the degradation of the extra-cellular matrix components. quantification by in situ hybridization of the dna-encoding mmp-2 levels, and other degradative enzymes, will help in understanding the molecular mechanisms underlying peri-implant diseases and confirm the possible role of the matrix metaloproteinases as predictors of active periods of peri-implantitis and alveolar bone loss. references 1. arakawa h, uehara j, hara es, sonoyama w, kimura a, kanyama m, matsuka y, kuboki t. matrix metalloproteinase-8 is the major potential collagenase in active peri-implantitis. j prosth res 2012; 56(4): 249-55. 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(ivsl). 32. vasaturo f, solai f, malacrino c, nardo t, vincenzi b, modesti m, scarpa s. plasma levels of matrix metalloproteinases 2 and 9 correlate with histological grade in breast cancer patients. oncol lett 2013; 5(1): 316-320. (ivsl). table 1: the difference in mmp2 score and intensity between the 3 study groups implant failure osteo-integrated implant contro l subjects n % n % n % mmp2 score low 10 50 4 66.7 6 100 intermediate 6 30 2 33.3 0 0 high 4 20 0 0 0 0 p (mann-whitney) for difference between: osteo-integrated implant x control =0.14[ns] osteo-integrated implant x implant failure =0.34[ns] implant failure x control =0.04 mmp2 intensity low 12 60 6 100 6 100 intermediate 4 20 0 0 0 0 high 4 20 0 0 0 0 p (mann-whitney) for difference between: osteo-integrated implant x control =1[ns] osteo-integrated implant x implant failure =0.07[ns] implant failure x control =0.07[ns] total 20 100 6 100 6 100 j bagh college dentistry vol. 25(3), september 2013 expression of matrix basic sciences 181 table 2: the difference in mmp2 score and intensity by presence of bone destruction on histo-pathological examination bone destruction negative positive n % n % p mmp2 score low 5 55.6 5 45.5 0.8 [ns] intermediate 2 22.2 4 36.4 high 2 22.2 2 18.2 mmp2 intensity low 7 77.8 5 45.5 0.17 [ns] intermediate 1 11.1 3 27.3 high 1 11.1 3 27.3 total 9 100 11 100 table 3: the difference in mmp2 score and intensity by presence of cavitations on histopathological examination cavitations negative positive n % n % p mmp2 score low 13 86.7 7 41.2 0.014 intermediate 1 6.7 7 41.2 high 1 6.7 3 17.6 mmp2 intensity low 15 100 9 52.9 0.003 intermediate 0 0 4 23.5 high 0 0 4 23.5 total 15 100 17 100 table 4: the difference in mmp2 score and intensity by severity of inflammatory reaction on histo-pathological examination inflammatory reaction negative mild moderate heavy n % n % n % n % p mmp2 score low 5 100 5 62.5 4 66.7 6 46.2 0.2 [ns] intermediate 0 0 2 25 2 33.3 4 30.8 high 0 0 1 12.5 0 0 3 23.1 r = 0.34 [ns] mmp2 intensity low 5 100 7 87.5 3 50 9 69.2 0.19 [ns] intermediate 0 0 1 12.5 1 16.7 2 15.4 high 0 0 0 0 2 33.3 2 15.4 r = 0.26 [ns] total 5 100 8 100 6 100 13 100 table 5: the difference in mmp2 score and intensity by presence of granulation tissue on histo-pathological examination granulation tissue negative positive n % n % p mmp2 score low 12 80 8 47.1 0.07 [ns] intermediate 2 13.3 6 35.3 high 1 6.7 3 17.6 mmp2 intensity low 13 86.7 11 64.7 0.16 [ns] intermediate 1 6.7 3 17.6 high 1 6.7 3 17.6 total 15 100 17 100 figure 1: component bar chart showing the difference in mmp2 score between the 3 study groups figure 2: component bar chart showing the difference in mmp2 intensity between the 3 study groups j bagh college dentistry vol. 25(3), september 2013 expression of matrix basic sciences 182 table 6: the difference in mmp2 score and intensity by type of fibrous tissue observed on histopathological examination fibrous tissue delicate bandscoarse heavy collagen n % n % p mmp2 score low 14 77.8 6 42.9 0.042 intermediate 3 16.7 5 35.7 high 1 5.6 3 21.4 mmp2 intensity low 16 88.9 8 57.1 0.045 intermediate 1 5.6 3 21.4 high 1 5.6 3 21.4 total 18 100 14 100 rusul.doc j bagh college dentistry vol. 28(1), march 2016 the electrophoretic restorative dentistry 41 the electrophoretic deposition of nano al2o3 and agno3 on cpti dental implant (an in vitro and in vivo study) rsul n. turky, b.d.s. (1) raghdaa k. jassim, b.d.s., m.sc., ph.d. (2) abstract background: even the wide use of dental implants, still there is a proportion of implants are failed due to infection. much considerable attention has been paid to modify the implant surface. coating of dental implant with a biocomposite material of suitable properties can improve osseointegration. and this is the main concern of this study. the aim of present study was to evaluate the use of a biocomposite coating of dental implant with (ceramic nano al2o3 and metalic agno3) on the bond strength at bone – implant interface and tissue reaction. materials and methods: a total number of forty-eight screws, cpti dental implant used in this study. half of these screws were coated with a biocomposite material of nano (al2o3and agno3), this was done by using electrophoretic deposition method (efd). in invitro part of the study, analysis of the coated surface was done using: x ray diffraction (xrd), atomic force microscope (afm), energy dispersive x-ray spectroscopy (edx), optical microscopy and scanning electron microscope (sem). in invivo part of study, 10 white male new zealand rabbits were used, and a screw type of dental implant [uncoated and coated with nano (al2o3and agno3)] were implanted in each tibia of rabbit. then biomechanical and histological test were performed after 2 and 4 weeks healing intervals. results: the results of biomechanical test showed a higher torque mean values of (m+sd):(14.91n.cm+2.7)and (22.5 n.cm +5.31) after 2 and 4 weeks respectively. in histological examination of coated screws at 2 weeks, there isa bone trabeculae occupies a base of implant bed with osteoblast andosteocyte. at 4 weeks, there is a progress in the healing process around dental implant, and this includes: -new bone with haversian canals, osteoblast and osteocyte. conclusion: biocomposite coating of dental implant with alumina and silver nitrate can be made by electrophoretic deposition method (epd), and a multifunctional surface has been created. keywords: electrophoretic deposition, alumina, screw dental implants, torque. (j bagh coll dentistry 2016; 28(1):4147). introduction dental implants have many functions like support the crown, abutment of bridge and removable denture. a strong bond forms between bone and implant is an important factor in success of dental implant (1). various researches had been done for evaluationof tissue response to the implant surface and how can the characteristics of the surface, such as chemistry of surface, type ofcoatings and sterilization procedures can affect the longand shortterm stability of the metallo-biological interface (2-4). however, it is difficult to meet all the requirements such as antibacterial ability, biocompatibility, osseointegration, and mechanical properties, but the essential factors for prolong stability of the implant are good biocompatibility and rapid osseointegration (5). an aluminum oxide coating substrates showed improvement in corrosion resistance compared to uncoated titanium substrates (6).ceramic materials such as alumina, partially stabilized zirconia, and titania possess high wear resistance, mechanical strength, and good biocompatibility (7). when preparing implant sockets, the infection or trauma to the alveolar bone appears to be one of the causative factor of early implant losses (8), so researchers are increasingly focusing on the development of the antibacterial property of implants (9). in literature, the usage of inorganic antibacterial materials give better results than those using of organic antibacterial materials, in the field of durability, toxicity and selectivity of action. therefore, the benefit of (ag ion) as an antibacterial agent has been known and ag is currently used as antibacterial coatingsin several applications (10,11). epd technique is more efficient techniques and can be used for deposition of nano size particles on complex shape components. also, this method can be easily done, versatile and low cost (12,13). electrophoretic deposition process is made directly by the application of an electrical field on a stable colloidal suspension. the wide using of electrophoretic deposition (epd) method attracted much of interests that can be deposited with any size of a particle in powder form such as oxides, metals, polymers, carbides and nitrides (14-16). in this study, using nano al2o3 and agno3 biocomposite coating cpti for improvement of functionality and a biological efficacy of titanium implants. (1)master candidate, department of prosthetic dentistry, college of dentistry, university of baghdad. (2)assistant professor, department of prosthetic dentistry, college of dentistry, university of baghdad. j bagh college dentistry vol. 28(1), march 2016 the electrophoretic restorative dentistry 42 materials and methods in vitro study two types of a pilot was done, the first one is selection of the suitable suspension which was prepared according to the type of binder, either iodine or poly vinyl alcohol. and according to the result of pilot study, using suspensionof iodine found to be the best in terms of suspension stability and deposition features. this suspension consists of 4g nano alumina powder, 0.5g silver nitrate powder and 0.4g iodine, than these powders added to the solvent which was the 50ml ethanol absolute ≥ 99.8% in a container over a stirrer. the stirring at normal speed was continued until a colloidal suspension was obtained at room temperature. then, 2 drops of phosphate ester as dispersant agent was added to the suspension before coating. a second pilot study was done to select suitable time used for coating. this pilot study consist of usingthree times which are (0.5 min, 1 min, 2min,and 3min) at 70v, the results showed thatthe use of 1 min for coating plats better in the term of homogeneity and uniform thickness of coating. analysis of coated surface was done by: x-ray diffraction phase analysis was studied x-ray diffractometer using cu kα radiation. the 2 angles were swept from 2060° in step of one degree. the peak indexing was carried out based on the joint committee on powder diffraction standards (jcpds). structural surface characterization scanning electron microscope was used for testing the nano surface feature as follows: asurface analysis for studying the surface morphology and topographical characteristics of coated specimen. 1-optical microscope was used forexamination of the surface feature of coated layer. 2scanning electron microscopy (sem): this was used for examination of the surface in nano scale. it includes an electron beam scanned over the sample surface. the electron beam induces a larger depth of focus than a regular light beam and images at very high resolution can be recorded. bmaterial characterization energy-dispersive x-ray spectroscopy (edx) analysis is performed within the sem instrumentation. when the incoming electron beam interacts with the sample, this can cause emission of x-ray photons due to the excitation and relaxation of sample atoms. since the emitted x-ray photons are characteristic for each element, edx is used for both qualitative and quantitative elemental analysis (17). 2-design of study the screws were categorized according to the test performed into: 1. mechanical (torque measurements) group: (32 screws) the screws were divided into: a. control group (16 screws): this group includes 8 screws for each healing interval (2 and 4weeks). b. experimental group (16 screws): this group includes 8 screws for each healing interval (2 and 4 weeks) coated with (al2o3and agno3). 2. histological test group: (8 screws) in this test the screws were divided into: a. control group (4 screws): include 2 screws for each healing interval (2 and 4weeks) b. experimental group (4 screws):this group includes 2 screws for each healing interval (2 and 4 weeks)coated with (al2o3and agno3). 3in vivo study ten healthy adult male rabbits weighing 2 -2.5 kg were used. the age of the rabbit was from 1012 months. animals were fed with standard pellets, jet and carrot and had free access to tap water. the rabbits were then left for two weeks in the same environment before the surgical operation. a subcutaneous anti parasite agent (ivermectin) was given in a dose of 1ml injection. this was given to ensure parasite free animals.also an antibiotic cover with oxytetracycline 20% (0.7ml/kg) intramuscular injection was given for 3 days to exclude any infection.a surgical procedure was performed according to helsinki (18). the total animals were dividedaccording to healing interval into 2 groups (2 and 4 weeks). at each time interval, one animal was sacrificed for histological study, and 4 animals were sacrificed for a mechanical test. all implants were implanted in tibiae of rabbit, each tibia received two implants (coated and uncoated) each rabbit was anesthetized by ketamine hydrochloride (1ml/kg b.w) and xylazine 20mg/ml (1ml/kg b.w.)(19). both tibiae were shaved and cleaned with a mixture of ethanol and iodine.later on, the incision through skin and fascia and muscles was made on the lateral side of rabbit’s leg to expose the medial side of the tibia. bone penetration was performed witha serial of drills (2,2.5,2.8) by intermittent pressure with continuous cooling with normal saline.coated screw was removed from an air tight plastic sheet, j bagh college dentistry vol. 28(1), march 2016 the electrophoretic restorative dentistry 43 placed in the first hole (proximal one) using a screw driver first then a torque meter, so 5mm length of screw introduced in bone completely, then uncoated screw holds to second hole (distal one), thensuturing of muscles was done with absorbable catgut suture 3/0 followed by skin suturing with silk suture 3/0. postoperative care was performed by giving long acting systemic antibiotic (oxytetracycline 20%, 0.7ml/kg b.w.) for 5 days after surgery. mechanical test (torque test) four animals were used forthis test. it was performed while the animal was anesthetized in the same manner mentioned in the implantation procedure. incision was made at lateral side of tibia then fascia and muscles were reflected to expose the implants. tibia was supported firmly. a torque removal test was performed by engaging the head of torque meter (dentium f28d104, korea) into the slit in the head of the implant. the removal torque was expressed in newton centimeter (n.cm). histological test for each healing interval (2-4 weeks) one animal was used for histological test.it was anaesthetized with anesthetic solution. cutting of the bone around the implant was performed using a disk in low rotating speed hand piece with normal saline cooling. cutting was made about 5 mm away from the head of the implant to prepare a boneimplant block for histological study. bone-implant blocks were immediately stored in 10% freshly prepared buffered formalin (20,21) and left for 3 days for fixation results a-in vitro part of study phase identification the results of x-ray diffraction patterns of coated plates shown in figure 1. then peak indexing was carried out based on the jcpds (joint committee on powder diffraction standards) international centre for diffraction data, icdd file # 44-1294 for titanium, #43-0649 for agno3, #43-1484 for al2o3 after epd, it is evident from the figure that the surface of a specimen is well covered with al2o3and agno3,because most of the diffraction peak could be indexed to al2o3phase according to jcpds,the strongest line of this phase are (012), (110), (113), (024) and (116) at2 with the following values respectively (25.576), (37.767), (43.340),(52.548),(57.498) respectively. the diffraction peak could be indexed to agno3phase according to jcpds, the strongest line of this phase are (113),(112),(213) and (215) at 2 (31.878), (24.871), ( 39.080) and (53.791) besides, the pattern showed the presence of ti peaks (100), (101) and (002) at 2 (35.3376), (40.170) and (38.421) respectively. this is due to the penetration of xrays beyond the coated layer figure1: x-ray diffraction patterns of cpti specimen coated with al2o3 and agno3. nanosurface feature morphological analysis (sem) sem micrographs of cpti plate coated with al2o3 and agno3 showed that there were changes in the surface at low and high magnification. the sem micrograph of coated sample shows many irregular projections; and the picture appeared that the surface had a feature or a structure of nano particle as shown in figure 2. figure2: sem for coated plate measures some of particle size j bagh college dentistry vol. 28(1), march 2016 the electrophoretic restorative dentistry 44 nanostructural characterization (nano surface roughness analysis) scanning probe microscope analysisshows peaks and projections with the average roughness 4.43 nm as shown in fig 3 and the average grain size 54.98 nm. figure 3: average nano surface roughness of al2o3 and agno3coated cpti dental implant. elemental composition energy-dispersive x-ray spectroscopy (edx) analysis showed that the main components of the coated plate were al and ag as shown in fig 4. edx spectra coated sample indicates the presence of small amounts of silver within the surface (7.1%) and 84.5% of al+3. the appropriate composition of coated materials were found to be homogeneous all over the surface as screened by edx analysis at different surface positions as shown in fig 5. figure 4: edx-analysis of al2o3and agno3coatings on cpti plate figure5: sem/edx mapping of ag+ and al+3 b-in vitro part of study mechanical testing descriptive statistics of removal torque values of cpti screws coated with al2o3and agno3 after 2 weeks of implantation as shown in table 1, a higher torque mean value was needed to remove the implants coated with nano al2o3and agno3 (14.91 n.cm ) as compared with the torque mean value of uncoated implant (10.75 n.cm ) . also in table 1 descriptive removal torque mean values of cpti screws after4 weeks of implantationrevealed, a higher torque mean value for the implants coated with nano al2o3and agno3 (22.5 n.cm) as compared to the torque mean value for uncoated implants (18.09 n.cm). table 1: removal torque mean values for coated and uncoated implants at different time intervals and anova test. time intervals groups mean n/cm s.d anova f test p value 2 weeks coated 14.91 2.7 13.94 0.000 uncoated 10.7 2.2 4 weeks coated 22.5 5.3 uncoated 18.09 3.9 j bagh college dentistry vol. 28(1), march 2016 the electrophoretic restorative dentistry 45 table 2: multiple comparison (lsd) among all pairs of different periods of healing times in each group of cpti implant screws independently groups mean difference sig. control 2weeks coated 2weeks 4.16025 .035 control 4weeks 7.33563 .001 coated 4weeks 11.7488 .000 coated 2weeks control 4weeks 3.17538 .103 coated 4weeks 7.58862 .000 control coated 4weeks 4weeks 4.41325 .026 histological testing after 2 weeks of implantation, in figure 6 the histological feature of nanoal2o3and agno3 coated cpti implants showed bone trabeculae (bt) occupies the apex of the thread and base of implant bed close to cutting bone (cb). in figure 7 a numerous blood vessels (arrow) with active proliferating osteogenic cells (arrow heads) occupies a base of implant bed. fig 6: microscopic photograph view ofal2o3and agno3 coated ti implant after 2 weeks of implantation. hand e×10 fig 7: microscopic photograph view of al2o3and agno3 coated ti implant after 2 weeks of implantation. hand e×40 after 4 weeks of implantation, in figure 8 the histological feature of al2o3and agno3 coated cpti implants illustrated immature new bone (nb) with haversian canals (arrow), filled base of implant impression bed. also as shown in figure 9 new bone shows osteoblast (arrows) and osteocytes (arrow heads). fig 8: microscopic photograph view of al2o3 and agno3 coated ti implant after 4 weeks of implantation. hand e×10 fig 9: microscopic photograph view for the al2o3and agno3 coated ti implant after4 weeks of implantation. hand e×40 discussion in this study, among various strains, adult new zealand white male rabbits were selected to be used as an animal model. this is for manipulation and rapid bone healing response as compared to other models, and these strains are less aggressive in nature and have less health problems as compared with other breeds (22). the tibial sites in the rabbit were chosen to mimic the clinical situation, and since the dimensions of this bone correspond well with human alveolar space. surgically, this model provides low morbidity with easy access to the medial proximal tibia for implant placement. the morphologic characteristics of the rabbit tibia allow for implant fixture to engage cortical bone at its coronal aspect and marrow in the apical area(23). tibia used as a suitable location for implant due to the presence of cancellous bone in addition to cortical bone. also, it can provide a cushioning effect and prevents the cortical bone from splinting. it is better to choose a healthy large animal more than 2 to 2.5 kg since it had a better capacity to withstand surgical trauma and less j bagh college dentistry vol. 28(1), march 2016 the electrophoretic restorative dentistry 46 postoperative problems and leading to a better survival rate (24). the excellent mechanical properties and chemical stability of alumina encourage to be used as coated material on a metallic implant surfaces. alumina coatedti6al4v can improve corrosion resistance of material and biocompatibility (6, 25). in the field of research, it is well known that nobel metals had biocompatibility and non-toxic to eukaryotic cells. one of these metals, silver hasa history in medical application as preventive effect of diseases and infections in little concentration (26,27). in energy-dispersive x-ray spectroscopy (edx) analysis, mapping of the coated plate showed a fairly uniform distribution of particles. in microstructural analysis, the main components of the tested plate were al+385% and ag+7.1%. this can explain that the 5g of nano al2o3 and 0.5g of agno3 used in this study suitable for coated dental implant by the electrophoretic deposition method, especially when the mapping concentration can provide an antimicrobial effect on staphylococcus epidermis and klebsiella pneumonia (28). in this study, a higher torque value was needed to remove coated screws than uncoated one, this was between 2 and 4 weeks of implantation, and the explanation of this might be due to theincrease in the bond strength at the bone–implant interface in coated implants. this agreed with the study of salman (25). nanoscale topography of implant surface affectboth cell adhesion and cell motility and promote the osteoinductive molecular program for adherent osteoprogenitor cells, also nanoscale alterations may promote bone bonding behavior at bone implant interface (29,30). the results mentioned that the torque mean value after 4 weeks of implantation higher significantly than 2 weeks of implantation, this indicated the progress of osseointegration leads to increase the bond between implant and bone. this come with the results of histological test which indicated a new bone formation with active proliferating osteogenic cell after 2 weeks of implantation, and immature new bone with havarsion canal filled the base of implant impression bed after 4 weeks of implantation, this indicate progress in healing of bone with time, that might lead to increase bond strength at boneimplant interface in the coated implant, also was suggested that the bone formation in response to the coating depend on better biocompatibility of the material which greatly affect the biomechanical properties at bone –implant interface with no sign of inflammation. this might be due to the presence of ag which can promote bone formation. as silver has an antibacterial action on the coated surface, this make the process of bone formation earlier and rapid. this might be due to the presence of ag which can promote bone formation. the results of the present study strongly indicate that osseointegrtion can be obtained when coated implants are implanted in a living bone with a favorable biological environment for bone formation. the biological significance of different healing reactions is of critical importance in attempting to unravel the role of surface material in ossointegration of bone-implant interface (31,32). the histological analysis of all groups showed new bone trabeculae formation, with active osteoblats and osteocytes on borders. also, it is clear from the obtained results that no inflammatory reaction was observed during the period of the implantation. this is agreed with the results of yunzhi et al., (33). from histological results of this study, the evidence of bone formation on coated cpti implant suggests that the woven bone formation began in the second weeks after placement. osteoid tissue with numerous bone with progenitor cells around. the bone marrow showed active blood vessels, which indicate the beginning of new bone formation. these findings are supported by the works of lins et al., and cooper(34,35). from the results of the study, it can be concluded that: 1. it is can be successfully synthesise a biocomposite coating and a multifunctional surface of nano alumina and silver nitrate by electrophoretic deposition method (epd), with homogenous and uniform thickness of coating. 2. coating of dental implant with bio composite material results in a high torque removal mean values after 2and 4 weeks implantation, and there is a highly significant difference for the torque mean values after 4 weeks implantation as compared with 2 weeks with improved biocompatibility. references 1tanner, maiden, lee, shulman, weber. dental implant infections. clinical infectious diseases 1997; 25(2):s213–7 2stanford cm, keller jc, solursh m. bone cell expression on titanium surfaces is altered by sterilization treatments. j dent res 1994; 73:1061-71. 3 swart km, keller jc, wightman jp, draughn ra, stanford cm, michaels cm. short-term plasmacleaning treatments enhance in vitro osteoblast attachment to titanium.j oral implantol 1992;18:130-7. j bagh college dentistry vol. 28(1), march 2016 the electrophoretic restorative dentistry 47 4 michaels cm, keller jc, stanford cm. in vitro periodontal ligament fibroblast attachment to plasma cleaned titanium surfaces. j oral implantol 1991; 17:132-9. 5lindhe j, berglundh t, ericsson i, liljenberg b, marinello c. experimental breakdown of periimplantand periodontal tissues. a study in the beagle dog. clin oral implants res 1992; 3: 9–16. 6zykova a, vladimir s , anna y, leonid s , renata r , jerzy s, stas y. formation of solution-derived hydroxyapatite coatings on titanium alloy in the presence of magnetron-sputtered alumina bond coats. the open biomedical engineering journal. 2015; 9(suppl 1-m16): 75-82 7zykova, v. safonov, j. smolik, r. rogowska, v. luk yanchenko, o. vyrva, and s. yakovin, the corrosion properties of zirconium and titanium loadbearing implant materials with protective oxide coatings, in: proc. 13th int. conf. pse 2012, linköping, sweden, vol. 2, pp. 388-392, 2013. 8 shulman lb. surgical considerations in implant dentistry. int j oral implantol 1988; 5: 37–41 9brook, p. evans, h. a. foster, et al., “highly bioactive silver and silver/titania composite films grown by chemical vapour deposition. j photochemistry and photobiology 2007; 187: 53–63. 10balamurugan a, balossier g, maquin dl, pina s, rebelo ahs, faure j, ferreira jmf. an in vitro biological and anti-bacterial study on sol-gel derived silver-incorporated bioglass system. dental materials 2008; 24: 1343–51. 11 huang hl, chang yy, meng-cheng lai mc, lin c r, lai ch, shieh tm. cytocompatibility and antibacterial properties of zirconia coatings with different silver contents on titanium. thin solid films 2013; 549:108–16 12boccaccini a. r, zhitomirsky i. application of electrophoretic and electrolytic deposition techniques in ceramics processing. curr opin solid state mater sci 2002; 6: 251–60. 13corni i, ryan mp, boccaccini ar. electrophoretic deposition: from traditional ceramics to nanotechnology. journal of the european ceramic soc 2008; 28:1353–67. 14tabellion c. electrophoretic deposition from aqueous suspensions for near-shape manufacturing of advanced ceramics and glasses-applications. j materials sci 2004; 39: 803–11. 15tabellion j, clasen r, electrophoretic deposition from aqueous suspensions for near-shape manufacturing of advanced ceramics and glasses— applications, journal of materials science. 2004; 39: 803–11. 16corni i, ryan mp, boccaccini ar, electrophoretic deposition: from traditional ceramics to nanotechnology. j european ceramic soc 2008; 28: 1353–67. 17goldstein j, newbury de, lyman c, echlin p, lifshin e, sawyer l, michael jr. scanning electron microscopy and x-ray microanalysis. 3rd ed. 2003. 18helsinki, finland. world medical association declaration of helsinki ethical principles for medical research involving human subjects. june 1964. 19jawed m. histological and mechanical evaluation of ossointegration of titanium implants by the modification of the thread design and/or coating with flaxseed (an experimental study in rabbits). master thesis, college of dentistry, university of baghdad, 2014. 20sheehan d, hrapchak b. theory and practice of histotechnology. 2nd ed. ohio: battelle press; 1980. 21shukur bn, jassim rk. evaluation of nano surface modification on cpti dental implant using chemical method: mechanical and histological evaluation. j bagh coll dentistry 2015; 27(3): 8-14. 22manjeet m, betsy s, bhat km. rabbit as an animal model for experimental research. dent res j (isfahan). 2012; 9(1): 111–8. 23dahlin c, sennerby l, lenkholm u, linde a, nyman s. generation of new bone around titanium implant using membrane technique: an experimental study in rabbits. int j oral maxillofac implant 1989; 4(1):1925. 24mapara m, thomas bs, bhat km. rabbit as an animal model for experimental research. dent res j (isfahan) 2012; 9(1): 111–8. 25salmany. a study of electrophoretic deposition of alumina and hydroxyapatite on tapered ti-6al-7nb dental implants: mechanical and histological evaluation. thesis, 2011 26sintubin l, verstraete w, boon n. biologically produced nanosilver: current state and future perspectives. biotechnol bioeng 2012. 27collart d, mehrabi s, robinson l, kepner b, mintz ea. efficacy of oligodynamic metals in the control of bacterial growth in humidifier water tanks and mist droplets. j water health 2006; 4: 149-56. 28ewald a, susanne kg, roger t, uwe g. antimicrobial titanium/silver pvd coatings on titanium. biomedical engineering 2006; 5: 22 29mendonca g, mendonca db, aragao fj, cooper lf. advancing dental implant surface technology--from micronto nanotopography. biomaterials 2008; 29(28): 3822-35. 30waheed as. mechanical and histological evaluation of nanozirconium oxide coating on titanium alloy (ti-6al-7nb) dental implants. a master thesis, college of dentistry, university of baghdad, 2013. 31ghasak hj, al-ameer ss, jawad sn. histological and histomorphometric analysis of strontiumchloride coated commercially pure titanium implantcompared with hydroxyapatite coating, j bagh coll dentistry 2015; 27(1):26-31 32davis je, park jy. critical issues in endosseous periimplant wound heling. in: bio-implant interface: improving biomaterials and tissue reactions. ellingsen ja, lyngtadaas sp, editors. usa: crc press llc, 2003. pp. 219-228. 33yunzhi y , sangwon p, yongxing l, kwangmin l, hyun-seung k, jeong-tae k,xianwei m, , kyohan k, hongbin j, xiaodu w, joo l. development of sputtered nanoscale titanium oxide coating on osseointegrated implant devicesand their biological evaluation. vacuum 2009; 83: 569–74 34lins l, santana e, falcao a, martin p, calmon tand sarmento v. the influence of hydroxyapatite on bone healing in titanium implants as shown by scanning electron microscopy. braz j morphol sci 2003; 20(1):25-29. 35 cooper lf. cellular interaction at commercially pure titanium implants. in: bio-implant interface: improving biomaterials and tissue reactions. ellingsen ja, lyngtadaas sp, editors. usa: crc press llc; 2003. pp. 165-181. microsoft word 2 jenan j bagh college dentistry vol. 32(3), september 2020 the impact of 8 the impact of caries experience on quality of life among dental students in iraq jenan o. almaas(1), ban s. diab(2) article doi: https://doi.org/10.26477/jbcd.v32i3.2894 abstract background: dental caries is generally given the highest priority in national oral health services for adult populations. yet, there is no study which has explored the impact on quality of life specifically related to dental caries in samples of dental students. the purpose of the current study was to assess the impact of caries experience on quality of life among dental students in three governorates in iraq. materials and methods: this observational study included 1364 dental students aged 18–22 years old, from three governorates. information on quality of life was obtained from a structured, self-administered questionnaire from the students who were willing to participate in the study. the data was collected, summarized and statistically analyzed. caries experience in the present study was determined by the decayedmissing filled surfaces (dmfs) indexed by who in 1997 in which all teeth were examined and all the third molars were included. results: regarding dental caries and the four quality of life domains, in each domain scores, ds component had the highest contribution to the dmfs followed by the ms component while fs components had the lowest contribution to the index. on the other hand, dmfs showed the lowest mean among the good scores of all domains and it had the highest mean among the poor type. conclusion: the quality of life among dental students is associated with caries severity as the dmfs and its components affected different domains regarding quality of life. keywords: caries experience, dental students, quality of life. (received: 3/6/2019; accepted: 28/7/2019). introduction dental students constitute a special population group concerning their oral health status and behavior since they have the best access to information and motivation for the prevention and treatment of oral diseases (1). on the other hand, their caries experience was found to be similar to that of other university students. they explained this by the fact that dmft index is irreversible while for caries initiation and development, a sufficiently long period of time is needed (2). caries is a multifactorial disease, in addition to ph fluctuations in the bacterial plaque or biofilm which in turn may be influenced by many factors of oral hygiene, diet, fluoride and salivary flow, a number of other important factors such as social class, income, education, knowledge, attitudes and behavior may be involved in disease causes (3). oral diseases such as dental caries are highly prevalent and their consequences are not only physical; they are also economic, social and psychological.they seriously impair quality of (1) phd student, department of pedodontics and preventive dentistry, college of dentistry university of baghdad (2) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. life in a large number of individuals and can affect various aspects of life, including oral function, appearance, and interpersonal relationships (4). quality of life is a ubiquitous concept that has different philosophical, political and health-related definitions. health-related quality of life is a patient-reported outcome usually measured with carefully designed and validated instruments such as questionnaires or semi-structured interview schedules which include the physical, functional, social and emotional well-being of an individual; its measurement was judged by a healthcare professional or similar (5). according to current knowledge, there is no previous iraqi study concerning the effect of dental caries on quality of life assessment among dental students in iraqi populations. this study was administered to a random sample at a public university with a caries experience profile. the aim of this study was to investigate how the oral health behavior and clinically-assessed dental caries are related to quality of life measured by whoqol-bref field trial version among dental students in iraq . corresponding author, drban.sahib@codental.uobaghdad.edu.iq j bagh college dentistry vol. 32(3), september 2020 the impact of 9 materials and methods all the students participating in the study gave their verbal and written informed consent at the beginning. the participants were informed that they could withdraw from the study at any time. ethical approval for this study was obtained by an official permission from iraqi universities/colleges of dentistry to facilitate conducting the research.this observational study was conducted at three universities (basra, anbar, mosel), during the period between march 2018 to march 2019. approximately 1364 dental students aged 1822 years old who attended the colleges of dentistry in the selected governorates in iraq were examined. for convenience, students from the non-government colleges of dentistry were not included, as the study targeted iraqi students from government universities only.the sample included both genders of the dental students (648 males and 716 females) with age range 18-22 years old. the participants should not had any chronic medical disease, not physically handicapped, and not exposed to psychological trauma during the last six months. the participants completed a questionnaire containing items regarding name, age, gender, year of study in the bachelor of dental surgery, geographical location and smoking status. all the answers of the questionnaire were confirmed by the researcher . self-administered whoqol-bref (field trial version) was used to evaluate the quality of life for the dental students into three groups: poor, fair and good scores (6-9). the applied cutoff level reflects public health perspectives and treatment needs, rather than detailed individual statements of symptoms. it was possible to derive four domain scores (physical, psychological, social and environmental domains). the four domain scores denote an individual's perception of quality of life in each particular domain. domain scores are scaled in a positive direction (i.e. higher scores denote higher quality of life). responses to the questions using a 5point likert scale. in the present sample, whoqol-bref domain scores discriminated statistically highly significantly between contrasted groups of dental students at p-value ˂0.05 (n=736, df=734). the reliability index for the whoqol-bref was assessed by using cronbach’s alpha which was 0.98. as a result of that, the indicator stayed on its version without drop of any item. caries experience in the present study was determined by the decayedmissing filled surface (dmfs) index by the who in 1997(10) in which all the teeth were examined and all the third molars were included. the examination should adopt a systematic approach to the assessment of dentition status. plain mouth mirror and cpi probe were used in the examination. data were statistically analyzed using spss version 22 software. according to the central limit theorem, in large samples (˃30 or 40), the sampling distribution tends to be normal, regardless of the shape of the data. the collected data were grouped and illustrated in tables, and the following statistical tests were carried out: means, standard error. the independent-samples ttest procedure was used to compare means for two groups of cases. anova (one way) was used to determine whether there are any significant differences between the means of more than two independent groups. when the pvalues were less than or equal to 0.05, they were considered as statistically significant and if the pvalues were more than 0.05 they were regarded as not significant. results a sample of 1364 students from dental colleges in the randomly selected governorates within the study age (18-22 years old) was examined. table (1) shows the general description of the total samples. in this table the age in years categorized into five groups with the age group of 18 years of highly percentages than the others, females constituted 52.5% of the whole sample while the nonsmoking dental students form about 63.6%of both gender, however, 40.2% of the total sample was from the basra university. figure (1) illustrates that the percentage of dental students with low severity of dental caries was higher than that of dental students with high severity of dental caries. table (2) demonstrates the quality of life domains scores according to caries severity where the dmfs ≥ 12 was considered as high severity and the dmfs <12 was considered as low severity. in this table, the mean scores of the four whoqol-bref domains were higher among caries free dental students with highly statistical significance (p˂0.001) among the three types of caries j bagh college dentistry vol. 32(3), september 2020 the impact of 10 severity. however, among caries free dental students, the mean score of psychological domain was lowest. on the other hand, among the dental students with high caries severity, the mean score of physical domain was the lowest compared to other scores (34.91 ± 0.68) followed by mean scores of environment domain (35.97 ± 0.55) and then the mean score of both psychological and social domains were (42.91 ± 0.40, 40.64 ± 0.54 respectively). regarding dental caries and the four whoqol-bref domains, in each domain scores, ds component had the highest contribution to the dmfs followed by the ms component while fs components had the lowest contribution to the index. on the other hand, dmfs showed the lowest mean among the good scores of all the domains and it had the highest mean among the poor type. there were statistical highly significant differences (p˂0.001) among the three scores of four whoqol-bref domains regarding the dmfs and its components, as illustrated in table (3). figure (1): the distribution of dental students according to caries severity 0 100 200 300 400 500 600 700 caries freelow severityhigh severity 295 626 443 21.60 %45.90 %32.50 % no. % table (1): the distribution of the total sample according to the sociodemographic characteristics. sociodemographic characteristics no. % governorate anbar 464 34.0 % mosel 352 25.8 % basrah 548 40.2 % age 18 years 295 21.6 % 19 years 270 19.8 % 20 years 274 20.1 % 21 years 265 19.4 % 22 years 260 19.1 % gender male 648 47.5 % female 716 52.5 % smoking status smoking 497 36.4 % non smoking 867 63.6 % j bagh college dentistry vol. 32(3), september 2020 the impact of 11 *highly significant p≤0.01 table (3): caries experience dmfs and its components (ds, ms, fs) according to quality of life domains scores. whoqol-bref domains caries experience (mean ± se) ds ms fs dmfs physical health poor n= 323 16.29 ± 0.33 10.90 ± 0.30 0.76 ± 0.05 28.86 ± 0.38 fair n= 699 7.07 ± 0.18 4.50 ± 0.16 2.16 ± 0.09 12.25 ± 0.28 good n= 342 1.73 ± 0.26 0.58 ± 0.14 0.18 ± 0.03 2.48 ± 0.40 anova df= 2 f 697.25* 509.40* 225.02* 1137.81* sig. 0.001 0.001 0.001 0.001 psychological poor n= 357 13.40 ± 0.38 8.54 ± 0.32 1.73 ± 0.09 23.34 ± 0.58 fair n= 661 7.79 ± 0.22 5.18 ± 0.19 0.91 ± 0.05 13.74 ± 0.36 good n=346 2.48 ± 0.30 1.13 ± 0.17 0.20 ± 0.03 3.81 ± 0.45 anova df= 2 f 281.16* 202.75* 116.05* 371.51* sig. 0.001 0.001 0.001 0.001 social poor n= 313 12.92 ± 0.39 8.71 ± 0.33 1.62 ± 0.09 22.95 ± 0.61 fair n= 726 8.45 ± 0.23 5.35 ± 0.19 1.01 ± 0.06 14.64 ± 0.37 good n= 325 1.90 ± 0.30 0.78 ± 0.16 0.14 ± 0.03 2.83 ± 0.44 anova df= 2 f 260.40* 215.69* 96.80* 361.48* sig. 0.001 0.001 0.001 0.001 environment poor n= 268 12.38 ± 0.45 7.91 ± 0.38 1.65 ± 0.10 21.62 ± 0.73 fair n= 776 8.83 ± 0.23 5.82 ± 0.19 1.03 ± 0.05 15.52 ± 0.35 good n= 320 1.95 ± 0.29 0.70 ± 0.15 0.15 ± 0.03 2.81 ± 0.43 anova df= 2 f 218.07* 176.72* 92.27* 294.75* sig. 0.001 0.001 0.001 0.001 *highly significant p≤0.01. table (2): quality of life domains score (mean and se) according to caries severity. caries severity whoqol-bref domains (mean ± se) physical psychological social environment caries free n= 350 77.13 ± 0.34 63.88 ± 0.79 68.60 ± 0.93 65.27 ± 0.69 low severity n= 633 59.12 ± 0.38 46.97 ± 0.39 46.13 ± 0.45 43.07 ± 0.57 high severity n= 381 34.91 ± 0.68 42.91 ± 0.40 40.64 ± 0.54 35.97 ± 0.55 anova df= 2 f 1609.46* 393.44* 490.85* 507.28* sig. 0.001 0.001 0.001 0.001 j bagh college dentistry vol. 32(3), september 2020 the impact of 12 discussion dental caries is a disease that is caused by many factors (11). in order to evaluate dental caries, dmfs index was used, which is an arithmetical index that measures the cumulative caries aggression of the individuals (12). however, it seemed that students' dental education affects dmfs components since it was noticed that a decrease in the number of carious lesions was accompanied by an increase in the number of fillings as the students progressed from one academic year to the next (2). this finding shows that as the dental students with low severity (dmfs ˂12) of dental caries in the present study showed the higher percentage (46.4%). this could be explained by many factors affecting the prevalence of dental caries such as the level of education, socioeconomic status or good oral hygiene measures. evaluation of quality of life, including quality of life related to oral health, depends on an individual’s expectations and experiences, which vary according to the social, psychological, socioeconomic, demographic, and other cultural factors (4,13). students with high dmfs had poor quality of life due to the psychological discomfort which is the biggest drivers of poor quality of life among dental students, which was in line with other studies (15-18). therefore, one may assume a similar pattern of quality of life related to oral health exists in young adults in different countries. in the current investigation, a higher dmfs index was associated with low quality of life as the dental caries is multifactorial disease (19) and one of the most important factor that has an effect on it is the socioeconomic status (20,21) that includes social factor, low life style and behavior, low ability for utilization dental services (22,23). so, because of these difficulties and the bad environment, this could lead to less care for the oral hygiene (24). in contrast, swedish and china studies did not find any differences in quality of life among young adults at high caries risk(17,25). nevertheless, japanese university students with a higher dmfs index had lower quality of life (18). at present, the mechanisms of the relationship between dental caries experience and quality of life are unclear. given that physical pain was the most frequently reported, it is assumed that the dental caries experience among the dental students was likely associated with pain in their mouth. public health measures, as well as dental practitioners, should focus on the prevention of dental diseases to decrease dental pain and dmfs index and improve quality of life among young iraqis adults. conclusion clinically-assessed oral health (dmfs index) was found to be a significant predictor of low quality of life among dental students in iraq. public health measures should focus on the prevention of dental caries and the development of strategies to promote oral health specifically among dental students. references 1. kumar s, motwani k, dak n, balasubramanyam g, duraiswamy p, kulkarni s. dental health behaviour in relation to caries status among medical and dental undergraduate students of udaipur district, india. int j dent hyg. 2010; 8:86-94. 2. simat s, mostarcic k, matijevic j, simeon p, grget kr, jukic krmek s. a comparison of oral status of the fourth-year students of various 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quality of life and its relationship with health locus of control among indian dental university students. eur j dent educ. 2008; 12:208-212. 16. gonzales-sullcahuaman ja, ferreira fm, de menezes jv, paiva sm, fraiz fc. oral health-related quality of life among brazilian dental students. acta odontol latinoam. 2013;26:76-83. 17. lu hx, wong m, lo e, mcgrath c. oral health related quality of life among young adults. appl res qual life. 2015; 10:37-47. 18. yamane-takeuchi m, ekuni d, mizutani s, kataoka k, taniguchi-tabata a, azuma t, furuta m, tomofuji t, iwasaki y, morita m. associations among oral health-related quality of life, subjective symptoms, clinical status, and self-rated oral health in japanese university students: a cross-sectional study. bmc oral health. 2016;16: 127. 19. aas ja, griffen al, dardis sr, lee am, olsen i, dewhirst fe, paster b.j. bacteria of dental caries in primary and permanent teeth in children and young adults. j clin microbiol. 2008; 46(4):1407-17. 20. al-azawi la. oral health status and treatment among iraqi five year old kindergarten children and fifteen years old students (a national survey). phd thesis, university of baghdad, collage of dentistry. 2000. 21. abdul-razzaq qr. oral health status among 15 years old school students in suilimania city – iraq. master thesis, college of dentistry, university of baghdad. 2007. 22. pitts n, amaechi b, niederman r, acevedo a, vianna r, ganss c, honkala e. global oral health inequalities: dental caries task group—research agenda. adv dent res. 2011;23(2): 211-220. 23. olusile ao, adeniyi aa, orebanjo o. self-rated oral health status, oral health service utilization, and oral hygiene practices among adult nigerians. bmc oral health. 2014;14:140. 24. world health organization. international statistical classification of diseases and health related problems. geneva: author; 2016 25. oscarson n, kallestal c, lindholm l. a pilot study of the use of oral health-related quality of life measures as an outcome for analysing the impact of caries disease among swedish 19-year-olds. caries res. 2007;41:85-92. :مستخلصال يأخذ تسوس األسنان األولوية القصوى في خدمات صحة الفم التي تخص الفئة الشبابية. لغاية اآلن التوجد دراسة محلية الخلفية: تكشف تأثير جودة الحياة وعالقتها بتسوس األسنان بين طالب طب األسنان.الهدف من الدراسة الحالية :هو لقياس تأثير تسوس األسنان في ثالث محافظات في العراق. األسنان على جودة الحياة بين طالب طب سنة من ثالث محافظات. تم الحصول على معلومات عن 2218طالب طب أسنان بعمر 1364: شملت العينة المواد والطرق جودة الحياة من الطالب بواسطة أستبيان خاص. تم جمع البيانات وتلخيصها وتحليلها أحصائيا. تم قياس تسوس األسنان في الدراسة من منظمة الصحة العالمية. dmfsالحالية بأستخدام مقياس : فيما يخص تسوس األسنان واألنماط األربعة لجودة الحياة فأنه في كل نمط تكون القيمة المتوسطة لالسطح المسوسة اعلى النتيجة قياس تسوس األسنان يظهر أقل معدل قيمة في المقياس تليها القيمة المتوسطة لالسطح المفقودة ثم الممتلئة. من ناحية أخرى فأن م له بين مجموعة جودة الحياة المرتفعة في كل أنماط جودة الحياة ويكون أكبر معدل لتسوس األسنان بين مجموعة جودة الحياة المنخفضة. التسوس. كان لجودة الحياة بين طالب طب األسنان تأثيرعلى تسوس األسنان كما أنها ترتبط أرتباط وثيق مع شدة الخالصة: الكلمات المفتاحية: تجربة نخر االسنان, طالب طب األسنان, جودة الحياة dropbox 10 ansam f 52-59.pdf simplify your life j bagh college dentistry vol. 32(2), june 2020 association between 5 association between anti-cmv igg and salivary levels of il‐6 and tnf-α in chronic periodontitis heba kazhaal mahmood (1), batool hassan al-ghurabi (2) article doi: https://doi.org/10.26477/jbcd.v32i2.2887 abstract background: periodontitis is an infection attributable to multiple infectious; it causes an interrelated cellular and humoral host immune responses. recent reports have indicated that human cytomegalovirus (hcmv) may contribute to pathogenesis of periodontitis. the hcmv can stimulate the release of cytokines from inflammatory and non-inflammatory cells and weaken the periodontal immune defense. this study aimed to reveal the presence of anti-cmv igg, and determine the levels of il‐6 and tnf-α and to correlate the presence of cytomegalovirus (cmv) with cytokines levels. materials and methods: forty patients with chronic periodontitis and 40 healthy control subjects (their age and sex were matched with the patients) were involved in this study. periodontal parameters used in this study included plaque index (pli), gingival index (gi), probing pocket depth (ppd), clinical attachment level (cal) and bleeding on probing (bop). saliva samples were taken from all subjects. elisa was carried out to estimate the levels of anti-cmv igg, il‐6 and tnf-α. statistical tests used involved t-test, mann-whitney, chi-square, fisher exact and spearman's correlation test. results: this study found a significant difference (p<0.05) in the frequency of anti-cmv igg in saliva between patients and controls. the number and percentage of patients group who had positive for anti-cmv igg were 14 (35%), while controls were 5 (12.5%). a significant increase was found in mean of ppd, cal and bop among patients with the positive igg as compared to those patients with the negative igg. in addition, there was a significant elevation in the salivary levels of il‐6 and tnf-α in patients compared with healthy controls. il6 was significantly associated with gi and bop, whereas tnf-α was significantly associated with ppd and cal. on the other hand, there was a significant correlation between tnf-α and anti cmv igg. conclusion: the findings revealed that the significant association between the presence of virus with periodontal parameters and cytokines level in patients group gives additional evidence toward the potential importance of the direct and indirect effects of cmv infection in periodontitis. keywords: periodontitis, anticmv igg, cytokines. (received: 04/04/2020; accepted: 10/05/2020) introduction periodontitis is a chronic infection in tissues backup teeth with various features including the inflammation in gingival tissues, construction of periodontal pockets, connective tissue attachment losing, resorption of alveolar bone, and even losing tooth.(1) it is an advanced, multifactorial disorder related with inflammation. chronic periodontitis is a multifactorial inflammatory disease correlated with dysbiotic dental plaque biofilms and considered a progressive destruction of the tooth‐ supportive structures.(2) the bacterial pathogenesis theory cannot totally explain the clinical features of periodontal diseases only, and the conventional treatments targeting such bacteria have restricted roles in avoiding periodontal diseases.(3) viruses may also play a role in the pathogenesis of periodontal diseases. the herpes virus has been known to be a pathogenic cause for several periodontal diseases since the 1990.(4) in addition, herpes viruses have been associated with periodontal diseases, especially epstein-barr virus (ebv), human cytomegalovirus (hcmv).(4-6) periodontal herpes viral infections can rise and change inflammatory mediator and cytokine responses, (1) assistant lecturer, department of basic science, college of dentistry, university of baghdad. (2) professor, department of basic science, college of dentistry, university of baghdad. corresponding author, hebakazhaal@yahoo.com which can up regulate il-1β and tnf-α gene appearance in monocytes and macrophages.(3,4,7). these host mediators directly or indirectly participate in periodontal tissue damage and specifically in bone resorption.(8) interleukin-6 is well-known as one of the key cytokines of host response to inflammation and tissue damage such as that seen in chronic periodontitis and stimulates bone resorption by itself and in conjunction with other bone-resorbing causes.(9) the tnf-α is very important proinflammatory cytokine released at the site of periodontitis that plays a prominent function in the pathogenesis of periodontitis.(10) the hypothesis of the present study was that herpes virus infection initiates periodontal tissue breakdown and that host immune responses against the herpes virus infection are an important component of the etiopathogenesis of the disease. this study was performed to detect the association between anti-cmv igg and salivary levels of il‐ 6 and tnf-α in chronic periodontitis. materials and methods overall of 40 patients with chronic periodontitis (cp) (age range from 30-55 years) were studied, in parallel with 40 actually healthy volunteers (control) of a similar age range. the diagnosis of cp was done according to the criteria of american academy of periodontology (aap).(11) clinical periodontal examination was performed for all subjects by the same examiner. periodontal https://doi.org/10.26477/jbcd.v32i2.2887 j bagh college dentistry vol. 32(2), june 2020 association between 6 parameters used in this study were pli, gi, ppd, cal and bop.(12-14) four surfaces of each tooth were assessed. saliva samples were collected from cp patients and healthy control groups to evaluate salivary level of anti-cmv igg, il‐6 and tnf-α (bioactive diagnostica-germany, diclone-france, komabiotech-korea) respectively. all participants were instructed not to eat or drink (except having water) at least 1 hour prior to donation of saliva, the subject should sit in a relaxed position and samples containing blood should be discarded. saliva was collected between 9-12 am. after the subject rinses his mouth several times by sterilized water and then waits for 1-2 minutes for water clearance, 5ml of whole unstimulated saliva was collected into polyethylene tubes. three ml of saliva was centrifuged at (3000 rpm) for 10 minutes and the resulting supernatant was stored at -40˚c in eppendorf tubes until assayed. each of the subjects obtained detailed information concerning the nature of the study and the procedures included, and their informed consent was acquired on a form approved by ethical committee of college of dentistry in university of baghdad. statistical analysis was accomplished using computerized statistical analysis spss software version 24 (statistical package for social science). semirnov-kolmogorov test was used to test the normality of distribution of the data. student t-test was used for parametric data, and mann-whitney test for non-parametric data to test the statistical mean difference between two groups. association between the different parameters was calculated by the spearman test and p-values of p<0.05 were considered significant. results the demographic data of subjects (patients and controls) included in this study are demonstrated in table (1). the mean age of patients was (45.00±1.29) years, and (42.65±1.15) years for control group. the male:female number of the patients group was (19/21) and in the control group was (11/29). there were no significant differences (p>0.05) in the age and gender among the two study groups. the variances in periodontal parameters between patients and controls are presented in table (2). table 1: demographic characteristics of patients and controls. characteristics patients group n=40 control group n=40 t-test p-value age range 30-55 30-50 0.170ns mean 45.00 42.65 se 1.29 1.15 sd 8.19 7.30 gender male no. 19 11 % 47.5% 27.5 % female no. 21 29 0.646ns % 52.5% 72.5 % ns: non–significant, sd: standard deviation, se: standard error, no. : number, %: percentage table 2: clinical periodontal parameters in patients and controls. parameters mean ± se patients group n=40 control group n=40 t-test p-value pli 1.24 ± 0.07 0.98 ± 0.07 0. 01** gi 1.31 ± 0.06 0.47 ± 0.07 0.001** ppd (mm) 4.50± 0.57 0.0 0.0001** cal(mm) 3.66 ± 0.19 0.0 0.0001** bop (%) 87.5% 37.5% 0.0001** highly significant;**: pli: plaque index; gi: gingival index; ppd: probing pocket depth: cal: clinical attachment level; bop: bleeding on probing; se: standard error as seen in table (3) the number and percentage of patients group who had positive anti-cmv igg was 14 (35%), while for controls group was 5 (12.5%). regarding the correlation between the presence of anti-cmv igg and periodontal parameters in patients group, the current results revealed that there is significant increase in mean levels of ppd, cal and bop among patients with the positive igg (5.13 ± 0.42, 4.092 ±0.320 and 74.928 ±11.391) as compared to those patients with the negative igg (4.25± 0.47, 3.067±0.285 and 45.538 ±7.819), table (4). j bagh college dentistry vol. 32(2), june 2020 association between 7 table 3: prevalence of anti-cmv igg antibodies in saliva of patients and controls. patients group n=40 control group n=40 t-test p-value anti-cmv-igg frequency percentage frequency percentage positive 14 35% 5 12.5% 0.033* negative 26 65% 35 87.5% table 4: association between the presence of anti-cmv igg iu/ml and clinical periodontal parameters. periodontal parameters anti-cmv igg t-test p-value cmv positive n=14 cmv negative n=26 mean ± se mean ± se pli 1.207±0.1269 1.273±0.094 0.343ns gi 1.435±0.131 1.294±0.079 0.167 ns ppd (mm) 5.13 ± 0.42 4.25± 0.47 0.005** cal 4.092 ±0.320 3.067±0.285 0.016* bop (%) 74.928 ±11.391 45.538 ±7.819 0.0181* the current results found that there was a significant elevation in the mean rank salivary levels of il-6 and tnf-α among patients with chronic periodontitis when matched to healthy controls, (p˂ 0.01), table (5). as observed in table (6), there is a significant positive association between il-6 and each of gi and bop (r=0.418, p=0.024 and r=0.334, p=0.034) respectively, otherwise, there is a significant positive association between tnf-α and each of ppd and cal (r=0.402, p=0.029 and r=0.398, p=0.031). table 5: salivary levels of il-6 and tnf-α (pg/ml) in patient and control groups. salivary il-6 patients group n=40 control group n=40 mann-whitney p-value minimum 2.84 0.0 0.0001** maximum 80.66 44.12 mean rank 47.86 25.31 median 9.37 4.41 salivary tnf-α 0.017** minimum 7.8 0.0 maximum 250 150 mean rank 42.96 30.04 median 62 31 table 6: spearman’s correlation between salivary il-6 and tnf-α levels and clinical periodontal parameters in patients. periodontal parameters salivary il-6 patients group n=40 correlation r mann-whitney p-value pli 0.113 0.485 gi 0.418 0.024* ppd(mm) 0.016 0.918 cal 0.010 0.949 bop 0.334 0.034* salivary tnf-α j bagh college dentistry vol. 32(2), june 2020 association between 8 correlation (r) mann-whitney p-value pli 0.163 0.313 gi 0.042 0.793 ppd 0.402 0.029* cal 0.398 0.031* bop 0.072 0.655 on the other hand, there is non-significant increase (p>0.05) in the mean rank of il-6 in patients with the positive igg (18.86pg/ml) than that in patients with the negative igg (21.38 pg/ml), also nonsignificant increase (p>0.05) in mean rank of tnfα was found patients with the positive igg (22.36pg/ml) than that in patients with the negative igg (19.5pg/ml), table (7). table 7: comparison between positive and negative igg patients for il-6 and tnf-α levels salivary il-6 level anti-cmv igg mannwhitney p-value cmv positive n=14 cmv negative n=26 minimum 3.497 2.848 0.136ns maximum 27.454 80.669 mean rank 18.86 21.38 median 11.35 8.72 salivary tnf-α level 0.122ns minimum 12.586 7.8 maximum 250 250 mean rank 22.36 19.5 median 62 62 discussion human cmv has frequently been associated with periodontal disease. the virus affects periodontal monocytes/macrophages and t-lymphocytes, and reactivation of cmv in periodontitis lesions tends to be correlated with progressive periodontal disease.(15) several studies have reported associations between the presence of hcmv and periodontal diseases.(5,16,17) in this study the frequency of anti-cmv igg was 14 (35%) in patients, and 5 (12.5%) for healthy controls with significant differences between patients and controls. other results reported by esfahanian and colleagues also showed that there were significant differences in mean igg between the two groups.(18) similarly, a previous iraqi study conducted by alalousi in (2013) (19) to investigate the frequency of anti-cmv igg in saliva by elisa in 35 periodontitis patients and 18 healthy controls revealed that the frequency of cmv in chronic periodontitis patients was significantly higher when compared to healthy control group, and found that the mean salivary level of hcmv igg was significantly higher in patients with periodontitis as compared to those of healthy control group. so the study concluded that the frequency of hcmv in saliva of chronic periodontitis patients could have a crucial role in the development of this disease. in contrast with this result, a previous study conducted by watanabe et al. (2007)(20) showed no statistical correlation between hcmv and periodontitis. this variation in the frequency detection of cmv may be attributed to sample size, type of sample and selection of the subjects. the results of the present study revealed that there is a significant correlation between clinical parameters (ppd, cal and bop) and the presence of cmv. there is significant increase in mean levels of ppd, cal and bop among patients with the positive igg as compared to those patients with the negative igg. this result is in accordance with the observations of the previous study conducted by gaekwad and gujjari (2012) (21) who found that the presence of virus was correlated with the measurements of ppd and the cal. the higher ppd in cmv positive sites indicates that this virus might have helped specific bacterial colonization leading to greater disease severity.(22) furthermore, some studies (16, 23, 24) also compared clinical parameters with virus isolation and found statistically significant association in terms of pi and gi. however, chalabi et al., 2008(17) and chalabi et al., 2010(25) showed a relation between human cmv and periodontitis. conversely ling et al., (2004) (26) compared the disease severity in terms of clinical parameters (gi, pi, cal and pd) with virus isolation and revealed that there was no statistically significant association between the presence of cmv and any of the clinical parameters. similarly, a study done by rupali et al., (2012) (22) showed no significant association between the presence of virus and cal. interleukin-6 is one of the important mediators of the inflammatory response in several inflammatory diseases, including periodontitis.(27) results of the present study showed that the salivary il-6 level was significantly elevated in chronic periodontitis subjects as compared to controls. these data are compatible with previous findings (28-30) that showed significant elevation in level of salivary il-6 among patients as compared to healthy controls. in addition, mccauley and colleagues j bagh college dentistry vol. 32(2), june 2020 association between 9 pointed out that elevated levels of il-6 have been shown to be induced by periodontal pathogens and are correlated with the continuous tissue destruction observed in periodontitis.(31) in consistent with this result, husniah batool et al. (2018)(32) found that the level of salivary il-6 was significantly elevated in calculus associated chronic periodontitis patients as compared to healthy controls and these levels elevated with the progression of chronic periodontitis. so they concluded that salivary level of il-6 may assist in the sub-categorization of chronic periodontitis. on the other hand, these findings disagree with those of dhruva et al., (2009)(33) who demonstrated no significant differences between chronic periodontitis and control group according to salivary levels of il-6. in addition, teles et al., (2014)(34) demonstrated in their study that the levels of il-6 were higher in patients than the healthy individuals but statistically not significant and stated that the range of il-6 concentration in saliva was often quite variable. concerning the correlation between il-6 level and periodontal parameters, this study found significant correlation between salivary il-6 and each of gi and bop. this result was consistent with javed et al., (2014)(29) who proved that there is a significant correlation between the level of il6 in saliva and the clinical parameters such as ppd, cal and bop, they found an increase in the salivary il-6 levels as the severity of the periodontal disease increased. likewise, hussein (2017)(35) who used serum sample showed that there was a significant strong positive correlation between serum il-6 levels with pli, gi, ppd and cal. furthermore, noh et al., (2013)(36) indicated that il-6 may promote the degeneration of inflamed periodontal tissues. tnf-α is a pro-inflammatory cytokine that has an effect in the activation of inflammatory leukocytes, modification of vascular permeability and induction of bone resorption.(37) the current study revealed high level of salivary tnf-α in patients group than that in controls group. this agrees with the study conducted by varghese et al., (2015) (37) and ehsan et al., (2017) (38) who noticed that tnf-α value in chronic periodontitis patients was significantly higher than in control subjects. further, another study assessed the salivary activity rates of tnf-α and stated that the level of this cytokine was higher in patients than healthy individuals, and suggested that tnfα level can be used as biomarkers to diagnose disease.(39) in contrast, these results were at variance with other studies (40,41) that showed no significant difference in level of tnf-α between the patients and controls. teles et al., (2014) (34) reported a lack of association between the levels of salivary biomarkers, including tnf-α and periodontal disease status. they attributed their result to the inhibition of cytokines in the saliva by the putative inhibitors present in the whole saliva. another interesting finding in this study was the significant positive association of salivary tnf-α with each of ppd and cal. correspondingly, a previous iraqi study revealed a significant positive association of tnf-α level with gi, ppd and cal.(42) besides, kurtis et al., 2005 (43) also reported a positive correlation between salivary tnf-α levels and clinical parameters such as ppd, cal, pi and gi in samples of patients with chronic and aggressive periodontitis. unlike the current result, varghese and his colleagues found nonsignificant correlation between salivary tnf-α level and the clinical parameters possibly due to the extensive dilution of these markers in the saliva, thereby failing to reflect the minor variations in the clinical parameters.(37) interestingly, positive correlation between the levels of the proinflammatory cytokines (il-6 and tnf-α) and the disease severity in the present study was mightily confirm the hypothesis that these cytokines are likely to be involved in the pathogenesis of periodontitis. kurtis et al. (43) also reported a positive correlation between salivary tnf-α levels and clinical parameters such as pd, cal, pi, and gi in gcf samples of patients with chronic and aggressive periodontitis. the findings of the present study found that there is no association between il-6 and tnf-α level with the presence of cmv. this was in agreement with another study of jakovljevic et al., (2018) (44) who stated that only 4 out of 54 hcmv (13.5%) patients showed increased viral copy numbers and there was no significant correlation between the levels of pro-inflammatory cytokines (il-1β, il-6 and tnf-α) and viral copy numbers. therefore they suggested that low viral loads point to a relatively rare occurrence of active hcmv infection in his samples and latent hcmv infection does not enhance the production of investigated pro-inflammatory cytokines. this result disagrees with botero et al., (2008) who disclose that hcmv infection in gingival fibroblasts up-regulated the production of proinflammatory-related cytokines and chemokines. also the expression of il-1β and tnf-α was increased both in vitro and in specimens from hcmv-positive subjects with periodontitis. thus it was concluded that overproduction of proinflammatory cytokines as a result of viral infection should be considered an important https://www.hindawi.com/73742320/ https://doi.org/10.4103%2f0976-237x.166816 https://doi.org/10.4103%2f0976-237x.166816 j bagh college dentistry vol. 32(2), june 2020 association between 10 pathogenic mechanism linking hcmv to periodontitis in vivo.(45) it is worthy to mention that cmv infects periodontal macrophages and t-cells and elicits a release of pro-inflammatory cytokines which play an important role in the host defense against the virus, but they also have the potential to induce alveolar bone resorption and loss of periodontal ligament. over-production of proinflammatory cytokines occurs due to chronic stimulation of tlr9 by herpes virus dna which may lead to tissue destruction.(6) a limitation of the current study is the study of only one microorganism (virus), as multiple microorganisms are involved in the pathogenesis of periodontitis. moreover, other proinflammatory and anti-inflammatory cytokines need to be investigated for an association with cmv in periodontitis. conclusions the presence of hcmv was documented through detection of hcmv-specific antibodies. the significant correlation between the presence of virus with periodontal parameters (ppd, cal and bop) gives additional evidence toward the potential importance of the direct and indirect effects of cmv infection in periodontitis. more clinical and longitudinal analyses with larger samples are required to evaluate the role of cmv in different periodontal diseases. further investigations using other different samples such as gingival tissues and gcf are needful. conflict of interest: none. references 1. mulawarmanti d, parisihni k, widyastuti. the effect of sticopus 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"mediators of periodontal osseous destruction and remodeling. principles and implications for diagnosis and therapy". j periodontol. 2002;73:1377–91. 32. batool h, nadeem a, kashif m, shahzad f, tahir r, afzal n. salivary levels of il-6 and il-17 could be an indicator of disease severity in patients with calculus associated chronic periodontitis. biomed res inter. 2018, article id 8531961, 5. 33. gani dk, lakshmi d, krishnan r, emmadi p. evaluation of c-reactive protein and interleukin-6 in the peripheral blood of patients with chronic periodontitis. j ind soc periodontol. 2009;13(2):69–74. 34. teles rp, likhari v, socransky ss, haffajee ad. salivary cytokine levels in subjects with chronic periodontitis and in periodontally healthy individuals: a cross-sectional study. djas 2(iii). 2014;145-149. 35. hussein o. evaluation of serum interleukin-1𝛽 and interleukin-6 levels in patients with chronic periodontitis in relation to atherosclerotic heart disease. a thesis submitted to the college of dentistry/university of baghdad for the msc degree in periodontics. 2017. 36. noh mk, min jh, kim sl, park kh, kim d, hyun, kim h, park yg. assessment of il-6, il-8 and tnf-α levels in the gingival tissue of patients with periodontitis. exp ther med. 2013;15: 847-851. 37. varghese ss, thomas h, jayakumar nd, sankari m, lakshmanan r. estimation of salivary tumor necrosis factor-alpha in chronic and aggressive periodontitis patients. contemp clin dent. 2015; 6:152-156 38. ehsan b, gamel nt, hashim as, gismalla bg. salivary tnfα levels in groups of subjects with rheumatoid arthritis and chronic periodontitis. bmc research notes. 2017;10:34. 39. geng w, ying-hui t, sheng-gen s. expression of il-6 and tnf-α activities in saliva of chronic periodontitic patients. chin j conserv dent. 2009;5:11. 40. ide m, mcpartlin d, coward p, crook m, lumb p, wilson r. effect of treatment of chronic periodontitis on levels of serum markers of acute-phase inflammatory and vascular responses. j clin periodontol. 2003;30:334–340. 41. suzuki i, shimada y, tai h, komatsu y, tanaka a, yoshie h. effects of treatment on soluble tumor necrosis factor receptor type 1 and 2 in chronic periodontitis. j clin periodontol. 2008; 35(11):961-8 . 42. fadil z, al-ghurabi b. study the role of pro-and antiinflammatory cytokines in iraqi chronic periodontitis patients. j bagh coll dent. 2012;24:164-9. 43. kurtis b, tuter g, cem u, akdemir p, erhan f, belgin b. gingival crevicular fluid levels of monocyte chemoattractant protein-1 and tumor necrosis factor alpha in patients with chronic and aggressive periodontitis. j periodontol. 2005;76:1849-55. 44. jakovljevic a, knezevic a, nikolic n, soldatovic i, jovanovic t, milasin j, andric m. herpesviruses viral loads and levels of proinflammatory cytokines in apical periodontitis. oral dis. 2018;24(5):840-846. 45. botero j, contreras a, beatriz p. profiling of inflammatory cytokines produced by gingival fibroblasts after hcmv infection. oral microbiol immunol. 2008;23:291-8. الخالصة الخلفية: التهاب اللثة هو مرض يعزى إلى أسباب معدية متعددة واالستجابات المناعية الخلوية والخلطية المترابطة. أشارت التقارير تحفيز إطالق hcmv( قد يساهم في التسبب في التهاب اللثة. يمكن لـ hcmvاألخيرة إلى أن الفيروس المضخم للخاليا البشرية ) السيتوكينات من الخاليا االلتهابية وغير االلتهابية وإضعاف الدفاع المناعي اللثوي. هدفت هذه الدراسة إلى الكشف عن وجود مضاد لـ cmv igg تويات ، وتحديد مسil-6 وtnf-α ( وربط وجود الفيروس المضخم للخالياcmv.بمستويات السيتوكينات ) شخًصا متطوعا من االصحاء )تم مطابقة 40المواد والطرق: شارك في هذه الدراسة أربعون مريًضا مصابًا بالتهاب اللثة المزمن و ( gi( ، ومؤشر اللثة )pliدمة في البحث الحالي مؤشر البالك ) أعمارهم وجنسهم مع المرضى(. تشمل مؤشرات التهاب اللثة المستخ (. تم أخذ عينات اللعاب من bop( والنزيف عند الفحص )cal( ، ومستوى فقدان االنسجه الرابطه )ppd، وعمق جيب التحقيق ) و عامل 6 -االنترلوكينو cmv iggلتقدير مستويات مضاد elisaجميع االشخاص. تم إجراء الفحص الناعي المرتبط باالنزيم بالضبط ، fisher، و chi-square، و man-whitney، و tنخر الورم الفا. شملت االختبارات اإلحصائية المستخدمة اختبار . spearmanواختبار ارتباط في اللعاب بين المرضى واالصحاء. كان cmv igg( في تواتر مضاد p <0.05النتائج: وجدت هذه الدراسة أن هناك فرقا معنويا ) ٪( ، بينما كانت لمجموعة االصحاء 35) igg 14عدد ونسبة مجموعة المرضى الذين لديهم إيجابية لمضاد الفيروس المضخم للخاليا ي مقارنة اإليجاب iggبين المرضى الذين يعانون من bopو calو ppd٪(. وجدت هذه الدراسة زيادة كبيرة في متوسط 12.5) 5 في tnf-αو il6السلبي. باإلضافة إلى ذلك ، هناك ارتفاع كبير في مستويات اللعاب من iggمع المرضى الذين يعانون من ppdبشكل كبير بـ tnf-α، في حين ارتبط bopو giبشكل كبير بالمؤشر il ‐ 6المرضى مقارنة باالشخاص االصحاء. يرتبط .cmv iggومضاد لـ tnf-αاك ارتباط كبير بين . من ناحية أخرى ، هن calو االستنجانات: كشفت النتائج أن االرتباط الهام بين وجود الفيروس مع مؤشرات التهاب اللثة ومستوى السيتوكينات في مجموعة المرضى يا في التهاب اللثة. يعطي أدلة إضافية على األهمية المحتملة لآلثار المباشرة وغير المباشرة لعدوى الفيروس المضخم للخال https://www.hindawi.com/73742320/ https://www.hindawi.com/37986729/ https://www.hindawi.com/74932362/ https://www.hindawi.com/57354198/ https://www.hindawi.com/39812763/ https://www.hindawi.com/36956174/ https://doi.org/10.4103%2f0976-237x.166816 https://doi.org/10.4103%2f0976-237x.166816 https://doi.org/10.4103%2f0976-237x.166816 https://www.researchgate.net/profile/javier_botero2?_sg=5fljjb3younlhfchevz-nzwtgw9ucid648wv5vjxb_oko_alalhke7dmctdyuq-qqtwg3sk.qffhhtnqpdeibts2kjzoqjcdpo-vxvrtrc_-mvdpbrcqqppyeugktbgiywa-7hgenzvhduuy47rwrc1mpajmua https://www.researchgate.net/profile/adolfo_contreras?_sg=5fljjb3younlhfchevz-nzwtgw9ucid648wv5vjxb_oko_alalhke7dmctdyuq-qqtwg3sk.qffhhtnqpdeibts2kjzoqjcdpo-vxvrtrc_-mvdpbrcqqppyeugktbgiywa-7hgenzvhduuy47rwrc1mpajmua https://www.researchgate.net/profile/parra_beatriz?_sg=5fljjb3younlhfchevz-nzwtgw9ucid648wv5vjxb_oko_alalhke7dmctdyuq-qqtwg3sk.qffhhtnqpdeibts2kjzoqjcdpo-vxvrtrc_-mvdpbrcqqppyeugktbgiywa-7hgenzvhduuy47rwrc1mpajmua dropbox 02 ahmed 5-11 .pdf simplify your life 22. ghufran f.doc j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry129 relationship of maximum bite force with craniofacial morphology, body mass and height in an iraqi adults with different types of malocclusion ghufran d. awad, b.d.s. (1) ausama a. al – mulla, b.d.s., dr.d.sc. (2) abstract background: information concerning the maximum bite force in human population is important to clinical orthodontics. additionally, the influence of bite force on the vertical stability of any treatment result is important. the new position of the dentition should be compatible with the dynamics of the muscular and occlusal forces in all planes. this study was conducted to 1) to measure and compare maximum bite force, body height and weight among normal occlusion and malocclusion groups (cl i,cl ii,cl iii) in both gender 2) to evaluate the correlation between bite force and craniofacial morphology, body height and weight. materials and methods: the sample consists of 100 iraqi adult subjects aged 18-25 years. it was classified in to four groups: cl i normal occlusion, cl i malocclusion, cl ii malocclusion, and cl iii malocclusion according to(skeletal) the value of anb angle and (dental)the angle classification. each group consist of 25 (13 male, 12 female), maximum bite force was measured by a digital device (gm10, naganokeiki, japan) by putting the sensor part of occlusal force meter on first molar region, body height and weight were measured by using the length and weight measuring standard (tanita, 2008) and craniofacial measurements were achieved by analysis of lateral cephalometric radiograph results: the highest mean value of maximum bite force was found in normal occlusion followed by class ii malocclusion and then class i malocclusion and the lowest value was found in class iii malocclusion, class i skeletal relationship (cl i normal occlusion & cl i malocclusion group) had larger values of body weight when compared with skeletal class ii& class iii .regarding the gender, mean values of maximum bite force and body height are higher in male than female in normal occlusion and malocclusion groups, there is a positive correlation between maximum bite force and body height and weight in normal occlusion and class i malocclusion ,there is a positive correlation between maximum bite force and palatal plane, ramus plane, mandibular plane, posterior facial height, cranial base, dentoalveolar height, while there is a negative correlation with anterior facial height, gonial angle, sn-mp˚,ppmp&sn-pp˚ angles. conclusion: the normal occlusion group had larger values of bite force than malocclusion group,the maximum bite force, body height is gender related, larger body build up was usually associated with larger bite force in class i skeletal relationship, individuals with characteristics of larger maxilla ,larger mandible, larger cranial base ,short anterior facial height long posterior facial height, flat mandibular plane had the largest value of bite force. key words: bite force, craniofacial morphology. (j bagh coll dentistry 2013; 25(1):129-138). introduction clinical and animal experiments have demonstrated the role of masticatory muscle function in normal and abnormal dentofacial development (1). the masticatory muscles also play an important role in the treatment of skeletal discrepancies by the use of functional orthopedic appliances. this is due to the tension they exert on the teeth and the bone structure, either by muscle contraction based on reflex mechanisms or through their viscoelastic properties (2). the characteristics and the functional behavior of masticatory muscles are of great importance in the field of orthodontics. masticatory muscle strength can be evaluated by different methods and is influenced by many variables. one such method is the assessment of maximum voluntary bite force (mvbf). bite force can be defined as the forces applied by the masticatory muscles in dental occlusion (3). (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontic, college of dentistry, university of baghdad. bite force is the result of the coordination between different components of the masticatory system which includes muscles, bones and teeth. many studies have reported the relationship between bite force and craniofacial morphology based on variables measured from lateral cephalograms (4,5), larger occlusal forces was associated with larger maxilla,larger mandible,larger posterior cranial base and small gonial angle (6,7,8). bite force also varies with different facial profiles. it is greater in adults with a rectangular craniofacial morphology and skeletal deep bite than in those who have a long face and open bite (9,10). many studies had investigated the association of occlusal forces with weight, height, and body mass index (11,12,13),some studies show a positive correlation between bite force and body height and weight (10),while others show no correlation (13,14) masticatory performance has been shown to be decreased in subjects with malocclusions when compared with those with a normal occlusion (15,16). with regard to general muscle strength, j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry130 this has been shown to be as strong and as large in females as in males until puberty (2). it is believed that gender-related bite force differences develop during the post-pubertal period in association with greater muscle development influenced by androgenic steroids in males (1,2) and that a decline in occlusal force is associated with masticatory performance with ageing (17). objective information concerning the stabilization of mvbf in the human dentition would be beneficial for both investigators and practitioners. materials and methods the sample included dental students of the college of dentistry, university of baghdad, and patients attending the orthodontic department in the college of dentistry, university of baghdad at age range from 18-25 years. the distribution of the sample among the different classes was achieved by clinical (molar relation) and radiographical (anb angle) examination. the total number was 100 subjects, 25 for each different class with subdivision (13 male and 12 female) criteria of the sample there are general criteria must be present in total sample: 1all subjects were iraqis aged 18-25 years. 2no history of tmj problem like clicking or creptus, tenderness, muscle or jaw pain or discomfort during mandibular movements when talking or eating. 3no history of previous orthodontic treatment and orthognathic surgery. 4no history of bruxism or clenching. 5full set of normal permanent teeth in both jaws excluding third molars 6no massive carious lesion and filling restoration. 7no congenital defect or deformed teeth. 8subjects with facial asymmetry or cross bite were excluded. the specifications of the four sample groups are outlined below: icl. i normal occlusion: they were selected according to following criteria: 1all subjects have skeletal cl. i, the relationship was examined radiographically by measuring anb angle (2-4 degrees). 2bilateral class i molar relationships, molar relationship based on angle's classification, in which the mesiobuccal cusp of the maxillary first permanent molar occludes with groove present between buccal and middle cusps of the mandibular first permanent molar (18). 3normal overbite and overjet (2-4 mm) (19) 4no spacing, no shifting and well aligned teeth iicl. i malocclusion: they were selected according to the same criteria of cl. i normal occlusion except that the patients have crowding in the upper arch and lower arch, spacing, malalignment, shifting in dental midline (not more than 1-2mm). iiiclass ii malocclusion group: they were selected according to following criteria: 1all subjects have skeletal cl ii.relationship examined radiographically by measuring anb angle (5-9 degrees). 2all subjects have molar class ii in which the mesiobuccal cusp of the maxillary first permanent molar occludes mesial (about full cusp or more) to the groove present between buccal and middle cusps of the mandibular first permanent molar (18). 3the amount of the overjet more than normal value that may reach to 8 mm. 4the subjects with class ii division 2 were excluded. ivclass iii malocclusion group: they were selected according to the following criteria: 1all subjects have skeletal cl iii., the relationship was examined radiographically by measuring anb angle ( 5 to –1 degrees). 2all subjects have molar class iii in which the mesiobuccal cusp of the maxillary first permanent molar occludes distal (about full cusp or more) to the groove present between buccal and middle cusps of the mandibular first permanent molar (18). 3there is an edge to edge incisal relationship and a reverse overjet. bite force measuring device as illustrated in (figure 1) the device consisted of hydraulic pressure gauge & a biting element made of a vinyl material encased in a plastic tube called disposable occlusal cap that will be replaced for each subject. the accuracy of this occlusal force gauge has been previously confirmed (20). the specifications of this device are: aforce range: 0 – 1000 n. baccuracy: ±1 n. cweight: about 70 g. dsize: 195 (l) x 29 (w) x 18(h) mm. the measurement ofmaximum bite force as illustrated in (figure2) the maximum bite force was recorded in the first molar region, using a portable occlusal force gauge (gm10; naganokeiki company, tokyo, japan),by putting the sensor part of the device on the first molar region and the participant was asked to bite firmly for a few seconds as much as he/she j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry131 can, then the bite force was calculated in newton and displayed digitally this bite measurement was repeated three times for each side in alternating order with 2-3 minutes interval between records, and the highest value was registered for each side . figure 1: occlusal force-meter gm10 figure 2: maximum bite force registration (1st molar region) figure 3: measurement of the body height and weight the measurement of body height and weight: as illustrated in (figure3) for each subject, the height and weight were recorded. the height in centimeters and weight in kilograms by using the length and weight measuring standard (tanita 2008) the cephalometric landmarks identification and measurements procedures after the molar classification was checked during clinical examination, the sagittal skeletal relation (anb) was determined by taking lateral cephalometric radiograph. every lateral cephalometric radiograph was analyzed by autocad program (2012) to calculate angular and linear measurements. the radiographs were classified depended on the sagittal skeletal relation according to (21) into: 1. skeletal class i relation: 2° ≤ anb ≤ 4° 2. skeletal class ii relation: anb > 4°. 3. skeletal class iii relation: anb < 2°. the cephalometric planes and angles (figure4): 1-sella-nasion plane (s-n): it is the anteroposterior extent of the anterior cranial base (22). 2-sella –articulare plane (s-ar): formed by a line joining sella turcica and articulare (22). 3-ramus plane (ar-go): a line tangent to the posterior border of the mandibular ramus from articulare to gonion. (23). 4-mandibular plane (go-me): formed by a line joining gonion and menton (23). 5-lower anterior facial height (lafh): it is measured from ans to menton (24). 6-upper anterior facial height (uafh): it is measured from nasion to ans (25). 7-posterior facial height (pfh): it measured from s to go (22). 8-palatal plane (pp): a plane joining between anterior nasal spine and posterior nasal spine (23). 9u6 /pp: the distance from tip of mesial cusp of maxillary first molar to palatal plane (7). 10l6/mp: the distance from tip of mesial cusp of mandibular first molar to mandibular plane (7). 11total anterior facial height (afh): it measured from nasion to menton (22). cephalometric angles: 1-anb angle: difference between sna and snb angle which represent anteroposterior position of maxilla in relation to mandible, the normal range is from 2-4 degrees (22). 2saddle angle (n-s-ar): is the angle between the anterior and posterior cranial base (22). 3-gonial angle(ar-go-me)angle: is an expression for the form of the mandible, with reference to the relation between body and ramus (22). 4-sn-mandibular plane angle (sn-mp angle): this angle gives the inclination of the mandible to the anterior cranial base (22), its normal range from 28-36.5 degree. 5. basal plane angle (pp-mp): this defines the angle of inclination of the mandible to the maxillary base (22). 6-sn-maxillary plane angle (sn-pp angle): this angle gives the inclination of the maxilla to the anterior cranial base (22). j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry132 figure 4: cephalometric angular and linear measurement results tables 1,2,3 and 4 show the descriptive statistics, genders difference of the maximum bite force, body height and weight in normal occlusion and malocclusion groups, male exhibit larger values of bite force than female with a high significant difference in normal occlusion , and cl iii malocclusion ,a significant difference in cl i malocclusion and cl ii malocclusion. while for body height, male exhibit larger values than female with a very high significant difference in normal occlusion and malocclusion groups, for body weight male exhibit larger values than female with a very high significant difference in normal occlusion group only. table 5 shows the descriptive statistics, classes difference of the maximum bite force, body height and weight for the total sample, the highest value of maximum bite force was found in normal occlusion group followed by class ii malocclusion and then class i malocclusion and the lowest value was found in class iii malocclusion with a very high significant difference while for body weight, the highest mean value was found in class i skeletal relationship (cl i normal occlusion & cl i malocclusion group) when compared with skeletal class ii& class iii relationship with a high significant difference. table 6 shows that there is a moderate positive correlation between maximum bite force and body height and weight in normal occlusion and class i malocclusion(the correlation with height was stronger than the correlation with weight) while there was a weak or no correlation in class ii and class iii malocclusion group. table 6 in normal occlusion group, show that there was a correlation between maximum bite force and linear measurement, the correlation is positive with (length of maxillary base anspns, ramus plane ar-go, mandibular plane gome, posterior facial height s-go, posterior& anterior cranial base s-ar, s-n, dentoalveolar height u6/pp,l6/mp, while the correlation is negative with lower anterior facial height ansme, there is a negative correlation with rotation angles sn-mp˚,pp-mp&sn-pp˚ angles while there is a weak correlation with non rotation angles n-s-ar˚. table 7 in class ii malocclusion group, show that there was a positive correlation between maximum bite force and mandibular plane gome. table 8 in class iii malocclusion group, show that there is a positive correlation between maximum bite force and ramus plane ar-go, posterior facial height s-go, posterior cranial base s-ar, anterior cranial base s-n, lower dentoalveolar height l6/mp and a negative correlation with anterior facial height n-me. discussion bite force, body structure in both genders for bite force, the results indicated that the bite force is gender related; all readings showed that the males exhibit higher values of maximum bite force than the females in normal occlusion and malocclusion groups and this could be explained by 1) hormonal difference (2) 2) anatomical differences(26) 3) larger dental size and larger physical strength in male (27,28). for body height, males exhibit higher values of height than the females in normal occlusion and malocclusion groups, while for body weight males exhibit higher values of than the females in normal occlusion group and this could be explained by delaying action of y chromosome which allowing the males to grow over a longer period of time than females (29). bite force, body structure in different classes for bite force, the highest mean value of bite force was found in normal occlusion group followed by class ii malocclusion and then class i malocclusion and the lowest value was found in class iii malocclusion this could be explained by 1) the variation in craniofacial morphology and jaws biomechanics. 2) the difference in size and orientation of jaws elevator muscles. 3) the variation in amount of occlusal contact area. for body weight, class i skeletal relationship (cl i normal occlusion & cl i malocclusion group) had larger value of body weight when compared with skeletal class ii& class iii relationship and this could be explained by the patients with cl ii & cl iii skeletal relationship had certain degree of masticatory handicap, those patients had difficulty in chewing their food this in turn will affect on quantity of food intake j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry133 resulting in lower values of body weight in cl ii & cl iii skeletal relationship between bite force and body height and weight there is a moderate positive correlation between maximum bite force and body height and weight in normal occlusion and class i malocclusion(the correlation with height was stronger than the correlation with weight) this could be explained by that the larger overall body build up is frequently associated with larger maxilla ,mandible and /or thicker masticatory muscles which result in higher values of bite force while there was a weak or no correlation in class ii and class iii malocclusion group. relationship between bite force and craniofacial morphology in normal occlusion group, there is a positive correlation between maximum bite force and (length of maxillary base ans-pns, upper dentoalveolar height u6/pp this could be explained by that the increase in antero-posterior length of maxillary base and /or increase in vertical length of upper dentoalveolar structure result in larger size of maxilla which in turn produce higher values of bite force. there is a positive correlation between bite force and ramus plane ar-go, mandibular plane go-me, lower dentoalveolar heightl6/mp, posterior& anterior cranial base s-ar, s-n this indicating that larger size of mandible and cranial base resulting in larger values of bite force, also there is a positive correlation with posterior facial height s-go, while the correlation is negative with lower anterior facial height ans-me ,snmp˚, pp-mp&sn-pp˚ angles, individuals with larger values of go-me, s-go smaller value of ans-me, sn-mp˚ & pp-mp˚ had the highest bite force, this could be explained by those individuals with these characteristics will allow a forward positioning of load application point and this will decrease moment arm in addition to that elevator muscles exhibit greater mechanical advantage with larger cross-sectional area which result in larger bite force. in class ii malocclusion, there is a positive correlation between bite force and go-me(mm), higher values of go-me(mm) resulting in larger size of mandible, increasing the length of mandibular plane and increase in amount of occlusal contact between dental arches which produce higher values of bite force. in class iii malocclusion, there is a positive correlation between bite force and ar-go(mm) l6-mp(mm), s-go (mm) and a negative correlation with n-me(mm), higher values of argo(mm), s-go (mm) and smaller values of nme (mm) producing a tendency toward a square face which result in a higher values of bite force. references 1. braun s, hnat wp, marcotte m, freudenthaler jw, honigle k, johnson be. a study of maximum bite force during growth and development. the angle orthodontist.1996; 66: 261-4. 2. kiliaridis s, kjellberg h, wenneberg b, engström c.the relationship between maximal bite force, bite force 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m. maximum voluntary molar bite force in subjects with normal occlusion. eur j orthod 2010; doi:10.1093/ejo/cjq097. 15.english jd, buschang ph, throckmorton gs. does malocclusion affect masticatory performance? angle orthod. 2002 feb; 72(1):21-7. 16.tsai hh. maximum bite force and related dental status in children with deciduous. j clin pediatr dent 2004; 28, 139-42. j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry134 17.ikebe k, matsuda k, morii k, furuya-yoshinaka m, nokubi t, renner rp association of masticatory performance with age, posterior occlusal contacts, occlusal force, and salivary flow in older adults. int j prosthodont. 2006; sep-oct; 19(5):475-81. 18.angle eh. classification of malocclusion. dental cosmos 1899; 41: 248-64. 19.bishara se. textbook of orthodontics. w.b. saunders company, 2001. 20.sakaguchi m, ono n, turuta h, yoshiike j, ohhashi t. development of new handy type occlusal force gauge. japan j medic electronics and biological engineering 1996; 34: 53-5. 21.rani ms. synopsis of orthodontics. india: laxman chand arya, a.i.t.b.s. publishers and distributors, 1995. 22.rakosi t. an atlas and manual of cephalometric radiography. 2nd ed. london: wolfe medical publications ltd.; 1982. 23.salzmann ja. practice of orthodontics (volume one). 1st ed. philadelphia and montreal: j.b. lippincott company; 1966. 24.björk a, skieller v. normal and abnormal growth of the mandible. a synthesis of longitudinal cephalometric implant studies over a period of 25 years. eur j orthod. 1983;5:1–46 25.biggerstaff rh, allen rc, tuncay oc, berkowitz j. a vertical cephalometric analysis of the human craniofacial complex. am j orthod 1977; 72(4): 397405. 26.bonakdarchian m, askari n, askari m. effect of face form on maximal molar bite force with natural dentition. arch oral biol.2009; 54:201-4. 27.ferrario vf, sforza c, serrao g, dellavia c, tartaglia gm. single tooth bite forces in healthy young adults. j oral rehabil 2004; 31, 18-22. 28.nagasaka m, nagasaka k. interrelationship among the occlusal type, development, the biting force and the ability of exercise in children. j nishi-nippon orthod soc 1996; 41:1–6. 29.staley r n: summary of human postnatal growth, in: bishara s e (ed.), textbook of orthodontics, w.b. saunders, 2001. table 1: descriptive statistics and genders difference in class i normal occlusion variables descriptive statistics genders difference d.f=23 total (n=25) male (n=13) female (n=12) mean s.d. s.e. mean s.d. s.e. mean s.d. s.e. t-test p-value bite force (n) right side 578.48 195.93 39.19 675.31 205.43 56.98 473.58 120.97 34.92 2.96 0.007** left side 576.48 210.94 42.19 677.15 234.86 65.14 467.41 109.35 31.57 2.82 0.010** both sides 577.48 201.73 40.35 676.23 218.63 60.64 470.50 112.42 32.45 2.92 0.008** height (cm) 170.20 10.53 2.11 178.96 6.45 1.79 160.71 2.70 0.78 9.08 0.000*** weight (kg) 68.32 13.26 2.65 77.77 10.15 2.82 58.08 7.17 2.07 5.56 0.000*** table 2: descriptive statistics and genders difference in class i malocclusion variables descriptive statistics genders difference d.f=23 total (n=25) male (n=13) female (n=12) mean s.d. s.e. mean s.d. s.e. mean s.d. s.e. t-test p-value bite force (n) right side 493.76 172.59 34.52 569.08 153.10 44.20 424.23 164.85 45.72 2.27 0.033* left side 486.44 194.77 38.95 555.58 188.65 54.46 422.62 184.52 51.18 1.78 0.088 both sides 490.10 179.47 35.89 562.33 168.26 48.57 423.42 168.62 46.77 2.06 0.050* height (cm) 165.88 9.29 1.86 171.79 6.69 1.93 160.42 8.03 2.23 3.83 0.001*** weight (kg) 68.56 9.62 1.92 69.88 9.97 2.88 67.35 9.52 2.64 0.65 0.523 table 3: descriptive statistics and genders difference in class ii malocclusion variables descriptive statistics genders difference d.f.=23 total (n=25) male (n=13) female (n=12) mean s.d. s.e. mean s.d. s.e. mean s.d. s.e. t-test p-value bite force (n) right side 522.56 186.54 37.31 610.08 182.72 50.68 427.75 143.67 41.47 2.76 0.011* left side 551.72 199.53 39.91 628.15 184.60 51.20 468.92 187.89 54.24 2.14 0.044* both sides 537.14 189.43 37.89 619.12 180.76 50.13 448.33 161.55 46.63 2.48 0.021* height (cm) 164.40 7.24 1.45 169.38 6.22 1.72 159.00 3.33 0.96 5.14 0.000*** weight (kg) 56.80 8.28 1.66 58.77 8.38 2.32 54.67 7.96 2.30 1.25 0.223 j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry135 table 4: descriptive statistics and genders difference in class iii malocclusion variables descriptive statistics genders difference d.f.=23 total (n=25) male (n=13) female (n=12) mean s.d. s.e. mean s.d. s.e. mean s.d. s.e. t-test p-value bite force (n) right side 350.36 166.38 33.28 431.00 152.94 42.42 263.00 137.36 39.65 2.88 0.008** left side 366.12 169.67 33.93 463.38 156.47 43.40 260.75 113.19 32.68 3.68 0.001*** both sides 358.24 164.05 32.81 447.19 150.93 41.86 261.88 119.95 34.63 3.38 0.003** height (cm) 165.10 8.47 1.69 170.81 6.29 1.74 1.74 158.92 1.66 1.66 0.000*** weight (kg) 65.98 14.75 2.95 71.00 15.16 4.20 4.20 60.54 3.67 3.67 0.076 table 5: descriptive statistics and classes difference in total sample variables descriptive statistics classes difference d.f.=99 class i normal class i malocclusion class ii class iii mean mean mean mean f-test p-value bite force (n.) right side 578.48 493.76 522.56 350.36 7.23 0.000*** left side 576.48 486.44 551.72 366.12 5.86 0.001*** both sides 577.48 490.10 537.14 358.24 6.69 0.000*** height (cm) 170.20 165.88 164.40 165.10 2.12 0.103 weight (kg) 68.32 68.56 56.80 65.98 5.52 0.002** j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry136 table 6: pearson’s correlation test between bite force and other variables in class i normal occlusion variables total male female right left both sides right left both sides right left both sides height (cm) r 0.496 0.509 0.507 0.103 0.155 0.132 -0.020 0.136 0.055 p 0.012* 0.009** 0.010** 0.737 0.613 0.668 0.950 0.674 0.865 weight (kg) r 0.456 0.507 0.487 0.175 0.253 0.218 -0.073 0.121 0.020 p 0.022* 0.010** 0.014* 0.568 0.405 0.475 0.822 0.708 0.952 pp-snº r -0.285 -0.284 -0.288 -0.295 -0.254 -0.278 -0.644 -0.586 -0.631 p 0.167 0.169 0.163 0.328 0.402 0.357 0.024* 0.045* 0.028* ans-pns (mm) r 0.496 0.556 0.532 0.220 0.297 0.263 0.236 0.499 0.369 p 0.012* 0.004** 0.006** 0.470 0.325 0.386 0.461 0.099 0.237 ar-go (mm) r 0.510 0.613 0.568 0.483 0.625 0.563 0.327 0.120 0.234 p 0.009** 0.001*** 0.003** 0.094 0.022* 0.045* 0.299 0.710 0.463 go-me (mm) r 0.418 0.430 0.428 0.043 0.000 0.020 0.023 0.089 0.031 p 0.038* 0.032* 0.033* 0.888 0.999 0.948 0.944 0.783 0.924 goº r -0.224 -0.259 -0.244 -0.257 -0.297 -0.280 0.066 0.059 0.064 p 0.281 0.211 0.239 0.397 0.325 0.354 0.838 0.856 0.843 sn-mpº r -0.503 -0.581 -0.548 -0.422 -0.578 -0.508 0.016 0.154 0.084 p 0.010** 0.002** 0.005** 0.151 0.039 0.076 0.959 0.633 0.796 pp-mpº r -0.502 -0.464 -0.483 -0.276 -0.388 -0.338 -0.518 -0.571 -0.556 p 0.011* 0.019* 0.014* 0.362 0.190 0.258 0.084 0.053 0.060 n-me (mm) r -0.370 -0.360 -0.368 -0.048 -0.158 -0.107 -0.234 -0.061 -0.096 p 0.069 0.077 0.070 0.877 0.606 0.727 0.463 0.851 0.766 n-ans (mm) r 0.188 0.201 0.196 -0.141 -0.159 -0.152 -0.466 -0.302 -0.398 p 0.368 0.336 0.347 0.646 0.604 0.621 0.127 0.340 0.201 ans-me (mm) r -0.404 -0.394 -0.402 -0.148 -0.069 -0.107 -0.104 -0.311 -0.208 p 0.045* 0.052 0.046* 0.629 0.824 0.729 0.747 0.324 0.517 s-go (mm) r 0.574 0.625 0.605 0.448 0.557 0.510 -0.224 -0.075 -0.157 p 0.003** 0.001*** 0.001*** 0.125 0.048* 0.075 0.483 0.816 0.625 n-s-arº r 0.040 0.076 0.059 0.044 0.021 0.032 0.090 0.310 0.199 p 0.849 0.718 0.778 0.886 0.945 0.917 0.780 0.327 0.535 s-n (mm) r 0.511 0.555 0.538 0.470 0.503 0.491 -0.396 -0.240 -0.330 p 0.009** 0.004** 0.006** 0.105 0.080 0.088 0.203 0.453 0.296 s-ar (mm) r 0.485 0.453 0.473 0.089 0.099 0.095 0.379 0.234 0.318 p 0.014* 0.023* 0.017* 0.771 0.748 0.757 0.225 0.464 0.314 u6-pp (mm) r 0.373 0.401 0.391 0.313 0.255 0.284 0.096 0.196 0.044 p 0.066 0.047* 0.053 0.298 0.400 0.347 0.767 0.541 0.892 l6-mp (mm) r 0.464 0.472 0.472 0.338 0.373 0.359 -0.035 -0.097 -0.066 p 0.019* 0.017* 0.017* 0.259 0.209 0.228 0.915 0.765 0.840 j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry137 table 7: pearson’s correlation between bite force and other variables in classs ii group variable total male female right left both sides right left both sides right left both sides height (cm) r 0.284 0.239 0.266 0.192 0.115 0.156 0.001 0.062 0.036 p 0.169 0.249 0.199 0.530 0.708 0.612 0.998 0.847 0.912 weight (kg) r 0.044 0.077 0.062 0.225 0.178 0.205 0.087 0.139 0.120 p 0.834 0.714 0.767 0.461 0.560 0.503 0.787 0.666 0.711 pp-snº r -0.019 -0.094 -0.059 -0.177 -0.204 -0.193 -0.387 -0.458 -0.438 p 0.926 0.654 0.779 0.564 0.504 0.527 0.214 0.135 0.154 ans-pns (mm) r 0.160 0.169 0.168 0.248 0.215 0.235 -0.212 -0.037 -0.116 p 0.444 0.418 0.422 0.415 0.481 0.440 0.508 0.909 0.720 ar-go (mm) r 0.277 0.298 0.293 0.250 0.349 0.304 -0.252 -0.137 -0.192 p 0.179 0.149 0.155 0.410 0.243 0.312 0.430 0.670 0.550 go-me (mm) r 0.427 0.385 0.413 0.364 0.384 0.380 0.092 0.071 0.082 p 0.033* 0.058 0.040* 0.221 0.195 0.200 0.776 0.826 0.799 goº r -0.134 -0.099 -0.118 -0.324 -0.386 -0.361 -0.381 -0.378 -0.389 p 0.525 0.639 0.575 0.280 0.192 0.225 0.222 0.226 0.212 sn-mpº r -0.305 -0.290 -0.303 -0.476 -0.505 -0.498 0.108 0.064 0.085 p 0.138 0.159 0.141 0.100 0.079 0.083 0.739 0.843 0.793 pp-mpº r -0.225 -0.213 -0.223 -0.401 -0.416 -0.415 0.185 0.117 0.151 p 0.280 0.306 0.284 0.174 0.158 0.159 0.564 0.716 0.640 n-me (mm) r -0.033 -0.008 -0.021 -0.332 -0.256 -0.298 0.048 0.043 0.046 p 0.875 0.969 0.922 0.268 0.398 0.322 0.883 0.894 0.886 n-ans (mm) r 0.065 0.071 0.069 -0.101 -0.084 -0.094 0.012 0.027 0.011 p 0.757 0.737 0.742 0.743 0.784 0.760 0.970 0.932 0.974 ans-me (mm) r -0.100 -0.082 -0.092 -0.319 -0.270 -0.299 -0.017 -0.018 -0.018 p 0.634 0.697 0.660 0.288 0.372 0.321 0.957 0.956 0.955 s-go (mm) r 0.109 0.094 0.103 0.081 0.054 0.013 -0.532 -0.479 -0.515 p 0.606 0.657 0.625 0.794 0.861 0.966 0.075 0.115 0.086 n-s-arº r 0.010 0.166 0.092 -0.273 -0.107 -0.192 0.508 0.553 0.548 p 0.962 0.429 0.661 0.367 0.729 0.529 0.092 0.062 0.065 s-n (mm) r 0.170 0.192 0.184 0.121 0.286 0.207 -0.278 -0.279 -0.286 p 0.417 0.359 0.377 0.694 0.344 0.498 0.381 0.380 0.368 s-ar (mm) r -0.120 -0.119 -0.122 -0.427 -0.311 -0.375 -0.466 -0.471 -0.481 p 0.568 0.571 0.562 0.146 0.300 0.207 0.127 0.123 0.114 u6-pp (mm) r -0.123 -0.172 -0.151 -0.330 -0.359 -0.350 -0.181 -0.214 -0.205 p 0.558 0.410 0.470 0.272 0.229 0.241 0.574 0.505 0.523 l6-mp (mm) r 0.182 0.193 0.191 0.203 0.293 0.252 -0.104 -0.093 -0.101 p 0.383 0.356 0.360 0.507 0.332 0.407 0.748 0.773 0.756 j bagh college dentistry vol. 25(1), march 2013 relationship of maximum orthodontics, pedodontics and preventive dentistry138 table 8: pearson’s correlation test between bite force and other variables in classs iii malocclusion group variables total male female right left both sides right left both sides right left both sides height (cm) r 0.387 0.365 0.376 0.085 0.004 0.045 0.071 0.079 0.003 p 0.055 0.072 0.063 0.782 0.989 0.883 0.827 0.807 0.992 weight (kg) r 0.325 0.377 0.360 0.023 0.075 0.050 0.391 0.460 0.441 p 0.113 0.063 0.077 0.940 0.809 0.870 0.209 0.132 0.151 pp-snº r -0.102 -0.050 -0.078 -0.037 -0.116 -0.079 -0.311 -0.073 -0.213 p 0.627 0.813 0.712 0.904 0.705 0.797 0.325 0.821 0.507 ans-pns (mm) r 0.110 0.081 0.097 -0.103 -0.066 -0.086 0.278 0.131 0.221 p 0.601 0.702 0.643 0.737 0.832 0.779 0.381 0.686 0.490 ar-go (mm) r 0.326 0.476 0.412 0.234 0.443 0.348 0.003 0.034 0.018 p 0.112 0.016* 0.041* 0.442 0.130 0.244 0.992 0.917 0.956 go-me (mm) r 0.177 0.282 0.235 -0.033 0.092 0.031 -0.128 -0.141 -0.140 p 0.399 0.172 0.257 0.914 0.765 0.920 0.691 0.662 0.664 goº r -0.314 -0.216 -0.271 -0.422 -0.346 -0.393 0.020 0.331 0.168 p 0.126 0.300 0.190 0.151 0.247 0.184 0.952 0.293 0.603 sn-mpº r -0.348 -0.311 -0.337 -0.456 -0.567 -0.525 -0.250 0.092 -0.099 p 0.088 0.130 0.099 0.118 0.043 0.065 0.434 0.776 0.758 pp-mpº r -0.270 -0.259 -0.271 -0.417 -0.485 -0.463 -0.048 0.138 0.038 p 0.191 0.212 0.190 0.156 0.093 0.111 0.882 0.668 0.907 n-me (mm) r -0.070 -0.239 -0.159 -0.565 -0.527 -0.559 -0.242 -0.067 -0.107 p 0.740 0.249 0.447 0.044* 0.064 0.047* 0.448 0.836 0.741 n-ans (mm) r 0.198 0.220 0.214 0.103 0.007 0.056 -0.260 -0.084 -0.188 p 0.343 0.291 0.304 0.737 0.983 0.856 0.415 0.794 0.557 ans-me (mm) r -0.035 -0.124 -0.047 -0.571 -0.499 -0.548 -0.176 -0.112 -0.048 p 0.868 0.553 0.825 0.042* 0.082 0.052 0.584 0.728 0.883 s-go (mm) r 0.424 0.517 0.483 0.229 0.345 0.295 0.064 0.036 0.020 p 0.034* 0.008** 0.015* 0.453 0.248 0.328 0.843 0.912 0.951 n-s-arº r 0.141 0.197 0.173 0.037 0.060 0.050 0.089 0.211 0.150 p 0.501 0.345 0.407 0.905 0.845 0.872 0.784 0.511 0.641 s-n (mm) r 0.316 0.397 0.366 0.218 0.395 0.315 0.266 0.292 0.290 p 0.123 0.049* 0.072 0.473 0.182 0.294 0.404 0.358 0.361 s-ar (mm) r 0.457 0.482 0.481 0.191 0.219 0.211 0.267 0.055 0.179 p 0.022* 0.015* 0.015* 0.532 0.472 0.490 0.401 0.866 0.578 u6-pp (mm) r 0.047 0.233 0.096 0.342 0.071 0.210 0.385 0.035 0.237 p 0.822 0.263 0.647 0.252 0.818 0.491 0.217 0.915 0.459 l6-mp (mm) r 0.084 0.167 0.129 0.587 0.555 0.585 0.237 0.368 0.309 p 0.688 0.424 0.538 0.035* 0.049* 0.036* 0.458 0.240 0.328 j bagh college dentistry vol. 32(4), december 2020 impact of two non-nutritive 12 impact of two non-nutritive sucking patterns on the development of anterior open bite in children of two kindergartens in baghdad city munad j. al duliamy (1) https://doi.org/10.26477/jbcd.v32i4.2913 abstract background: non-nutritive sucking habit (nnsh) is the main environmental causative factor that disturbs normal orofacial development. in spite of the harmful effect of pacifier as a nnsh, mothers aware from the other types of nnsh like thumb sucking far more than pacifier use. open bite is one of the most challenging malocclusions in orthodontics due to the high prevalence of relapse after treatment, so preventing the causative factor of its occurrence is essential at early age of child life. this study aims to assess the impact of two non-nutritive patterns on the development of anterior open bite in primary dentition and to compare which of these habits mostly affect open bite development. materials and methods: the sample consisted of 313 iraqi children (135 boys, 178 girls), aged 3-5 years, enrolled at two public kindergartens in baghdad city, the capital of iraq. a pre-tested questionnaire with clinical examination were used to obtain data regarding thumb sucking, pacifier and the presence of open bite. excel sheets were used for data processing, and chi square test was used in data analysis. results: there was a significant association between nnsh and the development of open bite (p value = 0.01). no gender differences in open bite prevalence were observed. the prevalence of non-nutritive sucking habits and open bite was 63.11% and 52.9% respectively with no gender difference. there was no significant differences between the effect of pacifier and thumb sucking habits on the development of an anterior open bite. conclusion: both pacifier and thumb sucking at preschool age are significant causative factors that lead to development of open bite in primary dentition. encouraging mothers to ban and discontinue pacifier and thumb sucking habits as early as possible in the child's life is a crucial factor to prevent open bite development. on the other hand if general health of the child indicates the use of pacifier, mothers should use an orthodontic pacifier and for short time keywords: non-nutritive sucking, open bite, primary dentition. (received: 20/8/2020; accepted: 1/11/2020) introduction non-nutritive sucking habits (nnsh) are considered as normal healthy behavior and provide the infants with a feeling of comfort, relaxation, pleasure and security during the first few years of life (1). non-nutritive sucking evidences to enhance an infant’s preparedness to initiate oral feeding (2). thumb sucking and pacifier are two distinct forms of non-nutritive sucking patterns in which no food supply is introduced (3). pacifiers are non-nutritive sucking tools that are recommended to calm newborns and infants who subjected to common minor painful procedures like immunization, heel sticks and venipuncture. the use of pacifier during sleep is recommended by the american academy of pediatrics in the 1st year of life to prevent sudden infant death syndrome(4). mothers who have difficulties in breastfeeding use pacifiers as an effective weaning technique(5). prolonged use of pacifier has a negative impact on breast feeding, dental occlusion and may predispose to otitis media(6,3,7). thumb sucking is a habit that is expected to occur in a large percentage of infants. (1) assistant professor, department of pedodontics, orthodontics and preventive dentistry, college of dentistry, mustansiriyah university. corresponding author, dr_munad@yahoo.com it is entirely considered as normal phenomenon when discontinued at one year of age, but can only be considered harmful when continued longer beyond infancy and predisposes to deformity of dental structures (8,9). thumb and finger habits represent the majority of oral habits(10). thumb sucking is usually associated with the infant need to satisfy the urge for contact and may disappear between the ages of 1 and 3½ years (11). prolonged nnsh significantly predisposes to occlusal deformities including anterior open bite(12,13) and exerts unwanted mechanical forces that prevent eruption or enhance the supra-eruption of teeth lacking contact continuously. the lower position of the tongue decreases maxillary oral influence and may widen the mandible. this disturbs the balance of pressure between tongue and perioral musculature and predisposes to a cusp-to-cusp relationship, enhancing the mandible to rotate clockwise, impeding incisor contact and promoting anterior open bite(14). a loss of contact in the vertical relationship of the maxillary and mandibular dental arches is considered as open bite. this loss of contact can occur between the anterior segments (anterior open bite) or between the buccal segments (posterior open bite), and its degree can vary from patient to patient. patients with an open https://doi.org/10.26477/jbcd.v32i4.2913 j bagh college dentistry vol. 32(4), december 2020 impact of two non-nutritive 13 bite tendency or with an anterior open bite are considered the most challenging to treat. after overbite correction by orthodontic treatment and even after surgical orthodontic therapy, relapse of overbite at long-term follow-up is a common sequel (15,16). several etiologic factors are considered to be implicated in anterior open-bite, as opposed to the posterior open bite (17). the use of pacifiers becomes most common than thumb sucking in many societies around the world (18). the present study aimed to assess the impact of two non-nutritive patterns on the development of anterior open bite in primary dentition and to compare which of these habits mostly affect open bite development. materials and methods the scientific committee of research and development of the college of dentistry / mustansiriyah university approved (no.4529 on 2019/11/14) the research proposal. the sample consisted of 313 iraqi children (135 boys, 178 girls), aged 3-5 years, enrolled at two public kindergarten in baghdad city, the capital of iraq. a pre-tested questionnaire with clinical examination were used to obtain data in the present study. the children’ mothers received questionnaires through principals. parental informed consent for the child’s participation is included in the questionnaires. the children included in the study were in the complete deciduous dentition phase with no history of systemic disease, no history of bad oral habit other than thumb sucking. the questionnaire contained information regarding child’ name, gender, age, mother’s age, mother’s educational status, dummy sucking, thumb sucking, history of bad habit (nail-biting, mouth breathing). the children were examined in their own schools after permission while seated in front of the examiner. a single orthodontist (al duliamy) performed the clinical examination under natural illumination. disposable mask, gloves, mouth mirror, cheek retractor, a tongue blade, and orthodontic vernier were used. the presence of anterior open bite was confirmed by clinical examination in centric occlusion as any negative overlap in the vertical plane (when the incisal surfaces of the deciduous lower central incisors below the level of the incisal surfaces of the upper central incisors (10,19). the intra-examiner calibration was done for 20 children by having twice examinations for two-day intervals by the same examiner at the same time of the day. agreement for all parameters was confirmed using kappa statistic. excel sheets were used for data processing and a descriptive analysis of the results was performed. data were statistically analyzed using spss (version 21). chi square was used for inferential data analysis. significance was considered at p>0.05 results only 263 (115 male, 148 female) children were included as other children did not meet the inclusion criteria. table 1 represents the descriptive statistics of the sample. table 2 illustrates that 60.9% of males exhibited nnsh, while 39.13% had no nnsh; 64.8% of females exhibited nnsh, while 35.13% had no nnsh. table 1: descriptive statistics and percentage of the studied sample table 2: distribution of nnsh between genders. table 3 demonstrates that 83.7% of children with nnsh showed anterior open bite, while 16.3 % of children with nnsh exhibited no open bite. table 3: the association between nnsh and the presence of open bite (p>0.05). it was found that 77.6% of children with thumb sucking developed open bite, while 87.0 % of children with pacifier developed open bite (table 4). 263 preschool children % of nnsh nnsh male 115 fema le 148 to tal without nnsh 45 52 97 36.88% thumb sucking 23 35 58 22.0 5% 63.1 1% pacifier 47 61 10 8 41.0 6% open bite male 56 (48.7 %) female 83 (56.1 %) total 139 (52.8 %) 263 preschool children nnsh male 115 female 148 no % no % without nnsh 45 39.13% 52 35.13% thumb sucking 23 20% 60.9 % 35 23.64% 64.8 % pacifier 47 40.9% 61 41.21% open bite in children with nnsh ob free of ob p value nnsh no. % no. % 0.001 139 83.7% 27 16.3% j bagh college dentistry vol. 32(4), december 2020 impact of two non-nutritive 14 table 4: distribution of anterior open bite and type of nnsh. there was no gender differences regarding nnsh and open bite (table 5). table 5: gender differences regarding nnsh and open bite discussion orthodontic treatment need in permanent teeth is highly influenced by malocclusion in the deciduous dentition(20). at early childhood, non-nutritive sucking habits are the main causative factors for developing occlusal abnormalities including anterior open bite (21). in growing children, most of anterior open bites are self-correcting; therefore, the origin of open bite in these age groups is of paramount importance (22). abundant of studies were carried out to assess the prevalence and causative factors that predispose to anterior open bite in different populations and age groups (13, 22-29). the present study was conducted to assess the impact of two non-nutritive sucking habits on the development of anterior open bite among preschool children in baghdad city, the capital of iraq. the prevalence of nnsh in the present study was (63%). this is considered low in comparison with the findings of machado et al., 2014 (30), silvestrini-biavati etal., 2016 (25), machado et al, 2018 (24) that were 70%, 74% and 86% respectively; and high in comparison with the results of ngom et al., 2008 (31) ; chitra & vishnupriya, 2015 (32) and percival et al., 2017 (33) that were 16-17 %, 36 % and 50% respectively. regarding gender difference in the prevalence of nnsh, the present study showed no significant gender differences. this finding is in accordance with the study of scavone-jr et al., 2008 (34); bishara et al., 2006(35) and alves et al., 2016 (36); and disagrees with the study of vasconcelos et al., 2011(37); chitra & vishnupriya, 2015 (32) and percival et al., 2017 (33). this finding in the present study is still considered high due to the common trend of iraqi mothers of using pacifier for calming their children during crying, weaning and other conditions. on the other hand, there is unsound idea among mothers that only thumb sucking has a harmful effect on dentition. the prevalence of anterior open bite in the present study was 52.9%, which is considered low in comparison with 64.2% according to luzzi et al., 2011(38) and high in comparison with findings of de deus et al., 2020 (39); katz et al., 2004(40); alves et al., 2016 (36) and romero et al., 2011(13) that were 44%, 36.4%, 35.4% and 22.4% respectively. these differences in the findings may be due to differences in sample size, age group and ethnic origin of the studies' sample. moreover, the present study showed no correlation between anterior open bite and gender, that is in accordance with the result of ize-iyamu & isiekwe, 2012 (41). according to the findings of the present study, there was a significant correlation between the nnsh and the development of an anterior open bite. this in accordance with the findings of katz et al., 2004(40); katz & rosenblatt, 2005 (42); oliveira et al., 2010 (43); romero et al., 2011 (13) and fialho et al, 2014 (12) studies. regarding the type of nnsh, the present study showed no significant differences between the pacifier and thumb sucking habits on the development of an anterior open bite. this is in agreement with findings of oliveira et al., 2010 (43) and colombi et al., 2017(44). the explanation of open bite development is the unusual swallowing behavior by tongue thrust swallowing during pacifier sucking (45). although the sample size of the present study does not represent baghdad children, the findings support the previously available information about the effects of nnsh on occlusion, and confirm that the pacifier has similar harmful effects on occlusion, as there are more studies about thumb sucking than pacifier use effects (schimid et al., 2018). therefore, the present study raises an additional finding to educate iraqi mothers and society to be aware of the harmful effects of pacifier use due to the common trend that mothers give their children pacifiers for various reasons. nnsh open bite p value ob free of ob 0.116 thumb s. 45 77.6% 13 22.4% pacifier 94 87.0% 14 13.0% gender nnsh open bite p value ob free of ob no n % no n % male thumb s. 17 73.9% 6 26.1% 0.373 pacifier 39 83.0% 8 17.0% female thumb s. 28 80.0% 7 20.0% 0.161 pacifier 55 90.2% 6 9.8% j bagh college dentistry vol. 32(4), december 2020 impact of two non-nutritive 15 conclusion both pacifier and thumb sucking are significant causative factors that may lead to development of anterior open bite in primary dentition. efforts should be taken to encourage the community, especially the mothers to ban and discontinue thumb sucking and pacifier habits as early as possible in the child's life to prevent open bite development. it is the responsibility of orthodontists and dentist to acknowledge mother that pacifier has the same harmful effect that of thumb sucking on impeding the normal development of child occlusion. if general health of the child indicates the use of pacifier, mothers should use an orthodontic pacifier and for short time. conflict of interest: none. references 1. zardetto cg, rodrigues cr, stefani fm. effects of different pacifiers on the primary dentition and oral myofunctional strutures of preschool children. pediatr dent. 2002; 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17(9), 721-727 . 37. vasconcelos fmnd, massoni acdlt, heimer mv, ferreira amb. katz crt, rosenblatt a. non-nutritive sucking habits, anterior open bite and associated factors in brazilian children aged 30-59 months. braz dent j. 2011; 22(2), 140-145 . 38. luzzi v, guaragna m, ierardo g, saccucci m, consoli g, vestri ar, polimeni a. malocclusions and non-nutritive sucking habits: a preliminary study. prog orthod. 2011; 12(2), 114-118 . 39. de deus vf, gomes e, da silva fc, giugliani erj. influence of pacifier use on the association between duration of breastfeeding and anterior open bite in primary dentition. bmc preg child. 2020; 20(1), 1-6 . 40. katz crt, rosenblat a, gondim ppc. nonnutritive sucking habits in brazilian children: effects on deciduous dentition and relationship with facial morphology. am j orthod dentofacial orthop. 2004; 126(1), 53-57 . 41. ize-iyamu in, isiekwe mc. prevalence and factors associated with anterior open bite in 2 to 5 year old children in benin city, nigeria. afri heal sci. 2012; 12(4), 446–451. 42. tornisiello katz cr, rosenblatt a. nonnutritive sucking habits and anterior open bite in brazilian children: a longitudinal study. pediatric dent. 2005; 27(5), 369-373 . 43. oliveira ac, pordeus ia, torres cs, martins mt, paiva sm. feeding and nonnutritive sucking habits and prevalence of open bite and crossbite in children/adolescents with down syndrome. angle orthod. 2010; 80(4), 748-753 . 44. colombi vgg, de souza rc, miotto mh. mb, floriano i, tedesco tk, lara js, imparato jcp. mordida aberta anterior e hábitos deletérios em crianças pré-escolares de escolas públicas. revista brasileira de odontologia. 2017; 74(4), 268 . 45. larsson e. the effect of dummy-sucking on the occlusion: a review. eur j orthod. 1986; 8(2), 127-130 . 46. schmid km, kugler r, nalabothu p, bosch c, verna c. the effect of pacifier sucking on orofacial structures: a systematic literature review. prog orthod. 2018; 19(1), 8 . الخالصة ( هي العامل المسبب البيئي الرئيسي الذي يؤثر سلبا على النمو الطبيعي للفم والوجه. على الرغم من nnshالخلفية: عادة المص غير الغذائية ) ، تخشى األمهات من األنواع األخرى لتلك العادات مثل مص اإلبهام أكثر بكثير احدى عادات المص غير الغذائية التأثير الضار للهاية باعتبارها المفتوحة هي واحدة من أصعب حاالت سوء اإلطباق في تقويم األسنان بسبب ارتفاع معدل انتشار االنتكاس من خطر استخدام اللهاية. العضة ر بعد العالج ، لذا فإن منع العامل المسبب لحدوثها أمر ضروري في سن مبكرة من حياة الطفل. هدف الدراسة: تقييم تأثير نمطين لعادتين غي مامية في األسنان األولية ومقارنة أي من هذه العادات تؤثر في الغالب على ظهور العضة المفتوحة. غذائيتين على ظهور العضة المفتوحة األ سنوات ، مسجلين في روضتين عامتين 53بنت( تتراوح أعمارهم بين 178ولد ، 135طفل عراقي ) 313المواد والطرق: تكونت العينة من يان تم اختباره مسبقًا مع الفحص السريري للحصول على بيانات تتعلق بمص اإلبهام واللهاية في مدينة بغداد عاصمة العراق. تم استخدام استب في تحليل البيانات. النتائج: كان هناك chi squareلمعالجة البيانات ، واستخدم اختبار excelووجود العضة المفتوحة. تم استخدام أوراق (. لم يالحظ أي فروق بين الجنسين في انتشار العضة p = 0.01ر العضة المفتوحة )قيمة وتطو عادات المص غير الغذائيةارتباط معنوي بين ٪( مع عدم وجود فرق بين الجنسين. لم يكن هناك فرق كبير بين انتشار عادات 63.11المفتوحة. كان انتشار عادات المص غير الغذائية مرتفعاً ) العضة لمدرسة من العوامل الهامة المسببة في ظهورلهاية ومص اإلبهام في سن ما قبل اكل من ال تعتبر :االستنتاجات مص اإلبهام واللهاية. المفتوحة في األسنان األولية. إن تشجيع األمهات على حظر ووقف عادات مص اإلبهام واللهاية في أقرب وقت ممكن في حياة الطفل هو عامل ، يجب على األمهات استخدام اللهاية ن من الضروري للصحة العامة للطفل تستوجب، إذا كاحاسم لمنع تطور العضة المفتوحة. من ناحية أخرى .تقويم األسنان ولفترة قصيرة استخدام لهاية dropbox 8 salwan f 44-51.pdf simplify your life j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 7 effect of polyamide (nylon 6) micro-particles incorporation into rtv maxillofacial silicone elastomer on tear and tensile strength abdalbasit a. fatihallah, b.d.s, m.sc., ph.d.(1) manar e. alsamaraay, b.d.s (2,3) abstract background: the longevity of any prosthesis depends on the materials from which it was fabricated, that is why, defects in the material properties may reduce the service life of prosthesis and necessitate its replacement. the aim of this study was to evaluate the effect of adding different concentrations of polyamide-6 (nylon-6) on the tear and tensile strength of a-2186 rtv silicone elastomer. materials and methods: 80 samples were fabricated by the addition of 0%, 1%, 3% and 5% by weight pa-6 micro-particles powder to a2186 platinum rtv silicone elastomer. the study samples were divided into four (4) groups, each group containing 20 samples. one control group was prepared without pa-6 micro particles and three experimental groups were prepared with different percentage of pa-6 micro particles (1%, 3%, and 5%) by weight. each group was further subdivided into 2 groups according to the conducted tests, i.e. tear and tensile strength tests (n=10). the data were analyzed with a descriptive statistical analysis, one-way anova, post-hoc lsd test. results: the mean value of tear and tensile strength of 1% pa-6 reinforcement group increased significantly when compared to control group on the contrast to the same values of 3% and 5% pa-6 reinforcement groups which were decreased significantly. conclusion: the 1% pa-6 reinforcement improved tear as well as tensile strength among all other percentages (0%, 3% and 5%). keywords: polyamide, room temperature, silicone elastomer. (j bagh coll dentistry 2017; 29(4):7-12) introduction patients with facial defects are preferred to be treated through surgical intervention whenever favorable circumstances are present. however; prosthetic restoration for patients suffering from facial deformities may also considered satisfactory; this type of treatment works as a psychological therapy allowing the individuals to integrate again into society after becoming embarrassed, constrained and diminished physically and psychologically. it helps people to reestablish their self-esteem and confidence (1,2) . in general, the goal of prosthodontic rehabilitation is not constrained by restoring function and esthetic; hence, different types of maxillofacial materials have become noticed (3,4). silicone elastomer m a y be considered as the material of choice when fabricating facial prostheses due to its biocompatibility, low chemical reactivity, ease of manipulation, and optical transparency (5). however, its mechanical properties do not fulfill the ideal requirements, resulting in a reduction in the clinical longevity of the prosthesis. that is why; reinforcement of this material may become mandatory to overcome its deficiencies (6). gunay et al. in (2008)(7) reported improvement in the tear strength and other mechanical 1) assistant professor, department of prosthodontics, college of dentistry, university of baghdad 2) m.sc. student, department of prosthodontics, college of dentistry, university of baghdad. 3) department of prosthodontics, college of dentistry, al-mustansiriyah university. properties of a-2186 room temperature vulcanized (rtv) silicone elastomer after being incorporated with tulle (nylon). additionally, various researchers mentioned the use of different types of additives which incorporated within the silicone matrix and resulted in improvement in the mechanical and physical properties of the silicone base material (8,9,10). the aim of the present study was to evaluate the effect of adding different weight percentage (1%, 3%, 5%) of polyamide-6 (nylon-6) on the tear and tensile strength, of a-2186 rtv silicone elastomer. materials and methods this study investigated the tear and tensile strength of a-2186 platinum rtv silicone elastomer (factor ii inc., lakeside, az, usa) before and after the addition of polyamide-6 (nylon-6) micro-particles powder (average particle size 15-20 micron) (goodfellow, cambridge limited, england). a specialized cutting of 4±0.05 mm and 2±0.05 mm thickness acrylic sheets (pt. margacipta wirasentosa, indonesia) is performed by using a laser engraving cutting machine (jl-1612, jinan link manufacture & trading co., ltd., china) to prepare the mold parts. the depth of the mold cavity, 2±0.05 mm thickness sheets, corresponds to the thickness of the specimens to be fabricated for each conducted test while the 4±0.05 mm thickness sheets were used to make the bottom and cover parts (10). a-2186 is a platinum rtv silicone elastomer consisting of 2 parts; part a https://linkcnc.en.alibaba.com/?spm=a2700.8304367.0.0.wsupp2 https://linkcnc.en.alibaba.com/?spm=a2700.8304367.0.0.wsupp2 j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 8 representing the silicone base while part b representing the cross linker. the pa-6 fillers were first weighed by electronic digital balance followed by the addition of accurate weight of silicone (part a) to prevent dispersion of the filler. the modified silicone was mixed by a vacuum mixer (multivac 3, degussa, germany) for 10 minutes; the vacuum was turned off for the first three minutes to avoid suction of the filler and then turned on for the rest of the 7 minutes at 360 rpm speed and a vacuum value of 10 bar. the silicone cross linker (part b) was added to the silicone base (0% pa-6) or the modified silicone (part a and pa-6) and mixed again in the vacuum mixer for 5 minutes to get a homogenous and free bubble mixture (11). the mold was brushed with separating medium and left to dry then the silicone mixture was poured and the mold was closed with the aid of screws and g-clamps (10). according to manufacturer’s instruction, the silicone should be set aside for 24 hours at 23± 2°c and a relative humidity of 50%±10 % for complete setting (figure 1). figure 1: silicone was poured inside the mold after polymerization, the silicone sheet (15×15 cm) (12) was separated from the mold cavity and was cut (figure 2) by suitable cutting dies with the help of a custom-made specimen cutting press. the press consists of hydraulic jack of (3) tons capacity (lezaco, syria) attached to metal plates; this type of cutting ensures smooth cut surfaces. figure (2): specimen's preparation through cutting of the silicone sheet. a, tear specimens; b, tensile specimens all specimens were visually inspected for surface irregularities, bubbles and internal defects (13) then, they were stored inside a vaccine storage box (polar bag, china) for, at least, 16 hours of favorable conditions before testing (2,14,15). all test specimens were tested with a computerized universal testing machine (wdw20, laryee technology co. ltd., china) at 500 mm/min cross-head speed (9).. according to iso 37 (17), forty specimens of type 2 dumb-bell shape were fabricated for tensile strength , 10 specimens were used as control group and the other 30 were silicone specimens after the addition of different concentrations of pa-6 fillers, (n=10). specimens were mounted in a computerized universal testing machine 25±0.5 mm apart (9). the maximum load was calculated by the machine software then the tensile strength was calculated according to the following equation: tensile strength=f/a where: f: the maximum force recorded at break (n). a:the original cross-sectional area of the specimen (mm2). forty specimens of type c which is an unnicked specimen with a 90° angle on one side and with tab end specimens, were fabricated according to astm d624(18) for tear strength test, 10 specimens were used as control group and the other 30 were silicone specimens after the addition of different concentrations of pa-6 fillers, (n=10). specimens were mounted in a computerized universal testing machine with a 30±0.5 mm distance apart (19). the maximum load was calculated by the machine software then the tear strength according to the following equation: tear strength=f/d where: f: the maximum force required for specimen to break (kn). d: the median thickness of each specimen (m). furthermore, sem analysis was performed on 4 samples. one sample represents the silicone material before the addition of pa-6 fillers and the other 3 were after the addition of 1%, 3% and 5% of pa-6 fillers respectively. results 3.1. scanning electron microscope sem results of a-2186 platinum rtv silicone elastomer before and after the addition of 1%, 3% and 5% by weight pa-6 micro-particles powder are shown in (figure 3). a b a b j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 9 figure (3): sem of a-2186 silicone elastomer. a, before the addition of pa-6 fillers; b, after the addition of 1% pa-6 fillers; c: after the addition of 3% pa-6 fillers and d: after the addition of 5% pa-6 fillers sem images demonstrated that when the concentration was increased to 3%, the pa-6 micro particles began to agglomerated; this agglomeration was further increased when the fillers loading increased to 5% as well. 3.2. tear and tensile strength test. figure 4 represents the mean values of tear and tensile strength of a-2186 silicone elastomer before and after the addition of 1%, 3% and 5% pa-6 fillers. highest mean value of tear and tensile strength were found in (1% by weight) pa-6 filler group while the lowest mean value of the both tests were found in (5% by weight) pa6 filler group. figure (4): graphical representation of mean values by bar chart descriptive statistics, one-way analysis of variance (anova), post-hoc lsd analysis, pearson correlation, coefficient of determination and % of variation of the tear and tensile strength values are presented in tables 14. the results of tear strength test indicated highly significant difference (p≤0.01) between all tested groups (table 1). the tear strength mean value of the group formed by the addition of 1% pa-6 micro particles fillers to the silicone elastomer was high significantly (𝑃 ≤ 0.01) greater than that of all other study groups of (0%, 3% and 5%) pa-6 micro fillers (table 2). the results of tensile strength test indicated highly significant difference (p≤0.01) between all tested groups except for the group formed by the addition of 3% pa-6 micro fillers when compared to the control group, where a non significant difference (p≥0.05) was reported (table 3,4). the tensile strength mean value of the group formed by the addition of 1% pa-6 micro particles fillers to the silicone elastomer was high significantly (p≤ 0.01) greater than that of all other study groups of (0%, 3% and 5%) pa-6 micro fillers (table 4). c d table (1): descriptive statistics and one -way analysis of variance (anova) for tear strength test % of pa-6 fillers n mean sd se min. max. anova f-test p. value sig. 0% 10 16.15 0.64 0.20 15.2 17 195.58 0.000 hs 1% 10 20.98 1.21 0.38 19.2 22.79 3% 10 14.54 0.82 0.26 13.72 15.88 5% 10 11.83 0.67 0.21 10.8 12.8 j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 10 discussion tear and tensile properties are the most important properties regarding facial prosthesis (20). in view of the fact, testing the mechanical properties is an important step towards the modification of the current material or acceptance of a new one (9). the aim of this study was to investigate the tear and tensile properties of the tested maxillofacial silicone material which can only be achieved by the addition of correct filler concentration which becomes somehow mandatory because the unfilled cross-linked polydimethylsiloxane has very low mechanical properties (5,21). after the addition of 1% by weight pa-6 micro fillers, the mean value of the tear strength test demonstrated highly significant increase in comparison to the control group by. this may be due to the nature of the fillers; the amide (-conh-) groups within the filler structure are highly polar, so, pa-6 forms multiple hydrogen bonds among adjacent strands (22), this property may result in forming a 3-d network of fillers within the polymer matrix that lead to a change in the overall density and increase overall tearing resistance of the polymer (23). when the filler loading increased to 3%, the mean value of the tear strength test decreased in a highly significant manner in comparison to the control group. moreover, the mean value of the tear strength test also decreased in a highly significant manner in comparison to the control group when the fillers percentage increased to 5%. these changes in the mechanical properties (reduction) can be explained by the sem images (figure 3), where the pa-6 micro particles fillers had agglomerated to a different extent when the fillers loading increased. as depicted in the statistical analysis, the tensile strength test mean value was increased in a high significant manner after the addition of 1% by weight pa-6 micro fillers, in comparison to the control group. this may be due to increasing in table (2): post-hoc lsd, pearson correlation (r), coefficient of determination (r2) and % of variation for tear strength test compared groups lsd mean difference (i-j) p. value sig. r r2 % of variation p. value sig. 0% 1% -4.83 0.000 hs 0.57 0.32 32.49 0.07 ns 3% 1.60 0.000 hs -0.46 0.21 21.16 0.90 ns 5% 4.31 0.000 hs -0.45 0.20 20.25 0.18 ns 1% 3% 6.44 0.000 hs 0.09 0.008 0.81 0.80 ns 5% 9.14 0.000 hs -0.13 0.016 1.69 0.70 ns 3% 5% 2.70 0.000 hs -0.52 0.014 1.44 0.12 ns table (3): descriptive statistics and one -way analysis of variance (anova) for tensile strength test % of pa6 fillers n mean sd se min. max. anova f-test p. value sig. 0% 10 4.40 0.56 0.17 3.44 5.20 29.69 0.000 hs 1% 10 5.74 0.67 0.21 4.70 6.60 3% 10 4.20 0.55 0.17 3.20 4.85 5% 10 3.46 0.38 0.12 2.80 4.00 table (4): post-hoc lsd, pearson correlation (r), coefficient of determination (r2) and % of variation for tensile strength test compared groups lsd mean difference (i-j) p. value sig. r r2 % of variation p. value sig. 0% 1% -1.33 0.000 hs 0.68 0.46 46.24 0.02 s 3% 0.18 0.45 ns -0.34 0.11 11.56 0.32 ns 5% 0.94 0.000 hs 0.29 0.08 8.41 0.40 ns 1% 3% 1.52 0.000 hs -0.39 0.15 15.21 0.26 ns 5% 2.28 0.000 hs 0.39 0.15 15.21 0.26 ns 3% 5% 0.76 0.004 hs -0.30 0.09 9.00 0.39 ns https://en.wikipedia.org/wiki/chemical_polarity https://en.wikipedia.org/wiki/hydrogen_bond https://en.wikipedia.org/wiki/hydrogen_bond j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 11 the overall cross-linking density of the polymer, after the addition of the filler, by forming multifunctional cross-links making the polymer stronger and stiffer; in other words, prevent the polydimethylsiloxane chains from breaking under tensional forces (24). additionally, during testing, the input energy that is responsible of breaking the polymer network may be dissipated into heat by filler incorporation, hence; higher amounts of energy needed to be available to cause the deformation (25). on the contrast to that, a nonsignificant reduction in the tensile strength means value in comparison to the control group was reported. again, when the filler loading increased to 5%, the mean value of the tensile strength test decreased in a highly significant manner in comparison to the control group. this reduction is explained by the sem images (figure 3), where the pa-6 micro particles fillers had agglomerated to a different extent when the fillers loading increased resulting in reducing the mechanical properties of a-2186silicone elastomer. conclusions the following conclusions were reached after taking into consideration the limitations of this study 1. the results of this study revealed significant improvement in the tear strength and tensile strength of a-2186 rtv silicone elastomer after the addition of 1% concentration of pa-6 micro particles powder. 2. as the pa-6 micro particles loading increased to 3% and 5%, impairment in the mechanical properties were noticed. references 1. goiato mc, pesqueira aa, da silva cr, gennari fh, dos santos dm. patient satisfaction with maxillofacial prosthesis. literature review. j plast reconstr aesth surgy 2009; 62(2):175-180. 2. haddad mf, goiato mc, dos santos dm, moreno a, d’almeida nf, pesqueira aa. color stability of maxillofacial silicone with nanoparticle pigment and opacifier submitted to disinfection and artificial aging. j biomed opt 2011; 16(9):095004-095006. 3. marafon pg, mattos bs, sabóia ac, noritomi py. dimensional accuracy of computer-aided design/ computer-assisted manufactured orbital prostheses. int j prosthodont 2 0 1 0 ; 23(3): 271–276. 4. scolozzi p, jaques b. treatment of midfacial defects using prostheses supported by iti dental implants. plast reconstr sur 2004; 114(6): 13951404. 5. hatamleh mm, watts dc. effects of accelerated artificial daylight aging on bending strength and bonding of glass fibers in fiber-embedded maxillofacial silicone prostheses. j prosthodont 2010; 19(5): 357–363. 6. udagama a, drane jb. use of medical-grade methyl triacetoxy silane crosslinked silicone for facial prostheses. j prosthet dent 1982; 48(1): 8688. 7. gunay y, kurtoglu c, atay a, karayazgan b, gurbuz cc. effect of tulle on the mechanical properties of a maxillofacial silicone elastomer. dent mater 2008; 27(6): 775-779. 8. han y, kiat-amnuay s, powers jm, zhao y. effect of nano-oxide concentration on the mechanical properties of a maxillofacial silicone elastomer. j prosthet dent 2008; 100(6): 465-473. 9. zayed sm, alshimy am, fahmy ae. effect of surface treated silicon dioxide nanoparticles on some mechanical properties of maxillofacial silicone elastomer. int j biomater 2014; 2014: 750398-750405. 10. atta allah j, muddhaffer m. influence of artificial weathering on some properties of nano silicon dioxide incorporated into maxillofacial silicone. ijsr 2017; 6(5): pp. 423-428. 11. tukmachi m, moudhaffer m. effect of nano silicon dioxide addition on some properties of heat vulcanized maxillofacial silicone elastomer. jpbs 2017; 12(3-4): 37-43. 12. rai sy, guttal ss. effect of intrinsic pigmentation on the tear strength and water sorption of two commercially available silicone elastomers. j indian prosthodont soc 2013; 13(1): 30-35. 13. iso/tr 27628. workplace atmospheres ultrafine, nanoparticle and nano-structured aerosols inhalation exposure characterization and assessment. 2007. 14. dos santos dm, goiato mc, moreno a, pesqueira aa, de carvalho dekon sf, guiotti a m. effect of addition of pigments and opacifier on the hardness, absorption, solubility and surface degradation of facial silicone after artificial ageing. polym degrad stab 2012; 97(8): 12491253. 15. abdullah ha. evaluation of some mechanical properties of a new silicone material for maxillofacial prostheses after addition of intrinsic pigment. m.sc. thesis, university of baghdad. 2016; 53-58 16. astm g154-06, standard practice for operating fluorescent ultraviolet (uv) lamp apparatus for exposure of nonmetallic materials. astm international, west conshohocken, pa, usa. 2006. 17. iso 37. rubber, vulcanized or thermoplastic — determination of tensile stress-strain properties.2011. 18. astm d624-00. standard test method for tear strength of conventional vulcanized rubber and thermoplastic elastomers. astm international, west conshohocken, pa, usa. 2012. 19. al-harbi fa, ayad nm, saber ma, arrejaie as, morgano sm. mechanical behavior and color change of facial prosthetic elastomers after outdoor weathering in a hot and humid climate. j prosthet dent 2015; 113(2): 146-151. 20. aziz t, waters m, jagger r. analysis of the properties of silicone rubber maxillofacial prosthetic materials. j dent 2003; 31(1): 67-74. j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 12 21. colas a, curtis j. silicone biomaterials: history and chemistry & medical applications of silicones. 2nd ed. elsevier, incorporated; 2005.699, 705. 22. varatharajan s, krishnaraj r, sakthivel m, kanthavel k, palani r. design and analysis of single disc machine top and bottom cover. ijser 2011; 2(8): 2. 23. zhu aj, sternstein s. nonlinear viscoelasticity of nanofilled polymers: interfaces, chain statistics and properties recovery kinetics. compos sci technol 2003; 63(8): 1113-1126. 24. andreopoulos a, evangelatou m, evaluation of various reinforcements for maxillofacial silicone elastomers. j biomater app 1994; 8(4): 344-360. 25. rajkumar k, ranjan p, thavamani p, jeyanthi p, jeyanthi p. dispersion studies of nanosilica in nbr based polymer nanocomposite. rasayan j chem 2013;6(2): 122-133. الخالصة ان استمرار عمل اي تعويضات اصطناعية يعتمد على المادة المصنوعة منها تلك التعويضات لذلك فان اي خلل في نوع المادة سيؤدي الى خلل في استمرارية وديمومة تلك التعويضات ما يستوجب حينها استبدالها. ان الهدف من هذه الدراسه هو بيان تأثير . تم تصنيع a-2186( على قوتي الشد والتمزق لسيليكون الوجه والفكين نوع 6-)نايلون 6-ادة البولي امايداضافة تراكيز مختلفه من م المايكروي الى سيليكون الوجه والفكين المطاطي المفلكن 6-وزنا من مسحوق البولي امايد %5و %3,%1,%8عينة بأضافة 08 عينة. تم تحضير المجموعة 08الى اربع مجاميع, كل مجموعة تحوي . قسمت عينة الدراسة a-2186بدرجة حرارة الغرفة نوع المايكروي, كما تم تحضير المجاميع الثالث االخرى بأضافة تراكيز مختلفه من مادة 6-الضابطه بدون اضافة مسحوق البولي امايد فحص, حيث ان كل مجموعة وزنا( ومن ثم قسمت كل مجموعة الى مجموعتين طبقا لنوع ال %5و %3,%1,) 6-البولي امايد ومجاميع ةقد حسن من خاصيتي الشد والتمزق مقارنة بالمجموعة الضابطه %1عينات. ان تدعيم السيليكون بنسبة 18تحوي الدراسة االخرى. lamia f.doc j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 80 assessment of the relationship between maxillary sinus floor and maxillary posterior teeth root apices using spiral ct scan zainab abdulhasan hussein, b.d.s. (1) lamia h. al-nakib, b.d.s., m.sc. )2 ( abstract background: the purpose of this study is to investigate the relationship between the roots of the maxillary posterior teeth and the maxillary sinus using spiral computed tomography, and measured the distances between the roots of the maxillary posterior teeth and the sinus floor. materials and methods: the sample of the present study was a total of 120 iraqi subject (60 males & 60 females) aged (20-60) years old, who admitted to spiral computed tomography scan unit in al-zahraa hospital in al-kut city to have computed tomography scan of the brain and paranasal sinuses who had complaints of headaches or with suspicion of sinusitis but without pathological findings in maxillary sinuses. from november 2012 to april 2013, ct sagittal reconstructed images were used in this study, images were classified according to the relation between the root apices and the maxillary sinus floor into type1: root apices below the sinus floor, type 2: root apices in cosines floor. vertical distance were measured between the deepest point of the maxillary sinus floor and the root apices of the maxillary first and second premolars and first, second molar contact with the sinus floor) and type 3: root apices penetrate or inside the r using built-in measurement tools. means, standard deviations and minimum and maximum values were calculated for all right and left premolars and molars. t-tests were used to compare measurements between left and right sides and between female and male patients. results: the distance between sinus floor and root apex was longest for the first premolar palatal root apex and shortest for the second molar mesoibuccal root apex for both right and left sides. no statistically significant differences were found between the right and left side measurements or between females and males patients. conclusion: there was no significant difference in vertical relation of maxillary posterior teeth to floor of maxillary sinus between male and female and between right and left side. the mesiobuccal root of the maxillary 2nd molar was closest to the maxillary sinus floor and palatal root of 1st premolar was farthest to the sinus floor. keywords: maxillary posterior teeth, maxillary sinus, spiral ct scan. (j bagh coll dentistry 2013; 25(3):80-86). introduction the maxillary sinus is the first of the paranasal sinuses to develop, and its growth ends with the eruption of the third molars at approximately 20 years of age 1 .sinusitis can result from the spread of a periapical or periodontal infection to the sinus or iatrogenic perforation of the sinus 2. the roots of the maxillary premolar, molar and occasionally canine teeth may project into the maxillary sinus 3. because of the implications this can have on surgical procedures, it is essential for clinicians to be aware of the exact relationship between the apical roots of the maxillary teeth and the maxillary sinus floor. an anatomical description and the relationship between the root apex of the maxillary tooth and the inferior wall of the maxillary sinus are essential for diagnosing sinus pathoses and planning a proper dental implant. the topography of the inferior wall with the maxillary root apices varies according to an individural's age, size and the degree of pneumatization of the maxillary sinus and the state of dental retention 4 .the first and second molar roots are most commonly in close proximity to the inferior wall of the maxillary sinus. occasionally the projecting roots are usually separated from it by various bone thicknesses, but they are some times separated by the sinus mucosa alone. a periapical or periodontal infection of the upper premolars and molars may spread beyond the confines of the supporting dental tissue into the maxillary sinus, causing sinusitis 5.the close relationship of the maxillary sinus and the roots of the maxillary molars can lead to accidental oroantral communication 2. the relationship between the dental roots and the inferior sinus wall is known to influence orthodontic tooth movement 6 and the intrusion or bodily movement of teeth across the sinus floor that occurs with orthodontic treatment has been shown to cause moderate apical root resorption and a high degree of tipping 7. the 3-dimensional reconstruction allows greater accuracy of measurements and an improved visualization of the anatomical situation of the inferior wall with the maxillary root apices 8. (1) m.sc. student, department of oral diagnosis, collage of dentistry, university of baghdad (2) assistant professor, department of oral diagnosis collage of dentistry, university of baghdad j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 81 materials and method the sample of the present study was a total of 120 iraqi subjects (60 males & 60 females) aged 20-60 years old, attending the radiology center of al-zahraa hospital in al-kut city for any maxillofacial complaints for period between november 2012 to april 2013 . ct sagittal reconstructed images were used in this study. assessment vertical relation by measuring the shortest distance between the apex of root of posterior teeth and inner margin in maxillary sinus floor in mm figure 1. the apices extending below the sinus floor were assigned as positive values figure 1 where as those above sinus were assigned as negative values and those contact ms floor but not penetrate inner margin where assigned as 0 value figure 3. images were classified according to the relation between the root apices and the maxillary sinus floor into: type1: root apices below the sinus floor figure 2 type 2: root apices in contact with the sinus floor figure (3) type 3: root apices penetrate or inside the sinus floor figure (4). statistical analyses means, standard deviations and minimum and maximum values were calculated for all right and left premolars and molars. t-tests were used to compare measurements between left and right sides and between female and male patients. figure 1. ct scan show sagittal image of 1st premolar and its palatal root with its positive relation to the floor of ms. figure 2. type1 (buccal root of left first premolar below ms floor) figure 3. type 2 (show palatal root of the left second premolar in contact with ms) figure 4. type 3 (show palatal root of left second molar penetrates or inside the m.s). j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 82 results means, standard deviations and minimum and maximum values obtained from right and left premolars and molars are given in tables 1 and and 2. the distance between sinus floor and root apex was longest for the first premolar root apex and shortest for the second molar mesiobuccal root apex for both right and left sides as in table 1 and 2. no statistically significant differences were found in the measurements for right sides between females and males patients table1. in table 2 showing no significant difference between male and female for left side in all root of posterior teeth in their relation to the floor of ms except the palatal root of second premolar. in male group, there was no significant difference between right and left side in distance of premolars and molars root apices to inner wall of ms except the palatal root of 1st molar and distobuccal root of 2nd molar as in the table 3. in female group, there was no significant difference between right and left side in distance of premolars and molars root apices to inner wall of ms as in the table 4. in 1st premolar there was 99.2% of buccal roots was type 1 from total sample, there was no root type 3 and about 0.83 % type 2. in 2nd molar the high percentage of type 3 was in mb root, high percentage of type 2 was observed in palatal root as in 1st molar and high percentage of type 1was observe in buccal root (mb, db) as in the table 5. table 1. distance from the root apex of the maxillary posterior teeth to the ms floor in each gender in right side (unit mm) tooth root genders descriptive statistics genders differences n mean s.d. s.e. min. max. t-test p-value 1st premolar buccal males 60 7.10 3.46 0.45 1 14.2 -1.92 0.06 (ns) females 60 8.15 2.47 0.32 2.3 13 palatal males 60 7.88 3.80 0.49 1 15.9 -1.80 0.07 (ns) females 59 8.95 2.59 0.34 3.5 14.3 2nd premolar buccal males 60 3.52 3.07 0.40 -4 10 -1.93 0.06 (ns) females 60 4.47 2.26 0.29 0 9.4 palatal males 35 3.39 3.06 0.52 -3 9 -1.94 0.06 (ns) females 34 4.72 2.60 0.45 0 8.8 1st molar mb males 60 1.40 2.76 0.36 -3 13.3 1.40 0.16 (ns) females 60 0.75 2.27 0.29 -4 6.7 db males 60 1.89 2.42 0.31 -2 10.6 0.01 0.99 (ns) females 60 1.89 2.10 0.27 -2 7.2 palatal males 60 1.56 2.38 0.31 -1.8 9.2 0.90 0.37 (ns) females 60 1.17 2.37 0.31 -3 7.2 2nd molar mb males 60 0.16 1.90 0.25 -3 5.1 -1.32 0.19 (ns) females 60 0.60 1.69 0.22 -3 4 db males 60 1.87 2.27 0.29 -1.7 8.5 1.07 0.29 (ns) females 60 1.47 1.75 0.23 -1 5 palatal males 60 0.87 1.98 0.26 -4 5.2 0.58 0.56 (ns) females 60 0.67 1.73 0.22 -5 4 j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 83 table 2. distance from the root apex of the maxillary posterior teeth to the ms floor in each gender in left side (unit mm) tooth root genders descriptive statistics genders differences n m s.d. s.e. min. max. t-test p-value 1st premolar buccal males 60 7.23 3.49 0.45 1 15.5 -0.83 0.41 (ns) females 60 7.71 2.88 0.37 0 15 palatal males 60 7.99 3.46 0.45 2 15 -1.23 0.22 (ns) females 58 8.74 3.17 0.42 0 15.8 2nd premolar buccal males 60 3.61 2.83 0.37 -3 9.6 -1.18 0.24 (ns) females 60 4.12 1.78 0.23 0 7.4 palatal males 32 3.04 2.84 0.50 0 8.8 -2.63 0.01 ** females 39 4.56 2.02 0.32 0 7.9 1st molar mb males 60 1.47 2.30 0.30 -4 7.1 1.79 0.08 (ns) females 60 0.78 1.91 0.25 -3.5 5.1 db males 60 1.81 2.31 0.30 -3.40 7.1 0.67 0.50 (ns) females 60 1.56 1.83 0.24 -1 6 palatal males 60 1.03 2.04 0.26 -3 5.2 -0.16 0.87 (ns) females 60 1.09 2.00 0.26 -2.3 5.6 2nd molar mb males 60 -0.04 1.78 0.23 -3 4.4 -0.67 0.50 (ns) females 60 0.18 1.81 0.23 -4 4 db males 60 1.24 1.72 0.22 -2 5.3 -0.43 0.67 (ns) females 60 1.38 1.83 0.24 -3 4.5 palatal males 60 0.79 1.89 0.24 -2.40 6.2 0.52 0.60 (ns) females 60 0.62 1.80 0.23 -3 5 table 3. vertical distance of root apex of posterior teeth to the floor of maxillary sinus and sides differences in male group tooth root side descriptive statistics sides difference n mean s.d. s.e. mean difference t-test p-value 1st premolar buccal right 60 7.10 3.46 0.45 -0.13 -0.60 0.55 (ns) left 60 7.23 3.49 0.45 palatal right 60 7.88 3.80 0.49 -0.12 -0.49 0.62 (ns) left 60 7.99 3.46 0.45 2nd premolar buccal right 60 3.52 3.07 0.40 -0.09 -0.38 0.71 (ns) left 60 3.61 2.83 0.37 palatal right 35 3.39 3.06 0.52 0.67 1.57 0.13 (ns) left 32 3.04 2.84 0.50 1st molar mb right 60 1.40 2.76 0.36 -0.07 -0.28 0.78 (ns) left 60 1.47 2.30 0.30 db right 60 1.89 2.42 0.31 0.08 0.37 0.71 (ns) left 60 1.81 2.31 0.30 palatal right 60 1.56 2.38 0.31 0.54 2.48 0.02 * left 60 1.03 2.04 0.26 2nd molar mb right 60 0.16 1.90 0.25 0.20 1.16 0.25 (ns) left 60 -0.04 1.78 0.23 db right 60 1.87 2.27 0.29 0.63 2.83 0.01 ** left 60 1.24 1.72 0.22 palatal right 60 0.87 1.98 0.26 0.08 0.33 0.74 (ns) left 60 0.79 1.89 0.24 j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 84 table 4. descriptive statistics and sides differences for the female group tooth root side descriptive statistics sides difference n mean s.d. s.e. mean difference t-test p-value 1st premolar buccal right 60 8.15 2.47 0.32 0.44 1.91 0.06 (ns) left 60 7.71 2.88 0.37 palatal right 59 8.95 2.59 0.34 0.28 0.93 0.36 (ns) left 58 8.74 3.17 0.42 2nd premolar buccal right 60 4.47 2.26 0.29 0.35 1.56 0.12 (ns) left 60 4.12 1.78 0.23 palatal right 34 4.72 2.60 0.45 0.21 0.73 0.47 (ns) left 39 4.56 2.02 0.32 1st molar mb right 60 0.75 2.27 0.29 -0.03 -0.15 0.88 (ns) left 60 0.78 1.91 0.25 db right 60 1.89 2.10 0.27 0.33 1.99 0.052 (ns) left 60 1.56 1.83 0.24 palatal right 60 1.17 2.37 0.31 0.09 0.41 0.68 (ns) left 60 1.09 2.00 0.26 2nd molar mb right 60 0.60 1.69 0.22 0.42 1.64 0.11 (ns) left 60 0.18 1.81 0.23 db right 60 1.47 1.75 0.23 0.09 0.36 0.72 (ns) left 60 1.38 1.83 0.24 palatal right 60 0.67 1.73 0.22 0.06 0.22 0.82 (ns) left 60 0.62 1.80 0.23 table 5. frequency and percentage of roots and their relation to the maxillary sinus in total sample (240 teeth). tooth root relation of the root to the maxillary sinus inside the sinus type3 with the level of the sinus type2 below the sinus type1 no root no. % no. % no. % no. % 1st premolar buccal 0 0 2 0.83 238 99.2 0 0 palatal 0 0 2 0.83 235 97.9 3 1.25 2nd premolar buccal 4 1.67 33 13.8 203 84.6 0 0 palatal 2 0.83 22 9.17 116 48.3 100 41.7 1st molar mb 43 17.9 82 34.2 115 47.9 0 0 db 11 4.58 87 36.3 142 59.2 0 0 palatal 20 8.33 126 52.5 94 39.2 0 0 2nd molar mb 80 33.3 63 26.3 97 40.4 0 0 db 22 9.17 73 30.4 145 60.4 0 0 palatal 26 10.8 131 54.6 83 34.6 0 0 discussion the anatomical relation between the maxillary sinus and the teeth is a complex one, due to the variable extension of the sinus. the relations between the dental roots apices and the sinus floor are critical elements for the diagnosis and surgical treatment of antral pathology. the results obtained in this study are useful both in endodontics and in oral surgery, the antrum–teeth relations interfere with teeth removal and immediate placement of dental implants in the lateral maxillary region. identification of the distance between the dental roots apices and the sinus floor and the establishment of the available bone thickness are imperative requirements in case of surgical procedures of this area 9. in the present study the classification was considered into three types of the vertical dentoantral relations, simpler and much useful with regard to oral surgery than the classification of kwak et al4 that presents five types of these relations who found that the most frequent vertical relationship was a sinus floor that did not contact the dental roots. eberhardt et al10 found the mean distance between the maxillary posterior teeth and the maxillary sinus floor to be 1.97 mm(not contact ms floor), sharan and madjar and kilic et al 11,12 found that the sinus floor did j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 85 not contact the roots of the molars which disagreed with present study that found apical protrusion into the maxillary sinus (type 3) of one or more roots of the molars was frequent although the roots being separate from the sinus(type1) was most frequent in each root of the molars this result agree with jung and cho 13 found apical protrusion into the maxillary sinus of one or more roots of the molars was most frequent in the study although the roots being separate from the sinus was most frequent in each root of the molars. because of the very close anatomical relationship that exists between the maxillary posterior teeth root apices and the sinus floor, endodontic surgery of premolars and molars can result in accidental oroantral communication that can allow bacteria from infected periapical tissue, resected root tips, or bony drilling dust to be displaced into the sinus and cause acute or chronic sinusitis 14,15. sharan et al 11 reported that only 39% of the teeth roots that projected on the sinus cavity in panoramic radiographs showed protrusion on the sinus with ct and the panoramic radiographs showed a statistically significant 2.1 times longer root projection on the sinus cavity in comparison to the root protrusion length into the sinus measured by using ct images. in order to avoid disadvantages such as superposition of anatomic structures, horizontal and vertical magnification and a lack of cross-sectional information that are associated with panoramic radiographs, the present study was conducted using ct images only. kilic et al 12 reported that the distobuccal root of m2 was closest to the sinus floor because he used cone beam ct the present study disagree with their results. the results of the present study showed that the distance between the sinus floor and the root of the molar was shortest for the mesiobuccal roots of 2nd molar, for which type 3 was frequent and longest for the palatal roots of 1st premolar , for which type 1 was most frequent this result agree with yoshimine et al 16 who found vertical distance between the apex of the roots and the maxillary sinus floor showed a positive correlation on the maxillary 1st premolar (p = 0.003). as with other apicectomies, complications encountered during periapical surgery of the maxillary molars and premolars can include damage to a neighboring tooth. with regard to the specific treatment of maxillary molars and premolars, careful aperture of the maxillary sinus wall or floor is necessary, and attention must be paid to avoid sinus membrane perforation and the introduction of foreign bodies into the maxillary sinus 15,17-19. ericson et al 14 reported that out of 159 maxillary premolars and molars treated with periapical surgery, aperture of the wall or floor of the maxillary sinus occurred in 18 percent of cases. the authors also stated that the introduction of foreign bodies into the maxillary sinus during surgery could cause thickening of the sinus mucosa and symptoms of maxillary sinusitis. knowledge of the distances between the roots and the sinus floor is useful for evaluation of the diameter and length of the dental implants, especially for immediate implant placement and preoperative treatment planning of maxillary posterior teeth 12. ct scan is an excellent imaging modality used to evaluate the vertical relation of root apex of posterior teeth to the inner wall of maxillary sinus. in 2nd molar the high percentage of type 3 was in mb root, high percentage of type 2 was observe in palatal root the shortest distance to the floor of ms was for mesiobuccal root of 2nd molar and the longest was palatal root of 1st premolar. references 1misch ce. contemporary implant dentistry. 2nd ed. st. louis: cv mosby co; 1999. pp. 76–194. 2hauman ch, chandler np, tong dc. endodontic implications of the maxillary sinus: a review. int endod j 2002; 35:127–141. 3tank pw. grant’s dissector. 13th ed. philadelphia: lippincott williams & wilkins; 2005. p. 198. 4kwak hh, park hd, yoon hr, et al topographic anatomy of the inferior wall of the maxillary sinus in koreans. int j oral maxillofac surg 2004; 33: 382-8. 5monkhouse s. cranial nerves functional anatomy. 2nd ed. new york: cambridge university press; 2006. p. 59 6fuhrmann r, bucker a, diedrich p. radiological assessment of artificial bone defects in the floor of the maxillary sinus. dentomaxillofac radiol 1997; 26: 112–6. 7wehrbein h, diedrich p. the initial morphological state in the basally pneumatized maxillary sinus–a radiological-histological study in man. fortschr kieferorthop1992; 53: 254–62. 8annabelle bouquet, jean-loup coudert, denis bourgeois, et al, contributions of reformatted computed tomography and panoramic radiography in the localization of third molars relative to the maxillary sinus. oral surg oral med oral pathol oral radiol endod 2004; 98: 342-7. 9nimigean v, vanda r, nicoleta măru. sălăvăstru, daniela bădiţă, mihaela jana ţuculină the maxillary sinus floor in the oral implantology. romanian morphology and embryology 2008; 49(4): 485–9. 10eberhardt ja, torabinejad m, christiansen el. a computed tomographic study of the distances between the maxillary sinus floor and the apices of the j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 86 maxillary posterior teeth. oral surg oral med oral pathol 1992; 73: 345–6. 11sharan a, madjar d. correlation between maxillary sinus floor topography and related root position of posterior teeth using panoramic and cross-sectional computed tomography imaging. oral surg oral med oral pathol oral radiol endod 2006; 102: 375-81. 12kilic c, kamburoglu k, yuksel sp, et al. an assessment of the relationship between the maxillary sinus floor and the maxillary posterior teeth root tips using dental cone-beam computerized tomography. eur j dent 2010; 4: 462-7. 13jung yh, cho bh. assessment of the relationship between the maxillary molars and adjacent structures using cone beam computed tomography. imaging sci dent 2012; 42 (4): 219-24. 14ericson s, finne k, persson g. results of apicoectomy of maxillary canines, premolars and molars with special reference to oroantral communication as a prognostic factor. int j oral surg 1974; 3: 386–93. 15watzek g, bernhart t, ulm c. complication of sinus perforation and their management in endodontic. dental clinic of north america 1997; 41: 563-83. 16yoshimine s, nishihara k, et al. topographic analysis of maxillary premolars and molars and maxillary sinus using cone beam computed tomography. implant dent 2012; 21(6): 528-35. 17persson g. periapical surgery of molars. int j oral surg 1982; 11: 96–100. 18wallace ja. trans-antral endodontic surgery. oral surgary oral med oral pathol 1996; 82: 80-3. 19khongkhunthian p, reichart pa.aspergillosis of the maxillary sinus as a complication of overfilling root canal material into the sinus: report of two cases. j endod 2001; 27: 476–8. j bagh college dentistry vol. 29(4), december 2017 oral health among pedodontics, orthodontics and preventive dentistry 96 oral health condition and nutritional status among cleft lip and palate in baghdad-iraq mais m. almaeeni, b.d.s. (1) abeer m. hassan, b.d.s., m.sc. (2) abstract background: orofacial cleft is the most common craniofacial birth defect and the fourth most common congenital malformation in humans that have an effect on oral health in addition to nutrient intake affected in those children. this research aims to investigate gingival condition, dental caries experience and nutritional status among children with orofacial cleft and compare them with normal children. materials and methods: the study group included 36 children with an age ranged (4-9) years of orofacial cleft. the control group included 37 children matched the control group in age and gender. gingival condition measured by gingival index (löe and silness, 1963), while dental caries status was measured by (d1-4mfs/d1-4mfs) index according to the criteria of manji et al (1989). the nutritional status was assessed using body mass index for age. data analysis was conducted through the application of the spss (version 21). results: the dmfs, dmfs and ds mean values were higher in study group than control group with no statistically significant differences, while ds mean values were higher in study group than control group with highly significant difference. gi mean values were higher in study group than control group with statistically highly significant difference. no significant difference in body mass index between study and control groups. concerning severity, the study group had more gingival inflammation severity than control group, while regarding dental cries severity only grades d1, d3 and d4 were significantly increased in study group than control group. conclusion: the children with orofacial clefts had increased risk for dental caries and gingival inflammation than normal children. the nutritional status was not different between children with orofacial cleft and healthy children. key words: cleft lip and palate, nutrition, dental caries, gingival condition. (j bagh coll dentistry 2017; 29(4): 96-101) introduction orofacial cleft (ofc) is the most common craniofacial birth defect and the fourth most common congenital malformation in humans (1, 2). the craniofacial structures development is a coordinated process involving the growth of multiple independently derived embryologic prominences called primordia. incomplete fusion of this facial structures during the fourth to eighth week of embryologic life results in a gap leads to cleft lip, cleft of the primary or secondary palate, or a combination of them. elevated infant mortality and significant lifelong morbidity are associated with ofc such as cosmetic deformities, feeding problems, swallowing difficulties, failure to gain weight, change in nose shape, recurrent ear infections, poor growth of the maxilla, speech difficulties, misaligned teeth and dental abnormalities (2-4). persons with ofc are at a significant risk for periodontal disease and dental caries (5-8). body growth is important in ofc children because it reflects the accumulation of metabolism over time (9). many factors, such as feeding problems, recurrent respiratory infections and reconstructive surgery may affect the growth pattern of ofc children (10-12). the nutrient intake of ofc children was little different from that of normal children (13). (1) master student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. another study found that nutritional status had no average differences from norms for children with ofc (9). this study was designed and conducted in order to gain knowledge about nutritional status, dental caries experience and gingival condition among children with orofacial cleft and compares them with normal children. materials and methods this study was carried out in baghdad city, iraq. informed consent was obtained from each participant enrolled in this study before any data collection and examination of oral health. two groups were examined with age range (4-9). the study group included thirty-six children, which matched the inclusion criteria and attended alwasity and ghazi alhareery teaching hospitals/ maxillofacial departments. the inclusion criteria of the study group were as follow: (1) non-syndromic ofc, (2) surgically repaired, (3) cleft with bone involvement. the control group, which included thirty-seven healthy children, those children attended pedodontics department at baghdad dentistry college. control group matched study group in age and gender. dental caries and its severity were assessed according to decayed, missed and filled surfaces (d1-4 mf/ d1-4 mfs) index (14). the gingival health condition was assessed by gingival index (15). height was measured using an ordinary measuring tape fixed at true vertical, flat surface, j bagh college dentistry vol. 29(4), december 2017 oral health among pedodontics, orthodontics and preventive dentistry 97 while body weight measurements were taken on digital scale (16). the percentile growth chart defined by the cdcp (center for disease control and prevention) was used to indicate the bmi according to age and gender (17). data analysis was conducted through the application of the spss (version 21) and microsoft office excel (2007). statistical analysis can be classified into two categories: (1) descriptive analysis which include percentage for nominal variables while mean, standard deviation (sd) and standard error se for numeric variables and graphs, (2) inferential analysis which include levene test and two independent samples t-test. the confidence limit was accepted at 95% (p <0.05). results results showed that there is no significant statistically differences between boys, girls and age groups; for that reason the whole sample were considered as one group without subgrouping according to gender and age. table 1 and 2 showed caries experience and caries severity differences between study and control groups for permanent and primary dentition respectively. the dmfs and ds means were higher in study group than control group with no statistically significant difference (p>0.05), while the dmfs and ds means were higher in study group than control group with no statistically significant difference (p>0.05) for dmfs and highly significant difference (p<0.01) for ds component. the gingival index means among the study and control groups are illustrated in table 3. the table shows that gi means were higher in study group than control group with statistically highly significant difference (p<0.01). the gingival inflammation severity illustrated in figure 1. the figure shows that healthy gingiva was absent in study group, while the percentage of it within control group was 10.80%. the percentage of mild type of the gingival inflammation within study group was 72.20%, while its percentage within control group was 86.50%. the percentage of moderate type of the gingival inflammation within study group was 27.80%, while its percentage within control group was 2.70%. the sever type of the gingival inflammation was absent in both study and control groups. table 4 illustrates the mean values and standard deviations of the bmi among study and control groups. this table shows that no significant difference in bmi between study and control groups (p>0.05). the numbers and percentages of underweight, healthy, at risk of overweight and obese children in study and control groups represented in table 5. the percentage of underweight children within study group was 2.8%, while its percentage within control group was 5.4%. the percentage of healthy children within study group was 91.7%, while its percentage within control group was 73%. the percentages of both at risk of overweight and obese children within study group were 2.8%, while their percentages within control group were 10.8%. table 1: caries experience and caries severity differences between study and control groups for permanent dentition. variables groups independent sample test study control t# df sig. n mean ±sd se n mean ±sd se d1 23 1.00 1.38 0.29 33 0.91 1.26 0.22 0.255 54 0.799 d2 23 2.26 2.20 0.46 33 1.73 1.99 0.35 0.946 54 0.348 d3 23 0.04 0.21 0.04 33 0.30 1.02 0.18 -1.426 35.80 0.162 d4 23 0.70 2.22 0.46 33 0.03 0.17 0.03 1.431 22.19 0.166 ds 23 4.00 3.55 0.74 33 2.97 3.09 0.54 1.154 54 0.253 ms 23 0.22 1.04 0.22 33 0.00 0.00 0.00 1.000 22 0.328 fs 23 0.17 0.65 0.14 33 0.18 0.53 0.09 -0.050 54 0.960 dmfs 23 4.39 4.15 0.87 33 3.15 3.19 0.56 1.263 54 0.212 #=not significant at p>0.05. j bagh college dentistry vol. 29(4), december 2017 oral health among pedodontics, orthodontics and preventive dentistry 98 table 2: caries experience and caries severity differences between study and control groups for primary dentition. variables groups independent sample test study control t df sig. n mean ±sd se n mean ±sd se d1 36 1.75 1.63 0.27 37 0.86 1.21 0.20 2.63 * 64.47 0.011 d2 36 4.58 5.17 0.86 37 5.11 3.57 0.59 -0.51 71 0.614 d3 36 4.28 5.44 0.91 37 1.54 2.28 0.37 2.79 ** 46.65 0.008 d4 36 5.83 7.94 1.32 37 2.57 4.39 0.72 2.17 * 54.23 0.035 ds 36 16.44 11.23 1.87 37 10.08 6.17 1.01 2.99** 54.03 0.004 ms 36 1.89 4.15 0.69 37 3.76 5.38 0.88 -1.66 71 0.102 fs 36 0.53 1.73 0.29 37 0.95 2.54 0.42 -0.82 71 0.415 dmfs 36 18.86 12.04 2.01 37 14.78 8.72 1.43 1.66 71 0.101 *=significant at p<0.05, **=highly significant at p<0.01. table 3: the gingival index difference among the study and control groups. variable groups independent sample test study control t df sig. mean ±sd se mean ±sd se gi 0.90 0.31 0.05 0.37 0.26 0.04 7.989** 71 0.000 **=highly significant at p<0.01. table 4: the bmi difference among the study and control groups. variable groups independent sample test study control t# df sig. mean ±sd se mean ±sd se bmi 15.69 1.13 0.19 16.59 2.82 0.46 -1.79 47.54 0.081 #=not significant at p>0.05. table 5: the distribution of the study and control group according to nutritional status. nutrition groups study control n % n % underweight 1 2.8 2 5.4 healthy 33 91.7 27 73.0 at risk overweight 1 2.8 4 10.8 obese 1 2.8 4 10.8 j bagh college dentistry vol. 29(4), december 2017 oral health among pedodontics, orthodontics and preventive dentistry 99 figure 1: the gingival inflammation severity among study and control groups. discussion the present study data showed that there was no significant difference for dmfs between study and control groups, this result agreed with some previous studies conducted by lucas et al and cheng et al (18-19), while it was controversial with the findings of others (3, 4, 7). this may due to that caries is a chronic infectious disease and the dmf/dmf index is a lifetime cumulative index of dental disease and treatment and may have little bearing on caries activity at a specific point in time; also the age range for the present study is short for permanent dentition observation (20). concerning dmfs and ds component were higher in study group than control group. these results agreed with ja’afar and dahllöf et al (3,5) and disagreed with other study conducted in jordan (7). increased caries experience in children with ofc could be relate to dental abnormalities and the restricted access to proper oral hygiene and natural cleansing of the teeth because of the loss of elasticity and the anatomy of surgically repaired lip leads to fear of brushing around this area (5, 21), also tenacious nature of nasal fluid that drain from the palatal fistula enhances dental plaque stickiness (22), on the other hand parents are usually unaware of their children’s increased susceptibility to dental caries and insufficient education about tooth brushing techniques and the important of oral hygiene and dietary practices, also they are more concerned with other aspects of care (surgery and speech development) so that the oral health at the lower end of the priority scale unless the child has discomfort (18, 19). the results of current study showed that the mean value of gingival index for the study group was higher than that for the control group with statistically highly significant difference between two groups. this result was also reported by studies conducted previously (5, 7) and disagreed with others (8, 18). as mentioned previously, the maintenance of oral hygiene influenced by the cleft deformity and the surgical scars, also the children’s families preoccupied with other aspects of care (5). prolonged orthodontic therapy and wearing of prosthesis to prevent collapse of the dental arch commonly result in gingival inflammations (23). tissue discontinuation of alveolar and palatal area allows pathological bacterial colonies migration between the oral and the nasal cavities (8). no significant difference was found in present study regarding bmi between study and control groups. this agreed with findings of bowers et al and gopinath (9, 13). the percentage of underweight children within study group was lower than that within control group. the percentage of healthy children within study group was higher than that within control group, but the control group experienced increased percentages of both at risk of overweight and obese than study group. this could be relate to adequate nutritional intake in hospitals before and after surgical intervention to facilitate healing and growth and may relate to parental education and motivation concerning the importance of good nutrition (13). this study made novel observations in iraq that will provide a platform for further research that must collect additional and more detailed dietary analysis on a larger group of patients and longer duration in order to make entirely conclusive quantitatively results. references 1. jugessur a, farlie pg, kilpatrick n. the genetics of isolated orofacial clefts: from genotypes to subphenotypes. oral disease 2009; 15: 427–435. 2. szabo gt, tihanyi r, csulak f, jambor e, bona a, mark l. comparative salivary proteomics of cleft palate patients. cleft palate–craniofacial journal j bagh college dentistry vol. 29(4), december 2017 oral health among pedodontics, orthodontics and preventive dentistry 100 2012; 49(5): 519-23. 3. ja’afar zj. oral health status and treatment needs among (3-12) years old children with cleft and/or palate in iraq. master thesis, pedodontic department, 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clefts of the lip, palate, and craniofacial structure. scandinavian journal of plastic and reconstructive surgery 1987; 21(1): 7-14. 10. becker m, m.d. henry svensson m, kallen b. birth weight, body length, and cranial circumference in newborns with cleft lip or palate. cleft palate– craniofacial journal 1998; 35(3): 255-61. 11. masarei ag, sell d, habel a, mars m, sommerlad b, wade a. the nature of feeding in infants with unrepaired cleft lip and/or palate compared with healthy noncleft infants. cleft palate–craniofacial journal 2007, 44(3): 321-328. 12. deshpande rr, bendgude v, metha bs, jadhav m, mutha m, chhabra rs, gadkari tv. correlation between salivary constituents of father and child. asian j pharm clin res 2014; 7(1): 59-61. 13. gopinath vk. assessment of nutrient intake in cleft lip and palate children after surgical correction. malays j med sci 2013; 20(5): 61-6. 14. manji, f. fejerkov, o. baelum, v. 1989. pattern of dental caries in an adult rural population. caries res, 23, 55-62. 15. löe h, silness j. periodontal disease in pregnancy. j acta. odontol scand 1963; 21: 533-551. 16. gronder m, anderson sl, deyoung s. foundation and clinical application of nutrition. 2nd ed. mosby: 2000. p.440-5 17. ogden cl, kuczmarski rj, flegal km, mei z, guo s, wei r, grummer-strawn lm, curtin lr, roche af, johnson cl. centers for disease control and prevention 2000 growth charts for the united states: improvements to the 1977 national center for health statistics version. pediatrics 2002; 109(1): 45-60. 18. lucas vs, gupta r, ololade o, gelbier m, roberts gj. dental health indices and caries associated microflora in children with unilateral cleft lip and palate. cleft palate–craniofacial journal 2000; 37(5): 447-52. 19. cheng l, moor s, kravchuk o, meyers i, ho c. bacteria and salivary profile of adolescents with and without cleft lip and/or palate undergoing orthodontic treatment. australian dental journal 2007; 52(4): 31521. 20. thaweboon s, thaweboon b, nakornchai s, jitmaitrees. salivary secretory iga, ph, flow rates, mutans streptococci and candida in children with rampant caries. southeast asian j trop med public health 2008; 39(5): 893-9. 21. johnsen dc, dixon m. dental caries of primary incisors in children with cleft lip and palate. cleft palate j 1984; 21(2): 104–9. 22. turner c, zagirova af, frolova le, courts fj, williams wn. oral health status of russian children with unilateral cleft lip and palate. cleft palate craniofacial j 1998; 35: 489–494. 23. wong fw, king nm. the oral health of children with clefta review. cleft palate-craniofacial journal 1998; 35(3): 248-54. j bagh college dentistry vol. 29(4), december 2017 oral health among pedodontics, orthodontics and preventive dentistry 101 بين شق الحنك والشفة الوالدي في بغداد ـ التغذویة الحالة حالة الفم الصحية و العراق الخالصة عند ثرتتأ قد التغذوية الحالة. البشر كثر شیوعا فيألاويعتبر ھو رابع تشوه خلقي والديقحفي عیب ھو الحنكو الشفة شق :خلفية التغذوية الحالة دراسة إلى البحث ھذا يھدف. واألسنان الفم صحة سالمة على تؤثر اللثة لتھابوإ األسنان تسوس. طفالاأل ھؤالء .السلیمین األطفال مع ومقارنتھا والشفة الحنك شق من يعانون الذين األطفال بین اللثة حالة و األسنان وتسوس عمارھمأ احوتتر )المجموعة تحت الدراسة( اب بشق الحنك والشفة الوالديصم طفال ٦٣ الدراسة ھذه تضمنت :والطرق المواد قیاس تموقد تم مراعاة تطابق العمر والجنس بین المجموعتین. )المجموعة الضابطة( طفل سلیم ٦٣ ع( سنوات تمت مقارنتھم م٩ـ٤) مراض اللثة فقد تم أما أ ، et al(manji 1989)(وفقا لمعايیر )mfs)4-1dmfs/4-1d ستخدام دالة التسوسسريريا من خالل إ األسنان تسوس أجري تحلیل البیانات .للعمر بالنسبة الجسم كتلة مؤشر ستخدامبأ تغذويةال الحالة تقییم تم. (löe and silness, 1963 ) ايیرقیاسھا وفقا لمع (.12اإلصدار ssssمن خالل تطبیق برنامج ) في المجموعة تحت الدراسة من المجموعة أعلى قیم لمتوسط الرتبكانت sdو sfmd،sfmd ان وجد في ھذه الدراسة :النتائج تحت مجموعة ال في أعلى كانت (sdاللبنیة )سنان فیما يخص السطوح المسوسة لأل حصائیة.ابطة مع عدم وجود فارق ذو داللة إالض مجموعة في أعلى كانت (igقیم متوسطات التھاب اللثة ) ا انالدراسة مع فارق ذو داللة احصائیة عالیة. ھذه الدراسة اظھرت ايض كثر شدة في المجموعة تحت الدراسة من إلتھاب اللثة كان أ .عالیة إحصائیة داللة ذو فارق مع الضابطة المجموعة من الدراسة إزدادت بشكل ملحوظ في المجموعة تحت الدراسة من 1d ,3dوd 4 بما يتعلق بشدة التسوس، فقط الدرجات عة الضابطة.المجمو .الضابطةو الدراسة ن تحتمجموعتیال بین الجسم كتلة مؤشر في كبیر فرق يوجد الالمجموعة الضابطة. ، السلیمین األطفال من اللثة لتھابوإ األسنان لتسوس كثر عرضةأالشفة والحنك الوالدي شق من يعانون الذين األطفال إن :ستنتاجاإل الشفة والحنك الوالدي. شق من يعانون الذين ألطفالل التغذوية الحالة على تأثیر شق الشفه والحنكل لیس كذلك .اللثة حالة األسنان، تسوس التغذية،والحنك، الشفة شق :الرئيسية الكلمات enas f.doc j bagh college dentistry vol. 25(2), june 2013 the effect of different orthodontics, pedodontics and preventive dentistry143 the effect of different oral hygiene regimens on the quantity of cariogenic plaque on orthodontic bands with different attachments (a clinical photographic study) enas j. almusawi, b.d.s. (1) hayder f. saloom, b.d.s., m.sc. (2) abstract background: fixed orthodontic appliances impede the maintenance of oral hygiene and result in plaque accumulation leads to enamel demineralization caused by acids produced by bacteria. studies on plaque control strategies in orthodontic populations are limited. this might be caused by difficulties in the quantitative evaluation of dental plaque because the teeth have various levels of bracket coverage, and different tooth sizes and malocclusions, making the traditional categorical indices complex. the present study aims to evaluate the effect of different hygiene protocols on plaque quantity on bands with different attachments. materials and method: twenty patients had four bands within the orthodontic appliance. then randomly divided into four groups of hygiene regimens where group a used chlorhexidine dentifrice, group b used fluoridated dentifrice, group c used chlorhexidine mouthwash along with chlorhexidine dentifrice and group d used chlorhexidine mouthwash in addition to the fluoride dentifrice. bands were removed four weeks after the appliance been in place, cut out carefully into 2 pieces from the center of the mesial and distal contact areas, biochemical test (clinprocario l-pop) was applied then 80 digital photographs were obtained. four areas of interest were estimated which are mesially and distally to each attachment (2 mm) in width each. percentage of plaque in these areas was calculated and statistically analyzed. results: side difference revealed that the plaque accumulated on the right sided bands more than the left, however the difference was not significant. it was also found that the lower bands had insignificantly higher amount of plaque than the upper ones. conclusions: the four groups of oral hygiene regimens have no significant different effects on the plaque amount. moreover, the oral hygiene maintenance is more difficult in the right side than the left side but the difference was not significant. the lower arch accumulated insignificantly more plaque than the upper. also, difference in attachments has no influence on plaque amount. keywords: cariogenic plaque, plaque quantity, clinprocario l-pop, orthodontic bands, oral hygiene. (j bagh coll dentistry 2013; 25(2):143-148). introduction orthodontic treatment can improve the selfimage of patients through the provision of better esthetics and a more attractive smile. in addition, orthodontics can in principle have long-term health advantages for patients, since crooked and crowded teeth are difficult to clean and maintain. despite the post therapy health advantages of orthodontics, the treatment regimen itself creates obstacles for patients, because orthodontic brackets create plaque-retentive sites that impede tooth cleaning. dental plaque is a causative factor for oral disease, and thus its removal and control are important aspects of oral health maintenance 1,2. this plaque can lead to enamel demineralization3 and gingivitis 4. previous studies have shown that the rate of decalcification in orthodontic patients is higher than in patients without orthodontic treatment. white spots have been reported in as many as 50% of teeth treated with brackets and in up to 50% of orthodontic patients 5,6. (1)m.sc. student. department of orthodontics. college of dentistry. university of baghdad. (2)assistant professor. department of orthodontics. college of dentistry. university of baghdad. although various studies have evaluated fluoride treatments for their effects in reducing white spot formation associated with orthodontic treatment7, surprisingly only a few studies have assessed plaque prevention by antimicrobials 4,8,9. most of those studies that investigated plaque focused on hygiene aids 10-12. one reason for the limited number of studies of antimicrobial plaque control in orthodontic populations might be due to the lack of qualified, simple, and convenient measurement methods. most traditional plaque scoring systems applied to unbracketed dentitions, such as the löe and silness index,13 the turesky modification of the quigley and hein index14 or the navy index 15 are difficult to use in orthodontic populations. this is because they are based on a nonlinear (categorical) scale focused on plaque along the gum line; even after modifications, they lack sensitivity when applied to orthodontic populations. planimetry-based scales would probably be more appropriate for orthodontic patients, whose plaque accumulates in a variety of orientations driven by the presence of appliances. in recent years, several objective plaque evaluation methods with digital image analysis j bagh college dentistry vol. 25(2), june 2013 the effect of different orthodontics, pedodontics and preventive dentistry144 have been developed 16-18. this study was performed to show the different effect of chemical plaque control agents (chx, f) on plaque amount in orthodontic bands with different attachments. materials and methods the sample twenty patients were included in this study; from those who were attending the postgraduate clinic of orthodontic department in collage of dentistry/baghdad university according to their fitness to the following criteria: 1) patients age 18-25 included eleven females and nine males. 2) good general physical health 3) the dental requirement for inclusion was a malocclusion in which orthodontic treatment without teeth extraction was needed. 4) no history of any systemic disease. 5) no history of any oral habit. 6) good oral hygiene 7) the presence of well aligned adjacent teeth on both sides of the first permanent molar without spacing, caries or cl ii filling. 8) the patients had full set of upper and lower dentition excluding the third molars with no congenital missing or any abnormality in the form of dentition. 9) the patients should not take any antibiotic during the experimental study. 10) posterior or anterior cross bite should not be included in the sample. 11) the participants should be well educated so they can be motivated. materials and equipment 1) general dental materials and instruments 2) orthodontic material and instruments 3) orthodontic upper and lower 1st molar bands 4) biochemical test kit clinprocario l-pop (cclp) 5) oral hygiene aids 6) the digitizing and storage equipment and programs method participants were examined clinically, standard orthodontic records were obtained and oral hygiene status of the patients was determined. tooth separation for proper seating of orthodontic bands by elastomeric separators was done, three days later fixed appliance was placed and the patients were randomly divided into four groups of hygiene regimens where group a used chlorhexidine dentifrice, group b used fluoridated dentifrice, group c used chlorhexidine mouthwash along with chlorhexidine dentifrice and group d used chlorhexidine mouthwash in addition to the floutride dentifrice. the patients received special oral hygiene instructions included a detailed brushing protocol with a demonstration of the bass brushing technique. they were told to brush 3times a day for 2 minutes, using an amount of dentifrice that covers the entire head of the toothbrush; and to brush their teeth after snacks using the brush only. they were also asked not to use other oral hygiene products the next four weeks. the patients were checked two weeks later for their oral hygiene in terms of gingival index, and they were instructed to continue perform their hygiene regimens. after four weeks the experimental bands were removed and replaced by new ones. immediately following careful removal from patients' mouths through grasping the band from the attachment by the band remover pliers, the bands were cut out from the middle of the mesial and distal contact areas with metal scissors into two pieces then each piece was flattened out by grasping it from the free ends using adams pliers and pulled out, any contact with areas of interest were avoided. furthermore, this procedure took place in an antiseptic environment. the two pieces of the band were placed in a petri dish. the biofilm was stained with a biochemical test for lactic acid (clinprocario l-pop; 3m espe, seefeld, germany) figure 1. using this method, the biofilm was identified according to bacteria that produce lactic acid as a key metabolic factor, these being bacteria with a highly cariogenic potential. the bands were positioned on a millimeter paper, waiting for two minutes and photographed. the four areas of interest, each 2 mm in width, were defined and digitally marked with the cursor on each band: the mesial and distal regions of the buccal and lingual attachment. the software calculated the surface area of each marked area. the stained biofilm area was then marked within the four areas using a cursor and the area covered, and calculated by the software again. a ratio was computed from the calculated results, which revealed the quantity of biofilm in the specific areas of interest. (figure2) results the mean values of plaque ratios and standard deviation with different attachments on orthodontic bands in patients following different oral hygiene regimens were estimated in (table 1). the differences among the four groups of oral hygiene were not significant. side difference in j bagh college dentistry vol. 25(2), june 2013 the effect of different orthodontics, pedodontics and preventive dentistry145 means of plaque amount on the upper bands from the buccal aspect revealed that the means on the right side were higher than those on the left side in all groups of oral hygiene regimens except for group d where the mean on the right side was lower than that on the left distal to the attachment , although the differences were not significant, lingually button and the cleat on the right and left bands respectively revealed insignificant difference in all groups of hygiene protocols. on the lower bands buccally, the difference between double tubes on the right and left sides was higher on the right side than the left side in all of four groups, it was significant in 100% of the sample in group a, while 50% of the sample was significant in group b. while plaque amount on the lingual button were insignificantly higher than the lingual cleat. regarding arch differences on the right side, the plaque amount on the lower tripple tubes is insignificantly higher than that on the upper double tubes in all groups of hygiene regimens; this is also true for the lingual cleats. the double versus tripple tubes on the left side reveals insignificantly higher amount of plaque on the lower arch. in addition, lingual buttons also accumulated higher amount of plaque on the lower than the upper. discussion studies on plaque control strategies in orthodontic populations are limited. this might be caused by difficulties in the quantitative evaluation of dental plaque because the teeth have various levels of bracket coverage, and different tooth sizes and malocclusions, making the traditional categorical indices complex. the other approach is measurement of the percentage area covered by plaque using digital image analysis of photographs19. digital photographs of disclosed teeth greatly facilitate such analysis. direct digital measurement of percentage plaque coverage is more complex but is likely to prove more valid and more reproducible than categorical indices. the advantages of a photograph are that it can be assessed at leisure, is a permanent record, and can be viewed on multiple occasions, enabling assessment of reproducibility, which was found to be excellent. it should be noted that area measurement is not completely immune from an element of subjective judgment and other potential sources of error. these potential errors are probably small in relation to those associated with visual estimation for a categorical index, but they are nevertheless a factor. in addition, digital measurement requires longer time and greater technical complexity. the results of the present study revealed that all the chemical plaque control agents used were of no significant different effect. furthermore, the use of chx mouth wash as an adjunct to the chx or fluoridated tooth pastes had no significant additive influence on the quantity of plaque. this is in agreement with other study which investigated the influence of 0.12% and 0.2% chlorhexidine gluconate on both dental plaque accumulation and salivary s. mutans and showed that there is no significant difference between them20. previous study investigated the effect of 40% chlorhexidine varnish during a 30-month period. they also found that 40% chlorhexidine varnish did not decrease the number of cariogenic bacteria21. in contrast to this study, some previous studies suggested that higher concentrations of antimicrobial agents and multiple treatments extend the time of effectiveness against s mutans and dental plaque22. investigation of varnishes with high concentrations of chlorhexidine (40% chlorhexidine) revealed a significantly stronger reduction of s. mutans in plaque and saliva compared to low-concentration varnish during a 2-week period which does not agree with this study 23. the germicidal effect of fluoride on cariogenic bacteria (such as s mutans and lactobacilli) is the inhibition of glycolysis. in addition, fluoride acidifies the interior of cells and inactivates some enzymatic metabolic processes 24. the use of fluoridated tooth paste in combination with chx mouthwash in this study had no significant effect on the quantity of cariogenic plaque, this finding goes along with the result of other study25 which evaluated the effect of 0.3 % triclosan toothpaste with and without flouride on enamel demineralization and found that in combination with fluoride, triclosan has no additional protective effect against demineralization. flouride did not increase the efficacy of the toothpastes, probably because a possible antimicrobial effect was not complementary or additive to the effect of other antimicrobial compounds of the toothpaste or mouth wash. contrary to this study, ahumadoostenga25showed that the effects of sodium fluoride (naf) and chlorhexidine mouth rinse increase with different concentrations depending on the species of lactobacilli. furthermore, juric26 disagree with this study when j bagh college dentistry vol. 25(2), june 2013 the effect of different orthodontics, pedodontics and preventive dentistry146 observed that professional tooth-cleaning and the usage of chewing gum with xylitol and fluoride on a daily basis could be helpful in reducing cariogenic bacteria. this finding is in contrast to the result of gorelick4when the incidence of white spot formation was measured on banded or bonded teeth in a clinical setting. the lowest incidence was found to be in the lingual surfaces of lower canines, and the highest on labial areas of maxillary incisors. moreover, this study showed that the right side has higher amount of plaque than the left side, although the difference is not significant. it appeared that the plaque accumulated on the right side more than the left side, which is not uncommon finding that the right side has a higher prevalence of white spot lesions following orthodontic treatment than the left as shown by gorelick4. according to the results of the present study, the plaque amount was insignificantly higher on the lower arch. the presence of undercuts and tongue interference with performing proper cleansing in the lower arch may probably result in this difference. also the lower teeth are more exposed to the salivary flow which contains calcium and other minerals and carry the biopolymers which are essential for early pellicle formation and food shedding during mastication, facilitating microbial attachment. this would also agree with other studies 27,28 that have found a higher amount of plaque on the right side of right-handed tooth brushers than on the left. the difficulty encountered during brushing on the right side may attribute to plaque accumulation on it. most of the participants in this study were right handed. consequently, it would be ideal to recommend chlorhexidine as a dentifrice, thus combining mechanical cleaning and antiplaque benefit with no added discomfort for patients. references 1. shibly o, rifai s, zambon jj. supragingival dental plaque in the etiology of oral diseases. periodontol 2000 1995; 8: 42–59. 2. fejerskov o, kidd eam. dental caries: the disease and its clinical management. oxford: blackwell munksgaard; 2003. 3. ogaard b, seppä l, rölla g. professional topical fluoride applications – clinical efficacy and mechanism of action. advances in dental research 1994; 8: 190–201. 4. ogaard b, alm aa, larsson e, adolfsson u. a prospective, randomized clinical study on the effects of an amine fluoride/stannous fluoride toothpaste/mouthrinse on plaque, gingivitis and initial caries lesion development in orthodontic patients. eur j orthod 2006; 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demineralization model. j antimicrob chemother 2000; 45:153-158. 26. ahumada ostengo mc, wiese b, nadir-macias me. inhibitory effect of sodium fluoride and chlorhexidine on the growth of oral lactobacilli. can j microbiol 2005; 51(2): 133–140. 27. juric h, dukic w, jankovic b, karlovic z, pavelic b. suppression of salivary streptococcus mutans and lactobacilli by topical caries preventive agents. cent eur j public health 2003; 11: 219–222. 28. addy m, griffiths g, dummer p, kingdom a, shaw wc. the distribution of plaque and gingivitis and the influence of tooth brushing hand in a group of southwales 11–12-year-old children. j clin periodontol 1987; 14: 564–72. 29. addy m, dummer pm, hunter ml, kingdon a, shaw wc. the effect of tooth brushing frequency, tooth brushing hand, sex and social class on the incidence of plaque, gingivitis and pocketing in adolescents: a longitudinal cohort study. community dent health 1990; 7(3): 237–47. table 1: means, standard deviations and standard errors of the plaque amount ratio with different attachments in different oral hygiene groups. groups descriptive statistics group differences chx dentifrice fluoridated dentifrice chx dentifrice+chx mw fluoridated dentifrice+ chx mw variables mean s.d. s.e. mean s.d. s.e. mean s.d. s.e. mean s.d. s.e. kkw p-value u pp er ri gh t b m 29.49 8.70 3.89 35.55 9.02 4.04 30.37 8.89 3.98 28.63 8.55 3.82 1.98 0.575 (ns) d 37.56 13.65 6.11 29.16 3.89 1.74 31.09 11.94 5.34 27.16 6.87 3.07 1.90 0.592 (ns) l m 28.46 9.60 4.29 24.97 3.49 1.56 24.51 7.02 3.14 26.44 7.39 3.30 0.60 0.894 (ns) d 30.99 10.02 4.48 35.10 9.87 4.41 34.56 15.77 7.05 27.22 11.84 5.30 1.69 0.638 (ns) u pp er le ft b m 28.05 0.85 0.38 25.87 5.80 2.59 25.48 6.34 2.84 25.73 5.64 2.52 2.06 0.559 (ns) d 20.67 4.31 1.93 22.70 7.47 3.34 29.15 3.39 1.52 28.47 6.66 2.98 7.06 0.070 (ns) l m 26.17 10.91 4.88 33.18 4.42 1.97 30.40 8.72 3.90 26.41 8.88 3.97 2.10 0.552 (ns) d 20.00 10.04 4.49 33.50 12.93 5.78 31.11 14.86 6.64 33.69 14.29 6.39 2.58 0.459 (ns) l ow er ri gh t b m 43.50 9.92 4.44 34.53 4.40 1.97 33.42 5.28 2.36 31.84 4.68 2.09 6.49 0.090 (ns) d 34.86 10.22 4.57 37.80 5.37 2.40 30.93 5.82 2.60 35.97 5.86 2.62 3.36 0.339 (ns) l m 30.94 5.57 2.49 31.87 5.70 2.55 31.82 6.85 3.06 33.34 6.97 3.12 0.78 0.854 (ns) d 36.48 12.30 5.50 36.96 4.33 1.94 31.43 4.93 2.21 36.42 4.71 2.11 3.22 0.358 (ns) l ow er le ft b m 38.39 11.21 5.01 24.51 8.82 3.94 27.61 3.22 1.44 29.07 9.10 4.07 5.72 0.126 (ns) d 30.63 7.88 3.53 25.75 8.44 3.77 28.70 8.22 3.68 30.92 6.21 2.78 1.74 0.627 (ns) l m 32.00 7.91 3.54 26.28 5.39 2.41 26.56 5.70 2.55 26.30 6.04 2.70 2.65 0.448 (ns) d 28.76 5.63 2.52 35.32 8.77 3.92 32.36 7.82 3.50 34.61 6.47 2.89 3.79 0.285 (ns) ns = p>0.05 figure 2: orthodontic band with the four areas of interest (1) mesial of the attachment (2) distal of the attachment (3) mesial of the attachment (4) distal of the attachment figure 1: biochemical test kit clinprocario l-pop (cclp) (1) cclp swab containing sucrose (2) color indicator (3) l-pop blisters that contains lactate dehydrogenase enzyme (4)control swabs. j bagh college dentistry vol. 25(2), june 2013 the effect of different orthodontics, pedodontics and preventive dentistry148 means of plaque amount (%) bands figure 3: plaque amount with different attachments in different oral hygiene groups. maha.doc j bagh college dentistry vol. 26(4), december 2014 assessment of serum oral and maxillo-facial surgery and periodontics 141 assessment of serum levels of mmp-8 and hs crp in chronic periodontitis patients in relation to atherosclerotic cardiovascular disease zainab j. raheem, b.d.s. (1) maha a. ahmed, b.d.s., m.sc. (2) abstract background: periodontitis and atherosclerosis cardiovascular disease are chronic inflammatory diseases which are highly prevalent. during the last two decades, there has been an increasing interest in the impact of oral health on atherosclerosis and subsequent cardiovascular disease. the aims of the study were to evaluate the periodontal health status in study groups (atherosclerotic cardiovascular disease patients with chronic periodontitis and patients having chronic periodontitis),to estimate the serum levels of matrixmetalloproteinase-8(mmp-8) and high sensitive creactive protein(hs crp) in study and control groups and compare between them. also,test the correlation between the serum levels of mmp-8 and hs crp with clinical periodontal parameters at each study group subjects, materials and methods: eighty subjects, males and females were included in this study with age range (3550) years old, they were divided into study groups [ath+cp group: atherosclerotic cardiovascular disease& chronic periodontitis group (30 patients), cp group: chronic periodontitis group (30 patients)] andcontrol group: (20 systemically healthy subjects, have healthy periodontium). periodontal health status was determined by measuring the following clinical periodontal parameters (plaque index (pl.i), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal)).serum levelsof (mmp-8and hs crp) were determined by mean of elisa. results: the results showed that the mean values of clinical periodontalparameters (pl.i, gi, ppd and cal), were higher in the ath+cp group than in the cp group with significant differences except in pl.i there was no significant difference. a higher percentage of score 1of bop sites demonstrated by cp groupthan in ath+cp group with highly significant difference.the levels of serum (mmp-8 and hs crp) were higher in ath+cp groupwhen compared with cp group and control group, with highly significant differences between all pairs of study and control groups.regarding the correlation between serum levels of (mmp-8 and hs crp) and clinical periodontal parameters, were positive correlation in both study groups. conclusion: the present results my provide evidence that chronic periodontitis may contribute to the inflammationassociated to atherosclerotic process keywords: atherosclerosis cardiovascular disease, chronic periodontitis, matrix metalloproteinase-8, hs c-reactive protein. (j bagh coll dentistry 2014; 26(4):141-146). الخالصة خالل العقدین الماضیین كان ھناك اھتمام متزاید في تاثیر صحة الفم على . االنتشار یعد مرض النساغ ومرض التصلب العصیدي من االمراض االلتھابیة المزمنة الواسعھ:لخلفیة ا التصلب العصیدي ومرض القلبي الوعائي جموعھ التصلب م 1ج(تم تقسیمھم الى مجموعتي الدراسة . سنة)50-35(شخصا ذكورا واناثا ادرجوا في ھذه الدراسة تتراوح اعمارھم بین 80:المواد وطرائق العمل ,االشخاص یملكون انسجھ ماحوا االسنان صحیة / شخصا اصحاء سریریا 20(مجموعھ الضابطھ 3ج) مریضا30(مجموعھ النساغ المزمن 2وج) مریضا30(العصیدي لدیھم النساغ المزمن مؤشر ,مؤشر النزف عند التسبیر ,مؤشر التھاب اللثھ ,فیحة الجرثومیة مؤشر الص(قدرت الحالة لالنسجة ماحول االسنان عن طریق قیاس موشرات ماحول االسنان السریریة التالیة ). و البروتین االرتكاسي العالي الحساسیھ باستخدام تقنیة مقایسة االنزیم 8تم تحدید مستویات المصل لكل من المصفوفھ الفلزیة ). عمق الجیوب بالظافة الى فقدان االنسجة الرابطھ سریریا المرتبط الممتز المناعي اعلى لدى ) مؤشر عمق الجیوب بالظافة الى فقدان االنسجة الرابطھ سریریا, ,مؤشر التھاب اللثھ ,مؤشر الصفیحة الجرثومیة ((اظھرت النتائج ان قیم المتوسط الحسابي لكل من :النتائج و البروتین االرتكاسي العالي الحساسیھ 8المصل لكل من من المصفوفھ الفلزیة مستویات. مع فروقات معنویة عالیة 1من ج 2ھنالك نسبة عالیھ لمناطق التسبیر عندج. 2من ج 1ج فیما یخص العالقھ بین مستویات المصل لكل من من . مع وجود فروقات معنویة عالیة بین كل ثنائي من مجموعات الدراسة والضابطھ 3وج 2عند مقارنتھا مع ج 1كانت اعلى عند ج ین االرتكاسي العالي الحساسیھ ومؤشرات ماحول االسنان السریریھ كان ھناك ارتباط معنوي طردي و البروت8-المصفوفھ الفلزیة وتشیر الى ان مرض النساغ قد یلعب دورھاما في االلتھاب المصاحب . النتائج الحالیة قد توفر دلیل على ارتباط بین مرض النساغ المزمن ومرض التصلب العصیدي :االستنتاج العصیديلمرض التصلب introduction periodontitis is described as a multifactorial, irreversible and cumulative condition initiated and propagated by both bacteria and host factors and is also associated with various systemic conditions (1). periodontal disease (pd) and atherosclerosis seemed to share a similar pathway and that certain individuals might be more likely than others to respond to higher levels of inflammatory stimuli. these factors lead to exce (1) master student. department of periodontics. college of dentistry. university of baghdad. (2) assistant professor. department of periodontics. college of dentistry .university of baghdad. ssive production of cytokines and other inflammatory mediators, enhancing the development of periodontal and arterial cell wall lesions (2). mmp-8 plays an important role in the pathogenesis of periodontal diseaseand it is catalytically the most competent proteinase to initiate type i collagen and extracellular matrix degradation associated with periodontal tissue destruction leading to tooth loss (3). mmp -8 has also been suggested to be implicated in atherosclerosishence, it degrades type i collagen, which is a major component of the fibrous cap, also mmp-8 possesses proteolytic activity on some non-matrix proteins such as angiotensin i (4). j bagh college dentistry vol. 26(4), december 2014 assessment of serum oral and maxillo-facial surgery and periodontics 142 crp, the classic acute-phase, is sensitive objective marker of inflammation, tissue damage and infection.the american heart association recommended hs crp measurements as a part of the assessment of patients with a moderate risk of coronary heart disease (5). circulating oral bacteria and lipopolysaccharide (lps) are also able to stimulate hepatocytes to secrete crp (6). the purpose of this study were to evaluate the periodontal health status in study groups (ath+cpgroupand cp group),to estimate the serumlevels of mmp-8 and hs crp in study and control groups and compare between them. also, test the correlation between the serum levels of mmp-8 and hs crp with clinical periodontal parameters at each study group. subjects, materials and methods eighty (80) subjects, males and females aged (35-50) years old were recruited in this study. they were from attendants seeking treatment in iraqi center for heart diseases in ghazy alharery hospital and patients were seeking periodontal treatment in department of periodontics at teaching hospital college of dentistry, baghdad university.all the individuals were informed about the purpose of this investigations andconsented to its protocol. the subjects were divided into study groups and control group. study groups include: • ath+cp group consists of thirty patients diagnosed to have chronic periodontitis and atherosclerosis cardiovasculardisease (ascvd)according to catherization and not more than one year and under anticoagulant drugs (clopidogrel). • cp group consistsof thirty patients diagnosed to have chronic periodontitis and didn’t have history of any systemic diseases.chronic periodontitis in patients was defined as the presence of at least four sites with ppd of ≥ (4) mm and clinical attachment loss of ≥ (1-2) mm, this made according to the international classification system for pd (7). • control group consistsof twentypatients with clinically healthy periodontiumthis was defined by gi scores<0.5 (8) with no pockets or clinical attachmentloss and no history of any systemic diseases. exclusion criteria included: 1. any patient had history of other chronic, systemic diseases with known associations with pd as diabetes mellitus, rheumatoid arthritis, etc. 2. smoker. 3. medication (antiinflammatory or antimicrobial therapy) within previous 3 months 4. periodontal treatment within previous 3 months. 5. pregnancy 6. contraceptive pills. clinical periodontal parameters examination was performedby using michigan o periodontal probe on four surfaces (mesial, buccal/ labial, distal and lingual/ palatal) of all teeth except third molar, all subjects must have at least 20 teeth. the collected data include: 1. assessment of soft deposits by the plaque index system (pl.i) according to silness and loe (9). 2. assessment of gingival inflammation by the gingival index system (gi) according to löe (8). 3. assessment of gingival bleeding on probing (bop): periodontal probe inserted to the bottom of the gingival crevice or pocket and is moved gently along the root surface. if bleeding occur within 30 seconds after probing, the site was given as score (1), and a score (0) for the non-bleeding site (10). 4. assessment of probing pocket depth (ppd): it's defined as the distance from gingival margin to the most apical penetration of the periodontal probe inserted into the gingival crevice or periodontalpocket (7). 5. assessment of clinical attachment level (cal): it is the distance from the cementoenamel junction to the location of the inserted probe tip (bottom of gingival crevice or periodontal pocket (7). after the clinical periodontal parametersexamination, 5ml venous blood was collected from study and control groups. after centrifusion, serum samples were kept frozen at ( 20) °c. serum levels of (mmp-8 and hs crp) were determined by mean ofenzyme linked immunosorbent assay (elisa).elisa kit (96wells) for quantitative determination of serum mmp-8 of hcusa bio.elisa kit (96-wells) for quantitative determination of serum hs crp of de medi tec. statistical analysis was assessed using t-test, chi-square test, anova test, lsd and pearson's coefficient of correlation. results the current results revealed that mean values of (pl.i, gi, ppd and cal) were higher in ath+cp group than the cp group, with j bagh college dentistry vol. 26(4), december 2014 assessment of serum oral and maxillo-facial surgery and periodontics 143 significant differences between the two study groups except for the mean value of pl.i there was no statistical significant difference. the percentage of score 1 of bop sites was higher in cp group than the ath+cp group with highly significant difference.the statistical analysisof clinical periodontal parameters forath+cp group and cp group are summarized in table (1). table (2) showed thatthe serum levels of mmp-8 and hs crp were higher in ath+cp group followed by cp group then the control group, the mean values with std. dev. for mmp-8 were(76±4.1, 67.7±3.1,27.1 ±4.8 respectively) and for hs crp were (5.087±1.613, 1.013± 2.113 , 0.558±0.138 respectively) with highly significant differences (p<0.001) among all the groups. regarding both immunological parameters inter groups' comparisons of mean values of serum mmp-8 as well as hs crp between all pairs of the study and control groups demonstrated highly significant differences, as shown in table (3). in ath+cp group there was weak positive correlation between gi with serum mmp-8 levels at p<0.05. while there were highly significant, strong positive correlations between serum mmp8 levels and each of (pl.i, bop, ppd and cal) at p< 0.01. for cp group, there were weak positive correlations between serum mmp-8 levels with pl.i ,gi and ppd, on the other hand,highly significant, strong positive correlations were observed between serum mmp8 levels with bop and cal at p<0.01. it was demonstrated thatin ath+cp group weak positive correlation between serum hs crp levels with pl.i at p<0.05 as well as weak positive correlations with gi, bop and ppd at p>0.05 in ath+cp group,whilehighly significant strong positive correlation was observed between serum hs crp levels with cal at p<0.01.in cp group highly significant strong positive correlations were revealed between serum hs crp levels with (gi, bop, ppd and cal) at p<0.01, while the correlation between serum hs crp levels and pl.i, was weak positive at p<0.05, as shown in table (4). table 1: statistical analysis of mean values of clinical periodontal parameters (pl.i, gi, bop, ppd and cal) for the ath+cp group and cp group with comparison of significance bop cal ppd gi pl.i groups score 0 score 1 % no % no s.d. mean s.d. mean s.d. mean s.d. mean 43.5 1155 56.5 1521 ±0.82 4.7 ±0.41 5.04 ±0.39 1.94 ±0.28 1.83 ath+cp 35.5 1126 60.5 1722 ±0.82 4.2 ±0.62 4.76 ±0.23 1.73 ±0.29 1.73 cp 7.478 chi 2.23 2.018 2.523 1.32 t-test hs s s s ns sig ns: non-significantat p>0.05 .s : significant at p<0 .05. hs : highly significant at p<0.001 table2: statistical analysis of mean values of serum (mmp-8 and hs crp) for ath+cp group, cp group and control group with comparison of significance hs crp mmp-8 groups s.d. mean s.d. mean ±1.613 5.087 ±4.1 76 ath + cpgroup ±1.013 2.113 ±3.1 67.7 cp group ±0.138 0.558 ±4.8 27.1 control group 98.928 965.094 f-test hs hs sig. hs : highly significant at p<0.001 table 3: inter groups comparisons of the mean values of serum (mmp-8 nm/ml and hs crp mg/l) between all pairs of the ath+cp group, cp group and control group hs crp mmp-8 groups sig s.e. mean difference sig s.e. mean difference hs 0.30 2.974 hs 1.037 8.165 ath+cpxcp hs 0.33 4.528 hs 1.037 48.913 ath+cpxcontrol hs 0.33 1.554 hs 1.159 40.747 cpxcontrol hs: highly significant at p<0.001 j bagh college dentistry vol. 26(4), december 2014 assessment of serum oral and maxillo-facial surgery and periodontics 144 table 4: pearson's correlation coefficients among serum levels of (mmp-8and hs crp) and clinical periodontal parameters in ath+cp group and cp group cal ppd bop gi pl.i statistical analysis groups immunological parameters 0.78 0.70 0.692 0.37 0.48 r ath+cp mmp-8 0.000 0.000 0.000 0.03 0.007 p-value 0.709 0.323 0.69 0.252 0.13 r cp 0.000 0.082 0.000 0.179 0.482 p-value 0.507 0.284 0.036 0.245 0.365 r ath+cp hs crp 0.004 0.128 0.852 0.193 0.047 p-value 0.816 0.490 0.505 0.555 0.425 r cp 0.000 0.006 0.004 0.001 0.019 p-value discussion the mean values of (pl.i , gi,ppd and cal)were higher in ath+cp group than cp group which could be explained in that plaque is the major etiological factor in periodontitis and it is expected to be accumulating more in chronic periodontitis because the presence of dental plaque is the main clinical finding for chronic periodontitis and it is coincide with the severity and the time beingof the disease, another possible explanation of such results as the hospitalized atherosclerotic cardiovascular disease patients neglect the oral hygiene measures and didn't brush their teeth regularly, so that more gingival inflammation could be seen in ath+cp group.bacterial dental plaque elaborate various compounds(toxins,enzymes and h2s), that elicit an inflammatory response that is protective but also is responsible for loss of periodontal tissue, pocket formation, loosening and loss of teeth(11).also dyslipidaemia in patients of ath patientshad a negative influence on all clinical measures of periodontal health status e.g. (greater clinical attachment loss, ppd and tooth loss) (12). the percentage of score 1 of bop sites demonstrated by cp group was higher when compared with ath+cp group, this result may be due to the presence of more inactive sites during clinical periodontal examination of ath+cp group ,also more number of examining sites in cp group than ath+cp.theresultsobtained from the present study were similar tothat reported by other investigators (11,13,14). mmp-8 can initiate the digestion of type i collagen,whichis the major structural element and load-bearing molecule that provides tensile strength to the fibrous cap of an atherosclerotic lesion (15). in addition to the inflammation caused by atherosclerosis, the sources of mmp-8 found in serum by the host response to the insult of periodontal pathogens involves local increases of mmp-8 level, which may most probably leak to circulation through inflamed periodontal tissues (16). mmp-8 is the most competent proteinase associated with periodontal tissue destruction leading to tooth loss (3). the results obtained from the present study regarding serum levels of mmp-8 were similar to that reported by other studies (17,18). hs crp is a predictive marker for cardiovascular disease .crp arise in the atheromatous lesions and reflect the extent of inflammation that predisposes to plaque instability (19). in patients with chronic periodontitis, periodontal pathogens and bacteremia occurs that initiates a systemic antibody response and the activation of the hepatic acute-phase response (20). numbers of studies were agreed with results of present study regarding serum levels of hs crp (15,21-23). regarding positive correlation between serum levels of mmp-8 and clinical periodontal parameters, might be caused by the potential inflammatory effect through the dental plaque (18). mmp-8 concentration correlated especially with the depth of the periodontal pocket in bleeding sites. this may in fact support the value of mmp-8 as an indicator of progressive periodontitis with advancing attachment,in addition to that neutrophils which are major cellular sources of mmp-8 are also present in an increased concentration in periodontal tissues in patients with periodontitis. furthermore, bacterial proteinases present in microbial plaque can activate production of mmp-8 by neutrophils (24). numbers of studies showed there was positive correlation between serum levels of mmp-8 and clinical periodontal parameters (11,18,25). the possible explanation of the positive correlations between serum levels of hs crp and clinical periodontal parameters, as periodontal diseases are infections characterized by inflammation and destruction of the supporting tissues of the affected teeth. gram negative anaerobes are present in large numbers in sub-gingival plaque in periodontal pockets,these periodontal pathogens create toxic lps, which is released within the pockets and penetrates into the tissues, where the lps interacts with macrophages to stimulate the release of inflammatory mediators. these inflammatory markers cause vasodilation and j bagh college dentistry vol. 26(4), december 2014 assessment of serum oral and maxillo-facial surgery and periodontics 145 destruction of the periodontal ligaments, activate fibroblasts and osteoclasts for tissue destruction and bone resorption (26). low levels of bacteraemia, endotoxins derived from gram negative microorganisms and other bacterial components may provide a stimulus for systemic inflammatory responses such as increased production of crp due to activation of the cascade of inflammatory cytokine production by monocytes and other cells in the periodontal tissue (27). number of studies agreed with our results (14, 26, 28), while ide et al. reported there were no correlations between serum levels of hs crp and clinical periodontal parameters (29,30). as conclusion; the present results my provide evidence of association between chronic periodontitis and atherosclerotic cardiovascular disease and suggest that periodontitis may play important role in activation and triggering immune response and patients with chronic periodontitis at risk of atherosclerosis and cardiovascular disease. references 1. bensley l, vaneenwyk j, ossiander em. associations of self-reported periodontal disease with metabolic syndrome and number of self-reported chronic conditions. preventing chronic disease 2011; 8(3): a50. 2. beck jd, slade g, offenbacher s. oral disease, cardiovascular disease and systemic inflammation. periodontology 2000, 2000; 23:110-20. 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(ivsl). 18. ehlers v, willershausen i, kraft j. gingival crevicular fluid mmp-8concentrations in patients after acute myocardial infarction. head & face medicine 2011; 7: 1. 19. gershov d, kim s, brot n, elkon kb. c-reactive protein binds toapoptotic cells, protects the cells from assembly of the terminal complement components, and sustains an anti-inflammatory innate immune response: implications for systemic autoimmunity. j exp med 2000; 192: 1353–64. 20. persson gr, ohlsson o. chronic periodontitis, a significant relationship with acute myocardial infarction. european heart j 2003; 24: 2108–15. 21. nikolaos a. chrysanthakopoulos and panagiotis. clinically classified periodontitis and its association in patients with pre-existing coronary heart disease. j oral diseases 2013; 24: 3736-9. 22. haba d, teslaru s, ungureanu d, hodrog d, et al. evaluation of serum and gingival crevicular fluid creactive protein and il-6 levels in patients with periodontitis and transient ischemic attacks. rom j morphol embryol 2011; 52(4):1243-7. 23. uddarraju s, praveen g, anitha a, zabirunnisa m. association between chronic periodontal disease and cardiovascular risk factor c-reactive protein in blood. webmed central dentistry 2014; 5(2):1690-99. 24. päivi m. the scientific basis and development of a matrix metalloproteinase (mmp) -8 specific chair-side test for monitoring of periodontal health and disease from gingival crevicular fluid. a ph.d. thesis, department of oral and maxillofacial diseases, university of helsinki, 2006. 25. kraft-neumärker m, lorenz k, koch r, hoffmann t. full-mouth profile of active mmp-8 in periodontitis patients. j periodontal res 2012; 47(2):121-8. j bagh college dentistry vol. 26(4), december 2014 assessment of serum oral and maxillo-facial surgery and periodontics 146 26. pejcic a, kesi l, milasin j. association between periodontopathogens and crp levels in patients with periodontitis in serbia. j dent res dent clin dent prospects 2011; 5(1):10-16 27. offenbacher s, beck jd, moss k, et al. results from the periodontitis and vascular events (pave) study: a pilot multicentered, randomized, controlled trial to study effects of periodontal therapy in a secondary prevention model of cardiovascular disease. j periodontol 2009; 80: 190-201. 28. al-ghurabei b. evaluation of serum anti-cardiolipin antibody, hs-crp and il-6 levels in chronic periodontitis as possible risk factors for cardiovascular diseases. j bagh coll dentistry 2012; 24:161-5. 29. ide m, mcpartlin d, coward py, crook m, lumb pm wilson rf. effect of treatment of chronic periodontitis on levels of serum markers of acute phase inflammatory and vascular responses. j clinperiodontol, 2003; 30:334-40. (ivsl). 30. baker a, al-safi a. correlation between biochemical analysis and periodontal health status and tooth loss in chronic renal failure patients. j bagh coll dentistry 2012; 24:100-5. zainab f.doc j bagh college dentistry vol. 25(3), september 2013 x-ray diffraction restorative dentistry 62 x-ray diffraction and biocompatibility of glass ionomer cement reinforced by different ratios of synthetic hydroxyapatite mohammed r. al.jabouri, b.d.s., m.sc., ph.d. (1) zainab m. abdul-ameer, b.d.s., m.sc. (1) abstract background: this study was done to assist x-ray diffraction and biocompatability of glass ionomer cement reinforced by different ratios of hydroxyapatite. materials and methods: the powder of glass ionomer cement reinforced by different ratios of hydroxyapatite were used to get x-ray diffraction pattern by x-ray diffraction machine, while for biocompatibility test, a polyethylene tubes containing glass ionomer cement reinforced by different ratios of hydroxyapatite were implanted on the dorsal submucosal site of rabbit's tissues and histological slide were prepared for histopathological study. results: x-ray diffraction test showed that all elements of glass ionomer cement reinforced by different ratios of hydroxyapatite were react with each other and all the final products none crystalline in nature with small amount of hydroxyapatite present unreacted may be act as cores for final reacted elements. the histological test showed mild irritation to rabbit's tissues by glass ionomer cement reinforced by different ratios of hydroxyapatite, this irritation subsided with time. conclusions: there is chemical reaction of all elements of glass ionomer cement reinforced by different ratios of hydroxyapatite and new final products were results .also glass ionomer cements reinforced by different ratios of hydroxyapatite were biocompatible with rabbit’s tissues. key words: x -ray diffraction, biocompatibility, glass ionomer cement. (j bagh coll dentistry 2013; 25(3):62-68). introduction glass ionomer cement was first introduced to the dental profession by wilson and kent in 1972. their main characteristics are an ability to chemically bond to enamel and dentine with insignificant heat formation or shrinkage; biocompatibility with the pulp and periodental tissues, fluoride release producing a cariostatic and antimicrobial action, less volumetric setting contraction and a similar coefficient of thermal expansion to tooth structure. these advantages have made them successful as luting cement and lining materials. however, as a restorative material, their sensitivity to moisture and low mechanical strength and wear resistance make them the least durable. this may be adequate for primary teeth because they will exfoliate in a number of years.1,2 when the powder and liquid in conventional glass ionomer are mixed together, an acid-base reaction occurs between the polyalkenoate acid and ion leachable glass, resulting in a plastic paste which then hardens to a sold mass. the final set structure is a complex composite of the original glass particles sheathed by a siliceous hydrogel and bonded together by a matrix phase of hydrated fluoridated calcium and aluminum polyacrylate .3, 4 while gics have been used successfully for over 30 years in dentistry, there are still concerns regarding gic biocompatibility in non-dental applications. (1)assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. in particular, al3+ release has been associated with poor local bone mineralization and local neurotoxicity .5 numerous cell culture studies of cytotoxicity have reported cell inhibition by specific gic compositions, and brook and hatton reviewed this work in 1998 .6 it appeared that the in vitro toxicity of gics was due to a complex mechanism based on both ion release (in particular, al3+ and f-) and ph effects .7 early animal studies of gic bone cements provided evidence of good biocompatibility. 8 in this study we assist the x-ray diffraction of glass ionomer cement reinforced by different ratios of hydroxyapatite and its biocompatability with rabbit’s tissues. materials and methods preparation of experimental cement: a powder of glass ionomer cement (medicem; promedica; neumonster; germany) was mixed with different ratios (10%, 15%, 20%, 25%, 30% by weight) of hydroxyapatite then the mixed powder was applied in agate machine for half an hour and hour for grinding and to get homogenous mixture (better distribution of hydroxyapatite particles throughout the glass ionomer powder) while the liquid of glass ionomer cement remained unchanged. x-ray diffraction test: a sample of experimental materials were prepared to undergo this test by mixing the j bagh college dentistry vol. 25(3), september 2013 x-ray diffraction restorative dentistry 63 experimental powder and liquid materials and preparation of a cylindrical specimen by using a stainless steel mould constructed according to ada specification no.6 then the sample were pulverized and exposed to cukα radiation by using mn filter, the values of diffraction will be measured and spacing will be calculated according to bragg`s equation: 2d=λ /sinθ where: d: spacing (distance), λ : is the wavelength of cukα radiation θ: is the diffraction angle using the value 1.54aº for the wavelength of cukα radiation, the figures of spacing (d) will be calculated and compared with astm standard table to detect the crystal components in the set materials. histopathological study: biocompatibility test was carried out on the rabbits by submucosal implantation of the control group (glass ionomer cement) and experimental groups {glass ionomer cement reinforced by different rations of hydroxyapatite only (10%, 20% and 30% was used for this test)} by using polyethylene tube as a carrier. females rabbits weight 2-2.5kg was used in this study. the rabbits were divided into three groups according to period of implantation of the polyethyline tubes (3, 10 and 21 days). each rabbit has received two implants submucosal on the dorsal position (in order not to get trauma on the implanted site during movement of the rabbits). anesthesia: general anesthesia was performed by intramuscular injection of a mixture of 88mg/kg of body weight of ketamine chloride (50gm/ml) and 10 mg/kg body weight of xylazin (2%). sterilization: the sterilization of the polyethylene tube was performed as follows athe tubes were immersed in pure ethyl alcohol for 15 minutes. bthen the tubes were washed with normal saline solution. cautoclaving the tubes for half an hour at 1000c was the last step of sterilization the polyethylene tube. all the instruments that were in contact with the rabbits were pre-sterilized by autoclaving. preparation of the implants: the polyethylene tubes of 0.5mm internal diameter and 1mm external diameter were loaded with cement materials after mixing , and cut to pieces of 5mm in length(a negative pressure were used to easy the loading the base materials by sucking the other end of the tube by manual sucker). preparation of the implanted site: the rabbit was anesthetized by intramuscular injections then the anesthetized rabbit was placed on its abdominal side on a sterilized surgical board. the dorsal skin of the intended implantation area was shaved and disinfected by povidone iodine solution, the area was located 5-6 cm from the center of the dorsal side toward the tail, where it was observed to be the most difficult place to be scratched by the animal itself. implantation of the base materials: under the aseptic conditions, two incisions of approximately 10mm in length were made through the skin, one on each side of the dorsal side. the submucosal tissue was opened by blunt dissection, then the polyethelene tubes filled with cement materials were held from the middle by a straight tweezers and inserted at the implanted site at least 2cm from the line of the incision after the implantation of each tube the wounds were sutured and the skin was scrubbed again with povidon iodion disinfectant. animals grouping: the rabbits were grouped for three time intervals of three days, ten days and three weeks (21 days). euthanasia: the rabbits of a time period were sacrified, each rabbit was injected intra-muscular with large dose of anesthetic ketamine chloride and xylesin. preparation of histological section: the tubes were removed with the tissue, which was cut out in rectangular pieces to facilitate directional embedding and correct sectioning, then were immersed in 10% buffered formalin. the tissue was fixed and processed for parafin wax embedding, serial sections were cut to a thickness of 8μm by a microtome. one of every 10 slices was taken and placed in a water bath and then placed on a slide, which was taken to an oven at 40oc to adhere the slice to the slide. the slide was placed in xylol to remove the paraffin surrounding the tissue. the slide was placed in a bath containing haematoxelin and eosin stain and was left for 10 minutes to stain the tissue. the slide was removed from staining bath, rinsed with distilled water and a glass cover was luted on the stained tissue with canada balsam. slides examination: each slide was examined under light microscope at magnification of 12.5x and 20x to evaluate the intensity and degree of inflammatory reactions around each tube end, and the subsequent tissue healing at the sites of implantation. slides were examined with aid of specialist in oral pathology, using double blind technique. j bagh college dentistry vol. 25(3), september 2013 x-ray diffraction restorative dentistry 64 results ax-ray diffraction test: x-ray diffraction test was performed on the following 1for the hydroxyapatite, powder of glass ionomer cement, liquid of glass ionomer: the x-ray patterns showed in figure(1, 2, 3).the results showed that both hydroxyapatite and glass ionomer powder have crystalline structure while the liquid of glass ionomer cement has no crystalline structure because it composed of inorganic acids. figure 1. x-ray diffraction pattern of synthetic hydroxyapatite. figure 2. x-ray diffraction pattern of powder of glass ionomer cement. figure 3. x-ray diffraction pattern of liquid of glass ionomer cement. 2-for the powder of set glass ionomer cement material figure (4): the results of this test showed that the final set material of glass ionomer cement has crystal of unreacted zno, may be act as cores for the set material. figure 4. x-ray diffraction pattern of set glass ionomer cement. 3-for the powder of set glass ionomer reinforced by (10%, 15%, 20 %, 25% and 30%) cement materials figure (5 ,6 ,7, 8 ,9): the results of this test showed that the final set material of glass ionomer cement reinforced by different ratios of hydroxyapatite has crystals of unreacted zno and hydroxyapatite may be act as cores for the set material while other products of setting reaction non crystalline in nature also the results showed that most of hydroxyapatite particles shear in the setting reactions giving new products non crystalline in nature. figure 5. x-ray diffraction pattern of set glass ionomer cement reinforced by 10% hydroxyapatite. figure 6. x-ray diffraction pattern of set glass ionomer cement reinforced by 15% hydroxyapatite. j bagh college dentistry vol. 25(3), september 2013 x-ray diffraction restorative dentistry 65 figure 7. x-ray diffraction pattern of set glass ionomer cement reinforced by 20% hydroxyapatite. figure 8. x-ray diffraction pattern of set glass ionomer cement reinforced by 25% hydroxyapatite. figure 9. x-ray diffraction pattern of set glass ionomer cement reinforced by 30% hydroxyapatite. b-histopathological test: the histopathological pictures were qualitatively examined under light microscope regarding the intensity of the inflammatory response of the rabbit’s submucosal tissues to the implanted controls and experimental groups and the degree of the subsequent tissue healing at different time periods. 1-for the glass ionomer cement: at three days:sever inflammatory response extend to the lateral side of the tube with necrosis near the implanted material figure(10). figure 10. polyethylene tube filled glass ionomer cement after 3 days hematoxylin and eosin.x 20. at ten days: there is large mass of granulation tissue figure (11). figure 11. polyethylene tube filled glass ionomer cement after 10 days hematoxylin and eosin.x 20. at three weeks: there was connective tissue, hyalinization, fibrous tissue appeared in large area as hallow around the end of the implanted tube. there was coagulation degeneration adjacent to the base material figure (12). figure 12. polyethylene tube filled glass ionomer cement after 3 weeks hematoxylin and eosin.x 20. 2-for the glass ionomer cement reinforced by 10% hydroxyapatite: at three days: sever inflammatory response extend to the lateral side of the tube with necrosis near the implanted material figure (13). j bagh college dentistry vol. 25(3), september 2013 x-ray diffraction restorative dentistry 66 figure13. polyethylene tube filled glass ionomer cement reinforced by 10% hydroxyapatite after 3 days hematoxylin and eosin.x 20. at ten days: there is large mass of granulation tissue figure (14). figure 14. polyethylene tube filled glass ionomer cement reinforced by 10% hydroxyapatite after 10 days hematoxylin and eosin.x 20 at three weeks: there was connective tissue, hyalinization, fibrous tissue appeared in large area as hallow around the end of the implanted tube. there was coagulation degeneration adjacent to the base material figure (15). figure 15. polyethylene tube filled glass ionomer cement reinforced by 10% hydroxyapatite after 3 weeks hematoxylin and eosin.x 20. 3-for the glass ionomer cement reinforced by 20% hydroxyapatite: at three days: a cute inflammatory cells mainly neutrophiles and there was fibrous tissue figure(16). figure 16. polyethylene tube filled glass ionomer cement reinforced by 20% hydroxyapatite after 3 days hematoxylin and eosin.x 20. at ten days: thick dense fibrous tissue with mature fibroblast cells figure (17). figure 17. polyethylene tube filled glass ionomer cement reinforced by 20% hydroxyapatite after 10 days hematoxylin and eosin.x 20. at three weeks: a small mass of loose fibrous tissue with large active fibroblast cells (no inflammation) figure (18). figure18. polyethylene tube filled glass ionomer cement reinforced by 20% hydroxyapatite after 3 weeks hematoxylin and eosin.x 20. 4-for the glass ionomer cement reinforced by 30% hydroxyapatite: at three days: a cute inflammatory cells mainly neutrophiles and there was fibrous tissue j bagh college dentistry vol. 25(3), september 2013 x-ray diffraction restorative dentistry 67 figure(19). figure 19. polyethylene tube filled glass ionomer cement reinforced by 30% hydroxyapatite after 3 days hematoxylin and eosin.x 20. at ten days: thick dense fibrous tissue with mature fibroblast cells figure (20). figure 20. polyethylene tube filled glass ionomer cement reinforced by 30% hydroxyapatite after 10 days hematoxylin and eosin.x 20. at three weeks: thin loose fibrous tissue without inflammation figure (21). figure 21. polyethylene tube filled glass ionomer cement reinforced by 30% hydroxyapatite after 3 weeks hematoxylin and eosin.x 20. discassion hydroxyaptite (ha) is the main biomineral component of human hard tissues (tooth and bone) and it's chemistry is represented by the formula ( ca10(po4)6oh) . 9,10it is biocompatible material when synthesized artificially as biomaterial and if fluoride ions substitute hydroxyl ions on the hexagonal unit cell they give rise to fluorapatite ( ca10(po4)6f2). 11 associated with the biometric process, crystal growth can be used for dentistry applications on the enamel. crystal growth conventionally involves the application of a sulphated acid solution to the enamel .12 x-ray diffraction instruments are used to measure crystal structure, grain size, texture and/or residual stress of materials and compounds through interaction of x-ray beam with a sample. before introducing a new material to the market, its properties and biocompatibility must be previously studied. from a biological point of view, its irritant potential must be evaluated because eventual toxic components may cause irritation, degeneration or even necrosis of the tissues adjacent to the material. 13 this restorative cement is produced via an acid-base reaction between the glass (ca-falsi) and an organic polymer acid (e.g., polyacrylic acid), which results in very interesting physical and chemical properties, such as biocompatibility, high adhesiveness compared to other restorative materials, and cariostatic properties owing to the sustained release of fluorides. 14, 15 according to the methodology used in this study, implantation of standard polyethylene tubes containing the material for analysis, which only comes into contact with the subcutaneous connective tissue through the tubular opening on one side, as the other side is sealed, allows a comparative analysis among the experimental groups in a standardized manner, without interferences determined by variables of volume and areas of juxtaposition. in turn, the external walls of the polyethylene tube serve as control due to their low irritating potential, as a basic parameter of the ideal model of reactionary development. thus, a comparative analysis of the experimental groups could be safely done between the test groups and between them and the control 16, 17-19 in order to increase bonding to bone, hydroxyapatite reinforced glass ionomer cements (ha-gic) have been developed. 20 a number of researchers have attempted to evaluate the effect of the addition of ha powders to restorative dental materials.17 in this study, the powder of glass ionomer cement reinforced by different ratios of hydroxyapatite (ha) has excellent biological behavior, and this is agree with other studies.20, 21 the results of histopathological test shows that increase the percentage of hydroxyapatite may improve the biocompatibility of glass ionomer cement especially after three weeks which may related to that hydroxyapatite (ha) has excellent biological behavior, and its composition and crystal structure are similar to j bagh college dentistry vol. 25(3), september 2013 x-ray diffraction restorative dentistry 68 the apatite in the human dental structure and skeletal system. 21 in spite of the positive results found for the experimental gic in this study, it is worth emphasizing that further research is needed before this material can be indicated for clinical use. references 1. walis a, murry j, mocabe jf. the use of glass polyalkenoate (ionomer) cements in the deciduous dentition. br dent j 1988; 165: 12-13. 2. welbury r,walts a murray j , mocabe j .the 5-year results of a clinical trial comparing a glass ionomer cement restorative with an amalgam restoration. br dent j 1991; 170: 177-81. 3. smith d. composition and characteristics of glass ionomer cements. j am dent assoc 1990; 120: 20-2. 4. hatton p, brook i .characteristic of ultrastructure of glass ionomer (poly-alkenoate) cement. br dent j 1992; 173: 275-7. 5. loescher ar, robinson pp, brook im. the effect of implanted inomeric and acrylic bone cements on peripheral nerve function. j mater sci mater med 1994; 5: 108–12. 6. brook im, hatton pv. glass-ionomers: bioactive implant materials. biomaterials 1998; 19: 565–71. 7. devlin aj, hatton pv, brook im. dependence of in vitro biocompatibilityof ionomeric cements on ion release. j mater sci mater med 1998; 9: 737–41. 8. jonck lm, grobbelaar cj. a glass ionomer for reconstructive surgery ionogran—an ionomeric micro implants. a biological evaluation. clin mater 1992; 9: 85–103. 9. jones f. teeth and bones: applications of surface science to dental materials and related biomaterials. surface science reports.2001; 42(3):75-205. 10. santos m, oliveir m, souza l, mansur h, vasconcelos w. synthesis control and characterization of hyroxyapatite prepared by wet precipitation process. mater res 2004; 7(4): 625-30. 11. aoba t, shimazu y,taya y, soeno y, sato k, miake y. fluoride and apatite formation in vivo and in vitro. j electron microscope 2003; 52(6): 615-25. 12. watts d. orthodontic adhesive resins and composites: principles of adhesive in orthodontic materials science and clinical aspects. new york: thieme stuttgart; 2001. 13. shahi s, rahimi s, lotfi m, yavari hr, gaderian ar. a comparative study of the biocompatibility of three root-end filling materials in rat connective tissue. j endod 2006; 32: 776-80. 14. mickenautsch s, tyas mj, yengopal v, oliveira lb, bonecker m. absence of carious lesions at margins of glass-ionomer cement (gic) and resin-modified gic restorations: a systematic review. eur j prosthodont restor dent 2010; 18:139-45. 15. mickenautsch s, yengopal v, banerjee a. pulp response to resin-modified glass ionomer and calcium hydroxide cements in deep cavities: a quantitative systematic review. dent mater 2010; 26: 761-70. 16. silva ra, assed s, nelson-filho p, silva la, consolaro a. subcutaneous tissue response of isogenic mice to calcium hydroxide-based pastes with chlorhexidine. braz dent j 2009; 20: 99-106. 17. zmener o. tissue response to a new methacrylatebased root canal sealer: preliminary observations in the subcutaneous connective tissue of rats. j endod 2004; 30: 348-51. 18. costa ca, oliveira mf, giro ema, hebling j. biocompatibilityresin-based materials used as pulpcapping agents. int endod j 2003; 36: 831-9. 19. wang xy, baba a, taniguchi k, hagio m, miyazaki k. study on rat subcutaneous reaction to experimental polyurethane elastomers. dent mater j 2004; 23: 5126. 20. yap au, pek ys, kumar ra, cheang p, khor ka. experimental studies on a new bioactive material: haionomer cements. biomaterials 2002; 23: 955–62. 21. moshaverinia a, ansari s, moshaverinia m, roohpour n, darr ja, rehman i. effects of incorporation of hydroxyapatite and fluoroapatite nanobioceramics into conventional glass ionomer cements (gic). acta biomater 2008; 4: 432-40. 28. shahba'a f.doc j bagh college dentistry vol. 25(1), march 2013 concentrations of orthodontics, pedodontics and preventive dentistry171 concentrations of selected elements in saliva among a group of adolescent girls in relation to severity of caries and selected salivary parameters shahba, a m. al-jorrani, b.d.s. (1) sulafa k. elsamarrai, b.d.s., m.sc., ph.d. (2) ali y. majid, b.m.s., m.sc., phd. (3) abstract background: saliva is one of the most important etiological host factors in relation to dental caries. it affects the carious process by its organic and inorganic constituents; in addition to its physiological functions as (flow rate, ph and buffer capacity). the aims of this study were to determine the concentrations of major elements (calcium and phosphorus) and trace elements (ferrous iron, nickel, chromium and aluminum) in saliva among a group of adolescent girls, and to explore the relation of these elements, flow rate and ph with dental caries. material & methods: the study group consisted of 25 girls with an age of 13-15 years old. dental caries was diagnosed by both clinical and radiographical examinations following the criteria of d1-4mfs index. stimulated saliva was collected from patients between 9-11 am under standarized conditions, and chemically analyzed to determine the concentration of calcium, nickel, chromium and aluminum by atomic absorption spectrophotometer, while salivary phosphorus and ferrous iron were determined by using colorimetric method. the average salivary flow rate was measured from total volume, and salivary ph was determined using digital ph meter. all data were analyzed using spss version 19. results: all elements measured in saliva in addition to p/ca ratio recorded statistically non significant correlation with dmfs, except ferrous fe ions which showed statistically significant correlation (r= 0.34, p=0.05). salivary flow rate and ph correlated weakly and statistically not significant with dmfs there were weak and statistically not significant correlations between all elements measured in saliva and salivary flow rate and ph. conclusions: it had been found that fe, ni, al and cr ions present in very small amounts in saliva in comparison to ca and p ions. the presence of these elements in saliva may indicate their presence in food, water and air. key words: trace elements, salivary ph and flow rate, caries severity. (j bagh coll dentistry 2013; 25(1):171-175). introduction saliva is one of the most important host factors that play a role in the caries process through its organic and inorganic constituents, besides the physiological functions. the continuous flow of saliva through the mouth bathes the dentition with remineralizing ions and removes cariogenic challenges (1-3). therefore saliva plays an important role in the equilibrium between the demineralization and the remineralization of enamel (4). trace elements in saliva in correlation to dental caries were investigated by different observational studies including iraqi ones and a great controversy was observed (5-8). in order to increase the knowledge about the role of inorganic elements in relation to dental caries severity, this study was designed. (1) m.sc. student. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad (2) professor. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad (3) materials and methods the total number of patients was 25 girls with an age rang of 13-15 years, recorded according to the last birthday (9). examinations were carried out in the specialized dental center in al-sader city and the specialized center for prosthodontic and orthodontic treatment in al-qaira in baghdad province under standarized conditions (9). dental caries was diagnosed by both clinical and radiographical examinations. the clinical examination of teeth surfaces was done by using dental mirror and sharp dental explorer. assessment and recording of caries experience was done by the application of (d1-4 mfs index for permanent teeth) (10). prior to clinical examination, stimulated saliva was collected from patients between 9-11 am. each patient was asked not to eat or drink (except water) 1 hour before collection, saliva, if possible, should be collected at the same time of day from the same subject, the patient should not smoke or undergo heavy physical stress before collection, a pre-sampling period (1min) is recommended with a fixed collection time, the patient should sit in relaxed position, acute illnesses or chronic diseases as well as medication should be considered, samples containing blood should be j bagh college dentistry vol. 25(1), march 2013 concentrations of orthodontics, pedodontics and preventive dentistry172 discarded if chemical analysis of saliva is planned (11). each patient was asked to chew apiece of arabic gum (0.350.4 gm) for one minute then to remove all saliva by expectoration. chewing was continued for five minutes, with the same piece of gum and saliva collected in sterile screw capped bottle. after collection and disappearance of salivary foam, the ph of saliva was measured using a digital ph meter. salivary volume was estimated and the rate of secretion was expressed as milliliter per minute (ml/ min). each salivary sample was then centrifuged by centrifugater at 3000 r.p.m. (revolution per minute) for 10 minutes. salivary supernatant was stored at (20ºc) in polyethylene tubes for subsequent chemical analysis. chemical analysis was carried out at poisoning consultation center, medical city. calcium, aluminum, nickel and chromium ions were determined using air-acetylene atomic absorption spectrophotometer (aas), while phosphorus and iron were determined color metrically by using chemical kits. spss version 19 (statistical package for social sciences) was used for statistical analysis. descriptive measurement (mean and standard deviation) were used to describe variables. the statistical significance, directions and strength of linear correlation between the concentration of element in each sample and values of d1-4mfs index was measured by person's correlation coefficient. multiple linear regressions between dependant variable (dental caries) and independent variable (concentration of elements) were applied. p value equal to or less than (0.05) level of significance was considered to be statistically significant. the confidence limit was accepted at 95%. results clinical and radiographical examinations showed that all subjects were affected by dental caries. decayed, missed and filled teeth surfaces of girls by fractions of d1-4mfs index were represented by their means and standard deviation (sd) in table 1. the decayed surfaces (ds) contributed the major parts of this index followed by filled surfaces (fs) then missed surfaces because of caries (ms). grade (2) of lesion severity was the highest one, while the frank cavitation; grade (4) was the lowest one. the rang of flow rate was recorded to be 0.6 to 1.8 ml/ min with (1.07 ml/min ± 0.35) mean, while the range of salivary ph was recorded to be 5.3 to 7.5 with (6.54 ± 0.6) mean. table 2 illustrates the concentration of elements in saliva. phosphorus ions were the highest followed by ca ions then ferrous fe, al, ni and finally cr ions. table 3 illustrates the correlation coefficient between elements in saliva with salivary flow rates and ph. it had been found that all elements measured in saliva and p/ca ratio correlated weakly with salivary flow rate and ph, where all of these correlations were statistically not significant. table 4 illustrates the correlation coefficient between salivary (elements and parameters) and caries-experience. a negative strong and statistically highly significant correlation was recorded between p ions and d1; on the other hand a positive weak and statistically significant correlation was recorded between ferrous fe ions and dmfs. while other elements measured in saliva in addition to p/ca ratio showed weak and statistically not significant correlations with caries-experience where some of them were positive while others were negative. regarding the correlations recorded by salivary parameters with caries-experience. it had been found that salivary flow rate and ph recorded negative but statistically not significant correlations with ds and dmfs. while a negative and statistically significant correlation was recorded between salivary flow rate and d3. other correlations recorded by these two parameters and caries experience were weak and statistically not significant. the results of mlr for the dmfs (dependant variable) explained by elements measured in saliva (independent variable) were illustrated in table 5. a complete correlation coefficient of 0.516 was recorded between dmfs and all factors entered. the r2 value of 0.266 was recorded indicated that 26.6% of changes occurred in dmfs were explained by the inorganic composition of saliva. the highest beta coefficients was recorded for p ions, while the lowest one was recorded for p/ca ratio. betacoefficients of all elements measured in saliva were recorded to be statistically not significant. table 6 illustrates the results of mlr for dmfs (dependent variable), explained by salivary flow rate and ph (independent variable). a complete correlation coefficient of 0.323 was recorded between dmfs and (salivary flow rate and ph). r2 value of 0.104 was recorded indicated that 10.4 % of changes occurred in dmfs were explained by salivary flow rate and ph. beta coefficient recorded for salivary ph was higher than that recorded for salivary flow rate; however these two coefficients were statistically not significant. j bagh college dentistry vol. 25(1), march 2013 concentrations of orthodontics, pedodontics and preventive dentistry173 discussion the study group in this research involved 25 girls with an age range 13-15 years old. boys were not involved in this study due to the variation in size of salivary glands that results in variation in composition and flow rate of saliva in addition to variation in adolescent time, hormonal variation and differences in life style (12). stimulated saliva was collected rather than unstimulated saliva, in order to allow comparison with other iraqi studies that were mostly performed on stimulated saliva. in addition to that stimulated saliva is easier and more standardized to collect. in this study calcium and inorganic phosphate were determine in saliva. results showed that p ions concentration (84.62ppm) were higher than ca ions (80.60ppm). this result could be explained by depending on stimulated saliva in this study. in the stimulated saliva there will be an increase in the concentration of inorganic phosphate in comparison to calcium and the level of this elements is timedependent, as it increase with the increase in the duration of stimulation, while ca decrease when going from unstimulated to stimulated saliva (2, 3, 13). in addition to that there is an increase in the proportion of parotid saliva in stimulated saliva that characterized by reduction in ca ions and increase in p ions (14, 15). therefore p/ca ratio in saliva could determine the differences between these two ions according to the duration of stimulation. the concentration of ca and p ions recorded here were higher than that recorded by other iraqi studies (7, 16-18). the variation in the sampling procedure a well as techniques of analysis in addition to difference in ages of the study groups may explain the variation in these iraqi studies and others. other elements namely ferrous iron, nickel, aluminum and chromium were detected to be percent in saliva with the concentrations as seen in table 2. these elements present in our environment; as they present in foods as (meats, potatoes, cheeses, whole-grain breads and cereals, fresh fruits and vegetables, chicken, eggs, milk, nuts, dried beans and peas). these elements could also be found in water that used for drinking or cooking foods and in air as pollutant as for cr vi that presents in air due to erosion of chromium containing rocks and nickel that presents in cigarettes that may inhale by those group as passive smokers (19, 20), so they enters the blood stream via digestive system, lungs or even by coming in contact with skin. the presence of these elements in the blood serum, allowed them to be introduced in whole saliva via gingival crevicular fluid or by incorporating the pure saliva by reaching salivary glands through serum or by both (21, 22). this could explain the presence of these elements in saliva. regarding the relations with dental caries, ca and p ions in this study correlated negatively with dmfs. although they were not significant, these correlations could indicate the important role of saliva in the protection of tooth surface against caries development by maintaining supersaturation of ca and p ions in saliva. other elements studied in saliva except fe showed negative correlations with caries-experience that was statistically not significant. these elements showed the same correlations with d1 and d4. these results indicating that when these elements increased in saliva caries severity decreased, so they may act as cariostatic elements in saliva. these results were confusing, since saliva is the main source of these elements in the outer enamel surface, and these elements were recorded by other studies to act as cariogenic elements (23, 24). it had been found that the concentration of these elements in saliva changed continuously since it depend on their presence in systemic environment that affected by type of food, water, air and even drugs as for iron supplements (25). while caries process is longitudinal process and depend on interaction of a large number of factors with time (26). salivary flow rate and ph considered to be an indicator of caries susceptibility, as the reduction in salivary flow rate can eventually results in reduction of its protective constituents and functions including salivary buffer system, this may increase susceptibility for dental caries (14, 15). there is an inverse association between cariesexperience and these two variables; such negative correlation was also recorded in the present study. the impact of elements measured in saliva on dental caries seems to be much more in comparison to that of salivary parameters (flow rate and ph). as results recorded a value of r2 equal to 0.266 for elements in saliva compared to only 0.104 for salivary parameters indicating that 26.6% of changes occurred in caries-experience were explained by inorganic composition of saliva, while salivary flow rate and ph explain only 10.4% of these changes. this could explain the important role of inorganic composition of saliva in the initiation of dental caries by incorporation of its inorganic elements in outer enamel surface during the demineralization and remineralization processes. j bagh college dentistry vol. 25(1), march 2013 concentrations of orthodontics, pedodontics and preventive dentistry174 references 1. edgar m, dawes c, o'mullane d. saliva and oral health. 3rd ed. british dental association, 2005. 2. guy c. role of saliva in the oral processing. in: jianshe ch, lina e (ed). food oral processing. oxford: garsington road; 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18(4): 157-62. 24. amr m. trace elements in egyptian teeth. international journal of the physical sciences 2011; 6(27). 25. queimado l, obeso d, hatfield m. dysfunction of wnt pathway component in human salivary gland tumors. arch otolaryngolo head neck surg 2008; 134 (1): 94-101. 26. zhang x, dai j, han yx, shao jl. prevalence profile of oral disease in ancient population. the open anthropology j 2010; 3: 12-15. table 1: caries – experience of permanent teeth (d1-4mfs) among patients. fractions mean ± sd ds 4.44 ± 2.48 ms 1.60 ± 2.78 fs 2.60 ± 2.60 dmfs 8.64 ± 4.06 d1 0.84 ± 0.68 d2 1.76 ± 0.87 d3 1.20 ± 0.95 d4 0.64 ± 1.11 table 2: concentration of elements in saliva (means ± sd) elements mean ± sd (ppm) ca 80.60 ± 22.97 p 84.62 ± 01.72 p / ca 1.18 ± 00.51 fe 0.69 ± 00.28 ni 0.07 ± 00.01 al 0.24 ± 00.10 cr 0.06 ± 00.02 j bagh college dentistry vol. 25(1), march 2013 concentrations of orthodontics, pedodontics and preventive dentistry175 table 3: correlation coefficient between elements measured in saliva and salivary (flow rate and ph). elements ph flow rate ca r 0.00 r 0.21 p 1.00 p 0.29 p r 0.07 r 0.28 p 0.16 p 0.16 p/ca r 0.06 r -0.18 p 0.74 p 0.36 fe r 0.21 r -0.31 p 0.30 p 0.12 al r 0.17 r 0.07 p 0.41 p 0.71 ni r 0.11 r 0.02 p 0.58 p 0.91 cr r 0.16 r 0.00 p 0.41 p 0.97 table 4: correlation coefficients between salivary (elements and parameters) and caries experience elements d1 d2 d3 d4 ds fs dmfs r p r p r p r p r p r p r p ca 0.03 0.88 0.25 0.22 0.20 0.32 0.06 0.74 0.14 0.48 0.16 0.42 0.04 0.82 p 0.55** 0.004 0.12 0.56 0.19 0.36 0.09 0.65 0.14 0.50 0.10 0.62 0.14 0.48 p/ca 0.20 0.32 0.18 0.38 0.28 0.17 0.08 0.67 0.20 0.31 0.16 0.43 0.11 0.58 fe 0.26 0.20 0.01 0.61 0.11 0.57 0.00 0.98 0.08 0.69 0.11 0.57 0.34* 0.05 al 0.05 0.81 0.09 0.66 0.11 0.58 0.04 0.84 0.02 0.92 0.27 0.17 0.09 0.63 ni 0.35 0.08 0.00 0.97 0.00 0.98 0.05 0.80 0.12 0.56 0.22 0.27 0.03 0.87 cr 0.19 0.35 0.12 0.55 0.35 0.08 0.12 0.54 0.28 0.16 0.01 0.96 0.28 0.16 salivary parameters f.r 0.28 0.16 0.00 0.97 0.40* 0.04 0.18 0.36 0.33 0.09 0.28 0.16 0.26 0.19 ph 0.19 0.36 0.05 0.77 0.32 0.10 0.21 0.30 0.21 0.29 0.02 0.89 0.22 0.29 table 5: multiple linear regressions (mlr) between elements measured in saliva and dmfs elements b (slope) std. error beta t pvalue ca 0.111 0.119 0.627 0.930 0.365 p 0.048 0.099 0.139 0.485 0.634 p/ca 5.771 5.867 0.727 0.984 0.339 fe 4.764 3.107 0.333 1.533 0.144 al 3.412 3.094 0.252 1.103 0.285 ni 0.313 0.856 0.083 0.366 0.719 cr 7.553 43.674 0.318 1.318 0.205 r= 0.323, r2= 0.104 table 6: multiple linear regressions (mlr) between salivary (flow rate and ph) and dmfs salivary variables b (slop) std. error beta t sig. flow rate 2.695 2.302 0.239 -1.171 0.254 ph 1.235 1.357 0.186 0.910 0.373 r= 0.516 r2= 0.266 linz.doc j bagh college dentistry vol. 27(1), march 2015 antibacterial effect of restorative dentistry 48 antibacterial effects of mineral trioxide aggregate and biodentine tm after the addition of different concentrations of black seed aqueous solutions linz a. shalan, b.d.s., m.sc. (1) majida k. al-hashimi, b.d.s., m.s. (2) abstract background: mineral trioxide aggregate (mta) and biodentinetm cements are new materials with numerous exciting clinical applications. both have appreciable properties which include good physical properties and the ability to stimulate tissue regeneration as well as good antibacterial effects. the aim of this study was to investigate and compare the antibacterial effects of mta and biodentinetm, when they were mixed with different concentrations of aqueous solutions of black seed extract, against enterococcus faecalis. materials and methods: mta and biodentinetmwere prepared according to the manufacturer’s instructions. the method of mawlood was followed to prepare the black seed aqueous solution. agar diffusion method on brain heart infusion agar was employed.twenty, 9 cm diameter, petri-plates with 25 ml of muller hinton agar media were prepared. a sterile spreader was used to inoculate the microorganisms. with a micropipette 0.1 ml of the enterococcus faecalis suspension was added to the surface of the plates. within 15 minutes, after inoculation of the plates, 4 cavities, each one measuring 5 mm in diameter and 4 mm in depth, were made in each agar plate. a total of 20 agar plates were divided into 2 groups consisted of 10 plates each; group a: each plate contained 4 wells filled with mta alone and mta mixed with 10%, 30% and 50% of black seed aqueous solutions respectively.group b: each plate contained 4 wells filled with biodentinetmalone and biodentinetmmixed with 10%, 30% and 50% of black seed aqueous solutionsrespectively. next day after incubation, the agar plates were examined for bacterial inhibition zones. with a scientific ruler the diameter of the antibacterial inhibition zones were measured. the data were recorded and statistically analyzed, by the anova and the student's t-test. results: both cements had antibacterial effects, which were increased with the addition of the aqueous solutions of black seed extract. the increase in the diameter of enterococcus faecalis inhibition zones was directly proportional with the increase in the concentration of the added black seed aqueous extract. conclusion: adding aqueous solutions of black seed extract to both mta and biodentine™ increased their potential to inhibit the growth of enterococcus faecalis. key words: mineral trioxide aggregate, biodentine tm, black seed. (j bagh coll dentistry 2015; 27(1):48-53). introduction it is well known that the microorganisms have the most important role in endodontic treatment failures.(1,2) the prognosis of any treatment will depend on the successful elimination of the microorganisms and infected tissues as well as effective sealing of the root-end to prevent future recontamination.(3,4) studies have shown that certain microorganisms are recovered fromthe infected teeth. these are chiefly enterococcus, actinomyces, propionibacterium, yeasts, candida albicans, streptococcus and other types.(5) however, advances in techniques and materials have increased the success rate of the conventional root canal treatment or retreatmentcases.(3) mineral trioxide aggregate (mta) is a mechanical mixture of 3 powder ingredients; it contains fine hydrophilic particles of 75% portland cement clinker, 20% bismuth oxide and 5% gypsum by weight,italso contains trace amounts of sio2, cao, mgo, k2so4, and na2so4.mta is a powder that, in the presence of moisture, forms a colloidal gel that solidifies, after approximately 4 hours, to form a hard cement. (6) (1) lecturer, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor. department of conservative dentistry, college of dentistry, university of baghdad. it was used to seal off the pathways of communication between the root canal system and the external surface of the tooth.(7-10). moreover, it was concluded that the mechanism of action of mta, may encourage hard tissue deposition (11). biodentinetm was reported as a safe and useful material, sinceit possesses specific properties, including the promotion of significant intratubular calcium diffusion,(12,13) biocompatibility,(14,15) and expansion to reduce the dentin/-material interface to a minimum, allowingstable micromechanical intratubular attachment.(12,14) biodentine tm is presented in a capsule contain-ing the predetermined ratio of powder and liquid. the powder consists of tricalcium silicate (3cao.sio2), calcium carbonate (caco3), and zirconium dioxide (zro2); the liquid consists of calcium chloride (cacl2.2h2o), water reducing agent, and water. (14,15) nigella sativa (ns) commonly known as the black seed (bs); this mild annual aromatic herb is indigenous to the middle east and southeast asia where it has been used as a traditional remedy for over 2000 years. it was used so extensively that it became known as the seed of j bagh college dentistry vol. 27(1), march 2015 antibacterial effect of restorative dentistry 49 blessing. (16) it was reported that, a marked decrease in the number of intracanal microbes occurred when different concentrations of ns extract were used.(17) most of the ns pharmacological actions are due to its antioxidant activity which is mainly due to its ability to scavenge free radicals and/or inhibit lipid peroxidation. the seeds of ns contain a yellowish volatile oil (0.5-1.6%), a fixed oil (35.6-41.6%), proteins (22.7%), amino acids, minerals and vitamins.(17) the purpose of this,in vitro,study was to investigate and compare the antibacterial effects of mta and biodentinetm,when they were mixed with different concentrations of aqueous solutions of black seed extract, against enterococcus faecalis (e. faecalis). materials and methods the tested materials, mta (dentsply, tulsa dental, ok, usa) and biodentine tm (zizine, france), were prepared strictly according to the manufacturer’s instructions. the antimicrobial activity of the endodontic cements, mixed with three different concentrations of the aqueous solutions of bswas evaluated bythe agar diffusion method. e. faecalis microorganisms were identified in the central health laboratories, ministryof health in baghdad by a combination of colonial pigmentation, colonialmorphology, haemolysis on bhiba, cell morphology (microscopicmorphology) and biochemical tests. grouping beta haemolytic streptococci test was done on these colonies by using pastorex strep test (bio-rad/japan). the method of mawlood (1996) was followed to prepare the bsaqueous solution. ns seeds (100g) were grinded and dissolved in distilled water bath for boiling, and then filtrated. the filtrated suspension was placed in an incubator at 37ºc, for drying. to obtain the first concentration (100 mg/ml), one gram of the collected dried powder was re-dissolved in 5 ml of distilled water and the volume was completed to 10 ml, from this concentration the concentrations of 50%, 30%, and 10% were prepared by the dilution technique. agar diffusion method on brain heart infusion agar was employed. twenty, 9 cm diameter, petri-plates with 25 ml of muller hinton agar media were prepared.a sterile spreader was used to inoculate the microorganismsfrom the prepared normal saline tubes inoculated with microorganismswhich had been fit to 0.5 mcfarland standards. with an adjustablemicropipette, 0.1 ml of the bacterial suspension was added to the surface ofthe plates which were inoculated by spreading the suspension in threedirections, and a final spreading was done over the outer rim of the plate.the plates were allowed to dry for 3-5 minutes. within 15minutes, after inoculation of the plates, 4 cavities each one measuring 5 mm in diameter and 4 mm in depth were made in each agar plate using corkpoorer.the arrangements of the wells werenot close tothe outer edges of the plates and far enough apart to prevent overlapping of the zones of the microbial inhibitions. a total of 20 agar plates were used in this study; the samples were divided into 2 groups consisted of 10 plates each; group a: each plate contained 4 wells filled with mtaalone and mta mixed with different concentrations of bs aqueous solutions (10%, 30% and 50% respectively). group b: each plate contained 4 wells filled with biodentine tm alone and biodentine tm mixed with different concentrations of bs aqueous solutions (10%, 30% and 50% respectively). the plates were pre-incubated in the culture media at the environmental temperature,for two hours before incubation, to allow dissociation and diffusion of thetested materials. thenthe plates were incubated at 37ºc for 24 hours.next day, the agar plates were examined for bacterial inhibition zones.witha scientific ruler the diameter of theantibacterial inhibition zones were measured by passing the scientific ruler through the center of the wells. data were statistically analyzed, by the anova and the student's ttest, to compare the differences of the antie.faecalis effects of mta and biodentine tm cements when mixed with different concentrations of bs aqueous solutions. results regarding the antimicrobial activity of mta, which was mixed with different concentrations of aqueous solutions of bs extract, the summary of the recorded results are presented as means, standard deviations (sd), minimum and maximum values of e. faecalis inhibition zones (in mm); these results are shown in table 1, figure 1. table 1.descriptive statistics of mta, in mm. testes groups min. max. mean sd mta 2.62 2.77 2.72 + 0.105 mta+10% bs 2.72 2.87 2.82 + 0.104 mta+30% bs 2.92 3.07 2.98 + 0.100 mta+50% bs 3.32 3.57 3.48 + 0.103 j bagh college dentistry vol. 27(1), march 2015 antibacterial effect of restorative dentistry 50 figure 1: a sample mta groups. as seen in table 1, mta has antibacterial effect which was increased with the addition of the aqueous solutions of bs extract. the increase in the mta antibacterial effect, against e. faecalis, was directly proportional with the increase in the concentration of the added bs extract. the anova test results of the mta groups showed a highly significant difference (p <0.000) (table 2). to compare the paired groups, student's t-test was performed, (table 3). table 2. the anova test of mta groups s.o.v ss df ms f sig. between groups 6.00 7 0.857 77.143 0.000 hs within groups 0.80 72 0.11 total 6.80 79 table 3. student's t-test of the mta groups compared groups m. m. diff. p sig. mta vs. mta+10% bs 2.72 0.10 0.000 hs 2.82 mta vs. mta+30% bs 2.72 0.16 0.000 hs 2.98 mta vs. mta+50% bs 2.72 0.76 0.000 hs 3.48 mta+10% bs vs. mta+30% bs 2.82 0.16 0.000 hs 2.98 mta+10% bs vs. mta+50% bs 2.82 0.66 0.000 hs 3.48 mta+30% bs vs. mta+50% bs 2.98 0.50 0.000 hs 3.48 the statistical analysis results, concerning the e. faecalis inhibition zones, revealed highly significant differences between all the compared groups (p<0.000). it is clear that mta had produced clear antibacterial inhibition zones. the collected data demonstrated highly statistically significant increases in the inhibition zones with the increase in the concentration of the added aqueous solutions of bs extract (p<0.000). on the other hand, the effect of biodentine tm, which was mixed with different concentrations of aqueous solutions of bs extract, the summary of the descriptive statistics (means, standard deviations (sd), mini-mum and maximum values of e. faecalis inhibition zones, in mm, are presented in table 4, figure 2. table 4: descriptive statistics of biodentine tm (in mm) group min. max. m. sd bio 3.90 4.10 4.02 + 0.109 bio+10% bs 4.10 4.30 4.10 + 0.103 bio+30% bs 4.20 4.40 4.32 + 0.107 bio+50% bs 4.40 4.60 4.52 + 0.109 figure 2: a sample of biodentine tm groups. the antimicrobial action of biodentinetm on e. faecalis microorganisms was superior to that of mta. biodentinetm showed a remarkable antibacterial effect, which was increased with the addition of the aqueous solutions of bs extract. also, the increase in the biodentinetm effect, against e. faecalis, was directly proportional with the increase in the concentration of the added bs aqueous extract. the analysis of variance (anova) test results of the biodentinetm group scored a highly significant difference (p<0.000) (table 4), therefore; to compare the paired groups, the student's t-test was done, concerning the inhibition zones of e. faecalis as shown in table 5. table 4: the anova test of biodentine tm groups s.o.v ss df ms f sig. between groups 0.676 3 0.225 18.778 0.000 hs within groups 0.192 16 0.120 total 0.868 19 j bagh college dentistry vol. 27(1), march 2015 antibacterial effect of restorative dentistry 51 table 5: student's t-test of biodentine groups compared groups m. m. diff. p sig. bio vs. bio+10% bs 4.02 0.08 0.000 hs 4.10 bio vs. bio+30% bs 4.00 0.30 0.000 hs 4.32 bio vs. bio+50% bs 4.02 1.50 0.000 hs 4.52 bio+10% bs vs. bio+30% bs 4.10 0.22 0.000 hs 4.32 bio+10% bs vs. bio+50% bs 4.10 0.42 0.000 hs 4.52 bio+30% bs vs. bio+50% bs 4.32 0.20 0.000 hs 4.52 concerning biodentine tm the statistical analysis, regarding the e. faecalis inhibition zones, had showed highly significant differences between all the compared groups (p<0.000). it is clear that biodentinetm has produced bacterial inhibition zones that were increased in diameter with the increase in the concentrations of the added bs aqueous extract. one final interesting statistical analysis was performed to compare both groups of mta and biodentinetm; the recorded results are seen in table 6. table 6: student's t-test results of both mta and biodentinetm. compared groups t-test p sig. mta vs. bio. 55.52 0.000 hs mta+10% bs vs. bio+10% bs 57.56 0.000 hs mta+30% bs vs. bio+30% bs 60.82 0.000 hs mta+50% bs vs. bio+50% bs 71.03 0.000 hs in this study the antimicrobial activity of biodentinetm when used alone was highly statistically better than that of mta alone (p<0.000). the same thing was detected when different concentrations of aqueous solutions of bs extract were added; all the tested biodentinetm groups were highly statistically superior in their antimicrobial activity than their respective groups of mta. discussion certain herbs and plants found to have different antibacterial effects; nigella sativa (the black seed) is one of them. this aromatic, well known herb has been used in middle east, as a traditional remedy, for over 2000 years.(18,19) the results of this investigation showed that, all the tested samples possess antibacterial properties against e. faecalis. the antibacterial effect of mta, when used alone, was clear in the study. this comes in agreement with some studies which reported that mta is an effective material against microorganisms including e. faecalis (20-23). while other studies showed limited antimicrobial activity of mta.(24-26) the conflicting results regarding the antibacterial activity of mta against e. faecalis may be attributed to the available nutrients, level of oxygen tension, incubation period, methods of evaluation, and different laboratory set-ups employed. the antimicrobial effect of mta, against e. faecalis, was increased with the addition of different concentrations of the aqueous solutions of the bs extract. it worth's to mention that the increase in the mta antibacterial effect was directly proportional with the increase in the concentration of the added bs extract. this could be attributed to the presence of thymohydroquinone in the chemical composition of the bs (27); moreover, it could be due to the presence of other materials including nigellone, thymoquinone, thymol, carvacrol, α & β-pinene, d-limonene, d-citronellol, p-cymene and 2-(2 methoxypropyl)-5-methyl-1,4-benzen-ediol in the chemical composition of the bs extract which could be the responsible factors of its antimicrobial effects.(28) in this study, biodentinetm showed an antibacterial activity that is more than mta, since the antibacterial inhibition zones were larger in diameter than that around mta specimens. this material exhibits an efficient and durable protection of the pulp from bacterial invasion as a dentine substitute. biodentinetm is similar to mta in its basic composition; the powder mainly contains tricalcium silicate, calcium carbonate, and dicalcium silicate. the liquid consists of calcium chloride in aqueous solution with an admixture of polycarboxylate (29), therefore; they have comparable antibacterial effects. in this investigation, it was found that, all the tested samples of biodentinetm possessed antibacterial properties. when biodentinetm was used alone, there was an obvious antibacterial effect against e. faecalis. this comes in agreej bagh college dentistry vol. 27(1), march 2015 antibacterial effect of restorative dentistry 52 ment with another study which reported that biodentinetm has an antibacterial activity that is comparable to that of ca-based cement. (29, 30) the antibacterial effect of biodentinetm, in the present study showed that the inhibition zones of e. faecalis, on the experimental agar plates, were increased with the addition of different concentrations of the aqueous solutions of the bs extract. furthermore, the increase in the diameter of e. faecalis inhibition zones was directly proportional with the increase in the concentration of the added bs extract. this finding, as mentioned before, may be due to the chemical composition of the bs extract (28); which statistically increased the anti-e. faecalis properties of biodentine™ even more than that of mta. within the framework of this research, it could be concluded that mta, as well as, biodentine™ are promising materials since they have the potential to inhibit the growth of e. faecalis. moreover, the adding aqueous solutions of bs extract increased their antibacterial activity against e. faecalis. references 1. zarrabi mh, javidi m, naderinasab m and gharechahi m. comparative evaluation of antimicrobial activity of three cements: new endodontic cement (nec), mineral trioxide aggregate (mta) and portland cement. j oral sci 2009; 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(1) ban ali salih, b.d.s., m.sc. (2) abstract background: molar incisor hypomineralisation (mih) is one of the biggest challenges with great clinical interest. currently, the etiology of mih remains unclear. there is no previous study concerning school children aged 7 – 9 years in al-najaf governorate in order to estimate the prevalence and severity of molar incisor hypomineralisation and the possible associated risk factors. this study aimed to estimate the prevalence, severity and the possible associated etiological factors of molar incisor hypomineralisation and also to study the correlation between body mass index and molar incisor hypomineralisation. material and methods: across sectional study conducted at al-najaf governorate. a total of 600 children were enrolled those who did not met the inclusion criteria were excluded. a structured self-administered validated arabic language questionnaire and an examination sheet were used for data collection. body weight and height were measured and the body mass index was calculated. dental material and supplies were used in examination. the demarcated hypomineralization was recorded according to the 10 point scoring system depended on the eapd evaluation criteria the severity was assessed according to the clinical evaluation of the examiner and the presence of opacities. results: the response rate was 84.7% and the highest was in the 9-year-old children, the participants were 532 children, the prevalence of hypomineralisation defect was 22.9%. the prevalence of demarcated hypomineralisation was increased concomitantly with the age, and the 9-year-old children were the more affected. the overall prevalence of mih among boys was lower than girls; (17.3%) and 22.6%, respectively. the severely affected teeth were 33/1464 teeth, represented 2.3%, severely affected molars were 25 (5.1%) and the severely affected incisors were 8 (0.8%). more severely affected teeth were found in obese and overweight children were also increased with the age of child. conclusions: the prevalence of molar incisor hypomineralisation in this study was 22.9%, mih was more prevalent among girls, the 9-year-old, normal body weight and urban residents children. the severely affected teeth represented 4.5% of the total number of teeth, molars were more severely affected than incisors, obese and overweight children and older children have more severe mih. further studies are suggested. key words: molar incisor hypomineralization, prevalence, severity. (j bagh coll dentistry 2015; 27(3):169-173) introduction molar incisor hypominrealization (mih) is a developmentally derived dental defect that involves hypomineralization of one to four permanent first molars frequently associated with similarly affected permanent incisors (1). mih is defined as “hypomineralization of one to four permanent first molars, frequently associated with affected incisors”. generally the defects of the incisors are milder than those of the molars since masticatory forces are absent. (2). in 2003 the term molar incisor hypomineralization (mih) was introduced by weerheijm et al. to describe white or yellow-brown demarcated opacities on first permanent molars, frequently associated with affected permanent incisors (3). nowadays, mih is one of the biggest challenges with great clinical interest for dental practice because mih has a great impact on the oral health as consequently, on the quality of life of children and adolescents (2). (1)master student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. in many countries, researchers have established the prevalence of mih in healthy children. the reported prevalence varies between 2.4% and 40.2% (4). currently, the etiology of mih remains unclear and is thought to be acquired via multifactorial, systemic disturbances during amelogenesis (5). different factors might associated with the development of mih and different studies concerned with this subjects these factors including, prenatal factors such as mother’s diseases , medications and treatments received during pregnancy are sometimes implicated (6), perinatal factors including the gestational age, mode of delivery, birth weight, duration of labor, neonatal comorbidities, admission to neonatal intensive care unit. or postnatal factors such as feeding type, medication and vaccinations during the first 3 years of child life, in addition to socioeconomic factors and nutrition during same period (6,7). moreover, a combination of these variables increased the risk to develop severe demarcated opacities by more five times (8). effect of body mass index on mih was the concern of many j bagh college dentistry vol. 27(3), september 2015 prevalence and severity pedodontics, orthodontics and preventive dentistry170 researchers but much interest was on very low birth weight children that can be susceptible to dental caries due to biological and socioeconomic factors (4). developmental enamel defects are more prevalent in vlbw children who require prolonged oral endotracheal intubation. these defects typically persist at least 10 years into childhood. a significant association was found between caries and enamel (6,8) hypoplasia in the primary dentition of vlbw children (3). clinically, the problems are related to unexpectedly rapid caries development in the erupting first permanent molar and unpredictable behavior of apparently intact opacities and rapid breakdown of tooth structure may occur, giving rise to acute symptoms and complicated treatments (6).the child will experience pain, sensitivity and complain about and suffering from toothache during teeth brushing (9). early diagnosis and immediate treatment for mih should be obtained carefully. (2). the management of mih could include diet counseling for dietary modifications to avoid dental caries dental erosion and dental sensitivity recommended a tooth paste with a fluoride, application of fissure sealants, bleaching with carbamide peroxide, microabrasion with either 18% hydrochloric acid or 37% phosphoric acid and pumice for 60s (6). use of glass ionomer cements and in mild and moderate mih cases composite restorations using self-etching primer adhesive bonding systems is the treatment of choice (9) and may last for many years until indirect restorations would be placed (6). in severecases, transitional treatment for function and aesthetics can be provided until adolescence. cast restorations have also been used (6). any extraction of first permanent molars should only be carried out with consideration of the possible orthodontic implications (10). materials and methods across sectional conducted at al-najaf governorate, data were collected during the period from january to the end of april 2014. study population included the primary school children aged, 7-9 years of both genders of alnajaf governorate. children having amelogenesis imperfecta, tetracycline staining or undergoing orthodontic treatment at the time of study, those with completely broken crowns of the first permanent molars, or those whose parent/guardians refused to filled missed data or not get back the questionnaire were excluded from the study. sample size for was calculated according to the standard equation and a total of 600 children were enrolled. a structured self-administered validated arabic language questionnaire and an examination sheet were performed. body weight and height were measured and the body mass index was calculated according to the standards. dental material and supplies were used in examination. prior to the clinical examination the participating children were given a toothbrush and fluoridated toothpaste to brush their teeth thoroughly under the supervision of the researcher. the demarcated hypomineralization was recorded according to the 10 point scoring system depended on the eapd evaluation criteria the severity was assessed according to the clinical evaluation of the examiner and the presence of opacities. data of the studied group were entered and analyzed by using the statistical package for social sciences (spss) version 21 and appropriate statistical tests were used to assess the differences and correlations between variables. results out of the 532 participants, 395 (74.2%) were not affected, and 137 (25.8%) having at least one permanent index tooth with an enamel developmental defect. out of the 137 children with an enamel developmental defect, 122 children (89.1%) had a demarcated hypomineralisation in at least one of their index teeth; of them, 17 had demarcated hypomineralisation lesion in incisor teeth only giving a prevalence of ih of (3.2%), 58 children (10.9%) had mh and 47 (8.8%) children had both mh and ih. according to these values, the prevalence of hypomineralisation defect in at least one index tooth was 22.9% and according to the definition of mih, 105 children had demarcated hypomineralisation in at least one first molar tooth or first molars and incisors, this giving an overall prevalence of mih of (19.7%), (table 1). as it shown in table 2, boys were 56 represented (45.9%) and girls were 66 represented (54.1%), this indicated, generally, that girls were more affected with demarcated hypomineralisation than boys. the prevalence of demarcated hypomineralisation was increased concomitantly with the age, and the 9-year-old children were the more affected; 50 (41.0%), than children of 7-year-old and 8-year-old. the distribution of affected children according to the body mass index (bmi) categories revealed that 8 children (6.6%) were underweight, 63 (51.6%) had normal bmi, 16 (13.1%) were overweight and 35 (28.7%) were obese. urban resident children were more affected than rural, (13.2%) and (9.8%), respectively. j bagh college dentistry vol. 27(3), september 2015 prevalence and severity pedodontics, orthodontics and preventive dentistry171 the overall prevalence of mih among boys was lower than girls; (17.3%) and 22.6%, respectively and the prevalence of at least one index tooth affected was also lower in boys than girls; 56 (19.4%) and 66 (27.2%), respectively (table 3). regarding the distribution by age; table 4 shows that the prevalence of mih was increased with the age; in those aged 7 years the prevalence was 19.2%, in those aged 8 years it was 19.6% and in those aged 9 years it was 20.3%. similar trend was found regarding the prevalence of at least one index tooth affected; 21.2%, 22.8% and 24.2%, respectively. severity of demarcated hypomineralisation by application of the criteria of scoring of mih of the european academy of paediatric dentistry, the total number of severely affected teeth was 33 teeth (incisor and molars) these teeth were found in 24children where some children had more than one severely affected teeth, the prevalence of severely affected among the 122 children with demarcated hypomineralisation was 19.7% and when calculated from the total 532 children, the prevalence was 4.5%. table 1. prevalence of mih among study population involved teeth no. prevalence (%) ih only 17 3.2% mh only 58 10.9% both ih and mh 47 8.8% at least one first molar tooth or first molars and incisors (mih) 105 19.7% at least one index tooth 122 22.9% table 2. demographic characteristics of 122 children with demarcated hypomineralisation variable no. % from affected (n=122) % from total study sample (n=532) p gender boys 56 45.9 10.5 0.36 ns girls 66 54.1 12.4 age 7-year-old 31 25.4 5.8 0.11 ns 8-year-old 41 33.6 7.7 9-year-old 50 41.0 9.4 bmi (kg/m2) underweight 8 6.6 1.5 < 0.001 s normal 63 51.6 11.8 overweight 16 13.1 3.0 obese 35 28.7 6.6 mean ± sd 18.8 ± 4.4 range 13 29 residence urban 70 57.4 13.2 0.10 ns rural 52 42.6 9.8 ns: non-significant, s: significant. table 3. distribution and prevalence of demarcated hypomineralisation lesions in the permanent index teeth according to gender teeth involvement boys (n= 289) girls (n=243) total p no. prevalence % no. prevalence % no. prevalence % single incisor 3 1.0 8 3.3 11 2.1 0.24 multiple incisor 22 7.6 25 10.3 47 8.8 0.61 ih only 6 2.1 11 4.5 17 3.2 0.75 single molar 5 1.7 9 3.7 14 2.6 0.35 multiple molar 21 7.3 31 12.8 52 9.8 0.60 mh 26 9.0 40 16.5 66 12.4 0.52 mih 50 17.3 55 22.6 105 19.7 0.55 at least one index tooth 56 19.4 66 27.2 122 22.9 0.36 ns: non-significant, s: significant j bagh college dentistry vol. 27(3), september 2015 prevalence and severity pedodontics, orthodontics and preventive dentistry172 table 4: distribution and prevalence of demarcated hypomineralisation lesions in the permanent index teeth according to age teeth involvement prevalence n (%) p 7 years (n= 146) 8 years (n=179) 9 years (n=207) total single incisor 5 (3.4) 1 (0.6) 5 (2.4) 11 (2.1) 0.43ns multiple incisor 11 (7.5) 17 (9.5) 19 (9.2) 47 (8.8) 0.74ns ih only 4 (2.7) 7 (3.9) 6 (2.9) 17 (3.2) 0.45 ns single molar 3 (2.1) 5 (2.8) 6 (2.9) 14 (2.6) 0.25 ns multiple molar 17 (11.6) 13 (7.3) 22 (10.6) 52 (9.8) 0.21 ns mh 20 (13.7) 18 (10.1) 28 (13.5) 66 (12.4) 0.43 ns mih 28 (19.2) 35 (19.6) 42 (20.3) 105 (19.7) 0.10 ns at least one index tooth 31 (21.2) 41 (22.8) 50 (24.2) 122 (22.9) 0.72 ns ns: non-significant, s: significant table 5: distribution and prevalence of demarcated hypomineralisation lesions in the permanent index teeth according to bmi teeth involvement underweight (n=8) normal (n=63) overweight (n=16) obese (n=35) p no. % no. % no. % no. % single incisor 1 0.8 5 4.1 1 0.8 4 3.3 0.37 ns multiple incisor 4 3.3 20 16.4 11 9.0 12 9.8 0.22 ns ih only 1 0.8 6 4.9 4 3.3 6 4.9 0.45 ns single molar 1 0.8 6 4.9 4 3.3 3 2.5 0.18 ns multiple molar 3 2.5 27 22.1 6 4.9 16 13.1 0.39 ns mih 7 5.7 57 46.7 12 9.8 29 23.8 0.40 ns at least one index tooth 8 6.6 63 51.6 16 13.1 35 28.7 0.26 ns ns: non-significant discussion the present study indicates that mih is a widely spread condition amongest iraqi children in al najaf governorate. the reported prevalence of (22.9%), although higher, it is still comparable to that observed in jordan and iran, but is far greater than that reported for libya (11). the present study reported 22.9% hypomineralization in at least one index tooth and 19.7% hypomineralization in at least one first molar tooth or first molars and incisors, this finding agreed and close to that reported by ghanim et al. in al mosul (iraq) who found 21.5% and 18.6%, respectively (7). this slight increase might be due to methodological and technical differences between the two studies or may refer to increase in the problem inside iraqi community. this high percentage of mih appears to be more than the expected ‘true’ prevalence of the defect indicating a variation between countries, depending on the various etiological factors involved. girls in present study were affected more than boys. this finding is consistent with results of salih study in iraq (1). conversely, this finding disagreed that of allazzam study in saudi arabia that showed the predominance of male gender (12). this inconsistency might be due to difference in sample size between the two studies (smaller sample size of saudi study as 267), genetic bases and environmental factors. this study revealed increase demarcated hypomineralization with increase age of children to reach 41% of affected 9 year-old children. ghanim study (7) revealed similar findings among iranian children. mean bmi of the studied children was 18.8 ± 4.4 kg/m², approximately half of them were with normal bmi and one third of them were obese. this finding is similar to results of heatmüller study in germany (13). urban residents among children with demarcated hypomineralization were more than rural which is similar to results of biondi study in argentina (14). according to the criteria of scoring of mih of the european academy of pediatric dentistry recommendations, 27.7% of molars had white creamy opacities without peb and 15.2% of incisors had white creamy opacities without peb on the other hand, 3.5% of molars had white creamy opacities with peb and 0.8% of incisors had white creamy opacities with peb. these results were lower than that reported by allazzam study in saudi arabia (12) that showed the percentage of demarcated opacities as 56.5% and opacities with peb as 8.7%. this may partly be explained by the inclusion of older children in saudi study, as some of the demarcated opacities j bagh college dentistry vol. 27(3), september 2015 prevalence and severity pedodontics, orthodontics and preventive dentistry173 may break down over time. this explanation is supported by findings of wogelius et al. who reported an increased prevalence of posteruptive breakdown by increasing age (15). only 2.3% of involved teeth were severely affected by mih, molars were severely affected than incisors. this finding is consistent with results of lygidakis study in greece (16). posteruptive enamel breakdown is present and frequently occurs as the tooth is emerging, there is a history of dental sensitivity, often widespread caries is associated with the affected enamel, crown destruction can readily advance to involve the dental pulp, defective atypical restoration is present, aesthetic concerns are expressed by the patient or parent. in severe cases transitional treatment for function and aesthetics can be provided, using the various modalities now available until adolescence when permanent prosthetic approach with crowns in molars and veneers in incisors can be initiated (17). as conclusions; the prevalence of mih among school children in iraqi of al najaf governorate was 22.9%. demarcated hypomineralisation was more prevalent among girls. the prevalence increased concomitantly with the age, and the 9year-old children were the more affected. urban residents school children were more affected school children with normal bmi were the predominant among the affected children. molars were more affected with demarcated hypomineralization than incisors. the prevalence of severely affected teeth was 4.5%. molars were more severely affected than incisors. obese children had more severely affected teeth. further studies are suggested concerning the prevalence of mih in relation to socioeconomic status, water fluoridation, the morphological, etiological, epidemiological and clinical considerations, and management of mih. references 1. salih ba, khalaf ms. prevalence of molar-incisorhypomineralization among children attending pedodontic clinic of college of dentistry at baghdad university. j bagh coll dentistry 2012; 24(4): 121-5. 2. costa-silva cm, mialhe fl. considerations for clinical management of molar-incisor hypomineralization: a literature review. rev odonto cienc 2012; 27(4): 333-8. 3. weerheijm kl. molar incisor hypomineralisation (mih). eur j paediatr dent 2003; 4(3):114-20. 4. jalevik b. prevalence and diagnosis of molar-incisor hypomineralisation (mih): a systematic review. eur arch paediatr dent 2010; 11(2): 59-64. 5. alaluusua s. aetiology of molar-incisor hypomineralization: a systematic review. eur arch paediatr dent 2010; 11(2): 53-8. 6. lygidakis na , wong f, jälevik b, vierrou am, alaluusua s, espelid i. best clinical practice guidance for clinicians dealing with children presenting with molar-incisor-hypomineralisation (mih ): an eapd policy document. eur arch paediatr dent 2010; 11 (2): 75-81. 7. ghanim a, bagheri r, manton d. molar–incisor hypomineralisation: a prevalence study amongst primary schoolchildren of shiraz, iran. eur arch paediatr dent 2013 doi 10.1007/s40368-013-0067-y. 8. fagrell tg. molar incisor hypomineralization: morphological and chemical aspects, onset and possible etiological factors. swedish dent j (supplement) 2011; 216: 1-83. 9. william v, messer lb, burrow mf. molar incisor hypomineralization: review and recommendations for clinical management. pediatr dent 2006; 28(3): 22432. 10. costa-silva cm, jeremias f, souza jf, cassia loiolacordeiro r, santospinto l, cristina a. molar incisor hypomineralization: prevalence, severity and clinical consequences in brazilian children. international j paediatric dentistry 2010; 20: 426-434. 11. fteita d, ali a, alaluusua s. molar–incisor hypomineralization (mih) in a group of school-aged children in benghazi, libya. eur arch paediatr dent 2006; 7:92–5. 12. allazzam sm, el meligy oas, alaki sm. molar incisor hypomineralization, prevalence, and etiology. international j dentistry 2014; volume 2014, article id 234508, 8 pages. 13. lygidakis na. treatment modalities in children with teeth affected by molarincisor enamel hypomineralisation (mih): a systematic review. eur arch paediatr dent 2010; 11(2): 65-74. 14. biondi am, jordi mcl, cortese sg, álvarez l, salveraglio i, ortolani am. prevalence of molarincisor hypomineralization (mih) in chilfren seeking dental care at the schools of dentistry of the university of buenos aires (argentina) and university of la república (uruguay). acta odontol latinoam 2012; 25(2): 224-30. 15. wogelius p, haubek d, poulsen s. prevalence and distribution of demarcated opacities in permanent 1st molars and incisors in 6 to 8-year-old danish children. acta odontol scand 2008; 66(1): 58–64. 16. wogelius p, haubek d, poulsen s. prevalence and distribution of demarcated opacities in permanent 1st molars and incisors in 6 to 8-year-old danish children. acta odontol scand 2008; 66(1): 58–64. 17. lygidakis na, dimou g, briseniou e. molar-incisorhypomineralisation (mih). retrospective clinical study in greek children. i. prevalence and defect characteristics. eur arch paediatr dent 2008; 9(4): 200-6. j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 1 comparative study of the amount of apically extrusion of debris during root canal preparation using wave one™, trushape 3d™, hyflex™ cm and one shape™ instrumentation systems (an in vitro study) ali w. hadi d.d.s.(1) mohammed r. hameed b.d.s., m.sc., ph.d.(2) abstract background: many types of instruments and techniques are used in the instrumentation of the root canal system. these instruments and techniques may extrude debris beyond the apical foramen and may cause post-instrumentation complications. the aim of this study was to evaluate the amount of apically extruded debris resulted by using 4 types of nickel-titanium instruments (waveone, trushape 3d conforming files, hyflex cm, and one shape files) during endodontic instrumentation. materials and methods: forty freshly extracted human mandibular second premolar with straight canals and a single apex were collected for this study. all teeth were cut to similar lengths. pre-weighted glass vials were used as collecting containers. samples were randomly divided into four groups with 10 samples in each group: group a instrumentation by waveone reciprocating file, group b instrumentation by trushape 3d rotating files, group c instrumentation by hyflex cm rotating files and group d instrumentation by one shape rotating file. a total volume of 7 ml of sodium hypochlorite was used for irrigation in each sample. apical patency confirmed and maintained by a size #15 k-file. all canals were instrumented up to a size #25. after completion of endodontic instrumentation, vials were then stored in an incubator for 5 days at 68o c for dryness. then vials are weighted again, and the pre-weight subtracted from the post-weight, the weight difference resembled the amount of apically extruded debris from the apical foramen during root canal instrumentation. data obtained were statistically analysed by using anova and lsd tests. results: the results showed that the hyflex cm group (c) has statistical significant lowest apically extruded debris as compared to other groups of this study (p ≤0.05), while the trushape group (b) has statistical significant lowest apically extruded debris as compared to one shape group (d) and waveone group (a), while the waveone group (a) showed the highest value of apically extruded debris (p ≤0.01). the result showed that all groups resulted in apical extrusion of debris. significance: although all systems caused apical extrusion of debris and irrigant, continuous rotary instrumentation was associated with less extrusion as compared with the use of reciprocating file system. key words: debris extrusion, rotary instrumentation, niti instruments. (j bagh coll dentistry 2017; 29(1):1-8) introduction the main objectives of root canal instrumentation include a complete disinfection and debridement of the root canal system, in addition, to create a proper shape to attain a complete threedimensional obturation. a thorough preparing of the apical region has long been considered a crucial asset in the cleaning and shaping stage (1). in asymptomatic chronic periradicular lesion, there is a balance between the host defence and the infected canal microbiota. if this balance is disrupted by the extrusion of bacteria apically during instrumentation, an acute inflammatory response will occur in order to re-gain the equilibrium, which in turn could result in postoperative complications like flare-up, which is described by pain, swelling, or both (2). during the instrumentation procedure, debris such as necrotic pulp tissue, dentinal shavings, irrigants, bacteria and their by-products may be pushed beyond the apex onto the periradicular 1 master student. department of prosthodontics. college of dentistry, university of baghdad. 2 ass. professor, department of operative dentistry, college of dentistry, university of baghdad. tissues which could cause and inflammatory response, postoperative pain and possible delayed healing (3). cleaning and shaping of the root canal system is carried out mainly by step-back or crown-down techniques. hand and rotary instruments are used with either of these techniques. advanced instrument designs such as variable tapers, radial lands, different flute depths, cross-sections, and noncutting tips and the use of different operational techniques have been developed for the improvement of working safety, create a greater flare within preparation, shorten working time, and to provide a smoother and cleaner preparation to receive the final obturation (27). waveone niti file system is a reciprocating file claimed to complete the root canal instrumentation with only one file using a special reciprocating motion. the files are made of an alloy called m-wire which is created by an innovative thermal treatment and claimed to have superior j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 2 flexibility and cyclic fatigue resistance. the files are available in three sizes of 21/.06, 25/08, and 40/08 that are used in a special automated device (5). trushape 3d conforming files is a recent rotating system that have a unique s-shaped design that is claimed to allow the file to conform to irregular and larger shapes than the files original size, the file compresses in small areas and springs in wide areas and creates an envelope of motion inside the root canal, the system comes in four sizes 20/.06, 25/.06, 30/.06, and 40/.06 (6). the one shape file by micro mega (besanc on, france) is a single-file system, used in continuous clockwise rotation. these instruments have an innovative design with three different crosssectional areas over the entire length of the working part and have a variable pitch and a noncutting safety tip (7). the hyflex cm multiple-file system (coltene whaledent, cuyahoga falls, oh, usa) was developed for use in continuous rotation and is composed of a modified niti alloy (52 ni wt% versus 54.5–57 ni wt% in conventional niti alloys). this alloy undergoes controlled memory (cm) thermomechanical surface treatment, which increases the fatigue resistance by 150% and 390% compared with m-wire and non-surface treated conventional niti alloy, respectively. due to the lack of shape memory, this system enables visual functionality verification. the shape and strength of files with straightened spirals can be restored during autoclaving and reused, but files that do not return to their original shape should be discarded (8). the amount of debris may vary depending upon the instrumentation method, file size and file type. instrumentation should be performed in a manner that minimizes the amount of debris extruded into periapical tissues (9). although cleaning and shaping of the root canal are accomplished by instrumentation, it is essential that this should be accompanied by copious irrigation. this procedure not only “flushes out” pulpal debris and dentin chips, but also helps to lubricate endodontic instruments and facilitates their cutting action (10). the first attempt to quantify the amount of apically extruded debris has been made by vande visse and brilliant in 1975 (4). as aed generates an acute inflammatory reaction in the periapical tissues, it is considered as an important parameter to assess the efficacy of an instrumentation technique or instrument design during root canal preparation. also no studies have been conducted to determine the amount of debris extrusion resulting from the use of the new rotary instrument, trushape 3d. the aim of this study was to compare the amount of aed during root canal preparation using waveone™ reciprocating file compared with the rotary trushapetm 3d conforming files, one shapetm and hyflex™ cm files. materials and methods sample selection forty freshly extracted human mandibular second premolar teeth were collected from different specialized dental centers (teeth were extracted for orthodontic reasons and the patients age ranged from 20-30 years old). immediately after extraction, bone, calculus, stains and soft tissues on the tooth surface were removed manually with cumine scaler. each tooth was then radiographed bucco-lingually and proximally to confirm single canal and single apical foramen. teeth with calcification, open apices, severely curved canals, internal and external resorption were excluded from this study. all teeth were decoronated using a diamond disk under copious water to a length of 15 mm to achieve similar teeth lengths and a flat reference point (11). teeth were then stored in a 10% formalin solution for disinfection until the time of use and then stored in normal saline during the experiments. the external surface of the roots was covered with two layers of nail polish except for the last apical 1 mm fig. 1 figure 1: measurement of the length of the root with digital caliber. method of sample fixation and debris collection each glass vial was weighted without the rubber stopper with an electrical balance with a precision of 0.0001 before its use, the weight was recorded after having three identical readings. a rubber cap of a glass vial was adjusted for use by making a hole in the center and then a tooth was pushed through this hole up to the cementoenamel junction and then the tooth-cap complex was fitted on the glass vial, the apical part of the tooth was suspended within the vial which acted as a collecting container for extruded debris and irrigants. a bent gauge 25 needle was forced through the rubber stopper alongside the tooth surface to act as a draining cannula and to equalize the pressure between the inside and outside of the vial (12). fig. 2 j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 3 figure 2: tooth-rubber cap assembly fitted on glass vial with needle attachment. sample preparation endodontic access cavities were performed with endo access bur and a high speed handpiece under copious amount of water, pulp tissues were extirpated with a barbed broach, and apical patency was confirmed with a size #15 k-file (if the file passes freely through the foramen, then the specimen will be discarded). working length determination was made by subtracting 1 mm from the length of the 15mm long root to standardize the wl for all specimens at a 14mm. sample grouping the specimens were randomly divided into four groups (each group containing 10 samples) according to the type of instrumentation systems used:  group a: instrumentation with waveone reciprocating files.  group b: instrumentation with trushape 3d conforming files.  group c: instrumentation with hyflex cm files.  group d: instrumentation with one shape file. preparation of canals the sequences used in this study were done according to the manufacturer’s instructions for each system. all canals prepared to maf # 25. disposable side-vented navi tip needle with 30gauge was used for irrigation in this study. the needle tip was inserted passively and never allowed to bind as the irrigant was being slowly deposited into the canal and never allowed to reach more than 2mm from the wl (13). for standardization purposes the irrigation protocol was done using a total volume of 7-ml of sodium hypochlorite with a final flush of 3-ml. each file was used for 3 canals and then discarded (13). after completion of each canal instrumentation, the external surface of the root was irrigated with 2-ml of normal saline into the glass vial to collect any adhering debris. fig. 3 figure 3: washing the apex with normal saline group a: instrumentation with waveone single file in a reciprocation motion canal preparation performed by the waveone file according to the manufacturer’s instructions. the waveone program was chosen on the x-smart plus endodontic engine. the primary file was inserted and the rubber stopper at full working length. initial shaping was done with a gentle inward pecking motion, with short 2-3 mm amplitude strokes, to passively advance the file until it does not easily progress anymore. the file was then withdrawn, cleaned, then the canal was irrigated and checked for patency. the waveone file was then reinserted and the procedure is repeated until full working length is reached. final irrigation and patency checking was done. group b: rotary instrumentation with trushape 3d conforming files canal preparation performed by the trushape 3d conforming file according to the manufacturer’s instructions in the following sequence: the canal was flooded with irrigant then the first trushape file 20/0.06 with a yellow ring was introduced into the canal by using the x-smart plus endodontic engine at a speed of 300 rpm and torque at 3 n/cm with a gentle 2-5 mm in-and-out motion to shape the middle third, with a 2-3 mm amplitude in-and-out motion towards the apex. abrupt pecking motions were avoided. file was then withdrawn and its flutes were cleaned and the canal was irrigated and canal patency re-confirmed with a #15 k-file. the procedure is then repeated until working length was reached. the next file 25/0.06 with a red ring was then used in the same movement fashion until working length was reached then withdrawn once it has reached working length. canal was irrigated thoroughly and patency was re-confirmed. group c: rotary instrumentation with hyflex cm files canal preparation performed by the hyflex cm files according to the manufacturer’s instructions. speed of rotation was set to 500 rpm and torque at 2.5 n/cm on the endodontic engine. the orifice opener 25/0.08 was used first for the coronal preparation in a smooth in-and-out tipping motion. then the 20/0.04 file used in the same motion to full working length for apical preparation. then the j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 4 25/0.04 file was then used to full working length to finish apical preparation. finally, the 20/0.06 file was used to full working length for the middle segment preparation. after each file application the spirals of the file were inspected for straightening, the file was placed in hot water for about 10 seconds until it regains its original shape. group d: rotary instrumentation with one shape file canal preparation performed by the one shape files according to the manufacturer’s instructions. g1 file 12/0.03 was introduced into the canal in a slow downward movements in a free progression and without pressure motion to working length at 250-400 rpm and max torque of 1.2 n/cm. canal is then irrigated and g2 file 17/0.03 used to working length in the same fashion. canal was irrigated and patency checked with a size #15 k-file. one shape file was then used at 400 rpm and 2.5 n/cm with inand-out movement for about 2-3 mm without pressure, then the file is withdrawn and cleaned and canal irrigated and patency checked with #15 k-file. this is repeated until working length is reached. sample incubation and re-weighting after removing the tooth-cup assembly, the glass vials were then stored in an incubator at 68˚c for 5 days in order for water evaporation leaving only the extruded debris (14). then the vials were transmitted from the incubator to the electrical balance for re-weighting, the reading was recorded from three repeated readings. the weight of debris of each sample was calculated from subtracting the values of pre-weight from post-weight of the vial for each sample of all groups of this study. statistical analysis descriptive statistics including: minimum, maximum, mean and standard deviation were calculated for the mean for the groups of this study by using statistical package for social science spss (version 13.0) for windows (spss inc., chicago, il, usa). inferential statistics: including: 1. one-way analysis of variance test (anova) to find any statistically significant difference among the groups. 2. least significant difference test (lsd) to find any significant difference between the groups. results the results of this study showed that all groups resulted in extrusion of debris with different values. the mean values (in mg), and sd of aed for all groups are shown in table (1) and fig. 4 hyflex cm group (c) showed the lowest mean value of aed in comparison with other groups followed by trushape (b), one shape (d), groups respectively, while the waveone group (a) had the highest mean value. analysis of variance (anova) test was performed to identify the presence of any statistically significant difference among groups, table (2). anova test showed a very high significant difference among groups (p<0.05). the result of lsd test table (3) showed that there was a significant difference between group (a) waveone and group (b) trushape (p < 0.05). group (a) showed a very high significant difference (p ≤ 0.001) as compared with group (c) hyflex cm. and showed no significant difference as compared with group (d) one shape (p ≥ 0.05). while group (b) trushape showed a significant difference as compared with group (c) hyflex cm (p < 0.05). and showed no significant difference as compared with group (d) one shape (p ≥ 0.05). and group (c) hyflex cm show a high significant difference as ompared with group (d) one shape (p ≤ 0.01). table (1): the mean values of apically extruded debris (in mg) and sd for all groups. groups n mean sd a 10 0.369 0.0568 b 10 0.315 0.0345 c 10 0.267 0.0609 d 10 0.337 0.0284 j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 5 table 2: anova test for mean of apically extruded debris among groups. sum of squares (ss) df mean square (mf) f-test p-value between groups .055 3 .018 8.200 0.000 within groups .080 36 .002 total .135 39 table 3: lsd test for multiple comparisons between groups. groups mean difference (i-j) p-value sig. group a group b 0.053* 0.016 * group c 0.102* 0.000 ** group d 0.032 0.139 ns group b group c 0.048* 0.027 * group d -0.021 0.319 ns group c group d -0.070* 0.002 ** p ≥ 0.05 non-significant (ns) p < 0.05 significant (s) * p ≤ 0.01 high significant (hs) * * figure 4: mean values of apically extruded debris of all groups of this study. discussion the main objective of chemomechanical instrumentation is the total elimination of infected pulp tissue from the root canal, proper cleansing of the canal space is considered essential for success in endodontics. to achieve these objectives, pulpal remnants and debris must be removed from the root canal walls. mechanical instrumentation establishes an adequate canal shape, allowing easy access of irrigating solutions to the entire canal space and adequate obturation (15). 0 0.2 0.4 group a group b group c group d 0.369 0.315 0.267 0.337 mean of debris weight (in mg) j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 6 root canal instrumentation requires technical knowledge to be applied to the biological area, so as to obtain a well instrumented and disinfected canal without damage to its biological structure. since the root canal includes the space that contains the pulpal organ, one of its ends is in the pulp chamber and the other corresponds to the apical foramina. thus, instrumentation of root canals can cause extrusion of material through the foramen by virtue of the anatomy of the canal itself (16). during root canal treatment, debris and irrigant may extrude from the apical foramen and cause postinstrumentation pain or flare-up. these debris mostly contain pulp tissue remnants, dentin chips, microorganisms, necrotic tissue, and root canal irrigants. when debris is pushed out of apical foramina, it will result in an ag-ab reaction. this reaction will generate an acute inflammatory reaction in the periapical tissues, and cause damage to the cell membrane resulting in prostaglandins release, bone resorption, amplification of the kinin system and ultimately pain for patient (17) (2). many studies have looked at various aspects of apically extruded debris and irrigants. the results have shown that preparation up to the apex, the diameter of apical patency, the amount of irrigant used, formation of a dentine plug, the use of stepback versus crown-down technique, and the use of conventional hand filing versus rotary motion, all have a correlation to the amount of extruded debris (18). irrigation or chemical debridement is accepted as being a necessary aid in the chemomechanical cleansing of the root canal as irrigation assists in debris removal. more debris are removed when greater quantities of irrigating solutions are used. furthermore, the proximity of the irrigating needle to the apex plays an important role in removing the canal debris (19). beeson et al., (20) in 1998 reported that, when the instrumentation was performed to the apical foramen, significantly more debris was forced apically than when instrumentation was done 1 mm short. the present study showed that waveone single file system has the maximum amount of apical debris and irrigant extrusion when compared to trushape, hyflex cm, and one shape rotary files, this might be due to the reciprocation movement in waveone system is formed by a wider cutting angle and smaller release angle. while rotating in the release angle the flutes will not remove debris but push them apically. furthermore, the waveone file shows radial lands, and this feature can reduce the coronal debris removal capacity, enhancing apical debris extrusion. moreover, waveone file is quite big, rigid with an increased taper (0.08 taper) which is directed to reach the apex this result agrees with webber j. et al., 2011. (21). moreover, waveone files due to their reciprocating and in-and-out filing motion, may act as a piston, extruding more debris and irrigant than rotary instrumentation techniques. while the file with continuous rotation act like a screw conveyor improving transportation of dentin chips and debris coronally (11). also this result agrees with many studies. gianluca et al., (22) in 2013 evaluated the incidence of postoperative pain when waveone, tf15, and tf adaptive systems were used for chemomechanical preparation for root canals. they measured that the incidence of postoperative pain was significantly higher with the waveone single file reciprocating system. surakanti jr et al., (5) in 2014 made a comparative evaluation of apically extruded debris during root canal preparation using waveone, protaper, hyflex and rotary systems. and showed that the hyflex system was associated with less amount of apically extruded debris compared to protaper universal and waveone. nevares g et al., (23) in 2015 compared the amount of apically extruded debris between waveone, reciproc and hyflex cm. and reported that hyflex cm system had the lowest mean of apically extruded debris followed by waveone and the reciproc files. singh a et al., (24) in 2015 compared the amount of aed and between waveone, protaper hand and m two files. waveone single file reciprocating system showed the maximum amount of apical debris and irrigant extruded when compared to protaper hand and m-two rotary systems. the result of this study showed that the one shape file showed less amount of aed than the waveone but more than the trushape and hyflex cm files. one shape file has three variable crosssections along the length of the blade. towards its tip, the file has a variable three-cutting-edge design. in the middle, the cross-section progressively changes from three to two cutting edges, and towards the shaft the blade has two cutting edges. the file has an aggressive cutting ability which removes a substantial amount of dentin in a relatively shorter period of time, but they are unable to displace the debris coronally and hence, enhance apical extrusion of debris (11). this result agrees with nayak g et al., (25) in 2014 who made an evaluation of aed and irrigant using the one shape, waveone and reciproc single file systems. they reported that the one shape rotating file showed the lowest amount of apically extruded debris and irrigant as compared to reciproc and waveone reciprocating files. the trushape system revealed an amount of apically extruded debris less than one shape and waveone but more than hyflex cm files. these files have a unique s shaped design which produces and envelope of motion that may help in the auguring of debris coronally. in addition, it acts as a spring, so in tight spaces the file compresses and in http://www.ncbi.nlm.nih.gov/pubmed/?term=singh%20a%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=nayak%20g%5bauth%5d j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 7 wide areas it springs to convey larger areas of the original file size. the file’s lesser maximum flute diameter or 0.08 mm might be a factor in the extrusion of debris apically. according to the results of this study, hyflex system showed the least amount of aed comparing to other systems, this result is in agreement with surakanti jr et al., 2014 (5) who showed that hyflex cm system had the lowest mean of aed in their study. hyflex cm™ files have multiple crosssectional designs, some instruments (.06/20, .04/30 and .04/40) have triangular cross section with three blades and three flutes, others (.04/20 and .04/25) have quadrangular cross section with four blades and four flutes. the cutting profile of each hyflex cm™ file facilitates penetration in the canal and presents a root canal shape corresponding with the original anatomy (22). this system has a taper of 0.04 % which is less than all other systems which could be a cause of less extrusion apically because the amount of the cut dentine is less. additionally, capar et al. (2014) (26) found that during root canal instrumentation with the hyflex cm system, the spirals unwound in 95% of the instruments (114/120 uses). and 80% of instruments were distorted. the lower extrusion rate in the hyflex group could be related to this design modification, which could reduce the cutting efficiency and the amount of collected debris conclusions under the experimental conditions of this in vitro study, the following conclusions can be drawn: the result showed that all groups resulted in apical extrusion of debris. the hyflex cm group (c) showed the lowest amount of apically extruded debris compared to other groups, followed by trushape group (b), one shape group (d) respectively. waveone group (a) showed the highest value of apically extruded debris. references 1. logani a, shah n. apically extruded debris with three contemporary ni-ti instrumentation systems: an ex vivo comparative study. ijdr. 2008; 19(3):182-185. 2. siqueira jf. microbial causes of endodontic 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incidence of dentinal defects after root canal preparation: reciprocating versus rotary instrumentation. j endod. 2013; 39(4):501-4. 8. braga lcm, faria silva ac, buono vtl, and de azevedo bahia mg, “impact of heat treatments on the fatigue resistance of different rotary nickeltitanium instruments. j endod 2014; 40(9): 1494–7. 9. reddy sa, hicks ml. apical extrusion of debris using two hand and two rotary instrumentation techniques. j endod. 1998; 24(3):180-183. 10. brown dc, moore bk, brown ce, newton cw. an in vitro study of apical extrusion of sodium hypochlorite during endodontic canal preparation. joe.1995;21:587–1. 11. burklein s, schafer e. apically extruded debris with reciprocating single file and full-sequence rotary instrumentation systems. j endod. 2012a; 38(6):850852. 12. tasdemir t, er k, celik d, aydemir h. an in vitro comparison of apically extruded debris using three rotary nickel-titanium instruments. jds. 2010; 5(3):121-125. 13. parirokh m, jalali s, haghdoost aa, abbott pv. comparison of the effect of various irrigants on apically extruded debris after root canal preparation. j endod. 2012; 38(2):196-199. 14. sheetal b ghivari, girish c kubasad, manoj g chandak, and nr akarte. apical extrusion of debris and irrigant using hand and rotary systems: a comparative study. j conservndent. 2011;14(2): 187190. 15. zmener o, pameijer ch, alvarez serrano s, hernandez sr. cleaning efficacy using two enginedriven systems versus manual instrumentation in curved root canals: a scanning electron microscopic study. j endod. 2011 sep;37(9):1279-82. 16. vansan lp, pécora jd, da costa wf, silva rg, savioli rn. comparative in vitro study of apically extruded material after four different root canal instrumentation techniques. braz dent j. 1997;8(2):79-83. 17. al–omari mao, dummer pmh. canal blockage and debris extrusion with eight preparation techniques. joe. 1995; vol 2(3):154–8. 18. hegde mn. comparison of the amount of apical extrusion of bacteria following the use of different instrumentation techniques an in vitro study. nitte univ j sci. 2011; 1:27–32. 19. abou-rass m, piccinino m. the effectiveness of four clinical irrigation methods on the removal of root canal debris. oral surg oral med oral pathol.1982;54:323–8. 20. beeson t, hartwell g, thornton j, gunsolley j. comparison of debris extruded apically in straight http://www.ncbi.nlm.nih.gov/pubmed/?term=surakanti%20jr%5bauthor%5d&cauthor=true&cauthor_uid=24778507 http://www.ncbi.nlm.nih.gov/pubmed/?term=venkata%20rc%5bauthor%5d&cauthor=true&cauthor_uid=24778507 http://www.ncbi.nlm.nih.gov/pubmed/?term=vemisetty%20hk%5bauthor%5d&cauthor=true&cauthor_uid=24778507 http://www.ncbi.nlm.nih.gov/pubmed/?term=dandolu%20rk%5bauthor%5d&cauthor=true&cauthor_uid=24778507 http://www.ncbi.nlm.nih.gov/pubmed/?term=dandolu%20rk%5bauthor%5d&cauthor=true&cauthor_uid=24778507 http://www.ncbi.nlm.nih.gov/pubmed/?term=jaya%20nk%5bauthor%5d&cauthor=true&cauthor_uid=24778507 http://www.ncbi.nlm.nih.gov/pubmed/?term=thota%20s%5bauthor%5d&cauthor=true&cauthor_uid=24778507 http://www.ncbi.nlm.nih.gov/pubmed/?term=comparative+evaluation+of+apically+extruded+debris+during+root+canal+preparation+using+protaper%e2%84%a2%2c+hyflex%e2%84%a2+and+waveone%e2%84%a2+rotary+systems https://www.dentsply.com/content/dam/dentsply/pim/manufacturer/endodontics/glide_path__shaping/rotary__reciprocating_files/3d_conforming/trushape_3d_conforming_files/trushape-3d-conforming-files-brochure-2vkhexu-en-1504.pdf https://www.dentsply.com/content/dam/dentsply/pim/manufacturer/endodontics/glide_path__shaping/rotary__reciprocating_files/3d_conforming/trushape_3d_conforming_files/trushape-3d-conforming-files-brochure-2vkhexu-en-1504.pdf https://www.dentsply.com/content/dam/dentsply/pim/manufacturer/endodontics/glide_path__shaping/rotary__reciprocating_files/3d_conforming/trushape_3d_conforming_files/trushape-3d-conforming-files-brochure-2vkhexu-en-1504.pdf https://www.dentsply.com/content/dam/dentsply/pim/manufacturer/endodontics/glide_path__shaping/rotary__reciprocating_files/3d_conforming/trushape_3d_conforming_files/trushape-3d-conforming-files-brochure-2vkhexu-en-1504.pdf https://www.dentsply.com/content/dam/dentsply/pim/manufacturer/endodontics/glide_path__shaping/rotary__reciprocating_files/3d_conforming/trushape_3d_conforming_files/trushape-3d-conforming-files-brochure-2vkhexu-en-1504.pdf http://www.ncbi.nlm.nih.gov/pubmed/?term=ghivari%20sb%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=kubasad%20gc%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=chandak%20mg%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=chandak%20mg%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=akarte%20n%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/21846548 http://www.ncbi.nlm.nih.gov/pubmed/21846548 http://www.ncbi.nlm.nih.gov/pubmed/21846548 http://www.ncbi.nlm.nih.gov/pubmed/21846548 http://www.ncbi.nlm.nih.gov/pubmed/?term=vansan%20lp%5bauthor%5d&cauthor=true&cauthor_uid=9590930 http://www.ncbi.nlm.nih.gov/pubmed/?term=p%c3%a9cora%20jd%5bauthor%5d&cauthor=true&cauthor_uid=9590930 http://www.ncbi.nlm.nih.gov/pubmed/?term=da%20costa%20wf%5bauthor%5d&cauthor=true&cauthor_uid=9590930 http://www.ncbi.nlm.nih.gov/pubmed/?term=silva%20rg%5bauthor%5d&cauthor=true&cauthor_uid=9590930 http://www.ncbi.nlm.nih.gov/pubmed/?term=silva%20rg%5bauthor%5d&cauthor=true&cauthor_uid=9590930 http://www.ncbi.nlm.nih.gov/pubmed/?term=savioli%20rn%5bauthor%5d&cauthor=true&cauthor_uid=9590930 http://www.ncbi.nlm.nih.gov/pubmed/?term=vansan+1997 http://www.ncbi.nlm.nih.gov/pubmed/?term=vansan+1997 j bagh college dentistry vol. 29(1), march 2017 comparative study of restorative dentistry 8 canals: conventional filing versus profile.04 taper series 29. j endod. 1998; 24:18–22. 21. webber j, machtou p, pertot w, kuttler s, ruddle c, west j. the waveone single-file reciprocating system. roots. 2011; 1:28–33. 22. testarelli l, plotino g, al-sudani d, vincenzi v, giansiracusa a, grande nm, gianluca gambarini g. bending properties of a new nickel–titanium alloy with a lower percent by weight of nickel. journal of endodontics 2011; 37, 1293– 5. 23. nevares g, xavier f, gominho l, cavalcanti f, cassimiro m, romeiro k, alvares p, queiroz g, sobral ap, gerbi a, silveira m, and albuquerque d. apical extrusion of debris produced during continuous rotating and reciprocating motion. scientific world journal 2015; 264-7. 24. singh a, arunagiri d, pushpa s, sawhny a, misra a, khetan k. apical extrusion of debris and irrigants using prota per hand, mtwo rotary and waveone single file reciprocatingsys tem: an ex vivo study. j conserv dent. 2015;18(5):405-8. 25. nayak g, singh i, shetty s, and dahiya s. evaluation of apical extrusion of debris and irrigant using two new reciprocating and one continuous rotation single file systems. j dent (tehran). 2014; 11(3):302-9. 26. capar i. d., arslan h., akcay m., and ertas h., “an in vitro comparison of apically extruded debris and instrumentation times with protaper universal, protaper next, twisted file adaptive, and hyflex instruments,” journal of endodontics. 2014;40(10):1638-1641. 27. kocak s, kocak mm, saglam bc, turker sa, sagsen b, er o. apical extrusion of debris using self-adjusting file, reciprocating single-file, and 2 rotary instrumentation systems: j endod. 2013; 39(10):1278-80. http://www.ncbi.nlm.nih.gov/pubmed/?term=singh%20a%5bauthor%5d&cauthor=true&cauthor_uid=26430306 http://www.ncbi.nlm.nih.gov/pubmed/?term=arunagiri%20d%5bauthor%5d&cauthor=true&cauthor_uid=26430306 http://www.ncbi.nlm.nih.gov/pubmed/?term=pushpa%20s%5bauthor%5d&cauthor=true&cauthor_uid=26430306 http://www.ncbi.nlm.nih.gov/pubmed/?term=sawhny%20a%5bauthor%5d&cauthor=true&cauthor_uid=26430306 http://www.ncbi.nlm.nih.gov/pubmed/?term=misra%20a%5bauthor%5d&cauthor=true&cauthor_uid=26430306 http://www.ncbi.nlm.nih.gov/pubmed/?term=misra%20a%5bauthor%5d&cauthor=true&cauthor_uid=26430306 http://www.ncbi.nlm.nih.gov/pubmed/?term=khetan%20k%5bauthor%5d&cauthor=true&cauthor_uid=26430306 http://www.ncbi.nlm.nih.gov/pubmed/?term=apical+extrusion+of+debris+and+irrigants+using+protaper+hand%2c+m-two+rotary+and+waveone+single+file+reciprocating+system%3a+an+ex+vivo+study http://www.ncbi.nlm.nih.gov/pubmed/?term=apical+extrusion+of+debris+and+irrigants+using+protaper+hand%2c+m-two+rotary+and+waveone+single+file+reciprocating+system%3a+an+ex+vivo+study http://www.ncbi.nlm.nih.gov/pubmed/?term=nayak%20g%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=singh%20i%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=shetty%20s%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=dahiya%20s%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=.+evaluation+of+apical+extrusion+of+debris+and+irrigant+using+two+new+reciprocating+and+one+continuous+rotation+single+file+systems http://www.ncbi.nlm.nih.gov/pubmed/?term=ko%c3%a7ak%20s%5bauthor%5d&cauthor=true&cauthor_uid=24041391 http://www.ncbi.nlm.nih.gov/pubmed/?term=ko%c3%a7ak%20mm%5bauthor%5d&cauthor=true&cauthor_uid=24041391 http://www.ncbi.nlm.nih.gov/pubmed/?term=sa%c4%9flam%20bc%5bauthor%5d&cauthor=true&cauthor_uid=24041391 http://www.ncbi.nlm.nih.gov/pubmed/?term=t%c3%bcrker%20sa%5bauthor%5d&cauthor=true&cauthor_uid=24041391 http://www.ncbi.nlm.nih.gov/pubmed/?term=t%c3%bcrker%20sa%5bauthor%5d&cauthor=true&cauthor_uid=24041391 http://www.ncbi.nlm.nih.gov/pubmed/?term=sa%c4%9fsen%20b%5bauthor%5d&cauthor=true&cauthor_uid=24041391 5. zainab f.doc j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 25 an evaluation of the efficacy of different gingival retraction materials on the gingival tissue displacement (a comparative in vivo study) zainab m. dawood, b.d.s.(1) manhal a. majeed, b.d.s., m.sc., ph.d.(2) abstract background: an accurate adaptation of the crown to the finish line is essential to minimize cement dissolution and to preserve periodontium in fixed partial denture cases. an accurate adaptation of crown is possible only when preparation details are captured adequately in the impression and transferred to cast. for these reasons, gingival displacement is necessary to capture subgingival preparation details.the aim of the present study is to measure in vivo the horizontal displacement of the gingival sulcus obtained by using three new cordless retraction materials (magic foam cord®, racegel and astringent retraction paste) in comparison to medicated retraction cord. materials and method: thirty-two patients requiring porcelain fused to metal fixed partial denture for replacement of a missing maxillary posterior tooth (either one of thepremolars or the first molar). the patients are randomly divided into four groups of eight patients each according to the type of gingival retraction material used as follows: group i: medicated retraction cord (racemic epinephrine hydrochloride 0.3 ± 0.2 mg per inch of cord, #00), group ii: magic foam cord® (expanding polyvinyl siloxane), group iii: racegel (25% aluminum chloride gel) and group iv: astringent retraction paste (15% aluminum chloride paste). three depth orientation grooves were prepared in the buccal and palatal surfaces of a maxillary premolar parallel with the long axis of the tooth, extending from the middle third to the gingival third with the level of the free gingiva using a flat-ended diamond fissure bur. impression of the gingival sulcus was then made using monophase polyether impression material (impregum™ penta™ soft, 3m espe, germany), before and after gingival retraction with either of the aforementioned gingival retraction materials. the sulcus width, before and after gingival retraction was measured on the master cast (in µm), after its sectioning longitudinally bucco-palatally at the middle of the prepared grooves using a rotary diamond disc. the measurement carried out by using digital microscope (dino-lite)at a magnification of 230x. the horizontal gingival displacement (the distance from the end of each prepared groove to the crest of the gingiva) measured by subtracting the gingival sulcus width after retraction from that before retraction. results: the findings of the present study showed that the highest mean of horizontal gingival displacement is recorded by group iv (astringent retraction paste) (250.7900 µm), whereas the lowest mean of horizontal gingival displacement is recorded by group iii (racegel) (78.0988 µm). one-way anova test showed statistically highly significant differences among groups (p< 0.01). least significant difference test (lsd test) was also used to make multiple comparisons among groups and revealed a statistically highly significant difference between each two groups (p< 0.01). conclusion: the two new gingival retraction pastes (astringent retraction paste and magic foam cord®) could be used for gingival retraction as alternatives to medicated retraction cord. they offer advantages of simplified placement technique and shorter application time with greater gingival retraction. meanwhile, the use of racegel alone is not recommended for gingival retraction since it provides the least gingival displacement. key words: gingival tissue, retraction paste, medicated retraction cord. (j bagh coll dentistry 2015; 27(4):25-31). introduction the relationships between a fixed partial denture and the surrounding hard and soft tissue should be considered crucial for long-term success. a fixed partial denture requires an accurate impression that records the location of the finish line of the prepared tooth and a portion of the apical uncut tooth structure. this is important so that the restoration has a suitable emergence profile with well-adapted and smooth gingival margins. an accurate adaptation of the crown to the finish line is essential to minimize cement dissolution and to preserve periodontium in fixed partial denture cases. (1) master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. an accurate adaptation of crown is possible only when preparation details are captured adequately in the impression and transferred to the cast. for these reasons, gingival displacement is necessary to capture subgingival preparation details.(1) elastomeric impression materials are popular due to their high degree of accuracy in registering details. however, most of these materials have an inherent lack of wettability that may prevent adequate registration of soft and hard tissue details. therefore, the control of fluids in the gingival sulcus is mandatory, particularly when hydrophobic impression materials are used, as the sulcular fluid can lead to a deficient impression of the crucial finish line.(2) there are different techniques for gingival displacement, including: mechanical retraction, chemo-mechanical retraction, displacement pastes j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 26 and surgical retraction techniques.(3) the mechanical method of gingival displacement using retraction cord has been a standard for several years. it acts by physically pushing the gingival margin away from the finish line, but its effectiveness is limited because of its inability to control the sulcular fluid seepage. the chemomechanical method using cords impregnated in hemostatic agents is the most commonly advocated. it acts by physically pushing the gingival margin away from the finish line and its ability to control the sulcular fluid infiltration from the walls of the gingival sulcus. however, the placement of the cords into the gingival sulcus may cause slight trauma to the sulcular epithelium and is also time consuming.(2) in an attempt to be a convenient, fast and effective needed for gingival retraction materials, several retraction paste systems have entered the dental marketplace. providing a proper and simplified placement technique, these products are easy to use and can be gentler than cord to the gingival tissues. all currently available paste systems have a very similar placement protocol.(4) most of these materials contain aluminum chloride in different concentrations for hemostasis and claimed to provide blood-free retraction, making capturing an accurate impression easy, simple and predictable. each system uses a slightly different delivery system, has different consistencies and may include specially designed accoutrements to aid in getting the material into the sulcus and keeping the tissue dry.(4) magic foam cord® gingival retraction system is one of these new cordless paste gingival retraction systems introduced by coltène/whaledent. magic foam cord® is the first expanding vinyl polysiloxane material, which displaces the gingival tissue without being potentially traumatic and less time-consuming when compared with retraction cord.(5) racegel is another one of these cordless paste gingival retraction systems introduced by septodont. it is a flavored gel-like product containing 25% aluminum chloride and exhibits thermo-viscosifying properties.(4) recently, 3m espe has introduced their astringent retraction paste, containing 15% aluminum chloride, which offers several improvements over other delivery systems. the material is dispensed in hygienic unit dose capsules. its placement tip is finer than those of the other systems and has a soft edge tip giving easy access to the gingival sulcus, especially in interproximal regions.(4) however, there is no available study in the literature coping with the tissue displacing efficacy of these new retraction pastes; therefore, the present study is conducted. materials and methods patient selection: thirty-two patients ages between 25-55 years requiring porcelain fused to metal fixed partial denture for replacement of a missing maxillary posterior tooth (either one of thepremolars or the first molar) recruited from those patients attending the postgraduate clinic of the department of conservative dentistry, college of dentistry, university of baghdad are selected. all patients had good oral hygiene, free of gingival inflammation, normal gingival sulcus depth of 2mm(6) and with well-aligned abutment teeth were with no rotation, drifting or crowding.(7) it is worth to mention that all the clinical and laboratory steps, starting from the pre-operative impression to the sectioning and even the microscopical examination were performed by the same operator (i.e., the researcher herself).(7, 8) pre-operative impression: a pre-operative impression was taken for each patient using chromatic alginate hydrocolloid impression material (fast setting) (tropicalgin, zhermack, italy) and disposable rim lock plastic impression tray (position™ tray, 3m espe, germany). the pre-operative impression was poured immediately(9) with the type i gypsum product (plaster of paris) to obtain a diagnostic castwhich was used toconstruct a special tray. fabrication of custom tray (special tray): for each patient, two special trays were fabricated to take two final impressions: one before gingival retraction and the another after gingival retraction. a special tray (half arch) was constructed on the diagnostic cast to act as a carrier for the impression material.(2) the special tray was extended from the central incisor to the last molar on the working side and provided a 2mm space for the impression material with stoppers. it was constructed by using photopolymerized acrylic resin. sample grouping: the thirty-two patients were randomly divided into four groups of eight patients each according to the type of gingival retraction material that would be used as follows: group i: medicated retraction cord (ultrapak® etm, ultradent products, inc., usa). group ii: magic foam cord®(coltène/whaledent ag, switzerland). group iii:racegel (septodont, france). j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 27 group iv: astringent retraction paste(3m espe, germany). reference groove preparation: three depth orientation grooves were then prepared in the pre-drawn lines parallel to the long axis of the tooth extending from the middle to the gingival third at the level of the free gingiva using a flat-ended diamond fissure bur no. (6847kr) (komet, germany) followed by a bur no. (8847kr) (komet, germany) for finishing in a high speed air turbine hand-piece with water coolant. the width and depth of each groove were 1mm which corresponding to the diameter of the burs used for preparation and finishing. these grooves would serve as a reference for measurement of the horizontal displacement of the gingival tissue. final impression: after the preparation of the depth orientation grooves, two final impressions were taken for each patient using monophase polyether impression material (medium consistency) (impregum™ penta™ soft, 3m espe, germany) and the previously constructed special tray: the first one without doing gingival retraction, which would serve as a control to give a baseline measurement of the sulcus width.(8) the second final impression was taken after doing gingival retraction with either of the aforementioned gingival retraction materials and then poured with type iv die stone to measure the horizontal displacement of the gingival tissue on the stone cast after its sectioning.(6,10) gingival retraction procedure: group i (medicated retraction cord group) in group i, the gingiva was retracted with medicated retraction cord (ultrapak® etm, ultradent products, inc., usa) following the manufacturer’s instructions. it was placed in the sulcus from mesio-palatal to the mesio-buccal by using a cord packer with serrated circular heads, then left in place for 10minutes, then removed gently with a dental tweezer and the gingival sulcus was gently dried with an air syringe according to the manufacturer’s instructions; the final impression was then taken. group ii (magic foamcord® group) in group ii, the gingiva was retracted with magic foam cord® (polyvinylsiloxane, addition type silicone elastomer) (coltène/whaledent ag, switzerland) following the manufacturer’s instructions. magic foam cord®, in a sufficient amount, was then slowly injected into the sulcus from mesio-buccal to the mesio-palatalwith the tip parallel to the long axis of the tooth and then the comprecap anatomic was placed above it and the patient was asked to bite on the comprecap anatomic.(7,8) the comprecap anatomic was comfortably held in place under biting pressure for 5minutes. both the magic foam cord® and comprecap were then removed in one piece(7) and the sulcus was washed with an air/water spray to remove any residue of retraction material according to the manufacturer’s instructions and final impression was then taken. group iii (racegel group): in group iii, the gingiva was retracted with racegel retraction material (septodont, france) following the manufacturer’s instructions. racegel was applied directly into the sulcus carefully, following the contour of the prepared tooth from mesio-buccal to the mesio-palatal with the tip parallel to the long axis of the tooth.(7) it was kept in place for 2minutes; the gel was then completely removed with an air-water spray and gently dried with an air syringe according to the manufacturer’s instructions, the final impression was then taken. group iv (astringent retraction pastegroup): in group iv, the gingiva was retracted with the astringent retraction paste (3m espe, germany) following the manufacturer’s instructions. the retraction paste was then slowly injected into the sulcus from mesio-buccal to the mesio-palatal with the tip parallel to the long axis of the tooth.(7) after being in place for 2minutes, the retraction paste was completely removed from the sulcus by washing with an air-water spray and gently dried with an air syringe according to the manufacturer’s instructions and final impression was then taken andpoured with type iv die stone to obtain the master cast. sectioning and microscopical examination: the master cast was fixed to the base of the modified dental surveyor with the fixing bar touched the edentulous area of the master cast for stabilization of the master cast during sectioning; the position of the base of the modified dental surveyor was then adjusted in such a way that a rotary diamond disc (0.27mm in thickness, 4.5 cm in diameter) was parallel to the drawn lines. the tooth was then sectioned longitudinally buccopalatally followingthese lines, using a rotary diamond disc with a straight hand-piece j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 28 (belmont) mounted in a modified dental surveyor (bego).(6) after sectioning, the sectioned specimen was painted with a blue pencil to give better contrast to distinguish the edge of the reference groove and crest of the gingiva during microscopical examination,followed by linear measurement of the horizontal width of the gingival sulcus from the end of each prepared groove to the crest of the gingiva, under a digital microscope (dino-lite) at a magnification of 230x, which was connected to the computer to capture the image. the flexible arm of the digital microscope was adjusted in such a way that the digital microscope was perpendicular on the sectioned specimens with 1.5cm distance when capturing the images. image analysis software (image j) was used to measure the width of the gingival sulcus at these three lines buccally and palatally, which was calculated in pixels.(11, 12) the image analysis measurements in pixels were calibrated using the image of a (1mm) increment taken at the same focal length and input into (image j) by the option of set scale(13) that converted all calculated reading into (µm), followed by quantitative measurement of the horizontal distance (in µm) from the end of the prepared groove to the crest of the gingiva, before and after retraction of the gingival tissue. the difference of sulcus width (before and after retraction for buccal and palatal grooves) was measured for each patient, then the mean for each group was taken and used for comparison of significance among the groups. results descriptive statistics: the descriptive statistics, which included the mean, standard deviation, minimum and maximum values, which were calculated for the four groups as shown in (table 1) and (figure 1). the highest mean value of horizontal gingival displacement recorded in the present study was in group iv (astringent retraction paste)at around (250.7900 µm), whereas group iii (racegel) showed the lowest mean value of horizontal gingival displacement which was around (78.0988 µm). inferential statistics: comparison of significance among the different groups was done by using one-way anova test at a level of significance of (0.05). anova test revealed a statistically highly significant difference among groups (p< 0.01) as reported in (table 2). further, comparisons among groups were done using the least significant difference test (lsd test) to see where the significant difference occurred as reported in (table 3). lsd test results showed that there were statistically highly significant differences in gingival retraction between all groups (group i, group ii, group iii and group iv) when compared with each other (p< 0.01). table (1): descriptive statistics of horizontal gingival displacement for the different groups measured in micrometer. groups n mean sd min max group i 8 100.6296 ±14.23008 79.50 119.16 group ii 8 150.6097 ±15.72547 126.60 171.04 group iii 8 78.0988 ±9.29107 67.36 95.73 group iv 8 250.7900 ±22.04308 224.59 282.68 figure 1: bar-chart graph showing the mean values of the horizontal gingival displacement in (µm) of the four groups. h or iz on ta l g in gi va l d is pl ac em en t (µ m ) j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 29 table 2: anova test for comparison of significance among the four groups. sum of squares df mean square f sig. between groups 141339.974 3 47113.325 184.395 0.000 (hs) within groups 7154.047 28 255.502 total 148494.021 31 table 3: lsd test for comparison of significance between each two groups. groups mean difference s.e. sig. group i group ii -49.98013 7.99221 0.000 (hs) group iii 22.53088 7.99221 0.009 (hs) group iv -150.16038 7.99221 0.000 (hs) group ii group iii 72.51100 7.99221 0.000 (hs) group iv -100.18025 7.99221 0.000 (hs) group iii group iv -172.69125 7.99221 0.000 (hs) discussion the objective of the present project is to study in vivo the tissue displacing efficacy of three new different gingival retraction pastes in comparison to the medicated retraction cord, which has long been used and considered as a standard technique to obtain gingival retraction. all the tested materials (medicated retraction cord, magic foam cord®, racegel and astringent retraction paste) share the property of being placed in the gingival sulcus of the prepared tooth, but they differ in their chemical composition, mode of action and time of placement. the main advantage of using a cord in the current study is affordable and it could achieve varying degrees of retraction depending on its size. thus, medicated retraction cord is considered as a standard. however, improper handling of cords might lead to gingival recession and marginal exposure of the prosthesis, which may negatively affect esthetics. moreover, it has been reported by different researchers that the retraction procedure is inconvenient, timeconsuming and uncomfortable for the patient.(14) on the other hand, from a clinical point of view, all gingival retraction pastes are easier to place and require shorter application time when compared with the retraction cord. in addition, from a periodontal point of view, retraction pastes had been found to be better than cords when assessed histologically as reported by phatale et,al.(7); they respect the periodontium. the methodology used in the present study for assessing the tissue displacing efficacy of the gingival retraction materials by taking two impressions (pre/post-retraction) has been reported by different researchers. however, the only difference among these studies is that some researchers assessed the tissue displacing efficacy directly on the impression after its sectioning,(2, 8) while others assessed it on the cast obtained from the pre/post-retraction impressionsafter its sectioning.(6, 10) in the present study, the tissue displaying efficacy of the tested materials was assessed on the sectioned stone casts rather than on the impression itself since distortion and tearing of the impression might occur during sectioning. comparisons among groups: in present study, the statistically highly significant differences in the horizontal displacement of the gingival tissues produced by the different materials could be attributed to the differences in the chemical composition, mode of action, consistency and application time of these materials. the least gingival displacement shown by racegel (group iii) which was statistically highly significant when compared with all other groups could be attributed to the low consistency of the material as it is a gel form and its short application time (2 minutes). this means that the material might act by chemical means only depending on the 25% aluminum chloride in its formulation, which was eased into the intracrevicular space beneath the gingival margin owing to its gel consistency and fine application tip, shrinking the gingival tissues rather than mechanically pushing the sulcus away due to its low consistency. moreover, the short application time recommended by the manufacturer might not give enough time for adequate retraction but only for hemostasis. on the other hand, the greater gingival displacement shown by the medicated retraction cord (group i) than racegel could be due to the difference in the technique of gingival retraction (chemo-mechanical method) and longer application time (10 minutes). this means that the j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 30 material might act mechanically, pushing the sulcus away and stretched the circumferential periodontal fibers and by chemical means depending on epinephrine, which provided prolonged gingival vasoconstriction.(15) moreover, the long application time recommended by the manufacturer might give enough time for retraction and hemostasis. however, the horizontal displacement produced by the medicated retraction cord was less than that produced by magic foam cord® (group ii) and astringent retraction paste (group iv) with statistically highly significant differences. this could be attributed to that magic foam cord® contains expanding type polyvinyl siloxane material which generated hydrogen gas during setting and induced expansion. this means that the material might act by mechanical means depending on expanding type polyvinyl siloxane material that mechanically pushing the sulcus away due to its higher consistency and this was aided by the pressure exerted by the comprecap. moreover, the longer application time recommended by the manufacturer (5 minutes versus 2 minutes for racegel) might give enough time for adequate retraction. the greatest gingival displacement produced by astringent retraction paste (group iv) which was statistically highly significant when compared with all other groups could be attributed to its thicker consistency than racegel and magic foam cord® owing to its kaolin content and its fine application tip (1mm in diameter) which might allow the material to be inserted deeper in the sulcus. in addition to the thicker consistency, astringent retraction paste contains polydimethylsiloxane and 15% aluminum chloride in paste form.(16) this means that the material might act mechanically pushing the sulcus away due to the high consistency of the kaolin material (an aluminum-silicate-hydrate), which absorbs gcf and expands, similar to expasyl®(17) and by chemical means depending on aluminum chloride (15%) that was eased into the intra-crevicular space beneath the gingival margin by the fine application tip (1mm) and constricted the gingival tissues. the results of the present study agree with the results of prasanna et,al.,(2) who concluded that the mean width of the retraction paste (expasyl®) was greater than the mean width of the retraction cord. such agreement could be due to the similarity in size and type of the cord used (#00 knitted cord). on the other hand, the results of this study disagree with the results of kazemi et,al., and gupta et,al.,(6,8) who concluded that the mean width of the retraction cord was significantly greater than the mean width of the retraction paste (expasyl®). such disagreement could be due to the larger size of the cord used (#1), which might give better mechanical retraction than the thinner cord (#00) used in the present study. another possible cause is the difference in the type of medicament used to impregnate the cord (15% aluminum chloride) used by kazemiet et,al.,(6) and the difference in the composition of the cord used (softly braided retraction cord and ultra-fine copper filaments) used by gupta et,al.,(8) which might give better mechanical retraction than the knitted cord used in the present study. moreover, the finer applicator tip of astringent retraction paste used in the present study as compared with expasyl used by kazemi et,al., and gupta et,al.,(6, 8) might allow the material to be inserted deeper than expasyl. we recommend the use of astringent retraction paste and magic foam cord® since they provided better horizontal displacement of the gingival sulcus than medicated cords with the added advantages of simplified placement technique clinically shorter application time and astringent retraction paste provides better infection control because of its disposable hygienic unit dose capsules. on the other hand, we didn’t recommend the use of racegel alone for gingival retraction but only for hemostasis since it provides the least horizontal displacement of the gingival sulcus than other tested materials and its use might be necessary to be accompanied with retraction cords. references 1. shivasakthy m, ali sa. comparative study on the efficacy of gingival retraction using polyvinyl acetate strips and conventional retraction cordan in vivo study. j clin diag res 2013; 7(10): 1-4. 2. prasanna gs, reddy k, kumar rk, shivaprakash s. evaluation of efficacy of different gingival displacement materials on gingival sulcus width. j contemp dent pract 2013; 14(2): 217-21. 3. donovan te, chee ww. current concepts in gingival displacement. dent clin north am 2004; 48(2): 433-44. 4. mechanic e. gingival retraction using paste systems. oral health dent j 2013: 1-9. 5. coltène/whaledent. magic foam cord®. gingiva retraction without cords; 2011. 6. kazemi m, memarian m, loran v. comparing the effectiveness of two gingival retraction procedures on gingival recession and tissue displacement: clinical study. res j biol sci 2009; 4(3): 335-9. 7. phatale s, marawar pp, byakod g,lagdive sb, kalburge jv. effect of retraction materials on gingival health: a histopathological study. j indian soc periodontol 2010; 14(1): 35-9. 8. gupta a, prithvirai dr, gupta d, shruit dp. clinical evaluation of three new gingival retraction j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 31 systems: a research report. j indian prosthodont soc 2013; 13(1): 36-42. 9. powers jm and sakaguchi rl. craig’s restorative dental materials, 12th ed. st. louis: mosby inc.; 2006. p. 270-87. 10. bowles wh, tardy sj, vahadi a. evaluation of new gingival retraction agents. j dent res 1991; 70: 1447-9. 11. keith se, miller bh, woody rd, higginbottom fl. marginal discrepancy of screwretained and cemented metal-ceramic crowns on implants abutments. int j oral maxillofac implants 1999; 14: 369. 12. tan pl, gratton dg, diaz-arnold am, holmes dc. an in vitro comparison of vertical marginal gaps of cad/cam titanium and conventional cast restorations. j prosthodont 2008; 17: 378-83. 13. romeo e, iorio m, storelli s, camandona m, abati s. marginal adaptation of fullcoverage cad/cam restorations: in vitro study using a non-destructive method. minerva stomatologica 2009; 58: 61. 14. lin ct, lee sy, jen-chang y, may-show c, joanyvette w. cordless method of gingival sulcus management: clinical trial. iadr 2005: 3046. 15. fazekas a, csempesz f, csabai z, vag j. effects of pre-soaked retraction cords on the microcirculation of the human gingival margin. oper dent 2002; 27(4): 343-8. 16. bennani v, inger m, aarts jm. comparison of pressure generated by cordless gingival displacement materials. j prosthet dent 2014; 112(2): 163-7. 17. einarsdóttir er. temporary tissue retraction before taking impression: a multi-center randomized controlled clinical trial comparing the use of retraction cord, aluminum chloride paste (expasyl®) and combination of aluminum chloride paste and retraction cord, chapter one: introduction. a master thesis, faculty of odontology, university of iceland, 2012. bayan.doc j bagh college dentistry vol. 27(1), march 2015 in vivo histological oral diagnosis 100 in vivo histological evaluation of the effect of the topical application of estrogen hormone on wounds healing in ovariectomized rabbits bayan jaber al-kadhimy, b.d.s. (1) ban a. ghani, b.d.s., m.sc., ph.d. (2) abstract background: wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. growth factors released in the traumatized area promote cell migration into the wound area (chemotaxis), stimulate the growth of epithelial cells and fibroblasts (mitogenesis), initiate the formulation of new blood vessels (angiogenesis), and stimulate matrix formation and remodeling of the affected region. one of factors that effects on wound healing is a sex hormones and one of these hormones is an estrogen hormone. a wide range of cutaneous cell types (eg, fibroblast, endothelial, epithelial, and inflammatory) expressed estrogen receptors, indicating potential estrogen responsiveness. materials and methods: thirty two female new zealand rabbits were used in this study. all animals were ovariectomized, and incisional wounds were done on the right (experimental for estrogen hormone application) and left (control) sides of face for each animal, the control side was left to heal normally. histological assessment regarding the count of inflammatory cells was performed for healing intervals (3, 7, 10, 14 days). results: topical estrogen hormone application revealed enhancement of wound healing by reducing wound size and stimulating matrix deposition in comparison to control. conclusion: topical estrogen cream application results in significant progress of cutaneous wound healing, leaving no scar or crust formation and can minimize the probable wound complications. key words: estrogen hormone, wound healing. (j bagh coll dentistry 2015; 27(1):100-104). introduction skin is the biggest external defense system. skin covers the outside of the body but has other functions beside the defense mechanism. it serves as a mechanical barrier between the inner part of the body and the external world. it consists of three layers, the outer layer is called epidermis, the middle layer is dermis and the inner most layer is hypodermis (1). a wound is defined as a defect or break in the skin, resulting from physical or thermal damage or as a result of the presence of an underlying medical or physical condition (2). wound healing is a complex process consisting of four steps: haemostasis, inflammatory reaction, proliferation and remodeling, all of which are regulated by cytokines and growth factors released by cells in the wounded area. (3). estrogens are a class of hormones produced in the ovaries, or made from other hormones in fat cells. there are three estrogens: estradiol, estratiol and estrone. these natural hormones work more efficiently compared to synthetic estrogens or, even worse, animal estrogens. in the case of the skin the differential targeting of estrogen receptors to promote healing in aged subjects is a real therapeutic possibility (4). (1)master student. department of oral diagnosis, college of dentistry, university of baghdad. (2)assist. professor, department of oral diagnosis, college of dentistry, university of baghdad. estrogen, stimulate proliferation of keratinocytes and suppresses apoptosis and thus prevents epidermal atrophy. estrogen also enhances collagen synthesis, and estrogen and progesterone suppress collagenolysis by reducing matrix metalloproteinase (mmp) activity in fibroblasts, thereby maintaining skin thickness (5) with a reduction of steroid hormones following ovariectomy, alternatively activated macrophage markers were reduced (6) materials and methods materials: -estrogen cream (aldo-union) -anesthetic solution: ketamine hydrochloride (ketamin 50mg/ml){1 ml/kg body weight}; xylocain (10%,){1 ml/kg body weight}. zylazine (20mg/ml). -formalin 10%, ethanol alcohol 96%, xylol, paraffin wax. -hematoxylen and eosin (h&e). method thirty two female new zealand white rabbits age from 6-12 months were used as animal model in this study, their weights ranged between 1.5-2.5 kg .the experimental animals were divided into four groups, eight animals for each healing interval (3,7,10,14 days) all animals were subjected to ovariectomy operation, and all animals left about two weeks after doing j bagh college dentistry vol. 27(1), march 2015 in vivo histological oral diagnosis 101 ovariectomy operation. then animals in each group were operated as follows: a right facial skin was operated as experimental side . bleft facial skin was operated as control side. analysis of number of inflammatory cells it was performed by counting inflammatory cells, in histological sections (h&e stained), for each animal and in four microscopic fields at x40 magnification. scores for intensity of inflammatory reaction: 1 absent or very few inflammatory cells. 2 mild: average number less than 10 inflammatory cells 3 moderate: average number 10-25 inflammatory cells 4 severe: average number greater than 25 inflammatory cells (7) histological preparation all tissue specimens, samples and controls, were fixed in 10% neutral formalin and processed in a routine paraffin blocks. each formalin-fixed paraffin-embedded specimen had serial sections were prepared as follows: 5µm thickness sections were mounted on clean glass slides for routine haematoxylin and eosin staining (h&e), from each block of the studied sample (experimental and the control groups) for histopathological reexamination. results three days duration control group after three days of skin incision, the histological view of wound site of control group shows the defect area, no epithelium is formed yet and necrotic tissue is seen (figure1). figure 1: view of wound site of control group after 3days shows defect area with necrotic tissue. h&ex10. experimental group microphotograph view of skin of 3days duration at wound site of experimental group shows area of acute inflammation and epithelial cells migration also shows granulation tissue formation and hair follicles are formed (figure 2). figure 2:view at wound site of experimental group after 3days shows area of acute inflammation and epithelial cells migration (red arrow), cross section of epithelia(e) and granulation tissue (gt). h&ex20. seven days duration control group histological findings of wound site of control group of 7days duration, shows complete epithelialization, the subepidermal layer is congested with numerous blood cells and there is decreased number of inflammatory cells, together with deposition of loose collagen fibers (figure3). figure 3: microphotograph of control group, after 7days showing complete epithelialization (e), loose fibrous connective tissue and fibroblasts (fb) h&ex40. experimental group histological findings of experimental group of 7 days duration showed reduction in gt e e fb ct j bagh college dentistry vol. 27(1), march 2015 in vivo histological oral diagnosis 102 inflammatory cells and replacement of granulation tissue by fibrous connective tissue with scattered fibroblasts and complete epithelialization is seen too (figure4). figure 4: view of wound site of experimental group after 7days shows loose fibrous connective tissue (ct), scarce number of inflammatory cells (ic) (arrows) and thin newly formed epithelium. h & ex40. ten days duration control group histological section at wound site of ten days duration of control group shows reepithelialization with no rete-ridges, newly formed hair follicles and remoedeling of collagen fibers can be detected (figure5) figure 5: view at control wound site after10days illustrating thin newly formed epithelium (e), new hair follicles (hf) and remodelling fibrous connective tissue (ct). h&ex20 experimental group histological section at wound sit of experimental groups at 10 days duration shows that the new epithelium is comletely formed with no rete-ridges and number of fibroblasts with remodelling fiberous connective tissue (figure 6). figure 6: micophotograph at experimental wound site of 10 days duration shows numerous fibroblasts (fb) with maturing collagen fibers (cf) and the epidermis is fully formed. h&ex40. foutreen days duration control group histological section at wound site of 14days duration of control group shows fibrous connective tissue with few blood capillries also remodelling of collagen fibers which seem to be still matureing can be detected (figure 7) figure 7: view at control wound site of 14 days shows mature collagen fibers ( cf), fibroblasts (fb) and blood capillaries ( bv). h&ex20. experimental group view of skin section at wound site of experimental group at 14 days revealing complete epithelialization ,the new epithelium is thin with no rete-ridges and healed wound site with fibrous ct e e ct hf hf ep fb cf fb bv cf j bagh college dentistry vol. 27(1), march 2015 in vivo histological oral diagnosis 103 connective tissue with reduced cellular component can be detected (figure 8). figure 8: microphotograph at skin section of experimental group after 14 days shows complete epithelialization, dense fibrous connective tissue (ct) with reduced number of fibroblasts (fb) (arrows). h&ex40. the results of the present study have shown a higher count numbers of all estimated inflammatory cells for experimental group in 3 and 7 days than in control group, while a higher count was detected at 10 and14 days for control group than experimental group, and the highest mean values were recorded at the 3 and 7 days for both experimental and control groups. table 1: distribution of the observed frequencies and percentages of the inflammatory cells in different periods periods score control ms sd exp. ms sd p valueno % no % 3 days 1 0 0 2.87 0.64 0 0 3.87 0.35 0.022 2 2 25 0 0 3 5 62.5 1 12.5 4 1 12.5 7 87.5 7 days 1 0 0 2.75 0.46 0 0 3 0.53 0.332 2 2 25 1 12.5 3 6 75 6 75 4 0 0 1 12.5 10 days 1 0 0 2.37 0.51 0 0 2.12 0.35 0.264 2 5 62.5 7 87.5 3 3 37.5 1 12.5 4 0 0 0 0 14 days 1 0 0 2.12 0.35 6 75 1.25 0.46 0.022 2 7 87.5 2 25 3 1 12.5 0 0 4 0 0 0 0 figure 9: cluster bar chart of inflammatory cells parameter's means of score values in different periods. discussion skin healing involves cross-reactions between cells from the epidermis and dermis, with the participation of cytokines, growth factors and modulation of the extracellular matrix. this occurs in three stages: 1) inflammatory reaction; b) formation of granulation tissue; and c) remodeling of the granulation tissue (8). the result of present study showed the defect area, no epithelium is formed and necrotic tissue at three days of skin incision in control grou p (9). in experimental group at3 days, histological observation showed area of granulation tissue formation, epithelial cells migration, new hair follicles were formed, numerous blood capillaries and numerous inflammatory cells (10) . in control group at 7 days of incisional wound histostological evaluation revealed complete epithelialization (11). in experimental group at 7 days of incisional wound, the histological results showed reduction in inflammatory cell count and replacement of granulation tissue by fibrous connective tissue (11). at 10 days of incisional wound, there is similar characteristic feature between experimental and control group and this period detected by newly formed epithelium, active fibroblast with remodeling of collagen fibers and granulation tissue (12). in the present study, the histological observation of skin wound at 14 days for control and experimental groups showed complete epithelialization, complete healing and reduce cellular inflammatory response (13). the result of the present study show that there was a marked increase in the number of inflammatory cells that infiltrated into the wound e ct fb fb j bagh college dentistry vol. 27(1), march 2015 in vivo histological oral diagnosis 104 sites in the experimental group during period of 3 and 7 days as a compare with control group, while a higher count was detected at 10 and14 days for control group than experimental group (14). the highest mean values were recorded at 3 and 7 days for both experimental and control groups (15). in conclusion; topical estrogen is a step in the direction of increasing the extent of wound healing by reducing wound size and stimulating matrix deposition, and estrogen administration results in significant progress of cutaneous wound healing, leaving no scar or crust formation. histological findings revealed that estrogen treated wounds exhibited good reepithelialization and granulation tissue organization. finally estrogen is the most important hormone to regulate skin hemostasis, increase collagen content and dermal thickness. references 1. sherwood l. human physiology: from cells to systems. 6th ed. stamford: thomson brooks; 2007. 2. boateng js, matthews kh stevens hne and eccleston gm. wound healing dressings and drug delivery systems: a review. j pharmaceutical sci 2008; 97: 2892-923. 3. al-watter wm, abdulluh bh, mahmmod as. irradiation of 780-805nm diode laser on wound healing in mice. j bagh coll dentistry 2013; 25(sp iss 1): 48-52. 4. emmerson e, hardman mj. the role of estrogen deficiency in skin ageing and wound healing. biogerontol 2011; 13(1): 3-20. 5. kanda n, shinichi watanabe s. regulatory roles of sex hormones in cutaneous biology and immunology. j dermatol sci 2005; 38(1):1-7. 6. routley ce, ashcroft gs. effect of estrogen and progesterone on macrophage activation during wound healing. wound repair regen 2009; 17(1): 42-50. 7. accorinte m, holland r, reis a, bortoluzzi m, murates s. union of mineral trioxide cement as pulp capping agent in teeth. j endod 2008; 34:1-6 8. werner s, grose r. regulation of wound healing by growth factors and cytokines. physiol rev 2003; 83(3): 835-70. 9. kashmoola ma. histopathological evaluation of skin wound in rabbits treated by systemic dexamethasone. j bagh coll dentistry 2007; 19(1): 58-61. 10. gal p, vidinsky b, toporcer t. histological assessment of the effect of laser irradiation on skin wound healing in rats. photomed las surg 2006; 24(4):480-8. 11. al-wattar wm. immunohistochemical evaluation of the effect of 790-805nm diode laser on interlukin-1β, epidermal, fibroblast, vascular endothelial and platelet derived growth factors in wound healing. ph.d. thesis, department of oral diagnosis, college of dentistry, baghdad university, 2013. 12. braiman-wiksman l, solomonik i, spira r and tennenbaum tn. novel in sight into wound healing sequence of events. toxical pathol 2007; 35(6):76779. 13. gall p, kilik r, mokry m, vidinsky b, vasilenko t, mozes s, bobrov n, tomori z, bober j and lenhardt l. simple method of open skin wound healing model in corticosteroid-treated and diabetic rats: standardization of semi-quantitative and quantitative histological assessments. veterinarni medicina 2008; 53(12): 652–9. 14. rajabi ma, rajabi f. the effect of estrogen on wound healing in rats. pak j med sci 2007; 23: 3. 15. abdul-karem zb. clinical & histopathological study of the effect of magnetic field on the healing of open wounds in rabbits. a master thesis. basrah university, 2009. الخالصھ .وقف النزف وااللتھاب والتكاثر واعادة البناء: مراحل مبرمجة بدقة عالیة التئام الجروح یعتبر عملیة بیولوجیة طبیعیة في جسم االنسان ویتحقق من خالل اربع :المقدمھ تكّون أو نمو االنقسام (وتحفز نمو الخالیا الظھاریة والخالیا اللیفیة ) الكیمیائي االنجذاب(ھناك عوامل نمو تتحرر في المنطقة المصابة لتعزز وتشجع انتقال الخالیا الى منطقة الجرح وأحد العوامل التي تؤثر. وتحفز تكوین القالب األم واعدة بناء المنطقة المتضررة) تّكون االوعیة والعروق(وكذلك تبدأ بتكوین أوعیة دمویة جدیدة ) الخیطي مثل الخالیا اللیفیة والبطانیة والظھاریة معدل واسع من انواع الخالیا الجلدیھ . سیة و واحد من ھذه الھرمونات ھو ھرمون اإلستروجینعلى شفاء الجروح ھو الھرمونات الجن .مما یدل على استجابة ھرمون اإلستروجین المحتملة, واإللتھابیة تعتبر كمستقبالت لإلستروجین الجانب التجریبي (تم عمل الجروح الجراحیة على الجانب األیمن, كل الحیوانات كانت مستأصلة المبیض استخدمت اثنین وثالثین لألناث ارانب نیوزیلندا في ھذه الدراسة :المواد والعمل الخالیا االلتھابیة نسبھ الى معدل التقییم النسیجي .بشكل طبیعي للشفاء تحكموترك جانب ال, من وجھ كل حیوان )جانب التحكم(للتطبیق الموضعي لھرمون االستروجین والجانب االیسر ).یوم14,10,7,3(كان أنجز للفترات الشفاء الفاصل . القالب االم مقارنھ مع مجموعھ التحكماضھر التطبیق الموضعي لكریم االستروجین تعزیز شفاء الجروح عن طریق تقلیل حجم الجرح وتحفیز ترسب :النتائج الجروح اظھر االستعمال الموضعي لكریم االستروجین تقدم ملحوظ على شفاء الجروح حیث الیترك اثر او تكوین ندبھ ویمكن ان یقلل مشاكل مضاعفات: جاالستنتا .عالمات الجلد الكیمیائیھ, شفاء الجروح , ھرمون االستروجین :الكلمات المفتاحیھ osama f.doc j bagh college dentistry vol. 27(3), september 2015 immunohistochemical oral diagnosis 64 immunohistochemical expression of cyclin d1 in mucoepidermoid and adenoid cystic carcinoma of the salivary glands osama mohammed ghazi, b.d.s. (1) lehadh m. al-azzawi, b.d.s., m.sc., ph.d. (2) wisam abdul lateef hussein, m.b.ch.b., f.i.c.m.s. (3) abstract background: cyclin d1 proto-oncogene is an important regulator of (g1 to s) phase progression in many different cell types. the aims of this study were to evaluate the immunohistochemical expression of cyclin d1 in mucoepidermoid and adenoid cystic carcinoma of the salivary glands and to correlate the immunoexpression of this protein with the clinicopathological findings. materials and methods retrospectively, twelve of archival formalin fixed paraffin embedded tissue samples of salivary mucoepidermoid and fourteen blocks of adenoid cystic carcinomas obtained from the archives of the department of oral pathology / college of dentistry / baghdad university, al-shaheed ghazi hospital, were included in this study. five micrometer sections obtained and immunostained using monoclonal antibody against cyclin d1. the immunoexpression was detected by the presence of brown stain in the nucleus of tumor cell. the proportion of cells that expressed the stain was correlated with the clinicopathological data of the patients. results: cyclin d1 expression was found positive in all cases of mec and adcc localized in tumor cells. nonsignificant statistical relation (p=0.588) was detected regarding cyclin d1 expression in both types of tumor. significant relation was found with stage of adcc (p=0.04) and non-significant concerning other clinicopathological parameters in both tumor types. conclusion: weak expression of cyclin d1 in mec and adcc might be explained by cyclin d1 does not represent an exclusive factor consequently; other factors might be involved in the proliferation, progression and metastasis of both tumor types. key words: mucoepidermoid carcinoma, cyclin d1, immunohistochemistry, adenoid cystic carcinoma. (j bagh coll dentistry 2015; 27(3):64-69). introduction salivary gland carcinomas constitute about 1 to 3% of all head and neck malignancies and 0.3% of all cancers (1). the mucoepidermoid carcinoma (mec) is a malignant epithelial neoplasm composed of varying proportion of mucous, epidermoid, intermediate, columnar, and clear cells and often demonstrates prominent cystic growth (2). it is one of the most common salivary gland malignancies with varying degree of gressiveness (3). the annual incidence of mec is 0.44 per 100,000 persons. it accounts for 12% to 29% of malignant salivary gland tumors (4). mec mostly occurs from the second to seventh decades of life and has a slight predilection for women (60%) (5,6). approximately one half of these tumors (53%–56%) arise in the major salivary glands, with 85% to 88% occurring in the parotid gland. the minor glands constitute the second most common site after parotid, especially the palate (7). central mec of the jaw is rare (4% of all mecs), most often located in the mandible (3). (1)m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2)assist. professor, department of oral diagnosis, college of dentistry, university of baghdad. (3)pathologist. al-shaheed ghazi hospital/ baghdad medical city the adenoid cystic carcinoma (adcc) is one of the more common and best-recognized salivary gland malignancies with a deceptively benign histologic appearance characterized by indolent, locally invasive growth with high propensity for local recurrence and distant metastasis (8). adcc arise from malignant transformation of the intercalated duct reverse cells and it’s a malignant tumor of modified myoepithelial and ductal cells that form characteristic cribriform, tubular, and solid growth patterns and has a predilection for perineural invasion (2,5). adcc accounts for 1% of all malignant tumors of the oral and maxillofacial region and 23% of all salivary malignancies (9,10). most cases are diagnosed from the fifth to seventh decades of life and the female­to­male ratio is around 3:2. approximately 50% to 70% of all reported cases of adcc carcinoma occur in minor salivary glands of the head and neck, chiefly of the palate (5,6). cyclin d1 is a founding member of cyclins which are group of proteins so called because of the cyclic nature of their production and degradation. they form complexes with cyclin dependent kinases (cdks); such complexes phosphorylate crucial target proteins that drive the cell through the cell cycle (11). it is 45 kda protein that in human is encoded by the ccnd1 gene j bagh college dentistry vol. 27(3), september 2015 immunohistochemical oral diagnosis 65 located on chromosome 11q13. this is today considered a well-established human oncogene (12). the cyclin d1 proto-oncogene is an important regulator of (g1 to s) phase progression in many different cell types. together with its binding partners cyclin dependent kinase 4 and 6 (cdk4 and cdk6), cyclin d1 form active complexes that promote cell cycle progression by phosphorylating and inactivating the retinoblastoma protein (rb) (13). overexpression of cyclin d1 is known to correlate with the early onset of cancer and risk of tumor progression and metastasis14. however, a number of studies have shown a surprising lack of correlation between increased cyclin d1 expression and increased dna synthesis in tumors (15). chromosomal translocations, gene amplification and disruption of normal intercellular trafficking and proteolysis are the procedures which lead to accumulation of cyclin d1 in tumor cell nuclei and eventually to cyclin d1 overexpression in many tumors (16). cyclin d1 amplification and/or overexpression have been demonstrated in a variety of human tumors, including mantle cell lymphoma, breast carcinoma, head and neck squamous cell carcinomas, and esophageal cancers. among lymphoid neoplasms a subset of chronic lymphocytic leukemia, small lymphocytic lymphoma, and multiple myeloma have been reported to express cyclin d1 (17). materials and methods patients twenty six patients with salivary gland malignancies was randomly selected from the file records and pathologic specimens from the maxillofacial center in al-shaheed ghazi hospital in baghdad, from the year 2009 through 2013, and from the archives of the department of oral diagnosis/ collage of dentistry/baghdad university dated from 1972 to 2011. demographic and clinical data provided by the surgeon were collected from the case sheets presented with the tumor specimens, including patient's information concerning age, sex, site and clinical staging of the tumor were recorded, and staging was carried out according to (uicc) international union against cancer tnm classification of malignant tumors usa 2002. all clinical and histopathologic data available were analyzed to exclude cases representing secondary metastatic disease to the salivary gland or to intraparotid lymph nodes. control five normal salivary gland tissues were used as negative external controls. at the same time by omitting of primary antibody step and addition of all other reagents were used also as negative control. positive staining indicates a lack of specificity of the antibody and breast carcinomas were used as positive control for cyclin d1 according to ab cam manufacturer’s data sheets. immunohistochemistry sections of 5µm were de-paraffinized in xylene and rehydrated in graded alcohol. enough drops of hydrogen peroxide block were added to slides and incubated in humid chamber at 37c° for 10 minutes, and then socked 2 times in buffer (5 minutes for each). then tissue retrieving is done to the slides in order to uncover antigenicity because formalin or other aldehyde fixation forms protein cross-links that mask antigenic sites in tissue specimens. after that enough drops of protein block were added to slides and incubated at 37°c for 10 minutes. then washed 2 times in buffer (5 minutes for each), finally drained and blotted gently. then diluted primary antibody was applied to each slide, incubated in humid chamber at 37°c. overnight. early in the next day, the slides were washed in buffer (4 times for each), finally drained and blotted gently as before. next enough drops of secondary antibody reagent were added and incubated in humid chamber for 30 minutes at 37°c. after that, the slides were washed 4 times in buffer (5 minutes for each), finally drained and blotted gently. then streptavidine-hrp antibodies were applied on tissue and incubated for 30 minutes at 37°c. later diluted dab was applied on tissue (this process was done in dark room) and incubated in humid chamber for 10 minutes at 37°c. then slides washed carefully in tap water for 5 minutes. after that the slides were bathed in hematoxylin counter stain for 1-2 minutes then they were rinsed with tap water for 10 minutes. later the slides were dehydrated by immersing them in ethanol and xylene containing jars then one to two drops of dpx mounting medium were applied to the xylene wet sections and covered with cover slips and left to dry overnight. then the results were evaluated by the presence of brown colored end product at the site of target antigen (nucleus) was indicative of positive immunoreactivity. percentage of ihc positive tumor cells per hotspot was calculated and the mean percentage per slide was determined. the intensity of stain was ignored because it’s subjected to individual difference during checking. the immunoreactivity of cyclin d1 was classified as follows: (score 0) (-ve) 0% of the tumor cells, focal (score i) (+) 1-25%, moderate (score ii) (++) 26-50%, diffuse (score j bagh college dentistry vol. 27(3), september 2015 immunohistochemical oral diagnosis 66 iii) (+++) 51-75% of positive cells, depending on counting, very diffuse (score iv) (++++) 76-100% (18). statistical analysis all the clinical, histopathological and immunohistochemical relevant data so obtained was tabulated and subjected to appropriate statistical analysis using the spss 17 statistical software. the studied parameters were scored and considered as categorical data and presented as count and percentage. chi-square test used to test the relationship between categories. anova test (analysis of variance) was used to detect differences for age and the marker. p value equal or less than 0.05 was considered to be statistically significant. results cyclin d1 immunoexpression cyclin d1 immunoreactivity was noticed as brown staining localized in the nucleus of tumor cells. cyclin d1 expression was found positive in all cases of mec and adcc in different scores (figures 1, 2, 3, 4 and 5). the higher percentage of cyclin d1 expression (score i) was found in 7 cases of mec (58.3%) and in 8 cases of adcc (57.1%). table 1: cyclin d1 scores in mec and adcc cyclin d1 score mec adcc score i 7(58.3%) 8(57.1%) score ii 4(33.3%) 3(21.4%) score iii 1(8.3%) 3(21.4%) total 12 (100%) 14 (100%) p value=0.588 ns non-significant statistical relation (p=0.588) was detected regarding cyclin d1 expression in both types of tumor (table 1).non-significant statistical relations were found concerning cyclin d1 expression with age groups (p=0.44), gender (p=0.193), anatomical site (p=0.36), grade, and stage (p=0.207) in mec as in tables 2, 3, 4, 5 and 6. table 2: cyclin d1 scores in relation to age groups in mec cyclin d1 scores no. mean min max ns score i 7 48.42 13 62 score ii 4 43 22 60 score iii 1 25 table 3: cyclin d1 scores in relation to gender in mec table 4: cyclin d1 scores in relation to the anatomical site in mec sites cyclin d1 scores total score i score ii score iii major glands 5 2 0 7 minor glands 2 2 1 5 total 7 4 1 12 test chi square test=2; p=0.36ns table 5: cyclin d1 scores in relation to the stage in mec cyclin d1 score mec stage i ii iv total score i 1 3 3 7 score ii 3 1 0 4 score iii 1 0 0 1 total 5 4 3 12 test chi square= 5.893; p value= 0.207 ns table 6: cyclin d1 scores in relation to the stage in mec cyclin d1 score mec auclair grading system i ii iii total score i 3 1 0 4 score ii 3 1 2 6 score iii 1 0 1 2 total 7 2 3 12 test chi square= 5.893; p value= 0.207 ns for adcc statistically non-significant relations were observed concerning age (p=0.1), sex (p=0.646), site (p=0.36), and grade of tumor (p=0.533). whereas significant relation was found with stage of tumor (p=0.04) as in tables 7, 8, 9 and 10. table 7: cyclin d1 scores in relation to gender in adcc adcc sex total cyclin d1 scores m f i no. 2 6 8 ii no. 1 2 3 iii no. 2 1 3 total no. 5 9 15 mec cyclin d1 scores sex total m f i no. 5 2 7 ii no. 1 3 4 iii no. 0 1 1 total no. 6 6 12 j bagh college dentistry vol. 27(3), september 2015 immunohistochemical oral diagnosis 67 table 8: cyclin d1 scores in relation to the anatomical site in adcc sites cyclin d1 scores total score i score ii score iii major glands 3 0 1 4 minor glands 5 3 2 10 total 8 3 3 14 test chi square test=2; p=0.36ns figure 1: cyclin d1 positive expression in low grade mec table 9: cyclin d1 scores in relation to the grade in adcc cyclin d1 score adcc grade i ii iii total score i 2 5 1 8 score ii 0 3 1 4 score iii 0 2 0 2 total 2 10 2 14 test chi square= 5.893; p value= 0.533 ns table 10: cyclin d1 scores in relation to the stage in adcc cyclin d1 score adcc stage i ii iii iv total score i 1 3 4 0 8 score ii 1 1 0 1 3 score iii 0 0 0 3 3 total 2 4 4 4 14 test x2= 12.979; p value=0.043 s (p<0.05) figure 2: cyclin d1 expression in intermediate grade mec figure 3: cyclin d1 expression in high grade mec figure 5: strong positive immunostaining of cyclin d1 in adcc figure 4: cyclin d1 expression in adcc j bagh college dentistry vol. 27(3), september 2015 immunohistochemical oral diagnosis 68 discussion cyclin d1 is the first cyclin that accumulates after mitogenic signaling. cyclin d1 binds to cdk4 or cdk6, forming a complex that binds to the prb protein, phosphorylating and inactivating it and leading to the release of transcription factor e2f, thus initiating cell proliferation through the g1 phase (19). the cyclin-cdk complex controls cell cycle progression by means of ordered activation and inactivation. any disturbance in this mechanism may play an important role in the pathogenesis of various malignant tumors. some studies indicate that overexpression of cyclin d1 occurs at the beginning of tumor development and might therefore be considered an early marker of cell proliferation, whereas others have demonstrated late overexpression of this protein during the development of malignant tumors (20). the levels of d-cyclins are controlled by the extracellular environment. it is therefore considered that d-cyclins present a link between extracellular mitogenic stimulation and core cell cycle machinery (21). in this study all cases of mec and adcc showed immunoreactivity for cyclin d1 with variable scores. the immunostaining was limited to the epidermoid cells of the mec and luminal and abluminal cells of the adcc. the majority of the cases were (score i) immunostaining (57.6%). these findings were in agreement with another studies conducted by jour and his colleagues (18) and with another findings by zhou et al. (22) and disagreed with another studies (23-25) whose detected the expression of cyclin d1 in adcc and observed overexpression in 4 of 22 cases, 3 of them showing the solid pattern, which have the worst prognosis. one study in 2006 showed that cyclin d1 overexpression was present in 90% (35/39) of adcc evaluated cases (26). focal expression of cyclin d1 in mec and adcc might be explained by cyclin d1 does not represent an exclusive factor consequently; other factors might be involved in the proliferation, progression and metastasis of both tumor types. at least nine classes of cyclins and seven cdk catalytic subunits have been identified in mammalian cells, two cdk subunits (cdk4 and cdk6) in combination with three d-type cyclins (d1, d2 and d3), and cdk2 in combination with cyclin e, are involved in g1/s progression and regulation and the kinase activity is inhibited by a number of specific proteins belonging to the ink4 and cip/kip families (p21, p27, p57) (27). teruyo and hiroki (28) showed that cells over-expressing cyclin d1 exhibited significantly increased invasiveness and the cyclin d1 expression was associated with the increased gelatinolytic activity with the activation of prommp-9 to the intermediate form of mmp-9. they concluded that cyclin d1 may modulate invasive ability by increasing mmp activity and cell motility and this explain significant relation of cyclin d1 expression with the stage in adcc (28). as conclusion; cyclin d1 immunoexpression was detected in all cases of studied samples with variable scores. weak expression of cyclin d1 in mec and adcc might be explained by cyclin d1 does not represent an exclusive factor consequently; other factors might be involved in the proliferation, progression and metastasis of both tumor types. references 1. spitz mr, batsakis jg. major salivary gland carcinomas: descriptive epidemiology and survival of 498 patients. arch otolaryngol 1984; 110: 45-9. 2. weidner n, cote r, suster s, weiss l. modern surgical pathology. 3rd ed. saunders co.; 2009. p.24694. 3. neville bw, douglas d, carl m, jeery e. oral and maxillofacial pathology. 3rd ed. saunders co.; 2009. p.453-506 4. speight pm, barrett aw. salivary gland tumors. oral dis 2002; 8(5): 229-40. 5. regezi ja, scibubba jj, jordan k. oral pathology, clinical pathologic correlation. 6th ed. saunders co.; 2012. p. 186-225. 6. gnepp d. diagnostic surgical pathology of the head and neck. 2nd ed. saunders; 2009. p. 434-530. 7. ellis gl, auclair pl. malignant epithelial neoplasms. in ellis gl, auclair pl (eds). atlas of tumor pathology. tumors of the salivary glands. washington, dc: armed forces institute of pathology; 1996. p. 337–343 8. jaso j, malhorta r. adenoid cystic carcinoma. arch pathol lab med 2011; 135: 511-5. 9. kokemueller h, eckardt a, brachvogel p, hausamen j. adenoid cystic carcinoma of the head and neck: a 20 years’ experience. int j oral maxillofac surg 2004; 33(1): 25-31 10. dodd rl, slevin nj. salivary gland adenoid cystic carcinoma: a review of chemotherapy and molecular therapies. oral oncol 2006; 42(8):759-69. 11. kumar v, abbas k, fusto n, mitchell r. basic pathology; acute and chronic inflammation. 8th ed. saunders; 2007. p. 47-48. 12. musgrove ea, caldon ce, barraclough j, stone a, sutherland rl. cyclin d as a therapeutic target in cancer. nat rev cancer 2011; 11: 558-72. 13. kato j, matsushime h, hibebert w, ewen e, sherr j. direct binding of cyclin d to the retinoplastoma gene product (prb) and prb phosphorylation by the cyclin d dependent kinase cdk4. gene dev 1993; 7(3): 331-42. 14. wang c, li z, fu m, et al. signal transduction mediated by cyclin d1: from mitogens to cell proliferation: a molecular target with therapeutic potential. cancer treat res; 2004; 119: 217-37. 15. shoker bs, jarvis c, davies mp, iqbal m, sibson dr, sloane jp. immunodetectable cyclin d1 is associated with estrogen receptor but not ki-67 in normal, j bagh college dentistry vol. 27(3), september 2015 immunohistochemical oral diagnosis 69 cancerous and precancerous breast lesions. brj cancer 2001; 84:1064-9. 16. abid am, merza ms. immunohistochemical expression of cyclin d1 and nf-kb p65 in oral lichen planus and oral squamous cell carcinoma (comparative study). j bagh coll dentistry 2014; 26(1): 80-7. 17. donnellan r, chetty r. cyclin d1 and human neoplasia. j clin pathol mol pathol 1998; 51:1-7. 18. jour g, west k, ghali v, shank d, ephrem g, weing b. differential expression of p16 ink4a and cyclin d1 in benign and malignant salivary gland tumors: a study of 44 cases. head and neck pathol 2013; 7(3): 224-31. 19. haas s, hormann k, bosch fx. expression of cell cycle proteins in head and neck cancer correlates with tumor site rather than tobacco use. oral oncol 2002; 38: 618-23. (ivsl) 20. si x, liu z. expression and significance of cell cyclerelated proteins cyclin d1, cdk4, p27, e2f-1 and ets-1 in chondrosarcoma of the jaws. oral oncol 2001; 37:431-6. 21. shoker bs, jarvis c, davies mp, iqbal m, sibson dr, sloane jp. immunodetectable cyclin d1 is associated with estrogen receptor but not ki-67 in normal, cancerous and precancerous breast lesions. brj cancer 2001; 84:1064-9. 22. chuan-xiang zhou, yan gao. aberrant expression of β-catenin, pin1 and cyclin d1 in salivary adenoid cystic carcinoma: relation to tumor proliferation and metastasis. oncology 2006; 16: 505-11. 23. ryujii y, kuratomi y, nakashima t, masuda m, yamamoto t. cyclin d1 expression does not affect cell proliferation in adenoid cystic carcinoma of the salivary gland. oto-rhino-laryngol 2004; 261(10):526-530. 24. seethala rr, hunt jl, baloch zw, livolsi va, barnes el. adenoid cystic carcinoma with high grade transformation: a report of 11 cases and review of the literature. am j surg pathol 2007; 31(11):168394. 25. shintani s, mihara m, nakahara y, kiyota a, yoshihama y, ueyama y, matsumura t. infrequent alternations of rb pathway (rb-p16ink4a-cyclind1) in adenoid cystic carcinoma of salivary glands. anticancer res 2000; 20: 2169-75. 26. greer ro jr., said s, shroyer kr, marileila vg, weed sa. overexpression of cyclin d1 and cortactin is primarily independent of gene amplification in salivary gland adenoid cystic carcinoma. oral oncol 2007; 43(8): 735–41. (ivsl) 27. pignataro l, sambataro g, pagan di, pruneri1g. clinico-prognostic value of d-type cyclins and p27 in laryngeal cancer patients. acta otorhinolaryngol ital 2005; 25(2): 75–85. 28. teruyo o, hiroki s. over-expression of cyclin d1 induces glioma invasion by increasing mmp activity and cell motility. j cancer 1999; 83: 387–92. j bagh college dentistry vol. 29(4), december 2017 effect of platelet oral and maxillofacial surgery and periodontics 58 effect of platelet-rich fibrin on implant stability amjed fouad hussien b.d.s (1) ali hussien al-hussaini b.d.s, m.sc. (2) abstract background: preparation of platelet-rich fibrin (prf) is a simple, low cost and minimally invasive method to obtain a natural concentration of autologous growth factors that is widely used to accelerate soft and hard tissue healing, thus, prf is used in different fields of medicine. the aim of this study was to evaluate the effect of local application prf on stability of dental implants. materials and methods: nineteen healthy patients with adequate alveolar bone with two or more adjacent missing teeth and/or bilaterally symmetric to the midline (split-mouth design) missing teeth participated in this study. each patient received at least two dental implants (dentium co., korea). after surgical preparation of the implant sockets, the prf was applied randomly into one of the implant socket before the placement of implant fixture )study group), while the second implant was inserted without prf (control group). the implant stability was measured by resonance frequency analysis (rfa) using osstelltm isq, at the time of surgery (primary stability), and at 4, 8 and 12 weeks postoperatively (secondary stability). results: although in the three records of secondary stability, the mean implant stability quotient (isq) in the study group was higher compared to the control group, this elevation was statistically not significant (p value > 0.05). on the other hand, prf showed a significant effect on implants stability by 2.367 folds for implants that achieved primary stability ≥ 70 and maintained this stability after 12 weeks. conclusions: within the limitations of this study, local application of prf exhibited that there was no statistical beneficial effect on implant stability. no significant correlation was found between local bone density and implant stability in both groups. key words: platelet-rich fibrin, stability, dental implant, resonance frequency analysis.(j bagh coll dentistry 2017; 29(4): 58-64) introduction the worthy of modern dentistry is to reestablish the patient’s facial contour, masticatory, speech, esthetic and function after tooth or teeth extraction. many methods were used for the replacement of missing tooth/teeth with natural or synthetic substitutes since centuries, however all these restorations take the support from the adjacent teeth and many problems occurred due to these replacement methods. the recent modality for the replacement of missing teeth is dental implants. endosseous dental implant is like the natural tooth root that restores the missing teeth without the need for the adjacent teeth for support and the basic advantage of implants is to preserve the alveolar bone like the healthy tooth(1). extensive work by brånemark who discovered that commercially pure titanium when placed in a suitably prepared site in the bone could become fixed in place due to close bond between the two. a phenomenon that later described as osseointegration, from that time many researches were done to influence the osseointegration process by studying the implant design, host site, surgical technique and loading time. in addition, many materials inserted in the prepared sites immediately before the insertion of the dental implants in order to enhance and reduce the time of osseointegration(1). (1) master student, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. recently applications of platelet-rich products; platelet rich in growth factor (prgf), platelet rich plasma (prp) and the platelet rich fibrin (prf) have been proposed as an aid to enhance regeneration of osseous and epithelial tissues in oral surgery(2). studies showed that the application of these materials on titanium implants enhance the bone-implant contact (bic) and hastening the osseointegration(2,3). platelet rich fibrin is a second-generation platelet concentrate, developed in france by choukroun et al. in 2000 and defined as an autologous leukocyte and platelet-rich fibrin biomaterial. it represents a new step in the platelet gel therapeutic concept, which attempts to accumulate leukocytes, platelets and released cytokines in a fibrin clot, which is widely used to accelerate soft and hard tissue healing(4). unlike other platelet concentrate, the prf preparation is simple protocol made by centrifugation of natural blood without additives(5). formation of a fibrin scaffold is the first step in peri-implant bone healing. platelets stick to this fibrin and are activated over the implant surface. activated platelets release many growth factors locally as; bone morphogenetic proteins (bmp), platelet-derived growth factor (pdgf), insulin like growth factor (igf), vascular endothelial growth factor (vegf), transforming growth factor-β1and β2 (tgf-β1,and tgf-β2), that accelerate the healing process by attracting undifferentiated mesenchymal cells to the injured site(6) . j bagh college dentistry vol. 29(4), december 2017 effect of platelet oral and maxillofacial surgery and periodontics 59 in an animal study, it was observed that more rapid healing process and bone formation observed in implants placed with prf than in the control implant, as proved by histological examination, in addition, immunohistochemical findings revealed a high positive expression for igf and pdgf in implants placed with prf in comparison to control one(7). recently in a clinical study done by öncü & alaaddinoglu in 2015 they observed that prf application appeared to increase implant stability during the early healing period, as evidenced by higher implant stability quotient (isq) values and they stated that simple application of this material seems to provide faster osseointegration(3). the hypothesis of this study based on the ability of local application of prf to improve implant stability. materials and methods nineteen patients; 12 females and 7 males with age range of 28-66 years initially participated in this prospective clinical study, at the dental implant clinic at the department of oral and maxillofacial surgery/college of dentistry/ baghdad university, during the period from december 2015 to july 2016. they received 58 implants divided into; 29 implants for each group (control and study group), each patient received at least two dental implant fixtures at the same session in the same edentulous region or bilaterally symmetric to the midline (split-mouth design), with the same or nearly the same diameter and length of implant fixtures. the prf was applied to one of the implant socket immediately before the placement of implant fixture to serve as a “study group” and the second fixture placed in the implant socket without prf, to serve as a “control group”. the patients who were enrolled to this study fulfilled the inclusion and exclusion criteria and screened for fitness to participate in the existing clinical trial. the inclusion criteria were as follow: patients ag ≥ 18 and > 70years, healed edentulous area for at least 6 months after extraction, the edentulous alveolar ridge span should receive at least two or more adjacent implants on one side or bilaterally symmetric to the midline of the same jaw and the implant sites should have a suitable height and width to avoid dehiscence and fenestration. exclusion criteria were; insufficient bone volume, parafunctional habits, smoking more than 10 cigarettes per day, excessive consumption of alcohol, localized radiotherapy, tumor and metastatic disease, chemotherapy, current corticosteroid or bisphosphonate use, pregnancy, and poor oral hygiene. the patients were informed about the study timetable in detail, and a written informed consent was obtained. prf preparation: platelet rich-fibrin preparation started with minimally invasive venipuncture technique using 21-gauge needle. the preferred vein chosen for venipuncture is the larger and fuller median cubital vein in the antecubital fossa. blood samples were collected in 10-ml plain blood collecting tube (afco, jordan) and immediately centrifuged at 3000 rpm for 12 minutes. approximately five-milliliter of the collected blood was used as a standardized amount for each study osteotomy site to get prf clots each have the same size and features in case of multiple study fixtures fig (1). figure (1): identical prf clot obtained from 10ml of blood (5 ml for each tube). the fibrin clot that was formed in the middle part of the tube was picked up and the remnants of red blood cells milked off with tweezer. the fibrin clot was placed on clean gauze that have been wetted with normal saline and compressed gently to be ready for installing in the prepared implant site fig (2). figure (2): prf clot after compression. j bagh college dentistry vol. 29(4), december 2017 effect of platelet oral and maxillofacial surgery and periodontics 60 stage one surgery (implant placement): the surgery started by anesthetizing the area with local infiltration technique (septodent, france), then crestal incision preformed slightly lingualy or palately to the crest of the ridge and an extensive three-sided mucoperiosteal flap performed and reflected. after exposing the implant site, the implant osteotomy was prepared according to recommendations of (dentium, korea) implant system. in addition, the resistance of bone to drilling through the preparation of the implants holes was categorized and documented as a bone type for each drilling site by the same surgeon according to lekholm and zarb classification, (1985)(8). the osteotomy sites were thoroughly irrigated with normal saline before the placement dental implants, prf clot gently introduced into one site (study implant site) and the other site left without prf (control implant site) and the implants placed at a level with or just below the crestal bone level fig (3). after the implants placement, primary implant stability for both implants (study and control implants) was measured by osstelltm isq and two readings of the isq values were recorded; in a bucco-lingual and in mesio-distal directions. the mean value of the two isq measurements was used. figure (3): application of prf clots at site no.13. postoperatively, patients were advised to apply cold pack extraorally for 8 hours. the patients medicated with; antibiotic (amoxicillin capsule 500mg three times daily or azithromycin tab 500mg one time daily for allergic patient and metronidazole tablet 500mg three times daily), analgesic (paracetamol tablet 500 mg as required) and antiseptic oral rinse (0.12% chlorhexidine gluconate) three times per day for a week, and the suture removed after 10 days. second stage surgery and follow up visits: at the fourth week, the second stage surgery was done using xts 4.0 soft tissue punch (dentium., korea) to excise the gingiva covering the top of the implant fixture under local anesthesia. the cover screws were exposed and removed and secondary implant stability measurements recorded in a similar technique of primary stability measurement. at that time a proper healing abutments (gingival former) were placed according to the site of implants, gingival thickness and inter-ridge distance. then, measurement of secondary implant stability was done at 8, and 12 weeks after implants placement time, after removal of the gingival former and fix the smartpeg as in the measurement of the primary stability fig (4&5). figure (4): detaching of healing abutments 12 weeks postoperatively. figure (5): secondary implants stability measurement by osstell isq. statistical analysis: data were translated into a computerized database structure. all data analysis was done using spss version 23 software, and minitab version 17 software packages. paired t-test was used to analyze continuous variables that followed prospectively in time, and to compare two groups (study and control) at two different periods, repeated measure of anova test (two ways anova) used to see which of them is significantly better. mantel-haenszel-cochran (mhc) test was used to see whether control or j bagh college dentistry vol. 29(4), december 2017 effect of platelet oral and maxillofacial surgery and periodontics 61 study groups better in achieving isq ≥ 70 from baseline until the end of treatment at 12 weeks. results from the nineteen patients who initially participated in this study, two patients had a flap dehiscence before removing the suture, both were in the control group; these two patients were managed by irrigation, refreshing the flap edges and sutured again. one case completely healed without further complication, while for the other case the control implant fixture was lost during the 4th weeks after surgery, so the case was excluded from the study, also another control implant in another patient was lost during the 4th week in this study. therefore, two patients were excluded, so the actual number of patients who complete the study after exclusion was 17 patients with 56 implant fixtures. making the survival rate for all patients who initially participated in this study before exclusion 96.56% (93.1% in control group and 100% in study group), within the limit of the study time. bone quality around implants was judged according to lekholm and zarb classification as follows; four implants were placed in type 1 bone density, two implants in type 2 bone, 46 implants in type 3 bone, and two implants in type 4 bone. no statistical significant correlation existed between bone density and implants stability in both groups. comparing the effect of healing periods on isq between study and control group. immediate postsurgical (primary stability) the mean and standard deviation values of isq were 73.15 ± 8.41 for the study group and 75.52 ± 4.93 for the control group. at the end of the 4th week, the mean and standard deviation values of isq were 68.1 ± 7.52 for the study group and 68.52 ± 8.84 for the control group. therefore, there was a significant reduction in stability compared to the primary stability for both groups with (p=0.023) for the study group and (p=0.001) for the control group. then from the 4th week till 8th week there was a significant increase in mean isq, the mean and standard deviation values of isq were 71.75 ± 8.08for the study group and72.48 ± 6.07 for the control group and this increase in stability was significant for both groups (p=0.009) for the study group and (p=0.005) for the control group. finally, in the third record at the 12th week, the mean and standard deviation values of isq were 74.46 ± 8.06 for the study group and 75.04 ± 6.16 for the control group, displaying a significant increase in mean isq from the 8th week toward 12th week, (p=<0.001) for both groups fig. (6). however, when comparing the differences in stability between the study and the control group at each time point record, these differences were statistically not significant (p=0.507). figure (6): comparison of the changes in mean of isq in both control and study group throughout the healing periods after surgery. discussion nowadays, dentists are facing a new challenge in modern implant dentistry to meet the esthetic and functional expectations of the patients within a short time. researchers have attempted to accelerate and enhance the process of osseointegration to achieve these expectations. in this study, the hypothesis was based on this concept, by using of prf to improve implant stability by accelerate bone formation and osseointegration. although, the three records of secondary stability in both groups follow nearly the same pattern, but the mean of isq in the study group exhibited less reduction in stability than that of the control group when compared to the primary stability, especially in the early healing periods at j bagh college dentistry vol. 29(4), december 2017 effect of platelet oral and maxillofacial surgery and periodontics 62 the 4th week record. on the other hand, when comparing the differences in stability between the study and control group at each time point record, these differences were statistically not significant (p value > 0.05). understanding these results may require more definitive examination methods at the histological level with a precise radiographical examination for assessment of osseointegration along with the resonance frequency analysis. since, in this study, the average isq at surgery for the control group was 75.52 and for the study group was 73.15, indicating a high primary stability that was higher than the results obtained by different studies as al-gailani & abdullateef 2015(9) & öncü & alaaddinoglu, 2015(3). thus, the secondary stability will be high in most occasions. therefore, no big statistical difference between primary and secondary stability will be measured. sennerby and meredith in 2002(10) considered that isq ≥ 70 is a high level of stability, and predict that if the initial isq value is high, a small drop in stability normally levels out throughout the healing periods. this result was in agreement with monov et al. (2005)(11) who placed 34 dental implants in the mandibular arch and applied prp to the implant osteotomies on one side, then followed the variations in the stability of the implants with rfa every 4 days until the 44th day after implants placement. it is found that there were no statistically significant differences between prp+ and prp– implants in terms of stability and stated that the healing process has only a little influence on future implant stability if the primary stability is high, and if the primary stability is high it can predict that secondary stability will be high in most instances. from statistical point when the study depends on rfa only, especially in cases of high primary stability, it may not reflect the real effect of the studied material(9). moreover, al-gailani & abdul-lateef in 2015 (9) also found that at all time points the prp implants have a consistently greater isq values than that of the control implants, but also it was statistically not significant. the explanation for this result may be revealed: 1. the degree and effect of compression, which may damage the platelets and exude significant quantities of valuable growth factors cannot be measured. in addition, considerable quantities of growth factors, which are believed to be involved in tissue regeneration, are really removed by pressing. therefore, the squeezing process could influence the quality and clinical effectiveness of the prf preparations(12,13). 2. since the early times of development of prf, researchers detected that the (weight and size) of the leukocytes-prf clot are affected by the protocol of centrifugation and the selection of centrifuge. many studies did not use the same centrifuge and tubes and did not get the same product, even if the protocols appeared identical same gravitational force (g force) and centrifugation time(14). other studies in contrast with this study results, showed that prf application significantly increase implants stability during the early healing period (1st month after implantation), and stated that simple application of this material seems to provide faster osseointegration(3). furthermore, another study showed that more rapid healing process and bone formation in implants with prf than in the control implant, as proved by histological examination. beside immunohistochemical findings revealed high positive expression for insulin like growth factor (igf) and platelet derived growth factor (pdgf) in experimental implant in comparison to control one(7). in this study most of the implants (43 implant fixtures) were placed in d3 bone type, and no significant correlation existed between bone density and (primary and secondary stability) in both study and control groups. similar results were also published by bischof et al. in 2004(15) who observed that bone type did not influence implant primary stability and implant stability after 12 weeks. while, in contrast many studies revealed that the local bone density has a dominant influence on primary implant stability, which is an important determinant for implant success(16, 17). in conclusions, within the limitations of this study, when comparing the control and study group throughout the three-time points follow up periods the prf exhibited no statistical beneficial effect on implant stability. however, prf showed a significant effect on implants stability by 2.367 folds for implants that achieved primary stability ≥ 70 and maintained this stability after 12 weeks. no significant correlation was found between local bone density and implant stability in both groups. further clinical and histological studies are required to get more precise results about the effect of prf on osseointegration. j bagh college dentistry vol. 29(4), december 2017 effect of platelet oral and maxillofacial surgery and periodontics 63 references 1 chaturvedi, t. p. 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(2002). resonance frequency analysis: current knowledge and clinical implications; 32: 1-9. 11 11monov, g., fuerst, g., tepper, g., watzak, g., zechner, w., & watzek, g. (2005). the effect of platelet‐rich plasma upon implant stability measured by resonance frequency analysis in the lower anterior 12 mandibles. clinical oral implants research, 16(4), 461-465. 13 12su, c. y., kuo, y. p., tseng, y. h., su, c. h., & burnouf, t. (2009). in vitro release of growth factors from platelet-rich fibrin (prf): a proposal to optimize the clinical applications of prf. oral surgery, oral medicine, oral pathology, oral radiology, and endodontology, 108(1), 56-61. 14 13burnouf, t., lee, c. y., luo, c. w., kuo, y. p., chou, m. l., wu, y. w., & su, c. y. (2012). human blood-derived fibrin releasers: composition and use for the culture of cell lines and human primary cells. biologicals, 40(1), 21-30. 15 14ehrenfest, d. d., kang, b. s., del corso, m., nally, m., quirynen, m., wang, h. l., & pinto, n. r. (2014). the impact of the centrifuge characteristics and centrifugation protocols on the cells, growth factors and fibrin architecture of a leukocyte-and platelet-rich fibrin (l-prf) clot and membrane. part ii: evaluation of the vibration shocks of 4 models of table centrifuges for l-prf. poseido; 2(2):141-54. 16 15bischof, m., nedir, r., szmukler‐moncler, s., bernard, j. p., & samson, j. (2004). implant stability measurement of delayed and immediately loaded implants during healing. clinical oral implants research, 15(5), 529-539. 17 16merheb, j., temmerman, a., rasmusson, l., kübler, a., thor, a., & quirynen, m. (2016). influence of skeletal and local bone density on dental implant stability in patients with osteoporosis. clinical implant dentistry and related research, volume 18, issue 2; pp. 253–260. 18 17anil, s., & aldosari, a. a. (2015). impact of bone quality and implant type on the primary stability: an experimental study using bovine bone. journal of oral implantology, 41(2), 144-148. j bagh college dentistry vol. 29(4), december 2017 effect of platelet oral and maxillofacial surgery and periodontics 64 تأثير الليفين الغني بالصفيحات الدموية على ثبات زرعات األسنان الخالصة بسيطة ومنخفضة التكلفة وقليلة العنف للحصول على التركيز الطبيعي من هي طريقة(prf) دم الفيبرين الغني بصفائح ال الخلفية: عوامل النمو ذاتي التي يتم استخدامها على نطاق واسع لتسريع شفاء األنسجة الناعمة والصلبة، وبالتالي فإنه يستخدم في مختلف ( لزرعات األسنان التي rfaالمقاسة بتحليل تردد الرنين )لزرعات استقرار المقارنة والهدف من هذه الدراسة كانمجاالت الطب. أدخلت في بروتوكول جراحي على مرحلتين مع أو بدون وضع الفيبرين الغني بصفائح الدم. متماثلة أو/ و أكثر من األسنان المتجاورة المفقودة أو واثنين فمريضا معافى, وله عظم سنخي كاتسعة عشر وطرق البحث: المواد من اثنتان األقل على. الدراسة هذه في قبل إدراجها األقل على أشهر 6اقتلعت الفم(, والتي انقسام تصميم) الوسط خط على نائياث للزراعة، وضع الليفين الغني ةالجراحي إعداد المغارس مريض, وبعد كل في وضعت ،(كوريا شركة العاجية،) األسنان زرعات بينما المغرس الثاني زرع بدون وضع ، (مجموعة الدراسةوضع الزرعة ) قبل مغارس الزرعة من واحدة في بصفائح الدم عشوائيا tm osstellباستخدام (rfa)بواسطة تحليل تردد الرنيناستقراريه الزرعات قيست الليفين الغني بصفائح الدم )مجموعة السيطرة(. isq )بعد أسبوع 21 و 8 و 4 وعند االستقرار األولي( ،)الزرعات في وقت وضع , أوال قيست)غوتنبرغ ,السويد, الجيل الرابع (.الثانوي االستقرار) الجراحي العمل دراسة مجموعة أل في isq)حاصل ثبات الزرعة ) معدلفأن الثانوي، االستقرار التسجيالت الثالثة من في أن من الرغم على :النتائج مجموعة مع المبكرة عند األسبوع الرابع مقارنة الشفاء فترات في خاصة لى)مجموعة الليفين الغني بالصفيحات الدموية( كان أع أخرى، ناحية ومن .(p> 0.05 قيمة) إحصائيا يعتد به ال االرتفاع هذا السيطرة )بدون إضاقة الليفين الغني بالصفيحات الدموية(, ولكن ≤ حققت استقرار أولي للزراعات التي 2.367 بقوة ار الزرعاتاستقر عملية كبيرا على تأثيرا الليفين الغني بالصفيحات الدموية أظهر .أسبوع 21 بعد االستقرار وحافظوا على هذا 07 كان اعلى في مجموعة الدراسة في isqوعلى الرغم من أنه وجد بان معدل أل, الدراسة هذه حدود ضمن :والمقترحاتاالستنتاجات تبين أن الليفين الغني بالصفيحات الدموية أظهر تأثيرا .ذا االرتفاع ال يعتد به إحصائياجميع مراحل المتابعة خالل فترة الشفاء وكان ه أن أسبوع. لذلك يبدو 21وحافظوا على هذا االستقرار ل 07≤ عف للزرعات الالتي حصلن على استقرار أساسي ض( 3671.مهم ب ) .االستقرار من عال مستوى على مي للزرعات ويحافظلليفين الغني بالصفيحات كبيرا على االندماج العظ التأثير الكامل 12. hawraa f.docx j bagh college dentistry vol. 27(4), december 2015 thickness of oral diagnosis 78 thickness of buccal bone at various sites of the mandible and its clinical significance in monocortical screws placement using multi-slice computed tomography hawraa noori atallah, b.d.s.(1) lamia h. al-nakib, b.d.s., m.sc. (2) abstract background:open reduction and internal fixation (orif) of using miniplates and screws is the treatment of choice of mandibular fractures. it is important to know both: the region where the bone provides a firm anchorage, and the topography of the dental apices and inferior alveolar nerve to avoided imaging them when inserting the screw. the aim of this study is to determine the thickness of buccal cortical plate and that of buccal bone at the parasymphysis and mandibular body, thereby determining the area that provide a firm anchorage and the maximum length of mono-cortical screws that can be safely placed in these regions without injuring the tooth roots or mandibular nerve. materials and methods: the sample of the present study was 110 iraqi subjects (77 males & 33 females) aged (18-35) years old who admitted to computed tomography scan unit in al-sadr teaching hospital in al-najaf city to get computed tomographic examination of facial bones. the conventional sections of ct (axial, coronal) used to do the measurements and dental planning analysis also used. the thickness of buccal cortical plate and the thickness of buccal bone were measured at the level of root apex of (canine, first premolar, second premolar) and at the level ofroot apex and inferior alveolar canal in mesial and distal root of first and second molar. results: there was no statistical significant difference in buccal cortical plate and buccal bone thickness between age and gender at most measured sites. using of 4mm screw is safe in distal root region of 2nd molar at the level of apex and that of inferior alveolar canal for both males and females. moving slightly forward in position to the mesial root of 2nd molar 1mm will be lost from safety margin, while making only the 3mm screw is safe. for the remaining anterior positions only the minimum screw length of 2 mm is safe. conclusions: thickness of buccal cortical plate and buccal bone in various sites could be measured precisely using multislice computed tomography which can guide surgeons in selecting the proper screw length without causing injury to tooth apex or inferior alveolar nerve. keywords: mandibular fracture, buccal bone, mini-plate, computed tomography. (j bagh coll dentistry 2015; 27(4):78-84). introduction computed tomography (ct) scanning is the best option to the present date for the diagnosis, surgical planning, and treatment of bone lesions, owing to its specific properties(1).multi-detector (multislice) computed tomography (mdct) is considered one of the most valuable imaging modalities for preoperative procedures, because it allows the acquisition of fast, reliable and reproducible images (2). the mandible is the largest, strongest and lowest bone in the face. it has a horizontally curved body that is convex forwards, and two broad rami that ascend posteriorly (3). the mandibular canal is a canal within the mandible that contains the inferior alveolar nerve, and inferior alveolar vein. it runs obliquely downward and forward in the ramus, and then horizontally forward in the body, where it is placed under the alveoli and communicates with them by small openings(4).mandibular fracture is one of the most common facial skeletal injuries(5).its main causes are road crashes and violence, and the relation between these causes varies from one country to another. (1) master student, department oral diagnosis, college of dentistry, baghdad university. (2) assistant professor, department oral diagnosis, college of dentistry, baghdad university. the prevalence of mandibular fractures was higher in male subjects in all age groups (6).open reduction and internal fixation (orif) using miniplates and screws are the treatment of choice for mandibular fracture. orif of fractures involving the mandibular body and parasymphysis requires the placement of screws along the ideal line of osteosynthesis; this carries a risk of injury to the roots of the teeth and to the branches of mandibular nerve. miniplate fixation has been shown to bear masticatory forces reliably. screws are used to anchor miniplates to bone; therefore, it is important to know the distance from the outer cortex to the tooth apices and to the inferior alveolar canal to avoid injuring these structures. although the screw should be long enough to provide stability, it should be short enough to avoid damage to any vital structure (7). materials and methods the sample composed of 110 iraqi subjects with age range (18-35) years old. the sample selected from the subjects attendedct unit in alsadr medical city in najaf for facial bone examination from november 2013 till may 2014. the subjects divided into two groups: 1group composed of 58 subjects (40 males, 18 females). 2group composed of 52 subjects (37 male, 15 j bagh college dentistry j bagh college dentistry oral diagnosis female). computed tomography used to do the measurements. the ct machine used was slice multi brilliance ct, v4.0 the images were mas, the slice thickness of the image was 0. mm. the study m cortical plate and buccal bone (cortical and cancellous) in the mandible apex of canine, 1 molar and 2 the measurement in molar area also done at the level of inferior alveolar canal. group of subjects canine, 1 ordinary axial section 1(a,b).the exact tooth and position of the apex can be known by checking the axial section coronal and sagittal section. of subjects the measurements done for 1st premolar, 2 2nd molar (apex, iac) analysis protocol as shown in figure 3(a,b). statistical statistical analyses were done using version 21 computer software (statistical package for social sciences). frequency distribution for selected variables was done first. the outcome quantitative variable (bone thickness measurements at selected areas) was shown to be normally distributed are best described by mean, sd, se. the independent samples t statistical significance of difference in mean between 2 groups. the statistical significance, strength and direction of linear correla quantitative normally distributed variables was assessed by pearson’s linear correlation coefficient. cohen’s d is a standardized measure of effect size for difference between 2 means, which can be compared across different variables and studies, since it has no unit of measurement. cohen’s d = (mean1 groups. cohen’s d< (medium effect), while 0.8 and higher is a large effect. j bagh college dentistry oral diagnosis these groups according to the sections of computed tomography used to do the measurements. the ct machine used was slice multi-detector ct scan brilliance ct, v4.0. images were the slice thickness of the image was 0. the study measures cortical plate and buccal bone (cortical and cancellous) in the mandible apex of canine, 1st molar and 2nd molar. the measurement in molar area also done at the level of inferior alveolar canal. group of subjects, the measurements done for the canine, 1st premolar, ordinary axial section the exact tooth and position of the apex can be known by checking the axial section coronal and sagittal section. of subjects the measurements done for premolar, 2nd premolar, 1 molar (apex, iac) analysis protocol as shown in figure 3(a,b). statistical analysis: statistical analyses were done using version 21 computer software (statistical package for social sciences). frequency distribution for selected variables was done first. the outcome quantitative variable (bone thickness measurements at selected areas) was shown to be normally distributed. such quantitative variables are best described by mean, sd, se. the independent samples t statistical significance of difference in mean between 2 groups. the statistical significance, strength and direction of linear correla quantitative normally distributed variables was assessed by pearson’s linear correlation coefficient. cohen’s d is a standardized measure of effect size for difference between 2 means, which can be compared across different variables dies, since it has no unit of measurement. cohen’s d = (mean1groups. cohen’s d< (medium effect), while 0.8 and higher is a large j bagh college dentistry these groups according to the sections of computed tomography used to do the measurements. the ct machine used was detector ct scanner, philips, holland, generated at 120kv and the slice thickness of the image was 0. easures the thickness of buccal cortical plate and buccal bone (cortical and cancellous) in the mandible at the level of root premolar, 2nd the measurement in molar area also done at the level of inferior alveolar canal. the measurements done for the 2nd premolar only using the ordinary axial section as shown in the exact tooth and position of the apex can be known by checking the axial section coronal and sagittal section. in the second of subjects the measurements done for premolar, 1st molar (apex, iac), molar (apex, iac) using dental planning analysis protocol as shown in figure 2(a,b) and statistical analyses were done using version 21 computer software (statistical package for social sciences). frequency distribution for selected variables was done first. the outcome quantitative variable (bone thickness measurements at selected areas) was shown to be . such quantitative variables are best described by mean, sd, se. the independent samples t-test was used to assess the statistical significance of difference in mean the statistical significance, strength and direction of linear correlation between 2 quantitative normally distributed variables was assessed by pearson’s linear correlation coefficient. cohen’s d is a standardized measure of effect size for difference between 2 means, which can be compared across different variables dies, since it has no unit of measurement. -mean2) / pooled s groups. cohen’s d<0.3 small effect, 0.3 (medium effect), while 0.8 and higher is a large j bagh college dentistry vol. 2 these groups according to the sections of computed tomography used to do the measurements. the ct machine used was ner, philips, holland, generated at 120kv and 250 the slice thickness of the image was 0. the thickness of buccal cortical plate and buccal bone (cortical and at the level of root nd premolar, 1 the measurement in molar area also done at the level of inferior alveolar canal. in the first the measurements done for the premolar only using the as shown in figure the exact tooth and position of the apex can be known by checking the axial section with in the second group of subjects the measurements done for the canine, molar (apex, iac), using dental planning figure 2(a,b) and statistical analyses were done using spss version 21 computer software (statistical package for social sciences). frequency distribution for selected variables was done first. the outcome quantitative variable (bone thickness measurements at selected areas) was shown to be . such quantitative variables are best described by mean, sd, se. the test was used to assess the statistical significance of difference in mean the statistical significance, strength and tion between 2 quantitative normally distributed variables was assessed by pearson’s linear correlation coefficient. cohen’s d is a standardized measure of effect size for difference between 2 means, which can be compared across different variables dies, since it has no unit of measurement. mean2) / pooled sd of the 2 0.3 small effect, 0.3(medium effect), while 0.8 and higher is a large vol. 27(4), december 2015 79 these groups according to the sections of computed tomography used to do the measurements. the ct machine used was 64ner, philips, holland, 250 the slice thickness of the image was 0.9 the thickness of buccal cortical plate and buccal bone (cortical and at the level of root , 1st the measurement in molar area also done at in the first the measurements done for the premolar only using the figure the exact tooth and position of the apex with group the canine, molar (apex, iac), using dental planning figure 2(a,b) and pss version 21 computer software (statistical package for social sciences). frequency distribution for selected variables was done first. the outcome quantitative variable (bone thickness measurements at selected areas) was shown to be . such quantitative variables are best described by mean, sd, se. the test was used to assess the statistical significance of difference in mean the statistical significance, strength and tion between 2 quantitative normally distributed variables was assessed by pearson’s linear correlation coefficient. cohen’s d is a standardized measure of effect size for difference between 2 means, which can be compared across different variables dies, since it has no unit of measurement. d of the 2 -0.7 (medium effect), while 0.8 and higher is a large figure figure (1 figure (2 s ), december 2015 figure (1a): thickness of the figure (1b): thickness of the figure (2a): dental showing thickness of the plate ), december 2015 a): axial section of ct hickness of the buccal atcanine a b): axial section of ct hickness of the buccal apex. : dentalanalysis of ct hickness of the late atcanine thickness of ection of ct showing uccal cortical p apex. ection of ct showing uccal bone atc . nalysis of ct hickness of the buccal c anine apex. thickness of howing plate howing canine nalysis of ct image cortical thickness of j bagh college dentistry j bagh college dentistry oral diagnosis figure (2 showing figure (3 showing j bagh college dentistry oral diagnosis figure (2b):dental howing thickness of the atcanine figure (3a):dental howing thickness of the plate in j bagh college dentistry b):dental analysis of ct hickness of the b anine apex. a):dental analysis of ct hickness of the buccal late in molar area j bagh college dentistry vol. 2 nalysis of ct image buccal bone nalysis of ct image uccal cortical rea. vol. 27(4), december 2015 80 mage one mage ortical figure (3 s results cortical plate and buccal bone thickness was larger in males than difference was too small to reach the level of statistical significance. plate thickness was significantly higher in male compared to female at the level of root apex for canine, 1 the effect of gender on buccal cortical plate thickness was strongest at the level of mesial root apex of 1 level of canine and 1 0.54). significantly higher in male compared to female at the level of root apex for canine and 2 premolar in the buccal cortical plate and buccal bone thickness between the very young age group (18 24 years) and the older one (25 4mm screw was safe in distal root region of 2 molar at the level o alveolar canal for both males and females. moving slightly forward in position to the mesial root of 2 margin, making only remaining anterior positions only the mini screw ), december 2015 figure (3b):dental showing thickness of the results at most measured sites cortical plate and buccal bone thickness was larger in males than difference was too small to reach the level of statistical significance. plate thickness was significantly higher in male compared to female at the level of root apex for canine, 1st premolar and mesial root of 1 the effect of gender on buccal cortical plate thickness was strongest at the level of mesial root apex of 1st molar (cohen's d 0.7) followed by the level of canine and 1 0.54).the mean buccal bone thickness was significantly higher in male compared to female at the level of root apex for canine and 2 premolar(tables there was no obvious or consistent difference in the buccal cortical plate and buccal bone thickness between the very young age group (18 24 years) and the older one (25 mm screw was safe in distal root region of 2 molar at the level o alveolar canal for both males and females. moving slightly forward in position to the mesial root of 2nd molar we will lose 1 margin, making only remaining anterior positions only the mini screw length of 2 ), december 2015 b):dental analysis of ct hickness of the molar area at most measured sites, the mean of the buccal cortical plate and buccal bone thickness was larger in males than females; difference was too small to reach the level of statistical significance. the mean buccal plate thickness was significantly higher in male compared to female at the level of root apex for premolar and mesial root of 1 the effect of gender on buccal cortical plate thickness was strongest at the level of mesial root molar (cohen's d 0.7) followed by the level of canine and 1st premolar (cohen's d he mean buccal bone thickness was significantly higher in male compared to female at the level of root apex for canine and 2 s1,2,3,4). there was no obvious or consistent difference in the buccal cortical plate and buccal bone thickness between the very young age group (18 24 years) and the older one (25 mm screw was safe in distal root region of 2 molar at the level of apex and that of inferior alveolar canal for both males and females. moving slightly forward in position to the mesial molar we will lose 1 margin, making only the 3mm screw safe. for the remaining anterior positions only the mini length of 2mm was safe thickness of nalysis of ct hickness of the buccal b rea. the mean of the buccal cortical plate and buccal bone thickness was females; however difference was too small to reach the level of he mean buccal plate thickness was significantly higher in male compared to female at the level of root apex for premolar and mesial root of 1 the effect of gender on buccal cortical plate thickness was strongest at the level of mesial root molar (cohen's d 0.7) followed by the premolar (cohen's d he mean buccal bone thickness was significantly higher in male compared to female at the level of root apex for canine and 2 there was no obvious or consistent difference in the buccal cortical plate and buccal bone thickness between the very young age group (18 24 years) and the older one (25-35 year) mm screw was safe in distal root region of 2 f apex and that of inferior alveolar canal for both males and females. moving slightly forward in position to the mesial molar we will lose 1mm of safety mm screw safe. for the remaining anterior positions only the mini mm was safe(tables 5, 6) thickness of nalysis of ct image bone in the mean of the buccal cortical plate and buccal bone thickness was however, the difference was too small to reach the level of he mean buccal cortical plate thickness was significantly higher in male compared to female at the level of root apex for premolar and mesial root of 1st molar. the effect of gender on buccal cortical plate thickness was strongest at the level of mesial root molar (cohen's d 0.7) followed by the premolar (cohen's d he mean buccal bone thickness was significantly higher in male compared to female at the level of root apex for canine and 2nd there was no obvious or consistent difference in the buccal cortical plate and buccal bone thickness between the very young age group (1835 year).using of mm screw was safe in distal root region of 2nd f apex and that of inferior alveolar canal for both males and females. moving slightly forward in position to the mesial mm of safety mm screw safe. for the remaining anterior positions only the minimum 6). thickness of j bagh college dentistry vol. 27(4), december 2015 thickness of oral diagnosis 81 table (1): gender difference in the buccal cortical plate thickness at the level of rootsapices b uc ca l c or ti ca l p la te th ic kn es s at th e le ve l o f descriptive statistics female male p-value cohen's d canine apex range 0.9-2.2 0.9-2.4 0.002 0.54 mean 1.4 1.6 n 33 77 1stpremolar apex range 0.9-2.1 0.8-2.4 0.002 0.54 mean 1.5 1.7 n 33 77 2nd premolar apex range 1-3 1-3.5 0.05 (ns) 0.4 mean 1.6 1.8 n 33 77 mesial root apex of 1st molar range 1-3.2 1.5-3.9 0.039 0.7 mean 2 2.4 n 15 37 distal root apex of 1st molar range 1-3.4 1.5-3.7 0.75 (ns) 0.17 mean 2.4 2.5 n 15 37 mesial root apex of 2nd molar range 1.7-3.4 1.5-4.2 0.15 (ns) 0.35 mean 2.5 2.7 n 15 37 distal root apex of 2nd molar range 1.7-4.4 1.2-3.7 0.99 (ns) 0 mean 2.7 2.7 n 15 37 table (2):gender difference in the buccal cortical plate thickness at the level ofiac. b uc ca l c or ti ca l p la te th ic kn es s at th e le ve l o f descriptive statistics female male p-value cohen's d iac at mesial root region of 1st molar range 1.5-3.2 1.5-3.2 1 (ns) 0 mean 2.2 2.2 n 15 37 iac at distal root region of 1st molar range 1.6-4.9 1.2-3.4 0.16 (ns) -0.56 mean 2.5 2.2 n 15 37 iac at mesial root region of 2nd molar range 1.8-3.2 1.2-4.2 0.67 (ns) -0.18 mean 2.5 2.4 n 15 37 iac at distal root region of 2nd molar range 1.7-3.4 1.2-3.4 0.61 (ns) -0.2 mean 2.5 2.4 n 15 37 table (3): gender difference in the buccal bonethickness at the level of roots apices b uc ca l b on e th ic kn es s at th e le ve l o f descriptive statistics female male p-value cohen's d canine apex range 1.2-6.9 1.6-7.8 0.005 0.53 mean 3.7 4.3 n 33 77 1st premolar apex range 1.2-6 1.2-7.1 0.2 (ns) 0.26 mean 3.6 3.9 n 33 77 2nd premolar apex range 1.2-8.7 1-7.1 0.02 0.49 mean 3.5 4.1 n 33 77 mesial root apex of 1st molar range 1-5.9 1.5-6.6 0.09 (ns) 0.49 mean 3 3.6 n 15 37 distal root apex of 1st molar range 1-8.1 3.2-7.6 0.53 (ns) 0.22 mean 4.8 5.1 n 15 37 mesial root apex of 2nd molar range 3.9-11.3 2.7-10.5 0.45 (ns) 0.24 mean 6.9 7.3 n 15 37 j bagh college dentistry vol. 27(4), december 2015 thickness of oral diagnosis 82 distal root apex of 2nd molar range 5.6-10.8 5.6-12 0.4 (ns) 0.21 mean 7.6 7.9 n 15 37 table (4):gender difference in the buccal bone thickness at the level ofiac. b uc ca l b on e th ic kn es s at th e le ve l o f descriptive statistics female male p-value cohen's d iac at mesial root region of 1st molar range 2-6.6 2.2-6.6 0.74 (ns) 0.1 mean 4.7 4.8 n 15 37 iac at distal root region of 1st molar range 2.9-7.1 2.7-9 0.53 (ns) 0.23 mean 5.3 5.6 n 15 37 iac at mesial root region of 2nd molar range 3.2-7.4 3.7-9.7 0.27 (ns) 0.31 mean 5.6 6 n 15 37 iac at distal root region of 2nd molar range 4.2-6.6 3.7-9.1 0.12 (ns) 0.5 mean 5.4 6 n 15 37 table (5):predicted injury to tooth apex and inferior alveolar nerve using different screw lengths with a standard plate thickness of 1mm (female) table (6):predicted injury to tooth apex and inferior alveolar nerve using different screw lengths with a standard plate thickness of 1mm (male) discussion in general, male gender was associated with a higher bone thickness compared to females. this difference was however too small to reach the level of statistical significance given the constraints of the sample size for the current in ju ry r at e pe rc en ta ge screw length 2 3 4 5 6 7 canine apex 0 6.1 24.2 60.6 93.9 97 1st premolar apex 0 6.1 21.2 72.7 90.9 100 2nd premolar apex 0 15.2 33.3 72.7 90.9 97 mesial root apex of 1st molar 6.7 26.7 60 80 93.3 100 iac at mesial root region of 1st molar 0 6.7 6.7 26.7 53.3 93.3 distal root apex of 1st molar 6.7 6.7 6.7 33.3 53.3 80 iac at distal root region of 1st molar 0 0 6.7 20 40 60 mesial root apex of 2nd molar 0 0 0 6.7 13.3 40 iac at mesial root region of 2ndmolar 0 0 0 6.7 26.7 53.3 distal root apex of 2nd molar 0 0 0 0 0 20 iac at distal root region of 2nd molar 0 0 0 0 40 73.3 in ju ry r at e pe rc en ta ge screw length 2 3 4 5 6 7 canine apex 0 1.3 13 41.6 74 92.2 1st premolar apex 0 6.5 23.4 49.4 85.7 96.1 2nd premolar apex 1.3 2.6 14.3 53.2 80.5 96.1 mesial root apex of 1st molar 0 13.5 29.7 70.3 86.5 94.6 iac at mesial root region of 1st molar 0 0 5.4 27 51.4 89.2 distal root apex of 1st molar 0 0 0 18.9 45.9 70.3 iac at distal root region of 1st molar 0 0 5.4 10.8 29.7 51.4 mesial root apex of 2nd molar 0 0 2.7 2.7 10.8 16.2 iac at mesial root region of 2nd molar 0 0 0 2.7 24.3 54.1 distal root apex of 2nd molar 0 0 0 0 0 5.4 iac at distal root region of 2nd molar 0 0 0 5.4 29.7 51.4 j bagh college dentistry vol. 27(4), december 2015 thickness of oral diagnosis 83 study. in some of the examined points the bone thickness was significantly higher in males. in these points the gender effect was evaluated as a moderately strong effect. at most measured sites the mean buccal cortical plate and buccal bone thickness was larger in males than females. there should be a clear distinction between the findings of a bigger vs. denser-skeleton in males compared to females. a longitudinal study on mice provided strong evidence that skeletal gender dimorphism is determined by independent and time specific effects of sex steroid. although males have a larger bone compared to females the bone density is not affected. in addition the gender differences are likely to be highlighted at certain age intervals(8). hu et,al.,(9) in their study on a sample of 20 dry mandibles showed no statistically significant difference in cortical plate thickness and total bone thickness between males and females. the sample size used in hu study was too small to allow for a valid and meaningful comparison between the two genders. al-jandanet,al.,(7) in their study on a sample of 50 mandibles with an age range comparable to our study reach to a similar conclusion in respect to absence of a noticeable gender difference in buccal cortical or total bone thickness at the tooth apex or iac. the same study also reported some exceptions in the general conclusion. for example a higher buccal bone thickness in males compared to females in the 2nd molar region. one of the plausible explanations of the absence of consistent differences in gender is the wide range of individual variations in facial type and teeth inclinations especially in the buccolingual direction which greatly affects the bone thickness. masumoto et,al.,(10) stated that facial types are associated with the cortical bone thickness of the mandibular body and with the buccolingual inclination of 1st and 2nd molar. the sampling units in the current study were selected in a restricted age interval. all the study subjects of the present study were young adults with an age ranging between 18-35 years. therefore the study failed in detecting any obvious or consistent difference in the buccal cortical plate and buccal bone thickness between the very young age group (18-24 years) and the older one (25-35 year). riggs et,al.,(11) in their population-based study about age and sex differences in bone volumetric density and size at different skeletal sites concluded that age related bone loss begins after the age interval used in the current study. wowern and stoltze(12) argued that the mean cortical width (mcw) and absolute bone mass are greater in males than in females and show a parallel age related decrease after the age of 50. furthermore, the age related increase in cortical thinning and porosity is dependent on the individual as well as on age. marked individual variation may limit the use of these parameters to group analysis. hu et,al.,(9) failed to detect any association between the age and buccal cortical plate thickness or total bone thickness in a sample of 20 mandibles. many studies recommended the use of screws 5-7mm long to ensure good fixation in combination with standard miniplates of 1mm thickness(13,14). the current study employed the worst estimate scenario in predicting injury to tooth apex or nerve. it was found that the use of 4mm screw was safe in distal root region of 2nd molar at the level of apex and that of inferior alveolar canal for both males and females. moving slightly forward in position to the mesial root of 2nd molar we will lose 1mm of safety margin, making only the 3mm screw safe. for the remaining anterior positions only the minimum screw length of 2mm is safe. the minimum screw length of 5mm recommended by previous studies may result in a very low injury rate ranging between 2.7 and 5.4 in both genders at the molar region. one may consider such a risk as a very low one and may be willing to tolerate at the expense of good stability. the maximum recommended screw length of 7mm on the other hand is too risky since the injury rate may be up to 73.3% in the molar region. needless to say that the injury rate will increase steeply to reach up to 100% with 7 mm screw length. al-jandanet,al.,(7) reported similar measurements for buccal cortical plate and buccal bone thickness at the level of teeth apices from canine to 2nd molar. no stratified analysis by gender was done and the exact tooth root for molars was not specified. direct comparison with findings from other studies will not be possible in all measured sites. leonget,al.,(13) studied 26 dentate jaws cadavers. the average buccal cortical plate thickness in dentate mandibles was 2.76mm. this figure is comparable to the maximum estimate in our study for cortical plate (2.7mm for 2nd molar root apex) and is expected to be higher than the overall average. katranjiet,al.,(14) in their study to determine the average thickness of buccal and lingual plates, 28 cadaver heads (68% male and 32% female) with an average age of 73.1 years were measured at various locations correlating to molar (m), premolar (pm), and anterior (a) regions and found that the buccal cortical bone thickness in the area of premolars 1.2mm, which is lower than j bagh college dentistry vol. 27(4), december 2015 thickness of oral diagnosis 84 the current study result (1.5-1.7 mm) for females and males respectively. in molar area they found that the buccal cortical bone thickness was 1.98 mm which is also lower than the current study result (2.4-2.6mm) for females and males respectively. this difference may be due to the average age of the cadavers in their study being 73.1 years. hu et,al.,(9)reported the mean buccal cortical plate thickness as 1.5mm in the canine region, 2.2mm in the premolar region and 3.8mm in the molar region. the previously mentioned measurements were done using dried mandibles and a strict cross sectional plane. it is therefore expected that these measurements are over estimates for the measurements done in our study in which the distance was measured perpendicular to bone surface. jin et,al.,(15) had their study on a sample of 66 individuals examined by ct scan to measure buccal bone thickness at the level of 1st and 2nd molar root apex without referring to gender. they reported a mean of 8.5 mm at the distal root of 2nd molar which is slightly higher than the current study estimate (7.6-7.9 mm for females and males respectively). the mean buccal bone thickness at the mesial root of 2nd molar was comparable (7.3mm) to our estimate (6.9-7.3mm for females and males respectively). the same study of jin et,al.,(15) reported a mean of 5.2mm at the distal root of 1st molar which is comparable to the current study estimate (4.8-5.1mm for females and males respectively). the mean buccal bone thickness at the mesial root of 1st molar was slightly higher (4.1mm) than our estimate (3-3.6mm for females and males respectively). levineet,al.,(16) reported that the inferior alveolar canal was of 4.9 mm from the buccal cortex at the 1st molar region. these estimates are close to the present study results, the mean buccal bone thickness at mesial root region in male 4.8 mm and in female 4.7 mm. nagadiaet,al.,(17)reviewed ct scans of mandible for a sample of chinese adults, emphasizing the anatomical position of the mandibular canal in relation to cortical bone and molar teeth the mandibular canal was farthest from the buccal cortex at the second molar region (mean buccal bone thickness of 6.79 mm and a minimum of 4.80 mm). these estimates were higher than the current study measurements (mean buccal bone thickness of 5.6 to 6mm and a minimum of 3.2 to 3.7 for females and males respectively). references 1. sekerci ae, sahman h, sismany, aksu y. morphometric analysis of the mental foramen in a turkish population based on multi-slicecomputed tomography. joral maxillofacradiol 2013; 1:2-7. 2. rydberg j, liang y, teague sd. fundamentals of multichannel ct. radiolclin north am 2003; 41: 465–74. 3. susan s. gray's anatomy: the anatomical basis of clinical practice. 4thed. london: elsevier; 2008. 4. greenstein g, cavallaro j, tarnow d. practical application of anatomy the dental implant surgeon. j periodontol 2008; 79: 1833-46. 5. pavan kb, sumanth k, rahul. open reduction and internal fixation of mandibular fractures. indian j dent advancements 2009; 1: 72-5. 6. sakr k, farag ia, zeitoun im. review of 509 mandibular fractures treated at the university hospital, alexandria, egypt. br j oral maxillofacsurg2006;44:107-11. 7. al-jandan ba, al-sulaiman aa, mari hf, syed fa, almana m. thickness of buccal bone in the mandible and its clinical significance in mono-cortical screws placement. a cbct analysis. international j oral maxillofacsurg 2013; 42:77-81. 8. callewaert f, venken k, kopchick jj, torcasio a, lenthe ghv, boonen s, vanderschueren d. sexual dimorphism in cortical bone size and strength but not density is determined by independent and timespecific actions of sex steroids and igf-1: evidence from pubertal mouse models. american society for bone and mineral research 2010; 25(3): 617-26 9. hu ks, kang mk, kim tw, kim kh, kim hj. relationships between dental roots and surrounding tissues for orthodontic mini-screw installation. angle orthod 2009; 79: 37–45. 10. masumoto t, hayashi i, kawamura a, tanaka k, kasai k. relationships among facial type, buccolingualmolar inclinations and cortical bone thickness of the mandible.eur jorthod2001;23:15-23. 11. riggs bl, melton ilj, robb ra, camp jj, atkinson ej, peterson jm, rouleau pa, mccollough ch, bouxsein ml, khosla s. a population-based study of age and sex differences in bone volumetric density, size, ggeometry and structure at different skeletal sites. j bone mineral research 2004; 19(12): 1945-54. 12. wowern nv, stoltze k. pattern of age related bone loss in mandibles. eur j oral sci1980;88(2): 134-46. 13. leong dj, li j, moreno i, wang hl. distance between external cortical bone and mandibular canal for harvesting ramus graft: ahuman cadaver study. jperiodontol 2010; 81(2): 239-43. 14. katranji a, mischk,wang hl. cortical bone thickness in dentate and edentulous human cadavers. journal of periodontology 2007;78(5):874-8. 15. jin gc, kim kd,roh bd, lee cy, lee sj. buccal bone plate thickness of the asian people. j endo 2005; 31(6): 430–4. 16. levine mh, goddard al, dodson tb. inferior alveolar nerve canal position: a clinical and radiographic study. j oral maxillofacsurg 2007;65: 470–4. 17. nagadia r, tay abg, chan ll,chan esy. the spatial location of the mandibular canal in chinese: a ct study. international j oralmaxillofacsurg 2011; 40(12): 1401–5. noor f.doc j bagh college dentistry vol. 27(3), september 2015 assessment of dental oral and maxillofacial surgery and periodontics 109 assessment of dental implant stability during healing period and determination of the factors that affect implant stability by means of resonance frequency analysis (clinical study) noor s. ibraheem, b.d.s. (1) sahar s. al-adili, b.d.s., m.sc. (2) abstract background: implant stability is considered one of the most important factors affecting healing and successful osseointegration of dental implants. the aims of the study were to measure the implant stability quotient (isq) values during the healing period and to determine the factors that affect implant stability. materials and methods: thirty patients enrolled in the study (17 female, 13 male). they received 44 implantium® dental implants located as the following: 22 implants in maxillary jaw, 22 implants in mandibular jaw from them 17 implants in anterior segment and 27 in posterior segment. the bone density determined using interactive ct scan and classified according to the misch bone density classification (29 implants in (d3), 15 implants in (d4)). resonance frequency analysis was used for direct measurement of implant stability on the day of implant placement and 8, 16 and 24 weeks after implant placement. results: the lowest mean of average isq was at the 8th week (69.5) and then the mean increased to reach at the 24th week (76.8). mandibular implants showed significantly higher isq values than maxillary implants. implants placed in the posterior segment of the jaw had significantly higher isq values than implants in the anterior segment. a significant, positive linear correlation was observed between the implant diameter and the implant stability (r=0.343 p<0.001). conclusion: resonance frequency analysis was non-invasive diagnostic tool for detecting changes in implant stability during the healing period. the factors that affect implant stability were implant diameter and implant location (maxilla\ mandible, anterior\ posterior). keywords: dental implant, implant stability, implant stability quotient (isq), resonance frequency analysis. (j bagh coll dentistry 2015; 27(3):109-115). introduction dental implants have recently become a reliable and predictable tool for oral rehabilitation. even though the clinical outcome of an implant is influenced by many factors, including the implant body, skill of the surgeon, and the oral environment, the key factor for success is implant stability (1). dental implant stability is a measure of the anchorage quality of an implant in the alveolar bone. dental implant stability divided into primary stability at placement which is a mechanical phenomenon and secondary stability which is the increase in stability attributable to bone formation and remodeling at the implantbone interface (2). different diagnostic methods aimed to assess implant stability have been suggested: histology and histomorphometry, insertion torque, removal torque, push-through and pull-through, radiographic assessment, periotest ultrasonic method, and resonance frequency analysis (rfa) (2). among these test methods, rfa offers a clinical, noninvasive measure of stability and presumed osseointegration of implants (2-8). (1)master student. department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2)assistant professor. department of oral and maxillofacial surgery, college of dentistry, university of baghdad. rfa technique is a bending test of the implant– bone complex where a transducer applies an extremely small bending force. the bending force applies a fixed lateral force to the implant and measures the displacement, thus mimicking the clinical loading (9). osstell devices have been designed to measure implant stability using rfa since 1999 by the integration diagnostics ltd. company (sävedalen, sweden). within the last decade, several generations of this device have been developed. the latest generation is the osstell® isq. the rfa values are represented by a quantitative unit called the implant stability quotient (isq) on a scale from 0 to 100 (100 being maximum implant stability) (10). several studies demonstrated a good correlation between the obtained isq values and the degree of stiffness between the implant and the bone (2, 9-12). achievement and maintenance of dental implant stability is the most important requirement for successful dental implant treatment (13). so it is important to determine the factors that influence implant stability. there are several factors affecting primary and secondary stability. primary implant stability is affected by factors related to bone properties (i.e. bone density), implant design (i.e. diameter, length, shape and surface) and surgical technique. j bagh college dentistry vol. 27(3), september 2015 assessment of dental oral and maxillofacial surgery and periodontics 110 secondary implant stability is affected by bone response to the surgery and implant material (14). from these factors bone density needs preoperative assessment as it considered a key factor to take into account when predicting implant stability (15). several methods for bone density assessment have been reported: conventional radiography, drilling resistance, insertion torque force, digital image analysis, and computed tomography (ct) (16). of these methods computed tomography (ct) provide more accurate determination of bone density before surgery (17). materials and methods thirty patients were drawn from patients attending the dental implant clinic in the department of oral and maxillofacial surgery/ college of dentistry/ university of baghdad participated in this clinical prospective study including 13 male and 17 female with age range (20-59) year’s old. the inclusion criteria were as follows: healthy patients with no signs and symptoms of any systemic diseases with age ranges from 20 to 60, non-smoker patients, implant site does not need any bone augmentation or sinus lift and without any fenestrations or dehiscence and all the patients treated according to traditional protocol (delayed implant placement) six months or longer after tooth extraction. the patients received 44 dental implants (implantium® (dentium, seoul, korea)), 22 implants in the maxillary jaw and 22 implants in the mandibular jaw from them 17 implants in anterior segment and 27 in the posterior segment. according to interactive ct scan measurements, bone density at the implant sites ranged from 150 to 784 hounsfield units. this means that the bone density of the implant sites of the sample is either d3 or d4 according to the misch bone density classification (17). preoperative standardized digital orthopantograph (opg) and interactive ct scan were taken for each patient (opg will give an overview of the anatomical structures of the jaw while the ct scan offers more specific data such as length, width and bone density in the proposed implant site). prior to the surgical procedure, a case sheet was filled with all the required information about the patient and every patient signed an informed consent. patient preparation just right before the surgery, the patient rinsed his mouth with chlorhexidine mouthwash for 1 minute to minimize the number of oral microorganisms. then local anesthesia was given using infiltration technique for the maxillary and mandibular arches. surgery after soft tissue incision, the flap was raised and the implant site was prepared by using high torque handpiece at low speed 800 rpm, with sharp drills and copious external irrigation to prevent excess thermal injury to the recipient bone. the implant osteotomy site was sequentially enlarged to the desired length and diameter. no countersink drills was used for all the patients. after reaching the desired length and diameter of the implant bony bed, the implant was placed with external irrigation to prevent heat generation due to friction of the implant and the bone. the cover screw was placed and then the wound edges were brought together and sutured. verbal postoperative instructions were given to the patient. the patients provided with prescription of antibiotics and analgesics. implant stability measurements implant stability measurements were taken at surgery (primary stability) and at 8, 16, 24 weeks after surgery. the values were measured using osstell® isq (integration diagnostics ab, gothenburg, sweden). screw the smartpeg® of osstell® isq to the implant by using the smartpeg mount then hold the instrument probe close to the top of the smartpeg® without touching it. an audible sound will be emitted when the instrument senses the smartpeg® and an isq value is generated and shown on the display. the measurements were taken first from the mesiodistal direction (md) (along the jaw line), then from the bucco-palatal direction (bp) (perpendicular to the jaw line). the measurements reflect the level of stability on the universal isq scale – from 1 to 100 (the higher the isq value, the more stable is the implant). then unscrew the smartpeg® using the smartpeg mount. all measurements were taken by another colleague. after the 24th week, the data were translated into a computerized database structure and statistical analyses were done using spss version 21 computer software (statistical package for social sciences) in association with microsoft excel 2010. j bagh college dentistry vol. 27(3), september 2015 assessment of dental oral and maxillofacial surgery and periodontics 111 results and discussion the effect of healing time on implant stability quotient (isq) by calculating the average isq of the two perpendicular measurements (bucco-palatal direction (bp) and mesio-distal direction (md)) as shown in table (1), we found that the mean of average isq reduced by (3.7) units at the 8th week compared to the primary stability value. this mean reduction was statistically significant and rated as moderate effect. at the 16th week after surgery, the mean of average isq was increased by very small amount (0.3) compared to the primary stability value. this minor change was not significant statistically and rated as very week or almost no effect. at the 24th week (the end of the follow up period), the mean of average isq was increased by (3.6) units compared to the primary stability value. this increase was statistically significant and rated as moderate effect. table 1: the changes in average isq of 2 perpendicular measurements (bp and md) after 3 successive time intervals following surgery compared to primary stability achieved at surgery time at surgery (primary stability) after 8 weeks changes after 8 weeks compared to primary stability after 16 weeks changes after 16 weeks compared to primary stability after 24 weeks changes after 24 weeks compared to primary stability range (56 to 85) (51 to 80) (-31 to 18) (62.5 to 82) (-14.5 to 20.5) (69.5 to 84) (-10 to 24) mean 73.2 69.5 -3.7 73.5 0.3 76.8 3.6 sd 6.3 6.4 8.1 5 6.9 4.2 6.5 se 0.96 0.96 1.22 0.75 1.04 0.63 0.97 n 44 44 44 44 44 44 44 cohen's d (effect size compared to primary stability) -0.46 0.04 0.55 paired t-test 0.004 0.8[ns] <0.001 rate of implants achieving high stability (isq≥70) at surgery and after 3 successive time intervals following surgery the threshold level in this study was set to 70 isq. at surgery, almost three quarters (72.7%) of the studied implants attained high mean isq (isq≥70). this rate decreased to (59.1%) after 8 weeks then increased to (72.7%) at the 16th week after surgery. at the end of the study period at the 24th week after surgery, almost all the studied implants attained high mean isq (97.7%) as shown in figure (1). figure 1: bar chart showing the rate of implants achieving high stability (isq≥70) at surgery and after 3 successive time intervals following surgery. j bagh college dentistry vol. 27(3), september 2015 assessment of dental oral and maxillofacial surgery and periodontics 112 the effect of each factor (gender, age, maxilla\mandible, anterior\posterior, bone density) on implant stability quotient (isq) during the healing period the effect of the gender implant stability quotient (isq) during the healing period as shown in table (2), we found that the mean of average of isq in male were higher than female with a difference in mean of (3.6) units at the time of surgery but this was not significant statistically and rated as moderate effect. at the 8th week after surgery, the difference in mean reduced to (1.9) units and male still higher than female but this was not significant statistically and rated as week effect. at the 16th week after surgery, the difference in mean reduced again to (1) unit and male still higher than female but this was not significant statistically and rated as weak effect. at the 24th week after surgery (the end of follow up period), the difference in mean were slightly raised by (1.3) units being higher in male than female but this was not significant statistically and rated as weak effect. table 2: the mean of average isq of 2 perpendicular measurements (bp and md) showing the female/ male difference in mean at surgery and after 3 successive time intervals following surgery time gender range mean sd se n p difference in mean cohn’s d at surgery female (56 82) 71.9 7 1.33 28 0.07[ns] 3.6 0.59 male (66 85) 75.5 4.2 1.06 16 8th week female (51 80) 68.8 6.7 1.26 28 0.34[ns] 1.9 0.3 male (59 76) 70.7 5.8 1.45 16 16th week female (65.5 82) 73.1 4.8 0.91 28 0.52[ns] 1 0.2 male (62.5 79) 74.1 5.3 1.33 16 24th week female (69.5 84) 76.4 4.3 0.81 28 0.31[ns] 1.3 0.31 male (70.5 83.5) 77.7 3.9 0.97 16 the effect of the age implant stability quotient (isq) during the healing period: as shown in table (3), there was no statistically significant difference between age groups during the healing period. table 3: the mean of average isq of 2 perpendicular measurements (bp and md) showing the age group difference in mean at surgery and after 3 successive time intervals following surgery time age group (years) range mean sd se n p at surgery <= 29 (66 81) 74 4.7 1.22 15 0.51[ns] 30 39 (72 80) 76 2.9 1.29 5 40 49 (56 82) 71.1 9 2.73 11 50+ (65 85) 72.9 6.3 1.73 13 at 8th week <= 29 (59 80) 67.9 7.2 1.85 15 0.37[ns] 30 39 (66 76) 72.6 3.9 1.74 5 40 49 (63 80) 71.2 5.7 1.72 11 50+ (51 75) 68.5 6.6 1.82 13 at 16th week <= 29 (62.5 82) 72.2 6.1 1.57 15 0.56[ns] 30 39 (70.5 78) 75.5 2.9 1.31 5 40 49 (65.5 80) 74.3 5.5 1.65 11 50+ (67 79.5) 73.4 3.6 0.99 13 at 24th week <= 29 (70.5 83) 76 4.1 1.07 15 0.29[ns] 30 39 (76 83.5) 79.7 2.8 1.23 5 40 49 (69.5 84) 77.6 5.4 1.62 11 50+ (72 82) 76 3.1 0.87 13 the effect of the jaw on implant stability quotient (isq) during the healing period as shown in table (4), mandibular jaw showed higher mean average isq compared to maxillary jaw, with a difference in mean of (3.2) units at the time of surgery but this was not significant statistically and rated as moderate effect. j bagh college dentistry vol. 27(3), september 2015 assessment of dental oral and maxillofacial surgery and periodontics 113 mandibular jaw showed higher mean average isq compared to maxillary jaw, with a difference in mean of (2.5) units at the 8th week after surgery but this was not significant statistically and rated as moderate effect. mandibular jaw compared to maxillary jaw showed statistically significant difference (p 0.012) being higher in mandibular jaw than in maxillary jaw, with a difference in mean of (3.7) at the 16th week after surgery and rated as strong effect. mandibular jaw compared to maxillary jaw showed statistically significant difference (p 0.012) being higher in mandibular jaw than in maxillary jaw with a difference in mean of (3.1) at the 24th week after surgery and rated as strong effect. table 4: the mean of average isq of 2 perpendicular measurements (bp and md) showing the maxilla/mandible difference in mean at surgery and after 3 successive time intervals following surgery time jaw range mean sd se n p difference in mean cohn’s d at surgery maxilla (56 80) 71.6 6.4 1.36 22 0.09[ns] 3.2 0.52 mandible (65 85) 74.8 6 1.29 22 8th week maxilla (59 75) 68.2 5.6 1.2 22 0.2[ns] 2.5 0.39 mandible (51 80) 70.7 7 1.48 22 16th week maxilla (62.5 78) 71.6 4.8 1.02 22 0.012 3.7 0.8 mandible (66.5 82) 75.3 4.5 0.97 22 24th week maxilla (69.5 80.5) 75.3 3.7 0.78 22 0.012 3.1 0.79 mandible (72 84) 78.4 4.1 0.87 22 the effect of the arch location on implant stability quotient (isq) during the healing period as shown in table (5), implant arch location significantly affected implant stability (p<0.001), being lower in the anterior segment than the posterior segment, with a difference with a difference in mean of (-6.5) at the time of surgery and rated as strong effect. at the 8th week after surgery, we found that the mean of average of isq was lower in the anterior segment than the posterior, with a difference with a difference in mean of (-3.8) but this was not significant statistically and rated as moderate effect. at the 16th week after surgery, we found that the mean of average of isq was lower in the anterior segment than the posterior, with a difference in mean of (4.5) and this was significant statistically (p 0.003) and rated as strong effect. at the 24th week after surgery, we found that the mean of average of isq was lower in the anterior segment than the posterior, with a difference in mean of (-4.1) and this was significant statistically (p<0.001) and rated as strong effect. table 5: the mean of average isq of 2 perpendicular measurements (bp and md) showing the anterior/posterior difference in mean at surgery and after 3 successive time intervals following surgery time arch location range mean sd se n p difference in mean cohn’s d at surgery anterior (59 76.5) 69.2 5 1.2 17 <0.001 -6.5 -1.17 posterior (56 85) 75.7 5.9 1.13 27 8th week anterior (59 75) 67.1 5 1.22 17 0.05[ns] -3.8 -0.61 posterior (51 80) 70.9 6.8 1.31 27 16th week anterior (62.5 78) 70.7 4.5 1.09 17 0.003 -4.5 -1 posterior (66.5 82) 75.2 4.5 0.87 27 24th week anterior (69.5 80.5) 74.3 3.4 0.82 17 <0.001 -4.1 -1.12 posterior (71.5 84) 78.4 3.8 0.74 27 the effect of the bone density on implant stability quotient (isq) during the healing period as shown in table (6), we found that the mean of average of isq was slightly higher in very low bone density (d4) than low bone density (d3) at surgery, with a difference with a difference in mean of (0.6) but this was not significant statistically and rated as very week effect. at the 8th week, we found that the mean of average of isq was lower in very low bone density (d4) than low bone density (d3), with a difference with a j bagh college dentistry vol. 27(3), september 2015 assessment of dental oral and maxillofacial surgery and periodontics 114 difference in mean of (-5.2) this was significant statistically (p 0.008) and rated as strong effect. at the 16th week, we found that the mean of average of isq was lower in very low bone density (d4) than low bone density (d3), with a difference with a difference in mean of (-2.4) but this was not significant statistically and rated as moderate effect. at the 24th week, we found that the mean of average of isq was lower in very low bone density (d4) than low bone density (d3), with a difference with a difference in mean of (2.3) but this was not significant statistically and rated as moderate effect. table 6: the mean of average isq of 2 perpendicular measurements (bp and md) showing the low (d3)/very low (d4) bone density difference in mean at surgery and after 3 successive time intervals following surgery time bone density range mean sd se n p difference in mean cohn’s d at surgery (d3) (59 85) 73 6.2 1.16 29 0.74[ns] 0.6 0.09 (d4) (56 82) 73.6 6.7 1.74 15 at 8th week (d3) (59 80) 71.2 5.3 0.98 29 0.008 -5.2 -0.88 (d4) (51 80) 66 7 1.82 15 at 16th week (d3) (62.5 80) 74.3 4.9 0.9 29 0.13[ns] -2.4 -0.49 (d4) (66.5 82) 71.9 4.9 1.27 15 at 24th week (d3) (70.5 84) 77.6 3.9 0.73 29 0.08[ns] -2.3 -0.57 (d4) (69.5 83) 75.3 4.3 1.1 15 the effect of implant dimensions (diameter and length) on implant stability quotient (isq) during the healing period as shown in table (7), there was weak positive correlation but statistically significant between implant diameter and mean isq during the healing period. there was very weak negative correlation and not significant statistically between implant length and mean isq during the healing period. table 7: linear correlation coefficient implant dimensions mean isq implant diameter (mm) r=0.343 p<0.001 implant length (mm) r=-0.117 p=0.12[ns] the net effect of time on implant stability quotient (isq) after adjusting the effect of (gender, age, maxilla\mandible, anterior\posterior, bone density, implant diameter and length) as shown in table (8), a multiple linear regression model was used to show the net and independent effect of healing time after surgery after adjusting for a set of explanatory variables on the average isq measured. the follow up period (weeks after surgery) was the strongest predictor for the magnitude of implant stability assessed by average isq, followed by implant diameter (mm) and bone and implant arch location (anterior compared to posterior). implant length, age and jaw location ranked 5th 6th and 7th in order of importance as predictors of implant stability. only gender had no important effect on magnitude of implant stability. references 1. fuh lj, huang hl, chen cs, fu kl, shen yw, tu mg, shen wc, hsu jt. variations in bone density at dental implant sites in different regions of the jawbone. j oral rehabilit 2010; 37(5): 346-51. 2. meredith n. assessment of implant stability as a prognostic determinant. int j prosthodont 1998; 11: 491-01. 3. balleri p, cozzolino a, ghelli l, momicchioli g, varriale a. stability measurements of osseointegrated implants using osstell in partially edentulous jaws after 1 year of loading: a pilot study. clin implant dent relat res 2002; 4(3): 128-32. 4. barewal rm, oates tw, meredith n, cochran dl. resonance frequency measurement of implant stability in vivo on implants with a sandblasted and acid-etched surface. int j oral maxillofac implants 2003; 18(5): 641-51. 5. bischof m, nedir r, szmukler-moncler s, bernard jp, samson j. implant stability measurement of delayed and immediately loaded implants during healing. clin oral implants res 2004; 15(5): 529-39. 6. huwiler ma, pjetursson be, bosshardt dd, salvi ge, lang np. resonance frequency analysis in relation to jawbone characteristics and during early healing of implant installation. clin oral implants res 2007; 18: 275-80. 7. kessler-liechti g, zix j, mericske-stern r. stability measurment of 1-stage implants in the edentulous mandible by means of resonance frequency analysis. int j oral maxillofac implants 2008; 23: 353-8. j bagh college dentistry vol. 27(3), september 2015 assessment of dental oral and maxillofacial surgery and periodontics 115 8. sim cpc and lang np. factors influencing resonance frequency analysis (rfa) assessed by osstell mentor during implant tissue integration. i.: instrument positioning, bone structure, implant length. clin oral impl res 2010; 21: 598-04. 9. sennerby l, meredith n. implant stability measurements using resonance frequency analysis: biological and biomechanical aspects and clinical implications. periodont 2000 2008; 47: 51-66. 10. herrero-climent m, santos-garcía r, jaramillosantos r, romero-ruiz mm, fernández-palacin a, lázaro-calvo p, bullón p, ríos-santos jv. assessment of osstell isq’s reliability for implant stability measurement: a cross-sectional clinical study. med oral patol oral cir bucal 2013; 18 (6): e877-82. 11. becker w, sennerby l, bedrossian e, becker be, lucchini jp. implant stability measurements for implants placed at the time of extraction: a cohort, prospective clinical trial. j periodont 2005; 76: 391-7. 12. zix j, hug s, kessler-liechti g, mericske-stern r. measurement of dental implant stability by resonance frequency analysis and damping capacity assessment: comparison of both techniques in a clinical trial. int j oral maxillofac implants 2008; 23(3): 525-30. 13. meredith n, alleyne d, cawley p. quantitative determination of the stability of the implant-tissue interface using resonance frequency analysis. clin oral implants res 1996; 7: 261-7. 14. östman po, hellman m, wendelhag i, sennerby l. resonance frequency analysis measurements of implants at placement surgery. int j prosthodont 2006; 19(1): 77-83. 15. farré-pagés n, augé-castro ml, alaejos-algarra f, mareque-bueno j, ferrés-padró e, hernández-alfaro f. relation between bone density and primary implant stability. med oral patol oral cir bucal 2011; 16 (1): e62-7. 16. iezzi g, scarano a, di stefano d, arosio p, ricci l, piattelli a, perrotti v. correlation between the bone density recorded by a computerized implant motor and by a histomorphometric analysis: a preliminary in vitro study on bovine ribs. clin implant dent relat res 2013; doi: 10.1111/cid.12121. 17. misch ce. contemporary implant dentistry. 3rd ed. st. louis: elsevier health sciences; 2008. p.137. table 8: multiple linear regression with average isq (of the two perpendicular measurements, namely bp and md) as the dependent (response) variable and duration of follow up (after 8 weeks of surgery) in addition to age, gender, bone density, implant dimensions and location as explanatory (independent) variables explanatory (independent) variables partial regression coefficient p standardized coefficient (constant) 41.5 <0.001 follow up period (weeks after surgery) 0.5 <0.001 0.502 implant diameter (mm) 5.0 <0.001 0.349 bone density (d4 compared to d3) -3.7 <0.001 0.295 implant arch location (anterior compared to posterior) -3.2 0.003 0.258 implant length (mm) 0.9 0.002 0.237 age (years) -0.1 0.032 0.142 mandibular jaw compared to maxillary jaw 1.6 0.06[ns] 0.137 الخالصة كان الھدف من ھذه الدراسة ھو قیاس . یعتبر ثبات الزرعة واحد من أھم العوامل المؤثرة على الشفاء ونجاح عملیة االندماج العظمي للزرعات السنیة: الخلفیة .لتي تؤثر على ثبات الزرعةعلى فترات خالل فترة الشفاء بوصفھ عامال تنبؤیا لالندماج العظمي، وتحدید العوامل ا isqقیم حاصل ثبات الزرعة وتقع على النحو implantium زرعة سنیة من نوع 44تلقى المرضى .)ذكر 13انثى، 17(ثالثون مریضا تم ادخالھم في الدراسة : المواد وطرق العمل تم تحدید كثافة العظم باستخدام . لجزء الخلفيزرعة في ا 27زرعة في الجزء االمامي و 17زرعة في الفك السفلي منھا 22زرعة في الفك العلوي، 22: التالي تم استخدام تحلیل ). d4زرعة وضعت في 15، و d3 زرعة وضعت في 29(لكثافة العظم mishاالشعة المقطعیة التفاعلیة وتم تصنفیفھا وفقا لتصنیف .بعد عملیة وضع الزرعة السنیة اسبوع 24و 16، 8الترددات الرنینیة للقیاس المباشر لثبات الزرعة في یوم الزراعة وفي ، ثم زاد المتوسط لیصل في االسبوع الرابع )69.5(عند االسبوع الثامن isqكان أدنى متوسط لمعدل ). 73.2(عند الجراحة isqكان متوسط معدل : النتائج بالنسبة للزرعات . الزرعات الموضوعة في الفك العلوي أعلى معنویا بالمقارنة مع isqالزرعات الموضوعة في الفك السفلي أظھرت قیم ).76.8(والعشرون وقد لوحظت عالقة خطیة ایجابیة . أعلى معنویا بالمقارنة مع الزرعات الموضوعة في الجز االمامي isqالموضوعة في الجزء الخلفي من الفك كانت قیم ).r=0.343 p<0.001(ومعنویة بین قطر الزرعة وثبات الزرعة وكانت . تحلیل الترددات الرنینیة أداة تشخیصیة بدون ادخال ادوات الى انسجة الجسم للكشف عن التغیرات في ثبات الزرعة خالل فترة الشفاءكان : االستنتاجات ).الخلفي \الفك السفلي، األمامي \الفك العلوي (العوامل التي أثرت على ثبات الزرعة ھي قطر الزرعة وموضع الزرعة dropbox 2 ban f 9-13.pdf simplify your life dropbox 03 abdalbasit 12-16 .pdf simplify your life dropbox 9 ali f 52-59.pdf simplify your life 404 not found dropbox 08 taghreed 39-45.pdf simplify your life j bagh college dentistry vol. 28(4), december 2016 prevalence of dental expression oral diagnosis 72 prevalence of dental anomalies among iraqi dental students areej a. najm, b.d.s., m.sc. (a) alaa salah mahdi, b.d.s., m.sc. (b) resha j. al-sudani, b.d.s., m.sc. (b) hanadi hekmat musa, b.d.s. (c) abstract background: dental anomalies are abnormal tooth condition occurs due to certain genes or environmental factor disturb tooth development during morphodifferentiation stages, affecting group of teeth or entire dentition. the aim of the study is to evaluate the frequency of occurrence of dental anomalies among dental student. materials and methods: three hundred dental students with age ranged (18-23 years) were examined clinically and radiographically searching for dental anomalies in shape, number and position. results: only 25 students (8.3 %) from the total sample (300) had dental anomalies, female form the higher percentage of anomalies (about 68%) compared to male (32%). the age group (22 years) which was the larger group had a higher percentage of dental anomalies (about 40%). regarding the type of anomalies found, disturbance in number of teeth represent the higher percentage (48%); but impacted third molar represent the most common subtype of positional anomalies found in the study (20%). conclusion: higher percentage of dental anomalies detected in female and larger age group, study of dental anomalies was of great importance especially prior to orthodontic and surgical intervention. key words: dental anomalies, types, prevalence, radiography. (j bagh coll dentistry 2016; 28(4):72-76) introduction dental anomalies are wide range of abnormalities or changes in tooth structure, size, shape, number and eruption pattern in the jaws (1) , they affect both deciduous and permanent dentition (2). genetic and environmental factors happened during different gestational stages were responsible for many types of abnormalities in craniofacial and dentofacial structures (3), so dental anomalies can be classified according to its causative factor into; congenital, developmental and acquired (4), sometimes can be occur in association with systemic disorders or syndrome such as cleft lip and palate or down's syndrome (5). dental anomalies classified into four types by shokri et al. shape, number, position and structure. shape anomalies such as taurodontism (developmental anomaly in which tooth trunk is long and large while the root is short and apically located bifurcation area, occur most frequently in molars) (6), dens invaginatus (anomaly resulting from invagination in the tooth surface appear as a reverse tear in the crown and sometimes in the root, lined by enamel and dentin) (1), dens evaginatus (outward projection of focal area of crown as horn-like protuberance misdiagnosed as (a) lecturer, department of oral diagnosis, college of dentistry, university of baghdad. (b)assistant lecturer, department of oral diagnosis, college of dentistry, university of baghdad. (b)assistant lecturer, department of oral diagnosis, college of dentistry, university of baghdad. (c) dentist, ministry of health. extra cusp) (7), fusion and germination (fused tooth appear as large clinical crown with one or two pulp chamber and two root canals; while the geminated tooth appear as large clinical crown with two pulp chambers and only one pulp canal , both of them occur most frequently in anterior teeth) (8). the second type of dental anomalies was anomalies in number represented by either increase in number of teeth (supernumerary), decrease in number (hypodontia when one to five teeth were missed, and oligodontia when six teeth or more were missed) or complete absence of teeth (anadontia) (9). supernumerary teeth have different types, the most common type was conical tooth or mesiodens which appear as small peg shaped tooth between permanent incisors (10). other types was tuberclate supernumerary which appear as barrel-shape with more than one cusp or tubercle located palatal to central incisors, and its responsible for their delayed eruption (11). positional anomalies included impaction, ectopic eruption and tooth transposition. impaction is the most common one and it's responsible for the most of malocclusion cases and orthodontic patients (12). the most frequently impacted teeth are third molars and maxillary canine (tooth considered to be impacted when it's not erupted within a specific period of time and prevented by adjacent teeth, bone, soft tissue and other conditions (13). structural anomalies such as dentinogenesis imperfecta (autosomal dominant inherited localized mesodermal dysplasia affect both dentitions, clinically the tooth color various from j bagh college dentistry vol. 28(4), december 2016 prevalence of dental expression oral diagnosis 73 brown to blue and radiographically the tooth had bulbous crown with short root resembling shell teeth (14). other type of structural anomalies was amelogenesis imperfecta (genetically heterogeneous condition that affect both quality and quantity of enamel structure) (15). the aim of this study was to evaluate the frequency of occurrence of dental anomalies among dental student. subjects and methods the sample of this study was dental students in college of dentistry/ baghdad university. three hundred students with age ranged from 18-23 years were examined clinically and radiographically from november 2014 to march 2015 searching for certain types of dental anomalies. after obtaining informed consent for their agreement to participate in the study, periapical, occlusal or panoramic radiograph had been taken according to the case examined. the data were collected and statistically analyzed. results in this study 300 dental students were examined, 25 students had dental anomalies, 17 of them were females (68 %) and 8 were males (32%) with age ranged between 18-23 years and the dental anomalies were widely distributed in students with age 22 year (40 %), then (20%) in 18 year, (16%) was found in 21 and 20 years old, and (12%) in 19 years old as shown in table 1. table 1: distribution of study sample according to age age group (years) no. percentage 22 10 40 21 4 16 20 4 16 19 3 12 18 5 20 total 25 100 the study groups were divided into three groups according to type of dental anomalies found, number anomalies 48% (found in 12 students of 25), shape anomalies 28% (found in 7 students of 25) and positional anomalies 24% (found in 6 students of 25) as shown in figure (1). the prevalence of various dental anomalies observed with their percentage in relation to gender was recorded in table 2, and demonstrating that the percentage was higher in females. fig. 1: type of dental anomalies found. table 2: frequency of occurrence of dental anomalies in relation to gender regarding positional anomalies, impacted third molar represent the most frequently observed cases (5 of total 6), while impacted canine found only in one student ( as shown in table 3, fig. 2 and 3). regarding number of teeth anomalies, the most frequent cases were congenitally missing lower second premolar (4 cases of total 12 case of number anomalies), followed by supernumerary and mesiodens (3 cases), and congenitally missing lateral incisors (2 cases for upper and 2 cases for lower). the least one was congenitally missing upper second premolar (1 case only) as shown in fig. 4, 5 and 6. regarding shape anomalies, the most frequent cases observed were peg shape lateral incisors (4 cases of total 7) as shown in fig 7, followed by dens evaginatous (2 cases) and finally one case of taurodontism. number anomalies 48% shape anomalies 28% positional anomalies 24% type of dental anomalies types male female total pvalue n % n % n % number anomalies 3 12 9 36 12 48 p<0.05 shape anomalies 2 8 5 20 7 28 positional anomalies 3 12 3 12 6 24 total 8 32 17 68 25 100 j bagh college dentistry vol. 28(4), december 2016 prevalence of dental expression oral diagnosis 74 table 3: frequency of occurrence of various dental anomalies type of dental anomalies n % p-value number anomalies congenital missing lower second premolar 4 16 p> 0.05 congenital missing upper second premolar 1 4 congenital missing lower lateral incisor 2 8 congenital missing upper lateral incisor 2 8 mesiodens and supernumerary tooth 3 12 total 12 48 shape anomalies peg shape lateral incisor 4 16 p> 0.05 dens evaginatous 2 8 taurodontism 1 4 total 7 28 positional anomalies impacted third molar 5 20 p> 0.05 impacted canine 1 4 total 6 24 figure 2: impacted upper third molar in panoramic radiograph figure 3: impacted upper canine in panoramic radiograph figure 4: congenital missing lower second premolar in panoramic radiograph figure 5: congenital missing lower lateral incisor. figure 6: supernumerary tooth in lower anterior region. figure 7: peg shaped lateral incisor. j bagh college dentistry vol. 28(4), december 2016 prevalence of dental expression oral diagnosis 75 discussion the present study was conducted on 300 dental students searching for dental anomalies. the results shows that 25 student had dental anomalies of different types. the results of this study showed that female had higher percentage (68%) of dental anomalies compared to male (32%), this is agreed with guttal et al. (2), afify and zawawi (12), and nemati et al. (16) and disagreed with sener et al. (17) and atoche et al. (18), who showed no relation between dental anomalies and gender, also vani et al. (19), who found equal distribution of dental anomalies among gender. in the current study, number anomalies represent the highest percentage of dental anomalies (48%), while garrib et al. (20) found that structural anomalies represent the highest percent among other dental anomalies, and gupta et al. (21) reported that rotation was the most common dental anomalies followed by ectopic eruption, and the least one was number anomalies, this differences may be due to not including of structural anomalies, rotation and ectopic eruption in the current study in addition to different racial groups. the most common dental anomalies found in this study was number anomalies (48%), followed by shape anomalies (28%), while shetty et al. (22) found that shape anomalies was most prevalent than other anomalies followed by number anomalies. this difference may be due to different sample size and types of anomalies found. regarding positional anomalies, the current study showed that most prevalent positional anomalies was impaction, 20% for impacted third molar followed by impaction of canine 4%, this result agreed with ackam et al. (3) who reported a percentage of 3% for impacted canine, also the results confirmed by afify and zawawi (12) who reported a percentage of 21.1 % for impaction, also the results agreed with kathariya et al. (23) and haugland et al. (24) the results of this study were agreed with shokri et al. (6) reported that positional and number dental anomalies were the most prevalent, impaction and hypodontia were the most common subtypes of dental anomalies, in this study number anomalies was the most prevalent with most common subtypes of congenital missing lower second premolar, followed by positional anomalies with high percentage of impacted third molar (20%). regarding shape anomalies, the results showed a high percentage of peg shaped lateral incisors about 16%, followed by dens evaginatus 8%, and 4% taurodontism. this was confirmed by the results of shetty et al. (22) who reported that anterior area of maxilla especially lateral incisors had a high incidence of dental anomalies. on other hand, the results were not in conformity with those reported by darwazeh et al. (5) and ackam et al. (3). the differences may be due to difference sample type (cleft patients), sample size and races. in conclusions; 1. female had higher percentage of dental anomalies compared to male. 2. dental anomalies become more recognizable with increased age. 3. number anomalies represent the highest percentage compared to positional and shape anomalies. references 1. neville dw, damm dd, allen cm, bouquot je. abnormalities of teeth. in: oral and maxillofacial pathology. 2nd ed. philadelphia: elsevier; 2005. pp. 4989. 2. guttal ks, naikmasurb vg, bhargavac p, bathid rj. frequency of developmental dental anomalies in the indian population. eur j dentistry 2010; 14: 263-96. 3. ackam mo, evirgen s, ulsu o, memikoglu uk. dental anomalies in individuals with cleft lip and/or palate. eur j orthod 2010; 32: 207-13. 4. white sc, pharoah mj. oral radiology: principles and interpretation. 6th ed. st. louis: mosby elesiver; 2009. 5. darwazeh am, hamasha aa, pillai k. prevalence of taurodontism in jordanian dental patients. dentomaxillofacial radiol 1998; 27:163-5. 6. shokri aj, khajeh s, faramarzi f, kahnamoui hm. prevalence of dental anomalies among 7 to 35 years old people in hamadan, iran in 20122013 as observed using panoramic radiograph. imaging sci dent 2014; 44(1): 7-13. 7. vasudev sk, goel br. endodontic management of dens evaginatus of maxillary central incisors: a rare case report. j endod 2005; 31: 67-70. 8. indra r, srinivasan mr, farzana h, karthikeyan k. endodontic management of fused maxillary lateral incisors with supernumerary tooth: a case report. j endod 2006; 32: 12-17. 9. peker i, kaya e, darendeliler s. clinical and radiographical evaluation of non-syndromic hypodontia and hyperdontia in permanent dentition. med oral patol oral cir bucal 2009; 14: 393-7. 10. mitchell l. an introduction to orthodontics. 1st ed. oxford: oxford university press; 1996. pp. 23-5. 11. foster td, tylor gs. characteristics of supernumerary teeth in the upper central incisor region. dent pract dent rec 1969; 20: 8-12. 12. afify ar, zawawi kh. the prevalence of dental anomalies in the western region of saudi arabia. isrn dentistry 2012; 1-5. 13. al-nimri k, gharaibeh t. space conditions and dental and occlusal features in patients with palatally impacted maxillary canines: an etiological study. eur j orthod 2005; 27: 461-5 14. witkop cj, rao s. inherited defect in tooth structure. birth defects orig artic ser 1971; 7(7): 153-84. j bagh college dentistry vol. 28(4), december 2016 prevalence of dental expression oral diagnosis 76 15. aldred mj, savariryana r, crawford pj. amelogenesis imperfect: a classification and catalogue for 21st century. oral dis 2003; 9: 19-23. 16. nemati s, dalili z, dolatabadi n, javadzadeh as. prevalence of developmental and acquired dental anomalies on digital panoramic radiography in patients attending the dental faculty of rasht, iran. j dentomaxillofac radiol path surg 2012; 1(2): 24–31. 17. şener s, ünlü n, bozdağ g. presence, distribution and association of dental anomalies: a clinical and radiographical study. clinical dentistry res 2011; 35(3): 43-52. 18. atoche jr, morales sd, ruiz gc. prevalence of dental anomalies in a mexican population. dentistry j 2014; 2(1): 77-86. 19. vani nv, saleh sm, tubaigy fm, idris am. prevalence of developmental dental anomalies among adult population. saudi j dental res 2016; 7(1): 2933. 20. garrib dg, alencer bm, ferreira fv, ozawa to. associated dental anomalies: the orthodontist decorating the genetic which regulate the dental developmental disturbances. den. press j ortho 2010; 15(2): 138-57. 21. gupta sk, saxena p, jain s, jain d. prevalence and distribution of selected developmental anomalies in the indian population. j oral sci 2011; 53(2): 231-8. 22. shetty a, rai k, hegde a. incisal abnormalities in children with unilateral cleft lip and palate. sch j app med sci 2013; 1(4): 233-5. 23. kathariya md, nikam ap, chopra k, patil nn, hitesh r, kathriya r. prevalence of dental anomalies among school going children in india. j int oral health 2013; 5(5): 10-4. 24. haugland l, storesund t, vandevska v. prevalence of dental anomalies in norwegian school children. j stomatol 2013; 3: 329-33. dropbox 3 maha s f 14-18.pdf simplify your life dropbox 04 elaf 17-22.pdf simplify your life j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 80 enhancement of tooth eruption by using amniotic stem cells (immunohistochemical study of vegf marker) athraa y. alhijazi, b.d.s., m.sc., ph.d. (1) lubna k. jassim, b.d.s., m.sc. (2) abstract background: tooth eruption is a localized process in the jaws which exhibits precise timing and bilateral symmetry. develop within the jaws and their eruption is a complex infancy process during which they move through bone to their functional positions within the oral cavity. for species with more than one set of teeth, eruption of the second set also accomplishes. the key to the successful clinical management of tooth eruption consists of understanding that this process consists largely of the local regulation of alveolar bone metabolism to produce bone resorption in the direction of eruption and shift and formation of bone at the opposite side.the amniotic sac contains a considerable quantity of stem cells. these amniotic stem cells are able to differentiate into various tissues, which used in many field. vascular endothelial growth factor (vegf) is an important angiogenic factor reported to induce migration and proliferation of endothelial cells, enhance vascular permeability, and modulate thrombogenicity. vegf expression in cultured cells (smooth muscle cells, macrophages, endothelial cells) is controlled by growth factors and cytokines. the aim of this study was to study the administration of cell molecules of (chorion, amnion and amniotic fluid) around developing mouse tooth and studying the expression of vegf marker. materials and methods: forty eight albino swiss mice of one day old age injected with isolated amniotic stem cells in the anterior region of maxilla (incisors area) other 16 mice injected with saline represents control. sacrifice 4 mice for each period (4, 7, 10, and 13) day old age. the result were studied histologically and immunohistochemistry. results: vegf marker localized and identified in 3 areas; pulp, p.d.l, and bone. in pulp. the mean value of positive vegf expression showed to be highest in amnion group in comparison to the other studied groups. the marginal mean value of all periods reported to be highest in amnion groups followed by chorion group. the period 10 day showed highest marginal means value for positive vegf expression for all groups. in p.d.l. area amniotic fluid records the highest mean and marginal mean value specifically at day-10 in comparison to other studied groups. in bone area amniotic fluid records the highest mean and marginal mean value among the studied groups followed by chorion group. period 7-day and 10-day shows high mean value for vegf expression. coincidence test for vegf marker illustrates to be affected by amniotic fluid application in p.d.l. and in bone area while amnion and chorion application showed to be concerned with pulp. conclusion. it reported that amniotic fluid application affected on expression of vegf in p.d.l and bone while amnion and chorion showed to affect on expression of vegf in pulp.the present study highlighted on clinical and researcher application of amniotic fluid and chorion for supplement of stem cell in dental tissue engineering or even in other body tissues. keywords: tooth eruption, amniotic stem cells, immunohistochemical study, vegf marker. (j bagh coll dentistry 2013; 25(2):80-88). introduction amniotic stem cells are multipotent stem cells of mesenchymal origin extracted from amniotic fluid; it can be transformed into a more versatile state similar to embryonic stem cells, that they can revert to being pluripotent just by adding a chemical reagent that modifies the configuration of the dna so that genes that are expressed in the embryo get switched back on (1). amniotic stem cells are able to differentiate into various tissue types such as skin, cartilage, cardiac tissue, nerves, muscle, and bone, and may have potential future medical applications (2). the deployment of amniotic fluid af-derived stem cells (afs) for tissue regeneration offers advantages over the use of embryonic or adult stem cells (3) (1)msc student, department of oral diagnosis, college of dentistry, university of baghdad. (2)professor. department of oral diagnosis, college of dentistry, university of baghdad. vegf is a sub-family of growth factors, specifically the platelet-derived growth factor family of cystine-knot growth factors. they are important signaling proteins involved in both vasculogenesis (formation of the embryonic circulatory system) and angiogenesis (the growth of blood vessels from pre-existing vasculature (4). its normal function is to create new blood vessels during embryonic development, new blood vessels after injury, and new vessels (collateral circulation) to bypass blocked vessels(5) . materials and methods seventy nine albino swiss female mice were used in the present study. those mice were divided into 3 main groups: 1. experimental group: consisted of 16 mice of one day old of age injected with isolated amniotic stem cells in the anterior region of maxilla (incisors area). sacrifice 4 mice for each period (4, 7, 10, and 13) day old age. those 16 http://en.wikipedia.org/wiki/amniotic_stem_cell http://www.news-medical.net/health/angiogenesis-what-is-angiogenesis.aspx j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 81 mice injected with amnionic cells, 4mice for each scarifying periods. 2. control group: consists of 16 mice of one day old age, injected with normal saline in the anterior incisors region of maxilla. sacrifice 4 mice for each period (4, 7, 10, and 13) day. 3. pregnant mice group: consists of 15 pregnant mice: 5 out of 15 were used to collect their autologous amniotic fluid at (13 day of gestation period), and stored to be used to their neonatal embryo. while other 10 pregnant mice were scarified to obtain amnionic and chorionic cells from their placenta at (17 day of gestation period). collection of amniotic fluid amniotic fluid was collected from each 5 pregnant mice at 13 day of gestation period (separately) , by using needle aspiration technique, cleaned their skin and wiped with alcohol, then aspirate the fluid using insulin syringe and preserved the amniotic fluid in sterile tube at -80°c until it used. isolation amniotic stem cells from the placenta samples were obtained from 10 pregnant mice at 17 day gestation period to isolate chorion and amnion, after sacrifice the pregnant mice by over dose anesthesia, the embryos inside amniotic membrane with their placenta will excluded immediately. then isolate the embryo from the placenta, and carrying the following procedures: 1. the placenta was cleaned from blood clot with a sterile phosphate-buffered saline solution. 2. removing of amniotic membrane from embryos and put in flask. 3. take a pair of sterile scissors and carefully cut the outside epithelial layer off. the more cut the more stem cells get. the amnion layer is mechanically peeled off the chorion. 4. washing the amnion in phosphate buffered saline solution (pbs) in several times (8-10x) to remove blood. 5. mince the tissue thoroughly with a pair of another sterile scissors. 6. to release amniotic epithelial cells, incubate the minced amnion membrane with trypsin (0.05%) for 10 minutes at 37°c. 7. treating the remaining tissue in another tube of trypsin (0.05%) for 20 minutes at 37 °. 8. pooling the cells from the digests. 9. fuge the filtered cell suspension for 8 minutes at 1200 rpm. 10. washing the cell pellet with pbs and fuge again. 11. counting the cells with a hemocytometer and it is advisable to determine the viability of the cells by exclusion of trypan blue dye, 12. resuspending the pellet in freezing medium by pipetting gently. 13. in order to freeze the cells gradually and safe, place the ampoules in -60°c or less and leave them there for 16-24 hours(6). (all operation was done under sterile condition, using a laminar flow hood. monoclonal antibodies cd34 and their detection kit. monoclonal antibody v2110-18t3 (rabbit anti-mouse): us biological vegf receptor 2 (vegfr2). immunohistochemistry with detection kit, hrp, mouse tissue, bioassaytm, us biological, ihc detection kit, hrp, mouse primaries (catalog no.17506-06). results histological and immunohistological tests for detection the expression of vegf marker were performed on both experimental and control groups for all periods. view of pulp for control group of mouse 13 days old shows positive expression of vegf in the endothelial cell of blood vessels; they show strong dabstain (fig. 1). immunohistochemical examination for pulp of mouse 13 days old treated with amnion illustrate positive staining for vegf (fig.2). fig. 3&4 show positive expression of vegf in the mesenchymal cell of pulp, dental sac and in new formed bone around tooth of mouse 13 days old treated with chorion. endothelial cell of blood vessels in pulp of tooth of mouse treated with amniotic fluid shows positive expression of vegf (fig. 5), while (fig.6 &7) illustrate the expression of vegf in dental sac area with angiogenesis. http://www.ruf.rice.edu/~bioslabs/methods/microscopy/cellcounting.html http://www.bio.com/protocolstools/protocol.jhtml?id=p2151#procedure j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 82 0 figure 1: view for pulp of (control) tooth mouse 4 days old shows positive vegf (arrow). dab stain with counter stain hematoxylin, x200 figure 2: positive vegf demonstrated in pulp of tooth mouse 4 days old treated with amnion. dab stain with counter stain hematoxylin, x20 figure 3: positive vegf view in endothelial cell (arrow) and in the mesenchymal cell (mc) of pulp in tooth mouse 4 days old treated with chorion.dab stain with counter stain hematoxylin,x200 figure 4: positive vegf demonstrated in dental sac area and in resorbed bone area (arrow).dab stain with counter stain hematoxylin, x200 j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 83 at 7 days old mouse view of positive vegf for stromal cell in new bone formed in maxilla of tooth mouse control group (fig.8).immunohistochemical view of mouse treated with amnion shows positive vegf expression of endothelial cells (fig 9). fig. (10&11) shows positive expression of vegf in endothelial cells and stromal cells of new bone formed and in periodontal ligament of tooth of mouse treated with chorion.while with amniotic fluid shows positive vegf expression of endothelial cell, mesenchymal cell and dental sac tissue. figure (12&13). figure 5: positive expression of vegf by endothelial cells of blood vessels in pulp of 4 days old mouse treated with amniotic fluid (arrow). dab stain with counter stain hematoxylin, x400 figure 6: positive vegf in dental sac area (arrow) for previous figure (3-93). dab stain with counter stain hematoxylin, x200. figure 7: angiogenesis view showing positive vegf in dental sac of tooth mouse 4 days old treated with amniotic fluid. dab stain with counter stain hematoxylin, x400 j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 84 figure 8: stromal cell of new bone shows positive vegf expression (arrow) of 7 days old mouse control. dab stain with counter stain hematoxylin, x400 figure 9: pulp tissue of tooth germ (7 days old mouse) treated with amnion, shows positive vegf expression of endothelial cell (arrow). dab stain with counter stain hematoxylin, x100 figure 10: vegf positive expressed by stromal cell in overlying bone (arrow) of tooth germ 7 days old mouse treated with chorion. dab stain with counter stain hematoxylin, x200 figure 11: lateral side view for periodontal ligament, and new bone formation of tooth germ of 7 days old mouse treated with chorion, shows positive vegf expression of endothelial cell (arrow). dab stain with counter stain hematoxylin, x100 j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 85 at 10 days old mouse control group: immunohistochemical localization for vegf in endothelial blood vessels, pulp, and dental sac figure (14). section in pulp of tooth of mouse 10 days old treated with amnion illustrate positive vegf expression in endothelial cells of blood vessels figure( 15). in the apical area, vegf marker localized in stromal cells between the bone figure (16). microphotograph view illustrate expression of vegf in endothelial cells of blood vessels in both of pulp and dental sac of tooth of mouse 10 days old treated with chorion. figure (17&18). pulp of tooth treated with amniotic fluid shows positive expression of vegf on endothelial blood vessels, new blood vessels and mesenchymal cell figure (19). the apical portion shows positive vegf expression on proliferative dental sac area represented by periodontal ligament (p.d.l) and new bone formation area figure (20). figure 12: pulp tissue of tooth germ (7 days old mouse) treated with amniotic fluid shows positive vegf expression of endothelial cell and mesenchymal cell (arrow). dab stain with counter stain hematoxylin, x400 figure 13: dental sac tissue of tooth germ of treated 7 days old mouse with amniotic fluid shows positive vegf expression (arrow). dab stain with counter stain hematoxylin, x200 j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 86 figure 14: immunohistochemical positive vegf expressed in pulp, dental sac and endothelial blood vessels (arrow), of tooth germ mouse 10 days old control. dab stain with counter stain hematoxylin, x100 figure 15: view for endothelial blood vessels expressed positive vegf (arrow), section in pulp of tooth mouse 10 days old treated with amnion dab stain with counter stain hematoxylin, x400 figure 16: view for the bone formation area (apically) showing positive (vegf) marker demonstrated in stromal cell (arrow). dab stain with counter stain hematoxylin, x400 figure 17: immunohistochemical positive vegf view expressed in endothelial cell (arrow) of blood vessels in pulp of tooth germ mouse 10 days old chorion . dab stain with counter stain hematoxylin, x400 j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 87 discussion the vascular endothelial growth factor (vegf) is considered the most important gf controlling the vascular responses in the body. it is a mitogen for endothelial cells, and its expression is related to the phenomenon of angiogenesis. the present study illustrates positive vegf in pulp, p.d.l and in bone in studied groups. although all studied groups shows positive expression of vegf, amnion figure 18: other view for previous figure (3105), showing positive vegf in the endothelial cell of blood vessels in the dental sac. dab stain with counter stain hematoxylin, x400 figure 19: positive expression of vegf on endothelial cells (ec) of blood vessels in pulp, proliferative new blood vessels (arrow), even mesenchymal cell (mc). view of tooth germ of 10 days old mouse treated with amniotic fluid. dab stain with counter stain hematoxylin,x400 figure 20: view of apical portion of previous figure (3-107) shows positive vegf expression on proliferative dental sac area represented by periodontal ligament (p.d.l) and new bone formation area (arrow). dab stain with counter stain hematoxylin, x200 j bagh college dentistry vol. 25(2), june 2013 enhancement of tooth oral diagnosis 88 group illustrates high difference value at 4 day in comparison to others. it can be explained that the dentin-pulp matrix is rich in growth factors (gfs) that, when diluted and diffused into the pulp tissue, aid the healing process. the angiogenic gfs participate in this event. vascular endothelial growth factor (vegf), a potent mitogen for endothelial cells, promotes endothelial cell survival and enhance new blood vessels formation. amniotic fluid group records the highest value for positive vegf in p.d.l and in bone areas at day 10 in comparison to the others. the present result coincide with kaku et al (7) who investigated whether recombinant human vegf (rhvegf) stimulated osteoclast differentiation during experimental tooth movement. for coincidence test of expression marker vegf, it reported that amniotic fluid application affected on expression of vegf in p.d.l and bone while amnion and chorion showed to affect on expression of vegf in pulp. it seems that amnion and chorion affects the undifferentiated mesenchymal cell in pulp and enhances it or it may act as progenitor cell and differentiated to endothelial positive vegf cells references 1. walther g, gekas j, bertrand of. amniotic stem cells for cellular cardiomyoplasty: promises and premises. catheter cardiovasc interv 2009; 73(7): 917-24. 2. siegel n, rosner m, hanneder m, freilinger a, hengstschlager m. human amniotic fluid stem cells: a new perspective. amino acids 2008; 35(2): 291-3. 3. klemmt pa, vafaizadeh v, groner b. the potential of amniotic fluid stem cells for cellular therapy and tissue engineering. expert opin biol ther 2011; 11(10):1297-314. 4. mastrangelo f, piccirilli m, dolci m, teté s, speranza l, patruno a, gizzi f, felaco m, artese l, de lutiis ma. vascular endothelial growth factor (vegf) in human tooth germ center. int j immunopathol pharmacol 2005; 18(3):587-94. 5. anna-karin olsson, anna dimberg, johan kreuger and lena claesson-welsh. vegf receptor signalingin control of vascular function. nat rev mol cell biol 2006; 7: 359-71. 6. attilacsordas. tierneylab: new science blog hosted by the new york times. how to isolate amniotic stem cells from the placenta, at home! posted by on january 23, 2007, boingboing. 7. kaku m, kohno s, kawata t, maeda n, tanne k. effects of vascular endothelial growth factor on osteoclast induction during tooth movement in mice. jdr 2001; 80:1880-3. http://www.ncbi.nlm.nih.gov/pubmed?term=klemmt%20pa%5bauthor%5d&cauthor=true&cauthor_uid=21623704 http://www.ncbi.nlm.nih.gov/pubmed?term=vafaizadeh%20v%5bauthor%5d&cauthor=true&cauthor_uid=21623704 http://www.ncbi.nlm.nih.gov/pubmed?term=groner%20b%5bauthor%5d&cauthor=true&cauthor_uid=21623704 http://www.ncbi.nlm.nih.gov/pubmed/21623704 http://www.ncbi.nlm.nih.gov/pubmed?term=%22mastrangelo%20f%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22piccirilli%20m%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22dolci%20m%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22tet%c3%a9%20s%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22speranza%20l%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22patruno%20a%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22gizzi%20f%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22felaco%20m%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22artese%20l%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed?term=%22de%20lutiis%20ma%22%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed/16164840 http://www.ncbi.nlm.nih.gov/pubmed/16164840 http://pimm.wordpress.com/ http://pimm.wordpress.com/2007/01/22/tierneylab-new-science-blog-hosted-by-the-new-york-times/ http://pimm.wordpress.com/2007/01/22/tierneylab-new-science-blog-hosted-by-the-new-york-times/ http://www.boingboing.net/2007/01/23/how_to_isolate_stem_.html rana f.doc j bagh college dentistry vol. 25(3), september 2013 assessment of the oral diagnosis 88 88 determination of the effect of stress on the salivary cortisol level among sample of university students having myofacial pain rana m. hasan, b.d.s. (1) jamal n. ahmed, b.d.s., m.sc., ph.d. (2) abstract background: psychological stress is considered the major etiological factor precipitating myofacial pain and temporomandibular disorders.it is known that stress induce various adaptational responses of physiologic systems. the process includes increase in the activity of the hypothalamic -pituitary-adrenal axis which promotes cortisol secretion. salivary cortisol has been used as a measure of free circulating cortisol levels.the use of salivary biomarkers has gained increased popularity since collecting samples is non-invasive and painless. the aim of thisstudy was to evaluate the level of cortisol in saliva among sample of university students having myofacial pain, during the final exam period and whether this finding could have a significant value as a symptomatic psychobiological marker. materials and methods: ninety eight (98) university students were enrolled in this study. fifty(50) were with myofacial pain (symptomatic) and forty eight (48) were without myofacial pain (asymptomatic) as a control group.each student with myofacial pain was examined according to research diagnostic criteria for temporomandibular disorders. saliva sample were collected from each subject before final examination and three months later for biochemical analysis of cortisolusing elisa test. results: a highly significant difference in salivary cortisol level between the two periods for both the study and control groups, and a non-significant difference between the two groups in before examination period. a negative association has been observed between the level of salivary cortisol and severity of pain and a highly significant improvement of pain between the final examination periods and three months later. conclusions: dental students perceived a higher level of stress prior to the final exam was associated with raised salivary cortisol levels which could be considered as a useful non-invasive biomarker for measuring acute stress. keywords: stress, cortisol, myofacial pain. (j bagh coll dentistry 2013; 25(3):87-90). introduction psychological factors, such as stress, were considered to play a major roles in the etiology, progression, and complications of temporomandibular disorders (tmds).1 it has been reported that approximately 50% of all tmds are myogenic in origin.2 myofacial pain of the masticatory muscles is more frequently induced by stress. in addition, it has been reported that parafunctional habits (i.e. clenching and grinding) is stress-related and replication of research forthe most common forms of muscle and joint-related disorders.3 academic examinations are considered as one of the most acute stressors experienced by students. acute stress has been reported to increase the activity of the hypothalamus-pituitary adrenal (hpa) axis with subsequent rise in cortisol level. 4, 5 in the blood only 1 to 15% of cortisol is in its unbound or biologically active form. the remaining cortisol is bound to serum proteins.6 (1) master student, department of oral diagnosis, college of dentistry university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry university of baghdad. unbound serum cortisol enters the saliva via intracellular mechanisms, and in saliva the majority of cortisol remains unbound to protein, because of partial conversion of cortisol to cortisone during passage through the salivary glands, the absolute level of free cortisol in saliva is 10% to 35% lower than it is in blood.7 the use of salivary biomarkers has gained increased popularity over the past decade in psychological and biomedical research since collecting samples is non-invasive and painless.8 salivary cortisol measurement is today a widely accepted as alternative to plasma or serum measurement, since. salivary cortisol has been used as a measure of free circulating cortisol levels. in addition, the adrenal cortex is responsive to stress because venipuncture for blood collection can lead to an iatrogenic increase of plasma glucocorticoid levels.9the aim of this study was to evaluate the level of cortisol in saliva among sample ofuniversity students havingsymptom of myofacial pain during the final exam period and whether this finding could have a significant value as a psychobiological stress marker. materials and methods the study was conducted in baghdad university colleges. the study samples consist of ninety eight university students aged ranged between 18 to 30 years old. they were divided into two 87 j bagh college dentistry vol. 25(3), september 2013 determination of the oral diagnosis 89 88 groups. the 1st group was fifty students with myofacial pain as a study group and the 2nd was forty eight students without myofacial pain as a control group. myofacial pain evaluated according to rdc/tmd. the diagnosis of muscular disorders was basedon the anamnestic reports of pain in the muscles of mastication and clinical assessments of pain by palpation of at least three of twenty muscular sites in the facial area (ten for each side).3 five ml of unstimulated salivary samples were collected from each student in the morning between 7-9am of the day of final examination before entering the exam and second sample were collected three months later for comparison. measurement of salivary cortisol was done by means of high sensitivity, salivary cortisol enzyme immunoassay kit (salimetrics europe, ltd.). results it has been shown that the mean level of salivary cortisol for the study group before exam was (1.988+0.068 μg/dl) and three months later was (0.377+0.245 μg/dl) whereas the mean for the control group before exam was (1.985+0.060 μg/dl) and after three months later was (0.416+0.234 μg/dl) as shown in table (1). testing the similarity between the concentration of salivary cortisol for the study and control groups in the before exam period has shown a non-significant results (p>0.05), as shown in table (2). while testing the alteration in the concentration of salivary cortisol between the two periods (before exam and three months later) for each group has shown a highly significant result (p<0.001), as shown in table (3). the correlation between salivary cortisol concentration and pain is shown in table (4). the correlation coefficient between the concentration of salivary cortisol and pain by scoring (improvement) was (r = -0.353) with significant association at p<0.05 (p=0.021), which indicating that with increasing the concentration grade, decreasing with scoring pain also the correlation coefficient for concentration-differences (before & after) and pain scoring differences was negative (-0.245) and significant at p<0.05 (0.043) as shown in table (5) and figure (1). discussion the students perceive a high level of stress before the final written examinations. the authors were thought to utilize this period as stressful factor to design and conductthis trial. myofacial pain is a symptom usually precipitated by stress and is usually noticed aggravated during the exams period among the university students. it has been proven that stress exaggerated cortisol response; therefore saliva cortisol level was used as a biomarker to determine the myofacial pain precipitated by stress symptom. in thistrial the level of salivary cortisol, which was used as a marker of stress, was found to be non-significant between the study and control groups in the before exam period. however, there was a highly significant difference in both the study and control groups before the exam period compared with its level three months later. this finding is in consistent with other reported studies (8, 10,11). the acute stress has been reported to increase the activity of the hypothalamus-pituitary adrenal (hpa) axis. the activation of the hypothalamic-pituitary-adrenal (hpa) axis and subsequent release of cortisol are major components of the physiological stress response. salivary cortisol accurately reflects serum cortisol, the physiologically active component.4while this findingdisagreed with loft et al. and takatsuji et al. who suggested that salivary cortisol may not be sensitive to the examination stressor.12, 13 in the present study, there was a highly significant differencein the degree orreduction in severity of pain between the two periods. this may be interpreted by the removal of stressor and decreasing of the parafunctional activities. although some participants still had pain but with less score, this may be explained due to stressors of their social lifewhich is in agreement with suvinen et al. who suggested that patients with tmds often have onset of their symptoms during periods of psychological stress (i.e., anxiety) and exacerbation of symptoms during periods of stressful situations.14 as mentioned before the results revealed a high significant difference in salivary cortisol level between the two periods for the study and control group, but a non-significant difference between the two groups in before final examination period.a negative significant association was observed in the study between the concentration of salivary cortisol and pain, this result may be explained by the fight or flight response, was identified by cannon, which is the physiological changes that prepared the body to acute stressor either physical or psychological.15 the stress response is mediated by the activation of both the sympathetic nervous system and the hypothalamic-adrenal-pituitary axis. many hormones are released, cortisol is one of them which have many functions, and one of them is j bagh college dentistry vol. 25(3), september 2013 determination of the oral diagnosis 90 88 the shutting down of the initial fight or flight responses of the sympathetic nervous and immune systems to prevent them from overshooting and damaging the organism.16 during the stress response, both the brain and the pituitary gland release opiates such as endorphins and enkephalins which limit pain perception and their initial function may be primarily to inhibit or modulate the release of cortisol.17, 18 although there is strong evidence that some tmds patients are characterized by higher levels of general anxiety, compared with asymptomatic controls, the influence of stress on tmds is probably not as simple as suggested according to laskin’s theory, in which stress evokes chronic recurrent muscular hyperactivity. and research findings have supported a relationship between anxiety, muscular tension, and tmds symptoms.19the result showed that salivary cortisol level was reduced between the stressful or exam period and three months later, however the level was not different between the myofacial (symptomatic) and control (asymptomatic) group, therefore, this study concluded that salivary cortisol level may be used as a stress marker but not at the level as a stress related myofacial pain symptom indicator. references 1. kanehira h, agarguchi a, kato h, yoshimine s, inoue h. association between stress and temporomandibular disorders. j jpn prosthodont soc 2008; 52: 375-80. 2. stohler cs. masticatory mylagias. in fonseca rj et al (eds). oral and maxillofacial surgery. temporomandibular disorders. philadelphia: wb saunders; 2000. pp. 38-45. 3. dworkin sf, leresche l. research diagnostic criteria for temporomandibular disorders: review, criteria, examinations and specifications, critique. j craniomand dis facial oral pain 1992; 6: 301–55. 4. kirschbaum c, hellhammer dh. salivary cortisol in psy-choneuroendocrine research: recent developments and applications. psychoneuroendocrinology 1994; 194: 313–33. 5. lacey k, zaharia md, griffiths j, ravindran av, merali z, anisman h. a prospective study of neuroendocrine and immune alterations associated with the stress of an oral academic examination among graduate students. psychoneuroendocrinology 2000; 25: 339-56. 6. robin p, predine j, milgrom e. assay of unbound cortisol in plasma. j clin endocrinol metab 1977; 46: 277-83. 7. vining rf, mcginley ra, symons rg. hormones in saliva: mode of entry and consequent implications for clinical interpretation. clin chem 1983; 29: 1752-6. 8. ng v, koh d, mok by, chia se, lim lp. salivary biomarkers associated with academic assessment stress among dental undergraduates. j dent educ 2003; 67(10):1091-4. 9. groschl m, wagner r, rauh m, dörr hg. stability of salivary steroids: the influences of storage, food and dental care. steroids 2001; 66: 737–41. 10. murphy l, denis r, ward chp, tartar jl. academic stress differentially influences perceived stress, salivary cortisol and immunoglobulin-a in undergraduate students. stress j 2010; 13(4): 366-71. 11. pani s, al askar am, al mohaij si, al-ohali ta. evaluation of stress in final year saudi dental students using salivarycortisole as a biomarker. j dental education 2011; 75(3): 377-84. 12. loft p, thomas mg, petrie k.j, booth rj, miles j, vedhara k. examination stress results in altered cardiovascular responces to acute challenge and lower cortisol. psychoneuroendocrinology 2007; 32: 367-75. 13. takatsuji k, sugimoto y, ishizaki s, ozaki y, matsuyama e, yamaguchi y. the effects of examination stress on salivary cortisol, immunoglobulin a, and chromagranin a in nursing students. j biomedical research 2008: 29(4): 221-4. 14. suvinen ti, hanes kr, reade pc. outcome of therapy in the conservative management of temporomandibular pain dysfunction disorder.j oral rehabil 1997; 24: 718-24. 15. cannon wb. bodily changes in pain, hunger, fear and range. new york: appleton press; 1929. 16. munck a. corticosteroids and stress. in fink g (ed). encyclopedia of stress. new york: academic press; 2000. pp. 570-7. 17. chrousos gp. regulation and dysregulation of the hypothalamic-pituitary-adrenal axis. endocrinology metabolism. clinics north america 1992; 21:833-58. 18. sapolsky rm. neuroendocrinology of the stress response. in becker jb, breedlove sm (eds) behavioral endocrinology. cambridge, ma: mit press; 1992. pp. 278-324. 19. fricton jr. masticatory myofascial pain: an explanatory model integrating clinical, epidemiological and basic science research. bull group int rech sci stomatol odontol 1999; 41:14–25. table 1. predicated statistics of concentration of salivary cortisol sample period no. mean s.d. s.e. study before 50 1.988 0.068 0.010 after 50 0.377 0.245 0.035 control before 48 1.985 0.060 0.009 after 48 0.416 0.234 0.034 89 j bagh college dentistry vol. 25(3), september 2013 determination of the oral diagnosis 91 88 concentraion diff. 1.21.0.8.6.4.20.0-.2 p ai n d iff . 6 5 4 3 2 1 0 -1 observed linear figure 1. linear plot for concentration-differences (before & after) and pain scoring differences table 2. testing of similarity between the two independent groups (study and control) at the predicated concentration of salivary cortisol parameter in the before exam period of time parameter levene's test for equality of variances t-test for equality of means f sig. t d.f. sig. c.s. (2-tailed) concentration 0.036 0.851 0.232 96 0. 817 ns table 3. testing of improvement between the two dependent periods (before – after) for each group (study and control) for the predicated concentration of salivary cortisol parameter wilcoxon signed ranks test after – before study control z-test -6.154 -6.031 asymp. sig. (2-tailed) 0.000 0.000 c.s. hs hs table 4. the correlation between the concentration of salivary cortisol and pain scoring correlation between salivary cortisol and pain scoring correlation coefficient p-value -0.353 0.021 table 5. linear person's correlation coefficient for concentration-differences (before & after) and pain scoring differences (*) sig. at p<0.05 person correlation coefficient pain diff. c.s.(*) pain diff. correlation -0.245 s sig. (1-tailed) 0.043 90 dropbox 2 aseel f 7-13 .pdf simplify your life dropbox 10 sahar f 60-64.pdf simplify your life ahlam.doc j bagh college dentistry vol. 26(4), december 2014 oral health status pedodontics, orthodontics and preventive dentistry147 oral health status among fifteen years-old students in maysan governorate\iraq ahmed m. mughamis, b.d.s. (1) ahlam t. mohammed, b.d.s, m.sc. (2) abstract background: dental caries and periodontal disease are the most common and widely spread diseases affecting humans at different ages. aim of this study is the assessment of prevalence and severity of dental caries, gingivitis, oral hygiene and enamel anomalies in relation to gender and residency among 15 years old students in maysan governorate –iraq. materials and methods: the total sample composed of 750 students (400 males and 350 females, 450 urban and 300 rural) selected randomly from different high schools in the governorate. diagnoses and recording dental caries was according to the criteria of who (1987), plaque index of silness and loe (1964) was used for plaque assessment, ramfjord index (1959) was applied for the assessment of calculus, gingival index of loe and silness (1963) was followed for recording gingival health condition and criteria of who (1997) to assess enamel anomalies. results: caries prevalence was found to be (92.53%) of the total sample. the dmfs value was higher among females compared to males with statistically high significant difference (p<0.01) also the value was higher among rural compared to urban with statistically high significant difference (p<0.01). plaque, gingival and calculus indices were higher among rural than urban and higher among males than females, statistically, there were high significant differences regarding plaque and gingival indices (p<0.01) while non-significant difference regarding calculus index (p>0.05), for both genders and residencies. conclusion: a high prevalence of dental caries and gingivitis were recorded indicating the need of a public health programs in this governorate. keywords: dental caries, oral hygiene, gingivitis, maysan governorate. (j bagh coll dentistry 2014; 26(4):147-151). الخالصة ھدف ھذه الدراسة لتقییم انتشار وشدة تسوس . تسوس االسنان ومرض ما حول السن االكثر شیوعا واالوسع انتشارا التي تؤثر على االنسان في مختلف االعمار :خلفیةال .العراق-محافظة میسانسنة في 15نظافة الفم وعیوب المینا بالنسبة الى الجنس واالقامة بین الطالب بعمر , التھاب اللثھ,االسنان تشخیص . اختیرت عشوائیا من مدارس ثانویة مختلفة في المحافظة) ریف 300حضر و 450,اناث 350ذكور و 400(طالب 750تتكون العینة الكلیة من : المواد والطرق دلیل رامفورد , استخدم لقیاس الصفیحة الجرثومیة) 1964(ولو دلیل الصفیحة الجرثومیة لسلنس, )1987(وتسجیل تسوس االسنان كان حسب معاییرمنظمة الصحة العالمیة .لتقییم عیوب المینا) 1997(اتبع لتسجیل حالة اللثة الصحیة و معاییر منظمة الصحة العالمیة ) 1963(دلیل اللثة للو و سلنس , طبق لتقییم القلح) 1959( كانت اعلى بین االناث بالمقارنة بالذكور مع اختالف معنوي كبیر احصائیا ) (dmfsقیمة تسوس اسطح السن . یةمن العینة الكل) 92.53(وجد ان انتشار تسوس االسنان : النتائج )p<0.01 ( ایضا القیمة كانت اعلى بین الریف بالمقارنة مع الحضر مع اختالف معنوي كبیر احصائیا)p<0.01 .(ور اللثة و القلح كانت اعلى بین الذك, مقاییس الصفیحة الجرثومیة بینما ال یوجد اختالف معنوي بخصوص ) p<0.01(توجد اختالفات معنویة كبیرة بخصوص مقاییس الصفیحة الجرثومیة واللثة , احصائیا, من االناث واعلى بین الریف من الحضر .لكل من الجنس ومكان االقامةp>0.05) (مقیاس القلح .لثة التي سجلت تحدد الحاجة الى برامج صحة عامة في ھذه المحافظةنسبة انتشار عالیة لتسوس االسنان والتھاب ال :الخاتمة .محافظة میسان, التھاب اللثة, نظافة الفم, تسوس االسنان: الكلمات الدلیلیة introduction dental caries continues to be one of the most common infectious disease known to man, despite widespread preventive measure, this disease exerts a social, physical, mental and financial burden on a global scale especially in developing countries (1,2). the disease is a chronic irreversible progressive in nature, untreated lesions may progress to cause pain, infection and discomfort to the subject, and finally it might end with the loss of the tooth (3).gingivitis and periodontitis are the two major forms of inflammatory diseases affecting the periodontium but the most common type of periodontal disease that can be seen in children is gingivitis which is a reversible condition may (1) m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. start early in life and increase in severity with advancing age (4,5). however, gingivitis if not treated may progress later to periodontitis and if this progress, it may end with loss of teeth (6). enamel anomalies is a disturbances in hard tissue matrices and in their mineralization during odontogenesis that clinically appeared in three forms; demarcated opacities, diffuse opacities and hypoplasia that results in many problems as esthetic, occlusal, dental sensitivity and predisposing factor for dental caries (7). there were many epidemiological studies concerning oral health status in different location of iraq (8-10). as there were no previous epidemiological studies concerning oral health of people in maysan governorate, therefore this study was designed. the aim of this study included the investigation of the prevalence and severity of dental caries, gingivitis, dental plaque, dental calculus and enamel anomalies in relation to area of residency and gender. j bagh college dentistry vol. 26(4), december 2014 oral health status pedodontics, orthodontics and preventive dentistry148 materials and methods this oral health survey was conducted among high school students during the period between the middle of january (2013) till the end of april (2013) in maysan governorate, iraq. in this study the sample consist of (750) 15 years old school students, the school were randomly selected, they were distributed in different geographical location in maysan governorate. adolescents who look healthy and without any medical disease were examined only. diagnosis and recording of dental caries was assessed according to the criteria described by who (11). plaque index of silness and loe (12) was used for plaque assessment, ramfjord index (13) was applied for the assessment of calculus, gingival index of loe and silness (14) was followed for recording gingival health condition and enamel anomalies index of who (7) to assess enamel anomalies. results table (1) demonstrates the distribution of total sample by gender and area of residency. results showed that the prevalence of dental caries was (92.53%) for the total sample; (89.25%) males and (96.28%) females with no significant difference (p>0.05), (90.0%) urban and (96.33%) rural with highly significant difference (p<0.01), table (2). as showed in table (3) the dmfs and its components (ds, ms, fs). dental caries was found to be higher in females compared to males, difference was found to be statistically highly significant (p<0.01), also dental caries was higher in rural than that in urban with high significant difference (p<0.01). the decayed surfaces (ds) were found to contribute the major part of dmfs value, while the filled surfaces (fs) were the less value. table (4, 5 and 6) showed plaque, calculus and gingival indices respectively, mean value of plaque index was (1.03±0.01), calculus index (0.03±0.01) and gingival index (0.88±0.01). concerning plaque and gingival indices, a high significant differences were reported within categories of residency (urban, rural) and gender (p<0.01), while no significant difference was reported with calculus index for both categories (gender and residency) (p>0.05). prevalence of enamel anomalies was (19%) of total sample; the most prevalent type was diffuse opacities (10%) while the lowest was hypoplasia (1.5%) as showed in figure (1). table (7) shows no significant correlation between urban and rural or male and female students (p>0.05). table 1: distribution of total sample by residency and gender table 2: prevalence of dental caries among students by residency and gender. area of residency males females total chi-square no. % no. % no. % urban 185 41.11 220 48.89 405 90.00 ** 0.00 rural 172 57.33 117 39.00 289 96.33 total 357 89.25 337 96.28 694 92.53 chi-square (ns) ** highly significant, p<0.01. area of residency urban rural total no. % no. % no. % males 217 28.93 183 24.4 400 53.33 females 233 31.07 117 15.6 350 46.67 total 450 60.0 300 40.0 750 100 j bagh college dentistry vol. 26(4), december 2014 oral health status pedodontics, orthodontics and preventive dentistry149 table 3: caries experience (dmfs) among students by residency and gender residency gender ds ms fs dmfs t-test mean ±s.e. mean ±s.e. mean ±s.e. mean ±s.e. urban males 7.88 0.45 0.76 0.15 0.11 0.05 8.76 0.55 ** 0.00 ** 0.00 females 11.95 0.41 1.41 0.17 0.00 0.00 13.38 0.49 total 9.99 0.32 1.10 0.12 0.06 0.02 11.15 0.38 rural males 11.73 0.46 0.49 0.14 0.00 0.00 12.22 0.50 ** 0.00 females 13.88 0.49 1.88 0.26 0.02 0.01 15.78 0.57 total 12.57 0.34 1.03 0.13 0.01 0.05 13.61 0.39 total males 9.65 0.34 0.63 0.10 0.06 0.02 10.35 0.38 ** 0.00 females 12.60 0.32 1.57 0.01 0.01 0.06 14.18 0.38 total 11.02 0.24 1.07 0.09 0.04 0.01 12.14 0.28 ** high significant, p < 0.01. table 4: plaque index (mean ± s.e.) among students by residency and gender area of residency gender t-test males females total mean ±s.e. mean ±s.e. mean ±s.e. urban 1.02 0.02 0.95 0.02 0.98 0.01 0.00** rural 1.15 0.02 1.01 0.02 1.09 0.01 total 1.08 0.01 0.97 0.01 1.03 0.01 t-test 0.00** ** high significant, p < 0.01. table 5: calculus index (mean ± s.e.) among students by residency and gender. area of residency gender t-test males females total mean ±s.e. mean ±s.e. mean ±s.e. urban 0.86 0.02 0.81 0.02 0.03 0.01 0.067(ns) rural 1.00 0.02 0.86 0.02 0.04 0.02 total 0.93 0.01 0.82 0.01 0.03 0.01 t-test 0.196 (ns) (ns)= not significant, p > 0.05 table 6: gingival index (mean ± s.e.) among students by residency and gender. area of residency gender t-test males females total mean ±s.e. mean ±s.e. mean ±s.e. urban 0.05 0.01 0.01 0.00 0.83 0.01 ** 0.00 rural 0.07 0.00 0.00 0.00 0.95 0.01 total 0.06 0.00 0.01 0.00 0.88 0.01 t-test 0.00** ** high significant, p < 0.01. table 7: number of affected students by enamel anomalies in relation to residency and gender. residency males females total chi-square no. % no. % no. % urban 37 8.22 37 8.22 74 16.44 (ns) rural 45 15.00 25 8.33 70 23.33 total 82 20.50 62 17.71 144 19.20 chi-square (ns) (ns) not significant, p > 0.05 j bagh college dentistry vol. 26(4), december 2014 oral health status pedodontics, orthodontics and preventive dentistry150 2% 10% 1.5% 5% 0.5 male female total 90% 60 30 percent. figure 1: percentage of total sample according to enamel anomalies types. discussion this study was designed to investigate oral health status of high school students aged 15 years old which was an index age (7). it was achieved in maysan governorate because there was no previous epidemiological study concerning this age or any other age group carried out in this governorate so this study's results can be considered as base line data to compare with other studies in the future also produce a reliable baseline data for development of national or regional oral health programs. in this study the prevalence of dental caries was found to be (92.53%). this was higher than that reported by others (9, 10, 15). it is well known that systemic fluoridation can widely reduce the prevalence and severity of dental caries (18). the concentration of fluoride in communal water supply in different governorates in iraq is ranging from 0.120.22 ppm (8) this level is far beyond the optimal level recommended for maximum of dental caries (0.71.2) (16). this may give some explanation to the high prevalence of dental caries reported in this study. the result of dmfs was (12.14± 0.28) which was higher than that reported by other in different parts of the world (17). in general variation in caries experience between this study and other iraqi studies may be partially attributed to variation in dietary habits, oral hygiene measures as well as dental health services between governorates; however this may need further studies to confirm this observation. this study showed that the decayed (ds) was the major component of dmfs index; this result was in agreement with other studies (9, 10, 18, 19) and may reveal the poor demand for dental treatment. in comparison between filled and extracted surfaces, ms was greater than fs, this may indicates that even if treatment was present it was directed for extraction rather than preserving teeth. findings of this study showed that the mean value of plaque, gingival and calculus indices were lower than that reported by other studies (15, 18) but higher than that reported by another (10, 19) in different parts of iraq, this may be attributed to variation in oral hygiene measure between governorates. the prevalence of enamel anomalies in this study was (19%), this result was lower than that reported by other (20). males more affected by enamel anomalies than females, this may be partially attributed to inherent males vulnerability to stress, males on stressful environments exhibit higher enamel anomalies than females. rural students more affected than urban, this may be partially explained by that people in urban area had better nutrition's which play important role in teeth formation (20). references 1. cameron a, widmer r. handbook of pediatric dentistry. 3rd ed. mosby, elesvir; 2008. 2. fejerskov o, kidd e. dental caries (the disease and its clinical management). munksgward: blackwell; 2008. 3. caucified p, li y, dasanayake a. dental caries: an infectious and transmissible disease. compend contin educ dent 2005; 26(5):10-6. 4. dumitrescu al. etiology and pathogenesis of periodontal disease. new york: springer; 2010. j bagh college dentistry vol. 26(4), december 2014 oral health status pedodontics, orthodontics and preventive dentistry151 5. dhoble a. pedodontics (questions and answers). bangalore, new delhi, 2008. 6. chestnutt ig, gibson j. clinical dentistry. 3rd ed. churchill livingstone elsevier; 2007. 7. who. oral health surveys basic methods. 4th ed. world health organization. geneva, switzerland 1997. 8. al-azawi la. oral health status and treatment needs among iraqi five-year old kindergarten children and fifteen-year old students (a national survey). ph.d. thesis, college of dentistry, university of baghdad, 2000. 9. al-jebouri h. oral health status among 15 years old in hilla governorate. a master thesis, college of dentistry, university of baghdad, 2007. 10. al-obaidi ej. oral health status and treatment need among 15 years-old students in al-diwania governorate iraq. a master thesis, college of dentistry, university of baghdad, 2008. 11. who. oral health surveys basic methods. 3rd ed. world health organization. geneva, switzerland 1987. 12. silness j, loe h. periodontal disease in pregnancy. correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22: 121-35. 13. ramfjord sp. indices for prevalence and incidence of periodontal disease. j perio 1959; 30: 51-9. 14. loe h, silness j. periodontal disease in pregnancy i. acta odontol scand 1963; 21: 533-51. 15. abdul-razzaq q. oral health status among 15 yearold school students in sulaimania city-iraq. a master thesis, college of dentistry, university of baghdad, 2007. 16. murry j, nunn j, steel j. the prevention of oral disease. 4th ed, newyork: oxford: 2003. 17. baram a. oral health status and treatment needs among primary school children in sulaimani city. a master thesis, college of dentistry, university of baghdad, 2007. 18. al-ghalebi s. oral health status and treatment need in relation to nutritional status among 9-10 year-old school children in nassirya city/iraq. a master thesis, college of dentistry, university of baghdad, 2011. 19. al-sadam n. oral health status in relation to nutritional and social status in kerbala governorate for primary school students aged 12 years-old. a master thesis, college of dentistry, baghdad university, 2013. 20. diab bs. nutritional status in relation to oral health condition among 6-10 years primary school children in middle region of iraq. ph.d. thesis, college of dentistry, university of baghdad, 2003. j bagh college dentistry vol. 31(3), september 2019 the effects of 44 the effects of thumb sucking habit on the development of malocclusions in preschool age children in hilla city saba mohamed al-kinane, b.d.s. (1) zainab a.a.al-dahan, b.d.s, m.s.c. (2) abstract background: habit is any purposeless action repeated unconsciously. it is a sign of lack of harmony between the subject and the surrounding environment. deleterious oral habits such as finger sucking could be one of the etiological factors for altered oro-facial growth development. this study conducted to explore the association between finger sucking habit and malocclusion in deciduous dentition. materials and method: totally 40 chronic thumb sucker and 40 controls matching in age and gender were enrolled in the study. a study conducted by verifying different occlusal trait through the intra-oral examination. thumb sucking habit diagnosed using data gathered from parents. results: the statistical analysis showed a highly significant difference (p>0.01) in the occurrence of anterior open bite, increased over jet between study and controls, in addition to that thumb sucking habit increased the likelihood of development of anterior open bite, increased overjet and posterior cross bite by 39 folds, 40 folds and 3 folds respectively. conclusions: thumb sucking habit found to be a risk factor for the development of anterior open bite and increased overjet. key words: thumb sucking habit, anterior open bite, increased over jet, posterior cross bite. (received: 15/8/2016; accepted: 12/12/2016) introduction habit is a behavior that had been obtained through persistent repetition or physiologic exposure (1). repetitive behaviors are prevalent during infantile period and most of these behaviors begins and discontinue spontaneously (2). oral habits are so common and one of the deleterious habits that represent a problem for both pediatricians and pedodontists (3, 4) because they had been implicated as an important environmental etiological factor associated with a faulty dento-facial development (5, 6). thumb/finger sucking habit are regarded to be the most prevalent of oral habit with detected incidence ranging from 13% to 100% at some time during infancy (3). thumb sucking habit have been submitted to participate in the development of incorrect occlusion in the deciduous dentition and this faulty occlusion can be carried forward to the permanent occlusion as there is a common believe that the deciduous dental arches are the basis for normal development of permanent dental arches (7). anterior open bite, increased overjet and posterior cross bite were the most recorded occlusal traits associated with the thumb sucking(8-11). the tendency toward developing of abnormal swallowing had been reported to increase in children with finger sucking, who showed a high frequency of compensatory tongue thrust leading to higher frequency of anterior open bite, unilateral or bilateral disto-occlusion and increased maxillary overjet (12). the severity of malocclusion developed as a consequence to thumb sucking habit depends on many factors including duration and times of doing the habit, the position of the finger in the mouth, the relation between the maxilla and mandible and the child's health (3, 13). larreson and bishara(14) stated that the malocclusions that had been attributed to thumb sucking habit were more harmful than those produced by other non-nutritive sucking habit such as pacifier sucking as the thumb used in the sucking habit will act as a lever producing a force displacing maxillary teeth anteriorly causing greater increase in the overjet, elongation and proclination of anterior maxillary base than those caused by the pacifier. in the first 3-4 years of age the deformity caused by thumb sucking is mainly confined to the anterior segment. this deformity usually temporary if the habit quitted before school age but if continues beyond this age children will invariably develop malocclusion at 12 years (15). there is apparent positive relationship between oral habit and anterior open bite with a higher (1) m.sc. student, department of pedodontic and preventive dentistry, collage of dentistry, university of baghdad. (2) professor, department of pedodontic and preventive dentistry, collage of dentistry, university of baghdad j bagh college dentistry vol. 31(3), september 2019 the effects of 45 predisposition toward class ii molar relationship in those with initial class i (16). anterior open bite in turn had a bad outcomes such as the aesthetic problems, lingual interpositioning during swallowing, difficult biting on the incisors added to that speech problems represented by atypical phonation affect the production of the following phonetic sounds:/t/, /d/, /n/, /l/, /r/ (17). pădure , ngru (18) stated that thumb sucking habit in addition to hereditary factor are important etiological factor for class ii/ 1 malocclusion development. several authors stated that increased overjet attributed to thumb sucking habit resulted from elongation and advancement of anterior segment of maxillary arch in addition to the proclination of the upper incisors (8, 9, 19) . posterior cross bite may be results from thumb sucking habit practice if the habit continues after the age of 36 months.(11) and it is persistent and not a self-corrected if the habit ceases. (8) therefore, some malocclusion can be seen even in mixed dentition stage of dental development (20). al-dawoody (9) stated that posterior cross bite in thumb sucker developed as a result of decrease in maxillary arch width and increase in the mandibular arch width. the widening of mandibular arch resulted from positioning of tongue as it displaced by the thumb. a previously conducted studies mentioned that posterior cross bite attributed to dummy sucking habit rather than thumb sucking habit (8, 11, 20-22). the harmful effect of thumb sucking habit on development of occlusion was found to be the main reason behind mothers attempts to stop this habit in their children (23). materials and metods a case control study conducted on 80 preschool children attending kindergarten and nursery schools in hilla city. the first group of fourty children practicing the finger sucking habit at the time of examination and the other 40 children chosen to be a control for the cases and matching them in both age and gender. the children with the thumb sucking habit diagnosed as a thumb sucker by using data obtained from parents through a selfadministered questionnaire. examination had been done during the school day in the day light and by using disposable dental mirror, millimeter graded vernier, face mask, and gloves. the results recorded in an organized case examination sheets. children with any oral or systemic condition that may influence the results; children with oral habits other than thumb sucking and children lost antagonist central incisors to whom overjet and over bite cant obtained were excluded from the study. the occlusal relationship were examined by direct visual inspection of the teeth at centric occlusion and the arch characteristics were recorded using published definitions (7). 1. overbite: gained by measuring the vertical distance between the incisal edges of upper and lower incisors while teeth in centric relationship by instructing the child to open and close the mouth many times and to swallow the saliva before examination and sometimes it is necessary to gently guided the mandible into centric occlusion by the examiner. the distance had been regarded normal when upper incisors covered the lowers up to 3 mm; and deep bite if it is greater than 3 mm. while the open bite recorded present if there was no overlap between the upper and lower teeth with a minimum space of 1 mm between edges. reverse over bite represent the coverage of upper incisors by lower incisors where they were in inverted position. 2. over jet: gained by measuring the horizontal distance between the upper and lower incisors while teeth in centric relationship. the distance between the incisal of most prominent upper incisor and the buccal surface of corresponding lower incisor considered normal when it is about 3 mm, while the distance more than 3 mm regarded as increased overjet. reverse overjet( anterior cross bite) recorded when the incisors were in an inverted position with the lower incisal edge occluding buccaly to the upper incisal edge. 3. posterior cross bite: when the buccal cusps of mandibular molars where buccaly displaced regarding the buccal cusps of the upper molar, posterior cross bite recorded as present regardless of the side. data of this study had been translated into a computerized database structure. ibmspss version 21 computer software (ibm statistical package for social sciences) in association with microsoft excel were used for the statistical analysis. results three occlusal trait which are anterior open bite, increased overjet and posterior cross bite were most commonly detected among children whom j bagh college dentistry vol. 31(3), september 2019 the effects of 46 chronically suck their fingers with the anterior open bite recorded the highest frequency (50%) followed by increased overjet and posterior cross bite respectively fig.(1). results in table (1) showed that there is a highly significant differences between the cases and controls groups in the occurrence of both anterior open bite and increased overjet which were higher among cases group subject, while the difference between the two groups in the prevalence of posterior cross bite failed to reach the level of statistical significance. the result of adjusted odds ratio indicated that thumb sucking habit is a risk factor for development of anterior open bite, increased overjet and posterior cross bite and increase the likelihood of their occurrence by 39 folds, 40 folds and 3 folds respectively. there is an obvious difference in the occurrence of posterior cross bite among gender groups with males children were higher than females. however, the difference between gender groups of children practicing the thumb sucking habit in the occurrence of malocclusion doesn’t large enough to give a statistical significance. table (2). table (3) summarizes the frequencies of increased over jet, anterior open bite and posterior cross bite in different age groups of children with a thumb sucking habit. the occurrence of posterior cross bite obviously higher in older ages (4 years) than the younger age (3 years) but this difference together with differences in the incidence rates of the increased overjet and anterior open bite not statically significant. further details about the distribution of the mentioned malocclusions among age and gender group seen in tables (4),(5),(6). figure 1: bar chart showing the relative frequency of selected outcomes in subjects with a positive history of thumb sucking habit compared to controls. table 1: the risk of having selected outcomes in subjects with positive thumb sucking habit compared to controls. variables thumb sucking or inverse or 95%ci or p negative positive n % n % increased over jet 13 32.5 0 0 39.76 ** (4.9 319.9) >0.001[s] anterior open bite 20 50 1 2.5 39 ** (4.9 312.2) >0.001[s] posterior cross bite 6 15 2 5 3.35 ** (0.63 17.74) 1.103 [ns] deep bite 0 0 2 5 0.19 5.26 (0.02 1.91) 0.24 [ns] reverse over bite 0 0 1 2.5 0.33 3.08 (0.03 3.73) 0.500 [ns] reverse overjet 0 0 1 2.5 0.33 3.08 (0.03 3.73) 0.500 [ns] j bagh college dentistry vol. 31(3), september 2019 the effects of 47 table 2: the relative frequency of selected outcomes by gender among cases group only. malocclusions gender p females (n=22) males (n=18) n % n % increased over jet 8 36.4 5 27.8 0.56[ns] anterior open bite 12 54.5 8 44.4 0.53[ns] cross bite 5 22.7 1 5.6 0.2[ns] table 3: the relative frequency of selected outcomes by age among cases group only. malocclusions age (years) p 3 years old (n=17) 4 years old (n=23) n % n % increased over jet 4 23.5 9 39.1 0.3[ns] anterior open bite 10 58.8 10 43.5 0.34[ns] cross bite 1 5.9 5 21.7 0.22[ns] table 4: distribution of anterior open bite malocclusion among cases and controls group. anterior open bite cases controls total n anterior open bite total n anterior open bite n % n % 3 years 6 4 66.7 5 0 0.0 4 years 61 8 50.0 16 0 0.0 total 22 12 54.5 22 0 0.0 3 years 66 6 54.5 11 0 0.0 4 years 7 2 28.6 7 1 14.3 total 18 8 44.4 18 1 5.6 3 years 61 10 58.8 17 0 0.0 4 years 23 10 43.5 23 1 4.3 total 40 20 50.0 40 1 2.5 table 5: distribution of increased over jet occlusal trait among cases and controls group. increased over jet non thumb sucking thumb sucking total n positive increased overjet total n positive increased overjet n % n % 3 years 6 3 50 6 0 0.0 4 years 16 5 31.3 16 0 0.0 total 22 8 36.4 22 0 0.0 3 years 11 1 9.1 11 0 0.0 4 years 7 4 57.1 7 0 0.0 total 18 5 27.8 18 0 0.0 j bagh college dentistry vol. 31(3), september 2019 the effects of 48 table 6: distribution of posterior cross bite among cases and controls group. posterior cross bite cases group control group total n posterior cross bite total n posterior cross bite n % n % 3 years 6 1 16.7 6 0 00. 4 years 16 4 25 16 0 0.0 total 22 5 22.7 22 0 0.0 3 years 11 0 0.0 11 2 18.2 4 years 7 1 14.3 7 0 0.0 total 18 1 5.6 18 2 11.1 3 years 17 1 5.9 17 2 11.8 4 years 23 5 21.7 23 0 0.0 total 40 6 15 40 2 5.0 discussion the occurrence of anterior open bite, increased over jet and posterior cross bite were higher among the children who were practicing the oral habit, thumb sucking, than control group this result in accordance with other studies (16, 24-28). the most striking differences between cases and controls group were the incidence of anterior open bite and the relative increase in overjet which were significantly more prevalent in cases group. indeed none of thumb sucking group children show an increase in the overjet measurement this is in accordance with a previous study by botham (29). the most dramatic evidence of the influence of thumb sucking habit on development of occlusion represented by the high occurrence of anterior open bite among thumb sucking practicing group this result in agreement with other researches (12, 30). the adjusted odds ratio of anterior open bite indicates that thumb sucking habit was a risk factor for the development of anterior open bite by 39 folds. this study found a highly significant statistical difference for the occurrence of increased overjet in thumb sucking children; this is in agreement with other researches(8, 12) who reported that thumb sucking causes more class ii division 1 types of malocclusion. in addition to that thumb sucking habit appeared to increase possibility of developing such malocclusion by 40 folds. this study concluded that there is no statistical difference between the cases group and controls group in the occurrence of posterior cross bite this result in accordance with singh et al and miotto et al (12, 22) but, disagree with results of previously conducted studies (27, 30) who found that the posterior cross bite had been observed to directly associated with oral habits the adjusted odds ratio for posterior cross bite was giving an indication that thumb sucking habit was a risk factor and increasing 3 times the likelihood of the development of posterior cross bite. from comparing the occurrence of malocclusions in cases group only the study showed that the frequencies of malocclusion are not age related neither gender related as there is no statistical difference among age and gender groups in the occurrence of malocclusions attributed to the oral habit this agree with adair study (31). occlusal traits including anterior open bite, increased over jet and posterior cross bite were more prominent among children practicing thumb sucking habit this may be attributed to the forceful sucking of the thumb with associated strong buccal and lip musculature contraction in addition to the position of the thumb between teeth this is in agreement with kamdar and alshahrani (32). references 1. merriam-webster. "habit definition and more from free merriam-webster dictionary", 2011. 2. rajchanovska d, zafirova-ivanovska b.oral habits among pre-elementary children in bitola. biol med sci 2012; 33(1):157-69. 3. maguire ja. the evaluation and treatment of pediatric oral habits. dental clin north am 2000;44(3):659-69. 4. carlsson ge, egermar k, magnusson t. predictors of bruxism, other oral parafunctions, and tooth wear over a 20-year follow-up period. j orofac pain 2003;17(1):50-7. 5. warren jj, levy sm, nowak aj, tank s. nonnutritive sucking behaviors in preschool children: a longitudinal study. pediatr dent 2000; 22(3):187-91. j bagh college dentistry vol. 31(3), september 2019 the effects of 49 6. kharbanda o, sidhhu s, sundaram k, shukla d. oral habits in school going children of delhi: a prevalence study. j indian soc pedo prev dent 2003;21(3):120-4. 7. moimaz, sas. garbin aji, lima amc, lolli, lf, saliba, o. garbin caa. longitudinal study of habits leading to malocclusion development in childhood. bmc oral health 2014; 14(96): 26. 8. warren jj, bishara se. duration of nutritive and nonnutritive sucking behaviors and their effects on the dental arches in the primary dentition. am j orthod dentofacial orthop 2002;121(4):347–56. 9. al-dawoody a. finger sucking prevalence. contributing factors and effect on occlusion. alrafidain dent j 2004; 4(4): 135-42. 10. ozawa n, hamada s, tekekoshi f, shinji h. a study on non-nutritive sucking habits in young japanese children. pediatr dent j 2005;15(1):64-71. 11. duncan k, mcnamara c, ireland aj, sandy j. sucking habits in childhood and the effects on the primary dentition: findings of the avon longitudinal study of pregnancy and childhood. int j paediatr dent 2008;18(3):178-88. 12. singh sp, utreja a, chawla hs. distribution of malocclusion types among thumb suckers seeking orthodontic treatment. j indian soc pedod prevent dent 2008;26(7): 114-7. 13. yemitan ta, dacosta oo, sanu oo, isiekwe mc. effects of digit sucking on dental arch dimensions in the primary dentition. afri j medicine med sci. 2010;39(1):55-61. 14. larreson e, bishara s. pacifier and digit sucking habits (evidence for practice). canadian journal of dental hygiene 2007;42(1):22-9. 15. franco vv, gorritxo bg. pacifier sucking habit and associated dental changes. importance of early diagnosis. an pediatr (barc) 2011;77(6):374-80. 16. warren jj, slayton rl, bishara se, levy s, yonezu t, kanellis m. effects of nonnutritive sucking habits on occlusal characteristics in the mixed dentition. pediatr dent 2005;27(6):445-450. 17. ize-iyamu in, isiekwe mc. prevalence and factors associated with anterior open bite in 2 to 5 year old children in benin city, nigeria. afri health sci 2012;12(4). 18. pădure h, ngru ar, stanciu d. the class ii/1 anomaly of hereditary etiology vs. thumb-sucking etiology. j med life 2012; 5(2):239-41. 19. kato m, watanabe k, kato e, hatto h, daito m. three dimentional measurement of the palate using the semiconductor laser: on the influence of the palate of maxillary protrusion with finger sucking. pediatr dent j 2009;19(1):25-9. 20. montaldo l, montaldo p, cuccaro p, caramico n, minervini g. effects of feeding on non-nutritive sucking habits and implications on occlusion in mixed dentition. int j paediatr dent 2011; 21(1): 68-73. 21. bishara se, warren jj, broffitt b, levy sm. changes in the prevalence of nonnutritive sucking patterns in the first 8 years of life. am j orthod dentofacial orthop 2006;130(1):31-6. 22. miotto m, cavalcante w, godoy l, campos d, barcellos l. prevalence of posterior cross bite in 3-5 years-old children from vitoria, brazil. brazilian research in pediatric dentistry and integrated clinic 2015;15(1):57-64. 23. chopra a, lakhanpal m, singh v, gupta n, rao nc, suri v. the habit of the digit sucking among children and the attitude of mother's toward the habit in india. tmu j dent 2015;2(1):1-4. 24. bishara s. textbook of orthodontics. philadelphia: wb saunders, 2002. 25. luz clf, garib dj, arouca r. association between breast feeding duration and mandibular retrusion, a cross sectional study of children in mixed dentition. am orthod dentofacial orthop 2006;130(4):531-4. 26. barbosa c, vasquez s, parada ma, gonzalez jc, jackson c, yanez n, gelaye b, fitzpatrick al. the relationship of bottle feeding and other sucking behaviors with speech disorder in patagonian preschoolers. bmc pediatrics. 2009;9(66):1-8. 27. melnik s, vagner mv, hocevar-boltezar i, ovsenik m. posterior cross bite in deciduous dentition period, its relation with sucking habits, irregular orofacial functions and otolaryngological findinga. am j orthod dentofacial orthop 2010;138(1):32-40. 28. aznar t, galán af, marín i, domínguez a. dental arch diameters and relationships to oral habits. angle orthod 2006;76(3): 441-5. 29. botham a. the effects of thumb sucking on dental charecterstics in primary dentition. johannesburg: witwatersrand, 2011. 30. kasparaviciene k, sidlauskas a, zasciurinskiene e, vasiliauskas a, juodzbalys g, sidlauskas m, marmaite u. the prevalence of malocclusion and oral habits among 5-7 years old children. med sci monit. 2014;20:2036-42. 31. adair sm. pacifier use in children: a review of recent literature. pediatr dent 2003; 25(5): 449-58. 32. kamdar rj, al-shahrani i. damaging oral habits. j int oral health 2015;7(4):85-7. الخالصة الضارة الفموية العادات ان. المحيطة والبيئة الفرد بين االنسجام عدم على داللة هو بل وعي دون ومن هدف بال يكرر عمل أي هي العادة :الخلفية بين العالقة استكشاف لغرض الدراسة هذه اجراء تم وقد والفم للوجه الطبيعي النمو على المؤثرة العوامل من واحدة هي اإلصبع مص عادة مثل . اللبنية األسنان في اإلطباق وسوء االصبع مص عادة سوء وجود عن الكشف تم. والجنس العمر في مطابقون اربعون مع االصبع مص عادة على مستمرين طفال اربعون الدراسة شملت :ومواد طرق . االصبع مص عادة وجود تشخيص في واالمهات االباء قبل من جمعها تم التي البيانات استخدمت بينما الفموي الفحص طريق عن االطباق في االمامية االسنان بين االفقية المسافة وزيادة األمامية المفتوحة العضة حدوث نسبة في كبيرا معنويا فرقا اإلحصائي التحليل أظهر :النتائج زيادة الى تؤدي االصبع مص عادة ان وجد ذلك إلى باإلضافة الطبيعيين باألطفال مقارنة االصبع مص عادة على المستمرين االطفال مجموعة و ضعف 04 و ، ضعف 39 بنسبة الخلفي العكسي االطباق و االمامية االسنان بين االفقية المسافة وزيادة المفتوحة، االمامية العضة حدوث احتمال . التوالي على أضعاف 3 . االمامية االسنان بين االفقية المسافة وزيادة المفتوحة االمامية العضة لتطوير خطر عامل االصبع مص عادة: االستنتاج j bagh college dentistry vol. 31(3), september 2019 the effects of 50 mohammad f.doc j bagh college dentistry vol. 25(3), september 2013 evaluation of restorative dentistry 43 evaluation of antibacterial action of photosensitizer solution activated by diode lamp and three intracanal medicaments (in vitro study) mohammed c. hirais, b.d.s. (1) hussain f. al-huwaizi, b.d.s., m.sc., ph.d. (2) abstract background: the elimination of the microorganisms from the root canal systems, an important step for the successful root canal treatment. this study was conducted to evaluate the antibacterial effectiveness of the photoactivated disinfection by using the toluidine blue o and a lowenergy light emitting diode (led) lamp . materials and method: sixty single rooted extracted teeth were decoronated, instrumented, irrigated, sealed at the apex and contaminated with endodontic anaerobic bacteria for 7 days to form biofilms in prepared root canals. group i. twelve teeth were medicated by photosensitizer (toluidine blue o) solution activated by diode lamp (fotosan; cms dental, copenhagen, denmark).group ii. twelve teeth were medicated by the tricresol formalin. group iii. twelve teeth were medicated by the camphorated monochlorophenol (cmcp). group iv. twelve teeth were medicated by calcium hydroxide (ca(oh)2) paste. group v. without the intracanal medication (control group). the bacterial swabs were taken before and after medication and following the photoactivated disinfection procedure immediately and after 7days. the canal contents were swabbed by paper points inserted to the root canals, serially diluted and cultured on blood agar. survival fractions were calculated by counting colony-forming units. result: treatment of the root canals with pad (fotosan) caused a high significant reduction of the bacterial count, resulting in a 96.39% elimination of root canal bacteria, followed by root canal treated by tricresol formalin (group ii),then cmcp (group iii) and ca(oh)2 (group iv) respectively. conclusion: light activated disinfection possesses potent antibacterial action against the anaerobic bacteria cultivated in root canals. key words: photoactivated disinfection, fotosan, anaerobic bacteria. (j bagh coll dentistry 2013; 25(3):43-48). introduction microorganisms are the primary an etiologic factor in the development of pulp and periapical diseases 1. endodontic pathogens have developed a variety of strategies to survive in adverse conditions. they may invade dentinal tubules and persist in superficial layers of dentin adjacent to the canal lumen 2, and they may organizeas biofilms, complex sessile communities performing numerous adaptive changes in behavior that increase their resistance to a variety of chemotherapeutic agents compared with their planktonic counterparts 3. conventionally, disinfection of the root canal is sought by a “chemomechanical” approach that involves cleaning and shaping of the root canal system by the application of a chemical disinfectant and mechanical instrumentation 4. nonetheless, this technique often fails to eradicate bacterial biofilms completely, mostly because of various microbiological and anatomical factors 5. (1)master student, conservative department, college of dentistry, university of baghdad. (2)professor, conservative department, college of dentistry, university of baghdad. chemo-mechanical preparation of the root canal reduces endodontic infection, but microorganisms are able to survive within the complex anatomy of the root canal system 6. antimicrobial intracanal medicaments are used to complement the disinfection of the root canal system7. phototactivated disinfection (pad) is an antimicrobial strategy that combines a nontoxic photosensitizer and low-energy light to produce highly reactive singlet oxygen species, which results in microbial elimination 8. pad has emerged as a promising approach to eradicate endodontic pathogens 9. materials and method preparation of tooth specimens sixty human single-rooted extracted teeth were used. the tooth specimens were selected for the experiments after inspecting for any signs of cracks or damages on the cementum .the teeth were decoronated to obtain root segments with a standard length of 12 mm 10-12. the apical patency and the glide path presence were confirmed with a size 15 k-file .the working length was established with the same file, subtracting 1 mm from the file measurement at the point where it was just visible at the foramen. j bagh college dentistry vol. 25(3), september 2013 evaluation of restorative dentistry 44 the cleaning and shaping of root canals were performed in a crown-down manner 12 , using the protaper hand nickel titanium system. the canals were irrigated with 3 ml 6% naocl 12 throughout the instrumentation sequence (sx,s1,s2,f1,f2,f3) until finishing file f4 (40/ 0.6). after the preparation, each apex was sealed with the wax and the external surface coated with two layers of nail varnish to prevent the contamination. the teeth were mounted vertically in the addition silicon impression material blocks. prior to the inoculation, the specimens were sterilized by autoclaving for 15 minutes at 121 °c. contamination of the tooth specimens the bacterial suspension was prepared by adding 1 ml of isolated bacteria, cultivated in bhi-b for 24 hours, to 5 ml of fresh brianheart infusion broth. each root canal was completely filled with the bacterial suspension using the sterile 1-ml insulin syringes without overflowing. the sterile k-files #15 were used to carry the bacterial suspension to the entire root canal length by one inward and outward movement. then the roots incubated at 37°c for 7 days. the fresh culture medium was added to the canal at 2, 4, and 6 days after the initial inoculum .14 sample grouping the teeth specimens were divided according to the intracanal medicament: group i. twelve teeth were medicated by photosensitizer (toluidine blue o) solution activated by diode lamp (fotosan; cms dental, copenhagen, denmark). group ii. twelve teeth were medicated by tricresol formalin; by the cotton pellet technique. group iii. twelve teeth were medicated by camphorated monochlorophenol (cmcp);by the cotton pellet technique. group iv. twelve teeth were medicated by calcium hydroxide ca(oh)2 paste; by condensing it in the root canal. group v. twelve teeth were leaved without the intracanal medication (control group). light source and photosensitizer an led lamp emitting in the red spectrum with a power peak at 628 nm was the light source used throughout all the experiments of group i (fotosan; cms dental, copenhagen, denmark). the energy output was measured to be 1 j/s. a long tapered tip, referred to as the endodontic tip, was mounted to the device .with its apical size of 500 µm and a 0.03 taper in the apical part, it was inserted into the canals up to 3 mm short of the working length and guide the light to the apical parts. a liquid solution of the toluidine blue o (tbo; sigma-aldrich, st. louis, mo), a thiazine dye of the quinone-imine family, was used as photosensitizer in the experiments 15. procedure of medication 1. group i. tbo solution (0.1 mg/ml) was injected into the root canal using a sterile endodontic micro-needle (gauge 27) ensuring that the fluid passed to the working length. the endodontic tip was inserted into the canal 3 mm short of working length, and 30 seconds of irradiation followed 15. after swabbing, the canals were dried by paper points until they are dry, closed by dry cotton pellets and sealed by the temporary filling. 2. group ii and iii. the intracanal medicaments of 0.025 ml volume were placed in canal by cotton pellet technique by mean of a micropipette and then the teeth were sealed by the temporary filling. 3. group iv. the teeth were treated by calcium hydroxide which was placed by a fine needled syringe then the excess material was removed by cotton pieces, then the teeth were sealed by the temporary filling. microbiological samples were collected before and after medication with the sterile paper points (f3) inserted once, placed for 5 seconds to full working length then withdraw and transferred to tubes containing 1ml of 0.85% nacl solution and agitated in vortex for 1 minute. after serial dilutions in saline, aliquots of 0.1 ml were cultivated onto a petri dish containing the blood agar culture media 14. one cultured petri dish was incubated anaerobicaly at 37°c. after 24 hours, the bacterial colonies that grown on the culture medium were counted by the colony counter to verify the number of microorganisms present in the inoculums. results the count of the root canal bacteria was expressed as colony forming unit(cfu)×10³.the number of colonies recorded were multiplied by reverse of the dilution factor which had been selected by performing a pilot study to have a readable count of bacteria on the agar surface . the findings showed that the root canals treated by fotosan exhibited the least viable count of bacteria immediately after 30 second from treatment and after 7 day(1.75±0.75,0.25±0.05) respectively, followed by the root canals treated by tricresol formalin j bagh college dentistry vol. 25(3), september 2013 evaluation of restorative dentistry 45 (group ii),then cmcp (group iii) and ca(oh)2 (group iv) respectively (table 1). the results of this study showed that the root canals treated by pad exhibited high percentage of reduction of the bacteria count immediately after 30 second from treatment and after 7 day (96.36,99.48) respectively, followed by tricresol formalin (group ii), then cmcp (group iii) and ca(oh)2 (group iv) respectively. table (2) using lsd test, the results indicated that the light activated disinfection (group i) exhibited non significant difference between mean of the bacteria count after 30 second and after 7 day. the results also showed non significant difference between the light activated disinfection (after 30 second) and the tricresol formalin group but there were significant difference between the light activated disinfection (after 7 day) and tricresol formalin group. at the same time ,there were high significant differences between mean of the bacteria count after 30 second and after 7 day of the light activated disinfection (group i) when compared with other groups. table (3) discussion antibacterial efficiency of photoactivated disinfection (pad). the results of this study showed that the root canals treated by photoactivated disinfection exhibited high percentage of reduction of bacteria count immediately after 30 second from treatment and after 7 day (96.36, 99.48) respectively. these results coincide with rios et al 12, who found that root canals treated with photoactivated disinfection for 30 seconds alone exhibited a 2.9% survival rate of e. faecalis, whereas the combination of naocl followed by photoactivated disinfection lowered the survival rate to 0.1%. these results are in accordance with another study that reported a 97% reduction of e. faecalis viability in extracted human teeth using photoactivated disinfection with methylene blue and a laser but with longer treatment times (5 minutes). 16 soukos et al 16 reported that oral endodontic pathogens exposed only to methylene blue (25µg/ml) for 5 minutes in planktonic phase demonstrated high cytotoxicity .this toxicity, led to 79% to 100% reduction in cell numbers. the addition of red light of 665 nm with a fluence of 30 j/cm2 resulted in complete eradication of those species that were incompletely eliminated by methylene blue. methylene blue alone exhibited 83.2% reduction of e. faecalis biofilm species in the root canal system of extracted human teeth. the combined effect of methylene blue and red light did not lead to complete eradication of e. faecalis biofilms (97% reduction). these findings are in accordance with the results of this study. the results of the present study are in agreement with bergmans et al 17 who stated that the treatment of root canals with photoactivated disinfection (15 j) caused a significant reduction of the bacterial load, resulting in a 93.8% reduction of s. anginosus (p < 0.0001), a 88.4% reduction of e. faecalis (p < 0.05) and a 98.5% reduction of f. nucleatum (p < 0.0001), but no sterilization. the results of this study disagreed with seal et al 18 and lee et al 19 , who used phenothiazinebased photosensitizer and low-intensity red lasers against gram-positive bacteria but did not use an optical fiber to access the root canal lumen. seal et al found that 3% sodium hypochlorite irrigation reduced more streptococcus intermedius in the endodontic biofilms than photoactivated disinfection with 100 _g/ml toluidine blue and 21j of 632 nm laser light. the results of the present study are in agreement with schlafer et al 15 who found that the mean post treatment reduction of 95.82% (1.38 log10) showed that the effect of the light is again weaker on adherent organisms than on bacteria in suspension inside the canal lumen, which showed 99.7% (2.51 log10) killing, but foschi et al. in 200720 who demonstrated that sensitization of e. faecalis microorganisms colonizing the root canal of single rooted extracted human teeth with 6.25 mg/ml methylene blue for 5 minutes followed by exposure to red light with energy fluence of 60 j/cm2 light energy fluence at a power density of 100 mw/cm2 led to approximately 78% killing. prolonged antibacterial efficiency of photoactivated disinfection(pad) after 7 day. in the present study, the sampling of the root canals treated by photoactivated disinfection after 7 days showed that the percentage of reduction is increased from 96.36% to 99.48 % and lack the bacterial regrowth ,this results in agreement with garcez et al 21 who concluded that the use of photoactivated disinfection as an adjuvant to the conventional endodontic treatment leads to a statistically significant further reduction of bacterial load (p<0.05) and in particular reduces the amount of bacterial regrowth after 24 hours compared to either treatment alone (p<0.0001). j bagh college dentistry vol. 25(3), september 2013 evaluation of restorative dentistry 46 the present results are coincide with george and kishen 22 who found that when the biofilm was subjected to photoactivated disinfection using methylene blue dissolved in water, there was a difference of 1.5log10 in the mean viable count that corresponded to 96.89% reduction in viable bacteria compared with the control group. complete killing of bacteria was observed when the root canals were subjected to root canal treatment, photoactivated disinfection using (perfluorodecahydronaphthalene) oxygen carrier, and treatment comprising root canal treatment combined with photoactivated disinfection using oxygen carrier. photoactivated disinfection using oxygen carrier alone or in combination with conventional disinfection technique showed the absence of bacteria even after 24 hours of incubation, suggesting complete bacterial inactivation.. antibacterial efficiency of intracanal medicaments. formaldehyde containing compound achieved high percentage of bacterial reduction 95.4%.this conclusion agrees with the result of nunn et al 23 who stated that the formaldehyde has good and long distance antibacterial action permitting the vapor to reach the most distance places in root canal. formaldehyde containing compound possess antibacterial action superior to cmcp. tricresol formalin vapor action eradicated the microflora in necrotic root canal effectively, achieved high percentage of bacterial reduction 95%.this is very good result may be because presence formaldehyde in these compounds.24 the present study showed that the cmcp achieved high percentage of bacterial reduction 90.6%. al-huwaizi 24.found that cmcp gained a negative culture of 70% which indicated that its vapor antibacterial action is not as efficient as the formaldehyde containing compound. cmcp vapor action had mild antibacterial action on necrotic root canal. this results in agreement with our finding. tanriverdi et al 25 reported that the cmcp still better than calcium hydroxide, and they concluded that when cmcp used in the root canal the interappiontment time should not exceed the first 3 day. antibacterial action of cmcp was found to be more on the anaerobic than on aerobic bacteria. the present study showed that the calcium hydroxide achieved 83.4% percentage of bacterial reduction. this findings are in agreement with shuping et al 26 who stated that the addition of calcium hydroxide as an intracanal medication for at least 1 week produced 92.5% of canals void of bacteria. there was a statistically significant decrease in bacterial numbers between the final instrumentation samples and the samples taken after calcium hydroxide therapy. these results are coincide with athanassiadis in 200727 who found that the calcium hydroxide has been widely accepted as an intracanal medicament because of its antimicrobial properties, especially because of its action on gram-negative bacteria. a significant decrease in the number of cfus and the percentage of viable e. faecalis was observed after treatment with ca(oh)2. 28 references 1. siqueira jf jr, rocas in. clinical implications 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to eliminate root canal biofilm infection. lasers surg med 2007; 39:59-66. 22. george s, kishen a. influence of photosensitizer solvent on the mechanisms of light activated killing of enterococcus faecalis. photochem photobiol 2008; 84:734–40. 23. nunn jh, smeaton i, gilroy j. the development of formocresol as a medicament for primary molar pulpotomy procedures. asdc j dent child 1999; 63(1):51-3. 24. al-huwaizi h.f. the use of acetic acid as a new intracanal medicament, a bacteriological, histopathological, and clinical study. ph.d. thesis, college of dentistry. baghdad .2000. 25. tanriverdi f, esener t, erganis o, belli s. an in vitro test model for investigation of disinfection of dentinal tubules infected with enterococcus faeclis. braz dent j 1997; 8(2): 67-72. 26. shuping gb, orstavik d, sigurdsson a, trope m. reduction of intracanal bacteria using nickeltitanium rotary instrumentation and various medications. j endod. 2000; 26(12):751-5. 27. athanassiadis b, abbott pv, walsh lj .the use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodontics. aust endod j 2007; 52: s64–82. 28. delgado rj, gasparoto th, sipert cr, pinheiro cr, moraes ig, garcia rb, bramante cm, campanelli ap, bernardineli n.antimicrobial effects of calcium hydroxide and chlorhexidine on enterococcus faecalis. j endod 2010; 36(8):1389-93. table 1. the effect of fotosan, tricresol formalin, cmcp, ca(oh)2 and control groups on root canal bacteria values expressed in cfu×10³ groups state descriptive statistics mean s.d. s.e. group i fotosan before 47.92 7.39 2.13 after 30 second 1.75 0.75 0.22 after 7day 0.25 0.05 0.01 group ii tricresol formalin before 49.67 6.14 1.77 after 2.33 1.07 0.31 group iii cmcp before 46.33 7.04 2.03 after 4.33 0.98 0.28 group iv ca(oh)2 before 42.75 8.28 2.39 after 7.00 1.86 0.54 group v control group before 50.67 5.42 1.56 after 45.33 5.09 1.47 j bagh college dentistry vol. 25(3), september 2013 evaluation of restorative dentistry 48 table 2. percentage of reduction of bacteria count of groups. groups percentage of reduction group i fotosan 96.39 (30 s) 99.48 (7 d) group ii tricresol formalin 95.41 group iii cmcp 90.62 group iv ca(oh)2 83.44 group v control group 10.47 table 3. lsd test comparing the differences in mean bacteria count value after treatment between groups. groups mean difference p-value i after 30 s i after7d 1.500 0.118 (ns) ii -0.583 0.540 (ns) iii -2.583 0.008 ** iv -5.250 0.000 *** v -43.583 0.000 *** i after7 d ii -2.083 0.031 * iii -4.083 0.000 *** iv -6.750 0.000 *** v -45.083 0.000 *** ii iii -2.000 0.038 * iv -4.667 0.000 *** v -43.000 0.000 *** iii iv -2.667 0.006 ** v -41.000 0.000 *** iv v -38.333 0.000 *** *=significant **=highly significant ***=very highly significant 14. sarmad f.doc j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 90 an assessment of alpha-amylase as salivary psychological stress marker in relation to temporomandibular disorders among a sample of dental students sarmad qays ali, b.d.s. (1) raja hadi, b.d.s., m.sc., ph.d. (2) abstarct background: university dental students perceived a higher level of stress prior to the final exam associated with raised salivary alpha-amylase levels which could be considered as a useful noninvasive biomarker for measuring acute stress. using a helkimo anamnestic and clinical dysfunction scoring for temporomandibular disorders can give a better insight about the association of this marker and temporomandibular disorders. the aim of this study was to evaluation level of salivary alpha-amylase in stressor students with temporomandibular disorders and the relation between the marker in relation to temporomandibular disorders severity. this might give a better understanding to the role of psychological stress as an etiological factor for developing temporomandibular joint problems. materials and methods: a total eighty participants aged between 20 to 24 were recruited for this study. the participants were university dental students under graduate students at final examination period who were examined and gave saliva samples in final examination period. salivary assay kits as alpha-amylase was used to measure those variable and a helkimo anamnestic and clinical dysfunction scoring for temporomandibular disorders. results: the group of participants with stress and temporomandibular disorders showed significantly higher levels of salivary alpha-amylase than the control group, the salivary alpha-amylase has statistically non-significant correlation with helkimo anamnestic categories (di-i mild, di-ii moderate and di-iii severe. salivary alpha-amylase levels show non-significant and weak association with two categories of clinical dysfunction criteria in helkimo index system, which are muscle pain and temporomandibular joint pain on palpation. conclusion: this study concluded that university students perceived a high level of stress before the final examination. salivary alpha-amylase is now the stress biomarker that is most often used to measure acute stress. helkimo anamnestic and clinical dysfunction scoring criteria for still the pioneer for measuring a tmd. keywords: stress, alpha-amylase, helkimo, temporomandibular joint, temporomandibular disorders. (j bagh coll dentistry 2015; 27(4):90-95). introduction university students are liable to a higher level of stress especially in pre-examination period, if stress is prolonged, the stress response has two principal facets: the neuro-endocrine, which involves corticotropin-release hormone, activation of the hypothalamic-pituitary-adrenal axis and the secretion of cortisol into circulation. cortisol is then filtered through the acinar cell membrane of the salivary glands, and is found in saliva in the free unbound form. secondly, the stress response involves activation of the autonomic nervous system, release of catecholamines (e.g., plasma norepinephrine, pne), and sympatho-mimetic manifestations, such as increase salivation, and increase secretion of salivary alpha-amylase. salivary alpha-amylase levels increase under a variety of physical (i.e., exercise, heat and cold) and psychological (i.e., written examinations) challenges. salivary and plasma norepinephrine levels always correlate with each other following stress, confirming that the two pathways are the same (1). (1) master student. , department of oral diagnosis, college of dentistry, baghdad university. (2) professor, department of oral diagnosis, college of dentistry, baghdad university. temporomandibular joint dysfunction is a collective term covering pain and dysfunction of the muscles of mastication and the temporomandibular joints. the most important feature is pain, followed by restricted mandibular movement and noises from the temporomandibular joints (tmj) during jaw movement (2). although temporomandibular disorders (tmd) are not life threatening, it can be detrimental to quality of life (3) because the symptoms can become chronic and difficult to manage. usually people affected by tmd are between 20 and 40 years of age, and it is more common in females than males (4). the etiology of tmds is multifactorial, which is thought to be caused by multiple, poorly understood factors (5). but the exact etiology is unknown (6). there are factors which appear to predispose to tmd (genetic, hormonal, anatomical), factors which may precipitate it (trauma, occlusal changes, parafunction), and also factors which may prolong it (stress and again parafunction) (7). overall, 2 hypotheses have dominated research into the causes of tmd, namely a psychosocial model and a theory of occlusal disharmony (6). j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 91 oral habits or parafunctions, defined as any oral nonfunctional activity or behaviour involving the masticatory system, are neither uncommon nor are they always harmful (8). it is only when such activities exceed an individual’s physiologic tolerance that breakdown of the masticatory system may occur. in such cases the initial breakdown takes place in the tissue with the lowest structural tolerance in that particular individual, e.g. joints, teeth or muscles (9). oral habits or parafunctions have been reported to be common worldwide, with many students and adolescents performing them on a daily basis (10). oral habits include a variety of activities, such as continuous gum chewing, nail biting, and chewing on writing implements (pencils, pens). oral habits such as these are common among students, and they were shown to have a potentially detrimental effect on the masticatory system (11,12). saliva has been described as the mirror of the body. the wide spectrum of compounds present in saliva may provide information for clinical diagnostic applications. saliva is a good medium because its collection is noninvasive and the donation process is relatively stress free, so that multiple collections can be performed without imposing too much discomfort on the donor (13). amylase is an enzyme that catalyzes the hydrolysis of starch into sugars. amylase is present in the saliva of humans and some other mammals, where it begins the chemical process of digestion (14). salivary α-amylase has been used as a biomarker for stress that does not require a blood draw (15). recently, much attention has been given to possible interactions between stress and αamylase levels. however, significant psychosocial studies of α-amylase responsiveness are difficult due to the system's complexities. salivary αamylase (saa) is secreted by the parotid gland in response to adrenergic activity and is suppressed by β-adrenoreceptor blockade (16). it has also become established as a new biomarker of the psychosocial stress response within the sam system (17). studies show marked increases in saa levels in response to stressful tasks or procedures, such as a parachute jump or a stressful video game, as well as to other types of psychological (e.g. pre-examination) stressors (18). materials and methods the subjects: a total 80 participants age between 20 to 24 years were recruited for the present study. the participants were university dental students under graduate students at final examination period who were examined and gave saliva samples in final examination period. the participants in this study divided into two groups: • case group: sixty stressed students with temporomandibular disorders (tmd). • control group: twenty students without stress and temporomandibular disorders (tmd). inclusion criteria: 1-university dental students (20-24) years old from both genders with stress and temporomandibular disorders were included in the case group. the female students were in the luteal phase of menstrual cycle to be equal to male in the activity of hypothalamuspituitary-adrenal axis. 2-university dental students (18-30) years old from both genders without stress and temporomandibular disorders were included in the control group. exclusion criteria: 1. students with a history of use of corticosteroids in the past year. 2. students with a history of antidepressant medication. 3. students on hormone supplements including oral contraceptives at the time of saliva collection. 4. students with a history of head injury. 5. students with orthodontic treatment, occlusal disharmonies like cross bite and premature contact or dental pain. 6. those with muscle tenderness due to systemic diseases as fibromyalgia, neuralgia and local infection. 7. cases with more than 2 missing posterior teeth. materials: high sensitivity, salivary alpha-amylase enzyme immunoassay kits (uscn life science inc. wuhan, china). methods of examination: the participants examined according to helkimo anamnestic and clinical dysfunction index of temporomandibular disorders which consists of standardized series of diagnostic tests based on clinical signs and symptoms. statistical analysis: statistical analysis was computer aided. an expert statistical advice was sought for. statistical analyses were done using ibmspss version 21 computer software (statistical package for social j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 92 sciences). data were presented in measures of mean, standard deviations, range (minimummaximum values), median, frequency, percentages and predictive value. the significance in difference between the means (quantitative data) for two groups was tested using independent student t-test, while using analysis of variance (anova) for more than two groups. different percentages (qualitative data) were tested using chi-square test, pearson correlation was calculated for the correlation between two quantitative variables with its t-test for testing the significance of correlation. the correlation coefficient value (r) either positive (direct correlation) or negative (inverse correlation) with value <0.3 represent no correlation, 0.3-<0.5 represent weak correlation, 0.5-<0.7 moderate strength, >0.7 strong correlation. probability test (p value) was considered statistically significant when the p value < 0.05 and regarded as highly statistically significant when the p value < 0.001. results the data related to salivary alpha-amylase levels showed skewed distribution in case groups. therefore, comparison between case and control groups has been made using median and interquartile range to overcome the skewed data distribution. the group of participants with stress and tmd showed significantly higher levels of salivary amylase (median 494 with iqr 339-1016 ng/ml) than the control group (median 270 with iqr of 89-313 ng/ml) as shown in table 1. the predictive value measurements for salivary alpha-amylase showed highly positive predictive value (ppv) at 50% and 90% levels with the cut-off point of (314) ng/ml. this point can be used as biomarker reference value for the salivary alpha-amylase for accurate prediction of stress and tmd (accuracy 84.8%). statistical analysis did not show any correlation of salivary alpha-amylase with helkimo clinical dysfunction score of tmj expressed by nonsignificant p value of 0.85 and approximately similar medians (500, 488, and 499 ng/ml) among all categories of helkimo anamnestic categories (di-i, di-ii and di-iii) as shown in table 2. association analysis of salivary alpha amylase level with clinical criteria of helkimo clinical dysfunction index shows no association with any criteria whether mobility related or pain related. the p value was non-significant throughout all the clinical criteria categories as seen in table 3. the distribution percentage of varying oral habits in tmd students was shown in table 4. table (1): the salivary alpha-amylase levels in the case and control groups. (measurements are in ng/ml and p<0.001). salivary alpha amylase (u/ml) study groups p control cases with stress range 26-489 217-1992 <0.001 median 270 494 inter-quartile range 89-313 339-1016 n 19 60 mean rank 15.5 47.8 table (2): association of salivary alpha amylase levels with helkimo anamnestic categories of tmd. p helkimo clinical dysfunction index salivary alpha amylase (u/ml) (10–25) di-iii (severe dysfunction) (5–9) di-ii (moderate dysfunction) (1–4) di-i (mild dysfunction) 0.85 (ns) 363-591 287-1854 217-1992 range 499 488 500 median 363-591 385-1173 319-1016 inter-quartile range 3 13 44 n 28.7 32.8 29.9 mean rank r=0.021, p=0.87 (ns) j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 93 table (3): association of salivary amylase levels with individual clinical criteria used in helkimo index for tmj dysfunction. salivary amylase (u/ml) range median inter-quartile range n mean rank p gender 0.83 (ns) female 287-1920 510 361-672 30 30 male 217-1992 442 320-1438 30 31 mandibular mobility (opening, laterotrusive, protrusive) 0.84 (ns) normal range of movement 217-1992 500 319-1016 40 30.2 slightly impaired mobility 281-1854 494 352-918 20 31.2 severely impaired mobility ** ** ** 0 ** r=0.027 p=0.84[ns] symptom: impaired tmj function 0.73 (ns) smooth movement without tmj sounds and deviation on opening or closing movement <2 mm 315-1992 490 354-1576 16 33.4 sounds in 1 or both joints and/or deviation >2 mm on opening or closing movements 217-1891 494 323-983 42 29.5 locking/and/or luxation of the tmj 363-591 477 363-591 2 27.5 r=-0.104 p=0.43[ns] symptoms: masseter pain 0.68 (ns) no tenderness to palpation in masticatory muscles 285-1048 554 347-804 8 29.2 tenderness to palpation in 1-3 palpation sites 217-1992 488 331-1245 47 31.4 tenderness to palpation in > 4 palpation sites 323-591 385 363-499 5 24.4 r=-0.039 p=0.77 (ns) symptoms: tmj pain 0.89 (ns) no tenderness to palpation 217-1992 536 320-983 29 30.2 tenderness to palpation laterally 281-1891 488 352-1173 31 30.8 tenderness to palpation posteriorly ** ** ** 0 ** r=0.018, p=0.89 (ns) symptom: pain on movement of the mandible 0.57 (ns) no pain on movement 256-1992 382 299-1438 22 27.5 pain on 1 movement 217-1891 488 385-983 33 32 pain on > 2 movements 363-1228 591 499-598 5 34.2 r=0.138 p=0.29[ns] table (4): the distribution percentage of varying oral habits in tmd students. % n oral habits 20.0 12 non 28.3 17 clenching 8.3 5 grinding 6.7 4 biting nail 21.7 13 bruxism 15.0 9 chewing 100.0 60 total j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 94 discussion educational literature has reported the experience of stress in students and provides evidence that stress impairs academic performance(19-21). previous investigations analyzing physiologic responses to stress and performance have examined changes in heart rate, blood pressure, the presence of perspiration, and plasma catecholamine levels (15,22,23). the measurement of salivary alpha-amylase, a valid and highly reliable method to measure the physiologic response to acute stress, has been incorporated into a multitude of biobehavioral research studies (15,24). salivary alpha-amylase is a major secretory protein found in saliva and aids in the initial digestion of starch (25,26). release of salivary alpha-amylase is regulated by autonomic innervation (17). sympathetic stimulation causes high salivary α-amylase release from the parotid and submandibular acinar cells, whereas parasympathetic stimulation causes low salivary α-amylase release from the sublingual acinar cells (25). recent investigations in academic students before examinations have demonstrated that salivary alpha-amylase levels significantly increase as a result of acute stress (23,24,27-29). these recent investigations have an agreement with this study which concluded that there is a highly significant levels of salivary alpha-amylase in stress group with tmd than control one. in 1997 chatterton and colleagues linked levels of salivary αamylase to sympathetic activation during physically and psychologically stressful conditions (30). for purpose of the present study it was found that the level of salivary αamylase was observed to increase significantly in an investigation that used university students before the written examinations as a psychological stressor. despite the skewed data of salivary alphaamylase in case group due to small sample size, the comparison between the case and control group using the median and inter-quartile range (iqr) showed the highly significant evidence of possible use of salivary alpha-amylase as alternative indicator or in conjunction with cortisol as biomarkers for assessing the stress with tmd (31). the predictive value measurements for salivary alpha-amylase showed highly positive predictive value (ppv) at 50% and 90% levels with the cut-off point of (314) ng/ml. this point can be used as biomarker reference value for the salivary alpha-amylase for accurate prediction of stress and tmd (accuracy 84.8%). association analysis of salivary alpha amylase level with clinical criteria of helkimo clinical dysfunction index shows no association with any criteria whether mobility related or pain related. the p value was non-significant throughout all the clinical criteria categories. therefore the higher levels of salivary alpha-amylase in tmd indicating that participants have a problem with stress or tmj problems but this biomarker have no any association neither severity nor clinical dysfunction criteria of helkimo. as conclusion; the present study demonstrated that salivary alpha-amylase can be used as a stress predictive biomarker to assess the tmj problems due to psychological stress in university students. references 1. isogawa k, tsuru j, tanaka y, ishitobi y, ando t, et al. association between salivary amylase, cortisol and stress. handbook of neuropsychiatry research 2010; 113–123. 2. mujakperuo hr, 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26. turner rj, sugiya h. understanding salivary fluid and protein secretion. oral dis 2002; 8(1): 3-11. 27. fisher sz, govindasamy l, tu c, et al. structure of human salivary alpha-amylase crystallized in a ccentered monoclinic space group. acta crystallogr sect f struct biol cryst commun 2006; 62(pt 2): 8893 28. rohleder n, nater um, wolf, jm, ehlert u, kirschbaum c. psychosocial stressinduced activation of salivary alpha-amylase: an indicator of sympathetic activity? ann n y acad sci 2004; 1032: 258–63. 29. nater um, la marca r, florin l, moses a, langhas w, et al. stress-induced changes in human salivary alpha-amylase activity-associations with adrenergic activity psychoneuroendocrinol 2006; 31: 49–58 30. ehlert u, erni k, hebisalivary cortisolh g, nater u. salivary alpha-amylase levels after yohimbine challenge in healthy men. j clin endocrinol metab 2006; 91: 5130–3 31. chatterton rt jr, vogelsong km, lu yc, ellman ab, hudges ga. salivary alpha-amylase as a measure of endogenous adrenergic activity. clin physiol 1997; 16: 433–48. 32. engert v, vogel s, efanov is, duchesne a, corbo v, et al. investigation into the cross-correlation of salivary cortisol and alpha-amylase responses to psychological stress. psychoneuroendocrinol 2011; 36: 1294–302. microsoft word 3 omar ibrahim j bagh college dentistry vol. 32(3), september 2020 salivary mucoepidermoid 14 salivary mucoepidermoid carcinoma, auclair vs brandwein grading system: a histopathological comparative study omar i. ahmed (1), lehadh m. al-azzawi (2) article doi: https://doi.org/10.26477/jbcd.v32i3.2895 abstract background: the grading systems of salivary mucoepidermoid carcinoma depend on different histologic and morphologic features. the aim of this study was to compare between auclair and brandwein systems according to their histologic criteria, and the type of cell predominant. materials and methods: twenty-one case included hematoxylin-eosin (h&e) stained tissue slides that were diagnosed as mec, originally categorized into low and high grade type regardless of the grading system, have meticulously undergone histopathologic review. the sample was graded according to criteria owing to auclair and brandwein methods. the predominant type of cells was determined by microscopic examination according to grade of tumor. results: regarding the auclair method, 10 cases (47.6%) were low grade tumor, 11 cases (52.2%) were high grade type and none of them were intermediate type. by using brandwein system for the same sample, 4 cases (19%) were low grade, 13 cases (61%) were a high grade tumor, and 4 cases (19%) were intermediate type. even though, for both systems more than 35% of cases were predominated with epidermoid cells, and <15% showed mucous and intermediate cell predominance for each, whereas >30% were exhibited a mixed type of tumor cells. however, there was a significant correlation between the grading systems applied and the type of cell predominance (p-value <0.05). conclusion: the number of cases distributed according to brandwein system was increased as the level of histologic grade being raised, and the type of cells, which are relatively predominant, may be valuable in determining the histologic grade of tumors. keyword: mucoepidermoid carcinoma (mec), auclair system, brandwein system. (received: 2/10/2017; accepted: 20/11/2017). introduction salivary gland carcinomas (sgcs) are rare malignant tumors with overall incidence ranged internationally from 0.4-2.6 cases/1000,000 population per year and comprise only 3-5% of all malignant neoplasms of head and neck.(1) these tumors are morphologically diverse and as yet, at least 24 different types were recognized by world health organization (who).(2) mucoepidermoid carcinoma (mec) is one of the highlighted entities of salivary gland malignancy and is histologically composed of mixture of mucous-producing cells, intermediate cells and epidermoid (squamous) cells; in different proportions which usually determine the grade of tumor, in addition to clear cells, oncocytic and columnar cells.(3) regarding their histopathological diagnoses, mecs can be classified into low-, intermediate-, and high-grade subtypes according to the amount of cystic components; degree of cellular and nuclear atypia; and relative numbers of different cell types.(4) in fact, the most popular grading systems of mec are: the armed force institution of pathology (afip) suggested by auclair et al.(1991) and brandwein et al.(2001). (1) assistant lecturer, department of dentistry, bilad al – rafidain university, diyala -iraq. (2) assistant professor, department of dentistry, al–hikma university college, baghdad -iraq. corresponding author, okok54321okok@gmail.com these systems are designated as 3-levels and exhibit best reproducibility among the pathologists, although the criteria proposed for such systems are still under debate.(5,6) both systems are custom-built and numericallybased schemes with different points reflecting the quantitative values assigned for each histologic parameter.(7-9) however, the histologic criteria in both systems are weighted according to the magnitude of its significance with ascending point scores equivalent to a higher grade.(10) the grading stystems of mecs have revealed some flaws, unlikely they are troubling, timeconsuming and somewhat the histologic criteria are not well-defined.(5,6,11)as noted, all systems appeared to be a good prognostic indicator even independent on tnm staging, as well as the way of correlation between each syatem and clinical outcome is quite variable and several studies indicated that the brandwein system appears to ‘up-grade’ tumors, whereas the afip system appears to ‘down-grade’ tumors. accordingly, the proper treatment and the prediction of patient’s outcome may be more difficult due to these variations.(1) this study aims to compare between auclair and brandwein systems according to their histologic criteria, and the type of cell predominant. j bagh college dentistry vol. 32(3), september 2020 salivary mucoepidermoid 15 materials and methods the materials of this study consisted of twentyone formalin-fixed, paraffin-embedded (ffpe) specimens of salivary mec, all collected from archives of the oral diagnosis department /college of dentistry/university of baghdad, and from the department of specialized surgery/al-shaheed ghazi hospital/ baghdad. the clinical information was obtained from the patient’s medical records, including age, gender, tumor site and nodal involvement. all the cases were histologically diagnosed by two specialists, pathologists, who were both blinded from the patients’ clinical data. approximately 4 µm thick sections were prepared and stained with hematoxylin and eosin (h&e) stain to confirm the diagnosis. all tumors were reviewed and graded according to the criteria of the point-based methods for both auclair and brandwein, respectively, (table 1) and (figure.1). eventually, comparison of the two grading systems has been achieved according to their own histologic parameters. the correlation between cell types predominance and the grade of tumor was statistically analyzed by using the chi-square test. table 1: comparison of the two point -based grading system of mucoepidermoid carcinoma. afip system points brandwein system points intracystic component <20% 2 intracystic component<25% 2 neural invasion present 2 tumor invades in small nests and islands 2 necrosis present 3 pronounced nuclear atypia 2 mitosis (4 or more per 10 hpf*) 3 lymphatic and/or vascular invasion 3 anaplasia 4 bony invasion 3 grade score more than 4mitoses per 10 hpf 3 low grade 0-4 intermediate grade 5-6 perineural spread 3 necrosis 3 high grade 7-14 grade score grade i 0 grade ii 2-3 grade iii >4 * high power field figure 1: (h&e) stained sections of salivary mec, a, low grade tumor with macrocystic spaces, lined with mucous, squamous cells and intermediate cells, and containing mucous secretion (10x). b, intermediate grade tumor with fewer cystic component, more solid area with predominance of intermediate cells (10x). c, high grade mec showed more nuclear atypia and mitosis > 4 per 10 hpf, (40x). d, demonstrate foci of necrosis with lymphocyte infiltration (20x). e, aggressive pattern of tumor infiltration; tumor is invaded by a small islands of tumor cells (leading-edege infiltration), which are the defining feature of grade ii and iii, according to brandwein system (20x). f, high grade tumor with perineural invasion, tumor cells invading the soft tissue surrounding the involved nerve (10x). a b c d e f j bagh college dentistry vol. 32(3), september 2020 salivary mucoepidermoid 16 results altogether, 21 cases of mec were reviewed according to the auclair grading system. the cases were classified as follow: 47.6% (10/21) were low grade tumors and 52% (11/21) were high grade type, whereas no case in this series was an intermediate type (table 2). regarding the brandwein system, the cases were 19% (4/21) for grade i tumor, whereas grade ii and iii tumors constituted about 19% (4/21) and 61.9% (13/21), respectively (table 3). regarding the type of cells that mainly predominated in the tumor, the distribution of cases was as follows: 14.2%, 38% and 14.2% of mucous-producing cells, squamous cells and intermediate cells predominate, respectively, and the remaining 33.3% were a mixed type of cells (table 4) and (fig 2). it was found that the type of tumor cell predominant was significantly correlated with both systems, according to chi square test (p-value for auclair and brandwein systems was 0.006 and 0.029, respectively). table 3: case distribution according to brandwein grading system. table2: case distribution according to the auclair grading system. table 4: cases distribution according to predominated type of tumor cells. criteria point s score no. of cases intracystic components < 25% 2 < 25 % >25 % 12 9 pronounced nuclear atypia 2 -ve +ve 8 13 tumor front invades in small nests and island 2 -ve +ve 7 14 lymphatic&vascular invasion 3 -ve +ve 21 0 bony invasion 3 -ve +ve 20 1 greater than 4 mitosis per 10 hpf 3 -ve +ve 9 12 perineural spread 3 -ve +ve 17 4 necrosis 3 -ve +ve 10 11 grade total grade of study i 0 4 (19%) ii 2-3 4 (19%) iii >4 13 (61.9%) criteria points score no. of cases intracystic component < 20 % 2 < 20% > 20% 12 9 neural invasion 2 -ve +ve 17 4 necrosis 3 -ve +ve 10 11 four or more mitosis per10 hpf 3 -ve +ve 9 12 anaplasia 4 -ve +ve 8 13 grade total points score low 0 – 4 10 (47.6%) intermediate 5 – 6 0 (0.0%) high 7 – 14 11(52.4%) a: auclair grade b: brandwein grade predominate cells mucous squamous intermediate mixed total low a 3 (14.2%) 2 (9.5%) 5 (23.8%) 10 (47.6%) b 2 (9.5%) 2 (9.5%) 4 (19.0%) intermediate a b 1 (4.7%) 3 (14.2%) 4 (19.0%) high a 8 (38.0%) 1 (9.5%) 2 (9.5%) 11 (52.3%) b 1 (9.5%) 8 (38.0%) 2 (9.5%) 2 (9.5%) 13 (61.%) a 3 (14.2%) 8 (38.0%) 3 (14.2%) 7 (33.3%) 21 total b 3 (14.2%) 8 (38.0%) 3 (14.2%) 7 (33.3%) 21 test chi square test for predominant cells with auclair/p value= 0.006 chi square test for predominant cells with brandwein /p value = 0.029 j bagh college dentistry vol. 32(3), september 2020 salivary mucoepidermoid 17 (a) (b) figure 2: distribution of cases, according to type of cell predominance, with regard to (a) auclair (b) brandwein system. discussion salivary gland neoplasms are relatively rare and a morphologically diverse group of lesions. diagnosis based on (h&e) stained sections remains the gold standard in salivary gland pathology.(14) in the present study, the cases were categorized into low, intermediate and high grade according to criteria of auclair and brandwein schemes. in general, the distribution of the number of mec cases, in most epidemiologic studies, was inversely related to the level of the histologic grade.(15,16,17) in this study, according to auclair system, we found that little difference, concerning cases distribution between low and high grade tumors (table 2). correspondingly, from data of (table 3) which presents the distribution of cases according to brandwein system, it is apparent that the number of distributed cases is increased as the level of histologic grade being raised and this in accordance with other documented reports.(18,19,20) mecs are histologically heterogeneous tumors with various degrees of cells differentiation, including mainly mucous-secretory cells, small basaloid type (intermediate) cells and epidermoid (squamous) cells, in addition to other cell types, and usually these cells may be proportionally present in the tumor or exhibiting a predominant sorts.(20, 21) in this study, we found that the cell types predominance were significantly correlated with histologic grading systems (p-value appeared to be <0.05) and more squamous cell count were detected in a high grade type, irrespective to the grading system, as illustrated in (figure 2), thus this was in agreement with results from other researches.(3,20,21) finally, the results of this study confirm previous observations that there is a difference in cases distribution relevant to the level of histologic grade of tumor which is usually determined by the grading system used, or by counting type of cells that relatively or predominantly constituted the bulk of tumor. conclusion according to the criteria proposed by brandwein method, which has been approved in this study, the number of cases was increased as the level of histologic grade being raised. regarding the predominant cells in the tumor, this feature was relatively valuable in determining the histologic grade of the mucoepidermiod carcinoma regardless of the grading system that is applied. conflict of interest: none. references 1. eveson jw, auclair pl, gnepp dr. tumors of the salivary glands: introduction. in: barnes el, eveson jw, reichart p, sidransky d, editors. world health organization classification of tumours: pathology & genetics. head and neck tumours. lyon: iarcpress; 2005. p. 221–2. 2. luukkaa h. salivary gland cancer in filand incedence, histologic distribution ,outcome and prognostic factors. acadimic dissertation, university of turku . filand , 2010. p 53. 3. luna ma. salivary mucoepidermoid carcinoma: revisited. adv anat pathol. 2006;13:293–307. 4. neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology; salivary gland pathology, fourth edition, saunders, usa (2016). 5. seethala rr, hoschar ap, bennett a. reproducibility of grading in salivary gland mucoepidermoid carcinoma and correlation with outcome: does system really matter? mod pathol. 2008; 21(1):241a. 6. seethala rr. histologic grading and prognostic biomarkers in salivary gland carcinomas. adv anat pathol. 2011;18:29–45. 7. auclair pl, goode rk, ellis gl. mucoepidermoid carcinoma of intraoral salivary glands evaluation and application of grading criteria in 143 cases. cancer 1992 ; 69(8) :2021-30. 8. goode rk, auclair pl, ellis gl. mucoepidermoid carcinoma of the major salivary glands: clinical and histopathologic analysis of 234 cases with evaluation of grading criteria. cancer. 1998; 82(7):1217–24. 9. brandwein ms, ivanov k, wallace di. mucoepidermoid carcinoma: a clinicopathologic study 0 2 4 6 8 n o . o f ca se s low grade intermediate grade high grade 0 2 4 6 8 n o .o f ca se s low grade intermediate grade high grade j bagh college dentistry vol. 32(3), september 2020 salivary mucoepidermoid 18 of 80 patients with special reference to histological grading. am j surg pathol 2001;25 (2): 835–45. 10. gnepp d, allen cm, bouquot je, eveson j. diagnostic surgical pathology. 2nd edition, saunders, an imprint of elsevier inc. usa, 2009. 11. katabi a, ghossein r, ali s, dogan s, klimstra d, ganly i. prognostic features in mucoepidermoid carcinoma of major salivary glands with emphasis on tumour histologic grading. histopath. 2014; 65, 793– 804. 12. nance ma, seethala rr, wang y. treatment and survival outcomes based on histologic grading in patients with head and neck mucoepidermoid carcinoma. cancer 2008; 113; 2082-89. 13. aro k, leivo i, makitie aa. management and outcome of patients with mucoepidermoid carcinoma of major salivary gland origin: a single institution’s 30-year experience. laryng. 2008; (118)1: 258-62. 14. speight, barret. salivary gland tumors. oral dis. 2002;8;229-40. 15. vedrine po, coffinet l, temam s, montagne k, lapeyre m, oberlin o, orbach d, simon c, et al. mucoepidermoid carcinoma of salivary glands in the pediatric age group: 18 clinical cases, including 11 second malignant neoplasms. head neck. 2006; 28:827-33. 16. rapidis ad, givalos n, gakiopoulou h, stavrianos sd, faratzis g, lagogiannis ga, katsilieris i. patsouris e. mucoepidermoid carcinoma of the salivary glands. review of the literature and clinicopathological analysis of 18 patients. oral oncol. 2007;43:130-36. 17. schwarz s, stiegler c, muller m, ettl t, brockhoff g, zenk j, agaimy a. salivary gland mucoepidermoid carcinoma is a clinically, morphologically and genetically heterogeneous entity: a clinicopathological study of 40 cases with emphasis on grading, histological variants and presence of the t(11;19) translocation. histopath. 2011;58:557-70. 18. janet o, canales g, morales-vadillo r, guillermo guzmn-arias, carlos e, cava-vergiu, guerra-miller h, jaime e. montes-gil. mucoepidemoid carcinoma of the salivary gland. a retrospective study of 51cases and review of the literature. acta odontol latinoam. 2016; 29 (3):230-38. 19. al-azzawi l, ghazi o, hussein w. immunohistochemical expression of cyclin d1 in mucoepidermoid and adenoid cystic carcinoma of the salivary glands. j bagh coll dentistry. 2015;27(3):649. 20. ahmed o, al-azzawi l. mta1 expression in salivary mucoepidermoid carcinoma: with special emphasis on grading systems. journal of international dent med res. 2019;12(4): 1253-57. 21. barnes l. diseases of the salivary glands. surgical pathology of the head and neck.3rd edition, new york, informa, usa 2009, 475-648. مستخلصال غير ة الخبيثة والذي يتكون نسيجيا من خليط الغدد اللعابي اورام خاطي الحرشفي احد اكثر االنواع شيوعا بين ميعتبرالسرطان ال : الخلفية المخا الخاليا من نظام التصنيف للسرطان المخاطي طمتجانس يعتمد حيث والخاليا الحرشفية بالقاعدية والخاليا المتوسطة الشبيه ية ية على خصائص نسيجية وشكلية مختلفة . والهدف من هذه الدراسة هو المقارنة بين نظامي أوكليروبراندوين طبقا الحرشفي للغدد اللعاب .السائدة للمعايير النسيجية ونوع الخاليا التي تم النسيجية الشرائح فحص حالة تم تشخيصها كسرطان مخاطي حرشفي عن طريق 21شملت هذه الدراسة :المواد وطرق العمل لها. ي لمستخدم بعد مراجعة الفحص النسيجي المرضاعن نظام التصنيف الواطئة والعالية بغض النظر تصنيفها باالصل الى الدرجتين بعد ذلك تم تصنيف العينة طبقا للمعايير الخاصة بنظامي التصنيف أوكلير وبراندوين. تم تحديد نوع الخاليا السائدة بواسطة التشخيص ة الورم. المجهري طبقا لدرج )52.2حالة (%11كانت ذات درجة واطئة و )%47.6حاالت (10ن أحسب نظام أوكلير : اظهرت نتائج الفحص المجهريالنتائج ) بدرجة واطئة 19حاالت (% 4نظام براندوين لنفس العينة كان هنالك ولم يكن من ضمن العينة ورم من الدرجة المتوسطة. وباستخدام من الحاالت 35) بدرجة متوسطة. ولكال النظامين اظهرت الدراسة ان اكثر من %19حاالت (% 4عالية , ) بدرجة61حالة (13%, من الحاالت نوع مختلط من 30خاليا مخاطية ومتوسطة بينماااظهرت اكثر من % 15واقل من % كانت الخاليا الحرشفية هي السائدة و ). p<0.05انظمة التصنيف المطبقة ونوع الخاليا السائدة ( الخاليا. اظهرت الدراسة وجود عالقة مهمة بين المرضية ونوع الخاليا عدد الحاالت الموزعة طبقا لنظام براندوين كانت في تزايد بسبب ازدياد مستوى الدرجة النسيجيةاالستنتاجات : السائدة والتي ربما تكون ذات قيمة في تحديد الدرجة النسيجية للورم. j bagh college dentistry vol. 28(4), december 2016 comparison of pedodontics, orthodontics and preventive dentistry 172 comparison of bolton’s ratios in a sample of iraqi and egyptian populations munad j. al-duliamy, b.d.s., m.sc. (a) samer s. othman, b.d.s., m.sc. (b) farouk a. hussien, b.d.s., m.sc., phd. (c) abstract background: the objective of this study was to investigate the possibility of standardizing the bolton ratio analysis as a diagnostic measure for both iraqi and egyptian orthodontic populations within three angle' classification groups. materials and methods: two hundred forty pretreatment study casts (one hundred twenty of each population) were included in this study and divided into three angle' classification groups. the mesiodistal crown diameters of all teeth were measured for computing the anterior and total bolton ratios. analysis of variance was performed to compare the mean ratios of bolton analysis as a function of the angle classification.hsd test was used to specify the classes of malocclusion that have significant differences. results: no statistically significant differences were determined in the mean values of the anterior ratio among the angle classification groups in both iraqi and egyptian populations. no statistically significant differences were determined in the mean values of the overall ratio among the angle classification groups in iraqi population. while there were statistically significant differences in the mean values of overall ratio among the angle classification groups in egyptian population. this difference is specified with in class ii malocclusion of egyptian population. conclusion: anterior bolton ratio can be standardized for both iraqi and egyptian orthodontic populations. while the overall ratio can be standardized only in class i and iii malocclusions of both populations. key words: bolton's ratio, iraqi, egyptian, orthodontic population. (j bagh coll dentistry 2016; 28(4):172-175) introduction tooth-size discrepancies are seen more frequently in subjects with malocclusions (1). bolton investigated the relationship between the mesiodistal crown diameters of the upper and lower teeth and developed an analysis. for evaluation of the two sets of 12 opposing teeth, the term ‘overall ratio’ is used and for the two sets of six anterior teeth, the term ‘anterior ratio’. bolton stated that for a good interdigitation and occlusion, overall ratio should be 91.3 ± 1.91 and anterior ratio 77.2 ± 1.65 (2). many patients presenting for orthodontic treatment have a bolton tooth-size discrepancy (3) that may highly influence proper interdigitation, overbite, overjet and alignment of the teeth (4). identifying such discrepancies before final tooth alignment should prove beneficial in defining the final expectations of both the clinician and the patient (5). therefore it would seem prudent for clinicians to routinely include bolton analysis in their treatment planning. although such an analysis may be time-consuming, the benefits of interproximal stripping to correct any discrepancies would seem to outweigh the minor inconvenience of performing the analysis, which should allow more efficient diagnosis of problems, more specificity in treatment planning and a higher success rate in achieving optimal (a) lecturer. department of pop, college of dentistry, almustansiria university. (b) assistant lecturer, college of dentistry, ibin sina university (c) assistant professor, department of pop, college of dentistry, al-azhar university functional, stable and esthetically pleasing occlusions (3). the reduction of tooth structure either by extraction or interdental reduction, or the addition to tooth structure by restorative technique is determined by the amount and location of bolton tooth-size discrepancy (4). bolton’s analysis has been investigated in different racial groups and populations. a limited number of studies in malocclusion groups have been undertaken, but their results were contradictory (6). size and shape of the dental arch can vary among different racial groups (7,8). different ethnic groups may have a different bolton ratio (9). these differences may complicate the orthodontic treatment. hence the professionals must be prepared to attend individuals from different ethnicities and be capable to anticipate these differences, establishing a more personalized treatment (8). on the other hand a significant difference was found for intermaxillary tooth size ratios among different malocclusion groups (10). therefore the present study aimed to calculate bolton’s overall and anterior ratios in iraqi and egyptian orthodontic populations within three angle's classes of malocclusion. materials and methods the sample for this study consisted of two hundred forty pretreatment study casts (one hundred twenty of each population) selected from the archive of the orthodontics department of both college of dentistrybaghdad university and faculty of dental medicineal-azhar university. j bagh college dentistry vol. 28(4), december 2016 comparison of pedodontics, orthodontics and preventive dentistry 173 the sample has been fulfilled the following criteria:  study casts of orthodontic patients aged between 13 and 25 years.  all permanent teeth erupted and present except for third molars.  study casts of good quality, with absence of fractured, deformed and large restored tooth. the sample was divided into three groups:  group 1 with angle class i malocclusion (n=70) for each population  group 2 with angle class ii malocclusion (n=40) for each population  group 3 with angle class iii malocclusion (n=10) for each population. the mesiodistal crown diameters of all teeth were measured with electronic digital caliper (china) accurate to 0.01mm.each measurement was recorded at the 0.01mm, with the anterior 3-3 and total 6-6 sums recorded at the 0.1mm level. the measurements were done by two well-trained orthodontists according to the method described by moorrees et al. (11), i.e. from the mesial contact point to the distal contact point at the greatest interproximal distance. bolton's anterior (canine to the canine) and overall (first molar to first molar) ratios were calculated for each model with the following formulas: (sum mandibular 12/sum maxillary 12) × 100 = overall ratio (%) (sum mandibular 6/sum maxillary 6) × 100 = anterior ratio (%) the measurements were then used to compute the anterior and total bolton ratios. data was analyzed using spss program. mean and standard deviation values were calculated for anterior and total bolton ratios for three angle classifications in both iraqi and egyptian population. anova was used to compare the anterior and total bolton ratios for each population with bolton’s standards with in each malocclusion group. tukey’s honestly significant difference (hsd) test was used to specify the classes of malocclusion that have significant differences. results the means and standard deviation values of both ratios in each angle classification are summarized in table 1 for both iraqi and egyptian populations. comparison among the classes and between the population are presented in tables 2-5. table 1: descriptive statistics for each ratio and class in iraqi and egyptian populations occlusion ratio population mean s.d class i anterior iraqi 78.72 4.53 egyptian 78.85 2.79 over all iraqi 91.23 2.2 egyptian 91.63 2.58 class ii anterior iraqi 79.05 2.64 egyptian 78.46 3.97 over all iraqi 91.54 2.66 egyptian 89.14 5.13 class iii anterior iraqi 78.8 2.15 egyptian 78.65 4.2 over all iraqi 91.82 2.24 egyptian 90.65 3.71 table 2: population difference for anterior ratio with in each class occlusion population t-test d.f. pvalue class i iraqi -0.193 123 0.848 (ns) egyptian class ii iraqi 0.739 71 0.462 (ns) egyptian class iii iraqi 0.093 17 0.927 (ns) egyptian table 3: population difference for overall ratio with in each class occlusion population t-test d.f. pvalue class i iraqi -0.940 123 0.349 (ns) egyptian class ii iraqi 2.425 71 0.018 (s) egyptian class iii iraqi 0.791 17 0.440 (ns) egyptian table 4: classes' difference for each ratio and population population ratio occlusion classes difference f-test p-value iraqi anterior i 0.080 0.923 (ns) ii iii over all i 0.343 0.711 (ns) ii iii egyptian anterior i 0.159 0.853 (ns) ii iii over all i 4.999 0.008 (hs) ii iii j bagh college dentistry vol. 28(4), december 2016 comparison of pedodontics, orthodontics and preventive dentistry 174 table 5: differences between the angle classes of egyptian population for overall ratio and their levels of significance determined by tukey’s honestly significant difference analysis. discussion bolton’s analysis of overall and anterior teeth is the most frequently used analysis in both clinical orthodontics and scientific studies when evaluating the correspondence between maxillary and mandibular mesiodistal width of teeth. this analysis influenced examination of orthodontic patient and planning of orthodontic treatment, and is still used to this day (12). therefore it is necessary to calculate bolton’s ratios in orthodontic patients (13). according to ta et al. (14); uysal and sari (15) and endo et al. (16), it is necessary to determine specific standards, for different populations as well as for different malocclusions (13).therefore in the present study bolton overall and anterior ratios were measured for angle class i, class ii, and class iii malocclusions in both iraqi and egyptian orthodontic populations. different results have been proposed in literature concerning the relationship between the malocclusion classes and the tooth size ratios. however no study was compare this relationship between iraqi and egyptian populations. according to the present study, there were no significant differences in both anterior and overall ratios among the angle classification groups of iraqi population. this in consistent with sulaimani andafify (17) who concluded that there is no significant difference in bolton anterior and overall ratios between class i, class ii, and class iii malocclusions in saudi arabian sample. this accordingly comes in agreement with the results of o'mahony et al. (18) which concluded that, there were no statistically significant differences in the prevalence of mean overall tooth size discrepancies with regard to malocclusion. moreover the current results were in accordance with basarana et al. (19) and al-khateeba and elham (20) who found no statistically significant difference between the relationship of the first permanent molars according to angle's classification and the value of the bolton ratio. regarding egyptian population there were no significant differences in the anterior ratio among the angle classification groups while there were statistically significant differences in the mean values of overall ratio among the angle classification groups. this is in consistent with the result of richardson and malhotra (21) who reported that there is a higher overall ratio on african population. also this may be explained by the result of fernandes et al. (22) who found that there is a tendency for african to present greater mesiodistal distance of teeth. the significant difference in overall ratio in egyptian population is specified within class ii malocclusion group. this may be due to high frequency of tooth size discrepancy among patients with class ii malocclusion according to the result of naseh et al. (23) the possible reason for these different results in the overall bolton ratio in class ii malocclusion between the two populations may be ethnic or racial because according to lavelle(24) tooth sizes show considerable variation in different racial categories. in conclusion;  in iraqi orthodontic sample, the comparison of overall and anterior bolton ratio revealed no statistically significant difference within angle class i, ii, and iii malocclusions.  in egyptian orthodontic sample, there were no statistically significant differences in the anterior ratio within angle class i, ii, and iii malocclusions while there were statistically significant differences in the overall ratio among the three malocclusion classes. the difference was within angle class ii malocclusion group. acknoledgment special thanks to the faculty members of the orthodontic department of the college of dentistry at baghdad university especially the chairman of the department professor dr. nidhal h. ghaib, assistant prof. dr. eman al-shaikhly and assistant prof dr. mohammed nahidh, for their cooperation in sample selection of this study. references 1. baydaş b, oktay h, metin dagsuyu i. the effect of heritability on bolton tooth-size discrepancy. eur j orthod 2005; 27: 98-102. 2. hyder ml, fcps, mamun msa, fcps, hossain mz. tooth size discrepancies among different population ratio occlusion mean difference p-value egyptian over all i ii 2.49 0.006 (hs) iii 0.988 0.713 (ns) ii iii -1.50 0.482 (ns) j bagh college dentistry vol. 28(4), december 2016 comparison of pedodontics, orthodontics and preventive dentistry 175 malocclusions in a bangladeshi orthodontic population. bangladesh j orthodontics and dentofacial orthop 2012; 2(2): 8-17. 3. rossouw pe, tortorella a. enamel reduction procedures in orthodontic treatment. j canad dent assoc 2003; 69: 378–83 4. al-kawari h, al-balbeesi ho, al-mazyad n, almutairib. bolton tooth-size discrepancies in a sample of saudi female orthodontic patients at college of dentistry, king saud university. j pak dent assoc 2012; 21(1): 31-4 5. othman sa, mookin h, asbollah ma, hashim na. bolton tooth-size discrepancies among university of malay's dental students. annal dent univ malaya 2008; 15(1): 40-7. 6. oktay h, ulukaya e. intermaxillary tooth size discrepancies among different malocclusion groups. eur j orthod 2010; 32: 307–12. 7. lara-carrillo e, gonzález-pérez jc, kubodera-ito t, montiel-bastida nm, esquivel-pereyra gi. dental arch morphology of mazahua and mestizo teenagers from central mexico. braz j oral sci 2009; 8(2): 92-6. 8. fernandes tmf, sathler r, natalcio gl, henriques jfc, pinzan a. comparison of mesiodistal tooth widths in caucasian, african and japanese individuals with brazilian ancestry and normal occlusion. dental press j orthod 2013; 18(3):130-5. 9. mirzakouchaki b, shahrbaf s, talebiyan r. determining tooth size ratio in an iranian-azari population. j contemp dent pract 2007; 8: 86–93. 10. nie q, lin j. comparison of intermaxillary tooth size discrepancies among different malocclusion groups. am j orthod dentofacial orthop 1999; 116: 539–44. 11. moorrees cfa, thomsen so, jensen e, yen pkj. mesiodistal crown diameters of the deciduous and permanent teeth in individuals. j dent res 1957; 36: 39–47. 12. lopatiene k, dumbravaite a. relationship between tooth size discrepancies and malocclusion. stomatologija, baltic dental and maxillofacial j 2009; 11: 119-24. 13. wedrychowska-szulc b, janiszewska-olswska j, ste˛pien´p. overall and anterior bolton ratio in class i, ii, and iii orthodontic patients. eur j orthod 2010; 32; 313-8. 14. ta ta, ling j yk, hägg u. tooth-size discrepancies among different occlusion groups of southern chinese children. am j orthod dentofacial orthop 2001; 120: 556–8. 15. uysal t, sari z. intermaxillary tooth size discrepancy and mesiodistal crown dimensions for a turkish population. am j orthod dentofacial orthop 2005; 128: 226–30. 16. endo t, shundo i, abe r. applicability of bolton’s tooth size ratios to a japanese orthodontic population. odontol 2007; 95: 57–60. 17. al sulaimani fh, afify ar. bolton analysis in different classes of malocclusion in saudi arabian sample. egyptian dent j 2006; 52: 1119-25. 18. o'mahony g, millett dt, barry mk, mcintyre gt, cronin ms. tooth size discrepancies in irish orthodontic patients among different malocclusion groups. angle orthod 2011; 81: 130-3. 19. basarana g, seleka m, hamamc o. intermaxillary bolton tooth size discrepancies among different malocclusion groups. angle orthod 2006; 76: 26–30. 20. al-khateeba sn, elham sj, abu alhaijab. tooth size discrepancies and arch parameters among different malocclusions in a jordanian sample. angle orthod 2006; 76: 459–65. 21. richardson er, malhotra sk. mesiodistal crown dimension of the permanent dentition of american negroes. am j orthod 1975; 68(2):157-64. 22. fernandes tmf, sathler r, natalcio gl, henriques jfc, pinzan a. comparison of mesiodistal tooth widths in caucasian, african and japanese individuals with brazilian ancestry and normal occlusion. dental press j orthod 2013; 18(3):130-5. 23. naseh r, padisar p, zarenemati p, moradi m, shojaeefard b. comparison of tooth size discrepancy in cl. ii malocclusion patients with normal occlusions. j dentistry shiraz university of med sci 2012; 13(4): 151-155. 24. lavelle clb. maxillary and mandibular tooth size in different racial groups and in different occlusal categories. am j orthod 1972; 61: 29–37. dropbox 09 haider 46-52 .pdf simplify your life j bagh college dentistry vol. 31(3), september 2019 effect of ageing 1 effect of ageing on selected salivary chemical compositions and dental caries experience among group of adults hiba k. al-tamimi, b.d.s. (1) (2) rawi, b.d.s., m.sc., ph d -nadia a. al abstract background: ageing is a continuous accumulative ordinary physiological phenomena occurs upon all organs and body structures including saliva by its constituents which can influence the caries process, for that this study was conducted to determine the impact of ageing on selected chemical composition of saliva and their effects on dental caries experience characteristics at different age groups among apparently healthy men. materials and method: a descriptive comparative study was conducted to compare between three study samples (young, middle and old age adults), thirty male in each study insert, aged (20 years, 40 years and 60 years) respectively. they were selected from private health center in baghdad iraq, from the mid of november 2017until the end of february 2018, where they subjected to complete body investigations to confirm their health status, followed by thorough general body history and oral examination. caries experience was recorded according to the criteria of who in1987. un-stimulated saliva was collected according to navazesh and kumer and analyzed chemically to determine the level of calcium ions and alkaline phosphatase. all data then statistically analyzed by using spss version 22. results: the current study, showed that the caries experience represented by dmfs increased with increasing age, by which the highest mean value of dmfs was established in the oldest age (60.37± 31.39) and the lowest mean value was noted among the youngest age (7.27±8.02). a significant differences existed between all study samples (p≤0.05). however, the missing surfaces represented the largest proportion of dmfs value when compared to ds and fs among all ages iin the current study, with significant differences (p≤0.05) was followed by the decay fraction that found to be increased with age but with no significant difference. salivary calcium ions showed decreasing with increasing age with statically significant differences among different study samples while salivary alkaline phosphatase was increased with increasing age with no significant differences. concerning the caries experience among the study samples, the salivary ca2+ ions inversely correlated while alkaline phosphates correlated positively with caries experience. conclusion: there is a significant age related changes on the selected chemical constituents of saliva that could affect the caries experience keywords: ageing, adults, un-stimulated saliva. (received: 23/8/2018; accepted: 24/9/2018). introduction aging is a time-dependent biological process involved changes in organ structure after maturity and the functions of organs can be regularly changed. ageing happens over all organs and overall individuals so no one can escape (1). age -related topics gain particular attention in aging societies, where adult people represent the growing target groups (2). some age-related changes affect the structures of oral cavity (both of hard and soft tissues) which experience continuous changes throughout the life (3). saliva has been well-defined as the mirror of the body through its ingredients such as enzymes, immunoglobulins and ions which have profound effects on oral homeostasis and any change in their equilibrium may lead to oral diseases including dental caries or periodontal problems (4). alkaline phosphatase includes a group of enzymes that catalyze the hydrolysis of phosphate esters in a basic surroundings. this enzyme shows a vital role in the bone metabolism and bone homeostasis by probably accumulating calcium ions and matrix vesicles during calcification process (5). along with alkaline phosphatase, calcium also acting a vital role in the hard tissue establishment and it upturns the confined concentration of inorganic phosphate and supports the mineralization, in this manner decreasing the meditation of extracellular pyrophosphate(an inhibitor of mineral formation) (6). there was a controversy regarding the levels of calcium and alkaline phosphatase with age after maturity of salivary glands. nasser et al. (7) who studied two different age groups (20-30) (60-80) to estimate the age related changes on un-stimulated salivary biomarkers found elderly groups revealed lower concentration of calcium when compared with young adults, while other studies found that salivary calcium was increased with age (8,9). 1) m. sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. 2) assist. professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. j bagh college dentistry vol. 31(3), september 2019 effect of ageing 2 punteeth et al (5) measured ca+2and alp in saliva and urine to estimate the rate of bone resorption and age related changes among adults aged (3060), they found that as the age increase the alp increased and ca decreased. thus releasing the fact that saliva can acts as a mirror of blood, so saliva can also be used with equivalent efficacy as that of the serum for the estimation of alp and calcium levels (6, 10). in spite of a knowledge explosion in the science of cariology, dental caries process still a misinterpreted phenomenon by the researchers. in order to practice the wide-ranging of the preventive approaches efficiently, it is imperious to look beyond those black and white spots that are obvious on the tooth surfaces. dental caries, as a common complex chronic infectious disease of the oral cavity, is a multi-factorial miracle elaborate with salivary constituents (11). different biochemical characteristics of saliva, like salivary alp and ca ions may affect the development of dental caries with wide range of controversy (12,13). very little information is available, concerning the effect of age on the salivary calcium and alkaline phosphatase and caries experience among apparently healthy adults, however, unfortunately no previous iraqi study is present at hand to investigate the impact of ageing on this salivary chemical consequents and dental caries experience, so this study was done to determine the effect of age on salivary calcium and alkaline phosphatase and caries experience among apparently healthy adults participants. subjects, materials and methods ninety healthy males, were incorporated in this comparative study in three study samples; young, middle and old adults aged (20, 40 and 60 years) respectively. according to the world health organization, every person's age was estimated regarding his last birthday (14). each convenient sample entailed of thirty subjects, they were attending the international medical center (private medical center) at baghdad-iraq for general health check-up and treatment if there is any need. an approved permission was achieved from the international medical center before data collection in order to examine the selected persons with no obligation. the purpose of study was effusively clarified to the participants in order to achieve their full responsiveness and cooperation. in addition, a special consent was arranged and specified to the selected participants to get the permission for their participation in the study. the present study was approved by the committee of pedodontics and preventive department at baghdad college of dentistry the inclusion criteria .didn’t have any systemic disease and apparently healthy according to the findings of full body investigations they did. . nonsmokers . did not receive any medicaments in the last three months before examination. · did not have any oral lesion and they didn’t wear any removable or fixed appliance. · whom agreed to contribute in this study, and were existing in the time of collection. un-stimulated saliva was collected between 9, and 11 am to reduce any circadian rhythm. a total of 5 ml of unstimulated saliva were collected in centrifuge tubes one hours after subjects were instructed to do not eat, drink or brush their teeth, according to the navazesh & kumer method (15). after the collection of saliva, samples were centrifuged at 3000 rpm for 5 minutes, the clear supernatants were separated and stored frozen at _20 ºc in plastic polyethylene tubes until the time of biochemical analysis in the center of toxicology/ specialized surgeries hospital/ baghdad. in the present study, dental caries experience was diagnosed and recorded according to (dmfs) index following the criteria of who as it is more sensitive index for caries intensity since it was measured in the term of surfaces rather than teeth (16). dental caries experience was carried out by using dental explorer and plane mouth mirror. assessment of caries experience was carried out by calculating the dmfs for each participant. calcium level (mg/dl) determined using air – acetylene atomic absorption spectrophotometer (buck scientific, 210vgp, usa). instrumental settings were performed according to instrumental manufacturer specifications (17). salivary alkaline phosphatase (ui/l) was estimated by using alkaline phosphatase kit, which functions on the basis of modified kind and king’s method, using alkaline phosphatase-kit by biolabo sas, france. colorimetric determination of alkaline phosphatase activity, then all data were collected statistically analyzed by using computer software program as statistical package for social sciences (spss version 22). statistical analysis can be classified into two categories: j bagh college dentistry vol. 31(3), september 2019 effect of ageing 3 1-descriptive analysis: frequency, percentage for nominal variables while mean, and standard deviation for numeric variables (quantitative). 2inferential analysis: alevene test: test the equality of variances between groups. when the p value of levean test is significant, dunnet t3 was used while if the p value of levean te is not significant, the least significant differences (lsd) was used. bone way analysis of variance (anova): test the hypothesis for a quantitative dependent variable by a single factor (independent) variable. cpearson correlation is a bivariate analysis that used to measure the strengths of association between two quantitative variables. level of significance: not significant at p>0.05, significant at p≤0.05. results results of the present study revealed that, the highest value of caries free was found among the youngest age, who recorded 20% caries free and decreased with age to be 0% in the oldest adult, these results were demonstrated in table 1. dental caries experience presented by dmfs index and its fractions was illustrated in the table 3 .it was clear that caries experience (dmfs) was increased with age, in which it was found to be higher mean among old adults (60.37± 31.39) when compared to the mean of dmfs among middle age (22.07± 20.33) and young adults (7.27±8.02). regarding dmfs fractions, the decayed surface (ds) found to be increased with age where the lowest mean value was found among the (20 years) followed by 40 years and highest mean value was recorded among the old adults as listed in table 3. however, no significant difference was found between the three ages. according to dunnetst3, a significant difference was existed between dmfs among all ages of the current study (p≤0.05) as in table 2. concerning the missing fraction (ms), it was found to be the largest proportion of dmfs value when compared to ds and fs among all age groups. moreover, the old age group had the highest ms (52, 60 ± 31.36) when compared with the other groups that demonstrated in table 3. dunnetst3 with ms revealed a statically significant difference (p≤0.05) among all ages of the present study table 4. the smallest fraction of dmfs index in the current study was found to be the fs fraction, when compared with ds and ms fractions, among different study samples of the current study. the results revealed a highest mean value of filling surface among middle age (4.27± 7.84) compared with young and old adults (0.83± 1.72) (2.47± 7.07) respectively as listed in table 4. table 1: distribution of caries free among subjects by ages age years no. of subjects no. of caries free % 20 30 6 20 40 30 5 16.7 60 30 0 0 table 2: dunnett’s t3 between dmfs fraction among different ages 20 years 40 years 60 years hs hs hs j bagh college dentistry vol. 31(3), september 2019 effect of ageing 4 table 3: caries experience by dmfs index and its fractions among different ages variables ds age (years) mean ± sd anova f p-value ds 20 3.50 4.10 0.800 0.452 40 3.93 7.21 60 5.30 5.52 ms 20 2.93 6.09 48.884 0.000* 40 13.97 15.23 60 52.60 31.36 fs 20 0.83 1.72 2.317 0.105 40 4.27 7.84 60 2.47 7.07 dmfs 20 7.27 8.02 46.208 0.000* 40 22.07 20.33 60 60.37 31.39 * p≤0.05 table 4: dunnett’s t3 between ms fraction among different ages 20 years 40 years 60 years hs hs hs concerning the means and standard deviation of salivary ca+2 measured in mg/dl, the results showed the mean value of salivary calcium decreased gradually with increasing age with significant difference among the different study samples. while for alkaline phosphatase (alp), the results of the current study showed that the mean value was higher in both middle and old adults when compared with young adults, however statistically there was no significant differences, as illustrated in the table 5. regarding the correlations coefficient of salivary ca+2 and caries experience that showed in the table 4, among young adults, the table revealed that, a weak positive correlations coefficient between salivary ca+2 with dmfs and its fractions, and statistically no significant correlations were recorded. in another hand, among middle age group, a negative correlations were found between salivary ca+2 with dmfs, fs fractions, a significant correlation was found between salivary ca+2 with fs fractions among the same age. while among old adults, a negative correlations was existed between salivary ca+2 with ds, ms and j bagh college dentistry vol. 31(3), september 2019 effect of ageing 5 dmfs, but statically failed to reach the significant differences. regarding the correlation coefficients between the salivary alp and caries experience among different study samples that illustrated in the table 6, the current investigation found a positive non-significant correlation between salivary alp with ds, ms fraction and dmfs among young age, while a negative non-significant correlation was found between salivary alp and fs fraction. among 40 years, the same table illustrate a positive significant correlation was found between alp with ds fraction. whilst among 60 years, the current findings revealed, a negative significant correlation between alkaline phosphatase with ds fraction. in addition a strong positive significant correlation between salivary alp and fs fraction while a negative non-significant correlation was found between alp with dmfs fraction. table 5: selected salivary chemical component among the three ages age (years) variables mean ±sd anova f-value p-value f p-value 20 ca+2(mg/dl) 4.34 0.43 56.86* 0.000 40 3.47 0.59 60 3.25 0.58 20 alp (ui/l) 0.51 0.31 1.000 0.372 40 0.56 0.26 60 0.55 0.28 * p≤0.05 table 6: correlation coefficients between salivary calcium with caries components among salivary variable age (years) ds ms fs dmfs r p r p r p r p ca+2 20 0.310 0.096 0.138 0.468 0.018 0.926 0.267 0.154 40 0.094 0.620 0.090 0.636 -0.381* 0.038 -0.042 0.826 60 -0.336 0.070 -0.275 0.142 0.082 0.665 -0.315 0.090 * p≤0.05 table 7: correlation coefficients between salivary alkaline phosphatase with caries components among ages salivary variable age (year) ds ms fs dmfs r p r p r p r p alp 20 0.268 0.152 0.107 0.573 -0.138 0.468 0.189 0.137 40 0.414* 0.023 0.028 0.882 0.013 0.948 0.168 0.375 60 -0.398* 0.029 -0.316 0.089 0.551* 0.002 -0.261 0.163 * p≤0.05 j bagh college dentistry vol. 31(3), september 2019 effect of ageing 6 discussion: the current study revealed a decreasing in the percentage of caries free subjects with age till it reached 0% among the old adults, the observed finding was close to that found by other studies (18,20). the current study recorded a significant differences in caries experience represented by dmfs; this result came in accordance with the finding of farsi (20). however this was in contrast with the other study (21). the variations between the findings of the studies may be related to many factors such as the sample size and the method by which dental caries was examined, in addition to the environmental and the genetic factor (22). in addition the ms fraction represented the largest fraction of dmfs among all the study samples, especially among the oldest adult who recorded the highest ms which could be due to the fact that dental caries is an irreversible process and accumulative in nature with ageing on one hand and to the insufficiency of the planed preventive programs especially among the old adults who had poor dental knowledge as well as oral health, didn’t receive an optimal dental care and had complicated past dental history (23), in addition to that, they were prefered tooth extraction over restorations because there were several barriers to self-care and professional care. (24). these findings came in agreement with the others (25-27), however other studies recorded the same result but with no significant differences (17, 28). concerning ds fraction, which was increased with age and this result came accordance with other study (19) . the current study came discordance with other study that recorded also an increase of ds with age, as the finding of the recent study, but the dissimilarity was with ds fraction that was not-represented the largest fraction of dmfs of current study with no significant difference (29). the variations in the caries experience between studies may be related to the variations in the methodology of each study, the absence of bitewing radiographs to diagnose the interproximal caries in the recent study could leading to the underestimation of ds component, in addition to that, the participants of present study preferring tooth extraction. while the other causes of increasing the ds mean value among old age groups may be related to the most cariogenic risk with ageing which could be the dysfunction of the salivary glands, less effective oral hygiene habits, decreased motor function and variation in dietary habit, hygiene measures, and consumption the diet rich in cariogenic food (30). the highest mean value of fs fraction, which represented the smallest fraction of dmfs index in the current study, was found within the middle age group. this finding came with agreement with the result of other study (31) which may be related to the utilization of dental health services among the middle age group and that reflect their knowledge, attitude and behavior about the importance of preserving teeth even after they affected by decay (20). however, this finding was in disagreement with that of other studies (17, 19). the differences in these findings between the studies may be related to the variation in the dental health services provided, subjects health knowledge and preferences, geographical location and racial factors. in addition to the cultural, social and economic differences found between the studies (31). concerning the mean value and standard deviation of salivary ca+2, the present investigation recorded decrease in the mean value of salivary ca+2 with age which could be attributed to the lower intestinal absorption rate, lesser vitamin d absorption and metabolism with age, decreased muscular proteins and flow of blood to bone (29). this result came with agreement with other studies (5,7) however the current study was in discordance with the findings of other studies which found the salivary calcium level was increased with age this may be related to different age groups, genders included in both studies (8,9). regarding the correlations coefficient of salivary ca+2 with caries experience, the current study revealed inverse but not significant correlation of salivary calcium with the dental caries indicated by ds, ms and dmfs with ageing, this showed the importance of ca+2 in increasing the resistance of the outer enamel surface to acid dissolution and enhancing remineralization of the initial carious lesion (32). the present result was in consistent with the finding of hasan and diab in 2010 (33), but inconsistent with the findings of others (34, 35) who found that the salivary ca+2 had no relation to the caries experience. in addition, the present study recording inverse relation between age and levels of alp and ca+2 indicating that as age increases, alp increased and ca+2 levels decreased. the explanation for these results which could be related to the known fact that, the levels of calcium depletes with age, resulting in the reduction of bone strength. thus the increase in the level of salivary alp with ageing can represented as j bagh college dentistry vol. 31(3), september 2019 effect of ageing 7 compensatory mechanism to overcome the depletion that occurs to calcium ions with ageing (36). the result of current study was in agreement with the study of other (5). concerning the correlations coefficient of salivary alp and caries experience, the result was recorded a negative significant correlation with (ds) fraction among old adults who recorded highly caries experience, this result could be due to the variations in alp levels caused changes in phosphate levels which leading to initiation and progression of caries (37). this result came with agreement of the results of other studies (38, 39), while disagreement with the results of others (6, 40), who found a positive correlation between salivary alkaline phosphatase with dental caries. the variations between the results of current study and other previous study may be related to different age groups, method of measurement. conclusion the thoughtful elaboration of the age related changes in the saliva and its constituents is an imperative manner, as well increasing in the mindfulness and consideration to enhance the knowledge of the community about the importance to identify oral health damage 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of salivary al¬kaline phosphatase in periodontitis patients and healthy subjects. j res dent sci 2011; 8(1): 9-14. 40. vijayaprasad ke, ravichandra ks, vasa aa, suzan s. relation of salivary calcium, phosphorus and alkaline phosphatase with the incidence of dental caries in children. j indian soc pedod prev dent 2010; 28(3): 156-61. j bagh college dentistry vol. 31(3), september 2019 effect of ageing 9 الخالصة اللعاب ومكوناته والتي يمكن ان متضمنة الظواهرالفزيولوجية الطبيعية التراكمية المستمرة التي تطرأ على جميع اعضاء وهياكل الجسم منالشيخوخة تعد : الخلفية ملية التسوس في تاثيرها على خصائص عدراسة اجريت هذه الدراسة لتحديد تاثير تقدم العمرعلى مكونات كيميائية مختارة من اللعاب و تؤثر على عملية التسوس لذلك االصحاء. بالغينمجموعات عمرية مختلفة بين ال 20) دراسة عينة كل في ذكرا ثالثون ،( السن وكبار العمر متوسطي ، الشباب) دراسية عينات ثالث بين للمقارنة وصفية مقارنة دراسة أجريت spss: المواد والطرق خضعوا حيث ، 2018 فبراير نهاية حتى 2017نوفمبر منتصف من ، العراق -. بغداد في خاص صحي مركز من اختيارهم تم ، التوالي على( سنة 60 ، سنة 40 ، سنة العالمية الصحة منظمة لمعايير وفقا التسوس تجربة تسجيل تم. الفموي والفحص العام تاله اخذ التاريخ الصحي ، الصحي وضعهم لتأكيد شاملة لفحوصات مختبرية تمم تحليل ، القلوية والفوسفاتيز الكالسيوم أيونات مستوى لتحديد كيميائيا تحليله وتم navazesh and kumer (2008 ) وفقا ل المحفّز غير اللعاب جمع تم ( 1987) . 22اصدار اإلصدار spss باستخدام إحصائيا البيانات جميع الكبار في dmfs قيمة متوسط أعلى على العثور تم حيث ، العمر تقدم مع تزداد dmfs بواسطة تمثيلها التي تم التسوس تجربة أن الحالية الدراسة اظهرت النتائج : ومع (. p≤0.05) الدراسة عينات جميع بين إحصائية داللة ذات فروق وجدت (. 8.02( ± 7.27) سنا األصغر بين للقيمةوجد متوسط وأدنى( 31.39± 60.37) البالغين وتال ( p≤0.05) داللة ذات فروق وجود مع ، الحالية الدراسة اعمار جميع بين fs و ds مع بالمقارنة dmfs قيمة من نسبة أكبر (ms)المفقودة األسطح مثلت ، ذلك فروق وجود مع العمر زيادة مع تناقص ا اللعابية الكالسيوم أيونات وأظهرت. داللة احصائية بدون ولكن السن في التقدم مع يزداد أنه وجد الذي (ds)التسوس جزء ذلك بتجربة يتعلق فيما. إحصائية داللة ذات فروق وجود عدم مع العمر بزيادة زاد اللعابي القلوي الفوسفاتاز أن حين في المختلفة الدراسة عينات بين إحصائية داللة ذات تسوس. تجربة مع إيجابيا القلوية الفوسفات ارتبطت حين في عكسيا الكالسيوم اليونات ارتبطت ، الدراسة عينات بين التسوس . على عملية التسوس بدورها للعاب والتي اثرت من اختالفات واضحة في المكونات الكيميائية المختارة هناك االستنتاج: . الشيخوخة ، تسوس االسنان ولعاب غير محفز كلمات مفتاحية: j bagh college dentistry vol. 29(4), december 2017 the influence among restorative dentistry 20 the influence of different fabrication and impression techniques on the marginal adaptation of lithium disilicate crowns (a comparative in vitro study) shatha saadallah, b.d.s (1) abdul kareem j. al-azzawi, b.d.s., m.sc. (2) abstract background: the marginal adaptation has a key role in the success and longevity of the fixed dental restoration, which is affected by the impression and the fabrication techniques .the objective of this in vitro study was to evaluate and compare the marginal fitness of lithium disilicate crowns using two different digital impression techniques (direct and indirect techniques) and two different fabrication techniques (cad/cam and press techniques). materials and methods: thirty two sound upper first premolar teeth of comparable size extracted for orthodontic reason were selected in this study .standardized preparation of all teeth samples were carried out with modified dental surveyor to receive all ceramic crown restoration with 1 mm deep chamfer finishing line, 4 mm axial length and 6 degree convergence angle. half of the teeth were duplicated and poured in type iv dental stone to have sixteen dies and then these dies and the remaining teeth divided in to two groups according to the type of digital impression techniques (n=16) as follow: group a: indirect digital impression technique scanned by ineos x5 camera; group b: direct digital impression technique scanned by cerec ac omnicam camera. each group was subdivided according to the technique of fabrication into two subgroups (n=8): press technique using ips e-max press (a1, b1); cad/cam technique using ips e-max cad (a2, b2).marginal gaps were evaluated on the prepared teeth at four defined points on each aspect using digital microscope at a magnification of (280x). one way anova and lsd tests were used to identify and localize the source of difference among the groups. results: the results showed that indirect digital impression with ips e-max cad/cam group a2 revealed the poorest marginal integrity with (55.93 μm ± 3.300). group b2 and group a1 were next in line with(44.49 μm ± 6.840 and 37.74 μm± 5.433) respectively, while in the first group of restorations, the result of 29.9 μm ± 5.534 obtained with direct digital impression with pressable ceramic was clearly better. conclusions: all the tested digital impression techniques showed clinically acceptable accuracy and intraoral scanning with pressable ceramic significantly enhanced the marginal fit key words: marginal fitness, cad/cam system, digital impression, press technique. (j bagh coll dentistry 2017; 29(4):20-26) introduction marginal fit is an important predictor of the clinical success and longevity of dental prosthesis (1). marginal discrepancy can be defined as the vertical distance from the finish line of the preparation to the cervical margin of the restoration (2). poor marginal adaptation increases plaque accumulation, recurrent caries and causing periodontal diseases (3). increasing patients demand for esthetic dental restoration have made metal-free, all-ceramic system more widely distributed due to their enamel-like color, light transmission and improved reproduction of the translucency of natural teeth (4,5). several ceramic systems which may differ in composition or fabrication technique are available; lithium disilicate is one of them. lithium disilicate is a glassy ceramic that has 70% crystalline phase and claim to have optimum esthetics, natural light refraction and high flexural strength in the range of 360-400 mpa (6). (1) master student, department of conservative, college of dentistry, university of baghdad. (2) professor, department of conservative, college of dentistry, university of baghdad. it can be made using either lost-wax hot pressing techniques (ips e.max press) or (cad/cam) milling procedures (ips e.max cad) (7). impressions made with elastomers materials, also known as conventional impressions, represent a commonly used procedure in general dental practice. low reproduction of the preparation margins, tearing of the impression material and an undistinguishable margin on the stone dies are frequently encountered problems (8). there are several reasons for these problems, including the knowledge and skill level of the practitioner (9). however, there are potential sources of error are not practitioner-related include the disinfection procedures, total or partial separation of the impression material from the tray and transportation to the dental laboratory under different climatic conditions (10,11). to eliminate the need for the traditional impressiontaking, model-pouring and laboratory-shipping steps of fabricating crowns, cad/cam systems introduced in the dental field (12). digital computer aided design and computer aided manufacturing (cad/cam) is a 3-dimensional j bagh college dentistry vol. 29(4), december 2017 the influence among restorative dentistry 21 scanning technology being utilized in dentistry to increase productivity, patient satisfaction and optimize the quality of the restoration as well as the efficiency of the workflow (13). materials and methods teeth preparation: thirty two sound recently extracted maxillary 1st premolar were collected for this study, the root of each tooth was embedded in an individual block of acrylic to about (2mm) below the cej by the aid of surveyor. each specimen was prepared to receive all ceramic crown using high speed turbine hand piece with water coolant that was adapted to the vertical arm of the modified dental surveyor in such a way that the long axis of the clinical crown kept parallel to that of the bur all the way during tooth preparation procedure to ensure the same convergence angle for all specimens (fig.1). each specimen was prepared with the following preparation features; a planar (anatomical) occlusal reduction, 1.0 mm depth deep chamfer finishing line, 6 degree convergence angle and 4 mm height (fig.2). (a) (b) figure 1: tooth preparation with modified dental surveyor. figure 2: finished prepared tooth. impression procedures impression was taken for sixteen teeth by one step impression technique using addition silicone heavy and light body viscosity. the heavy impression material (express™ xt penta™ h) was automatically mixed by pentamix lite automatic mixing machine (3m espe, germany), while the light body material (express™ xt) was mixed and dispensed using a garant dispenser (3m espe, germany). the heavy body was injected into the special tray and the light body material was carefully injected on the prepared tooth until the tooth was completely covered then the special tray loaded with heavy body was seated on the specimen by a dental surveyor under a 500 g load until the three guided pines completely engaged the holes in the acrylic base of the specimen (fig. 3).this procedure was continued sixteen times to get sixteen impression. impressions were then poured by type iv dental die stone; all the procedure was done according to the manufacturer's instructions. j bagh college dentistry vol. 29(4), december 2017 the influence among restorative dentistry 22 figure 3: impression taking with dental surveyor. samples grouping the prepared teeth specimens and the working dies are divided into two groups according to the technique of digital impression: group a: indirect digital impression technique. group b: direct digital impression technique. each group was then subdivided into two subgroups according to the fabrication techniques as follow: a1: indirect digital impression was taken for eight dies using cerec ineos x5 scanner for the fabrication of eight ips e-max press crowns. a2: indirect digital impression was taken for eight dies using cerec ineos x5 scanner for the fabrication of eight ips e-max cad/cam crowns. b1: direct digital impression was taken for eight prepared teeth using intraoral cerec ac omnicam camera for the fabrication of eight ips e-max press crowns. b2: direct digital impression was taken for eight prepared teeth using intraoral cerec ac omnicam camera for the fabrication of eight ips e-max cad/cam crowns. crowns fabrication inlab mc x5 (sirona dental systems, bensheim, germany) was used to fabricate the full ceramic crowns and the wax patterns using cerec in-lab (version 15.2) software. cad/cam crowns fabrication (a2, b2): ips emax cad (lt a2, ivoclar vivadent, schaan, liechtenstein) block was used to construct ceramic crowns for these groups. the crowns were designed using the biogeneric software according to the recommended parameters (80 μm cement spacer and 100 μm marginal thickness) then crystallized in a short 25 minutes firing cycle in a ceramic firing furnace (programat p310, ivoclar vivadent/technical, schaan, liechtenstein) at 840ºc according to the manufacturer’s instructions. pressing fabrication technique (a1, b1): the same procedure used for the fabrication of ips emax cad crowns was followed here in order to fabricate a digital wax patterns using blue cad/cam wax blank (bilkim, izmir, turkey). the sixteen wax patterns were sprued and invested into the investment ring. the investment ring was then preheated in a burn out furnace at (850ºc) for 45 min. after that, the ring was removed from the preheated furnace and a cold ips e.max press (lt a2, ivoclar vivadent, schaan, liechtenstein) ingots were placed inside the investment ring followed by placement of cold ips alox plunger and then transferred into the center of the preheated pressing furnace (programat ep3000; ivoclar vivadent schaan, liechtenstein) at 920ºc (fig. 4). (a) (b) (c) (d) j bagh college dentistry vol. 29(4), december 2017 the influence among restorative dentistry 23 (e) figure 4: steps of press crown fabrication. measurement of the marginal gap the marginal fit of the crown was calculated by measuring the vertical gap between the margin of the tooth and that of the ceramic crown. a specially designed holding device was used to apply a static load of (50 n) on the tested crowns to ensure the accuracy of their seating and to hold them in place during the examination (14). with a dino-lite digital microscope at a magnification of 280x the measurements were performed on four points on each tooth surface (two on both sides of the indentation): first point was determined on the edge of the indentation whereas the second one was (1mm) from the first point, a total of 16 marginal adaptation evaluation sites for each tooth (15) (fig. 5). the digital images were captured by (dino capture software) and then analyzed with image analysis software (image j, 1.50i, u.s. national institutes of health, bethesda, ma, usa) which was used to measure the vertical marginal gap by drawing a line between the margin of the tooth and that of the crown. calibration for magnification was made by taking an image of a millimeter ruler at the same magnification (280 x) and input into (image j) and converted the readings from pixels to (μm) (fig.6). figure 5: points of measurement. figure 6: image of one millimeter at 280x magnification. statistical analyses data were collected and analyzed using spss (statistical package of social science) software version 18. the following statistics were used: adescriptive statistic: including mean, standard deviation, statistical tables and graphical presentation by bar charts. binferential statistics i. one way analysis of variance test (anova) was used to see if there were any significant differences among the means of subgroups. ii. lsd (least significant difference) test was carried out to examine the source of differences among the four subgroups. results total of (512) measurements of vertical marginal gap from four subgroups were recorded, with 16 measurements for each crown. table (1) showed that the highest mean of vertical marginal gap was recorded in group a2 (55.93 μm ± 3.300).while the lowest mean marginal gap was recorded in group b1 (29.91 μm ±5.534) and this clearly explained in (fig.7) while table (2) and table (3) showed that there is a highly significant difference in vertical marginal gap among the four subgroups. table 1: descriptive statistics of vertical marginal gap for all groups in (μm) . digital technique groups descriptive statistics n min min. max max. mean mean± std. indirect digital technique a a1 8 22.029 47.788 37.74±5.433 a2 8 43.072 62.169 55.93±3.300 direct digital technique b b1 8 17.468 42.276 29.91±5.534 b2 8 27.431 59.661 44.49±6.840 j bagh college dentistry vol. 29(4), december 2017 the influence among restorative dentistry 24 table 2: anova test among the groups. sum of squares df mean square f sig. between groups 27963.264 3 9321.088 160.833 0.000 (hs) within groups 1622.747 28 57.955 total 29586.012 31 hs: p≤0.01 table 3: lsd test for comparison of significance between subgroups. groups mean differences pvalue a1 a2 -18.19 0.000(hs) b1 7.83 0.000(hs) b2 a2 -11.44 0.000(hs) b1 14.58 0.000(hs) hs: p<0.01 figure 7: bar-chart showing the mean values of the marginal gap in (μm) for all subgroups. discussion results obtained from the current study showed that the marginal gap of the four groups was within the clinically acceptable range because the mean marginal gap with the range of 120 μm have been proposed as being clinically acceptable with regard to the longevity of restorations(16). effect of digital impression technique: the results of this study revealed that indirect digital technique groups had significantly higher marginal gap than the direct digital groups. the higher inaccuracy of the indirect way is always present from the first steps of the process until completion of the definitive restoration due to the fact that conventional impression technique requires numerous steps such as impression materials selection, tray selection, use of adhesives, disinfection, transportation, pouring and since every step in a workflow contributes to the risk of overall failure, the elimination of the conventional impression and its inherent risks, results in higher accuracy (17,18). on the other hand, direct digital impressions (omnicam camera) do not require disinfection, land transportation or fabrication of a gypsum cast. thus, the potential for dimensional inaccuracies could be eliminated, or at least dramatically reduced (17). the results of this study agree with jonthan et al. (2014) (19) and khdaier and ibraheem (2016) (20) who founded that crowns fabricated with direct digital impressions showed more accurate marginal adaptation. however, this finding is in contract with salem et al. (2016) (21) who concluded that the conventional impressions are significantly more accurate. such disagreement could be due to the difference in the methodology used. effect of the fabrication technique: according to the results of this study, crowns fabricated with cad/cam technique showed higher marginal gap than crowns fabricated with press technique. this may be due to the shrinkage of the material during crystallization process causing distortion of the margins. 0 10 20 30 40 50 60 a1 a2 b1 b2 37.74 55.93 29.91 44.49 j bagh college dentistry vol. 29(4), december 2017 the influence among restorative dentistry 25 at the time of milling, ips e-max cad block is partially crystallized (lithium metasilicate) and the size of particles generally ranges between 0.2 μm and 1.0 μm with a flexural strength of 130 mpa. after crystallization at 840°c for 25 minutes in a furnace, the size of the particles increases under control to 5 μm. through such modification processes, the flexural strength of the restoration increases to 360 mpa, an increase of 170% (22, 23). the crystal spacing becomes denser and the proportion of fine lithium disilicate crystals within the glassy matrix increases from 40% to 70% after complete crystallization. such changes was not fully controllable and causes 0.2% linear shrinkage which affect the overall fit of the dental prosthesis, increasing marginal gaps (24,25,26). in pressed ceramics, sintering shrinkage during firing may be avoided because it is fabricated by a combination of the lost-wax and heat pressed techniques. in this technique, the complete contour wax pattern is invested and a ceramic ingot is pressed into the resultant investment mold to the full extent of the wax pattern (27). the result of this study was coinciding with mously et al. (2014) (28) and neves et al. (2014) (29) who found that lithium disilicate restoration fabricated with the press technique had significantly smaller marginal gap than those fabricated with cad technique. however, the finding of this study is disagree with study done by jonthan et al. 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6(2): 163-168. 28. mously ha, finkelman m, zandparsa r, hirayama h. marginal and internal adaptation of ceramic crown restorations fabricated with cad/cam technology and the heat-press technique. j prosthet dent 2014; 112(2): 249-256. 29. neves fd, prado cj, prudente ms, carneiro ta, zancopé k, davi lr, mendonça g, cooper lf, soares cj. micro-computed tomography evaluation of marginal fit of lithium disilicate crowns fabricated by using chairside cad/cam systems or the heat-pressing technique. j prosthet dent 2014; 112: 1134-1140. الخالصة الماااالط الطواااااب نالاااايت لالتت تاااال اتاااات ى لت تااااا التطاااااله اليالهاااا لااااف نج ج تراااا ااااا الااااا لى ت ااااا ا اااا ا ال التاااا اااا التص تع نالط عا . اللجا اااا الميت ىااااا ااااو لت تااااتق نل اجااااا التطاااااله اليالهاااا ل تتلااااا المصاااا ع لاااا لااااا الياااا ال ااااا يه الياااال لاااا اااا تاااا التصااا تع الميت ااا لا اااتيلاث ا ااات لااا ل تاااا الط عاااا لل تااا الط عااا الىممتااا الم اياااى ن تاااى الم اياااى نا ااات لااا ل للرا ل الحا وب/الم حو لوا ط الحا وب نل ت الضغط لوا ط المليى الىمم . لااا ا ااا ا الضاااواال ا نلااا الع تاااا قا ا الااااث المت اجلااا نالم و ااا لغاااى العااا الت اااوام . لحضاااتى 23لاااق ااتتااااج ل ل اااق ااااااا ل واااا ااااو 1ا ا ااا ا المعااالص ل حصاااوص ااا لواااال نل اااال للماااع ت اااا ا ااا ا لاااق لوا اااط ياااا لرااا ل اااق اناااا ل ااااجب اااق اااااي عااا ل صااا امااااق ا ااا ا ل حصاااوص ااا امااااق 6ل اااق اااوص لحاااوجت ن 4الهااال العمتاااه ت .16 رت ق ل رتق ال ماق الل رت نا ا المت ت ال للمو تت لكب للمو ل .(ineos x5 ت الط عا الىممت تى الم ايى لا تيلاث التىا للمو أ:لق لصواى ا لت . omnicam)واى ا لت ت الط عا الىممت الم ايى لا تيلاث التىاللصللو ب : لق ت 8 ق لق ل رتق ب للمو ال للمو تت لكب ل يا ل .ips e-mx press: لق لىلتق ا ا لا تيلاث لا 1نللمو ب 1للمو أ .ips e-max cad: لق لىلتق ا ا لا تيلاث لا 3نللو ب 3للمو أ ا ارا ل ن اط اب اطن لا ا اطن الرا ا لؤياى لاا ألجلاع ماو ت لراتوط لا الحااا ا اضا ا متاا لاق ل ال . image jنلىاالج لعالج الصوج ل 382xنلتك تى المليى لوا ط ال تا ا ىاء لق .نال يوت اليلت الواه نا ااا لعااالص ل لاااو 1لاااااكىن ل ملمو ااا ب 39.91اظياااى اتاااا ج ااايه اللجا ااا ا اماااب لعااالص ل لاااو اليالهااات اااا ل . 3لااكىن ل ملمو أ 99.92ل اليالهت ا لتع اظيى اات اا ااصا تا التا لت الملاlsd ت ا للاه ناص ااا anova اتا ج اص -ips eلاا ااا اراات تج ا ل تاا الط عااا الىممتاا الم ايااى اظيااى اتااا ج ااضااب لاا ل تاا الط عااا تااى الم ايااى ناظيااىل max pressااضاااب اراااق لطااااله الهااا . لااا اج الط عاااا الىممتااا الم اياااى لا اااتيلاث اااالتىا ل omnicam لاااع ل ips e-max . ا تج اليوالش ا ى م j bagh college dentistry vol. 32(2), june 2020 effect of diabetes 12 effect of diabetes mellitus on periodontal health status, salivary flow rate and salivary ph in patients with chronic periodontitis lekaa m. ibraheem (1), ban z. ahmmad (2), ayat m. dhafer (3), jannat m. dhafer (3) article doi: https://doi.org/10.26477/jbcd.v32i2.2888 abstract background: diabetes and periodontitis are considered as chronic diseases with a bidirectional relationship between them. this study aimed to determine and compare the severity of periodontal health status and salivary parameters in diabetic and non-diabetic patients with chronic periodontitis. materials and methods: seventy participants were enrolled in this study. the subjects were divided into three groups: group i: 25 patients had type 2 diabetes mellitus with chronic periodontitis, group 2: 25 patients had chronic periodontitis and with no history of any systemic diseases, group 3: 20 subjects had healthy periodontium and were systemically healthy. unstimulated whole saliva was collected for measurement of salivary flow rate and ph. all periodontal parameters (plaque index, gingival index, probing pocket depth and clinical attachment level) were recorded for each patient. results: the results showed that all clinical periodontal parameters were highest in group 1 in comparison with groups 2 and 3. comparisons between pairs of groups revealed significant differences between groups 1 and 2 for plaque index, gingival index, probing pocket depth and clinical attachment level, and highly significant differences for plaque index, gingival index between groups 2 and 3, and between groups 1 and 3. the salivary flow rate and ph were lower in group 1 compared to groups 2 and 3. inter-group comparisons of salivary parameters also revealed a significant difference between groups 1 and 2, with a non-significant difference between groups 2 and 3. conclusion: type 2 diabetic patients have significantly lower salivary flow rate, ph and present with advanced periodontal destruction compared to healthy patients. key word: saliva; periodontitis; diabetes mellitus. (received: 29/12/2019; accepted:1/2/2020) indroduction periodontal diseases are inflammatory diseases caused by bacterial infection of the supporting tissues around the teeth.(1)oral microbiota (dental plaque) causes initiation and proliferation of periodontal disease, because of the interaction between these microbiota and immune defenses leading to inflammation and disease occurrences. (2) diabetes mellitus includes a series of metabolic disorders distinguished by defects in insulin action, secretion or both leading to a hyperglycemic state. (3) there are many oral manifestations seen in diabetic patients such as xerostomia, gingivitis, periodontitis, multiple periodontal abscess, dental caries, with burning mouth syndrome.(4-6) diabetes is counted as a risk factor for enhancing periodontal disease. (7) chronic periodontitis (cp) was considered as a complication of diabetes infections of tongue, and oral mucosa-like chronic atrophic candidiasis. (8) __________________________________ (1) b.d.s., m.sc. prof. periodontology, dentistry department, al-esraa university. (2) b.d.s., m.sc. assistant lecturer in periodontology, dentistry department, al-esraa university. (3) b.d.s., college of dentistry, university of baghdad corresponding author, lekaa_m61@yahoo.com a bidirectional cyclical relationship has been noticed between diabetes mellitus and periodontitis. (8) furthermore, in several studies the incidence, prevalence and severity of chronic periodontitis (cp) were found to be higher in the presence of diabetes. (9) diabetes mellitus manifests in altering the salivary composition and its functions. change in oral environment initiates pathogenic bacteria, damaging hard and soft tissues of the oral cavity leading to an increased cariogenic activity and periodontal lesions. (10) the salivary glands are affected directly or indirectly by type 2 diabetes mellitus (t2dm). (11) diabetes-associated autonomic neuropathies, microvascular changes, hormonal imbalances or a combination of these are responsible for salivary hypo function and dehydration in diabetics. (12) saliva-based diagnostics are not limited to oral diseases but have been extended to the entire physiologic system, as most compounds found in the blood are also present in the saliva. accordingly, saliva can reflect the physiologic state of the body including emotional, endocrinal, nutritional, and metabolic variations, and acts as a source for monitoring oral and systemic health.(13) this study aimed to determine and compare the severity of periodontal health status and salivary parameters in diabetic and non-diabetics patients with chronic periodontitis. https://doi.org/10.26477/jbcd.v32i2.2888 http://www.jispcd.org/article.asp?issn=2231-0762;year=2017;volume=7;issue=1;spage=28;epage=33;aulast=puttaswamy;type=3#ref4 j bagh college dentistry vol. 32(2), june 2020 effect of diabetes 13 materials and methods total samples were composed of 70 males with age range (35-55) years old, who were carefully informed about the aim of the investigation and were free to accept or refuse to be examined; all of them were selected from subjects attending private dental clinics. the subjects were divided into three groups: 1. group 1: 25 males with type 2 diabetes mellitus and chronic periodontitis (hba1c >7%) had received oral hypoglycemic medication. 2. group 2: 25 males with chronic periodontitis and no history of any systemic diseases. cp in patients was defined as the presence of at least four sites with ppd ≥ 4 mm and clinical attachment loss of (1-2) mm or greater. (14) 3. group 3: 20 males with healthy periodontium and systemically healthy. all the individuals had body mass index (bmi) levels ranging between 18.5 kg/m² 24.9 kg/m². exclusion criteria included participants who were diagnosed with sjögren's syndrome, rheumatoid arthritis or hiv, a participant who is on antihypertensive, antihistamines, antidepressants or antipsychotic medications; a participant who had head and neck radiation therapy and smoking or alcohol drinking. clinical periodontal parameters included plaque index (pl.i) (15), gingival index (g.i) (16), probing pocket depth (ppd) and clinical attachment level (cal). the unstimulated salivary samples were collected from all participants under standard conditions. (17) the subject should not eat or drink except having water one hour before the collection of saliva. the subject was asked to rinse his mouth thoroughly with water to insure the removal of any possible debris or contaminating materials and waiting (1-2) minute for water clearance. when resting saliva is collected, the subject is asked to sit in a relaxed position with elbows resting on knee and head hanging down between the arms. the lips are only slightly open and the subject lets the saliva drool passively over the lower lip into the test tube. saliva should not be spat into the test tube. saliva was collected between 9-12 am and the collection period was 5 minutes. salivary ph was then measured using the ph indicating paper. the indicator strip was dipped in the saliva for 30 s and the color on the strip was compared with the standard color chart provided by the manufacturer. statistical analyses: the study variables were statistically analyzed by using mean, standard deviation, and student t-test, at a level of significance of p < 0.05. results the descriptive statistics for pl.i and g.i are shown in table (1). it was clearly shown that the means of pl.i and g.i were elevated in group 1 compared with groups 2 and 3. intergroup comparison of pl,i and g.i using student t-test revealed a significant difference between group i and group 2 and there was high significant difference between group i and group 3, as well as between group 2 and group 3 as shown in table (2). table (3) shows the descriptive statistics for ppd and cal for group 1 and group 2. the mean was elevated in group 1 compared with group 2 with significant difference as shown in table (4). the descriptive statistics for sfr and ph is shown in table (5). it was clearly shown that the means were lower in group 1 compared with groups 2 and 3. intergroup comparison of sfr using student ttest revealed a high significant difference between group 1 and group 2 and between group 1 and group 3 but there was no significant difference between group 2 and group 3 as shown in table (6). intergroup comparison of ph using student t-test revealed a high significant difference between group i and group 2 and between group 1 and group 3 and there was significant difference between group 2and group 3 as shown in table (6). table (1): descriptive statistics (mean ±sd) of plaque and gingival index in each group. g.i pl.i statistic g3 g2 g1 g3 g2 g1 0.08 1.75 2.50 0.08 2.04 2.42 mean 0.01 0.41 0.38 0.13 0.32 0.21 sd± table (2): inter group comparison of mean of plaque and gingival indices with significant difference between groups. g.i pl.i g ro u p s s ig p -v a lu e tte st s ig p -v a lu e tte st s 0.025 3.236 s 0.013 2.524 g1 & g2 hs 0.001 5.316 hs 0.001 6.535 g1 & g3 hs 0.000 6.615 hs 0.00 7.188 g2 & g3 j bagh college dentistry vol. 32(2), june 2020 effect of diabetes 14 table (3): descriptive statistics (mean ±sd) of ppd and cal in each group. statistic ppd cal g 1 g2 g1 g2 mean 5.28 4.78 5.46 4.82 sd± 0.42 0.23 0.27 0.35 table (4): inter group comparison of mean of ppd and cal between g1 & g2. cal ppd g ro u p s s ig p -v a lu e tte st s ig p -v a lu e tte st s 0.03 2.05 s 0.02 2.78 g1 & g2 table (5): descriptive statistics (mean ±sd) of salivary flow rate and salivary ph in control and test group. table (6): inter group comparison of mean of salivary flow rate and salivary ph between groups. discusion result outcomes revealed a significant difference in pl.i between group i (diabetic patients with chronic periodontitis) and group 2 (systemically healthy patients with chronic periodontitis) and high significant difference between group i and group 3 (systemically healthy patients with healthy periodontium ), as well as between group 2 and group 3.these were in agreement with the results of studies (18-21) which found t2 diabetic patients had more sites with plaque than did nondiabetics. but this study disagrees with other studies which (22,23) found that there was a non-significant difference in pli among controlled, uncontrolled t2 diabetics and non-diabetics. these findings underline the fact that patients with diabetes tend to be systemically compromised and that their oral environment is also compromised due to the reduction in the buffering capacity and volume of their saliva, increased salivary viscosity and the change in bacterial flora. (24) significant differences were found in g.i between group 1 and group 2, as well as, a high significant difference found between group 2 and group 3 and between group 1 and group 3. so our results were in agreement with other studies (19,25) who found that there is a significant difference in gingival health between controlled and uncontrolled t2 diabetics, as well as, agreed with studies who found that there is a significant difference between (t2 diabetic and non-diabetic patients) with pd. (18,26) our results disagreed with study who found that there is a non-significant difference in gi between controlled and uncontrolled t2 diabetic patients. (27) diabetes is often associated with increased gingival inflammation in response to bacterial plaque. this response may be related to the level of glycemic control, thus subjects with poorly controlled dm have significantly increased inflammation. the inflammatory reactions are intensified during poor metabolic control, as the same amount of plaque causes more gingival bleeding in poorly controlled subjects compared to well control subjects. regarding the ppd, the present study clarified that the statistical difference between group 1 and group 2 was significant. this result was in acceptance with other studies, (28-31) while in disagreement with other studies (21, 23) which found non-significant variance in ppd between t2dm and non-diabetic patients. the dm causes increase in the production of proinflammatory cytokines like il-6 by human gingival fibroblasts when compared to nondiabetic. (32) when the severity of hyperglycemia rises, the periodontal inflammatory response also rise. (30) so, the periodontal parameters became worse in hyperglycemia than in normoglycemic patients. (31) the results of comparison of cal demonstrated a significant difference between group 1 and 2. this was in agreement with other studies (28,29,33) who reported that cal was higher with a significant difference in patients with t2dm compared to non-diabetic patients with cp. these findings in disagreement with other results. (21) raising in cal reported to be associated with high level of glycemic control. (8) the diabetes has been associated with reduction in neutrophils functions (adherence, chemotaxis and phagocytosis) this will lead to more pathogen's proliferation and more periodontal tissue inflammation, so individuals with diabetes have higher incidence, prevalence and severity of periodontitis when compared to non-diabetics. (34) ph sfr g ro u p s s ig p -v a lu e tte st s ig p -v a lu e tte st hs 0.000 6.147 hs 0.000 7.809 g1 & g2 hs 0.001 4.198 hs 0.001 5.914 g1 & g3 s 0.040 2.132 ns 0.743 0.965 g2 & g3 ph salivary flow rate (ml/min) statistic g3 g2 g1 g3 g2 g1 7.14 6.82 6.12 0.69 0.67 0.61 mean 0.27 0.16 0.12 0.41 0.03 0.11 sd± j bagh college dentistry vol. 32(2), june 2020 effect of diabetes 15 the results of this study showed a significantly reduced salivary flow rates in diabetic patients when compared with non-diabetic individuals. this result is also supported by findings from different studies. (35-37) salivary flow rate was significantly diminished in diabetics as compared to that in non-diabetics can be explained that the thirst and dry mouth characteristic of diabetics was related to the poor glycaemic control in diabetics, which in turn, was associated with increased diuresis and fluid loss. the present study demonstrated that when the patients with diabetics were compared with the patients without diabetes, diabetic patients had decreased salivary ph values. this result was in agreement with other studies. (38-40) this causes changes in the metabolic processes due to increased glucose levels, resulting in a more acidic environment and thus associated with periodontitis. the effect could be secondary to decreased salivary flow rates and ph value that leads a series of plaque risk factors especially if the disease is inadequately controlled and uncontrolled. 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85(6): 510-514. 34. mealey bl, oates tw. diabetes mellitus and periodontal diseases. j periodontol. 2006;77:12891303. 35. lasisi tj, fasanmade aa. salivary flow and composition in diabetic and non-diabetic subjects. niger j physiol sci. 2012;27:79-82. 36. engström pe. self-perceived oral health and salivary proteins in children with type 1 diabetes. j oral rehab. 2009;36:39– 44. 37. robo i, mavriqi l, milo eg, heta s, alliu n. saliva as an indicator of diabetes in oral cavity. arch dent oral health. 2018;1:18-25. 38. umamaheswari tn, srineeraja p. study of salivary ph in patients with the prevalence of periodontitis with or without diabetes mellitus. asian j pharm clin res. 2016;9:393-395. 39. puttaswamy ka, puttabudhi jh, raju s. correlation between salivary glucose and blood glucose and the implications of salivary factors on the oral health status in type 2 diabetes mellitus patients. j int soc prev community dent. 2017;7:28-33. 40. iqbal w, noori s, rehman a, shah sh, mudassir h. association of salivary flow rate and ph of diabetes mellitus type ii subjects with dental caries and gingivitis. ec dent sci. 2018;11:1823-1828. 41. mealey bl, oates tw. diabetes mellitus and periodontal diseases. j periodontol. 2006;77:1289303. الخالصه .ساع من االمراض المزمنه وتوجد عالقه ثناثيه بينهمايعتبر مرض السكري والن : الخلفيه النوع من السكري لمرضى الدراسة لمجموعات للثة الصحية الحالة : هو تقيم ومقارنه الشده فيالدراسة أهداف .وكذلك كميه تدفق اللعاب وحموضيته لدى المجموعتين مزمن نساغ لديهموكليهما بالسكري المصابين وغير الثاني الى االشخاص تقسيم تم. فقط ذكور وكانوا 55-35 من العمرية الفئة مع الدراسة في شخص سبعون التحق: والطرق المواد مصاب غير مريضا 25السكري والمجموعه الثانيه تتكون من مع مريضا 25 من تتكون االولى مجموعات,المجموعة ثالث بطة. ضا كمجموعة ،صحية لديهم واللثة شخص اصحاء 20 تتكون الثالثه والمجموعة ،منمز نساغ لديه منهم كل، بالسكري ومستوى اللثة جيوب عمق اللثة، مؤشرالتهاب الجرثومية، مؤشرالصفيحة ذلك في بما السريرية االسنان ماحول مؤشرات درجة الدراسه لغرض تحديد في شارك شخص كل من محفز الغير اللعاب من عينات جمع تم. سريريا الرابطة االنسجة .اللعاب سريان ومعدل والقاعديه الحموضه لدىالمجوعه االولى مقرنه يالمجاميع أعلى كانت السريرية االسنان حول ما مؤشرات جميع أن النتائج أظهرت : النتائج اللعاب ومعل الحموضه والقاعديه اقل لدى المجموعه االولى بفرق معنوي مقرنه الثانيه بفروق معنويه وكان معدل سريان .بالمجاميع االخرى المصابين غير مرضى اكثرمن اللثة انسجة التهاب شديد في اظهروا الثاني النوع السكري مرض انه استنتاج تم : االستنتاج . بالسكرمع انخفاض في معدل سريان اللعاب وزياده حموضيته http://www.jispcd.org/searchresult.asp?search=&author=kavitha+a+puttaswamy&journal=y&but_search=search&entries=10&pg=1&s=0 http://www.jispcd.org/searchresult.asp?search=&author=jaishankar+h+puttabudhi&journal=y&but_search=search&entries=10&pg=1&s=0 http://www.jispcd.org/searchresult.asp?search=&author=shashidara+raju&journal=y&but_search=search&entries=10&pg=1&s=0 ghasaq.doc j bagh college dentistry vol. 27(1), march 2015 assessment of some oral and maxillofacial surgery and periodontics 138 assessment of some salivary enzymes levels in type 2 diabetic patients with chronic periodontitis (clinical and biochemical study) ghasaq a. abdul-wahab, b.d.s. (1) maha a. ahmed, b.d.s., m.sc. (2) abstract background: diabetic patients have been reported to be more susceptible to gingivitis and periodontitis than healthy subjects. many intracellular enzymes like (alkaline phosphatase(alp), aspartate aminotransferase(ast) and alanine aminotransferase(alt) that are released outside cells into the gingival crevicular fluid (gcf) and saliva after destruction of periodontal tissue during periodontitis. this study was conducted to determine the periodontal health status and the levels of salivary enzymes (alp, ast and alt) of the study and control groups and to correlate the levels of these enzymes with clinical periodontal parameters in each study group. subjects, materials and methods: one hundred subjects were enrolled in the study, with an age range of (35-50) years, only males were included. the subjects were divided intostudy groups (group-i consists of 30 patients with controlled type 2 diabetes mellitus(t2dm), group-ii consists of 30 patients with uncontrolled t2dm, group-iii consists of 25 patients non-diabetics, all of them have chronic periodontitis(cp) and group-iv consists of 15 apparently systemically healthy subjects and have healthy periodontium, as control group. unstimulated saliva samples were collected for biochemical analysis of salivary enzymes (alp, ast and alt).the clinical periodontal parameters including: plaque index (pli), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal) were recorded for all subjects at four sites per tooth except third molars. results: all clinical periodontal and biochemical parameters were highest in uncontrolled t2dm with cp patients and all enzymes levels revealed highly significant differencesbetween all pairs of the study and control groups except ast enzyme level which demonstrated a non-significant difference between controlled t2 diabetics with cp and nondiabetics with cp. there were weak correlations between all clinical periodontal parameters and biochemical parameters except between ppdand alt enzyme in non-diabetics with cp group and between cal and ast enzyme in uncontrolled t2 diabetics with cp which demonstrated highly significant strong positive correlations. conclusion: it was concluded that t2dm and poor glycemic control have negative impact on periodontal health status. salivary enzymes were considered as good biochemical markers of periodontal tissue destruction and useful in diagnosis, monitoring and efficient management of periodontal diseases and t2dm. key words: enzymes, saliva, type 2 diabetes mellitus, periodontal diseases. (j bagh coll dentistry 2015; 27(1):138-143). introduction diabetes mellitus (dm) is an extremely important disease from a periodontal standpoint. it is a multi-systemic metabolic disorder characterized by abnormal carbohydrate, protein and lipid metabolism, the cardinal biochemical feature of this disease is elevated levels of glucose in the blood (hyperglycemia) (1) chronic hyperglycemia has been closely associated with an inflammatory response that has been linked to many complications (microvascular and macrovascular complications) observed in diabetes (2). t2dm is the more prevalent of the two major categories of overt diabetes and accounts for 90-95% of all diabetic cases and usually has an adult onset; it combines insulin resistance (ir) and insulin secretory defect (1,3). periodontal diseases (pds) are one of the most widely spread diseases of mankind; they are considered an inflammatory disorder that damages tissues. the most common form of pd is called chronic periodontitis (cp) which described as a (1) master student, department of periodontics, college of dentistry, university of baghdad. (2) assistant professor, department of periodontics, college of dentistry, university of baghdad. multifactorial, irreversible and cumulative condition, initiated and propagated through the complex interactions between periodontopathic bacteria and the host defense system (4-6). so, it’s considered the most important cause of tooth loss during adulthood (7). systemic diseases are among risk factors of pd. dm and pd are thought to be associated biologically; dm is believed to promote periodontitis through an exaggerated inflammatory response to the periodontal microflora (8). it has been shown that uncontrolled or poorly controlled dm has the greater incidence of severe pd compared with those patients who are well controlled or have no dm, which has been more prevalent in persons with t2dm(9-11) . saliva is a complex fluid that influences oral health through specific and non-specific physical and chemical properties. when disruptions in the quality or quantity of saliva occur, there will often be detrimental effects on oral and systemic health. saliva is a mirror of general health. the diverse salivary constituents provide sources for assessment and monitoring of health and disease states (12). j bagh college dentistry vol. 27(1), march 2015 assessment of some oral and maxillofacial surgery and periodontics 139 host responses to pd include the production of different enzymes that are released by stromal, epithelial or inflammatory cells. in addition to this, various enzymes associated with cell injury and cell death can be detected in gcf and saliva. several enzymes are evaluated for early diagnosis of pd such as alp, ast and alt (13-15). there has been correlation between t2dm, pd and numerous markers in saliva, such as intracellular enzymes (16).these enzymes may be used to test the activity of pds (17). subjects, materials and method the subjects consisted of 100 males with age range of (35-50) years. the subjects recruited for the study were patients attending the specialized center for endocrinology and diabetes in baghdad, as well as, patients from the department of periodontics, at teaching hospital, college of dentistry, university of baghdad. all the individuals were informed about the purposes of the investigation and consented to its protocol.the subjects were divided into: 1) study group (g-i): consists of (30) males with cp and t2dm, well controlled, the hba1c were <7%. 2) study groupii(g-ii):consists of (30) males with cp and uncontrolled t2dm (moderately and poorly controlled), the hba1c were >7%. 3) study group iii (g-iii): consists of (25) males with cp and without history of any systemic diseases. 4) control group iv (g-iv): consists of (15) males without history of any systemic diseases and with healthy periodontium, this was defined by gi scores <0.5(18) and without periodontal pockets or clinical attachment loss. this group represents a base line data for the levels of salivary alp, ast and alt. inclusion criteria include t2dm patients (≥5 years) on oral hypoglycemic medication, body mass index level ranges between 18.5 kg/m² 24.9 kg/m² (19), all subjects were presenting at least 20 teeth and cp in patients was defined as the presence of at least four sites with ppd ≥ 4 mm and clinical attachment loss of (1-2) mm or greater, this made according to the international classification system for pd (20). exclusion criteria include t1 and t2 diabetic patients taking insulin therapy, presence of other systemic diseases other than diabetes, presence of retinopathy, neuropathy or diabetic foot, patients who have undergone periodontal treatment and course of anti-inflammatory or antimicrobial therapy 3 months prior to the study, gross oral pathology such as oral cancer and smoking or alcohol drinking. from each subject, (5ml) of unstimulated whole saliva was collected; the collected saliva was centrifuged at 4000 rpm for 15 minutes and then the clear supernatant saliva was collected and kept frozen and stored at -20 ˚ c until biochemical analysis of salivary enzymes. clinical periodontal parameters examination was performedafter salivary sample collection by using michigan o periodontal probe on four surfaces (mesial, buccal/ labial, distal and lingual/ palatal) of all teeth except third molar. the collected data include: 1. assessment of soft deposits by the plaque index system (pli) (21). 2. assessment of gingival inflammation by the gingival index system (gi) (18). 3. assessment of gingival bleeding on probing (bop) 4. assessment of probing pocket depth(ppd) 5. assessment of clinical attachment level (cal) for alp enzyme analysis we used kit manufactured by (biomereiux ® sa), while for ast and alt enzymes analysis we used kits manufactured by (randox /uk). the activity of alp was determined by measuring its absorbance at 510 nm, while the activities of ast and alt were determined by measuring the absorbance at 505 nm both by the spectrophotometer. descriptive statistics in the form of mean, standard deviation, percentage and inferential statistics in the form of games –howell, lsd, chi-square and pearson correlation were used in this study. the level of significance was accepted at p< 0.05, highly significance at p< 0.01 and non-significant at p> 0.05. results a-clinical periodontal parameters: the results showed that all clinical periodontal parameters were highest in uncontrolled t2 diabetics with cp followed by non-diabetics with cp then controlled t2 diabetics with cp except for ppd which was highest in uncontrolled followed by controlled t2 diabetics both with cp then non-diabetic patients with cp ,as shown in (table -1). highly significant differences were demonstrated by using chi-square test for the comparisons between each two study groups regarding the percentages of bop sites in addition, comparisons between all pairs of the study groups revealed significant and highly significant differences (p<0.01) regardingthe j bagh college dentistry vol. 27(1), march 2015 assessment of some oral and maxillofacial surgery and periodontics 140 other clinical periodontal parameters except for ppd and cal between controlled t2 diabetics with cp and non-diabetics with cp which were non-significant differences (p>0.05), as shown in (table-2). bbiochemical analysis: the obtained results have shown that the mean concentrations of salivary enzymes (alp, ast and alt) were highest in uncontrolled t2 diabetics with cp followed by controlled t2 diabetics with cp then non-diabetics with cp and finally control group,as shown in(table-3).inter groups comparisons for all enzymes levels revealed highly significant differences (p <0.01) between all pairs of the study and control groups except ast enzyme level which demonstrated a non-significant difference(p>0.05) between controlled t2 diabetics with cp and non-diabetics with cp (table-4). c-correlation of alp, ast and alt enzymes levels with clinical periodontal parameters: there were weak correlations between all clinical periodontal parameters and biochemical parameters except between ppdand alt enzyme in non-diabetics with cp group and between caland ast enzyme in uncontrolled t2 diabetics with cpwhich demonstrated highly significant positive strong correlations.significant positive correlations were revealed between pli and ast enzyme in controlled t2 diabetics with cp, between gi and alp enzyme in uncontrolled t2 diabetics with cp, as well as, cal with both ast enzyme in controlled t2 diabetics with cp and alt enzyme in uncontrolled t2 diabetics with cp and non-diabetics with cp, as shown in (table-5). table 1: statistical description (mean ± sd) of (pli, gi, ppd and cal) and percentages of sites according to bop scores for the study and control groups groups pli gi bop ppd cal mean±sd mean±sd score 0 score 1 mean ±sd mean ±sd gi 1.62 ± 0.59 1.61 ± 0.63 61.39 % 38.61 % 4.47±0.63 4.187±1.578 gii 2.69 ± 0.37 2.79 ± 0.39 2.16 % 97.84 % 5.03±0.43 5.913±1.439 giii 2.05 ±0.68 2.00 ± 0.55 49.76 % 50.24 % 4.42±0.56 4.74±1.836 giv 0.12 ± 0.09 0.09 ± 0.08 table 2: intergroups comparisons of the mean values of pli, gi, ppd, caland the percentages of bop sites between all pairs of the study groups groups pli gi bop ppd cal p sig. p sig. p sig. p sig. p sig. gi gii 0.000 hs 0.000 hs 0.000 hs 0.000 hs 0.000 hs g -iii 0.042 s 0.046 s 0.000 hs 0.753 ns 0.209 ns g-ii g -iii 0.000 hs 0.001 hs 0.000 hs 0.000 hs 0.009 hs table 3: statistical description (mean level in iu/l ± sd) of alp, ast and alt enzyme for the study and control groups groups alp ast alt mean± sd mean± sd mean± sd gi 9.487 ± 1.983 14.533 ± 1.624 10.27 ± 0.89 gii 14.587 ± 2.541 18.433 ± 1.165 13.25 ± 1.96 giii 7.888 ± 1.15 13.56 ± 2.053 8.34 ± 1.24 giv 5.993 ± 0.823 9.533 ± 1.506 5.07 ± 1.52 table 4: inter groups comparisons of the mean concentrations (iu/l) of alp, ast and alt enzymes between all pairs of the study and control groups by using games-howell method groups alp ast alt p-value sig. p-value sig. p-value sig. gi gii 0.000 hs 0.000 hs 0.000 hs g-iii 0.003 hs 0.233 ns 0.000 hs g-iv 0.000 hs 0.000 hs 0.000 hs g-ii giii 0.000 hs 0.000 hs 0.000 hs giv 0.000 hs 0.000 hs 0.000 hs giii giv 0.000 hs 0.000 hs 0.000 hs j bagh college dentistry vol. 27(1), march 2015 assessment of some oral and maxillofacial surgery and periodontics 141 table 5: person's correlation coefficient (r) between clinical periodontal parameters and the levels of salivary enzymes for each study group alp enzyme pli gi bop ppd cal r p r p r p r p r p g-i 0.058 0.380 0.221 0.120 0.137 0.469 0.023 0.452 0.224 0.117 g-ii 0.215 0.127 0.379 0.020 0.024 0.901 0.042 0.414 0.202 0.142 g-iii 0.034 0.435 0.012 0.478 0.001 0.996 0.012 0.477 0.003 0.494 ast enzyme r p r p r p r p r p g-i 0.420 0.010 -0.222 0.119 -0.245 0.192 -0.099 0.302 0.379 0.019 g-ii 0.110 0.281 0.006 0.487 -0.254 0.088 -0.003 0.494 0.563 0.001 g-iii 0.105 0.308 0.185 0.189 0.222 0.286 0.12 0.284 0.198 0.171 alt enzyme r p r p r p r p r p g-i -0.125 0.256 0.047 0.402 0.114 0.547 -0.119 0.265 0.115 0.273 g-ii -0.137 0.236 0.165 0.192 -0.050 0.792 -0.015 0.468 0.414 0.011 g-iii 0.243 0.121 -0.269 0.097 0.365 0.073 0.523 0.004 0.424 0.017 discussion in the present study significant statistical differences were found between controlled t2 diabetic patients with cp and non-diabetics with cp and highly significant differences were found between uncontrolled t2 diabetics and both controlled t2 diabetics with cp and non-diabetics with cpregarding pli and gi. these were in agreement with other studies (22-24) and in disagreement with ibrahem and abaas (25) and sharma et al (26).these are explained by the fact that patients with diabetes tend to be systemically compromised and that their oral environment is also compromised due to the reduction in the buffering capacity and volume of their saliva, increased salivary viscosity and the change in bacterial flora(27, 28). all these factors lead to higher accumulation of plaque and calculus. diabetes is often associated with increased gingival inflammation in response to bacterial plaque as the inflammatory reactions are intensified during poor metabolic control (8). the result of this study revealed that the uncontrolled diabetics have more sites with bleeding on probing than controlled and nondiabetic groups and this was in agreement with offenbacher et al (29) and in disagreement with kumar et al (30). regarding ppd and cal the results represent highly significant differences were found between uncontrolled t2 diabetic patients with cp and both controlled t2dm and non-diabetic patients with cp. these results were in agreement withstudies (31, 32) and in disagreement with other study (33). this result may be explained by the fact that poor glycemic control, with the associated increase in advanced glycation end products, renders the periodontal tissues more susceptible to destruction. the cumulative effects of altered cellular response to local factors, impaired tissue integrity and altered collagen metabolism as the collagen in diabetic patients is aged and more susceptible to breakdown (34), these undoubtedly play a significant role in the susceptibility of diabetic patients to infections and destructive pd. there were increased bop, ppd, increased tooth mobility and greater loss of attachment as the individuals with diabetes are twice as likely to exhibit attachment loss as non-diabetic individuals (35). numerous markers in saliva have been proposed as adiagnostic test for periodontal disease such as (alp, ast and alt) enzymes. these intracellularenzymes are increasingly being released by sickperiodontal tissues into the gcf andsaliva where their activity can be estimated. from the present study findings revealed that the level of alp was higher in diabetic groups than in non-diabetics and control groups, the observed high enzyme activity can be attributed to increase in inflammation and bone turnover rate as alp enzyme is produced by polymorphonuclear leukocytes,osteoblasts, macrophages, fibroblasts and plaque bacteria within periodontal tissues or pockets. the increased alp activity is probably a consequence of destructive process in the alveolar bone in the advanced stages of pd (13). the present findings revealed that there were highly significant differences in salivary alp levels between all pairs of the study groups and with control group. this is in accordance with many other studies (16, 35). the result of this study showed highly significant difference in salivary ast level between all pairs of the study groups and with the control group except between controlled t2 diabetics and non-diabetics both with cp, which was non-significant. this result was in agreement with studies (16,36), regarding alt enzyme the results revealed that there were highly significant j bagh college dentistry vol. 27(1), march 2015 assessment of some oral and maxillofacial surgery and periodontics 142 differences in enzyme level between all pairs of the study groups and with control group, this was in agreement with previous studies(16,37) .there were weak non-significant positive correlations between alp and clinical periodontal parameters (pli, bop, ppd and cal) in all study groups, while there is a significant positive correlation between alp and gi in uncontrolled t2 diabetics with cp group. these results were in agreement with kalburgi et al (35) and sanikop et al (38) and in disagreement with kumar sharma (39). the possible explanation of weak non-significant correlation may be due to limited human sample size. regarding the ast enzyme there were a highly significant strong positive correlation between salivary ast and cal within uncontrolled t2 diabetic patients with cp, and significant positive correlation between ast enzyme and both pli and cal parameters within controlled t2 diabetic patients with cp. these findings agreed with abdulhadi (40) and in disagreement with other study (15). the findings revealed that there 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patients with different degrees of metabolic control. acta odontol latinoam 2012; 25(1):132-9. 23. tanwir f, tariq a. effect of glycemic conrol on periodontal status. j coll physicians surg pak 2012; 22(6):371-4. 24. casarin rcv, barbagallo a, meulman bt, santos vr, sallum ea, nociti fh, duarte pm, casati mz, gonc¸ alves rb. subgingival biodiversity in subjects with uncontrolled type-2 diabetes and chronic periodontitis. j periodont res 2013; 48: 30–6. 25. ibrahem lm. , abaas rf, periodontal health status and biochemical study of saliva among diabetics and non-diabetics (comparative study). must dent j 2007; 4(1):1-4. j bagh college dentistry vol. 27(1), march 2015 assessment of some oral and maxillofacial surgery and periodontics 143 26. sharma r, raj ss, vinod k, reddy yg, desai v, bailoor d. comparison of oral health indicators in type 2 diabetes mellitus patients and controls. j of indian academy of oral medicine and radiology 2011; 23(3): 168-72. 27. hintao j, teanpaisan r, chongsuvivatwong v, dahlen g, rattarasarn c. root surface and coronal caries in adults with type 2 diabetes mellitus. community dent oral epidemiol 2007; 35(4): 302–309. 28. preetha p, kim k, eun s, inglehart, rohr m. diabetes and oral health: the importance of oral health– related behavior 2011; 85: 264-72. 29. offenbacher s, barros s, singer r, et al. periodontal disease at the biofilm-gingival interface. j periodontol. 2007; 78: 1911–25. 30. kumar a, pandey mk, singh a, mittra p, kumar p. prevalence and severity of periodontal diseases in type 2 diabetes mellitus of bareilly region (india). int j med sci public health 2013; 2: 77-83. 31. stojanović n, krunić j, cicmil s, vukotić o. oral health status in patients with diabetes mellitus type 2 in relation to metabolic control of the disease. srp arh celok lek 2010; 138(7-8): 420-4. 32. haseeb m, khawaja ki, ataullah k, munir mb, fatima a. periodontal disease in type 2 diabetes mellitus. j coll physician surg pak 2012; 22(8): 5148. 33. mealey bl. periodontal disease and diabetes: a two-way street. jada 2006; 137(10): 26-31. 34. carranza, newman, taki and klokkevold. carranza’s clinical periodontology. 11th ed. elsevier, saunders: 2012. (chapter 4,p 41-42) and (chapter 27, p 305308). 35. kalburgi v, jenifer hd, warad s, bhola s, chaudhari hl. comparison of salivary alkaline phosphatase levels among diabetics and non-diabetics with chronic periodontitis. j oral health research 2010; 1(4):14752. 36. al-rubaee ea, kadum ha, al-braich ms. salivary aspartate amino transferase and alanine amino transferase of non-insulin-dependents (type2) diabetic patients. j fac med baghdad 2010; 521(2): 212-214. 37. dhiraj t, chhaya t. salivary proteome in periodontal diagnosis. int j pharma and bio sci 2012; 3(2): 241245. 38. sanikop s, patil s, agrawal p. gingival crevicular fluid alkaline phosphatase as a potential diagnostic marker of periodontal disease. j indian soc periodontol 2012; 16(4): 513–8. 39. kumar r, sharma g. salivary alkaline phosphatase level as diagnostic marker for periodontal disease. j. int oral health 2011; 3(5): 81-86. 40. abdul-hadi mj. evaluation of salivary enzymes activities among patients with chronic periodontitis. a master thesis/ department of periodontology. college of dentistry, university of baghdad, 2009. 41. rai b, kharb s, anand s.c. salivary enzymes and thiocynate: salivary markers of periodontitis among smokers and non-smokers; a pilot study. adv in med dent sci 2007; 1(1): 1-4. الخالصة اسبارتیت امینو ترانسفیریز و , الكاالین فوسفاتیز( العدید من االنزیمات داخل الخالیا مثل. ان مرضى السكري أكثر عرضة اللتھاب اللثة والنساغ من االشخاص االصحاء: الخلفیة لذا اعدت ھذه الدراسة لتحدید الحالة الصحیة للثة ومستویات . تفرز خارج الخالیا الى السائل الشقي اللثوي واللعاب بعد تدمیر األنسجة اللثویة اثناء النساغ) االنین امینوترانسفیریز .ثم لربط مستویات ھذه االنزیمات مع مؤشرات ما حول االسنان السریریة في كل مجموعة دراسة,والظابطة االنزیمات اللعابیة لمجموعات الدراسة المجموعة االولى (تم تقسیم االشخاص الى مجموعات الدراسة . سنة، وكانوا ذكور فقط) ٥٠-٣٥(التحق مائة شخص في الدراسة مع الفئة العمریة من :المواد والطرق, االشخاص والمجموعة الثالثة تتكون , مریضا مع السكري من النوع الثاني الغیرمسیطرعلیھ ٣٠مریضا مع السكري من النوع الثاني المسیطر علیھ ، المجموعة الثانیة تتكون من ٣٠ن تتكون م تم جمع عینات من .كمجموعة ظابطة, شخصا اصحاء واللثة لدیھم صحیة ١٥والمجموعة الرابعة تتكون من , مریضا غیر المصابین بالسكري، كل منھم لدیھ نساغ مزمن ٢٥من الكاالین فوسفاتیز ، االنین امینوترانسفیریز واالسبارتیت (شارك في الدراسة الجراء التحلیل الكیمیائي الحیوي لإلنزیمات اللعابیة اللعاب الغیر محفز من كل شخص للثة و مستوى االنسجة الرابطة مؤشرات ماحول االسنان السریریة بما في ذلك مؤشرالصفیحة الجرثومیة، مؤشرالتھاب اللثة، مؤشرالنزف عند التسبیر، عمق جیوب ا).امینوترانسفیریز .سریریا سجلت لكل شخص في الدراسة وألربعة اسطح في كل سن باستثناء الرحى الثالثة االنزیمات ن وكل مستویات كل مؤشرات ماحول االسنان السریریة والمؤشرات الكیمیائیة كانت اعلى لمرضى السكري من النوع الثاني الغیر مسیطر علیھ ولدیھم نساغ مزم :النتائج مرضى السكري من النوع الثاني المسیطر اظھرت فروقات معنویة عالیة بین كل ازواج المجامیع الدراسة والظابطة ماعدا مستوى االنزیم االسبارتیت امینوترانسفیریز بین مجموعتي ة ضعیفة بین مؤشرات ماحول االسنان السریریة والمؤشرات الكیمیائیة ماعدا ھناك عالق.علیھ مع نساغ مزمن وغیرالمصابین بالسكري مع نساغ مزمن الذي اظھر فرق غیر معنوي مستوى االنسجة الرابطة سریریا وانزیم بین مؤشر عمق جیوب اللثة وانزیم االنین امینوترانسفیریز لدى مجموعة غیر المصابین بالسكري من النوع الثاني مع نساغ مزمن وبین مؤشر .یز في مجموعة مرضى السكري من النوع الثاني الغیر مسیطر علیھ مع نساغ مزمن التي اظھرت عالقة ایجابیة قویة معنویة عالیةاالسبارتیت امینوترانسفیر اللعابیة كعالمات كیمیائیة تعتبر االنزیمات. تم استنتاج انھ مرض السكري النوع الثاني وسوء السیطرة على نسبة السكري في الدم لھا تاثیر سلبي على صحة ماحول االسنان :االستنتاج .المراقبة والسیطرة الجیدة على امراض اللثة والسكري من النوع الثاني, حیاتیة جیدة لالنسجة اللثویة المحطمة وھذا یوفر فرصة جیدة للتشخیص 6. basima f.doc j bagh college dentistry vol. 27(4), december 2015 preparation and restorative dentistry 32 preparation and evaluation of some properties of heat cured acrylic based denture soft liner basima m. a. hussein, b.d.s., m.sc., ph.d. (1) salem a. salem, b.d.s., d.d.s., ph.d. (2) salah m. aliwi, b.d.s., ph.d. abstract background: the base of the denture is largely responsible for providing the prosthesis with retention, stability, and support by being closely adapted to the oral mucosa. however; the process of bone resorption is irreversible and may lead to an inadequate fit of the prosthesis; this can be overcome by relining. materials and methods: acrylic based soft denture liner is prepared by preparing polymer from purified methylmethacrylate monomer with (10-2) initiator and (30%) dibutylphthalate plasticizer concentrations. biological properties were evaluated in comparison with the control material through subcutaneous specimens' implantation in the new zealand rabbits. excisional biopsies were taken after (1, 3, days 1, 2, 3, 4 weeks) period. microscopically, sections are studied to explore the consequences of thecontact with tested material and tissue response. tensile strength, percentage of elongation, compressive, bond, and peel strengthwere evaluated; as well as water sorption and solubility is compared with the control material. results: histological study of the sections contained experimental and control materials showed normal tissue response by normal infiltration of the inflammatory cells; acute in the first days then chronic inflammatory cells were seen in the subsequent periods. finally capsular enclosure of the specimens was well characterized and seen after 4 weeks. results of the mechanical properties showed non-significant differences for the tested properties except the percentage of elongation; control material recorded significantly higher value. moreover, statistically; water sorption of the experimental material was significantly lower than the control material; while the tested materials showed nonsignificant differences regarding the solubility test. conclusion: the recommended formula of preparing heat-cured; acrylic based denture soft liner showed acceptable properties. further evaluations of the experimental material were suggested. key words: heat cure, acrylic based soft liner. (j bagh coll dentistry 2015; 27(4):32-36). introduction relining is the procedure used to re-surface the tissue side of a removable dental prosthesis with a new base material, thus; producing an accurate adaptation to the denture foundation area(1). the use of soft denture liners is an important adjunct in the treatment of complete and partial denture patients, particularly those who are medically or locally compromised(2). the use of these materials act as a cushion for the denture bearing mucosa through absorption and re-distribution of the forces transmitted to the stress bearing area of the edentulous ridge. they are capable of restoring health to the inflamed mucosa(3,4) . in the past few years, soft liners have emerged in many fields to modify transitional prosthesis after stage i and stage ii implant surgery(5). the longevity of soft liner is a major problem; one problem is the adhesive failure between the liner and the denture base(6). in order to achieve success in relining process, wright (1982) concludes that same chemical composition of materials type is preferred because of the need for similar bonding properties(7), in other words, the (1)assistant professor. department of prosthodontics. college of dentistry, university of baghdad. (2)retired professor. main reason for failure of the soft liners is the structural difference between the two materials(8). furthermore, during the use of the relined denture, the materials usually immersed in saliva during regular use or soaked in water or aqueous cleaning solution at storage time. therefore; the material could be subjected to water sorption and degree of solubility. the present work is designed to prepare poly (methyl methacrylate) polymer, plasticized in a plane of preparing denture soft liner, heat cured acrylic type. it is intended to evaluate some of its chemical, biological and mechanical properties in comparison with other, commercially available denture soft liner material. materials and methods the preparation of the soft liner material was started by polymerization of purified methyl methacrylate monomer (fluka, switzerland).bulk polymerization method was selected to prepare polymers with range of dibenzoyl peroxide initiator(bdh chemical ltd) concentrations (5×10-2, 10-2 10-3, 10-4). viscosity average molecular weight was calculated for the prepared polymers and compared with the control, it was found that polymer with (10-2) concentration of dibenzoyl peroxide initiator was the closest polymer to the j bagh college dentistry vol. 27(4), december 2015 preparation and restorative dentistry 33 control regarding molecular weight. polymerization was done in a water bath (haake dc3-japan) at 74ºc for 30-35 minutes. the polymer then was precipitated using 1:5 volume of methanol (riedel-de haen). the collected polymer was dried in vacuum oven (gallenkamp) at 40ºc overnight. the dried polymer was milled and sieved to have particles<150µm.dibutyl phthalate was added to the monomer as a plasticizer before mixing with the prepared polymer in 30%. p/l ratio was calculated by a pilot study using different ratios; the decision was made depending on a result of uv absorption that determined the least residual monomer. processing of the material was done by using short curing cycle (90 minutes at 74 c and 30 minutes at 100ºc). processing of the control materialsuper soft, usawas done according to the manufacturer's instruction. biological properties: biocompatibility of the prepared denture soft liners was done by subcutaneous inoculation of (5 x2mm) discs of the materials in the dorsum of a newzeland rabbits. assessment of the tissue response toward the specimens was done by histological study of a slides prepared from biopsies excised after 1, 3, 7 days and 2, 3, 4, weeks. mechanical properties: tensile, compressive, peel and bond strength of the prepared material was tested and compared with those of the control material. tensile strength specimen was dumbbell shaped with (10×60×4mm) and the constricted part of the specimen was (8×2.5×4mm) was representing the tested material(9). tensile bond strength was tested using a specimen with (60×6×6mm), compressive strength with (40×12.7 mm)(10), all these test was performed after processing the soft denture liner(2mm) in the central part between two segments of heat cured acrylic specimens. peel test was performed by processing tested material in (70×10×2mm) against (70×10×2mm) heat cured acrylic bars(11). only 40 mm of the tested mayerialwas allowed to bond against the acrylic bar, the rest part of the specimen was reflected back to have 180º peel strength test. mechanical tests was performed by using instron testing machine (testometric ax, rochdale, uk) with cross head speed and grips adjusted according to each test. all the tests were performed under tensile loading except compressive strength was performed under compression. physical properties: water sorption and solubility test was performed by preparing discs with (50(±1) ×0.5(±0.05) mm)(12). the test was done following the ada specification no.12. statistical analysis included in the present study was mean, standard deviation and student ttest at a probability level (p< 0.05). results micrographs of the histological sections showed normal tissue response toward the inoculated materials. in the 1st 3-7 days infiltration of the acute anti-inflammatory cells as a neutrophil was seen, also new blood vessels, later on chronic inflammatory cells occupy the field. capsular connective tissues surrounding the specimens were well defined and almost no inflammatory cells seen after 4 weeks, figure (1). mechanical properties: the means of tested properties for the prepared material and the control are expressed in table (1) below. table (1): means and standard deviation of the tested mechanical properties with significance results significance (p<0.05) control experimental test n.s 1.11 (0.290) 1.301 (0.213) tensile strength(n/mm2) s 320 (59) 210 (43) elongation (%) n.s 1.631 (0.3) 1.579 (0.360) compressive strength(n/mm2) n.s 1.093 (0.27) 1.2 (0.24) bond strength(n/mm2) n.s 2.789 (0.492) 2.269 (0.501) peel strength(n/mm) s 3.095 (0.63) 1.7477 (0.394) water sorption(mg/cm2) n.s 0.22 (0.0421) 0.2191 (0.048) solubility j bagh college dentistry vol. 27(4), december 2015 preparation and restorative dentistry 34 a b c d e f figure (1): micrographs of tissue response toward tested materials, (a) after one day-mag. 50, (b) after three days –mag.200, (c) after 1 week-mag (50), (d) after 2 weeks with capsular formation, (e) after 2 weeks-mag.100 connective tissue capsule –mag.200-, (f) after 4 weeks-mag-200. discussion the use of soft denture liners is usually advantageous to avoid stress concentration(13), and to obtain retention for clinical cases with irritation of denture bearing mucosa and/or sever undercut area (14). the advantages of the soft denture liners were considered to be influenced by their properties. the material has cushioning effect that absorb load. it was concluded that permanent soft liner has elastic properties approximately within the range of the mucosal lining of the oral cavity(15). animal tests, using mammalians allow for a complex between the materials and biological environment to occur, thus the biological response is more comprehensive and more relevant than that obtained from other tests(16). acute inflammatory cells were invading the injured or irritated sites with increased vascularity and permeability; all are normal manifestations of acute inflammation. these findings were also agreed by craig and ward and stephenson. the same picture was seen as a response toward some of the tested metal alloys(17), or different types of acrylic(18), as well as implanted impression compound materials(19), and methacrylate-based endodontic sealer(20) and disagree with ozdemir et,al., who reported that some cytotoxic effect of certain types of denture soft liner(21), it was believed that many dental materials elicit cytotoxic response, but this does not necessarily reflect the long-term risk for adverse effects as the oral mucosa is generally more resistant to toxic substances than a cell culture(22). various in vitro and in vivo experiments and cell based studies conducted on acrylic based resins or their leached components have shown them to have cytotoxic effects. they can cause mucosal irritation and tissue sensitization. these studies are important to evaluate the long term clinical effect of these materials and help in further development of alternate resins(23). the main cause for such a response may be attributed to the leached plasticizers from the material during contact with the tissue(24). it must be understood that there are no inert materials. when a material is placed in a living tissues interaction with the complex biologic system this interaction depends on the material, the host and condition placed on the material. tensile strength provides information on the ultimate strength of the material in tension whereas elongation provides data on the ability of a material to stretch before failure occur(25). according to craig and ward(26), plasticized pmma demonstrate tensile strength rang (8.184.9 kg\cm2, relatively, 0.793-8.32 mpa)(26). the j bagh college dentistry vol. 27(4), december 2015 preparation and restorative dentistry 35 results of the tested materials in the present study are within this range. however; higher tensile strength value is not an absolute indication for the suitability of the material, accurately suitable value depends on the application of the material; rigid and even brittle materials may have high tensile strength but have their specific application rather than as a soft liner. craig and ward(26) showed that plasticized pmma could demonstrate percentage elongate range (150-300), the experimental material, in the present study, demonstrated elongation percentage within this average. however, the presence of ethyl group in the polymer chain of the control material may give more space between molecules that is why elongation was significantly higher than the experimental material. denture soft liner should have a superior cushioning effect during occlusion and mastication, many of these forces are compressive in nature, and therefore effect of compression load on the soft liner must be evaluated. during testing compressive load continued passing the soft liner segment to compress acrylic cylinders, this design of testing issimulate, in a degree, compressive load during function, in which load is transmitted to the soft liner through acrylic denture base. higher compressive strength of the control group may be due to the presence of ema polymer which is more resilient and elastic as well as it acts as addition plasticizer. bonding of the soft liners to the denture base material is very important, de-bonding or when separation does occur, the area may become unhygienic and nonfunctional. compatibility between denture base and the liner material is an important factor to be considered in studying the bonding failure. plasticized pmma (soft liner) and pmma denture base materials are similar in chemical structure. the use of a bonding agent considered unnecessary for these materials(27). the similarity in the chemical composition creates chemical bonding between these two materials. the success of soft lining materials depends partly on their adhesion to pmma and thus adhesion is best characterized in the laboratory by peeling test. the peel test is believed to simulate the horizontal component of the masticatory forces that cause lateral displacement of the denture. this displacement may cause stripping of the liner at the flanges of the denture(28). in the comparison between the experimental and the control materials, the nonsignificant differences in the values of peel strength of the two materials may indicate some similarity in the behavior of the tested materials. water sorption and solubility can dramatically affect dimensional stability stain resistance, physical and mechanical properties as tear strength, elongation, bond strength and resiliency(29). in the present study, water sorption test showed significant differences between the prepared and the control materials. this could be attributed to the lower p/l ratio recommended for the control material when compared with that of the experimental material. higher p/l ratio would produce dense specimens, eventually lead to less micro pockets of water; 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74(6): 595-601. 28. al-athel ms, jagger rg. effect of test method on the bond strength of a silicone resilient denture lining material. j prosthet dent 1996; 76(5): 535-40. 29. yanikoglu nd, duymus zy. comparative study of water sorption and solubility of soft lining materials in the different solutions. dent mater j 2004; 23(2): 233-9. 30. abdul-rahmann ba. evaluation of water sorption, solubility and bond strength of some soft lining material. a master thesis. department of prosthodontic. college of dentistry. university of baghdad, 2002. 31. braden m, wright ps. water absorption and water solubility of soft lining materials for acrylic dentures. j dent res 1983; 62(6): 764-8. 13. amir f.doc j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 85 an assessment of oral health in hypertensive patients treated with hmg-coa reductase inhibitors (statins) amir a. m. al-joboury, b.d.s. (1) rafil h. rasheed, b.d.s., m.sc. (2) abstract background: hypertension is a chronic medical condition in which the blood pressure in the arteries is elevated, it's classified as either primary (essential) hypertension or secondary hypertension, and it increases the risk of ischemic heart disease, peripheral vascular disease and other cardiovascular diseases. several classes of medications collectively referred to as antihypertensive drugs like beta blockers, calcium channel blockers, angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers, renin inhibitors and statins (hmg-coa) reductase inhibitor. statin medication may have some beneficial effects when subjects have dental plaque or signs of periodontitis as gingival bleeding. the purpose of this study were to assess the oral health in hypertensive patients are treated with statins in terms of salivary flow rate, ph and oral health indices. materials and methods: ninety saliva specimens collected from three groups of subjects (thirty healthy patients "control" group i), thirty hypertensive patients treated with anti-hypertensive medications without taking statins (group ii) and thirty hypertensive patients treated with anti-hypertensive medications with statins (group iii). unstimulated saliva was collected from each patients and participants for assessment of salivary flow rate and salivary ph. results: salivary flow rate is reduced in group ii and iii patients compared with group i. significant low salivary flow rate observed in group iii patients (hypertensive treated with statins) compared with group ii (hypertensive untreated with statins) and group i (healthy subjects); the median value of gingival index is significantly higher in group ii compared with corresponding value in group i, while it attended a significant low value in group iii patients; there is no significant difference in dmf score between group i and group iii, while a significant high score observed in group ii compared with group i ; the percent of carries restoration in patients of group ii is significantly low compared with corresponding value of group i . although the percent of carries restoration in patients of group iii is less than corresponding value of group i but it does not reach significant level. conclusions: patients using statins therapy are more likely have an improvement in gingival index, dmf score and carries restoration. the salivary flow rate is reduced in patients treated with statins medications, statins therapy have a beneficial effect on the oral cavity. key words: oral health, hypertension, statins, salivary flow rate. (j bagh coll dentistry 2015; 27(4):85-89). introduction hypertension or high blood pressure is a chronic medical condition in which the blood pressure in the arteries is elevated.(1) blood pressure is summarized by twomeasurements, systolic and diastolic, which depend onwhether the heart muscle is contracting (systole) or relaxedbetween beats (diastole) and equate to a maximum andminimum pressure, respectively. normal blood pressure atrest is within the range of 100-140mmhg systolic (top reading) and 6090mmhg diastolic (bottom reading). highblood pressure is said to be present if it is persistently at orabove 140/90 mmhg. hypertension puts persistent strain on the heart, leading tohypertensive heart disease and coronary artery disease ifuntreated. hypertension is also a major risk factor forstroke, aneurysms of the arteries (e.g. aortic aneurysm), peripheral arterial disease and is a cause of chronic kidney disease. dietary and lifestyle changes can improve blood pressure control and decrease the risk ofassociated health (1)master student. department of oral diagnosis. college of dentistry, university of baghdad. (2)professor. department of oral diagnosis. college of dentistry, university of baghdad. complications, although drug treatment is often necessary in people for whom lifestylechanges are not enough or not effective(2). subsequently, beta blockers, calcium channel blockers, angiotensin converting enzyme (ace) inhibitors, angiotensin receptor blockers and hmg-coa reductase inhibitors (statins) were developed as antihypertensive agents.(3) statins are hydoxy-3 methyl-glutaryl-coa (hmg-coa) redctase competitive inhibitors are commonly used in management of cardiovascular diseases in presences or absence the risk factor that related to abnormal lipid profile. there is no doubt that there is a link between bad oral health and cardiovascular diseases particularly coronary artery disease(4). statins have been found to prevent cardiovasculardisease in those who are at high risk: researchers found that statins are most effective for treating cardiovasculardisease (cvd) as a secondary prevention strategy (treatment in the early stages of a disease), however, benefitin those with elevated cholesterol levels but without previous cvd is questionable(5). it was shown that patients on statin medication exhibited reduced periodontal injury as compared to subjects without the drugs(6). statin medication may have some beneficial effects when subjects j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 86 have dental plaque or signs of periodontitis as gingival bleeding(4). furthermore, it is previously reported that statins have an effect on the salivary flow, they reduced the unstimulated salivary flow(7). matereals and methods the present study conducted in department of oral diagnosis, college of dentistry, the university of baghdad, iraq from november 2013 till may 2014. approved by the scientific committee in the institution and a consent form was obtained from each participant who enrolled in the study. the patients were recruited from the general medicine clinic in the primary health centre at al-shirqat district area in sallahalden governorate, and general medicine private clinics. the eligible patients are both gender of age (50-60) years old, presented with hypertension and they were under treatment with antihypertensive agents and/or with statins. the antihypertensive medications that used by patients are: atenolol, captopril, diltiazem, bisoprolol, losartan, aspirin, aldomet, diovan, lisnopril. the statins that used by patients are: atorvastatin, simvastatin, fluvastatin, rosuvastatin. the criteria of exclusion included; pregnancy and lactated mothers, chronic liver disease. diabetes mellitus, renal failure, recent infections and patients on the antisteroidal antiinflammatory drugs (within two weeks before enrolled in the study).a total number of ninety patients are in rolled in the present study. they are grouped into: group i (n=30): control group, healthy subjects; group ii (n=30): hypertensive patients without taking statins; group iii (n=30): hypertensive patients with statinsa demographic, medical and oral hygiene data are obtained from each patient. the demographic characteristic of patients included: gender, age, medical history, oral health, and history of the disease, current drug intake, duration of intake, status of intake (regular or irregular). then the patients were examined thoroughly taking in consideration the variables that involved in the current research. blood pressure measurement: arterial pressure is most commonly measured via a sphygmomanometer. systolic pressure is peak pressure in the arteries, which occurs near the end of the cardiac cycle when the ventricles are contracting. diastolic pressure is minimum pressure in the arteries, which occurs near the beginning of the cardiac cycle when the ventricles are filled with blood (8). oral examination: all the patients have been examined orally under standardized conditions. the oral cavity has been examined by artificial light & using a mouth mirror. the examination would begin with the lips, upper and lower sulcus, retro-molar area, upper and lower labial mucosa, buccalmucosa, hard and soft palate, dorsal margin and inferior surface of the tongue, floor of the mouth were also examined. the following are the applied oral assessments: gingival index (gi): the gi was proposed by loe and silness (9). the gi is based on two of the characteristic signs of inflammation-swelling (edema) and redness. an important sign is bleeding, it was used to assess the severity of gingivitis. a blunt instrument, such as a periodontal pocket probe, was used to assess the bleeding potential of the tissues. the score of the area around each tooth is calculated, and then the total score of all teeth was divided by the number of teeth. the severity of gingivitis is interpreted as follows: mild gingivitis = 0.1-1.0; moderate gingivitis = 1.1 2.0; severe gingivitis = 2.1 3.0 calculation: g.i. = total scores/ no. of surfaces examined decayed-missing-filled index (dmf): this index was introduced by klein, palmer and knutson in 1938 and modified by who(10). the components are: d component used to describe (decayed teeth), m component used to describe (missing teeth due to caries), f component used to describe (filled teeth due to caries). mean dmf = total dmf / total no. of the subjects examined caries restoration percentage = f / f+d * 100% collection of saliva: unstimulated (resting) whole saliva was collected, under resting conditions. patients were asked to avoid any oral hygienic procedure and rinse their mouth with water and to generate saliva in their mouth and to spit into a wide test tube(11). the collection period was ten minutes. sfr (ml/min) = saliva sample volume (ml) / collection time (min). the salivary ph was determined by using portable ph-meter (senso direct, germany). the probe of ph meter was immersed in a total volume up to 2 ml salvia and the record of ph was up to the 2 division at the temperature of saliva. descriptive inference analysis of the data achieved by application the excel 2007 and spss version 17 programs. the data are expressed as number, percent, and whenever possible as mean ± sd and median. inference j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 87 analysis was done by application un-paired two tailed student's ttest taking the probability (p) ≤ 0.05 as the lowest limit of significance. results characteristics and medical measurements: table 1 shows the characteristic of the subjects and patients enrolled in the present study. the distribution of patients in group ii shows a low number of male gender in comparison with groups i and iii. there are no significant differences between means of age of the different groups. the habit of smoking is reported in a nonsignificant low frequency in group ii. patients of group iii have a significant short duration of disease compared with group ii (2.5±1.2 years versus 7.5±4.4 years, p < 0.001 respectively. higher number of group iii patients is treated with monotherapy antihypertensive medication compared with group ii (27 versus19 patients out of each 30 patients respectively). table 2 shows the measurements of the blood pressure. systolic, diastolic and mean blood pressures are significantly higher in groups ii and iii compared with group i despite of the antihypertensive drugs that used by patients of group ii and iii. pulse pressure, a measurement of the difference between systolic and diastolic, is significantly higher in group iii compared with group i and ii. oral health indices: table 3 shows that the salivary flow rate is reduced in group ii and iii patients compared with group i. significant low salivary flow rate observed in group iii patients (hypertensive treated with statins) compared with group ii (hypertensive untreated with statins) and group i (healthy subjects). the salivary ph value is nonsignificantly increased in group ii compared with group i while it decreased in group iii compared with group i or group ii. the median value of gingival index is significantly higher in group ii (1.136) compared with corresponding value in group i (1.00) while it attended a significant low value (0.419) in group iii patients. there is no significant difference in dmf score between group i (8.303±4.91) and group iii (10.1±4.9) while a significant high score observed in group ii (12.3±7.2) compared with group i. the percent of carries restoration in patients of group ii is significantly low (28.5±36.1) compared with corresponding value of group i (50.8±39.7). although the percent of carries restoration in patients of group iii (36.1±35.7) is less than corresponding value of group i but it does not reach significant level. table (1): characteristics of the study. group i (healthy subjects) (n=30) group ii (hypertensive patients) (n=30) group iii (hypertensive patients treated with statins) (n=30) gender (male: female) 16:14 8:22 17:13 age (year) 54.9±3.1(55) 55.39±3.4(55) 56.2±3.32(57) smoking 8 5 8 alcohol intake 3 2 2 duration of hypertension (year) 7.5±4.4(7.0) 2.5±1.2(2.2)† antihypertensive medication (no.) one two 19 11 27 3 the results are expressed as number, mean ± sd (median), †p< 0.001 compared with group ii table (2): blood pressure measurements. blood pressure (mmhg) group i (healthy subjects) (n=30) group ii (hypertensive patients) (n=30) group iii (hypertensive patients treated with statins) (n=30) systolic 125.9±8.5(87.3) 143.8±13.9(140)* 148.4±15.5(145)* diastolic 84.0±8.0(83) 103.2±11.9(100)* 101.0±9.1(100)* pulse 42.2±7.9(42.5) 40.7±11.9(40) 47.4±11.3(46.5)**† mean 97.7±7.3(96.7) 116.7±11.3(116.7)* 116.8±10.4(115)* the results are expressed as mean ± sd (median), *p< 0.001, **p< 0.05compared with group i; †p< 0.05 compared with group ii j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 88 table (3): assessment of oral health. oral indices group i (healthy subjects) (n=30) group ii (hypertensive patients) (n=30) group iii (hypertensive patients treated with statins) (n=30) saliva flow rate (ml/min) 0.3660±0.1034(0.37) 0.325±0.0984(0.32) 0.2747±0.0926(0.27)***†† saliva ph 6.650±0.214(6.635) 6.790±0.368(6.825) 6.450±0.429(6.38)*† gingival index 0.817±0.530(1.00) 1.161±0.601(1.136)* 0.537±0.418(0.419)*† dmf score 8.303±4.91(7.0) 12.3±7.2(11)** 10.1±4.9(9.5) carries restoration (%) 50.8±39.7(43.8) 28.5±36.1(0)* 36.1±35.7(38.8) the results are expressed as mean ± sd (median), *p< 0.05, **p< 0.01, ***p< 0.001 compared with group i, †p< 0.001, ††p< 0.05 compared with group ii discussion the results of the present study clearly identified that statins therapy exerts a beneficial effect on the oral cavity by altering the physiochemical property of the saliva, improving the gingival index, dmf score and carries restoration. therefore, the results of this study can explain by the following points: 1. the characteristics of the study showed that there is no doubt that age factor played a role in the determination the status of the saliva. the mean age of each studied group in current study is comparable and there is no significant differences were observed. this pointed that there is no bias in the results regarding the age factor. the duration of hypertension is more in non-statins group compared with statins treated group which may influence the obtained results. hypertension itself induced changes in saliva despite the clinical presentation and whatever the medications that used(12). therefore, the variation in the duration of hypertension does not impact adversely the results of this study. 2. blood pressure levels of the present study showed the significant difference between group ii and iii in the level of pulse pressure. this observation attributed to the variation in the nature of antihypertensives that used by the patients(13). 3. there is no evidence that lipid lowering agents reduced the ph of saliva. moreover, the low ph of the saliva in our patients indicating that those patients are not under stress as the increase saliva ph is a marker of stress(14). oral health indices: the salivary flow rate is reduced in patients treated with statins. this observation is not agreed the results that showed neither antihypertensive agents nor hypertension as a disease could influence the flow rate or ph of the saliva(12). it is necessary to mention here that beta-blockers or centrally acting hypertensive's e.g. alphamethyldopa that caused dry mouth i.e. decrease blood flow(15). improvement in the gingival index indicated the favorable effect of statins on the gingiva. this observation is in agreement with other studies that showed statins is useful in chronic periodonitis(16). the favorable effects of statins on the oral health could be related to the pleiotropic effects that included: a. immunomodulatory, antioxidant, antithrombotic and endothelium stabilization actions(17). b. promote angiogenesis and increase osteoblastic differentiation(18). references 1. chobanian av, bakris gl, black hr, cushman wc, green la, izzo jr. jl, jones dw, materson bj, oparil s, wright jr. jt, roccella ej. seventh report of the joint national committee on prevention, detection, evaluation, and treatment of high blood pressure. hypertension 2003; 42(6): 1206–52. 2. carretero oa, oparil s, et al. essential hypertension.part i: definition and etiology. circulation 2000; 101 (3): 329–35. 3. chockalingam a. impact of world hypertension day. canadian j cardiol 2007; 23(7): 517–9. (ivsl) 4. saxlin t, suominen-taipale l, knuuttila m, alha p, yl¨ostalo p. dual effect of statin medication on the periodontium. j clinical periodontol 2009; 36(12): 997–1003. 5. taylor f, ward k, moore th et al. statins for the primary prevention of cardiovascular disease. in taylor, fiona. cochrane database syst rev 2011; 1: cd004816. (ivsl) 6. lindy o, suomalainen k, makela m, lindy s. statin use is associated with fewer periodontal lesions: a retrospective study. bmc oral health 2008; 8:16 (ivsl) 7. smidt d, torpet la, nauntofte b, heegaard km, pedersen aml. associations between labial and whole salivary flow rates, systemic diseases and medications in a sample of older people. community dent oral epidemiol 2010; 38: 422–35. j bagh college dentistry vol. 27(4), december 2015 an assessment of oral diagnosis 89 8. booth j. a short history of blood pressure measurement. proceedings of the royal society of medicine 1977; 70 (11): 793–9. 9. loe h, silness j. periodontal disease in pregnancy. i. prevalence and severity. acta odontol scand 1963; 21: 533-51. 10. klein h, palmer ce, knutson jw. studies on dental caries: dental status and dental needs of elementary school children. public health reporter 1938; 53: 75165. 11. navazesh m. methods for collecting saliva. ann n y acad sci1993; 694: 72-7. 12. kagawa r, ikebe k, enoki k, murai s, okada t, matsuda k, maeda y. influence of hypertension on ph of saliva in older adults. oral dis 2013; 19(5): 525-9. 13. skoglund ph, svensson p, asp j, dahlöf b, kjeldsen se, jamerson ka, weber ma, jia y, zappe dh, östergren j. amlodipine + benazepril is superior to hydrochlorothiazide + benazepril irrespective of baseline pulse pressure: subanalysis of the accomplish trial. j clin hypertension 2015; 17: 141-6. 14. cohen m, khalaila r. saliva ph as a biomarker of exam stress and a predictor of exam performance. j psychosom res 2014; 77(5): 420-5. 15. nederfors t, dahlöf c, twetman s. effects of the beta-adrenoceptorantagonists atenolol and propranolol on human unstimulated whole saliva flow rate and protein composition. j dent res 1994; 102(4): 235-7. 16. karanxha l, park sj, son wj, nör je, min ks. combined effects of simvastatin and enamel matrix derivative on odontoblastic differentiation of human dental pulp cells. j endod 2013; 39(1):76-82. (ivsl) 17. landmesser u, bahlmann f, mueller m, spiekermann s, kirchhoff n, schulz s, et al. simvastatin versus ezetimibe: pleiotropic and lipid lowering effects on endothelial function in humans. circulation 2005; 111: 2356–63. 18. maeda t, matsunuma a, kurahashi i, yanagawa t, yoshida h, horiuchi n. induction of osteoblast differentiation indices by statins in mc3t3-e1 cells. j cell biochem 2004; 92: 458–71. dropbox 4 dilyar f 19-24.pdf simplify your life dropbox 05 fatima 23-27.pdf simplify your life j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 17 caries risk assessment of a sample of children attending preventive specialized dental center in al resafa, baghdad zaid naji muhson (1), shaymaa thabit (1), fatima saeed jafar alward (1), sahar ae al shatari (2) https://doi.org/10.26477/jbcd.v32i4.2914 abstract background: young children’s oral health maintenance and outcomes are influenced by their parent’s knowledge and beliefs, which affect oral hygiene and healthy eating habits. this study aims at assessing caries risk in children aged 6 months to 6 years attending the specialized center of preventive and pediatric dentistry center at al-resafa sector in baghdad. materials and methods: a cross-sectional study was conducted from 15 may – 15 june 2018, all children attended the center (80 children) were assessed by using the standard caries risk assessment tool of the american academy of pediatric dentistry (aapd). results: the highest percentage of children was as follows: no fluoride exposure 44(55%), did not brush 46(57.5%), had no special health care needs 77(96.25%), had no missed teeth due to caries 51(63.75%), had no-visible plaque 52(65%), frequent or prolonged between-meal exposure/day 55(68.75%), their mothers had carious lesions in last 7-23 months 34(42.5%); in visual caries: had carious lesions or restorations in last 24 months 67(83.75%), while the incipient carious lesions in last 24 months were 50(62.50%). most of risk assessment score for the participants was moderate 57(71.3%), followed by low risk 16(20%), while the participants with high risk were 7(8.8%), with a statistically significant association between the risk assessment score and fluoride exposure (p=0.043), sugary foods or drinks(p=0.038), caries experience of the mothers (p=0.001), brushing (p=0.020) visual caries (p=0.000), incipient caries (p= 0.000), missing teeth due to caries (p= 0.001), but no statistical significance with special health care needs (p=0.533) and visible plaque (p=0.259). conclusion: moderate-risk of developing dental caries was predominant among the participants, followed by low-risk and less high-risk categories. keywords: caries risk assessment, pediatric caries, and oral health maintenance. (received: 24/09/2020; accepted: 22/11/2020). introduction globally, tooth decay is a significant public health issue and seems to be the most common noncommunicable disease ncd.(1) caries can result from three dynamically interrelated main factors: bacteria in the dental plaque, the host, and carbohydrates. (2) it is the chronic condition most prevalent amongst children and young adults, (3) and therefore the most frequently negatively affecting both oral and general health.(4,5) although tooth decay is greatly preventable, it continues to be the main childhood chronic disease in children aged 6 to 11 years and adolescents aged 12 to 19 years. among teenagers aged 14 to 17 years, dental caries is four times greater than asthma. (6) microbiological changes within the dental biofilm disrupt the remineralization /demineralization process of the tooth enamel; such equilibrium is also influenced by the flow 1. dentist, work address: specialized center of preventive and pediatric dentistry in al resafa, baghdad-iraq 2. consultant family physician in training phc centre for family health approach at bab al-moadham, baghdad. corresponding author: saharissa2020@gmail.com and composition of saliva, fluoride exposure, refined sugar intake, and preventive habits (for example teeth brushing). (7) the oral health care of young children, as well as the consequences, was affected by the knowledge and beliefs of their parents that affect healthy eating habits and oral hygiene.(8) whether tooth decay progression is stopped, reversed, this depends on the balance involving protective and pathogenic factors.(9) caries risk assessment (cra) is a key element of preventing dental caries and it should be viewed as a standard of care and used as part of the dental inspection. this is also important in decisionmaking so that the clinician be directed in the patient diagnosis, prognosis, and caries management guidance. (10) it is common to assess the relative risk of developing caries in the patient. risk assessment is necessary to avoid any disease and it directs practitioners to implement suitable preventive measures. there are different approaches for risk assessment of caries. cat (caries risk assessment tool) was introduced by the american academy of pediatric dentistry (aapd).the assessment of the risk is based on the individual's clinical situation, environmental conditions, and overall health. on this basis, each child may be https://doi.org/10.26477/jbcd.v32i4.2914 j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 18 classified as having a low, moderate or high risk of developing caries.(11) the american dental association has developed a technique that identifies low, moderate or high risk for six months to six year old patients. (12) the purpose of the caries risk assessment is to anticipate whether the disease is likely to develop in an as-yet-caries-free person or to assess the degree of progression of the disease in an individual who has some experience with caries already. describing caries risk status to each patient is fundamental to treatment planning as it prompts the clinician to propose the most appropriate preventive strategy. the concept of risk assessment of caries for each child is to ensure that diagnostic tests selected, preventive and any restorative therapy are planned primarily for the needs of that particular individual.(13) objective: to assess the caries risk of 6-months to 6-year-old children attended to the specialized center of preventive and pediatric dentistry in al-resafa baghdad/ iraq. moreover, to evaluate the association between the caries risk groups with different indicators. materials and methods a cross-sectional study was conducted in specialized dental center in al-resafa from 15 may – 15 june 2018, all children attended the center (80 children) were assessed by using the standard caries risk assessment tool of the american academy of pediatric dentistry (aapd), which assesses the risk based on the clinical condition of the individual, environmental factors, and general health. children were examined for the followings: professional fluoride exposure and fluoridated dental brushing, presence of new incipient or cavitated caries, missing teeth due to caries or restoration in the last 24 months, presence of appliance in the mouth, and special healthcare need patients. standard caries risk assessment tool it categorizes the children into 3 categories (low, moderate, and high) risk to develop caries in the future. the tool consists of one form questionnaire (figure 1) for the child (6months-6 years) answered by the parent interview and the child himself according to the tool (conducted by same author). questionnaire it consists of contributed conditions (preventive and risk factors), general health conditions, and visualized clinical examination. the children were examined in dental clinics, the visual examination was performed in the dental chair using an operating light, a dental mirror, and teeth were dried with a triple syringe before the examination. the caries risk indicators are the variables that are thought to cause the disease directly (e.g., dental plaque) or have been shown useful in predicting it (e.g., frequent sugar consumption, primarily at mealtimes, frequently between-meals or by the bottle at bedtime). the presence of new incipient or cavitated caries, missing teeth due to caries, or restoration in the last 24 months may also give indications of caries risk activity. while the protective factors in caries risk include children receiving topical fluoride from a health professional, and having teeth brushed daily with fluoridated toothpaste. the visual clinical examination also included the caries experience of the mother, if there were any caries lesions in the last (6-24) months. included criteria: the fluoride exposure depended in the study was the professional application only. the question about the regular brushing was added to the list, instead of the question: established record of patient receiving regular dental care in a dental clinic, due to the unavailability of established records. all children aged up to 6 years attended the specialized dental center in al-resafa, and their parents accepted to get involved in the study during the data collection duration 15 may – 15 june 2018. excluded criteria: the question: eligible for government programs was excluded due to the lack of government programs in iraq at that time. statistical analyses: data entry and statistical analysis were conducted by using spss version 23. frequencies and percentages, chi-square, and p-values were calculated and considered significant if less than 0.05. j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 19 figure 1: caries risk assessment form. low risk: only conditions in the “low-risk” column present; moderate risk: only conditions in “low” and/or “moderate risk” columns present; high risk: one or more conditions in the “high risk” column. results eighty children were enrolled in this study. from the history taking and by the clinical examination, the study revealed: no fluoride exposure 44(55%), did not brush 46(57.50%), had no special healthcare needs 77(96.25%), had no missed teeth due to caries 51(63.75%), had no visible plaque 52(65%), frequent or prolonged between-meal exposure/day 55(68.75%), their mothers had carious lesions in last 7-23 months 34(42.50%). in cases with visual caries: had carious lesions or restorations in last 24 months 67(83.75%), while the incipient carious lesions in last 24 months were 50(62.50%) this was done (table 1). most of risk assessment score for the participants was moderate57(71.3%), followed by low risk 16(20%), while the participants with high risk were 7(8.8%), as shown in table (2) and figure (2). table (3) shows the statistical significant associations between the risk assessment score and fluoride exposure (p=0.043), sugary foods or drinks (p=0.038), caries experience of mother (p=0.001), brushing (p=0.020), visual caries (p=0.000), incipient caries (p=0.000), missing teeth due to caries (p=0.001), while non-significant relations with special health care needs (p=0.533) and visible plaque (p=0.259). discussion caries risk assessment is known as a central element of caries prevention for children in clinical settings (14, 15). risk assessment includes identifying clinical and non-clinical indicators related to forthcoming caries development, within a broader caries management plan encircling individualized, prevention-focused, and minimally invasive care.(14) the present study was performed to obtain information about caries risk in a group of children aged (6 months to 6 years) attending the specialized center of preventive and pediatric dentistry in al-resafa, baghdad as well as to evaluate the relation between the risk assessment score with different indicators. studies on risk markers for caries in preschool youngsters have focused on child oral health habits related to caries development in children, and child-level impacts. noticeable plaque (16, 17), early colonization via caries-related microbes (18), the presence of mutans streptococci (19-22), frequent exposure of sweetened beverages (17, 23, 24), inconsistent tooth brushing (25) have all been related to caries advancement in preschool children. children with dental tension and behavior management issues are accounted for having more carious surfaces and more missed dental appointments than other children,(26-29) and missing dental appointments has been related to dental caries in youngsters.(30) the present study showed that most of the participants were in moderate-risk of developing dental caries followed by low-risk and finally highrisk. the study demonstrated that most children were not exposed to the fluoride application, regular teeth brushing, and not having special health care needs. moreover, less number of children in the study had missing teeth due to caries and visible plaque but frequent exposure to dietary sugar and refined carbohydrates. chaffee et al. found that the risk group was strongly connected with follow up caries, which expanded from low, moderate to high/extreme risk patients.(31) the higher number of mothers in this study and their children had new carious lesions, incipient carious lesions, and restorations in the last two years. there were significant relations between the caries risk score and the caries j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 20 experience of mother, caries risk score, and the visual and incipient caries of the children which were mostly concentrated in the moderate-risk group. this is due to the lack of parental awareness as most mothers thought that dental visits are important only in case of dental pain in our community; besides frequent exposing to sugary snacks, drinks, refined carbohydrate, inappropriate bottle feeding, lack of periodic dental recalls and care, no community water fluoridation and tooth brushing wrong technique or inappropriate use of fluoridated toothpaste. weintraub et al. (2010) found that mothers with untreated dental caries significantly increased caries severity in children by 3 surfaces and nearly twice the chance for having untreated dental caries.(32) al-zahrani et al. (2014) concluded that the education of mothers in several aspects and areas was needed especially regarding diet, first dental appointment, and feeding. (33) this study showed that there was a significant relation between caries risk assessment and exposure to the fluoride as less than half of the total sample had fluoride mainly by professional fluoride application topically who were at moderate-risk of developing dental caries compared to those not exposed to fluoride application. this was because of not having fluoridated communal or school water fluoridation in our country, moreover the lack of parental knowledge for the importance and the role of the fluoride in caries prevention. this comes in agreement with twetman et al. who found that the caries predictive ability decreased with increasing fluoride exposure in 4-5 years old children. (34) the study demonstrated that there was a significant relationship between having snacks and/or sugary drinks frequently or prolonged between-meal per day with the caries risk assessment score and was found mostly in the moderate-risk group. this was due to the lack of parental knowledge and guidance and exposing their children to snacks like sweets, chips (potatoes), etc. frequently at different times of the day with poor oral hygiene habits like no or inappropriate brushing. burt et al. concluded that children grouped with high caries risk had more sweets intake compared to children in the low-risk group.(35) moynihan et al.(2005) found that the association between the numbers of caries was counted as the addition of dfs and dmfs indices and intake of cariogenic food in a group of six months to 10-year-old children, which are mostly at low-risk of caries.(36) a significant relation of brushing and insignificant relation of visible plaque with caries risk score were found in the current study. this was reasoned to the parents’ ignorance of the correct way and patterns of teeth brushing or no brushing as more than half of the total sample answered, which would be conveyed to their children as parents would be the role models to their children. besides the lack of oral health education programs and mass media oral health promotion messages regarding the importance of starting teeth brushing from the tooth eruption time, the right techniques to brushing, the definition of dental plaque to the parents and children as it is considered a causative factor of dental decay and control of plaque is a major part in caries prevention and the use of toothpaste containing fluoride. harrera et al. found that there were relationships between dental caries of deciduous teeth and dental plaque, brushing teeth, and having access to preventive dental service and also found that the visible dental plaque increased the caries index value and that consistent and regular tooth brushing decreased it.(37) less number of participants in the study had missing teeth due to caries, but there was a significant relationship between the caries risk score and teeth extracted due to dental caries. most parents in our community need to be educated about the stages of dental caries and the consequences after losing teeth due to dental lesions progression whether for deciduous or permanent teeth, explaining to them the dental plaque and its role and the importance of good oral hygiene as a routine on daily basis. in this study, an indicator of special health care needs was excluded for not having eligible programs in iraq and no established patient records of receiving regular dental care; for this was replaced by regularly brushing. there were a higher number of participants who were irregularly brushing their teeth but no significant relationship between this indicator and caries risk scores was found. this was because of the lack of oral health education to know the right way, frequency, and the importance of teeth brushing as most people in our community either irregularly brushing or do no brushing. pita-fernandez et al. (2010) found that the dental caries prevalence is less by 62% in children who brush their teeth more frequently j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 21 during the day as compared to those who do not brush their teeth at all. (39) conclusion caries risk assessment is an important tool to target the risk group, to figure out the risk factors, and to implement the proper treatment plans and programs in dental caries prevention. most children had bad dental habits with moderate-low caries risk scores in this study. the children's oral health is affected by their mothers’ oral health habits and knowledge. there is a need to implement more programs for oral health education and promotion for parents on community-level regarding brushing, dietary control, fluoride, periodic recalls for the dentist, the plaque control, and tooth loss due to caries consequences. recommendations: 1. using the same methodology, the same study can be done with covering other regions of the country with specialized centers, schools, kindergartens, and adults with a larger sample size. 2. to perform a study about the relation between the caries risk score and the counts of mutans streptococci, lactobacilli, and salivary flow rate. 3. a study to compare with other methods of caries risk assessment tools. 4. conducting a study to measure the caries risk score in children with various special needs. conflict of interest: none. references 1. world health organization (who) (2017). sugars and dental caries. who department of nutrition for health and development. 2. rathee m, sapra a. dental caries. [updated 2020 jun 3]. in: statpearls [internet]. treasure island (fl):statpearls publishing; 2020. 3. filstrup sl, briskie d, da fonseca m, lawrence l, wandera a, inglehart mr. early childhood caries and quality of life: child and parent perspectives. pediatr dent. 2003;25: 431–440. 4. edelstein bl. disparities in oral health and access to care: findings of national surveys. ambul pediatr. 2002;2:141–147. 5. petersen pe. the world oral health report 2003: continuous improvement of oral health in the 21st century–the approach of the who global oral health programme. comm. dent oral epidemiol. 2003;31:3–23. 6. dye ba, tan s, smith v, lewis bg, barker lk, thornton-evans g, eke pi, beltrán-aguilar ed, horowitz am, li ch. trends in oral health status, united states, 1988-1994, and 1999-2004.external vital health stat 11. 2007;(248):1-92. 7. selwitz rh, ismail ai, pitts nb. dental caries. lancet 2007, 369(9555): 51-9. 8. kamolmatyakul s, saiong s.oral health knowledge, attitude, and practices of parents attending prince of songkla university dental hospital. interj health promot educ. 2007; (45):111‑3. 9. featherstone jd. caries prevention and reversal based on the caries balance. pediatr dent. 2006, 28(2): 12832. 10. anusavice k. clinical decision-making for coronal caries management in the permanent dentition. j dent educ. 2001; 65(10):1143-1146. 11. american academy of pediatric dentistry, council on clinical affairs. policy on the use of a caries risk assessment tool (cat) for infants, children, and adolescents pediatr dent. 2002; 25:18. 12. hurlbutt m. cambra: best practices in dental caries management. penn well designates this activity for 3 continuing educational credits, october 2011. 13. hunter m, rodd h. history, examination, risk assessment, and treatment planning: pediatric dentistry, 4th edition, oxford university press, 2012. 14. fontana m. the clinical, environmental, and behavioral factors that foster early childhood caries: evidence for caries risk assessment. pediatr dent. 2015; 37(3):217–25. 15. okunseri c, gonzalez c, hodgson b. children’s oral health assessment, prevention, and treatment. pediatr clin north am. 2015; 62(5):1215–26. 16. wendt lk, hallonsten al, koch g, birkhed d. oral hygiene in relation to caries development and immigrant status in infants and toddlers. scand j dent res. 1994; 102:269-73. 17. declerck d, leroy r, martens l, lesaffre e, garciazattera mj, vanden bs, et al. factors associated with prevalence and severity of caries experience in preschool children. comm dent oral epidemiol. 2008; 36:168-78. 18. alaluusua s, malmivirta r. early plaque accumulation a sign for caries risk in young children. comm dent oral epidemiol. 1994; 22:1-6. 19. grindefjord m, dahllöf g, nilsson b, modéer t. prediction of dental caries development in 1year-old children. caries res. 1995; 29:343-8. 20. grindefjord m, dahllöf g, nilsson b, modéer t. stepwise prediction of dental caries in children up to 3.5 years of age. caries res. 1996; 30:256-66. 21. pienihakkinen k, jokela j, alanen p. assessment of caries risk in preschool children. caries res. 2004; 38:156-62. 22. warren jj, weber-gasparoni k, marshall ta, drake dr, dehkordi-vakil f, kolker jl, et al. factors associated with dental caries experience in 1-year-old children. j public health dent. 2008; 68:70-5. 23. karjalainen s, soderling e, sewon l, lapinleimu h, simell o, a prospective study on sucrose consumption, visible plaque and caries in children from 3 to 6 years of age. comm dent oral epidemiol. 2001; 29:136-42. j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 22 24. rodrigues cs, sheiham a. the relationships between dietary guidelines, sugar intake, and caries in primary teeth in low-income brazilian 3-year-olds: a longitudinal study. inter j paediatr dent. 2000; 10:4755. 25. peres ma, latorre mrdo, sheiham a, peres kg, barros fc, hernandez pg, et al. social and biological early life influences on the severity of dental caries in children aged 6 years. comm dent oral epidemiol. 2005; 33:53-63. 26. klingberg g, berggren u, carlsson sg, norén jg. child dental fear: cause-related factors and clinical effects. eur j oral sci. 1995; 103:405-12. 27. milsom km, tickle m, humphris gm, blinkhorn as, the relationship between anxiety and dental treatment experience in 5-year-old children. br dent j. 2003; 194:503-6. 28. wogelius p, poulsen s. associations between dental anxiety, dental treatment due to toothache, and missed dental appointments among six to eight-year-old danish children: a cross-sectional study. actaodontolscand. 2005; 63:179-82. 29. klingberg g, vannas ll, bjarnason s, norén jg. dental behavior management problems in swedish children. comm dent oral epidemiol. 1994; 22:2015. 30. wang nj, aspelund gø. children who break dental appointments. eur arch paediatr dent. 2009; 10:11-4. 31. chaffee bw, featherstone jdb, gansky sa, jing cheng, ling zhan, caries risk assessment item importance: risk designation and caries status in children under age 6. jdr clin trans res. 2016;1(2):131-142. 32. weintraub ja, prakash p, shain sg, laccabue m, gansky sa. mothers’ caries increases odds of children’s caries j dent res. 2010; 89(9): 954–958. 33. al-zahrani am, al-mushayt as, otaibi mf, wyne ah, knowledge and attitude of saudi mothers towards their preschool children’s oral health. pak j med sci. 2014;30(4):720–724. 34. twetman s, petersson lg. prediction of caries in pre‐ school children in relation to fluoride exposure. eur j oral sci. 1996;104:523-528. 35. burt ba, eklund sa, morgan kj, larkin fe, guire ke, brown lo, weintraub ja, the effects of sugars intake and frequency of ingestion on dental caries increment in a three-year longitudinal study. j dent res. 1988; 67(11):1422–1429. 36. moynihan pj, the role of diet and nutrition in the etiology and prevention of oral diseases. bull world health organ. 2005;83(9):694–699. 37. herrera ms, medina-solis ce, minaya-sánchez m, pontigo-loyola, rodelo jf, granillo hi, santillana rr, maupomé g. dental plaque, preventive care, and tooth brushing associated with dental caries in primary teeth in schoolchildren aged 6–9 years of leon, nicaragua. med sci monit. 2013;19:1019–1026. 38. eigbobo jo, gbujie dc, onyeaso co. causes and pattern of tooth extractions in children treated at the university of port harcourt teaching hospital. odontostomatol trop. 2014;37(146):35-41. 39. pita-fernández s , pombo-sánchez a, suárezquintanilla j, novio-mallón s, rivas-mundiña b, pértega-díaz s. clinical relevance of tooth brushing in relation to dental caries. aten primaria. 2010;42(7):372-9 table (1): distribution of the participants according to risk criteria: freq. percent fluoride exposure yes 36 45.00% no 44 55.00% brushing yes 34 42.50% no 46 57.50% special health care needs yes 3 3.75% no 77 96.25% missing teeth due to caries yes 29 36.25% no 51 63.75% visible plaque yes 28 35.00% no 52 65.00% sugary foods or drinks primarily at mealtimes 17 21.25% frequent or prolonged between-meal exposure/d 55 68.75% bottle/sippy cup with other than water at bedtime 8 1.00% caries experience of mother no carious lesions in the last 24 months 20 25.00% carious lesions in the last 7-23 months 34 42.50% carious lesions in the last 6 months 26 32.50% visual caries no new carious lesions/restorations in the last 24 ms 13 16.25% carious lesions/restorations in the last 24 ms 67 83.75% incipient caries no new carious lesions in the last 24 months 30 37.50% carious lesions in the last 24 months 50 62.50% total 80 100.0% j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 23 table (2): distribution of the participants according to their risk assessment score. frequency percent risk assessment score low 16 20.0 moderate 57 71.3 high 7 8.8 total 80 100.0 figure 2: distribution of the participants according to their risk assessment score. table (3): association between the risk assessment score and various criteria. risk assessment score total pvalue low moderate high fluoride exposure yes 8 28 0 36 0.043 no 8 29 7 44 sugary foods or drinks primarily at mealtimes 7 10 0 17 0.038 frequent or prolonged between-meal exposure\ day 9 41 5 55 bottle or sippy cup with anything other than water at bedtime 0 6 2 8 caries experience of mother no carious lesions in the last 24 months 10 9 1 20 0.001 carious lesions in the last 7-23 months 6 25 3 34 carious lesions in the last 6 months 0 23 3 26 brushing yes 10 24 0 34 0.020 no 6 33 7 46 special health care needs no 16 54 7 77 0.533 yes 0 3 0 3 visual caries no new carious lesions or restorations in last 24m 9 4 0 13 0.000 carious lesions or restorations in the last 24 m 7 53 7 67 incipient caries no new carious lesions in the last 24 months 15 14 1 30 0.000 carious lesions in the last 24 months 1 43 6 50 missing teeth due to caries no 11 40 0 51 0.001 yes 5 17 7 29 visible plaque no 13 34 5 52 0.259 yes 3 23 2 28 total 16 57 7 80 j bagh college dentistry vol. 32(4), december 2020 caries risk assessment 24 : الخالصة تتأثرعملياتالحفاظ على صحة الفم لدى األطفال و نتائجها بالمعرفة و المعتقدات لدى االبوين، والتي تؤثرعلى صحة ونظافة الفم مقدمة: .وعادات األكل الصحية ايضا. سنوات في المركز التخصصي لطب األسنان 6أشهر و 6األهداف: لتقييم مخاطر التسوس لدى األطفال الذين تتراوح أعمارهم بين .الوقائي و طب أسنان األطفال في الرصافة، بغداد 80، وتم اخذ عينة 2018 15/6 15/5الطريقة: دراسة مقطعية أجريت في مركز طب األسنان التخصصي في الرصافة للفترة من ألطفال طفالً و تم تقييمهم باستخدام أداة تقييم مخاطر تسوس األسنان القياسية لألكاديمية األمريكية لطب أسنان ا ٪(، ال يقومون بتنظيف االسنان 55)44طفالً مسجلين في هذه الدراسة، النسبة األكبر منهم لم يتعرضوا للفلورايد 80النتائج: تم اشراك خاصة 57.50)46بالفرشاة صحية رعاية احتياجات لديهم ليس التسوس 96.25)٪77(، بسبب مفقودة أسنان لديهم ليس ،)٪ ٪(، فترة التكررأو طول الفترة بين التعرض للوجبة الغذائية 65) 52هم ترسبات مرئية للصفيحة الجرثومية ٪(، لم يكن لدي 63.75)51 ٪(، او كان لديهم آفات نخرية 42.50)34شهًرا 237٪(، نسبة األمهات مع اسنان مصابة بآفات نخرية في آخر 68.75)55في اليوم ٪(. 62.50)50شهًرا الماضية كانت 24٪( بينما اآلفات النخرية األولية في الـ 83.75)67شهًراالماضية 24مرئية أو ترميمات في الـ ٪( ،بينما كان المشاركون ذوو 20) 16٪(، تليها مخاطر منخفضة 71.3)57كانت معظم درجات تقييم المخاطر للمشاركين معتدلة ( ،أطعمة أو p=0.043المخاطر والتعرض للفلورايد ) ( ،مع وجود عالقة إحصائية ذات داللة بين درجة تقييم8.8) 7الخطورة العالية ( ،تسوس p=0.000( تسوس مرئي )=0.020p(( ،تفريش االسنان p =0.001( ،تسوس اسنان األم )p=0.038مشروبات سكرية ) لصحية ( ،ولكن ليس ذات داللة إحصائية مع احتياجات الرعاية اp=0.001( ،أسنان مفقودة بسبب تسوس األسنان )p=0.000بدائي ) )p=0.259( صفيحة جرثومية مرئية )p =0.533الخاصة ) .لدى معظم األطفال عادات سيئة في األسنان مع درجة مخاطر معتدلة إلى منخفضة االستنتاج: كان eeman.doc j bagh college dentistry vol. 27(1), march 2015 analysis of inflammatory oral diagnosis 105 analysis of inflammatory cells in osseointegration of cpti implant radiated by low level laser therapy eman i. altamemi, b.d.s., m.sc. ph.d. (1) abstract background: dental implants provide a unique treatment modality for the replacement of a lost dentition .this is accomplished by the insertion of relatively an inert material (a biomaterial) into the soft and hard tissue of the jaws, there by providing support and retention for dental prostheses. low level laser therapy (lllt) is an effective tool used to prompt bone repair and remodeling, this has referred to the biostimulation effect of lllt. the aim of this study was to evaluate the effects of inflammatory cells on osseointegration of cpti implant irradiated by low level laser. materials and methods: thirty two adult new zealand white rabbits, received titanium implants were inserted in the tibia. the right side is considered as experimental groups and the left side considered as control groups. low power diode laser (gaalas ) with wave length (904nm) and (5mw)power applicated with the right implants . the sample divided into four groups, eight rabbits were sacrificed at four interval 4days, 1 weeks, 2weeks, and 6weeks respectively. histological and inflammatory analyses were done for each interval. results: histological examination showed acceleration of bone formation and more rapid healing process in the screw implant with laser irradiation than in the control implant .inflammatory analysis showed dramatic decrease with the presence of laser irradiation especially with advancing time. conclusion: this study illustrated that the inflammatory cells were reduced in osseointegration of dental implant treated with lllt. key words: dental implants, low level laser therapy, inflammatory cell. (j bagh coll dentistry 2015; 27(1):105-110). introduction dental implants are biocompatible screw like titanium objects that are surgically placed into the mandible or maxilla to replace missing teeth. the mechanism by which an implant is biomechanically accepted by the jaw bone is called osseointegration (1,2) the clinical long-term success of the implants depends on the osseointegration and the adhesion of the soft tissues and epithelium to the titanium surfaces of the implant (3). titanium is the most wide spread metal for orthopedic implants intended for bone integration. it represents high fatigue strength comparatively low modulus of elasticity, in respect to other metals, so it is able to support loads and distribute them to bone, limiting stress shielding. besides titanium is characterized by a thin natural oxide layer on the surface that limits ion release and reactivity, making the surface almost inert and biocompatible (4). several treatments have been proposed to improve and accelerate bone formation onto implant surface, among which is low-level laser therapy (lllt) (5). lllt known as cold laser, soft laser, biostimulation, or photobiomodulation, it basically exposes cell or tissue to laser or lowlevel red or near-infrared (ir) light generated from light-emitting diode. lllt stimulates or controls cellular function to minimize the extinction of cell or tissue, accelerates the healing of fractures, fast recovery from the damage of soft (1)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. tissue, nerve, bone, and cartilage, and relieves acute and chronic pain and inflammation (6). materials and methods all experimental procedures were carried out in accordance with the ethical principles of animal's experimentation. thirty-two adult male new zealand weighing 2-3kg were used in this study. screw cpti implants were inserted in the right tibia of each animal (experimental side), and left tibia was used as (control side). low power diode laser (gaalas) with wave length (904nm) and (5mw) power applied with the right screw implants. the animals were divided into four groups, for 4days, 1weeks, 2weeks, and 6weekshealing intervals. inflammatory cells counting were done under light microscope, in eight histological sections (stained by hematoxyline and eosin stain) for each healing period and for both experimental and control groups at / magnifying power lens x40. score for intensity of inflammatory reaction per unit area (mm²): 1absent: or few (0-4) inflammatory cells. 2mild: average number less than 10 inflammatory cells. 3moderate: average number (10–25) inflammatory cells. 4severe: average number greater than 25 inflammatory cells (7). j bagh college dentistry vol. 27(1), march 2015 analysis of inflammatory oral diagnosis 106 results histological findings (hematoxylin and eosin stain) at 4 days duration control group screw that implant in the tibia of rabbit shows bone marrow with stromal cells figure (1). figure 1: high magnification view of implant site shows fat cell (fc) in marrow tissue h&e x400. experimental group histological view of implant site treated with laser irradiation after 4 days of implantation revealed primitive new bone formation in which future bone is formed as embryonic bone figure (2). high magnification view of marrow tissue illustrates the presence of fat cells associated with presence of numerous blood islets figure (3). figure 2: microphotograph view of implant rabbit tibia shows bone marrow h&ex200. figure 3: high magnification of previous figure (2) shows numerous blood in the marrow tissue (arrow) point to blood vessel h&ex400. at one week duration control group screw that implanted in the rabbit tibia shows the formation of osteoid tissue, abundant blood vessels in thread region that follows the screw shape figure (4). figure 4: microphotograph view of bone marrow in thread region in implant site (control) of one week duration shows fat cell (fc) h&ex100. experimental group the histological view of implant site in rabbit tibia treated with the laser irradiation after one week duration shows the bone trabeculae, osteoid tissue formed by active osteoblast figure (5). active bone marrow is indicated by active osteoprogenitor cell, osteoblast cell and by the formation of osteoid tissue figure (6). f c j bagh college dentistry vol. 27(1), march 2015 analysis of inflammatory oral diagnosis 107 figure 5: microphotograph view of implant in rabbit tibia treated with laser irradiation for one week duration shows osteoid tissue (ot), bone trabeculae (bt), osteocyte (oc) h&e x200. figure 6: microphotograph view of implant site treated with laser ir radiation after one week of implantation shows osteoblast cell (ob) and osteoid bone formation (ot) h&e x400. at 2 weeks duration control group the histological view of implant site illustrates the apposition of woven bone against the basal bone with many osteoblast cells, osteocyte cell and osteoclast occupying howship's lacunae figure (7). figure 7: microphotograph view of implant site after 2 weeks (control) shows formation of woven bone (wb)against basal bone (bb), active formative osteoblast cell (ob), and osteoclast cell (ocl) .h&ex200 experimental group the histological view of experimental group with areas of marrow tissue shows the formation of bone trabeculae, osteoblast cell on the surface of the bone, osteocyte cell trapped inside the bone matrix cell. figure (8, 9) figure 8: view of implant site of 2 weeks duration treated with laser irradiation showing bone trabeculae (bt) with the osteoblast (ob) and osteocyte trapped inside bone matrix (oc) h&e x400. ot ob ot oc bt ocl wb bb ob bt oc ob j bagh college dentistry vol. 27(1), march 2015 analysis of inflammatory oral diagnosis 108 figure 9: high magnification of previous figure (9) of 2 weeks duration showing osteoblast cells rimming the bone surface (ob) h&ex400. at 6 weeks duration control group screw that implanted in the rabbit tibia (control) for 6 weeks duration shows mature bone formation in the thread region figure (10). figure 10: microphotograph view of bone thread in implant site after 6weeks of implantation (control) shows mature bone (imb) with havarsian bone lamellae (hb), osteocyte cell (oc) that surronnd haversian canal(hc) h&e x200 experimental group the histological picture of this group shows mature bone formation filling the thread of cortical bone area, the newly bone appear dense with regular distribution of osteocyte cell trapped inside the bone matrix, reversal line separating between old and new bone with the presence of numerous resting lines, haversian bone lamellae are obviously seen figure (11). figure 11: other figure of mature bone in implant site for 6 weeks duration treated with laser irradiation shows osteocyte cell (oc), reversal line (rl) separated between old bone (ob) and new bone (nb) h&e x400. inflammatory cells parameter the result of the present study indicated that the majority of the inflammatory cells parameter was reported at the control group, as well as the first score and decreasing up to the last period of time after treatment in (6 weeks). there was no significant difference between mean values of the control and experimental groups at each healing period and the highest mean values were recorded at the 4 days and 1 week duration, where as after 2and 6 weeks of implantation mean values of scores were clearly less than the first two periods. in addition to that, the comparisons significant among different periods of times reported a non significant differences at p>0.05 for both control and experimental groups throughout the healing periods (4 days, 1, 2 and 6 weeks). as shown in figure (12) (table1). 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4 days 1 week 2 weeks 6 weeks con. exp. figure 12: cluster bar chart for mean values of scoring (inflammatory cells outcomes) distributed among different studied sources of variations. hb hc oc mb ob rl nb ob oc j bagh college dentistry vol. 27(1), march 2015 analysis of inflammatory oral diagnosis 109 table 1: distribution of the observed frequencies and percentages with summary statistics of the inflammatory cells outcomes according to different sources of variation with comparisons significant periods scores control exp. c.s. (*) p-value no. % ms sd no. % ms sd 4 days score-1 0 0.00 3.375 0.744 0 0.00 3.250 0.707 0.125 ns score-2 1 12.5 1 12.5 score-3 3 37.5 4 50.0 score-4 4 50.0 3 37.5 1 week score-1 0 0.00 3.125 0.835 0 0.00 2.455 1.128 0.273 ns score-2 2 25.0 2 25.0 score-3 3 37.5 4 50.0 score-4 3 37.5 2 25.0 2 weeks score-1 4 50.0 1.625 0.744 6 75.0 1.250 0.463 0.250 ns score-2 3 37.5 2 25.0 score-3 1 12.5 0 0.00 score-4 0 0.00 0 0.00 6 weeks score-1 4 50.0 1.500 0.535 7 87.5 1.125 0.354 0.375 ns score-2 4 50.0 1 12.5 score-3 0 62.5 0 0.00 score-4 0 0.00 0 0.00 c.s.(**) p-value f=14.848 s f=15.615 s (*) comparison sig. based on the kolmogorov-smirnovtest for two independent groups of an ordinal scale. ns: non sig. at p>0.05 (the critical value of k-s statistic = 0.680). (**) f – test (anova) statistics, s: sig. at p<0.05 discussion all animals tolerated the implantation well, no sign of gross infection, tissue reaction or any other negative clinical indications the histological findings showed biocompatible and osseoconductive implant surfaces in all groups, with different rates of bone deposition and remodeling. the results showed accelerated growth of bone around implant in groups who were exposed to laser and this may be attributed to the followings: 1-stimulation with lllt creates a number of environmental conditions that appear to accelerate the healing of bone in vivo investigations (8). 2lllt is an effective tool used to prompt bone repair and modeling post surgery , this has referred to the biostimulation effect of lllt, it is directly dependent on the dose applied (9,10). 3-the early bone maturation could be attributed to the stimulation of fibroblast proliferation through the application of lllt as it has been reported by (11). 4lllt-related effects include stimulation of blood flow, recruitment and activation of osteoblasts, osteosynthesis, a decrease in osteoclastic activity and anti-inflammatory action could also be considered as factors that stimulate biomaterial osseointegration. these findings were in agreement with previous findings (9,12-18). the response of the bone to the trauma through placement the implants by an inflammatory reaction played a great role in fixation of implant at early regenerative process (19). within a few hours after injury, inflammatory cells invade the wound tissue. in addition to the defense functions, inflammatory cells are also an important source of growth factors and cytokines, which initiate the proliferative phase of wound healing (20,21) . at 4 days and 1 week of healing periods there was a large number of inflammatory cells that migrated towered the site of implant while at 2,6 weeks there was marked reduction in the number of inflammatory cells that infiltrated in to the implant sites which indicates earlier acute inflammatory response and more rapid resolution resulting in earlier phase of regeneration ;which agreed with (22-24) who found that lllt was able to promote wound healing by reducing inflammation without compromising the proliferation of fibroblasts and keratinocytes. goldman, 1987(25) walsh, 2003 (26) found that lllt is supposed to reduce pain, accelerate wound healing and reduce inflammatory processes. furthermore, it enhances bone remodeling, attenuates pain and modulates the immune system. the present study suggests for beneficial use of lllt in practice of dentistry implantation or in other branch related to osseointegration process. j bagh college dentistry vol. 27(1), march 2015 analysis of inflammatory oral diagnosis 110 references 1guan h, staden rv, loo yc, johnson n, ivanovski s, meredith n. influence of bone and dental implant parameters on stress distribution in the mandible. int j oral maxillofacial imp 2009; 24: 866 76. 2oshida y, tuna eb, aktören o, and gençay k. dental implant systems. int j mol sci 2010; 11: 1580-678. 3ghahroudi aar, talaeepour ar, mesgarzadeh a, rokn ar , khorsand a, mesgarzadeh nn, kharazi fard mj .radiographic vertical bone loss evaluation around dental implants following one year of functional loading. j dentistry, tehran uni med sci 2010; 7:55-123. 4ferraris s, spriano s, pan g, venturello a, bianchi cl, chiesa r, faga mg, maina g, verne e. surface modification of ti-6al-4v alloy for biominerlization and specific biological response. part 1, inorganic modification. j mater sci mater med 2011; 11: 54553. 5peplow pv, chung ty, baxter gd. laser photobiomodulation of wound healing: a review of experimental studies in mouse and rat animal models. photomed laser surg 2010; 28: 291-325. 6kim yd. biophysical therapy and biostimulation in unfavorable bony circumstances: adjunctive therapies for osseointegration. j korean assoc oral maxillofac surg 2012; 38:195-203. 7accorinte , m , holl and , r reis, a bortoluzzi, m , murata, 5, evaluate of mineral trioxide cement as pulp capping agent in teeth. j endod 2008 ; 34: 1-6 8pinheiro al, gerbi me. photo engineering of bone repair processes. photomed. laser surg 2006; 24: 16978 9nicola r a, jorgetti v, rigau j, pacheco m t, dos reis l m, zangaro r a. effect of low power ga al as laser (660 nm) on bone structure and cell activity: an experimental animal study. lasers med sci 2003; 18(2): 89-94. 10yousif m, ashkar s, hamade e, gutknecht n, lampert f, mir m. the effect of low level lasertherapy during orthodontic movement: a preliminary study. lasers med sci 2008; 23:27-33 11yu w, naim jo, lanzafame rj. the effect of laser irradiation on the release of bfge from 3t3 fibroblasts, photochem – photobiol 1994; 59(2): 16770. 12sennerby l, thomsen p, ericson el:early tissue response to titanium implants inserted in rabbit cortical bone. part i light microscopic observation. j mater sci mater med 1993; 4: 240-50. 13mohammed ifr, yonus na, al-tatabani ng. histopathological study of ossenointegration around titanium implant post lllt. iraqi j oral dent sci 2003; 2(1): 9-19. 14pinheiro alb, limeira f, gerbi mem, ramalho lm p, marzola c, ponzi eac. effect of low level laser therapy on the repair of bone defects grafted with inorganic bovine bone. braz dent j 2003; 14(3): 17781 15ibrahim rs. effect of low energy laser irradiation on bone healing around intraosseous titanium implants in experimentally diabetic rabbits (morphometric and histological evaluations). a ph.d. thesis, college of dentistry, university of baghdad, 2003. 16al-talabani mah. effect of 904 nm diode laser with different exposure times on titanium dental implants inserted in rabbit's tibia (histological study). a master thesis submitted to the college of dentistry, university of baghdad, 2004. 17pretel h, lizarelli rf, ramalho lt. effect of lowlevel laser therapy on bone repair: histological study in rats. lasers surg med 2007; 39(10): 788-96. 18blaya ds, pozza dh, weber jb, oliveria mg. histological study of the effect of laser therapy on bone repair. j contemp dent pract 2008; 9(6): 41-8. 19branner r, hanialadthaler mw, braunfulco o. application of the laser light of low power density, clinical &experimental investigation. curr prob derm 1988; 5:111-6. 20edmonds m, bates m, doxford m, gough a, and foster a. new treatments in ulcer healing and wound infection. diabetes metab res rev 16 suppl 2000; 1: s51–s54. 21harding kg, morris hl, and patel gk. science, medicine and the future: healing chronic wounds. br med j 2002; 324: 160-3. 22nascimento pm, pinherio lb, salgado mac, ramalho lmp. a preliminary report on the effect of laser therapy on the healing of cutaneous surgical wounds as a consequence of an inversely proportional relationship between wavelength and intensity: histological study in rats. photomedicine laser surgery 2004; 22(6): 513-8. 23gal p, vidinsky b, toporcer t. histological assessment of the effect of laser irradiation on skin wound healing in rats. photomed laser surg 2006; 24(4): 480-8. 24lacjakova k, bobrov b, polakova m. effects of equal daily doses delivered by different power densities of low level laser therapy at 670nm on open skin wound healing in normal and corticosteroid treated rats: a brief report. lasers med sci 2010; 25(5): 761-6. 25goldman lb, van lieu n. current laser dentistry. lasers surg med 1987; 6: 559-62. 26walsh lj. the current status of laser applications in dentistry. aust dental j 2003; 48: 146-55. الخالصة یوفر مما للفكیة والعظمیة الرخوة األنسجة في )حیویة مادة ( نسبیا مادة خاملة بإدخال ذلك یتم حیث المفقودة األسنان لتعویض یوفر وسیلة استثنائیة للفك السنیة اتالغرس ان :الخلفیة اعادة بناء العظم بعد الجراحة ، وھذا ما یسمى بالتأثیرالحیوي المحفز للیزر المنخفض الى لتحفیز عالج اللیزر المنخفض الطاقة اداة فعالة تستعمل ان . التعویض السني وتثبیت إسنادا .یتانیومتقییم تأثیر اللیزر المنخفض الطاقة حول الخالیا االلتھابیة في مجامیع االختبار والسیطرة وتأثیره على التئام العظم حول غرسات التتقییم تاثیر ھي ھداف ھذه الدراسة أ .الطاقة مجموعة التجربة الذي یمثلالجانب االیمن .عظم قصبة الساق ادخلت غرسات التیتانیوم في,ابیض ذكر اثنان وثالثون ارنب نیوزلندي 32استخدم :طریقة العمل والمواد المستخدمة تم تقسیم العینة الى .للغرسات الیمنى )5mw(وقوة )904nm(بطول موجة ) gaalas(اللیزر المنخفض الطاقة تشعیع الغرسات ب وتم .والجانب االیسراعتبر مجموعة السیطرة .لكل فترة ااجري التحلیل النسیجي واال لتھابي.و ستة أسابیع بالتتابع اسبوعین,اسبوع واحد,أیام 4الربع فترات , ثمانیة ارانب 8,اربعة مجامیع التحلیالت االلتھابیة اظھرت انخفاض . عة عملیة الشفاء للغرسة بوجود اشعة اللیزر اكثر مما في مجموعة السیطرةاوضحت نتائج الفحص بان تعجیل تكوین العظم وسر :النتائج . بوجود اعة الللیزر خاصة بتقدم الوقت . عظمي وتقلیل االلتھاباتھذه الدراسة اوضحت بان تطبیق اشعة اللیزر المنخفض الطاقة سرعت عملیة التكوین العظمي وااللتئام ال: االستنتاج .الغرسة السنیة ، اللیزر المنخفض الطاقة ، الخالیا االلتھابیة :الكلمات الرئیسیة yasir f.doc j bagh college dentistry vol. 27(3), september 2015 comparison of enamel pedodontics, orthodontics and preventive dentistry174 comparison of enamel color alteration between bonded and free unbonded surfaces of maxillary anterior teeth after fixed orthodontic therapy (a prospective clinical study) yasir r. abdulhuaasin al-laban, b.d.s., m.sc. (1) abstract background: the purpose of this study is to compare the color changes between the bonded middle third and the unbonded gingival and incisal thirds, fallowing fixed orthodontic treatment material and method: the color parameter l, a, b has been recorded for each thirds in upper anterior teeth by mean of easy shad device. the has been calculated for gingival, middle and incisal thirds for the upper anterior teeth in 34 patient, 17 males and 17femals, those subject undergone fixed orthodontic treatment results: the in middle bonded third is highly significant higher than that in incise and gingival thirds p<0.01 because the middle third isn’t expose to oral fluid and dental brushing since it covered by the bracket. also there was no significant difference in between the 2 sex groups conclusion: the discoloration that happened in teeth due to orthodontic treatment occur in middle thirds more than the incisal and gingival thirds and there no difference between the 2 sex groups key words: bonded surface, unbonded surface, discoloration. (j bagh coll dentistry 2015; 27(3):174-178). introduction occlusal relationship and correction of malocclusion nowadays is not only the aims of a orthodontists (1); but great interest is paid to enhance the esthetic as a patient request (2,3). a color of a tooth play a role in dental esthetics, since a white and light (less yellow) color of teeth will reduce a common complication of orthodontic (4). a reaction between enamel surface with incident light, and a perception of human eye act as contributing factors for developing a color of a tooth (5,6). it is proved that fixed orthodontics treatment will effect adversely on the tooth color (7-9), both vitro and vivo studies were done and confirming tooth color alteration fallowing debonding of orthodontic bracket even with different type of adhesive, method of removing adhesives, polishing (2,4,7,10-17) in vivo the color of the tooth can be evaluated by 2 methods the first one the naked eye (18) this method is low cost but it subjective and cant cover all shade of the teeth (19,20). the 2nd method by aid of instrument it is more precise and reliable, nowadays several commercial system available in market like tristimulus colori meters, spectroradiometer, spectrophoto meters, and digital color analyzers all these devise develop as result of converting the commission international de eclairage into numeric data. so the computer can deal with it and make them more applicable (21,22). (1)lecturer. department of orthodontics. college of dentistry, university of baghdad. generally speaking the labial aspect of the anterior teeth can be divided into gingival, middle and incisal third. all the labial aspect of anterior teeth will receive acid etching and primer, and will be expose to oral environment during orthodontic treatment period except the center of the middle third were the bracket with adhesive place on (23,24) so it is wise to split the gingival and incisal third and regard them as free unbonded surface, while the middle third as bonded surface the aim of this study to evaluate and camper the color change due to orthodontic treatment, between the bonded and free unbonded surface of the labial aspect of the upper teeth, gender difference was also investigated. materials and methods forty patient (twenty males and twenty females) aged between 18-40 years old were attending the orthodontics clinic, all of them need for fixed appliance therapy, all those patient has been signed the consent form for this research the sample criteria of the patient selection (1) all of them have full permanent dentition and they need fixed orthodontic appliance of crowding less than 4mm (2) no caries, restoration, prosthesis and decalcification in the teeth (3) no gingival inflammation (4) no smoking habit. all the patient instructed to follow oral hygiene protocol including regular brush the with fluoridated tooth paste and never use any mouth wash like chlorhexidine to overcome the j bagh college dentistry vol. 27(3), september 2015 comparison of enamel pedodontics, orthodontics and preventive dentistry175 possibility of teeth staining, all the patient has been followed periodically to confirm the condition of oral hygiene, all of them subjected to motivation for the teeth brushing as they not adapted to brush their teeth with presence of fixed appliance at the time of bonding procedure cheek retractor was applied then the teeth were polished with non fluoridated pumice with rubber cup, after that all teeth were rinse with water, (27) the teeth should kept in wet condition to avoid any color changes due to dryness. color measurement occurs by using spectrophotometer vita easy shade compact (vita zahn fabrik, bad sackingen, germany) (25), the teeth included in this study are 6 anterior teeth so the color of the gingival third, middle third and incisal third for the upper anterior teeth has been recorded before the bonding procedure. the color of the teeth can be explained by 3 parameter (l,a,b) according to commission of international of del'eclairage (26), were the l parameter represent to the value or degree of lightness in munsell system, ranging from 0 (black) to 100 white, the a parameter represent a measure of redness (a >0) or greenness (a<0) and b represent parameter of yellowness (b>0) or blueness (b<0) (10). the easy shade device has been used according manufacturer instruction to avoid any error in color measurement. all of these measurement occurred in morning under the same fluorescent lamp of the dental unite and by the same operator who undergone the calibration for using this device 3 week before starting of this study. so the operator will take 3 color parameter (l,a,b) for each third of upper anterior teeth. by holding the sterile intra-oral device tip (mouth piece) at the right angle to the labial surface of the tooth, near the gingival margin, at center of middle third and near the incisal margin for recording the gingival, middle and incisal third respectively. the same procedure color recording will repeated after the end of orthodontic treatment, when deboning and cleaning of adhesive and polishing being complete. the average of each color parameters (l, a, b) has been calculated to facilitate the color explanation the gingival, middle and incisal third of the upper anterior teeth, so we will deal with gingival thirds of upper anterior teeth as one unite by calculating the average of it, the same things for middle and incisal third. the color difference ∆e for gingival middle and incisal thirds calculated using the difference in l, a. and b values pre and post fixed appliance therapy according to fallowing equation ∆e = [(l1-l2) 2+ (a1-a2) + (b1-b2)) 2]½ where the l1, a1, b1 represent average value for each third preoperatively and l2, a2, b2 corresponding the average value for each third postoperatively as result of poor oral hygiene and development of gingival inflammation, the patients can't tolerate and obey the strict oral hygiene measures 6 males and females had been excluded from this study. so the rest only 34 subject 17 males and 17 females as sample of the current study. after the first registration of the color parameter complete, conventional acid etching has been applied for all labial surfaces of the teeth. then rinsed with water for 30 sec and dried with oil free compressed air till chalky appearance happened, the bond system used is light cure ormco enlight (usa) were the primer applied to whole labial surface of the teeth then the stainless steel bracket with adhesive paste placed, all the bonding procedure has happened according the manufacturers instruction. the excess of the adhesive was removed from brackets borders by probe; light cure was applied for 20 second (10second for mesial and 10 second for distal aspect). at the end of orthodontic treatment the brackets were removed by help of bracket removing pliers, the remnants of the adhesive was removed by using 12 fluted tungsten carbide bur (komet gebr, brasseler, lamgo, germany), with low speed and water cooling, then finishing occurs by extra fine sof-lex polishing discs (3m fspe dental product; 3m center) till restoration of the luster of the enamel, new burs and discs were used for each patients. the process of adhesive removal and finishing happed at level of naked eye, (13) by the some operator in same environment (13). following the adhesive removal and polishing, 2nd color measurement were record for the same teeth included in this study and in the same manner as the first measurement recorded. the intra-examiner calibration has been done before the beginning of study to confirm the reliability and accuracy of color measurements. seven patients were randomly selected, so the color measurement recorded to them for their teeth, and after 2 week the second color measurement recorded, t-test show non significant difference between the first and second records statistical analysis descriptive statistics for male and female groups also the independent sample t-test was applied to detect the gender difference. one way anova test was used in this study to compare j bagh college dentistry vol. 27(3), september 2015 comparison of enamel pedodontics, orthodontics and preventive dentistry176 the color changes between the gingival, middle and incisal thirds results table 1 shows descriptive statistics , including mean and standard deviation of the in both gender for the incisal , middle and gingival thirds, it seems that the mean of the in middle thirds is 4.948 and 4.967 for the males and females groups respectively which are higher than that in the incisal and gingival third for both gender ; the independent sample t test shows non significant difference in between the males and females groups in gingival , middle and incisal, so the both groups was pooled into one group in table 2 shows the descriptive statistics for whole sample, and the one way anova test shows highly significant differences between the value of the for the gingival, middle and incisal thirds p<0.001,while table 3 the lsd test shows that the in middle third is highly significantly differ with both incisal and gingival third , while no significant difference in presence between the incisal and gingival third. table 1: descriptive statistics and gender difference for the regions descriptive statistics gender difference (d.f.=32) males (n=17) females (n=17) mean s.d. mean s.d. mean difference t-test p-value gingival 3.710 1.241 4.393 0.871 -0.683 -1.425 0.171 (ns) middle 4.948 0.686 4.967 1.181 -0.019 -0.044 0.965 (ns) incisal 3.756 0.852 3.532 1.267 0.224 0.464 0.648 (ns) table 2: descriptive statistics and regions' difference for the regions descriptive statistics regions difference n mean s.d. f-test p-value gingival 34 4.052 1.101 8.441 0.001 (hs) middle 34 4.958 0.940 incisal 34 3.644 1.057 table 3: lsd test after anova for the regions mean difference s.e. p-value gingival middle -0.906 0.327 0.008 (hs) incisal 0.408 0.327 0.218 (ns) middle incisal 1.314 0.327 0.000 (hs) discussion day by day the attention toward the esthetic dentistry increase, the color of the teeth is one of the important factors in determination of the esthetic, in this prospective vivo study we are focus on upper 6 anterior teeth which regards as the most exhibited during smilling3. this study confirm the finding of previous studies regarding the color of the teeth become darker fallowing the orthodontics treatment , so it agrees with other vivo studies like karamouzos et al (12) and almaaitah et al (2) , also our finding agrees with the other vitro studies like zuher etal (13), tarkyali et al (10) and bonuck et al (11). our finding also supports the above previous studies concerning the enamel surface and texture will never return back to its original status due to changing in surface nature as result of acid etching, irreversible retention of resin tags in enamel material and micro cracking , chipping and scratching in enamel during debonding and cleaning of adhesive ruminant fallowing debonding , all these contributing factors will make the enamel surface more liable to absorb the colorant material and stains from different source in oral environment, in other hand the irreversible infiltrated adhesive resin tags in enamel surface to depth 30 – 50 um johnson (28), the tags are more labial for staining according to mandim (29) ,and they tend to alter the optical behavior of enamel and they will make it more dull and dark appearance . our finding show no significant difference between males and females groups, this finding might be explained by the fact that females are more interested in their esthetics so they try to take more care of their teeth and brushing them, this can be compensated for by heavy brushing manners in males, as males are more muscular j bagh college dentistry vol. 27(3), september 2015 comparison of enamel pedodontics, orthodontics and preventive dentistry177 than females, but this finding was disagreed with al-maaitah et al (2) the disagreement might be due to the difference in sample criteria and methodology in this study the was investigated in each third of the upper anterior teeth separately , the middle third where the bracket placed regarded as bonded surface since this area will never expose to oral environment during the fixed orthodontic treatment, while gingival and incisal thirds will receive acid etching and primer application and are exposed to oral environment and brushing during the fixed orthodontic treatment , so these two thirds term as unbonded free surface, so these two thirds were encountered different environment if we compare them with middle third which is terms as bonded surface while the incisal and gingival thirds term as unbonded free surface , so in this study we were deal with bonded and unbonded free surface as two separated entity. to facilitate the statistical analysis, the average of the gingival, middle and incisal thirds of the upper anterior teeth were calculated for the value l, a, b so when we count the ,it will be for the gingival thirds of the all upper anterior, the same things for the for middle and incisal thirds. the anova and the lsd tests show that the in middle thirds are highly significant and they are greater than those in incisor and gingival thirds; because the primer in the gingival and incisal thirds can't persist for the long time, this might be due to dissolution of all or part of the primer resin infiltrated in enamel material in gingival and incisal thirds , as result to exposure to oral fluid and the dental brushing may plays as helpful role to remove the infiltrated primer resin via abrasion , also the primer is thin film and low viscosity (low filler content) if we compare it with the adhesive past that used in bracket cementation in middle third , the adhesive past is thick consistency and covered by bracket during the fixed orthodontic treatment , so it will be away from dental brushing and oral environment particularly the center of middle third, that is why the middle third tend to be darker in color (greater ), since the resin tags in middle thirds are more heavy and persisting due to omitting the exposure to oral fluid and dental brushing as they covered by the bracket during the fixed orthodontic treatment it is worthy to say that the human eye can recognize or detect the color difference if the 3.7 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current principles and techniques. 5th ed. st. louis: mosby; 2012. p. 728-55. 25judeh a, al-wahadni a. a comparison between conventional visual and spectrophotometric methods for shade selection. quintessence int 2009; 40: e69-79. 26brewer jd, wee a, seghi r. advance in color matching. dent clin north am 2004; 48: 341-58. 27knosel m, eckstein a, helms h. durability of esthetic improvement following icon resin infiltration of multibracket-induced white spot lesions compared with no therapy over 6 months: a single center, splitmouth, randomized clinical trial. am j orthod dentofac orthop 2013; 144: 86-96. 28silverstone lm, saxton ca, dogon il, feierskov o. variation in pattern of acid etching of human dental enamel examined by scanning electron microscopy. caries res 1975; 9: 373-87. 29mundim fm, garcia l da f, pires-de-souza fed c. effects of staining solutions and repolishing on color stability of direct composites. j appl oral sci 2010; 18(3): 249-54. 30johnstonwm, kao ec. assessment of appearance matches by visual observation and clinical colorimetry. j dent res 1989; 68:819-22. الخالصھ في االسنان االمامیھ للفك العلوي) الثلث اللثوي و القطعي( والثلثین غیر الملتسقین) طيالثلث الوس(الدراسھ ھو مقارنھ تغیر اللون بین السطح الملتسق هالھدف من ھذ لطھ جھاز االیزي شید ، بعد ذلك تم حساب تغیر اللون لكل ثلث على حدى قبل عممعاییر اللون ل ا ب اخذت لكل ثلث من االسنان االمامیھ العلویھ بواس: الطریقھ والمواد المستخدمھ ذكور17اناث و 17, 34ابت وبعدة لعینھ من االشخاص عددھم تقویم االسنان الث الن االخیرین مكشوفین للسائل اللعابي و تحت تاثیر تفریش ,مما ھو علیھ في الثلثین اللثوي و القطعي ) بنسبھ ذو اھمیھ(اكثر الثلث الوسطي یعاني تغیر باللون: النتائج و النقاشات لم نجد اي فرق مھم في تغیر اللون بین الجنسین. االسنان ھذا التغیر في اللون لیس فیھ .الوسطي اكثر مما ھو علیھ في الثلثین اللثوي و القطعي نحو االطوخ ویكون في الثلثتقویم االسنان الثابت یودي الى تغیر بلون االسنان : االستنتاجات فرق مھم بین الذكور و االناث omar f.doc j bagh college dentistry vol. 27(3), september 2015 the effect of oral and maxillofacial surgery and periodontics 116 the effect of cigarette smoking on salivary iga and periodontal disease omar husham ali, b.d.s., m.sc. (1) abstract background: chronic periodontitis is an inflammatory disease of tissues supporting the teeth. salivary compositions have been most intensely studied as a potential marker for periodontal disease. in this study, analysis of saliva provides a simple and non-invasive method of evaluating the role of salivary iga (s-iga) levels in periodontal disease by detecting the level of (s-iga) in patients with chronic periodontitis smokers and non smokers patients and correlate the mean (s-iga) levels with clinical periodontal parameters plaque index (pli) gingival index (gi), probing pocket depth (ppd) and clinical attachment level (cal). materials and methods: the study samples consists of (15) patients with chronic periodontitis who were non smokers (group i) and (15) patients with chronic periodontitis who were smokers (group ii) of both gender with an age ranged (35-45) years were the periodontal parameters used in this study (pli, gi, ppd and cal), unstimulated salivary sample were collected from all subjects and the levels of salivary iga (s-iga) in each sample were analyzed for each group by using enzyme-linked immunosorbent assay (elisa) technique. a statistical analysis was done by using excel 2013. results: there was a significant difference with high mean level in the clinical periodontal parameters in smokers group compared to non smokers with chronic periodontitis (pli, ppd and cal) except gi which showed no significant difference between the same groups. the biochemical finding showed significant difference with low mean level for (s-iga) in smokers group compared to non smokers. conclusion: the findings in this study showed that the concentrations of salivary iga might be used as an indicator for periodontal disease progression in smokers with chronic periodontitis as a resultant to the effect of smoking which lowering the concentration of the salivary iga and subsequent reducing of the host’s defense lead to increase in the progression of periodontal disease. keyword: chronic periodontitis, smokers, (s-iga), enzyme-linked immunosorbent assay (elisa), saliva. (j bagh coll dentistry 2015; 27(3):116-119). introduction periodontal disease (pd) is a disease with multiple factors that consists of hard and soft dental supporting tissues, microbial colonization, and host immune/inflammatory responses (1). smoking is consider a major risk factor for the periodontal disease development and progression (2) . the smoking effects on the periodontal tissue depend on the number of the cigarette smoked daily and the duration of the habit (3) .the higher the occurrence and the severity of periodontitis among cigarette smokers may be explained by the impairment of the host immune system as a result of cigarette smoking. indeed, it has been shown that polymorph nuclear leukocyte functions such as chemotaxis, phagocytosis, and oxidative burst are decreased by the cigarette smoking substances (4,5). saliva is a complex fluid containing large number of host defense factors derived from the different salivary glands and the crevicular fluid (6). immunoglobulins (igs) are protein molecules produced by specialized immune systems in response to the external agents penetrations, such as viruses, bacteria, protozoans, fungi, tumor cells, or tissues that are recognized as foreign because of the cell surface antigens presence (7). (1) assistant lecturer, department of periodontics, college of dentistry, university of baghdad. the function of igs is to bind with specific antigen molecules and, consequently, target bound molecules for inactivation and/or elimination of toxins, micro-organisms and parasites from the organism (8). the humoral host immune responses play an important role in the oral environment protection because of the capability of antibodies to inhibit the attachment of microorganism to cell surfaces and aggregation/opsonization of these microorganisms (1). in addition, antibodies are associated with alternative pathways that are also important in the colonization prevention and promotion the lysis of microorganisms, as well as neutralization of the toxic products (1,9) . salivary iga is considered as the principal line of defense in the oral cavity against microorganisms invasions and plays an important role in the interactions of bacterial host (10,11) . materials and methods the study participants included in the study were drawn from patients attending the department of periodontics in the collage of dentistry, university of baghdad. the study population included thirty patients with chronic periodontitis of both gender with an age ranged (35-45) years with no history for any systemic disease, chronic periodontitis in patients was defined as the presence of teeth with probing pocket depth ≥4mm with clinical attachment loss, j bagh college dentistry vol. 27(3), september 2015 the effect of oral and maxillofacial surgery and periodontics 117 this made according to the international classification system for periodontal disease (12), 15 of them were non smokers (group i) and 15 were smokers (group ii).the criteria of smoker patients which were regularly smoked at least 10 cigarettes on average per day (13). the exclusion criteria applied were a course of anti inflammatory or antimicrobial therapy within the previous 3 months, a history of regular use of mouth washes, patients undergoing chemotherapy, radiotherapy, or medications that cause xerostomia. the clinical parameters, plaque index (pli) (14), gingival index (gi) (15) probing pocket depth (ppd) (16) and clinical attachment level (cal) (17) have been clinically recorded. the subject rinses his mouth several times by water and then waits for 1-2 minutes for water clearance and then the unstimulated saliva was collected between 9-12 am. the collected samples centrifuged at 4000rpm for 10 min, freeze at (-20º c). after all the samples were collected, the levels of salivary iga were estimated by using enzymelinked immunosorbent assay (elisa) technique following the guidelines of the commercial kit provided by demeditec diagnostic gmbh d24145 kiel (germany). the results were statistically analyzed with t-test and pearson's coefficient of correlation. results the mean and standard deviation of pli, gi, ppd, cal and s-iga in group i and group ii were described in the (table 1) which showed increasing in the mean of these parameters for chronic periodontitis smokers (group ii) as compared to chronic periodontitis non smokers (group i) except for gi and s-iga which showed reduction in the mean of these parameters for (group ii) compared to (group i). when the mean of clinical and biochemical parameters were compared between groups (table 2), the pi, ppd, cal and s-iga showed significant differences between (group i) and (group ii) while non significant relationship in the gi were found in the comparison between the same groups. the coefficient of correlation (r) in these groups described in the (table 3) showed that s-iga had inversed weak correlation in relation with gi and cal for group i. table 1: records the mean and standard deviation of pli, gi, ppd, cal and s-iga in group i and group ii s-iga cal ppd gi pli descriptive statistic groups 310.5333 4.12 4.06667 1.506 1.22 mean group i 63.43486 0.182052 0.144749 0.49058 0.256905 ±sd 244.4667 4.58667 4.65333 1.42 1.6 mean group ii 39.33168 0.46578 0.60458 0.60261 0.3251 ±sd table 2: inter group comparison of means of pl, gi, ppd, cal and s-iga between group i and group ii. s-iga cal ppd gi pli 1.7613 1.761 2.146 2.145 1.761 t-test 0.002 0.001 0.001 0.669 0.001 p-value s s s ns s sig s= significant, ns= non significant table 3: correlation coefficient (r) s-iga and pli, gi, ppd and cal for group i and group ii. cal ppd gi pli s-iga groups p r p r p r p r g1 0.464 -0.2044 0.611 0.1428 0.996 -0.0012 0.5707 0.1592 0.267 0.3060 0.592 0.1505 0.854 0.0517 0.530 0.1759 g2 discussion there was a significant difference in pli in chronic periodontitis smokers (group ii) as compared with chronic periodontitis non smokers (group i) and the findings of higher pli in smokers are similar to a large body of controlled cross-sectional studies (18-20) and longitudinal studies (21,22). the increased level of debris which has been observed in smokers group attributed to the personality trait leading to decrease in the oral hygiene and / or increase plaque formation rates (23). although there was no significant difference in gi between group i and group ii and this might be coincided with the findings of zuabi et al (24) , the j bagh college dentistry vol. 27(3), september 2015 the effect of oral and maxillofacial surgery and periodontics 118 mean of gi in smokers group showed low level than that in non smokers group and this might be due to the effect of smoking which had suppressive effect on the vasculature can be observed through less gingival redness, lower bleeding on probing and fibrous texture of the gingival tissue. there was a significant difference with high level in the mean of ppd and cal in smokers group compared with non-smokers group and this could be due to the effect of cigarette smoking on lowering of the eh (oxidation reduction potential) and this could cause an increase in anaerobic plaque bacteria (25) ,so that lead to loss of balance in the host-bacterial interactions and this might be due to changes in the subgingival plaque composition, with increase in the numbers and / or virulence of pathogenic organisms; the host response changes against bacterial challenge, or a combination of both (26) , these findings were in agreement with mahuca et al. (27) . the result of s-iga showed significant difference with low mean level in smokers as compared with non smokers group and this might be due to the effect of cigarette smoking which may alter t-cell immunoregulation and b-cell differentiation, generating a decrease in production of s-iga, which protect the oral mucosa against periodontal pathogenic bacteria. a low level of salivary s-iga can be regarded as a risk factor for oral diseases, especially periodontal diseases (28,29) and this was in agreement with al-talib (30).as a result to small sample size and the sample taken from the saliva that was less site specificity as compared with the sample taken from gingival crevicular fluid so that there was weak correlation between s-iga and clinical periodontal parameter in both groups. references 1. teng yt. protective and destructive immunity in the periodontium: part 1--innate and humoral immunity and the periodontium. j dent res 2006; 85(3):198208. 2. american academy of periodontology. tobacco use and periodontal patient (position paper). j periodontal 1996; 67: 51-6. 3. calcina g, ramon j, echeverria j. effects of smoking on periodontal tissue. j clin periodontol 2002; 29: 771-6. 4. mcguire jr, mcquade mj, ross man ja. garnick j. cotinine in saliva and gingival cervical fluid of smokers with periodontal disease. j periodontal 1989; 60: 17681. 5. sasagawa s, suzuki k, sakatani t, fujioka t. effect of nicotine on the function of human polymorphonudear leukocytes in vitro. j leukoc biol 1985; 37: 494502. 6. lavelle christopher l.b. applied oral physiology. 2nd ed. butterworth and co ltd; 1988. p.133-134 7. pollanen mt, salonen ji, uitto v-j. structure and function of the tooth epithelial interface in health and disease. periodontol 2000 2003; 31:12–31. 8. haber j, williams j, crowley m, mandell r, joshipura k, kent rl. evidence for cigarette smoking as a major risk factor for periodontitis. j periodontal 1993; 64:16–23. 9. albandar jm, denardin am, adesanya mr, diehl sr, winn dm. associations between serum antibody levels to periodontal pathogens and early-onset periodontitis. j periodontol. 2001; 72(11):1463-9. 10. brandaeg p. immunology of inflammatory periodontal lesions. int dent j 1973; 23: 438-54. 11. marcoe h, lavoie mc. oral microbial ecology and the role of salivary immunoglobulin a. microbiol mol biol rev 1998; 62:71-109. 12. lang np, bartold pm, cullinam m et al. international classification workshop. consensus report: chronic periodontitis. annals of periodontol 1999; 4: 53. 13. martinez-caunt p, lorca a, magan r. smoking and periodontal disease severity j clin periodontol 1995; 22: 743-9. 14. silness j, löe h. periodontal disease in pregnancy. ii correlation between oral hygiene and periodontal condition. acat odontal scand 1964; 22: 121-35. 15. löe h. the gingival index, the plaque index and retention index system. j periodontol 1967; 38(6): 610-6. 16. carranza af, newman mg, takei hh, klokkevold pr. carranza’s clinical periodontology. 11th ed. elsevier; 2012 17. löe h, brown ls. early onset periodontitis in the united states of america. j periodontal 1991; 82 60816. 18. feldman rs, bravacos js, rose cl. associations between smoking, different tobacco products and periodontal disease indexes. j periodontal 1983; 54: 481–8. 19. muller h-p, sabine s. and achim h. bleeding on probing in smokers and non-smokers in a steady state plaque environment. clinical oral investigations 2004; 5:177-84. 20. gala s, pesek f, murray j, kavanagh c, graham s, walsh m. design and pilot evaluation of an internet spit tobacco cessation program. j dent hyg 2008; 82(1):11. 21. bergstorm j, perber h. tobacco use as a risk factor. j periodontal 1994; 65: 545–50. 22. grossi sg, genco rj, machtei ee, ho aw, koch g, dunford r, et al. assessment of risk for periodontal disease ii. risk indicators of alveolar bone loss. j periodontal 1995; 66: 23–9. 23. tonetti ms. cigarette smoking and periodontal disease: etiology and management of disease. ann periodontol 1998; 3: 88-101. 24. zuabi o, machtei ee, ben aryeh h, ardekian l, peled m, laufer d. the effect of smoking and periodontal treatment on salivary composition in patients with established periodontitis. j periodontal 1999; 70: 1240–6. 25. kenny eb, saxe sr, bowles rd. the effect of cigarette smoking on anaerobiosis in the oral cavity. j peridotontol 1975; 46: 82-5. 26. hashim f. assessment of alveolar bone loss and measurement of periodontal status by clinical and digital radiographic analysis in smokers and nonj bagh college dentistry vol. 27(3), september 2015 the effect of oral and maxillofacial surgery and periodontics 119 smokers. (comparative study). a master thesis, college of dentistry, university of baghdad, 2007. 27. machuca g, rosales i, lacalle jr, machuca c, bullon p. effect of cigarette smoking on periodontal status of healthy young adults. j periodontal 2000; 71: 73-8. 28. krall ea, garvey aj, garcia ri. alveolar bone loss and tooth loss in male cigar and pipe smokers. j am dent assoc. 1999; 130(1): 57–64. 29. brancatisano fl, maisetta g, barsotti f, esin s, miceli m, gabriele m, giuca mr, campa m, batoni g. reduced human beta defensin 3 in individuals with periodontal disease. j dent res 2011; 90(2): 241–5. 30. al-talib z. periodontal health status with serum and salivary immunoglobulins analysis for smokers and non smokers (comparative study). a master thesis, college of dentistry, university of baghdad, 2008. لخالصھا في ھذه .تملھ المراض اللثھشالتراكیب اللعابیھ تدرس بصوره مكثفھ كعالمھ م.النساغ المزمن ھو مرض التھابي یصیب االنسجھ الداعمھ لالسنان -:الخلفیھ ض اللثة عن طریق الكشف عن مستوى في أمرا) أ( االجسام المضاده اللعابیھ نوع مستویات لتقییم دور مغزوهتحلیل اللعاب یوفر طریقة بسیطة وغیر الدراسھ مع معلمات اللثة ھذه المضادات المدخنین وغیر المدخنین من المرضى وربط مستویات في في المرضى الذین یعانون من التھاب اللثة المزمن ھذه المضادات ).calو pli ،gi ،ppd(السریریة المدخنین وھؤالء ھم المجموعھ االولى من العینات غیر النساغ المزمن وھم من مریض مصابین ب 15عینات الدراسھ تتالف من -:المواد وطرق العمل . سنھ) 45-35(مریض مصاب بالنساغ المزمن وھم من المدخنین وجمیع المرضى من كال الجنسین وتتراوح اعمارھم من 15والمجموعھ الثانیھ تتالف من ھي معلمات اللثة المستخدمة في ھذه ) cal(ومستوى المرفق السریریة ) ppd(لجیب ، سبر عمق ا)gi(مؤشر اللثة ) pli(مؤشر اللوحة الجرثومیھ تحلل في كل عینھ لكل مریض في كل مجموعھ ) أ( الدراسة،عینھ من اللعاب غیر المحفز تجمع من جمیع المرضى ومستوى االجسام المضاده اللعابیھ نوع معلمات اللثة السریریة وایجاد , ) أ( یعمل تقییم احصائي لمعرفة مستوى االجسام المضاده اللعابیھ نوع . (elisa)بواسطة تقنیة فحص االنزیم المرتبط مناعیا .العالقھ بین معدل مستوى االجسام المضاده اللعابیھ والمعلمات اللثویھ السریریھ ولكل مجموعھ في مجموعة المدخنین المصابین (pli, ppd and cal)تشمل والتي ریریھكان ھناك فرق معنوي مع معدل عالي المستوى في معلمات اللثھ الس-:النتائج ئج اوضحت نت.عدم وجود فرق معنوي بین نفس المجامیع اظھرتوالتي ) gi(ماعدا مؤشر اللثھ بالنساغ المزمن بالمقارنھ مع مجموعة الغیر المدخنین .في مجموعة المدخنین مقارنة بغیر المدخنین ) أ( اللعابیھ نوع ضادهاالجسام المالكیمیاء الحیویھ وجود فرق معنوي مع ھبوط بمعدل ربما تستعمل كمؤشر لتقدم مرض اللثھ المزمن في المدخنین المصابین ) أ( نوع بینت ان تراكیز االجسام المضاده اللعابیھالنتائج في ھذه الدراسھ -:االستنتاج مما یؤدي الى زیادة التقدم متبوع بانخفاض مقاومة الحائل ) أ( لذي یقلل تركیزاالجسام المضاده اللعابیھ نوع بالنساغ المزمن وذلك كمحصلھ لتاثیر التدخین وا .في امراض اللثھ اللعاب, فحص االنزیم المرتبط مناعیا, االجسام المضاده اللعابیھ نوع الفا, المدخنین, النساغ المزمن-:الكلماتمفتاح sura.doc j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 48 a comparative evaluation of the centering ability and canal transportation of simulated s-shaped canals instrumented with different nickel –titanium rotary systems sura a. jaber, b.d.s. (1) zainab m. abdul-ameer, b.d.s., m.sc. (2) abstract background: the purpose of this study was to evaluate and compare centering ability and canal transportation of simulated s-shaped canals instrumented with four different types of rotary nickel-titanium systems. materials and methods: forty simulated s-shaped canals in resin blocks were divided into four groups of ten each and were instrumented to an apical size 25 by different instrumentation technique using protaper universal files (group a), protapernext (group b), reciproc (group c) and waveone (group d).centering ability and canal transportation was measured at (11) measuring points from d0 to d10 bysuperimposion of the preand postoperative images obtained by using digital camera in standardized manner. an assessment of the canals shape was determined using photoshop cs2 and autocad software. the data were analyzed statistically using anova and lsd test. results: in terms of centering ratio values, there was no statistically significant difference among the four groups at the coronal portion of the canals, with protaper system showing the least centering ability at all levels except at apical foramen. at the apical curvature, the reciproc and waveone groups showed better centering ability than protapernext and the difference was statistically highly significant among them at these points, while at the coronal curvature the protapernext showed better centering ability than reciproc and waveone. canal transportation was seen in all groups but the protaper systems showed more transportation values at almost levels when compared with the other groups with the least values by protapernext at the coronal curvature and the least values by reciproc and waveone at the apical curvature. conclusions: under the conditions of this study, protapernext ,waveone and reciproc instruments maintained the original curvature significantly better than protaperuniversal at almost levels. protapernext showed a better shaping ability than reciproc and waveone at the coronal curved section while at apical curved section reciproc and waveone showed a better shaping ability than protapernext. key words: centering ability, canal transportation, protapernext, reciproc, waveone. (j bagh coll dentistry 2016; 28(1):48-56). introduction schilder in 1974 described five design objectives for canals to be filled with guttapercha. these are: 1) the shape should be a continuously tapered funnel from apex to access cavity, 2) cross-sectional diameters should be narrower as we move apically, 3) the shape of the original canal should be maintained, 4) the original position of the apical foramen should be maintained, and 5) the apical opening should be kept as small as practical. four important biological objectives were also described: 1) confinement of the preparation to the roots themselves, 2) avoidance of further irritation or infection of the peri radicular tissues from necrotic debris forced beyond the foramina, 3) removal of all tissue, vital and necrotic, from the main root canal, and 4) creating sufficient space for intracanal medicaments and irrigation. (1) these objectives are still considered in today’s mechanical preparation of root canals. (1)master student, department of conservative dentistry, college of dentistry, university of baghdad. (2)assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. the aims of root canal treatment are to eliminate microorganisms, to remove infected and necrotic pulpal remnants and to shape the root canal system in order to facilitate irrigation and the placement of a medicament and /or filling material (2). at the same time, the procedure should avoid any iatrogenic events, such as fracture of the instruments, transportation of the root canal, formation of a ledge or perforation of the tooth. maintaining the original canal shape and avoiding canal aberrations like canal transportation is challenging, especially when preparing severely curved root canals (3). previous research on root canal morphology has reported that root canals not only have mesiodistal direction but also bucco-lingual curvature (4). the preparation of this type of canal is difficult with stainless steel instruments. similarly ni-ti rotary instruments, owing to their shape memory properties and super elastic behavior protected the original canal curvature in extremely curved or sshaped canals but this still remains a challenge(5). numerous root canal shaping techniques with all of the niti systems have been advanced to maintain the original canal shape and thus remain better centered (6). new j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 49 concept for niti files has been introduced with different working motions that finish root canal shaping with only a single file (7). up to now, there have been two sorts of file system composition, that is, single-file system and multi-file system. single-file system with reciprocating motions (waveone and reciproc), while multi-file system with continuous rotation (protaperuniversal and protapernext). it is demonstrated reciprocation has better performance than continuous movements (8). the aim of the current study was to evaluate and compare centering ability and canal transportation of simulated s-shaped canals instrumented with four different types of rotary nickel-titanium systems. materials and methods a total of 40 s-shaped simulated plastic canals (endo training bloc-s; dentsply-maillefer) made of clear polyester resin were used in this study, these blocks were divided into four groups of ten each. all the simulated canals were standardized as follows: they were 16.5mm long, the apical foramen diameter was 0.15 mm, and the initial taper was 0.02. the radius and angle of curvature, respectively, were 5mm and 35◦ for the coronal curvature and 4.5mm and 30◦ for the apical curvature as shown in figure (1). figure 1: s-shaped simulated canal. prior to experimental instrumentation of the resin blocks, all canals were stained with blue ink to obtain a clear image of the canal. three landmarks were made with a round bur in the resin blocks from sidewall to near the inner and outer curve of the canal without penetrating into the canal. these landmarks ensured a precise alignment during superimposition of preand postinstrumentation images. the resin blocks were then numbered for identification. a specific platform with white background was built to take pictures of the canals before and after shaping (figure 2). this set-up allowed precise camera and plastic block repositioning. for calibration, a ruler was fixed adjacent to the plastic block (its units in the images were used for converting measurement to real dimension in mm) and holes were used as a size reference with 600% magnification (9). figure 2: specific platform with white background in order to facilitate the preparation of the canals, a custom made mold was used to hold each resin block during instrumentation, which covered almost the entire canal to ensure that the preparation was made in a purely tactile sensation. the forty simulated canals were randomly divided into four groups according to the instrumentation system used with ten blocks each. instrumentation of simulated canals a total of the simulated canals were prepared by using a pre-programmed setting of electric speedand torque-controlled endodontic micromotor xsmart plus protapernext (dentsplymaillefer). all of the canals were enlarged by the researcher. the canals were prepared to a working length (wl) of 16.5 mm. all canals were enlarged to apical size 25. the canals were first checked with #10 k-file (flexofile; dentsply-maillefer,) to confirm patency and precisely determine the working length. before shaping, each instrument was coated with a lubricant (glyde file prep; dentsply-maillefer), and copious irrigation with distilled water was performed repeatedly before and after the use of each instrument by irrigating syringe with 27gauge needle; approximately 5 ml of water for each canal (10). for standardization; the position and angle of the hand piece was fixed at each time during preparation perpendicular to a line drawn on the mold. each instrument was used to enlarge two canals and then discarded. group (a): ten simulated canals were prepared by rotary protaper universal systems. the instruments were used in a crown-down manner by x-smart, dentsply with recommended torque of (2.0 ncm) and rotation speed of (300 rpm) in a continuous in-and-out movement with a suitable force; they were never forced apically (11), the preparation sequence was as follows: j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 50 1an iso no.10 k-file was used to establish a glide path. 2s1 and s2 files were used to 2/3 of the wl (11 mm). 3instrumentation was completed with the s1, s2, f1 and f2 to the full estimated working length (16.5) (12). to optimize safety and efficiency, the shaping files (s1, s2) are used, like a brush, to laterally and selectively cut dentin on the outstroke. once the file had reached to the end of the canal and had rotated freely, it was withdrawn from the canal. the protaper files flutes were frequently cleaned using gauze with 70% ethyl alcohol (13). 4-the canals were irrigated with distilled water after each file was withdrawn from the canals, recapitulated and established patency, then reirrigated to remove the debris from the canal. group (b): ten blocks were prepared by rotary protapernext system. the instruments that used in the preparation were ( x1 , x2) at a rotational speed of 300 rpm and 2 ncm torque in outward brushing motion in all direction east ,west, north, south. importantly, this method of use would enable any given ptn file to passively move inward, follow the glide path, and progress toward the working length. the sequence of preparation was as follows: 1an iso no. 10 k-file was used to establish a glide path. 2x1 file was advanced in the canal until resistance. the file was then removed, the flutes were cleaned were frequently cleaned and inspected using gause soacked with 70% ethyl alcohol and the canal was irrigated using distill water. this sequence was repeated until the x1 file reached the full working length. 3x2 file was used in the same sequence as x1 until it reached full working length. the canal was irrigated after each instrument was withdrawn from the root canal, recapitulate and confirm patency, then re-irrigate to liberate debris from the canal (14). group (c): ten blocks were prepared by reciproc syste. this was accomplished by establishing a smooth glide path with iso no. 10 stainless steel hand file. then commence the preparation with r25 reciproc file having a size 25 at the tip and a taper of 0.08 over the first 3 mm was used in a reciprocating, slow in-and-out pecking motion according to the manufacturer’s instructions and xsmart program was set at “recproc all” mode when reciproc was used. a light pecking motion was used to advance the file tip followed by a 2.5-3mm passive penetration cycle into the canal, then repeated these cycles until working length was reached. the flutes of the instrument were cleaned after three in and out-movements (pecks), using gauze soacked with 70% ethyl alcohol then the canal was irrigated, recapitulated and re-irrigated (15). group (d): ten canals were prepared by wave one reciprocatin. this was accomplished by establishing a smooth glide path with iso no. 10 stainless steel hand file. then starting with primary reciprocating wave one file having a size 25 and a taper of 0.08 was used in a reciprocating, slow in-and-out pecking motion according to the manufacturer’s instructions and xsmart program was set at “waveone” mode when wo was used. a light pecking motion was used to advance the file tip followed by a 2.5-3 mm passive penetration cycle into the canal, and then these cycles were repeated until working length was reached. the flutes of the instrument were cleaned after three pecks using gause soacked with 70% ethyl alcohol. then the canal was irrigated, recapitulated and re-irrigated (15). once the preparation of samples was completed, red ink was injected into the canal space within each resin block with a syringe. each block was then re-mounted on the platform then the post-instrumentation images were acquired by the mentioned camera. the images were saved in .jpg format at a resolution of 5760 x 3084. photoshop (cs2 extended adobe systems) was used to superimpose and standardize preand post-instrumentation images for each sample. measurement of canal centering ability and canal transportation the image calibration was performed by a digital image processing system (autocad 2014; autodesk inc. san rafael, ca, usa). once the superimposition image was created, the images were opened in the autocad program before starting, used the units of the ruler in the image to convert the measurement to real dimension. measurements were done at the foramen level instead of 1mm from the foramen; measurements were made every one millimeter from d0 to d10 levels d0 to d10 corresponded to the distance (in millimeters) from the apical foramen. level d0 represented the apical foramen; d1to d4 represented the apical curvature, whereas levels d4 to d8 represented the coronal curvature. three measurements were recorded with 0.001mm precision and 600% magnification at each level for a total of 33 measurements per canal. j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 51 figure 3: measurement levels on image in autocad program we measured: (1) the distance between the upper limit of the initial canal and the upper limit of the instrumented canal (xsup), (2) the distance between the inferior limit of the initial canal and the inferior limit of the instrumented canal (xinf), (3) the width of the shaped canal (y) (figure 4). the centering ratio was calculated by the equation: (xsup − xinf )/y and the amount and direction of transportation using the formula: (xsup − xinf) according to the formula, the centering ratio approaches zero as xsup and xinf become closer to the center. the lower the scores, the better are the instruments centered in the canal and less are the canal transportation (16). figure 4: measurement of canals. the data were collected and analyzed by using spss (version 18) for statistical analysis. one way analysis of variance test (anova) was performed to identify the presence of any statistically significant difference among the means of canal centering ability and canal transportation of all groups, at each level at a significance level of 0.05. least significant difference test (lsd) was performed for multiple comparison between groups at different levels. results centering ability: the mean of canal centering ability in (mm) at the different levels of all groups are shown in table (1) and figure (5). table 1: centering ability means and standard deviation at different levels of all groups. (d0 to d10) measure points (in mm from the foramen). d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 d10 protaper mean 0.430 -0.396 -0.627 -0.567 0.275 0.511 0.582 0.427 0.196 -0.109 -0.153 ± sd 0.064 0.057 0.067 0.033 0.029 .078 0.041 0.060 0.028 0.009 0.025 protaper next mean 0.637 -0.181 -0.559 -0.550 0.265 0.478 0.538 0.367 0.168 -0.107 -0.150 ± sd 0.056 0.036 0.068 0.036 0.035 0.052 0.027 0.022 0.018 0.011 0.019 reciproc mean 0.667 -0.175 -0.476 -0.380 0.184 0.489 0.551 0.385 0.181 -0.101 -0.138 ± sd 0.071 0.038 0.053 0.043 0.018 0.075 0.049 0.060 0.020 0.012 0.011 waveone mean 0.658 -0.178 -0.483 -0.394 0.204 0.478 0.564 0.418 0.190 -0.098 -0.137 ± sd 0.115 0.029 0.040 0.051 0.025 0.064 0.042 0.067 0.040 0.005 0.014 figure 5: line chart of centering ability j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 52 note that a negative value indicates that preparation deviated toward the inner aspect of the curve. it can be shown from figure (5) that protaper group has the highest mean values of canal centering ability at almost all levels except at d0. while there were a comparable values of canal centering ability among protapernext, reciproc and waveone group at almost all levels with the better values shown with reciproc and waveone at apical (first) curvature. analysis of variance (anova) test was performed to identify the presence of any statistically significant difference among the means of canal centering ability of all groups, at each level. anova test showed that there was a high significant difference (p < 0.001) among the groups at d0, d1, d2, d3 and d4 and a non significant difference (p > 0.05) among the groups at the other levels. further analysis of all data was needed to examine the difference between each two groups so least significant difference test (lsd) was performed for multiple comparison between groups. by using (lsd) test; at d0 the pt group showed the best centering ability and the difference was a high significant (p < 0.001) with the other groups. -at the other levels the pt showed the least centering ability with a high significant difference with both of the r and wo groups at d0, d1, d2, d3 and d4. -the difference was a high significant between pt and ptn at d0, d1 and a significant difference at d2 and no significant difference at d3 and d4. -at d0, d1 the difference was none significant between ptn and both of the r and wo but a high significant difference was found among them at d2, d3 and d4. at apical curve the r and wo groups showed better centering ability than ptn while at coronal curve the ptn showed better centering ability. -at all levels the difference was non significant between the r and wo groups. canal transportation the results of the descriptive statistics which include the mean and standard deviation (±sd) of canal transportation in (mm) at different levels for all groups are shown in the table (2) and figure (6). protaper group has the highest mean values of canal transportation at almost levels except at d0, while the protapernext exhibited the least mean values at the second (coronal) curvature. reciproc and waveone showed least values at the apical (first) curvature and straight coronal portion. table 2: canal transportation and standard deviation at different levels of all groups. (d0 to d10) measure points (in mm from the foramen). d0 d1 d2 d3 d4 d5 d6 d7 d8 d9 d10 protaper mean 0.233 -0.224 -0.464 -0.394 0.174 0.404 0.503 0.382 0.176 -0.088 -0.133 ± sd 0.033 0.022 0.072 0.064 0.036 0.057 0.049 0.042 0.036 0.0014 0.019 protaper next mean 0.247 -0.086 -0.332 -0.303 0.161 0.314 0.407 0.262 0.96 -0.082 -0.130 ± sd 0.033 0.016 0.043 0.047 0.033 0.026 0.062 0.034 0.013 0.011 0.021 reciproc mean 0.267 -0.082 -0.291 -0.230 0.136 0.399 0.462 0.357 0.157 -0.072 -0.113 ± sd 0.046 0.037 0.051 0.043 0.017 0.065 0.064 0.044 0.032 0.008 0.015 waveone mean 0.267 -0.084 -0.300 -0.235 0.143 0.402 0.501 0.372 0.172 -0.069 -0.114 ± sd 0.023 0.015 0.040 0.042 0.033 0.045 0.035 0.058 0.035 0.011 0.016 figure 6: line chart of canal transportation j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 53 the lowest canal transportation scores were found at points d1, d4 and d9 which corresponded to the straight portion of the canal. the highest ratios were found at points d0, d2, d5 and d6 which corresponded to the foramen and initiating zones of the apical and coronal curvatures. to identify the presence of statistically significant difference among the means of canal transportation of all groups, at each level, analysis of variance (anova) test was performed. there was a high significant difference (p < 0.001) at d1, d2, d3, d5, d6, d7 and d8 and a none significant difference (p > 0.05) at other levels. the least significant difference test (lsd) was performed for multiple comparison between groups. by using (lsd) test, -at d1, d2, and d3 protaper showed the highest canal transportation than the other groups with a high significant difference (p < 0.001) was found among them. -at d2, d3 the ptn showed more canal transportation than both of r and wo with a high significant difference at d3. while at d5, d6, d7 and d8 the ptn showed the best values of canal transportation than the the others with a high significant difference was found among them except at d7 the difference was significant between the ptn and r. -the r and wo showed comparable values of canal transportation at all levels and the difference was none significant between them. discussion one of the chief determinants of quality canal shaping ability of an endodontic instrument is its ability to remain well centered within the root canal space and not make iatrogenic errors such as canal transportation (17). the present study compared the effects of four file systems that have different designs, manufacturing methods, number of files, and kinematics when used to prepare simulated sshaped canal on centering ability and canal transportation. two file systems that were designed for use in rotary instrumentation, and two file systems that have been designed for use in reciprocation instrumentation were used for comparisons. in the present study, the final apical preparation size was 25 for all groups. for singlefile systems, the reciproc r25 file and the waveone primary reciprocating file were selected. these instruments had the same tip size of 25. this was performed in accordance with the recommendation of their manufacturers as these sizes are designated for narrow and curved canals when hand instruments do not passively reach the full working length. whereas protaper and protapernext instruments have various apical sizes with gradual increase, reciproc and waveone have omitted the conventional increments and offer apical widths of apical size 25 and 40, and the risk of transportation always increases in curved canals and with the increase of file size. wider apical preparation might result in some canal straightening and undesirable weakening of the tooth structure, whereas minimal enlargement may leave tissue remnants and infected dentin behind. (18) thus, the reciproc r25 file, the waveone primary reciprocating file, protaper f2, protapernext x2 file were selected for the current study. the centering ratio can explain the ability of files to stay centered in prepared canals calculated by the formula (xsup − xinf )/y , which is more precise than measuring the amount of removed material. actually, most previous studies did not include the final diameter (y) in the calculation, and instead considered only the amount of transportation, according to this formula, the centering ratio reach zero as xsup and xinf come to be closer to the center. the lesser the scores, the superior are the files centered in the root canal(19). regarding canal centering ability, when comparing the ratio at each point in all groups, the 4 niti instrument systems examined had comparable scores in the coronal and middle portion of the canals (d5 to d10) with no statistically significant difference was found at these points; this may be due to that all systems made from niti alloy and the final apical preparation sizes were 25 for all groups. similar findings were found by a study of burklein et al., of curved root canals in extracted teeth in which reciproc, waveone, mtwo, and protaper rotary instruments maintained the original curvature well with no significant differences between the different files( 13). similarly zhao et al., (20) found that pt, ptn and wo have comparable results regarding shaping ability in the coronal and middle portion of the canals in preparation of mandibular first molars. these results also agreed with capar et al (21) whose compared the shaping effects of (oneshape, protaper universal, protaper next, reciproc, twisted file adaptive and waveone primary on centering ability of curved mesial root canals of mandibular molar, and showed that the 6 different file systems produce similar canal centering ability in the preparation of curved mesial canals of mandibular molars. j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 54 the most previous finding showed that most instruments tended to straighten especially the apical curvature of s-shaped canals and is corroborated by several studies (bonaccorso et al.(22); madureira et al., (23). this might be due to that the influence of the coronal curve on the instruments may have declined while progressing coronally owing to the presence of another more apically located curve; this agreed with the present results obtained with pt and ptn but in contrast with results obtained with wo and r in which reciprocating single file showed good shaping effects in apical curve of s-shaped simulated canals. this agreed with (burklein et al., (15); wu et al. (24) the obtained results may be due to the reciprocation motion or the single file used with wo and r. at the level of d0 (apical foramen) the protaper files showed superior centering ability than the protapernext which had comparable scorces with reciproc and waveone. this may be due to use more successive files in protaper system. similar finding was found in the research of göktürk et al. (25), who studied the shaping ability of greater heroshaper, revo-s, protaper universal, mtwo, and race. the heroshaper and revo-s showed lower centering ability than the other groups in simulated curved canals in the apical area. similar results were reported by yoo and cho (26), who compared the shaping ability of reciproc and waveone instruments compared with protaper and profile niti instruments in simulated curved canals indicated that in the groups of reciproc and waveone, the instrument had a tendency to maintain the centering ability better than protaper. this may be attributed to the sharp cutting edges and the multiple tapers along the cutting surface of the protaper files, especially the large increase in taper size from 0.04 to 0.07 (s2 to f1) this may increase the rigidity of the file consequently more resin will be removed from the one side of the canal than the other. additionally the brushing action which is recommended with this system may cause uneven resin removal, these factors may explain relatively low centering ability of this system compared with other niti instruments at these measuring levels. protapernext showed comparable values with both of the two reciprocating groups (waveone and reciproc) and there was no significant difference among them except at d2, d3 and d4 (apical curve) at which the two reciprocating systems produced better centering ability. although at the apical curvature the reciproc and waveone preserved the canal best and showed a better centering ability than ptn; the ptn preserved the coronal curvature best with no significant difference among the groups at this area. this might be due to the taper of ptn varies on a different part of this file or because of the asymmetric motion, which lead to only two edges are in contact with canal wall at time. similar findings were obtained by wu et al. (24) who compared the shaping ability of the protaper universal, waveone and protaper next in simulated l-shaped and s-shaped root canals respectively and showed that ptn could better preserve the coronal curvature than ptu and wo in simulated s-shaped canals. at all measuring levels, there was no significant difference between waveone and reciproc. this agreed with saber et al., (27) compared shaping ability of waveone, reciproc and one shape in severely curved root canals of extracted teeth showed the same finding these results also agreed with burklein et al. (13, 28); capar et al. (29) canal transportation demonstrates the straightening tendency of the file as it prepares the canal. in this study, all tested rotary systems resulted in canal transportation at most examined levels, a finding that is consistent with other studies that showed canal transportation occurs mostly in curved canals at the outer wall of the apical portion of the canal and the inner aspect of the mid-root of the canal (21). the lowest canal transportation was found at points d1, d4 and d9 which corresponded to the straight portion of the canal. the highest ratios were found at points d2, d5, d6 which corresponded to the foramen and initiating zones of the curvature. at apical foramen point (d0) the four groups showed no statistically significant difference among them in canal transportation. this might be because of the noncutting tip design they all possess, which functions only as a guide to allow easy penetration with minimal apical pressure, and the standardized master apical file size, this agreed with hashem et al. (29), whose compared the effect of revo-s, twisted file, profile gt series x and protaper on volumetric changes and transportation of curved root canals, and found that all tested rotary systems produced canal transportation at the apical point in the same manner. similarly at d4, d9, d10 there was no statistically significant difference among the four groups. while there was a high statistically significant difference among the groups at d1, d2, d3, d5, d6 , d7 and d8 these points represent the apical and coronal curvature and probably these differences could be noticed because , at these points of the curvature there is a j bagh college dentistry vol. 28(1), march 2016 a comparative restorative dentistry 55 higher stress on the instrument owing to the critical changes on the relationship of diameter and flexibility this agreed with the study of farah and al-gharrawi (30), in which they found a statistically significant difference among the protaper , biorace and saf groups at level 6 mm. protaper instruments showed the greatest material removal on the inner sides of the apical curvatures and outer side of coronal curvatures, resulting in a marked straightening of the canals, which is in accordance with a recent study of göktürk et al. (25), who restudied the shaping ability of five different systems in s-shaped canals in resin blocks and showed that the protaper instruments have a tendency to straighten both curved parts of the canal this may be due to the protaper universal finishing files have a greater taper at the apical part of the instrument (f1, .07 and f2, .08), leading to increased stiffness or rigidity, similar findings obtained by the protapernext showed the lowest canal transportation scores at the coronal curvature compared with other groups .it may be partly explained by the smaller overall and apical taper of ptn x2 (size 25/.06) compared with ptu f2, reciproc r25 and waveone primary files (all tips are size 25/.08 or this might have been because of the offset asymmetric design. in general, besides the dimension of the instrument, other factors including the instrument design, and the way the instruments are used can influence canal transportation during instrumentation. this observation is in agreement with a previous study of saleh et al. (31), that compared the shaping effects of the f360 and oneshape instruments have a taper of 0.04 and 0.06, respectively, with the 2 reciprocating instruments (i.e., waveone and reciproc) which characterized by a taper of 0.08 over the first 3 mm from the tip in s-shaped canals and found the reciproc and waveone removed more resin compared with f360 and oneshape and that the resulting canal widths were wider after preparation with these reciprocating single files due to these files appear to be less flexible compared with other files. the results of the present study are in agreement with several previous studies like yoo and cho (26) using simulated canals in resin blocks and found that waveone and reciproc produced similar canal straightening and maintained the original canal curvature equally good and better than protaper and profile . also, bürklein et al., (13) reported that waveone, reciproc and oneshape maintained the original curvature of severely curved canals in extracted teeth equally well and produced similar canal transportation. although the difference between wo and r was not large enough to be statistically significant, the r instruments produced less canal transportation than wo at almost levels. their different cross-sectional designs may explain these results. r has a double-cutting edge sshaped geometry, whereas wo has a modified, convex, triangular cross-section with radial lands at the tip and a convex triangular cross-section in the middle and coronal portion of the instrument. references 1. schilder h. cleaning and shaping the root canal. dent clin north am1974; 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41(4): 54852. http://www.dentsplymea.com j bagh college dentistry vol. 30(4), december 2018 the impact of 73 the impact of breastfeeding duration on the development of normal occlusal features of the primary dentition among baghdad preschool children munad jihad al_duliamy b.d.s., m.sc. (1) abstract background: normal occlusal features of primary dentition are crucial for normal development of the permanent dentition. breastfeeding is an important factor for both general and dental health of children. aim: the aim of the present study is to assess the impact of the breastfeeding duration on the prevalence of normal occlusal features of the primary dentition among preschool children in baghdad. materials and methods: the sample was 630 iraqi children (270boys, 360 girls), aged 3-5 years selected from four kindergartens in baghdad city. the study was carried out through questionnaire and clinical examination. normal occlusal features were examined as the presence or absence of interincisive spaces (is) and primate spaces (ps), terminal relationship of the primary second molar that classified as: flush terminal (ft), mesial step (ms) and distal step (ds). the presence or absence of ideal incisor overbite was also recorded. data were statistically analyzed using spss (version 21). chi square and z test were used in data analysis. result:s a significant relation was present between the duration of breastfeeding and the presence of: primate and interincisive spaces, flush terminal plane, mesial terminal plane and ideal incisor overbite. conclusion breastfeeding duration has a positive impact on the development of normal occlusal features of the primary dentition. efforts should be taken to enhance the knowledge of the community, especially the mothers, about this impact to encourage them to practice exclusive breastfeeding for more than 12 months. keywords: breastfeeding, normal occlusal features, primary dentition, children health. (received: 19/7/2018; accepted: 6/8/2018) introduction more than 14 centuries ago, al-quran was sent down by almighty allah for the whole humanity to regulate almost all human’s life issues (1). quran and hadiths stated the values of breastfeeding and the regulations of breastfeeding were discussed in fourteen times in eight verses of seven suras (al-baqarah 234, al-nesa 24, al-hajj 3, alqasas 8,13, luqman 15, al-ahqaf 16 and al-talaq7) in the holy quran which emphasizes the importance of breastfeeding for humans(2). breastfeeding duration of the child had been the matter of a great deal of scientific interest, such as its effect on the subsequent cognition development (3). its role in the educational, mental, psychomotor and neuropsychological performance was studied by julvezi et al (4), while its impact on the behavioral functioning of the child had been shown by oddy et al.(5). for the child, there was some evidence that breastfeeding had a protective effect against asthma (6) as well as an effect in reducing neonatal mortality and morbidity (7). however, for the mothers it had a protective role against breast and ovarian carcinoma(8) . these features of primary teeth directly influences the development of the permanent dentition. ____________________________________________________ (1) lecturer at department of pop, college of dentistry, almustansiria university breastfeeding is beyond just nutrition; it is a crucial and fundamental factor for the proper growth and development of the body as well as the stomatognathic and orofacial musculature. therefore, "breastfeeding is the best orthopedic appliance one can offer to get an adult’s face in terms of harmonious development, which is imperative for the good development of the entire craniofacial complex during the most important period of the newborn life"(9). primary teeth largely affect the growth and development of a child dentition. it plays critical role in esthetics, eating, speech, encourage normal function and growth. primary teeth ensure the eruption of permanent successors in their position and time(10). therefore, development of normal occlusion is essential for good general health (11). four features found in primary dentition, can indicate good dental development, had been described as features of "normal" occlusion of the primary dentition. they are: spacing of the incisors, presence of "primate spaces", existence of a deep incisor overbite, and the relationship of the distal surface of the upper and lower second primary molars (terminal plane) (12). the relation between the distal surfaces of the maxillary and mandibular second primary molars is one of the most important factors that influence the future occlusion of the permanent dentition (13). flush or mesial step is molar relation that is more favorable in the primary dentition as it reduces the chances of malocclusion in the j bagh college dentistry vol. 30(4), december 2018 the impact of 73 permanent dentition. however, distal step molar relation in the primary dentition led to class ii molar relation in the permanent dentition cannot be redressed with the growth of the child (14). spacing often presents between all primary anterior teeth. the most obvious spaces is that present mesial to canines in the maxilla and distal to canines in the mandible which are termed as primate or anthropoid spaces. another form of space in the primary dentition is the secondary or developmental spaces, which are usually found between the incisors. such dental spaces are termed “physiological spaces.” these spaces are significant later on for the correct alignment during the eruption of the permanent teeth and the settlement of occlusion. absence of these spaces in the primary dentition (non-spaced dentition) is an indication for the disharmony between jaw/tooth size (15). the presence of incisal overbite is considered as one of the characteristics for normal occlusion in the primary dentition (16). the purpose of the present study, which was done in baghdad city the capital of iraq, was to assess the impact of the of breastfeeding duration on the prevalence of these occlusal features in the primary teeth among the preschool children and furthermore to investigate their family's knowledge toward this impact. materials and methods the scientific committee of research and development in college of dentistry / al mustansiriyha university approved the research protocol of the present study. so it was conducted among a sample consisted of 630 iraqi children (270 boys, 360 girls) their age ranged between 3-5 years, randomly selected from four kindergartens in baghdad city. a cross-sectional study was conducted through a clinical examination to the children and questionnaire to their parents. the questionnaires were sent through the principals to the child’ mothers to get a signed parental consent for the child’s participation. the questionnaire contained information regarding the child’s name, sex, age, history of systemic disease, history and duration of the child feeding whether it was breast /bottlefeeding, history of thumb or dummy sucking. moreover, the mothers asked in the questionnaire if they had any a knowledge concerning the relation between breastfeeding and the development of normal occlusion. children included in this study should had the following criteria: 1. no history of any systemic disease nor a history of bad habit (thumb sucking, pacifier (dummy) sucking, nail biting, and mouth breathing) or a history of previous orthodontic treatment. 2. children should had a complete intact set of primary teeth (without damaged due to caries or fracture) with symmetrical terminal plane in both sides. the duration of breastfeeding defined as "the number of months elapsed between birth and the termination of breastfeeding, regardless of whether the child was fed any other solids or liquids during this period" (17). for statistical analysis purposes, duration of breastfeeding was categorized as: never breastfed, 0-6 months, 0-12 months and more than12 months. the clinical examination was performed for all children in their kindergarten premises while seated in front of the examiner (a single orthodontist who was blind to the child’s questionnaire data) under natural light, using disposable gloves, mask, and cheek retractor. the intraexaminer calibration was done by having twice examination for 20 children for two-day intervals by the same examiner. there was complete agreement for all parameters using kappa statistic. the following parameters were evaluated during the assessment of occlusion while the jaws in centric occlusion: incisors spaces (is): spaces between incisors of maxillary and mandibular arches. primate spaces (ps): in the maxilla, it presents between the lateral incisor and canine. in the mandible, it presents between the primary canine and first primary molar, incisors spaces (is) and primate spaces (ps) in both maxillary and mandibular arches were recorded as spacing present or spacing absent according to facal-garcia et al. (18). molar relationship was evaluated according to the criteria used by abualhaija and qudeimat (19) and recorded as present for each of the followings: surfaces of the upper and lower second primary molars were in the same vertical plane when the jaws were in centric occlusion. surfaces of the lower primary second molar present in posterior relationship to the distal surface of the upper second molars when the jaws were in centric occlusion. resent when the jaws were in centric occlusion and if the distal surfaces of the lower primary second molar occurred in anterior relationship to the distal surface of the upper second molars deep incisor overbite were assessed as present ,when the incisal tips of the primary lower central incisors contacting the palatal surfaces of the upper primary central incisors j bagh college dentistry vol. 30(4), december 2018 the impact of 73 when the jaws were in centric occlusion, or absent according to the ideal overbite recommended by abualhaija and qudeimat (19). the collected data was transferred into the computer using excel 2010 after which it was subjected to statistical analysis using spss version 21 and analyzed using chi square and z score tests. results feedback from only 572 questionnaires was obtained, as 58 questionnaires were never returned, so that only 422 child (251 boys, 171 girls) were included as the other 150 children were excluded because they were not met the inclusion criteria. distribution of the sample according to gender and duration of breastfeeding was shown in table 1. spaces is and ps (table 2,3,4) among children who breastfeed for more than 12 months the interincisive spaces present in very highly significant value in both maxillary (75.25%) and mandibular (76.24 %) arches. the lowest values of is in both maxillary (21.42 %) and mandibular (0%) arches were present among children who never breastfeed. also the highest ps values were present among children who breastfeed for more than 12 months in both maxillary (80.2%) and mandibular (67.33%) arches. again the lowest values of ps in both maxillary (14.29%) and mandibular (0%) arches were present among children who never breastfeed. there were highly significant differences in the presence of is between maxillary (52.13 %) and mandibular arches (38.86 %). there was highly significant differences in ps values between maxillary (63.74%) and mandibulsar arches (43.37%). regarding gender differences of is and ps, the only significantly high value was present in ps within the maxillary arch of male (70.12%). otherwise there were no gender significant differences in the is values of both maxillary and mandibular arches and ps values of mandibular arches. terminal plane (table 5 and 6) there were significantly high relation between the duration of breastfeeding and the terminal plane relations. flush terminal plan relation present in 64.36 % and mesial step relation in 30.69% among children who breastfeed for more than 12 months. while there was a significantly highly (71.43 %) presence of distal step terminal relation among children who never breastfeed. there were gender differences in terminal plane relations in both flush terminal plane relations (57.37 % for boys and 35.67 % for girls) and distal step (16.34 % for boys and 38.01 % for for girls). a mesial step were present with no significant differences (26.30 % for boys and 26.32% for girls). overbit (table 7,8) regarding the presence of ideal overbite, a higher percentage of the presence of ideal overbite was present among children who were breastfed more than 12 months in both boys (77.94%) and girls (90.91 %) while the lowest percentage of it was present among children who were never breastfed which was (0 %) for both boys and girls. on the other hand, there were no significant differences in the presence of ideal overbite ( 63.347 % for boys and 70.175 % for girls) among boys and girls (table 8). mother's knowledge regarding the impact of breastfeeding on the occlusion (figure 1) regarding the level of mother’s knowledge about the impact of breastfeeding on the development of normal occlusion, feedback from all the returned questionnaires (572) were statistically analyzed and the results showed that 66 % of mothers had no knowledge about the association of breastfeeding and the occlusal development which mean that they had low level of knowledge. j bagh college dentistry vol. 30(4), december 2018 the impact of 04 table 1: distribution of the sample according to gender and duration of breastfeeding. table 2: the relation between the duration of breast feeding and the presence of is and ps in both maxillary and mandibular arches n = 422 , is = incisal space, ps = primate space table 3: differences in the presence of is and ps between arches table 4: gender differences in the presence of is and ps in both maxillary and mandibular arches girls boys total duration of breast feeding 6 8 14 no breastfeed 48 58 106 0-6 months 129 72 201 6-12 months 68 33 101 more than 12 months 251 171 422 total type of space duration max % mand % is no breastfeed 21.42 0 0-6 months 33.02 16.04 6-12 months 52.54 34.83 more than 12 months 75.25 76.24 p value 0.001 0.001 ps no breastfeed 14.29 0 0-6 months 46.22 22.64 6-12 months 68.16 45.27 more than 12 months 80.2 67.33 p value 0.001 0.001 sp sp hcra ton present ton present 36.26% 153 63.74% 269 47.87% 202 52.13% 220 max. 56.63% 239 43.37% 183 61.14% 258 38.86% 164 mand. n = 422 p v =0.001 n = 422 p v =0.001 sp sp gender arch ton present ton present 29.88% 75 70.12% 176 47.81% 120 52.19% 131 boys (251) max. 45.61% 78 54.39% 93 47.95% 82 52.05% 89 girls (171) pv= 0.001 pv= 0.977 56.57% 142 43.43% 109 58.96% 148 41.04% 103 boys (251) mand. 56.72% 97 43.28% 74 64.33% 110 35.67% 61 girls (171) pv= 0.975 pv= 0.267 j bagh college dentistry vol. 30(4), december 2018 the impact of 04 table 5: the relation of breastfeeding duration and the presence of terminal plane relations types table 6: gender differences in the presence of different types of terminal plane relations. table 7: the association between the duration of breast feeding and the presence of ideal primary dentition overbite duration boys girls present not total present not total n % n % n % n % 0 0 0 6 100 6 0 0 8 100 8 1 27 56.25 21 43.75 48 30 51.72 28 48.28 58 2 79 61.24 50 38.76 129 60 83.33 12 16.67 72 3 53 77.94 15 22.06 68 30 90.91 3 9.09 33 pv = 0.001 pv = 0.001 table 8: gender differences in the presence of primary dentition ideal over bite terminal plane duration of breastfeeding present(n) % not (n) % p v ft no breastfeed n=14 1 7.14 13 92.86 0.001 0-6 months n=106 33 31.13 73 68.87 6-12 months n=201 106 52.74 95 47.26 more than12 months n=101 65 64.36 36 35.64 ds no breastfeed n=14 10 71.43 4 28.57 0.001 0-6 months n=106 56 52.83 50 47.17 6-12 months n=201 35 17.41 166 82.59 more than12 months n=101 5 4.95 96 95.05 ms no breastfeed n=14 3 21.43 11 78.57 0.041 0-6 months n=106 17 16.04 89 83.96 6-12 months n=201 60 29.85 141 70.15 more than12 months n=101 31 30.69 70 69.31 p value girls (171) boys (251) terminal plane relations 0.001 35.67 % 57.37 % ft 0.996 26.316 % 26.295 % ms 0.001 38.012 % 16.335 % ds presence of ideal overbite p value girls (171) boys (251) 0.146 70.175 % 63.347 % j bagh college dentistry vol. 30(4), december 2018 the impact of 04 figure 1: the level of mother's knowledge regarding the impact of breastfeeding on the occlusion (n=572) discussion ''childhood is the mirror that reflects the propensity of adulthood'' (13). hence, perfect permanent dentition is the sequela of ideal primary dentition. a vast number of studies confirmed the relationships between duration of breastfeeding and the occurrence of malocclusion among different age groups (20). one of the diminished islamic teachings is the breastfeeding practice. it is advisable to return it back. the present study aimed to assess the relation between the duration of breastfeeding and the development of normal occlusal features in the primary dentition among preschool children as well as to determine the level of knowledge about this relation among their mothers in baghdad city. spaces (is, ps) according to the findings of the present study, highly significant difference was found between the duration of breastfeeding and the presence of is and ps spaces in both maxillary and mandibular arches. the presence of is and ps spaces were greater in both of the maxillary and mandibular arches among children who breastfed more than 12 months (longer duration), however, the lowest percentage for the present of these spaces were found among children who were never breastfed. these findings came in accordance with that found by other researchers who concluded that a short duration of breast-feeding was directly associated with space deficiency (21,22). on the other hand, the higher frequency of both interincisive and primate spaces was significantly present in the maxillary arch. this in agreement with the result of im et al (23) who showed that the frequency of spacing in primary dentition was greater in the maxilla than in the mandible. regarding gender differences, the present study showed that there was a statistical difference concerning the present of the ps value in the maxillary arches among boys (70.12%) which was in agreement with the result of joshi and makhija (24) who found that the amount of spacing was greater among boys. terminal plane the present study showed that long duration of breastfeeding was significantly related to the higher frequency of flush terminal and mesial step terminal planes relationships (64.36 %, 30.69 % respectively). on the other hand, short duration of breastfeeding was associated with high frequency of distal step terminal plane (71.43 %). these findings confirmed by that reported by nahásscocate et al.(25) who demonstrated the association between longer periods of breastfeeding and lower prevalence of distal step. however, agarwal et al. (26) found no statistical significant association concerning the distal step terminal plane frequency among 195, 34% 377, 66% mothers with knowledge mothers with no knowledge j bagh college dentistry vol. 30(4), december 2018 the impact of 07 children who were breastfed ≤6 months and ≥6 months which could be due to the differences between the present study and the past one in the sample size, age of children and methods by which the study was carried out. in regards to gender, there was a significant difference in the prevalence of flush terminal and distal step with no differences in the prevalence of mesial step. these findings were in agreement with that found by vegesna et al. (16) and fernandes et al.(27) . overbite in this study, the presence of ideal overbite presented with a highly significant difference among children who were breastfed more than 12 months for both boys (77.94 %) and girls (90.91 %). this can be explained according to romero et al. (28) who suggested that long duration of breastfeeding could enhance proper tongue position and nose breathing that in turn apply a positive impact on the development of overbite. there were no significant gender differences in the presence of ideal overbite. this agree with the result of vegesna et al. (16) who found that no significance with regard to overbite in primary dentition. mother knowledge regarding the impact of breastfeeding on the occlusion according to the findings of the present study, there was low level of knowledge about the impact of duration of breastfeeding on the development of normal occlusion among the mothers, children. this may be explained by the shortage of the dental health education so it is important to engage the community to increase the knowledge about the importance of breastfeeding duration to the dental health and occlusion. conclusion there is strong relationship between the duration of exclusive breastfeeding and the prevalence of normal occlusal features of primary dentition. therefore, exclusive breastfeeding for more than 12 months is considered as an early component of preventive orthodontics for developing normal primary dentition. the author feel that there is a need to develop a strategic plan by dental government organization for promoting breastfeeding through media, campaign and support theme by the instructions and guidance from the holy quran, hadiths and evidence based dentistry. it is the responsibility of dental academics to develop educational programs to aware mothers, girls, and the entire community about the importance of breastfeeding in the development of normal occlusion as a part of the third mission of university (community service). references 1 mohamad m z, ibrahim b, yusof s, salleh aw. factors of the rise and fall of human civilization based on the perspective of alquran. advances in natural and applied sciences. 2013; 7(2): 164-172. 2 maulawi s a. the holy quran-arabic text and english translation. 14th ed. islam international publications ltd (4002.) 3 horta b, victora c. the short-term effects of breastfeeding: a systematic review. geneva, switzerland: world health organization: geneva: 2013. 4 julvez j, alvarez-pedrerol m, rebagliato m, murcia m, forns j, garcia-esteban r, et al. thyroxine levels during pregnancy in healthy women and early child neurodevelopment. epidemiology 2013; 24:150-157. 5 oddy w, li j, robinson m, whitehouse a. the long-term effects of breastfeeding on development. intech, shanghai, china; 2012 6 lodge c j. tan d j, lau m , dai x, tham r , lowe a.j. , et al. breastfeeding and asthma and allergies: a systematic review and meta-analysis. acta paediatr suppl 2015; 104: 38-53. 7 chowdhury r, sinha b, sankar mj, taneja s, bhandari n, rollins n, et al. breastfeeding and maternal health outcomes: a systematic review and meta-analysis. acta paediatr 2015; 104 (467): 96– 113. 8 khan j, vesel l, bahl r, martines j c. timing of breastfeeding initiation and exclusivity of breastfeeding during the first month of life: effects on neonatal mortality and morbidity-a systematic review and meta-analysis. matern child health j 2014, 19 (3): 468-479. 9 rochelle imf, tagliaferro eps, pereira ac, meneghim mc, nóbilo ka, bovi ambrosano gm. breastfeeding, deleterious oral habits and malocclusion in 5‐year‐old children in são pedro, sp, brazil. dental press j orthod. 2010; 15: 71–81. 10 bijoor r r, kohli k. contemporary space maintenance for the pediatric patient. n y state dent j 2005; 71(2):32-5. 11 moon h j, lee y k. the relationship between dental occlusion/ temporomandibular joint status and general body health: part 1. dental occlusion and tmj status exert an influence on general body health. j altern complement med 2011; 17(11):995–1000. 12 penido r s, carrel r, chialastri, a j et al. occlusal assessment of a 3-5 year population. pediatr dent 1979; 1(2): 104-108. 13 sriram c h, priya v k, sivakumar n, reddy k r, babu p j, reddy p. occlusion of primary dentition in preschool children of chennai and hyderabad: a comparative study. contemp clin dent 2012; 3:31– 7. 14 bishara s e, hoppins b j, jakobson j r, kohout f j. changes in the molar relationship between the deciduous and permanent dentitions: a longitudinal study. am j orthod dentofacial orthop 1988; 93(1):19–28. j bagh college dentistry vol. 30(4), december 2018 the impact of 00 15 baume l j. “physiological tooth migration and its significance for the development of occlusion. i. the biogenetic course of the deciduous dentition,” journal of dental research 1950; 29(2):123–132. 16 vegesna m, chandrasekhar r, chandrappa v. occlusal characteristics and spacing in primary dentition: a gender comparative cross-sectional study. int sch res notices 2014; 2014:512680. 17 caramez da silva f.; justo giugliani, e r.; capsi pires, s. duration of breastfeeding and distoclusion in the deciduous dentition. breastfeed. med. 2012; 7: 464–468. 18 facal-garcía m, suárez-quintanilla d, de novagarcía j. diastemas in primary dentition and their relationships to sex, age and dental occlusion. eur j paediatr dent. 2002; 3(2):85-90. 19 abu alhaija e sj , qudeimat m a. occlusion and tooth/arch dimension in primary dentition of preschool jordanian children. int j paediatr dent. 2003; 13:230–239. 20 montserrat boronat-catalá, josé maría montielcompany, carlos bellot-arcís, josé manuel almerich-silla , montserrat catalá-pizarro. association between duration of breastfeeding and malocclusions in primary and mixed dentition: a systematic review and meta-analysis. scientific reports. 2017; 7: 5048 | doi:10.1038/s41598-01705393-y. 21 lopez del valle l m, singh g d, feliciano n, machuca m del c. associations between a history of breastfeeding, malocclusion and para functional habits in puerto rican children. pr health sci j 2006; 25(1):31–34. 22 chen x, xi b, ge l. effects of breast-feeding duration, bottle-feeding duration and non-nutritive sucking habits on the occlusal characteristics of primary dentition. *bmc pediatrics 2015; 15:46. 23 im d h, kim t w, nahm d s, chang y i. spacing and crowding of the primary dentition in korean children–relationship to tooth sizes and dental arch dimension. korean j orthod 2006; 36(1):84–90. 24 joshi m r, makhija p g. some observations on spacing in the normal deciduous dentition of 100 indian children from gujarat. br j orthod 1984; 11(2):75–79. 25 nahás-scocate a c r, de moura p x, marinho r b, alves a p, ferreira r i, guimarães f m. association between infant feeding duration and the terminal relationships of the primary second molars. braz. j. oral sci. 2011; 10(2): 140-145. 26 agarwal s s, sharma m, nehra k, jayan b, poonia a, bhattal h. validation of association between breastfeeding duration, facial profile, occlusion, and spacing: a cross-sectional study. int j clin pediatr dent 2016; 9(2):162-166. 27 fernandes s, gordhanbhai patel d, ranadheer e, kalgudi j, santokì j, chaudhary s. occlusal traits of primary dentition among pre-school children of mehsana district, north gujarat, india. journal of clinical and diagnostic research 2017; 11(1): zc92-zc96. 28 romero c, scavone-junior h, garib d, cotrimferreira f, ferreira r: breastfeeding and nonnutritive sucking patterns related to the prevalence of anterior open bite in primary dentition. j appl oral sci 2011, 19 (2):161-168 المستخلص األسنان لصحة المهمة العوامل من الطبيعية الرضاعة تعد كما. الدائمة لألسنان الطبيعي للنمو ضرورية اللبنية لألسنان الطبيعية اإلطباق سمات تعتبر: البحث خلفية لدى اللبنية األسنان في الطبيعية اإلطباقية السمات انتشار على الطبيعية الرضاعة مدة تأثير تقييم ھو الدراسة ھذه من الهدف: البحث اھداف. للطفل العامة والصحة سنوات 5-3 بين أعمارھم تراوحت ،(أناث 300 ذكور، 470) عراقياا طفلا 030 العينة بلغت: والطرق المواد. بغداد مدينة في المدرسة قبل ما مرحلة في األطفال غياب أو كوجود اإلطباقية الخصائص فحص تم حيث السريري والفحص االستبيان خلل من الدراسة أجريت وقد. بغداد مدينة في أطفال رياض أربعة ضمن تم ذلك وبعد. المثالية العظة وجود عدم أو ووجود والسفلي العلوي الفكين في النهائية اللبنية الطواحن ألطباق الطبيعية العلقات وجود ومدى األسنان، بين المسافات نتائج اظهرت: النتائج. البيانات تحليل في z واختبار chi مربع استخدام وتم(. 42 اإلصدار) االجتماعية للعلوم اإلحصائية الحزمة بواسطة إحصائيا البيانات تحليل بين اللبنية النهائية الطواحن الطباق الطبيعية العلقات ووجود القواطع بين المسافات ووجود الطبيعية الرضاعة مدة بين إحصائية داللة ذات علقة وجود الدراسة . اللبنية لألسنان الطبيعية اإلطباق ميزات تطوير على إيجابي تأثير لها الطبيعية الرضاعة فترة: االستنتاجات. المثالية العظة وجود وكذلك والسفلي العلوي الفكين .شهر عشر اثني من ألكثر الحصرية الطبيعية الرضاعة ممارسة على لتشجيعهن التأثير ھذا حول األمهات، وخاصة المجتمع، معرفة لتعزيز الجهود بذل يجب j bagh college dentistry vol. 29(4), december 2017 oral health status among pedodontics, orthodontics and preventive dentistry 102 oral health status in relation to nutritional status among institutionalized and non-institutionalized orphans in baghdad city aseel m.abdul majeed, b.d.s.(1) zainab a. a. al-dahan, b.d.s., m.sc.(2) abstract background: nutritional condition was reported as one of the factors affecting the oral health status, particularly among underprivileged groups. orphans are one of the known high-risk groups. the aims of this study were to assess the nutritional status of orphans, and its impact on the oral health status. materials and methods: five-hundred children aged 6-12 years old, 254 males and 246 females: institutionalized, noninstitutionalized orphans and controls were participated in this study. nutritional status assessed according to body mass index (bmi). ramfjord index teeth were examined to assess oral cleanliness and gingival condition. all data were analyzed using spss version 23. results this study revealed the institutionalized orphans with low mean value of bmi, significant differ than noninstitutionalized orphans and highly significant than controls, whereas the non-institutionalized orphans was significantly differ than controls. each of institutionalized and non-institutionalized orphans was with highly significant elevated mean plaque and gingival indices than control, while significant high mean rank calculus index for noninstitutionalized orphans than each of institutionalized orphans and controls was found. according to bmi indicators of both orphan groups, it was found that thinness group among institutionalized orphans with significant elevated mean plaque index; however, high non-significant values for gingival and calculus indices were found among thinness grades. conclusion: this study reflected that nutritional status is a relative factor; may affect the oral cleanliness and gingival health. moreover, oral hygiene and preventive care are mandatory, should be stressed through dental care programs. keywords: orphans, oral health, nutrition. plaque index. (j bagh coll dentistry 2017; 29(4): 102-109) introduction orphan is a child under the age of 17 years, orphaned either due to death or loss of parents, or neglected or abandoned by parents or whose parents are no longer fulfilling any of their parental duties (1). in iraq, orphans are almost 4.5 million due to violence, conflict and displacement happened after 2003, and this number increases each and every day (2). thus, they are considered as socially and financially handicapped (3), as parents are not available to help and protect them. the vast majority of orphans either living with a surviving parent grandparent or other family member, or residing in orphanages(4). oral health is a basic human right and critical to general health and wellbeing. malnutrition affects the oral health and a poor oral health in turn, may lead to malnutrition (5). plaque is a soft none mineralized, microbial aggregation on the teeth and other solid structures in the mouth, pale yellow in color (6). plaque is a major causative factor in gingival and periodontal disease and a contributory factor in dental caries. if plaque is not removed, mineralization within plaque will happened and cause calculus. (1) master student, department of pedodontic dentistry, college of dentistry, university of baghdad. (2) professor, department of pedodontic dentistry, college of dentistry, university of baghdad. calculus is an important factor in the development of gingival and periodontal diseases. it is classified as supra gingival or sub gingival. gross accumulations of calculus are occasionally seen in teenaged and pre teenaged children (7). gingivitis is an inflammatory disease restricted to the gingival soft tissues, with no loss of alveolar bone or apical migration of the periodontal ligament along the root surface; it is common in children (8, 9). the primary cause is dental plaque related to poor oral hygiene. inadequate oral hygiene is the most important risk factor in the development of periodontal disease. gingivitis progress more rapidly in undernourished populations (10). several iraqi studies revealed that nutritional status may affect the oral health among children of different age groups and geographical locations (11-19). this study was carried out in baghdad city because no previous studies were conducted to describe the oral health status in relation to nutritional status of orphan children living under institutionalized care compared to non-institutionalized orphan children and control group. subjects and methods the sample size comprised of 500 children aged 6 to 12 years, included institutionalized orphans (123 children; 57 girls and 66 boys), j bagh college dentistry vol. 29(4), december 2017 oral health status among pedodontics, orthodontics and preventive dentistry 103 represent the first study group, noninstitutionalized orphans living with their relatives, matching with age and gender with the institutionalized ones (127 children; 66 girls and 61 boys), represent the second study group, and children matching with age and gender, living with their parents, examined in schools of same geographic area (250 children; 123 girls and 127 boys), represent the control group. permission was obtained from the ministry of labor and social affairs and baghdad educational institutions in order to meet subjects with no obligation, the purpose of the study was explained to the institutions and schools authorities to ensure full cooperation, also special consents were distributed to parents to obtain permission for including their children in the study. children without permission from their parents, with serious systemic diseases, wearing orthodontic appliances, and/or uncooperative were not examined. questionnaire about the brushing frequency during the day was, applied for each child separately. body mass index (bmi) reflected the nutritional status of the sample, it is a number calculated from child's weight and height name as anthropometric measurement (20). the height of the participants was measured in centimeters, using an ordinary measuring tape installed vertically, while weight was assessed in kilograms using a mechanical scale. the bmi was calculated as the ratio of the subject's body weight (in kg) to the square of their height (in meters), according to this formula; bodyweight / (height)2=bmi (kg)/m2 bmi-for-age should be presented in z-scores based on the who growth reference (gr) 2007 for children 5-19 years. categories were defined: severe thinness (bmi <-3sd), thinness (bmi≥ -3 sd&< -2 sd), acceptable (normal weight) (bmi−2sd to +1sd), overweight (bmi>+1sd & ≤+2 sd) obesity (bm >+2sd) (21). dental plaque was assessed by using plaque index (pll) of silness and loe (22), gingival health condition (gi) was assessed by loe and silness (23), calculus (cali) was scored utilizing the criteria set by ramfjord. ramfjord index teeth were examined to represent the whole dentition (24).the severity of oral hygiene was assessed according to the classification introduced by loe and silness (23) in to negative (zero state), mild, moderate and severe condition. statistics: statistical analyses were computer assisted using spss version 23 (statistical package for social sciences) in association with microsoft excel 2013. the statistical tests used are: independent samples t-test, anova, bonferonni t-test, kruskal-wallis test, mann-whitney test and chisquare (2) test. p-values less than 0.05 were considered as statistically significant and p values that less than 0.001 were regarded as highly significant. results table (1) illustrates the distribution of the total sample according to age, gender, and bmi. the distribution according to age group was divided into four groups (6-7) years old, (8-9), (10-11) and (12) years old. gender was distributed as males represent highest than females, the distribution according to the bmi: the majority of the children were under the category of acceptable weight. figure (1) illustrates the nutritional status of children by bmi indicator grades. the mean±se bmi for institutionalized orphans (-0.45±0.088) was significantly lower than non-institutionalized orphans (-0.03±0.11, p=0.037) and highly significant lowered than controls (+0.41±0.093, p<0.001), while the mean bmi for noninstitutionalized orphans was significantly lower compared to controls with p=0.007. table (2) shows different and comparable percentages of teeth brushing experience among the three groups, but with no significant difference. table (3) shows the distribution of sample according to severity of pli, gi, and cali, in the present study divided in to negative, mild and moderate conditions, the major prevalence of pli and gi was of mild type, in regard to calculus, the negatively score was the major percentage. figure (2) illustrated the high significant difference in pli among the groups (p<0.001), with mean±se values of pli of institutionalized (0.67±0.03) and noninstitutionalized orphans (0.68±0.026) they were highly significant elevated than that of controls (0.54±0.016) with p<0.001 for each. however, there was no significant difference between institutionalized and noninstitutionalized orphans in pli. similarly, figure (3) showed the high significant difference in gi among the groups (p<0.001), the mean±se values of gi of each institutionalized (0.52±0.022) and non-institutionalized orphans (0.53±0.022) had highly significant increase in comparison with that of controls (0.39±0.012) with p<0.001 for both.whereas there was no significant difference between institutionalized and noninstitutionalized orphans regarding gi. considering cali among the 3 groups, significant high mean rank value was found among non-institutionalized orphans (270.9) j bagh college dentistry vol. 29(4), december 2017 oral health status among pedodontics, orthodontics and preventive dentistry 104 compared to each of institutionalized orphans (242.1, p=0.011) and controls (244.3, p=0.004), while non-significant difference between institutionalized orphans and controls was found, as shown in table (4). table (5) demonstrates the mean values of plaque and gingival indices among different bmi grades, a higher mean values of plaque and gingival indices were recorded among thinness than other grades; the mean pli with significant high value in thinness group of (0.96±0.126, p=0.028) with significant negative relation with bmi (r=-0.199 p=0.027) for institutionalized orphans, while non significant zero linear relation was found for non-institutionalized orphans with high mean rank in thinness group. considering the mean gi, there was non significant negative linear relation with bmi among both institutionalized and non-institutionalized orphans with high mean in thinness group. however, table (6) shows high cali mean rank but with non-significant was found among thinness group of both institutionalized and noninstitutionalized orphans with no significant linear correlation with bmi, positive for institutionalized and negative for noninstitutionalized orphans. table 1: distribution of the sample by age, gender and bmi for age z score-categories among the groups. institutionalized orphans non-institutionalized orphans controls n % n % n % a g e g r o u p (y e a r s) (6-7) 34 27.6 27 21.3 61 24.4 (8-9) 32 26.0 35 27.6 67 26.8 (10-11) 41 33.3 44 34.6 85 34.0 12 16 13.0 21 16.5 37 14.8 total 123 100.0 127 100.0 250 100.0 mean+ se 9.11±0.178 9.37±0.173 9.24±0.124 g e n d e r n % n % n % males 66 53.7 61 48.0 127 50.8 females 57 46.3 66 52.0 123 49.2 total 123 100.0 127 100.0 250 100.0 b m i thinness 6 4.9 8 6.3 7 2.8 acceptable 117 95.1 114 89.8 205 82.0 overweight/obese 0 0.0 5 3.9 38 15.2 total 123 100.0 127 100.0 250 100.0 figure 1: dot diagram with error bars showing the difference among the 3 groups in mean (with its 95% confidence interval) bmi. j bagh college dentistry vol. 29(4), december 2017 oral health status among pedodontics, orthodontics and preventive dentistry 105 table 2: differences in teeth brushing frequency /day among the groups. frequency of teeth brushing / day institutionalized orphans non-institutionalized orphans controls p n % n % n % 1 36 30.0 6 8.7 57 24.6 0.43[ns] 2 26 21.7 31 44.9 74 31.9 3 31 25.8 18 26.1 50 21.6 4 (irregular) 27 22.5 14 20.3 51 22.0 total 120 100.0 69 100.0 232 100.0 mean rank 207.6 227.7 207.8 no significant p>0.05. table 3: distribution of sample according to the severity of plaque, gingivitis and calculus. parameters institutionalized orphans non -institutionalized orphans controls n % n % n % p l i negative (zero) 0 0.0 3 2.4 0 0.0 mild (<=1) 102 82.9 106 83.5 237 94.8 moderate (1.1-2) 21 17.1 18 14.2 13 5.2 total 123 100.0 127 100.0 250 100.0 g i negative (zero) 1 0.8 3 2.4 5 2.0 mild (<=1) 119 96.7 122 96.1 243 97.2 moderate (1.1-2) 3 2.4 2 1.6 2 0.8 total 123 100.0 127 100.0 250 100.0 c a l i negative (zero) 112 91.1 101 79.5 225 90.0 mild (<=1) 11 8.9 26 20.5 25 10.0 total 123 100.0 127 100.0 250 100.0 figure 2: dot diagram with error bars showing the difference among the 3 groups in mean (with its 95% confidence interval) pli. figure 3: dot diagram with error bars showing the difference among the 3 groups in mean (with its 95% confidence interval) gi. j bagh college dentistry vol. 29(4), december 2017 oral health status among pedodontics, orthodontics and preventive dentistry 106 table 4: difference in cali (median and mean rank) among the groups. cali institutionalized orphans non-institutionalized orphans controls p median mean rank median mean rank median mean rank 0.006* 0 242.1* 0 270.9* 0 244.3 *significant p<0.05. table 5: the difference in mean pli and gi among bmi for age z score groups of institutionalized and non-institutionalized orphans. plaque index gingival index bmi groups institutionalized orphans non-institutionalized orphans institutionalized orphans non-institutionalized orphans mean± se mean± se mean± se mean± se thinness 0.96±0.126 0.73±0.153 0.68±0.105 0.6±0.108 acceptable 0.66±0.031 0.68±0.027 0.52±0.022 0.52±0.023 overweight / obese 0.56±0.065 0.43±0.078 difference 0.028* 0.58[ns] 0.11[ns] 0.52[ns] r=-0.199, p=0.027* r=0, p=1[ns] r=-0.114, p=0.21[ns] r=-0.089, p=0.32[ns] * significant p<0.05. table 6: difference in cali (median and mean rank) among bmi groups of institutionalized and non institutionalized orphans. bmi groups institutionalized orphans non-institutionalized orphans median mean rank median mean rank thinness 0 67.3 0 67.6 acceptable 0 61.7 0 63.8 overweight / obese 0 62.1 difference 0.45[ns] 0.91[ns] r=0.061,p=0.5[ns] r=-0.014,p=0.87[ns] * significant p<0.05, ** highly significant p<0.001. discussion the present study was conducted to reveal the oral health status among institutionalized and noninstitutionalized orphans. orphan's children represent a high risk group of disadvantaged children as they lack basic information, motivation, and supervision provided by parents, especially in the beginning of their childhood. moreover, they may be neglected or abused in the latter half of childhood by relatives and/or society (25). therefore comparison with the general population cannot be justified. several studies revealed the oral health status of institutionalized orphans could be differing than general populations (26-32). as far as it's known, there was only iraqi study conducted by ahmed (26), concerned oral health status and treatment needs among institutionalized orphans compared to control group. while none of institutionalized orphans was obese, high percentage was found among controls followed by non-institutionalized orphans. thinness may be present among noninstitutionalized orphans in elevated per cent compared to the other groups; and this may be due to poverty level at which the former group lived. the comparison of malnutrition of the present study with other studies is difficult because of using of different criteria in classification of malnutrition; moreover, there is no study about the nutritional status in relation to the oral health status of orphans to compare with its results. the means of bmi-age of each institutionalized and non-institutionalized orphans were lower than that estimated by ahmed (33) for the age 7-12 years, but the mean bmi-age for controls in the present study at the same age range is comparable to what estimated by ahmed (33). however high percentage of children in the three groups was having acceptable weight especially the institutionalized orphans and this finding comes in accordance with al-ani (18) for age 12 and ahmed (33) for the age group 7-12 years. this is an j bagh college dentistry vol. 29(4), december 2017 oral health status among pedodontics, orthodontics and preventive dentistry 107 indication of improvement in the nutritional status among iraqi children in the current years. results showed that the majority of institutionalized and non-institutionalized orphans had lower percentage mild type of plaque index than controls, but elevated percentage of moderate plaque index compared to the controls. this may explain the significant high mean values of plaque index in orphans (with no significant difference between them) compared to controls. this result disagrees with ahmed (26), mazhari et al. (27) and camacho et al. (28). this finding was in controversy with brushing teeth/day indicated some of orphanage's staff/family members were unaware about consequences of improper oral hygiene maintenance, or over reporting of tooth brushing by children or simply reflecting a lack of tooth brushing skills (32). dental plaque was found to be the main causative factor for gingivitis (34, 35), this may explain the higher significant mean gi which was found in orphans groups (with no significant difference between them) compared to controls, while the reverse was reported by ahmed (26) gu et al. (30) and the result of this study was lower than reported by mazhari et al. (27) who revealed moderate and sever gingivitis among orphans. the cali mean rank among institutionalized orphans was found lower than controls with no significant difference between them, and this agrees with ahmed (26) but disagrees with ojahanon et al. (29) gu et al. (30), and sharma et al. (31). however, these two groups were significantly lower than non-institutionalized orphans, reflecting a lack of tooth brushing skills in the latter group, or neglecting due to limited resources and time of the family member, thus they in need of dental education programs through schools. according to body mass index indicators; results revealed significant elevated pli was found among thinness compared to normal weight group of institutionalized orphans. however, higher pli was found among thinness group than overweight/obese of non-institutionalized orphans with no significant difference. this may partly be attributed to the fact that the most of malnourished children are from low socioeconomic families that exhibit also a poor oral hygiene (36). non-significant elevated gi was found among thinness group compared to acceptable/or overweight/obese of institutionalized and non-institutionalized orphans respectively. the increase in gi in thinness group was in accordance with increase in pli in the same group, or may be due to lack of certain vitamins and nutrient which increase the severity of gingival inflammation (37), especially vitamin a and c role in maintaining and repairing healthy connective tissue along with its antioxidant properties (16, 38). this study revealed cali mean rank, was high among thinness than acceptable /or overweight/obese, and this due to bad brushing skills and oral cleanliness among malnourished children, or due to increase in pli in the same group. references 1. park k. park's textbook of preventive and social medicine 23rd ed. 2015. 2. hussain h. conflict in iraq, human costs, morbidities and civillain suffering. in third isa forum of sociology (july 10-14, 2016). isaconf, 2016. 3. damle sg.textbook of pediatric dentistry, 3rd ed. new delhi. 2009. 4.al-alak, mm., abdul hameed sm., bader ss., huwail mj., ash h. and national steering committee. iraq multiple indicator cluster survey-2011. preliminary report april 2012. 5.sheetal a, hiremath vk, patil ag, sajjansetty s and kumar sr. malnutrition and its oral outcome – a review. j clin diagn res 2013; 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20(3): 222-229. j bagh college dentistry vol. 29(4), december 2017 oral health status among pedodontics, orthodontics and preventive dentistry 109 ین في لالطفال االيتام المقیم الغذائیة الحالة الصحیة للفم وعالقتھا مع الحالة المؤسسات و االيتام غیر المقیمین في المؤسسات في مدينة بغداد الخالصة خاصة ضمن الفئات التي تعاني من الحرمان و من ان حالة التغذية هي احد العوامل المؤثرة على الحالة الصحية الفموية, : المقدمة االسنان. ماحول انسجة على صحة وتاثيرهايتام لال هو تقييم الحالة الغذائيةان اهداف هذه الدراسة ضمنهم االطفال االيتام. يتاماال شملت اناث( 126ذكور و 152سنة ) 21-6طفل ضمن الفئة العمرية العينة من خمسمائة: تكونت المواد و طرائق البحث تقييم.تم الذين هم تحت رعاية الوالدين الضابطةغير مقيمين في مؤسسات االيتام ومجموعة يتاممقيمين في مؤسسات االيتام و اال الجرثومية الصفيحة مقدار لتحديد ramfjordفحص االسنان اعتمادا على مؤشر , وتمbmiكتلة الجسم مؤشر حسب الغذائية الحالة .12تم نحليل البينانات حسب برنامج التحليل االحصائي نسخة و حالة القلح. اللثة ,التهاب و بفرق معنوي عالي قياسا من غير المؤسسات المؤسسات كان متدني بفرق معنوي قياسا لاليتام يتاممؤشر كتلة الجسم ال ان :النتائج الصفيحة. ان مؤشرات الضابطةللمجموعة قياساغير المؤسسات اقل بفرق معنوي , بينما كان االيتام من الضابطةللمجموعة للمجموعة قياسااللثة لكل من ايتام المؤسسات وااليتام من غير المؤسسات كانوا اعلى بفرق معنوي عالي والتهاب الجرثومية بينما متوسط مرتبة مؤشر القلح لاليتام من غير المؤسسات كان اعلى بفرق معنوي عن ايتام المؤسسات و المجموعة , الضابطة اظهرت مؤشرات كتلة الجسم لمجموعتي ايتام المؤسسات وغير المؤسسات,ان مجموعة النحافة من المؤسسات لديهم قيمة .الضابطة ,ومع هذا فقد وجدت قيم عالية بدون فروق معنوية لمؤشرات التهاب اللثة والقلح عليا من معدل الصفيحة الجرثومية بفرق معنوي ضمن مجاميع النحافة. باالضافة ان نظافة الفم و , هذه الدراسة اشارت ان حالة التغذية هي عامل نسبي, قد تؤثر على حفظ صحة الفم و اللثةاالستنتاج: .باالسنانالعناية برامج رية يجب التركيز عليها من خالل الرعاية الوقائية ضرو dropbox 3 dilyar 2 f 14-19.pdf simplify your life j bagh college dentistry vol. 29(1), march 2017 the influence of restorative dentistry 9 the influence of chlorhexidine diacetate salt incorporation into soft denture lining material on its antifungal and some mechanical properties altaf qussay abraham, b.d.s. (1) nabeel abdul-fattah, b.d.s., m.sc. (2) abstract background: one of the most common problem associated with the used of soft denture lining material is microorganisms and fungal growth especially candida albicans, which can result in chronic mucosal inflammation. the aim of this study was to evaluate the influence of chlorhexidine diacetate (cda) salt incorporation into soft denture lining material on antifungal activity; against candida albicans, and the amount of chlorhexidine diacetate salt leached out of soft liner/cda composite. furthermore, evaluate shear bond strength and hardness after cda addition to soft liner materials and methods: chlorhexidine diacetate salt was added to soft denture lining material at four different concentrations (0.05%, 0.1% and 0.2% by weight). four hundred and fifty specimens were made and divided into four groups according to the test to be performed. disk diffusion test was used to evaluate the antifungal activity of the soft liner/cda composite after four different periods of incubation in artificial saliva. uv spectroscopy was used to evaluate the amount of accumulative and periodic cda released in artificial saliva after 2 days, 2 weeks and 4 weeks incubation in artificial saliva. the shear bond strength and shore a hardness was measured after 2 and 4 weeks incubation in artificial saliva and the results were statistically analyzed. results: all experimental groups showed a highly significant increase in diameter of inhibition zone around the test specimen in compare with control group. the release of chlorhexidine showed to be dose dependent. the shore a hardness a highly significant increase with the addition of cda and as for shear bonding strength, the addition of cda at 0.5% and 1.5% percentage resulted in a highly significant decrease in bond strength, while 2.5% and 3.5% percentage showed non-significant differences in compare with control. conclusion: soft denture lining material with antifungal properties was the result of cda salt incorporation which indicate that chlorhexidine was released in affected concentration from soft liner/cda composite. this incorporation resulted in hardness increase and did not affect the shear bond strength for 2.5% and 3.5% percentage. keywords: soft denture liners, antifungal activity, chlorhexidine diacetate salt. keyword: soft denture liners, antifungal activity, chlorhexidine diacetate salt(j bagh coll dentistry 2017; 29(1):9-15) introduction lack of antimicrobial properties is one of the most common problem associated with the used of soft denture lining material. denture stomatitis is most associated by poor oral hygiene along with fungal and microorganism growth. (1, 2) the routine treatment denture stomatitis includes prescription of antifungal drugs, denture repair or replacement and application of prophylactic measures (3, 4), and this treatment can be further complicated for patients with special needs or elderly because this type of patients have difficulty in keeping clean denture, and following antifungal drug routine. (5) chlorhexidine di-acetate salt and the related compounds are used as antiseptics and disinfectants, and exhibit a broad spectrum of antimicrobial activity including candida albicans (6.7). in the present study heat cure acrylic-based soft denture lining material impregnated with cda salt to produce resin material with antifungal properties that has the ability to reduce candida albicans growth and evaluate whether soft liner properties will be affected by this addition or not. . materials and methods: heat cured acrylic-based soft denture liner material (vertex™soft, vertex-dental, netherlands) was impregnated with chlorhexidine diacetate salt (xi'an lyphar biotech co. ,china) in different percentages (0. 5%, 1.5% ,2.5%cand 3.5 by weight). a total of four hundred fifty specimens were prepared and divided into four groups according to the test to be performed. evaluating the antifungal activity of soft liner/cda samples by using disk diffusion test: sample fabrication samples were made by using plastic model with the dimension of (10 mm diameter and 3.0 mm thickness) (8) which were invested in hard but flexible silicon material then after that both silicone and the plastic pattern were invested in stone to form silicone-stone mould. the soft lining material was mixed, packed and cured as instructed by manufacturer, and as for experimental samples, chlorhexidine diacetate salt was added to the liner powder and mixed manually (9, 10). the samples were finished, polished, sterilized by autoclave after the curing process was complete and storage in artificial saliva. 1) m.sc. student. department of prosthodontics. college of dentistry, university of baghdad. 2) professor. department of prosthodontics, college of dentistry, university of baghdad j bagh college dentistry vol. 29(1), march 2017 the influence of restorative dentistry 10 isolation of c. albicans: a sterile cotton swab was used to isolate candida albicans from the oral cavity of patients that visit the college of dentistry with denture stomatitis symptoms by rubbing the lesion with the swab (11). than after that sabouraud dextrose agar (which was prepared as instructed by the manufacturer) was used to incubate the swab aerobically for 24-48 at 37ca, and then kept at 4°c for further investigation. (12) identification of c.: to identify candida albicans germ tube formation procedure was used (13) and api apicandida (biomérieux) system was used also which is a biochemical method for identification. preparation of culture media for disk diffusion test: sabouraud dextrose agar was used as a culture media for disk diffusion test which was prepared as instructed by the manufacturer. (14) evaluation disk diffusion test: to produce a yeast stock suspension with turbidity equal to 0.5 mcfarland, 5 ml of 0.85 % sterile normal saline was used to suspend isolated colonies of c. albicans and mcfarland densitometer was used to ensure that the suspension had turbidity equal to0.5 mcfarland. the agar plate was swabbed carefully in 3 directions by sterile swab after being dipped into suspension and excess fluid was pressed out to achieve even growth on the surface of the agar plate. after that the agar surface has been left for about 5 minute, then the experimental and control disks were placed on the surface of the culture media and incubated at 37º c for 48 h. aerobically. the inhibition zone that may appear around the disks was measured by using electronic digital caliper. this procedure was repeated for the samples that incubated in artificial saliva for 2 days, 2 and 4 weeks. (15) chlorhexidine diacetate salt release test: a round plastic model with the dimension of 10mm in diameter and 3mm in thickness was used to prepare the specimens that used to evaluate cda release (16). all specimens were placed in a plastic plane tubes and immersed in 1ml of artificial saliva and kept at 37◦c for 4 weeks and during this period the incubation solution was replace every 2 days and with each replacement the artificial saliva of each tube was collected, and the change in optical density was measured by uv spectroscopy (uv160ashimadzu, japan) at a wave length of 257.5 nm. (17, 18) shore a hardness test to evaluate hardness of soft denture lining material, soft liner disk with dimension (3mm, 30 mm) thickness and diameter on top of acrylic disk with the same dimension was used (19,20).two plastic patterns on top each other with the previously mentioned dimension was used to made silicone-stone mould. rapid heat cured acrylic resin (vertex™ rapid simplified, vertex-dental, netherlands) was mixed, packed into the space created by removing the upper pattern while the lower one still present to act as a spacer for lining material and cured as instructed by manufacturer then after completing the polymerization process, the acrylic resin disk was removed from the mould, trimmed and polished. the acrylic disk was then returned to the mould after removing the plastic spacer and soft liner mixed, packed against acrylic disk and cured as instructed by manufacturer. shore a durometer (th 200, germany) was used to measure soft liner hardness .the testing value was taken as an average of five different reading that were taken directly from the scale reading of durometer. shear bond strength test shear bonding strength between acrylic denture base and soft lining material was evaluate by using two acrylic block with dimensions of (75 mm*25 mm*5 mm, length, width, depth respectively) with stopper of depth about 3 mm (21) rapid heat cured acrylic resin (vertex™ rapid simplified, vertex-dental, netherlands) was used. mixing packing and curing was done as instructed by the manufacturer. one block of acrylic put over the other block leaving a space between them with the dimensions (25 mm*25 mm*3 mm length, width, depth respectively) for reline material application, that filled with wax. then the whole specimen (the 2 blocks with wax) was invested into silicon material to fabricate a mould for final specimen curing. wax elimination procedure was done and the formed space (25mm × 25mm × 3mm) was filled with soft lining material and curing was carried out (fig.2 a&b). the specimens were tested using instron testing machine (instron 1195, england) at load cell capacity of (100kg) and cross head speed equal to (0.5mm/min). the shear bond strength was calculated by dividing the maximum load figure.1 plastic model and silicone silicone-stone mould used in disk diffusion test j bagh college dentistry vol. 29(1), march 2017 the influence of restorative dentistry 11 required for the sample to fail on cross section area of the testing sample according to (astm specification d-638m, 1986). formula results: ftir analysis showed that there was no chemical interaction between the soft lining material and cda. the antifungal activity and the release of chlorhexidine showed to be dose and time dependent (increase with concentration and decrease as incubation period increase). the shore a hardness showed a highly significant increase with the addition of cda and decrease as incubation period increase for control and 3.5% group .as for shear bonding strength, the addition of cda at 0.5% and 1.5% percentage resulted in a highly significant decrease in bond strength, while 2.5% and 3.5% percentage shown non-significant differences in in compare with control, while all group showed increased with time table1: descriptive statistics and one-way anova of disk diffusion test table2: lsd test between disk diffusion test means. duration groups mean s.d. ftest dry cl 0 2884.773 0.5 13.18 0.402 1.5 15.38 0.41 2.5 18.06 0.578 3.5 22.52 0.763 2 day c 0 3692.685 0.5 12.6 0.337 1.5 14.38 0.371 2.5 16.47 0.469 3.5 18.55 0.497 2 weeks c 0 1872.346 0.5 11.09 0.716 1.5 13.21 0.247 2.5 14.96 0.538 3.5 17.3 0.587 4 week c 0 0 2863.686 0.5 10 10 1.5 11.84 0.422 2.5 13.59 0.495 3.5 15.66 0.472 duration conce. md p-value dry c 0.5% -13.18 0 1.5% -15.38 0 2.5% -18.06 0 3.5% -22.52 0 0.5% 1.5% -2.2 0 2.5% -4.88 0 3.5% -9.34 0 1.5% 2.5% -2.68 0 3.5% -7.14 0 2.5% 3.5% -4.46 0 2 days c 0.5% -12.60 0 1.5% -14.38 0 2.5% -16.47 0 3.5% -18.55 0 0.5% 1.5% -1.78 0 2.5% -3.87 0 3.5% -5.95 0 1.5% 2.5% -2.09 0 3.5% -4.17 0 2.5% 3.5% -2.08 0 2 weeks c 0.5% -11.09 0 1.5% -13.21 0 2.5% -14.96 0 3.5% -17.3 0 0.5% 1.5% -2.12 0 2.5% -3.87 0 3.5% -6.21 0 1.5% 2.5% -1.75 0 3.5% -4.09 0 2.5% 3.5% -2.34 0 4 weeks c 0.5% -10 1.5% -11.84 0 2.5% -13.59 0 3.5% -15.66 0 0.5% 1.5% -1.84 0 2.5% -3.59 0 3.5% -5.66 0 1.5% 2.5% -1.75 0 3.5% -3.82 0 2.5% 3.5% -2.07 0 a b figure 2: (a) acrylic block used in test, (b) custom-fabricated flask j bagh college dentistry vol. 29(1), march 2017 the influence of restorative dentistry 12 table 3: descriptive statistics and one-way anova of periodic cda release table 4: lsd test between periodic cda release test mean table 5: descriptive statistics and one-way anova of shore a hardness test table 6: lsd test between shore a hardness test mean table 7: descriptive statistics and one-way anova of shear bonding strength test. duration conce. mean s.d. f-test 2 days c 0 0 301.038 0.5 0.025 0.005 1.5 0.051 0.005 2.5 0.155 0.03 3.5 0.209 0.02 2 weeks c 0 0 797.508 0.5 0.004 0.003 1.5 0.013 0.003 2.5 0.043 0.006 3.5 0.101 0.008 4 weeks c 0 0 591.077 0.5 0 0 1.5 0.001 0.001 2.5 0.003 0.003 3.5 0.059 0.007 2 days conce md p-value c 0.5% -0.025 0 1.5% -0.051 0 2.5% -0.155 0 3.5% -0.209 0 0.5% 1.5% -0.026 0 2.5% -0.13 0 3.5% -0.184 0 1.5% 2.5% -0.104 0 3.5% -0.158 0 2.5% 3.5% -0.054 0.002 2 weeks c 0.5% -0.004 0.008 1.5% -0.013 0 2.5% -0.043 0 3.5% -0.101 0 0.5% 1.5% -0.009 0 2.5% -0.039 0 3.5% -0.097 0 1.5% 2.5% -0.03 0 3.5% -0.088 0 2.5% 3.5% -0.058 0 4 weeks c 0.5% 0 . 1.5% -0.001 0.155 2.5% -0.003 0.062 3.5% -0.059 0 0.5% 1.5% -0.001 0.155 2.5% -0.003 0.062 3.5% -0.059 0 1.5% 2.5% -0.002 0.261 3.5% -0.058 0 2.5% 3.5% -0.056 0 duration conce mean s.d. f-test 2 weeks c. 78.423 1.728 24.486 0.5% 81.535 0.402 1.5% 82.768 1.317 2.5% 83.475 1.401 3.5% 84.225 1.928 4 weeks c. 75.708 1.761 61.969 0.5% 82.106 1.78 1.5% 83.007 0.745 2.5% 84.044 0.976 3.5% 81.838 0.909 duration conce m.d pvalue 2 weeks c 0.5% -3.113 0.002 1.50% -4.346 0 2.5% -5.052 0 3.5% -5.802 0 0.5% 1.5% -1.233 0.098 2.5% -1.94 0.011 3.5% -2.69 0.011 1.5% 2.5% -0.707 0.772 3.5% -1.457 0.322 2.5% 3.5% -0.75 0.854 4 weeks c 0.5% -6.398 0 1.5% -7.299 0 2.5% -8.336 0 3.5% -6.13 0 0.5% 1.5% -0.901 0.132 2.5% -1.938 0.002 3.5% 0.268 0.65 1.5% 2.5% -1.037 0.084 3.5% 1.169 0.052 2.5% 3.5% 2.206 0 duration conce. mean se f-test 2 weeks c 0.415 0.059 10.183 0.5% 0.303 0.019 1.5% 0.332 0.03 2.5% 0.352 0.02 3.5% 0.391 0.068 4 weeks c 0.574 0.051 6.261 0.5% 0.449 0.098 1.5% 0.481 0.099 2.5% 0.514 0.082 3.5% 0.599 0.054 j bagh college dentistry vol. 29(1), march 2017 the influence of restorative dentistry 13 table 8: lsd test between shear bonding strength test mean discussion the most common problem associate with the use of soft denture lining material is fungal colonization especially candida albicans and along with plaque accumulation inflammation and infection of denture bearing area will develop.(23) in this study an attempt was made to produce soft liner with antifungal activity by incorporating chlorhexidine diacetate salt. the results of this study showed that the antifungal activity of cda is a concentration and time dependent (the antifungal activity increase with concentrations of added drug and decrease when the period of incubation in artificial saliva increase) in which 3.5% group showed that highest mean value during all incubation period (22.52, 18.55, 17.3, 15.66 mm.) (table 1) the explanation for this could be due to increase in the amount of chlorhexidine leaching out of test specimens with the increase in the concentration of the added drug and decrease when the period of incubation in artificial saliva increases. (24) and this was confirmed by the result of chlorhexidine diacetate release test that was conducted in this study which showed that the release is also concentrations and time dependent (increase with concentrations and decrease when the period of incubation in artificial saliva increase) which 3.5% group showed that highest mean value during all incubation period (0.209, 0.101, 0.059) (table 3). with the higher concentration appeared during the first 2 days and the explanation for that is the result of surface release of cda first and followed by slow release which could be the cause of processes more complex, which involving the formation of fluid clusters around the drug molecules and the interaction of these clusters with the mechanism of acrylic resin for fluid absorption. (25,26) the result of this study showed significant increase in the mean value of hardness for experimental group in compare with control group and from both periods of incubation in artificial saliva(table 6), in which control group showed the lowest mean value for both incubation period (78.423, 75.708) (table 5) . this finding can be explained by the fact that added antifungal agent like chlorhexidine dictate in to soft liner material may affect the plasticizers ability for softening gel formation and its ability for polymeric chains penetration, and cda salt may act like fillers that increase soft liner hardness and resistance when dispersed inside it (27). this study also showed that the mean value of hardness significant decrease for both control group and 3.5% group, and a nonsignificant different for 0.5%, 1.5%, 2.5% group with time. the decrease in the mean value of hardness for control group and 3.5% group could be the result water absorption that may act as additional plasticizers that improve the resiliency of the material and cause decrease in hardness.and as for the non-significant different in mean value of hardness for 0.5%, 1.5%, 2.5% group with time could be the result of insufficient water absorption by these groups during the second period of evaluation. (28, 29) as for shear bonding strength this study showed that the mean value of shear bonding strength for 0.5% and 1.5% groups was a significant decrease in the in compare with control, this can be attributed to leakage of residual monomer and other soluble impurities into artificial saliva which will leave empty spaces for water to get in (30), and in addition to that cda is another factor which increases the micro porous as it is water soluble, so it dissolves and create more spaces that filled with water which result in swelling and stress build up at bonding interface. and as for2.5%, 3.5% group, it showed a non-significant difference in the means value of shear bonding strength in pvalue md conce. duratio n 0.001 0.111 0.5% c 2 week 0.012 0.082 1.5% 0.057 0.063 2.5% 0.922 0.023 3.5% 0.114 -0.029 1.5% 0.5% 0 -0.049 2.5% 0.017 -0.088 3.5% 0.447 -0.02 2.5% 1.5% 0.151 -0.059 3.5% 0.447 -0.039 3.5% 2.5% 0.022 0.126 0.5% c 4 week 0.115 0.093 1.5% 0.317 0.06 2.5% 0.825 -0.025 3.5% 0.945 -0.032 1.5% 0.5% 0.509 -0.065 2.5% 0.006 -0.15 3.5% 0.924 -0.033 2.5% 1.5% 0.034 -0.118 3.5% 0.089 -0.085 3.5% 2.5% j bagh college dentistry vol. 29(1), march 2017 the influence of restorative dentistry 14 compare with control group. and this could be the result of leaching out the plasticizer, which in turn leads to the increased stiffness.(31) this study also showed significant increase in the mean value of shear bond strength for all group (control and experimental) (32,33). references 1 wright p.s., young k.a., riggs p.d., parker s., and kalachandra s. evaluating the effect of soft lining materials on the growth of yeast. jprosthet dent 1998; 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27:292–6. 25. karine padois, valérie bertholle, fabrice pirot, truc thanh ngoc hyunh, alessandra rossi, paolo colombo, françoise falson, and fabio sonvico. chlorhexidine salt-loaded polyurethane orthodontic chains: in vitro release and antibacterial activity studies. aaps pharmscitech .3 may 2012 26. soukaina ryalat, rula darwish, and wala amin. new form of administering chlorhexidine for treatment of denture-induced stomatitis. ther clin risk manag. 2011; 7: 219–225. 27. thomas r. schneid dmd an in vitro analysis of a sustained release system for the treatment of denture stomatitis article first published online: 28 jun 2008 28. addy m., and handley r.the effects of the incorporation of chlorhexidine acetate on some physical properties of polymerized and plasticized acrylics. journal of oral rehabilitation 1981; 8(2), 155–163 29. vanessa m. urban, thiago f. lima, mirian g. bueno, marcelo giannini, jo˜ao n. arioli filho, ana l´ucia p. f. de almeida& karin h. neppelenbroek. effect of the addition of antimicrobial agents on shore a hardness and roughness of soft lining materials. journal of prosthodontics 2014: 1–8 30. braden m. and wright p.s.water absorption and water solubility of soft lining materials for acrylic dentures. j dent res 1983; 62(6): 764-768. j bagh college dentistry vol. 29(1), march 2017 the influence of restorative dentistry 15 31. farzin m, bahrani f and adelpourb e. comparison of the effect of two denture cleansers on tensile bond strength of a denture liner. j dent (shiraz) 2013; 14(3): 130–135 32. garcia rm, léon bt, oliveira vb, del bel cury aa. effect of a denture cleanser on weight, surface roughness, and tensile bond strength of two resilient denture liners. j prosthet dent 2003; 89: 489-94 33. mese a., guzel k.g., uysal e. effect of storage duration on tensile bond strength of acrylic or siliconebased soft denture liners to a processed denture base polymer. acta odontol scand 2005; 63: 31–35. الخالصة االخرى اليزال يمثل مشكلة جدية كان الغرض من هذه الدراسة هو تقييم إن عملية استيطان بطانة طقم االسنان اللينة من قبل المبيضات البيض والكائنات الدقيقة للفطريات )ضد ضادتأثير دمج نسب مختلفة من احد امالح الكلورهكسدين في مادة التبطين االكريليكية المعالجة حراريا اللينة لطقم االسنان على النشاط الم به . عالوة على ذلك، تقييم كمية الكلورهكسدين المتحررة من مركب البطانة اللينة مع ملح المبيضات البيض( ، وعلى قوة الربط القصية وقوة الصال .الكلورهكسدين (. تم نشر %5.0,%5.0,%5.0,%5.0: تم دمج ملح الكلورهكسدين مع مادة التبطين االكريليكية اللينة لطقم االسنان بنسب وزنية مختلفة )المواد وطرق البحث بع مائة اعداد ار مسحوق ملح الكلورهكسدين في بوليمر مادة التبطين اللينة يدويآ باستخدام السباجيوله وبعد ذلك اضيف سائل البطانة اللينة ومزجت معا.تم اي ( عينة وتم تقسيمها الى اربع مجموعات وفقا لنوع االختبار المراد اجرائه. اجري اختبار مسح الموجات تحت الحمراء لتحديد ما اذا هنالك005وخمسين ) رهكسدين ضد الفطريات على اربع فترات زمنيه تفاعل كيميائي بين ملح الكلورهكسدين ومادة التبطين اللينة. تم تقييم نشاط مزيج مادة التبطين اللينة مع ملح الكلو طة التحليل الطيفي مختلفة وباستخدام طريقة اختبار انتشار القرص. وقد تم قياس كمية الكلورهكسدين المتحررة في اللعاب االصطناعي كل يومين لمده شهر بواس جهاز باستخدام االسنان طقم قاعدة ومادة اللينة البطانة بين القصية الربط قوة قياس تم و ديروميتير أي شور جهاز باستخداملالمتصاص وتم قياس قوة الصالبه .اختبار و lsdواختبار anovaاختبار باستخدام احصائيا النتائج تحليل تم. انسترون الكلورهكسدين،وقد اظهرت نتائج اختبار : اظهرت نتائج مطياف االشعة تحت الحمراء عدم وجود اي تفاعل كيميائي بين مادة التبطين اللينة وبين ملح النتائج لعاب االصطناعي. انتشار القرص ازدياد قطرمنطقة التثبيط مقارنة بالمجموعة الضابطة، مع نقصان قطرمنطقة التثبيط بازدياد طول فترة حضانة العينات في ال ة الحضانة المستعملة مع نقصان في كمية الكلورهكسدين المتحرره وقد تم الكشف عن اثر ملح الكلورهكسدين المتحرر في محلول اللعاب االصطناعي خالل فتر لجميع المجاميع بازدياد طول فترة حضانه العينات في العاب االصطناعي . أظهرت النتائج زيادة كبيرة جدا في قوة الصالبه بعد إضافة ملح الكلورهكسدين و المجموعه الضابطه فقط مع %5.0ب االصطناعي أدت الى انخفاض قوة الصالبه للمجموعه مقارنة بالمجموعه الضابطه ، و ان ازدياد فترة الحضن في العا صية لمجموعة تغيرات غير ملحوضه على بقية المجموعات ، وقد لوحظ ان اضافة ملح الكلورهكسدين ادت الى انخفاض ملحوظ و بدرجة كبيرة في قوة الربط الق مع ازدياد القوة الرابطه القصية بازدياد فترة %5.0و %5.0ملحوظة في قوة الربط القصية للمجموعات و تم العثور على اختالفات غير %5.0و 5.0% .حضانة العينات في العاب االصطناعي لجميع العينات، لينة مع خصائص مضادة للفطريات،و : ان اضافة ملح الكلورهكسدين الى مادة التبطين االكريليكية اللينة لطقم االسنان يساعد على انتاج مادة تبطينالستنتاجا تحافظ على توافق حيوي. ذللك لتحرر الكلورهكسدين بتراكيز فعاله وبالتالي تقليل قابلية حصول التهاب الفم الناتج عن طقم االسنان. ان المادة المطورة التزال و %5.0و لم توثر على قوة الربط القصيه للمجموعتان %5.0و %5.0وقد اسفرت هذه االضافة عن انخفاض في قوة الربط القصي لمادة التبطين للمجموعتان ، في حين ادت إضافة ملح الكلورهكسدين الى ازدياد قوة الصالبه لجميع المجموعات % 5.0 dropbox 11 alan f 60-64.pdf simplify your life rabab f.doc j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 70 the role of topical application of bone morphogenetic protein 7 (bmp7) on bone healing on rabbits (immunohistochemical study on tgf-β 3 & igf-1r) rabab ikram ghareeb, b.d.s. (1) eman issa al-tamemi, b.d.s., m.sc., ph.d. (2) abstract background: bone is essentially a highly vascular, living, constantly changing mineralized connective tissue. it is remarkable for its hardness, resilience and regenerative capacity, as well as its characteristic growth mechanisms. this study aimed to: 1. to evaluate the effect of bone morphogenetic protein7 (bmp7) on bone healing in artificially created intrabony defect in rabbits upper diastema, histologically. 2. to study the immunohistochemical expression of tgf-β3 and igf-1r as bone formation markers in experimental and control groups during bone healing. material and method: forty male rabbits, was used in this study, 8 rabbits for each healing interval (3 days, 1,2 ,4 and 6 weeks). in each rabbit two bone holes were created on the right and left sides of the maxilla.bmp7 was applied to the bone hole in the left side while bone hole in the right left for normal healing. routine processing and sectioning technique performed for histological evaluation. immunohistochemical analysis utilized to localize the expression of tgf-β3 and igf-1r in experimental and control groups for all animals. results: histological findings indicated that bone defect coated with bmp7 illustrated an early bone formation, mineralization and maturation in comparison to control group. immunohistochemical findings revealed high positive expression for tgf-b3 and igf-1r in experimental in comparison to control group. conclusion: the study concluded that bmp7 protein enhance bone healing and maturation, also it regulate the expression of tgf-b3 and igf1r in bone. key words: bone, bone morphogenetic protein7, transforming growth factor beta3, insulin growth factor-1receptor. (j bagh coll dentistry 2015; 27(3):70-78). introduction bone is a connective tissue that consists of cells and extracellular matrix. bone is a dynamic tissue in constant change; maintenance of bone mass throughout life relies on the bone remodeling process, which continually replaces old and damaged bone with new bone. this remodeling is necessary to maintain the structural integrity of the skeleton and allows the maintenance of bone volume (1). bone morphogenetic proteins (bmps), they are so named for their osteoinductive properties and regulate differentiation of mesenchymal cells into components of bone, cartilage or adipose tissue. bmp7, also sometimes referred to as osteogenic protein-1, was originally identified as a potent osteogenic factor purified from (2). bmps play a pivotal part in skeletal morphogenesis and repair, promoting the differentiation of mesenchymal cells into osteoblasts and inducing new bone formation. bmps are involved in regulating mesenchymal cell differentiation and proliferation by stimulating intracellular signaling pathways (3,4). (1)master student, department of oral diagnosis, college of dentistry, university of baghdad. (2)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. transforming growth factor –beta (tgf ) is produced by many cell types, including bone marrow cells, osteoblasts, and stromal cells and is secreted in a latent form that must be activated to mediate its effects. although several mechanisms of activation in vivo have been proposed, the precise mechanism of this process is not known. both in vitro and in vivo studies have shown that tgf 1–3 have complex effects on bone. they stimulate or repress proliferation or formation of osteoblasts and osteocytes, depending on cell types and culture conditions used (5). insulin-like growth factor-i (igf-i) signaling through its type 1 receptor generates a complex signaling pathway that stimulates cell proliferation, function, and survival in osteoblasts. igf-i has a central role in the growth and development of different tissues in the embryo (6).the present study was prepared to illustrate the benefits of using a local application of bmp7 used in bone defect and to discuss the sequences of biological events of healing. materials and methods in this experimental study forty adult new zealand white male rabbits weighing 1.5 –2.5kg were used. the animals were divided into five groups and each group contains eight animals. each group was scheduled to be sacrificed at a different time periods. which were three days, 1, 2, 4 and 6 weeks. bone defect of 2-3 mm in j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 71 diameter and 2 mm in depth were created intraorally at the diastema in maxillary arch at each sides (right and left) approximately about 2-3mm in diameter and 2 mm in depth. right sides bone defects of each animal , regarded as control group, in which the bone defect left for normal healing, while left sides bone defects treated with bone morphogenetic protein 7 (bmp 7) considered as experimental group. immunohistochemical of (tgf-β3 and igf-1r) was done for each interval. results expression of tgfβ3 findings at 3 days duration: a – control group: immunohistochemical view of bone defect of 3 days duration revealed primitive new bone formation; this bone is characterized by presence of progenitor cells that are scattered randomly which shows positive expression of tgf-b3 (figure 1). bexperimental group: after 3days bone defect treated with bmp7 shows primitive ostoid tissue is formed in which number of active progenitor cells are seen that illustrate positive reaction to tgfb3. localization also positive reaction to undifferentiated mesenchymal cells (progenitor cell), endothelial cells of blood vessels mononuclear cell and fat cell with surrounding extracellular matrix in bone marrow (figure 2). figure 1:immunohistochemical expression of tgeb3 of bone defect (control) for 3days duration shows positive expression in progenitor cell (pg) endothelial cell (ec) and in extracellular matrix (arrow) of bone marrow. dab stain with hematoxylin counter stain x 40. at 1 week duration: acontrol group: positive localization of tgfb3 in osteoblast cell, osteocyte cell, osteoid tissue, progenitor cell, fat cell, fibroblast cell and endothelial cell (figure 3). bexperimental group: view of bone defect section (experimental) of 1 week duration shows positive localization of tgfb3 in formative osteoblast cell, osteocyte cell, progenitor cell and extracellular matrix of bone marrow (figure 4). figure 2: immunohistochemical view of bone defect of 3 days duration in experimental group revealed positive expression of tgfb3 in progenitor cell (pg), endothelial cell of b.v mononuclear cell (mnc) and in ground substance of bone marrow (arrow). dab stain with hematoxylin counter stain x 40. figure 3: positive localization of tgfb3 in bone defect of control group at 1 week duration expressed in osteoid tissue (ot), osteocyte cell (oc) in progenitor cell (pg) and in osteoblast cell (ob). dab stain with hematoxylin counter stain x 20. at 2 weeks duration a – control group: bone section of 2 weeks duration of control group shows bone trabeculae that are negatively stained enclosing areas of marrow tissue and surrounded by fibrous c.t which are positively stained also positive expression of tgfb3 detected by osteocyte cell and marrow tissue (figure 5). bexperimental group: view of bone defect treated with bmp7 for 2 weeks duration shows formation of bone trabeculae with positive immunohistochemical localization of tgfb3 in osteocyte cell osteoblast cell and osteoclast cell indicated for bone turn over and bone marrow tissue (figure 6). j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 72 figure 4: positive localization of tgf-b3 in formative osteoblast cell (ob), osteocyte cell (oc), progenitor cell (pg) and inflammatory cell (arrow) of experimental group of 1 week duration. dab stain with hematoxylin counter stain x 20. figure 5: immunohistochemical view shows negatively stained bone trabeculae (bt) surrounded by positively stained bone marrow tissue (bm). dab stain with hematoxylin counter stain x 20. figure 6: immunohistochemical localization of tgfb3 on osteoblast cell (ob), osteocyte cell (oc) and bone marrow tissue (arrow) in bone section of experimental group for 2 weeks duration dad stain with hematoxylin counter stain x 40. at 4 weeks duration a – control group: immunohistochemical view of bone defect of control group of 4 weeks durations shows formation of immature bone with positively stained osteoblast and osteocyte cell (figure 7). b – experimental group: view of mature bone formation for 4 weeks duration in experimental group shows positive localization of tgf.b3 in osteocyte, cell marrow tissue and haversian canal (figure 8). figure 7: immature bone formation of 4 weeks healing of bone defect (control) shows positive expression of tgf-b3 on osteocyte cell (oc) , osteoblast (ob) , while it shows negative expression in bone trabculae (bt) dab stain with hematoxylin counter stain x 40 . figure 8: positive expression of tgfb3 in mature bone for 4 weeks duration of bone defect treated with bmp7 in widely distributed osteocyte cell (oc) inside bone matrix and around haversian canal (hc) resting line are seen (arrow). dab stain with hematoxylin counter stain x 40. j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 73 at 6weeks duration: acontrol group: microphotograph of bone defect (control) for 6 weeks duration shows formation of bone with positive expression of tgfb in osteocyte cells, formative osteoblast cells and haversian canals (figure 9). bexperimental group: immunohistochemical view of bone defect treated with bmp7 for 6 weeks duration revealed mature bone formation filling the defect area , the newly bone appear dense with positive expression of tgfb in osteocyte cells, reversal line are seen separated between old bone and new bone with the presence of numerous resting lines. circular arrangement of positively expressed osteocytes around haversian canal which positively expressed could be seen in some area, positively expressed osteoblast lined these haversian canal (figure 10). figure 9:positive immunohistochemical expression of tgfb3in osteocyte (oc) cell and haversian canal (hc) in new bone of 6 weeks duration of control group . dab stain with counter hematoxylin stain x40. figure 10: positive expression of tgfb3 is seen in haversian canal (hc) positively expressed osteocyte cell (oc) and positive osteoblast cell (ob) in experimental group of 6 weeks duration dab stain with hematoxylin counter stain x 40. expression of igf-1r findings at 3 days duration: acontrol group: immunohistochemical finding of bone defect at 3 days duration (control) shows positive expression of igf –ir in bone marrow stromal cell and in extracellular matrix of bone marrow (figure 11). bexperimental group: immunohistochemical localization of igf–ir in bone defect treated with bmp7 of 3 days duration shows positive expression of igf-ir in endothelial cell, progenitor cell and in extracellular matrix of marrow tissue new bone formation were indicated and are negatively expressed (figure 12). figure 11:immunohistochemical view of bone defect of control group at 3 days duration shows positive expression of igfir in bone marrow stromal cells (bmsc) ,progenitor cells (pg), basal bone (bb) shows negative expression . dab stain with hematoxylin counter stain x 40. figure 12 positive expression of igf –ir in progenitor cell, b.v and extracellular matrix (ecm) of marrow tissue in bone defect treated with bmp7 of 3 days duration dab satin with hematoxylin counter stain x 40. j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 74 at 1week duration: acontrol group: bone section view shows positive localization of igf-ir in progenitor cell, endothelial cell and extracellular matrix of marrow tissue, new bone formation (bone trabeculae) shows negative expression (figure 13). bexperimental group: positive expression of igf_ir in progenitor cell, osteocyte cells, formation osteoblast cell rimming the border of new trabeculae (figures 14). figure 13: positive immunohistochemical localization of igf-ir in formative osteoblast cell (ob), osteocyte cell (oc), bone specules (arrow) shows negative expression in bone defect (control) for 1week duration. dab stain with hematoxylin counter stain x 20. figure14: immunohistochemical view shows bone trabeculae (bt) formation coalesce with basal bone (bb) osteocyte cell (oc) trapped inside bone matrix and osteoprogenitor cell (pg) shows positive expression of igf-ir . dab stain with hematoxylin counter stain x 40. at 2weeks duration: a – control group: microscopical evaluation of bone section in control group after 2 weeks of healing shows osteoid tissue formation, negatively expressed by igf-ir. osteocyte cell and bone marrow stromal cells are positively expressed (figure 15). b – experimental group: immunohistochemical view of bone section at 2 weeks duration of experimental group shows positive expression of igf-ir by osteoblast cell rimming the border of bone trabeculae and osteocyte cell are embedded inside the bone matrix (figure 16). figure15:immunohistochemical view of bone defect (control) of weeks duration showing negative expression of igf-ir in bone trabeculae (bt) , osteocyte cell (oc) and bone marrow stromal cells (arrow) shows positive expression of igf-ir . dab stain with hematoxylin counter stain x 20. figure 16: positive expression of igf-ir in osteoblast cell (ob) rimming the border of bone trabeculae, osteocyte cell (oc) trapped inside the bone matrix, dab stain with hematoxylin counter stain x40 at 4 weeks duration: acontrol group: microphotograph view of bone defect of control group at 4 weeks duration shows formation of immature bone trabeculae, negatively stained by igf-ir (figure 17). j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 75 b – experimental group: bone section treated by bmp7 at 4 weeks duration shows well developed bone trabeculae, positively stained osteocyte cell embedded inside bone matrix and osteoblast cell present in the border of new bone formation (figure 18). figure17:immunohistochemical view of bone defect (control) of 4 weeks duration shows formation of immature bone trabeculae (bt) negatively stained by igf-ir . dab stain with hematoxylin counter stain x 20. figure 18: positive localization of igf-ir in osteocyte cell (oc) embedded inside matrix of well developed bone trabeculae (bt) , osteoblast cell (ob) in bone defect of 4 weeks duration treated by bmp7. dab stain with hematoxylin counter stain x 40. at 6weeks duration: acontrol group: bone section of control group at 6 weeks duration shows mature bone formation with positive expression of igf-ir in osteocyte cells embedded in matrix of bone trabeculae and in haversian canal (figure 19). bexperimental group: positive expression of igf-ir in mature dense bone filling the defect area of 6 weeks duration in osteocyte cells, haversian canal and many resting lines (figure 20). figure 19: immunhistochemical view of bone section of control group at 6 weeks duration shows positive expression of igf-ir in osteocyte cell (oc) and in haversian canal (hc) while bone trabeculae (bt) show negative expression, dab stain with hematoxylin counter stain x 40. figure 20: immunohistochemical view of dense new bone formation filling bone defect of 6 weeks duration treated by bmp7 revealed positive expression of igf-ir in osteocyte cell (oc), osteoblast cell (ob) surrounded the haversian canal (hc) and many resting lines (arrows). dab stain with hematoxylin counter stain x 40. statistical analysis bone cells figure (21) illustrated graphically line chart of bone cell's mean values of (osteoblast, and osteocyte), associated with different periods of times in each group. majority of bone cell's number (osteoblast, and osteocyte) according to different periods are registered by experimental groups (tgf-b3group, and then followed by igfir group), and then finally followed with low count cells number with controlled groups. j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 76 figure 21: line chart of bone cell's mean values of (osteoblast, and osteocyte), in tgfb3 and igf-1r associated with different periods of times in each group. table (1) represents comparisons significant by (ttest) among all pairs in contrasts of experimental and controlled groups at different periods associated with bone cells (osteoblast and osteocyte). the results shows that most of contrasts are accounted significant differences in at least at p<0.05, except with osteocyte – 2 weeks and osteoblast 6weeks either for tgf-b3 or for igf-ir contrasts. it seems to be needs to continuing testing of comparisons by using (lsd) method, and that were illustrated in the next tables (2), and (3). the results shows that all probable contrasts with respect of different periods had no significant differences at p>0.05. the results shows that all probable contrasts with respect of different groups had significant differences in at least at p<0.05.bone cell's types had increasing numbers with respect of osteoblast compared with osteocyte, and experimental (bmp7) groups are accounted twice number of bone cells compared with control groups, and finally the last two periods (4 and 6 weeks) had registered significant different. table 1: comparison significant by (ttest) among all pairs in contrasts of experimental and control groups at different periods associated with bone cells (osteoblasts and osteocytes) groups bone cells/periods levene's test for equality of variances t-test for equality of means c.s. ftest sig. ttest d.f. sig. tgf-b3 control & exprimental osteoblast 2w. 4.101 0.089 -3.601 6 0.011 s osteocyte 2w. 0.000 1.000 0.000 6 1.000 ns osteoblast 4w. 3.000 0.134 -7.867 6 0.000 hs osteocyte 4w. 0.500 0.506 -8.399 6 0.000 hs osteoblast 6w. 4.000 0.092 -1.656 6 0.149 ns osteocyte 6w. 0.300 0.604 -8.490 6 0.000 hs igf-ir control & exprimental osteoblast 2w. 4.500 0.078 -6.148 6 0.001 hs osteocyte 2w. 12.500 0.012 -1.364 4 0.245 ns osteoblast 4w. 0.600 0.468 -4.645 6 0.004 hs osteocyte 4w. 0.045 0.839 -3.959 6 0.007 hs osteoblast 6w. 0.167 0.697 -1.849 6 0.114 ns osteocyte 6w. 0.429 0.537 -7.348 6 0.000 hs (*)hs: highly sig. at p<0.01; s: sig. at p<0.05; ns: non sig. at p>0.05 table 2: multiple comparisons by (lsd method) among all pairs of different periods in compact form periods mean diff. p-value c.s. (*) 2 w. 4 w. -0.031 0.970 ns 6 w. 1.000 0.225 ns 4 w. 6 w. 1.030 0.211 ns (*) hs: highly sig. at p<0.01; s: sig. at p<0.05 j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 77 table 3: multiple comparisons by (lsd method) among all pairs of different groups in compact form groups m.d. p-value c.s. controltgf-b3 tgf-b3 -5.42 0.000 hs controligf-ir 0.00 1.000 ns igf-ir -4.29 0.000 hs expr. tgf-b3 controligf-ir 5.42 0.000 hs igf-ir 1.13 0.237 ns controltgf-b3 igf-ir -4.29 0.000 hs (*) hs: highly sig. at p<0.01; s: sig. at p<0.05 discussion tgf-β plays very important roles in embryogenesis, development and normal tissue homeostasis .a broad range of biological processes, including cell proliferation, cell survival, cell differentiation, cell migration, and matrix synthesis by inducing the production of ecm molecules such as fibronectin, collagen and proteoglycan are regulated by tgf-β(7,8).in the present study tgf-β shows positive expression in control and experimental groups in bone cellsin all healing interval periods, this result in agreement with jaafar and warwar (9,10) who found positive expression in bone cells in same periods. osteoblast cells number was obtained as a highest in bmp7 group compared to control group which showed lowest number of osteoblasts. mean value of osteoblast cell number was higher in 2 weeks of bmp7 group but in 4 and 6 weeks showed a markedly decrease in number. cell counting revealed that most of surviving osteoblasts cells are settled on the bony defect site because later in 6 weeks duration, there is more formation and maturation of woven bone so most osteoblast forming bone become entrapted within the matrix and called osteocytes cell (11).the present study was in agreement with zhang et al. (12) they found that bmp-7 stimulates the transformation of mesenchymal cells into osteoblasts, stimulating bone formation in both remodeling and repairing processes andare potent physiological inducers of osteoblast differentiation and angiogenesis. the present results was confirmed with the study done by neveet al. (13) bmp-7 has been show to be able to induce immature cells to differentiate into osteoblasts .osteoclast precursors circulate amid the monocyte macrophage population and differentiate into preosteoclasts that fuse to form giant bone resorbing mature osteoclasts. the transforming growth factor β /bmps have widely recognized roles in bone formation during mammalian development and exhibit versatile functions in the body. for instance, a bmp morphogen gradient is established in a multicellular embryo, and bmp drives the differentiation of ectodermal cells and mediates dorsal patterning to establish dorsal-ventral axis. disruptions of tgf-β/bmp signaling have been implicated in multiple bone diseases including tumor metastasis, brachydactyly type a2, and osteoarthritis (14). this study was in agreement with mohamed et al. (15) who explained on a fact of early enhancement and recruitment of the fibroblasts and osteoprogenitor cells to be differentiated into osteoblasts (bone formative cells) and enhancement of osteiod tissue formation which need more supplements and more blood vessels. osteocytes formation was happened by entraption of osteoblasts within their matrix; more osteoblasts resulted in more number of osteocytes and as a result of more and faster building of bone matrix. in the present results, igf are positively expressed in both control and experimental groups and in different period intervals and in different levels according to osteoblast activity in osteoid formation. positive expression of igf –ir in bone marrow stromal cell and in extracellular matrix of bone marrow, endothelial cells, fat cell, progenitor cells, progenitor cell, osteocyte cells and osteoblast cell while bone trabeculae was negatively expressed by igf-ir ,this results in agreement with yosif (16) who found igf positively expressed in both control and experimental implants treated with platelet rich fibrin matrix and in different intervals period (3 days 1, 2 and 6 weeks ) and in different levelsaccording to osteoblast activity in osteoid formation.the present study was in agreement with digirolamo et al. (17) they study the effects of igf-1 on bone have been well documented. igf-1 has been shown to induce proliferation of osteoblastlike cells and is an important survival factor for many mammalian cell types, including osteoblasts. igf-1 production increases during the initial phases of fetal rat calvarial osteoblast differentiation andwith matrix synthesis and mineralization that may account for the ability of igf-1 to augment synthesis of type i collagen and inhibit collagen degradation in differentiated fetal rat osteoblasts. the results of the present study j bagh college dentistry vol. 27(3), september 2015 the role of topical oral diagnosis 78 record positive expression of igf in experimental group at all periods and this was in agreement with arpornmaeklong et al. (18). they found that insulin-like growth factors increase osteoblast proliferation and have a significant role in stimulating the function of mature osteoblasts. insulin growth factor -1 enhances the mitogenic action as well as the differentiation activity of bmps. in an in vivo bone–implant integration model, combined delivery of igf-i and bmp from coated titanium screws significantly improved bone formation compared to bmp alone. the igf/bmp combination seems to enhance both in vitro and in vivo osteogenesis (19). references 1. dasmah a. on remodeling and function of autogenous bone grafts in maxillary reconstruction. university of gothenburg, sweden, 2013. 2. parra-torres ay, valdés-flores m, orozco l, velázquez-cruz r. molecular aspects of bone remodeling. in: topics in osteoporosis. intech; 2013. p. 1-28. 3. bragdon b, moseychuk o, saldanha s, king d, julian j, nohe a. bone morphogenetic proteins: a critical review. cellular signalling 2011; 23(4): 609–20. 4. jimi e, hirata s, osawa k, terashita m, kitamura c, fukushima h. the current and future therapies of bone regeneration to repair bone defects. the international j dentistry 2012: 148261. 5. juarez p, guise ta. tgf in cancer and bone: implications for treatment of bone metastases. bone 2011; 48: 23–9. 6. granerio-molto f, myers tj, weis ja, longbardi l, li t, yan y, case n, rubin j, spagnoli a. mesenchymal stem cells expressing insulin-like growth factor-i (mscigf) promote fracture healing and restore new bone formation in irs1 knock-out mice: analyses of mscigf autocrine and paracrine regenerative effects. stem cells 2011; 29(10): 153748. 7. schmierer b, hill cs. tgf beta-smad signal transduction: molecular specificity and functional flexibility. nat rev mol cell biol 2007; 8: 970–82. 8. origuchi m, ota m, rifkin db. matrix control of transforming growth factor-b function. j biochem 2012; 152(4): 321–9. 9. jaafar mk. immunohistochemical evaluation of vascular endothelial growth factor and transforming growth factor-beta on osseointegration of cpti implant radiated by low level laser therapy (experimental study in rabbits). a master thesis, college of dentistry, university of baghdad, 2013. 10. warwar ah. effect of topical application of growth hormone on osseointegration of cpti implant (histological and immunohistochemical study in rabbits). a master thesis, college of dentistry, university of baghdad, 2013. 11. nanci a, whitson sw, bianco p. bone. in: ten cate’s oral histology: nanci a (ed). 7th ed. mosby-year book inc 2008. p.111-144. 12. zhang f, qiu t, wu x. sustained bmp signaling in osteoblasts stimulates bone formation by promoting angiogenesis and osteoblast differentiation. j bone and mineral res 2009; 24: 1224-33. 13. neve a, corrado a, cantatore fp. osteoblast physiology in normal and pathological conditions. cell tissue res 2011; 343: 289-302. 14. kurata k, heino tj, higaki h, vaananenhk. bone marrow cell differentiation induced by mechanically damaged osteocytes in 3d gel-embedded culture. j bone miner res 2006; 21: 616–25. 15. papachroni kk, karatzas dn, papavassiliou ka, basdra ek, papavassiliou ag. mechano transduction in osteoblast regulation and bone disease. trends mol med 2009; 15: 208-16. 16. mohamed ma, younis wh, yaseen ny. the effect of autologous bone marrow-derived stem cells with estimation of molecular events on tooth socket healing in diabetic rabbits (histological and histomorphometric study). j bagh coll dentistry 2013; 25(1):116-21. 17. yosif am. evaluation of the effect of autologous platelet rich fibrin matrix on osseointegration of the titanium implant radiographical & immunohistochemical studies in rats. a master thesis, college of dentistry, university of baghdad, 2012. 18. digirolamo dj, mukherjee a, fulzele k, gan y, cao x, frank sj, clemens tl. osteoblasts mode of growth hormone action in osteoblasts. j biol chem 2007; 282: 31666-74. 19. arpornmaeklong p, kochel m, depprich r, ku¨blernr, wu¨rzlerkk .influence of platelet-rich plasma (prp) on osteogenic differentiation of rat bone marrow stromal cells. an in vitro study. int j oral maxillofac surg 2004; 33: 60–70. 20. kempen dh, creemers lb, alblas j, lu l, verbout aj, yaszemski mj, dhert wj. growth factor interactions in bone regeneration, tissue engineering. tissue eng part b rev 2010; 16: 551-66. dropbox 10 ali 53-57.pdf simplify your life dropbox 1579710004186887.pdf simplify your life abdulkarim.doc j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 1 the influence of cavity design for cusp coverage on fracture strength of weakened maxillary first premolars using two esthetic restorative systems (cad/cam hybrid ceramic and nanohybrid composite) (an in vitro study) zainab salman jawad, b.d.s., h.d.d. (1) abdul karim j. al-azzawi, b.d.s., m.sc. (2) abstract background: maxillary first premolar with wide mod cavity more susceptible to fracture. the aim of this study was to assess the influence of cavity design for cusp coverage on the fracture resistance of weakened maxillary first premolar restored with cad/cam hybrid ceramic versus nanohybide composite. materials and methods: fifty six intact maxillary first premolars of approximately comparable sizes were divided into seven groups eight for each: group a: intact teeth (control group); group b: teeth prepared for mod inlay; group c: teeth prepared for mod onlay covering the lingual cusp; group d: teeth prepared for mod covering buccal and lingual cusps ,the previous three groups indirectly restored with nanohybrid composite (3m espe z 250 xt); group e,f,g prepared with the same design as group b, c, d respectively and restored with cad/cam hybrid ceramic (vita enamic). results: an axial compression test was used to measure the fracture strength of experimented teeth. the readings were analyzed statistically by t-test, one way anova and lsd, then the mode of fracture had been examined. the results showed that sound teeth in group (a) had more fracture resistance values than all experimental groups and the difference were highly significant with group (b, e, f, g).when the influence of cavity design tested among composite groups it showed highly significant difference between group (b) and (c)and the highest fracture resistance value was for group(c), whereas the influence of cavity design among enamic groups showed highly significant difference between group (e) and (g) the highest fracture resistance value was for group(e).t-test between similar designs showed non-significant difference between mod groups and highly difference between other groups. conclusions: cusp coverage increased the fracture resistance of composite groups but result in non-restorable fracture, while enamic total onlay presented promising fracture resistance with favorable mode of fracture. key words: fracture resistance, cad/cam, hybrid ceramic, vita enamic, nanohybrid composite, cusp coverage. (j bagh coll dentistry 2015; 27(1):1-10). introduction during cavity preparation the removal of marginal ridges, occlusal enamel and cusps weakness result in a progressive decrease in fracture resistance in teeth (1). indirect metallic restorations or amalgam restorations with occlusal recovering were first indicated to reduce the chance of fracture and increase teeth strength (2). the use of ceramic and resin composite materials for posterior tooth restorations as alternative materials to metallic restorations had been increased in the past decades (3, 16) . dental ceramics are considered to be esthetic restorative materials with desirable characteristics, such as translucency, fluorescence, and chemical stability. they are also biocompatible, have high compressive strength, and their thermal expansion coefficient is similar to that of the tooth structure. since ceramics are fragile, cavity preparation design for posterior teeth restored with ceramic (1)master student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. restorations should increase their resistance to fracture (4,5). tooth preparation designs advocated for posterior ceramic restorations have been based on traditional cast metal restoration designs, but with more occlusal tooth reduction and a slightly increased taper reduced chance of restoration failure and increase thier longevity (6). in spite of their many advantages, direct composite resins are technically sensitive and have polymerization shrinkage, postoperative sensitivity and low wear resistance (5,7). indirect inlays/ onlays fabricated with composite resins provide excellent esthetic results that may also reinforce tooth structure. this is because a more conservative preparation design can be used since the bonding procedures strengthen the cusps and provide additional support for the dentition. additional clinical benefits include precise marginal integrity, wear resistance similar to enamel, wear compatibility with opposing natural dentition, ideal proximal contacts, and excellent anatomic morphology (8). clinical cad/cam machines have stimulated dentists to provide more conservative restorations than in the past (9). vita enamic, the first j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 2 dental hybrid ceramic for cad/cam restorations in the world, has dominant ceramic network reinforced by a polymer network for that it combines the positive characteristics of a ceramic and a composite so it is important to study their effect on fracture resistant of weakened teeth and the suitable design prepared to receive this material (10). materials and methods samples selection and preparation fifty six sound human maxillary first premolar freshly extracted for orthodontic reasons were collected from patients of ages range between 16-20 years. the teeth had two fused roots and stored in 0.2% thymol solution for seven days (11). calculus and soft-tissue deposits were removed with a hand scaler and ultrasonic scaler. the teeth were cleaned using a rubber cup and fine pumice water slurry and then stored in 0.9% saline physiological solution at room temperature for 24 hr (12). the teeth were also free of cracks while viewed under magnification observation (10x) and optic transillumination. to be included in the study, the premolars were required to have the following crown dimensions: 9.0–9.5 mm bucco-lingual distance; 7.0–7.4 mm mesio-distal distance and 8–8.5 mm cervicoocclusal distance. the roots of each tooth was inserted in corresponding elastic root coping that had 0.3mm thickness similar to the width of periodontal ligament made by pressing elastic foil (biostar copyplast, germany) of 0.5 mm thickness on roots models in biostar machine, then the roots with their elastic coping embedded in the self cure acrylic (vertex, netherlands) using dental surveyor, up to 2 mm below cemento-enamel junction to simulate the alveolar bone. the space created by root elastic coping was occupied by polyvinylpolysiloxane light body impression material (chromaclone pvc, ultradent, south jordan, usa) to simulate the periodontal ligament (13). an impression of each tooth crown was taken with a polyvinylsiloxane addition silicone material (elite p&p, zhermack, italy) and poured after 1 hour with type 4 die stone(elite stone, navy blue, zhermack, italy) to make tooth model that was used as an anatomic guide during the study (14) . the teeth were randomly divided into 7 experimental groups of 8 teeth each and subjected to the following procedures: group a: eight intact teeth (control group). group b: eight teeth prepared for mod inlay with extensive isthmus, indirectly restored with nanohybrid composite (filtek z250 xt, 3m espe). group c: eight teeth prepared for mod onlay with extensive isthmus covering the lingual cusp, indirectly restored with nanohybrid composite (filtek z250 xt, 3m espe). group d: eight teeth prepared for mod onlay with extensive isthmus covering buccal and lingual cusps, indirectly restored with nanohybrid composite (filtek z250 xt, 3m espe). group e: eight teeth prepared as in group b and indirectly restored with cad/cam hybrid ceramic (vita enamic). group f: eight teeth prepared as in group c and indirectly restored withcad/cam hybrid ceramic (vita enamic). group g: eight teeth prepared as in group d and indirectly restored with cad/cam hybrid ceramic (vita enamic). cavity preparation for mesio-occluso-distal inlay with extensive isthmus the standard sizes for inlay mod cavity preparation included: occlusal box with 1/2 of the intercuspal distance and the pulpal floor was prepared to a depth of 2 mm from the central groove. the buccolingual widths on mesial and distal boxes were 1/2 of the buccal-lingual distance. each box had a gingival floor depth of 1.5 mm mesiodistally and the axial wall hight range between 2-2.5mm. the gingival floor located 1 mm above the cement-enamel junction (cej). gingival floor were prepared with 90degree cavosurface angles (15) fig. (1, a),(3, a). the outline dimensions were marked on the teeth by 0.4 mm marker. a modified tapered shoulder bur had depth marking at 2 and 4 mm (ref 6847krd 314. 016, komet, germany), was used to prepare depth orientation groove (2mm in depth) following the central groove mesiodistally to the outer surface. round-ended tapered diamond bur with 3° taper (ref 8845kr. 314.018, komet, germany) was used for cavity preparation to the determined depth and drown out line. the depth of gingival floor (1.5mm) determined by the width of the end of the bur and checked by periodontal prob. all internal line angles were round taking the shape of round ended bur. the teeth were prepared by high speed air-water cooling turbine (sirona, t3 racer, germany) that adapted in modified cendres & metaux dental surveyor (bienne, swiss) that has two arms with wide range of movements fig.(2). the burs were replaced after every four teeth preparation to ensure high cutting efficiency. to finish the preparations the same bur was used at low speed handpiece .the dimensions of the j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 3 cavity were measured with the digital caliper and periodontal probe. mesio-occluso-distal onlay with extensive isthmus covering the palatal cusp (partial onlay) cavity preparation for partial onlay (po) cavity preparation, mod cavities with the same dimensions as that of previous design were prepared, then 2 mm occlusal reduction of the functional cusp (16) by using wheel bur (ref 909.314.065, komet , germany) to the mark made at the floor of depth orientation groove (dog) prepared using bur with marks (then a circular reduction as in crown preparation was prepared at the palatal surface extended 2 mm in the cervical direction using diamond bur with guide pin (ref 8372p 341 023, komet, germany). the guide pin, was not diamond coated, ensure a controlled and safe preparation so a defined finishing line created. to place the prepared finishing line deeper to 1mm, previous round-ended tapered diamond bur was used. again the preparations finished and the margin of reduced cusps beveled using the same bur with low speed hand piece fig. (1, b), ( 3, b). mesio-occluso-distal onlay with extensive isthmus covering buccal and palatal cusps (total onlay) cavity preparation. the preparation of total onlay (to) was similar to that of the partial onlay with additional 1.5mm occlusal reduction in the buccal cusp (14) fig. (1, c), (3, c). figure 1: cavity designs. (a) mod inlay cavity design.(b)partial onlay cavity design.(c) total onlay cavity design. fig. (2): cavity preparation. (a) mod inlay cavity design prepared using modified dental surveyor. (b) partial onlay cavity design preparation, cusp reduction with diamond disk. (c) finishing line preparation using the movable arm that had two joints. figure 3:. latral and occlusal view of the three designs of cavity preparations on the teeth (a) mod inlay. (b) partial onlay.(c) total onlay. indirect composite restorations for groups (b),(c)and(d) using filtek xt z 250 an impression of each preparation was taken using double viscosity polyvinylsiloxane (addition silicone). two stone models (master model and working model) were obtained from this impression. the coping template of teeth before preparation was set on the model of preparation and the cusps height determined by reamer and endo-ruler for partial and total onlay. the margin of preparation marked on template by fine marker (0.4mm) then the crown template had been cut by scissor away from the drown margin. a b c a b c a b c j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 4 the stone model of the preparation coated with three layers of die spacer till 0.5 mm from the margin then two glycerine layer (17) applied by a brush as a separating media and each layer allowed to dry for 2 minutes by inverting the model. the composite (filtek z250 xt, shade a2, , 3m espe, usa) added to the model in three layrs. the first third of composite added to the floor of the preparation using ash 49 and light cured for 20 second for each surface, then the second third added and cured allowing for the last third to be fitted by coping template of intact teeth to restore the original size, shape and anatomy (18, 19), then cured for 20 second for each surface using led curing light unite with energy between 850 mw/cm²–1000 mw/cm² (woodpecker, china). the working model broken down carefully to remove the restoration, then the restoration cleaned and checked on master model, finished and polished using soflex discs after checking the dimensions with metal gauge. the interior surface of restoration was roughened with aluminum oxide blast (50 µm) from a distance of 5cm at a pressure of 2 bars for 10 sec. (20) fig. (4). the restoration cemented to the prepared tooth with (relyx u200 rf, shade a2, 3m espe, usa) under 1 kg load for 2 minutes to be fully seated (14) using modified dental surveyor. each surface of the cemented restoration cured for 20 seconds using led curing light unite. all samples stored in distilled water at room temperature before test. figure 4: restorations of the three designs ready for cementation. indirect hybrid ceramic restorations fabrication for groups (e), (f) and (g) using vita enamic blocks sirona cad/cam system (scanner, computer with version 4.0 software, milling machine) was used to fabricate indirect ceramic restorations. all steps of fabrication were the same for the three designs as the following: computer software which was provided by the manufacturers was used for designing the restorations. the stone model of the prepared teeth sprayed with cerec optispry to remove optical highlights from the surface of the preparation and to enhance the precision of the optical impressions acquired by creating a uniformly reflective surface, then scanned with ineos blue scanner. on computer screen 3d model was created, margins drown and the path of insertion determined preparing for restoration editing to restore the tooth to its original dimensions, the depth from central groove to the floor of cavity, the boccolingual and mesiodistal dimensions, cusps height and restoration outline all of these criteria adjusted on design window. the block (vita enamic blocks of hybrid ceramic, shade 1m2-t em-14 translucent, lot 34910, vita zahnfabrik, bad sackingen, germany) inserted and fixed into milling machine (sirona cerec inlab mc xl, germany).the restoration separated from the block at the end of milling finished and polished with vita enamic polishing set (technical) and checked on stone model to be ready for cementation . the restoration inner surface etched with hydrofluoric acid gel (5%) (vita ceramic etch, zahnfabrik, bad sackingen, germany) that applied with brush for 60 sec. then the restoration cleaned with water for 60 sec. and dried for 20 sec. producing white opaque surface. vitasil silane coupling agent (zahnfabrik, bad sackingen, germany) applied with needle to the etched surface and leaved for 5 min to dry, then a coat of a.r.t. adhesive (zahnfabrik, bad sackingen, germany) spread by brush on the inner surface of restoration to be cured by light with cement (21). enamic restorations cemented to the tooth (after tooth conditioning) by vita duo universal shade cement (zahnfabrik, bad sackingen, germany) with vita a.r.t. bond. the restoration inserted and one kg load was applied on the occlusal surface as in cementation procedure of indirect composite groups. each side cured for 40 seconds using led curing light unite, then the restoration finished and polished using soflex discs. all restored samples stored in distilled water at room temperature before test. figure 4: vita enamic block inserted in sirona cerec in lab mc xl j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 5 axial compression test the fracture resistance for each sample assessed under axial compressive loading with 3-mm metal sphere (comparing it to small resistant foods that increase the risk of restoration fracture during mastication) in computer control electronic universal testing machine wdw-100 (layree, china) at a cross-head speed of 0.5 mm/min until the specimen fractured (13). on the computer screen the maximum load at the time of fracture recorded and displayed in (kn). the fractured specimens were evaluated to determine fracture patterns using a modified classification system based on the classification system proposed by burke et al. (21) : type i: isolated fracture of the restoration. type ii: restoration fracture involving a small tooth portion. type iii: fracture involving more than half of the tooth, without periodontal involvement. type iv: fracture with periodontal involvement. results the means and standard deviations of fracture strength with minimum and maximum values which were calculated in (kn) for each group is shown in (table 1). table 1: descriptive statistics of fracture resistance values (kn) for all groups. groups n mean ±s.d. min. max. a control 8 0.88 ±0.07 0.80 0.99 b mod composite 8 0.64 ±0.10 0.51 0.75 c po composite 8 0.84 ±0.13 0.70 0.99 d to composite 8 0.75 ±0.14 0.60 0.98 e mod enamic 8 0.68 ±0.09 0.56 0.84 f po enamic 8 0.59 ±0.10 0.45 0.76 g to enamic 8 0.54 ±0.09 0.43 0.71 fracture strength analysis in the following tests, p values considered as: non-significant (ns) p > 0.05 significant (s) 0.05 ≥ p > 0.01 highly significant (hs) p ≤ 0.01 the values showed that intact sound teeth (group a) presented the highest mean value (0.88 kn), whereas teeth restored with enamic total onlay (group g) showed the least fracture resistance (0.54 kn) fig.(4). figure 4: bar-chart showing the mean values of the mean values of the fracture resistance in (kn) for all groups. by using student’s t-test, a comparison between group (a) and other groups had been done. it had been found that highly statistical significance was located between group a (sound teeth) and groups b, e, f and g while nonsignificant difference was noticed between group a and c. anova test was used to make a comparison among the three designs restored with composite. the influence of difference designs on fracture resistance of teeth restored with composite was significant (table 2). further analysis was done by using lsd test to compare between each two groups with different designs that restored with composite. the difference between group b and group c statistically was highly significant but between group b and d and between group c and d was nonsignificant (table 3). table 2: comparison among different designs restored with composite by anova test. anova sum of squares d.f. mean square f-test pvalue between groups 0.165 2 0.082 5.54 0.012 (s) within groups 0.312 21 0.015 total 0.477 23 table 3: lsd test after anova test for different designs restored with composite. groups mean difference p-value b c -0.20 0.003 (hs) d -0.11 0.084 (ns) c d 0.09 0.146 (ns) j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 6 anova test was used to make a comparison among the three designs restored with enamic. the influence of difference designs on fracture resistance of teeth restored with enamic was significant (table 4).further analysis was done by using lsd test to compare between each two groups with different designs that restored with enamic. the difference between group e and f and between group f and g was non-significant while the difference between group e and g was highly significant (table 5). table 4: comparison among different designs restored with enamic by anova test. anova sum of square s d.f mean squar e ftest pvalue between groups 0.082 2 0.041 4.61 2 0.022 (s) within groups 0.186 21 0.009 total 0.268 23 table 5: lsd test after anova test for different designs restored with enamic. groups mean difference p-value e f 0.089 0.072 (ns) g 0.141 0.007 (hs) f g 0.052 0.282 (ns) student’s t-test was used between each two groups that had the same design but different materials.mod enamic had higher fracture resistance mean value than mod composite but the difference statistically was non-significant. po composite had higher fracture resistance mean value than po enamic and the difference statistically was highly significant. to composite had higher fracture resistance mean value than to enamic and the difference statistically was highly significant (table 6). mode of fracture analysis type i, type ii and type iii of fracture considered as restorable while type iv regarded as non restorable (table 7). discussion all fracture resistant values of restored teeth can be considered to exceed reported maximum biting force in the premolar region (300 n) (22). the difference between each of restored group and control group was obtained using t –test, the only non significant difference was found between po composite group and sound teeth re table 6: inferential statistics of fracture resistance (kn) and materials comparison by t-test groups descriptive statistics group difference mean ±s.d. t-test d.f. p-value b mod composite 0.64 ±0.10 -0.802 14 0.436 (ns) e mod enamic 0.68 ±0.09 c po composite 0.84 ±0.13 4.461 14 0.001 (hs) f po enamic 0.59 ±0.10 d to composite 0.75 ±0.14 3.703 14 0.002 (hs) g to enamic 0.54 ±0.09 table 7: frequency of the type of failure and comparison among all groups groups type i type ii type iii type iv total a control 0 0 6 2 8 b mod composite 0 0 3 5 8 c po composite 0 1 0 7 8 d to composite 0 2 0 6 8 e mod enamic 1 1 2 4 8 f po enamic 3 1 0 4 8 g to enamic 2 4 0 2 8 garding fracture resistance mean value this result illustrated the influence of functional cusp coverage on fracture resistance of mod cavity since the stress concentration areas on cusp tip was removed and as a sequence the stress on cusp base reduced too, so no tooth structure in this area deflected outward and the force transmitted from the thick restoration to the underlying dentin structure and distributed over a larger area of dentin, this coincide with the result of burke et al., (21), elayouti et al. (23). all enamic designs showed high significant difference when compared to sound teeth and the designs that results in greater loss of tooth structure appear to decrease the resistance to fracture of restored teeth, this coincide with stgeorges et al. (24) who studied ceramic inlay and also coincide with soares et al.(13); habekost et al. (14) these studies compare feldspathic ceramic, j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 7 feldspathic ceramic reinforced with 10% aluminum oxide and leucite-reinforced ceramics used in different cusps coverage designs and concluded that ceramics used did not provide resistance to fracture similar to that achieved for the sound teeth, this is because ceramics has low elastic modulus and cannot absorb stresses even in the presence of resin cement. since ceramics are not capable of undergoing elastic deformation at the same rate as tooth structure and resins. stress will remain inside ceramic restoration itself inducing cracks propagations which lead to fracture. comparison among different designs of composite restorations showed that group c which restored with composite with palatal cusp coverage resisted fracture more than group b which restored with mod composite and the difference was highly significant, this agree with burke et al.(21), casselli et al.(25), yamanel et al.(26), elayouti et al. (23) whose found that coverage of the at-risk palatal cusp may provide sufficient protection from fracture, this can be explained by: the composite resin characterized by lower modulus of elasticity that promoted a greater distribution of stress than the enamel. in contrast, the enamel has high elastic modulus, low strain capacity and friability, so the stress generated during the compressive load is concentrated and could initiate crack resulting in lower fracture resistance. stress concentration areas located at palatal cusp tip, for cavities without cusp reduction, were wider than for teeth with cusp coverage, further, cusp reduction relocated stress concentration areas from the remaining tooth structures to the restoration (27, 28). group to composite had higher mean values of fracture resistance than mod composite group but the difference was non-significant, this outcome coincide with yamada et al. (29). even with non-significant difference total onlay is more promising solution because it exhibit compressive type of stresses that provide protection against debonding while mod inlay show tensile interfacial stresses that cause adhesive (30). there was no significant difference between po composite and to composite groups this agree with burke et al. (21), soares et al. (31), kantardžić et al. (28) whose stated that cusp coverage produce lower stress values in dental tissues and restorative material. palatal cusp reduction may provide sufficient fracture resistance, while it allows a more conservative preparation than that required for full coverage and permit keeping buccal enamel if esthetically not compromised. these finding conflict with that of panahandeh et al.(32) who's found teeth with total onlay had significantly higher fracture resistance than those with palatal cusp coverage only. the difference with the results of previous studies may attributed to different dimensions (pulpal floor depth is 3mm, gingival floor width and depth is1 mm and 1.5 mm buccal and palatal cusp reduction) and cusp reduction done in inclined way without extension of finishing margin. comparison among different designs of enamic restorations illustrated that both partial onlay and total onlay show lower resistance to fracture than mod design this indicating that cusp coverage with this materials was not a benefit, non significant differences found between group e and f and between group f and g while the highly significant difference found between group g and group e this agree with edelhoff and sorensen(1), krejci et al.(33) , habekost et al. (14), soares et al. (13). ceramics are not capable of undergoing elastic deformation at the same rate as tooth structure and resins because they present a high elastic modulus and low strain capacity. in addition, the resin luting agent under a ceramic restoration may act as a soft layer and could reduce the effects of stress concentration. here the resin cement did not seem to be sufficient to absorb the stresses and the stresses remain inside the ceramic restoration and demand deformation, with the onlay design all stresses were located on the restorative material, since deformation did not occur and the stresses failed to be transferred to the tooth; fracture was the end result of restoration. although enamic material hybridized by polymer network that reduce its modulus of elasticity but still behave like ceramic that used in previous studies regarding fracture resistance. when comparison between the two materials within the same design had been done in this study the group of teeth restored with filtek z250 xt composite and that restored with enamic in mod cavity design have a close fracture resistance mean value of (0.64 kn) and (0.68 kn) respectively and statistically the difference was non-significant this indicating that polymer network that decrease the modulus of elasticity make the material behave just like composite in mod cavity ,this come in agreement with shor et al.(34), da silva et al. (35), santos and bezerra(36), abdallah and alrawi (37) who studied the fracture resistance of composite and ceramic in mod cavity and it was found that these two materials restored lost fracture resistance to an acceptable level and the difference statistically was non significant. j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 8 the reinforcement of remaining tooth structure is related to the use of polymer containing materials that have low elastic modulus in addition to resin cement and adhesive boning that offered support for enamel and dentin, which was altered by cavity preparations, and increasing their stiffness. at the same time the result disagree with soares et al. (38), in this study it had been found that there is significant difference between fracture resistance of ceramic group and composite groups and the latest had the highest mean value. these dissimilar findings may related to the use of feldspathic ceramic (duceram lfc) which is, unlike composite, a brittle restorative material characterized by high rigidity (15). while enamic contain dominant ceramic network and polymer network that penetrate each other ensuring strength and elasticity and preventing crack propagation (25). another important point that explains the close results is may be the synergism of behavior between the polymer network of enamic, resin cement and adhesive system, which show similar compositions and high bond capacity among them resulting in increased fracture resistance in conservative cavity (38). in addition, the prefabricated blocks are industrially conceived and highly homogeny, which should improve the mechanical properties of the restoration over time (39). high significant difference in fracture resistance between enamic and composite in both po and to designs, with the highest value found in composite groups. this come in accordance with magne and belser (30), soares et al. (38) who concluded that the fracture resistance values obtained for teeth restored with composite confirm the theory that polymer materials have greater capacity to distribute tensions in a more homogeneous way than ceramics.total onlay designs restored with composite and enamic differences agree with that of brunton et al. (40) who found teeth restored with composite onlay restorations (sr isosit) demonstrated a higher fracture resistance than onlay restorations produced from a ceramic material (empress). although, enamic contain polymer network that increase the elasticity (the elastic modulus about 30 gpa) but still has inferior resistance to fracture than composite in such cavity designs, this may be related to the dominant ceramic network. large onlays were characterized by preferable stress pattern. low elastic modulus of most composite can never fully compensate for the loss of strong proximal margin especially in large cl ii, so ceramic onlay seems to be best indication. another cause make onlay the restoration of choice is that the occlusal contact not established on tooth-restoration interface due to the difference in the mechanical behavior of the two materials. stiffness of thick and bulky ceramic restoration allows for 100% recovery of crown rigidity (30,41), so increasing the thickness of enamic restoration may improve their fracture resistance. based on the findings of this study, six of the samples in the intact control group (group a) presented favorable fracture type. these findings may be due to the presence of the palatal and buccal cusps with intact mesial and distal marginal ridges in the control group (42). in tooth restoration complex, the mode of fracture is probably the result of the mechanical properties provided by the materials, techniques employed for the restoration and cavity design, which influence the fracture pattern more than does the quantity of remaining tooth structure (25). investigations of the fracture patterns showed that, samples with higher fracture resistance produced the most catastrophic failures involving the fracture of restoration together with tooth structure (24, 14). in this study, high frequency of nonrestorable (type iv) fracture seen in all composites designs than in ceramic groups ,with highest frequency found in (group c) that had the uppermost fracture resistance value. it can be explained by the low elastic modulus of composite (approximately 16–20 gpa) and resin cement (approximately 8.30 gpa) which are similar to that of tooth. because of this flexibility, these materials require to reinforcement from the remaining tooth structure for rigidity, as a result more occlusal force was transferred to the remaining tooth structure, which resulted in greater risk of tooth fracture. in addition to flexibility of restorative materials, good bond strength to enamel and dentin make them to behave as one unite. filtek z250 xt, nano hybrid composite characterized by higher filler content, resulting in better mechanical properties, therefore a larger number of catastrophic failures had been found in this groups, which leads to indication of tooth extraction (7,25,31,38). unlike composite, enamic restorations presented isolated fractures of restorations (type i pattern). ceramics considered as a rigid materials with a high elastic modulus (approximately 65–95 gpa), showing little deformation and tend to reinforce the remaining tooth structure. the risk of tooth fracture may be minimized because the restorative material is likely to fracture before the tooth (7,38). j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 9 type i fracture is more preferable in the clinical situation, because the restoration could be replaced, while tooth failure may impair the prognosis (2,43). in this study enamic restorations shows less frequency in type vi fracture than that in composite group and in total onlay the mode of this pattern was equivalent to that seen in intact teeth.type i fracture appear in enamic in addition to type ii and iii which are considered restorable type of fracture and their frequency was similar to that of type iv in group e and f ,this come in agreement with st-georges et al.(24), ragausk et al.(7), soares et al.(31) but disagree with soares et al. (13) whose found type i fracture in all ceramic restorations this may be because they tested ceramic restoration on molars not premolars with thicker walls that had higher fracture strength and enamic has special polymer network that transmit occlusal load and allow deformation of restoration before fracture. references 1. edelhoff d, sorensen ja. tooth structure removal associated with various preparation designs for posterior teeth the international journal of periodontics & restorative dentistry 2002; 22(3):2419. 2. mondelli rf, barbosa wf, mondelli j, franco eb, carvalho rm. fracture strength of weakened human premolars restored with amalgam with and without cusp coverage. am j dentistry 1998; 11(4): 181-4. 3. bortolotto t, onisor i, krejci i. proximal direct composite restorations and chairside cad/cam inlays: marginal adaptation of a two-step self-etch adhesive with and without selective enamel conditioning clinical oral investigations 2007, 11(1) 35-43. 4. borges ga, sophr am, de goes mf, sobrinho lc, chan dc. effect of etching and airborne particle abrasion on the microstructure of different dental ceramics. j prosthet dent 2003; 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28: 127– 35. 34. shor a, nicholls ji, phillips km, libman wj. fatigue load of teeth restored with bonded direct composite and indirect ceramic inlays in mod class ii cavity preparations. int j prosthodont 2003; 16: 64-69. 35. da silva sb, hilgert la, busato al. fracture resistance of resin-based composite and ceramic inlays luted to sound human teeth. am j dent 2004; 17: 4046. 36. santos mj, bezerra rb. fracture resistance of maxillary premolars restored with direct and indirect adhesive techniques. j can dent assoc 2005; 71:585. 37. abdullah ha, alrawi ii. the influence of cad/cam ceramic and heat processed composite inlays on the fracture resistance of premolars. j bagh college dentistry 2012; 24(4):14-18. 38. soares cj, martins lr, pfeifer jm, giannini .fracture resistance of teeth restored with indirect-composite and ceramic inlay systems. quintessence international 2004; 35(4): 281-6. 39. rusin r. properties and applications of a new composite block for cad/cam. compendium 2001; 22:35–41. 40. brunton pa, cattell p, burke fj, wilson nh. fracture resistance of teeth restored with onlays of three contemporary tooth-colored resin-bonded restorative materials. j prosthet dent 1999; 82:167-71. 41. magne p, knezevic a. thickness of cad-cam composite resin overlays influences fatigue resistance of endodontically treated premolars. dent mater 2009; 25:1264-8. 42. sagsen b, aslan b. effect of bonded restorations on the fracture resistance of endodontically filled teeth. int endod j 2006; 39:900–4. 43. watts dc, wilson nh, burke fj. indirect composite preparation width and depth and tooth fracture resistance. am dentistry1995; 8(1):15-19. dropbox 11 ali 65-69.pdf simplify your life j bagh college dentistry vol. 29(4), december 2017 determination of 65 oral and maxillofacial surgery and periodontics 65 determination of implant primary stability: a comparison of the surgeon’s tactile sense and objective measurements bakir ghanim murrad, b.d.s.(1) jamal abid mohammed, b.d.s., m.sc.(2) abstract background: evaluation and measurement of primary stability could be achieved by several methods, including the resonance frequency analysis (rfa) and implant insertion torque (it) values. the need for a sufficient primary stability, guaranteed by an adequate insertion torque and implant stability quotient values, increased its importance mainly in one stage implants or in immediate loading protocols. the aims of this study was to find if there is a correlation between the peak insertion torque (pit) and isq values of implants inserted in the jaws of different bone quality which regarded as two important clinical determinant factors for prediction of implant primary stability, and to evaluate and compare whether an experienced clinician could precisely predict the primary stability of an implant on insertion with different surgical procedures using his own tactile perception. materials and methods: a total of (60) iraqi adult patients, (28) males and (32) females, age ranged (22-66) years old were enrolled in this clinical prospective study. the maximum torque value recorded on implant insertion using calibrated manual torque ratchet adopting three categories: low (10 to 30 n/cm), medium (30 to 50 n/cm), and high insertion torque (50 to 70 n/cm). the oral surgeon was asked to indicate the perceived isqs values according to his perception then implant stability quotient were measured by osstell ™. bone density (type) was determined according to subjective bone resistance encountered while drilling as proposed by lekohlm and zarb. results: a total of 160 implants were inserted. the mean peak it value was 49 ± 2.61n/cm. the mean isq value was 71.7 ± 8.86. statistical analysis show a significant correlation between isq values and pit values (p<0.001) , between it values and bone types and between perceived primary stability and actual primary stability (p<0.001) . conclusions:the corresponding significant correlations between insertion torque, and isq values may help clinicians to predict primary stability on implant insertion, that may be associated with implant survival and success rates. a moderate reliability (correlation) between perceived isq values and those measured using rf analyzer(ossttel device). key words:peak insertion torque, rfa, perceived primary stability. (j bagh coll dentistry 2017; 29(4): 65-71) introduction primary implant stability is crucial for the longterm success of dental implants. it is of paramount importance to achieve osseointegration . thus, the main goal for the oral implantologist, after dental implant surgical procedures, is represented by reaching a sufficient primary stability that ensures high success rates.(2,3) several methods for primary stability evaluation have been used, including resonance frequency analysis (rfa) and implant insertion torque (it) values. before these techniques were available, the surgeon was requested to evaluate the primary stability by percussion testing or by subjective perception during implant insertion unfortunately, these are still the most widely used methods in daily practice. (4) atsumi et al(5),reviewed various methods for dental implant stability assessment at time of placement and during healing period. it was established that resonance frequency analysis (rfa) is the most objective rather than other techniques of assessing implant stability (1) master student, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. during the different stages of implant treatment. the values recorded by rfa were noted as implant stability quotient isq.(5,6) insertion torque is an important factor for the implant primary stability at time of surgery and in deciding the loading protocol, which in turn is essential for implant survival. high it values might lead to higher primary stability.(7) sennerby and meredith(8), suggested that rfa and it represent two different features of implant primary stability, with the first demonstrating the resistance to bending load and the later signifying the resistance to shear forces. an important correlation can be established between bone density and insertion torque, both of which contribute to implant stability.(6,8) many studies positively correlate the isq and pit values and other quantitative factors affecting implant stability.(9,10) on the other hand several studies (11,12)failed to find the level of correlation between the isq and pit values. it is because of this discrepancy and inconclusive results in these previous studies that this study was conducted hypothesizing the presence of positive correlation between isq and pit values. . j bagh college dentistry vol. 29(4), december 2017 determination of 66 oral and maxillofacial surgery and periodontics 66 materials and methods this prospective study was conducted at the dental implant unit of the department of oral and maxillofacial surgery, college of dentistry, university of baghdad, during the period extending from november 2015 to august 2016. the study sample included patients who were seeking dental implant supported prosthodontic rehabilitation of single or multiple missing maxillary or mandibular teeth. informed written consent to use their data for research purposes, approved by the scientific committee of the department of oral and maxillofacial surgery, was obtained from the patients. inclusion criteria included: 1. absence of local or systemic conditions that would contraindicate dental implant surgery. 2. patient aged over 18 years of either gender. 3. partially or completely edentulous patients. 4. sufficient bone volumes (height, length and width), with or without localized bone augmentation and narrow alveolar ridges . 5. patients who are well motivated for implant therapy and maintaining good oral hygiene. exclusion criteria 1. patients who had general contraindications for oral surgery. 2. evidence of residual infection at implant sites. 3. presence of local pathological lesions in the area of implantation, as revealed by the clinical and/or radiographic examination. 4. sites showing severe alveolar bone destruction and inability to achieve reasonable primary implant stability. clinical and radiographical assessment thorough general extraoral and intraoral examination was conducted . all information were recorded in a special case sheet prepared for this study. a pre-operative panoramic radiograph (opg) was obtained for all the patients. patients were instructed to rinse their mouths with chlorhexidine 0.12 % mouth-wash for 30 seconds before surgery, then the skin around the mouth was disinfected with a sterile gauze swapped by povidone-iodine solution . surgery was performed by one experienced surgeon in all cases under local anesthesia with (lidocaine 2%, adrenalin 1:100000, 2.2 ml cartridge, septodent, france), by block and/or infiltration technique on both the buccal and palatal/lingual sides. a full-thickness mucoperiosteal flap was reflected and dental implant osteotomy site was prepared according to the manufacturers’ instructions. the tactile perception of bone drilling was assessed during the penetration of the first bur while creating the initial drill hole. at this time the surgeon made an assessment of the bone density as type i, ii, iii, iv according to the scoring system devised by lekholm and zarb. (1) this assessment was based on the cutting resistance felt by the operator during preparing the implant site. after pilot drilling, the parallel pins were inserted inside the prepared holes to optimize the correct position and alignment of planned dental implants. sequential stepped drilling until reaching the suitable final drill size. self-threaded titanium implant was inserted and tightened until a sufficient primary stability was achieved. the implant was inserted by using a manual noncalibrated implant ratchet supplied with the basic implant surgical kit or by the motorized way at speed of 20-40 rpm with a torque ranged between 35-45 n/cm . once the implant was nearly placed, a manual calibrated torque gauge ratchet(fig.1) was used to place the implant in its final position and the peak insertion torque(pit) applied was noted on the torque gauge scale and recorded (fig.2). figure 1: implant insertion using manual calibrated torque ratchet figure 2: manual calibrated torque ratchet with torque scale(10-70n/cm) (dentium co., korea). after implant insertion the surgeon was asked to indicate the probable rfa values (isqs) according to his perception. after that, the actual isqs were measured using the osstelltm isq (goteborg, sweden, 4th generation) (fig.3) with j bagh college dentistry vol. 29(4), december 2017 determination of 67 oral and maxillofacial surgery and periodontics 67 magnetic rfa measurements. the measurements were taken twice in the bucco-lingual and mesiodistal directions, the mean of the two readings represented the isq value for each implant at base line record. the cover screw was coated with fucidin ointment 2% as a lubricant and tightened into the fixture. finally, the flap was sutured back in place utilizing interruptive suturing technique with a 3/0 black silk suture. figure 3: osstell tm isq (goteborg, sweden, 4th generation). study variables: bone type assessment for each implant site the surgeon made bone density assessment according to the scoring system classified by lekholm and zarb.(1) this assessment depend up on the resistance felt during cutting as preparing the implant site and placing the implant. evaluation of peak insertion torque peak insertion torque was taken as the maximum torque value recorded during implant insertion using calibrated manual torque ratchet. the peak insertion torque records were grouped as follows: low insertion torque (10 to 30 n/cm), medium insertion torque (30 to 50 n/cm), and high insertion torque (50 to 70 n/cm). resonance frequency analysis the rfa records were grouped as follows: low isq values (1 to 59), medium isq values (60 to 69), and high isq values (70 to 100).all values were recorded as the mean of two measurements taken along the buccolingual and mesiodistal axis which represent the dental implant primary stability. data collection and statistical analysis all data follow normal distribution tested using anderson darling test, chi square test was used to analyze the difference in distribution of discrete variables. cohen's kappa analysis of agreement was used to assess the possible agreement (or disagreement) and it’s magnitude for similarity between 2 discrete variables, results presented as kappa (k) which value range from -1 to +1, and can be interpreted as a rule of thumb values of kappa from 0.40 to 0.59 are considered moderate, 0.60 to 0.79 substantial, and 0.80 outstanding. (13) intraclass correlation used to analyze the reliability between two continuous variables (between perceived and actual stability), bland altman plot used which is a graphical method to compare two measurements techniques. all data were analyzed using spss 20 program and microsoft office excel 2007. p values were considered to be significant if <0.05 (level of significance). results sixty patients (28males and 32 females), aged between (22-66 years old), who received (160) implants were included in the data record. the implants distributed according to arches as follow: (76.25%) of implants were placed in the maxillary arch and (23.75%) in the mandibular arch. the posterior sites received the highest numbers: (115) implants while (45) introduced in the anterior regions (table 1) . implant diameter (4.3 mm) was used in (34.4%) of cases, (3.8 mm) was used in (33.1%) of cases, (3.4 mm) was used in (29.4%) of cases and (4.8 mm) was used in (3.1%) of cases. the most prevalent length used was (12mm), followed by(10mm) , (14mm) and (8mm). the mean pit was 49 ± 2.61.the mean rfa was 71.7±8.86 isq. ordinal regression analysis shows the presence of statistically significant (p<0.001) positive correlation between pit and rfa, the mean actual isq is 71.7±8.86, the mean perceived isq is 69.71±8.86, the percentage of dental implants perceived with low isq value is (3.12%) while with low actual isq value (10.62%), the percentage of dental implants perceived with medium isq value is (32.5%) while with medium actual isq value (18.75%), finally the percentage of dental implants perceived with high isq value is (64.37%) while with high actual isq value (70.62%). intraclass correlation analysis demonstrated that there is a moderate reliability (correlation), and since intraclass correlation coefficient (= 0.745), this indicate that there is a moderate agreement between perceived and actual primary stability (isq), but when using bland – altman method showed that there is fixed bias (2.3%) and since the confidence interval did not include (0%) this mean that there is a significant difference.(fig.4) . j bagh college dentistry vol. 29(4), december 2017 determination of 68 oral and maxillofacial surgery and periodontics 68 the distribution of the implants inserted in healed sites by bone type is as follows: 3 in di bone (1.87%), 54 in dii bone (33.75%), 101 in diii bone (63.12%), and 2 in div bone (1.25%). statistical analysis of the present study revealed a significant correlation between pit values and bone types (p=0.001), between isq values and implant diameters, isq values and gender, pit and gender and between bone types and age. the non-significant correlations reported between isq values and bone types, isq values and implant lengths, pit and implant dimensions, isq values and age, pit and age and between bone types and gender. table 1: distribution and mean pit and isq of the implants by surgical area maxilla mandible total anterior sites 43 2 45 posterior sites 79 36 115 total 122 38 160 % 76.25% 23.75% 100% mean it value 48 ± 2.66 50 ±2.57 49 ± 2.61 mean isq value 72.59 ± 9.53 71.16 ± 8.40 71.7 ± 8.86 table2: correlation between mean isq and insertion torque values primary stability insertion torque n/cm or 95%ci ≤30 >30 >50 mean isq value 59± 19 69 ± 9 74 ± 8 0.92 0.89 – 0.96 p value<0.001 ordinal logistic regression analysis table 3:distribution and mean pit and isq of the implants by bone type bone type implants number mean pit value mean isq value di 3 36 ± 4.52 40.3 ± 19.1 dii 54 54 ± 3.02 73.1 ± 7.0 diii 101 51 ± 1.52 71.8 ± 8.5 div 2 40 ± 2.91 64.5 ± 12 figure 4: bland–altman plot for the fixed biased for the two measurements of primary stability (actual and perceived). discussion primary stability has important influence on the successful outcome of implant treatment. thus, the correlations among the techniques giving predictable information about implant stability (subjective bone classification during drilling procedure, insertion torque during implant placement, and rf analysis immediately after implant placement) may help the clinicians to determine proper treatment planning, implant design, surgical procedures and the proper time for early and-or immediate loading of dental implant, also this study aimed to find a correlation between these variables. the results of this study reveal a significant correlation between total mean isq value 71.7±8.86 and total mean it value 49± 2.61n/cm, the mean isq value for each it category was respectively (low mean isq value 59±19 with it ≤ 30 n/cm), ( medium mean isq value 69±9 with it >30 n/cm) and (high mean isq value 74±8 with it >50n/cm). since the odd ratio is less than (1.0) and the p value is less than (0.05) this indicate that when there is an increase in the it value there will be an increase in the mean (isq) value , but there is a weak direct relationship between these two values in this study . this result coincides with several recent studies that showed a significant positive correlation between it value and isq value in which high measures of it often associated with high implant primary stability isq readings.(9,10,14,16) the clinical importance of such positive correlation between isq values and pit values could be summarized in that it will provide the clinicians to use this convenient method (insertion torque) for clinical determination of primary stability during dental implant placement as a supplemental and/or alternative method to rfa. many clinical, experimental, histological and radiological studies affirmed that there is no statistical correlation between isq values (primary stability) and placement torque (pit) . (11,15,17) the percentage of dental implants which have been seated with it values >30n/cm and recorded isq values >65 was (81.25%), in other words 130 from 160 total number of dental implants that were included in this study, subsequently this high degree of primary implant stability is considered a key prerequisite for immediate or early immediate loading. although this study demonstrated no statistical significant correlation between bone type and isq values, there was a significant difference between bone type group (ii and iii) in relation to both type i and type iv regarding isq values, but this result cannot be adopted clinically because of the small sample size included in this study regarding bone type i and iv. 30 40 50 60 70 80 90 -40 -30 -20 -10 0 10 20 30 mean of actual_ps and percieved ps (a c tu a l_ p s p e rc ie v e d p s ) / a v e ra g e % mean 2.3 -1.96 sd -16.9 +1.96 sd 21.5 j bagh college dentistry vol. 29(4), december 2017 determination of 69 oral and maxillofacial surgery and periodontics 69 this result is in accordance with several studies using lekholm and zarb classification of bone quality in which no correlation between implant primary satability and bone quality had been reported.(19) also many recent clinical studies using cbct, ct scan for the recording bone density, maintain that there is no correlation between bone density and implants stability.(20,21) the present study results show a significant association between peak insertion torque values and various bone types (p = 0.001) as illustrated in table (2). the results of this study coincide with many different studies (14,22) which report a statistically significant correlation between the density values(bone types) and torque values in accordance with the lekholm and zarb index. also several recent studies using micro ct and cbct for bone mineral density measurements revealed a statistically significant correlation between bone density and insertion torque values table (3).(20,23,24) in contrast, data from a clinical study(25) showed that there was no correlation between total mean placement torque and bone type as assessed by using the lekholm and zarb index (1985). this may be attributed to the subjective nature of the latter method which is purely based on the surgeon’s perception of bone density during the implant site drilling. regarding the determination of perceived primary stability by surgeon tactile sense, there is a moderate correlation between perceived and actual primary stability (isq). when the actual mean rfa values were divided into three different groups, it became clear that isq values were generally high or medium, while low isq values were quite rare. (8,26,27) these data seem to confirm that rfa represent primary stability indicating the resistance to bending load and this could be explained due to the variations in surgical procedures that have been used in this research. the results of this study revealed a nonsignificant correlation between the dental implants (fixtures) lengths and the mean isq values which is in line with other studies confirming that the use of long implant is not always essential for obtaining higher implant stability.(16,19, 28) in contrast to this study, ,many clinical and experimental studies found that the implant length has no significant outcome on isq value when high level of bone stiffness is present; they also report that implant length could affect the isq values at seating of the implants (29,30); but in an experimental study, barikani et al concluded that implant length was a determinant factor to achieve more primary stability in low bone quality.(31) the results of this study revealed a significant correlation (p=0.015) between the dental implants (fixtures) diameters used and the mean isq values, this study was in accordance with several studies, and this could be attributable to increase in the bone implant contact (bic) surface area. (32,33) in contrast to this study, some authors found that there was no significant correlation between implant diameter and isq values and they concluded that isq values are not dependent on diameter of implant. (34,35) many studies explained that the positive relation between implant stability (isq values) and implant length and diameter, related to the bone types (cortical and trabecular) and their locations in the jaws but not for length and diameter of the inserted fixture only.(28,36) diameter and length of the implants do not seem to influence the pit values. this result is in keeping with many previous clinical and biomechanical reports.(16,37,38) many other clinical, in vitro and biomechanical studies demonstrated a statistically significant correlation between insertion torque values and dental implant fixtures diameters, maintain that insertion torque increases with the increase of bic and the amount of cortical bone engagement on using a wider implant (16,37,39) this study is limited in many aspects; first, the subjective assessment of bone quality and isq values was performed by a single operator without calibration. second, there is no standardization in the surgical procedures of dental implants which may be considered as a confounder that can affect the isq and pit reading. third, the calibrated manual torque ratchet has limited accuracy due to the possibility of fatigue after prolonged use. the significant correlation between peak insertion torque and isq values may help clinicians to predict primary stability on implant insertion, that may be associated with implant survival and success rates. a moderate reliability (correlation) between perceived isq values and those measured using rf analyzer (ossttel device). references 1. lekholm u, zarb ga.patient selection and preparation. in: bränemark pi, zarb ga, albrektsson t, editors. tissue integrated prostheses. chicago: quintessence.1985; 199-209.. 2. bayarchimeg, d., namgoong, h., kim, b. k., kim, m. d., kim, s., kim, t. i., ...& lee, e. h. evaluation of the correlation between insertion torque and primary stability of dental implants using a block bone test. j periodontal implant sci.2013;43(1):30-36. j bagh college dentistry vol. 29(4), december 2017 determination of 70 oral and maxillofacial surgery and periodontics 70 3. berardini, m., trisi, p., sinjari, b., rutjes, a. w., &caputi, s.the effects of high insertion torque versus low insertion torque on marginal bone resorption and implant failure rates: a systematic review with meta-analyses. implant dent. 2016; 25(3):1-9. 4. degidi, m., daprile, g., &piattelli, a.determination of primary stability: a comparison of the surgeon's perception and objective measurements. int j oral maxillfac. implants.2010; 25(3):558-561. 5. atsumi, m., park, s. h., & wang, h. l. methods used to assess implant stability: current status. int j oral maxillfac. implants.2007; 22(5): 743-754. 6. herekar, m., sethi, m., ahmad, t., fernandes, a. s., patil, v., &kulkarni, h. a correlation between bone (b), insertion torque (it), and implant stability (s): bits score. j prosthet dent.2014; 112(4):805-810. 7. goswami, m. m., kumar, m., vats, a., &bansal, a. s.evaluation of dental implant insertion torque using a manual ratchet. medical journal armed forces india.2015;71(2): 327-332. 8. sennerby, l., & meredith, n. implant stability measurements using resonance frequency analysis: biological and biomechanical aspects and clinical implications. periodontol 2000 2008;47(1):51-66. 9. kahraman, s., bal, b. t., asar, n. v., turkyilmaz, i., &tözüm, t. f. clinical study on the insertion torque and wireless resonance frequency analysis in the assessment of torque capacity and stability of self‐tapping dental implants. j oral rehabil.2009; 36(10):755-761. 10. dagher, m., mokbel, n., jabbour, g., &naaman, n. resonance frequency analysis, insertion torque, and bone to implant contact of 4 implant surfaces: comparison and correlation study in sheep. implant dent.2014; 23(6):672-678. 11. da cunha, h. a., francischone, c. e., fliho, h. n., & de oliveira, r. c. g. a comparison between cutting torque and resonance frequency in the assessment of primary stability and final torque capacity of standard and tiunite single-tooth implants under immediate loading. int j oral maxillfac. implants. 2004; 19 (4): 578-584. 12. degidi, m., daprile, g., piattelli, a., &carinci, f. evaluation of factors influencing resonance frequency analysis values, at insertion surgery, of implants placed in sinus‐augmented and nongrafted sites. clin implant dent relat res.2007; 9(3):144149. 13. landis, j. r., & koch, g. g. 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10(5): 449-455. 32. bilhan, h., geckili, o., mumcu, e., bozdag, e., sünbüloğlu, e., &kutay, o. influence of surgical technique, implant shape and diameter on the primary stability in cancellous bone. j oral rehabil. 2010; 37(12): 900-907. 33. gehrke, s. a., neto, s., tavares, u., rossetti, p. h. o., watinaga, s. e., giro, g., &shibli, j. a. stability of implants placed in fresh sockets versus healed alveolar sites: early findings. clin oral implants res . 2015;27(5):577-582. 34. han j, lulic m and lang np. factors influencing resonance frequency analysis assessed by osstell mentor during implant tissue integration: ii.implant surface modifications and implant diameter. clin oral implants res. 2010;21 (6): 605-611. 35. veltri m, gonzalez-martın o and belser uc. influence of simulated bone–implant contact and implant diameter on secondary stability: a resonance frequency in vitro study. clin. oral impl. res.2014; 25 (8): 899-904. 36. geng jp, tan kb, liu gr. application of finite element analysis in implant dentistry: a review of the literature. j prosthet dent.2001; 85(6): 585-598. 37. maiorana, c., farronato, d., pieroni, s., cicciu, m., andreoni, d., & santoro, f. a four-year survival rate multicenter prospective clinical study on 377 implants: correlations between implant insertion torque, diameter, and bone quality. j oral implantol. 2015; 41(3): 60-65. 38. anitua, e., alkhraisat, m. h., piñas, l., &orive, g. efficacy of biologically guided implant site preparation to obtain adequate primary implant stability.ann. anatomy.2015;199:9-15. 39. alghamdi, a. d., alshehri, f., mariana, a. d., & anil, s. influence of dimensions on the primary stability and removal torque of short dental implants.j dent oral health.2015;1(2):1-4. تعيين الثباتية االولية لزرعات االسنان: مقارنة بين الحاسة اللمسية للجراح و القياسات الموضوعية الخالصة لرنينية ددات التراتحليل بما في ذلك من الطرق، عدد خاللمن يمكن تحقيقه الثباتية األولية لزرعة االسنانتقييم وقياس الخلفية: الحاجة إلى ثباتية اولية كافية وقياس عزم الدوران المطلوب لتثبيت الزرعة. لعظمي ج االندماس القيات و عارلثباتية للزس اقياض لغر ثباتية للزرعة عالية نسبيا ، زادت أهميتها بشكل رئيسي في البروتوكول التقليدي او البروتوكول للغرسة مقرونا بعزم دوران ووحدات اليجاد ما إذا كان هناك عالقة بين عزم الدوران النهائي الالزم لتثبيت سة لمعرفة وكانت أهداف هذه الدرا الفوري لزراعة االسنان. واعتبارهما كاثنين من حة الجراقت وفي isq tmostellباستخدام جهاز الزرعة بصورة نهائية ووحدات قياس ثباتية الزرعات في العوامل المحددة الستنتاج الثباتية االبتدائية للزرعة في وقت الجراحة. أيضا لتقييم ومقارنة ما إذا كان الطبيب ذوي الخبرة العالية ية الزراعة عن طريق قابليته الحسية الخاصة.زراعة االسنان يمكن أن يتنبأ بقيم ثباتية الزرعة اثناء اجراء عمل -88(من اإلناث، تراوحت أعمارهم ما بين )28( من الذكور و )82( مريضا عراقيا بالغا ، )06ما مجموعه ) المواد وطرق العمل: المنطقة األمامية ( منهم في 54( زرعة سنية وضعت في كل من الفكين، )006( سنة في هذه الدراسة السريرية. تلقوا ما مجموعه )00 ( في المنطقة الخلفية للفكين. القيم القصوى المسجلة لعزم دوران الزرعات باستخدام آلة خاصة مدرجة لقياس قوة العزم 004و ) نيوتن 06-46نيوتن / سم(، وعزم دوران العالي ) 46إلى 26نيوتن / سم( والمتوسطة ) 26-06النهائية سجلت ثالث فئات: منخفضة ) )غوتنبرغ، السويد، الجيل الرابع( خالل isq tmostellم قياس التغيرات الحاصلة في ثباتية الزرعات باستخدام جهاز / سم(. ت عملية الزراعة وبعد ادخال الزرعات بشكل تام داخل العظم ، طلب من جراح الفم لإلشارة لقيم ثباتية الزرعات وفقا لتصوره. وتم لمقاومة العظام للحفر اثناء وقت الجراحة وفقا للتصنيف العالمي الذي استخدمه العالمان ليكهولم و تحديد كثافة العظام )النوع( وفقا زارب. . وبلغت متوسط القيمة النهائية لقوة عزم الدوران الالزمة لتثبيت الزرعات مع تم استخدامها ( زرعة سنية006ما مجموعه ) النتائج: وحدة ثباتية ) 2.20± 00.0نيوتن / سم(. كان متوسط ثباتية الزرعات مع االنحراف المعياري )8.00± 54االنحراف المعياري ) الثباتية وقيم قوة العزم ، وبين قيم العزم ونوع العظم وبين قيم زرعة. التحليل اإلحصائي اثبت وجود عالقة ذات داللة إحصائية بين قيم الثباتية المتنبئة وقيم الثباتية المقاسة بالجهاز. إن العالقة االيجابية بين قيم قوة عزم تثبيت الزرعة، وبين قيم ثباتية الزرعات المقاسة قد تساعد األطباء على التنبؤ االستنتاجات: هناك عالقة ارتباط معتدلة بالثباتية االبتدائية لزرعة االسنان خالل عملية الجراحة، التي قد تترافق مع معدالت بقاء ونجاح الزرعات. . tmostell وقيم الثباتية المقاسة بجهاز راح الحسية في تقرير الثبات األساسي للزرعةدقة الجنوعا ما بين ma'an.doc j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 54 j bagh college dentistry vol. 27(1), march 2015 an evaluation of an evaluation of the influence of different finishing lines on the fracture strength of full contour zirconia cad/cam and heat press all-ceramic crowns. ahmed ibrahim khalaf al-joboury, b.d.s. (1) ma’an rasheed zakaria, b.d.s., m.s., ph.d. (2) abstract background: one of the major problems of all ceramic restorations is their probable fracture against the occlusal forces. the objective of this in vitro study was to evaluate the effect of two gingival finishing lines (90°shoulder and deep chamfer) on the fracture resistance of full contour cad/cam and heat press all-ceramic crowns. materials and methods: thirty two maxillary first premolars were prepared to receive full contour cad/cam (zolid) and heat press (cergo kiss) ceramic crowns using a special paralleling device (parallel-a-prep). the teeth were divided into four groups according to the type of finishing line prepared. each crown was cemented to its corresponding tooth using self-etch, self-adhesive dual cure resin cement. following storage for 1 week in distilled water at room temperature, teeth were subjected to thermal cycling. fracture resistance was determined using a universal testing machine, and the samples were investigated microscopically from the point of view of the origin of the failure. statistical analysis was carried out using the one-way anova and student’s t-tests. results: the mean values of fracture resistance for cad/cam group showed 1367.250+178.967 n for 90°shoulder margins and 1109.250+252.455 n for the deep chamfer margins. anova test results revealed high significance between and within the groups. the mean values of fracture resistance for heat press group were 548.562+272.471 n for 90°shoulder margins and 247.912+96.995 n for the deep chamfer margins expressing statistical significance. conclusions: the results of this study pointed to a relationship between the design of the cervical finishing line and the fracture strength of the full cad/cam crowns and the full heat press ceramic crowns. both 90° shoulder and deep chamfer finishing lines are suitable for zolid crowns while the 90° shoulder is more suitable for the cergo kiss crowns than the deep chamfer preparation. key words: full contour, all-ceramic crowns, cad/cam, heat press, fracture strength. (j bagh coll dentistry 2015; 27(1):54-62). introduction the increasing demand for esthetics in the posterior region of the mouth and environmental concerns about restorations containing metal were behind the evolution of new techniques for fabrication of posterior inlays, onlays, and crowns. (1) such restorations have several advantages, including lifelike appearance, biocompatibility,(2) wear resistance, and color stability.(3) however, their drawbacks include brittleness, especially glass or feldspathic ceramics,(4) susceptibility to fracture, causing excessive wear to opposing dentition, requiring more involved tooth reduction, and being technique-sensitive.(5) when non-metallic crowns undergo fracture, the fracture typically originates from flaws or defects in the intaglio surfaces. subcritical crack growth follows, which is enhanced in the aqueous environment. (6) ceramic materials are particularly susceptible to the tensile stresses, and mechanical resistance is also strongly influenced by the presence of superficial flaws and internal voids. such defects may represent the sites of crack initiation. (1)master student, department of conservative dentistry, college of dentistry, university of baghdad. (2)professor in fixed prosthodontics & occlusion, department of conservative dentistry, college of dentistry, university of baghdad. superficial flaws and internal voids. such defects may represent the sites of crack initiation. this phenomenon may be influenced by different factors such as marginal design of the restoration, residual processing stress, magnitude and direction and frequency of the applied load, elastic modulus of the restoration components, restoration–cement interfacial defects, and oral environmental effects.(7) the introduction of computer-aided design / computer-aided manufacturing (cad/cam) technology in dentistry enabled dentists to use new treatment modalities and changed the design and application limits of all-ceramic restorations as the demand for esthetics in the posterior region of the mouth has increased. recent zirconia restorations have provided functional, biocompatible, and esthetic demands (8) with superior mechanical properties than conventional porcelain restorations. (9) the strength of an allceramic restoration depends not only on the fracture resistance of the material, but also on a suitable preparation design with adequate material thickness. (10) all ceramic restorations using the pressed ceramic technique have shown better fracture toughness values than those of the conventional porcelain veneering technique. (11) it was proposed that both shoulder, chamfer and deep j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 55 chamfer finishing lines are considered to be adequate for the fracture strength of all-ceramic restorations (12), but it was found that the fracture strength of zirconia crowns prepared with chamfer finish line (0.9-1.2 mm) was greater than those prepared with 1.2 mm rounded end shoulder and 1.2mm shoulder finish line. (13) on the other hand, it had been suggested that a shoulder margin caused a greater fracture resistance than deep chamfer and chamfer margins. (14) materials and methods thirty-two sound and crack free maxillary 1stpremolars extracted for orthodontic treatment with no evidence of caries or restorations were collected from patients of ages ranging between 15 to 20 years. both calculus deposits and residual periodontal tissues were removed by ultrasonic scaler. all teeth were examined under optical microscope at x40 (olympus, japan) to detect cracks before including them in the study. the teeth were kept hydrated in distilled water as this storage solution does not seem to alter dentine permeability.(15) the storage solution was changed every one week and the teeth were stored at 4°c in a refrigerator.(16) to simulate periodontal ligament, root surfaces were dipped into molten wax in a dipping wax machine (bego, germany) by using a dental surveyor (bego, germany) to which the tooth was attached and dipped to a point 2.0 mm apical to the cementoenamel junction, resulting in a 0.2 to 0.3 mm thick wax layer.(17) then all teeth were embedded along their long axes using a surveyor in mixed cold cure acrylic (at dough stage) (triplex®srcold, ivoclar vivadent ag, schaan, liechtenstein) 2.0 mm below the cementoenamel junction using a custom-made split metal mold (30 mm diameter and 30 mm height).(18) after the first signs of polymerization, teeth were removed from the acrylic blocks along their long axes using the surveyor, and the wax was removed from root surfaces by using a surgical blade. an additional silicone-based light body impression material (aquasil ultra lv, dentsply, usa) was injected into the acrylic resin blocks using a mixing gun, and the teeth were reinserted into the resin cylinders. a standardized silicone layer that simulated periodontal ligament was created.(19) to standardize teeth preparation, a vacuum pressed polyethylene plastic template (biostar, scheu-dental, germany) was fabricated for each tooth before preparation using a vacuum forming machine (biostar, scheu-dental, germany). parallelometer (parallel.a.prep®, dentatus usa, ny, usa) was used to control the handpiece orientation during tooth preparation. the holding tray of the parallel.a.prep® was secured to one side of a custom-made metal maxillary jaw with heavy body condensation silicon. the special horizontal metal template of the parallelometer was adjusted to ensure standardized horizontal occlusal plane free from any tilting during tooth preparation. then, the metal rod of the parallelometer was used to standardize the long axis of the attached bur to the high-speed handpiece with the tooth. the metal rod was aligned at the middle line of a plastic protractor resembling the long axis of tooth(8) (fig.1). then maxillary first premolars were prepared using a high speed handpiece (topair 796, w&h, austria) with air-water coolant and using diamond burs for deep chamfer (lot no. 746546, komet, germany) and 90° shoulder (lot no. 709449, komet, germany) finishing lines (fig.2). figure 1: the metal rod of the parallelometer device is aligned at the middle line of the protractor. figure 2. the handpiece controlled by the parallelometer is aligned parallel to the tooth by aid of the protractor. the axial taper angle used in the present study was 6 degrees.(20) therefore, to achieve a 6j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 56 degree axial taper preparation, the high speed handpiece was secured to the apparatus so that the attached tapered diamond bur was oriented at a 3-degree angle to the vertical axis of the tooth. this, in addition to the 3-degree taper of the tapered bur, resulted in a total axial taper angle of 6 degrees corresponding to a convergence angle of 12 degrees (fig.3 a & b). figure 3a. the metal tip of the parallellometer is set at 3 degrees. figure 3b. the handpiece orientation during tooth preparation controlled by the parallellometer device to ensure the same convergence angle for all preparations. after the completion of axial preparation, the gingival finishing line was 1 mm for deep chamfer and 1.2 mm for 90° shoulder measured using a digital caliper (prokit's industries co., ltd.,taiwan). then the occlusal surface of the tooth was cut flat, a pencil was used to mark the prepared tooth 4 mm above the margin and the occlusal surface was flattened with a diamond wheel (komet, germany) to the marked line which resulted in a preparation with 4.0 mm height from the gingival finishing line.(21) after that, a plastic template coping was placed on each prepared tooth and a hole was made against each axial wall so that a periodontal probe was inserted through each hole to ensure standardized amount of teeth preparation. those series of reductions resulted in a standardized teeth preparation with 6-degree axial taper, a 1 mm deep chamfer and 1.2 mm shoulder margin, and total preparation height of 4.0 mm. prepared teeth were assigned into four groups (n = 8) according to their type of preparation and type of crown received as follows: 1. group i: shoulder finishing line with full contour zirconia cad/cam crowns. 2. group ii: shoulder finishing line with full contour heat press crowns. 3. group iii: deep chamfer finishing line with zirconia full contour cad/cam crowns. 4. group iv: deep chamfer finishing line with full contour heat press crowns. heat press group manufacturing (cergo kiss, degudent, hanau-wolfgang, germany) stone dies were constructed for the prepared teeth of groups ii and iv using heavy and light body polyvinylsiloxane silicone impression material (zeta plus, zhermack, italy) which were poured with type iv dental stone (elite®rock, zhermack, italy). in order to standardize the wax design, wax patterns were made on the stone dies utilizing the plastic templates and were checked using a wax gauge (aesculap, germany). three layers of die spacer were painted on each die 0.5 mm short of the preparation to achieve a thickness of approximately 45µm of internal relief.(22) each wax pattern was sprued (8mm gauge and 6 mm length) following the manufacturer's instructions. the muffle ring was placed on the muffle former; the investment material (cergo fit speed investment) was mixed by using auto mixer device (degudent, hanau-wolfgang, germany) followed by light vibration of the muffle to avoid bubbles formation until all objects were completely covered with the investment. then the muffle was left to rest until the investment had set. after a setting period of 15 minutes for the investment, the muffle was placed in the preheating oven together with the aluminum oxide pressing die. the muffle was heated from room temperature to 850°c. after activating the pressing program, the muffle was removed from the pre-heating oven once the starting temperature of 700°c had been reached ceramic pellets were placed in the muffle channel and the pressing die was positioned. immediately, the muffle was placed in the pressing oven and the pressing program was started. once the pressing process was completed (after approximately 45 minutes), the muffle was j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 57 removed from the pressing oven and allowed to slowly cool to room temperature. by indicating the position of the pressed objects, a deep cut into the investment compound was made using a diamond-covered and sintered large carbide disc. the part of the muffle containing the aluminium oxide pressing die was separated from the rest of the muffle by turning in opposite directions. a jet polisher (kavo, germany) was used to remove the investment all the way to the pressed objects. once the objects were visible, abrading across the area using al2o3 (50 µm/70 mesh, renfert, germany) at reduced pressure (2 bars) was continued; then the pressing die was cleaned by rinsing with distilled water. each sprue was cut using a fine diamond disc while holding the ceramic crown with a wet sponge to avoid over heating of the crown. attachment point of the sprue was removed with a fine diamond bur at low speed using a straight handpiece attached to an inlab micromotor (marathon, korea) with no pressure under water cooling. each pressed ceramic crown was carefully fitted on its die. any interfering irregularities were checked by covering the die with a thin layer of a stain paste, then the crown was placed again on its die and the investing irregularities were carefully removed with a fine diamond bur from the inside of the crown under water cooling. a steam cleaner was used to clean all heat pressed crowns following the manufacturer's instructions. a dial caliper was used to measure and check the thickness of each wall of each completed crown. cad/cam group manufacturing (zolid, ceramill systems, amann girrbach gmbh, pforzheim, germany) each tooth block was placed into a special plastic tray (fabricated by the company to grasp the tooth block to be scanned) and the whole assembly was secured in the model holder of the surveyor. then the teeth were scanned by using scanning device of ceramill inlab, with the help of the ceramill 3d inlab software; threedimensional images were displayed on the computer monitor so that all surfaces and finishing lines were clearly shown. the external and internal margins of each crown and the path of insertion were determined. a minimum wall thickness of (1mm for deep chamfer and 1.2 mm for 90° shoulder), taking care that the cement gap should have 0.05 mm thickness, starting at 1 mm from the margin was determined. finally the crown was seen in its final design in the monitor. after applying the information for the design to the milling center in software, a suitable blank (height and size) was selected from the blank loaded library of the cad/cam system. then the zolid block was placed in the blank holder and fixed with screws by a screw key, and the milling process was started. all those steps were done following the manufacturer instructions of ceramill inlab cad/cam system. after the milling procedure had ended, the blank was removed from the milling machine and the crown was separated from the blank with a fissure bur in a straight handpiece. the crown was given its individual color by immersing it in the dye solution. the sintering was carried out in the ceramill therm hightemperature furnace 1500°c for 9 hours to complete sintering. cementation internal surfaces of all zolid crowns were gritetched for 5 seconds with 50 μm al2o3 powder at 80 psi. and the internal surfaces of the cergo kiss crowns were etched with hydrofluoric acid for 20 seconds following the manufacturers' instructions. then all crowns of the four groups were cleaned using distilled water in an ultrasonic cleaner for 60 seconds followed by drying with compressed oil-free air. all crowns were cemented on their respective teeth in the following manner: each crown was filled with self-adhesive dual-cure resin cement (set pp, sdi ltd., australia) and was seated on its tooth using finger pressure. excess cement was removed using a sponge pellet leaving a minimal amount of excess for light curing process. each cemented crown was vertically loaded with a 5 kg static load applied on the vertical arm of the dental surveyor to avoid any internal cement gaps.(14) light polymerization (astralis 5, ivoclar vivadent ag, schaan, liechtenstein) was carried out for 20 sec. per surface following the manufacturer’s recommendations. then each cemented crown was kept under the load for 5 minutes.(8) one hour after cementation, specimens were stored in distilled water at room temperature for one week (8), and then subjected to 500 thermal cycles between 5-55°c with dwell time of 30 seconds.(16) testing procedure each tooth with its cemented crown was removed from the storage container, secured in a mounting jig and subjected to testing in a universal testing machine (tinius olsen h50kt, uk) (fig.4). the loading piston was a vertically movable rod with a semispherical head (5 mm in j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 58 diameter stainless steel ball) applied at the center of the occlusal surface along the long axis of the cemented crowns with a crosshead speed of 0.5 mm/min until fracture occurred.(16, 23-25) a piece of 1 mm thick rubber layer was placed between the loading tip and the crown in order to provide for homogenous stress distribution.(16) after test completion, each crown was examined by a magnifying lens (×10) from the point of view of the origin of the failure (crack) in order to determine the mode of fracture which was classified according to the categories described by burke and watts.(26) the fractured crowns were further inspected by an optical microscope (×40, olympus, japan) supplied with a digital camera (14.1 mega pixels, sony, japan). results the means and standard deviations of fracture strength with minimum and maximum values calculated for each group are shown in (table 1). the results showed that the lowest mean of fracture strength was scored by group iv while the highest mean belonged to group i .further analysis of groups was performed using student’s t-test to examine the difference between the groups (table 2) which showed statistical significance between groups (gi & giii, g ii & giv). on the other hand, highly significance occurred between the remaining groups. examination of the mode of fracture of the tested zolid cad/cam crowns) revealed (100%) minimal fracture related to both types of cervical finishing line preparations (table 3 & fig.5). the cergo kiss heat press ceramic crowns revealed minimum fracture modes (37.5%) with 90º shoulder preparation and (50%) with deep chamfer type(table 4). more than half of crown was lost with the deep chamfer preparation (37.5%) in comparison to (25%) with 90ºshoulder preparation (fig.6). the percentage of severe crown fracture (12.5%) was equal for both types of finishing line designs. figure 4. chamber of the loading device where load is applied at 90° to the occlusal surface of the tooth. table 1: the mean load at fracture and standard deviation for zolid and cergo kiss crowns. technique method type of finishing line no. mean (newtons) minim. max. standard deviation (sd) cad/cam zoild 90°shoulder group i 8 1367.250 1027 1608 ±178.967 deep chamfer group iii 8 1109.250 623 1331 ±252.455 heat press cergo kiss 90°shoulder group ii 8 548.562 188.3 923 ±272.471 deep chamfer group iv 8 247.912 103.3 411.5 ±96.995 table 2: t-test for quality of means and comparison of significance between the groups. compared groups df t-value p-value sig. g i vs g iii 14 2.358 0.03 s g i vs g ii 14 7.103 0.00 hs g i vs g iv 14 15.553 0.00 hs g iii vs g ii 14 4.269 0.00 hs g iii vs g iv 14 9.008 0.00 hs g ii vs g iv 14 2.940 0.01 s j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 59 table 3: modes of fracture of zolid groups. zolid minim. fracture n (%) (crack) less than half of crown lost n (%) more than half of crown lost n (%) severe fracture of tooth and/or crown n (%) total 90° shoulder 8(100%) 0(0%) 0(0%) 0(0%) 8(100%) deep chamfer 8(100%) 0(0%) 0(0%) 0(0%) 8(100%) table 4: modes of fracture of cergo kiss groups. cergo kiss minim. fracture n (%) (or crack) less than half of crown lost n (%) more than half of crown lost n (%) severe fracture of tooth and/or crown n (%) total 90° shoulder 3(37.5%) 2(25%) 2(25%) 1(12.5%) 8(100%) deep chamfer 4(50%) 0(0%) 3(37.5%) 1(12.5%) 8(100%) figure 5(a). failure type of a zolid crown after fracture test. (b) optical microscope image of fractured surface of a zolid crown (x40 magnification). figure 6(a). failure type of a cergo kiss crown after fracture test. (b) optical microscope image of fractured surface of a cergo kiss crown (x40 magnification). discussion the supporting die structure has been reported to affect the fracture strength of all-ceramic restorations because of the influence of the elastic modulus of the supporting die. using supporting die structures that have lower elastic moduli are suitable for fracture strength tests in order to accurately reflect clinical conditions.(27) according to that, natural freshly extracted teeth were chosen in this study to be prepared to receive the tested crowns instead of stainless, epoxy resin and composite resin dies which don’t reproduce the real force distribution as that occurring on crowns cemented on natural human teeth.(28) on the other hand, dentin exhibits a lower modulus of elasticity than stainless steel and as a consequence, the inner crown surface shows a greater shear stress every time the tooth is subjected to deformation. (8, 16, 29) a thin layer of condensation silicon was used in this study to resemble the periodontal ligament thus acting as a cushion to resemble the clinical condition and to avoid the external reinforcement of the root structure by the rigid acrylic resin.(30 32) the parallel-a-prep device was used to prepare the teeth since it could maintain the cutting axis exactly at the angle selected by controlling the taper precisely by the taper of the cutting bur used. this helped that all axial walls were maintained parallel thus preventing all undercuts and as a result all prepared teeth exhibited uniform and minimal tapers of 6 degrees.(8) since a tapered bur imparts an inclination of 2-3 degrees to any tooth surface it cuts if the shank of the bur was held parallel to the intended path of insertion of preparation, then by using a protractor the degree of taper of 6 degrees was obtained by tilting the bur to a tapered angle of 3 degrees.(21) the dual-cure resin cement was used as it has been widely indicated for luting crowns.(33-35) the polymerization reaction of dual-cure resin cement is chemically and photo-initiated which ensures higher conversion rate of curing, leading to better j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 60 mechanical properties and such cements promoted more reliable micro-shear bond strength and micro-hardness values than the flowable resin for cementation of all ceramic restorations.(36) in order to evaluate the effects of water storage and thermo cycling on the fracture resistance of crown specimens, all specimens in this study were stored in distilled water for 7 days and were subjected to 500 cycles in water between 5°c and 55°c before testing their fracture resistance.(8,16) the use of 5 mm in diameter stainless steel ball was to simulate the contact pressure of the crown by opposing cusps as the contact pressure was influenced by the ratio of the elastic modulus of the dental porcelain to the elastic modulus of the loading ball, and by the radius of the loading ball. placing a piece of rubber layer between the load applicator and tested crown was to act as stress breaker to prevent cone cracking, and to simulate the cushion effect of food between opposing teeth.(6,8,18,25) in this study, the superior mechanical properties of zolid full contour zirconia crowns can be explained to be due to the finer grain size and the tetragonal-monoclinic transformation toughening mechanism which leads to compressive stresses in the material and results in reduced crack propagation which contribute to the improved fracture resistance of the zirconia crowns. however, some studies reported that the combination of ageing and phase transformation has been detrimental for fatigue properties of ytzp.(37,38) the high fracture strength values exhibited by gi crowns can be referred to the occlusal forces borne by circumferential 90° shoulder and consequently less stress concentration occurring on the axial walls compared to other preparation designs.(14,25) in this study, the variation in the statistical significance between the fracture resistance of the cergo kiss heat press ceramic and the zolid zirconia cad/cam systems can be attributed to the structural properties of this type of heat press leucite reinforced ceramic. it has been reported that an increase of crystalline content of a glassceramic is accompanied with an increase of the strength and fracture toughness due to the fine dispersion of crystals. the main difference between heat pressed leucite-based cores and the lithium-based core ceramics lies in that the leucite-based type has its crystals, which are dispersed in a glassy matrix of an amount and sizes enough to raise the magnitude of toughness to a greater level compared to the lithium-based core ceramics.(37) in the case of lithium disilicate containing pressable ceramics, the difference in mean grain length has no measurable effect on the strength and fracture toughness. conversely, the minimal variations of the grain size shape and orientation in the glass-infiltrated alumina reinforced ceramics strongly affects the strength and fracture toughness of these ceramics. from a clinical standpoint, the alignment of elongated grains parallel to the surface is preferred over perpendicular or random alignment, as the greatest resistance to crack propagation through the core material is achieved.(6) however, the techniques of fabrication of allceramic lithium disilicate restorations such as empress2 (ivoclar vivadent ag, schaan, liechtenstein) and the in-ceram alumina, slip casting + dry pressing (vita zahnfabrik gmbh, germany) don’t seem to take into account such issue and the orientation of the crystals is most likely due to coincidental factors which led to a decrease in their fracture resistance when compared to the leucite-reinforced heat press ceramics, a reason that made manufacturers to enforce them with zirconium oxide.(6) this was supported by a study in which nearly all conventionally veneered crowns failed during chewing simulation;whereas crowns with cad/cam manufactured veneeres with lithium disilicate ceramic (ipsemax cad, ivoclar vivadent ag, schaan, liechtenstein) displayed ultimate loads to failure.(39) under the circumstances of this study, the following conclusions were drawn: 1. the highest fracture strength mean values were represented by the zirconia cad/cam full crowns cemented on teeth which received a 90º shoulder preparation. 2. highly statistical significance was located between the zirconia cad/cam full crowns and the heat press full ceramic crowns regarding the 90º shoulder and the deep chamfer cervical margins. 3. the 90º shoulder and the deep chamfer preparations are considered suitable for the zirconia cad/cam full crowns in the premolar and molar regions. 4. the 90º shoulder preparation is considered more suitable for the heat press full ceramic crowns in the premolar region since the deep chamfer crowns exhibited lower fracture strength values than the average biting force in that region. 5. both types of all-ceramic crowns can be considered as promising prosthodontic alternatives to metal-ceramic crowns and veneered all-ceramic crowns since dental technicians' errors can be surpassed in addition to their biocompatible and esthetic properties. j bagh college dentistry vol. 27(1), march 2015 an evaluation of restorative dentistry 61 acknowledgement the authors greatly thank assist. prof. dr. wisam alrawi, college of dentistry, university of ann arbor, usa for his efforts in providing the parallel.a.prep instrument. references 1. tsitrou ea, northeast se, van noort r. evaluation of the marginal fit of three margin designs of resin composite crowns using cad/cam. j dent 2007; 35:68-73. 2. sjogren g, sletten g, dahl je. cytotoxicity of dental alloys, metals, and ceramics assessed by millipore filter, agar overlay, and mtt tests. j prosthet dent 2000; 84:229-36. 3. 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dos santos ct, paulillo lams:. knoop hardness and effectiveness of dualcured luting systems and flowable resin to bond leucitereinforced ceramic to enamel. j prosthodont 2013; 22:54-8. 37. chevalier j, grémillard l, virkar av, clarke dr. the tetragonal-monoclinic transformation in zirconia: lessons learned and future trends. j am ceram soc 2009; 92:1901–20. 38. kirsten a, begand s, oberbach t, telle r, fischer h. subcritical crack growth behavior of dispersion oxide ceramics. j biomed mater res braz appl biomater 2010; 95:202-6. 39. della bona a, mecholsky jj jr., anusavice kj. fracture behavior of lithia disilicate and leucite based crowns. dent mater 2004; 20:956-62. j bagh college dentistry vol. 28(4), december 2016 assessment of oral diagnosis 77 assessment of cysts and cystic-like lesions of the jaws and their effect on adjacent structures by using cone beam computed tomography (cbct) thair abdul lateef, b.d.s., h.d.d., f.i.b.m.s. (a) zainab h. al-ghurabi, b.d.s., m.sc. (b) huda moutaz ismael, b.d.s., m.sc. (c) muthanna kamal ali, b.d.s., m.sc. (b) abstract background: preoperative radiographical assessment of the maxillofacial lesions is of a great importance in guiding the surgeon during surgical procedure in reducing post-operative complications. this study highlighted the application of cbct scan in the assessment of maxillofacial cystic and cystic like lesions as a part of advanced radiology materials and methods: a total of 20 patients (15 males and 5 females) participated in this prospective study. cbct scan (kodak 9500 cbct) with (dicom) software utilized to perform scanning to all patients in order to assess lesion extension, morphological features and it’s relation to the adjacent vital structures. results: in this study, the total cystic and cystic like lesions involving the maxilla and mandible were (20) lesions. statistical analysis of the collected data showed no significant differences between the radiographical records and surgical findings regarding diagnostic accuracy of the lesions. conclusion: the validity of the cbct in the assessment of maxillofacial cystic and cystic like lesions was similar to the surgical findings regarding lesion extension, expansion, perforation of buccal/or lingual plates, and relation to the adjacent vital structures. key words: cbct, jaw, cystic lesion. (j bagh coll dentistry 2016; 28(4):77-81) introduction cysts and cystic like lesions in the maxilla and mandible could be divided into odontogenic and non-odontogenic lesions, most of lesions are benign but sometimes changes may occur (1,2). as a general view, the distribution of the jaw cysts was as follows: radicular cysts 56%, dentigerous cysts 17%, nasopalatine duct cysts 13%, odontogenic keratocysts 11%, globulomaxillary cysts 2.3%, traumatic bone cysts 1.0%, and eruption cysts 0.7% (3). there are many important information that should be known by the surgeon before the operation, like size of the lesion and its extension, root displacement and resorption, expansion of cortical plates (buccal and/or lingual or plates) and its relation to the adjacent structures (4, 5), all these diagnostic information could not be obtained by clinical examination and twodimensional radiographic images like periapical and panoramic images (6, 7). multidetector computed tomography (mdct) introduces high benefits in maxillofacial region since it supplies the surgeon with high resolution and multiple projections with very thin slice (8,9). (a) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (b) lecturer. department of oral diagnosis, college of dentistry, university of baghdad. (c)assistant lecturer, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. nowadays, cbct appeared to change the view and diagnosis way of the oral and maxillofacial surgeons by providing an accurate evaluation andtreatment planning prior to operation. cbct.a new imaging modality, introduces a three-dimensional image in addition to three multiplanar views, coronal, sagittal and axial in one rotation only with low dose and simpler technique than mdct (10,11). many studies proved that the accuracy of cbct in diagnosis was compared or higher than multi-slice ct, because it has isotropic voxel with high resolution and small voxel less than 0.3mm, and it could produce 160 to 360 slice with high resolution compared with mdct (12-14). this study relied on evaluation of cbct and on intraoperative findings to compare the accuracy of cbct outcomes. the purpose of the present study was: to evaluate the accuracy of cbct in the assessment of cysts and cystic like lesions in the jaws in comparison with the surgical findings as a gold standard. materials and methods a total of 20 patients (15 males and 5 females), aged (10-60) years old participated in this prospective study. all patients were referred for preoperative radiographic assessment (cbct scanning) of untreated pathology (cysts and cystic like lesion) after clinical provisional diagnosis and j bagh college dentistry vol. 28(4), december 2016 assessment of oral diagnosis 78 aspiration of lesions in the specialist health center of al-sadder city. this study established by communication between radiographical and surgical team. the scanning were performed by using kodak 9500 cbct ( french origin), the kv was 90, ma10 and scanning time was 10 sec. voxel size 0.3mm with( dicom ) software on a multiplanar reconstruction window in which the axial, coronal and sagittal plane could be visualized in addition to three-dimensional image. inclusion criteria  patients age range from (10-60) years old.  well circumscribed radiolucency involving maxilla and/or mandible.  lesion with clinical and radiographical provisional diagnosis of being a cyst or cystic like lesion. exclusion criteria  ill-defined border of a large radiolucency involving maxilla and/or mandible with extension to the soft tissue.  medically compromised patients who are classified by american society of anesthesiologist as being class iii or more. information required from the surgeon who performed the surgical removal of the cystic and cystic like lesions included the following points:  accuracy of the lesions extent  perforation of buccal/and or lingual cortical plate  resorption of the adjacent teeth roots  expansion  displacement of inferior alveolar nerve  maxillary sinus involvement image analysis preoperative and postoperative cbct images were completed and reviewed for each patient, three-dimensional image initially utilized to make visualization of the lesion as in figure (1). figure 1: three-dimensional image of pathological lesion involving the mandible with displacement of teeth and resorption of their roots, which was shown to be odontogenic keratocyst (okc) with histopathological examination. coronal, axial and sagittal planes were utilized to make complete assessment of the lesion dimensions and characteristics as shown in figure (2). figure 2: cbct scan (sagittal view) demonstrated the size and extension of the lesion involving the mandible with displacement of the canine tooth toward the lower border of the mandible. outcome measures:  assess the extension of the lesion and its effect on adjacent structures and teeth. it should be mentioned that lesion extension recorded in two directions perpendicular to each other as (mesio-distal and superio-inferior directions).  record and assess the density of the lesion content, which may help the surgeon to make provisional diagnosis.  intra operative findings and histopathological examination were j bagh college dentistry vol. 28(4), december 2016 assessment of oral diagnosis 79 recorded and compared with the radiographic assessment of the lesions. informed consent was obtained from all patients who were informed about the aim and method of the study. results this study included 20 patients presenting with cystic and cystic like lesions equally distributed in both jaws, (10) lesions involved the maxilla and (10) were in the mandible. of the total 20 cases, histopathological examination revealed 3 radicular cysts (15%), 6 dentigerous cysts (30%), 3 lateral periodontal cysts (20%), 4 odontogenic keratocysts (20%), 2 residual cysts (10%), 1 unicystic ameloblastoma (5%) and 1 periapical granuloma (5%) as shown in table (1). table 1: descriptive statistics of histopatholoical distribution of the lesions histopathological distribution of the lesions no. percentage radicular cyst 3 15% dentigerous cyst 6 30% lateral periodontal cyst 3 15% okc 4 20% residual cyst 2 10% unicystic ameloblastoma 1 5% periapical granuloma 1 5% total 20 100% statistical analyses were established depending on accurate assessment of cbct, intraoperative findings and histopathological reports of each case. percentage of agreement was used to analyze the data as shown in table (2). according to gray scale value in cbct scan, there were 8 of 20 cases (fluid-semifluid radiodensity), 11 combined (fluid-semisolid) and 1(solid radiodensity) as demonstrated in table (3). table 2: statistical analysis of radiographical data versus intra-operative data with percentage of agreement for each record comparison of the radiographical data with intra-operative findings radiographical data intra-operative findings percentage of agreement perforation of buccal and/or lingual cortical plate 11/20 (55%) 13/20 (65%) 84.61% expansion 14/20 (70%) 14/20 (70%) 100% resorption of the adjacent teeth roots 11/20 (55%) 11/20 (55%) 100% displacement of inferior alveolar dental nerve 1/20 (5%) 1/20 (5%) 100% maxillary sinus involvement 11/20 (55%) 13/20 (65%) 100% table 3: statistical analysis of radiographical data versus histological findings of the lesions comparison of the radiographical data with histological records radiographical data according to the gray scale value histological records percentage of agreement (%) density of intra lesional contents 8/20 fluid-semifluid (40%) 19/20 fluid-semifluid (cystic lesions) (95%) 42.10% 1/20 solid (5%) 1/20 solid (granuloma) (5%) 100% discussion the new advances in maxillofacial radiology aided in accurate preoperative assessment of the maxillofacial lesions and also assist in optimizing planning for surgical procedures. several intraoral and extra oral radiographic techniques such as periapical, occlusal, and panoramic views were available but these techniques have several limitations including two-dimensional image of three dimensional subject, insufficient j bagh college dentistry vol. 28(4), december 2016 assessment of oral diagnosis 80 visualization, superimposition, and distortion, which lead to underestimated assessment of the lesion. recently the introduction of cbct scan solves the drawbacks of the old radiological methods (15). in this study, comparing the radiographic data to intraoperative findings of the lesions showed that cbct was an effective method in radiographic diagnostic assessment of the cyst and cystic like lesions. it revealed detailed information about lesions location, extension and relation to the adjacent vital structures, which aid the surgeon in planning surgery in a less aggressive manner avoiding damage to vital structures with subsequent decrease of complications and in a relatively shorter time. this was also confirmed by nakagawa et al. (16) who mentioned that accurate preoperative radiological examination of odontogenic lesions avoids surgical complications, and reduces surgical stress (16). cbct scan showed 100% diagnostic accuracy regarding lesions extension, buccal and/or lingual expansion, resorption of the adjacent teeth roots and relation to the adjacent anatomic structures. this is achieved by comparing the preoperative radiographical assessment of the lesions with intraoperative findings as demonstrated in table (2). radiographically, there were 11/20 (55%) cases showed perforation of buccal and/or lingual cortical plate while intraoperative findings revealed 13/20 (65%) cases of perforation. this could be attributed to surgical factor including accidental removal of the thin bony spicules during preparation of the surgical access to the lesion or radioraphical factor including insufficient percentage of minerals loss to be appeared as a defect on the radiograph. assessment of the lesion radiodensity by recording the gray scale value in cbct scan had an important role in differentiation of cystic lesion from granuloma. this was confirmed by guo et al. (17)who stated that cbct scan is a helpful tool in the differential diagnosis between cysts and granulomas when the apical lesion have a minimum average diameter of 5 mm (17). similarly, shekhar and shashikala (18) reported that cbct scan may be regarded as a more accurate method in differentiation between a solid from a fluid-filled large periapical lesion or cavity as compared to conventional intra-oral periapical radiographs (18). in this study, preoperative cbct scan showed high sensitivity in predicting the risk of postoperative paresthesia following surgical removal of cystic lesion in close proximity to the inferior alveolar canal. this is in agreement with krennmair and lenglinger (19) who reported that cbct is superior to conventional ct in detecting cortical bone involvement and delineating the mandibular canal (19). from these results, we found that, cbct findings might predict histologic results more accurately. also it has benefit to the patient including less time, cost, and radiation dose compared to more sophisticated ct scan imaging technique. also it guides the surgeon in the surgical procedure in a more predictable manner. references 1. robert js, helen mk, david pn, alan gl. cysts and cystic lesions of the mandible: clinical and radiologichistopathologic review. radiographics 1999; 19:1107– 24. 2. weber al. mandible. in: som pm (ed). head and neck imaging. 2nd ed. vol. 1. st louis: mosby–year book; 1991. pp. 399–420. 3. killey hc, kay lw. an analysis of 471 benign cystic lesions of the jaws. int surg 1966; 46: 540–5. 4. joseph ar. odontogenic cysts, odontogenic tumors, fibroosseous, and giant cell lesions of the jaws. mod pathol 2002; 15: 331–41. 5. teresa am, christopher cb, fang q. a retrospective review of treatment of the odontogenic keratocyst. j oral maxillofac surg 2005; 63: 635–9. 6. trope m, pettigrew j, petras j, barnett f, tronstad l. differentiation of radicular cyst and granulomas using computerized tomography. dent traumatol 1989; 5: 69–72. 7. silva ma, wolf u, heinicke f, bumann a, visser h, hirsche e. cone-beam computed tomography for routine orthodontic treatment planning: a radiation dose evaluation. am j orthod dentofac orthop 2008; 133:1–5. 8. mortele kj, mctavish j, ros pr. current techniques of computed tomography. helical ct, multidetector ct, and 3d reconstruction. clin liver dis 2002; 6: 29–52. 9. lopes pm, moreira cr, perrella a, antunes jl, cavalcanti mg. 3d volume rendering maxillofacial analysis of angular measurements by multislice ct. oral surg oral med oral pathol oral radiol endod 2008;105: 224–30. 10. nakagawa y, kobayashi k, ishii h, asada k, mishima k. preoperative application of limited cone beam computerized tomography as an assessment tool before minor oral surgery. int j oral maxillofac surg 2002; 31:322–7. 11. gaia bf, sales mao, perrella a, fenyo-pereira m, cavalcanti mgp. comparison between cone-beam and multislice computed tomography for identification of simulated bone lesions. braz oral res 2011; 25: 362– 8. 12. schulze d, heiland m, thurmann h, adam g. radiation exposure during midfacial imaging using 4 and 16-slice computed tomography, cone beam computed tomography systems and conventional radiography. dentomaxillofac radiol 2004; 33(2): 83– 6. 13. gibbs sj. effective dose equivalent and effective dose: comparison for common projections in oral and maxillofacial radiology. oral surg oral med oral pathol oral radiol endod 2000; 90(4): 538–45. http://www.ncbi.nlm.nih.gov/pubmed/?term=guo%20j%5bauthor%5d&cauthor=true&cauthor_uid=24238434 j bagh college dentistry vol. 28(4), december 2016 assessment of oral diagnosis 81 14. kobayashi k, shimoda s, nakagawa y, yamamoto a. accuracy in measurement of distance using limited cone-beam computerized tomography. int j oral maxillofac implants 2004; 19(2): 228–31 15. shweel m, kamer m, el-shamanhory af. a comparative study of cone-beam ct and multidetector ct in the preoperative assessment of odontogenic cysts and tumors. egy j radiol nuclear med 2013; 44: 23–32. 16. nakagawa y, kobayashi k, ishii h, asada k, mishima k. preoperative application of limited cone beam computerized tomography as an assessment tool before minor oral surgery. int j oral maxillofac surg 2002; 31: 322–7. 17. guo j, simon jh, sedghizadeh p, soliman on, chapman t, enciso r. evaluation of the reliability and accuracy of using cone-beam computed tomography for diagnosing periapical cysts from granulomas. j endod 2013; 12:1485-90. 18. shekhar v, shashikala k. cone beam computed tomography evaluation of the diagnosis, treatment planning, and long-term follow up of large periapical lesions treated by endodontic surgery: two case reports. case reports in dentistry 2013; article id: 564392: 1-12. 19. krennmair g, lenglinger f. imaging of mandibular cysts with a dental computed tomography software program. int j oral maxillofac surg 1995; 24: 48. http://www.ncbi.nlm.nih.gov/pubmed/?term=guo%20j%5bauthor%5d&cauthor=true&cauthor_uid=24238434 http://www.ncbi.nlm.nih.gov/pubmed/?term=simon%20jh%5bauthor%5d&cauthor=true&cauthor_uid=24238434 http://www.ncbi.nlm.nih.gov/pubmed/?term=sedghizadeh%20p%5bauthor%5d&cauthor=true&cauthor_uid=24238434 http://www.ncbi.nlm.nih.gov/pubmed/?term=soliman%20on%5bauthor%5d&cauthor=true&cauthor_uid=24238434 http://www.ncbi.nlm.nih.gov/pubmed/?term=soliman%20on%5bauthor%5d&cauthor=true&cauthor_uid=24238434 http://www.ncbi.nlm.nih.gov/pubmed/?term=chapman%20t%5bauthor%5d&cauthor=true&cauthor_uid=24238434 http://www.ncbi.nlm.nih.gov/pubmed/?term=enciso%20r%5bauthor%5d&cauthor=true&cauthor_uid=24238434 http://www.ncbi.nlm.nih.gov/pubmed/24238434 dropbox 5 hassanie f 25-30.pdf simplify your life dropbox 06 noor 28-32.pdf simplify your life omar f.doc j bagh college dentistry vol. 25(2), june 2013 oral manifestations oral diagnosis 89 oral manifestations, biochemical, and il-6 analysis of saliva in major depressive disorder patients under treatment omar f. fawzi, b.d.s. (1) fawaz d. al-aswad, b.d.s., m.sc., ph.d. (2) abstract background: major depressive disorder (mdd) is mental disorder characterized by an all-encompassing low mood accompanied by low self-esteem, and by loss of interest or pleasure in normally enjoyable activities. the aims of the study: were to determine the prevalence of oral manifestation among patients with major depressive disorder receiving antidepressant drugs, and detect alkaline phosphatase (alp), total salivary proteins (tsp), and interleukin-6 (il-6) in relation to mdd patients under treatment and to compare with healthy controls. materials and method: (50) mdd patients; between the ages of 20 years and 60 years.the depression patients are divided into (25) patients under treatment with fluoxetine (prozac), and (25) patients under treatment with imipramine (tofranil).the depression patients are diagnosed according to hamilton depression scale used in the department of psychiatry in al-yarmouk teaching hospital by a psychiatric specialist. results: the most frequent oral manifestations in the patients with mdd, in this study were burning mouth syndrome (72%), and dry mouth (70%), while metallic taste (48%) was fairly frequent, males more effected than females.burning mouth syndrome, and metallic taste were more frequent in patients with prozac treatment, while dry mouth was more frequent in patients with tofranil treatment. increased levels of il-6, tsp, and alp in mdd patients receiving treatment as compared to healthy control conclusion: frequent oral examination of patients with mdd is mandatory, and these patients should be a major concern in dental practice. keywords: major depressive disorder, oral manifestations, alp, tsp, il-6. (j bagh coll dentistry 2013; 25(2):89-93). introduction the term "depression" is ambiguous. it is often used to denote this syndrome but may refer to other mood disorders or to lower mood states lacking clinical significance(1,2). the diagnosis is based on the patient's selfreported experiences, behavior reported by relatives or friends, and a mental status examination. there is no laboratory test for major depression(1).saliva has tremendous potential source of biological molecules to some as indicators of many diseases, and also monitoring different types of medications. it may have the potential to replace serum in many analyses(2,3).during the last decade several studies were done to determine the prevalence of oral manifestation with emphasis on the different medication of treatment of mdd (4,5).therefore the present study was instigated since no extensive studies have been made in iraq on oral manifestation allocated with mdd, and in order to show that a routine dental examination for patients with antidepressant medications is necessary.finally the research is supported with biochemical studies (il-6, alp, tsp) to draw comparisons and to test their significant differences between samples. (1) m.sc. student, department of oral medicine college of dentistry, university of baghdad. (2) professor , department of oral medicine, college of dentistry, university of baghdad. the aims of the study are to determine the percentage of oral manifestation among patients with major depressive disorder receiving antidepressant medications, and to provide base line information for future studies and comparisons. correlate the prevalence of the oral manifestations according to age, gender, type and duration of medications.determine the level of the following markers among antidepressant and control groups in unstimulated saliva:il-6, alp, and tsp. materials and methods the study sample consists of (50) mdd patients receiving treatment for more than 1 month, 20 healthy; according to their personal statement, control group of both genders. the depression patients were divided into (25) twenty five patients under treatment with fluoxetine prozac, and (25) twenty five patients under treatment with imipramine tofranil. the depression patients were diagnosed according to hamilton depression scale (1960) used in the department of psychiatry in al-yarmouk teaching hospital by a psychiatric specialist; they were examined from the period (6-12-2011----173-2012) to detect the prevalence of oral manifestation, biochemical analysis, and salivary il-6 measurement. j bagh college dentistry vol. 25(2), june 2013 oral manifestations oral diagnosis 90 exclusion criteria patients with heavy smoking and alcoholism, pregnant women, diabetic patients, patients received radiotherapy, chemotherapy, and patients receiving combination of prozac and tofranil, and any other systemic disease. materials used for immunological and biochemical analysis 1.salivaryinterleukinelisa -6kit catalog number:abin455601. 2.total salivary proteins man. cat #:23225. 3.alkaline phosphatase elisa kit catalog number: csb-e09033h oral examination all the patients examined by a single examiner, under standardized conditions; the oral cavity examined in an artificial light by using a mouth mirror. the procedure of examination of oral soft tissue was done in sequence according to directions suggested by the w.h.o.(1987) oral manifestations a-xerostomiawas diagnosed according to the subjective complaint of all patients of dry mouth due to a lack of saliva(6). b-burning mouth syndromewas identified according to burning or tingling sensation on the lips, tongue, or entire mouth(7). c-metallica tastewas diagnosed according to the distortion of the sense of taste, the distortion in the sense of taste is the only symptom, and diagnosis is usually complicated since the sense of taste is tied together with other sensory systems(8). immunological and biochemical analysis salivary interleukin-6, and salivary alkaline phosphatase levels was determined using elisa technique. total salivary proteins level was determined using bca technique. statistical analysis data are analyzed through the use of spss (statistical process for social sciences) version 10.0 application statistical analysis system, excel (statistical package) and microsoft word. descriptive data analysis 1. tables (frequencies, percentages and cumulative percentages) 2. mean, trimmed mean, median. 3. standard deviation (std. d.), standard error (std. error), range, interquartile range . 4. (95%) confidence interval for population mean values. 5. two extreme values (min. and max.) respondents. 6. contingency coefficients for the causes correlation ship of the contingency tables. 7. odds ratio coefficient for represents the number of times that the target factor (increased /or decreased) by the other factor in the association table. 8. cohort group study for represents the risk estimate. 9. graphical presentation by using:barcharts, custer bar charts.pie charts.stem-leaf plot. inferential data analysis 1-binomial test procedure. 2-mann-whitney test (a nonparametric equivalent to the t test). 3-chi-square test. 4-contingency coefficients test. results prevalence of oral manifestation according to age, gender, type of medication, and duration treatment as shown in (table 1) the results has reported that with burning mouth syndrome manifestation a significant difference was obtained at p<0.05 with treatment only and with a non-significant at p>0.05 were recorded with the leftover, then followed with dry mouth manifestation a highly significant difference was obtained at p<0.01 with duration only and with a non-significant at p>0.05 were recorded with the leftover, then followed with metallic taste manifestation a significant difference was obtained at p<0.05 with duration only and with a non-significant at p>0.05 were recorded with the leftover. immunological analysis salivary il-6 higher mean value of il-6 in patients treated with tofranil than patients treated with prozac as shown in (figure 1). table 1: causes correlation ships of the distribution among some related variables (age, gender, treatment, and duration) and the studied oral manifestation some related variables x oral manifestation (*) conting ency coeffici ent approx. sig. c.s. burning mouth syndrome age groups 0.319 0.340 ns gender 0.075 0.594 ns treatment 0.336 0.012 s duration 0.411 0.071 ns dry mouth age groups 0.238 0.701 ns gender 0.122 0.384 ns treatment 0.213 0.123 ns duration 0.489 0.008 hs metallic taste age groups 0.371 0.157 ns gender 0.125 0.374 ns treatment 0.158 0.258 ns duration 0.439 0.036 s j bagh college dentistry vol. 25(2), june 2013 oral manifestations oral diagnosis 91 figure 1: bar chart for the mean values of il-6 (pg/ml) parameter distributed between the two different types of treatments of the study sample of depression status figure 2: sequence of il-6 pg/ml parameter readings a long duration periods of treatment with both drugs ( tofranil and prozac) concerning the duration of treatment, (figure 2) shows slight increase in il-6 level with increased duration of treatment with both medications tofranil&prozac, also with periods of high elevations and demotions. biochemical analysis alkaline phosphatase a higher mean value of alp in patients treated with tofranil that patients treated with prozac as shown in (figure 3) an increase in the concentration of alp according to the duration of treatment in both medications, (figure4) also revealed periods of high elevations and demotions in alp level at (24-54 months). figure 3: bar chart for the mean values of alp (ng/ml) parameter distributed between the two different types of treatments of the study sample of depression status figure 4: sequence of alp ng/ml parameter readings a long duration periods of treatment with both drugs ( tofranil and prozac) total salivary proteins figure (5) shows that a higher mean value of total proteins in patients treated with prozac than patients treated with tofranil.(figure 6) shows investigations concerning the duration of treatment with both medication tofranil&prozac, a slight increase in the concentration of tsp was evident, with periods of elevations and demotions. figure 5: bar chart for the mean values of total proteins (ng/ml) parameter distributed between the two different types of treatments of the study sample of depression status. figure 6: sequence of total proteins ng/ml parameter readings a long duration periods of treatment with both drugs ( tofranil and prozac) biochemical and immunological analysis compared to healthy groups table (2) represents the target of the critical base line of the study sample for abnormal(il-6 pg/ml), (alp ng/ml), and (total proteins ng/ml) j bagh college dentistry vol. 25(2), june 2013 oral manifestations oral diagnosis 92 parameters. high mean values of study parameters when compared to control. discussion patients that take psychotropic medications for long periods may experience behaviors that have a negative impact on oral health. these medications may cause lethargy, fatigue and lack of motor control and memory that may impair the individual’s ability to practice a good oral hygiene technique(9).the present study showed no significant relationship between total oral manifestation and age. this was also reported by jorm (10), and disagreed with snowdon (11) he stated that his findings have been inconsistent, but majority opinion holds that oral manifestations in mdd are common in old age.regarding the duration of the treatment the oral examination revealed oral complication at the time of the examination and does not give an indication about the past; to go in depth in this parameter, this require a retrospective study with a longitudinal design. this is definitely outside the scope of this study however the interpretation of the duration of treatment when studied should be treated with caution. in our findings bms, and dry mouth was evident with high statistical significant when compared to healthy group this was also mentioned by scully (12).it might argue that age of onset of depression may reflect the time when the patient fulfilled the diagnostic criteria of mdd. the mean age of disease onset in males was at young aged, while in females was in middle aged, hans-ulrich et al, (13) reported the same results. this may be partially explained by that the environmental factor, life styles, and diet may influence the development of these complications and decrease susceptibility with advancing age.this study showed that the level of salivary il-6 was higher in mdd patients receiving treatment with both medications tofranil and prozac than healthy controls however, this was not statistically significant, kuberaet al.(14) found different results, they speculated that the therapeutic activity of these antidepressants is at least partly connected with their effect on the cytokine network and il-6 production.salivary alp activity level was elevated in relation to type of medication, and duration of treatment than control group in all mdd patients receiving treatment with both medications with no statistical significance, this was close to that reported by diemet al. (15), they found that antidepressant medications can profoundly affect bone metabolism. in some scenarios (eg, osteoporosis), these effects are intended, potentially adverse side effects of medications on bone may occur.this study showed higher significant tsp value than control patients in all mdd patients receiving treatment with both medications, these results differed from those of van hunsel et al (16) they found that tsp was lower in mdd patients. this may be explained by the fact that major depression is accompanied by an acute phase response (apr), characterized by elevated levels of positive acute phase proteins (apps) and decreased levels of negative apps.this study showed also higher mean value of tsp in mdd patients treated with prozac than mdd patients treated with tofranil with no statistical significance, this was also mentioned by hunter and wilson (17) they explained the varyingly increased tsp that have been reported more with tofranil to the suppressive effects of tricyclic antidepressants and ssri are profound, and extend beyond suppressing resting parameters to reducing stimulated salivary flow. according to the results presented in the present study tsp was found to be higher in study group as compared to healthy, the difference was statistically significant, actually when the duration of treatment were considered in mdd a significant correlation was found. references 1. sidana s, kishore j, ghosh v, gulati d, jiloha r, anand t. prevalence of depression in students of a medical college in new delhi: a cross-sectional study. austral med j 2012; 5(5): 247-250. 2. greabu m, battino m, mohora m, totan a, didilescu a, spinu t, totan c, miricescu d, radulescu r. saliva--a diagnostic window to the body, both in health and in disease. j med life 2009; 2(2): 124-132. 3. kinney js, morelli t, braun t, ramseier ca, herr ae, sugai jv, shelburne ce, rayburn la, singh ak, and giannobile wv. saliva/pathogen biomarker signatures and periodontal disease progression j dent res 2011; 90: 752-758. 4. reddy rs, vijayalaxmi n, ramesh t, raju rr, reddy rl, singh tr. mood and mouth. j dr ntr univ health sci 2012; 1: 106-110. 5. joseph ti, vargheese g, george d, sathyan p. drug induced oral erythema multiforme: a rare and less recognized variant of erythema multiforme. j oral maxillofac pathol 2012; 16: 145-148. 6. jeganathan s, carey h, purnomo j. impact of xerostomia on oral health and quality of life among adults infected with hiv-1. spec care dentist 2012; 32(4): 130-135. 7. klasser gd, epstein jb, villines d. management of burning mouth syndrome. j mich dent assoc 2012; 94(6): 43-46. 8. sakagami m. diagnosis and treatment of taste disorders. nihon jibiinkokagakkaikaiho 2012; 115(1): 8-13. 9. mcclain d, bader j, daniel s, sams d. gingival effects of prescription medications among adult dental patients. special care in dentistry 1991; 11(1): 15-18. j bagh college dentistry vol. 25(2), june 2013 oral manifestations oral diagnosis 93 10. jorm af. does old age reduce the risk of anxiety and depression? a review of epidemiological studies across the adult life span. psychological medicine 2000; 30(1): 11-22. 11. snowdon j. is depression more prevalent in old age? aust nzj psychiatry 2001; 35(6): 782-787. 12. scully c. drug effects on salivary glands; dry mouth. oral dis 2003; 9: 165-176. 13. hans-ulrich wittchen, stefan uhmann, the timing of depression: an epidemiological perspective. medicographia 2010; 32: 115-125. 14. kubera m, kenis g, bosmans e, kajta m, basta-kaim a, scharpe s, budziszewska b, maes m. stimulatory effect of antidepressants on the production of il-6. int immunopharmacol 2004; 4(2): 185-192. 15. diem sj, blackwell tl, stone kl, yaffe k, haney em, bliziotes mm, ensrud ke.use of antidepressants and rates of hip bone loss in older women: the study of osteoporotic fractures. arch intern med 2007; 167(12):1240-1245. 16. van hunsel f, wauters a, vandoolaeghe e, neels h, demedts p, maes m. lower total serum protein, albumin, and betaand gamma-globulin in major and treatment-resistant depression: effects of antidepressant treatments. psychiatry res 1996; 65(3): 159-169. table 2: summary statistics and the standardized limitations for the studied parameters by applying the suggested technique of depression status statistic alp ng/ml il-6 pg/ml total proteins ng/ml study control study control study control mean 70.5 13.8 40.4 12.8 2246.1 1696.6 95% confidence interval for mean lower bound 9.5 12.2 3.5 8.9 1865.8 1425.4 upper bound 131.5 15.4 77.2 16.8 2626.4 1967.8 5% trimmed mean 29.9 13.6 16.1 12.8 2162.3 1692.3 median 16.8 14.0 11.4 12.9 2083.0 1689.5 std. error 30.3 0.8 18.3 1.9 189.2 129.6 std. deviation 214.6 3.1 129.6 7.7 1338.2 579.5 minimum 9.6 9.1 0.0 1.2 438.0 804.5 maximum standardized limits : (cutoff point) 1408.6 20.8 842.0 25.8 6000.0 2666.0 range 1399.0 11.7 842.0 24.6 5562.0 1861.5 interquartile range 9.2 4.2 15.1 12.4 1989.3 983.3 c.s. p-value levene's test p=0.063 p=0.079 p=0.003 student's test p=0.282 p=0.375 p=0.019 statistical decision ns ns s alan.doc j bagh college dentistry vol. 26(4), december 2014 ions release from pedodontics, orthodontics and preventive dentistry152 ions release from fixed orthodontic appliance in two different mouthwashes reem atta rafeeq, b.d.s., m.sc. (1) alan issa saleem, b.d.s., m.sc. (1) layth m. k. nissan, b.d.s., m.sc. (1) abstract background: metal ions can be released from metallic orthodontic appliances due to corrosion in the oral cavity; prophylactic mouthwashes may have an effect on ion release from orthodontic wires. materials and methods: thirty six orthodontic sets of half maxillary fixed appliance with 2 types of arch wires ss and niti(morelli) were constructed and immersed in 2 types of mouthwashes; claradone (non-fluoridated) and silver care (fluoridated) for 28 days at 37°c, then the released ni and cr ionswere measured using atomic absorption spectrophotometer and compared statistically. results: ni ion release was higher from niti wire group than ss wire group for both mouthwashes and also was higher for silver care group than for claradone group. while for cr ion was higher for silver care group than for claradone group, with significant differences for all the groups. conclusion: claradone non-fluoridated mouthwash cause less release of ni and cr ions release from the orthodontic appliance samples than silver care fluoridated mouthwash. keywords: corrosion, mouthwash, ni, cr. (j bagh coll dentistry 2014; 26(4):152-155). introduction many studies have demonstrated that metal ions can be released from metallic orthodontic appliances as a result of corrosion due to exposure to the oral environment, and this can influence the mechanical properties of the appliance and may also affect the body (1-3). metallic orthodontic appliance sare commonly made from different alloys such as stainless steel (iron-chromiumnickel), titanium (ti) and elgiloy (cobaltchromium) which are frequently used in the manufacture of brackets, while wires could be made from stainless steel (ss), cobalt-chromium, titanium-molybdenum (tma) and nickel-titanium (ni-ti) alloy (4,5). during orthodontic treatment, the regular use of fluoride containing products such as tooth pastes and mouth washes is recommended to reduce the risk of dental caries and development of decalcification spots around the brackets (4,6). however, some studies have shown that in an acidic environment and in the presence of fluoride ions the corrosion resistance of some materials (especially titanium) can deteriorate due to the breach of the protective oxide layer on the surface of the titanium alloy (79). although fluoride ions in the prophylactic agents have been reported to cause corrosion, but little information is available regarding the effect of different mouthwashes on ion release from orthodontic wires (10,11). the purpose of this study was to measure the levels of metal ions released from orthodontic appliance after immersion in 2 different mouthwashes. the result should help practitioners (1)lecturer. department of orthodontics, college of dentistry, university of baghdad to decide which mouthwash to prescribe for their patients. materials and methods the sample includes 36 structurally identical orthodontic sets, each set simulate half average maxillary fixed orthodontic appliance (from central incisor to first molar) that consisted of five ss bondable brackets (slot 0.022'') and one ss band and a piece of arch wire 3 cm long (0.016x0.022'') of either ss or ni-ti which was tied to each bracket using ss ligature wire (0.001'') and all were made by morelli ortodontia, sorocaba-sp, brazil (figure 1). each part of the appliance was cleaned ultrasonically with ethanol and acetone, rinsed with distilled water and then dried in air,and afterthe components of each set were held securely by the arch wire and ligated by stainless steel ligature wire, were immersed in acetone for 8 seconds and dried in air (12, 13).only the closely similar weights were used for bands, brackets and arch wires by using the analytic balance device. the 36 constructed appliancesets were divided into 4 groups (containing 9 sets in each group) according to the type of arch wire used as follows: • group a: brackets and a band ligated on ss archwire. • group b: brackets and a band ligated on niti archwire. • group c: brackets and a band ligated on ss archwire. • group d: brackets and a band ligated on niti archwire. then each appliance set in group a and b was fully immersed in 30 ml of non-fluoridated j bagh college dentistry vol. 26(4), december 2014 ions release from pedodontics, orthodontics and preventive dentistry153 mouthwash (claradone mouthwash, medpharma, united arab emirates) containing povidone iodine usp 1.0 % w/v with ph of 2.8, and each appliance set in group c and d was fully immersed in 30 ml of fluoridated mouthwash(silver care mouth wash,italy) containing two fluoride salts; sodium fluoride 0.10% and monofluorophosphate 0.03% with total fluoride contentof 490 ppm with ph of 5.8 (figure 2) in closely packed glass test tube (figure 3)and kept in an incubator at 37°c for 28 days. the samples were analyzed with an atomic absorption spectrophotometer (flameless atomic absorption spectrophotometer-shimadzu/aa-670, japan) (figure 4) with sensitivity 1/10-4 in the labs of the ministry of science and technology. the concentrations of nickel & chromium ions were calculated as micrograms per ml. the ph of both mouthwashes was measured by hanna (hi8014 -romania) digital ph meter (figure 5). the statistical analysis was done using spss program version 15, including descriptive statistics, t-test. p value of (p ≤ 0.05) was regarded as statistically significant. results the results of atomic absorption analysis of the nickel (ni) and chromium (cr) ions concentrations in the two mouthwashes showed that the release of ni ion was higher from niti wire group than those of the ss wire in both mouthwashes used and also ni ion release was higher in fluoridated mouthwash (fm) group than figure 1: constructed orthodontic set figure 2: mouth washes used in the study. figure 3: samples in test tubes. figure 4: flameless atomic absorption spectrophotometer. figure 5: hanna digital ph meter. j bagh college dentistry vol. 26(4), december 2014 ions release from pedodontics, orthodontics and preventive dentistry154 those in non-fluoridated mouthwash (nfm) group for both arch wire types (table 1) with statistically significant differences between all the groups (table 2). the release of cr ion was also higher in fm group than that of nfm group (table 1) with statistically significant difference (table 2). table 1: descriptive statistics of nickel and chromium ion concentrations in different groups ions groups min. max. mean s.d. ni a .20 .41 .301 .079 b .31 .49 .395 .056 c .2900 .5000 .390 .064 d .3400 .5700 .4689 .077 cr a .0220 .0810 .051 .018 c .0480 .0900 .069 .014 table 2: difference in the ni and cr ion release among different groups by t-test ions groups concentration differences (n=9, d.f.=8) t-test p-value sig. ni a & b 2.082 .071 ns c & d 2.801 .023 s a & c 4.996 .001 hs a & d 5.023 .001 hs cr a & c -2.982 .018 s discussion stainless steel orthodontic appliances can release metal ions into the saliva. fluoridated and non-fluoridated mouthwashes are often recommended to orthodontic patients to reduce the risk of white-spot lesions around the appliances. however little information is available regarding the effect of different mouthwashes on ion release of orthodontic archwires. in this study the appliance consisted of brackets, bands and wires, and it is likely that the brackets and bands contributed to the quantities of released ions, however, because the brackets and bands consisted of the same material and the same weight in all samples, their contribution was constant and did not influence relative comparisons of ions released from wires. regarding the use of mouth wash in this study, the wires were immersed in mouth washes and incubated at 37°c for 28 days.several studies have demonstrated that the levels of metal release from fixed orthodontic appliances peak at day 7, and that all release is completed within 4 weeks (1,3,14). in this study a comparison of ni ion concentration from the various solutions showed that the maximum release was in fluoridated mouthwash than in nonfluoridated mouthwash and from the niti wire higher than ss wire, in spite of that nfm was more acidic (ph = 2.8) than fm (ph = 5.8), and this could be attributed to the fact that povidone – iodine could reduce the corrosion of titanium alloy as the iodine does not have the ability to penetrate the oxide layer on the titanium surface (15) while in the fm the presence of fluoride ion in acid aqueous environment can lead to formation of hydrofluoric acid (which can rapidly attack titanium even in dilute concentration in ph below 7) causingbreakdown of the protective oxide layer on the surface of titanium alloy leading to decrease of corrosion resistance and this agrees with many authors (4-6,16-18). in addition iodine is an antiseptic agent acting on bacteria, viruses, tb bacilli and fungi with no cytotoxic or adverse reactions on the body (19). analysis of released cr ions revealed adifference only in the fluoridated mouth wash group (p<.05), this is also agree with kao et al. (5). many authors (14,16-18) have alerted practitioners to the possibility of hypersensitivity reactions to released cr and ni ions because they can result in symptoms of toxicity and allergic reactions. the present study shows the risk offluoride containing mouthwashesin causingmore corrosion and higher levels of ion release from both ss and niti components of orthodontic appliance which may lead to impaired mechanical performance and unsatisfactory results on one hand and on the other hand ni and cr ions released in the organism can cause allergic reactions and this agree with many studies (4-6,16,20-24). in conclusion, claradone nfm caused less metallic ion release from orthodontic appliances than from silver care fm. references 1. park hy, shearer tr. in vitro release of nickel and chromium from simulated orthodontic appliances. am j orthod 1983; 84: 156-9. 2. grimsdottir mr, gjerdet nr, hensten-pettersen a. composition and in vitro corrosion of orthodontic appliances. am j orthod dentofacial orthop 1992; 101: 525-32. 3. barrett rd, bishara se, quinn jk. biodegradation of orthodontic appliances: part 1. biodegradation of nickel and chromium in vitro. am j orthod dentofacial orthop 1993; 103: 8-1 4. danaei sm, safavi a, roeinpeikar smm, iranpour s, omidekhoda m. ion release from orthodontic brackets in 3 mouth washes:an in–vitro study. am j orthod dentofacial orthop 2011; 139: 730-4. (ivsl). 5. kao c-t, ding s-j, he h, chou my, huang t-h. cytotoxicity of orthodontic wire corroded in fluoride solution in vitro. angle orthod 2007; 77(2): 349-54. (ivsl). 6. schiff n, dalard f, lissac m, morgon l, grosgogeat b. corrosion resistance of three orthodontic brackets: j bagh college dentistry vol. 26(4), december 2014 ions release from pedodontics, orthodontics and preventive dentistry155 a comparative study of three fluoride mouthwashes. eur j orthod 2005; 27: 541-9. 7. reclaru l, meyer jm. effects of fluorides on titanium and other dental alloys in dentistry. biomaterials 1998; 19: 85–92. 8. nakagawa m, matsuya s, udoh k. corrosion behavior of pure titanium and titanium alloys in fluoride-containing solutions. dent mater j 2001; 20: 305–14. 9. schiff n, grosgogeat b, lissac m, dalard f. influence of fluoridated mouth washes on corrosion resistance of orthodontic wires. biomaterials 2004; 25: 4535-42. 10. marinho vc, higgins jp, logan s, sheiham a. flouride mouth rinses for preventing dental caries in children and adolescents. cochrane database syst rev 2003; 10(3): cd002284. 11. demelo jf, gjerdet nr, erichsen es. metal release from cobalt-chromium partial dentures in the mouth. acta odont scand 1983; 41: 71-4. 12. al-jubory hm, ali fa. corrosive behavior and biological effect of fixed orthodontic appliance in artificial saliva: in vitro study. j bagh coll dentistry 2001; 10: 57-64. 13. kuhta m, palvin d, slaj m, varga s, varga ml, slaj m. type of archwire and level of acidity: effects on the release of metal ions from orthodontic appliances. angle orthod 2009; 79(1): 102-10. (ivsl). 14. mockers o, deroze d, camps j. cytotoxicity of orthodontic bands, brackets and archwires in vitro. dent mater 2002; 18: 311-7. 15. bhola r, bhola sm, mishra b, olson dl. effect of povidone-iodine addition on the corrosion behavior of cp-ti in normal saline. j material sci. materials in medicine 2010; 21(5): 1413-20. 16. schiff n, boinet m, morgon l,lissac m, dalard f, , grosgogeat b. galvanic corrosion between orthodontic wires and brackets in fluoride mouthwashes. eur j orthod 2006; 28: 298-304. 17. schiff n, grosgogeat b, lissac m, dalard f. influence of fluoride content and ph on the corrosion resistance of titanium and its alloys. biomaterials 2002; 23: 1995–2002. 18. kaneko k, yokoyama k, moriyama k, asaoka k, sakai j, nagumo m. delayed fracture of beta titanium wire in fluoride aqueous solutions. biomaterials 2003; 24: 2113–2120. 19. tsuchiya h, shirai t, nishida h, murakami h, kabata t, yamamoto n, watanabe k, nakase j. innovative antimicrobial coating of titanium implants with iodine. j orthop sci 2012; 17: 595–604. 20. gjerdet nr, erichsen es, remlo he, evjen g. nickel and iron in saliva of patients with fixed orthodontic appliances. acta odontol scand 1991; 49:73-78. 21. moffa jp. biological effects of nickel-containing dental alloys. j am dent assoc 1982; 104: 501-5. 22. hwang cj, shin js, cha jy. metal release from simulated fixed orthodontic appliances. am j orthod dentofacial orthop 2001; 120: 383-91. 23. hussein af, al-mulla a. the effect of food simulants on corrosion of simulated fixed orthodontic appliance. j bagh coll dentistry 2010; 22(1): 68-75. 24. saleem ae, aldaggistany ms, ahmed as. nickel and chromium ions release from fixed orthodontic appliances in iraqi patients. mdj 2011; 8(2): 139-43. 15. suhaib f.doc j bagh college dentistry vol. 27(4), december 2015 p16 protein and oral diagnosis 96 p16 protein and human papillomavirus (hpv16, 18) expressions in oral lichen planus and squamous cell carcinoma suhaib raghib muhsin, b.d.s. (1) ahlam hameed majeed, b.d.s., m.sc. (2) abstract background: oral carcinogenesis is a molecular and histological multistage process featuring genetic and phenotypic markers for each stage, which involves enhanced function of several oncogenes and/or the deactivation of tumor suppressor genes, resulting in the loss of cell cycle checkpoints. the progression towards malignancy includes sequential histopathological alterations ranging from hyperplasia through dysplasia to carcinoma in situ and invasive carcinoma. the p16 gene produces p16 protein, which in turn inhibits phosphorylation of retinoblastoma, p16 play a significant role in early carcinogenesis. human papillomavirus is a well established heterogeneous virus and plays an important role in oral cancers. the aims of the study were to evaluate, compare and correlate the immunohistochemical expression of p16 protein and hpv16/18 with each other in oral lichen planus and oral squamous cell carcinoma, and with various clinicopathological findings. materials and methods: forty formalin-fixed, paraffin embedded tissue blocks (24 cases of oral lichen planus, and 16 cases of oral squamous cell carcinoma) were included in this study, an immunohistochemical staining was performed using anti p16 monoclonal antibody, and anti hpv16/18 monoclonal antibodies. results: positive ihc expression of p16 was found in 11 cases (68.75%) of oscc, and in 19 cases (79.166%) of olp. positive ihc expression of hpv16 was found in 2 cases (12.5%) of oscc, and in 1 case (4.16%) of olp. ihc expression of hpv18 showed negative expression in all cases of oscc, and found only in 1 case (4.16%) of olp. conclusions: this study signifies the statistically non significant correlation between p16 and hpv 16/18 in olp and oscc. keywords: olp, oscc, p16, hpv. (j bagh coll dentistry 2015; 27(4):96-100). introduction oncogenesis (carcinogenesis) is the progression from a normal healthy cell to a premalignant or a potentially malignant cell characterised by an ability to proliferate autonomously. oncogenesis involves a series of genetic steps and also epigenetic–outside the gene-changes. these changes include the aberrant expression and function of molecules regulating cell signalling, growth, survival, motility, angiogenesis (blood vessel proliferation), and cell cycle control (1). cancer of the oral cavity is the sixth most common cancer worldwide and account for nearly 3% of all malignancies (2). p16 is a tumor suppressor protein, that in humans is encoded by the cdkn2a gene (3,4). it regulates the rb tumor suppressor pathway by keeping rb in a hypophosphorylated state, which further promotes the binding of e2f to achieve g1 cellcycle arrest. the disruption of p16 expression has been reported in various human cancers (5-7). human papillomavirus (hpv) is a wellestablished heterogeneous virus and is important in human carcinogenesis. it not only causes a vast majority of cervical cancers but also plays an important role in anogenital and oral cancers (8). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. it has been established that hpvs are exclusively epitheliotropic, meaning that their infection is specifically localised in epithelial cells of the host. in order to complete their life cycle, they rely on epithelial differentiation(9). the present study aimed to evaluate, compare and correlate the immunohistochemical expression of p16 protein and hpv16/18 in oral premalignant lesion and oral squamous cell carcinoma, and with each other in various clinicopathological findings. materials and methods the study samples included 40 formalin-fixed, paraffin embedded tissue blocks (24 olp, and 16 oscc) dated from (1975 till 2013), were obtained from the archives of the department of oral & maxillofacial pathology/ college of dentistry/ university of baghdad; al-shaheed ghazi hospital/ medical city during the period from (1975-2013). sections of 4μm thickness were mounted on normal glass slides, stained with h&e for histopathologically re-evaluation. four other 4μm thick sections for each case were cut and mounted on positively charged slides (fisher scientific and escho super frost plus, usa) for immunohistochemical staining with monoclonal antibody p16 and hpv16/18 using abcam expose mouse and rabbit hrp/dab j bagh college dentistry vol. 27(4), december 2015 p16 protein and oral diagnosis 97 immunohistochemical detection kit (catalog no. ab80436, cambridge, uk). results positive p16 immunostaining was detected as brown nuclear or (nuclear and cytoplasmic) expression. ihc staining of p16 in oscc reveals that 5 cases (31.25%) showed negative expression, 5 cases (31.25%) showed weak positive expression, 1 case (6.25%) showed moderate positive expression, and 5 cases (31.25%) showed high positive expression. while in olp ihc staining of p16 reveals that 19 cases (79.166%) showed negative expression (cases showing more than 5% of positive cells), and 5 cases (20.833%) showed negative expression (cases showing less than 5% of positive cells), figures (1,2). positive hpv16/18 immunostaining was detected as brown nuclear expression. positive ihc expression of hpv16 was found in 2 cases only (12.5%) of oscc, and 14 cases (87.5%) showed negative expression. hpv16 positivity was found in 1 case only (4.16%) of olp, and 23 cases (95.83%) showed negative expression. ihc expression of hpv18 showed negative expression in all cases of oscc. positive ihc expression of hpv18 was found in 1 case only (4.16%) of olp, and 23 cases (95.83%) showed negative expression. figure (3,4,5). p16 expression were observed in almost cases of oscc and olp and according to chi square test, statistically non significant correlation with clinicopathological findings (age, sex, tumor site, tumor grade) except tumor site of oscc in p16 was statistically significant, while hpv16/18 expression was detectable in few cases of oscc and olp and correlation between the expression of markers (p16, hpv16, hpv18) were non significant statistically in oscc and olp (p=0.757, 0.327, 0.874) respectively, as clarified in tables (1,2,3). figure (1): positive expression of p16 in well differentiated oscc (40x). figure (2): positive expression of p16 in olp (40x). figure (3): positive expression of hpv16 in oscc (40x). figure (4): positive expression of hpv16 in olp (40x). j bagh college dentistry vol. 27(4), december 2015 p16 protein and oral diagnosis 98 p16 +ve -ve n x2 sig olp 19 5 24 0.096 0.757 oscc 12 4 16 total 31 9 40 discussion the present study is not a large epidemiological one that expressed the incidence and prevalence of different clinicopathological features of olp and oscc, however, there was a close correlation between the present data and other published data concerning the incidence of olp and oscc in iraq in the past studies records and studies in other parts in the world (10,11). assessment of p16 immunohistochemistry: p16 positivity was found in (68.75%) of oscc cases. concerning the correlation between clinicopathological findings of oscc cases and p16, the present study showed statistically significant correlation between p16 expression and the tumor site, while there was non significant difference between p16 with age, sex, site, and grades of oscc. the discrepancies in the result of p16 expression in this result and with other studies (12,13) could be attributed to limited sample size of the current study. concerning olp cases the results of this study showed that positive expression of p16 was observed in 19 cases (79.166%) and negative expression in 5 cases (20.833%). montebugnoli et al and poomsawat et al detected p16 in 64% of olp samples and reported that p16 expression in 65.2% of olp cases respectively (14,15). different cancer-causing agents may lead to p16ink4a gene inactivation as well as altered p53 and prb tumor suppressive pathways (16,17). the loss of p16 expression as a result of promoter hypermethylation is an early event in oral carcinoma and a useful biomarker for predicting local recurrence in carcinoma of the tongue (18). however, the role of p16 hypermethylation as a predictive risk factor for oscc or disease recurrence remains unclear and contradictory (19). assessment of hpv immunohistochemistry: in oscc, the present study showed negative hpv16 immunoreactivity in 14 cases (87.5%) and only 2 cases (12.5%) showed positive expression whereas in hpv18, all cases showed negative expression. this finding was in agreement with studies in other part of the world (20-22). in current study, most of oscc cases that showed negative expression found in cytoplasm. concerning the correlation between clinicopathological findings of oscc cases and hpv16 and 18, the present study showed non significant statistical correlation between hpv16, 18 expression with age, sex, site and grade were found (23-28). regarding olp, the result of this study showed positive expression of hpv16 only in 1 case and other 23 cases (95.83%) showed negative expression and same result was found in hpv18. few studies employed immunohistochemical detection of hpv 16 in oral lichen planus, in a turkish study by yildirim et al 21% of the cases were positive by immunohistochemistry (29). concerning correlation between p16 and hpv16/18 in oral squmous cell carcinoma and hpv16 +ve -ve n x2 sig olp 1 23 24 0.096 0.327 oscc 2 14 16 total 3 37 40 hpv16 +ve -ve n x2 sig olp 1 23 24 0.684 0.871 oscc 0 16 16 total 1 39 40 figure (5): positive expression of hpv18 in olp (40x). table (1): correlation between oscc and olp of p16 expression table (2): correlation between oscc and olp of hpv16 table (3): correlation between oscc and olp of hpv18 j bagh college dentistry vol. 27(4), december 2015 p16 protein and oral diagnosis 99 oral lichen planus, the present study showed statistically non significant correlation between p16 and hpv16,18 in oscc and olp. nemes et, al., showed that over-expression of p16ink4a proteins in oscc did not correlate with hr-hpv types (30). in addition, very high p16 expression observed not only in hpv positive groups but also in other groups in the absence of hpvs. therefore, it revealed unconvincing support for previous claims on the hpv-p16 relationship (31-34). concerning olp, non significant correlation was observed in p16 and hpv16 and 18. montebugnoli et al found p16ink4 expression was detected in 26 specimens, while hpv was found in four lesions: three low-risk hpv, and one high-risk hpv. all hpv-positive lesions also showed p16ink4a overexpression, whereas 22 cases of overexpressed p16ink4a were hpv negative (35). references 1. surveillance epidemiology and end results (seer). seer cancer statistics review 1975-2004. national cancer institute. 2. shah jp, gil z. current concepts in management of oral cancer-surgery. oral oncol 2009; 45(4): 394401. 3. stone s, jiang p, dayananth p, tavtigian sv, katcher h, parry d, peters g, kamb a, complex structure and regulation of the p16 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694-702. j bagh college dentistry vol. 30(2), june 2018 histological and oral diagnosis 10 histological and histomorphometric studies of the effects of hyaluronic acid on osseointegration of titanium implant in rabbits mohammad hasan mohammad, b.d.s., h.d.d (1) nada m. h. al-ghaban, b.d.s., m.sc., ph.d. (2) abstract background: one of the unique prosthesis for tooth or teeth replacement is the dental implant. our attempt is using a biomaterial system that is easily obtained and applicable and has the ability to provoke osteoinductive growth factor to enhance bone formation at the site of application. one of these natural polymers is hyaluronic acid. material and methods: sixty machined surface implants from commercially pure titanium rod inserted in thirty newzealand rabbits. two implants placed in both tibia of each rabbit. the animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). for all of animals the right tibia’s implant was control (uncoated) and the left one was experimental (coated with 0.1ml hyaluronic acid gel). all sections have been stained with haematoxylin and eosin then they were histologically examined and assessed for histomorphometric analysis for counting of bone cells (osteoblast, osteocyte and osteoclast), cortical bone thickness, trabecular width, thread width and marrow space star volume (v*). results: histological findings for hyaluronic acidcoated titanium implant revealed an earlier bone formation, mineralization and maturation than that in control groups. histomorphometric analysis for all bone parameters that examined in this study, showed highly significant difference between control and experimental groups in all healing intervals. conclusion: commercially pure titanium endosseous implants coated with hyaluronic acid may be osteocoductive thus accelerating healing process and enhancing osseointegration. key words: bone, implant, hyaluronic acid, osseointegration. (j bagh coll dentistry 2018; 30(2):10-16) introduction dental implant or fixture is a surgical component that interfaces with the bone of the jaw to support a dental prosthesis (1). the basis for modern implants is a biologic process called osseointegration where materials, such as titanium, form an intimate bond to bone (2). osseointegrated implant is a type of implant defined as "an endosteal implant containing pores into which osteoblasts and supporting connective tissue can migrate. applied to oral implantology, this refers to bone grown right up to the implant surface without interposed soft tissue layer (1) (3). various techniques of surface treatments have been introduced and applied to enhance surface properties of titanium implants, as a result supported osseointegration through encouraged bone formation and better implant stability (4). hyaluronan (hyaluronic acid) is considerd to be one of the fundamental constituent of connective tissue and bone marrow extracellular matrix. it mediates to chemotaxis, proliferation and successive differentiation of mesenchymal cells so it plays an essential function in regeneration and repaire of tissue (5).due to its osteogenic induction ability, biocompatibility and non-immunogenic nature and it believed to have angiogenic properties (6) ha coating process increases the (1) master student . (2) assistant professor, department oral diagnosis, college of dentistry, university of baghdad. hydrophilic nature of the implant surface such that the growth factors and proteins necessary for osseointegration are more readily attracted to the implant surface and increase the rate at which the bone heals (7). materials and methods sixty machined surface implants from commercially pure titanium rod inserted in 30 adult male new zealand white rabbits aged from 10 12 months and their weights were between 1.5 2 kgs. two implants placed in both tibia of each rabbit, one in right tibia as control and another one in the left tibia as an experimental. the animals scarified at 1, 2 and 4 weeks after implantation (10 rabbits for each interval). the implants categorized as control group (30 uncoated implants), 10 implants for each healing intervals and experimental group (30 hyaluronic acid coated implants), 10 implants for each healing intervals. the sterilization implants were placed in the hole of 5 mm in prepared in both rabbit’s tibiaes. the insertion of the uncoated one was directly done in the right tibia, while the insertion of the coated implants was performed in the left tibia after the application 0.1ml hyaluronic acid gel inside the threaded part of implants. after the rabbits were sacrificed at the end of recommended periods. the right and left tibias were dissected and the soft tissue was removed to https://en.wikipedia.org/wiki/dental_prosthesis https://en.wikipedia.org/wiki/osseointegration https://en.wikipedia.org/wiki/titanium https://en.wikipedia.org/wiki/implant_(medicine) https://en.wikipedia.org/wiki/bone https://en.wikipedia.org/wiki/dental_implant j bagh college dentistry vol. 30(2), june 2018 histological and oral diagnosis 11 expose the entire bone to be cut at 5 mm away of both implants sides to make implant contained bone blocks. the specimens were fixed in 10% formalin for 48h, decalcified with solution of formic acid, then bone tissue dehydrated with alcohol and embedded in paraffin. sections of 5μm were prepared in the usual fashion, and stained with hematoxylin and eosin. histological examination was performed using light microscope. histomorphometric assessment of bone cells (osteoblast, osteocyte and osteoclast), cortical bone thickness, trabecular width, thread width and marrow space star volume (v*).was done histological findings: one week duration a-control group the histological finding showed deposition of fibrous connective tissue with osteoid tissue in some area (figure 1). the thread area filled with osteoblasts, inflammatory cells, fibroblasts and progenitor cells (figure 2). figure 1: histological view of 1 week duration control group shows thread area filled with fibrous c.t. and osteiod tissue. h&e x10. figure 2: magnifying view shows progenitor cells (p), inflammatory cells(if), fibroblast (f), osteoblast(ob) and osteoid tissue(ot),h&e. x20. b-experimental group: the histological findings revealed woven bone in the thread area which was followed the implant shape (figure 3). in higher magnification the thread area filled with thin bone trabecluae with osteoblasts arranged in a single raw at the edges of these trabeculae, osteocytes were occupying their large lacunae (figure 4 and 5). figure 3: view of one week experimental group reveals woven bone in the thread area which was followed the screw shape and hyalinization of blood vessels h&e x4 figure 4: magnifying view shows thread with osteocytes (oc), adipose cells(ac), hyalinization of blood vessels and inflammatory cells (arrows) .h&e x20 figure 5: view of one week experimental group shows bone trabecullae filled with osteocytes (arrows) and lined by osteoblasts, osteoclasts (ocl).h&e x40. at 2 weeks duration a-control group: the histological view showed woven bone with few thin bone trabeculae filled with preosteocytes and osteocytes (figure 6, 7). bexperimental group: the histological view of 2weeks experimental group shows new bone trabeculae which j bagh college dentistry vol. 30(2), june 2018 histological and oral diagnosis 12 demarcated from basal bone by reversal line. these bone trabeculae filled with osteocytes and surrounded by osteoblast and osteoclasts (figure 8, 9). figure 6: histological view of 2week control group shows woven bone and thin bone trabecullae filled thread area .h&e x10 figure 7: magnifying view shows new bone trabecullae filled with large size osteocyte(oc) and preosteocytes(poc).h&e x10. figure 8: view of 2weeks experimental group shows woven bone(wb), new bone trabecullae (bt) filled thread area with osteoblasts(ob) and osteocytes(oc). h&e x20. figure 9: magnifying view shows reversal line (arrows) which separate between basal and new bone with osteoblasts(ob) and osteoclasts (ocl) . h&e x100 at 4weeks duration a-control group: the histological view shows formation of dense bone trabecullae filled with large size osteocytes and surrounded by active osteoblasts (figure 10). also presence of osteoclasts and reversal line in higher magnification this indicate continuous bone remodeling (figure 11). b-experimental group the histological view reveals well established mature bone rimmed by osteoblast and filled with osteocytes occupied their small lacunae in thread area (figure 12). in higher magnification the mature bone characterized by presence of haversion lamellae (figure 13). figure 10: view of 4 weeks control group shows osteoblasts (arrows), osteoclasts(ocl), and osteocytes(oc) in thread area. h&e x20 figure 11: magnifying view of 4 weeks control group shows osteocytes (oc) and reversal line (rl). h&e x100 j bagh college dentistry vol. 30(2), june 2018 histological and oral diagnosis 13 figure 12: histological view of 4 weeks experimental group shows mature bone rimmed by osteoblasts (arrows) and osteocytes(oc) in thread area. h&e x20. figure 13: magnifying view of 4 weeks experimental group shows haversian lamellae with osteocytes (oc) that arranged in a circle around haversian canal(hc). h&e x40. histomorphoetric analysis of studied groups for bone architecture parameters: the descriptive statistics of bone architecture parameters for control and experimental groups in all healing intervals are shown in (table 1). for both control and experimental groups, the mean values of cortical bone thickness, trabecular width and thread width are increase with proceeded time. the mean values for ha-coated group are higher than those in control group in all recovery periods. with advancing healing time marrow space star volume mean values are decreased in both groups, with noticeable reduction in ha coated group in comparison to control ones. the osteoblasts and osteocytes number mean values for both experimental and control groups increased with time, with increase in the mean values for ha coated group than that for control one in 1 and 2 week intervals. regarding the osteoclasts number, the mean values were in week 2 for both groups with less osteoclasts number in ha treated group than that of control one at the same interval. statistically all histomorphometric variables, showed a highly significant difference between the control and experimental groups in all healing intervals except osteoblasts and osteocytes number that showed non-significant difference in 2 and 4weeks , and non-significance differences were noted with osteoclasts in all healing intervals (table 2). table (1) descriptive statistics for bone architecture parameters for all groups. variables duration control group experimental group n mean s.d. s.e. min. max. n mean s.d. s.e. min. max. cortical bone thickness 1 weeks 5 0.87 0.04 0.02 0.79 0.97 5 2.02 0.04 0.02 1.9 2.1 2 weeks 5 1.84 0.03 0.01 1.79 1.87 5 2.8 0.06 0.02 2.7 2.9 4 weeks 5 2.07 0.13 0.05 1.82 2.21 5 3.3 0.13 0.04 3.1 3.5 trabecular width 1 weeks 5 0.13 0.01 0.003 0.12 0.14 5 0.46 0.01 0.003 0.45 0.48 2 weeks 5 0.21 0.004 0.001 0.21 0.22 5 0.6 0.04 0.02 0.56 0.7 4 weeks 5 0.34 0.01 0.003 0.33 0.35 5 0.75 0.02 0.01 0.69 0.78 thread width 1 weeks 5 0.24 0.017 0.006 0.22 0.26 5 0.63 0.03 0.01 0.6 0.67 2 weeks 5 0.32 0.02 0.006 0.3 0.35 5 0.73 0.02 0.008 0.71 0.79 4 weeks 5 0.33 0.04 0.014 0.28 0.39 5 0.75 0.32 0.01 0.72 0.79 marrow space star volume 1 weeks 5 0.055 0.001 0.001 0.05 0.06 5 0.009 0.003 0.001 0.001 0.01 2 weeks 5 0.052 0.003 0.001 0.052 0.06 5 0.007 0.001 0.001 0.004 0.009 4 weeks 5 0.035 0.001 0.001 0.032 0.04 5 0.001 0.001 0.0001 0.0008 0.001 osteoblasts no. 1 weeks 5 4.9 2.6 0.9 2 10 5 7.25 1.38 0.49 6 10 2 weeks 5 11.2 4.6 1.6 5 19 5 15.1 5.27 1.86 10 25 4 weeks 5 16.3 9.5 3.3 9 32 5 13.88 8.32 2.94 8 31 osteocytes no. 1 weeks 5 0 0 0 0 0 5 2 1.07 0.37 1 4 2 weeks 5 7.2 4 1.4 3 13 5 9 4.27 1.51 3 15 4 weeks 5 10.7 4.4 1.5 3 16 5 10.5 4.59 1.62 3 17 osteoclasts no. 1 weeks 5 0.25 0.46 0.16 0 1 5 0.38 0.51 0.18 0 1 2 weeks 5 1.38 1.5 0.53 0 4 5 1 1.41 0.5 0 4 4 weeks 5 0.88 0.83 0.29 0 2 5 0.88 0.64 0.22 0 2 j bagh college dentistry vol. 30(2), june 2018 histological and oral diagnosis 14 table (2) groups' comparison for all histomorphometric variables in each duration variables duration groups' comparisons d.f.** = 14 t-test p-value* cortical bone thickness 1 week 49.246 0.000 (hs) 2 weeks 43.472 0.000 (hs) 4 weeks 18.407 0.000 (hs) trabecular width 1 week 73.462 0.001 (hs) 2 weeks 25.602 0.000 (hs) 4 weeks 44.635 0.001 (hs) thread width 1 week 32.694 0.000 (hs) 2 weeks 38.75 0.000 (hs) 4 weeks 22.896 0.000 (hs) marrow space star volume 1 week -31.679 0.000 (hs) 2 weeks -38.922 0.000 (hs) 4 weeks -64.134 0.000 (hs) osteoblasts no. 1 week 2.287 0.038 (s) 2 weeks 1.563 0.14 (ns) 4 weeks -0.56 0.584 (ns) osteocytes no. 1 week 5.292 0.000 (hs) 2 weeks 0.839 0.415 (ns) 4 weeks -0.111 0.913 (ns) osteoclasts no. 1 week 0.509 0.619 (ns) 2 weeks -0.513 0.616 (ns) 4 weeks 0.0 1.0 (ns) * hs: highly significant, s: significant, ns: non-significant, **d.f. = degree of freedom discussion: the goal of present study was to evaluate the effects of hyaluronic acid on bone-implant interface. hyaluronan is considerd to be one of the fundamental constituent of connective tissue and bone marrow extracellular matrix. it plays an essential function in regeneration and repair of tissue (5). due to its osteogenic induction ability, biocompatibility and non-immunogenic nature led to its use in a number of clinical applications, such as fabricating and/or coating an implant or other structure to be inserted into bone or osseous tissue and to facilitate the healing and regeneration of bone (7). for both control and experimental groups the histological observations revealed that all sections run in a good healing path with variance in bone deposition and remodeling rate for each healing intervals. after one week of implantation in control animals, the sections showed clear blood clot replacement by granulation tissue containing abundant collagen fibers, considerable number of fibroblasts and osteoblasts with starting of osteoid tissue formation. while in ha treated implant the granulation tissue were already started to be replaced by new bone by osteoblast differentiation. this findings agree with mendes et al., 2010 (9) which confirmed the healing of upper first molar extraction socket in rat treated with ha was fast and more organized bone matrix formation after one week due to deposition of bone trabeculae. also in agreement with baisse et al., 2004 (10) who mentioned that after i week of rabbit tooth extraction and ha application in socket promoted and facilitated blood clot substitution by granulation tissue promotes alveolar bone consolidation with an evidence of filling at the apex with fine, nascent bridges. after two weeks interval the histological sections of control group showed delicate bone trabeculae with newly formed woven bone. while ha treated group showed more and thicker bone trabeculae than that of control one. these findings were in agreement with sanz et al. (11) who noticed that after two weeks of ha treated sockets after rat tooth extraction, more j bagh college dentistry vol. 30(2), june 2018 histological and oral diagnosis 15 bone trabeculae was formed when compared with that in control one. at four weeks interval the histological sections showed immature bone in control group while well developed, mature (lamellar) bone formation in experimental ones. this result in agreement with previous study done by elkarargy (12) who found that the mixing of hyaluronic acid with hydroxyapatite/beta tricalcium phosphate induced more bone formation efficiently in comparison with using of hydroxyapatite /beta tricalcium phosphate alone. the equality of means and variance of all parameters tested for micro architecture records between control and experimental groups illustrated a high value in experimental groups than those of control groups, this result can be explained on a fact of early induction of the progenitor cells to be differentiated into osteoblasts and enhancement of osteoid tissue formation. entrapment of osteoblast in their matrix led to osteocyts formation. more and faster bone matrix construction resulted from more osteoblast formation and consequently more osteocytes. the results also showed that there was a significant difference in bone architecture parameters in different intervals time. increase in trabecular width, cortical width, thread width, and trabecular number in 2and 4 weeks in comparison to 1 weeks which could be attributed to time spending for bone deposition and maturation, while the decrease in bone marrow star volume with the time could be due to the fact that faster building of bone matrix, bone trabeculae width will be more wider and there will be less bone star volume (v). these finding were agree with the study done by depprich et al. (13) who found that the histomorphometric analysis revealed an enhanced bone-to implant contact for every healing period. the results also showed that there was a significant difference in bone architecture parameters in different intervals time. increase in trabeculae width, and cortical width resulted in decrease of (v), while the decrease in number of osteoblasts and increase in number of osteocytes with increase time could be explained on a fact that any new tissue formation needs for more osteoblasts, when the formation of the bone settled and reached to its final measurement no more osteoblasts are required except for preservation of the biological activity. this results agree with al-molla et al. (14) and almolla (15) who found that the number of osteoblasts decrease by the time while osteocytes number increased between the groups in second week & 4 week intervals. conclusion results obtained in this study have shown that hyaluronic acid is osteoconductive material that enhance and accelerates osseointegration around titanium implant by stimulating the osteogenic mesenchymal tissue and osteoblast differentiation and then early apposition of osteoid tissue. references 1. oshida y, tuna e, aktören o, gençay k. dental implant systems. int j mol sci.2010; 11(4): 1580 – 1678. 2. papaspyridakos, p. mokti, m., chen, c. j., benic, g. i.; gallucci, g. o., chronopoulos, v implant and prosthodontic survival rates with implant fixed complete dental prostheses in the edentulous mandible after at least 5 years: a systematic review. clin implant dent relat res. 2014.16 (5): 705–717. 3. frisardi g, barone s, razionale av, paoli a, frisardi f, tullio a, lumbau a, chessa g. biomechanics of the press-fit phenomenon in dental implantology: an image-based finite element analysis. head face med, 2012;8:18. 4. belém a, scombatti s, martins r, yamashina k, iezzi g, piattelli a. influence of implant surfaces on osseointegration. braz dent j, 2010; 21(6): 471-481. 5. prince cw. roles of hyaluronan in bone resorption bmc. disord.2004 5:12. 6. seebeck p. hyaluronic acid (hyaluronan), clinical and technical review. teco medical group, switzerland 2011. 3.16. 7. sanz em, ossipov da, hilborn j, larsson s, jonsson kb, varghese op. bone reservoir: injectable hyaluronic acid hydrogel for minimal invasive bone augmentation. j. control release 2011; 152: 233– 241. 8. collins tj. image j. for microscopy. biotechniques 2007; 43 (1suppl): 25–30. 9. mendes rm, silva ga, caliari mv, silva ee, ladeira lo, ferreira aj. effects of single wall carbon nanotubes and its functionalization with sodium hyaluronate on bone repair. j life sciences 2010; 87: 215–222 10. baisse e, piotrowski b, piantoni p, brunel g. action of hyaluronic acid on the wound healing process following extraction. experimental study. j clinic. patho 2004; 7:380-390. 11. sanz em, ossipov da, hilborn j, larsson s, jonsson kb, varghese op. bone reservoir: injectable hyaluronic acid hydrogel for minimal invasive bone augmentation. j. control. release 2011; 152: 233– 241. 12. elkarargy a. alveolar sockets preservation using hydroxyapatite / betatricalcium phosphate with hyaluronic acid (histomorphometric study). j amer sci 2013; 9(1): 556-63. 13. depprich r, zipprich h, ommerborn m, naujoks c, wiesmann h, kiattavorncharoen s, lauer h, meyer u, kübler n, handschel j. osseointegration of https://www.ncbi.nlm.nih.gov/pubmed/23311617 https://www.ncbi.nlm.nih.gov/pubmed/?term=frisardi%20g%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=barone%20s%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=razionale%20av%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=paoli%20a%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=frisardi%20f%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=frisardi%20f%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=tullio%20a%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=lumbau%20a%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/?term=chessa%20g%5bauthor%5d&cauthor=true&cauthor_uid=22642768 https://www.ncbi.nlm.nih.gov/pubmed/22642768 j bagh college dentistry vol. 30(2), june 2018 histological and oral diagnosis 16 zirconia implants compared with titanium: an in vivo study. head & face medicine, 2008; 4:30. 14. al-molla b.the effects of the iraqi propolis on the artificial bony defects on the rabbit’s mandible. msc thesis in oral histology, university of baghdad. 2010. 15. al-molla b. evaluation the effects of amelogenin/propolis coating on osseointegration of cp ti implant surface in rabbits. 2014. vol. 1/ issue 3. dropbox 4 karar f 20-24.pdf simplify your life microsoft word 4 zainab musa ortho j bagh college dentistry vol. 32(3),september 2020 natural head different 19 natural head position: a review zainab mousa kadhom (1), noor jumaa (2) article doi: https://doi.org/10.26477/jbcd.v32i3.2896 abstract objectives: although the frankfort horizontal (fh) and sella-nasion were routinely used as craniofacial reference planes, the inter-individual orientations were changeable when related to true horizontal (hor). natural head position (nhp) is a reproducible, standardized position, with the head in an upright posture and eyes focused on a point in the distance at eye level so that the visual axis is horizontal. the natural head position has importance in anthropological as well as in orthodontic fields, as this position has a relatively fixed relationship to the true horizontal and vertical planes. however, nhp is clinically not simple and it takes long time to be recorded, in addition to a deficiency in the tools utilized in the nhp and lack in the staff training. this paper aims to shed the light on different methods of nhp registration and reproduction. data and sources: a literature review of english articles was performed using pubmed, scopus, and google scholar to search for natural head position in orthodontics. conclusions: nhp is affected by many factors, and it is different in walking state than in static state. there are various cephalometric or photographic methods for nhp recording. keywords: reproducibility of natural head position, true horizontal, true vertical plane. (received: 25/7/2019; accepted: 25/8/2019) introduction when a person is looking at a far point at eye level with a standardized orientation of the head in space, this is called natural head position (nhp),(1) or at the distant objects like the light source at eye level or one's eyes reflection in a mirror. (2) the functional position of the head that differs in the sitting and standing subject and it oscillates around the individual’s mean. nhp is also known as natural head posture. moorrees and kean(3) were the first to explain the natural head orientation and rectified the people with “tenseness” in their natural head position. lundström and lundström(4) defined it as when the doctor assists the subject to orient his head, according to the clinical expertise, when body of the person is relaxed and he is looking at a distant point at level of the vision. the natural head posture concept is not modern. leonardo da vinci (14521519) and albrecht dürer (14711528) used scaffoldings of horizontal and vertical lines on drawings of models positioned in ''natural pose'' to allow more precise scientific and artistic replication of the human head.(5) sella– nasion (sn) plane is a commonly used craniofacial reference plane.(6) this plane represented the anterior cranial base; so it is reliable, biologically meaningful and when concerned to vertical plane it has large inter-individual standard deviations.(4) the frankfort horizontal is not used for orienting natural head position, but it is very useful in skull investigations because the frankfort plane is positioned in the living and it is usually distributed around extra cranial horizontal.(1) an extra cranial reference line is used instead of intracranial reference lines, so the natural head position (nhp) is regarded as the basis of meaningful cephalometric analysis that is subjected to large biological changes in their gradient.(7) natural head position has been used by some of anatomists and anthropologists to study the human face throughout the ages. craniologists realized that skulls also had to be oriented in a way approximating the natural head position of the living. (1) lecturer in orthodontic department, college of dentistry, university of baghdad, iraq. (2) dentist, ministry of health, iraq. corresponding e-mail:, schati1981@yahoo.com the natural head position has been involved in conducting important comparative studies of crania from various racial populations. also, to define a plane for orienting crania in a manner conforming to the natural head position of the living. interest concentrates on presence of a posterior landmark for a plane through the lowest part of the orbits that would approximate a true horizontal extra cranial plane. porion was taken as the most appropriate landmark.(1) madsen (2) showed that the comparison of the craniofacial morphological elements of morphology to selected reference planes was considered as a base of contemporary cephalometric analysis in orthodontics. preferably, a valid cephalometric reference plane system should have many properties: intra-individual reproducibility and reliability (low method error), perfection, the direction in average close to true vertical (ver) or true horizontal (hor) and low inter-individual variability. the aim of this review is to shed the light on different methods of nhp registration and reproduction. factors affecting natural head position there are many environmental and physiological factors affecting natural head position. these factors include: 1. respiratory resistance vig et al. (8) explained three experiments through their study about experimental manipulation of head posture, dealing with the effect of visual feedback deprivation, total nasal obstruction and a combination of two on the posture of the cranium measured relative to a gravity-defined true vertical reference plane. they found that total nasal obstruction results in all cases in an extended head position. 2. craniofacial morphology: the natural head orientation (nho) is influenced by the facial morphology, and the chin position is a substantial factor affecting the nho consistently.(9) 3. walking: by means of eyewear inclinometer measurements, usmez et al. (10) studied the relationship between static natural head position and head position measured during walking and they compared walking with rigid head position. the mean walking head position was 4.6° inverted compared with the mean rigid head position. 4. altered vision: j bagh college dentistry vol. 32(3),september 2020 natural head different 20 studies have shown that head posture is dependent on vision. the head posture of normal subjects therefore can be anticipated to vary from that of blind subjects. many experiments showed more difference in head posture of the blind subjects. also, the head was tilted down in comparison to the control group (11). methods of recording natural head position von baer (1861)(12) described the first method for recording nhp, which was early work in the mirror guided visual technique of obtaining nhp. it seemed to be an accepted technique. in this method the persons sit on a chair comfortably and relaxed, they were asked to look into a mirror to see the image of their eyes, this mirror was founded at the same level with the pupils of their eyes. downs(13) provided a rational means of soft tissue profile typing clarifying harmonious dentofacial profiles from inharmonious ones. the lateral head profiles of 100 children had been photographed when standing and looking at their own eyes into a mirror. when those persons had no horizontal frankfort plane, a correction was made for them, and also if the discrepancies between facial typing disappear. self-balance position was got when the subject had the subject’s own feeling of natural head balance after head tilting exercises (moving their head back and forth) with little capacity.(14) the nhp had been transformed to a lateral cephalometric film by a method of photography. this was achieved by applying mølhave’s orthoposition to record a nhp for 52 persons when they stood looking into their eyes on a vertical mirror 1 m away, and teeth occlusion was made in centric slightly.(15) a fluid level device begun to be used firstly by showfety et al. (16) when the nhp of the subjects were put in the cephalostat when taking a lateral head film exposure. this small fluid device was mounted on a small pivot bracket and linked to the temple of the subject with double sided tape (fig. 1). the film had been exposed, when the subjects were directed to walk into the cephalostat, and the fluid level should be horizontal by resetting the inclination of subject`s head figure 1: the showfety fluid level, pivot hinge, and fluid level fixed to subject’s temple (16). raju et al. (17) transferred the true vertical reference line on the patients face itself in nhp to the conventional lateral cephalogram in a modified approach of the capture, in which a mirror 4x2 feet in size was fixed on the wall and the suspending weight of 4 kg on a 0.016 inch wire hung from the ceiling in front of the mirror as a plumb line was created to represent the true vertical. figure 2: two inclinometers for pitch and roll fixed to a pair of spectacles (10) could be used firstly by showfety et al. (16) when the nhp of the subjects was put in the cephalostat when taking a lateral head film exposure. this small fluid device was mounted on a small pivot bracket and linked to the temple of the subject with double sided tape (fig. 1). the film was exposed when the subjects were directed to walk into the cephalostat, and the fluid level should be horizontal by resetting the inclination of subject`s head. another study (10) used two inclinometers, one of them was put by pitch on one arm of the spectacles, and another represented the roll fixed on the other arm (fig. 2). while wearing the spectacles, the subjects were instructed to look into their eyes where they stood in front of a wall fixed mirror 1 m away. what is reproducibility of natural head position? bjern (18) recorded 35 subjects in nhp on three detached occasions to estimate the reproducibility of nhp. there was something wrong in the analysis method. there were differences between the maximum and minimum values of the 3 determinations of the angle sn/hor that were studied for standing persons. the reliability of the dental auxiliaries use in a routine method of recording the nhp could be examined. the material was comprised thirty orthodontic patients recorded on two occasions 1 to 35 days apart. the first and the second recordings for the patients were examined showing no systematic difference. (19) the validity and precision of nho was estimated by lundström and lundström.(20) they cut 27 lateral profile photographs of orthodontic patients into round forms and the orientation of these photographs were inspected by four examiners in natural head. they found a high correlation in orientating these profile photographs in evaluated nhp. the longitudinal reproducibility of nhp had been investigated primarily by cooke & wie.(21) their findings showed no significant differences when recording the nhp with or without ear posts use, but with a mirror the nhp reproducibility was better (method error 1.9°) than without a mirror (method error 2.7°). advantages of nhp  the inclination of an intracranial reference line was subjected to large biological changes more than the extra-cranial reference lines so these lines are used instead of intracranial ones, therefore, natural head position (nhp) was regarded as a base for cephalometric analysis (7).  its ease of recording and representation of a true life appearance (22).  the primary basis used in cephalometric analysis is the nhp (and a true vertical/horizontal), because this reference plane is efficient, more stable and gives a more significant cephalometric analysis and more j bagh college dentistry vol. 32(3),september 2020 natural head different 21 clinically pertinent diagnosis of skeleton-facial discrepancies.(23)  the important feature of the nhp: its intra-individual reproducibility is significantly less than the interindividual variability of conventional craniofacial reference planes, when both related to true vertical.(24) disadvantages of nhp  natural head position is not particularly simple in the clinical field; moreover, it is time consuming (25).  some people hold their head in an extended unnaturally or flexed position that may lead to faulty results if used for diagnosis (9).  there was a practical constraint in workers practice and equipment used in nhp recording, therefore, it is not widespread (2). conclusion the use of nhp as a craniofacial system represents a correct alteration of classical craniofacial reference planes since it truly represents the head orientation, registered easily, and it has good intra-individual reproducibility. natural head position has essential importance to orthodontists before facial cephalograms taking; it has been shown to be the most accurate and reproducible head position. moreover, there are different applications of nhp in orthodontic sphere for diagnosis and research purposes. many methods are used to register the nhp, these methods are conducted either by cephalometric x-ray or photographs. references 1. jacobson a. radiographic cephalometry: from basics to videoimaging. 1st ed. chicago: quintessence publishing co, 1995. 2. madsen dp, sampson wj, townsend gc. craniofacial reference plane variation and natural head position. eur j orthod. 2008;30(5):532-40. 3. solow b, tallghen a. natural head position in standing subjects. acta odontol scand. 1971; 29(5): 591-607. 4. moorrees cfa, kean mr. natural head position, a basic consideration in the interpretation of cephalometric radiographs. am j phys anthropol. 1958; 16(2): 213-34. 5. popham ae. the drawings of leonardo da vinci. the reprint society ltd. by arrangement with jonathan cape. bungay, suffolk, england: 1952: plates 216 and 217 [cited by: cooke ms, wei shy. the reproducibility of natural head posture: a methodological study. am j orthod dentofacial orthop. 1988; 93(4): 280-88]. 6. broadbent bh. a new x-ray technique and its application to orthodontia. angle orthod. 1931; 1(2): 45-66. 7. lundström a, lundström f, lebret lm, moorrees cf. natural head position and natural head orientation: basic considerations in cephalometric analysis and research. eur j orthod. 1995; 17(2): 111-20. 8. vig ps, showfety kj, phillips c. experimental manipulation of head posture. am j orthod. 1980; 77(3): 258-68. 9. halazonetis dj. estimated natural head position and facial morphology. am j orthod dentofacial orthop. 2002; 121: 364-68. 10. üs¸ümez s, orhan m. inclinometer method for recording and transferring natural head position in cephalometrics. am j orthod dentofacial orthop. 2001; 120(6): 664-70. 11. fjellvang h, solow b. craniocervical postural relations and craniofacial morphology in 30 blind subjects. am j orthod dentofacial orthop. 1986; 90(4): 327-34. 12. von baer ke, wagner r. bericht uber die zusammenkunft einiger anthropologen im september 1861 in gottingen zum zwecke gemeinsamer besprechungen. leipzig: leopold voss, 1861 [cited by: cooke ms, wei shy. the reproducibility of natural head posture: a methodological study. am j orthod dentofacial orthop. 1988; 93(4): 280-88]. 13. downs wb. analysis of the dentofacial profile. angle orthod. 1956;26(4):191212. 14. mølhave a. en biostatisk undersogelse. menneskets stdende stilling teoretisk og statometrisk belyst. with an english summary. (a biostatic investigation ofthe human erect posture). 1958. munksgard, copenhagen [cited by: solow b tallghen a. natural head position in standing subjects. acta odontol scand. 1971; 29(5): 591-607]. 15. mcwilliam js, rausén r. analysis of variance in assessing registrations of natural head position. swed dent j suppl. 1982; 15: 239-46. 16. showfety kj, vig ps, matteson s. a simple method for taking natural-headposition cephalograms. am j orthod. 1983; 83(6):495-500. 17. raju ns, prasad kg, jayade vp. a modified approach for obtaining cephalograms in the natural head position. j orthod. 2001; 28: 258. 18. bjerin r. a comparison between the frankfort horizontal and the sella turcicanasion as reference planes in cephalometric analysis. acta odontol scand. 1957; 15(1):1-13. 19. siersbaek-nielsen s, solow b. intraand interexaminer variability in head posture recorded by dental auxiliaries. am j orthod. 1982; 82(1): 50-7. 20. lundström a, lundström f. the frankfort horizontal as a basis for cephalometric analysis. am j orthod dentofacial orthop. 1995; 107(5): 537-40. 21. cooke ms, wei sh. cephalometric standards for the southern chinese. eur j orthod. 1988; 10(1): 264–72. 22. cooke ms, wei sh. a summary five-factor cephalometric analysis based on natural head posture and the true horizontal. am j orthod dentofacial orthop. 1988; 93(3): 213-23. 23. madsen dp. natural head position: a photographic method and an evaluation of cranial reference planes in cephalometric analysis. a ph.d. thesis. the university of adelaide, australia, 2007. 24. periera al, d-marchi lm, scheibel pc, ramos al. reproducibility of natural head position in profile photographs of children aged 8 to 12 years with and without the aid of a cephalostat. dental press j orthod. 2010;15(1):65-73. 25. mcguinness nj, mcdonald jp. change in natural head position observed immediately and one year after rapid maxillary expansion. eur j orthod. 2006; 28(2): 126 134. j bagh college dentistry vol. 32(3),september 2020 natural head different 22 مستخلص ال تكون ذات من الشائع استخدام المستويات المرجعية القحفية مثل فرانكفورت االفقي وسيال ناسون.هذه المستويات لها توجيه متغير بين االفراد عندما الحقيقي. وضع الراس الطبيعي هو وضع موحد قابل للتكرار عندما يكون الراس بوضع مستقيم و العينين مركزة على نقطة على مسافة صلة باالفقي ,هذا الوضع بمستوى العينين بحث يكون المحور البصري افقي. وضع الراس الطبيعي له اهمية في مجال علم االنسان اضافة الى مجال تقويم االسنان القة نسبية مع المستوى االفقي والعمودي الحقيقي.لكن وضع الراس الطبيعي سريريا ليس بالبسيط ويستغرق وقتا طويال عندتسجيله, باالضافةلديه ع ة بحال الى ذلك هناك نقص باالدوات المستعملة بوضع الراس الطبيعي واالفتقار الى كادر متدرب. وضع الراس الطبيعي يتاثر بعدة عوامل,هو مختلف ت متنوعة طرق الثبات.هنالك بحالة عنه الطبيعي المشي الراس وضع لتسجيل طرق ستعمل او الجانبية االشعة طريق عن تكون قد الطرق هذه .تصويرية dropbox 6 maha f 31-36 .pdf simplify your life dropbox 07 sura 33-38.pdf simplify your life maha.doc j bagh college dentistry vol. 27(1), march 2015 phototoxic effect oral and maxillofacial surgery and periodontics 144 phototoxic effect of visible blue light on aggregatibacter actinomycetemcomitans and porphyromonas gingivalis in patients with chronic periodontitis (an in-vitro study) ali r. abdulazeez, b.d.s (1) maha s. mahmood, b.d.s., m.sc. (2) wifaq m. ali, m.b.ch.b., f.i.c.m.s. (3) abstract background: the aim of this study was to determine phototoxic effect of visible blue light on anaerobic periodontal pathogens namely aggregatibacter actinomycetemcomitans and porphyromonas gingivalis. materials and methods: strains of aggregatibacter actinomycetemcomitans and porphyromonas gingivalis were isolated from pockets of systemically healthy patients aged between 35-55 years old with pocket depths of 5-6 mm, the bacteria cultured on special blood agar plates solid media, then subjected to visible blue light emitted from commercially available light cure devise (led curing light); that emits blue light (400-500nm) of 1000mw energy at different periods of time exposures, then the cfu of each plate was measured by direct colony count with the aid of open cfu software after 48hours of anaerobic incubation. results: there was a decrease in cfu for both microorganisms as we proceeded from zero, 20, 40 and 60 seconds of blue light exposure. conclusion: there was a phototoxic effect for the visible blue light emitted from the light curing device against the anaerobic periodontal pathogens. key words: blue light, cfu, anaerobic periodontal pathogen. (j bagh coll dentistry 2015; 27(1):144-150). introduction chronic periodontitis is a quite common disease in adult patients characterized by pocket formation and/or recession while progressive loss of periodontal attachment occurs slowly to moderately local risk factors, e.g. bacterial plaque [1] .wide array of microorganisms have been associated with periodontal disease, out of which aggregatibacter actinomycetemcomitans (aa) and porphyromonas gingivalis (pg) have been predominantly associated with periodontal diseases. the treatment of periodontal disease has always been inclined toward the disruption of these microbial floras either through mechanical therapy or by the use of antimicrobial agents [2].hand instrumentation is still considered the gold standard and allows the sufficient cleaning of the periodontal pockets .anatomical peculiarities like root curvatures or invaginations can make it difficult to remove bacterial deposits and biofilms completely from root surfaces by means of mechanical methods .several treatment options are available to support the efficacy of instrumentation, for example the usage of local antibiotics or antimicrobials .or photodynamic therapy (pdt) [3].different types of antibiotics have been used to avoid this obstacle. but another (1) m.sc. student. department of periodontics. college of dentistry, university of baghdad. (2) assistant prof. department of periodontics. college of dentistry, university of baghdad. (3) assistant prof. unite of infectious and systemic diseases, college of medicine, university of baghdad. problem was noted as biofilm showed antibioticresistance mechanisms [4-6] one of the problems that tackle the use of chemical agents is the failure in maintaining therapeutic concentrations in the targeted site and disruption of the oral microflora [7]. photodynamic therapy (ptd) thus was introduced to open a new path in treating periodontal diseases without being hindered by the obstacles and problems mentioned above, ptd contains three major components: visible light, a nontoxic photosensitizer, and oxygen [8] the function of the exogenous photosensitizers is to absorb the visible light that matches the wavelength of their peak absorption, then causing a photochemical mechanism that kills bacterial [9-11]. interestingly, some bacteria can be eliminated without needing an exogenous photosensitizer. among which are the blackpigmented bacteria (bpb), it was assumed that excitation of their endogenous porphyrins will result in the death of bacteria [12]. the bpb species found in the oral cavity can tolerate low concentrations of oxygen comparable to those levels in untreated human periodontal pockets although they are classified as anaerobes, these small amounts of oxygen render periodontal diseases susceptible to photodynamic therapy (pdt) [13]. low-energy argon laser irradiation was proven to have phototoxic effects on porphyromonas; prevotella species [14,15].while similar effects were observed when utilizing visible light against porphyromonas gingivalis and fusobacterium j bagh college dentistry vol. 27(1), march 2015 phototoxic effect oral and maxillofacial surgery and periodontics 145 nucleatum without an exogenous photosensitizer [16,17]. materials and methods patient selection and sampling twelve systemically healthy patients of age range between 35-55 years old participated in this study, they had chronic periodontitis with at least one pocket of 5-6mm depth. a piece of plaque from periodontal pocket was excavated by gracey curette without touching adjacent tissue. plaque sample was spread on blood agar solid media supplied with selective materials in the plates then plates were transported into an anaerobic jar with anaerobic gas pack incubated anaerobically for 72 hours. after incubation, bacterial identification was based on (the microscopic appearance and colonial shape and size, gram stain, biochemical tests like catalyse, haemolytic capability, urease test, and antibiotic susceptibility tests). aggregatibacter actinomycetemcomitans colonies showed a convex white starry appearance with no black pigmentation [fig 1]. they were gram negative with rod shaped appearance under microscope, catalyse positive, coagulase negative , urease negative, had a beta haemolytic activitiy and were resistant to clindamycin and metronidazole but sensitive to kanamycin. porphyromonas gingivalis colonies were dull colored round convex colonies, clearly distinguished by the presense of black pigmentation [fig 2], they were gram negative with rod shaped (sometimes encapsulated) under microscope, catalyse negative, urease negative, had a weaker haemolytic activity, and susceptible to clindamycin and metronidazol colonies were subcultered again on the same media anaerobically for 72 hours under the same condition,using the same method, to obtain pure cultures of both aggregatibacter actinomycetemcomitans and porphyromonas gingivalis. the application of light exposure using a serial dilution technique on microtiter plates: after incubation period, a serial dilution procedure was performed for standardization of the amount of bacteria using 106 as bacterial initial concentration, and to decrease the numbers of colonies into a countable one. a standard volum of thioglycolate broth which is liquid media used to culture bacteria anarobically containing special reducing agents to be dispersed in each well of microtiter 96 well, (150 µl), then a single colony of each micro-organism was carefully chosen and mixed into the well of broth, from that well, we proceeded in dilution on 1:10 rate until we reached the 5th dilution. four plates of enriched solid blood agar media were prepared for each bacteria; spreading broth taken from 5th dilution well on each plates then exposed to different periods of light exposure, a light beam of blue light was directed on the plate. starting from zero/seconds(no light exposure) for the first plate, then 20, 40, 60 for the 2nd 3rd and 4th plate respectively; tip of the light cure devise is standardized with the center of light beam was directed towards the center of plate for all experiments. then all plates were incubated anaerobically. counting cfu the total colonial count was achieved using computerized program when needed named open fig 1: aggregatibacter actinomycetemcomitans with its white starry shape fig 2: porphyromonas gingivalis with black pigmentation clearly seen on plate j bagh college dentistry vol. 27(1), march 2015 phototoxic effect oral and maxillofacial surgery and periodontics 146 cfu ver. 3.8.11, on day 13, the cfu’s were counted by direct vision and with the use of “open cfu” software when conformation was needed. the plate that has no light exposure (zero second groups) for each micro-organism considered the control plate with which we compared the results of the remaining 3 plates. the whole procedure was repeated for each one of the 12 samples of patients who participated in the study. results a high significant statistical difference was observed in comparing the cfu count of aggregatibacter actinomycetemcomitans at different periods of time of blue light exposure [table 1] illustrates median value of cfu count of aggregatibacter actinomycetemcomitans at different periods of blue light exposure, showing a decrease in cfu count as we proceeded from zero to 60 seconds of blue light exposure [fig 3] and [fig 4]. in intergroup comparison [table 2], cfu count of aggregatibacter actinomycetemcomitans at each period of light exposure time was compared to the cfu count at all the periods of light exposure. table 1: median value of aggregatibacter actinomycetemcomitans cfu at different light exposure time time (sec.) median mean rank x 2 d.f. p-value significance control (zero) 358 37.67 20.61 3 0.000 hs 20 194 27.54 40 142.5 19.75 60 101 13.04 *kruskal-wallis test was used table 2: intergroup comparison between aggregatibacter actinomycetemcomitans cfu of each two groups of light exposure time time (sec.) mann-whitney u test p-value control vs. 20 sec. 34 0.028 (s) control vs. 40 sec. 15 0.001 (hs) control vs. 60 sec. 9 0.000 (hs) 20 sec. vs. 40 sec. 46 0.133 (ns) 20 sec. vs. 60 sec. 23.5 0.005 (hs) 40 sec. vs. 60 sec. 46 0.133 (ns) fig. 3: time of light exposure vs. the cfu of aggregatibacter actinomycetemcomitans a b c d j bagh college dentistry vol. 27(1), march 2015 phototoxic effect oral and maxillofacial surgery and periodontics 147 fig. 4: decrease of aggregatibacter actinomycetemcomitans cfu as we proceed from a: zero seconds of light exposure b: 20s, c:40s and d: 60s there was a high significant statistical difference between: the control group (had no light exposure) and the 60 second group, control group and the 40 second group, the 20 second group and the 60 second of light exposure group[fig 5].there was significant statistical difference between the control group and the 20 second group.there was no significant statistical difference between the 40 second group and the 60 second group, the 20 second group and the 40 second group.it’s very obvious that the p-value decreased as the time difference increased between groups until reaching the highest significant value (0.00) when the difference was 60 seconds. a significant statistical difference was observed in comparing the cfu count of porphyromonas gingivalis at different periods of time of blue light exposure [table 3] illustrates median value of cfu count of porphyromonas gingivalis at different periods of blue light exposure, showing a decrease in cfu; as we proceeded from zero to 60 seconds of blue light exposure [fig 6] and [fig 7]. in intergroup comparison [table 4], cfu of porphyromonas gingivalis at each period of light exposure time was compared to the cfu at all the periods of light exposure. there was a high significant statistical difference between the control group (had no light exposure) and the 60 second group [fig 8]. there was significant statistical difference between the 20 second group and the 60 second group, the 40 second group and the 60 second group. there was no significant statistical difference between the control group and the 20 second group, the control group and the 40 second group, the 20 second group and the 40 second group. p-value decreased as the time difference increased between groups reaching the highest significant value (0.003) when the difference was 60 seconds. fig 5: difference of aggregatibacter actinomycetemcomitans cfu between the (a) control plate (zero light exposure) and (b) the 60 seconds exposure plate. table 3: median value of porphyromonas gingivalis cfu at different light exposure time time (sec.) median mean rank x 2 d.f. p-value significance control (zero) 277.5 32.29 10.431 3 0.015 sig 20 202.5 26.29 40 177 25.21 60 125 14.21 j bagh college dentistry vol. 27(1), march 2015 phototoxic effect oral and maxillofacial surgery and periodontics 148 fig. 6: time of light exposure vs. the cfu porphyromonas gingivalis a b c d fig. 7: decrease of porphyromonas gingivalis cfu as we proceed from a: zero seconds of light exposure through b: 20s, c: 40s and d: 60s seconds. table 4: intergroup comparison between cfu of porphyromonas gingivalis of each two groups of light exposure time time (sec.) mann-whitney u test p-value control vs. 20 sec. 50 0.204 (ns) control vs. 40 sec. 52 0.248 (ns) control vs. 60 sec. 20.5 0.003 (hs) 20 sec. vs. 40 sec. 65.5 0.707 (ns) 20 sec. vs. 60 sec. 35 0.033 (s) 40 sec. vs. 60 sec. 37 0.043 (s) a b fig 8: difference of porphyromonas gingivalis cfu between (a) the control plate (zero light exposure) and (b) the 60 seconds exposure plate discussion results regarding porphyromonas gingivalis obtained from this research came in agreement with a study done by feuerstein et al. who suggested a phototoxic effect of visible blue light on gram negative anaerobic periodontal pathogens without use of exogenous photosensitizer [16]. results regarding porphyromonas gingivalis came in agreement also with a study done by hyun-hwa song et al. but in disagreement with the same study as much as its concerned with aggregatibacter actinomycetemcomitans results where he found no significant phototoxic effect of visible blue light against it, he found that there was a phototoxic effect of visible blue light emitted from a halogen light curing device source j bagh college dentistry vol. 27(1), march 2015 phototoxic effect oral and maxillofacial surgery and periodontics 149 on planktonic anaerobic periodontal pathogens, but suggested the use of exogenous photosensitizer if this method was to be used clinically, to increase the phototoxic effect.[18] . a high significant statistical difference was observed in comparing the cfu of aggregatibacter actinomycetemcomitans at different periods of time of blue light exposure , and there was a significant statistical difference was observed in comparing the cfu of porphyromonas gingivalis at different periods of time of blue light exposure.this can be explained by the decrease of bacterial cfu of both aggregatibacter actinomycetemcomitans and porphyromonas gingivalis directly with the period of exposure to the curing blue light. the decrease of bacterial cfu is explained by the killing ability of light and temperature against these bacteria, visible light (408-750 nm) has been found to be mutagenic and to cause metabolic and membrane damage to bacteria, oxidative stress occurs with reactive oxygen species such as superoxide anion, hydrogen peroxide, and hydroxyl radicals that damage proteins, dna, lipid, and the cell membrane. light sources have considerably stronger effects with reactive oxygen radicals who occur in combined form with natural photosensitizers, such as humic acid or protoporfirin, it was also found that enzyme synthesis such as super oxide dismutase and catalyse have been shown to decrease with the effects of light independently [19] . the accumulative effect of light as time of exposure increases produces a decrease in the cfu count. in intergroup comparison of aggregatibacter actinomycetemcomitans there was a high significant statistical difference between: the control group (had no light exposure) and the 60 second group, control group and the 40 second group, the 20 second group and the 60 second of light exposure group. there was significant statistical difference between the control group and the 20 second group. there was no significant statistical difference between the 40 second group and the 60 second group, the 20 second group and the 40 second group. the intergroup comparison regarding the porphyromonas gingivalis, there was a high significant statistical difference between the control group (had no light exposure) and the 60 second group, there was significant statistical difference between the 20 second group and the 60 second group, the 40 second group and the 60 second group, and there was no significant statistical difference between the control group and the 20 second group, the control group and the 40 second group, the 20 second group and the 40 second group. this suggests clearly that the effect of blue light exposure increases as the time of exposure increases, whenever the difference of blue light exposure time between groups increases, the difference between cfu’s was more significant, and the best results were obtained when there was a (60 seconds) difference, the results of comparison was high significant in both organisms. as conclusion, there was a phototoxic effect for the visible blue light emitted from the light curing device against the anaerobic periodontal pathogens. references 1. schmidt j, jentsch h, stingu cs, sack u. general immune status and oral microbiology in patients with different forms of periodontitis and healthy control subjects. 2014 plos one 9(10): e109187. doi: 10.1371/journal.pone.0109187 2. praveen nc, rajesh a, madan m, chaurasia vr, hiremath nv, sharma am. in vitro evaluation of antibacterial efficacy of pineapple extract (bromelain) on periodontal pathogens. j int oral health 2014; 6(5): 96–98. 3. berakdar m, callaway a, fakhr eddin m, roß a, willershausen b. comparison between scaling-rootplaning (srp) and srp/photodynamic therapy: sixmonth study head face med 2012; 8: 12. 4. del pozo jl, patel r. the challenge of treating biofilm-associated bacterial infections. clin pharmacol ther 2007; 82: 204–9. 5. anderson gg, o'toole 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[ivsl] 8. meyer dh, sreenivasan pk, fives-taylor pm. evidence for invasion of a human oral cell line by actinobacillus actinomycetemcomitans. infect immun. 1991; 59: 2719–26. 9. sharman wm, allen cm, van lier je. photodynamic therapeutics: basic principles and clinical applications. drug discov today 1999; 4: 507–517. 10. maisch t, szeimies rm, jori g, abels c. antibacterial photodynamic therapy in dermatology. photochem photobiol sci 2004; 3: 907–17. 11. maisch t. anti-microbial photodynamic therapy: useful in the future? lasers med sci 2007; 22: 83–91. 12. soukos ns, som s, abernethy ad, ruggiero k, dunham j, lee c, doukas ag, goodson jm. j bagh college dentistry vol. 27(1), march 2015 phototoxic effect oral and maxillofacial surgery and periodontics 150 phototargeting oral black-pigmented bacteria. antimicrob agents chemother 2005; 49(4): 1391–6. 13. loesche wj, gusberti f, mettraux g, higgins t, syed s. relationship between oxygen tension and subgingival bacterial flora in untreated human periodontal pockets. infect immun 1983; 42: 659–67. 14. henry ca, judy m, dyer b, wagner m, matthews jl. sensitivity of porphyromonas and prevotella species in liquid media to argon laser. photochem photobiol 1995; 61:410–13. 15. henry ca, dyer b, wagner m, judy m, matthews jl. phototoxicity of argon laser irradiation on biofilms of porphyromonas and prevotella species. j photochem photobiol b 1996; 34: 123–8. 16. feuerstein o, persman n, weiss ei. phototoxic effect of visible light on porphyromonas gingivalis and fusobacterium nucleatum: an in vitro study. photochem photobiol 2004; 80: 412–15. 17. feuerstein o, ginsburg i, dayan e, veler d, weiss ei. mechanism of visible light phototoxicity on porphyromonas gingivalis and fusobacterium nucleatum. photochem photobiol 2005; 81: 1186–9. 18. hyun-hwa song, jae-kwan lee, heung-sik um, beom-seok chang, si-young lee, min-ku lee. phototoxic effect of blue light on the planktonic and biofilm state of anaerobic periodontal pathogens. j periodontal implant sci 2013; 43(2): 72–8. 19. karim e, rené s. a comparative study of the photoinactivation of bacteria by meso-substituted cationic porphyrin, rose bengal and methylene blue. desalination 2009; 246(1–3):353-362. [ivsl] j bagh college dentistry vol. 32(2), june 2020 evaluation of dental 17 evaluation of dental enamel color after fixed orthodontic therapy using two types of protectors to prevent white spot lesions (a prospective clinical study) yasir ruda allabban(1) article doi: https://doi.org/10.26477/jbcd.v32i2.2889 abstract background: the aim of this study is to evaluate the color change ∆e of the dental enamel following treatment with 2 kinds of protector (icon infiltrant, clinpro varnish) before fixed orthodontic treatment to avoid the possible white spot lesions. materials and methods: fifty four subjects treated with fixed appliances were divided into 3 groups: the 1st group was control, while the 2nd and 3rd groups were treated with icon infiltrant and clinpro varnish before bonding procedure, respectively. color parameters (l,a,b) were recorded for the middle and gingival thirds before and after bonding procedure to get the ∆e of each group. results: one-way anova test showed a non-significant difference in ∆e between the 3 groups at p value <0.05, while there were highly significant differences in value of ∆e between middle thirds and the gingival thirds in all groups. conclusion: the icon infiltrant and clinpro varnish have no effect on color of the enamel when used before the bonding procedure. color change ∆e occurring in middle third is higher than that of the gingival third. keywords: color change, protector, white spot lesions. (received:28/5/2019; accepted:30/6/2019) introduction white spot lesions (wsls) are white milky patches that develop around the brackets in fixed orthodontic treatment due to demineralization of dental enamel as this demineralization is due to plaque attack.(1) the wsl is a disappointing problem arising during and after fixed orthodontic treatment.(2) the aggressiveness of dental plaque increases due to change in oral microbiota and difficulty to maintain oral hygiene in the presence of fixed orthodontic appliance.(3) according to souza et al.(4) wsl occurs in approximately 50% of fixed orthodontic patients, this important problem motivates both the manufacturer and the researcher to do enough investigation for prevention and / or treatment of wsl.(5-9) that is why several products are available in the market for prevention and/or treatment of wsl. this study will focus on the icon infiltrant resin (dmg) and glass ionomer cement (clinpro xt varnish, 3m unitek) because it has been shown that the use of these products before bracket bonding would not interfere with or reduce the shear bond strength.(10) so it is wise to use one of these products before bonding particularly for risky patients who have incipient caries, history of wsl, non-cavity lesion and the unbalanced mouth with repeated acid attacks, so the demineralization process is faster than remineralization. (11) (1) assist. prof. in department of orthodontics, college of dentistry, university of baghdad. corresponding author, yassir.patent@gmail.com patients nowadays are not satisfied by correction of malocclusion only, but the color of the teeth plays an important role in the esthetic outcome.(1214) insufficient information about the enamel color behavior is available so far. this study aims to investigate the effect of the above mentioned two protectant materials on enamel color when used under the bracket. the first research hypothesis is that the dental enamel may become darker in color as a result of using those agents. the second hypothesis is that the dental enamel may behave in a different manner (regarding the color) due to materials difference. the third hypothesis is that enamel behavior after application of these materials will differ according to the regain and anatomy of the labial aspect. materials and methods the sample comprised of 54 individuals, 27 males and 27 females within an age range between 1840 years; all were candidates for fixed orthodontic therapy. all the details about this research were explained to them so they agreed and singed the consent form. the inclusion criteria: 1full permanent dentition and crowding less than 4 mm. 2no caries, restoration, prosthesis or decalcification in the teeth. 3no gingival inflammation. 4no smoking (15). all the patients received scaling and polishing prophylaxis, and were motivated to follow oral hygiene protocol including regular teeth brushing with fluoridated tooth paste and never use any mouth wash like chlorhexidine to avoid teeth https://doi.org/10.26477/jbcd.v32i2.2889 mailto:yassir.patent@gmail.com j bagh college dentistry vol. 32(2), june 2020 evaluation of dental 18 staining. all patients were prepared for bonding but before the bonding procedure took place all patients underwent color measurement recording for the gingival and middle thirds of the upper six anterior teeth by using spectrophotometer vita easy shade compact (vita zahn fabric, bad sackingen, germany).(15-16) the color of the teeth was explained by 3 parameters: (l, a, b) according to commission of international of del eclairage,(17) where the l parameter represents the value or degree of lightness in munsell system ranging from o (black) to 100 (white), while the “a” parameter represents a measure of redness (a>0) or greenness ((a<0) and b represent parameter of yellowness (b>0) or blueness (b<0). (18) to avoid any error in color measurement, the method was standardized to overcome any confounder variable, in which all measurements were done in the same environmental light. the easy shade device was used according to manufacturer instructions by the same operator who passed the calibration for using this device one week before starting this research.,(3) the operator recorded the (l, a, and b) variables for the middle and gingival thirds of each upper anterior tooth. the easy shade device was used by holding the sterile intra oral device tip (mouth piece) perpendicular to the labial surface of the tooth just touching the gingival margin (for gingival third), in the same manner the record for the middle third was by sliding the device tip to the center of the clinical crown.(15) after finishing color measurement registration for all patients included in this study, the sample was divided randomly into 3 groups (each group consisted of 9 males and 9 females): group one is a control group that received bonding in a conventional way without using any material before the bonding procedure, in the 2nd group we used icon (dmg, lambug, germany), a low viscosity infiltrant resin, before the bonding procedure, while in the 3rd group we used the clinpro xt varnish (3m unitek, landsber, germany), a glass ionomer cement, before the bonding procedure. both protective materials used in groups 2 and 3 were used according to manufacturer protocol as shown in table (1). (10) table 1: groups, material and application protocol used in the current study. in sequence after the application of icon to group 2 and clinpro to group 3 while leaving group 1 (control group) untreated with any material before bonding procedure took place. all the groups were subjected to polishing of teeth with rubber cup and non-fluoridated pumice, sprayed with water and then dried with oil-free compressed air stream, and then teeth were etched (35% phosphoric acid gel, 30 sec washed with water and dried by air blowing).(10) bonding procedure was done for all groups by the same type of adhesive and bracket. finally at the end of orthodontic treatment deboning procedure was done using bracket removing pliers, while the remaining adhesive was removed with help of 12 fluted tungsten carbide bur (komet gebr, brasseler, lamgo, germany) with low speed under water cooling. then finishing was conducted with extra fine sof-lex polishing discs (3m fspe dental product, 3mcenter) until achieving the luster of the enamel. new burs and discs were used for every subject in this study.(15) all the processes of adhesive removal and finishing were achieved with naked eye to simulate the clinical environment(19). then another color measurement for the upper six interior teeth in the same method, operator and device under the same circumstances were recorded as post-operative measurements. the color difference ∆ e between the first color measurement before bonding of the all groups and the second color measurement after debonding was calculated by the following equation: ∆ e = [ ( l1 –l2 ) 2 + (a1 – a2 )2 + (b1-b2) 2 ] ½ group number material manufacturer composition application 1 18 none 2 18 icon infiltrant dmg (hamburg germany) 1-icon –etch hydrochloric acid salicylic pyrogenic acid 2-icon dry 99% ethanol 3-icon infiltrant resin matrix based on methacrylates, primer and additives. 1the etch applied for 120 sec. 2applied for 30 sec with air drying. 3-applied for 180 sec reapplied for 60 sec then cured for 40 sec. 3 18 clinpro xt varnish 3m unitk (landsberg germany) silanized glass powder, silica treated with silicon methacrylate, 2-hydroxy ethil water, bis – gma. copolymer of acrylic acid and itaconic. 35% phosphoric acid for 20 sec then washing and air drying, mixing the components application and cured for 20 sec. j bagh college dentistry vol. 32(2), june 2020 evaluation of dental 19 where ∆ e represents color difference or change, while l1 represents the mean of the l value for each specific third, for example counting l1 for gingival thirds of upper anterior teeth according to following equation. (20) 𝐿1 𝑜𝑓 𝑔𝑖𝑛𝑔𝑖𝑣𝑎𝑙 𝑡ℎ𝑖𝑟𝑑 𝑜𝑓 𝑡ℎ𝑒 𝑢𝑝𝑝𝑒𝑟 𝑡𝑒𝑒𝑡ℎ = 𝑠𝑢𝑚 𝑜𝑓 𝐿 𝑣𝑎𝑙𝑢𝑒 𝑓𝑜𝑟 𝑡ℎ𝑒 𝑔𝑖𝑛𝑔𝑖𝑣𝑎𝑙 𝑡ℎ𝑖𝑟𝑑 𝑜𝑓 𝑎𝑙𝑙 𝑢𝑝𝑝𝑒𝑟 𝑎𝑛𝑡𝑒𝑟𝑖𝑜𝑟 𝑡𝑒𝑒𝑡ℎ 𝑏𝑒𝑓𝑜𝑟 𝑏𝑜𝑛𝑑𝑖𝑛𝑔 𝑁𝑜 𝑜𝑓 𝑢𝑝𝑝𝑒𝑟 𝑎𝑛𝑡𝑒𝑟𝑖𝑜𝑟 𝑡𝑒𝑒𝑡ℎ in the same procedure we can count a1 and b1 for the gingival third according to the upper equation, so we will deal with gingival thirds of upper teeth as one segment by calculating the average of the l, a and b; the same thing will apply for the middle thirds so each third either gingival for middle will have one average of the l1, a1 and b1. (3,20) descriptive statistics included means and standard deviation for both male and female subgroups in the three major groups, also independent sample ttest was used to find any gender difference within each group. one-way anova test was applied to compare ∆e in 3 groups included in this study for the gingival thirds and the middle thirds. again independent sample t-test to compare the ∆e between gingival thirds and middle thirds in each group. results table 2 shows means, standard deviation of the ∆e for the each gender subgroup in the main three groups included in this study. the t-test showed no significant difference between the male and female subgroups at a level of significance p < 0.05, so it is wise to pool the data of both gender subgroups in all three main groups in the present study. also, table 2 shows the mean of the ∆e in the middle thirds is higher than that of the gingival thirds, the difference was highly significant, p <0.001 as in table 5. table 3 and 4 show the difference in color change ∆e between the main three groups either for the gingival or the middle thirds, anova showed no significant difference between these three groups. table 2: descriptive statistics and gender difference for the ∆e within each group. group region males n=9 females n=9 t test d.f.=16 mean s.d mean s.d p value first gingival 3.93 0.91 4.01 1 0.164 (ns) middle 4.35 0.88 4.42 0.85 0.79 (ns) second gingival 3.89 0.6 3.77 0.94 0.69(ns) middle 4.22 0.79 4.11 0.66 0.74(ns) third gingival 4.51 0.91 4.37 0.77 0.81(ns) middle 5.1 0.49 4.99 0.95 0.84(ns) table 3: anova test to detect the difference in ∆e between the three groups included in this study for the gingival thirds. groups number mean sd first group 18 3.97 0.95 second group 18 3.83 0.77 third group 18 4.44 0.84 f test=2.67; p value=0.087, d.f.=53 (ns) table 4: anova test to detect the difference in ∆e between the 3 groups included in this study for the middle third. groups number mean sd first group 18 4.38 0.86 second group 18 4.16 0.72 third group 18 5.04 0.72 f test=4.052; p value=0.27, d.f.=53 (ns) table 5: independent sample t-test to compare the value of ∆e difference between middle and gingival third for the three groups included in this study. groups number t-test p-value first group 18 4.996 0.001 second group 18 3.331 0.001 third group 18 5.023 0.001 discussion in the present study we tried to explore the enamel color changes due to the use of recent prophylactic protector agents like the icon infiltrant and the clinpro xt varnish, to get rid of the possible clinical problem white spot lesion (wsl) that develops shortly after the fixed braces treatment. to be more specific, the labial aspects of the upper anterior teeth have been divided into 3 thirds: gingival, middle and incisal (the incisal thirds were omitted in this study because these protectors are indicated to be used only in peribracket area and the wsls are unlikely to develop in the incisal region since it is regarded as selfcleanable area. (1,2,21,22) the majority of the previous studies included the effect of the above materials on enamel color were in vitro studies, but we do not know how far these materials will affect the enamel color in clinical trials. table 2 shows a strong similarity between the ∆e of the control group and the 2nd icon infiltrant group, whereas table 3 and 4 show no significant difference between them. this result disagreed with matteo et al.(22) who exposed the extracted and icon infiltrant treated teeth to red wine and coffee, also our results disagreed with andero et al.(23) who induced the wsls for the extracted teeth and then treated them with icon infiltrant then exposed the treated teeth to red wine and j bagh college dentistry vol. 32(2), june 2020 evaluation of dental 20 coffee; the above two disagreements are due to difference in methodology since these previous studies are vitro while the present study is a vivo study. also in the present study we did polishing with pumice before the bonding procedure took place, this polishing may remove the infiltrant layer. on the other hand the result of this study (concerning the icon infiltrant) agreed with soyeon bak et al.(24) who did wsls to the extracted teeth, then treated them with icon infiltrant resulting in restoring healthy enamel color. regarding the 3rd group clinpro varnish, the ∆e in this group is higher than the control and 2nd icon infiltrant group (table 2) although the difference is not significant either in gingival or middle thirds (table 3, 4). this result agreed with nicoleta et al.(25) who did assessment for the surface discoloration of the enamel after application of the clinpro and after exposure to artificial aging and staining solutions, they found no significant difference in color stability. again nicoleta et al. (26) did another study to evaluate the effect of clinpro on bleaching power for natural teeth, so they took natural teeth as substrate, half of them were sealed with clinpro varnish and the other act as control, then they used office bleaching for both groups and did color measurement before and after the bleaching procedure they found that there was no significant difference between the 2 groups, according to the above both of the icon infiltrant and clinpro varnish had no significant difference on the enamel’s color if they were used prior to bonding of the fixed braces, in spite of the clinpro varnish group showing higher ∆e than both the control and icon infiltrant, but the difference is not significant, and the dental enamel behaves in similar ways with both protector materials. so according to the results of the present study, the 1st and 2nd hypotheses were rejected since both materials showed no effect on enamel color and the latter behaved the same with both of them in spite of their differences. regarding the regional differences in ∆e, the value of the ∆e in middle third of all three groups is significantly greater than that of the gingival thirds, this result agreed with allabban(20), the darker color of the middle thirds may be due to the presence of the bracket in the middle third so the bracket acts as a protector for the middle third from the abrasion of teeth brushing, on the other hand the gingival thirds are subject to the abrasion of teeth cleaning and this abrasion is enough to remove the infiltrated enamel layer with protecting and/or bonding agent and exposing new fresh enamel layer, because the infiltrated enamel with any materials, all the time looks darker than virgin enamel surface due to infiltrated resin tags that absorb water and stains from the oral environment. conclusion 1both the icon infiltrant and clinpro varnish have no adverse effects on enamel color when used before the bonding of fixed braces as protecting agents against wsls. 2the gingival thirds show less color change after fixed orthodontic treatment whether we use protector agents or not. conflict of interest: none. references 1. al-jaibehji m. the influence of caries infitrant combined with and without conventional adhesives on sealing of the sound enamel (in vitro study). a thesis submitted to the college of dentistry, university of baghdad, 2014; 14-15. 2. moreira tc, sampaio rkl. efeitor do tratamento ortodontico sobre o esmalto desmineralizacaoi e pigmentacao. rev dental prss ortod ortop facial 2001 mar-apr; 6(2): 41-8 3. freit ao, marquezan m, nojma mc, alviano ds, maia lc. the influence of orthodontic fixed appliance on the oral microbiota: a systematic review. dental press j orthod. 2014;19(2):46-55. 4. souza de-silva cm, parisotto tm, steiner-oliveira c, kamiya ru, rodrigues lk, nobre-dososantos m. carbon dioxide laser and bonding material reduce enamel demineralization around orthodontic bracket. lasers med sci. 2013;28(1):111-8. 5. benson pe, shah aa, millett dt, dyer f, parken n, vine rs. fluorides, orthodontics and demineralization: a systematic review. j orthod. 2005;32(2):102-14. 6. benson jg, van der veen mh, lagerweij md, bokhout b, prahl-andersen b. canes prevalence measured with qlf after treatment with fixed orthodontic appliances; influence factor. caries res. 2005;39(1):41-7. 7. ahn sj, lim bs, lee yk, nahm ds. quantitative determination of adhesion patterns of cariogenic streptococci to various orthodontic adhesives. angle orthod. 2006; 76(5):869-75. 8. kerbusch ae, kuijoers-jagtman am, mulder j, van der sanden wj. prevention of white spots during orthodontic treatment with fixed appliance. ned tijdschr tandheelkd. 2010;117(5):283-7. 9. shungin dolsson al, persson m. orthodontic treatment –related white spot lesions. a 14 year prospective quantitative follow-up including bonding material assessment am j orthod dentofacial orthop. 2010;138(2):136-7. 10. vianna julia sotero, marquezan mariana, lau thiago chon leon, sant anna eduardo franzotti. bonding brackets on white spot lesions pretreated by means of two methods. dental press j orthod. 2016; 21(2):3944. 11. chang hs, walsh lj, freer tj. enamel demineralization during orthodontic treatment. j bagh college dentistry vol. 32(2), june 2020 evaluation of dental 21 aetiology and prevention, aust dental j. 1997; 42:(5):322-7. 12. isiksal e, hazar s, akyalcin s. smile esthetics: perception and comparison of treated and untreated smile. am j orthod dentofacial orthop. 2006;129: 816. 13. al-maaitah ef, abo omar aa, al-kateeb sn. effect of fixed orthodontic appliance bonded with different etching techniques on tooth color: a prospective clinical study. am j orthod dentofacial orthop. 2013; 144: 43-9. 14. hibemon lf, maia leg, marcus va. influence of the esthetic bracket (color, translucence, and fluorescence) on visual perception. am j orthod dentofacial orthop. 2012;141:460-7. 15. allabban yr. comparison of enamel color alteration between bonded and free unbonded surface of maxillary anterior teeth after fixed orthodontic therapy (a prospective clinical study). j baghdad coll dent. 2015;27(3):174-78. 16. judeh a, al-wahadni a. a comparison between conventional visual and spectrophotometric for shade selection. quitessence int. 2009;40:e69-79. 17. brewer jd, wee a, seghi r. advance in color matching. dent clin north am. 2004; 48:341-58. 18. rakyali g, ozdemir fi, arun t. enamel color changes at debonding and after finishing procedure using five different adhesives. eur j orthod. 2009; 31: 397401. 19. zaher ar, abdalla em, abdel moti ma, rehman. changes after debonding using various bonding systems. j orthod. 2012;39:82-8. 20. allabban yr. response of dental enamel to office external bleaching following fixed orthodontic treatment using two types of orthodontic adhesives (clinical prospective study). ijsr. 2017; 6(4): 16381642. 21. rengin a, bongna s, defne k, michael k, drik w, thomas a. shear bond strength of brackets to demineralize enamel after different pretreatment methods. angle orthod. 2012;82(1):56-61. 22. matteo c, davide r, matteo v, ricardo b, marco c, marco co, claudio p. resin infiltrant for non– cavitated caries lesions: evaluation of color stability. j clin exp dent. 2017;9(2):e231-7. 23. andrew l, sercan a, jeryl d, eser t, rade p. evaluation of staining and color changes of a resin infiltration system. angle orthod. 2016;86 (6):900-4. 24. so-yeon b, young-jae k, hong-keun hyun. color change of white spot lesions after resin infiltration. color res app. 2014; 39(5):506-10. 25. nicoleta c, alexander j. hassel. effect of staining and polishing on different types of enamel surface sealant. j esth rest dent. 2018; 30(4). 26. nicoleta c, hassel aj, sinan s, zingler s. effect of enamel sealant on tooth bleaching and on the color stability of the result. odontology. 2016;105(2):31-9. الخالصة وهي ايكون المتغلغل و كلنبرو فارنيش الحمايةهو تقييم التغير اللوني لميناء السن بعد معاملته بنوعين من مواد الدراسةالهدف من هذه لمنع حدوث البقع البيضاء بعد عالج تقويم االسنان الثابت بكل والثالثة الثانيةشخص بحاجه الى تقويم اسنان ثابت، انقسموا على ثالث مجاميع االولى ضابطه وتم معالجه 54والمواد: الطريقة معايير اللون )ل ا ب( اخذت قبل و بعد العالج ‘ التقويميةبل تثبيت الحواصر من ايكون المتغلل وكلنبرو فارنيش على الترتيب ق .الثالثةلميناء السن بين المجاميع e∆لم يوجد فرق مهم في التغير اللوني : النتائج استخدما قبل جهاز التقويم االستنتاجات: كل من ايكون المتغلل وكلنبرو فارنيش ال يوثران على لون ميناء السن بطريق سلبيه اذا ما الثابت. 404 not found not found the requested url /files/6.pdf was not found on this server. 23. harraa f.doc j bagh college dentistry vol. 25(1), march 2013 the effect of thermocycling orthodontics, pedodontics and preventive dentistry139 the effect of thermocycling and debonding time on the shear bond strength of different orthodontic brackets bonded with light-emitting diode adhesive (in vitro study) harraa s. mohammed-salih, b.d.s., m.sc. (1) abstract background: thermocycling simulates the temperature dynamics in the oral environment. this in vitro study done to measure and compare the effect of thermocycling on the shear bond strength of stainless steel and sapphire brackets bonded to human enamel teeth using light cured orthodontic adhesive and debonded at various time, and to measure adhesive remnant index after debonding. materials and methods: one-hundred-twenty extracted upper first premolars for orthodontic reason were used in this study; depending on weather thermocycled or not, the sample was divided into two main groups, then within each group 30 teeth were used for stainless-steel brackets (bionic®) and for sapphire brackets (pure®). both groups were subdivided into three groups (n = 10) according to the debond times: i: debond after 24 hour, ii: debond after 7 days and iii: debond after 30 days. within 24 hr, half of the sample was thermocycled manually for 500 complete cycles between 5/55°c and the remaining sample was stored in distilled water at room temperature and water was changed daily until debond time for each group was performed. the adhesive remnant index was tested under 20x magnification lens using stereomicroscope. results and conclusions: both bracket types demonstrated high shear bond strength values before thermocycling (p≤0.05), whereas after 500 thermocycles, there were significant changes in shear bond strength resulted in marked reduction in the stainless steel brackets than in the sapphire brackets (p≤0.05). shear bond strength values increased with time for both stainless steel and sapphire brackets with and without thermocycling (p≤0.05). the tendency of bond failure was increased at the bracket/adhesive interface rather than enamel/bracket interface in the stainless steel brackets whereas at the enamel/bracket interface rather than bracket/adhesive interface in the sapphire brackets. keywords: shear bond strength, thermocycling, debond time, sapphire, stainless steel. (j bagh coll dentistry 2013; 25(1):139-145). introduction in orthodontic practice, it is essential to obtain reliable adhesive bonds between orthodontic brackets and tooth enamel (1). shear bond strength (sbs) should not only be high enough to resist the forces during the course of orthodontic treatment but also low enough to allow the removal of the bracket without any complications at the end of orthodontic treatment (2). because of the fact that orthodontic adhesives are routinely exposed to thermal changes in the oral cavity, it is paramount to establish whether these changes introduce stress in the adhesive that might affect bond strength. thus, any new adhesive should be tested both at 24 hours of storage in water and after thermal cycling (3). thermal cycling is the in vitro process through which the adhesive resin and the tooth are subjected to temperature extremes compatible with the oral cavity (4).gale and darvell (5) pointed to the absence of agreement and standardization between the various thermocycling studies. different thermocycling regimens were used in the in vitro studies (1, 69). the main difference among these studies was in the number of thermal cycles (500, 750, 1500, 2500, 6000 and 10000). (1) assistant lecturer. department of orthodontics. college of dentistry. university of baghdad. at the same time, the temperature extremes were different. the low-temperature points were 5°c or 10°c, and the high-temperature points were 45°c, 50°c, or 55°c. nevertheless, in these studies the thermocycled samples were not compared with non-thermocycled samples as recommended by bishara et al. (3) who have suggested that thermal cycling should be part of the testing protocol of any new adhesives. such large variations between the thermocycling protocols led the international organization for standardization (iso/tr 11405: 1994) to provide specific criteria for conducting such tests to enable investigators and industry to interpret and compare results (10), which indicates that a thermocycling regimen comprising 500 cycles in water between 5 and 55°c is an appropriate artificial ageing test, and many studies have been carried out following the iso standard. many studies in orthodontics have used various number of thermocycles: approximately 1500 cycles between 10 and 50°c after 3 months of storage (8), 500 cycles between 5 and 55°c (6), 6000 cycles between 5 and 55°c (11), and 10,000 cycles between 5 and 55°c (9), such studies conclude no greater differences in the sbs after increasing thermal cycling. most research into dental composite bond strength is in vitro because it is difficult to expose the materials to and retrieve them from the oral environment without j bagh college dentistry vol. 25(1), march 2013 the effect of thermocycling orthodontics, pedodontics and preventive dentistry140 interfering with the environment itself or taxing the subjects’ compliance (12). traditionally, orthodontic bonding systems are evaluated by invitro sbs tests with a universal testing machine which considered the standard for assessing bond strength in vitro (13). therefore; thermocycling is essential to simulate the temperature dynamics in the oral environment of in vitro studies. with direct bonding adhesives; thermocycling reduces the bond strength of orthodontic adhesives (14). orthodontic brackets may be composed of several materials, such as stainless steel, polymers, porcelain, titanium or their combination. as the number of adults seeking orthodontic care has increased, orthodontists have felt the need to provide their patients with more esthetically appealing appliances. this perceived need has motivated manufacturers to design various types of esthetic brackets, including sapphire brackets. sapphire (pure®) brackets designed to be one of the esthetic bracket systems, made from high quality monocrystalline sapphire with zirconia spheres to provide superior sbs and predictable debonding (15). however, only a few studies have investigated modifications in the bonding technique, even for metallic or sapphire brackets. in clinical orthodontic practice, there is no consensus about the minimum time required before loading the bracket (16). testing at 24 hr is generally preferred because it has been widely reported, and allows comparison with other in vitro bond strength studies (17). furthermore, polymerization is expected to be complete at the end of 24 hr (18). however, this time period of 24 hr does not reflect clinical orthodontic practice, in which the archwire is usually placed after bracket bonding (19, 20). on the other hand, bracketbonding failures sometimes occur during different stages of treatment due to heavy forces produced by an archwire, in addition, significant degradation of the adhesive and its bond to tooth enamel would have occurred over time in the relatively harsh oral environment and light-cured materials are subjected to thermal changes in the oral cavity. also there is a lack of studies in which these orthodontic brackets (sapphire, pure®) are subjected to thermocycling. therefore; the aim of this study was to compare the sbs of sapphire (pure®) and stainless-steel brackets cured with light-emitting diode (led) under thermocycling at different debond times ( 24 hr, 7days, and 30 days) as well as to evaluate the enamel conditions after the debonding, through adhesive remnant index (ari). materials and methods teeth a total of one-hundred-fifty upper first premolar teeth were collected, which have been extracted from 12-18 years old iraqi patients seeking orthodontic treatment. after extraction, the teeth were washed by water to remove any traces of blood. then each tooth was thoroughly scaled and rinsed to remove calculus, soft tissue remnants, and debris. the collected teeth were stored in fresh distilled water containing crystals of thymol and changed weekly to prevent dehydration and bacterial growth in closed container at room temperature until preparation and testing. one-hundred-twenty teeth were selected after examining with no decay, restorations, or infections. also teeth pretreated with chemical agents, such as hydrogen peroxide were excluded. brackets and groups tested the selected one-hundred-twenty teeth were randomly assigned into two main groups 60 teeth of each on the basis of thermocycled or without thermocycling, then within each group 30 teeth were used for stainless-steel brackets (bionic®) and the other for sapphire brackets (pure®). both groups were subdivided into three groups (n = 10) according to the debond times: group (i): debond after 24 hr. group (ii): debond after 7 days. group (iii): debond after 30 days. the base surface area of the bionic® and pure® brackets were: 10.9 mm2 and 11.9 mm2 respectively, as provided by the company (ortho technology company, usa). bonding to exclude the possible differences in bond strength caused by the orthodontic adhesive, all brackets were bonded with the same material (light–cured orthodontic adhesive, resilience®, ortho technology company, usa). all the teeth were mounted, retentive wedge shaped cuts were made along the sides of the roots of each tooth to increase the retention of the teeth inside the self-cured acrylic blocks. each tooth was then fitted on a glass slab in a vertical position using soft sticky wax at the root apex, in a way that the middle third of the buccal surface was oriented to be parallel to the analyzing rod of the surveyor, so that the force could be applied at right angle to the enamel-bracket interface because sbs measurements were significantly influenced by the direction of the debonding force. two other teeth were fixed following the above mentioned procedure with 1cm apart j bagh college dentistry vol. 25(1), march 2013 the effect of thermocycling orthodontics, pedodontics and preventive dentistry141 between them on the same glass slab. the occlusal surfaces of the three teeth were oriented to same height by cutting from the root apices using a stone disc bur. then two l-shaped metal plates, were painted with a thin layer of separating medium (vaseline) and placed opposite to each other to form a box around the teeth. powder and liquid of self-cured acrylic were mixed and poured around the teeth to the level of the cemento-enamel junction of each tooth. after setting of the cold-cured acrylic resin, the two lshaped metal plates were removed, the sticky wax used for fixation of teeth in the proper orientation removed too and the resulting holes filled with cold-cured acrylic (21). the mounted teeth were stored in distilled water containing thymol crystal to prevent dehydration until bonding. the buccal surface of each tooth polished with slurry non-fluoridated pumice for 10 seconds, then washed with water spray for 10 seconds, and dried with oil-free air for 10 seconds. phosphoric acid gel was applied for 15 seconds, washed with air water spray for 20 seconds, and then dried with oil-free air for another 20 seconds, until the buccal surface of the etched tooth appeared chalky white in color. a load of about 200g was attached to the vertical arm of the surveyor to standardize the pressure applied on the brackets during bonding (22, 23). the bonding agents were handled according to manufacturer's instruction. each bracket was placed at the center of the buccal surface, the load was applied for 10 seconds (23), and any excess material was removed with sharp explorer. the light source was of high powered light emitting diode (led type) cordless curing light with the wavelength range for polymerization of: 440-480 nm (radii plus, southern dental industries (sdi), australia) that was applied mesially and distally for 20 seconds (10 seconds for each) with a minimum separation distance (1-2) mm. every tooth was left undisturbed for 30 minutes to ensure complete polymerization of adhesive material; the specimens were stored in distilled water at 37±2°c. thermocycling procedure within 24hr, half of the sample (60 teeth) was thermocycled between 5°c and 55°c for 500 complete cycles. the thermocycling was done manually following the recommendation of the iso/ts 11405, the exposure to each bath was 30 seconds, and the transfer time between the two baths was 5-10 seconds (9). the remaining sample was stored in distilled water at room temperature and water was changed daily until debond time for each group was performed. debonding procedure debonding was performed using an instron universal testing machine with a crosshead speed of 0.5mm/minute (21) at room temperature for each group according to the different debonded-time intervals (after 24 hr, 7 days and 30 days). the samples were tested for bond strength; the readings were recorded in newtons (n). the force was divided by the surface area of the bracket base to obtain the stress value in mega pascal units (mpa), with the following equation: shear force (mpa) = debonding force (n)/ surface area of bracket base (mm2), so that 1mpa=1n/mm2. residual adhesive after debonding, the enamel surface of each tooth and the bracket bases were examined with a stereomicroscope (magnification 20x) by one investigator to determine the amount of residual adhesive remaining on each tooth. the adhesive remnant index (ari) was used to assess the amount of adhesive left on the enamel surfaces (24). this scale ranges from 0 to 3, following the scores defined as follows: 0 = no adhesive left on the tooth; 1 = less than half of the adhesive left on the tooth; 2 = more than half of the adhesive left on the tooth; 3 = adhesive totally left on the tooth with a distinct impression of the bracket mesh. statistical analysis the results were expressed by measuring sbs means in each group in mpa and the data collected were analyzed using spss software version 15 (2006). statistical analyses were performed including means, standard deviation and standard errors of the mean for each group. one-way analysis of variance (anova) with f test was used for multiple comparisons between the three time intervals for debonding of each bracket type (stainless steel and sapphire) and independent sample ttest was used to compare differences between the bracket types with and without thermocycling at each debond time. a value of p≤0.05 was considered significant. results descriptive statistics including means, standard deviation and standard errors of the sbs at three time intervals (time i = after 24 hr, time ii= after 7 days, time iii = after 30 days) with and without thermocycling using stainless steel and sapphire brackets are shown in table (1). the mean sbs is higher with sapphire brackets than j bagh college dentistry vol. 25(1), march 2013 the effect of thermocycling orthodontics, pedodontics and preventive dentistry142 that with stainless steel brackets at three debonding time with and without thermocycling. • without thermocycling: anova test showed a high significant difference among three debonding time with stainless steel bracket and non-significant difference with sapphire brackets. whereas, with thermocycling this difference is highly significant with both stainless steel and sapphire brackets. lsd (least significant difference test) done to compare between each two debonding time of stainless steel brackets, showed that the difference in the sbs is highly significant between time i with time ii and iii but insignificant between time ii and iii. • with thermocycling: anova test showed a high significant difference in the sbs among the three debonding time with both types of bracket used. lsd test showed a high significant difference in the sbs between times i with iii and between time ii with iii, but non-significant difference between time i and ii with both stainless steel and sapphire brackets. table (2) and fig (1and2) showed that the sbs with sapphire bracket is significantly higher than that with stainless steel brackets at three debonding time with and without thermocycling, except that, this increment is non-significant after 30 days in group without thermocycling. moreover, a high significant reduction in the sbs was noticed after thermocycling at both time i and ii and this reduction is non-significant at time iii with both stainless steel and sapphire brackets table (3) and fig (3and 4). the ari frequency was shown in table (4), score 0 seen with both types of brackets. with stainless steel brackets it was seen more without thermocycling, whereas with sapphire bracket it was seen more after thermocycling. score 1 seen with both types of brackets. with stainless steel brackets it was seen more after thermocycling whereas with sapphire brackets it was seen more without thermocycling. score 2 seen more with sapphire brackets than stainless steel brackets and score 3 seen only with stainless steel brackets only. discussion during function, orthodontic brackets are subjected to either shear, tensile or torsion forces, or even a combination of these factors. in the present study the mean sbs in all groups was exceeding the minimal limits suggested by reynolds (25) which is 5.9 – 8.7 mpa to be adequate for most clinical orthodontic needs with much higher values with sapphire brackets in comparison with stainless steel brackets, this could be related to the translucency of sapphire brackets which allow more chance for the light to pass through resulting in a more complete polymerization in comparison to stainless steel brackets. a marked reduction in the sbs was noticed after thermocycling and this could be attributed to the differences in the coefficient of thermal expansion between the adhesive, brackets and enamel which in turn could adversely affect the adhesion of the resin to the bracket and tooth (26). also the cyclical stress of thermocycling at two different temperature extremes could also cause any weakened areas within the bond to grow progressively in size (27) .this marked reduction in the sbs following thermocycling was noticed in the stainless steel brackets than in the sapphire brackets, which could be attributed to the base design of sapphire bracket compared to stainless steel brackets which allowed for a better retention of the adhesive to the base. the presence of zirconia particles coating the bracket base creates millions of undercuts that secure the bracket in place, due to the micro mechanical retention means. therefore; in the clinical orthodontic practice, with metallic brackets the clinician must consider the critical question of whether the bond is strong enough to withstand forces applied during orthodontic treatment, while with sapphire brackets, the concern is whether the bond is weak enough for safe debonding (28). with regard to relationship between debonding time and the sbs values, the present study evaluated three different debonding times, 24 hr, 1 week and 1 month. the results demonstrated the highest sbs with stainless steel brackets was noticed after 1 month, with and without thermocycling, and this agree with findings of al-arar, (29) who used three debonding time 24hr, 1month and 3 months revealed that the maximum sbs was achieved after 1 month and reduced after 3 months., and disagree with the findings of hajrassie and khier, (30) who evaluated periods of 10 min, 24 hr, 1 week and 4 weeks after bonding and concluded that sbs values using orthodontic adhesives to metallic brackets increase with the debond time, but no statistically significant difference was reported for both the in vivo and in vitro data. however, the highest sbs with sapphire brackets was observed after 1 week without thermocycling and after 1 month with thermocycling, this mean that the effect of thermocycling in the reduction of sbs was increased with time in sapphire brackets this could be attributed to increased water absorption or solubility of the composite, or both. in terms of j bagh college dentistry vol. 25(1), march 2013 the effect of thermocycling orthodontics, pedodontics and preventive dentistry143 composite resin, the principal interaction occurs with water, which diffuses into the matrix causing hygroscopic expansion of the material as well as a chemical degradation of the material (31). moreover, sbs studies have shown a decrease in bond strength of orthodontic composites after immersion in water, the longer the composite is immersed, the lower the bond strength and the greater the degradation of the composite resin (32). concerning the site of bond failure, with stainless steel brackets less ari score was seen with higher sbs value in both with and without thermocycling, this mean that the high sbs value comes from more retention of adhesive to bracket base rather than enamel surface. whereas with sapphire brackets ari score reduced with thermocycling, this mean that the effect of thermocycling occur more on the enamel bracket interface rather than bracket adhesive interface and this may be related to the retention mean on the base of sapphire brackets which is coated with zirconia powder that increase the retention mean on bracket base. as a conclusion, thermocycling is the best process to mimic the thermal changes in the oral environment of in vitro studies, resulted in a significant reduction in the sbs. this marked reduction was noticed in the stainless steel brackets than in the sapphire brackets; eventhough, sbs of sapphire brackets is greater than that of stainless steel brackets without thermocycling. when evaluating bond strength studies, it is important to be aware of the stresses that the intraoral environment induces with time. with regard to relationship between debonding time and the sbs values, the sbs values were increased with time for both stainless steel and sapphire brackets with and without thermocycling. references 1grubisa hs, heo g, raboud d, glover ke, major pw. an evaluation and comparison of orthodontic bracket bond strengths achieved with self-etching primer. am j orthod dentofacial orthop 2004; 126: 213–9. 2gasgoos ss, sa’id rj. the effect of thermocycling on shear bond strength of two types of self– etch primers. al–rafidain dent j 2009; 9(2): 246–53. 3bishara se, ajlouni r, laffoon jf. effect of thermocycling on the shear bond strength of a cyanoacrylate orthodontic adhesive. am j orthod dentofacial orthop 2003; 123: 21–4. 4helvatjoglu-antoniades m, koliniotou-kubia e, dionyssopoulos p. the effect of thermal cycling on the bovine dentine shear bond strength of current adhesive systems. j oral rehabil 2004; 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(ivsl). table 1: sbs (mpa) of stainless steel and sapphire brackets bonded using orthodontic adhesive with and without thermocycling at three debonding time. table 2: bracket difference in the sbs (mpa) with and without thermocycling at three debonding time. ns: non-significant p> 0.05, *: significant 0.05≥p>0.01, **: highly significant 0.01≥p>0.001. table 3: comparison of the sbs with and without thermocycling using stainless steel and sapphire brackets at three debonding time brackets stainless steel sapphire conditions without thermocycling with thermocycling differences without thermocycling with thermocycling difference debonding time mean s.d. mean s.d. t-test p-value mean s.d. mean s.d. ttest p-value i 12.17 0.99 7.80 0.96 7.77 0.000** 32.74 3.65 18.52 1.10 9.15 0.000** ii 25.56 2.49 6.52 0.83 17.76 0.000** 38.20 3.69 21.42 2.10 9.68 0.000** iii 28.64 4.12 25.73 2.41 1.49 0.17 ns 33.42 7.58 32.06 4.62 0.38 0.71 ns ns: non-significant p> 0.05, *: significant 0.05≥p>0.01, **: highly significant 0.01≥p>0.001. conditions brackets debonding time descriptive statistics differences anova test lsd test mean s.d. s.e. f-test p-value i-ii i-iii ii-iii without thermocycling stainless steel i 12.17 0.99 0.40 57.16 ns 0.000 ** 0.000 ** 0.000 ** 0.08 ns ii 25.56 2.49 1.02 iii 28.64 4.12 1.68 sapphire i 32.74 3.65 1.49 1.89 ns 0.19 ns ii 38.20 3.69 1.51 iii 33.42 7.58 3.09 with thermocycling stainless steel i 7.80 0.96 0.39 279.71 ns 0.000 ** 0.18 ns 0.000 ** 0.000 ** ii 6.52 0.83 0.34 iii 25.73 2.41 0.98 sapphire i 18.52 1.10 0.45 33.83 ns 0.000 ** 0.12 ns 0.000 ** 0.000 ** ii 21.42 2.10 0.86 iii 32.06 4.62 1.89 conditions without thermocycling with thermocycling brackets stainless steel sapphire differences stainless steel sapphire differences debonding time mean s.d. mean s.d. t-test p-value mean s.d. mean s.d. t-test p-value i 12.17 0.99 32.74 3.65 -13.34 0.000** 7.80 0.96 18.52 1.10 17.93 0.000** ii 25.56 2.49 38.20 3.69 -6.96 0.000** 6.52 0.83 21.42 2.10 -16.15 0.000** iii 28.64 4.12 33.42 7.58 -1.36 0.2 ns 25.73 2.41 32.06 4.62 -2.97 0.014** j bagh college dentistry vol. 25(1), march 2013 the effect of thermocycling orthodontics, pedodontics and preventive dentistry145 table 4: ari scores for stainless steel and sapphire brackets with and without thermocycling at three debonding time. with thermocycling without thermocycling conditions sapphire stainless steel sapphire stainless steel brackets iii ii i iii ii i iii ii i iii ii i score 5 7 10 4 0 2 5 3 2 6 7 0 0 5 0 0 6 4 2 5 0 8 4 3 0 1 0 3 0 0 0 0 0 7 0 0 0 5 2 figure 1: adhesive sbs with thermocycling using stainless steel and sapphire brackets at three debonding time. figure 2: adhesive sbs without thermocycling using stainless steel and sapphire brackets at three debonding time. figure 3: adhesive sbs with and without thermocycling using stainless steel brackets at three debonding time. figure 4: adhesive sbs with and without thermocycling using sapphire brackets at three debonding time. suzan f.doc j bagh college dentistry vol. 27(3), september 2015 measurement of salivary oral and maxillofacial surgery and periodontics 120 measurement of salivary immunoglobulin a of participants with a healthy, gingivitis and chronic periodontitis conditions suzan ali salman, b.d.s., m.sc. (1) abstract background: secretory immunoglobulin a (siga) is a subclass of immunoglobulin a (iga), it is an antibody that plays an important role in mucosal immunity. it is the main immunoglobulin found in mucous secretions from mammary glands, tear glands and salivary glands, every pathologic process in the body involves the immune system, and periodontal inflammation is one of them and is not an exception. material and methods: this study was consisted of 60 healthy male participants of an age ranged between (35-50) years old ; 25 of them with generalized moderate chronic periodontists(clinical attachment loss equal to 3-4mm at ≥ 30% of the sites; 20 participants with plaque induced gingivitis and 15 participants had clinically healthy periodontium as control group. oral examination include plaque index, gingival index, probing pocket depth and clinical attachment level were conducted for all participants four sites were examined for each tooth (labial ,lingual, mesial and distal), 2ml of unstimulated whole saliva was collected from all participants to measure secretory immunoglobulin a in µg /ml by enzyme-linked immunosorbent assay technique. results: salivary iga(siga) mean was (356.3) µg /ml for the chronic periodontitis patients; while it was 202 µg /ml for plaque induced gingivitis patients and it was 129.2 µg /ml for the control group. highly significant differences among the three group were recorded (p-value <0.001). for chronic periodontitis patients, the plaque index gingival index scores were positively highly significant correlated with secretory immunoglobulin a level in saliva. the probing pocket depth scores were positively and significantly associated with secretory immunoglobulin a level. the clinical attachment level scores were positively but non significant associated with secretory immunoglobulin a level. for the gingivitis and the control group they were positive non significant association between the periodontal parameters and the secretory immunoglobulin a level in saliva. conclusion: there is a correlation between secretory immunoglobulin a level in saliva and the periodontal health status. keywords: siga, saliva, chronic periodontitis, gingivitis. (j bagh coll dentistry 2015; 27(3):120-123). introduction periodontal diseases (pd) are multi-factorial diseases that involved hard and soft dental tissues, bacterial colonization, and immune responses of the host. antibodies of the humoral immune responses have an important role in protection of the oral environment because of the ability of antibodies to prevent microbial attachment to cell surfaces and aggregation of microorganisms (1). specific antibody systems, including immunoglobulin a (iga), are found in saliva. saliva sample cannot give site specific information but it considered as a complex body fluid now a day used for early diagnosis and detection markers for potential vulnerability to several diseases including periodontal disease2,3 whole saliva analysis give us a simple and noninvasive method for evaluating the role of salivary iga (siga) levels in periodontal disease (4,5). periodontal inflammation like other pathologic process in the body involves the immune system. a wide number of microorganisms play an important role in periodontal disease. (1) lecturer, department of periodontics, college of dentistry, university of baghdad. they may cause destruction by 1. microbial metabolites that cause direct inflammatory responses; and 2. by antigen or oral microbes starting immunopathologic processes causing periodontal inflammation (6,7). salivary iga(siga) is considered as the first line of defense in the oral cavity against the invading microorganisms and it is shown to be a predominant immunoglobulin in external secretion against igg , which predominates in serum and internal secretion (8,9). this study was used unstimulated whole saliva for analysis of siga and search if there is a correlation between siga concentration and different periodontal parameters for patient with chronic periodontitis, plaque induced gingivitis and healthy control materials and methods study design this study was conducted in baghdad college in the department of periodontics. sixty adult males, with an age ranged between 35-50years old groups were involved. they should be healthy with no history of any systemic disease, nonsmoker not received any antibiotic therapy in the previous one month .patients suffering from systemic diseases and those with upper respiratory j bagh college dentistry vol. 27(3), september 2015 measurement of salivary oral and maxillofacial surgery and periodontics 121 diseases were excluded. samples were grouped as: 1. group 1(g1): 25 participants with generalized moderate chronic periodontitis (cal=3-4mm at ≥ 30%of the sites) (10) 2. group 2 (g2): 20 participants with plaque induced gingivitis 3. group 3(g3): 15 participants as the control group with no clinical sign of gingival or periodontal inflammation collection of saliva between the hours of 10-12a.m. and one hour after the last meals, two to three ml.s of unstimulated whole saliva was collected before the clinical periodontal examination. each participant was asked to rinse his mouth with water to remove any debris present. the first mouth full of saliva was discarded to ensure water clearance then they were asked to spit all the saliva in sterile test tube over a fifteen minutes period. the samples of saliva were centrifuged at 3000 r.p.m for 15 minutes to remove the debris and then the superior clear supernatant saliva kept frozen at -20 until biochemical assessment. salivary immunoglobulin a (siga) concentration was evaluated using enzyme linked immunosorbent assay (eliza) technique for the quantitative determination of secretory iga following the guide lines of the commercial kit provided by demeditec diagnostics gmbh.d24145kiel (germany). the eliza test was done in biochemistry department of blood bank in babalmuatham. data analyses were conducted by using of spss (version 15). clinical examination periodontal examination included plaque index (11), gingival index (12), probing pocket depth (ppd) (13) and clinical attachment level (cal) (14). results table (1) was shown mean and standard deviation of the periodontal parameters (pli, gi , ppd, cal) of chronic periodontitis , pli and gi for gingivitis and control groups. table 2 was shown mean and standard deviation of siga for the g1 it was (356µg/ml±103.9), for g2 it was (202 µg/ml ± 43.05) and g3 it was (129µg/ml ± 64.91). the f-test was used and showed highly significant differences among the three groups. table(3) showed inter group comparison for iga with significant differences using t-test highly significant differences were found between each pair of groups (p<0.001) table (4)showed the correlation between siga and the periodontal parameters of the three groups for g1 group pli and gi positively and highly significant correlation was found(+0.571),( +0.71) respectably, for ppd positive significant correlation was found (+0.450), while it was positive but non significant correlation for the cal(+0.104), for the other two groups there was positive but non significant correlation between siga and the periodontal parameters. table 1: mean and standard deviation for the periodontal parameters of the three groups variables chronic periodontitis gingivitis control mean sd mean sd mean sd pli 1.82 0.50 1.67 0.41 0.82 0.24 gi 1.99 0.37 1.77 0.38 0.66 0.34 ppd 5.10 0.98 cal 3.7 0.89 0 0 0 0 table 2: mean and standard deviation with significant differences for the siga of the three group using f-test siga µg/ml chronic periodontitis gingivitis control ftest p-value mean sd mean sd mean sd 44.01 0.000*** 356.3 103.9 202 43.05 129.2 64.91 *p value >0.05 non significant, ** p value <0.05 significant, *** p value <0.001 highly significant table 3: inter group comparison for iga level with significant differences using t –test groups ttest pvalue control & gingivitis 0.000165 <0.001*** control & chronic periodontitis 0.00063 <0.001*** gingivitis &chronic periodontitis 0.00051 <0.001*** j bagh college dentistry vol. 27(3), september 2015 measurement of salivary oral and maxillofacial surgery and periodontics 122 table 4: correlation coefficient between the periodontal parameters of the three groups and siga level (µg/ml) discussion siga considered as the main immunoglobulin isotype in body secretions including saliva and it is considered to be the principal line of defense of the host against pathogens (15). salivary iga prevents the mucosal penetration and considered as first line of defense. antibacterial activity of siga is due to its property of coating and agglutinating of microorganism. the agglutinating mechanism is explained by the fact that antibodies in the saliva will react with bacteria proliferating on surface and prevent their attachment (16). the present study was included healthy male only to avoid the alteration in salivary flow rate between male and female (17), we take unstimulated saliva because stimulation led to decrease in salivary iga concentration (18,19). patients selected for the study of an age ranged between 35-50 as challacombe et al (20) and miletic et al (21) those authors were found a significant reduction in the concentration and secretion rates of salivary iga in the elderly people. in the present study the level of siga in gingivitis and periodontitis patients were found to be highly significant when compared with the healthy controls group, this study was in agreement with many studies (16,22-25). the higher levels of siga in chronic periodontitis and gingivitis group due to production of iga from the immunocytes of salivary glands, gingival tissue, and from serum due to antigenic stimulation by periodontopathogenic bacteria. for g1 there is direct and strong relation between siga and pli scores and gi scores , for g2and g3 there were also a direct relation with siga level and it is easy to explained when there is more microbial plaque biofilm on the teeth mean more microbial toxin that cause direct gingival inflammation also more microbial antigen that illicit the immune system for production of more siga, butchibabu et al study (24) improved that the level of siga will decrease after phase 1 of periodontal treatment. we concluded the more severe the periodontal involvement the more level of s iga level as it is the first line of host defense. references 1. teng yt. protective and destructive immunity in the periodontium: part 1—innate and humoral immunity and the periodontium. j dent res 2006; 85(3):198208. 2. albandar jm, denardin am, adesanya mr, diehl sr, winn dm. associations between serum antibody levels to periodontal pathogens and early-onset periodontitis. j periodontol 2001; 72(11):1463-9. 3. streckfus cf, bigler lr. saliva as a diagnostic fluid. oral dis 2002; 8(2): 69-76. 4. lee yh, wong dt. saliva: an emerging biofluid for early detection of diseases. am j dent 2009; 22(4): 241-8. 5. grbic jt, lamster ib, fine jb, lam ks, celenti rs, herrera-abreu m, et al. changes in gingival crevicular fluid levels of immunoglobulin a following therapy: association with attachment loss. j periodontol 1999; 70(10):1221-7. 6. brandtzaeg p. immunology of inflammatory periodontal lesions. int dent j 1973; 23: 483-54. 7. genco rj. immunoglobins and periodontal disease. j periodontal 1970; 41:196-201. 8. di carlo, carollo o, tringali g. salivary immunoglobulins in periodontal disease. j minerva stomatol 1971; 20: 262-5 9. burnett gw, scherp hw. oral microbiology and infectious disease. 3rd ed. baltimore: williams and wilkins co.; 1968. 10. armitage gc. development of a classification system for periodontal diseases and conditions. ann periodontol 1999; 4(1):1-6 11. silness j, loe h. periodontal disease in pregnancy ii, correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22:121-35 12. loe h, silness j. periodontal disease in pregnancy i. prevalence and severity. acta odontol scand 1963; 21: 533-51. 13. listgarten ma. periodontal probing: what dose it mean j clin periodontol 1980;7:165 14. sigurd p. ramfjord. the periodontal disease index (pdi). j periodontol 1967; 38(6): 602-10 15. marcotte h, lavoie mc. oral microbial ecology and the role of salivary immunoglobulin a. micro mol biol rev1998; 62:71-109. 16. shah m, doshi y, hirani sh. concentration of salivary immunoglobulin a, in relation to periodontal disease, plaque, and calculus. j intern clin dent res org 2010; 2(3): 126-9. variables chronic periodontitis (siga) (356)µg/ml gingivitis (siga) (202)µg/ml control (siga) 129.2µg/ml r p-value r p-value r p-value pli +0.571 0.0008*** +0.323 0.08* +0.256 0.28* gi +0.71 0.000*** +0.312 0.09* +0.109 0.67* ppd +0.450 0.04** cal +0.104 0.5* j bagh college dentistry vol. 27(3), september 2015 measurement of salivary oral and maxillofacial surgery and periodontics 123 17. bergdahi m. salivary flow and oral complaints in adult dental patients. community dent oral epidemiol 2000; 28: 59-66. 18. gronblad ea. concentration of immunoglobulins in human whole saliva: effect of physiological stimulation. acta odontol scand 1982; 40: 86-95. 19. ben-aryeh h,naon h,szargel r,horowitz g, gutman d. the concentration of salivary iga in whole and parotid saliva and the effect of stimulation. international j oral maxillofac surg 1986;15:81-4. 20. challacombe sj, percival rs, marsh pd. age –related changes in immunoglobulin isotypes in whole and parotid saliva and serum in healthy individuals. oral microbial immunol1995; 10:202-7. 21. miletic id; schiffman ss, miltic vd, sattely-miller ea.salivary iga secretion rate in young and elderly persons. physiol behav1996; 60: 243-8. 22. demetriou n, drikos g, bambionitakis a. relation between gingival fluid and mixed and parotid salivary iga. j periodontal 1978; 49: 64-6. 23. guven o, de visscher jg. salivary iga in periodontal disease. j periodontal 1982; 53: 334-5. 24. butchibabu k, swaminathan m, kumar s, koppolu p, kiran k, muralikrishna t. estimation of salivary immunoglobulin a levels in gingivitis and chronic periodontitis patients before and after phase i periodontal therapy. journal of university of health sciences 2014;3(supplement-1):s23-27.[ivsl] 25. branco-de-almeida ls, alves cm, lopes ff, et al. salivary iga and periodontal treatment needs in diabetic patients. braz oral res 2011; 25: 550-5 نوع أ ھي احد انواع االجسام المضادة المھمة للمناعة وھي تلعب دور حیوي ومھم في مناعة وحفظ االغشیة ان االجسام المضادة المفرزة من: الخالصة ب جھاز المناعة والتھابات المخاطیة وھو یوجد بوفرة في االفرازات المخاطیة لغدد الدمع والغدد اللعابیة والغدد اللبنیة وھو ذا اھمیة في العملیات التي تتطل الدراسة تمثلت بجمع عینات من اللعاب لمرضى النساغ المزمن ومجموعة من من المصابین بالتھاب اللثة البسیط .االنسجة المحیطة باالسنان لیست بمعزل عنھا لمجموعة مرضى النساغ المزمن ) أ(الجسم المضاد نتائج ھذا البحث اظھرت ارتفاعا ملحوظا في تركیز) أ(ومجموعة ضابطة وتم قیاس الجسم المضاد نوع .وان ھناك فرقا معنویا كبیر عند مقارنة المجامیع الثالثة 10 j bagh college dentistry vol. 31(3), september 2019 antimicrobial efficacy s antimicrobial efficacy of silver, zinc oxide, and titanium dioxide nanoparticles incorporated in orthodontic bonding agent sarah yousif hailan b.d.s. (1) mustafa m. al-khatieeb b.d.s., m.sc. (orthodontics) (2) abstrat background: one of the most important complications of fixed orthodontic treatment is formation of white spots, which are initial carious lesions. addition of antimicrobial agents into orthodontic adhesive material might be wise solution for prevention of white spots formation. the aim of this study was to evaluate the antibacterial properties of orthodontic adhesive primer against s. mutans after adding the three different types of nanoparticles (ag, zno, or tio2). materials and methods: discs were prepared using empty insulin syringe approximately 2 mm×2 mm rounded in shape specimens (40 discs) were divided into four groups (ten discs for each group): the first group was the control (made from primer only), the second group (10 discs made from primer and incorporation of ag nps), the third group (10 discs made from primer and incorporation of zno nps), and the fourth group (10 discs made from primer and incorporation of tio2 nps). the antibacterial properties of orthodontic bonding agent after incorporation of (ag, zno, or tio2) nanoparticles were evaluated by disc diffusion test and viable count of mutans streptococci. results: the results of this study showed that there were high significant differences between the all groups using anova f-test, and the colony forming unit were 99×10³, 39.6×10³, 19.4×10³, 6.6×10³ cfu/ml respectively. conclusion: the incorporation of these nanoparticles (ag, zno, or tio2) into transbond ™ xt adhesive primer helps to enhance the antibacterial properties of primer against the s. mutans. keywords: mutans streptococci, nanoparticles, antimicrobial activity, silver, zinc oxide, titanium dioxide. (received: .29/11/2018; accepted: 2/1/2019). introduction both the brackets and bonding adhesive materials may retain plaque as a result of this new site is susceptible to caries, because of the level of streptococcus mutans is significantly increased in the saliva and plaque of patients who are undergoing to fixed orthodontic appliance treatment, and the result is elevated risk of the caries (1,2). nanofillers can minimize enamel demineralization with no deterioration of physical properties of the composite (3). researchers confirmed that new adhesive system composed of silver nanoparticles (ag) provided an excellent antibacterial properties (4). zincbased nanoparticles are stated to bring persistent harmful effects in animal studies in vitro (5). several studies have reported that resins containing tio2 nanoparticles show antimicrobial properties which may be applied for preventing frequent caries and demineralization of the enamel (6-8). the silver, zinc oxide, and tio2 have proper antibacterial activity and when they convert into nanoparticles their surface to volume ratio increases, and this will improving their antibacterial activity (9-11). (1)master student, department of orthodontics, college of dentistry, university of baghdad. (2)assistant professor, department of orthodontics, college of dentistry, university of baghdad. materials and methods adhesive preparation: the primer of the first group was left without any additives (control), while the 2nd group, 1% silver nanoparticles (80nm, purity 99%) were incorporated to the primer (12-15), the 3rd group, 1% zinc oxide nanoparticles (50nm, purity 99%) were incorporated to the primer (14,16,17), and 4th group, 1% titanium dioxide nanoparticles (25nm, purity 99%) were incorporated to the primer (7,8,14,18), each mixture (a primer with one type of nanoparticle) was placed in a test tube covered with foil and mixed for 2 min using vortex machine (huma twist, wiesbaden, germany) to create uniform homogenous mixture (figure 1). figure 1: the primer agents after adding the nanoparticles. 11 j bagh college dentistry vol. 31(3), september 2019 antimicrobial efficacy s discs preparation discs were prepared using empty insulin syringe (1ml) (amart, new delhi, india), the syringe sliced using hand piece at 3200 rpm to form disc that are approximately 2mm×2mm rounded in shape specimens, 40 discs were prepared and divided into four groups (one control group, and three test groups according to the type of nanoparticles which had incorporated), and four bonding mixture groups added to the discs separately (ten discs for each group) and light cured for 40 seconds, which are the control group with primer only without adding nps, and three experimental groups which were 1% ag nps, 1% zno nps, and 1% tio2 nps. after setting these discs kept in sterilized containers until antimicrobial test (19). figure 2. figure 2: a. insulin empty syringe 1ml; b. slicing by hand piece; c. the mold obtained. agar plate preparation: mitissalivarius bacitracin agar (msb agar) this agar is the selective medium for the mutans streptococci. it was prepared from mitis salivarius agar (msa) according to hi-media company instructions with 20% (w/v) sucrose and 200i.u/l bacitracin (20,21). the preparation of media was done according to the instructions of manufacturer by suspending 90gm of the powder in 1000ml distilled water, mixed well by magnetic stirrer (zhongxing, taiwan, china) to ensure dissolution of the entire quantity of the powder, to increase the specialty of msb agar to the isolation of mutans streptococcus, before sterilization, the addition of sucrose in a concentration of 150 gm/l was done. the medium was cool to about 45°c after autoclaving at 121°c for 15 min under 15 psi then left to cool till 45-50°c after that 1ml of bacitracin solution was added for each one liter of the agar. the preparation of bacitracin stock solution was done by dissolving 0.364g of powder in 100ml of sterilized distilled water mixed well by magnetic stirrer to make sure dissolution of the whole quantity of the antibiotic, this will provide concentration of 200 i.u/l. the solution was pure by millipore filter (0.20µm) (fisher scientific, wien, austria) until use, it will be kept in refrigerator. a new solution was prepared each two weeks (20,22), then it was poured in petri dishes and allowed to cool and set then stored in the refrigerator (samsung, south korea) at 2-8°c until used, according to the instruction of hi media company (23). figure 3. figure 3: mitissalivarius bacitracin agar blood agar. the preparation of media was done according to the instructions of hi media company by adding 40 gm in 1000ml distilled water, heated to the boiling temperature at 80°c to dissolve the medium completely, sterilized by autoclaving at 15 psi 121°c for 15 min, then cooled to 45-50 °c, and aseptically added 5% v/v defibrinated blood, furthermore, mixed well and poured into sterile petri dish (22,23). identification of mutans streptococci a. morphological characteristics: mutans streptococci were examined under light microscope (magnification x 15) (olympus, tokyo, japan), the colonies appear light blue in color about 1-2 mm in diameter as spherical or ovoid in shape with raised or convex surface, adhered well to the agar surface. most of mutans streptococci colonies has a depression at the middle of the colony containing a drop of polysaccharide, or sometimes the whole colony submerged in a pool of polysaccharide (24,25). b. gram’s stain one or two colonies were selected from msb agar under sterilized condition and subjected to gram’s stain (vaccine and sera institute, hadapsar, india) (26). c. biochemical tests the following tests were conducted: 1catalase production test a small amount of pure isolates of mutans streptococci were transferred individually using a sterile loop to the surface of clean dry glass slide. drops of hydrogen peroxide 3% (gemtek, new jersey, usa) a a b c b c b a 12 j bagh college dentistry vol. 31(3), september 2019 antimicrobial efficacy s directly onto a portion of bacterial culture on the slide (citotest, nantong, china), the absence of catalase enzyme indicated by absence of gas bubbles, this test can be done also on the colonies of msb agar plates directly (27). 2carbohydrate fermentation test for mutans streptococci in order to evaluate the ability of ms to ferment the mannitol, cystine trypticase mannitol agar had been used, the mannitol was added in a concentration of 1% to the cystine trypticase agar and spread into screw capped bottles (10ml in each bottle) and sterilized by autoclave, then kept in the refrigerator at 2-8oc until used. each bottle was inoculated with 0.1ml of pure ms isolates and incubated aerobically at 37oc for 48 hours. the color will be changed from red to yellow that means there is a positive reaction as a result of acid production from the fermentation reaction (28). the antibacterial activity assay: a. determining the antimicrobial activity of different nanoparticles on the mutans streptococci growth group: kirbybaure disk diffusion test was performed. three or four well isolated colonies of mutans streptococci from msb agar were suspended in 5ml sterile normal saline to achieve 0.5 mcfarland turbidity to produce a stock suspension (29). a sterile swab was immersed into this suspension and excess fluid was pushed out. the brain heart agar was swabbed carefully in three directions to achieve uniform growth on the surface of the agar plate (30). after the agar surface has been left for about five min, then the discs (with and without nps) were placed on the agar and the plates were kept at room temperature for 120 min for diffusion of the antimicrobial agents (31), then these agar plates were incubated aerobically at 37ºc for 24 hours. in order to measure the inhibition zone that may appear around the discs, a polygauge caliper was used (29). figure (4). figure 4: the discs placed inside the bhi agar b. the effect of nanoparticle loaded resins on viable count of mutans streptococci group colonies: to examine the antimicrobial activity of the primer with ag, zno, or tio2 nps. mutans streptococci was diluted in 0.9% nacl, and suspension of approximately 1.5×108 cfu/ml, a 0.5 mcfarland standards was prepared using a mcfarland densitometer, this was done by transferring 1-2 colonies of streptococci mutans from 24 hours cultures of blood agar to obtain the suspension (32,33). by micropipette 1000μl of prepared bacterial suspension was inoculated into 9ml of brain-heart infusion broth under sterile condition (34), and serially dilution was done by adding 1000μl to the second tube of 9ml of bhi-broth, then adding 1000μl from the second tube to the third one 10-3 (bhi-broth with 9ml), and the sterile discs that were going to be examined placed individually into the inoculated tubes, and incubated at 37ºc for 1 hour under aerobic condition, after that each disc removed from tubes and placed in 5ml normal saline, and shacked by vortex mixer for 2 min to allow releasing of bacteria from the specimen surface, then 100µl from this solution was taken by micropipette and spread on blood agar, and incubated aerobically for 24 hours at 37ºc (35-38). the final count (number of bacteria per milliliter) was calculated in the following equation: colony forming unit per ml (cfu/ml) = colony number/ dilution factor (36,37). figure 5. figure 5: a. placement of specimen in the normal saline; b. shacked by auto vortex for 2 min; c. add 100 µl to the blood agar statistical analysis all statistical tests and calculations were made using statistical package for social science software (spss for windows, 19.0, chicago, usa). testing the normality of data distribution was carried out by using shapirowilk test. maximum, minimum, mean values, standard error and standard deviations were 13 j bagh college dentistry vol. 31(3), september 2019 antimicrobial efficacy s calculated as part of the descriptive analysis. statistical significances were measured using one way (anova) to discover the difference among the four groups, and post hoc tukey's test used to test further any statistically significant difference between each two groups. results evaluating viable count of sm (cfu/ml) testing the normality of data distribution was carried out by using shapirowilk test, in order to apply the correspondence statistical test. the results showed that there was no significant difference in all the groups of antimicrobial test; as shown in table1, while descriptive statistics and f-test analysis of variance (anova) of mean values of cfu/ml in different groups were evaluated, there was high significant difference among the groups as shown in table 2, also post hoc tukeyʾs test was used to test the mean differences and showed that there were high significant differences in cfu/ml between the control group and all tested groups; as shown in table 3. table 1: testing the normality of data distribution for the antimicrobial test in the various groups. groups shapiro-wilk d.f. p-value control 0.940 10 0.554 (ns) ag 0.941 10 0.562 (ns) zno 0.918 10 0.345 (ns) tio2 0.952 10 0.692 (ns) ns: non significant table 2: descriptive statistics and f-test (anova) of the cfu/ml. hs: highly significant table 3: post hoc tukey’s test of the cfu/ml in different groups. groups mean difference p-value control ag 59.4×10³ 0.001 (hs) zno 79.6×10³ 0.001 (hs) 2tio 92.4×10³ 0.001 (hs) ag zno 20.2×10³ 0.001 (hs) 2tio 33×10³ 0.001 (hs) zno 2tio 12.8×10³ 0.001 (hs) hs: highly significant discussion identification of mutans streptococci a. colony morphology ms colonies appeared light blue in color, about 1-2 mm in diameter as spherical or ovoid in shape with raised or convex surface, adhered well to the mitis salivarius agar surface, this media has selective and differential properties because it contained bacitracin which inhibits the growth of other type of bacteria (39). b. gram stain test the gram stain was used because it was the most useful and widely employed differential stain in bacteriology. the ms bacteria was gram positive, which stained with the basic dye crystal descriptive statistics comparison (df=39) groups n mean s.d. s.e. min. max. f –test d.f=39 p-value control 10 99×10³ 7.57 2.39 89 110 346.873 0.001 (hs) ag 10 39.6×10³ 10.28 3.25 26 56 zno 10 19.4×10³ 4.93 1.56 14 30 2tio 10 6.6×10³ 2.37 0.75 3 10 14 j bagh college dentistry vol. 31(3), september 2019 antimicrobial efficacy s violet, this is the primary stain, it is followed by treatment with an iodine solution, which functions as a mordant; it increases the interaction between the bacterial cell and the dye, so that the dye is more tightly bound or the cell is more strongly stained (36). c. biochemical tests 1. catalase production test this test demonstrates the presence of catalase enzyme, it was used to differentiate bacteria that produce an enzyme catalase or not. the enzyme catalase facilitates the breakdown of hydrogen peroxide into oxygen and water. the presence of the enzyme in a bacterial isolate was evident when the rapid elaboration of oxygen bubbles occurs. the lack of catalase enzyme was evident by a lack of or weak bubble production (40). 2. carbohydrate fermentation test about 1% of specific carbohydrate (which was one of components of cystine trypticase manitol agar) was used to detect fermentation reactions. changing the color of the indicator (phenol red) from red to yellow which points the fermentation of carbohydrate and acid production (41-43). disc diffusion test and plate counted method in some studies, diffusion agar disc technique has been used to evaluate antibacterial properties (44-46). in the current study, the adhesive materials do not form the growth inhibitory zone, the fact behind that is the direct contact of the nanoparticles that were added to the primer of the adhesive with bacteria is minimal (9,44,46). however, turbidity measurements are limited, as they count both dead and vital bacteria present together in a biofilm layer (47). the contact area of nanoparticles with bacterial micro-organisms is higher in a serial dilution method compared to the culture media, thus increasing their antibacterial effect (11). therefore, the obtained results of this study are depend on plate count method in which a viable cell count allows one to identify the number of actively growing cells in a sample, the plate count method or spread plate relies on bacteria growing ability to form a colony on a nutrient medium, the colony becomes visible to the naked eye and the number of colony on a plate can be counted (36). the results of the present study showed that the number of colonies of viable bacteria of streptococcus mutans in the control group was significantly higher than that in the three other tested groups after incorporating the nanoparticles (ag, zno, or tio2) to the transbond xt primer because these types of nanoparticles provide an excellent antibacterial activities (4-8), and this agreed with researchers (7,12). a highly significant difference was found between ag group and the control group, this may be due to high antibacterial properties of ag nps, this result agreed with other studies (8,1012,48). a highly significant difference was found between zno group and the control group, this may be due to the zno nps serves as an activator of enzymes that can be toxic to bacteria, this result agreed with other studies (11,12,46,49). a highly significant difference was found between tio2 group and the control group, and this may be due to tio2 nps have a broad spectrum antimicrobial agent, this result agreed with (7,8,48,49). in addition there is a highly significant difference between ag group and zno group (antimicrobial activity of zno group was higher than ag group), this may be due to the particle size of zno nps relative smaller than the size of ag nps, this result agreed with researchers (12,49), but contrary to the result of others (11), in which they evaluated the effects of silver (25 nm), and zinc oxide (125 nm) nanoparticles on streptococcus mutans and reported that the antibacterial activity of silver nanoparticles is much higher than those of zinc oxide and gold nanoparticles, these differences might be attributed to the size of the applied nanoparticles. furthermore, our study showed that there were a highly significant differences between tio2 and ag groups, and tio2 and zno groups (antimicrobial activity of tio2 group was higher than ag and zno groups), this may be due to the size of tio2 nps relative smaller than the size of ag and zno nps, these results in accordance with a study (49), but disagreed with another (48), who found that the antimicrobial effect of ag nanoparticles on ms was more than that of tio2 nanoparticles, this may be attributed to the difference in size of applied nanoparticles that was used in their studies. the antimicrobial activity of ag, zno, and tio2 nps appeared to be particle size dependent, the smaller particle size will lead to efficient ions release due to their large surface-to-volume ratio that could enable them to discharge more ions at a low concentration, this may result in defect in bacterial cell wall, so that the cell contents are lost and this result can agree with other studies (10,11,46) . in the current study, the incorporation of these nanoparticles (ag, zno, and tio2) into transbond ™ xt adhesive primer helps to enhance the antibacterial properties of primer against the streptococcus mutans. 15 j bagh college dentistry vol. 31(3), september 2019 antimicrobial efficacy s references 1. artun j, brobakken bo. prevalence of carious white spots after orthodontic treatment with multi bonded appliances. eur j orthod 1986; 8(4): 229-34. 2. al-musallam ta, evans ca, drummond jl, matasa c, wu cd. antimicrobial properties of an orthodontic adhesive combined with cetylpyridinium chloride. am j orthod dentofacial orthop 2006; 129(2): 245-51. 3. xia y, zhang f, xie h, gu n. nanoparticlereinforced resin-based dental composites. j dent 2008; 36(6): 450-5. 4. ahn sj, lee sj, kook jk, lim bs. experimental antimicrobial orthodontic adhesives using nanofillers 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https://www.ncbi.nlm.nih.gov/pubmed/?term=vankhre%20m%5bauthor%5d&cauthor=true&cauthor_uid=27843887 https://www.ncbi.nlm.nih.gov/pubmed/?term=vankhre%20m%5bauthor%5d&cauthor=true&cauthor_uid=27843887 https://www.ncbi.nlm.nih.gov/pubmed/?term=khan%20my%5bauthor%5d&cauthor=true&cauthor_uid=27843887 https://www.ncbi.nlm.nih.gov/pubmed/?term=kumar%20tr%5bauthor%5d&cauthor=true&cauthor_uid=27843887 https://www.ncbi.nlm.nih.gov/pubmed/27843887 16 j bagh college dentistry vol. 31(3), september 2019 antimicrobial efficacy s 33. hussian am, jassim rk. effect of sodium fluoride addition as a disinfectant on some properties of alginate impression material. j bagh college dent 2015; 27(1):70-6. 34. issa mi, abdul-fatah n. evaluating the effect of silver nanoparticles incorporation on antifungal activity and some properties of soft denture lining material. j bagh college dent 2014; 27(2): 17-23. 35. baron e, peteson l, fingold s. methods for testing antimicrobial effectiveness. in: bailey and scotts diagnostic microbiology. 9th ed. cv mosby co, st. louis, 1994. 36. harley jp, prescott lm. laboratory exercises in microbiology, 5th ed. new york, ny, 2002. 37. casemiro la, martins chg, panzeri fdc, souza p, panzeri h, ito iy. bacterial, fungal and yeast contamination in six brands of irreversible hydrocolloid impression materials. braz oral res 2007; 21(2): 106-11. 38. shakir ta, abass sm. the effect of magnesium oxide (mgo) nano fillers on the antibacterial activity and some properties of heat cured acrylic resin. int j sci res 2016; 7(3): 2319-7064. 39. nolte wa. oral microbiology: with basic microbiology and immunology, 1982. 40. aryal s. catalase testprinciple, uses, procedure, result interpretation with precautions, 2018. 41. köhler b, andréen i, jonsson b. the earlier the colonization by mutans streptococci, the higher the caries prevalence at 4 years of age. oral microbiol immunol 1988; 3(1): 14-7. 42. hamilton ir, buckley nd. adaptation by streptococcus mutans to acid tolerance. oral microbiol immunol 1991; 6(2): 65-71. 43. marsh pd. microbial ecology of dental plaque and its significance in health and disease. adv dent res 1994; 8(2): 263-271. 44. imazato s. antibacterial properties of resin composites and dentin bonding systems. dent mater 2003; 19(6): 449-57. 45. kumar r, münstedt h. silver ion release from antimicrobial polyamide/silver composites. biomaterials 2005; 26(14): 2081-8. 46. aydin sevinç b, hanley l. antibacterial activity of dental composites containing zinc oxide nanoparticles. j biomed mater res b appl biomater 2010; 94b(1): 22-31. 47. guggenheim b, giertsen e, schupbach p, shapiro s. validation of an in vitro biofilm model of supragingival plaque. j dent res 2001; 80(1): 36370. 48. besinis a, de peralta t, handy rd. the antibacterial effects of silver, titanium dioxide and silica dioxide nanoparticles compared to the dental disinfectant chlorhexidine on streptococcus mutans using a suite of bioassays. nanotoxicology, 2014; 8(1): 1-16. 49. ahrari f, eslami n, rajabi o, ghazvini k, barati s. the antimicrobial sensitivity of streptococcus mutans and streptococcus sangius to colloidal solutions of different nanoparticles applied as mouthwashes. dent res j 2015; 12(1): 44-9. الخالصة صق تقويم لللجراثيم الى ماده عوامل مضاده اضافه ان واحده من اهم التعقيدات في عالج تقويم االسنان الثابت هو تكوين البقع البيضاء، وهي بدايه االفه التسوسيه. الميوتانز لـ تيريا المكورات العقديه الخصائص المضاده لبكهي تقييم االسنان قد تكون الحل الحكيم لمنع تكوين البقع البيضاء. االهداف من هذه الدراسه (transbond xt primer نظام ))لصق تقويم االسنان بعد اضافه ثالث انواع مختلفه من جزيئات النانو)الفضه، اوكسيد الزنك، وثنائي اوكسيد التيتانيوم. قرص مصنوعه من )الفضه ، اوكسيد الزنك، وثنائي 30فقط و transbond xt primer اقراص مصنوعه من 10( قرص تم تحضيره، 40مجموعه من ) اعداد المستعمرات القابله للحياه تم اختبار الخصائص المضاده للبكتريا عن طريق تحديد transbond xt primer مع اوكسيد التيتانيوم النانوية( بعد خلطها للمكورات العقديه الميوتانز. وم وباقي المجموعات تظهر فروقات كبيره بين المجاميع االربعه حيث ان مجموعه ثنائي اوكسيد التيتانيالمسيطرعليها مقارنه التاثير المضاد للبكتريا بين المجموعه تملك اعلى قيمه لعدد المستعمرات. المسيطرعليهاالنانوي تملك اقل قيمه لعدد المستعمرات وبعدها مجموعه اوكسيد الزنك ، وثم الفضه النانويه في حين المجموعه تقويم االسنان سيعزز تاثيره المضاد للبكتريا وهذا في نظام اللصق في primerفي الختام، اضافه )الفضه، اوكسيد الزنك، او ثنائي اوكسيد التيتانيوم( النانوي الى .يعتمد على حجم جزيئات النانو)حجم جزء النانو االصغر يتملك النشاط المضاد للبكتريا االعلى( https://www.sciencedirect.com/science/journal/01429612 https://www.sciencedirect.com/science/journal/01429612/26/14 https://www.ncbi.nlm.nih.gov/pubmed/?term=besinis%20a%5bauthor%5d&cauthor=true&cauthor_uid=23092443 https://www.ncbi.nlm.nih.gov/pubmed/?term=de%20peralta%20t%5bauthor%5d&cauthor=true&cauthor_uid=23092443 https://www.ncbi.nlm.nih.gov/pubmed/?term=handy%20rd%5bauthor%5d&cauthor=true&cauthor_uid=23092443 https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3878355/ https://www.ncbi.nlm.nih.gov/pubmed/?term=ahrari%20f%5bauthor%5d&cauthor=true&cauthor_uid=25709674 https://www.ncbi.nlm.nih.gov/pubmed/?term=eslami%20n%5bauthor%5d&cauthor=true&cauthor_uid=25709674 https://www.ncbi.nlm.nih.gov/pubmed/?term=rajabi%20o%5bauthor%5d&cauthor=true&cauthor_uid=25709674 https://www.ncbi.nlm.nih.gov/pubmed/?term=ghazvini%20k%5bauthor%5d&cauthor=true&cauthor_uid=25709674 https://www.ncbi.nlm.nih.gov/pubmed/?term=barati%20s%5bauthor%5d&cauthor=true&cauthor_uid=25709674 zainab f.doc j bagh college dentistry vol. 25(2), june 2013 cbct analysis oral diagnosis 114 cbct analysis of impacted maxillary canines zainab h. al-ghurabi, b.d.s., h.d.d., m.sc. (1) abstract background: this study designed to shade light on the important role of cbct in accurate localization of the impacted maxillary canines. materials and method: fifty two unilateral and bilateral impacted maxillary canines from 30 patients (24 females and 6 males) were evaluated by a volumetric 3d images obtained from cone beam ct. all samples attended to the specialist health center of dentistry in al-sadder city referred to cbct by oral surgeons or orthodontists to detect the exact position of impacted upper canine in cases when there was no bulging buccally or palatally which aids to detect the exact position. results: mesio-palatal angulations had the highest rate (63.5%) followed by mesio-labial (19.2%), vertical (labial) (9.6%), disto-palatal (5.8%) and disto-labial (1.9%). the relation between impacted canine and the adjacent teeth regarding to the attachment was significant only with lateral incisor. no cases of root resorption of the adjacent teeth were recorded. bilateral impacted teeth were found in 22 patients which is highly significant (especially in females), while unilateral impaction was found only in 8 patients especially in females. impacted canine was more prominent in female whether unilateral or bilateral. conclusions: cbct imaging of impacted canines can show the following: presence or absence of the canine, angulations of the long axis of the tooth, relative labial and palatal positions and proximity to adjacent teeth. in short, cbct imaging is clearly advantageous in imaging and management of impacted canines. key words: cbct, impacted maxillary canine. (j bagh coll dentistry 2013; 25(2):114-118). introduction orthodontic treatment of impacted maxillary canine remains a challenge to today’s clinicians. the treatment of this clinical entity usually involves surgical exposure of the impacted tooth, followed by orthodontic traction to guide and align it into the dental arch. bone loss, root resorption and gingival recession around the treated teeth are some of the most common complications (1). early diagnosis and intervention could save the time, expense and more complex treatment in the permanent dentition. tooth impaction can be defined as the infraosseous position of the tooth after the expected time of eruption, whereas the anomalous infraosseous position of the canine before the expected time of eruption can be defined as a displacement. most of the time, palatal displacement of the maxillary canine results in impaction (2). accurate diagnostic imaging is an essential requirement to derive the correct diagnosis and optimal treatment plan, as well as monitor and document the treatment progress and final outcome (3). two-dimensional (2d) diagnostic imaging, including traditional radiographs, cephalometric tracings, photographs and video imaging, has been a part of the orthodontic patient record for decades. the limitations in analysis of these imaging modalities are well known, and include magnification, geometric distortion, superimposition of structures, projective displacements (which may elongate or foreshorten (1) assistant lecture, department of oral diagnosis, college of dentistry, university of baghdad. an object's perceived dimensions), rotational errors and linear projective transformation (4,5)., in contrast, three-dimensional (3d) imaging allows for the evaluation and analysis of “the anatomical truth (6,7). more recently, this high-resolution imaging technique has gained importance in diagnosing dental-associated diseases of the mandible and maxilla. cbct (3d) offers super visualization of impacted teeth and can help the clinician to plan his treatment preoperatively or prior to orthodontic therapy (figure 1) (8-10). dental ct investigations can be performed either on cbct (cone beam computed tomography) or multi-detector spiral ct scanner. the device should be capable of performing highresolution scans with a small focal spot and acquiring thin slices of 1.5 mm or less. the position of the tooth within the alveolar crest as well as the relation to surrounding structures is clearly disclosed. impacted and transposed teeth are possibly the most common reason for use of dental ct imaging in orthodontics. the information derived can enhance the ability to localize impacted teeth, identify pathological conditions and root resorption, help plan surgical access and bond placement, and define the optimal and most efficient path for extrusion into the oral cavity that avoids or minimizes collateral damage (2). furthermore, cbct scans can provide diagnostic information on roots of the adjacent teeth that are in close proximity to the impacted tooth or in its traction path that can be moved proactively and avoid causing damage. another advantage of dental ct over routine radiographs j bagh college dentistry vol. 25(2), june 2013 cbct analysis oral diagnosis 115 includes the accurate measurement of the impacted tooth to aid in determining and developing the space needed for the tooth. this study designed to shade light on the important role of cbct in accurate localization of the impacted maxillary canines. subjects, materials and method the study sample comprised 30 patients with (52) impacted maxillary canines, (24 females) with 44 impacted canines and (6 males) with 8 impacted canines, with an age ranged from 10 to 20 year and the age distribution in relation to the gender clear in table (1). these patients were referred to specialist center of al-sadder city for localization of these impacted canines, using kodak 9500 cbct. the investigation performed with 90 kv, 10 ma, 1mm slice thickness and 10.8 seconds time of exposure. the images were collected from the workstation of the ct unit. before investigation every patient asked about name and age then asked the patient to remove any metal object, to avoid distortion, and not to move or breathe while exposure performed. the plane for primary reconstruction is aligned parallel to the occlusal plane. the reconstruction volume ranges within many axials for inspection of the relationship between the impacted canines and peripheral bony and dental structures. imaging data were analyzed with the software provided by the manufacturer. the following records were evaluated in the ct workstation for every subject: (1) the three dimensional variations of impaction—in each case, the vertical inclination was considered first, followed by the mesio-distal migration and buccopalatal crown location (2) contact of impacted canine to the adjacent incisor. after that, on the work station, each case diagnosed with 3d volumetric image (as shown in fig 2) to diagnose the impacted canine from all directions, in addition to this volumetric images, all of the samples diagnosed with multiple axial slices to show its exact direction and its relation to labial or palatal alveolar bone, (as shown in figure 2-a) and diagnosed with sagittal slice to show its position laterally and assess the amount of bone that covered the impacted tooth labially and palatally and its relation with adjacent structure (as shown in figure 2-b,c). coronal slice also used to detect canine position anteroposteriorly as shown in figure 2-d). results regarding the site of impacted canine, it was found that the ratio of bilateral impacted upper canine was (84.7%), (which is highly significant) than the ratio of unilateral impacted upper canine (15.3%) (which is non-significant), as shown in table 2. as clear in the same table the female ratio is higher in bilateral (77%) than unilateral (7.7%) and the ratio of impacted upper canine in females was higher than males. as shown in table 3, according to the direction of impacted upper canine, the percentage of palatal direction was (69.3%) higher than the percentage of labial direction (30.7%). according to the canine angulation, the mesiopalatal angulations was higher among the others (63.5%), as clear in this table only this angulation was significant, followed by mesio-labially (19.2%), vertico-labial (9.6%), disto-palatally (5.8%) and the lowest percentage was distolabially (1.9%). according to the relation of impacted canine with the adjacent teeth, it was found that the highest rate of attachment with impacted canine was the lateral incisor (88.46%) which was significant. discussion peck et al. (13) stated that the etiology of palatally impacted canines is genetic in origin, while the etiology of labially impacted canines is due to an inadequate arch space.(11-13). in this study, it was found that, bilateral impacted canine more frequent than unilateral and this may be related to genetic factor and this result come in accordance with many studies (11,12,15-17). female ratio of impacted canine was higher than male generally and in bilateral impaction especially, this result comes in agreement with other studies (13,14). in the current study, impaction was summarized into 4 variations, with an aim of convenient description of the complex locations of impacted canines. mesio-palatal impacted canines were the most common representing (63.5%) of the study sample, followed by mesiolabialy (19.2%), vertico-labialy (9.6%), distopaltaly (5.8%), and disto-labialy (1.9%) respectively, while there is no vertico-palataly case in this study. from these results, it could be concluded that, the palatal direction more than buccal direction and this come in confirm with many studies (14-17) who stated that the palatal direction of impacted upper canine is twice or more than labial direction while disagree with peck et al. (13), who stated that, in asian the j bagh college dentistry vol. 25(2), june 2013 cbct analysis oral diagnosis 116 impacted canine usually labial, and this may be due to different race and sample size. relation between the impacted canine & the adjacent teeth is very important point because this impacted canine may cause resorption to the adjacent teeth when its direction or angulations very near or overlap these adjacent teeth. however in the present study there was no resorption in the adjacent teeth but there was touch them (resorption of palatal or labial bone), the most teeth that touched with impacted canine were central and lateral incisors when its angulations mesially and vertically (palatally or labial direction) and 1st and 2nd premolars when its angulations distally (palatal or labial direction). in this study only lateral incisor was significantly touched with impacted canine (without resorption of its root) and this may be regarding to its pathway of eruption, although the remaining teeth touched to the impacted canine but it’s not significantly as with lateral incisor. references 1. bishara se, kommer dd, mcneil mh, montagana ln, oesterle lj, youngquist hw. management of impacted canines. am j orthod 1976; 69: 371–87. 2. power sm, short mb. an investigation into the response of palatally displaced canines to the removal of deciduous canines and an assessment of factors contributing to a favourable eruption. br j orthod 1993; 20: 215–23. 3. shortliffe e, perreault le, wiederhold g, fagan lm. medical informatics: computer applications in health care and biomedicine. 2nd ed. new york: springer; 2001. 4. tsao dh, kazanoglu a, mccasland jp. measurability of radiographic images. am j orthod 1983; 84: 212– 216. 5. adams gl, gansky sa, miller aj, harrell we jr., hatcher dc. comparison between traditional 2dimensional cephalometry and a 3-dimensional approach on human dry skulls. am j orthod dentofacial orthop 2004; 126: 397–409. 6. harrell we jr. 3d diagnosis and treatment planning in orthodontics. semin orthod 2009; 15: 35–41. 7. harrell we jr., stanford s, bralower p. ada initiates development of orthodontic informatics standards. am j orthod dentofacial orthop 2005; 128: 153–156. 8. hirschfelder u. radiological survey imaging of the dentition: dental ct versus orthopantomography. fortschr kieferorthop 1994; 55:14–20 9. bodner l, sarnat h, bar-ziv j, kaffe i. computed tomography in the management of impacted teeth in children. asdc j dent child 1994; 61:370–377 10. krennmair g, lenglinger fx, traxler m. imaging of unerupted and displaced teeth by cross-sectional ct scans. int j oral maxillofac surg 1995; 24:413–416 11. jacobs sg. the impacted maxillary canine. further observations on aetiology, radiographic localization, prevention/interception of impaction, and when to suspect impaction. aust dent j 1996; 41:310-6. 12. mcsherry pf. the ectopic maxillary canine: a review. br j orthod 1998; 25:209-16 13. peck s, peck l, kataja m. the palatally displaced canine as a dental anomaly of genetic origin. angle orthod 1994; 64: 249-56. 14. walker l, enciso r andmah j. three dimentional localization of maxillary canine with cone beam computed tomography. am j orthod dentofacial orthop 2005; 128(4): 418-23. 15. ngan p, hornbrook r, weaver b. early timely management of ectopically erupting maxillary canines. semin orthod 2005; 11(3):152-163. (ivsl). 16. ericson s, kurol j. radiographic examination of ectopically erupting maxillary canines. am j orthod dentofacial orthop 1987; 91(6):483-492. 17. becker a. orthodontic treatment of impacted teeth. 2nd ed. new york ny: informa healthcare; 2007. pp.11. table 1: distribution of maxillary canines according to sex and age in a sample of 30 patients genders no. of patient age range mean ± sd females 24 10-15 12.5 ± 2.53 males 6 15-20 17.01 ± 2.73 total 30 10-20 13.3 ± 3.06 table 2: distribution of impacted canine according to the side involvement in relation to the gender genders bilateral unilateral total no. of patients no. of impacted canine no. of patients no. of impacted canine females 20 40 (77%) 4 4 (7.7%) 44 (84.7%) males 2 4 (7.7%) 4 4 (7.7%) 8 (15.3%) total 22 44 (84.7%) 8 8 (15.3%) 52 (100%) p-value 0.005 p<0.05 s 0.368 p>0.05 ns j bagh college dentistry vol. 25(2), june 2013 cbct analysis oral diagnosis 117 table 3: statistical distribution of impacted canine according direction and angulations of 52 impacted teeth palataly labially total p value no. of cases mesio-palatally disto-palatally mesio-labially distolabially vertical-labially females 30 (68.2%) 3(6.85%) 8 (18.2%) 1 (2.3%) 2(4.5%) 44(100%) 0.022 s males 3 (37.5%) 0(0%) 2 (25%) 0 (0%) 3(37.5%) 8(100%) 0.028 s total 33 (63.5%) 3(5.8%) 10 (19.2%) 1 (1.9%) 5(9.6%) 52(100%) 0.024 s 33 (69.3%) 16 (30.7%) p value 0.0137 sig. ------ 0.13 ns. ----- 0.137 ns. 0.016 s signi ficant table 4: contact relationship between impacted canine and adjacent teeth central incisor lateral incisor 1st premolar 2nd premolar type of contact no touch touch no touch touch touch no touch touch no touch mesio-palataly 9 24 33 mesio-labialy 7 3 10 disto -palataly 2 1 disto-labialy 1 vertico-labialy 3 2 total 16 (30.76%) 27 (51.92%) 5 (9.61%) 46 (88.46%) 1 (1.92%) - p value 0.285 ns 0.283 ns 0.288 ns 0.038 s 0.157 ns _ _ _ figure 1: 3d volumetric image clear bilateral labial directed upper impacted canine in the right and left side for the same patient. j bagh college dentistry vol. 25(2), june 2013 cbct analysis oral diagnosis 118 a b axial sagittal c d sagittal coronal figure 2: multidetcter slices clear impacted upper canine 7. saja f.doc j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 37 the effect of zirconium silicate nanopowder reinforcement on some mechanical and physical properties of heat cured poly (methyl methacrylate) denture base materials saja kareem, b.d.s. (1) mohammed moudhaffer, b.d.s., m.sc. (2) abstract background: polymethylmethacrylate (pmma) has relatively unsatisfactory mechanical properties such as low flexural strength and impact strength also dimensional instability. material and method: zirconium silicate nanoparticles were coated with a layer of trimethoxysilylpropylmethacrylate (tmspm) before sonication in monomer (mma) with the percentages 1% and 1.5% by weight then mixed with powder using conventional procedure, (150) samples were prepared and divided into three groups, each group consisted of (50) samples, the first group prepared from pmma without addition (control), another group with the addition of 1% wt zrsio4 nanoparticles (experimental) and the third one with 1.5% wt zrsio4 nanoparticles (experimental). each group was divided into 5 sub-groups according to the test performed. the tests conducted impact strength, transverse strength, indentation hardness (shore d), surface roughness, water sorption and solubility. the size, shape and distribution of nanofiller were estimated using scanning electron microscope (sem) .the results were statistically analyzed using anova and lsd test. result: highly significant increase in impact strength, transverse strength and surface hardness occurred with the incorporation of 1.5% wt zirconium silicate nanofiller but non-significant increase in impact strength, significant increase in transverse strength and highly significant increase in surface hardness occurred with the incorporation of 1% wt zrsio4 nanofiller. non-significant increase in surface roughness with both 1% and 1.5% wt zrsio4 . highly significant decrease in water sorption and solubility with 1.5% wt zrsio4 nanofiller and non-significant decrease in water sorption and solubility with 1% wt zrsio4 compared with control group. conclusion: the maximum increase in impact strength, transverse strength, and surface hardness was observed in denture base nano composite containing 1.5% zrsio4. in addition, highly significant decrease in water sorption and solubility and non-significant increase in surface roughness was also noticed. key words: poly (methyl methacrylate), nano composite. (j bagh coll dentistry 2015; 27(4):37-43). introduction the most widely used material for construction of complete dentures is poly (methyl methacrylate) resins, because of satisfactory appearance, uncomplicated curing procedure and successful repairing (1-3). however, clinician still encounter that artificial acrylic prosthesis may fracture as a result of sudden fall or continuous flexing by occlusal forces (4-6). water sorption and solubility of denture base pmma have detrimental effects on color stability of the denture base and have negative effects on physical properties and may lead to harmful tissue reaction(7-9). the incorporation of nano reinforcements considerably enhances their mechanical and thermal barrier properties in conjunction with noticeable enhancements in adhesion, rheological and processing behavior. in addition, improved dispersion of the fillers within the matrix gives high performance nano composites and furthermore the properties of the nano scale filler are significantly higher than those of the base matrix. (1)master student. department of prosthodontics. college of dentistry, university of baghdad. (2)assistant professor. department of prosthodontics. college of dentistry, university of baghdad. currently, polymer nanocomposite materials are approaching with the incorporation of nanofiller like nanoclays, nano particles, nanotubes, nanofibers, etc (10,11). silane coupling agent might be used to improve better adhesion of nano particles with a resin matrix (12,13), his study was conducted to use zirconium silicate nanoparticles that were treated with3-trimethoxypropylsilylmethacrylate tmpsm) and were added to heat cured pmma to get pmma/zirconium silicate nanocomposite and study the effects of this addition on some mechanical and physical properties over pure heat cured pmma. materials and methods surface modification of zrsio4 nano fillers: modification of nanofiller was done by the reaction of trimethoxysilyl propyl methacrylate tmspm with zirconium silicate nanopowder. silanation process was as follows: pure toluene solvent in the amount of (175ml) and zrsio4 in the amount of (25gm) were placed into glass beaker of capacity (250ml) and sonicated by ultrasonic probe (hielcher, up200s, germany) for 20 min. as seen in (figure 1). then the beaker was placed on magnetic stirrer (model sh-3, heating power 500 w, stirring speed j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 38 0-1600 r/min, made in england). then 1.25 gm (5% wt to nano filler) of silane was added drop wisely by using sterile syringe under rapid stirrer. the slurry was left for two days and the beaker was covered after that the slurry was placed in rotary evaporator (heidolph laborata – 4000, germany) under vacuum of (600c), rotation of (150 rpm) for (30 min.) as seen in figure (2). finally, the silanated nano particles were moisture free by placing in vacuum oven (vaucell, germany) for (20 hours at 600c), and then stored at room temperature before use(14). the infrared (ir) spectra were performed (shimadzu, ftir, japan) to determine whether or not functional groups of the tmspm have been attached to the nanofiller by analyzing the characteristic vibrations of functional groups(15). figure (1): ultrasonic probe figure (2): rotary evaporator addition of fillers: addition of modified zirconium silicate nano fillers was done in two groups of 1% and 1.5% by weight. an electronic balance with accuracy of (0.0001g) was used; the fillers were dispersed with monomer by using a probe sonication apparatus (200 w, amplitude of the oscillatory system had adjusted on 70%) for 2 minutes to break them into individual nano crystals. the liquid monomer and zrsio4 nanofiller were mixed at once with (pmma) powder. the mixed ratio used for (pmma), was (2.2g: 1ml) p/ l, following manufacturer instructions. selection of proper percentage of zirconium silicate nano fillers: according to the pilot study the addition of 1% and 1.5% nano fillers to pmma had the greatest amount of transverse and impact strength therefore, a decision was made to choose 1% and 1.5% of silanized nano zrsio4 filler, in addition to control group to complete the main study. pattern preparation: three different plastic patterns were constructed by cutting plastic plate in desired shape and dimension by using laser cutting machine according to the required test. transverse strength, surface roughness and shore d. hardness tests: bar shaped specimen with dimensions of (65mm x 10 mm x 2.5 ± 0.1 mm)(16) length, width, thickness respectively, while water sorption and solubility tests: disc with dimensions of 50mm in diameter and 0.5mm in thickness(16). impact strength test: bar shaped specimen with dimensions of (80 mm x10 mm x 4 mm) length, width and thickness respectively(16). mould preparation: the conventional flasking technique for complete denture was followed. proportioning and mixing of the acrylic: table (1): percentages and amounts of polymer, monomer and zirconium silicate nanofiller powder. zrsio4 conc. percentages amount of zrsio4 (g) amount of polymer (g) amount of monomer ( ml) 0% 0g 44g 20 ml 1% 0.44g 43.56g 20 ml 1.5% 0.66g 43.34g 20 ml j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 39 mechanical and physical tests used to examine properties: 1. impact strength: the test sample was supported as a beam on both sides and struck in the midpoint with a pendulum of charpy impact tester of two joules capability (17). unotched sample was used and the energy absorbed by the specimen was recorded in kj/ m2, according to this equation: e/ b.d x 103 (e: impact energy, b: specimen width, d: specimen thickness) (18). 2. transverse strength: the test was performed using a universal instron testing machine, a load was applied in the middle of the testing sample that is supported at each ends separated by a distance of 50mm. the maximum stress was 50 kg, and the load utilized directed in the midpoint of the sample until breakage occur. the speed of the load was 1mm/min, and calculation of transverse strength follows this equation: 3pl/2bd2 (p: peak load, l: span length, b: sample width, d: sample thickness) (18). 3. surface roughness: each specimen was tested for surface roughness using a portable surface roughness tester (profilometer) which can measure small surface variation. this device has a diamond stylus which moves in contact with surface for 11mm. three measurements were done at 3 positions across each specimen surface which was divided into 3 equal thirds and the mean of the 3 readings were recorded, as a roughness measurement. 4. surface hardness: shore d hardness tester was used according to (ansi/ada specification no.12, 1999). the device comprise of a dull end marker of 0.8mm which presents in a container of 1.6mm. the marker (indenter) is connected to a measuring device calibrated from (0-100 unit). generally the indenter is compressed with rapid movement on the sample to record the maximum reading displayed from digital screen. the specimen was divided into 5 equal parts, and shore d was measured in these areas. finally the average of the five readings was recorded. 5. water sorption and solubility: a dissector was used to dry the samples in which fresh silica gel was added, after that they were kept in an incubator at 37oc ± 2oc for one day. then the samples were transferred to room temp for 60 min, and then a digital balance was used to weigh the samples precisely to (0.000g). the same cycle repeated again every day at the same time until a constant mass "conditioned mass'' (m1) was reached after 5 days which means that not greater loss than 0.2mg in 24 hours (ada specification no. 12). after that immersion of the samples in distilled water were continued up to seven days at 370c ± 2 0c, then each specimen carried from water with tweezers and rubbed for 30 seconds by clean dry hand towel, left in air for 15 second then weighed ,this value represent m2. in order to gain the amount of solubility, the discs were again placed in the desiccator at 37°c ±2 °c as mentioned before in sorption experiment and the reconditioned mass was known as m3. the whole group was reached to m3 within 5 days. the calculation of water sorption and solubility was according to the following equations(19): ws= (m2– m1) / s wsl= (m1m3)/ s results ftir test was done to samples of zirconium silicate nanofiller before and after silanation to evaluate the differences in active groups, as seen in figure (3). another ftir was done to pmma/ zrsio4 nano composite before and after silanation of nano filler to evaluate the adhesion of nano particles with polymer matrix as seen in figure (4). figure (3): ftir of zrsio4 before and after silanation figure (4): polymer nano composite before and after silanation before silanation after silanation before silanat after silanatio j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 40 impact strength test: descriptive data of mean, standard deviation, standard error, minimum and maximum and also the anova test and lsd test are listed in table (2). table (2): descriptive data and lsd test of impact strength test. a 0% b 1% c 1.5% anova f-test sig. groups p-value sig. n 10 10 10 27.811 0.000 h.s a&b 0.08 n.s mean 7.0740 7.5254 8.8884 sd 0.54461 0.52802 0.62216 a&c 0.00 h.s se 0.17222 0.16697 0.19674 min. 6.20 6.84 7.95 b&c 0.00 h.s max. 7.90 8.71 9.78 transverse flexural strength: descriptive data of mean, standard deviation, standard error, minimum and maximum and also the anova test and lsd test are listed in table (3). table (3): descriptive data and lsd test of transverse flexural strength test a 0% b 1% c 1.5% anova ftest sig. groups p-value sig. n 10 10 10 5.740 0.008 h.s a&b 0.03 s mean 111.5800 120.9400 125.3630 sd 10.24053 10.05454 7.11225 b&c 0.00 h.s se 3.23834 3.17952 2.24909 min. 96.30 105.80 110.40 a&c 0.31 n.s max. 127.20 135.00 135.20 hardness test: descriptive data of mean, standard deviation, standard error, minimum and maximum and also the anova test and lsd test are listed in table (4). table (4): descriptive data and lsd test of indentation hardness test a 0% b 1% c 1.5% anova ftest sig. groups p-value sig. n 10 10 10 26.970 0.000 h.s a&b 0.00 h.s mean 82.4800 84.8450 86.0050 sd 1.24793 1.10967 0.89519 a&c 0.00 h.s se 0.39463 0.35091 0.28308 min 80.80 83.40 84.40 b&c 0.02 s max 85.10 86.30 87.30 surface roughness test: descriptive data of mean, standard deviation, standard error, minimum and maximum and also the anova test and lsd test are listed in table (5). table (5): descriptive data and lsd test of surface roughness test a 0% b 1% c 1.5% anova f-test sig. groups p-value sig. n 10 10 10 2.122 0.139 n.s a&b 0.64 n.s mean 1.5435 1.6181 1.8621 sd 0.27362 0.33790 0.45109 a&c 0.59 n.s se 0.08653 0.10685 0.14265 min 1.19 1.02 1.08 b&c 0.14 n.s max 2.01 1.97 2.53 water sorption test: descriptive data of mean, standard deviation, standard error, minimum and maximum and also the anova test and lsd test are listed in table (6). j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 41 table (6): descriptive data of water sorption test (gm/cm2) and lsd test a 0% b 1% c 1.5% anova ftest sig. groups pvalue sig. n 10 10 10 4.414 0.022 s a&b 0.12 n.s mean 0.3888 0.3550 0.3262 sd 0.02919 0.04926 0.05503 a&c 0.00 h.s se 0.00923 0.01558 0.01659 min 0.34 0.23 0.23 b&c 0.18 n.s max 0.43 0.40 0.40 water solubility test descriptive data of mean, standard deviation, standard error, minimum and maximum and also the anova test and lsd test are listed in table (7). table (7): descriptive data of water solubility test (gm/cm2) and lsd test a 0% b 1% c 1.5% anova f-test sig. groups p-value sig. n 10 10 10 4.648 0.018 s a&b 0.077 n.s mean 0.0138 0.0095 0.0076 sd 0.00285 0.00617 0.00337 a&c 0.005 h.s se 0.00090 0.00195 0.00106 min 0.01 0.00 0.00 b&c 0.245 n.s max 0.02 0.02 0.01 scanning electron microscope test (sem) test: particle size of nano particles was evaluated by sem test, the results showed that the nanoparticles have spherical shape and with particles size < 100 nano as seen in figure (5). the fracture surface of 1.5%wt sample of impact strength test specimen was examined by sem with different magnifications power to evaluate dispersions of nanoparticles in the resin matrix as seen in figure (6). figure (5): sem of nano zrsio4 to determine figure (6): sem of pmma/zrsio4 nanofiller dispersion of the particle size discussion the results of the present study indicate that there was highly significant increased in impact strength when zirconium silicate nano was added to pmma. this is because the new compound (zrsio4+pmma), potentiate the internal resistance due to force exchange between filler and matrix. moreover, particle size and bonding interaction significantly affect the compound stress-strain behavior. also forces applied are moved to the nanoparticles which increases the impact strength(20,21), this result was in agreement with safi(22) who incorporated zro2 nano fillers into heat cured (pmma). the increase in transverse strength after addition of nanoparticles lead to reduce free space distance between polymer chains and lead to filling free spaces between chains and attract resin molecules and hence polymer chains during curing process creating more complicated network chains(23,24). this result was in accord with jasim(25) who incorporated silanized alumina nanofiller into conventional heat cured (pmma). the increased in hardness of nano composite can be explained with several factors; it may be attributed to the inherent hardness characteristic of the zrsio4 nano particles,the zirconium silicate has tetragonal crystal structure seems like j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 42 small prism shaped structure separated or may appear as double pyramids connected from the bottom given the very hard and heavy properties(26). another factor of increase in hardness may be due to good distribution in the resin matrix (27). this result was in agreement with alnamel(28) who found that there was a highly significant increase in surface hardness when sio2 was added to heat cure acrylic resin with different percentages (3%, 5% and 7%). the results showed non-significant increase in surface roughness when different percentages (1% wt and 1.5% wt) of silanized zrsio4 nanoparticles were added, this may be due to that the surface roughness test is concerned with outer surface and not with inner surface of composite and because of using zirconium silicate nanoparticles which is very small size <100 nano and well dispersed in the resin matrix moreover, because of small percentage of nano-zrsio4 particles were added to acrylic resin so only very small amount of nanoparticles concerned on the surface(29). the result was in agreement with jasim, (2014), who concluded that the surface roughness was not changed when silanized al2o3 nanoparticles added to pmma. zrsio4 nano filler has the property of insoluble in water (30). when it was incorporated into pmma resin matrix lead to decreasing in diffusivity of the water molecule which reduces water sorption and decrease in water uptake(31). the decreasing in water solubility can be explained by that micro voids or pores can be formed during curing of acrylic resin. therefore, when the amount of pores found in polymer are increases may result in more fluid gain through it which causes molecules to be separated that leads to more absorption of fluids. zirconium silicate nanofiller which is insoluble material might decrease the total amount of polymer absorption(30). the results of water sorption and solubility were coincides with mohammed(32), who found noticeable reduction in water sorption and solubility when zro2 nano fillers were incorporated into conventional heat cured (pmma). references 1cheng yy, cheung wl, chow tw. strain analysis of maxillary complete denture with threedimensional finite element method. j prosthet dent 2010; 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modified zirconium oxide nano-fillers addition on some properties of heat cure acrylic denture base material. j bagh coll dentistry 2012; 24(4): 1–7. j bagh college dentistry vol. 29(3), september 2017 comparison among restorative dentistry 9 comparison among pulp capping materials in: calcium ion release, ph change, solubility and water sorption(an in vitro study) dr. nagham a. al-hyali, b.d.s., m.sc.(1) abstract background: calcium hydroxide and calcium-silicate materials used as direct pulp capping materials. the aims of this in vitro study is to compare among these materials in, the calcium ion release and ph change in soaking water after immersion of materials’ specimens in deionized water. also solubility and water sorption of materials’ specimens measured after soaking time. calcium-silicate materials used were biodentine, theracal and mta plus. materials and methods: four materials used in this study; urbical lining (as control group), biodentine, theracal and mta plus. ten discs fabricated from each tested material, by using plastic moulds of 9 mm diameter and 1 mm thickness. each specimen was immersed in 10 ml of deionized water and stored at 37ºc using incubator for 3 hr, 24hr, 14 days and 30 days as a sequence. the amount of calcium ion (ca+2) released in soaking water was measured in each tube using atomic absorption spectrophotometer. also ph analysis for soaking water measured by using ph meter. for solubility and water sorption measurement, the specimen (n=10) weighed with precision weighing scale before immersion in deionzed water to determine the initial weight (w1) and immediately after weighing immersed in 10 ml of deionized water at 37 °c for 1 week using an incubator, then removed and weighing again (w2). the samples blotted dry using filter paper and dehydrated in an oven at 37 °c for 24 hr and weighed again (w3). then percentage of solubility and water sorption were determined. the obtained data were analysed using one-way anova and tukey tests at 0.05 significant levels. results: statistical analysis showed highly significant differences (p<0. 05) among tested materials and in all tests (ca+2 release, ph change, solubility and water sorption). biodentine showed higher calcium ion released at four soaking time, with non significant difference with theracal and highly significant difference with mta plus and control group at 24 hr. immersion time; while mta plus showed non significant difference with control group at 24 hr. less amount of calcium released was in control group. all tested materials induced alkalization of the soaking water that decreased with time. means of solubility and water sorption showed that mta plus and biodentine had higher solubility in comparison with control group, while theracal showed less solubility than control group. the results of water sorption showed that less sorption percentage occurred in control group in comparison with other groups. conclusion: calcium-silicate materials released more ca+2 with time than calcium hydroxide. theracal showed less solubility and higher water sorption in comparison with control group. biodentine and mta plus showed higher solubility and water sorption in comparison with theracal and control group. keywards: calcium-silicate materials, calcium hydroxide, solubility, calcium ion and ph. (j bagh coll dentistry 2017; 29(3):9-16) introduction the procedure of pulp capping relies primarily on the ability of pulpal tissue to heal. various factors affect this process including age, periodontal condition and stage of root formation. procedural factors such as: size of exposure, its nature (traumatic, mechanical or carious) and microbial contamination of the site have also been described as determinants of the success of pulp capping. however, the importance of these factors has been challenged. wide arrays of materials have been used for pulp capping, but calcium hydroxide remains the standard (1). for many decades' calcium hydroxide has been the standard material for maintaining pulp vitality, used in a direct and indirect pulp capping, because it's capable of stimulating the formation of tertiary dentin by the pulp, which seals exposures by newly formed hard tissue (2).nevertheless, calcium hydroxide has some drawbacks such as poor bonding to dentin, material resorption and (1) lecturer, conservative department, college of dentistry, baghdad university. mechanical prevent microleakage in term, because instability, so thatit does not of the porosities (tunnel defects) of the newly formed hard tissue, which may act as a portal of entry for microorganisms. these may cause secondary inflammation of the pulp tissue and thought to be responsible for failed maintenance of tooth vitality. in addition, the high ph (approximately 12.5-12.8) of calcium hydroxide suspensions causes liquefaction necrosis at the surface of the pulp tissue (3, 4). the bioactivity of pulp capping agents was often associated with ability to release hydroxyl and calcium ion (ca+2) (4). hydroxyl ion (oh-) provides an antimicrobial effect by formation alkaline media (higher ph) that create an adverse environment for bacterial survival and proliferation (5,6), and causes pulpal necrosis that triggers tissue repair and prompts the release of proteoglycans, metalloproteinases and growth factors from the mineralized dentine matrix. oh ion can signal pulpal undifferentiated cells to migrate to the injury site, proliferate and differentiate into odontoblasts like cells to secrete organic extracellular matrix and initiate mineralization (7). ca+2ion is also necessary for j bagh college dentistry vol. 29(3), september 2017 comparison among restorative dentistry 10 differentiation and mineralization of pulp cells (8) by reducing capillary permeability and in turn reducing, the serum flow and the levels of inhibitory pyrophosphates that causes mineralization (9). in addition, the eluted ca+2 ion increases the proliferation of human dental pulp cells in dose dependent manner (10,11) and activates pyrophosphatase which helps to maintain dentine mineralization and the formation of a dentine bridge (12). bioactive materials have been used in every field of dentistry and medicine. these materials are broadly used in the field of conservative dentistry and available in different form and composition that acts directly on vital tissue inducing its healing and repair induction of various growth factors and different cells. bioactive materials (calcium silicate– containing materials), including mineral trioxide aggregate (mta), biodentine and theracal lc are new material that have numerous applications, such as direct pulp capping. interestingly, calcium hydroxide are formed during their setting reaction, which impart with antibacterial and regenerative properties. for this reason, bioactive materials and calcium hydroxide are thought to share a similar mechanism of action (13). however, studies showed less inflammation, better dentin bridging, hydroxyl apatite formation, and minimal cytotoxicity with bioactive materials (14, 15). water sorption and solubility are important physical properties of pulp capping material because degradation of the cement and lining materials, leads to debonding of the restoration and recurrent decay (16). however, most of tests are static solubility tests, unrelated to the conditions found in the oral environment and applied only to short-term solubility, while some investigators studied the solubility in dynamic state (different ph) (17,18). the aim of this in vitro study is first to compare between calcium hydroxide and calciumsilicate containing dental materials in: calcium ion released in deionized water, solubility, water sorption and whether their ph alters with time. materials and methods four types of pulp capping materials (table 1) used in this study (four groups), the powder / liquid ratio and mixing of the components of each material was carried according to manufacturer instructions as follow: control group (calcium hydroxide group): urbical lining consist of two pastes mixed in a 1:1 weight proportion. mta plus group: mineral trioxide aggregate material consist of powder and liquid, manipulated by mixing of 3 parts of powder with 1 part of liquid to obtain putty like consistency, setting time for mta about 55 min (19). biodentine group: biodentine consist of powder and liquid. the powder was mixed with 5 drops of liquid in a capsule using a triturator (ydm, hangzhou yin ya new materials co. ltd, china) for 30 seconds, setting time about 12 to 15 minutes (20). theracal group: theracal its light curing material, in this study cured by light emitted diode led (latte, china) with light intensity 700mw/cm2. duration of light curing about 20 seconds for each layer which should not exceed 1mm in depth (21). specimens’ construction fabrication of ten disc-shaped specimens from each tested material (table 1), by using plastic moulds of 9 mm diameter and 1 mm thickness. preweighed dental floss was embedded in the discs during fabrication to assist in handling of the samples. for fabrication of each specimen, the mould filled with the tested material which mixed according to manufacturers’ instructions, in a room with climate-controlled conditions (50±10% humidity and 23±2ºc), then the filled mould was covered with a polyester strip and a glass plate (figure 1), maintained under pressure until complete setting of chemical set materials, while light cure theracal lc did not need pressure (22, 23). after construction of specimens, each specimen immersed in separated plastic tube containing 10 ml of deionized water for 3hr, 24hr, 14 days and 30 days as a sequence. at each immersion time, the soaking water subjected to the following testing: ph analysis and testing of calcium ions released. solubility and water sorption percentage were measured for each material after immersion time 7 days. testing of solubility and water sorption the american dental association’s specification #8 (zinc phosphate cement solubility) was adopted with a few small modifications to design the methodology used in this study, the solubility tests used deionized water rather than oral fluids for immersion of specimens (4, 23). the sample (n=10 for each tested materials) weighed with precision weighing scale (professional digital table top scale, china) (figure1), before immersion in water to determine the initial weight (w1) and immediately weighing after immersed vertically by using dental floss, in 10 ml of deionized water in individually plastic tube at 37 °c for 1 week in an incubator (memmert, germany), then saturated sample removed and weighing again (w2). the samples then blotted dry using filter paper, dehydrated in j bagh college dentistry vol. 29(3), september 2017 comparison among restorative dentistry 11 an oven at 37 °c for 24 hr, and weighed again (w3). the loss of material (solubility) was obtained from the difference between the initial and the final drying mass (w1w3) of each disc, discounting the mass of the dental floss. each weight (in µg/mm3) measurement was repeated three times. the percentage of solubility and water sorption were determined as follows (15, 24): % solubility= [(w1– w3)/ w3] 100% %water sorption= [(w2– w3)/ w3]100% w1: the initial weight of sample w2: sample saturated with water w3: the final weight of sample after dehydration testing of calcium ions release and ph analysis each disc-shaped specimen was immersed in 10 ml of deionized water and stored at 37ºc using incubator (memmert, germany) for 3 hr, 24hr, 14 days and 30 days. the specimens removed from tube after tested times and amount of calcium ions released in soaking water was measured (in ppm) in each tube using atomic absorption spectrophotometer (25) (ice 3300, thermo scientific, usa) and ph of each solution measured using ph meter (hanna instruments, ph microprocessor ph meter and hi 1332 ph probe, china). statistical analysis was performed with spss software package (version 20.0). data of each test collected and analyzed using analysis of variance test (one-way anova) and tukey test to find any significance difference between the groups. mean difference is significant at the 0.05 level. table (1): types of materials used in the study, types of activation, manufacturer and batch number. materials composition activation manufacturer and batch # urbical lining (calcium hydroxide) base paste: ester glycol salicylate, zinc oxide, calcium phosphate, calcium tungstate pigments catalyst paste: calcium hydroxide 26%, n-ethyl toluene sulphonamide, zinc oxide, titanium dioxide, zinc stearate, calcium wolframate, salicylate. chemical promedica, dental material gmbh, domagkstra, neumunster, germany. batch#: 2441 mta plus (mineral trioxide aggregate) powder: tricalcium silicate (cao)3 · sio2dicalcium silicate (cao)2 · sio2tricalcium aluminate (cao)3· al2o3bismuth oxide bi2o3, gypsum caso4 ·2 h2o liquid: distilled water h2o chemical pph cerkamed company, kwiat kow skiego, stalowawola, polska batch #: 1809141 biodentinetm powder: tricalcium silicate ca3sio5 (>70%) dicalcium silicate ca2sio4 (<15%) zirconium oxide zro2 (5%) calcium carbonate caco3 (>10%) as filler iron oxides (<1%) liquid water h2o, calcium chloride cacl2 (>15%) as accelerator, hydro soluble polymer (polycarboxylate), water reducing agent chemical septodont, saint maurdes, fosses, france. batch#: b14835 theracal lc paste: 45%wt mineral material (type iii portland cement), 10%wt radiopaque component, 5%wt hydrophilic thickening agent (fumed silica), 45%metacrylic resin physical (light) bisco, irving park rd. schaumburg, u.s.a. batch #: 1500000915 j bagh college dentistry vol. 29(3), september 2017 comparison among restorative dentistry 12 figure 1: some of equipment and instruments used in this study results table 2 summarizes ca+2 ion released means and standard deviations for tested materials, the results showed that all tested materials released ca+2 ion in soaking time and the released decreased with time, with the exception of biodentine at 30 days, the mount released more than at 14 days. all calcium silicate-containing materials released more ca+2 ion than ca(oh)2 material (table 2), except mta plus at 14 and 30 days. one way anova showed highly significant differences among the groups in alkalization effect on soaking water. all materials induced alkalization of the soaking water that decreased with time (table 2). one way anova and tukey test showed highly significant differences among the groups in ca+2 ion released (table 4). higher solubility occurred in mta plus followed by biodentine, urbical and less percentage occurred with theracal (table 3). the results of water sorption test, showed highly significant differences among the groups with higher percentage of sorption occurred in mta plus group followed by, biodentine, theracal and less percentage occurred with urbical (table 3, 5). discussion the ability to release calcium and hydroxyl ions is a key factor for successful pulp capping therapy because of calcium’s action on pulp cell differentiation and hard tissue mineralization (26). the therapeutic effect of calcium hydroxide materials is due to its ability to break down into calcium and hydroxyl ions. hydroxyl ion show an affinity to various biologically active substances such as microbes causes endodontic diseases (27). their antimicrobial activity is formation of potent alkaline medium leading to the destruction of lipids, which are the main component of bacterial cell membrane and causing structural damage to bacterial proteins and nucleic acids (28). chemically, calcium hydroxideis classified as a strong base with high ph. although some studies have confirmed its efficacy against endodontic bacteria, other studies have questioned its effectiveness (29). in this study calcium hydroxide compared with calcium silicate materials including, mta plus, biodentine and theracal in calcium ion release, because these materials formed calcium hydroxide during their setting reaction (30). mineral trioxide aggregate introduced by torabinejad in 1993 (31). it's a bioactive material has a common characteristic of apatite formation (19). this is a material of choice for vital pulp therapy, apexification, apexogenesis, correcting procedural errors as well as for root-end filling material in apicoectomy procedures (13). the exact mechanism of dentinal bridge formation when mta is used is not known completely. however, it was found that when mta was used as a pulp capping agent it induces cytologic and functional changes within pulpal cells, resulting in formation of fibro dentine and reparative dentin at the surface of mechanically exposed dental pulp, its causes proliferation, migration and differentiation of odontoblast-like cells that produce a collagen matrix. this formed mineralized matrix by osteodentin initially and then by tertiary dentin formation (19). biodentine with active biosilicate technology announced by dental material manufacturer septodent in september of 2010, and made available in january of 2011. biodentine is a calcium silicate based material having similar properties of dentin and has a positive effect on vital pulp cells stimulating tertiary dentin formation (32), used for the treatment of root perforation or for the pulpal floor, internal and external resorption, apexification, retrograde root canal obturation, pulpotomy and also for temporary sealing of cavities and cervical filling (33). septodent claimed that biodentine is not mutagenic (34) and can resist microleakage in comparison with mta (35). theracal it is a light cured resin modified calcium silicate filled liner used for insulating and protecting dentin-pulp complex in a direct and indirect pulp capping, and as a protective base/liner under composites, amalgams, cements and other base materials (21). theracal has the ability to form hydroxyl apatite when immersed in a phosphate-containing solution (36) with lowest cytopathic effects (14).in this in vitro study, calcium silicate groups showed highly significant differences in comparison with control group (p<0.001). biodentine demonstrated higher alkalinizing capability and calcium ion than other groups at all soaking time (3 h, 24 h, 14 days and 30 days), the j bagh college dentistry vol. 29(3), september 2017 comparison among restorative dentistry 13 ca+2 ions and ph of soaking waterdecrease with time and ph range from (11.06-9.17) with highly significant differences among subgroups of biodentine. these results agreed with gandolfi m. et al., 2013(15) and gandolfi m. et al., 2014 (37). tukey test revealed highly significant differences among subgroups of materials, except between control and mta plus groups, and between biodentine and theracal groups at 24 hr. immersion time, the results were non-significant differences. the high ca+2 ion released of biodentine can be correlated with the presence of calcium silicate component and calcium chloride (15). mta plus similar to biodentine in composition, the results showed higher ca+2release and higher ph (11.65-8.21) in comparison with theracal and control group. the calcium ion release and alkalizing decrease with time. these results agreed with gandolfi m. et al., 2013 (15) and gandolfi m. et al., 2014 (37), but disagree with gandolfi m.g. et al., 2012 (21) who showed that theracal release moreca+2 ions in comparison with dycal and proroot mta. calcium silicate materials leached large amounts of ca+2 and ohions (high ph) because, the hydration reaction of the calcium silicate particles triggers the dissolution of their surface with the formation of a calcium silicate hydrate gel and ca(oh)2, together with the release of ca +2 and oh(15), which impart them with antibacterial and regenerative properties (13, 38). bioactive materials were used in contact with periapical bone tissue or with vital pulp. for this reason, they should possess specific bio-properties like biocompatibility, bio-interactivity (release of biologically relevant ions), and bioactivity (apatite-forming ability) in order to promote the activity of mineralizing cells and the formation of new periapical bone or reparative dentine (15). all tested materials caused alkaline soaking water and alkalinity decreased with time. the elevated ph of calcium hydroxide and calcium silicate materials activated alkaline phosphatise which was hydrolytic enzyme that acted by liberation of inorganic phosphate from the esters of phosphate, it’s important for process of mineralization (38, 39). the best ph for activation of this enzyme ranged from (8.6 to 10.3) (40, 41). this enzyme can separate the phosphoric esters, freeing phosphate ions, which once free react with ca+2 ion from the blood stream to form a precipitate calcium phosphate in the organic matrix. this precipitate is the molecular unit of hydroxyl apatite (15). ion release depends on the nature of the mineral particles and on the network structure of the cement responsible for water sorption and solubility as well as the permeability of the material to water diffusion (porosity) (37). calcium release and ph were measuredin deionized water rather than simulated body fluid in order to standardize the test conditions and hence allow a comparison of the data with other future studies (15). solubility test found that calcium hydroxide had less solubility (6.45%) than biodentine and mta plus, but more solubility than theracal, with highly significant differences among the groups. while water sorption of control group was less than other groups.biodentine showed less solubility (13.05%) and water sorption (16.3%) in comparison with mta plus (solubility (19.35%) and water sorption (26.48%), correlated with the restricted amount of dispersing waterreducer super plasticizing mixing fluid likely based on polycarboxylic ether. these results in agreement with gandolfi et al, 2014 (37), but disagree with gandolfi etal., 2013 (15) who found that biodentine had lower watersorption than proroot mta while the solubility values for proroot mta lower than biodentine. biodentine and mta plus were prepared by mixing the mineral powder with water-based liquid using very different liquid/powder weight proportions for each material. the liquid susceptible to evaporation in the drying procedure needed for the solubility test to obtain the final dry mass. the hydration of calcium silicate cements proceeds by converting liquid into structural and constrained water. this process occurs mainly in the first few days, moreover the leaching of water-soluble components causes' weight loss. this means that the reduction of the original weight obtained in the dry mass will not be entirely due to the solubility of the material, because much of the weight loss is caused by evaporation of the mixing free water during the final drying of the samples. all this must be taken in consideration when collecting the data of solubility (15).it was reported in previous studies that long–time storage of dental cements in water affected the mechanical properties of the cements (42, 43). cattani-lorente et al (44) found that deterioration of the physical properties of the cements after 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torabinejad m. sealing ability of a mineral trioxide aggregate for repair of lateral root perforations. j endod 1993; 19: 541–4. 32.santos ad, moraes jc, araujo eb, yukimitu k, valeriofilho wv. physio-chemical properties of mta and a novel experimental cement. int endod j 2005; 38: 443-7. 33.dammaschke t, leidinger j, schäfer e. long-term evaluation of direct pulp capping-treatment outcomes over an average period of 6.1 years. clin.oral investig.2010; 14: 559-67. 34.laurent p, camps j, de mm, dejou j, about i. induction of specific cell responses to a ca3sio5 based posterior restorative material. dent. mater. 2008; 24 (11): 1486-1494. j bagh college dentistry vol. 29(3), september 2017 comparison among restorative dentistry 15 35.tran v, pran v, colon p. microleakage of new restorative calcium (biodentine) oral presentation, mentioned in "biodentine publications and communication 2005-2010, by septodent. dec. 2012: 64. 36.gandolf mg, siboni f, taddei, modena p, prati c. apatite-forming 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of water storage on the mechanical properties of zinc polycarboxylate cements. digest j. of nano materials and bio structures 2007; 2(2): 243-52. 43.tuna sh and, keyf f. water sorption and solubility of provisional and permanent luting cement. hacettepe dishekimligi fakultesi dergisi 2006; 30(3): 19-24. 44.cattani-lorente ma, dupuis v, payan j, moya f, meyer jm. effect of water on the physical properties resin modified glass ionomer cements. dent mat 1999; 15: 7179. table (2): descriptive statistic for ph analysis and calcium ions released with one-way anova test among the subgroups of each group. groups (n=10) times ph analysis calcium ions released mean s.d. f-test pvalue sig. mean s.d. f-test p-value sig. control 3 hr. 10.25 0.18 138.246 0.000 hs 33.94 3.81 83.257 0.000 hs 24 hr. 10.43 0.08 26.42 3.94 14 days 9.57 0.03 15.77 2.15 30 days 9.74 0.06 14.21 2.63 biodentine 3 hr. 11.06 0.27 97.984 0.000 hs 92.73 2.10 2218.629 0.000 hs 24 hr. 11.63 0.25 35.19 1.47 14 days 9.41 0.60 28.67 1.56 30 days 9.17 0.30 34.03 2.71 mta 3 hr. 11.65 0.26 296.100 0.000 hs 46.48 2.91 609.521 0.000 hs 24 hr. 11.42 0.16 26.23 1.22 14 days 8.37 0.46 11.43 1.16 30 days 8.21 0.403 8.82 1.12 theracal 3 hr. 10.60 0.87 29.379 0.000 hs 63.28 2.57 815.388 0.000 hs 24 hr. 8.87 0.43 36.67 2.81 14 days 8.67 0.33 22.91 2.10 30 days 7.97 0.49 17.82 1.18 p > 0.05: non significant (ns), p < 0. 05: significant (s), p≤ 0.01: highly differences (hs) table (3): descriptive statistic of solubility and water sorption tests, and comparison among the groups using one-way anova. groups (n=10) solubility test water sorption test descriptive statistic comparison descriptive statistic comparison mean s.d. f-test pvalue mean s.d. f-test pvalue control 6.45 0.36 966.503 0.000 hs 6.03 0.44 1922.701 0.000 hs biodentine 13.05 0.88 16.301 0.87 mta 19.35 0.93 26.48 0.38 theracal 3.59 0.51 11.53 0.66 j bagh college dentistry vol. 29(3), september 2017 comparison among restorative dentistry 16 table (4): tukey test and one-way anova for comparison among the tested materials in calcium ions released (in ppm) at each immersion time. tukey test one-way anova times comparison among the groups mean difference p-value sig. f-test p-value sig. 3hr control biodentine -58.79 0.000 hs 759.147 0.000 hs mta -12.54 0.000 hs theracal -29.34 0.000 hs biodentine mta 46.25 0.000 hs theracal 29.45 0.000 hs mta theracal -16.80 0.000 hs 24hr control biodentine -8.77 0.000 hs 45.944 0.000 hs mta 0.19 0.998 ns theracal -10.25 0.000 hs biodentine mta 8.96 0.000 hs theracal -1.48 0.587 ns mta theracal -10.44 0.000 hs 14 days control biodentine -12.90 0.000 hs 181.010 0.000 hs mta 4.34 0.000 hs theracal -7.14 0.000 hs biodentine mta 17.24 0.000 hs theracal 5.76 0.000 hs mta theracal -11.48 0.000 hs 30 days control biodentine -19.82 0.000 hs 277.150 0.000 hs mta 5.39 0.000 hs theracal -3.61 0.002 hs biodentine mta 25.21 0.000 hs theracal 16.21 0.000 hs mta theracal -9.00 0.000 hs table (5): tukey test for comparison among the tested materials in solubility and water sorption. tukeytest comparison among the groups for solubility for water sorption mean difference p-value sig. mean difference p-value sig. control biodentine -6.59 0.000 hs -10.26 0.000 hs mta -12.89 0.000 hs -20.45 0.000 hs theracal 2.86 0.000 hs -5.50 0.000 hs biodentine mta -6.30 0.000 hs -10.18 0.000 hs theracal 9.46 0.000 hs 4.76 0.000 hs mta theracal 15.76 0.000 hs 14.95 0.000 hs الخالصة المقدمة: قامت هذه الدراسة من اجل المقارنة بين هيدروكسيد الكالسيوم وسيليكات الكالسيوم في تحرير ايونات الكالسيوم وتغيير درجة حموضة الماء وقياس ذوبان وامتصاص الماء. من كل نوع عيناتوثريكال.عشرة )مجموعة السيطرة( , بايودنتين, ام تي اي بالس الكالسيوم هذا البحث هي: هيدوكسيدمستعملة في المواد ال المواد والطريقة المستعملة في البحث: 02عة, سا 42ساعات, 7درجة سليليزية باستعمال الحاضنة لمدة 73مل من الماء منزوع األيونات ويتم حفظها في درجة حرارة 01ثم تغمر فيتصنع باستعمال قوالب بالستيكية هاز قياس الحامضية. بعد يوم. كمية ايونات الكالسيوم المحررة في ماء الغمر تقاس باستعمال مطياف االمتصاص الذري. أيضا درجة حموضة ماء الغمر تقاس باستعمال ج 71يوم و ( tukey test)واختبار الفرق المعنوي (anova) ال اختبار تحليل التباينتحلل البيانات الناتجة إحصائيا باستعم. ذلك تخضع العينات لنسبة درجة الذوبان ونسبة امتصاص الماء اظهر اختبار . فيمانسبة في تحرير أيونات الكالسيوم وفي جميع األوقات أعلىبين المواد وفي جميع االختبارات. أظهر بايودنتين ظهر التحليل اإلحصائي وجود فروقا معنويةأ النتائج: االم تي اي بالس كانا أعلى ذوبان بالمقارنة مع مجموعة السيطرة، وأظهرت ن البايودنتين وأبة الماء مع الوقت. وأظهرت نتائج الذوبان وامتصاص الماء حموضة الماء نقصان قلوي .نتائج امتصاص الماء بان أقل نسبة امتصاص وقعت في مجموعة السيطرة بالمقارنة مع المجموعات األخرى وبان من بقية المواد وامتصاص قل نسبة ذسيليكات الكالسيوم تحرر ايونات كالسيوم أكثر وتقل الكمية مع الوقت. أما بالنسبة لقلوية الماء فإنها تقل مع الوقت. الثريكال لديه أ االستنتاج : .ومجموعة السيطرة نسبة ذوبان وامتصاص من الثريكال أعلىاقل من مجموعة السيطرة. البايودنتين واالم تي اي بالس اظهرا j bagh college dentistry vol. 29(4), december 2017 comparison of periodontal oral and maxillofacial surgery and periodontics 72 comparison of periodontal health status in relation to iq in rightand left handed individuals nada k. imran, b.d.s., msc. (1) abstract background: periodontal disease (pd) is a chronic inflammatory condition characterized by destruction of supporting structures of the teeth. intelligence quotient (iq) was potentially reported to significantly associated with prevalence of gingivitis. mild gingivitis was obtained in high iq levels while moderate gingivitis may be attributed to poor oral hygiene seen among the subjects having low iq levels. method: one hundred volunteers aged between 20-45 years old were enrolled in this study, patients were equally divided into rightand left-handed (50 patients each)and each group then subdivided into patients with healthy gingiva(10), patients with gingivitis (20), and patients suffering from periodontitis (20).an iq questionnaire was prepared to be answered by each patient, periodontal health status was recorded by using clinical periodontal parameters, plaque index (pli)and gingival index (gi). results: analysis of data showed that there is no significant difference in parameters measured in the same group. results of iq score among healthy, gingivitis and periodontitis groups indicated presence of significant difference (p≤0.001) between rightand left-handed as compare to healthy subjects, furthermore, in left-handed patients, iq score was significantly higher (p≤0.05) in gingivitis group in comparison to periodontitis patients. in contrast, same groups in right-handed patients showed almost the same iq score. the same pattern was observed in association with plaque index. conclusion: left-handed individuals have higher potential in providing plaque control. however, iq score did not affect oral hygiene level with increased severity of periodontal disease in both groups. (j bagh coll dentistry 2017; 29(4): 72-75) introduction dental biofilm is well-recognized for its role in the initiation and progression of periodontal disease (1). traditional periodontal treatment consists of professional removal of dental plaque and its retentive factor which should be followed by personal oral hygiene measure to ensure success of the treatment (2). tooth brushing is the most effective, easiest, and cheapest method for eliminating and controlling formation of dental biofilm and hence preventing and reducing severity of periodontal diseases (3). however, effectiveness of tooth brushing is variable among subjects due to several factors some are related to the quality of toothbrush itself, other factors are associated with individuals themselves such as manual dexterity, duration, frequency, and motivation (4, 5). nevertheless, correct brushing method is the key factor in achieving good plaque control (6). some researches debate about outcome of brushing between rightand left-handed individuals and their ability to mechanically remove dental plaque (7, 8). comparison of oral health status between rightand left-handed individuals showed that left-handed individuals have better oral hygiene as compared to right-handed group (9). intelligence quotient (iq) can be defined as “relative intelligence of an individual expressed as a score on a standardized test of intelligence” (10). iq could represent another potential factor that affect the level of oral hygiene (10, 11). (1)assistant lecturer, department of periodontics, college of dentistry, university of baghdad. left-handedness is more common in distinct individuals such as mathematicians, musicians, and architects (12, 13). this may suggest higher iq in comparison to right-handed individuals (13, 14). increase iq level potentially increase awareness and understanding of the nature of periodontal disease. in addition, this could improve perception of motivation and execution oral hygiene instruction delivered by the dentist which may result in better oral health status. thus, the aim of current study is to evaluate oral hygiene and gingival health in right and left-handed individuals in relation to iq among periodontallydiseased patient in comparison to healthy individuals materials and methods study design: one hundred volunteers aged between 20-45 years old were enrolled in this study. they were recruited from patients attending the clinics of college of dentistry/baghdad university. a signed consent was obtained from the patients participated in this study, after explaining to them the nature of the research. patients were equally divided into rightand left-handed (50 patients each) and each group then subdivided into patients with healthy gingiva (10), 20 patients with gingivitis, and 20 patients suffering from periodontitis. an iq questionnaire was prepared to be answered by each patient which includes ability test and diagramed test. j bagh college dentistry vol. 29(4), december 2017 comparison of periodontal oral and maxillofacial surgery and periodontics 73 exclusion criteria: the following were excluded from the study: 1. history of any systemic diseases. 2. history of antibiotic taking within the previous three months. 3. history of periodontal treatment during the last three months. 4. smokers. 5. pregnant females. 6. female under contraceptive pills. clinical periodontal indices: periodontal health status was recorded by using clinical periodontal parameters, plaque index (pli), gingival index (gi), was performed by using michigan o probe. statistical analysis analysis of results was performed by utilizing statistical package of social science (spss). comparison of multiple groups was assessed by one way-anova test followed by tukey’s posthoc test to calculate difference within groups. statistical difference was considered significant when p≤0.05. results this study was conducted to investigate the relation between periodontal health status of right and left handed (healthy, gingivitis, and periodontitis patients) to their iq score. analysis of data showed that there is no significant difference in parameters measured in the same group. however, gingivitis group showed significant difference (p≤0.05) between rightand left-handed patient in association with iq score and pi (table 1). table 1: comparison of iq, pli, and gi between rightand left-handed groups iq score pvalue righthanded left-handed healthy±sd 86.47±9.22 84.11±10.39 ns gingivitis±sd 44.99±16.46 66.17±18.49 ≤0.05 periodontitis± sd 47.05±14.15 53.33±16.16 ns plaque index p-value righthanded left-handed healthy±sd 0.28±0.05 0.23±0.03 ns gingivitis±sd 1.03±0.15 0.77±0.19 ≤0.05 periodontitis± sd 1.44±0.24 1.38±0.12 ns gingival index p-value righthanded left-handed healthy±sd 0.19±0.03 0.17±0.02 ns gingivitis±sd 0.97±0.11 0.88±0.15 ns periodontitis± sd 1.13±0.17 1.07±0.12 ns results of iq score among healthy, gingivitis and periodontitis groups indicated presence of significant difference (p≤0.001) when compared rightand left-handed healthy subjects (fig 1). furthermore, in left-handed patients, iq score was significantly higher (p≤0.05) in gingivitis group in comparison to periodontitis patients. in contrast, same groups in right-handed patients showed almost the same iq score (fig 1). the same pattern was observed in association with plaque index (fig 2) were healthy subjects, both right and left-handed, subjects showed significantly lower (p≤0.001) plaque scores in comparison to gingivitis and periodontitis patients. in addition, plaque index scores in periodontitis group, both rightand left-handed, was significantly higher that gingivitis patients (fig 2). rightand lefthanded patients, in gingivitis and periodontitis groups, showed significantly (p≤0.001) higher gingival index score when compared to their healthy counterparts (fig 3). however, in contrast to previously observed findings in association with plaque index, no significant difference was indicated in gingival index between rightand left-handedpatients of periodontitis and gingivitis groups. these results in general suggested better periodontal health status associated with increased iq score. in addition, left-handed patients showed higher iq score and better plaque control when compared to right-handed individuals. figure 1: comparison of iq score shows significantly higher difference in iq score of healthy group as compared to gingivitis and periodontitis groups in rightand lefthanded individuals. *=p≤0.05, **=p≤0.001. j bagh college dentistry vol. 29(4), december 2017 comparison of periodontal oral and maxillofacial surgery and periodontics 74 figure 2: comparison of pli shows significantly higher difference in pli of gingivitis and periodontitis groups as compared to healthy group in rightand lefthanded individuals. *=p≤0.05, **=p≤0.001. figure 3: comparison of gi shows significantly higher difference in gi of gingivitis and periodontitis groups as compared to healthy group in rightand lefthanded individuals. *=p≤0.05, **=p≤0.001. discussion nowadays, the relation between accumulation of dental plaque and severity of periodontal diseases is well-recognized (1). severity of periodontal diseases is regulated by many factors such as difference in microflora and genetic susceptibility (15). ability to maintain good oral hygiene is associated by many factors that could affect toothbrushing such as difference in manual dexterity between rightand left-handedness (7, 8) and iq of the person (10). thus, comparison of oral health status between rightand left-handed individuals in relation to their iq was undertaken in the current study. data from this study showed that left-handed individuals have higher iq score in gingivitis group associated with lower pli when compared with right-handedness which is consistent with finding of previous studies (7, 9). the reason behind this could be due to that right-handed individuals usually fail to perform good plaque control right side of the mouth. this finding was reported in previous study which indicated higher plaque accumulation and inflammation in righthanded individuals (16). in contrast, left-handed individuals showed almost equal efficiency to remove dental plaque from both sides of oral cavity with less severity of gingivitis (16). furthermore, motor learning was reported to be better in left-handed individuals associated with higher iq as compared with their right-handed counterparts (14). in addition, pli and gi were significantly higher in gingivitis and periodontitis groups with lower iq, in rightand lefthandedness, in comparison to higher iq-healthy controls. further, gingivitis group showed significantly lower pli associated with higher iq than periodontitis group in left-handed individuals, which indicates better mechanical plaque control. these results were supported by results from previous study that indicated higher motor learning ability in subjects with higher iq than lower iq individuals (14). on the other hand, gi score did not show any difference between the two groups which is not consistent with other studies (14, 16). results of present study showed that healthy and periodontitis group did not show any significant difference between rightand left handedness in all parameters investigated. this could be due to the need for higher sample size for better reveal of any difference exist. in addition, periodontitis represents the terminal stage of periodontal disease resulting mostly from neglected oral hygiene over a long time which could mask any difference in handedness or iq level. preference of handedness is related to many factors including cerebral dominance, neuromuscular functions, and inherited trait (17, 18). this potentially reflected on hand skills in performing oral hygiene measures. this notion is supported by reports from previous studies which indicated that jobs requiring high manual dexterity such as musician and artist are mostly belonging to left-handed group (19, 20), which also demonstrated success in maintaining better oral hygiene than right-handed subjects (21). in general, results of this study suggested that lefthanded individuals have higher potential in providing plaque control. however, iq score did not affect oral hygiene level with increased severity of periodontal disease in both groups. references 1. wade wg. the oral microbiome in health and disease. pharmacological research. 2013; 69:137-43. 2. smiley cj, tracy sl, abt e, michalowicz bs, john mt, gunsolley j, et al. systematic review and metaanalysis on the nonsurgical treatment of chronic periodontitis by means of scaling and root planing j bagh college dentistry vol. 29(4), december 2017 comparison of periodontal oral and maxillofacial surgery and periodontics 75 with or without adjuncts. the journal of the american dental association. 2015; 146:508-24. e5. 3. chapple il, van der weijden f, doerfer c, herrera d, shapira l, polak d, et al. primary prevention of periodontitis: managing gingivitis. journal of clinical periodontology. 2015;42(s16). 4. choi es, jeong s-r, cho h-a. factors affecting the use of oral hygiene devices in adults. journal of dental hygiene science. 2015; 15:775-85. 5. moeintaghavi a, sargolzaie n, rostampour m, sarvari s, kargozar s, gharaei s. comparison of three types of tooth brushes on plaque and gingival indices: a randomized clinical trial. the open dentistry journal. 2017; 11:126. 6. wainwright j, sheiham a. an analysis of methods of toothbrushing recommended by dental associations, toothpaste and toothbrush companies and in dental texts. british dental journal. 2014; 217:e5-e. 7. cicek y, arabacı t, canakcı cf. evaluation of oral malodour in left-and right-handed individuals. laterality: asymmetries of body, brain and cognition. 2010; 15:317-26. 8. çakur b, yıldız m, dane ş, zorba yo. the effect of right or left handedness on caries experience and oral hygiene. journal of neurosciences in rural practice. 2011; 2:40. 9. ozden fo, ongoz f, gunduz k, avsever h. comparison of the oral hygiene status and gingival health between left-and right-handed individuals. journal of experimental and integrative medicine. 2011; 1:197-200. 10. navit s, malhotra g, singh j, naresh v, navit p. interrelationship of intelligence quotient with caries and gingivitis. journal of international oral health: jioh. 2014; 6:56-62. 11. jain m, mathur a, sawla l, choudhary g, kabra k, duraiswamy p, et al. oral health status of mentally disabled subjects in india. journal of oral science. 2009; 51:333-40. 12. adekoya ja, ogunola aa. relationship between lefthandedness and increased intelligence among university undergraduates. 2015. 13. ghayas s, adil a. effect of handedness on intelligence level of students. journal of the indian academy of applied psychology. 2007; 33:85-91. 14. tan ü. right and left hand skill in left-handers: distribution, learning, and relation to nonverbal intelligence. international journal of neuroscience. 1989; 44:235-49. 15. page rc, schroeder he. pathogenesis of inflammatory periodontal disease. a summary of current work. laboratory investigation; a journal of technical methods and pathology. 1976; 34:235-49. 16. addy m, griffiths g, dummer p, kingdom a, shaw w. the distribution of plaque and gingivitis and the influence of toothbrushing hand in a group of south wales 11–12 year‐old children. journal of clinical periodontology. 1987; 14:564-72. 17. mcmanus i, bryden m. the genetics of handedness, cerebral dominance, and lateralization. handbook of neuropsychology. 1992; 6:115-. 18. annett m. annotation: laterality and cerebral dominance. journal of child psychology and psychiatry. 1991; 32:219-32. 19. bever tg, chiarello rj. cerebral dominance in musicians and nonmusicians. science. 1974; 185:5379. 20. mebert cj, michel gf. handedness in artists. neuropsychology of left-handedness. 1980:273-8. 21. tezel a, orbak r, çanakçi v. the effect of right or left-handedness on oral hygiene. international journal of neuroscience. 2001; 109:1-9. tiba f.doc j bagh college dentistry vol. 27(3), september 2015 the influence of restorative dentistry 33 the influence of adding of modified zro2-tio2 nanoparticles on certain physical and mechanical properties of heat polymerized acrylic resin tiba a. salman, b.d.s. (1) hanan a. khalaf, b.d.s., m.sc. (2) abstract background: the mechanical and physical properties of polymethyl methacrylate (pmma) don’tfulfill the entire ideal requirements of denture base materials. the purpose of this study was to produce new modified polymer nanocomposite (pmma /zro2-tio2) andassess itsimpact strength, transverse strength and thermal conductivity in comparison to the conventionalheat polymerized acrylic resin. materials and methods: both zro2 and tio2nano fillers were silanized with tmspm (trimethoxysilyl propyl methacrylate) silane coupling agent before beingdispersed by ultrasonication with the methylmethacrylate (monomer) and mixed with the polymer by means of 2% by weight in (1:1) ratio, 60 specimens were constructed by conventional water bath processing technique and divided into 2 groups: 30 specimens for control group 0% nanofillers and 30 specimens for experimental group 2% of (1:1) zro2 and tio2nano fillers then each group was subdivided into3 subgroups according to the test to be conducted with 10 specimens for impact, transverse and thermal conductivity test. results: the interaction of tmspm silane and the nanofillers was confirmed by ft-ir (fourier transform infra-red spectrophotometer). high significant increase in impact strength (9.838) kj/m2 and transverse strength (101.705) n/mm2 and non-significant increase in thermal conductivity (0.286) w/m.c° of heat cured acrylic resin of the new polymer nanocomposite were observed. conclusions: the addition of 2 wt.% of zro2:tio2 by means of 1:1 ratio considerably improved the impact and transverse strength and had a positive effect on the thermal conductivity. key words: polymethyl methacrylate, nanofillers, polymer nanocomposite. (j bagh coll dentistry 2015; 27(3):33-39). introduction pmma acrylic resin is the most extensively used material for the fabrication of dentures as it possess a combination of favorable characteristics such as easy laboratory manipulation, light weight, inexpensive fabrication, stability in the oral environment, lack of toxicity and appropriate aesthetic and color matching ability (1). however it’s not ideal in every aspect and have several drawbacks that need to be addressed including low impact resistance, fatigue failure, low thermal conductivity which compromises the patients appreciation of taste and palatability (2). many attempts were advocated to overcome these drawbacks and improve the performance of pmma denture base material mainly either by modifying the structure of pmma by copolymerization with rubber (3) or reinforcement by incorporation of different forms and types of fillers like metallic wire (4), fibers (5-7) and the use of metallic oxides (8). with the great development of nanotechnology and nano-phased materials, great attention is directed toward the use of nano –sized fillers to reinforce the denture base resins thus producing a polymer nanocomposite with improved mechani (1)m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2)assist. professor. department of prosthodontics, college of dentistry, university of baghdad. cal and physical properties as compared to those filled with micro-scale particles. furthermore the use of multiple nanofillers rather than single additive develops a high performance composite which cannot be achieved by using single filler (9). the mechanical properties of the resultant polymer nanocomposite depend strongly on the dispersion and adhesion of the filler at the filler matrix interface thus surface treatment of the fillers with silane coupling agent is necessary to improve compatibility between the filler and matrix (10,11). both zro2 and tio2 nanoparticles have interesting mechanical, physical and photocatalystic properties that make them suitable additives.furthermore, many properties of this mixed nanostructured metal oxides (zro2:tio2) were reported to be better than single additive mainly due to the size difference between titanium and zirconium (12). this study is performed toproduce a new modified polymer nanocomposite by adding surface treated zro2:tio2 nanoparticles to heat polymerized acrylic resinand assess its impact strength, transverse strength, and thermal conductivity. materials and methods the materials that were used in the current studyare illustrated in table 1. j bagh college dentistry vol. 27(3), september 2015 the influence of restorative dentistry 34 table 1: some of the materials that were used in the study materials trade manufacturer 1 zirconium oxide (zro2) nanofiller 7080nm hwnano (china) 2 titanium oxide (tio2) nanofiller<50 nm. nanoshell (usa) 3 trimethoxysilylpropyl methacrylate 98% silane no 253085-8. sigma-aldrich (germany) 4 heat-curing acrylic resin vertexdental b.v. holand surface modification of nanofillers introducing the reactive groups onto the surface of nano fillers was achieved by the reaction of tri(methoxysilylpropylmethacrylate) silane coupling agent with the nanofillers using 5% wt. of tmspm for surface modification of zro2 nanoparticles (13) and 75% wt. of tmspm for surface modification of tio2 nanofillers (14). preparation of test specimens three plastic patterns were constructed according to the required test. for impact strength test, a bar shaped specimen with [(80mm x 10mm x 4mm) ± 0.2mm] length, widthand thickness respectively (15) was used while for transverse strength test a bar shaped specimens with dimensions of [(65mm length, 10mm width, and 2.5mm thickness)± 0.2mm] (16). thermal conductivity test: disk with dimension of 40mm in diameter and 2.5mm in thickness according to instrument specification (thermal constant apparatus) as shown in figure1. mold preparation the plastic patterns were coated with a thin layer of separating medium (isodent. spofa dental, europe) and allowed to dry before being invested. investing started by filling the lower half of the metal flask with type iv dental stone (elite stone, italy) mixed with the ratio of (powder to water was 100g/25ml) according to the manufacturer instructions, then plastic patterns were inserted incompletely into the stone and after the investing stone sets it was coated with separating medium and allowed to dry, then the upper half of the flask was fitted upon the invested one and filled with stone on the vibrator to avoid air babbles. after complete setting of the stone the flask opened carefully to separate the two halves as shown in figure (2) and the plastic patterns were removed from the molds carefully. the two portions of the flask were coated with a separating medium (cold mold seal) to be ready for packing of acrylic resin. proportioning and mixing of acrylic amounts of polymer and monomer for control group along with the percentage of silanized nano fillers used in the study group are presented in table (2). figure 1: test specimens a: impact test, b: transverse test, c: thermal conductivity test. figure 2: mold preparation for transverse test specimens j bagh college dentistry vol. 27(3), september 2015 the influence of restorative dentistry 35 table 2: proportioning and mixing of acrylic resin conc. of the addition proportion 1 : 1 polymer (g) mono-mer (ml) zro2 tio2 0% (control) 0 0 22g 10 ml 2% (study) 0.22 g 0. 22g 21.56 g 10 ml for test group 2% of a mixture of the modified nano fillers (zro2 :tio2)was added by weight in equal proportion (1:1) with the aid of an electronic balance of (0.0001g) accuracy, the fillers were well dispersed in the monomer by ultra-sonication using probe sonication apparatus (soniprep-150, england)(120 w, 60 khz) for 3 minutes (17). then it was immediately mixed with acrylic powder to reduce the possibility of particle aggregation and phase separation. the mixing of acrylic resin was carried out and manipulated according to manufacturer’s instructions in a clean and dry mixing container and by a clean wax knife for 30 seconds; thenpacking of the heat cure acrylic resin was done in the dough stage (16). after collecting dough mix, it was rolled and packed in the molds that were already painted with a separating medium and allowed to dry, then clamping was done and impart to the water bath. curing the curing process was carried out according to the manufacturer’s instructions, startedby placing the clamped flasksin adigital water bath (memert, germany) at room temperature (25º c ±2), then temperature increases gradually until reaching the boiling point (100º c) at which the processing was completed for 30 minutes, the entire cycle took about 2 hours. when the curing cycle is completedthe metal flasks were allowed to cool at room temperature for 30minutes, then left to cool under tab water for 15 minutes before deflasking (18). finishing and polishing after the specimens were carefully de-flasked, flashes of acrylic were removed with an acrylic bur and stone bur was used followed by (120) grain size sand paper with continuous water cooling. polishing was accomplished by using bristle brush and ruge wheel with pumice in lathe polishing machine then a gloss surface was obtained by using chamois baff and polishing swab on dental lathe, both were at low speed (1500rpm) with continuous cooling to avoid over heating which may lead to distortion of the specimens. impact strength test atest specimen: ten specimens for control and ten for study group were constructed for impact strength measurements. acrylic specimens were conditioned by storing in distilled water at 37°c for 48 hours in an incubator before being tested (16). btesting equipment and procedure impact strength test was conducted with charpy impact testing device shown in figure (3). the specimen was supported horizontally at its both ends ad struck by a free swinging pendulum which released from a fixed height in the middle. a pendulum of 2 joules testing capacity was used. the scale reading gives the impact energy absorbed to fracture the specimen in joules when its strocked by a sudden blow. the charpy impact strength of unnotched specimen was calculated in kj/m2 as given by the following equation: (19) where:: is the impact absorbed energy in joules, : is the width in millimeters of the test specimens, : is the thickness in millimeters of the test specimens. transverse strength test a. test specimens: ten specimens for the studygroupwere constructed in addition to ten for the control group which makes total of (20) specimens for the measurement of transverse strength. all the specimens were immersed in distilled water in the incubator at 37°c for (48) hours before being tested (16). b. testing equipment and procedure the transverse strength was measured by three point bending using a universal instron testing machine (fig. 5). each specimen was positioned horizontally on the bending fixture which consists of two parallel supports that are (50) mm apart and the load was applied with a cross head speed of 1mm/min by a rod placed centrally between the supports making deflection until fracture occurs fig. (6) the transverse bend strength was calculated using the following formula: j bagh college dentistry vol. 27(3), september 2015 the influence of restorative dentistry 36       +      ++=      − 2111 12 . 1 2 12 .. td r tdd r te d tt k where: : is the peak load, : is the span length (50mm), : is the sample width, : is the sample thickness (19). thermal conductivity test a. test specimens: twenty specimens were prepared 10 for the control group and 10 for the experimental groupto measure the thermal conductivity. b. testing equipment and procedure the lee's disk method was used to measure the thermal conductivity of the specimens using lee's disk apparatus shown in figure (7) which consists of three brass discs that are 12.25 mm in thickness and numbered (1,2,3), each one is attached to a thermometer also numbered (1,2,3). an electric heater is fixed between the first (1) and second (2) brass discs and connected to d.c power supply. the specimen-polished from both sidesplaced between the second (2) and third (3) brass discs. the electric set up of the apparatus was conducted to power supply after covering the whole assembly to minimize the effects of draughts and providing laboratory condition (25º c± 2º c). thereafter (6v) voltage and (i=0.25a) current were applied to heat the brass disks (2, 3), temperatures of all disks increases gradually and were recorded every (5 minutes) until reaching to a constant temperature of all thermometers which means that the specimen can no more conduct heat. this process takes about 2 hours for each sample. the losses in heat (e) were calculated from the following equation (20) the thermal conductivity (k) was calculated from the following equation (20) by using the experimental reading (t1, t2, t3) and the dimensions of specimen(r, ds). where:i: the flowed current (a), v: the voltage (vol), r: the radius (mm), d: the thickness of the specimen (mm), d1, d2, d3: thickness of bras discs (1, 2, and 3) respectively (mm), t1, t2, t3: the temperature of discs (1, 2and 3) respectively(c), k: thermal conductivity, e: the amount of the thermal energy per unit area per second (w/m2.°c). ( )     ++ + +++= 3322 21 .1131 2 2 ...2..* tdtd tt dtderttervi ππ figure 5: instron testing machine. figure 6: specimen under stress. figure 3: impact testing devise (charpy type) figure 4: impact test specimens: a. before testing b. after testing a b j bagh college dentistry vol. 27(3), september 2015 the influence of restorative dentistry 37 figure 7: thermal conductivity testing apparatus. results and discussion impact strength mean values, standard deviation, standard error, independentt test and significance results of impact strength test in (kj/m²) are shown in table (3). table 3: descriptive statistics and groups' difference of the impact strength test (kj/m2). groups n mean s.d. s.e. t-test p-value sig. control 10 8.57 0.43 0.13 -3.845 0.001 hs study 10 9.83 0.94 0.29 the results of impact strength test in table (3) showed that addition of 2% nano zro2: tio2 in equal proportion to pmma caused a high significant increase in impact strength and this may be due to the surface modification of the nanofillers with tmspm coupling agent which provide better dispersion of particles in matrix; avoid agglomeration and in the same time improves inter facial adhesion of the fillers to polymer matrix due to the formation of cross-links or supramolecular bonding covering the nanofillers which in turn prevent the propagation of crack by transferring the stress from matrix to fillers (10). on the other hand the different nanoparticle sizes of metallic fillers used in the study (zro2 was70-80 nm, tio2 was<50 nm) provided additional improvement to the mechanical properties by inhibiting the spaces between oxide particles thus they fill the interstitial of polymer particles to give a heterogenous mixture and will not force the displacement of the segments of the polymer chain.(11) additionally the nanoparticles characterized by large specific surface area thus they have the ability to dissipate energy thus may enhance impact strength. the result of this study agreed with that obtained by safarabadi et al. (21). transverse strength test table (4) showed themean values, standard deviation, standard error and independent t test of the transverse strength test results. table 4: descriptive statistics and groups' difference of the flexural strength (n/mm2) groups n mean s.d s.e t-test p-value sig. control 10 85.17 3.49 1.10 -10.593 0.000 hs study 10 101.70 3.48 1.10 as presented in table (4) the result of 2% of zro2-tio2 nanoparticles caused highly significant increase in transverse strength of pmma as compared to control group, this could be attributed to the good distribution of the very fine and different sizes of nanofillers used in the study that enable them to enter between linear macromoleculars chains of the polymer and fill spaces between chains, there by restricting the segmental motions of the macromolecular chains and increasing strength and rigidity of the resin, so this improve fracture resistance and lead to improve transverse strength. in addition the increasein transverse strength could be due to the transformation toughening, when sufficient stress develops and micro crack begins to propagate, a transformation of nanoparticles from the meta stable tetragonal crystal phase to the stable monoclinic phase occurs which depletes the energy of crack propagation, also, in this process expansion of crystals occurs and places the crack under a state j bagh college dentistry vol. 27(3), september 2015 the influence of restorative dentistry 38 of compressive stress and crack propagation is arrested (19). additionally both van der waal forces and covalent bonding increases strength and adhesion force. the result of the present study agrees with those obtained by safarabadi et al., (21)alhareb and ahmed (22) and acosta-torres et al.(23). thermal conductivity test the mean values, standard deviation, standard error and independent t test of the thermal conductivity test results are shown in table (5). there was a non-significant increase in the values of thermal conductivity with the addition of zro2/tio2 nanoparticles, this may due to metallic properties of oxides & their ability to conduct heat as compared to the acrylic resin (thermal conductivity of zro2 1.83.0 w/m.k and that for tio2 11.7 w/m.k) additionally the surface treatment of the nano fillers which increases the cross linking during polymerization of pmma these cross links help in heat transmission through atoms in covalent bonds as the cross-linking of the double bonds and the other strong groups decrease the spaces and increase the crosslink, thus the heat transfer is more rapid due to the freevolume diminishing. (24) table 5: descriptive statistics and groups' difference of the thermal conductivity (w/m.c°) groups n mean s.d. s.e. t-test p-value sig. cont. 10 0.28 0.03 0.01 -0.597 0.558 ns study 10 0.29 0.03 0.01 references 1. sakaguchi rl, powers jm. craig's restorative dental materials. 13th ed. philadelphia: elsevier mosby; 2012. p. 163-76, 192-4. 2. pratibha y, mittal r, sood vk, garg r. effect of incorporation of silane-treated silver and aluminum microparticles on strength and thermal conductivity of pmma. j prosthodontics 2012; 21(7): 546-51. 3. cho k, yang j, park che. the effect of rubber particle size on toughening behaviour of rubbermodified poly (methyl methacrylate) with different test methods. polymer 1998; 39: 3073-81 4. vojdani m, khaledi aar. transverse strength of reinforced denture base resin with metal wire and eglass fibers. j dentistry 2006; 3(4): 167-72. 5. kassab bt, al-nema lm. evaluation of some mechanical properties of reinforced acrylic resin denture base material (an in vitro study). al–rafidain dent j 2009; 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5(4): 502. 12. tomar lj, chakrabarty bs. synthesis, structural and optical properties of tio2-zro2 nanocomposite by hydrothermal method. adv mat lett 2013; 4(1): 64-7. 13. nabil i. evaluation the effect of modified nano filler addition on some properties of the heat cure acrylic risen denture base material. m.sc. thesis, college of dentistry, university of baghdad, 2011. 14. chaijareenont p, takahashi h, nishiyama n, arksornnukit m. effect of different amounts of 3methacryloxypropyltrimethoxysilane on the flexural properties and wear resistance of alumina reinforced pmma. dental materials j 2012; 31(4): 623–8. 15. iso 179-1:2000: plastics -determination of charpy impact properties part 1: non-instrumented impact test. 16. american dental association specification no.12, guide to dental materials and devices. 10th ed. chicago, 1999; p:32. 17. solhil ma, nodehi a, mirabedini sa, kasraei s, akbari k, babanzadeh s. pmma-grafted nano clay as novel filler for dental adhesives. dent mater 2009; 25: 339-47. 18. craig rg, powers jm. restorative dental materials. 11th ed. st. louis: the c.v. mosby co.; 2002. p. 195,636-656. 19. anusavice kj. philips science of dental material. 11th ed. middle east and african edition; 2008. p. 143166,721-756. 20. chung dld. composite materials science and applications. 2nd ed. london: springer-verlag limited; 2010. 21. safarabadi m, khansarib nm, rezaei a. an experimental investigation of ha/al2o3 nanoparticles on mechanical properties of restoration materials. engineering solid mechanics 2014; 2: 17382. j bagh college dentistry vol. 27(3), september 2015 the influence of restorative dentistry 39 22. alhareb ao, ahmad za. effect of al2o3/zro2 reinforcement on the mechanical properties of pmma denture base. j reinf plast compos 2011; 30: 83-5. 23. acosta-torres ls, lópez-marín lm, nuñez-anita re, hernándezpadrón g, castaño-meneses vm. biocompatible metal-oxide nanoparticles: nanotechnology improvement of conventional prosthetic acrylic resins. j nanomat 2011; 2011: 1-8. 24. al-anie ta, hassan kth, al-hadithy ar. preparation and study hardness and thermal conductivity (tc) to polyester resin composite with (titanium dioxide, zinc oxide, acrlonitril, wood flour coconut). baghdad sci j 2010; 7(4): 1400-9. ةالخالص لممیزات الزال راتنج االكریلك الحراري المادة االكثر شیوعا واستخداما في تحضیر قواعد االطقم المتحركة لالسنان نظرا المتالكھا مجموعھ من ا:بیان المشكلة نظرا لضعفھا في تحمل الصدمة التي تتسبب غالبا في كسر قواعد االطقم النواحي السیما میكانیكیا بالرغم من ذلك فانھا لیست مثالیھ من جمیع. المرغوبة باالضافة الى رداءة التوصیل الحراري وتقییم بعض )راتنجاالكریلكالحراري/ ثنائیاوكسیدالتیتانیوم -ثنائیاوكسیدالزركونیوم(الھدف من الدراسة ھوتصنیع متراكببولیمرنانوي :الھدف من الدراسة بالمقارنة مع راتنج االكریلك الحراریز التوصل الحراريو قوة المستعرضة, مثل قوة الصدمةالخواص الفیزیائیة والمیكانیكیة لھ اكریلیت او المونومیر تمت معاملھ الجزیئات النانویة الوكسید الزركونیوم واوكسید التیتانیوم بالمادة الرابطة من ثم تم مزجھا مع المیث:المواد وطریقة العمل عینھ 60تم تحضیر .ومن ثم خلطھا مع البولي میثل میثكریلیت او البولیمیرمن اوكسید بنسب وزنیة متساویة % 2بتركیز باستخدام جھازالموجات الفوق صوتیھ ة مجامیع باالعتماد على الفحص ثالثتم تقسیم كل منھا الى , عینة 30مجموعة السیطرة و المجموعة التجریبیة كل منھما تحتوي على , قسمت الى مجموعتین .التوصیلیة الحراریة, متانھ الكسر, قوة الصدمة:عینات لكل من الفحوصات التالیة 10المجرى بواقع ید التیتانیوم مع المادة الرابطة اكد فحص االمواج التحت الحمراء حدوث الترابط بین الجزیئات النانویة لكل من اوكسید الزركونیوم واوكس:النتائج اما نتائج التحلیل االحصائي فاظھرت وجود زیادة معنویة في قوة الصدمة ومتانة الكسرلراتنج االكریلك الحراري بعد ) الترایمیثوكسي سیلیل بروبیلمیثاكریلیت( .االضافة بینما كان ھناك زیادة غیر معنویة في قابلیة التوصیلیة الحراریة كان لھ اثر مما تبین من النتائج یمكن ان نستخلص انھ معاملة الجزیئات النانویة لكل من اوكسید الزركونیوم واوكسید التیتانیوم بالمادة الرابطة :تاجاتاالستن دة في قوة الصدمة ومتانھ الكسر ایجابي على انتشارو قوة ترابط الجزیئات النانویة مع المادة االساس لراتنج االكریك الحراري بعد االضافة حیث ادت الى زیا .بالالضافة الى االثر االیجابي في زیادة التوصیلیة الحراریة 21. shahad f.doc j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 132 the effects of nano-hydroxyapatite and casein phosphopeptide-amorphous calcium phosphate in preventing loss of minerals from teeth after exposure to an acidic beverage (an in vitro study) shahad zahed al-janabi, b.d.s. (1) zeyneb a.a. al-dahan, b.d.s., m.sc. (2) abstract background: this study aimed to evaluate the effect of antierosive agents (10% nano-hydroxyapatite (nha), 10% casein phophopeptide-amorphous calcium phosphate (cpp-acp), and combination of 10% nha and 10% cppacp) on loss of minerals from enamel surface of permanent teeth treated with antierosive agents when exposed to an acidic beverage and investigate the morphological changes of treated enamel surface after demineralization with cola based beverage under scanning electron microscope (sem). materials and methods: sixty maxillary first premolars were randomly divided into four groups, 15 teeth for each group. group i treated with 10% nha, group ii treated with 10% cpp-acp, group iii treated with 10% nha and 10% cpp-acp, and group iv did not treat with any remineralizing agents. the teeth were immersed in the remineralizing solutions (10% nha, 10% cpp-acp, and combination of 10% nha and 10% cpp-acp) for 4 minutes twice daily for 28 days and then stored in the artificial saliva. the samples were immersed for 40 minutes in 20 ml pepsi cola (ph=2.5). atomic absorption spectrophotometer (aas) was used to record the calcium and phosphorus concentrationsin pepsi cola before and after demineralization with cola based beverage. sem also usedto examine the morphological changes occurs in enamel surface of each group after demineralization with cola based beverage. results: statistically, there is a highly significant increase in calcium concentration in pepsi cola (mg/dl) after demineralization with cola based beverage. group i showed the lowest changes in calcium concentration values among the three studied groups. group ii was the next, which also showed lower changes in calcium concentration values, then group iii while the highest changes were recorded in group iv. there is a highly significant reduction in phosphorus concentration in pepsi cola (mg/dl) after demineralization with cola based beverage. group i showed the lowest changes in phosphorus concentration values among the three studied groups. group ii was the next, which also showed lower changes in phosphorus concentration values, then group iii while the highest changes were recorded in group iv. statistically, a highly significant difference was showed in calcium and phosphorus concentrations between the four studied groups after demineralization with cola based beverage. group iv has a highly significant difference in comparison to group i, group ii, and group iii. conclusions: both the remineralizing agents (nha and cpp-acp) were found to be effective in inhibiting the demineralization caused by cola based beverage.the combination of nha and cpp-acp had no synergistic effect on remineralization. key words: nano-hydroxyapatite, casein phophopeptide-amorphous calcium phosphate, erosion, scanning electron microscope. (j bagh coll dentistry 2015; 27(4):132-137). introduction dental erosion is defined as the irreversible loss of tooth substance by a chemical process not involving bacteria. the main cause of dental erosion is acid exposure (1) ; this may be caused by a sudden increase in consumption of soft drinks, diet cokes and fruit juices, which seems to be more significant compared to the other etiologic factors (2). considering the deteriorating effects of acidic beverages on the microhardness of dental enamel, it is essential to search for a material that induces remineralization of erosive lesions. the results of a large number of studies have shown that tooth pastes and mouth washes containing nha have the potential to remineralize initial erosive lesions (3). (1) m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. nanotechnology is defined as the construction of materials, parts and useful systems with nanometer dimensions in longitudinal scale and subsequent application of the novel characteristics of this minimal scale technology (4, 5). nha is one of the byproduct of nanotechnology, with high tissue biocompatibility; therefore production of hydroxyapatite crystals in nanosizes enables higher compatibility with enamel crystals (6). nha was used as a source of calcium and phosphorus in a sports drink. it has some advantages of high biocompatibility and chemical homogeneity with sound tooth enamel. sports drink with nha may prevent dental erosion (7). cpp-acp nanocomplex had been shown to localize at the tooth surface and prevent enamel demineralization in laboratory, animal and human in situ trials (8). the cpp-acp has also been shown to remineralize enamel subsurface lesions in situ when delivered in oral care products. the j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 133 proposed anticariogenic mechanism for cpp-acp is the localization of amorphous calcium phosphate (acp) at the tooth surface which buffers the free calcium and phosphate ion activities, thereby helping to maintain a state of supersaturation with respect to tooth enamel, preventing demineralizationand enhancing remineralization(9). in the present study, the effect of remineralizing agents was evaluated on preventing the loss of minerals from treated enamel surface of permanent teeth after exposure to an acidic beverage. as far as it is known there is no previous iraqi study regarding the effect of nha in preventing the loss of minerals from the enamel surface after exposure to an acidic beverage, for this reason this study was conducted. materials and methods the sample: sixty sound human upper first permanent premolars freshly extracted for orthodontic purposes were used in this study with age 12 years old. sample preparation: the extracted teeth were cleaned using conventional hand piece and rubber cup with nonfluoridated pumice and stored in deionized water with thymol crystals at room temperature. the teeth were examined by visible light cure machine, any tooth had a visible fracture or a crack was discarded (10). a circle of 6mm in diameter were prepared on the buccal surface of each tooth by using adhesive tape. then an acid resistant nail varnish was used to paint each tooth, the adhesive tape was removed leaving a circular window of 6 mm in diameter on the buccal surface of each tooth (11). preparation of remineralizing solutions: nano-hydroxyapatite used in this study was hydroxyapatite nanopowder ca10 (po4) 6 (oh) 2 from mknano, mississauga, canada. 10% nha suspension solution, using 2 m hcl, ph adjusted to 7 (6, 12). 10% cpp-acp is produced by hydrolysis of casein to form casein peptide, which is then complexed with amorphous calcium phosphate to form a casein phosphopeptide amorphous calcium phosphate complex. the casein (10% w/v), trypsin (0.05% w/v), calcium chloride (100 mmol/l), disodium hydrogen phosphate (60 mmol/l) (13). preparation of artificial saliva: to prepare one liter of artificial saliva, different materials in different concentrations were dissolved in (985.5) ml deionized water. these materials are: sodium carboxymethyl cellulose (10 gm), sodium chloride (1 gm), sodium fluoride (0.0002 gm), calcium chloride (0.05 gm), potassium thiocyanate (0.01gm), sorbitol (1 gm), potassium chloride (1gm), magnesium chloride (0.05 gm), potassium phosphate (0.04 gm). sodium carboxymethyl cellulose dissolved in 100 ml boiling water and after cooling, each other material was dissolved in deionized water and added to sodium carboxymethyl cellulose solution, ph was equal to 7 (14). sample grouping: sixty teeth were divided into four groups according to the type of treatment. group i: 15 teeth treated with 10% nha solution. group ii: 15 teeth treated with 10% cpp-acp solution. group iii: 15 teeth treated with [10% nha and 10% cpp-acp] solution. group iv: 15 teeth left without treatment placed in artificial saliva. the teeth were treated with remineralizing solutions for 4 minutes twice daily, once in the morning and once at night for 28 days and then stored in artificial saliva between exposure to remineralizing solutions and for the remaining 12 hours overnight. each tooth was rinsed and dried with a piece of cotton before and after each immersion for 2 minutes and then stored in artificial saliva. incubator was used to maintain the temperature at 37ºc. after the samples were remineralized for 28 days, they were immersed in 20 ml pepsi cola (ph=2.5) for 40 minutes (15). biochemical analysis of pepsi cola: calcium of pepsi cola was analysed by using flame atomic absorption spectrophotometer following standardized procedure. inorganic phosphorus of pepsi cola measured by using a ready-made kit of (biomagrhreb, tunisia) and analyzed by uv visible recording spectrophotometry (cecil ce 7200 uk) machine. sem examination: representative specimens from all groups were randomly selected for sem sample preparation. these were then examined by using scanning electron microscope sem (tescanvega, usa) (6,12,15). statistical analysis data were computerized and analyzed using spss 19.0 software. student’s paired t-test was used to compare the calcium and phosphorus concentrations before and after demineralization with cola based beverage in the four studied groupsand anova was used to compare the calcium and phosphorus concentrations among groups after demineralization with cola based j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 134 beverage in the four studied groups, followed by lsd test. results statistically, there is a highly significant increase in calcium concentration in pepsi cola (mg/dl) after demineralization with cola based beverage. group i showed the lowest changes in calcium concentration values among the three studied groups (1.72 ± 0.08). group ii was the next, which also showed lower changes in calcium concentration values (1.96 ± 0.12), then group iii (2.31 ± 0.08) while the highest changes were recorded in group iv (3.72 ± 0.12) as demonstrated in table (1). there is a highly significant reduction in phosphorus concentration in pepsi cola (mg/dl) after demineralization with cola based beverage. group i showed the lowest changes in phosphorus concentration values among the three studied groups (9.56 ± 0.24). group ii was the next, which also showed lower changes in phosphorus concentration values (8.71 ± 0.18), then group iii (7.68 ± 0.19) while the highest changes were recorded in group iv (5.59 ± 0.19) as shown in table (2). statistically, a highly significant difference was showed in calcium and phosphorus concentrations between the four studied groups after demineralization with cola based beverage. group iv has a highly significant difference in comparison to group i, group ii, and group iii (table 3 and 4). as shown in figure (1): (a) a smooth and intact surface was obtained in the normal anatomical enamel surface before demineralization with cola based beverage. (b) specimen treated with 10% nha and demineralized with cola based beverage show that acicular crystals of nha sedimented on the enamel surface. this sedimented new layer will resist the demineralization. (c) specimen treated with cpp-acp and demineralized with cola based beverage, microscopic irregularities on the enamel surface were observed as adherent granules or globules. the deposited minerals on the enamel surface following mobilization of calcium and phosphate from the cpp-acp will resist the demineralization. (d) specimen treated with 10% nha and 10% cpp-acp and demineralized with cola based beverage show cubes like crystals formed from cpp-acp, were disorderly distributed on the enamel surface and filled with nha crystals. the new layer which sedimented on the enamel surface of the tooth didn’t resist the demineralization, so a honeycomb structure appeared in some regions on the surface of erosive lesions. (e) specimen that not treated with any remineralizing agents and demineralized with cola based beverage show many micro pores and honeycomb structure were apparent on the enamel surface. this specimen can’t resist the demineralization. table (1): descriptive statistics and state difference of calcium concentration (mg/dl) in pepsi cola for the four studied groups before and after demineralization with cola based beverage. groups state descriptive statistics states' comparison (d.f.=14) mean s.d. min. max. t-test p-value sig. nha before 1.50 0.00 1.50 1.50 -11.03 0.000 hs after 1.72 0.08 1.59 1.87 cpp-acp before 1.50 0.00 1.50 1.50 -14.45 0.000 hs after 1.96 0.12 1.81 2.13 nha+ cpp-acp before 1.50 0.00 1.50 1.50 -38.22 0.000 hs after 2.31 0.08 2.16 2.46 no treatment before 1.50 0.00 1.50 1.50 -71.82 0.000 hs after 3.72 0.12 3.51 3.89 j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 135 table (2): descriptive statistics and state difference of phosphorus concentration (mg/dl) in pepsi cola for the four studied groups before and after demineralization with cola based beverage. groups state descriptive statistics states' comparison (d.f.=14) mean s.d. min. max. t-test p-value sig. nha before 11.50 0.00 11.5 11.5 30.92 0.000 hs after 9.56 0.24 9.24 9.96 cpp-acp before 11.50 0.00 11.5 11.5 59.62 0.000 hs after 8.71 0.18 8.28 8.97 nha+ cpp-acp before 11.50 0.00 11.5 11.5 76.36 0.000 hs after 7.68 0.19 7.34 7.98 no treatment before 11.50 0.00 11.5 11.5 117.86 0.000 hs after 5.59 0.19 5.25 5.84 table (3): descriptive statistics and group difference for calcium concentration (mg/dl) in pepsi cola after demineralization with cola based beverage. groups descriptive statistics groups' comparison (d.f.=59) mean s.d. min. max. f-test p-value sig. nha 1.72 0.08 1.59 1.87 1148.77 0.000 hs cpp-acp 1.96 0.12 1.81 2.13 nha+cpp-acp 2.31 0.08 2.16 2.46 no treatment 3.72 0.12 3.51 3.89 table (4): descriptive statistics and group difference for phosphorus concentration (mg/dl) in pepsi cola after demineralization with cola based beverage. groups descriptive statistics groups' comparison (d.f.=59) mean s.d. min. max. f-test p-value sig. nha 9.56 0.24 9.24 9.96 1053.09 0.000 hs cpp-acp 8.71 0.18 8.28 8.97 nha+cpp-acp 7.68 0.19 7.34 7.98 no treatment 5.59 0.19 5.25 5.84 (a) (b) (c) (d) (e) figure (1): sem images of a representative specimen in different groups after demineralization with cola based beverage: (a) sound enamel surface, (b) group i (treated with nha, (c) group ii (treated with cpp-acp), (d) group iii (treated with nha and cppacp), (e) group iv (no treatment). j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 136 discussion dental erosion was effectively prevented by the increase in ph and the degree of saturation with respect to dental enamel (dsen) which was caused by abundant release of calcium, phosphate and hydroxide ions from remineralizing agents, and the incapability of phosphoric acid to chelate with enamel calcium. most calcium compounds are known to have low solubility and it makes them less manageable. however, in the present study the use of nanotechnology allowed the release of ions from hydroxyapatite in great quantities. the solubility was reported to dramatically increase per unit time due to the higher specific surface area and low crystallinity of the nano-sized crystals. therefore more active constituents can be released (16-18). due to low solubility of pure hydroxyapatite, no enough calcium and phosphorus were available to increase the stability of hydroxyapatite in the enamel and to prevent dissolution of the dental enamel. since the surface area and proportion of atomicity increase with decreasing particle size, nha has bioactive and biocompatible properties to be used in this study (19). pepsi cola was used in this study to induce artificial erosive effect as in other studies (20,21). pepsi cola is the most popular and most widely drinks used in the country. when the changes in calcium concentrations in pepsi cola after demineralization with cola based beverage were measured, group i showed the lowest changes in calcium concentrations values among the three studied groups. group ii came the next, which also showed lower changes in calcium concentrations values, then group iii while the highest changes were recorded in group iv. there is a highly significant increase in calcium concentrations before and after demineralization of all groups. this increase in calcium concentrations in pepsi cola means that there was some loss of calcium from the enamel surface of the teeth after demineralization with cola based beverage. when also the changes in phosphorus concentrations in pepsi cola after demineralization with cola based beverage were measured, group i showed the lowest changes in phosphorus concentrations values among the three studied groups. group ii came the next, which also showed lower changes in phosphorus concentrations values, then group iii while the highest changes were recorded in group iv. there is a highly significant reduction in phosphorus concentration before and after demineralization of all groups. this reduction in phosphorus concentration in pepsi cola means that the acidic nature of phosphoric acid had the ability to chelate calcium in saliva and on tooth surface, so their potential to cause erosion is strongly dependent on this effect (22). a highly significant difference in calcium and phosphorus concentration between the four studied groups after demineralization with cola based beverage. group iv has a highly significant difference in comparison to group i, group ii, and group iii. the direction of calcium and phosphorous concentrations were inversely increased. so when the calcium concentration increased, the phosphorous concentration was decreased. this result is in agreement with hegde et, al., (15). from the results of this study mentioned above, it has been concluded that both the remineralizing agents (nha and cpp-acp) were able to provide protective effect against erosive enamel loss. nha has better protective effect than cpp-acp. so using nha as a mouth wash or adding to tooth paste or sport drink or chewing gum can enhance remineralization and prevent loss of minerals from enamel surface. on the other hand, both the remineralizing agents (nha and cpp-acp) were found to be effectivein inhibiting the demineralization caused by cola based beverage. among the remineralizing agents used in the present study, nha was found to be more effective than cppacp and combination of nha andcpp-acp. the combination of nha and cpp-acp had no synergistic effect on remineralization. references 1neville bw, damm d, allen gm, bouquot je. oral and maxillo facial pathology. 2nd ed. new york: sheefer john; 2002. p. 55-58. 2bello ll, al-hammed n. pattern of fluid consumption in a sample of saudi arabian adolescents aged 12-13 years. int j pediatr dent 2006; 16(3): 16873. 3haghgoo r, abbasi f, rezvani mb. evaluation of the effect of nano-hydroxyapatite on erosive lesions of the enamel of permanent teeth following exposure to soft beer in vitro. scientific research and essays 2011; 6(26): 5933-6. 4freitas ra. nanodentistry. j am dent assoc 2000; 131:1559-65. 5jhaver hm. nanotechnology: the future of dentistry.j nano sci nano technol 2005; 5: 15-7. 6huang s, gao s, yu h. effect of nanohydroxyapatite concentration on remineralization of initial enamel lesion in vitro. biomed mater 2009; 4(3): 034101. 7min jh, kwon hk, kim bi. the addition of nanosized hydroxyapatite to a sports drink to inhibit dental erosion: in vitro study using bovine enamel. j dent 2011; 39(9): 629-35. 8 reynolds ec. remineralization of enamel sub surface lesions by casein phosphopeptide stabilized calcium phosphate solutions. dent res j 1997; 76: 1587-95. j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 137 9reynolds ec, cai f, cochrane nj, shen p, walker gd, morgan mv. fluoride and casein phosphopeptide amorphous calcium phosphate. res dent j 2008; 87: 344-8. 10parry j, shaw l, arnand mj, smith aj. investigation of mineral waters and soft drinks in relation to dental erosion. j oral rehabil 2001; 28: 766-72. 11bartlett dw, coward py. comparison of the erosive potential of gastric juice and a carbonated drink in vitro. j oral rehabil 2001; 28: 1045-7. 12huang s, gao s, cheng l, yu h. combined effects of nano-hydroxyapatite and gallachinensis on remineralization of initial enamel lesion in vitro. journal of dentistry 2010; 38: 811–9 (ivsl). 13tarautino lm. opinion of an expert panel on the generally recognized as safe (gras) status of calcium casien peptone-calcium phosphate, 1998. 14björklund m, ouwehand a, forssten s. improved artificial saliva for studying the cariogenic effect of carbohydrates. curr microbiol 2011; 63(1): 46-9. 15hegde mn, devadiga d, jemsily pa. comparative evaluation of effect of acidic beverage on enamel surface pre-treated with various remineralizing agents: an in vitro study: j cons dent 2012; 15(4): 351-6. 16xu hh, weir md, sun l. nanocomposites with ca and po4 release: effects of reinforcement, dicalcium phosphate particle size and silanization. dental materials 2007; 23:1482-91. 17weir e, lawlor a, whelan a, regan f. the use of nanoparticles in antimicrobial materials and their characterization. analyst 2008; 133(7): 835-45. 18sun l, chow lc. preparation and properties of nanosized calcium fluoride for dental applications. dental materials 2008; 24:111–6. 19kaehler t. nanotechnology: basic concepts and definitions. clin chem 1994; 40: 1797-9. 20devlin h, bassiouny ma, boston d. hardness of enamel exposed to coca-cola and artificial saliva. j oral rehabil 2006; 33: 26-30. 21tantbirojn d, huang a, ericson md, poolthong s. change in surface hardness of enamel by a cola drink and a cpp-acp paste. j dent 2008; 36(1): 74-9. 22johansson ak, lingstrom p, birkhed d. comparison of factors potentially related to the occurrence of dental erosion in high and low-erosion groups. eur j oral sci 2002; 110: 204-122. rafal f.doc j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 79 histological evaluation of local application of collagen i and /or vascular endothelial growth factor (an experimental study in rats) rafal rashid, b.d.s. (1) athraa y. al-hijazi, b.d.s., m.sc., ph.d. (2) abstract background: the study was designed to evaluate the effect of local application of exogenous vegf/collagen i separately and as a combination in socket healing. sixty male albino wistar rats were subjected for a surgical tooth extraction of upper 1st molar of both sides (right side was considered as experimental site, while left be the control one, treated with 1µl of normal saline). the rats were scarified at 3, 7, 14, 28 days post extraction. socket healing was histologically examined with immunohistochemistochemical localization of alp&fgf2. materials and method: sixty male albino wistar rats were subjected for a surgical tooth extraction of upper 1stmolar of both sides (right side was considered as experimental site, while left be the control one). the animals were divided into following groups according to the applicable of biomaterials. a. control group the tooth socket treated with 1μl of normal saline b. experimental group includes • group i contains (20) rats, the tooth socket treated with 1μl of vegf • group ii contains (20) rats the tooth socket treated with 1μl of collagen type i • group iii contains (20) rats, the tooth socket treated with 1μl of a combination of vegf and collagen i. results: at 28 days all groups show re-epithelization but in different thickness, and with newly bone apposition and with different maturity. for positive cells expressed alp, vegf group records a high mean values at 3, 14, 28 days periods and with high differences in comparison to other groups while control group reports a high mean value at 7 days. for positive cells expressed fgf2. control group illustrates a high record for the mean of positive cells expressed fgf2 at 3,7days periods and with high differences in comparison to other groups, while combination group reports a high mean value at 14 days . conclusion: results, high lighted on the effect of local application of vegf in extracted tooth socket that facilitate epithelization, while combination of (collagen and vegf) shows a high mineralization zone. keywords: exogenous vegf/collagen i, healing, extraction. (j bagh coll dentistry 2015; 27(3):79-84). introduction tooth in the maxillary or mandibular alveolar process is surrounded and anchored by tissues that make up the periodontium. the periodontium includes gingiva, connective tissue, cementum, periodontal ligament, and alveolar bone. the alveolar bone consists of cortical bone, cancellous trabeculae, and the alveolar bone proper, which is compact bone that composes the alveolus (tooth socket). the normal healing response to the tooth extraction procedure results in a significant loss of bone and collapse of the surrounding gingival tissue, followed by regeneration of epithelial and connective tissues(1). healing process at extraction sites, including bone resorption and remodeling, which are fundamental events in socket healing. changes occur at molecular, cellular, and tissue levels. extraction of a tooth commences a cascade of inflammatory reactions (2). blood from severed vessels fill the socket creating a mixture of proteins and damaged cells. blood platelets initiate a series of events that will ultimately lead to the formation of a fibrin clot, (1)master student. department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. filling the entire socket, within the first 24 hours (3). the coagulum, facilitated by growth factors, acts as a physical matrix and directs the movement of the inflammatory cells, neutrophils and macrophages enter the socket to phagocytize bacteria and tissue debrisreleased growth factors and cytokines induce and amplify the migration of mesenchymal cells and their synthesis within the coagulum (4). several growth factors are expressed in distinct temporal and spatial patterns during repair. of these, vascular endothelial growth factor, vegf, is of particular interest because of its ability to induce neovascularization (angiogenesis) and its role to promote healing of bone defects (5). collagen 1 is the most abundant collagen of the human body. it is present in scar tissue, the end product when tissue heals by repair. it is found in tendons, skin, artery walls, cornea, the endomysium surrounding muscle fibers, fibrocartilage, and the organic part of bones and teeth. collagen has the correct properties for tissue regeneration such as pore structure, permeability, hydrophilicity and it is stable in vivo. collagen scaffolds are also ideal for the deposition of cells, such asosteoblastsandfibroblastsand once inserted, j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 80 growth is able to continue as normal in the tissue (6). therefore; the present research was designed for application of vegf / collagen 1 in rat tooth socket and determine their roles in healing process. materials and methods all experimental procedures were carried out in accordance with the ethical principles of animal experimentation. study design sixty male albino wistar rats weighting (250300) gm, aged 5-6 months were used and maintained under control conditions of temperature, drinking and food consumption. the animals were subjected for a surgical tooth extraction of rat upper 1st molar of both sides (right side was considered as experimental site, while left be the control one). the animals were divided into following groups according to the applicable of biomaterials. a. control group the tooth socket treated with 1µm of normal saline and its number represented the all number of the following experimental groups as the left side of each animal considered to be the control. b. experimental group includes -group i contains (20) rats, the tooth socket treated with 1µm of vegf -group ii contains (20) rats the tooth socket treated with 1µm of collagen type 1 -group iii contains (20) rats, the tooth socket treated with 1µm of a combination of vegf and collagen type-1. each group is composed of 20 rats that will be studied in four periods 3, 7, 14, 28 days (5 rats for each period). materials • vegf 165a protein (rat) (ab51967), lyophilized form from abcam company • collagen type-1 protein. abcam company (ab7533). • *alkaline phosphatase antibody (alp) from abcam company uk (ab56023). • fibroblast growth factor antibody (anti – fgf2), from abcam company uk (ab106245). methods it was performed under a well sterilized condition and gentle surgical technique. each animal was weighted to calculate the dose of general anesthesia and antibiotic, the general anesthesia was induced by intra muscular injection of xylazine 2% (0.4 mg/kg b.w.), plus ketamine hcl 50mg (40 mg/kgb.w.). then the animal was placed on the surgical table and the gingivae of upper posterior 1st molar tooth is separated with dental probe. an enamel hatchet was then positioned between the first and second molars allowing avulsion of the dentalreminiscent. tooth socket cleaned with saline irrigation, then dryness with air. application of 1µl of vegf and/or collagen type-1 was applied by micropipette for experimental sockets while 1µl of normal saline applied to control one. the socket was closed with gentle pressure by fingers. assessment of immunohistochemistry results positive reading was indicated when the cells display a brown cytoplasmic stain, while negative reading was indicated for absence of immunereactions depends on positive and negative control. immunohistochemical scoring of fgf2, alp: quantification method of immunoreactivity was semi-quantitatively estimated the immunostaining score that was calculated as the sum of a proportion score and an intensity score. the proportion score reflects the estimated fraction of positively stained infiltrating cells. for fgf, alp, it was assessed by identifying and scoring 100 cells in five fields (x40) along bone defect area of different sections (score 0, none; score 1, <10%; score 2, 10-50%; score 3, 51-80%; score 4, >80%) (7). results histological findings control group at 3 days duration shows blood clot illustrates bypresence of inflammatory cells include polymorphic nuclear cell, monocyte cell, plasma cell (figure 1). socket healing site for7days duration shows filled with fibrin clot, illustrates fibroblast and lymphocytes (figure 2). re-epithelization, bone trabeculae filled the base of the socket with fibrous tissue are detected at 14 days post extracted period (figures 3 and 4). at 28 days duration shows re-epithelization cover a fibrous tissue, then new bone (figure 5). j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 81 figure 1: microphotograph view for control group shows blood clot illustrates plasma cell (arrow heads), lymphocyte (arrows). h&e x20. figure 2: view for socket healing shows fibrin clot, illustrates fibroblast (arrows), lymphocyte (arrow heads)control group (7days) .h&exx20 figure 3: re-epithelization is detected in control group (14 days). h&ex 10. figure 4: bone trabeculae (bt) filled the base of the socket with fibrous tissue (ft), control group (14 days). h&ex20 figure 5: view for control (28 day) shows reepithelization (re) cover the healing socket fibrous tissue (ft) ,then new bone (nb) h&ex10. experimental group: alveolar socket treated with vegfillustratedfibrin clot, new blood vessels, and osteoclast in bone socket is detected at 3 days (figures 6 and 7). at 7days duration shows osteocyte occupies resorptive howship's lacunae, osteoblast and new bone apposition (figure 8). bone trabeculae filled the base of the socket coalesce with bonesocket re-epithelization of the socket surface .proliferating osteoblasts, pre osteocyte and osteocytes are detected in histological sections of 14 days duration (figures 9 and 10). the period 28 days duration illustrated new bone with multiple harvasian canals filled all socket covered by new epithelium, proliferating basal cell of epithelium tissue (figures 11 and 12). figure 6: angiogenesis illustrates clot (3 day) for vegf group, blood vessels (arrow heads) .h&ex20 j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 82 figure 7: osteoclasts (arrows) illustrate in vegf (3 days) in bone socket (bs). h&ex40 figure 8: view for vegf group (7 day) shows osteoclast (pink arrow), osteoblast (green arrows), new bone apposition occupies howship's lacunae (pink arrow heads) h&ex100. figure 9: view for extracted socket of rat in vegf group (14 days) shows bone trabeculae (bt) filled the base of the socket, bone socket (bs) and osteoid tissue (ost), re-epithelization of the socket surface (arrow). h&ex10. figure 10: base of the socket illustrates bone trabeculae (bt) that surrounded by bone socket (bs) at 14 days. h&e x20 figure 11: view for socket of vegf group (28 day) shows new bone (nb) filled all socket covered by new epithelium (nep) h&e x20 figuer 12: proliferating basal cell of epithelium tissue (arrows). h&ex40. experimental group: alveolar socket treated with collagen i shows fibrin clot, with cutting epithelial edges, osteoid tissue apposition, and identification of osteoclast, at 3 days (figure 13). new bone apposed in base of the socket in collagen i group at 7 days (figure 14). alveolar socket for collagen group at 14 days duration shows bone trabeculae coalesce with bone socket (figure 15). at 28 days, new epithelization (nep), and fibrous tissue recognized (figure 16). j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 83 figure 13: view for fibrin clot, with cutting epithelial edges, osteoid tissue apposition, identification of osteoclast at (3days). figure 14: new bone apposed in base of the socket in collagen i group at7 days figure 15: alveolar socket for collagen group at 14 days duration shows bone trabeculae coalesce with bone socket. figure16: new epithelization (nep), fibrous tissue recognized underneath. discussion in the present study, the effect of application of vegf in extracted rat socket was investigated histologically .the result illustrates a formation of blood clot at 3 days ,although some samples show a fibrin clot too. osteoclast cell with obvious angiogenesis is detected early in vegf group, this may explained as van bruggen (8) reported that vegf is mitogenic, angiogenic, and a potent mediator of vascular permeability. vegf causes extravasations of plasma protein and increases hydraulic conductivity in isolated perfuse micro-vessels, that help mono-nucleated cell to recruit and aggregate as osteoclast and begins to resorbed old bone and enhanced bone matrix apposition which appears early in vegf group. cornelini et al. (9) demonstrated that angiogenesis is an important feature of inflammation and healing and its role in the development and progression or in the wound healing related to vascular endothelial growth factor (vegf) as a potent inducer of endothelial cell proliferationthe present findings shows that vegf group illustrates osteoclast with high mean value (at 3 days) regarding to other groups. according to yang et al., (10) findings that show vegf is directly targets osteoclasts, thereby playing a novel role in bone development and angiogenesis. collagen is a natural product, therefore it is used as a natural wound dressing and has properties that artificial wound dressings do not have. it is resistant against bacteria, which is of vital importance in a wound dressing. it helps to keep the wound sterile, because of its natural ability to fight infection. when collagen is used as a burn dressing, healthy granulation tissue is able to form very quickly over the burn, helping it to heal rapidly singh et al. (11). in present study application of exogenous collagen 1 demonstrated a fibrin clot with early detection of osteoid tissue at 3 days, this result could be explained that healing of the rat tooth extraction socket occurs rapidly, indicating a mechanism for cancellous bone formation occurring swiftly throughout the matrix. the residual periodontal ligament is evident at 2 days after extraction and its rich collagen type iii fiber content, while collagen type i fibers were formed later, and were especially evident at 6 days after extraction, as normal healing events devlin (12) therefore application of exogenous collagen i appears to be affected at 3 days instead of 6 days and may form an early template for future cancellous bone formation. after 7 days the pattern of distribution of both collagen type i and iii fibers were similar as they passed from the j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 84 bone margin towards the centre of the socket in the same direction as the forming bone trabeculae. bone formation occurs by rapid movement of the osteoprogenitor cells along these collagen fibers to allowa rapidhealing. socket healing constitutes a complex and delicate physiological process. local vascularity at the site of the extracted teeth has been identified as one of the most significant parameters influencing the healing procedure. vegf is the most important component of the regeneration of the vascular system at the healing site. references 1. vinnakota dn, akula sr, krishna reddy vv, sankar vv. a staged approach of implant placement in immediate extraction sockets for preservation of periimplant soft and hard tissue. indian soc periodontol 2014; 18(2): 267-71 2. dias-da-silva ma, pereira ac, marin mc, salgado ma. the influence of topic and systemic administration of copaiba oil on the alveolar wound healing after tooth extraction in rats. j clin exp dent 2013; 5(4): e169-73. 3. al-obaidi mm, al-bayaty fh, al batran r, hassandarvish p, rouhollahi e. protective effect of ellagic acid on healing alveolar bone after tooth extraction in rat-a histological and immunohistochemical study. arch oral biol 2014; 59(9): 987-99 4. geurs n, ntounis a, vassilopoulos p, van der velden u, loos bg, reddy m. using growth factors in human extraction sockets: a histologic and histomorphometric evaluation of short-term healing. j oral maxillofac implants 2014; 29(2): 485-96. 5. wang l, gao w, xiong k, hu k, liu x, he h.vegf and bfgf expression and histological characteristics of the1bone-tendon junction during acute injury healing. sports sci med 2014; 13(1): 15-21. 6. oliveira s, ringshia r, legeros r, clark e, terracio l, teixeira c, yost m. an improved collagen scaffold for skeletal regeneration. j biomedical materials 2009; 94(2): 371–9. 7. suzuki s, dobashi y, hatakeyama y, tajiri r, fujimura t, heldin ch, ooi a. clinicopathological significance of platelet derived growth factor (pdgf)b and vascular endothelial growth factor-a expression, pdgf receptor-b phosphorylation, and micro-vessel density in gastric cancer. bmc cancer 2010; 30(10): 659. 8. van bruggen n, thibodeaux h, palmer jt, lee wp, fu l, cairns b, tumas d, gerlai r, williams sp, van lookeren campagne m, ferrara n. vegf antagonism reduces edema formation and tissue damage after ischemia/reperfusion injury in the mouse brain. j clin invest 1999; 104(11): 1613-20. 9. cornelini r, artese l, rubini c, fioroni m, ferrero g, santinelli a, piattelli a. vascular endothelial growth factor and micro-vessel density around healthy and failing dental implants. int j oral maxillofac. implants 2001; 16(3): 389-93. 10. yang q, mchugh kp, enhancement of osteoclast survival and bone resorption involves vegf receptor2 signaling and beta 3-integrin. matrix biol 2008; 27(7): 589-99. 11. singh o, gupta ss, soni m, moses s, shukla s, mathur rk. collagen dressing versus conventional dressings in burn and chronic wounds: a retrospective study. j cutaneous aesthetic surgery 2014; 1: 12–16. 12. devlin h. early bone healing events following rat molar tooth extraction. cells tissues organs 2000; 167(1): 33-7. proven sealability | dependable quality | efficient removal | clinical applications j bagh college dentistry vol. 29(1) march 2017 gingival microleakage restorative dentistry 16 gingival microleakage of composite restorations with different bonding protocol in class ii cavity treated with chlorhexidine (an in-vitro study). aliaa m. jabbar. b.d.s., m.sc. (1) abstract background: one of the challenges to use chlorhexidine is its effect on the amount of microleakage after restoration; however, use of the materials with antibacterial properties after tooth preparation and before restoration has been widespread. the objective of this, in-vitro, study was to evaluate the influence of consepsis (chlorhexidine gloconate disinfectant) application on microleakage in class ii cavities restored with light cured composite using universal adhesive system; etch and rinse technique –self etch technique. materials and methods: forty class ii cavities were prepared on mesial and distal surfaces of 20 non-carious mandibular third molars. the cavities were divided into four groups; (n =10 for each group). g1: cavities were bonded with (single bond universal adhesive, 3mespe) after etching with 35% phosphoric acid etch and rinse technique, without chlorhexidine , g2: chlorhexidine was used after etching with 35% phosphoric acid, then cavities were bonded with (single bond universal adhesive, 3mespe) etch and rinse technique . g3: cavities were bonded with (single bond universal adhesive, 3mespe) self etch technique, without chlorhexidine, g4: the chlorhexidine was used before bonding. all groups were restored with non – hybrid composite resin (z 350, 3mespe). micrlerackage was evaluated at gingival margin using methylene blue dye penetration method. in each cavity the dye penetration in millimeters was measured by strereomicroscope. statistical analysis for the data was carried out using one-way anova and lsd test. results: group g2 produced the least microleakage which is statistically highly significantly different than the remaining groups. group g3 produced the highest microleakage which is statistically high significant difference than g1 and g2, but the difference is not significant with group g4. conclusions: consepsis can be used as cavity disinfectants when restoring the cavities with single bond universal adhesive as etch and rinse technique. however, its effect seems to be lower when using the single bond universal adhesive as self-etch technique. )19-6(j bagh coll dentistry 2017; 29(1):1 universal adhesive. chlorhexidine, microleackage, keywords: introduction the most significant problem associated with the composite restorations is the polymerization shrinkage, as it has the potential to initiate gap formation at the tooth-composite interface, which can lead to microleakage, secondary caries, and eventually leading to failure of the bond. micro leakage remains a problem of clinical significance, although various generations of dentin bonding agents have been developed to reduce the effects of polymerization shrinkage (1). incomplete sterilization of the preparation as a consequence of failure to mechanically remove infected tooth structure can be magnified the problems associated with microleakage. a number of studies have demonstrated that the bacteria left in the dentin of a cavity preparation could maintain their activity for a long time, only a small proportion of the teeth are sterile after cavity preparation as have shown by histological and bacteriologic studies (2). the use of a disinfectant solution has been suggested to solve this issue. previous studies have depicted that a number of antibacterial solutions such as chlorhexidine, sodium hypochlorite, fluoride based solutions and bensalkonum chloride, (1) assistant lecturer, department of conservative dentistry, college of dentistry, university of baghdad. can be used as cavity disinfectants to eliminate residual bacteria from prepared cavities. some of the disinfectant solutions were found not to affect either the bond strength or the sealing ability of dentin bonding agents. however, depending on the brand of materials and application methods, some of the solutions have shown an adverse effect on the issues mentioned (3). the aim of this study was to evaluate the influence of consepsis (chlorhexidine gloconate disinfectant) application on microleakage of compsite returations in class ii cavities restored with light cured composite using universal adhesive system. materials and method a total 20 freshly extracted caries free, human permanent mandibular third molars were selected for this study. immediately after extraction, the teeth were cleaned of debris with scaler, then pumiced with a rubber prophylaxis cup and pumice for 30 seconds after that, the teeth were stored in normal saline for maximum period of one month (at 400c until use) (1, 2). the criteria for tooth selection included (1) an intact crown enamel and (2) lack of caries or cracks (4). proximal boxes of standard dimensions were j bagh college dentistry vol. 29(1) march 2017 gingival microleakage restorative dentistry 17 prepared on both proximal surfaces in all twenty teeth resulting in forty cavities figure 1. figure 1: a diagram showing the dimensions of cavity design used in this study. cavity preparation was made by using diamond round bur (ref s6801, komet, germany) and a parallel sided flat-ended diamond fissure bur (ref s6835, komet, germany), both with a high speed and water cooled hand piece (nsk). the occlusal portion of the preparation had a faciolingual width of 2 mm. the gingival floor of the proximal box was kept 1mm below the cementoenamel junction to keep the gingival margins in dentin (1). each preparation was rinsed for 20 seconds with distilled water and dried with blast of compressed air for 5 seconds. caution was taken not to over dry the preparation. the samples were randomly distributed in to four experimental groups, each consisting of 10 cavities. all the cavities were restored as given below: group 1(g1): the cavity surfaces were treated with 35% phosphoric acid for 15 seconds, washed and blot dried. then, the bonding agent (single bond universal adhesive,3m espe) was applied according to manufacturer's instruction with saturated micro brush, rubbed on surface for 15 seconds and light cured for 20 seconds by vivadent light cure unit. the cavities were restored according to layering technique with nanohybrid composite (z350, 3m esep) and each increment was light cured for 20 seconds. group 2 (g2): the cavity surfaces were treated with 35% phosphoric acid, washed and blot dried. 2% chlorhexidine cavity disinfectant (consepsis, ultradent) was applied with a sterile brush applicator. consepsis solutions consist of chlorhexidine gluconate and ethyl alcohol with a ph of 6.0. the disinfectant was left in contact with cavity walls for 20 seconds followed by blast of compressed air for 5 seconds (1).the bonding and restoration procedure was performed similar to g1. group 3 (g3): single bond universal adhesive was applied according to manufacturer's instruction with saturated micro brush, rubbed for 15 seconds and light cured for 20 seconds. the cavities were restored as in groups g1 and g2. group 4 (g4): a 2% chlorhexidine cavity disinfectant (consepsis, ultradent) was applied as group g2, single bond universal adhesive was applied according to manufacturer's instructions with a saturated micro brush, rubbed for 15 seconds and light cured for 20 seconds. the cavities were restored with composite as other groups of this study (table.1). table 1: groups of this study. groups acid etching disinfectant dentin bonding agent g1 total-etch no single bond universal adhesive g2 total-etch consepsis single bond universal adhesive g3 self-etch no single bond universal adhesive g4 self-etch consepsis single bond universal adhesive all teeth were stored in distilled water at 37 0c for 24 hours in incubator and then subjected for thermal cycling with 500 cycles between water baths of 50c and 550c with a dwell time of 15second (5, 6). the teeth were covered with two coats of nail varnish to within approximately 1mm away from the margins of proximal box, after the root apices were sealed with molding wax. the specimens were immersed in methylene blue dye in separated sealable vials at 370c for 24 hours. after staining the teeth were rinsed off to remove residual dye. the radicular parts of the teeth were cut 6mm below the cemento-enamel junction. coronal parts were sectioned mesiodistally in the approximate center of the restorations with a diamond disk in a straight air motor hand piece. the dye penetration of the gingival margins of each section was evaluated independently by two observers using a stereomicroscope type (hamilton, biovision 320 ) at a magnification of x40 and dye penetration was recorded in millimeters(7). then the data was analyzed using one way anova and lsd test. j bagh college dentistry vol. 29(1) march 2017 gingival microleakage restorative dentistry 18 results the results of this study were collected and analyzed statistically. the mean, standard deviations, standard error, minimum and maximum of the experimental groups are shown in table 2. table 2: descriptive statistics of all groups. groups n means ±sd min max g1 10 1.15 0.80 0.0 1.8 g2 10 0.29 0.32 0.0 0.8 g3 10 2.05 0.10 1.9 2.2 g4 10 1.97 0.08 1.8 2.1 under the experimental conditions of this study, group2 (total-etch with chlorhexidine) has the lowest mean value of microleakage while g3 (self-etch without chlorhexidine) has the highest mean value of microleakage figure 2. figure 2: the mean of microleakage of groups of this study. analysis of variance (anova) test showed that there were highly significant differences between the tested groups of this study table 3. table 3: one-way analysis of variance sum of squares df mean squares f p value between groups 20.371 3 6.790 35.634 0.000* within groups 6.860 36 0.191 total 27.231 39 *hs: highsignificant lsd test was performed regarding the sealing ability of the tested groups, table 4. lsd test showed that the group g1 has statistically high significant difference more microleakage, as compared with group g2 while the group g1 has statistically high significant difference less microleakage, as compared with group g3 and g4. also the results showed that the group g2 has statistically high significant difference less microleakage, as compared with group g3 and g4.while the group g3 has statistically non significant difference as compared with group g4. table 4: lsd test of groups of this study. i(groups) j(groups) mean difference p-value g1 g2 0.86 0.000* g3 -0.90 0.000 g4 -0.82 0.000 g2 g3 -1.80 0.000 g4 -1.70 0.000 g3 g4 0.08 0.684** *hs: highsignificant **ns: nonsignificant discussion one of the main factors stimulating the sensitivity of the pulp is infection caused by bacteria attack, whether existing in smear layer or emerges as the result of microleakage after restoration(8). brannstorm et al in 1972(9) suggested that, dentin should be sterilized before placement of any restorative material, because his study reported the prevalence of high frequency of bacteria beneath the composite restorations. many chemicals had been proposed for this purpose. recently, it is known that these chemical are irritating to the pulp when applied to the dentin surface (2).in this study, concepsis was used as a cavity disinfectant because in other studies chlorhexidine cavity disinfectant solutions displayed the most effective and the longest antibacterial activity, which will contribute to elimination of residual bacteria(3).single bond universal adhesive chosen in this study because it can be used as a total-etch adhesive system or self-etching adhesive. it was chosen to examine how chlorhexidine would affect two different smear layer management techniques in different sequences of bonding according to their clinical use. according to the results of this study, using chlorhexidine before bonding and after etching significantly decreased the microleakage when used single bond adhesive system as total etchtechnique. total-etch adhesive system operates by removing the smear layer and subjacent dentin, so, it is more reasonable to disinfect the dentin after etching (10). therefore, it is better not to rinse off the consepsis if it would not have an adverse effect on the bonding process (1, 3). some clinicians prefer to apply the disinfectant before acid etching, but the application sequence of the disinfectant depends on the generation of the bonding system (3).only a few researches have revealed an increased amount of microleakage when not rinsing chlorhexidine before dentin j bagh college dentistry vol. 29(1) march 2017 gingival microleakage restorative dentistry 19 bonding agent application.(3,11). gjermo in 1989(12) stated that chlorhexidine has a strong positive ionic charge making capable of easily binding to phosphate groups. it has strong affinity for tooth surface and this affinity is increased by acidetching. chlorhexidine also increases the surface free energy of enamel and can as well have a similar effect on dentin, so chlorhexidine could improve the sealing ability of the adhesives (13). so the results of this study was agree with results of agrawal et al 2013(1) and shafiei et al 2010(14) regarding the total-etch technique. on the other hand the results of this study regarding the selfetch technique would reveal decrease the microleakage when using chlorhexidine but not significantly different, the results of this study was agree with results of alikhani and heidari in 2015(8). self-etch dentin bonding systems affect the smear layer using a milder acidic monomeric primer with no rinse step necessitating the smear layer to be disinfected before using acidic primer (10). according to meirs and kresin 1996 (15)chlorhexidine washes did not remove the smear layer but did modify its appearance by removing loose smear debris. gultz et al in 1999 (16) found that chlorhexidine demineralize the dentin and envelop the collagen fibers and hydroxylapatite crystals. the scanning electron microscopic observations of their study revealed the presence of resin-tags in the consepsis treated group and the same finding would obtain by pattanaik and chandak in 2013(2). however, the results of this study are conflicting with other studies, as chlorhexidine had an adverse effect on syntac and prime(17), adeper easy one self -etch adhesive(1) and produced significantly higher microleakage when used with these bonding systems. pattanaik and chandak in 2013(2) concluded that the use of cavity disinfectant with resin composite restorations appears to be material specific, with regard to interaction with the ability of various dentin bonding systems to seal dentin.  within the limitations of this in-vitro study, it can be concluded that the use of consepsis as a cavity disinfectant has a definite beneficial role when used single bond adhesive system as etch and rinse technique rather than selfetch technique.  the results indicated that consepsis solution may not interfere with sealing ability of tested techniques. references 1. agrawal n, agrawal h, patel p: effect of cavity disinfection with chlorhexidine on microleakage of composite restorations using total and self etch single bottle adhesive systems: an in-vitro study. international j. of health care and biomedical research, 2013; 2(1): 43-47. 2. pattanaik n, chandak m: topic –the effect of three cavity disinfectant (chlorhexidine gluconate-based .consepsis ;benzalkonium chlorite-based, tubulicid red; sodium hypochlorite based-chlorcid v on the selfetch dentine bonding agent (adeper easy one ,3m espe ) under sem.(iosr-jdms), 2013; 8 (5) :84-89. 3. darabi f, eftekhari m: effect of chlorhexidine on microleakage of composite restorations. j of dentistry 2009; 6(1):16-22. 4. kapdan a, oztas n: effect of chlorhexidine on microleakage and gaseous ozone on microleakage and on the bond strength of dentin bonding agents with compomer restoration on primary teeth. j of dental sciences, 2015; 10: 46-54. 5. loguercio ad, roberto dbj, reis a, miranda grh: in vitro microleakage of packable composites in classii restorations. quit int 2004; 35(1): 29-34. 6. pazinatto fd, bruno bc, leorardo cc, maria ta: effect of the number of thermocycles on microleakage of resin composite restorations. pesqui odontol bras 2003; 17(4):337-41. 7. sensi lg, marson fc, monteiro sj: flowable composites as filled adhesive, a microleakage study. j cont dent prac. 2004; 5(4):1-5. 8. alikhani a, heideri s: evaluation of effect of chlorhexidine on microleakage of class-v composite restorations with dentin and enamel margins using two-stage self-etch adhesive after keeping them in water for six months. indian j of fundamental and applied life sciences 2015; 5 (s3): 139-150. 9. brannstorm m, nyborg h: pulp reaction to composite resin restoration. j prostht dent.1972; 27(2):181-9. 10. turkun m, ozata f, uzer e, ates m: antimicrobial substantivity of cavity disinfectants. gen dent 2005; 53(3): 182-6. 11. filler sj, lazarchik da, givan da, retief dh, heaven tj: shear bond strengths of composite to chlohexidine-treated enamel. amjdent 1994;7(2):858. 12. gjermo p: chlorhexidine and related compounds. j dent res 1989: 68(11):1602-8. 13. perdok jf, van der mei hc, genet mj, rouxhet pg, busscher hj: elemental surface concentration ratios and surface free energies of human enamel after application of chlorhexidine and adsorption of salivary constituents. caries res 1989;23(5):297-302. 14. shafiei f, memarpour m, khajeh f, kadkhoda z: the effect of chlorhexidine disinfectant on microleakage of adhesive systems in composite restorations .shiraz univ dent j, 2010; 11(3):228-234. 15. meirs jc, kresin jc: cavity disinfectants and dentine bonding: oper dent. 1996; 21(4):153-9. 16. gultz j, baylan r, schers w: antibacterial activity of cavity disinfectants. gen dent. 1999; 47(2): 187-90. 17. otulunoglu, h.ayhan, olmez a, h.bodur: the effect of cavity disinfectants on the microleakage in dentine bonding system. jclin pediatr dent. 1998; 22(4):299305. 18. singla m, aggarwal v,kumar n:effect of chlorhexidine cavity disinfection on microleakage in cavities restored with composite using a self-etching single bottle adhesive. conserv dent. 2011; 14(4): 374-377. abdulsalm.doc j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 11 the influence of shifting the class i cavity position prepared in posterior teeth buccally and lingualy on stress distribution (finite element analysis study) abdulsalm rasheed al-zahawi, b.d.s., h.d.d., m.sc., ph.d. (1) kale masoud m. saeed, b.d.s., m.sc.(1) hawzhen masoud m. saeed, b.d.s., m.sc. (1) abstract background: rehabilitation of the carious tooth to establish tooth structure integrity required cavity design that show a benign stress distribution. the aim of this study was to investigate the influence of the cavity position on the stress values in the reamining tooth structure restored with amalgam or resin composite. materials and methods: seven 2-d models of maxillary first premolar include class i cavity design was prepared, one sound tooth (a) 3 composite (b1, b2, and b3) and 3 amalgam (c1, c2, and c3). in design (bi and c1) the cavity position is in the mid distance between bacc-lingual cusp tip, design (b2 and c2) and (b3 and c3) shifted toward the buccal cusp and the lingual cusp for 0.5 mm respectively. one hundred n vertical load was applied and stress analysis was applied using ansys v14 software. results: the maximum von mises stress 585.35 mpa in the sound tooth and (899,46, 690.46, and 941.47) in central, buccal, and lingual cavities position filled with a composite restoration respectively. whereas, the highest stress (1540.37 mpa), (1233.09 mpa) and (1214.34 mpa) appears with a central, buccal and lingual cavities filled with amalgam respectively. conclusion: reestablishment of the stress level of maxillary premolars subjected to class i cavity preparations are cavity bacc-lingual position and restorative-system-dependent. key words: cavity position, class i, amalgam, composite, stress level. (j bagh coll dentistry 2015; 27(1):11-17). introduction rehabilitation of the carious tooth structure is to establish tooth structure integrity, functionally and aesthetically. tooth structure, cutting to remove the caries lesion and provide the amalgam restoration with adequate retention, resistance, and prevent recurrence caries, required to follow g.v. black cavity preparation principle (1). outline of amalgam cavity designs according to g.v. black principle needs to include all occlusal fissures, so that the bucc-lingual cavity postion should follwed the central fissure (1). the cavity design, preparation such as depth, width, line angle and positions of cavity designs, has great impact on stress distribution and fracture resistance of a tooth under occlusal load (2-3). studying the loss of tooth substance after cavity preparation for direct and indirect restorations and its relationship with fracture strength, found that the higher tooth structure loss result in lower fracture strength (4) . however, introducing a colored restoration and bonding system that helps the retention and reinforcing the reaming tooth structure, permit the dentists no more obey the g. v black principle for cavity preparation (5-8). although, the probability of tooth cracking and/or fracture is due to the degradation in restoration quality, the major causes for tooth fracture is related to remain tooth structure and stress distribution (9). (1)lecturer. department of conservative dentistry, school of dentistry, university of sulaimani. tooth fracture has become an obstacle to maintaining lifelong oral health. in that regard, the fracture of restored teeth continues to be a problem of increasing clinical concern. in an attempt to understand the mechanisms responsible for tooth fracture, the stress distribution within restored teeth that results from masticatory loading has been studied extensively. early investigations were conducted using photoelasticity to examine specific aspects of cavity design on the resulting stress distribution (4,10). 2d and 3d finite element stress analysis today considered one of the common investigation methods for stress analysis (10). although 2d fea not represent the actual model but it gives basic knowledge about the stress difference between the designs that can be used for practical and clinical studies. however, reviewing the articles found that mostly investigate on the cavity design which, include the width, depth and line angle shape, no study were conducted on posterior amalgam or composite restored cavity position bucco-ligually. the goal of this study was to investigate the influence cavity position on the stress values in reaming tooth structure restored with amalgam or resin composite. materials and methods seven 2-d models of maxillary first premolar include class i cavity design were prepared j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 12 according to filling materials, as shown in figure (1) one sound tooth (a) 3 composite (b1, b2, and b3) and 3 amalgam (c1, c2, and c3). design (a) control model, sound tooth structure without cavity preparation. design (bi and c1) the cavity position in the mid distance between back-lingual cusp tip, design (b2 and c2) the cavity position shifted toward the buccal cusp 0.5 mm, design (b3 and c3) the cavity position shifted toward the lingual cusp about 0.5 mm. the dimensions of the cavity is 2.5 mm width and 2.5 mm depth with all internal line angle is round. the dimensions and shape of maxillary first premolar were derived from the dental anatomy atlas (11). the material mechanical properties (modulus of elasticity and poisons ratio of enamel, dentin, pulp, composite, amalgam, periodontal ligament, alveolar bone and compact bone) were derived from previous articles (12). the contact surface between cavity wall and composite restoration will be defined as perfect contact surface, whereas between amalgam restoration and cavity wall will be flexible. all models were meshed and a 100 n load distributed on the buccal incline of the lingual cusp and lingual incline of buccal cusp as shown in figuer (2) table 1: mechanical properties of model parts results table 2, figure (3 and 4) revealed that there is an important influence of bucc-lingual cavity position and the materials used in the restoration on the stress and displacement value. the results showed that the maximum von mises stress 585.35 mpa in the sound tooth is lower compared with that of tooth with different class i cavity bucc-lingual position filled with amalgam or composite. the results predict that the maximum von mises stress is (899,46, 690.46, and 941.47) in central, buccal, and lingual cavity position respectively using composite restoration and bonding. whereas the highest stress (1540.37 mpa) appears with a central cavity filled with amalgam compared with buccal (1233.09 mpa) and lingual cavity position (1214.34 mpa) filled with amalgam respectively. materials type modulus of elasticity mpa poisson’s ratio reference enamel 41400 0,30 (13) dentin 18600 0.31 pulp 0,002 0.45 composite 3963 0.3 amalgam 48.3 0.35 pdl 0.0034 0.45 alveolar bone 13800 0.26 sponge bone 3000 0.35 figure 1: group designs to be tested in this study figure 1: cavity design and load application position j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 13 moreover, there is no important difference in the stress between buccal and lingual cavity position filled with amalgam.stress distribution patterns were concentrated at a load application point in the sound tooth, then distributed through all tooth structure. with composite restoration the maximum stress concentrated at the junction between the lingual cusp and restoration in central and lingual cavity position. whereas, at buccal cusp-restoration junction for buccaly position cavity. for amalgam restoration the maximum stress concentrated at the tip of the lingual cusp with a central cavity while in the buccal and lingual cavity position concentrated at buccpulpal and lingual-pulpal lines angle respectively. the results of the displacement vector sum predict that only the lingual cavity position filled with amalgam is very low compared with other groups and there is no important difference value between other groups as shown in table 2 and figure 4. the maximum displacement vector using composite restoration is at lingual cusp when the cavity position is central and lingual, while, located at the buccal cusp with vocal position cavity. discussion although experimental study data to verify the model and confirm the accuracy of the obtained solutions is mandatory, fea may assist to solve complicated biomechanical problems. in this study we tried to find the suitable posterior cavity position bucc-lingually that preserve sound tooth structure under vertical occlusal forces. for strengthening of the weakened teeth, it was suggested that the adhesive restorations preserve tooth structure (14-15). based on this idea, two fillings non-bonded amalgam and bonded composite were selected to fill the cavities in this study to compare how much resistance can be reconstructed in such cavity design. the present study indicated that posterior cavity preparation showed high von mises stress values in maxillary first premolar filled with amalgam and composite insequence compared with sound tooth structure. this may be due to discontinuities in the tooth structure filled with unbonded restoration (16-17). the results predict that the stress level was lower in all cavities filled with composite compared to the cavities filled with amalgam in different cavity position. this might be related to the bonding of the composite restoration to the tooth structure that retained part of the tooth structure continuity that lead the composite restoration to transmit part of stress to the tooth structure compared with amalgam. looking to the stress pattern, the maximum stress concentrated at the load point application and then distributed through tooth structure with different levels, in sound tooth and teeth filled with a composite restoration. this may be due to continuities in the model structure, because the interface between tooth structure and composite restoration simulated as a perfect contact. this result is in agreement with a study, which investigate the stress distirbution in tooth structure and found that the relative high stress values were computed at the surface under loading (18). whereas, the stress with an amalgam restoration concentrated at the angle between the pulpal floor and buccal or lingual wall according to the cavity position. this might increase the possibility of initiating the fracture plane from this angle toward the external surface of tooth structure (17). the increase in the stress in the tooth stucture in some area leave the tooth to be more susceptible to fracture (4). regarding the displacement sum the results shown that it is low with the amalgam and particularly lingual position cavity, which may be due to discontinuities in the model structure. in the present study, the only cavity position that restored the stress level to be nearly to that of the intact teeth is buccal position cavity filled with a composite. this result predicts that the buccal position cavity filled with a composite is less susceptible to fracture compared with other cavity position and this might be due to 1) bonding between the tooth structure and composite and this is in agreement with results of studying the fracture of posterior teeth in adult (19) . furthermore, studying the restored tooth by a combined bonded enamel and dentin with composite showed significant higher fracture resistance compared with tooth prepared but not restored (20). studying the fracture resistance of posterior teeth restored with modern restorative materials found that the tooth restored with admira composite and bonding showed no significant difference when compared with the unprepared teeth(21). 2) it is well known that palatal cusp of maxillary premolars fractures more frequently than buccal cusp (4, 22-23). the buccal position cavity filled with composte should contribute to better biomechanical behavior of tooth-restoration complex, consequently might provide the long-lasting clinical results (13). a fe analysis study on both amalgam and composite showed similar stress distribution for mod cavity, however the stress recorded with composite was higher than that restored with amalgam (13). the results, conduct that selection of the cavity position and restoration type is important to obtained a preservation of tooth structure. preservation of sound tooth structures j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 14 is the primary goal of modern restorative dentistry. due to their unfavorable anatomy, maxillary premolars with cavities preparation are at great risk of fracturing if restored without regarding protective principle (4, 24). in conclusion, based on the numerical simulations applied in this study and analysis results predict that reestablishment of the stress level of maxillary premolars subjected to class i cavity preparations is cavity bucc-lingual position and restorative-system-dependent. references 1. roberson t, heymann ho, swift jr ej. sturdevant's art and science of operative dentistry. 5th ed. st. louis: elsevier health sciences; 2006. 2. ivana k, darko v, larisa b, ognjan l. influence of cavity design preparation on stress values in maxillary premolar: a finite element analysis. croat med j 2012; 53:568-76. 3. lin c-l, chang w-j, lin y-s, chang y-h, line y-f. evaluation of the relative contributions of multifactors in an adhesive mod restoration using fea and the taguchi method. dent mater 2009; 25(9):1073-81. 4. mondelli j, sene f, ramos rp, benetti ar. tooth structure and fracture strength of cavities. braz dent j 2007;18(2):134-8. 5. bowen r. adhesive bonding of various materials to hard tooth tissues v: the effect of a surface active comonomer on adhesion to diverse substrate. j dent res 1965; 44: 1369. 6. gerard k, imarco f. the science of bonding from first to sixth generation j am dent assoc 2000; 131. 7. fonseca rb, correr-sobrinho l, fernandes-neto aj, quagliatto ps, soares cj. the influence of the cavity preparation design on marginal accuracy of laboratory-processed resin composite restorations. clinical oral investigation 2008;12(1):53-9. 8. soares pv, santos-filho pcf, martins lrm, soares cj. influence of restorative technique on the biomechanical behavior of endodontically treated maxillary premolars. part i: fracture resistance and fracture mode. j prosthet dent 2008; 99(1): 30-7. 9. cosmin s, liviu m, anghel c. asymptotic stress field for the interface between teeth and different restorative materials. comput mater sci 2012; 59:57-64. 10. romeed sa, fok sl, wilson nhf. a comparison of 2d and 3d finite element analysis of a restored tooth. j oral rehabil 2006; 33(3): 209-15. 11. nelson sj. wheeler's dental anatomy, physiology and occlusion. 9th ed. st. louis: elsevier health sciences; 2009. 12. aykul h, toparlı m. a comparison of the stress analysis of an unrestored and restored tooth with amalgam and composite resin mathematical and computational applications 2005;10(1):89-98. 13. iqbal m, prabhakar a. biomechanical stress analysis of mandibular first premanent molar; restored with amalgam and composite resin: a computtrized finite element study. international j clinical pediatric dentistry 2010; 3(1): 5-14. 14. bremer b, geurtsen w. molar fracture resistance after adhesive restoration with ceramic inlays or resin-based composites. am j dent 2001;14(4): 216-20. 15. hassan t, amir g, atoosa d, sara r. fracture resistance of teeth restored with direct and indirect composite restorations. j of dent of tehran uni med sci 2013;10(5):417-25. 16. pereira jr, mcdonald a, petrie a, knowles jc. effect of cavity design on tooth surface strain. j prosthet dent 2013;110(5): 369-75. 17. cobankara f, unlu n, cetin a, ozkan h. the effect of different restoration techniques on the fracture resistance of endodontically-treated molars. operative dentistry 2008; 33(5): 526-33. 18. chanyiu p, chak yt, bo g. stress analysis of a class ii mo-restored tooth using a 3d ct-based finite element model. inter j biomater 2012; 2012: article id 657519. 19. eakle w, maxwell e, braly b. fractures of posterior teeth in adults. j am dent assoc 1986;112: 215-8 20. eakle ws. fracture resistance of teeth restored with class ii bonded composite resine. j dent res 1986; 65(2): 149-53. 21. ibrahim hm, shehata sh. fracture resistance of posterior teeth restored with modern restorative materials. j biomed res 2011; 25(6): 418-24. 22. chun-li l, yan-hsiang c, liuc-perngr. multifactorial analysis of a cusp-replacing adhesive premolar restoration: a finite element study. j dent. 2008; 36(3):194-203. 23. soares pv, santos-filho pcf, martins lrm, soares cj. influence of restorative technique on the biomechanical behavior of endodontically treated maxillary premolars. part i: fracture resistance and fracture mode. the journal of prosthetic dentistry. 2008; 99(1): 30-7. 24. bitter k, meyer‐lueckel h, fotiadis n, blunck u, neumann k, kielbassa am, et al. influence of endodontic treatment, post insertion, and ceramic restoration on the fracture resistance of maxillary premolars. inter endo j 2010; 43(6): 469-77. j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 15 table 2: maximum von mises stress and displacement vector sum filling materials cavity position von mises stress (mpa) sum displacement (mm.) sound tooth sound tooth 585.35 0.590533 composite central 899,46 0.66269 buccal 690.46 0.608534 lingual 941.47 0.666677 amalgam central 1540.37 0.599928 buccal 1233.09 0.592125 lingual 1214.34 0.156054 figure 2: maixmum von mises stress recorded according to the model in mpa figure 3: displacement vector sum in mm according to cavity position and filling materials used. j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 16 figure 4: stress pattern of the maximum von mises stresses according to the model. a sound tooth structure, b1,b2, and b3 are of composite restoration in central, buccal and lingual cavity position respectively. c1, c2, and c3, are of amalgam restoration in central, buccal and lingual cavity position respectively. b3 b2 b1 c3 c2 c1 a j bagh college dentistry vol. 27(1), march 2015 the influence of restorative dentistry 17 figure 5: pattern of the displacement vector sum, according to the model. a sound tooth structure, b1,b2, and b3 are of composite restoration in central, buccal and lingual cavity position respectively. c1, c2, and c3, are of amalgam restoration in central, buccal and lingual cavity position respectively. a b3 b2 b1 c1 c2 c3 ibtihal.doc j bagh college dentistry vol. 27(1), march 2015 evaluation the effect oral diagnosis 111 evaluation the effect of hyaluronic acid on bone healing process in rabbits (immunohistochemical study for tgf-β) ibtihal h. radhi, b.d.s. (1) nada m. al-ghaban, b.d.s., m.sc., ph.d. (2) abstract background: bone augmentation techniques are commonly employed in medical fields. this biomaterial system must be readily available, easily applicable by minimally-invasive technique and able to release an osteoinductive growth factor. such a system will be able to engineer new bone formation locally at the site of injection. hyaluronic acid has osteogenic potential that can be exploited not only for repairing bone defects but also for providing transplantable bone for the reconstruction of a variety of bone defects. the aims of this study were to evaluate the effects of hyaluronic acid gel on bone healing by immunohistochemical estimation of transforming growth factor beta 3 in experimental and control groups. materials and methods: thirty two new zealand male rabbits were used in this study .two intra bony holes were made for each rabbits on the right and left buccal side of the upper diastema. the right hole was filled with hyaluronic acid gel (experimental one), while the left hole was left for normal healing (control one). the rabbits were randomly divided and sacrificed at 1, 2, 3 and 6 weeks post operatively. immunohistochemical test for the expression of tgf-β3 were performed on bone specimens of both control and experimental groups at all healing interval. results: immunohistochemical examination of this study revealed that the hyaluronic acid treatment increased the positive expression of tgf-β3by osteoblasts, osteocytes and bone marrow stromal cells especially in 1 and 2 weeks intervals than that observed in control one. conclusions: the present study illustrated that the hyaluronic acid was osteoconductive material that enhance osteogenesis and accelerated the bone healing process. key words: bone augmentation, osteoinductive, growth factor, hyaluronic acid. (j bagh coll dentistry 2015; 27(1):111-116). introduction bone defects in oral and craniofacial tissues are a clinical challenge and can be the result of trauma, tumor resection or congenital malformations (1). the golden standard for reconstruction is autologous bone grafts, but bone may not always be readily available and donor-site morbidity might follow. alternatives to autologous tissue are sought in the field of tissue engineering, where a range of biomaterials, searching to engineer the missing tissue (2). biomaterials can be divided into four different groups comprising inorganic materials, naturally-derived polymers, synthetic polymers and composite materials (3). biomaterials of different origins as natural and synthetic ones have different mechanisms of host response. it should be stable, biocompatible; ideally osseoinductive and conductive, porous and similar to biological bone mechanically (4). hyaluronic acid is a naturally-derived polymers biomaterial. it is a major component of the extra cellular matrix (ecm) and present in nearly every mammalian tissue and fluid. it plays a role in wound healing and it has been found in high concentrations in the early fracture callus, in lacunae surrounding hypertrophic chondrocyte in the growth plate and (1) master student. department oral diagnosis, college of dentistry, university of baghdad (2) assistant professor, department oral diagnosis, college of dentistry, university of baghdad. in the cytoplasm of osteoprogenitor cells (5). hyaluronic acid (ha) has osteoconductive potential; it accelerates the bone regeneration by means of chemotaxis, proliferation and successive differentiation of mesenchymal cells. ha may act as biomaterial scaffold for other molecules, such as bmp-2 and tgf-β, used in guided bone regeneration techniques and tissue engineering research (6). a number of growth factors have been shown to be expressed during different phases of experimental bone-healing. among these growth factors is transforming growth factor-beta (7). transforming growth factor-beta, the largest source of which is bone, has been implicated in osteoblast proliferation and differentiation and is expressed at high levels during bone growth and development with an adequate blood supply (8). materials and methods thirty two new zealand male rabbits, weighting (1.5– 2kg), aged (6-12) months were usedin this study. two intra bony holes were made for each rabbits on the right and left buccal side of the upper diastema. the right hole was filled with 0.1ml hyaluronic acidgel (experimental one).while the left hole was left for normal healing (control one).the sample divided into four groups, eight rabbits are sacrificed at four intervals 1week, 2weeks, 3 weeks and 6weeks respectively. all tissue j bagh college dentistry vol. 27(1), march 2015 evaluation the effect oral diagnosis 112 specimens, experimental and controls were fixed in 10% neutral formalin and processed in a routine paraffin blocks after complete decalcification of bone. each paraffin-embedded specimen had serial sections were prepared as follows: 4μm thickness sections were mounted on clean glass slides for routine h&e staining procedure from each block of all studied sample. other 4 sections of 4μm thickness were mounted on positively charged microscopic slides for immunohistochemical localization oftgf-β. the procedure of the ihc assay was carried out in accordance with the manufacturer instructions of anti-tgf-β polyclonal antibody (ab15537) abcam uk and detection kits system (ab80436) abcam uk. results expression of tgf-βfindings at 1 week duration control group immunohistochemical staining with tgf-β polyclonal antibody at one week duration showed weak positive expression infat cells, fibroblast, progenitor cells and osteoblasts. negative expression of tgf-β is seen in osteoid tissue figure (1). figure 1: positive localization of tgf-β in defect site of control group for 1 week duration in progenitor cells (arrows), fat cells (fc) and fibroblast (fb). dab stain with counter stain hematoxylin x20 experimental group experimental group at 1 week duration labeled with tgf-β antibody shows positive expression of tgf-β in progenitor cells, osteoblasts, and osteocytes. negative expression of tgf-β in bone spicules and osteoid tissue figure (2). figure 2: immunohistochemicalview of ha treated group at1 week interval show positive expression of tgf-β in osteoblast (ob),fat cells(fc)and negative expression in bone spicules (bs). dab stain with hematoxylin counter stain x40. at 2 weeks duration control group control defect area at 2weeks duration shows positive localization of tgf-β in fibrous connective tissue, osteoblasts, osteocytes, osteoclasts and negative expression of tgf-β in bone trabeculeafigure (3). figure 3: immunohistochemical view for bone healing defect (control) at 2 weeks duration shows positive expression of tgfβ in osteocytes, osteoclasts (ocl). dab stain with hematoxylin counter stain x40. experimental group immunohistochemical view of defect area treated with hyaluronic acid at 2 week duration shows positive expression of tgf-β in osteoblasts, osteocytes, osteoclasts.also positive localization of tgf-β in fibroblasts cell,endothelial cells and progenitor cells in bone marrow tissue figure (4). fc fc bs ob j bagh college dentistry vol. 27(1), march 2015 evaluation the effect oral diagnosis 113 figure 4: immunohistochemical view of defect area treated with ha at 2 week duration shows positive expression of tgfβ in osteoblasts (ob), osteocytes (oc) and osteoclasts (ocl). dab stain with hematoxylin counter stain x40. at 3 weeks duration control group immunohistochemical view of control defect area at 3weeks duration shows positive expression of tgf-β in progenitor cells, endothelial cells, osteoblasts, osteocytes, osteoclasts cells and negative expression of tgfβ in bone trabeculea figure (5). figure 5: control defect area at 3weeks duration shows positive expression of tgfβ in preosteocytes (arrows), osteocytes (oc) and osteoclasts (ocl). dab stain with hematoxylin counter stain x40. experimental group immunohistochemical view of experimental defect area at 3 weeks duration shows positive expression of tgf-β in progenitor cells, osteoblasts, osteocytes, osteoclasts and negative expression of tgf-β in bone trabeculea figure (6). figure 6: view of defect area treated with hyaluronic acid at 3 week duration shows positive expression of tgf-β in osteoclasts (ocl) and osteocytes (oc). dab stain with hematoxylin counter stain x40. at 6 weeks duration control group immunohistochemical view of control defect area at 6weeks duration shows positive expression of tgf-β in bone marrow stromal cells in marrow tissue, osteoblasts, osteocytes and negative expression of tgf-β in bone trabeculea figure (7). figure 7: view of control defect area figure 7: view of defect area of control group at 6 weeks duration shows positive immunohistochemical localization of tgf-β detected by bmsc in marrow tissue (arrows) and haversian canal (hc). dab stain with hematoxylin counter stain x10. experimental group experimental defect area treated with hyaluronic acid at 6 week duration labeled with tgf-β antibody shows positive expression of tgf-β in osteoblasts which lined the havarsian canal and in osteocytes which embedded in osteon figure (8). j bagh college dentistry vol. 27(1), march 2015 evaluation the effect oral diagnosis 114 figure 8: view of defect area treated with hyaluronic acid at 6 week duration shows positive localization of tgf-β in osteocytes (oc) and in osteoblasts cell which lined the havercian canals. dab with hematoxylin counter stain x40. immunohistochemical scoring for expression of cells for tgf – beta 1-bone marrow stromal cells (bmsc) there was decrease in positively stained bmsc score mean values for tgf – beta with the time for both groups with the increase in mean values for ha treated group than that of the control one in all intervals, as shown in figures (9). according to the t-test (table 1) which illustrates highly significant differences between experimental and control groups in positive expression bmsc for tgf-β in all intervals. figure 9: comparison the mean of positive (bmsc) expressed tgf-β with time of healing for both groups. table 1: groups' comparison for positive stromal cell expressed tgf-β in each duration 2bone cells the highest mean value for positive expression for tgf-β by osteoblasts and osteocytes were seen in 2 weeks duration for ha treated group .while the highest mean value for positive expression of osteoclast was seen in the 2 weeks for control group figures (10,11,12). figure 10: comparison the mean of positive osteoblasts for tgf-β with time of healing for control and experimental groups. figure 11: comparison the mean of positive osteocytes for tgf-β with time of healing for control and experimental groups. variables duration groups' comparisons d.f. = 7 t-test p-value bone marrow stromal cells (bmsc) 1 week -22.12 0.000 (hs) 2 weeks -13.53 0.000 (hs) 3 weeks -11.97 0.000 (hs) 6 weeks -9.26 0.000 (hs) j bagh college dentistry vol. 27(1), march 2015 evaluation the effect oral diagnosis 115 figure 12: comparison the mean of positive osteoclasts with time of healing for control and experimental groups. according to t-test (table 2), showed highly significant differences between both groups in all interval in the number of positive expression of osteoblasts for tgf-β. the positive osteocytes number showed significant difference between control and experimental groups at 3 weeks interval and high significant difference between both groups in other periods. while the results showed nonesignificant differences between control and experimental groups for positive expression of osteoclasts for tgf-β in all intervals. table 2: groups' comparison for positive bone cells expressed tgf-β in each duration discussion tgf-β regulates a broad range of biological processes, including cell proliferation, cell survival, cell differentiation, cell migration, and production of extracellular matrix (ecm) (9,10). the combined actions of these cellular responses mediate the global effects of tgf-β on immune responses, angiogenesis, wound healing, development, and bone formation (11). the cell types in which tgf-beta could be detected immunohistochemically varied with time: first inflammatory cells, then cells in late hypertrophying and calcifying cartilage, then osteoblasts and bone marrow granulocytes stained for tgf-beta. tgf-β is expressed from the very early stages throughout roles as a potent chemotactic factor of mesenchymal progenitor cells and macrophages to the wound healing site, induction of their subsequent proliferation and stimulates production of the extracellular collagenous matrix by osteoblasts (12). the current results showed that bmsc cells had a highly positive expression for tgf-β polyclonal antibody at early stage of bone healing (1 and 2 weeks), and the expression decreased in late stage (3 and 6 weeks) in both groups. this result was in agreement with jaafar (13).tgf-β has a positive function in the early differentiation stage of osteoprogenitor cells but it has an inhibition effect on differentiation in the terminal stage (14). at one week duration both groups shows positive localization of tgf-beta in numerous active mesenchymal stromal cells within marrow tissue. also bone defect area showed positively stained formative cells that are irregularly arranged within primitive osteoid tissue and in fibroblasts but ha-treated group shows additional positive tgf-beta expression in some osteoblasts which lined bone spicules than that of control one. after 2 and 3 weeks interval, tgf-beta expression was illustrated in osteoblasts which lined the bone trabeculea and in osteocytes for both groups. at 6 weeks interval, control and experimental groups showed moderate positive tgf-beta expression in osteoblasts lined the havarsian canals and osteocyte cells in new bone. these findings agreed with others (15,16). tgf-β is released by platelets into the bone defect hematoma, and then synthesized by osteoblasts and chondrocytes throughout the healing process (17).this explains the increase of tgf-β concentrations within the first 2 weeks after bone defect in the present study. this increase may partly be attributable to the absorption of cytokines from the fracture site into the circulation. finally the present study illustrated that the hyaluronic acid was osteoconductive material that enhance osteogenesis and accelerated bone healing process by promoting cell adhesion and osteoblast differentiation. variables duration groups' comparisons d.f. = 7 t-test p-value osteoblasts 1 week -22.56 0.000 (hs) 2 weeks -21.36 0.000 (hs) 3 weeks -14.54 0.000 (hs) 6 weeks -24.59 0.000 (hs) osteocytes 1 week -24.18 0.000 (hs) 2 weeks -29.57 0.000 (hs) 3 weeks 2.50 0.041 (s) 6 weeks 9.75 0.000 (hs) 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invest dermato 2002; 118:211–215. 10. siegel pm, massague j. cytostatic and apoptotic actions of tgf-β in homeostasis and cancer. nat rev cancer 2003; 3:807-21. 11. gorelik l, flavell ra: transforming growth factor-β in t-cell biology. nat rev immunol 2002; 2: 46–53. 12. dimitriou r, tsiridis e, giannoudis pv. current concepts of molecular aspects of bone healing. injury 2005; 36:1392-404. 13. jaafar mk. immunohistochemical evaluation of vascular endothelial growth factor and transforming growth factor-beta on osseointegration of cpti implant radiated by low level laser therapy. j bagh coll dentistry 2014; 26(2): 7986. 14. spinella-jaegle s, roman-roman s, faucheu c, dunn fw, kawai s, gallea s, stiot v, blanchet am, courtois b, baron r, rawadi g. opposite effects of bone morphogenetic protein2 and transforming growth factor-beta1 on osteoblast differentiation. bone 2001; 29: 323. 15. al talabani mah. the effect of autologous bone marrow-derived stem cells with estimation of molecular events on tooth socket healing in diabetic rabbits (immunohistochmical study). j bagh coll dentistry 2013; 25(1): 89-95. 16. chen yj, wurtz t, wang cj, kuo yr, yang k d, huang hc, wang fs. recruitment of mesenchymal stem cells and expression of tgf-β and vegf in the early stage of shock wave-promoted bone regeneration of segmental defect in rats. j orthop res 2004; 22: 526–534. 17. sarahrudi k., thomas a, aharinejad a. elevated transforming growth factor-beta 1 (tgf-β1) levels in human fracture healing. elsevier injury 2011; 42(8): 833–7. الخالصة سھلة التطبیق بأقل ضرر ,البدائل یجب ان تكون متوفرة وھذه. الطبیةإن تقنیة تعویض العظام باستخدام نظام بدائل عظمیة اصبحت شائعة االستخدام في الكثیر من المجاالت :الخلفیة حمض الھیالورونیك یتمیز بخاصیة تكوین العظام التي یمكن . لتحفیز العظمي و قادرة على تكوین عظام جدیدة موضعیا في موقع الحقنامالنسیجي ممكن ولھا القدرة على اطالق ع وكانھدفھذه الدراسة ھو تقیم تأثیر حمض الھیالورونیك . وفیر غرس عظمیة تستخدم إلعادة بناء انواع مختلفة من عیوب العظاماستخدامھا لیس فقط إلصالح عیوب العظام ولكن أیضا لت .فیمجامیعاالختباروالسیطرة (tgf-β3) على التئام العظم من خالل دراسة شفاء العظام باستخدام التقییمالمناعیالنسیجیالكیمیائي لعاملتحواللنمو الثقب األیمن ملء ,تم عمل ثقبین لكل أرنب على الجانب األیمن واألیسر من الفك العلوي, تم استخدام اثنان وثالثون من ذكر األرانب النیوزلندي الناضج:والموادالمستخدمةطریقةالعمل , اسبوع(تم تقسیم االرانب عشوائیا الى أربع فترات حسب وقت القتل , رنةالھیالورونیك لكي یستخدم كعینة تجربة و ترك الثقب األیسر لكي یشفى تلقائیا ویستخدم كعینة مقا حمضبھالم لجمیع الحیوانات ولكل )tgf-β3(وتم استخدام فحوصات نسیجیة مناعیة كیمیاویة القتفاء ظھور مستقبالت عامل تحول النمو,بعد اجراء العملیة)ثالثة أسابیع و ستة أسابیع, اسبوعان .مراحل االلتئام على الظھور في tgf-β3الھیالورونیك یزید من مستوى التعبیر االیجابي لعامل النمو المحول حمض ت نتائج الفحص الكیمیائي النسیجي المناعي ان العالج باستخداماظھر:النتائج .فاء العظم مقارنة بتلك التي لوحظت في مجموعة المقارنةالخالیا البانیة للعظم والخالیا المكونة للعظم وخالیا انسجة نخاع العظم خاصة في االسبوع االول والثاني من فترات ش ظم اكثر من عملیة الشفاء اظھرت ھذه الدراسة ان حمض الھیالورونیك ھو مادة تظھر خاصیة توصیل عظمي ولھا القدرة على تعزیز تكوین العظم وتسریع عملیة الشفاء الع:االستنتاج . الفسیولوجیة الطبیعیة .حمض الھیالورونیك,عامل النمو , عظميلتحفیز الامالع,ض العظامتعوی:الكلماتالرئیسیة j bagh college dentistry vol. 28(4), december 2016 gingival marginal the restorative dentistry 43 gingival marginal leakage of different tooth colored materials combination as an intermediate layer in class ii composite restoration (a comparative in vitro study) aseel a. salih, b.d.s. (a) zainab m. hussain, b.d.s., m.sc. (b) abstract background: the aim of this in vitro study was to evaluate and compare the microleakage between vertise flow t m composite material and other conventional (filtek z250, riva light cure and sdr) composite materials when restoring cii mesial box only cavity at gingival margin through die penetration test materials and methods: forty maxillary first premolars were prepared with class ii box design only cavities. samples were divided into four groups of ten teeth according to material used: group i (filtekz250 only). group ii (sdr+filtekz250). group iii (vertise flow +filtekz250). group iv (riva light cure+ filtekz250). after 24 hrs. immersion in 2% in methylene blue, samples were sectioned and micro leakage was estimated. results: none of the materials showed zero score for dye penetration. micro leakage percentage in group iii had lowest value; followed by group iv then group i while in group ii had highest value of micro leakage conclusion: all the materials show micro leakage at variable degrees and that the microleakage degree depend on materials type vertise flow is a promising material to be used in clinic as it saves both time and effort and gives high degree of performance from the microleakage point of view. key words: microleakage, self-adhesive composites, flowable composites. (j bagh coll dentistry 2016; 28(4):43-48) introduction increasing the demand for highly esthetic tooth filling material, with less loss of tooth substance during cavity preparations, has increase the need to tooth colored restoration material for the posterior teeth in last few years. for packable composites, they were claimed to be stress relieving. the handling properties were improved, but they had many problems including (marginal micro leakage due to their high polymerization shrinkage, low wear resistance, body of restoration fracture, voids, and insufficient proximal contact sensitivity after placement). the rate of success for these was relatively high in short periods of time when clinically evaluated, but start to drop after five years (1). the initial stresses of shrinkage of the composite resin, coefficient of thermal expansion difference between of materials and tooth, cervical area inaccessibility, in particular, are the main problems of bonding to the cervical substrate for class ii cavities, and factors that are responsible for micro leakage problems (2). to achieve good marginal quality it is preferred to place the resin-based composite materials in layers not more than (2 mm) to prevent distortion of the cavity wall and securing adhesion to dentin (3). in this study, we evaluate the microleakage between self-adhesive, self bonded composite material and other three conventional composite (a) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (b) assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. type when restoring cii proximal cavities. many techniques have been used to decrease the amount of microleakage, like (applying a thicker adhesive coat below the composite resin, using the incremental technique, resin matrix changing and production of composite resins having small polymerization shrinkage), may help reduce the polymerization shrinkage and the stress resulted (4). materials and methods forty sound maxillary first premolar teeth, non-carious, and non-restored with regular occlusal anatomy and similar crown size sound with absence of visible hypoplasty, defects, and cracks on visual examination using magnifying lens device (5). all the teeth were cleaned carefully for any calculus deposits with air scalarand teeth were polished with pumice (6). all the teeth had been stored in distilled water at room temperature until use prior to the experimental procedures, a restoration template was prepared acrylic teeth first molar and second premolar were inserted in self–cure acrylic resin, then a hole for the experimental tooth was drilled representing the space of upper first premolar. these were put in one piece of self-cure acrylic resin and acrylic canine was inserted in a second piece of the cold cure acrylic resin alongside other teeth. a screw was used to position the teeth in contact with each other (figure1) (7). j bagh college dentistry vol. 28(4), december 2016 gingival marginal the restorative dentistry 44 figure 1: template for teeth fixation. forty sound maxillary first premolar teeth were divided into four main groups, (10 teeth) for each.named according to the material they are filled with as follow: group i:10 teeth restored with filtk z250 in 3 layers 2.0mm for each; group ii: 10 teeth restored with4mm sdr composite and covered with 2.0mm filtk z250 composite; group iii: 10 teeth restored with 4.0mm vertisetm folw composite in three layers (0.5, 1.5, 2.0mm) and covered with 2.0mmfiltk z250 composite; group iv: 10 teeth restored with4.0mm riva risen modified glass ionomer cement 2.0mm for each layer and covered with 2.0mm filtk z250 composite. for standardization, a modified dental surveyor was used in such a way so that the long axis of the bur was kept parallel to the long axis of the tooth during the preparation (8). all cavosurface line angles are not beveled (9) on each tooth, a standardized class ii box only cavity was prepared in the proximal surface (3mm bucco-lingual width, 6mm height, and 2mm mesiodistal depth),margins are (1mm) above cemento-enamel junction (10). for filtek™ z 250 group, the cavities were etched with 37% phosphoric. then 5th generation bonding agent (adaper single bond 2) (3m, usa)was applied according to the manufacturer instructions then cured for 10 second with a light cure device (type led, light intensity: 856mw/cm2), the cavity was filled with filtek™ z250 in three separated layers of 2mm and was cured for 20 second for each layer then finally finished. for the sdr group etching followed by 5th generation bonding agent adaper single bond 2 was applied then cavity was filled with sdr in bulk increment (4mm) according to manufacturer instructions and cured then we completed by 2mm of filtek z250. for vertise flow group, vertise flow was dispensed in to the preparation with dispensing tip and by the fine brush a thin layer of (0.5 mm) was brushed into cavity wall with moderate pressure for 15 sec and the excess material was removed then light cured for 20 second then a second layer of (1.5mm) was applied and light cured for 20 second and a third layer of the vertise flow of 2mm thickness was applied and also light cured for 20 sec to complete 4mm of vertise flow then layer of 2mm of filtek z250 was applied to finish the restoration. for riva light cure, etchantagent (37% phosphoric acid then washed thoroughly, excess water was removed but not completely and tooth was left glistening.after that the capsule was activated by pushing the plunger until it was flushed with the body then capsule was placed immediately into the amalgamator (ultramat 2) and titrated for 10 second, then immediately the capsule was removed and placed into the riva applicator 2 then it carefully extruded in to the cavity for not more than 2mm for each layer and light cured for 20 second and finally a third layer of 2 mm filtek z250 to complete the filling of the cavity. after specimens were stored in distilled water at 37°c for 7 days (6) all specimens were thermocycled for 500 cycles, at 5° to 55°c, with a 30 second dwell time (11,12) the thermocycling procedure was done by thermocycler machine which is especially fabricated for this study. then specimens were subjected to the microleakage testing procedures. apical foramina were sealed with resin modified glass ionomer cement. in order to prevent dye penetration into the dentinal tubules or the lateral canals (13), the teeth were coated with two layers of nail varnishexcept for an area approximately 1 mm around the gingival margin of the restorations. this procedure was intended to prevent the penetration of dye into unwanted areas (6,14). the teeth were then immersed in 2% methylene blue for 24 hours at 37°cinside medical incubator. after removal from the dye solution, the teeth rinsed with running tap water. the root was embedded in chemically cured acrylic resin with the long axis of tooth by dental surveyor up to (2 mm) apical to the cementoenamel junction (cej) to facilitate handling during sectioning procedures and by using special sectioning bur and dental engine. specimens were sectioned in mesio–distal direction at the center of the restorations. the fragment that exhibited greater dye leakage was evaluated and the other was discarded (15). the extent of dye penetration was scored according to a five-points scale (16) the cervical marginal micro leakage was recorded based on the following criteria:0: no dye penetration, 1: dye j bagh college dentistry vol. 28(4), december 2016 gingival marginal the restorative dentistry 45 penetration less than half the length of the gingival floor, 2: dye penetration greater than half, up to the whole length of the gingival floor, 3: dye penetration the whole length of the gingival floor plus up to half of the axial wall, 4: dye penetration the whole length of the gingival floor plus greater than half the axial wall and existence of lateral microleakage at dentin tubules (17). the data was analyzed using kruskal-wallis test (p ≤ 0.05) at 95% confidence level to detect the significant differences among the groups. further analysis with mann-whitney u-test was conducted for pair-wise comparisons among groups (p ≤ 0.05) at 95% confidence level. results the microleakage percentage in vertise flow group has lowest value (30% score zero, 20% score 1, 40% score 2, 40% score 3 and 0% score 4), while in sdrgroup has highest value (100% for score 4). the statistical analysis of data by kruskal-wallis h non-parametric test revealed highly significant difference (p < 0.001) among the groups since the p-value is less than 0.05, there is a statistically significant difference amongst the medians at the 95.0% confidence level to determine which mean are significantly different from which others, all groups show significance at (p<0.05) except sdr filtek z250 did not show any significance. mann-whitney u test shows that: the sdr group is in significant difference with vertise flow and riva light cure, but did not show any significance with filtek z250 group, vertise flow is significant difference with all groups, riva light cure is in significant difference with filtek z250. table 1: the scores percentages for experimental groups score filtek z250 group sdr group vertise flow group riva light cure group 0 0 (0%) 0 (0%) 3 (30%) 0 (0%) 1 0 (0%) 0 (0%) 2 (20%) 0 (0%) 2 0 (0%) 0 (0%) 4 (40%) 2 (20%) 3 3 (30%) 0 (0%) 1 (10%) 6 (60%) 4 7 (70%) 10 (100%) 0 (0%) 2 (20%) total 10 10 10 10 mean 3.70 4.00 1.30 3.00 sd 0.483 0.000 1.059 0.667 table 2: statistical analysis of data by kruskal-wallis test statistical value p-value kruskal -wallis 29.3046 0.000 table 3: descriptive statistics of microleakage for groups groups sample no. mean median q1 median q2 median q3 minimum maximum filtek z250 10 3.7 3.0 4.0 4.0 3.0 4.0 riva 10 3.0 2.75 3.0 3.25 2.0 4.0 sdr 10 4.0 4.0 4.0 4.0 4.0 4.0 vertise flow 10 1.3 0.0 1.5 2.0 0.0 3.0 table 4: mann-whitney u test contrast mann-whitney p value sig. sdr vertise flow 0.000 0.0000 s sdr filtek z 250 35.000 0.0671 n.s sdr riva 10.000 0.0005 s vertise flow filtek z 250 1.500 0.0002 s vertise flow riva 9.000 0.0013 s filtek z 250 riva 22.000 0.0193 s discussion the statistical analysis showed that the kruskal-wallis test had a significant relation between the scores of penetration and the restorativematerials by their sequences of the dye penetration. scores from lowest to highest were: vertise flow, riva light cure rmgic, filtek z250 and sdr.the highest degrees of microleakage were observed in flowable sure full sdr composite. the possible explanation for these j bagh college dentistry vol. 28(4), december 2016 gingival marginal the restorative dentistry 46 results is that sdr material is a flowable material with 68% wt filler loading and low filler content leading to a low modulus of elasticity, thus reducing curing stresses. yet, the lightly filled resin undergoes greater polymerization shrinkage (18). the reduced filler load may also impair the resistance to deformation of the restorations during function. due to their inferior mechanical properties, this is agree with baroudi (19) who said that flowable composite resins are generally not recommended as stand-alone restorative materials especially in cavities with high-stress occlusal function. the higher matrix content may also contribute to increased water solubility, possibly affecting the restorations long-term performance. the reduced filler load may also impair the resistance to deformation of the restorations during function. due to their inferior mechanical properties, flowable composite resins are generally not recommended as stand-alone restorative materials especially in cavities with high-stress occlusal function (18). narayana (20) states that hybrid composite have a better adaptability than the packable composite this may be to that z250 particle size distribution is (0.01 to 3.5 µm) with an average particle size is (0.6 µm) and that the loading is (60% by volume) of inorganic filler. this lowering in leakage results could be due to the smaller particle size of hybrid.another explanation is that sdr is bulk fully filled in one layer of 4mm as manufacturer instruction, while vertise flow in this study filled in three layers (0.5, 1.5, 2mm) and both filtek z250 and riva light cure incrementally filled in (2, 2mm). this makes use of the main advantage of incremental technique, that is the volume reduction of each increment will be compensated by the next increment, thus the polymerization shrinkage of the last layer only, may damage the bond (18), but on the other hand few authors like (21) advocate the bulk increment as a safe restorative technique claiming that it fills the total volume of the preparation and creates less residual shrinkage stress than the incremental technique minimizing marginal leakage. these differences in layers between different types of materials used in this study had its effect on polymerization shrinkage from the depth of cure point of view since it is important to achieve sufficient irradiance at the bottom surface of each incremental layers used in building up the restoration. the concept of the point of sufficiency in this respect is called “depth of cure” (doc) (22) the intensity of light (strictly, the irradiance), at a given depth and for a given irradiation period, is a critical factor in determining the extent of reaction of monomer into polymer, typically referred to as "degree of conversion. a certain degree of conversion (dc) in resin-based materials must be achieved for the material to develop adequate physical and mechanical properties (22). many factors influence the degree and adequacy of the polymerization process, such as the type and relative amount of monomers, filler and initiator/catalyst as well as the shade and translucency of the material, its temperature during polymerization, the wavelength and intensity of the incident light, and the irradiation time )23). absorption and scatter within the material are the major factors causing light attenuation, rather than reflection from the restoration surface, as this is dependent on the formulation of the material, particularly the filler size, type and content (24). the actual time of 20 second as recommended by manufacturer to cure (4 mm) thickness of sdr, is thought to be insufficient for optimum polymerization, mainly on the bottom surface. the increasing of the distance from bottom up to the cusp tip makes a serious problem in curing causes the resin composite on the bottom surface and disperses the light of the light curing unit. as a result, when the light passes through the bulk of the composite, the light intensity is reduced and the energy of the light emitted from a light-curing unit decreased drastically when transmitted through resin composite, leading to a gradual decrease in degree of conversion of the resin composite material at increasing distance from the irradiated surface (24). these finding come with agreement with aguiar (25) and with clinical report of christensen (26) who compared different types of bulk fill resins he concluded that the most bulk fill resins have many challenges which still exist for most material that include the light cure does not reach the bottom of deep box form. camargo (27) states that increments must be kept to a maximum thickness of (2.0 mm) to achieve a good curing depth. while lotfi (12) compared gingival microleakage in class ii restorations by using different flowable composites as liner found that the lowest amount of microleakage was in surefil sdr flow group. another explanation is that composite composition affects the depth of cure, which is dependent on the formulation of the material, particularly the filler size, type and content this may explained by that smaller filler particles scatter the light more than large filler particles because those particle sizes are similar to the wavelengths emitted from composite curing j bagh college dentistry vol. 28(4), december 2016 gingival marginal the restorative dentistry 47 lights. light attempting to penetrate small particle composites, therefore, has a more difficult task to penetrate the deeper regions of the material and greater irradiances or exposure times are required to cure the composite adequately. another important factor, is the proportion of the filler relative to resin matrix: the higher the proportion of fillers, the more difficult to penetrate the composite by curing light source, the total summation of curing time that is received for each group will be as follows (80, 60, 60, 40) for vertise flow, riva light cure, filtek z250, and sdr respectively. so, the vertise flow group had received the highest total time for curing, this may explain the results of our study, as increasing time of curing will increase cross-linking of polymerization and thus enhance its properties.this comes in agreement with thiab (22) who compared the effect of curing time on depth of cure, he found that groups that were cured for 60 seconds gave significantly higher doc values than groups that were cured for 40 seconds, while 20 seconds curing time gave the least doc values. the possible explanation is that absorption of light with an appropriate wavelength initiates a free radical polymerization process of the methacrylate groups in visible light cured composite resins resulting in the formation of a cross-linked polymeric matrix(28) and more time of curing will enhance this cross-linking process. another explanation for the good results of the vertise flow is that the bonding mechanism of vertise flow is primarily based on the chemical bond between the phosphate functional group of gpd monomer and calcium ions of the tooth. a micromechanical bond resulting from an interpenetrating network between vertise flow polymerized monomers and dentin collagen fibers, also contributes to adhesion (vertise flow product manual, 2009). in vivo study conducted by vitchii (21) to study the properties of vertise flow with recall intervals, he noticed that at the 6-month recall, no post-operative sensitivity was reported of the forty performed restorations. therefore, he confirmed the claimed ability of vertise flow to achieve effective sealing between the tooth and restoration. the results of this 6-month study demonstrated a successful clinical outcome of the 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120-7. http://www.iasj.net/iasj?func=search&query=au:%22sa%27di%20shirshab%20thiab,%20qasim%20%20abdui-kareem%20mohammad,%20ahmed%20ghanim%20mahdi%20%22&uilanguage=en http://www.iasj.net/iasj?func=issues&jid=117&uilanguage=en nada f.doc j bagh college dentistry vol. 27(3), september 2015 enamel defect of pedodontics, orthodontics and preventive dentistry152 enamel defect of primary and permanent teeth in relation to nutrients daily intake among down's syndrome children in comparison to normal children nada j. mh. radhi, b.d.s., m.sc., ph.d. (1) sulafa k. el-samarrai, b.d.s., m.sc., ph.d. (2) jassem t. alkhafaji, b.d.s., m.sc., ph.d. (3) abstract background: any child with down's syndrome does not develop in the same manner as normal child. therefore, the child should not be viewed as being like everyone else. developmental enamel defects in primary teeth have been found at least twice as frequently in disabled children as in control children. down's syndrome consumed protein more than the recommended daily allowance compared to other disabled groups. therefore, the aim of this study was to investigate developmental defects of enamel and their relations to nutrient intake among down's syndrome children in comparison to normal children. materials and methods: a sample consisted of fifty institutionalized down's syndrome children (study group) and 50 normal children (control group) aged 7-10 years old. enamel anomalies were assessed according to criteria of who (1997). the dietary history was assessed through the use of food frequency questionnaire. nutrients analysis was achieved by using a special software program designed by diab (2003). all data were analyzed using spss version 13. results: a higher percentage of children with enamel anomalies were recorded among study compared to control group. demarcated opacities were the most distributed type in permanent teeth of the study group while diffuse opacities were the most distributed type among the control group. most of nutrients showed weak negative non significant correlations with enamel defects (demarcated opacities, hypoplasia) of primary teeth in study and control groups (p> 0.05). results revealed lower mean values of most of daily nutrients intake among the study group than the control group. conclusion: this study reports a higher percentage of down's syndrome children with enamel anomalies compared to normal children which may explain a negative correlation with most of daily nutrients intake, this may indicates that those population in need of preventive dietary program. key words: down's syndrome, enamel defects, protein, vitamin c, vitamin a, phosphorus, calcium. (j bagh coll dentistry 2015; 27(3):152-158). introduction down's syndrome was the first chromosomal abnormality discovered in humans and results from the presence of an extra copy of chromosome 21 (1). the incidence of trisomy 21 correlates strongly with increasing age, that is, young mothers have a low probability of having trisomy 21 children, but the risk increases rapidly after the age of 35 years (2). concerning the enamel defect among down's syndrome, almost 50% of persons with down's syndrome exhibit three or more dental anomalies. enamel hypocalcification occurs in about 20% of persons (3). iraqi studies regarding normals reported that the mean number of primary and permanent teeth with demarcated opacities was higher among well-nourished children than among underweighted and stunted children (4,-6). it was reported that the deficiencies of nutrients intake during teeth development increased the developmental defects of these dentition (4,7). (1) assist. prof., department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (3) consultant, department of immunology, medical teaching laboratories, medical city. no previous iraqi study has been conducted regarding the enamel defects and nutrients intake of down's syndrome children. the aim of this study was to measure enamel defects of both primary and permanent teeth and their relations to daily nutrients intake among down's syndrome children in comparison to normal children. materials and methods the sample consists of 50 down's syndrome children (study group) in mentally retarded institutions in baghdad city with age range (7-10) years and a matching comparative sample of the control group was chosen randomly from primary schools (8) in the same geographical area of institutions. enamel defects were recorded following the criteria of who; ten index teeth were examined on the buccal surface only, if any index tooth is missing, the area was excluded. these teeth are for permanent: upper left and right central and lateral incisors, canine, first premolar and the lower left and right first molar while for primary teeth: upper left and right central and lateral incisors, canine, first molar, and lower left and right second molar (9). clinical examination was conducted using plane mouth mirror and dental probe. a food j bagh college dentistry vol. 27(3), september 2015 enamel defect of pedodontics, orthodontics and preventive dentistry153 frequency questionnaire was used to assess the dietary history of the sample (10). it consists of food items commonly consumed in iraq, this was achieved from the nutrition research institution in baghdad province, for each food items, child's parent was asked to indicate the average frequency of consumption over the past year by selection one of frequency categories ranging from never to four items per day. the selected frequency categories for each food items were converted to daily intake. in addition, other food components were added which are prepared by other countries and now consumed in iraq. nutrient analysis was measured by a special software program (4). statistical package for social sciences (spss) version 13 was used for statistical analysis. the normally distributed variables were described by mean and sd and the parametric statistical tests were used (t-test), while non-normally distributed variables were statistically analysis by the nonparametric tests (mann-whitney test). multiple regression models were used to assess the net and independent effect of each of a set of explanatory variables on a response (dependent) quantitative variable. p value less than the 0.05 level of significance was considered statistically significant. results table (1) illustrates the distribution of children with enamel anomalies among study and control groups according to age groups and gender. a higher percentage of children with anomalies were recorded among study compared to control group. table (2) demonstrates the mean number of primary and permanent teeth with enamel anomalies among study and control groups. the mean numbers of primary teeth with enamel anomalies were higher among the study group compared to the control group with no significant difference (p> 0.05). at both age groups no statistical significant differences were noticed in mean number of primary teeth with enamel anomalies for both genders among study and control groups. concerning the permanent teeth with enamel anomalies a higher mean value was recorded among the study group compared to the control group, difference was statistically significant (mann-whitney= 1083, z= -1.971, p< 0.05). total males and females demonstrated a higher mean number of teeth with anomalies among the study group than the control group, this was statistically not significant (p> 0.05). at 9-10 years of age a higher mean number of permanent teeth with enamel anomalies was noticed among the study group compared to the control group, difference was statistically significant (mann-whitney= 347.5, z= -2.44, p< 0.05). table (3) shows the distribution of children concerning enamel anomalies types in primary and permanent teeth among study and control groups. demarcated opacities were the most distributed type in permanent teeth of the study group while diffuse opacities were the most distributed type among the control group. hypoplasia was recorded in primary teeth of the study group compared to the control group. the percentage of children with demarcated and diffuse opacities in their permanent teeth was higher among the study group compared to the control group. tables (4) and (5) demonstrate the mean percentage of primary and permanent teeth with different types of enamel anomalies. results showed a lower mean percentage of primary teeth with demarcated opacities among the study group compared to the control group. a higher mean percentage of permanent teeth were recorded with demarcated and diffuse opacities among the study group compared to the control group. table 1: distribution of children with enamel anomalies among study and control groups by age groups and gender age group (years) gender study group control group total no. no. % total no. no. % 7-8 m 14 2 14.3 14 3 21.4 f 6 0 0 6 0 0 t 20 2 10 20 3 15 9-10 m 22 7 31.8 22 1 4.5 f 8 1 12.5 8 0 0 t 30 8 26.7 30 1 3.3 all m 36 9 25 36 4 11.1 f 14 1 7.1 14 0 0 t 50 10 20 50 4 8 j bagh college dentistry vol. 27(3), september 2015 enamel defect of pedodontics, orthodontics and preventive dentistry154 table 2: mean number of primary and permanent teeth with enamel anomalies among study and control groups by age groups and gender. age group (years) gender study group control group primary teeth permanent teeth primary teeth permanent teeth mean ± sd mean ± sd mean ± sd mean ± sd 7-8 m 0.29 ± 1.07 0.14 ± 0.36 0.14 ± 0.53 0.43 ± 1.16 f 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 t 0.2 ± 0.89 0.1 ± 0.31 0.1 ± 0.45 0.3 ± 0.98 9-10 m 0.00 ± 0.00 0.95 ± 2.57 0.00 ± 0.00 0.36 ± 1.71 f 0.00 ± 0.00 1.00 ± 2.83 0.00 ± 0.00 0.00 ± 0.00 t 0.00 ± 0.00 0.97 ± 2.59 0.00 ± 0.00 0.27 ±1.46 all m 0.11 ± 0.67 0.64± 2.04 0.06 ± 0.33 0.39 ± 1.5 f 0.00 ± 0.00 0.57 ± 2.14 0.00 ± 0.00 0.00 ± 0.00 t 0.08 ± 0.57 0.62 ± 2.05 0.04 ± 0.28 0.28 ± 1.28 table 3: distribution of children concerning enamel anomalies types among study and control groups. types of defect study group control group (total no.= 50) (total no.= 50) primary teeth permanent teeth primary teeth permanent teeth no. % no. % no. % no. % demarcated opacities 1 2 7 14 1 2 1 2 diffuse opacities 0 0 3 6 0 0 2 4 hypoplasia 1 2 0 0 0 0 0 0 table 4: mean percentage of primary teeth with enamel anomalies among study and control groups by age groups and gender. age group (years) gender study group control group demarcated opacities diffuseopacities hypoplasia demarcated opacities diffuseopacities hypoplasia mean ± sd mean ± sd mean ± sd mean ± sd mean ± sd mean ± sd 7-8 m 0.7 ± 2.67 0.00 ± 0.00 0.7 ± 2.67 1.4 ± 3.35 0.00 ± 0.00 0.00 ± 0.00 f 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 t 0.5 ± 2.24 0.00 ± 0.00 0.5 ± 2.24 1.0 ± 4.47 0.00 ± 0.00 0.00 ± 0.00 9-10 m 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 f 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 t 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 all m 0.3 ± 1.67 0.00 ± 0.00 0.3 ± 1.67 0.6 ± 3.33 0.00 ± 0.00 0.00 ± 0.00 f 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 t 0.2 ± 1.41 0.00 ± 0.00 0.2 ± 1.41 0.4 ± 2.83 0.00 ± 0.00 0.00 ± 0.00 table 5: mean percentage of permanent teeth with enamel anomalies among study and control groups by age groups and gender. age group (years) gender study group control group demarcated opacities diffuseopacities hypoplasia demarcated opacities diffuseopacities hypoplasia mean ± sd mean ± sd mean ± sd mean ± sd mean ± sd mean ± sd 7-8 m 1.4 ± 3.63 0.00 ± 0.00 0.00 ± 0.00 1.4 ± 5.35 1.4 ± 5.35 0.00 ± 0.00 f 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 t 1.0 ± 3.08 0.00 ± 0.00 0.00 ± 0.00 1.0 ± 4.47 1.0 ± 4.47 0.00 ± 0.00 9-10 m 3.2 ± 6.46 3.2 ± 12.87 0.00 ± 0.00 0.00 ± 0.00 1.8 ± 8.53 0.00 ± 0.00 f 0.00 ± 0.00 5.00 ± 14.14 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 t 2.3 ± 5.68 3.9 ± 12.99 0.00 ± 0.00 0.00 ± 0.00 1.3 ± 7.3 0.00 ± 0.00 all m 2.5 ± 5.54 1.9 ± 10.09 0.00 ± 0.00 0.6 ± 3.33 1.7 ± 7.37 0.00 ± 0.00 f 0.00 ± 0.00 2.9 ± 10.69 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 0.00 ± 0.00 t 1.8 ± 4.82 2.2 ± 10.16 0.00 ± 0.00 0.4 ± 0.83 1.2 ± 6.27 0.00 ± 0.00 j bagh college dentistry vol. 27(3), september 2015 enamel defect of pedodontics, orthodontics and preventive dentistry155 the present study revealed a higher amount of calcium (mg) was consumed by the study group (789.94± 135.39) compared to the control group (778.30 ± 77.29) with no statistically significant difference (p> 0.05). concerning vitamin c (mg), higher amount was consumed among study (108.02 ± 15.53) compared to control group (96.81 ± 11.79) with highly significant difference (t= 4.518, df= 98, p< 0.01). while lower amounts of protein (gm), phosphorus (mg), iron (mg) and vitamin a (i.u) were consumed by the study group (60.60 ± 3.85; 964.34 ± 210.68; 9.89 ± 1.97; 3863.74 ± 548.26 respectively) compared to the control group (60.75 ± 2.60; 964.94 ± 159.70; 12.23 ± 2.42; 4402.43 ± 635.25 respectively). highly significant differences were recorded regarding iron (t= 5.305, df= 98, p< 0.001) and vitamin a (t= 4.497, df= 98, p< 0.001). table (6) demonstrates the correlation coefficient between mean percentage of primary and permanent teeth with enamel defect and nutrient daily intake in study and control groups. most of nutrients showed weak negative nonsignificant correlations with enamel defects (demarcated opacities, hypoplasia) of primary teeth in study and control groups. positive correlations were found for vitamin c in the study group and vitamin a in the control group. concerning defects (demarcated opacities, diffuse opacities) in permanent teeth the direction of correlation was found positive for all nutrients except ca/p ratio in the study group. significant correlation was achieved concerning phosphorus only with demarcated opacities. in the control group the direction of correlation with enamel defect (demarcated opacities, diffuse opacities) was observed negative with most nutrients except a positive correlation between vitamin c and demarcated opacities. table 6: correlation coefficient between nutrient daily intake and enamel defect of primary and permanent teeth among study and control groups groups teeth protein (gm) calcium (mg) phosphorus (mg) ca/p ratio iron (mg) vitamin a (i.u) vitamin c (mg) r p r p r p r p r p r p r p study p rim ary 1 0.124 0.392 0.144 0.32 0.025 0.865 0.163 0.257 0.213 0.138 0.124 0.392 0.025 0.864 2 ---------------------------------------------------------------------- 3 0.124 0.392 0.144 0.32 0.025 0.865 0.163 0.257 0.213 0.138 0.124 0.392 0.025 0.864 p erm anen t 1 0.222 0.122 0.139 0.335 0.312 0.027* -0.225 0.116 0.074 0.609 0.245 0.087 0.12 0.405 2 0.231 0.106 0.182 0.205 0.122 0.399 -0.062 0.668 0.001 0.997 0.198 0.167 0.072 0.617 3 ---------------------------------------------------------------------- c ontrol p rim ar y 1 0.134 0.355 0.223 0.119 0.054 0.707 0.144 0.32 0.153 0.287 0.069 0.632 0.144 0.32 2 ---------------------------------------------------------------------- 3 ---------------------------------------------------------------------- p erm anen t 1 0.104 0.473 0.096 0.508 0.104 0.473 0.074 0.608 0.134 0.355 0.129 0.373 0.094 0.516 2 -0.096 0.508 0.223 0.12 0.089 0.537 0.091 0.529 0.197 0.17 0.096 0.505 0.071 0.625 3 ---------------------------------------------------------------------- 1= demarcated opacities, 2= diffuse opacities, 3= hypoplasia * significant table (7) demonstrates the multiple linear regression of enamel defect of primary teeth explained by nutrient intake. only negative association with iron was noticed while positive non-significant associations were recorded with other nutrients. the model was statistically not significant and explains 6% of variation. the multiple linear regression of enamel defect of permanent teeth explained by nutrient intake is showed in table (8). iron and vitamin c were negatively associated with enamel defect of permanent teeth, highly significant correlation was recorded with iron. other nutrients were positively associated, only significant correlation was observed with protein. the model was statistically not significant and was able to explain 12% of variation. j bagh college dentistry vol. 27(3), september 2015 enamel defect of pedodontics, orthodontics and preventive dentistry156 table 7: multiple linear regression of enamel defect of primary teeth explained by nutrient daily intake partial regression coefficient s.e standardized coefficient t p-value ***study group -0.066 0.151 0.074 0.434 0.67 protein 0.023 0.029 0.17 0.795 0.43 calcium 0.000 0.001 -0.066 -0.343 0.73 ca/p ratio 3.012 0.315 0.137 1.051 0.3 iron -0.052 0.037 -0.291 -1.39 0.17 vitamin a 0.00000338 0.000 0.006 0.041 0.97 vitamin c 0.000 0.005 -0.013 -0.086 0.93 p (model) = 0.6 (not significant) r2= 0.06 ***being study compared to control group table 8: multiple linear regression of enamel defect of permanent teeth explained by nutrient daily intake partial regression coefficient s.e standardized coefficient t p-value ***study group -0.57 0.561 0.168 1.017 0.31 protein 0.227 0.108 0.434 2.094 0.039* calcium 0.003 0.003 0.18 0.963 0.34 ca/p ratio 0.789 1.171 0.136 1.082 0.28 iron -0.418 0.139 -0.609 -3.003 0.003** vitamin a 0.000 0.000 -0.051 -0.384 0.70 vitamin c -0.011 0.017 -0.09 -0.626 0.53 p (model) = 0.11 (not significant) r2= 0.12 *significant, **highly significant ***being study compared to control group discussion the present study showed that enamel anomalies in both primary and permanent dentitions were higher in down's syndrome compared to the control group. this observation was also recorded by previous studies (11-13), this may be attributed to genetic disorders. no previous iraqi study has been conducted among down's syndrome children to allow comparison the result of current study with. in the present study, results revealed a lower mean value of most daily nutrients intake among down’s syndrome compared to control group, this may explain the inverse relations between nutrients and the enamel defects of primary teeth. malnutrition in early childhood is associated with enamel hypoplasia of the primary dentition both of the classic, structural hypoplasia and with more limited evidence, for enamel opacities; there is weaker support for an enamel hypoplasia association with the permanent dentition due to a limited number of studies, potential malnutrition misclassification and confounding. the few studies of enamel hypoplasia properties not associated with known nutritional deficiencies in humans, suggest a decreased mineralization surface and subsurface of enamel affected by protein energy malnutrition (14). there has been a considerable interest in role of calcium and protein in tooth formation. the effect of long term deficiency upon cellular activity of the ameloblast seen by the effect of plasma level on structural abnormalities and consider as a risk factor (15,16). daily nutrients intake of current study were found to be higher regarding calcium and vitamin c among study group compared to controls. it was reported that vitamin and mineral intakes were lower overall in individual with down's syndrome than in normal, except for vitamin c (17). other studies also reported that children with down's syndrome tended to consume more calcium and vitamin c than the recommended dietary allowance (17,18). results showed a less iron consumption by study compared to control group. this was also found in other studies (17,18). this finding may be related to feeding difficulties and inappropriate nutrient and energy intakes which are common in children with down's syndrome (17), some children rejected to eat from specific food groups, such as milk, meat and/or fruits and vegetables, or these foods may be offered only in limited amounts as explained by parents in current study. the current study revealed a lower amount of vitamin a consumption among study compared to control group. it was reported that vitamin a supplements have been proposed for children with down's syndrome with claims of improving cognitive abilities, or immune function (19). vitamin a deficiency can slow down and even completely stop the grow of the incisor teeth of rat, accompanying this growth retardation was disturbance in differentiation and function of ameloblast, therefore enamel formation is interfered, this interference produces hypoplastic and chalky white incisor (20). however, this study recorded a negative correlation of vitamin a with j bagh college dentistry vol. 27(3), september 2015 enamel defect of pedodontics, orthodontics and preventive dentistry157 enamel defects of primary teeth among study group. there is a limitation regarding the possible etiological factors of enamel defects among down’s syndrome populations. therefore, this study was conducted to explore the possible etiological factors of this defect related to nutrients intake. . references 1. behrman re, kliegman rm. nelson essentials of pediatrics. 4th ed. st. louis: w.b. saunders; 2002. 2. cummings mr. human heredity, principles and issues. 6th ed. canada: thomson; 2003. p.155-7. 3. regezi j, sciubba j, jordan r. oral pathology. 4th ed. st. louis: saunders; 2003. p.358-60. 4. diab bs. nutritional status in relation to oral health condition among 6-10 years primary school iraqi children in the middle region of iraq. ph.d. thesis, college of dentistry, university of baghdad, 2003. 5. gatta ea. primary teeth emergence and enamel anomalies in relation to nutritional status among 4-48 months old children in baghdad city. a master thesis, college of dentistry, university of baghdad, 2005. 6. droosh mk. protein-energy malnutrition in relation to oral health condition among 6 and 9 year old primary school children in sulaimania city in iraq. a master thesis, college of dentistry, university of baghdad, 2007. 7. koch mj, spranger s and bettendorf m. distinctive pitted enamel hypoplasia and short stature. j craniofac-genet develo biol 2000; 20:155-6. 8. yammane t. statistic and introductory analysis. 3rd ed. tokyo: harper international edition; 1973. p. 677759. 9. who. oral health surveys basic methods 4th ed. world health organization. geneva, switzerland, 1997. 10. thompson fe, byers t. dietary assessment resource manual. j nutr 1994; 124: 2245-2317. 11. bhat m, nelson k. developmental enamel defects in primary teeth in children with cerebral palsy, mental retardation, or hearing deficits: a review. adv dent res 1989; 3(2):132-42. 12. regezi j, sciubba j, jordan r. oral pathology. 4th ed. st. louis: saunders; 2003. p. 358-60. 13. scully c and cawson r. medical problems in dentistry. 5th ed. italy: elsevier churhill livingstone; 2005. p. 423-5. 14. psoter wj, reid bc, katz rv. malnutrition and dental caries: a review of literature. caries res 2005; 39(6):441-7. 15. rugg-gunn a, nunn j. nutrition diet and oral health. 1st ed. oxford: oxford university press, 1999. 16. koch mj, spranger s and bettendorf m. distinctive pitted enamel hypoplasia and short stature. j craniofac-genet develo biol 2000; 20:155-6. 17. luke a, sutton m, schoeller da, roizen nj. nutrient intake and obesity in prepubescent children with down syndrome. j am diet assoc 1996; 96(12):12627. 18. chad k, jobling a, frail h. metabolic rate: a factor of developing obesity in children with down syndrome? am j ment retard 1990; 95(2): 228-35. 19. blair k, roesler m, xie y, gamis a, olshan a, heerema n, robison l and ross j. vitamin supplement use among children with down syndrome and risk of leukemia: a children’s oncology group (cog) study. paediatr perinat epidemiol 2008; 22(3): 288-95. 20. johansson i, ericson t, lumikari m. the effect of vitamin a deficiency on the secretion of saliva and two salivary glycoprotein's in adult rat. j vit nutr 1989; 59: 234-5. الخالصة وجد ان عیوب المیناء لدیھم اعلى مرتین من االطفال الطبیعیین ویستھلك اطفال متالزمة داون . یوجد اختالف في نمو طفل متالزمة داون قیاسا الى الطفل الطبیعي اطفال متالزمة لعناصر الغذائیة المتناولة لدىوعالقتھ با لذلك كان الھدف من ھذه الدراسة ھو لبحث عیوب المیناء. البروتین بنسبة اعلى من االعاقات االخرى .داون مقارنة الى االطفال الطبیعیین تم .سنوات 10-7بعمر ) مجموعة الدراسھ(وخمسین طفل طبیعي ) مجموعة الدراسة(من خمسین طفل متالزمة داون في المعاھد نھالعی تكونت :والطرق المواد تم التحلیل الغذائي من خالل احتساب العناصر الغذائیة بواسطة برنامج حاسوب صمم من قبل (who, 1997 ). لتصنیف تبعا قیاس عیوب المیناء spss 13. باستخدام احصائیا البیانات جمیع حللت .) (diab, 2003دراسة العتمة البیضاء ھي النوع االكثر .ضابطةاالطفال المصابین بعیوب المیناء لدى مجموعة الدراسة مقارنة الى المجموعة ال من العالیة النسبة سجلت :النتائج اشارت الدراسة الى عالقة عكسیة ضعیفة وغیر .انتشارا في االسنان الدائمیة لدى اطفال متالزمة داون بینما لوحظ انتشار العتمة لدى المجموعة الضابطة كشفت النتائج .المجموعة الضابطة ومجموعة الدراسة اللبنیة لدى في االسنان )العتمة، نقص التنسج( واضحة معنویا بین العناصر الغذائیة وعیوب المیناء .المجموعة الضابطة مقارنة الىانخفاض في قیم العناصر الغذائیة المأخوذة یومیا لدى اطفال متالزمة داون والذي یمكن ان یفسر العالقة العكسیة مع معظم العناصر اقرت الدراسة ارتفاع في نسب االطفال المصابین بعیوب المیناء مقارنة الى االطفال الطبیعیین :الخالصة .یومیا، وھذا یشیر الى ان اطفال متالزمة داون بحاجة الى برنامج غذائي وقائي الغذائیة المتناولة zaynab f.doc j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry179 occlusal features, perception of occlusion and orthodontic treatment need and demand among 13 years aged baghdadi students part ii: (cross sectional epidemiological study) zaynab mohamed ridha al-chalabi, b.d.s. (1) fakhri abid ali al-fatlawi, b.d.s., m.sc. (2) abstarct background: the present study aimed to assess the distribution, prevalence, severity of malocclusion in baghdad governorate in relation to gender and residency materials and methods: a multi-stage stratified sampling technique was used in this investigation to make the sample a representative of target population. the sample consisted of 2700 (1349 males and 1351 females) intermediate school students aged 13 years representing 3% of the total target population. a questionnaire was used to determine the perception of occlusion and orthodontic treatment demand of the students and the assessment procedures for occlusal features by direct intraoral measurement using veriner and an instrument to measure the rotated and displaced teeth. results and conclusions: the presence of malaligned teeth was reported by 39% of the sample. the most prevalent reported types of malaligned teeth were spaced teeth (26.6%); of the students who stated that they have malaligned teeth, 70.3% thought that it affected their appearance, 17.8% affected chewing, and 7.8% affected speech; the most common reasons for not seeking orthodontic treatment were the thought that treatment is not important or not possible (25.8%) and fear of pain (48.8%).one or more missing teeth due to extraction or trauma were found in 4.9% of the sample,the most common extracted tooth was the mandibular first molar. crowding was more concentrated in the lower anterior segment while the spacing cases were higher and more concentrated in the upper anterior segment. a maxillary central diastema was found in 18.1 % of the sample with a mean of 0.306 mm. anterior irregularities were found in (18.36 %maxillary and 26.84% mandibular),mean overjet 3.310 mm, mean overbite was 2.99 mm, class i angle class was found in 78.29%, class ii in 19.5% and class iii in 2.3%. posterior crossbite found in 5.6%, anterior openbite (1.7%) and midline shift (54.34 %).normal lip form was found in 86.6%, soft tissue impingement in 3.3%.the treatment need according to dai show that 72.3% of the sample were found to have no or slight treatment need, 15.9% with treatment elective, 7.3% with treatment highly desirable, and 4.5% with treatment mandatory.also increase the need and decrease demand for orthodontic treatment among adolescents in the baghdad commune. this data will be useful for public oral health service and emphasize the need for orthodontic treatment among baghdadi adolescents. key words: occlusal features, perception of occlusion, treatment need. (j bagh coll dentistry 2015; 27(3):179-186). introduction malocclusion is any deviation in the arrangement of the teeth exceeding the standards of normal occlusion. it may be associated with anomalies within the dental arches (i.e. crowding and spacing), malrelation of dental arches (i.e. anteroposterior, vertical and transverse anomalies) and skeletal discrepancies (1). many studies have reported on the prevalence of malocclusion in different populations (2-4). the prevalence of malocclusion varies between different populations, ethnicities and age groups. variations within the same population have also been noticed, especially in respect of both crowding and the sagittal dental arch relationship (5,6). moreover, the criteria for the recorded items (registration methods) seem to play an important role for the variation in the prevalence. (1)master student. department of orthodontics. college of dentistry, university of baghdad. (2)professor. department of orthodontics. college of dentistry, university of baghdad. a thorough investigation of the occurrence of malocclusions among school–students would be of major importance in the planning of orthodontic treatment in the public dental health services. and moreover, an analysis of the need for orthodontic treatment in the different school classes (7). analysis of the prevalence rates of malocclusion in such groups may also contribute to understanding of the causes of malocclusion (8). this study was carried out in baghdad city since there no study has been done since 2002 on permanent dentition and it is designed to provide a base line data on the malocclusion of male and female sample during permanent dentition. materials and methods the present epidemiological survey was conducted during the period between february to may 2014 in baghdad cityand five small surrounding villages selected accordingto their geographical location and number of population. j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry180 the sample the sample consisted of 13-year-old students attending first year intermediate schools.baghdad were split into two sectors karkh and rusafa on either side of the tigris river. each sector was handled as a separate entity in respect to the distribution of examination clusters. however, in the data analysis baghdad was handled as one governorate. permission was obtained from the directorate of education. the schools authorities were contacted and the purpose of the study was explained to them to assure full cooperation.a multi-stage stratified sampling technique implemented in this investigation and the planning was to be 2540 students included in thesurvey, half of whom (1270 students) urban and the otherhalf rural.urban students were considered as students living inthe center of baghdad city taken as clusters of 63 students from 10 randomly selected schools. rural students were selected randomly from five small villages, two clusters of 63 students from each village. examination area each student was seated on an ordinary chair taken from the host school with his or her head supported in an upright position against the wall directly facing the examiner (9). when possible the examination area waspartitioned or arranged in such a way that student entered at one point and left atanother. students were not permitted tocrowd around the examiner. natural daylight was utilized as the light source for the examination, and a portable light was used to supplement natural daylight during examination when needed and in the absence of electricity, the portable light was connected to a 1.5v battery. questionnaire before any dental examination wasdone, the date of examination, governorate,location, schools name, school classand gender of the students was registered.then the students were eachinterviewed individually to obtain firstdemographic information regarding theirname and birth date.the student was asked some questionsregarding his/ her perception of occlusion.this questionnaire was modified from ingervall et al, ng’ang’a et al. (10, 11). clinical examination before the intraoral clinical examinationwas commenced, gross anomalies, cleft lipand/or palate, traumatic or surgical defectswere noted and described in the notessection. the intraoral examination was derivedfrom the epidemiological index of bjork et al.(7) and thefdi index (9), in additionto the dental aesthetic index (12).the following variables were examined: missing permanent teeth due toextraction or trauma, rotated tooth (>15 degrees),displaced tooth (>1mm), angle`s classes of occlusion(class i molar occlusion, class ii molarocclusion and classiii molar occlusion), overjet (mm), overbite(mm), anterior openbite (mm), posterior crossbite, scissors bite, midline displacement (>0.5mm), maxillary median diastema(≥0.5mm), anterior irregularities (≥1mm), spacing and crowding (one anteriorsegment and two lateral segments of the botharches), soft tissue impingement, lip formperception of occlusion and treatment need was recorded according to the components of dental aesthetic index (dai). the dai scores were dichotomized as “no need for treatment” (dai < 25) and “in need of treatment” (dai > 25). inter-and intra-examiner calibration was performed before the study, to ensure the consistent application of the diagnostic criteria. the results showed no statistically significant difference. results and discussion the total number of examined students was 2738; from which 200casesheets were excluded because ofincomplete or inaccurate information or incorrect age orcurrently undergoing orthodontic treatment and those who have undergone extraction of permanent teeth to improve appearance, giving avalid sample of 2538; 635 males (317urbans and 318rurals) and 635 females (318urbans and 317rurals)(table 1,2). table 1: number and distribution of all the examined students. location gender baghdad total karkh rusafa urban males 347 347 694 females 347 348 695 total 694 695 1389 rural males 337 337 674 females 337 338 675 total 674 675 1349 total males 684 684 1368 females 684 686 1370 total 1368 1370 2738 j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry181 table 2: number and distribution of case sheets included in the statistical analysis missing teeth due to extraction or trauma were found in 4.9% of the sample, most commonly first molars. the results of the present study are in accordance with the studies by rasheed (13).rotated teeth (>15˚) were found in 38.3% which slightly lower than that found by hoffding and kisling (14); and displaced teeth (>1mm) in 19.6% of the sample which less than found by rasheed (13). the most prevalent molar relationship in the malocclusion was angle’s class i occlusion in 78.29%of the sample, class ii in 19.5% (17.2% division 1 and 2.3% division 2) and 2.3% had class iii malocclusion (1.6% postural and 0.7% true). the distribution of the classes of occlusion according to gender was statistically significant for total sample which was in agreement with rasheed (15) while the distribution of the classes of occlusion among urban and rural males was much alikewhile rural males showed more class ii occlusion (25.7%) than urban males (19.9%). however, this was statistically insignificant for total sample that in agreement with that of alhuwaizi (16). (fig. 1) the mean oj was (3.31± 0.04) ranging from –5.0 to 14.0 mm. urban males had a statistically insignificantly higher mean overjet than urban females. this is in accordance with the findings of al-huwaizi (16) (fig. 2). the mean overbite of the sample was (2.99 ± 0.03). males had a higher mean overbite (3.11± 0.05) than females (2.88± 0.04).this was statistically significant for total sample as shown in (fig. 3).urban males and females had a higher mean overbite (3.06± 0.04) than rural males and females (2.93± 0.04). however, these differences were statistically insignificant for total sample as shown in (table 3.49) this is in accordance with the findings of al-huwaizi (16) (fig. 3). figure 1: distribution of the angle’s classification by residency and gender. prevalence of open bite was found to be 1.7%. a total of 5.6% had posterior crossbite ranging from unilateral involving one or several teeth to bilateral and complete which are in correlation with al-huwaizi (16)(table 3). scissors bite was found to be 2.3%. median diastema was present in 18.1%. the prevalence was similar in boys and girls (table 4). figure 2: overjet values of the total sample according to residency and gender. total baghdad gender residency rusafa karkh 635 318 317 male urban 636 318 318 female 1271 636 635 total 633 315 318 male rural 634 317 317 female 1267 632 635 total 1268 633 635 male total 1270 635 635 female 2538 1268 1270 total j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry182 table 3: distribution of the posterior crossbite according to type by residency and gender n.s: no significant difference at p > 0.05. figure 3: overbite values of the total sample according to residency and gender. table 4: distribution of the width (in mm) of the maxillary central diastema by residency and gender. n.s: no significant difference at p > 0.05. urban rural total m n=635 f n=636 t n=1271 m n=633 f n=634 t n=1267 m n=1268 f n=1270 t n=2538 n % n % n % n % n % n % n % n % n % unilateral right 16 2.5 14 2.2 30 2.4 10 1.6 17 2.7 27 2.1 26 2.1 31 2.4 57 2.2 unilateral 9 1.4 15 2.4 24 1.9 11 1.7 16 2.5 27 2.1 20 1.6 31 2.4 51 2.0 bilateral 8 1.3 11 1.7 19 1.5 6 0.9 10 1.6 16 1.3 14 1.1 21 1.7 35 1.4 total 33 5.2 40 6.3 73 5.7 27 4.3 43 6.8 70 5.5 60 4.7 83 6.5 143 5.6 gender differences x 2 = 4.394, d.f. = 3, p-value = 0.222, ns residency differences x 2 = 0.586, d.f. = 3, p-value = 0.899, ns urban rural total m n= 635 f n=636 t n= 1271 m n= 633 f n=634 t n= 1267 m n= 1268 f n=1270 t n= 2538 n % n % n % n % n % n % n % n % n % 1 mm 68 10.7 71 11.2 139 10.9 55 8.7 55 8.7 110 8.7 123 9.7 126 9.9 249 9.8 2 mm 30 4.7 35 5.5 65 5.1 26 4.1 29 4.6 55 4.3 56 4.4 64 5.0 120 4.7 3 mm 15 2.4 26 4.1 41 3.2 19 3.0 18 2.8 37 2.9 34 2.7 44 3.5 78 3.1 4 mm 1 0.2 2 0.3 3 0.2 6 0.9 2 0.3 8 0.6 7 0.6 4 0.3 11 0.4 5 mm 1 0.2 0 0.0 1 0.1 0 0.0 1 0.2 1 0.1 1 0.1 1 0.1 2 0.1 total 115 18.1 134 21.1 249 19.6 106 16.7 105 16.6 211 16.7 221 17.4 239 18.8 460 18.1 mean 0.287 0.357 0.322 0.297 0.284 0.290 0.292 0.321 0.306 s.e. 0.028 0.031 0.021 0.030 0.029 0.021 0.021 0.021 0.015 gender differences t-test = -0.966, d.f. = 2536, p-value = 0.334, ns residency t-test = 1.056, d.f. = 2536, p-value = 0.291, ns j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry183 the maxillary anterior region showed the highest prevalence (15.2%) of spacing (≥2mm) and the mandibular anterior region showed the highest prevalence (12.6%) of crowding (≥2mm). the presence of crowding and spacing in the dental arches may be due to dentoalveolar and tooth size and jaw size discrepancies. the high prevalence of crowding may also partly be explained by the occurrence of caries and molar extraction, which causes the migration of the first permanent molar, inclinations and rotations. anterior irregularities (≥1mm) were found in (18.36 %maxillary and 26.84% mandibular), the results compared with the chauhan et al. (17) found that their result quite low as compared to the present study.midline shift (54.34 %) that close to abdulla (18). of the sample, 3.0% had palatal soft tissue impingement, and 0.3% had labial soft tissue impingement that revealed close percentage that recorded by al-huwaizi(16).considering gender and residency difference, soft tissue impingement was statistically insignificantly distributed between them (table 5). of the sample, (86.60%) had a normal lip form, (10.13%) had a contracting lip form and 83 students (3.27%) had lip trap. considering gender difference, lip form was statistically significantly distributed between both genders for total sample; lip form was also statistically significantly distributed between urbans and rurals for total sample as shown in table (table 6). table 5: distribution of the soft tissue impingement according to type by residency and gender urban rural total m n=635 f n=636 t n=1271 m n=633 f n=634 t n=1267 m n=1268 f n=1270 t n=2538 n % n % n % n % n % n % n % n % n % palatal 16 2.5 19 3.0 35 2.8 26 4.1 14 2.2 40 3.2 42 3.3 33 2.6 75 3.0 labial 1 0.2 2 0.3 3 0.2 3 0.5 1 0.2 4 0.3 4 0.3 3 0.2 7 0.3 gender differences x2 = 1.28, d.f. = 2, p-value = 0.527 (ns) residency differences x2 = 0.511, d.f. = 2, p-value = 0.775 (ns) n.s: no significant difference at p > 0.05. regarding perception of occlusion; the presence of malaligned teeth was reported by 39% of the sample. the most prevalent reported types of malaligned teeth were spaced teeth (26.6%); of the students who stated that they have malaligned teeth, 70.3% thought that it affected their appearance, 17.8% affected chewing, and 7.8% affected speech; the most common reasons for not seeking orthodontic treatment were the thought that treatment is not important or not possible (25.8%) and fear of pain (48.8%), similar to that of al-huwaizi (16) and al-zubair (20). the treatment need according to dai show that 72.3% of the sample were found to have no or slight treatment need, 15.9% with treatment elective, 7.3% with treatment highly desirable, and 4.5% with treatment mandatory.this study showed close levels of orthodontic treatment need to that of al-huwaizi(16), tak et al.(19). considering gender differences, males showed high mean dai score (23.67± 0.171) to that of females (22.803± 0.161). this was statistically significant for total sample as shown in (fig 4,5). the rurals showed a slightly higher mean dai score (24.050 ± 0.252 for males and 22.778 ± 0.227 for females) than for the urbans (23.246± 0.232 for males and 22.829 ± 0.227 for females). this was statistically insignificant for total sample (fig 4,5). dai scores where there is severe malocclusion and treatment is highly desirable or mandatory were found more in the rural sample (13.3%) than in the urban sample (10.3%) this was in agreement with al-huwaizi(16),hemapriya et al. (21)and contradicts the findings of ansai et al.(22) who found that in his sample urban students had significantly higher dai scores than rural students and this may be attributed to racial differences. this study suggests that there is need for intensified oral health education in rural areas, targeted at both parents and school children to enable them benefit from interceptive orthodontic care which has numerous benefits. j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry184 figure 4: distribution of the total sample according to their dai scores residency and gender. table 6: distribution of lip form according to type by residency and gender hs: highly significant p <0.01. s: significant p<0.05 figure 5: distribution of the mean of the total sample according to their dai scores residency and gender. perception of occlusion first of all, we will discuss the three questions regarding the past and present orthodontic treatment of the students. of the sample, 4.8% did or were doing orthodontic treatment, 1.2% had undergone extractions to improve appearance, and 1.7% reported that their treatment was postponed by a dentist for a later time; giving a total of 7.7% of the sample who have had some type of orthodontic treatment or consultation. • regarding the self-evaluation of the students to the alignment of their teeth, 39.1% of them answered that they have malaligned teeth. • concerning the type of malaligned teeth, the children reported their malocclusion type as follow with descending sequence of prevalence spaced, crowded, rotated and displaced teeth awareness of spacing was a highly significant relation between the positive answers to this choice and the presence of spacing. this sequence different from al-huwaizi(13). (table 7). • of the 991 students who stated that they have malaligned teeth; 70.3% thought that it affected their appearance, 17.76% affected chewing, and 7.77% affected speech, while 4.14% answered that malaligned teeth did not affect appearance or speech. this result is comparable to that found by al-huwaizi(13)andal-zubair(20)(table 8). • the most common reason for not seeking orthodontic treatment was that the students thought that treatment is not important, fear of pain, treatment is expensive, and treatment is not possible. the predominance of fear of pain is similar to that of al-huwaizi (13) and alzubair (20). (table 9). urban rural total m f t m f t m f t n % n % n % n % n % n % n % n % n % normal 526 82.8 562 88.4 1088 85.6 538 85.0 572 90.2 1110 87.6 1064 83.9 1134 89.3 2198 86.6 contract 87 13.7 60 9.4 147 11.6 53 8.4 57 9.0 110 8.7 140 11.0 117 9.2 257 10.1 trap 22 3.5 14 2.2 36 2.8 42 6.6 5 0.8 47 3.7 64 5.0 19 1.5 83 3.3 total 635 100 636 100 1271 100 633 100 634 100 1267 100 1268 100 1270 100 2538 100 gender differences x 2 = 28.684, d.f. = 2, p-value = 0.000, hs residency differences x 2 = 6.999, d.f. = 2, p-value = 0.030, s j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry185 table 7: distribution of the answers to question 2 regarding the type of malalignment of teeth by residency and gender s: significant p<0.05n.s: no significant difference at p > 0.05. table 8: distribution of the answers to question 3 regarding the effect of the malalignment of teeth by residency and gender urban rural total m n=221 f n=270 t n=491 m n=215 f n=285 t n=500 m n=436 f n=555 t n=991 n % n % n % n % n % n % n % n % n % appearance 133 60.2 222 82.2 354 72.2 134 62.3 208 73.1 343 68.5 267 61.2 430 77.5 697 70.3 chewing 60 27.1 29 10.8 89 18.2 48 22.3 39 13.6 87 17.4 108 24.8 68 12.3 176 17.8 speech 23 10.4 15 5.6 38 7.7 13 6.0 26 9.1 39 7.8 36 8.3 41 7.4 77 7.8 no effect 5 2.3 4 1.5 9 1.8 20 9.3 12 4.2 32 6.4 25 5.7 16 2.9 41 4.1 gender differences x2 = 35.736, d.f. = 3, p-value = 0.000, hs residencey differences x2 = 13.1, d.f. = 3, p-value = 0.004, hs hs: highly significant p <0.01. table 9: distribution of the answers to question 4 regarding the reason for not seeking treatment by residency and gender urban rural total m n=221 f n=270 t n=491 m n=215 f n=285 t n=500 m n=436 f n=555 t n=991 n % n % n % n % n % n % n % n % n % treatment is not important 67 30.3 55 20.4 122 24.8 77 35.8 57 20 134 26.8 144 33.0 112 20.2 256 25.8 treatment is not possible 29 13.1 21 7.8 50 10.2 15 7 24 8.4 39 7.8 44 10.1 45 8.1 89 9 fear of pain 93 42.1 151 55.9 244 49.7 87 40.5 153 53.7 240 48 180 41.3 304 54.8 484 48.8 fear of extraction 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 treatment is expensive 17 7.7 12 4.4 29 5.9 20 9.3 31 10.9 51 10.2 37 8.5 43 7.7 80 8.1 postponed by dentist 4 1.8 7 2.6 11 2.2 2 0.9 4 1.4 6 1.2 6 1.4 11 2 17 1.7 no time for treatment 10 4.5 5 1.9 15 3.0 7 3.3 8 2.8 15 3 17 3.9 13 2.3 30 3.0 fear of crosscontamination 2 0.9 4 1.5 6 1.2 0 0 0 0 0 0 2 0.5 4 0.7 6 0.6 hope for spontaneous improvement 1 0.5 0 0 1 0.2 2 0.9 1 0.4 3 0.6 3 0.7 1 0.9 4 0.4 difficult to used it 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 0 0.0 poor esthetics of appliances 2 0.9 2 0.7 4 0.8 0 0.0 0 0.0 0 0.0 2 0.5 2 0.4 4 0.4 don’t know 10 4.5 13 4.8 23 4.7 5 2.3 7 2.5 12 2.4 15 3.4 20 3.6 35 3.5 gender differences x2 = 29.972, d.f. = 9, p-value = 0.000, hs residency differences x2 = 23.909, d.f. = 9, p-value = 0.004,hs hs: highly significant p <0.01. urban rural total m n=221 f n=270 t n=491 m n=215 f n=285 t n=500 m n=436 f n=555 t n=991 n % n % n % n % n % n % n % n % n % crowded 63 28.5 61 22.5 124 25.1 60 27.9 74 26 134 26.8 123 28.2 135 24.3 258 26 spaced 61 27.6 88 32.6 149 30.2 36 16.7 79 27.7 115 23 97 22.2 167 30.1 264 26.6 protruded 39 17.6 63 23.3 102 20.6 58 27 62 21.8 120 24 97 22.2 125 22.5 222 22.4 rotated and displaced 59 26.7 60 22.2 119 24.1 65 30.2 71 24.9 136 27.2 124 28.4 131 23.6 255 25.7 gender differences x2 = 9.267, d.f. = 3, p-value = 0.026, s residency differences x2 = 7.239, d.f. = 3, p-value = 0.065, ns j bagh college dentistry vol. 27(3), september 2015 occlusal features pedodontics, orthodontics and preventive dentistry186 references 1proffit wr, field hw, sarver dm. contemporary orthodontics. 5th ed. st. louis, mosby year book; 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3(1): 32-7. 18abdulla nm. occlusal features and perception: a sample of (13-17) years old adolescent. a master thesis, college of dentistry, baghdad university, 1996. 19tak m, nagarajappa r, sharda aj, asawa k, tak a, jalihal s, kakatkar g. prevalence of malocclusion and orthodontic treatment needs among 12‑15 years old school children of udaipur, india. eur j dent 2013; 7: 45-53. 20al-zubair nm. perception of occlusion and reasons for not seeking orthodontic treatment among yemeni children. j orthod res 2014; 2(2): 68-37. 21hemapriya s, ingle na, chaly pe, reddy vc. prevalence of malocclusion and orthodontic treatment needs among 12 and 15 years old rural school children in kancheepuram district, tamilnadu. j oral health comm dent 2013; 7(2): 84-90. 22ansai t, miyazaki h, katoh y, yamashita y, takehara t, jenny j, cons nc. prevalence of malocclusion in high school students in japan according tothe dental aesthetic index. community dent oral epidemiol 1993; 21(5): 303-5. الخالصة .ھدف ھذه الدراسة تقییم التوزیع واالنتشار، شدة سوء االطباق في محافظة بغداد على أساس نوع الجنس واالقامة: الخلفیة م ن ) طالب ة 1351طال ب و 1349(طال ب 2700ض مت العین ھ . ددة المراحل تراصفیة قد استعلمت في ھذا البحث كي تجعل العین ھ ممثل ة للمجتم ع طریقة االنتخاب متع: المواد والطرق .من مجموع الطالب بھذا العمر% 3سنة یمثلون 13المدارس المتوسطة بعمر وآل ة verinerتمتعملیةالتقییملخواصاآلطباقبواسطةالفحصالسریریالمباشربأس تعمال ش مل البح ث اس تمارة اس تبیانیة لمعرف ة ادراك الطال ب الطباق ھ والطل ب عل ى المعالج ة التقویمی ة .لقیاساألستدارھواألنحراففیاألسنان . (%26.6)االجایة االكثر انتشارا حول نوع عدم انتظام االس نان كان ت االس نان المتباع دة بنس بة .غیر منتظمةمن الطالب أجابوا بأن عندھم أسنان %) 39.1: (واالستنتاجات النتائج األس باب األكث ر . تؤثر عل ى النط ق % 7.7تؤثر على مضغ الطعام و % 17.7أجابوا بأن أسنانھم تؤثر على مظھرھم و% 70.3فیما یتعلق باألجوبة حول تأثیر االسنان غیر المنتظمة من العینة ك ان ل دیھا س ن أو أكث ر مفق ود بس بب القل ع %) 4.9(%).48.8(والخوف من االلم %) 25.8(شیوعا لعدم طلب المعالجة التقویمیة كان اعتقاد الطالب بأن العالج لیس مھم لت أس نان متباع دة كان ت المنطق ة االمامی ة العلوی ة وأكث ر منطق ة أكث ر منطق ة ش م . أو التعرض الى صدمة خارجیة والسن المقلوع األكثر شیوعا ك ان الض رس االول ف ي الف ك الس فلي في الفك العل وي و % 18.36( التراكبات السنیة االمامیة .0.306من العینة بمعدل % 18.1الفتحة العلویة الوسطیة وجدت في . شملت أسنان متزاحمة كانت المنطقة االمامیة السفلیة م ن العین ة والص نف % 78.29ص نف االطب اق االول وج د ف ي . مل م 2.99مع دل العض ة للعین ة ك ان . مل م 3.31سنان االمامیة للعینة ك ان معدل بروز اال.)في الفك السفلي% 26.84 لخط الوس طي وج د انحراف ا%. 1.7العضة االمامیة المفتوحة في %. 5.6العضة الخلفیة المعكوسة وجدت في . من العینة% 2.3من العینة والصنف الثالث في % 19.5الثاني في م ن العین ة % 72.3التي سجلت في ھ ذه الدراس ة daiنتیجة ال.من العینة% 3.3اصطدام القواطع باللثة وجدت في .من العینة كان لدیھم شكل شفة طبیعي%) 86.6(%. 54.3في ل دیھم حاج ة الزامی ة % 4.5لدیھم حاجة شدیدة ال ى المعالج ة التقویمی ة و % 7.3و لدیھم حاجة اختیاریة الى المعالجة التقویمیة % 15.9لدیھم حاجة قلیلة الى المعالجة التقویمیة و وھ ذه البیان ات تك ون مفی دة لخدم ة ص حة الف م العام ة وللتأكی د .أیضا زیادة في الحاجة وقلة في الطلب على المعالجة التقویمیة بین المراھقین في مجتمع بغ داد .الى المعالجة التقویمیة .لتقویمیة بین المراھقین في بغدادة اعلى ضرورة المعالج 28. mohammed f.doc j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 168 the effect of acidity level on ions released and corrosion of metal orthodontic appliances at different time intervals (an in vitro study) mohammed r. thamer, b.d.s. (1) sami k. al-joubori, b.d.s., m.sc. (2) abstract background: this study measured the effects of three parameters ph value, length of immersion and type of archwire on metal ions released from orthodontic appliances. materials and methods: ninety maxillary halves simulated fixed orthodontic appliances that were immersed in artificial saliva of different ph values (6.75, 5 and 3.5) during 28 day period. three types of archwires were used: stainless steel, nickel titanium and thermal activated nickel titanium. the quantity of nickel and chromium ions was determined with the use of atomic force spectrophotometer while iron ions by spectrophotometer. each orthodontic set was weighted two times, before the ligation and immersion in the artificial saliva and after 28 days at the end of immersion period using analytic balance device. results: the release different metal ions was observed: nickel (ni), chromium (cr) and iron (fe)). statistically analysis of variance (anova) and t-test were used. results showed that (1) the appliances released measurable quantities ofall ions examined; (2) the change in ph had a very strong effect on the release of ions; (3) the release of ions was dependent on wire composition, but it was not proportionalto the content of metal in the wire and (4) orthodontic samples showed decreases in the weight at the end of the study. conclusion: levels of released ions are sufficient to cause delayed allergic reactions. this must be taken into account when type of archwire is selected, especially in patients with hypersensitivityor compromised oral hygiene. key words: orthodontic appliances, ions released, ph. (j bagh coll dentistry 2015; 27(4):168-174). introduction there is increasing concern about the biocompatibility of dental materials and, therefore, this topic has been widely investigated during recent years (1). fixed orthodontic appliances usually include brackets, bands, and archwires made of stainless steel (containing approximately 18% chromium and 8% nickel) or nickel-titanium (where nickel content exceeds 50%). these alloys have to be fully biocompatible and must elicit an appropriate biological response within a host (2). since orthodontic fixed appliances have become popular, the question about the quantity and potential cytotoxicity of released metal ions is still valid (3). “warning: this product contains nickel and/or chromium. a small percentage of the population is known to be allergic to nickel and/or chromium. if an allergic reaction occurs, direct the patient to consult a physician”. this common information on orthodontic product labels makes research on the biocompatibility of orthodontic appliances a timely issue (4). several methods can be used to evaluate the release of metal ions from dental alloys: in vitro (e.g., in the environment of artificial saliva or tissue culture (6,7) and in vivo experiments with the application of invasive (e.g., blood) (8) or non (1)master student. department of orthodontics, college of dentistry, university of baghdad. (2)assistant professor, department of orthodontics, college of dentistry, university of baghdad. invasive matrices (e.g., saliva, hair, urine) (9-13). none of the abovementioned methods is able to reflect the real, changeable, complex environment of the human oral cavity. electrochemical reactions during which the surface of a metal is deteriorated via ion release are called corrosion. internal corrosive factors are determined by metal composition and structure; external factors depend on biological surroundings (e.g., media composition, ph, temperature, strain, illumination) (12). the oral environment is conducive to biodegradation and corrosion of dental materials caused by constant chemical, mechanical, thermal, microbiological, and enzymatic changes(14). the mouth is moist and has a fluctuations in temperature. the liquids and food ingested have wide ranges of ph. acids are released during breakdown of food stuffs. this food debris adheres strongly to the metals providing a condition that is highly conducive to the accelerated reaction between the oral media and the metal or alloy (15,16). nickel is the most common cause of contact allergy (17). orthodontic brackets, bands, and archwires are universally made with an alloy, which contains approximately 6% to 12% nickel and 15% to 22% chromium (6). in addition to the allergic issue, carcinogenic, mutagenic, and cytotoxic effects have been assigned to nickel and, to a lesser extent, chromium. the introduction of metal ions into the human body is an additional risk to health since these j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 169 ions may be released in different places and at different levels, depending on the characteristics and solubility of the products containing them (18). consequently, biological functions are affected, which may lead to systemic and local effects (19). several studies have demonstrated that metal ions from fixed orthodontic appliances, primarily nickel and chromium, can cause allergic reactions(20-22). other reports have indicated that 4.5% to 28.5% of the population is nickel hypersensitive, and this condition is more prevalent among females. this might be so because women could have been sensitized by wearing jewelry that contains nickel (23,24). besides allergic reactions, metal ions released from orthodontic appliances could have carcinogenic, mutagenic, and cytotoxic effects (25). the purpose of the present study was to determine the quantities of three metal ions (nickel, chromium and iron) released from three different metal orthodontic appliances of three types of archwires (stainless steel [ss], nickeltitanium [niti] and thermal activated nickeltitanium in artificial saliva of three different ph values (to simulate saliva and conditions in the presence of dental plaque). furthermore, the effects of change in ph and time of exposure on release of metal ions from these different alloys were evaluated. materials and methods the samples used in the present study represents half fixed orthodontic appliances and consisted of first molar band of similar sizes, five orthodontic stainless steel brackets from second premolar to central incisor and archwire tied to the brackets using elastomeric ligature all orthodontic materials made by orthotechnology, usa. the ninety orthodontic samples were divided into three groups according to the type of orthodontic archwires used: astainless steel, b nickel titanium and cthermal activated nickel titanium. the 0.016 × 0.022 inch archwires were cut into 6 cm long and were shaped to an ideal arch form according to ideal study model (apexion, india). each groups were subdivided again into three subgroups according to the ph of artificial saliva that were immersed in it, so each subgroup has ten sets. the artificial saliva which is used in this study consisted of 0.7g nacl , 1.2g kcl , 0.26g na2hpo4 , 0.2g k2hpo4 , 1.5g nahco3 , 0.33g kscn , 0.13g urea and 1000 ml deionized water, this formula is named modified carter’s solution which is a modification to the old one used by gerdet and hero (15). to simulate changing conditions in the oral cavity, artificial saliva of different ph values was used; selection was based on average ph in the oral cavity (6.75) (26), lowest ph (3.5) found under mature dental plaque (27) and ph 5 was selected in between them (28). lactic acid was used to adjust the ph of artificial saliva using the ph-meter (jenway, model 3320, cyprus) and maintained in 37°c using incubator after filtering using filter paper to get rid of any insoluble salts and impurities. each orthodontic set was cleaned ultrasonically and washed in deionized water using ultrasonic cleaner, immersed in 70% ethanol for 4-5 seconds, then immersed in deionized water and finally in acetone (which act as volatile organic solvent) for 8-10 seconds, dried in hot air and finally stored in closely packed plastic bags which contain silica gel particles to avoid any oxidation and contamination of the alloy. this method of cleaning used to remove any contaminants or oxide layer formed on the alloy during storage. this method used according to american society for metals and alloys (29). neither the inner surface of the bands nor the mesh of the brackets were covered by any material. the exposed surface area of the appliance components was approximately equal to the exposed surface area of the bonded and banded full arch fixed orthodontic appliance (29). each set was ligated by dental floss mesial to molar band and placed in a glass container contain 35ml of artificial saliva according to its group in such a way that the sample was fully immersed in the artificial saliva without touching the walls of the container. each container was closed by parafilm to control evaporation. the glass containers were placed in the incubator at 37°c for 28 days (29). collection of solutions was done by aspiration 1ml of artificial saliva using mechanical micro pipette at 1, 7, 14, 28 days and directly read for ions concentrations. the artificial saliva was prepared for estimation of ions concentration included nickel and chromium using atomic absorption spectrophotometer (analytikjena, novaa 300, germany) and iron concentration using spectrophotometer (cecil, model 1011, france). atomic absorption spectrophotometer is an analytical method for determination of elements and it is applicable for the analysis of concentrations ranging from trace up to large concentration following standardized procedure. each orthodontic set was weighted two times, the first time was before the ligation and immersion in the artificial saliva and the other j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 170 after 28 days at the end of immersion period using analytic balance device (precisa, model xb220a, switzerland). the analysis of variance (anova) used to test statistically significant difference between the amounts of ions released according to the periods, medium acidity and the samples composition. ttest used for weight comparison before and after immersion. results and discussion effects of different ph of artificial saliva on ions released: the effects of different acidity on the ions released from the orthodontic sets used in this study appeared to be marked over the storage periods. the larger amount of chromium, nickel and iron ions were released in the artificial saliva with highest acidity ph 3.5 then followed by the one with ph 5 and finally in the one with neutral ph 6.75. in table 1, the results of (anova) test showed very highly significant difference on the nickel ions released. in the (table 2) the results (anova) has demonstrated a very highly significant difference on the chromium ions released in the all acidity of artificial saliva in any periods of any orthodontic sets group. by inspecting the result of (anova) test in table 3, it can be seen that there were very highly significant difference on the iron ion release in all acidity in any group. this study demonstrate the importance of many factors that can affect the release of metal ions from fixed orthodontic appliances such as the type of alloy, immersion period and the ph of the solution. the appliance consisted of the brackets and wires, and it is likely that the brackets contributed to the quantities of released ions. however, because the brackets consisted of the same material in all samples, their contribution was constant and did not influence relative comparisons of ions released from wires. the present study showed that the release of ni, cr and fe ions depended not only on the ph value of the solution, but also on the length of exposure and, to a smaller degree, on the material that made up the archwire used. although the quantities of released metal ions measured in this and similar studies cannot be directly applied to in vivo conditions, they are useful for relative comparisons and for determination of the effect of each individual variable (e.g., ph) on ion release without the influence of external factors. other studies have suggested that the quantity of released metal ions is not proportional to the content. it is important to note that the oral environment is extremely conducive to the corrosion products formation, because the mouth is moist and always subjected to changes in temperature. saliva acts as an electrolyte, which can cause corrosion. foods and drinks cause transitory, but important and wide, variations in the chemistry of the environment, as the ingested food and liquids have wide ranges of ph. during breakdown of foodstuffs, acids are liberated. this food debris often adheres strongly to the metals in the mouth providing a localized condition that is highly conducive to the reaction between the oral media and the metal or alloy (16,30). the higher levels of ions were released in artificial saliva of ph 3.5 followed by artificial saliva of ph 5 and the least amount of ions was released in neutral artificial saliva of ph 6.75 in the different groups, so the levels of released ions were gradually increased with decreasing solution ph. these results confirm the hypothesis that low ph values reduce the resistance of dental alloys to corrosion (14).the metal ions released was more when the brackets were placed in an acidic environment (12). these results agree with the finding of (31). while our findings disagree with the result of duffó and farina (16) who showed that the aggressiveness of the different liquids is independent on the ph of the solution. this finding may be due to the decrease in the stability of titanium dioxide (tio2) of niti based alloy surfaces, and so decreasing their corrosion resistance with the increase of h+ concentration(32,33). for stainless steel alloy this occurred also because the acidic condition provide a reducing environment in which the stainless steel oxide film required for corrosion resistance is less stable (9). the results in figure 1 showed that all orthodontic appliances groups of different archwires decreased in weight after immersion in different acidity of artificial saliva at the end of the study when compared to zero line (specimens weight before immersion in artificial saliva). the reduction in the weight of the appliances might occur because of the released of some ions in artificial saliva in acidic condition provide a reducing environment in which the metal oxide film required for corrosion resistance is less stable(9). to sum up; 1. the effects of acidity of the medium were significantly influenced ions released. the release of ions was increased with decreasing the ph of the solutions, this indicating the breakdown of protective metals film by low ph of acids j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 171 2. the measurable amounts of metal ions released in artificial saliva was clearly below the average dietary intake and far from the toxic concentrations, but it might be enough to cause delayed allergic reactions. 3. the findings of this study indicated that in nickel-sensitive patients, use of thermal activated niti wires should be preferred to nickel-titanium archwires. 4. weighing the orthodontic samples revealed that there were decreases in the weight of the orthodontic appliances in all studied groups at the end of the study. table 1: descriptive statistics and effect of ph on the ni release highly significant p ≤ 0.01 groups duration ph descriptive statistics ph difference mean s.d. min. max. f-test p-value a 1 day 3.5 566.30 7.99 557 578 42657.987 0.000 5 37.59 1.05 35.7 39.1 6.75 24.34 1.52 22.7 26.7 7 days 3.5 1321.40 7.85 1310 1334 234426.012 0.000 5 54.00 1.82 50.9 56.7 6.75 38.75 2.11 36.8 41.7 14 days 3.5 1537.00 5.89 1527 1547 522371.102 0.000 5 59.70 1.92 57.2 63.1 6.75 42.50 1.98 39.6 45.2 28 days 3.5 2136.00 7.42 2126 2147 654565.192 0.000 5 71.07 2.61 66.6 75.5 6.75 55.20 1.93 52.3 58.2 b 1 day 3.5 458.70 7.51 450 468 31184.830 0.000 5 33.40 1.55 30.9 35.3 6.75 22.59 0.82 20.7 23.6 7 days 3.5 1146.50 11.36 1130 1159 91650.258 0.000 5 47.95 1.50 46.1 50.9 6.75 34.16 1.47 32.02 36.5 14 days 3.5 1461.70 6.77 1451 1471 404408.068 0.000 5 55.14 1.47 52.6 58.2 6.75 40.85 1.21 38.7 43.1 28 days 3.5 1855.07 7.26 1844 1868 506530.719 0.000 5 65.96 2.04 62.1 69.1 6.75 47.19 2.64 43.2 51.3 c 1 day 3.5 428.05 6.73 420.5 438 33643.712 0.000 5 32.79 1.39 30.4 35.2 6.75 21.94 0.68 20.9 23.2 7 days 3.5 1036.60 9.37 1020 1048 106975.254 0.000 5 40.68 1.91 37.21 43.8 6.75 31.84 1.44 29.9 34.4 14 days 3.5 1256.80 6.86 1243 1265 279175.531 0.000 5 47.41 1.89 44.9 50.8 6.75 35.15 1.51 32.6 37.9 28 days 3.5 1353.44 9.17 1343.4 1368 167952.067 0.000 5 56.20 2.55 52.4 59.6 6.75 45.45 3.24 40.9 51.5 j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 172 table (2): descriptive statistics and effect of ph on the cr release groups duration ph descriptive statistics ph difference mean s.d. min. max. f-test p-value a 1 day 3.5 130.51 1.21 128.7 132.3 56280.714 0.000 5 28.2 0.97 26.2 29.4 6.75 3.312 0.10 3.16 3.44 7 days 3.5 201.7 1.50 199.2 203.8 88723.375 0.000 5 47.055 1.15 45.55 48.8 6.75 6.054 0.11 5.88 6.21 14 days 3.5 238.34 2.85 232.4 241.7 40897.491 0.000 5 55.635 1.58 53.1 57.5 6.75 8.015 0.44 7.45 8.79 28 days 3.5 283 3.62 278 288 43468.858 0.000 5 63.5 1.13 62 65 6.75 9.89 0.25 9.4 10.3 b 1 day 3.5 86.15 2.40 82.4 89.8 9222.245 0.000 5 24.695 0.49 24.05 25.4 6.75 3.37 0.13 3.1 3.5 7 days 3.5 140.02 1.14 138.6 141.9 43272.016 0.000 5 40.13 1.44 37.7 42.1 6.75 5.52 0.13 5.32 5.74 14 days 3.5 170.82 2.02 167.1 173.4 32196.971 0.000 5 52.865 1.54 51.15 55.6 6.75 7.651 0.39 7.11 8.04 28 days 3.5 203.6 5.40 196 209 9918.405 0.000 5 56.8 1.40 54.5 59 6.75 8.55 0.32 8.1 9.1 c 1 day 3.5 81.38 1.71 79.3 84.1 15902.460 0.000 5 25.165 0.46 24.25 25.75 6.75 1.988 0.09 1.88 2.12 7 days 3.5 126.62 2.69 123.4 130.5 14387.964 0.000 5 38.975 1.00 37.1 40.25 6.75 4.356 0.15 4.13 4.57 14 days 3.5 165.67 1.66 163.2 168.2 48302.264 0.000 5 45.56 1.21 43.7 47.65 6.75 5.742 0.28 5.32 6.12 28 days 3.5 202.6 3.34 197 206 24718.958 0.000 5 51.05 1.21 49.5 53 6.75 7.05 0.38 6.4 7.6 highly significant p ≤ 0.01 j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 173 table (3): descriptive statistics and effect of ph on the fe release groups duration ph descriptive statistics ph difference mean s.d. min. max. f-test p-value a 1 day 3.5 174.81 6.82 166.78 186.05 1408.298 0.000 5 74.60 4.46 65.78 81.06 6.75 67.56 3.20 62.46 71.10 7 days 3.5 484.44 6.17 478.18 494.55 23363.22 0.000 5 78.96 3.82 72.50 84.34 6.75 85.90 4.06 80.00 93.33 14 days 3.5 845.36 5.94 838.06 852.69 65370.98 0.000 5 126.37 3.35 122.39 132.09 6.75 119.55 5.78 111.19 128.36 28 days 3.5 1060.37 5.24 1053.76 1069.23 108445.7 0.000 5 179.13 3.98 171.74 184.06 6.75 163.13 5.44 154.68 170.50 b 1 day 3.5 168.09 5.36 160.13 178.07 1376.332 0.000 5 75.72 4.15 70.43 81.73 6.75 63.59 5.03 58.47 71.76 7 days 3.5 459.88 5.88 452.97 469.01 22312.31 0.000 5 77.30 4.83 68.81 82.96 6.75 79.39 2.71 75.51 83.67 14 days 3.5 802.92 4.94 796.26 810.49 85401.68 0.000 5 119.57 3.60 114.39 125.18 6.75 108.61 4.27 100.79 114.96 28 days 3.5 1019.76 5.98 1011.72 1027.62 79588.67 0.000 5 175.04 4.61 169.13 182.52 6.75 152.55 5.92 143.93 159.83 c 1 day 3.5 168.99 4.83 160.80 176.74 1599.978 0.000 5 70.60 4.25 65.12 77.74 6.75 63.65 4.87 57.81 70.43 7 days 3.5 428.47 5.37 421.81 437.36 19043.62 0.000 5 76.96 4.30 71.35 83.04 6.75 78.10 4.16 72.38 85.71 14 days 3.5 766.42 5.65 761.08 779.14 65081.9 0.000 5 108.51 4.65 100.00 113.39 6.75 102.25 3.69 97.76 108.21 28 days 3.5 914.22 3.39 909.45 919.69 156983.5 0.000 5 161.24 3.69 155.81 167.44 6.75 139.83 3.47 132.22 145.61 highly significant p ≤ 0.01 figure (1): mean distribution of weight of different studied groups before and after immersion in different acidity of artificial saliva j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 174 references 1. menezes lm, quintao ca, bolognese am: urinary excretion levels of nickel in orthodontic patients. am j orthod dentofac orthop 2007; 131:635-8. 2. o’brien wj. dental material and their selection. chicago: quintessence int; 1997 p.215-24. 3. karnam sk, reddy an, manjith cm. comparison of metal ion release from different bracket archwire combinations: an in vitro study. j contemp dent pract 2012; 13(3):376-81. 4. mikulewicz m, wołowiec p, janeczek m, gedrange t, chojnacka k. the release of metal ions from orthodontic appliances animal tests. angle orthod 2014; 84(4):673-9. 5. bishara se, barrett rd, selim mi. biodegradation of orthodontic appliances. part ii. changes in the blood level of nickel. am j orthod dentofac orthop 1993; 103:1159. 6. matasa cg. attachment corrosion and its testing. j clin orthod 1995; 29:16-23. 7. vonfraunhofer ja. corrosion of orthodontic devices. seminorthod 1997; 3:198-205. 8. barceloux dg: nickel. j toxicol clin toxicol 1999; 37:23958. 9. staffolani n, damiani f, lilli c, et al. ion release from orthodontic appliances. j dent 1999; 27:449-54. 10. house k, sernetz f, dymock d, et al: corrosion of orthodontic appliances—should we care? am j orthod dentofac orthop 2008; 133: 584-92. 11. amini f, borzabadifarahani a, jafari a, et al. in vivo study of metal content of oral mucosa cells in patients with and without fixed orthodontic appliances. orthod craniofac res 2008; 11:51-6. 12. kuhta m, pavlin d, slaj m, et al. type of archwire and level of acidity: effects on the release of metal ions from orthodontic appliances. angle orthod 2009; 79:102-10. 13. eliades t, zinelis s, papadopoulos ma, et al. nickel content of as-received and retrieved niti and stainless steel archwires: assessing the nickel release hypothesis. angle orthod 2004; 74:151-54. 14. barrett rd, bishara se, quinn jk. biodegradation of orthodontic appliances. part i. biodegradation of nickel and chromium in vitro. am j orthod dentofac orthop 1993; 103:8-14. 15. duffó gs, quezada ce. development of an artificial saliva solution for studying the corrosion behavior of dental alloys. corrosion 2004; 60:595-9. 16. duffó gs, farina sb. corrosion behavior of a dental alloy in some beverages and drinks. mater chem phys 2009; 115: 235-8. 17. kerosuo h, kullaa a, kerosuo e, kanerva l, hensten-pettersen a. nickel allergy in adolescents in relation to orthodontic treatment and piercing of ears. am j orthod dentofac orthop 1996; 109:148–54. 18. savarino l, granchi d, ciapetti g, et al. ion release in patients with metal-on-metal hip bearings in total joint replacement: a comparison with metalonpolyethylene bearings. j biomed mater res 2002; 63: 467–74. 19. kusy rp. clinical response to allergies in patients. am j orthod dentofac orthop 2004; 125: 544–7. 20. ramadan aa. effect of nickel and chromium on gingival tissues during orthodontic treatment: a longitudinal study.world j orthod 2004; 5:230–4. 21. schultz jc, connelly e, glesne l, warshaw em. cutaneous and oral eruption from oral exposure to nickel in dental braces. dermatitis 2004; 15:154–7. 22. al-waheidi em. allergic reaction to nickel orthodontic wires: a case report. quintessence int 1995; 26: 385–7. 23. peltonen l. nickel sensitivity in the general population. contact dermat 1979; 5: 27–32. 24. wilkinson jd, rycroft rjg. contact dermatitis. in: champion rh, burton jl, ebling fjg. textbook of dermatology. 5th ed. oxford: blackwell scientific publications; 1992. p. 648–729. 25. cortizo mc, de mele mfl, cortizo am. metallic dental material: biocompatibility in osteoblast like cells: correlation with metal ion release. biol trace elem res 2004; 100:151–68. 26. afonsky d. saliva and its relation to oral health. j dent res 1984; 63(5):101-5. 27. cawson ra, odell ew. essentials of oral pathology and oral medicine. 7th ed. hong kong: churchill livingstone; 1998. p.36–52. 28. huang hh, chiu yh, lee th, wu sc, yang hw, su kh, hsu cc. ion release from niti orthodontic wires in artificial saliva with various acidities. biomaterials 2003; 24:3585-92. 29. al-joboury hm. the corrosion behavior and the biological effect of fixed orthodontic appliance in artificial saliva solution. a master thesis, orthodontic department, college of dentistry, university of baghdad, 2001. 30. oh kt, kim kn. ion release and cytotoxicity of stainless steel wires. eur j orthod 2005; 27: 533-40. 31. elshahawy w1, watanabe i, koike m. elemental ion release from four different fixed prosthodontic materials. dent mater 2009 ; 25: 976-81. 32. pourbaix m. atlas of electrochemical equilibria in aqueous solutions. brussels: nace; 1987. 33. afshar a, shirazi mr, fakheri e. effects of temperature and ph on the corrosion behavior of niti orthodontic archwire in artificial saliva. in: proceedings of the 16th international corrosion congress; 2005. j bagh college dentistry vol. 28(4), december 2016 sex variations by oral diagnosis 82 sex variations by linear measurements of palatal bones and skull base using 3d reconstructed computed tomographic scan among iraqi sample noora a. abdul ameer, b.d.s. (a) ahlam a. fatah, b.d.s., m.sc. (b) abstract background: the skull base and the hard palate contain many anatomical features that make them rich in information which are useful in sex differentiation; in addition to that they have the ability to resist the hardest environmental conditions that support them in making sex differentiation. three dimensional computed tomographic techniques has important role in differentiation between sex since it offers images with very accurate data and details of all anatomical structures with high resolution. this study was made to study sex variations among iraqi sample by craniometric linear measurements of the hard palate and the skull base using 3d reconstructed computed tomographic scan. materials and methods: this study composed of 100 iraqi subjects (50 male and 50 female) aged between 20-59 years. the sample collected from patients attending al-shaheed ghazi hospital in baghdad city to for spiral ct scanner. the craniometrical linear measurements of the hard palate and the skull base in this study were including: maxillo-alveolar breadth, maxillo-alveolar length, the distance between incisive foramen and greater palatine foramen (right and left), the distance between the incisor foramen and b point (the median point located at the anterior area of the magnum foramen), the distance between the incisor foramen and the anterior root of the mastoid notch on both sides (right and left), maxillo-alveolar index and size of palate. all these measurements were done by (mm) unit. results: the statistical analysis of linear measurements of the hard palate and the skull base showed that the mean values of all measurements were significantly higher in males than females except for maxillo-alveolar index was not significant and also showed that the size of the palate was the best indicator for sex variation and making the diagnosis of male with accuracy 93.3%. the age had none significant effect on these measurements. conclusion: three dimensional computed tomographic scanners is the best diagnostic tool for sex variation by the craniometrical linear measurements for the anatomical landmarks points of the hard palate and the skull base. key words: sex variations, 3d reconstructed computed tomography, palatal bones, skull base. (j bagh coll dentistry 2016; 28(4):82-88) introduction sexual dimorphism has been defined as the systematic variation in form between subjects of different sex in the same species. in spite of any human being can distinguish the variations by appearance, but it’s stated that human beings have comparatively lower level of dimorphism when compared to other species.. some of the other factors influencing the dimorphism among humans can be height, weight, hair, face, muscles (more among men than women) (1). the identification of an individual through sex determination is very important since many skeletal features vary by sex (2). although the sex is best evaluated from the pelvis but the skull also provides a number of very good sex indicators and is usually better preserved (3). human skulls of adult individuals are consisting from a set of bones which have more information that can be used in sexual dimorphism (4). (a) m.sc. student. department of oral diagnosis, college of dentistry, university of baghdad. (b) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. the skulls of males had significantly, heavier, thicker and larger bones in addition to having greater cranial capacity, whereas the skull of females tend to be smaller and smoother (4,5). the determination of sex can be made from isolated bony pieces such as the frontal, temporal bone, in orbit and in jaw, by calculating of general cranial dimensions and measuring the angles among craniometrics points (6,7). when the sexual dimorphism of individual bones of the skeleton had been studied, these bones should be the most resistant and protected from damage. this will help in determination of sex in a higher accuracy determination. bony and dental structures of the palate often are preserved even in the face of serious bodily damage at or following death (2). male proportions of the skull tend to be larger than their female, so the establishment of the sex differentiation parameter, based on anatomic points present when the skull base is visualized, since the male palate is larger than the female's (8, 9). the cranial base is considered to be the most durable region of the skull and is known to be the best sexually dimorphic (10,11). computed tomographic scanner is a machine that composed from an x-ray tube that j bagh college dentistry vol. 28(4), december 2016 sex variations by oral diagnosis 83 responsible for emission of a finely collimated, fan-shaped x-ray beam directed through a patient to a series of scintillationdetectors or ionization chambers and thesedetectors measure the number of photons that exitthe patient. this information can be used to produce a cross-sectional image of the patient (12,13). 3d-ct imaging has been considered to be more efficient and accurate in determining the linear measurements between anatomical points (14,15). materials and methods a prospective study composed of 100 iraqi subjects (50 male and 50 female) aged between 20-59 years were analyzed. the sample collected from patients attending al-shaheed ghazi hospital in baghdad city to have spiral ct of the brain and paranasal sinus for different diagnostic purpose from november 2014 to april 2015. the study sample divided into four groups as shown in table 1. table 1: the distributions of sample according to age and sex female male age range groups 15 15 20-29 a 15 15 30-39 b 14 14 40-49 c 6 6 50-59 d 50 50 total any subjects with physical damage, apparent deformity, abnormalities and severe systemic diseases that affect bone metabolism are excluded, also any subjects having missing maxillary central incisors and maxillary second molars are excluded from this study. the examination was performed on multi-slice spiral tomography scanner (siemens soma tom definition as). patients were asked to remove all accessories like: ear rings, necklaces, hairpins and hearing aids before the exposure, then patient asked to lay down in supine position on the ct examination table and his head positioned on head set. three dimensional reconstructed computed tomographic images of palatal bones and skull base are analyzed in linear measurements between bony anatomical landmarks and all these linear measurements were done on axial section by (mm) unit. the bony landmarks points were including (16, 17): 1. alveolon a: the point locates where the midsagittal plane crosses a straight line drawn from the posterior margins of the alveolar processes of the maxilla. 2. prosthion p: the point locates on the most anterior of the alveolar border of the maxilla in the mid-sagittal plane between the central incisors. 3. incisor point (incisive foramen) if: the central point located in the hard palate between the maxillary central incisors from the lingual borders of the alveolar processes. 4. greater palatine foramen gpf: is the point locates at the palatine bones from the posterolateral region and there are two foramen (left and right) each one locates in palatine bone. 5. basion b: the median point locates at the inferior surface of the skull at the most anterior border of the magnum foramen. 6.mastoid point mp: the point locates on anterior root of mastoid notch; which is on the medial side of the mastoid process the linear measurements between landmarks points: 1. maxillo-alveolar breadth (mab): the maximum breadth of the maxilla across thealveolar borders that measured on the lateral surfaces at the area of the maxillary second molars as shown in fig (1) 2. maxillo-alveolar length (mal): the direct distance from prosthion to alveolon. line is measured from prosthion point to the middle of the straight line drown across the posterior borders of the alveolar processes of the two sides (alveolon), in the mid-sagittal as shown in fig (2). 3. incisive foramen greater palatine foramen (ifgpf): the distance between incisive foramen and greater palatine foramen (right and left)as shown in fig (3). 4. incisive foramen-basion (if-b): distance between the incisive foramen and the basion point the median point located at the anterior area of the magnum foramen) as shown in fig (4). 5. incisive foramenmastoid notch (if-mn): distance between the incisive foramen and the anterior root of the mastoid notch on both sides (right and left) as shown in fig (5). 6. maxillo-alveolar index mai: resulted from division of maxilla-alveolar breadth on maxillaalveolar length then multiply by 100(18). maxilo-alveolar index= mab/ mal * 100 7. size of palate: resulted from multiplication of maxillo-alveolar breadth and maxillo-alveolar length then divided on 100(19). size of palate= mal * mab/100 statistical analyses data were translated into a computerized database structure. an expert statistical advice was sought for. statistical analyses were computer j bagh college dentistry vol. 28(4), december 2016 sex variations by oral diagnosis 84 assisted using spss version 21 (statistical package for social sciences). the linear measurements of the palatals bones and the base of the skull were described by mean, sd (standard deviation) and se (standard error), and the parametric statistical tests of significance were used. figure 1: 3d reconstructed axial view of ct image showing of maxillo-alveolar breadth. figure 2: 3d reconstructed axial view of ct image showing of maxillo-alveolar length figure 3: 3d reconstructed axial view of ct image showing of incisive foramen greater palatine foramen (right and left) figure 4: 3d reconstructed axial view of ct image showing of incisive-basion line figure 5: 3d reconstructed axial view of ct image showing of incisivemastoid line (right and left) results the sex differences in means of linear measurements between anatomical landmarks of hard palate and skull base: the mean values of all the linear measurements of the palatals bones and the base of the skull were higher among males than that among females and were statically significant p <0.001 excepted for maxillo-alveolar index that was non-significant p = 0.17. all the linear measurements have strong effect ofsexual differentiation (cohen's d) excepted for maxillo-alveolar index weak effect as shown in tables j bagh college dentistry vol. 28(4), december 2016 sex variations by oral diagnosis 85 table 2: the gender difference in mean of maxillo-alveolar breadth genders difference in means cohen's d p-value sexual dimorphism females males range (57.6 66.9) (62.9 72.6) 4.7 2.18 0.001 7.6 mean 62 66.7 sd 2.3 2 se 0.32 0.28 n 50 50 table 3: the gender difference in mean of maxillo-alveolar length genders difference in means cohen's d p-value sexual dimorphism females males range (47.7 57.9) (53.2 62.7) 4.7 1.17 0.001 8.9 mean 52.8 57.5 sd 2.8 2.7 se 0.4 0.38 n 50 50 table 4: the gender difference in mean of incisive foramen-basion genders difference in means cohen's d p-value sexual dimorphism females males range (76.7 90.9) (84 95.3) 5.4 2.1 0.001 6.4 mean 84.2 89.6 sd 2.9 2.2 se 0.42 0.32 n 50 50 table 5: the gender difference in mean of size of palate genders difference in means cohen's d p-value sexual dimorphism females males range (28.1 – 37.4) (34.5 – 45.5) 5.7 2.24 0.001 17.4 mean 32.7 38.4 sd 2.6 2.5 se 0.37 0.36 n 50 50 table 6: the gender difference in mean of maxillo-alveolar index genders difference in means cohen's d p-value sexual dimorphism females males range (106.3 128.5) (103.1 124.4) -1.4 -0.27 0.17 (ns) -1.2 mean 117.6 116.2 sd 5.3 4.9 se 0.74 0.69 n 50 50 table 7: the gender difference in mean of incisive foramengreater palatine foramen genders difference in means cohen's d p-value sexual dimorphism females males range (36.7 43.9) (39.3 49.7) 2.4 1.26 0.001 5.9 mean 41 43.4 sd 1.8 2 se 0.25 0.28 n 50 50 j bagh college dentistry vol. 28(4), december 2016 sex variations by oral diagnosis 86 table 8: the gender difference in mean of incisive foramenmastoid notch genders difference in means cohen's d p-value sexual dimorphism females males range (95.3 109.3) (103.9 117.9) 5.4 1.72 0.001 5.6 mean 103.6 109.2 sd 3.3 3.2 se 0.46 0.45 n 50 50 multiple logistic regression model for the probability of being male the multiple logistic regression model was used to predict the probability of being a male gender based on selected skull measurements. a forward step slection algorithm was used to select only those measurements that significantly contributed to the predictive power of the logistic model. only 2 variables, namely “maxillo-alveolar breadth” and “incisive foramen-basion length” were enough to provide an overall accuracy of 94% for gender prediction, for each one mm increase in “maxillo-alveolar breadth” the probability of being a male gender is increased by 4.9 times after adjusting (controlling) for the confounding effect of “incisive foramen-basion length” measurement. similarly for each one mm increase in “incisive foramen-basion length” the probability of being a male gender is increased by 3.5 times after adjusting (controlling) for the confounding effect of “maxillo-alveolar breadth”, as shown in table 10. table 10: multiple logistic regression model for the probability of being male (forward selection algorithm) partial or 95% or p maxillo-alveolar breadth 4.9 1.9-12.5 0.001 incisive foramen basion 3.5 1.6-7.8 0.002 overall predictive accuracy = 94% p (model) <0.001 power=-212.596 + (1.588 * mab) + (1.261 * if_b) calculated probability for being a male=e (power)/ [1+e (power)] discriminant analysis results of sex variation by linear measurements of palatal bones and skull base: all the linear measurements of the palatal bones and the skull base were used together in discriminant model to differentiate between females and males. the resulting equation was statistically significant (p (model) <0.001) with overall prediction accuracy 93% and wilks' lambda=0.365. the resulting discriminant score (d score) from using the equation could be used in predicting gender if d>0 male is expected, while a negative value indicates a female gender. the more extreme is the value of discriminant score (d) in a positive direction the more probable is a prediction of male gender. in this discriminant model maxillo-alveolar breadth was the best discriminating variable then incisive foramen-basion. the validity of selected linear measurements in predicting male sex: receiver operating characteristic analysis (roc) was used to evaluate the validity of various tested linear measurements in predicting male sex variation from female. as shown in table (3.15) and among the computed tomographic linear measurements it was found that size of palate was the first value with the highest validity in predicting male sex with (roc area = 0.955)as shown in table 11. table 11: roc area for selected linear measurements in predicting male sex variables roc area p size of palate 0.955 <0.001 maxillo-alveolar breadth 0.951 <0.001 incisive foramen-basion 0.949 <0.001 incisive foramenmastoid notch 0.899 <0.001 maxillo-alveolar length 0.889 <0.001 incisive foramen-gpf 0.834 <0.001 maxillo-alveolar index 0.586 0.14[ns] there was no statistical significance difference in the mean values of the all selected linear measurements between all age groups, so there was no effect of age on these measurements for males and females discussion sexually dimorphic characters of the skeleton having a fundamental importance in constructing a biological profile from unidentified human's bony remains, thus the skull exhibiting prominent sexually dimorphic features that are reliable indicators of sex evaluation in cases where a complete skeleton have been available for differentiation (20,21). j bagh college dentistry vol. 28(4), december 2016 sex variations by oral diagnosis 87 the palate is considered to be an essential region of the skull and composed from two horizontal plates of palatal bone and two palatal processes of maxilla, all of which are connected together by a suture (23,24), thus the palate is a significant indicator for the sex variation (22,23). multi slices computed tomography represents the latest revolution in ct technology and breakthrough in forensic medicine. it has transformed ct from a transaxial cross-sectional technique (conventional ct) into a truly threedimensional imaging modality (3d-ct) with a different clinical applications mainly in musculoskeletal imaging (24), in addition to that 3d-ct allows studying of the anatomic structures and macroscopic content of the body while preserving the integrity of the human remains and also the images are very similar and nearest to the original images of the bone shape that require to be measured, in any axis and in rapid manner (25). since 3d ct images have importance role in quantitative and qualitative analysis the present study 3d reconstructed computed tomography was used to assess sex variation through selected measurements calculated between anatomical points of hard palate and between hard palate and skull base for iraqi population, thus this process offers better information about craniofacial complex to be recognized and computer workstations permit better visualization, details and segmentation that allow evaluation of volume, area, angular and linear measurements that can be obtained by calipers, simple rulers and other specific tools (26,27). in the current study, the means of the linear measurements were significantly higher in males than that in females and it was found that among all these measurements the size of palate had the strongest effect in sex variation (cohen's d) and the sexual dimorphism was the highest among all measurements. sumati et al. (2) found that the size of palate is the best predictor for sex determination among the hard palate variables and the size of palate alone correctly classified 70.0% of the cases which is equivalent to the correct classification rate of all hard palate variables. larnach and freedman (28) stated that the size of palate among the seven characters of the skulls showed maximum contrast between the sexes, and concluded that the value of size of palate is important for sex determination. for maxillo-alveolar breadth and maxillo-alveolar length the mean values were significantly higher in males than that for females and both of them had strong effect of cohen's d, this had agreement with results of other studies (29,30). the mean value for maxilla-alveolar index was not statistically significant, although it was higher in females than males but the difference in means was very little, so this index was not used in sex determination, this result come in accordance with result of study done by patel and manmohan (31). in the present study, the multiple logistic regression model was used to predict the probability of being a male gender based on selected hard palate and skull linear measurements, thus a forward step selection algorithm was used to select only those measurements that significantly contributed to the predictive power of the logistic model and the model selected between all these measurements only two variables, namely “maxillo-alveolar breadth” and “incisive foramen-basion length” were enough to provide an overall accuracy of 94% for sex prediction . laisse et al. (32) made study on hard palate and used logistic regression models for sex determination, that select incisive foramenbasion as the highest expression of sexual dimorphism with an accuracy rate of 63%. sumati et al. (2) used multiple logistic regressions in their study of hard palate for sex identification and found that the palate breadth was the best sex predictor with accuracy 66.7%. the results of the present study showed that the hard palate and in relation to skull base exhibits good anatomic variations between sexes thus all the linear measurements of the palatal bones and the skull base were used together in discriminant model to differentiate between females and males and the resulting equation was statistically significant with overall prediction accuracy 93% and wilks' lambda=0.365. in this discriminant model maxillo-alveolar breadth was the best discriminating variable then incisive foramen-basion. maria et al. (33) made study about the role of the shape and the size of the hard palate and the cranial base in sex determination and used discriminant function analysis in the study with accuracy 90.4% for cranial base, and 74.8% for palate and wilk’s lambda = 0.842 receiver operating characteristic analysis (roc) was used to evaluate the validity of various tested linear measurements in predicting male sex variation from female as it was shown. and among the computed tomographic linear measurements it was found that the size of palate was the first value with the highest validity in predicting male sex while maxillo-alveolar j bagh college dentistry vol. 28(4), december 2016 sex variations by oral diagnosis 88 index was the last value and it had no significant role in sex determination. variation in the percentage of accuracy between the two studies could be related to different race and different sample size, also craniofacial growth may be influenced by environment, nutrition and genetic factors (34). references 1. wiskott l, fellous jm, kruger n, malsburg c von der. face recognition by elastic bunch graph matching. ieee spectrum 1997; 19(7): 775-9. 2. patnaik vv, phatak a. determination of sex from hard palate by discriminate function analysis: international j basic and applied medical sciences., 2012; 2(3): 243-51. 3. iscan my, helmer rp. forensic analysis of the skull in morphologic and osteometric assessment of age, sex, and race from the skull. new york: john wiley and son's inc. publication; 1993. pp. 71-83. 4. arbenz go. medicina legal e antropologiaforens. são paulo. atheneu; 1988. (italian). 5. du brul el. sicher and du brul's oral anatomy. 8th ed. st. louis: ishiyaku euro america, inc.; 1988, p. 27-8. 6. kalmey jk, rathbun ta. sex determination by discriminant function analysis of the petrous portion of the temporal bone. j forensic sci. 1996; 41: 865-7. 7. loth sr, henneberg m. mandibular ramus flexure is a good indicator of sexual dimorphism. am j phys anthropol 1998; 105: 91-2. 8. methathrathip d, apinhasmit w, chompoopong s, lertsirithong a, ariyawatkul t, sangvichien s. anatomy of greater palatine foramen and canal and pterygopalatine fossa in thais: considerations for maxillary nerve block. surgradiol anat 2005; 27(6): 511-6. 9. teixeira cs. topography of the greater palatine foramen in macerated skulls. a master thesis, brasilia, unb; 2007. 10. tillman b, lorenz r. the stress at the human atlanto-occipital joint. anat embryol 1978; 153: 269–77. 11. holland td. sex determination of fragmentary crania by analysis of crania base. am j phys anthropol 1986; 70: 203–8. 12. terrier m, becker g. spiral ct of the abdomen. spriger; 2002, chapter 1. pp. 1-10. 13. white sc, pharaoh mj. oral radiology principles and interpretation. 6th ed. mosby; 2009. 14. fishman ek., magid d, ney dr, chaney el, pizer sm, rosenman jg, levin dn, vannier mw, kuhlman je, robertson dd. three-dimensional imaging. radiol 1991; 181(2): 321-37. 15. cavalcanti mgp, vannier mw. quantitative analysis of spiral computed tomography for craniofacial clinical applications. dentomaxillofac radiol 1998; 27: 344-50. 16. moore jansen pm, ousley sd, jantz rl. data collection procedures for forensic skeletal material 1994; 45-51. 17. francesquini júnior l, francesquini ma, de la cruz bm, pereira sdr, ambrosano gmb, barbosa cmr, daruge júnior e, del bel cury aa, daruge e. identification of sex using cranial base measurements. j forensic odonto-stomatol 2007; 25 (1): 7-11. 18. bass wm. human osteology in the skulls or cranium 4th ed. missouri archaeological society, columbia; 1995. pp. 83-85. 19. laranch sl, macintosh nwg. the craniology of the aborigines of coastal new south wales. the oceania monographs, 1966; 13: 72-3. 20. holland td. use of the cranial base in the identification of fire victims. j forensic sci 1984; 29: 1087–93. 21. krogman wm, iscan my, charles ct. the human skeleton in forensic medicine, springfield, illinois, 1986. 22. sicher h, dubrul el. anatomiabucal. 7th ed. guanabara koogan, rio dejaneiro; 1977, p. 38. 23. williams pl. gray’s anatomy. 38th ed. new york: churchill livingstone; 1995. 24. marchal g, vogl tj, heiken jp, rubin gd. multidetector-row computed tomography scanning and contrast protocols, springer-verlag, italia 2005, pp. 5–12. 25. cesarani f, martina m, ferraris a. whole-body three-dimensional multidetector ct of 13 egyptian human mummies. ajr, 2003; 180: pp. 597–606. 26. marsh jl, lo lj, vannier mw, patel vv. craniofacial computer-assisted surgical planning and simulation. clinplast surg1994; 21: 501-16. 27. kane aa, marsh jl, lo lj, vannier mw. mandibular dismorphology in unicoronal synostosis and plagiocephally without synostosis. cleft palate craniofac j 1996; 33(5): 418-23. 28. larnach sl and freedman l. sex determination of aboriginal crania from coastal new south wales, australia. records of the australian museum, 1964; 26: 295-308. 29. song hw, lin zq and jia jt. sex diagnosis of chinese skulls using multiple stepwise discriminant function analysis. forensic science international 1992; 54: 135-40. 30. burris bg, harris ef. identification of race and sex from palate dimensions. j forensic sci 1998; 43: 959–63. 31. patel m. a study of the hard palate in the skull of central indian population. international j pharma bio sci 2012; 3(2): 527. 32. nascimento l, lima c, de oliveira of, sassi c, picapedra a, et al. sex determination by linear measurements of palatal bones and skull base. j forensic odontostomatol 2012; 30 (1): 37-44. 33. chovalopoulou m, valakos ed, manolis sk. sex determination by three-dimensional geometric morphometrics of the palate and cranial base. j biol clinic anthrop stuttgart 2013; 70(4): 407–25. 34. suazo gic, zavando mda, smith rl. evaluating accuracy and precision in morphologic traits for sexual dimorphism in malnutrition human skull: a comparative study. int j morphol 2008; 26(4): 876– 83. . shorouq f.doc j bagh college dentistry vol. 25(3), september 2013 surface properties restorative dentistry 49 surface properties of heat treated with different durations of titanium alloy dental implants shorouq m. abass, b.d.s., m.sc. (1) abstract background: the surface properties of the titanium alloy plays a significant role in the bond of the dental implant with living bone and modification of the implant surface could enhance osseointegration. this study was aimed to investigate the effect of different durations of heat treatment on the surface properties of titanium alloy for dental implants. materials and methods: twenty disks of (ti-6al-4v) alloy were prepared. the sample was divided into four test groups to study the effect of different duration of heat treatment to the surface topography; surface chemistry, titanium oxide layer thickness, blood contact angle, & blood drop diameter of titanium alloy samples were investigated to evaluate the effect of different durations of heat treatment at a temperature of 750°c. results: the surface topography, surface chemistry, titanium oxide layer thickness, blood contact angle, & blood drop diameter of titanium alloy samples improved highly significantly as the duration of heat treatment increased. conclusions: the heat treatment of 750°c for 90 minutes showed the highest improvement in the surface properties which in turn will lead to enhancement in the osseointegration of the dental implant. keywords: heat treatment, titanium alloy, surface properties. (j bagh coll dentistry 2013; 25(3):49-56). introduction the surface properties of the titanium alloy plays a significant role in the structural and functional bond of the dental implant with the living bone therefore, modification of the implant surface was proposed as a method for enhancing osseointegration. surface topography, wettability, surface chemistry, and thickness of titanium oxide layer are all considered to be very critical factors that could influence osseointegration.1-4 wettability is one of the surface characteristics of an implant that may influence the speed and strength of osseointegration.5,6 measurement of the contact angle of a liquid is one way to quantify the surface free energy of solids or the ability of the liquid to wet the solid.7,8 titanium biocompatibility is due the alloy’s ability to form a surface oxide film spontaneously and immediately when subjected to oxygen. this titanium oxide layer (tio2) covers and protects the underlining metal from corrosion. the protective effect of this layer against corrosion prevents the release of toxic metal particles which can induce an osteolytic reaction that may lead to implant loosing and failure.7 this titanium oxide layer cannot meet all the clinical requirement due to its small thickness which is between 5-10 nm. this film forms spontaneously at ambient temperatures and pressure and is called native oxide. titanium oxide films can also be artificially grown by heating, acid etching and electrolytic oxidation, also known as anodizing.8 (1) lecturer at the department of prosthodontics, college of dentistry, baghdad university. in order to increase the thickness and stability of oxide layer, various strategies have been utilized to improve the mechanical and biological properties of titanium alloy and some of these strategies were the sol-gel, anodizing, and hydrothermal methods 9-15 elias et al.16 analyzed the influence of sandblasting, acid etching and anodizing on the dental implant surface and their results showed that the surface treatment lead to a change in the surface wettability. the implants with treated surfaces showed greater roughness, higher friction coefficient, lower contact angle and demanded a larger insertion torque than machined implants. these methods have disadvantages such as cost, complexity, and the time needed, while heat treatment of titanium alloy was shown to be lower in cost, easier, simple, needs less time, and with hopeful results. heat treatment of titanium alloy result in enhancement of surface roughness, surface area, oxide layer thickness, wettability, and protein and osteoblast adherence.5 lee et al.18 stated that “as the temperature of the thermal treatment increased the surface characteristics and biocompatibility of titanium increased”. they investigated the effect of three different thermal treatment temperatures (300°c, 500°c, and 750°c) for 30 minutes on the surface characteristics of commercially pure titanium. they found that the only effective thermal treatment for the commercially pure titanium was at 750°c for 30 minutes since it showed greater improvement in the surface characteristics, and cellular interactions of the tio2 layer. the hypothesis for this research was that the surface properties of the titanium alloy changed as the time of heat treatment increased at 750°c. so, this study was aimed to investigate the effect of j bagh college dentistry vol. 25(3), september 2013 surface properties restorative dentistry 50 different durations (30 minutes, 60 minutes, and 90 minutes) at the effective heat treatment temperature of 750°c on the surface topography, titanium oxide layer thickness (tio2), surface chemistry, contact angle, and diameter of blood drop of grade 5 titaniumaluminumvanadium alloy (ti-6al-4v). materials and methods titanium disk shaped samples were prepared from grade 5 titaniumaluminumvanadium alloy (ti-6al-4v) with dimensions of 6mm diameter and 1mm thickness, five samples for each test group. the sample surface was polished with silicon carbide grit paper 400 then 1200. after polishing, the sample was cleaned of any remaining particles generated during polishing. this was commenced by the use of acetone and ethanol for 10 minutes, and rinsed with deionized water between and after the application of each solvent.18 all the samples were placed in a desiccator to eliminate any moisture and for storage.17 the samples were divided into four test groups; control group (a) received no treatment, group (b) was treated with 750°c for 30 minutes, group (c) was treated with 750°c for 60 minutes, and group (d) was treated with 750°c for 90 minutes. they were heated inside a heavy duty box furnace (carbolite, parsons lane, hope, england). the heat treated samples were immediately transferred to a desiccator until testing. during handling, the samples were carefully held at the disk edges with tweezers to avoid any damage and/or contamination of the sample surfaces. scanning electron microscope (sem) to assess the oxide layer thickness, test samples were embedded in cold cure acrylic resin and then cross-sectioned.18 the surface topography and oxide layer thickness were observed by scanning electron microscopy (vega easy probe sem tm). x-ray diffraction (xrd) the surface chemical composition of the titanium samples was analyzed by the study of the x-ray diffraction patterns generated by the x-ray diffractometer (xrd-6000 shimadzu x-ray diffractometer) for the titanium alloy samples. blood contact angle measurement blood was obtained from a male donor of 21 years of age and was immediately mixed with 3.8% sodium citrate and used for the blood contact angle measurement at room temperature.19 a drop of blood of 2 μl volume was placed on the titanium disk sample with the use of an adjustable volume pipette of 0.5 – 10 μl to ensure a standard size of blood drop for all the samples. a picture was taken for the blood drop after 15, 30, 45, 60, and 75 seconds of placement on the disk sample surface. the measurement of the blood contact angle from the pictures was performed by the use of the corel draw x3 analyzing software.16, 17 diameter of blood drop a picture was taken for the blood drop on the surface of the titanium samples after 2 minutes of blood drop placement. the diameter was measured by recording the average of five different diameter measurements of the blood drop on the titanium sample surface. the measurement was carried out with the use of the software program dimaxis version 2.3.3. statistical analysis the data of the titanium oxide layer thickness, blood contact angle, and blood drop diameter for each test group was analyzed using the statistical package for social sciences (spss) version 17.0. descriptive statistics, one way analysis of variance (anova) and least significant difference (lsd) test was used to assess the significant differences at a significance level of p<.05. results surface topography the surface topography of the test groups differed from that of the control group, as shown in figure (1). the surface of the test groups tended to be rougher and more irregular. the crystallites of the surface of the test groups were larger, rougher, & more tapered in shape and this increased with the increase of time of the heat treatment. this was contrary to the surface of the sample of the control group which was smaller, smoother, & more regular. j bagh college dentistry vol. 25(3), september 2013 surface properties restorative dentistry 51 figure 1. sem images of the surface topography and morphology of the test groups a, b, c, &d from left to right respectively. thickness of titanium oxide layer the sem image of the cross sectioned samples of the test groups revealed that the greatest thickness was for group d (19.2μm) and the least was for the control group (1.6μm) (figures 2 & 3). the thickness of the titanium oxide layer increased highly significantly as the time of heat treatment increased (p<0.01)(table 1,2 & 3). figure 2. sem image of the tio2 layer thickness of groups a, b, c, & d from left to right respectively. figure 3.tio2 layer thickness (μm) for all test groups. table 1. descriptive statistics of the tio2 layer thickness (μm) for all test groups. test groups n mean s.d. a 5 1.6340 0.35956 b 5 8.9340 0.76989 c 5 12.6660 1.06263 d 5 19.2140 1.98598 j bagh college dentistry vol. 25(3), september 2013 surface properties restorative dentistry 52 table 2. oneway anova of the tio2 layer thickness for all test groups sum of squares df mean square f-test sig. between groups 808.167 3 269.389 185.936 0.000 within groups 23.181 16 1.449 total 831.349 19 table 3. multiple comparisons lsd for the tio2 layer thickness (μm) for all test groups test groups mean difference s.e. sig. ab -7.30000* 0.76127 0.000 ac -11.03200* 0.76127 0.000 ad -17.58000* 0.76127 0.000 * the mean difference is significant at the 0.05 level. xray diffraction (xrd) the xray diffraction patterns (figure 4) for the test groups when compared with the control group showed that the intensity of the xrd peaks of the test groups decreased, some peaks were eradicate, and new peaks were generated. the titanium peak was eradicated and the anatase and/or rutile phases appeared for all test groups. figure 4. xrd patterns of test groups blood contact angle the blood contact angle of all test groups (figure 5 & 6) decreased with increase in the time of heat treatment. this change was highly statistically significant for all the test groups when compared with the control group (p<0.01) (table 4,5 & 6). figure 5. blood contact angle for groups a, b, c, &d from left to right respectively. figure 6. blood contact angle for the test groups. j bagh college dentistry vol. 25(3), september 2013 surface properties restorative dentistry 53 table 4. descriptive statistics for the blood contact angle (degree). test groups n mean s.d. a 5 65.8500 5.39850 b 5 30.1000 1.75535 c 5 34.2500 1.82859 d 5 15.4000 1.40979 table 5. oneway anova test for the blood contact angle. sum of squares df mean square f-test sig. between groups 6763.075 3 2254.358 240.105 0.000 within groups 150.225 16 9.389 total 6913.300 19 table 6. lsd multiple comparisons for the blood contact angle(degree). test groups mean difference s.e. sig. ab 35.75000* 1.93794 .000 ac 31.60000* 1.93794 .000 ad 50.45000* 1.93794 .000 *the mean difference is significant at the 0.05 level. diameter of blood drop the diameter of blood drop formed on the surface of the samples of the test groups increased as the time of the heat treatment increased. the greatest diameter was for group d (3.9mm) while the smallest diameter was for the control group (2.2mm) (figure 7 & 8). statistical analysis showed a highly significant increase in the diameter of blood drop for all test groups when compared with the control group (p<0.01) (table 7,8 & 9). figure 7. diameter of blood drop for test groups a, b, c, & d from left to right respectively. figure 8. diameter of blood drop for the test groups. j bagh college dentistry vol. 25(3), september 2013 surface properties restorative dentistry 54 table 7. descriptive statistics for the diameter of blood drop (mm). test groups n mean s.d. a 5 2.2540 .09017 b 5 2.8980 .14184 c 5 3.0020 .10354 d 5 3.9340 .20107 table 8. oneway anova for the diameter of blood drop. sum of squares df mean square f-test sig. between groups 7.187 3 2.396 120.684 0.000 within groups .318 16 .020 total 7.504 19 table 9. lsd test multiple comparisons for the diameter of blood drop (mm). test groups mean difference s.e. sig. ab -.64400* .08911 0.000 ac -.74800* .08911 0.000 ad -1.68000* .08911 0.000 *the mean difference is significant at the 0.05 level. discussion the hypothesis that the surface properties of the titanium alloy enhanced as the time of heat treatment increased at 750°c temperature was accepted. all the test groups showed a change in the surface properties of the titanium alloy including the surface topography, titanium oxide thickness, surface chemistry, blood contact angle, & blood drop diameter. the differences in these changes among the test groups, increased as the time of heat treatment increased, to reach the maximum readings for the samples with surface properties treated at 750°c for 90 minutes. surface topography and morphology of heat treated titanium alloy (figure 1) revealed an increase in the surface irregularities and a change in the shape and size of the surface crystals as the time of heat treatment increased; larger, rougher, & more tapered. the temperature of transition of titanium to an anatase/rutile phase was at 750°c for 30 minutes as stated by lee et al.18 and the sample were subjected to this temperature for more than that duration of time which may explain that this transition was more for those samples subjected for a longer duration of time. this transition may explain the increased changes in the surface topography and chemical composition as the heat treatment prolonged. the irregularities in the shape and change in the size of the crystal of heat treated titanium surface was also found by both pookmanee & phanichphant 20 and ninsonti et al.21 but at different temperatures and durations than that of this research. the enhancement in the thickness of titanium oxide layer (figure 2) increased as the time of the heat treatment increased and this may be related to the enrichment of titanium matrix with oxygen, as the solubility of oxygen to the titanium matrix increased as the time of heat treatment of titanium alloy increased.22,18 this may explain the improvement in the thickness of oxide layer which increased as the time of heat treatment increased. the surface chemistry was analyzed by comparing the xray diffraction pattern of the control group with the patterns of the test groups (figure 4) and it showed a decrease in the intensity of the peaks related to the titanium alloy of the heat treated test groups and this may be related to the fact that the increase in thickness of the titanium oxide layer prevented the x-ray beam from penetrating completely to the alloy but rather was blocked partly by the oxide layer. this was confirmed by the sem image of cross section of the test samples which revealed this increase in thickness of the oxide layer (figure 2), and this was in agreement with the results of macdonald et al.23 who stated that the heat treatment produced thick titanium oxide layers on the surface of the titanium alloy. therefore the heat treated titanium alloy disk did not display a titanium or aluminum peak. new peaks were also generated in the x-ray diffraction patterns of the test groups when compared with the control group j bagh college dentistry vol. 25(3), september 2013 surface properties restorative dentistry 55 and this was a result of transition of the alloy to the anatase/rutile phase as discussed previously. this agreed with the results of lee et al.18 in which they declared the appearance of additional peaks in the xrd patterns of heat treated titanium. in this research, as the time of heat treatment of titanium alloy increased the blood contact angle decreased and the diameter of the blood drop increased to reach the best results at 750 °c for 90 minutes. this meant that there was an increase in the wettability and this is one of the vital implant surface factors that may influence osseointegration.1,4 the increase in wettability and surface energy was attributed to the anatase/rutile phase transition that occurred at high temperatures and could affect the surface topography, surface irregularities, chemical structure, and crystal structure.24, 25 thus, in turn, increased the wettability and surface energy.26 the increase in titanium oxide layer, as discussed earlier, may be one of the reasons responsible for the increase in wettability of the test sample surfaces. the oxide layer of pure titanium exhibits a high surface energy, wettability, as stated by tengvall & lundstrom 27 and thus the increase in this layer may have attributed to an increase in the wettability of the test samples. surface roughness and surface topography may also have played a role in the increase in the wettability of heat treated titanium alloy sample surfaces as was declared by macdonald et al.23, scharnweber et al.28 and rupp et al.29. they found that surface roughness of titanium was shown to have a significant influence on the wettability behavior of the titanium surfaces. this also confirms the results of this research in which the surface topography irregularities increased as the time of heat treatment increased. chemical structure changes may be another cause for the changes in the wettability of treated titanium as was confirmed by turkyilmaz 1, scharnweber et al.28, and pegueroles et al.30. this coincided with the results of this research which showed changes in the surface chemistry and was confirmed by the x-ray diffraction patterns. as a 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aliaa.doc j bagh college dentistry vol. 26(4), december 2014 quantitative assessment pedodontics, orthodontics and preventive dentistry156 quantitative assessment of mutans streptococci adhesion to coated and uncoated orthodontic archwires (in vitro study) aliaa abdul rhman al-lami, b.d.s., h.d.d. (1) iman i. al-sheakli, b.d.s., m.sc. (2) abstract background: the development of orthodontic biomaterials that attract less biofilm has been a goal for decades. adhesion and colonization of cariogenic streptococci are considered to play key roles in the development of enamel demineralization related to orthodontic materials. the aim of this study was to quantitatively evaluate the mutans streptococci adhesion to coated orthodontic archwires (epoxy and teflon) and uncoated archwires (stainless steel and nickel-titanium) with respect to incubation time in the presence and absence of saliva. material and method: six types of archwires stainless steel and nickel titanium with two type of coating (epoxy, teflon) were used in this study. twelve specimens of each archwire were incubated in sterilized unstimulated whole saliva (for the study group) and phosphate-buffered saline (for control group) for 2 hours, then incubated with suspension of mutans streptococci allowed to adhere for (5,90,180 minutes). adhesion was quantitated by a microbial culture technique by treating the archwires with adhering bacteria with trypsin and enumerating the colony forming unit (cfu) counts of bacteria recovered after cultivation by using dentocult sm kit. results: there was significant difference among the tested archwire types in each time interval with the highest bacterial adhesion on the niti archwires in the absence of saliva. in the presence of saliva, the results revealed nonsignificant difference at 5 min. while there was significant difference at 90 min and highly significant difference at 180 min. conclusion: the adherence of mutans streptococci was decreased in the presence of saliva on different archwires and the extended incubation time was significantly related to increase colony forming unit of mutans streptococci. keyword: mutans streptococcus, coated orthodontic archwires. (j bagh coll dentistry 2014; 26(4):156-162). introduction the development of orthodontic biomaterials (ob) that attract less biofilm has been a goal for decades, but is hampered by alack of knowledge of the fundamental aspects of bacterial adhesion to the different ob materials (1,2). the oral environment provides the proper conditions for the colonization of a complex microbiota (3). in a healthy oral cavity, these microorganisms coexist in a balanced state with their host. but when changes occur in the normal oral environment, the balanced flora changes and imbalance and disease may result (4). although a large number of studies have shown a shift in microbial populations in the presence of orthodontic fixed appliances, limited information is available as to which material would be less prone to adhesion of bacterial species and plaque accumulation (5,6). adhesion and colonization of cariogenic streptococci are considered to play key roles in the development of enamel demineralization related to orthodontic materials (7), because these materials in the oral cavity present a unique surface that can interact with bacteria, leading to pathogenic plaque formation for enamel demineralization (6,8). (1) master student, department of orthodontics, college of dentistry, baghdad university. (2)assistant professor, department of orthodontics, college of dentistry, baghdad university. several studies reported that the placement of fixed orthodontic appliances leads to increases in the volume and number of cariogenic streptococci in dental plaque, and the elevated levels of streptococci return to normal after removal of the appliance (9-11). most of the previous studies were concerned with mechanical aspect of component of fixed orthodontic appliances (12,13) and there is no study concerning the levels of adhesion of cariogenic streptococci to various types of orthodontic archwires to determine which material has a higher retention capacity of mutans streptococcus. the aim of this study was to quantitatively evaluate the mutans streptococci adhesion to coated orthodontic archwires (epoxy and teflon) and uncoated archwires (stainless steel and nickeltitanium) at different incubation time in the presence and absence of saliva coating. materialand methods specimen preparation six types of commercially available archwire with round sections (0.018 inches) of different materials (stainless steel and nickel titanium) with and without coating were tested as shown in (table 1). j bagh college dentistry vol. 26(4), december 2014 quantitative assessment pedodontics, orthodontics and preventive dentistry157 table 1. orthodontic archwires investigated in this study name of archwire manufacturer orthoforce s304vm stainless steel g&h wire company se niti g&h wire company stainless steel tooth coated g&h wire company orthoforce ultraesthetic g4 niti tooth coated g&h wire company dany ss coated archwire dany bmt company orthoforce ultraesthetic g4 niti –poly tooth coated g&h wire company each type of the ready-made wire was cut into 6 pieces of (20±1) mm. the suggested sample was to have 12 wire-pieces per each subgroup, making the total (216) pieces. all of the wirepieces were sterilized by autoclave at 20 minute at 121 ºc at 15 pound (14,15). isolation of mutans streptococci in vitro experiments were all carried out using pure isolate of mutans streptococci from stimulated saliva collected. a five healthy looking patients aged (14-18) years were volunteered for this purpose. saliva sample collected according to thylstrup and fejerskov (16). vortex mixer homogenized each saliva for two minutes. ten fold serial dilutions were performed by transferring 0.1 ml to 0.9 ml sterilized normal saline. from dilution 10 -2 and 10 -4 of salivary samples 0.1 ml was taken and spread in duplicate on the mitis salivaris bacitracin agar. these plates were incubated anaerobically using gas back, incubation period was for 48 hours at 37º c, and then plates were incubated aerobically for 24 hours at 37º c (17). unstimulated saliva collection saliva was collected from three volunteers a 35-year-old man of good oral health who had refrained from eating, drinking, and brushing for at least 2 hours before saliva collection. these volunteers had no initial dental caries and periodontal lesions. saliva collection was performed from 7:00 to 8:00 am to minimize the effects of diurnal variability in salivary composition according to ahn et al. and yang et al. (10,18). the ph of saliva was roughly determined by using sensitive ph paper and saliva that showed ph out of the acceptable range (6.5-7.2) was excluded from the experiments. adhesion of streptococci to orthodontic archwire twelve specimens of each type of archwire were incubated in 2 ml of uws with agitation for 2 hours at air-conditioned room (25-30 ºc). for negative control tests, the same procedure was performed with sterile phosphate-buffered saline (pbs, ph 7.2) instead of uws (10,19). the specimens were washed 3 times with phosphatebuffered saline solution. the specimens incubated in 5 ml suspension of bacteria at 107-108 /ml with agitation for (5, 90 and 180 minutes) at 37º c. afterwards, the specimens were rinsed 2 times immediately carefully with pbs to remove any non-adherent bacteria (20). culture of adhering bacteria for each experiment, after the washing with pbs, the specimens with their adhering bacteria from each tube were treated with 2 ml of 0.25% trypsin/edta for 45 minutes in aerobic conditions at 37º c , for detachment of the adherent bacteria (20). the kit of dentocult sm strip mutans (orion diagnostica) was used to detect s. mutans for in vitro diagnostic only. the method is based on the use of selective culture and growth of s. mutans on the test strip. strips were inserted in these solutions for five minutes. the bacitracin discs were placed in the selective culture vials 15 minutes before, and then strips were transferred to these vials and incubated for 48 hours at 37º c. the final step was the counting of adherent bacteria on the strips, and the number of colony-forming unit (cfu)/strip (21) (figure1). experiment in each time was made in triplicate and the average count was determined. figure 1: detection of ms on dentocult strip. j bagh college dentistry vol. 26(4), december 2014 quantitative assessment pedodontics, orthodontics and preventive dentistry158 statistical analyses data was presented in simple statistical measure of number, median, mean, standard deviation, and standard error. statistical analysis was done by using mann-whitney u tests and kruskall-wallis h test a probability value (p< 0.05) was considered to be statistically significant. results table 2 showed the number of adherent bacteria on different type of archwire in various time intervals without saliva. generally, there was significant difference among the tested archwire types in each time interval with the highest bacterial adhesion on the niti archwires. table 3 demonstrated the comparison between each two types of archwires with almost significant difference. table 4 showed the number of adherent bacteria on different type of archwire in various time intervals with saliva. the results revealed non-significant difference at 5 min. while there was significant difference at 90 min and highly significant difference at 180 min. again table 5 illustrated the comparison between each two types of archwires with mostly significant difference except the comparison between epoxy niti with teflon coated archwires and niti with epoxy archwires in 90 min. discussion patients faced difficulty in maintaining adequate oral hygiene when wearing fixed orthodontic appliances (22). the increased plaque accumulation and bacterial acid production result in enamel decalcification and even inflammation of the surrounding periodontal tissues (23, 24). orthodontic archwires play a significant role in plaque accumulation; therefore, awareness of the bacterial adhesion tendency of the new orthodontic archwire materials should be developed in order to select an archwire type that attracts less biofilm and has appropriate antibacterial properties. the finding of this study proved that all archwires coated with saliva were associated with decrease number of adherent bacteria in different duration in comparison with sample without saliva. these findings indicate that saliva is an important factor in the adhesion of mutans streptococci to orthodontic archwires. this may be explained by the formation of an early salivary pellicle result in reduction of the bacterial adhesion to the archwires (25,26) ,on the contrary with the non–saliva coated archwires (20,26-30). additionally, the presence of histatins, lyzozymes and lactoperioxidase components of the saliva, which possess exceptional antibacterial activities, may also contribute to the decreased adhesion of s. mutans to saliva treated archwires in vitro (31-33). contrary to the present findings, ahn et al. (4243) found that saliva coating did not significantly influence the adhesion of bacteria to orthodontic brackets which explained that saliva coating reduces the surface free energy of the underlying materials. the result of the present study revealed that in multiple comparisons, the highest adhesion of cariogenic streptococci on niti and epoxy coated while lowest for the stainless steel and teflon coated materials. this could be explained by a study conducted by amini et al. and d' anto et al. (34,35) which showed that roughness of niti is responsible for the increase in the count of cariogenic streptococci. a study on epoxy coated proved that the same reason (roughness of he surface) (36) is responsible for the increase in the colonization of cariogenic bacteria. studies on stainless steel wires (37,38) showed that the smoothness of the surface is responsible about the decrease of colony count of streptoccus on it. the presence of fluoridated chain in teflon coated archwires, which is responsible for its chemical and physical characteristics will explain the lowest colony count of mutans streptococci according to some studies (39-41). this study highlighted the role of the incubation time in modulating adhesion of cariogenic streptococci. the adhesion in the coated and non-coated group was increased by the extended incubation time and was the highest after three hours of incubation. these findings agreed with other studies of which found that extended incubation time increased the adhesion of cariogenic mutans streptococci (10,42,43). j bagh college dentistry vol. 26(4), december 2014 quantitative assessment pedodontics, orthodontics and preventive dentistry159 table 2: comparison no. of adherent bacteria on different type of archwire in each time without saliva duration groups descriptive statistics groups'comparison (kurskall-wallis h test) median mean s.d. s.e. x2 p-value 5min ss 7 6.67 1.53 0.88 12.25 0.032 (s) niti 17 16.67 3.51 2.03 e-ss 10 9.67 2.52 1.45 e-niti 10 9.33 2.08 1.20 t-niti 6 5.67 0.58 0.33 t-ss 7 7 2 1.15 90min. ss 65 65 5 2.89 15.76 0.008 (hs) niti 105 106.33 8.08 4.67 e-ss 85 85 5 2.89 e-niti 88 87.67 2.52 1.45 t-niti 73 74.33 3.21 1.86 t-ss 76 75.67 3.51 2.03 180min ss 127 129.00 5.29 3.06 14.88 0.011 (s) niti 170 171.33 3.21 1.86 e-ss 150 151.67 3.79 2.19 e-niti 145 148.33 8.50 4.91 t-niti 135 134.67 3.51 2.03 t-ss 130 132.67 6.43 3.71 1ss= stainless steel; 2niti= nickel-titanium; 3e-ss= epoxy coated stainless steel; 4e-niti= epoxy coated nickel-titanium; 5t-niti= teflon coated nickel-titanium; 6t-ss= teflon coated stainless steel. table 3: comparisons between each two groups using mann-whitney u test groups 5minutes p-value 90minutes p-value 180minutes p-value ss niti 0.05* 0.05* 0.05* e-ss 0.184 0.05* 0.05* e-niti 0.184 0.05* 0.05* t-niti 0.369 0.05* 0.184 t-ss 0.822 0.05* 0.275 niti e-ss 0.05* 0.05* 0.05* e-niti 0.05* 0.05* 0.05* t-niti 0.046* 0.05* 0.05* t-ss 0.05* 0.05* 0.05* e-ss e-niti 0.822 0.5 0.513 t-niti 0.046* 0.05* 0.05* t-ss 0.184 0.05* 0.05* e-niti t-niti 0.046* 0.05* 0.05* t-ss 0.184 0.05* 0.05* t-niti t-ss 0.369 0.658 0.513 j bagh college dentistry vol. 26(4), december 2014 quantitative assessment pedodontics, orthodontics and preventive dentistry160 table 4: comparison no. of adherent bacteria on different type of archwire in each time with saliva duration groups descriptive statistics groups’ comparison (kurskall-wallis h test) median mean s.d. s.e. x2 p-value 5 min. ss 5 4.67 1.53 0.88 9.64 0.086 (ns) niti 10 10.67 4.04 2.33 e-ss 4 4.33 1.53 0.88 e-niti 3 3.33 0.58 0.33 t-niti 4 3.33 1.15 0.67 t-ss 3 3 1 0.58 90 min. ss 43 42.33 3.06 1.76 13.63 0.018 (s) niti 70 70.67 6.03 3.48 e-ss 65 65 5 2.89 e-niti 68 63.33 9.87 5.70 t-niti 48 50.33 5.86 3.38 t-ss 52 52.67 3.06 1.76 180 min ss 95 93.67 5.13 2.96 16.03 0.007 (hs) niti 148 148 8 4.62 e-ss 120 120 5 2.89 e-niti 109 109.33 7.51 4.33 t-niti 89 90 2.65 1.53 t-ss 74 75.33 3.21 1.86 table 5: comparisons between each two groups using mann-whitney u test groups 90minutes p-value 180minutes p-value ss niti 0.05* 0.05* e-ss 0.05* 0.05* e-niti 0.05* 0.05* t-niti 0.05* 0.376 t-ss 0.05* 0.05* niti e-ss 0.216 0.05* e-niti 0.376 0.05* t-niti 0.05* 0.05* t-ss 0.05* 0.05* e-ss e-niti 1 0.127 t-niti 0.05* 0.05* t-ss 0.05* 0.05* e-niti t-niti 0.127 0.05* t-ss 0.184 0.05* t-niti t-ss 0.513 0.05* references 1. anusavice k. philip’s science of dental material. 10th ed. st. louis: w.b. saunders company; 1996. 2. badawia h, evansa rd, wilsonb m, readyc d, noara jh, pratten j. the effect of orthodontic bonding materials on dental plaque accumulation and composition in vitro. biomater 2003; 24: 3345-50. 3. marsh pd, martin mv, lewis mao, williams d. oral microbiology. 5th ed. elsevier health science; 2009. 4. bachrach g, faerman m, ginesin o, eini a, sol a. oral microbes in health and disease. in: rosenberg e, gophna u (eds.). beneficial microorganisms in multicellular life forms. berlin: springer heidelberg; 2011. p. 189-201. 5. anhoury p, nathanson d, hughes cv, socransky s, feres m, chou ll. microbial profile on metallic and ceramic bracket materials. angle orthod 2002; 72(4): 338-43. 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20: 79-92. 38. yu jh, wu lc, hsu jt, chang y-y, huang hh, huang hl. surface roughness and topography of four commonly used types of orthodontic archwire. j med biol eng 2011; 31(5): 367-70. 39. farronato g, maijer r, carìa mp, esposito l, alberzoni d, cacciatore g. the effect of teflon coating on the resistance to sliding of orthodontic archwires. eur j orthod 2011; 10: 1-8. 40. gyo m, nikaido t, okada k, yamauchi j, tagami j, matin k. surface response of fluorine polymerincorporated resin composites to cariogenic biofilm adherence. appl environ microbiol 2008; 74(5):142835. 41. demling a, elter c, heidenblut t, bach f-w, hahn a, schwestka-polly r, et al. reduction of biofilm on orthodontic brackets with the use of a polytetrafluoroethylene coating. eur j orthod 2010; 32:414-8. 42. ahn sj, limb bs, yang hc, chang yi. quantitative analysis of the adhesion of cariogenic streptococci to j bagh college dentistry vol. 26(4), december 2014 quantitative assessment pedodontics, orthodontics and preventive dentistry162 orthodontic metal brackets. angle orthod 2005; 75(4):666-71. 43. ahn s, lim b, lee s. surface characteristics of orthodontic adhesives and effects on streptococcal adhesion. am j orthod dentofac orthop 2010; 137(4): 489-95. j bagh college dentistry vol. 30(2), june 2018 effect of phosphate restorative dentistry 5 effect of phosphate ester addition on transverse strength and hardness of heat cured acrylic denture base material abstract background: acrylic resin denture base consider a common denture base material for its acceptable cost, aesthetic and easy processing but still has disadvantages including easy of fracture and low impact strength. material and method: the experimental group was prepared by addition of 15% phosphoric acid 2-hydroxyethyl methacrylate ester (pa2heme) with polymethyl methacrylate monomer; the experimental groups was compared with the control one. the specimens were prepared according to ada specification no. 12 with dimension 65 mm x 10 mm x2.5 mm (length x width x thickness respectively). the prepared specimens were tested by three-point flexural strength utilizing instron universal testing machine (wdw, layree technology co.), shore d hardness tester used to measure hardness test. statistical analysis used student ttest, mean and standard deviation. results: the result of pa2heme group showed high significant reduction comparing to the control group for both transverse strength and hardness test. conclusion: mixing 15% of pa2heme with 85% methyl methacrylate (mma) can reduce the mechanical properties of new modified polymethyl methacrylate (pmma) acrylic resin. keyword: phosphoric acid 2-hydroxyethyl methacrylate ester, transverse strength and hardness. (j bagh coll dentistry 2018; 30(2):5-9) introduction the pmma consider the most widely used material as denture base due to its favorable mechanical properties and its ability for modification (1) and the perfect resin material should have adequate biological response and mechanical properties. however, the mechanical properties of pmma are important for function of removable denture such as compressive strength, tensile strength, dimensional stability, hardness, transverse strength and solubility (2). addition of 15% pa2heme to the heat cure acrylic denture base significantly reduced candida albicans adhesion and porosity (3), however according to park et al., 2003, they found that modifying the pmma with methacrylic acid to produce negative charge polymer could reduce denture stomatitis but with reduction in the physical properties of material(1). the aim of this study was to evaluate the effect of phosphoric acid 2-hydroxyethyl methacrylate ester containing pmma group on following properties: transverse strength and hardness test. (1) m.sc student, department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of prosthodontics, college of dentistry, university of baghdad. materials and methods modified pmma (mpmma) polymer was prepared by addition phosphoric acid 2hydroxyethyl methacrylate ester (sigma aldrich) to methyl methacrylate monomer in 15% ratio then mixed with powder (vertex) according to manufacturer's instruction. the p/l ratio was every 50g of pmma was added to 22.7 ml of mma monomer. two groups were prepared in the present study, they were divided into group a control (vertex dental bv), group b phosphoric acid 2hydroxyethyl methacrylate ester containing group. ten rectangular shape samples were prepared for transverse and hardness test according to ansi/ada no.12, 1999 with dimension 65 mm length x 10 mm width x 2.5 mm thickness. the samples kept in distal water at 37ₒcfor 48 hours before testing to remove residual monomer. the flexural strength was measured by instron testing machine. the acrylic strip was positioned at each end of metal rollers at 50 mm distance between two ends with centrally located rod that applied the load till fracture with cross head speed 5mm/min speed. the surface hardness was obtained by using a durometer hardness tester (shore d hardness) which consider acceptable for acrylic (plastic) material. the instrument consist of a blunt indenter (0.8 mm in diameter) that locate in cylinder (1.6 mm in diameter), which connect to a digital scale graduated from zero to 100 unit. the specimens were prepared for each group a and b. five readings were measured for every specimen, zahraa saad abed karkosh b.d.s. ) 1) basima m.a. hussien b.d.s., m.sc, ph.d. (2) j bagh college dentistry vol. 30(2), june 2018 effect of phosphate restorative dentistry 6 mean of these five reading was recorded as hardness value. in statistical analysis, the mean, standard deviation and student ttest were used for each group. results the pmma and modified pmma polymers were examined by ftir to determine about the presence of oh group. the result of test showed a changes occurred in area between 28003100 cm-1 of ftir spectra of hydroxlated polymer which gave a broad band in 29503050 cm-1 as compare to the control group. in addition, the result of ftir showed for mpmma that there is no humidity in the region of 28003100 cm-1 while the humidity present in the control pmma as in figure (1) and (2). figure (1) ftir analysis for mpmm figure (2) ftir analysis for control pmma atransverse strength results means of transverse strength test for control and pa2heme containg groups are shown in figure(3). figure (3) the mean of transverse strength by groups the results in table (1) showed that the control group had higher transverse j bagh college dentistry vol. 30(2), june 2018 effect of phosphate restorative dentistry 7 strength (97.014) than experimental group (77.520) with high significant differences between them when p < 0.05. table (1) descriptive and statistical test of transverse strength between groups group number mean sd t df pvalue control 10 97.014 1.596 34.769 18 0.000 pa2heme 10 77.520 .773 b-hardness test results the results of hardness test for control and pa2heme groups are shown in table (2) and figure (4). the control group had higher hardness values than experimental group with high significant difference with p-value ≤0.001. figure (4) the mean of hardness test by groups. table (2) descriptive and statistical test of hardness test between groups. group number mean sd t df p-value control 10 101.150 1.773 8.804 18 0.000 pa2heme 10 91.560 2.953 discussion in the present study, 15% of pa2heme added to monomer then mixed with acrylic resin powder to produce a new modified pmma in order to improve both biological and mechanical properties, however this addition reduced the transverse strength and hardness. in addition, changing the material in order to improve one property may lead to deteriorates effect on other properties. the effect of this addition on mechanical properties was evaluated by measuring, transverse strength and hardness test. mixing two different types of liquid (mma and pa2heme) produced new polymer with free hydroxyl group that give a negative charge to the new structure of polymer which in turn effect on mechanical properties (4). hardness test the results of hardness test showed highly significant reduction with pvalue ≤ 0.05 of hardness test for phosphoric acid containing group with mean comparing to control group with mean, this could be due to pa2heme prevent enlargement of polymer chains, thus alter the physical characteristics of new pmma (5). furthermore, the reduction in hardness test may result from the reduction of other components of monomer like ethylene glycol dimethacrylate (egdma) which is cross-linking agent (5). j bagh college dentistry vol. 30(2), june 2018 effect of phosphate restorative dentistry 8 the reduction in hardness of pa2heme group may resulted from lengthen ester chain of mpmma that increased the flexibility of material, this agree with pavle et al., 2015 who used itaconic acid instead of methacrylic acid for its advantageous point as a natural product (7-8) and less toxic (9), however; he found as the concentration of itaconic acid increase, both stiffness and deformation of the material increase, probably this occur due to plasticization action of aliphatic chain of itaconic acid, in addition, adding a methylene unite to increase the length of ester chain could increase the flexibility of material that cause internal plasticization of material. although, water sorption and solubility were not measured in the present study, the negatively charged polymer increased water sorption and increase the hydrophilicity of material (1). there is hydrophilic radicals that could enhance water sorption and water considers complex solvent that interact with polymer because its polarity and forming hydrogen bonds that enable it to cluster and lead to plasticization of material matrix (10). transverse strength the results showed highly significant reduction in transverse strength of phosphoric acid containing group compare to control group and this probably result from the dilution of the cross-linking agent (egdma), since denture acrylic resin consist of powder (prepolymerized pmma), monomer (mma) and cross-linking agent (egdma), once polymerization reaction begin, the monomer partially dissolve in the polymer to produce a new larger molecular weight polymer with the help of cross-linking agent. the cross-linking agent add to concentration range between 5%-6% by weight, which may assist in growing the chain of polymerized polymer. however, in 1995, arima et al., found that increasing the concentration of cross-linking agent could increase the flexural strength and modulus. the results go in agreement with those obtained by gunjan et al., 2007 who found that increase the concentration of experimental phosphate compound, the flexural strength and modulus decreased. furthermore, the reduction of transverse strength of mpmma could attributed to the repulsion forces created inside the polymer which is became obvious when the polymer is subjected to mechanical tests like transverse strength or tensile test, because these repulsion internal forces could, effect on modulus of elasticity which consider the basic response of material to subjected forces, this agree with sang et al., 2009. . the addition of 15% of pa2heme could reduce the transverse strength and hardness of new pmma. however, many methods introduced to improve the mechanical properties of new pmma in cooperation of fiber like polyethylene, carbon and glass (13-16). also incooperation of fiber found to be effectively increased the transverse strength of pmma (17). although a pervious study suggest, addition of fiber may increase roughness of pmma (18). conclusion modification of pmma with pa2heme cause high significant reduction in the transverse strength and hardness of mpmma. refrences 1. park se, periathamby ar, and loza jc, 2003 “effect of surface-charged poly (methyl methacrylate) on the adhesion of candida albicans,” journal of prosthodontics; 12 (4): 249–254. 2. umemoto k and kurata s,1997. “basic study of a new denture base resin applying hydrophobie methacrylate monomer,” dental materials journal; 16 (1) : 21–30. 3. .zahraa sa karkosh, 2017. “effect of different modified heat cure denture base material on adherence of candida albicans and on some of mechanical properties at different time intervals” master thesis, baghdad university/ college of dentistry. 4. park, s e, chao m., and raj pa, 2009. mechanical properties of surface-charged poly (methyl methacrylate) as denture resins. international journal of dentistry, (6): 841431. 5. azevedo a m, regis r r., chaves c l, souza r f and fernandes r m, 2010. physical properties of a denture base acrylic resins after incorporation of anionic charges. dental materials; 19(51): 290– 294. 6. spasojevic, p, zrilic m, panic v, stamenkovic d, seslija s and velickovic s, 2015. the mechanical properties of a poly ( methyl methacrylate ) denture base material modified with dimethyl itaconate and din -butyl itaconate, international journal of polymer sciences;2015: 9. 7. kobayashi t,1978, “production of itaconic acid from wood waste,” process biochemistry, 1978; 5 (15): 22. 8. riscaldati e, moresi m, federici f, and petruccioli m, 2000. “effect of ph and stirring rate on itaconate production by aspergillus terreus,” journal of biotechnology; 83 (3): 219–230. 9. japan chemical industry ecology (jcie) toxicology and information center, sids initial assesment profile cas 2001; (97):65-4. j bagh college dentistry vol. 30(2), june 2018 effect of phosphate restorative dentistry 9 10. schult ka, paul dr, 1996. techniques for measurement of water vapor sorption and permeation in polymer films. j appl polym sci;61(11):1865–76 11. arima t, hamada t, mccabe jf, 1995. the effects of cross-linking agents on some properties of hemabased resins. j dent res; 74:1597–1601. 12. gunjan dhir , david w berzins , virendra b dhuru , raj a periathamby and andrew dentino, 2007. “physical properties of denture base resins potentially resistant to candida adhesion”, j prosthodont; 16 (6): 465-472. 13. bowman a j and manley t r, 1984. “the elimination of breakages in upper dentures by reinforcement with carbon fibre,” british dental journal; 156 (3): 87–89. 14. rodford r, 1986. “the development of high impact strength denture-base materials,” journal of dentistry, 14 (5):214–217. 15. ladizesky n h, ho c f, and chow t w, 1992. “reinforcement of complete denture bases with continuous high performance polyethylene fibers,” the journal of prostheticdentistry, 68 (6): 934–939. 16. vallittu p k, 1996. “a review of fiber-reinforced denture base resins,” journal of prosthodontics, 5 (4): 270–276. 17. john j, gangadhar s a, and shah i, 2001 "flexural strength of heat-polymerized polymethyl methacrylate denture resin reinforced with glass, aramid, or nylon fibers,” the journal of prosthetic dentistry; 86 (4):424-427. 18. waltimo t, tanner j, vallittu p, and haapasalo m, 1999. “adherence of candida albicans to the surface of polymethylmethacrylate-e glass fiber composite used in dentures,” international journal of prosthodontics, 12 (1):83–86. الخالصة و سهولة الكسر قاعدة األسنان تعتبرواسعة االستخدام بسبب تكلفتها مقبولة، الجمالية ,قابلة للمعالجة ولكن ال يزال لديه عيوب بما في ذلك لاالكريليك الراتنج الخلفية: .قوة التأثير هيدروكسي إيثيل ميثاكريالت استر مع مونومر ميثاكريالت متعدد -2حمض الفوسفوريك ٪11تم تحضير المجموعة التجريبية بإضافة المواد وطرق البحث: ر السماكة على التوالي(. تم إعداد العينات الختبا× العرض × مم )الطول 2.1× مم 11× مم 51مع البعد adaالميثيل. تم تحضير العينات طبقا للمواصفة رقم اختبار صالبة تستخدم لقياس اختبار صالبة. dثالث نقاط اختبار قوة الثني باستخدام إنسترون العالمي اختبار آلة ، شور قوة عرضية واختبار صالبة مقارنة مع مجموعة السيطرة.ل نسبة قليلة قد سجلت pa2hemeأن مجموعة النتائج: لكن مع تقليل الصفات الميكانيكيمن المونيمر قد قللت جدا نسبة التصاق الفطريات لمادة الرانتج و %51مع pa2hemeمن %11ان خلط االستنتاج: rand f.doc j bagh college dentistry vol. 25(2), june 2013 sonographic assessment oral diagnosis 94 sonographic assessment of normal cervical lymph nodes in a sample of syrian population rand sh. al-ani, b.d.s., m.sc. (1) ammar m. mashlah, b.d.s., m.sc., ph.d. (2) mohammad iyad al-hafar, b.d.s., m.sc., ph.d. (3) abstract background: sonographic examination is an important tool in assessment of normal and abnormal cervical lymph nodes. the aim of the study is to assess the distribution and the characteristic features of normal cervical lymph nodes in a sample of syrian population. materials and methods: fifty healthy syrian subjects (25 men and 25 women) with an age of 20 -60years old, who had their cervical lymph nodes examined by ultrasound. three hundred and two lymph nodes were detected. lymph nodes were evaluated for their number, size, site, echogenic hilus, shape, as well as for the border sharpness. the subjects were categorized by age into four groups, (20 -30, 31 40 , 41 50 , 5160 years ). statistical analysis of data was done using spss software (version 11.5), and analytical one way analysis of variance (anova), duncan’s multiple range test. results: the results showed that there was no significant difference in mean number of nodes between different age groups. all lymph nodes were hypoechoic; majority of them possessed an echogenic hilus, with transverse diameter of 8 mm or less. all lymph nodes were oval except for submandibular and parotid nodes which appeared round. conclusions: this study provides a sonographic appearance of normal cervical lymph nodes in relation to their site, size, shape, numbers, border sharpness, and echogenic hilum, in a sample of syrian population. key words: gray scale sonography, cervical lymph node, syrian population. (j bagh coll dentistry 2013; 25(2):94100). الخالصة توزیع وخصائص العقد اللمفاویة تقییم : الھدف من البحث. یعتبر الفحص باألمواج فوق الصوتیة من األدوات المھمة لتقییم العقد اللمفاویة العنقیة السلیمة وغیر السلیمة:.البحث خلفیة . العنقیة السلیمة لدى عینة من المجتمع السوري سنة، باستخدام جھاز األمواج فوق الصوتیة، تم الكشف عن 60-20بعمر ) أنثى 25ذكرا و 25(تم فحص العقد اللمفاویة العنقیة السلیمة لخمسین فردا سوریا : مواد وطرائق البحث 30،31-20(ُقسمت أفراد العینة إلى الفئات العمریة التالیة . یمت ھذه العقد من ناحیة العدد،والحجم،والموقع، ووجود السرة، والشكل، فضال عن وضوح الحافاتعقدة لمفاویة، ُق 302 .duncan's multiple range ,(anova)، واختبارات spss(version 11.5)تم انجاز التحلیل اإلحصائي باستخدام برنامج ). سنة 50،51-6040،41 جمیع العقد .ملیمتر 8≤ ستعرض أظھرت النتائج عدم وجود اختالفات معنویة بین الفئات العمریة ، جمیع العقد اللمفاویة منخفضة الصدى،ومعظمھا تحتوي على سرة ،وبقطر م:النتائج ).0.5≥القطر الطولي /نسبة القطر المستعرض(تحت الفك األسفل والنكفیة كانت دائریة الشكل ،باستثناء العقد اللمفاویة )0.5<القطر الطولي/نسبة القطر المستعرض(بیضویة الشكل ل، والعدد، ووضوح الحافات، ھذه الدراسة أوضحت مظاھر العقد اللمفاویة العنقیة السلیمة في الفحص باألمواج فوق الصوتیة بما یتعلق بموقع العقد ، والحجم ، والشك: االستنتاج .رة لدى عینة من المجتمع السوري ووجود الس . األمواج فوق الصوتیة،العقد اللمفاویة الرقبیة، المجتمع السوري :كلمات مفتاحیھ introduction ultrasound (us) is a useful imaging modality in the evaluation of cervical lymphadenopathy (1,2). gray-scale sonography is widely used in evaluation of the number, size, site, shape, borders, matting, adjacent soft-tissue edema, and internal architectures of cervical lymph nodes (3,4). ultrasonography allows the evaluation of not only lymph nodes that are 10 mm in diameter or more, which are generally diagnosed as cervical lymph node metastasis-positive by computed tomography (ct) or magnetic resonance imaging (mri), but also lymph nodes of less than 10 mm diameter, based on sufficient image information (5). although ct and mri are used to evaluate cervical lymph nodes, the nature and internal architecture of small lymph nodes (<5 mm) may not be readily assessed (6). (1) phd. student. department of oral medicine, dentistry college, damascus university. (2) professor. department of oral medicine, dentistry college, damascus university. (3) assistant. professor. department of oral medicine, dentistry college, damascus university. the inaccuracy of clinical palpation paved the way for further studies in search of other more accurate diagnostic means for detecting neck nodes. debate persists over the relative merits of imaging in the evaluation of the neck for metastatic disease. imaging techniques like ct and mri have been popularized to detect metastatic neck nodes (7). many previous researches have usually studied pathologic nodes, and few studies have examined normal cervical lymph nodes (8-10) and these were predominantly in caucasians. to our knowledge, the distributions of normal cervical lymph nodes in a sample of syrian population have not been described previously. a clear understanding of the distribution and sonographic appearances of normal cervical lymph nodes is necessary in differentiating normal from abnormal nodes. the purpose of this study was to assess the sonographic features of normal cervical lymph nodes in different regions of the neck, in a sample of syrian population. j bagh college dentistry vol. 25(2), june 2013 sonographic assessment oral diagnosis 95 materials and methods fifty healthy syrian subjects (25 men and 25 women) with no history of neck surgery, glandular fever, chronic tonsillitis, tuberculosis, head and neck malignancy, or lymphomas, were included in the study. the age for the subjects was 20-60 years, average age: 40 years. all the scans were performed with convex scanner/convex/linear ultrasonic scanner (hs4000 honda electronic co., ltd-japan) and 10 mhz linear-array transducer. the subjects lay supine on the couch with the shoulders supported by a pillow. the neck was hyper extended. since the shape of the nodes depends on the scan plane, scans were obtained with the transducer placed transversely and longitudinally until the plane showed the maximum cross-sectional area of the lymph node. eight regions in the neck were delineated as described by hajek et al. (11): (1) submental ,(2) submandibular, (3) parotid , (4) upper cervical, above the hyoid bone and along the common carotid artery ( cca ) and internal jugular vein ( ijv ), (5) middle cervical, between the hyoid bone and the cricoid cartilage and along the cca and ijv, (6) lower cervical, below the cricoid cartilage and along the cca and ijv, (7) supraclavicular fossa , and (8) posterior triangle (also known as accessory chain),as shown in figure 1. all lymph nodes were divided into left and right site, except the submental nodes, which are located in the midline. all detected lymph nodes were assessed for their site, size, numbers, shape (short-to-long-axis [s/l] ratio), and border sharpness , as well as for the presence of an echogenic hilum. the parameters which were considered in this study and their definition are as follows: 1. distribution: the cervical lymph nodes were categorized into eight regions or levels on the basis of their location in the neck (11). 2. mean long axis (l), which is the largest dimension of the lymph node. 3. mean short axis (s), which is the greatest dimension perpendicular to (l). 4. shape index (s/l): the ratio of s and l. the nodes were divided into 2 groups as s/l < 0.5 indicates a long or oval node, whereas s/l ≥0.5 indicates a rounded node. 5. echotexture and homogenicity: lymph nodes were divided as hypoechoic, isoechoic, or hyperechoic to surrounding muscles (12). 6. echogenic hilus: the major vascular hilus appears as a hyperechoic linear structure within a lymph node and is continuous with the surrounding connective tissue (13) as shown in figure 2. 7. the nodal border was assessed for its sharpness, which determined by the smoothness of the margin between the lymph node and the surrounding tissue; this border is either well-defined/ sharp border or ill-defined/ unsharp border (9). the maximum transverse diameter of each node was used to determine mean nodal size. the shape of a lymph node, as visualized on sonography, varies by scan plane, so the short and long axis of the lymph nodes were measured in the plane that showed the maximum crosssectional area .the subjects were categorized by age into groups, ( 20 -30 years, 31 40 years, 41 50 years, 51-60 years). statistical analysis of data was done using spss software (version 11.5), include descriptive (frequency, percentage, mean, standard deviation),and analytical one way analysis of variance (anova), followed by duncan's multiple range test . difference was considered as significant when p < 0.05. results in 50 subjects, 302 lymph nodes were detected. all subjects had bilateral lymph nodes. the smallest node detected in this study measured 2.0 mm x 4.5 mm , and the largest node measured 8.3 ×19.9 mm . there were 162 nodes in the 25 male subjects and 140 nodes in the 25 female subjects. the mean number of lymph nodes in male subjects (6.48 nodes) is higher than that in female subjects (5.60 nodes). when the subjects were classified into five different age groups (20 -30 , 31 40 , 41 50 , 51-60 years), no significant difference was found in mean number of nodes between different age groups, as shown in tables 1,2,3. the number, shape, border sharpness, short axis, and long axis of the lymph nodes in different regions of the neck are shown in table 4. majority of lymph nodes detected in this study (98.8%) had a transverse diameter of 8 mm or less as shown in figure 3. evaluation of lymph node size based on short axis were less than 5mm as shown in figure 4 , while evaluation of lymph node size based on long axis shows that , the majority of nodes in the cervical chain, and posterior triangle were larger than 8 mm as in figure 5. the optimum cut-off value of the s/l ratio was determined in different regions of the neck: submental (0.43), submandibular (0.61), parotid (0.58), upper cervical (0.42), middle cervical j bagh college dentistry vol. 25(2), june 2013 sonographic assessment oral diagnosis 96 (0.36), lower cervical(0.31), supraclavicular(0.41) and posterior triangle (0.42),as shown in figure 6. discussion this study was done in department of oral medicine, dentistry college, damascus university. normal superficial lymph nodes are not palpable and, quite often, they are not seen with us. inflammatory or reactive nodes may become apparent on us, still being impalpable. palpable and visible nodes may be benign or malignant (14,15) . all subjects in this study had at least five lymph nodes detected , and there is no age and gender difference in the average number of normal cervical nodes, this results agree with ying et al (10) and ying et al (15). the normal lymph nodes that were detected in the present study were the submandibular (region 2), 41.3%, parotid (region 3) 25.8%, upper cervical (region4) 13.2%, submental (region 1) 5.6%, middle cervical (region 5) 4.3%, supraclavical (region 7) 3.9%, posterior triangle (region 8) 3.9%, and lower cervical (region 6) 1.6%.the distribution of the nodes are almost similar to previous studies (9,15). as multiple lymph node involvement is common in lymphoma and metastasis, the solitariness of lymph nodes may be useful in diagnosis (16). all lymph nodes found in submental, middle cervical, lower cervical, supraclavicular, and posterior regions are solitary 100% , while submandibular region shows 82.35% (solitary), 13.73% (paired), 3.92% (multiple), the parotid region 98.68% (solitary), 1.32% (multiple), and the upper cervical region 67.44% (solitary), 2.56% (paired). this result is in agreement with ying et al (9) and ying et al (15) ,except in posterior triangle lymph nodes which appear multiple in their study, they suggested that, since multiple lymph nodes are common in posterior triangle, multiplicity of lymph nodes alone is not useful for diagnosis in this region, and other features need to be elicited. the echogenicity of normal lymph nodes varies between hypoechoic and isoechoic in comparison to the surrounding fatty tissue. both reactive and malignant lymph nodes are hypoechoic compared to neighboring strap muscles. lymphomatous, tuberculous and lymphadenitis nodes are also hypoechoic; therefore hypoechogenicity is not a useful diagnostic sign (3,4). in the eight regions studied, all lymph nodes (100%) are hypoechoic. the normal parenchyma exhibits homogeneous and low echogenicity because of the predominance of a homogeneous cell population of lymphocytes without much tissue interface (17). majority of lymph nodes detected in this study (98.8%) had a transverse diameter of 8 mm or less as shown in figure 3,4, this result is in agreement with ying et al (15), who investigated that most nodes in white and chinese subjects had a maximum transverse diameter of 8 mm or less (96% and 98%, respectively), and in agreement with other studies (8,9) , which shows that (95%) of the nodes had a maximum transverse diameter of 8 mm or less. evaluation of size based on long axis of the nodes shows that, the majority of nodes in the cervical chain, and posterior triangle were larger than 8 mm as in figure 5. this is also similar to the finding of bruneton et al (8), who stated that cervical nodes except submental and submaxillary groups usually demonstrate a larger longitudinal diameter and a shorter transverse diameter. shape has been stated to be a useful criterion in differentiating normal or reactive nodes from malignant nodes. an oval node (s/l ratio < 0.5) indicates normal or reactive node, whereas malignant nodes tend to be round (s/l ratio ≥ 0.5) (3,18). lymph nodes that were detected in this study were oval in shape (s/l ratio < 0.5) , with the exception of submandibular and parotid nodes which appeared round ( s/l ratio ≥ 0.5) ,similar to the results of ying et al (9),ying et al (15) and ying and ahuja (19). although pathologic nodes are usually round, normal submandibular and parotid nodes can also be round in shape (95% and 59% respectively) (9) .this may be due to inflammation in the oral cavity which predisposes to the development of reactive hyperplasia in these lymph nodes ,leading to proliferation of lymphocytes within the lymphoid follicles, and cortical widening occurs in every region of the lymph node, and their shape becomes ovoid to round (20) .therefore, shape of lymph nodes cannot be the sole criterion in the diagnosis . normal and reactive nodes present a central echogenic hilum that interrupts the continuity of the cortical and is continued with the perinodal fat tissue. this appearance is due to the abutment of multiple medullar sinuses acting as interfaces (3, 4, 21) . it has been shown that about 90% of benign cervical nodes with a diameter above 5mm display an echogenic hilum (4) .this study shows that 89.53% of detected nodes possessed an echogenic hilus, while 10.47% of nodes do not show echogenic hilus. nodes without echogenic hilus have a transverse axis less than 3mm (small lymph nodes). this result is in agreement with j bagh college dentistry vol. 25(2), june 2013 sonographic assessment oral diagnosis 97 ying et al (22), who stated that echogenic hilus is a normal sonographic feature of most of the normal cervical lymph nodes (86%) , and small lymph nodes may not show echogenic hilus. this study showed that normal lymph nodes in the upper neck (submental, submandibular , parotid , and upper cervical regions) usually have illdefind borders (88.24% , 81.6% , 94.9% , 72.5% respectively), whereas lymph nodes in middle cervical (92.3%) , lower cervical (80%) , supraclavicular (91.6%) , and posterior region(83.3%) predominantly have well defined borders, which is in agreement with ying et al (22) .the high frequency of unsharp borders of submental , submandibular , and parotid nodes may be due to poor transducer contact, as these nodes are under the ramus of the mandible , and may also be related to the deposition of fat within the nodes . thus , nodes with sharp borders are seen predominantly in lower neck and posterior triangle , whereas unsharp nodes are common in the upper neck (23). as the longitudinal diameter of the nodes is an unreliable criterion in the differential diagnosis of cervical nodes (24), only the maximum transverse diameter of each node was used to determine mean nodal size. when combining size and shape and using 5 mm, 8 mm, and 1 cm as cut-off point in short axis, this study shows that, with 5 mm as cut-off point 57.2% fulfilled both criteria for normality, with 8 mm as cutoff point 49.1% fulfilled both criteria, and with i cm as cut-off point 48.3% fulfilled both criteria for normality . therefore, we suggested that, nodal size (short axis) greater than 10 mm combined with an s/l ratio greater than 0.5 may be useful to identify pathologic nodes. similar findings also have been reported by sugama and kitamura (25), who showed that lymph nodes with a transverse diameter of 10 rnm and an s/l ratio greater than 0.5 were likely to be metastatic. the optimum cut-off value of the s/l ratio was determined in different regions of the neck: submental (0.43), submandibular (0.61), parotid (0.58), upper cervical (0.42), middle cervical (0.36), lower cervical(0.31), supraclavicular(0.41) and posterior triangle (0.42), this result is almost similar to ying et al (26), they concluded that the optimum cut-off value in different regions of the neck was: submental (0.5), submandibular (0.7), parotid (0.5), upper cervical (0.4), middle cervical (0.3) and posterior triangle (0.4). this study evaluates the distribution and the characteristic features of normal cervical lymph nodes in a sample of syrian population. normal cervical nodes are found in eight regions of all subjects, particularly in the submandibular, parotid, and upper cervical regions. all nodes are hypoechoic. the majority of nodes demonstrate an echogenic hilus, and with a maximum transverse diameter ≤ 8 mm. the shapes of nodes are oval except the submandibular and parotid regions are round. normal lymph nodes in the upper neck have illdefind borders, while lymph nodes in middle cervical, lower cervical, supraclavicular and posterior regions have well defined borders. the s/l ratio in all regions ≤ 0.5 except the submandibular and parotid regions, as these nodes normally have an s/ l ratio greater than 0.5. references 1. haberal i, celik h, göçmen h, akmansu h, yörük m, ozeri c. which is important in the evaluation of metastatic lymph nodes in head and neck cancer: palpation, ultrasonography, or computed tomography. otolaryngol head neck surg 2004; 130: 197-201. 2. esen g. ultrasound of superficial lymph nodes. eur j radiol 2006; 58: 345-59. 3. ahuja a, ying m. sonographic evaluation of cervical lymph nodes. am j roentgenol 2005; 184:1691-1699. 4. ahuja a , ying m , ho sy, antonio g, lee yp, king ad, wong kt. ultrasound of malignant cervical lymph nodes. cancer imaging 2008; 8(1): 48–56. 5. nibu k, inoue h, kawabata k, ebihara y, onitsuka t, fujii t, saikawa m. quality of life after neck dissection. jama otolaryngol head neck surg 2005; 31(3): 391-395. 6. ahuja a, ying m. an overview of neck node sonography. invest radiol 2002; 37: 333. 7. sureshkannan p, vijayprabhu, john r. role of ultrasound in detection of metastatic neck nodes in patients with oral cancer. indian journal of dental research 2011; 22(3): 419-423. 8. bruneton jn, balu-maestro c, marcy py, melia p, mourou my. very high frequency (13 mhz) ultrasonographic examination of the normal neck: detection of normal lymph nodes and thyroid nodules. j ultrasound med 1994; 13: 87 . 9. ying m, ahuja a, brook f, brown b , metreweli c .sonographic appearance and distribution of normal cervical lymph nodes in a chinese population . j ultrasound med 1996; 15:431-436 10. ying m, ahuja a, brook f. sonographic appearances of cervical lymph nodes: variations by age and sex. journal of clinical ultrasound 2002; 30(1): 1–11. 11. hajek pc, salomonowitz e, turk r, tscholakoff d, kumpan w, czembirek h. lymph nodes of the neck: evaluation with us. radiology 1986; 158:739. 12. gupta a, rahman k, shahid m, kumar a, qaseem sm, hassan sa, siddiqui fa. sonographic assessment of cervical lymphadenopathy: role of high-resolution and color doppler imaging. head & neck 2011; 33: 297–302. j bagh college dentistry vol. 25(2), june 2013 sonographic assessment oral diagnosis 98 13. evans rm, ahuja a, metreweli c. the linear echogenic hilus in cervical lymphadenopathy a sign of benignity or malignancy? clin radiol 1993; 47: 262. 14. ahuja a, ying m, king a, yuen hy. lymph node hilus: gray scale and power doppler sonography of cervical nodes. j ultrasound med 2001;20:987-992. 15. ying m, ahuja a, brook f, metreweli c. vascularity and grey-scale sonographic features of normal cervical lymph nodes: variations with nodal size. clin radiol 2001; 56: 416-419. 16. solbiati l, cioffi v, ballarati e. ultrasonography of the neck. radiol clin north am 1992; 30:941. 17. ariji y, kimura y, hayashi n, onitsuka t, yonetsu k, hayashi k, ariji e, kobayashi t, nakamura t.power doppler sonography of cervical lymph nodes in patients with head and neck cancer. am j neuroradiol 1998; 19: 303–307. 18. khanna r, sharma ad, khanna s, kumar m, shukla rc.usefulness of ultrasonography for the evaluation of cervical lymphadenopathy. world j surg oncol 2011; 9: 29. 19. ying m, ahuja a. sonography of neck lymph nodes. i. normal lymph nodes. clin radiol 2003; 58:351 – 358. 20. gritzmann n. sonography of the neck: current potentials and limitations. j ultrasound med 2005; 26:185-196. 21. ahuja a, ying m. sonography of neck lymph nodes. part ii: abnormal lymph nodes. clin radiol 2003; 58: 359-366. 22. ying m, ahuja a, brook f, metreweli c. vascularity and grayscale sonographic features of normal cervical lymph nodes: variations with nodal size. clin radiol 2001; 56: 416-9. 23. shozushima m, suzuki m, nakasirna t, yanagisawa y, sakamaki k, takeda y: ultrasound diagnosis of lymph node metastasis in head and neck cancer. dentomaxillofac radiol 1990; 19(4):165-170. 24. chikui t, yonetsu k, nakamura t. multivariate analysis of sonographic findings on metastatic cervical lymph nodes: contribution of blood flow features revealed by power doppler sonography in predicting metastasis. am j neuroradiol 2000; 21: 561–567. 25. sugama y, kitamura s. ultrasonographic evaluation of neck and supraclavicular lymph nodes metastasized from lung cancer. intern med 1992; 31: 160. 26. ying m, ahuja a, brook f, brown b, metreweli c. nodal shape (s/l) and its combination with size for assessment of cervical lymphadenopathy: which cutoff should be used? ultrasound med biol 1999; 25(8):1169-75. figure 1: radiological classification of cervical lymph nodes (11) figure 2: gray-scale sonograph of a. upper cervical lymph node. b. submandibular lymph node. in a healthy 56-years old man, which appear hypoechoic and oval, with echogenic hilus (arrows). a b j bagh college dentistry vol. 25(2), june 2013 sonographic assessment oral diagnosis 99 table 1: descriptive statistics of lymph nodes number and age groups age group no. mean + sd 20–30 14 5.50 2.175 31–40 9 6.89 3.296 41–50 10 4.90 2.514 51–60 17 6.71 4.283 sd: standard deviation table 2: anova test shows mean number of lymph nodes between different age groups ss df ms f–value p–value between groups 31.102 3 10.367 0.956 0.422 within groups 498.818 46 10.844 total 529.920 49 p-value> 0.05: not significant table 3: duncan's multiple range test shows mean number of lymph nodes between different age groups age group no. mean + sd duncan's grouping 20–30 14 5.50 2.175 a 31–40 9 6.89 3.296 a 41–50 10 4.90 2.514 a 51–60 17 6.71 4.283 a sd: standard deviation table 4: features of the lymph nodes in different regions of the neck features of nodes regions of the neck 1 2 3 4 5 6 7 8 number 1 node 100% 82.35% 98.68% 97.44% 100% 100% 100% 100% 2 nodes 0% 13.73% 0% 2.56% 0% 0% 0% 0% > 3 nodes 0% 3.92% 1.32% 0% 0% 0% 0% 0% shape s/l < 0.5 88.2% 28.8% 25.6% 90% 100% 100% 83.3% 91.7% s/l > 0.5 11.8% 71.2% 74.4% 10% 0% 0% 16.7% 8.3% nodal border well–defined 11.76% 18.4% 5.1% 27.5% 92.3% 80% 91.6% 83.3% ill–defined 88.24% 81.6% 94.9% 72.5% 7.7% 20% 8.4% 16.7% short axis < 5 mm 94.1% 52.0% 87.2% 87.5% 84.6% 100% 100% 91.7% 5–8 mm 5.9% 42.4% 11.5% 10.0% 15.4% 0% 0% 8.3% > 8 mm 0% 5.6% 1.3% 2.5% 0% 0% 0% 0% long axis < 5 mm 0% 8.0% 21.8% 7.5% 15.4% 0% 0% 8.3% 5–8 mm 70.6% 37.6% 56.4% 40.0% 7.7% 60% 91.7% 16.7% > 8 mm 29.4% 54.4% 21.8% 52.5% 76.9% 40% 8.3% 75.0% echogenic hilus present absent 82.7% 98.9% 72.4% 100% 100% 98.1% 80.3% 83.8% 17.3% 1.1% 27.6% 0% 0% 1.9% 19.7% 16.2% j bagh college dentistry vol. 25(2), june 2013 sonographic assessment oral diagnosis 100 r:region figure 3: percentage of lymph nodes with short axis of ≤ 8. r:region. s:short axis. figure 4 : percentage of lymph nodes size in relation to short axis r:region. l:long axis. figure 5 : percentage of lymph nodes size in relation to long axis r:region figure 6: the optimum cut-off value of the s/l ratio in different regions of the neck. nabeel.doc j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 63 the effect of incorporation of prepared ag-zn zeolite on some properties of heat polymerized acrylic denture base materials zainab a. azeez, b.d.s. (1) nabeel a.fatah, b.d.s., m.sc. (2) abstract background: poly (methylmethacrylate) is the most widely used material in denture fabrication. the characteristics of acrylic resin which support microorganism development can threaten the oral health of denture users. this study was assigned to prepareand incorporate ag-zn zeolite powder into heat cured denture base material as antimicrobial material and to investigate its effect on some properties of heat cured acrylic denture base materials. materials and methods: sliver –zinc zeolite was prepared by ion exchange method and characterized then incorporated into poly (methylmethacrylate) powder in0.5% by weight. specimens were constructed and divided into 6 groups according to the using tests; each group was subdivided into 2 groups. the tests conducted in this study were: impact strength test, transverse strength test, surface hardness test, surface roughness test, water sorption test, water solubility test and color change measurement after addition. the results were statistically analyzed by t-test at p value≤ 0.05. results: characterization methods results showed the incorporation of sliver and zinc ion without change of zeolite structure framework. a non-significant effect resulted from the addition of 0.5% sliver –zinc zeolite on the impact strength, transverse strength, surface hardness, surface roughness and cause no change in color of heat cure denture base. also a highly significant decrease in water sorption and a significant increase of water solubility were observed. conclusion: preparation of sliver-zinc zeolite could be performed successfully and the addition of 0.5% of antimicrobial sliver-zinc zeolite into heat cure acrylic had a non significant effect on the impact strength, transverse strength, surface hardness, surface roughness and did not change the color, also there was a significant decrease in water sorption and increase in water solubility of acrylic resin. key words: denture stomatitis, antimicrobial agent, agzn zeolite. (j bagh coll dentistry 2015; 27(1):63-69). introduction it is well-known that removable denture bases fabricated from heat-polymerized acrylic resins may act as a reservoir for microorganisms and contribute to re-infection in denture wearers. biofilm deposition on the surface of acrylic denture bases is enhanced by the characteristics of the material, especially its porosity, irregularity and absorption (1). systemic or local antimicrobial agents have been prescribed for eliminating the fungal population; however with microbial resistance, bad healthcare and cost, research on antimicrobial denture base materials is needed for its prevention and care (2).the mechanism of zeolite’s antimicrobial effect is based upon ion exchange reaction of the antimicrobial cations within which are present zeolite pores (3). it has been reported that silver ion exchanged zeolites have good antibacterial activity and therefore have a potential in the medical field to enhance antimicrobial properties of polymers (4). since zeolite is a natural mineral, non-toxic, non-carcinogenic and has a high importance as food supplement and medical treatment agent for both humans and animals, it is completely safe to be used in medical devices (5). (1) master student. department of prosthodontics, college of dentistry, university of baghdad. (2) professor, department of prosthodontics, college of dentistry, university of baghdad. it is important to evaluate the mechanical properties of acrylic resins containing zeolites because removable and complete dentures are subjected to repeated forces (6). nevertheless, the addition of small percentages of zeolite to poly (methylmethacrylate) may be effective against microorganisms; therefore its effect on mechanical properties may be less significant than the potential benefits, especially for patients who do not follow an adequate denture cleaning protocol (7). materials and methods ag-zn zeolite can beprepared by ion-exchange method in water phase (8,9) ion-exchange is obtained by contacting a 200g of zeolite type 13x with aqueous solution containing 10 g of sliver acetate and 100 g of zinc acetate; put it in a thermostat shaker with 80 rpm at 25°c for two hours. then the ag-zn zeolite rods were ground by planter ball mill and further characterized by atomic absorption spectroscopy (aas), infrared spectroscopy and x-ray powder diffraction. one hundred twenty acrylic specimens were prepared in this study using three different metal patterns which constructed by cutting stainless steel plates into desired shapes and dimensions using turning machine these patterns were used in the mold preparation by conventional flasking j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 64 technique using heat cure acrylic resin (super acryl ®plus).the samples were divided into six groups according to the using tests and each group subdivided into two subgroups. the required weight of polymer powder and ag-zn zeolite was weighed using digital electronic balance for both groups. ag-zinc zeolite powder was added to polymer powder and mixed manually using mortar and pestle. mechanical and physical tests: impactstrength test: the specimens were prepared with dimension (80mm ×10 mm× 4mm±0.2mm) (10) for unnotched specimens. specimens were stored in distilled water at 37°c for 48 hour before the test (11). the impact strength test was evaluated following the procedure recommended by the iso 179 with charpy type impact testing device. the specimens were supported horizontally at each end and struck by free swinging pendulum of 2 joules released from fixed height in the middle. the scale reading gives the impact energy in joules that absorbed to fracture the specimen when struck by a sudden blow. the charpy impact strength of unnotched specimens were calculated in kilo joules per square meter by the following equation: a impact strength = --------x 103 (kj/m2) x.y a : the impact energyabsorbedin joules x : is the width of the specimens in millimeters y : is the depth of the specimens in millimeters.(10) transverse strength test specimens were prepared with dimension (65mm×10±0.03mm×2.5±0.03mm) according to (11) specimens were stored in distilled water at 37°c for 48 hour before the test (11). the test was performed using instron testing machine ,each specimen was positioned on bending fixture, consisting of 2 parallel supports (50)mm apart , the full scale load was 50 kg, and the load was applied with cross head speed of 1mm/min by rod placed centrally between the supports making the deflection until the fracture occurred. the transverse strength was calculated using the following formula: s = ______________ s= transverse strength (n/ mm2) p= maximum force exerted on specimens (n) l=the supporting width in mm=50 b= width of the samples (mm) d= depth of the samples (mm) (12) surface roughness tests: specimens with dimension of (65 mm×10 mm×2.5 mm)were prepared all specimens were immersed in distilled water at 37°c for 48 hours before being tested (11). the profilometer device (surface roughness tester) was used to study the effect of ag-zn zeolite on the micro geometry of the test surface and this device has surface analyzer to trace the profile of the surface irregularities. the profilometer records by its scale all the peaks and recesses which characterized the surface of the acrylic specimens, which were placed at stable bench. three different location were selected for each specimen (the same for all specimens) then the analyzer pass along the specimen surface for 11 mm distance then the mean of three readings were recorded for each specimen. surface hardness test: specimens of heat cure acrylic resin were prepared with a dimension (65mm ×10 mm× 2.5 mm±0.2mm).all specimens were left in distilled water at37°c48 hours until tested (11). test was performed using durometer hardness tester (shore d hardness) that was fabricated according to american national standard/ american dental association (13) which is suitable for acrylic resin material. the instrument consisted of blunt-pointed indenter 0.8mm in diameter that tapered to a cylinder 1.6mm.the indenter is attached to a digital scale that is graduated from 0 to 100 units. the usual method is to press down firmly and quickly on the indenter and record five maximum reading as shore hardness, measurement were taken directly from the digital scale reading. five measurements were done on different areas of each specimen (the same selected area of each specimen and the average of the five readings was calculated. water sorption and solubility test: acrylic disc specimens were prepared by using metal pattern with a dimension of (50 mm ± 1 mm in diameter and 0.5 mm ± 0.1 mm in thickness). (11). the specimens were dried in desiccators containing freshly dried silica gel. the desiccator was stored in an incubator at37°c ± 2oc for 24 hours after that the specimens were removed to room temperature for one hour then weighed with a digital balance with an accuracy of (0.0001g). this cycle was repeated until a constant mass (m1) "conditioned mass" was reached which 2bd2 3pi j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 65 indicated that the weight loss from each disc was not more than 0.5mg in 24 hours (11) the two groups reached to ml after 4 days, then all discs of both groups were immersed in distilled water for 7 days at 37°c ± 2°c (11). the discs were removed from the water with a dental tweezers wiped with a clean dry towel until free from visible moisture and weighed one minute after removal from the water; this mass was recorded as (m2). the value of water sorption were calculated for each disc from the following equation: (11) s mm wsp 12 − = wsp : water sorption in mg/cm2 2m : the mass of the disc after immersion in distilled water (mg) 1m : the mass of the disc before immersion in distilled water (conditioned mass) (mg) s : surface area of the disc (cm2) in order to obtain the value of solubility the discs were again reconditioned to a constant mass in the desiccators at 37°c ±2oc and weighed every 24 hrs as done in the first time for sorption test and the reconditioned mass was recorded as( 3m ). the whole group was reached to m3 within 4 days. the solubility was determined for each disc by the following equation: s mm wsl 31 − = (11) wsl: solubility ( mg/cm2) 1m : the conditioned mass (mg) 3m : the reconditioned mass (mg) s : the surface area of the disc ( cm2 ) color change measurement: a disc with same dimension and processing procedure that used for water sorption and solubility test were used for color change measurement. the color change was measured by the objective method (spectroscopic study) using spectrophotometer device by measuring the amount of absorbed light in nm. results the results were obtained from 120 experimental specimens of acrylic resin classified into: control group: no ag-zn zeolite added. experimental group: 0.5% concentration of ag-zn zeolite. results of the conducted tests includes: acharacteristic methods. bmechanical and physical test. the ftir spectra for pure and ag-zn zeolite showed the characteristic peaks of zeolite material. at the range of (400-4000cmˉ¹) fig.(1), both spectra of pure and ag-znzeolite were quite similar except shift of o-h and t-o stretching vibration observed in the spectrum of ag-zn zeolite. at the range of (200-400cmˉ¹) fig.(2) ,there was appearance of new peak at 217.94cmˉ¹and 243.01cmˉ¹.a peak splitting at 325.95cmˉ¹ into 327.88cmˉ¹ and 322.09cmˉ¹.a different peak intensity showed at 279.66cmˉ¹ for the spectrum of agzn zeolite; otherwise both spectra were the same. for the spectrum of pmma-zeolite composite fig. (3), was quite similar to that of the pure pmma except for the appearance of 2 new peaks at 1645.17cmˉ¹-1390.58cmˉ¹ and reduced intensities for the following peaks(1267.14cmˉ¹, 1242.07cmˉ¹, 1066.56cmˉ¹, 989.41cmˉ¹, 838.98cmˉ¹, 754.12cmˉ¹). figure 1: ftir spectrum atthe range of (200-400cmˉ¹) of ag-zn zeolite figure 2: ftir spectrum atthe range of (400-4000cmˉ¹) ag-zn zeolite j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 66 figure 3: ftir spectrum of pmma/ag-zn zeolite composite xrd patterns for both pure and agzn zeolite showed that the relative intensity of the characteristic peaks changed without any significant shift of the respective peak position. the chemical analysis carried out by atomic absorption spectroscopy showed the following composition 5%, 2% and 2.2% for sodium, sliver and zinc ions. while for particle size measurement, laser diffraction particle size analyzer results showed it in the range (0.5-1µm). impact strength test the results of the impact strength for heat cured acrylic resins specimens of the control group and the experimental group showed mean values of 8.68 and 8.43 kj/m2, respectively. t-test was used to examine the effect of agzn zeolite addition to pmma on the impact strength of acrylic resin. the result revealed a non significant difference between both group at p value ≤0.05. table 1: descriptive data and t-test of impact strength test results in kj/m2 materials descriptive statistics and t-test mean sd t-test pvalue sig. control 8.68 0.17 1.25 0.227 (ns) experimental 8.43 0.60 ns= non-significant transverse strength test from the table below, the mean value of transverse strength for the control group is 51.22n/mm² while for the experimental group is 50.90n/mm². t-test showed a non significant difference between both group at p value ≤0.05. table 2: descriptive data and t-testof transverse strength test results in n/mm² materials descriptive statistics and t-test mean sd t-test pvalue sig. control 51.22 2.56 0.27 0.788 (ns) experimental 50.90 2.67 ns= non-significant surface hardness test the samples of the control group showed a lower mean value of the surface hardness test which is equal to (84.19).although the experimental group showed a higher mean value than the control group which is equal to (85.37), ttest result revealed a non significant difference between both groups at p value ≤0.05. table 3: descriptive data and t-test of surface hardness test results materials descriptive statistics mean sd t-test p-value sig. control 84.19 1.51 -1.46 0.163 (ns) experimental 85.37 2.06 ns= non-significant surface roughness test the mean value of the surface roughness test for control group was higher than that of the experimental group which are equal to (1.81, 1.73) respectively. t-test showed a non-significant difference between both groups table 4: descriptive data and t-test of surface roughness test results materials descriptive statistics and t-test mean sd t-test p-value sig. control 1.81 0.22 0.59 0.562 (ns) experimental 1.73 0.36 ns= non-significant water sorption test a higher mean value was for the control group (0.3mg/mm²) while for the experimental group was (0.28mg/mm²). t-test was highly significant with p value of (0.000) suggested a highly significant statistical difference between both group. table 5: descriptive data and t-testwater sorption test results (mg/cm²) materials descriptive statistics and t-test mean sd t-test p-value sig. control 0.30 0.01 4.64 0.000 (hs) experimental 0.28 0.01 hs= highly significant water solubility test the mean value of the experimental group was higher than that of the control group which equal to (0.06, 0.03 mg/cm²) respectively. t-test result revealed a significant difference between both group at p value ≤0.05. j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 67 table 6: descriptive data and t-test of water solubility test results(mg/cm²) materials descriptive statisticsand t-test mean sd t-test p-value sig. control 0.03 0.02 -2.20 0.041 (s) experimental 0.06 0.04 s = significant color change measurement the mean value for the experimental group and the control group were equal to (1.18, 1.14) respectively. statistically a non significant difference between both groups according to t-test result at p value ≤0.05. table 7: descriptive data and t-test of color change measurement results materials descriptive statistics and t-test mean sd t-test p-value sig. control 1.14 0.04 -1.04 0.312 (ns) experimental 1.18 0.10 ns=non-significant discussion preparation, addition and characterization of ag-zn zeolite: this study selected the preparation and the use of zeolite as a vehicle for antimicrobial cations such as sliver and zinc ion due to its sorption and ion exchange properties. this in agreement with orha et al. (14) sliver and zinc ion were used as the cations of choice to be used in denture base material because they possess strong antibacterial and antifungal activity, this in agreement with abe et al.(15) that assessed the incorporation of sliverzinc zeolite into tissue conditioner to improve the antimicrobial property. the best concentration of ag-zn zeolite was 0.5%which showed the least and negligible adverse effect on acrylic resin properties in the same time it had antifungal properties as found by mutneja et al.(16) the result of aas showed comparable ion concentration was obtained for both sliver and zinc ion in order to obtain the same antimicrobial effectiveness of both ions. this agreed with kaali et al.(17). the results of ftir for zeolite before and after ion exchange showed some changes due to the ion exchange. the change of vibration bands of t-o asymmetrical and symmetrical stretching in the range of (400-4000cmˉ¹) also in the range of (200400cmˉ¹) the changes and the appearance of new peaks all indicate the incorporation of sliver and zinc ion into zeolite. this in agreement with orha et al. (14). the ftir spectrum of pmmaag-zn zeolite, recorded the changes as the appearance of the vibration band at 1639.33cmˉ¹and the disappearance of the vibration band at 9791200cmˉ¹ which belong to the zeolite spectrum could be due to the interaction between pmma and the ag-zn zeolite and this could explain that some mechanical properties of pmma such as impact and transverse strength, surface hardness and roughness weren’t changed, also it could explained the reduced in water sorption test. the xrd patterns of both pure zeolite and modified zeolite were almost similar; also no crystalline pattern was observed for ag and zn ion that could be because their fine distribution in zeolite lattice indicating that the incorporation of ag and zn had little effect on crystalline structure of host zeolite. these results comparable were with zendehdel et al.(18) also in agreement with orha et al.(14). impact strength test the results of impact strength test showed that the addition of 0.5% of ag-zn zeolite powder to heat cure acrylic resin had a non significant effect on the impact strength .it may be due to the small particle size in range between (0.5-1µm) and small percentage of zeolite added. these results were explained by that adding sliver-zeolite to heat cure resin tend to decrease the material property depending on the additive concentration of the antimicrobial zeolite (19). also in agreement with casemiro et al, (6) and coincided with hassan et al., (20). transverse strength test the current study showed that the addition of the 0.5% of ag-zn zeolite causes a non significant change in the transverse strength values. nakanoda et al., (19) found that small amount of antimicrobial zeolite added to acrylic resin had less effect on material property. this disagree with the result of with casemiro et al., (6) and mini et al., (21)who found a significant decrease of flexural strength in comparison to the control groups was observed with the addition of 2.5% of zeolite. this can be explained by high percentage of the added zeolite in comparison to the current study. surface hardness test although the mean value of the surface hardness test for the experimental group was higher than that of the control group but it was statistically insignificant under the explanation that zeolite mainly composed of silica with small particle size and high surface area leading to better interfacial adhesion of the composite material (22). j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 68 this was in similarity alnamel, (23) who found that the increase in surface hardness of acrylic resin after the addition of silicon dioxide may be attributed to the randomly distributed particles of a hard material in acrylic matrix. surface roughness test results showed that both experimental and control group had comparable mean values of surface roughness test which was statistically insignificant. this could be due to small percentage of the ag-zn zeolite with small particle size and well dispersion so few particles would be involved with the surface of the specimens, also the profilometer which was used in measuring the surface roughness was concerned with the outer surface of the composite specimen and not with the inner surface that's why the surface roughness of the experimental group was not increased. this result was comparable with both alnamel (23) and noori (24). water sorption test from the result of this study there was a highly significant difference between the mean values of both groups as the experimental group showed a lower mean value than the control group. as acrylic resins absorbed water slowly over a period of time, primarily because of the polar properties of the resin molecules and by the addition of filler particles, the actual number of pmma molecules available on the surface of the specimen for water sorption to occur decreased as compared to the control group (25, 26) the results also in agreement with kaali et al. (17) although zeolite is a hygroscopic material and its content in the composite may result in an increase in water uptake but this hygroscopic behavior of zeolite depend on its amount in the composite as the zeolite content in the composite. also they found that the different ion within zeolite framework may influence zeolite hygroscopic behavior and water absorption as well. water solubility test the result of this test showed a significant increase in water solubility of the experimental group in comparison to the control group. this could be due to the ion exchange property of zeolite for the antimicrobial cations within its lattice with the surrounding environment. this needs further investigation and analysis for the released ions. this comparable with kaali et al. (17) who found through a sem examination of the surface of ag-zn -cu exchanged zeolite /poly urethane composite after in vitro degradation that surface alteration due to ion activity and the capability to diffuse to the surface of polymer and migrate out in order to form equilibrium between the bulk and the environment, lattice with the surrounding environment. this needs further investigation and analysis for the released ions. this comparable with kaali et al.(17) who found through a sem examination of the surface of ag-zn -cu exchanged zeolite /poly urethane composite after in vitro degradation that surface alteration due to ion activity and the capability to diffuse to the surface of polymer and migrate out in order to form equilibrium between the bulk and the environment. color change measurement using spectrophotometer in the present study the color of pmma before (control group) and after (the experimental group) the addition of ag-zn zeolite was measured using spectrophotometer device (27). the results of the color test showed that there was a non-significant difference in light absorption between both groups. this result may be duo to small percentage of zeolite added.(6,17) references 1. sesma n, lagana dc, morimoto s, gil c. effect of denture surface glazing on denture plaque formation. braz dent j 2005; 16: 129–34. 2. gueiros la, soares ms, lea˜o jc. impact of ageing and drug consumption on oral health. gerodontol 2009; 26: 297–301. 3. schierholz jm, lucas lj, rumpc a, pulverer g. efficacy of silver-coated medical devices. jhi 1998; 40: 257-62 4. zhang y, zhong s, zhang m, lin y. antibacterial activity of silver-loaded zeolite a prepared by a fast microwave-loading method. j mater sci 2009; 44: 457–62. 5. bracco p, brunella v, luda mp, brach dp. oxidation behaviour in prosthetic uhmwpe components sterilized with high-energy radiation in the presence of oxygen. polymer degradation and stability 2006; 91: 3057-64 6. casemiro la, gomes martins ch, panzeri fc, pires d, panzeri h. antimicrobial and mechanical properties of acrylic resin incorperated sliver-zinc zeolite –part i. gerodontol 2008; 23: 187-94 7. mutneja p, raghavendraswamy kn, gujjariak.flexural strength of heat cure acrylic resin after incorporation of different percentage of sliverzinc zeolitean invitro study . ijci 2013; 4(4):25-31. 8. ay h. single and multicomponent ion exchange of silver, zinc and copper on zeolite 4a. a master thesis, middle east technical university, 2008. 9. xia x, hao d, ken wb. preparation and performance of ag-zn zeolite antimicrobial and antibacterial plastic. amr 2010; 96:151-54. 10. iso 179-1:2000: international standard organization. plastics -determination of charpy impact properties -part 1: non-instrumented impact test. j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 69 11. american dental association specification no.12. guide to dental materials and devices. 10th ed. chicago; 1999. p: 32. 12. anusavice kj. philips science of dental material. 11th ed. middle east and african edition; 2008; 143-166, 721-756. 13. american national standards institute/american dental association specification no.12. denture base polymers. chicago; 2002 14. orha c, manea f, ractiu c, burtica g, iovi a. obtaining and characterization of romanian zeolite supporting sliver ion. eemj 2005; 6(6): 541-44. 15. abe y, ishii m, takeuchi m, ueshige s, tanaka s, akagawa y. effect of saliva on an antimicrobial tissue conditioner containing silver-zeolite. j oral rehab 2004; 31: 568-73.(ivsl) 16. mutneja p, raghavendraswamy kn, gujjari ak.antifungal activity of heat cure acrylic resin after incorporation of different percentage of sliver-zinc zeolitean invitro study. ijci 2012; 4 (3): 49-54. 17. kaali p, pérez-madrigal mm, strömberg e, aune r e, czél g, karlsson s. the influence of ag+, zn2+ and cu2+ exchanged zeolite on antimicrobial and long term in vitro stability of medical grade polyether polyurethane. express polymer lett 2011; 5(12): 1028–40.(ivsl) 18. zendehdel m, kalateh z, alikhani h.efficiency evaluation of na y zeolite and tio2/ na y zeolite in removal of methylene blue dye from aqueous solutions. iran j environ health sci eng 2011; 8: 26572 19. nakanoda s, nikawa h, hamada t, yamamoto t, nakamoto t. the material and antifungal properties of antibiotic zeolite incorporated acrylic resin. j jpn prosthodont soc 1995; 26: 39 20. hassan a, wee yj, ahmad johari ul. impact strength of pvc-u-effect of calcium carbonate particle size. jcnre 2008; special edition, 35-40. 21. mini vs, alex mm, sudeep s, dinesh n.evaluation of flexural strength of provisional crown & bridge resins incorporated with silver-zinc zeolite. kdj 2013; 36(2): 116-22 22. rattanasupa bussaya. the development of rubber compound based on natural rubber and ethylene propylene diene monomer for playground rubber materials. a master thesis, kasetsart university, 2007 23. alnamel h, mudhaffar m. the effect of silicon dioxide nano-fillers reinforcement on some properties of heat cure poly (methyl methacrylate) denture base material. j bagh college dentistry 2014; 26(1):32-6. 24. noori ah. evaluation of thermal conductivity of alumina reinforced heat cure acrylic resin and some other properties. j bagh college dentistry 2010; 22(3):1-7 25. barsbymj.a denture base resin with low water absorption. j prosth dent 1992; 20: 240-44. 26. arora n, jain v, chawla a, mathur vp. effect of addition of sapphire (aluminium oxide) or sliver filler on the flexural strength, thermal diffusivity and water sorption of heat polymerized acrylic resin. ijoprd 2011; 1(1): 21-7. 27. nam ky, lee ch, lee cj. antifungal and physical characteristics of modified denture base acrylic incorporated with silver nanoparticles. gerodontol 2010; 29: 413–19. j bagh college dentistry vol. 28(4), december 2016 effect of black pedodontics, orthodontics and preventive dentistry 153 effect of black cardamom extracts on mutans streptococci in comparison to chlorhexidine gluconate and de-ionized water (in vitro study) sara i. khalil, b.d.s. (a) wesal a. al-obaidi, b.d.s. m.sc. (b) wifaq m. ali, m.b.ch.b., f.i.c.m.s. (c) abstract background: spices and herbs have been used by many cultures to enhance the flavor and aroma of food and for their medicinal value. black cardamom is one of these spices widely used in cooking because of its unique taste and powerful flavor. the aim of study was to test the effect of black cardamom on mutans streptococci in comparison to chlorhexidine gluconate (0.2%) and de-ionized water. materials and methods: dried fruits of black cardamom were extracted by using alcohol (70% ethanol). saliva was collected from seven volunteers. agar well technique with different concentrations of black cardamom extracts was used to test the sensitivities of mutans streptococci, as well black cardamom extracts effect on viable counts of mutans streptococci. results: mutans streptococci was sensitive to different concentrations of alcohol extracts of black cardamom in vitro starting with (5%) to (40%) using agar well diffusion technique. black cardamom was effective in inhibition of mutans streptococci but still weaker than chlorhexidine gluconate 0.2%. highly significant reduction in the counts of bacteria was reported with cardamom extracts and chx in comparison to neutral control after 2 hrs. conclusions: black cardamom showed an effect on mutans streptococci but still less than chx. key words: mutans streptococci, black cardamom, chlorhexidine, de-ionized water. (j bagh coll dentistry 2016; 28(4):153-157) introduction dental problems are very common among population and consider as the fourth most frequent illness condition, behind headache, high blood pressure and colds (1). the most common oral diseases affect oral cavity is dental caries and periodontal disease (2). the oral cavity is a complex system which can be altered by diverse factors including poor oral hygiene and diet, stress and systemic diseases which enhance the colonization by pathogenic bacteria and the formation of biofilm and their metabolism of fermentable carbohydrate leads to the formation of acids, biofilm imply the involvement of microbiological species most commonly mutans streptococci (3). mutans streptococci is anon-motile, gram positive bacteria and considered as primary causative agent of initial caries (4). the mutans streptococci are from the family: lactobacillaceae, genus: streptococci. s. mutans, occupies a substantial proportion of the microbiota that integrates the cariogenic biofilm, and their participation in the etiology of dental caries is very important (5). mechanical removal of dental plaque biofilm is a main factor in the prevention of oral diseases and might be associated with using agents which act particularly against cariogenic bacteria (6,7). (a) m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (b) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (c) assistant professor, department of microbiology, college of medicine, university of baghdad the optimal intervention for oral disease is not universally affordable because of high costs and limited resources, the use of chemical agents associated with many side effect (8,9). herbal medicines are increasingly used as dietary supplements for treatment against different human disorders with their safety and efficacy (10,11). the antibacterial effect of herbs and spices in medicine can be justified according to their easy absorbability by the body without having any adverse effects if taken in appropriate amount (12,13). black cardamom also known as amommum subulatum (a. subulatum) is a small herb which has strong aromatic smellswith a camphor-like flavor in the family zingiberaceae (14), thus nice flavor and aroma can stimulate the taste buds when used in savory dal preparations and rice (15). away from being used in a wide variety of sweets and beverages, it is also a common ingredient of pan masala and garam masala (16). black cardamom has many benefit in several dental disorders related to oral health such as teeth and gum infection (17,18). antimicrobial effect of black cardamom in vitro had been documented as effect against streptococcus mutans, staphylococcus aureus, lactobacillus acidophilus and candida albicans (19). the aim of this study was to test the effect of black cardamom extract on sensitivity and growth of mutans streptococci in comparison to chlorhexidine gluconate (0.2%) and deionized water. http://en.wikipedia.org/wiki/zingiberaceae j bagh college dentistry vol. 28(4), december 2016 effect of black pedodontics, orthodontics and preventive dentistry 154 materials and methods stimulated salivary samples were collected from seven healthy person from baghdad– university, college of medicine by chewing a piece of arabic gum, after disappearance of salivary foam, 0.1 ml of saliva is transferred to 0.9 ml of sterile phosphate buffer saline (pbs) of ph 7.0-7.2 for microbiological analysis. ten-fold dilution were performed, the inoculum was withdrawn from (10-3), 0.1 ml was taken and spread in duplicate on the mitis salivarius bacitracin (msb) agar which is the selective media for mutans streptococci. the plates were incubated anaerobically for 48 hrs., then aerobically for 24 hrs. at 37oc. the colonies of mutans streptococci were determined according morphological characteristic and gram’s stain (20). biochemical test for bacterial identification was done using cysteine tripticase agar media, thus test the ability of bacteria to ferment sugar. agar well technique was applied to study the antibacterial effects of different concentrations of alcoholic black cardamom extracts (5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%), compared with chlorhexidine 0.2% as a control positive and de-ionized water as control negative on mha media. these experiments were conducted on 7 isolates of mutans streptococci. mha used in this experiment which were prepared and sterilized previously in sterile petri dish plates. to several plates mutans streptococci inoculum was spread, left at room temperature for 20 minutes. several wells of equal size and depth were prepared in each agar plate; each well was filled with 0.1 ml of the test agent. plates were left at room temperature for 1 hour then incubated aerobically for 24 hrs. at 37oc. zone of inhibitions which is clear zone of no growth of the bacteria were measured across the diameter of each well by using a ruler. the viability counts of mutans streptococci from broth media, to which different concentrations of alcoholic extracts of black cardamom, chx 0.2% and de-ionized water were added have been estimated in comparison to the control (broth and bacteria only). the procedure was carried on 4 isolates of mutans streptococci, the concentrations were 10%, 15%, 20%, 25%, 30%, 35%, 40% of alcoholic cardamom extracts. brain heart infusion broth (bhi) was used which distributed in test tubes by 8.9 ml to each tube, 0.1 ml of the test agents was added to each tube except the control which was broth and bacteria only (21). from the control tube 0.1ml was transferred to 0.9 ml of sterile normal saline. ten-fold dilution was performed, from dilution 10-5, 0.1 ml was taken and spread in on msb agar plates, incubated anaerobically at 37oc for 48 hrs. the colony-forming unit per milliliter (cfu/ml) was counted. this value was considered as the initial count of bacteria. study and control broth cultures were incubated aerobically for two hours at 37oc. from each broth 0.1 ml was transferred to 0.9 ml of sterile pbs (ph 7.0) and ten-fold dilutions were performed. from dilution and 10-5, 0.1 ml was taken and spread on msb agar plates and was incubated anaerobically for 48 hrs. at 37oc. the colony-forming unit per milliliter (cfu/ml) was counted. data processing and analysis were carried out by using spss program version 19, which provide mean and standard deviation of the variables in the study and analysis of variance (anova) for testing the significant differences among means of different groups. lsd was used with anova with significant result, paired t-test also used to compare the difference between two means of the same group. the analysis was accepted at p < 0.05, as the limit of significance, when p < 0.01 were regarded as highly significance. results black cardamom extracts were prepared by a method for alcoholic extract, with a dark brownish black, oily and viscous consistency (figure-1). mutans streptococci colonies are spherical or ovoid in shape with raised or elevated surface, light blue in color, and about 1-2 mm in diameter (figure-2). mutans streptococci cells were gram positive, spherical or ovoid in shape, arranged in short or medium length non-spore forming chains as shown in (figure-3). mutans streptococci colonies have the ability to ferment mannitol. a positive reaction was indicated by changing in color from red to yellow by formation of acid after incubation (figure-4). in the sensitivities of mutans streptococci to different concentrations of black cardamom, chx and deionized water in vitro, the diameter of inhibition zone was found to increase as the concentrations of extracts increased. de-ionized water showed no zone of inhibition while chx showed the highest zones of inhibition compared to black cardamom extracts, as one way anova was performed among black cardamom, chx and d.w. (table-1). the counts of mutans streptococci were tested used black cardamom, chx, de-ionized water and control (broth+ms) (table-2). paired ttest was used to compare between initial count of bacteria j bagh college dentistry vol. 28(4), december 2016 effect of black pedodontics, orthodontics and preventive dentistry 155 and count of bacteria after 2 hrs. statistically, highly significant increase in number of bacteria was recorded after 2 hrs (table-3). anova test and lsd among agents in comparison with initial counts and counts after 2 hrs. were also showed (table-4) and (table-5). figure 1: black cardamom extract product figure 2: mutans streptococci on msba. figure 3 gram’s stain for mutans streptococci cell figure 4: biochemical identification for mutans streptococci a: positive control group (agar and bacteria without mannitol). b: study group (agar and mannitol inoculated with ms). c: negative control group (agar and mannitol without bacteria). table 1: mutans streptococci inhibition zone to different concentrations by different agents using (agar well diffusion methods). agents no. * mean ± s.d anova test chx 7 19.14 1.06 f=165.16 p= 0.00 df= 9 hs large cardamom 5% 7 0.57 0.78 large cardamom 10% 7 2.42 0.78 large cardamom 15% 7 4.85 1.21 large cardamom 20% 7 6.62 1.16 large cardamom 25% 7 7.85 1.67 large cardamom 30% 7 8.08 1.08 large cardamom 35% 7 8.14 1.67 large cardamom 40% 7 9.00 0.81 d.w. 7 0 0 *(mm) a b c j bagh college dentistry vol. 28(4), december 2016 effect of black pedodontics, orthodontics and preventive dentistry 156 table 2: effect of different concentration of large cardamom extracts, chx and de-ionized water on viable count of ms x105 in vitro. agents no. *mean ±sd anova test alcoholic extract 10% 4 130.00 4.71 f= 8.775 p=0.02 df= 8 s alcoholic extract 15% 4 100.00 0.41 alcoholic extract 20% 4 85.00 5.81 alcoholic extract 25% 4 73.87 7.50 alcoholic extract 30% 4 45.00 12.24 alcoholic extract 35% 4 41.25 10.30 alcoholic extract 40% 4 28.00 5.71 chx 4 7.00 3.46 d.w. 4 212.50 14.43 *(cfu/ml) table 3: initial count of ms and count of it after 2 hrs. (x105). *mean ±sd paired t-test initial count 135.0 28.86 t= -14.20 p=0.00 df=3 hs count after 2 hrs. 237.5 14.43 * (cfu/ml) table 4: anova test among agents with initial counts and counts after 2 hrs. anova test agents initial count f= 27.71 p= 0.00 hs black cardamom chx d.w. f= 143.55 p= 0.00 hs count after 2 hrs. table 5: lsd between agents in comparison with initial counts and counts after 2 hrs. large cardamom conc. initial count count after 2 hrs. *mean difference p value description *mean difference p value description 10% -5.00 0.64 ns -107.50 0.00 hs 15% -35.00 0.00 hs -137.50 0.00 hs 20% -50.00 0.00 hs -152.50 0.00 hs 25% -61.25 0.00 hs -163.75 0.00 hs 30% -90.00 0.00 hs -192.50 0.00 hs 35% -93.75 0.00 hs -196.25 0.00 hs 40% -107.00 0.00 hs -209.50 0.00 hs chx -128.00 0.00 hs -230.50 0.00 hs d.w. 77.50 0.00 hs -25.00 0.03 s *(cfu/ml) discussion the primary role of the salivary mutans streptococci is to predict the future incidence of dental caries (22). mutans streptococci play an important role in the development and progression of dental caries (23,24). stimulated saliva samples were superior for the reason that they yielded higher levels of mutans streptococci with lower sample variance than with unstimulated saliva (25). in the biochemical identification, yellow color indicated that enough acid was produced by fermentation of the sugar (manitol) to lower the ph to 6.8 or less. black cardamom with alcoholic extract with different concentrations was shown an effect on mutans streptococci by tested with two experiments (sensitivity and viable count). the effect of black cardamom increased as the concentration increased. the results showed that black cardamom extract was able to inhibit the growth of mutans streptococci by affecting on zone of inhibition which increased as the j bagh college dentistry vol. 28(4), december 2016 effect of black pedodontics, orthodontics and preventive dentistry 157 concentration increased from 5% to 40, at the same time the viable count showed a highly significant reduction of mutans streptococci with concentrations 10% to 40% compared to the control. this finding was in coincidence with other studies (19,26). all concentrations of black cardamom extract were shown lower inhibition zone than chx, it's a potent antibacterial agent practically against mutans streptococci (27). the de-ionized water had zero effect on the bacteria appearing by absence of inhibition zone. the results of black cardamom in the present study and its low price compared with green cardamom and more popularity in many countries in the world; give a great hope to import and use black cardamom in the life as food additive as well as in many medical and dental applications, not as a substitution for green cardamom but as a unique spice used in many spicy dish. also there extractions were used as an ingredient in many antibacterial materials like mouth wash and dentifrices. references 1. brennan d, spencer a. disability weights for the burden of oral disease in south australia. population health matrics 2004; 2: 7. 2. snyder, haveman j. burden of oral disease in machigan. machigan department of community health, 2013. 3. tressaud a, haufe g. fluorine and health: molecular imaging, biomedical materials, and pharmaceuticals. uk: elsevier; 2008: pp.521. 4. dowd s. escherichia coli o157: h7 gene expression in the presence of catecholamine norepinephrine. fems microbiol left 2007; 273: 214-23. 5. foressten s, bjorklund m, ouwehand a. streptococcus mutans, caries and stimulation models. nutrients j 2010; 2(3): 290-8. 6. zanela n, bijella m, rosa o. the influence of mouth rinses with antimicrobial solutions on the inhibition of dental plaque and on the levels of mutans streptococci in children. braz oral res 2002; 16: 101-6. 7. xiao j, zhou x, feng j, hao y, li j. activity of nidus vespae extract and chemical fractions against streptococcus mutans biofilm. lett appl microb 2006; 45: 547-52. 8. rangan c, barceloux d. food additives and sensitivities. dis mon j 2009; 55: 292-311. 9. wroblewska b. influence of food additives and contaminants (nickel and chromium) on hypersensitivity and other adverse health reactions: a review. pol j food nutr sci 2009; 59: 287-94. 10. rajani m, kanaki n. phytochemical standardization of herbal drugs and polyherbal formulations: bioactive molecules and medicinal plants. berlin: springer; 2008. pp. 349-69. 11. rai m, chinkindas m. natural antimicrobial in food safety and quality. cabi publishing; 2010. 12. erdogrul o. antibacterial activities of some plant extracts used in folk medicine. pharm biol 2002; 40: 269-73. 13. edeoga h, okwu d, mbaebie b. phytochemical constituents of some nigerian medicinal plants. afr j biotechnol 2005; 4: 685-8. 14. bisht v, negi j, bhandari, sundriyal r. amomum subulatum roxb: traditional, phytochemical and biological activitiesan overview. african j res 2011; 6(24): 5386-90. 15. troy d, beringer p. remington: the science and practice of pharmacy. 21st ed. lippincott williams and wilkins; 2006. 16. dubey k. the indian cuisine. phi learning pvt ltd, 2010. pp. 63. 17. dutta s, ahmed r, pathak m. essential oil composition of amomum linguiforme benth, northeast india. indian perfum 2000; 44: 11–13. 18. sabulal b, dan m, pradeep n. composition and antimicrobial activity of essential oil from cardamom. acta pharm 2006; 56: 473-80. 19. aneja k, joshi r. antimicrobial activity of amomum subulatum and elettaria cardamomum against dental caries causing microorganisms. j ethnobotanical 2009; 13: 840–9. 20. koneman e, schreckenberge p, allens s, jr w, janada w. diagnostic microbiology. 4th ed. j.b. lippincott co.; 1992. 21. baron e, peteson l, fingold s. methods for testing antimicrobial effectiveness. in: bailey and scotts diagnostic microbiology. 9th ed. st. louis: cv mosby co.; 1994. 22. shi s, deng q, hayashi y, yakushiji m, machida y, liang q. a followup study on three caries activity tests. j clin pediatr dent 2003; 27: 359-64. 23. nomura y, hanada n. correlation of cariogenic bacteria and dental caries in adults. j oral sci 2006; 48(4): 245-51. 24. aas j, griffen a, dardis s, lee a, olsen i, dewhirst f, leys e, paster b. bacteria of dental caries in primary and permanent teeth in children. j clin microbiole 2008; 46 (4): 1407-17. 25. gu f, lux r, anderson m, del aguila m, wolinsky l, hum w, shi w. analysis of streptococcus mutans in saliva with speciesspecific monoclonal antibodies. hybridoma and hybridomics 2002; 21: 225-33. 26. nair r, kalariya, t, sumitra c. antibacterial activity of some selected indian medicinal flora. turk j biol 2005; 29: 41-7. 27. fejerskov o, kidd e. dental caries, the disease and its clinical management. 2nd ed. blackwell munkgard ltd, 2008. j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 45 clinicopathological and immunohistochemical analysis of 21 cases of traumatic ulcerative granuloma with stromal eosinophilia using cd30, cd68 and tgf-β1 mustafa basim al-talqani, b.d.s. (1) bashar hamid abdullah, b.d.s., m.sc., ph.d. (2) ameer dhahir hameedi, mbchb, ficms (path) (3) abstract background: traumatic ulcerative granuloma with stromal eosinophilia is an impressive benign chronic ulcerative lesion of the oral mucosa with vague etiopathogenesis. it was supposed to represent an oral counterpart of primary cutaneous cd30+ lymphoproliferative disorder. histopathologically, it is characterized by mixed inflammatory infiltrate predominated by histiocytes, lymphocytes and eosinophils along with presence of scattered large atypical mononuclear cells. it has worrisome clinical presentation. it may heal spontaneously, but in most occasions it persists and never heal unless removed surgically (incisional or excisional biopsy). a rare subset may show worrisome immunohistochemical features. follow up is highly recommended. materials and methods: formalin fixed paraffin embedded tissue blocks of twenty-one cases were cut and mounted on positively charged slides and stained by primary antibodies (cd30, cd68 and tgf-β1). a statistical analysis was performed between the immunohistochemical scores for markers with each other and with clinicopathological parameters (age, sex, size of ulcer, number of eosinophils and mitoses). results: the age of the patients ranged from 20 to 72 years, with a higher female propensity. immunohistochemical positive expression for cd30 (16 case) mainly involved round small lymphocytes, while all cases were positive for cd68 and tgf-β1. statistically, there was no significant relation between the scores of cd30, cd68 and tgf-β1 with each other and with the aforementioned parameters, (p<0.05). the eosinophils count showed a significant positive correlation with age (p=0.008), size of ulcer (p=0.007) and mitoses (p=0.004). conclusion: traumatic ulcerative granuloma with stromal eosinophilia is a benign and reactive chronic oral ulcerative lesion rather than being cd30+ lymphoproliferative disorder; this conclusion is supported by heterogeneous, focal and nonspecific staining for cd30 and being typically infiltrated by cd68+ macrophages. whereas, a high level of expression for tgf-β1 indicated that the aforementioned factor was not associated with the delayed healing of this lesion. (received: 12/9/2018; accepted: 17/10/2018) introduction traumatic ulcerative granuloma with stromal eosinophilia (tugse) is an oral ulcerative lesion of much interest for many medical specialties (oral pathology, dermatology, dentistry, surgery, and otolaryngology); so that, various terms have been used to identify this lesion[1]. the story of appellation began in the fifties of the 20th century until the 1st decade of 21st century. at the first attempts, tugse was erroneously called xanthogranuloma, nevoxanthoendothelioma, juvenile xanthoma and eosinophilic granuloma[2]. thereafter, it was termed traumatic granuloma of the tongue[2]; ulcerated granuloma eosinophilicum diutinum of the tongue[3]; eosinophilic granuloma of the tongue[4]; eosinophilic ulcer of the tongue[5]; traumatic eosinophilic granuloma of the gingiva[6]; ulcerative eosinophilic granuloma of the tongue[7]; traumatic ulcerative granuloma with stromal eosinophilia (tugse)[8]; eosinophilic ulcer of the oral mucosa[9] and abbreviated as (euom)[10]; ulcerative eosinophilic granuloma (ueg)[11]; traumatic eosinophilic granuloma (teg) of the oral mucosa[12]; and oral traumatic granuloma (tg)[13]. unknown”, “poorly understood”, “not clear”, “debatable”, “obscure", “unclear”, “uncertain”, “controversial”, all of these terms have been used to illustrate the etiopathogenesis of tugse. until nowadays, the etiopathogenesis of tugse is a matter of controversy and the enigma of tugse etiopathogenesis is yet be unraveled. among all etiological factors, mucosal trauma appeared to be the major instigating factor of this lesion[2, 14]. however, it was assumed that if the trauma was the sole cause, tugse would be more common; therefore, it was suggested that viral or toxic agents might enter into the underlying tissue and result in an inflammatory response and tissue damage[7]. then, virus-related etiopathogenesis was suggested[15, 16]. however, the possibility of viral-mediated etiopathogenesis was discarded[1720]. furthermore, a hypothesis of cell-mediated pathogenesis was suggested[10, 21]. with a diverse point of view, it was proposed that the chronicity of tugse might be caused by an underlying defect in the healing process that resulted from a university of baghdad. (3) lecturer, pathology department and forensic medicine, college of medicine, university of baghdad. (1) college of dentistry, university of kufa, iraq (2)professor, department of oral diagnosis, college of dentistry, j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 46 lack of expression of transforming growth factorα (tgf-α) and transforming growth factor-β (tgfβ) by eosinophils infiltrating such a lesion[22]. clinically, tugse is characterized as a solitary benign chronic oral ulcer, with the tongue being the most common site to be affected; however, it may present elsewhere in the oral cavity such as lips, gingiva, palate, vestibular mucosa, retromolar area and floor of the mouth[14, 21]. it has an important clinical significance, since it may be provisionally diagnosed as oral squamous cell carcinoma (oscc) because of its worrisome clinical presentation as a chronic oral ulcer with elevated and rolled margins that fails to heal by means of local treatment[23]. histopathologically, tugse is presented as an ulcerated lesion composed of a poorly formed granulation tissue showing a mixed inflammatory infiltrate that is composed of histiocytes, lymphocytes, eosinophils, plasma cells and large atypical mononuclear cells; the eosinophilic infiltrate in tugse lesions is characteristic and fundamental for the diagnosis, since most of the oral traumatic ulcers are devoid of such heavy eosinophilic infiltrate[23]. the inflammatory infiltrate affects the superficial and deep layers of the muscular tissue and penetrates into underlying soft tissue. large atypical mononuclear cells with ovoid and pale-appearing nuclei are scattered and may be mitotically active[24]. by immunohistochemistry, it was revealed that the cells that made up the characteristic infiltrate of large round cells expressed the macrophage marker (cd68) or the dendrocyte marker (factor xiiia)[25], the lymphocytic infiltrate was composed predominantly of t cells[10]. interestingly, tugse was suggested to represent an oral counterpart of cutaneous cd30+ lymphoproliferative disorder (lpd)[12, 18]. while on the basis of molecular and immunohistochemical features, it was quite conceivable to suggest that tugse symbolized an umbrella term covering a spectrum of lesions with diverse cells of origin[17]. this study aimed at the assessment of clinicopathological and immunohistochemical features of tugse to reach a favorable consensus about the nature, behavior, etiopathogenesis, cellular characteristics and optimal diagnostic criteria of such mysterious oral ulcerative lesion. the immunohistochemical markers in this study were (cd30, cd68 and tgf-β1). materials and methods formalin fixed-paraffin embedded tissue blocks (incisional and excisional biopsies) of twenty-one cases of tugse were retrospectively retrieved. the diagnosis was made according to the criteria in table (1). tissue sections (5μm) were cut and mounted on positively charged slides and stained immunohistochemically with polyclonal antibodies to cd30 (ab203593, 1:100), cd68 (ab203101, 1:200) and tgf-β1 (ab92486, 1:200) using expose mouse and rabbit specific hrp/dab detection ihc kit (ab80436, 15ml). immunohistochemical signal specificity was demonstrated by the presence of a brown granular dab staining pattern within the specific tissue compartment for a certain antibody in positive control tissue sections according to manufacturer’s datasheets, and the absence of such staining in negative controls tissue slides. five representative fields were selected for each tissue section in all primary antibodies, visualized and scored microscopically with a 400x objective; the average percent of the five high power fields was calculated for each marker. all cases were blindly evaluated without prior knowledge of the other parameters. the immunohistochemical staining for cd30, cd68 and tgf-β1 antibodies was measured semiquantitatively and assigned into categories for each one, as follows: cd30 scoring: 0 (none); 1 (less than 30%); 2 (30% to 50%); 3 (more than 50%)[24]. cd68 scoring: 0 (none); 1 (less than 25%); 2 (25% to 50%); 3 (50% to 75%); 4 (more than 75%)[21]. tgf-β1 scoring: 0 (0% to 10%); 1 (10% to 25%); 2 (25% to 50%); 3 (more than 50%)[26]. table 1: diagnostic criteria that were considered for diagnosis of tugse in the current study.* diagnostic criteria of tugse clinical criteria:  almost persistent ulcer, sometimes with raised and indurated borders.  resistance to local treatment for at least 2 weeks.  implication of antecedent trauma is usual, but not mandatory. histologic criteria:  ulcerated mucosa with surrounding epithelium that is usually hyperplastic.  underlying connective tissue is infiltrated by mixed inflammatory cells mainly histiocytes, lymphocytes admixed with increased number of eosinophils (poorly formed granulation tissue).  stromal eosinophilia is a must diagnostic criterion.  presence of large atypical cells with pale staining nuclei admixed with the inflammatory infiltrate.  extension of such infiltrate to deep structures (skeletal muscle fibers and salivary glands).  skeletal muscle fibers show signs of regeneration and degeneration.  presence of mitoses is not uncommon immunohistochemical criteria:  positive expression of cd68 marker is must.  heterogeneous positive expression of cd30 marker, which may be absent in some cases. * the diagnostic criteria were derived from the data of previous literature and observations in the current study. j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 47 results clinical description: the age of the patients ranged from 20 to 72 years old with a mean of 53 years and a higher incidence at the fifth to seventh decade. data regarding sex distribution among cases revealed a higher female propensity (15/21, 71.4%) than that for males (6/21, 28.6%), with male-to-female ratio was equal to 1:2.5. regarding site affected, the tongue (especially the dorsum and lateral borders) was involved in all but one case, which involved the upper lip. the data regarding the size of the ulcers were gathered from clinical information of some cases and measured from the received surgical specimen of the rest of cases; however, it ranged from 0.2cm to 1.56cm with a mean of 1.03cm. information about the duration of the lesion was lacking in a half of cases; however, available data revealed that the duration ranged from 1 month up to 1 year with a mean of 3.2 months. gross and histopathological findings: the gross examination of the specimens of tugse (incisional and excisional biopsies) revealed whitish, grayish, whitish-gray or grayishwhite soft tissue lesions. the size of specimens ranged from 0.4cm to 4cm in diameter, where some excisional biopsies included the ulcerated area with a safe margin because of suspicion of oscc (fig. 1). figure 1: cut section of an excisional biopsy of tugse at the lateral border of the tongue, one suture refer to superior border and double sutures refer to anterior border (specimen included safe margin resection). microscopically, sections showed ulcerated stratified squamous epithelium. the underlying stroma showed a mixed chronic inflammatory cell infiltrate composed mainly of histiocytes, lymphocytes, and varying numbers of eosinophils in between degenerative-regenerative skeletal muscle fibers (fig. 2). however, other cellular components such as mast cells and plasma cells were also present, but in smaller proportions, in addition to few scattered large atypical cells. the presence of eosinophilia is characteristic of tugse, where the other oral traumatic ulcers are devoid of such a tissue eosinophilia. the number of eosinophils for each case was counted and ranged from 10 to 50 eosinophilic leukocyte per 10 high power fields (hpf). mitoses were present in 11 cases with the highest count was equal to two mitotic figures per 10 hpf (fig. 3). figure 2: high power photomicrograph of tugse showing a mixed chronic inflammatory cell infiltrate composed mainly of histiocytes, lymphocytes, and eosinophils (h&e, x400). figure 3: photomicrograph of tugse showing a mitotic figure (at the tip of the pointer) (h&e, x400). regarding tissue eosinophilia, there was a significant positive correlation between j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 48 eosinophils count and age (p=0.008) and size (p=0.007); while, there was no significant correlation with duration (p=0.495). additionally, there was no significant difference in eosinophils count between males and females (p=0.709). while for mitoses, there was neither significant correlation between mitosis and age (p=0.263), size (p=0.122) and duration (p=0.805) nor significant difference in mitosis between males and females (p=0.522). immunohistochemical findings: the expression of cd30 was positive in 16 case (>75% positive cells in three cases) and mainly involved the round small lymphocytes, but some of the large atypical cells were, also, cd30 positive (fig. 3, a). statistically, cd30 had no significant relation with sex (p = 0.216). similarly, there was no significant difference in cd30 score groups with age (p=0.357), duration (p=0.717) and size (p=0.171). all cases were cd68 positive with positivity varied from 9.7% up to 97.8% as brown membranous staining of histiocytic mononuclear cells (fig. 3, b). statistically, there was no significant relation between cd68 scores and sex (p=0.251); also, there was no significant difference in cd68 score groups with age (p=0.566), duration (p=0.205) and size (p=0.758). cytoplasmic, nuclear and/or extracellular matrix tgf-β1 positive expression were demonstrated in stromal tissue sections of all cases (fig. 3, c). in relation to demographic parameters, there was no significant relation between tgf-β1 and sex (p=0.347). furthermore, there was no significant difference in tgf-β1 score groups with age (p=0.072), and size (p=0.689), but there was a significant difference in the duration (p<0.05). correlations among immunohistochemical markers: using pearson’s correlation, no significant correlations were evident between immunohistochemical markers studied; tgf-β1 and cd30 score groups (p=0.347); tgf-β1 and cd68 score groups (p=0.390); cd30 and cd68 score groups (p=0.117). however, there was a positive significant correlation between and mitoses (p=0.004), while there was no significant correlation of eosinophils count with the other immunohistochemical markers (p>0.05). figure 4: high power photomicrograph showing the positive immunohistochemical expression of primary antibodies: a. cd30; b. cd68; c. tgf-β1. discussion generally speaking, tugse is not an uncommon oral lesion, but in iraq, it seems to be considered as a rare and recently delineated oral lesion that might be reflected by the general lack of awareness of this entity. however, the final sample of this study was comprised of 21 cases j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 49 that seems to be adequate to represent a reliable result. to the best of our knowledge, this study is the 5th largest series of cases of tugse in english language literature. all age cohorts can be affected; it has two peaks of incidence: the first peak occurs in children, mostly being related to eruption of primary anterior teeth that is referred to as rigafede disease (rfd)[8], while the second peak occurs in adults. the age of the sample in this study was in accordance with majority of the main series of cases of tugse (table 2). on the basis of data available in the literature, no dominant sexual predilection was apparent; male predominance[2, 30], female predominance[10, 20, 25, 28, 32] and equal male-to-female ratio[8, 21, 27, 29] have been reported (table 2). however, fluctuations of male-to-female among different series of cases of tugse necessitate further studying of this condition to reach a reasonable sequel. variation in duration might be attributed to that information was limited to estimations given by patients that might not be precise and affected by socioeconomic status of patients, where tugse may be presented as a painless lesion that can be neglected by some patients for a long period of time; however, it was consistent with many other studies of tugse (table 2). regarding the site affected; in this study, the tongue (especially the dorsum and lateral borders) was involved in all but one case, which involved the upper lip. similarly, the tongue was stated as the commonest site in all previous studies of tugse, with lip localization has been reported in few instances (table 2). trauma is considered as an inevitable cause related to tugse etiopathogenesis. unfortunately, this study lacked information about presence of history of trauma in 14 cases, with only 4 cases were reported with obvious previous source of traumatism (irritation from sharp root stumps or a badly carious tooth). accordingly, such high affinity of tongue involvement, as the most common site of tugse, seems reasonable since the tongue movement makes it more vulnerable to trauma. however, trauma, per se, could not be considered as a sole cause of tugse, where in this study, 3 cases reported without known history of trauma. similarly, both states of being traumatized or not have been reported by other authors (table 2). in the context of the size of ulcer, the results were nearly identical to those obtained by hirshberg et al.[21] and jayalakshmy et al.[32], slightly greater than those addressed by abdullah[29], while, in other studies[10, 27], the ulcers had much greater diameter; per contra, the rest if studies of tugse lacked information about such parameter (table 2). by examining hematoxylin and eosin (h&e) tissue sections, all cases in this study showed an ulcerated oral mucosa with mostly hyperplastic edges. the underlying stroma showed a mixed chronic inflammatory infiltrate comprised mainly of histiocytes, lymphocytes, mast cells, plasma cells and varying numbers of eosinophils in between degenerative-regenerative skeletal muscle fibers. additionally, large atypical cells have been found in varying numbers and distribution. mitoses were present in about half of cases. almost all previous series of cases of tugse (table 2) showed similar histopathological features. being correspondent with other studies of tugse, the eosinophilic infiltrate in this study was of varying densities among different cases and within the same case in different areas of the section; however, the eosinophils count in the current study was in agreement with findings of other authors, where a significant degree of tissue eosinophilia was recorded when it was possible to find more than ten eosinophils per hpf[27, 30]. the presence of tissue eosinophilia is not completely understood because most of oral traumatic ulcers are devoid of such increased eosinophils; however, such stromal eosinophilia may represent a tissue reaction to unknown antigens introduced through mucosal breakdown following trauma[21]. furthermore, mucosal degeneration that is so characteristic of tugse may be attributed to toxic products released by degranulating eosinophils[21]. however, the tissue eosinophilia might be resulted from release of cytokines from t-lymphocytes[10], or due to release of eosinophilic chemotactic factors by mast cells[8]. regarding statistical analysis of tissue eosinophilia, there was a significant positive correlation between eosinophils count with age (p=0.008) (supporting the higher incidence of tugse in advancing age, namely fifth to seventh decades of life) and with size (p=0.007) (as eosinophils react to macroorganisms, foreign antigens, viruses and other tissue breakdown products that will be, conveniently, increased with increasing size of its portal of entry, the ulcer). so that, besides that stromal eosinophilia is a characteristic feature of tugse, it is suggested here that the presence of tissue eosinophilia in sections of oral lesions is almost never nonspecific. the presence of mitoses is another interesting feature of the cellular infiltrate of tugse, but not an inherent finding that has been reported variably. in this context, 10 cases in this study j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 50 were mitosis-free, while, in the rest of cases, mitoses were identified in scattered cells and were not abundant with highest count was equal to 2 mitotic figures per 10 hpf. in comparison with other studies in literature, many of them were lacking to evaluate this parameter; nevertheless, the instances, in which mitosis was mentioned, were in accordance with the results of this study[2, 10, 28, 34]. according to the positive significant correlation between eosinophils count and mitoses (p=0.004), it is suggested that the higher eosinophils count, the higher the proliferative capability of tugse that necessitate awareness and regular follow up. previously, tugse was suggested to represent an oral counterpart of cutaneous cd30+ lpd[12]. in this context, alobeid et al.[17] reported 3 cases of tugse lesions that were strongly positive for cd30 and showed a monoclonality, suggesting tusge to represent a heterogeneous category of disorders including cd30+ lpd[17]. furthermore, a proposal of mucosal cd30+ lpd was aroused again through a study of 4 cases of oral ulcerative lesions that supposed to represent tugse, where all cases showed cd30 positivity with the presence of t-cell monoclonality[18]. on the other hand, tugse was considered as a reactive oral lesion in a study of 12 cases, but might harbor a dominant clonal t-cell population; cd30 expression was evident only in 5 cases[21]. similarly, a reported case of recurrent cd30+ tugse, a reactive nature was suggested[35]. later on, a reactive nature of tugse was also postulated[36, 37]. in rejecting the concept that tugse represented the oral counterpart of primary cutaneous cd30+ lpd, a study of 37 cases of tugse showed no specific relation between the presence of cd30+ large atypical mononuclear cells and the presence of t-cell monoclonality[28]. in their study, fonseca et al. stated that those lesions behaved in a benign and reactive way [24]. in the current study, the expression of cd30 was heterogeneous with focal and nonspecific staining pattern. positivity was exhibited mainly by small round lymphocytes with presence of some cd30+ large atypical cells indicating that almost all lesions of tugse in this study were benign and reactive; but, it is worth to mention that in spite of designating tusge as a benign and reactive ulcerative lesion of oral mucosa, a rare subset of tugse may show worrisome immunohistochemical features (presence of high level of cd30 expression as in 3 cases in this study, >75%) and molecular findings (evidence of monoclonality)[17, 18, 21, 28]; regarding the latter, it is suggested that the continuous irritant insult could eventually affect cellular differentiation from polyclonal toward oligoclonal then monoclonal that is proposed to be similar, in terms of pathogenesis, to gastric mucosa-associated lymphoid tissue lymphoma (maltoma) and immunoproliferative small intestinal disease (ipsid)[38]. regarding the expression of cd30 marker, the results of this study were in accordance with many other studies in postulating tugse to be a benign and reactive ulcerative lesion of the oral mucosa[35-37] that may show some worrisome features such as high level of cd30 positivity and t-cell monoclonality[21, 24, 28], but disagree with those who supposed tugse to represent an oral counterpart of cutaneous cd30+ lpd or primary mucosal cd30+ lpd[12, 17, 18]. all cases showed cd68 positive histiocytes with varying expression from one case to another. these results were in accordance with the vast majority of previous series and case reports of tugse (table 3), but disagreed with alobeid et al.[17] who stated negative cd68 expression in their 3 cases reported. it is suggested that tugse is typically infiltrated by histiocytic macrophages (cd68+) which represent one of the most dominant cellular infiltrate of chronic inflammatory responses; so that, cd68 marker has to be considered as a diagnostic criterion for tugse. rather than being a simple wound that, for one reason or another, fails to heal, tguse is supposed to represent a specific oral chronic lesion with peculiar features, since a subset of tugse may be presented with unusual and alarming signs. regarding tgf-β1 expression, the only study that assessed the expression of the aforementioned tgf was carried out by elovic et al.[22] who stated that eosinophils infiltrating tugse lesions expressed little or no tgf-α and tgf-β1 and the delayed healing of tugse was attributed to such lack of expression; however, other cells such as epithelial, mononuclear and fibroblasts did express these cytokines in their study[22]. the present study is the second study in evaluation of tgf-β1 in tugse lesions where all cases were highly positive. anyhow, in contradiction with the hypothesis of elovic et al.[22], it is suggested that delayed healing of tugse may be imputed to reasons other than the lack of tgf-β1 expression by eosinophils. therefore, it is not fair to neglect tgf-β1 expression by other cellular components in tugse. j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 51 table 2: large series of cases of tugse. author number of cases mean age (range) sex (m/f) size (mean) duration previous trauma bhaskar and lilly [2] 7 37 (20-59) 2.5/1 not stated 14–63 days none elzay [8] 41 58 (14-92) 1/1 not stated 3–120 days 21 cases doyle et al. [27] 15 62 (42-77) 1.1/1 0.35 cm (1.8) 2 weeks-6 months 5 cases el-mofty et al. [10] 38 57 (6-88) 1/1.5 0.56.5 cm (2.2) weeks to months 7 cases regezi et al. [25] 8 59 (10-87) 1/3 not stated 2 weeks-6 months not stated elovic et al. [22] 12 62.2 (38-85) 1/1.6 not stated 2 weeks8 months 1 case hirshberg et al. [21] 12 49.2 (14-87) 1/1 0.3-1.5cm (0.9) days to 1 year 4 cases salisbury et al. [28] 37 58.1 (11-91) 1/2 not stated days to years not stated abdullah [29] 17 40 (16-70) 1/1.1 0.252 cm (0.5) 1 month2 years not stated fonseca et al. [24] 19 58.6 (35-84) 1.3/1 not stated 2 48 months 7 cases shen et al. [30] 34 49 (8-80) 1.8/1 not stated not stated not stated kaplan et al. [31] 16 60 1.5/1 not stated not stated 4 cases jayalakshmy et al. [32] 6 60.3(5377) 1/5 0.61.5 cm (1.08) not stated 4 cases phoorisriphong et al. [33] 8 59.1 (10-86) 3/1 not stated not stated not stated vargo et al. [20] 6 60.5 (53-74) 1/5 not stated not stated 2 cases current study 21 53 (20-72) 1/2.5 0.2-1.56 cm (1.03) 1 month1 year 4 cases table 3: studies and case reports examining the expression of cd68 in tugse. author number of cases cd68 expression comments regezi et al. [25] 8 +ve the large round cells expressed the macrophage marker, cd68. el-mofty et al. [10] 9 of 38 +ve cd68+ histiocytic cells were less common than t-cell markers. ficarra et al. [12] 1 -ve the infiltrate composed of t-cells with cd1a+ dendritic cells. horie et al. [34] 1 +ve focal expression for cd68. alobeid et al. [17] 3 -ve the neoplastic cells were negative for cd68 protein. hirshberg et al. [21] 12 10 +ve cd68+ cells were found in most cases. segura and pujol. [36] 1 +ve abundant cd68+ histiocytes throughout the lesion. boffano et al. [37] 1 +ve diffuse positivity of the histiocytes for cd68 was demonstrated. vasconcelos et al. [39] 1 +ve diffuse immunoreactivity for cd68 in the inflammatory cells, defining these cells as macrophages and not as neoplastic cells. bortoluzzi et al. [40] 1 +ve diffuse positive pattern of cd68. brasileiro et al. [19] 1 +ve cd68 evidenced numerous reactive histiocytes. chatzistamou et al. [41] 1 +ve many cells were positive for cd68. fonseca et al. 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2011. 2892 p. j bagh college dentistry vol. 30(4), december 2018 clinicopathological and 53 39 vasconcelos mg, souza lbd, silveira éjdd, medeiros amcd, carvalho mdv, queiroz lmg. eosinophilic ulcer of the lateral tongue: case report. rsbo (online). 2011;8:459-63. 40 bortoluzzi mc, passador-santos f, capella dl, manfro g, nodari rj, jr., presta aa. eosinophilic ulcer of oral mucosa: a case report. annali di stomatologia. 2012;3(1):11-3. 41 chatzistamou i, doussis-anagnostopoulou i, georgiou g, gkilas h, prodromidis g, andrikopoulou m, et al. traumatic ulcerative granuloma with stromal eosinophilia: report of a case and literature review. journal of oral and maxillofacial surgery: official journal of the american association of oral and maxillofacial surgeons. 2012;70(2):349-53. maisam final.doc j bagh college dentistry vol. 26(2), june 2014 early detection of oral and maxillofacial surgery and periodontics 116 early detection of periodontitis among young adult cigarette smokers and non-smokers using cone beam computed tomography maisam a. kadhem, b.d.s. (1) basima gh. ali, b.d.s., m.sc. (2) shifa h. al-naimi, b.d.s., h.d.d., m.sc. (3) abstract background: periodontitis is an inflammatory disease that affects the supporting tissues of the teeth; smoking is an important risk factor for periodontitis induces alveolar bone loss and cause an imbalance between bone resorption and bone deposition. the purpose of this study is to detect and compare the presence of incipient periodontitis among young smokers and non-smokers by measuring the distance between cement-enamel junction and alveolar crest (cej-ac) using cone beam computed tomography (cbct). material and methods: the total sample composed of fifty two participants, thirty one smokers and twenty one nonsmokers (age range 14-22 years). periodontal parameters: plaque index (pli), gingival index (gi) were recorded for all teeth except the third molar while the radiographic analysis using cbct was recorded on the ramfjord teeth, the unit of measurement was from cement-enamel junction to alveolar crest distance (cej-ac distance) per site in millimeters. results: the results obtained were a non significant difference for pli, a significant difference of mean of gi between young smokers and non smokers. there was a highly significant difference in the general mean of cej-ac distance between both groups. there was a significant difference between maxillary and mandibular teeth, a non significant difference between right and left sides among young smokers and non smokers. conclusion: the cbct device plays an important role in detection the incipient form of periodontitis among young smokers and non-smokers, so we concluded that there is a highly significant difference in the general mean cej-ac distance between young smokers and non smokers with increase distance in the maxillary teeth than that in the mandibular teeth. key words: incipient periodontitis, cigarette smokers, cbct. (j bagh coll dentistry 2014; 26(2): 116-121). introduction periodontal diseases are bacterial infections of the gingiva, bone and attachment fibers that support the teeth and hold them in the jaw. the main cause of the diseases is bacterial plaque, a sticky, microbial film that constantly forms on teeth. (1) periodontal disease occurs primarily due to bacteria within the gingival crevice or the periodontal pockets, it may be affected indirectly by many other risk factors occurring changes in the vascular system, severity of inflammatory reactions and host immunological responses. (2,3)a clear correlation between the presence of plaque and gingivitis has been established, it doesn't necessary that all individuals with gingivitis will progress to develop periodontitis even in the presence of putative pathogens. (4) chronic periodontitis similarly can have its initiation during adolescence and can later in life lead to tooth loss and associated systemic disease. the incipient form of chronic periodontitis and aggressive periodontitis can be treated successfully by appropriate intervention (5). (1) master student, department of periodontics, college of dentistry, baghdad university. (2) assistant professor, department of periodontics, college of dentistry, baghdad university. (3) ministry of health, department of radiology, al-karkh general hospital. the incipient periodontitis is often not diagnosed by clinicians for the lack of understanding of the disease and sufficient diagnostic acumens. when the disease is diagnosed, is it chronic or aggressive periodontitis, the tissue damage may be evident. chronic periodontitis is generally slowly progression of periodontal disease that at any stage may undergo an exacerbation resulting in additional loss of attachment apparatus (6). smoking was a major factor associated with periodontal destruction in a group of young jordanian adult’s case study (7). the effects of smoking on periodontal tissue depend on the number of the cigarette smoked daily and the duration of the habit (8). dental studies have reported that smokers have a greater amount of plaque and calculus deposits than their non-smoking counterparts of comparable age, and the quantity of calculus is correlated with the frequency of smoking (9,10) the effects of smoking cessation and the use of daily interdental cleaning have not found to be an effective tool to change individual habits. in the future, motivational interviewing may be a more effective method to achieve a behaviour change if an extended education of dental j bagh college dentistry vol. 26(2), june 2014 early detection of oral and maxillofacial surgery and periodontics 117 hygienists within this area will be implemented (11). smoking even one cigarette has been suggested to have the potential to cause a decrease in gingival blood flow. (12) such small but repeated vasoconstrictive attacks and impairment of revascularization due to cigarette smoking may contribute to disruption of immune response and delay in the healing response, leading to an increased risk of periodontal disease. (13) multiple cross-sectional and longitudinal studies have demonstrated that pocket depth, attachment loss, and alveolar bone loss are more prevalent and severe in patients who smoke compared with nonsmokers.(14,15,16) in vitro studies of the effects of tobacco products on neutrophils have shown detrimental effects on cell movement and the oxidative burst. the immune and inflammatory responses are critical to understanding the pathogenesis of periodontal diseases and they are orchestrated by a number of host-related factors, either intrinsic or induced. (17) the mechanisms by which smoking could influence the host control of bacteria included the effects of carbon monoxide enhancing growth of bacteria, which in turn provide growth factors for anaerobes, and damaging cells involved in the protection of the periodontal environment such as nutrophils, which could be affected by the formation of advanced glycation endproducts (agep) by smoking, which is either internal or external in origin.(18) internal sources include certain systemic conditions such as diabetes, alzheimers disease, and uremia. (19) external agep are produced by the combustion of nicotine in cigarette smoke. alveolar bone is one of the tissues that is most affected by the progression of periodontal disease. the mechanism of alveolar bone damage produced by smoking is related to the component of tobacco and nicotine metabolites which may act directly as local irritants on the gingival and alveolar bone or indirect because these components are absorbed in the lung which affects the cellular host defense or bone turnover. another potential mechanism of bone loss in smokers may be the suppression of osteoprotegrin (opg) production and a change in the receptor activator of nuclear factor–kappa ligand (rankl) and opg ratio (rankl/ opg ratio). (20, 21) computed tomography (ct) is a radiographic technique that using a rotating fan shaped beam to image a thin slice of the patient. the pursuit of 3d information has led to exploring the value of ct for the assessment of the alveolar bone height. (22) the usefulness of ct in analyzing 3d structure of alveolar bony defects in patient with periodontal disease was evaluated. the results showed that differences between ct film and actual reading (surgical) were negligible. it was concluded that the application of ct might be useful for analyzing 3d structure and diagnosis of alveolar bone defect. (23) by the end of the twentieth century and the beginning of the twenty-first, it has become apparent that cbct imaging may indeed be the next major advancement in dentoalveolar imaging, providing true 3d imaging at a lower cost than conventional ct, with radiation risks similar to current methods of intraoral imaging, including panoramic and full mouth radiographic examination. (24) the cbct units have been developed specifically for oral and maxillofacial imaging. (25,26) the technique of cbct could measure exactly the bone loss in term of distance between cej-ac. cbct would allow an accurate assessment of bone levels and accurate description of infrabony defects. this study could underline the fact that cbct allows a very precise assessment of bone craters and furcation involvements. considering advantages, limitations, risks, and machinespecific variations of cbct, showed the accuracy and potential applicability of a specific cbct for radiological periodontal diagnosis.(27) the disadvantages of cbct imaging are poor soft tissue contrast and artifacts. poor soft tissue contrast is not usually a problem in dental and maxillofacial imaging, because the main subjects of interest are generally mineralized tissues, i.e. teeth and bones.(28) the use of cbct in clinical practice has a number of potential advantages over conventional tomography, such as easier image acquisition, greater image accuracy, lower effective radiation dose, faster scan time, and greater cost-effectiveness (26,28,29). data from the craniofacial region are often collected at higher resolution in the axial plane than those from conventional ct systems. materials and methods fifty two male subjects were enrolled in this study, with an age range (14-22) year male. all subjects were drawn from patients attending the special health center for dentistry in al-sadar city. those subjects were divided into two groups:1-smokers group: thirty one subjects regularly smoked at least 10 cigarettes on average per day (30) for the last two years (16) with an age range (14-22) years. 2-non-smokers group: twenty one subjects didn’t present any history of smoking with an age range (14-22) years. the exclusive criteria include the following:1past j bagh college dentistry vol. 26(2), june 2014 early detection of oral and maxillofacial surgery and periodontics 118 smokers. 2all subjects with any systemic disease. 3all subjects with medication affecting on periodontal health for at least three months ago (anti inflammatory or antimicrobial therapy). 4 all subjects who smoke other than cigarette. the collected data in clinical examination were pli and gi and all present teeth included except the third molars, while in radiographical examination the teeth included is ramfjord teeth. the teeth numbering according to the fdi system are (16,21,24,36,41,44). (31) the system we use it in our study is kodak 9500 cbct. this is the first system that has been installed in iraq in the special health center of dentistry in al-sadar city in the december 2012. cbct utilizes a cone shaped source of radiation and an area detector and that it acquires a full volume of images in a single rotation with no need for patient movement. by using the cbct system accompanying software, any number of diagnostic images can be generated. on the coronal view we measured the cej-ac distance in ramfjord teeth under supervision of special radiologist (the bone loss occurred when the distance was more than 1.5 mm). the measurement was down by linear measurement of the cej-ac distance by choosing the ruler option of the kodak software program. the slice width used in the anterior teeth was equal to 19.5mm while in the posterior teeth was equal to 2.1mm. an extra-oral 3d radiograph was operated at 90kv and 10ma with an exposure time 10.8 seconds. results it was clearly shown that the mean of plaque index were elevated in smokers compared with non-smokers, the mean of gi of non smokers group was higher than that of smokers group. (table 1) it was obviously clear that the general mean of cej-ac distance was elevated in smokers group 2.711 ± 0.463 compared with non-smokers group 0.968 ± 0.345. as a result of a higher levels of cej-ac distance in young smokers than that of non smokers, when we compared cej-ac distance in the maxillary, mandibular, right and left sides between smokers and non smokers we found that the distance in the maxillary and mandibular teeth in smokers is higher than that of non smokers with highly significant differences. the cej-ac distance in the right and left sides is highly significant differences between smokers and non smokers with higher levels in smokers (table2). the result of this study is the cej-ac distance in the max teeth is higher than that of the mandibular teeth with a highly significant difference among smokers and a significant difference among non-smokers. a non significant difference in the level of the alveolar bone loss was recorded between right and left sides in smokers and non-smokers (table 3). in smokers there was a non significant negative correlation between the mean of pli and cej-ac distance while, in non-smokers there was a significant positive correlation. it appears that there was a non significant positive correlation between the mild gingivitis and cej-ac distance in both groups while there was a non significant negative correlation between the moderate gingivitis and cej-ac distance (table 4). table 1: descriptive statistics and inter group comparison of means of plaque index and gingival index between smokers and nonsmokers. group mean ± sd t-test p-value sig pli smokers 1.325 0.471 1.446 0.154 ns non-smokers 1.138 0.429 gi smokers 0.974 0.288 2.896 0.006 s non-smokers 1.228 0.341 j bagh college dentistry vol. 26(2), june 2014 early detection of oral and maxillofacial surgery and periodontics 119 table 2: descriptive statistics and inter group comparison of means of cej-ac distance of smokers and nonsmokers. group mean ± sd t-test p-value sig smokers 2.711 0.463 14.687 0.000 hs non-smokers 0.968 0.345 max. teeth smokers 3.0097 0.544 14.087 0.000 hs max. teeth non-smokers 1.1094 0.353 mand. teeth smokers 2.413 0.481 12.436 0.000 hs mand. teeth non-smokers 0.834 0.398 right smokers 2.6555 0.463 12.511 0.000 hs right non-smokers 1.0595 0.433 left smokers 2.768 0.506 14.981 0.000 hs left non-smokers 0.885 0.332 table 3: descriptive statistics and intra group comparison of means of cej-ac distance in maxillary and mandibular teeth, right and left side. table 4: the coefficient of person correlation (r) of the level of cej-ac distance with plaque index, mild and moderate gingivitis among smokers and non-smokers and their level of significant differences group r p-value sig plaque index smokers -0.035 0.850 ns non-smokers 0.530 0.013 s mild gingivitis smokers 0.22 0.431 ns non-smokers 0.999 0.031 ns moderate gingivitis smokers 0.04 0.880 ns nonsmokers 0.309 0.288 ns discussion the mechanism of alveolar bone damage produced by smoking is related to the components of tobacco and nicotine metabolites which may act directly as local irritants on the gingival and alveolar bone or systemically because these components are absorbed in the lung, which affects the cellular host defense or bone turnover. nicotine can suppress the proliferation of cultured osteoblasts while stimulating osteoblast alkaline phosphatase activity. (32) recently, some in vitro studies provided other possible intimate mechanisms by which smoking may affect bone metabolism. rosa et al. (32) reported that nicotine increased the secretion of il-6 and tnf-α in osteoblasts and also nicotin increased the production of tissue-type plasminogen activator, pge2 and mmp, thereby tipping the balance between bone matrix formation and resorption toward the latter process. al qutub (33) observed a higher mean alveolar bone loss in the max. teeth than the mand. in smokers and non smokers. bergstrom (34) found that the alveolar bone loss was more prominent in the maxillary teeth than the mandibular teeth in the form of percentage. the possible explanation could be that the cortical bone in maxilla is thinner, less dense and more rigid than that in mandible; therefore, the maxillary alveolar bone undergoes resorption more readily than that of the mandible. in non smokers, the positive correlation between pli and bone loss suggest that, the bacterial plaque play a major and an important role in alveolar bone loss. since this study conducted on young age group of mean ± sd t-test p-value sig smokers max. 3.0097 0.544 4.576 0.000 hs mand. 2.4129 0.481 right 2.655 0.463 0.918 0.363 ns left 2.7677 0.5061 non-smokers max 1.109 0.353 2.375 0.022 s mand 0.834 0.398 right 1.0595 0.433 1.466 0.15 ns left 0.8849 0.332 j bagh college dentistry vol. 26(2), june 2014 early detection of oral and maxillofacial surgery and periodontics 120 patient, longer time using tobacco could have a stronger effect on the bone destruction. sch tzle et al. (35) demonstrated that, in smokers and non smokers younger than 30 years of age, there was little or no difference in the standard of oral hygiene, so the bone loss independent of plaque levels and severity of gingivitis. in conclusion the cbct reveal that the prevalence of incipient bone loss among smokers was 100% while it was 4.76% among nonsmokers. there was a highly significant difference in the mean cej-ac distance between smokers and non smokers with higher mean cej-ac distance in smokers than non-smokers group. a significant difference in the amount of bone loss between maxillary and mandibular teeth for both groups was found. references 1. american academy of periodontology. diabetes and periodontal disease, a two way relationship. suite 800 737 north michigan avenue chicago. illinois, 2004; 60: 2611-2690. 2. kinane df. causation and pathogenesis of periodontal disease periodontol 2000 2001; 25:8-20. 3. nunn me. understanding the etiology of periodontitis: an overview of periodontal risk factors. periodontol 2000 2003; 32:11-23. 4. kinane df, shiba h, hart tc. the genetic basis of periodontitis. periodontol 2000 2005; 39: 91–117. 5. sood m. diagnosis of periodontal disease in adolescents. j innovative dentistry 2011; 1(1):1-4. 6. lima fr, cesar-neto jb, lima dr, kerbauy wd, nogueira-filho gr. smoking enhances bone loss in anterior teeth in a brazilian population: a retrospective cross-sectional study. braz oral res 2008; 22(4): 32833. 7. al-wahadni a, liden gj. the effects of cigarette smoking on the periodontal condition of young jordanian adults. j clin periodontol 2003; 30: 132-7. 8. calcina g, ramon j, echeverria j. effects of smoking on periodontal tissue. j clin periodontol 2002; 29: 771-6. 9. muller h-p, stadermann s, heinecke a. longitudinal association between plaque and gingival bleeding in smokers and non-smokers. j clin periodontol 2002; 29: 287-94. 10. nwhator so. periodontal disease in smokers: a study of factory workers in lagos state [dissertation]. nigeria, faculty of dental surgery, national postgraduate medical college of nigeria, may, 2005. 11. shamani s, jansson l. oral hygiene behaviour change during the nonsurgical periodontal treatment phase. the open dentistry j 2012; 6: 190-6. 12. mirbod sm, ahing si, pruthi vk. immunohistochemical study of vestibular gingival blood vessel density and internal circumference in smokers and non-smokers. j periodontol 2001; 36: 1318-23. 13. ojima m, hanioka t, tanaka k, inoshita e, aoyama h. relationship between smoking status and periodontal conditions: findings from national databases in japan. j periodont res 2006; 41: 573–9. 14. johnson gk, slach na. impact of tobacco use on periodontal status. j dent educ 2001; 65: 313. 15. luzzi li, greghi sl, passanezi e, passanezi ac, lauris jr. evaluation of clinical periodontal conditions in smokers and non-smokers. j appl oral sci 2007; 15(6): 512-7. 16. al-tayeb d. the effects of smoking on the periodontal conditions of young adult saudi population. egyptian dental j 2008; 54(3): 1-11. 17. taubman ma, valverde p, han x, kawai t. immune response: the key to bone resorption in periodontal disease. j periodontol 2005; 76: 2033-41. 18. eggert fm, mcleod mh, flowderdew g. effects of smoking and treatment status on periodontal bacteria: evidence that smoking influences control of periodontal bacteria at the mucosal surface of the gingival crevice. j periodontol 2001; 72: 1210-20. 19. yonekura h, yamamoto y, sakurai s, watanabe i, yamamoto h. roles of the receptor for advanced glycation endproducts in diabetes induced vascular injury. j pharmacol sci 2005; 97: 305-311. 20. lappin df, sherrabeh s, jenkins wm, macpherson lm. effect of smoking on serum rankl and opg in sex, age and clinically matched supportive-therapy periodontitis patients. j clin periodontol 2007; 34: 271-7. 21. cesar-neto jb, duarte pm, de oliveira mc, tambeli ch, sallum ea, nociti fh. smoking modulates interleukin-6: interleukin–10 and rankl: osteoprotegerin ratios in the periodontal tissues. j periodontal res 2007; 42:184-91. 22. ander mol. imaging methods in periodontology. periodontology 2000 2004; 34: 34-48. 23. asif s. comparative study of direct digital and conventional intraoral bitwing radiography in detecting alveolar bone loss. a master thesis, the rajiv gandhi university of health sciences, karnataka, bangalore, 2006. 24. ludlow jb, davies-ludlow le, brooks sl, et al. dosimetry of 3 cbct devices for oral and maxillofacial radiology: cb mercuray, new tom 3g and 1cat. dentomaxillofac radiol 2006; 35: 219-26. 25. robinson s, suomalainen a, kortesniemi m. μ-ct. eur j radiol 2005; 56:185-191. 26. scarfe wc, farman ag. what is cone-beam ct and how does it work? dent clin n am 2008; 52: 707–30. 27. fleiner j, hannig c, schulze d, stricker a, jacobsr. digital method for quantification of circumferential periodontal bone level using cone beam ct. clin oral invest 2013; 17: 389–396. (ivsl). 28. scarfe wc, farman ag, sukovic p. clinical applications of cone-beam computed tomography in dental practice. j can dent assoc 2006; 72: 75–80. 29. white sc, pharoah mj. the evolution and application of dental maxillofacial imaging modalities. dent clin north am 2008; 52: 689-705. 30. scabbia a, cho ks, singurdsson tj, kim ck, trombelli l. cigarette smoking negatively affects healing following flab debridement surgery. j periodontol 2000; 72: 43-9. 31. shariatmadar ar, kharazi fmj, mousavi v. comparison of partialand full-mouth examination in j bagh college dentistry vol. 26(2), june 2014 early detection of oral and maxillofacial surgery and periodontics 121 periodontal assessment among untreated patients. j dentistry 2009; 6(3): 116-20. 32. rosa mr, luca gq, lucas on. cigarette smoking and alveolar bone in young adults: a study using digitized radiographic. j periodontal 2008; 79:232-44. 33. al-qutub mn. pattern of alveolar bone loss among smokers and non smokers with periodontitis. j pak dent assoc 2011; 20(2): 83-8. 34. bergstrom j. influence of tobacco smoking on periodontal bone height. long term observations and a hypothesis. j clin periodontol 2004; 31: 260-6. 35. schätzle m, löe h, ramseier ca, bürgin w et al. clinical course of chronic periodontitis: effect of lifelong light smoking (20 years) on loss of attachment and teeth. j investigative and clinical dentistry 2010; 1: 8-15. 16. mohammed f.doc j bagh college dentistry vol. 27(4), december 2015 the effect of oral and maxillofacial surgery and periodontics 101 the effect of platelet-rich plasma on osseointegration period of dental implants mahammed w. al-gailani, b.d.s (1) thair abdul-lateef, b.d.s., h.d.d., f.i.b.m.s. (2) abstract background: the preparation of platelet-rich plasma (prp) is minimally invasive way, simple, low cost to obtain natural autologous growth factors and is now being widely used in different fields of medicine for its ability to increase the regeneration potential of tissue. the aim of this study was to investigate the effect of local application of autologous prp gel on acceleration rate of osseointegration period by clinical assessment accomplished by determining the changes in implant stability during 3 months healing period using resonance frequency analysis (rfa). materials and methods: a total of 28 dental implants were inserted in edentulous maxillae or mandibles of 13 patients using a split mouth design, i.e. each patient was received at least two dental implants at the same session, one implant was implanted in association with prp which was placed locally in one site, to serve as prp group, and the other implant was placed without prp, to serve as a control group. both groups were followed with repeated implant stability measurement by means of resonance frequency analysis at different time intervals (at the time of implant placement, 8th week, and 12th week postoperatively). results: there was no obvious statistically significant difference in mean isq between prp and control groups (p > 0.05) at baseline, 8 weeks, and 12 weeks postoperatively. conclusions: within the limitations of the present study, no appreciable clinical effect was observed to accelerate the rate of osseointegration of sandblasted acid-etched endosseous dental implants when using topical application of autologous prp gel into the prepared drill holes. key words: platelet rich plasma, osseointegration, stability, dental implant. (j bagh coll dentistry 2015; 27(4):101-106). introduction the development of dental implants to replace missing teeth with the demand by patients to decrease the osseointegration period following implant placement have led to a major works by researchers to enhance a quality of biomaterials and to develop implant surfaces with improved microscopic and macroscopic structures that allow induction of osseointegration (1). in regard to the classic treatment protocol proposed by branemark, three months of tissue healing after tooth removal, following three to six months of load-free interval after implant installationt are necessary for bone integration. due to the great success rate of dental implants, this consuming period may lead to one year of reduced life quality, which can influence the judgment for dental implant rehabilitation (2). some researchers have attempted to shorten osteogeneration period by employing growth factors. the best source of autologous growth factors in the body is platelets. currently, they are recognized that platelets have many functions further than their role of hemostasis. platelets have important growth factors that are responsible for increasing cell mitosis, initiating vascular in (1) master student. department of oral and maxillofacial surgery. college of dentistry, university of baghdad. (2) assistant professor. department of oral and maxillofacial surgery. college of dentistry, university of baghdad. growth, inducing cell differentiation, increasing collagen production, and recruiting additional cells to the area of wound (3). the growth factors are present in the αgranules of platelets and released at the site of wound during activation. these growth factors are: platelet-derived growth factor (pdgf), transforming growth factor β (tgf-β), plateletderived epidermal growth factor (pdegf), vascular endothelial growth factor (vegf), insulin-like growth factor-1(igf-1), platelet factor-4 (4). clotting cascade can activate platelets, which begin releasing their growth factors immediately. they secrete 70% of their stored growth factors within 10 minutes and close to 100% within the first hour, then they produce additional amounts of growth factors for about 8 days until they are depleted and die (5,6). among factors which can activate platelets are: adp, thrombin, thromboxanes, epinephrine, collagen, and shear stress (7-9). marx et, al., first introduced the technique of autologous platelet concentration in 1998 to create the first platelet-rich plasma (prp) for application in dental surgery (1,10). prp is a high concentration of autologous platelets within a small quantity of autologous plasma (11). the clinical application of prp was expanded to other fields, including cosmetic medicine, cardiac surgery, oral and maxillofacial j bagh college dentistry vol. 27(4), december 2015 the effect of oral and maxillofacial surgery and periodontics 102 surgery, ophthalmology, sports medicine, orthopedic surgery, and plastic surgery. it would seem intuitive that a higher platelet count would yield more growth factors and better clinically results, however, this has not yet been determined (12). weibrich et, al., in 2004 required plasma preparations to have a platelet concentration of 1000 × l03/µl to be the considered therapeutic platelet rich plasma (13). marx et, al., in 1998 demonstrated an increase in bone density six months after using platelet concentrate with platelet concentrations 595,000– 1,100,000 platelets/µl (10). graziani et, al., in 2006 showed that optimal results were observed when platelet concentration increased 2.5 times from basic platelet count. higher concentrations (maximum 5.5 x concentration) reduced proliferation and osteoblast function (14). many studies have found that prp induces and accelerates soft tissue regeneration and bone repair, the preparation of prp can be applied to metal of dental implant surface and could create a new dynamic surface that might potentially show biologic reaction. this protein stratum consists of a fibrin mesh and growth factors that covers the implant surface and makes the initial interactions of surrounding tissues with implant surface. it also enhances cellular proliferation, attachment, differentiation, and bone matrix deposition (15). anitua showed that osseointegration of implants was improved by covering the implant surface with prp, rich in growth factors, before installation into the bone (16). similarly, nikolidakis and co-workers, found a significant result of bone formation around titanium implants bioactivated with prp solution (16, 17), but garcia et, al., (2010), observed that prp did not enhance bone apposition to acid etched implants (5, 18). the aim of the present study was to investigate the effect of local application of autologous prp gel on acceleration rate of osseointegration period by clinical assessment accomplished by determining the changes in implant stability during 3 months healing period using resonance frequency analysis (rfa).the initial euphoria about the use of prp for improving bone formation and subsequent controversial results suggest the need for more studies on this topic. materials and methods subjects: thirteen patients, 7 women and 6 men with the mean age of 42 years (22-60) were opted in this study whom fulfilled the inclusion and exclusion criteria. each patient was received at least two dental implants at the same session, one implant was placed in association with prp in one site (to serve as prp group) and the other implant was placed without prp (to serve as a control group) in the same edentulous region or in a bilaterally symmetric to the median line (split-mouth design) provided by the two implant beds have the same range of bone quality (density). implant systems: a total of 28 titanium screw-shaped implants (implantium® / dentium® / seoul / korea) and (maxicell® / nucleoss®/ turkey) with a surface modified by tio2-large grit sandblasting and acid etching surface were utilized in the study. the diameter of ø3.4 mm, ø3.8 mm ø4.3 mm or ø4.8 mm and a length of 8 mm, 10 mm, 12 mm or 14 mm were placed in the patients̕ jaws, who are selected in the present study. pre-surgical examination: the patients were pre-surgically evaluated for any conditions that are implicated for dental implant therapy and platelet function. preoprative standardized interactive ct scans were taken for registering bone density at the implant sites and also estimation of proper implants length and diameter according to bone width and length measurements and evaluation of proximity to the vital structures. preparation of prp: platelet separation and concentration starts before the implantation procedure with an aseptic and minimally traumatic phlebotomy technique. nine milliliters of venous blood was collected from the veins of antecubital fossa in edta (k3) vacuum tube using 10 ml syringe. eight times gently rock the tube back and forth to incorporate the whole blood and anticoagulant, at this stage we can take blood sample for complete blood count test. using low speed fixed rotor laboratory centrifuge (80-1, china), the blood tube was placed in the centrifuge hole and another tube was placed opposite to the first one (with the same weight) containing normal saline for balancing centrifugation. first spin (separation spin) was begun at 1200 rpm (160 g) for 10 minutes, which separates the red blood cells (red lower fraction) from the rest of the whole blood, i.e. white blood cells, platelets, and plasma (upper straw-yellow turbid fraction) (figure 1). j bagh college dentistry vol. 27(4), december 2015 the effect of oral and maxillofacial surgery and periodontics 103 figure (1): the result after the 1st spin. the whole upper fraction was pipetted by 1001000 µl micro-pipette and transferred to a glass plain tube. the remaining red blood cells fraction was discarded. now, the aspirated fluid was submitted to a second spin (concentration spin) of about 3200 rpm (1200 g) for 10 minutes. the second spin separates and compacts the platelets, white blood cells, and a small number of residual red blood cells (precipitate at the bottom of the tube) from the plasma, which is clear straw yellow color (platelet poor plasma (ppp)) (figure. 2). by using the same micro-pipette, ppp was drawn off and discarded, leaving approximately 1 ml of the fluid (figure. 3). figure (2): the result after the 2nd spin. figure (3): the remaining of ppp and the precipitated blood cells before resuspension. after that, the remaining fluid was resuspended before clinical use. this is the prp. now the prp was pipetted and transferred into eppendorf tube and stored at room temperature until implant procedure start (figure 4). platelets were counted using a cell dyn emerald hematology analyzer and ranged between 800,000 to > 1500,000/ µl. figure (4): prp solution in eppendorf tube. during implant surgery, prp gelation was induced by adding 10% calcium gluconate to the prp with volume ratio of 1:10 using 10-100 µl micropipette. this requires agitation of the tube every one minute and waiting between 5-15 minutes (figure 5). the role of calcium is to nullify the effect of anticoagulant and to restore the physiological function of coagulation process lead to the formation of thrombin, which causes activation of platelets. figure (5): activated prp gel. implant surgical procedure: the surgery was started with locally anesthetizing the area to be implanted. an extensive flap design was raised. the implant sites were exposed and prepared using conventional drilling procedure in sequence until reaching a desired size. before dental implants placement into their drill holes, prp gel was gently introduced into one site (prp implant) and the other site left without prp (control implant site) (figure 6). after the implants had been inserted in their beds, primary implant stability for both implants (prp and control implants) by osstell isq through screwing the smart peg into the body of j bagh college dentistry vol. 27(4), december 2015 the effect of oral and maxillofacial surgery and periodontics 104 implant and two readings of the isq values were recorded; in a bucco-lingual and in mesio-distal directions. figure (6): application of prp into the one implant site. 2nd stage surgery and follow up visits: the first visit of follow up started 8 weeks postoperatively. local anesthesia was given using an infiltration technique. with the use of tissue punch drill, both prp implants and control implants were uncovered and implants secondary stability were measured in the same manner of primary stability measurement. healing abutments were placed according to the size of implants and gingival thickness to gain access for subsequent 12th week measurement. statistical analysis: data were translated into a computerized database structure. statistical analyses were done using spss version 21 computer software. because we had two isq measurements for each implant at each time point (mesio-distal and bucco-lingual measurement), average of the two isq measurements was used in this results. the independent samples t-test was used to test the statistical significance of difference in mean between the two groups. results all the implants were successfully healed over the three months follow-up period with a survival rate of 100%. one patient reported pain associated with the peri-implant suppuration on probing around one control implant but the lesion treated and resolved without further incidence. resonance frequency analysis difference between the two groups: there was no obvious or statistically significant difference in mean isq between the two groups at surgery (p = 0.35), the mean and standard deviation values of rfa at placement (primary stability) were 70.46 ± 7.32 for the control implants and 73.21 ± 8.13 for the prp implants. eight weeks postoperatively, the mean and standard deviation values of isq were 69.57 ± 10.69 at the control sites and 73.81 ± 5.90 at the prp sites. the difference in mean isq was greater in the prp group by 3.61 isq units compared to control group this is considered as non significant (p = 0.27) and evaluated as a moderate effect (cohen’s d= 0.42). at 12 months follow-up period, the mean and standard deviation values of rfa were 71.96 ± 8.51 for control implants and 74.32 ± 5.44 for prp implants. the difference in mean isq units after 12 weeks of surgery was also non significant between the prp group compared to control group (p = 0.39) and the treatment effect was evaluated as a moderate effect (cohen’s d = 0.33) (figure 7). figure (7): the mean isq of prp and control implants within the three successive periods. discussion prp gel is a normal autogenous blood clot that contains a highly concentrated number of platelets and native concentration of fibrin. it is minimally invasive way, simple, low cost to obtain natural autologous growth factors. because it is the patient's own blood, it is free of transmissible diseases and cannot cause hypersensitivity reactions (4). although isq values for the prp implants were consistently greater than the control implants at all time points, the values were not statistically significant (p value > 0.05). the results are in agreement with nikolidakis et, al., who investigated the effect of local application of autologous prp on bone healing in combination with titanium implants placed into tibial cortical bone of goats. they applied prp fraction either via gel preparation and subsequent installation in the implant site (like in this study), j bagh college dentistry vol. 27(4), december 2015 the effect of oral and maxillofacial surgery and periodontics 105 or via dipping of the implant in prp liquid before its insertion. the prp gel was obtained by activation of the prp fraction, while prp liquid was used pure without addition of any agent. they failed to show any statistically significant effect of prp-gel on the bone–implant contact percentage. on the other hand, ‘prp liquid’ (without any activation) observed a significant tendency to favor the bone–implant contact (17). these results corroborate with his previous study nikolidakis et, al., in which a similar study design was used but where the implants were placed in trabecular bone (femoral condyle) (16). the results are also in agreement with studies of other researchers. for example garcia et, al., analyzed the influence of prp gel on bone regeneration around dental implants placed in canine mandibles. after 55 days of healing period, no advantageous effect on the bone–implant contact rate was seen (5). also, el-marssafy et, al., who failed to show any statistically significant effect of prp gel to accelerate the rate of osseointegration or decrease the crestal bone resorption through first 3 months period in immediately loaded dental implant placed in posterior maxillary area (19). an explanation for the difference in result between prp liquid and prp gel, prp gel may be squeezed during placement of implant and its solution could be extracted from it and may be displaced apically as a condensed solid fibrin making it without any beneficial effect. the second reason for not having significant difference could be attributed to the activation of prp, zimmermann et, al., found that when thrombin and calcium were added to platelets preparation, the concentration of tgf-β1 decreased by approximately 60% to 65%. this study found that if not activating the platelets, tgf-β1 concentrations did not significantly change over 6 hours (20). according to marx, any harm to platelet membrane during prp extraction will resulting in releasing of growth factors in a non bioactive situation, which would result to adverse clinical outcomes. to guarantee platelets quality, it is essential to consider the velocity force, the time used in centrifugation, type of collection tube, and the anticoagulant among other factors (11). concerning to centrifugation force, the procedure described by mazzucco et, al. was followed in this study and thus the separation spin of 1200 rpm (160 g) for 10 minutes (1600 g.min) followed by a concentration spin of 3200 rpm (1200 g) for 10 min (12000 g.min) with a total of about 13600 g.min (21). this force application about half the value which is allowed by marx and garg in order not to disrupt platelet cell membrane and growth factors loss within supernatant plasma (≤ 30000 g.min) (4). in regard to the type of collection tubes which were used in the second spin were made from glass (red topped 10 ml plain vacuum tube, afco/ jordan). this type of the tube may not agree with trindade-suedam et, al., who suggested for using plastic tube after the second centrifugation especially when the second speed of centrifugation is more than 600 g. he stated “it was easier to release the platelet pellet (precipitated platelet cells) using a plastic tube than a glass tube. this may be attributable to the fact that the glass can damage the platelets causing their aggregation and activation (22). during aspiration of plasma fraction after the first spin in this study, we aspirated the whole plasma fraction and leaving rbcs fraction without aspiration. eby recommended for aspiration a small amount 15% (about 1mm) of the very top of the rbcs in the mixture of plasma fraction aspiration. the resultant prp will become pink to red (23). the top 10% of the rbcs usually holds a large percentage of immature platelets. the younger platelets, which contain more growth factors and they are larger and therefore centrifuge out in the upper layer of the red blood cell fraction (4). araki and his co-worker in 2011 recommended of using edta as anticoagulant in preparation of prp (24). efeoglu et al. also used edta during their experimental study (25). platelet viability can be measured by the pselectin test. p-selectin is a protein found in the membrane of the platelet alpha granules. the test measures the p-selectin both prior to and following activation with adenosine diphosphate (adp). the p-selectin values of freshly prepared prp are about 10% to 20% and increase to 40% to 60% following adp activation. p-selectin values that do not increase with the addition of adp indicate damaged platelets (4). within the limitations of the present study, no appreciable clinical effect was observed to accelerate the rate of osseointegration of sandblasted acid-etched endosseous dental implants when using topical application of autologous platelet-rich plasma gel into the prepared drill holes immediately before implant placement compared with the control group. the beneficial effect of prp is not dependent on platelet concentration only, platelets viability and activities after processing are more important. j bagh college dentistry vol. 27(4), december 2015 the effect of oral and maxillofacial surgery and periodontics 106 references 1. birang r, torabi a, shahabooei m, rismanchian m. effect of plasma-rich in platelet-derived growth factors on peri-implant bone healing: an experimental study in canines. dent res j (isfahan) 2012; 9(1): 93– 9. 2. siadat h, bassir s, alikhasi m, shayesteh y, khojasteh a, monzavi a. effect of static magnetic fields on the osseointegration of immediately placed implants: a randomized controlled clinical trial. implant dent 2012; 21(6): 491-5. 3. kiran n, mukunda k, tilak-raj t. platelet concentrates: a promising innovation in dentistry. j dent sci res 2011, 2(1): 50-61. 4. marx r, garg a. dental and craniofacial application of platelet-rich plasma. china: quintessence; 2005. p. 3-49. 5. garcia r, gabrielli m, hochuli-vieira e, spolidorio l, filho j, neto f. effect of platelet-rich plasma on periimplant bone repair: a histologic study in dogs. j oral implantol 2010; 36(4): 281–90. 6. marx r. platelet-rich plasma (prp): what is prp and what is not prp? implant dent. 2001; 10(4): 225–8. 7. sharathkumar a, shapiro a. platelet function disorders. 2nd ed. indianapolis, u.s.a: world federation of hemophilia (wfh); 2008. p. 1-15. 8. kamath s, blann a, lip g. platelet activation: assessment and quantification. eur heart j 2001; 22(17): 1561–71. 9. brass l. understanding and evaluating platelet function. american society of hematol 2010: 387-96. 10. marx r, carlson e, eichstaedt r, schimmele s, strauss j, georgeff k. platelet-rich plasma: growth factor enhancement for bone grafts. oral surg oral med oral pathol oral radiol endod 1998; 85(6): 63846. 11. marx r. platelet-rich plasma: evidence to support its use. j oral maxillofac surg 2004; 62(4): 489-96. 12. harmon k, hanson r, bowen j, greenberg s, magaziner e, vandenbosch j, harshfield d, shiple b, audley d. guidelines for the use of platelet rich plasma. international cellular medicine society; 2011. 13. weibrich g, hansen t, kleis w, buch r, hitzler w. effect of platelet concentration in platelet-rich plasma on peri-implant bone regeneration. bone 2004; 34(4): 665-71. 14. graziani f, ivanovski s, cei s, ducci f, tonetti m, gabriele m. the invitro effect of different prp concentrations on osteoblasts and fibroblasts. clin oral implants res 2006; 17(2): 212-9. 15. anitua e. enhancement of osseointegration by generating a dynamic implant surface. j oral implantol 2006; 32(2): 72–6. 16. nikolidakis d, dolder j, wolke j, stoelinga p, jansen j. the effect of platelet-rich plasma (prp) on the bone healing around ca-p coated and non-coated oral implants in trabecular bone. tissue engineering 2006; 12(9): 2555–63. 17. nikolidakis d, dolder j, wolke j, jansen j. effect of platelet-rich plasma on the early bone formation around ca-p coated and non-coated oral implants in cortical bone. clin oral impl res 2008; 19(2): 207– 13. 18. anand u, mehta d. evaluation of immediately loaded dental implants bioactivated with platelet-rich plasma placed in the mandibular posterior region: a clinico-radiographic study. indian soc periodontol 2012; 16(1): 89–95. 19. el-marssafy l, abo ul-dahab o, zahran a, shoeib m. evaluation of immediately loaded dental implants placed in healed bony sites with or without addition of autologous platelet-rich plasma. j am sci 2011; 7(3): 633-43. 20. zimmerman r, arnold d, strasser e, ringwald j, schlegel a, wiltfang j, eckstein r. sample preparation technique and white cell content influence the detectable levels of growth factors in platelet concentrates. vox sanguinis 2003; 85(4): 283–9. 21. mazzucco l, balbo v, cattana e, guaschino r, borzini p. not every prp-gel is born equal. evaluation of growth factor availability for tissues through four prp-gel preparations: fibrinet, regenprp-kit, plateltex and one manual procedure. international society of blood transfusion 2009; 97(2): 110-18. 22. trindade-suedam i, leite f, de morais j, leite e, marcantonio e, leite a. avoiding leukocyte contamination and early platelet activation in plateletrich plasma. j oral implantol 2007; 33(6): 334-9. 23. eby b. plateletrich plasma: harvvesting with a single –spin centrifuge. j oral implantol 2002; 28(6): 297301. 24. araki j, jona m, eto h, aoi n, kato h, suga h, doi k, yatomi y, yoshimura k. optimized preparation method of platelet-concentrated plasma and noncoagulating platelet-derived factor concentrates: maximization of platelet concentration and removal of fibrinogen. tissue engineering: part c. 2011; 18(3): 176-85. 25. efeoglu c, akcay yd, erturk s. a modified method for preparing platelet-rich plasma: an experimental study. j oral maxillofac surg 2004; 62(11): 1403-7. j bagh college dentistry vol. 26(1), march 2014 comparison of regional restorative dentistry 1 comparison of regional bond strength among different types of posts luted with different types of cement ahmed a. al-jumaily, b.d.s. (1) haitham j. al-azzawi, b.d.s., m.sc. (2) abstract background: this in vitro study was carried out to investigate the effect of post space regions (coronal, middle and apical), the effect of post types ( manually milled zirconia post, prefabricated fiber post, prefabricated zirconia post) and the type of cement used (gic, self-adhesive resin cement) on the bond strength between the posts and root dentin by using push-out test. material and methods: forty eight mandibular premolars extracted for orthodontic reasons (single rooted) were instrumented with protaper system (hand use) and obturated with gutta percha for protaper using ah26® root canal sealer following the manufacturer instructions. after 24 hours, post space was prepared using zirix and glassix drills no.3 creating 8 mm depth post space. the prepared samples were randomly divided into three main groups (16 samples each) according to the type of post used (group a. manually milled zirconia post, group b. prefabricated fiber post and group c. prefabricated zirconia post) .each group was subdivided into two subgroups (each subgroup contains 8 samples) according to the type of cement used (subgroup a1.manually milled zirconia post cemented with gic, subgroup a2.manually milled zirconia post cemented with speed cem),( subgroup b1.prefabricated fiber post cemented with gic, group b2. prefabricated fiber post cemented with speed cem) and (subgroup c1.prefabricated zirconia post cemented with gic, subgroup c2. prefabricated zirconia post cemented with speed cem), after cementation and incubation for 24hrs, at 37°c and 100% humidity. each root was sectioned horizontally into 3 slices (2 mm in thickness) representing the coronal, middle and apical regions of the post space. push out bond strength test was performed and measured using a universal testing machine (tinius-olsen) at across head speed of 0.5 mm/min. results: the results showed that regarding the root region, the bond strength values increased significantly from apical to coronal region for all types of posts in both tested cements. for the effect of post type, the manually milled zirconia post cemented with the self-cured resin cement (speed cem) showed higher bond strength values. for type of cement, the self-adhesive resin cement (speed cem) showed higher bond strength values. conclusions: the retention of post restoration was affected by root region, type of post and type of cement used. keywords: zirconia post, fiber post, glass ionomer cement, speed cem, root region. (j bagh coll dentistry 2014; 26(1):1-6). introduction endodontically treated teeth with excessive wear result in a lack of coronal tooth structure and frequently need post to retain the coronal restorative portion. although posts are recommended to strengthen the teeth, several investigators have cautioned that posts with inadequate resistance to rotational forces on the posts can weaken the teeth; consequently root fractures constitute the most serious type of failure in post-restored teeth (1). metal posts may negatively affect the esthetic results. besides corrosion reactions can cause metallic taste, oral burning, oral pain, sensitization, and other allergic reactions. a wide range of esthetic posts have become commercially available, such as fiber reinforced composite resin posts (frc) and yttrium stabilized zirconia-based ceramic posts (2). zirconia has been widely promoted by various cad\ cam systems as a superior material for restorations, so there is a possibility to fabricate the (1) m.sc student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad the entire post-and-core complex from presintered, zirconia-reinforced alumina ceramic blanks using copy milling or computer-aided design/manufacturing (cad/cam) techniques (3). water-based cements, such as glass ionomer cement (gics) have been suggested as alternatives for the luting of posts .the visco elastic properties of gics was rendered more favorable to the preservation of bond integrity than the stiffer resin based-cements during the polymerization shrinkage (4). recently developed self-adhesive resin cements do not require pretreatment of the dentin. because these cements do not use an adhesive system, they drastically reduce the number of application steps, shortening clinical treatment time and decreasing technique sensitivity since it minimizes procedural errors throughout the treatment phases (5). bond strength can be determined by several techniques, but the push out bond strength test is believed to provide a better estimation of the actual bonding effectiveness than conventional shear bond strength test, using a push out protocol, failure occurs parallel to the postj bagh college dentistry vol. 26(1), march 2014 comparison of regional restorative dentistry 2 cement-dentin interface, which is similar to clinical condition. although the micro tensile method has been also applied to root dentin, push out tests seem to be more reliable because of the absence of premature failures and variability of data distribution (6). materials and methods sample selection forty eight extracted single rooted teeth (mandibular premolars), was extracted for orthodontic reasons were used in this study. the age, gender, pulpal status and reason for extraction were not considered, and the criteria for teeth selection including the followings: single straight root, no visible root caries, no fractures, cracks or external resorption on examination with x10 magnifying eye lens and light cure device, diagnostic x-ray was taken to confirm the existence of a single straight canal, fully formed apex and no signs of internal resorption, calcification or previous endodontic therapy, patent apical foramen. samples preparation length of the root was determined by a digital vernier and marker. the tooth hold with moist gauze to avoid dehydration and the crown of the tooth was sectioned with a diamond discs mounted on straight hand piece, under water coolant. the length of the root was adjusted to 14 mm from a flat reference point to the root apex. the mold was obtained by using a plastic test tube (2.5ml). the condensation silicon impression material base and catalyst were mixed according to manufacturer’s instructions; the putty was folded and kneaded gently for about 30 sec. until the color was even, without any stripes. the putty material was placed inside the plastic tubes and the coronal end was adjusted with the coronal end of the tube. after that the teeth were placed in the center of the putty material with the aid of dental surveyor to position the long axis of the roots parallel to that of the plastic tubes. endodontic treatment root canal instrumentation was performed using protaper hand files (dentsply switzerland) in crown down technique. irrigation performed using of 2.5% naocl after every change of file size throughout the cleaning and shaping of the root canals, dried with paper points and filled with gutta-percha for protaper f4 (dentsply switzerland)and ah26 root canal sealar (dentsply, germany).the excess gutta-percha at the canal orifice was removed. the access opening were sealed with temporary filling material, and stored at 37ºc, 100% humidity in an incubator for 24h sample grouping the heavy body mounted roots were randomly assigned into three main groups (16 samples each) according to the type of post used (group a. manually milled zirconia post, group b. prefabricated fiber post and group c. prefabricated zirconia post) .each group was subdivided into two subgroups (each subgroup contains 8 samples) according to the type of cement used (subgroup a1. manually milled zirconia post cemented with gic, subgroup a2.manually milled zirconia post cemented with speed cem), (subgroup b1.prefabricated fiber post cemented with gic, subgroup b2.prefabricated fiber post cemented with speed cem) and (subgroup c1.prefabricated zirconia post cemented with gic, subgroup c2.prefabricated zirconia post cemented with speed cem) post space preparation. after 24 hours, the temporary filling was removed, and the gutta percha of the cervical and middle thirds was removed with pesso drills no.1, and the canal walls of each specimen were enlarged with tapered glassix drills for fiber post groups and tapered zirix drills for zirconia and copy milling posts groups under copious water cooling, creating (8mm) deep post space measured from the coronal end of the root, keeping at least 5mm of guttapercha apically. post space preparation was done with a low speed straight hand piece attached to a dental surveyor to obtain vertical preparation with standard diameter and dentinal walls parallel to the long axis of the roots (7). construction of zirconia post and core: to fabricate a zirconia post, a cast metal post must be fabricated firstly by waxing, green wax (yeti, germany) fabricated in the root samples, phosphate bonded investment(yeti dental, germany) was mixed, then the wax patterns were coated with the investment material using the and allowing the investment to set for 1 hour. after that the ring was placed in a cold furnace (combilabor, germany) and the temperature was set for 480 °c soaked for 15 minutes. the temperature was then raised to 650 °c and held for another 15 minutes before raising it to 950 °c and holding for another 15 minutes. the ring was removed from furnace at the time of nickel based alloy melted in centrifugal casting machine. then the cast post was tried to fit by using a disclosing agent, if a pressure spot was detected it was adjusted with carbide bur to obtain a passive fit. then cast metal posts were fixed in the holding plate of copy milling machine for milling. j bagh college dentistry vol. 26(1), march 2014 comparison of regional restorative dentistry 3 after milling, the milled structure is 30% larger than the cast metal post, this enlargement was necessary to compensate for shrinkage that would be occur during sintering process in zirkon zahn furnace at1500c for 8hours post cementation prior to post cementation, the post space was irrigated with 2.25% naocl and then final irrigation was accomplished with (2ml) of distilled water and the post space was dried with paper point size f4. before cementation procedures, prefabricated posts were marked at a distance of (8mm) from the apical end corresponding to the post space preparation. in this way complete seating of the post could be verified (8). the coronal part of the prefabricated post (above the marked area) was attached to the dental surveyor (mandrel clamp was fitted to the upper arm to hold the post to which the prepared specimens was then fitted) .while for the fabricated post, the core was attached to the mandrel clamp of the dental surveyor. monobond-s was applied to the post surface of subgroups a2, b2 and c2 that were cemented with speed cem with a brush. after being allowed for a 60 seconds contact at room temperature, the post surface was dried with air. after that the cement was mixed according to the manufacturer’s instructions. the cement was then applied to the tip of the #40 lentulo spiral and passed down to the post space .that the heavy body mounted plastic tube placed on the base of the dental surveyor and the upper arm holding the post was lowered down until the post was fully seated inside the post space. excess of luting agent was immediately removed with a small brush. a constant load of (2kg) was applied for 60 sec to stabilize the post in position. the specimens were sealed with temporary restoration and stored in distilled water for 24 hrs, at 37°c. preparation of the specimens for push-out test mold construction after the storage period, the roots were removed from the putty material, washed thoroughly and then embedded in clear orthodontic resin. three ml disposable plastic syringes were used as molds into which the freshly prepared acrylic mixture was loaded. before loading the syringes with acrylic, the apical end of the roots were fixed on the face of the plastic piston of the syringes with a resin adhesive so that the roots would be almost centrally located within the acrylic blocks and to ensure that the sectioning would be almost perpendicular to the long axis of the roots .the acrylic was prepared by mixing powder and liquid as recommended by the manufacturer in a porcelain jar. after loading the syringe with the freshly prepared workable acrylic mixture, the piston of the syringe with the root fixed on its apex was pushed into the acrylic mixture with gentle pressure to allow the complete embedding of the root into the acrylic, and to allow the escape of the excess material through the opened syringe tip. the material was allowed to cure under cooled water to compensate for the anticipated rise in the temperature of the samples subsequent to the exothermic curing reaction of the cold cure resin. the acrylic molds were allowed to cure completely for at least 30min as recommended by the manufacturers (9). after complete curing of the acrylic, the plastic syringes were cut off and the mold was obtained. root sectioning the sectioning of the root was made by using diamond disc mounted on straight handpiece and engine with a rotation speed regulator. the hand piece was assembled in a cutting device. the cuts were made under heavy flow of cold water (1925°c) to minimize the smearing .the extruded part of the post that is not luted to the inside of the canal was sectioned to standardize the diameter of the post at the coronal section, as a result, all the remaining sections (within each sample) had a constant diameter at both the coronal and the apical sides from each specimen, 3 post/dentin sections (cervical, middle, and apical) were obtained, each 2 mm in thickness. thus, each study group of 8 roots provided a total of 24 test specimens. the exact length of post segments in each section was measured using a vernier (10).then each slice was marked on its apical side with indelible marker, one spot for the apical segment, two for the middle and three spots for the coronal segment, to make sure that the load will be applied in apico-coronal direction due to the conical shape of posts. push-out bond strength test push-out test was performed by applying a compressive load to the apical aspect of each slice via a cylindrical plunger mounted on tinius-olsen universal testing machine managed by computer software. the test was carried out in the laboratory of the ministry of science and technology of iraq. because of the tapered design of the posts, different sizes of punch pins were used: 1.0 mm diameter for the coronal and middle slices, and 0.6mm for the apical slices .except for manually milled zirconia post which has agreater diameter, so 1.2mm diameter for the coronal and middle slices, and 0.8mm for the apical slices were used. the punch pin was positioned to contact only the post, without stressing the surrounding root canal walls. j bagh college dentistry vol. 26(1), march 2014 comparison of regional restorative dentistry 4 each specimen was placed in a mold with its apical direction upward and the coronal direction downwards because the load should be applied to the apical aspect of the root slice and in an apical– coronal direction, so as to push the post towards the larger part of the root slice, thus avoiding any limitation to the post movement. the mold was fixed to the lower jaw of the universal testing machine so that the specimen post surface was perpendicular to the compressive force applied. the contact between the punch tip and the post section occurred over the most extended area, to avoid notching of the punch tip into the post surface. loading was performed at a crosshead speed of 0.5 mm/ min until the post segment was dislodged from the root slice (11). a maximum failure load value was recorded in newton (n) and converted into mpa, considering the bonding area (mm²) of the post segments by using the formula of a conical frustum. π (r1+r2)√(r1−r2)²+h² where r1 represents the coronal post radius, r2 represents the apical post radius and h is the thickness of the slice results the results of the descriptive statistics which include the minimum, maximum, mean, and standard deviation values of the push-out test for both types of cements in different root regions are shown in (fig .1), (fig .2), (fig .3), (fig .4), (fig. 5) and (fig .6). fig. 1: mean push-out bond strength of manually milled zirconia post cemented with gic. fig. 2: mean push-out bond strength of manually milled zirconia post cemented with speed cem. fig. 3: mean push-out bond strength of prefabricated fiber post cemented with gic. fig.4: mean push-out bond strength of prefabricated fiber post cemented with speed cem. j bagh college dentistry vol. 26(1), march 2014 comparison of regional restorative dentistry 5 fig. 5: mean push-out bond strength of prefabricated zirconia post cemented with gic. fig.6: mean push-out bond strength of prefabricated zirconia post cemented with speed cem. from figures (1), (2), (3), (4), (5) and (6), it is obvious that the mean push-out bond strength (mpbs) of the speed cem was higher than that of gic in all three regions. it’s also clear that the coronal region in both cements had higher mpbs values, followed by middle and apical regions. the highest mpbs was seen at the coronal region of manually milled zirconia post cemented with speed cem, while the lowest value was seen at the apical region of the prefabricated zirconia post cemented with gic. discussion the bond strength of posts in coronal, middle and apical regions this result could be attributed to different factors: concerning self adhesive resin cement the gradual decease in the number of the dentinal tubules from the coronal to the apical part of the root thus the reduced infiltration of the adhesive into the tubules and less formation of the resin tags in the apical parts, and because the adhesion is enhanced by penetration of the resin into the tubules, its values are low at the apical third. this coincides with other findings (12,13) who stated that the difference in the number of tubules may explain why the strongest adhesion occurred in the most coronal sections where there is a greater number of tubules per square mm, but this result conflicts with gaston et al. and foxton et al. (14,15) who stated that the apical bond strength was significantly higher in the apical region because the bond strength is related more to the area of solid dentin than to the tubule density. gaston et al. and foxton et al. (14,15) prepared that post space without previous endodontic treatment; also they didn’t use any irrigation solution. concerning gic cement the residual water present inside the dentinal tubules is not completely eliminated by drying the root canal with paper points. therefore, this residual water within the dentinal tubules could be advantageously employed to achieve hygroscopic expansion of gics and increasing the frictional resistance to post dislodgment, as the number and size of dentinal tubules is higher in the coronal region so that the amount of residual water will be more which is necessary to achieve a sufficient hygroscopic expansion and increasing the bond strength more than in the coronal region than in the apical region. this coincides with onay et al. (16). who reported a significant difference in bond strength among these three root regions, where the difference in number and size of dentinal tubule may have affected the amount of moisture available for the suggested advantage of hygroscopic expansion of the gic cement. comparison of bond strength among prefabricated fiber post, prefabricated zirconia post and manually milled zirconia post. the result of this study revealed that the highest bond strength for the custom made zirconia post (manually milled zirconia post) cemented with resin cement and the lowest bond strength for the prefabricated zirconia post cemented with glass ionomer cement. the smooth surface and loss of fitness for the prefabricated posts reduce their bond strength.this coincides with pahlevan et al. (17) who stated that the fitness is a critical factor in post retention and it should not rely only on the bonding ability of resin cement for post retention. in this study, the prefabricated fiber post showed higher bond strength than the j bagh college dentistry vol. 26(1), march 2014 comparison of regional restorative dentistry 6 prefabricated zirconia post, due to presence of epoxy resin in the chemical structure of fiber post. this will give a capacity for this post to form a chemical bond with the cement. comparison of push out test values between the self -adhesive resin cement and glass ionomer cement this study revealed that the bonding strength values of the self-curing resin cement material is higher than the glass ionomer cement material, this remarkably superior performance of the adhesion in the root canal when using resin cement may be explained by the unique characteristics of this material. the dentin conditioner that is part of the resin cement has the ability to remove the smear layer, etch and demineralized dentin. this allows monomers with small molecular size to penetrate the opened tubules and the space between the collagen fibrils in the demineralized dentin, creating resin tags and hybrid layer. these structures provide an effective micromechanical retention mechanism for this resin-based cement. while gics bonding mechanism relies on the micromechanical retention of the polymer within the dentin substrate conditioned by the polycarboxylic acid, and also on the ionic interaction between the cement and dentin. this coincides with gernhardt et al. (18) who stated that higher bond strength values were obtained from resin cements because of their retentive properties to tooth structures. but the result findings conflict with pereira et al. (19) who stated that glass ionomer cement delivered better bond strength when compared to resin cement, as possible explanation for such out come was based on the fact that glass ionomer cement gets benefit from post maturation hygroscopic expansion due to water storage, leading to an increased frictional strength. references 1. zhi-yue l, yu-xing z. effect of post-core design and ferrule on fracture resistance of endodontically treated maxillary central incisors. j prosthet dent 2003; 89: 368-73. 2. meyenberg kh, luthy h, schaerer p. zirconia posts: a new all-ceramic concept for nonvital abutment teeth. j esthet dent 1995; 7: 73-80. 3. pfeiffer p, nergiz i, schmage p. yield strength of zirconia and glass fibre posts. j oral rehab 2006; 33:70–74 4. dauvillier bs, feilzer a, de gee aj, davidson cl. viscoelastic parameters of dental restorative materials during setting. j dent res 2000; 79(3): 818-23. 5. monticelli f, ferrari m, toledano m. cement system and surface treatment selection for fiber post luting. med oral pathol oral cir bucal 2008; 13: e214–21. 6. 6.goracci c, tavares au, fabianelli a, monticelli f, raffaelli o, cardoso pc, tay f, ferrari m. the adhesion between fiber posts and root canal walls: comparison between microtensile and push-out bond strength measurements. eur j oral sci 2004; 112: 353 -61. 7. edson a, melissa s, emanuel s, silvana p, ricardo s, manuel n. effect of eugenol–based endodontic cement on the adhesion of intraradicular posts. braz dent j 2006; 17(2):130-3. 8. d’arcangelo c, zazzeroni s, d’amario m, vadin m, de angelis f, trubiani o, caputi s. bond strengths of three types of fibre-reinforced post systems in various regions of root canals. j endod 2008b; 41(4): 322-8. 9. gencoglu n, garip y, bas m, samani s. comparison of different gutta-percha root filling techniques: thermafil, quick-fill, system b, and lateral condensation. oral sur oral med oral pathol oral radiol endod 2002; 92(3): 333-6 10. akgungor g, akkayan b. influence of dentin bonding agents and polymerization modes on the bond strength between translucent fiber posts and three dentine regions within a post-space. j prosthet dent 2006; 95(5): 368–78. 11. vano m, cury ah, goracci c chieffi n,gabriele m, tay fr, ferrari m. the effect of immediate versus delayed cementation on the retention of different types of fiber post in canals obturated using a eugenol sealer. j endod 2006b; 32(9): 882–5. 12. perdigão j, gomes g, augusto v. the effect of dowel space on the bond strength of fiber posts. j prosthodont 2007; 16(3):154-64. 13. zobra yo, erdemi a, turkyilma a, and eldeniz au. effects of different curing units and luting agents on push-out bond strength of translucent posts. am associ endod 2010; 36(9):1521-5 14. gaston ba, west la, liewehr fr, fernandes c, pashley dh. evaluation of regional bond strength of resin cement to endodontic surfaces. j endod 2001; 27(5): 321-4. 15. foxton rm, nakajima m, tagami j, miura h. adhesion to root canal dentin using one and two-step adhesives with dual-cure composite core materials. j oral rehabil 2005; 32(2): 97-104. 16. onay eo, korkmaz y, kiremitci a. effect of adhesive system type and root region on the push-out bond strength of glass-fibre posts to radicular dentine. int endod j 2010; 43: 259-268. 17. pahlevan a,mirzaei m,akbarian s: shear bond strength of zirconia post to root dentine with two different cements and comparison with fiber post. jida 2011;23(1):17-23 18. gernhardt cr, bekes k, schaller hg. short-term retentive values of zirconium oxide posts cemented with glass ionomer and resin cement: an in vitro study and a case report. quintessence int 2005; 36: 593-601. 19. pereira jr, valle al, ghizoni js, ramos mb: evaluation of push out bond strength of four luting agents and sem observation of the dentine fiber glass bond interface. int endo j 2013; 18:10111-12089 ameena f.doc j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 69 awareness and knowledge of oral cancer among final year undergraduate dental students in baghdad-iraq ameena r. diajil, b.d.s., m.sc., ph.d. (1) abstract background: the incidence of oral cancers is increasing all over the world. early detection ofthis important public health matter makes them more amenable to treatment and allows the greatest chance of cure.the aim of this study was to investigate the awareness and knowledge on oral cancer among final -year dental students in iraq. materials and methods: questionnaires were delivered to 160 final–year dental students in the college of dentistry in baghdad. the questionnaire focused on the awareness/knowledge of oral cancer, earlyand common clinical signs and symptoms andassociated risk factors. results: it was found that 87% of students were aware of oral cancer. the followings were recognized as signs and symptoms of oral cancer: persistent ulcer and lymphadenopathy (71 %, 70%), followed by presence of white patch (63%). a satisfactory knowledge was observed on; smoking (86%), family history (84%), old age (63%), sun light exposure (59%), smokeless tobacco (57%), alcohol consumption (55%) and immunosuppression (54%).considering dilatory risk-factors, a satisfactory knowledge was identified on hot and spicy food (57%), but not on the other factors. although satisfactory knowledge of dental risk-factors including premalignant disorders (84%) and previous history of oral cancer (70%) was observed, inadequate knowledge about other factors was observed.91% of future dentists indicated that oral cancer can be cured when detected early. conclusion: this study highlighted the need for more education in dental schools to enhance dental professionals’ awareness and knowledge of oral cancer, aiding in early diagnosis and treatment of patients. keywords: oral cancer, undergraduate dental students, awareness, knowledge. (j bagh coll dentistry 2013; 25(3):69-79). introduction oral cancer is a potentially fatal disease that usually presents late and has a poor prognosis. the most common oral cancer is squamous cell carcinoma (oscc) which affects significant numbers of people around the world. oscc represents more than 90% of head and neck cancers (1, 2) with approximately two thirds are diagnosed at advanced stages (2-4). despite advances in the therapeutic management and increased understanding of the molecular basis of the disease, the proportion of oral cancer cases diagnosed at an early and localized stage is still below 50% (5,6) ; and the five-year survival rate has not improved in recent years (7). oscc may be preceded by potentially malignant disorders (pmds), which can be detected morphologically as leukoplakia, erythroplakia or erythroleukoplakia, reflecting the multi-step process of oral cancer development (810). it has been estimated that one-third of oral pmds progress to cancer (11) and most of them are asymptomatic or present with few symptoms and they are regarded as an intermediate stage between normal and malignant tissues (12). thus, it is important to identify patients at risk of developing pmds and to detect these disorders as early as possible. several risk factors have been associated with the aetiology of pmds and osccs, but tobacco smoking and alcohol consumption (13) are the most important. (1) lecturer, department of oral diagnosis, college of dentistry, university of baghdad. they are independently and synergistically associated with high risk in a dose-dependent pattern (14.15). age, sex (16) and environmental carcinogens such as chemicals, radiation and viruses (17) have been considered significant prognostic and important promoting factors in the development of oral cancer. oral cancer is largely preventable (18) with early diagnosis is greatly increase survival rates as the mouth is easily accessible for self or clinical examination. contrary, the late diagnosis of a significant number of osccs is mostly attributable to delays in patients seeking treatment, insufficient patient awareness, asymptomatic clinical states and/or inappropriate investigation (19,20). according to hollows et al. and mcleod et al. (21,22), lack of public knowledge and awareness is the most significant factor in delaying diagnosis and treatment of oral cancer. some oral cancers are asymptomatic (23) or may experience symptoms differently (21) therefore lack of awareness and /or knowledge of early signs and symptoms of oral cancer among general dental practitioners may also contribute to delays in diagnosis and treatment of oral cancer (24,25). epidemiological studies showed that the incidence of oral cancer varies considerably between different parts of the world with the highest levels in the indian subcontinent and the lower ones in western europe and north america (26, 27). in the uk, oral cancer accounting for over 2% of all new cases of cancer in males and responsible for more than 1% of all new cases of cancer in females (27). in high-risk countries such j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 70 as sri lanka, india, pakistan and bangladesh, cancer of the lip and oral cavity is either the most common or second most common cancer in men, accounting for up to 15% of all new cases of cancer in males (27). in iraq, oral cancer account for about 4.5% of all cancer cases according to iraqi cancer registry and it represent about 37% of the head and neck cancer (28). awareness and knowledge of oral cancer among iraqi dental student is not well documented. there is a lack of studies in iraq about oral cancer and pre-cancer knowledge among final year university dental students. thus the aim of the current study was to assess the oral cancer knowledge and awareness of future general dental practitioners by assessing 5th year undergraduate dental students' knowledge of prevention and early detection of oral cancer. materials and methods study design and population this cross sectional study was conducted among 160 dental students in the college of dentistry in baghdad university. they were approached during seminars after permission was obtained from program coordinators and lecturers. instruments and data collection data were collected by using a selfadministered questionnaire which included four sections: section 1 included questions related to participant socio-demographics. these data included questions on age, gender, marital status, monthly household income class, residence and family history of oral cancer (table 1and figure 1). section 2 consisted of 6 closeended questions, which focused onawareness of oral cancer. awareness was assessed by one question ‘did you hear about oral cancer (table 2). section 3 assessed the knowledge of the final year students by questions on the signs and symptoms of oral cancer with the mostly mentioned manifestations of this disease (table 3). section 4 focused on the associated risk factors and one question about the curability of oral cancer (table 4 and figure 4). the questionnaire was distributed in english language and based on previous work by one of the authors (25, 30 and 31). the questions were mainly closed –ended rather than open questions. a description about the purpose and aim of the study along with the study questionnaires explanation was performed for all participants. see appendix a for questioners. statistical analysis data analysis was performed using statistical package of social sciences (spss) software, version 17.0. descriptive statistics were obtained for all variables in the study with means and standard deviations were applied as appropriate. results socio-demographic characteristics of the participants the mean age of respondents was 22.74 years (sd ± 0.87) and age range was 21-25 years with the majority aged 22 years (42%), followed by 23 years (38%), 24 years (14%) and 25 and 21years (3%) equally . most of the students were females (66%) with remaining 34% were males, being in collage for around 5 years. most of the respondents were singles (96%) and residing in urban area (76%). seventy-seven percent had a middle monthly income, 13 % had high class and 10% with low household income. only 9% of the final year students had a family history of oral cancer. table 1 shows the social and demographic features of the participants. awareness and knowledge of oral cancer the majority of the 5th year dental students were aware of oral cancer (87%) and all of them agreed that early detection can improve the treatment. thirty –nine percent of the final year students knew that lifestyle can influence risk of oral cancer; fruit and vegetable intake 66%; good and frequency oral hygiene 81% and regular check-up and dental visits 93% (table 2). as can be shown in table 3, the majority of students recognized the followings as signs and symptoms of oral cancer; persistent ulcer (71%), lymphadenopathy (70%), presence of white patch (63%), colour changes to white and red (54%) and fixation to underlying tissue (51%). whilst half of the students agreed that a lump of leukoplakia is a well-recognized sign of oral cancer, less than half of the dental students considered the followings as signs of oral cancers; erythroplakia mass (45%), erythroleukoplakia growth (43%), red patch (39%), swelling (37%), altered sensation (34%), induration /necrosis (32%) and oral bleeding was the least recognized symptom (28%). the mostly mentioned manifestations of oral cancer were also investigated and showed that ulcer that does not heal was the most common (79%) , followed by persistent white or red patch (78%) and lump or tissue overgrow (59%). less than half of the students identified the followings as mostly identified manifestations of oral cancer; difficulty in swallowing (48%), difficulty in open the mouth (30%), haemorrhage (30%), abscess, boil, or infection (23%) and prosthesis that fails to fit (22%). regarding the knowledge of risk factors, most of the undergraduate students in this study agreed j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 71 that tobacco smoking (86%) was the major risk factor associated with oral cancer, followed by family history of oral cancer (84%), old age (63%), sun light exposure (59%), smokeless tobaccooral tobacco use (57%), alcohol (55%), immunosuppression (54%) and occupation hazard (50%). whilst less than half of the 5th year dental students considered the following factors as risk for oral cancer; viral infection (41%), gender (37%), chronic trauma (33%), chronic infection (30%) and betel quid chewing (30%). taking in consideration the dietary factor, more than half of the participants (57%) agreed that hot and spicy food was a risk factor of oral cancer and less than half of the students regarded the followings as dietary risk factors for oral cancer; diet low in iron (39%), diet low in vitamin a (33%), low intake of fruit and vegetables (31%), diet low in vitamin c (31%) and high fat diet (7%). the majority of students agreed that the presence of precancerous lesions (84%) and previous history of oral cancer (70%) were risk factors for oral cancer. less than half of students considered the followings as dental risk factor for oral cancer; poor oral hygiene (40%), poor dental condition (30%) and poor fitting dentures (27%). the curability of oral cancer has been investigated with 91% of students agreed that oral cancer can be cured if detected early; table 3. discussion there is a paucity of information regarding undergraduate dental student oral cancer awareness in iraq. in this study, we conducted a questionnaire survey among 160 final -year undergraduate dental students in collage of dentistry -university of baghdad to investigate oral cancer awareness and knowledge of the future dental practitioners in iraq, regarding early detection, clinical presentation, associated risk factors and curability of oral cancer. in iraq, according to iraqi cancer registry oral cancer account for about 4.5% of all cancer cases and it represent about 91.5% of all oral cancer and 37% of the head and neck cancer (28). researchers in the field of oral oncology believe that early detection and diagnosis of oral cancer greatly increases the chance of cure and survival rates in addition to minimizing impairment and deformity (32, 33). lack of public awareness has been reported to be the most significant factor in delaying referral and treatment of oral cancer (21,22). delay in presentation and patient referral has a significant impact on the associated morbidity and mortality. the rate of awareness among dental student in this study (87%) was in line with a study conducted by al dubai among university students in malaysia (29), which found that the majority of respondents were aware of oral cancer (92 %). this finding was higher than that among uk medical students (24) and also higher than that found among general population from uk (56 %) (33) and iran (10.6 %) (6). authors concluded that there is a need to introduce various educational programs to increase awareness of oral cancer. in this study, persistent ulcer, lymphadenopathy and presence of white patch were the most commonly identified signs and symptoms, were recognized by more than 60% of the final year students. however erythroplakia mass, erythroleukoplakia growth, red patch, swelling, altered sensation, induration and oral bleeding were only known by less than half of the dental students. the current study showed that almost half of the undergraduatestudents agreed that the presence of red or white plaques was not associated with oral cancer, is in accordance with other studies (6,31).this finding may be problematic because in addition of being an early signs of oral cancer,red/white lesions can correspond to oral potentially malignant disorders which should be early detected and treated to reduce the risk of malignant transformation and to have a good prognosis. the results of the present study have confirmed that there was an overall deficiency in oral cancer awareness and knowledge amongst undergraduate dental students regarding early signs and symptoms with clinical presentation. this finding was similar to that of previous studies conducted in nigeria (34), united kingdom (24) and amongst undergraduate dental students of lahore – pakistan (35). thus, there is a vital need for increase awareness and knowledge about oral cancer for an early detection with subsequent effective management and eventually improvement in quality of life for patient. regarding oral cancer risk factors, our study showed that 95 % of respondents identified smoking as the most common risk factor for oral cancer which is consistent with other studies from different countries (24,33,35), followed by family history of oral cancer. in this study, other risk factors such as old age (63%), sun light exposure (59%), smokeless tobacco, alcohol drinking, immunosuppression and occupation hazard were commonly recognized by more than half of the students, whilst viral infection, gender, chronic trauma/infection and betel quid chewing were j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 72 recognized by less than half of the students. these risk factors were also reported among medical and dental students in various studies as well as in general population (24, 35-37). tobacco smoking as a risk factor for oral cancer was realized by the majority of the final year students. however, alcohol was identified to a lesser degree as a risk factor. knowledge on the increased cancer risks by alcohol use should be included in future health promotion strategies, such as lectures and seminars. this study found that more than 50% of the final year students agreed that hot and spicy food was a risk factor of oral cancer, less than one-third of students were able to recognize diet low in iron, vitamin a, c, low intake of fruit and vegetables and high fat diet as dilatory risk factors of oral cancer. in addition, the majority of the 5th year students agreed that the presence of premalignant disorders and previous history of oral cancer were well-recognized dental risk factors of oral cancer. however, poor oral hygiene, poor dental condition and poor fitting dentures as oral cancer risk factors were only known by less than half of students in this study. the unsatisfactory knowledge of some oral cancer risk factors found in this study, is in agreement with previous studies (24, 33). therefore, there is a vital need to introduce and focus on these factors in the final year dental students’ educational programme and events. the majority of the respondents in this study were aware about oral cancer with 91% of them agreed that this type of cancer could be cured if detected early. in conclusion, awareness and knowledge about key signs and symptoms among final-year iraqi dental students and its major risk factor were found satisfactory. however, there was inadequate knowledge observed regardingother associated risk factors. therefore, it is suggested that efforts should be made to introduce oral cancer education for future general dental practitioners on clinical presentation, early manifestation, early referral and possible associated risk factors to cultivate positive attitude towards prevention of oral cancer. since this study is limited by its small sample size, studies with larger samples are recommended to confirm the findings which may help to expand the knowledge base for future dentists in iraq to help in early detection and diagnosis of oral cancer. acknowledgments the author wish to acknowledge the help of colleagues in the oral diagnosis department at the college of dentistry university of baghdad. references 1. arduino pg, carrozzo m, chiecchio a, broccoletti r, tirone f, borra e, bertolusso g, gandolfo s. clinical and histopathologic independent prognostic factors in oral squamous cell carcinoma: a retrospective study of 334 cases. j oral maxillofac surg 2008; 66(8): 1570-9. 2. warnakulasuriya s. global epidemiology of oral and 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2001; 37(3): 205-10. http://www.cancerresearchuk.org/cancer j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 74 table 1. socio-demographic characteristics of the respondents (n=160). socio-demographic characteristics of the respondents characteristics number % age (21-25) years gender male 48 30% female 112 70% marital status single 156 96% married 5 3% divorced 1 1% year of study 5th household income class low 16 10% middle 123 77% high 21 13% residence urban 122 76% rural 38 24% family history of oral cancer yes 15 9% no 145 91% figure 1. socio-demographic characteristics of the respondents (n=160). j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 75 table 2. awareness of oral cancer amongrespondents (160). awareness of oral cancer number % have you heard about mouth cancer? yes 139 87% no 7 4% no idea / i don’t know 14 12% early detection can improve treatment yes 160 100% no 0 0% lifestyle influence risk of oral cancer yes 148 93% no 12 8% fruit and vegetables yes 105 66% no 55 34% good and frequency oral hygiene yes 130 81% no 30 19% regular dentist visits and check up yes 148 93% no 12 7% table 3. knowledge of oral cancer among respondents (n=160). knowledge of oral cancer among respondents (n=160) clinical signs of oral cancer number % swelling 42 37% white patch 37 63% red patch 45 39% persistent ulcer 82 71% oral bleeding 32 28% colour changes to white and red 62 54% erythroplakia mass (red lesion) 52 45% leukoplakia lump (white lesion) 58 50% erythroleukoplakia growth (white and red lesion) 49 43% induration /necrosis 37 32% fixation to underlying tissue 59 51% lymphadenopathy 80 70% altered sensation 39 34% mostly mentioned manifestations of oral cancer sore (ulcer) that does not heal 91 79% lump or tissue overgrow 68 59% difficulty in swallowing 55 48% difficulty in opening the mouth 34 30% prosthesis that fails to fit 25 22% persistent white or red patch 91 78% j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 76 table 4. recognised risk factors of oral cancer. recognised risk factors of oral cancer number % sex 43 37% old age 73 63% tobacco smoking 99 86% oral tobacco use/ smokeless tobacco use 65 57% betel quid chewing 35 30% drinking alcohol 63 55% family history of oral cancer 97 84% obesity 5 4% chronic trauma 38 33% sun (uv light) exposure 68 59% viral infection 47 41% immunosuppression 62 54% chronic infection 35 30% occupation 57 50% car smoke 29 25% don’t know 0 0% dietary factors reduced intake of fruit and vegetables 36 31% diet low in iron 45 39% diet low in vitamin a 38 33% diet low in vitamin c 36 31% high fat diet 8 7% hot & spicy flood 66 57% dental factors chronic irritation from jagged (sharp) teeth 46 40% infections in the teeth 15 13% poor dental condition 35 30% high number of missing teeth 8 7% poor oral hygiene 53 40% poor fitting dentures 31 27% pre-cancerous conditions/lesions 97 84% previous history of oral cancer 80 70% no idea 1 1% i don’t know 2 2% curability oral cancer can be cured if detected early yes 146 91% no 14 9% j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 77 figure 4. recognised risk factors of oral cancer. j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 78 appendix (a) oral cancer knowledge and awareness amongst undergraduate dental students in baghdad university-college of dentistry please circle as appropriate socio-demographic characteristics year of study gender male female age marital status single married divorced household income class low middle high residency rural urban family history of oral cancer yes no knowledge of oral cancer clinical signs/ oral changes associated with oral cancer /recognised early signs of mouth cancer swelling white patch red patch persistent ulcer oral bleeding colour changes to white and red ulceration exophytosis erythroplakia mass (red lesion) leukoplakia lump (white lesion) erythroleukoplakia growth (white and red lesion) induration /necrosis fixation to underlying tissue lymphadenopathy altered sensation recognised risk factors of oral cancer sex old age tobacco smoking oral tobacco use/ smokeless tobacco use betel quid chewing drinking alcohol family history of oral cancer obesity chronic trauma sun (uv light) exposure viral factors immunosuppression chronic infection occupation car smoke close contact with another cancer patient don’t know dietary factors reduced intake of fruit and vegetables diet low in iron diet low in vitamin a diet low in vitamin c high fat diet hot & spicy flood dental factors: chronic irritation from jagged (sharp) teeth infections in the teeth j bagh college dentistry vol. 25(3), september 2013 awareness and knowledge oral diagnosis 79 poor dental condition high number of missing teeth poor oral hygiene poor fitting dentures pre-cancerous conditions/lesions previous history of oral cancer no idea/ i don’t know mostly mentioned manifestations of oral cancersigns and symptoms sore (ulcer) that does not heal lump or tissue overgrow difficulty in swallowing haemorrhage abscess, boil, or infection difficulty in open the mouth persistent white or red patch prosthesis that fails to fit curability oral cancer can be cured if detected early yes no awareness of oral cancer have you heard about mouth cancer? yes no no idea / i don’t know early detection can improve treatment yes no lifestyle influence risk of oral cancer yes no fruit and vegetables yes no good and frequency oral hygiene yes no regular dentist visits and check-up yes no thanks very much for your participation noor final.doc j bagh college dentistry vol. 26(2), june 2014 selected salivary orthodontics, pedodontics and preventive dentistry 150 selected salivary constituents, physical properties and nutritional status in relation to dental caries among 4-5 year’s old children (comparative study) noor a. kadoum, b.d.s. (1) ban a. salih, b.d.s., m.sc. (2) abstract background: tooth decay is still one of most common diseases of childhood, child’s primary teeth are important even though they aretemporary. this study was conducted to assess the physiochemical characteristic of saliva among caries experience preschool children and compared them with caries free matching in age and gender. then an evaluation was done about these salivary characteristics to dental caries and evaluated the relation of body mass index to dental caries and to salivary variables. materials and method: after examination 360 children aged 4-5 years of both gender. caries-experiences was recorded according to dmfs index by (world health organization criteria 1987) during pilot study children with caries experience was divided in to three groups according to decay fraction of decay missing filled surfaces index .mild with decay surfaces<6, moderate with 6≤decay surfaces≤13 and severe with decay surfaces>13 and select thirty children with moderate caries experience and compared with thirty caries free children decay missing filled surfaces=0 match in age and gender. nutritional status of each child was assessed by measuring weight and height to calculate body mass index. unstimulated saliva collected from sixty child under standardized condition and potential hydrogen and flow rate were measured. total antioxidant concentration, total protein, calcium, inorganic phosphorus, zinc and copper were measured. results: statistically highly significant differences were found in concentration of salivary calcium and inorganic phosphorus between caries-experience and caries free children with higher mean value among caries free group. statistically significant differences were found in concentration of salivary zinc between groups. statistically nonsignificant differences were found in concentration of salivary total antioxidant, total protein, copper and body mass index between caries experience and caries free groups.salivary flow rate and ph showed statistical non-significant differences between groups. positive non-significant correlation was found between dmfs index, (ds) fraction of dmfs index and salivary flow rate, total antioxidant and negative correlation with salivary ph, total protein, calcium, phosphorus, zinc and copper. positive a non-significant correlation was found between bmi, salivary flow rate, ph, total antioxidant, zinc and copper while a negative weak correlation found with dmfs, ds fraction of index and salivary total protein, calcium and inorganic phosphorus in caries experience group. furthermore a non-significant positive correlation was found between bmi, salivary flow rate, ph, total antioxidant inaddition to that negative weak correlation was found with salivary total protein, calcium inorganic phosphorus, zinc and copper among caries free group. conclusion: the findings of the present study showed that inorganic components of saliva play an important role in reminerlization of incipient caries and there is an inverse association between body mass index and dental caries. keywords: dental caries, bmi, saliva, inorganic components. (j bagh coll dentistry 2014; 26(2): 150-156). introduction dental caries is one of the most common, communicable and intractable infectious disease in human. it remains the persistent important oral health problem internationally and particularly among developing countries (1-4). early childhood caries is most common chronic illness among children and adolescent, caries progression can lead to pain and reduced ability to chew and eat which may also lead to iron deficiency due to malnutrion. reduction of quality of life for children with early childhood caries resulting from disturbed sleeping and concentration problems (5). saliva is biological fluid in oral cavity composed of mixture of secretary product from major and minor salivary gland. the fact that teeth are in co (1)m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2)professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad nstant contact with and bathed by saliva suggests this environmental agent would profoundly influence the dental caries process (6,7). a protective potential role of saliva in pathogenesis of caries process has been implicated in various studies, but possible role of endogenous host-associated attributes of saliva in disease process has so far received little attention (8).among which one of most important function of saliva is defense function to the specific and nonspecific antibacterial factor included in it as well as to antioxidant defense system, antioxidants have many health benefits that made their evaluation in disease process very popular (912). relative protections against dental cavities, flow rate, buffering capacity, calcium, phosphate, and fluoride concentration are essential (13). presences of various types of trace elements in saliva, certain investigators have reported that trace elements to be cariogenic and others as j bagh college dentistry vol. 26(2), june 2014 selected salivary orthodontics, pedodontics and preventive dentistry 151 cariostatic (14). saliva contain a large number of proteins that participate in protection of oral tissue in addition several peptides with bacterial killing activity have been identified for instance lysozyme, lactoferrin, immunoglobulin, mucin and histatin (15). the calcium and phosphate ions in saliva will help to prevent dissolution of dental enamel and help reminerlization phase, the calcium is most efficient ph buffer for regulating body fluid while phosphates have additional advantage of being resistant to depression of plaque ph towards the critical ph (16). nutrition is an integral component of oral health, there is continuous synergy between nutrition and integrity of oral cavity in health and disease. malnutrition may affect the development of oral cavity and progression of oral disease through altered tissue hemostasis, reduced resistance to microbial biofilm and reduced tissue repair capacity (17,18). national study from sweden conducted by alm et al (19) suggests positive correlation between dental caries and body mass index (bmi). other shows an inverse relationship (20). as for literature available very little has been discussed about dental caries and salivary total antioxidants while no previous iraqi study has been conducted to investigate relation of total antioxidant and inorganic composition of saliva in relation to moderate caries experience among kindergarten children. for these reasons this study was conducted. materials and methods sample this study include preschool age children of both gender collected from private and governmental kindergarten schools from different region in baghdad city, the work in this study extend in period from 12 of december 2012 till the end of april 2013. after examination include 360 child age (4-5) years of both gender, selected sixty children and divided in to two groups caries experience group (study group) thirty child, caries experience measured according to dmfs index (ds) fractions and classify children with different caries experience in to three groups during pilot study mild with ds<6, moderate with 6≤ds≤13 and severe with ds>13(21), and select moderate caries experience group and thirty child caries free (control group) with dmfs zero caries status recorded using (22). both groups match in age and gender. any child had erupted lower permanent molar and or incisor was excluded, child on medication, child with systemic or local disease which affect salivary secretion. assessment of nutritional status: measurement of weight children were weighed by bathroom scale, children reading was recording to the nearest of 0.1kg as possible. the instrument used was checked and standardized against a known weight of 5kg and adjusted in the morning before measurements were started and after weighing every 20 children (23). children were weighed with minimum clothes without shoes and head covering and without touching anything, then 500 gram were subtracted from the total weight to compensate of the light underneath cloths (24). measurement of height the height of the child was measured by using ordinary measuring tape fixed at the wall, the child was standing up after removing his/her shoes with feet parallel to each other and pointed forward and the back of the child is straight in upright position. the knee was straight and the child's head was in position that the line between the lower boarder of the orbit and the upper margin of the external auditory meatus (frankfort plane) is horizontal. the sliding head piece is lowered to rest on the head; the measurement should be recorded to the nearest 0.1cm (23).body mass index (bmi): this index is a number calculated from child's weight and height, according to this formula: bmi = (25) because of unavailability of iraqi standard for comparison, the value of nutritional indicators were compared with the international reference values, for this purpose it was recommended to use the reference population that defined by national center for health statistics in collaboration with the national center for chronic disease prevention and health promotion and using cdc growth charts. collection of salivary samples collection of saliva is done at morning 9-11 am in the second appointment to reduce the anxiety and fear that might occur after clinical examination unstimulated saliva collected in a sterile graduated test tube. resting saliva collected for 10 minute by spitting method(26). ph of resting saliva was measure using digital ph meter, the flow rate of saliva was expressed as millilitre per minute (ml / min) after the foam is all disappeared (27).the samples were centrifuged at 1500rpm for 5minute the clear supernatant was separated by micropipette and was stored in a deep freeze for the subsequent analysis which was carried (28). j bagh college dentistry vol. 26(2), june 2014 selected salivary orthodontics, pedodontics and preventive dentistry 152 biochemical analysis of saliva essential elements of saliva (calcium, zinc and copper) were analysed by using flame atomic absorption spectrophotometer following standardized procedure. while total antioxidant concentration (tac) was measured by usinga ready-madekit (cayman chemical company) and analysed by enzyme linked –immunosorbent assay (elisa) machine. total protein, inorganic phosphorus measured by using a ready-made kits of (syrbio, biomagrhreb, tunisia respectively) and analyzed by uv visible recording spectrophotometry (cecil ce 7200 uk) machine. results the results showed that the test distribution is normal for all readings of the studied parameters in the caries free and caries experience groups by using one-sample kolmogorov-smirnov test procedure and that indicating the successfulness of applying the conventional methods either of descriptive or inferential tools of the statistical parametric hypotheses. sixty children included in this study. thirty of them were caries experience with (ds) fraction ranging from 6-13as study group,and other thirty were caries free with dmfs=0 as control group matching in age and gender. age range of children was 4-5 years , 53.6% boys of both group at age 4years, 46.4%girls of both groups at age 4 years, 50% boys of both groups at age 5 year, 50%girls of both groups at age 5years. table (1) demonstrates comparison between the caries experience and caries free group regarding salivary flow rate measured in (ml/min) and ph. theresultsshowed statistically nonsignificant differences at p>0.05. table (2) demonstrate comparison of salivary total antioxidant concentration measured in (mm)and total protein measured in mg/dl the results showed statistically non-significant differences at p>0.05.statistically highly significant differences at p<0.01between caries experience and caries free regarding salivary calcium and inorganic phosphorus with higher value among caries free group.the results showed that the caries free group had higher mean value than the caries experience group (5.86± 1.77, 4.90±1.22 respectively) with statistical significant differences at p<0.05 in concentration of salivary zinc table (4).statistically nonsignificant differences at p>0.05in concentration of salivary copper and bmi between caries experience and caries free group table (5). a non-significant positive weak correlation found between dental caries and salivary flow rate and tac while a non-significant negative weak correlation found between dental caries and salivary ph, total protein, phosphorus, zinc, copper and calcium. a non-significant positive weak correlation found between bmi, salivary flow rate, ph, total antioxidant, zinc and copper. a non-significant negative weak correlation found with dental caries and salivary total protein, calcium and phosphorus among caries experience group. a non-significant positive weak correlation found between body mass index and salivary ph, flow rate, total antioxidant. a non-significant negative weak correlation found with salivary total protein, calcium, phosphorus, zinc and copper among caries free group. table 1: comparison of salivary flow rate ml/min ph between caries experience and caries free groups p-value t-test d.f. caries free caries experience no. variables sd mean sd mean 0.44 -0.77 58 0.23 0.38 0.24 0.42 30 flow rate 0.72 -0.35 58 0.37 6.98 0.33 6.94 30 ph table 2: comparison of salivary tac (mm) and total protein mg/dl between caries experience and caries free groups p-value t-test d.f. caries free caries experience no. variables sd mean sd mean 0.63 -0.48 58 0.15 0.20 0.18 0.22 30 tac 0.33 0.98 58 75.68 438.30 51.17 422.00 30 total protein table 3: comparison of salivary calcium and phosphorus mg/dl between caries experience and caries free groups p-value t-test d.f. caries free caries experience no. variables sd mean sd mean 0.000 7.95 58 0.72 4.52 0.67 3.09 30 calcium 0.000 4.70 58 2.85 6.97 2.30 3.83 30 phosphorus j bagh college dentistry vol. 26(2), june 2014 selected salivary orthodontics, pedodontics and preventive dentistry 153 table 4: comparison of salivary zinc µg/dl and between caries experience and caries free groups p-value t-test d.f. caries free caries experience no. variables sd mean sd mean 0.017 2.45 58 1.22 5.86 1.77 4.90 30 zinc table 5: comparison of salivary copper µg/dl and bmi between caries experience and caries free groups p-value t-test d.f. caries free caries experience no. variables sd mean sd mean 0.28 -1.08 58 1.52 3.35 1.20 3.73 30 copper 0.96 0.05 58 2.12 16.40 2.01 16.38 30 bmi discussion dental caries a common disease in children, if untreated can affect body weight, growth and quality of life in preschool children (29). in young children as in adult caries can begin as soon as the teeth erupt and can rapidly progress to extensive decay of all primary teeth (30).decision was made to collect unstimulated whole saliva because this type of saliva predominates during most part of the day and is important for maintenance of oral health, reflecting the physiological status of the oral cavity and the entire body (31). under resting conditions without the exogenous stimulation that is linked with feeding there is a slow flow of saliva which keeps the mouth moist and lubricates the mucous membrane. this unstimulated flow which is secreted by the salivary glands majority of the time. unstimulated saliva is essential for the health and well-being of the oral cavity and also provides a strong protective effect to the oral cavity, against dental caries (32, 33). the results of the present research found non-significant differences attributed to salivary flow rate located within normal range .unstimulated flow rates of less than 0.1 ml/minute are considered evidence of hyposalivation ,the unstimulated flow rate averages 0.3 to 0.4 milliliter per minute, but the range is wide (34).and higher mean value with study group and positive correlation with dental caries could be attributing to moderate caries experience, dmfs index is a life –time cumulative index of dental disease and treatment and may have little bearing on caries activity at a specific point in time and one –time determination of salivary flow rate may not be a comprehensive evaluation of salivary function (35).finding of the present study can be explained by that salivary ph in subject with low or no caries activity had resting salivary ph of around 7.0 and those with extreme caries activity had resting ph below critical ph (5.5) and also could attributed to the level of ph in the enamel dissolution in caries process which needs to fall below the critical ph (36,37). the data of the present study illustrated a non-significant positive weak correlation between tac and dental caries. such positive correlation although not reach to significance value may demonstrate to that the levels of antioxidants could be altered in response to an infection or disease. the absence of an infectious challenge in the form of caries or poor oral hygiene in the present study among caries free could be one of the factors for the comparatively decreased levels of tac of saliva (38). total protein in the present study showed a higher mean level with caries free group than caries experience (422.0±51.17, 438.3±75.68 respectively) with nonsignificant differences and non-significant weak invers correlation of total protein with dental caries. result of the present although not reach to statistical significancecould related to action of salivary protein such as action of some protein as antimicrobial and ph modulating (39) also attributed to function of certain protein like early pellicle protein, proline-rich protein and statherin which promote reminerlization of enamel by attracting calcium ion and demineralization process is retarded by pellicle protein in concert with calcium and phosphate ions in saliva and in plaque fluid and several salivary (glycol)protein prevent adherence of oral microorganism to enamel pellicle and inhibit their growth (33). the finding of the present research interpreted as the saliva which is supersaturated with calcium and phosphate acts as a reservoir for these essential ions. in such a conducive environment the process of remineralization overrides demineralization (40).calcium in saliva acts as chief mineral to prevent dissolution of teeth via its solubility constant and continuous supply to affected areas of teeth, optimum concentration of calcium in saliva prevents dental caries and promotes remineralization, by giving strength and perfectness to the structure of teeth (41,42).the increase level of phosphorus among caries free give idea about potential effect of inorganic phosphate in remineralization of incipient caries lesion. inverse relation with ds fraction and dmfs related to its action in buffer and reminerlization(43) and phosphate can probably j bagh college dentistry vol. 26(2), june 2014 selected salivary orthodontics, pedodontics and preventive dentistry 154 interfere with adherence of pellicle and bacterial plaque to enamel surfaces (44). high level of zinc leads to greater mineralization and accumulation of zinc quantities on surface enamel that becomes more caries resistance (45). deficiency of micronutrient like zinc can influence amount and composition of saliva and reduce protective effect of saliva (46). increased susceptibility to dental caries in zinc-deficient animals might be mediated by alterations in salivary proteins that are associated with the maintenance of tooth structure (47).the inverse relation of copper with dmfs index and ds could be related to the divalent metal ions properly inhibit glycolysis in dental biofilm and anti-biofilm effect related to antimicrobial activity and displacement of ca++ ions from pellicle and microbial surface and change of microorganism adherence (43).these inverse relation of current study between bmi and dental caries although not reach to statistical differences could be explained by under nutrient and deficiencies of specific nutrient do influence the development of teeth and formation and function and secretion of saliva which in turn influence susceptibility to dental caries (48) also malnutrition can indirectly increase susceptibility to dental caries by affecting structure of tooth maturation and provide more cariogenic environmental niche and less protective enamel that include hypomineralization (49,50).furthermore non-significant positive weak correlation obtained between bmi and both salivary flow rate and ph such correlation may be related to the fact that nutritional deficiencies have been found to affect both salivary gland formation and function as well as composition in which moderate to severe protein malnutrition revealed decrease in stimulated secretion rate, lower content of calcium and chloride ions and total protein secretion and impaired immunological and agglutination defense factors of unstimmulated saliva (51). there was no previous study concerning correlation of salivary constituents to bmi so the finding could attribute in comparison to serum constituent and discuss correlation systemically, as saliva consider a mirror of serum (52). the finding in present study related to tac showed non-significant positive weak correlation with bmi in both caries experience and caries free group. such positive correlation although not reach to statistical significant point could be attributed to increase bmi, associated with oxidant stress increase. possible mechanism contributing to the obesity–associated oxidant stress include increase oxygen consumption and subsequent radical production via mitochondrial respiration, increased fat deposition and cell injury causing increased rate of radical formation (53) these finding in agreement with sfar et al (54) who found activity of super oxide dismutase increase in association with increase bmi and consider obesity independent risk factor of free radical production result in an increased antioxidant response. these findings of current study also agree with keaney et al (55) who found strong association between bmi and markers of oxidant stress related to adiposity as main factor for increase oxidant stress. the possible causes for inverse relation of calcium and bmi could be high calcium intake depresses 1,25 dihydroxy vitamin d leading to decrease in intercellular calcium, thereby inhibit lipogensis and stimulate lipolysis so higher fat oxidation gain by creating a balance of lipolysis over lipogensis in adipocyte (56). however negative correlation of phosphorus may be related to the role of phosphorus in degradation of fat as fat transport to their many destinations in body through phosphorylation (57). the findings of the current study attributed systemically as there was no previous study concerning relation of salivary zinc with body mass index and such positive correlation found between salivary zinc and 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(ed). comprehensive preventive dentistry. john wiley & sons; 2012. p. 99-115. 47. johnson da, alvares o. zinc deficiency-induced changes in rat parotid salivary proteins. j nutr 2013; 114: 1955-64. 48. moynihan p. diet and dental caries.in: murry jj, nunn jh, steele jg (eds). the prevention of oral disease.4th ed. oxford: 2003. p. 9-34. 49. suckling g, elliott dc, thurley dc .the production of developmental defects of enamel in the incisor teeth of penned sheep resulting from induced parasitism arch oral biol 1983; 28: 393-9. 50. who. nutritional research, background document technical discussions. geneva, 1990. 51. decker t r, sirois d, mobley cc. nutrition and oral medicine. 1st ed.springer; 2007 52. kaufman e, lamster ib .the diagnostic application of saliva. int and am assoc for dent res 2002; 13(2):197-212. 53. vincent h, power s, dirks a, scarpac p. mechanism for obesity–induced increase in myocardial lipid peroxidation. int j obes 2001; 25: 378-88. 54. sfar s, boussoffara r, sfar mt, kerkeni a. antioxidant enzyme activities in obese tunisian children. nutr j 2013; 12:18-25. 55. keaney j, larson m, vasan r,et al. obesity and systemic oxidative stress clinical correlates of oxidative stress in the framingham study, arterioscler thrombvasc biol 2003; 23: 434-9. 56. kruger hs. relationship between calcium intake and anthropometric indices. in: victor r p, hand book of anthropometry, springer, 2012; 2875-2893. 57. costa d, motta s. minerals in: albanese a eds. newer methods of nutritional biochemistry v1: with applications and interpretations, elsevier; 2012. p.429483. 58. thorpe ste. the pearson general studies manual. 1st ed. pearson education india; 2009. 59. comeaux t. the definitive guide to natural pregnancy healthwhy your prenatal vitamin may not be enough. dog ear publishing; 2007. j bagh college dentistry vol. 32(2), june 2020 effect of plasma 22 effect of plasma treatment on some surface properties of acrylic resin polymer shaymaa h. masood (1), salah a. mahamed (2) article doi: https://doi.org/10.26477/jbcd.v32i2.2890 abstract background: polymer surfaces usually present problems in bonding and finishing due to their low hydrophilicity. the aim of this study is to investigate the effect of plasma treatment with the use of two types of gases (oxygen and argon) on surface roughness, and chemical surface properties of acrylic resin denture base polymer material. materials and methods: three heat cured acrylic resin specimens of (2*8*30 mm) dimensions were prepared for each test carried out in this study. two tests were conducted, surface roughness test and chemical surface analysis test. results: application of plasma treatment increased surface roughness for both oxygen and argon plasma treated acrylic resin specimen groups compared with control untreated group, with a highly significant difference (p <0.01) among groups. ftir chemical analysis for oxygen plasma treated acrylic resin specimen group showed a spectrum with a broad peak, which represents the hydroxyl group (-oh). this was an important chemical change that increased the hydrophilicity as compared with ftir spectrums of control and argon plasma treated acrylic resin groups which exhibited relatively the same peaks with mild chemical changes. conclusion: application of oxygen and argon plasma treatment represents an effective surface treatment method for increasing the surface roughness of acrylic resin denture base polymer material. oxygen plasma treatment can activate the treated surface towards further chemical reactions, and increase the hydrophilicity of the acrylic resin denture base polymer material. key words: acrylic resin polymer, plasma treatment, surface roughness, ftir analysis. (received:18/12/2019; accepted:20/1/2020) introduction since the 1940s, acrylic resins are the most polymer materials that are used to fabricate denture base in dentistry. poly (methyl methacrylate) resin is the most common resin that is used in dentistry.(1) polymer surfaces usually present problems in bonding and finishing due to their low hydrophilicity.(2) schemes to modify pmma surfaces fall in two basic categories: photophysical and photochemical methods, such as laser alteration or uv irradiation in air, and “wet” chemical modifications. other chemical modification schemes involve plasma treatment of pmma to activate the surface toward further reactions.(3-5) many different types of gas-plasmas have been cited in the literature including air, oxygen, uv-ozone, h2o, ammonia, and argon for modification of polymer surfaces. (6-10) several studies were conducted regarding the use of plasma treatment for acrylic denture base materials.(11-13) the present study aims to investigate the effect of plasma treatment on some surface characteristics of acrylic resin polymer material. materials and methods (1) m.sc., ministry of health and environment. (2) professor, department of prosthodontics dentistry, college of dentistry, university of baghdad. corresponding author, shaimahasan76@gmail.com three heat cured acrylic resin (pmma) specimens were prepared for each test done in this study. the specimen dimensions were 2×8×30 mm. these specimens were prepared from sr triplex hot, heat cured acrylic denture base material (ivoclar vivadent, germany). for each test done in this study, the specimens were grouped as control/plasma untreated, oxygen plasma treated and argon plasma treated acrylic resin specimens groups. in this study the application of the two types of gases (oxygen and argon gases) were done with the use of the plasma apparatus with parameters: 800 v, 75 ma, power 60 w, with 2 minutes exposure time. surface roughness test three specimens of heat-cured acrylic resin denture base material (ivoclar vivadent) were prepared according to the manufacturer’s instructions. immediately after preparation, the surface roughness for the control specimen group was measured. the other two specimens were measured after oxygen and argon plasma treatment. the surface roughness for each specimen was measured in 5 areas by the use of the surface roughness tester. chemical surface analysis (ftir analysis) with a view to understanding the surface-chemical changes of acrylic denture base material (pmma) after the application of oxygen and argon plasma treatment, the chemical changes which appeared on the surface of the untreated and plasma treated acrylic (pmma) specimens were investigated using ftir analyzer (fourier transform infrared spectrophotometer, shimadzu, ftir-8400s). https://doi.org/10.26477/jbcd.v32i2.2890 j bagh college dentistry vol. 32(2), june 2020 effect of plasma 23 ftir spectra of each control, oxygen plasma treated and argon plasma treated specimens were obtained by placing the disk to be analyzed on a specified position inside the ftir analyzer. results surface roughness test results about the effect of plasma treatment on surface roughness of acrylic resin polymer specimens for the three groups (control, oxygen and argon plasma treated specimens) revealed an increase in the mean values of average surface roughness (ra) after the application of plasma treatment (oxygen and argon plasma treatments) compared with the control group (without plasma treatment) for the acrylic polymer specimens, as shown in figure 1 and tables 1and 2. figure 1: a polygon illustrating the mean values of surface roughness (μm) for the control, oxygen and argon plasma treated acrylic resin polymer specimens. table 1: anova test among acrylic polymer groups with different types of surface treatment. source d.f ss ms f pvalue factor 2 0.6019 0.3009 9.82 0.002 error 15 0.4599 0.0307 total 17 1.0618 p< 0.05 significant p> 0.05 non-significant p< 0.01 highly significant table 2: lsd between groups of acrylic polymer with different types of surface treatment. type of surface treatment p value sig. control vs. oxygen plasma treatment 0.216 ns control vs. argon plasma treatment 0.011 s oxygen plasma treatment vs. argon plasma treatment 0.027 s p< 0.05 significant p> 0.05 non-significant chemical surface analysis (ftir analysis) results of ftir analysis for 3 groups (control, oxygen and argon plasma treated acrylic resin polymer specimens) are shown in figures 2, 3 and 4, respectively. figure 2: ftir analysis of the control acrylic polymer specimen. figure 3: ftir analysis of oxygen plasma treated acrylic polymer specimen. 0 0.2 0.4 0.6 0.8 1 1.2 1.4 control o2 plasma treatment ar plasma treatment surface roughness mean values(μm) j bagh college dentistry vol. 32(2), june 2020 effect of plasma 24 figure 4: ftir analysis of argon plasma treated acrylic polymer specimen. discussion effect of application of the oxygen and argon plasma treatment on surface roughness. the results obtained in this study regarding the effect of application of the oxygen and argon plasma treatment on surface roughness of acrylic polymer specimens for the three groups (control, oxygen and argon plasma treated specimens) revealed that there was an increase in the mean values of average surface roughness (ra) after the oxygen and argon plasma treatment as compared with the control group. treatments with oxygen and argon gases (plasma modification processes) generate new chemical species on the surface of pmma due to the chemical reactions and physical sputtering (such as with ar plasma) with active gas-phase species. argon and oxygen plasmas have also been shown to participate in surface sputtering in addition to modification, resulting in the physical removal of material from the surface.(14) oxygen plasma treatment usually creates microroughness on the treated surface due to an etching effect.(15) effect of application of oxygen and argon plasma treatment on chemical surface analysis (ftir analysis) in the present study, ftir spectrum for oxygen plasma treated acrylic (pmma) specimen exhibited a surface rich in oxygen-containing groups (c-o-c, -oh, c=o), in addition to carbon-containing groups (ch aliphatic group) and (c=c). the broad peak represents the hydroxyl group (-oh) which appeared in ftir spectrum for the oxygen plasma treated group was an important chemical change which increased the hydrophilicity for the oxygen plasma treated acrylic (pmma) specimen. the hydroxyl functional group (-oh) is an important species because of its high chemical reactivity with respect to surface esters and it also increases hydrophilicity. (16) also the other functional groups such as oxygencontaining groups and carbon-containing groups have induced and activated the oxygen plasma treated surface toward further chemical reactions, so the surface might be oxidized (generating new chemical groups), and/or degraded as a result of an etching effect (chemical removal of surface material). ftir spectrums for control and argon plasma treated groups exhibited relatively the same peaks with no appearance of the hydroxyl (-oh) group in ftir spectrum for argon plasma treated group, which indicated that treatment with argon gas in the present study might induce little chemical changes on the surface of the argon plasma treated acrylic (pmma) specimen. conclusion application of oxygen and argon plasma surface treatment is an effective treatment method for enhancing surface roughness of acrylic resin denture base polymer material. oxygen plasma treatment can activate the treated surface towards further chemical reactions, and increase the hydrophilicity of the acrylic resin denture base polymer material. conflict of interest: none. references 1. kenneth j, anusavice. phillip’ science of dental materials: saunders; 2003. 2. lai j, sunderland b, xue j, yan s, zhao w, folkard m, michael bd, wang y. study on hydrophilicity of polymer surfaces improved by plasma treatment. appl surf sci. 2006; 252:3375-9. 3. johnson tj, ross d, gaitan m, locascio le. laser modification of preformed polymer microchannels: application to reduce band broadening around turns subject to electrokinetic flow. anal chem. 2001; 73: 3656-61. 4. mccarley rl, vaidya b, wei s, smith af, patel ab, feng j, murphy mc, soper sa. resist-free patterning of surface architectures in polymer-based microanalytical devices. j am chem soc. 2005 jan 26;127(3):842-3. 5. cheng jy, wei cw, hsu kh, young th. direct-write laser micromachining and universal surface modification of pmma for device development. sensors and actuators b: chem. 2004 apr 15;99(1):186-96. 6. johansson bl, larsson a, ocklind a, öhrlund å. characterization of air plasma‐treated polymer surfaces by esca and contact angle measurements for optimization of surface stability and cell growth. j app pol sci. 2002 dec 5;86(10):2618-25. 7. liu j, pan t, woolley at, lee ml. surface-modified poly (methyl methacrylate) capillary electrophoresis microchips for protein and peptide analysis. ana chem. 2004 dec 1;76(23):6948-55. j bagh college dentistry vol. 32(2), june 2020 effect of plasma 25 8. ponter ab, jones jr wr, jansen rh. surface energy changes produced by ultraviolet‐ozone irradiation of poly (methyl methacrylate), polycarbonate, and polytetrafluoroethylene. pol eng & sci. 1994 aug; 34 (16): 1233-8. 9. schroder, k., meyer-plath, a., keller, d., besch, w., babucke. g., ohl. a.. plasma-induced surface functionalization of polymeric biomaterials in ammonia plasma. contrib. plasma phys. 2001; 41: 562-572. 10. gröning p, collaud m, dietler g, schlapbach l. plasma modification of polymethylmethacrylate and polyethyleneterephthalate surfaces. j app phys. 1994; 76(2):887-92. 11. awad ak. evaluation of the effect of plasma on transverse strength surface roughness and candida adhesion of two types of acrylic denture base materials (heat cure and light cure). a master thesis, department of prosthodontics, college of dentistry, university of baghdad, 2012. 12. al-judy hj. effect of plasma treatment of acrylic denture teeth and thermocycling on the bonding strength to heat cured acrylic denture base material. j bagh coll dent. 2013; 25:6-11. 13. ahmed g. evaluation the effect of addition of plasma treated polypropylene fiber and silanized silicon dioxide nanoparticles composite on some properties of heat polymerized polymethylmethacrylate. a master thesis, department of prosthodontics, college of dentistry, university of baghdad, 2016. 14. clark dt, dilks a. esca applied to polymers. xv. rf glow‐discharge modification of polymers, studied by means of esca in terms of a direct and radiative energy‐ transfer model. journal of polymer science: pol chem ed. 1977 oct; 15(10): 2321-45. 15. cvelbar u, pejovnik s, mozetie m, zalar a. increased surface roughness by oxygen plasma treatment of graphite/ polymer composite. appl surf sci. 2003; 210: 255-261. 16. chai j, lu f, li b, kwok dy. wettability interpretation of oxygen plasma modified poly (methyl methacrylate). langmuir. 2004; 20 (25):10919-27. الخالصة الخلفية: سطوح البوليمر عادة تظهر مشاكل في الربط واالنهاءات بسبب انخفاض قابلية التبلل.كان الهدف من هذه الدراسةهو لتقييم تأثير ج المعالجة بالبالزما مع استخدام نوعين من الغازات )االوكسجين واآلركون(على خشونة السطح والتغييرات السطحية الكيميائية لبوليمر راتن ريل. االك ( ملم كعرض, ارتفاع, وطول بالتتابع قد حضرت لكل 30*2*8المادة والطريقة: ثالثة عينات من راتنج االكريل المصلب حراريا وبابعاد) فحص قد جرى في تلك الدراسة وقسمت ال مجموعة بدون معالجة بالبالزما ,مجموعة معالجة ببالزما االوكسجين , ومجموعة معالجة . اثنان فحوص جرت في الدرلسة, فحص خشونة السطح وفحص تحليل السطح الكيميائي. ببالزما اآلركون زما النتائج: تطبيق المعالجة بالبالزما زادت خشونة السطح لكال عينات راتنج االكريل لمجموعتي المعالجة ببالزما االوكسجين والععالجة ببال ع فرق معنوي عالي بين المجاميع. التحليل الكيميائي )اف.تي.أي .أر( لمجموعة اآلركون بالمقارنة مع مجموعة الغير معالجة بالبالزما م عينة راتنج االكريل المعالجة ببالزما االوكسجين اظهرت طيف مع قمة عريضة والتي تمثل مجموعة الهيدروكسيل والتي اعتبرت تغير ف.تي.آي.آر( لمجاميع عينات راتنج االكريل البدون معالجة بالبالزما كيميائي مهم ادى الى زيادة قابلية التبلل عند المقارنة مع اطياف ال )آ والمعالجة ببالزما اآلركون والتي اظهرت نسبيا نفس القمم مع تغيرات كيميائية قليلة . بوليمر قاعدة طقم االستنتاجات: تطبيق المعالجة ببالزما االوكسجين واآلركون كانت طريقة معالجة سطحية فعالة لزيادة خشونة السطح لمادة اه األسنان الراتنجي األكريلي . تحليل )أف . تي . آي . آر( الكيميائي اوجد ان المعالجة ببالزما األوكسجين قد فعلت السطح المعالج باتج .تفاعالت كيميائية اضافية وزادت قابلية التبلل لمادة بوليمر قاعدة طقم األسنان الراتنجي األكريلي mohammed.doc j bagh college dentistry vol. 27(1), march 2015 assessment of tongue oral diagnosis 117 assessment of tongue space area in a sample of iraqi adults with class i dental and skeletal pattern mohammed a. kadhum, b.d.s., m.sc. (1) abstract background: lateral cephalometric radiography is commonly used as a standard tool in orthodontic assessment and treatment planning. this study aimed to determine the tongue and surrounding space area in a sample of iraqi adults with class i dental and skeletal pattern. materials and methods: the study included thirty healthy subjects (15 males and 15 females) with an age ranged between 23-34 years and class i dental and skeletal pattern with no history of any sleep related disorders. the assessed cephalometric measurement included length and height of the tongue and position of hyoid bone from cervical line. descriptive statistics were obtained for the data. genders difference was evaluated by independent sample t-test. results: there were significantly higher values in males as compared to females in most of the measurements. conclusions: the study provides preliminary details of tongue space area assessment in normal class i profile subjects. keywords: tongue space, lateral cephalometrics. (j bagh coll dentistry 2015; 27(1):117-120). introduction tongue is the most agile, versatile appendage in the body. it is the largest organ of the oral cavity and has no skeletal bony base. peat (1) emphasized the role of tongue in positioning the dento-alveolar structure. the tongue forms a major part of upper airway and compromise of both extrinsic and intrinsic muscles (2). tongue form and size influence the shape and dimensions of airway between palate and tongue surface (3). cepholometry enables the analysis of dental and skeletal anomalies as well as soft tissue structures and forms (4). many studies in the past have assessed measurements of airway space and tongue size by means of cephalometry in subjects with obstructive sleep apnea in various malocclusions (5,6). this study was aimed to collect measurements of tongue and surrounding area representing position of hyoid bone in relation with tongue and cervical vertebra using lateral cephalometric analysis in a sample of iraqi adults with class i dental and skeletal pattern. materials and methods fifty students from college of dentistry, baghdad university accepted to enroll in this study. they were subjected to clinical examination to fulfill the inclusion criteria of this study. the inclusion criteria included having full permanent dentition regardless the third molars and class i dental and skeletal relation as indicated by angles' classification and two finger method of foster with no history of any related airway disorders like obstructive apnea. thirty students only fulfilled the inclusion criteria and proceeded to standardized digital true (1) assistant lecturer, department of oral diagnosis, college of dentistry, university of baghdad lateral cephalometric x-ray using planmeca proline cc 2002 with dimax 3 software. the subjects were positioned within cephalostat with frankfort plane horizontal and teeth in maximum intercuspation and instructed not to swallow during exposure. the digital images were analyzed using autocad 2007 software. firstly, the magnification was corrected using the rule of the nasal rod, then the cephalometric points, planes were determined and the linear measurements were obtained. cephalometric landmarks (14) 1. point tt: (tip of the tongue): the most anterior point of the tip of tongue. 2. point s: superior part of the tongue the most superior point on the dorsum of the tongue. 3. point v: (vallecula): junction of base of tongue with epiglottis. 4. point ah: the most anterior and superior point on the body of hyoid bone. 5. point po: the highest point on the superior surface of soft tissue of the external auditory meatus. 6. point or: the lowest point on the average left and right borders of the bony orbit. 7. point a: the deepest point on the concave outline of the upper labial alveolar process on the frontonasal suture. 8. point b: the deepest point on the bony curvature between the crest of alveolus and the pogonion point. 9. point n: anterior point on the frontonasal suture. cephalometric planes: 1. frankfort plane (fp): the line runs from orbitale to porion ,it represent the ideal horizontal position of head when patient stand erect. j bagh college dentistry vol. 27(1), march 2015 assessment of tongue oral diagnosis 118 2. cervical line (cl): the line overlying the anterior surface of second and third cervical vertebrae linear measurements 1. v-tt: distance from tip of tongue to base of tongue and represent tongue length. 2. th: tongue height from s point perpendicular to vtt. 3. v-fp: the line from v perpendicular to fp. 4. v-cl: the line form v to cl parallel to fp 5. ah-fp: line from tip of anterior of hyoid to and perpendicular on frankfort plane. 6. ah-cl: line from tip of anterior of hyoid to cervical line parallel to frankfort plane. 7. tongue area: the area formed by the line encircling the tongue boundaries passing through tip of the tongue, s point and v point. figure 1: linear measurements and area of tongue. statistical analyses all the data of the sample were subjected to computerized statistical analysis using spss version 19 computer program. the statistical analysis included: 1. descriptive statistics: means and standard deviations. 2. inferential statistics: independentsamples t-test for the comparison between both genders in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results as indicated in table 1, the results showed that the vertical and horizontal measurements of vallecula and hyoid bone and tongue area were higher in males than in females with a highly significant difference. table 1: descriptive statistics and genders difference for the measured variables variables genders descriptive statistics genders difference (d.f.=28) n mean s.d. min. max. mean difference t-test p-value v-tt (mm.) males 15 76.08 4 69.35 82.9 7.71 7.02 0.000 (hs) females 15 68.38 1.44 66.2 70.7 th (mm.) males 15 33.46 1.84 30.52 36.5 4.53 7.77 0.000 (hs) females 15 28.93 1.31 26.67 31 v-fp (mm.) males 15 80.52 4.05 73.8 87.9 10.97 6.74 0.000 (hs) females 15 69.55 4.83 60.5 77.7 v-cl (mm.) males 15 19.98 2.45 15.23 23.8 3.53 4.80 0.000 (hs) females 15 16.45 1.45 14.12 18.6 ah-fp (mm.) males 15 87.32 4.29 81.45 94.6 14.79 8.35 0.000 (hs) females 15 72.53 5.35 63.3 80.7 ah-cl (mm.) males 15 34.14 2.78 27.2 38.1 6.47 7.05 0.000 (hs) females 15 27.67 2.21 24.21 30.9 t-area (mm2.) males 15 2551.67 77.31 2398 2672 383.07 13.78 0.000 (hs) females 15 2168.60 74.89 1990 2293 j bagh college dentistry vol. 27(1), march 2015 assessment of tongue oral diagnosis 119 discussion the lateral cephalogram is a two dimensional image showing the sagittal aspect of head and neck region and usually used for orthodontic treatment. maltais et al (8) had opined that the use of cephalometric radiographs to assess the upper airway anatomy is helpful because it is simpler than other methods for measuring airway patency. parkkinen et al (12) confirmed in their study that lateral cephalogram is a valid method for measuring dimensions of nasopharangeal and retropalatal region. the present study included a group of iraqi subjects with clinically normal dental and skeletal relations, any reported abnormality of upper airway were excluded from this study. similar studies have been conducted on normal adults in various populations (7,10). the length of the tongue sagittally, height of the tongue measured from the highest point on the dorsam of the tongue and perpendicularly on vtt line ,vertical and horizontal distance of vallecula and hyoid bone from cervical line horizontally and frankfort line vertically were larger in male than in females. the results of the study by samman et al (7) to evaluate normative data in hong kong chinese subjects were correlated with this study. the present study showed that the length of tongue and tongue area in normal males subjects were comparatively of larger dimensions with respect to normal indian males guttal et al (10) and smaller dimensions with respect to normal hong kong chinese males samman et al (7). in the study of battagel et al (9) the tongue area in normal caucasian males subjects was 4120mm2. however in the present study the tongue area among normal iraqi male subjects was 2551mm2, implying that the tongue area in normal iraqi males was comparatively of smaller dimension with respect to normal caucasian males and normal hong kong chinese males. in the study by tsai et al (11) on normal taiwanese subjects, the position of hyoid bone in horizontal plane correlate with the results of the present study. the cephalometric norms of different ethnic and racial groups established in various studies. most investigators have concluded that there are significant differences between ethnic and racial groups, and cephalometric standards have been developed for specific ethnic and racial groups (13). in this study, the vertical and horizontal distances of vallecula and hyoid bone were larger in male than in females so that they are more inferiorly and anteriorly positioned in men. the present study also signifies the importance of the use of cephalometry for the assessment of oral and surrounding structures. the cephalometric measurements in this study group can be used as normative data for future studies. further correlation can be drawn with studies comparing tongue and surrounding space dimensions in normal individuals and in subjects with sleep related disorders. table 2: normative data of different studies variables genders present study guttal et al samman et al battagel et al v-tt (mm.) males 76.08 71.15 72.0 females 68.38 66.86 64.8 s-tt (mm.) males 33.46 32.4 36.9 females 28.93 27.8 32.9 v-fp (mm.) males 80.52 77.6 91.2 females 69.55 68.4 78.9 v-cl (mm.) males 19.98 15.8 23.0 females 16.45 11.8 20.4 ah-fp (mm.) males 87.32 79.3 92.4 females 72.53 70.5 78.5 ah-cl (mm.) males 34.14 30.0 36.4 females 27.67 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(ivsl). 13. nanda r, nanda rs. cephalometric study of dentofacial complex of north indians. angle orthod 1969; 39: 22-8. (ivsl). 14. carla e, carlos t, mirian nm. dental skeletal dimension in growing individuals with variations in the lower facial height. braz dent j 2004; 15: 68-74. الخالصة علم تقویم التصویر الشعاعي بواسطة صورة االشعة الراسیة الجانبیة یعتبر من االدوات االساسیة المعروفة التي تستخدم في التحلیالت المستخدمة في :الخلفیة عن اللسان والمنطقة المحیطة باللسان في ) نقطة الرأس م( ان ھذة الدراسة تھدف الى الحصول على معلومات راسیة . االسنان و وضع الخطط العالجیة فیھ .االشخاص البالغین الطبیعیین سنة 34 – 23بالغین ومتوسط عمري یتراوح من صحاءالشخاص ا) اناث 15ذكور و 15( الدراسة تتضمن ثالثین صورة اشعة راسیة رقمیة :المواد والطریقة .النوم مشاكل تنفسیة اثناءعدم وجود اي تاریخ الي ویمتلكون التصنیف االول للمظھر الجانبي مع .وجود دالئل احصائیة بین الذكور واالناث بالنسبة لجمیع القیاسات :النتائج .ي ان ھذة الدراسة قدمت لنا معلومات جیدة عن وضعیة اللسان واالجزاء المحیطة بھ في االشخاص البالغین ذو التصنیف االول للمظھر الجانب :االستنتاج sabaa f1.doc j bagh college dentistry vol. 27(3), september 2015 establishment of the oral diagnosis 85 establishment of the possible association between the presence of helicobacter pylori in the saliva and gastric biopsy by using polymerase chain reaction technique in association with oral manifestation of peptic ulcer disease sabaa r. thamer, b.d.s. (1) sahar al-ani, b.d.s., m.sc., ph.d. (2) abstract background: helicobacter pylori are important gastrointestinal pathogen associated with gastritis, peptic ulcers, and an increased risk of gastric carcinoma. there are several popular methods for detection of h. pylori (invasive and non-invasive methods) each having its own advantages, disadvantages, and limitations, and by using pcr technique the ability to detect h. pylori in saliva samples offers a potential for an alternative test for detection of this microorganism. materials and methods: the study sample consists of fifty participants of both genders, who undergo oesophageogastrodudenoscopy at the gastroenterology department of al-kindy teaching hospital baghdad/ iraq, during five months period from january 2014 to may 2014. they were grouped into 32 participants with pud (case group) and 18 healthy participants (control group). a full-mouth examination was performed for every patient; saliva and gastric samples from both groups were obtained. helicobacter pylori were detected in gastric biopsies by histological examination by using h & e stain, and polymerase chain reaction (pcr) was carried out on the oral samples. results: helicobacter pylori dnawas determined by pcr in oral samples in 88% patients and in gastric biopsies by histology in 86% patients, and in both samples in 84% patients.it was highly significant to find simultaneous presence for those have h. pylori in stomach also have such microorganism in the mouth p < 0.05 and there was an excellent correlation between detecting h. pylori simultaneously in both stomach and mouth. if we screen for stomach h. pylori through detecting this microorganism in the mouth; saliva samples is highly sensitive (98%) but not very specific. conclusion: helicobacter pylori saliva test has high sensitivity, specificity, and accuracy for the diagnosis of h. pylori infection in iraqi population. the test can be clinically applied as a routine diagnostic tool for h. pylori infection this could permit not only a target for therapeutic procedures but also a monitoring tool for the efficacy of therapy. it seems to overcome some limitations of the conventional invasive techniques. key words: helicobacter pylori oral infection h. pylori saliva test – pud. (j bagh coll dentistry 2015; 27(3):85-88). introduction peptic ulcer is a breach in the gastric or duodenal mucosa down to the sub mucosa (1). in most cases the etiology of ulcer is unknown yet (2).the normal stomach mucosa maintains a balance between protective and aggressive factors. some of the main aggressive factors are gastric acid, abnormal motility, pepsin, bile salts, use of alcohol and non-steroidal antiinflammatory drugs (nsaid), as well as infection with microorganisms (helicobacter pylori) (3). the association of h. pylori with peptic ulcer disease has been observed (4). this study has been shade light on the role of (h. pylori) as the commonest bacterial infection worldwide, it infects more than 50% of the worlds’ population (5), and as a main cause of pud (6).helicobacter pylori first reported in 1983 by warren and marshall, (7). h. pylori (initially termed campylobacter pyloridis) is an important human pathogen (8). (1)master student, department of oral diagnosis, college of dentistry, baghdad university. (2)assistant professor, department of oral diagnosis, college of dentistry, baghdad university. h.pylori is a gram-negative spiral bacterium that may colonize the human gastric mucosa and establish a life-long infection (9). colonization with h. pylori is not a disease by itself (10). it has been shown that infection certainly makes the occurrence of ulcers more likely, infection linked with the development of chronic gastritis, peptic ulcer, gastric cancer, and mucosa-associated lymphoid tissue lymphoma (11,12). because of the importance of this bacterium in the development of pud, rasmussen (13) evaluated the association between the presence of h. pylori in gastric biopsies and in the saliva of the same individuals. the relationship between gastric symptoms and h. pylori dna in saliva, however, is unclear. it could be possible that the oral cavity is the initial site of infection (14). many diagnostic methods have been developed to detect h. pyloriincluding the urea breathtests, rapid urease tests, and measurement of anti-h. pylori antibody from serum and urine, special histologic staining and immunostaining, and stool antigen testing. many pcrmethods targeting putative h. pylori specific genes have also been reported (15,16).the goal of this study was todetermine the simultaneous presence of h. j bagh college dentistry vol. 27(3), september 2015 establishment of the oral diagnosis 86 pylori both in the oral cavity and gastric mucosa in patients suffering from pud and to standardize a feasible non-invasive method for the rapid diagnosis of h. pylori in salivary secretion of infected patients suffering from pud by using pcr analysis. materials and methods the study sample consists of fifty patients of both genders with age range (15-65) years; who undergo oesophageogastrodudenoscopy during five months period from january 2014 to may 2014. they were grouped into 32 participants with pud (case group) and 18 healthy participants (control group). • inclusion criteria: symptomatic individuals were selected and these criteria were: recurrent abdominal pain, unexplained vomiting and weight loss (17). • exclusion criteria: gastritis patients, gastric ca, history of pud, patients receiving antibiotics, h2 receptor antagonists or anti-acid treatment, were excluded (17). after informed consent was obtained from all participants, full-mouth examination was performed foreach patient; saliva and gastric sampleswere collected from cases (whom diagnosed endoscopicaly by a specialist) and from healthy subjects (endoscopicaly no signs of pus disease). subjects were investigated for the presence of h. pylori in saliva and stomach biopsies, (18). helicobacter pylori detected in gastric biopsies by histological examination, by using hematoxylin and eosin stain (h & e), whilepolymerase chain reaction (pcr) was carried out on the saliva.the lab work for the detection of h. pyloriwas done in a strictly asepsis conditions. dna extraction: dna was extracted from the saliva using qiaamp® dna mini kit (germany) with a bacterial dna extraction protocol (spin protocol): samples preserved in freeze thawed into room temperature then 200 μlsaliva pipeted in to a microcentrifuge tube, then20 μl of proteinase k added then200 μllysis buffer (buffer al) added to the mixture, thenthe mixture incubated at 56°c for 10 min.the mixture was then combined with 200 μl ethanol and mixed by pulse-vortexing. the mixture was applied to the qiaamp mini spin column which holds a silica gel membrane, and spun at 8000 r/m (round/minute) for 1 minthen the spin column washed with 500 μl of buffer aw1 and then aw2 by centrifugation at 14,000 r/mfor 1 and 3 minutes respectively, pure dna bounded on a membrane eluted by 200 μl of buffer ae added and centrifuged for 1 min, then incubated at room temperature (15-25°c) for 5 minute. finally the resulting dna extracts stored at -20°c until pcr assessment. dna amplification and gel electrophoresis: extracted dna from saliva samples were amplified by using primerfor urease gene ure c (136 bp) 5' – aagcttttaggggtgttaggggttt – 3' and 5' – cgcaatgcttcaattctaaatcttg – 3' indicative of h. pylori infection, which have been shown previously to be highly specific and sensitive, (19), and by using gotaq® green master mix kit (a premixed ready-to-use solution containing bacterially derived taq dna polymerase, dntps, mgcl2 and reaction buffers at optimal concentrations for efficient amplification of dna templates by pcr), the gotaq® green master mix thawed into room temperature then the reaction mixture prepared in a final volume of 50 μl. then the reactions placed in a thermal cycler.dna amplification was carried out as follow: denaturation at 94°c for 5 minutes in the first cycle, followed by annealing for 30 seconds at 60°c, extension for 2 minutes at 72°c, and denaturation for 30 seconds at 94°c for a total of 40 pcr cycles.the extension for the last cycle was increased to 5 minutes to ensure complete extension of the amplified fragment. the pcr products were resolved by 2% agarose gel electrophoresis and were visualized after ethidium bromide (0.5 mg/ml) staining, using an uv transilluminator and photographed by polaroid camera. results the present study was carried out on 50 patients, 29 males and 21 females, their age ranged from (15-65) years. among study groups (50) samples from oral cavity (saliva) and (50) samples from stomach (gastric biopsy) from the same individuals were collected, h. pylori was detected in 84% patients simultaneously in both types of samples. this study reported that there was an excellent agreement between detecting h. pylori simultaneously in both stomach and mouth {k > 0.70, p < 0.05, table 1 a}. if we screen for stomach h. pylori through detecting this microorganism in the mouth; saliva samples is highly sensitive (98%) but not very specific (70%) (table 1b). j bagh college dentistry vol. 27(3), september 2015 establishment of the oral diagnosis 87 table 1: results of detection of h. pylori in gastric and saliva samples: a) results of statistical tests statistical test output fisher's exact test p value < 0.001 measurement of agreement kappa = 0.735 p < 0.001 b) results of diagnostic values if using oral sample to screen for h. pylori in stomach. indicator of test performance p value 95%ci [upper; lower] sensitivity 0.98 [0.86; 1.00] specificity 0.71 [0.30; 0.95] accuracy 0.94 [0.82; 0.98] ppv 0.95 [0.83; 0.99] npv 0.83 [0.36; 0.99] also the current study found that presence of h. pylori in saliva was significantly associated withgingival inflammation and halitosisp < 0.05. but no significant associations with teeth erosion, burning mouth syndrome (bms), oral aphthous p > 0.05. also there was highly significant correlation between presence of h. pylori in saliva and pud group p < 0.001 (figure 1). figure 1: distribution of study sample according to study group and to presence of h. pylori in saliva. discussion in this study, h. pylori was identified simultaneously in both kinds of samples (gastric biopsy and in saliva) for 84% participants.the present findings showed statistical significance of the positive relation of h. pylori in gastric biopsiesand oral samples, these results coincide with that reported by miyabayashi (20) and rasmussen (13), indicating that in many cases, patients with positiveresults of gastric biopsies were also positive in oral samples. in this study, the h. pylori saliva test had a high sensitivity 98%, which enabled it to detect a low titer of h. pylori, but it's not very specific 71%, this finding agree with a study reported by song (21). also the finding showed particular attention is paid to the association of the h. pylori reservoir in the oral cavity with gingivitis, this finding agrees with cellini (22). it is also suspected that the presence of this bacteria in pud patients may lead to oral inflammation and the formation of gingival/periodontal pockets, which develop favorable conditions for bacterial growth (23).the findings of this study support the concept of a potential association between halitosis and the presence of h. pylori in the oral cavity, this findings is highly similar to that reported by moshkowitz (24) and suzuki (25). the finding show no significant association between h. pylori presence in saliva and dental erosion, this may be explained by the fact that dental erosion doesn’t occur until gastric acid had acted on the dental hard tissue regularly over a period of several years. in agreement with studies of other researchers (26,27). the present study showed no significant relation between h. pylori and burning mouth syndrome.at variance to other trial, reported by idan and abdul-razaq (28), found highly statistical significant relationship between h. pylori and burning mouth. the findings suggest that salivary h. pylori does not play a role in the pathogenesis of rau, in agreement with ghanaei (29) found that these bacteria not involved as a cause of recurrent oral aphthous ulcers because h. pylori dna could not be found in the aphthous ulcers of these patients. in conclusion there is strong relation between presence of h. pylori in stomachand oral cavity, itwas identified simultaneously in both kinds of samples, in gastric biopsy histologically and in saliva by pcr.the successful detection of h. pylori dna directly from saliva samples indicates that this approach is feasible and saliva could serve as an effective and valuable noninvasive specimen to diagnose and monitoring the efficacy of therapy in patients with active h. pylori infection. this method not only reduces the economic burden of treatment, but also lowers the risk of increasing the resistance of h. pylori to antibiotics. p er ce n t % j bagh college dentistry vol. 27(3), september 2015 establishment of the oral diagnosis 88 references 1. majumdar d, bebb j, atherton j. helicobacter pylori infection and peptic ulcers. medicine 2007; 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(1) fadi al-hano, b.d.s., m.sc. (2) abstarct background: one of the complications of power bleaching is surface roughness of enamel which increases the possibility of post bleaching teeth discoloration. the aim of the present study is to evaluate the effect of toothpaste containing nano hydroxyapatite, novamin and kin sense fluoride on surface roughness of human tooth enamel after laser bleaching with 35% hydrogen peroxide bleaching gel. materials and methods: twenty human enamel incisors were cleaned and their labial surface polished up to #1200, then categorized into four equal groups; first group kept without bleaching as a control group, while the remaining three experimental groups were bleached with 35% hydrogen peroxide, and each group treated with a restore paste containing one of the following: nano hydroxyapatite, novamin, and kin fluoride. bleaching was done with laser hybrid system (dmc whitening lase ii, sao paulo, brazil). enamel roughness values assessed by an atomic force microscopy (aa3000, bosten, usa) before and after treatment with restore tooth paste. results: paired t-test used to compare the mean roughness values before and after treatment with each restore paste. one-way analysis of variance and duncan post hoc tests used to determine the differences between mean roughness values of the groups. a p-value of 0.05 or less considered a significant. the results showed a highly significant statistical differences of remineralization of all types of restore tooth pastes. conclusions: nano hydroxyapatite past exhibiting a higher ability to reduce the surface roughness after laser bleaching than other tested pastes. keywords: laser bleaching, remineralization, surface roughness, enamel. (j bagh coll dentistry 2015; 27(4):1-7). introduction tooth whitening is a highly desirable esthetic treatment, as the tooth color is one of the most important factors related to the patients' satisfaction with their appearance (1). dental bleaching treatments are mainly based on the action of hydrogen peroxide, which is able to penetrate the tooth structure and release free radicals, oxidizing the chromophores molecules (2). such molecules are mainly organic, although inorganic molecules can also be affected by these reactions. nevertheless, the free radical reaction is not specific and it may also alter the organic component of enamel (3). since the organic content contributes to the integrity of enamel, different adverse effects on both mineral and organic parts of bleached enamel have been observed (4). alterations in enamel surface morphology(5-7), chemical composition(8-9) and microhardness values(2,10), after previous reporting of bleaching. furthermore, some changes in bleached enamel were also described as slight erosive effects promoted by the bleaching agent(11). nevertheless, some authors claim that the erosive pattern on the surface of bleached enamel only occurs when bleaching gels with low ph are used(12,13). (1) head of school of dentistry, faculty of medical sciences, duhok university, iraqi kurdistan region. (2) assistant lecturer. department of conservative dentistry, college of dentistry, university of mosul. attempts to minimize the adverse effects of bleaching treatments by increasing enamel remineralization have been conducted, however, the results are contradictory(14). the association between the bleached enamel surface alterations and the subsequent susceptibility to erosive lesions resulting from the contact of bleached enamel with demineralizing solutions has been reported. the application of carbamide peroxide gel rendered enamel more susceptible to demineralization(15). in other studies, at-home bleaching technique did not increase the susceptibility of enamel to erosion(16). however, the effect of at-office bleaching agent (35% hp) on the enamel susceptibility to erosion that has not been properly discussed. considering the possibility that bleaching gels with high concentration of hp could increase the susceptibility of enamel to erosion, the addition of remineralizing ions into bleaching gels would be beneficial for preventing a further enamel demineralization (17). therefore, the objective of in vitro study was to evaluate the effect remineralizing tooth pastes gel on the bleached enamel with 35% hydrogen peroxide. materials and methods preparation of the samples twenty extracted non-damaged and intact human incisors were stored in a 0.1% thymol solution and refrigerated at 4◦c, until required. j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 2 enamel samples prepared from the labial surface of the tooth using a diamond disc with straighttype micro motor handpiece (nsk, tokyo, japan) under coolant (fig. 1). labial surfaces were polished to create a smooth and flat enamel surface with ascendinggrit water proof silicon carbide papers starting from #400 up to #1,200 under running water. the specimens were immersed in deionized water and placed in an ultrasonic bath for 10min (ultrasonic cleaner, odontobras, ribeirao preto, brazil) for the removal of all waste, and then stored in thymol solution at 0.1% for rehydration. fig. 1. crosscut surface of the prepared specimen. bleaching procedures the specimens were randomly assigned into four groups each comprising 5 enamel samples. one of the group was kept non-bleached as control, while the other three experimental groups were bleached with 35% hydrogen peroxide, before treated with nano hydroxyapatite (nhap), novamin and kin fluoride toothpastes. after polishing procedure, the polished specimens covered with a masking tape of 5 mm-diameter to ensure measuring the same area of ra value for polished, bleached and treated specimens with restore toothpastes (fig. 2). the bleaching procedure was performed using whitening lase ii, dmc (810nm wavelength diode laser mix with led). according to the manufacturer, the specimens rinsed with deionized water to remove the bleaching agent (20 sec). surface roughness after completion of bleaching process with 35% at office laser bleaching, the surface roughness ra value was calculated for all bleached specimens. such evaluation conducted by noncontact method using afm (aa3000, angstrom advanced inc. usa) through application of restore pastes according to the sample size to all bleached enamel sample by small brush with gentle brushing motion for 5 min, then washed and dried and ra value calculated again for all treated enamel specimens for all groups. the differences in average (ra) values between bleached and reminerlized enamel surface for each specimen were recorded and analyzed. statistical analysis data analyzed with spss program version 21, 2013. paired t-test used to compare the mean ra before and after treatment with each restore paste. one-way analysis of variance and duncan post hoc test used to determine differences in mean roughness values among the groups. the level of statistical significance was a p-value ≤ 0.05. j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 3 fig. 2. a: specimens of polished enamel up to 1200#. b: specimen with masking tape with a 5mm-diameter hole. c: specimen bleached with 35%h2o2 laser bleaching (dmc). d:specimen treated with restore tooth pastes. results table1 and figure 3 shows the mean, standard deviation and standard error of all groups after bleaching and treatment with restore tooth pastes. a paired t-test used to assess whether there were any differences between pre & post treatment for each of the experimental groups. the results of roughness value were statistically analyzed as shown in table 2. table 1: study groups by mean roughness value before and after treatment with restore paste. study groups n mean ra value s.d. s.e. nhap (a)* 5 37.340 0.427 0.191 nhap (b)* 5 16.420 0.389 0.174 nov (a) 5 37.300 0.529 0.236 nov (b) 5 27.800 0.380 0.170 kin fluoride (a) 5 37.120 0.729 0.326 kin fluoride (b) 5 31.840 0.792 0.354 control 5 18 (a)* before treatment, (b)* after treatment j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 4 fig. 3. study groups by mean (ra) before and after treatment with restore paste table 2: summary statistics comparing mean roughness value before and after treatment with restore paste study groups t-test d.f. sig. (2 tailed)* nhap (pre)nhap (post) 284.685 4 0.000 nov (pre)nov (post) 35.161 4 0.000 kin (pre)kin (post) 7.833 4 0.001 *based on paired t-test table 3: differences between the groups using one-way analysis of variance and post hoc duncan test. sum of squares d.f. mean square f-test sig. between groups 2460.030 6 410.005 1494.810 0.000 within groups 7.680 28 0.274 total 2467.710 34 fig. 4. different letters indicated significant changes in surface roughness value. j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 5 afm results the atomic force microscopy investigates the surface topography for all treated groups with various mean peak-to-valley height as show in figures (5-9). fig. 5. 3d surface topography/ control ra value = 18 nm. fig. 6. 3d surface topography/ post fig. 7. 3d surface topography/post treatment bleaching with 35% h2o2, ra value = 37.2 nm with nhap ra value = 16.4 nm fig. 8. 3d surface topography/post treatment with nov. ra value = 28.2 nm. discussion bleaching has become a popular procedure with seeking improvements in the perceived appearance of their teeth(18). the effects of conventional bleaching using high concentrations of hydrogen peroxide on enamel’s surface widely discussed in the literature, still presents conflicting results (19). some studies have claimed that there are no significant effects of bleaching agents on human fig. 9. 3d surface topography/post treatment with kin sensi. ra value = 32.6 nm. j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 6 enamel(20). however, other studies have obtained contradictory results, with treated enamel showing morphological changes suggesting that bleaching is an erosive process(21,22). bleaching directly affects the organic (protein) content of the tooth, but this leads to changes in the mineral phase, resulting in the observed morphological changes to the tooth surface (4). it may be possible to reverse this damage by the development of mineralizing agents to treat the affected tooth surface which are capable of bonding chemically to hard dental tissues such as oxides of calcium, sodium, phosphorous and silica in ratios that imparts bioactivity (23). in the present study afm/spm used for determination of enamel surface texture as noncontact method, it is useful to study the surface texture at different magnification powers. also, it provides a 3d images and roughness value for specimens. the mean (ra) values obtained after bleaching was (37.2 nm) approximately for all specimens. this can be explained by the fact that the enamel surface structure is composed of hydroxyapatite crystals and each crystal of ca10 (po4)6(oh)2 is surrounded by a layer of tightly bound water. the presence of this hydration shell makes the crystal electrically charged and can therefore attract ions. free radicals emitted from hydrogen peroxide during bleaching are able to play a part in demineralization and cause ca+2 loss from enamel crystal, and this matches with the findings of lewinstein et al(24) who concludes that peroxide could cause demineralization in enamel at low and high concentrations. another study concludes that higher concentrations of hydrogen peroxide caused more ca+2 losses than lower concentrations(18), this is also in accordance to the current study. atomic force microscopy reveals that exposing bleached enamel surface to different remineralizing restore pastes showed reduced surface roughness with significant differences between all groups. hydroxyapatite is the main component of enamel that gives the tooth a bright white appearance and eliminates the diffused reflection of light by filling up the fine pores of the tooth surface. accordingly, remineralization of the teeth can be expected and its effect will be increased when the particle size of hydroxyapatite can be reduced to less than that of the micron-size in existing toothpaste preparations. hydroxyapatite materials discovered to have remineralizing effects on the altered enamel surface, helping in the recovery of teeth microfractures increasing teeth brightness and whiteness. it is reported that the remineralization effect is increased if the particle size of hydroxyapatite is reduced down to the nanometric range(19). indeed, the interaction of nanoparticles with dentine and enamel is more effective, due to the increased surface to volume ratio(25). the results illustrate that the 3d surface topography/post treatment with nhap ra value (16.4 nm) is even less than the ra value in the control group which is (18nm), this might be due to the nano-hydroxyapatite ability of being deposited in the cavities and defects of enamel surface(26) enhance smoothness. as the particle of nano-hydoxyapatite is fairly small sized, it can enter into the enamel surface continuously and fill the vacant position of enamel crystal. although it is very dense, partial penetration of certain ions and molecules through the enamel structure is possible because it contains small and intercrystalline spaces, rod sheaths, enamel cracks, and other defects(27,28). roveri et al.(29) notices a thick and homogeneous apatitic layer covers the surface of the demineralized enamel after treatment with hydroxyapatite nanocrystals. the conclusion of the present study is that nano-hydroxyapatite had exhibit a higher ability to reduce the surface roughness after laser bleaching than other tested pastes. it is recommended to use it following laser bleaching to reduce the possible alteration on enamel surface. references 1. geiger sb, samorodnitzky-naveh gr, levin l. patients’ satisfaction with dental esthetics. j am dent asso 2007; 138(6): 805–8. 2. sulieman ma. an overview of tooth-bleaching techniques: chemistry, safety and efficacy. periodontol 2000; 48(1): 148-69. 3. jiang wt, ma x, et al. investigation of the effects of 30% hydrogen peroxide on human tooth enamel by raman scattering and laser-induced fluorescence. j biomedicaloptics 2008; 13(1): 014019. 4. hegedus c, bistey t, flora-nagy e, keszthelyi g, jenei a. an atomic force microscopy study on the effect of bleaching agents on enamel surface. j dent 1999; 27: 509–15. 5. borges ly, samezima lp, fonseca kck, yui al, borges s, torres crg. influence of potentially remineralizing agents on bleached enamel microhardness. operative dentistry 2009; 34(5): 5937. 6. turkun mf, sevgican y, pehlivan, aktener bo. effects of 10% carbamide peroxide on the enamel surface morphology: a scanning electron microscopy study. j esthetic and restorative dentistry 2002; 14(4): 238-44. 7. jiang wt, ma x, et al. investigation of the effects of 30% hydrogen peroxide on human tooth enamel by raman scattering and laser-induced fluorescence. j biomedicaloptics 2008; 13(1): 014019. j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 7 8. efeoglu nd, wood j, efeoglu c. thirty-five percent carbamide peroxide application causes in vitro demineralization of enamel. dental materials 2007; 23(7): 900–4. 9. mccracken ms, haywood vb. demineralization effects of 10 percent carbamide peroxide. j dentistry 1996; 24(6): 395-8. 10. lewinstein i, hirschfeld z, stabholz a, rotstein i. effect of hydrogen peroxide and sodium perborate on the microhardness of human enamel and dentin. j endod1994; 20: 61–3 11. ushigome t, takemoto s, hattori m, yoshinari m, kawada e, oda y. influence of peroxide treatment on bovine enamel surface—cross-sectional analysis. dental materials j 2009; 28(3): 315–23. 12. sulieman m, addy m, macdonald e, rees js. a safety study in vitro for the effects of an in-office bleaching system on the integrity of enamel and dentine. j dentistry 2004; 32(7): 581–90. 13. li ox, wang y. effects of ph values of hydrogen peroxide bleaching agents on enamel surface properties. operative dentistry 2011; 36(5): 554–62. 14. oliveira r, de af, leme p, giannini m. effect of a carbamide peroxide bleaching gel containing calcium or fluoride on human enamel surface microhardness. brazilian dental j 2005; 16(2): 103-6. 15. attin t, kocabiyik m, buchalla w, hannig c, becker k. susceptibility of enamel surfaces to demineralization after application of fluoridated carbamide peroxide fels. caries res 2003; 37(2): 93– 9. 16. engle k, hara at, matis b, eckert gj, zero dt. erosion and abrasion of enamel and dentin associated with at-home bleaching. j am dent asso 2010; 141(5): 546–51. 17. chen hp, chang ch, liu jk, chuang sf, yang jy. effect of fluoride containing bleaching agents on enamel surface properties. j dentistry 2008; 36(9): 718–25. 18. tezel h, atalayin c, erturk o, karasulu e. susceptibility of enamel treated with bleaching agents to mineral loss after cariogenic challenge. international j dentistry 2011, article id 953835, 8 pages. 19. freitas de, botta r, teixeira f, salvadori m, netto n. microscopic effects of fluoride or nanohydroxiapatite on roughness and gloss of bleached teeth. microsc res tech 2011; 74:1069–75. 20. ernst cp, marroquin bb, willershausen-zo¨ nnchen b. effects of hydrogen peroxide-containing bleaching agents on the morphology of human enamel. quintessence int 1996; 27:53– 56. 21. ledoux wr, malloy rb, hurst rv, mcinnes-ledoux p, weinberg r. structural effects of bleaching on tetracycline-stained vital rat teeth. j prosthet dent 1985; 54: 55–9. 22. shannon h, spencer p, gross k, tira d. characterization of enamel exposed to 10% carbamide peroxide bleaching agents. quintessence int 1993; 24: 39–44. 23. gjorgievska e, nicholson jw. prevention of enamel demineralization after tooth bleaching by bioactive glass incorporated into toothpaste. australian dent j 2011; 56: 193–200. 24. lewinstein i, fuhrer n, churaru n, cardash h. effect of different peroxide bleaching regimens and subsequent fluoridation on the hardness of human enamel and dentin. j prosthetic dentistry 2006; 92: 337–42. 25. generosi a, rau jv, albertini rv. crystallization process of carbonated substituted hydroxyapatite nanoparticles in tooth pastes upon physiological conditions: an in situ time-resolved x-ray diffraction study. j mater sci mater med 2010 21: 445–50. 26. lv k, zhang j, meng x li x. remineralization effect of the nano-ha toothpaste on artificial caries. key eng mater 2007; 330– 332: 267–270. 27. tanaka r, shibata y, manabe a, miyazaki t. microstructural integrity of dental enamel subjected to two tooth whitening regimes. arch oral biol 2010; 55: 300–8. 28. yamagishi k, onuma k, suzuki t, okada f, tagami j, otsiki m senawangse p. a synthetic enamel for rapid tooth repair. nature 2005; 433: 818. 29. roveri n, battistella e, bianchi cl, foltran i, foresti e, iafisco m, lelli m, naldoni a, palazzo b, rimondini l. 2009. surface enamel remineralization: biomimetic apatite nanocrystals and fluoride ı´ons different effects. j nanomater 2009(8), doi:10.1155/2009/746383. j bagh college dentistry vol. 31(3), september 2019 prophylactic antibiotics 17 the role of prophylactic antibiotics in compound facial fractures treated by closed and open reduction thamir y. hammadi b.d.s (1) thair abdul lateef b.d.s., h.d.d.,fibms (2) abstract background: the role of prophylactic antibiotics remains controversial. it is clear that actively facial fractures are considered as clean contaminated and should be treated with therapeutic antibiotics; however, there is widespread variability in the use, type, timing, and duration of prophylactic antibiotic administrated in practice today. there is an adverse effect of increased antibiotic resistance, as well as costs, it is important to review the current evidence for the role of prophylactic antibiotics in compound facial fractures. the purpose of this study is to evaluate the role and significance of preoperative, perioperative and postoperative antibiotic prophylaxis for patients when there is already an infective focus, such as compound facial fracture. materials and methods: a total of 70 iraqi patients aged 4-65 years, 50 males and 20 females who met the eligibility criteria were enrolled in this study to evaluate the infection rate in patients who have sustained compound facial fractures treated by open or closed treatment. the patients were divided into two groups, group a included 50 patients who received pre, peri and postoperative antibiotics. postoperatively the antibiotics utilized in two different regimen timing. in group b antibiotics were administrated peri and post-operatively for 20 patients. they were then followed up to 4 weeks for any sign or evidence of infection such as pus discharge. results: there was no significant association (p=0.664) between the incidence of post-operative infections and pre-operative administration of antibiotics. significant association p.value (0.032) between prevalence of postoperative infection and type of surgery. conclusion: perioperative prophylactic antibiotics have been proven to lower infection rates postoperatively. open reduction presented with significant complication (infection) than closed reduction modality of treatment. key words: compound facial fractures, prophylactic antibiotics. (received 20/12/2018; accepted 21/1/2019) introduction maxillofacial injuries are a serious public health and economic problem as their treatment time spent in hospital, and off work is expensive. they are also often associated with severe morbidity, disfigurement, and psychological problems. their epidemiology may vary widely from country to country (and even within the same country) and it is dependent on several factors, including culture, socioeconomic background, and population density (1). in an era of increased antibiotic resistance, as well as greater focus on evidence-based medicine and reducing health care costs, it is important to review the evidence for prophylaxis antibiotics in facial fractures (2). the use of antibiotics in facial fractures is not without its problems. (1) board student, oral and maxillofacial surgery unit, al-yarmook teaching hospital. (2)professor, head of iraqi scientific council of maxillofacial surgery. it can be associated with allergic or toxic reactions, other adverse effects, drug interactions; and it contributes to increasing bacterial resistance. in addition, some authors think that a prolonged course of antibiotic might increase the risk of complications from superinfection (3). the duration of therapy is important in order to gain maximum treatment benefit while minimizing the development of resistance and other adverse effects. as far as possible, antibiotics should be administered for the shortest duration possible and many studies showed that short-duration therapy is as effective as longer durations and helps to minimize inadvertent sequelae of antibiotics (4). a good prophylaxis happens when there are effective serum concentrations of the drug since the opening of the skin or mucosa until its closure. due to this fact, the antibiotic should be used in the hour previous to the incision (5). the antibiotic prescribing practice of surgeons managing facial fractures remains elusive. this field is relatively unexplored for nonoperative facial fractures (6). the purpose of this study was to evaluate the role and significance of preoperative, perioperative and postoperative antibiotic j bagh college dentistry vol. 31(3), september 2019 prophylactic antibiotics 18 prophylaxis for patients undergoing surgical treatment of compound facial fractures to prevent postoperative infections utilizing ceftriaxone as the drug of choice. material and methods a total of 70 iraqi patients aged 4-65 years; 50 males and 20 females attended to the oral and maxillofacial surgery unit at al-yarmouk teaching hospital, baghdad from january 2017 to july 2018 and who met the eligibility criteria were enrolled in this study to evaluate the infection rate of patients who sustained with compound facial fractures. the patients were allocated into two groups, group a in which the patients administrated pre, peri and postoperative antibiotics. postoperatively the antibiotics were utilized in two different regimen timing. in group b antibiotics were administrated peri and post-operatively. the distribution of patients in the two groups is illustrated in table (1). table (1): study sample 70 patients group (a)-50 patients group (b) -20 patients received pre, peri and postoperative antibiotics: • subgroup (1): 25 patients, the antibiotics were administrated for 3 days postoperatively. • subgroup (2): 25 patients, the antibiotics were administrated for 7 days postoperatively. received peri and postoperative antibiotics for 7 days. eligibility criteria 1. patients with facial compound fractures to be treated by closed or open reduction. 2. patients with good compliance to cooperate for follow up. 3. civilian injuries. exclusion criteria: 1. patients with comminuted fractures. 2. patients with grossly contaminated fractures. 3. patients who are already on antibiotics. 4. polytrauma patients. 5. patients who need intensive care. 6. acutely infected wounds and fractures. 7. gunshot wounds. 8. pathological fracture (as a result of cysts, or tumor metastases, for example). 9. fracture of the skull base. 10. history of malignancy or active radiation to the head and neck. 11. compromised host defense (immunosuppression, malabsorption, etc…). surgical procedures the procedures were undertaken under general anesthesia or local anesthesia, there were two lines of treatment for facial bone fractures. a. closed reduction: was achieved by erich arch bars or eyelet wires as a method of fixation, immediately was secured with the use of stainless tie wire between the upper and lower jaws b. open reduction: through an extraoral or intraoral approachs according to fracture site and displacement, the fracture was reduced manually under direct vision. fixation was done by miniplates or wiring. antibiotic regimen patients were divided or categorized into 2 groups based on the duration of antibiotic prophylaxis. group (a): in group (a) 25 patients received antibiotics preoperatively at time of admission, perioperatively at day of surgery and post operatively. the patients in this group were subdivided into two sub groups, based on the duration of receiving postoperative antibiotics: subgroup 1: patients received only ceftriaxone (1g) intravenously (iv) 12 hourly and metronidazole (500 mg) iv 8 hourly for 3 days postoperatively. subgroup 2: patients received ceftriaxone (1g) iv and metronidazole (500 mg) iv 8 hourly for 7 days postoperatively. group (b): the patients in this group received perioperative and postoperative antibiotics or 7 days without preoperative dose. perioperative prophylaxis of ceftriaxone iv was administered 1-2 hour prior to surgery in both groups of patients. follow up all patients were instructed for oral hygiene measure using 0.2 % chlorhexidine mouth wash at least twice daily for 10 days. all patients are evaluated for 4 weeks postoperatively for infection according to the criteria for infections of the surgical site published by the centers for disease control and prevention (cdc).these include: j bagh college dentistry vol. 31(3), september 2019 prophylactic antibiotics 19 1. purulent discharge from the site of fracture. 2. wound dehiscence. 3. abscess formation. 4. presence of signs and symptoms of infection such as localized pain, tenderness or fever (>38◦c) statistical analysis the data were analyzed using statistical package for social sciences (spss) version 25. the data presented as mean, standard deviation and ranges. categorical data presented by frequencies and percentages. pearson’s chi– square test was used to assess statistical association between prevalence of postoperative infection and certain variables. a level of p value less than 0.05 was considered significant. results there was no significant association (p ≥ 0.05) between prevalence of infection and both of age and gender as in table (2). in this study postoperative infection developed in 7 patients (10%) as illustrated in figure 1. the most common cause of fractures was rta 47.1%, while the least etiological factor was crush injury in this study, the most common site of infections was the mandible (table 3). table (2): association between incidence of postoperative infection and demographic data table (3): association between incidence of postoperative infection and certain clinical information clinical information postoperative infection total (%) n= 70 pvalue yes (%) n= 7 no (%) n= 63 cause of fracture rta 5 (15.2) 28 (84.8) 33 (47.1) 0.394 ffh 0 (0) 18 (100.0) 18 (25.7) assault 1 (10.0) 9 (90.0) 10 (14.3) crush injury 1 (11.1) 8 (88.9) 9 (12.9) site of fracture mandible 4 (8.3) 44 (91.7) 48 (68.6) 0.67 midface 3 (13.6) 19 (86.4) 22 (31.4) demographic data postoperative infection total (%) n= 70 pvalue yes (%) n= 7 no (%) n= 63 age (years) < 20 1 (4.3) 22 (95.7) 23 (32.9) 0.247 20 – 39 6 (17.1) 29 (82.9) 35 (50.0) 40 – 59 0 (0) 11 (100.0) 11 (15.7) ≥ 60 0 (0) 1 (100.0) 1 (1.4) gender male 7 (12.5) 49 (87.5) 56 (80.0) 0.331 female 0 (0) 14 (100.0) 14 (20.0) j bagh college dentistry vol. 31(3), september 2019 prophylactic antibiotics 20 fig.(1): distribution of study patients by postoperative infection. in group a the infection rate was 12% (6 out of 50) of patients whereas in group b the infection rate was 5% (one case out of 20) of patients. the difference was statistically non-significant (p=0.664%) as in table (4). also there was no significant difference between the two subgroups; the infection rate in subgroup 1 was 4% (1 of 25 patients) while in subgroup 2 the infection rate was 20% (5 of 25) as in table (5). the incidence of post-operative infections with patients treated by open reduction surgery was 23.5% (4 of 17) compared with 5.7% (3 out of 53) patients treated by closed reduction with significant difference (p=0.032) as shown in table(6). table (4): the association between antibiotic administration regimen (group a & b) and postoperative incidence of infection. table (5): association between antibiotic administration regimen (three or seven days postoperatively) and incidence of postoperative infection. table (6): association between the incidence of post-operative infection in closed and open reduction. 7(10%) 63(90%) antibiotic administration regimen postoperative infection total n= 50 (%) pvalue yes n= 6 (%) no n=44 (%) subgroup 1 (3 days) 1 (4.0) 24 (96.0) 25 (50.0) 0.189 subgroup 2 (7 days) 5 (20.0) 20 (80.0) 25 (50.0) type of surgery postoperative infection total n=70 (%) pvalue yes n=7 (%) no n=63 (%) closed reduction 3 (5.7) 50 (94.3) 53 (75.7) 0.032 open reduction 4 (23.5) 13 (76.5) 17 (24.3) antibiotic administration regimen postoperative infection total n= 70(%) pvalue yes n= 7 (%) no n=63 (%) group a 6 (12.0) 44 (88.0) 50 (71.4) 0.664 group b 1 (5.0) 19 (95.0) 20 (28.6) infection no infection j bagh college dentistry vol. 31(3), september 2019 prophylactic antibiotics 21 discussion in this study which investigated the incidence of infection following ceftriaxone administration for patients who have sustained compound facial fractures, males were subjected to fractures more than female with a ratio of 4:1 and the difference owing to occupations and outdoor activities which is in line with lauder et al (7). most of the patients (50%) were aged between 20-39 years (3rdand 4th decades) and this was similar to the result reported by mamthashri and reddy where the majority of their patients (75%) were between 21 – 40 years this maybe also attributed to the fact that people in these age groups are more prone to trauma due to more outdoor activities (8). in the present study, the most common cause of fractures was rta 47.1%, while assault occupied only. the least etiological factor was crush injury, this is in agreement boffano et al who reported that in low-income and middleincome countries, road traffic accidents and interpersonal violence are the main cause of maxillofacial fractures, they reported that the most common cause of facial bones fractures in turkey was rta 144 out of 216 (67.1%) and saudi arabia was also rta 122 out of 200 (61%) (9). the highest number of fractures was seen in the parasymphyseal regions (34.3%), which is close to the study performed by boffano et al (30%); and mamthashri and reddy (35%) (1,8). adalarasan et al reported that symphyseal region was a common site of fracture (45%) (10). abubaker et al reported that most of the infections occurred in the mandible (11). also schaller et al stated that fractures involving the tooth-bearing regions of jaw have greater chance for infections when compared with other locations for example angle fracture(3). in this study, the most common site of infections was the mandible; parasymphyseal region was 4 of 7 infected patients which was also not significant in both groups. in this study there is no association between the incidence of postoperative infection & antibiotics administration regimen in group a & b (p=0.664). the study was in the line with lauder et al who found that 8% of patients that received periand postoperative antibiotics had postoperative infections compared to 9% of patients who received preperiand postoperative antibiotics with nonsignificant difference between both options(7). in this study there was no significant difference between the two subgroups1 and 2. in subgroup 1 the infection rate was 4% (1 of 25 patients) while in subgroup 2 the infection rate was 20% (5 of 25 patients). this was similar to zix et al who reported that there was no significant difference in rate of infection for more than 24 hours with post-operative antibiotic prophylaxis for overall patients the rate of infection was 5% (3 of 60) (12). this study showed the men age of the patients were males from 20 to 39 years (50%) with a mean age 20 years in relation to the infection rate which was 17.1%, this might be due to the fact that most age decades of the study was young males. adalarasan et al stated that the highest percentage of infections was 11% were associated with 20-39 years old patient (10). this was similar to this study 17.1%. in the study the association between postoperative infection and type of surgery (closed or open reduction) was high incidence of post-operative infections with patients treating by open reduction surgery 23.5% (4 of 17) compared with 5.7% (3 out of 53 patients) treated by closed reduction. the higher incidence of postoperative complications with open reduction may due to the fracture site communication to the oral cavity. extensive periosteal stripping may decrease the resistance to infection, decreases vascularity through periosteal elevation and increases the possibility of infections. shridharani et al stated that in mandibular fracture management one must consider is whether to employ surgical therapy. open reduction and internal fixation (orif) procedures have been shown to have up to a fourfold increase in infection rates compared to closed reduction(13). the result of this study was in line with schaller et al who claimed that antibiotic prophylaxis is part of the standard treatment of mandibular fractures treated by open reduction and internal fixation(3). conclusions 1. young males were more affected than female in compound facial fracture. 2. rta was the most common etiology of facial fractures. 3. dentated regions of the upper and lower jaws were subjected more too postoperative infection. 4. open reduction presented with significant complication (infection) than closed reduction modality of treatment. 5. the use of more than 3 days of postoperative prophylactic antibiotics did not have a j bagh college dentistry vol. 31(3), september 2019 prophylactic antibiotics 22 statistically significant effect on postoperative infection rates in the surgical management of facial fractures. 6. perioperative prophylactic antibiotics have been proven to lower infection rates postoperatively. references 1. boffano p, roccia f, zavattero e, dediol e, ugleši v, kova i , et al. european maxillofacial trauma (eurmat) project: a multicentre and prospective study. j craniomaxillofac surg. 2015; 43(1):62–70. 2. morris, md. lisa m; robert m. kellman, md: prophylactic antibiotics in facial fractures. laryngoscope 124: june 2014. 3. schaller b, poh luon soong,, jürgen zix, tateyuki iizuka, olivier lieger, the role of postoperative prophylactic antibiotics in the treatment of facial fractures: a randomized, double-blind, placebo-controlled pilot clinical study. part 2: mandibular fractures in 59 patients. br j oral maxillofac surg, 2013. 4. miles ba, potter jk, ellis e 3rd. the efficacy of postoperative antibiotic regimens in the open treatment of mandibular fractures: a prospective randomized trial j oral maxillofac surg. 2006; 64(4): 576–82. 5. escobar s. ji, del amo-fernández de velasco a. antibiotic prophylaxis in oral and maxillofacial surgery. med oral patol oral cir bucal, 2006; 11: e292-6. 6. mundinger gs, borsuk de, okhah z, et al. antibiotics and facial fractures: evidence-based recommendations compared with experience based practice. craniomaxillofac trauma reconstruction 2015; 8:64–78. 7. lauder a, jalisi s, spiegel j, stram j, devaiah a. antibiotic prophylaxis in the management of complex midface and frontal sinus trauma, laryngoscope 2010; 120:1940–1945, 2010. 8. mamthashri v, bokka praveen reddy. comparison of preoperative and perioperative antibiotic prophylaxis regimen in compound facial fractures. j contempo dent pract. 2018; 19(2):1-7. 9. boffano p. sofie c.kommers, k.hakki karagozoglu, tymour forouzanfar/ aetiology of maxillofacial fractures: a review of published studies during the last 30 years. br j oral maxillofac surg 52 (2014) 901–906. 10. adalarasan. s, mohan a, and pasupathy s. prophylactic antibiotics in maxillofacialfractures: a requisite? j craniofac surg 2010;21: 10091011). 11. abubaker, a omar , and michael k. rollert. postoperative antibiotic prophylaxis in mandibular fractures: j oral maxillofac surg. 2001; 59:1415-1419. 12. zix j, benoit schaller, tateyuki iizuka, olivier lieger. the role of postoperative prophylactic antibiotics in the treatment of facial fractures: a randomised, double-blind , placebo-controlled pilot clinical study. part 1: orbital fractures in 62 patients. br j oral maxillofac surg 51.2013; 332–336. 13. shridharani. sachin m, , jens berli, , paul n. manson, , anthony p. tufaro, , , and eduardo d. rodriguez, the role of postoperative antibiotics in mandible fractures: a systematic review of the literature. ann plast surg. 2015 22;75(3):353357. j bagh college dentistry vol. 31(3), september 2019 prophylactic antibiotics 23 الخالصة ال يزال دور المضادات الحيوية الوقائية مثيًرا للجدل. تختلف كسور الوجه في موقعها وشدتها ويمكن أن تمتد إلى مدى تصنيفات الخلفية: الجرح بما في ذلك النظيفة ، والملوثة النظيفة والملوثة والقذرة / المصابة. من الواضح أن كسور الوجه النشطة تعتبر ملوثة نظيفة ويجب ضادات الحيوية العالجية ؛ ومع ذلك ، هناك تباين واسع في استخدام ونوع وتوقيت ومدة المضادات الحيوية االتقائية تدار في معالجتها بالم ت الممارسة اليوم. هناك تأثير سلبي لزيادة مقاومة المضادات الحيوية ، وكذلك التكاليف ، من المهم مراجعة األدلة الحالية لدور المضادا .ة في كسور الوجه المركبةالحيوية الوقائي الهدف من هذه الدراسة هو تقييم دور وأهمية العالج الوقائي بالمضادات الحيوية قبل الجراحة قبل وبعد العملية الجراحية للمرضى الهدف: .عندما يكون هناك بالفعل تركيز معدي ، مثل كسر الوجه المركب من اإلناث الذين ٢٠من الذكور و ٥٠سنة ، و ٦٥-٤عراقيا تتراوح أعمارهم بين مريضا ٧٠تم تسجيل ما مجموعه :العمل طرقالمواد و استوفوا معايير األهلية في هذه الدراسة لتقييم معدل اإلصابة من المرضى الذين تعرضوا لكسور الوجه المركبة المعالجة من قبل جراحة مريضا تدار من قبل والمضادات الحيوية وبعد ٥٠، المجموعة )أ( شملت تم تقسيم الحاالت إلى مجموعتين . التخفيض المفتوحة أو المغلقة (العملية الجراحية. بعد العمل الجراحي ، استخدمت المضادات الحيوية في نظامين مختلفين للتوقيت. في المضادات الحيوية من المجموعة .أسابيع للحصول على أي عالمة أو دليل على اإلصابة مثل إفراز القيح ٤مريضا. ثم تمت متابعتهم لمدة ٢٠وبعد الجراحة ل تدار حول ب( بين حدوث العدوى بعد العمليات الجراحية وإعطاء المضادات الحيوية قبل العملية =p) ٠٫٦٦٤ (يلم يكن هناك ارتباط معنو النتائج: بعد الجراحة ونوع الجراحة.بين انتشار عدوى ما =p)٠٫٠۳٢ ) هالقيمه المعنوي الجراحية. ارتباط كبير ثبت أن المضادات الحيوية الوقائية المحيطة بالجراحة تقلل من معدالت اإلصابة بعد العمل الجراحي. خفض مفتوح مع مضاعفات االستنتاج: .)العدوى( كبيرة من طريقة التخفيض المغلقة للعالج j bagh college dentistry vol. 29(4), december 2017 measurement of serum oral and maxillofacial surgery and periodontics 76 measurement of serum superoxide dismutase levels in women with polycystic ovarian syndrome and chronic periodontitis ayser najah, b.d.s., m.sc. (1) suzan ali salman, b.d.s., m.sc. (2) hadeel mazin akram, b.d.s., m.sc. (3) maha abdulaziz ahmed, b.d.s., m.sc. (4) lubaba a. abdul ameer, b.d.s., m.sc. (5) azza wala aldeen khairi, b.d.s.(6) abstract background: polycystic ovarian syndrome (pcos) is one of the most important reproductive and endocrine disorders in women at reproductive age. it's associated with metabolic disorder, obesity, insulin resistance and oxidative stress chronic periodontitis and pcos both of them associated with low chronic grade of inflammation. the prevalence of periodontal disease seems to be higher in women with pcos. superoxide dismutase enzyme (sod) is an important circulating marker and protecting enzyme helping the body tissues to get rid of reactive oxygen species (ros) that damage the tissue. aim of the study: the aim of this study was to measure and compare the levels of (sod) among group of chronic periodontitis patients with pcos, group of chronic periodontitis without pcos and a third group who were systemically and periodontally healthy. material and method: this study consist of (60) women at reproductive age ranged between (25-40) years old. they divided into three groups group i consist of 20 women systemically healthy and with healthy periodontium, group ii consist of 20 women with chronic periodontitis and systemically healthy and group iii consist of 20 women with chronic periodontitis and (pcos). we evaluated the periodontal health of the groups through measuring these important indices: plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment loss. sod antioxidant marker was measured colormeterically for the three groups. results: this study showed higher means of periodontal parameters (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment loss (1.275±0.246, 1.295±0.239, 0.24±0.16, 6.47±0.345, 4.125±0.328 respectively). highly significant differences were found using t-test in inter group comparison. (p≤0.001) regarding pocket depth and clinical attachment loss .higher mean of (sod) level was found for g3 (137.72±29.769) u/ml . f-test was used for intragroup comparison and highly significant difference was found (p≤0.001). positive but weak correlation where found among (sod) level, bleeding on probing in group i and group ii , also among (sod) level, probing pocket depth and clinical attachment loss. conclusion: (pcos) associated with oxidative stress and more prone to periodontal diseases with high level of antioxidant agent like (sod) level to compensate the high level of (ros) key words: superoxide dismutase enzyme, chronic periodontitis, polycystic ovarian syndrome. (j bagh coll dentistry 2017; 29(4): 76-81) introduction chronic periodontitis is one of the most important chronic inflammatory disease resulting from accumulation of dental plaque on the tooth surface that cause destruction in periodontal attachment and adjacent alveolar bone, its recently defined as “an infectious disease resulting in inflammation with in supporting tissues of the teeth, progressive attachment loss and bone loss”(1) (1) assistant professor, department of periodontics, college of dentistry, university of baghdad. (2) assistant professor, department of periodontics, college of dentistry, university of baghdad. (3) lecturer, department of periodontics, college of dentistry, university of baghdad. (4) professor, department of periodontics, college of dentistry, university of baghdad. (5) lecturer, department of periodontics, college of dentistry, university of baghdad. (6) dentist, department of periodontics, college of dentistry, university of baghdad. chronic periodontitis can occur when there is imbalance between host response and microbial biofilm and their product. specifically when loss of balance between antioxidant defense systems that protect and repair vital tissue cells (ros).(2) chronic exposure to ros can initiate pathologic reactions like periodontal disease. the body has evolved certain defense and repair systems inherently to prevent the accumulation of oxidatively damaged molecules that are toxic by producing the antioxidant agents. antioxidants are defined as those substances that protect body tissues and balance the damaging oxidative effect. (sod) is one of the antioxidant enzymes that protect the cell against the deleterious effects of (ros). (sod) convert the superoxide anion to hydrogen peroxide and it's the first line of defense in antioxidant reactions against (ros).(3-5) studies have found that gingival sod activity is significantly higher in chronic periodontitis, j bagh college dentistry vol. 29(4), december 2017 measurement of serum oral and maxillofacial surgery and periodontics 77 which suggested that sod activity increases with the progression of inflammation.(6) (pcos) it is one of the most common hormonal disorder affecting women at reproductive age (1844).years old (7). according to national institute of health [nih] criteria the prevalence of (pcos) ranging from 6.5% 8%.(8) it considered as metabolic syndrome with cardiovascular, insulindependent diabetes (ir), dyslipidemia and endothelial dysfunction and visceral obesity(9) risk factors. because both periodontitis and metabolic syndrome are associated with systemic inflammation and ir, these two disorders may be linked through a common pathophysiologic pathway(10) (pcos) is like chronic periodontitis associated with chronic inflammation.(11) importantly, the effect of female steroid hormones on the composition of oral microbiota has been reported in puberty, menstruation, pregnancy and with oral contraceptive usage(12) taking into consideration that periodontal diseases are chronic infections that cause a low-grade chronic systemic inflammation(13)it is important to consider an association with hormonal disorders, such as (pcos). kuçu et al. (2009) demonstrated that (sod) levels were significantly higher in a (pcos) group compared with a control group (8.0±0.7 vs 7.28±0.8, p=0.001). the aim of this study was to measure and compare the levels of (sod) among group of chronic periodontitis patients with (pcos), group of chronic periodontitis without (pcos) and a third group who were systemically and periodontally healthy. material and methods study design: sixty females were participated in this study with an age range between (25-40) years old. they were patients who attended the teaching hospital of college of dentistry, university of baghdad and baghdad hospital/ infertility clinic. participants enrolled in the study should be healthy with no history of any systemic diseases, non-smoker non pregnant, not take antibiotic or other medication in the last three months. patients undergo periodontal treatment in the last three months should be excluded. in the study the participants were divided into three groups  group 1 (g1) consist of (20) females with healthy periodontium.  group 2 (g2) consist of (20) females with chronic periodontitis  group 3 (g3) consist of (20) females with chronic periodontitis and pcos. participants in g1and g2 should be with regular menstrual cycles and with no clinical or biochemical features of hyperandrogenism and without pcos improved by ultrasound. g2 & g3 should have at least four surfaces with probing pocket depth (≥ 4mm) and clinical attachment loss of (1-2 mm) or more(15). participants that have pcos were diagnosed by the gynecologist according to rotterdam criteria (16). periodontal examination: measurement of clinical periodontal parameters were performed by using michigan o periodontal probe at the four sides (buccal or labial, lingual or palatal, mesial and distal) of all teeth excluding the third molar tooth; participants should have at least (20) teeth. the data collected included: plaque index (pli) (17), gingival index (gi) (18), bleeding on probing (bop)(19), probing pocket depth (ppd)(20), and clinical attachment level (cal)(20). collection of blood samples: blood sample of 3ml of was taken from each participant of the three groups. the blood was transferred into gel tubes and allowed for 30 minutes at room temperature to help clot formation and separation of serum subsequently, then centrifuged at 1000 rpm for (15 minutes) to separate the serum and kept frozen at (-20 °c).(21) the level of (sod) was measured colormetrically by spectrophotometer. (sod) assay kit reagents: carbonate buffer (50 mm, ph 8.00): ethylenediaminetetraacetic acid sodium salt buffer (10 mm, ph=10.2): epinephrine indicator: procedure: sample µ l carbonate buffer (50 mm, ph 8.00) µ l ethylenediaminet etraacetic acid sodium salt buffer (10mm, ph=10.2) µ l epinephrine µ l 100 1800 1000 100 read the samples at a wave length 480 nm immediately (a1) and after 5 minutes (a2). calculation of (sod) enzyme activity: one unit of sod was defined as the amount of enzyme that inhibit the oxidation 50%. blank sample was used in order to exclude different spontaneous degree of oxidation. the absorbance of blank sample was subtracted from j bagh college dentistry vol. 29(4), december 2017 measurement of serum oral and maxillofacial surgery and periodontics 78 the absorbance of the sample to calculate the real absorbance of each sample. the activity (units/ ml) is given by the following equation. one unit is the amount of enzyme that catalysis the reaction of 1 µmol of substrate per minute. inhibition % = (a1-a2)/a1 superoxide dismutase activity (u/ml) = (i%/2/t) xd superoxide dismutase activity (micromole/min/ml) = (i%/2/5) x300 i%= inhibition, t= time= (5), d= dilution factor= 300. statistical analysis was evaluated by employing ttest, analysis of variance (anova) test, and pearson's coefficient of correlation (r). significant (s) = 0.05≥ p > 0.01 highly significant (hs) = p ≤ 0.01 non-significant (ns) = p > 0.05 this study implicating human subjects is in accordance with the helsinky declaration of 1975 as revised in 2000 and that it has been approved by the relevant institutional ethical committee. results table (1) revealed descriptive analysis, mean and standard deviation for the periodontal parameters of (pli, gi, bop score (1), ppd, cal) for three study groups. the highest mean of pli and gi were belong to g3, they were (1.275±0.246 & 1.295±0.239) respectively. for bop score (1), ppd and cal, highest mean in g3 they were (0.24±0.16, 6.47 ±0.345, 4.125 ±0.328) respectively. table (2) revealed the intergroup comparison regarding the periodontal parameters t test was used, highly significant differences were found for ppd and cal (p value > 0.001) table (3) revealed mean and standard deviation of superoxide dismutase (u/ml ) for gi, g2, g3. for g1the mean value was (21.12±2.48) u/ml. it was (56.51±13.574) u/ml for g2 and it was 137.72±29.769 u/ml for g3. ftest was used to show the intragroup comparison, highly significant differences were found (p<0.001). table (4) was shown inter groups comparisons regarding sod level and highly significant differences (p>0.001) were found between each pairs of groups. table (4) revealed the correlation between the periodontal parameters (pli, gi, bop score (1), ppd, cal) and (sod) for g2 and g3. for g2 positive but non-significant correlation was found for sod level with the gi and bop. for g3 positive but non-significant correlation was found for sod level with pli, ppd and cal. table 1: describe mean and standard deviation for the periodontal parameters of the three groups groups pli gi bop score 1 ppd cal mean + sd mean + sd mean + sd mean + sd mean + sd gi 0.44 0.06 0.31 0.06 ----------------------------------- g2 1.205 0.234 1.24 0.084 0.215 0.15 5.025 0.535 3.26 0.298 g3 1.275 0.246 1.295 0.239 0.24 0.16 6.47 0.345 4.125 0.328 table 2: intergroup comparison for the periodontal parameters with significant differences using ttest t-test p-value sig pli -0.92 0.36 ns gi -0.97 0.34 ns bop 0.47 0.6 ns ppd -10.14 <0.001 hs cal -8.73 <0.001 hs table 3: describe mean, standard deviation of sod levels (u/ml) of the three groups and intragroup comparison with significant differences using the ftest groups sod (u/ml) f test p-value sig mean + sd gi 21.12 2.48 g2 56.519 13.574 199.1633 <0.001 hs g3 137.72 29.769 j bagh college dentistry vol. 29(4), december 2017 measurement of serum oral and maxillofacial surgery and periodontics 79 table 4: intergroup comparison of the sod level (u/ml) with significant differences using ttest groups t-test p-value sig g1&g2 -11.47 <0.001 hs g2&g3 11.09 <0.001 hs g1&g3 17.4 <0.001 hs table 5: pearson's coefficient of correlation (r) between sod levels (u/ml) and periodontal parameters for g2 and g3 with significant differences r p-value sig g2 sod & pl.i -0.23 0.33 ns sod & gi 0.29 0.21 ns sod & bop 0.17 0.47 ns sod & ppd -0.12 0.61 ns sod & cal -0.41 0.07 ns g3 sod & pl.i 0.36 0.12 ns sod & gi -0.32 0.17 ns sod & bop -0.03 0.9 ns sod & ppd 0.22 0.35 ns sod & cal 0.21 0.34 ns discussion the current study was compared important periodontal parameters, antioxidant marker (sod) among women with healthy, chronic periodontitis and chronic periodontitis with pcos till now few studies related to these subjects are present. our results revealed higher periodontal parameters in g3, these finding are compatible with these studies 22,23,24,25 that showed higher periodontal indices among women with pcos. the effect of steroidal hormones imbalance during puberty, pregnancy and menopause on the periodontal flora and health had been reported (26), women with pcos have hormonal imbalance, hyperandrogenism with elevated total testosterone. hyperandrogesim status in those women resulting in infertility, disturbance in menstrual cycle and increased risk to periodontal diseases. testosterone will convert to estrogen, high level of estrogen and testosterone are exist.(27) increased in estrogen and progesterone level associated with increased in gingival inflammation, capillary changes and excessive proliferation of vascular endothelial cells.(28) increased susceptibility of pcos women to periodontal diseases due to influence of altered circulating steroidal hormones in the periodontal tissues. these changes impact gingival tissues through changes in oral flora and proinflamatory cytokines affecting the bone and enhanced oxidative stress in periodontal tissues of patients with pcos. pcos appeared to have an enhancing effect on the levels of p.gingivalis and f. nucleatum and their association with gingival inflammation, hinting towards a microbial specificity(6) in this study we exclude smoker patients and those under antibiotic treatment or having systemic diseases that had effect on periodontal health to minimize the effect of these risk factors. in agreement with other previous studies (22) bop is highest in patients with pcos due to the effect of hyperandrogenism on vascular flow rate but with none significant difference in comparison between the groups. also the increased in cal and ppd in g3 might attributed to increased susceptibility to inflammatory process and gingival inflammation that progress to more sever periodontal destruction and subsequent increased in gingival sulcus, attachment loss and bone loss. inflammation that associated with periodontitis involving increased in production of oxygen free radical manly from inflammatory polymorphnuclear cells (pmns) these cells are important in first line of defense mechanism. these free radicals recently known as (ros), although the (ros) have short half-life they cause damage to the host cells through production free radical chain reactions. pcos associated with oxidative stress and metabolic disorder and insulin resistance oxidative stress can define as imbalance between production of antioxidant markers (ao) and oxidative agents (ros) protection against these species provided through production (ao) from pmns and other cells. these agents when present they will protect the tissues against the free radicals and inhibit or delay oxidation of the substrate.(29,30,31). superoxide dismutase enzyme is one important ao that protect the tissues against the ros.(32) in this study the concentration of (sod) was higher j bagh college dentistry vol. 29(4), december 2017 measurement of serum oral and maxillofacial surgery and periodontics 80 in the g3 those women suffering from chronic inflammation in the periodontium and pcos 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(1) abstract background: oral health represents an important base for human well-being; the heath of the body begins from oral cavity. great deal has been applied to increase knowledge in the field of oral health in order to develop appropriate preventive program. this study was conducted in order to estimate the percentage and severity of dental caries and gingivitis among children attending preventive department in collage of dentistry, university of baghdad and to determine dental treatment need for those patients, further more to study the relation of these variables with dental knowledge. materials and methods: the study group consists of 163 children with an age ranged from 6 to 14 years, who attended the preventive clinic for the first time to be involved in preventive program. plaque index and gingival index were applied for examination of dental plaque and gingivitis, dental caries and treatment need was recorded according to criteria described by who. dental knowledge of each child was evaluated by ten questions prepared for this reason. results: the results showed that caries-experience among permanent teeth represented by ds and dmfs were (3.22 ± 0.31 and 4.09 ± 0.35) respectively, while caries-experience among deciduouse teeth represented by ds and dmfs were (6.79 ± 0.61 and 9.03 ± 0.81) respectively. analysis of variance (one way anova test-) showed that caries experience among permanent teeth increased with age (p < 0.001), while caries-experience among deciduous teeth decreased with age (p 0.001). the majority of studied sample were in need for one surface filling (93%) followed by two or more surface filling (66%). high percentage of children involved in this study had mild accumulation of plaque and mild gingivitis (69.93% and 83.43%) respectively. evaluation of dental knowledge among those children showed that 67% of them had good dental knowledge (scores 5), but weak correlations were recorded between good dental knowledge and caries experience for deciduous teeth(r=0.12, p > 0.05) and for permanent teeth (r=0.22, p<0.05).the same correlation was recorded between dental plaque and dental knowledge (r=0.05, p> 0.05). conclusion: those children need further motivation and instructions to improve their dental knowledge and to improve their attitude to change their behavior towards further improvement of oral hygiene and oral health. key words: oral health status, treatment need, dental knowledge. (j bagh coll dentistry 2015; 27(4):138-142). introduction oral health means more than healthy teeth, it is a state of being free from chronic mouth and facial pain, oral and throat cancer, oral sores, birth defects such as cleft lip and palate, periodontal (gum) disease, tooth decay and tooth loss, and other diseases and disorders that affect the oral cavity (1). in spite of that, dental caries still represent the most common oral disease followed by periodontal diseases, so evaluation of these two oral diseases may give an indication about oral health condition (2,3). research in oral health condition among different samples of population may produce a wide base of information that may play an important role in development of appropriate preventive programs and in organization of dental resources (4-6). on the other hand, dental knowledge is one of the important factors that affect oral health. children may accept dental knowledge from their homes or their schools, this knowledge may promote them to maintain good oral health, or may remain as an information only(7,8). (1)assistant lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. the present study was conducted in order to estimate the prevalence and severity of dental caries and gingivitis among children attending preventive department and to determine dental treatment need for those patients, further more to study the relation of these variables with dental knowledge. data gained may initiate or increase the knowledge concerning oral health status of those children and may aid for planning or improving of dental health programs among the study group. materials and methods the study group consisted of children attending the preventive clinic, college of dentistry, university of baghdad for the first time, those children were involved in preventive program that include thorough oral hygiene and dietary habits instructions in addition to full mouth dental treatment. collection of data started from 20/2/2014 to 20/5/2014, the total number of patients was 163 children with an ages range from 6 to 14 years. dental plaque severity was recorded according to the criteria described by silness and loe (9), j bagh college dentistry vol. 27(4), december 2015 oral health status pedodontics, orthodontics and preventive dentistry 139 diagnosis and assessment of gingival health condition was recorded according to criteria described by loe and silness (10), where ramfjored index teeth (11) were examined in both index (plaque index and gingival index). examination and assessment of dental caries was done according to criteria described by who (12) using plane dental mirror and an explorer (no.00). after assessment of dental status, the need for treatment of each tooth was recorded according to criteria of treatment need described by who (12) as following: 0: no treatment. 1: caries arresting or sealant care. 2: one surface filling. 3: two surface filling. 4: crown for any reason. 5: bridge elements. 6: pulp care. 7: extraction. 8: need for any other care. dental knowledge of each child was evaluated by ten questions that prepared for this reason. they were as following: 1. do you think that it is important to have dental brush? 2. do you think that it is important to use the brush and paste to clean the teeth? 3. is it important to brush the teeth twice or more daily? 4. what type of food may cause dental caries? 5. what type of food may increase teeth resistance against caries? 6. do you think that you have to visit the dentist for checking up? 7. do you think that good oral hygiene is important for healthy teeth? 8. may progression of dental caries cause losing of teeth? 9. could losing of teeth cause disharmony of teeth? 10. could losing of teeth affect your appearance? answers for all questions were either (yes) or (no), where (yes) was gave code (1), while (no) was gave code (0). except question 4 the answers were either sweets (code 1) or others (code 0), and question 5 the answers were either milk group (code 1) or others (code 0). so that (10) was the maximum total score. for each child's parents the objectives of the study were explained to, and they approved to participate. data were analyzed by using spss soft ware (statistical package for social sciences) by using (analysis of variance (one way anova test), student's t-test and person's correlation coefficient) results according to age the sample was divided into three age groups; (6-8) years which was the largest one in number followed by (9-11) years, then (12-14) years which was the smallest one, generally boys were slightly higher in number than girls as shown in table (1). results showed that all children involve in this study were affected by dental caries. cariesexperience among permanent teeth represented by (ds and dmfs) was higher among the last age group (12-14) than others, the difference was statistically highly significant (p<0.001), while caries-experience among deciduous teeth (ds and dmfs) was higher among the first age group (6-8) than others, the difference was statistically highly significant too (p<0.001) as illustrated in table (2). boys totally show higher values of cariesexperience including (ds, dmfs, ds and dmfs) than girls, but these values were statistically not significant. distribution of sample according to treatment need showed that the majority of studied sample were in need for one surface filling (93%) followed by two or more surface filling (66%), while needs for bridges and other care showed the minimum percentage (1.84%, 7.36%) respectively as shown in table (3). according to results of the present study the differences between means of plaque index and gingival index between age groups were statistically not significant (p > 0.05), while highly significant difference was found between boys and girls involved in this study for pi (p< 0.001) and significant difference between them for gi (p< 0.05) as shown in table (4). strong, positive and highly significant correlation was reported between pi and gi among (9-11) and (12-14) age groups. generally high percentage of children involved in this study had mild accumulation of plaque and mild gingivitis (69.93% and 83.43%) respectively. while only small percentage of them was suffering from fair oral hygiene and sever gingivitis (1.22% and 2.45%) respectively. evaluation of dental knowledge among those children showed that the three age groups had high percentage of positive answers for the majority of the questions. furthermore, 67% of them expressed good knowledge (scores 5), where 61% of (6-8) age group, 76% of (9-11) age group and 66% of (12-14) age group showed good knowledge. on the other hand weak correlations were recorded between caries experience and j bagh college dentistry vol. 27(4), december 2015 oral health status pedodontics, orthodontics and preventive dentistry 140 dental plaque on one hand and good dental knowledge on the other hand that was significant with (dmfs) only. table (1): distribution of sample by age and gender table (2): caries experience among the studied age groups (ds, dmfs, ds and dmfs) described by mean and standard of error. **highly significant p<0.000, df =2 (between age groups) table (3): distribution of sample according to treatment need table 4: distribution of sample according plaque index and gingival index described by (mean and standard error) and correlation between them. age group (years) pi gi correlations mean se mean se 6-8 0.85 0.05 1.93 0.86 0.04* 9-11 0.91 0.05 0.89 0.03 0.52** 12-14 0.93 0.54 0.73 0.06 0.56** anova-test 0.653 0.836 total total 0.88 0.03 1.33 0.42 0.55* boys 0.91 0.32 1.75 0.70 girls 0.83 0.06 0.63 0.04 t-test 1.20** 1.27* *significant , ** highly significant age group in years boys girls total no. % no. % no. % 6-8 49 30.06 32 19.63 81 49.69 9-11 22 13.49 21 12.88 43 26.38 12-14 28 17.17 11 6.74 39 23.92 total 99 60.72 64 33.16 163 100 age group (years) ds dmfs ds dmfs mean se mean se mean se mean se 6-8 1.22 0.18 1.41 0.20 10.74 0.91 13.07 1.17 9-11 3.02 0.38 4.16 0.52 5.38 0.96 9.59 1.54 12-14 7.48 0.98 9.41 0.78 0.25 0.10 0.25 0.10 anova test 49.47** 80.83** 34.11** 26.50** total boys 3.48 0.46 4.59 0.50 7.68 0.86 9.96 1.09 girls 2.78 0.38 3.26 0.43 5.39 0.81 7.56 1.09 t-test 1.07 1.83 1.82 1.45 total 3.22 0.31 4.09 0.35 6.79 0.61 9.03 0.81 treatment need children teeth no. % mean sd min. max. caries arresting or sealant 91 55.82 2.08 2.70 0 10 one surface filling 153 93.86 3.20 2.07 0 11 two surface filling 126 66.30 2.06 1.78 0 7 crown for any reason 27 16.56 0.30 0.70 0 3 bridge elements 3 1.84 0.02 0.13 0 1 pulp care 27 16.56 0.29 0.70 0 3 extraction 19 11.65 0.16 0.49 0 3 need for other care. 12 7.36 0.09 0.33 0 2 j bagh college dentistry vol. 27(4), december 2015 oral health status pedodontics, orthodontics and preventive dentistry 141 table (5): distribution of age groups according to dental knowledge questions (positive answers) in relation to prevalence of caries (dmfs and dmfs) and plaque index (pi) discussion caries-experience in primary teeth (dmfs) was decreased as age increased; difference was statistically highly significant (p< 0.001). this could be due to natural exfoliation of primary teeth by advancing in age. at the same time, caries experience in permanent teeth (dmfs) was increased with advancing in age; this could be due to eruption of permanent teeth and development of contact area. it was well established that caries severity increase with age due to accumulative and irreversible nature of dental caries (13). although it was statistically not significant; boys were higher than girls in all caries experience values (ds, dmfs, ds, dmfs). girls take care of their teeth health more than boys for esthetic reasons (14, 15), this could explain these results. evaluation of treatment need among those children revealed that a high percentage of those children was in need for one surface filling which was mostly occlusal surface filling, followed by two surface filling and then sealant treatment. presence of spacing between primary teeth make occlusal surface more susceptible to be affected by caries than other surfaces (14, 15). permanent teeth were relatively newly erupted, especially posterior teeth, so contact areas were newly affected by oral environment and the accumulative effect of caries process. according to all of the above, occlusal surfaces were also the most affected surfaces than others in permanent teeth among those children. all of these information's could explain why one surface filling recorded higher percentage in treatment need than others. results showed that pi values were increased with advancing in age, while gi values were decreased by advancing in age; however these differences were statistically not significant. it had been well established that dental plaque is the prime cause of gingival inflammation(16,17). results of the present study were agreed with that, where statistically strong highly significant correlation were recorded between pi and gi values within age groups, and significant strong correlation recorded between these two variable among total sample. girls showed lower values for pi and gi than boys, the difference was highly significant for pi and significant for gi. girls seem to be more interested in oral hygiene than boys. analysis of dental knowledge among those children reveled that high percentage of total sample recorded positive answers for the prepared questions (scores 5), further more high percentage of positive answers were recorded for relatively all of the prepared questions. these results reveled that the majority of those children had good knowledge (scores 5). careisexperience for both primary and permanent teeth (dmfs and dmfs) shows weak correlations with most of the questions and with mean of good dental knowledge. this may be due to multifactorial nature of carious process that depended on interaction of number of factors that should occur simultaneously (5). weak and statistically not significant correlations were recorded between pi mean and the prepared questions, and with mean of children with good knowledge. these results give an indication that those children had good dental knowledge, but they lack attitude to change their behavior toward application of oral hygiene measures to improve their oral health. questions age groups correlations 6-8 9-11 12-14 total dmfs dmfs pi no. % no. % no. % no. % r sig r sig. r sig. q1 60 74.07 35 81.39 27 69.23 122 74.84 0.02 not 0.00 not 0.06 not q2 49 60.49 34 79.06 23 58.97 106 65.03 0.03 not 0.10 not 0.05 not q3 40 49.38 29 67.44 22 56.41 91 55.82 0.04 not 0.07 not 0.01 not q4 52 64.19 28 65.11 23 58.97 103 63.19 0.05 not 0.03 not 0.08 not q5 36 44.44 19 44.18 15 38.46 70 42.94 0.07 not 0.07 not 0.01 not q6 36 44.44 30 69.76 29 74.35 95 58.28 0.23* sig. 0.24* sig. 0.05 not q7 54 66.66 29 67.44 29 74.35 112 68.71 0.08 not 0.14 not 0.12 not q8 56 69.13 34 79.06 28 71.79 118 72.39 0.10 not 0.18 not 0.20 not q9 44 54.32 28 65.11 18 46.15 90 55.21 0.04 not 0.00 not 0.09 not q10 48 59.25 30 69.76 22 56.41 100 61.34 0.02 not 0.00 not 0.04 not good dental knowledge (scores 5) 50 61.72 33 76.74 26 66.66 124 76.07 0.12 not 0.22* sig. 0.05 not j bagh college dentistry vol. 27(4), december 2015 oral health status pedodontics, orthodontics and preventive dentistry 142 references 1. who. meaning of oral health. world health organization. 2015. 2. kotch j. maternal and child health. 3rd ed. burlington: jones and bartlett learning; 2013. 3. ashton q. issues in dentistry, oral health, odontology and craniofacial research. atlanta, georgia: scholary edition; 2013. 4. berg h, rebecca l. early childhood oral health. wilyblackwell; 2009. 5. harris no, garcia-godoy f, nathe cn. primary preventive dentistry. 8th ed. boston: pearson education inc.; 2013. 6. murray j, nunn j, steele j. the prevention of oral disease. 4th ed. oxford: university press; 2003 7. marya c. a textbook of public health dentistry. new delhi: jaypee brothers medical publishers; 2011. 8. parshanth s, bhatnagar s, gopu h. oral health knowledge, practice, oral hygiene status and dental caries prevalence among visually impaired children in bangolare. j indian pedod prev dent 2011; 29 (2): 102-5. 9. saied-moallemi z, virtanen j, ghofranipour f, murtomaa h. influence of mothers’ oral health knowledge and attitudes on their children’s dental health. eur arch pediat dentistry 2008; 9(2): 79-83. 10. silness j, löe h. periodontal disease in pregnancy ii correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22: 121-35. 11. löe h, silness j. periodontal disease in pregnancy. i prevlence and severity. acta odontol scand 1963; 21: 533-51. 12. ramfjored sp. indices for prevalence and incidence of periodontal disease. j periodontol 1959; 30: 51-9. 13. who. oral health surveys basic methods. 4th ed. world health organization. geneva, switzerland, 1997. 14. damle sg. text book of pediatric dentistry. 3rd ed. new deli: arey (medi) publishing house; 2009. 15. fejerskov o, kidd e. dental caries: the disease and its clinical management. 2nd ed. oxford: blackwell munksgaard; 2008. 16. hara a, zero d. the caries environment: saliva, pellicle, diet and hard tissue ultrastructure. dent clin north am 2010; 455-67. 17. ashton q. gingivitis: new insight for the health care professional. atlanta. georgia: scholary edition; 2013. 18. reddy sh. essentials of clinical periodontology and periodontics. 2nd ed. new delhi: jaypee brothers publishers; 2008. 29. suha f.doc j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 175 the effect of orthodontic force on salivary levels of alkaline phosphatase enzyme suha ali abdul ameer, b.d.s., m.sc. (1) akram faisal alhuwaizi, b.d.s., m.sc., ph.d. (2) abstract background: orthodontic tooth movement is characterized by tissue reactions, which consist of an inflammatory response in periodontal ligament and followed by bone remodeling in the periodontium depending on the forces applied. these processes trigger the secretion of various proteins and enzymes into the saliva.the purpose of this study was to evaluate the activity of alkaline phosphatase (alp) in saliva during orthodontic tooth movement using different magnitude of continuous orthodontic forces. materials and methods: thirty orthodontic patients (12 males and 18 females) aged 17-23 years with class ii division i malocclusion all requiring bilateral maxillary first premolar extractions were randomly divided into three groups according to the magnitude of the force application (40, 60 and 80gm). a sectional fixed appliance was bonded and designed to give labial force to the maxillary first premolar for three weeks. unstimulated saliva was collected from the patients before force application, then 1 hour after force application, followed by 1 day, 7 days, 14 days and 21 days.salivary levels of alp were measured using spectrophotometer and compared with the baseline level. results: the results revealed that alp enzymelevel increased with increasing magnitude of orthodontic force (from 40 to 80gm). this was statistically insignificant after 1 hour and 1 day of force application, but significant after 7, 14 and 21 days.the alp level significantly increased from baseline after 7 days of force application and peaked at 21 days for all the three force levels. conclusions: the alp level reflect the biological activity that takes place in the periodontium during orthodontic tooth movement, and therefore they can be used as a diagnostic tool for monitoring of correct orthodontic tooth movement in clinical practice. key words: alkaline phosphatase, orthodontic tooth movement, orthodontic force. (j bagh coll dentistry 2015; 27(4):175-179). introduction orthodontic tooth movement constitutes a highly complex process defined as an adaptive biological response to interference in the physiological equilibrium in the dentofacial structures by an externally applied force (1). the host response to orthodontic force has been described as an aseptically and transitory inflammation that mainly alters the vascularity and blood flow of periodontal ligament, resulting in local synthesis and release of different mediators involved in alveolarbone remodeling(2,3). progress of tooth movement can be classified into four stages, that is, activation, resorption, reversal, and restructuring of new bones (4). an early response to orthodontic force is acute inflammation followed by bone resorption and formation. the resorption and formation ofbone are due to increments of activities of osteoclast and osteoblast cells (5). in order to monitor orthodontic tooth movement non-invasively in human beings, changes have been examined in the profile and levels of various enzymes, cytokines, growth factors, biomarkers and proteoglycans in gingival crevicular fluid and saliva. (1) assistant lecturer, department of dentistry, al-rafidain university college. (2) professor, department of orthodontics, college of dentistry, university of baghdad. among those components that change and response to orthodontic force are alkaline phosphatase (alp), tartrate resistance acid phosphatase (trap), lactate dehydrogenase (ldh), and aspartate amino transferase (ast)(6,7). application of continuous force produces bone resorption and formation at the pressure area with increased activities of both alkaline phosphatase (alp) and lactate dehydrogenase (ldh) (8,9). although the clinical and radiographic followup examination remains the basis for patient’s evaluation, analysis of saliva, a fluid that contains local and systemically derived markers, may offer the basis for a phase-specific screening of orthodontic tooth movement (10). the increase in osteoblastic activity during bone formation will be accompanied by an increased expression of an enzyme called alkaline phosphatase(11). to investigate the bone remodeling pattern based on alp activity during an orthodontic treatment, body fluids such as saliva can be used (5). the identification of salivary biomarkers and its use as a diagnostic tool has many advantages. it is much easier to collect, sufficient quantities can be easily obtained for analysis and no specific laboratory devices are necessary. the collection of saliva is also far less invasive compared to other body fluids such as gingival crevicular fluid and serum (12). j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 176 materials and methods subject selection: thirty patients (12 males and 18 females) were included in this study; who were attending the postgraduate clinic of the orthodontic department in the college of dentistry, university of baghdad. all patients had angle's class ii division 1 malocclusion with no or mild crowding (about 2-3mm). they all required bilateral extraction of maxillary first premolar teeth as part of their orthodontic treatment.inclusion criteria included age 17-23 years, good general health with no history of any systemic disease, no use of antiinflammatory drugs before and during the study, no history of any oral habit, good oral hygiene, good periodontal health (probing depth values not exceeding 3 mm in the whole dentition and no radiographic evidence of periodontal bone loss seen in dental panoramic tomography). subjects were examined clinically 2 weeks before appliance placement and underwent a session of accurate ultrasonic scaling and polishing and received oral hygiene instructions. those patients were randomly divided into 3 groups according to magnitude of force application (40, 60 and 80 gm). placement of orthodontic appliance: the length of sectional arch wire used was about 50 mm which consist of two parts: the first part was 0.018 inch round stainless steel arch wire with 35mm length, 30mm horizontal end with included non-traumatic coil, the remaining 5mm vertical apically directed. the second part was 0.021x0.025 inch rectangular stainless steel straight wire with length 15mm, 10mm horizontal and 5mm vertical apically directed. the two vertical ends of both wires were welded by welding device in the lab, and act as stopper in front of molar tube to avoid unwanted movements. the first part (round) was inserted in the premolar bracket while the second part (rectangular) was inserted into the molar tube. orthodontic brackets and molar tubes were bonded to enamel surface of right and left maxillary first premolars and first molar respectively, using after acid-etching the enamel of teeth. when the bonding material was completely set, the sectional arch wire was checked inside the patient mouth with the vertical arm in touch with the mesial aspect of the molar tube. the arch wire was marked mesial to the first premolar bracket. then it was removed and a nontraumatic end was made mesially to the first premolar. after reinsertion, cinch back was made distal to the first molar. the arch wire was bent just mesial to the molar tube in a labial direction so that when ligated to the premolar bracket it will apply labial force on the tooth. this force was measured by a strain gauge. the arch wire was ligated to the premolar bracket by a stainless steel ligature. saliva collection: the patient was instructed not to eat or drink for at least 1 hour before collection of the sample. the patient was asked to sit in a comfortable position and spit or drool out unstimulated saliva into sterile plane plastic test tube for 10 minutes givingabout 5ml of unstimulated whole saliva and put in a cooling box to stop the growth of bacteria. the samples were taken from each patient immediately prior to fitting the orthodontic appliance at baseline, then after 1 hour, 1 day, 7 days, 14 days and 21 days after force application to the teeth. biochemical assay: after collection, the whole saliva was clarified by centrifugation for 20 minutes at 3000 rpm to remove insoluble material by using centrifuge machine the supernatants saliva were collected by pipette into eppendrof tubes and frozen at 20oc until biochemical analysis.the analyses of samples were done in the laboratories of the poison center of the specialized surgeries hospital to measure the concentrate of alp in saliva by colorimetric method (spectrophotometrically) at constant temperature of 37o c, with less than 0.05oc fluctuation. the test for serum-alkaline phosphatase enzyme was done by the use of commercial kit manufactured by bio mérieux sa/france. results the alp level under different continuous orthodontic force in the 3 groups at the 6 time intervals from baseline to 21 days is shown in table1. effect of force magnitude: from baseline to1 day of force application, the alp levels varied among the 3 groups with insignificantly (p 0.05) as shown in table 2. while, after 7 to21 days of force application, the level of alp varied among the groups with highly significant difference (p≤0.01) in which there was a clear increase of alp concentration with increased force magnitude (figure 1). after 7 days of force application, lsd test showed that there was no significant difference (p 0.05) between groups i and ii, while there was a highly significant difference (p≤0.01) between j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 177 groups i and iii, and between groups ii and iii (table 3). after 14and 21 days of force application, lsd test showed that there was significant differences between groups i and ii, groups i and iii and between groups ii and iii (table 3). effect of time duration of force: in each group, after 1 hour of force application, the alp level slightly increased when compared to the baseline.while after 1 day of force application, the alp level slightly decreased. after 7 days the alp level increased and reached at peaked in 21 days as (table 1). these differences were highly significant for the 3 groups (p≤0.01) (table 4). for the 3 groups, lsd test showed that the differences between baseline, 1 hour and 1 daywerestatistically insignificant. whereas the differences between 1 day, 7 days, 14 days and 21 days were statistically significant (table 5). table (1): descriptive statistics of the salivary enzyme alp level (iu/l). duration group i (40gm) group ii (60gm) group iii (80gm) mean s.d. mean s.d. mean s.d. baseline 15.15 2.34 14.76 2.35 14.24 2.38 1 hr 15.24 2.30 14.81 2.35 14.27 2.33 1 day 14.65 2.23 13.71 2.59 13.50 2.44 7 days 16.86 2.00 17.62 1.89 20.24 1.89 14 days 20.27 0.94 22.45 2.08 29.29 2.09 21 days 22.66 1.28 28.96 3.69 39.24 1.73 table (2): difference between the groups for alp levels (iu/l) at the 6 time intervals using anova test. duration f-test d.f. p value sig. baseline 0.37 29 0.692 ns 1 hr 0.44 29 0.649 ns 1 day 0.63 29 0.538 ns 7 days 8.45 29 0.001 hs 14 days 69.32 29 0.000 hs 21 days 115.21 29 0.000 hs ns: non-significant (p>0.05) hs: highly significant (p≤0.01) figure (1): alp level iu/l for the three groups at the six time intervals. table (3): difference between the groups for alp levels (iu/l) at the 6 time intervals using lsd test. duration groups mean difference s.e. p-value sig. 7 days i ii -0.76 0.86 0.385 ns iii -3.38 0.86 0.001 hs ii iii -2.62 0.86 0.005 hs 14 days i ii -2.17 0.80 0.011 s iii -9.02 0.80 0.000 hs ii iii -6.84 0.80 0.000 hs 21 days i ii -6.30 1.10 0.000 hs iii -16.58 1.10 0.000 hs ii iii -10.28 1.10 0.000 hs ns: non-significant (p>0.05), s: significant (p≤0.05), hs: highly significant (p≤0.01) table (4): difference between the six time intervals for alp levels iu/l for the three groups using anova test. groups f-test d.f. p-value sig. group i (40 mg) 28.85 59 0.000 hs group ii (60 mg) 53.87 59 0.000 hs group iii (80 mg) 233.27 59 0.000 hs hs: highly significant (p≤0.01) table (5): difference between the alp levels (iu/l) between consecutive time intervals using lsd test duration group i group ii group iii p value sig. p value sig. p value sig. baseline 1 hr 0.912 ns 0.961 ns 0.977 ns 1 hr 1 day 0.492 ns 0.339 ns 0.431 ns 1 day 7 days 0.013 s 0.001 hs 0.000 hs 7 days 14 days 0.000 hs 0.000 hs 0.000 hs 14 days 21 days 0.008 hs 0.000 hs 0.000 hs ns: non-significant (p>0.05), s: significant (p≤0.05), hs: highly significant (p≤0.01) j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 178 discussion orthodontics is based on the application of prolonged forces on teeth. various degrees of force magnitude, frequency, and duration of orthodontic treatment exert a great influence on the surrounding tissue reaction and bone modeling. interaction between bone formation and resorption during tooth movement results in the release of various biochemical or cellular mediators that can be identified as potential biomarkers (13). many studies have investigated possible biomarkers for bone modeling during orthodontic tooth movement such as alp enzyme which has been associated with bone formation(14-18). effect of force: in bone modeling process, bone formation occurs between first and second weeks at sites of both tension and pressure. bone formation has been shown to be represented by the expression of alp (18). during bone formation, osteoblasts express alp (11). therefore, the alp detected in saliva is from the action of osteoblast during bone formation surrounding the teeth. expression of alp reflects the biochemical changes that occurs in the supporting tissue after the application of an orthodontic force (19). therefore, by monitoring the changes in alp enzymatic activity, the force application during orthodontic treatment can be customized according to the patient’s needs. in the present study, the salivary alp level increased with increasing the magnitude of the force and this in agreement with hong-fei et, al.,(20) who reported that there was direct effect of mechanical strain magnitude on alp level. however, there was an insignificant decrease in alp level after 1 day of force application which disagrees with previous studies (14,21). this could be attributed to the differences in the sampling methods/protocols, processing methodology, sensitivity/specificity of the immunoassays, differences in the type of orthodontic mechanotherapy, force levels, and sample size. effect of time: in the present study, the level of alp in the 3 groups significantly increased after 7 to 21 days of orthodontic force application. this may be due to that after orthodontic force application, both bone formation and resorption occur in respective tension or compression sites in order to maintain the integrity of the alveolar bone that holds the dentition. this can be supported by the findings of other studies (11,22) who exhibited that bone formation could be represented by the expression of alp.furthermore, during orthodontic force application, there will be destruction of alveolar bone osteoblasts and fibroblasts and their cell membrane will be ruptured releasing their intracellular contents outside. therefore, alp will be released into gingival crevicular fluid and saliva and the level of alp will increase in saliva. this was confirmed by the previous (23,24). the level of alp, in this study, significantly increased after 7, 14 and 21 days of orthodontic force application in all 3 groups.this agrees with several authors (14,15,22,25-27)who reported that alp increased at 1,2 and 3 weeks after force application. clinical significance: the bony turnover, specifically the bone formation, can be monitored through the expression of alp level in saliva during orthodontic treatment. low forces and small tooth movements during treatment may contribute to the low levels of alp, while high orthodontic forces produce faster tooth movements, as indicated by the significant increases in salivary level alp activity at 7th, 14th and 21st days during the treatment. altogether, these salivary finding might be a reflection of the actual enzymatic profile of gingival crevicular fluid and consequently of the biologic activity within the periodontal environment during orthodontic tooth movement. references 1. proffit wr, fields hw, sarver dm. contemporary orthodontics. 5th ed. st. louis: mosby, inc., an affiliate of elisiver inc.; 2013. 2. garlet tp, coelho u, repeke ce, silva js, cunha fdq, garlet gp. differential expression of osteoblast and osteoclast chemmoatractants in compression and tension sides during orthodontic movement. cytokine 2008; 42(3): 330-5. 3. krishnan v, davidovitch z. a path to unfolding the biological mechanisms of orthodontic tooth movement. j den res 2009; 88: 597-608. 4. keeling sd, king gj, mccoy ea, valdez m. serum and alveolar bone phosphatase changes reflect bone turnover during orthodontic tooth movement. am j orthod dentofac orthop 1993; 103(4): 320-6. 5. shahrul hza, mohd fe, rohaya maw, yosni b, sahidan s. profiles of lactase dehydrogenase, tartrate resistant acid phosphatase and alkaline phosphatase in saliva during orthodontic treatment. sains malaysiana 2010; 39(3): 405-12. 6. grieve wg, johnson gk, moore rn, reinhardt ra, dubois lm. prostaglandin e (pge) and interleukin-1 beta (il-1 beta) levels in gingival crevicular fluid during human orthodontic tooth movement. am j orthod dentofac orthop 1994; 105(4): 369-74. j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 179 7. waddington rj, embery g. proteoglycans and orthodontic tooth movement. j orthod 2010; 28(4): 281–90. 8. oliveira bl, faltin rm, arana-chavez ve. ultra structural and histochemical examination of alveolar bone at the pressure areas of rat molars submitted to continuous orthodontic force. eur j oral sci 2003; 111:410-6. 9. rohaya maw, hisham sza, khazlina k. preliminary study of aspartate aminotransferase activity in gingival crevicular fluids during orthodontic tooth movement. japp sci 2009; 9(7):1393-6. 10. flórez-moreno ga, marín-restrepo lm, isazaguzmán dm, tobón-arroyave si. screening for salivary levels of deoxypyridinoline and bone-specific alkaline phosphatase during orthodontic tooth movement: a pilot study. eur j orthod 2013; 35(3): 361-8. 11. intan zza, shahrul h, rohaya maw, sahidan s, zaidah za.osteoclast and osteoblast development of musculus haemopoietic mononucleated cells. j biol sci 2008; 8(3):506-16. 12. zhang j, zhou s, zheng h, zhou y, chen f, lin j. magnetic bead-based salivary peptidome profiling analysis during orthodontic treatment durations. biochem and biophyl res commun 2012; 421(4): 844-9. 13. krishnan v, davidovitch z. cellular, molecular, and tissue-level reactions to orthodontic force. am j orthod dentofac orthop 2006; 129(4):462-7. 14. perinetti g, varvara g, festa f, esposito p. alkaline phosphatase activity in gingival crevicular fluid during human orthodontic tooth movement. am j orthod dentofac orthop 2002; 122: 548-56. 15. perinetti g, paolantonio m, serra e. longitudinal monitoring of subgingival colonization by actinobacillusactinomycetemcomitans, and crevicular alkaline phosphatase and aspartate aminotransferase activities around orthodontically treated teeth. j clin period 2004; 31(1):60-7. 16. abidin izz, ariffin shz, ariffin zz, wahab rma. potential differentiation of three types of primitive cellsoriginated from different proliferation terms of mouse blood. sains malaysiana 2010; 39(2): 305-13. 17. yazid md, ariffin shz, senafi ss, razak mr, wahab rma. determination of the differentiation capacities of murines’ primary mononucleated cells and mc3t3-e1 cells. cancer cell int 2010; 10(42):10-42. 18. asma aaa, rohaya maw, shahrulhisham za. pattern of crevicular alkaline phosphatase during orthodontic tooth movement: leveling and alignment stage. sains malaysiana 2011; 40(10):1147-51. 19. dhopatkar aa, sloan aj, rock wp, cooper pr, smith aj. a novel in vitro culture model to investigate the reaction of the dentine-pulp complex to orthodontic force. j orthod 2005; 32:122-32. 20. hong-fei lu, zhi-hui mai, wei wang, hong ai. mechanical loading induced expression of bone morphogenetic protein-2, alkaline phosphatase activity, and collagen synthesis in osteoblastic mc3t3-e1 cells. chin med j 2012; 125(22): 4093-7. 21. batra p, kharbanda o, duggal r, singh n, parkash h. alkaline phosphatase activity in gingival crevicular fluid during canine retraction. orthod & craniofac res 2006; 9(1): 44–51. 22. bonafe-oliveira lb, faltin rm, chavez vea. ultrastructural and histochemical examination of alveolar bone at the pressure areas of rat molars submitted to continuous orthodontic force. eur j oral sci 2003; 111(5):410-6. 23. numabe y, hisano a, kamoi k, yoshie h, kurihara h. analysis of saliva for periodontal diagnosis and monitoring. j period 2004; 40:115-9. 24. ozmeric n. advances in periodontal disease markers. clin chim acta j 2004; 343(12):1-16. 25. insoft m, king gj, keeling sd. the measurement of acid and alkaline phosphatase in gingival crevicular fluid during orthodontic tooth movement. am j orthod dentofac orthop 1996; 109: 287-96. 26. asma aaa, rohaya maw, hisham s. crevicular alkaline phosphatase activity during orthodontic tooth movement: canine retraction stage. j med sci 2008; 8: 228-33. 27. abdul wahab rm, dasor mm, senafi s, abdullah aaa, yamamoto z, jemain aa, ariffin shz. crevicular alkaline phosphatase activity and rate of tooth movement of female orthodontic subjects under different continuous force applications. int j dentistry 2013; 10(1155): 245818-7. j bagh college dentistry vol. 30(2), june 2018 bacterial contamination restorative dentistry 1 bacterial contamination of acrylic resin complete denture/ in vitro study cheman abdulrahman al-jmoor. bds, m.sc(1) abstract background: cross contamination of dental appliances in the dental clinics and laboratories may potentially be a health hazard to the dental team and the patient. this study aimed to evaluate bacterial contamination of acrylic complete denture as received from dental laboratory before delivery to the patient, and then to evaluate the effectiveness of disinfection with 2% chlorhexidine and kin denture cleaner tablet. materials and methods: 45 newly made upper complete dentures undergone biaacterial examination for contamination before delivered to the patient. samples were examined in two stages, first after finishing and polishing; when collected from the laboratory and before inserting to the patient mouth, second; after the samples were immersed in 2 different disinfectant materials, 2% chlorhexidine mouth wash and kin denture cleaner tablet. after initial stage, the dentures were divided into 3 groups. group 1 immersed in kin denture cleaner tablet for 10 minutes, group 2 immersed in 2% chlorhexidine mouth wash for 10 minutes and group 3 immersed for 20 minutes in 2% chlorhexidine. data were analyzed with a computer-run statistical program (ibm spss version 23). results: high score of bacterial contamination was found initially in the sample collected from dental laboratory. significant reduction in the colonies number was noticed after immersing the dentures in 2% chlorhexidine and kin denture cleaner tablets for10 minutes. there was nearly no contamination found with samples immersed in 2% chlorhexidine for 20 minutes. conclusion: dental laboratory is a main source of microbial contamination. immersion of the dental prosthesis in disinfectant materials is essential before inserting into the patient mouth. 2%chlorhexidine mouth wash was more effective as disinfection material as compared to kin denture cleaner tablet. keywords: denture cleaner tablets, 2% chlorhexidine, prosthesis microbial contamination. (j bagh coll dentistry 2018; 30(2):1-4) introduction acrylic resins are commonly used for complete denture fabrication since they exhibit adequate physical, mechanical, and esthetic properties. there are several routes of microbial contamination in dental laboratories, including the felt disks and pumice used in the polishing process and contact with contaminated hands. other forms of contamination occur when prostheses are sent to dental offices for adjustments or repairs, because in certain steps of treatment, these materials may be contaminated by microorganisms from the patient’s mouth (1). considering the cross contamination between the dental operator and the dental laboratory, dental prostheses should be disinfected before delivering to the patient and before sending it back to the dental laboratory (2). recent studies showed that appliances received from laboratories are often contaminated and therefore there is a need for routine disinfection of such items before use and a review of storage conditions required (3). an effective method to clean dental prosthesis surface and control microbial growth is the periodic mechanical disruption of the biofilm formed on the denture surfaces. however, because acrylic resins are thermo-sensitive materials, the use of chemical disinfectants is necessary (4). (1) lecturer, department of prosthodontics, college of dentistry, university of sulaimani chemical cleaning consists of immersion of the prosthesis in solutions containing chemical agents. the chemical agent must be safe to be used in disinfection since it might be released in the oral cavity when prosthesis is back into the patient mouth, they should be biocompatible, inexpensive, effective against pathogenic microorganisms, non-toxic and harmless to the structure of the prosthesis and have no cytotoxic effect when used for denture chemical disinfection. (4) (5). the safety of the use of solutions as chlorhexidine, sodium hypochlorite, vinegar and hydrogen peroxide is reported in the literature (6). in the last few years, chlorhexidine has been one of the most studied antimicrobial substances and has shown great efficacy in disinfection of removable prosthesis (5) (7). the use of a cleansing tablet on the other hand as disinfectant materials for removable dental prosthesis showed good efficacy in reducing bacterial contamination. in 2010, silva-lovato assessed the efficacy of cleaning tabs on plaque removal and antimicrobial action on complete dentures. it was observed that cleaning tabs showed a significant lower percentage of biofilm and a reduction of yeast colonies on the prosthesis compared to the control group. based on their results, the authors concluded that the use of cleaning tabs can be recommended as a standard cleaning protocol (8). j bagh college dentistry vol. 30(2), june 2018 bacterial contamination restorative dentistry 2 a recent study showed a decrease of total bacterial load and of specific bacteria when the dentures were stored in water with an effervescent denture cleaner tablet and reduced the total bacterial count on acrylic removable dentures (9), they significantly reduced the total bacteria count, and this effect was more pronounced in case of ultrasonic cleaning. the purpose of this study is to evaluate bacterial contamination of acrylic complete denture received from dental laboratory before being delivered to the patient, and to compare the effectiveness of disinfection with 2% chlorhexidine mouth wash and kin denture cleaner tablet. materials and methods: the study is an in vitro experimental method, the sample consists of 45 acrylic upper complete dentures, the newly made 45 dentures were taken from the dental lab after finishing and polishing stored in plastic bag filled with tap water. the first part of the study the whole sample underwent bacterial examination by taking randomized swab from the denture surface and seeded on a nutrient agar plate. nutrient agar was used as it is a general culture media for gram negative and gram positive bacteria, the seeding was done by spreading of 0.01 ml of the bacterial growth on the nutrient agar surface, and then incubate in an incubator* in 37co for 24 hours, then bacterial colonies number were counted and recorded. the level of contamination was demonstrated by the number of colony forming units (cfus) from the positive samples. after taking the swab from each sample in the initial stage of examination, the samples were returned back to their sealed bags. in the second stage of bacterial contamination, the 45 samples were divided into three groups, each of 15 dentures, then the second part of the study accomplished. group 1 was immersed in solution prepared from kin denture cleaner** tablet after been dissolved in distill water according to manufacturer’s instructions for 10 minutes , group 2 was immersed in 2% chlorhexidine for 10 minutes, and group3 was immersed in 2% chlorhexidine for 20 minutes. in the second stage of samples examination, each sample were taken out of their sealed bags, washed with distill water, and then immersed in the allocated disinfectant material. a swab was taken from each sample and was seeded on nutrient agar, the same procedure of the initial stage of incubation and bacterial colonies counting were followed. the baseline conditions of the prosthesis for all test period were as standardized as possible and all measures were taken to achieve an optimal disinfection of the prostheses at the star t of each test period. data were analyzed with a computer-run statistical program (ibm spss version 23). the recorded data were first included in the normality test which indicates the data as parametric data, accordingly independent sample t-test at the significance level of 0.05 was applied to the groups to determine statistical difference between two means. * jrad type incubator. ** kin denture cleaner tablet ingredient: potassium peroxy monosulfate (caroate), sodium carbonate, citric acid, sodium lauryl sulfate, other ingredients. results obvious differences were recorded in the mean and the standard deviation of all the samples at the initial stage, and after immersion in disinfected materials for different time intervals table -1 and 3. the efficacy of 2% chlorhexidine mouthwash and kin denture cleaner tablet in the reduction of the number of colony forming units (cfu) is described in figure -1. the result revealed significant differences in the total bacterial colony count after immersion in 2% chlorhexidine and the denture cleaner tablets, as compared to their count at the initial stage (p < 0.05), according to one sample student t-test., table -2 and 4 respectively. significant reduction in the total bacterial colony count was noticed after 10 minutes immersion in 2% chlorhexidine mouthwash as compared to samples immersed in the denture cleaner tablet ( p < 0.05) as depicted in table 4. there was very significant reduction of the bacterial colonies number to fewer than 20 when the samples were immersed in 2% chlorhexidine for 20 minutes, which could be regarded according to microbiological interpretation almost zero contamination table 3 and 4. the efficacy of the disinfectant material in the reduction of the number of colony forming units (cfu) within the three groups is shown in figure 1. table 1. descriptive statistics of all the samples at the initial stage of microbial examination. n mean std. dev. variance the samples at initial stage 45 989.444 ±353.808 125180.343 valid n (list wise) 45 table 2. one-sample test for the initial stage. t df sig. (2-tailed) mean difference 95% confidence interval of the difference lower upper 18.760 44 0.000 989.444 883.148 1095.740 j bagh college dentistry vol. 30(2), june 2018 bacterial contamination restorative dentistry 3 table 3. descriptive statistics for the 3 groups n mean std. dev. variance d.c. after_10_min 15 61.533 62.602 3918.981 ch. after_10_min 15 134.067 36.794 1353.781 ch. after_20_min 15 16.667 1.799 3.238 valid n (listwise) 15 table 4. one-sample test t df sig. (2-tailed) mean difference 95% confidence interval of the difference lower upper d.c. after_10_min 3.807 14 0.002 61.533 26.866 96.201 ch. after_10_min 14.112 14 0.000 134.067 113.691 154.442 ch. after_20_min 35.872 14 0.000 16.667 15.670 17.663 figure 1. the recorded cfu (colony forming units) of the 3 groups after using of the disinfectant materials. discussion the result of the present study showed that all the samples which was received from the laboratory were highly contaminated with different levels of contaminations, table-1, this result came in agreement with the result of recent study on acrylic resin removable orthodontics device constructed in dental laboratories, in which 85% of the received orthodontics devices were contaminated before been inserted into the patient mouth (10). the chemical agents used in the present study to reduce microorganism colonization, 2% chlorhexidine mouth wash, and denture cleaner tablet were very efficient in reducing the total microbial colonies count of the dentures when immersed for 10 minutes. this result is in agreement with the results obtained in previous study on overnight storage condition in alkaline peroxide on biofilm formation and maturation the study revealed that the use of cleansing tablets significantly reduced denture biofilm mass and pathogenicity compared to dry storage and storage in tap water in case of poor oral hygiene (11). the effect of denture cleaner tablet in the previous study was similar to the result of the present study in regard to the use of the denture cleaner tablet which showed a significant difference (p < 0.05) when was used as a disinfection material for acrylic resin complete denture. the result of the present study revealed that 2% chlorhexidine mouth wash is more efficient in reducing the total account of microbial colonies as compared to the denture cleaner tablet (p < 0.05) when immersed for 10 minutes. the efficient effect of 2% chlorhexidine as denture disinfectant was showed by another study which concluded that: chlorhexidine is considered to be the best for dental biofilm control and also used against various dental diseases like stomatitis, gingivitis etc. further immersion of the dentures samples for 20 minutes in 2% chlorhexidine mouthwash in the present study support this finding, as the microbial colonies account was reduced to less than 20 colonies figure-1, 0 50 100 150 200 250 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 denture cleaner after 10 min 2% chlorhexidine after 10 min 2% chlohexidine after 20 min figure 1. the recorded cfu (colony forming units) of the 3 groups after using of the disinfectant materials j bagh college dentistry vol. 30(2), june 2018 bacterial contamination restorative dentistry 4 this result could be interpreted as a sample with no contamination from microbiological point. conclusion dental laboratory is a main source of microbial contamination. this hypothesis was proved in the study, as all the samples that were collected from the dental laboratory, and before been inserted into the patient mouth was contaminated. using of disinfectant protocols is essential and mandatory in the dental clinic, as well as in the dental laboratory and before being inserted into the patient’s mouth at any stage during the construction of the a dental prosthesis, especially removable prosthesis, to control cross infection between dental staff, and the patient. immersion of the dental prosthesis for 10 minutes in 2% chlorhexidine mouth wash and denture cleaner tablet lead to significant reduction in the microbial contamination. 2%chlorhexidine mouth wash was more effective as disinfection material as compared to denture cleaner tablet. acknowledment the author thanks dr dlnya asad mohamad, assistant professor of molecular biology (pharma gene laboratory, sulaimani city), for her appreciated assistant in doing the bacterial examination experiment of the research, and her help during the study. references: 1. balaji smriti, muralidharan n.p. effectiveness of 4 different disinfectants in removing 2 microorganisms from acrylic resins. int. j. pharm. sci. rev. res. 2016, 40(2): 83-85. 2. carvalho cf, vanderlei ad, marocho sm, pereira sm, nogueira l, paes-júnior tj.. effect of disinfectant solutions on a denture base acrylic resin. acta dontológica. 2012, 25(3): 255-260. 3. williams d. w., chamary n., lewis m. a. o., . milward p. j, mcandrew r.. microbial contamination of removable prosthodontic appliances from laboratories and impact of clinical storage. brit dent.j. 2011 aug 27. volume 211, no. 4. 4. chassot al, poisl mi, samuel sm. in vivo and in vitro evaluation of the efficacy of a per acetic acid-based disinfectant for decontamination of acrylic resins. brazi dent j. 2006; 17:117-21. 5. ln hashizume; hoscharuk, murilo fernandes and moreira, maurício josé santos. effect of affordable disinfectant solutions on candida albicans adhered to acrylic resin for dental prosthesis, rgo, rev gaúch odontol, porto alegre. 2015,63(3), 309-314 6. montagner h, montagner f, braun ko, peres pe, gomes bp. in vitro antifungal action of different substances over microwaved cured acrylic resins. j appl oral sci. 2009; 17(5):432-5. 7. andr, rf, andrade im, silva-lovato ch, paranhos hde f, pimenta fc, ito iy. prevalence of mutans streptococci isolated from complete dentures and their susceptibility to mouth rinses. brazi dent j, 2011, 22:62-67 8. silva-lovato, , wever bd, adriaens e, paranhos hde f, watanabe e, pisani mx, souza rf, ito iy. clinical and antimicrobial efficacy of nitradinetm-based disinfecting cleaning tablets in complete denture wearers. j appl oral sci. 2010; 18(6): 560–565. 9. duyck j, vandamme k, krausch-hofmann s1, boon l, de keersmaecker k1, jalon e. impact of denture cleaning method and overnight storage condition on denture biofilm mass and composition: a cross-over randomized clinical trial. 2016. 10. larissa vanessa gomes moreira , ana gláucia de oliveira macedo, anderson farias da cunha , olga benario vieira maranhao , maria regina macêdo-costa , kenio costa de lima, sergei godeiro fernandes rabelo caldas, hallissa simplício gomes pereira . microbial contamination of orthodontic appliances made of acrylic resin. afric j of microbiology resear. 2016, 10(27), 1051-1055 11. duyck j, vandamme k, muller p, teughels w. overnight storage of removable dentures in alkaline peroxide-based tablets affects biofilm mass and composition. j dent. 2013; 41: 1281–1289. الخالصة : الدراسة إلى تقييم التلوث الجرثومي ألطقم األسنان قد يحتمل أن يشكل تلوث أجهزة طب األسنان في عيادات ومعامل األسنان خطًرا صحيًا على فريق األسنان والمريض. هدفت هذه من الكلورهيكسيدين وحب تنظيف وتعقيم طقم األسنان ماركة ٪2األكريليكية الكاملة كما وردت من مختبر األسنان قبل تسليمها إلى المريض ، ومن ثم تقييم فعالية التطهير باستخدام كين. لتلميع. األسنان الكاملة الحديثة الصنع لفحص البكتيريا للتلوث قبل تسليمها إلى المريض. تم فحص العينات على مرحلتين ، أوال بعد االنتهاء وامن أطقم 54خضع المواد واألساليب: وحب كين لتنظيف أطقم األسنان. بعد كلورهيكسيدين غسول الفم ٪ 2مواد مطهرة مختلفة ، 2عند جمعها من المختبر وقبل إدخالها في فم المريض ، بعد أن تم غمر العينات في كلورهيكسيدين غسول الفم ٪ 2مغمورة في 2دقائق ، المجموعة 11مغمورة في قرص كين دنتير منظف لمدة 1مجموعات. المجموعة 3المرحلة األولية . تم تقسيم أطقم األسنان إلى ibm spss versionيدين. تم تحليل البيانات باستخدام برنامج إحصائي يتم تشغيله بواسطة الكمبيوتر )الكلورهيكس ٪ 2دقيقة في 21مغمورة لمدة 3دقائق والمجموعة 11لمدة 23.) م المستعمرات بعد غمر في طقتم العثور على درجة عالية من التلوث البكتيري في البداية في العينة التي تم جمعها من مختبر األسنان. وقد لوحظ انخفاض كبير في عدد النتائج: دقيقة. 21لمدة ٪ 2دقيقة. لم يكن هناك تقريبا أي تلوث وجدت مع عينات مغمورة في الكلورهكسيدين 11أقراص الكلورهيكسيدين وأقراص نظافة لمدة ٪ 2األسنان في ٪ 2د المطهرة ضروري قبل إدخالها في فم المريض. كان مختبر األسنان هو المصدر الرئيسي للتلوث الميكروبي. غمر األسنان االصطناعية وأطقم األسنان في الموا :االستنتاج كلورهكسيدين ، تلوث الجرثومي ٪ 2كلمات البحث: أقراص أنظف طقم األسنان ، كلورهيكسيدين غسول الفم أكثر فعالية كمادة تطهير بالمقارنة مع قرص نظافة كين. https://www.ncbi.nlm.nih.gov/pubmed/?term=carvalho%20cf%5bauthor%5d&cauthor=true&cauthor_uid=23798071 https://www.ncbi.nlm.nih.gov/pubmed/?term=vanderlei%20ad%5bauthor%5d&cauthor=true&cauthor_uid=23798071 https://www.ncbi.nlm.nih.gov/pubmed/?term=marocho%20sm%5bauthor%5d&cauthor=true&cauthor_uid=23798071 https://www.ncbi.nlm.nih.gov/pubmed/?term=pereira%20sm%5bauthor%5d&cauthor=true&cauthor_uid=23798071 https://www.ncbi.nlm.nih.gov/pubmed/?term=nogueira%20l%5bauthor%5d&cauthor=true&cauthor_uid=23798071 https://www.ncbi.nlm.nih.gov/pubmed/?term=paes-j%c3%banior%20tj%5bauthor%5d&cauthor=true&cauthor_uid=23798071 http://www.scielo.br/cgi-bin/wxis.exe/iah/?isisscript=iah/iah.xis&base=article%5edlibrary&format=iso.pft&lang=i&nextaction=lnk&indexsearch=au&exprsearch=hoscharuk,+murilo+fernandes http://www.scielo.br/cgi-bin/wxis.exe/iah/?isisscript=iah/iah.xis&base=article%5edlibrary&format=iso.pft&lang=i&nextaction=lnk&indexsearch=au&exprsearch=moreira,+mauricio+jose+santos http://www.scielo.br/cgi-bin/wxis.exe/iah/?isisscript=iah/iah.xis&base=article%5edlibrary&format=iso.pft&lang=i&nextaction=lnk&indexsearch=au&exprsearch=moreira,+mauricio+jose+santos https://www.ncbi.nlm.nih.gov/pubmed/?term=wever%20bd%5bauthor%5d&cauthor=true&cauthor_uid=21308285 https://www.ncbi.nlm.nih.gov/pubmed/?term=adriaens%20e%5bauthor%5d&cauthor=true&cauthor_uid=21308285 https://www.ncbi.nlm.nih.gov/pubmed/?term=paranhos%20hde%20f%5bauthor%5d&cauthor=true&cauthor_uid=21308285 https://www.ncbi.nlm.nih.gov/pubmed/?term=watanabe%20e%5bauthor%5d&cauthor=true&cauthor_uid=21308285 https://www.ncbi.nlm.nih.gov/pubmed/?term=pisani%20mx%5bauthor%5d&cauthor=true&cauthor_uid=21308285 https://www.ncbi.nlm.nih.gov/pubmed/?term=souza%20rf%5bauthor%5d&cauthor=true&cauthor_uid=21308285 https://www.ncbi.nlm.nih.gov/pubmed/?term=ito%20iy%5bauthor%5d&cauthor=true&cauthor_uid=21308285 https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3881753/ https://www.ncbi.nlm.nih.gov/pmc/articles/pmc3881753/ https://www.ncbi.nlm.nih.gov/pubmed/?term=duyck%20j%5bauthor%5d&cauthor=true&cauthor_uid=26730967 https://www.ncbi.nlm.nih.gov/pubmed/?term=vandamme%20k%5bauthor%5d&cauthor=true&cauthor_uid=26730967 https://www.ncbi.nlm.nih.gov/pubmed/?term=boon%20l%5bauthor%5d&cauthor=true&cauthor_uid=26730967 https://www.ncbi.nlm.nih.gov/pubmed/?term=de%20keersmaecker%20k%5bauthor%5d&cauthor=true&cauthor_uid=26730967 https://www.ncbi.nlm.nih.gov/pubmed/?term=de%20keersmaecker%20k%5bauthor%5d&cauthor=true&cauthor_uid=26730967 https://www.ncbi.nlm.nih.gov/pubmed/?term=jalon%20e%5bauthor%5d&cauthor=true&cauthor_uid=26730967 ammar.doc j bagh college dentistry vol. 26(4), december 2014 cephalometric evaluation pedodontics, orthodontics and preventive dentistry163 cephalometric evaluation of a sample of iraqi adults with normal occlusion using tetragon analysis ammar sh. ahmed, b.d.s., m.sc. (1) abstract background: this study aimed to determine the cephalometric values of tetragon analysis on a sample of iraqi adults with normal occlusion. material and methods: forty digital true lateral cephalometric radiographs belong to 20 males and 20 females having normal dental relation were analyzed using autocad program 2009. descriptive statistics and sample comparison with fastlicht norms were obtained. results: the results showed that maxillary and mandibular incisors were more proclined and the maxillary/mandibular planes angle was lower in iraqi sample than caucasian sample. conclusion: it's recommended to use result from this study when using tetragon analysis for iraqis to get more accurate result. key words: cephalometrics, tetragon analysis. (j bagh coll dentistry 2014; 26(4):163-166). الخالصة اإلضالعمربع باستخدام تحلیل البالغین لعراقیینعینة من اتحدید معاییر قیاسات الرأس ل إلىتھدف ھذه الدراسة :الخلفیة للرسم األوتوكادبرنامج سني طبیعي باستخدام بإطباقجمیعھم یتمتعون ) إناث 20ذكور و 20(شخص عراقي ألربعین الجانبیة اإلشعاعیةتم تحلیل قیاسات الرأس : واألسالیبالمواد .2009 إصدارالھندسي .والزاویة بین الفك العلوي والسفلي اصغر في العینة العراقیة من العینة القوقازیة أكثر لإلمامأظھرت ھذه الدراسة أن القواطع العلویة والسفلیة في العینة العراقیة مائلة : النتائج .دقة أكثرالدراسة عند استخدام تحلیل التیتراكون للعراقیین للحصول على نتائج من المستحسن استخدام نتیجة ھذه :االستنتاجات قیاسات الرأس، تحلیل مربع األضالع: الكلمات الرئیسیة introduction the innovation of x-ray by roentegen in 1895 revolutionized the dental and medical career (1). broadbent and hofrath in 1931 started a new era in orthodontics by presenting the cephalometer (2). since then, it was used in orthodontics to study facial forms, development of norms, assessment of treatment prognosis and growth prediction for the individual patient allowing accurate evaluations of skeletal relations of patients with different types of malocclusion (3). many cephalometric analyses were evolved in an attempt to define the skeletal characteristics of a good face and good occlusion. researchers world-wide have paid attention to the ethnic factor and tried to establish cephalometric values for various ethnic groups (2). comparative cephalometric studies have proven that differences in the craniofacial morphology exist among races and ethnic groups. miyajima et al. (4) also noted that a patient might seek a treatment plan that is based in part on norms for his or her racial or ethnic group. on the other hand, naranjilla et al. (5) study suggested the need to treat patients from different racial and ethnic groups differently using cephalometric norms specific to each group. it is important to compare a patient's cephalometric findings with the norms for his or her ethnic group for an accurate diagnostic evaluation, while considering his or her treatment goals and needs (6). (1)assistant lecturer. department of pop, college of dentistry, university of mustansyria. in 2000, fastlicht (7) introduced the tetragon analysis to provide a clear picture of the maxilladento-mandibular structures within the craniofacial complex. prakash and shetty (8) applied this analysis on indian with different occlusal relationships. this study is the first in iraq that attempts to set the cephalometric values for a sample of iraqi adults with normal occlusion using tetragon analysis. materials and methods sample digital true lateral cephalometric radiographs belong to forty individuals (20 males and 20 females) with an age ranged between 18-25 years were included in this study. these radiographs were obtained from the department of orthodontics; college of dentistry, university of baghdad. the criteria used for sample selection were: 1. normal molar, canine and incisor relationship with normal overbite and overjet. 2. well-aligned upper and lower dental arches with minimal dental crowding (1-2 mm.). 3. no history of previous orthodontic treatment, prosthodontic treatment or facial surgery. 4. no history of facial trauma. methods every lateral cephalometric radiograph was analyzed using autocad program (2009) to measure the linear and angular measurement. linear measurements were divided by scale for each picture to overcome the magnification while angles were not affected by magnification. j bagh college dentistry vol. 26(4), december 2014 cephalometric evaluation pedodontics, orthodontics and preventive dentistry164 cephalometric landmarks landmarks used in this study were determined according to rakosi (1): 1. pt (pterygomaxillary fissure) 2. n (nasion) 3. s (sella turcica) 4. point a (subnasale) 5. point b (supramentale) 6. pog (pogonion) 7. go (gonion) 8. me (menton) 9. ans (anterior nasal spine) 10. pns (posterior nasal spine) 11. or (orbitale) 12. root apices and incisal edges of the most proclined maxillary and mandibular central incisors. linear measurements 1. n-pog-ui: the distance from the maxillary incisal edge and n-pog line 2. n-pog-li: the distance from the mandibular central incisor edges and n-pog line. 3. ui-pp: a perpendicular line from palatal plane (pp) through incisal edge of the maxillary central incisor, the measurements defines how far incisors are erupted in relation to palatal plane. 4. li-mp: a perpendicular line from mandibular plane (mp) through incisal edge of the mandibular central incisor. the measurements define how far incisors are erupted in relation to mandibular plane. angular measurements the tetragon has four sides, forming four angles that always equal to 360º (7) (fig. 1). 1. ui-pp: the angle between the palatal plane and the long axis of the maxillary central incisor. 2. ui-li: the angle between the maxillary and mandibular incisors long axes. 3. li-mp: the angle between the mandibular incisor long axis and the mandibular plane. 4. mp-pp: the angle between the mandibular plane and the palatal plane. 5. others: sna, snb and anb. the trigon has three sides, forming three angles that always equal to 180º (7) (fig. 2) 6. pt-or/pt-pns: the angle between the pt-or plane and pt-pns plane called "upper pt" 7. pt-pns/pp: the angle between the pt-pns and the palatal plane called "lower pt" 8. pt-or/pp: the angle between the pt-or plane and the palatal plane. statistical analyses all the data of the sample were subjected to computerized statistical analysis using spss version 18 computer program. the statistical analyses included: 1. descriptive statistics: including means, standard deviations (s.d), minimum and maximum values and statistical tables. 2. inferential statistics: one sample t-test was used to compare between the data from this study with the norms from fastlicht's study (7). in the statistical evaluation, the following levels of significance were used: non-significant ns p > 0.05 significant * 0.05 ≥ p > 0.01 highly significant ** 0.01 ≥ p > 0.001 very highly significant *** p ≤ 0.001 p= probability value. figure 1. the tetragon figure 2. the trigon j bagh college dentistry vol. 26(4), december 2014 cephalometric evaluation pedodontics, orthodontics and preventive dentistry165 results and discussion the tetragon analysis was introduced by fastlich (7) and based on two geometric constructs: the "tetragon", a polygon that represents the maxillo-dento-mandibular complex, made up of reliable and familiar cephalometric landmarks the palatal plane, the mandibular plane, and the axes of the maxillary and mandibular central incisors, and the "trigon", a complementary triangle situated above the tetragon and formed by one plane that is intrinsic to the tetragon-the palatal plane (pns-ans) and two that are extrinsic--the pterygo-orbital plane (pt -or) and the pterygo-palatal plane (pt-pns). the cephalometric standards for one ethnic group do not necessarily apply for other ethnic group (9). this study intended to establish the norm of the tetragon analysis for a sample of iraqi population, thus using this analysis for iraqi sample would be more accurate to describe the dento-skeletal deformity and to establish a treatment plane that respect the ethnic variation. regarding the tetragon, this study shows that upper and lower incisor are significantly proclined more than fastlich's sample (table 2), this came in agreement with prakash and shetty (8), al dagghistany (10), nahidh (11) and garma (12). the maxillary-mandibular plane angle is significantly lower than fastlich's sample and near to that of prakash and shetty (8) and garma (12). nahidh (11) found that the lower facial height in iraqi sample is smaller than caucasian sample. the trigon in this sample is rotated clockwise in comparison to fastlich's sample (7) (table 2) and that is represented by the increase in ptpns/pp angle. prakash and shetty (8) reached to same findings. many differences were found in this study than the original study thus its recommended to use the norm from this study when using tetragon analysis to get more accurate result regarding iraqi people. as a conclusion, the tetragon, in conjunction with traditional cephalometric measurements such as sna, snb, anb, and n-pog, can also indicate whether the problem with the malocclusion lies in the mandible or the maxilla or both. because the anterior planes of the tetragon represent the axial inclinations of the maxillary and mandibular central incisors and their positions in space. on the other hand, the tetragon can help the orthodontist and the maxilla-facial surgeon in his decision for planning the treatment when protraction, retraction and impaction of the premaxilla should be contemplated. table 1: descriptive statistics for the measured variables table 2: comparison between the iraqi sample and fastlicht's norm using one sample t-test max. min. s.d. mean variables 132 100 9.435 114.95 ui-pp tetragon a ng ul ar m ea su re m en ts (º ) 143 96 11.963 121.1 ui-li 118 91 7.145 103.975 li-mp 26 13 5.832 19.7 mp-pp 87 69 4.6 78.75 pt-or/pt-pns trigon 104 82 4.314 95.95 pt-pns/pp 13 1 3.427 5.475 pt-or/pp 90 78 3.341 83.75 sna others 87 75 3.378 80.65 snb 4 2 0.841 3 anb 1.327 0 0.305 0.676 n-pog-ui linear measurements (mm.) 1.05 0 0.294 0.440 n-pog-li 3.34 0.002 0.53 2.703 ui-pp 4.789 0 0.713 3.933 li-mp variables norms of fastlicht iraqi mean values mean difference t-test d.f. p-value ui-ppº 110 114.95 4.95 3.318 39 .002 ***0 ui-liº 130 121.1 8.90 4.705 39 .000 ***0 li-mpº 90 103.975 13.975 12.370 39 .000 ***0 mp-ppº 30 19.7 -10.300 -11.170 39 .000 ***0 pt-or/pt-pnsº 85 78.75 -6.250 -8.592 39 .000 ***0 pt-pns/ppº 87 95.95 8.950 13.120 39 .000 ***0 pt-or/ppº 8 5.475 -2.525 -4.66039 .000 ***0 j bagh college dentistry vol. 26(4), december 2014 cephalometric evaluation pedodontics, orthodontics and preventive dentistry166 references 1. rakosi t. an atlas and manual of cephalometric radiography. 2nd ed. london: wolfe medical publication ltd.; 1982. 2. proffit wr, fields hw, sarver dm. contemporary orthodontics. 4th ed. st. louis: mosby elsevier; 2007. 3. kuramae m, magnani mbb, nouer df, ambrosano gmb, inoue rc. analysis of tweed’s facial triangle in black brazilian youngsters with normal occlusion. braz j oral sci 2004; 3(8): 401-3. (ivsl). 4. miyajima k, mcnamara j, kimura t, murata s, iizuka t. craniofacial structure of japanese and europeanamerican adults with normal occlusions and well-balanced faces. am j orthod dentofacial orthop 1996; 110(4): 431-8. 5. naranjilla mas, rudzki-janson i. cephalometric features of filipinos with angle's class i occlusion according to the munich analysis. angle orthod 2005; 75: 63-8. (ivsl). 6. ajayi eo. cephalometric norms of nigerian children. am j orthod dentofac orthop 2005; 128(5): 653 6. 7. fastlicht j. tetragon: a visual cephalometric analysis. j clin orthod 2000; 34: 353-60. 8. prakash at, shetty ks. dental and skeletal characteristics of individuals with normal, class ii and class iii occlusions – a cephalometric evaluation using tetragon analysis. j indian orthod soc 2010; 44: 63-71. 9. cotton wn, takano ws, wong ww. the downs analysis applied to three other ethnic groups. angle orthod 1951; 21: 213-20. 10. al-daggistany ms. a study of cephalometric measurements in iraqi sample compared to downs' and steiner’s analyses. iraqi orthod j 2009; 5(1): 257. 11. nahidh m. iraqi cephalometric norms using mcnamara’s analysis. j bagh college dentistry 2010; 22(3): 123-7. 12. garma nms. comparative cephalometric study of iraqi standards with two ethnic groups according to the munich analysis. iraqi orthod j 2010; 6(1): 20-5. j bagh college dentistry vol. 29(4), december 2017 the effect of oral oral diagnosis 37 the effect of oral contraceptive pill on cortical thickness and bone mineral density of the mandibular mental and gonial regions in premenopausal females using spiral computed tomography israa k. farhood b.d.s.d.d.s (1) ahlam a. fatah b.d.s; msc. (2) abstract: background: prolonged use of low-dose estrogen ''20 micrograms or less" combined oral contraceptive pill (that have estrogen and progesterone steroid hormone) had an effect on bone turnover .bone mineral density is used in clinical medicine as an indirect indicator of osteoporosis and fracture risk. the aim of the study: the aim of this study was to investigate the effect of low dose oral contraceptive pill on the cortical thickness (in millimeter) and bone mineral density at the mandibular cortex of mental and gonial regions in hounsfield unit(hu) using spiral computed tomography. material and method: this prospective study was conducted on computed tomographic image of 100 women aged between (20-40) years .the collected sample includes patients attended for different diagnostic purposes to al-shaheed al-seder teaching general hospital of al-najaf al-ashraf from julay, 2015 to may 2016.data were grouped into two categories :group (1)control group (don't use combined oral contraceptive pill) (n=50);group(2)women taking low dose(20microgram) combined oral contraceptive pill for more than 2 years,(n=50).cortical thickness measured in millimeter and bone mineral density measured in hounsfield unit both in mental foramen and gonial angle regions .physical activity number of parity type of lactation were documented by questionnaire. result: there was a statically significant difference; in cortical thickness p=0.037 and bone mineral density p=0.007 in mental area between the two groups ;the lowest mean in group (2)and highest mean in group(1) . after adjustment for age ,number of parity, and physical activity measurement scores ,there was a significant difference p=0.001 in mean of bone mineral density and p=0.065 for cortical thickness of gonial angle between the two groups ;the highest mean in group (1) and lowest mean in group (2). conclusion: computed tomography is a good diagnostic method to measure the value of cortical thickness and bone mineral density simultaneously in mental and gonial region of the mandible in premenopausal female using low dose combined oral contraceptive pill which have small effect on bone ;depended on the woman's age and the duration of using the pill ;that did not appear until about two years of use. keywords: combined oral contraceptive pill .bone mineral density ,cortical thickness ,ct scan. (j bagh coll dentistry 2017; 29(4): 37-43) introduction: estrogen and progesterone are both female hormones generated in the ovaries and play an important role in maintaining a healthy pregnancy and carrying the fetus to term the estrogenic hormones are accountable for the growth and development of female sexual characteristics, during adolescence and pregnancy. they participate significantly to bone health and preventing bone loss.(1) estrogen with well recognized beneficial effects on bone mass and plays a critical role in skeletal homoeostasis ;it exerts effects on the function of both osteoclast and osteoblast, (1) master student, department of oral and maxillofacial radiology, college of dentistry, university of baghdad. (2) (2) assist. professor, department oral and maxillofacial radiology, college of dentistry, university of baghdad. at the cellular level, resulting in tonic inhibition of bone turnover and maintenance of the balance between bone resorpsion and bone formation(2). estrogen mediate indirect actions on bone through its effects on hormones, such as calcitonin , parathyroid hormone, cytokines and growth factors.(3). progesterone has bone-forming activity by binding to receptors on the osteoblasts ,it has the ability to increase osteoblast numbers as well as its effects to promote osteoblast maturation and differentiation .progesterone appears to play physiological role in partnership with estrogen in achieving optimal peak bone mass, the effects of progesterone and estrogen on bone are synergistic and complementary to each other .(4) j bagh college dentistry vol. 29(4), december 2017 the effect of oral oral diagnosis 38 a biological relationship of bone density to estrogen that is easily observed during menopause (5).. the relationship between estrogen deficiency and bone loss clearly suggests that hormonal contraceptive use may affect bone mineral density (bmd) .(6) combined oral contraceptives pills (cocp) are the most popular form of reversible contraception today, which is a form of estrogen and progesterone, and used for different medical indication such as: poly cystic ovary syndrome, endometriosis, amenorrhea, menstrual cramps, premenstrual syndrome, heavy menstrual periods, acne. (7) bone mineral density is a medical term normally referring to the amount of mineral matter per square centimeter of bone .bmd is used as an indirect indicator of osteoporosis and fracture risk in clinical medicine.(8) computed tomography (ct) is medical test that uses special x-ray equipment to produce multiple slices of the inside of the body and computer to join them together in cross-sectional views of the area being studied .ct is a technique that measures cortical thickness in millimeter and bmd with a calibration standard to convert hounsfield units (hu) of the ct image to bone mineral density value.(9) the mandible is the largest ,strongest and lowest bone in the face it form the lower jaw and holds the lower teeth in place .the mental foramen(mf) is one of two holes(foramina) located on the anterior surface of the mandible ,it permits passage of the mental nerve and vessel, gonial angle (ga) is located at the junction of posterior and lower border of the ramus of the mandible.(10) the current study is aimed to evaluate the effect of low dose cocp in cortical thickness and bmd at mandibular cortex of mental and gonial angle regions in millimeter (mm) and hounsfield unit (hu) using spiral computed tomography ct scan. aim of the study evaluation of the effect of low dose oral contraceptive pill (combined estrogen and progesterone hormone ),on cortical thickness and bone mineral density value at the mandibular mental foramen and gonial angle regions among premenopausal females after two years of usage using spiral computed tomographic scanning. (iraqi study) material and method prospective study of ct scan for 100 females, with age ranged from(20-40) attended the maxillofacial department at al–sheheed al-sadr general hospital in alnajaf alashraf who admitted to have spiral ct scan for different purposes from july 2015 to may 2016. the study sample were divided into the following 2 groups; group (1) 50 controlled females patient who don't take any type of contraceptive hormone. group (2) 50 female patients who taking , contraceptive pills 20 mcg ethinyl estradiol (ee) and 75mcg gestodene ,one pill each day , for at least two years . all of them asked about: number of parities, type of feeding ;breast or bottle feeding, history of abortion ,number of abortion, physical activity , type of exercise and body mass index(height and weight) .any female with traumatic fracture in the examined area, metastatic tumor to the mandibular bone, taking another mode of contraceptive hormone, any female patients with diseases or taking medication that affected bone metabolism ,any female with family history of osteoporosis ,alcohol consumption and smoking were excluded. all females asked about:1body mass index; height and weight 2physical activity (daily work ,walking pace) scores; then by computed tomography scanner( philip's brilliance ct 64-slice scan) ct scan record the cortical thickness and bone mineral density in mental and gonial angle area. mental foramen area with wical and swoope technique mental area determined by tracing two lines; 1and 2: parallel to the long axis of the mandible and tangential to the superior and inferior border of the mandibular cortex ;line 3 was performed perpendicular to the tangential lines intersecting the inferior border of the mental foramen ;the distance between two parallel line represented the mandibular cortex and the bmd is measured at the midpoint of this distance on the third line. measurement of the cortical thickness at the mental foramen region(11) as shown in fig1: fig1: diagram show method of determination of cortical thickness in mental area. j bagh college dentistry vol. 29(4), december 2017 the effect of oral oral diagnosis 39 fig:2 radiologic image showing the measurement of cortical thickness and bmd in mental foramen area. gonial angle: the angle of the mandible, is formed by the line tangent to the distal border of the ascending ramus and condyle and line tangent to the lower border of the mandible and by the line that bisectrix of the angle between the two tangent lines; the bone mineral density is measured at the middle area of the cortex with hu ,then the thickness of the cortical ga is measured in millimeter(mm) (12)as shown in fig 3: fig 3: showing the measurement of cortical thickness and bmd in gonial angle. a tangential line to the distal border of ramus b tangential line to the bottom of mandible cbisecting of the angle between a and b. fig 4:radiographic image of ct scan (coronal section). showing the measurement of cortical thickness and bmd in gonial angle area. results: for each sample in the two study groups, the cortical thickness (in millimeter)and bmd in hu were recorded at both mf and ga area the data then statistically analysis ,there was significant difference p=0.037 between mean of cortical thickness and significant difference p= 0.007 between mean of bmd between control and user cocp group in mental foramen area but there was non-significant difference p= 0.15[ns]between cortical thickness &no significant difference p= 0.16[ns] between mean of bone mineral density in gonial angle area between control and user of cocp as shown in table 1and fig5. after adjusting with other explanatory variable that effect on cortical thickness and bone mineral density such as age ,duration of combined oral contraceptive usage ,number of parity and physical activity scores; there was a significant difference p=0.065 for cortical thickness and p=0.001 for bone mineral density between control and combined oral contraceptive user in gonial angle .table2and3. j bagh college dentistry vol. 29(4), december 2017 the effect of oral oral diagnosis 40 table1: the difference in mean cortical thickness and bmd at two selected mandibular location between users and non-users of cocp controls (non-users) cases (users cocp) p (t-test) 1. cortical thickness-mental foramen 0.037 mean 4.94 4.76 2. cortical thickness-gonial angle 0.15[ns] mean 2.29 2.2 3. bone mineral density-mental foramen 0.007 mean 1620.4 1539.6 4. bone mineral density-gonial angle 0.16[ns] mean 1404.4 1362.4 fig 5: error bar chart showing the difference in cortical thickness and bmd in mental and gonial angle between the two study groups. table 2: the effect of cocp on cortical thickness of gonial angle after adjusting with other explanatory variable. un standardized partial regression coefficient p standardized coefficients (constant) 2.578 0.001 parity -0.366 0.001 -0.498 age (years) -0.252 0.001 0.297 walking pace 0.153 0.002 0.238 physical activity daily working 0.134 0.001 0.211 duration of cocp use -0.073 0.065 0.147 table3: the effect of cocp on cortical thickness of gonial angle after adjusting with other explanatory variable. un standardized partial regression coefficient p standardized coefficients (constant) 1873.4 0.001 age (years) -194 0.001 0.426 parity -102.7 0.001 -0.261 duration of cocp use -56 0.001 -0.214 walking pace 37.811 0.07 0.117 physical activity daily working 39.7 0.007 0.110 j bagh college dentistry vol. 29(4), december 2017 the effect of oral oral diagnosis 41 there is negative linear correlation and significant difference between the duration of combined oral contraceptive pill use and cortical thickness and bmd ;the highest mean as duration of use decrease and lowest mean as duration of use combined oral contraceptive increase. in each two group there is a negative linear correlation and significant difference between age with cortical thickness and bmd the highest mean of cortical thickness and bmd in 20 years old age group and lowest in 40 years old age group, also there is negative linear correlation and significant difference between the number of parity with cortical thickness and bmd ;the highest mean of cortical thickness and bmd in the low number of parity and the lowest mean of cortical thickness and bmd in the 5 and more parity group .but there is a positive linear correlation between physical activity scores and cortical thickness and bmd in each two groups. the highest mean of cortical thickness and bmd in high scores physical activity and lowest mean in low score physical activity. discusion: the sample was selected at age between 20-40 years old premenopausal ,since bone mass increases rapidly from birth, and during adolescence women will gain 40–50% of their skeletal mass(13) ,90% of total adult bone content will be accumulated by the age of 20 years (14) and the samples didn't exceed the age of 40 in order to avoid early menopause(15). all the user of cocp are of a low-dose ,20 microgram(mcg) ethinyl estradiol and 75mcg gestoden ; recommendations by the united states food and drug administration (usfda) that the dose of the estrogenic component of oral contraceptives be as low as possible ;otherwise sever risk side effect were happened such as deep venous thrombosis ,breast cancer and hypertensive(16) the cocp had small impact on bone so the longer the duration of cocp use and at least two year; the effect of the pill on cortical thickness and bmd will be significant , current study agree with scholes et al. in 2010 who show that the duration of pill usage increased , the bmd decrease in a significant negative linear correlation ; and adults who had used oral contraceptives for 24 months or longer; the lower the mean bmd. (17) progestogen negative feedback reduce the pulse frequency of gonadotropin-releasing hormone released by the hypothalamus, which lowers the release of follicular stimulating hormone (fsh) and luteinizing hormone (lh) by the anterior pituitary. diminished levels of fsh inhibit follicular development, preventing an increase in estradiol levels. progestogen negative feedback and the lack of estrogen positive feedback on lh release prevent a midcycle lh surge. suppression of follicular development and the absence of a lh surge inhibit ovulation.(18) low estrogenic effects from lower dose cocp (~20 mcg ee)suppresses the mid-cycle estrogen peak that occurs with normal ovarian function(19). estrogens have multiple actions on bone that decreases bone turnover, which increases bone density; cocp may affect all these aspects of bone development; the small-estrogenic actions of cocp would be predicted to have negative, potentially age-related, effects on bone density(20) the means of cortical thickness and bmd between two groups were significant in mental foramen area while not significant in gonial angle area only after adjusting with other explanatory variable(age, duration of cocp use ,number of parity, and physical activity measurement scores) that is because the mental index had greater sensitivity and specificity than gonial index which was least accurate due to the influence of the muscle attachment ,and continuous remodeling(21) in current study all the mean of cortical thickness in cocp use was 4.76 for mf and 2.2 for ga area respectively ;and it is in in normal range ;devlin , 2007 suggest that patients with the thinnest mandibular cortices (≤3 mm)for mf and (1.2) for ga should be referred for further osteoporosis investigation,(22) there was a statically negative linear correlation between age with cortical thickness and bmd ;as the age increase the cortical thickness and bmd decrease in the two group; aloia in 2010 showed that with aging and after menopause, fragmental calcium absorption has been reported to decline after 40 years of age. (23) it is estimated by bachmann ,1987 ;that bone mass in women is lost at a rate of 0.75% to 1% per year from age 35 onwards, and this rate increases to 2% to 3% per year at menopause.(24) there was significant negative linear correlation between number of parity and bmd in all the two study groups ;the mother adapts to meet the calcium demands of the fetus during pregnancy ; 2-3% of maternal calcium is transferred to fetus mostly in the second and third trimester when fetal bone development http://www.ncbi.nlm.nih.gov/pubmed/?term=scholes%20d%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=scholes%20d%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=scholes%20d%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=scholes%20d%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=scholes%20d%5bauth%5d j bagh college dentistry vol. 29(4), december 2017 the effect of oral oral diagnosis 42 peaks, if a pregnancy is followed by a period of breast-feeding, mother loses a further 300–400 mg calcium daily in the breast milk(25). there was significant positive linear correlation between physical activity and bmd in all the two study groups ; our present study agree with martyn et al. 2010 who stated that exercise programs that combine high-impact activity with high-magnitude resistance training appear effective in augmenting bmd in premenopausal women (26);bone is a living tissue that undergoes continuous remodeling adapts to the associated mechanical stresses, such as exercise, that are placed on it.(27) exercise may reduce the secretion of sclerostin by the osteocyte, thereby up regulating signaling and osteoblast genesis , that is, bone formation (schwab,2011) (28). our result agree with hartard et al.,1997 who show ;there is no beneficial effect of exercise on bmd was found in the group with a long exercise period and long-term intake of cocp.(29) conclusion: 1-ct is a good diagnostic method to measure the effect of cocp on cortical thickness and bmd in mf and ga simultaneously. 2age had negative linear correlation with cortical thickness and bmd in all the study sample (user &nonuser cocp) 3cortical thickness in mental and gonial area had a negative linear correlation with age in all two groups. 4-the effect of low dose cocp(20 mcg ee and 75mcg gestodene) on the density of bone ;negatively appear at least after two years of usage and as duration of use increased the loss of cortical thickness and bmd increased. 5-all the means of cortical thickness and bmd in each group of study sample with in the normal range ; but the mean of cortical thickness and bmd cocp use lower than that of control (non-user). 7-number of pregnancy (including number of abortion)and parity have negative effect on cortical thickness and bmd specially more than 5 child. 8-brest feeding (normal lactation ) have reversible negative effect on bmd that return to normal value after discontinuation of lactation. 9-physical activity daily working and walking pace cause significant increase in bmd, as physical activity scores increase the cortical thickness and bmd increase. reference: 1helen webberley , hannah nichols, estrogen: how does estrogen work? 1 april 2016. 2-riggs bl1, khosla s, melton lj ,3rd. sex steroids and the construction and conservation of the adult skeleton endocr rev. 2002 jun;23(3):279-302. review.pmid: 12050121. 3-. balasch ,sex steroids and bone: current perspective hum reprod update. 2003 may-jun;9(3):207-22. 4-vanadin seifert-klauss1 and jerilynn c. prior2,* progesterone and bone: actions promoting bone health in women,j osteoporos. 2010; 2010: 845180. published online 2010 oct 31. doi: 10.4061/2010/845180, pmcid: pmc2968416. 5eunice kennedy shriver, "menopause: overview", national institute of child health and human development. 2013-06-28. retrieved 8 march 2015. 6-castelo-branco c, vicente jj, pons f et al. bone mineral density in young, hypothalamic oligoamenorrheic women treated with oral contraceptives. j. reprod. med. 46(10), 875–879 (2001). 7-jones, rachel k. 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"contraceptive efficacy". in hatcher, robert a.; et al. contraceptive technology (19th rev. ed.). new york: ardent media. isbn 09664902-0-7. http://www.ncbi.nlm.nih.gov/pubmed/?term=martyn-st%20james%20m%5bauthor%5d&cauthor=true&cauthor_uid=20013013 http://www.ncbi.nlm.nih.gov/pubmed/?term=schwab%20p%5bauthor%5d&cauthor=true&cauthor_uid=21178629 http://www.medicalnewstoday.com/authors/dr-helen-webberley-mbchb-mrcgp-mfsrh http://www.guttmacher.org/pubs/beyond-birth-control.pdf http://www.guttmacher.org/pubs/beyond-birth-control.pdf j bagh college dentistry vol. 29(4), december 2017 the effect of oral oral diagnosis 43 19-spona j1, elstein m, feichtinger w, sullivan h, lüdicke f, müller u, düsterberg b. shorter pill-free interval in combined oral contraceptives decreases follicular development. 1996 aug;54(2):71-7. 20-vander eerden bc1, karperien m, wit jm, systemic and local regulation of the growth plate. endocr rev.2003dec;24(6):782801.reviewpmid.14671005. 21-atul anand bajoria,1,* 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different impact exercise modalities on bone mineral density in premenopausal women: a meta-analysis. j bone miner metab 28: 251-267. 27-skerry tm. the response of bone to mechanical loading and disuse: fundamental principles and influences on osteoblast/osteocyte homeostasis. archives of biochemistry and biophysics. 2008;473(2):117–123. 28-schwab p, scalapino k. exercise for bone health: rationale and prescription. current opinion in rheumatology. 2011;23(2):137–141. 29-hartard m1, bottermann p, bartenstein p, jeschke d, schwaiger m. effects on bone mineral density of lowdosed oral contraceptives compared to and combined with physical activity. 1997 feb;55(2):87-90. الفك وزاوية الذقني الثقب منطقتي في السفلى حافةال لحاء في العظم وكثافة سمك على الحمل منع حبوب تأثير الحلزوني المفراس جهاز باستخدام اليائس سن قبل النساء عند السفلي : الخالصة هرموني من المركبة و( اقل او ميكروغرام 02) األستروجين نسبة منخفضة الحمل منع لحبوب الطويل االستعمال: المقدمة كثافة لقاس السريري الطب في يستعمل مصطلح العظم معدن كثافة. للعظم الخلوي االيض على يؤثر والبروجسترون االستروجين .الكسر وخطورة العظم في السفلي للفك السفلي الحافة لحاء سمك على االستروجين نسبة منخفضة الحمل منع حبوب تأثير فحص: البحث من الهدف المفراس جهاز باستخدام الهاونسفيلد العظم كثافة قياس وحدة في العظم وكثافة بالملليميتر االسفل الفك وزاوية الذقني الثقب منطقتي .الحلزوني تتراوح امرأة 022ل الحلزوني بالمفراس مقطعية بصور موصولة االستعادية الدراسة هذه: العمل وطريقة والمواد العينات الى 0202 تموز شهر من تشخيصية اغراض لمختلف. العام التعليمي الصدر الشهيد مستشفى قصدت سنة 02-02 بين اعمارهم والمجموعة الحمل منع حبوب تتناول ال امرأة 22 من تتكون االولى المجموعة: مجموعتين الى صنفت البيانات. 0202ايار شهر العظم سمك قياس. سنتين عن تقل ال لمدة االستروجين نسبة منخفضة الحمل منع حبوب يأخذون امرأة 22 من تتكون الثانية الفك وزاوية الذقن ثقب منطقتي في السفلي لفك السفلية الحافة لحاء منطقتي في الهاونسفيلد بوحدة العظم وكثافة بالملليمتر . استطالعية ورقة طريق عن وثقت الرضاعة ونوع االطفال عدد, الفيزيائية النشاطات, السفلي المعنوية القيمة ملحوظ وفرق السفلية الحافة لحاء سمك في 232.0= المعنوية القيمة ملحوظ فرق وجد احصائيا: النتائج االولى المجموعة في االعلى هي العظم وكثافة سمك ان حيث المجموعتين بين الذقني الثقب منطقة في العظم كثافة في23220= العظم لكثافة بالنسبة23220= المعنوية القيمة حيث ملحوظ وفرق االستروجين نسبة منخفضة الحمل منع حبوب تستخدم ال التي العمر مثل العظم كثافة على تؤثر التي االخرى العوامل مع النتائج تعديل بعد ولكن العظم لسمك بالنسبة23222= المعنوية والقيمة زاوية في العظم وكثافة سمك في( العمل وسرعة اليومي العمل) الفيزيائي النشاط ودرجات الدواء استعمال فترة, االطفال عدد, الثقب منطقتي في واحد ان في العظم وكثافة سمك لقياس جيدة تشخيصية طريقة هو الحلزوني لمفراس ا: الستنتاجات ا. السفلي الفك العظم على خفيفا تأثر تؤثر التي االستروجين نسبة منخفضة الحمل منع حبوب يستخدمن اللواتي للنساء السفلي الفك وزاوية الذقني .االعراض لظهور سنتين عن تقل ال طويلة ولفترة العمر على معتمدا riadh f.doc j bagh college dentistry vol. 27(3), september 2015 in-vitro evaluation pedodontics, orthodontics and preventive dentistry159 in-vitro evaluation of load-deflection characteristics and force levels of nickel titanium orthodontic archwires riyadh abdu al-hamza ruwiaee, b.d.s. (1) akram faisal al-huwaizi, b.d.s., m.sc., ph.d. (2) abstract background: nickel-titanium (niti) archwires have become increasingly popular because of their ability to release constant light forces, which are especially useful during initial alignment and leveling phase. the aim of the present study was to investigate and compare the load–deflection characteristics of four commercially available niti archwires. materials and methods: 200 niti 0.014, 0.016, 0.018, 0.016x0.022 and 0.019x0.025-inch nickel–titanium archwires from four different manufacturers (3m, ortho technology, jiscop and astar) were tested. the load-deflection properties of these archwires were evaluated by a full arch bending test in both palatal and gingival directions at 37°c temperature using a universal material testing machine. forces generated at maximum loading of 2mm and at unloading of 1.5mm were measured. results: all the tested niti wires showed an increase in loading and unloading force with increased wire dimension. generally, 3m gave the most flexible round wires and relatively stiff rectangular wires; with linear load deflection curves. ortho technology wires were flexible. jiscop gave the stiffest round wires and the most flexible rectangular wires. astar wires were stiff which gave the highest force levels during unloading. conclusion: force levels vary greatly from brand to brand and so niti wire brands must be selected with consideration to their load-deflection characteristics and mechanical properties. key words: load-deflection; force level; nickel titanium archwires. (j bagh coll dentistry 2015; 27(3):159-164). introduction dental arch alignment and leveling is the initial stage of orthodontic treatment. satisfactorycompletion of this first stage is essential if esthetic; function and stability are to be achieved (1). a well-planned orthodontic treatment starts with very flexibleand superelastic wires fully engaged into the bracket on each arch. usually, the ideal archwire for that initial first stag generates a light and continuous force over a long period of time (2). super-elastic nickel-titanium (ni-ti) alloy wires with low stiffness and high superelasticity aregenerally used in the leveling and alignmentstages of orthodontic treatment for efficient toothmovement and a desirable biological response (3). these austenitic-active niti alloys are predominantly in theaustenitic phase at room temperature. nickel-titanium (niti) alloys have been widely usedin orthodontics because of their favorable mechanicalproperties, a remarkable feature of which is their super-elasticity (4). superelasticity is the transformation from austenitic to martensitic that occurs by stress application within a temperature range and is manifested by a flat or nearly flat plateau in a force-deflection curve (5). (1)master student. department of orthodontics. college of dentistry, university of baghdad. (2)professor. department of orthodontics. college of dentistry, university of baghdad. the transition between the two phases is termedmartensitic transformation, and it is responsible for thememory effect. this transformation is the result of changes in the crystal lattice of the material. shape-memory property is the plastic deformationof niti wires from the martensite phase to an austenitecrystal structure (6). most of the information about the behavior of these wires is based on mechanical laboratory testing without simulating the many variables encountered in clinical situations (7). the most appropriate wire tests those that reproduce conditions encountered clinically, with the wire constrained as part of a fixed appliance (8). variations in model design have been shown to affect unloading deflection plots (9). recent studies reveal all commercial wires do not necessarily behave in the same manner. minor differences in the production process contribute to the variation in the behavior of these wires (10). this investigation details a comparison of forces achieved in different commercial niti superelastic wires in a deflection test of activation and deactivation that attempts to approximate clinical conditions (11). full arch (palatal and gingival deflection) tests for four different brands of ni-ti alloy wires are made under the same testing conditions to clarify their load-deflection properties. material and methods five gauges of niti wires (0.014, 0.016, 0.018, 0.016x0.022 and 0.019x0.025 inch) were j bagh college dentistry vol. 27(3), september 2015 in-vitro evaluation pedodontics, orthodontics and preventive dentistry160 tested to compare their mechanical properties. the sample comprised of wires from four brands 3m unitek (monrovia, usa), ortho technology (tampa, florida, usa), jiscop (dangieahg-dong, gunpo-si, kyeanggi-do, korea) and astar (shanghai, china). preformed archwire were tested with phantom head jaw (shanghai, china) in palatal and gingival deflectionswith greater stability and positional accuracy.the teeth of a plastic phantom head jaw were fitted with roth prescription 0.022×0.028 inch slot passive self-ligating brackets and buccal tubes(ortho technology, tampa, florida, usa).secure attachment was achieved forboth by bonding the base of them to the crown. accurate slot alignment was achieved by using a plain 0.021x0.025 stainless steel arch wire as a former while the bonding was light cured the load site simulated a misaligned upper right canine with 15mm between the midpoints of the brackets. this interbracket distance was derived from typical tooth dimensions (8).the bending test was carried out with universal material tester by deflecting the wire at the midpoint.each bending test was done 10 times, with a new piece of wire for each repetition.all tests were carried out in a water bath at temperature 37°c ±0.5°c with digital thermometer control (fig.1). load at maximum deflection of 2mm was registered as a measure of flexibility.load during unloading phase at 1.5mm deflection was registered as a measure of elasticity (fig.2). (12). figure 1: a test in progress on the phantom head jaw in a. palatal b. gingival deflection test. figure 2. typical x-y plot of load deflection curve for niti wire at 2 mm load-deflection test whereas udp, unloading deflection point at 1.5mm. results most, but not all, load-deflection graphs of both palatal and gingival tested niti wires confirmed features of superelasticity, with plateau regions varying in gradient and load value depending on the testing direction, wire dimension and wire brands (fig.3). after reach the maximum force at 2mm deflection, the unloading plot for all bending tests typically dropped very rapidly followed by a plateau region during which a relatively constant force was produced. in this superelastic range, the load curves for loading and unloading were consistent with the definition of hysteresis (13). j bagh college dentistry vol. 27(3), september 2015 in-vitro evaluation pedodontics, orthodontics and preventive dentistry161 the results of the anova and lsd show that the forces generated by the four brands of the five niti wire gauges at loading and unloading showed highly significant difference at the p<0.001 level. figures 4 and 5 showed the force at maximum loading of 2mm and unloading at 1.5 mm deflection using both palatal and gingival deflection tests for the five niti wires gauges from four brands. from these figures the following can be noted: 1. all the tested niti wires showed an increase in loading and unloading force levels with increase of wire dimension. the differences of force level were small in round cross section wires, but were noticeably large in rectangular cross section wires 2. in general, for all round (0.014, 0.016 and 0.018 inch) wires, both astar and jiscop displayed high loading and unloading forces while 3m gave the lowest forces. whereas for both rectangular (0.016x0.22 and 0.019x0.025-inch) wires, astar and 3m displayed high loading and unloading forces while jiscop gave the lowest forces. ortho technology wire’s force levels were intermediate mostly in both tests. discussion the factors that determine the mechanical properties of ni-ti alloy wires include composition, heat treatment, and degree of working. concerning the composition ratio of nickel and titanium, most manufacturers are cautious about releasing such information, as it is regarded as a trade secret (14). this study agreed with nakano et al. (15) who observed great variations in force values with different niti wires of the same diameter, indicating that the wires are intrinsically different and therefore should be differentiated according to their characteristics. loading curve represents the force required to insert the wire in the bracket on the crowded teeth, therefore, the force is usually measured at the last deflection of loading curve (maximum force level). the wires with highest maximum force were stiffer, while the wires with lowest force were flexible (16). the differences of forces may be due to that the martensitic transformation (sim) occurred earlier for the lowest force wires than for the highest force wires (14). for round wires, 3m ni-ti wires exerted the least maximum loading force which agrees with the findings of gatto et al. (10) who also found their load-deflection curves to be narrow and steep at 2mm deflection but were wider with larger plateau at 4mm deflection. this means that at 2mm these wires did not express their superelasticity as greater deformation generate the martensitic transformation induced by this stress (sim). on the other hand, 3m 0.019x0.025 inch wires showed the highest maximum loading force which may be due to that some austenitic niti wires exhibit stiffness higher than that of tma wires, if the deformation does not reach that of the proportional limit (17). the unloading curve represents the force delivered to teeth during treatment and usually is measured in several deflection points. however, the different brands of ni-ti alloy wires tested varied widely in the force levels they exerted. the level of susceptibility of the periodontium is one of the essential factors for determining the effective and safe value of the force which should not be exceeded when applied to a single tooth (18). an ideal archwire should be able to deliver differential forces to the arch segments. the force should range from about 70g to 80g in the incisor area and gradually increase toward the posterior segments, up to 300g. (19) an optimal performance of austenitic niti wires will be obtained in cases of severe dental crowding, when an accentuated deflection due to the irregular interbracket span will generate sim in a localized area of the arch, usually the lower incisor area. mild crowding does not necessarily require the use of superelastic wires, and a small diameter alloy such as 3m wire will generally perform as well (20). our study agreed with the study of sarul et al. (18) during testing the mechanical properties of the niti wires of various diameters, they found that some round section wires release forces which fall within the range of optimal forces. that makes them more clinically useful. some rectangular wires as with 0.019x0.025 inch jiscop wires, the loading force were relatively high but, after 1.5mm unloading the force were the lowest in range of 884g to 643g for both tests. this could be explained by garrec and jordan (21) who stated that the value of stiffness appears to vary with wire size but depends on the ratio of volume of martensitic transformation i.e. a large-size rectangular wire does not produce necessarily high forces during unloading. so, in this study, the archwires can be classified according to their flexibility (from highest to lowest) into 3m, ortho technology, astar and jiscop wires for both round and rectangular wires. j bagh college dentistry vol. 27(3), september 2015 in-vitro evaluation pedodontics, orthodontics and preventive dentistry162 as conclusions; 1. all the tested niti wires showed an increase in loading and unloading force with increase of wire dimension. 2. in general, for round wires, astar and jiscop displayed high loading and unloading forces while 3m gave the lowest forces. whereas for rectangular wires, astar and 3m displayed high loading and unloading forces while jiscop gave the lowest forces. ortho technology wire’s force levels were intermediate. 3. wires can be classified (from highest to lowest) according to their flexibility as 3m, ortho technology, astar and jiscop. palatal deflection tests gingival deflection tests 0. 01 4 in ch 0. 01 6 in ch 0. 01 8 in ch 0. 01 6x 0. 02 2 in ch j bagh college dentistry vol. 27(3), september 2015 in-vitro evaluation pedodontics, orthodontics and preventive dentistry163 0. 01 9x 0. 02 5 in ch figure 3: load deflection curves for the 0.014, 0.016, 0.018, 0.016x0.022 and 0.019x0.025 inch wires from four brands using bothpalatal and gingival deflections. figure 4: maximumloading forces at 2mm deflection for the five niti wires gauges from four brands using both palatal and gingival deflection tests. figure 5: unloading forces at 1.5mm deflection for the five niti wires gauges from four brands using both palatal and gingival deflection tests. references 1. khier se, brantley wa, fournelle ra. bending properties of superelastic and nonsuperelastic nickeltitanium orthodontic wires. am j orthod dentofacial orthop 1991; 99: 3108. 2. miura f, mogi m, ohura y, hamanaka h. the superelastic property of the japanese niti alloy wire for use in orthodontics. am j orthod dentofacial orthop 1986; 90: 1-10. 3. andreasen gf, hileman tb. an evaluation of 55cobalt substituted wire for orthodontics. j am dent assoc 1971; 82: 1373-5. 4. brantley wa. orthodontic wires. in: brantley wa, eliades t (eds.) orthodontic materials: scientific and clinical aspects. stuttgard: thieme; 2001. p. 91-9. 5. segner d, ibe d. properties of superelastic wires and their relevance to orthodontic treatment. eur j orthod 1995; 17: 395-402. 6. meling tr, ødegaard j. the effect of short term temperature changes on superelastic nickel-titanium arch wires activated in orthodontic bending. am j orthod dentofacial orthop 2001; 119(3): 263-73. 7. mullins ws, bagby md, norman tl. mechanical behavior of theromoresponsive orthodontic arch wires. dent mater 1996; 12: 308-14. 8. mallory dc, english jd, powers jm, brantley wa, bussa hi. force-deflection comparison of superelastic nickel-titanium archwires. am j orthod dentofacial orthop 2004; 126(1): 110-2 9. elayyan f, silikas n, bearn d. mechanical properties of coated superelastic archwires in conventional and self-ligating orthodontic brackets. am j orthod dentofacial orthop 2010; 137: 213-7. palatal gingival palatal gingival j bagh college dentistry vol. 27(3), september 2015 in-vitro evaluation pedodontics, orthodontics and preventive dentistry164 10. gatto e, mateares g, di bella g, nucera r, cordasco g. load deflection characteristics of super and thermal ni-ti wires. eur j orthod 2011; 10: 1-9 11. lombardo l, toni g; stefanoni f, mollica f, guarnerie m, siciliani g. the effect of temperature on the mechanical behavior of nickel-titanium orthodontic initial archwires. angle orthod 2012; 83(2): 298-305 12. wilkinson pd, dysart ps, hood jaa, herbison g. load-deflection characteristics of superelastic nickeltitanium orthodontic wires. am j orthod dentofacial orthop 2002; 121: 483-95. 13. bednar jr, grueneman gw, sandrik jl. a comparative study of frictional forces between orthodontic brackets and arch wires. am j orthod dentofacial orthop 1991; 100: 513-22 14. liaw yc, su yy, lai yl, lee sy. stiffness and frictional resistance of a superelastic nickel-titanium orthodontic wire with low-stress hysteresis. am j orthod dentofacial orthop 2007; 131(5): 578.e12-8. 15. nakano h, satoh k, norris r, jin t, kamegai t, ishikawa f, katsura h. mechanical properties of several nickel-titanium alloy wires in three-point bending tests. am j orthod dentofacial orthop 1999; 115(4): 390-8. 16. schemann-miguel f, cotrim-ferreira f, streva am, chaves avoa. comparative analysis of load/deflection ratios of conventional and heatactivated rectangular niti wires. dental press j orthod 2012; 17(3): 23.e1-6. 17. proffit wr, fields hm, sarver dm. contemporary orthodontics. 5th ed. st. louis: cv mosby 2013. 18. sarul m, kawala b, antoszewska j.comparison of elastic properties of nickel-titanium orthodontic archwires. adv clin exp med 2013; 22(2): 253-60 19. tonner ri, waters ne. the characteristics of superelastic ni-ti wires in 3-point bending. 1. the effect of temperature. eur j orthod 1994; 16(5): 409-19 20. santoro m, olivier fn, thomas jc. pseudoelasticity and thermoelasticity of nickel titanium alloys: a clinically oriented review. part i: temperature transitional range. am j orthod dentofacial orthop 2001; 119(6): 587-93 21. garrec p, jordan l. stiffness in bending of a superelastic ni-ti orthodontic wire as a function of cross sectional dimension. angle orthod 2004; 74(5): 691-6. omar final.doc j bagh college dentistry vol. 26(2), june 2014 the benefit of oral and maxillofacial surgery and periodontics 122 the benefit of ramfjord teeth to represent the full-mouth clinical attachment level in epidemiological study omar husham ali, b.d.s., m.sc. (1) hadeel mazin, b.d.s., m.sc. (1) abstract background: since the periodontal disease index of ramfjord (ramfjord index) can potentially shorten the examination time by almost half, many studies evaluated ramfjord teeth in predicting full-mouth periodontal status of an adult population. the aim of this study was to evaluate the benefit of ramfjord teeth in predicting the fullmouth clinical attachment level of an adult population in patients attending the college of dentistrybaghdad university. materials and methods: the study participants were 100 patients with age range from 30-60 years old which represent group zero. the patients were divided into three main groups according to the age of the patients. group i and group ii each of them composed of 30 patients while group iii composed of 40 patients. in the first time clinical attachment level (cal) was measured from the full mouth (fm) and then from the ramfjord teeth (rt) (teeth number: 16, 21, 24, 36, 41, 44) in all groups. clinical attachment level (cal) was measured in millimeters using periodontal probe. results: the difference in the mean clinical attachment level measured from the full mouth (fm) and ramfjord teeth (rt) by using paired t test was non significant in all the groups. also in all groups the correlation coefficient as well as beta coefficient was high. conclusion: the high agreement between ramfjord teeth and full mouth cal confirm the epidemiological validity of ramfjord teeth to represent the full mouth. key words: ramfjord teeth, clinical attachment level, full-mouth examination. (j bagh coll dentistry 2014; 26(2): 122124). الخالصة .لثة لكامل الفم في السكان البالغینمفورد المراض اللثة یمكن ان یقلل وقت الفحص الى النصف تقریبا، لذا الكثیر من الدراسات قیمت اسنان رامفورد في توقع الحالة الصحیة لمؤشر را .جامعة بغداد -الغیین من المرضى الذین یراجعون كلیة طب االسنانھدف ھذه الدراسة كان لتقییم اسنان رامفورد في توقع مستوى االنسجة الرابطة لكامل الفم لدى السكان الب . تم تقسیم المشاركین في ھذه الدراسة الى ثالث مجموعات رئیسیة وفقا للعمر. سنة ویمثلون مجموعة الصفر 60-30المشاركین في ھذه الدراسة كانوا مائة مریض، تتراوح اعمارھم من .مشارك 40مشارك بینما المجموعة الرابعة تتكون من 30منھما من المجموعة االولى والثانیة تتكون كل في كل ) 16،21،24،36،41،44: اسنان رامفورد( (rf)ومن ثم قیاس مستوى االنسجة الرابطة السنان رامفورد (fm)تم اوال قیاس مستوى االنسجة الرابطة لجمیع االسنان في الفم .طة باستخدام مسبار اللثةتم قیاس مستوى االنسجة الراب. المجموعات كان غیر مھم في كل المجموعات، قیاسات معامل t باختبار (rf)ومستوى االنسجة الرابطة السنان رامفورد (fm)الفرق بین معدل مستوى االنسجة الرابطة المقاس لكامل الفم .االرتباط ومعامل بیتا في كل المجموعات كانت عالیة ولكامل الفم یؤكد صحة استخدام اسنان رامفورد لتمثیل كامل الفم في الدراسات الوبائیة وى االنسجة الرابطة السنان رامفوردالموافقة العالیة بین مست introduction most survey methods use full-mouth assessment of periodontal diseases, which involves the examination of 4 sites on all present teeth. data from full-mouth examination are the gold standard for accurate assessment of periodontal disease. however, because of the restraints in time, logistic, and cost of full-mouth assessment, this clinical assessment of periodontal diseases is impractical in epidemiological surveys involving large population samples (1). therefore, the programs to examine part of teeth are proposed (2). since the ramfjord index can potentially shorten the examination time by almost half, mumghamba et al evaluated ramfjord teeth in predicting full-mouth periodontal status of an adult population (3). partial recording of indices of periodontitis have long been used in clinical and epidemiological studies to predict full-mouth situation (4). (1)assistant lecturer, department of periodontics, college of dentistry, university of baghdad ramfjord index had a strong correlation with the full-mouth index in recording plaque, gingivitis, and other periodontal indicators like the probing pocket depth but due to the site-specificity of periodontal diseases, a part of the teeth does not fully reflect the status of full-mouth teeth (5). so that different index teeth be selected depending on the purpose of survey so as to not only assesses both the incidence and severity of the disease correctly, but also improve the sensitivity and reduce the bias (6). materials and methods the patients participated in this study were referred to the department of periodontics in college of dentistry baghdad university. the patients include 100 male which represented by group (0). all the patients were suffered from chronic periodontitis which affect people mostly after the age of 30; the samples were divided into three main groups according to the age of the patients in which group (i) include 30 patients with an age range of (30-40) years, group (ii) j bagh college dentistry vol. 26(2), june 2014 the benefit of oral and maxillofacial surgery and periodontics 123 include 30 patients with an age of (>40-50) years while group (iii) include 40 patients with an age more than 50 years. clinical attachment level (cal) was measured in millimeters using william periodontal probe with williams's markings from the cementoenamel junction to the bottom of the pocket/sulcus. the measurements were made at four surfaces of each tooth. the distance was measured indirectly by subtracting the distance from the gingival margin to the cemento-enamel junction from probing pocket depth. in some cases when there was gingival recession, loss attachment was measured by adding the distance from the gingival margin to the cemento-enamel junction to the probing pocket depth. the level of the cemento-enamel junction could be determined by feeling it with probe. in some situation were the cemento-enamel junction was totally obliterated by: 1. full crown coverage. 2. distoocclusal, mesio-occlusal or mod fillings were extended below cementoenamel junction. 3. badly carious tooth, were extending mesially or distally below the cementoenamel junction. 4. heavy calculus covers the teeth. in these situations the tooth was excluded. if the patient had a ramfjord tooth/teeth missing, he was excluded from the study. in the first time clinical attachment level (cal) was measured from the full mouth (fm) and then from the ramfjord teeth (rt) in all groups. the mean cal per tooth was calculated by summing the measurements per tooth and dividing by the number of measurements. mean cal for full mouth was calculated by summing the mean cal per tooth and dividing by the number of the teeth. while the mean cal for ramfjord teeth was calculated by summing the mean cal per tooth for the ramfjord teeth (teeth number: 16, 21, 24, 36, 41, 44) and dividing them by the number of the ramfjord teeth, if the ramfjord tooth was missing the case was ignored. the statistical analyses used in this study were a paired t-test to compare the difference in the mean cal measured from the full mouth (fm) versus ramfjord teeth (rt). in addition to that pearson correlation coefficients between the mean cal calculated from the full mouth measurement and from the ramfjord teeth were conducted and then a linear regression analysis (β coefficient) with the full mouth mean cal as the outcome variable and the ramfjord teeth mean cal as independent variable were conducted . results descriptive statistics which include mean and standard deviation of cal for each group were shown in table (1). the difference in the mean of cal measured from the full mouth (fm) and ramfjord teeth (rt) by using paired t-test were non significant in all the groups as shown in table (2) the p>0.05 non significant. the correlation between the mean cal calculated from the full mouth and ramfjord teeth was 0.75 in the 1st age group and was 0.92 in the 2nd age group, while it was 0.86 in the 3rd age group, in the all previous groups the correlation coefficient were strong (+)ve, as shown in the table (3). we then conducted a linear regression analysis with the full mouth mean cal as the outcome variable and the ramfjord teeth mean cal as the independents variable in each group, the β coefficient for the mean cal measured by ramfjord teeth to predict the full mouth was ranged between 0.70 and 1.06, the result were positive for the all groups which mean it is a significant result, as shown in table (4). table 1: descriptive statistics of cal for each group descriptive statistics group 0 no=100 group i group ii group iii 30-40 40-50 >50 f.m r.t f.m r.t f.m r.t f.m r.t mean 2.88 2.82 2.54 2.48 2.62 2.54 3.34 3.28 +sd 0.076 0.079 0.11 0.099 0.099 0.11 0.126 0.133 table 2: t-test and significant difference of mean cal for each group groups t-test p-value sig group 0 1.81 0.073 ns group i 0.816 0.42 ns group ii 1.789 0.084 ns group iii 0.93 0.355 ns j bagh college dentistry vol. 26(2), june 2014 the benefit of oral and maxillofacial surgery and periodontics 124 table 3: correlation coefficient between f.m and r.t of mean cal for each group groups r group 0 0.888 group i 0.755 group ii 0.925 group iii 0.865 table 4: linear regression of f.m and r.t for mean cal at each group groups slope b linear regression equation group 0 0.923 y=0.154+0.924x group i 0.701 y=0.699+0.701x group ii 1.06 y=-0.256+1.07x group iii 0.916 y=0.217+0.916x discussion the study based on cal measurement in patients have chronic periodontitis of different age groups, the results show non significant differences between ramfjord teeth and full mouth at different age groups using paired ttest. the other results show strong (+ve) correlation between ramfjord teeth and full mouth at different age groups. the beta coefficient which was used to assess prediction of the full-mouth mean cal by ramfjord teeth mean cal was high. the high agreement between ramfjord teeth and full mouth mean cal proves the epidemiological validity of ramfjord teeth to represent the full mouth. this was disagree with fleiss et al, who found that the ramfjord teeth are inadequate alternatives of the rest of the mouth for epidemiologic studies of periodontitis (7), so that the assessment of ramfjord teeth was not as suitable for evaluation of either disease extent or prevalence (2). but this study was in agreement with mumghamba et al, silness and røynstrand, and najah et al (3,5,8). they concluded that there is high agreement between ramfjord teeth and full mouth. partial-mouth examinations with appropriate adjustment of ramfjord index teeth data may be useful for assessing periodontal disease progression in longitudinal population studies of human periodontitis (9). so these results support the use of ramfjord teeth procedure to conserve time, limit cost and reduce patient and examiner fatigue, while providing maximal clinical information (2). references 1. kingman a, albandar jm. methodological aspects of epidemiological studies of periodontal diseases. periodontol 2000; 29:11-30. 2. dowsett sa, eckert gj, kowolik mj. the applicability of half mouth examination to periodontal disease assessment in untreated adult populations. j periodontology 2002; 73(9): 975-81. 3. mumghamba eg, pitiphat w, matee mi, simon e, merchant at. the use fullness of using ramfjord teeth in predicting periodontal status of a tanzanian adult population. j clin peiodontol 2004; 31:16-8. 4. hunt rj. the efficiency of half mouth examination in estimating the prevalence of periodontal disease. journal of dental research 1987; 66: 1044-8. 5. silness j, røynstrand t. partial mouth recording of plaque, gingivitis and probing depth in adolescents. j clin periodontol 1988; 15:189-92. 6. zhang j. applicability of community periodontal index teeth and random half-mouth examination to gingival bleeding assessment in untreated adult population in beijing. chin med sci j 2012; 27: 41-5. 7. fleiss jl, park mh, chilton nw, alman je, feldman rs, chauncey hh. representativeness of the ramfjord teeth for epidemiologic studies of gingivitis and periodontitis. commun dent and oral epidemiol 1987; 15(4): 221-4. 8. najah a, seham s, fadhil r. the usefulness of ramfjord teeth to represent the full-mouth pocket depth in epidemiological study. j baghdad coll dent 2010; 22(2): 272-5. 9. rams te, oler j, listgarten ma, slots j. utility of ramfjord index teeth to assess periodontal disease progression in longitudinal studies. j clinical periodontology 1993; 20(2):147-50. basma f.doc j bagh college dentistry vol. 27(3), september 2015 salivary tumor pedodontics, orthodontics and preventive dentistry124 salivary tumor marker ca15-3 and selected elements in relation to oral health status among a group of breast cancer women basma abdul bari azeez, b.d.s. (1) ahlam t. mohammed, b.d.s., m.sc. (2) abstract background: breast cancer is the commonest type of malignancy worldwide and in iraq. it is a serious disease that affects the general health and cause systemic changes that affect the physical and chemical properties of saliva leading to adverse effects on oral health. this study was conducted to assess the tumor marker ca15-3 and selected elements in saliva and their relation to oral health status among breast cancer patients compared to control group. materials and methods: the total sample consisted of 60 women aged 35-45 years. 30 women were newly diagnosed with breast cancer before taking any treatment and surgery (study group) and 30 women without clinical signs and symptoms of breast cancer as a control group. dental caries was recorded using dmfs index of who1987, and periodontal parameters which include plaque index (pli), calculus index (cali), gingival index (gi), and ramfjod index for the loss of periodontal attachment (cal) were recorded. stimulated salivary samples were collected and salivary flow rate, salivary ca15-3 and selected elements were determined. results: caries experience (dmfs) was higher among the study group compared with the control group but the difference was statistically not significant. the mean values of plaque index, calculus index, gingival index and loss of attachment were higher among the study group than the control group with a highly significant difference(p<0.01). the concentrations of the tumor marker ca15-3 in saliva of breast cancer patients were highly significantly higher than that of the controls. the salivary flow rate was observed to be lower among study group compared to control group with a highly significant difference (p<0.01). higher concentrations of salivary phosphorus, copper and total proteins were recorded among study group compared to control with statistically highly significant differences concerning phosphorus and copper. while salivary calcium and zinc were lower among study group compared to control group with statistically highly significant difference concerning zinc conclusions: this study showed that the breast cancer patients had poor oral hygiene and higher rates of periodontal diseases and dental caries. in addition, the results of this study could support the concept that salivary concentrations of ca15–3 might serve to be used in the detection of breast cancer and/or the post-operative followup of patients under treatment for carcinoma of the breast. key words: breast cancer, oral health, ca15-3. (j bagh coll dentistry 2015; 27(3):124-129). introduction breast cancer is the most common cancer affecting women in the world today that it has become a major health problem in the developed world. it is the leading cause of cancer related death for women aged between 35 and 55 years worldwide (1,2). most commonly originate from the inner lining of milkducts or the lobules that supply the ducts with milk. according to the latest iraqi cancer registry, breast cancer account for approximately one third of the registered female cancers in iraq, indicated that the breast cancer is the leading cancer site among females (3,4). as breast cancer affects general health, it has also an effect on oral health, and the oral diseases were found to have an effect and role in initiating breast cancer as some studies found that dental caries and periodontal diseases have a role in carcinogenesis and may predict cancer risk (5-7). human saliva is an important biological fluid that plays a critical role in the maintenance of oral and dental health (8). (1) m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assist. professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. saliva through its physical properties like flow rate, and chemical composition that include inorganic and organic components affects oral health (9). salivary diagnostics have been developed to monitor oral diseases such as periodontal diseases and dental caries (10). saliva can also be used as a diagnostic fluid in medicine and it has long been recognized as a mirror of the body's health, therefore a large number of salivary biomarkers for different diseases including breast cancer was detected (11,12). carcinoma antigen ca15-3 (muc1) is a glycoprotein which is found on the surface of cancer cells and sheds into the blood stream, and this tumor marker was found in the saliva of women diagnosed with breast cancer (13). as there is no previous study that investigate the tumor marker ca15-3 and the salivary elements (ca, p, zn, cu, total proteins) and their relation to oral health status among breast cancer patients so this study was conducted. materials and methods the studied sample consisted of 30adult women with breast cancer aged 35-45 years. the age was recorded according to the last birthday j bagh college dentistry vol. 27(3), september 2015 salivary tumor pedodontics, orthodontics and preventive dentistry125 (who, 1997) (14). they were patients attending the breast clinic in al-kadhemyia teaching hospital. all the patients were examined clinically and also by mammography, ultrasonography and biopsy taking (fine needle aspiration, excisional biopsy), and a physician approved the breast tumor. the sample include patients with stages ii and iii before taking any treatment .while the control group composed of 30 women didn’t have any clinical signs of breast cancer matching in age with study group. both study and control groups were married, having children, with history of breast feeding, non smokers, shouldn’t take any medication or nutritional supplements and with no history of medical problem. caries experience was recorded using plane mouth mirror and dental explorer according todecayed, missing and filled surfaces index (dmfs)(15).oral hygiene was assessed by using plaque index(pli) of silness and loe (16) and calculus index (cali) of ramfjord (17), gingival inflammationwas assessed by using the gingival index (gi) by loe and silness (18) and measurement for the loss of periodontal attachment (cal) wasmade by using calibrated periodontal probe (william's probe) following the criteria of ramfjord (17). the collection of stimulated saliva from subjects was performed following instruction cited by tenovuo and largerlof (19). saliva was collected between 9.00 and 11.30 am after the examination of dental plaqueby asking each individual to chew arabic gums of uniform size for one minute then to remove all saliva by expectoration and this was continued for 10 minutes, then the salivary volume wasestimated by measuring cylinder and the rate ofsecretion was expressed as milliliter per minute (ml/min). each salivary sample was centrifuged at 4000 r.p.m for 10 minutes then the clear supernatants were stored at (-20°c) in a deep freeze till the time of biochemical analysis. chemical analyses of the elements ca, cu and zn ions were determined using air-acetylene atomic absorption spectrophotometer (buck scientific, 210 vgp, usa) according to instrumental manufacturer’s specification(20),while inorganic phosphorous and total proteins were determined colorimetrically by using readymade kits (biomaghreb, tunisia) for phosphorous and (syrbio) for total proteins. ca15-3 was determined using (cusabio, csb-e04772h) elisa kit and the assay determined by elisa method. analysis of data was carried out using spss (version19). statistical tests used were student's ttest and pearson’s correlation coefficient. the confidence limit was accepted at 95%, p< 0.05 was regarded as statistically significant and p< 0.01 was regarded as highly significant. results clinical examination showed that all subjects in both groups were affected by dental caries. caries experience (mean and standard deviation) among breast cancer and control groups are shown in table (1). results revealed that caries experience represented by dmfs and decayed surfaces was higher among breast cancer group compared to control group, but the difference was statistically not significant (p>0.05). results also showed higher mean values of plaque index, calculus index, gingival index and clinical attachment loss among the study group than the control group with statistically highly significant difference (table 2). the concentrations of the tumor marker ca153 in saliva of breast cancer patients were highly significantly higher than that of the controlsas shown in table (3). the correlations between salivary ca15-3 and dental caries and periodontal diseases were weak and statistically not significant as shown in table (4). the salivary flow rate was lower among breast cancer group than control group with highly significant difference between them.the concentrations of salivary phosphorus, copper and total proteins were higher among study group compared to control with statistically highly significant differences concerning phosphorus and copper, while salivary calcium and zinc were lower among study group compared to control group with statistically highly significant difference concerning zinc, these results are shown in table (5). table (6) illustrates the pearson’s correlation coefficientbetweensalivary variables and caries experience.analysis among breast cancer group revealed weak negative not significant correlation between salivary flow rate and ds, while the relation was weak positive with dmfs. in control group the correlation was weak negative not significant for dmfs but was significant for ds. also the results showed that all the correlations between the caries experience and salivary constituents in the study and control groups were weak and not significant except the correlation with total proteins in the control group was significant positive. j bagh college dentistry vol. 27(3), september 2015 salivary tumor pedodontics, orthodontics and preventive dentistry126 table 1: dental caries experience (mean± s.d.) among study and control groups table 2: oral hygiene and periodontal indices among study and control groups variable study group control group statistical test mean ± sd mean ± sd t-test p-value pi 1.72 0.21 1.24 0.17 9.75 0.00** cali 0.84 0.30 0.52 0.17 5.21 0.00** gi 1.27 0.19 0.89 0.20 7.88 0.00** cal 1.37 0.67 0.30 0.21 8.24 0.00** table 3: salivary ca15-3 (u/ml) among study and control groups table 4: correlation coefficients of salivary ca15-3 with caries experience, gingival index and loss of attachment among study and control groups table 5: salivary variables among study and control groups table 6: correlation coefficients of salivary variableswith dental caries variable study group control group ds dmfs ds dmfs r p r p r p r p salivary flow rate -0.11 0.56 0.15 0.42 -0.36 0.05* -0.31 0.1 ca -0.08 0.69 -0.02 0.91 -0.06 0.07 -0.06 0.75 p -0.17 0.37 -0.26 0.16 0.06 0.76 -0.02 0.92 zn -0.1 0.59 0.35 0.06 0.23 0.22 0.33 0.08 cu -0.24 0.19 -0.13 0.48 0.13 0.49 0.09 0.64 tp 0.14 0.45 0.23 0.21 0.39 0.03* 0.41 0.03* discussion breast cancer affects general health like other cancers in any part of the body (21), as well as it affects oral health (5,22). saliva as a diagnostic fluid offers some distinct advantages over serum in diagnosing diseases (23,24). from a logistical perspective, the collection of saliva is safe, noninvasive, and simple, and it may be collected repeatedly without variable study group control group statistical test mean ± sd mean ± sd t-test p-value ds 8.80 8.27 6.57 4.65 1.29 0.20 dmfs 34.03 14.12 28.37 12.84 1.62 0.11 variable study group control group statistical test mean ±sd mean ±sd t-value p-value ca15-3 8.84 1.70 3.37 1.05 14.99 0.00** oral variables study group control group ca15-3 ca15-3 r p sig. r p sig. caries experience ds 0.19 0.32 ns. -0.19 0.32 ns. dmfs -0.05 0.79 ns. -0.33 0.08 ns. gi 0.01 0.96 ns. -0.06 0.77 ns. cal 0.12 0.53 ns. -0.05 0.82 ns. salivary variables study group control group statistical test mean ± sd mean ± sd t-test p-value salivary flow rate 0.75 0.27 1.25 0.29 -7.11 0.00** ca(mg/dl) 1.89 1.04 2.34 0.89 -1.77 0.08 p (mg/dl) 9.70 2.84 7.72 2.00 3.13 0.00** zn(µg/dl) 2.61 0.79 4.72 0.93 -9.45 0.00** cu(µg/dl) 4.55 0.84 2.59 0.30 12.03 0.00** tp(mg/dl) 83.07 10.90 79.38 15.95 1.05 0.30 j bagh college dentistry vol. 27(3), september 2015 salivary tumor pedodontics, orthodontics and preventive dentistry127 discomfort to the patient,because of these significant characteristics, finding biomarkers in saliva for the detection of serious systemic illnesses, such as cancer, is of great interest for most salivary researchers. the tumor marker ca15-3 (muc1) is a high-molecular-mass glycoprotein, that expressed at the luminal surface of most secretary epithelial (25), it is the best and the most extensively used tumor marker in breast cancer as its expression greatly increases in most breast carcinomas (26), the data of the present study showed that the level of the tumor marker ca15-3 was higher among breast cancer group with a highly significant difference, this result agreed with that reported by streckfus (27) in stimulated whole saliva and also agha-hosseini (13)found the same result in unstimulated saliva. the correlations between ca15-3 and dmfs, gi and cal were weak not significant and may indicate that ca15-3 has no effect on oral health, but further studies are required concerning the effect of ca15-3 on dental caries and periodontal diseases. data of the present study showed that caries experience represented by dmfs and ds components among breast cancer group was higher than that of control group but the difference was statistically not significant, this result agreed with that reported by kanan (22) and tojal et al. (5), the increased caries experience among breast cancer group could be attributed to the reduction in the salivary flow rate as the flow rate in this study was lower among breast cancer group with a highly significant difference and the correlation with ds in the breast cancer group wasinverse not significant,as the salivary flow rate play an important role in relation to dental caries because of the washing action of saliva as well as its protective constituents that increased with increasing flow rate (8,28). the other important factor that may affect caries experience in saliva is its constituents (29). in the present study, although statistically not significant, inverse correlations were recorded between caries-experience (dmfs) and salivary elements (ca and p) in both groups, this could indicate the importance of calcium and phosphorus as their presence in saliva may greatly affect remineralization and increase resistance of outer enamel surface to acid dissolution (9,29). measurement of salivary zinc showed alower mean value recorded in study group than control group with statistically highly significant difference,this reduction may be due to the reduction of zinc levels in serum of patients with breast cancer (30,31). in additionnon-significant negative weak correlation between salivary zinc and ds in study group was recorded, these findings can explain the higher caries experience among the study group because it was found that zinc have a role in tooth mineralization, and accumulation of zinc quantities on enamel surface made teeth more caries resistance (32). increased susceptibility to dental caries in zincdeficient animals might be mediated by alterations in salivary proteins that are associated with the maintenance of tooth structure (33). while for copper ions in saliva the results of the present study showed higher concentration level in breast cancer group,this result may be attributed to the high levels of copper in serum of breast cancer patients (30,31),beside that current study showed non-significant inverse weak correlation between copper and dmfs and ds fraction, this inverse relation can be attributed to copper's ability to inhibit bacterial growth because the divalent metal ions properly inhibit glycolysis in dental biofilm and its antibiofilm effect related to antimicrobial activity and displacement of ca ions from pellicle and microbial surface and change of microorganism adherence (34), and also its ability to directly inhibit acid dissolution of enamel (35). total protein in the current study showed a higher level in breast cancer group than control group with no significant difference between them, a not significant positive correlation was found between total protein and dmfs/ds in breast cancer group, and a significant positive relation was found in control group. these results can be attributed to the fact that some salivary proteins are essential source of nutrient for bacteria and encourage bacterial aggregation (36), this may involve cariogenic bacteria as well, which in turn may increase the risk to dental caries. another explanation for the increased caries experience among breast cancer group is the poor oral hygiene as reported in the present study by highly significantly higher plaque and calculus accumulation among breast cancer group, as dental plaque was found to be the primary etiological factor in dental caries pathogenesis (8,37). in the present study the results showed that the study group has a higher mean value of gingival inflammation and clinical attachment loss than control group with a highly significant difference between them this could be attributed to the poor oral hygiene as indicated by the higher plaque and calculus accumulation among the study group than control group with a highly significant difference between them, these results agreed with those reported by kanan (38). since j bagh college dentistry vol. 27(3), september 2015 salivary tumor pedodontics, orthodontics and preventive dentistry128 poor oral hygiene plays an important role in the etiology and progression of periodontal disease (39,40). saliva may affect periodontal diseases through its physiochemical properties (24), this can be explained by that the salivary flow rate may play an important role in relation to plaque accumulation since decrease of salivary flow rate lead to decrease of washing action of saliva as well as the protective constituents decreased with decreased flow rate (41). the increased gingival inflammation of breast cancer group in the present study may be also attributed to the fact that alteration in estrogen and progesterone hormones level due to breast cancer (42,43) may affect the gingival tissues, as these tissues respond to increased levels of estrogen and progesterone by undergoing vasodilatation and increased capillary permeability also there is an increased migration of fluid and white blood cells out of blood vessels. the other 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288: 872. 44. mirza kh, al-saidy a, mohammed ch. the prevalence and severity of periodontal diseases in different stages of pregnancy and in women taking oral contraceptive pills in sulaimani city, kurdistan region, iraq. diyala j medicine 2013; 4(1): 61-73. الخالصة ؤثر على الصحة العامة اضافة و یعتبر من االمراض الخطیرة التي ت .وفي العراق لدى النساء في جمیع أنحاء العالم شیوعًاالسرطانیةأكثر األورام من سرطان الثدي ھو:خلفیة الموضوع وعناصر ca15-3المؤشر الورمي وقد اجریت ھذه الدراسة لتقییم .تؤثر سلبا على صحة الفمالفیزیائیة والكیمیائیة والتي اللعاب خصائصالى تاثیره على صحة الفم وخاصة على .االسنان ضمن مجموعھ من النساء المصابات بسرطان الثدي ومقارنتھم مع المجموعة الضابطةمختارة في اللعاب وعالقتھم بصحة الفم و )المجموعة تحت الدراسة(امرأة ٣٠,التعلیمي لكاظمیةسنة من المراجعات لمستشفى ا ٤٥ -٣٥باعمار تتراوح بین ٦٠نوعددھ النساءشملت الدراسة مجموعة من : المواد والطرق على او اعراض سریریةتشتمل على نفس المواصفات ولكن لیس لدیھم اي عالمات ) المجموعة الضابطة(امرأة اخرى ٣٠و قبل البدء بالعالجسرطان الثدي ب نشخصت حدیثا اصابتھ ، وقد تم استخدام )١٩٨٧(للعام حسب منظمة الصحة العالمیة (dmfs))تسوس، قلع، حشوة(مقیاس من خاللاالسنان وكان التشخیص و حساب شدة تسوس .االصابة بسرطان الثدي على التتابع وبالنسبة لمعدل تلف األنسجة ) ١٩٥٩(، ورامفورد )١٩٦٣(، ولو وسلنس )١٩٦٤(مقیاس الصفیحة الجرثومیة، التھاب اللثة، والقلح على االسنان تبعا لتصنیف سلنس و لو :اللعاب المحفز حیث سجل مستوى جریان اللعاب ، ثم تم تحلیل العینات كیمیائیا لتحدید التراكیز لكل من تم جمع عینات من ). ١٩٥٩(الرابطة فقد تم تحدیده وفقا لمقیاس رامفورد .الكالسیوم، الفسفور، الخارصین، النحاس، إضافة إلى البروتین الكلي, ca15-3المؤشر الورمي كما وجد .مع عدم وجود فرق معنوي بین المجموعتینالضابطة كان أعلى بین المجموعة تحت الدراسة من المجموعة ) dmfs(قیمة تسوس األسنان أظھرت النتائج أن متوسط :النتائج . صائیاإح =مع وجود فرق معنوي عال أعلى بین مجموعة الدراسة مقارنة بالمجموعة الضابطةتلف األنسجة الرابطة , التھاب اللثة, القلح, ان القیمة المتوسطة للصفیحة الجرثومیة . احصائیا =في لعاب النساء المصابات بسرطان الثدي كان اعلى من النساء في المجموعة الضابطة مع وجود فرق معنوي عال ca15-3واظھرت النتائج ان مستوى المؤشر الورمي , وقد سجلت الدراسھ تراكیز عالیة لكل من الفسفور.احصائیا =وي عالجریان اللعاب كان اقل بین مجموعة الدراسة مقارنة بالمجموعة الضابطة مع وجود فرق معنمعدل انلوحظ وقد بینما كانت تراكیز كل . احصائیا بالنسبھ للفسفور والنحاس =النحاس و البروتین الكلي في لعاب النساء في المجموعة تحت الدراسة مقارنة بالمجموعة الضابطة مع وجود فرق معنوي عال . بالنسبة للخارصین =المجموعة تحت الدراسة مقارنة بالمجموعة الضابطة مع وجود فرق معنوي عال من الخارصین والكالسیوم اقل في ولقد اضافت نتائج ھذه الدراسة دعما لمفھوم . اظھرت الدراسة ان النساء المصابات بسرطان الثدي لدیھن نظافة فم واطئھ و معدالت حدوث امراض لثة وتسوس اسنان عالیة:االستنتاجات .الموجود في اللعاب للكشف عن مرض سرطان الثدي او متابعة المرضى الالئي یتم عالجھن من سرطان الثدي بعد العملیھ ca15-3نیة استخدام المؤشر الورمي امكا j bagh college dentistry vol. 28(4), december 2016 physical and histological oral diagnosis 89 physical and histological evaluation of coated implant with nano zro2 after creation titania nanotubes mustafa sh. alhilfi, b.sc. (a) athraa y. alhijazi, b.d.s., m.sc. ph.d. (b) abstract background: contact between implant material and bones must be strong and fast creation, to fulfill these properties appropriate surface modifications must apply on used implants. in this contribution; double surface modifications are applied on ti-6al-4v alloy to accelerate osseointegration. materials and methods: anodic process is utilized to create titania nanotubes (tnts) on the screws made from ti-6al4v alloy. these implants were coated with nano zro2 particles. second modification was annealing anodized screws at 8000c, and implanted in tibiae of nine adult new zealand white rabbits. results: physical and histological consequences of two surface modifications on ti-6al-4v alloy screws were studied. scanning electron microscope (sem) images shows inhomogeneous distribution of tnts on screws surfaces. x-ray diffraction (xrd) patterns illustrate the covering of first group samples with zro2 and transformation of ti to its oxide (rutile phase) for second group. these pattern shows that tio2 had higher crystallinity and larger grain size than zro2. atomic force microscopy images (afm) shows the increasing of roughness, grain size and internal diameter of tnts after annealing process. coated implant with zro2 at 4 month duration shows threads with newly haversian canal feature. annealed implant at same duration shows well developed threads, base of implant illustrates bone trabeculae filled the base of implant bed with active osteoblast cells. conclusion: modification of implant's surface produced an improvement of osseointegration in comparison to untreated one. keywords: zro2, titanium nanotubes, annealing, osseointegration and electrophoretic deposition. (j bagh coll dentistry 2016; 28(4):89-95) introduction surface modification (within the field of biomaterials) is of special interest since the interaction between the living tissues (including blood and arteries) and implanted devices are mediated by reactions at the surface of the implant; biocompatibility is widely be considered as a surface property (1). difference surface modifications have been experienced to ti and its alloys to enhance bone differentiation and consolidate direct contact between implant material and bones. however for long periods, none of these modifications have produced a durable interface strong enough to support functional loading. hence, there is specific necessity to develop implants with surface coatings designed to improve bone anchorage through enhanced osseointegration (2). attempts to improve the osteoconductivity of medical alloys can be divided into two techniques: coating metallic implants with bioactive materials to accelerate bone formation , and forming rough surface at the macro-level on these implants and the ingrowth of bone results in anchorage of the implants (3). (a)department of physics, college of education, al-mustansiriya university (b)professor. department of oral diagnosis, college of dentistry, baghdad university the integration of the implant into bone takes place largely at the tissue-implant interface. development of this interface is complex and involves numerous factors. these include not only implant related factors, such as material, shape, topography and surface chemistry, but mechanical loading, surgical technique and patient variables, such as bone quantity and quality, as well (4). because of their good combination of mechanical properties and excellent biocompatibility, zircona ceramics are recognized as one of the best biomaterials for dental prostheses (5). this material is chosen in form of nanoparticles to coat ti-6al-4v alloy after creation tnts on its surface. annealing process (the second surface modification) has many merits in improving the performance of tnts as active biomaterial. this process can reduce contamination of species from the electrolyte or organic solvents (6), improved the stability of tnts samples (7), activated the anodic oxidation layer and the surface becomes bioactive (8). the aim of this work is investigation the effect of covering tnts with nano zro2 and annealing these tubes for getting best osseointegration. materials and methods 1samples preparation ti-6al-4v alloy discs shapes were prepared by using wire cut machine. these samples were j bagh college dentistry vol. 28(4), december 2016 physical and histological oral diagnosis 90 utilized for characterization purposes. the same material was used to make medical screws with following dimensions: the head diameter was 3.5mm while body was 3mm in diameter. they have a slide in the head of 1.5mm depth and 1mm width. ultrasonic cleaning bath (sonomatic/170-2-t80, germany) with ethanol and acetone of 75:25 wt% ratio was carried out to removing debris and contamination from the fabricated samples. 2samples characterization the crystalline nature of the materials was tested by x-ray diffractometer (xrd) using cu kα radiation. surface morphology of the modified surfaces was examined using scanning electron microscopy (sem), type (jeol-jsm5600). 3anodic and annealing processes to create tnts on screws anodic process was used, the details are mentioned in reference (9). after anodic process; the thermal treatments on samples were performed in a tubular furnace for two hours at 800°c. 4coating with zro2 efd method was used to deposit nano-zro2 material on screws after creation tnts on their surfaces. amer et al. (10) mentioned deposition details of this material on ti-6al-7nb alloy. the deposition conditions were: deposition time 3 min, applied voltage 50 volt, collide temperature 25 ºc and the distance between electrodes was 1 cm. sintering of the coated screws was carried out using carbolite furnace type mtf, england. the treatment was done at 800 ºc under inert gas (argon), to prevent oxidation of the specimen. figure 1 shows untreated, annealed and coated samples. 5surgical implantations and specimens collection nine adult new zealand white rabbits weighing 1.5-2 kg were used. for each rabbit, two screws were implanted in the right tibia (untreated and annealed), coated screw with zro2 was implanted in left tibia. the details of surgical implantation were mentioned in reference (11). specimens of bone with different implant samples were subjected to decalcification process and the slides were stained by h&e stain and examine under light microscope. figure 1: from left: untreated, coated with zro2 and annealed sample. results and discussion figure 2 shows xrd pattern of untreated, annealed and coated ti-6al-4v alloy. annealed sample has mixed peaks, first type belongs to titanium and the second one belongs to titanium oxide. strong lines of xrd profile of annealed alloy with the following miller indices (hkl): (110), (101), (111), and (211) belong to (rutile phase) (jcpds file no. 211276).this reflections indicating that the as-annealed nanotubes layers are crystallized. inside this pattern there is strong lines with high intensity can be assigned to alpha phase titanium with miller indices (101) and (100) (jcpds file no.441294). this refers to incomplete transformation to tio2 by annealing process. strongest reflections peaks for coated sample are (-111) and (111) which could be indexed to zro2 monoclinic phase corresponding to jcpds file 37-1484. comparing the values of full width at half maximum (fwhm) between the dominant peak of annealed and coated samples shows that the grain sizes of the former larger than that of latter. also, tio2 consists of highly crystalline form, since narrower peaks represent higher levels of crystallinity. j bagh college dentistry vol. 28(4), december 2016 physical and histological oral diagnosis 91 figure 2: xrd patterns of untreated, annealed and coated samples. figure 3(a) shows the sem image of tnts which were created on medical screws fabricated from ti-6al-4v alloy. these nanotubes are not uniform or have the same length over entire surface; this is might due to the effect of the geometric design of machined screw. it’s well known that (12): on the binary α + β type ti alloys, inhomogeneous nanotube formation takes place. on the surface of this body the arrays of nanotubes formed on α phase region while the selective dissolution of β phase occurs, leading an inhomogeneous oxide nanotube layer. eds spectra of anodized screw are illustrated in figure 3 (b). the concentrations of the elements are listed in table (1); these concentrations did not seem to be directly related to the overall composition of ti-6al-4v alloy. anodized alloy contains 69.3% ti and 19.077% o which is not close to the stoichiometric composition of tio2 .so ti does not transforms completely to titania phase after anodization. wt% of vanadium element in table has zero value because of the overlapping between ti-kβ line and v-kα line. figure 3. for anodized ti-6al-4v. a-sem image. beds spectra. a b j bagh college dentistry vol. 28(4), december 2016 physical and histological oral diagnosis 92 table 1: concentration of anodized ti-6al-4v alloy elements determined by eds at% wt% energy (kev)of kα1 lines atomic number the element 19.077 7.822 0.523 8 o 69.297 85.07 4.51 22 ti 8.948 6.185 1.487 13 al 0 0 4.951 23 v figure (4-a and c) shows atomic force microscopy (afm) images for anodized and annealed alloy. this image illustrates the effect of annealing on tnts. figure (4-b and c) illustrates upper views of single ti nanotube on anodize and annealed samples respectively. table 2 shows the data of afm images of anodized and annealed ti-6al-4valloy. these data confirm the increasing of roughness, grain size and internal diameter of tnts after annealing process. the increasing of roughness has good effect on accelerate osseointegration. table 2: afm images parameters of anodized and annealed samples sample's type roughness average (nm) grain size (nm) internal diameter of tnts (nm) anodized alloy 1.2 96.40 171 annealed alloy 2.7 171.57 572 figure 4: (a),(c):afm images of anodized and annealed ti-6al-4v alloy respectively. (b),(d): measurement of ti–tube after anodic and annealing processes respectively. ti nanotube diameter (μm) d a ti nanotube diameter (μm) b c j bagh college dentistry vol. 28(4), december 2016 physical and histological oral diagnosis 93 removal torque forces have been used as a biomechanical measure of anchorage or osseointegration in which the greater forces required to remove implants may be interpreted as an increase in the strength of osseointegration (13). table 3 illustrates the effect of current surface modification to build strength bonding between implants and bone tissue. table 3: average values of removal torque values of untreated and treated samples after implantation for four months treatment type average values of removal torque values (n.cm) untreated 40 anodized and coated with zro2 55 anodized and annealed at 8000c 65 histological findings untreated implant at 4 month duration shows threads with immature bone feature, base of implant illustrates fine and few trabeculae with active osteoblast cell rimming the bone, figure 5(a,b,c). coated implant with zro2 at 4 month duration shows threads with newly bone formation, base of implant illustrates fine, numerous trabeculae with active osteoblast and osteocyte cells, figure 6(a,b,c). the enhancement of bone formation at the bone-implant interface has been achieved through the modulation of osteoblasts adhesion and spreading, induced by structural modifications of the implant surface, particularly at the nanoscale level (14). in present results the improvement of the bone-forming activity at the bone-implant interface for coated implant with zro2 is committed to nanoscale features that have the ability to induce the differentiation of stem cells along the osteogenic pathway and because of their ability to differentiate into different types of functional cells, as they posses great potential to restore and regenerate native tissues (15). for annealed implant at 4 month duration, result shows well developed threads, and the base of implant illustrates bone trabeculae that filled the base of implant bed with active osteoblast cells, figure 7(a,b,c).the present result shows the great potential for the conversion of natural by-product into highly valuable compounds for bioapplications, using a simple and effective valorization process (16). in addition, the improvement in bone-implant interface shows to be more by use of natural biomaterial rather than the synthetic. as a conclusion; due to its high roughness and histologic findings that revealed for annealed process, it had superiority in production of active osseointegration, in comparison to others. figure 5: untreated implant at 4 month: athreads (arrows)x4. b-bone trabeculae (bt) at base of implant bedx10. cbone trabeculae (bt) rimming by osteoblast(arrows)x10. a b c j bagh college dentistry vol. 28(4), december 2016 physical and histological oral diagnosis 94 figure 6: coated implant with zro2 at 4 month. athreads (arrows)x10. b-bone trabeculae (bt)at base of implant bedx10. cactive osteoblast (arrow); osteocyte (arrow head)x20. figure 7: annealed implant at 4 month. awell developed threads (arrows) x20. b-bone trabeculae (bt) filled the base of implant bedx10. cbone trabeculae rimming by osteoblast (arrow) x40. references 1. peter k. sol-gel-derived zirconia thin film coatings for ti-6ai-4v and 316l stainless steel implant applications. a master thesis, university of toronto,1997. 2. zreiqat h, valenzuela s m, nissan b b, roest r, knabe c, radlanski r j, renz h, peter j. evans pj. the effect of surface chemistry modification of titanium alloy on signalling pathways in human osteoblasts. biomaterials 2005; 26: 7579– 86. 3. kuroda k, okido m. hydroxyapatite coating of titanium implants using hydroprocessing and evaluation of their osteoconductivity. bioinorganic chemist appl 2012; article id: 730693, 1-7. 4. doblar m, garc jm, gomez mj. modelling bone tissue fracture and healing: a review. engineering fracture mechanics 2004; 71: 1809–40. 5. chevalier j. what future for zirconia as a biomaterial? biomaterials 2006; 27: 535-43. 6. regonini d, jaroenworaluck a, stevens r, bowen cr. effect of heat treatment on the properties and structure of tio2 nanotubes: phase composition and chemical composition. surf interface anal 2010; 42: 139-44. 7. anca m, georgeta v, roxana t, daniela i. heat treatment of tio2 nanotubes, a way to significantly change their behavior. u.p.b. sci bull series b 2011; 73(1): 97-108. 8. lukáčová h, plešingerová b, vojtko m. bioactivity of chemical, electrochemical and thermal treatment of ti-6al-4v. acta metallurgica slovaca 2011; 17(1): 11-7. 9. mustafa sh a, thair la. corrosion characterization of medical alloys modified by forming titanium nanotubes via anodic oxidation and annealing process. j materials technol 2013; 28(6): 297-304. 10. waheed as. mechanical and histological evaluation of nano zirconium oxide coating on titanium alloy ti-6al-7nb dental implants, baghdad university, 2013. 11. mustafa sha , thair la, al-hijazi ay. enhancement of early osseointgration by coating tio2 nanotubes with annealed fishbone (in vivo study). j natural science res 2014; 4(2): 38-47. 12. emanuela s, fedor f, maria n, margitta u, et al. ti -6 al-7nb surface modification by anodization in electrolytes containing hf. u.p.b. sci bull series b 2012; 74(2): 277-88. 13. jung-wk. biomechanical evaluation of dental implants with different surfaces: removal torque and a b c a b c j bagh college dentistry vol. 28(4), december 2016 physical and histological oral diagnosis 95 resonance frequency analysis in rabbits. j adv prosthodont 2009; 1:107-12. 14. variola f, yi jh, richert l, wuest jd, rosei f, nanci a. tailoring the surface properties of ti6 al4v by controlled chemical oxidation. biomaterials 2008; 29: 1285–98. 15. atala a, lanza r, thomson ja, nerem rm. principles of regenerative medicine. burlington: elsevier; 2008. 16. piccirillo c, silva mf, pullar rc, braga da cruz i, jorge r, pintado mm, castro pm. extraction and characterization of apatiteand tricalcium phosphatebased materials from cod fish bones. mater sci eng c mater biol appl 2013; 33(1): 103-10. http://www.ncbi.nlm.nih.gov/pubmed/25428050 http://www.ncbi.nlm.nih.gov/pubmed/25428050 http://www.ncbi.nlm.nih.gov/pubmed/25428050 j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 59 j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 cd34 and wnt3 expression in potentially malignant oral disorders noroz hama-rashid nader, f.k.c.m.s. (1) ibrahim saeed gataa, f.i.c.m.s. (2) dena nadhim mohammad, ph.d. (3) balkees taha garib, ph.d. (4) abstract: background: potentially malignant oral disorders (pmod) are common precursors of oral squamous cell carcinoma (oscc). neoangiogenesis and signalling are important intermediate biomarkers that may govern the progression of dysplastic mucosa into carcinoma. aims: evaluate the importance of cd34 and wnt3 expression in pmod and oscc in relation to their clinicopathological parameters. settings and design: prospective cross-sectional study. materials and methods: immunohistochemical staining for cd34 and wnt3 was performed for 41 samples. these included 27 pmod, six oscc and eight normal gingival and alveolar mucosa. analysis of variance (anova) and post-hoc tests were applied. p<0.05 was considered statistically significant. results: cd34 expression showed a significant difference between groups (p<0.05). cd34 expression decreased in patients who had pmods, and it was seen to correlate with clinical staging in oscc patients. the alveolar epithelia had lower microvessel density (mvd) (9.3±.88) than the gingiva (17.47±5.09) (p<0.05), whereas the lichen planus without dysplasia had lower mvd (8.85±3.95) than both the gingiva and the dysplastic epithelia (14.46±3.89) (p<0.05). on the other hand, wnt3 expression was not detected in the alveolar mucosa, but scattered perinuclear and nuclear expression in the gingival mucosa was observed. cytoplasmic wnt3 expression was seen in all oral lichen planus (olp) and some leukoplakia cases with no nuclear staining, whereas its expression in proliferative verrucous leukoplakia was only nuclear. furthermore, oscc showed both cytoplasmic and nuclear expression. conclusion: mvd may represent a useful biomarker preceding oral cancer development. it increases from normal mucosa to dysplasia to carcinoma. aberrant cytoplasmic expression of wnt3 is detected in pmod and oscc. thus, wnt3 may be involved in disease progression. keywords: potentially malignant oral disorders, oral squamous cell carcinoma, microvessel density, cd34, wnt3. (j bagh coll dentistry 2017; 29(3):59-67) introduction: a precancerous lesion is a benign, morphologically altered tissue that has a greater than normal risk of malignant transformation and is not necessarily showed clinical alteration. malignant transformation potential is defined as the likelihood of cancer being present in a precancerous condition or lesion, either at initial diagnosis or in the future.(1) dysplasia represents a spectrum of changes with no precise, distinct stages. the inconsistency in dysplasia assessments is attributed to the lack of guidelines for interpretation. pathologists still need to improve consistency in interpreting transitions in the grades of severity of dysplasia.(2) the world health organization (who) monograph on head and neck tumours (2005) recommends the term ‘potentially malignant oral disorders’ (pmods). (1)oral and maxillofacial surgery, teaching hospital, ministry of health (2) professor. department of oral surgery, school of dentistry, faculty of medical sciences, university of sulaimani. (3)lecturer. department of oral pathology, school of dentistry, faculty of medical sciences, university of sulaimani. (4)professor. department of oral pathology, school of dentistry, faculty of medical sciences, university of sulaimani. this term conveys that not all lesions and conditions described under this term will transform into cancer; rather, this term refers to a family of morphologically altered lesions that may have increased the potential for malignant transformation.(3) oral squamous cell carcinomas (oscc) appear to arise in the apparently normal mucosa, in otherwise healthy people; however, some lesions are preceded by clinically obvious pmod.(4) the main pmod described in the literature are actinic cheilitis, erythroplasia, leukoplakia (homogeneous, speckled, nodular-verrucous, proliferativeverrucous, sublingual, candidal, syphilitic), erosive oral lichen planus (olp), submucous fibrosis, palatal lesion in reverse smokers, and other systemic conditions associated with pmod.(4) erosive olp has a 0.4–2.5% chance of carcinoma transformation; its behaviour differs from that of other olp forms or lichenoid eruptions that are not reported to be pmods.(1) the screening of pmods, particularly those that appear normal but have tumorigenic potential, is crucial to treatment success. the early diagnosis j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 60 of oral lesions is the key to preventing progression to advanced stages of the disease.(5) currently, visual and cytology-based techniques are used by clinicians to detect dysplasias and early stage osccs. these approaches are limited in their ability to judge the severity of lesions and are primarily useful after the appearance of visual changes.(5) angiogenesis is a complex process that encompasses the growth and migration of endothelial cells and capillary morphogenesis. cd34 is a sensitive marker for endothelial cells. it is a transmembranous glycoprotein that functions in early hematopoiesis.(6) immunohistochemical staining for cd34 is used to evaluate microvessel density (mvd) in numerous tumours, and intratumoral mvd has been established to be useful in predicting relapse or metastasis.(7) siar et al. indicate that formation of angiogenic squamous dysplasia-like complexes in oral precursor lesions may be a useful predictive marker of oral malignancy.(7) on the other hand, wnt paracrine signalling molecules consist of a family (19 members in humans) of well-conserved secreted glycoproteins.(8) wnt3 expression is detectable in dysplastic lesions (oral leukoplakia), but not in normal oral epithelia, suggesting a potential involvement of this marker in dysplasia.(9) the present study aimed to investigate the importance of cd34 and wnt3 as markers for malignant transformation of pmods in comparison to their importance in oral carcinomatous lesions and to correlate the findings with the clinicopathological parameters. materials and methods: this prospective cross-sectional study was conducted in sulaimani, during the period from april 1st, 2012 to the end of november 2014. the study was approved by the ethical and scientific committees of the faculty of medical sciences. signed informed consent, medical history, and clinical data were obtained from each participant before sample collection. a total of 41 samples were collected. the negative control group included eight clinically normal-looking oral epithelia taken from non-smoking patients aged between 20 and 40 years. four of these were keratinized oral mucosa obtained from the gingiva of patients undergoing impaction removal; these are thick mucosa with papillary hyperplasia. the other four samples were non-keratinizing lining alveolar mucosa that showed poorly developed papillae (thin mucosa) obtained during dental implantation. the test group included 33 cases; 27 pmods, and six osccs. the pmods subgroup included 21 cases of erosive lichen planus and six cases of leukoplakia diagnosed during the study period. formalin fixed paraffin embedded blocks were prepared, and three serial tissue sections were cut. one section was stained with haematoxylin and eosin for histopathological diagnosis and dysplastic staging. the other sections were subjected to immunohistochemical staining. the slides were kept in the oven (60ºc, six hours) and then tissue sections were deparaffinised, rehydrated and washed with phosphate buffer saline (pbs) (five minutes). the sections subjected to antigen retrieval (boiling citrate buffer ph 6, for 15 minutes), then they were allowed to cool and washed with pbs (three minutes); the excess buffer was tapped off gently. hydrogen peroxidase was applied (37ºc for 10 minutes) followed by protein blocker (37ºc for 10 minutes). next, primary monoclonal anti-cd34 antibody (1:150) and polyclonal anti-wnt3 (1:100) (abcam) were applied separately, one on each of the sections subjected to staining in a humid chamber (37ºc for 45 minutes). complement was added (10 minutes). goat anti-rabbit horseradish peroxidase conjugate was applied (15 minutes), followed by diaminobenzidine (dab) chromogen (five minutes in a dark field), then counter-stained with hematoxylin for 20 seconds and washed in distilled water. lastly, sections were dehydrated, cleared and mounted. the negative controls for the staining procedure were performed by omitting the primary antibody and applying the antibody diluents alone. the positive control for cd34 involved internal staining of arterioles in the tissue sections,(7) whereas osccs served as a positive control for wnt3.(9) sections stained with cd34 were initially evaluated at low power (x40) to identify four ‘hot spot’ areas in the connective tissue papillae and lamina propria. the mvd counting was performed at a higher magnification (x400). the cd34 positive endothelial cells or clusters of endothelial cells that were separate from adjacent microvessels or other connective tissue elements were regarded as a single countable microvessel. the average mvd score was calculated.(7) in normal oral epithelia and pmods, microvessels located just underneath the epithelium were considered, whereas in osccs those located in between the islands were considered. sections stained with wnt3 were evaluated according to its distribution in the epithelial layers (basal, suprabasal and spinous layers), and intracellular localisation (nucleus j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 61 and cytoplasm). four fields were randomly selected to identify positive cells at x400 (9). one-way anova test and posthoc tests (tukey’s test) were applied to estimate the differences among and between groups by using spss 20.0 software. p<0.05 was considered statistically significant. results: the clinical features of patients are illustrated in table 1. the pmods involved a wide age range (27–75 years) with nearly equal age group distribution. the cheek was the predominantly affected site. most of the patients were non-smokers. pmods had an equal frequency of presentation as homogeneously white (48.15%) and red and white lesions (48.15%) (figure 1). on the other hand, oral carcinomas were seen more frequently in older age groups; 66.67% presented with an ulcer, and 33.3% involved the cheek. however, none of the patients reported being smokers (table 1). nevertheless, 50% of oscc patients were at an advanced clinical stage (table 2). histologically, four erosive olps (19.05%) displayed dysplastic changes, whereas all cases of leukoplakia showed dysplastic changes. thus, the total number of pmods with dysplastic changes was ten (37.04%). five of these (50%) were in grade two and four cases (40%) were in grade three. lastly, four cases (66.67%) of osccs were categorized as welldifferentiated carcinoma (table 2). after immunohistochemical staining, six samples of pmods were excluded (either they contained not enough surface epithelium to be evaluated or the connective tissue tore). therefore, the remaining 21 samples of pmods included 18 olps (16 without dysplasia and 2 with dysplasia) and three cases of leukoplakia were examined for cd34 and wnt3 expression. immunohistochemical expression of cd34 was assessed in terms of mvd. in both osccs and pmods the mvd did not differ in relevance to clinical parameters except for the significant pearson correlation with clinical staging (r = 0.94, p =.006), (table 3). histologically, the mean of mvd revealed higher expression in gingival mucosa than in the alveolar mucosa (17.47 vs. 9.3, p<0.05). in addition, there was a significant difference between lichen planus without dysplasia (8.85, p<0.05) on the one hand and keratinized gingival epithelium and dysplastic epithelium on the other (figure 2 and table 4). the immunohistochemical expression of wnt3, was negative in alveolar oral epithelia, whereas the gingiva showed scattered perinuclear and positive nuclear expression. in olps and leukoplakia, the expression of wnt3 was mostly cytoplasmic, whereas its expression in proliferative verrucous leukoplakia was nuclear. wnt3 was positive in the osccs, both cytoplasmic and nuclear (figure 3 and table 5). discussion: the incidence and prevalence of pmod in selected populations vary considerably.(10) in sulaimani city, sabri (11) reported the prevalence of these lesions as 1.5%. the reported prevalence of leukoplakia is 2%, but worldwide prevalence for other types of pmod is unknown.(12) the rate of progression of pmod to oscc is estimated to be 36% when moderate epithelial dysplasia is present, but the rate increases up to 50% in lesions with severe dysplasia.(13) there is a growing body of evidence that the angiogenic process commences in the pre-malignant stages of most cancers.(14, 15) the presence of capillary blood vessels closely juxtaposed to and projecting into metaplastic or dysplastic squamous bronchial epithelia is a significant morphology to identify the preinvasive lesion.(16) previous authors have shown that a statistically significant increase in vascularity occurs during the transition from normal oral mucosa to different grades of dysplasia to invasive carcinoma,(7, 17) whereas other authors have failed to demonstrate such an increase.(18) this study showed that mvd in patients had pmods did not relate to any of the reported clinical parameters (sex, age, site, smoking, and presentation). it is worth to mention that lindeboom et al.(19) also did not find significant differences between the gingival capillary density of smokers and non-smoking, healthy individuals. furthermore, mvd showed no significant correlation with the dysplastic histological grade. the latter finding may be due to the few reported dysplastic lesions. concerning oscc, mvd is exclusive in its relation to clinical staging. tae et al.(18) also mentioned that there were no relationships among various clinicopathological factors and mvds in head and neck scc. the previously reported mean values of mvd in normal oral mucosa were either higher(18, 20–21) or lower (22– 24) than that reported in this study. these variations may be related to variations in sample location (gingiva, alveolar and buccal mucosa), sample size and cd34 interpretation. some authors examined a larger field area at a lower magnification and did not justify the depth, whereas others depended on j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 62 digital images. nevertheless, tahir et al.(25) estimated the mean mvd obtained from five samples of normal oral mucosa to be 9.2, which is approximately equal to our result found in the alveolar mucosa. we reported a difference in mvd in relation to sample site variations in clinically normal-looking mucosa. the gingival mucosa showed higher mvd than the alveolar mucosa as well as to the dysplastic lesions; that may be related to physiological need rather than pathological changes.(17). this finding was in line with the results of tae et al.(18) however, in this study, the normal alveolar mucosa was found to have lower mvd than dysplastic pmods; nevertheless, this difference did not reach a significant level, as tae et al. reported. the present findings of mvd regarding dysplastic pmod lesions are in agreement with those of the previous authors.(7, 17) thus, increasing vascularity as the epithelium progresses from normal non-keratinized epithelium to dysplasia indicates that cd34 may be an intermediary biomarker in pmods. olp is a chronic autoimmune disease with an inflammatory origin. it satisfies all the prerequisites of hypoxia that are essential for angiogenesis.(22) previous authors clarified that angiogenesis is significantly increased in olp compared to normal oral mucosa.(21, 22) the result of the present study did not support this concept. we observed that connective tissue papillae with dense lymphocyte aggregation underneath severely degenerated epithelia showed few blood vessels. wnt proteins consist of two groups based on their ability to activate wnt/β-catenin signalling. wnt3 is an efficient activator of the canonical pathway.(26) in the absence of wnt, cytoplasmic β-catenin immediately phosphorylated and degraded, thus disappearing.(27, 28) in this study, normal alveolar mucosa did not show wnt3 expression; this indicates that no signalling induction is required in the non-keratinized thin mucosa. while in the gingival mucosa, expression of wnt3 is limited to the nuclei or perinuclear area in dispersed cells. this finding contradicts the results of a previous study on wnt3 expression in the gingiva that showed negative expression (29) and supported that for negative expression of wnt5a in the skin.(30) there are no previously published articles on the role of wnt in the normal mucosa of other organs. the function of wnt3 in the nucleus or the cytoplasm has not yet been discussed. however, a study comparing the distribution of the nucleus and cytoplasmic compartment to gene expression indicates that various membranous proteins (like wnt3 in our study) can be stored in the nucleus or cytoplasm in relation to the ubiquitin cycle.(31) such localisation reflects the movement and segregation of molecules that do not relate to pathological changes. different molecular studies were used in olp to explore the possibility of malignant transformation, but this is the first study evaluating the expression of the wnt family in olp. wnt5a expression in cutaneous lichen planus has shown over-expression in all dermis and epidermis layers when compared with negative normal healthy skin.(30) in our study, wnt3 in olp was characterised by positive cytoplasmic expression (lack of nuclear staining). thus, positive aberrant cytoplasmic wnt3 expression suggests its role in the disease process. similarly dysplastic changes within olp did not alter this expression. these findings can be attributed to the lack of basal cells, which are responsible for cell renewal and signal induction. furthermore, the existence of positive and negative cytoplasmic with negative nuclear expression in oral leukoplakia in the present study is consistent with the results reported by ishida et al.(9) they found a difference in wnt3 expression between early stage and advanced stage dysplasia that could be related to nuclear βcatenin expression. the subjective evaluation of wnt3 expression provides quick, easy estimation of cellular expression and distribution and overcomes the use of the tedious counting method for a percentage of expression. conclusion the study indicates that cd34 and wnt expression may be useful biomarkers in malignant transformation of pmods. mvd was revealed to markedly increase through the progression from normal oral epithelia to premalignant lesions, thus indicating the role of the cd34 marker in predicting the ability of these lesions to progress toward malignancy. furthermore, the aberrant cytoplasmic localisation of wnt3 may be involved in the progression of pmods to oscc. references: 1. neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology, epithelial pathology.3rded. saunders: elsevier; 2009. 388-423. 2. warnakulasuriya s, reibel j, bouquot j, dabelsteen e. oral epithelial dysplasia classification systems: predictive value, utility, weaknesses and scope for j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 63 improvement. j oral pathol med.2008; 37:127133. 3. warnakulasuriya s, newell wj, van der waal i. nomenclature and classification of potentially malignant disorders of the oral mucosa. j oral pathol med.2007;36:575-580. 4. scully c. oral and maxillofacial medicine. 3 rd ed. potentially malignant disorders. churchill livingstone: elsevier. 2013. 174-204 5. mishra r. biomarkers of oral premalignant epithelial lesions for clinical application.oral oncol.2012;48:578-584. 6. eberhard a, kahlert s, goede v, hemmerlein b, plate kh, augustin hg. heterogeneity of angiogenesis and blood vessel maturation in human tumors: implications for antiangiogenic tumor therapies. cancer res. 2000;60:1388–1393. 7. siar ch, v. p. a. oo, nagatsuka h, nakano k, ng. kh, kawakami t. angiogenic squamous dysplasialike phenomenon in oral epithelial precursor lesions. eur j med res. 2009;14: 315-319. 8. mikels aj, nusse r. wnt as ligands: processing, secretion, and reception. oncogene.2006;25:74617468. 9. ishida k, ito s, wada n, deguchi h, hata t, hosoda m, et al. nuclear localization of betacatenin involved in precancerous change in oral leukoplakia. mol cancer.2007;6:62. 10. dionne kr, warnakulasuriya s, binti rz, and ching sc. potentially malignant disorders of the oral cavity: current practice and future directions in the clinic and laboratory(mini review). int. j. cancer. 2015;136:503–515. 11. sabri az. prevalence of oral premalignant and malignant lesions among referred kurdish patients attending department of oral and maxillofacial in sulaimani teaching hospital. the thesis of high diploma in oral medicine, sulaimani.2013. 12. petti s. pooled estimate of world leukoplakia prevalence: a systematic review. oral oncol. 2003;39:770–780. 13. scully c, bagan j, epstein j. oral cancer: current and future diagnostic techniques: review article. am j dent 2008;21:199-209. 14. tanigawa n, matsumura m, amaya h, kitaoka a, shimomatsuyat, lu c, et al. tumor vascularity correlates with the prognosis of patients with esophageal squamous cell carcinoma. cancer.1997;79: 220– 225. 15. kyzas pa, stefanou d, batistatou a, agnantis nj. prognostic significance of vegf immunohistochemical expression and tumor angiogenesis in head and neck squamous cell carcinoma.j cancer res clin oncol. 2005;131:624– 630. 16. keith rl, miller ye, gemmill rm, drabkin ha, dempsey ec, kennedy tc, prindiville s, franklin wa. angiogenic squamous dysplasia in bronchi of individuals at high risk for lung cancer.clin cancer res. 2000;6:1616-1625. 17. carlile j, harada k, baillie r, macluskey m, chisholm dm, ogden gr, et al. vascular endothelial growth factor (vegf) expression in oral tissues: possible relevance to angiogenesis, tumor progression, and field cancerization. j oral pathol med. 2001;30: 449–457. 18. tae k, el-naggar ak, yoo e, feng l, lee jj, hong wk, hittelman wm and shin dm. expression of vegf and mvd in head and neck tumorigenesis. clin cancer res. 2000; 6: 2821-2828. 19. lindeboom ja, mathura kr, harkisoen s, akker hp, ince c. effect of smoking on the gingival capillary density: assessment of gingival capillary density with orthogonal polarization spectral imaging. journal of clinical periodontology. 2005 ;32(12):1208-12. 20. michailidou ez, markopoulos ak and antoniades dz. mast cells and angiogenesis in oral malignant and premalignant lesions. open dent j 2008;2:126132. 21. mittal n, madhu shankari g s, palaskar s. role of angiogenesis in the pathogenesis of oral lichen planus. j oral maxillofac pathol. 2012;16:45-48. 22. scardina ga, ruggieri a, messina p, maresi e. angiogenesis of oral lichen planus: a possible pathogenetic mechanism. med oral patol oral cirbucal. 2009;14:558-562. 23. desai rs, mamatha gs, khatri mj, shetty sj.immunohistochemical expression of cd34 for characterization and quantification of mucosal vasculature and its probable role in malignant transformation of atrophic epithelium in oral submucous fibrosis.oral oncol.2010;46:553-558. 24. shivamallapa sm, venkatraman nt, shreedhar b, mohanty l, shenays. role of angiogenesis in oral squamous cell carcinoma development and metastasis: an immunohistochemical study. int j oral sci. 2011;3:216-229. 25. tahir a, nagi ah, ullah e, janjua os. the role of mast cells and angiogenesis in well-differentiated oral squamous cell carcinoma. j cancer research and therapeutics. 2013 ;9(3):387. 26. maye p, zheng j, li l, wu d. multiple mechanisms for wnt11mediated repression of canonical wnt signaling pathway. j biol chem. 2004;279:2465924665. 27. li h, pamukcu r, thompson wj: β-catenin signaling. cancer biol ther. 2002;1:621-625. 28. lustig b, behrens j.the wnt signaling pathway and its role in tumor development. j cancer res clin oncol.2003;129:199-221. 29. uraguchi m, morikawa m, shirakawa m, sanada k, and imai k. activation of wnt family expression and signaling in squamous cell carcinomas of the oral cavity. j dent res. 2004;83: 327. 30. zhang y, zhang d, tu c, zhou p, zheng y, peng z, feng y, xiao s, li z. wnt5a is involved in the pathogenesis of cutaneous lichen planus. clin exp dermatol. 2015; 40:659-64. 31. barthelson ar, lambert mg, vanier c, lynch mr, and galbraith wd. comparison of the contributions of the nuclear and cytoplasmic compartments to global gene expression in human cells. genomics. 2007;8: 340. j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 64 figure 1: clinical presentations of: a) erosive lichen planus. b &c) leukoplakia with surface keratosis. histological appearance of d) lichen planus without dysplasia, e) lichen planus with mild dysplasia. (x100): figure 2 :immunohistochemical expression of cd34 in (a) gingival mucosa. (b) proliferative verrucous leukoplakia. (c) oral lichen planus with mild dysplasia. (d) oral squamous cell carcinoma. (x400) a b d c a b c a d e j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 65 figure 3: immunohistochemical expression of wnt3. (a) alveolar mucosa. (b) gingival mucosa .(c) oral lichen planus without dysplasia. (d) oral lichen planus with mild dysplasia. (e&f) leukoplakia with dysplasia. (g) oscc.(h) proliferative verrucous leukoplakia. (x100 for all pictures except f, x 400). table (1): clinical characteristics of patients groups pmods (27) carcinoma (6) no. % no. % sex male 13 48.1 2 33.33 female 14 51.9 4 66.67 age 27-49 10 37 1 50-59 8 30 1 60-75 9 33 4 66.67 site cheek 16 59.2 2 33.33 tongue 7 26 1 16.66 floor 1 3.7 1 16.66 alveolar 1 3.7 1 16.66 upper lip 1 3.7 0 hard palate 1 3.7 1 16.66 smoking no 21 77.8 4 66.67 ex-smoker 3 11.1 2 33.33 yes 3 11.1 0 clinical presentation white (13) 48.15 mass (2) 33.33 white and red (13) 48.15 ulcer (4) 66.67 white and granular (1) 3.7 a b c d e f g h j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 66 table (2): histopathological characteristics of pmods and tnm staging of oscc groups dysplasia no. % grading for dysplasia pmods (27) lichen planus (21) without 17 62.96 i ii iii with (10) 37.04% 4 14.81 3 1 leukoplakia (6) idiopathic leukoplakia 4 14.81 1 2 1 chronic hyperplastic candidiasis 1 3.70 1 proliferative verrucous leukoplakia 1 3.70 1 oscc (6) histopathologic grading clinical tnm staging wd md pd i ii iii iv 4 1 1 1 2 0 3 table (3): mean value and standard deviation of mvd in relation to clinical parameters. clinical parameters pmods (n=21) oscc* no. mean sd p no. mean sd p sex male 10 10.05 4.73 0.9 2 14 2.8 0.32 female 11 10.30 4.6 4 11.37 1.3 age 27-49 9 10.13 5.39 0.208 1 16 50-59 8 8.56 3.57 1 10.6 60-75 4 13.55 2.97 4 11.7 2.57 site tongue 6 11.08 4.21 0.58 2 9.3 0.42 cheek 15 9.82 4.77 1 13.6 smoking no 15 10 4.44 0.853 0 0.83 ex-smoker 2 12 7.07 2 12.53 2.3 yes 4 9.97 5.19 4 11.96 0.77 clinical presentations white 13 8.96 4.27 0.119 mass 4 13.7 1.6 0.54 red & white 8 12.17 4.53 ulcer 2 10.3 0.4 * pearson correlation between mvds and clinical scc tnm staging ; r= -0.94, p=0.006. table (4): the relationship of the mvd to the histopathologic findings in all groups. groups subgroups no. mean sd anova tukey hsd control (8) alveolar mucosa 4 9.30 0.88 0.001 groups p value gingiva 4 17.47 5.09 alveolar vs gingiva 0.030 pmods (21) olp without dysplasia 16 8.85 3.95 gingiva vs olp without dysplasia 0.002 dysplastic lesions* 5 14.46 3.89 dysplasia vs olp without dysplasia 0.045 oscc 6 12.25 2.75 * three cases of leukoplakia and two cases of olp table (5): wnt3 expression and distribution in all groups. groups no. subgroups cytoplasmic nuclear control 4 alveolar mucosa ˗ve -ve 4 gingiva perinuclear +ve or cytoplasmic -ve +ve scattered pmods 16 l.p. without dysplasia +ve -ve 2 l.p. with dysplasia +ve -ve 2 leukoplakia(dysplasia) +/-ve -ve 1 proliferative verrucous leukoplakia -ve +ve carcinomas 6 oscc +ve +ve الخالصة سرطان الفم هى اصابات شائعة. وتولد االوعية الدموية يعتبر من العالمات المهمة لتحول هذه االصابات الى مراحل متقدمة.األصابات القابلة للتحول الى الدراسة : خلفية كعوامل في تحديد التطور في اآلفات القابلة للتحول الى أمراض خبيثة wnt3و cd34: تكمن أهمية هذه الدراسة فى تقييم الفحص المناعي الكيميائي بأستخدام اهداف الدراسة وسرطان الفم باألضافة الى تحديد العالقة بين الصفات السريرية مع الفحص المناعي الكيميائي لهذه األمراض. يج اللثة الطبيعي و سبع و عشرون من اصابات األمراض القابلة للتحول الى أورام استخدم في هذه الدراسة واحد و أربعون عينة اشتملت على ثمانية عينات من نس المواد و الطرائق: , بطريقة الفحص المناعي الكيميائي لجميع الحاالت والتحليل الحصائي باستخدام wnt3و cd34خبيثة وستة عينات من سرطان الفم الحرشفي. تم فحص جميع العينات بأستخدام anova.post -hoc , عتبرت القيمة االحصائية واp<0.05 . ذات تاثير احصائي مهم j bagh college dentistry vol. 29(3), september 2017 cd34 and wnt3 oral diagnosis 67 انخفاض واضح في األمراض القابلة للتحول الى أورام خبيثة cd34 ( بالمقارنة للمجاميع المستخدمة بالدراسة. واظهرcd34كان هناك ظهور احصائي واضح ل ) النتائج: (5.09±17.47)بمقارنة مع اللثة (88.±9.3). واظهرت ظهارة الغشاء المخاطي كثافة قليلة ل االوعية الدموية وارتبط ب التقدم السريري لمرضى سرطان الفم (p<0.05) (3.89±14.46)( مقارنة باللثة والظهارة ذات الخلل النسيجي (3.95±8.85, بينما اظهر الحزاز المسطح بدون الخلل النسيجي كثافه وعائية اقل (p<0.05) . رت تواجد في السايتوبالزم في الغشاء المخاطي للفم .بيمنما اظهر نسيج اللثة ظهور للعامل في النواة وحولها .جميع انسيجة الحزاز السطحي اظه wnt3لم يتم تحديد التقرن . سرطان الفم الحرشفي اظهر تواجد في كل من النواة والسايتوبالزم. وبعض الطلوان الفموي .بينما ظهر تواجد نووي في الطلوان المفرط التحول من النسيج الطبيعي الى سرطان الفم. تم تحديد ظهور تجاه ايتميز بالزيادة ب الى سرطان الفم . للتطورتعتبر كثافة األوعية الدموية المجهرية أحد العوامل الحيوية الألستنتاجات: عامل مهم في تحول هذه اآلفات الى سرطان wnt3في كل اآلفات القابلة للتحول الى أمراض خبيثة و سرطان الفم الحرشفي, لذلك يمكن اعتبار wnt3السايتوبالزمي الشاذ ل الفم. 8. shahed f.doc j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 44 the effect of plasma treatment on shear bond strength of high impact acrylic resin denture base lined with two types of soft lining materials after immersion in distilled water and denture cleanser shahad basim mustafa b.d.s. (1) thekra ismael hamad b.d.s., m.sc., ph.d. (2) abstract background: in dentistry, dentist takes the advantages of soft lining materials due to the viscoelastic properties. the major problem is the adhesion of the soft liner with the denture base material. materials and methods: heat cured of high impact acrylic resin specimens prepared with dimensions 75x13x13mm for shear bond strength test, soft lining material (refit and mollosil) with a 3-mm thickness and used to join each two acrylic blocks. also four specimens with the same previous dimensions utilized for chemical and physical surface analysis. the specimens grouped as control (without plasma) and experiment (with oxygen plasma) treated high impact acrylic specimens. results: plasma treatment increased the shear bond strength for both refit and mollosil soft lining material after immersion in distilled water for 30 days as compared with the control group, also there was decrease in shear bond strength for both refit and mollosil soft lining material of the experimental group after immersion in denture cleanser for 30 days as compared with the control (without plasma treated) group. afm analysis revealed that oxygen plasma treatment led to formation of (pits and protuberances) that increase the surface area and increase the shear bond between soft liners and high impact acrylic denture base. conclusions: oxygen plasma surface treatment was an effective method for increasing adhesion by physical topographic surface (due to the plasma etching process which in turn led to removal of some material from the surface and this led to increase the bond strength). key words: plasma treatment, soft liner material, high impact acrylic resin, shear bond strength. (j bagh coll dentistry 2015; 27(4):44-51). introduction denture fracture is a major problem for patients, dentists, and dental technicians (1). modifications of acrylic resin composition have been attempt by copolymerization with rubber to produce a high impact acrylic resins (2), high impact strength has a desirable properties like and a large yield point distance, high flexural strength, flexural modulus, which aid to resist torsional forces during function, leading to increase the prosthesis clinical service life (3). soft lining materials are employed to replace the intaglio of a conventional denture (heat cure acrylic denture) to achieve an equal distribution of the force, to reduce confined local pressures and to enhance retention of an ill-fitting denture by involving the undercuts (4,5). according to type of the material, soft liners can be silicone or acrylic based. according to type of curing system, they can be heat-cured or autocured, when the dentist can reline a denture directly in the patient mouth. the bond strength of heat-cured materials is greater than that of autocured products (6). (1)master student. department of prosthodontics. college of dentistry, university of baghdad. (2)assistant professor. department of prosthodontics. college of dentistry, university of baghdad. denture care is difficult and indispensable for old patients who cannot adequately brush their dentures due to general systemic disease, dementia and poor dexterity (7). denture cleansers and methods of cleaning used may cause harmful effect on the components of the denture or lead to loss of plasticizers and soluble components, or the resilient lining materials may absorbed water or saliva, which leads to changes in weight that influence their properties, thus, the denture cleanser selection should be considered to minimize or avoid the changes that may occur in the properties of resilient materials (8,9). plasma is a mixture of (electrons, ions, free radicals, and excited molecular states) in gaseous forms, created by inelastic collisions between ground state atoms (molecules) and high energy electrons. plasma treatments of polymer surfaces have been found to enhanced the hydrophilicity without changing the bulk properties of polymers which directly impact their function (10,11). materials and methods about 80 specimens made from impacryl hot (high impact acrylic resin) vertex, netherland were prepared for shear bond test. the specimens were grouped for each test done in the present study, as control plasma untreated, and oxygen j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 45 plasma treated, each group were divided into 2 subgroup (for refitacrylic based and mollosil silicone based soft liner) and these subgroups were divided into two subgroups for immersion in distilled water and denture cleanser for 30 days. plasma treatment: in the present study, a plasma apparatus with parameters: 800 v, 75ma, power 60 w, with 4 minutes exposure time, with the plasma source was kept 4.6cm above the test specimens, were used for all tests of the present study with the application of one type of plasma treatment (oxygen plasma treatments) figure (1). shear bond strength testing: a bout 160 blocks made from heat cure high impact acrylic with the dimensions (75mm,13mm, 13mm) length, width and height respectively, in which each (2) specimens were joined by soft liner with a 3-mm thickness (12), to finally reproduce (80) specimens which were grouped as: 40 control specimens without plasma treatment, 40 oxygen plasma treated specimens, each 40 specimens for each group was subdivided into 20 specimens with application of mollosil soft liner and 20 specimens with application of refit soft liner and then 20 specimens were subdivided into two groups (10 specimens for each type of soft liner) for the immersion in both the distilled water and denture cleanser. for tensile bond strength test the following procedures were done: 1. preparation of acrylic resin blocks: the high impact acrylic resin specimens were prepared by placing of 2 plastic mold with the dimension of (75mm,13mm,13mm) with stopper of depth a bout 3mm fig (2) for prepared shear bond strength in a silicone duplicating material to get silicone mold for curing of high impact acrylic resin specimens fig (3) (this material can withstand high degree of temperature till 3000c) then we mixed the high impact acrylic resin (powder and liquid) according to manufacturer instruction, about (21 g) of powder were mixed with (10 ml) of liquid after reaching dough stage we packed the high impact acrylic resin into the silicone mold which was inside the flask then flasking, curing in water path at (700c for hour and half an hour then at 1000c for half an hour) according to the manufacturer instruction then deflasking, finishing of the specimens was done with dental engine and carbide bur at low speed remove any excess material polishing was continued to remove any remaining small scratches by sandpaper of (120) grain size with continuous water cooling, all surface of the specimens were polished except the surface at which the soft liner were applied by using a lathe polishing machine with bristle brush and pumice. then the acrylic specimens were conditioned in distilled water at 370c for 48 hours according to adaspecification no.12 1999. after preparation of the specimens and before exposure to the plasma we put the specimens into an ultrasonic cleanser filled with distilled water to clean the specimens, after cleaning we let the specimens to dry on a clean towel ready for oxygen plasma exposure 2. preparation of the final shear bond strength test specimens: reline material application: according to the manufacturer instruction of both soft relining material (acrylic and silicon) soft liner material mixed them. the acrylic type soft liner come in powder and liquid with adhesive, first, put the adhesive and wait for 1min till it dry, then we mixed the powder and the liquid (one spoon of powder to 10 ml of liquid) in clean dry jar and put into the space between the two acrylic block by using spatula, the excess material was removed by using wax knife and a weight of 200g was put over the specimen(13) for figure (2): plastic molds for shear bond strength fig. 3: fabrication of silicone mold figure (1): plasma apparature j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 46 stability until complete setting of reline material was obtained (2min) after that, the specimens immersed in the two solutions (distilled water and denture cleaner). the silicone soft liner come into 2 past (base and catalyst) first the bonding agent was applied, and on a paper pad, we put the same amount of both base and catalyst and mixed till we obtain a homogenous mix (30 seconds) and then we put it in the space between two acrylic block by using spatula, any excess material was removed by wax knife and the specimen was put under weight of 200 g (13) for stability until complete setting of reline material was obtained (5min). after that, the specimens immersed in the two solutions, distilled water and denture cleaner for 30 days. preparation of denture cleanser solution: the present study used corega tablets denture cleanser, the composition as shown in the table (1) below. table (1): composition of corega tablets denture cleanser product compositions manufacture corega sodium carbonate sodium bicarbonate potassium caroate citric acid sodium carbonate peroxide sodium benzoate sodium lauryl sulfoacetate block drug company inc., usa the solution was prepared for corega tablets by dissolving one tablet in 200ml of warm water at 400c according to manufacturer instruction. after preparation of final specimens and preparation of denture cleanser (40 specimens) they are immediately immersed into the denture cleanser so that they are completely covered with this solution and left the specimens soaked in this solution for 30 days (5hour/day in denture cleanser (15) and then the specimens removed from the cleanser rinsed thoroughly for a few seconds under running water and soaked in distilled water(16). 1. testing of the specimens stored in distilled water: the specimens were immersed in distilled water at 37 0c for 30 days, then the sample were removed from distilled water and tested for shear bond strength by instron testing machine. the specimens were subjected to shear load with cross head speed (0.5mm/min) using load capacity (100 kg). calculated of shear bond strength for each specimen was measured as (the force at the debonding divided by a cross-section area of interface) according to the following formula: bond strength=f (n)/a (mm2) (astm. specification, d-638 m, 1986) f= force of failure (newton) a= surface area of cross-section (mm2). 2. testing of the specimens stored in denture cleanser: the specimens were immersed in denture cleanser for 30 days, then the sample were removed from distilled water (because the immersed period was for 5 hours at 400c first then on distilled water at 370c), then we remove the specimens from distilled water and leave them until dry on air in a clean towel, after drying we measured the shear bond strength by instron testing machine. figure (4): final specimens during setting of soft lining materials figure (5): corega tablets denture cleanser figure (6): instron machine for measuring shear bond strength j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 47 results shear bond strength test: mean and standard deviation values of shear bond strength (map) of resilient liner ( silicon and acrylic) soft liner to heat cure high impact acrylic with and without oxygen plasma treatment and after immersion in both distilled water and denture cleanser for 30 days and the comparison between the groups (with and without oxygen plasma treatment) are listed in table (2) the table (2) revealed that the highest mean value (0.213 n/mm2) for silicone soft liner after immersion in denture cleanser 30 days for the control group (without oxygen plasma treatment), while the lowest mean valuewas for acrylic soft liner (0,098 n/mm2) after immersion in distilled water for the control group (without oxygen plasma treatment). physical or topography surface analysis (atomic force microscopy or afm analysis): the surface topography/morphology of the untreated and oxygen plasma treated high impact acrylic specimens was analyzed and compared by atomic force microscopy. also, the specimen dimensions’ for (afm) analysis were, 75x13x13mm, as the same dimensions which were usedfor shear bond strength test.afm image show for the surface of high impact acrylic resin specimens (for both control and oxygen plasma treated)specimens, as in figure (7) which is for the control specimen (without oxygen plasma treatment) showed the unevenly distributed granular film in which the nanograin were large, with decrease average diameter and decreased in their number as compared with nanograin that found on the oxygen plasma treated specimen which have small, small average diameter and increased in their number and the distinct appearance of protuberance, crater like and peaks as in figure (8). table (2): descriptive statistics of the effect of plasma treatment on the shear bond strength of the two soft lining materials after immersion in different media (distilled water and denture cleanser) table 3: effect of immersion in different media on the s.b.s between high impact acrylic resin denture base and the soft lining materials in control and study groups table 4: effect of soft lining materials on the shear bond strength between high impact acrylic resin denture based and the soft lining materials after immersion in both media in control and study groups materials media groups descriptive statistics comparison n mean s.d. t-test d.f. p-value sig. silicon distilled water control 10 0.056 0.009 -15.364 18 0.000 hs study 10 0.130 0.012 denture cleaner control 10 0.213 0.016 14.913 18 0.000 hs study 10 0.125 0.009 acrylic distilled water control 10 0.098 0.011 -0.798 18 0.435 ns study 10 0.101 0.007 denture cleaner control 10 0.120 0.017 0.702 18 0.492 ns study 10 0.115 0.012 control (without oxygen plasma treatment) experimental (with oxygen plasma treatment) materials media t-test d.f. p-value sig. t-test d.f. p-value sig. silicone distilled water x denture cleanser -26.480 18 0.000 hs 1.025 18 0.319 ns acrylic distilled water x denture cleanser -3.451 18 0.003 hs -3.213 18 0.005 hs control (without oxygen plasma treatment) experimental (with oxygen plasma treatment) media materials t-test d.f. p-value sig. t-test d.f. p-value sig. distilled water siliconxacrylic -9.092 18 0.000 hs 6.363 18 0.000 hs denture cleaner siliconxacrylic 12.667 18 0.000 hs 2.001 18 0.061 ns j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 48 discussion the effect of plasma treatment on shear bond strength: based on the result obtained in the present study, as showed in table (2), oxygen plasma treatment increases the shear bond strength of both soft liner (acrylic and silicone), soft liner after immersion in distilled water for 30 days as compared with the control group (without oxygen plasma treatment) this can be attributed to etching process produce by oxygen plasma that led to enhance the surface roughness which increased the effective surface area of the high impact acrylic which led to high shear bond strength between soft liner and high impact acrylic resin, these results were in agreement with the finding of yasuda (17) where they found that increased in the tensile bond strength between heat cure acrylic resin and two types of soft liners (silicone, acrylic) by enhancement of roughening that led to more molecular intimated contact between plasma exposed polymer surface and applied soft liner and the decrease in the mean of the shear bond strength of the silicone and acrylic soft liner after immersion in denture cleanser for 30 days may be attributed to the water uptake by this material which was dependent on the water soluble components and (like the plasticizer)/or hydrophilicity of the matrix and after immersion in denture cleanser, this led to loss of these component and finally loss of bonding, this was in agree with mansoor (18) who found that after immersion of ufi gel (silicon-based cold cure) soft liner in citric acid denture cleanser showed a higher solubility value (higher loss of soluble components in citric acid) which in turn lead to more water uptake. the result revealed as shown in table (3) that the shear bond strength of mollosilsilicone soft liner of the study group after immersion in distilled water and denture cleanser for 30 days was a statistically increased (non significant differences) this may be due to the roughening effect of plasma surface treatment which enhanced the bond strength and this was in agreement with craig and gibbson (19) who reported that (the adhesive effect obtained with rough surface were approximately double those of smooth surfaces), while for the control group there was a statistically decreased (high significant differences) after immersed in distilled water for 30 days and this may be due to water uptake and led to loss of soluble component, this was in agreement with hachim (14) who found that there was a statistically decreased (significant differences) in the shear bond strength of cold cure silicone soft liner (ufi gel) after storage in distilled water for (1and 3 month), these results disagreed with craig (20) who suggested that storage in water did not affected the bonding strength of denture liners to acrylic denture base. these differences in results may be due to the use of high impact acrylic instead of heat cure acrylic (conventional) as well as due to the difference in the type storage solution and time of storage used in the present study. mollosilsilicone soft liner: there was a statistically decreased (nonsignificant differences) of the study group after immersion in denture cleanser for 30 days. this may be due to the chemical and physical properties of the denture base resin as well as the type of soft lining materials (silicone and acrylic) which have been led to loss of their component and loss of bonding, this was agreed with the study of mese (21) who reported that after comparison between water and denture cleanser figure (7): afm image for control (without oxygen plasma) high impact acrylic specimen: 3 dimensions image figure (8): afm image for oxygen plasma treated high impact acrylic specimen: 3 dimensions image. j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 49 (polident) immersion of both types of soft liners (acrylic and silicone) the bond strength was a statistically (non significant differences) and this may be due to the effect of difference in both adhesion properties of resilient lining material which in turn depended on physical properties, chemical properties, the type of bonding used and mode of polymerization of the soft lining material while for the control group there was a statistically increased (high significant differences) in the shear bond strength after immersion in denture cleanser for 30 days, this may be due to the fact that the chemical composition of it contained cross linking agent instead of plasticizer (like in acrylic soft liner) which led to less water uptake and became more stable when it immersed in water or other solution. the result was in agreement with segundo et,al.,(22) who found that (the denture cleanser solution (corega tablets) did not contain any chemical component that affects the dissolution of the tested materials (acrylic and silicone soft lining materials)). refitacrylic soft liner: there was a statistically increased (high significant differences) for the shear bond strength after immersion in distilled water for 30 days for the study group, and this can be attributed to the oxygen plasma etching process that led to increase the surface area and enhanced the bond by mechanical interlock. this result was in agreement with the finding of inagaki (23) who revealed that when the polymer was exposed to plasma of inorganic gases such as (oxygen, helium, argon, hydrogen and nitrogen) this led to etching reaction, radical generation and implantation of atoms. for the control group, there was a statistically decreased (high significant differences) after immersion in distilled water for 30 days, this was in agreement with madan and datta, graham et,al., and gracia et al (24-26) who reported that when acrylic soft lining material immersed in water, two processes are feasible: the leaching out of plasticizer, other soluble component into water and the polymer absorbs the water with time led to change in mechanical and physical properties of soft lining materials (loss of resiliency and change in viscoelastic properties) so they became hard, brittle and loss their bond strength properties. refit-acrylic soft liner: there was a statistically decreased high significant differences after immersion in denture cleanser for 30 days for the study group and this can be attributed to the effect of the denture cleanser on the shear bond strength that led to loss of soluble component and hardening of the material that led to loss of bonding, the result was in agreement with abdul-razaq et,al., (27) whose study revealed that there were a statistically decrease (high differences) in tensile bond strength values between the specimens which were stored in pepsi. this may be due to hydrolysis effect of (pepsi) on the tensile bond strength of soft lining material with the denture base which led to air entrapment at the bond interface. while for the control group, there was a statistically increased (high significant differences) after immersion in denture cleanser for 30 days and this can be attributed to the type of chemical composition and compatibility between the soft liners and denture cleanser. this was in agreement with garcia et,al.,(26) who reported that when acrylic soft lining material immersed in denture cleanser (pilodent and water), the bond strength showed a statistically increase (high significant differences). table (4) showed that the shear bond strength between the two types of soft liner after immersion in distilled for 30 days of the study group was a statistically increased (high significant differences). this may be attributed to the effect of chemical etching of plasma that led to an increase in surface roughness and because these materials were (cold-cured) mixed and loaded by hand and allowed to set by application of weight (200 g) leading to an increase in the flow of these material into these irregularities and improved the bond strength, this was in agreement also with polyzois (28) where he stated that rough surfaces of acrylic resin could give better bond strength than smooth surfaces. the shear bond strength was a statistically decreased (non significant differences) after immersion in denture cleanser for 30 days, this may be due to the differences in the chemical composition of the two soft lining material therefor they have different behaviors in denture cleanser, the result was in agreement with abdulrazaq (12) who found that there were a nonsignificant differences in the mean values of (hardness and shear bond strength) of mollosil and viscogel after immersion in disinfectant solutions (solo and chlorhexidine). although the materials used in the present study were not the same. the shear bond strength between the two types of soft liner after immersion in distilled for 30 days for the control group was a statistically decreased (high significant differences) as in table (4). j bagh college dentistry vol. 27(4), december 2015 the effect of restorative dentistry 50 the results were in agreement with the study of mese and guzle (29) who found that after immersion of both (silicone and acrylic) soft liner of both types (heat-cured and cold-cured) in water showed decreased significant difference in the mean of tensile bond strength and hardness. this may be attributed to the effect of humid environment that led to loss of soluble component and water uptake by the soft liners which led to deterioration of physical and functional properties like hardness and bond strength the result revealed in table (4) of the shear bond strength between the two types of materials was a statistically increased (high significant differences) after immersed in denture cleanser for 30 days. this may be attributed to the differences in the polymerization between the soft lining material and heat cure high impact acrylic and to the effect of denture cleanser on the shear bond strength this findings were in agree with kazanji and watkinson (30) who found that soft lining material can absorb water or loss soluble component based on their structure and the chemical solution in which were soaked. the effect of plasma treatment on physical surface morphology: the result as shown in figures (7,8) was agree with the finding of cvelbar (31), this difference in the appearance of the two specimens attributed to the etching process by oxygen plasma treatment causes an increase in surface area of polymer by removal of surface material and producing a rough surface (formation of pits and protuberance) and because of the process of etching and production of rough surface will contribute in more intimate contact between soft lining materials (acrylic and silicon) and high impact acrylic denture base which in turn resulting in further bonding strengthening. references 1. teraoka f, nakagawa m, takahashi j .adaptation of acrylic dentures reinforced with metal wire. j oral rehabil 2001; 28: 937–42. 2. matsukawa s, hayakawa t, nemoto k. development of high-6. toughness resin for dental application. dent mater 1994; 10: 343-6. 3. ellakwa ae, morsy ma, el-sheikh am. effect of aluminum oxide addition on the flexural strength and thermal diffusivity of heat-polymerized acrylic 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bagh college dentistry vol. 25(2), june 2013 evaluation the antioxidant oral and maxillofacial surgery and periodontics 119 evaluation the antioxidant effect of α-lfucose injection into rabbit periodontium chenar a. mohammad (1) khlood a. al-safi (2) bakhtiar m. ahmed (3) abstract background: α-l-fucose is a methyl pentose sugar similar to l-galactose except for the loss of alcohol group on carbon number 6. the objective of this study is to evaluate the biochemical and antioxidant effect of intracrevicular injection of fucose into rabbits periodontium, throughout measuring the levels of total protein (tp), total fucose (tf), protein bound fucose pbf) , malondialdehyde (mda) , and vitamin c in sera of fucose injected rabbit groups. ( materials and methods: the existing study was carried out on 55 male rabbits and were divided randomly into three groups ; first group was injected with 50µl of 150mm fucose solution into gingival sulcus ; second group was injected with 50 µl of normal saline ; while the third group was not received any injection ( normal group) .blood samples were collected from injected groups at time intervals of 1, 3 ,24 ,72, and 168 hours after injection, for measuring of serum tp, tf, , pbf , mda, and vitamin c and compared with normal group. results: the results showed a significant increase in the mean concentration of tf and pbf reaching its maximum value 3hrs after injection, then it decline until reached its normal value 168 hours after injection, whereas serum total protein increased significantly only 3 hours after injection. also serum mda level did not change after injection, while serum vitamin c increased immediately after fucose injection, even 72 hours after injection. conclusion: intracrevicular injection of α-lfucose has an observable effect on tf and pbf this may give an indication about its effect on periodontal tissue and has a role in the body defence against oxidative stress, throughout increasing the production of vitamin c. key words: total protein, total fucose , protein bound fucose , malondialdehyde ,vitamin c. (j bagh coll dentistry 2013; 25(2):119-124). introduction α-l-fucose is a six carbon deoxy–hexose (6deoxy-l-galactose) with a general formula of c6h12o5 1, and is important component of glycoproyein and glycolipid. in mammals, fucose-containing glycans have important roles in blood transfusion reactions, selecting-mediated leukocyte endothelial adhesion, host -microbe interactions and numerous oncogenic events, including signaling events by the notch receptor family 2. fucose glycoconjugates (glycoproteins and glycolipids) are an essential part of eliminating or reversing such disease processes as cancer, inflammation, and immunity 3. studies showed the importance of serum, saliva and gingival fluid fucose and its related parameters in the detection of oral disease, such as; gingivitis, periodontitis and oral cancers 4,5. a study suggested that serum glycoproteins components (fucose, sialic acid, hexose and hexosamine) were a useful index of inflammation 6 . (1)phd student, periodontology, college of dentistry, hawler medical university. (2)professor, periodontology, college of dentistry, baghdad university. (3)assistant professor, basic science, clinical and oral biochemistry , college of dentistry, hawler medical university, erbil, iraq other study revealed that α-l-fucose could be used as therapeutic agent for many diseases, throughout oral administration or intravenous injection. this might be due to the inhibiting and reversing effect of l-fucose on the disease process7 .studies also report that fucose had the ability to kill bacteria, controlling infection and modulate immune system and normalize immune function 8,9. materials and methods the study was carried out on 55 male white rabbits of the same species and nearly the same age (10-12 months) that weighed 1-1.5 kg. they were divided randomly into three main groups, first group was called fucose injected group which consisted of 25 rabbits and had been subdivided randomly into 5 subgroups ; b1,b2,b3,b4, and b5 . each subgroup included five rabbit that received intracrevicular injection of a single dose of 50µl ∕ kg of 150mm fucose into the mid –labial of the gingival sulcus of the lower right central incisor. then blood samples were collected by cardiac puncture10, after a specific time intervals of 1hrs (b1group), 3 hrs (b2group), 24hrs (b3group), 72 hrs (b4group), 168 hrs (b5 group) after fucose injection. the second group called normal saline injected group, consisted of 25rabbits, this group also subdivided randomly into 5 subgroups; c1, c2, c3, c4, and j bagh college dentistry vol. 25(2), june 2013 evaluation the antioxidant oral and maxillofacial surgery and periodontics 120 c5. each subgroup included 5 rabbit that received local injection of 50µl ∕ kg of normal saline into the same area as fucose group at time injected group. blood samples were collected from the hearts at the same intervals of 1 hrs (c1group), 3 hrs (c2 group), 24hrs (c3 group), 72hrs (c4group), 168 hrs (c5group) after saline injection. the third group called non-injected group (group a), which consisted of 5 rabbits, the rabbits of this group were not received any injection .blood samples were collected in the same way as in fucose and saline injected groups. the study was carried for: a. estimation of serum total protein (tp): serum total proteins for the rabbit groups were estimated, using biuret method 11 . bestimation of serum total fucose ( tf): serum tf was estimated according to the method of disch and shettels 12.the principle depends on the direct formation of a chromogen after addition of concentrated h2so4 and cysteine reagent into the tube containing the sample, and the color product measured at (390 and 430 nm).the difference in absorbance was directly proportional to α-l-fucose content of the sample. cestimation of serum protein bound fucose (pbf):serum pbf was also determined according to the method of disch and shettels12. the protein was precipitated by ethanol. the precipitate was resuspended in naoh to resolubilize the protein. a color product was formed when fucose, in strong acid medium, combined with cysteine hydrochloride. the color intensity was measured at 390nm and 430nm. d-determination of serum malondialdehyde (mda):serum mda was estimated by nwkmda01 assay, the nwk-mda01 assay was based on the reaction of mda with thiobarbituric acid ((tba);forming an mda-tba2 , a product that absorbed stronglyat532nm13. e -determination of serum vitamin c:serum vitamin c was determined using stanely method 14. the principle depends on ascorbic acid oxidased to form dehydroascorbic acid and diketogluonic acid ,which react with 2, 4 phenylhydrazine to form a derivative of 2,4dinitrophenylhydrazine, then this compound with concentrated h2so4 , gets rearrangement and forms a product that gives absorbance at520nm. 520nm. results 1. serum total protein (tp): table (1) shows that, there was an increase in the mean of tp after fucose injection, but this increase was significant only, 3 hours after injection ( b2 group) (p<0.05) . table (2) showed the tp values in serum of non injected group (group a) and normal saline injected subgroups; c1, c2, c3, c4, and c5 after time intervals of injection with saline solution. no significant changes in tp values were observed, indicating that intracrevicular injection of saline solution had no significant effect on serum tp levels (p>0.05). 2serum total fucose (tf) table (3) shows that, serum tf levels increased significantly after fucose injection, reaching optimum value, 3 hours after injection (group b2) as compared to the non-injected group, then it decline but still significantly high after 24, and 72hours of injection (group b3, and b4), then it returned to normal base line value, 168 hours (7days) after fucose injection (group b5) (p>0.05). table (4) shows the tf values in sera of noninjected group (a) and normal saline injected groups (c1, c2, c3, c4 and c5) after time intervals of local injection with normal saline solution. no significant changes in tf values were observed in sera of saline injected subgroups comparing with non-injected group(p>0.05). 3serum pbf table 5 shows that, pbf level increased significantly after injection reached optimum value, 3 hours after injection (groupb2), then it declined step by step, but still more than its value in noninjected group, finally it returned back to normal base line value, 168 hours after fucose injection (group b5). table (6) shows the pbf values in sera of non-injected group (group a) and normal saline subgroups after time intervals of intracrevicular injection with saline solution. no significant changes in pbf values were observed in sera of saline injected subgroups comparing with non-injected group ( p>0.05) . 4.serum malondialdehyde (mda): table (7and 8) shows that there were non significant differences in the mean level of mda between both fucose injected groups and normal saline injected subgroups as compared to noninjected group(p>0.05). 5. serum vitamin c: table (9) shows the mean, and standard deviation of serum vitamin c levels in noninjected group (group a) and fucose injected groups after time intervals of fucose injection. the results indicated that the mean serum levels of vitamin c in fucose injected groups increased highly after 1hour of injection, then it declined, but still higher than that of non-injected group. finally it returned to normal value , 168hours after injection ( p > 0.05) . table (10) shows non significant differences in the mean serum levels j bagh college dentistry vol. 25(2), june 2013 evaluation the antioxidant oral and maxillofacial surgery and periodontics 121 of vitamin c between normal saline injected subgroups and non-injected group (p>0.05). table 1: the mean, and standard deviation (sd)of serum total protein in rabbits of noninjected group and groups after time intervals of intracrevicular injection with 50µl ∕ kg of 150mm fucose in normal saline solution (p>0.05). rabbit groups n. of rabbits time intervals (hours) fucose & control ( tp gr/dl) mean ±sd p-value sig. a 5 control 5.29 1.42 b1 5 1hr 6.50 1.39 0.21 ns b2 5 3hrs 6.93 0.53 0.04 s b3 5 24hrs 6.56 1.42 0.19 ns b4 5 72hrs 5.91 0.86 0.42 ns b5 5 168 hrs 5.88 1.24 0.55 ns table 2: the mean, and standard deviation of serum total protein levels in rabbits of non-injected group and groups after time intervals of intracrevicular injection with 50µl ∕ kg of normal saline solution( p>0.05). rabbit groups n. of rabbits time intervals (hours) ns & control ( tp gr/dl) mean ±sd p-value sig. a 5 control 5.29 1.42 c1 5 1hr 6.42 0.94 0.18 ns c2 5 3hrs 5.74 2.66 0.74 ns c3 5 24hrs 4.91 1.03 0.64 ns c4 5 72hrs 5.72 0.51 0.54 ns c5 5 168 hrs 5.47 0.43 0.79 ns table 3:the mean, and standard deviation of serum total fucose in rabbits of noninjected group (a)and groups after time intervals of intracrevicular injection with 50 µl ∕ kg of 150 mm fucose in normal saline solution(p<0.05). rabbit groups n. of rabbits time intervals (hours) fucose&control( tfmg/dl) mean ±sd p-value sig. a 5 control 10.39 0.16 b1 5 1hr 13.85 2.32 0.01 s b2 5 3hrs 15.41 1.38 0.000 hs b3 5 24hrs 14.07 0.07 0.000 hs b4 5 72hrs 13.63 2.22 0.01 s b5 5 168 hrs 11.13 0.86 0.09 ns table 4:the mean , and standard deviation of serum total fucose in non-injected group (a)and groups after time intervals of sulcular injection of 50 µl ∕ kg saline (p>0.05). rabbit groups n. of rabbits time intervals (hours) ns &control(tfmg/dl) mean ±sd p-value sig. a 5 control 10.39 0.16 c1 5 1hr 10.85 0.60 0.14 ns c2 5 3hrs 10.75 1.34 0.57 ns c3 5 24hrs 10.59 2.70 0.87 ns c4 5 72hrs 10.56 3.30 0.91 ns c5 5 168 hrs 10.07 1.47 0.63 ns table 5: the mean, and standard deviation of serum protein bound fucose in noninjected group and groups after time intervals of sulcular injection with 50µl ∕ kg of 150mm fucose in normal saline solution (p>0.05). rabbit groups n. of rabbits time intervals (hours) fucose & control ( pbf mg/dl) mean ±sd p-value sig. a1 5 control 2.79 0.82 b1 5 1hr 6.16 2.43 0.01 s b2 5 3hrs 6.83 1.41 0.000 hs b3 5 24hrs 6.63 0.90 0.000 hs b4 5 72hrs 6.27 0.43 0.000 hs b4 5 168hrs 2.48 0.34 0.46 ns table 6: the mean , and standard deviation of serum pbf in rabbits of non-injected group (a) and groups after time intervals of intracrevicular injection with 50µl ∕ kg of normal saline solution.( p>0.05). rabbit groups n. of rabbits time intervals (hours) ns & control (pbf mg/dl) mean ±sd p-value sig. a 5 control 2.79 0.82 c1 5 1hr 2.78 0.54 0.98 ns c2 5 3hrs 2.76 0.30 0.93 ns c3 5 24hrs 2.75 0.31 0.92 ns c4 5 72hrs 2.75 0.61 0.93 ns c5 5 168 hrs 2.74 0.69 0.93 ns j bagh college dentistry vol. 25(2), june 2013 evaluation the antioxidant oral and maxillofacial surgery and periodontics 122 table 7: the mean, and standard deviation of serum malondialdehyde levels in rabbits of non-injected group and groups after time intervals of intracrevicular injection with 50µl ∕ kg of 150 mm of fucose solution( p>0.05). rabbit groups n. of rabbits time intervals (hours) fucose & control (mdanmol ∕ l) mean ±sd p-value sig. a 5 control 4.220 1.087 b1 5 1hr 4.560 1.328 0.669 ns b2 5 3hrs 4.340 1.571 0.892 ns b3 5 24hrs 4.160 0.929 0.928 ns b4 5 72hrs 4.340 0.723 0.842 ns b5 5 168 hrs 4.260 0.498 0.943 ns table 8: the mean, and standard deviation (sd)of serum malondialdehyde levels in rabbits of non-injected group and groups after time intervals of intracrevicular injection with 50µl ∕kg of normal saline solution( p>0.05). rabbit groups n. of rabbits time intervals (hours) ns & control (mdanmol ∕ l) mean ±sd p-value sig. a 5 control 4.220 1.087 c1 5 1hr 4.160 1.324 0.94 ns c2 5 3hrs 4.140 1.534 0.927 ns c3 5 24hrs 4.280 1.730 0.949 ns c4 5 72hrs 4.320 1.264 0.897 ns c5 5 168 hrs 4.240 1.108 0.978 ns table 9: the mean, and standard deviation of serum vitamin c levels in non-injected group and groups after time intervals of intracrevicular injection with 50µl ∕ kg of 150 mm fucose solution (p<0.05) . rabbit groups n. of rabbits time intervals (hours) fucose & control (vitamin c mg∕ 100 ml) mean ±sd p-value sig. a 5 control 0.192 0.022 b1 5 1hr 0.442 0.097 0.000 hs b2 5 3hrs 0.387 0.048 0.000 hs b3 5 24hrs 0.246 0.019 0.004 hs b4 5 72hrs 0.237 0.035 0.043 s b5 5 168 hrs 0.202 0.003 0.057 ns table 10: the mean, and standard deviation (sd) of serum vitamin c levels in rabbits of non-injected group and groups after time intervals of intracrevicular injection with 50µl ∕ kg of normal saline solution (p>0.05) . rabbit groups n. of rabbits time intervals (hours) fucose & control ( vitamin c mg∕ 100 ml) mean ±sd p-value sig. a 5 control 0.192 0.022 c1 5 1hr 0.218 0.016 0.076 ns c2 5 3hrs 0.217 0.047 0.314 ns c3 5 24hrs 0.206 0.002 0.210 ns c4 5 72hrs 0.203 0.001 0.319 ns c5 5 168 hrs 0.201 0.000 0.426 ns discussion 1 serum total protein (tp) : serum tp level significantly increased after 3 hours of fucose injection (b2 group), then the mean value declined with non significant changes and nearly returned to the normal value after 168 hours of injection .the result may be due to break down of tissue protein and glycoprotein which may be occured as a result of the inflammation induced by injection of foreign material into gingival tissue as well as the injury processes that induced by the introduce of needle 15. 2-serum total fucose (tf): in this study, the serum content of total fucose increased after intracrevicular injection of fucose solution into gingival sulcus. this increase may be due to the time that needed for fucose solution to be transferred from gingival sulcus into gingival connective tissue through the epithelial lining of sulcus , then it passes into the serum through blood vessels plexus that exist in gingival tissue. some amount of injected fucose can enter to the gingival tissue and can incorporate into glyconjugates ,throughout its conversion to the main substrate ( gdp-fucose) 16 , as indicated in the following reactions:fucose→fucose-1-p→gdpfucose→glycoprotein . it was published that ,if exogenous fucose is injected into animals, it is first conjugated intracellularly to form fucose -1phosphate followed by conversion into gdplfucose ,and finally, this nucleotide –sugar functions as a sugar donor in glycoprotein synthesis 17. it was reported that exogenous fucose administrated to animals is unlike the other monosaccharides, it is not converted into other sugars or substances of another nature but amounts can enter to the circulation and recovered from the urine17,18. 3serum protein bound fucose (pbf): from the results of serum pbf , one can conclude that intracrevicular injection of fucose can accelerate the biosynthesis and secretion of serum glycoprotein from gingival tissue . fucose injection j bagh college dentistry vol. 25(2), june 2013 evaluation the antioxidant oral and maxillofacial surgery and periodontics 123 also can induce fucosylation of newly synthesized glyconjugates in the tissue .so the maximum induction of fucosylation of newly synthesized glyconjugate and its secretion into extra-cellular fluid (serum glycoprotein) can reach maximum rate, 3 hours after fucose injection, then it declines step by step until reaches to its normal value ,168 hrs after injection. . the results of fucose injection and its effect on serum pbf level in this study are in line with the results obtained by 16, who injected a single dose of l-fucose-1-14 c in 0.9% sodium chloride solution intraperitoneally .they found that the incorporation of fucoseinto the proteins of serum and tissues was time dependent. their result showed that the value in serum reached highest activity , 3 hours after injection then declined step by step. they concluded that liver, small intestine, and serum were the most highly labeled (contained high labeled protein bound fucose) than the other tissue. although the liver is the major site of synthesis of serum glycoproteins, the appearance of proteinbound fucose in the serum of hepatectomized rats indicated that extrahepatic tissues contributed to the circulating glycoproteins. . researchers studied the metabolic fate of l-fucose-1-14c and serum glycoprotein labeled with 14c-fucose in rats after daily periods of parenteal or oral administration of these compounds. they found that the time of maximum serum protein bound fucose was 3 hours after injection19. so our results indicated that intracrevicular injection of fucose solution caused an increased in serum pbf levels for a long duration that reached 72 hours after injection. . 4.effect of fucose injection on serum mda and vitamin c. . . since it’s the first study to evaluate the antioxidant effect of local injection of fucose solution on healthy periodontium, throughout measuring serum vitamin c and mda. the results showed a non significant difference in serum mda between fucose injected groups and non-injected group (groupa ) ,this results indicated that oxidative stress parameter (mda) was not affected by fucose injection and remained normal ,while serum content of vitamin c was found to be affected by fucose injection and increased. thus fucose may has an indirect antioxidant effect, throughout increasing the blood level of vitamin c for a long duration, reached 72 hrs after injection. this increase may be due to the enhancement effect of fucose injection on the endogenous secretion of vitamin c which is a potent antioxidant in the body. whereas no change was observed in the basal levels of lipid peroxidation markers (mda) in both injected groups. for normal saline, the result showed that the endogenous secretion of both mda and vitamin c. was not affected by normal saline and remained normal . . since the profound oxidative stress that occurs following injury results in significant depletion of many endogenous antioxidants (vitamin c, e, selenium). evidence suggested that antioxidant supplementation reduce infectious complications and organ dysfunction following injury and hemorrhagic 20. vitamin c is a preferred antioxidant, denotes two electrons and the species formed after the loss of one electron is a free radical,semihydroascorbic acid or ascorbyl radical , but is relatively stable with a half life of 10‾5 seconds and is fairly unreactive .in simple terms, a reactive and possibly harmful free radical can interact with ascorbate , then reactive free radical is reduced ,and the ascorbyl radical formed in its place is less reactive. then upon loss of second electron, the compound formed is dehydroascorbic acid. once formed ascorbyl radical and dehydroascorbic acid can be returned back into ascorbic acid by at least three enzyme pathways as well as by reducing compound in biological system such as glutathione .the action of l-fucose and a fucose-rich oligosaccharide (frop-3) on skin explant cultures and fibroblast cell cultures, alone or together with three vitamins (a, c, e, often used in topical preparations) was studied. both l-fucose and frop-3 modulated the action of the two abovementioned vitamins in most experimental conditions used. the combined action of the three vitamins (all-trans retinol, ascorbate, alpha-tocopherol) with l-fucose and even more so with frop-3 can be considered as favorable for the modulation of the biosynthetic activity of fibroblasts 2 references 1. rosato fe, seltzer m, mullen j rosato e f.serum fucose in the diagnosis of breast cancer. can 1971; 28(6):1575-9. 2. bًeker dj and lowe jb .fucose :biosynthesis and biological function in mammals. glycobio 2003; 13(7): 41. 3. american international association of nutritional education. j nutrit educ for the world 2006; 23(5):6769. 4. miyoshi e, moriwaki k, nakagawa t. biological function of fucosylation in cancer biology. j bioch 2008;143(6):725-9. 5. shetty pk, pattabiraman tn. salivary glycoprotein as indicators of oral diseases. indi j clini bioch 2004;19(1) : 97-101. 6. kulkami`av, engnieer jj, sequira rd .glycoproteins as markers of inflammation in rheumatoid disorders. j postgrad med 1986; 32(2): 89-93. 7. miyoshi e, noda k, ko jh et al. over expression of α 1-6 fucosyltransferase in hepatoma cells suppresses intrahepatic metastasis after spleenic injection in athymic mice. canc res 1999a; 59: 2237-43. 8. etzioni a, tonetti m, vestweber d. fucose supplementation in leukocyte deficiency type ii. blood 2000; 95(11):3641. 9. lowe jb. glycosylation, immunity and.autoimmunity. cell.biol.2001; 104:809-812. 10. standardized operating procedure for rabbit immunization and blood collection 2011.buffalo university. j bagh college dentistry vol. 25(2), june 2013 evaluation the antioxidant oral and maxillofacial surgery and periodontics 124 11. tietz nw. text book of clinical chemistry. 3rd ed. ca curtis er, silveman lm, christensen rh 1995; pp. 523-4. 12. dische z, schettles lb. specific colors reactions of methyl pentoses and spectrophotometric micromethod for their determination 1948. 13. botsoglou na. rapid, sensitive and specific thiobarbituric acid method for measuring lipid peroxidation in animal tissue, food and feedstuff samples. j agric food chem 1994; 42:1931-7. 14. stanley t, david t, howerds s. selected method for the determination of ascorbic acid in animal cells, tissues and fluids”. method in enzymatology 1979; 69. 15. novaes ab, shapiro l, fillios lc, wood n. gingival fluid fucose to protein ratios as indicators of the severity of periodontal disease. j periodont 1980; 5(2):88-94. 16. bekesi jg and winzler rj. the metabolism of plasma glycoproteins. studies on the incorporation of lfucose-1-14c into tissue and serum in the normal rat. j bio chem 1967; 242 (17): 3873-9. 17. ma b, simala-grant jl,taylor de. fucosylation in prokaryotes and eukaryotes. glycobiology 2006; 16(12):158r-84r. 18. chuakov dm, lukayanov s, lukayanov ka. fluorescent proteins as a toolkit for in vivo imaging .trends biotechn 2005; 239 (12):605-13. 19. bocci v and winzler rj. metabolism of l-fucose-114c and of fucose glycoproteins in the rat. amer j phys 1996; 216: 1337-42. 20. collier br, giladi a, dossett la. impact of high-dose antioxidants on outcomes in acutely injured patients 2008; 32(4):384-8. 21. padayatty sj, katz a, wang y .vitamin c as an antioxidant: evaluation of its role in disease prevention. j amer colle nut 2003; 22 (1): 18–35. j bagh college dentistry vol. 28(4), december 2016 oral health status pedodontics, orthodontics and preventive dentistry 158 oral health status among group of patients with juvenile idiopathic arthritis according to duration of illness and age group in iraq zainab shallan, b.d.s. (a) nadia aftan al-rawi, b.d.s., m.sc., ph.d. (b) abstract background: juvenile idiopathic arthritis (jia) is a chronic disease of childhood. increased prevalence of periodontal disease and dental caries in juvenile idiopathic arthritis is due to difficulties in executing good oral hygiene. this study was conducted to assess oral health status in patients with juvenile idiopathic arthritis according to age and duration of illness. materials and methods: a research was conducted among juvenile idiopathic arthritis patients attending baghdad teaching hospital with different age and both gender, underwent a clinical evaluation of their dental and oral condition. diagnosis of dental caries was done according to the criteria of who (1997). dental plaque, gingival condition, calculus were assessed by pi/ gi/cal i following the criteria of silness and loe (1964), loe and silness (1963), ramfjord (1959) respectively . results: the study showed the percentage of caries-free patients was 6.17%. mean value of caries experience of primary teeth decreased with increasing age while caries experience of permanent teeth increased with increasing age, pl and cal indices mean values increased with increase age and difference was found significant. mean value of dmft decreased with the disease advance and significant difference was found. caries experience of permanent teeth increase with increase disease duration and difference was significant. conclusion: the systemic effect of disease may impact on oral health keywords: juvenile idiopathic arthritis, oral health. (j bagh coll dentistry 2016; 28(4):158-161) introduction juvenile idiopathic arthritis (jia), the most common chronic rheumatic disease in children (1) is comprises a group of distinct clinical entities of unknown etiology (2). this disease is characterized by joint inflammation with symptoms persisting for more than six weeks and onset before 16 years of age (3,4). oral manifestations associated with jia include increased dental caries, poor oral hygiene, and malocclusion. oral hygiene is poor across all age groups. poor oral hygiene may be results of upper-limb involvement, which may affect the patient’s ability do the fine-motor movements required for efficient, tooth brushing and flossing (5). patients with jia have a higher caries index and more decayed, filled, and missing teeth than age-matched groups as well as increased frequency of decayed teeth in all major age groups (6,7). studies have demonstrated that chronic arthritis in children has a multifaceted impact on their lives when they advance in age with arthritis (8-10). this impact can be on one end hard disease outcomes like organ failure or mortality and on the other end soft outcomes such as psychological status or quality of life (11). (a) m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (b) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. continuing active disease over prolonged periods results in significant levels of disability that adults with jia often encounter (12). on our knowledge there are no available iraqi studies that investigate oral health status in juvenile idiopathic arthritis and these patients need special attention about oral health, preventive program. for the previous reasons we decided to conduct this study to gain knowledge regarding oral health status as part of multidisciplinary treatment of this target group. materails and methods a research were conducted among patients attending baghdad teaching hospital, both gender, underwent a systematic clinical evaluation of their dental and oral condition. diagnosis and recording of dental caries was assessed according to the criteria described by who (13). plaque index of silness and loe (14) was used for plaque assessment, ramfjord index (15) was applied for the assessment of calculus, gingival index of loe and silness (16) was followed for recording gingival health condition and all these were assessed according to the age of the patients which were registered according to the last birthday (13) and duration of illness were taken from medical records to extract data and confirm the diagnosis. j bagh college dentistry vol. 28(4), december 2016 oral health status pedodontics, orthodontics and preventive dentistry 159 results results of this study showed that eighty one patients (forty six female and thirty five male) with mean age 17.59±9.63 with age range (2.5-48 years old and illness duration 8.45± 9.29 with range (2 month-38 year) with jia attending baghdad teaching hospital department of rheumatology in five months period. of the total sample, there were 6.17% of patients free of caries. disease in the primary dentition was looked at in the 2.5-15 years age group and in a 2.5-5 years subset. in this latter subset the subject group would only have primary teeth, whereas in the 2.5-15 years group the older subjects would also have some permanent teeth. caries experience of primary dentition (dmft) mean value decrease with increasing age as shown in table (1) while caries experience of permanent dentition (dmft) were examined in three age groups: 6–10 year, comprising patients with permanent teeth but who would also be expected to have some remaining primary teeth; 11-20 year, the young permanent dentition; and 21+ year, the mature permanent dentition. caries experience of permanent dentition increased with age and difference was found statistically highly significant as shown in table (2). pl and cal indices mean values increased with age and the difference was statistically significant table (3, 4). mean value of dt, ft and dmft decreased with the disease advance and statistically significant difference was found as shown in table (5). dmft increase with increase disease duration and difference was statistically significant table (6). table 1: caries experience of primary dentition (mean and standard deviation) among patient with juvenile idiopathic arthritis according to age caries experience age group (year) no. mean sd df t-test sig. dt 2.5-10 26 3.42 2.80 40.89 3.85 0.00** 11-15 27 0.96 1.70 total 53 2.17 2.60 mt 2.5-10 26 0.12 0.33 25 1.81 0.08 11-15 27 0.00 0.00 total 53 0.06 0.23 ft 2.5-10 26 0.23 0.51 25 2.29 0.03* 11-15 27 0.00 0.00 total 53 0.11 0.38 dmft 2.5-10 26 3.77 3.02 39.03 4.14 0.00** 11-15 27 0.96 1.70 total 53 2.34 2.80 not significant at p >0.05, *significant at p<0.05, **=highly significant at p<0.01 table 2: caries experience of permanent dentition (mean and standard deviation) among patient with juvenile idiopathic arthritis according to age caries experience age group (year) no. mean ±sd f-value sig. dt 6-10 19 1.00 1.41 10.00 0.00** 11-20 39 4.08 3.12 21+ 16 4.44 2.68 total 74 3.36 3.00 mt 6-10 19 0.00 0.00 14.30 0.000** 11-20 39 0.15 0.43 21+ 16 1.56 2.00 total 74 0.42 1.13 ft 2.5-10 19 0.16 0.69 6.46 0.003** 11-20 39 0.38 0.67 21+ 16 1.56 2.39 total 74 0.58 1.34 dmft 6-10 19 1.16 1.46 14.93 0.00** 11-20 39 4.62 3.35 21+ 16 7.56 5.14 total 74 4.36 4.09 **=highly significant at p<0.01 j bagh college dentistry vol. 28(4), december 2016 oral health status pedodontics, orthodontics and preventive dentistry 160 table 3: plaque index (mean and standard deviation) among patients with juvenile idiopathic arthritis according to age variables age groups no. mean ±sd anova f-value sig pl i 2.5-10 26 0.83 0.29 5.01 0.009** 11-20 39 1.05 0.23 21+ 16 1.06 0.4 total 81 0.98 0.31 table 4: calculus index (mean and standard deviation) among patients with juvenile idiopathic arthritis according to age variable age group (year) no. mean ±sd median mean rank chi-square sig. cal i 2.5-10 26 0.00 0.02 0.00 32.81 10.98 0.004** 11-20 39 0.08 0.27 0.00 42.46 21+ 16 0.17 0.30 0.00 50.75 total 81 0.07 0.24 0.00 ----- df=2, **=highly significant at p<0.01 table 5: caries experience of primary dentition (mean and standard deviation) among patient with juvenile idiopathic arthritis according to duration of illness caries experience duration of illness (year) no. mean ±sd t-test t-value df sig. dt <= 6.00 30 2.47 2.72 2.46 24.4 0.02* 6.01+ 23 0.90 1.52 mt <= 6.00 30 0.07 0.26 0.85 51 0.40# 6.01+ 23 0.00 0.00 ft <= 6.00 30 0.14 0.41 2.22 42 0.03* 6.01+ 23 0.00 0.00 dmft <= 6.00 30 2.67 2.93 2.69 26.9 0.01* 6.01+ 23 0.90 1.52 #=not significant at p >0.05, *significant at p<0.05 table 6: caries experience of permanent dentition (mean and standard deviation) among patient with juvenile idiopathic arthritis according to duration of illness caries experience duration of illness mean ±sd f-value p-value dt <=10 2.81 2.88 3.52 0.04* 11-20 4.25 2.86 21+ 5.20 3.08 mt <=10 0.12 0.38 27.38 0.000** 11-20 0.17 0.58 21+ 2.30 2.16 ft <=10 0.35 0.71 8.99 0.000** 11-20 0.33 0.65 21+ 2.10 2.88 dmft <=10 3.27 3.21 13.66 0.000** 11-20 4.75 3.11 21+ 9.60 5.30 * significant at p<0.05, **=highly significant at p<0.01. discussion unfortunately this is the first iraqi study of oral health status among jia. in the present study prevalence of dental caries was 93.83%. oral health can be indirectly affected by jia this may be attributed to a combination of etiological factors, including difficulties in executing good oral hygiene, unfavorable dietary practices, and side effects from the long-term administration of medication (17). on our knowledge no previous study concerning oral health assessment of juvenile idiopathic arthritis according age or duration of illness to compare with. mean value of caries j bagh college dentistry vol. 28(4), december 2016 oral health status pedodontics, orthodontics and preventive dentistry 161 experience of primary dentition (dmft) was decreased with increase age and all caries experience fraction of primary dentition decrease with disease advance. this finding is in agreement with al-haddad et al. (18); this result may be attributed to transition of primary to mixed dentition. the opposite was true for permanent dentition, mean value of caries experience of permanent dentition (dmft) were increased with increase age groups. this comparison according dental caries with ageing is found in several iraqi studies in addition to present study despite of juvenile idiopathic arthritis. the results of these iraqi studies showed that caries prevalence increased with age (19,20) also in iraqi a study of oral health of systemic lupus erythematosus (sle) patients there was highly significant positive correlation between age of sle patients and dmft (21). these results are attributed to the irreversibility of caries process and accumulative nature of the disease on the one hand, and the paucity of planned preventive programmers in iraq. in this study scores of plaque/gingival/calculus indices increased with increasing age. increasing dental plaque with age reported by many previous studies that could be attributed to in young age no detectable loss of the bone or connective tissue attachment which usually start late in life in most people and observed also among jia patients and may increase in severity with age advancing (8,22), or effect of disease and medication were all elements that apparently contributed to impairment of periodontal health condition (6) also the relation between dental caries and oral cleanliness, especially dental plaque was recorded by other studies (23, 24). references 1. ravelli a, martini a. juvenile idiopathic arthritis. lancet 2007; 369: 767–78. 2. ringold s, thapa m, shaw ea, wallace ca. heterotopic ossification of the temporomandibular joint in juvenile idiopathic arthritis. j rheumatol 2011; 38(7):1423-8. 3. lien g, flatø b, haugen m, vinje o, sørskaar d, dale k et al. frequency of osteopenia in adolescents with early-onset juvenile idiopathic arthritis: a longterm outcome study of one hundred five patients. arthritis rheum 2003; 48(8): 2214-23. 4. fjeld mg, arvidsson lz, smith hj, flatø b, ogaard b, larheim ta. relationship between disease course in the temporomandibular joints and mandibular growth rotation in patients with juvenile idiopathic arthritis followed from childhood to adulthood. pediatr rheumatol online 2010; 8: 13. 5. feres de melo ar, ferreira de souza a, de oliveira perestrelo b, leite mf. clinical oral and salivary parameters of children with juvenile idiopathic arthritis. oral surg oral med oral pathol oral radiol 2014; 117(1): 75-80. 6. walton ag, welbury rr, thomason jm, foster he. oral health and juvenile idiopathic arthritis: a review. rheumatology (oxford) 2000; 39 (5): 550–5.13. 7. welbury rr, thomason jm, fitzgerald jl, steen in, marshall nj, foster he. increased prevalence of dental caries and poor oral hygiene in juvenile idiopathic arthritis. rheumatology (oxford) 2003; 42(12):1445–51. 8. ostensen m, almberg k, koksvik hs. sex, reproduction, and gynecological disease in young adults with a history of juvenile chronic arthritis. j rheumatol 2000; 27: 1783–7. 9. zak m, pedersen fk. juvenile chronic arthritis into adulthood: a long-term follow-up study. rheumatol (oxford) 2000; 39: 198–20. 10. french af, mason t, nelson am, o′fallon wm, gabriel se. increased mortality in adults with a history of juvenile rheumatoid arthritis: a populationbased study. arthritis rheum 2001; 44: 523–7. 11. fransen j, van riel p. outcome measures in inflammatory rheumatic diseases. arthritis research therapy 2009; 11: 244. 12. packham jc, hall ma. long-term follow-up of 246 adults with juvenile idiopathic arthritis: functional outcome. rheumatology 2002; 41: 1428-35 13. who. oral health surveys basic methods. 4th ed. world health organization. geneva, switzerland 1997. 14. silness j, loe h. periodontal disease in pregnancy ii. acta odontol scand 1964; 22: 747-59. 15. ramfjord sp. indices for prevalence and incidence of periodontal disease. j perio 1959; 30:51-9. 16. loe h, silness j. periodontal disease in pregnancy i. acta odontol scand 1963; 21: 533-51. 17. synodinos p, polyzois i. oral health and orthodontic considerations in children with juvenile idiopathic arthritis: review of the literature and report of a case. j ir dent assoc 2008; 54(1):29-36. 18. al-haddad ka, al-hebshi nn, al-akhali ms. oral health status and treatment needs among school children in sana’a city. yemen. int j dent hygiene 2010; 8: 80–5. 19. al–farhan s. aspects of dental health in iraq. a master thesis, university of dundee, 1976. 20. khamrco ty, salman fd. a comparative study in dental caries prevalence between schools with and without systemic oral health care service in mosul city center. iraqi dent j 2000; 26: 207-16. 21. ali n. oral manifestations, oral health status and saliva composition changes in a sample of iraqi systemic lupus erythematosus patients. a master thesis, college of dentistry, university of baghdad, 2006. 22. rao a. principles and practice of pedodontics. 2nd ed. new delhi: jaypee brothers medical publishers; 2008. 23. alm a, wendt lk, koch g, birkhed d. oral hygiene and parent-related factors during early childhood in relation to a proximal caries at 15 years of age. caries res 2008; 42(1): 28-36. 24. mohamed z. dental caries and treatment needs among 16-18 years old high school girls, in relation to oral cleanliness, parent's education and nutritional status, in al-mussayb city/ babylon governorate/ iraq. a master thesis, college of dentistry, university of baghdad, 2014. j bagh college dentistry vol. 28(4), december 2016 oral health status pedodontics, orthodontics and preventive dentistry 162 laser 2effect of the co 7201 march ),1(9vol. 2 h college dentistry j bag restorative dentistry 20 effect of the co2 laser as surface treatment on the bond strength of heat cured soft liner to the high impact acrylic denture base material hawraa khalid aziz, b.d.s, m.sc. (1) absrtact background: soft liner material is become important in dental prosthetic treatment. they are applied to the surface of the dentures to achieve more equal force distribution , reduce localized pressure and improve denture retention by engaging undercut . so the aim of the study is to evaluate the effect of different surface treatment by air-abrasion al2o3 and laser treatment with co2 laser on improving the shear bond strength of the denture liner to acrylic denture base material . materials and methods: the 30 specimens of heat cured acrylic denture base material (high impact acrylic )and heat cured soft liner (vertex ,nether lands )were prepared for this study .they were designed and divided according to type of the surface treatment 10 specimens for each group and as follows :group i without any treatment (control group ), group ii was treated with air-abrasion (al2o3). while group iii was treated with co2 laser which has continuous pulses with wave length(10.6) micro-meter for (15) seconds . results: the results revealed that lowest mean values in shear bond strength the specimens treated with al2o3 (0.498 n/mm2)and control group (0.569 n/mm2)and the highest mean values for the specimens treated with co2 laser (0.648 n/mm2) . conclusion: within the limitation of this study ,co2 laser surface treatment of the heat cure acrylic denture resin with soft liner material resulted in highly significantly increased in shear bond strength values than control and al2o3 . gh coll dentistry 2017; (j ba shear bond strength . ,ner material ,heat cure acrylicsoft li, 3o2al laser , 2co :skey word 29(1):20-26) introduction polymethyl methacrylate (pmma) polymers have been referred as conventional base materials and one of the most widely used denture base material with numerous advantages(1). in addition to the denture lining material have become important in dental prosthetic treatment because they are applied to the surface of the dentures to achieve more equal force distribution, reduce localized pressure, and improve denture retention by engaging undercuts(2). therefore, more laboratory time and extra costs are needed to construct dentures with permanent lining material related to the equipment and materials used, so an adequate bond between the denture base and lining material is necessary(3).the adhesion to polymeric materials usually requires some surface pretreatments to improve wett ability characteristics of these materials(4). several studies have investigated different methods to improve bond strength between liners and acrylic denture base material ,some these studies investigated the effect of roughening by airborne –particle abrasion on the bond strength of the soft liner to acrylic resins (5) (1) assistant professor, dental technologies department, college of health and medical technology . other studies were investigated the use of chemicals, including acrylic resin monomers(6) and their combination on the bond strength of soft liners with denture resins(7). however controversial results have been reported. despite the studies reporting that an improvement of interface strength was achieved by making the surface denture base roughness prior to the application of lining material(4),others have not shown any negative effect on the roughening process of the bonding two materials(8). progress in laser technology has show a quick adoption for being used by many in the field of dentistry due to the development of the first working laser by maiman in 1960(9).recently, laser has been found to effective in alteration the surface of materials(4). in spite of the high frequency of denture fractures, little information is available about the effects of surface treatments on the repaired prostheses. therefore this study was designed to evaluate the effect of various surface treatments: air-abrasion with al2o3 particles and co2 laser surface treatment on improving the shear bond strength of heatcured soft lining material to the heat-cured acrylic resin denture base material. laser 2effect of the co 7201 march ),1(9vol. 2 h college dentistry j bag restorative dentistry 21 materials and methods the 30 specimens were prepared from heat cured denture base resin for this study. the specimens were divided into 3 groups according to the type of surface treatment (10 specimens for each group): group i: the specimens without any treatment (control) group ii: the specimens with sand blast with al2o3 (250 µm). group iii: the specimens with co2 laser treatment. each specimen consists of two heat cured acrylic blocks made from high impact acrylic (vertex, vertex-dental, netherlands) and intermediate soft liner material (vertex™ soft, netherlands) (figure 1). each acrylic block prepared with dimension shown in (figure 2). block of acrylic are placed one above the other leaving a space between them of dimension (25.4 mm 25.4mm 3 mm length, width and depth respectively). the thickness of the handle of acrylic of specimen was 13m (10). specimens preparation: the mould prepared by placement the pattern, that was coated with separating medium , into the lower half of the flask that was filled with the stone mixture after setting of the stoned, the stone and patterns were coated with separating medium and the upper half of the flask was positioned on the top of the lower half of the flask and filled with stone. the flask left to set. after an hour the flask was opened and the standard specimen was drawn out. the heat cure acrylic specimen made by mixing of the acrylic powder and liquid according to the manufacturer's instruction. p/l ratio(22g of powder / 10 ml of the liquid).the packing of heat cure acrylic was performed while the acrylic was in dough stage, as recommended by ada specification no.12 (1999)(11). the acrylic resin was removed from its mixing vessel and rolled; it was packed into the mould which previously has been coated with separating medium. the upper half of the flask was positioned in its place, then the flask was placed under hydraulic press with slow application of pressure to allow even flow of acrylic dough, then the flask was opened and by the use of a sharp knife the excess acrylic material was removed then the flask was tightly closed and clamped for curing .the curing of the heat cure acrylic according to the manufacturing instruction the flask immersed into cold water and then increased the temperature to 70ºc for 60 minutes. after that the temperature was increased to reach 100ºc for the next 60 minutes. the total polymerization time took 2 hours. then after cooling the flask was opened and the acrylic specimen was removed. the specimen was finished by removing all the accesses and flashes of acrylic specimens with an acrylic bur and stone bur followed by using sand paper with continuous water cooling. polishing was accomplished for all the surfaces of the acrylic specimen except the surface that faces the reline material by using bristle brush and pumice with lathe polishing machine (12). after which the acrylic specimen were measured using digital verneir (with an accuracy of 0.01) to end up with approximately dimensions (figure 3). then the acrylic specimens were conditioned in distilled water at 37ºc for 24 hours according to ada specification no.12 (1999).any porous specimen was discarded form the specimens that collected for the purpose of the study. figure 1 : heat cure acrylic material and soft liner figure 2: dimension of shear bond strength specimen figure 3: an acrylic block of the shear bond strength specimen. laser 2effect of the co 7201 march ),1(9vol. 2 h college dentistry j bag restorative dentistry 22 the surface treatment: the specimens were treated by co2 laser to ensure an equal distribution of the co2 laser treatment on the entire surface bonding area of each acrylic block and to standardize the laser treatment for all acrylic blocks a method was created as follow: an aluminum plate was cut (equal to dimensions of the acrylic block bonding surface area). then the aluminum plate was perforated with a special turning machine. this has the ability to drill small perforations that are equal in diameter and equal in distance from each other. the perforations diameter was of 2mm which is suitable for the laser to pass through them. 56mm distance was chosen between each two perforations (the smallest distance that machine can provide and under control without distorting the aluminum plate) (figure 4). figure 4: the aluminum plate for standardization of co2 laser treatment. the laser device (co2 laser, china )(figure 5)is the therapy laser, which is a solid state pulsed co2 laser emitting radiation at wavelength of 10.6 nm in the infrared region of the electromagnetic spectrum, and classified as a class iv laser according to the (ansi) classification and is supplied with its protective eye-wears. a fixed distance was created by stabilizing the exit window of the laser hand piece and the aluminum plate. the distance chosen for this purpose is (63 mm) according to the manufacturer instruction of co2 laser device for each hole and standard distance in laser application for each acrylic blocks. the laser treatment application was made under supervision of a laser specialist at the laser institute in baghdad university. after wearing eye glass for protection, the metal plate was put on the bonding surface of the acrylic block and the laser treatment was carried on by holding the laser hand piece vertically and at a fixed distance from the aluminum plate the exposure time was (15 seconds) for each hole in the metal plate (figure 6) (13). laser 2figure 5 : the co figure 6:the surface treated acrylic specimens with co2 laser the acrylic blocks was stored in distilled water for 24 h and ready for soft liner application (12). the specimens for al2o3 treatment were sand blast by using laboratory air abrasive blaster with al2o3 at air pressure of 4bars for one min. the specimens were held with special design fixture for standardization of distance between the specimen surface and nozzle of device 20mm(14) . after complete dryness of the acrylic specimens from distilled water. the soft liner was applied. the vertex soft lining material is supplied as powder& liquid, the material was placed into the mould, according to manufacturer's instruction, the mould was pressed with the hydraulic press for 10 minute then the flask was removed; put it into the clamp and then into thermostatically controlled water bath to polymerize, cold water heated slowly up to 100ºc for 0ne and half hours, then the clamp was removed; allowed to cool slowly before opening it; after opening the excess was cut with sharp knife then the specimen was removed from the mould . shear bond strength testing procedure: universal testing machine to test shear bond strength was used. the specimen was fixed to the machine using suitable clamps and subjected to 1000 n load at cross heat speed 1mm /min. until failure was occurred(15) (figure 7). the maximum force at failure of the specimen was recorded in newton in order to calculate the shear bond laser 25 : the co figure laser 2effect of the co 7201 march ),1(9vol. 2 h college dentistry j bag restorative dentistry 23 strength value for each specimen according the following formula: sbs=f/sa (astm spec.d-638m,1986) (16) sbs: shear bond strength (n/mm2) f: force of failure (n) sa: surface area of bonded site (mm2) statistical analysis the data was statistically analyzed with the computer program statistical package for social sciences (spss) version 21.0 for windows. the means and standard deviations were obtained. also, the one-way analysis of variance (anova), and multiple comparison tests utilizing the least significant difference test (lsd) were used for comparison of the effect of different surface treatment on the shear bond strength of heat cured acrylic specimens. a 95% confidence levels were used. results descriptive statistic of the results of shear bond strength values of the heat-cured soft liner with different surface treatment showed lowest figure 7: (a) universal instron machine (b) shear bond strength specimen during the test mean values for the specimens treated with al2o3 and the highest mean values for the specimens treated with co2 laser as shown in (table 1), and (figure 8). effect of the different surface treatment: in comparison of means values of the shear bond strength of the soft liner to the heat cured acrylic the anova-test was showed there were highly significant different between the tested groups as shown in (table 2). the lsd test between groups of shear bond strength test showed there was reduced significantly in the shear bond strength between the control group and specimens treated with al2o3 and a highly significant increased between the control group and specimens treated with co2 laser, as well as there was a highly significant difference between groups of treatment with al2o3 and co2 laser as shown in (table 3). table 1: descriptive of shear bond strength value. figure 8: the shear bond strength of the soft liner in all groups. mean sd se min. max. group i (control) 0.569 0.03071 0.00972 0.53 0.61 group ii (al2o3 ) 0.498 0.02251 0.00712 0.47 0.53 group iii (laser ) 0.648 0.09496 0.03005 0.53 0.78 a b laser 2effect of the co 7201 march ),1(9vol. 2 h college dentistry j bag restorative dentistry 24 table 2: anova of shear bond strength between groups of the soft liner according to different surface treatment. sum of squares df mean square f-test p-value between groups 0.113 2 0.056 16.136 0.000 within groups 0.094 27 0.003 total 0.207 29 *p<0.01 high significant table 3: lsd test between the groups of different surface treatment. mean difference p-value sig group i (control) & group ii (al2o3 ) 0.071 0.012 s * group i (control) & group iii (co2laser ) 0.079 0.006 hs ** group ii (al2o3) & group iii (co2laser ) 0.150 0.000 hs ** *p<0.05 significant ** p<0.01 high significant discussion only few studies have been conducted on the laser treatment of acrylic resin surfaces. lasing had been used to alter the surface of the pmma with the intention of providing increased surface area and mechanical locks. this in turn should benefit the bond sites resulting in a stronger bond(17). in general laser can provide an easy, safe, clean and time saving surface treatment that results in suitable surface pits and roughness which in turn increase soft liner bonding. shear bond strength are suitable for examining the bond strength of soft liner to acrylic, as the masticatory forces in the oral cavity are approximately similar to tear and shear forces rather than tensile forces (18). several problems were associated with the use of resilient denture liners, including bond failure between the liner and denture base, porosity of the resilient lining material, and loss of softness of lining material, colonization by candida albicans in addition to poor tear strength, although limitations exist in the areas of clean ability, hardness, volumetric change due to water absorption, and abrasion resistance, never the less bonding properties of the resilient lining material should be evaluated throughout one of the available several investigation shear, tensile, peel bond strength tests(2,19) . for the effect of different surface treatment on the shear bond the results of this study showed there were highly significant differences between the control group and different surface treatment with al2o3 and co2 laser treatment.in the present study, it was found that sandblasting of the pmma surface with al2o3 before application of soft liner resulted in a significant decrease in the bond strength when compared with control group this result agreed with amin et al (20) ,jacobsen et al. (17), and akin et al.(21) they reported that roughening the acrylic resin base by sandblasting before applying a lining material had a weakening effect on the bond. also agreed with another study that was showed the surface roughness was reduced the shear bond strength(22),but this result was contradicted those of usumez et al.(4) who found that alumina abrasion of the pmma before resilient-material application resulted in higher mean bond strength than those of control specimens. this could be attributed to the micro-pitting produced an elevation and depression at the surface of denture base material so the peaks of elevation act as a stress points to weaken the bond interface, as well as the rough surface decreased the surface laser 2effect of the co 7201 march ),1(9vol. 2 h college dentistry j bag restorative dentistry 25 tension which consequently affects the interface adhesion(22). for the comparison of surface treatment with co2 laser with control the results of this study showed there were highly significant increase in the shear bond strength. this could have been explained as follows: the impact of the high energy pulse of co2 laser may had caused an instant vaporization of water from the heat cured acrylic resin and this could in turn result in a massive volumetric expansion. this expansion in turn could have caused the surrounding material to ablate and thus increasing the surface area of the treated acrylic through producing surface roughness(23).therefore, soft-lining materials penetrate into the irregularities or pits produced by the co2 laser and increase the strength of the bond (21). so theoretically, both manipulations (increased surface area and mechanical locks) should benefit the bond site and result in stronger bonds (17). another cause could be attributed to the fact that the laser surface treatment of the heat cure acrylic resin did not affect or change the chemical bonding of active sites of acrylic based soft liner surface(24). this agreed with alathel and jagger in (1996)(18), polyzois and frangou in (2001)(25), and mese et al. in (2005)(26) they explained that a chemical bond had been formed between the acrylic based soft liner and pmma denture base polymer by a similar chemical composition. therefore, the surface of heat cured acrylic that was treated with the laser application could have resulted in irregularities with a lots of pits on the surface of the denture base resin, this in turn could have led to a conclusion that a soft lining material can penetrate into the irregularities and pits produced by co2 laser so that increase the strength of the bond. for the comparison of the effect of surface treatment with al2o3 and co2 laser groups the results showed there was highly significant difference between the co2 laser group in comparison to al2o3 group this could be attributed to that the size of irregularities created by the sandblasting medium may be insufficient to allow flow of the resilient lining material into them (17) in comparison to the size of the irregularities or pits produced by the co2 laser was quite sufficient to allow the flow of the soft liner, here the viscosity of the acrylic based soft liner could have enabled it to penetrate into the regularities of the bonding surface. this could be proved theoretically by the fact that the penetration coefficient is inversely proportioned to the viscosity(24). with the limitation of this study, we concluded there was significantly highly increased in the shear bond strength values for the specimens treated with co2 laser and lowest mean values that treated with al2o3 when compared with the control group. refernces 1. anusavice kj. philips science of dental materials. 11 edition, st. louis saunders company; 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26(4):28-31. 23. delfino cs, souza-zaroni wc, corona sa, palmadibb rg. micro tensile bond strength of composite resin to human enamel prepared using erbium: yttrium aluminum garnet laser. j biomed mater res a 2007; 80(2):475–479. 24. rasheed sk. the effect of er:yag laser surface treatment on shear bond strength and some mechanical properties of heat cure acrylic denture base material bonded to chair side soft lining material. a master thesis, department of prosthetic dentistry ,college of dentistry of university baghdad ,2014. 25. polyzois gl, frangou mj. influence of curing method ,sealer and water storage on the hardness of soft lining material over time. j prosthet dent 2001;10:42-45. 26. mese a, guzal kg, uysal e. effect of storage duration on tensile bond strength of acrylic or silicon based soft liner processed denture base polymer. acta odontol scand 2005;63:31-35. j bagh college dentistry vol. 30(4), december 2018 the impact of 45 the impact of an oral health education (ohe) program by teachers and mothers on adolescents' oral health sally talib da'aj, b.d.s.(1) zainab a. aldahan, b.d.s., m.sc.(2) absrtact background: adolescence is one of the most dynamic stages of human development. however, oral health is an integral part of public health, significantly impacts on the quality of life. ohe program is an important issue that should be given to them. the aim of this study was to evaluate oral health outcomes on adolescents' oral health by teachers and mothers materials and methods: the study was carried out in seven schools of diyala baquba city. this 14-weeks duration study assessed the effectiveness of school ohe program on oral hygiene status, gingival health, and halitosis assessment of 80, 12 year-old, both genders of school adolescents. from the selected schools, one group was supervised by the teachers and the other was supervised by the mothers. general and oral health assessments were evaluated using a questionnaire. a three days training workshop was organized for the teachers and mothers. oral hygiene, gingival health, and halitosis assessment were assessed using plaque indices, gingival indices and halitosis scores respectively. the resulting data were statistically analyzed using spss version 20. results: plaque, gingival and halitosis scores reductions were highly significant. results recorded gingival index, and halitosis scores were lower among the teacher-led group compared to the mother-led group. statistically, high significant differences were found (p< 0.01).but there is no significant differences were noticed between the groups for plaque index (p>0.05). conclusions: the ohe program was effective in teacher-led group than mother-led group in improving oral hygiene status, gingival health and halitosis scores of adolescents. keywords: adolescence, halitosis, mother-led, oral health education, oral hygiene status, teacher-led. (received: 3/11/2018; accepted: 28/11/2018) introduction the mouth is a mirror of health and disease that partly occurs in the rest body because all oral examinations can distinguish signs of several general health problems, like nutritional deficiencies and systemic diseases. as well, there is increasing evidence that oral health complications not only reflect general health conditions but also getting worse and even initiating them (1). since the mouth is part of the body, a child's risk of oral disease cannot be separated from responsibility of the disease in general (2). likewise, a child's risk of general illness and dental disease in particular cannot be isolated from family and community disease risk. thus, any realistic model of children's oral health outcomes should include a multilevel perception (3). oral health is essential to overall health, health education is an important approach in the process of achievement of behaviours that important location for promoting health ,as they reach over billion children worldwide and promote and maintain health (4). school provide an wellbeing and quality of life (4). general health which affected by some behaviours such as use of tobacco, excessive alcohol use and poor dietary choices are also associated with poor oral health outcomes. the appearance of this connection between oral health and general health and risk factors supports that the oral health care as an essential component of health programs and policies (5). untreated oral diseases in children commonly lead to serious general health problems, significant pain, and interference with eating and lost school time (6, 7). numerous dental problems in children and adolescents have been negatively related with psychosocial well-being. dental pain affects emotional stability of the children and registration in social activities such as preventing the children from engaging in playing (8). , through them, the school staff, families and the community as a whole (9). the ohe can be effective in increasing knowledge in the short term and to some extent, behaviour such as tooth brushing and healthy eating (10). for all of the above and in order to increase the knowledge about the oral health, this study was designed. (2) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (1) ministry of health, baghdad, iraq j bagh college dentistry vol. 30(4), december 2018 the impact of 44 materials and methods study population this study was designed with 14-weeks intervention trial involving a representative sample of 12 years old adolescents of seven primary schools in diyala baquba city. the sample involved forty adolescents as a teacher led group and forty as a mother-led group. ethical aspects the permission to carry out the study was obtained from diyala educational directorate and written consent was obtained from parents of the adolescents. theoretical model of the study data collection before implementation of the ohe program the data included the children’s clinical dental examinations at baseline, as well as a selfadministered questionnaire for the adolescents at baseline. questionnaires a self-designed format was designed to get general information regarding their general and oral health. the questionnaires were completed by the parents in their home. clinical examination the children were examined in the classroom during school time and were seated on a portable chair. portable lamp source for artificial illumination was used. a researcher recorded the clinical data on prepared data sheets. eight clinical oral examinations were carried out by the researcher to evaluate the ohe program including:-baseline examination carried out before conduction of the ohe program, and seven examinations carried out each two weeks after the implementation of the program. baseline plaque index (11), calculus component of periodontal disease index was scored utilizing the criteria of ramfjord (12), and gingival index (13) were recorded on ramfjord teeth to assess the oral health status, and gingival health using a mouth mirror and a probe. assessment of halitosis by a halimeter according to the manufacturer's instructions. evaluation of the interventions it began two weeks after implementation of ohe program to assess pli, gi, and halitosis scores again and continue after that two weeks interval for seven times. interventional part of the study the trial involved two groups; both of them received the ohe program. the teachers and the mothers were given a single educational input to conduct ohe and explain the purpose of the study to the adolescents. the selected teachers and mothers were trained for oral hygiene education program by organizing one-hour session for three days, then made a calibration for them. training was in the value of teeth and general health, diet, nutrition, oral anatomy and tooth development, causes and prevention of dental caries and periodontal disease, oral malodour, and emergency oral care at school (14). the educational material provided to adolescent included posters, videotapes, macromodels, puppet theatre, coloring drawings in order to increase motivation and participation of adolescents. the videotapes contain a demonstration on the proper technique of flossing were shown by using the laptop. in demonstration of oral hygiene procedures macromodels (dentures, brush and floss) were used. puppet theatre in the school plays an important role in transforming the educational material of dry matter to easy and more acceptable to learners (15). statistical analysis data were entered onto microsoft excel and statistically analyzed using spss version 20 software. according to the central limit theorem, in large samples (˃30or40), the sampling distribution tends to be normal, regardless of the shape of the data (16). the collected data were grouped and illustrated in tables, and the following statistical tests were carried out. levene's test procedure was used to find the homogeneity among the data. post hoc tests were used with a significant f-test and additional exploration of the differences among means is needed to provide specific information on which means and scheffe’s test were used in case of equal variances were assumed p-values less than 0.05 were considered as statistically significant and p-values more than 0.05 were regarded as not significant, while pvalues less than 0.01 were considered as a highly significant. results the sample the total sample consisted of 80 adolescents aged 12 years, 41 were males (51.25%) and 39 were females (48.75%) divided into two groups, (table 1). table 1: distribution of the sample according to teacher-led and mother-led groups j bagh college dentistry vol. 30(4), december 2018 the impact of 45 a= group supervised by the teacher, b= group supervised by the mother before giving the ohe program: dental plaque, gingival health condition and halitosis assessment table 2 revealed the mean value and the standard deviation of the plaque index, gingival index and halitosis scores for the sample among the groups at baseline examination. according to levene's test, statistically no significant differences were noticed between the groups for each variable (p>0.05). for calculus index, the study indicated no presence of calculus. scheffe repeated measure test between groups, according to mean differences showed that there were no significant differences p>0.05, (table 3). table 2: the mean values of the variables of the sample among the groups at baseline examination degree of freedom (df) =1, a= group supervised by the teacher, b= group supervised by the mother table 3: comparison by scheffe test between the groups according to variables at baseline examination sig. mean difference variables 0.974 -0.375 pli 0.659 -1.375 gi 0.686 -0.200 halitosis scores mean difference = mean of group a mean of group b after giving the ohe program dental plaque figure 1 shows the means of plaque, gingival, and halitosis scores of the sample at different examinations before and after implementation of the ohe program. at baseline examination, the group a has 2.16±0.37, 1.67±0.53, 2.57±0.67 for pli, gi, and halitosis scores respectively and the group b has 2.20±0.39, 1.81±0.50, 2.77±0.90 for pli, gi, and halitosis scores respectively. at the seventh examination after 14weeks from starting giving the ohe program, group a has 1.87±0.40, 1.39±0.42, 1.82±0.54 for pli, gi, and halitosis scores respectively, it had been found that there groups no. of males no.% no. of females no.% total no. no.% a 20 25 20 25 40 50 b 21 26.25 19 23.75 40 50 total 41 51.25 39 48.75 80 100 levene's test b a groups p-value f ±sd mean ±sd mean variables 496.0 0.155 90.0 00.0 00 0.00 020..4 pli 000.0 0.081 00.2 5.02.. 0.20 20..40 gi 024.0 3.767 90.0 0020.0 0.67 2.5750 halitosis scores j bagh college dentistry vol. 30(4), december 2018 the impact of 45 were reduction in pli, gi ,and halitosis scores while, there were increasing in the pli, gi, and halitosis scores for the b group as 2.05±0.45, 1.70±0.49, 2.52±0.75 for pli, gi, and halitosis scores respectively. levene's test of plaque index shows that there were no significant differences between baseline and seventh examinations for all the scores except for pli in the seventh examination. figure 1: the mean values of the variables of the sample among the study groups scheffe test for compound comparison showed that there were statistically high significant differences in gi, and halitosis scores between the baseline and the seventh examination but there is no significant differences in pli, (table 4). table 4: multiple comparisons by scheffe test sig. mean difference examination variable 0.974 -0.375 first pli 0.329 -0.175 seventh 0.659 -1.375 first gi 0.016** -0.312 seventh 0.686 -0.200 first halitosis score 0.000** -0.700 seventh ** highly significant p≤0.01, mean differences = mean of group a mean of group b scheffe test was done to find the differences in favor of any of the groups. the mean value for group a is the lower one for all variables, (table 5). therefore, it could be argued that group a is more effective in the full improvement than group b. j bagh college dentistry vol. 30(4), december 2018 the impact of 45 table 5: comparison of the means of groups according to scheffe test at seventh examination variables groups no. 1 2 pli a 40 1.87 b 40 2.05 gi a 40 1.39 b 40 1.70 halitosis scores a 40 1.82 b 40 2.52 a= group supervised by the teacher, b= group supervised by the mother, no.= number, 1= the lower mean value, 2= the higher mean value discussion in this study, the selection of the age group 12 could be related to that this age group was the pubertal so that the several hormonal changes could occur (17). several epidemiological studies revealed that the periodontal disease is widespread in children and may vary from community to another (18). other study has been reached different results (19). the effect of the program has been evaluated clinically as changes by means of indices, in oral hygiene effectiveness, gingival health, and halitosis assessment leading to evaluate the ohe program. in the present study, although the two groups were balanced in terms of oral hygiene at baseline examination, they reflect poor oral health because the children do not have any interest or knowledge about cleaning their teeth. it is important to say that this study found that the calculus was absent in these two group. this result does agree with other studies (20, 21), and disagree with an iraqi study (22). several previous studies found that dental knowledge effected on the oral hygiene (20, 21), and other study found that the dental knowledge and behaviour does not affected the oral hygiene (23). it can be concluded that good oral hygiene habits tend to decrease the prevalence of halitosis in accordance with an iraqi study (24). generally, the adolescents neglected their teeth as showed by others (25, 26). however, no statistically significant difference was found between all groups at baseline examination. the group supervised by teacher has the lower means of pli, gi, and halitosis scores reflecting the increase in group's leader awareness and participation. the teacher-led group was due to the dynamic interaction between the teacher and specific students group. the teachers knew about the poor dental conditions in children and wanted to become involved in ohe. this study is agree with other study (27) which suggested that the teachers had positive attitudes toward enlightening the parents about the importance of oral hygiene and teaching the children about preventive dentistry, while that they were less motivated about being involved in dental health school programs. at the level of influence of the teachers on the adolescents, the current study goes with other investigators (28, 29) who specified that the majority of teachers demonstrated positive oral health attitude in the regard of their own involvement in the school-based dental health education because teachers believe that dental hygiene education is crucial for students' wellbeing as mentioned by other researcher (4). while this study is incompatible with other researcher (30) who conducted that primary school teachers have a poor attitude to oral health issues. the results indicate that the effect of ohe program were effective in improving the students' knowledge and practices toward oral health. the present results represent the important role of parents in improving and supporting the oral health status and behaviour of their offspring. as a result mothers should be empowered in their parenting and have more effective communication with their sons as mentioned by other study (31). the parents have got an important role in improving and maintaining the oral health status and behaviour of the children. this finding goes in line with other studies (10, 32-34) because the support by family is crucial in the development of children's habits in relation to health. childrenparents cooperation was considered an important component of the present oral hygien education program. the mothers were invited to schools in order to encourage them for high responsibility with regard to their child's teeth as stated by 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health behaviour on oral health status of their school children: an exploratory study employing a causal modelling technique. international journal of paediatric dentistry. 2002;12(2):101-8. 39. aleksejūnienė j, brukienė v. parenting style, locus of control, and oral hygiene in adolescents. medicina (kaunas). 2012;48(2):102-8. المستخلص ومع ذلك، صحة الفم هي جزء ال يتجزأ من الصحة العامة، واثارها وبشكل كبير على . المراهقة هي واحدة من المراحل األكثر ديناميكية في التنمية البشرية :الخلفية وكان الهدف من هذه الدراسة لتقييم نتائج صحة الفم واألسنان على المراهقين من . برنامج التثقيف الصحي الفوي هو قضية مهمة يجب أن تعطى لهم. نوعية الحياة .قبل المعلمين واالمهات اسبوعا قد قيمت فعالية برنامج التثقيف الصحي 41استغرقت الدراسة التي. )ديالى( تمت الدراسة بطريقة عشوائية في مدارس في مدينة بعقوبة :المواد والطرق من المدارس المختارة . من كال الجنسين( عاما 41)مراهق يتمتع بصحة جيدة في الفئة العمرية 08لـ الفموي على صحة الفم و صحة اللثة والرائحة الكريهة بواسطة صحتهم تم تقييم .األمهاتالمجموعة االخرى تلقت البرنامج من المعلمين ، وتلقت برنامج التثقيف الصحي الفموي تحت إشراف كانت هناك مجموعة ،التهاب وميةم مؤشرات اللويحة الجرثباستخدا قد قيمتالكريهة الفم رائحةاللثة و ان صحة الفم و صحة. وقد تم تنظيم ورشة عمل تدريبية لمدة ثالثة ايام .االستبيان . التوالي اللثة ورائحة الفم الكريهة على ين المجموعة الث من ببينت النتائج ان هناك انخفاض كبير في مؤشرات اللويحة الجرثومية،التهاب اللثة ورائحة الفم الكريهة وكانت ادنى المؤشرات الث :النتائج .((p<0.01 المجموعة التي تقودها األم وكانت ذات داللة إحصائية عالية مقارنة معالمعلم التي يقودها م وصحة األم في تحسين وضع صحة الفمن المجموعة التي تقودها ان برنامج التثقيف الصحي الفموي أكثر فاعلية في المجموعة التي يقودها المعلم :االستنتاجات .اللثة والرائحة الكريهة للمراهقين 24. hiba f.doc j bagh college dentistry vol. 25(1), march 2013 shear bond strength orthodontics, pedodontics and preventive dentistry146 shear bond strength of different lingual buttons bonded to wet and dry enamel surfaces with resin modified glass ionomer cement (in vitro comparative study) hiba m. alkhateeb, b.d.s. (1) eman i. al-sheakli, b.d.s., m.sc. (2) abstract background: this study was aimed to investigate the effect of three lingual button (nickel free / rectangular base, nickel free / round base and composite) and bonding environment, wet and dry enamel surface, on: the shear bond strength (sbs) of light and self-cured resin modified glass ionomer cements, and the debonding failure sites. materials and method: one hundred twenty no-carious, free of cracks maxillary first premolar teeth were selected. three types of orthodontic lingual buttons were used in this study: nickel free / rectangular base, nickel free / round base and composite buttons. the teeth were divided into two groups of sixty teeth each. one group was used for testing the chemically cured gc fuji ortho resin modified glass ionomer (rmgic), while the other was used for testing the light cured gc fuji ortho lc rmgic. each was further subdivided into two subgroup; thirty teeth were bonded to wet enamel surface while the other was bonded after drying the enamel surface. then each ten teeth from each subgroup were bonded with only one type of buttons. the sample was tested for bond strength using the universal testing machine and the adhesive remnant index (ari) was inspected under the stereomicroscope. results:the highest (sbs) values were obtained in the nickel free / round base button with both types of rmgic in wet and dry environment as revealed by anova test. while t-test revealed that both systems of rmgic yield relatively lower values of (sbs). conclusions:the gc fuji ortho rmgics resist shear force in dry better that in wet environment.nickel free / round base buttons give the greatest shear bond strength among the three types of button.the composite buttons give greater bond strength in dry than in wet environment with both gc fuji ortho and gc fuji ortho lc rmgics. key words: shear bond strength, lingual buttons, rmgic. (j bagh coll dentistry 2013; 25(1):146-152). introduction since bonding procedures have been improved, direct bonding of molar tubes and lingual buttons is frequently practiced in current orthodontics, the bond strength of orthodontic brackets has been widely tested; however, there are no sufficient studies investigating the bond strength of different lingual buttons types and which one is clinically more preferable than the other (1). although in vitro lingual bond strengths are comparable with labial bond strengths (2), the bond strength of lingual buttons on lingual surface might be relevant because the oral condition is different in this area, due to the higher risk of contamination with saliva (1). resin modified glass ionomer cements were introduced that combine the properties of composites and glass ionomersand overcomethe glass ionomer disadvantage of relatively low shear bond strength(3). although traditional bond materials must be applied in completely dry and isolated fields to produce clinically acceptable bond strengths (4). some manufacturers have started to introduce hydrophilic substances into their compositions. these substances allow for greater shear bond strength on wet surfaces (5). (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad. these hydrophilic bond systems have been considered as an important development in orthodontic practice because many routine clinical procedures are not carried out under ideal conditions (6). since there is no previous iraqi study measuring the shear bond strength at the lingual surface, this study was carried out to investigate the shear bond strength of three lingual button types (nickel free / rectangular base, nickel free / round base and composite) bonded to wet and dry enamel surface with chemical cured and light cured rmgic, and to measure their ari. materials and methods the sample three hundred eighty seven extracted human maxillary first premolar teeth were collected, which have been extracted from patients seeking orthodontic treatment; the collected teeth were stored in normal saline (sodium chloride solution 0.9%) containing crystals of camphor phenol (thymol) to prevent dehydration and bacterial growth in closed container at room temperature until preparation and testing(7). after examining the teeth with 10x magnifying lens (8) one hundred twenty teeth were selected, they were having grossly intact lingual enamel surface with no surface cracks, free of caries (9)and not subjected to any pretreatment chemical agents, such as hydrogen peroxide or formalin. three j bagh college dentistry vol. 25(1), march 2013 shear bond strength orthodontics, pedodontics and preventive dentistry147 types of lingual buttons were used in this study: nickel free / rectangular base buttons, nickel free / round base buttons and composite (orthoflex®) buttons. the base surface area of the buttons were 9.6224mm², 9.625 mm² and 5.8425 mm² respectively, as provided by the company (ortho technology company, usa). method the selected one hundred and twenty teeth were divided into two equal groups (1 and 2), containing sixty teeth each according to the type of orthodontic adhesivegroup 1 was bonded with chemical cure rmgic (gc fuji ortho, gc corporation/japan), while group 2 was bonded with light cured rmgic (gc fuji ortho lc, gc corporation/japan). group 1: the light cured samples were subdivided into two subgroup according to the condition of enamel surface (wet or dry) containing thirty teeth each: subgroup a was bonded to wet enamel surface subgroup b was bonded after drying the enamel surface group 2: the chemically cured samples were subdivided into two subgroup according to the condition of enamel surface (wet or dry) containing thirty teeth each: subgroup c was bonded to wet enamel surface subgroup d was bonded after drying the enamel surface then within each subgroup (a, b, c, and d): 1st ten teeth were bonded with nickel-free rectangular base buttons, 2nd ten teeth were bonded with nickel-free round base buttons, 3rd ten teeth were bonded with composite buttons. retentive grooves were made on the roots of the teeth to increase the retention of the teeth inside the acrylic blocks(10). each tooth was fitted on the glass slide using a sticky wax and was positioned so that the middle third of the lingual surface is oriented to be parallel with the analyzing rod of dental surveyor(11, 12)(fig. 1). another three teeth was placed in the same manner with a distance of 1 cm between each other. then two l-shaped metal plates, were painted with a thin layer of separating medium (vaseline) (11) which then were placed around the teeth (figure 1). then the powder and liquid of the self-cured acrylic were mixed and poured around the teeth to the level of the cementoenamel junction(13). after setting of the self-cured acrylic resin, the two l-shaped metal plates were removed and the specimens were coded and stored in normal saline solution containing crystals of thymol until bonding(14). the lingual surface of each tooth of the twelve subgroups was polished using nonfluoridated pumice/water mixture with a rubber cup attached to a low speed handpiece for 10 seconds (15).then each tooth was washed with water spray for 10 seconds (13, 16) then dried by oil-free air for 20 seconds. subgroup a: the bonding was done according to manufacturer instruction. after polishing, the enamel surface of each tooth in this subgroup was prepared wet using a cotton roll soaked in distilled water before the button was bonded (17). the standard powder to liquid ratio was 3.0g/1.0g was mixed. immediately after applying the adhesive to the button base, the button was placed gently onto the middle third of the lingual surface using a clamping tweezers.a constant load was placed on the button for 10 seconds (18)to ensure seating under an equal force and to ensure a uniform thickness ofthe adhesive and prevent air entrapment which may affect bond strength (19) (fig. 1). each button was then light cured for 40 seconds (10 seconds on each mesial, distal, occlusal and gingival side) (according to manufacture instruction) at a distance of 1 mm from the button (18)using the “led” light cure unit (woodpecher co., china). the adjacent teeth were covered with polishing rings before curing (to protect them from the effect of light cure unit) (20). after the completion of the bonding procedure, the teeth were immersed in normal saline (13) and stored in the incubator at 37˚c for 24 hours after which they were shear tested to debond(10, 17, 18). subgroup b: bonding procedure was done in the same stepsof the subgroup a except that after polishing, the enamel surface was dried before bonding with oil-free air for 20 seconds (21). subgroup c: bonding procedure was done in the same steps of the subgroup a except that the bonded buttons were left on bench to allow the adhesive to self-cure approximately 7 minute from the start of mixing time without exposure to light. subgroup d: bonding procedure was done in the same steps of the subgroup b except that the bonded buttons were left on bench to allow the adhesive to self-cure approximately 7 minutes without exposure to light. the shear test was carried out using a tiniusolsen universal testing machine with a crosshead speed of 0.5 mm/minute (1, 22, 23)(fig. 2), the reading were recorded in newtons. the force was divided by the surface area of the button base to obtain the stress value in mega pascal units. after debonding, the enamel surface of each tooth was examined under x10 magnification with the stereomicroscope to determine the j bagh college dentistry vol. 25(1), march 2013 shear bond strength orthodontics, pedodontics and preventive dentistry148 amount of residual adhesive remaining on each tooth (1, 24). the adhesive remnant index (ari) scores were recorded as described by wang et al. (25)as follows: score i: between the bracket base and the adhesive. score ii: cohesive failure within the adhesive itself, with some of the adhesive remained on the tooth surface and some remained on the bracket base. score iii: adhesive failurebetween the adhesive and the enamel. score iv: enamel detachment. statistical analysis data were collected and analyzed using spss (statistical package of social science) software version 17 for windows xp. in this study the following statistics were used: a. descriptive statistics: including mean, standard deviation, minimum, maximum, and percentage. b. inferential statistics:including: 1. one way analysis of variance (anova): to test any statistically significant difference among the shear bond strength of different bonding agents and the difference among different button material through using f (fissure exact) test. 2. least significant difference (lsd): when anova showed a statisticalsignificant difference. the lsd will be used to test any statistically significant differences between each two subgroups within the same group. 3. t-test:to test any significant differences between mean shear bond strength of each two subgroups at different enamel surface condition (wet and dry enamel surface). 4. chi-square: to test any statistically significant differences between the groups for the failure site examination results. p (probability value) level of more than 0.05 was regarded as statistically non-significant. while a p-level of 0.05 or less was accepted as significant as follows: 0.05≥ p > 0.01 * significant. 0.01≥ p > 0.001**highly significant. p ≤ 0.001*** very highly significant. results generally, sbs values were compared between the three lingual buttons types in wet and dry environment by using the light and selfcured rmgic adhesive systems. effect of different button types the highest sbs values were found in nickel free / round base buttons in both environments with non-significant difference between wet and dry enamel surface, while the nickel free / rectangular base yielded lower values of sbs than the previous type inboth environments with also, a non-significant difference between wet and dry enamel surface. the composite buttons showed a highly significant difference between the two environments with higher values in dry environment (table 1). effect of different environments the light cured (gc fuji ortho lc) rmgic adhesive showed non-significant difference between wet and dry environments, while the self-cured (gc fuji ortho) rmgicadhesive yields higher values of sbs in dry environment with a significant difference between the two environments (table 2). effect of different adhesive systems there was non-significant difference between the sbs values of the light cured (gc fuji ortho lc) and the self-cured (gc fuji ortho) rmgic adhesives with relatively lower values of sbs obtained from both adhesives (table 3). adhesive remnant index “ari” the attachment base-adhesive failure (score i) was most predominant (50 %) in wet environment in the samples bonded with lightcured rmgic using nickel free / rectangular base buttons.while the cohesive failure (score ii) was most predominant (60 %) in dry environment in the sample bonded with selfcured rmgic using nickel free buttons, andin wet environment in the samples bonded with self-cured rmgic using composite buttons. while the adhesive-enamel interface failure (score iii) was most predominant (80 %) in wet environment in the samples bonded with lightcured rmgic using composite buttons. however, the scores never reached (score iv) in any specimen (table 4). discussion nickel-free / round base metal buttons (fig. 3) showed the highest value of sbs than the two other types of button. this result could be due to the surface area of the button base (9.625 mm2) which is closed to the adequate surface area for retention 6.8 mm2 as proposed by mac coll et al. (26) and this in agreement with wang et al. (27), while disagree with sőderholm et al. (28)who reported that the enlarging the surface area will increase the load carrying capacity and there is an inverse relationship between bond strength and bonded surface area. nickel free/rectangular base metal button showed lower mean values of sbs. this result could be due to the poor adaptation between the button base and the tooth surface, the wider area j bagh college dentistry vol. 25(1), march 2013 shear bond strength orthodontics, pedodontics and preventive dentistry149 of the rectangular base mesiodistally sometimes may not fit or resemble the curvature of the lingual surface of the tooth, resulting in thick adhesive layer that could result in weak bond strength, and this comes in accordance with ariciet al.(29) who concluded that too much increase in the rmgic thickness will result in lower values of bond strength that encountered to the polymerization reactions. the composite buttons showed lowest mean values of sbs in wet environment, this result could be attributed to the button base design which only provided with three relatively large dove tail grooves (fig. 3), this is in agreement with garma et al. (10) and disagreement with soderquist et al. (30) who reported that bond strength of attachmentswith integral bases were shown to be improved whenresin cement was used. in addition, the result could be due to the smaller surface area of the button base as compared to those of nickel free / metal type, and this agrees with wang et al. (27), and disagree with kwong et al. (31) who shown an inverse relationship between bond strength and bonded surface area. the self-cured adhesive yielded a higher value of sbs in dry environment, this might be explained that in the self-cured system with the absence of wet enamel surface, the initiation of water-soluble hema monomer will take place upon mixing by the chemically activated freeradical polymerization approach and the final hardening and strengthen of the adhesive is enhanced by the formation of polycarboxylate salt matrix (32). while the light-cured adhesive showed no significant difference between wet and dry environment, this could be due to the addition of hydrophilic hema monomer (32, 33), which enables the adhesive to pass beyond resin coating formed by moisture on enamel surface (5). this results is in disagree with coups-smith et al. (17) and al-shamsi et al. (34) who demonstrated that fuji ortho lc performs significantly better shear bond strength on wet enamel. at both environment / attachment combinations there was no significant difference between the self-cured and light-cured rmgic adhesives, this might be due to same compositions of both system (32). this result in disagree with coups-smith et al. (17) who stated that the self-cured cement provided significantly higher bond strength than the light-cured system. these results were lower than the accepted clinical minimal value of shear bond strength (5.9 mpa) as proposed by renyolds and von fraunhofer(35), which might be accounted to that enamel surface of all teeth was not conditioned which might lead to weak mechanical retention. this result is in accordance with (godoy-bezerra et al. (36) while disagree with ewoldsen(37)who found no significant differences between none conditioned and conditioned enamel.also, the results could be explained by that the enamel surface was not etched. the bond strength of rmgics has been shown to be reduced by onethird to one-half without acid etching because 37% phosphoric acid produces a qualitatively rougher enamel surface, thus facilitating the penetration of the adhesive resin(38). score i was most predominant (50%) in wet environment in the samples bonded with lightcured rmgic using nickel free / rectangular base buttons. this is, probably, because of the air entrapment behind the base of the button which significantly affects polymerization and may produce lower bond strength between the button and the adhesive material (39), this is in agree with toledano et al. (40). score ii was most predominant (60 %) in dry environment in the samples bonded with selfcured rmgic using nickel free buttons, also it was predominant in wet environment in the samples bonded with self-cured rmgic using composite buttons,it could be due to the small projections of metal buttons which acted as a stress concentration areas from which the adhesive failure may begin and propagate through the remaining part of the adhesive, this is in agree with the finding of maijer and smith (39). in orthodontic bond strength testing, cohesive fractures reflect the internal strength of the adhesive rather than the actual adhesion to the surface under study (41). score iii was most predominant (80 %) in the sample bonded with light-cured rmgic using composite buttons in wet environment.when using rmgics, and especially when acid etching is not used, almost all the failure sites were at the cement-enamel interface (40). this finding could be due to the reduced depth of demineralization. score iv was absent, which means that even the highest bond strength values were not sufficient to damage the enamel surface. this result comes in accordance with santos et al.(5). references 1.scougall-vilchis rj, saku s, kotake h, yamamoto k. influence of different self-etching primers on the bond strength of orthodontic lingual buttons. eur j orthod 2010; 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29: 621-4. 38. bishara s e, olsen m e, damon p, jakobsen j r. evaluation of a new light-cured orthodontic bonding adhesive. am j orthod dentofac orthop 1998; 114: 80–7. 39. maijer r, smith dc. variables influencing the bond strength of metal orthodontic bracket bases. am j orthod 1981; 79(1): 20-34. 40. toledano m, osorio r, osorio e, romeo a, higuera b, garcı´a-godoy f. bond strength of orthodontic brackets using different light and self-curing cements. angle orthod 2003; 73: 56–63. 41. zachrisson bu, buyukyilmaz t. surface preparation for orthodontic bonding to porcelain. am j orthod dentofac orthop 1996; 109:420–30. table 1: descriptive statistic of sbs in different environments using three types of buttons. buttons environment descriptive statistics differences in environment mean (mpa) s.d. t-test p-value nickel-free / rectangular base (i) wet 3.73 1.02 -0.35 0.73 (ns) dry 3.91 1.07 nickel-free / round base (ii) wet 6.21 1.28 0.64 0.52 (ns) dry 5.82 1.51 composite (iii) wet 3.04 0.37 -2.97 0.005 ** dry 4.75 1.18 table 2: descriptive statistics of sbs of rmgic adhesives in different environments. adhesive environments descriptive statistics differences in environments mean (mpa) s.d. t-test p-value self-cured wet 3.89 1.02 -2.5 0.015 * dry 5.25 1.16 light-cured wet 4.76 1.2 0.71 0.48 (ns) dry 4.39 1.06 table 3: descriptive statistics of sbs of rmgic adhesive systems. adhesive descriptive statistics differences in adhesive mean (mpa) s.d. t-test p-value self-cured 4.575 1.12 -0.013 0.99 (ns) light-cured 4.580 1.09 table 4: distribution and percentage of adhesive remnant index. adhesive ari wet dry nickel free/ rectangular base button nickel free/ round base button composite button nickel free/ rectangular base button nickel free/ round base button composite button no % no % no % no % no % no % self-cured i 1 10 1 10 1 10 0 0 1 10 1 10 ii 3 30 2 20 6 60 6 60 6 60 2 20 iii 6 60 7 70 3 30 4 40 3 30 7 70 iv 0 0 0 0 0 0 0 0 0 0 0 0 light-cured i 5 50 4 40 2 20 4 40 4 40 1 10 ii 2 20 3 30 0 0 2 20 3 30 2 20 iii 3 30 3 30 8 80 4 40 3 30 7 70 iv 0 0 0 0 0 0 0 0 0 0 0 0 j bagh college dentistry vol. 25(1), march 2013 shear bond strength orthodontics, pedodontics and preventive dentistry152 figure 1: a, fitting the tooth with a sticky wax and oriented so that the middle third of lingual surface is made parallel to the analyzing rod of surveyor. b, two l-shaped metal plates placed around the teeth. c, load placement over each button. figure 2: shear bond strength test figure 3: composite button (a), nickel free/round base button (b) used in this study. a b a c b maha final.doc j bagh college dentistry vol. 26(3), september 2014 analysis of antimicrobial restorative dentistry 27 analysis of antimicrobial activity of root canal sealers against endodontic pathogens using agar diffusion test (in vitro study) maha a. habeeb, b.d.s., m.sc. (1) abstract background: antibacterial action of root canal filling is an important factor for successful root canal treatment, so the aim of the study was to identify and to compare the antimicrobial effect of new sealer (guttaflow) to commonly used endodontic sealers (ah plus, apexit and endofill) against four endodontic microbes. materials and methods: twenty patients aged (30-40) years with infected root canals were selected. four types of microorganisms were isolated from root canals (e faecalis, staphylococcus aureus, e coli and candida albicans) and cultured on mueller hinton agar petri-dishes. after identification and isolation of bacterial species, agar diffusion method was used to assess the antibacterial action of four contemporary endodontic sealers used in root canal obturation (ah plus, apexit, endofill and guttafflow). four wells measuring (5mm depth and 4mm diameter) were created in each petri dish and sealer was applied into them incubated overnight at 37 c° for bacterial species and 48 hr. at 37 c° for candida albicans prior to determination of results. zones of inhibition (no growth of bacteria) were examined around the wells containing sealer & diameters of the zones were measured in mm. the mean of inhibition zones for each group was measured and statistically analyzed among groups using anova and between groups using lsd tests. results: there was a highly significant difference (p<0.001) among all the tested groups. endofill showed the maximum antibacterial action against tested microorganisms. guttaflow showed moderate to weak antimicrobial effect, apexit had weak effect, while ah plus had no antibacterial action. conclusion: all the tested materials except ah plus had antibacterial efficacy against e faecalis, staphylococcus aureus, e coli and candida albicans. endofill had favorable results among tested sealers and e faecalis was the most resistant bacteria, but none of the materials totally inhibited microbial growth. thus, endodontic treatment must be performed under aseptic conditions. keywords: endodontic sealers, anaerobic bacteria, candida albicans, mueller hinton agar and agar diffusion test. (j bagh coll dentistry 2014; 26(3):27-34). introduction comprehensive and successful obturation of root canals is directly related to adequate removal of microorganisms and their by-products which can be done by mechanical root canal instrumentation, antibacterial irrigation and adequate filling of the root canal space (1). however, these procedures do not completely sterilize the root canal system due to the anatomical complexities of many root canals, such as dentinal tubules, ramifications, deltas, and fins which cannot be sufficiently cleaned, even after meticulous mechanical procedures. thus bacteria may penetrate into an obturated root canal within few days; persisting or re-infecting bacteria may induce or sustain apical periodontitis (2). facultative and strict anaerobic bacteria are the most common microorganisms of the endodontic microbiota and cause infections that stimulate periapical bone resorption and refractory to endodontic treatment. the most resistant species in the oral cavity are facultative microorganisms such as enterococcus faecalis, staphylococcus aureus and even candida albicans which could cause failure of root canal treatment. therefore, endodontic fill (1)lecturer. department of conservative dentisrty. college of dentistry, university of baghdad ing materials should be antibacterial/antimicrobial and this can be done by adding anti-microbial agents to root canal sealers (3). today, numerous sealers are available based on various formulas, such as epoxy resin sealers, calcium-hydroxidebased materials, gutta purcha based sealer and zinc oxide eugenol (zoe) cements with and without paraformaldehyde additions (4). zoe based sealers have some antimicrobial activity because of the diffusion property of zinc oxide and eugenol into the agar media (5). calcium hydroxide compounds are widely used because of their alkalinity that provides excellent bactericidal effect. resin-based root canal filling materials have steadily gained popularity and are now accepted and used for anterior and posterior teeth. the bonding systems have improved sealing ability, which explains the resistance of some materials to bacterial penetration (6). guttaflow is a contemporary endodontic material based on polyvinylsiloxane (polydimethyl siloxane) that consists of guttapercha and injectable system (7). the agar diffusion method has been widely used to test the antimicrobial activity of dental materials and medications; the advantage of this method is that it allows direct comparisons of root canal sealers against the test microorganisms, j bagh college dentistry vol. 26(3), september 2014 analysis of antimicrobial restorative dentistry 28 indicating which sealer has the potential to eliminate bacteria in the local microenvironment of the root canal system (8). the objective of this study was to analyze in vitro the antimicrobial properties of new sealer which is (guttaflow) and compare it with three contemporary endodontic materials used as sealers in root canal obturation (ah plus, apexit and endofill) against different microorganisms. materials and methods in this study, four contemporary endodontic materials were used as sealers in root canal obturation which are gutta purcha containing sealer (roeko guttaflow® 2 fast.coltene/ germany), resin based sealer (ah plus. dentsply/ germany), calcium hydroxide sealer (apexit. voco / germany ) and zoe based sealer (endofill. pd / switzerland), table (1) and fig. (1). table 1: types of sealers used and their ingredients sealer ingredient ah plus paste a epoxy resin calcium tungstate zirconium oxide aerosol iron oxide silica iron oxide pigments paste b adamantane amine n. ndibenzoyl 5-oxanonane tcd-diamine calcium tungstate zirconium oxide aerosil silicone oil silica apexit paste a calcium hydroxide / calcium oxide hydrated collophonium fillers and other auxiliary materials (highly dispersed silicon dioxide, phosphoric acid alkyl ester) paste b disalicylate bismuth hydroxide / bismuth carbonate fillers and other auxiliary materials (highly dispersed silicon dioxide, phosphoric acid alkyl ester) guttaflow paste a polydimethylsiloxane, silicone oil, zirconium oxide, paste b gutta-percha endofill powder: zinc oxide hydrogenated resin bismuth subcarbonate barium sulfate sodium borate liquid: eugenol sweet almond oil bacterial strains three standard bacterial strains were used in the study which were, g+ve staphylococcus aureus and enterococcus faecalis, which were isolated and cultured on blood agar media, g-ve e.coli which was isolated and cultured on macconkey agar media (sisco research inc. india), also one fungal strain candida albicans which was isolated and cultured on a sabouraud agar media (thermomfisher scince inc. uk). the antibacterial effect of the tested materials was assessed using agar diffusion method. sterilization method sterilization of mouth mirror, kidney dishes and all clean glasses were conducted by dry air oven at 180 cº for 1 hour. benches and floor of figure 1: sealers used in the study j bagh college dentistry vol. 26(3), september 2014 analysis of antimicrobial restorative dentistry 29 the laboratory were disinfected by detol antiseptic solution (9). patient selection and isolation of bacteria twenty patients aged (30-40) years with infected root canals which were diagnosed clinically and radiographically and none of them had received any antibiotic treatment for three months. rubber dam was used for isolation of teeth before microbiological sampling and the teeth were disinfected with 10% povidone iodine solution to avoid contamination of working field. access opening was prepared after all caries were removed and coronal restorations using new fissure bur for each tooth. after confirmation of working length radiographically, each root was instrumented using new sterile barbed broaches and files, and then a sterile paper point was introduced inside canals and left for 1 min. and then removed and placed immediately into a transporting media to preserve bacteria from damage or death and microorganisms were isolated within 4 hrs (10). identification of bacterial species microorganisms were identified at microbiology department (al-nahrin medical college). based on colony morphology (size, shape, and color), selected colony for each bacteria was subcultured aerobically and anaerobically and those bacteria which failed to grow aerobically were identified to be anaerobes. biochemical tests were used to distinguish between g+ve and g-ve bacteria; api 20e test (biofire diagnostics, inc. usa) was used to identify g+ve bacteria while api strep (biomérieux, france) test was used to identify gve bacteria. api candida (biomérieux, france) was used to recognize fungal species (candida albicans) (11). reactivation and subculturing of microorganisms brain heart infusion (bhi) broth (biomark company / india) was used for the reactivation of the bacterial species (entrococc fecalis, staphylococcus aureus and e.coli after isolation of each microorganism. in order to standardize the final turbidity to the 0.5 standard of the mcfarland scale, microorganisms were seeded in 20 × 10 mm sterile petri dishes containing agar media supplemented with 5% blood using swabs saturated in the bacterial suspension and incubated at 37 cº for 24hr. candida albicans was reactivated in sabouraud agar broth and seeded in petri dishes containing sabouraud agar medium in the same way as described for the bacterial species and incubated at 37 cº for 48hr (12). sample grouping a total of 50 plates containing agar media were divided into four test groups and one control group (10 plates for each group). each type of microorganism was tested ten times: group i: 10 plates were inoculated with staphylococcus aureus containing 4 types of sealers. group ii: 10 plates were inoculated with e. coli containing 4 types of sealers. group iii: 10 plates were inoculated with enterococcus faecalis containing 4 types of sealers. group iv: 10 plates were inoculated with candida albicans containing 4 types of sealers. group v: 10 plates with inoculums, without any sealer as a positive control group. plate’s preparation petri dishes (20×10 mm) containing agar media were inoculated with bacterial suspension by using cotton tipped applicator using sterile swabs and 100 aliquots of each microbial suspension were spread on the petri dishes. after dividing the petri dish into four equal sections, a copper coil was used to create four wells (5mm in depth, 4mm diameter) on the petri dishes and these wells were made at equal distance from each other. sealers were mixed on sterile glass plates using sterile stainless steel spatula according to manufacturer instructions and placed immediately in the wells in concentration of 0.2 ml to have equal amount of sealer in each well. the positive control groups were streaked with bacteria but no root canal sealer was used, then plates were left for 2hr. at room temperature for diffusion of sealer and to ensure direct contact between sealer and microorganism. the plates were incubated aerobically at 37cº for 24hr considering bacterial species and 48hr for fungal species (2, 13,14). sealer susceptibility test these tests for the four types of microorganism (enterococcus faecalis, staphylococcus aureus, e. coli and candida albicans) were done with agar diffusion method. the inhibitory zones were considered to be the shortest diameter from the outer margin of the well to the initial point of the microbial growth using a digital caliber with a resolution of 0.01 mm under reflects light (15) and the measurements j bagh college dentistry vol. 26(3), september 2014 analysis of antimicrobial restorative dentistry 30 were recorded at 24 hours for each bacterial species and 28 hrs for candida albicans. experiments were repeated 10 times (n=10) and the mean of readings were recorded (16). results the mean, standard deviation, standard error, minimum reading and maximum calculations of the zones of inhibition of microbial growth in mm of each endodontic sealer have been summarized in table (2) and fig. (3). the inhibitory potential of each material was categorized as strong, moderate strong, moderate, weak, or non-inhibitory depending on the average size of the zones, table (3). all sealers showed zones of inhibition against microorganisms except for control and ah plus groups which showed no inhibitory effect on all tested microorganisms. endofill produced the largest inhibitory zone followed by guttaflow, on the other hand; apexit produced the smallest inhibitory zones against the tested microorganisms (by average values), fig.(4). in this study the results found that distilled water (control group) showed no inhibition of growth of tested microorganisms. furthermore it appears that e.faecalis was the most resistant organism to the effect of the sealers in this experiment. endofill had the largest inhibitory zone on s. aureus followed by e.coli then candida albicans and e.faecalis. table 2: mean values of antimicrobial activity of root canal sealers against microorganisms group subgroups mean (mm) zone categories sd ± se min. max. staphylococcus aureus ah plus 0 no 0 0 0 0 apexit 2.1 no 0.5 0.2 1.5 2.5 endofill 19.4 moderate strong 0.5 0.3 19 20 guttaflow 9.6 moderate 0.5 0.1 9 10 control 0 no 0 0 0 0 e.coli ah plus 0 no 0 0 0 0 apexit 2.4 weak 0.5 0.1 2 3 endofill 9.4 moderate 0.4 0.1 9 10 guttaflow 5.6 moderate 0.3 0.1 5 6 control 0 no 0 0 0 0 e.faecalis ah plus 0 no 0 0 0 0 apexit 0.6 no 0.4 0.1 0 1 endofill 4.4 weak 0.5 0.1 4 5 guttaflow 2.4 weak 0.3 0.1 2 3 control 0 no 0 0 0 0 candida albicans ah plus 0 no 0 0 0 0 apexit 1.6 no 0.5 0.2 1 2 endofill 6.6 moderate 0.4 0.2 5 7 guttaflow 3.4 weak 0.3 0.1 3 4 control 0 no 0 0 0 0 figure 2: types of agars used acandida albicans inoculated on sabouraud agar be coli inoculated on macconkey agar ce faecalis and staphylococcus aureus inoculated on blood agar j bagh college dentistry vol. 26(3), september 2014 analysis of antimicrobial restorative dentistry 31 m ea n figure 4: inhibition zones of the tested sealers statistical analysis of data by using analysis of variance (anova) was done which showed that there was a statistically high significance difference (p< 0.001) between the four endodontic sealers in their antibacterial action against all tested microorganisms, table (4). table 4: anova test to show the statistical difference of antimicrobial effect between endodontic sealers against microorganisms microorganism f p value sig. staphylococcus aureus 253 0.00 hs٭ e.coli 450 0.00 hs٭ e.faecalis 101 0.00 hs٭ candida albicans 214 0.00 hs٭ .highly significant at level p<0.001 ٭ when a significant difference was found, least significant difference (lsd) test was done to analyze the data to show the difference in susceptibility against microorganisms between different pairs of sealers, table (5, 6, 7 and 8). these investigations had shown that there was a highly significant difference among each pair of sealers against all tested microorganisms: 1. ah plus had a high significant difference p<0.001 compared to apexit, endofill, and guttaflow, except for e.faecalis group in which there was significant difference p<0.05 between ah plus and apexit. 2. apexit showed highly significant difference p<0.001 compared to endofill, guttaflow and control, except for e.faecalis and candida groups in which there was a significant difference p<0.05 between apexit and guttaflow. 3. endofill showed high significant difference p<0.0001 compared to guttaflow and control. 4. guttaflow showed highly significant difference p<0.001 compared to control. table 5: lsd test to compare the antibacterial action between each pair of endodontic sealers against staphylococcus aureus sealer p value sig. ah plus vs. apexit 0.00 hs٭ ah plus vs. endofill 0.00 hs٭ ah plus vs. guttaflow 0.00 hs٭ apexit vs. endofill 0.00 hs٭ apexit vs. guttaflow 0.00 hs٭ apexit vs. control 0.00 hs٭ endofill vs. guttaflow 0.00 hs٭ endofill vs. control 0.00 hs٭ guttaflow vs. control 0.00 hs٭ .highly significant at level p<0.001 ٭ rank range of zone diameter (mm) no 2 weak 2.4-6.2 moderate 6.3-10.3 moderate strong 10.4-26.8 strong >26.8 (s. aureus) (e.coli) (e. faecalis) (candida albicans) table 3: inhibition categories according to the proportional distribution of the data set figure 3: bar chart showing differences between the mean of inhibition zones of endodontic sealers produced against tested microorganisms j bagh college dentistry vol. 26(3), september 2014 analysis of antimicrobial restorative dentistry 32 table 6: lsd to compare the antibacterial action between each pair of endodontic sealers against e.coli sealer p value sig. ah plus vs. apexit 0.00 hs٭ ah plus vs. endofill 0.00 hs٭ ah plus vs. guttaflow 0.00 hs٭ apexit vs. endofill 0.00 hs٭ apexit vs. guttaflow 0.01 hs٭ apexit vs. control 0.00 hs٭ endofill vs. guttaflow 0.00 hs٭ endofill vs. control 0.00 hs٭ guttaflow vs. control 0.00 hs٭ .highly significant at level p<0.001 ٭ table 7: lsd to compare the antibacterial action between each pair of endodontic sealers against e. faecalis sealer p value sig. ah plus vs. apexit 0.04 s٭ ah plus vs. endofill 0.00 hs٭ ah plus vs. guttaflow 0.00 hs٭ apexit vs. endofill 0.00 hs٭ apexit vs. guttaflow 0.01 s٭ apexit vs. control 0.04 s٭ endofill vs. guttaflow 0.00 hs٭ endofill vs. control 0.00 hs٭ guttaflow vs. control 0.00 hs٭ .highly significant at level p<0.001 ٭ ٭ significant at level p<0.05. table 8: lsd to compare the antibacterial action between each pair of sealers against candida sealer p value sig. ah plus s vs. apexit 0.00 hs٭ ah plus vs. endofill 0.00 hs٭ ah plus vs. guttaflow 0.00 hs٭ apexit vs. endofill 0.00 hs٭ apexit vs. guttaflow 0.01 s٭ apexit vs. control 0.00 hs٭ endofill vs. guttaflow 0.00 hs٭ endofill vs. control 0.00 hs٭ guttaflow vs. control 0.00 hs٭ significant at level p<0.05 ٭ highly ٭ significant at level p<0.001. discussion successful root canal treatment not only means removal of microbial entity, but also preventing any future predilection of re‑infection and using biocompatible sealing agent (17). chemo-mechanical debridement is more likely to eradicate the bacteria that adhere superficially to the root canal walls. however, bacteria that infect dentinal tubules and remain in undebrided parts of the root canal system may cause recurrent infection (18). hence the ideal objectives of the root canal treatment are not only the elimination of infection, but also preventing reinfection of the treated root canal system especially in clinical situations of persistent or recurrent infections. microorganisms that survive chemomechanical debridement must be killed by sealers with sustained antibacterial activity and excellent adhesion to dentin. however the antimicrobial components of the sealer do not have selective toxicity against microorganisms; they also exert toxic effects on host cells. hil et al and huang et al (19,20) proposed that the ideal root canal sealer must have both good antimicrobial activity and low toxic effects on surrounding periapical tissue. in this study, agar diffusion test (adt) was used. this method which is the most widely used method for the identification of which material that has an antimicrobial effect within the root canal system. the result of adt are highly influenced by many variables such as the diffusion ability of the material across the medium, the selection of the agar medium and microorganisms, control and standardization of inoculation density, incubation and reading point of the zones of inhibition (6). antibacterial effect of four different types of root canal sealers was tested; guttaflow, a new gutta percha based material, the well described epoxy resin based ah plus, endofill as a zinc oxide eugenol based sealer and calcium hydroxide sealer known as apexit. anaerobic and facultative bacteria were chosen in the study because these types of microorganisms are usually minor constituents of primary infections, they have been found with higher frequency in cases of treatment failure. microorganisms, such as e. faecalis, s. aureus, ecoli and even c. albicans have been considered as the most resistant oral species and possible causes of failure of root canal treatment (21). e. faecalis is gram-positive facultative anaerobic cocci that are considered as a normal part of human intestinal flora. the high resistance of this type of bacteria to antibacterial action of the sealers used in this study could be explained by the ability of enterococci to survive very harsh environments including extreme alkaline ph (9.6) and salt concentrations. they resist bile salts, detergents, heavy metals, ethanol, azide, and desiccation. they can grow in the range of 10 to 45°c and survive a temperature of 60°c for 30 min (22). e. coli is gram-negative, facultative anaerobic and non-sporulating, rod shaped cells. j bagh college dentistry vol. 26(3), september 2014 analysis of antimicrobial restorative dentistry 33 while staphylococcus aureus is facultative anaerobic gram-positive coccal bacterium which is frequently found in the human respiratory tract . candida albicans is a diploid fungus that grows both as yeast and filamentous cells and a causal agent of opportunistic oral and genital infections in humans (23). the sealers evaluated in this study showed different inhibitory effects depending on the type of root canal sealers and bacterial species tested. endofill which is a zinc oxide eugenol based sealer had the maximum average zones of inhibition as compared to other tested sealers. findings of this study agree with studies that found large inhibitory zones produced by sealers similar to endofill against microorganisms such as s. aureus, c.albicans and e. faecalis (13). on the other hand, this material was the only effective sealer on the most resistant one (e.faecalis). the strong antibacterial effect of endofill may be related to the action of free eugenol liberated from the material which is a phenolic compound that is effective against mycotic cells in their vegetative (24). ah plus which is a new resin based sealer that showed absence of antimicrobial action against all tested species and this is in accordance with a previous study by andre et al and estela et al (25,26) who found ah plus to be ineffective against enterococcus faecalis and kapalan et al (27) who found ah plus to be ineffective against candida albicans. the low antimicrobial effect of ah plus against tested species might be ascribed to the minimal amount of formaldehyde released over time. the elimination of formaldehyde release from ah plus has made it an ineffective as antimicrobial sealant (28). apexit which is a calcium hydroxide based endodontic sealer that showed an antibacterial activity agaist staphylococcus aureus and e. coli, but no effect against e. faecalis and candida albicans. apexit was less effective than endofill and guttaflow, but more effective than ah plus. zhang et al (29) also showed poor antibacterial activity for apexit in comparison to six other sealers against e. faecalis. apexit induce antimicrobial action by releasing hydroxide ions oh־ and increasing ph levels above 12.5 creating unfavorable change for microbial growth which alter the integrity of the cytoplasmic membrane leading to a saponification reaction. the absence of any significant effect on candida albicans could lead to the conclusion that the release of hydroxyl ions is not sufficient to inhibit this yeast whose optimum growth ph is 5 (2). guttaflow is a cold, flowable, self-curing obturation material that combines gutta-percha and sealer into one injectable system. this material contains gutta-percha in particle form combined with a polydimethylsiloxane (7). guttaflow showed moderate inhibition on e.coli and s. aureus isolates while weak effect on e.faecalis and candida albicans. the antibacterial activity of gutta flow may be attributed to the preservative (nanosilver) present in this type of sealer which causes oligodynamic effect, in which, metal ions (silver) combine with sulfur groups and denature the cellular proteins (7). these results disagree with ivan, ines et al and lavanya et al (5, 30) who found no or minimum effect of guttaflow on inhibition of microbes. the controversial results could be explained by variation in conditions of the experiments such as the amount of material used, bacterial inoculation, test method, incubation period and interval times. as a conclusion; root canal sealers showed different inhibitory effects depending on their types and bacterial species tested. root canal sealers containing eugenol proved to be most effective against the microorganisms in the root canal. under the conditions of this in vitro study, endofill showed strong to moderate antimicrobial action against tested species while the new guttaflow filling material showed moderate to week effect in comparison with apexit and ah plus, indicating potentiality of endofill and guttaflow as an antibacterial agents. however, it is necessary to investigate other properties of the new material (guttaflow). none of the sealers tested totally inhibited microbial growth. thus, endodontic treatment must be performed under aseptic conditions, using powerful chemo-mechanical debridement, an intracanal dressing, adequate filling, and coronal restoration. references 1. sonja p, ribari ei, brekalo m. antibacterial activity of calcium hydroxide root canal sealer (apexit) in vitro study. acta stomat croat j 2001; 35: 475-7. 2. yazdan s, omid d, anoosheh j, golbarg k. in vitro evaluation of the antibacterial activity of three root canal sealers. iej 2010; 5: 1-5. 3. emre e, winter b, mustafa s. antibacterial activity of a new endodontic sealer against enterococcus faecalis. j can dent assoc 2006; 72(7): 637. 4. sahar s, mahsa e, shahriar s, hadi m. antimicrobial efficacy of ah-plus, adseal and endofill against enterococcus faecalisan in vitro study. african j microbiol res 2012; 6(5): 991-4. 5. ines w, angelika c, benjamin b, brita w. in 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of specific bacteria. inter endod j 1996; 29: 69-75. 24. zhejun w, ya shen, markus h. dentin extends the antibacterial effect of endodontic sealers against enterococcus faecalis biofilms. joe 2014; 40(4): 505–8 (ivl). 25. andre k, mickel t, nguyen, sami c. antimicrobial activity of endodontic sealers on enterococcus faecalis. j endod 2003; 4: 29. 26. estela b, pilar b, matilde r. antibacterial and antibiofilm activity of ah plus with chlorhexidine and cetrimide. j endod 2014; 40(7): 977-81. (ivsl). 27. kaplan a, dicca m, gonzalez m, maccki r, molgatini s. antimicrobial effect of six endodontic sealers: an in vitro evaluation. endodontic dental truamatol j 1999; 15: 42-5. 28. cohen b, pagnillo m, musikant b, deutsch a. formaldehyde from endodontic materials. j endod 1998; 88(9):37. 29. zhang h, shen y, ruse nd, haapasalo m. antibacterial activity of endodontic sealers by modified direct contact test against enterococcus faecalis. j endod 2009; 35:1051-5. 30. lavanya a, swaroop k, venkata s, chandra s, murali k, rama p, prathi venkata. an assessment of antibacterial activity of four endodontic sealers on enterococcus faecalis by a direct contact test: an in vitro study. isrn dentistry j 2012; article id: 989781. widad f.doc j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 40 evaluation of olive oil as a separating medium and its effect on some physical properties of processed acrylic resin denture base (a comparative study). part one akhlas zaid al-ta’ie, b.sc., m.sc. (1) widad abdul-hadi al-nakkash, b.d.s., h.d.d., m.sc. (2) farhan dakhil salman, b.sc., m.sc. (3) abstract back ground: during acrylic resin processing, the mold must be separated from the surface of the gypsum to prevent liquid resin from penetrating into the gypsum, and water from the gypsum seeping into the acrylic resin. for many years, tin foil was the most acceptable separating medium, and because it's difficult to apply, a tin-foil substitute is used. in this study, olive oil is used as an alternative to tin foil separating medium for first time, so the aim of the study was to evaluate its effect as a separating medium on some physical properties such as (surface roughness, water sorption and solubility) of acrylic resins denture base comparing it with those processed using tin-foil and tin foil substitute such as (cold mold seal) separating medium. materials and methods: one hundred forty two acrylic resins samples (124) were prepared falling in two main groups: [heat and cold-cured acrylic denture base resins ], for each group three types of separating medium were used and five tests (10 samples) for each test were carried out , and (4) samples for the chemical composition. result: from the result obtained, tin foil is one of the most satisfactory separating media in getting the best properties when using it as a separating medium, while, a statistically no-significant difference have been noticed between olive oil and cold-mold seal samples concerning physical and mechanical properties of tested groups. infrared spectroscopy analysis showed that, no changes were found in the chemical composition of both heat and coldcured acrylic resins denture base after using olive oil as a separating medium. conclusion: lastly, from the results of this study it may be concluded, that olive oil may be used as a substitute for tin foil and cold – mold seal separating medium in processing both heat and cold – cure acrylic resin denture base. key words: acrylic resin, separating medium, olive oil physical properties. (j bagh coll dentistry 2015; 27(3):40-49). introduction separating medium is a coating applied to a surface serving to prevent a second surface from adhering to the first, or a material, usually applied on an impression to facilitate removal of the cast (1) .if the surface of the mold is not coated with a separating material, it will be found, that a layer of gypsum impregnated with polymer remains attached to the surface of the denture and is extremely difficult to remove (2). then it is an improperly contoured, and hence it leads to produces an unaesthetic and poorly fitting denture base (3). therefore; separating medium must be applied to the surface of the mold. many authors consider that tin foil is the best separating medium, however it is difficult to apply, tedious, and time-consuming. as a result, the solution is sometimes referred to as a tin foil substitute have been developed (4). a tin foil substitute is a film forming material that is painted on the mold surface thus preventing absorption the liquid acrylic denture base resin and at the same time sealing pores of the artificial stone (5). (1)lecturer. college of health and medical technology. (2)professor. department of prosthodontics. college of dentistry, university of baghdad. (3)assistant professor. college of health and medical technology. nowadays, tin foil substitute can be used successfully if all wax residue is carefully cleaned from the pores of the stone and the tin foil substitute is carefully applied (3).a variety of materials can be used as a tin foil substitute, the most popular of separating agents are watersoluble alginates which produce a very fine film on the applied surface (6). this study was designed to evaluate olive oil as a separating medium and its effect on some physical and mechanical properties of the processed acrylic resin denture base when compared to those processed with tin foil and alginate mold seal (cold-mold seal) separating media. materials and methods metal pattern preparation two different metal patterns were constructed with four dimensions to save time and effort (figure 1). dimensions and shape of each metal pattern were made according to the required tests. j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 41 samples grouping a total of 124 samples were prepared and used during this study. the samples were divided into (2) groups (according to the types of acrylic resin). each group consisted of (62) samples, and these (122) samples were subdivided according to the types of separating medium used in curing process. these separating media were of (21) samples from tin foil, (20) samples from coldmold seal, (21) samples from olive oil. and each separating medium were subdivided (according to the tests) used in this study, (10) samples were made for each of the following tests except (4) samples for testing the chemical composition. 1(10) samples for surface roughness. 2(10) samples for water sorption and solubility. 3(4) samples for chemical composition during preparation of the mold, the conventional flasking technique was followed. the lower portion of the dental flask was filled with dental type iii stone (elite model, italy) mixed according to the manufacturer instructions (i.e./p ratio is 25ml/100g); a layer of stone mix was placed on metal block to avoid trapping of air when inserting the metal block into the stone mix after coating with separating media. after stone was set, both the stone and metal patterns were coated with separating media. the upper half of the flask was then positioned on top of lower portion and filled with stone, with vibration to get rid of the trapped air. stone was allowed to harden for 60 minutes before the flask was opened. the metal patterns were invested each time when the samples were to be prepared. the flask was then opened and metal patterns were removed from the mold carefully. when using the separating medium such as tin-foil (dentaurum, pforzhein), it was adapted to the stone surface in each half of the flask, with fingers. while, in case of using cold-mold seal (11b, switzerland), and olive oil (al-ghassuon company iraq), separating medium, (2cc) of olive oil was measured by using a disposable syringe and applied onto the stone surface in the flask, with a fine brush (no.0) (7). pink heat and cold cured acrylic resin (triplex hot ivoclar vivadent, liechtenstein) was used to fabricate the samples in this study, following the manufacturer’s instructions of powder/ liquid ratio by volume. heat-cured acrylics were mixed (3:1), while the cold-cured acrylic was (2.5:1) by volume, and then left to reach the dough phase at room temperature (approximately 23°c). after filling the mold with the dough, the flasks were fitted and pressed together in a hydraulic bench press for (5) minutes before polymerization process. curing was carried out by placing the clamped flask (hanau engineering co.usa) in a water bath and processed by heating at 74ºc for about an hour and half. the temperature was then increased to the boiling point for 30 minutes (8). after completing the curing, the flask was allowed to cool slowly at room temperature for 30 minutes. followed by, complete cooling of the flask with tap water for 15 minutes before deflasking. the acrylic patterns were then removed from the mold. in case of curing the cold cure acrylic resin, flasks containing the acrylic resin dough were left in a bench press curing it for 2 hours at 23cº ± 5cº (9). an acrylic bur was used to remove all flashes of acrylic followed by 120-grain size sand paper with continuous water-cooling (to prevent over heating) in order to get smooth surface (except the samples that are used for surface roughness test). polishing was accomplished using bristle brush and rag wheel with pumice (steribim plus, germany) using dental lathe polishing machine (derotor, quayle dental q.d, england), (low speed, 1500 rpm) till glossy surface was obtained, the final measurements of the samples were obtained using the vernier (rostfre; germany). tests utilized examine properties of the cured material infrared spectroscopic analysis asamples preparation from metal disc (4) samples of both heat and cold-cured acrylic resin (2 for each) were prepared with dimensions of (50 ± 1mm in diameter and 0.5 ± 0.1mm thickness). btest equipment and procedure one type of infrared spectrophotometer were used (pye-unicam sp3100).this instrument is a double beam spectrophotometer operating in the region (4000-200cm-1) was found to be adequate for the observation of the structures of acrylic resins denture base (10). b a figure 1: metal patterns. asurface roughness test, bwater sorption, solubility and infrared spectroscopy tests. j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 42 figure 2: infrared spectrophotometer device to examine olive oil by this instrument, compressed sample of olive oil between two kbr plates (potassium bromide) in a disc holder to spread out as a thin film. this method was called mull technique used in the region of (4000200cm-1). a second method called thin film technique. this method used different solvents in polarity to dissolve the samples of heat and coldcured acrylic resins denture base processed against olive oil as a separating media. toluene solvent, was the mostly used solvent to dissolve these samples (11). after dissolving all samples with toluene, transfer the mixture into glass petri dishes leaving the mixture of these samples for an overnight thus allowing the solvent toluene to evaporate leaving the remaining materials as a thin film (transmittance thin film), this thin film was tested in the region of (4000-200cm-1).the same procedure was repeated one time for heat and cold-cured acrylic resin denture base only. surface roughness test asamples preparation for surface roughness test, 60 samples of both heat and cold-cured acrylic resins denture base (30 for each) were prepared from metal pattern with dimensions of (65x62x64x61) mm. with 3mm. thickness. test equipment and procedure a profilometer device (talysurf 4, talyor hobson, uk, england) used to measure the surface roughness of a sample. the surface of the sample must be very flat, fixed to the horizontal base of the profilometer. this device is supplied with a surface analyzer (sharp stylus) to trace the profile of the surface irregularities and recording all the peaks and recesses characterizing the surface (figure 3) all samples of surface roughness were not polished after deflasking. figure 3: profilometer device (surface roughness tester) water sorption test asamples preparation from metal disc, 60 samples of both heat and cold-cured acrylic resins denture base (30 for each) were prepared with dimensions of (50 ± 1mm in diameter and 0.5 ± 0.1 mm in thickness) (8). btest equipment and procedure the samples were dried in a desiccator containing silica gel (china) (figure4: a). the desiccator was stored in an incubator(gllenbamp, england) at a temperature of 37ºc ± 2ºc for 24 hours, removed to similar desiccator at room temperature for one hour, after which the samples were weighed using a digital balance (hr-200, a&d company limited, international division). (figure4: b). this cycle was repeated until the weight loss of each disk was not more than 0.5 mg in every 24 hour period; this was considered as condition mass .the samples were then immersed in distilled water (al-mansour co. iraq) at 37ºc ±1ºc. for 7 days. after that the samples were removed from the water with tweezers, wiped by a clean dry hand towel, until free from visible moisture, waved in the air for 15 seconds and weighed one minute after removed from the water. the value for water sorption was calculated for each disc in (mg/cm2) (8). figure 4: a-samples drying in desiccators over silica gel. bdigital balance a b j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 43 solubility test after the final weighing were described in the water sorption test, the samples were reconditioned to constant weight in the desiccator at 37ºc ± 2ºc as was done in the water sorption test previously. the value of solubility was determined for each sample according to the equation below: solubility (mg/cm2) = conditioned mass (mg) reconditioned mass (mg) surface area (cm2) statistical analysis the usual statistical methods were used in this study to analyze and assess our results , included descriptive statistics:(arithmetic mean, standard deviation (s.d.), minimum, maximum, graphical representation by bar-chart)and inferential statistics (one way analysis of variance (anova), lsd (least significant difference test). results descriptive and inferential statistics of some physical properties such as (surface roughness, water sorption and solubility) of heat and coldcured acrylic resins denture base samples which are invested in stone mold as influenced by different types of separating media (tin foil, coldmold seal, and olive oil), and a comparison between the results of them all to evaluate the olive oil as a separating medium. infrared spectroscopy is used to examine the chemical composition changes of heat and coldcured acrylic resins denture base when using olive oil as a separating media. infrared spectroscopy analysis table (1) shows, the spectral data of acrylic resin denture base after processed against olive oil as a separating medium, acrylic resin denture base, and olive oil. the results shows that there are some bands presented or has disappeared in spectra which can help in the identifications of three samples of (acrylic resin denture base after processed against olive oil as a separating media, acrylic resin denture base, and olive oil )as in (figure 5) and (figure 6). by the assignment of bands for three samples, it seems that, the same bonds in acrylic resin denture base, and olive oil structures. while there are many bonds has just appeared in spectrum of acrylic resin denture base and does not appear in spectrum of olive oil. and also there is a single mode which appears in spectrum of olive oil and cannot be seen in spectrum of acrylic resin denture base, and acrylic resin denture base processed against olive oil as a separating medium which assign to the deformation and rocking modes (table 1). this evidence is to prove that olive oil is not grafted in acrylic resin denture base through the two processes heat and cold-cured acrylic resins denture base samples (10,12). table 1: infrared assignment of acrylic resin denture base when processed against olive oil as a separating medium, acrylic resin denture base, and olive oil assignment olive oil wave no.cm-1 acrylic resin wave no. cm-1 acrylic processed against olive oil wave no.cm-1 -oh(stretching) 3480(m.) 3440(m) -ch2(stretching) 3080(m.) 3040(v.s.) 3040(v.s.) -ch(stretching) 3000(v.s.) 3000(v.s.) -ch2(stretching) (ch3 stretch olive oil) 2980(v.s.) 2980(v.s.) 2980(v.s.) -ch2(stretching) 2880(s.) 2880(s.) 2885(v.s.sh.) c=o(stretching) 1750(s.) 1750(v.s.) 1750(v.s.) c=c(stretching) 1650(m.) 1680(s.sh.) =ch2(deformation) 1500-1440(v.s.) 1500-1480(v.s.) -ch3(deformation) 1470(m.) -ch3(deformation) 1460(w.sh.) -oh(deformation) 1400(s.) 1420(v.s.) -oh(deformation) 1300(v.s.) 1300(v.s.) c-o(deformation) 1210(m.sh.) 1220(v.s.) 1200(v.s.) -ch3(deformation) 1180 -ch2(deformation) 1120 =ch2 (rocking) 1080(s.) 1060(s.) -ch (wagging) 1000(w.sh.) 1000(m.sh.) =ch2 (wagging) 940(w.) 950(m.) -ch3 (rocking) 900(w.) =ch2 (rocking) 850(w.) 850(m.) c=o(deformation) 750(w.) 760(m.) 740(m.) m = medium, s = strong, w = weak, v = very shoulder j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 44 surface roughness test result mean values, standard deviation (sd) and standard error (se) are presented in (table 2) and (figure7) for surface roughness test. the values of surface roughness varied according to the types of separating medium that are used. the highest mean surface roughness value was obtained in heat-cured acrylic resin denture base and cold-mold seal separating media (0.0289), while the lowest mean surface roughness value was obtained in heat-cured acrylic resin denture base and tin-foil separating media (control group) (0.0166). table (3) represents one way anova by lsd multiple comparison test; showed that there was a significant difference at (p<0.05) between different types of separating medium except for a non-significant difference at (p>0.05) between heat-cured acrylic resin-tin foil separating media (control group) and cold-cured acrylic resin-tin foil separating media. heat-cured acrylic resincold mold seal separating media and heat-cured acrylic resin-olive oil separating media, coldcured acrylic resin-cold mold seal separating media, cold-cured acrylic resin-olive oil separating media,. heat-cured acrylic resin-olive oil separating media and cold-cured acrylic resincold resin -mold seal separating media, cold-cured acrylic resin-olive oil separating media. cold cured acrylic resin –cold mold seal separating media and cold –cured acrylic resin –olive oil separating media. table 2: mean and standard deviation, standard errors for surface roughness of heat and coldcured acrylic resins denture base as influenced by different types of separating media. statistics heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o no. 10 10 10 10 10 10 mean 0.0166 0.0289 0.0269 0.0186 0.0279 0.0273 sd 0.00467143 0.00409471 0.00395671 0.00512510 0.00310734 0.00290784 se 0.00148 0.00129 0.00125 0.00162 0.000983 0.000920 * t.f= tin-foil, ** c.m.s= coldmold seal, ***o.o= olive oil figure 7: bar chart show mean values for surface roughness (µm) of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. 0 0.005 0.01 0.015 0.02 0.025 0.03 m ea n of s ur fa ce r ou gh ne ss t es t ( µm ) heat-tin foil heat-cold mold seal heat-olive oil cold-tin foil cold-cold mold seal cold-olive oil figure 5: infrared spectra of olive oil, heat-cured acrylic resin, and heatcured acrylic resin processed against olive oil as a separating media figure 6: infrared spectra of olive oil, cold-cured acrylic resin, and cold-cured acrylic resin processed against olive oil as a separating media j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 45 table 3: anova then lsd least significant difference for surface roughness of heat and coldcured acrylic resins denture base as influenced by different types of separating media. anova=s groups heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o heat-cured acrylic t.f. s s n.s s s c.m.s n.s s n.s n.s o.o s n.s n.s cold-cured acrylic t.f s s c.m.s n.s o.o p<0.05 = s= significant, p>0.05= n.s.=non significant, * t.f= tin foil, ** c.m.s= cold-mold seal , *** o.o= olive oil water sorption test result mean values, standard deviation (sd) and standard error (se) are presented in (table 4) and (figure8) for water sorption test. the values of water sorption varied according to the types of separating medium that are used. the highest mean water sorption value was obtained in coldcured acrylic resin denture base and olive oil separating media (0.641100), while the lowest mean water sorption value was obtained in heatcured acrylic resin denture base and tin-foil separating media (control group) (0.518200). table (5) represents one way anova by lsd multiple compression test, showed that there was a significant difference at (p<0.05) between different types of separating medium, except for a non-significant difference at (p>0.05) between heat-cured acrylic resin-tin foil separating media (control group) and cold-cured acrylic resin tinfoil separating media. cold-cured acrylic resincold mold seal separating media and cold-cured acrylic resin-olive oil separating media. table 4: mean and standard deviation, standard errors for water sorption of heat and coldcured acrylic resins denture base as influenced by different types of separating media. statistics heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o no. 10 10 10 10 10 10 mean 0.518200 0.547600 0.587500 0.521600 0.628900 0.641100 sd 0.00451664 0.00894676 0.00990230 0.00656929 0.0220480 0.0341742 se 0.00143 0.00283 0.00313 0.00208 0.00697 0.0108 *t.f= tin-foil, **c.m.s= cold-mold seal, ***o.o= olive oil figure 8: bar chart show mean values for water sorption (mg/cm2) of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 m ea n of w at er s or pt io n te st (m g/ cm 2) heat-tin foil heat-cold mold seal heat-olive oil cold-tin foil cold-cold mold seal cold-olive oil j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 46 table 5: anova then lsd least significant difference for water sorption of heat and cold-cured acrylic resins denture base as influenced by different types of separating media anova=s groups heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o heatcured acrylic t.f. s s n.s s s c.m.s s s s s o.o s s s coldcured acrylic t.f s s c.m.s n.s o.o p<0.05 = s= significant, p>0.05= n.s=non significant, *t.f= tin foil, **c.m.s= cold-mold seal, ***o.o= olive oil solubility test results mean values, standard deviation (sd) and standard error (se) are presented in (table 6) and (figure9) for solubility test. the values of solubility varied according to the types of separating medium that are used. the highest mean solubility value was obtained in cold-cured acrylic resin denture base and olive oil separating media (0.0527), while the lowest mean solubility value was obtained in heat-cured acrylic resin denture base and tin-foil separating media (control group) (0.0209). table (7) represents one way anova by lsd multiple compression test, showed that there was a significant difference at (p<0.05) between different types of separating medium, except for a non-significant difference at (p>0.05) between heat-cured acrylic resin-cold mold seal separating media and heat-cured acrylic resin-olive oil separating media. cold-cured acrylic resin-cold mold seal separating media and cold-cured acrylic resin-olive oil separating media. table 6: mean and standard deviation, standard errors for solubility of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. statistics heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o no. 10 10 10 10 10 10 mean 0.0209 0.0277 0.0289 0.0428 0.0501 0.0527 sd 0.000598517 0.00191207 0.00272374 0.00101784 0.00225920 0.00148507 se 0.000189 0.000605 0.000861 0.000322 0.000714 0.000470 *t.f= tin-foil, **c.m.s= cold -mold seal, ***o.o= olive oil figure 9: bar chart show mean values for solubility (mg/cm2) of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. 0 0.01 0.02 0.03 0.04 0.05 0.06 m ea n of s ol ub ili ty t es t ( m g/ cm 2) heat-tin foil heat-cold mold seal heat-olive oil cold-tin foil cold-cold mold seal cold-olive oil j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 47 table 7: anova then lsd least significant difference for solubility test of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. anova=s groups heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o heat-cured acrylic t.f. s s s s s c.m.s n.s s s s o.o s s s cold-cured acrylic t.f s s c.m.s n.s o.o p<0.05 = s= significant, p>0.05= n.s=non significant, *t.f= tin foil, **c.m.s= cold-mold seal, ***o.o= olive oil discussion among other factors coefficients, separating medium must be used, due to its effect on the physical properties of the processed acrylic denture base materials. in this study, olive oil is used as a separating medium in the process of curing both heat and cold-cured acrylic resins denture base. infra-red spectroscopy analysis from the infrared spectroscopic analysis of the different materials used in this study, including (acrylic resins denture base processed against olive oil as a separating medium, acrylic resins denture base only, and olive oil), showed no differences in the spectrum of the composition of both heat and cold-cured acrylic resins denture base after processing in stone mold lined with olive oil separating media with no changes in the bonds, no additional bonds of olive oil in the processed acrylic resins denture base are detected, that means no reaction between olive oil and acrylic resin denture base (heat and cold) , no grafting of olive oil in heat and cold-cured acrylic resins denture base was found after processing (12). surface roughness the result of the present study showed that, the highest mean value of surface roughness was obtained in heat-cured acrylic samples lined with cold-mold seal separating media, while olive oil separating media showed less surface roughness compared with cold-mold seal separating medium, also all samples of cold-cured acrylic resin denture base showed similar results of heatcured acrylic resin denture base, and olive oil showed a comparable result concerning surface roughness. this could be related to the lining provided by the tin-foil substitute to make the surface smoother. this agreed with zani and vieira (13). other explanation can be related to soaking gypsum dies or casts in different oils that makes the surface smooth. this is in agreement with other researches (4,7). a statistically nosignificant difference between cold-mold seal and olive oil separating medium. while a significant difference was found between tin foil and cold-mold seal separating media on one hand, tin foil and olive oil separating media on the other hand for both heat and cold-cured acrylic resins denture base. this could be due to the bleaching or the clouding which is related to the penetration of the outer layers of resin by molecules of water. this finding is in agreement with many findings (7,14,15).they stated that examination of the specimens revealed that acrylic resin when processed against tin foil substitute showed blanching and fogging and in some cases adherence of plaster particles. other explanation could be related to the fact alginate film is not completely water-repellent; the cured denture base resin may show some slight opacity. in addition, the alginate films cause stresses with the surface of the denture and this may lead subsequently to crazing, this agreed with others (2,6,16,17). water sorption the result in tested samples of heatcured acrylic resin denture base processed against tin foil separating media showed lowering in the mean values of water sorption when compared with those samples processed against coldmold seal and olive oil separating media. this could be related to that, heatcured materials processed against tin foil are substantially dry at the end of the curing cycle, while those processed against tin foil substitute approach saturation during curing. this result agreed with fairhurst and ryge (14). on the other hand, tested samples of coldcured acrylic resin denture base showed higher mean values of water sorption when compared with those samples of heat-cured acrylic resin denture base. similar results were obtained by j bagh college dentistry vol. 27(3), september 2015 evaluation of olive restorative dentistry 48 wozniak et al. (18) who pointed out that cold-cured acrylic stained more than heat-cured acrylic, which may be attributed to the greater porosity of cold-cured acrylic resulting in an increased surface area exposed to solutions. this explanation agreed with bevan and earnshow (17) when they recorded the water sorption of (trevalon) heat and (detryssc) cold-cured acrylic as (0.58 and 0.60)mg/cm2 respectively. the mean values for water sorption by heat and cold-cured acrylic denture base resins processed against olive oil separating media are within the limits given by ada (8), the gain in weight by the resin must not be greater than 0.7 mg/cm2. statistically no significant difference was found between samples processed against coldmold seal separating media and those samples processed against olive oil as a separating media. while a significant difference in water sorption between tested samples for both heat and coldcured acrylic resins denture base processed against tin foil separating media and those processed against cold-mold seal and olive oil separating media. this may be related to that tin foil substitutes films which are permeable to water allowing it to pass from the gypsum mold and enter the acrylic resin denture base during the process unlike tin foil. this explanation agreed with many researches (7,17,19,20) and disagreement with fairhurst and ryge (21). they pointed that resins processed in mold lined with tin foil substitute separating media is saturated with water during processing and consequently does not absorb more water during storage in it. solubility from tested samples of heat-cured acrylic resin denture base showed lowering in the values of solubility when compared with those samples of cold-cured acrylic resin denture base. this could be related to losing more weight due to lower degree of polymerization of cold-cured acrylic and the presence of higher contents of residual monomer which make higher solubility. this explanation agreed with other findings (4,7,2224) and olive oil as a separating media showed a comparable result regarding solubility test. statistically no significant difference between samples processed against cold-mold seal separating media and those samples processed against olive oil separating media. while there was a significant difference between samples processed against tin foil and cold-mold seal separating media on one hand, tin foil and olive oil separating media on the other hand. this could be related to the degree of sealing supplied by each separating media provided. this result agreed with sweeney (25) who found that, heatcured denture base resin specimens prepared in mold lined with tin foil lost less weight on drying than the specimens prepared in molds lined with alginate separating medium. several workers observed similar results (14,17). as conclusions; 1tin foil is the most ideal type of separating medium for lining molds during the process of both heat and cold-cured acrylic resins followed by olive oil and cold-mold seal separating medium regarding surface roughness, water sorption, solubility 2infrared spectroscopic analysis shows no changes in the composition of the processed both heat and cold-cured acrylic resins denture base against olive oil separating medium. 3comparable results were found between coldmold seal and olive oil separating medium regarding (surface roughness, water sorption, solubility) of processed acrylic resins denture base. 4finally, from the results obtained, it can be concluded that olive oil forms a satisfactory material for being used as a separating medium of process acrylic resins denture base. references 1glossary of prosthodontic terms. the academy of prosthodontics: mosby; 2005. 2anderson jn. applied dental materials. 4th ed. london: black well scientific publications; 1972. 3rahan ao, ivanhoe jr, plummer kd. textbook of complete dentures. people's medical publishing house; 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34: 306-12. 20phillips rw. skinner’s science of dental materials. 9th ed. philadelphia; wb. saunders co.; 1989. 21fairhurst cw, ryge g. effect of tin-foil substitutes on the strength of denture base resin. j prosthet dent 1955; 5(4): 508-13. 22stafford gd, bates jf, huggett r, handly rw. a review of the properties of some denture base polymers. j dent 1980; 8(4): 292-4. 23skinner ew, phillips rw. the science of dental materials. 5th ed. philadelphia: wb saunders co.; 1960. p. 31-57. 24faraj saa. the properties of acrylic type denture base materials. a master thesis, university of sheffield, 1977 25sweeney wt. vernonite work bench 1947; 6(6): 272. الخالصة جبسي من ناحیة ثانیة من القالب الجبسي من ناحیة ودخول الماء خالل عملیة بلمرة قاعدة الطقم االكریلي، یجب فصل سطح القالب من الجبس لمنع سائل االكریل من اختراق القالب ال في ھذه . لمعدنیةمنذ عدة سنوات كانت رقائق القصدیر المعدنیة ھي االكثر استعماًال كمادة عازلة ولصعوبة استخدامھا، تم استعمال بدیل رقائق القصدیر ا.لطقم االكریليالى قاعدة ا خشونة ( سة تأثیرھا كمادة عازلة على بعض الخواص الفیزیاویة مثل الدراسة تم استخدام زیت الزیتون كبدیل لرقائق القصدیر المعدنیة وألول مرة وتم تقییم ھذه المادة وذلك بدرا صودیوم (لقاعدة الطقم االكریلي الراتنجي ومقارنتھا مع تلك المبلمرة بأستعمال رقائق القصدیر المعدنیة وبدیل رقائق القصدیر المعدنیة ) السطح ، خاصیة امتصاص الماء ، والذوبان وكل مجموعة تحتوي على ثالثة انواع من المواد ) االكریلك الحار والبارد(موزعة على مجموعتین رئیسیتین ) 124(واربعة واربعون عینة اكریلك مائتان.كمواد عازلة) ختم القالب اظھرت النتائج في ھذه .ر الكیمیائيعینات لفحص التغیی) 4(عینات ، ما عدا ) 10(العازلة المستعملة في ھذه الدراسة كما واجریت اختبارین على كل نوع لكل اختبار تم تجھیز ضلة ، وذلك المكانیة الحصول على افضل النتائج عند استخدامھا كمادة عازلة ، كما انھ لم یكن ھنالك اي الدراسة ان رقائق القصدیر المعدنیة ھي واحدة من اكثر المواد العازلة المف ت اظھر.فیما یتعلق ببعض الخواص الفیزیائیة للمجامیع االختباریة ) صودیوم ختم القالب ( فروقات احصائیة معنویة ملحوظة بین مادة زیت الزیتون وبدیل رقائق القصدیر المعدنیة واخیرًا ، فأنھ لتوفر زیت .كمادة عازلة نتائج تحلیل االشعة تحت الحمراء انھ لیس ھناك اي تغییر في التركیب الكیمیائي لعینات الراتنج الحار والبارد عند استخدام زیت زیتون د كمادة عازلة فأنھ یمكن ان یساھم استعمال ھذه المادة في التوصل الى نتائج الزیتون وسھولة الحصول علیھ من االسواق وكذلك سھولة استخدامھ مع الراتنج االكریلي الحار والبار .جیدة عند بلمرة الراتنج االكریلي بنوعیھ raghda.doc j bagh college dentistry vol. 27(1), march 2015 effect of sodium restorative dentistry 70 effect of sodium fluoride addition as a disinfectant on some properties of alginate impression material alaa m. hussian, b.d.s. (1) raghdaa k. jassim, b.d.s, m.sc., ph.d. (2) abstract background: impression materials, impression trays, and poured stone cast have been said to be the main source of cross infection between patients and dentists. however, it was observed that disinfection of the impression is not performed systematically in routine dental practice. disinfection of alginates either by immersion or spray technique was found to cause dimensional inaccuracies, although with proper disinfection of alginates there were small dimensional changes. a variety of fluoride releasing products designed for topical use is currently available. following their use, varied amount of fluoride is systemically absorbed depending on the fluoride concentration and the manner of its use. the objective of this study was to evaluate the effect of addition (0%, 0.25%,0.5%,1%, 2%, 3%, 4% ) of (naf) as a self-disinfection to alginate impression material powder and its effect on setting time, tear strength, dimensional change and accuracy of alginate impression materials. materials and methods: a total no. of (700) specimen were used in this study.these specimens were divided into (5) main groups according to the tests used. each of the four main groups contain (70) specimen divided into 7 subgroups (ten specimens to be tested for each (7)concentrations which is composed of six percentages of nafwith alginate powder (0.25%,0.5%,1%, 2%, 3%, 4% )and one for control (0% naf) , while the fifth group (microbiological test) contain 420 specimen were divided between streptococcus mutans and candida albicans as (120) specimen for each one that was subdivided into three subgroups (specimens taken before impression casting, specimensafter pouring of alginate with stone andspecimens of stone were taken from the casts) in which it contain the same subgroups of the other concentrationsof (naf) to test its efficacy against (streptococcus mutans and candida albicans). results: tear strength for all experimental impression materials was greater than those of the control products. there were no statistically significant differences between the dimensional change tests and also reproduction of detail test.with regard to setting time of the impressions, statisticallyreduction were seen between the control and experimental groups of alginate impression materials that contain (naf). self-disinfection of alginate impression material containing naf showed a significant reduction in the count of cell forming unit of microorganisms immediately after impressions were made. conclusion: in cooperation of specific concentrations of (naf) as a disinfectant in alginate dental impression produced a significant reduction of contamination, also they caused non-significant effect on dimensional stability, detail reproduction and significant increase in tear strength. therefore it is recommended as step in preventing cross contamination. keywords: alginate, naf, candida albicans, streptococcus mutans. (j bagh coll dentistry 2015; 27(1):70-76). introduction dental alginates were the first chemical-set elastic polymer impression materialto be used in dentistry (1). impression disinfection is an integral part to prevent cross infection between dentists, dental office staff, dental technicians and patients. it is well documented the dental impressions harbors harmful bacteria due to their contact with blood and saliva (2). some of this bacterium can survive outside oral fluids for long time. dental cast obtained from these infected impressions can transmit pathogens to dental laboratory, exposing dental laboratory personnel for cross infection (3). selected disinfectant should not adversely affect the dimensional stability of the impression and physical properties of subsequent dental cast. the practice of impression cross infection control in dental practice is a cause of concern. (4,5). irreversible hydrocolloid materials are widely used for both diagnostic and definitive impression procedures. (1) master student. department of prosthodontics, college of dentistry, university of baghdad. (2) assist. professor, department of prosthodontics, college of dentistry, university of baghdad. it has been reported that irreversible hydrocolloid impression carries two to five times more microorganisms than elastomers (6). the entire dental staff is routinely exposed to numerous viral and bacterial pathogens that have the potential to cause serious illness. contamination of dental impressions with varying amounts of blood, saliva and debris is a routine occurrence in the dental operatory. therefore these impressions must be considered the potential to transmit the serious disease to all dental personnel who routinely handle them. a major concern is the problem of disinfecting dental impressions, particularly irreversible hydrocolloid impressions; these materials are susceptible to dimensional distortion during disinfection because of their hydrophilic nature (7). disinfection of the dental impressions is the most important barrier system in infection control (8). although, sterilization is more effective than disinfection, dental impressions cannot be subjected to sterilization as it is associated with significant dimensional changes. (9).bergman found that immersion of alginate impressions in j bagh college dentistry vol. 27(1), march 2015 effect of sodium restorative dentistry 71 disinfectant solutions for one hour caused unacceptable changes in surface detail and accuracy. when the alginates were sprayed with the disinfectant solutions, all had acceptable dimensional stability; however, only surfaces sprayed with cidex, technosept, and chloramine showed no deterioration in surface detail (10).to avoid dimensional inaccuracies associated with disinfection process, manufacturers have incorporated disinfectant materials into the alginate. a disinfectant material that is added to the alginate must be efficient enough without affecting the clinically important properties and the castability of the recorded impression. antimicrobial compounds which are water soluble and easily dispersible materials such as quaternary ammonium compounds, bisquanidine compounds, dialkyl quaternary compounds, quinoline compounds, substituted phenols, chlorhexidine, didecyldimethyl ammonium chloride, and a mixture of these materials are generally employed. (11). materials and methods a total no. of (700) specimen was used in this study.these specimens were divided into (5) main groups according to the tests used which include: 1. setting time test. 2. dimensional change test. 3. dimensional accuracy test. (detail reproduction) 4. tear strength test. 5. bacteriological test: a) cell count test (cfu/ml) for streptococcus mutans. b) cell count test (cfu/ml) for candida albicans. each of the four main groups contain 70) specimen divided into 7subgroupswhich is composed of six percentages of naf with alginate, one for control (0% naf) while the fifth group (bacteriological test) contain 40 specimen were divided between streptococcus mutans and candida albicans, as specimen of alginate used before impression casting, after pouring of alginate with stone and specimen of stone were taken from the casts. a. setting time test the setting time were tested in air conditioned laboratory room with temperatures of (23 ±2) °c, at 40% ± 10% relative humidity, measuring the final setting time has been done using digital vichatronic apparatus as shown in (fig.1). figure 1: vichatronic apparatus b. dimensional change test dimensional change test was measured using the protocol for dental elastomeric impression materials, as described in american national standard institute/american dental association specification no. 19 (12). a flat glass plate was placed over the mold and pressed the impression material firmly against the die assuring a positive metal to metal contact between the mold and the die then a metal flat weight of 1 kg simulating the operator’s finger pressure on a tray was placed over the glass plate as shown in fig.(2). the impression material was separated from the test block and placed under a dino-lite digital measuring microscope.measurements have been done from the inner profile of the two cross horizontal lines of the stainless steel die and compare it to the same lines copied from the impressions of all percentages of naf, and control alginate (figure 3). figure 2: flat glass plate pressed over the mold j bagh college dentistry vol. 27(1), march 2015 effect of sodium restorative dentistry 72 figure 3: dino-lite imaging of the samples with its calibrations. impression was inspected visually without magnification and the accepted impressions were those that passed the ansi/ada specification for detail production which reproduced the full length of the 75μm-wide line for the alginate without interruption, according to ansi/ada specification no.18. , detail reproduction of stone casts stone poured inside the gypsum mold on a vibrator and wait to set, then removed from the mold and inspected, according to the following scoring system: (13). 1rating (1) well-defined, sharp detail and continuous line. 2rating (2) continuous line but with some loss of sharpness. 3rating (3) poor detail or loss of continuity of line. 4rating (4) marginally or completely not discernible line. for grading purposes the 75μm wide lines were assessed for alginate assessment of surface quality. c. tear strength test the mold used was prepared with v-notch according to the iso 1563. the sample was held in place with pneumatic clamps and extended at a constant rate of 5 n load cell, the force at failure was measured in an instron testing machine at a crosshead speed of 500 mm/min. (14). d.microbiological tests microbiological tests: after proper sterilizations andpreparation of mitis-salivarius bacitracin agar (msb agar) media, isolation of mutans streptococci from salivary sample were performed under the conditionsfollowing the criteria described by tenovuo (15). the plates were incubated anaerobically using a gas pack for 48 hr at 37o c, then aerobically for 24 hr at room temperature.as shown in (fig.4) figure 4: mutans streptococci on msba. isolation and purification of candida albicans been done after preparation of sabouraud dextrose agar (sda) from patient with denture stomatitis, swab was cultured on sabourauds dextrose agar (sda) and incubated at 37°c for 72 hr and then kept at 4°c for further investigation, (16) (fig. 5). figure 5: candida albicans colonies on sda. the colonies of mutans streptococci and candida albicans were determined according to: 1. morphological characteristic. (17). 2. gram’s stain. (18). 3. biochemical tests (19): acatalase production test. bcarbohydrate fermentation test. 4. vitek 2 systems product information. (20). the addition of naf to alginate powder was done by geometric mixing procedure. (21). experimental method the procedure start with contamination of brass model by immersing it in suspension of microorganismthe standard inoculums were prepared to match the turbidity of 1.5×108cfu/ml (equivalent to 0.5 mcfarland) using mcfarland standard device, the brass model was with a flat polished surface divided into twelve 10×10mmsquare separated by 2mm deep grooves (fig. 6) streptococcus mutans colonies j bagh college dentistry vol. 27(1), march 2015 effect of sodium restorative dentistry 73 figure 6: brass master model with its aluminum tray this model was subjected for 5 min in a suspension of either candida albicans or streptococcus mutans, standardized with a mcfarland standard device, after removal from the suspension; the models were shaken and placed on a sterile paper for 1 min before the impressions were taken. (22). impression was taken to the mold, after complete setting, brass model has been removed from the impression. a flat square section of the impression material was cut off and removed with a number 10 surgical blade as slices with 2 mm thickness as shown in (fig.7). (4). figure 7: alginate sample taken from the impression each sample (impression material or dental stone) was transferred to a tube containing 1 ml of sterile physiological saline then the sample was vortex-mixed for 60 sec and serially diluted 10fold to 10–3, then 100 μl from each dilution was inoculated on blood agar plates, which were incubated aerobically for 48 hr at 37°c and the numbers of cfu/ml were calculated (3). microbiological samples were taken at three different stages to detect the presence of contaminating bacteria. these stages were: the impression before pouring, the impression after pouring, and the hardened stone model after separation from the impression results effect of (naf) on the setting time of alginate impression material show a decrease in setting time of alginate as the concentration of (naf) increased in all groups of alginate material with the lowest mean values of (91.1) sec at 4% naf appear in table (1) table 1: mean, sd, anova and lsd for setting time test (sec) for different disinfectant concentrations groups mean s d o n e w a y anova p value control (0%) 196.6 2 . 5 0 . 0 0 0 hs naf (0.25%) 196.7 1 . 5 * naf (0.5%) 191.8 0 . 7 * naf (1%) 184.7 2 . 6 * * naf (2%) 143.9 2 . 4 * * naf (3%) 133.2 1 . 8 * * naf (4%) 91.1 1 . 9 * * (*)= significant difference from control (**)= highly significant at p ≤ 0.01 effect of (naf) on the dimensional change of alginate impression material, there is a decrease in dimensional change as the concentration of (naf) increased, with lowest mean value (23.802) at 4% naf. also the results of anova test appeared a highly significant differences (p<0.05) among all tested groups of alginate mixed with different concentration of (naf) as shown in table (2). table 2: mean, sd, anova and lsd for dimensional change test (mm). groups mean s d o n e w a y anova p value control (0%) 24.109 0.003 0 . 0 0 0 hs naf (0.25%) 24.109 0 . 0 0 1 naf (0.5%) 24.107 0 . 0 0 1 naf (1%) 24.076 0.019* naf (2%) 24.063 0.007* naf (3%) 23.984 0.014** naf (4%) 23.802 0.019** (*)= significant difference from control (**)= highly significant at p ≤ 0.01 effect of (naf) on the detail reproduction of alginate and stone casts: there is a well-defined, sharp detail and continuous line at concentration of 0.25%, 0.5%, 1%, 2% naf and control group, with non-significant differences (p<0.05) among these tested rank groups. while the result of 3% naf has some loss of sharpness and the 4% naf concentration has poor detail and loss of continuity of line, these results were subjected to statistical analysis using kruskal-wallis test =49.537 j bagh college dentistry vol. 27(1), march 2015 effect of sodium restorative dentistry 74 effect of (naf) on the tear strength of alginate impression material: there is an increase in strength as the concentration of (naf) increased, with highest mean value (1.099) at 2% concentration of naf .while the results of 3% naf and 4% naf were (0.540) and (0.464) respectively. as shown in table (3) the results of anova test appeared a highly significant differences (p<0.05) among all tested groups of alginate mixed with different concentrations of (naf). table 3: means, sd, anova and lsd for tear strength (n/mm2). groups m e a n s d one-way anova p value control (0%) 0 . 8 3 7 0 . 0 3 3 0 . 0 0 0 hs naf (0.25%) 0 . 8 3 8 0.0103* naf (0.5%) 0 . 8 4 0.0105* naf (1%) 0 . 9 2 5 0.0302* naf (2%) 1 . 0 9 9 0.1064** naf (3%) 0 . 5 4 0.0278* naf (4%) 0 . 4 6 3 0.0333* (*)= significant difference from control (**)= highly significant at p ≤ 0.01 effect of (naf) as antimicrobial against streptococcus mutans and candida albicans: statistical analysis revealed that alginate mixed with naf have remarkable decrease in candida albicans and streptococcus mutans cell count test (cfu/ml). mean, sd , anova and lsd had been used for different groups of alginate impression materials in testing of the antimicrobial effect before and after pouring of the impressions and on the stone cast, table (4) show different groups of alginate impression materials in testing of the candida albicans before casting of the impressions. discussion the ada has recommended high disinfection standards for dental equipment, including dental impressions, to prevent cross infection between members of dental teams. (23). it has been reported that irreversible hydrocolloid impression carries two to five times more microorganisms than elastomers. (6). this can be disinfected by immersion or spraying in any compatible disinfectant. irreversible hydrocolloids are susceptible to dimensional distortion during disinfection procedure because of its hydrophilic nature (24). many impressions are sent to dental laboratories without proper disinfection, some of which are clearly contaminated with blood and food debris. studies have reported that 67% of all the dental impression, crown, denture, wax and other materials send to laboratory have harmful bacteria on them (25). table 4: means, sd, anova and lsd for candida albicans cell count test (cfu/ml) before casting of impression groups m e a n s d one-way anova p value control (0%) 571.7 2.413 0 . 0 0 0 hs naf (0.25%) 571.5 2.172 naf (0.5%) 571.5 2.670 naf (1%) 253.5 2.057* naf (2%) 79.38 0.326** naf (3%) 47.24 0.616** naf (4%) 27.53 0.941** (*)= significant difference from control (**)= highly significant at p ≤ 0.01 in the present study alginate impressions were disinfected with naf, and chosing recommended concentration that can produce self-disinfecting alginate impression material. by mixing alginate with (1%, 2%, 3%, 4%naf), setting time was decreased from (196.6) sec to (91.1) sec respectively, significant decrease in these values, these results was in agreement with results obtained from mixing of alginate with 2%naf (26) and disagree with the results of 1% naf alginate material as they use fluoride solution in 100ppm, this might be due to different methodology and addition procedure. the decrease setting time test this may be due to strong activity of fluoride ions and their affinity to calcium ions, sodium ions will be increased in the reaction speed and decreased setting time this could be explained, that sodium phosphate which control the setting characteristics of alginate materials (inhibitor of the reaction) sediments down wards while the other reactive components sediments upwards, so there will be sufficient calcium ions that required to complete the cross linking of alginate chains and thus accelerate the setting time of the material together with the exothermic reaction that produce more heat to accelerate the reaction and also observed that the extent to which the setting time increased was dependent on the type of irreversible hydrocolloid impression material. there is an increased in dimensional change as the concentration of (naf) increased, with lowest mean value (23.802) at 4% naf. a reduction in measurement represented alginate shrinkage. based on the obtained results, the null hypotheses were not accepted at 3% naf, 4% naf (the null hypothesis for these experiments was that the mean distances measured in the control group were the same, irrespective of the impression j bagh college dentistry vol. 27(1), march 2015 effect of sodium restorative dentistry 75 being mixed with naf.). the differences attained 0.3 mm (3 × 10-4 m), however, it was possible to observe statistically significant differences, although these changes were well below the ada specification stander of < 0.5%. these study results are consistent with those of taylor et al (24) who reported that an overall improvement of the dimensional change of alginate impression material after chlorhexidine disinfection compared with controls and meet ada recommendation. in contrast to those findings, kern et al (27) showed for the same alginate material a significant deterioration of disinfected impressions. the surface detail reproduction of alginate impression material and stone models were not significantly affected by the choice of concentrations with (0.25%, 0.5%, 1%, 2% naf) alginate impression material, this was in agreement with guiraldo et al (28). while 3% naf has some loss of sharpness and the 4% naf concentration has poor detail and loss of continuity of line this was in agreement with a previous study done by hiraguchi et al (29) which appeared that stone casts resulted from pouring decontaminated alginate impressions using the employed disinfectants showed slight dimensional shrinkage and the surface detail reproduction of stone modelsand dimensional change of other alginate products was changed. in the present study the observed differences in the behavior of the impression materials with different concentrations of naf which affect some changes in the dimensions of the resultant casts may be attributed partly to the different characteristics of the impression material composition themselves, and partly to the different chemical reaction containing alkaline ph caused bubbles and macroscopic alterations, like little craters in alginate molds. as there were non-significant differences in the surface detail reproduction and dimensional accuracy of stone models produced using low concentrations of the alginate impression materials with naf or disinfectant solutions, the alginate materials with its additives evaluated in this study are factors of choice regarding surface detail reproduction and dimensional accuracy of stone models. detail reproduction is mainly influenced by flow of the unset irreversible hydrocolloid into the details and its compatibility with the gypsum products. naf reduced the detail reproduction in irreversible hydrocolloids which could be attributed to the accelerated setting preventing it from flowing into the details; also naf may decrease the wettability of the impression and poor detail reproduction. further, it may also be related to the compatibility between gypsum product and set irreversible hydrocolloid impression material. it can be noticed that addition of naf fluoride to alginate in 1%, 2% naf resulted in minor increase in tear strength of alginate impression materials. this may be due naf has an effect to increase the consistency of the material and increase the elastic and decrease the plastic qualities of the alginate. also this was in agreement with mac et al (30) who attribute it as function of the rate at which the material is deformed, and the time at which the material is tested, and the consistency of the mix. candida albicans, and streptococcus mutans were selected to investigate the disinfection efficacy of naf disinfectant agents. the results revealed that the naf has a bacteriostatic effect on the streptococcus mutans, and this was in agreement with lobo et al (31). in conclusions; mixing of alginate impression material with a disinfectant may alter their properties depending on the type and concentration of the disinfectant. among these methods that are used in the present study, naf that can be considered as a suitable disinfectant liquid for mixing with alginate impression material as it did not significantly affect the properties of the material. naf at high concentration had altered the properties of alginate impression materials, and their effect on the properties was concentration dependent. hence, 2% naf was the optimum concentration with minimum effect on the other properties with the benefit of internal disinfection that 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jones jc, wood dj. the effect of disinfecting alginate and addition cured silicone rubber impression materials on the physical properties of impressions and resultant casts, eur j prosthodont restor dent 1998; 6(3): 103-10. 13. astm d624: standard test method for tear strength of conventional vulcanized rubber and elastomers, active standard astm d624, 2005. 14. tenovuo j, lagerlof f. saliva. in: thylstrup a, fejerskov o (eds). textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1994. p. 17-43. 15. nevzalolu eu, ozcan m, kauako, kadir t. adherence of candida albicans to denture and silicone based – resilient liner material with different surface finish line. oral invest 2007; 11: 231-6 . 16. edwardsson s. thylstrup a, fejerskov o. textbook of cariology. 3rd ed. copenhagen: munksgaard; 1986. p.74-106. 17. casemiro la, martins chg, panzeri fdc. bacterial, fungal and yeast contamination in six brands of irreversible hydrocolloid impression materials. braz oral res 2007; 21(2): 106-11. 18. koneman e, allen s, janda w, scherekerger p. color plates and textbook of diagnostics microbiology. 4th ed. philadelphia: jb. lippincott co.; 1992. 19. willim f, vincent d. an overview of the genus streptococci. j perio dent 2005; 12(3): 13-22. 20. collins md, lawson pa. the genus abiotrophia (kawamura et al.) is not monophiletic: proposal of granulicatella gen. nov., granulicatellaadiacenscomb.nov.,granulicatellaelegan s comb. nov.andgranulicatellabalaenopterae comb. nov. int j syst evol microbiol 2000; 50: 365-9. 21. miznerjames j. mosby's review for the pharmacy technician certification. 3rd ed. 2013. p. 274-310. 22. egusa h, soysa ns, ellepola an, yatani h, samaranayake lp. oral candidosis in hiv-infected patients. current hiv res 2008; 6: 485–99. 23. jagger dc, al jabra o, harrison a, vowles rw, mcnally l. the effect of a range of disinfectants on the dimensional accuracy of some impression materials. eur j prosth dent restor dent 2004; 12:154-60. 24. taylor rl, wright ps, maryan c. disinfection procedures: their effect on the dimensional accuracy and surface quality of irreversible hydrocolloid impression materials and gypsum casts. dent mater 2002; 18:103-10. 25. powell gl, runnells rd, saxon ba, whisenant bk. the presence and identification of organisms transmitted to dental laboratories. j prosth dent 1990; 64: 235-7. 26. jian w, wanb q, chaoc y, chena y. a selfdisinfecting irreversible hydrocolloid impression material mixed with chlorhexidine solution. angle orthod 2007; 77: 899 27. kern m, rathmer rm, strub jr. three-dimensional investigation of the accuracy of impression materials after disinfection. j prosth dent 1993; 70: 449–56. 28. guiraldo rd, borsato tt, berger sbs, lopes mb, gonini a jr, sinhoreti mac. surface detail reproduction and dimensional accuracy of stone models and influence of disinfectant solutions on alginate impression materials. braz dent j 2012; 23(4): 417-21. 29. hiraguchi h, nakagawa h, uchida h, tanabe n. effect of storage of alginate impressions following spray with disinfectant solutions on the dimensional accuracy and deformation of stone models. j dent mater 2004; 23: 8-15. 30. mac pgw, craig rg, peyton fa. mechanical properties of hydrocolloid and rubber impression materials. school of dentistry, ann arbor, michigan. j dent res 1987; 46: 77. 31. lobo pl, de carvalho cb, fonseca sg, de castro rs, monteiro aj, fonteles mc. sodium fluoride and chlorhexidine effect in the inhibition of mutans streptococci in children with dental caries: a randomized, double-blind clinical trial. oral microbial immunol 2008; 23(6): 486-91. الخالصھ لملوثة فقرات یصعب التعامل تلوث طبعات االسنان مع اللعاب والدم من تجویف الفم یحصل مباشرة في عیادات االسنان ومختبرات صناعة االسنان یجعل من طبعات االسنان ا: المقدمة لویث القوالب الجبسیة المصبوبة مقابل الطبعة ؛ على ایة حال غمس او رش طبعات االسنان اشارت التقاریر السابقة الى امكانیة الطبعات الملوثة بت. معھا من وجھة نظر انتشار االخماج .من مادة االلجنیت الشائعة االستعمال مع المعقمات لھا تأثیر سلبي على دقة القوالب او اجزائھا فحص تغییر االبعاد ,فحص وقت التصلب,قوة التمزق(سیھ طبقا لنوع الفحص المستعمل تم تقسیمھا الى خمس مجامیع رئی, عینھ 800في ھذه الدراسھ تم تحضیر :المواد واسالیب العمل . وفحص دقة االبعاد وعینات الفحص البكتیري التي تم تقسیمھا بین المكورات المسبحیھ میوتان والفطریات البیضاء .المستعملھ ) یدالصودیوم فلورا(كل مجموعھ رئیسیھ تم تقسیمھا الى ثمان تقسیمات فرعیھ طبقا لتراكیز .قد مزجت مع مادة طبعة االلجنیت وقد تم مقارنتھا مع االلجنیت العادي بدون اي معقم%) 40.25(استعملت ست تراكیز لفلورید الصودیوم من قوة التمزق لجمیع الطبعات المختبره ھي اعلى من المنتجات كانت .مادة الطبعھ ذاتیة التطھیر المحتویھ على فلورید الصودیوم قد اظھرت قتل معنوي للجراثیم بعد عمل الطبعات :النتائج اما بالنسبھ لوقت ,لمحتویھ علیھالیس ھناك فرق احصائى معنوي بین نتائج اختبارات تغیر االبعاد وكذلك اختبارات دقة الطبعھ المحتویھ على صودیوم فلوراید واالخرى غیر ا.القیاسیھ كان ي بین المواد القیاسیھ الغیر محتویھ على صودیوم فلوراید والمواد المختبره حیث ان المواد المختبره الغیر محتویھ على صودیوم فلورایدالتصلب للطبعات فقد كان ھناك فرق احصائ .ما ھو یحصل عادةان مواد الطبعات ذاتیة التطھیر تم تطھیرھا بشكل كلي خاللھا ولیس فقط على سطحھا ك.لھا وقت تصلب اطول من جمیع المواد المختبره االخرى غیر االبعاد وھو موصى بھ كخطوه ان استعمال فلورید الصودیوم عند اخذ طبعات االلجنیت لالسنان یعتبر اجراء جید في تقلیل التلوث وانتقال العدوى ولھ تاثیر قلیل على ت:االستنتاج .لحمایة طبیب االسنان وفریق مختبرات االسنان مسبحیھ میوتان والفطریات البیضاءالمكورات ال, صودیوم فلوراید, لجنیتمادة طبعة األ:الكلمات المفتاحیھ raghad final.doc j bagh college dentistry vol. 26(2), june 2014 dental caries among orthodontics, pedodontics and preventive dentistry 157 dental caries among a group of boys with β-thalassemia major (10-12 years old) in relation to salivary mutans streptococci raghad r. al-zaidi, b.d.s. (1) sulafa k. elsamarrai, b.d.s., m.sc., ph.d. (2) abstract background: beta thalassemia major is an inherited disorder that may affect general and oral health.the purpose of this study was toassess the severity of dental caries in relation to oral cleanliness, mutans streptococciamong a group of boys with beta thalassemia majorin comparison with a control group. materials and methods: the study involved 30 boys with btm aged 10-12 years compared to 30 healthy boys with the same age group. d1-4mfs and d1-4 mfs indices were applied (muhlemann, 1976), the viable counts of mutans streptococci in stimulated saliva were also determined. results: the entire thalassemic group was caries-active. for both dentitions, a higher dmfs/dmfs values were recorded for study compared to control group, difference was statistically not significantconcerning dmfs, while it was statistically significant concerning dmfs (p<0.05). salivary bacterial counts of mutans streptococci were found to be higher in the study compared to control group and the difference was statistically highly significant (p<0.01).all correlations between bacterial counts and dmfs/dmfs indices in study group were statistically not significant. conclusion: patients with beta thalasemic major had more caries severity compared to normal subjects. key words: β-thalassemia, mutans streptococci. (j bagh coll dentistry 2014; 26(2): 157-159). الخالصة . االضطرابات الوراثیة التي قد تؤدي الى انخفاض في انتاج كریات الدم الحمراء كما یعمل على زیادة تحطیمھا النوع الكبیر أحد أنواع یعتبرفقر دم البحر األبیض المتوسط :المقدمة .تصیب الفم واللعاب مما قد یزید من احتمالیة االصابة بتسّوس األسنان یعاني المصابون بھذا المرض من عدة تغیرات جرثومیة التي قد المكّورات المسبحیة عند مجموعة من األطفال الذكور المصابین بمرض فقر دم البحر األبیض المتوسط , نظافة الفم, تھدف ھذه الدراسة الى حساب حّدة تسّوس األسنان :أھداف الدراسة .جموعة ضابطةالنوع الكبیربالمقارنة مع م تم قیاس حّدة تسّوس األسنان . من األطفال األصّحاء ومن نفس الفئة العمریة 30سنة بالمقارنة مع ) 1210(مریض تتراوح أعمارھم مابین 30شملت الدراسة :المواد وطرق العمل ّینات الُلعاب المحّفز باالضافة احتساب االعداد الحّیة للمكّورات المسبحّیة في تم جمع ع). 1976(حسب طریقة موھلمان ) d1-4 mfsو d1-4 mfs) (حشوة, قلع, تسّوس(حسب مقیاس .اللعاب لدى ) dmfs) (حشوة, قلع, تسّوس(أظھرت النتائج وجود قیم عالیة للتسّوس حسب مقیاس , فیما یتعلق باألسنان اللبنیة. أظھرت النتائج اصابة جمیع االطفال بتسّوس األسنان :النتائج لدى المرضى ) dmfs) (حشوة, قلع, تسّوس(وجدت قیم عالیة للتسّوس حسب مقیاس , فیما یتعلق باألسنان الدائمیة. قارنة باألطفال األصّحاء مع عدم وجود فروقات معنویةالمرضى م ند األطفال المصابین بالمرض مقارنة مع المجموعة الضابطة مع النتائج بّینت أن أعداد المكّورات المسبحیة أعلى ع. )p<0.05(مقارنة باألطفال األصّحاء مع وجود فروقات معنویة .كل العالقات بین أعداد المكورات المسبحیة في اللعاب مع تسّوس األسنان لألطفال المصابین بالمرض كانت بدون فروقات معنویة.)p<0.01(وجود فرق معنوي عاٍل .مما یعني ضرورة توفیر برنامج وقائي فّعال لھؤالء األطفال المرضى, من أقرانھم من األطفال األصّحاء وجد أن تسّوس األسنان في األطفال المرضى أعلى :األستنتاج .المكّورات المسبحیة المیوتانز, فقر دم البحر المتوسط النوع الكبیر: كلمات مفتاحیة introduction beta thalassemias are a group of inherited blood disorders caused by reduced or absent synthesis of the beta chains of hemoglobin (1, 2). from the few studies regarding dental caries among patients with btm it was concluded that the prevalence and severity of this disease were higher in those patient than in normal subjects (3, 4). there are a limited number of studies concerning counts of mutans streptococci in relation to dental caries in btm (5). this study was designed to correlate dental caries severity to salivary mutans streptococci among of βthalassemia major patients. (1)master student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2)professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad materials and methods the study group included 30 boys, with an age range of 10-12 years according to the last birth day (6); they were already diagnosed with βthalassemia major, attending the thalassemic center in ibn al-baladi hospital for their regular checkup and blood transfusion. the control group included 30 boys matching in age and genders with the study group; they were examined in their primary school nearby the hospital. prior to clinical examination, collection of stimulated salivary samples from both study and control groups was done (7). each individual was asked to chew a piece of arabic gum for one minute then to remove all saliva by expectoration, chewing was then continued for ten minutes with the same piece of gum and saliva collected in a sterile screw-capped bottles. after collection and disappearance of salivary foams, 0.1 ml of saliva wastransferred to 0.9 ml of sterile phosphate buffer saline (ph 7.0) for microbiological analysis. dental caries was diagnosed by clinical examination; using dental mirror and sharp dental j bagh college dentistry vol. 26(2), june 2014 dental caries among orthodontics, pedodontics and preventive dentistry 158 explorer. assessment and recording of caries experience was by the application of (d1-4 mfs/d1-4 mfs). the selective media for the cultivation of mutans streptococci was mitis salivarius bacitracin agar. isolation and identification of bacteria were done according to holbrook and beighton(8). statistical analyses were achievedby using spss version 20 (statistical package for social sciences). descriptive measurement (mean and standard deviation) and interferential statistic involved (student's t-test, paired t-test, person's correlation coefficient, and multiple liner regression) were applied. the level of confidence was 95%. results clinical examination showed that all subjects were affected by dental caries. decayed, missed and filled teeth surfaces of boys by fractions of d14mfs/d1-4 mfs index are represented by their means and standard deviations (sd) in tables (1) and (2). salivary bacterial counts of mutans streptococci were found to be higher in study group (3.63±1.650)cfu/ml×104 compared to control group (1.93±0.907)cfu/ml×104 and the difference was statistically highly significant (p<0.01). all correlations between bacterial counts and dmfs/dmfs were statistically not significant table (3). tables (4) and (5) illustrate results of single linear regressions of dmfs and dmfs indices as a (dependent variable) in both study and control groups explained by mutans streptococci count (independent variables). the recorded correlation coefficient (r) between dmfs and bacterial count was 0.242 in study group and 0.320 in control group, the r2 value was lower in the study compared to the control group. for dmfs, the correlation coefficient (r) with bacterial count was 0.041 in study group and 0.252 in control group; the r2 value was also lower in the study compared to the control group. table 1: caries-experience of primary teeth (dmfs) among study and control groups parameters no. study control mean ±sd mean ±sd ds 30 6.100 5.797 4.400 4.966 ms 30 0.330 1.269 0.630 2.684 fs 30 dmfs 30 6.430 6.185 5.030 5.468 table 2: caries-experience of permanent teeth (dmfs) in study and control groups parameters no. study control t-value p-value mean ±sd mean ±sd ds 30 6.500 4.297 4.230 2.029 2.613* 0.011 ms 30 fs 30 dmfs 30 6.500 4.297 4.230 2.029 2.613* 0.011 *significant at the level p<0.05,df=29 table 3: correlation coefficients between mutans streptococci counts in saliva and cariesexperience (primary and permanent teeth) in study and control groups caries-experience study control r p r p dmfs 0.242 0.198 0.320 0.084 dmfs -0.041 0.831 0.252 0.179 table 4: single linear regression of caries-experience (dmfs) with mutans streptococci counts in study and control groups group coefficients t-value p-value b s.e study r2=5.8% 1.168 0.886 1.318 0.198 control r2=10.3% 1.930 1.079 1.789 0.084 j bagh college dentistry vol. 26(2), june 2014 dental caries among orthodontics, pedodontics and preventive dentistry 159 table 5: single linear regression of caries-experience (dmfs) with mutans streptococci counts in study and control groups group coefficients t-value p-value b s.e study r2=0.2% -0.137 0.634 -0.216 0.831 control r2=6.4% 0.564 0.409 1.380 0.179 discussion data of the present study showed that all children in both study and control groups had dental caries, i.e. a 100% of occurrence of the disease; this may indicate that both groups may have the same susceptibility to dental caries. however, data revealed that there is a variation in the severity of caries-experience between the groups; this was true for primary and permanent teeth. for both dentitions, caries-experience as measured by dmfs/dmfs index was higher in the study group compared to the control and differences were statistically significant for dmfs and not significant for dmfs. this may indicate a higher severity of dental caries among study group compared to control; the same results were recorded by others (9, 10). in thalassemic patient, the dmfs index was composed of decay surface only, as no case was seen with either missing or filling surfaces. this is an indication of the increased need for dental treatment. the increased severity of dental caries among thalassemic children may be attributed to poor oral cleanliness, related to certain oral structural changes that take place in thalassemic patient due to maxillary enlargement result in protrusion of anterior teeth, increase space between teeth, over-bite or open-bite and varying degrees of malocclusion, aid in more plaque accumulation (11). another explanation for the increase severity of dental caries in the study group is the higher counts of mutans streptococci in the thalassemic group; as found by this study with a statistically high significant difference, the same result was reported by other (5).the higher counts of salivary mutans streptococci may be related to the lower iga level in saliva of thalassemic patients that may lead to increased microbial proliferation (12). results of multiple linear regressions revealed a more impact of mutans streptococci on dental caries of the control group compared to study group. studying bacterial count in dental plaque may give more obvious picture regarding the correlation between count of this cariogenic bacteria and dental caries. the increased cariesseverity among thalassemic patients may indicate the increase need for special care and preventive programs for this special group. references 1. tefferi a.primary hematology, 10th ed.usa, 2001. 2. greer j, rodgers g, foerster j, glader b, arber d, means r. wintrobe's clinical hematology.12thed. chain, 2009. 3. al-raheem y, abdul hussein m, al-ani r, alrubayee m. the impact of thalassemia major on dental integrity and development. mdj 2009; 6: 4. 4. katariasushla a, arora m, dadhich a, katariakushal r. orodental complication and orofacial manifestation in children and adolescents with thalassemia major of western rajasthan population: a comparative study. int j biol med res 2012; 3(2):1816-9. 5. lugliè pf, campus g, deiola c, mela mg, gallisai d. oral condition, chemistry of saliva chemistry of saliva and salivary levels of streptococcus mutans in thalassemic patients. clin oral inves 2002; 6(4): 2236. 6. who: oral health surveys. basic methods. 4th ed. geneva. 1997. 7. tenovou j, lagerlöf f. saliva. in: thylstrup and fejerscov o. textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1996. p. 17-43. 8. holbrook w, beighton d. streptococcus mutans levels in saliva and distribution of serotypes among 9-yearold icelandic children. scan j dent res 1986; 95:3742. 9. mohammed i. oral health status , treatment needs and dentofacial anomalies among (5-14) years patients with β– thalassemia major syndrome in comparison to school children in baghdad province. a master thesis, college of dentistry, university of baghdad, 2004. 10. noori m. orofacial, salivary and radiographic changes in major thalassemic patients in mousl. a master thesis, college of dentistry, university of baghdad, 2004. 11. al-wahadni am, tami dq, alomari mo. dental disease in subjects with beta-thalassaemia major. comm dent oral epidem 2002; 30(6): 418-22. 12. siamopoulou ma, mavridou a, galanakis e, vasako s, fatourou h, lapatsanis p. flow rate and chemistry of parotid saliva related to dental caries and gingivitis in patients with thalassemia major. int j pediatr dent 1992; 2(2): 93-7. j bagh college dentistry vol. 28(4), december 2016 in vitro comparative restorative dentistry 49 in vitro comparative assessment of composite nanoleakage using various dentine surface treatments mohammed h. abbood, b.d.s. (a) raghad a. al-hashimi, b.d.s., m.sc., ph.d. (b) abstract background: the treatment of dental tissues proceeding to adhesive procedures is a crucial step in the bonding protocol and decides the clinical success ofrestorations. this study was conducted in vitro, with the aim of evaluating thenanoleakage on the interface between the adhesive system and the dentine treated by five surface modalities using scanning electron microscopy and energydispersivex-ray spectrometry. materials and methods: twenty five extracted premolars teeth were selected in the study. standardized class v cavities were prepared on the buccal and lingual surfaces then the teeth divided into five main groups of (5 teeth in each group n=10) according to the type of dentine surface treatment that was used: group (a): dentine was conditioning with er, cr: ysgg laser. group (b): dentine was conditioning with (er, cr: ysgg laser + acid). group (c): dentine was conditioning with (acid + er, cr: ysgg laser). group (d): dentine was conditioning with acid etch. group (e): dentine was conditioning with acid + 10% sodium hypochlorite. for all the teeth sbmp adhesive were used and restored with z250 composite restoration then all specimens were subjected to thermocycling 500 cycles, at 5° to 55 °c. the teeth were soaked in silver nitrate suspension. then the teeth sectioned bucco-lingually across the centre of the restorations. the specimens were characterized using scanning electron microscopy and the amount of nanoleakage was measured by edx spectro-analysis to identify the existence of metallic silver particles. results: data were analysed statistically by one way anova test and (lsd) tests. the results showed that there were statistically highly significant differences among all groups of the present study.the resultshowed that the acid and laser (group iii) exhibited the lowest mean value of nanoleakage at around (6.14 %), whereas the highest mean value of nanoleakage (12.83 %) was determined by the only acid (group iv). conclusions: treating the acid etched dentine with er: cr: ysgg laser showed promising results as it exhibits lowest amount of nanoleakage of the adhesive bonding system. keywords: er, cr: ysgg laser, silver nitrate, nanoleakage, sem/edx. (j bagh coll dentistry 2016; 28(4):49-55) introduction the seal of a restorative material against the tooth structure, and the quality and durability of the seal, are major considerations for the longevity of restorations. since the introduction of the acid-etching technique for the pre-treatment ofdental hard tissues (1), new techniques and adhesive materials thatcan fulfil their function of bonding to enamel and dentine have been developed andmodified (2). yet, a disadvantage distinguished to acid etchingis the demineralization of tooth tissues, which create them more permeable and liableto acid attacks, particularly if the demineralized substrates are not entirely filled byadhesive resins (3). the clinical significance beyond studying thenanoleakage measurement using different surface treatments is to improve the qualityof bonding of composite restoration. thus, improving the durability of restoration canbe achieved. despite the significant improvement in bondingcapacity, up-to-date, no method and/or restorative material being capable ofeliminating nanoleakage. for this reason, new methods have been developed toimprove the quality and longevity of restorations (4). (a) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (b) assist. professor, department of conservative dentistry, college of dentistry, university of baghdad. in order to overcome this limitation, recent investigations suchas dental lasershave been introduced to be used as alternative tools that could better prepare theenamel and dentine surfaces for future bonding procedures. high power lasers havebeen produced in dentistry to carry out cavity preparations and to promote chemical/morphological changes on the tooth surface. erbium lasers (er:yag ander,cr:ysgg) have been considered the most promising lasers to be used onmineralized tissues because both wavelengths show high absorption by water andhydroxyapatite (5). previous studies have evaluated the effect of erbium lasers in surfacemorphology of dentine, wherein they have found an irregular appearance, withoutsmear layer, with open dentinal tubules and prominent peritubular dentine, with a microretentive morphological pattern possibly favourable to bonding procedures (6). nanoleakage is originally defined as the phenomenon of tracer penetration via 20to100nm spaces into hybrid layers, even in the absence of a marginal gap (1). nanoleakage is considered an important indicator of the sealing ability ofrestorative materials and hybrid-layer quality, which subsequently affect thedurability of the restoration (1,7). the present study aimed at evaluating the nanoleakage on the interface between adhesive j bagh college dentistry vol. 28(4), december 2016 in vitro comparative restorative dentistry 50 system and the dentine with five different dentine surfacetreatmentsby scanning electron microscopy and energy-dispersive x-ray spectrometry. materials and methods teeth selection non-carious, non-restored twenty five sound maxillary first premolar teeth extracted for orthodontic purposes were conducted in the present study. teeth were cleaned from adhering soft tissues and calculus deposits with a hand scaler. the teeth were cleaned and polished using water and pumice with a prophylaxis rubber cup, and rinsed with water. all teeth were visually examined under a magnifying lens and by transillumination fibre optic from a light curing unit for the presence of cracks and the ones that showed any defects were excluded from the study( 8). teeth mounting the teeth were mounted individually in a specifically designed locallymanufactured rubber mold with cold cure acrylic (major, italy) with the long axis of the tooth parallel to centre of the mold. each tooth was suspended in the middle of the mold using a ney surveyor (bego, germany) to ensure vertical positioning of the tooth inside the mold, as follows; the centre of the occlusal surface of each tooth was attached to the vertically moving arm of the surveyor along its long axis with sticky wax. when the axis of the tooth was positioned correctly, acrylic resin was poured into the mold and before it reached the dough stage the tooth was inserted. all specimens were embedded up to 3mm apical to the cej. after initial polymerization, the samples were placed in water to avoid overheating due to resin polymerization (4). cavity preparation on the buccal and lingual surfaces standardized class v cavities were prepared (2mm height, 2mm width, 2mm depth). a high speed hand piece was fitted to the surveyor (horizontal arm) in a manner that the long axis of the bur being vertical to the tooth, by a medium grain diamond bur no. 848, underneath water coolant. on the tooth surface the outline of the cavity was drawn by a 0.5 mechanical pencil by a matrix band with a previously made cut hole of 2 x 2 mm which was secure on the tooth using a retainer in which the gingival floor of the cavity was set at (1 mm) below the cemento-enamel junction of the tooth. the cavity form was finished by round bur in a low speed hand piece by water coolant. the teeth were arbitrarily divided into five groups each one consists of five teeth (n=10). samples grouping the teeth were randomly divided into five main groups (5 teeth in each group n=10) according to the type of dentine conditioning: group one: the class v conditioning only with laser. group 2: the class v conditioning with laser and acid etching, group 3: the class v conditioning with acid etching and laser, group 4: the class v conditioning with only acid etching, group 5: the class v conditioning with acid etching and 10% naocl. laser irradiation the er, cr:ysgg laser used in this study was waterlasei-plus (biolase technology inc., san clemente, ca, usa), which emits at a 2.78-μm wavelength. it has fixed pulse duration for hard tissues of 140 μs. the irradiation was accomplished in both vertical and horizontal directions, using 30 % of water spray and 60 % of air spray. laser tip was positioned upright to the target area of the dentine surface, with working distance of 1 mm (9) was kept from the dentine surface throughout the procedures. to ensure this distance between dentine and radiation tip, an endodontic file was fixed at the handpiece (10). scanning the surface in both orders (vertical and horizontal). each fibre tip was discarded after five times of use (11). laser hand-piece moved in a sweeping fashion by surveyor to obtain a homogeneous surface appearance over the entire area (12). the laser etching was performed for 15 s for each surface (13). using laser tip mz8 in the gold md handpiece (manufacture instruction). conditioning of dentine with acid the teeth were etched by the total etch technique (a 35% phosphoric acid etchant (3m) which was spread over the enamel and dentine start with the enamel borders of the restoration for 15 seconds. the cavities were carefully rinsed from phosphoric acid gel by water for 15 sec. the dentine surface was dry by an air syringe for two seconds using triple syringe at a distant of 1.5 cm to achieve a little moist surface (the surface is considerably glossy); however, no noticeable excess water should persist on the tooth surface. application of scotchbond multipurpose bond the scotchbond multipurpose bond was used onto the conditioned tooth structure by a bonding j bagh college dentistry vol. 28(4), december 2016 in vitro comparative restorative dentistry 51 applicator. in a gentle movement apply the primer with disposable brush tip then gently dried with air stream for 5 seconds. apply the adhesive bond and light cure for 10 seconds (manufacture instructions). placing the restoration the resin based composite was spread over in one incremental layer. before curing a transparent matrix was positioned to contour the restoration and cure for 20 second. the borders of the restoration were finished and polished by using sof-lex (3m) discs. application of sodium hypochlorite a sodium hypochlorite 10%solution was gently spread over for 1 min, rinsed by using runningwater for 20 seconds (14). the dentine surface was dry by an air syringe for two seconds using triple syringe at a distant of 1.5 cm. thermocycling procedure in an attempt to simulate the temperature changes that take place in the oral cavity, all specimens were subjected to thermocycling according to the international organization for standardization (iso) tr11405 standard of 500 cycles, at 5° to 55 °c, with a 15 second dwell time (15). ability to resist nanoleakage all the teeth were characterized using a stereo microscope to confirm that no flash was left along borders of the restoration. and then the entire tooth, excluding for the bonded interface and also the 1 mm of the tooth surface adjacent to the interface coated by two layers of nail varnish. the teeth were put in a 50% (weight/volume) silver nitrate liquid in total darkness for 24 hours, rinsed in running water for 5 minutes, immersed in photo-developing liquid, and subjected to a fluorescent light for 8 hours (which reduce the silver ions to metallic silver). then remove the teeth from the developing solution, the teeth were put in running water for 5 minutes and sectioned bucco-lingually through the centre of the restorations by a low speed diamond disk (1, 16). the cut surfaces were fixed in epoxy resin and polished by using increasingly fine diamond pastes (6, 3, 1 μm; buehler ltd, lake bluf, il, usa). then the specimens were placed in ultrasonic cleaner contain distilled water for 5 minutes, and they were dehydrated in increasing concentrations of ethanol (50%, 60%, 70%, 80%, and 90%) for 2 h each and in 100% ethanol for 24 h. final chemical using hexamamethyldisilazane (17), stable on aluminium stubs. the nanoleakage patterns were detected by scanning electron microscopy/ energy dispersive x-ray spectroscopy (sem-edx) (elemental chemical analysis by means of energy-dispersive x-ray spectroscopy (edx) using the backscattered electron image mode. the use of sem in combination with edx had the ability to present both distinct images and sensitive quantification of silver ion penetration accurate. as it permits analysis for the element composition of the scanned square area. thus, provides accurate identification for the presence or absence of metallic silver particles along the adhesive tooth / restoration interface. by this, both false negative and false positive results were excluded.for each specimen makes 3 readings by eds in the center of the gingival surface and 0.3 in the left and the right to the center to determine nanoleakage value by silver ions uptake (18). results the descriptive statistics of nanoleakage qualification detected by silver ion percentage for each group are shown in table 1. table 1: means and standard deviations of the experimental groups tested in this study, n=10 groups mean ±sd min. max. only laser 12.01 3.29 3.39 16.23 laser + acid 8.66 2.66 3.02 13.74 acid + laser 6.14 2.55 0.84 9.99 only acid 12.83 4.96 4.02 18.22 naocl 7.65 2.87 1.06 13.91 one-way anova test revealed that there were statisticallyhighly significant differences among all the groups tested in the present study (p ≤ 0.01) as reported in table 2. table 2: anova test for the nanoleakage of the experimental groups tested in this study, n=10 anova test sum of squares df mean square ftest pvalue between groups 365.899 4 91.475 8.26 0.000 hs within groups 498.349 45 11.074 total 864.248 49 further comparisons among groups were done using the least significant difference test (lsd test) to see where the significant difference occurred. the results showed that there was no significant difference (p > 0.01) when comparing j bagh college dentistry vol. 28(4), december 2016 in vitro comparative restorative dentistry 52 figure 1: representative backscattered sem images of the resin–dentine interfaces of group (i) only laser surface conditioning. (c composite, h hybrid layer, d dentine, red arrow refer to nanoleakage). group (i) and groups (ii and iv), whereas a statistically significant difference (p < 0.01) was observed when comparing group (i) and groups (iii and v). discussion the clinical relevance of the current study was to improve the marginal adaptation of composite restoration by conditioning the dentine surface with a variety of treatments. among the most promising systems of laser is the family of erbium lasers because their wavelength coincides with the main absorption peak of water and hydroxyapatite (19). thus er: yag and er, cr: ysgg lasers interact well with all biological tissues, including enamel and dentine surface (9). it has been reported that there is often a discrepancy between the depth of acid-etching and the degree of resin infiltration and exposed collagen network (20). this region may be another site for silver uptake. although the amount of nanoleakage may be very small (nanometre-size) in the bonded assembly, it has the potential to serve as a pathway for water movement within the adhesive–dentine interface over time (21). evaluation of silver uptake (i.e. nanoleakage evaluation) provides good spatial resolution of submicron defects in resin infiltration or inadequate polymerization (22). the findings of the present study are discussed in details and justified as shown in the following sections below: group one (only laser conditioning figure 1) there are non-significant differences with (only acid conditioning group) and (laser + acid conditioning group) while there are a highly significant differences between this group and (acid + laser conditioning group) and (10% naocl conditioning group)this result could be attributed to the effect of laser on the dentine surface that will effect on the monomer diffusion, the characteristics of erbium-irradiated dentine, such as the absence of smear layer, opened dentinal tubules and the presence of an irregular surface after irradiation, could be favourable for adhesive procedures (23). hossain et al (24) showed that in addition to the lack of smear layer and presence of intact enamel rods as well as exposed dentinal tubular openings in their sem observations, laser prepared surfaces provided better bond abilities with restorative materials and acid etching could be easily replaced by laser use. similarly, türkmen et al (25) found that the er,cr:ysgg laser “etches” the enamel surface more effectively than 37% phosphoric acid for subsequent attachment of composite material. the type iii acid etching pattern with a regular rough surface and spaces could be seen with acid etching (26). dissolution of hydroxyapatite by acid produced tags and rough surfaces that afforded the mechanical lock for resin. the preferred type iii pattern was seen by the er:yag laser at a distance 1 and 2 mm and with the er,cr:ysgg laser at 1 mm. a uniform honeycomb appearance was evident. enamel irradiated with the er:yag laser at 4 ad 6 mm and with the er,cr:ysgg laser at a distance 2, 4 and 6 mm had the type iv etching pattern as described by silverstone et al (26). the surface characteristics and shear bond strength are suitable for enamel etching. the dentine surface after er,cr:ysgg laser irradiation shows no smear layer, dentine tubules are open and the subsurface is not demineralized. irradiation of dentine with an er,cr:ysgg laser creates a rough surface with chimney-like formations due to the preferential removal of intertubular dentine. group two (laser + acid conditioning figure 2) there are non-significant differences between this group and (only laser conditioning group), (acid + laser conditioning group) and (10%naocl conditioning group), while there are a significant differences between this group and (only acid conditioning group). this is possibly related to the creation a more homogeneous dentine surface by the acid etched that follow the laser etched widened dentine tubule orifices were seen when acid was applied after er,cr:ysgg laser irradiation, because of removing the mineral content of the dentine. flat surfaces were seen after acid etching (27). j bagh college dentistry vol. 28(4), december 2016 in vitro comparative restorative dentistry 53 figure 2: representative backscattered sem images of the resin–dentine interfaces of group (ii) laser + acid surface conditioning. (c composite, h hybrid layer, d dentine, red arrow refer to nanoleakage). figure 3: representative backscattered sem images of the resin–dentine interfaces of group (iii) acid +laser surface conditioning. (c composite, h hybrid layer, d dentine, red arrow refer to nanoleakage). acid etching following er,cr:ysgg laser irradiation could demineralize the inorganic portion of surface dentine and reproduce a suitable environment for molecular entanglement of polymer chains with collagen fibrils. furthermore, the widened dentinal tubule orifices also facilitated the deep infiltration of bonding agent. the extensive branching of the resin tags into lateral branches of dentinal tubules could be found acid etching of lased dentine could reinforce the hybrid layer; and formation of resin tags. acid etching following er,cr:ysgg laser conditioning can help reduce microleakage in class v restorations (13). group three (acid + laser conditioning. figure 3) there are non-significant differences between this group and (10% naocl conditioning group) and (laser + acid conditioning group), while there are a highly significant differences between this group and (only acid conditioning group) and (only laser conditioning group). this is due to the ability of er,cr:ysgg laser to remove the collagen network away from acid etched dentine and this will lead to enhance the infiltration potential of the monomer to the intact dentine and minimizing the nanoleakage. also removing of the collagen network away from acid etched dentine substrate will make the chemical composition of dentine more similar to that of enamel by decreasing the organic component of dentine substrate and this will cause a changing in the hydrophilic properties of the dentine. the depletion of collagen network from the surface of acid etched dentine results in: the permeability of dentine substrate will be enhancing due to the enlargement of dentinal tubules nearby the outer dentine surface; this will increase the distribution and spreading of adhesive monomers through dentine (28). the surface energy of dentine will be improved, because the high surface energy of the hydroxyapatite while the collagen has a low surface energy and this would produce improving in the diffusion of adhesive monomers through dentine. this description complies with that of bedran et al (29). the dentine is very rough and porous with many lateral branches of tubules are noticeable in main tubules which may contribute to enhance the diffusion of adhesive monomers through dentine, this complies with ferrari et al (30) wherein they justified the findings with the same explanation. er,cr:ysgg radiation is highly absorbed not only by the hydroxyapatite of dentine but also by the protein and lipid in collagen fibre (31). group four (only acid conditioning. figure 4) there are non-significant differences between this group and (only laser conditioning group), and there are a significant differences between this group and (laser + acid conditioning group), and highly significant differences between this group and (acid + laser conditioning group) and (10%naocl conditioning group). these differences were possibly due to the possibility of the adhesive system monomers not being able to penetrate completely the demineralized dentine after the acid etching, leaving a porosity zone that could lead to leakage. this porosity may permit the hydrolysis of collagen fibres which is believed to degrade the adhesive resin. j bagh college dentistry vol. 28(4), december 2016 in vitro comparative restorative dentistry 54 figure 4: representative backscattered sem images of the resin–dentine interfaces of group (iv) only acid surface conditioning. (c composite, h hybrid layer, d dentine, red arrow refer to nanoleakage). figure 5: representative backscattered sem images of the resin–dentine interfaces of group (v) 10% naocl surface conditioning. (c composite, h hybrid layer, d dentine, red arrow refer to nanoleakage). strong acids such as phosphoric acid create demineralization deeper than the diffusion capacity of the resin monomers thus leaving collagen fibres in the deep tissue layers unprotected (32). the deposition of silver ions occurred in most of the specimens along the base on the hybrid layer, and, according to the author, the difficulty of the penetration of the resin monomers all over the demineralized dentine extension is, in part, due to the limited size, length and sinuosity of the canals created around the collagen fibres that collagen fibrils within the hybrid layer are not fully embedded by dentine adhesives revealing different degrees of infiltration from the top to the bottom of the hybrid layer (33). for total-etch systems, these areas of sparse, imperfect resin infiltration exist because it is physically difficult for the adhesive monomers to penetrate the highly hydrophilic matrix of demineralized collagen fibrils, as previously indicated by other studies (34). group five (10% naocl conditioning. figure 5) there are non-significant differences between this group and (acid + laser conditioning group) and (laser + acid conditioning group), while there are a highly significant differences between this group and (only acid conditioning group) and (only laser conditioning group). this differences in the nanoleakage could related to the deprotinization procedure, this procedure first removes the exposed collagen and then dissolves the fibrils into the underlying mineralized matrix to create submicron porosities within the mineral phase. channels created are available for resin infiltration within the mineralized matrix. they show a complete difference in the morphology of deproteinized dentine as compared with the acid etched dentine. the diameter of tubule orifices increased after the naocl treatment of acid etched and demineralized dentine due to loss of demineralized peritubular dentine. this substrate has more hydroxyapatite crystals and may result in a more durable interface over time as it is basically made of minerals (14). our results are in accordance with the study done by goes and montes (35), wherein they concluded that collagen depletion prior to bonding application may prevent nanoleakage occurrence in dentinal walls. the following conclusions are drawn in this study: 1. none of the surface conditioning techniques used in the present study can prevent nanoleakage in class v cavity. 2. treating the acid etched dentine with er: cr: ysgg laser has led to a significant decrease the nanoleakage value at the adhesive bonding system. 3. using acid etch is important with the laser to reduce nanoleakage. references 1. buonocore m. a simple method of increasing the adhesion of acrylic filling materials to enamel surfaces. j dent res 1955; 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1: 455–65. 32. nakabayashi n, nakamura m, yasuda n. hybridlayer as a dentine bonding mechanism. j esthet dent 1991; 3(4):133–8. 33. duarte l. nanoleakage evaluation within the hybrid layer in class v cavities restored with different adhesive systems. study by scanning electron microscopy. araraquara: thesis (master of restorative dentistry) -faculdade of dentistry, paulista state university 1997; 25-9. 34. wang y, spencer p. hybridization efficiency of the adhesive/ dentin interface with wet bonding. j dent res 2003; 82: 141-5. 35. goes m, montes m. evaluation of silver methenamine method for nanoleakage. j dent 2004; 32: 391-8. shaimaa final.doc j bagh college dentistry vol. 26(3), september 2014 the validity of salivary oral diagnosis 66 the validity of salivary micrornas (hsa-mir-200a, hsamir-125a and hsamir-93) as oral squamous cell carcinoma biomarker shaimaa h. mudhir, b.d.s., m.sc. (1) raja h. al-jubouri, b.d.s., m.sc., ph.d. (2) ban a. abdul majeed, m.b.ch.b., m.sc., ph.d. (3) abstract background: oral squamous cell carcinoma represents the vast majority of oral cancer it is a common malignant tumor with an increasing incidence. around the world, the 5 year mortality rate of oral cancer is about 50%. thus novel biomarkers for early detection oral squamous cell carcinoma are needed. the level of three salivary micrornas namely hsa-mir-200a, hsa-mir-125a and hsamir-93 were measured in saliva of patients with oral squamous cell carcinoma and compared their levels in saliva of healthy control subjects to determine their potential as oral cancer biomarker. materials and methods: the level of these three micrornas was measured by using revers transcription, preamplification and quantitative pcr. results: only mir-200a present in a significantly lower level (p<0.05) in the saliva of oral squamous cell carcinoma patients than in control. mir-200a was the strongest parameter (most affected by disease status) in the context of differentiation between ossc and healthy controls (having the highest roc area of 0.781 which is significantly higher than the area associated with equivocal test). coming next in order of importance in the context of case-control differentiation was normalized ct values for hsa-mir-93, which has a reasonably high roc (0.650), but failed to show statically significance differences, p>0.05. conclusions: the detection of mirnas in saliva can be used as noninvasive and rapid diagnostic tool for the diagnosis of oral cancer. key words: saliva, mirna-200a, mirna-125a, mirna-93, oscc biomarkers, real time pcr. (j bagh coll dentistry 2014; 26(3):66-71). الخالصة س نوات 5إن معدل الوفی ات ذافي جمیع أنحاء العالم ، في معدالت االصابة مثل الغالبیة العظمى من سرطان الفم ھو ورم خبیث مع حدوث زیادةللفم ی سرطان الخالیا الحرشفیة :الخلفیة اللعابی ة micrornasت م قی اس مس توى ثالث ة لق د .للف م س رطان الخالی ا الحرش فیة عن روبالتالي ھناك حاجة إلى مؤشرات حیویة جدیدة للكشف المبك. ٪50من سرطان الفم ھو حوالي كفائتھ ا لتحدی د مجموع ة اص حاء و مقارنة مستویاتھا في اللع اب م ن للفم في اللعاب من المرضى الذین یعانون من سرطان الخالیا الحرشفیة mir-200a, mir-125a, mir-93وھي القی اس و )preamplification( تض خیم ،revers transcription)(العكسي باستخدام النسخ micrornasتم قیاس مستوى ھذه : المواد و الطرق . الفمسرطان ل بیولوجیة كعالمات .(real-time pcr)لكمي ا األكث ر ( االق وى المعلم ة mir-200a وك ان . ة االص حاء مقارن ة م ع مجموع لف م الحرش فیة ل ف ي لع اب المرض ى س رطان الخالی ا ) p>0.05(بكثی ر اق ل mir-200aمستوى :النتائج المقبل ة القادم ة ف ي ) . وھ و أعل ى بكثی ر م ن المنطق ة المرتبط ة 0.781م ن rocوج ود أعل ى منطق ة ( مجموع ة االص حاء و osscفي سیاق التمایز ب ین ) تضررا من حالة المرض < p، لكنھ فشل في اظھار ثابت ف روق ذات دالل ة ، ) 0.650(مرتفعة بشكل معقول roc، والتي لدیھا mir-93ھو ایز التمفي الترتیب من حیث األھمیة في سیاق الحاالت والشواھد 0.05 . .لتشخیص سرطان الفم ةوسریع واسعة في اللعاب كأداة تشخیصیة mirnas یمكن استخدام ال :االستنتاجات introduction oral cancer, predominantly oral squamous cell carcinoma (oscc), involving any part of the oral cavity affects over 300 000 people worldwide annually.(1) saliva is considered as a mirror of body health and is composed of variety of analyses from systemic sources that reach the oral cavity through various pathways. the role of saliva as a diagnostic tool has advanced exponentially over the past decade. the ability to measure a wide range of molecular components in saliva and compare them with serum coupled with the easy and non-invasive method of collection has made it feasible to study microbes, chemical and immunological markers. (1)ph.d. student. department of oral diagnosis, college of dentistry/ baghdad university. (2)professor. department of oral diagnosis, college of dentistry/ baghdad university. (3) professor, department of pathology and forensic medicine, college of medicine/ al-nahrain university. microrna (mirna) are small, highly conserved, single stranded of about 22 nucleotides in length, non-coding rna molecules involved in the regulation of gene expression. it is predicted that mirna account for 1-5% of the human genome and regulate at least 30% of protein-coding genes (2). micrornas are transcribed by rna polymerases ii and iii, generating precursors that undergo a series of cleavage events to form mature microrna. the conventional biogenesis pathway consists of two cleavage events, one nuclear and one cytoplasmic. however, alternative biogenesis pathways exist that differ in the number of cleavage events and enzymes responsible. how microrna precursors are sorted to the different pathways is unclear but appears to be determined by the site of origin of the microrna, its sequence and thermodynamic stability. j bagh college dentistry vol. 26(3), september 2014 the validity of salivary oral diagnosis 67 the regulatory functions of micrornas are accomplished through the rna-induced silencing complex (risc). microrna assembles into risc, activating the complex to target messenger rna (mrna) specified by the microrna. the degree and nature of the complementarity between the microrna and target determine the gene silencing mechanism, slicer-dependent mrna degradation or slicer-independent translation inhibition (3). three important observations early in the history of mirnas suggested a potential role in human cancer. firstly, the earliest mirnas discovered in the roundworm c. elegans and the fruit fly drosophila were shown to control cell proliferation and apoptosis(4). their deregulation may therefore contribute to proliferative diseases such as cancer. secondly, when human mirnas were discovered, it was noticed that many mirna genes were located at fragile sites in the genome or regions that are commonly amplified or deleted in human cancer (5). thirdly, malignant tumors and tumor cell lines were found to have widespread deregulated mirna expression compared to normal tissues (6). dysregulation of mirna expression profiles has been demonstrated in most tumors examined (7,8). however, the specific classification of mirna as oncogenes or tumor suppressors can be difficult because of the intricate expression patterns of mirnas. materials and methods twenty seven patients with oral squamous cell carcinoma were recruited at the maxillofacial surgery clinic of ghazi alhariri hospital, alkadhimia, al-ramadi and al-yarmouk teaching hospital, also 27 healthy control subjects with age and sex matched to the study group were participate in this study. unstimulated whole saliva samples (for all patients and controls) were collected between 8 a.m and 11a.m. subjects were asked to refrain from eating, drinking, smoking or oral hygiene procedures at least 1 hour before collection(9). consents from controls and patients were taken. saliva samples were centrifuged at 2600rpm for 15 minutes at 4 c. the supernatant was removed from the pellet and treated with superase (rnase inhibitor). for each 400µl of saliva supernatant 20µl of superase were added. the saliva samples were then kept at -80º c until the time of rna extraction (1) . 1. saliva rna extraction steps were conducted following the instruction leaflet of mirvana mirna extraction and according to the manufacturer (ambion, usa). two hundred microliters of the supernatant saliva were used for rna extraction by using the mirvana mirna isolation kit according to the instructions of the manufacturer. 2. reverse transcription: steps of the procedure were conducted according to the kit leaflet and according to the manufacture instructions of taqman® microrna rt kit (applied biosystems, usa). 3. preamplification reaction steps of the procedure were conducted according to the kit leaflet and according to the manufacture instructions taqman® preamp master mix protocol (applied biosystems, usa). 4. real-time pcr reaction steps of the procedure were conducted according to the kit leaflet and according to the manufacture instructions (applied biosystem, usa). statistical analysis of data 1. statistical packages for social sciencesversion 20 (spss-20) was applied to analyze demographic criteria of study and control groups. data were arranged as frequencies and the chisquare extracted p value was taken as significant when < 0.05. 2. real-time pcr data analysis after the end of experiment the qrtpcr machine displayed the data as ct (cycle threshold) value for each sample, ct value corresponds to the number of amplification cycles required for the fluorescent signal to exceed the background level. this means that ct levels are inversely proportional to the amount of products in the sample, i.e. a low ct value means a high expression of the mirna and vice versa. moreover, in this study mirnas with a ct value above 40 cycles are considered non-expressed (11). a. the data included: • ct values for hsa-mir-200a for oscc and healthy controls group. • ct values for hsa-mir-125a for oscc and healthy controls groups. • ct values for hsa-mir-93 for oscc and healthy controls groups. b. normalization of data: for each array the mean expression value was calculated, without prior removal of ct values ≥ 35, and thereafter divided with each individual mirnas ct value (11). j bagh college dentistry vol. 26(3), september 2014 the validity of salivary oral diagnosis 68 results and discussion salivary hsa-mir-200a level in oscc and healthy controls groups. salivary mir-200a was present at lower level in saliva of oral squamous cell carcinoma patients than in healthy controls, this in agreement with park et al. (1) who found mir-200a has been reported to be differentially expressed in head and neck cancer cell lines and other cancer cells (12-14). interestingly, in the present study, mir-200a was present at lower level in saliva of oscc patients compared to healthy controls in contrast to jiang et al. and tran et al. (12,14) who found that mir200a is present at higher levels in various oral squamous cell carcinoma lines. this discrepancy could be due to observing cell-free state of mirnas compared with the ones in living cells. because the supernatant saliva is the cell free phase of saliva, some of the mirnas in supernatant saliva are likely byproducts of cell death. it is possible that cancer specific mirnas undergo a more rapid degradation and/ or have a shorter half-life during the death, similar to the degradation of regulatory mrna (1). the result of the present study is also in agreement with wiklund et al. (15) who found that mir -200a was present at lower levels in oral rinse from oral squamous cell carcinoma patients compared to healthy controls; however they observed no change in the level of this mirna in saliva. for this reason mir-200a was suggested to function as putative tumor suppressors (16). salivary hsa-mir-125a level in oscc and healthy controls group this study revealed that salivary mir-125a was up-regulated in oscc group with no significant difference in the level of between oscc and healthy controls groups. this suggests that mir-125a may play an oncogenic role. in contrast park et al. (1) found that saliva mir-125a was significantly different between the two groups and was present at lower level in oscc patients than in healthy controls. similarly kozaki et al. (17) found that mir-125a was downregulated in oscc cell lines. the oncogenic role of mir-125a was demonstrated by zhang et al. (19) who found that mir-125a translationally arrests mrna of the p53 tumor suppression. the basis of this activity is the high degree of sequence homology since the 3'-utr of p53 harbors a sequence motif that is identical to the seed sequence (nucleotides 2-7 from the 5'end) of mirna125a. this finding added mirna-125a to the growing list of mirna with oncogenic targets (17-19). reversely deo et al. (10) revealed that mir125a may function as tumor suppressor for breast cancer with human antigen r (hur) as a direct and functional target. through transient transfection studies, mir125a with its homolog mir-125b have been shown to reduce erbb2 and erbb3 oncogenic proteins levels in skbr3 cells, a human breast cancer cell lines (20) if mirnas are drivers of oncogenic and tumor suppressor pathways, this would expect to find mirnas mutations can also be causative of the disease (21). as a matter of fact single nucleotide polymorphisms (snps) associated with mature mir-125a has been reported by duan et al. (22). it seems that a comprehensive study should include sequencing of the mirna as well to rule out the presence of polymorphisms and point mutations in mirnas sequences before establishing an exact role in oscc tumorgenesis (22). salivary hsa-mir-93 level in oscc and healthy controls groups the results of this study showed that mir-93 was up-regulated in patients with oscc compared with healthy controls. although this up regulation did not reach a significant level (probably due to the sample size) it still relates this mirna to the oscc formation, probably in an association with other mirnas, this in agreement with park et al. (1) who found that salivary mir-93 was not significantly different (p=0.17) between oscc and healthy controls groups. angela et al. (23) found that the mir-106b-25 cluster which is comprising from (mir-106b, mir-93 and mir-25) were up-regulated in all cell lines of head and neck cancer, because all these mirnas are located in intron 13 of the mcm7gene and this region are frequently amplified in hnscc (23-26). they also suggested a biological significance of the mir-106b-25 cluster (mir-106b, mir-93 and mir-25) in hnscc indicating that over-expression of this cluster might play an oncogenic role, perhaps mediated by e2f1 activation and impaired tgf-β signaling, ultimately resulting in uncontrolled proliferation, dysregulated cell cycling and increased invasiveness. fang et al., demonstrated that mir-93 function as oncogene through enhancing tumor cell survival, blood vessel formation and tumor metastasis by targeting lats2. they suggest that mir‑93 can potentially target a great number of genes, some acting directly on tumorigenesis and angiogenesis. others may only indirectly affect tumorigenesis and angiogenesis (27) j bagh college dentistry vol. 26(3), september 2014 the validity of salivary oral diagnosis 69 fang et al. (28) examined the function of mir93 in angiogenesis and tumor formation. in vivo studies revealed that mir-93-expressing cells induced blood vessel formation, allowing blood vessels to extend to tumor tissues in high densities. angiogenesis promoted by mir-93 in return facilitated cell survival, resulting in enhanced tumor growth. table 1: the case-control difference in mean normalized ct values of 3 selected mirna variables case-control comparison sig. controls cases (oscc) p (t-test) normalized ct value for hsa-mir-200a <0.001 range (0.91 1.11) (0.98 1.12) mean 1.01 1.06 sd 0.05 0.04 se 0.009 0.008 n 27 26 normalized ct value for hsa-mir-125a 0.34[ns] range (0.93 1.15) (0.88 1.09) mean 1.01 0.99 sd 0.05 0.05 se 0.01 0.009 n 26 27 normalized ct value for hsa-mir-93 0.1[ns] range (0.79 1.12) (0.82 1.1) mean 0.99 0.95 sd 0.08 0.07 se 0.015 0.014 n 27 27 table 2: roc area under the curve for 3 tested mirna in the context of discrimination between cases with oscc and healthy controls. variables auc p normalized ct value for hsa-mir-200a 0.781 <0.001 normalized ct value for hsa-mir-93 0.650 0.06[ns] ct value for hsa-mir-93 0.613 0.16[ns] ct value for hsa-mir-200a 0.575 0.35[ns] ct value for hsa-mir-125a 0.553 0.51[ns] normalized ct value for hsa-mir-125a 0.536 0.66[ns] table 3: linear correlation coefficient controls normalized ct value for hsa-mir200a normalized ct value for hsa-mir125a normalized ct value for hsa-mir-125a r=0.111 p=0.59[ns] normalized ct value for hsa-mir-93 r=-0.74 p<0.001 r=-0.717 p<0.001 cases normalized ct value for hsa-mir200a normalized ct value for hsa-mir125a normalized ct value for hsa-mir-93 normalized ct value for hsa-mir-125a r=0.381 p=0.05[ns] r=1 p<0.001 r=-0.799 p<0.001 normalized ct value for hsa-mir-93 r=-0.843 p<0.001 r=-0.799 p<0.001 r=1 p<0.001 j bagh college dentistry vol. 26(3), september 2014 the validity of salivary oral diagnosis 70 figure 1: roc curve showing comparing the area under the curve for hsa-mirna-125a and hsa-mirna-93 in the context of discrimination between cases with oscc and healthy controls. (higher ct values are in favor of controls). figure 2: roc curve showing comparing the area under the curve for hsa-mirna-200a in the context of discrimination between cases with oscc and healthy controls. 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23: 2484–98. 27. fang l, du ww, yang w, rutnam zj, peng c, li h, o'malley yq, askeland rw, sugg s, liu m, mehta t, deng z, yang bb. mir-93 enhances angiogenesis and metastasis by targeting lats2. cell cycle 2012; 11:23, 4352-4365. 28. fang l, deng z, shatseva t, yang j, peng c, du ww, yee aj, ang lc, he c, shan sw, yang bb. microrna mir-93 promotes tumor growth and angiogenesis by targeting integrin-β8. oncogene 2011; 17; 30(7): 806-21. dhuha.doc j bagh college dentistry vol. 27(1), march 2015 biomechanical evaluation restorative dentistry 18 biomechanical evaluation of porous titanium implants (cpti) fabricated by powder technology dhuha hussein mohammed, b.d.s. (1) widad a. h. alnakkash, b.d.s., h.d.d., m.sc. (2) abstract background: it may be an important prospective clinical use of manufacturing of porous implant for clinical situations, such as cases of limitation in bone height, low bone density .the small segment of porous implant an effective osseointegration allows increasing in contact area provided for small segmented porous provided by its surface configuration. this study was done to fabricate porous titanium implants by powder technology, as well as the observation of removal torque values of porous titanium implants compared to smooth titanium implants. materials and methods: twenty porous titanium implants (3.2mm in diameter and 8mm in length) were manufactured by powder technology using commercially pure titanium powder of ≤75um particles size, with polyvinyl alcohol powder of 212-300um particle size, as a space holder, by volume ratio (70:30) % respectively. the mixed powder was compacted using punch and die set -specially designed for this study –under 20 bar then sintering at 900 ºc by the use of argon gas. twenty smooth titanium implants were prepared of (3.2mm in diameter and 8mm in length) by lathing of commercially pure titanium rod as a control group. the implants were examined by x-ray diffraction (xrd) and scanning electron microscope (sem), as well as estimation of porosity percentage. for each tibia of the 20 white new zealand rabbits, one implant of each type (one porous in right, and the smooth in left tibia), were inserted through surgical procedure carried under serial condition. mechanical test was performed to evaluate the boneimplant interface, after (2 and 6 weeks) healing periods . results: porous implants were obtained successfully by powder technology with 52% porosity and pore size 210um 17±. the porous implant showed significantly higher removal torque values when compared to smooth implants at the two different intervals of examination (2,6 weeks) , this proved to be statistically highly significant, also a highly significant difference was noticed for the means of the torque removal values in the same group at different implantation , with no evidence of clinical features of inflammatory reaction with both . conclusions: powder technology seemed to be particularly advantageous in fabrication of porous titanium. porous implant show an increasing bone ingrowth compared with the smooth type represented by higher removal torque for both healing periods (2, 6) weeks . key words: porous titanium implant, powder technology, removal torque test. (j bagh coll dentistry 2015; 27(1):1825). introduction lost body structures are replaced by surgical implants gaining the goals of becoming the most promising fields, improving quality of life with the increase in expectancy of population. the most commonly commercially biocompatible material used for the manufacturing of surgical implants are metals, with titanium being the most commonly used metals in the field of biomedicine presenting excellent physical and chemical properties there are two main groups of titanium according to manufacturing process the casting and powder technology (1,2). at present, however, the fabrication of tibased implants through the casting method is limited to a costly, multi-step process of vacuum melting machining, which is costly with the limited use the high melting temperature of ti (3,4). the advantage of using powder technology (powder metallurgy is due to its processing route with limited cost (5). (1) master student, department of prosthodontics, college of dentistry, university of baghdad. (2) professor, department of prosthodontics, college of dentistry, university of baghdad. in powder technology pores can be found from removal of spacer particles with increasing porosity which is crucial for bone ingrowth. "bone in growth", is the osseointegration gained by micromechanical interlocking between the bony tissues and porous structure of the implant which representing strong implant-bone bond thus increasing stability and preventing mobility. these pores can be interconnected threedimensionally, which in turn provide enough space for the attachment and proliferation of new tissues thus facilitating the transport of body fluids (6,7) the applications of porous implants being ranged from spinal fixation to hip prostheses, osteosynthetic plates, and dental implants (8). materials and methods commercially available titanium powder particle size ≤75 um was used. firstly pva particles were milled using mill to powder then sieved using two sieves 212um and 300 um. pva with average particle size (212-300 um) was used. pilot study was done to find the best percentage for porous titanium implant five percentage were tested after mixing by volume j bagh college dentistry vol. 27(1), march 2015 biomechanical evaluation restorative dentistry 19 ratio(90:10) %, (80:20)%, (70:30)% , and (60:40)% (50: 50)% titanium powder and pva respectively. the (70:30) % titanium-pva was selected. the pressure of 20 bar was selected as the best amount of pressure to be applied. the condensation time of 60 seconds was selected. sintering was performed by carbolite furnace using argon gas under 900 c. preparation of samples for the tests by ultrasonic cleaning using: distilled water, acetone solution, ethanol solution, finally distilled water for 20, 20, 20, and 15 min, respectively (9). two implants were placed in a single air tight plastic sheet (one implant from each group) then the implants were autoclaved at (121°c and 20 bar) for 30 minutes, as was performed by xue xb et al. (10). figure 1-a.stereomicroscope, (b, c implants as appearing under stereomicroscope) b .cylindrical compacted implant before sintering, c. cylindrical compacted after sintering examine implants sem sem and stereomicroscope images observation of the porous and smooth titanium samples was carried on to reveal the micrograph. x ray diffraction analysis phase analysis was employed for cp-titanium powder and porous titanium samples using shimadzu lab xrd6000 powder x-ray diffract meter and cu kα target radiation .the 20 angles were swept from 2080° in step of one degree each time porosity test the density and porosity of the consolidated samples were measured using archimedes (9)(11). sample distribution before surgery 40 implants were placed into 20 rabbits and were divided into: a. control group (smooth implant): this group includes 10 implants for each healing interval (2 and 6weeks) implanted in 10 rabbits. b. experimental group (porous implant): this group includes 10 implants for each healing interval (2 and 6 weeks) implanted in 10 rabbits. animals and surgical procedures twenty new zealand white rabbits of both sexes weighing 2-2.5 kg were used .the age of the animals was from 10-12 months. animals were kept in standard separate cages and had free access to tap water, and were fed with standard pellets. they were left for 2weeks in the same environment before surgical operation. antibiotic cover with ox tetracycline 20% (0.7ml/kg) intramuscular injection was given to exclude any infection (one dose/day, for 3 days). all instruments were autoclaved at 121 c ˚and 20 bars for 30 minutes. the required dose of anesthesia and antibiotic was calculated by weighing each rabbit in a special balance for the animals. anesthesia was induced by intramuscular injection of ketamine hydrochloride 50 mg (1ml/kg body weight), xylazine 20% (0.15ml/ kg body weight).and xylocaine 10% (1ml/ kg body weight). surgery was performed under sterile condition and a gentle surgical technique. incision was made on the medial side of the legs about (3cm) length to expose tibia bone. the skin, fascia the periosteum were carefully reflected. drilling was done using round bur with intermittent pressure and continuous cooling with normal saline at rotary speed 1500 rpm and reduction torque 16.1. the enlargement of the hole was made gradually with spiral drill from 2.2 mm 2.9 mm till 3.1 mm the operation site was cleaned with copious amount of saline to remove bone shreds; the implants were removed from the plastic sheet and placed in holes with slight tapping pressure until 5mm was completely introduced into bone. suturing of fascia was done with absorbable cat gut suture followed by skin suturing .the operation side was washed with normal saline followed by bandaging. post-operative care, performed by giving an antibiotic (local and systemic) for 5 days after surgery. torque removal test the animals that categorized for mechanical test were anesthetized with the same type and dose that used in the implantation procedure. incision was made at the medial side of tibia; muscle and fascia were reflected to expose implants. j bagh college dentistry vol. 27(1), march 2015 biomechanical evaluation restorative dentistry 20 the stability of implant checked by the end of head of torque meter, tibia was supported firmly while performing mechanical test to prevent any movement, which may have an affects on the accuracy of the test. a torque removal test was done by the torque meter to determine the peak torque necessary to loosen the implant from its bed, through the torque meter head manufactured for the measuring purpose of this study. results sem observations 1. the sem image observation of the porous titanium samples shows the surface morphology fig. (2),(3). the pore space structure after space holder removal displays ragged shaped macropores inside the sintered material, where the number and the size of spaces can be evaluated. on the other hand a three-dimensional interconnected pores was clearly observed between the pores. fig (3), (4). 2. the sem observation of the smooth titanium samples fig (5) figure 2: sem of porous titanium implant figure 3: sem of porous titanium sample showing the macropore figure 4: sem of porous titanium sample shows the interconnected pores x-ray diffraction phase analysis the x-ray diffraction pattern of untreated commercially pure titanium powder and the sintered commercially pure titanium implants are shown in fig (6). it is clearly obvious that the strongest peaks of powder were at (100) , (002) , (101) and(102) at 2ө 35.20 , 38.48 , 40.27 ,and 53.08 respectively which could be indexed for αtitanium (jcpds file 44.1294) . figure 5: sem illustrates topography of smooth titanium implant figure 6: x-ray diffraction patterns of ti implant and ti powder j bagh college dentistry vol. 27(1), march 2015 biomechanical evaluation restorative dentistry 21 also the pattern shows strong peaks of the sintered commercially pure titanium implants at (101), (101), (002), and (102) at 2ө 40.23, 40.08, 38.18, and 53.23 respectively and this pattern is corresponding to the powder and responsible for αtitanium (jcpds file 44.1294) clinical observation all animals recovered well after surgery presenting clinically satisfactory postoperative results as an indication of good tolerance for the implantation procedure, with no clinical evidence of inflammation or infection at the surgical site torque removal test the removal torque values of porous titanium implant after 2 weeks of implantation. where at that interval, a higher torque values was needed to remove porous implants (mean value of 13.77 n.cm) compared to the torque value needed to remove smooth titanium implants (mean values of 8.27 n.cm ) (figure 7). figure 7: the removal torque mean values of the smooth and porous titanium implants after 2 weeks interval descriptive statistics of removal torque values at 6 weeks after implantation, where higher torque force was required to remove the porous titanium implants (mean value of 18.79 n.cm) compared to that needed for smooth titanium implants (mean values of 13.55 n.cm) fig (8) figure 8: the removal torque mean values of the smooth and porous titanium implants after 6 weeks interval effect of time on removal torque value both coating materials showed increased torque removal force between 2 and 6 weeks of implantation which was statistically highly significant. figure 9 figure 9: the summary of the differences in the torque mean values between all groups. table (1) shows t-test for equality of means of torque values between porous and smooth titanium implants at 2 weeks healing period where showed a highly significant difference, also at 6 weeks as illustrated in (table 2) table 1: t-test for equality of means of torque value for porous and smooth implants at 2 weeks interval types of implant (at 2weeks ) t-test df sig. (2-tailed) sig porous × smooth 15.77 18 .000 hs table 2: t-test for equality of means of torque value for porous and smooth implants at 6 weeks interval types of implant (at 6 weeks ) t-test df sig. (2tailed) sig porous × smooth 15.86 18 .000 hs t-test was performed for comparing the equality of means for the same group at the different implantation periods. a highly significant differences at p<0.010 between each subgroup of the two periods of examine times. it was clearly obvious that the torque value needed to remove implants from the bone was increased as healing period increased. torque value n.cm torque value n.cm torque value n.cm j bagh college dentistry vol. 27(1), march 2015 biomechanical evaluation restorative dentistry 22 table 3: t-test for equality of means of torque value within the same group at different time interval 2&6 weeks interval. type of implants time in weeks n mean s.d. t-test sig. porous 6 10 18.79 .77 14.617 hs 2 10 13.77 .84 smooth 6 10 13.55 .70 17.234 hs 2 10 8.27 .71 s : significant at p<0.05 discusion around the biomechanical area the resent use of powder technology is of great advantage for the final format of prosthesis production dense or porous and less expensive than the conventional (6,7,12). 1 part one in vitro study 1.1 selection of powder percentage and particles size the reason behind choosing the volume percentage of 30% pva -70% titinuim powder, was because implant surface morphology is considered important for ossiointegration, since fibrin clot retention and bone progenerater cell migration are related to surface topography is associated . the use of large particle size for space holder (pva), and fine particle size for ti, could be due to both a wider pva particles distribution (which promotes a higher degree of interconnectivity of the pores) and a high average size of space-holder (>200um )which would fulfill the requirements to ensure the growth of bone into the implant (ingrowth); on the other hand, the choice of a titanium powder of small average size would improve the sinter ability of the compact (quality of the neck and lower grain size), helping to offset the loss of mechanical strength inherent in increased porosity. 1.2 powder compaction and problems associated with it: punch and die set was designed in a way that ensure proper condensation of porous titanium implants .the powder / spacer material mixture was compacted using the hydraulic press with a pressure of 20 bar for 60 seconds, genuinely determined by trial and error in order to get the good quality for producing "green strength " that allowed enough handling strength. the pilot study showed that when powder / spacer material mixture was compacted at a pressure higher than 20bar with a holding time of more than 60 seconds, the compact became very hard with difficulty in ejecting the pellets from the mold and with a tendency to damage the punch .it was also noted in the pilot study that the compaction pressure should not be used when holding time less than 30 seconds. it could be understand that when the pressure is too high a considerable proportion of binder would be crushed during compaction this finding coincide with xb xue et al. (10). while through the compaction of powder before sintering one can improve the mechanical properties (12,13). the loss of interconnectivity in between the powder particles may be caused by loose packing of powder mixture (14). generally, higher compaction pressure increased the densification of the ti powder. heat treatment in sintering (thermal treatment ) the classic melting was substituted , and carried out below the melting point of the metal .in the pattern fig.(6)of the xrd phase analysis showed that in sintered titanium implants, heating was carried on using argon gas to provide a non oxidizing environment ; and this explained by in that the ti and its alloys may have high affinity towards interstitial elements like oxygen and nitrogen required a non oxidizing environment thus reducing the residual surface oxide in order to improve the metallic contact between adjacent powder particles as stated by gasser, nyberg et al. and ryan et al. and nouri et al. (34,15,16).on the other hand conventional processing of molten metal to fabricate porous metal is suffering from limited part geometries, and limited control over the size, shape and distribution of porosities , contamination, costly, multi-step process (17). this in turn can confirmed that in particular, the casting method is unpractical for manufacturing of porous ti based scaffolds, due to the high melting point and the high affinity of ti towards oxygen and special refractory materials during the manufacturing process and these support the findings of ryan et al. 15.these difficulties driven the researchers to a more cost affordable manufacturing methods with minimal waste product (3). scanning electron microscope the sem image observation of the porous titanium samples revealed the micrograph of the porous cylindrical implants upon the removal of the space holder (18). the pore-space structure in the sintered material contains different types of pores; macro-pores, determined by the number and size of the space holder materials fig (2, 3and4), also sem images showed clearly, j bagh college dentistry vol. 27(1), march 2015 biomechanical evaluation restorative dentistry 23 interconnected pores. the average pore diameter was about 210μm (± 17), and 52% total porosity. this agreed with elema et al. (19) who proposed that the pore size should range from 200 to 300 μm for bone tissue in growth in the porous samples; although they did their study about biodegradable porous polymeric implants. small pores could favor hypoxia, which can result in the formation of osteocartilaginous tissue, while large richly vascularized pores permit direct osteogenesis and thus resulting in an improved bone implant interface (20).in addition to the presence of pores with more ragged and rough surfaces as seen in fig 3.5 offering larger surface area for bone ingrowth (21). both the open porosity and pore interconnectivity are necessary for bone ingrowth, and extensive body fluid transport through the porous implants possible, thus trigger bone growth. it is also known that the pore size itself is less important than the amount of interconnectivity for new bone formation .this agrees with chen et al. and nouri et al. (22,23) with the difference in material and technique used . in the present study the observation of the sem image can give a good indication of the packing of the powder mixture at a given sintering process. porosity the porous structure of the alloys is important for the growth of bone inside the implant body and thus will improve the fixation and stability and the remodeling between the implant and the human tissue (24); by providing space for cell adhesion and permitting the transport of body fluids and thus leads to acceleration in the proliferation of new vasculature, while providing adequate mechanical properties to withstand stresses during surgical procedure and use (1). this agrees with ryan et al. and vasconcellous et al. (6,15) but with the difference in material, method that used. the total porosity percentage of the fabricated porous implants after porosity test was within 52% as used in this study which could be an alternative for clinical use, for the reason that increased porosity may permit the growth into pores and subsequent mineralization. many authors have been suggested that the percentage of pores preferable for ti samples is between (25-66%). however, samples reaching till 80% porosity have also shown bone formation (25-27). on the other hand the percentage of the open porosity was 33% while the percentage of closed porosity was 19% .pores are usually surrounded by pore walls and disconnected from each other in closed –cell porous implant structure, while in open-cell porous implant structure, pores are connected to each other, thus ensuring fixation of implants as new bone tissue grows and integrate into the this is in agreement with banhart and shehata aly et al. (28,29). part two in vivo study implant preparation prior to surgery in this study the size of the holes created in the bone were (3.1mm)which was smaller than the diameter of the implant(3.2 mm) and this in turn would result in a better surgical fit, and as a consequence, force-fitting stress increases installation torque and initial stability and this agree with skalak and zhaoin and waheed (30,31) with the differences in material, method, technique, and shape used in this study. mechanical test the removal torque value (rtv) is the torsion force required to remove an implant and this value represent the critical torque threshold where implant contact was destroyed. this would indirectly provide information about the amount of bone -implant contact for a given implant. such testing was carried out on experimental animals model, where the rabbit tibia are the most frequently bone components cited in literatures alnajar et al and gonzalez et al. (32,33). the increase in the amount of cortical bone in contact with the implant required greater removal torque forces where the surface of the implant is often porous thus increasing bone/implant interface which consequently will increase the bony ingrowth into the surface irregularities of the implant (34). tables (1 and 2) demonstrates t-test for equality means of the removal torque values of the porous titanium implants and the smooth titanium implants at the two implantation testing periods (2 and 6 weeks). it showed statistically highly significant difference; which indicates minimum removal torque values associated with smooth implants group, while the maximum removal torque values were associated with porous implants group thus suggesting that the pore structure for the porous implants provide more surface area and space for bone ingrowth as well as mechanical interlocking between the implant and bone. the surface area and contact surface configuration are important parameters for implant stability. when there is little or no mechanical interlocking between the implant surface and bone, any excessive loading may j bagh college dentistry vol. 27(1), march 2015 biomechanical evaluation restorative dentistry 24 cause rupture at the bone-implant interface . this mechanical interlock should enhance the strength of the boneimplant interface. as well as the force needed to extrude the bone through the porosities may be much higher than the bone mechanical strength itself. this agrees with wazen et al. (35) with the difference in the material, method. implant porosity promotes positive results in bone neoformation in vivo since it facilitates the transport of body fluids, aids in the spread of cells into the implant. improving the implant stability over time is gained through increase in contact area between bone tissue and implant this in turn promoting the proliferation of bone tissue through a mechanism which is not usually observed on flat or rough surfaces ,on the other hand the process of osseointegration is accelerated as claimed by bottino et al., vanconcellos, wazen et al. and faria et al. (6-8, 35,36) with difference in the material , method technique and shape of implant used in this study. the removal torque method selected in this study is used for the first time shows the correlation between the force necessary for removal of the porous implants and the degree of bone implant integration and it focuses on interfacial shear properties. the amount of integration in rt method may be affected by implant geometry and topography as stated by waheed and alnajar (31,32) but on the other hand the material and the technique and shape are not the same and are used for the first time. table (3) showed the result of t-test for equality for means of removal torque value within the same group at the different implantation periods shows a highly significant difference, which means that the minimum torque value was seen within 2 weeks of implantation periods, while the maximum value was observed in the 6 weeks implantation periods for both the porous and smooth groups. it was noticed in this study that the torque value significantly increased with time for both the porous and smooth implants .these results may suggest increased holding power and anchorage of implant with time due to progressive bone formation around the implant during healing period and consequently improved mechanical capacity due to maturation of bone with elapsed of time. references 1. rosa al, crippa ge, oliveira pt, taba mj, lefebvre lp, beloti mm. human alveolar bone cell proliferation, expression of osteoblastic phenotype, and matrix mineralization on porous titanium produced by powder metallurgy. clin oral implant res 2009 20: 472–81. 2. bhattarai sr, khalil ka, dewidar m, hwang ph, yi hk, kim hy. novel production method and in-vitro cell compatibility of porous ti-6al-4v alloy disk for hard tissue engineering. j biomed mat res a 2008; 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12: 72-9. الخالصة ال السریري في حاالت محددة منھا عدم تمتع العظم بواصفات جیدة من حیث النوعیة أو االبعاد الكافیة الستقبال لتسھیل عملیة تصنیع غرسات مسامیة لالستعم:خلفیة الموضوع . ةحیث من الممكن للزرعات المسامیة ذات االبعاد الصغیرة ان تسمح بنمو عظمي فعال وذلك بسبب سعة المساحة السطحیة للتركیب المسامي للغرس.الغرسات لغرض ایجاد فعالیة وتاثیر مسامیة الغرسات ذات التركیب المسامي على تعزیز التماسك المیكانیكي بین العظم . المساحیقسات التیتانیوم المسامیة بطریقة تكنولوجیا تصنیع غر:االھداف . والزرعة 75≥باستخدام مسحوق التیتانیوم النقي التجاري بحجم حبیبي المساحیقورجیا بطریقة میتال)ملیمیتر طوال8-ملیمیتر قطرا 3.2(غرسة مسامیة بابعاد ) 20(تم تصنیع : المواد واالدوات بار في داخل قالب 20وتعبئتھا باستعمال ضغط , بالتعاقب %30:70كماسك للفراغ بنسبة حجمیة مئویة ) مایكرون 300-212(مایكرون مع مادة الكحول البولي الفنیلي بحجم حبیبي .مئویة باستعمال غاز االركون 900ثم معاملتھا حراریا بدرجة , صول على عینات مضغوطةاعد خصیصا لھذه الدراسة للح فحص : ومن ثم اجریت بعد ذلك الفحوص االتیة . الستعمالھا كمجموعة قیاسیة غیر معالجة ) ملیمیتر طوال 8-ملیمیتر قطرا 3.2(من مادة التیتانیوم النقي , غرسة ملساء 20حضرت .كما وتم فحص التركیب الدقیق للعینات باستخدام المجھر االلكتروني . السینیة للسطوح للغرسات المسامیة ومسحوق التیتانیوم النقي باالضافة لفحص المسامیة انحراف االشعة اجریت .واحدة في كل ساق ) غرسة مسامیة وغرسة ملساء (حیث استلم كل ارنب اثنین من الغرسات ,ارنبا من االرانب النیوزلندیة البیضاء مكانا للزراعة 20اختیر عظم الساق ل وزعت .اسابیع من مدة الشفاء ) 6و 2(العملیة الجراحیة تحت ظروف معقمة ومن ثم تم اجراء الفحوص المیكانیكیة لفھم طبییعة السطح البیني للعظم وغرسة االسنان بعد مضي . خصصت لفحص العزم الالزم لنزع الغرسة من العظم) مسامیة 20ملساء و 20(غرسة 40:الغرسات كاالتي مایكرون بطریقة تكنولوجیا المساحیق حیث اظھرت الغرسات المسامیة تفاعل اسرع مع ) 17 .±210(وبحجم مسامیي % 52تم انتاج غرسات اسنان ذات مسامیة تصل الى : النتائج فترتي االختبار وقد اظھرت نتائج العزم الالزم لنزع الغرسات المسامیة من العظم قیما اعلى احصائیا وبشكل واضح عند مقارنتھا مع الغرسات الملساء خال العظم من الغرسات الملساء من جھة اخرى الفحوص النسیجیة قد بینت بشكل .اسابیع كما انھ كانت ھناك نتائج اعلى للعزم الالزم لنزع الغرسة داخل كل مجموعة وبتناسب طردي مع طول فترة الشفاء ) 6و 2( .واضح تكون عظم جدید بمالصقة الغرسات باالضافة الى تحسین استجابة العظم للغرسات المسامیة بالمقارنة بالغرسات الملساء كما اظھرت الغرسات . وبسیطرة على نسبة المسامیة وحجم المسامات اظھرت تكنولوجیا المساحیق فائدة عملیة في تصنیع غرسات التیتانیوم المسامیة وذات مسامات متصلة : االستنتاج .المسامیة قیما اعلى للعزم الالزم لنزع الغرسات من العظم مقارنة بالغرسات الملساء ولكتا فترتي الشفاء shanaz f.doc j bagh college dentistry vol. 25(2), june 2013 clinicopathological oral diagnosis 101 clinicopathological analysis of common oral lesions shanaz m. gaphor, b.d.s., m.sc., ph.d. (1) mustafa j. abdullah, b.d.s., m.sc. (2) abstract background: oral health is important to the quality of life of all individuals. oral lesions can cause discomfort or pain that interferes with mastication, swallowing, and speech. oral disease is a health problem that is not only a matter of oral hygiene and local condition, but can also be a precursor to other dangerous and potentially life threatening illnesses. the present study was designed to analyze the main clinicopathological aspects of most common oral lesions in patients who visit the oral diagnosis clinic of the college of dentistry, university of sulaimani, kurdistan region, iraq. patients and methods: this prospective study was performed on 3144 patients from july 2009-july 2010. in this study a total of 3144 patients were examined. of these 1507 (47.93%) were males and 1637 (52.06%) females. the patients' age ranged between 10 to 79 years. an interview was conducted to collect information using a structured questionnaire which was completed by each patient. the lesions that could not be diagnosed by clinical examinations alone were analyzed histopathologically. results: among 3144 patients, only 799 patients (25.41%) had oral lesions. females constituted 49.81% (n=398) and males 50.18 (n=401). the age range of the patients was between 10-79 years with a mean age of 33.75 years. anatomic changes and developmental anomalies were considered as linea alba (16.68%), fordyce's granules (12.37%), torus mandibularis (0.66%), torus palatinus (0.55%). common oral lesions after those considered being anatomic changes and developmental anomalies were fissure tongue (18.23%), cheek biting (12.15%), hairy tongue (6.51%), and recurrent aphthous stomatitis (5.85%) , ankyloglossia (3.75%) , lingual varicosities (2.87%) , frictional (traumatic) keratosis (2.87%) , denture stomatitis (2.54%), recurrent herpes simplex virus infection (2.43%), traumatic ulcer (2.43%), geographic tongue (1.98%), fibroepithelial hyperplasia (1.32%), denture induced fibrous hyperplasia (1.21%) , angular cheilitis (0.99%) , oral lichen planus (0.88%) , median rhomboid glossitis (0.88%) , peripheral giant cell granuloma (0.22%) , and gingival hyperplasia (0.33%) . conclusion: routine examinations of oral cavities are valuable in identifying several oral lesions and this will help to establish early diagnosis and treatment and better prognosis particularly early precancerous and other oral lesions. keywords: abnormalities, oral mucosal lesions, clinicopathological. (j bagh coll dentistry 2013; 25(2):101-107). introduction oral health is important to the quality of life of all individuals. oral lesions can cause discomfort or pain that interferes with mastication, swallowing, and speech. oral lesions can produce symptoms such as halitosis, xerostomia, or oral dysesthesia, which interfere with daily social activities (1). oral disease is a health problem that is not only a matter of oral hygiene and local condition, but can also be a precursor to other dangerous and potentially life threatening illnesses (2). diagnosis of wide variety of lesions that occur in the oral cavity is an essential part of dental practice. an important element in establishing a diagnosis is knowledge of the lesions’ relative frequency, or prevalence at one point in time (3). among the broad spectrum of causes leading to changes in the oral mucosa are infections from bacteria, fungi, viruses, parasites, and other agents; physical and thermal influences, changes in the immune system, systemic diseases, neoplasia, trauma and other factors, some of which are issues of aging (4,5). traditionally, the mucosal membrane of the oral cavity has been looked upon as mirroring the general health (6). (1)assistant professor. department of oral medicine, college of dentistry, university of sulaimani. (2)assistant lecturer department of oral medicine, college of dentistry, university of sulaimani. the tongue lesions fissured, geographic and hairy tongue, oral lesions fordyce granules, and leukoedema are classically considered to be developmental oral lesions rather than having virtual disease characteristics (6). these lesions may be present at birth or become evident later in life. they may be discovered during routine dental examinations and vary depending on age, gender and/or race (7). recurrent aphthous stomatitis is an ulcerative condition that affects the oral mucosa without evidence of an underlying medical disorder, or may be associated with other systemic diseases (8). in particular, long-term habits such as using tobacco can cause precancerous or cancerous lesions (9). dental factors (poor oral hygiene, sharp teeth, and improperly fitting dentures) have been thought to play a role in the occurrence of oral mucosal lesions (4,10). denture wearers, besides suffering the characteristic lesions from the dentures, they present traumatic ulcerations with more frequency than nonusers, candidosis pathology occupying second place in frequency (11). the present study was designed to analyze the main clinicopathological aspects of most common oral lesions in patients who visit the oral diagnosis clinic of the college of dentistry, university of sulaimani. j bagh college dentistry vol. 25(2), june 2013 clinicopathological oral diagnosis 102 patients and methods evaluation basis: this prospective study was performed on 3144 patients, of these 1507 (47.93%) were males and 1637 (52.06%) were females. the patients' ages were between 10 to 79 years. all patients included in this study were referred to the department of oral medicine, college of dentistry, university of sulaimani from july 2009-july 2010. the bases for attending to the clinic were to seek dental treatment. patients: an interview was conducted to collect information using a structured questionnaire which was completed by each patient and the examiner. both dental and general medical histories of the patients were obtained. methods: the patients were examined clinically by two trained examiners using artificial light, mouth mirror, gauze. at the time of clinical examination, we established a preliminary diagnosis. some of the mucosal changes where diagnosed solely by clinical examination (e.g. linea alba, fissured tongue, etc.). some times a cotton swab was used to remove evident debris; a swab was always used to test whether a white lesion could be wiped off. in some cases where the observed lesion could be of traumatic origin, this was eliminated and the patients were requested to return for evaluation 15 days later for a new exploration. during the clinical examination, the following elements including features of the lesion, anatomical location, extension, etiological factors or related factors, dental status were analyzed. the diagnosis was made based on history, clinical features, and investigations according to the who (1997) criteria (12). when clinical features were not diagnostic and where no clinical improvement was observed, a biopsy was undertaken. results among 3144 patients examined, 905 oral lesions were diagnosed and their distribution was as follows: distribution of tongue disease according to age and sex in 905 oral lesions: tongue lesions were considered as fissure tongue (18.23%), black hairy tongue (6.51%), ankyloglossia (3.75%), geographic tongue (1.98%) and scalloped tongue (0.33%) as shown in table (1). table 1: distribution of tongue diseases according to age and sex in 905* oral lesions tongue diseases sex age (y) subtotal n (%) total n (%) % (905) lesions 1019 2029 3039 4049 5059 6069 7079 fissured tongue female 4 22 23 12 10 3 2 76 (46.06) 165 18.23% male 6 45 13 6 3 13 3 89 (53.93) (-54.09) black hairy tongue female 0 3 3 0 6 0 1 13 (22.03) 59 6.51% male 0 21 7 5 4 5 4 46 (77.96) (-19.34) ankyloglossia female 2 7 0 0 1 0 0 10 (29.41) 34 3.75% male 6 14 3 0 0 1 0 24 (70.58) (-11.14) lingual varicosities female 0 0 2 4 5 0 0 11 (42.30) 26 2.87% male 0 0 0 0 mad mom 0 15 (57.69) (-8.52) geographic tongue female 2 7 2 0 0 0 0 11 (61.11) 18 1.98% male 0 7 0 0 0 0 0 mom (38.88) (-5.9) scalloped tongue female 0 1 1 0 0 0 0 2 (66.66) 3 0.33% male 0 1 0 0 0 0 0 1 (33.33) (-0.98) total female mad 40 31 16 22 3 3 123 (40.32) 305 33.70% male 12 88 23 11 15 26 8 182 (59.67) (-100) *some patients had more than one lesion, so the number of lesions was more than the number of the patients distribution of anatomic changes and developmental anomalies according to age and sex in 905 oral lesions: anatomic changes and developmental anomalies were considered as linea alba (16.68) followed by fordyce's granules (12.37%), torus mandibularis (0.66%), and torus palatinus (0.55%) as shown in table(2). distribution of ulcerative, vesicular and bullous lesions according to age and sex in 905 oral lesions: the most common ulcerative lesion was ras (5.85%) followed by recurrent herpes simplex virus infection and traumatic ulcer (2.43%) as shown in table (3). distribution of white lesions according to age and sex in 905 oral lesions: the most common white lesion was cheek biting (12.15%) followed by frictional keratosis (2.875%), oral lichen planus (0.88%) as shown in table (4). distribution of candidiasis according to age and sex in 905 oral lesions: the number of patients with denture stomatitis was 23, 18 patients were females whom constituted 78.26% j bagh college dentistry vol. 25(2), june 2013 clinicopathological oral diagnosis 103 and 5 patients were males whom constituted 21.73%. the number of patients with angular cheilitis was 9, 4 patients were females whom constituted 44.44% and 5 patients were males whom constituted 55.55% as shown in table (5). distribution of benign lesions according to age and sex in 905 oral lesions: the most common benign lesion was fibroepithelial hyperplasia (1.32%) followed by denture induced fibrous hyperplasia (1.21%) as shown in table (6). table 2: distribution of normal structural variants according to age and sex in 905* oral lesions normal structural variants sex age (y) subtotal n (%) total n (%) % (905) lesions 10-19 20-29 30-39 40-49 50-59 60-69 70-79 linea alba (white line) female 8 51 24 mad 5 0 0 96 (63.57) 151 16.68% male 5 28 17 3 1 1 0 55 (36.42) (-55.1) fordyce’s granules female 0 9 7 mom 5 2 0 30 (26.78) 112 12.37% male 1 32 22 10 9 7 1 82 (73.21) (-40.87) torus mandibularis female 0 2 1 2 0 0 0 5 (83.33) 6 (2.18) 0.66% male 0 0 0 1 0 0 0 1 (16.66) torus palatinus female 0 2 1 2 0 0 0 5 (100) 5 (1.82) 0.55% male 0 0 0 0 0 0 0 0 (00.00) total female 8 64 33 19 10 2 0 136 (49.63) 274 (100) 30.27% male 6 60 39 14 10 8 1 138 (50.36) table 3: distribution of ulcerative, vesicular and bullous lesions according to age and sex in 905* oral lesion ulcerative, vesicular and bullous lesions sex age(y) subtotal n (%) total n (%) % (905) lesions 1019 2029 3039 4049 5059 6069 7079 recurrent aphthous stomatitis female 6 16 3 2 2 0 0 29 (54.71) 53 (-53.53) 5.85% male 2 17 2 3 0 0 0 24 (45.28) recurrent herpes – simplex virus infection female 2 6 1 2 1 0 0 12 (54.54) 22 (-22.22) 2.43% male 1 7 2 0 0 0 0 10 (45.45) traumatic ulcer female 1 3 1 4 4 0 1 14 (63.63) 22 (-22.22) 2.43% male 0 5 2 0 0 1 0 8 (36.36) behçet’s syndrome female 0 0 0 0 0 0 0 0 (00.00) 1 (-1.01) 0.11% male 0 0 0 0 1 0 0 1 (100) erythema multiforme female 0 0 1 0 0 0 0 1 (100) 1 (-1.01) 0.11% male 0 0 0 0 0 0 0 0 (00.00) total female 9 25 6 8 7 0 1 56 (56.56) 99 (-100) 10.93% male 3 29 6 3 1 1 0 43 (43.43) j bagh college dentistry vol. 25(2), june 2013 clinicopathological oral diagnosis 104 table 4: distribution of white lesions according to age and sex in 905* oral lesions white lesions sex age (y) subtotal n (%) total n (%) % (905) lesions 10-19 20-29 30-39 40-49 50-59 60-69 70-79 cheek biting female 2 37 18 mom 2 0 0 66 (60) 110 12.15% male 1 34 6 3 0 0 0 44 (40) -72.84 frictional (traumatic) keratosis female 0 6 1 3 2 0 0 12(46.15) 26 2.87% male 1 7 5 0 1 0 0 14(53.84) -17.21 oral lichen planus female 0 1 1 1 2 0 0 5 (62.5) 8 0.88% male 0 2 0 0 0 1 0 3(37.5) -5.29 leukoplakia female 0 0 0 0 0 0 0 0 (00.00) 3 0.33% male 0 1 0 1 0 1 0 3 (100) -1.98 nicotine stomatitis female 0 0 0 0 1 0 0 1 (50) 2 0.22% male 0 0 0 0 1 0 0 1 (50) -1.32 actinic keratosis (cheilitis) female 0 0 0 0 0 0 0 0 (00.00) 1 0.11% male 0 0 0 0 0 1 0 1 (100) -0.66 lichenoid reaction female 0 0 0 0 0 0 0 0 (00.00) 1 0.11% male 0 1 0 0 0 0 0 1 (100) -0.66 total female 2 44 20 11 7 0 0 84(55.62) 151 (100) 16.68% male 2 45 11 4 2 3 0 67(44.37) table 5: distribution of candidiasis according to age and sex in 905* oral lesions candidiasis sex age (y) subtotal n (%) total n (%) % (905) lesions 10 19 2029 3039 4049 5059 6069 7079 denture stomatitis female 0 0 2 6 5 2 3 18 (78.26) 23 2.54% male 0 0 1 0 1 3 0 5 (21.73) -56.09 angular cheilitis female 0 4 0 0 0 0 0 4 (44.44) 9 0.99% male 1 0 0 2 0 2 0 5 (55.55) -21.95 median rhomboid glossitis female 0 0 0 0 2 0 0 2 (25) 8 0.88% male 0 2 1 2 0 1 0 6 (75) -19.51 thrush female 0 0 0 0 1 0 0 1 (100) 1 0.11% male 0 0 0 0 0 0 0 0(00.00) -2.43 total female 0 4 2 6 8 2 3 25 (60.97) 41 4.53% male 1 2 2 4 1 6 0 16 (39.02) -100 table 6: distribution of benign lesions according to age and sex in 905* oral lesions inflammatory (reactive) hyperplasia sex age subtotal n (%) total (%) % (905) lesions 10-19 20-29 30-39 40-49 50-59 60-69 70-79 fibro epithelial hyperplasia female 0 3 2 1 0 1 0 7 (58.33) 12 -(35.29) 1.32% male 0 3 0 0 1 0 1 5 (41.66) denture induced fibrous hyperplasia female 0 0 0 1 3 1 5 10 (90.90) 11 (-32.35) 1.21% male 0 0 0 1 0 0 0 1 (9.09) peripheral giant cell granuloma female 0 0 0 0 0 0 0 0 (00.00) 2 (-5.88) 0.22% male 1 0 0 0 0 1 0 2 (100) gingival hyperplasia female 0 0 0 0 0 0 0 0 (00.00) 3** (-8.82) 0.33% male 1 2 0 0 0 0 0 3 (100) mucoceles female 0 0 0 1 0 0 0 1 (33.33) 3 (8.82) 0.33% male 1 1 0 0 0 0 0 2 (66.66) radicular cyst female 0 1 0 0 0 0 0 1 (50) 2 (-5.88) 0.22% male 0 0 1 0 0 0 0 1 (50) port wine stain female 0 0 0 0 0 0 0 0 (00.00) 1 (-2.94) 0.11% male 0 0 0 1 0 0 0 1 (100) total female 0 4 2 3 3 2 5 19 (55.88) 34 (-100) 3.75% male 3 6 1 2 1 1 1 15 (44.11) **1case is hereditary gingival fibromatosis and 2 cases are drug induced j bagh college dentistry vol. 25(2), june 2013 clinicopathological oral diagnosis 105 discussion among 3144 patients, only 799 patients (25.41%) had oral lesions. females constituted 49.81% (n=398) and males 50.18 (n=401). the age range of the patients was between 10-79 years with a mean age of 33.75 years. tongue lesions were considered as fissure tongue (18.23%), black hairy tongue (6.51%), ankyloglossia (3.75%), geographic tongue (1.98%) and scalloped tongue (0.33%). the most common tongue lesion was fissured tongue, the number of patients with fissured tongue was 165, 76 patients (46.06%) were females and 89 patients (53.93%) were males. this is compatible with other studies done by mathew et al. (13) in southern india, and mojarrad and vaziri (14) in which fissured tongue was more common among males. the commonly affected age group (40.60%) was between 20-29 years, this is compatible with neville et al. (15) in which fissured tongue may be seen in children or adults, but the prevalence and severity appear to increase with age and disagrees with the study done by mathew et al. (13) in southern india in which 41-60 years of age were the most common affected age group. the number of patients with geographic tongue was 18, 11 patients (61.11%) were females and 7 patients (38.88%) were males. the most commonly affected age group was 2029 years, this is compatible with the study done by jainkittivong and langlais in which geographic tongue was more common among females and the highest incidence (39.4%) occurred in the 20-29 age groups (16). anatomic changes and developmental anomalies were considered as linea alba (16.68) followed by fordyce's granules (12.37%), torus mandibularis (0.66%), and torus palatinus (0.55%). we did not compare our results with other studies because there was no studies about the clinicopathological aspect of these lesions, as these lesions are almost always analyzed in a prevalence study either alone or with other lesions. the most common white lesion was cheek biting (12.15%) followed by frictional keratosis (2.875%) and oral lichen planus (0.88%). the number of patients with cheek biting was 110, 66 patients (60%) were females and 44 patients (40%) were males. the most commonly affected age group (64.54%) was between the ages of 2029 years; this is compatible with other studies done by neville et al. (15) and cebeci et al. (9) in which cheek biting was more common among females. the number of patients with frictional (traumatic) keratosis was 26, 12 patients (46.15%) were females and 14 patients (53.84%) were males. the most commonly affected age group (50%) was between the ages of 20-29 years, this is compatible with other studies done by mathew et al. (13) and cebeci et al. (9) in which frictional (traumatic) keratosis was more common among males and the most commonly affected age group was between 21-40 years. the number of patients with oral lichen planus was 8, 5 patients (62.5%) were females and 3 patients (37.5%) were males. the most commonly affected age group (37.5%) was between the ages of 20-29 years with mean age of 41.62, this is compatible with other studies that were done by pakfetrat et al. (17) in which lichen planus was more common among females. this study is compatible with other studies done by pakfetrat et al. (17) in which olp was more prevalent in third to fourth decades of life and disagrees with the finding of oliveira alves et al. (18) in which a predominance of olp was observed in the fifth, sixth and seventh decades of life. the majority of the oral lichen planus (50%) were seen in the buccal mucosa, followed by tongue (28.56%), anterior gingiva (7.14%), retromolar pad area (7.14%) and alveolar ridge (7.14%) in a descending order. this is in agreement with other studies done by pakfetrat et al. (17) and oliveira alves et al. (18), in which buccal mucosa was the site most affected, followed by the tongue and gingiva. the most common ulcerative lesion was ras (5.85%) followed by recurrent herpes simplex virus infection and traumatic ulcer (2.43%). the number of patients with recurrent aphthous stomatitis was 53, 29 patients (54.71%) were females and 24 patients (45.28%) were males. the most commonly affected age group (62.26%) was between the ages of 20-29 years, this is compatible with other studies in which recurrent aphthous ulcers were more common among females gaphor and hussien, (19). the majority of the minor recurrent aphthous ulcerations (33.87%) were seen in the lower lip, followed by the mucobuccal fold area (20.96), buccal mucosa (17.74%), lateral tongue (8.06%), upper lip (8.06%), tip of tongue (6.45%), and ventral tongue (4.83%) in a descending order. this is in agreement with gaphor and hussien, which stated that minor aphthous ulcers were found in nonkeratinized mobile mucosa of the oral cavity (19). the number of patients with denture stomatitis was 23, 18 patients (78.26%) were females and 5 patients (21.73%) were males, this is compatible with other studies done by baena-monroy et al. in which they confirm that stomatitis mainly affects women (20) . the most commonly affected age groups (26.08%, 26.08%) were between 40-49, and 50-59 years, they were also a little bit younger than the patients of other studies vitkov and lugstein (21) and baena-monroy et al.(20) in j bagh college dentistry vol. 25(2), june 2013 clinicopathological oral diagnosis 106 which they confirm that stomatitis affects mainly elderly. the most common benign lesion was fibroepithelial hyperplasia (1.32%) followed by denture induced fibrous hyperplasia (1.21%). the number of patients with fibroepithelial hyperplasia was 12, 7 patients (58.33%) were females and 5 patients (41.66%) were males. this is compatible with other studies done by awange et al. in which fibroepithelial hyperplasia was more common among females (22). the most commonly affected age group (50%) was between 20-29 years, this is compatible with another study done by nartey et al. in which focal febrous hyperplasia (fibroma) was occurring over a wide age range, with a peak incidence in the third decade(23). the majority of the fibroepithelial hyperplasis (50%) were seen in the buccal mucosa, followed by tongue (16.66%), lip (16.66%), gingiva 8.33% and alveolar ridge (8.33%) in a descending order. this is in agreement with other studies done by neville et al. in which the most common location for irritational fibroma was the buccal mucosa along the bite line (15). in our study the number of patients with denture induced fibrous hyperplasia was 11, 10 patients (90.90%) were females and 1 patient (9.09%) was male which agree with coelho et al. (24) and nevalainen et al. (25). in this study, the majority of the denture induced fibrous hyperplasia (58.82%) were seen in the lower jaw than the upper jaw (41.17%), ifh occurs at a higher rate in the maxilla xie et al., (26); coelho et al. (24) than in the mandible. this situation may be explained by the fact that the area of mucosa covered by a denture is greater in the maxilla than the mandible, so the pressure being inserted to the underlying mucosa is higher in the maxilla canger et al. (27). in this study, the anterior region of the jaws was more affected (76.47%) than the posterior regions (23.52%). the anterior regions of the jaws are more often affected by ifh than the posterior regions xie et al. (26). similar results were found in a study of these lesions in a population of turkey canger et al. considering that 77.5% of ifh were in the anterior region (27). as conclusion, routine examinations of oral cavities are valuable in identifying several oral lesions and this will help to establish early diagnosis and treatment and better prognosis. references 1. triantos dimitris. intra-oral findings and general health conditions among institutionalized and noninstitutionalized elderly in greece. j oral pathol med 2005; 34 (10): 577 – 582. 2. soames jv, southam ej. oral pathology. 4th ed. new york: oxford university press inc; 2005. 3. shulman jd, beach mm, rivera-hidalgo f .the prevalence of oral mucosal lesions in u.s. adults data from the third national health and nutrition examination survey, 1988-1994. j am dent assoc 2004; 135: 1279-86. 4. reichart pa . oral mucosal lesions in a representative cross-sectional study of aging germans. community dent oral epidemiol 2000; 28(5): 390-8. 5. jainkittivong a, aneksuk v, langlais rp. oral mucosal conditions in elderly dental patients. oral dis. 2002; 8(4): 218-23 6. jahanbani j, sandvik l, lyberg t, ahlfors e . evaluation of oral mucosal lesions in 598 referred iranian patients. the open dent j 2009; 3: 42-47. 7. reichart pa. oral mucosal lesions in a representative cross sectional study of aging germans. community dent oral epidemiol.2000; 28(5): 390-8. 8. bornstein mm, suter vg, stauffer e, buser d. the co2 laser in stomatology: part 2. schweiz monatsschr zahnmed 2003; 113(7): 766-85. 9. cebeci ari, gulsahi a, kamburoglu k, orhan bk, oztas b. prevalence and distribution of oral mucosal lesions in an adult turkish population. med oral patol oral cir bucal 2009; 14(6): e272-7. 10. campisi g, margiotta v . oral mucosal lesions and risk habits among men in an italian study population. j oral pathol med.2001; 30(1): 22-8. 11. martínez ai, garcía-pola mj . epidemiological study of oral mucosal pathology in patients of the oviedo school of stomatology. med oral 2002; 7(1): 4-16. 12. who oral health surveys, basic methods, criteria for the examination of the oral mucosa and soft tissues. 4th ed. england; 1997. p. 1-66. 13. mathew al, pai km, sholapurkar aa, vengal m. the prevalence of oral mucosal lesions in patients visiting a dental school in southern india. indian j dent res 2008; 19(2): 99-103. 14. mojarrad f, vaziri p bakianian . prevalence of tongue anomalies in hamadan, iran. iranian j publ health 2008; 37(2): 101-105. 15. neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology. 2nd ed. philadelphia: saunders; 2002. 16. jainkittivong a, langlais rp. geographic tongue: clinical characteristic of 188 cases. j contemp dent pract 2005; 6(1):123-35. 17. pakfetrat atessa, javadzadeh-bolouri abbas, basirshabestari samira, falaki farnaz . oral lichen planus: a retrospective study of 420 iranian patients. med oral patol oral cir bucal 2009; 14(7):e315-8. 18. oliveira alves mônica ghislaine, almeida janete dias, balducci ivan, cabral luiz antonio guimarães . oral lichen planus: a retrospective study of 110 brazilian patients. bmc res notes 2010; 3:157. 19. gaphor sh. m, hussien sh. a. clinical observation of recurrent aphthous stomatitis in sulaimania. j bagh coll dentistry 2009; 21(1): 74-79. 20. baena-monroy t, moreno-maldonado v, francomartinez f, aldapebarrios b, quindsَ g, sanchezvargas lo. candida albicans, staphylococcus aureus and streptococcus mutans colonization in patients wearing dental prosthesis. med oral patol oral cir bucal 2005; 10: e27-e39. 21. vitkov l, lugstein a. glycaemic disorders in denture stomatitis. j oral pathol med 1999; 28: 406-409. j bagh college dentistry vol. 25(2), june 2013 clinicopathological oral diagnosis 107 22. awange do, wakoli ka, onyango jf, chindia ml, dimba eo, guthua sw. reactive localized inflammatory hyperplasia of the oral mucosa. east afr med j 2009; 86(2): 79-82. 23. narty n, masadomi h, al-gilani m, al-mobeerik a . localized inflammatory hyperplasia of the oral cavity: clinico-pathological study of 164 cases. saudi dent j 1994; 6(3): 145-50. 24. coelho cmp, sousa tcs, dare amz . denturerelated oral mucosal lesions in a brazilian school of dentistry. j oral rehabil 2004; 31:135-139. 25. nevalainen mj, narhi to, ainamo a. oral mucosal lesions and oral hygiene habits in the home-living elderly. j oral rehabil 1997; 24:332-337. 26. xie q, ainamo a, tilvis r . association of residual ridge resorption with systemic factors in home-living elderly subjects. acta odontol scand 1997; 55:299305. 27. canger em, celenk p, kayipmaz s . denture-related hyperplasia: a clinical study of a turkish population group. braz dent j 2009; 20(3): 243-8. 17. deelan f.doc j bagh college dentistry vol. 27(4), december 2015 an assessment of oral and maxillofacial surgery and periodontics 107 an assessment of salivary leptin and resistin levels in type two diabetic patients with chronic periodontitis (a comparative study) deelan amanj sabir, b.d.s. (1) maha abdul-aziz ahmed, b.d.s., m.sc. (2) abstract background: type 2 diabetes mellitusand chronic periodontitis hold a close relationship that has been the focus of many researches. currently there is an appreciation to the role of adipose tissue-derived substances "the adipokines" in immune-inflammatory responses; also, there is an interest in using the simple non-invasive saliva in diagnosing and linking oral and general health problems. the current study aims to determine the periodontal health status in the chronic periodontitis patients with and without poorly or well controlled type 2 diabetes mellitus, measure the salivary levels of two adipokines "leptin and resistin", ph and flow rate and then correlate between these clinical periodontal, biochemical and physical parameters in each study and control groups. materials and methods: seventy five males were recruited for the study, with an age range of (35-50) years. the subjects were divided into four groups: two non-diabetic groups: one of them with healthy periodontium and systemically healthy (control, 15 subjects) and the other with chronic periodontitis (20 patients) and two type 2 diabetic groups: well controlled (20 patients) and poorly controlled (20 patients) both of them with chronic periodontitis.unstimulated whole salivary samples were collected from all of the participants; salivary flow rate and ph were measured and then biochemically analyzed for assessment of resistin and leptin levels.clinical periodontal parameters included: the plaque index, the gingival index, the bleeding on probing, the probing pocket depth and the clinical attachment level had been recorded for all subjects at four sites per tooth except for the third molars. results: the results of clinical periodontal examination revealed that the group of chronic periodontitis with poorly controlled type 2 diabetes mellitus had the worst periodontal health status. the biochemical analysis demonstrated that the lowest level of salivary leptin was foundin the chronic periodontitis with poorly controlled type 2 diabetes mellitus group. in addition, the highest level of salivary resistin was demonstrated in chronic periodontitis with well controlled type 2 diabetes mellitus group. when the salivary flow rate and ph were measured, it was found that they were decreased in the study groups as compared to the control group. a non-significant moderate negative correlation between salivary leptin with ph in the control group was found. while, salivary resistin demonstrated a high significant moderate positive correlation with the gingival index in the non-diabeticchronic periodontitis group and a non-significant moderate negative correlation with salivary flow ratein the control group. finally, the study found that the correlation between salivary leptin and resistin was non-significant weak negative in each of the study and control groups. conclusion: it can be concluded that poorly controlled type 2 diabetic patients have more periodontal tissue destruction and less salivary flow rate than well controlled type 2 diabetic patients and non-diabetic patients all of them with chronic periodontitis. salivary resistin and leptin hormones may be useful biochemical markers of periodontal tissue destruction and this will provide better opportunities in early diagnosis, monitoring and efficient management of periodontal diseases and t2dm. key words: t2dm, cp, resistin, leptin and saliva. (j bagh coll dentistry 2015; 27(4):107-114). introduction diabetes is a group of metabolic diseases in which hyperglycemia results from defects in insulin secretion and/or action. the most prevalent type is type 2 diabetes mellitus (t2dm). the chronic hyperglycemia of diabetes adversely affects different body organs, particularly the eyes, kidneys, heart, blood vessels and nerves (1). the periodontal disease (pd) is a chronic inflammatory process that affects the tooth supporting tissues and occurs as result of interaction between the periodontopathic bacteria and the host immune system. it can be broadly divided to gingivitis (which is a reversible form that isn't accompanied by attachment loss) and periodontitis (which is an irreversible form and results in attachment loss) (2). (1) master student. department of periodontics, college of dentistry, university of baghdad. (2) assistant professor, department of periodontics, college of dentistry, university of baghdad. the most common form of periodontitis is the chronic periodontitis (cp) that typically affects adults between 40 to 50 years old and is characterized by its slowly progressing nature, but at some point undergoes exacerbation(3). there is a close association between t2dm and pd that been well recognized in many clinical and epidemiological studies (46). resistin and leptin belong to the adipose tissue-derived adipokines which are molecules participate in the pathogenesis of both cp and t2dmvia their roles in immune-inflammatory responses, bone metabolism and insulin sensitivity (7,8). nowadays, there is a trend toward using the saliva as a diagnostic fluid for determination of systemic diseases because it is a non-invasive and cost-effective method (9) and this has motivated us to perform the current study which utilizes the salivary resistin and leptin levels for the purpose of determination of the effect of j bagh college dentistry vol. 27(4), december 2015 an assessment of oral and maxillofacial surgery and periodontics 108 glycemic control on the periodontal health status in patients with cp, since these two hormones are involved in the immune and inflammatory responses that comprise the basis of the crosssusceptibility between the cp and t2dm. materials and methods the human sample consists of 75 males with age range of (35-50) years. the collection of patients with t2dm started in erbil from family health care centers and then in baghdad, were recruited from specialized center for endocrinology and diabetes in baghdad /alrussafa, while the control and chronic periodontitis subjects were recruited from periodontics department, at the teaching hospital, in the college of dentistry, university of baghdad. the subjects were divided into four groups: a. cp with poorly controlled t2dm (cp+pt2dm): consisted of 20 males with cp and hba1c > 9%. b. cp with well controlled t2dm (cp+wt2dm): consisted of 20 males with cp and hba1c < 7%. c. systemically healthy with chronic periodontitis (cp): consisted of 20 males. cp in patients was defined as the presence of minimally four sites with ppd ≥ 4 mm and clinical attachment loss of (1-2) mm or greater(10). d. systemically healthy with healthy periodontium (control): consisted of 15 males apparently systemically healthy and with clinically healthy periodontium, this was defined by gingival index (gi) scores <0.5 (11) and without periodontal pockets or clinical attachment loss. this group represents a base line data for the levels of salivary leptin and resisitin. inclusion criteria include only males with t2dm (diabetic for 5 years) on oral hypoglycemic therapy only, at least 20 teeth present and body mass index within the normal range which is between 18.5-24.9 kg/m2 (12). while, the exclusion criteria included: females, t1dm and t2dm administering insulin, smoking and alcohol consumption, presence of systemic diseases other than t2dm, presence of nephropathy, retinopathy and diabetic foot, patients who've undergone periodontal treatment oradministrated medications (anti-inflammatory, anti-microbial,anti-depressants and antilipidemic) in the three months prior to the study. unstimulated whole salivary samples were collected from all of the groups at 9-12 a.m.,(13). salivary flow rate (fr) was calculated by dividing the volume of the collected sample by the collection time. then salivary ph was measured by using (dp universal test paper), then the samples were centrifuged at 4000 rpm for 15 min. and frozen at -20 ºc. clinical periodontal parameters examination was performed after collecting the salivary samples by using the michigan o periodontal probe on four surfaces (mesial, buccal/ labial, distal and lingual/palatal) of all teeth except the third molar. these included: 1. assessment of soft deposits by the plaqueindex system (pli) (14). 2. assessment of gingival inflammation by thegingival index system (gi) (11). 3. assessment of gingival bleeding on probing (bop) (15). 4. assessment of probing pocket depth (ppd). 5. assessment of clinical attachment level (cal). for the purpose of biochemical analysis of salivary leptin hormone we used demeditec leptinenzyme-linked immunosorbent assay (elisa) test kit (dee007) and used (dee050) demeditec resistin elisa kit of salivary resistin hormone. both hormones concentrations were determined by measuring the absorbance at 450 nm by the spectrophotometer. descriptive statistics in the form of median value and inferential statistics in the form of kruskal-wallis h test, mann-whitney u test and pearson correlation were used in this study. the levels are accepted as significant (s) at (0.05 p-value 0.01), highly significant (hs) at pvalue 0.01 and non-significant (ns) at p-value > 0.05. results the highest mean of age parameterwas found in cp+pt2dm (46.30) followed by cp+wt2dm (45.40), cp group (42.10) and the least mean was found in control group (37.53). clinical periodontal parameters analysis: the highest median values of the clinical periodontal parameters were recorded in cp+pt2dm, followed by cp+wt2dm then cp group except for bop and ppd; the score 1 bop was higher in cp than in cp+wt2dm and ppd was equal in these groups. the comparisons between all pairs of the study groups revealed highsignificant differences between cp+pt2dm with both cp+wt2dm andcp; while, non-significant between cp+wt2dm with cp regarding (pli,bop, ppd and cal). hence, at gi they were high significant differencesbetween cp with both j bagh college dentistry vol. 27(4), december 2015 an assessment of oral and maxillofacial surgery and periodontics 109 diabetic groups but non-significant betweendiabetic groups with each other (table-1). biochemical parameters analysis: the biochemical analysis (table-2) of the salivary resistin revealed that the highest concentration was in cp+wt2dm, followed by cp+pt2dm then cpand finallythe control. furthermore, salivary leptin revealed that the highest concentration was in the control group followed by cp and cp+wt2dm equally and lastly the cp+pt2dm demonstrated the least concentration. highly significant differencesin the median values of both leptin and resistin concentrations revealed among the study and control groups at p < 0.01. the results of the comparisons for all pairs of the study and control groups in (table-3) about both of leptin and resistin levels revealed: highly significant differences between control group and all of the study groups, non-significant differences between cp+pt2dm and cp+wt2dm; as well as, between cp+wt2dm with cp group. finally, the comparisons between cp+pt2dm with cp groups revealed a nonsignificant difference in leptin levels but the difference was significant in resistin levels. physical parameters analysis: the highest median value (table-2) of salivary fr was in control group, followed by cp then cp+wt2dm and lastly cp+pt2dm. the highest median value of salivary ph was found in the control group while it was equal in the rest of the study groups. the results revealed highly significant differences in the median values of both salivary ph and fr among the study and control groups at p < 0.01 as shown in table 2. when comparing the salivary physical parametersin all pairs of study and control groups, the results showed that the salivary fr hadsignificant differences between control with all of the study groups, but they were nonsignificant between cp with both diabetic groups as well as, between diabetic groups themselves.the intergroup comparisons of salivary ph revealed highly significant differences between control with both diabetic groups; in addition, cp+pt2dm with cp, while they were non-significant between cp with control and cp+wt2dm, as well as between diabetic groups. the results are shown in (table 3). correlations of salivary leptin and resistin hormones with clinical parameters and with each other: as can be seen in table 4, leptin hormone generally, demonstratednon-significant weak correlations with all of the clinical parameters at all groups except for a non-significant moderate negative correlation with ph in control group. while the correlations of resistin hormone with clinical parameters (table-5) revealed a high significant moderate positive correlation existed with gi in cp group and a nonsignificant moderate negative correlation with fr in control group. finally, non-significant weak negative correlations were found between leptin with resistin hormones in the saliva at each of the study and control groups (table-6). discussion the highest mean of age parameter was found in cp+pt2dm while the lowest mean was found in control group, this can be attributed to the fact that the incidence of cp and t2dm is greater in older ages (16). clinical periodontal parameters analysis: the altered salivary fr and ph in the diabetic patients as well as altered oral flora and increased viscosity of the saliva(17), moreover, the increased glucose level in the gingival crevicular fluid(gcf) and saliva all contribute to the higher accumulation of plaque and calculus in the diabetic patients(18). the dm causes and exacerbates the gingival inflammatory response to the bacterial plaque which means that there is an alteration in the response of periodontal tissue to local factors in diabetic patients. the inflammatory reactions are intensified during poor metabolic control, as the same amount of plaque causes more gingival bleeding in poorly controlled diabetic patients compared to the wellcontrolled ; hence, more plaque accumulation in cp+pt2dm leads to more gingival inflammation than cp+wt2dm group (5). moreover, the detrimental effects of advanced glycation end products and receptor for advanced glycation end products (ages-rages) interactions in the periodontium of diabetic patients that include: increase vascular permeability, impaired wound healing and vascular changes contribute to more periodontal destruction(19). the dm modifies periodontitis by dysregulating the immune and inflammatory responses in the periodontium, thus more cytokines are accumulated in the gingival tissues. also, dm causes diminished function of the neutrophils and hyperactivity of macrophages j bagh college dentistry vol. 27(4), december 2015 an assessment of oral and maxillofacial surgery and periodontics 110 table (1): median values of the clinical periodontal parameters and the intergroup comparisons between all pairs of the study groups periodontal parameters groups descriptive statistics cp+pt2dm cp+wt2dm cp+pt2dm cp cp+wt2dm cp median mannwhitney u test p-value sig. mannwhitney u test p-value sig. mannwhitney u test p-value sig. pli cp+pt2dm 1.41 102.5 0.008 hs 72.5 0.001 hs 149 0.167 ns cp+wt2dm 1.26 cp 1.24 control 0.196 gi cp+pt2dm 1.15 147.5 0.155 ns 70.5 0.000 hs 88 0.002 hs cp+wt2dm 1.08 cp 1 control 0.05 bop score 1 cp+pt2dm 62.20 74.5 0.001 hs 86.5 0.002 hs 199.5 0.989 ns cp+wt2dm 44.21 cp 44.78 ppd cp+pt2dm 6.19 84 0.002 hs 74 0.001 hs 186.5 0.715 ns cp+wt2dm 5.21 cp 5.21 cal cp+pt2dm 3.13 83.5 0.002 hs 65.5 0.000 hs 153 0.203 ns cp+wt2dm 2.45 cp 2.28 table (2): median values of salivary leptin, resistin, fr and ph and the significance of difference among the study and control groups parameters cp+pt2dm cp+wt2dm cp control kruskal-wallis h test median median median median x2 pvalue sig. leptin ng/ml 2.24 2.34 2.34 2.564 16.295 0.001 hs resistinng/ml 8.96 9.82 8.35 4.74 18.079 0.000 hs fr ml/min 0.33 0.36 0.39 0.41 13.411 0.004 hs ph 6 6 6 7 17.080 0.001 hs table (3): intergroup comparisons of the median values of salivary leptin, resistin, fr and ph between all pairs of the study and control groups parameters cp+pt2dm cp+wt2dm cp+pt2dm cp cp+pt2dm control cp+wt2dm cp cp+wt2dm control cp control mannwhitney u test pvalue sig. mannwhitney u test pvalue sig. mannwhitney u test pvalue sig. mannwhitney u test pvalue sig. mannwhitney u test pvalue sig. mannwhitney u test pvalue sig. leptin 189 0.753 ns 166.5 0.343 ns 42.5 0.000 hs 176.5 0.495 ns 50.5 0.001 hs 74.5 0.009 hs resistin 198 0.957 ns 118.5 0.027 s 39.5 0.000 hs 144 0.130 ns 53 0.001 hs 73 0.010 hs fr 138 0.071 ns 136 0.058 ns 59.5 0.002 hs 197 0.927 ns 89 0.028 s 86 0.019 s ph 138.5 0.090 ns 104.5 0.009 hs 41.5 0.000 hs 160 0.273 ns 69 0.006 hs 97 0.075 ns j bagh college dentistry vol. 27(4), december 2015 an assessment of oral and maxillofacial surgery and periodontics 111 table (4): correlations between the levels of leptin hormone with the clinical parameters at each study and control groups parameters statistical analysis cp+pt2dm cp+wt2dm cp control pli r -0.175 0.198 0.006 0.107 p 0.460 0.402 0.981 0.704 gi r 0.018 -0.067 -0.287 0.223 p 0.940 0.780 0.220 0.424 bop score 1 r -0.142 -0.295 0.237 x p 0.551 0.207 0.314 x ppd r -0.205 0.036 0.131 x p 0.387 0.880 0.582 x cal r 0.245 0.182 -0.190 x p 0.299 0.442 0.423 x fr r -0.065 0.253 -0.149 -0.077 p 0.787 0.281 0.532 0.786 ph r -0.132 -0.349 0.006 -0.421 p 0.578 0.132 0.981 0.118 table (5): correlations between the levels of resistin hormone with the clinical parameters at each study and control groups parameters statistical analysis cp+pt2dm cp+wt2dm cp control pli r -0.301 -0.168 0.292 -0.195 p 0.197 0.479 0.212 0.487 gi r -0.303 0.189 0.645 -0.345 p 0.195 0.424 0.002 0.208 bop score 1 r 0.138 -0.276 0.115 x p 0.563 0.239 0.629 x ppd r 0.068 0.037 -0.076 x p 0.774 0.876 0.750 x cal r 0.131 0.222 -0.235 x p 0.581 0.347 0.319 x fr r -0.014 -0.173 -0.073 -0.442 p 0.954 0.465 0.760 0.099 ph r 0.165 -0.293 -0.178 -0.071 p 0.487 0.210 0.454 0.801 table (6): correlation between salivary levels of (leptin with resistin) hormones at each study and control groups parameter statistical analysis cp+pt2dm cp+wt2dm cp control resistin r -0.006 -0.177 -0.330 -0.142 p 0.980 0.454 0.156 0.613 and monocytes which will result in further periodontal destruction (20), so diabetic patients have greater prevalence and extent of periodontal pockets (21). poorly controlled diabetics had threefold increase in risk of having periodontitis compared to non-diabetics; furthermore, are prone to more severe periodontitis (22) and increases the risk of progressive bone loss and attachment loss over time (23). biochemical parameters analysis: in the light of the present study, resistin (which serves as a proinflammatory mediator) is found in the saliva in both health and disease, but its concentration increases with presence of inflammation that is involved in both cp and t2dm, which assures it's involvement in the inflammatory process. human resistin is derived from the infiltrating immune cells (24). inflammatory cytokines as interleukin-1(il-1), il-6 and tumor necrosis factor-α (tnf-α) which are involved in pathogenesis of cp were found to affect the resistin expression in vitro (25). it was found that lipopolysaccharides (lps) of escherichia coli (e. coli) and leukotoxinof aggregatebacteractinomycetemcomitans a.a. j bagh college dentistry vol. 27(4), december 2015 an assessment of oral and maxillofacial surgery and periodontics 112 (which are both periodontal pathogens) increase the production of resistin (26). resistin binds to human leukocytes and induces the cytokines production by peripheral blood mononuclear cells(27). also, resistin suppressed the neutrophils chemotaxis and reduces the oxidative burst provoked by e.coli (28). moreover, a potential role for resistin in bone metabolism was suggestedby increased resistin levels that coincided with osteoclast differentiation (29). it was demonstrated that salivayresistin levels in t2dm patients were significantly higher than non-diabetic patients (30). also, it was found that resistin expression in the adipose tissue and its levels in the serum are increased in response to hyperinsulinemia and hyperglycemia (31). from the present study, it can be observed that the differences in leptin hormone levels between all pairs of the study groups were non-significant, however when comparing each one of the study groups with the control group, it was found that the differences were highly significant. these results come in agreement with (32,33), but, disagree with the result of thanakun et, al., (34) who demonstrated that salivary leptin level did not differ between healthy controls and patients with metabolic syndrome. leptin hormone has a role in pathogenesis of dm since it exerts a regulatory effect on food intake as well as on hyperinsulinemia and hyperglycemia (35). moreover, it has a role in pathogenesis of cp via its direct effect on innate immunity (organizes phagocytosis and cytokines production from macrophages, oxidative capacity of polymorphonuclear leukocytes and natural killer cells cytotoxicity) (36) and adaptive immunity (stimulates pro-inflammatory cytokines production by t and b lymphocytes which include: il-6, il-10, tnf-α (37). kim (38) found that leptin has the ability to enhance the tnf-α production that is induced by prevotellaintermedia lps; thus result in chronic lesion and osseous tissue destruction which are both involved in inflammatory pd. however, it was demonstrated that leptin levels in the saliva are low and inversely correlated with the progression of the periodontium from health to disease (32, 34). physical parameters analysis: the dm is associated with chronic complications such as neuropathies and deterioration of microcirculation which can lead to salivary glands hypofunction (39) and altered salivary fr and xerostomia (40) which will unfavorably influence the diluting and cleaning capacities of the saliva as well (41). hence, acidic ph can be attributed to the diminished salivary fr as in dm (42) or due to cp (43). correlations of salivary leptin and resistin hormones with clinical parameters and with each other: the current study revealed that salivary leptin had non-significant weak correlations with the clinical parameters except for the non-significant moderate negative correlation with ph in the control group.the leptin is produced by the salivary glands (44), however, its levels in the saliva are decreased as the periodontal disease progresses which might indicate that leptin is down regulated within the salivary glands themselves and gingival tissues in one way or another in accordance to the degree of the gingival inflammation (32), however, a study by sattari et, al., (24) disagree with the results of this study. karam (32) found that salivary leptin showed a significant negative correlation with the pli and gi in healthy controls, while in cp group no significant correlations with the clinical periodontal parameters. concerning resistin correlation, the results of this study disagree with karam (32) who found a significant positive correlation between resistin and both of pli and gi in control group, while no correlations were found between resistin and the clinical periodontal parameters in the cp group.another study (8) found that salivary resistin levels were significantly and positively correlated with gcf levels,in addition salivary resistin level was significantly and positively correlated to the percentages of bop sites, mean (ppd and cal) as well as periodontal inflamed surface area and suggested that the elevated levels of resistin in saliva reflect the intensity of local inflammation in the periodontium and not related to t2dm; also, suggested that the resistin was derived from immune cells that respond to periodontopathic microorganisms and then this resistin seeps from gcf into the oral fluid. no study that addresses the correlation between these two hormones in saliva was performed before.the possible explanation of the weak correlation is the limited human sample size.the correlation between leptin and resistin was found to be negative which coincides with the fact that, the increased inflammation in the study groups was associated with increased resistin concentration and decrcreased leptin concentration. j bagh college dentistry vol. 27(4), december 2015 an assessment of oral and maxillofacial surgery and periodontics 113 references 1. diabetes care. diagnosis and classification of diabetes mellitus. american diabetes association. 2014; 37(1): 14–80. 2. michael g newman, henry h takei, perry r klokkevold, fermin a carranza. carranza's clinical periodontology. 12th ed. st. louis: saunders elsvier; 2015. 3. lindhe j, niklans pl karring t. clinical periodontology and implant dentistry. 5th ed. wileyblackwell; 2008. 4. preshaw pm. diabetes and periodontal disease. international dental journal 2008; 58: 237-43. 5. abdul-wahab ga, ahmed ma. assessment of some salivary enzymes levels in type 2 diabetic patients with chronic periodontitis (clinical and biochemical study). j bagh college dentistry 2015; 27(1):138-43. 6. hadratie sf, al-juboury aah. regulation of hba1c of uncontrolled diabetic type ii obese and normal weight patients by oral hygiene performance. j bagh college dentistry 2013; 25(1): 102-107. 7. catalan v, gomez-ambrosi j, rodriguez a, salvador j, fruhbeck g. adipokines in the treatment of diabetes mellitus and obesity. expert opin pharmacother 2009; 10: 239-54. 8. al-shahwani rms. the role of resistin as a mediator of cross-susceptibility between periodontal disease and type 2 diabetes mellitus, thesis submitted in partial fulfilment of the requirements for the degree of doctor of philosophy, newcastle university, school of dental sciences & institute of cellular medicine, 2012 9. greabu m, battino m, mohora m, et al. saliva – a diagnostic window to the body, both in health and in disease. j medicine and life 2009; 2(2):124-32. 10. lang np, bartold pm, cullinam m et al. international classification workshop. consensus report: chronic periodontitis. annals periodontal 1999; 4: 53. 11. löe h. the gingival index, the plaque index and the retention index system. j periodontal 1967; 38(6): 610-6. 12. world 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overview. ann periodontol 2001; 6:91-6. 20. venza i, visalli m, cucinotta m, de grazia g, teti d, venza m . proinflammatory gene expression at chronic periodontitis and peri-implantitis sites in patients with or without type 2 diabetes. j periodontol 2010; 81:99-108. 21. mealey bl, oates tw. diabetes mellitus and periodontal diseases. j periodontol 2006; 77:1289-303. 22. santos vr, ribeiro fv, lima ja, napimoga mh, bastos mf, duarte pm. cytokine levels in sites of chronic periodontitis of poorly controlled and wellcontrolled type 2 diabetic subjects. j clin periodontol 2010; 37:1049-58. 23. taylor gw, burt ba, becker mp, genco rj, shlossman m, knowler wc, et al. non-insulin dependent diabetes mellitus and alveolar bone loss progression over 2 years. j periodontol 1998; 69:7683. 24. sattari m, noori bk, moozeh mb, et al. correlation between leptin and chronic periodontitis. j dental school 2012; 29(4): 282-8. 25. bokarewa m, nagaev i, dahlberg l, smith u, tarkowski a. resistin, an 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orig res 2008; 34(1):40-46. 43. baliga s, muglikar s, kale r. salivary ph: a diagnostic biomarker. j indian soc periodontol, 2013; 17:461-5. 44. randeva hs, karteris e, lewandowski kc, et al. circadian rhythmicity of salivary leptin in healthy subjects. mol genet metab 2003; 78: 229-35. hadeel f.doc j bagh college dentistry vol. 27(3), september 2015 comparison between oral and maxillofacial surgery and periodontics 89 comparison between powerful waterpik flosser with dental floss as an adjunct to tooth brushing hadeel m. akram, b.d.s., m.sc. (1) abstract background: removing dental plaque is important to maintain a good oral hygiene and prevent periodontal disease; this could not be accomplished by the use of toothbrush alone, it needs the help of interdental aids or intraoral irrigator devices. the aim of this study was to compare the effect of using waterpik flosser as adjunct to tooth brushing than using the dental floss with the brushing. materials and methods: a single blind, six weeks study included 45 subjects divided into three groups of 15 subjects at each group. group b (brushing) was instructed to use the toothbrush only, group bf (brushing & flossing) was instructed to use dental floss and tooth brushing while group bw (brushing and waterpik flosser) was instructed to use waterpik flosser in addition to the toothbrush. plaque index, gingival index and bleeding on probing were measured at the 1st visit, after 3 weeks (2nd visit) and finally after 6 weeks (3rd visit). results: the plaque index was significantly reduced in group bf and bw at the 3rd visit, while it showed no significant differences in group b. the mean percentage reduction of gingival index at the 3rd visit was higher in group bw than group b and group bf. using the chi-square test, bleeding on probing showed no significant difference in group b, while there was significant reduction in group bf and highly significant reduction (p<0.001) in group bw between the visits. conclusion: waterpik flosser was more effective in reducing dental plaque and bleeding than dental floss. key words: brushing, waterpik flosser, dental floss. (j bagh coll dentistry 2015; 27(3):89-92). introduction daily removal of dental plaque biofilm is important to maintain a healthy gingiva and prevent gingivitis and periodontitis, (1) because this biofilm contains the bacteria responsible for caries formation and the development of gingivitis and periodontitis (2). the most common device used for mechanical plaque control is the tooth brush. brushing the teeth will remove the supragingival plaque from tooth surfaces (3), but it will not clean the interdental areas or the subgingival areas, so using interdental aids such as the dental floss, tooth picks or interdental brush is important to clean these areas. recently, new devices have been developed and designed to aid brushing (4). one of these devices is the water flosser. a dental water flosser which is an electric oral irrigator device, that delivers pulsating water with controlled pressure to remove the interdental and subgingival plaque biofilm on tooth surfaces and reduce inflammation as a supplement to tooth brushing (5). pulsation and pressure are the two main physical features of water flossing action. a combination of these two actions will disrupt the bacterial activity and causing expulsion of subgingival bacteria, removing the loosely lodged debris and food particles, hence research has determined the appropriate levels of pressure that should be applied during usage which is about 50–90 psi (pounds of pressure per square inch). (1)assistant lecturer, department of periodontics, college of dentistry, university of baghdad. both healthy and inflamed tissues can comfortably handle this pressure without tissue damage (6,7). the daily use of oral irrigator devices has been shown to reduce bleeding, gingivitis dental plaque, dental calculus, probing pocket depth, count of periodontal pathogens, and host inflammatory mediators (8,9). the aim of this study was to compare the effect of using the waterpik flosser as adjunct to tooth brushing than using the dental floss with the brushing. materials and methods study design a single blind, sixweeks study included 45 adult subjects with an age range between 25 to 50 years old were recruited for this study without regard to sex. all subjects were systemically healthy, non smoker and had at least 20 evaluable teeth, not including the third molars, and not suffering from periodontitis or attachment loss, other exclusion criteria included pregnancy, lactation, using of contraceptive pills and the presence of orthodontic or prosthodontics appliances. the subjects had a history of at least one-time daily brushing and should be suitable for the use of dental floss as interdental aids. the subjects were divided into 3 groups (group b (brushing), group bf (brushing & flossing) and group bw (brushing and water flosser) each group included 15 subjects. all the subjects in the three groups received instructions about the modified bass technique of brushing and were instructed to brush twice daily for two minutes each time using a provided toothbrush with soft bristle. j bagh college dentistry vol. 27(3), september 2015 comparison between oral and maxillofacial surgery and periodontics 90 group b used a manual toothbrush only with no interdental aids or therapeutic mouth rinses. group bf used a manual toothbrush and unwaxed dental floss. the subjects in this group were instructed to floss once daily in the evening by wrapping the floss around the middle fingers and using the index fingers and thumb to guide the floss, contour it around the side, move the floss up and down the tooth and to introduce the floss subgingivally for 2mm. the third group (group bw) used a manual toothbrush and a waterpik dental water jet (figure 1). the subjects in group bw were relatives to ensure their continuous use of the waterpik flosser according to the given instructions. they were instructed to use the waterpik flosser once daily in the evening using a medium pressure and 500ml of warm water. the waterpik flosser is a power-driven device, which has a reservoir of water, pressure control, and delivers a pulsating stream of water directed at the gingival margin and interproximal areas. the water will strike the tooth at the gingival margin and then deflected subgingivally and interdentally. the subjects were instructed to use the classic jet tip and directed it at the gingival margin following a pattern around the whole mouth. figure 1: waterpik flosser periodontal assessment the periodontal assessment of clinical periodontal parameters included: plaque index (pli) (10), gingival index (gi) (11) and bleeding on probing (bop) were measured for all the teeth (excluding third molars) and four sites for each tooth were examined (buccal, lingual, mesial and distal). the means of the pli and gi were calculated by dividing the sum of the surfaces scores on the number of the surfaces. bop was measured by inserting a blunt periodontal probe to the bottom of the gingival sulcus and moving it gently along the tooth surface. if bleeding occurs within 30 seconds after probing, the site was given a score (1) and a score (0) for non bleeding sites (12). examinations were performed for all the subjects at first visit and after three weeks (2nd visit), while the third examination was after six weeks (3rd visit). subjects were asked to abstain from any oral hygiene for 12 hours before each study visit. data analyses were conducted by using microsoft excel 2010. results all the 45 subjects completed the study and no adverse events were reported. plaque index: means and standard deviations of pli were listed in table (1). in all the groups the means of pli were reduced at the third visit. using t-test, the results showed no significant differences of pli between 1st & 2nd (p=0.28), and 1st & 3rd (p=0.073) visits for group b. while there were highly significant differences (p<0.001) of pli between 1st & 2nd, 1st & 3rd visits in group bf and group bw (table 2). the mean percentage reduction in the pli at 2nd visit, for group b was 7.84% while for groups bf and bw were 27.63% and 73.09%, respectively. the mean percentage reductions in the pli at 3rd visit, for groups b, bf, and bw were 12.93% 35.36%, and 89.16%, respectively (table 3). gingival index: the mean of the gi at the first visit was 1.091, 1.08 and 1.22 and it was reduced at the 3rd visit to 1.0003, 0.799 and 0.436 for group b, group bf and group bw respectively (table 1). the t-test showed no significant difference (p=0.15) of gi between 1st & 2nd visits and significant difference (p=0.016) between 1st & 3rd visits in group b, while both group bf and bw showed highly significant differences (p<.0.001) of gi between the visits (table 2). the mean percentage reductions in the gi at 2nd visits were 4.62%, 17.41%, and 35.65%, while at the 3rd visits, were 8.31% 26.02%, and 64.26%, for groups b, bf, and bw respectively (table 3). bleeding on probing: the percentage of bleeding sites in the 1st visits, were 9.33%, 7.09%, and 19.16%, and they were reduced at the 3rd visits, to 7.44% 4.65%, and 1.16%, for groups b, bf, and bw respectively (table 4). using the chi-square test, the reduction in bop were of no significant difference (p=0.06) in j bagh college dentistry vol. 27(3), september 2015 comparison between oral and maxillofacial surgery and periodontics 91 group b, while there were significant reduction (p=0.003) in group bf and highly significant reduction (p<0.001) in group bw (table 5). table 1: descriptive statistics of the plaque index and gingival index for each group at different visits groups mean & sd of pli mean & sd of gi 1st visit 2nd visit 3rd visit 1st visit 2nd visit 3rd visit group b 1.047+ 0.219 0.965+ 0.193 0.912+ 0.178 1.091+ 0.096 1.041+ 0.091 1.0003+ 0.098 group bf 1.035+ 0.213 0.749+ 0.096 0.669+ 0.096 1.08+ 0.138 0.892+ 0.061 0.799+ 0.089 group bw 1.375+0.33 0.37 + 0.208 0.149+ 0.041 1.22 + 0.144 0.785 +0.193 0.436 + 0.192 table 2: comparison between visits at each group for pli and gi groups pli gi 1st & 2nd visit 1st and 3rd visit 1st & 2nd visit 1st and 3rd visit group b 0.28 ns 0.073 ns 0.15 ns 0.016 s group bf <0.001 hs <0.001 hs <0.001 hs <0.001 hs group bw <0.001 hs <0.001 hs <0.001 hs <0.001 hs table 3: mean percent reduction of the pli and gi between visits at each group groups pli gi 1st & 2nd visit 1st and 3rd visit 1st & 2nd visit 1st and 3rd visit group b 7.84% 12.93% 4.62% 8.31% group bf 27.63% 35.36% 17.41% 26.02% group bw 73.09% 89.16% 35.65% 64.26% table 4: percentage of bop (score 1) for each group at different visits groups 1st visit 2nd visit 3rd visit group b 9.33% 7.62% 7.44% group bf 7.09% 5.3% 4.65% group bw 19.16% 4.38% 1.16% table 5: chi square for bop (score 1) between visits at each group groups 1st & 2nd visit p value 1st & 3rd visit p-value group b 3.081 0.08 ns 3.814 0.06 ns group bf 6.21 0.01 s 8.827 0.003 s group bw 172.9 <0.001 hs 291.9 <0.001 hs discussion tooth brushing alone is not enough to maintain a good oral hygiene; it needs to be supplemented by a device that can clean the subgingival and interdental areas. in this study we compared the use of dental floss with waterpik flosser. the plaque index was significantly reduced in group bf and bw, but the mean percent reduction showed a superior effect of the waterpik flosser to the dental floss. this result agrees with researchers who found that using of water flosser alone or as an adjunct to tooth brushing, showed superior or equivalent reductions in plaque accumulations (13,14). based on these results, it appears that tooth brushing, with the use of waterpik flosser once daily with plain water, is more effective than brushing and flossing, which agrees with shibley et al, who found that waterpik is an effective alternative to dental floss (15). previous studies linked the superiority of waterpik flosser to both the ability of irrigation to reduce subgingival bacteria and to modulate the host response. using the electron microscope, the investigators demonstrated that oral irrigation reduced periodontal pathogens, and reduced the fibrin-like network which houses the plaque. cobb, et al. found that non-irrigated areas had plaque in fibrin-like mesh, while no or little fibrin mesh present in irrigated sites (16). another study found that the water flosser with the classic jet tip removed 99.9 percent of plaque biofilm (17). socransky and haffajee noted that hydrodynamics affect the rate at which nutrients are transported to the plaque and affect the physical shear stress and these will impact the growth and structure of the plaque (18). regarding the gingival inflammation and bleeding areas, the waterpik flooser was more effective than brushing, brushing and flossing in j bagh college dentistry vol. 27(3), september 2015 comparison between oral and maxillofacial surgery and periodontics 92 improving the gingival health and reducing gingival bleeding. different hypotheses have been put forward to explain this effect. one of the hypotheses is that supragingival irrigation alters the population of key pathogens, reducing gingival inflammation (19). another hypothesis is that a change in the host response may be produced by the oral irrigation. cutler, et al demonstrated this change by showing that daily irrigation with water reduced the gingival crevicular fluid measures of pro-inflammatory mediators interleukin 13 and prostaglandin pge2. they linked the reduction of bleeding sites to the reduction of interleukins. they noted that only the addition of irrigation produced this host modulatory change (20). so the results of this research indicated that oral irrigation when combined with tooth brushing is an effective alternative to traditional dental floss for reducing the plaque, bleeding and gingival inflammation. references 1. löe h, theilade e, jensen sb. experimental gingivitis in man. j periodontol 1965; 36:177-87. 2. gorur a, lyle dm, schaudinn c, costerton jw. biofilm removal with a dental water jet. compendium of continuing education in dentistry 2009; 30:1-6. 3. clayton nc. current concepts in tooth brushing and interdental cleaning. periodontol 2000 2008; 48:10-22. 4. sharma nc, qaqish jg, lyle dm, collins f, schuller r. comparison of two power interdental cleaning devices on the reduction of gingivitis. j clin dent 2012; 2 3: 22–6. 5. barnes cm, russell cm, reinhardt ra, payne jb, lyle dm. comparison of irrigation to floss as an adjunct to tooth brushing: effect on bleeding, gingivitis, and supragingival plaque. j clin dentistry 2005; 16:71-7. 6. bhaskar sn, cutright de, gross a, et al. water jet devices in dental practice. j periodontol 1971; 42(10): 658-64. 7. selting wj, bhaskar sn, mueller rp. water jet direction and periodontal pocket debridement. j periodontol 1972; 43(9): 569-72. 8. cutler cw, stanford tw, cederberg a, boardman tj, ross c: clinical benefits of oral irrigation for periodontitis are related to reduction of pro inflammatory cytokine levels and plaque. j clin periodontol 2000; 27: 134-43. 9. newman mg, flemmig tf, nachnani s, rodrigues a, calsin g, lee y-s, de camargo p, doherty fm, bakdash mb: irrigation with 0.06% chlorhexidine in naturally occurring gingivitis. ii. 6 months microbiological observations. j periodontol 1990; 61: 427-33. 10. silness j, loe h. periodontal disease in pregnancy ii, correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22:121-35. (ivsl) 11. loe h, silness j. periodontal disease in pregnancy i. prevelance and severity. acta odontol scand 1963; 21:533-51. (ivsl) 12. newbrun e. indices to measure gingival bleeding. journal of periodontology 1996; 67(6):555-61. 13. barnes cm, russell cm, reinhardt ra, et al. comparison of irrigation to floss as an adjunct to tooth brushing: effect on bleeding, gingivitis, and supragingival plaque. j clin dent 2005; 16(3): 71-7. 14. rosema nam, hennequin-hoenderdos nl, berchier ce, et al. the effect of different interdental cleaning devices on gingival bleeding. j int acad periodontol 2011; 13(1): 2-10. 15. shibley o, ciancio sg, shostad s, mather ml, boardman t. clinical evaluation of an automatic flossing device vs. manual flossing. j clin dent 2001; 12(3): 63-6. 16. cobb cm, rodgers rl, killoy wj: ultrastructural examination of human periodontal pockets following the use of an oral irrigation device in vivo. j periodontol 1988; 59:155-63. 17. gorur a, lyle dm, schaudinn c, costerton jw. biofilm removal with a dental water jet. compend contin educ dent 2009; 30(1): 1-6 18. socransky ss, haffajee ad: dental biofilms: difficult therapeutic targets. periodontol 2000; 28:12-55. 19. flemmig tf, epp b, funkenhauser z, et al. adjunctive supragingival irrigation with acetylsalicylic acid in periodontal supportive therapy. j clin periodontol 1995; 22: 427-33. 20. chaves es, kornman ks, manwell ma, jones aa, newbold da, wood rc. mechanism of irrigation effects on gingivitis. j periodontol 1994; 65:1016102. الخالصة یحتاج فإنھ وحده، أسنان فرشاة استخدام طریق عن یتحقق أن یمكن ال ھذا .اللثة أمراض ومنع لفمل جیدة نظافة على للحفاظ مھمة األسنان لوحة إزالة :خلفیةال كمساعد waterpik flosser خدام جھازاست لمقارنة الدراسة ھذه من الھدف وكان .الفم داخل الري أجھزة أو األسنان بین مساعدات التنظیف من الى مساعدة .مع الفرشاة األسنان تنظیف خیط استخدام من لفرشاة االسنان b المجموعة أوعز الى وقد .مجموعة كل شخصا في 15 من مجموعات ثالث إلى مقسمین شخص 45 وتضمنت. اسابیع 6استمرت الدراسة :واألسالیب المواد الفرشاة( bw مجموعة بینما والفرشاة األسنان تنظیف خیط لھا باستخدام وأوعز )والخیط تفریش( bf مجموعة ط،فق األسنان فرشاة باستخدام )تفریش( ونزیف اللثة مؤشر الصفیحة الجرثومیة، تم قیاس مؤشر .األسنان فرشاة إلى باإلضافة waterpik flosser فاوعز لھم باستخدام) وجھاز ري ما بین االسنان .أسابیع 6 بعد وأخیرا أسابیع 3 وبعد ،1 الزیارة في اللثة b مجموعة في كبیرة اختالفات أي تظھر لم أنھ حین في الثالثة، الزیارة في bwو bf في مجموعة كبیر بشكل الصفیحة الجرثومیة مؤشر تخفیض تم :النتائج في كبیر اختالف أي یظھر لم مؤشر نزف اللثة . bf و المجموعة b المجموعة من bw مجموعة في أعلى الثالثة الزیارة في اللثة مؤشر نسبة تخفیض وكان. .الزیارات بین bw مجموعة في (p <0.001) للغایة كبیر وانخفاض bf مجموعة في كبیر انخفاض ھناك كان حین في ،b المجموعة األسنان تنظیف خیط من ونزیف اللثة في تقلیل مؤشر الصفیحة الجرثومیة فعالیة أكثر waterpik flooser كان: االستنتاج 23. aseel f.doc j bagh college dentistry vol. 27(4), december 2015 prevalence of pedodontics, orthodontics and preventive dentistry 143 prevalence of pacifier sucking habit and its effect on occlusion in children aged 1-5 years in baghdad city aseel haidar al-assadi, b.d.s, m.sc. (1) zainab a.a. al-dahan, b.d.s, m.sc. (2) abstract background: non-nutritive sucking habits are common in infants and toddlers. one of the most common nonnutritive sucking habits is pacifier; its prevalence varies from one population to another. this study was conducted to determine the prevalence of pacifier sucking habit among children aged 1-5 years old in baghdad city and to assess its effect on the occlusion of primary dentition concerning posterior crossbite. materials and methods: the study was carried out among 1222 children aged 1-5 years old, from which 50 children with continues pacifier sucking habit were chosen to be the study group, compared to 50 children without any sucking habit (control group) matching the study group in age and gender. children were examined clinically to record the presence of posterior crossbite. results: the prevalence of pacifier sucking habit was 24.54%; it is tend to decrease with age. posterior crossbite was found in18% of the pacifier sucking group and all of these cases were unilateral, however, none of the control group had posterior crossbite. in this study girls had higher tendency to suck pacifier and to have posterior ccrossbite than boys. conclusions: prevalence of pacifier sucking habit was more among girls, it can cause posterior crossbite which is mainly unilateral and more among girls than boys. key words: pacifier sucking habit, posterior crossbite. (j bagh coll dentistry 2015; 27(4):143-146). introduction all infants use their mouth to explore their world, some continue this and enjoy non nutritive sucking on a pacifier which is an object that is shaped for babies, mouth; it is a nursing device with an imperforated nipple used by many children to provide a sense of security and pleasure (1). under the age of 4 years, 45% of children have sucking habits and most of them stop the habit at (3-6) years and very few of them continue beyond the age of 6 years at that time they must be treated otherwise they may have malocclusion and speaking problems (2,3). advantages for both the child and his parents from the use of pacifier may include soothing the child after a fright, helping him to sleep longer at night, decreasing thumb sucking likelihood and help him cope with separation (4). conversely, pacifiers have been associated with a number of negative health effects including its adverse relation to breast feeding (5,6), otitis media (7), candidal infection and thrush (8-10), in addition, their prolonged use can be considered as a risk factor that may increase the development of tooth decay (9,11) as well as the development of posterior cross bite which is one of the most frequent malocclusion associated with the prolonged use (12-14). prevalence rates of pacifier use may vary according to the age of children, however, its use generally decreases with the increase of age (4). (1) lecturer, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. about 68% of the american infants aged 6 weeks and under used a pacifier (5). in uk the prevalence rate of children used pacifier at the age 15 months was 36% (15), while niemela (7) found the prevalence rate among the finnish children aged 2 months to 7 years which was 26%, however, their use has long been controversial (16). in iraq no previous study was done concerning the use of pacifier in children, so this study was conducted on group of iraqi children to know the prevalence of this habit with special attention to its effects on posterior cross bite. materials and methods after identifying the kindergarten and nursery schools and getting approval of the ministries of work and social affairs, education and health to carry out this study, a contact with school authorities was made to explain the purpose of the study.1222 children aged 1-5 years were selected from fifteen kindergarten and nursery schools in each side of baghdad city, 600 children were chosen from al-karkh area and 622 children were chosen from alrussafa area. permission was obtained from the parents for including their children in the study and questionnaires were designed to get information from them including general health and the sucking habits of their children. continuous pacifier sucking habit was found in 98 children, from which 48 children had been lost because of the discontinuing of the child from the school, thus 50 children formed the study group which was compared to 50 children (control group) matching in age and gender the j bagh college dentistry vol. 27(4), december 2015 prevalence of pedodontics, orthodontics and preventive dentistry 144 study group from the same school and without any sucking habit. a clinical examination was conducted in the classroom; each child was examined while seated on school chair underartificial light source. occlusion was examinedwhile the mandible in centric occlusion. a posterior crossbite was recorded if the buccal cusps of themaxillary teeth occluded lingual to the buccal cusps of the corresponding mandibular teeth (17) (fig.1). results three hundred children from 1222 children were found to have pacifier sucking habit (continuous habit and discontinuous habit), which represents 24.54% from the total sample (table 1). there was significant difference between boys and girls regarding pacifier sucking habit (z=2.95). table (2) shows the distribution of children with pacifier sucking habit according to the continuity of the habit, girls were more than boys in both continuous habit and discontinuous habit group. distribution of pacifier sucking children in the study group and non pacifier sucking group (the control group) according to age and gender is shown in table (3). at (1-2) years, 42% of the study sample had pacifier sucking habit which represent the highest percentage, however, the lowest percentage was 12% among those belonged to the (4-5) years group. in this study, (table 4) demonstrates the distribution of children according to the presence of posterior crossbite. the results show that 9 children in the pacifier sucking group, which represent 18% from the total sample, had unilateral posterior crossbite and 7(14%) of them were girls, while in non pacifier sucking group none of them had posterior crossbite (neither unilateral nor bilateral). discussion the sample was selected randomly to be representative of 1-5 years in baghdad city. prevalence of pacifier sucking habit in this study was 24.54%, table (1), which is lower than that found by farsi and salama (18) among saudi children (37.90%), but near that reported by niemelaetal (7) among finnish children (26%). these differences suggest that non-nutritive sucking habits are influenced by raising practices of the child which in turn differ from one population to another (18). results of the present study found that prevalence of sucking habits was more among girls and it is statically significant (table 2) which is similar to the results of other studies (19,20) and it can be explained as that tendency to develop this habit is greater in girls as they have more emotional problems than boys (19,20). prevalence of pacifier sucking habit in the present study, seems to decreased with age (table 3), which is in agreement with many other studies (4,718),this may be due to that as the child grows older, his need to suck diminished and he will likely give up the pacifier on his own way, while others will be motivated to give up the habit by their parents. several studies reported a significantly greater prevalence of posterior crossbite among pacifier sucking children compared with non pacifier sucking children (13, 14, 18,21-24) and this is in agreement with the results of the present study. posterior crossbite was 18% among pacifier sucking group (table 4), and this was in accordance with that found by larsson (23) and stecksenetal (24) which were 16% and 16-18% respectively. for many children the teat of the pacifier has become a natural part of the oral environment causing changes in the surrounding tissues, the tongue has to take a lower position in the anterior part of the mouth and in this way the palatal support of the upper primary canines and the first molars against the pressure of the check is reduced. in addition to that, the tongue also will exert increased lateral pressure at the lower canines and the first molar. the lack of palatal support from the tongue will result in narrow upper arch, while the pressure of the tongue will widen the lower arch, so these changes in equilibrium act to create a transverse disharmony in the canine region, which will increase the risk of posterior crossbite development (27). a pressure against the teeth has to exist for at least 6 hours to cause tooth movement so that differences in hours per day, rather than sucking intensity, could probably explain the development of posterior crossbite in some children more frequently than other children with the same habit (15). fig. 1: four years old child with unilateral posterior crossbite. j bagh college dentistry vol. 27(4), december 2015 prevalence of pedodontics, orthodontics and preventive dentistry 145 the presence of crossbite in pacifier sucking group was higher in girls than in boys (table 4), which is in agreement with other studies (14,21,25), suggesting that among girls, early eruption of teeth and establishment of occlusion may explain this finding. all the cases of posterior crossbite in this study are manifested unilaterally, which is in agreement with other studies (14,25) suggesting that posterior crossbite in the primary dentition are generally functional. table 1: prevalence of pacifier sucking habit *significant difference, z=2.95 table 2: distribution of children with pacifier sucking in relation to the continuity of the habit at the time of examination table 3: distribution of children in the study group and in the control group by age and gender table 4: distribution of children according to the presence of unilateral posterior crossbite among pacifier and non pacifier sucking children age group gender no. crossbite among pacifier sucking crossbite among non-pacifier sucking no. % no. % 1-2 boys 10 0 0 0 0 girls 11 3 27.27 0 0 both 21 3 14.28 0 0 2-3 boys 8 1 12.50 0 0 girls 7 2 28.57 0 0 both 15 3 20.00 0 0 3-4 boys 4 0 0 0 0 girls 4 1 25 0 0 both 8 1 12.50 0 0 4-5 boys 2 1 50 0 0 girls 4 1 25 0 0 both 6 2 33.33 0 0 all ages boys 24 2 4 0 0 girls 26 7 14 0 0 both 50 9 18 0 0 presence of pacifier sucking habit total (1222) boys (600) girls (622) no. % no. % no % no sucking habit 922 75.45 472 51.19 450 48.80 sucking pacifier 300 24.54 128 42.66* 172 57.33* presence of pacifier sucking habit continues no. (%) discontinuous no. (%) total boys 46 (46.94) 82 (40.59) 128 girls 52 (53.6) 120 (59.40) 172 total 98 (32.66) 202 (67.33) 300 age (years) pacifier sucking non pacifier sucking boys girls both boys girls both 1-2 10 (20%) 11 (22%) 21 (42%) 10 (20%) 11 (22%) 21 (42%) 2-3 8 (16%) 7 (14%) 15 (30%) 8 (16%) 7 (14%) 15 (30%) 3-4 4 (8%) 4 (8%) 8 (16%) 4 (8%) 4 (8%) 8 (16%) 4-5 2 (4%) 4 (8%) 6 (12%) 2 (4%) 4 (8%) 6 (12%) all ages 24 (48%) 26 (52%) 50 (100%) 24 (48%) 26 (52%) 50 (100%) j bagh college dentistry vol. 27(4), december 2015 prevalence of pedodontics, orthodontics and preventive dentistry 146 references 1. bear pn, pester m. the thumb, the pacifier, the erupting tooth and a beautiful smile. j pedodont 1987; 11:113-8. 2. ravan jj. the prevalence of dummy and finger sucking habits in copenhagen children until the age of 3 years. community dent oral epidemiol 1974; 2: 316–22. 3. mcdonald re, avery dr. dentistry for child and adolescent. 6th ed. st. louis: mosby year book; 1994. p. 485-6. 4. hanafin s, griffiths p. does pacifier use cause ear infections in young children? british journal of community nursing 2002; 7(4): 266–11. 5. howard cr, howard fm, lanphear b. the effect of early pacifier use in breast feeding duration. pediatrics 1999; 103: 33. 6. victra cg, tomasi e, olinoto mta, barros fc. use of pacifiers is associated with decreased breast feeding duration. pediatrics 1995; 95(4): 497–9. 7. niemelä m, uhari m, mottonen m. a pacifier increases the risk of recurrent acute otitis media in children in day care centers. pediatrics 1995; 96: 884 8. 8. sio jo, minwalla fk, george rh, booth iw. oral candida: is dummy carriage the culprit? arch dis child 1987; 4: 406-8. 9. ollila p, niemela m, uhari m, larmas m. risk factors for colonization of salivary lactobacilli and candida in children. acta odontol scand 1997; 55(1): 9 – 13. 10. niemela m, pihakar o, pokka t, uhari m. pacifier as a risk factor for acute otitis media. a randomized controlled trial of parental counseling. pediatrics 2000; 106: 483–8. 11. martinez sanchez l, diaz gonzalez e, garcia tornel florensa s, gaspa mj. pacifier use risk and benefits. an esp pediatr 2000; 53(6): 580-5. 12. larsson e. sucking, chewing and feeding habits and the development of cross bite: a longitudinal study of girls from birth to 3 years of age. angle orthod 2001; 71(2): 116-9. 13. warren j, bishara se, steinbock kl, yonezu t, nowak aj. effects of oral habits’ duration on dental characteristics in the primary dentition. j am dent assoc 2001; 132(12):1685–93. 14. katz cr, rosemblatt a, gondium pp. non-nutritive sucking habits in brazilian children: effect on deciduous dentition and relationship with facial morphology. am j orthod dentofac orthop 2004; 126: 53-7. 15. north sk, feming p, golding j. sociodemographic association with digit and pacifier sucking at 15 months of age and possible associations with infant infection. early hum dev 2000; 60(2):137–48. 16. orcutt b. are there drawbacks to the use of pacifiers? washington nurse 1997; 27(5): 14. 17. björk a, krebs aa, solow b. a method for epidemiological registration of malocclusion. acta odontol scand 1964; 22(1): 27–41. 18. farsi nm, salama fs. sucking habits in saudi children: prevalence, contributing factors and effects on the primary dentition. pediatr dent 1997; 19(1): 28–33. 19. ogaard b, larsson e, lindsten r. the effect of sucking habits, cohort, sex, inter-canine arch widths, and breast or bottle feeding on posterior cross bite in norwegian and swedish 3 years old children. am j orthod dentofac orthop 1994; 106: 161–6. 20. adair sm, milan m, lorenzo i, russell. effects of current and former pacifier use on the dentition of 24 59 month old children. pediatric dentistry 1995; 17(7): 437-44. 21. larsson e. prevalence of cross bite among children with prolonged dummy and finger sucking habit. swed dent j 1983; 7: 115-9. 22. steckson, blicks c, holm ak. dental caries, tooth trauma, malocclusion, fluoride usage, tooth brushing and dietary habits in 4 years old swedish children: changes between 1967 and 1992. int j pediatr dent 1995; 5(3): 143–8. 23. larsson e. artificial sucking habits etiology, prevalence effect on occlusion. int j orafacial myol 1994; 20: 10–21. 24. myers dr, barenie jt, bell ra, williamson eh. condylar position in children with functional posterior crossbite: before and after crossbite correction. pediatric dentistry 1980; 2: 190-4 25. kennard ma. dental implications of digit and pacifier sucking and ways to stop the habit. topics pediatrics 2001; 19(1): 8-11. j bagh college dentistry vol. 31(3), september 2019 behcet’s disease 24 clinical assessment and cytomorphometric analysis of buccal mucosal cells in behçet’s disease patients dalya mohammed b.d.s., msc (1) layla sabri yas b.d.s., msc (oral pathology) (2) abstract background: behçet’s disease (bd) is a disorder of systemic inflammatory condition. its important features are represented by recurrent oral, genital ulcerations and eye lesions. aims. the purpose of the current study was to evaluate and compare cytological changes using morphometric analysis of the exfoliated buccal mucosal cells in behçet’s disease patients and healthy controls, and to evaluate the clinical characteristics of behçet’s disease. methods. twenty five behçet’s disease patients have been compared to 25 healthy volunteers as a control group. papanicolaou stain was used for staining the smears taken from buccal epithelial cells to be analyzed cytomorphometrically. the image analysis software has been used to evaluate cytoplasmic, nuclear areas and the nuclear/cytoplasmic ratio (n/c). results. the cytoplasmic and nuclear area of buccal cells of behçet’s disease cases were significantly smaller than those of healthy volunteers. however, the n/c ratio remained the same when compared between both groups. all patients had recurrent oral ulcer and none of the patient had cardiac and pulmonary symptoms. conclusion. cytomorphometric analysis and exfoliative cytology techniques have the ability to detect the alterations in buccal epithelial cells caused by behçet’s disease. key words. behçet’s disease, cytomorphometric analysis, exfoliative cytology. (received 2/1/2018; accepted 11/2/2018) introductions behçet’s disease (bd) is a systemic disease of inflammatory condition, whose causes are still vague. the clinical features of bd include aphthous stomatitis, genital aphthosis , uveitis, cutaneous lesions, arthritis, all types of vessels, central nervous system (cns) involvement, genitourinary, gastrointestinal, pulmonary, and renal involvement(1) . the most commonlypresented features of the disease are oral and genital lesions (2). aphthous stomatitis appears initially in about 70% of bd patients (3). the disease may start with one, if not more, of the above-mentioned symptoms whereas it takes years for other symptoms to turn up gradually (1). regardless of the eyes, its course has been characterized by re-current episodes limiting by itself of inflammation resulting in remarkably disabled cases (4). the disease can be seen all over the world, recording the highest in asia, the middle east, and the mediterranean region. the average age of starting point with bd is on the third decade of patient's life taking in consideration that the ratio of male to female is variable according to ethnicity (4). the range of male-to-female bd cases is "1:13:1") (5). the dilemma of the disease is noticed in the early years of its course, and in many cases takes years to appear, most of mortality rates of bd had been accounted for vascular and neurological involvements and can seldom appear for the first time as it takes time to turn up (6). the etiology of bd had been the result of both of environmental and genetic factors in most of the complicated diseases (7). a variety of diagnostic classifications and criteria have been suggested during the years (8). as there are no pathognomonic clinical or laboratory findings for bd, it must be diagnosed upon clinical grounds according to the international criteria for behcets disease (icbd), table 1 table 1: international study group criteria for the diagnosis of clinical manifestation point (3). oral aphthosis 2 genital aphthosis 2 ocular manifestations 2 skin manifestations 1 pathergy phenomenon 1 vascular manifestations 1 cyto-morphometric characteristics would be highly altered in the cells of buccal mucosa in case of chronic diseases associated with inflammation (9). exfoliative cytology is a technique characterized by being conservative not causing any invasion on tissues in addition to the possibility of the specimens taken to be determined in qualitative (1) master student, oral medicine, department of oral diagnosis, college of dentistry/ university of baghdad, iraq. (2) assistant professor, department of oral pathology dentistry, college of dentistry, university of baghdad. j bagh college dentistry vol. 31(3), september 2019 behcet’s disease 25 and quantitative manners (10) .quantitative characteristics such as cytoplasmic area (ca), nuclear area (na), and the nuclear to cytoplasmic ratio (n/c) have been found to be noticeable during the process of diagnosis of oral cavity lesions (11). the measurement of those morphometric features (nuclear, cytoplasmic areas and nuclear /cytoplasmic ratio) can be made manually with the help of ocular grids, or even objectively using a digital image analysis that can trace microscopic images to be measured reproducibly and objectively (12). there are many factors affecting the cell cytomorphology which is already collected from the buccal mucosa. systemic illness such as diabetes type 1 & 2, alcohol intake, and all types of anemia can be regarded as some of such factors (13) ,not forgetting the role of infectionrelated diseases (14) . the effects of behçet’s disease on buccal mucosal cells have been documented on some previous studies (15-16). quantitative exfoliative cytology has been used in this study so that the effect of behçet’s disease can be assessed in the buccal mucosa of cases in terms of estimating nuclear area (na), the cytoplasmic area (ca), and nuclear cytoplasmic ratio (n/c) to be compared with those of buccal mucosa of control group. material and methods the "case control" study was performed on two groups. the "study group" consisted of 25 bd patientss whose diagnosis was provided at the dermatology out-patient clinic in baghdad teaching hospital in medical city. the "control group" was composed of 25 healthy counterparts who got a health examination periodically. the study was done in accordance with the "local ethics committee for human research" after obtaining a written consent from all the participants. criteria of selecting patients a questionnaire had been completed for each subject for collecting data regarding their past medical history, diabetes mellitus, radiotherapy, smoking habits, alcohol consumption, and drug addiction, in order not to be included in this study. the process of sampling. all the samples of the "study subjects" have been collected over a period of 4 months after the diagnosis being confirmed according to icbd. in order to remove debris, the patient was asked to rinse with tap water. a piece of gauze was usually used for having a dry oral mucosa. the samples were collected from the buccal mucosa using a disposable pap smear brush. the freshlyobtained smears were streaked on labeled-glass slides and then the fixation would be in 95% ethyl alcohol. papanicolaou was used as a staining technique for the examination of cytomorphometric. the examination of cytomorphometric. it should be stated that nuclear area (na), cytoplasmic area (ca), ratio of nuclear area to cytoplasmic area (n/c) were included in the study parameters examined. the digital photographs, taken from the slides by means of light microscope with amounted digital camera (0.3m pixel vce-pw1), were used to perform cytological analysis. na and ca were measured on digital images using an image analysis software called "motic images plus 3.0(x86)" surrounding the nuclear and cytoplasmic cell boundaries (fig. 1). figure 1: the encirclement of boundaries of the cytoplasm and the nucleus of then suprabasal cells case on digital images (x20) j bagh college dentistry vol. 31(3), september 2019 behcet’s disease 26 statistical analysis in this study, the statistical analysis has been accomplished by spss version 23 software in addition to microsoft excel. the "semimov kolmogorov" test was used to examine the distribution of current variables whether they are normal or not. the measurement of central tendency was done with a median and more accurately the inter-quarter range. furthermore, the non-parametric "mann whitney" test was used to show the difference in the significance between both, the study and control groups. results in the present study, the age of bd patients ranged from 2556 years with a mean of 38 years, and 28.1 years for "control subjects" (𝑝=0.001). also, the gender distribution was nearly comparable in both groups with statistically significant differences (p= 0.001). male gender was more predominant than the female in both groups, and the ratio of male/female in bd cases=1.7:1 while it was 2.1:1 in healthy subjects as shown in table 2. the clinical symptom found in bd patients with the highest frequency was ocular involvement (80%) while the lowest frequency was neurological symptoms (4%). in addition, all bd cases had oral ulcers but none of them were recorded to have cardiac or pulmonary symptoms as shown in table 3. using the digital manner to analyze all the cells collected from healthy controls and bd cases is shown in table 4 which shows that the median of ca concerning bd cases is smaller (4980.7 um2) than that of healthy subjects(11530.7 um2 ). similarly, the nuclear area of behçet’s disease cases was 157.6 um2 compared to 388.5 um2 of that of healthy volunteers. however, the ratio of both groups showed nearly comparable results. discussion the major goal of the study was to determine and compare between the quantitative assessments of cytomorphometrical parameters of buccal mucosal cells of bd patients with healthy controls. the mean age in the current study of bd patients was 38 years, and this findings is in line with other iraqi studies (17, 18) . in addition, there was another study reporting the same mean age (19) . it was found in present study that the male gender was more predominant than that of female in bd cases and the ratio of male/female was 1.7:1. a similar predominance in gender and nearly comparable male/female ratio 2.9:1 to the current study was recorded (17) . nevertheless, the study done by zouboulis, 1999 found that the male and female in bd cases were frequently equal(20) . the reason behind those contradictory findings that the gender ratio was different according to geographical area (21). it has been found that in the current study, all cases with bd had recurrent aphthous stomatitis. the clinical symptoms in a decreasing order of frequency are ocular involvement with 80%, genital ulcerations with 60%, skin and articular lesions 40%, and 36% respectively, and scarcely neurological symptoms. none of bd cases had pulmonary or cardiac symptoms. with regard to clinical frequency, nearly similar findings were found on some studies (3, 20). but those studies slightly differed from other findings recorded on italian bd cases and on egyptian bd cases (22, 23). however, both of them revealed the same oral and genital frequency but the ocular and cutaneous lesions seldom occurred. the difference in study groups ethnically is the cause for varied bd clinical frequencies in addition to the probability of the severity of the disease, and the size of samples. in the present study, it was found that the cytomorphometrical variables such as cytoplasmic area (ca) and nuclear area( na) of oral epithelial cells of bd cases reduced significantly when compared with those of "control group" ,but the ratio was still comparable in both groups . the present findings have confirmed the findings reported by “erol aktunc et al." in 2016 who showed comparable results to present study (15). however, another study done by “kara et al.". revealed comparable results with regard to the reduction of cytoplasmic volume and nuclear volume. the ratio also reduced ,not still constant like what happened in present study, and the relative differences in outcomes may be related to using smaller sample size or different quantitative cytomorphometric parameters such as cytoplasmic volume (cv) and nuclear volume (nv) applying a specific formula on variables taken from digital images of light microscope (two dimensions) (16) . bd cases, unlike healthy volunteers, have elevating oxidative stress which is regarded as a biomarker for bd causing changes in j bagh college dentistry vol. 31(3), september 2019 behcet’s disease 27 cytomophometric characteristics in bd patients (24-25) . this study determined the cytomorphometrical analysis quantitatively of oral epithelial cells parameters in behçet’s disease cases to be compared with normal population. in conclusion the quantitative characteristics of cytomorphometry were affected and altered by behçet’s disease as a main factor for this alteration ,and these alterations are detectable by cytomorphometric analysis through exfoliative cytology. the cytomorphometric view of mucosal cells in bd patients presented in this study will contribute to the understanding of the effects of bd on the oral mucosa. references 1. arayssi t, hamdan a . new insights into the pathogenesis and therapy of behcets disease. curr opin pharmacol 2004; 4: 183-188. 2. alpsoy e, zouboulis c, ehrlich 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"turk j med sci january 2016; 46 (1): 145-51. 17. sharquie ke, al-araji a, hatem a. oral pathergy test in behcet disease. br j dermatol 2002; 146(1):168-9. 18. al-rawi zs, nada ah. prevalance of behcets disease among iraqis. adv exp med biol 2003; 528: 37-41. 19. yazici h, fresko i, yarddkul s. behcet syndrome: disease manifestations management, and advances in treatment. nat clin prect rheumatol 2007; 3: 148-55. 20. zouboulis cc. "epidemiology of adamantiades behcets disease" ann med interne 1999; 150 (6): 488-98. 21. krause i, yankerich a, fraser a, rosner i, meder r, zisman d, boulman n, rozenbaum m, weinberger a. "prevalence and clinical aspects of behcet disease in nourth of israel." clin rheumatol 2007; 26(4): 555-60. . 22. pipitone n, boiad l, olivieri i, cantini f, salvi f, malatesta r, corte r, triolo g, ferrante a, filippini d, paolazzi g, sarzi-puttini p, restuccia g, salvarani c. "clinical manifestation of behcet disease in 137 italian patient: results of multicenter study copyright", clin exp rheumatol 2004, 22 (supp). 1.36: s46-s51. 23. el-najjar ar, abo el-soud am, amar ha , al sayed m. "clinical characterstic and disease activity of behcets disease patient in zagazig egypt. " egypt romatol 2015, 37(4): 191-196. 24. bozkurt m, y¨uksel h, em s, oktayoglu p, yildiz m, akdeniz d, nas k. “serum prolidase enzyme activity and oxidative status in patients with j bagh college dentistry vol. 31(3), september 2019 behcet’s disease 28 behcet’s disease. ”redox report 2014; (19)2: 59– 64. 25. buldanlioglu s, turkmen s, ayabakan hb, yenice n, vardar m, dogan s, mercan e. “nitric oxide, lipid peroxidation and antioxidant defence system in patients with active or inactive behcet’s disease.” bjd 2005; (153) 3: 526–530. table 2: age and gender distribution control group bd group age range 18-45 25-56 mean 28.1 38 se 1.5 1.9 gender female 8 9 male 17 16 sum 25 25 p value <0.001 table 3: clinical manifestation of behçet’s disease cases clinical manifestation sum =25 n % % gentile ulcers 15 60 ocular lesions 20 80 articulal symptoms 2 36 skin lesions 10 40 neurological symptoms 1 4 gastrointestinal symptoms 4 16 oral ulcers 100% no cardiac symptoms no pulmonary symptoms table 4: cytomorphometrical analysis of behçet’s disease case group and control group control group bd group cytoplasmic area p=<0.001 range 9417.9-14775 3440-5924.7 median 11530.7 4980.7 mean rank 87.7 15.6 nuclear area p=<0.001 range 259.5-452.8 121-197.5 median 388.5 157.6 mean rank 88 42.8 n/c ratio p=<0.92 ns range 0.024-0.04 0.0240.049 median 0.032 0.033 mean rank 72.2 72.8 الخالصة فمويه وتناسليه متكررة وافات العين . مرض بهجت هو اضطراب ذو حالة التهابية جهازية .مميزاته الهامة تقرحاتالخلفية. الغرض من الدراسه الحاليه لتقييم ومقارنه التغيرات الخلويه باستخدام التحليل الخلوي لميزات الخاليا للخاليا الطالئيه المبطنه للخد االهداف. ولتقييم الخواص السريريه لمرضى بهجت. .قشره لمرضى بهجتالم . صبغة بابانيكوال استخدمت لصبغ المسحة متطوع اصحاء 25له مرض بهجت تمت مقارنتها مع احخمس وعشرون المواد وطرق العمل. لخلويه. برنامج التحليل الصوري يستخدم لتقييم الماخوذة من الخاليا الطالءيه المبطنه للخد. حتى يتم تحليلها بطريقة القياس الكمي للمميزات ا النووية الى السايتوبالزمية. يه والنوويه باالضافه الى النسبهالمساحه السايتوبالزم السايتوبالزم والنواة للخاليا المبطنه لخد حاالت مرض بهجت كانت اصغر بشكل ملحوظ عن هوءالءالمتطوعين االصحاء ومع ذلك النتائج. لديهم تقرحات فمويه متكررة وكذلك وال احد لديه وجميع المرضىكال المجموعتين. عند مقارنه السايتوبالزم بقيت نفسها, \نسبة النواة اعراض قلبيه او رئويه. تقنيات "تقشير الخاليا" و"تحليل القياس الكمي للميزات الخلويه" لها القابليه لكشف التغيرات, حدثت بسبب مرض بهجت االستنتاجات. نفسه,التي تحدث في الخاليا الطالئية المبطنة للفم. j bagh college dentistry vol. 26(1), march 2014 fracture resistance of restorative dentistry 7 fracture resistance of endodontically treated premolars with extensive mod cavities restored with different composite restorations (an in vitro study) aws h. atiyah, b.d.s. (1) luma m. baban, b.d.s., msc. (2) abstract background: this in vitro study evaluated the fracture resistance of weakened endodontically treated premolars with class ii mod cavities restored with different composite restorations (low-shrinkage filtek p90, nanohybrid filtek z250 xt and sdr bulk fill). the type and mode of fracture were also assessed for all the experimental groups. materials and method: fifty human adult maxillary premolar teeth were selected for this study. standardized extensive class ii mod cavities with endodontic treatment were prepared for all teeth, except those that were saved as intact control. the teeth were divided into five groups of ten teeth each (n=10): (group 1) intact control group, (group 2) unrestored teeth with endodontic treatment, (group 3) restored with (filtek z250 xt), (group 4) restored with sdr bulk-fill flowable composite and (group 5) restored with filtek p90 composite. all specimens were subjected to compressive axial loading until fracture in a universal testing machine. the data were statistically analyzed using one-way anova test and lsd test. macroscopic fracture type were observed and classified into favorable and unfavorable. specimens in group 3, 4 and 5 were examined by stereomicroscope at a magnification of 20× to evaluate the mode of failure into adhesive, cohesive or mixed. results: the mean fracture load was (1.123 kn) for group 1, (0.545 kn) for group 2, (0.687 kn) for group 3, (0.799 kn) for group 4 and (0.672 kn) for group 5. using one way anova test a highly significant difference (p < 0.01) were found among all groups. the use of bulk-fill flowable composite improved the fracture resistance significantly in comparison to silorane and non-significantly to filtek z250 xt. filtek z250 xt showed better improvement in fracture resistance but with no significant differences in comparison to filtek p90 composite restorations. the type of failure was unfavorable for all the restored groups. conclusion:all experimental composite restorations showed significant improvement in the resistance to cuspal fracture in comparison to unrestored one. however, under the conditions of this study, direct composite restorations should be considered as a valid interim restoration for weakened endodontically treated teeth before cuspal coverage can be provided. key words: fracture resistance, endodontically treated teeth, filtek z250 xt, sdr. (j bagh coll dentistry 2014; 26(1):715). introduction esthetic dentistry continues to evolve through innovation in bonding systems, restorative materials, and conservative preparation designs. increased use of composite resin materials for the restoration of the posterior dentition has drawn attention to technological advances in this field. a stable and durable bond between dental materials and tooth substrates is important from both a mechanical and esthetic perspective (1). such materials not only seal the margin, but several studies have also shown that the use of adhesive materials can reduce the weakening effect of preparation designs (2,3). tooth fracture has been described as a major problem in dentistry, and is the third most common cause of tooth loss after dental caries and periodontal disease.(4)root-filled teeth are at increased risk of fracture; caries and excessive removal of dentine during root canal treatment, rather than low moisture content and increased brittleness reduce tooth strength (5). loss of axial dentine walls, which is common in teeth requiring root filling, greatly weakens teeth (6). (1)master student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. adhesive dentistry has considerable advantages in the treatment of weakened tooth structure (7). the possibility of establishing adequate adhesion between tooth structure and restorations through adhesive materials may eliminate the need for extending cavity preparations to cover cuspal areas to prevent future tooth fracture (8,9). the choice of materials selected for intracoronal restoration of endodontically treated teeth plays an important role in tooth longevity. recently, sdr restorative material designed to be used as a base in class i and class ii restorations. it has handling characteristics typical of flowable composite, but can be placed in 4 mm increments with minimal polymerization stress. it is designed to be overlaid with methacrylate based universal posterior composite replacing missing occluso-facial enamel (10). further, silorane containing resin was recently introduced as an alternative lowshrinkage material. the subsequent polymerization shrinkage of these silorane-based composites has been reported to be significantly less than that of conventional rbc materials (11,12). in addition, methacrylate-based filtek z250 xt was recently introduced as a nanohybrid universal restorative composite with high filler j bagh college dentistry vol. 26(1), march 2014 fracture resistance of restorative dentistry 8 loading and improved mechanical properties and clinical performance (13). so this study was conducted to evaluate the ability of these new restorative composite materials to restore the strength of weakened endodontically treated premolars. materils and methods teeth selection fifty sound upper first premolar teeth with single root extracted for orthodontic purposes were used in this study. teeth were stored in 0.1 vol% thymol solution for 48 h (14). then in distilled water at room temperature (15,16). teeth storage lasted for a maximum of 3 months before samples were chosen for the study (17-19). teeth of comparable size and shape were selected by crown dimensions after measuring the buccolingual and mesiodistal widths in millimeters (20,21). then the teeth were assigned into five groups (n = 10). once each tooth size was determined the blw means were calculated for each group. the mean blw of each group was different by no more than 5% from the other groups (22-25). radiographs were taken in the mesio-distal dimensions. teeth were determined with two canals were selected for the study (26). teeth mounting to simulate the periodontal ligament, root surfaces were marked 2 mm below the cementoenamel junction cej and covered with a 0.6 mm thick foil (adapta foil, bego, germany) (27). each tooth was embedded in a block of self-cured acrylic resin (vertex, switzerland) in plastic cylinders (2.5cm×2.5cm). the teeth were embedded along their long axes using a surveyor. after the first signs of polymerization, teeth were carefully removed manually from the resin blocks (28). the acrylic covered the roots to within 2 mm of the cej, to approximate the support of alveolar bone in a healthy tooth (6,29). in order to simulate periodontal ligament, the adapta (foil) were removed from the root surface. a light body addition silicone impression material (aquasil lv utra, dentsply) was injected into the acrylic resin blocks in the site that was previously occupied by the tooth root and adapta foil, and the teeth were reinserted into the resin cylinders. a standardized silicone layer that simulated periodontal ligament was thus created taking the thickness of the foil (27). sample grouping the teeth were randomly divided into five groups (10 teeth in each group) according to the type of the restorative material that was used: group 1: sound control group. group 2: a class ii mesio-occluso-distal (mod) cavity was prepared with extensive endodontic access cavity involving the removal of the axial dentin. endodontic treatment was completed and the mod cavity left unrestored. group 3: a class ii mod cavity and endodontic treatment were prepared as in group 2 and restored with resin based composite (filtek z250 xt) (3m espe) using horizontal incremental layering technique. group 4: a class ii mod cavity and endodontic treatment were prepared as in group 2and restored with sdr (dentsply, detrey) as a flowable base up to 2 mm below the cavity margin and covered with filtek z250xt composite. group 5: a class ii mod cavity and endodontic treatment were prepared as in group 2 and restored with silorane-based low shrinkage dental composite (filtek p90) (3m espe) using horizontal incremental layering technique. cavity preparation all of the teeth, except for group 1 which served as intact control, received mod cavity preparation by the aid of a modified dental surveyor with no proximal steps and flat floor (30). the dimensions of the cavity preparations were such that remaining tooth structure was weakened. the bucco-lingual width of the occlusal isthmus and the proximal boxes was one half of the intercuspal width. cavity floor was prepared (1 mm) coronal to the cej and the total depth of the cavity was (5-6 mm) measured from the cavosurface margin of the palatal cusp. the cavo-surface margins were prepared at 90. consistency in cavity preparation was ensured by parallel preparation of the facial and palatal walls of the cavity (6). endoontic treatment endodontic access cavity was prepared, any access cavity wider than the width of the cavity (1/2 the intercuspal distance) was discarded.the teeth were held in moist gauze to prevent dehydration (31). root canals were instrumented initially using stainless steel k-files #10 and 15, followed by rotary ni-ti instruments (protaper, dentsplymaillefer) using crown-down technique. for standardization purposes, all canals were instrumented up to size f1(32,33). then the canals were filled by matching size protaper gutta-percha points using resin-based sealer (adseal, meta biomed). a resin based sealer was used to avoid the detrimental effect of eugenol-based sealers on j bagh college dentistry vol. 26(1), march 2014 fracture resistance of restorative dentistry 9 polymerization of composites (34). chemical cured glass-ionomer restorative material (riva self cure, sdi, austria) was used to seal the access cavity up to the level of the pulpal floor (35, 36). restorative procedure group 3 (filtek z250 xt) in this group, teeth were restored with nanohybrid methacrylate-based filtek z250 xt resin composite. a self-etch adhesive (adper easy bond self etch adhesive, 3m espe) was used to bond the restorative material to the cavity walls. the entire cavity was restored incrementally with horizontal placement technique. each increment was light cured by led curing device for 20 seconds according to the manufacturer′s instructions. group 4 (bulk-fill sdr) in this group, teeth were restored with a combination of a flowable base of bulk-fill sdr (dentsply-detrey) and filtek z250 xt resin composite. a self-etch adhesive (adper easy bond) was used to bond the restorative material to the cavity walls. the sdr restorative material was placed in the cavity up to 4mm and light cured according to the manufacturer instructions for 20 seconds by led curing device (lite q, monitex). as the cavity was filled with the bulkfill flowable base, the restoration was completed by replacing the remaining part of the cavity (1-2 mm) with one increment of filtek z250 xt and with one exposure. group 5 (filtek p90) in this group, teeth were restored with low shrinkage, silorane-based, posterior restorative composite (filtek p90, 3m espe, usa). silorane system adhesive (p90 system adhesive, 3m espe ag, germany) was used to bond the restoration to tooth structure. the adhesive system (p90 system adhesive) was applied according to the manufacturer’s instruction. then, the restoration was built up using horizontal incremental technique with low shrinkage, silorane-based, posterior restorative composite (filtek p90, 3m espe). each increment was no more than 2 mm. each increment was light-cured for 40 seconds using a led curing device according to the manufacturer instructions. after finalizing samples restoration, all the specimens were finished with diamond finishing burs and polished with cups and points using composite polishing paste (sdi, austria). all the specimens were stored after preparation and restoration in an incubator at 37 cº for one week, at 100 % relative humidity in deionizedwater before testing. placing specimens in water for one week is enough for composite to reach maximum stage of equilibrium of water sorption (37). mechanical testing all specimens were subjected to compressive axial loading until fracture in a computer controlled universal testing machine (wdw 2006, china). the crosshead speed was 0.5 mm/minute. a steel bar (8 mm in diameter) was placed at the center of the occlusalsurface and applied in parallel to the long axis of the tooth and to the slopes of the cusps (rather than the restoration).(14)all samples were loaded until fracture while maximum breaking loads were recorded in kilo newton (kn) by a computer connected to the loading machine. assessment of fracture type and mode macroscopic fracture patterns were observed after ink perfusion of each sample for 5 min. photographs were taken using a digital camera to determine type of fracture (29). further the type of failure was also determined and categorized as favorable and unfavorable fractures. unfavorable fracture was denoted if the fracture line was below the cej extending to the radicular portion. on the other hand, favorable fracture was denoted if the fracture line above the cej (32). the mode of failure was assessed into adhesive mode in which the failure occur at tooth\restoration interface, cohesive mode in which the failure occur within the restoration and mixed mode of failure in which the failure was both adhesive and cohesive. the mode of failure was evaluated under a stereomicroscope at a magnification of 20× (6). results fracture resistance values of all experimental groups the mean values, standard deviation (sd) and the percentage of increase and decrease in strength are presented for each group in (table1). in this study, intact sound teeth (group 1) presented the highest mean value (1.1235 kn), whereas prepared but unrestored teeth with endodontic treatment (group 2) showed the least fracture strength (0.5454 kn). table 1: mean values, standard deviation (sd) and percentage of reduction and increase in strength for each group group mean sd percentage of reduction in strength percentage of increase in strength group 1 1.123 .217 100 group 2 0.545 .087 51.45 group 3 0.687 .132 38.79 61.21 group 4 0.799 .128 28.88 71.12 group 5 0.672 .042 40.13 59.87 j bagh college dentistry vol. 26(1), march 2014 fracture resistance of restorative dentistry 10 the results of this study showed that the percentage of reduction in strength for the prepared unrestored teeth group was the highest (51.45%) among the other experimental groups. on the other hand, regarding restored groups, the percentage of increase in strength was the highest for teeth restored with sdr (group 4) (71.12%) in comparison with teeth restored with filtek z250 xt (group 3) (61.21%) and those restored with filtek p90 (group 5) (59.87%).anova test revealed that there was a statistically highly significant difference among all groups (p < 0.01), (table 2). therefore, least significant difference (lsd) test was used to evaluate the significance of difference between groups at a level of significance of (0.05). table 2: anova test sum of squares df mean square f-test pvalue between groups 1.924 4 .481 26.532 .000 within groups .816 45 .018 total 2.740 49 lsd test showed that there were statistically highly significant differences (p < 0.01) between the unprepared and all prepared teeth, either restored or unrestored. additionally, there were significant differences in fracture resistance between the prepared, unrestored teeth group (group 2) and all the restored teeth groups (p < 0.05). on the other hand, no significant difference in fracture strength was noted when comparing teeth restored with filtek z250 xt (group 3) to those restored with sdr (group 4) and filtek p90 (group 5) (p > 0.05). however, a significant difference was existed between teeth restored with sdr (group 4) and those restored with filtek p90 (group 5) (table 3). table 3: lsd test (i) factor std. error p-value sig. group 1 (control) .0602 .000 hs .0602 .000 hs .0602 .000 hs .0602 .000 hs group 2 (unrestored teeth) .0602 .023 s .0602 .000 hs .0602 .040 s group 3 (filtek z250 xt) .0602 .071 ns .0602 .804 ns group 4 (sdr) .0602 .041 s fracture type and mode the results of this study showed that intact sound teeth (group 1) had 8 samples with favorable fracture type and 2 samples with unfavorable type. whereas other groups like group 3, group 4 and group 5 had 9 samples presented unfavorable fracture type and 1 sample with favorable fracture. in addition, all 10 samples of group 2 had unfavorable fracture type (table 4). table 4: type of fracture in the study group fracture type total favorable unfavorable group 1 8 (80%) 2 (20%) 10 group 2 0 10 (100%) 10 group 3 1 (10%) 9 (90%) 10 group 4 1 (10%) 9 (90%) 10 group 5 1 (10%) 9 (90%) 10 fracture mode as presented in table (5), teeth restored with filtekz250 xt (group 3) and those with sdr (group 4) exhibited 9 sampleswith adhesive mode of failure and only one with cohesive failure. however, those restored with filtek p90 (group 5) presented 1 samplewith adhesive failure, 8 samples with mixed type of failure and 1 sample with cohesive type of failure. table 5: mode of fracture in the study groups group fracture mode total adhesive cohesive mixed group 3 9 (90%) 1 (10%) 10 group 4 9 (90%) 1 (10%) 10 group 5 1 (10%) 1 (10%) 8 (80%) 10 discussion in this in vitro study the fracture resistance and fracture pattern of endodontically treated premolars with weakened class ii mod cavities restored with different composite restorations have been evaluated. maxillary first premolars were chosen for this study because the cuspal inclines render them more susceptible to force that may promote cusp fracture (26). mesio-occlusal distal (mod) cavities were prepared in this study to simulate a situation that is often found clinically and has been extensively reproduced in other clinical studies. the general effect of mod cavity preparations is the creation of long cusps, thus there is a need for a restoration that not only replaces the tooth structure, but also increases thefracture resistance of residual tooth and promotes effective marginal sealing (38). j bagh college dentistry vol. 26(1), march 2014 fracture resistance of restorative dentistry 11 each specimen was subjected to compressive axial loading until fracture using a universal testing machine. in this study, the applied force speed was 0.5 mm/min. it was stated that lower speeds are accompanied by greater plastic deformation and, thus, higher fracture resistance measurements will be recorded (39). the choice of load direction (parallel to the long axis of the tooth) was also designed to simulate physiological function and to obtain a degree of non-axial loading through existing occlusal contact variations (29). in which during function the occlusion generates non-axial forces resolved into their vectors along the cuspal side. so the load was applied along the long axes to distribute stresses more evenly between the residual dental tissues and the restorative material simulating a physiologic occlusion (40). fracture resistance among all experimental groups intact teeth (group 1) presented the highest mean fracture load (1.1235 kn). a statistically high significant difference with other experimental groups was existed. this may be due to the presence of the palatal and buccal cusps with intact mesial and distal marginal ridges which form a continuous circle of dental structure, reinforcing the tooth (41, 42). on the other hand, prepared unrestored teeth with endodontic treatment (group 2) presented the least mean fracture resistance value (0.545 kn) and the highest percent of reduction in strength (51.45%) with significant difference when compared with the other groups. this may be due to the type and quality of the remaining tooth structure, especially the cusps and marginal ridges which form a circle of dentin and enamel, which has an influence on fracture resistance. due to endodontic treatment with mod cavity preparations, the strength of the tooth was considerably reduced; therefore, when forces are applied they act as a wedge between the buccal and lingual cusps in non-restored teeth; thus, decreasing the mean fracture resistance values and promoting more catastrophic types of fractures (43). in this study, it is clearly seen that all composite resin restored teeth displayed improved fracture strength than the prepared but unrestored teeth group with endodontic treatment which presented (0.5454 kn) mean value. these findings may be due to the ability of adhesive composite restorations to transmit and distribute functional stresses through restorative material-tooth interface due to mechanical interlocking of resin with peritubular/intertubular dentin and hybrid layer formation, with the potential to reinforce the weakened tooth structure.(42-44)teeth restored with filtek z250 xt (group 3) showed (0.6876 kn) mean fracture load and (61.21%) percent of increase in strength with a significant increase in fracture strength when compared with group 2. these findings may be attributed tothe high filler loading of filtek z250 xt (81.8 wt.%, 67.8 vol.%). besides, filtek z250 xt has silica/zirconia clusters “nanoclusters” with average filler size 0.1-10 microns and 20 nm surface modified silica (13). it was stated that higher filler loading reduces volumetric shrinkage and minimizes the development of shrinkage stresses in rbcs. this was attributed to the reduction in the amount of resin, thereby reducing the component responsible for shrinkage (45, 46). furthermore, it was concluded that the use of low shrinkage composite restorations significantly strengthen maxillary premolars with mod preparations under compression loadings (25). the presence of nanocluster provides increased mechanical properties and improves the damage tolerance and enhances the longevity of nanocluster rbc restorations (47-49). in this research, the fracture load of teeth restored with filtek z250 xt (group 3) (0.6876 kn) was higher than that of those restored with filtek p90 (group 5) (0.6726kn). additionally the percentage of increase in strength of teeth restored with filtek z250 xt (group 3) was higher than those restored with filtek p90 (group 5). this may be due to the differences in the filler loading and type. the filler loading of filtek z250 xt restorative system which is higher than that of filtek p90 (76 wt. %, 55 vol.%). in addition, filtek z250 xtcomposite material has silica/zirconia clusters “nanoclusters” with average filler size 0.1-10 microns and 20 nm surface modified silica in comparison with the spherical filler particles of filtek p90 (0.1-2 μm) (13). it was reported that if filler contents were increased with decreasing particle size and interparticle spacing, this would increase the fatigue limit due to increased obstacles for crack growth (50). in addition, it was concluded that nanocluster particles possess different mechanical properties compared with filler particles possessing a spheroidal or irregular morphology. additionally, the incorporation of nanoclusters particles into a conventional resin matrix may modify the subsequent failure mechanisms and provide enhanced damage tolerance unique to nanoclusters reinforced rbcs (51). in this study, the mean fracture load for teeth restored with sdr was (0.799 kn) which was the highest among the restored groups with no significant difference in comparison to group 3 (filtek z250 xt). the percentage of increase in j bagh college dentistry vol. 26(1), march 2014 fracture resistance of restorative dentistry 12 strength was (71.12%) which is the highest in comparison with the other restored groups. these findings may due to the elastic buffer effect of using a low-viscosity flowable composite. it was determined that polymerization shrinkage and the concomitant stresses upon the restoration-tooth interface have an influence upon the final outcome of extensive composite resin restorations. in which the shrinkage stress generated by a subsequent layer of higher modulus resin composite can be absorbed by an elastic intermediary layer, thereby reducing the stress at the tooth-restoration interface manifested clinically as a reduction in cuspal deflection (52). further, the results of this study showed that there was a significant difference existed between teeth restored with sdr (group 4) and those restored with filtek p90 (group 5). these findings may be attributed to the elastic buffer effect of using low viscosity flowable composite and the characteristic low contraction stress and low modulus of elasticity of sdr flow in comparison with silorane restorative material which had only low polymerization shrinkage. it was stated that sdr flow achieved significantly lowest contraction stress (1.1±.01mpa) in contrast to silorane-based composite (3.6±.03mpa). moreover, the elastic modulus of sdr flow (9.2 mpa) was lower than that of filtek p90 (12.5 mpa) (53, 54). besides, it was stated that the flexural modulus of filtek p90 (7.9 mpa) is higher than that of sdr flow (4.9 mpa) (53). moreover it was postulated that high flexural modulus has been identified to inhibit the ability of a material to resist deformation due to loading and the accumulation of surface and bulk defects resulting in premature failure (55, 56). in this study, the mean load value of teeth restored with filtek p90 (group 5) was the lowest among the restored groups (0.6726 kn) and the percentage of increase in strength (59.87%) was the lowest in comparison with restored teeth groups. however, group 5 had a significant increase in fracture strength when compared with the unrestored group 2. it was reported that restoration with filtek p90 improved the fracture strength of endodontically treated teeth in comparison with unrestored teeth (42).this may be due to the strengthening effect of adhesive restoration which was discussed previously, in addition to the low polymerization shrinkage features of silorane-based composite restorations (57).additionally, the low mean value of fracture load of group 5 may be due to the high flexural modulus of silorane (55, 56) fracture type and mode based on the findings of this study, 80% of the samples in the intact control group (group 1) presented favorable fracture type. however, all the samples in the unrestored teeth group (group 2) presented unfavorable fracture type (100%). these findings may be due to the presence of the palatal and buccal cusps with intact mesial and distal marginal ridges in the control group and the weakening effect of cavity preparation and endodontic treatment in unrestored teeth with endodontic treatment which was discussed previously. in this study, it was revealed that 90 % of the samples of teeth restored with filtek z250 xt presented unfavorable type of fracture. in addition, the majority of the samples in this group (group 3) presented adhesive type of failure (90%). this may be due to that filtek z250 xt characterized by high compressive strength (385 mpa) and fracture toughness (2.03 mpa m1/2) (13). it was stated that high compressive strength materials translate to sustained resistance against a heavy load, especially when used as a posterior restoration (58). further, the fracture toughness represents the material’s ability to be plastically deformed without fracture, or the amount of energy required for fracture and it also represents the material’s ability to resist crack propagation (59). therefore, filtek z250 xt may have a higher resistance to crack propagation, so the failure occurred at the weakest link which is the tooth/composite interface. in addition, self-etch adhesive exhibits a weak hybrid layer, which is generally accompanied by a weak adhesive layer which may explain the high percentage (90%) of adhesive failure in teeth restored with filtek z250 xt (group 3) (14). however, these findings should be supported by scanning electron microscope (sem) to evaluate the failure point whether it isbetween the restoration and bonding, bonding and the tooth or within the adhesive layer. in this study, the majority of the teeth restored with sdr (group 4) presented 90% with unfavorable type of fracture. moreover, 90% of the samples presented adhesive mode of failure. as discussed previously, sdr restorative material is characterized by low elastic modulus (9.5 mpa) (53) which may explain the higher load values among the restored groups. however, the low elastic modulus may explain the severity of fracture type presented in this group. in which the stresses in the compression test were transmitted to the adjacent tooth structure. this may in turn results in the concentration of stresses in the inner dentine and occurrence of unfavorable fracture. it was concluded that the higher the elastic modulus j bagh college dentistry vol. 26(1), march 2014 fracture resistance of restorative dentistry 13 of the restorative material when the joint of restorative material / dental structure is stressed, the lower the deformation of dental structures. in contrast, the low elastic modulus of composite resin promoted less restoration stiffness and a greater distribution of stresses produced by the compression test to adjacent tooth structure which resulted in catastrophic type of fracture (43). additionally, the weak adhesive layer of self-etch adhesive that used in this study may explain the high percentage (90%) of adhesive failure in this group (14). however, these findings should be further investigated by the aid of sem. on the other hand, teeth restored with filtek p90 (group 5) presented 90% of the samples with unfavorable type of fracture. the majority of the samples (80%) exhibited mixed mode of failure. these findings may be dueto the inability of silorane-based restorative material to resist crack propagation and to plastically deform before fracture under compressive loading. these findings may also be due to the effect of low fracture toughness of silorane (1.64 mpam1/2) (58).additionally, it was revealed that the silorane polymerization starts with the initiation process of an acidic cation that opens the oxirane ring and generates a new carbocation, subsequently, chain propagation and cross-linking polymerization follows (57). however, during this process, the acidic si–oh groups on the quartz-filler particles can potentially result in an undesired initiation of the cationic polymerization process. this unwanted process can increase the overall number of impure pockets of unreacted oxirane monomers and can potentially induce failure of the material when subjected to a compression stress (60). in addition to the effect of low fracture toughness, the occurrence of high percentage (80%) of cohesive failure may be due to the low compressive strength property (254 mpa) of silorane-based restorative material (58). furthermore, it was recognized that the ringopening polymerization of the silorane is cationic reaction and that no oxygen inhibition layer exists on the surface of the composite after polymerization in air which plays a very important role in adhesion between successive resin layers (61). it was stated that a decrease in shear bond strengthbetween the layers in the silorane composite and an increase in the cohesive failure was noted between those successive layers (61). these findings may explain the high percentage (80%) of cohesive mode of failure in teeth restored with filtek p90. finally, based on the findings of this study and in term of fracture resistance, resin composite restoration of weakened endodontically treated premolars provides some strengthening effect; however, the dependence on this type of restorations resulted in unrestorable fracture type. perhaps direct restorations should be considered as a valid interim restoration for weakened root filled teeth before cuspal coverage can be provided. furthermore, this restoration is material dependent, which must be taken in consideration in the selection of appropriate composite material that could enhance the fracture resistance of endodontically treated teeth. references 1. de munck j, van landuyt k, peumans m, poitevin a, lambrechts p, braem m. a critical review of the durability of adhesion to tooth tissue: methods and results. j dent res 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frankenberger r, kramer n, petschelt a. strength and fatigue performance versus filler fraction of different type of direct dental restoratives. j biomed mater res part b: appl biomater 2006; 76:114–20. 57. weinmann w, thalacker c, guggenberger r. siloranes in dental composites. dental materials 2005; 21: 68–74. 58. lien w, vandewalle ks. physical properties of a new silorane-based restorative system. dent mater 2010; 26: 337-44. 59. powers jm, sakaguchi rl. craig’s restorative dental materials. 12th ed. st. louis, mo: mosby inc.; 2006. 60. fleming gjp, awan m, cooper pr, sloan aj. the potential of a resin-composite to be cured to a 4 mm depth. dent mater 2008; 24: 522-29. 61. tezvergil-mutluay a, lassila lv, vallittu pk. incremental layers bonding of silorane composite: the initial bonding properties. j dent 2008; 36(7): 560–3. muna.doc j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 121 immunohistochemical assessment of tumor suppressor gene wwox in relation to proliferative marker ki67 proteins expression in giant cell lesions of the jaws and giant cell tumor of long bones muna salih merza, b.d.s., m.sc., ph.d. (1) abstract background: peripheral giant cell lesion (pgcl) and central giant cell lesion (cgcl) of the jaws have a distinct clinical behavior.giant cell tumour (gct) is a benign locally aggressive neoplasm affects the long bones. both lesions are characterized histologically by multinucleated giant cells in a background of ovoid to spindle-shaped mesenchymal cells. the ww domain-containing oxidoreductase (wwox) gene is located at 16q23.1–16q23.2, a region that spans the second most common human fragile site, fra16d, at 16q23.2.the ki-67 antigen is a nuclear protein that is associated with and may be necessary for cellular proliferation.ki-67 protein is present during all active phases of the cell cycle (g1, s, g2, and mitosis), but is absent from resting cells (g0). this study aimed to evaluate and compare immunohistochemical expression of tumor suppressor gene (wwox) and proliferative marker (ki67) in giant cell lesions (gcls) of the jaws and long bones. materials and methods: forty five retrospective paraffin embedded tissue blocks of giant cell lesions of the jaw and long bones were included in this study.sections were stained immunohistochemically with anti wwox and anti ki67 monoclonal antibodies. results: positive wwox expression was found in 12 cases (80%), 14cases (93.3%)and12 (80%) of cgcg, pgcg and gct studied cases respectively, with thehighest strong positive expression observed in pgcg.positive ki67 expression was found in 12 cases (80% ), 13cases ( 86.7 % )and10(66.7%) of cgcg,pgcg and gct studied cases respectively with the high proliferative expression score has been recorded in pgcg .statistically highly significant difference was found in the ki67expression among different giant lesion types (p=0.006), whilenon-significant difference was found in wwox expression. non-significant correlation was found between expression of wwoxand ki67 in cgcg, pgcg and gct studied cases. conclusions: similar immunohistochemical expression of wwox and ki67 ingiant cell lesions of the jaw and gct of long boneswith non-significant correlation between them in different studied lesionssuggests that those lesions may be the same disease but with different clinical behavior. keywords: wwox, ki67. (j bagh coll dentistry 2015; 27(1):121-127). introduction central giant cell lesion (cgcl) and peripheral giant cell lesion (pgcl) are pathological conditions of the jaws that share the same microscopic features, but differ clinically in terms of their behavior (1). they are of unknown origin located more frequently in the mandible than maxilla, occurring in the 2nd and 3rd decades of life. females are more frequently affected than males (2,3). peripheral giant cell lesion (pgcl) is considered as a reactive process associated with a local irritating factor that shows low recurrence after treatment, especially if the irritating factor is eliminated. on the other hand, central giant cell lesion (cgcl) presents a variable clinical behavior ranging from slow and asymptomatic growth without recurrence to rapid, painful and recurrent growth (4). the gct of long bones is a rare benign neoplasm, characterized by local aggressiveness, high recurrence rates and metastasis to the lung (5).it apparently arises from the mesenchymal cells of the connective tissue frame work. (1) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad these cells differentiate into fibroblast-like stromal components and multinucleated cells of osteoclastic type (6-9). the principal characteristic of this tumor is the unpredictable biological behavior (8). the wwox gene (ww-domain containing oxidoreductase) is a candidate tumor suppressor gene located at 16q23.3-24.1, spanning the second most common fragile site, fra16d (10). the wwox protein contains two n-terminal ww domains and a central short chain oxidoreductaselike domain (11), that mediate protein–protein interactions. ww domains mediate complexes associated with signaling pathways implicated in a variety of cellular processes such as transcriptional regulation and protein stability (12). wwox physically interacts via its first ww domain with the p53 homolog, p73 and induces cell apoptosis (13). numerous studies have correlated loss of wwox expression with cancer development, including some associating wwox alteration with poor prognosis and outcome in various cancer types (11), suggesting a growth advantage for tumors with loss of wwox. ki-67 represents a nuclear protein forming part of dna replicase complex that provides a simple, rapid j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 122 and reliable means of evaluating the growth fraction of neoplastic cell populations (14). ki-67 has a short half-life; hence it can be used as a marker for actively proliferating cells. since it is not expressed during the resting phase of a cell cycle, it functions as a specific indicator of cellular proliferation (15). materials and methods forty five formalin-fixed, paraffin-embedded tissue blocks (15 cases of cgcg, 15 cases of pgcg and 15 cases of gct) were obtained randomly from the archives of the department of oral & maxillofacial pathology/ college of dentistry/ university of baghdad and al-shaheed ghazi hospital/ medical city / baghdad during the period (1976-2012). the clinical data were obtained from surgical reports available with the tissue specimens .the diagnosis of each case was confirmed by examining the hematoxylin and eosin (h&e) sections by two experienced pathologists. four µm thick sections were cut for immunoshitochemcial staining with anti wwox and anti ki67 monoclonal antibodies (mabs) (abcamuk). abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit (catalog no. ab80436, cambridge, uk) was used for both primary antibodies (wwox, ki67).negative and positive controls were included in each ihc run. human colon carcinoma tissue blocks were used for wwox and tonsil tissue blocks for ki657 (according to antibodies manufacturer). for immunohistochemistry, the sections were mounted on positively charged slides. slides were baked in hot air oven at 65°c overnight. sections were sequentially dewaxed through a series of xylene, graded alcohol and water immersion steps. antigen (ag) retrieving was done for both wwox and ki67 abs as recommended by the manufacturer. then endogenous peroxidase activity was blocked followed by blocking the nonspecific staining. primary abs (100 ml) was applied for each section. a dilution of (1:75) for wwox, and (1:100) for ki67 were used. after an overnight incubation and washing with phosphate buffered solution (pbs), secondary abs were applied, incubated and rinsed with a stream of pbs. primary abs were visualized with 3, 3diaminobenzidine (dab) chromogen, then counterstained with mayer's hematoxyline, dehydrated and mounted. immunohistochemical expression recorded in percentage of stained stromal cells and multinucleated giant cells in the studied lesions was classified and scored as follows: for wwox, cytoplasmic or cytoplasmic/nuclearstaining pattern was considered positive for wwox immunostaining. immunoreactivity was classified as follows: (1) negative <10%, (2) weak positive 10-50% and (3) strong positive ≥ 50% (10). for ki67 any brown nuclear staining, regardless of its intensity was considered to be positive (16,17). immunoreactivity was classified as follows: (-) ≤ 5% negative, (+) 6-25 % low proliferation ,(++) 26-50% moderate proliferation and (+++) 51-100% high proliferation of the considered positive cells (18). all the data of the studied samples were subjected to computerized statistical analysis using spss version 19 computer program. kruskall-wallis h test was used to compare between the percentages of markers expression among lesion types. mann-whitney u test used after kruskallwallis h test if it is significant to test any significant difference between each two lesions. spearman’s rank correlation test was used to test the relation between the markers in each lesion type. the positive sign of r value means there is direct relation and vice versa. results the results of present study revealed female predilection in both central and peripheral giant cell granulomma comprising (60%) of (9) cases in each of them. similarly, in gct, there was female predilection comprising (53.3 %) of 8 cases as shown in table (1 and 2). the age range of the patients was 8-52years with a mean of (25.93±13.5) yearsfor c.g.c.g. and age range of 3-75years with a mean of (41.6±23.5) yearsfor peripheral giant cell granuloma whereas for patients with giant cell tumor the age range was 2-73 years with a mean of (32.5±17.5) years. as demonstrated in table (1 and 2). considering site distribution, giant cell granuloma lesions were distributed between upper and lower jaw as follow: c.g.c.g. presented in maxilla in 20% (3 cases) and in the mandible80% (12 cases), p.g.c.g occurred in maxilla in 46.7% (7 cases) and in the mandible 53.3% (8 cases). whereas, giant cell tumor cases were distributed among various body regions beginning with head area andradius bone 33.33% (5 cases) for each of them followed by femur bone 26.66% (4 cases) and tibia bone 6.7% (1 case), as shown in table (1 and 2). j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 123 table 1: the demographic and clinical description of 15 patients with central giant cell granuloma and 15 patients with peripheral giant cell granuloma lesion type site sex age mand. maxilla male female mean s.d. min. max. cgcg 12 (80%) 3 (20%) 6 (40%) 9 (60%) 25.93 13.6 8 52 pgcg 8 (53.3%) 7 (46.7%) 6 (40%) 9 (60%) 41.6 23.5 3 75 table 2: the demographic and clinical description of 15patients with giant cell tumor sex age site male female mean sd min. max. tibia femur radius head 7 (46.7%) 8 (53.3 %) 32.5 17.5 2 73 1 (6.7%) 4 (26.7%) 5 (33.3%) 5 (33.3%) assessment of the immunohistochemical expression of wwox and ki67 mabs positive wwox immunostaining was detected as brown cytoplasmic or cytoplasmic with nuclear expression, mostly in multinucleated giant cells and some of mononuclear cells of cgcg, pgcg and gct (fig. 1-3). analysis ofimmunohistochemicalexpression of wwox ab. in cgcg,pgcg and gct revealed positive expression in 12 cases (80% )of cgcl , 14 cases (93.3 % )of pgcl and12(80%) of gct studied cases .results revealed predominance of score 3 i.e strong positive expression in bothcgcg and pgcg with 10 cases ( 66.7 %) of cgcg and 12 cases ( 80%) of pgcg respectively ,whereas in gct , positive cases of wwox expression revealed equal distribution between strong and weak expression scores with 6 cases (40 %) for each one as shown in the table(3). table 3: immunohistochemical expression of wwox in all giant cell lesions lesions i ii iii total c.g.c.g. 3 (20%) 2 (13.3%) 10 (66.7%) 15(100%) p.g.c.g. 1 (6.7%) 2 (13.3%) 12 (80%) 15(100%) g.c.t. 3 (20%) 6 (40%) 6 (40%) 15(100%) positive ki67 immunostaining was detected as brown nuclear expression of stromal cells ofcgcg, pgcg and gct (fig. 4-6). analysis of immunohistochemicalexpression of ki67 ab. in cgcg,pgcg and gct revealed positive expression in 12 cases (80% ) of cgcl , 13cases ( 86.7 % )of pgcl and10(66.7%) of gct studied cases .positive casesrevealed predominance of high proliferative expression scorein bothcgcg and pgcg with 9 cases (60%) of cgcg and 10 cases (66.7%) of pgcg respectively ,whereas in gct, results revealed low proliferation score in 5 cases (33.3 %), 3 cases (20%) with moderate proliferation score and the remaining 2 cases (13.3%) with strong expression scoreas shown in the table(4). table 4: immunohistochemical expression of ki67 in all giant cell lesions lesions -ve i ii iii c.g.c.g. 3 (20%) 1 (6.7%) 2 (13.3%) 9 (60%) p.g.c.g. 2 (13.3%) 1 (6.7%) 2 (13.3%) 10 (66.7%) g.c.t. 5 (33.3%) 5 (33.3%) 3 (20%) 2(13.3%) j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 124 figure 1: positive wwox immunostaining in cgcg(x40) figure2: positive wwox immunostainig in pgcg(x40) figure 3: positive wwox immunostaining in gct(x40) figure 4: positive ki67 immunostaining in cgcg (x40) figure 5: positive ki67 immunostaining in pgcg (x40) figure 6: positive ki67 immunostaining in gct(x40) j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 125 comparison the percentages of ki67 and wwox expression among different studied giant lesion types statistical analysis using kruskal wallis and mann whitney tests revealed that, there is a highly significant difference in the expression of ki67 between the high pgcg mean percentage (65%) &low gct mean percentage (25.67%) withp value =0.006 .on the other hand ,non significant difference was found in wwox expression amongthe studied giant lesions (p=0.060) (table 5 and 6) table 5: comparison the percentages of ki67 and wwox markers among the lesions markers lesions descriptive statistics comparison n median mean s.d. min. max. mean rank kruskall wallis h test d.f. p-value ki67 cgc 15 60 51.67 33.31 0 90 24.27 10.39 2 0.006 (hs) pgc 15 80 65 33.49 0 95 29.97 gct 15 20 25.67 25.06 0 75 14.77 wwox cgc 15 80 60 33.91 0 90 24.37 5.64 2 0.060 (ns) pgc 15 80 69.33 24.92 0 90 27.83 gct 15 50 45 31.11 0 85 16.80 table 6: mann-whitney u test after kruskall-wallis h test for ki67 lesions mean rank mann-whitney u test z-test p-value cgc 13.27 79 -1.39 0.162 (ns) pgc 17.73 cgc 19 60 -2.19 0.028 (s) gct 12 pgc 20.23 41 -2.97 0.003 (hs) gct 10.77 correlation between thepercentages of ki67 and wwox in the studied cell lesions: results of present study and according to spearman’s test correlation revealed nonsignificant correlation between the expression of wwoxand ki67 in cgcg, pgcg and gct studied cases (table 7-9). table7: relation between the percentages of ki67 and wwox in cgcg markers wwox ki67 r 0.488 p-value 0.065 (ns) table 8: relation between the percentages of ki67 and wwox in pgcg markers wwox ki67 r 0.315 p-value 0.253 (ns) table 9: relation between the percentages of ki67 and wwox in gct markers wwox ki67 r 0.339 p-value 0.216 (ns) discussion giant cell lesions of the jaw and gct of long bones have a distinct clinical behavior. both lesions are characterized histologically by multinucleated giant cells in a background of ovoid to spindle-shaped mesenchymal cells. there is a basic question whether both lesions are separate entities or variants of the same disease, (18) and if biological behavior differences are supported by a distinct pattern of certain markers proteins expression or not. therefore this study was conducted in an attempt to assess the expression of wwox tumor suppressor gene and proliferative marker ki67 in giant cell lesions of the jaw bones in comparison to the giant cell tumor of long bones and to correlate their expression with each other in each studied lesion j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 126 to explain its possible role in the biological behavior of giant cell lesions and tumor. the wwox gene is a recently cloned tumor suppressor gene that spans the fra16d fragile region. wwox protein contains two ww domains that are generally known to mediate protein-protein interaction (13). the subcellular localization of wwox has been a controversial issue among the different research groups. numerous immunohistochemical studies have shown that wwox is a cytoplasmic protein both in normal and neoplastic tissues (20-25). other laboratories have reported that wwox localizes in mitochondria and nuclei of some cells (26). in the present study, both cytoplasmic and cytoplasmic/nuclear staining pattern was considered positive in both mononuclear and multinucleated giant cells. results revealed strong positive wwox expression in majority of pgcg and cgcg studied cases, mostly in the giant cells; this finding is supported by results of previous study (27). these findings support what previously reported that wwox has an important role in apoptosis since it is mostly expressed in giant cells which have been shown to be the main source of this apoptotic event (26). concerninig expression in gct ,and up to my knowledge this is the first study that attempt to compare wwox expression in giant cell lesions of the jaw bones and giant cell tumor of long bones.the present finding showed that the majority of gct cases showed positive expressionwith non-significant difference obtained in wwox expression amongcgcg, pgcg and gct studied cases.this finding is in accordance with previous study conducted using other tumor suppressor gene (28) which supports the theory that these lesions are a spectrum of disease rather than different entities. on other hand the present findings indicate that wwoxcould not be used to explain the differences between the giant cell lesions of the jaws and gct of the long bones. the ki-67 antigen is a human nuclear protein used as a marker for cellular proliferation (15) ki67 antigen is expressed during the g1, s, g2 and m phases of the cell cycle within the nucleus but is not expressed during the g0 (resting) phase, and thus it is a widely accepted proliferation marker and is useful in predicting the development of human neoplasm (14). although the biological behavior is not only reflected by the proliferation index by tumor cells, but still it represents a clue on tumor activity .the results of previous study showed greaterki-67 immunoreactivity in pgcl compared to cgcl(29). similar results obtained in the present study. additionally, cgcg and pgcg had a higher proliferative activity than gct with a highly significant difference in ki67 expression was found between cgg, pgcg and giant cell tumor. similar results obtained in previous studies (29-31). however, souza, et al. stated that the differences observed in proliferative activity do not explain the different biological behavior of cgcg and gct. they emphasized that since cgcg and gct occur in different sites, it is difficult to compare accurately their biological evolution (28). they suggested that cgcg and gct could represent variants of the same disease. references 1. matos fr, nonaka cfw, miguel mc da c , galvão hc, de souza lb, freitas r de a. immunoexpression of mmp-9, vegf, and vwf in central and peripheral giant cell lesions of the jaws j oral pathol med 2011 40: 338–344 2. corso e de, politi m, paludetti g. advanced giant cell reparative granuloma of the mandible: radiological features and surgical treatment. acta otorhinolaryngol 2006; 3:168-172. 3. neville bw, damm dd, allen cm, bouquot je. bone pathology in: oral and maxillofacial pathology. 3rd ed. philadelphia: wb sanders; 2009, pp.507-629. 4. de matos fr, de moraes m, nonaka cfw, lélia de souza lb, freitas rda. immunoexpression of tnf-α and tgf-β in central and peripheral giant celllesions of the jawsj oral pathol med 2012; 41: 194–9 5. kumta sm, huang l, cheng yy, chow lt, lee km, zheng mh. expression of vegf and mmp-9 in giant cell tumor of bone and other osteolytic lesions. life sci 2003; 73:1427-36. 6. zheng mh, robbins p, xu j, et al. the histogenesis of giant cell tumour of bone: a model of interaction between neoplastic cells and osteoclasts. histol histopathol 2001; 16: 297-307. 7. pogrel, m.a. calcitonin therapy for central giant cell granuloma. j oral maxillofac surg 2003; 61: 649 8. werner m. giant cell tumor of bone: morphological, biological and histogenetical aspects. int orthop 2006; 30-489. 9. lanza a, laino l, cirillo n clinical practice: giant cell tumour of the jaw mimicking bone malignancy on three-dimensional computed tomography (3d ct) reconstruction. open dent j 2008; 2: 174-178. 10. pimenta fj, gomes da, perdigão pf, barbosa aa, romano-silvama, gomez mv, aldaz cm, de marco l, gomez rs. characterization of the tumor suppressor gene wwox in primary human oral squamous cell carcinomas). int j cancer 2006; 118(5):1154-8. 11. aqeilan ri, croce cm wwox in biological control and tumorigenesis. j cell physiol 2007;212(2):307-10 12. sudol m, recinos cc, abraczinskas j, humbert j, farooq a. . ww or wow: the ww domains in a union of bliss. iubmb life 2005; 57:773–78. 13. aqeilan ri, pekarsky y, herrero jj, et al. functional association between wwoxtumoursuppressorprotein and p73, a p53 homolog. proc natl acad sci usa 2004; 101: 4401–6. j bagh college dentistry vol. 27(1), march 2015 immunohistochemical oral diagnosis 127 14. scholzen t, gerdes j. the ki 67 protein: from the known and the unknown (review) j cellphysiol 2000; 182: 311–22. 15. ismail fw, shamsudin am, wan z, daud sm, samarendra ms. ki-67 immuno-histochemistry index in stage iii giant cell tumor of the bone. j experimental & clinical cancer res 2010; 29:25 16. pan c, ho d, chen w, et al. ki67 labelling index correlate with stage and histology but not significantly with prognosis in thymoma.histopathol 1998; 33: 453458. 17. lindboe a, liljegren a. tumor markers in malignancies. bmj 2000; 320(7232): 424-7. 18. alves fa, pires fr, de almmeida op, lopes ma, kowalski lp. pcna, ki67 and p53 expression in submandibular salivary gland tumors. j oral maxillofac surg 2004; 33:593-7. 19. de souza pe, paim jf, carvalhais jn, gomez rs. immunohistochemical expression of p53, mdm2, ki67 and pcna in central giant cell granuloma and giant cell tumor. oralpathol med 1999; 28(2):54-8. 20. aqeilan ri, kuroki t, pekarsky y, albagha o, trapasso f, baffa r, huebner k, edmonds p, croce cm. . loss of wwox expression in gastric carcinoma. clin cancer res 2004a; 10: 3053–8. 21. guler g, uner a, guler n, han sy, iliopoulos d, hauck ww, mccue p, huebner k. . the fragile genes fhit and wwox are inactivated coordinately in invasive breast carcinoma. cancer 2004; 100: 1605–14. 22. nunez mi, ludes-meyers j, abba mc, kil h, abbey nw, page re, sahin a, klein-szanto aj, aldaz cm. . frequent loss of wwox expression in breast cancer: correlation with estrogen receptor status. breast cancer res treat 2005a; 89: 99–105. 23. 23. nunez mi, rosen dg, ludes-meyers jh, abba mc, kil h, page r, klein-szanto aj, godwin ak, liu j, mills gb, aldaz cm. .wwox protein expression varies among ovarian carcinoma histotypes and correlates with less favorable outcome. bmc cancer 2005b; 5:64. 24. nunez mi, ludes-meyers j, aldaz cm. wwox protein expression in normal human tissues. j mol histol 2006; 37: 115–125. 25. aqeilan ri, trapasso f, hussain s, costinean s, marshall d, pekarsky y, hagan jp, zanesi n, kaou m, stein gs, lian jb, croce cm. targeted deletion of wwox reveals a tumor suppressor function. pnas 2007; 104: 3949–54. 26. chang ns, hsu lj, lin ys, lai fj, sheu hm. . ww domain-containing oxidoreductase: a candidate tumor suppressor. trends mol med 2007; 13: 12–22. 27. amaral fr, diniz mg, bernard’s vf, souza pe, gomez rs, gomes cc. wwox expression in giant cell lesions of the jaws. oral surg oral med oral pathol oral radiol 2013; 116(2): 210-3. 28. kader oa, abdullah bh, edward l. histopathological and immunohistochemical study of giant cell granuloma of the jaw and giant cell tumor of long bones (comparative stud).the iraqi postgraduate medical j 2011;10 (1):33-39. 29. souza pe, mesquita ra, gomez rs evaluation of p53, pcna, ki-67, mdm2 and agnor in oral peripheral and central giant cell lesions. oral dis 2000; 6(1):35-9. 30. de souza pe, paim jf, carvalhais jn, gomez rs. immunohistochemical expression of p53, mdm2, ki67 and pcna in central giant cell granuloma and giant cell tumor. j oral pathol med 1999; 28:54-8. 31. maria do socorro aragão; marta rabellopiva; cassiano francisco weegenonaka; roseana de almeida freitas; lélia batista de souza; leão pereira pintocentral giant cell granuloma of the jaws and giant cell tumor of long bones an immunohistochemical comparative study. j appl oral sci 2007;15:4. الخالصة ان ورم الخالیا العمالقة ھومن االورام الحمیدة المحددة .ان آفة الخالیا العمالقةالطرفیةوآفة الخالیا العمالقة المركزیة للفكین لھاسلوكسریري واضح :الخلفیة من الخالیا البیضویة الى مغزلیة الشكل من خالیا اللحمة العدوانیة یصیب العظام الطویلة وتتمیز كال االفات تشریحیا من الخالیا العمالقة المتعددة النوى في خلفیة ھو ) ki-67(ان بروتین .وھي المنطقة التي تضم الموقع البشري الھش االكثر شیوعا) 16q23.2–16q23.1(یقع ضمن منطقة) wwox(ان جین .المتوسطة ھدفت .ثناء كل االطوار الفعالة من دورة الخلیة ولكنھ غائب عن الخالیا الساكنةان ھذا البروتین موجود ا.بروتین نووي مقترن بعملیة تكاثر الخالیا وضروري لھا في آفات الخالیا العمالقة للفكین ) ki67(ومعلم التكاثر ) wwox(ھذه الدراسة الى تقییم ومقارنة االظھار الكیمیائي النسیجي المناعي للجین المثبط لالورام .والعظام الطویلة تم صبغ .تم تضمین خمس واربعین عینة نسیجیة استرجاعیةمطمورة بالبارافین من آفات الخالیا العمالقة للفكین والعظام الطویلة في ھذه الدراسة : المواد والطرق ).ki67(وال) wwox(المقاطع النسیجیة لھذه العینات باستخدام الصبغات النسیجیة المناعیة بمضادات ال (,)cgcg(من الحاالت المدروسة من ال %) 80( حالة 12و%) 93.3(حالة 14,%) 80(حالة 12في ) wwox(ل وجد االظھار االیجابي ل:النتائج pgcg (و)gct (ووجد االظھار االیجابي لل .على التوالي)ki67 ( حالة 12في)حاالت من الحاالت المدروسة من 10و %) 86.7(حالة 13,%) 80 )cgcg ( ,)pgcg(و)gct (یل مؤشر عالي للتكاثر في على التوالي مع تسج)pgcg.( وجد فرق كبیر للغایة بین الحاالت المدروسة في اظھار ال )ki67 ( مع عدم وجود فرق بینھا في درجة اظھار ال)wwox.( تم العثور على عالقة غیر كبیرة بین ال)wwox ( و)ki67 ( في مختلف آفات الخالیا .العمالقة المدروسة في آفات الخالیا العمالقة في الفكین والعظام الطویلة مع وجود عالقة غیر معنویة ) ki67(و) wwox(الكیمیائي النسیجي المناعي للتشابھ الظھور :االستنتاجات .بینھما في مختلف الحاالت المدروسة االمر الذي یدل على ان ھذه اآلفات قد تكوننفس المرض ولكن بحاالت سریریة مختلفة 2. bashaer f.doc j bagh college dentistry vol. 27(4), december 2015 the influence of restorative dentistry 8 the influence of different fabrication techniques and preparation designs on the marginal adaptation of ceramic veneers (an in vitro comparative study) bashaer abd el-sahib najim, b.d.s. (1) inas i. al-rawi, b.d.s., m.sc. (2) abstract background: ceramic veneers represent the treatment of choice in minimally invasive esthetic dentistry; one of the critical factors in their long term success is marginal adaptation. the aim of the present study is to evaluate the marginal gap of ceramic veneers by using two different fabrication techniques and two different designs of preparation. material and methods: a typodont maxillary central incisor used in the preparation from which metal dies were fabricated, which were in turn used to make forty stone dies. the dies divided into four experimental groups, each group had ten samples: a1: prepared with butt-joint incisal reduction and restored with ips e.max cad, a2: prepared with overlapped incisal reduction and restored with ips e.max cad. b1: prepared with butt-joint incisal reduction restored with ips e.max press. b2: prepared with overlapped incisal reduction and restored with ips e.max press. the marginal gap was measured with direct view technique using digital microscope at a magnification of 230x. measurements were recorded for four surfaces for each sample and the maximum value was taken to represent that sample. results: the data were analyzed with two-way anova and independent samples t-tests. these tests revealed highly significant effects of both the preparation design and the technique of fabrication on the marginal gap (p=0.00), with cad/cam veneers, group a1 recorded the least marginal gap and pressing group, b2 showed the highest gap values. there was no significant effect of the interaction between the two parameters on the marginal gap. conclusion: the cad/cam veneers with butt joint incisal reduction produced the most accurate margins while the least favorable combination was the pressable ceramic veneers with overlapped incisal reduction. key words: marginal adaptation, cad/cam veneers, pressable veneers, ips e.max system. (j bagh coll dentistry 2015; 27(4):8-14). introduction advances in all-ceramic systems, adhesive materials, and clinical techniques have enabled the porcelain laminate veneer to evolve into highly esthetic restorations with excellent resistance to staining, abrasion and good marginal fit. it became treatment of choice in minimally invasive aesthetic dentistry(1). long term clinical success of porcelain veneers depends on number of critical factors; one of them is the marginal adaptation of the restoration of the tooth surface. no material has the ability to provide complete seal of the restoration-tooth interface, so it is crucial to at least minimizing the marginal gap to prevent the exposure of the adhesive resin cement to the oral cavity that would lead to eventual disintegration resulting in microleakage, recurrent caries, discoloration of the tooth structure, and fracture of the cemented veneers(2). past clinical experiences and about 30 years of data show that porcelain laminate veneers are very predictable and successful when bonded to enamel. (1) m.sc. student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor. department of conservative dentistry, college of dentistry, university of baghdad. current best practices in use of porcelain laminate veneers are to use a minimal, or noninvasive, tooth preparation that is restored with a thin porcelain veneer(3). most thin veneers are made of lithium disilicate ceramic, this material, compared with other materials, for example, ceramics reinforced by leucite, has greater biaxial strength and fracture toughness(4). materials and methods a right maxillary central incisor typodont used for veneer preparation. first, a primary impression was taken for the typodont using alginate impression material (tropicalgin, italy) which was then poured immediately with type iv dental stone (zhermack, italy), according to manufacturers’ instructions to form the primary model that served later as a biocopy in order to restore the shape and form of the original tooth during the fabrication of the cad/cam veneers groups. a silicone index was made for the tooth in the student typodont using a putty polyvinyl siloxane material (zeta plus/soft, zhermack/clinical, italy) (fig.1) to use it after sectioning as a guide for evaluating the amount of reduction(5). j bagh college dentistry vol. 27(4), december 2015 the influence of restorative dentistry 9 figure 1: silicone index: a. impression adapted on the teeth surfaces. b. sectioning of the impression. c. labial index. d. incisal index preparation of the first design (butt-joint incisal reduction) the preparation conducted by using a high speed handpiece and ceramic veneers burs system kit (komet, germany). the preparation ended 1 mm from the cervical line(6,7). all the preparations were made 0.1 mm less than the proposed final reduction which was later removed in final finishing stage. labial reduction was 0.3 mm cervically and 0.5 mm in the middle and the incisal third(8). the final cervical margin had chamfer profile with 0.3 mm(10,11). incisal reduction was 1.5mm(10,11). the bur was held parallel to the incisal edge inclination to create butt joint incisally (fig.2). all the line angles were rounded with white stone bur using slow speed hand piece. final impression was taken for the prepared typodont tooth with additional silicone impression materials (elite p&p/putty soft, zhermack/clinical, italy) which was then poured with blue inlay casting wax to form wax pattern for the first preparation design(12). preparation of the second design (overlapped incisal reduction with palatal chamfer) the same typodont was modified for the overlapped incisal reduction preparation(1) by forming 0.5mm palatal chamfer that extend 1mm palatally, and extended it through the interproximal areas. mesial and distal corners were rounded(9) (fig.2). impression for the second preparation was taken and poured with blue inlay wax to form the wax pattern for the second design the two wax patterns were taken to the laboratory were they were sprued, invested, burned out and cast with nickel-chromium alloy to form the master metal dies. figure 2: a. butt joint incisal reduction, b. overlapped incisal reduction impression was taken for each metal die with putty additional silicone impression materials (elite p&p/hydrophilic, zhermack, italy) and light body addition silicone impression materials (elite hd plus/hydrophilic, zhermack, italy) and forty impressions were taken, twenty impressions for each preparation design. these impressions were poured with type iv dental stone (zhermack, italy) to form stone dies, i.e. ten stone dies for each experimental group. samples grouping the (40) stone dies were divided into four groups according to the preparation design and the technique used: •group a1: butt joint incisal reduction restored with ips e.max cad. •group a2: overlapped incisal reduction with palatal chamfer restored with ips e.max cad. •group b1: butt joint incisal reduction restored with ips e.max press. •group b2: overlapped incisal reduction with palatal chamfer restored with ips e.max press. pressing fabrication technique twenty ceramic laminate veneers were fabricated using ips e.max press (mo 1, ivoclar vivadent). a die spacer was applied 1mm from the preparation margin of the die. a wax pattern was manually built on each stone die to restore the anatomical features of the unprepared tooth. a silicone index fabricated on the primary model previously formed was used and a wax gauge (caliper) was used to check the thickness of wax pattern. wax patterns were attached to a 200g investment ring base using a 3mm wax sprue and a freshly vacuum mixed investment material was cast. following chemical setting of the investment, the ring was transferred to a preheated burn out oven (800 0c) after removal of the plastic base for 60 minutes. ceramic ingots were placed inside the hot ring and transferred to the pressing j bagh college dentistry vol. 27(4), december 2015 the influence of restorative dentistry 10 furnace (programat ep3000; ivoclar vivadent) which was automatically programmed to complete the pressing cycle. after cooling the room temperature, pressable ceramic laminate veneers were divested by gentle airborne particle abrasion by using gentle airborne particle abrasion using 50 µm al2o3 particles and cutting and finishing the location of the sprue were done. the mixed glazing material (ips e.max ceram glaze and stain liquids longlife) was applied on the external surfaces of the restoration and glazing is conducted according to the glaze firing parameters. cad/cam technique of fabrication: the primary model fabricated previously scanned by ineos blue scanner (sirona dental systems, bensheim, germany) to form a biocopy of the tooth before preparation in order to build a restoration to the original dimensions of unprepared tooth. then each dying stone was scanned with a 3d image. digital images of both of the primary models and the stone dies automatically analyzed and correlated with each other by a system which allow alignment of the 3-dimensional image of the primary models on top of the 3-dimensional image of dies correctly. then the designing of veneer starts in “model” phase were the margin of preparation was drawn automatically by the system, after that in copyline section, the area to be copied from the biocopy was drawn in order to design a laminate veneer identical to the original tooth form. the preparation of finishing line was marked on the digital model. after selection of the required anatomy, the veneer parameter defined as “design” phase such as minimum veneer thickness (0.4mm), spacer (0.08mm) according to sirona’s instructions, the restoration was designed according to them. ips e.max cad blocks (ivoclar vivadent) used to mill 20 veneers, 10 veneers for each preparation design. from the “mill” phase screen, the type, the size of the block (c14) and it’s position were determined, the milling process of the 20 samples was done by the cerec in-lab machine and. after completion of milling process, the restoration was separated automatically, fired in a short 30 minutes firing cycle in a ceramic furnace according to manufacturer’s instructions. this process gives the glass-ceramic with its final strength and esthetic properties. evaluation of marginal gap: measurements conducted by using dinolite digital microscope that connected to pc and at a magnification of 230x. six reference points were marked on each metal die using indelible marker. these points were two gingivally: mesially, distally and two incisally (fig.3 a). each veneer seated on its corresponding metal die with finger pressure and stabilized with sticky wax at both the mesioincisal and distocervical points(1). the dying metal placed on the stand of the microscope at a marked point so that each sample would be measured from that position and the digital microscope was directed on the sample in such a way that its horizontal plane (long axis) was perpendicular on the long axis of the metal die (fig.3 b). a b figure 3: a. ceramic veneer on the metal die with marked points. b. metal die positioned on the stand of the microscope the images were captured and processed by dinocapture software, the captured images opened in (image j) software which was used to measure the marginal gap and it gave the measurements in pixels and then converted to micrometers (fig.4). after recording sixth measurements for each veneer sample, the highest one selected to represent the maximum marginal gap of that sample. figure 4: a. incisal marginal gap, b. distal marginal gap c. fit restoration margin distally, d. restoration margin is fit incisally. results results showed that the means and standard deviations of marginal gap with minimum and maximum values performed for each group and are indicated in table 1. j bagh college dentistry vol. 27(4), december 2015 the influence of restorative dentistry 11 the highest mean value of marginal gap measured was that of group b2 (overlapped incisal reduction restored with ips e,max press veneers) followed by group b1(butt-joint incisal reduction restored with ips e,max press veneers) while the least mean value was of group a1 (buttjoint incisal reduction restored with ips e.max cad veneers) (fig.5). table 1: descriptive statistics of marginal gap for each group groups min. max. mean s.d. cad/ cam technique a1 30.26 115.73 68.03 ±23.50 a2 35.73 338.29 172.49 ±98.65 pressing technique b1 97.92 305.64 239.57 ±63.52 b2 220.15 519.32 366.25 ±116.75 figure 5: the mean values of marginal gap two-way anova test was used to detect whether there were significant effects of the technique of fabrication of veneers and the preparation design used and their interaction on the marginal gap for the four experimental groups (table 2). the technique of fabrication has a high significant effect on marginal gap (p=0.00), the design of the preparation has a highly significant factor (p=0.00). on the contrary, the effect of the interaction between those two factors was non-significant on the gap measurements (p=0.68). table 2: two-way anova for the marginal gap measurements source type iii sum of squares df mean square ftest sig. technique 333628.673 1 333628.67 47.75 0.00 design 133561.129 1 133561.13 19.11 0.00 technique * design 1233.799 1 1233.80 0.18 0.68 error 251545.259 36 6987.37 total 2510706.235 40 further analyses conducted and two independent samples of t-test used to detect the difference in marginal gap between the two designs types within each type of technique or between two techniques within each type of preparation design (table 3). ceramic veneer groups restored with ips e.max cad (a1 and a2) showed high significant effects for the design used (p=0.00), while the preparation design has a highly significant effect on pressing technique groups too (b1 and b2) (p=0.00). on the other hand, fabrication method has highly significant influence on means of ceramic veneers groups with butt joint incisal reduction making the means difference between group b1 and a1 (171.54 µm), while pressing group b2 has significantly higher mean gap than cad/cam group a2 with the same design(p=0.00). table 3: two-independent samples t-test. groups comparison mean difference t p value a1xa2 -104.46 -3.258 0.00 b1xb2 -126.67 -3.014 0.00 a1xb1 -171.54 -8.01 0.00 a2xb2 -193.76 -4.009 0.00 discussion this in vitro study evaluated the influence of different fabrication techniques and preparation designs on the marginal fitness of ceramic veneers. in order to overcome the variations that are shown in natural teeth and to make the preparation more standardized, a typodont resin tooth used from the working dies of all the samples were fabricated. maxillary central incisor selected because of it is the most common tooth restored with a laminate veneer (2). primary impression was taken for the typodont to form a primary model that served as a biocopy for group a1 and a2 to create ceramic veneers of the original form and shape of the teeth (13-15). the preparation of the tooth guided by the use of silicone indices which helped the technician in wax pattern build up to restore the original shape and form of the tooth(2,16). two preparation designs involving incisal reduction used in this study: (overlapped incisal reduction and butt joint incisal reduction), because the esthetic characteristics of the porcelain veneer are more easily handled and controlled by the dental technician with such types of preparation (17). the depth of reduction was 0.5mm at the middle while the incisal third of the labial surface reduced to 0.3mm of cervical to keep the preparation depth confined within the enamel as stated by shillingburg and grace(18). preparations were done by using depth cutter burs (komet) to j bagh college dentistry vol. 27(4), december 2015 the influence of restorative dentistry 12 guide the reduction and avoid the excessive removal of tooth structure. incisal reduction was 1.5 mm to provide adequate support and fracture resistance and required thickness of ceramic material to impart the restoration esthetics and natural translucency incisally. the second preparation was done by modifying the same tooth incisally for more standardization of the preparation depth labially and proximally (1). the ips e.max lithium disilicate glass ceramic was used in the present study for veneer fabrication, as it can be traditionally pressed or processed via cad/cam technology. it is a material that has a needle-like crystal structure providing an excellent strength and optimal durability and, superior optical properties. the crystals of both the ips e.max press and ips e.max cad are the same in composition, the microstructures of both of them are 70% crystalline lithium disilicate, li2si2o5, but the size and length of these crystals are different. this is why material properties such as cte, modulus of elasticity, and chemical solubility are the same, yet the flexural strength and fracture toughness are slightly higher for the ips e.max press material (19). measurement of marginal discrepancy was done by direct viewing method which has the advantage of being non-invasive so there was no need for any procedures on the tooth-restoration such as sectioning and it was less timeconsuming. measurements carried out by using digital microscope and with no cementation which eliminated the factor of overlapping some of the margins with excess cement(1). the marginal gap was measured at each surface of the sample then the maximum gap value was selected to represent the gap for that sample as we need to demonstrate the highest possible gap that could be measured. hence, the results of the current study appeared to be relatively higher than that of previous studies. the effect of the fabrication technique, preparation design and their interaction on the marginal gap of the experimental ceramic veneers two-way anova test used in the present study so that we can examine the interaction effect of the main factors, the technique and the design, in addition to their individual effects on the measured gap values. according to the results of the present study, a highly significant effect found for the technique of fabrication on the marginal gap.cad/ cam group (a1) with butt joint design had less gap in mean than the pressing group b1 with the same design, the same finding noticed when comparing between group a2 and b2 with the highest gap recorded for pressable ceramic group. this finding is in agreement with jha et, al.(20) who found the highest gap in the pressing group in their in vivo study but it disagrees with a study done by aboushelib et, al.(2) in which they found that cad/cam ceramic veneers were associated with significantly higher marginal gap values compared to pressable ceramic veneers, this could be explained by the latest improvements in the cerec unit and software that makes it possible to produce more clinically acceptable marginal gap of about 50μm. the designing and the milling processes involve optical scanning and formation of a digital image of the die of the prepared tooth, so the dimensions of the margins may be reproduced precisely(2). on the other hand, higher marginal gap associated with pressable ceramic veneers may be attributed to factors include the sensitive nature of the pressing technique where the wax pattern was directly built on the die by the technician, depending largely on her/his skills and experience. wax has several inherent limitations namely delicacy, thermal sensitivity, elastic memory and a high coefficient of thermal expansion(23). another factor may be the tendency of porcelain material to shrink from the thin parts of the veneer toward the area of the greatest bulk during firing process of the pressing technique(12) that leads to marginal discrepancy that could be noticed clearly with high gap mean recorded cervically for the pressing group b2 (207.98 µm). the grit blasting during divestment could also be one of the causes of marginal discrepancy by producing microcracks and chipped margins(21). eliminating laboratory steps like waxing and investing reduces the human errors and enhances the accuracy in the cad/cam technology(24). the present study showed a highly significant effect of the preparation design on the gap. it was found that group a1 involving butt joint incisal reduction preparation had significantly more accurate margins than group a2 of overlapped incisal reduction (p value=0.00) . also, group b1 showed superior marginal fit to b2 with mean difference (126.67µm), this can be explained that in the overlapped design, the margin is thin incisopalatally and could shrink toward the incisal edge, causing gap formation, in addition, those thin margins are more liable to chipping than the thick margin in butt joint design. the butt joint design had another advantage of providing an easy path of insertion and positive seating leading to a better fit(24). that agree with j bagh college dentistry vol. 27(4), december 2015 the influence of restorative dentistry 13 çelik and gemalmaz(25) while disagree with the study of lin et, al.(1) in which the effect of the design on the gap shows no significant differences. the highest gap means found incisally, in pressable group b2 that had the overlapped incisal reduction (349.5 µm). in the pressing technique steps, several errors could leading to defective margins in the incisal surface, such as shrinkage during wax build up, failure to be reproduced during the investment and liability to chipping of the divestment, in addition to the technique factor, overlapped incisal reduction design produced thinner margins incisally than in butt-joint reduction, which is more difficult to be produced in the laboratory. as shown by the two-way anova test, the effect of the interaction between the technique and the design on the gap means values was not significant which means that the technique and the design were independent on each other. when comparing between ips e.max cad group and ips e.max press group that had the butt joint design, a highly significant effect was found, however, the same influence was seen when the overlapped incisal reduction design was used, also, the means difference between butt-joint incisal reduction design group and overlapped incisal reduction group remained significantly high regardless of the technique used. the range of the mean values of marginal gap recorded mesially was (5.6-90.11 µm) and distally between (6.9-61.1 µm) which are considered within the acceptable clinical range that was determined by mclean and von fraunhofer to be within 120 µm. however, the vertical marginal gap could be rated as good for group a1 (68 µm) and acceptable for groups (a2 =172 µm and b1=239 µm), but for group b2 it was considered as unacceptable (366 µm) according to criteria established by moldovan et,al.,(22). references 1. lin tm. liu pr, ramp lc, essig me, givan da, pan yh. fracture resistance and marginal discrepancy of porcelain laminate veneers influenced by preparation design and restorative material in vitro. j dent 2012; 40(3):202-9. 2. aboushelib mn, elmahy wa, ghazy mh. internal adaptation, marginal accuracy and microleakage of a pressable versus a machinable ceramic laminate veneers. j dent 2012; 40: 670– 7. 3. radz g. minimum thickness anterior porcelain restorations. dent clin n am 2011; 55: 353–70 4. schmitter m. seydler b. minimally invasive lithium disilicate ceramic veneers fabricated using chairside cad/cam: a clinical report. j prosthet dent 2012; 107: 71-4. 5. herbert t. shillingburg jr, hobo s, whitsett l, jacobi r, susan e. brackett. fundamentals of fixed prosthodontics. st. louis: quintessence publishing co, inc; 1997 6. gresnigt m, ozcan m. fracture strength of direct versus indirect laminates with and without fiber application at the cementation interface. dental materials 2007; 23: 927-33. 7. akog˘ lu b, gemalmaz d. fracture resistance of ceramic veneers with different preparation designs. j prosthod 2011; 20: 380–4 8. touati b, miara p, nathanson d. esthetic dentistry and ceramic restorations. united kingdom: martin dunitz ltd ; 1999 9. gurel g. the art and science of atlas of porcelain laminate veneers. germany: quintessence publishing co. ltd.; 2003 10. mclaren ea. porcelain veneer preparations: to prep or not to prep. inside dentistry—may 2006 11. hekimogˇ lu c, anil n, yalc e. a microleakage study of ceramic laminate veneers by autoradiography: effect of incisal edge preparation. j oral rehabil 2004 31; 265–270. 12. khatib d, katamish h, ibrahim a.s. fracture load of two cad/cam ceramic veneers with different preparation designs.cairo dent j.2009;25(3):425-32. 13. oczan m, mese a. effect of ultrasonic versus manual cementation on the fracture strength of resin composite laminates. oper dent 2009; 34(4): 437-42. 14. batalocco g, lee h, ercoli c, feng c, malmstrom h. fracture resistance of composite resin restoration and porcelain veneers in relation to residual tooth structure in fractured incisors. dental traumatol 2011; 28: 75-80 15. abdul khaliq agh. fracture strength of laminate veneers using different restorative materials and techniques (a comparative in vitro study). j bagh coll dentistry 2014; 26(4): 1-8. 16. phelan sm. conservative porcelain veneers techniques guided by three different preparation stents. j cosmetic dentistry 2008; 24(3): 181-8. 17. gresnigt m. clinical and laboratory evaluation of laminate veneers, chapter one: introduction. thesis, department of fixed and removable prosthodontics, university of groningen, the netherlands, 2011 18. lesage bp. establishing a classification system and criteria for veneer preparations, continuing education veneer treatment classification table. compendium. 2013; 34(2). 19. ips e.max cad scientific documentation, lechtenstein: ivoclar vivadent; 2009. 20. jha r, jain v, taposh k, shah n, pruthi g.comparison of marginal fidelity and surface roughness of porcelain veneers fabricated by refractory die and pressing techniques, j prosthodont. 2013; 2. 439–44 21. santos jr.n maria jacinta moraes coelho santos jr.n amin s. rizkalla, dalia a. madani n, el-mowafy o. overview of cerec cad/cam chair side system. general dentistry. 2013 22. vojdani ma, torabi ka, farjood e b, khaledi aar. comparison the marginal and internal fit of metal copings cast from wax patterns fabricated by cad/cam and conventional wax up techniques. j dent shiraz univ med sci, sept 2013; 14(3): 118-29. j bagh college dentistry vol. 27(4), december 2015 the influence of restorative dentistry 14 23. song t, kwon tk, yang jh, han js, lee jb, kim sh, yeo is. marginal fit of anterior 3-unit fixed partial zirconia restorations using different cad/cam systems. j adv prosthodont 2013; 5: 219-25 24. prasanth v, harshakumar k, lylajam s, chandrasekharan n, sreelal t. relation between fracture load and tooth preparation of ceramic veneers an in vitro study. health sciences 2013; 2(3): 1-11 25. celik c, gemalmaz d. comparison of marginal integrity of ceramic and composite veneer restorations luted with two different resin agents: an in vitro study. int j prosthodont 2002; 15: 59–64. dropbox rafeef.pdf simplify your life j bagh college dentistry vol. 29(4), december 2017 oral health status pedodontics, orthodontics and preventive dentistry 82 oral health status among kindergarten children in karbala city\iraq dhuha malik hassan, b.d.s. (1) baydaa hussien, b.d.s., m.sc. (2) abstract back ground: dental caries and periodontal disease followed by enamel defect were the most common and widely spread diseases affecting children. aim of this study is the assessment of the occurrence and severity of dental caries, dental plaque, gingivitis and enamel anomalies among 4-5 years old children in karbala city-iraq. materials and methods: a sample of 658 children (350 males, 308 females) aged four and five years old was selected randomly from the fourteenth kindergartens in karbala city. diagnosis and recording of dental caries and enamel anomalies were followed the criteria of who 1987, who1997 respectively. dental plaque was assessed using plaque index of silness and loe,1964. gingival health condition was assessed using gingival index of loe and silness, 1963. results: : caries prevalence was found to be 83% of the total sample. the mean rank value of dmfs was higher among boys in comparison to girls with statistically no significant difference(p>0.05). the value of dmfs increased with age with statistically highly significant difference (p<0.01). recording of this study demonstrated that 100% of children had dental plaque and gingival inflammation. the mean rank values of dental plaque and gingival indices for total boys were found to be higher than total girls with statistically highly significant differences (p<0.01). positive highly significant correlations were recorded between dental caries with dental plaque and gingival indices. in general, the percentage of enamel anomalies was found to be (39.8%). the mean rank values of any type of enamel defect were found to be higher among boys than girls with statistically significant differences (p<0.05). the most prevalent type of enamel defect was found to be hypoplasia followed by diffused opacities and then demarcated opacities. conclusion: high prevalence of dental caries and gingivitis was recorded indicating the need of public and preventive programs among kindergarten children. keywords: dental caries, oral hygiene, gingivitis, enamel defect and karbala city. (j bagh coll dentistry 2017; 29(4): 82-88) introduction dental caries is an irreversible infectious disease of the hard tissue of the tooth described by demineralization of inorganic portion and destruction of organic matter of the tooth lead to cavitation, it affects persons of every age group, in all races and both gender (1). dental caries is considered as a multifactorial disease of several factors, diet, microflora, host and time (2,3). the caries process can develop as soon as the tooth erupt in the oral cavity (4). high prevalence and severity of dental caries were reported in different geographical locations and in different age groups that conducted with previous epidemiological studies (5,6). the most common type of periodontal disease in children is gingivitis which may start early in life and increase in severity with age (7). gingivitis is a reversible condition, if it is not treated, it may progress later in life to periodontitis and if periodontitis developed, it may end with loss of teeth (8). previous epidemiological studies were conducted concerning the prevalence and severity of gingivitis and reported a high prevalence of gingivitis among different ages (6,9). (1) msc student, department of preventive dentistry, college of dentistry, university of baghdad. (2) assist professor, department of preventive dentistry, college of dentistry, university of baghdad. enamel defect is a disorder that may cause problems with teeth structure during the period of the enamel matrix formation (10), that clinically appeared in one or more of three forms; demarcated opacities (well bounded), diffuse opacities (have no boundaries) and hypoplasia (partially or complete lack of enamel surface)(11). in iraq, several studies were conducted among kindergarten children regarding the oral health status in different geographical areas (6,9). yet, no previous epidemiological study conducted among kindergarten children in karbala city in iraq, therefore, this study was designed and conducted. materials and methods this study was conducted among kindergarten children during the period between the middle of december (2015) till the end of march (2016) in karbala city, iraq. the sample consisted of kindergarten children aged four and five years old. the age was taken according to criteria of world health organization (11) according to last birthday. according to ministry of education, the estimated number of 4 and 5 years kindergarten children living in urban areas of karbala city/iraq was (3333) including (1765) males and (1568) females. the sample of this study consisted of (658) randomly selected kindergarten children (350) males and (308) females. j bagh college dentistry vol. 29(4), december 2017 oral health status pedodontics, orthodontics and preventive dentistry 83 in urban area of karbala, there were fourteen sections according to division of the general direction of education and in each section, there was one kindergarten, all the kindergartens were included in this study and from each kindergarten, 47 children were selected randomly (12). children who cooperative and without medical disease were included only. diagnosis and recording of dental caries was according to the criteria described by who (13). plaque index of silness and loe (14) was used for plaque assessment, gingival index of loe and silness (15) was followed for recording gingival health condition. enamel anomalies index of who (11) was used to assess enamel anomalies. the statisticwere used in this study mann-whitney, z-test and p-value. results table (1) illustrates the distribution of the total sample by age and gender. results showed that the prevalence of dental caries was (83%) for the total sample, total boys recorded a higher percentage of dental caries (84%) compared to total girls (81.8%). the children at 5 years were found with higher percentage of dental caries compared to boys at 4 years of age (table 2). table (3) describes caries experience (median, mean rank of ds, ms, fs, dmfs) among children by age and gender. dental caries was found to be higher in boys compared to girls in the total sample with statistically significant difference for the ds component (z=-1.981, mannwhitney=0.048, p<0.05), the mean rank values of dmfs for five years old boys and girls were higher than those values among boys and girls of four years old with statistically highly significant differences between them (z=-4.927, mannwhitney=0.001, p<0.01), (z=-3.288, mannwhitney=0.001, p<0.01) respectively. also, dental caries was higher at five years than at four years with statistically highly significant difference for the ds, ms and dmfs (z=-4.906,mannwhitney=0.001,p<0.01),(z=-5.163, mannwhitney=0.001,p<0.01),(z=-5.918,mann whitney=0.001, p<0.01) respectively. concerning plaque and gingival indices, the total boys were found with higher plaque and gingival indices than among total girls with statistically highly significant differences (z=4.063, mann-whitney=0.001,p<0.01), (z=3.507, mann-whitney=0.001, p<0.01) respectively. at five years old, the plaque and gingival indices were found to be higher than four years old with statistically no significant differences (p>0.05) as shown in table (4). the prevalence of gingival index was found to be 100%, the same result was reported with plaque index. the correlations between dental plaque and gingivitis with dental caries were positive and highly significant (p<0.01). a very positive strong and highly significant correlation was recorded between plaque and gingival indices (r=0.915, p<0.001). prevalence of enamel anomalies was (39.8%) of total sample (figure 1). furthermore, the enamel defect was higher among boys than girls for the all three types of defects with statistically significant differences for demarcated opacities (z=-2.007, mann-whitney=0.045, p<0.05) and hypoplasia (z=-2.506, mann-whitney=0.012, p<0.05) (table 5). for the total sample, the only three types of enamel defect were recorded. the most prevalent type was hypoplasia (22.2%) followed by diffused opacities (14.7) and demarcated opacities (9.9%) as showed in figure (2). table 1: the distribution of total sample by age and gender. gender age (year) total girls boys % no. % no. % no. 40.4 266 47.4 126 52.6 140 4 59.6 392 46.4 182 53.6 210 5 100 658 46.8 308 53.2 350 total table 2: prevalence of dental caries among children by age and gender. total girls boys age in year % no. % no. % no. 78.2 208 79.4 100 77.1 108 4 86.2 338 83.5 152 88.6 186 5 83.0 546 81.8 252 84.0 294 total j bagh college dentistry vol. 29(4), december 2017 oral health status pedodontics, orthodontics and preventive dentistry 84 table 3: caries experience (median, mean rank of ds, ms, fs, dmfs) among children by age and gender dmfs fs ms ds gender age in year mean rank median mean rank median mean rank median mean rank median 279.1 3 328.7 0 305.7 0 287.6 3 boys 4 273.6 4 324 0 300.9 0 283.3 4 girls 276.5 4 326.5 0 303.4 0 285.6 4 total 383.1** 10 330.3 0 348.8** 0 380.3** 8 boys 5 345.2** 8 333 0 345.4** 0 335.1* 6 girls 365.5** 9 331.6 0 347.2** 0 359.3** 8 total 341.5 8 329.6 0 331.5 0 343.2* 7 boys total 315.9 6 329.3 0 327.2 0 313.9 5 girls *significant p<0.05 **highly significant p<0.01 table 4: plaque and gingival indices among children (median and mean rank) by age and gender gi pli gender age (year) mean rank median mean rank median 354.2 o.666 360.1 0.583 boys 4 275.6 0.458 270.5 0.416 girls 317 0.541 317.7 0.5 total 353.6 0.683 356.1 0.583 boys 5 320* 0.562 316.1* 0.5 girls 338 0.625 337.5 0.5 total 353.9** 0.666 357.7** 0.583 boys total 301.8 0.521 297.4 0.458 girls *significant p<0.05 **highly significant p<0.01 figure 1: the distribution of children with enamel anomalies by age and gender. 0 5 10 15 20 25 30 35 40 45 50 49.3 29.4 39.8 41.4 37.9 39.8 44.6 34.4 39.8 p e rc e n ta g e o f s u b je c ts w it h a t le a s t o n e to o th w it h a n y d e g re e o f e n a m e l d e fe c t j bagh college dentistry vol. 29(4), december 2017 oral health status pedodontics, orthodontics and preventive dentistry 85 table 5: median and mean rank teeth with enamel anomalies by age and gender. type of defect gender age (year) hypoplasia diffused opacities demarcated opacities mean rank median mean rank median mean rank median 347.2 0 344.3 0 337.6 0 boy 4 300.6 0 331.5 0 317.7 0 girl 325.1 0 338.3 0 328.1 0 total 338.8 0 325.3 0 326.2 0 boy 5 325.2 0 321.6 0 323.8 0 girl 332.5 0 323.6 0 330.4 0 total 342.2* 0 332.9 0 336.7* 0 boys total 315.1 0 325.6 0 321.3 0 girls *significant p<0.05 figure 2: distribution of the sample according to types of enamel defect discussion the present study was designed to evaluate oral health status among kindergarten children in karbala city in iraq. the collected data are intended to be used as a data in evaluating the future efforts to improve oral health preventive program among preschool children in this country. the percentage of dental caries in the present study was 83% that it was higher than that recorded by previous studies (6,9) and lower than that reported by others (5,16). differences in dietary habits, oral hygiene measurements as well as dental health services among governorates in addition to differences in geographical location (17) may explain the variation in the caries prevalence between the present study and others. the relatively high prevalence of dental caries recorded in this study may be an indication of the poor preventive (6) and educational programs (5) in the studied area. in the present study, boys showed higher caries experience than girls for the total sample. the same finding was reported by previous studies (6,9). the variation between boys and girls in caries experience could be related to difference in oral cleanliness in the present study as a higher plaque index was recorded among boys. bacterial plaque is regarded essential for 0 10 20 30 40 50 60 70 60.2 9.9 14.7 22.2 p e rc e n ta g e o f s u b je c ts w it h a t le a s t o n e t o o th w it h a s [e c if ic ty p e o f e n a m e l d e fe c t j bagh college dentistry vol. 29(4), december 2017 oral health status pedodontics, orthodontics and preventive dentistry 86 the initiation of dental caries (16). the relation between dental caries and oral cleanliness (dental plaque) was reported also by previous iraqi study (6). the present study also reported the same correlation which was positive highly significant correlation. regarding age, caries experience was found to be higher among five years children than among four years children. the same result was reported by previous studies (6,9). this result could be attributed to accumulative and irreversible nature of dental caries (7). in this study, boys showed a higher plaque index than girls with statistically highly significant difference, the same result was reported by previous iraqi studies (6,9), while an opposite result was reported by jabber (18). this finding may be due to better oral hygiene among females rather than males because females are more oriented toward dental hygiene behavior like visiting the dentist and tooth brushing (6), however, this need to be confirmed in further studies regarding oral hygiene practices among children. concerning age, plaque index of 5 years old children was higher than that of 4 years old children. the same result was recorded by previous studies (5,19), while an opposite result was recorded by others (6,9), this could be explained by that older children feel more independent, and with inefficient tooth brushing (20)additionally, the amount of plaque accumulation in children varies in accordance to their tooth brushing (21) and diet (22), however, this need to be confirmed in further studies regarding oral hygiene practices and dietary analysis among kindergarten children. in this study, the prevalence of gingivitis was 100%, it was higher than that reported by previous studies (5,9), while the same result was reported by others (6,18). the high percentage of dental plaque (100%) could explain the high percentage of gingivitis (100%) as dental plaque is a prime inducer of gingivitis (23) and this is supported by the statistically positive highly significant correlation between dental plaque and gingivitis in the present study. the gingival index was higher among boys compared to girls. this result could be attributed to higher plaque index among boys than among girls. the same finding was reported in previous studies (5,9). concerning age, gingival index of 5 years old children was higher than that among 4 years old children. the same finding was reported by previous studies (5,6), while an opposite finding was reported by other study (9). the increase in gingivitis with advancing age could be explained by the increase in the amount of dental plaque with age and it was proven by different observational and experimental studies that dental plaque is the main cause of gingivitis (23) and both conditions get worse with age (24). in this study, the prevalence of enamel anomalies was 39.8% which was higher than that reported by previous studies (6,18), while it was lower than that found by other studies (25,26). it is important to mention that these studies differed in sample size, age of the group under study and location of the study. in the present study, the percentage of enamel defect was found to be higher among boys than girls. the same result was found in previous studies (6,27), while an opposite result was reported by others(18,28). definitive reason for this result is not documented but it may be partly explained by the inherent male vulnerability to stress, male on stressful environments would be expected to exhibit higher enamel anomalies than female (25). in the present study, hypoplasia was the most common type of enamel defects. the same finding was reported by previous studies (29,30). enamel hypoplasia is a defect in tooth result when matrix formation is affected, the quantity of enamel is less than normal. both quantity and quality of teeth may be affected (31). environmental stress (32), early childhood infectious disease and socio-economic status of the family have been associated with increased enamel defects in the primary teeth (33). furthermore, oxygen 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school children in heet city/alanbar governorate/iraq. master thesis, college of dentistry, university of baghdad, 2013. 27. robles mj, ruiz m, bravo-perez m, gonzalez e, penalver ma. prevalence of enamel defects in primary and permanent teeth in a group of school children from granada(spain). med oral patol cir bucal 2013; 18:e187-e193. 28. gatta e. primary teeth emergence and enamel anomalies in relation to nutritional status among 4-48 months old children in baghdad city\ iraq. master thesis, college of dentistry, university of baghdad, 2005. 29.al-janabi w. dental caries, enamel defect and malocclusion of primary dentition in relation to nutritional status among kindergarten children in hilla city. master thesis, college of dentistry, university of baghdad, 2008. 30.ferreira fv, ardenghi tm. developmental enamel defects and their impact on child oral health-related quality of life. braz oral res 2011, nov-dec; 25(6):531-537. 31.koch m, garcia-godoy f. the clinical performance of laboratory-fabricated crown placed on first permanent molars with developmental defects. jada. 2000; 131:1285-1290. 32. luckas jr, walimbe sr, floyed b. epidemiology, enamel hypoplasia in deciduous teeth: explaining variation in prevalence in western india. am j human biol 2001; 13:788-807. 33. chaves am, rosenblatt a, oliveira of. enamel defects and its relation to life course events in primary dentition of brazilian children: a longitudinal study. comm dent health 2007; 24:31-36. 34. beentjes ve, weerheijm kl, groen hj. factors involved in the etiology of molar-incisor hypominerilization (mih). eur j paediatr dent 2002; 3:9-13. j bagh college dentistry vol. 29(4), december 2017 oral health status pedodontics, orthodontics and preventive dentistry 88 حالة صحة الفم بين اطفال رياض االطفال في محافظة كربالء/العراق الخالصة تسوس االسنان وامراض اللثة تليها تشوهات المينا هي اكثر االمراض انتشارا وعلى نحو واسع تؤثر على االطفال.هدف المقدمة: البحث هو اجراء هذه الدراسة لحساب وجود وشدة تسوس االسنان, الصفيحة الجرثومية, التهاب اللثة وتشوهات المينا لالطفال بعمر العراق.-سنوات في مدينة كربالء 4-5 انثى( لالعمار اربعة و خمسة سنوات تم اختيارهم بصوره عشوائية 036ذكر , 053( طفل )856العينة تتكون من )المواد والطرق: من رياض االطفال الحكومية في محافظة كربالء المتكونة من اربعة عشر روضة. تشخيص وتسجيل تسوس االسنان وتشوهات المينا loe and على التوالي. الصفيحة الجرثومية تم تقييمها باستخدام 7881, 7861الصحة العالمية عام كان وفقا لمعايير منظمة silness) 7884(حالة صحة اللثة تم تسجيلها باستخدام . loe and silness (7880 .) ( كانت اعلى لدى dmfsاللبنية )من اجمالي العينة .قيمة مؤشر متوسط تسوس االسنان %60نسبة انتشار التسوس وجدت النتائج: ( تزداد مع االعمار مع وجود فروق dmfs(. قيمة )p>0.05مجموع الذكور مقارنة الى مجموع االناث مع عدم وجود فروق معنوية ) (.p<0.01معنوية عالية ) ع االناث مع وجود فروق قيم رتب متوسط الرقم القياسي للصفيحة الجرثومية والتهاب اللثة لمجموع الذكور كانت اعلى من مجمو من االطفال مصابين بترسبات االسنان والتهاب اللثة. لقد سجلت عالقة %733(. اظهر تسجيل هذه العينة بانه p<0.01معنوية عالية ) ايجابية وارتباط كبير للغاية بين التسوس, مؤشرات اللثة والصفيحة الجرثومية. يمة رتبة متوسط اي نوع من خلل المينا كان اعلى بين االطفال الذكور من االناث مع . وجد ان ق%08,6ان نسبة تشوهات المينا كانت (. النوع االكثر انتشارا من خلل المينا كان )نقص التنسج( تليها )عتامه منتشرة( ومن ثم )عتامه p<0.05وجود فروق معنوية) محدده(. ينا الحاجة الى برنامج وقائي وعام بين اطفال الروضة.لقد سجلت نسبة عالية من التسوس والتهاب اللثة مب االستنتاج: abdul-karim final.doc j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 1 the effect of various endodontic irrigants on the sealing ability of biodentine and other root perforation repair materials (in vitro study) ahmed k. al-zubaidi, b.d.s. (1) abdul karim j. al-azzawi, b.d.s., m.sc. (2) abstract background: this in vitro study was carried out to evaluate the effect of various endodontic irrigants (sodium hypochlorite, ethylene diaminetetracetic acid and normal saline) on sealing ability of (biodentine, mineral trioxide aggregate, and amalgam) used to repair furcal perforations. material and methods: one hundred and twenty extracted human molars with divergent roots were used in this study. a standard root canal access cavity was prepared in each tooth and furcal perforation was made and was standardized by using k file size 100 instrument to get a perforation of (1.32mm) in diameter .the teeth were randomly divided in to three groups of 40 teeth according to the type of material used to repair the perforations (group a: the furcal perforations were repaired with biodentine, group b: the furcal perforations were repaired with mta ,group c: the furcal perforations were repaired with amalgam). each group was then subdivided into 4 subgroups according to irrigation regimens applied over the repair site (subgroup 1: without irrigation, subgroup 2: the pulp chamber was gently irrigated with 10 ml 5.25% sodium hypochlorite for 10 minutes, subgroup 3: pulp chamber was gently irrigated with 10 ml 17% ethylene diaminetetracetic acid for 10 minutes, subgroup 4: pulp chamber was gently irrigated with 10 ml normal saline for 10 minutes. each tooth was coated with two layers of nail varnish and then sticky wax except 1 to 2 mm around the perforation site. each tooth was placed in glass vial containing 3 ml of buffered methylene blue dye at (37°c, ph 7) and kept in an incubator for 72 hour at 100% humidity. after dye application, the teeth were washed in running water for 5 min. each tooth was sectioned longitudinally in a buccolingual direction. results: the results showed that group a has least mean of dye penetration and the difference was highly significant with group c and non-significant with group b.saline and naocl increase the sealing of all groups while edta significantly increased the dye penetration of biodentine and mta respectively. conclusions: biodentine has the best sealing ability of the tested materials while amalgam showed the highest dye penetration of all tested materials. saline and naocl increase the sealing ability of biodentine and mta where as edta decreased the sealing efficacy of mta and biodentine. keywords: biodentine, mta, edta, naocl, root perforations. (j bagh coll dentistry 2014; 26(3):1-8). الخالصة على قدرة الختم ) ول الھایبوكلوراید و المحلول الملحي العادي محل, اسد كمحلول االثیلین دایمین تیترا است(ل قنوات الجذور ة لغسالھدف من ھذه الدراسة كان لتقییم تأثیر مواد مختلف .مفترق الجذور ثقبالمستعملة في ترمیم ) مادة تجمع المعدن ثالثي االوكسد و االملكم , البایودنتین (لمواد ذر و تم معایرتة بحیث یصبح جذر القیاسیة لكل سن ثم عمل انثقاب لمفترق التم تحضیر قناه الج.متباعدة الجذور , سفلیة حدیثة القلع ضرساستخدمت في ھذه الدراسة مئة و عشرون استنادا لنوع المادة المستعملة في ترمیم انثقاب عشوائیا الى ثالت مجموعات تحوي على اربعین رحى االضراسقسمت , 100مقیاس kبواسطة استخدام مبرد ) ملم 1,32(بقطر :كاالتي مفترق الجذر .رممت انثقابات الجذور بمادة البایودنتین : مجموعة أ .رممت انثقابات الجذور بمادة تجمع المعدن ثالثي االوكسد : مجموعة ب م غرممت انثقابات الجذور بمادة االمل: مجموعة ج :ذور على النحو التاليمجموعات فرعیة وفقا لنظم الري التي تم تطبیقھا على موقع إصالح مفترق الج 4م تم تقسیم كل مجموعة إلى ث .لم یجري أي ري : المجموعة الفرعیة االولى .دقائق 10٪ لمدة 5.25مل من محلول الھایبوكلوراید 10تم ري غرفة اللب بلطف مع : المجموعة الفرعیة الثانیة دقائق 10اسد لمدة كمل من محلول االثیلین دایمین تیترا است 10تم ري غرفة اللب ب :المجموعة الفرعیة الثالثة دقائق 10لمدة متعادلمل من محلول الملحي ال 10تم ري غرفة اللب ب : المجموعة الفرعیة الرابعة ملم 21لالصق باستثناء كل سن تم تغطیتھ بواسطة طبقتین من مادة طالء االظافر تلیھا طبقة من الشمع ا. االسنان بالحشوة المؤقتة ملئتساعة ثم 24تركت جمیع األسنان لتجف لمدة .حول موقع انثقاب مفترق الجذور ساعة وبعد تطبیق 72و حفظ في حاضنة لمدة ) 7درجة مئویة، ودرجة الحموضة 37(زرقاء مخزنة في المل من صبغة المیثیلین 3وضع كل سن في قارورة زجاجیة تحتوي على تم قطع كل رحى طولیا على طول المحور الطولي في االتجاه الدھلیزي اللساني من خالل االنثقاب باستخدام القرص . ق دقائ 5الصبغة، تم غسل األسنان في المیاه الجاریة لمدة نوي احصائي عال جدا مع الف ذو فرق معاظھرت النتائج ان المجموعة االولى المرممة بمادة البایودنتین كان لھا القیمة الوسطیة النسبیة االوطا الختراق الصبغة و كان االخت. الماسي .د غیر معنوي المجموعة الثالثة المرممة بواسطة مادة االملكم و كان الفرق بین المجموعة االولى و الثانیة المرممة بمادة تجمع المعدن ثالثي االوكس زیادة سبب في في حین محلول محلول االثیلین دایمین تیترا استل اسد جموعات جمیع المكما اظھرت النتائج ان المحلول الملحي العادي و و محلول الھایبوكلورایت یزید قابلیة الختم .كبیرة في اختراق الصبغة من البایودنتین و مادة و تجمع المعدن ثالثي االوكسد على التوالي introduction an unfortunate but common complication of access preparation for endodontic therapy is a perforation made through the root into the surrounding periodontal tissues. the perforation (1) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. normally occurs in the cervical area of anterior teeth, or in the furcation area of posterior teeth, as a result of the length of the bur being used (1). delay of perforation repair can cause microbial contamination of the defect and breakdown of the periodontium, resulting in endoperiodontal lesions that are difficult to manage. as such, perforation defects should be j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 2 repaired before proceeding with definitive endodontic treatment (2). despite the numerous favorable properties of mta that support its clinical use when compared with the traditional materials, there are several critical drawbacks such as the prolonged setting time, difficult handling characteristics, high cost, and potential of discoloration (3). a variety of new calcium silicate–based materials have been developed recently aiming to improve mta shortcomings. biodentine (septodont, saint maur des foss_es, france) is a high-purity calcium silicate– based dental material that is recommended for use as a dentin substitute under resin composite restorations and an endodontic repair material because of its good sealing ability, high compressive strengths, short setting time,biocompatibility, bioactivity, and biomineralization properties (3),following the repair of furcal perforations, endodontic treatment should be performed with various irrigation solutions such as edta and naocl to clean the root canal system. this procedure causes inevitable contact of endodontic irrigants with the site of furcal repair in contrast to the welldocumented chemical and morphological effects of routinely used irrigants (e.g., sodium hypochlorite [naocl] and ethylene diamine tetraacetic acid [edta]) on root dentin and smear layer (4). a little information exists with regard to the influence of these solutions on the integrity and sealing properties of repaired furcal perforations.the purpose of this in vitro study was to determine and compare the effect of various root canal irrigants (sodium hypochlorite, ethylene diamine tetraacitic acid, and normal saline) on sealing ability of three different furcal perforation repair materials (biodentine, mineral trioxide aggregate, and amalgam). materials and methods selection of the samples one hundred and twenty freshly extracted mandibular molars were used in the present study. the cause of extraction, age and gender were not considered. the molars were collected according to the following criteria: complete root formation, minimal occlusal or no caries, with diverged roots and no cracks on examination with 10x magnifying eye lens and light cure device (5,32). after extraction, the teeth were cleaned by immersion in a 5.25% solution of sodium hypochlorite for 30 min. soft tissue tags and calculus were removed by cumine scaler. teeth were then washed with tap water and stored in normal saline until use (6). to facilitate manipulation, the teeth were decoronated 3 mm coronal the cemento-enamel junction and the roots were amputated 3 mm apical the furcation using a diamond disk (2). preparation of the samples all the teeth were prepared as following: a standard root canal access cavity was prepared in each tooth with a number 4 round bur in a highspeed handpiece with water spray for the initial entry followed by endo-z bur (long tapered configuration bur that allow easy access to the canal orifices and funnel shaping of the chamber walls) for lateral extension and finishing of cavity walls. the contents of the pulp chamber and root canals were removed with a spoon excavator and barbed broaches, respectively (2). creation of the artificial perforations a heavy addition silicone impression material (express std 3m espe, dental products) was mixed according to the manufacturer instructions and placed in the area of artificial teeth of the manikin to provide a matrix that simulated the bony socket as it serves as a jaw for the teeth and was similar to barrier when condensing repair materials into perforation area.the molars were placed into the unset silicone impression material and then removed after complete polymerization of the material (7). artificial perforations were created in the center of the pulp chamber floor by using a size 2 round diamond bur (100 iso size; dentsply maillefer, ballaigues, switzerland) in a low-speed handpiece. the bur used for making a perforation was renewed every 5 samples. then #100 k file was used to enlarge the perforation size so that the d16 facing the bottom of perforation to get standardized perforation diameter 1.32 mm at d16 of #100. the pulp chamber was filled with distal water for 3 minutes before being dried. paper points were used to remove excess moisture within the perforation before repair (8). for standardization, the heights of the walls of the perforated area in all the samples was 2mm which measured by using a periodontal probe. the samples in which the thickness of dentin at the perforated area was less than 2 mm were excluded (9). sample grouping one hundred and twenty mandibular molars were randomly divided into three groups (n =40) according to the material used for repairing the perforation defects: (group a:in which the perforations were repaired with biodentine, group b:in which the perforations were repaired j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 3 with mta, group c: in which the perforations were repaired with amalgam). all the restorative materials used in this study were mixed according to the manufacturer’s recommendations for each restorative material, the specimens were further divided randomly into 4 groups (n=10 each) according to irrigation regimens applied over the repair site (10) (subgroup 1: without irrigation, subgroup 2: the pulp chamber was gently irrigated with 10 ml 5.25% naocl and left for 10 minutes using disposable syringe, subgroup 3: pulp chamber was gently irrigated with 10 ml 17% edta and left for 10 minutes using disposable syringe, subgroup 4: pulp chamber was gently irrigated with 10 ml normal saline and left for 10 minutes using disposable syringe. one investigator performed all procedures. in subgroups 2, 3, and 4, the cavities were gently irrigated with 10 ml distilled water after irrigation of the tested solutions' to neutralize the prolonged effect of irrigants (2). all the teeth were left to dry for 24 hour and all the access cavities were filled with temporary filling material. leakage study each tooth was coated with two layers of nail varnish except 1-2 mm around perforation and then sticky wax was melted in a cauldron and the roots were dipped in it by holding tooth with endodontic spreader to achieve a noticeable waxcovering of the apical and lateral portions of the roots, but avoiding wax coverage on the 1 to 2 mm around the perforation site and was left to dry.this will give complete sealing of the tooth (8). after storage for 24 hours in incubator, each tooth was placed in glass vial containing 3 ml of methylene blue dye at (37°c, & ph 7) and kept in incubator for 72 hour at 100% humidity.after dye application; the teeth were washed in running water for 5 min. the sticky wax and nail varnish were scrapped from the tooth with lacron carver and washed again under running water for 30 min. then the teeth were left to dry at room temperature for 24 hours (8). to evaluate the depth of dye penetration, each tooth was sectioned longitudinally in a in buccolingual direction, which was approximately parallel to the long axis of the tooth and through repaired perforation using diamond disk (0.3 thickness). each half was fixed on a glass slide with sticky wax and each root given a special number so that data collection became easier (11). linear dye penetration was measured using a stereomicroscope with a 0.1-mm ocular grid at 20x magnification by using a millimeter grid digital vernier. the extension of dye penetration between the furcation filling material and tooth structure along bifurcation was assessed by two examiners calibrated for the technique and blinded to the groups. the measurement was made from bifurcation to the point where the dye no longer penetrated between the filling material and dentinal wall on both halves of each tooth. accordingly, four leakage measurements were obtained for each specimen. the highest leakage values per specimen attributed by theexaminers were selected and micro-leakage means recorded for the experimental groups (11). results the results of the descriptive statistics which include the minimum, maximum, mean, and standard deviation values offurcal microleakage for three types of root perforation material using different types of root canal irrigants are shown in table (1). table (1) and figure (1) showed the following: the lowest mean value of furcal dye penetration in teeth repaired by biodentine group (a) was found in subgroup a4 while the highest mean value of furcal dye penetration was seen in subgroup a3, the rest mean values for study subgroups were fluctuating between these values . the highest mean value of furcal dye penetration in mta group (b) was seen in subgroup b3 while the lowest mean value of furcal dye penetration was found in subgroup b4.the lowest mean value of furcal dye penetration in teeth repaired with amalgam group (c) was found in subgroup c4 while the highest mean value of furcal dye penetration was seen in subgroup c3. anova test was performed to identify the presence of statistically significant differences for each type of material among different irrigant subgroup. the result showed highly significant differences in group a and group b regarding different irrigant solutions (naocl, edta and saline) while no significant differences were seen in group c as seen in table (2) the least significant difference test (lsd) was performed to evaluate the significant differences between different irrigant subgroup for each type of material and the result listed in table (3). table (3) showed that: 1. there was a significant difference between subgroup a1 and subgroup a2 while there was a highly significant difference between subgroup a1 and subgroup a3 and between subgroup a1 and subgroup a4. 2. there was highly significant difference between subgroup a2 and subgroup a3 and between subgroup a4 and subgroup a3 while no j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 4 significant difference between subgroup a2 and subgroup a4. 3. there was a highly significant difference between subgroup b1 in which teeth repaired with mta without irrigation and subgroup b3 in which mta irrigated with edta while there was significant difference between subgroup b1 and subgroup b2 when mta irrigated with naocl and between subgroup b2 and subgroup b4 when mta irrigated with normal saline. 4) there was a highly significant difference between subgroup b2 and subgroup b3 and between subgroup b4 and subgroup b3 while there were no significant difference between subgroupb2 and subgroup b4. table 1: descriptive statistics groups subgroups mean ±s.d. a (biodentine) a1 (without) 0.37 0.08 a2 (naocl) 0.28 0.08 a3 (edta) 0.61 0.14 a4 (saline) 0.25 0.05 b (mta) b1 (without) 0.42 0.09 b2 (naocl) 0.37 0.08 b3 (edta) 1.08 0.24 b4 (saline) 0.31 0.09 c (amalgam) c1 (without) 1.71 0.26 c2 (naocl) 1.65 0.23 c3 (edta) 1.75 0.16 c4 (saline) 1.64 0.26 table 2: anova test for furcal dye penetration among different irrigant within each type of material groups sum of squares mean square f-test p-value a 0.8 0.27 30.8 0.000 (hs) 0.31 0.01 1.11 b 3.88 1.29 62.7 0.000 (hs) 0.74 0.02 4.62 c 0.08 0.03 0.5 0.682 (ns) 1.92 0.05 2 p≥ 0.05= n.s (non-significant), p ≥ 0.05≥ 0.01 =s (significant), p≤ 0.01=highly significant (hs) table 3: lsd test for furcal dye penetration among different irrigant for each type of material materials irrigants mean difference p-value a (biodentine) a1 a2 0.09 0.037 (s) a3 -0.24 0.000 (hs) a4 0.12 0.007 (hs) a2 a 3 -0.33 0.000 (hs) a4 0.03 0.475 (ns) a3 a4 0.36 0.000 (hs) b (mta) b1 b2 0.05 0.041 (s) b3 -0.66 0.000 (hs) b4 0.11 0.095 (s) b2 b 3 -0.71 0.000 (hs) b4 0.06 0.356 (ns) b3 b4 0.77 0.000 (hs) evaluation of furcal dye penetration among different group of materials for each type of irrigant was done using anova test (table 4) which revealed the presence of highly significant differences. least significant difference (lsd) test was performed to find source of significance table (5). the result of lsd test showed: 1) there was a highly significant difference between group (a) in which perforations repaired by biodentine and group (c) when amalgam used to seal the perforations and between group (b) in which perforation repaired with mta and group (c) while that there were a no significant difference between group (a) and group (b) when no irrigation used. 2) there was a no significant difference between group (a) and group (b) while there were a highly significant difference between group (a) and group (c) and between group (b) and group (c) when naocl used. 3) there was a highly significant difference between all groups of material when edta used. 4) there was a highly significant difference between group (a) and group (c) and between group (b) and group (c) while that there were a no significant difference between group (a) and group (b) when normal saline used . figure 1: mean of furcal dye penetration of different materials using different irrigants j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 5 table 4: anova test for furcal dye penetration among different groups of materials within each type of irrigant irrigants sum of squares mean square f-test p-value 1 (without irrigation) 11.54 5.77 208.85 0.000 (hs) 0.75 0.03 12.29 2 (naocl) 11.74 5.87 263.38 0.000 (hs) 0.6 0.02 12.35 3 (edta) 6.56 3.28 95.29 0.000 (hs) 0.93 0.03 7.49 4 (normal saline) 12.35 6.17 238.84 0.000 (hs) 0.7 0.03 13.05 table 5: lsd test for furcal dye penetration among different groups of material within each type of irrigant irrigants materials mean difference p-value 1 (without irrigation) a1 b1 -0.05 0.507 (ns) c1 -1.34 0.000 (hs) b1 c 1 -1.29 0.000 (hs) 2 (naocl) a2 b2 -0.09 0.189 (ns) c2 -1.37 0.000 (hs) b2 c2 -1.28 0.000 (hs) 3 (edta) a3 b3 -0.47 0.000 (hs) c3 -1.14 0.000 (hs) b3 c3 -0.67 0.000 (hs) 4 (normal saline) a4 b4 -0.06 0.411 (ns) c4 -1.39 0.000 (hs) b4 c4 -1.33 0.000 (hs) discussion perforations are procedural accidents that can have an adverse effect on the outcome of endodontic treatment. identification of root perforations is possible by diagnostic aids that include direct observation of bleeding, indirect bleeding assessment using a paper point, radiography and an apex locator (12). dye penetration technique has been used in this study because of its ease of performance as compared to other available techniques. however, the dye penetration method is said to have certain drawbacks including the smaller molecular size of the dye molecules than bacteria, which do not measure the actual volume absorbed by the sample but merely measure the deepest point reached by the dye. it relies on randomly cutting the roots into two pieces, without any clue of the position of the deepest dye penetration (13). despite these drawbacks, a material that is able to prevent the penetration of small molecules (dye) should be able to prevent larger substances like bacteria and their byproducts (12). based on this, dye penetration seems to be a reliable technique and thus 2% methylene blue dye was used in the present study. effects of different materials on sealing ability of furcal perforation: the result of the present study showed the least mean value of the furcal dye penetration were found in group (a) and when compared with other groups, there was highly significant difference between group (a) biodentine and group (c) that used amalgam to repair perforation, while no significant difference between group (a) and group (b) that used mta material .these results are in agreement with koate and pawar and koubi et al. (14,15). this could be attributed to: the superior ability of the calcium silicate materials to form hydroxyapatite crystals at the interface between the restorative material and the dentin walls, these crystals may contribute to the sealing efficiency of the material. just after mixing, the calcium silicate particles of biodentine, like all calcium silicate materials, react with water to form a high-ph solution containing ca2+, oh−, and silicate ions. in the saturated layer, the calcium silicate hydrate gel precipitates on the cement particles, whereas calcium hydroxide nucleates (16-18).also the small size of forming gels may contribute to better spreading of the material onto the surface and better fitting to dentin walls; a slight expansion of the calcium silicate-based materials may also explain the good sealing qualities of the calcium silicate cement (19).this finding disagree with the study done by sanghavi et al.; this could be due to :1. different method used by the researcher where a larger perforation (2mm) in width he made in his study while in this study the perforation width was (1.32 mm) in width which made it difficult to seal the defect effectively. 2. the researcher used proroot mta while in this study, mta angelus was used which has different composition. mta-angelus does not contain calcium sulfate and has lower percentage of bismuth oxide. this caused a reduction of the setting time from 2 hours for proroot mta to 10 minutes for mta-angelus (21) in this study the results also show that group (b1) in which perforations repaired with mta have significantly higher difference than group (c1) that used amalgam for repair this coincide with finding of (14,22). this could be attributed to: water based cements have been demonstrated good performance to seal the furcal perforation when compared to other materials. this moisture j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 6 has favorable effect for mta and biodentine because of being water based materials has the ability to set in the presence of moisture while this moisture has a negative effect on amalgam which requires a dry field for good properties and that’s difficult to obtain clinically (23).the main constituents of this material are calcium silicate, bismuth oxide, calcium carbonate, calcium sulfate, and calcium aluminate. hydration of the powder produces a colloidal gel that solidifies into a hard structure consisting of discrete crystals in an amorphous matrix (24). the result of the study also showed that amalgam has higher furcal dye penetration and there was a significant difference with group (a) and group (b) and this due to the defect were bottomless so the amalgam cant be well condensed to the perforation to provide the adequate seal and the amalgam is bonded mechanically and there is no chemical bonding between the amalgam and the opened dentinal tubules (25). effect of different endodontic irrigation solutions 1. effects of edta the results of this study indicated that there was a highly significant difference between subgroup a3 and subgroup a1 and subgroup b3 and subgroup b1. this finding is in accordance with other studies (2,26). these results can be explained: 1) as ph decreases, the leakage of mta increases owing to the acidic ph, the solubility of these repair materials may increase, which, in turn, might adversely affect their sealing ability. moreover, calciumdepleting irrigants (edta) are capable of dissolving the smear layer rapidly (in this particular case, the smear layer on the inner surface of bur-cut perforation), and infiltrate into the interfacial layer; where they can interfere with the chemical adhesion between repair materials and dentin. indeed, decomposition of particle-binding hydration phases by acid treatment raises potential concern on the strength and sealing properties of mtarepaired perforations following irrigation by edta. as known, the hydration phases are responsible for the strength and barrier properties of mta (27,28). 2) another explanation could be the demineralization effect of edta on cacontaining materials. because of the porous nature of mta, it was conceivable that this precipitation proceeded internally within mta to change the microstructure of mta and thus led to a significant decrease in bond strengths of mtadentin which in turn reduce sealing ability (29,31). the result also showed that there was a highly significant difference between subgroup a3 in which perforation repaired with biodentine and subgroup b3 in which mta used to repair perforation. this finding agrees with popali et al. this can be explained on the basis of calcium chloride present in the biodentine liquid that’s supplied by the manufacture .the addition of cacl2 is intended to reduce the setting time and improve physiochemical properties by its ability to penetrate the pore of the cement, strongly accelerating the haydration of the silicate and leading to their faster crystallization (30). effects of naocl the results of this study showed increase in the sealing of biodentine when irrigated with naocl subgroup a2 when compared with subgroup a1 in which perforation repaired with biodentine with no irrigation used and the difference were significant.this could be due to: 1)when biodentine was exposed to naocl, it increased the size and amount of calcium hydroxide crystals compared with the control group, release of calcium, production of calcium hydroxide and increasing the ph all play apart in increase the sealing of the material (3). 2) the biomineralization ability of biodentine, most likely through the formation of tags, ion uptake into dentin leading to the formation of tag-like structures in biodentine was higher than in mta(3). 3) naocl has an alkaline ph of 9.0 10.5, the literature indicated that high ph environments may enhance various physical and chemical properties of calcium silicate material (2). the results also showed increase in the sealing of subgroupb2 in which mta where used for repair and irrigated with naocl when compared to subgroup b1 in which no irrigation used but the difference were not significant. these results were in coincide with uyanik et al. and this can be explained by: naocl is a halogenated compound that can cause mineral accumulation in human root dentin and expose inorganic material which may prevent dentin dissolution or may leave a smear layer of mineralized tissue that could increase the calcium /phosphate ratio of the dentin surface. effects of normal saline the results of this study indicate that there were a highly significant difference between subgroup a4 and subgroup a1 in which no irrigation used; this could be attributed by: 1) when biodentine exposed to saline one may speculate that additional unreacted mineral oxides may have remained that, once additional j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 7 hydration was supplied, solidified and further increased the strength of the material. 2) different chemical composition of biodentine which contain calcium chloride in the liquid. the addition of cacl2 reduce the setting time and improve physiochemical properties by its ability to penetrate the pore of the cement, strongly accelerating the hydration of the silicate, reduce the incorporation of water, allow the cement to resist hydrostatic pressure, even at early stages, therefore avoiding the leakaging of cement and leading to their faster crystallization. when saline used to irrigate mta repaired perforation, the sealing increased but the difference was significant when compared with control group in which no irrigation used. this result agrees with other studies (1,3); this may be due to of the remaining unreacted mineral oxides which may be solidified after additional supplied hydration and may result in the increased strength of the material. references 1. loxley ec, liewehr fr, buxton tb, mcpherson jc 3rd. the effect of various intracanal oxidizing agents on the push-out strength of various perforation repair materials. oral surg oral med oral pathol oral radiol endod 2003; 95: 490–4. 2. uyanik mo, nagas e, sahin c, dagli f, cehreli zc. effects of different irrigation regimens on the sealing properties of repaired furcal perforations. oral surg oral med oral pathol oral radiol endod 2009; 107: e91–5. 3. guneser mb, akbulut mb, eldeniz au. effect of various endodontic irrigants on the push-out bond strength of biodentine and conventional root perforation repair materials. j endod 2013;39: 380-4 4. torabinejad m, cho y, khademi aa, bakland lk, shabahang s. the effect of various concentrations of sodium hypochlorite on the ability of mtad to remove smear layer. j endod 2003; 29: 233–9 5. hashem a, amin s. the effect of acidity on dislodgment resistance of mineral trioxide aggregate and bioaggregate in furcation perforations: an in vitro comparative study. j endod 2012; 38(2): 245-9 . 6. zou l, liu j, yin s, li w, xie j. in vitro evaluation of the sealing ability of mta used for repair of furcation perforation with and without the use of internal matrix. oral surg oral med oral path endod 2008;105(6): 615. 7. el-tawil sh, el-dokky n, el-hamid d. sealing ability of mta versus portland cement in the repair of furcal perforations of primary molars: a dye extraction leakage model. j am sci 2011; 7(12):1037-43 8. alaajam w. evaluation of the sealing abilities of different materials used to repair furcal perforations (in vitro study). a master thesis college of dentistry, university of baghdad, 2002. 9. rahimi s, ghasemi n, shahi s, lotfi m, froughreyhani m, milani a, bahari m. effect of blood contamination on the retention characteristics of two endodontic biomaterials in simulated furcation perforations. j endod 2013; 39(5): 697-700. 10. zaparolli d, saquy p, cruz-filho a. effect of sodium hypochlorite and edta irrigation, individually and in alternation, on dentin microhardness at the furcation area of mandibular molars. braz dent j 2012; 23(6): 654-8. 11. amin b, dayem r, salman r. the effect of two demineralizing agents on apical sealing of retrograde filling materials (in vitro study). must dent j 2009; 6(4): 299-306. 12. reddy d, kommineni n, kumar, hemadri m, prasad s. comparative evaluation of sealability of different root canal perforation repair materials by using a dyeextraction leakage method (an in virto study). indian j dental sci 2013; 5(4): 44. 13. camps j, pashley dh. reliability of the dye penetration studies. j endod 2003; 29: 592– 4. 14. kokate s, pawar a. an in vitro comparative stereomicroscopic evaluation of marginal seal between mta, glass inomer cement & biodentine as root end filling materials using 1% methylene blue as tracer. endodontology 2012; 24(2): 36-42. 15. koubi s, elmerini h, koubi g, tassery h, camps j. quantitative evaluation by glucose diffusion of microleakage in aged calcium silicate-based opensandwich restorations. int j dent 2012: 105863. 16. pellenq rjm, kushima a, shahsavari r, et al. a realistic molecular model of cement hydrates. proceedings of the national academy of sciences of the united states of america. 2009; 106(38): 16102-7. 17. gandolfi mg, van landuyt k, taddei p, modena e, van meerbeek b, prati c. environmental scanning electron microscopy connected with energy dispersive x-ray analysis and raman techniques to study proroot mineral trioxide aggregate and calcium silicate cements in wet conditions and in real time. j endod 2010; 36(5): 851–7. 18. kinner lb, chae sr, benmore cj, wenk hr, monteiro pjm. nanostructure of calcium silicate hydrates in cements. physical review letters. 2010; 104(19): 195502. 19. gandolfi mg, ciapetti g, perut f, taddei p, modena e, rossi pl, prati c. biomimetic calcium-silicate cements aged in simulated body solutions. osteoblast response and analyses of apatite coating. j appl biomater biomech 2009; 7(3): 160–70. 20. sanghavi t, shah n, shah r. comparative analysis of sealing ability of biodentin and calcium phosphate cement against mineral trioxide aggregate (mta) as a furcal perforation repair material (an in vitro study). njirm 2013; 4(3): 56-60. 21. sluyk sr, moon pc, hartwell gr. evaluation of the setting properties and retention characteristics of mineral trioxide aggregate when used as a furcation perforation repair material. j endod 1998; 24: 768-71. 22. pereira cl, cenci ms, demarco ff. sealing ability of mta, super eba, vitremer and amalgam as root-end filling materials. braz oral res 2004; 18: 317–21. 23. torabinejad m, smith pw, kettering jd, pittford tr. comparative investigation of marginal adaptation of mta and other commonly used root end filling material. j endod 1995; 21: 295-6. 24. tsatsas dv, meliou ha, kerezoudis np. sealing effectiveness of materials used in furcation perforation in vitro. int dent j 2005; 55: 133-41. j bagh college dentistry vol. 26(3), september 2014 the effect of various restorative dentistry 8 25. ahangari z, karami m. evaluation of the sealing ability of amalgam, mta, portland cement and coltozol in the repair of furcal perforations. iran endod j 2006; 1(2): 60–4. 26. popali g, jadhav s, hedge v. effects of acid environment on surface microhardness of biodentine. world j dent 2013; 4(2): 100-2. 27. roy co, jeansonne bg, gerrets t. effect of an acid environment on leakage of root-end filling materials. j endod 2001; 27: 7-8. 28. lee yl, lin fh, wang wh, ritchie hh, lan wh, lin cp. effects of edta on the hydration mechanism of mineral trioxide aggregate. j dent res 2007; 86: 534-8 29. yan p, peng b, fan b, fan m, bian z. the effects of sodium hypochlorite (5.25%), chlorhexidine (2%), and glyde file prep on the bond strength of mtadentin. j endod 2006; 32: 58-60. 30. hong st, bae ks, baek sh, kum ky, shon wj, lee w. effects of root canal irrigants on the push-out strength and hydration behavior of accelerated mineral trioxide aggregate in its early setting phase. j endod 2010; 36: 1995–9. 31. al-aubaydi a, aziz a. effect of edta on apical leakage of resin based root canal sealer. j bagh college dentistry 2010; 22 (4):10-4. 32. al-jaff a, al-azzawi h. comparison of bond strength in different levels of post space of fiber-reinforced post luted with different resin cements. j bagh coll dentistry 2011; 23(3): 1-5. suha f.doc j bagh college dentistry vol. 27(3), september 2015 dental caries pedodontics, orthodontics and preventive dentistry165 dental caries among kindergarten children in relation to socioeconomic status in al-najaf governorate-iraq suha m. shubber, b.d.s. (1) wesal a. al-obaidi, b.d.s., m.sc. (2) abstract background: dental caries is the most common oral problem, although dental caries is not life threatening, it has a harmful effect on quality of life. socioeconomic factors were found to be strong predictors of the prevalence of oral diseases in children, likes family income, occupational prestige, and education. the aim of this study is to assess the effect of socioeconomic factors on occurrence dental caries in their children. materials and methods: the sample consists of 550 kindergartens children aged between (4-5) years were selected randomly, girls and boys. the kindergartens selection was randomly from different geographical areas in al-najaf governorate. information was taken from children's parents using questionnaire with the help of the kindergartens managers. examination of dental caries severity was performed according to the world health organization (1987). children were examined in a suitable room in their school. day light was used for illumination. results: high caries prevalence was recorded (84.7%); females had higher caries prevalence as compared to males. mean dmfs was (10.05±0.40) and ds value was the highest component. age differences were recorded for both indicators with no gender differences. secondary and high schools are the highest percentage of the education of the child’s parents and the differences were not significant regarding dental caries between parent factors. conclusion: children in this study were in need of preventive programs that are to say in need of recall for regular visits and the prophylactic application of fluoride therapy and fissure sealant to prevent initiation of dental caries. key words: dental caries, children, socioeconomic status. (j bagh coll dentistry 2015; 27(3):165-168) introduction dental caries is a localized, progressive destructive, largely irreversible microbial based disease, affecting the calcified tissue of the teeth characterized by dissolving in the tooth minerals demineralization and destruction of the organic portion leading to tooth cavitation (1). it may start early and if not treated progression to tooth loss could be suspected (2). dental caries considered as a multifactorial disease depending on interaction of several factors, oral microflora, diet, host and time (3). associations between socioeconomic status (ses) and health are so pervasive that some have designated ses as a fundamental cause of health and illness includes dental caries (4). it is widely acknowledged that the behavior of parents, particularly mothers, affects their children's health (5,6), because they are the main caregivers of oral health to their children during the first three years of life, even in preschool; parents are still the main supplier of children's oral health(7). some factors such as maternal education, occupation, age, current knowledge, attitude, and behavior can provide insight for improving their health habits and their children's health indirectly (8). (1)master student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2)professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. materials and methods this oral health survey was conducted among kindergartens children aged between (4-5) years living in center andtownship areas in al-najaf governorate, iraq. the kindergartens selection was randomly from different geographical areas in alnajaf governorate. al-najaf city was divided into three sectors, these sectors are: al-najaf, al-kufa and almanathera. prior to oral examinations, the following information regarding ses was taken from the parents of the children using questionnaire, the information include: 1. parent’s education was divided into 4 levels: • score 1: illiterate (neither read nor writes). • score 2: who finished primary schools. • score 3: who finished secondary and high schools. • score 4: who finished college and beyond college organization (diploma, msc, ph.d.). 2. job of the mother, the criteria was divided into two categories: • score 1: house keeper. • score 2: worker. 3. age of the mother 4. if mother and/or the father alive it was divided into four categories: • score 1: mother and father alive. • score 2: mother alive and father dead. • score 3: mother dead and father alive. • score 4: mother and father dead. j bagh college dentistry vol. 27(3), september 2015 dental caries pedodontics, orthodontics and preventive dentistry166 clinical examinations were performed using plane mouth dental mirrors and explorers. examinations included all surfaces of teeth. a tooth was considered to be present when any part of the tooth was visible. an alphabetical coding system was applied for primary, (who, 1987). carious lesions were recorded for all surfaces of the teeth involved. missing teeth were counted as five surfaces for posterior and four surfaces for anterior teeth. retained roots were counted as a five decayed surfaces for posterior and four decayed surfaces for anterior teeth. temporary crowns were recorded as five decayed surfaces for posterior and four decayed surfaces for anterior teeth. data entering and analysis were performed using statistical package for social science spss for windows statistical software package version 19.0. the statistical tests which were used are: student t-test and anova test. results the distribution of the total sample by age and gender, were show in table (1). this table shows that the number of four years is more than five years and the numbers of females are slightly more than males. table (2) illustrates cariesseverity in deciduous teeth (dmfs) among children. females were found to have higher dmfs mean value than males; this difference was found to be statistically not significant at p< 0.05. table 1: distribution of kindergartens children by age and gender age/years males females total no. % no. % no. % 4 144 49 .3 148 50.7 292 53.1 5 126 48.8 132 51.2 258 46.9 total 270 49.1 280 50.9 550 100.0 table 2: dental caries severity (dmfs) by gender age sex no. dmfs mean ± se student's t-test p 4 years males 144 8.83 0.71 0.34 0.74 females 148 9.18 0.74 5years males 126 10.99 0.88 0.37 0.71 females 132 11.45 0.86 total males 270 9.84 0.56 0.51 0.61 females 280 10.25 0.57 table (3) shows caries-severity of deciduous teeth among the total sample. five years children were found to have higher dmfs mean value than four year old children, this difference was found to be statistically highly significant at p< 0.01. table (4) illustrates the dental caries among different levels of fathers and mothers education. the difference was found to be statistically not significant at p< 0.05 and mother education has great effect on caries prevalence which is gradually decrease when the level of the mother education increase, but this difference is statically not significant at p<0.05. table 3: dental caries severity (dmfs) by age age no. dmfs mean ± se student's t-test p 4 years 292 9.01 0.51 2.79** 0.005 5 years 258 11.23 0.61 total 550 10.05 0.40 **highly significant, df=548 table 4: dental caries in relation to parent education father mother edu. % dmfs mean ± se test % dmfs mean ± se test 1 5.1 9.71 1.72 f=1.14 p=0.33 df= 3 6.9 11.08 1.60 f=0.90 p=0.44 df= 3 2 24.0 10.68 0.81 29.1 10.33 0.70 3 41.3 10.51 0.65 43.6 10.27 0.63 4 29.6 8.95 0.69 20.4 8.81 0.85 j bagh college dentistry vol. 27(3), september 2015 dental caries pedodontics, orthodontics and preventive dentistry167 table (5) represents that the severity of dental caries is high with housekeeper compared to clerk women which is statistically not significant at p<0.05.table (6) showsthat although the difference was not significant at p<0.05 the severity of the dental caries increase when the age of the mother increase.table (7) representsthe effect of the presence of both parents will cause the severity of dental caries become less from the case when only the mother alive, but statistically not significant at p<0.05. table 5: dental caries in relation tomother's employment mother's employ % dmfs mean ± se student's t-test p housewife 81.1 10.36 0.45 1.61 0.11 clerk 18.9 8.72 0.84 table 6: dental caries in relation to mother age table 7: dental caries in relation to parent alive parent alive % dmfs mean±se student's t-test p both 98.5 10.02 0.40 0.56 0.58 father dead only 1.5 11.88 4.02 discussion the prevalence of dental caries was found to be (84.7%) for kindergarten children. this percentage was higher than that reported by many studies (9,10) while this percentage was lower than that reported by some studies (11,12) as well as the mean dmfs value was (10.05±0.40) which was higher than that recorded by some studies (13, 14), while was lower than that recorded by other studies (11, 12). the high caries prevalence recorded by this study may partly be attributed to lower fluoride level in drinking water in iraq that was ranging between 0.12-0.22 (15), and may also related to other factors related to the socioeconomic condition, living style of the families, dietary habits, oral hygiene measurements as well as dental health services. femaleshad higher cariesexperience (dmfs) than males with no significant difference present between them; this result is similar to that recorded by some studies (9,16). this finding may be attributed to the earlier eruption of deciduous teeth in females than males of the same age group, therefore, female's teeth will expose to environmental factors more than males, thus increasing risk for dental caries (17) while this finding disagreement with other studies (18,19). in this study, no significant differential caries among different levels of education this because the education concerns general knowledge not restricts only for oral health so the high educational level parents have less effect by oral disease. this result agrees with this study (20); and agrees with ojofeitimi et al study (21) who stated that caries in developed countries had become most prevalent in low socioeconomic groups while in developing countries it's started as a problem mainly in those high economic states. the mean dmfs of children of housekeeper mothers was higher than that among children of clerk mothers; this result which disagrees with alobaidi study (20) may be due to decrease knowledge and attitude especially for the housekeeper mothers in which there is strong positive correlation between the mother employment and education, and most of mothers in this study were housekeeper (81.1%), but it's not significant because the housekeeper mothers have enough time to take care of their children while the clerk mothers haven’t. moreover, children at this age group had not yet developed the knowledge and experience to choose food. knowledge, attitude and behavior about dental health were superficial and depend on their parent's especially the mother and the mother can prevent dental caries in children by providing a healthy diet, minimizing the consumption of sweets and getting early examination (22). mother's age % dmfs mean ± se test (16-25) 22.0 9.35 0.72 f= 0.84 p= 0.47 df= 3 (26-35) 51.5 9.86 0.56 (36-45) 23.8 11.12 0.90 (46-55) 2.7 9.76 2.21 j bagh college dentistry vol. 27(3), september 2015 dental caries pedodontics, orthodontics and preventive dentistry168 also the result showed that there was no significant difference in dental caries among different mother's age but because of illness and heavy problem of live, the children of older age mostly affected by oral disease and half of mothers were in median age (26-35) years. in this study, all the mothers were alive and the fathers dead in some cases about (1.5%), the differences was not significant with the dental caries in spite of this dental caries was higher in the children whom lost their father and only the mother alive, this may be due to the effect of the presence of the parent together to take care of their children better than the presence of the mother alone which is not enough. dental care professionals accept that efforts aimed at improving parental oral health behaviors could result in reductions in caries risk among their children (23). referances 1. marya. a textbook of public health dentistry.1st ed. new delhi: jaypee brothers; 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(ivsl). uday f.doc j bagh college dentistry vol. 25(4), december 2013 craniometric asymmetry oral diagnosis 60 craniometric asymmetry assessment in class i and class ii skeletal relationship patients using helical computed tomography sample aged between 18-35 years uday a. taha, b.d.s. (1) lamia h. al-nakib, b.d.s, m.sc. (2) abstract background: asymmetry assessment is an important component of orthodontic diagnosis and treatment planning. several studies attempted to find the relationship between craniometric asymmetry and skeletal jaws relationship and many authors found some extent of asymmetry in individuals with normal jaws relationship. the use of computed tomography (ct) allows for the assessment of asymmetry on a dimensionally accurate volumetric image, aim of the study is to determine if there are differences in craniometric asymmetry between patient with skeletal class i and patients with skeletal class ii relationship using helical ct scan. materials and methods: ninety individuals with clinically symmetrical faces were imaged with helical ct scan, and aging 18-35 years, divided into two groups, class ι group consisted of 31 individuals and class ιι group consisted of 59individuals. anatomical landmarks were defined and reference planes were established to determine the variance of the landmarks using a coordinate plane system. sagittal radiographs were used to determine the amount of the anb angle. asymmetry was analyzed by calculating the linear measurements and asymmetry indices of the anatomical landmarks by using coronal and axial radiographs in both classes. results: clinically symmetrical faces demonstrated a computed tomographic significant asymmetry with the vertical dimensions being significantly larger than the bilateral dimensions and the amount of asymmetry was more at the level of the mandible and less at the maxillary area. conclusions: the craniometric structures in terms of size and shape were larger in males than in females. the amount of asymmetry was independent on gender and skeletal jaws relationship and age. keywords: craniometric asymmetry, helical ct scan. (j bagh coll dentistry 2013; 25(4):60-65). introduction assessing symmetry is important in any esthetic evaluation of the craniofacial region. many experts consider symmetry to be of high importance in facial attractiveness (1-4). several studies have attempted to find a relationship between occlusion and craniofacial asymmetry, the severity of the craniofacial asymmetry was found to be independent of the severity of the malocclusion by (5,6). a potentially way to assess the importance of symmetry is by mirroring skeletal landmarks on both sides of the face and comparing this new face to the original. in these types of studies, the new symmetrical face is found to be more attractive than the original in studies of both male and female faces (2,7) the first ct scanner was invented in 1972 by godfrey hounsfield, since then these machines have gained greater sophistication and are being utilized in a wider array of clinical applications. in the modern medical ct, the x-ray source rotates within the gantry chamber that houses the x-ray tube and detector, while the patient is moved through the gantry on the bed. this method of ct scanning is known as helical ct and is the most widely used (8). (1) master student, department of oral diagnosis. college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. the aim of this study was to determine if there are differences in craniometric asymmetries between patients with a skeletal class ι anb angle compared to patients who have a skeletal class ιι using ct images. materials and methods the study was accomplished in the institute of x-ray in baghdad hospital. the study sample consisted of ninety patients attended the institute of x-ray for different diagnostic purposes. the patients were consecutively selected and fit inclusion criteria. mirroring technique was used to exclude patients with markedly asymmetric faces by comparing the right and left sides. the age ranged between 18-35 years. the subjects were divided into two groups according to the value of the anb angle. group 1 those with a class i skeletal relationship and clinically had normal, pleasant symmetrical faces, the value of anb angle 2-4º, it include 18 males and 13 females (9-11). group 2 those with a class ii skeletal relationship and clinically had normal, pleasant symmetrical faces, the value of anb angle 4º to 5º. it included 35 males and 24 females. each subject was extraorally examined by inspection to check for obvious facial asymmetry. mirroring technique was used to exclude patients with markedly j bagh college dentistry vol. 25(4), december 2013 craniometric asymmetry oral diagnosis 61 asymmetric faces by comparing the right and left sides. the landmarks sella , nasion and odontoid process of epistropheus ( dent ) were used to create the two reference planes that were used to measure linear distances from the landmarks (orbitale, condyle, and gonion) by calculating the distance of each of these landmarks from the reference planes in millimeters for the right and left sides of each patient. statistical analysis all the data of the sample were subjected to computerized statistical analysis using. computer program. the statistical analysis included: descriptive statistics: including means, standard deviation, statistical tables and figures, inferential statistics: independent samples t-test: for comparison between classes and genders, paired sample t-test: to assess the asymmetry of right and left measurements for both genders and both classes, cohen’s d: to estimate the sample size and as a measure of the effect size in which the values (0 to 0.3) represent a small effect size ,(0.3 to 0.6) represent a moderate effect size and the values larger than 0.6 represent a large effect size. results 1. craniometric linear measurements and indices for both classes results in table (1) reveal that in class ιι all linear measurements of the gonion and the condyle landmarks were larger than those in class ι with asymmetry indices more in class ιι than in class ι, while the linear measurements of the orbitale were larger in class ι than in class ιι with asymmetry index less in class ιι than in class ι. table 1: classes differences skeletal class class-i (n=31) class-ii (n=59) p (t-test) cohen’s d condyle-distance from transverse plane (mm)-mean rl 0.35[ns] 0.21 range (14.9 to 28.9) (11.3 to 37) mean 21.22 22.25 sd 4.18 5.25 se 0.75 0.68 gonion-distance from transverse plane (mm)-mean rl 0.43[ns] 0.18 range (66.8 to 105.5) (56.2 to 124.1) mean 89.06 90.98 sd 10.29 11.18 se 1.85 1.46 orbitale-percent lateral displacement 0.018 -0.54 range (0 to 42.4) (0 to 42.2) mean 14.95 10.42 sd 9.19 8.04 2. age differences in the craniometric linear measurements and indices for both classes the linear measurements of the anatomical landmarks for both age groups, showed a non significant differences between the two age groups, for class ι, and the same results were obtained for class ιι concerning the linear measurements of the anatomical landmarks for both age groups (table 2). 3. gender differences in the craniometric linear measurements and indices for both classes both class ι and class ιι the linear measurements of the anatomical landmarks showed non significant differences between males and females with craniometric linear measurements of the anatomical landmarks were mostly larger in males than in females (table 3). j bagh college dentistry vol. 25(4), december 2013 craniometric asymmetry oral diagnosis 62 table 2: age group differences age group (years) for skeletal class-i subjects <30 (n=16) 30-40 (n=15) p (t-test) cohen’s d condyle-vertical distance between right and left side 0.17[ns] -0.5 range (0.6 to 7.2) (0.4 to 5.5) mean 3.38 2.42 sd 2.24 1.48 gonion-distance from transverse plane (mm)-mean rl 0.11[ns] -0.59 range (77 to 105.5) (66.8 to 100.4) mean 91.93 85.99 sd 9.23 10.77 se 2.31 2.78 orbitale-vertical distance between right and left side 0.49[ns] -0.25 range (0 to 7.3) (0.4 to 4.3) mean 2.38 1.91 sd 2.29 1.29 se 0.57 0.33 age group (years) for skeletal class-ii subjects <30 (n=35) 30-40 (n=24) p (t-test) cohen’s d condyle-vertical distance between right and left side 0.43[ns] -0.21 range (0 to 8.6) (0.3 to 8.1) mean 3.64 3.14 sd 2.49 2.15 se 0.42 0.44 gonion-distance from transverse plane (mm)-mean rl 0.2[ns] 0.34 range (67.3 to 109) (56.2 to 124.1) mean 89.42 93.25 sd 9.52 13.12 se 1.61 2.68 orbitale-distance from transverse plane (mm)-mean rl 0.85[ns] 0.05 range (20 to 61) (22 to 52.8) mean 32.09 32.5 sd 8.52 7.86 se 1.44 1.6 discriminant analysis the mandibular-asymmetry index was ranked as the most important index among the other craniometric linear measurements and indices, while the gonia-distance from sagittal plane (mm)-left side was ranked the last one in this table which means that it has the least importance of effect between the two classes (table 4). j bagh college dentistry vol. 25(4), december 2013 craniometric asymmetry oral diagnosis 63 table 3: gender differences for skeletal class-i subjects female (n=13) male (n=18) p (t-test) cohen’s d condyle-distance from transverse plane (mm)-mean rl 0.21[ns] -0.47 range (16.1 to 28.9) (14.9 to 27.3) mean 22.35 20.41 sd 4.24 4.05 se 1.18 0.96 gonion-vertical distance between right and left side 0.41[ns] -0.3 range (0.1 to 9.4) (0 to 7.5) mean 3.98 3.1 sd 3.01 2.82 se 0.83 0.67 orbitale-vertical distance between right and left side 0.79[ns] 0.1 range (0 to 7.3) (0.4 to 5.6) mean 2.05 2.23 sd 2.03 1.78 se 0.56 0.42 for skeletal class-ii subjects female (n=13) male (n=18) p (t-test) cohen’s d condyle-distance from transverse plane (mm)-mean rl 0.72[ns] 0.09 range (11.8 to 32.6) (11.3 to 37) mean 21.97 22.46 sd 5.12 5.41 se 1 0.94 gonion-distance from transverse plane (mm)-mean rl 0.2[ns] 0.34 range (68.8 to 109.4) (56.2 to 124.1) mean 88.88 92.63 sd 10.32 11.7 se 2.02 2.04 orbitale-distance from transverse plane (mm)-mean rl 0.8[ns] 0.07 range (21.7 to 44.7) (20 to 61) mean 31.95 32.5 sd 5.73 9.78 se 1.12 1.7 table 4: discriminant analysis discriminant model for 29 selected measurements when used to discriminate between class-i and class-ii. rank according to importance (discriminating power) mandibular-asymmetry index 1 orbitale-lateral displacement (difference between right and left side horizontal distance from midline) 2 condyle-distance from transverse plane (mm)-left side 3 gonion-distance from sagital plane (mm)-left side 4 p (model) < 0.001 overall predictive accuracy = 73.3% wilks' lambda = 0.73 d = -0.123 + (0.107 x condyle-distance from transverse plane (mm)-left side) + (-0.081 x gonia-distance from sagital plane (mm)-left side) (-0.291 x orbitale-lateral displacement (difference between right and left side horizontal distance from midline)) + (0.481 x mandibular-asymmetry index) cut-off value = 0.197 class-ii ≥ cut-off value, class-i < cut-off value j bagh college dentistry vol. 25(4), december 2013 craniometric asymmetry oral diagnosis 64 discussion classes differences from the mentioned tables it was obvious that all the linear measurements and the asymmetry indices of the condyle and the gonion were larger in class ιι than in class ι, while for the orbitale all the linear measurements and the asymmetry indices were larger in class ι than in class ιι. these findings indicate that the linear measurements and the asymmetry indices were larger at the level of the mandibular area, this can be explained by knowing that head is a complex of different parts, each one of which serves different functions (12). growth of the mandible occurs essentially at the condyle, the growth at the condyle usually does not occur in the direction of ramus, but slightly forward. individual variation in the direction of growth at the condyles is large and, in the adolescent period, has been found to vary by almost 45 degrees. growth is not always linear in direction but usually curves slightly forward even backward (13, 14) described the mandibular growth pattern as racial in nature. enlow (15) has shown growth of the maxilla to be under the influence of the cranial base, which in turn is influenced by growth of the brain. the mandible, by virtue of its remoteness from the region, acts in a more independent way although its articulation at the glenoid fossa does provide potential for influence from the cranial base. age groups differences the results of this study showed a non significant difference between the two age groups for class ι for all landmarks, the same findings were in class ιι with some increase in the linear measurements of the condyle at the young age group, and an increase in the measurements of the goinion and orbitale at the older age group.this indicates that the amount of craniometric asymmetry in both classes was independent on the age; this is because the majority of the facial growth is usually completed by 16 -17 years of age (16). gender differences generally, most of the linear measurements and asymmetry indices values showed insignificant differences between males and females in both class ι and class ιι. this indicates that the degree of craniometric asymmetry was independent on gender in our study. this finding comes in agreement with (17-26). the results of this study also showed that some of the linear measurements values were larger in males than in females for both classes. these findings indicate that craniometric structures in terms of size and shape are larger in males than in females. references 1. moller ap, thornhill r. bilateral symmetry and sexual selection: a meta-analysis. am nat 1998; 151(2):174-92. 2. rhodes g. the evolutionary psychology of facial beauty. annu rev psychol 2006; 57:199-226. 3. hwang hs, hwang ch, lee kh, kang bc. maxillofacial 3-dimensional image analysis for the diagnosis of facial asymmetry. am j orthod dentofacial orthop 2006; 130(6):779-85. 4. hwang hs, youn is, lee kh, lim hj.classification of facial asymmetry by cluster analysis. am j orthod dentofacial orthop 2007; 132(3):279.e1-279.e6. 5. fischer b. asymmetries of dentofacial complex. angle ortho1954; 24(2): 179-92. (ivsl). 6. lundstrom a. some asymmetries of the dental arches, jaws and skull and their eitiological significance. am j orthod1961; 47(2): 81-106. 7. kowner r. facial asymmetry and attractiveness judgment in developmental perspective. j exp psychol hum percept perform1996; 22(3): 662-75. 8. hounsfield gn. computerized transverse axial scanning (tomography): part i. description of system. 1973. br j radiol1973; 68 (815): h166-72. 9. riedel ra. a cephalometric roentgenographic study of the relation of the maxilla and associated parts to the cranial base in normal and malocclusion of the teeth. thesis, northwestern university dental school 1948. 10. riedel ra. the relation of maxillary structures to cranium in malocclusion and in normal occlusion. angle orthod1952; 22(3):142-5. 11. steiner cc. cephalometrics for you and me.am j orthod 1953; 39(10):729-55. 12. brodie ag. late growth changes in the human face. angle orthod 1953; 23(3): 146-57. 13. bjork a. prediction of mandibular growth rotation. am j orthod1969; 55(6):585-99. 14. ricketts rm, bench rw, hilgers jj, schulhof r. an overview of computerized cephalometric. am j orthod 1972; 61(1): 1-28. 15. enlow dh. facial growth. 3rd ed. philadelphia: wb saunders; 1990. p.58-163. 16. jones ml, oliver rg. w & h orthodontics notes. 6th ed. oxford: wright; 2000. p.24, 28. 17. chebib fs, chamma am. indices of craniofacial asymmetry. angle orthod 1981; 51(3): 214-40. 18. habets ll, bezuur jn, naeiji m, hansson tl. the orthopantomograph, an aid in diagnosis of temporomandibular joint problems. ιι. the vertical symmetry. j oral rehabil 1988; 15(5):465-71. 19. al-mudhaffar nm. a radiographic study to analyze the craniofacial asymmetry of the normal iraqi dent j 1999; 24: 21-32. 20. yaseen ga. maxillomandibular asymmetry and facial dimensions in clinically symmetrical faces with class ι and class ιι subdivision 1 occlusions (an orthopantomographic study). a master thesis, department of pedodontics , othodontics and preventive dentistry, college of dentistry, university of baghdad, 1999. 21. saglam am. the condylar asymmetry measurements in different skeletal patterns. j oral rehabil 2003; j bagh college dentistry vol. 25(4), december 2013 craniometric asymmetry oral diagnosis 65 30(7):738-42. 22. kambylafkas p, kyrkanides s, tallents rh. mandibular asymmetry in adult patients with unilateral degenerative joint disease. angle orthod 2005; 75(3):305-10. 23. kiki a, kilic n, oktay h. condylar asymmetry in bilateral posterior crossbite patients. angle orthod 2007; 77(1):77-81. (ivsl). 24. sezgin os, celenk p, arici s. mandibular asymmetry in different occlusion patterns. angle orthod 2007; 77(5):804-7. 25. haraguchi s, iguchi y, takada k. asymmetry of the face in orthodontic patients. angle orthod 2008; 78(3): 421-6. 26. kurt g, uysal t, sisman y, ramoglu si. mandibular asymmetry in class ιι subdivision malocclusion. angle orthod 2008; 78(1):32-7. ali final.doc j bagh college dentistry vol. 26(2), june 2014 discoloration of orthodontics, pedodontics and preventive dentistry 125 discoloration of aesthetic bracket by mouth washes ali mohammed al-attar, b.d.s., m.sc. (1) abstract background: the present study aimed to determine the influence of the different types of mouth wash on discoloration of different orthodontic ceramic, sapphire brackets and adhesives. materials and methods: the sample composed of 120 ceramic brackets and 120 sapphire brackets, the brackets were divided according to bond material into three groups of 40 brackets include unbounded brackets, chemically cured (no-mix) bonded brackets and light cured bonded brackets all these groups were further subdivided according to mouth wash type into three groups with 10 brackets each which include; listerine, cetrimide, chlorhexidine 0.2%, and one control group which immersed in artificial saliva; then staining measurements were performed with uv-visible spectrophotometer . results and conclusions: all types of mouth wash cause staining, this effect was higher in ceramic than sapphire bracket and for no-mix than light cure bond bracket complex; the amount of staining low in listerine, intermediate in cetrimide, high in chlorhexidine for all bracket-bond complex. key words: discoloration, aesthetic bracket, mouth wash. (j bagh coll dentistry 2014; 26(2): 125-130). صةالخال 0غسول الفم على تلون الحاصرات التقومیة الخزفیة والیاقوتیة وكذللك اللواصقھدف ھذه الدراسة تحدید تأثیر انواع مختلفة من : الخلفیة ث مجموعات حاصرة تقومیة یاقوتیة، قسمت ھذه الحاصرات أعتمادا على نوع الالصق الى ثال 120حاصرة تقومیة خزفیة و 120تم أستخدام : المواد والطرق حاصرة تقومیة وھي مجموعة الحاصرات التقومیة غیر المرتبطة بالصق، مجموعة الحاصرات التقومیة المرتبطة بالالصق غیر المعتمد على 40تضم كل مجموعة ثالث مجامیع اعتمادا نوع غسول المزج ، مجموعة الحاصرات التقومیة المرتبطة بالالصق الضوئي التصلب،ثم قسمت كل مجوعة من ھذة المجامیع الثالثة الى .أستخدم جھاز المطیاف الضوئي لقیاس تلون الحاصرات التقومیة، ومجموعة رابعة حاكمة غمرت في اللعاب الصناعي) لسترین،سترماید،كلورھكسیدین(الفم اصرات التقومیة الخزفیة من الیاقوتیة وفي الالصق غیر جمیع انواع غسول الفم سبب تلون الحاصرات التقومیة،ھذا التأثیر اعلى في الح:النتائج واالستنتاجات .التلون كان قلیلال بسب غسول اللسترین متوسط في السترماید،عالیا في الكلورھكسیدین.المعتمد على المزج من الالصق الضوئي التصلب .التلون، الحاصرات التجملیة، غسول الفم :الكلمات المفتاحیة introduction as the numbers of adults seeking orthodontic treatment has increased, tooth-colored brackets were introduced to meet the demand for more esthetic appliances.(1) optical properties such as color stability of esthetic brackets has clinical implications for long-term color matching with the underlying teeth. the early plastic brackets were made of polycarbonate and plastic molding powder, which take up water and change color during service. therefore, these brackets did not last long because of discoloration, fragility, and breaking under stress. (2-5) advanced types of reinforced plastic brackets such as stainless steel slot inserts and composite resin brackets have been introduced since then.(6) brackets made of polycrystalline ceramic and monocrystalline sapphire became widely available in the mid 1980s.(7-9) ceramic brackets combined the esthetics of plastic brackets and the reliability of metal brackets. these brackets provide excellent color fidelity, and resist staining and discoloration.(10) there are internal and external causes for the discoloration of aesthetic brackets; external discoloration can be caused by food dyes and colored mouth rinses, material, e.g. the polymeric structure or filler content, and surface roughness play a decisive role in the extent of discoloration caused by diverse substances. (11) (1)lecturer. department of orthodontics. college of dentistry, university of baghdad. the amount of color change can be influenced by a number of factors including oral hygiene, water sorption, and incomplete polymerization. the reason for internal discoloration can be found in uv irradiation and thermal energy. uv light is able to induce physico-chemical reactions in the polymer, which cause irreversible color changes of the brackets. heat, acids, alkalis, oxygen, abrasion, enzymes, and radiation can all cause the chemical breakdown of esthetic brackets.(12) as to the color stability of ceramic brackets, it has been reported that monocrystalline and polycrystalline ceramic brackets resist staining or discoloration from any chemical substance likely to be encountered in the mouth; (10) however, ceramic brackets in the oral environment can be affected by color pigments in tea, coffee, and mouth wash.(13) one of the measures that help to ensure self maintenance of good oral hygiene is the use of mouthwashes. these mouthwashes may be fluoridated or non-fluoridated. the use of fluoridated mouth washes aims mainly to reduce the effects of enamel demineralization, while the other non fluoridated mouthwashes –the subject of this studyact in a major way as an anti-plaque agents (14,15). the aim of the present study was to determine the influence of the different types of mouth wash on discoloration of different orthodontic ceramic, sapphire brackets and adhesives. j bagh college dentistry vol. 26(2), june 2014 discoloration of orthodontics, pedodontics and preventive dentistry 126 materials and methods two types of orthodontic bracket were used; ceramic brackets (reflection©) and sapphire (pure©), also two types orthodontic bonding system were used chemically cure (no-mix) and light cure, all above materials supplied from ortho technology/usa. mouthwashes include listerine (pfizer, usa), cetrimide (pharcopharmaceuticals, egypt) and chlorhexidine 0.2%, (glaxosmithkline (gsk), uk). bonding procedure the sample composed of 120 ceramic brackets (reflection©) and 120 sapphire brackets (pure©), the brackets were divided according to bond material into three groups of 40 brackets: • unbounded brackets which were not bonded to any bond materials. • chemically cured (no-mix) bonded brackets in which the brackets were bonded using chemically cured adhesive resin (no-mix). • light cured bonded brackets in which the brackets were bonded using light cured adhesive resin. the ceramic and sapphire brackets were bonded with a chemically cured (no-mix), lightcured orthodontic adhesive as follow: • resilience primer® was applied by brush on each bracket base or resilience light cure primer® used with resilience® light-cure orthodontic adhesive. • a small amount of the adhesive paste was applied onto the bracket base, and then by using a clamping tweezers the bracket was placed lightly onto a horizontal flat plastic plate mounted on the table of surveyor (dent aurum, germany) covered by a celluloid strip to facilitate detachment of the bracket– adhesive complex with a recovery of the set material . • a constant load of two hundred grams was placed on the bracket to ensure a uniform thickness of the adhesive, the load fixed to the upper part of the vertical arm of the surveyor, a surveyor rod was fixed in the lower part of the vertical arm of the surveyor and put it in contact with the bonded bracket, excess adhesive was removed from around the bracket base with a sharp scalar. • the visible light-cured adhesive specimens were photopolymerized with a light-curing unit (woodpecker co., china); the light guide of curing light unit was directed toward the bracket, the light shined through the bracket for 20 second. the bonded brackets were allowed to bench set for 24 hr to ensure complete polymerization of adhesive material, then after setting; the celluloid strips were removed and the resultant bracketbonded adhesive were flat. immersion in mouth wash unbonded and bonded brackets were further subdivided according to mouth wash type into three groups with 10 brackets each which include listerine, cetrimide, chlorhexidine 0.2%, and one control group which immersed in artificial saliva fig. (1). the immersion procedure was done by positioned each bracket on a black rectangular cardboard (30×11×0.2 mm) with central window, the cardboards were numbered and using the number of the card as a reference ,the specimens then immersed in mouth wash contained in inert plastic containers for one hours at 37˚c in the incubator (16). figure 1: organization of sample j bagh college dentistry vol. 26(2), june 2014 discoloration of orthodontics, pedodontics and preventive dentistry 127 assessment of staining the samples were taken out of the immersion media; then staining measurements were performed over the 800 to 200 ŋm visible wavelength range with uv-visible spectrophotometer (t6uv, korea) fig. (2). the chamber of the spectrophotometer was opened, and then the black rectangular cardboard with bracket positioned in central window put inside cubit of the spectrophotometer fig. (3), then the chamber was closed and the machine was given the order to start scanning starting from 800ŋm wavelength in the infra-red zone to 200ŋm wavelength in the uv zone passing through the entire visible spectrum. the light passes through the sample; then the intensity of the remaining light was measured with a light sensor, the results appeared as a graph from which the amount of light absorption was plotted and the amount of absorbed light at a 345ŋm wavelength visible light was obtained and used in the later statistical analysis. statistical analysis 1. descriptive statistics: including mean, standard deviation, and standard error. 2. inferential statistics: including: one way analysis of variance (anova) to test any statistically significant difference among the light absorption of groups and least significant difference (lsd) to test any statistically significant differences between each two subgroups when anova showed a statistical significant difference within the same group. significance for all statistical tests was predetermined at p ≤ 0.05. results descriptive statistics show that light absorption increase when immersed bracket in mouth wash, light absorption was higher in ceramic than sapphire bracket and for no-mix than light cure bond bracket complex; the amount of light absorption low in listerine, intermediate in cetrimide, high in chlorhexidine for all bracketbond complex types (table 1) table 1: descriptive statistics of the amount of light absorption by different bracket groups in different mouth washes ceramic brackets there was significant difference among all group of ceramic brackets immersed in different types of mouth wash except unbounded control – listerine and listerinecetrimide groups show nonsignificant difference by lsd test (table 2). bracket control listerine cetrimide chlorhexidine mean sd mean sd mean sd mean sd ceramic unbounded 2.080 0.0043 2.088 0.0044 2.121 0.012 2.251 0.0461 +no-mix 2.143 0.0280 2.238 0.525 2.347 0.042 2.519 0.0463 +light cure 2.123 0.0127 2.199 0.049 2.328 0.069 2.449 0.0631 sapphire unbounded 2.073 0.0064 2.081 0.0077 2.119 0.0129 2.193 0.0300 +no-mix 2.1336 0.0279 2.211 0.494 2.300 0.0411 2.503 0.0486 +light cure 2.1134 0.1333 2.185 0.0487 2.292 0.0727 2.439 0.0599 figure 2: uv-visiblespectrophotometer (t6uv, korea). figure 3: black rectangular cardboard with bracket positioned in central window put inside cubit of the spectrophotometer. j bagh college dentistry vol. 26(2), june 2014 discoloration of orthodontics, pedodontics and preventive dentistry 128 table 2: difference in the amounts of light absorption of ceramic brackets immersed in different mouth washes brackets anova(df=39) lsd f-test p-value mouth wash mean difference p-value unbounded 108.72 0.000 * control listerine -0.0060 0.746 cetrimide -0.041 0.028* chlorhexidine -0.1702 0.000* listerine cetrimide -0.035 0.060 chlorhexidine -0.164 0.000* cetrimide chlorhexidine -0.129 0.000* ceramic +no-mix 138.04 0.000 * control listerine -0.046 0.000* cetrimide -0.203 0.000* chlorhexidine -0.375 0.000* listerine cetrimide -0.108 0.000* chlorhexidine -0.281 0.000* cetrimide chlorhexidine -0.172 0.000* ceramic +light cure 72.48 0.000 * control listerine -0.076 0.000* cetrimide -0.205 0.000* chlorhexidine -0.326 0.000* listerine cetrimide -0.128 0.000* chlorhexidine -0.249 0.000* cetrimide chlorhexidine -0.121 0.000* *significant sapphire brackets there was significant difference among all group of sapphire brackets immersed in different types of mouth wash except unbounded control – listerine group show nonsignificant difference by lsd test (table 3). table 3: difference in the amounts of light absorption of sapphire brackets immersed in different mouth washes brackets anova(df=39) lsd f-test p-value mouth wash mean difference p-value unbounded 101.37 0.000 * control listerine -0.0076 0.679 cetrimide -0.0459 0.014* chlorhexidine -0.1192 0.000* listerine cetrimide -0.0382 0.04* chlorhexidine -0.1115 0.000* cetrimide chlorhexidine -0.0733 0.000* sapphire +no-mix 139.50 0.000 * control listerine -0.0776 0.000* cetrimide -0.1669 0.000* chlorhexidine -0.3698 0.000* listerine cetrimide -0.0893 0.000* chlorhexidine -0.2922 0.000* cetrimide chlorhexidine -0.2029 0.000* sapphire +light cure 70.27 0.000 * control listerine -0.0722 0.000* cetrimide -0.179 0.000* chlorhexidine -0.326 0.000* listerine cetrimide -0.1068 0.000* chlorhexidine -0.2538 0.000* cetrimide chlorhexidine -0.147 0.000* effect of adhesive the amount of light absorption significant differ when compare unbounded bracket versus nomix and light cure bond bracket complex except sapphire brackets immersed in listerine there was nonsignificant difference between unbounded and light cure bond bracket. there was nonsignificant difference between no-mix and light cure bond bracket except for listerine and chlorhexidine there was significant difference (table 4). j bagh college dentistry vol. 26(2), june 2014 discoloration of orthodontics, pedodontics and preventive dentistry 129 table 4: difference between the different adhesives for light absorption after immersion in different mouth washes brackets anova df=29 lsd f-test p-value 1vs2 1vs3 2vs3 ceramic control 31.852 0.000* 0.001* 0.023* 0.272 listerine 41.415 0.000* 0.000* 0.000* 0.040* cetrimide 68.988 0.000* 0.000* 0.000* 0.316 chlorhexidine 70.013 0.000* 0.000* 0.000* 0.000* sapphire control 27.675 0.000* 0.001* 0.034* 0.277 listerine 28.985 0.000* 0.000* 0.087 0.000* cetrimide 43.629 0.000* 0.000* 0.000* 0.662 chlorhexidine 117.331 0.000* 0.000* 0.000* 0.001* (1 vs 2) unbonded bracket versus bracket bonded with no mix (1 vs 3) unbonded bracket versus bracket bonded with light cure (2 vs 3) bracket bonded with no mix versus bracket bonded with light cure discussion the test bracket in this study were ceramic and sapphire bracket because they are the most esthetic bracket now use. the use of listerine, cetrimide and chlorhexidine mouth washes because they widely use during orthodontic treatment as antiseptic agent ; but the side effects of reversible staining affect its wide spread; therefore study of this effect was done in this study. the immersion time intervals 60 minutes corresponded to an accumulative effect of daily use of the mouthwash for one month, considering that mouthwashes are usually used for one minute twice daily, the same time interval was used by other researchers (17,18) the increase stain of bracket when immerse in the mouth wash due to diffusion and adsorption of mouth wash molecule to the surface of bracket, sapphire bracket is more glazed surface and the bond between molecules are more stronger since its monocrystaline, so reduce overall surface roughness and adsorption of mouth wash on bracket surface than ceramic bracket. the stronger staining effect of chlorhexidine mouth wash due to probable electrostatic interaction between the positively charged (cationic) chlorhexidine molecules and the negatively charged ceramic surface, also chlorhexidine contain alcohol(15%) in its composition which increase surface degradation of bracket. the effect of cetrimide due to cationic nature of cetrimide and the negatively charged ceramic surface (electrostatic interaction), while listerine has slight acidic nature make effect less than other mouth wash (table 1). the lowest staining effect of listerine makes the difference between control-listerine group in both unbounded ceramic and sapphire brackets insignificant (table2 and 3). the significant difference between unbounded and bonded bracket (table 4) is due effect of adhesive, chemical cure resin(nomix)absorbed water molecules (physisorption), water is a softener of plastics and increases the deterioration of the resin matrix, which increase the monomer release from composite and increase the surface degradation of adhesive; produce rough surface which increase mouth wash deposition leading to increase stain(19), while the effect of light adhesive may be due to the ‘‘incomplete polymerization’’ phenomenon of light cure adhesive which occur due to number of factors that affect the depth of photo activated cures, including factors of illumination from the edges of bracket and critical total transmittance value of bracket in which duration and intensity of light exposure may be attenuated by the bracket structure, incomplete polymerization increase monomer leaching and cause alteration in light absorption values indicating a decreased color stability of light cure composite. since sapphire bracket more transparent than ceramic bracket so light transmission is more leading to more complete polymerization and since listerine less staining effect than other mouth wash making the difference between unbounded sapphire bracket and light cure bonded insignificant in listerine group (table 4). the significant difference in light absorption between no-mix and light cure in listerine and chlorhexidine mouth wash group may be due to acidic content of listerine and alcohol content of chlorhexidine which effect more in no-mix than light cure this agree with sargison et al (20) and sanders et al (21) references 1. birnie d. orthodontic materials update. ceramic brackets. br j orthod 1990; 17:71-5. j bagh college dentistry vol. 26(2), june 2014 discoloration of orthodontics, pedodontics and preventive dentistry 130 2. miura f, nakagawa k, masuhara e. new direct bonding system for plastic brackets. am j orthod 1971; 59: 350-61. 3. reynolds ir. a review of direct orthodontic bonding. br j orthod 1975; 2:171-5. 4. de pulido lg, powers jm. bond strength of orthodontic direct bonding cement-plastic bracket systems in vitro. am j orthod 1983; 83: 124-30. 5. newman gv. first direct bonding in orthodontia. am j orthod dentofacial orthop 2007; 132(3):190-1. (ivsl). 6. sinha pk, nanda rs. esthetic orthodontic appliances and bonding concerns for adults. dent clin north am 1997; 41: 89-109. 7. winchester l. bond strengths of five different ceramic brackets: an in vitro study. eur j orthod 1991; 13: 293-305. 8. harris a, joseph v, rossouw p. shear peel bond strengths of esthetic orthodontic brackets. am j orthod dentofacial orthop 20011; 102: 215-9. (ivsl). 9. liu jk, chung ch, chang cy, shieh db. bond strength and debonding characteristics of a new ceramic bracket. am j orthod dentofacial orthop 20012; 142: 761-5. (ivsl). 10. swartz ml. ceramic brackets. j clin orthod 2008; 22: 82-9. 11. khokhar za, razzog me, yaman p. color stability of restorative resins. quintessence international 2001; 22: 733-7. 12. kusy rp, whitley jq. degradation of plastic polyoxymethylene brackets and the subsequent release of toxic formaldehyde. am j orthod dentofacial orthop 2005; 127: 420-7. 13. bishara se, fehr de. ceramic brackets: something old, something new—a review. semin orthod 2013; 33: 178-88. 14. eriksen hm, nordbo h, kantanin h. chemical plaque control and extrinsic tooth discoloration, a review of possible mechanisms. j clin periodontol 1985; 12; 245-50. 15. eley bm. antibacterial agents in the control of supragingival plaque br dent j 2012; 196; 286-96. 16. stober t, gilde h, lenz p. color stability of highly filled composite resin materials for facings. dental materials 2001; 17: 87-94 17. hassu jeh. the influence of saliva and/or tea on the staining ability of chlorhexidine to hot cures acrylic resin as a mouth wash and its staining effect as a disinfectant. master thesis, college of dentistry, university of baghdad, 1998. 18. kadhum as. the effects of three mouth washes on the load-deflection and surface characteristics of nickel titanium arch wires, a master thesis, orthodontic department, college of dentistry, university of baghdad, 2007. 19. sonis al. comparison of a light-cured adhesive with an autopolymerization bonding system. j clin orthod 1988; 22(11): 730-2. 20. sargison ae, mccabe jf, gordon ph. an ex vivo study of self, light and dual cured composites for orthodontic bonding. br j orthod 1995; 22(4): 319-23. 21. sanders bj, gregory rl, moore k, avery dr. antibacterial and physical properties of resin modified glass-ionomer cements combined with chlorhexidine. j oral rehabil 2002; 29: 553-8. warkaa f.doc j bagh college dentistry vol. 25(2), june 2013 the role of low oral diagnosis 108 the role of low level laser therapy on the expression of il_1 beta in wound healing warkaa m. al-wattar, b.d.s, m.sc. (1) bashar h. abdulluh, b.d.s, m.sc., ph.d. (2) ali s. mahmmod, m.b.ch.b., f.i.c.m.s. (3) absract background: low-level laser therapy (lllt) has been extensively applied to improve wound healing due to some biostimulatory properties presented by laser arrays apparently able to accelerate the repair of soft tissue injuries. however, the role of proinflammatory interlukines not been studied yet. il_1 β represent one of the most important poroinflammatory interlukines that involved in wound healing. the goal of this study was to investigate the effect of 790-805nm diode laser on the expression of il_1 β during wound healing in mice. materials and methods: standard-sized wounds (1.5cm) were carried out in the face of 96 white albino mice. half of them underwent lllt treatment (360 j/cm 2) at 790-805 nm delivered immediately after wound procedure. the repairing area was removed and stained with immunohistochemistry technique to detect the expression of il_1 β. results it had been found that lllt was able to increase the expression of the il_1 β in early phases of healing as well as to enhance epithelization remodeling process at both 7 th and 14 th days of wound healing. conclusions : the lllt protocol tested in this study resulted in increased the expression of il_1 β in the lased group significantly at day 7 of healing period which affect wound healing. keywords: low level laser therapy (lllt), photobiomodulation, il_1β. (j bagh coll dentistry 2013; 25(2):108-113). introduction lllt or "cold" lasers use radiation intensities so low that it is thought that any biological effects that occur are due to the direct effects of radiation rather than the result of heating. lllt devices have been advocated for relief of pain, healing of soft tissue disorders, and treatment of peripheral neuropathies and primarily include the galliumaluminum (gaal), gallium-arsenide (gaas), gallium-aluminum-arsenide (gaala) and heliumneon (he-ne) laser. the he-ne laser was the first laser available and is reported to have beneficial effects in both wound healing and dentistry. the gaas and gaalas laser have been most commonly used for the treatment of pain and inflammation and in lower doses for wound healing as they have deeper tissue penetration than the he-ne laser (1-4). tissue healing (or tissue repair) refers to the body's replacement of destroyed tissue by living tissue and comprises two essential components regeneration and repair. the differentiation between the two is based on the resultant tissue. in regeneration, specialized tissues are replaced by the proliferation of surrounding undamaged specialized cells. in repair, lost tissue is replaced by granulation tissue which matures to form scar tissue. (1)ph.d. student. department of oral diagnosis. college of dentistry. university of baghdad. (2)assistant professor. department of oral diagnosis. college of dentistry. university of baghdad. (3)assistant professor. laser institute of postgraduated study. university of baghdad. there are several different ways to‘divide up’ the healing process, but the allocation of 4 phases is common and will be adopted here – these being bleeding, inflammation, proliferation and remodeling (5). different substances absorb light of different wavelengths for example; the cells of injured skin are more sensitive than those of intact tissue. once the target cells have absorbed the photons a cascade of biochemical events occur with the ultimate result of accelerated wound healing. laser therapy is thought to work through a variety of mechanisms: • growth factor response within cells and tissue as a result of increased atp and protein synthesis, improved cell proliferation and change in cell membrane permeability to calcium up-take. • a cascade of metabolic effects results in various physiological changes which results in improved tissue repair, faster resolution of the inflammatory response, and a reduction in pain (6). the most effective growth factors and cytokines in cutaneous wound healing are platelet derived growth factor, vascular endothelial growth factor, transforming growth factor, fibroblast growth factor, epidermal growth factor insulin-like growth factor and interlukines (7). interleukin -1 beta (il-β) a member of interlukin 1 cytokine family. this cytokine is produced by activated macrophages as a proprotein which is proteolytically processed to its active form by caspase -1.this cytokine is an important mediator of the inflammatory response and is involved in a variety of cellular activities ;including cell proliferation, differention, and j bagh college dentistry vol. 25(2), june 2013 the role of low oral diagnosis 109 apoptosis.. the function of il-1 β could be summarized as follow: 1. upregulate inflammatory response. 2. recruit and activate neutrophils monocytes. 3. cause upregulation of endothelial adhesion molecules. 4. promote lymphocyte endothelial transmigration (8). the goal of this study was to investigate the effect of 780-805nm diode laser on the expression of il-1 β in incisional wound healing in mice. materials and methods: ninety –six white albino mice weighting 150200gm; 3-6 months old were used in this study. the animals were divided into 2 groups, control group which includes 48 animals and lased group includes 48 animals. laser system: laser system which is used in this study is an infrared (ga al as) diode laser, class iv laser (k-laser, italy), its wavelength is 790-805 nm, mode of operation is modulated cw, maximum cw power is 4 w. animal irradiation: the surgical field was done on the check side. an incision was done with 1.5cm length. the animals of lased group had been irradiated by an infrared diode laser while the wound of the control group did'nt irradiated. the animals were divided into 4 groups related to healing period intervals:the specimens were taken from both groups in 1st, 3rd, 7th and 14th days and prepared for histological examination. animals of laser experimental groups were treated with argaal laser arrays of 790-805-nm wavelength obtained from a laser apparatus(klaser-italy). the treatment applied immediately following surgical procedure consisted of 780-905 nm for 90 s, 4w (output power), and an energy density of 360 j/cm 2. focal spot was 8mm. laser array was positioned directly over the animal at a vertical distance of 0.5 cm from the edge of the wound and irradiation was performed at one spot to cover the wound area. after the sacrifice of the animals, the wound area was surgically removed, fixed in buffered 10% formalin, and paraffin embedded. subsequently, serial 4-µm sections were obtained and prepared to be stained immunohistochemistry with lsab type. the immunostaining kit and the interlukine 1 beta was obtained from santa cruz company,usa (table 1). table1: data information of santa cruze il-1beta growth factor chromosomal location source product il-1.ß il-1bhuman mapping to 2q14’il-1b mouse mappingto2 f rabbit polyclonal antibody raised against amino acids 117-269 of il-1b of human origin. vial contains 200μg in 0.1ml of pbs with<0.1 % sodium azide and 0.1 %gelatin. immunohistochemistry staining procedure: the procedure of immunostaining includes several steps which were: deparaffinizion the tissue sections, rehydration ,perxidase block ,protein block,primary antibodies,biotinylated link(secondary antibody), streptavidinhrpreagent,dab.counter stain, dehydration, mounting. immunohistochemical staining analysis: il1ß: the localization of the stain will be extracellular, as pleiotrophic expression. it will release from neutrophils and macrophages and is in the epithelial cells of epidermis and stromal component (inflammatory cells, blood vessels fibrous connective tissue) as brown stain. the scoring system was used according to (9).tow-four fields from each section were used and expressed as counts per mm2 area for each animal. scoring of expression was 0(no stain), 1(<10), 2(10-25%), 3(25-50%), 4(50%<). statistical analysis: results are expressed as mean ±standard deviation (sd). statistical difference was assessed by analysis of variance (anova) followed by t test .a p value<0.05 was considered to be significant; while 0.001 was highly significant. results control group: 1. epidermal expression: the ihc positive stain for il-b expressed in day 1, then increased in day 3 to return decreased 7, and increased again in day 14 on keratinocytes. 2. stromal expression: the positive stain expressed in day 1 then increased in day 3 to be decreased in day7 and increased again in 14. (fig.1, 3, 5 and 7). laser group: 1. epidermal expression: expressed in day 1 and decreased in day 3, 7, and day 14. 2. stromal expression: expressed in day 1 and increased in day 3, 7 , and 14. (fig.2,4,6,and 8). j bagh college dentistry vol. 25(2), june 2013 the role of low oral diagnosis 110 statistical analysis of il-1β: a-comparison between the control and laser groups: according to (table 2), there was significant difference between the control and laser groups at day 7 healing period for stromal expression (p≤ 0.05). b-comparison between epidermal and stromal expression of il-1β: the result of the test (table-3) showed that there was no significant difference between epidermal and stromal expression of il-1β in control group except in day 1 of healing period (p≤ 0.05); while for laser group there was significant difference (p≤ 0.05) between epidermal and stromal expression of il-1β in day 1and 3 of healing and significance in day 14 for (p≤ 0.05). day 7 showed highly significant difference 1(p≤ 0.001). discussion the healing process is initiated immediately after injury by the release of various growth factors, cytokines and low-molecular weight compounds from the injured blood vessels and from the degranulating platelets (10). the inflammatory cells start infiltrating the wound tissue within hours after the injury and represent a major source of growth factors like pdgf,vegf,tgf, and cytokines likeil-1,il2,il-3,il-4,il-6 andil-8 ;which initiate the proliferative phase of wound repair which starts with the migration and proliferation of keratinocytes at the wound edge which is followed by proliferation of dermal fibroblasts in neighborhood of the wound to form a framework of fibrous connective tissue connecting wound edges together to closed the wound gap and allow completion of healing(7).low level laser therapy affect different types of cells and tissue as a result of increased atp production and protein synthesis within the cells which affect cells proliferation and change in cell membrane permeability to increase calcium up-take. these factors are produced by immune cells infiltrated to the wound area like (neutrophils, monocytes, macrophages and lymphocyte, in addition to peripheral nerve endings, fibroblasts, endothelial cells and other non-immune cells (10). il-1β represents a proliferation cytokines that regulates many aspects of the immune and inflammatory responses. there are 2 types of il-1ligands with agonist activity; like il-1α and il-β which are produced by various kinds of cells such as neutrophils, monocytes, macrophages, fibroblasts and keratinocytes. both il-1α and il-β bind to same receptors and have similar ; if not identical ,biological properties which their expression more strongly enhanced during wound healing (11) .it’s the first important cytokines that released after injury and it’s responsible for initiation of inflammation, cell recruitment to wound bed, debris removal and promotion of proliferative phase of healing (10) .in this study; the epidermal expression of il-1ß in the control group was seen in the day 3 higher than day 1 .this result could be explained from point of view that the lymphocytes infiltrate the epidermis at wound site and adhere to keratinocytes which lead to activation of both cell types to generate proinflammatory cytokines including il-1ß and when the acute inflammation subsided in day 7 the expression of epidermal il-1β inclined in its lowest level may be due to reduction of proinflammatory effect need (12) .the elevation of epidermal expression of il-1ß in day 14 again may be related to their apoptotic effect of this cytokine (13,14).the stromal expression of il-1ß in the control group was also seen in higher level in the day 1 then decline in day 3 and 7. this may be due to the pro-inflammatory effect of il-1ß and its relation with neutrophils count which are represented one of the major producers of this cytokine (11) .the elevation of both epidermal and stromal expression of il-1ß in the control group in day 14 may be not related to its proinflammatory effect but due to its apoptosis effect on keratinocytes to affect apoptosis of these cells during remodeling phase of wound healing and the cell responsible for this is macrophage (13,14) . this result was confirmed by comparison of the il-1ß expression between epidermis and stroma in day 1 which was significant may be due to the neutrophils' count in acute inflammatory phase of wound healing (11) . the epidermal expression of il-1ß in the laser group was seen in day 1 and decreased gradually in day 3,7 and 14. this may be due to the role of lllt on the surface epithelium cells (keratinocytes) to produce the por-inflammatory cytokines including il-1ß which is needed in the acute inflammation during wound healing (11) , but this effect reduced later on may be due to lllt anti-inflammatory effects are directly related to reduction of pro-inflammatory cytokines, as well as the amount of chemical mediators. the results of indicate that lllt induces an inflammatory reaction that may modulate transcription factors linked to mrna expression proinflammatory cytokines. these data are corroborated by previous studies which suggested that laser therapy can reduce the production of inflammatory mediators and events that contribute to the inhibition of il-1β.the stromal expression of il-1ß in the laser group was seen in day 1 and decrease in day 3.this early j bagh college dentistry vol. 25(2), june 2013 the role of low oral diagnosis 111 elevation in the expression may be due to the effect of lllt on neutrophils and lymphocytes to produce pro-inflammatory cytokines including il1ß in acute inflammation phase of wound healing which subside in day 3 of healing period (7) while the elevation in the stromal expression in day 7and 14 may be due to that lllt stimulated keratinocytes production of il-1ß and which could be affect wound healing by promotion of proliferative phase of healing (15,11) .the comparison showed that the significant difference between the control and laser group only seen in stromal expression at day 7 of healing period. this may be due to the activated macrophages and fibroblasts production of il-1ß that play a role in cell proliferation and collagen matrix deposition , pro-matrix metalloproteinase during wound healing (16-19) . this agreed with (20) who found that il-1 concentration in burn tissue wound would reach its peak at day 6 then declined gradually which indicate correlation with earlier phases of healing, but disagreed with (21) who found that gene expression of il-1beta and ifngamma was significantly and suggested that lllt decreases the amount of inflammation and accelerates the wound healing process, altering the expression of genes responsible for the production of inflammatory cytokines.as a general observation; 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6:705–714 20. jurjs a, atiyeh bs, abudallah im, jurjus ra, hayek sw, jaounde m, gerges a, tohm ra. pharmacological modulation of wound healing in experimental. burns doi 2007; 10:1016. 21. safavi sm, kazemi b, esmaeili m, fallah a, modarresi a, mir m.effect of low level he-ne laser on gen expression of il-1β,tgf-β,inf-γ,tgf-α.bfgf and pdgf, in rat gingival. lasers in medical science 2007; 23(3): 331-5. j bagh college dentistry vol. 25(2), june 2013 the role of low oral diagnosis 112 table 2: independent t-test for il-1b expression for the significant mean difference between control and laser groups day control laser p-value t-test sig. m sd m sd 1-epidermal .666 0.01 .833 .38 .377 -.919 ns 1-stromal 1 .426 1.33 .65 .153 -1.83 ns 3-epidermal .75 .45 .58 .514 .418 .842 ns 3-stromal .91 .666 .58 .79 .589 .842 ns 7-epidermal .25 .45 .58 .51 .120 -1.684 ns 7-stromal .33 .65 1.08 .666 .017 -2.783 s 14-epidermal .666 .49 .58 .51 .693 .405 ns 14-stromal .75 .62 1 .73 .389 -.897 ns table 3: paired t-test for epidermal and stromal expression of il-1β in control and laser group at different healing period period mean difference se t-test p-value sig. day-1/control -.33 .142 2.345 .038 s day-1/laser -.42 .183 2.159 .053 s day-3/control -.17 .167 1 .338 ns day-3/laser -.5 .23 2.171 .52 s day-7/control -.08 .083 1 .338 ns day-7/laser -.5 .151 3.317 .007 hs day-14/control -.08 -.083 1 .338 ns day-14/laser -.42 .149 2.803 .0172 s fig 1: day 1 control group showing stromal expression of il-1β fig 2: day 1 laser group showing stromal expression of il-1β j bagh college dentistry vol. 25(2), june 2013 the role of low oral diagnosis 113 fig 5: day 7 control group showing stromal expression of il-1β fig 6: day 7 lased group showing stromal expression of il-1β fig 8: day 14 lased group showing stromal expression of il-1β fig 7: day 14 control group showing stromal expression of il-1β fig 4: day 3 lased group showing stromal expression of il-1β fig 3: day 3 control group showing stromal expression of il-1β essra'a.doc j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry167 the relation among ramal width and length with some cervical and cranio-facial measurements in different skeletal classes esraa s. jassim, b.d.s., m.sc. (1) abstract background: the purpose of this study was to assess the relation among the ramal length and width with various cervical and cranio-facial measurements for a sample of iraqi adults with different skeletal classes. materials and method: the sample composed of 71 iraqi adults (36 females and 35 males) with an age ranged between 17-30 years and had different skeletal mal-relations using sna, snb and anb to differentiate between them and assorting them into cl.i, cl.ii and cl.iii mal-relation. each individual was subjected to clinical examination and digital true lateral cephalometric radiograph that had been analyzed using autocad 2007 software computer program to determine sixteen linear and ten angular measurements. descriptive statistics were obtained and independent samples t-test was performed to evaluate the gender differences in different classes. anova test as used to compare the measurements among the skeletal classes in each gender, while pearson’s correlation coefficient test was used to determine the relations among ramal length and width with other measurements in all classes. results and conclusions: all of the linear measurements were significantly higher in males than females. on the other hand, the angular measurements showed non-significant gender difference except for sn-pp angle in class ii group. anova test showed statistically significant difference in upper gonial angle, y-axis angle and the mandibular length. ramal length and width correlated significantly with pfh, sn-mp angle and co-gn. key words: ramal height, ramal width, first cervical vertebral morphology, mandibular morphology. (j bagh coll dentistry 2014; 26(4):167-174). introduction almost 50 years later, orthopedic modification of facial growth is still a topic of great interest to practicing orthodontists. a review of the literature revealed a general consensus that, while clinicians can use orthopedic appliances such as headgear to modify maxillary growth, the effects of mandibular orthopedic appliances, such as bionators, on mandibular growth are more controversial. one reason for the unpredictable response of the mandible to orthopedic treatment may be related to the complex morphology of the bone. the mandible can be divided into four functional components: the condyle, the ramus, the corpus, and the alveolus (1). björk stated that different individuals exhibit different patterns of mandibular growth and the other authors have proposed that the mandible does not follow one characteristic pattern throughout life; it is likely that the map of mandibular growth varies with the age of the individual (2). a significant point to mention is that, the rami are important compensatory structures involved in mandibular adaptations during growth, because if the mandibular ramus is just three or four millimeters too wide or too narrow, a corresponding retrusive or protrusive malocclusion can exist and if the ramus is vertically a few millimeters too short or too long, there is a basis for a vertical malocclusion (3) but what about the different skeletal classes? for that (1)lecturer. department of orthodontics, college of dentistry, university of baghdad reason, a trial to study the relation among the ramus width and length with different cervical and cranio-facial parameters in different skeletal classes was established. the aim of this study was to find the relation between the ramus height {measured from condylion to gonion (4)} and ramus width {measured the length of the line drawn from midplaned deepest points on posterior and anterior borders of ramus (5)} with some cervical and cranio-facial measurements in a sample of iraqi adults with different skeletal classes. material and methods sample the sample comprised of 71 subjects including dental students and some patients attending the orthodontic department at the college of dentistry, university of baghdad. all individuals were iraqi adults (36 females and 35 males) with an age ranged between 17-30 years. all the subjects had complete permanent dentition regardless the third molars. they were clinically healthy with no syndromes or evidence of craniofacial anomalies such as cleft lip and/or palate. none had a history facial trauma or previous orthodontic, orthopedic or surgical treatment (6). the samples were classified according to anb angle (7) into: 1. skeletal cl i: anb 2°4°. 2. skeletal cl ii: anb > 4°. 3. skeletal cl iii: anb < 2°. j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry168 methods a digital true lateral cephalometric radiograph was taken for each individual using planmeca promax radiograph unit after clinical examination for him/her. the individual was positioned within the cephalostat with the sagittal plane of the head vertical, the frankfort plane horizontal and the teeth were in centric occlusion. every radiograph was analyzed by autocad 2007 software computer program to calculate the angular and linear measurements after correcting the magnification. cephalometric landmarks, planes and measurements (figure 1) -cephalometric landmarks: 1. point n (nasion): the most anterior point on the naso-frontal suture in the median plane (9). 2. point s (sella): the midpoint of the hypophysial fossa (8). 3. point ar (articulare): the point of intersection of the external dorsal contour of the mandibular condyle and the temporal bone (11). 4. point go (gonion): a point on the curvature of the angle of the mandible located by bisecting the angle formed by the lines tangent to the posterior ramus and inferior border of the mandible (7). 5. point gn (gnation): a point located between the most anterior and the most inferior point of the chin (8). 6. point me (menton): the lowest point on the symphyseal shadow of the mandible seen on a lateral cephalogram (7). 7. point a (subspinale): the deepest midline point on the premaxilla between the anterior nasal spine and prosthion (9). 8. point b (supramentale): the deepest midline point on the mandible between infradentale and pogonion (9). 9. point ans (anterior nasal spine): it is the tip of the bony anterior nasal spine in the median plane (8). 10. point pns (posterior nasal spine): this is a constructed radiological point, the intersection of a continuation of the anterior wall of the pterygopalatine fossa and the floor of the nose. it marks the dorsal limit of the maxilla (8). -cephalometric planes: 1. n-a line: formed by a line joining nasion and point a (8,9,12). 2. n-b line: formed by a line joining nasion and point b (8,9,12). 3. s-n plane: formed by a line joining sella turcica and nasion. it represents the length of anterior cranial base (8). 4. s-ar plane: formed by a line joining sella turcica and articulare. it represents the lateral extent of the cranial base (8). 5. ar-go plane: formed by a line joining articulare and gonion (8). 6. go-gn line: formed by a line joining gonion and gnation and represent the external body length of mandible (5). 7. co-gn line (maximum mandibular length): formed by a line joining condylion and gnathion (5,21). 8. palatal plane (pp): formed by a line joining anterior and posterior nasal spines (8). 9. mandibular plane (go-me): formed by a line joining gonion and menton (8). 10. anterior facial height (n-me): the distance between nasion and menton (8). 11. posterior facial height (s-go): the distance between sella turcica and gonion (8). 12. ramus height (co-go): it is measured from condylion to gonion (4). 13. ramus width: it is measured the length of the line drawn from mid-planed deepest points on posterior and anterior borders of ramus (5). 14. a-p line: it is the maximum antero-posterior extent of atlas vertebra (8,15). 15. atlas venter: it is the maximum vertical extent of the atlas ventral arch perpendicular to the length of the atlas a-p (8,15). 16. atlas dors: it is the maximum vertical extent of the atlas dorsal arch perpendicular to the length of the atlas a-p (8,15). -cephalometric angles: 1. anb angle: the angle between lines n-a and n-b. it represents the difference between sna and snb angles or it may be measured directly as the angle anb. it is the most commonly used measurement for appraising anteroposterior disharmony of the jaws (10). 2. sn-mp angle: the angle between the s-n plane and the mandibular plane (8). 3. sn-pp angle: the angle between the s-n plane and the palatal plane (13). 4. pp-mp: the angle between palatal plane and mandibular plane (8). 5. n-s-ar: saddle angle, between the anterior and the posterior cranial base. this angle formed at the point of intersection of the s-n plane and the s-ar plane (12). 6. s-ar-go: articular angle, formed at the point of intersection of the s-ar plane and the argo plane (12). 7. ar-go-me: gonial angle, formed at the point of intersection of ar-go plane and the mandibular plane (go-me) (12). j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry169 8. go1 angle: formed by the ascending ramus and the line joining nasion and gonion and it indicate anterior direction of growth (8). 9. go2 angle: formed by the line joining nasion and gonion with mandibular plane (8). 10. y-axis angle (n-s-gn): is formed at the point of intersection of s-n plane and s-gn plane (8). statistical analyses all the data of the sample were subjected to computerized statistical analysis using spss version 15 (2006) computer program. the statistical analyses included: • descriptive statistics; include means, standard deviations (s.d.) and statistical tables. • inferential statistics; include ÿ independent-samples t-test: for the comparison of the measurements between genders in each class. ÿ anova test: for the comparison of the measurements among the classes in each gender. ÿ lsd test: used to test the significant between every two groups if anova gives significant results. ÿ pearson correlation coefficient test (r): it is used to find the relationship between the measured variables. in the statistical evaluation, the following levels of significance were used: non-significant ns p>0.05 significant * 0.05≥p>0.01 highly significant ** p≤0.01 results table 1 showed the descriptive statistics of the linear measurements for both males and females in different skeletal classes. generally, all of the mandibular measurements were higher significantly in males than females in all classes except. the ventricle and dorsal lengths of atlas showed non-significant genders difference in all classes and the anteroposterior extent of atlas in class i only. figure 1: cephalometric landmarks and measurements: n: nasion. s: sella turcica. ar: articulare. go: gonion. me: menton. gn: gnation. a: subspinale. b: supramentale. ans: anterior nasal spine. pns: posterior nasal spine. co: condylion 1: s-n. 2: n-a. 3: n-b. 4: n-me (afh). 5: sgo (pfh). 6: s-ar. 7: ar-go. 8: co-go (ramus height). 9: go-gn (external body length of mandible). 10: co-gn (maximum mandibular length). 11: go-me (mandibular plane). 12: ramus width. 13: n-go. 14: s-me. 15: a-p line. 16: atlas dors. 17: atlas venter. 18: ans-pns (pp line). 19: sna. 20: snb. 21: anb. 22: n-s-me (y-axis). 23: n-sa-r (saddle angle). 24: s-ar-go (articular angle). 25: ar-go-me (gonial angle). 26: go 1. 27: go 2. 28: sn-pp. 29: pp-mp. 20: sn-mp. j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry170 anova test show significant difference in the co-go and go-gn in males and in co-gn in females. table 2 demonstrated the descriptive statistics of the angular measurements used in this study for both genders. in all of the measured variables, there was no significant gender difference except for sn-pp angle where there was highly significant difference. classes' difference showed significant difference in upper gonial angle and yaxis angle only. table 3 showed the relation between the ramal width and height with the other variables. the mandibular length and posterior facial height were the most variables that showed significant relation. discussion this study aimed to found if there is any relation among ramal width and length with some cervical and cranio-facial parameters in different skeletal classes. all of the linear measurements were significantly higher in males than females in all classes as shown in table 1; this comes in agreement with the previous study (16-20). this may be due to the fact that the maturation period is attained earlier in females than males and that gives chance for more growth period in males. other explanation may be attributed to the differences in muscular mass and force which are greater in males than females (14). the highly significant difference in all skeletal classes for sn is due to the positive relation between the growth of anterior cranial base and the growth of mandible as explained by knott (22) and since that the direction of mandibular growth affect on skeletal classes so the sn will differ in different skeletal classes (6,23,24), the same thing for pfh, mandibular length (go-gn) and maximum mandibular length (co-gn) where there is abundance of literatures explained this relation. when the mandible rotates during growth, it affect the vertical relationships of the face, that mean the over development of anterior facial height result in backward rotation of mandible and vice versa; for that reason the afh show highly significant difference in cl.ii because it's greatly affected by the direction of mandibular rotation (6, 26). the results of anova test in this study show significant difference in go.1 angle and co-gn in female which is most commonly seen between cl.i-ii and cl.i-iii as resulted in lsd test, and that is because the go angle give an expression for the form of the mandible, with reference to the relation between body and ramus (8). the go angle also plays a role in growth prognosis, if the upper gonial angle is increased; the direction of mandibular growth may be expected to be sagittal. while, if the lower angle is small; the direction of growth is likely to be caudal. such a changes can be found in both cl.ii and c.iii, for that reason a significant differences can be found in go angle and also maximum length of mandible (8,25,26). since the growth at the head of the condyle occurs in an upward and backward direction, the mandibular growth is expressed as a downward and forward displacement, the growth at the condyles compensates for the vertical displacement of the mandible and accommodates for the eruption of the teeth vertically. on the other hand, bone resorption at the anterior border and deposition at the posterior border of the two rami account for the anteroposterior growth of the mandibular rami and body. these changes increase the posterior length of the body of the mandible to accommodate for the erupting permanent molars (27). mclaughlin et al. (28) and proffit et al. (29) mentioned that adolescent patients can tolerate molar extrusion, because any extrusion is compensated by vertical growth of the ramus, but in adults this extrusion tends to rotate the mandible downward and backward, that explain the significant correlation between ramus length and width with other angular and linear variables (table 3). al-hashimi and al-azawi (14) explain the positive relation between the a-p length of the atlas vertebra with each of ramus length and body length of mandible. so the increase a-p line length associated with increased ramus length, forward upward rotation of mandible, reduction of argome angle, reduction of go2 angle and reduction of mp-pp angle as in cl.iii, for that reason significant correlation found between cl.i and cl.iii and between cl.i and cl.ii (table 3). references 1. hans mg, enlow dh, noachtar r. age-related differences in mandibular ramus growth: a histologic study. angle orthod 1995; (5): 335-40. 2. björk a. mandibular rotation studied with the aid of metal implants. am j orthod 1970; 5: 448–54. 3. interviews: dr. donald h. enlow on craniofacial growth. j clin orthod 1983; 17(10): 669 79. 4. karlsen at. association between vertical development of cervical spine and the face in subjects with varying vertical facial pattern. am j orthod dentofac orthop 2004; 125(5): 597-606. 5. suri s, ross b, tompson b: mandibular morphology and growth with and without hypodontia in subjects with pierre robin sequence. am j orthod dentofac orthop 2006; 130(1): 37-46. 6. jassim es, al-daggistany ms, saloom je. a correlation between new angle (s-gn-go) with the j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry171 facial height. j bagh coll dentistry 2010; 22(3): 96100. 7. caufield pw. tracing technique and identification of landmarks. in jacobson a (ed). radiographic cephalometry from basics to video imaging. 1st ed. chicago: quintessence publishing co.; 1995. p. 60. 8. rakosi t. an atlas and manual of cephalometric radiography. 2nd ed. london: wolfe medical publications ltd.; 1982. 9. downs wb. the role of cephalometrics in orthodontic case analysis and diagnosis. am j orthod 1951; 38(3): 162-82. 10. steiner cc. cephalometrics for you and me. am j orthod 1953; 39 (10): 728-55. 11. björk a. the face in profile. an anthropological x-ray investigation on swedish children and conscripts. svensk tandläkare-tidskrift 1947; 40(5b) suppl. 12. downs wb. variations in facial relationships: their significance in treatment and prognosis. am j orthod 1948; 34(10): 812-40. 13. huang gj, justus r, kennedy db, kokich vg. stability of anterior openbite treated with crib therapy. angle orthod 1990; 60(1): 17-24. (ivsl). 14. al-hashimi ha, al-azawi zz. association of the atlas vertebra with the morphology of the mandible. must dent j 2008; 5(2): 194-9. 15. huggare j, kylämarkula s. morphology of the first cervical vertebra in children with enlarged adenoids. eur j orthod 1985; 7: 936. 16. yassir ay. ramus height and its relationship with various skeletal and dental measurements. j oral res 2013; 1(1): 2-5. 17. al-sahaf nh. cross-sectional study of cephalometric standards and associated growth changes. a master thesis, department of pop, college of dentistry, university of baghdad, 1991. 18. ali fa. skeletodental characteristics of some iraqi children at nine and ten years of age: a cephalometric study. a master thesis, department of pop, college of dentistry, university of baghdad, 1988. 19. al-attar am. the relationship between mandibular antegonial notch depth and craniofacial morphology in iraqi sample aged 18-25 years. a master thesis, department of pop, college of dentistry, university of baghdad, 2006. 20. al-joubori sk, yassir ya, al-bustani ai. the relation between ramus notch depth and some of the craniofacial measurements in different skeletal patterns. j bagh coll dentistry 2009; 21(4): 104-8. 21. tracy we, savara bs, brant jw. relation of height, width and depth of mandible. angel orthod 1965, 35(4): 269-77. 22. knott vb. growth of mandible relative to a cranial base line. angle orthod 1973, 43(3): 305-13. 23. björk a. prediction of mandibular growth rotation. angle orthod 1969; 55: 585-99. 24. andria lm, leite lp, prevatte tm, king lb. correlation of angle base angle and its components with other dental/skeletal variables and treatment time. angle orthod 2004; 74(3): 361-6. (ivsl). 25. nisayif dh. assessment of the relationship between the morphology of the first cervical vertebra and the direction of mandibular rotation. a master thesis, department of orthodontics, college of dentistry, university of baghdad, 2005. 26. karlsen at. association between facial height development and mandibular growth rotation in low and hight mp-sn angle faces: a longitudinal study. angle orthod 1997; 67 (2): 103-10. (ivsl). 27. bishara se. textbook of orthodontics. 1st ed. philadelphia: w.b. saunders company; 2001. 28. mclaughlin rp, bennett jc, trevisi hj. systemized orthodontic treatment mechanics. 1st ed. mosby international ltd; 2001. p. 132. 29. proffit wr, fields hw, sarver dm. contemporary orthodontics. 5th ed. mosby, inc., an affiliate of elsevier inc.; 2013. j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry172 table 1: descriptive statistics, gender difference and classes' difference of the linear measurements lsd test anova cl.iii cl.ii cl.i sex variable (mm.) ii-iii i-iii i-ii p-value f-test s.d. mean s.d. mean s.d. mean .075 2.814 2.76 71.56 3.02 70.06 2.63 72.93 male sn .597 .524 3.26 66.25 3.94 66.1 2.58 67.44 female 4.582 2.815 4.823 t-test .000 .010 .000 p-val. .258 1.415 6.24 121.57 8.03 122.24 6.1 119.80 male afh .312 1.206 7.6 111.9 6.5 113.5 5.9 109.13 female 3.606 2.988 1.142 t-test .001 .007 .002 p-val. .122 2.252 6.8 76.57 5.7 77.57 4.71 81.82 male pfh .816 .204 5.03 70.1 5.62 70.17 6.86 71.51 female 2.785 3.263 3.777 t-test .101 .003 .002 p-val. ns * (ns) .036 3.696 5.75 54.91 5.64 56.98 3.86 61.05 male co-go .781 .249 3.3 52.87 8.17 51.81 6.4 53.65 female 1.121 1.827 3.007 t-test .273 .081 .008 p-val. * ns * .049 3.329 5.95 82.35 3.94 77.53 6.93 83.16 male go-gn .181 1.800 5.6 76.75 4.98 72.87 5.09 74.44 female 2.515 2.587 3.151 t-test .019 .016 .006 p-val. .293 1.275 5.7 119.8 5.4 117.9 4.86 121.7 male co-gn * * ns .027 4.052 5.48 113.2 6.26 107.04 5.13 108.8 female 3.023 4.628 5.595 t-test .006 .000 .000 p-val. .342 1.110 3.001 29.26 15.3 34.6 2.51 30.52 male ramal width .849 .165 2.99 26.87 2.73 27.3 2.55 27.52 female 2.067 1.684 2.575 t-test .049 .016 .040 p-val. .317 1.190 1.25 10.89 1.3 10.53 2.01 10.53 male vent. length .126 2.211 1.23 10.2 2.55 11.55 1.57 10.13 female 1.443 -1.246 1.716 t-test .161 .225 .104 p-val. .927 .076 1.83 9.87 1.85 10.65 1.89 10.4 male dors length .938 .065 1.83 9.87 1.98 9.78 1.37 9.6 female 1.224 1.132 1.068 t-test .232 .269 .301 p-val. .452 .814 2.02 44.7 3.2 46.6 3.38 48.11 male a-p line .727 .322 2.02 44.7 3.6 43.86 3.46 44.72 female 3.786 2.019 2.157 t-test .100 .055 .046 p-val. j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry173 table 2: descriptive statistics, gender difference and classes' difference of the angular measurements lsd test anova cl.iii cl.ii cl.i sex variable (º) ii-iii i-iii i-ii p-value f-test s.d. mean s.d. mean s.d. mean .852 .162 5.9 122.14 4.45 121.0 4.82 121.78 male n-s-ar .909 .095 7.22 124.54 6.5 124.0 7.65 125.3 female -.949 -1.336 -1.185 t-test .352 .195 .252 p-val. .803 .221 6.29 145 5.13 146.5 5.9 145.4 male s-ar-go .064 2.995 7.84 141.9 7.06 148.85 8.75 142.6 female 1.129 -.944 0.820 t-test .269 .355 .423 p-val. .246 1.466 8.26 126.5 6.13 127.9 4.6 122.9 male s-ar go-me .555 .599 11.06 127.7 6.7 124.08 6.09 126 female -.319 1.489 -1.245 t-test .752 .150 .230 p-val. .505 .697 3.59 52.6 2.9 51.58 2.22 51.2 male go.1 ** ns * .014 4.902 4.31 53.85 3.48 49.38 3.44 52.9 female -.790 1.707 -1.244 t-test .437 .101 .230 p-val. .234 1.519 6.38 74.14 6.05 76.08 3.93 71.67 male go.2 .857 .155 8.67 73.77 5.56 74.77 9.3 73.3 female .128 .566 -0.905 t-test .899 .577 .378 p-val. ns ns * .046 3.408 3.46 67 3.48 68.9 3.46 64.78 male y-axis * ns * .029 3.947 6.03 66.7 2.41 70.85 3.01 66.6 female .164 -1.516 -1.156 t-test .871 .143 .264 p-val. .205 1.667 7.12 33.78 6.3 35.25 4.04 30.33 male sn-mp .495 .718 10.2 33.85 5.53 36.92 5.44 33.7 female -.018 -.707 -1.514 t-test .986 .487 .148 p-val. .080 2.738 3.27 6.64 3.02 3.75 3.3 4.78 male sn-pp .545 .617 4.14 6.46 3.71 7.7 2.15 6.2 female .127 -2.901 -1.123 t-test .900 .008 .277 p-val. .071 2.870 5.76 27.14 7.41 31.67 5.05 25.56 male pp-mp .761 .276 9.77 27.3 6.79 29.38 5.68 27.5 female -.054 .803 -0.784 t-test .957 .430 .444 p-val. j bagh college dentistry vol. 26(4), december 2014 the relation among ramal pedodontics, orthodontics and preventive dentistry174 table 3: the relation among the ramal length and width with the cervical and cranio-facial measurements in both genders of different skeletal classes variables cl.i cl.ii cl.iii female male female male female male length width length width length width length width length width length width n-s-ar r 0.57 -0.02 0.11 -0.01 -0.15 0.16 0.36 0.33 -0.12 -0.21 -0.21 0.51 p 0.08 0.95 0.79 0.97 0.62 0.6 0.25 0.29 0.69 0.49 0.47 0.06 s-ar-go r -0.53 -0.17 -0.11 0.19 -0.31 -0.2 -0.37 -0.03 0.27 0.26 0.08 -0.33 p 0.11 0.64 0.78 0.62 0.3 0.51 0.24 0.92 0.37 0.39 0.79 0.26 ar-go-me r -0.69 -0.2 -0.24 -0.71 0.07 -0.21 -0.18 -0.29 -0.63 -0.51 -0.36 -0.25 p 0.03 0.58 0.53 0.03 0.82 0.49 0.57 0.35 0.02 0.07 0.21 0.4 go1 r -0.34 0.06 -0.51 -0.05 0.18 0.02 -0.41 0.15 -0.52 -0.15 -0.37 0.06 p 0.34 0.86 0.16 0.89 0.56 0.96 0.19 0.65 0.07 0.62 0.2 0.83 go2 r -0.81 -0.39 0 -0.8 -0.07 -0.25 0 -0.35 -0.54 -0.58 -0.24 -0.36 p 0.000 0.26 0.99 0.01 0.82 0.41 0.99 0.26 0.05 0.04 0.41 0.2 y-axis r -0.14 -0.37 0.27 -0.57 -0.59 -0.09 0.24 -0.12 -0.49 -0.5 -0.25 0 p 0.71 0.29 0.49 0.11 0.03 0.77 0.45 0.71 0.09 0.08 0.39 0.99 sn-mp r -0.78 -0.47 -0.31 -0.51 -0.52 -0.34 -0.24 -0.07 -0.53 -0.5 -0.56 -0.17 p 0.01 0.17 0.42 0.16 0.07 0.26 0.46 0.82 0.06 0.08 0.04 0.55 sn-pp r 0.11 -0.46 0.35 -0.09 -0.19 -0.14 0 0.2 -0.55 -0.25 -0.16 -0.13 p 0.77 0.18 0.36 0.82 0.53 0.66 1 0.53 0.05 0.4 0.59 0.67 mp-pp r -0.82 -0.27 -0.47 -0.35 -0.32 -0.14 -0.2 -0.15 -0.33 -0.41 -0.58 -0.14 p 0.000 0.45 0.2 0.35 0.29 0.64 0.54 0.64 0.27 0.16 0.03 0.63 sn r 0.34 -0.1 -0.24 0.8 0.05 -0.19 -0.13 -0.14 0.13 0.6 0.21 0.64 p 0.34 0.78 0.54 0.01 0.88 0.54 0.68 0.67 0.67 0.03 0.48 0.01 afh r 0.28 -0.13 0.57 -0.37 -0.06 -0.22 0.38 -0.48 -0.22 -0.23 -0.03 0.18 p 0.43 0.72 0.11 0.32 0.86 0.47 0.23 0.11 0.47 0.45 0.92 0.54 pfh r 0.94 0.37 0.9 -0.11 0.6 0.14 0.94 -0.61 0.61 0.45 0.78 0.26 p 0.000 0.3 0.000 0.79 0.03 0.65 0.000 0.04 0.03 0.12 0.000 0.38 go-gn r 0.27 0.13 -0.16 0.85 -0.25 -0.06 -0.29 0.08 0.72 0.62 -0.22 0.49 p 0.45 0.73 0.68 0.000 0.42 0.84 0.36 0.81 0.01 0.02 0.46 0.07 co-gn r 0.74 0.41 0.3 0.52 0.3 -0.1 0.71 -0.66 0.61 0.46 0.07 0.3 p 0.02 0.24 0.44 0.15 0.32 0.75 0.01 0.02 0.03 0.11 0.81 0.29 vent length r 0.15 -0.37 0.11 0.73 -0.37 0.22 0.5 -0.53 0.36 -0.15 -0.05 0.21 p 0.67 0.29 0.79 0.02 0.21 0.46 0.1 0.08 0.23 0.64 0.87 0.47 dors length r -0.06 0.19 -0.29 0.15 0.08 -0.03 0.06 -0.43 0.12 -0.2 0.16 0.37 p 0.86 0.59 0.45 0.69 0.8 0.92 0.86 0.16 0.7 0.5 0.59 0.19 a-p line r 0 -0.23 0.55 0.13 0.07 -0.4 0.05 -0.33 0.27 0.12 -0.62 0.38 p 1 0.53 0.12 0.75 0.83 0.18 0.87 0.29 0.37 0.7 0.02 0.19 r. length r 0.46 -0.34 0.08 -0.55 0.57 0.11 p 0.18 0.36 0.79 0.06 0.04 0.7 30. zaid f.doc j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 180 the effect of acceledent® device on both gingival health condition and levels of salivary interleukin-1βeta and tumor necrosis factors-alpha in patients under fixed orthodontic treatment zaid saadi hasan ahmed, b.d.s., m.sc., ph.d. (1) noor saadi hasan ahmed, b.d.s., m.sc. (2) nidhal h. ghaib, b.d.s., m.sc. (3) abstract background: traditional orthodontic treatment takes a long time and this may lead to several disadvantages like higher predisposition to periodontal diseases and dental caries. recently, many researchers focus on shorter orthodontic treatment time through different methods like the use of: vibration, surgical approach, adjunctive medicine, laser and others. this study aimed to determine the effect of acceledent vibration device on the gingival health condition and the changes in levels of salivary il-1β and tnfα among patients under fixed orthodontic appliance during orthodontic treatment. material and methods: a total of 32 adult patients with an age ranged between 19-23 years were participated in this study. they were divided into two groups: 14 patients under fixed orthodontic appliance with the use of acceledent vibration device as study group and 18 patients under fixed orthodontic appliance only as control group. all patients were with class i and /or class ii malocclusion cases requiring bilateral extraction of their maxillary first premolar teeth, underwent a session of professional oral hygiene and received oral hygiene instructions before and during the period of study. the collection of the unstimulated salivary samples from the individuals was performed at different times after placement of the fixed orthodontic appliance; base line (t0), after 1 hour (t1), after one week (t2), after two week (t3). the levels of salivary il-1β and tnf-α were estimated by using commercially available elisa kits. oral cleanliness were determined by using of gingival index (gi) and plaque index (pi). results: for both study and control groups, results reported that the mean value of salivary il-1-β (pg/ml) and tnf-α (pg/ml) were highest at t1, followed by t2, then t3 and lowest t0 with highly statistically significant difference (p<0.01).the mean value of both salivary il-1-β (pg/ml) and tnf-α (pg/ml) among study group were higher than control group at t1, followed by t2, then t3 with statistically significant difference (p<0.05). among study group only, results of this study recorded a negative direction correlation between both il-1-β (pg/ml) and tnf-α (pg/ml) and gingivitis at the (t2 and t3) and (t3) with statistically highly significant and significant respectively. conclusion: the application of acceledent device play important role in improving the gingival health condition and increasing the levels of salivary il-1β and tnf-α secretion among patients under fixed orthodontic appliance in comparison to other under fixed orthodontic appliance. keywords: acceledent, fixed orthodontic appliance, salivary il-1β, tnf-α. (j bagh coll dentistry 2015; 27(4):180-187). introduction orthodontic tooth movement (otm) is generated by the coupling of bone resorption on the compressed side of the periodontal ligament (pdl) and through bone formation on the stretched side of the pdl as a consequence of therapeutic mechanical stress (1). mechanical stress from fixed orthodontic appliances is believed to induce cells in the periodontal ligament (pdl) to form biologically active substances, such as enzymes, cytokines such as interleukin-1(il-1β and il-1α), (il-6), and receptor activator for nuclear factor b ligand (rankl) which are inflammatory mediators or proinflammatory remodelers of the (pdl) responsible. and for connective tissue remodeling, rankl is reportedly essential to the osteoclast formation, function, and survival (2,3). (1)lecturer. ministry of higher education and scientific research. studies & planning & follow up office. manager of curriculum. (2)assist. lecturer. department of biochemistry. college of medicine. university of baghdad. (3)professor. department of orthodontic. college of dentistry. university of baghdad. cytokines play important role in bone remodeling and they are involved in initiating, amplifying, perpetuating, and resolving inflammatory responses. both the il-1β and tnf α are inducing vascular dilatation which increased permeability and enhancing inflammatory response (4). by using already available oral hygiene instrument that uses electric power to generate oscillatory pattern, which in term create the vibration motion result in up-regulation of the mechanical signal for alveolar bone remodeling(5). studies reported a greater incidence of gingivitis among orthodontic treatment patients, this may be due to the mechanical and chemical irritation of orthodontic bands and plaque control level (6,7). since orthodontic treatment usually takes place over a long period of time and the dental problems of both periodontal disease and dental caries are burdensome for the patient. in comparison to the invasive methods, new acceledent vibration device has been introduced in orthodontic field as non-invasive method with minimal side effects like periodontal diseases and j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 181 orofacial pain, to accelerating tooth movement and has proven to be a safe low impact alternative that enhances bone remodeling in the medical field (3,8). the present study can be represented as a first iraqi study that deals with the effect of using acceledent vibration device on gingival health condition and levels of salivary il-1-β and tnf-α among patients with fixed orthodontic appliance during orthodontic treatment. the current study aimed to determine the effect of acceledent vibration device on the gingival health condition and the changes in levels of salivary il-1β and tnfα among patients with fixed orthodontic appliance during orthodontic treatment. materials and methods dental and laboratory materials they involved the diagnostic instruments (dental mirror, dental tweezers, dental probe), cotton roll, kidney dish, portable saliva ejector machine, alginate impression materials, dental stone centrifuge, disposable test tube, eppendroffs tubes (0.25ml, 1ml, and 2ml), eliza kits, glass pasteur pipettes, bracket holder, tucker, light cutter, and super looper pliers. orthodontic materials: • 0.014 inch light, round, nickel titanium arch wire (orthotechnology). • 0.018 x 0.022 inch, stainless steel bracket (orthotechnology). • molar tube for maxillary first molar right and left (orthotechnology). • ligature wire (orthotechnology). • light cure composite and bonding (orthotechnology). sample and methods: the sample of the present study involved thirty two iraqi volunteers aged 19-23 years old under orthodontic treatment and they were divided into control group (which included subject under fixed orthodontic appliance only) and study group (which included subject under fixed orthodontic appliance with the use of acceledent vibration device (figure 1). moreover, this device used at time (10:00 am) after selection of proper tray for each subject in study group and based it on delivery of high frequency vibration (30hz) to the teeth for approximately 20 minutes continuously per day(9). figure (1): acceledent vibration device to be eligible for the study, all subjects were selected according to the following criteria: they should be with class i and /or class ii malocclusion cases requiring bilateral extraction of their maxillary first premolar teeth. they should have no history of previous orthodontic and facial surgical treatments, smoking, pregnancy, lactation, dental caries, pulp pathology, periodontal disease and history of systemic disease. each subject prior the placement of the fixed orthodontic appliance should extracted both upper first premolars (right and left) at least before 20 days. during this period, all the subjects were instructed to maintain good oral hygiene regime through checking of plaque index pi, gingival index gi (10-12). following these 20 days the complete fixed appliance was placed on the upper arch only by bonding the teeth including from the upper second premolar of one side to the second premolar on the other side of the same arch in addition of bonding the upper first molar of both side by molar tube. the collections of the whole unstimulated salivary samples from the volunteer were formed under standardized conditions. the person should not eat or drink except water one hour before sample collection. the person should not smoke or undergo heavy physical stress before collection. the person should sit in a relaxed position on an ordinary chair and the samples containing blood should be discarded if chemical analysis of saliva is planned (13,14). in this study three milliliter of whole unstimulsted saliva were collected into a sterile plastic tube between 9-12 am at different stages of time; before placement of the fixed orthodontic appliance as a baseline (t0), then 1 hour after placement of orthodontic appliance (t1), one week (t2), two week (t3). j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 182 the samples were stored at -20ºc in a deep freeze until processed (15). then the saliva were centrifuged at 3000 rpm for 10 minutes, the supernatants layer were collected and frozen until processed. the levels of salivary il-1β and tnf α were estimated by using commercially available elisa kits following the manufactures' instructions. at different time (t0), (t2), (t3), the oral cleanliness were determined using gingival index (gi) and plaque index (pi). all data of analyses were performed by using the spss statistical software program (version 10 for windows, spss). results table 1 illustrated the mean and standard deviation values of plaque index among study and control groups. for both study and control groups, the results showed that the mean values of plaque index were higher at t3 with no significant difference (p>0.05) among total sample and both males and females. concerning study group, results showed that the mean value of plaque index among males was higher than females with significant difference (p<0.05) at t3 only while it was not significant at t0 and t2. among control group, the same results were recorded but with no significant difference (p>0.05) at t3, t2 and t0. the mean values of gingival index among study and control groups are shown in table 2. concerning study group, results showed that the mean value of gingivitis was lowest at t3 with highly significant difference (p<0.01) among total sample and both males and females. the same results was recorded concerning control group while with no significant difference (p>0.05) among total sample and both males and females. according to the t-test for study group, the mean values of gingival index among males was higher than females with significant difference (p<0.05) at t2 and t3 while it was not significant for t0. while for control group, no gender difference was recorded for t1, t2 and t3. table (1): mean of plaque index among study and control groups groups gender no. base line (t0) after 1 week (t2) after 2 week (t3) anova test mean sd t-test mean sd t-test mean sd t-test t p t p t p f p study males 6 0.52 0.13 0.802 0.441 0.50 0.16 0.946 0.367 0.69 0.11 2.487 0.032 * 1.74 0.217 females 8 0.46 0.11 0.42 0.15 0.44 0.20 0.08 0.969 total 14 0.48 0.12 0.45 0.15 0.54 0.21 0.24 0.871 control males 8 0.54 0.09 1.947 0.073 0.59 0.12 1.799 0.095 0.63 0.14 1.650 0.123 0.57 0.644 females 10 0.40 0.15 0.42 0.21 0.44 0.25 0.05 0.985 total 18 0.46 0.14 0.49 0.20 0.52 0.23 0.57 0.839 * (significant) = p value<0.05 (within group) table (2): mean of gingival index among study and control groups groups gender no. base line (t0) after 1 week (t2) after 2 week (t3) anova test mean sd t-test mean sd t-test mean sd t-test t p t p t p f p study males 6 0.65 0.10 1.641 0.132 0.34 0.09 2.484 0.032 0.07 0.04 -2.304 0.044 * 39.71 0 females 8 0.55 0.11 0.20 0.10 0.16 0.08 20.44 0 total 14 0.59 0.12 0.26 0.12 0.13 0.08 40.18 0 control males 8 0.66 0.09 1.947 0.073 0.59 0.12 2.154 0.051 0.56 0.21 1.290 0.220 0.38 0.772 females 10 0.52 0.15 0.39 0.21 0.41 0.24 0.75 0.535 total 18 0.58 0.14 0.47 0.20 0.47 0.23 0.97 0.419 * (significant) = p value<0.05 (within group), ** (highly significant) = p value<0.01 (within group) data of the present study for both study and control groups showed that the mean value of salivary il-1-β (pg/ml) and tnf-α (pg/ml) were highest at t1, followed by t2, then t3 and t0 with highly statistically significant difference (p<0.01) among total sample and both males and females as shown in tables 3 and 4 respectively. according to the t-test, the mean value of salivary il-1-β (pg/ml) among males was higher than females with no significant difference (p>0.05) at t0, t1, t2 and t3. the same results were recorded concerning tnf-α (pg/ml). the mean value of both salivary il-1-β (pg/ml) and tnf-α (pg/ml) among study group were higher than control group at t1, followed by t2, then t3 with statistically significant difference (p<0.05). the correlation coefficient (r) between il-1β concentration (pg / ml) and plaque and gingival indices among study and control group are shown in table 5. concerning study group after one week j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 183 (t2) and two week (t3), results reported that the correlation coefficient between il-1β concentration and gingival index were significant in negative direction for males. and among total and females the correlation was highly significant with negative direction. concerning study group at base line, data analysis reported no significant correlation between il-1β concentration and gingival index. concerning control group at base line (t0), after one week (t2) and two week (t3), results reported that the correlation coefficient between tnf-α (pg/ml) and both plaque and gingival indices were not significant in negative direction for total and both gender. table 6 illustrated the correlation coefficient (r) between tnf-α concentration (pg / ml) and plaque and gingival indices among study and control group. concerning study group after two week (t3), results reported that the correlation coefficient between tnf-α (pg/ml) concentration and gingival index were significant in negative direction for total and females. among males the correlation was not significant with negative direction. concerning study group at base line and after one week (t2), data analysis reported no significant correlation between tnf-α (pg/ml) concentration and gingival index. concerning control group at base line (t0), after one week (t2) and two week (t3), results reported that the correlation coefficient between tnf-α (pg/ml) and both plaque and gingival indices were not significant in negative direction for total and both gender. discussion many researchers have been utilized to increase rate of orthodontic tooth movement, whether it be by reducing friction in the fixed orthodontic appliances (16), surgical corticotomy techniques (17), adjunctive medicinal or hormonal therapies (local or systemic) such as pharmacological approaches with the injection of prostaglandin e2 (pge2) and 1,25-(oh)2d3 (18), physical approaches with low-energy laser irradiation (19) and magnetic fields (20). moreover, previous researches into these strategies revealed some disadvantages involving increase discomfort for patients, local pain and root resorption. recently as a new developed technology, acceledent device introduced in orthodontic treatment and act to accelerate the rate of orthodontic tooth movement and reduce treatment time to reach up to 30-40% (3,21) in addition to diminish adverse effects on oral health conditions in compare to previous techniques. in general, changes in il-1β profile of salivary form pressure site elicit the bone resorbing pattern which comes from orthodontic tooth movement(22-24). for both study and control group, data reported a gradual elevated significantly of il-1β and tnf-α at t1 followed with obvious decrease afterward at t2 then t3 this might indicated an early upregulation activity of the antiinflammatory cytokines such as il-10, including suppression of the proinflamatory cytokines and stimulation that play a role in bone resorption and periodontal tissue destruction(25); the finding of present study is in agreement with other studies(26-28). while disagreement with (29-30) who were representing no change, this may be as a result of the differences in the design of study involving sample size, age group, gender and type of salivary sample, especially when many of these studies did not included these factors in the multivariate analysis. results reported a higher il-1β level among study group than control group at t1, t2 and t3, this could be due to a lack of additional force consistency of acceledent vibration device among control group in comparison to study group (31). with respect to the rate of tooth movement, there is a study that found a positive correlation with the il-1β il-1 receptor antagonist ratio. furthermore, this study reported that the mean values of il-1β were higher among study group than control group; this may reflect the possible function of more il-1β secretion as a consequence of vibratory stimulation beside the conventional orthodontic force (32-33). among both study and control group, results of present study reported no gender differences concerning il-1β and tnf-α at t1, t2 and t3, this finding in agreement with serra et al. (34); this may be due to no differences in enzymatic activity during orthodontic tooth movement between males and females. in present study, the vibration of acceledent device has reduced or eliminated the invasive nature to achieve the regional acceleratory phenomenon that come with additional advantages such as reduced rates of: relapse, orthodontic pain and root resorption. moreover, the fluctuation of salivary il-1β and tnf-α during orthodontic tooth movement are only partly due to changes in the severity of gingival inflammation and this can be rationalize by the transport of them from the gingival sites (35-36). among study group only, results of this study recorded a negative direction correlation between both il-1-β (pg/ml) and tnf-α (pg/ml) and gingivitis at the (t2 and t3) and (t3) with statistically highly significant and significant respectively, this in agreement with the previous studies (37-38), while disagree with dinarello (39), these finding were in similarity to the j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 184 effectiveness of vibration magnitude of the toothbrush on reducing the severity of gingivitis (40).while among control group, results of this study recorded no correlation between both il-1β (pg/ml) and tnf-α (pg/ml) and gingivitis at t1 , t2 and t3, this may be due to lack additional consequence of vibratory stimulation beside the conventional orthodontic force. as conclusion; the use of acceledent device during fixed orthodontic treatment was found to be the effective method in decrease the severity of gingivitis and markedly increase in level of salivary both il-1-β (pg/ml) and tnf-α (pg/ml) during first 3 weeks of orthodontic treatment period. further studies with large sample size, among different age group and full duration of orthodontic treatment are necessary to get more clear and obvious results of acceledent device effect in reducing both treatment time and enhancing oral health conditions of patients. references 1. segal gr, schiffman ph, tuncay oc.meta analysis of the treatment-related factors of external apical root resorption. orthod craniofac res 2004; 7: 71-8. 2. nishijima y, yamaguchi m, kojima t, aihara n, nakajima r, kasai k. levels of rankl and opg in gingival crevicular fluid during orthodontic tooth movement and effect of compression force on releases from periodontal ligament cells in vitro. orthod craniofac res 2006; 9: 63–70. 3. nishimura m, chiba m, ohashi t, sato m, shimizu y, igarashi k, et al. periodontal tissue activation by vibration: intermittent stimulation by resonance vibration accelerates experimental tooth movement in rats. am j orthod dentofacial orthop 2008; 133(4): 572-83. 4. stoycheva ms, murdjeva ma. correlation between serum levels of interleukin 1-β, interleukin 1-ra, interleukin-6, interleukin 10, interleukin 12, tumor necrosis factor-α and interferonwith some clinical and laboratory parameters in patients with salmonellosis. biotechnol biotechnol equip 2005; 19: 143-6. 5. sumphan s. change in rate of orthodontic tooth movement and interleukin – 1 beta level in gingival crevcular fluid in respone to mechanical vibratory stimulation from electric toothbrush. a master thesis in oral health sciences, songkla university, 2009. 6. bellamine m1, ousehal l, kissa j. orthodontic treatment and gingival hyperplasia: a case report. odontostomatol trop 2012; 35(138): 31-41. 7. closs lq, bortolini lf, dos santos-pinto a, rösing ck. association between post-orthodontic treatment gingival margin alterations and symphysis dimensions. acta odontol latinoam 2014; 27(3): 125-30. 8. liu d, et al. acceleration of orthodontic tooth movement by mechanical vibration. 2010 aadr annual meeting washington d.c. 9. kau ch. a radiographic analysis of tooth morphology following the use of a novel cyclical force device in orthodontics. head face med 2011; 7: 14. 10. löe h, silness j. periodontal disease in pregnancy. acta odontol scand 1963; 21: 533-51. 11. silness j, löe h. periodontal disease in pregnancy. ii. correlation between oral hygiene and periodontal condition. acta odontol scand; 1964: 22:121-35. 12. capelli j jr, kantarci a, haffajee a, teles rp, fidel r jr, figueredo cm. matrix metalloproteinases and chemokines in the gingival crevicular fluid during orthodontic tooth movement. eur j orthod 2011; 33(6): 705-11. 13. tenovuo j, lagerlöf f. saliva. in thylstrup a and fejerskov o. (eds). textbook of clinical cardiology. 2nd ed. copenhagen: munksgard; 1996. p. 17-43. 14. farsi nma. signs of oral dryness in relation to salivary flow rate, ph, buffering capacity and dry mouth complaints. bmc oral health 2007; 7:15. 15. fabrício ta, tânia mp, tálita pm, evandro na, maria cf, antônio l, arthur mk, mauro hng, tarcília a. burning mouth syndrome. headache 2012; 52(6):1026-34. 16. henao sp, kusy rp. evaluation of the frictional resistance of conventional and self-ligating bracket designs using standardized archwires and dental typodonts. angle orthod 2004; 74: 202-11. 17. wilcko wm, wilcko t, bouquot je, ferguson dj. rapid orthodontics with alveolar reshaping: two case reports of decrowding. inter j periodontics restorat dentistry 2001; 21: 9-19. 18. bartzela t, turp jc, motschall e, maltha jc. medication effects on the rate of orthodontic tooth movement: a systematic literature review. am j orthod dentofac orthop 2009; 135: 16-26. 19. kawasaki k, shimizu n. effects of low-energy laser irradiation on bone remodeling during experimental tooth movement in rats. lasers surg med 2000; 26: 282-91. 20. tengku bs, joseph bk, harbrow d, taverne aa, symons al. effect of a static magnetic field on orthodontic tooth movement in the rat. eur j orthod 2000; 22: 475-87. 21. shenava s, krishna nayak u s, bhaskar v, nayak a. accelerated orthodontics – a review. inter j scientific study 2014; 1(5): 35-9. 22. dudic a, killiaridis s, mombelli a, giannopoulou c. composition changes in gingival crevicular fluid during orthodontic tooth movement: comparisons between tension and compression sides. eur j oral sci 2006; 114(5): 416-22. 23. krishnan v, davidovitch z. cellular, molecular, and tissue-level reactions to orthodontic force. am j orthod dentofac orthop 2006; 129(4): 469–e1-32. 24. meikle mc. the tissue, cellular, and molecular regulation of orthodontic tooth movement: 100 years after carl sandstedt. eur j orthod 2006; 28(3): 22140. 25. hirose m, ishihara k, saito a, nakagawa t, yamada s, okuda k. expression of cytokines and inducible nitric oxide synthase in inflamed gingival tissue. j periodontol 2001; 72(5): 590-7. 26. dudic a, killiaridis s, mombelli a, giannopoulou c. composition changes in gingival crevicular fluid during orthodontic tooth movement: comparisons between tension and compression sides. eur j oral sci 2006; 114(5): 416-22. 27. giannopoulou c, dudic a, kiliaridis s. pain discomfort and crevicular fluid changes induced by j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 185 orthodontic elastic separators in children. j pain 2006; 7(5): 367-76. 28. filiz ak, nihal h, guvenc b, mehmet d, tuba ty. tnf-α, il-1β and il-8 levels in tooth early leveling movement orthodontic treatment. j inter dent med res 2010; 3(3):116-21. 29. uematsu s, mogi m, deguchi t. interleukin (il)-1 beta, il-6, tumor necrosis factor-alpha, epidermal growth factor, and beta 2-microglobulin levels are elevated in gingival crevicular fluid during human orthodontic tooth movement. j dent res 1996; 75(1):562-7. 30. iwasaki lr, haack je, nickel jc, reinhardt ra, petro tm. human interleukin-1b and interleukin -1 receptor antagonist secretion and velocity of tooth movement. archive oral biol 2001; 46:185-9. 31. lee kj, park yc, yu hs, choi sh, yoo yj. effects of continuous and interrupted orthodontic force on interleukin-1 and prostaglandin e2 production in gingival crevicular fluid. am j orthod dentofac orthop 2004; 125(2):168-77. 32. nukaga j, kobayashi m, shinki t, song h, takada t, takiguchi t, et al. regulatory of interleukin-1beta and prostaglandin e2 on expression of receptor activator of nuclear factor-kappa b ligand in human periodontal ligament cells. j periodontol 2004; 75: 249-59. 33. wei s, kitaura h, zhou p, ross fp, teitelbaum sl. il-1 medates tnf-induced osteoclastogenesis. j clin invest 2005; 115: 282-90. 34. serra e, perinetti g, d'attilio m, cordella c, paolantonio m, festa f, spoto g. lactate dehydrogenase activity in gingival crevicular fluid during orthodontic treatment. am j orthod dentofac orthop 2003; 124(2): 206-11. 35. higashi y, goto c, jitsuiki d, et al. periodontal infection is associated with endothelial dysfunction in healthy subjects and hypertensive patients. hypertension 2008; 51(2): 446-53. 36. giannobile wv, beikler t, kinney js, et al. saliva is as a diagnostic tool for periodontal disease current state and future directions. j periodontal 2009; 50: 5264. 37. ide m, jagdev d, coward p, crook m, barclay g, wilson r. the short-term effects of treatment of chronic periodontitis on circulating levels of endotoxin, c-reactive protein, tumor necrosis factor alpha, and interleukin-6. j periodontal 2004; 75(3): 420-8. 38. nibali l, d'aiuto f, griffiths g, patel k, suvan j, tonetti m. severe periodontitis is associated with systemic inflammation and a dysmetabolic status: a case control study. j clin periodontal 2007; 34(11): 931-7. 39. dinarello ca. interleukin 1 and its biologically related cytokines. adv immunol 1989; (44):153-205. 40. lea sc. in-vitro analysis of powered toothbrush vibrations. dental health 2007; 46(4): 5-8. j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 186 appendices: table (3): mean of il-1β concentration (pg / ml) among study and control groups groups genders base line (t0) after 1hour (t1) after 1 week (t2) after 2 week (t3) anova test no. mean sd t-test mean sd t-test mean sd t-test mean sd t-test tvalue sig tvalue sig tvalue sig tvalue sig f sig study males 6 161.32 3.98 2.108 0.061 462.78 10.23 1.549 0.152 275.47 6.37 1.098 0.298 247.48 5.75 1.166 0.271 718.885 0 females 8 152.60 8.51 448.63 18.33 267.76 14.58 240.55 12.23 259.239 0 total 14 156.23 8.09 454.52▲ 16.57 270.97▲ 12.10 243.44▲ 10.31 602.696 0 control males 8 161.02 6.31 1.613 0.131 437.17 22.65 1.207 0.249 259.42 11.53 1.704 0.112 233.78 10.51 1.409 0.182 414.656 0 females 10 156.68 4.16 422.40 23.57 251.09 7.53 227.23 7.58 665.879 0 total 18 158.41 5.38 428.30 23.60 254.42 9.89 229.85 9.12 1026.266 0 table (4): mean of tnfα concentration (pg / ml) among study and control groups groups genders base line (t0) after 1hour (t1) after 1 week (t2) after 2 week (t3) anova test no. mean sd t-test mean sd t-test mean sd t-test mean sd t-test tvalue sig tvalue sig tvalue sig tvalue sig f sig study males 6 2.02 0.02 -0.101 0.921 6.09 0.11 -1.219 0.251 3.66 0.30 -1.198 0.259 3.04 0.02 0.407 0.693 8893.394 0 females 8 2.03 0.17 6.55 0.84 3.86 0.28 3.04 0.02 2541.076 0 total 14 2.02 0.12 6.36▲ 0.67 3.77▲ 0.29 3.04▲ 0.02 5870.361 0 control males 8 2.02 0.04 -0.057 0.956 5.59 0.18 -1.203 0.250 3.65 0.07 0.473 0.644 2.92 0.05 -0.462 0.652 2874.095 0 females 10 2.02 0.07 5.75 0.30 3.63 0.10 2.94 0.08 7817.294 0 total 18 2.02 0.05 5.69 0.26 3.64 0.09 2.93 0.07 9199.709 0 table (5): correlation coefficient (r) between il-1β concentration (pg / ml) and plaque and gingival indices among study and control groups genders no. base line (t0) after 1 week (t2) after 2 week (t3) plaque index gingival index plaque index gingival index plaque index gingival index r p-value r p-value r p-value r p-value r p-value r p-value males 6 0.188 0.762 -0.495 0.396 -0.644 0.241 -0.898 0.038* -0.23 0.71 -0.871 0.032* females 8 0.303 0.509 0.567 0.185 -0.489 0.266 -0.903 0.005** -0.256 0.579 -0.911 0.001** total 14 0.314 0.321 0.432 0.161 -0.314 0.32 -0.762 0.004** -0.087 0.789 -0.902 0.009** males 8 0.417 0.411 0.417 0.411 0.276 0.596 0.276 0.596 0.306 0.556 0.366 0.475 females 10 0.121 0.756 0.121 0.756 0.083 0.831 0.135 0.73 0.074 0.849 0.123 0.752 total 18 0.36 0.187 0.36 0.187 0.298 0.28 0.347 0.205 0.27 0.33 0.319 0.247 j bagh college dentistry vol. 27(4), december 2015 the effect of pedodontics, orthodontics and preventive dentistry 187 table (6): correlation coefficient (r) between tnfα concentration (pg / ml) and plaque and gingival indices among study and control groups genders no. base line (t0) after 1 week (t2) after 2 week (t3) plaque index gingival index plaque index gingival index plaque index gingival index r p-value r p-value r p-value r p-value r p-value r p-value males 6 0.123 0.843 -0.639 0.246 -0.616 0.268 -0.485 0.407 -0.143 0.818 -0.673 0.021* females 8 0.296 0.519 0.582 0.171 -0.413 0.357 -0.541 0.21 -0.308 0.502 -0.822 0.023* total 14 0.309 0.328 0.447 0.145 -0.352 0.261 -0.334 0.289 -0.25 0.434 -0.661 0.019* males 8 0.419 0.408 0.419 0.408 0.238 0.65 0.238 0.65 0.391 0.443 0.593 0.215 females 10 0.122 0.754 0.122 0.754 0.531 0.142 0.537 0.136 0.38 0.313 0.328 0.388 total 18 0.342 0.211 0.342 0.211 0.266 0.337 0.232 0.405 0.399 0.141 0.412 0.127 dropbox shams-f .pdf simplify your life j bagh college dentistry vol. 29(1), march 2017 a study to compare restorative dentistry 27 a study to compare the internal fitness and marginal gap between single crowns and crowns within three-unite bridge of zirconia substructure fabricated by cad-cam system. (an in vitro study) auday m. asady b.d.s (1) haitham j al azzawi b.d.s., m.sc. (2) abstract purpose: the aim of this in vitro study was to compare the marginal gap and internal fitness between single crowns and the crowns within three-unit bridges of zirconium fabricated by cad-cam system. materials and methods: a standard model from ivoclar company was used as a pattern to simulate three-units bridge (upper first molar and upper first premolar) as abutments used to fabricate stone models, eight single crowns for premolar and eight of three units bridges. crowns and bridges fabricated by cad-cam system were cemented on their respective stone models then sectioned at the mid-point buccolingaully and misiodistaly and examined under stereomicroscope. result: the marginal gap in premolar crowns and premolar within bridge were within the acceptable value 120µm, one –way anova showed that there was significant differences in the internal gaps among the areas. independent ttest showed there was significant differences between the premolar crowns and premolar crowns within bridges in marginal opening and cusp tip (lingually and distally) conclusion: the marginal and internal gaps were in the bridge higher than those in the crowns. the areas of sloped surfaces such as chamfer area, occlusal area and cusp tip had high gap values in comparison with areas of flat surfaces such as axial wall and when the surface area of abutment increased, the marginal and internal gaps of abutment was increase. keywords: marginal fitness, internal fitness, cad-cam system, zirconia (j bagh coll dentistry 2017; 29(1):27-31) introduction all ceramic restorations can be used as a good alternative to the metalceramic restoration, especially with increasing the expectation to the esthetic restoration in addition to that, good mechanical properties and biocompatibility of ceramic restoration. marginal and internal fit of restoration are factors to success , any discrepancy in margin led to secondary caries formation , periodontal destruction , pulpal irritation and dissolution of luting agent so that misfit reduce the longevity of restoration(1) . nowadays, a high strength zirconia used in fpd even in load bearing area (2,3), which is present in either partially sintered or fully sintered zirconia and it is stronger than other types of ceramic such as lithium disilicate – reinforced glass ceramic.(4) the evolution and development of cad-cam system added to the dentist new and fast treatment modalities in the fixed partial denture aspect. the cad-cam system presented to scan, design and mill the fixed prosthesis. (1) babylon health directory, ministry of health, babylon, iraq. (2) professor, conservative department, college of dentistry, university of baghdad, baghdad, iraq. cad-cam machining for construction of dental restorations are gaining popularity and are clinically proven. (5) materials and methods sample description: standard model from (ivoclar company) was used as a pattern for construction stone model to simulate three – unite bridge (the maxillary first molar and maxillary first premolar) as abutment and (the maxillary second premolar missed). the reduction of the abutments were 1.5 mm of the occlusal surface and 1.2 mm of the axial according to the ivoclar prepared guide with chamfer finishing line all around to receive full coverage zirconium crowns (fig. 1). the same model was used to fabricate both the single premolar crowns and premolar crowns within bridges. figure 1: model from ivoclar with prepared maxillary first molar and maxillary first premolar to simulate threeunites bridge. j bagh college dentistry vol. 29(1), march 2017 a study to compare restorative dentistry 28 impression procedure: sixteen impressions were taken to the model with polyvinylesiloxan impression material ( zhermack, italy) to produce 16 stone model for the fabrication of (8) three-unites bridges , (8) maxillary first premolar zirconium single crowns. putty–wash technique was used to take impression, after the impression procedure was completed; impressions were poured by using type iv dental stone (zhermack. italy). after that all stone models were inspected under the light to exclude any defects such as air bubbles, then labeled and fixed on the plaster base, ready for scanning to produce the bridges and crowns as in (figure.2). figure 2: stone model on the plaster base ready to the scanning. sample grouping: the samples were divided into two groups (group no. 8): group a: eight cad-cam single zirconium crowns for maxillary first premolar. group b: eight cad-cam three – unit bridges zirconium from maxillary first premolar to the maxillary first molar. scanning and construction of the crowns and bridges: all of abutments were scanned by the amanngerbach scanner device and designed by the software of the same system, the software setting was the same for all the abutments in crowns and bridges to get standardization. after the crowns and bridges design were completed, the order was given to the milling machine to mill the amanngerbach presintered zirconium block to produce the crowns and bridges then the crowns and bridges sintered by the amanngerbach furnace. cementation, blocking and sectioning: crowns and bridges seated on their respective stone models (figure.3), overextended and under extended crown and bridges were excluded. glass ionmer cement was used for cementation, the cement was painted on the internal surface of the crowns and bridges, the crowns and bridges were initially seated on the stone model by fingure pressure then 5 kg weight was applied over (crowns and bridges – stone model unit) for 10 minutes to ensure complete seating, piece of wood was used for leveling. after the cementation procedure completed, crowns and bridges were blocked with clear acrylic resin to support the crown and bridges-stone unite during the sectioning. figure 3: crowns and bridges seated on their respective stone model. crowns and bridges were sectioned longitudinally into four piece at midpoint buccolingaully and mesiodistaly according to pencil line was drawn at the midpoint of abutment before sectioning (1), by sectioning machine with diamond disc (0.8 mm) with water coolant as in( figure .4) . figure 4: sectioning machine with water coolant. microscopical examination: after sectioning of the crowns and abutment of bridges, five point (marginal opening, chamfer area, midaxial, cusp tip and midocclusal) selected to measure the marginal and internal fitness. the measurements j bagh college dentistry vol. 29(1), march 2017 a study to compare restorative dentistry 29 were achieved by stereomicroscope provided with digital camera connected with computer at 120x magnification. measurements were done by placing the sample on the microscope stage, which was adjusted until the image of the marginal and internal fitness was displayed clearly on the computer monitor, and the digital images of specimens were captured. the image was treated with program (image j), which was used to measure the marginal and internal fitness between the stone die and zirconium core as in( figure.5) .the records were done by two experienced persons and all records repeated two times to reduce the possibility of error. (6) figure 5: digital image show the border of zirconium core, glass ionmer cement and stone die under the microscope. statistical analysis: the spss software package was used to perform the statistical analysis. one-way anova (analysis of variance) test was carried out to see if there was any significant difference among the variables of groups. independent t-test was carried out to detect the significant differences between the crowns and bridges in gap values. results: the measurements of marginal and internal fitness were (320) totally from two groups, eight upper first premolar crowns and eight of upper first premolar within three-unit bridges that include 20 measurements of each crown and abutments of bridges. the results showed that the maximum gap was found in the occlusal area while the minimum in the axial area, also there were differences between the premolar single crown and premolar crown within the bridge as in bar -chart (figure .6) and (table.1). figure 6: barchart showing the differences between the premolar single crowns and premolar within the bridge in marginal and internal fitness. discussion: marginal and internal fitness are critical for the longevity of single or multiple-unit fixed-partialdentures and the prognosis of the restored tooth. the solubility of luting agent restorative material leading to microleakage, plaque accumulation, caries and subsequent failure of the restoration (7). in cad/cam or copy-milling systems, the marginal opening has been reported to range between 60 μm and 300 μm ,while a clinically acceptable value of marginal discrepancies is advised to be less than 120 μm(8). for marginal and internal gaps of zirconia restorations, it was found that the fit of zirconia restoration is influenced by heterogeneity in terms of experimental methodology, milling system, manufacturers, sintering states of the zirconia, sample size and span length (9). in this in vitro study there were differences in the fitness among the five positions within the same tooth. the maximum gap was found in the occlusal area while the minimum in the axial area, this may be because of the more complex shape of the occlusal surface. in addition, cad/cam software may not as precise as it should be. therefore, it has to be considered that a tendency for the greater gaps than the expected value could be found (9). there were differences in marginal and internal fitness between the single crown and the crowns within three – unite bridge zirconium framework, so the null hypothesis which stated that manufacturer's recommended parameters for cad/cam zirconia system were precise for all surface and in crowns j bagh college dentistry vol. 29(1), march 2017 a study to compare restorative dentistry 30 and bridges not acceptable, and difference between the bridge and single crown due to larger dimension of bridge framework than those of single crown substructure, this was in agreement with this study (9,10) . a study in 2001 reported that long span bridge had large values of marginal discrepancy but the values not significantly difference (11), this disagree with this study. also, in this in vitro study, the small gap in the axial and marginal opening and large gap in the occlusal, cusp area and chamfer area, one possible explanation to that difference might be the entrapment of cement in the occlusal, chamfer and cusp area during cementation due to abscence of vent like that in cast restoration while in the axial and marginal opening there were a chance to exit out during cementation. in this in vitro study used the pre-sintered zirconium block to fabricate the crowns and bridges, about 20-30% shrinkage occur in the zirconium during the sintering. some of studies reported that the shrinkage differ in different position within the same abutment ,there were study in 2007 studied the effect of shrinkage during sintering on the zirconium restoration and found the shrinkage in the tooth axis(margin and axial) smaller than the horizontal axis (cusp and occlusal area) ,also when the distance between the abutments increase , the marginal discrepancy will increase and the shrinkage of pontic may affect the marginal and internal fitness of the bridge(12) , this agree with this study. in this in vitro study, the differences between the premolar as single crown and premolar within the bridge were in marginal opening and there were differences in cusp tip lingually and distally, the possible explanation for this, it might due to bridge configuration and shrinkage of pontic led to more gap at lingual and distal side and less gap in buccal and mesial side. a study in 2007 evaluated the fitness of zirconium restoration clinically, they stated the shrinkage during sintering increase the chance of developing gap between the abutment and restoration especially in the bridge than the single crown because of more complex geometry of bridge (13). this agree with this study. conclusion: within the limitations of this in vitro study, the following conclusions can be derived: 1. the mean marginal gaps of zirconium in both crowns and bridges within the acceptable range 120µm. 2. the marginal and internal gaps in the bridge higher than those in the crowns. 3. the areas of sloped surfaces such as chamfer area, occlusal area and cusp tip had high gap values in compare with area of flat surface such as axial wall. 4. when the surface area of abutment increased, the marginal and internal gaps would increase. referances: 1. beuer f, aggstaller h, edelhoff d, gernet w, sorensen j. marginal and internal fits of fixed dental prostheses zirconia retainers. dent mater 2009; 25 : 94-102. 2.komine f, gerds t, witkowski s, strub jr. influence of framework configuration on the marginal adaptation of zirconium dioxide ceramic anterior four-unit frameworks. acta odontol scand 2005; 63: 361-6. 3. karatasli o, kursoglu p, çapa n, kazazoglu e. comparison of the marginal fit of different coping materials and designs produced by computer aided manufacturing systems. dent mater j 2011; 30(1): 97–102. 4. subasi g, ozturk n, inan o, bozogullari n. evaluation of marginal fit of two all-ceramic copings with two finish lines. eur j dent 2012; 6: 163-8. 5. otto t, de nisco s. computer aided direct ceramic restorations: a 10years prospective study of cerec cad/cam inlays and onlays. int j prosthodont 2002; 15:122-8. 6. groten m, axmann d, probster l, and weber h. determination of the minimum number of marginal gap measurements required for practical in vitro testing. j prosthet dent 2000; 83(1):40-9. 7. comlekoglu m, dundar m, özcan m, gungor m, gokce b, artunc c. influence of cervical finish line type on the marginal adaptation of zirconia ceramic crowns. oper dent 2009; 34: 586-92. 8.nakamura t, dei n, kojima t & wakabayashi k. marginal and internal fit of cerec 3 cad/cam allceramic crowns int j of prosthodont 2003; 16(3): 244-8. 9. anunmanac, masnisacharoenchitt, and chanavut asvanund. gap comparison between single crown and three-unit bridge zirconia substructures. cvj adv prosthodont. aug 2014; 6(4): 253–258. 10. reich s, kappe k, teschner h, schmitt j. clinical fit of four unit zirconia posterior fixed dental prostheses. eur j oral sci.2008;116:579–584. 11.tinschert j, natt g, mautsch w, spiekermann h, anusavic kj. marginal fit of alumina-and zirconia-based fixed partial dentures produced by a cad ⁄cam system. oper dent. 2001;26:367–374. 12. kunii j , hotta y , tamaki y , ozawa a , kobayashi y , fujishima a , miyazaki t , fujiwara t . effect of sintering on the marginal and internal fit of cad-cam fabricated j bagh college dentistry vol. 29(1), march 2017 a study to compare restorative dentistry 31 zirconia framework. dental material journal . 26(6):820826, 2007. 13. tsumita m, yuji kokubo, chikahiro ohkubo,yuki nagyma ,sato sukari and shungi fakushima. clinical evalution of marginal and internal gap of zirconia base three unite cad-cam fixed partial denture. prosthdont res.pract.2007; 6: 114-11 table (1): comparing the marginal and internal fitness between premolar single crown and premolar within the bridge. sides positions descriptive statistics comparison (d.f. = 14) premolar crown premolar bridge mean s.d. mean s.d. t-test p-value buccal marginal opening 44.825 6.848 50.663 5.756 -1.846 0.086 (ns) chamfer area 79.950 5.219 82.338 10.661 -0.569 0.578 (ns) axial wall 41.250 5.997 41.775 6.220 -0.172 0.866 (ns) cusp tip 79.650 9.500 90.538 11.190 -2.098 0.055 (ns) occlusal area 97.763 6.840 107.650 10.466 -2.237 0.042 (s) lingual marginal opening 40.388 6.665 49.700 6.360 -2.859 0.013 (s) chamfer area 71.575 8.324 80.438 8.710 -2.081 0.056 (ns) axial wall 37.713 4.640 40.638 7.143 -0.971 0.348 (ns) cusp tip 74.413 7.504 94.363 15.120 -3.343 0.005 (hs') occlusal area 98.750 6.250 106.625 8.809 -2.062 0.058 (ns) mesial marginal opening 44.713 7.171 52.588 5.977 -2.386 0.032 (s) chamfer area 68.438 6.682 72.338 9.896 -0.924 0.371 (ns) axial wall 43.263 5.562 42.525 7.618 0.221 0.828 (ns) cusp tip 74.763 9.218 85.125 11.237 -2.017 0.063 (ns) occlusal area 95.825 7.536 102.575 13.222 -1.254 0.230 (ns) distal marginal opening 43.838 5.984 50.025 5.332 -2.184 0.047 (s) chamfer area 72.650 7.545 74.763 7.303 -0.569 0.578 (ns) axial wall 42.375 6.513 40.213 5.120 0.738 0.473 (ns) cusp tip 71.600 9.367 87.150 12.157 -2.866 0.012 (s) occlusal area 96.125 7.209 103.300 9.769 -1.671 0.117 (ns) الخالصة: \ركونيا والمصممة بمساعدة الحاسوب لغرض من هذه الدراسة مقارنة الفجوة في حافات األسنان والتركيب الداخلي بين التيجان والجسور المتكونة من ثالث أسنان المصنعة من الزا والمنحوتة باستخدام الحاسوب . لجسور وذلك االتيجان للضواحك العليا وثمان أسنان للطواحن العليا وثمان جسور تتكون من ثالثة أسنان وتكون الضواحك والطواحن العليا من ضمن أسنان تم تحضير ثمان عينات من ام وتم تصنيعها حسب مواصفات المصنع وباستخدباستخدام قالب جاهز مصنع من قبل شركة ايفوكالر وحسب مواصفاتها العالمية . تتكون مادة كل من الجسور والتيجان من الزركونيا طة ألة سمنت , بعد ذلك تم تقطيع العينات بواسوتصميم الحاسوب والماكنة النحاتة . بعد إتمام عملية نحت التيجان والجسور تم وضعها على قوالبها الحجرية ولصقها بمادة كالس ايونمر ة الحاسبة لقياس الفجوة في الحافات والتركيب الداخلي ومقارنة النتائج بين التيجان والجسور باستخدام البرنامج اإلحصائي القطع إلى اربع قطع لغرض فحصها تحت المجهر وبواسط .test-(independent t( وبرنامج )(anovaأحادي االتجاه ث ان هنالك فرق في الفجوات في الحافات والتركيب الداخلي بين التيجان والجسور حيأظهرت النتائج بان هنالك فرق في الفجوات بالتركيب الداخلي في نفس السن بأماكن مختلفة , وأيضا المنحوتة -ممة و المصنعة بواسطة الحاسوبالفجوات في الحافات والتركيب الداخلي للجسور تكون اكبر من تلك في التيجان , وان الفجوات في كل من الحافات في التيجان والجسور المص ت المقبولة سريريا.هي من ضمن الفجوا noor f.doc j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry168 assessment of the esthetic smile in a sample of iraqi population noor f. k. al-khawaja, b.d.s., m.sc. (1) abstract background: the aim of the present study is to evaluate the esthetic smile in sample of iraqi adults and to assess the gender differences. materials and methods: 100 persons (50malesand 50 females had class i normal dental and skeletal selected for this study.clinical examination and digital photograph with posed smile were performed for each individual. six linear soft tissue parameters in each photograph using autocad program 2011. five visual and four quantitative evaluations of the smile were studied for eachsubject. the smile arch and index, buccal corridor spaces (bcss) were studied.descriptive statistics of the measurements were calculated. independent student’s ttestswere used to evaluate the gender differences. statistics: descriptive statistics and standard error of each measurement was calculated. independent sample t-tests were used to compare the measurements of male and female subjects. chi square used for visual measurements. results and conclusion: the average smile, parallelism of the upper incisal curve with the inner curvature of the lower lip, 1:1 ratio of the widths of nose and upper cuspid were higher in females than males while in smile curve arch line without touching the lower lip the opposed and 2nd premolars are the most common display in both groups.females showed higher than five smile index indicate a constant well balanced smile in females than in males, females showed a well-balanced expression with posed smile, a medium buccal corridor in both females and males. key words: smile, esthetics. (j bagh coll dentistry 2013; 25(3):168-175). introduction facial attractiveness has been suggested to have an influence on personality development and social interaction (1-3) .the smile plays an important role in facial expression. facial attractiveness and smile aesthetics are strongly related to each other. individuals mainly focus on another person’s eyes and mouth during interpersonal interaction (4), and the smile ranks second only to the eyes as the most important feature in facial attractiveness(5). therefore, an attractive, well-balanced smile is a highly regarded treatment objective, along with creating a functional occlusion. saver (6) emphasized the importance of the soft tissue profile, including the smile, to evaluate the diagnosis, treatmentplanning and the mechanics in orthodontic cases. althoughan esthetic smile has been studied in dentistry (7), recently,the detailed evaluation of how soft tissue profiles are related tothe smile arch, smile index and buccal corridor have not onlybeen studied in orthodontic treatment(8-10). more recently, there are several researchs to support that the minimal buccalcorridor constitutes a preferred esthetic smile by orthodontist(11-15). however, there is a difference in evaluating an estheticsmile by dentists, orthodontists and laypersons (16-18). an attractive smile depends not only on components such as tooth size, shape, colour, and position but also on the amount of visible gingivae and the framing of the lips (19). (1) assistant lecturer. department of orthodontics, college of dentistry, university of baghdad a ‘gummy’ smile results from a combination of factors such as vertical maxillary excess, increased overjet, increased overbite, a short upper lip, and a short incisor crown length (20). however, peck et al. (21,22) reported that upper lip length and incisor crown length did not appear to be associated factors. what is beautiful or attractive to dental professionals, based on their experience and training, may not agree with the perceptions of other individuals (24). shaw et al. (25) and prahlandersen (26) reported that dental professionals are conditioned to take an overly critical view of any deviation from normal occlusion. although many orthodontists and surgeons have the opinion that a gummy smile is unattractive (21,22), the perception of the same for dental students as young adults may differ. tjan and miller (7) divided the smile line into three types: a high smile line, revealing the complete maxillary incisors and a continuous band of the gingiva; an average smile line, revealing 75–100 per cent of the maxillary incisors; and a low smile line, revealing less than 75 per cent of the maxillary incisors. excessive gingival display can severely detract from an attractive smile. although, in western society, it has been suggested that no more than 2 mm of the maxillary gingiva should be visible when a person smiles (23), there has been no scientific evidence to support this view in the asian community, particularly iniraqipopulation. the aim of this study was to evaluate an esthetic smile in sample of iraqi adults and to evaluate the gender differences. j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry169 materials and methods sample the sample of the study composed of 100 iraqi adult subjects with an age ranged between 18-30 years. they were selected from colleges of medicine and dentistryuniversity of baghdad.the sample was classified into two groups, group 1 50 female and group 2 50 male. criteria of the sample selection the entire sample was iraqi arab subjects with an age ranged between 18 and 30 years old with no previous orthodontic, orthopedic, or facial surgical treatments. all had full permanent teeth regardless the third molars with no or minor spacing or crowding and class i skeletal, molars, canines and incisors classification (27). methods 1. history and clinical examination each subject was asked to seat comfortably on the dental chair and asked information about the name, age, origin, medical history, the history of facial trauma and orthodontic treatment. then they were asked to look forward horizontally (frankfort plane parallel to the floor) for clinical examination (extra-orally and intra-orally) to check their fulfillment of the required sample selection. 2. standardization of the photographs a. the camera (sony cybershot h 50, 9.1 mega pixels, 15 x optical zoom, sony corporation, nagoya, japan) was fixed in position with a tripod. b. the distance between the camera and the subject was measured from the tripod’s column to the ear rods (fig.1). c.the blue background, 0.95 m wide and 1.10 m high, behind the subject was made of a piece of cloth (28). d. two flash lights, with two umbrellas to diffuse and soften the light, were used. e. a ruler was placed on the adjustable plastic nasal stopper part of the cephalostat, to be used later for magnification correction (14,29). 3.photographical technique the subject was seated on a stool and his head was fixed with the aid of the cephalostat. the frankfort horizontal plane was parallel to the floor (30,31).the digital camerawas set on manual exposure shooting. the subject was asked to close in centric occlusion, smile and say word “cheese” to obtain an ideal lip-tooth presentation at smile (32) figure 1 4. measuring techniques a. the photographs were imported to the autocad program. b. magnification correction was done. c. after that, identification of landmarks was made, and measurements were determined. soft tissue landmarks, figure 2: 1. chilion (ch): a point located at each angle of mouth and selected to be on same level with stomion(33,34) 2. stomionsuperius (stos): the lower most point on the vermilion border of the upper lip (30). 3. stomioninferius (stoi): the upper most point on the vermilion border of the lower lip (30). figure 2 lines, figure 3 and 4: a. interlabial distance at the midline between stos point and stoi point. b. outer commissurewidth between right and left chilion. c. distance between the most inferior point of theupper lip (stos) and the incisal edge of upper incisors. d. distance perpendicular to the upper incisal edge from the outercommissure width. e. upper cuspid width at most buccal points of upper canines f. inner commissure widthit is the distance between right and left inner commissural linewhich passes through the mucosa overlying the buccinators muscle where it inserts with the orbicularis oris muscle fibers at the modiolus. j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry170 g. and h, left and rightside bcs. i, space between interlabial gap (area measurement). figure 3 figure 4 measurements 1smile index: it represents the smile zone, obtained by dividing the outer intercommissural width by the inter-labial gap (b/a) (35). 2gingival exposure: obtained by dividing the distance between stomionsuperius and the incisal edge of upper incisors by the outer inter-commissural width (c/b) or distance perpendicular to the upper incisal edge from the outercommissure width by the outer intercommissural width (d/b) 3buccal corridor width (bcw): the distance between the outer and inner commissural widths.(29,35) 4buccal corridor linear ratio (bclr):calculated by dividing inter canine distance on outer commissural widths(51,53). 5buccal corridor space (bcs): as the distance between the lateral junction of the upper and lower lips and the distal points of the canines during smiling.(15).or as a space between the inner commissure and thelateral surface of the upper posterior teeth (g+h/i %) (53). five visual and three quantitative evaluations of each posed smile were made. i. the five visual evaluations of a smile were 1.tjan’s smile classification,tjan(9) made an indicator of esthetic evaluation in oral morphology. according to him, a smile was classified intothree different categories: (1) low smile (upper incisors appearless than 75%); (2) average smile (75–100% of incisor appearanceand gingiva); (3) high smile (100% teeth appearance andfull gingival, called a ‘‘gummy smile’’). 2.position of the upper incisal curve relative to touching the lower lip either touching or not touching or slightly covered by lower lip. 3.parallelism of the upper incisal curve with the lower lip, parallel or straight or reversed. 4.the number of teeth displayed in a smile. 5.the relationship between the widths of the nose and upper cuspid. ii. the three quantitative evaluations of a smile were: 1. smile index = b/a 2.gingival exposure (c/b, or d/b) in fig. 3 3.buccal corridor; width, linear ration and space(g + h/i%), in figs. 4. statistical analysis descriptive statistics and standard error of each measurement was calculated. independent sample t-tests were used to compare the measurements of male and female subjects. chi square used for visual measurements. results i. visual evaluations of a smile (table 1); 1. tjan’s smile classification. female group of 54 samples, 14.2% had an average smile, 13.3% had a low smile and 20.4% a high smile. while for male group of 59 samples, the average smile was 9.7%, 22.1% had a low smile and 20.4% a high smile, with no significant differences between males and females. 2. position of the upper incisal curve.in female group out of 54 samples, 34 (30.1%) showed an incisal curve of the upper anterior teeth without touching the lower lip. in 11 (9.7%) subjects these teeth touched the lower lip and in 9 (8%) they were slightly covered by the lower lip. while in male group out of 59 samples, 47 (41.6%) showed an incisal curve of the upper anterior teeth without touching the lower lip. in 6 (5.3%) subjects these teeth touched the lower lip and in 6 (5.3%) they were slightly covered by the lower lip, with no significant differences in chi squire test. 3. parallelism of the upper incisal curve. in female group out of 54 samples, 38 (33.6%) showed parallelism of the upper incisal curve with the inner curvature of the lower lip. 10 (8.8%) subjects had a straightrather than a curved or reversed line and 6 (5.3%) in reversed line. while for male group out of 59 samples 31 (27.4%) showed parallelism of the upper incisal curve with the inner curvature of the lower lip. 18 (15.9%) subjects had a straight rather than a curved or reversed line and 10 (8.8%) in reversed line. j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry171 4. number of teeth displayed. the range of teeth displayed in a present posed smile is 9 ± 0.15 in female and 10 ± 0.21 in male samples, with no significant differences. 5. width of the nose and upper cuspid. 30.1% of female group and 10.6% of male group were close to a 1:1 ratio between the widths of the nose and upper cuspid, with significant differences. ii. quantitative evaluations of smiles (table 2). 1. smile index (b/a). the mean was 5.77 in female group and 5.93in male group. there was no significant difference between both groups at p > 0.05% (fig. 3). 2. upper gingival exposure (c/b or d/b). the calculation of g/b, i.e. the mean of the exposure was 0.15 in female group and 0.13 in male group, which was significantly different atp > 0.01%. for the calculation of f/b, the mean was 0.15for female group and 0.14 for male group, which was no significantly different (p> 0.05%) (fig. 3). 3. buccal corridor width (bcw), linear ratio (bclr) and space (bcs). the bcw was calculated by the distances between owc and icw, the study showed a higher mean value in males 5.24 than in females 4.93 with no significant differences between right and left and in genders while bclr (e/b%) was calculated by the ratio of the maxillary cuspiddistance and the outer commissure distance. the mean was 60.15% for female and 58.68% for male with no significant differences. bcs volume (space) analysis (g + h/i%) of bc showed amean of 15.83% in female group and 16.28% in male group. there was no significant difference between groups. discussion a well-balanced smile, which is based on the balance among teeth, lips, dentition and the jaw, is one of the important factors to get a quality orthodontic treatment (6,8,9) .according to psychological, anatomical and anthropological points of view, smiles are classified into either commissure, cuspid or complex smiles, (35-37) based on smile studies in which evidenced based dentistry could be standardized. smiles are classified in two groups. one is an unposed smile, which is an active smile induced unconsciously in response to a happy emotion. the other is a posed smile which is a passive smile induced in response to a conscious emotion. the difference between both smiles is that the active lip posture in a posed smile is reproducible (38-40). the reliability of a posed smile’s reproducibility is quite high (93–98%) (38). tjan(9) made an indicator of esthetic evaluation in oral morphology. according to him, a smile was classified into three different categories: (1) low smile (upper incisors appear less than 75%); (2) average smile (75–100% of incisor appearance and gingiva); (3) high smile (100% teeth appearance and full gingival, called a ‘‘gummy smile’’). he found 68.9% of subjects showed an average smile, 20.5% a low smile and 10.6% a high smile. the average smile is ideal in caucasian (8,22,32,36-38). in the present study, 14% of female group showed an average smile, 13% a low smile and 23% a high smile. male group showed 10% an average smile, 22% a low smile and 23% a high smile, with no significant differences between male and female. peck et al (21) and tjan and miller (7) found that low smile lines are a predominantly male characteristic (2.5 to one male to female) and a high smile line is predominantly female (two to one female to male). while in present study (1.6 to one male to female) in case of low smile and higher in female (1.4 to one female to male) for average smile and the same in high smile in male and female which is differ from that found in peck, and this is may be due to difference in ethnics groups. when looking at the smile arc (parallel, flat, andreverse), we found that approximately (61%) of thetotal sample had parallel smile arc. this disagrees with maulik and nanda(41) who both foundthe flat smile arc to be most frequent in theirsubjects, and agree with thefindings of tjan et al(7) and dong et al,(42) who both foundthe parallel smile arc to be most frequent in theirsubjects. this difference could be due to the smile arcmeasurement process, which can be considered subjective.great care was taken to keep the measurement anddata-gathering processes as standardized and objectiveas possible. for example, to obtain natural head position, the subjects were asked to look straight forward asif they were looking at their eyes in a mirror(43).another objective was to compare the smile arc between the sexes. we found a statistically no significant difference between them with higher parallel smile in female than male and lower for flat and reversed smile. this agrees with maulik and nanda (41). tjan(40) also studied the relationship between touching behavior of upper incisors and the lower lip, which effects a smile’s balance (18,38). although he reported 57.8% of subjects (female) showed lipincisor touching, while in murakami etal., (45) orthodontic treated patients and magazine models showed 63 and 60% non-touching to the lower lip which is quite different to his finding, j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry172 respectively, which was similar to other data on japanese females (38,44). in present study 17% touching and 72% not touching and 13% slightly covered by lower lip with higher frequencies in female than male in both touching and slightly covered. with no significant differences.one of the golden ratio’s balanced facial profile is the 1:1 ratio of the widths of the nose and upper cuspids, as determined by ricketts (33). however, he described that this relationship is not mathematically proved. in the present study 40.7% of total sample showed 1:1 ratio with higher present in female 30.1% than male 10.6% this is differ from finding of murakami etal., (45) which showed 80 and 90% of orthodontic treated patients and magazine models were close to a 1:1 ratio. those high percentages in both groups could be explained by a wider nose matched with a wider arch width (46,47)than in caucasians, as is characteristic of japanese anterior facial profiles.in tjan’s american caucasian study (9), the highest percentage display of teeth was of the 1st bicuspid (eight teeth), which is similar to murakami etal., (45)in japanese femalesshowed 10% of 60 subjects a cuspid to cuspid and 90% a display of bicuspids in orthodontic treated patients and magazine models, respectively. there was no display of 1st molars in both orthodontics groups. other studies in japanese subjects were similar to murakami etal.(38,44,45). while in present study all female showed highest percentage display of teeth was of 2nd bicuspid (nine and ten teeth) about 26% than 14% was of 1st bicuspid (seven and eight teeth) and lesser percentage in 1st molar 8% (eleven and twelve teeth) and in male small percentage 1.7% showed from cuspid to cuspid and 17% of 1st bicuspid, 19% of 2nd bicuspid and 25% of 1st molar. i.e. 45% of total sample displayed from 2nd bicuspid to 2nd bicuspid. maulik and nanda(41) results for the most posterior maxillary tooth visible showed that 51% of the sample displayed the maxillary second premolars; dong et al(42)found similar results, with 57% of their sample showing maxillary second premolars. a surprising result, which did not agree with either dong et al(42)or tjan et al,(7) was that 25% of our sample showed the maxillary first molars on smiling. tjan et al(7) found that only 4% of their subjects showed the maxillary first molars on smiling. this is a notable difference, and one of the largest differences of all variables between our study and the others. an argument could be made that this difference was due to lighting. neither tjan et al(7) nor dong et al(42)described in detail how they gathered their data or the lighting situation when they photographed the smiles.assessing the quantitative evaluation of a smile, (1) the smile index was 5.77 and 5.93 in female and male groups with no significant difference between groups. in female group, 43 out of the 54 subjects showed higher than 5.0 index values. while in male group lesser than that about 37 out of the 59 subjects only showed higher than 5.0 index values this indicate a constant, well balanced smile in female more than male, i.e. female well trained posed smile or cared more about their smile than male. (2) the amount of upper gingival exposure was studied by applying two different measurements (c/b and d/b). the two different measurements in female and male were 0.15, 0.15 and 0.13, 0.14, respectively. there was a significant difference between groups (p > 0.01), which indicated less movement of lips and the corner of the mouth in male. this significant difference between both measurements in male subjects indicates that a smile presents a wider inner commissure width with a pushed up corner of lips and more movement of lips than that of female. female group showed a well-balanced expression with a posed smile more than male subjects(3) bcw, according to krishnan et al. (29) and ackerman and ackerman(35).who measured the right and left buccal corridor widths as the distances between owc and icw, the study showed a higher mean value in males 5.24 than in females 4.93 with no significant differences between right and left and in genders, these results similar but slightly smaller than that of krishnan et al. (29) and ritter et al.(14). the difference may be related to differences in ethnic groups or in sample selection.in the present study, bcw was measured also by the hulsey method (51) female group showed a mean of 60.15% and 58.68% in male group. there was a no significant difference between groups. (4) bcs was studied. bcs is quite important to evaluate an esthetic smile (8). bcs had been studied half a century ago in prothodontists(45). hulsey (51)developed his own measurement of bcs based on the upper cuspid width.ackerman and ackerman (35)found that the corner of lips with a smile showed a difference by the way light was projected, and he classified bcss for their inner and outer commissures. the inner commissure is an area of the inner buccal membrane of oral muscles fibers. applying this method, moore et al.(13)studied the volume of bcs to find a good balance in a face. he classified five different types of inner and outer commissures by changing the photo’s original image and got the opinion of a third party. five classifications were narrow (28%), mediumnarrow (22%), medium (15%), medium-broad (10%) and broad (2%).in the present study, bcs j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry173 values of females and males were 15.83% and 16.28%, respectively. this data was similar to ‘‘medium’’ of moore’s classifications (13). the study found the range of bcs to be 8-26%. with no significant differences between females and males this differ from findings of maulik and nanda(41) , who showed 12.3% in males and 10% in females with significant differences between groups. thus, the differences between two measurements in both groups depended only on the method of measurements, sample selection and ethnic groups. the conclusions drawn from this study were: 1. the high smile, smile curve arch line without touching the lower lip, parallelism of the upper incisal curve with the inner curvature of the lower lip, 10% display of the 1st molar, 1:1 ratio of the widths of nose and upper cuspid, common features of females group while the low smile, smile curve arch line without touching the lower lip, parallelism of the upper incisal curve with the inner curvature of the lower lip, 8% display of the 1st molar, no 1:1 ratio of the widths of nose and upper cuspid are common features of males group. 2. the average smile, parallelism of the upper incisal curve with the inner curvature of the lower lip, 1:1 ratio of the widths of nose and upper cuspid were higher in females than males while in smile curve arch line without touching the lower lip the opposed and 2nd premolars are the most common display in both groups. 3. females showed higher than 5 smile index indicate a constant well balanced smile in females than in males 4. females showed a well-balanced expression with posed smile 5. a medium buccal corridor in both females and males. references 1. adams gr. physical attractiveness research: toward a developmental psychology of beauty. human development 1977; 20: 217–39 2. feingold a. good-looking people are not what we think. psychological bulletin 1992; 111: 304–41 3. thompson l, malmberg j, goodell n, boring r. the distribution of attention across a talker’s face. discourse processes 2004; 38: 145–68 4. miller ag. role of physical attractiveness in impression formation. psychological science 1970; 19: 241–43 5. goldstein re. study of need for esthetics in dentistry. j prosthet dent 1969; 21: 589–98 6. saver dm. the importance of incisor positioning in the esthetic smile: the smile arc. am j orthod dentofac orthop 2001; 120: 98–111. 7. tjan ah, miller gd, the jg. some esthetic factors in a smile.jprosthet dent 1984; 51: 24–8. 8. sarver dm, ackerman mb. dynamic smile visualization and quantification. part 1.evolution of the concept and dynamic records for smile capture. am j orthod dentofaci orthop 2003; 124: 4–12. 9. sarver dm, ackerman mb. dynamic smile visualization and quantification. part 2. smile analysis and treatment strategies. am j orthod dentofac orthop 2003; 124:116–27. 10. ackerman mb, brensinger c, landis jr. an evaluation of dynamic lip–tooth characteristics during speech and smile in adolescent. angle orthod 2004; 74: 43-50. 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(ivsl). 25. shaw wc, lewis hg, robertson nr. perception of malocclusion. br dent j 1975;138: 211–6 26. prahl-andersen b. the need for orthodontic treatment. angle orthod 1978; 48:1–9 27. foster td. a textbook of orthodontics. 3rd ed. oxford: blackwell scientific publications; 1990. 28. meneghini f. clinical facial analysis. 1st ed. springerverlag berlin heidelberg; 2005. p.16-17. j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry174 29. krishnan v, daniel st, lazar d, asok a. characterization of posed smile by using visual analog scale, smile arc, buccal corridor measures, and modified smile index. am j orthod dentofac orthop 2008; 133(4): 515-23. (ivsl). 30. jacobson a. radiographic cephalometry from basics to videoimaging. 1st ed. chicago: quintessence publishing co; 1995. p.43, 240. 31. bishara se. a textbook of orthodontic. 1st ed. philadelphia: w.b. saunders company; 2001. p. 104, 331, 354, 566. 32. zachrisson bu. esthetic factors involved in anterior tooth display and the smile: vertical dimension. j clin orthod 1998; 32(7): 432-45. 33. ricketts rm. the biologic significance of the divine proportion and fibonacci series. am j orthod 1982; 81(5): 351-70. 34. farkas lg, kolar jc, munro ir. craniofacial disproportions in apert syndrome, an anthropometric study. cleft palate j 1986; 22(4): 253-64. 35. ackerman mb, ackerman jl. smile analysis and design in the digital era. j clin orthod 2002; 36(4): 221-36. 36. phillips ed. the classification of smile patterns. j can dent assoc 1999; 65: 252–4. 37. phillips e. the anatomy of a smile. oral health 1996; 86: 7–13. 38. mikami i. an evaluation of the functional lip posture. shigaku 1990; 78: 339–76. 39. rigsbee oh, sperry tp, begole ea. the influence of facial animation on smile characteristics. int j adult orthod orthognath surg 1988; 3: 233–9. 40. ackerman mb, ackerman jl, brensinger cm, landis jr. a morphometric analysis of the posed smile. clin orthod res1998;1: 2–11 41. maulik c, nanda r. dynamic smile analysis in young adults. am j orthod dentofac orthop 2007; 132(3): 307-15. 42. dong jk, jin th, cho hw, oh sc. the esthetics of the smile: a review of some recent studies. int j prothodont 1999; 12: 9– 19 43. moorees cfa. natural head position: a basic consideration in the interpretation of cephalometric radiographs. am j phys anthropol 1958; 16: 213-34. 44. kimura h, konagai h, haneda k, hayashi t, shibata k, nishijima t, et al. study on teeth and expression relationship between teeth and lip in a smile. shigaku 1985; 72: 1251–5. 45. murakami y, deguchi sr. t,kageyama t, miyazawad h, foong k. assessment of the esthetic smile in young japanese women. orthodontic waves 2008; 67: 104– 112 46. nojima k, mclaughlin rp, issiki y, sinclair pm. a comparative study of caucasian and japanese mandibular clinical arch forms. angle orthod 2001; 71: 195–200. 47. kook ya, nojima k, moon hb, mclaughlin rp, sinclair pm. comparison of arch forms between korean and north american white populations. am j orthod dentofac orthop 2004; 126:680–6. 48. hattab fn, al-khateeb s, sultan i. mesiodistal crown diameters of permanent teeth in jordanians. arch oral biol 1996; 41: 641–5. 49. lavelle cl. maxillary and mandibular tooth size in different racial groups and in different occlusal categories. am j orthod 1972; 61: 29–37. 50. shibamoto h, hata y, yano k, matsuka k, ito o. a geometric study of the facial features of japanese people. j jpn plast reconstr surg 1992; 12: 429–42 [in japanese]. 51. hulsey cm. an esthetic evaluation of lip–teeth relationship present in the smile. am j orthod 1970; 57: 132–44. 52. frush jp, fisher rd. the dynesthetic interpretation of the dentogenic concept. j prosthet dent 1958; 8: 558– 81 53. yang h, nahmb ds, baekc sh. which hard and soft tissue factors relate with the amount of buccal corridor space during smiling? angle orthod 2008; 78(1): 5-11. table 1. visual evaluation of a smile female male x2 p value number % number % 1 tjan’s smile classification 3.211 0.20 low smile 15 13.3 25 22.1 average smile 16 14.2 11 9.7 high smile 23 20.4 23 20.4 2 incisal curve relative to touching the lower lip 3.943 0.139 touching 11 9.7 6 5.3 not touching 34 30.1 47 41.6 slightly covered 9 8.0 6 5.3 3 incisal curvature in relationship to lower lip 3.782 0.151 parallel 38 33.6 31 27.4 straight 10 8.8 18 15.9 reversed 6 5.3 10 8.8 4 nasal width in relation of the maxillary cuspid width 19.493© 0*** same 34 30.1 12 10.6 not same 20 17.7 47 41.6 5 the average of teeth displayed in a smile (a) 9 ± 0.15 10 ± 0.21 0.252 (b) (a) means , standard deviation., (b)t test , (c) continuity correction, computed only for a 2x2 table j bagh college dentistry vol. 25(3), september 2013 assessment of the pedodontics, orthodontics and preventive dentistry175 table 2. quantitative evaluation of a smile female male t-test mean s.d. mean s.d. sig. 1 smile index 5.77 1.94 5.93 1.90 0.658* 2 upper gingival exposure g/b 0.15 0.05 0.13 0.04 0.028** upper gingival exposure f/b 0.15 0.04 0.14 0.04 0.09* 3 buccal corridor width (bcw) rt bcw 5.06 1.23 5.51 1.56 0.092* lt bcw 4.81 1.41 4.96 1.31 0.54* 4 buccal corridor linear ratio (bclr) 60.15 4.07 58.68 5.78 0.12* 5 volume analysis of bcs (bcar) right 7.85 2.13 8.17 2.61 0.48* left 7.98 1.93 8.11 2.50 0.75* total 15.83 3.41 16.28 4.63 0.56* (t-test: two sided) significant level: ***p <.001;**p> 0.01; *p >.05; n.s., not significant. zainab f.doc j bagh college dentistry vol. 27(3), september 2015 the effect of addition restorative dentistry 50 the effect of addition of hydroxyapatite microscopic fillers on surface roughness and some mechanical properties of heat cured acrylic resin zainab salih abdullah, b.d.s., m.sc. (1) abstract background: this study aimed to evaluate the effect of addition of hydroxyapatite micro filler in three concentrations (5%, 10%, 15%) on surface roughness, impact strength, flexural strength and hardness. material and methods: one hundred sixty acrylic samples were used in this study,40 samples were used for each test(impact strength ,flexural strength ,hardness and surface roughness).the test group divided into four subgroups(n=10) for controlgroup,5%,10% ,15%h,a.concentration addition groups .impact testing device, flexural strength testing device, shore hardness tester and profilometer device were used to measure the four tests examined in this study. results: the results showed a significant increase in impact strength, hardness in all concentrations added to heat cured acrylic resin, highly significant decrease in flexural strength, a non-significant difference in surface roughness test in 5% concentration while there was a significant differences in other two concentration in the same test. conclusion: the 5% concentration hydroxyapatite addition was the concentration of choice to be used to increase the mechanical properties (impact strength) of heat cured acrylic resin without increasing the surface roughness of the material. key words: heat cure acrylic resin, hydroxy apatite micro filler. (j bagh coll dentistry 2015; 27(3):50-54). introduction polymethylmethacrylate (pmma) resin was the most common used material in fabrication of denture base and denture teeth due to its preferable properties of both mechanical and physical ,good aesthetic appearance, low cost and also a good compatibility with oral tissues (1).the problem with this material according to its use with patient was the weakening during usage as its break after dropping or after flexing (2).as this material still far from ideal because of some shortcomings related to its mechanical properties like hardness, impact strength and flexural strength (3). the improvement attempts of (pmma) material in order to be more strong and usable was done by using several additives methods like fibers which include different types like glass fibers, polyester and polypropylene fibers in different lengths and concentrations (4-6). another attempts focused on using powders or fillers like silica, titanium oxide and aluminiume oxide also in different concentration and different methods of addition (7,8).one of methods of improvement of (pmma) properties was the addition of hydroxy apatite fillers(h.a.) which was widely used due to its excellent compatibility with tissues and skin (9). h.a. of chemical formula ca10 (po4)6(oh)2 was used recently as a microfiller material to improve the mechanical properties as its reinforce the polymer matrix (10,11). calcium to phosphate ratio ca/p=1.67 (12).there was two different forms of h.a. either nanoscopicormicroscopic fillers, (1) lecturer, department of prosthodontics, college of dentistry, university o baghdad. the microscopic one was widely used in dentistry as it mixed easily with dental resin to obtain the needed improvement (12). in this study, a microfiller form of h.a. in three different concentrations was used and studied its effect on impact strength, flexural strength, hardness and surface roughness. materials and methods one hundred sixty samples were used in this study, these samples were divided into 4 groups, each group consisted of 40 samples for each test. four tests were examined in this study (impact strength, flexural strength, hardness and surface roughness). for each test the forty samples were subdivided into four groups (n=10) these groups consisted of control group,5% h.a. concentration group,10% h.a. concentration group,15% h.a. concentration group. the materials used in this study were: heat cure acrylic resin (vertex) (germany), dental stone (type iii, zermack, italy), hydroxyapatite microfiller (particles size (0.66μm), riedel-de haën ag in seelze hannover, germany. preparation of samples moulds of stone were made for each test according to the measurements specified for each test, for impact strength test used a metal pattern of (80mm*10mm*4mm) length, width and thickness respectively. for flexural strength, hardness and surface roughness used a metal pattern of (65mm*10mm*2.5mm) length, width and thickness respectively. j bagh college dentistry vol. 27(3), september 2015 the effect of addition restorative dentistry 51 these moulds were coated with separating medium and left for 10 minutes to dry and then packed with acrylic resin. p/l ratio for mixing was 2.5g:1g according to manufacturer instructions, the microfiller h.a. was mixed with polymer (13) in a mixing jar in three different concentrations 5%, 10% and15%.the mixing of acrylic was done and packed in a dough stage in moulds specified for each test and then cured to make the samples. the curing process was done according to ada specification no. 12, 1999. firstly by heating the dental flask in water bath in 74oc for 1.5 hr and then raising the temperature to boiling for 30 minutes, cooling for 30 minutes in room temperature and for 15 minutes under water tap .after that the samples were removed, finished, polished and stored in a distilled water in 48 hr to be ready for testing. testing procedures of samples: 1surface hardness test: this test was done by using shore d hardness tester th210.the hardness numbers comes from penetration depth.the numbers were read from the tester gauge. 2-surface roughness test: the profilometer device was used to this test after using h.a. micro filler to examine the micro geometry of the surface of the sample. this device contained surface analyzer (sharp stylus) made from diamond. maximum distance used for the test is 11 mm. the analyzer was directed on the surface of the sample at a right direction in which the sample was placed on stable stage, the traverse length was 11mm. 3-flexural strength it was tested by using flexural testing device according to iso/dis 1567 international standard (14). the test was carried out in air at 21±1oc.aload was applied using a centrally located rod until the fracture happened .the span of 3point bending was 50mm. the ultimate flexural strength (mpa) was calculated by using the following formula. x=3*f*i/2*b*h2 x=flexural strength (mpa),f=the maximum load applied (n), i=the span between the two supports(mm), b=the width of the sample (mm), h=thickness of the sample(mm). 4-impact strength it was tested by impact testing machine by using un-notched samples, the pendulum of s2 scale in an air at 23o c. recording the air resistance (ar) which is (0.9) joules by making the pendulum swing freely in an air. on s2 scale on pointer which was stabilized after swing. the energy absorbed (ea) to break the samples was recorded on s2 scale. impact strength of samples were calculated by using a formula: i=(ae-ar)*103/xy (15). i=impact strength, ea=absorbed energy, ar=air resistance, x=sample thickness (mm) y=sample width (mm) mean, sd were calculated for each group (control, 5%,10% and 15% concentration groups) and for each test. anova test was used to compare between groups in each test to produce the results of this study. results table (1) showed means, sd of control group and the three different concentration groups (5%, 10%, 15%) of h.a. micro fillers for hardness and surface roughness tests. in table (2) anova test showed a significant difference between the four groups of shore hardness test, a highly significant difference between the four groups of surface roughness test. lsd test revealed a significant difference between control and 10% h.a. concentration group and between control and 15% h.a. concentration group in hardness test of studied groups with a non significant difference between control and 5% concentration groups in the same test. a non-significant difference between control and 5% h.a. concentration groups but, a highly significant differences between control group and 10% h.a. concentration group and between control and 15% h.a. concentration group in surface roughness test .also this table showed a highly significant differences between the three different concentrations (5%, 10%, 15%) in surface roughness test of studied groups. table (3) showed means, sd of impact and flexural strength of the four studied groups. in table (4) anova test showed highly significant differences between the groups of both impact and flexural strength tests. lsd test showed a significant difference between control and 5% concentration group and between 10% concentration and 15% concentration groups, also this table showed a highly significant difference between the remaining groups of impact strength test. a highly significant difference between all groups of flexural strength test. j bagh college dentistry vol. 27(3), september 2015 the effect of addition restorative dentistry 52 table 1: descriptive statistic of hardness and surface roughness test of control and h.a. reinforced heat cure acrylic resin samples (5%, 10%,15%) concentrations. hardness control 5% h.a 10% h.a 15% h,a surface roughness control 5% h.a 10% h.a 15% h,a mean 83.09 83.59 84.12 84.15 mean 0.75 0.64 1.67 2.88 sd 1.45 0.89 0.72 1.01 sd 0.52 0.50 0.53 0.50 se 0.46 0.28 0.23 0.32 se 0.17 0.16 0.17 0.16 min 80.80 82.40 83.00 82.26 min 0.10 0.12 1.20 2.20 max 85.60 85.26 85.50 85.30 max 1.20 1.21 2.41 3.31 table 2: anova test of hardness and surface roughness and lsd between the studied groups. anova of shore hardness test anova of surface roughness test df f-test p sig df f-test p sig between groups 3 between groups 3 within groups 36 2.25 0.049 s within groups 36 40.87 0.000 hs total 39 total 39 lsd mean difference p sig lsd mean difference p sig control&5% h.a 0.503 0.293 ns control&5% h.a 0.104 0.645 ns control&10% h.a -1.027 0.036 s control&10% h.a -0.921 0.000 hs control&15% h,a -1.056 0.031 s control&15% h,a -2.133 0.000 hs 5% h.a&10% h.a -0.524 0.274 ns 5% h.a&10% h.a -1.025 0.000 hs 5% h.a&15% h,a -0.553 0.249 ns 5% h.a&15% h,a -2.235 0.000 hs 10% h.a&15% h,a -0.029 0.951 ns 10% h.a&15% h,a -1.211 0.000 hs table 3: descriptive statistic of impact and flexural strength test of control and h.a. reinforced heat cure resin samples (5%, 10%,15%) concentrations. impact strength kj/m2 control 5% h.a 10% h.a 15% h.a flexural strength mpa control 5% h.a 10% h.a 15% h.a mean 5.57 6.60 8.13 9.09 mean 62.849 51.626 44.904 27.274 sd 1.09 0.66 0.17 0.28 sd 1.006 0.659 0.391 1.072 se 0.35 0.21 0.05 0.09 se 0.318 0.208 0.124 0.339 min 4.12 5.55 7.89 8.85 min 61.4 50.89 44.2 25.22 max 7.90 7.76 8.40 9.76 max 64.60 52.86 45.40 28.35 table 4: anova test of flexural strength and impact strength and lsd between the studied groups. anova of impact strength anova of flexural strength f-test p sig f-test p sig between groups 3 56.51 0.000 hs between groups 3 32.23 0.000 hs within groups 36 within groups 36 total 39 total 39 lsd mean difference p sig lsd mean difference p sig control&5% h.a -1.029 0.001 hs control&5% h.a -17.63 0.000 hs control&10% h.a -2.56 0.000 hs control&10% h.a -24.36 0.000 hs control&15% h.a -351 0.000 hs control&15% h.a -35.57 0.000 hs 5% h.a&10% h.a -1.53 0.000 hs 5% h.a&10% h.a -6.722 0.000 hs 5% h.a&15% h.a -2.489 0.000 hs 5% h.a&15% h.a -17.94 0.000 hs 10% h.a&15% h.a -0.957 0.003 s 10% h.a&15%h.a -11.22 0.000 hs j bagh college dentistry vol. 27(3), september 2015 the effect of addition restorative dentistry 53 discussion although the wide usage of heat cure acrylic resin in fabrication of denture base for several years, but this material might be fractured easily during usage due to insufficient resistance of impact and flexural strength (16). in order to improve these properties of acrylic resin material to withstand the load during usage of the prosthesis we added in this study h.a. micro filler for this reason. so firstly we discuss the effect of h. a. fillers addition on hardness, in table (2) we saw a non significant effect of fillers addition in 5% concentration while a significant effect with the other two concentrations (10%,15%) as compared with the control group, this may be explained by a random attribution of the fillers in acrylic matrix (17).the increase of hardness with increase percentage of the fillers due to increase fillers accumulation in acrylic resin matrix, this come in agreement with hu et al (18). in surface roughness test we saw a non significant difference in 5% concentration addition, but a highly significant differences in the other two concentrations (10%, 15%) as showed in table (2) also, this can be explained by that the small concentration added of the fillers make them well dispersed in the matrix and only a few amount may be involved in the surface of acrylic resin (19), on other hand the increase in the concentration of the filler (10%,15%) this may be lead to increase the material filler on the surface of heat cure acrylic resin samples so lead to a significant increase of surface roughness ,this come in agreement with abdul ameer (20). in table (4) the flexural strength showed a highly significant decrease among the four groups (control, 5%, 10% and15% concentration)groups this significance can be explained by the lacking of interfacial bonding between resin matrix and the fillers (21,22). impact strength also showed a highly significant increase between the four groups as showed in the same table and this due to the formation of microfiller/ polymer efficient network leading to the transferring of pmma chains to form a network chains and thus lead to the reduction of segmental motion and improving of impact strength (23). we concluded from this study that the usage of 5% concentration of h. a. micro filler is the most effective concentration because there was no effect on surface roughness increasing with a significant increase of impact strength. references 1. meng tr, latta ma. physical properties of four acrylic denture base resins. j contemp dent pract 2005; 6: 93-100. 2. amjad r. impact strength of acrylic resin denture base material after the addition of different fibers. pakistan oral and dental j 2009; 29: 181-3. 3. vallitta pka. review of fiber reinforced denture base resins. j prosthodont 1996; 5: 270-6. 4. wieslaw h. mechanical strength of an acrylic resin palatal denture base reinforced with mesh or bundle of glass fibers. int j prosthodont 2007; 20: 311-12. 5. hachem tm, abdullah zs, alousi yt. evaluation of the effect of addition of polyester fibers on some mechanical properties of heat cure acrylic resin. j bagh coll dentistry 2013: 25(special issue1): 23-9. 6. mohammed iw. the effect of addition of un treated and oxygen plasma treated poly propylene fibers on some properties of heat cured acrylic resin". (a comparative study) m.sc. thesis, college of dentistry, baghdad university, 2013. 7. jasim sb. the effect of silanized alumina nano fillers addition on some physical and mechanical properties of heat cured polymethylmethacrylate denture base material. m.sc. thesis, college of dentistry, baghdad university, 2013. 8. safi in. evaluation of the effect of modified nano fillers addition on some properties of heat cured acrylic resin denture base material. m.sc. thesis college of dentistry, baghdad university, 2011. 9. singh a. hydroxyapatite, a biomaterial: its chemical synthesis, characterization and study of biocompatibility prepared from shell of garden snail, helix aspara. bulletin materials sci 2012; 35(6): 1031-8. 10. defne b. cuneyt t. chemical preparation of carbonated carbonated calcium haydroxyapatite powders at 37c in urea-containing synthetic body fluids. j european ceramic society 1999; 19: 2573-9. 11. karakas a, hazar a, ceylan d, dogan m. effect of different calcium precursors on biomimetic hydroxyapatite powder properties. technical university, istanbul, turkey 2012; 121. 12. raul w, anabel l, manuel t. mechanical properties of visible light –cured resins reinforced with hydroxyapatite for dental restoration. dental materials 2002; 18: 49-57. 13. zena j. evaluation of the effect of incorporated hydroxyapatite prepared from dried egg shell on some properties of relined denture base. m.sc. thesis college of dentistry, mosul university, 2013. 14. iso/dis 1567. dentistry: denture base polymers. geneva: international organization for standardization, 1998. p.1-27. 15. mowade tk, dange shp, thakre mb, kamble vd. effect of fiber reinforcement on impact strength of heat polymerized polymethyl methacrylate denture base resin: in vitro study and sem analysis. j adv prosthodont 2012; 4(1): 30-6. 16. amjad r. impact strength of acrylic resin denture base material after the addition of different fibers. pakistan oral and dental 2009; 29: 181-3 17. keith hl, chanakya m, perrotta aj, kari w, willims fs. aluminum oxide; in uiimann's encyclopedia of industrial chemistry, wiley-vch, weinheim. 2002. doi:10.1002/14356007.01-557. j bagh college dentistry vol. 27(3), september 2015 the effect of addition restorative dentistry 54 18. hu y, zhou s, wu l. surface mechanical properties of transparent pmma/ zirconia nanocomposites prepared by in situ bulk polymerization. polymer 2009; 50: 3609-16. 19. al-momen mm. effect or reinforcement on strength and radio-opacity of acrylic denture base materials. m.sc. thesis, college of dentistry, university of baghdad, 2000. 20. abdul-ameer as. evaluation of changes in some properties of acrylic denture base material due to addition of radio-opaque fillers. m.sc. thesis, college of dentistry, university of baghdad, 2006. 21. ash bj, siegel rw, schadler ls. mechanical behavior of alumina/ poly (methyl methacrylate) nanocomposites. macromolecules 2004; 37:1358-69. 22. noori ah. evaluation of thermal conductivity of alumina reinforced heat cure acrylic resin and some other properties. m.sc. thesis, college of dentistry /university of baghdad, 2010. 23. singh d, jayasimha t, rai kn, kumar a. preparation of pmma nanocomposite with superior impact strength. j appl polym sci 2007; 105(6): 3183-94. الخالصة ضافة مادة الھیدروكسي ابیتایت المایكرو على خشونة السطح وبعض الصفات المیكانیكیة لمادة قاعدة الطقم الراتنج الھدف من ھذا البحث ھو بیان تاثیر ا كل مجموعة تتكون نموذج وقد قسمت النماذج الى اربعة مجموعات 160وقد تم استخدام ,صالدة السطح وقوة الطي ومقاومة الصدمھ االكریلك الحراري وھي ال % 5وقد اظھرت نتائج ھذا البحث ان استخدام تركیز % 15,% 10,% 5وقد تم اضافة الھایدروكسي ابیتایت بثالثة تراكیز , نموذج لكل خاصیة 40من .یؤثر على خشونة السطح ویظھر زیادة ملحوظة على مقاومة الصدمة j bagh college dentistry vol. 30(4), december 2018 immunohistochemical 16 immunohistochemical expression of endocan, as a marker of assessment of angiogenic potential in benign vascular lesions (hemangioma, lymphangioma and lobular capillary hemangioma) of head and neck region jawaher m.tater.b.d.s. (1) bashar h. abdullah, b.d.s., m.sc., ph.d. (2) wisam a.hussain, f.i.c.m. pathology (3) abstract background: the biological behavior of vascular tumors ranging from a hamartomatous growth to frank malignant. the pathophysiology of vascular malformation, hemangioma and lymphangioma is interrelated, blood vessels known to be the site of origin of venous malformations, hamartomas and some neoplasms as benign, tumor-like growth of vessels (hemangiomas). angiogenesis is the process of formation of new blood vessels from an existing structure. aims of study assessment of angiogenic potential in benign vascular lesions (hemangioma, lymphangioma and lobular capillary hemangioma) of head and neck region. materials and methods: twenty formalin-fixed paraffin-embedded tissue blocks of lymphangioma, thirty of lobular capillary hemangioma and another twenty-two of hemangioma/vascular malformation to be stained with ndothelial cell-specific molecule-1 (esm-1) monoclonal antibody. results: microvessel density expressed by endothelial cell-specific molecule-1 (esm-1) immunomarker was found in all cases with mean density of (25.02±13.89) for hemangioma and (37.44±23.16) for lobular capillary hemangioma and (6.34±3.52) for lymphangioma. along with post hoc test esm-1 marker expression showed a high significant difference between (lymphangioma and hemangioma =0.001), (lymphangioma, pyogenic granuloma=0.000), and it was significantly different between (hemangioma, pyogenic granuloma=0.011) conclusions: the obvious capillary growth in lobular capillary hemangioma revealed that lobular capillary hemangioma showed the highest activity of angiogenic potential in comparison to hemangioma and lymphangioma. keywords: endocan,vascular tumor,angiogenic potentional. (received: 15/7/2018; accepted: 28/8/2018) introduction: vascular system is a highly heterogeneous and non-identical organ system, hence to make a judgment whether the entire lesion is composed of only venous component or whether there is a lymphatic channels cannot be easy(1). to increase the flow of blood to ischemic tissue the human body grows new blood vessels from an existing structure, the process of formation of new blood vessels termed angiogenesis (2). vascular development starts by the gathering of a vessel plexus from single cell precursors, adjustment then undergoes to this plexus by sprouting growth and remodeling (angiogenesis), followed by recruitment of vessels into target tissues, finally according to the specific needs of the tissue, new vessels differentiate. (3) endocan also named as endothelial cellspecific molecule-1(esm-1) has acted since its detection as a dermatan sulfate proteoglycan, with unique functional and structural properties. endothelial cells naturally expresses esm-1 , a highly controlled in existence of proinflammatory and proangiogenic molecules, binds to growth factors, matrix proteins, integrin and cells, and considered as an precise marker of endothelial activation (4). materials and methods the sample is consisted of twenty formalin fixed paraffin embedded tissue blocks of lymphangioma, thirty of lobular capillary hemangioma and another twenty-two of hemangioma/vascular malformation. the samples gained from the archives of al-shaheed ghazi hospital/ medical city / baghdad and the department of oral & maxillofacial pathology/college of dentistry/ university of baghdad & dated from (1979 till 2015). after histopathological reexamination of haematoxylin and eosin stained sections for all blocks, an immunohisto-chemical staining was achieved using endocan, assessment mvd based on the criteria of weidner (5). (1) department of oral diagnosis, college of dentistry, al-mustansyria university. (2) professor. head of department of oral and maxillofacial pathology, college of dentistry, university of baghdad. (3) pathologist, ghazi alhariri hospital, ministry of health. j bagh college dentistry vol. 30(4), december 2018 immunohistochemical 16 results esm-1 expression the immunostaning procedure of esm1 was applied to hemangioma, pyogenic granuloma and lymphangioma, where the endothelial cells of blood vessel were stained with brown coloration as seen in (figures 1,2 , 3,4and 5). in (table 1), the mean±sd of mvd assessed by esm-1 immunomarker expression, in relation to anova test imploded between samples groups. there was a high statistical significant difference in the mean of expression of esm-1 in pyogenic granuloma in comparison to lymphangioma and hemangioma (p=0.000). table (1): description of statistics gained by immunohistochemistry of esm-1 numerous comparisons were made between lymphangioma, hemangioma and pyogenic granuloma with endocan marker as stated by post hoc test, a highly significant difference was establish between esm-1 expression in( lymphangioma and hemangioma=0.001), (lymphangioma and pyogenic granuloma=0.000) and it was significantly different between pyogenic granuloma and hemangioma (0.011).(table .2). table (2): several statistical comparisons by post hoc test esm-1 dependent variable std. error mean differe nce sig. hemangioma lymphangioma 5.24 18.67 .001** pyogenic 4.76 -12.42 .011* lymphangioma pyogenic 4.89 -31.10 .000** figure (1) a: photomicrograph in lymphangioma showing esm-1 immunostaining negative stain lymphatic vessels and positive blood vessels x100) b: positive blood vessels x400) (thin arrow for lymphatic while, thick arrow for blood vessels esm-1 n sd mean max. min. f sig. hemangioma 22 13.89151 25.0182 62.60 10.00 20.17 0.000 lymphangioma 20 3.51604 6.3400 15.60 2.30 pyogenic granuloma 30 23.16239 37.4400 95.30 8.60 total 72 21.04732 25.0056 95.30 2.30 a b j bagh college dentistry vol. 30(4), december 2018 immunohistochemical 16 figure (2): photomicrograph in lymphangioma display esm-1 immunostaining positive blood vessels (x400) figure (3): photomicrograph in hemangioma viewing esm-1 immunostaining positive blood vessels(x400) figure (4): photomicrograph in lobular capillary hemangioma viewing esm-1 immunostainingpositive blood vessels (x200) figure (5): photomicrograph in lobular capillary hemangioma viewing esm-1 immunostainingpositive blood vessels (x400) discussion this study exhibited the highest positive expression of endocan in lobular capillary hemangioma that is in agreement with previous studies, which determined esm-1 as critical proangiogenic molecule (7), also it agrees with chen ly et al., (8) whom found in vitro that esm1 being over-expressed in the course of angiogenesis. this can be clarified by understanding the pathogenesis of lobular capillary hemangioma at the molecular level that considered as the imbalance between angiogenesis inhibitors and enhancers, that is overexpression of vegf and bfgf and decreased quantity of angiostatin direct to the development of pyogenic granuloma (9). in this study, endocan was positively expressed in lymphangioma and that agrees with shin jw et al., (10) whom clarified that endocan was a potential target for the inhibition of vegfa– or vegf-c– induced pathologic lymphatic vessel growth and activation and considered it as a novel mediator of lymphangiogenesis. in lobular capillary hemangioma the obvious capillary growth (hyperplastic granulation tissue) suggests that there should be a strong activity of angiogenic potential (9). this agree with the findings of the present study, which found that esm-1 expression being higher in lobular capillary hemangioma, which explains the proliferative nature of this lesion. references: 1. jackson it, carreno r, potparic z, hussain k. hemangiomas, vascular malformations, and lymphovenous malformations: classification and methods of treatment. plast reconstr surg 1993;91:1216–30 j bagh college dentistry vol. 30(4), december 2018 immunohistochemical 16 2. igin rk, camrmeliet pf. vascular endothelial growth factor (vegf). scientific american 2001; 2935. 3. johnstone s, logan rm. the role of vascular endothelial growth factor (vegf) in oral dysplasia and oral squamous cell carcinoma. oral oncolo 2006; 42(4), 337-42 4. sarrazin s, maurage ca, delmas d, lassalle p, delehedde m. endocan as a biomarker of endothelial dysfunction in cancer. j cancer sci ther. 2010;2(2):47-52 5. weidner n, semple jp, welch wr, folkman j. tumor angiogenesis and metastasis—correlation in invasive breast carcinoma. new england journal of medicine. 1991 jan 3;324(1):1-8. 6. huang gw, tao ym, ding x. endocan expression correlated with poor survival in human hepatocellular carcinoma. digestive diseases and sciences. 2009;54(2):389-94 7. brütsch r, liebler ss, wüstehube j, bartol a, herberich se, adam mg, telzerow a, augustin hg, fischer a. integrin cytoplasmic domain–associated protein-1 attenuates sprouting angiogenesis. circulation research. 2010;107 (5):592-601. 8. chen ly, liu x, wang sl, qin cy. over-expression of the endocan gene in endothelial cells from hepatocellular carcinoma is associated with angiogenesis and tumour invasion. journal of international medical research. 2010;38(2):498-510. 9. yuan k, jin yt, lin mt. the detection and comparison of angiogenesis-associated factors in pyogenic granuloma by immunohistochemistry. journal of periodontology. 2000;71(5):701-9. 10. shin jw, huggenberger r, detmar m. transcriptional profiling of vegf-a and vegf-c target genes in lymphatic endothelium reveals endothelial-specific molecule-1 as a novel mediator of lymphangiogenesis. blood. 2008;112(6):2318-26. المستخلص هياألورام اللمفية واألورام الوعائية ن مصطلح األورام الوعائية تستخدم عادة لشرح مجموعة متنوعة من اورام االوعية الدموية والتشوهات الخلقية. ا : الخلفية اورام مرتبطة فسلجيا.تعتبر االوعية الدموية هي المصدر الرئسي المولد لالورام الوعائية , في منطقة الراس والرقبة. األورام اللمفيةواألورام الوعائية القابلية لتكوين االوعية الجديدة في لتقييم : تهدف هذه الدراسة األهداف عينة 23عينة للورم الوعائي الشعرية المفصص و 03عينة للورم الوعائي معالج بالفورمالين والمغمور بالبارافين و 22:في هذه الدراسة العمل وطرائق المواد .معت من ارشيف المختبرات تضمنت خالل هذه الدراسةاخرى للورم اللمفي ج لألورام الوعائية الشعرية (23.16±37.44)قد وجدت في جميع الحاالت وبمعدل esm-1 : كثافة االوعية الدموية الموضحة من خالل االجسام المناعيةالنتائج اللمفية .بالنسبة لألورام (3.52±6.34)لألورام الوعائية (13.89±25.02) المفصصة .مفيةاألورام اللوألورام الوعائية االمقارنة مع ية من االوعية الدموية بتظهر نسبة عال ةالشعرية المفصص ورام الدمويةلاللالواضح التطور الوعائيا :االستنتاجات chenar f.doc j bagh college dentistry vol. 25(2), june 2013 the effect of intracrevicular oral and maxillofacial surgery and periodontics 125 the effect of intracrevicular injection of fucose on serum interlukine -1beta and tumor necrosis factor alpha chenar a. mohammad (1) khlood a. al-safi (2) bakhtiar m. ahmed (3) abstract background: α-l-fucose is a methyl pentose sugar, had the ability to kill bacteria, controlling infection and normalize immune function. the objective of this study is to determine the effect of sulcular injection of fucose on rabbits periodontium , throughout measuring the level of some proinflammatory cytokine ; interlukine 1beta ( il-1beta) and tumor necrosis factor ( tnf-alpha) in sera of rabbits before fucose injection and at 3 days after fucose injection. materials and methods: the study was carried on using ( 20 ) male rabbits of the same species weighted (1-1.5 kg ) , the blood samples were collected from hearts of 20 rabbits before fucose injection and consider as( non injected group) , and after 3 days of fucose injection and consider as (fucose injected group) and analyzed for determination of the concentration of il-1ß and tnf-α. results: the results showed a highly significant decrease in the mean concentration of tnf-α in sera of fucose injected group(19.05± 1.166) pg ⁄ml when compared to its mean concentration in non injected group (27.25±7.371) pg ⁄ml ,also a highly significant decrease in the mean concentration of il-1ß in sera of fucose injected group(34.19 ± 3.1)pg ⁄ml as compared to its mean concentration in sera of non injected group (38.86 ±4.565)pg⁄ml. conclusion: both proinflammatory cytokines were influenced and inhibited by local fucose injection key words: α-l-fucose , interlukine 1beta (il-1ß), tumor necrosis factor (tnfα) . (j bagh coll dentistry 2013; 25(2):125129). introduction fucose (6-deoxy-l-galactose) is a monosaccharide that is found on glycoprotein and glycolipids in vertebrates, invertebrates, plants, bacteria¹, and is present in low concentration in normal serum but is increased in diabetes, cancer, and inflammatory diseases². a study found that fucose containing glycans modulated a wide range of physiological processes, such as; cell migration, proliferation, embryogenesis, fetal development, nurontransmission, leukocytes adhesion, signal transduction and apoptosis 3. fucose is a powerful immune modulator. it is distributed in macrophages, (which are largest white blood cells in the body) which are critically important to immune function, its necessity in immune function, especially that of an overactive immune system, the cause of autoimmune disorders, so fucose is well-documented as playing a vital role in immune function ². inflammation is one of the first responses of the immune system to an infection, irritation or tissue injury, and the local response to an infection or tissue injury involves production of cytokine, which are released to site of inflammation 4. (1)phd student, periodontology, college of dentistry, hawler medical university. (2)professor, periodontology, college of dentistry, baghdad university. (3)assistant professor, basic science, clinical and oral biochemistry , college of dentistry, hawler medical university, erbil, iraq inflammation is stimulated by chemical factors released by injured cells and serves to establish a physical barrier against the spread of infection, and to promote healing of any damaged tissue following the clearance of pathogens 5. these chemical factors produced during inflammation (histamine, bradykinin, serotonin, leukotrienes also prostaglandins) sensitize pain receptors, cause vasodilation of the blood vessels at the scene, and attract phagocytes, especially neutrophils 5. neutrophils then trigger other parts of the immune system by releasing factors that summon other leukocytes and lymphocytes. cytokines produced by macrophages and other cells of the innate immune system mediate the inflammatory response. these cytokines include tnf and il-1 6 6. researchers found that alphal-fucose has been demonstrated to inhibit lymphokine activity in vitro are effective in suppressing in vivo manifestation of cellular immunity 7, other study suggested that alpha lfucose suppresses contact allergy by locally inhibiting the efferent phase of the cellular immune response 8. a fucose–containing glycoprotein fraction which stimulates spleen cell proliferation and cytokine expression has been identified from the water–soluble extract of ganoderma luicedum, further studies on the activities of this glycoprotein fraction through selective proteolysis and glycosidic cleavage indicate that a fucose containing polysaccharide fraction is j bagh college dentistry vol. 25(2), june 2013 the effect of intracrevicular oral and maxillofacial surgery and periodontics 126 responsible for stimulating the expression of cytokines, especially il-1, il-2 and inf-gamma 9. another study, described the isolation of reishi polysaccharides for the study of their effect on cytokine expression in mouse splenotypes, a fraction(f3) has been shown to activate the expression of il-1,il-6,il-12,ifngama, and tnf-alpha, and from this three subfractions have been prepared where f3g1 activates il-1,il-12,and tnf-alpha , f3g2 activates all the cytokines as f3 does , and f3g3 activates only il-1 and tnf-alpha 10. materials and methods 1setting of the study: the present study was carried out in erbil city, hawler medical university, college of dentistry, department of basic science, and medical research center. 2experimental animal: twenty rabbits were used, these 20 rabbits were used as a non injected group ( group a) that not receive any injection of fucose; and the same 20 rabbits were received intra crevicular injection of a single dose of fucose solution of 50 µl fucose / kg rabbit weight and of a concentration of 150 mm fucose in normal saline 0.9% nacl, into midlabial area of lower right central incisor and consider them as a fucose injected group, the blood samples were collected from 20 rabbits heart (cardiac puncture) ¹¹ before fucose injection and after 3 days of intracrevicular injection of fucose. 3-sulcular injection technique and administration of l-fucose sulcular injection techniques are standard techniques which are used most often to achieve nerve block and infiltration anesthesia in dentistry. in this technique the needle is inserted gently approximately 5 mm into the gingival tissue at the bottom of the gingival sulcus of lower right central incisor and a small amount of solution is injected slowly, and the amount of solution was delivered to each site over a period of approximately ten seconds ¹². fucose was infiltrated through the labial gingival tissue of the lower right central incisor using disposable insulin syringe (0.33×13mm) 13. 4-sampling blood sample had been collected from rabbitś heart (cardiac puncture)11 of 20 rabbits by using disposable syringes of (5 cc syringes), the animals were anesthetized and restrained in dorsal recumbency then the needle (21 gauge needle) was inserted under the xyphoid cartilage slightly to the left of midline. the needle is advanced at a 20 to 30 degree angle from the horizontal axis to the sternum to enter the heart. the blood should be withdrawn slowly, four ml of blood were collected from each rabbit before fucose injection , then the samples were transferred into sterilized glass tubes( gel tubes), quitting for 30 minutes for clotting and centrifuged at 3000 rpm for 5 minutes to obtain clear supernatant, the serum was separated and transferred into sterile screw capped labeled tubes and stored at -20 c for subsequent analysis of proinflammatory cytokine il-1 beta , tnfalpha , and the same procedure of blood collection was done for the same 20 rabbits after 3 days of fucose injection. . 5-methods adetermination of serum tnf-alpha using indirect elisa technique. . 1-all reagents and serum samples were brought to room temperature. 2-standered was diluted to 1µg/ml with distilled water. then serial dilution of the standard (1000, 500,250, 125, 62.5, 31.25, 15.625, 7.8125 pg/ml) were prepared from the original standard. . 3200 µl of assay buffer was pipette into the appropriate microtiter wells. the wells were aspirated to remove liquid, and then each plate was washed 4 times by using 300 µl of washing solution. after the last wash, the plate was inverted to remove residual solution and blotted on paper towel. 4100 µl of standard, sample, and control groups were pipetted into the wells, and then covered with plate sealer, incubate at room temperature for 2 hours. . 5after incubation, the plates were aspirated to remove liquid, then washed 4 times with diluted wash buffer. the wells were inverted and taped dry on paper towel. . 6100 µl of the diluted detected antibody ( diluted streptavidin-hrp conjugate 0.5µg/ml) were added to each well, then covered with plate sealer , and incubated at room temperature for 2 hours. 7the plates were aspirated to remove liquid, and then washed 4 times with diluted wash buffer. the wells were inverted and taped dry on paper towel. 8100 µl of the diluted color development enzyme( readyto-use-tmb substrate solution) were added to each well, and then covered with plate sealer and incubated at room temperature for 30 minutes. 7 the plates were aspirated to remove liquid, and then washed 4 times with diluted wash buffer. 9100 µl of color development solution was added to each well, covered, and then incubated at room temperature for a proper color j bagh college dentistry vol. 25(2), june 2013 the effect of intracrevicular oral and maxillofacial surgery and periodontics 127 development for 4minutes. 100 µl of the stop solution was added to each well in order to stop the color reaction. 9the absorbance of the well contents were read at 450 nm , by using a microliter plate reader. 10the tnf-alpha concentration of unknown samples and control groups were calculated from the following equation. concentration of tnf-alpha = od test × concentration of standard od standard bdetermination of serum il-1 beta using indirect elisa technique . 1-all reagents and serum samples were brought to room temperature 2-standered was diluted to 0.1µg/ml with distilled water .then serial dilution of the standard (125, 62.5, 31.25, 15.625, 7.8125 pg/ml) were prepared consecutively from the original standard. 3200 µl of washing solution ( pbst) was pipette into the appropriate microtiter wells. the wells were aspirated to remove liquid, and then the plate washed 3 times with 300 µl of washing solution .after the last wash, the plate was inverted to remove residual solution and blotted on paper towel. 4100 µl of standred, sample, and control groups were pipette into the wells, then covered the plate with plate sealer, and incubated at room temperature for 2 hours. 5-the plate was aspirated and washed 4 times with diluted wash buffer. . 6-100 µl of the diluted detected antibody (0.5µg/ml) was added to each well, then covered with plate sealer, and incubated at room temperature for 2 hours. . 7at the end of incubation time, the plate was aspirated and washed 4 times with diluted wash buffer. 8100 µl of the diluted color development enzyme was added to each well, then the plate was covered with plate sealer and incubated at room temperature for 30 minutes, at the end of incubation time, the plate was aspirated and washed 4 times. 9100 µl of color development solution was added to each well .covered, then incubated at room temperature for a proper color development for 4 minutes, 100 µl of stop solution was added to each well to stop the color reaction. 10the absorbance of the well contents were read at 450 nm, by using a microtiter plate reader. 11the il-1 beta concentration of unknown samples and control groups were obtained from the following equation: concentration of il-1 beta = od test × concentration of standard od standard results table 1 and figure 1 showed that there was a high significant decrease in the mean concentration of tnf-α in sera of rabbits after fucose injection (19.05±1.166 pg ∕ml) when compared with its mean concentration in sera of same rabbits before fucose injection (27.25±7.371 pg∕ ml). also a high significant decrease in the mean concentration of il-1beta in sera of rabbits after fucose injection (34.19±3.1pg∕ ml) when compared to its mean concentration in sera of same rabbits before fucose injection (38.86±4.565pg∕ ml), as shown in table 2 and figure 2. . table1: the mean concentration of tnfα(pg ⁄ml) in sera of non injected and fucose injected groups. sig. ±se mean ± sd range of conc. number study groups hs 1.648 27.25±7.371 19.849.4 20 non injected 0.261 19.05±1.166 15 20.4 20 fucose injected table 2: the mean concentration of il-1 beta (pg ⁄ml) in sera of non injected and fucose injected groups. sig. ±se mean ± sd range of conc. number study groups hs 1.021 38.86±4.56 32.5-46.1 20 non injected 0.693 34.19± 3.1 30.3-39.3 20 fucose injected j bagh college dentistry vol. 25(2), june 2013 the effect of intracrevicular oral and maxillofacial surgery and periodontics 128 27.25 19.05 0 5 10 15 20 25 30 non injected fucose injected study groups m e an c o n c. o f tn fα p g/ m l. figure 1: the mean concentration of tnf-α (pg ⁄ml) in sera of non injected and fucose injected groups. 38.86 34.185 31 32 33 34 35 36 37 38 39 40 non injected fucose injected study groups m e an c o n c. o f il -1 β p g/ m l. figure 2: the mean concentration of il-1beta (pg ⁄ ml) in sera of non injected and fucose injected groups. discussion 1serum il-1ß the present study demonstrated that local injction of fucose was significantly associated with serum level of il-1 beta ,and a highly statistically significant decrease in serum concentration of il-1 beta were observed in fucose solution injected group compared to the non injected group . this result was in agreement with that found by other researchers 14,15, 16,7,8 , rocklin14, found that l-fucose capable of inhibiting lymphokine activity in vitro , and found that human microphage inhibition factor ( mif) activity on blood monocyte was significantly reduced by l-fucose , also remold15 , strongly suggested that alpha-l-fucose comprises an essential part of the macrophage membrane receptor to migration inhibition factor, and he showed that alpha-l-fucose abolishes the activity of guinea pig migration inhibitory factor (mif) on the macrophages, so macrophages no longer responded to mif . also baba et al 7 studied the effect of α-l-fucose on cell mediated immunity in vivo, and found that l-fucose injected intravenously could inhibit the ability of lymphokine containing supernatants to induce skin reaction or cause reduction in the macrophage content of peritoneal exudates, moreover, l-fucose can inhibit the cutaneous delayed hypersensitivity reaction and the periotoneal macrophage disappearance reaction ( mdr) induced by antigen in actively immunized guinea pigs, the result demonstrated that monosaccharides capable of inhibiting lymphokine activity in vitro are effective in suppressing in vivo manifestation of cell mediated immunity . knop and reichman8 suggested that local application of α-l-fucose on the ear before elicitation of contact allergy to dinitroflurobenzene (dnfb) in mice results in a suppression of the contact allergic response by locally inhibiting the efferent phase of the cellular immune response. clark etal 16 ., studied cytokine in animal model (vivo and vitro studies), in vivo model , they measured the amount of rabbit il-1alpha and il-1 beta protein present in brain, kidney, liver, lung, muscle, and spleen at various times after the injection of endotoxine , and found that il-1 present all tissues studied but largely in spleen; and found that il-1 levels were transient , reaching peak levels by 4 h after injection and rapidly decreased to low levels by 24h, and in vitro studies il-1beta was maximal at 24h then decreased. . in contrast this result was in j bagh college dentistry vol. 25(2), june 2013 the effect of intracrevicular oral and maxillofacial surgery and periodontics 129 disagreement with that found by other researchers 9 ,wang et al 9., found that a fucose containing polysaccharide fraction is responsible for stimulating the expression of cytokines, especially il-1. 2serum tnf-α regarding tnf-alpha, the present study demonstrated a high statistically significant differences was found between fucose solution injected group and non injected group , and the mean concentration of tnf-alpha in sera of non injected group was 27.25 and decrease to 19.05 in fucose injected group, this result was in agreement with that found by other researches7, 8 17 , baba et al7., found that l-fucose capable of inhibiting lymphokine activity in vitro and was effective in suppressing in vivo manifestation of cellular immunity, and knop and riechman8, suggested that local application of α-l-fucose suppresses contact allergy by locally inhibiting the efferent phase of the cellular immune response , also stankova 17, found that fucose induced significantly higher secretion of tnfalpha by both lymphocytes and monocytes, and found that fucose induced the accumulation of tnf-alpha accumulation in a time – dependent manner with a peak concentration at 8 hours and returned to baseline values at 20 hours after stimulation, in contrast to our finding, chen etal 10., reported that ganoderma luicedum ( reishi) polysaccharide (f3) and there sub fractions (f1,f2,and f3) all activated the expression of tnf-alpha. references 1. moriwaki k, miyoshi e. fucosylation and gasterointestinal cancer. word j heptaol 2010; 27; 2 (4):151-61. 2. american international association of nutritional education. fucose. j nutr edu for the world 2006; 23(5):67-69. 3. orczyk-pawilowicz m. the role of fucossylation of glyconjugatas in health and disease. postepy hig med dosw 2007; 61:240-252. 4. pedersen bk. special feature for the olympies: effects of exercise on the immune system. immunol and cell bio 2000; 78:532-5. 5. stvrtinova v, jan j, hulin i. inflammation and fever from pathophysiology: principles of disease. computing centre, slovak academy of sciences 1995. 6. lotze mt, and tracey kj. high-mobility group box 1 protein (hmgb1): nuclear weapon in the immune arsenal. natu revi immunol 2005; 5(4):331-42. 7. baba t, yoshida t, cohen s. suppression of cellmediated immune reactions by monosaccharides. j immunl 1979; 122(3):838-41. 8. knop j, reichmann r. suppression of the elicitation phase of contact allergy by epicutaneous application of alpha –l-fucose 1983; 247(1-2) 155-8. 9. wang yy, khoo kh, chen st et al. studies on the immuno-modulating and antitumor activities of ganoderma luciden (reishi) polysaccharides. functional and proteomic analysis of a fucose containing glycoprotein fraction responsible for the activities. biorg med chem 2002;10(4): 1057-62. 10. chen hs, tsai yf, lin cc et al. studies on the immunomodulating and anti-tumor activities of ganoderma lucidum ( reishi) polysaccharides. bioorg med chem 2004; 1;12(21):5595-601. 11. standardized operating procedure for rabbit immunization and blood collection 2011.university at buffalo. buffalo. 12. peterson je, matsson l, nation w. cementum and epithelial attachment response to the sulcular and periodontal ligament injection techniques. ped dentis american acadey of periodn 1983; 5(4). 13. taka s. the local effects of s2-complex on periodontium. master thesis, college of dentistry, baghdad university. 2001. 14. rocklin re. role of monosaccharides in the interaction of 2 lymphocytes mediators with their target cells. j immunol 1976;116(3):816-20. 15. remold hg. requirement for α-l-fucose on the macrophage membrane receptor for mif. j exp med 1973;38(5):1065-76. 16. clark bd, bedrosian i, schindler r et al. detection of interleukin 1 alpha and 1 beta in rabbit tissues during endotoxemia using sensitive radioimmunoassays. j appl physi 1991; 71(6)2412-8. 17. stanková j. fucose–activated killer cells. i. enhanced tnf-alpha mrna accumulation and protein production. j leukoc biol 1992; 52(2):188-96. 24. zahraa f.doc j bagh college dentistry vol. 27(4), december 2015 cariesexperiences pedodontics, orthodontics and preventive dentistry 147 caries-experiences and dental treatment needs among (16-18 years old) in high school girls in al-mussayb city, babylon governorate zahraa m. al-shammary, b.d.s. (1) sulafa k. el-samarrai, b.d.s., m.sc., ph.d. (2) abstarct background: numerous epidemiological studies were conducted in iraq, concerning dental caries and related etiological factors however; most of these studies were concerned with pre-and primary school children and/or those at index ages (12-15years old). at the time studies regarding older ages are very limited. this study was done to determine the prevalence and severity of dental caries and treatment need among high schools girls (16-18 years old) in al-mussayb city, babylon governorate. thus, it can be considered as a base line data that allows studying dental caries among permanent dentition, also allows the comparison with other studies in other parts of the world. material and method: a total number of 900 high school girls were examined in their classroom following the method of who. dental caries was recorded by application of dmft/dmfs index, and dental treatment needs following criteria of who. results: the prevalence of dental caries was 70.5% with a mean dmft/dmfs values (3.30 ±se 0.091, 4.94 ±se 0.161) respectively. a statistically highly significant increase of caries-experience was recorded with aging. the highest percentage of girls needed one surface restoration (60.8%). conclusion: a relatively high caries – experience was present among high school girl in al mussayb city indicating the need for preventive programs. keyword: dental caries, secondary school students. (j bagh coll dentistry 2015; 27(4):147-149). introduction iraq is one of developing countries that demonstrated a high caries prevalence and severity of dental caries among different age groups however; most of these studies were conducted in bagdad cityand directed to pr-and primary schools (1-3). while there is a limitation in studies concerning (16-18 years old). only two studies wereable to found concerning adolescent from 10-19 years old in humaidat village, mosul governorate and in al-door, salahaldeen governorate (4,5). al-mussayb city, babylon governorate located in the middle euphrates region about 40 km from hilla city. the city is located on the banks of the euphrates river that bisects it in to two halves. an estimated population of almussayb city is (107344) people according to iraqi ministry of planning/ al-mussayb statistics department, 2014. this study was designed in order to have a base line data concerning the prevalence and severity of dental caries in al mussayb city, babylon governorate for 16-18 years old high school girls, and determine the treatment need. materials and methods in the present study, the total number examined consisted of (1100) high school girls (16, 17, 18 years old). (1) m.sc. student. department of pedodontics and preventive dentistry. college of dentistry. (2) professor. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad. permission was obtained from the al mussayb education institution in order to meet subjects with no obligation, also a special consents were distributed to parents to obtain permission for including their girls in the study with full cooperation, girls without permission, and/or with serious systemic diseases, uncooperative, wear orthodontic appliance and married were excluded from total sample. examination was performed in classrooms under standardization criteria of who (6). using disposable mouth mirrors and dental explorers, dental caries was diagnosed and recorded by application of dmft/ dmfs index according to criteria of who (6). the same reference was followed in recording the dental treatment needs. natural day light was used for illuminations supplemented by artificial light. as data were not normally distributed, kruskal-wallis test was applied to test the differences between results. p-value less than 0.05 were considered significant and highly significant if p-value less than 0.01. girls were informed about their dental status and the treatment they need. results the final number of high school girls composed only of (900). table (1) illustrates the distribution of caries-free of high schoolgirls and the dmft values. only (29.5%) were caries-free of total girls examined. j bagh college dentistry vol. 27(4), december 2015 cariesexperiences pedodontics, orthodontics and preventive dentistry 148 table (2) illustrates the mean and median value of dmfs value according to the ages. caries-experience was found to increase with age and difference was highly significant (p< 0.01). ds value component was highest compared to ms. discussion the present study is the firststudy concerning caries-experiences among (16-18 years old) high school girls in almussayb city, babylon governorate. thus it is consider as a base line data to allow comparison with other study in iraq and other part in the world. the prevalence reported by current study was 70.5%, this is considered to be lower than that reported by rebelo et al (7), while this percentage was higher than that reported by rose and vieira in usa (8). this relatively high prevalence of dental caries may be indication of poor dental education in the studied area beside the assumed low fluoride level in communal water supply. pervious iraqi studies reported a fluoride levelin tigris river not more than 0.22 ppm, explaining the increase in dental caries, while no study was able to be found regarding euphrates river so future study is needed to explore the fluoride level in relation to dental health. the mean values of dmft recording by the present study was (3.03 ±se 0.091) which was higher than that recorded by others (9). on the other hand, this value was lower than that recorded by different studies among different populations (10,11). variation between studies in cariesexperiences may be either related to variation in etiological factor and/or associated risk factor (12). in addition variation between studies may be related to differences in the design of the study and diagnostic criteria. in similarity with other iraqi studies, the ds fraction contributed the major part of dmfs index, this may indicate either ignores to treat already existing caries or girls are not even aware of the presence of carious teeth. the neglecting of dental health and the irreversible accumulative nature of dental caries may explain the increase in caries severity recorded with age (13,14). the study showed that nearly 70% of girls were in need of one surface restoration while 8.9% needed pulp care and extraction of teeth. neglecting of dental care and periodic dental visit may allow for progression of dental lesion thus increase in the need for treatment. as conclusion; high caries prevalence can be seen by this study, with increase in dental treatment need indicted the need for public or school preventive programs and improvement of dental health educations. table (1): distribution of caries-free among high school girls and caries -experience by age figure (1): distribution of high school girls according to the type of treatment need required by age. age in years no. caries-free dmft no. % mean ±se median 16 276 91 33.0 2.58 0.151 2.00 17 290 95 32.8 2.99 0.165 2.00 18 334 80 24.0 3.43 0.153 3.00 total 900 266 29.5 3.03 0.091 2.00 j bagh college dentistry vol. 27(4), december 2015 cariesexperiences pedodontics, orthodontics and preventive dentistry 149 table (2): caries-experience (mean, se, median of ds, ms, fs and dmfs) among high school girls by age. **highly significant, p < 0.01, df = 2, # mean rank references 1. al-ani n. oral health status, treatment needs and dental anomalies in relation to nutritional status among 12 year-old school children in heet city/alanbar governorate/iraq. a master thesis, college of dentistry, university of baghdad, 2013. 2. al-jebouri h. oral health status among 15years old in hilla governorate. a master thesis, college of dentistry, university of baghdad, 2007. 3. al-obaidi ej. oral health status and treatment needs among 15 year old students in al-diwania governorate-iraq. a master thesis, college of dentistry, university of bagdad. 4. abdullah a. prevalence of dental caries and associated teeth brushing behavior among iraqi adolescents in aldoor. tikrit med j 2009; 15(2):102-9. 5. gasgoos ss, khamrco ty. prevalence of dental caries, dental health attitude and behavior in humaidat village, nineveh at the entry of 21st century. al– rafidain dent j 2006; 6(1): 15-9. 6. world health organization (who). basic methods of the oral health survey. 3rd ed. geneva, 1987. 7. rebelo m, lopes m, vieira j, parente r. dental caries and gingivitis among 15 to 19 year-old students in manaus, am, brazi braz oral res 2009; 23(3): 24854. 8. rose e, vieira a. caries and periodontal disease: insights from two us populations living a century apart. oral health prev dent 2008; 6:23-8. 9. varenne b, petersen pe, ouattara s. oral health status of children and adults in urban and rural areas of burkina faso, africa. int dent j 2004; 54: 83–9 10. hessari h, miira m, mohammad j, samadzadeh h, heikki t. oral health and treatment needs among 18-year-old iranians. department of oral public health, institute of dentistry university of helsinki (finland ). med princ pract 2008; 17: 302–307. 11. salman f. dental caries prevalence among intermediate and secondary school students in thamar– yemen. al–rafidain dent j 2008; 8(1): 83-9. 12. garg n, garg a. textbook of preventive dentistry. 2nd ed. new delhi: yaypee borthers medical publishers; 2013. 13. ditmyer m, dounis g, mobley c, schwarz e. inequalities of caries experience in nevada youth expressed by dmft index vs. (sic) over time. bmc oral health 2011; 11: 12. 14. balan d, pasareanu m, savin c, balcos c, zetu i. socioeconomic status and oral health behavior – possible dental caries risk factors in school communities.international j med dentistry 2013; 3: 32. caries – experience descriptive statistics kruskal wallis test age in years mean ±se median mr # chi-square p-value ds 16 2.86 0.189 2.00 410.90 14.419 0.001** 17 3.38 0.204 3.00 443.69 18 4.15 0.225 3.00 489.19 total 3.51 0.122 3.00 ms 16 0.85 0.139 0.00 452.29 0.116 0.944 17 0.86 0.150 0.00 448.01 18 0.92 0.142 0.00 451.19 total 0.88 0.083 0.00 fs 16 0.60 0.107 0.00 449.03 1.265 0.531 17 0.50 0.087 0.00 443.12 18 0.55 0.087 0.00 458.12 total 0.55 0.054 0.00 dmfs 16 4.31 0.284 3.00 410.38 13.476 0.001** 17 4.74 0.262 4.00 446.51 18 5.62 0.281 4.00 487.12 total 4.94 0.161 4.00 j bagh college dentistry vol. 28(4), december 2016 assessment of pedodontics, orthodontics and preventive dentistry 162 assessment of enamel surface after debonding of different types of esthetic brackets (an in vitro study) ghaith m. hasan, b.d.s. (a) dhiaa j. n. al-dabagh, b.d.s., m.sc. (b) abstract background: debonding orthodontic brackets and removal of residual bonding material from the enamel surface include critical steps that may cause enamel damage. the aim of the present study was to evaluate and compare the site of bond failure and enamel surface damage after debonding of three types of esthetic brackets (composite, ceramic, sapphire) bonded with light cure composite and resin-modified glass ionomer adhesive. materials and methods: seventy two maxillary premolars teeth were divided into three groups each group consisted of 24 teeth according to the type of brackets. each group was subdivided into two subgroups (12 teeth for each) according to the bonding material that was used. after 7 days of bonding procedure, the brackets were debonded using specifically designed debonding device in which the brackets were debonded by a debonding pliers to simulate the actual clinical debonding procedure. instron universal testing was used to apply the debonding force on the debonding pliers which transferred to the bracket. the teeth and the brackets were examined with a 10x magnifying lens to evaluate the site of failure. after the removal of residual adhesive, stereomicroscope was used to evaluate enamel surface damage. results: the most common type of bond failure was cohesive failure (score ii) in all esthetic brackets. while enamel cracks (scale i) were found to be the most type of enamel damage. chisquare showed non-significant differences among different types of esthetic bracket bonded with same type of adhesive and between the same types of brackets (ceramic, sapphire) bonded with the two types of adhesive. on the other hand, there was significant difference between composite brackets subgroups bonded with the two adhesives. conclusion: the bond failure mostly within the adhesive itself and higher enamel damage was resulted from mechanical debonding of these esthetic brackets. key words: esthetic bracket, resin modified glass ionomer cement, bond failure, enamel damage. (j bagh coll dentistry 2016; 28(4):162-167) introduction the request for esthetic orthodontic appliances is growing and the advance of materials that present satisfactory esthetics for the patients and an acceptable clinical enactment for clinicians is looked-for (1). at the beginning of 1970s, plastic brackets were sold as the esthetical substitute to metal brackets. but they suffer from three largely unresolved problems: staining, poor dimensional stability and friction between bracket slot and metal arch wire (2,3). ceramic brackets which were first made available commercially in the late 1980. several ceramic brackets are available, all of which are composed of aluminum oxide. polycrystalline are made of fused aluminum oxide particles. single crystal sapphire is harder and has higher tensile strength than polycrystalline alumina (4,5). when the bracket is debonded, not only some adhesive remnants stay on the enamel surface, but (a)m.sc. student department of orthodontics, college of dentistry, university of baghdad. (b)professor department of orthodontics, college of dentistry, university of baghdad. enamel fracture can occur at the moment of debonding. this kind of enamel fracture causes plaque accumulation on the rough fractured surface and stain (6-8). clinically, reports of bracket fracture and enamel surface damage that occur during debonding of ceramic brackets continue to be a matter of concern to clinicians (9,10). the amount of enamel damage was related to the kind of bracket, bracket base design, and adhesive system used (11,12). most manufacturers now offer debonding pliers that has unique features engineered into the bracket to help in debonding. an alternative is to use thermal or laser instrument to weaken the adhesive to induce failure within the bonding agent itself (13). bonding agent is defined as a material that, when applied to surfaces of substances, can join them together, resist separation, and transmit loads across the bond. available bonding agents for orthodontic use include, in addition to the conventional auto curing composite resins, lightcuring composite resins and glass-ionomer cements, as well as hybrid materials comprising glassionomer and composite components (resin-modified glass-ionomers)(14). j bagh college dentistry vol. 28(4), december 2016 assessment of pedodontics, orthodontics and preventive dentistry 163 in the direct bonding technique, the material is cured under the brackets by transillumination because the structure of the teeth transmits visible light and by direct illumination from different sides (15). introduced resin-modified glass ionomer cements (rmgics) which set through a combination of acid–base reaction and photochemical polymerization (16). resin-modified refers to all cements in which the acid–base reaction of true glass-ionomer cements is supplemented by a polymerization reaction (17). in their simplest form, resin modified glass ionomer are glass ionomer cements with the addition of a few amount of a resin such as hydroxyethyl methacrylate (hema) or bis – gma in the liquid as a co-solvent (18,19). there was no any iraqi study regarding debonding of esthetic bracket to assess adhesive remnant index with subsequent evaluation of enamel damage that may occur specially after bonding with a new adhesive material (light cure resin modified glass ionomer capsule), so it is intended to implement the current study to establish baseline data regarding that. materials and methods seventy two maxillary premolars were selected for this study after examination with 10xmagnifying lens and transillumination light to be grossly intact, with no enamel cracks, caries, restorations, or surface irregularities, and without any pretreatment with chemical agents such as hydrogen peroxide (20-22). three types of roth orthodontic esthetic brackets were used in this study: composite bracket with bonding base has three dove tail grooves and the surface area of the bracket base is 16.95 mm2 ceramic brackets with bonding base has three dove tail grooves and the surface area of the bracket base is 16.95 mm2 sapphire brackets with bonding base is coated with zirconia powder creating millions of undercuts that mechanically lock with the bracket adhesive and the surface area of the bracket base is 13.862mm2,as provided by the company (ortho technology company, usa). after extraction, the teeth were washed and stored in normal saline containing crystals of thymol in closed container at room temperature (27º c ± 3), and that was change weekly to prevent dehydration and bacterial growth until preparation and testing(23). the samples were divided into three groups each group consist of 24 teeth according to the type of brackets that were used (composite, ceramic, sapphire), then each group was subdivided according to the bonding material into: 12 teeth which were bonded by gc fuji ortho lc capsule (gc japan)and took the color code (r, red) and12teeth which were bonded by light cure composite (orthotechnology, u.s.a) and took the color code (b, blue). retentive wedge shaped cuts were made along the sides of the roots of each tooth to increase the retention of the teeth inside the self-cured acrylic blocks (24,25). the glass slide placed on the table, each tooth was fixed in marked position on a glass slide in a vertical position using soft sticky wax at the apex of the root so that the middle third of the buccal surface was oriented to be parallel to the analyzing rod of the surveyor. this kept the buccal surface of tooth parallel to the applied force during the debonding test(26).two other teeth were fixed following the above mentioned procedure with 2cm apart between them on the same glass slab. the occlusal surfaces of the three teeth were oriented to same height by cutting from the root apices using a stone disc bur. the l-shaped metal plates, were painted with a thin layer of separating medium (vaseline) and placed opposite to each other in such way to form a box around the vertically positioned teeth with the crowns protruding. powder and liquid of the cold cured acrylic were mixed and poured around the teeth to the level of the cemento-enamel junction of each tooth (27).after setting the cold cured acrylic resin, the l-shaped metal plates and the sticky wax used for fixation of teeth in the proper orientation was removed, simple adjustment of the acrylic blocks was done using the portable engine to adjust the acrylic. after mounting, the buccal surface of each tooth was polished for 10 seconds. two types of etchant agent were used in bonding procedure, the first one was phosphoric acid gel (pulpdent co., u.s.a) used with composite light cure adhesive this was done for 30 seconds with a disposable brush for each tooth, according to the manufacturer instructions. then it was sprayed with water for 30 seconds and dried with air spray for 10 seconds to give the chalky white color appearance (28). the second one was polyacrylic acid conditioner (sdi co., australia) used with resin modified glass ionomer cement according to the manufacturer instructions then rinse thoroughly. j bagh college dentistry vol. 28(4), december 2016 assessment of pedodontics, orthodontics and preventive dentistry 164 after that each bracket was positioned in the middle third of the buccal surface and parallel to the long axis of the tooth, and then pushed firmly toward the tooth surface using a clamping tweezers and bracket positioner. a constant load 200 gm was placed on the bracket for 10 seconds to ensure that each bracket was placed under an equal force and to ensure a uniform thickness of the adhesive (29). the same procedure done for the light cure composite adhesive system except that fuji ortho lc capsule was mixed according to the manufacturer instructions and apply to the moist teeth (water used for moisturing applied with disposable brush). after completion of the bonding procedure the specimens were put in a medium containing normal saline with thymol at 37°c for 7 days (30). debonding done byan apparatus especially designed to get the gingivo-occlusal directed force to simulate the normal clinical application of the debonding procedure with crosshead speedof0.5mm/minute (31). each debonded bracket was kept in a labeled container until the time of examining the adhesive remnant index (ari). the debonded brackets and the enamel surface of each tooth were inspected under10x magnifying lens to assess the amount of adhesive remaining on the tooth surface and the site of bond failure (32).the enamel surface was scored according to wang et al. classification(33) as following: score 1: failure between bracket base and adhesive. score 2: cohesive failure within the adhesive itself. score 3: adhesive failure between adhesive and enamel. score 4: enamel detachment. after that, the residual adhesive was removed with a 12-bladed tungsten carbide finishing bur (komet dental, germany).the enamel surface was evaluated by using stereomicroscope. photograph of post treated enamel surface took at 40x magnification then the image transferred to computer. analysis and assignment scale to each photo, was done according to following scale (30): (0): enamel surface free from cracks or tear –out (1): enamel surface with cracks (2): enamel surface with tear-outs (3): enamel surface with cracks and tear-outs. statistical analyses data will be collected and analyzed by using spss (statistical package of social science) software version 20 for windows xp chicago, usa. in this study the following statistics were used: descriptive statistics: 1. frequency. 2. percentage. 3. statistical tables. inferential statistics: 1. chi-square: to test any statistically significant differences among groups and subgroups for the failure site examination results and for enamel surface damage. for the purpose of statistical analysis, the ari scores 1and 2, as well as 3 and 4, were combined. 2. yate's correction test used with 2*2tableand likelihood ratio used with more than 2*2 table as alternative to chi-square when the expected value less than 5 in 20% of cells or in any cell. the probability value was set as: p>0.05 ns non-significant 0.05≥p>0.01 s significant p≤0.01 hs highly significant. results adhesive remnant index brackets bonded with light cure composite score ii was the predominant criteria of bond failure (83.3%). which was higher in composite brackets (91.7%) followed by sapphire brackets (83.3%) and the least was in ceramic brackets (75%)as shown in (table.1).non-significant differences were found among esthetic brackets. table 1: frequency and percentage of adhesive remnant criteria of the three types of esthetic brackets bonded with light cure composite. score s bracket types cerami c composi te sapphir e tota l i no . 2 1 1 4 % 16.7 8.3 8.3 11.1 ii no . 9 11 10 30 % 75 91.7 83.3 83.3 iii no . 1 0 0 1 % 8.3 0 0 2.8 iv no . 0 0 1 1 % 0 0 8.3 2.8 total no . 12 12 12 36 % 100 100 100 100 j bagh college dentistry vol. 28(4), december 2016 assessment of pedodontics, orthodontics and preventive dentistry 165 brackets bonded with light cure resinmodified glass ionomer: score ii was the predominant criteria of bond failure (69.4) which was higher in ceramic brackets (83.3%) followed by sapphire brackets (66.7%) and the least was in composite brackets (58.3%). as shown in (table.2).non-significant differences were found among esthetic brackets. table 2: frequency and percentage of adhesive remnant criteria of the three types of esthetic brackets bonded with light cure resin modified glass ionomer scores bracket types ceramic composite sapphire total i no. 1 0 3 4 % 8.3 0 25 11.1 ii no. 10 7 8 25 % 83.3 58.3 66.7 69.4 iii no. 0 4 1 5 % 0 33.3 8.3 13.9 iv no. 1 1 0 2 % 8.3 8.3 0 5.6 total no. 12 12 12 36 % =100 100 100 100 evaluation of enamel surface brackets bonded with light cure composite: scale i was the predominant (55.6), which was higher in ceramic (58.3%) and in composite brackets (58.3%) and the least was in sapphire brackets (50%) as shown in (table.3).nonsignificant differences were found among esthetic brackets. table 3: frequency and percentage of enamel surface damage criteria of the three types of esthetic brackets bonded with light cure composite scale bracket types ceramic composite sapphire total 0 no. 5 5 5 15 % 41.7 41.7 41.7 41.7 i no. 7 7 6 20 % 58.3 58.3 50 55.6 ii no. 0 0 0 0 % 0 0 0 0 iii no. 0 0 1 1 % 0 0 8.3 2.8 total no. 12 12 12 36 % 100 100 100 100 brackets bonded with light cure resin modified glass ionomer: scale i was the predominant (55.6), which was higher in composite (58.3%) and in sapphire brackets groups (58.3%) and the least was in ceramic brackets (50%) as shown in (table.4). non-significant differences were found among esthetic brackets. table 4: frequency and percentage of enamel surface damage criteria of the three types of esthetic brackets bonded with resin modified glass ionomer scale bracket types ceramic composite sapphire total 0 no. 5 4 5 14 % 41.7 33.3 41.7 38.9 i no. 6 7 7 20 % 50 58.3 58.3 55.6 ii no. 1 1 0 2 % 8.3 8.3 0 5.6 iii no. 0 0 0 0 % 0 0 0 0 total no. 12 12 12 36 % 100 100 100 100 discussion adhesive remnant index: score ii was the predominant site of bond failure in composite and ceramic brackets. this might be due to the type of retention means present in the base of these brackets which are dovetail with horizontal and vertical grooves allowing easy penetration of the adhesive between them into the undercut areas with good air evacuation from peripheries preventing air entrapment, therefore better mechanical inter-lock could be obtained and the retention of the adhesive to the etched-enamel in brackets bonded with light cure composite and the use of enamel conditioner in bracket bonded with light cure resin modified glass ionomer cement lead to create thick and deep resin tags, in addition to that the presence of chemical bond between the resin modified glass ionomer cement and the enamel structure this came in agreement with alibrahim (34), so higher mechanical retention was obtained between adhesive and enamel surface than within the adhesive itself this agreed with the finding of maijer and smith(35). regarding sapphire brackets cohesive failure (score ii) that occurred might be due to the presence of zirconia particles coating the bracket base leading j bagh college dentistry vol. 28(4), december 2016 assessment of pedodontics, orthodontics and preventive dentistry 166 to the creation of millions undercuts that secure the bracket in its place, so increasing the adhesive – brackets retention to the level that prevent complete detachment of adhesive from the brackets base came in agreement with garma et al (36), and the retention of the adhesive to the etched-enamel in bracket bonded with light cure composite and to the conditioning enamel in bracket bonded with resin modified glass ionomer cement is greater than that within the adhesive itself. evaluation of enamel surface: regarding light cure composite: scale i (enamel cracks) appeared mostly, this might be due to the retention of the adhesive to the etched-enamel (thick and deep resin tags) and strong bond between bracket base and adhesive, so highest value of shear bond strength applied to bonded bracket was required during debonding. light cure resin modified glass ionomer capsule: scale i was the predominant type of enamel damage this might be due to the use of enamel conditioner (poly-acrylic acid) produce deep penetration of resin modified glass ionomer cement tags inside the enamel, therefore better mechanical retention between adhesive and enamel surface will be resulted and the presence of chemical bond between the adhesive and the enamel structure (chemical retention), so this type of failure associated with highest value of strength applied to bonded bracket. the conclusions that could be obtained from this study were: 1. ari showed statistically non-significant differences among different types of esthetic bracket (composite, ceramic, sapphire) bonded with same type of adhesive. 2. score ii (cohesive failure) was the most predominant type of ari of all tested esthetic brackets which indicate the most failure site occur usually within adhesive itself. 3. regarding enamel damage in all the tested esthetic brackets, there were non-significant differences among the different types of esthetic brackets with same type of adhesive and among the same types of brackets with different adhesive. 4. higher enamel damage specially scale i (enamel surface with cracks) result from mechanical debonding of the tested esthetic bracket (composite, ceramic, sapphire) with the two types of the adhesive (light cure composite, light cure resin modified glass ionomer capsule) that used. references 1. elayyan f, silikas n, bearn d. mechanical properties of coated superelastic archwires in conventional and selfligating orthodontic brackets. am j orthod dentofacial orthop 2010; 137(2): 213–7. 2. bishara se, trulove ts. comparisons of different debonding techniques for ceramic brackets: an in vitro study part 1. am j orthod dentofacial orthop 1990; 98(3): 263-73. 3. hershey h. the orthodontic appliance: esthetic consideration. j am dent assoc 1987; 115: 29e–34e. 4. swartz ml. ceramic bracket. j clin orthod 1988; 22: 82-8. 5. scott ga. ceramic brackets. j clin orthod1987; 21: 872. 6. sorel o, el alam r, chagneau f, cathelineau g. comparison of bond strength between simple foil mesh and laser structured base retention brackets. am j orthod dentofacial orthop 2002; 122: 260–6. 7. sorel o, el alam r, chagneau f, cathelineau g. changes in the enamel after in vitro debonding of brackets bonded with a modified glass ionomer cement. orthod fr 2000; 71: 155–3. 8. meng cl, li ch, wang wn. bond strength with apf applied after acid etching. am j orthod dentofacial orthop 1998; 114: 510-3. 9. harris a, joseph v, rossouw p. shear peel bond strengths of esthetic orthodontic brackets. am j orthod dentofacial orthop 1992; 102: 215–2. 10. birnie d. orthodontic materials update: ceramic brackets.br j orthod 1990; 17: 71–5. 11. liu jk, chung ch, chang cy, shieh db. bond strength and debonding characteristics of a new ceramic bracket. am j orthod dentofacial orthop 2005; 128(6): 761-5. 12. mundstock ks, sadowsky pl, lacefield w. an in vitro evaluation of a metal reinforced orthodontic ceramic bracket. am j orthod dentofacial orthop 1999; 116: 635-1. 13. proffit wr, fields hw, sarver dm.contemporary orthodontics. 5th ed. mosby inc. an affiliate of elsevier inc; 2013. p. 370-2. 14. dasalogiannakis j. glossary of orthodontic terms. berlin: quintessence books; 2000. 15. trimpeneers lm, verbeeck rmh, dermaut lr, moors mg. comparative shear bond strength of some orthodontic bonding resins to enamel. eur j orthod 1996; 18: 89–95. 16. antonucci jm, mckinney je, stansbury jw. resinmodified glass ionomer cement. us patent application.7–160856, 1988. 17. hegarty dj, macfarlane tv. in vivo bracket retention comparison of a resin-modified glass ionomer cement and a resin-based bracket adhesive system after a year. am j orthod dentofac orthop 2002; 121(5): 496-1. 18. albers hf. tooth-colored restoratives: principles and techniques. 9th ed. hamilton, london: bc decker inc 20 hughson st. south; 2002. 19. croll tp, nicholson jw. glass ionomer cement in pediatric dentistry: review of literature. pediatr dent 2002; 24(5): 4239. 20. d'attilio m, traini t, dilorio d, varavara g, festa f, tecco s. shear bond strength, bond failure, and scanning j bagh college dentistry vol. 28(4), december 2016 assessment of pedodontics, orthodontics and preventive dentistry 167 electron microscopy analysis of a new flowable composite for orthodontic use. angle orthod 2005; 75: 410-5. 21. attar n, taner tu, tűlűmen e, korkmaz y. shear bond strength of orthodontic brackets bonded using conventional vs. one and two step self-etching/adhesive system. angle orthod 2007; 77(3): 518-23. 22. bishara se, ostby aw, laffon jf, warren jf. the effect of modifying the self-etchant bonding protocol on the shear bond strength of orthodontic brackets. angle orthod j 2007; 77(3): 504-8. 23. turka t, elekdag-turkb s, iscic d, cakmakc f, ozkalaycic n. saliva contamination effect on shear bond strength of self-etching primer with different debond times. angle orthod 2007; 77(5): 901-6. 24. niazi nad. recycling of mesh bracket stainless steel orthodontic brackets. a master thesis, department of pop, college of dentistry, university of baghdad, 1992. 25. alexander jc, viazis ad, nakajima h. bond strength and fracture modes of three orthodontic adhesives. j clin orthod 1993; 27: 207-9. 26. sfondrini mf. halogen versus high-intensity light-curing of uncoated and precoated brackets: a shear bond strength study. j orthod 2002; 29: 45-50. 27. rajagopal r, padmanabhan s, gnanamani j. a comparison of shear bond strength and debonding characteristics of conventional moisture-insensitive, and self-etching primers in vitro. angle orthod 2004; 74(2): 264-8. 28. bishara se, oonsombat c, solimann mm, warren jj, laffoon jf, ajlouni r. comparison of bonding time and shear bond strength between conventional and a new integrated bonding system. angle orthod 2005; 75(2): 237-2. 29. bishara se, ostby aw, laffoon jf, warren jj. enamel cracks and ceramic brackets failure during debonding in vitro. angle orthod 2008; 78(6): 1178-83. 30. kitahara-céia fm, mucha jn, santosc pa. assessment of enamel damage after removal of ceramic brackets. am j orthod dentofacial orthop 2008; 134: 548-55. 31. martina r, laino a, cacciafesta v, cantiello p. recycling effects on ceramic brackets: a dimensional, weight and shear bond strength analysis. eur j orthod 1997; 19: 629-36. 32. chung ch, friedman d, mante fk. shear bond strength of rebounded mechanically retentive ceramic brackets. am j orthod dentofac orthop 2002; 122: 282-7. 33. wang wn, meng cl, tarng th. bond strength: a comparison between chemical coated and mechanical interlock bases of ceramic and metal brackets. am j orthod dentofac orthop 1997; 11(4):374-81. 34. al-ibrahim aso. assessment of shear bond strength of a new resin modified glass ionomer cement using different types of brackets an in vitro study. a master thesis, department of pop, college of dentistry, university of mosul, 1999. 35. maijer r, smith dc. variables influencing the bond strength of metal orthodontic bracket bases. am j orthod 1981; 79(1): 20-34. 36. garma nmh, kadhum as, yassir ya. an in vitro evaluation of shear bond strength of chemical and lightcured bonding materials with stainless steel,ceramic, and sapphire brackets j bagh coll dentistry 2011; 23: 133-8. j bagh college dentistry vol. 28(4), december 2016 cell surface oral diagnosis 56 cell surface expression of 70 kda heat shock proteins and p21 in normal oral mucosa, oral epithelial dysplasia and squamous cell carcinoma (an immunohistochemical study) ali shafeeq neamah, b.d.s. (1) ahlam hameed majeed, b.d.s., m.sc. (2) abstract background: oral scc is a complex malignancy where environmental factors, viral infections and genetic alterations most likely interact, and thus give rise to the malignant condition. the hsp70 play a direct role in apoptosis inhibition by aligning the improve d integrity of a cell’s proteins with the improved chances of that particular cell’s survival.p21 gene produces p21 protein which is a potent cyclin -dependent kinase inhibitor that plays a significant role in carcinogenesis. the aims of the study were to evaluate and compare the immun-histochemical expression of the hsp70 and cell cycle protein p21in nom, oed, and oscc. correlate both marker expressions with each other. materials and methods: forty six formalin-fixed, paraffin embedded tissue blocks(10 cases of normal oral mucosa,16 cases of oral epithelial dysplasia, and 20 cases of oral squamous cell carcinoma) were included in this study, an immunohistochemical staining w as performed using antihsp70monoclonalantibody, and anti p21 monoclonal antibody. results: positive ihc expression ofhsp70 w as found in 2 cases (20%) of nom, 13 cases (81.3%) of oed and in 16 cases (85%) of oscc. positive ihc expression of p21 w as detected in nom in 2 cases (20%), while it w as found in 9 cases (56.2%) of oed, and in 14 cases (70%) of oscc .the difference betw een the expressions of both markers was statistically significant in nom, highly significant in oed, and oscc. conclusions: this study signify the important role of hsp70 and p21in oral carcinogenesis and in the evolution of the mucosa from normal to dysplastic to invasive carcinoma keywords: nom, oed, oscc, hsp70, p21. (j bagh coll dentistry 2016; 28(4):56-60) introduction oral carcinogenesis is a highly complex multifocal process that takes place when squamous epithelium is affected by several genetic alterations. the use of several molecular biological techniques to diagnose oral precancerous lesions and cancer may markedly improve the early detection of alterations that are invisible under the microscope. this would identify patients at a high risk of developing oral cancer (1). hsp70 regulates a wide range of proteinassociated activities and elevated levels of hsp70 protect cells from apoptotic death. in oscc, immune staining intensity for hsp70 is suggested to be related to the degree of tumor cell differentiation (2). cyclin-dependent kinase inhibitor, p21, the small 165 amino acid protein p21 (also known as p21waf1/cip1) mediates p53-dependent g1 growth arrest. earlier studies supported the view that p21 suppresses tumours by promoting cell cycle arrest in response to various stimuli. (1) m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. additionally, substantial evidence from biochemical and genetic studies indicates that p21 acts as a master effector of multiple tumour suppressor pathways for promoting antiproliferative activities that are independent of the classical p53 tumour suppressor pathway (3). the lack of a unique marker of oscc has long been a problem in the early detection of oscc. it would be necessary to discover more reliable and efficient markers to characterize the malignant transformation of oral epithelium (4). this study aimed to evaluate and compare the expression of hsp70 and p21 in normal oral mucosa, oral epithelial dysplasia, and oral squamous cell carcinoma, and to correlate both marker expressions with each other. materials and methods the study samples included 46formalin-fixed, paraffin embedded tissue blocks (10 nom, 16 oed, and 20 oscc) dated from (1973 till 2013), obtained from the archives of the department of oral and maxillofacial pathology/ college of dentistry/ university of baghdad; al-najaf medical city. sections of 4µm thickness were mounted on normal glass slides, stained with h and e and histopathologically re-evaluated. histological grading for oscc and oral epithelial j bagh college dentistry vol. 28(4), december 2016 cell surface oral diagnosis 57 dysplasia were recognized for each case according to who classification 2005 (5). fourother4µmthicksections for each case were cut and mounted on positively charged slides (fisher scientific and escho super frost plus, usa) for immunohistochemical staining with monoclonal antibody hsp70 using abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit (catalog no. ab80436, cambridge, uk), and monoclonal antibody p21 using rabbit antihuman p21 antibody (catalog no. a 181606) dako denmark immunohistochemical detection kit was used. hsp70 and p21 scoring system was according to parvis and faezah (6) and mustafa et al. (7) statistical analysis the study parameters were scored and considered as categorical data thus they presented as count and percentage, the relationship between categories was tested by chi-square test. mann-whitney u test was applied to assess the markers’ comparison in each group as well as to assess groups’ comparison in each marker. pearson correlation was applied to assess the linear association between hsp70 and p21. the level of significance was 0.05 (two-sided) in all statistical testing. the statistical analysis was performed using spss windows, version 19. results positive hsp70immunostaining was detected as brown cytoplasmic expression. (figures 1, 2and 3) ihc staining of hsp70 in nom reveals that8 cases (80%) showed negative expression, 2 cases (20%) showed positive score i expression. and in oed, 3 cases (18.8%) showed negative expression, 3 cases (18.8%) showed score i positive expression, 9 cases (65.2%) showed score ii positive expression, and 1 case (6.2%) showed score iii positive expression. while in oscc,ihc staining of hsp70 reveals that 3 cases (15.0%) showed negative expression, 2 cases(10%) showed score i positive expression, 13 cases(65%) showed score ii positive expression, and2cases (10%) showed score iii positive expression. positive p21 immunostaining was detected as brown (nuclear and cytoplasmic) expression. (figures 4, 5and 6) regardingp21 expression in nom, 8 cases (80%) showed negative expression and 2 cases (20%) showed positive expression. and in oed, 7cases (43.8%) showed negative expression, 4cases (25.0%) showed score i positive expression, and5 cases (31.2%) showed score ii positive expression. while in oscc, p21 immunostaining reveals that 6 cases (30%) showed negative expression, 8 cases (40%) showed score i positive expression, and 6 cases (30%) showed score ii positive expression. regarding markers’ (hsp70andp21 expression) comparison in each group and according to mann-whitney u test, the results revealed a statisticallya highly significant difference in nom (p-value= 0.004), oed and oscc (p=0.000), as clarified in table (1). regarding groups’ comparison in each marker, the results revealed statistically highly significant difference in hsp70 (p=0.001) and p21 (p-0.000) as clarified in table (2). figure 1: positive cytoplasmic expression of hsp70 in mild dysplasia (400x) figure 2: positive cytoplasmic expression of hsp70 in moderate dysplasia (400x) figure 3: positive cytoplasmic expression of hsp70 in well differentiated scc (200x). j bagh college dentistry vol. 28(4), december 2016 cell surface oral diagnosis 58 figure 4: positive nuclear and cytoplasmic expression of p21 in moderate dysplasia. (200x) figure 5: positive nuclear and cytoplasmic expression of p21 in well differentiated scc (400x). figure 6: positive nuclear and cytoplasmic expression of p21 in moderately differentiated scc. (400x) discussion assessment of hsp immunehistochemistry the results of the present study showed that positive immune staining of hsp70 was found in 20% of normal oral mucosa cases. this result agrees with seoane et al (8). according to nutan (9), the normal, nondiseased mucosa (free of any pathology/ source of irritation) of the oral cavity shows a faint expression of heat shock proteins in the epithelium. table 1: descriptive statistics and markers’ comparison in each group groups markers descriptive statistics comparison n mean s.d. s.e. mann-whitney u test p-value nom hsp70 10 7.6 8.74 2.8 -2.81 0.004 (hs) p21 10 1.34 1.93 0.61 oed hsp70 16 22.1 15.1 3.8 -5.97 0.000 (hs) p21 16 6.1 6.23 1.56 scc hsp70 20 31.5 16.7 3.7 -5.93 0.000 (hs) p21 20 6.68 6.52 1.46 table 2: descriptive statistics and groups’ comparison in each marker markers groups descriptive statistics comparison n mean s.d. s.e. mann-whitney u test p-value hsp nom 10 7.6 8.74 2.8 13.07 0.001 (hs) ed 16 22.1 15.1 3.8 scc 20 31.5 16.7 3.7 p21 nom 10 1.34 1.93 0.61 23.67 0.000 (hs) ed 16 6.1 6.23 1.56 scc 25 8.68 6.52 1.46 j bagh college dentistry vol. 28(4), december 2016 cell surface oral diagnosis 59 concerning oed cases the results of this study showed that positive expression of hsp70was observed in (81.8%) of oed cases. hsp positivity was found in (85%) of oscc cases. over expression of hsp70 in oral cells may reflect a state of biological stress experienced by premalignant and malignant cells. alternatively, high levels of hsp70 may be a requirement, or may be associated with a state of increased cellular activity or cell proliferation (8) sugerman et al. (10) studied (hsp70) expression in oscc, epithelial dysplasias and benign oral mucosal lesions by comparing their staining intensity. median staining intensity was significantly greater in scc, epithelial dysplasias and benign oral mucosal lesions compared to normal mucosa. however, staining intensity in poorly differentiated squamous cell carcinoma was greater than that in moderately differentiated scc, though no statistical significance was observed. assessment of p21 immuno histochemistry the present study showed positive p21 immuno-reactive in nom in (20%) of cases, and in oed it was found in (56.%). these results were in agreement with huang et al (11) that’s showed positive p21expression in nom and oed, according to clinic-pathological correlation of p21 and oed, the results of this study showed statistically non-significant correlation, which agrees with choi et al (12). p21 positivity was found in (70%) of oscc cases. agree with yuen et al (13). that showed higher p21 expression in the oscc group. in the dysplastic epithelium, p21 increases its expression as the degree of dysplasia increases. in oscc, expression is variable, especially in poorly differentiated tumor areas (14). it has been well documented that alterations of levels of p21 expression are early events in the development of dysplastic oral epithelial cells and lingual carcinoma (15). the present study showed statistically significant difference between hsp70 andp21 in nom, and highly significant difference between them in oed and oscc. correlation between hsp70 and p21 in each group this is the first study in iraq and other parts in the world assessing the correlation between hsp 70 and p21immunohistochemical expression in nom, oed, and oscc. since this is a pioneer research in assessing that correlation, so the comparison could be withdrawn from other studies using other tissue specimen, which is in agreement with malusecka et al (16) that showed there was significant correlation between hsp70 and p21 in lung cancer. the present study showed ahighly significant correlation in hsp70 and p21 regarding groups’ comparison. this means that hsp70 andp21 play a role in oral carcinogenesis. references 1. joseph bk. oral cancer: prevention and detection. medical principles and practice 2002; 11 (supplement 1): 32–5. 2. sreedhar as, csermely p. heat shock proteins in the regulation of apoptosis: new strategies in tumor therapy: a comprehensive review. pharmacol ther b. 2004; 101: 227–57. 3. morano ka. new tricks for an old dog: the evolving world of hsp70. ann ny acad sci 2007; 1113: 1–14. 4. chang bd, watanabe k, broude ev, et al. effects ofp21waf1/cip1/sdi1 on cellular gene expression: implications for carcinogenesis, senescence, and agerelated diseases. proc natl acad sci usa 2000; 97: 4291-6. 5. world health organization. tumours of the oral cavity and oropharynx. in: barnes l, eveson jw, reichart p, sidransky d, editors. pathology and genetics. head neck tumors. lyon: iarc press; 2005. p. 177-9. 6. parviz d, faezeh a. hsp27 and hsp70 expression in squamous cell carcinoma: an immunohistochemical study. dent res j (isfahan) 2012; 9(2): 162–6. 7. işın m, uysaler e, özgür e, köseoğlu h, şanlı ö , yücel ob, gezer u, dalay n. exosomal lncrna-p21 levels may help to distinguish prostate cancer from benign disease front genet 2015; 6: 168. 8. seoane j, ramírez jr, romero ma, varela-centelles p, garcia-pola mj. expression of heat shock protein (hsp70) in oral lichen planus and non-dysplastic oral leukoplakia. clinotolaryngol allied sci 2004; 29:191–6. 9. tyagi n, shetty dc, aadithya b. altered expression of hsp70 in oral lichen planus. j oral maxillofac pathol 2012; 16(2): pmc3424933. 10. jasbir k, ranju rr. differential expression of 70 kda heat shockprotein in human oral tumorigenesis. int j cancer 1995; 63: 774-9. 11. sugerman pb, savage nw, xu lj, walsh lj, seymourgj. et al. heat shock protein expression in oral epithelial dysplasia and squamous cell carcinoma. eur j cancer b oral oncol 1995; 31b(1): 63-7. 12. huang y1, wang w, chen y, huang y, zhang j, he s, tan y, qiang f, li a, røe od, wang s, zhou y, zhou j. the opposite prognostic significance of nuclear and cytoplasmic p21 expression in resectable gastric cancer patients. j gastroenterol 2014; 49(11):1441-52. 13. choi hr, tucker as, huang z, gillenwater am, luna ma, batsakis jg, el-naggar ak. differential expression of cyclin-dependent kinase inhibitors (p27 and p21waf/cip1) and their relation to p53 and ki-67 j bagh college dentistry vol. 28(4), december 2016 cell surface oral diagnosis 60 in oral squamous tumorigenesis. int j oncol 2003; 22: 409-14. 14. yuen po, chow v, choy j, lam ky, ho wk, wei wi. the clinicopathologic significance of p53 and p21 expression in the surgical management of lingual squamous cell carcinoma. anatomic pathol 2001; 17: 2615-20. 15. aaagarwal s, mathur m, shukla nk, ralhan r. expression of cyclin dependent kinase inhibitor p21waf1/cip1 in premalignant and malignant oral lesions: relationship with p53 status. oral oncol 1998; 34: 353–60. 16. malusecka e, krzyzowska-gruca s, gawrychowski j, fiszer-kierzkowska a, zofia stress proteins hsp27 and hsp70i predict survival in non-small cell lung carcinoma anticancer res 2008; 28: 501-6. 25. juman f.doc j bagh college dentistry vol. 25(1), march 2013 dental caries, orthodontics, pedodontics and preventive dentistry153 dental caries, mutans streptococci, lactobacilli and salivary status of type1 diabetic mellitus patients aged 1822 years in relation to glycated haemoglobin juman d. alkhayoun, b.d.s., h.d.d. (1) ban s. diab, b.d.s., m.sc., ph.d. (2) abstract background: diabetic mellitus is one of the serious systemic diseases that may cause general systemic changes, which may be reflected in the oral cavity. the aims of this study were to assess the severity of dental caries, mutans streptococci and lactobacilli in addition to flow rate and ph among uncontrolled and controlled diabetic groups in comparison with non-diabetic control group. materials and methods: study groups consisted of 25 uncontrolled diabetic patients (hba1c > 7), 25 controlled diabetic patients (hba1c ≤ 7), in addition to 25 non-diabetic healthy looking individuals. their age was (18-22) years from both genders. the diagnosis and recording of dental caries was according to severity of dental caries lesion through the application of d1_4mfs (manji et al, 1989) and stimulated salivary samples were collected. salivary flow rate and ph were estimated. viable count of mutans streptococci (on mitissalivarius bacitracin agar) and lactobacilli (on rogosa) was determined. results: the mean values of caries-severity were recorded to be highest among study groups compared to the control with statistically highly significant difference (p<0.01). lowest values of salivary ph and flow rate were among study groups compared to the control with highly significant difference (p<0.01). concerning mutans streptococci and lactobacilli were found that the mean values of them for uncontrolled diabetic group were highly significant higher than both mean values of controlled diabetic group and control group. conclusion: dental caries revealed higher percentage of occurrence and severity among uncontrolled diabetic group. furthermore there was significant influence of the diabetic and the poor metabolic control on the salivary flow rat, ph, mutans streptococci and lactobacilli that have an effect on caries occurrence and severity. keywords: diabetic mellitus, dental caries, glycated haemoglobin, mutans streptococci, lactobacilli. (j bagh coll dentistry 2013; 25(1):153-158). introduction diabetes is a chronic systemic disorder of glucose metabolism. the two main types of diabetes mellitus are type 1 or insulin-dependent diabetes mellitus (iddm) and type 2 or noninsulin-dependent diabetes mellitus (niddm) (1, 2). type 1 of diabetes account for 10 to 15 % of all cases of dm (3). glycated haemoglobin (glycosylate haemoglobin, hba1c) is a form of haemoglobin used to identify the average plasma glucose concentration over prolonged periods of time. it is formed in a non-enzymatic pathway by haemoglobin's normal exposure to high plasmas levels of glucose, the measurement of glycosylated haemoglobin is one of the well established means of monitoring glycemic control in patients with diabetes mellitus (4). oral manifestations associated with diabetes are in most cases restricted to the uncontrolled or poorly controlled patient. there is evidence that diabetic patients have saliva secretion different from non-diabetic subjects (5). however, the literatures contain contradictory results, mata et al. (6), siudikiene et al. (7) reported that both unstimulated (resting) and stimulated salivary flow rates are reduced in diabetic (1)m.sc student department of pedodontic and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontic and preventive dentistry, college of dentistry, university of baghdad. patients, whereas lopez et al. (8) reported that only unstimulated salivary flow is reduced. in contrast, swanljung et al. (9) and edblad et al. (10) did not find any significant differences in salivary flow rates between diabetic and non-diabetic individuals. in general, the higher the flow rate, the faster the clearance and the higher the buffer capacity (11). sakeenabi and hiremath (12) and gawri et al. (13) concluded that decrease salivary flow rate, salivary ph and increase the levels of both salivary mutans streptococci and lactobacilli significantly correlated with caries experience. studies on the concentration of streptococcus mutans and lactobacillus in the saliva of diabetics are inconclusive. wallengren et al. (14) demonstrated that the inheritance of some types of hla-dr4, most prevalent in type1 diabetics, was related to low salivary iga activity against the streptococcus mutans lead to increase the level of these bacteria. while other studies reporting decreased, increased or equivalent levels of the concentrations of these bacteria both in the saliva of diabetics and non-diabetics (7, 15). the present studies was conducted among patients with type1 diabetic mellitus aged 18-22 years in comparison to control group and determine the occurrence and severity of following variable: dental caries and its relation to physicochemical characteristic of stimulated saliva (salivary flow rate, ph). and j bagh college dentistry vol. 25(1), march 2013 dental caries, orthodontics, pedodontics and preventive dentistry154 evaluate the quantitative distribution of mutans streptococci and lactobacilli in saliva and their relation to oral variable. in addition examine the relation of glycated haemoglobin(hba1c) with dental caries, oral microorganisms and salivary variables (salivary flow rate, ph). materials and methods in the present investigation, the study group included 50 diabetic adults, with an age range of 18-22 years of both gender. they were examined at the diabetic and endocrinology center, alkindy teaching hospital in baghdad city during the period from the first of november 2011 till the end of april 2012. they were all with confirmed diagnosis of type iddm with minimum duration of diabetes of at least 5 years (5-10years). the samples were divided into two groups based on the hba1c(1): 25 uncontrolled type 1 diabetes mellitus (hba1c > 7) patients, 25 controlled type 1 diabetes mellitus (hba1c ≤ 7) patients and nondiabetic subjects as a control group were included 25healthy students of both gender from college of dentistry / university of baghdad who did not suffer from any systemic diseases with an age range of 18-22 years and monitored their capillary blood glucose closely prior to the study, and matching with the study group. caries experience was recorded according to the criteria manjie et al. (16) this allows recording decayed lesion by severity. saliva was collected for diabetic patients at the same day of blood sample aspiration for hba1c assessment by measuring the absorbance of the glycohemoglobin and of the total hemoglobin fraction at 415 nm in comparison with a standard glycohemoglobin preparation carried through the test procedure (humanbiochemical, 2011, germany). the collection of stimulated salivary samples was performed under standard condition according to tenovuo and lagerlöf (17). immediately after collection of saliva, through five minutes and disappearance of the salivary foam, the salivary flow rate was expressed as ml / mins and salivary ph was measured using a portable electronic ph meter. the salivary samples were then taken to the laboratory for microbiological analysis. saliva was homogenized by vortex mixer for two minutes. ten fold serial dilutions were prepared using normal saline, two dilutions were selected for each microbial type and inoculated on the mitissalivarius bacitracin agar (msb agar) (the selective media for mutans streptococci) (18) and rogosa selective lactobacilli agar (rsl) (19). identification of mutans streptococci and lactobacilli includes: colony morphology; gram’s stain according to koneman et al. (20); motility; catalase production (20). ctamannitol media had been used to test the ability of mutans streptococci to ferment the mannitol. (21). intra and inter calibration were performed to overcome any problem that could be faced during the research, and to ensure proper application of diagnostic criteria used in recording dental status through inter calibration. statistical analysis and processing of the data were carried out using spss version 18. descriptive statistics. the statistical tests that were used in anova test; l.s.d. test; student's t-test; pearson correlation coefficients and paired sample t-test. the level of significance was accepted at p< 0.05, and highly significance when p< 0.01. results the percentage of dental caries occurrence in the present study was 100% in diabetes mellitus patients, while in control group (non-diabetic subjects) was 88%. results revealed that caries experience represented by ds and dmfs were highly significant differ (p<0.01) among three groups (table 1). further investigation using l.s.d. test to ds revealed that both uncontrolled diabetic and controlled diabetic had highly significant higher ds than control group (m.d. 25.08 and -7.72 respectively p<0.01).furthermore the uncontrolled diabetic had highly significant higher mean value of ds than controlled diabetic group (m.d. -17.36 p<0.01). on the other hand, using l.s.d. test concerning dmfs, showed that uncontrolled diabetic had highly significant higher mean than both controlled diabetic group and control group (m.d. -19.60 and -25.80 respectively p<0.01).while data of present study showed the mean difference between controlled diabetic and control group was not significant (p>0.05 ). salivary flow rate and ph among study and control groups are shown in table 2. results revealed that salivary flow rate and ph were highly significant differ (f-value 160.03 and 183.94 respectively p<0.01) among three groups. further investigation using l.s.d. test concerning salivary flow rate revealed that the mean value in uncontrolled diabetic group was highly significant lower than mean values in both controlled diabetic group and control group (m.d. 0.36, 1.77 respectively p<0.01), and the mean value of salivary flow rate among controlled diabetic group was highly significant lower than salivary flow rate in control group (m.d. 1.41 p<0.01). the same picture was found concerning salivary ph the mean value among uncontrolled diabetic group was highly significant lower than mean values in both controlled diabetic and control groups (m.d. 1.22, 2.14 respectively p<0.01), as j bagh college dentistry vol. 25(1), march 2013 dental caries, orthodontics, pedodontics and preventive dentistry155 well as the mean value of salivary ph in controlled diabetic group was highly significant lower than mean value of salivary ph in control group (m.d. 0.91 p<0.01). the viable count (cfu/ml) of salivary mutans streptococci and lactobacilli were highly significant differ (f-value 24.74 and 124.947 respectively p<0.01) among three groups. table 3. the highest cfu/ml of salivary mutans streptococci and lactobacilli values were represented in the saliva of the uncontrolled diabetic group followed by the controlled diabetic group then the control group. table 4 showed the correlation coefficients of salivary flow rate with caries experience for study and control groups. analysis among uncontrolled diabetic group revealed that the relation between salivary flow rate and ds was significant in negative direction (r= -0.423 p<0.05). table 5 illustrates that the correlations were highly significant in negative direction between salivary ph and dmfs and ds (r=-0.655 and -0.663 respectively p<0.01). however among control group the relation between ph and dmfs was highly significant in negative direction (r = 0.820 p<0.01). table 6 revealed that among uncontrolled diabetic group the salivary mutans streptococci correlate positively with caries experience including dmfs, ds and these relations were highly significant for dmfs and ds (r = 0.741 and 0.838, respectively p< 0.01). a significant positive relations were also found among controlled diabetic group concerning ds and dmfs(r = 0.429, and 0.432 respectively p< 0.05). the same finding found concerning control group but the highly significant relation was found concerning ds and dmfs(r = 0.566 and 0.652 respectively p< 0.01). correlation coefficients of salivary lactobacilli in relation to dental caries are seen in table 7. this table revealed that among uncontrolled diabetic patient the salivary lactobacilli correlate positively with caries experience including dmfs, ds and these relations were highly significant for ds and dmfs (r = 0.777 and 0.718 respectively p< 0.01). among controlled diabetic group the salivary lactobacilli correlate positively with dmfs, ds and these relations were highly significant for ds and dmfs (r = 0.534, 0.524 respectively p<0.01) the same finding was reported among control group as the salivary lactobacilli correlate positively with caries experience and the correlation was significant concerning ds(r = 0.472 p<0.05). table 8 illustrates that among uncontrolled diabetic group the hba1c was positively correlated with caries experience represented by dmfs, ds and these relations were highly significant(r=0.586 and 0.574 respectively p<0.01). discussion researchers in the dental field have suggested that oral diseases (periodontal disease and dental caries) should be included among the complications of diabetes (22, 23). most evidently, not all diabetic patients are at equal risk for oral diseases, and more attention has recently been paid to possible diabetes-related risk factors to identify subjects who are more prone to dental caries. the study groups selected aged 18-22 years, as at these ages the type 1 diabetes mellitus are predominate. however, in the present study it was difficult to have relatives patients as a control group, so, most of individuals among control group were from the students of college of dentistry, this could partly explained the differences in the severity of caries among study groups and control group. since those students relatively differs from study subjects in their socioeconomic and behavior which play a role in the oral hygiene. data of the present study showed that caries experience represented by dmfs and ds components among uncontrolled diabetes group was higher than that with both control diabetes and non-diabetes control group. this result in agree with the results reported by(24, 25, 26). however, al-dahan, (1991) (27) reported an equal results of caries free subjects between control and diabetic groups. nonetheless, there is no consensus concerning the association between metabolic control and dental caries. in the current study positive highly significant correlation between hba1c and caries experience was found just among uncontrolled diabetes group. the elevation in the severity of dental caries among diabetic patients especially among uncontrolled diabetes group in the current study may be related to changes in the salivary physical properties involving the flow rate and salivary ph. a reduction in the flow rate of saliva and ph were reported among study groups. this may give an indication that the diabetes disease has an influence on salivary flow rate. these results are in agreement with reports of other researchers who found the same reduction in the salivary flow rate of diabetic patients (8, 6, 7, 28). it seems likely that the thirst and dry mouth characteristic among uncontrolled diabetes group are related to the poor metabolic control of disease with increased diuresis and fluid loss, and that salivary flow rate is restored when the disease is well controlled among controlled diabetic j bagh college dentistry vol. 25(1), march 2013 dental caries, orthodontics, pedodontics and preventive dentistry156 group. the possible explanation for the low salivation could be the neuoropathy of salivary gland(29). another explanation for the reduction of flow rate among the study groups especially uncontrolled diabetes group, is that the increase in glucose concentration in the blood may increase the osmolality of the glomerular filtrate and thus prevent the reabsorption of water as the filtrate passes down the renal tubular system. in this way the volume of urine is markedly increased in diabetes and polyuria and nocturia occur (30). the decreased in the salivary flow rate among diabetic patients could give some explanation to the increased severity of dental caries by the significant inverse relation with ds that were reported by the data of present study as well as in previous iraqi studies among diabetic (31, 32, 28). among uncontrolled diabetic group the salivary ph associated inversely with highly significant relation with ds and dmfs. this is consistent with other clinical studies that reported an inverse association between salivary ph and dental caries (33, 34). but disagree with other studies that reported no association with caries (35, 36). the streptococcus mutans the main microorganism responsible for the occurrence of dental caries in humans. due to its ability to adhere to tooth surface, the lactobacillus is more related to a later stage of caries development (37). therefore, one can suggest that diminished salivary flow create an attractive environment for establishment of mutans streptococci and lactobacilli in the oral cavity of diabetic patients especially among uncontrolled diabetes group. high levels of these bacteria in saliva can be considered a reasonable indicator of a cariogenic environment in the mouths of uncontrolled diabetes subjects, this is also shown by the data of present study that showed the severity of caries lesion was highly significant (or significant) correlated in positive direction with salivary mutans streptococci and lactobacilli in all groups. these results are in agreement with reports of other iraqi researcher who found the same positive correlation between caries lesion severity and both mutans streptococci and lactobacilli (38, 39, 40). in conclusion, dental professionals need to have comprehensive knowledge of their patients’ diabetes: knowledge that the patient has diabetes is not sufficient to assess the effects of diabetes with respect to oral diseases and dental treatment. this need is emphasized by the high and ever increasing number of patients with diabetes in iraq. on the other hand, the members of the team responsible for diabetes treatment should pay attention to dental care and guidance to dental treatment. finally, co-operation and consultation between all the members of the team responsible for the treatment of patients with diabetes is highly recommended. references 1. american diabetes association (ada). diagnosis and classification of diabetes mellitus. diabetes care 2007; 30:s42-s47. 2. guyton c, hall je. text book of medical physiology. 12th ed. elsevier saunders. philadelphia, 2012. 3. beers mh, porter rs, jones tv. the merck manual of diagnosis and therapies: endocrine and metabolic disorders .section 2.chapter13. merck research laboratories. glasgow. washington. 2006. 4. sultanpur cm, deepa k, kumar sv. comprehensive review on hba1c in diagnosis of diabetes mellitus. internat. pharmace scien rev& res 2010; 3(issue 2):119-124. 5. alemzadeh r, wyatt dt. diabetes mellitus. in: kliegman rm, behrman re, jensen hb, stanton bf (editors), nelson textbook of pediatrics. 17th ed. chapter 583. philadelphia: w.b. saunders.2003; pp: 1947-1972. 6. mata ad, marques d, rocha s, francisco h, santos c, mesquita mf. effects of diabetes mellitus on salivary secretion and its composition in the human. mol cell biochem 2004; 261: 137-142. 7. siudikiene j, machiulskiene v, nyvad b, tenovuo j, nedzelskiene i. dental caries and salivary status in children with type 1 diabetes mellitus, related to the metabolic control of the disease. eur j oral sci 2006; 114: 8-14. 8. lopez m, colloca m, paez r, schulimach j, koss m, chervonagura a. salivary characteristics of diabetic children. braz dent j 2003; 14(1): 26-31. 9. swanljung o, meurman jh, torkko h, sandholm l, kaprio e, maenpaa j. caries and saliva in 12-18-yearold diabetics and controls. scand j dent res 1992; 100: 310-313. 10. edblad e, lundin sa, sjodin b, aman j. caries and salivary status in young adults with type 1 diabetes. swed dent j 2001; 25: 53-60. 11. miura h, isogai e, hirose k, wakizaka h, ueda i, ito n. application of sucrose indicator strip to evaluate salivary sucrose clearance. j dent 1991; 19: 189-191. 12. sakeenabi b, hiremath ss. dental caries experience and salivary streptococcus mutans, lactobacilli scores, salivary flow rate and salivary buffering capacity among 6 year old indian school children. j clin exp dent 2011; 3(5):e412-7. 13. gawri s, shukla p, chandrakar a. micro flora present in dental caries and it’s relation to environmental factors. recent research in science and technology. 2012; 4(3): 09-12. 14. wallengren mll, hamberg k, ericson d, nordberg j. low salivary iga activity to cell--surface antigens of mutans streptococci related to hla -drb1*04. oral. microbiol. immunol. 2005; 20: 73 -81. 15. zaiter s, ferencz , tomazinho ph. evaluation of salivary microbiota of pediatric patients with and without mellitus type1 diabetes. rsbo. 2006; 3:24 27. 16. manji f, fejerkov o, baelum v. pattern of dental caries in an adult rural population. caries res 1989; 23:55-62. j bagh college dentistry vol. 25(1), march 2013 dental caries, orthodontics, pedodontics and preventive dentistry157 17. tenovuo j, lagerlöf f. saliva. in: textbook of clinical cardiology. thylstrup a and fejerskov o. 2nd ed. munksgaard, copenhagen. 1994, 17-43. 18. gold o.g; jordan h v; van haute j. a selective medium for streptococcus mutans. archs. oral biol 1973; 18: 1357-64. 19. brenner mj, krieg nr, staleyjt. berge's manual of systematic bacteriology 10th ed,williams and wilkins co., usa.2005. 20. koneman ew, schreeckenberge pc, allens sd, janda wm. diagnostic microbiology,4th ed, jb.lippincott co., usa, 1992. 21. brown af. benson's microbiological applications. laboratory manual in general microbiology 9th ed. mcgraw-hill. new york.usa, 2005. 22. lamster ib, lalla e. periodontal disease and diabetes mellitus: discussion, conclusions, and recommendations. ann periodontol 2001; 6:146-9. 23. bakhshandeh s, murtomaa h, vehkalahti mm, mofid r, suomalainen k. dental findings in diabetic adults. caries res 2008; 42(1):14-18. 24. el-samarrai s, sabri n, makki z. dental caries among young diabetic patients in baghdad-iraq. iraqi dent j 1997; 20: 14-23. 25. twetman s, petersson gh, bratthall d. caries risk assessment as a predictor of metabolic control in young type 1 diabetics. diabet. med 2005; 22: 312 -5. 26. iqbal s, kazmi f, asad s. dental caries and diabetes mellitus. pak oral& dent j 2011; 31(1):60-3. 27. al-dahan z. oral health status among iddm on population group of teenagers in baghdad-iraq. a master thesis, college of dentistry, university of baghdad, 1991. 28. al-rawi nf. salivary constituents in relation to oral health status among a group of (type 1) diabetic children. a ph.d. thesis. college of dentistry, university of baghdad, 2009. 29. moore pa, guggenheimer j, etzel kr. type 1 diabetes mellitus, xerostomia, and salivary flow rates. oral surg oral med oral pathol oral radiol endod. 2001; 92:281-291.17: 343-64. 30. siudikiene j, machiulskiene v, nyvad b. dental caries increments and related factors in children with type 1 diabetes mellitus. caries res 2008; 42: 354 -62. 31. al-sagri a. oral health status of iraqi diabetic patients' salivary and microbial analysis. a ph.d. thesis, college of dentistry, university of baghdad, 2005. 32. al-zaidi wh. oral immune proteins and salivary constituents in relation to oral health status among pregnant women. a ph.d. thesis, college of dentistry, university of baghdad, 2007. 33. al-mashhadani a. oral health status and salivary streptococcus mutans in relation to primary and permanent dentition. a m.sc. thesis, college of dentistry, university of baghdad, 1996. 34. el-samarrai sk. major and trace elements of permanent teeth and saliva among a group of adolescent in relation o dental caries, gingivitis and mutans streptococci. a ph.d. thesis. college of dentistry, university of baghdad, 2001. 35. kirstila v, tenovuo j, ruuskanen o, nikoskelainen j, irjala k, vilja p. salivary defense factors and oral health in patients with common variable immunodeficiency. j clin immun. 1994; 14: 229-36. 36. närhi to, kurki n, ainamo a. saliva, salivary microorganisms and oral health in the home-dwelling old elderly–a five year longitudinal study. j dent res 1999; 78(10):1640-6. 37. thanyasrisung p, komatsuzawa h, yoshimura g. automutanolysin disrupts clinical isolates of cariogenic streptococci in biofi lms and planktonic cells. oral microbiol. immunol 2009; 24: 451 -455. 38. al-mizraqchi a. the occurrence of lactobacillus in the mouth of children and it's response to chlorhexidine. m.sc. thesis, college of science, university of al-mustansiriya, iraq, 1992. 39. al-mizraqchi a. microbiological and biochemical studies on; adherence of mutans streptococci on the tooth surfaces. ph.d.thesis, university of almustansiriya, iraq, 1998. 40. al-hayali, am. isolation and purification of glucosyltransferase from mutans streptococci and its relation to dental caries, dental plaque and parameters of saliva ph.d. thesis, college of dentistry, university of baghdad 2002. table 1: caries experience dmfs and its component (ds, ms, fs) (mean and standard deviation) among study and control groups. caries exper-ience uncontrolled diabetic controlled diabetic control statistical analysis mean ±sd mean ±sd mean ±sd f-value p-value ds 31.44 16.95 14.08 7.59 6.36 6.73 31.69* 0.00 ms 2.00 4.33 1.20 2.61 0.60 2.19 1.21 0.30 fs 4.32 5.76 3.28 3.51 5.00 6.48 0.64 0.52 dmfs 37.76 16.83 18.16 9.57 11.96 8.61 30.27* 0.00 *(p<0.01) highly significant df=2 table 2: salivary flow rate (ml/min) and ph (mean and standard deviation) among study and control groups salivary variables uncontrolled diabetic controlled diabetic control statistical analysis mean ±sd mean ±sd mean ±sd f-value p-value flow rate 0.84 0.19 1.20 0.31 2.61 0.52 160.03* 0.00 ph 6.08 0.34 7.31 0.36 8.22 0.46 183.94* 0.00 * (p<0.01) highly significant df=2 j bagh college dentistry vol. 25(1), march 2013 dental caries, orthodontics, pedodontics and preventive dentistry158 table 3: colony forming units (cfu/ml) of salivary mutans streptococci and lactobacilli (mean and standard deviation ×105) among study and control groups salivary flora uncontrolled diabetic controlled diabetic control statistical analysis mean ±sd mean ±sd mean ±sd f-value p-value mutans streptococci 397.04 133.66 232.64 101.87 185.00 96.23 24.74* 0.00 lactobacilli 22.51 7.96 2.23 1.86 2.06 4.00 124.94* 0.00 * (p<0.01) highly significant df=2 table 4: correlation coefficients between salivary flow rate and caries experience among study and control groups caries experience uncontrolled diabetic controlled diabetic control group flow rate flow rate flow rate r p r p r p ds -0.423* 0.03 -0.251 0.22 -0.087 0.68 dmfs -0.360 0.07 -0.216 0.30 -0.225 0.28 *(p<0.05) significant table 5: correlations coefficients between salivary ph and caries experience among study and control groups caries experience uncontrolled diabetic controlled diabetic control group ph ph ph r p r p r p ds -0.663* 0.00 -0.092 0.66 -0.283 0.17 dmfs -0.655* 0.00 -0.081 0.69 -0.820* 0.00 * (p<0.01) highly significant table 6: correlations coefficients between salivary mutans streptococci and caries experience among study and control groups caries experience uncontrolled diabetic controlled diabetic control group mutans streptococci mutans streptococci mutans streptococci r p r p r p ds 0.838** 0.000 0.429* 0.03 0.566** 0.003 dmfs 0.741** 0.000 0.432* 0.03 0.652** 0.000 *(p<0.05) significant ** (p<0.01) highly significant table 7: correlations coefficients between salivary lactobacilli and caries experience among study and control groups. caries experience uncontrolled diabetic controlled diabetic control group lactobacilli lactobacilli lactobacilli r p r p r p ds 0.777** 0.000 0.534** 0.006 0.472* 0.017 dmfs 0.718** 0.000 0.524** 0.007 0.318 0.12 *(p<0.05) significant ** (p<0.01) highly significant table 8: correlation coefficients between hba1c and caries experience among uncontrolled and controlled diabetic groups caries experience uncontrolled diabetic controlled diabetic hba1c hba1c r p r p ds 0.574** 0.003 0.214 0.30 dmfs 0.586** 0.002 0.195 0.34 *(p<0.05) significant ** (p<0.01) highly significant 18. saba f.doc j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 115 antibacterial effect of aqueous and alcoholic propolis extracts on aggregatibacter actinomycetemcomitans in patients with chronic periodontitis (an in-vitro study) saba s. mahdi, b.d.s. (1) liqaa’ m. ibrahim, b.d.s., m.sc. (2) wifaq m. ali, m.b.ch.b., f.i.c.m.s. (3) abstract background: propolis has received great interest because of its wide range antimicrobial activity. propolis also called (bee glue) due to its collection by (apismellifera) honeybees from various plants resinous substance. the aim of this study was to determine the antibacterial effect of propolis extracts (aqueous and alcoholic) on anaerobic periodontal pathogen namely aggregatibacteractinomycetemcomitans. materials and methods: strains of aggregatibacter actinomycetemcomitans wasisolated from pockets of systemically healthy patients aged between 35-55 years old suffering from chronic periodontitis with pocket depths of 5-6 mm, the bacteria cultured on special blood agar plates solid media. propolis was extracted by using water and alcohol. agar well technique was used to study the sensitivity of aggregatibacter actinomycetemcomitans to different concentrations of propolis extracts (70, 80, 90, 100, 125 and 150) mg/ml and other control agents (distilled water and chlorhexidine 0.2%). results: aggregatibacter actinomycetemcomitans was sensitive to propolis extracts; alcoholic extract was more effective than aqueous extract.all concentrations of propolis extracts showed smaller inhibition zones than 0,2% chx except 150 mg/ml concentration of aqueous extract ,(100, 125 and 150)mg/ml concentrations of alcoholic extract showed larger inhibition zones than 0,2% chx. conclusion: propolis extracts were effective against anaerobic periodontal pathogens (aggregatibacter actinomycetemcomitans). key words: propolis, antibacterial activity, anaerobic periodontal pathogen. (j bagh coll dentistry 2015; 27(4):115118). introduction periodontal disease is an infectious condition started as microbial plaque accumulates at the gingival margin of the tooth surface and provokes an inflammatory reaction (1). although the inflammatory process protects the host; it may lead to tissue destruction (2). porphyromonasgingivalis, treponemadenticola, tanerellaforsythensis, actinobacillusactinomycetemcomitans (a.a), fusobacteriumnucleatum, eikenellacorrodens are considered to be associated with chronic periodontitis (3). during the last two decades, it has been shown that aggrecatibacter actinomycetemcomitans can be regarded as a major pathogen in destructive periodontal diseases 4), it was also found that a.a is associated with systemic diseases (5). several studies suggested that the outcome of periodontal treatment is better if particular pathogens especially aggrecatibacter actinomycetemcomitans can no longer be detected after therapy (6). clinical treatment of periodontal diseases is initiated by controlling the accumulation of dental plaque associated with scaling-root planing that allows the elimination of biofilm and calculus. (1) m.sc. student. department of periodontics, college of dentistry, university of baghdad. (2) professor. department of periodontics, college of dentistry, university of baghdad. (3) assist. prof. unite of infectious and systemic diseases. college of medicine, university of baghdad. however, sometimes this treatment is not enough to control the severity of the disease, needing the antibiotic use. development of effective strategies for treatment of chronic periodontitis has posed a challenge, considering the increase in opportunistic bacterial infections. some of the drugs used in the treatment of periodontitis, are limited because of the high rate of allergy, resistance of periodontopathic bacteria and elevated cost. thus, searching for alternative antibacterial compounds has been a major concern in recent years (7,8). herbs are being widely explored to discover alternatives to synthetic antibacterial agents (9). propolis is a resinous complex material formed by bees from bee’s (wax, secretions) and plant exudates(10). propolis is responsible of honeycombs safety against microorganisms (11). honeybee’s propolis has wide range of biological actions including: (antimicrobial, antitumor, antiinflammatory, antioxidative, and hepatoprotective activities) which attracted researcher’s attention (12). it is composed of 5% pollen 50% vegetable balsam and resin, 30% wax, 10% essential and aromatic oils and 5% other components like organic remnants, but this composition vary according to the vegetal source (13). the aim of the present study was to determine the antibacterial effect of propolis extracts (aqueous and alcoholic) on anaerobic periodontal pathogen namely aggregatibacteractinomycetemcomitans. j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 116 materials and methods patient selection and sampling: fifteen systemically healthy patients of age range between 35-55 years old participated in this study; they had chronic periodontitis with at least four pockets of 5-6mm depth. a sample of plaque from subgingival periodontal pocket was excavated by gracey curette without touching adjacent tissue.plaque sample was spread on colombia blood agar solid media supplied with selective materials in the plates then plates were transported into an anaerobic jar with anaerobic gas pack incubated anaerobically for 72 hours. after incubation, bacterial identification was based on (the microscopic appearance and colonial shape and size, gram stain, biochemical tests like catalase, hemolytic capability, urease test, and antibiotic susceptibility tests). colonies were subcultured again on the same media anaerobically for 72 hours under the same condition, using the same method, to obtain pure cultures of aggregatibacter actinomycetemcomitans for detection of inhibition zone. extraction procedures to obtain propolis extracts: 1aqueous extract: 1000 ml of distilled water were added to100 grams of propolis in a dark glass which was left at room temperature for one to two weeks with shaking two to three times daily with shaker, then filtration was done first using gauze to get rid of the large particles, then the resultant liquid was filtered using a sterile whitman filter paper no1. the filtered extract was concentrated under vacuum 45ºc using a rota evaporator for five hours). then put in clean and dark container in warm place until use (14). 2-alcoholic extract: the preparation was done by the same procedure of aqueous extract except we use (96% ethanol alcohol) instead of distilled water (14). sensitivity of a.a to different concentrations of alcoholic and aqueous propolis extracts in vitro: the concentrations of alcoholic propolis extract used in this experiment were: (70, 80, 90, 100, 125, and 150) mg/ml. the concentrations of aqueous propolis extract used in this experiment were: (70, 80, 90, 100%, 125, and 150) mg/ml. chx gluconate (0.2%) and d.w (distilled water) were used in this experiment as a positive control and negative control respectively. agar well diffusion method was used, using a sterile loop, three colonies were picked up and spread on blood agar plate in a mattress fashion, then wells of equal size and depth will be prepared in the agar, afterwards each well was filled with the selected agent (100 microliter) then the plates were incubated anaerobically for 48 hours. the inhibition zones were measured in millimeters using a ruler. results the mean values and standard deviation (sd) with the maximum (max) and minimum (min) values of the inhibition zones in millimeters (mm) of the alcoholic propolis extract against aggregatibacter actinomycetemcomitans (a.a) are presented in table (1).alcoholic extract showed increase in the diameter of the inhibition zone as the concentration increased, 125 mg/ml concentration and chlorhexidine show approximately the same results (mean of inhibition zone for 125mg/ml concentration was 14.6 mm and the for chlorhexidine was 14 mm).150 mg/ml concentration showed larger inhibition zones than chlorhexidine (positive control); while distilled water (negative control) showed no inhibition zone. the mean values and standard deviation (sd) with the maximum (max) and minimum (min) values of the inhibition zones in millimeters (mm) of the aqueous propolis extract against aggregatibacteractinomycetemcomitans (a.a) are presented in table (2). aqueous extract showed increase in the diameter of the inhibition zone as the concentration increased, 125 mg/ml concentration and chlorhexidine show approximately the same results (mean of inhibition zone for 125 mg/ml concentration was14.3 mm and for chlorhexidine was 14.1mm) .150 mg/ml concentration showed larger inhibition zones than chlorhexidine (positive control); while distilled water (negative control) showed no inhibition zone. by using t-test, the differences between alcoholic and aqueous extract for all concentrations were: highly significant difference in 70 mg/ml and 80 mg/ml concentration, no significant difference in (90, 100 and 125) mg/ml concentrations and significant difference in 150 mg/ml concentration. as shown in table (3). the means of inhibition zones of all concentrations of alcoholic and aqueous extracts are presented in figure (1) it clearly shows that alcoholic extract showed higher inhibition zones than aqueous extract in all concentrations. j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 117 table (1): the inhibition zone (mm.) of aa bacteria using different concentrations of alcoholic propolis extract and +ve and –ve control. inhibition zone with alcoholic extract of propolis with +ve and –ve control mean s.d. min. max. 70 mg/ml 10.45 0.50 10 11 80 mg/ml 11.2 0.48 10.5 12 90 mg/ml 12.4 0.52 12 13 100 mg/ml 13.4 0.52 13 14 125 mg/ml 14.6 0.52 14 15 150 mg/ml 16.2 0.79 15 17 chx 14 0.67 13 15 d.w. 0 0 0 0 table (2): the inhibition zone (mm.) of aa bacteria using different concentrations of aqueous propolis extract and +ve and –ve control. inhibition zone with aqueous extract of propolis with +ve and –ve control mean s.d. min. max. 70 mg/ml 8.6 0.57 8 9.5 80 mg/ml 10.3 0.67 9 11 90 mg/ml 12 0.47 11 13 100 mg/ml 13.2 0.63 12 14 125 mg/ml 14.3 0.67 13 15 150 mg/ml 15.3 0.67 14 16 chx 14.1 0.74 13 15 d.w. 0 0 0 0 table (3): the differences between alcoholic and aqueous propolis extract for all concentration on a.a by using t-test. difference (d.f.=18) t-test p-value 70 mg/ml 7.753 0.000 (hs) 80 mg/ml 3.429 0.003 (hs) 90 mg/ml 1.809 0.087 (ns) 100 mg/ml 0.775 0.449 (ns) 125 mg/ml 1.116 0.279 (ns) 150 mg/ml 2.741 0.013 (s) chx -0.318 0.754 (ns) d.w. figure (1): histogram showed the mean values of inhibition zones of alcoholic and aqueous extracts with +ve and –ve controls against a.a discussion sensitivity of a.a to different concentrations of alcoholic and aqueous extracts of propolis by agar well diffusion method had been tested in this study. results showed that alcoholic and aqueous propolis extracts were able to inhibit the growth of a.a, the diameters of inhibition zones were found to increase when the concentration of the extracts (aqueous and alcoholic) increased, this may be due to the amount of the dissolved active constituents of the extract will be more abundant as the concentrations increase causing increased antimicrobial activity of the extract and also showed that alcoholic extract had more antibacterial activity than aqueous extract this is because the amount of active component in the extract and polarity of the solvent (ethanol alcohol) which has great ability to dissolve the biologically active component of propolis (15). these findings were in coincidence with alammar (16) study of the activity of propolis extracts against pathogenic bacteria include gram positive bacteria (staphylococcus aureus, streptococcus pyogenes) and gram negative bacteria (pseudomonas aeroginosa, escherichia coli) and found that propolis extracts (both aqueous and alcoholic) were effective against gram positive and gram negative bacteria, the activity of both extracts were more on gram positive bacteria than gram negative one and that alcoholic extract was more effective than aqueous extract.the solvent used for propolis extract like ethanol, methanol, chloroform, propylene glycol and others can affectits antimicrobial activity (17). mahmood and abdul hadi studied the effect of turkish propolis (water and methanol) extracts against gram positive bacteria (staphylococcus aureus, staphylococcus epidermidis, bacillus subtilis and bacillus cereus) and gram negative bacteria (salmonella enteritidis, escherichia coli, klebsiella pneumonia) and found that alcoholic propolis extract was active against both types of bacteria s but they found that the watery extract j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 118 had no antibacterial activity which is not in agreement with this study, this may be due to: difference in the source of propolis, methodology of extract and type of target microorganisms (18). references 1. janson h. studies on periodontitis and analyses of individuals at risk for periodontal diseases. swed dent j 2006; 180: 5-49. 2. calas-bennasar, bousquet p, jame o, orti v, gilbert p. clinical examination of periodontal diseases. emcodontologie 2005; 1(2):181-91. 3. doucet p, lowenstein m. osteoclast’s activation by bacterial endotoxins during periodontal diseases. med sci (paris) 2006; 22(6-7): 614-20. 4. van der reijden wa, bosch-tijhof cj, van der velden u, van winkelhoff aj. java project on periodontal diseases: serotype distribution of actinobacillus actinomycetemcomitans and serotype dynamics over an 8-year period. j clin periodontal 2008; 35(6): 487-92. 5. fine dh, kaplan jb, kachlang sc, schreiner hc. how we got attached to actinobacillus actinomycetemcomitans: a model for infectious diseases. periodontal 2000 2006; 42:114-57. 6. rodenburg jp, van winkilhoff aj, winkel eg, goene rj, abbas f, de graff j. occurence of bacteroids gingivalis, bacteroidsintermedius and actinobacillus actinomycetemcomitans in severe periodontitis in relation to age and treatment history. j clin periodontal 1990; 17(6): 392-9. 7. santos fa, bastos ema, rodrigues ph, uzeda m, carvalho mar, farias lm, moreira esa. susceptibility of prevotellaintermédia/ prevotellanigrescens and porphyromonas gingivalis to propolis (bee glue) and other antimicrobial agents. anaerobe 2002; 8(1): 9-15. 8. 8gomes rt, teixeira kir, braga dm, santos vr, cortés me. susceptibilidade in vitro de microorganismos da cavidade oral frente a géis de própolis com e semóxido de zinco (portuguese). versão digital: arquivosemodontologia (suplementoeletrônico) 2004. 40. 9. kubo i, himejima m, muroi h. antimicrobial activity of flavor components of cardamom elettariacardamomum (zingiberaceae) seed. j agric food chem 1991; 39(11):1984–6. 10. kusumoto t, miyamoto rh, doi s, hiroyuki s, yamada h. isolation and structures of two new compounds from the essential of brazilian propolis. chem pharm bull 2001; 49(9):1207-9. 11. bosio k, avanzini c, d’avolio a, ozimo o, savoia. in vitro activity of propolis against streptococcus pyogenes. lett appl microbiol 2000; 31(2):174-7. 12. banskota ah, tezuka y, kadota s. recent progress in pharmacological research of propolis. phytother res. 2001; 15(7): 561-71. 13. burdock ga. review of the biological properties and toxicity of bee propolis (propolis). food chem toxicol 1998; 36(4): 347-63. 14. contari g. process for the propolis extract preparation. apicolt mod 1987; 78:147-50. 15. mahasneh am, abbas ja, el-oqilah aa. antimicrobial activity of extracts of herbal plants used in the traditional medicine of bahrain. plytotherapy res 1996; 10(3): 253-7. 16. al-ammar mh. effects of propolis components on some pathogenic bacteria. master thesis. kufa university, iraq, 2001. 17. onlen y, duran n, atik e, savas l, altug e, yakan s, aslantas o. antibacterial activity of propolis against mrsa and synergism with topical mupirocin. j of alternative and complementary medicine 2007; 13(7) 713-8. 18. mahmood nm, abdul hadi am. effect of water and methanol extracts of turkish propolis against some species of pathogenic bacteria. iraqi j comm med 2012; 3: 210-5. j bagh college dentistry vol. 32(4), december 2020 coated stainless steel 1 coated stainless steel archwires' discoloration measured by computerized system (an in-vitro study) abeer basim mahmood (1) https://doi.org/10.26477/jbcd.v32i4.2911 abstract background: aesthetic archwires are used to overcome the aesthetic problems of stainless steel wires but the color of the coating layer can be changed with time when exposed to oral environments. the aim of this study was to evaluate the degree of color change of different aesthetic archwires from different companies under different coloring solutions. materials and methods: one hundred fifty samples of coated archwires from three companies (highland, g&h and dany) were immersed in 5 solutions (artificial saliva, turmeric, tea, coffee and miranda) to evaluate the degree of color changes after 7, 14 and 21 days using visible spectrophotometer. data were collected and analyzed using one way anova and post hoc tukey’s tests. results: turmeric solution caused high color change than other solutions. aesthetic archwires from highland company showed the highest degree of color change than archwires from other companies. conclusions: turmeric solution produced more discoloration than other solutions and the effects of these solutions are related to different chemical compositions of those solutions. keywords: aesthetic archwires, staining drinks, turmeric,tea, coffee, miranda. (received: 8/10/2019; accepted: 4/11/2019) introduction with the advent of increasing number of adults seeking orthodontic treatment, the development of orthodontic appliances with ample emphasis on esthetics coupled with optimal performance has become an essential goal or rather necessity of the day (1). the demand for esthetic orthodontic appliances has increased dramatically, creating a need for the so-called invisible orthodontic appliances like invisalign, and lingual braces (2). however, esthetics of fixed labial appliances has also evolved by inclusion of ceramic brackets (3), esthetic ligatures and tooth colored archwires (4). esthetic archwire materials are basically a composite of two materials which can be broadly classified into two major groups; composite archwires and coated metallic archwires (5-7). the color stability of esthetic archwires during orthodontic treatment is clinically important. any staining or discoloration or change in esthetic of patient will affect the cooperation and acceptance to his treatment. color instability of these wires and exposure of the underlying metal is also often reported. it has been found that 25% of coating is lost in 33 days intra-orally; therefore, the wire becomes aesthetically degraded (8). coating improves esthetics but has some disadvantages. the color tends to change with time coat as “un-durable”, like other esthetic orthodontic products, and there are internal and external causes for the discoloration of esthetic archwires (9). rofessor, department of orthodontics, college of؛(1) dentistry, university of baghdad. corresponding author, dr_abeerbasim@yahoo.com external discoloration can be caused by food dyes and colored mouth rinses. the type of coating material and its surface roughness play decisive roles in the extent of the discoloration caused by diverse substances. the amount of color change can be influenced by a number of factors including oral hygiene and water absorption (10). discoloration of archwires can be caused by food dyes or mouth washes. the daily consumption of tea, coffee and soft drinks promotes discoloration of these wires (11), so this study was planned to compare the color stability of different brands of esthetic archwires immersed in artificial saliva, black tea, coffee, turmeric and miranda. materials and methods epoxy-coated stainless steel archwire with a dimension of 0.019×0.025 inch were selected from three different companies (highland metals, g&h orthodontic and dany). a total of one hundred fifty segments (50 samples from each company) were prepared by cutting the preformed arch wires into two parts and placing ten parts of the coated archwires segments from each company in several solutions including: artificial saliva, black tea, miranda, coffee, turmeric solution. the solutions were replaced regularly to prevent the precipitation and change in concentration as follow:  black tea and coffee (three times daily)  miranda (two times daily)  turmeric (one time daily) https://doi.org/10.26477/jbcd.v32i4.2911 j bagh college dentistry vol. 32(4), december 2020 coated stainless steel 2 the color change was assessed using a visible spectrophotometer after numbering the specimens of each subgroup from 1 to 10 for each solution by the marker which could not be removed by the solutions. the samples were incubated in distilled water in glass container at 37°c for 24 hours using incubator. baseline measurement was done to measure the light reflection of each specimen by visible spectrophotometer at visible wavelengths started from 300-700ηm at 10ηm intervals. color measurements were repeated after 7 days (t1), 14 days (t2), and 21 days (t3) of immersion in the solution. before each measurement, samples were removed from the solution and rinsed with distilled water for 5 minutes. excess water on the surfaces was removed with tissue papers and then left to dry. statistical analyses the data were analyzed using spss (statistical package of social science) version 24 (ibm co., new york, usa). the statistical analyses included:  descriptive statistics including mean, standard deviation, maximum and minimum values.  inferential statistics: including: one-way analysis of variance (anova) to test any statistically significant difference among groups followed by post hoc tukey’s honestly significant difference (hsd) to test any statistically significant differences between each two groups. results tables 1-3 showed the descriptive statistics and comparison of the degree of color absorption and effect of different solution on coated archwires after 7, 14 and 21 days of immersion respectively. the results revealed that the most potent solutions causing color change were the turmeric and tea among brands and durations. generally, archwires from highland company had the highest degree of color change followed by dany and g&h and the amount of color change increased with increased immersion time. tukey’s hsd test (table 4) showed that the difference between each two groups as followed:  for artificial saliva, there is no significant difference between highland and g&h after 21 days of archwires immersion.  for the turmeric solution, there are high significant differences among all groups for all duration of archwire immersion.  high significant differences have also been found between groups of coffee solution except between highland and g&h after 7 days and between highland and dany after 14 and 21 days of immersion.  for the tea solution, there were no significant differences between most groups except for dany with highland and g&h with high significant differences between them.  the least effective solution was miranda for all archwires and among all durations with no significant differences between groups except for dany with highland and g&h with highland where there were significant differences between them. table 1: descriptive statistics and comparison of the degree of color absorption after 7 days of immersion. media archwires descriptive statistics comparison mean s.d. min. max. f-test p-value turmeric highland 0.690 0.012 0.674 0.702 127.883 0.000 g & h 0.615 0.017 0.600 0.641 dany 0.522 0.020 0.503 0.555 tea highland 0.314 0.015 0.293 0.335 29.140 0.000 g & h 0.297 0.011 0.281 0.311 dany 0.350 0.004 0.344 0.355 coffee highland 0.497 0.009 0.489 0.510 253.324 0.000 g & h 0.492 0.007 0.485 0.500 dany 0.408 0.005 0.400 0.411 miranda highland 0.124 0.013 0.110 0.141 8.257 0.006 g & h 0.113 0.013 0.100 0.132 dany 0.160 0.027 0.120 0.190 j bagh college dentistry vol. 32(4), december 2020 coated stainless steel 3 table 2: descriptive statistics and comparison of the degree of color absorption after 14 days of immersion. media archwires descriptive statistics comparison mean s.d. min. max. f-test p-value turmeric highland 0.818 0.018 0.800 0.844 548.861 0.000 g & h 0.681 0.002 0.679 0.684 dany 0.578 0.008 0.570 0.588 tea highland 0.389 0.008 0.380 0.400 15.184 0.001 g & h 0.359 0.008 0.350 0.371 dany 0.406 0.021 0.390 0.440 coffee highland 0.587 0.005 0.581 0.592 1.199 0.335 g & h 0.521 0.113 0.395 0.612 dany 0.548 0.029 0.520 0.590 miranda highland 0.205 0.016 0.190 0.230 44.411 0.000 g & h 0.190 0.008 0.182 0.201 dany 0.251 0.006 0.244 0.260 table 3: descriptive statistics and comparison of the degree of color absorption after 21 days of immersion. media archwires descriptive statistics comparison mean s.d. min. max. f-test p-value artificial saliva highland 0.019 0.001 0.017 0.020 4.216 0.041 g & h 0.018 0.007 0.011 0.028 dany 0.011 0.004 0.007 0.017 turmeric highland 0.978 0.042 0.910 1.020 91.019 0.000 g & h 0.850 0.024 0.820 0.880 dany 0.704 0.027 0.680 0.750 tea highland 0.491 0.008 0.480 0.500 22.215 0.000 g & h 0.458 0.003 0.455 0.460 dany 0.488 0.013 0.470 0.500 coffee highland 0.687 0.009 0.680 0.699 39.044 0.000 g & h 0.702 0.013 0.690 0.720 dany 0.626 0.019 0.600 0.650 miranda highland 0.342 0.041 0.299 0.390 1.013 0.392 g & h 0.318 0.019 0.299 0.350 dany 0.331 0.011 0.320 0.350 table 4: tukey’s hsd test after anova test media archwires 7 days 14 days 21 days artificial saliva highland g & h 0.941 dany 0.049 g & h dany 0.047 turmeric highland g & h 0.000 0.000 0.000 dany 0.000 0.000 0.000 g & h dany 0.000 0.000 0.000 tea highland g & h 0.074 0.012 0.000 dany 0.001 0.160 0.836 g & h dany 0.000 0.000 0.000 coffee highland g & h 0.541 0.308 0.265 dany 0.000 0.644 0.000 g & h dany 0.000 0.807 0.000 miranda highland g & h 0.658 0.094 0.362 dany 0.028 0.000 0.815 g & h dany 0.006 0.000 0.708 j bagh college dentistry vol. 32(4), december 2020 coated stainless steel 4 discussion the visible spectrophotometer did not give any readings for the artificial saliva during the first two readings i.e. after 7 and 14 days with minimum readings after 21 days of archwire immersion. all solutions altered the final color of the archwire specimens. in an ascending order, staining of the test specimens was as followed: artificial saliva, miranda, tea, coffee and turmeric. the present study showed differences in the degree of color changes for different types of aesthetic archwires from different companies and under the same solutions. this may be due to different chemical and physical compositions of the aesthetic archwires which need further researches to explore the accurate causative agents. the highest degree of color change was recorded with turmeric solution because of the high content of the gold-yellow coloring agent (curcumin) (12). the variation between the readings of coffee and tea solutions was related to the compositions of these solutions. the caffeine content was differed between coffee and tea being high in coffee (70 mg in 237 ml.) as compared to its contents in tea (40 mg in 237 ml.) (13,14). the least degree of color change was found with miranda solution due to the presence of ascorbic and citric acids that may have cleaning effect as compared to tea and coffee that showed some precipitation which increased the staining effect (15). conclusion  turmeric solution had the highest effect on color stability.  the amount of color change increased with increasing immersion time.  coffee solution produced discoloration more than tea which may be related to the amount of caffeine materials.  miranda has the least effect due to the cleaning effect of acidic content. references 1. lagravere mo, flores-mir c. the treatment effects of invisalign orthodontic aligners: a systematic review. j am dent assoc. 2005; 136:1724-9. 2. ye l, kula ks. status of lingual orthodontics. world j orthod. 2006; 7: 361-8. 3. lee yk. colour and translucency of tooth-coloured orthodontic brackets. eur j orthod. 2008; 30: 205-10. 4. feu d, catharino f, duplat cb, capelli jj. esthetic perception and economic value of ort hodontic appliances by lay brazilian adults. dental press j orthod. 2012; 17:102‐14. 5. elayyan f, silikas n, bearn d. mechanical properties of coated superelastic archwires in conventional and self-ligating orthodontic brackets. am j orthod dentofacial orthop. 2010; 137: 213-7. 6. kusy rp. the future of orthodontic materials: the long-term view. am j orthod dentofacial orthop. 1998; 113: 91–5. 7. kusy rp. a review of contemporary archwires: their properties and characteristics. angle orthod. 1997; 67: 197-208. 8. li y, hu b, liu y, ding g, zhang c, wang s. the effects of fixed orthodontic appliances on saliva flow rate and saliva electrolyte concentrations. j oral rehabil. 2009; 36: 781-5. 9. lim kf, lew kk, toh sl. bending stiffness of two aesthetic orthodontic archwires: an in vitro comparative study. clin mater. 1994; 16: 63-71. 10. mccabe jf. anderson’s applied dental materials. 6th ed. blackwell scientific publications; 1985. pp.9, 43, 46, 65-66, 68. 11. proffit wr. contemporary orthodontics. 3rd ed. st. louis: mosby company; 2000. 12. faltermeier a, rosentritt m, reicheneder c, behr m. discoloration of orthodontic adhesives caused by food dyes and ultraviolet light. eur j orthod. 2008; 30: 89– 93. 13. lagravere mo, flores-mir c. the treatment effects of invisalign orthodontic aligners: a systematic review. j am dent assoc. 2005; 136: 1724-9. 14. ye l, kula ks. status of lingual orthodontics. world j orthod. 2006; 7: 361-8. 15. lee yk. colour and translucency of tooth-coloured orthodontic brackets. eur j orthod. 2008; 30: 205-10. الخالصة الجمالية لألسالك المصنوعة من الفوالذ المقاوم للصدأ، لكن يمكنتُستخدم األسالك التجميلية للتغلب على المشكالت :الخلفية التغيراللوني درجة هوتقييم الدراسة هذه من الهدف كان. الفم لبيئة تتعرض عندما الوقت مرور مع الواقية الطبقة تغييرلون .مختلفة تلوين محاليل باستخدام مختلفة شركات من المختلفة الجماليةللوايرات 5 في (dany و g&h و highland) شركات ثالث من المطلية العينات من عينة وخمسين غمرمائة تم: والطرق المواد يوما 14 و 41 و 7 بعد األلوان تغيرات درجة لتقييم( وميراندا والقهوة والشاي والكركم االصطناعي اللعاب) محاليل tukeyو anova ياختبار باستخدام وتحليلها البيانات جمع تم. المرئي الطيف مقياس باستخدام شركةهايالند من الجمالية العينات أظهرت. األخرى المحاليل مع بالمقارنة عالي اللون فيتغير الكركم حل تسبب: النتائج .األخرى الشركات من بالعينات مقارنة تغييراللون من درجة أعلى لتلك مختلفة كيميائية بتركيبات المحاليل آثارهذه وترتبط األخرى المحاليل أكثرمن تلونًا الكركم محلول أنتج :االستنتاجات .المحاليل majida final.doc j bagh college dentistry vol. 26(3), september 2014 the antibacterial evaluation restorative dentistry 35 the antibacterial evaluation of dandelion extracts as root canal irrigating solutions (a comparative study) nada eyad shafiq, b.d.s. (1) majida k. al-hashimi b.d.s., m.sc. (2) abstract background: irrigation has a central role in endodontic treatment. several irrigating solutions have the antimicrobial activity and actively kill bacteria and yeasts when introduced in direct contact with the microorganisms. the purpose of this study was to evaluate the antimicrobial effectiveness of dandelion (taraxacum officinale) root and leaf extracts as possible irrigant solutions, used during endodontic treatments, and both were compared to sodium hypochlorite, propolis and ethyl alcohol. materials and method: forty seven human extracted single rooted teeth were selected. the teeth were decoronated using a diamond disk to have a length of 15 mm ±1 mm and they were instrumented using the hybrid technique. all roots were sterilized by an autoclave, five roots without bacterial inoculation served as the negative controls, the rest were inoculated with enterococcus faecalis, then five roots were selected randomly as the positive controls, then the remaining 37 roots were divided into five groups of 8 samples each except group v with 5 roots. group i: irrigated with propolis extract. group ii: irrigated with dandelion leaf extract. group iii: irrigated with dandelion root extract. group iv: irrigated with sodium hypochlorite. group v: irrigated with ethyl alcohol. bacterial swabs were taken from each root and cultured. bacterial growths were calculated by counting the number of colonies appeared on the cultures. results: the results were statistically analyzed; within the limitation of this in vitro study, the dandelion leaves extract and dandelion root extract proved to have some antimicrobial properties. sodium hypochlorite has the best antimicrobial effect, followed by propolis, dandelion root, ethyl alcohol then dandelion leaf. conclusion: dandelion root and leaf extracts are possible irrigant solutions that can be used successfully during endodontic treatments, to aid disinfection of the root canal system. keywords: taraxacum officinale, enterococcus facaelis,propolis. (j bagh coll dentistry 2014; 26(3):35-40). الخالصة مضادة للبكتریا وتستطیع القضاء على البكتریا و الفطریات عندما ور وھيتستعمل لغسل قنوات الجذر مختلفة الك موادھن. تھالھ دور اساسي خالل معالج االسنانغسل قنوات جذران .الدقیقةالمرضیة تستعمل وتوضع بصورة مباشرة مع ھذه الكائنات ن خالل عملیة معالجة ناسر االوغسل قنوات جذلات الھندباء الستعمالھ كمادة نبالغرض من ھذه الدراسة ھو تقییم القابلیة المضادة للمایكروبات لمستخلص الجذور ومستخلص االوراق ل .و الكحول االثیلي) صمغ النحل(و العكبر ومقارنة ھذه المستخلصات مع ھایبوكلورایت الصودیوم, ر االسنانوقنوات جذ تم تعقیم الجذور بواسطة . باستخدام التقنیة الھجینة القنوات یق قطع تاج السن وتم تحضیرملم عن طر 15االسنان قصرت الى طول , واربعون سن بشري سبعلھذه الدراسة تم اختیار .مجامیع 5ثم تم زراعة قنوات االسنان ببكتیریا المكورات المعویة وتم تقسیم االسنان الى , جھاز التعقیم .عشرة اسنان تم غسل قنواتھا باستعمال مستخلص العكبر: i مجموعة .ة اسنان تم غسل قنواتھا باستعمال مستخلص اوراق نبات الھندباءعشر: iiمجموعة .عشرة اسنان تم غسل قنواتھا باستعمال مستخلص جذور نبات الھندباء:iii محموعة .عشرة اسنان تم غسل قنواتھا باستعمال ھایبوكلورایت الصودیوم: ivمجموعة .الثیليسبعة اسنان تم غسل قنواتھا باستعمال الكحول ا: vمجموعة و معالجة .تم حساب عدد البكتیریا المزروعة بواسطة حساب عددالمستعمرات البكتیریة التي ظھرت على الوسط الزرعي. بعد ذلك تم اخذ مسحة بكتیریة من كل قناة جذر وتم زراعتھا .النتائج احصائیا وان ھایبوكلورایت . مستخلص جذور نبات الھندباء یحتوي على بعض الخواص المضادة للبكتیریاوجد ان مستخلص اوراق و, ضمن الظروف المختبریة التي تمت خاللھا ھذه الدراسة اق نبات الھندباءالصودیوم اظھر افضل خاصیة مضادة للبكتیریا مقارنة مع كل المواد المستعملة في ھذه الدراسة یتبعھ العكبر ثم جذور نبات الھندباء واور introduction the success of endodontic treatment depends on the elimination of microbes (if present) from the root-canal system and prevention of reinfection. chemomechanical preparation of the infected root canal using antimicrobial agents, followed by obturation and coronal restoration, provides a favorable outcome. the root canal system is instrumented using hand or rotatory instruments, a study using advanced techniques such as microcomputed tomography (ct) scanning have demonstrated that proportionally large areas of the main root-canal wall remain untouched by the instruments. this study showed the importance of chemical means of cleaning and disinfecting all areas of the root canal (1). (1) m.sc. student. department of conservative dentistry, college of dentistry, university of baghdad (2) professor. department of conservative dentistry, college of dentistry, university of baghdad disinfection of the root canal system, as part of endodontic therapy, by preparation and irrigation is the key in reducing the number of bacteria within the root canal and helping to control periapical disease (2). a variety of antibacterial irrigation solutions may be used to irrigate and disinfect root canals in conjunction with root canal preparation. sodium hypochlorite is the most common irrigant used in endodontics until now. it is an effective antimicrobial agent and an excellent organic tissue solvent (3), but has its numerous drawbacks like unpleasant odour and taste and, even more relevant, the high toxicity when it is extruded into the periapical tissues. chlorhexidine gluconate is a broad-spectrum antimicrobial agent that has substantive antibacterial activity and relatively low toxic effects, but it does not dissolve organic tissues (4). j bagh college dentistry vol. 26(3), september 2014 the antibacterial evaluation restorative dentistry 36 the enterococcus faecalis is known to be an important resistant species in the infected root canals, and they may cause treatment failures (5). the search for alternative irrigating solutions has focused on the substances with antibacterial effect and capacity to clean dentin surfaces.herbal products have been used since ancient times in folk medicine, involving both eastern and western medicinal traditions. many plants with biological and antimicrobiological properties have been studied. herbal or natural products have been used in dental and medical practice for thousands of years and have become even more popular today due to their high antimicrobial activity, biocompatibility, anti-inflammatory and antioxidant properties (6). the purpose of this, in vitro, study was to evaluate the effectiveness of dandelion root& leaf extracts (taraxacum officinale) as possible irrigants in endodontics; against enterococcus faecalis in comparison with sodium hypochlorite, propolis and ethyl alcohol. matrtials and methods preparation of the samples forty seven extracted single rooted teeth were collected from different dental centers in iraq. the teeth were decoronated, using a diamond disk in a straight hand piece to have length of 15 mm ±1 mm and the length of each tooth was verified by digital vernier. the roots were instrumented using the hybrid technique;with each file change, the canals were irrigated with 2 ml distilled water to remove the debris. the files were discards after using with every five uses.the apical foramen was sealed with light-cured restorative glass ionomer cement. the other surfaces of the roots were covered with two layers of nail varnish. microbiological procedure the method of bacterial inoculation and culturing, used in this study, was similar to the method used by mehrvarzfar et al. (11) 1. first step • all roots were sealed with aluminum foil and placed in a container filled with distilled water, then sterilized by an autoclave for 30 minutes at 121˚c under a pressure of 15 psi. • brain heart infusion broth was prepared according to the manufacturer's instructions by weighting 37 gm of brain heart infusion powder. the powder was dissolved in one liter of distilled water. then it was mixed well and placed on a heater to complete the dissolution until boiling, leaving the broth to boil for one minute. after it became colder, it was poured into glass tubes with screw cap (25 ml). the cover was sealed well then autoclaved for 15 minutes at 121˚c under a pressure of 15 psi. • each root was transported to a glass tube that contains sterile bhi broth by a sterile forceps; inside hood cabinet and beside the flame of a burner. • the tubes containing the roots were incubated at 37˚c for 48 hours to ensure the sterilization of the roots. the roots were daily examined for no turbidity. • after 48 hours, each root was transported to a sterile eppendr of tube using a sterile forceps under sterile conditions. 2. second step five teeth were selected randomly to serve as the negative controls. • enteroccocus faecalis suspension was prepared as follows: • the pure isolate of enteroccocus faecalis was inoculated to brain heart infusion broth and incubated at 37˚c overnight. the bhi broth at a concentration of 1.5x10⁸ cfu/ ml was used for inoculation. the bacterial suspension was adjusted to match the turbidity of mcfarland 0.5 scale.bacterial suspension of 0.01 ml (10 µl) was inoculated into each canal (42 roots) using sterile insulin syringes. then the roots (47 roots) were incubated for three weeks under aerobic conditions at 37˚c. the inoculum inside the canals was replaced with 0.01 ml (10 µl) of fresh bacterial suspension every other day. • after the incubation period, five inoculated roots were selected randomly to act as the positive controls. • experimental groups: 1. gi propolis: 8 roots for propolis 12% (120 mg/1 ml). 2. g ii dandelion leaf: 8 roots for dandelion leaf 0.7% (7 mg/ 1 ml). 3. giii dandelion root: 8 roots for dandelion root 0.7% (7 mg/ 1 ml). 4. giv naocl: 8 roots for sodium hypochlorite 2.5 %. 5. gv ethyl alcohol: 5 roots for ethyl alcohol 55%. 3. third step • plain tubes, paper points, insulin syringes, 10 ml disposable syringe and forceps were sterilized by uv light for 30 minutes. j bagh college dentistry vol. 26(3), september 2014 the antibacterial evaluation restorative dentistry 37 • preparations of dilutions of the plants extracts, then all dilutions were mixed well by vortex device for 20 seconds. 4. fourth step • group one were irrigated with 8 ml of the irrigant (1 ml for each root). • after 5 minutes the irrigant was withdrew using a sterile syringe; a sterile paper point was grasped by sterile forceps then inserted inside the canal and moved in a circular direction for 10 seconds to allow collection of bacteria and remaining irrigant material. • the paper point then transported to a plain tube containing sterile 10 ml of normal saline and mixed by vortex for 20 seconds. • one ml of the mixture was drawn using a sterile syringe and transported to another plain tube containing 9 ml of normal saline which was then mixed by vortex for 20 seconds. • again 1 ml of the mixture was drawn using a sterile syringe and transported to another plain tube containing sterile 9 ml of normal saline, mixed by vortex for 20 seconds. • after that 1ml of the mixture was collected from the last plain tube and discharged as this step done in accordance with procedure of serial dilutions. • five µl were taken of the mixture of the last plain tube and applied to bile esculine agar culture plates and spread by a sterile loop and incubated at 37˚c overnight. • one ml of the irrigant that was collected is readded to the canal and let for another 5 minutes and the steps were repeated from the withdrew of the irrigant from the canal using a sterile syringe and a sterile paper point insertion inside the canal to allow collection of the bacteria till the bacterial counting to obtain 10-min duration. • another 1 ml of the irrigant was re-added to the canal and left for another 5 minutes and the same procedure was repeated to obtain 15-min duration. the above procedure was repeated with all the experimental groups. after the incubation periods of the petri dishes that were inoculated with microbial swabs from the roots. bacterial growths were calculated by counting the number of colonies appeared on each dish. the results were statistically analyzed by kruskal-wallis h test and mann-whitney u test. results according to the results of this study, with the respect of the duration test, all the tested irrigation solutions reduced the number of enterococcus faecalis colonies with different values. mann-whitney u test was used to compare the paired groups, within each irrigation duration, (table 1 and figure 1), in which highly significant differences were recorded in most of the compared groups. however, in the 5-min duration there were no significant differences between the groups i vs. iv; ii vs. iii and a significant difference between the group iv and v; in the 10min duration there were significant differences between the groups i vs. iii and i vs. iv. finally, in the 15-min duration there were no significant differences between the groups i vs. iii and ii vs. v. table 1: mann-whitney u test results comparing paired groups in each duration duration groups p-value 5 min. i ii 0.000 (hs) iii 0.000 (hs) iv 0.057 (ns) v 0.003 (hs) ii iii 0.073 (ns) iv 0.001 (hs) v 0.003 (hs) iii iv 0.001 (hs) v 0.003 (hs) iv v 0.011 (s) 10 min. i ii 0.001 (hs) iii 0.017 (s) iv 0.048 (s) v 0.003 (hs) ii iii 0.001 (hs) iv 0.001 (hs) v 0.003 (hs) iii iv 0.004 (hs) v 0.003 (hs) iv v 0.002 (hs) 15 min. i ii 0.001 (hs) iii 0.087 (ns) iv 0.000 (hs) v 0.003 (hs) ii iii 0.001 (hs) iv 0.000 (hs) v 0.878 (ns) iii iv 0.004 (hs) v 0.007 (hs) iv v 0.001 (hs) j bagh college dentistry vol. 26(3), september 2014 the antibacterial evaluation restorative dentistry 38 figure 1: bar chart of the mean of enterococcus faecalis colonies versus irrigation duration for all tested groups discussion bacterial infections and inflammation are among the ailments treated by traditional healers. the world health organization has expressed high interest in traditional medicine. world health organization data show that 80% of the world population use plant extracts and content in treatment of diseases (7). this study was an attempt to clarify whether intracanal irrigation with dandelion leaf and root extracts would be able to eradicate enteroccocus faecalis contaminating root canals. enterococcus faecalis is one of the most frequently isolated species (8, 9); it can be found at depths up to 300 μm within dentinal tubules; where it is able to survive notwithstanding the scant available nutrients, unlike other bacterial species. furthermore, enterococcus faecalis appears to be very resistant to the action of endodontic dressing like ca(oh)2, because of its capability to survive at a very high ph; it can resist heat, u.v., ethanol, hydrogen peroxide and acidity, therefore; it can persist and survive in treated root canal systems (10). the method of bacterial inoculation and culturing, used in this study, was similar to the method used by mehrvarzfar et al. (11). in the present study, the antimicrobial activity of hydroalcoholic extract of 12% propolis, 0.7% hydroalcoholic extract of dandelion leaf and dandelion root, 2.5% sodium hypochlorite and 55% ethyl alcohol were compared. the use of the most effective antimicrobial irrigant has a clinical importance for successful endodontic treatment. a concentration of 2.5% sodium hypochlorite had been used as an intracanal irrigant against enterococcus faecalis. since a solution of 2.5% naocl is generally used when treating teeth with necrotic pulp and apical periodontitis. also naocl solutions at higher concentrations have a greater irritating effect on the apical and periapical tissues (12).the acceptable cytotoxic level of naocl is 0.5%, but this concentration is less effective (5). twelve percent of propolis extract, which was used in this study, found to be an effective intracanal irrigant against enterococcus faecalis. the antimicrobial activity of propolis extract on the microorganisms was verified by different studies (13, 14). the antibacterial activity of taraxacum officinale leaves and roots extracts had been evaluated, since they have been used for hundreds of years to treat liver, gallbladder, kidney, and joint problems. recently the plant extracts were investigated in several studies to find possible antimicrobial effect against many pathogens (15-17). dandelion root extract and leaf extract were used in this study; a concentration of 0.7% in accordance with a study used the aqueous extract of dandelion and since it showed antibacterial properties at concentration 7.0 mg/ml.(15). dandelion extracts, in this study, proved to have antimicrobial properties, both extracts reduced the number of colonies of the tested pathogen, this is in agreement with many studies which verified the antimicrobial activity of this plant extracts against many pathogenic microorganisms (15, 17, 18). fifty five percent of ethyl alcohol was used, as an intracanal irrigant, and its antimicrobial effect was compared with the other tested irrigants. it is used in this study as alcohols exhibit rapid broadspectrum antimicrobial activity against vegetative bacteria (including mycobacteria), viruses, and fungi but are not sporicidal (19). when comparing among these groups, 2.5% sodium hypochlorite, found to reduce the bacterial colonies very effectively. this antimicrobial activity may be related to bacterial essential enzymatic sites promoting irreversible inactivation by hydroxyl ions and the chloramination reaction, sodium hypochlorite when comes in contact with organic tissue, releases chlorine that combine with the protein amino group to form chloramine which interferes with the cellular metabolism (12). the results of this study, regarding the effectiveness of 2.5% of sodium hypochlorite, are in agreement with several studies, such as mehrvarzfar et al. (11). according to this study, propolispossess good antimicrobial properties against the tested pathogen which is in agreement with mattigatti et al. and ehsaniet al. (20,21). it has a higher antibacterial action in 5, 10 and 15 minutes than dandelion leaf extract, dandelion root extract and ethyl alcohol. this may be due to some active j bagh college dentistry vol. 26(3), september 2014 the antibacterial evaluation restorative dentistry 39 components present in propolis. the real mechanism of the antimicrobial action of propolis appears to be complex and not yet fully understood, however, its active agents, include flavonoids, phenolic and aromatic compounds like caffeic acid (22). while insignificant difference was found between propolis and sodium hypochlorite in 5 minutes duration indicating that both irrigants were effective and any one of them can be used, this is in agreement with a study conducted by mattigatti et al. (20). propolis was more effective on enterococcus facaelis as the contact time increased. dandelion leaf and dandelion root extract, used in this study, proved to have some inhibitory effect on the growth of the tested pathogen. the inhibitory effects may be due to the glycosides and/or phenolic compounds and/or tannins and/or flavonoids and/or alkaloids and/or proteins presence in the plant extracts. such compounds had been reported to have an active effect on the bacterial cells membrane, which might destroy these microorganisms (23). the alkaloids interact with the dna, the tannins inhibit the carrier enzymes and proteins present in the cells membrane, while the phenolic compounds form a complex with the dissolved protein out of the cells or with cells membrane which may destroy the bacteria, another possible reason for antibacterial effect is that taraxacum officinale had higher saponin content with higher antimicrobial potential as kannabiran et al. (24) reported that there was linear relation with the saponin content and antimicrobial activity (25). the screening of phytochemical constituents of this plant‘s ethanolic extract by lateef and issah (16) revealed the presence of saponin, phenolics, reducing sugar, anthracenosides, triterpenes, steroids, tannins, and phlobatanins. these compounds are known to be biologically active and, therefore; aid in the antimicrobial activities of dandelion. moreover, these classes of compounds are reported to have activity against several pathogens, therefore; the results support the use of taraxacum officnale as antimicrobial agents during endodontic treatment. the antibacterial findings of this study regarding dandelion disagree with khan et al. study (26) as they found that methanolic extract of taraxacum officinale did not show antibacterial activity against entercoccus faecalis but it had antifungal activity. these differences in antimicrobial susceptibility tests may be due to variations in methodology, since several factors (inoculum amount, medium composition, ph, incubation, type of the extraction whether it is methanol, ethanolic or aqueous) can influence the interaction between microorganisms and antimicrobial agents, thus affecting the results. dandelion leaf and roots showed no significant difference between both extracts at 5 minutes duration but there was a difference between them at 10 and 15 minutes with the root extract being slightly more effective and this may be due to the presence of a little difference in the percentage of the active phytochemicals (alkaloid, flavonoid, saponin and phenols) found in the leaf or root extracts of dandelion as found in a study by mir et al. (27). both extract showed better activity than ethyl alcohol with the time. ethyl alcohol showed antibacterial effect at 5 minutes duration. little is known about the specific mode of action of alcohols, but based on the increased efficacy in the presence of water; it is generally believed that they cause membrane damage and rapid denaturation of proteins, with subsequent interference with metabolism and cell lysis (19). in this study, ethyl alcohol irrigant found to be less effective than propolis, sodium hypochlorite with the last one had the best antibacterial effect. this result was in agreement with a similar pervious study used 21% alcohol along with various endodontic irrigants against six selected microorganisms, the study found that sodium hypochlorite is the most effective irrigant (28). the evaporation of alcohol may be the reason behind decreasing ethyl alcohol effectiveness after 10 and 15 minutes duration. at 15 minutes, there were no significant differences between ethyl alcohol and dandelion leaf extract and between propolis and dandelion root extract, this is may be caused by the loss of effect of the biologically active components in these irrigants with the time. according to the results obtained in this study, the highest antibacterial irrigant, at 5 minutes, was sodium hypochlorite followed by propolis, ethyl alcohol, dandelion leaf, dandelion root being the least effective. while at 15 minutes, sodium hypochlorite followed by propolis then dandelion root which showed increased activity followed by ethyl alcohol along with the dandelion leaf and these findings may indicate, increasing the contact time of dandelion extracts has better antibacterial effect. within the circumstances of this study, the following conclusions could be withdrawn: • all the irrigants used in this study had variable antimicrobial properties against enterococcus faecalis. • both dandelion leaf and dandelion root extracts can be used as possible irrigant j bagh college dentistry vol. 26(3), september 2014 the antibacterial evaluation restorative dentistry 40 solutions during endodontic treatment to aid disinfection of the root canal system. • the antimicrobial effect of dandelion extracts was improved with increasing the contact time. • sodium hypochlorite and propolis had better antimicrobial properties than dandelion extracts. references 1. peters oa, scho¨nenberger k, laib a. effects of four ni-ti preparation techniques on root canal geometry assessed by micro computed tomography. int endod j. 2001; 34: 221-30. 2. hülsmann m, heckendorff m, lennon a. chelating agents in root canal treatment: mode of action and indications for their use. int endod j 2003; 36: 810-30. 3. ercan e, ozekinci t, atakul f, gül k. antibacterial activity of 2 % chlorhexidine and 5.25 % sodium hypochlorite in infected root canal: in vivo study. j endod 2004; 30: 84-7. 4. mohammadi z, abbott pv. the properties and applications of chlorhexidine in endodontics. int endod j 2009; 42: 288-302. 5. tirali r, turan y, akal n, karahan z. in vitro antimicrobial activity of several concentrations of naocl and octenisept in elimination of endodontic pathogens. oral surg oral med oral pathol oral radiol endod 2009; 108: 117-20. 6. cogulu d, uzel a, sorkun k. efficacy of propolis as an intracanal medicament against enterococcus faecalis. gen dent 2006; 54: 319-22. 7. eloff j. the presence of antibacterial compounds in anthocleista grandiflora (loganiaceae). south afr j bot 1998; 64: 209-12. 8. krause t, liewehr f, hahn c. the antimicrobial effect of mtad, sodium hypochlorite, doxycycline, and citric acid on enterococcus faecalis. j endod 2007; 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21(1): 25-31. 14. ferreira f, torres s, da silva rosa o, ferreira c, garcia r, marcucci m. antimicrobial effect of propolis and other substances against selected endodontic pathogens. oral surg oral med oral pathol oral radiol endod 2007; 104: 709-16. 15. jaca t and kambizi l. antibacterial properties of some wild leafy vegetables of the eastern cape province, south africa. j medicinal plants res 2011; 5(13): 2624-8. 16. lateef o, issah y. screening ethanolic and aqueous leaf extracts of taraxacum offinale for in vitro bacteria growth inhibition. j pharmaceutical and biomedical sci 2012; 20: 1-4. 17. ghaima k, hashim n, ali s. antibacterial and antioxidant activities of ethyl acetate extract of nettle (urtica dioica) and dandelion (taraxacum officinale). journal of applied pharmaceutical sc 2013; 3(5): 969. 18. hleba l, kačániová m, vuković n, petrová j, felš ciová s, pavelková a, rovná k. antibacterial activity of some wild medical plants extract to antibiots resistant escherichia coli. j microbiology, biotechnology and food sci 2013; 2(special issue on bqrmf): 1215-24. 19. mcdonnell g, russell d. antiseptics and disinfectants: activity, action, and resistance. clin microbiol rev 1999; 12: 147-79. 20. mattigatti s, jain d, ratnakar p, moturi s, varma s, rairam s. antimicrobial effect of conventional root canal medicaments vs propolis against enterococcus faecalis, staphylococcus aureus and candida albicans. j contemporary dental practice 2012; 13(3): 305-9. 21. ehsani m, marashi m, zabihi e, issazadeh m, khafri s. a comparison between anti-bacterial activity of propolis and aloe vera on enterococcus feacalis (an in vitro study). int j mol cell med 2013; 2(7):110-7. 22. arslan s, ozbilge h, kaya e, er o. in vitro antimicrobial activity of propolis, biopure mtad, sodium hypochlorite, and chlorhexidine on enterococcus faecalis and candida albicans. saudi med j 2011; 32(5): 479-83. 23. kitts d, hu c. dandelion (taraxacum officinale) flower extract suppresses both reaction oxygen species and nitric oxide and prevents lipid oxidation in vitro. phytomedicine 2005; 12: 588-97. 24. kannabiran k, ramalingham r, venkatesan g. antibacterial activity of saponin isolated from the leaves of solatium trilobatum linn. j app bio sci 2008; 2: 109-12. 25. khan m, aleem qureshi r, faizan ullah, aneel gilani s, nosheen a, sahreen s, laghari m, laghari m, ur-rehman s, hussain i and murad w. phytochemical analysis of selected medicinal plants of margalla hills and surroundings. j medicinal plants res 2011; 5(25): 6017-23. 26. khan m, aleem qureshi r, aneel gillani s and faizan ullah. antimicrobial activity of selected medicinal plants of margalla hills, islamabad, pakistan. j medicinal plants res 2011; 5(18): 466570. 27. mir m, sawhney s, jassal m. qualitative and quantitative analysis of phytochemicals of taraxacum officinale. wudpecker j pharmacy and pharmocology 2013; 2(1): 1-5. 28. ayhan h, sultan n, cirak m, ruhi m, bodur h. antimicrobial effects of various endodontic irrigants on selected microorganisms. int endod j 1999; 32(2): 99-102. ghasaq.doc j bagh college dentistry vol. 27(1), march 2015 histological and restorative dentistry 26 histological and histomorphometric analysis of strontium chloride coated commercially pure titanium implant compared with hydroxyapatite coating ghasak h. jani, b.d.s. (1) shatha s. al-ameer, b.d.s., m.sc. (2) salam n. jawad, b.d.s., m.sc. (3) abstract background: in recent years, the immediate loading of dental implants has become more accepted as a standard protocol for the treatment of the edentulous area. success in implant dentistry depends on several parameters that may improve phenomenon of osseointegration and new bone formation in close contact with the implant. the aim of study was to evaluate the effect of strontium chloride coating of screw shape commercially pure titanium dental implant osseointegration at bone implant interface by histomorphometric analysis and compare with hydroxyapatite coating at 2 time periods (2 weeks and 6 weeks). materials and methods: electrophoretic deposition technique (epd) was used to obtain a uniform coating layer on commercially pure titanium screws. the tibia of 4 white new zealand rabbits was chosen as implantation sites. each tibia of rabbit received two screws, one strontium chloride coated and one hydroxyapatite coated and a total 30 histological sections were obtained for each coating material in each period of time. histomorphometric analysis was performed to measure new bone formed ratio between implant and original bone, after 2 and 6 weeks healing periods. results: there was increased in new bone formation ratio for the strontium chloride coated implants than hydroxyapatite coated implants and over the two periods of time. there was an increase in the new bone formation ratio at bone-implant interface with time. conclusion: coating commercially pure titanium implant with strontium chloride was more efficient in increasing osseointegration at bone implant interface than hydroxyapatite , which was demonstrated by higher new bone formation and maturation at the two periods of time 2 weeks and 6 weeks after implantation. keywords: histomorphometric, commercially pure titanium, strontium chloride, hydroxyapatite. (j bagh coll dentistry 2015; 27(1):26-31). introduction implants are one of the most an important therapeutic surgical procedures providing both an aesthetic and functional alternative to tooth replacement. procedures involving dental implants have grown steadily, rising consistently over the last 20 years to reach approximately one million performed annually worldwide. (1,2) dental implants vary in material, dimensions, geometries, surface properties and interface geometry, so today the dentist needs to select from more than 2,000 different dental implants and abutments in a specific treatment situation. (3) the success of implant fixation is highly dependent on the implant surface poperties to improve integration by different surface coating technologies for promoting osseointegration .(4) osseointegrationwas defined as a direct structural and functional connection between ordered living bone and the surface of a load-carrying implant. (1) master student. department of prosthodontics, college of dentistry, university of baghdad. (2) professor, department of prosthodontics, college of dentistry, university of baghdad. (3) pathologist. ministry of health. baghdad, iraq in practice, this means that in osseointegration there is an anchorage mechanism where by nonvital components can be reliably and predictably incorporated into living bone and that this anchorage can persist under all normal conditions of loading. (5) a relatively new anti-osteoporotic drug, strontium ranelate (protelos), is proposed to induce, in contrast to other anti-osteoporotic drugs (like bisphosphonate), simultaneously both an anti-resorption and bone forming effect. (6,7) strontium is a trace metal in human body and its physiologically stable divalent cationic form (sr+2the ion has a relatively high affinity to bone and may replace ca in apatite crystals by ion exchange. strontium ranelate contains two sr+2 ions and ranelic acid. (8,9) histomorphometric measurement is a representative test in studying the nature of the implant-tissue surface and has been used by several authors to evaluate the bone implant interface. (10) atsumi et al. categorize it as the method of highest reliability to evaluate implant stability that can be performed at any time (pre, intra or post) of the implantation. (11) the purpose of this study was to make histological and histomorphometric analysis of strontium chloride srcl2) and hydroxyapatite j bagh college dentistry vol. 27(1), march 2015 histological and restorative dentistry 27 (ha) coated implant, in rabbit tibia at 2 and 6 weeks implantation time. materials and methods specimens preparation eight screws shaped implants, 3.0 mm in diameter and 8mm in length (threaded part is 5mm and smooth part is 3mm) and pitch height is 1mm, were machined from commercially pure titanium rods grade 2 using lathe machine, with slit in head of the implant to fit the screwdriver during insertion. the screws were washed in ethanol in an ultrasonic cleaner for 15 minutes and dried at 100°c for 15. four screws shaped implants were coated with strontium chloride for 4 min with 20 v and sintering to 450 ºc under inert gas (argon) (12) and the second group was coated with ha for 4min with 40 v and sintering to 800 ºc under inert gas (argon) according to hamed (13). figure 1: screws shaped implants animals and surgical procedures four healthy adult new zeeland rabbits of both sexes weighing 2 -2.5 kg were used. antibiotic cover with oxytetracycline intramuscular injection was given to exclude any infection.rabbit was left for two weeks in the same environment before surgical operation. each animal was weighed before operation to determine the required dose of anesthesia and antibiotic. anesthesia was induced by intramuscular injection of ketamine hydrochloride (1ml/kg body weight) and xylocaine 2% (1ml/kg b.w.)tibia was shaved using shaving spray from medial side and skin was cleaned with ethanol. later on the incision was made to expose the medial side of the tibia, the skin and fascia flap was reflected. bone penetration was performed by engine with straight hand piece (strong 90, korea) with a round guide drill of 2.0mm in diameter to make hole with continuous cooling with normal saline. the enlargement of this hole was made gradually with drills then washed with saline to remove debris. ha coated screws was placed in the hole using screw driver that fit the screw slit until 5mm of the screw was completely introduced into the bone tissue and checked for stability. the sr coated screw was placed within other hole. suturing of muscles was done with absorbable catgut suture followed by skin suturing with silk suture the operation site was sprayed with local antibiotic (oxytetracycline spray),then long acting systemic antibiotic (oxytetracycline 0.5ml/kg b.w.). postoperative care was performed by giving oxytetracycline antibiotic (local and systemic) for 3 days after surgery histological test four animals from each group were used for histological testing.bone sectioning was performed while the animal was anesthetized with overdose of medication. a disc cutter with low rotating speed and vigorous cooling was used for cutting the bone around the implant. cutting was made 5mm away from the head of the implant to prepare a boneimplant block for histological study. bone-implant blocks were immediately stored in 10% freshly prepared formalin and left for overnight for fixation after fixation, bone decalcification was done by immersion the specimens in 10% solution nitric acid. in general, decalcification takes from 2 to 3 days. after that time the specimen was tested for complete decalcification by penetration of a narrow needle to the deepest part of the boneimplant block. a precipitant was formed if any amount of calcium is present. if any precipitate is formed, the acid solution covering the specimen should be changed. if no precipitate is detected it is assumed that the specimen is completely decalcified then the implant was gently removed from its bone bed. (14) after complete decalcification, the bone implant block was divided horizontally into two parts using a sharp scalpel with cross section of the implant inside the bone to be divided into two levels. dehydration of the specimen was done by immersing it in alcohol with serial concentration (70%, 80%, 90% and absolute alcohol remaining in each dish for one hour). the specimens then were passed through two changes of xylene for 15-20 min. each specimen was placed in a dish of melted paraffin and the dish was kept into a constant-temperature oven regulated to about 60º c during the course of several hours. the specimen was changed to two or three successive dishes of paraffin so that all of the xylene in the tissue was replaced by paraffin. the specimens were moulded in the center of paraffin block, and adjusted to microtome where j bagh college dentistry vol. 27(1), march 2015 histological and restorative dentistry 28 serial sectioning with (4-5) µm of thickness for each section was performed and placed on a slide. the slide was placed in a container having haematoxylin and eosin stain for 10 minutes to stain the tissue. each bone implant block was divided into 2 levels and from each level 3 slides were obtained. total of 30 sections were made for each coating material in each period of time. by light microscope with samsung, gtn7100 camera, photographs of each section were taken at x4 power magnification and enlarged. the area of new bone was marked and measured using image j software (nih image, national institutes of health, maryland, usa) the area of new bone was marked according to criteria stated by shapiro, as look like coarse meshwork (trabecule bone) of pink tissue surrounding patches of much lighter or unstained tissue or matrix. (15) the percent rate of new peri-implant bone formation (nbfr) was calculated using the following formula: (16) nbfr = x 100 results clinical observation all rabbits showed normal movement after one week which indicates that the rabbits tolerated the implantation, there was no sign of gross infection, tissue reaction. screws could not be moved with manual force. histological observations the histological feature of the implants coated with hydroxyapatite in rabbit tibia after two weeks of implantation showed osteoid tissue with numerous bone cell around with numerous new capillaries formation as shown in figure 2. figure 2: microscopic photograph view of coated implant in rabbit tibia after two weeks of implantation , shows osteoid tissue with numerous bone cell around, (h&e stain) x10. histological findings in the section of the tibia bone adjacent to the implanted cp ti screws coated with srcl2 after 2 weeks of implantation shows new bone trabeculae lined by osteoblast cell, osteoblast arranged as a rim of cells on the bone surface and active osteoid tissue as shown in figure 3. figure 3: high magnification view of implant coated with srcl2 in rabbit tibia for two weeks duration shows new bone trabeculae (bt), lined by osteoblast cell (obc).note active osteoid tissue (aot) formation around, h&e x10. after 6 weeks, microscopic views showed new bone formation with osteocyte cells. other higher magnification showed osteocyte cell irregularly distributed in thick trabeculae and a large number of osteoblast (figures 4). figure 4: microscopic photograph view for the ha coated ti implant after 6 weeks of implantation shows new bone formation, osteocyte cell (occ) and thick bone trabeculae. h&e x10. figure 5: microscopic photograph view for thesrcl2 coated ti implant after 6 weeks of implantation shows new bone formation, numerous osteocyte cell (occ) and thick bone trabeculae. h&e x10. j bagh college dentistry vol. 27(1), march 2015 histological and restorative dentistry 29 after 6 weeks of implantation, microscopic views for the section of the rabbit tibia bones surrounding the cp ti implant coated with srcl2 showed active process of bone development, indicated by the active and large numbers of osteocyte cell clearly appeared (figure 5). higher magnification view showed clearly osteocyte cell, also reversal line (figure 6) figure 6: microphotograph view for the old bone and new bone with reversal line around implant coated with srcl2 after 6 weeks of implantation. h&e x20. histomorphometric analysis effect of strontium chloride coating at 2 weeks. there was significantly increased new bone formation ratio for srcl2 coated implants than ha coated implants as seen in table 2 the mean value for ha and srcl2 after 2 weeks ( .9898 % ± .49161 and 1.3427 % ± .37322 ) respectively (figure 7) figure 7: nbfr value of srcl2 coated implants and ha coated implants at 2 weeks interval. effect of strontium chloride coating at 6weeks the strontium coated implants recorded a higher mean of new bone formation ratio than ha coated implants as seen in table 2mean value for srcl2 coated implants after 6 weeks of 1.44 % ± .571, while for ha1.419 % ± .565 (figure 8). figure 8: nbfr of srcl2 coated implants and ha coated implants at 6 weeks interval. effect of time on removal torque value both coating materials showed increased new bone formation ratio between 2 and 6 weeks of implantation (table 2). figure 9: the summary of the differences in the nbfr mean values between all groups. table 2: t –test for equality of means of nbfr for srcl2 and ha coated implants at 2 and 6 weeks intervals. sig. p-value df t-test time types s 0.017 29 2.522 2 weeks x 6weeks ha ns 0.513 29 0.662 2 weeks x 6weeks srcl2 discusion the rabbit is convenient for the study because it reaches skeletal maturity shortly after sexual maturity around 6 months of age. the physiology of rabbit cortical bone is accelerated when compared with human beings, rapid cortical bone remodeling allows for evaluation of osseointegration of dental implants as early as 6 weeks compared with 18 weeks in human. (17) the age of the present animals that used in this study was from 10-12 months thus assuring complete nbfr value % nbfr value % nbfr value % j bagh college dentistry vol. 27(1), march 2015 histological and restorative dentistry 30 closure of proximal tibial epiphysis, as stated by pearce et al. (18) the tibial sites in rabbit were chosen to mimic the clinical situation, since the dimension of this bone corresponds well with human alveolar space. surgically this model provides low morbidity with easy access to the medial proximal tibia for implant placement. effect of strontium chloride coating after 2 weeks of implantation implants coated with srcl2 were shown to have a significantly larger bone area than the ha coated implants, which could be attributed to different mechanism of action. this was evidenced by the higher number of osteoblast and more bone trabecule and active ostiod than ha. ellis and kathleen explained the mechanism of action of sr by enhancing replication of preosteoblastic cells by increased alkaline phosphatase activity. (19) effect of strontium chloride coating after 6 weeks of implantation bone formation ratio at 6 weeks was slightly higher in sr than ha coated implants, 1.441, 1.419 respectively. however, the histological feature clearly showed the differences between them. more osteoblasts were seen which indicated the continuous bone formation, more osteocyte cells which reflected the higher maturation of the bone and more transformation of ostoblast to osteocyte in sr section than in ha section. reversal lines were also seen in sections of sr implant sections while it was not seen in section of ha implant sections. the approximation of ratio of sr to ha may be due to decreasing amount of sr from surface of implant due to high solubility of sr (53.8 g/100 ml) , moreover; amount of sr coated on the implant was used compared to the ordinary dose of the drug administered to the osteoporotic patient (800 mg /kg /day .(20) the increased formation in the new bone for ha from 2 to 6 weeks might be due to delay activation of ha to osteoblast. al-duliamy used (900 mg /kg /day) injection of srcl2 locally in palate for stabilization of expansion of rat palate after orthodontic treatment. (21) effect of time on nbfr both sr and ha coatings showed increased ratio of bone formed by time. ha coating showed significantly increased ratio of bone formation from 2 weeks to 6 weeks (0.98 % and 1.41% respectively) which indicated delayed activation of ha to form new bone which was reflected by more bone formation at 6 than at 2 weeks sr coating showed non significant difference in the ratio of new bone formed as it was 1.34 % at 2 week and became 1.44 % at 6 weeks. this might indicate relatively constant activation of sr to osteoblast through out the time period. as conclusion; there was significantly higher new bone formation ratio of srcl2 coated cpti implants than ha coated cpti implant at 2 weeks healing period, also there was increased new bone formation ratio with time for both coating materials (ha and srcl2 ) implants . references 1. susin c, qahash m, polimeni g, lu ph, prasad hs, rohrer md. alveolar ridge augmentation using implants coated with recombinant human bone morphogenetic protein-7 (rhbmp-7/rhop-1): histological observations. j clin periodontol 2010; 37: 574–81. 2. le guéhennec, soueidan a, layrolle p, amouriq y. surface treatments of titanium dental implants for rapid osseointegration. dent mater 2007; 23(7): 84454. 3. jokstad a, braegger urs, brunski jb, carr ab, naert l, wennerber a. quality of dental implants. int j prosth. 2004; 17:607-641. 4. chaiy r, qing li, wei li, appleyard r, swain m. effect of fully porouscoated (fpc) technique on osseointegration of dental implants. adv mater res. 2008; 32:189-192. (ivsl). 5. branemark pi. the branemark novum protocol for same-day teeth. a global perspective. chicago: quintessence; 2001. p. 9-29. 6. blake gm, fogelman i. strontium ranelate: a novel treatment for postmenopausal osteoporosis: a review of safety and efficacy. clin interv aging 2006; 1(4):367-75. 7. pors nielsen s. the biological role of strontium. bone. 2004; 35(3): 583-8. 8. morohashi t, sano t, harai k, yamada s. effects of strontium on calcium metabolism in rats. ii. strontium prevents the increased rate of bone turnover inovariectomized rats. jpn j pharmacol 1995; 68(2):153-9. 9. boivin g, meunier pj. the mineralization of bone tissue: a forgotten dimension in osteoporosis research. osteoporos int. 2003; 14 suppl 3: s19-24. 10. meredith n. on the clinical measurement of implant stability and osseointegration, a phd thesis. sweden: department of biomaterials, university of go¨teborg, 1997:1–209. 11. atsumi m, park s, wang h. methods used to assess implant stability: current status. int j oral maxillofac implant 2007; 22(5): 743-54. 12. jani gh. torque removal test of strontium chloride and hydroxyapatite coated commercially pure titantium implant complemented with histomorphometric analysis (a comparative study). a master thesis, college of dentistry, university of baghdad, 2014. j bagh college dentistry vol. 27(1), march 2015 histological and restorative dentistry 31 13. hamad ti. histological and mechanical evaluation of electrophoretic bioceramic deposition on ti6al 7nb dental implants, a ph.d. thesis, college of dentistry, university of baghdad, 2007. 14. bhaskar sn. orban’s oral histology and embryology.11th ed. usa: mosby, 1991. 15. shapiro f. bone development and its relation to fracture repair. the role of mesenchymal osteoblasts and surface osteoblasts. eur cell mater 2008;15:53-76 16. baek sm, kim sg, lim sc. histomorphometric evaluation of new bone formation around a magnetic implant in dogs. implan 2011:15(1): 22-30. (ivsl). 17. michaels oc, carr ab, larsen pe. effect of prosthetic superstructure accuracy on the osseointegrated implant bone interface. oral surg oral med oral path 1997; 83(2):198-205. 18. pearce a, richards arg, milz s, schneider e, pearce sg. animals models for implantation biomaterial research in bone: a review. euro cells mater 2007; 13:1-10. 19. ellis e. golub and kathleen boesze-battaglia. the role of alkaline phosphatase in mineralization. curr opin orthop 2007; 18: 444–8. 20. ammann p, shen v, robin b, mauras y, bonjour jp, rizzoli r. strontium ranelate improves bone resistance by increasing bone mass and improving architecture in intact female rats. j bone miner res 2004; 19: 2012–20. 21. al-duliamy m. the effect of orthodontic relapse on the proliferation of fibroblast and epithelial rests of malassez in periodontal ligament of rat molars (a histopathological study). a master thesis, collage of dentistry, university of baghdad, 2011 الخالصة النجاح في زرع األسنان یعتمد على عدة .الخالیة من اسنان في السنوات األخیرة، أصبح تحمیل الفوري لزراعة األسنان أكثربروتوكول قبوال للعالج منطقة: مقدمة راسة ھو تقییم تأثیر طالء كلورید السترونتیوم وكان الھدف من الداتالتي قد تحسن ظاھرة االندماج العظمي و تكوین عظام جدیدة على اتصال وثیق مع الزرععوامل تھا مع طالء لغرسات االسنان المصنوعة من التیتانیوم النقي التجاري على االندماج العظمي لغرسات في العظم عن طریق تحلیل القیاس النسیجي ومقارن .)أسابیع 6أسابیع و 2( ھیدروكسیباتیت في فترات زمنیة للحصول على طبقة طالء موحد على زرعات االسنان المصنوعة من التیتانیوم النقي تجاریا ( epd ) م استخدام تقنیة الترسیب الكھربيت: المواد و طرق العمل و احدة مطلیة كل من الساق أرنب تلقى اثنین من البراغي ، واحدة مطلیة بكلورید السترونتیوم . األبیض أرانب نیوزیلندا كمواقع زرع 4وقد تم اختیار الساق من تم إجراء تحلیل القیاس النسیجي لقیاس نسبة العظم .المقاطع النسیجیة لكل مواد الطالء في كل فترة من الزمن 30بھیدروكسیباتیت وتم الحصول على ما مجموعھ أسابیع من فترات الشفاء 6و 2الجدیدة المتكون بین الزرع و العظام األصلیة، بعد كانت ھناك زیادة .الفترتین من الزمن بھیدروكسیباتیت خاللبكلورید السترونتیوم اكثر كفاءة بزیادة تكوین العظم من الغرسات المطلیة الغرسات المطلیة :النتائج. .في نسبة تكوین العظم في منطقة التقاء العظم والغرسة مع مرور الوقت في في منطقة التقاء العظم والغرسة من ھیدروكسیباتیت ، االندماج العظمي السترونتیوم أكثر كفاءة في زیادة كان طالء التیتانیوم النقي تجاري بكلورید.:االستنتاج .أسابیع بعد الزرع 6أسابیع و 2في الفترتین " الذي یتضح من تكوین العظام الجدیدة أعلى نسبة واكثر نضجا sami final.doc j bagh college dentistry vol. 26(2), june 2014 dental arches dimensions orthodontics, pedodontics and preventive dentistry 160 dental arches dimensions, forms and its association to facial types in a sample of iraqi adults with skeletal and dental class ii-division 1 and class iii malocclusion (a cross sectional study) hanadi m. h. al-taee, b.d.s. (1) sami k. al-joubori, b.d.s., m.sc. (2) abstract background: the association between facial types and dental arches forms has considerable implications in orthodontic diagnosis and treatment planning. the aim was to establish the maxillary and mandibular dental arches width and length in skeletal and dental class ii division 1 and class iii malocclusion groups, find out the most frequent dental arch form and facial type and the association between them and to check the gender differences. materials and methods: frontal and lateral facial photographs and maxillary and mandibular occlussal photographs for 90 iraqi subjects with age 18-25 years old (45 males and 45 females) divided equally into three groups, the 1st group with class ii division 1malocclusion (overjet more than 3mm but less than or equal to 6mm), the 2nd group with class ii division 1malocclusion (overjet more than 6mm) while the 3rd group with class iii malocclusion (edge to edge or reverse overjet).six linear measurements for each maxillary and mandibular dental cast photographs and two liner measurements for frontal and profile facial photographs was analyzed with (auto cad 2013), which simplified the analyzing process and reduced the time and effort spent on taking measurements directly from the records to facilitate work and to gain more accurate results. results: all the mean value of dental arches and facial measurements were higher in male than female, the most frequent maxillary and mandibular dental arch form in the three groups was the mid arch form follow by the narrow then the wide arch form except in the mandibular dental arch of the 3rd group it follow by the wide then the narrow arch form.the most frequent facial type in the 1st group is the mesoprosopic one,followed by the leptoprosopic then the euryprosopic face type while in the 2nd and 3rd group the most frequent facial type is the leptoprosopic, follow by the mesoprosopic then the euryprosopic facial type. an association was found between mid arch form and the mesoprosopic face type in the 1st group, while no clear association was found between dental arch form and facial type in the 2nd and 3rd group for both genders. conclusions: it was concluded that there was an association between facial type and dental arch form in subject with class ii division 1malocclusion (overjet not more than 6mm), while in subject with class ii division 1malocclusion (overjet more than 6mm) or with class iii malocclusion (edge to edge or reverse overjet) no clear association was found between dental arch form and facial type. key words: facial types, dental arch forms, association, class ii division 1malocclusion and class iii malocclusion. (j bagh coll dentistry 2014; 26(2): 160-166). introduction knowledge of the standards for the dental arch dimensions in human population is of great value to clinicians in different fields of dentistry and they are of great interest to anthropologists in studying the dental arch growth and development in relation to different environmental, genetic and physical factors for different population (1,2). in orthodontics, it is important that the arch form is observed before the treatment is started as the post treatment occlusal stability depends on preservation of the original arch from(3).facial harmony regard as one of the main characteristics of beauty (4). it is the unity of diversity, characterized by good function and good form. this harmony is primarily determined by the soft tissue integument, along with the underlying skeletal framework (5,6). there is a sort of correlation between facial morphology and dental arch form, severe malocclusion is often accompa (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad. nied by disproportion of the face and jaws, when this occurs, the problems are commonly referred to as dentofacial deformities, however, malocclusion should not be thought of as a pathologic condition but merely as human morphologic variation (7). the aim was to establish the maxillary and mandibular dental arches width and length in skeletal and dental class ii division 1 and class iii malocclusion groups, find out the most frequent dental arch form and facial type and the association between them and to check the gender differences. materials and methods sample the sample was selected from baghdad university, college of dentistry. in order to get our sample (90 subjects divided equally into males and females), a total of 334 iraqi adult subjects were clinically examined (180 female, 154 male). the samplewas divided intothree equal groups: j bagh college dentistry vol. 26(2), june 2014 dental arches dimensions orthodontics, pedodontics and preventive dentistry 161 the 1st group included 30 subjects has skeletal class ii and dental class ii division 1 malocclusion (15 males and 15 females) with increased overjet (more than 3 but less than or equal to 6 mm) (8). the 2nd groupincluded 30 subjects has skeletal class ii and dental class ii division 1 malocclusion (15 males and 15 females) with extreme ovejet (more than 6 mm)(8). the 3rd group included 30 subjects has skeletal and dental class iii malocclusion (15 males and 15 females) with 0 or –ve overjet (9). the criteria of sample selection general criteria: all the sample was iraqi subjects their age 18 25 years old have full permanent teeth excluding the third molars (10, 11). free of local factors that disturb the integrity of the dental arches (congenital missing teeth; retained deciduous; supernumerary teeth). no crown and bridge prosthesis, large dental fillings or minor spacing or crowding were present (12).no history of bad oral habits. no posterior cross bite. no dental anomalies. no previous orthodontic, orthopedic, or facial surgical treatments.no anterior or posterior open bite. specific criteria for the 1st and 2nd groups (8): skeletal class ii, diagnosed clinically by using the two fingers technique (13), bilateral dental class ii (molar and canine relationships)(14)with over jet more than (3 mm)(13). specific criteria for the 3rd group (9) skeletal class iii relationship, diagnosed clinically by using the two fingers technique (13), bilateral dental class iii (molar and canine relationships) (14), with zero or reverse over jet (13). methods standardization of the facial photographs the camera was fixed in position andadjusted in height to be at the level of subject 'eyes in the frontal photograph with a heightadjustable tripod. the distance from the digital camera (sony cyber shot h 50, 9.1 mega pixels, 15 x optical zoom, sony corporation, nagoya, japan) to the subject was fixed at a distance of about 101cm. measured from the lens of camera to the ear rodsthat were fit in the external auditory meatus inorder to avoid the forward, backward, and tiltingof the subject head (cephalostate based headposition). the subject was asked to look to thecenter of the lens of the camera in the frontalphotograph and to look at a distant mirror whichis placed in front of his/her face in the lateral photograph with ear rods in the external auditorymeatus (16). facial landmarks: (figure 1) 1. nasion (n) the point in the midline of both the nasal root and the nasofrontal suture, always above the line that connects the two inner canthi, identical to bone nasion (17). 2. gnathion (gn): the soft tissue point corresponding to skeletal gnathion (7) which is the most anterior and inferior point of the soft tissue chin (18). 3. zygoin (zyg): the most prominent point on the cheek area beneath the outer canthus and slightly medial the vertical line passing through it; different from bony zygoin (17). linear measurements 1. inter-zygomatic distance (izd): it is the transverse distance between soft tissue zygion on both sides (19). 2. anterior facial height (n-gn): it is the distance between soft tissue nasion and soft tissue gnathion (20). facial types facial form was determined using farkas and munro (21) method by calculating the ratio betweeninter-zygomatic distance and anterior facial height,and then the face type for each subject isclassified as follows: • euryprosopic facial type. the facial index(izd/n-gn) is > 0.93. • mesoprosopic facial type. the facial index (izd/n-gn) is ≤0.93 and ≥0.83. • leptoprosopic facial type. the facial index (izd/n-gn) is<0.83. standardization of the dental casts photographs: after taking the proper impression for the maxillary and mandibular arches and preparing the casts, a photograph was taking to each dental cast using special apparatus (15). dental cast landmarks (figure.2) 1. incisal point: the point in the midwaybetween the incisal edges of the two centralincisors (22). 2. canine point: the cusp tip of the right and left permanent canines (23). 3. mesiobuccal cusp tip of the first molars: themesiobuccal cusp tips of the right and left firstpermanent molars (24). 4. distobuccal cusp tip of second molars: thedistobuccal cusp tips of the right and left second permanent molars (20). j bagh college dentistry vol. 26(2), june 2014 dental arches dimensions orthodontics, pedodontics and preventive dentistry 162 dental arch width: 1. the inter canine distance (icd): the lineardistance from cusp tip of one canine to thecusp tip of the other (20). 2. inter first molar distance (imd): the linear distance from the mesiobuccal cusp tip of onefirst permanent molar, to the mesiobuccal cusptip of the other (25). 3. inter-second molar distance (i2ndmd): the linear distance between the distobuccal cusptip of one second permanent molar, to thedistobuccal cusp tip of the other (20). dental arch length: 1. canine vertical distance(cvd): the verticaldistance from the incisal point perpendicular toa line joining the inter-canine distance at thecusp tips (22). 2. molar vertical distance (mvd): the vertical distance from the incisal point perpendicular toa line joining the mesiobuccal cusp tips of firstpermanent molars (20). 3. total arch length (tal): the inter– incisal point to the mid distance of the maxillary andmandibular inter – second molar width at the mesiobuccal cusp (26). arch form (27) six dental cast’s measurements were divided into three sagittal measurements, and three transversemeasurements were utilized to calculate threeindependent ratios, which are: 1. canine vertical distance / inter-caninedistance. 2. molar vertical distance / inter-first molardistance. 3. total arch length / inter-second molardistance. the standardize number was calculated for eachof three ratios for each subject by the excelprogram. then the mean of these standardizednumbers was calculated for each subject whichgave the base for classification as follows: 1. narrow form the mean of standardizednumber >+1. 2. mid form the mean of standardized numberbetween (+1 and -1). 3. wide the mean of standardized number <-1. statistical analysis: all the data of the sample were subjected tocomputerized statistical analysis using spssversion 17for windows xp. the statistical analysis included: a. descriptive statistics means, standard deviations, minimum and maximum values, frequency, percentage and statistical table and figures. b. inferential statistics 1. independent sample t-test: to compare between genders regarding dental archesand facial dimensions. 2. chi square test: to test gender difference regarding the dental arch form and facial form. likelihood ratio: it is an alternative to chi square used in case of table with more than 2*2 when the expected frequency less than 1 in any cell or when it is less than 5 in 20% of the cells. 3. one way analysis of variance (anova): to compare the dental arches and facialmeasurements among the three groups in each gender and total sample. 4. least significant difference (lsd): test was preformed when (anova) testshowed a statistical significant difference, to assess any statistical significantdifference between each pairs of groups. in the statistical evaluation, the following levels of significance are used: non-significant ns p > 0.05 significant * 0.05 ≥p > 0.01 results and disscussion descriptive statistics of dental arches with comparison of dental arch dimensions between both genders in each group. all of the widths and lengths measurements havegreater mean value in male than females but the difference is not significant in the 1stand 2nd group, while in the 3rd group significantdifference was found inmaxillary and mandibularinter molar distance(imd), mandibularinter second molar distance (i2nd md), mandibular canine vertical distance (cvd), maxillary molar vertical distance (mvd) and maxillary and mandibular total arch length (tal).that may be due to:the smaller and smoother bony ridge and alveolar process of females (28) , the average weakness of musculature infemales that play an important role in widthand height of dental arch (28)andlonger growth period for males than females (29). mean values and groups’ difference for maxillary and mandibular dental arches dimensions in both genders.(figure. 3) -the maxillary dental arch all the width measurement show significant differencebetween the 1st and 3rd group and between the 2nd and 3rd group (the 3rd group show higher mean value than 1st and 2nd group), while the non-significant difference was between the 1st and 2nd group.that’s mean that the 3rdgroup has a wider maxillary dental arch as j bagh college dentistry vol. 26(2), june 2014 dental arches dimensions orthodontics, pedodontics and preventive dentistry 163 compare to the 1st and 2nd group which may be due to restricted width growth in themaxillary dental arch in subject with class ii malocclusion (30, 31). in the length measurement, we notice that, the canine vertical distance(cvd) and total arch length(tal) show significant difference between the 1st and 3rd group and between the 2nd and 3rd group (1st and 2nd group show higher mean value than the 3rd group), while the nonsignificant difference was between the 1st and 2nd group, that’s mean that the 2nd group has longer maxillary dental arch length as compare to the 1st and 3rd group, which is an expected result, considering the proclination of the maxillary central incisors in class ii division 1 comparedwith other type of malocclusion. -the mandibular dental arch all the mean value of the width and length measurements of the 3rd group was larger than that of the 1st and 2nd group with significant difference, which mean that the 3rd group has wider and longer mandibular dental arch as compare to the 1st and 2nd group, this can be attributed to the increased growth potential of mandible in class iii patients (30,32,33) arch form. (figure. 4) a. distribution of the three forms of maxillary dental arch in males, females and the total sample and gender difference. in the three groups, no significant difference was found, in distribution of the three forms of maxillary dental arch between males and females for each group (34).the most frequent maxillary dental arch form for male, female and totalsample in the 1st and 3rd group is the mid arch formfollowed by narrow then the wide arch form, while in the 2nd group the most frequent maxillary dental arch form is the mid arch form followed by narrow and there is no incidence for the wide dental arch form (35). b. distribution of the three forms of mandibular dental arch in male, females and the total sample and gender difference. in the 1st group, significant difference was found in distribution of the three forms of mandibular dental arch between males and females, while in the 2nd and 3rd groups, no significant difference was found.the most frequent mandibular dental arch form for the total sample in the 1stand 2nd group is the mid arch form followed bynarrow then the wide arch, while in the 3rd group the most frequent mandibular dental arch form is the mid arch form followed bythe widethen narrow arch form (36). mean values and groups’ difference for facial measurements for both genders. there was non-significant difference among the three groups in the facial width (interzygomatic distance) , while in facial length (nasion–gnathion distance) we found that there was significant difference between the 1st and 2ndgroup and between the 1st and 3rdgroup, while non-significant difference was found between the 2nd and 3rdgroup, which may be due to that the regional feature that produce long face in cl iii was the mandibular protrusion, while in class ii was the narrowing and elongation in the nasal region (37). the most predominant type of the face in the males, females and total sample, of the 1st, 2nd and 3rd group.(figure. 5) nonsignificant difference was found in distribution of the three facial types between males and females within the 1st, 2nd and 3rd group. the most frequent facial type in the total sample is the mesoprosopic one, followed by the leptoprosopic while the least frequent is the euryprosopicface type in the 1st group, while in the 2nd and 3rd group the most frequentfacial type is the leptoprosopic one, followed by the mesoprosopic while theleast frequent is the euryprosopic face type (8, 37). association between the facial type and dental arch forms described as frequency and percentage for each group. this study is one of the least researches that have studied the facial dimensions of the face from a photograph, and its association with the maxillary and mandibular dental arch form in cl ii div 1 and cl iii angle classification of malocclusion. therefore, there is a very little information to make a comparison between this study and other studies.in the 1st group there was an association between the mid arch form and themesoprosopic facial type in maxillary dental arch of both gender and themandibular dental arch in female, while no clear association was foundbetween mandibular dental arch form and facial form in male. in the 2nd and 3rd group no clear association was found between coordinatedental arch form(mid, narrow and wide) and facial type (mesoprosopic,leptoprosopic and europrosopic). j bagh college dentistry vol. 26(2), june 2014 dental arches dimensions orthodontics, pedodontics and preventive dentistry 164 figure 1: facial land marks figure 2: dental cast land marks and linear measurements figure 3: mean values and groups’ difference for dental arches dimensions figure 4: distribution of the three forms of maxillary and mandibular dental arch in males, females and the total sample and gender difference. zygion nasion gnathion j bagh college dentistry vol. 26(2), june 2014 dental arches dimensions orthodontics, pedodontics and preventive dentistry 165 figure 5: the most prominent facial type in the males, females and total sample of 1st, 2nd and 3rd group references 1. younes sa. maxillary arch dimensions in saudi: and egyptian population sample am j orthod dentofac orthop 1984; 85:83-7. 2. diwan r, elahi jm. a comparative study between three ethnic groups to derive some standards for maxillary arch dimensions. j oral rehabil 1990; 17:438. 3. slaja m, spaljb s, pavlinc d. dental arch forms in dentoalveolar class i, ii and iii. angle orthod 2010; 80: 919-24. 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(ivsl) 7. graber tm, swain bf. orthodontics current principles and techniques. 2nd ed. st. louis: the c.v. mosby co.; 1994. 8. saltaji h, flores-mir c, major pw, youssef m. the relationship between vertical facial morphology and overjet in untreated class ii subject. angle orthod 2012; 82(3):432-40. 9. alkhawaja nfk. alveolar base and dental arch widths with segmental arch measurements in different classes of malocclusions. a master thesis, college of dentistry, baghdad university, 2010. 10. bishara se. textbook of orthodontics. 1st ed. philadelphia: w.b. saunders company; 2001. 11. swierernga d, oeserle lj, messersmith ml. cephalometric values for adults mexican. am j orthod dentofac orthop 1994; 106 (2): 146-55. 12. bjork a. a method for epidemiological registration of malocclusion. acta odonto scand 1964; 22: 27-41. 13. foster td. a text book of orthodontics. 3rd ed. london: blackwell scientific publication; 1990. p. 4, 17. 14. angle eh. classification of malocclusion. dent cosmos 1899; 41(4): 248-64. 15. saadi z. the effect of nutritional status on dental health, salivary physicochemical characteristics and odontometric measurements among five years old kindergarten children and fifteen years old students. ph.d. thesis, college of dentistry, baghdad university, 2010. 16. al-ramahi sc. evaluation of buccal corridor in posed smile for iraqi adults sample with class i normal occlusion. master thesis, college of dentistry, baghdad university, 2009. 17. farkas lg. anthropometry of the head and face. 2nd ed. new york: raven press; 1994. p. 20–26. 18. rakosi t. an atlas and manual of cephalometric radiography. london: wolfe medical publications ltd; 1982. p. 35-45, 62-66. 19. bishara se, jacobsen jr, jorgensen gj. changes in facial dimensions. am j orthod dentofac orthop 1995; 108: 389-93. 20. ramadan oz. relation between photographic facial measurements and lower dental arch measurement in adult jordanian males with class i normal occlusion. master thesis, college of dentistry, mosul university, 2000. 21. farkas lg munro ir. anthropometric facial proportion in medicine. charles thomas; 1987. p. 3,4. 22. al-sarraf ha. maxillary and mandibular dental arch dimensions in children aged 12-15 years with class i normal occlusion "cross sectional study". master thesis, college of dentistry, mosul university, 1996. 23. staley rn, stuntz wr, peterson l. a comparison of arch widths in adults with normal occlusion and adults with class ii division 1 occlusion. am j orthod dentofac orthop 1985; 88:163-9. 24. kuntz tr. an anthropometric comparison of cephalometric and dental arch measurements in classes i normal, class i crowded and class iii individuals. master thesis, university of iowa, 1993. 25. bishara se, treder je, damom p, olsen m. changes in the dental arches and dentition between 25 and 45 years of age. angle orthod 1997; 66:417-422. 26. borgan be. dental arch dimensions analysis among jordanian school children. master thesis. cairo university, 2001. 27. jassim ja. association between upper dental arch dimensions and facial type in adult with class i normal occlusion. a computerized study. master thesis, college of dentistry, mosul university, 2010. 28. brodie ap. the growth pattern of the human head from the third month to the eighth year of life. am j orthod 1941; 68: 209-62. 29. genecov, js, sinclair pm and dechow pc. development of the nose and soft tissue profile. angle orthod 1990; 60(3): 191-8 30. al-khateeb sn, abu alhaija esj. tooth size discrepancies and arch parameters among different malocclusions in a jordanian sample. angle orthod 2006; 76(3): 45965. 31. lux cj, conradt c, burden d, komposch g. dental arch widths and mandibular-maxillary base widths in class ii malocclusions between early mixed and permanent dentitions. angle orthod 2003; 73: 674–85. 32. mitani h, sato k, sugawara j. growth of mandibular prognathism after pubertal growth peak. am j orthod dentofac orthop 1993 104: 330–6 j bagh college dentistry vol. 26(2), june 2014 dental arches dimensions orthodontics, pedodontics and preventive dentistry 166 33. yoo yk, kim ni, lee hk. a study on the prevalence of malocclusion in 2378 yonsei university students. korean j orthod 1971; 2: 35–40 34. ferrario v, sforza c, miani a, tartaglia g. mathematical definition of the shape of the dental arches in human permanent healthy dentitions. eur j orthod 1993; 16(4): 287-94. 35. martina s, stjepan s, dubravko p, davor l, mladen s. dental arch forms in dentoalveolar class i, ii and iii. angle orthod 2010; 80: 919-24. 36. murshid za. the pattern of malocclusion among a sample of saudi orthodontic patient in jeddah. egyp orthod j 2008. 37. martone vd, enlow dh, hans mg, broadbent h, oyen o. class i and class iii malocclusion subgrouping related to the head form type. angle orthod 1992; 62(1): 35-42. amjed final.doc j bagh college dentistry vol. 26(2), june 2014 socioeconomic status orthodontics, pedodontics and preventive dentistry 131 socioeconomic status in relation to dental caries in dewanyiah governorate among 12 years old school students amjed k. al-hassnawi, b.d.s. (1) athraa m. al-waheb, b.d.s., m.sc. (2) abstract background: the socioeconomic is important factor that effect in the severity and prevalence of most predominant and wide spread oral disease named dental caries, since this oral disease effects children, adolescents, adults and elderly peoples especially in developing countries as in iraq.this survey was aimed to investigate the prevalence and severity of dental caries in relation to socioeconomic status. materials and methods: this oral health survey was conducted among primary and secondary school students aged 12 years old in dewanyiah governorate in iraq. the total sample composed of 804 (401 boys and 403 girls) selected randomly from different schools in dewanyiah governorate. diagnosis and recording of dental caries was assessed according to the criteria described by who (1997).the modification of kuppuswamy's index (1976) was applied for measurement of socioeconomic status. results: the most of low socioeconomic category was occupied by rural students. the prevalence of dental caries was 70.65 % for the total sample. the mean dmft was equal to (1.83 ± 0.068) and dmfs (2.89 ± 0.126). no significant difference was seen between socioeconomic status and dmfs. conclusion: a high prevalence of dental caries was recorded. socioeconomic status may affect dental caries indicating the need for public and health preventive programs among school students. key words: dental caries, socioeconomic status, prevalence. (j bagh coll dentistry 2014; 26(2): 131-134). الخالصھ ا انتشارا المسماة بتسوس االسنان طالما ھذا الحالة االجتماعیة االقتصادیة من العوامل المھمة التي تؤثر على شدة وانتشار ابرز االمراض الفمویة واوسعھ:المقدمة البحث المیداني ھدف الى تشخیص نسبة وانتشار تسوس .البالغین و المسنین خصوصا في البلدان النامیة كالعراق, المراھقین ,المرض الفموي یصیب االطفال .بالوضع االجتماعي االقتصادي تھاالسنان وعالق طالب 804العینة الكلیة تكونت من . سنة في محافظة الدیوانیة 12تم ما بین طالب المدارس االبتدائیة والمتوسطة بعمر البحث المیداني : المواد والطرق تشخیص تسوس االسنان تم وفق مقاییس منظمة الصحة العالمیة .تم اختیارھم عشوائیا من مختلف مدارس محافظة الدیوانیة) بنین 401بنات و403( )(who,1997 .لوضع االجتماعي االقتصادي تم باستخدام تعدیل لمقیاس تشخیص ا)kuppuswamy's, 1976.( كما اظھرت الدراسة ان نسبة تسوس االسنان .اظھرت الدراسة ان نسبة الطالب الذین ینتمون للفئة االجتماعیة المتدنیة كانت ضمن فئة المناطق الریفیة : النتائج ±2.89(مساوي الى dmfsبینما ) 0.068 ±1.83( مساوي الى dmftالدائمةالمتوسط الحسابي لتسوس االسنان كانت قیمة %). 70.65(للعینة كلھا كانت . dmfsمع االجتماعي االقتصاديالوضع لم توجد فروقات معنویة بین ).0.126 ؤثر على صحة الفم مما یشیر الى حاجة طالب المدارس ید الوضع االجتماعي االقتصادي ق. لقد وجدت الدراسة ان نسبة تسوس االسنان كانت عالیة : االستنتاجات .لبرامج وقائیة عامة لتعزیز صحة الفم introduction socioeconomic is an important determinant of the livelihoods as it influences levels of knowledge, skill and income conditions which mean for their living. socioeconomic status is an economic and sociological combined total measure of a person’s work experience and of family’s economic and social position relative to others based on income, education and occupation. socioeconomic status is typically broken into three categories, high ses, middle ses and low ses to describe the three areas of families (1). dental caries continues to be one of the most common infectious diseases known to man, despite widespread preventive measure, this disease exerts a social, physical, mental and financial burden on a global scale especially in developing countries (2). (1)master student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2)professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad the disease is a chronic irreversible progressive in nature, untreated lesions may progress to cause pain, infection and discomfort to the subject, and finally it might end with the loss of the tooth (3). as far as it is known, there is no previous epidemiological study concerning students aged 12 years old in dewanyiah governorate, in order to increase the knowledge concerning oral health status of this age group. this in turn may focus some light on the availability and effectiveness of preventive programs and dental services among this population. materials and methods permission was obtained from the general direction of education of dewanyiah governorate to conduct the survey without obstacles. it was conducted among primary and secondary school students aged 12 years old. the age was taken according to the criteria of world health organization (1997), according to the last birth day. the number of 12 year school students living j bagh college dentistry vol. 26(2), june 2014 socioeconomic status orthodontics, pedodontics and preventive dentistry 132 in dewanyiah city was (12462) as the general direction of education of dewanyiah governorate was labeled in both rural and urban areas. the examination done for about (812) students and (8) was neglected because incomplete information so the representative sample was calculated to be 804 school students whom selected randomly, 403 girls and 401 boys. schools selection was randomly as they were distributed in different geographical areas in dewanyiah governorate (urban and rural). also for each school students were selected randomly. a random sample of a maximum of 20 students (10 from each gender) was included in the sample. students who looked healthy and without any medical disease were only examined. dewanyiah city was divided into four sectors each sector contained rural and urban schools according to the division of the general direction of education of dewanyiah governorate, these sectors are: aldewanyiah center, al-hamza, al-shamiyah and efaq. socio economic status assessment ses informationwas taken from the examined students and from their own school document as follow: • mother and father education level. • mother and father occupation. • type of housing. • crowding index ( persons number/ rooms number) according to the quartile categorization, the sample was divided to three quarters 25%, 50% and 25%, representative low, average or middle and high socioeconomic status respectively. the cut of value for the composite index used by this research was as the following: • score 1 for students with low socioeconomic status (≤10.5). • score 2 for students with average socioeconomic status (10.6 15). • score 3 for students with high socioeconomic status (>15). dental caries diagnosis and registration of dental caries was conducted following the criteria of who (1997). the clinical examination was achieved by dental mouth mirror and (cpi) dental explorer. the clinical diagnosis of the dental caries was carried with starting from the upper right second molar in an organized serial manner from tooth to the adjacent tooth till reaching the upper left second molar, then to the lower left second molar until ending with the lower right molar. as concerned the examination of the tooth surfaces, it was done by starting with the mesial surface, then the occlusal, distal, buccal and ended with lingual for the examined teeth. if primary and permanent teeth occupied the same tooth space, the status of permanent tooth only was considered (4). dmfs index for all surfaces of the teeth involved carious lesions were recorded. missing teeth were counted as a five "involved surfaces" for posterior teeth and four for anterior teeth. retained roots were counted as a five decayed surfaces for posterior teeth and four decayed for anterior teeth. temporary crowns were recorded as 5 and 4 decayed surfaces for posterior and anterior teeth respectively. results the table (1) shows the low level of socioeconomic status students were higher in rural than urban while the high level of socioeconomic status students were higher in urban than rural areas. statistically, highly significant differences between socioeconomic status and residency with p value <0.001 was found. in relation to socioeconomic status, caries free was higher in low level followed by average and lastly high level that had higher caries experience than other socioeconomic status levels. statistically, no significant differences between caries free with socioeconomic status as shown in table (2). table (3) reveals the mean value and standard error of the caries experience of dmft, dmfs and its components (ds, ms, fs) for the total sample according to socioeconomic status. it was found that caries experience represented by dmft was higher among average level of socioeconomic students as compared with high and low level students and it was same for dmfs and ds. concerning the fs fraction, it was higher in high level students while, ms fraction was higher in low level students. no statistical significant differences were found. j bagh college dentistry vol. 26(2), june 2014 socioeconomic status orthodontics, pedodontics and preventive dentistry 133 table 1: the distribution of the sample by socio economic status and residency residency socioeconomic status p-value low average high no % no % no % rural 150 74.6 212 47.3 40 25.8 <0.001** urban 51 25.4 236 52.7 115 74.2 total 201 100 448 100 155 100 **highly significant table 2: the distribution of caries-free and caries experience in relation to socioeconomic status study sample caries experience caries free p-value no % no % se st at us low 129 64.1 72 35.8 [ns] average 323 72.1 125 27.9 high 116 74.8 39 25.2 table 3: mean value and standard error of ds, fs, ms, dmfs, dmft for total sample in relation to socioeconomic status caries experience socioeconomic status p-value low average high mean ± se mean ± se mean ± se ds 2.04±0.19 2.60±0.14 2.27±0.20 [ns] fs 0.04±0.02 0.08±0.02 0.10±0.03 [ns] ms 0.47±0.13 0.45±0.08 0.26±0.11 [ns] dmfs 2.55±0.26 3.13±0.17 2.63±0.24 [ns] dmft 1.56±0.13 1.96±0.09 1.84±0.15 [ns] discussion this study was achieved in dewanyiah governorate because there is no previous epidemiological study concerning the 12 years old students carried in this governorate. it was occupied all geographic locations including urban and rural areas and the size of total sample was (804) with approximately equal numbers for girls and boys as well as rural and urban students to be representative and comparative to these areas. the target study group was the age at which children leave primary school in most countries. it is also the last age at which reliable sample may be obtained easily through the school system. also, it is likely at this age that all permanent teeth except third molars have been erupted. for these reasons, 12 years old students had been chosen as the global monitoring age for caries for international comparisons and monitoring of disease trends (4). the current study applied a modification of kuppuswamy’s index 1976 for socioeconomic status. the index used in this study was based on variables such as educational level, occupation, crowding index and housing quality, while the income was not included because of difficulty of its estimation. the type of housing and occupation was classified in harmony with the nature of iraqi society and to represent as much as possible the income status, as there is no internationally endorsed ses index in iraq. in the present study, the rural was shown to have a lower ses while urban had the highest ses with highly significant differences between ses and area of residency. the rural students in the current study were selected from a demographically distinguished residential sector on the periphery of dewanyiah center and on the periphery of the large three other sectors. these students were socially and economically disadvantaged living in slums and agricultural areas (since their residence was considered as illegal). the educational level of those people was expected to be low, which does not help them in improving their economic level and changing residence to better urban areas. most of their fathers work as a former in agricultural areas and their mothers as housewife. polyandry was common with large number of people living in the same tiny house. many studies referred to rural areas are disadvantaged in ses when compared to urban areas, this observation is a general one in iraq (5). in the current study, caries free was higher in low level followed by average and lastly high level that had higher caries experience than other socioeconomic status levels although the association between ses and caries free failed to reach the level of statistical significance. this finding agreed with a case-control study in baghdad by al-eissa whom measured the j bagh college dentistry vol. 26(2), june 2014 socioeconomic status orthodontics, pedodontics and preventive dentistry 134 socioeconomic status by using crowding index and education in addition to other variables (6). these results are similar to findings of al-sadam whom measured the socioeconomic status by using housing type and education while excluded other variables (7). abdul razzaq found a positive correlation between ses and caries free (8). the ses index used in that study depended on education only and the explanation was that better education leads to increase caries free prevalence. in the current study, the type of housing, crowding index and occupation had an important contribution to ses measured. this might have explained the differences between this study and abdul-razzaq's finding. the ds, dmfs and dmft mean values were higher in average ses than other ses groups while ms mean value was higher in low ses that may due to poor knowledge about dental treatment. the fs mean value was slightly higher in high ses than other ses groups this was expected since the high ses students are more able to obtain quality dental treatment. this conclusion was also reported by above studies (68). references 1. rathod g, ningshen a. measuring the socioeconomic status of urban below poverty line families in imphal city, manipur; a livelihood study. int j of marketing, financial services and management research 2012; 12(1):2277-3622. 2. cameron a, widmer r. handbook of pediatric dentistry. 3rd ed. mosby elesvir; 2008. 3. caucified p, li y, dasanayake a. dental caries: an infectious and transmissible disease. compend contin educ dent 2005; 26(5):10-6. 4. who: oral health surveys, basic methods. 4th ed. world health organization, geneva, 1997. 5. jamel h, plasschaert a, sheihan a. dental experience and availability of 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in comparison with digital impression (an in vitro study) elaf a. hadi, b.d.s. (1) adel f. ibraheem, b.d.s., m.sc. (2) abstract background: the success and maintenance of indirect dental restorations is closely related to the marginal accuracy, which is affected by many factors like preparation design, using of different fabrication techniques, and the time of taking final impression and pouring it. the purpose of this in vitro study was to evaluate the effect of different pouring time of conventional impression on the vertical marginal gap of full contour zirconia crowns in comparison with digital impression technique. materials and methods: forty sound recently extracted human permanent maxillary first premolar teeth of comparable size and shape were collected. standardized preparation of all teeth samples were carried out to receive full contour zirconia crown restoration with deep chamfer finishing line all around the tooth with (1mm) depth, axial length (4mm) and convergence angle (6 degree). the specimens separated into two groups; group a; eight specimens were scanned digitally by using omnicam scanner; group b; conventional impressions were taken for the remaining thirty two specimens and further subdivided to four groups according to the time of impression pouring; group b1: pvs were poured after 30 minutes; group b2: pvs were poured after 24 hours; group b3: pvs were poured after 7 days; group b4:pvs were poured after 14 days. marginal discrepancy was measured at four points at each tooth surface. sixteen points per tooth were measured using digital microscope at (180x) magnification. one-way anova test and lsd test were carried out to see if there was any significant difference among the means of the conventional impression groups. independent samples t-test was carried out to examine if there is any significant difference between digital and conventional impression technique. results: group b2 had the least mean of marginal gap with statistically significant difference when compared to group b1 and statistically highly significant difference when compared to group b3 and b4. there was a statistically highly significant difference in the vertical marginal gap between digital impression technique and conventional impression. conclusions: the pouring of conventional impression after 24 hours provides better marginal fit than other pouring time. the digital impression provides better marginal fit than conventional impression. key words: marginal accuracy, pouring time, conventional impression, (j bagh coll dentistry 2017; 29(4):1-6) introduction the first step required to fabricate well-fitting indirect restorations is precise dental impressions with high degree of dimensional stability and fine details reproducibility. the accuracy of the impression material reflects its ability to be dimensionally stable over time, therefore the amount of time elapses between securing the impression and casting in gypsum greatly affect the quality of restoration (1). although the delay of pouring period allows both the release of volatile substances and elastic recovery of the material, it should be limited; otherwise distortions of the impression will occur. pvs impression materials are the most dimensionally stable and can be poured hours, days or even weeks after impression taking. however, their dimensional stability also depends on the exact time of pouring stone dies (2). (1) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. the most important factor that determines the survival and success of fixed prosthesis is the marginal fitness. marginal misfit or large gap negatively affects the prosthesis, which may lead to microleakage with plaque accumulation thus increasing the risk of recurrent caries and periodontal inflammation (3, 4). marginal gap does not only depend on the design of the tooth preparation, finishing line type, type of cementation medium only but also on the proper impression (5). the dimensional accuracy of the elastomeric impression materials based on various factors such as the delay or second pour, humidity, temperature, and impression techniques (6). the introduction of cad/cam systems in 1980s to the dental field resolved a wide range of these limitations found in the conventional impression techniques since they provide speed, property of storing and transferring captured images indefinitely with no distortion (7). studies have been reported the average marginal discrepancies for cad/cam restoration range from 24-110 μm(8). j bagh college dentistry vol. 29(4), december 2017 the effect of different among restorative dentistry 2 materials and methods samples preparation each tooth samples was prepared to receive full contour zirconia crown with the following preparation features; a flat occlusal surface with (4mm) axial length, deep chamfer finishing line 2 mm coronal to the cemento-enamel junction all around the tooth with (1mm) depth, and convergence angle of 6◦ (9,10)as shown in (fig.1). figure 1: tooth preparation using a modified dental surveyor. conventional impression procedure eight impression trays especially designed for this study were made with three pins in the base of the special tray to engage the three holes on the acrylic base of each specimen, these holes serve as a guide and stopper for the special tray during impression procedure. the top surface of the special tray has a metal rod attached to the suspending arm of the dental surveyor during impression taking procedure to ensure a standardized path of insertion and removal of the special tray during impression taking. one step impression technique was done for four subgroups (b1, b2, b3, and b4) by using heavy and light viscosity polyvinyl siloxane impression materials. the heavy viscosity impression material (express™ xt penta™ heavy) was loaded in the special tray, while light viscosity vinyl polysiloxane impression material (express ™ xt) was injected all around the prepared tooth. the tray was then seated over the specimen until the three guided pins completely engaged the holes in the acrylic base of the specimen and the tray kept under a defined load of 500g until the complete set of impression material (11) as shown in (fig.2). after about 3.5 minutes, the two impression materials were set (according to the manufacturer’s instructions) and removed from the specimen. figure2: impression taking with the dental surveyor. pouring procedure the impression was poured with type iv gypsum (die stone) which was mixed with distilled water with a powder/water ratio of (100g/25ml). the amount of powder was measured using a digital scale, while the amount of water was measured using a graduated glass tube, and mixed for 60 seconds. the impression was poured using a vibrator. the stone die was separated from the impression after 45 minutes according to the manufacturer’s instructions. the same pouring procedure was repeated (for subgroups b1, b2, b3, and b4) after the storage of impressions at different times (30 minutes, 24 hours, 7 days, and 14 days) respectively in an incubator at room temperature (25°c) according to the manufacturer’s instructions. fabrication of crowns scanning the teeth (for group a) was taken using omnicam scanner (sirona dental systems, bensheim, germany). the scanning was carried out by moving the camera head over the teeth in a single flowing motion from buccal, occlusal and palatal surfaces in continuous motion, and then the data was generated successively into a 3d model on the monitor with natural color as shown in (fig 3).the scanning of the dies (for subgroups b1, b2, b3, and b4) was carried out using ineosx5 blue scanner (sirona dental systems, bensheim, germany) as shown in fig.3 j bagh college dentistry vol. 29(4), december 2017 the effect of different among restorative dentistry 3 figure 3: scanning of teeth using omnicam scanner figure 4: scanning of die stone using ineos x5 blue scanner the designing of the crown in “model” phase was the next step. the margin of the preparation was automatically detected by the software system. the undercut was checked and the path of insertion was determined. crown milling parameters were determined according to sirona instructions as follows: die and tooth spacer (80μm), marginal thickness (150μm), minimum radial wall thickness (500μm), minimum occlusal thickness (700μm), and margin thickness (150μm). milling of incoris tzi c disk using sirona cerec inlab mcx5. after the milling was completed, zirconia crowns were chalky in color and milled approximately 20-25% greater in size; therefore they needed dense sintering process in infire htc speed oven (sirona, germany) at 1540º c for two hours. measurement of marginal gap the vertical marginal gap was measured at four indentations on the margin area at the midpoint of buccal, mesial, palatal and distal surfaces of the tooth by using a digital microscope (12, 13). in order to maintain a constant seating pressure between the crown and the tooth during measurement of mg, the specimen attached to specimen holding device which specially designed to maintain constant pressure of (50n) nearly equal to (5kg) and placed under the digital microscope (14). the digital microscope was used at a magnification of 180x that was fixed in a manner that maintains its lens perpendicular to the crown/tooth margin during measurement procedure and connected via the computer. the digital images were captured and the measurements were done using image j software which calculated the values in pixels (15) (fig 5). for the calibration of the software, a photograph of a(1mm) increment taken at the same focal length and input into(image j) by the option of set scale, which converted all the calculated reading from pixels to (μm)(16). figure 5: digital image captured by digital microscope. statistical analyses data were collected and analyzed using spss (statistical package of social science) software version 15 for windows 8.1 chicago, usa. the following statistics were used: adescriptive statistic: including mean, standard deviation, statistical tables and graphical presentation by bar charts. binferential statistics 1-one-way anova (analysis of variance) test was carried out to see if there was any significant difference among the means of the conventional impression groups. 2-lsd (least significant difference) test was carried out to examine the source of difference. 3independent samples t-test was carried out to examine if there is any significant difference between digital and conventional impression technique. j bagh college dentistry vol. 29(4), december 2017 the effect of different among restorative dentistry 4 results total of (640) measurements of vertical marginal gap from five groups were recorded, with 16 measurements for each crown. table 1: descriptive statistics of vertical marginal gap for the five groups in (μm) max. min. s.d. mean no. of sample group 44.673 37.961 ±2.447 40.635 8 a-omnicam scanner 55.579 48.036 ±2.760 52.775 8 b1pouring conventional impression after 30 minutes 52.059 41.736 ±3.306 48.867 8 b2pouring conventional impression after 24 hours 76.769 65.436 ±4.620 71.676 8 b3pouring conventional impression after 7 days 97.525 83.893 ±5.470 90.971 8 b4pouring conventional impression after 14 days table (1) showed that the highest mean of vertical marginal gap was recorded in group b4 (90.971±5.470) (pouring polyvinyl siloxane impression after 14 days) while the lowest mean marginal gap was recorded in group a (40.635 ±2.447) (digital impression using omnicam scanner) and this clearly explained in (fig.6). figure 6: the mean values of the vertical marginal gap of all groups table 2: oneway anova test among the four conventional impression subgroups. anova sum of squares df mean square f-test pvalue between groups 8,993.429 3 2,997.810 171.717 0.000 (hs) within groups 488.821 28 17.458 total 9,482.250 31 significant at p≤ 0.05 table 2 showed that there was a statistically highly significant difference in the vertical marginal gap among the four subgroups(b1, b2, b3, and b4) table 3: lsd test for comparison of significance between subgroups b1, b2, b3, and b4. mean difference p-value b1 b2 3.90825 0.042 (s) b3 -18.90113 0.000 (hs) b4 -38.19563 0.000(hs) b2 b3 -22.80938 0.000 (hs) b4 -42.10388 0.000 (hs) b3 b4 -19.29450 0.000 (hs) table (3) showed that there was a statistically significant differences in the marginal gap mean values between (subgroup b1 and subgroup b2), and a highly statistically significant differences in the marginal gap mean values between (subgroup b1 and subgroup b3), (subgroup b1 and subgroup b4), (subgroup b2 and subgroup b3), (subgroup b2 and subgroup b4), (subgroup b3 and subgroup b4). table 4: independent samples t-test between group a and b2 t-test for equality of means df sig. (2tailed) value equal variance assumed -5.660 14 0.000 equal variance not assumed -5.660 12.901 0.000 table (4) showed that there was a statistically highly significant difference in the vertical marginal gap between digital and conventional impression. discussion the results of this study revealed that the pouring of the conventional impression after 24 hours provided less marginal gap than other times of pouring of conventional impression. this may be due to shrinkage of the addition silicone towards the tray which produced larger die, therefore provided better seating of the crown with less marginal gap than the marginal gap of crowns fabricated from pouring the impression after 30 min. this explanation comes in agreement with kumar et al (17) who concluded that addition silicones after 24 hours contracted towards the tray and gave a die slightly bigger in diameter than the standard master die. the gap of the zirconia crowns that fabricated after 7 and 14 days of impression pouring were 0 20 40 60 80 100 40.635 52.775 48.867 71.676 90.971 groups a b1 b2 b3 b4 j bagh college dentistry vol. 29(4), december 2017 the effect of different among restorative dentistry 5 increased, this might be due to delay shrinkage of impression away from the tray which was lead to smaller die and result in an increase in the gap between the crown and the tooth. this delay in dimensional changed of addition silicone is explained by fano et al.(18)who concluded that the instability of pvs due to the polymerization reaction is complete after hours, but the contribution of the constituent evaporation can have a significant long-term role. this dimensional change of the impression over time is in agree with garrofé et al. (19) who study the accuracy of three types of addition silicone over time up to 14 days and found significant differences for time-material interaction. the dimensional changes with delay in pouring occurred in addition silicone may result, among other reasons, from incomplete elastic recovery due to viscoelastic behavior of the material, relaxation of stresses, or from residual polymerization in which new covalent bonds are formed within the material molecules reducing the volume occupied by them. thus loss of accuracy will occur over time (18, 19, 20). the results of this study revealed that the digital impression technique provided less marginal gap than the conventional impression. the difference in the marginal gap between two groups might be due to the steps that required with conventional impression procedure like tray selection, disinfection, casting stone model, manual die trimming, and other steps needed for articulation are eliminated (21).furthermore, an enhanced intraoral optical camera might have the ability to recording fine details which in turn lead to a better adaptation of crown (22). this result comes in agree with bindl and mormann; khdeir and ibraheem (9,23) who concluded that crown restorations fabricated using chairside intraoral scanner showed better marginal adaptation than those made from dental casts scanning. however, this finding is not in agreement with (23) who concluded that accuracy of the digital impression is similar to that of the conventional impression. such disagreement could be due to the difference in the methodology used. references 1. neethu, l. &gilsa, k. v. comparative evaluation of dimensional stability of three different elastomeric impression materials – an in vitro study. jdms, 14(9), 89-93, 2015. 2. eduardo, b. f., leonardo, f.c. &ana, r.b. effect of storage period on the accuracy of elastomeric impressions. j appl. oral sci, 15(3), 195-8, 2007. 3. contrepois, m., soenen, a., bartala, m. &laviole, o. marginal adaptation of ceramic crowns: a systematic review. j prosthet dent, 110, 447-54, 2013. 4. hamza, t.a., ezzat, h.a, el-hossary, m.m., katamish, h.a., shokry, t.e. &rosenstiel, s.f. accuracy of ceramic restorations made with two cad/cam systems. j prosthet,109, 83-7, 2013. 5. anadioti, e. internal and marginal fit of pressed and cad lithium disilicate crowns made from digital and conventional impressions. master thesis, department of oral science, university of iowa. 2013. 6. pant, r., juszczyk, a. s., clark, r. k. f. & radford, d. r. long-term dimensional stability and reproduction of surface detail of four polyvinyl siloxane duplicating materials. j dent,36(6), 456-61, 2008. 7. kim, s.y., kim, m.j, han, j.s, yeo, i.s, lim, y.j. &kwon, h.b. accuracy of dies captured by an intraoral digital impression system using parallel confocal imaging. int j prosthodont, 26(2), 161-3, 2013. 8. karatasli, o., kursoglu, p., capa, n.&kazazaoglu, e. comparison of the marginal fit of different coping materials and designs produced by computer aided manufacturing systems. dent mater j, 30(1), 97-102, 2011. 9. bindl, a.&mormann, w.h. marginal and internal fit of all-ceramic cad/cam crown-copings on chamfer preparations. j oral rehabil, 32, 441-7, 2005. 10. al-joboury, a.i. an evaluation of the influence of different finishing lines on the fracture strength of full contour zirconia cad/cam and heat press allceramic crowns. a master thesis, college of dentistry, university of baghdad. 2013. 11. duseja, s., shah, r.j., shah, d.s. & duseja, sh. dimensional measurement accuracy of recent polyether and addition silicone monophase impression materials after immersion in various disinfectants: an in vitro study. international j. of healthcare and biomedical research,2(4), 87-97, 2014. 12. holmes, j.r., bayne, s.c., holland, g.a. &sulik, w.d. considerations in measurement of marginal fit. j prosthet dent, 62(2), 405-8, 1989. 13. holden, j., goldstein, g., hittelman, e. & clark, e. comparison of the marginal fit of pressable ceramic to metal ceramic restorations. j prosthodont, 18, 645-8, 2009. 14. dittmer, m.p., borchers, l., stiesch, m.& kohorst, p. stresses and distortions within zirconia-fixed dental prostheses due to the veneering process. acta biomater, 5, 3231-9, 2009. 15. tan, p.l., gratton, d.g., diaz-arnold, a.m. &homles, d.c. an in vitro comparison of vertical marginal gaps of cad/cam titanium and conventional cast restorations. j prosthodont, 17(5), 378-83, 2008. 16. romoe, e., iorio, m., syorelli, s., camandona, m. &abati, s. marginal adaptation of full coverage cad/cam restorations: in vitro study using a nondestructive method. minerva stomatol, 58(3), 61-72, 2009. 17. kumar, d., madihalli, a.u., reddy, k.k., rastogi, n. & pradeep, n.t. elastomeric impression materials: a comparison of accuracy of multiple pours. j of contemporary dental practice, 12(4), 272-8, 2011. 18. fano, v., gennari, p.u. &ortalli, i. dimensional stability of silicone-based impression materials.dent mater j,8,105-9, 1992. 19. garrofέ, a.b., ferrari, b.a., picca, m. & kaplan, a.e. linear dimensional stability of j bagh college dentistry vol. 29(4), december 2017 the effect of different among restorative dentistry 6 elastomeric impression materials over time. acta odontol latinoam, 24(3), 289-94, 2011. 20. mehta, r., dahiya, a., mahesh, g., kumar, a., wadhwa, s., duggal, n. &pande, s. influence of delayed pours of addition silicone impressions on the dimensional accuracy of casts. johcd, 8(3), 148-53, 2014. 21. burgess, j.o., lawson, n.c.&robles, a. digital impression system considerations. j inside dent, 11(9), 2015. 22. beuer, f., schweiger, j. & edelhoff, d. digital dentistry: an overview of recent developments for cad/cam generated restorations. br dent j, 204 (9), 505-11, 2008. 23. khdeir, r.m.&ibraheem, a.f. the marginal fitness of cad/cam all ceramic crowns constructed by two types of direct digitization techniques (an in vitro study). jbcd, 28(2), 30-3, 2016. 24. ender, a. &mehl, a. full arch scans: conventional versus digital impressions—an in-vitro study. int j comput dent, 14(1), 11-21, 2011. الخالصة عا سرررلمش راورررط ا النمشرررطرا ا نمورررماةايدرررماهماشيررراا ايمرترررياعاة ارررل ايلرررماطاهلرررشرا ت رررر ار ررر ا رررلي ا ال ررريطايرررط نجاح رررمواة يلترررراا الطنينرررم ا ا ررر ياا يرررط الدةيشيررايررااةهررنيملااررلاااهررمما ايررشلارررةااررلتا اشا سرراا الملنطيرراااررتا ديرري ا ررمايطا بررل لا ةيررم اهرر ا اهنلررم ا ائ رر يمارملة,رراعاةةيرراا بررلا اهنلرراا ا يم ا ةىا الهمهقا ايمرتيا اللت ااةلي مما ازانتحياانمرةاا اتك اهمالدماحاارما د ياا اهنلاا اطيليال (حلرررتمناررررةا اسررر مما ا رررت لاا اةارررىا الةيرررما الدةت ررراااترررط ا الررر نا الدرررتيليام ال ررر اةشرررك ارلدرررما ل ا ,يرررلا يطييمسررريااكررر ا04 ررر ا ليرررما ا6رةررر (عاةي ةيررراارررري ما ا0رة (عةورررتحار رررتا ا 1 ي رررم ا اسررر مماالةدررريا الي رررمما ازانتحيررراانمرةررراا اترررك اررررمالمهرررااا تيرررااحرررت ا اترررللا الليرررقاهللرررقا ي ررررم ا رررر ا ررررتيطاماهت 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(1) ban sahib diab b.d.s, m.sc., ph.d. (2) abstract background: chronic periodontitis is a bacterial infection that result in bone destruction associated with the increasing level of salivary tumor necrosis alpha and interleukin6 that affect mother-infant bonding status. the aim of the present study was to assess the relationship between the mother-infant bonding status in mothers with chronic periodontitis in relation to salivary tumor necrosis factor alpha and salivary interleukin6. materials and methods: the selected sample consisted of mothers with chronic periodontitis compared with mothers with healthy periodontium in postpartum period, their age ranged between 30-40 years. both groups were subjected to postpartum bonding questionnaire (pbq). periodontal health status was assessed for control group like plaque index and gingival index in order to obtain control group with healthy periodontium, while measuring probing pocket depth and clinical attachment level in addition to plaque and gingival index for study group. salivary tumor necrosis factor alpha and interleukin6 measure in saliva by enzyme-linked immune sorbent assay (elisa). results: the mean values of salivary tumor necrosis factor alpha and interleukin 6 were found to be higher among mothers with chronic periodontitis than mothers with normal bonding relationship, and the percentage of disorder mother-infant bonding relation was higher in study group than in control group. conclusion: mother-infant bondings affected by chronic periodontitis as the patient have higher salivary tumor necrosis factor alpha and salivary interleukin6 than mothers with healthy periodontal condition. key words: chronic periodontitis, mother-infant bonding, salivary tumor necrosis factor alpha, salivary interleukin6. (received 1/4/2019; accepted 5/5/2019) introduction periodontitis is a bacterial infection produced by various oral microorganisms (1). which results in the formation of soft tissue pockets and its severe forms can lead to bone loss or tooth mobility. although bacteria are essential for periodontal disease to take place, susceptible host is also just as important. host inflammatory response is a defensive reaction but both hypo-responsiveness and hyper-responsiveness can result in advanced tissue destruction (2). periodontitis was resulted mainly to untreated gingivitis, chronic periodontitis may occur as a localized disease in which less than 30% of examined periodontal sites demonstrate clinical attachment and bone loss. moreover, it may occur as a more generalized disease with more than 30% of sites was affected (3). maternal-newborn bonding is a concept used throughout the obstetrical and pediatric fields, but not widely known amongst all clinicians. the connection made after birth directly affects both the mother and newborn physiologically, psychologically and emotionally. a strong bond formed between a mother and infant leads to positive outcomes and impacts the maternal child relationship through the lifespan. “the parentinfant bond provides a foundation for future adaptation, relationships, and mental health for children and adults” (4). (1) ph.d. student, department of periodontology, college of dentistry, university of baghdad. (2) professor, department of pedodontic and preventive dentistry, college of dentistry, university of baghdad. in the postpartum period, the initiation and progression of the connection between the mother and her infant is an important psychological step that presented as a challenge to the mother. bonding is the term usually used to describe this relationship (5). the negative response of the mother toward the infant’s stimuli is called ‘maternal bonding disorder’ (6). there are many manifestations of bonding disorder: delay, ambivalence or loss in maternal response, threatened or established rejection, pathological anger, and infant abuse (7). the attachment theory that was constructed by bowlby, 2008 (8). proposed that the person requires or needs to form an affectionate connection with a caregiver (mainly the mother) from the unborn phase and as getting older this emotional requisite is beyond the feeding needs. as a child, these psychological actions are wanted to create comforting, protecting, warm, and loving feelings. some factors have the potential to create barrier that affect the bonding process which include a lack of support, the riskiness of the pregnancy, maternal fatigue, and lack of confidence in parenting abilities, other factors that influence negatively or positively the bonding relationship include: pattern of infant feeding (9, 10), depression (11), separation of the premature infant from the mother after birth (12, 13), and others. the quality of the maternal-newborn relationship can have a significant impact on the 30 j bagh college dentistry vol. 31(3), september 2019 mother-infant bonding mother’s mental health and newborn’s wellbeing, development, and adaptation throughout life (14). several questionnaires have been produced to evaluate the bonding status, even though the postpartum bonding questionnaire (pbq) which was introduced by brockington et al., 2006 had been largely studied regarding the validity and reliability which was easy to be applied (15,16). tumor necrosis factor alpha (tnf-α) is one of the important periodontal pathogens-induced by early inflammatory cytokines in the destructive periodontal disease (17). elevated levels of tnf-α are well-known risk factor for the destructive periodontal disease (18). it is contributing to the beginning of the destructive periodontal disease via several mechanisms. examples of these mechanisms are: (i) tnf-α prompts the destruction of the alveolar bone by stimulating the formation of bone-resorbing cells (osteoclasts) (19); (ii) tnf-α, is considered as a one of the early promoters of the host response to the periodontal bacterial pathogens, regulates the matrix metalloproteinase (mmps), which are capable of degrading the connective tissues. interestingly, studies on the immune response to periodontal pathogens exhibited that tnf-α enhanced the immune response to these pathogens (20). interleukin-6 (il-6) is a cytokine with an extensive range of biological activities. it is a mediator for the immunoglobulin substituting and it has a role in controlling the acute phase response. it is also an inflammatory indicator within body (21). for the occurrence of bacteremia, il-6 can also use as an investigative marker. interleukin-6 is produced by innate immune cells such as macrophages and dendritic cells but also by some cd4+, t-cells in addition to nonimmune cells such as fibroblasts and endothelial cells (22). interleukin-6 is elevated in many inflammatory diseases and mainly functions to activate b-lymphocytes furthermore it has a role in influencing the balance of cd4+ effector on tcell populations and potentially influencing myeloid cell differentiation (23). as far there is no previous iraqi study concerning the effect of chronic periodontitis through the inflammatory mediators on the bonding between lactating mothers and their infants, this study was conducting in order to find the relation between salivary tnf-α and il-6 on the bonding status. materials and methods the selected sample composed of 90 lactating mothers aged 30-40 years where 45 lactating mothers were with chronic periodontitis and they represent the study group. they were selected according to the criteria of chronic periodontitis which involved gingival recession resulting from loss of attachment and alveolar bone loss, pocket formation, loss of periodontal attachment, loss of alveolar bone, root furcation exposure and tooth mobility in advanced cases of bone destruction) (24). forty-five lactating mothers with healthy periodontium were selected to represent the control group. the participants were informed about the aim of the study and they were freely allowed to accept the examination. informed consent and ethical approval had been obtained. the participants were selected and examined in the health centers of diyala governorate and ruler area during the attendance to the primary health care for the purpose of vaccination. exclusion criteria involved mothers who were unwilling to participate in the study, those who were on contraceptive pills or other medications, pregnancy, smoking, and systemic diseases. unstimulated salivary samples were collected from the mothers. the mothers were advised refrain from intake of any food or beverage (water exempted) one hour before the test session. the mothers were advised to rinse their mouth several times with distilled water and then to relax for five minutes. the mothers should minimize movements, particularly mouth movements during collection and lean the head forward keeping the mouth slightly opened to allow saliva to drain into the tube. for the salivary pro-inflammatory cytokines, tnf alpha and il6were measured in both groups of the lactating mothers using elisa kit and the enzyme-linked immune sorbent assay (elisa).the postpartum bonding questionnaire (pbq) was used to estimate the mother-infant bonding relationship status (25). the pbq has twenty-five statements, each followed by 6 alternative replies. a high score signals pathological condition. the questionnaire has four factors: general factor, rejection and pathological anger, anxiety about the infant and incipient abuse. in this study, a total score of 19 attained the maximum split between mothers with normal mother-infant relationship and those with some type of disorder, the total scores of all items of the questionnaire has a maximum of 125. the mothers who attended the health centers were asked to complete all the components of the postpartum bonding questionnaire by themselves without assistance or discussing the answers with others. oral examinations were done under standardized conditions according to the basic methods of oral health surveys of world health organization (26). the pocket depth was measured using calibrated periodontal probes (william’s 31 j bagh college dentistry vol. 31(3), september 2019 mother-infant bonding probes) at four surfaces of all the examined teeth except the third molars. the sites for the measurements were mid-buccal, mid-palatal, mesiobuccal and distobuccal lines a scale was used for the ease of estimation (27): score 0: 1-3mm score 1: > 3-5mm score 2: > 5-7mm score 3: > 7mm the attachment loss was measured by using the periodontal probe at four sites for all examined teeth except third molar by: 1. measuring the distance from the free gingival margin to the cemento-enamel junction. 2. measuring the distance from free gingival margin to the bottom of the sulcus or pocket at each site. the interproximal recording should be secured at the buccal aspect of the interproximal contact. 3. the attachment loss was obtained from subtracting the first measurement from the second one. 4. recession was recorded as a negative value that means the attachment loss was obtained from adding the first measurement to the second one. clinical attachment loss readings were divided into 4 scores (28): score 1: 1-3 mm score 2: > 3-5mm score 3: > 5-7mm score 4: > 7mm results distribution of the mothers according to infant bonding status is illustrated in table 1 that shows the percentage of the disordered mother which was 95.56%for the study group while for the control group the opposite figure was found as the percentage of the disordered mothers was only 4.44%. table 1: mother-infant bonding status distribution mother-infant bonding status mother-infant bonding status normal disorder groups study number 2 43 % within groups 4.44 95.56 % of total 2.22 47.78 control number 43 2 % within groups 95.56 4.44 % of total 47.78 2.22 the results revealed a positive correlation between mother-infant bonding status and the mean of the probing pocket depth and the mean of the clinical attachment level, although the results were not significant statistically as shown in table 2. table 2: correlation coefficient between mother-infant bonding status and periodontal parameters (probing pocket depth and clinical attachment level). periodontal parameters r p value probing pocket depth score 1 0.007 0.962 probing pocket depth score 2 -0.111 0.467 probing pocket depth score 3 0.181 0.235 probing pocket depth mean 0.124 0.418 clinical attachment level score 1 -0.146 0.339 clinical attachment level score 2 0.036 0.812 clinical attachment level score 3 0.250 0.097 clinical attachment level mean 0.215 0.156 the results report that mother-infant bonding relation among the study and the control group had positive correlations with salivary tnf alpha and salivary il6. however, the results were not statistically significant among the study group in relation to il6 and in relation to tnf alpha, while it was significant among the control group in relation to il6 and in relation to tnf alpha as illustrated in table 3. table 3: relation between mother-infant bonding status and salivary il6 , salivary tnf group il6 tnf α r p r p study 0.257 0.088 0.050 0.746 control 0.290 0.053 0.309 0.039 discussion since there are no available previous iraqi studies concerning the relationship between motherinfant bonding and periodontal health status, this study was conducted to investigate the impact of the periodontal health on the maternal bonding. the result of the present study showed that the percentage of the disordered mothers was higher among the study group than that found among the control group, this could demonstrate the association between the chronic periodontitis and 32 j bagh college dentistry vol. 31(3), september 2019 mother-infant bonding the mother-infant bonding status and can be explained as bidirectional. this finding also confirmed by the results of the present study that demonstrated a positive relation with probing pocket depth score 1 and 3, and clinical attachment level score 2 and 3. one mechanism that had been proposed for the chronic periodontitis as a hazard factor for other systemic diseases comprises systemic dissemination of oral bacteria and inflammatory mediators (29) and that belong to the proinflammatory common systemic mediators such as tnf-α and il-6. remarkably, it had been shown that these cytokines were increased in the gingival crevicular fluid in patients with chronic periodontitis who did not have chronic systemic diseases (30). it had been detected that immunological activation induces stress-like behavioral and neurochemical changes in organs of humans (31).as the current study showed a positive relation between mother-infant bonding status and salivary tnf, il6 and these proinflammatory cytokines along with other compounds such as corticotropin releasing hormone (crh) are obviously involved in the pathogenesis of stress (32). activation of cytokine receptors and changes in cytokine are thought to play important roles in neuronal dysfunction and pathogenesis of stress (33). trigger factors may induce depressive symptoms. in addition activated protein kinase (ampk) which is tightly controlled by the cellular amp/atp ratio, plays a central role in the regulation of energy; homeostasis and metabolic stress (34). cytokines are also involved in stress response and participate in neurochemical, behavioral and endocrine changes due to illness, il6 increases following a neurogenic inflammatory stimulus (35). in conclusion, the periodontal health status of the mother influences the maternal bonding status, so recognition and identification of the periodontal health status would allow psychological intervention to improve the motherinfant bonding relation. however, further studies are needed to determine the effect of biomarkers in relation to oral health status to investigate the exact impact of chronic periodontitis on the bonding status of the mothers. refrences 1. zhang l, henson bs, camargo pm, wong dt. the clinical value of salivary biomarkers for periodontal disease. periodontology 2000. 2009;51(1):25–37. 2. pihlstrom bl, michalowicz bs, and johnson nw. periodontal diseases. lancet 2005: 366: 1809-1820 3. petersen, p.e., bourgeois, d., ogawa, h., et al. 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for the experimental (s) group, the defect was treated with hemostatic absorbable gelatin sponge; and for experimental (rs) group, the bony defect was treated with 0.2 ml red clover oil and covered by haemostatic absorbable gelatin sponge. six rats from each group were sacrificed at 2 and 4 weeks intervals. histomorphometric analysis was performed on h&e bone section of all the studied groups which includes counting of bone cells (osteoblasts, osteocytes and osteoclasts), trabecular number, trabecular area and bone marrow space area. results: histomorphometric results of bone cells revealed that the combination group stimulated larger numbers of osteoblasts and osteocytes than in sponge and control group. number of new bone trabeculae, trabecular area and bone marrow space area showed higher mean values in combination groups than others. highly significant differences between groups were observed in all histomorphometric parameters throughout all durations. conclusion: red clover oil stimulated larger numbers of osteoblasts and osteoclasts, indicating increased bone remodeling especially at 2 weeks interval as compared with sponge and control groups. key words: bone defect, red clover, rats. (received:15/8/2019; accepted:24/9/2019) introduction bone mending is a profoundly effective procedure that takes into account the scar less recovery and redesigning of imperfections identified with the treatment of injury, pathology, or inborn variations from the norm. bone fix was a multistep procedure including relocation, expansion, separation, and initiation of a few cell types.(1) bone redesigning requires the relations between numerous bone cells to revamp, protect, or direct bone quality or potentially mineral homeostasis in the light of adjusting natural impacts. there were four discrete stages to this procedure: initiation, retention, inversion, and development with ingestion; that occurs through osteoclasts and osteoblasts, correspondingly.(2) bone imperfections attempt accommodating recuperating strategy through synchronized accompanying advancement of skeletal and vascular segments in a delicate cartilage callus setting. among this setting, (1) professor, department of oral diagnosis, college of dentistry, university of baghdad. (2) master student, department of oral diagnosis, college of dentistry, university of baghdad. corresponding email, nada_gaban@yahoo.com bone restoration restates a few of the equivalent cell and sub-atomic systems that delivers the embryonic bone.(3) red clover (trifolium falsification) is a perpetual herb developing in all mild and subtropical zones in the world over. in a few societies, it is utilized as customary prescription, other than its daidzein and genistein content, red clover shows a high substance of methylized forerunners: biochanin a and formononetin.(4,5) isoflavonoids mixes present in red clover oil are the primary dynamic substances of "phytoestrogens". epidemiological and clinical research revealed constructive outcomes of isoflavone utilization over bone with the danger of building up a few osteoporosis.(6) this study aims to examine the impact of red clover oil on bone healing in rats histomorphometrically. material and methods: thirty six males healthy albino rats, aged between (4-5) months with weight ranged between (250-300 mg), were used in this experimental study. all rats were kept under supervision and nursing from the staff of the animal house of biotechnology research https://doi.org/10.26477/jbcd.v32i2.2891 j bagh college dentistry vol. 32(2), june 2020 histomorphometric 27 center/university of al-nahrain, baghdad, iraq. all experimental procedures were conducted in accordance with the ethical approval of animal experiments of college of dentistry, university of baghdad. intra bony defect of about 2 mm in width and 3 mm in depth was performed in right femur of each rat.(7) then rats were randomly divided into three groups (12 rats each): 1) control group (c): the bonydefect was left for spontaneous normal healing. 2) experimental group(s): the bony defect was treated with hemostatic absorbable gelatin sponge. 3) experimental group (rs): the bony defect was treated with 0.2 ml(8) red clover oil (trifolium pratense) and covered by haemostatic absorbable gelatin sponge. then six rats from each group were sacrificed at the end of recommended periods (2 and 4 weeks). the right femur was dissected and the soft tissue was removed to expose the entire bone to be cut at 5 mm away of the defect sides. the bone specimens immediately were stored in 10% freshly prepared formalin and left for 2 days for fixation. bone decalcification was performed by using formic acid sodium citrate solution, which was prepared freshly from 2 solutions (125 cc formic acid 90%, 125 cc distilled water and 50 mg sodium citrate, 250 cc distilled water).(9,10) then, bone tissue was dehydrated with alcohol and embedded in paraffin. sections of 5 μm were prepared in the usual fashion, and stained with hematoxylin and eosin. histological examination was performed using light microscope. histomorphometric assessment of bone cells (osteoblast, osteocyte and osteoclast), trabecular area, trabecular numbers and bone marrow space area was performed by software program (image j. exe), which is an image processing program developed at the national institutes of health.(11) results histological results acontrol group: histological view of bone defect revealed sparse of bone trabecular coalesce with cutting bone in control group of 2 weeks duration. osteocytes in newly formed trabecular enclosing areas of marrow tissue and large number of osteocytes are embedded in bone (fig.1). at 4 weeks duration, the osteoblasts were noticed at peripheries of the thick bone trabecular and osteocytes inside these bone (fig.2). bsponge group (s): the histological examination of this group after 2 weeks duration illustrated the deposition of bone trabeculae that replaces areas of bone defect (fig.3). at 4 weeks, the osteoblasts are seen at peripheries of the bone, osteocytes seen arranged in circular around haversian canal (fig.4). ccombined red clover oil and sponge group (rs): histological examination of this group after 2 weeks revealed thick well developed bone trabeculae filled defect area with numerous blood vessels and inflammatory cells inside bone marrow (fig.5). at 4 weeks mature bone filled defect area by presence of osteon (fig.6). statistical analysis of histomorphometric findings tables (1 and 2) show comparison differences using anova and lsd test among all studied groups at different healing periods for bone parameters trabecular area (bta), trabecular number (tn) and bone marrow area (bma) in control(c), sponge (s) and combination (rs) groups in both healing periods (2 and 4 weeks). the result showed a highly significant difference between all groups in both durations (two and four weeks) for these three bone parameters. j bagh college dentistry vol. 32(2), june 2020 histomorphometric 28 figure (1): control group at 2-weeks showing basal bone (bb), blood vessels (bv), inflammatory cells (ic) and osteocytes (oc). h&ex40 figure (3): sponge group at 2-weeks showing new bone trabeculae (bt), osteoclasts (ocl) and inflammatory cells (ic). h&e x40. figure (5): rs group at 2-weeks showing new bone filled by osteocytes (oc) lined by osteoblasts (ob), blood vessels (bv), inflammatory cells (ic), osteoclasts (ocl) and reversal line (rl). h&ex40 figure (2): control group at 4-weeks showing osteoblasts (ob) lined haversian canal and osteocytes (oc) filled bone. h&e x40 figure (4): sponge group at 4-weeks showing regular arrangement of osteocytes (oc) around haveresian canal (hc) and osteoblasts (ob). h&ex40 figure (6 ): rs group at 4-weeks showing mature bone (osteon formation) by regularly arranged osteocytes (oc) around haversian canal (hc) and osteoblasts (ob) seen riming haversian canal (hc). h&ex40 j bagh college dentistry vol. 32(2), june 2020 histomorphometric 29 table 1: anova group comparisons for bone parameters. according to the anova test, there was a highly significant difference among all studied groups in both 2 and 4 weeks intervals in bone cells except for osteoclasts at 4 weeks duration which was significant as shown in table (3). disscusion within the last decade the use of natural supplements has become more widespread in the search for viable alternatives to existing treatments. red clover (trifolium pratense) is a medicinal herb containing flavonoids and isoflavones. red clover contains at least 9 isoflavones including formononetin, biochanin a (glycosides), daidzein and genistein (aglycones) which promote the formation of variable duration group comparisons f -test pvalue bta 2 weeks 33.5 0.0003 4 weeks 42.9 0.0005 ta 2 weeks 29.4 0.0002 4 weeks 19.7 0.0001 bma 2 weeks 52.3 0.0006 4 weeks 112.7 0.00008 variable s dura -tion gro ups comparisons m.d pvalue sig. osteobla st 2 week c/ s -10.4 0.003 hs c/ rs -11.8 0.0091 hs s / rs 11.03 0.0075 hs 4 week c/ s -6.8 0.0013 hs c / rs -7.0 0.0011 hs s / rs -6.92 0.004 hs osteocla sts 2 week c/ s -0.10 0.006 hs c / rs 0.12 0.0002 hs s / rs -0.11 0.0016 hs 4 week c/ s -0.24 0.0023 hs c /rs -0.29 0.02 s s / rs -0.26 0.0064 hs osteocyt es 2 week c/ s 3.8 0.0019 hs c /rs 4.4 0.0055 hs s / rs 4.1 0.0028 hs 4 week c/s -9.7 0.0017 hs c/ rs -10.4 0.0059 hs s / rs -10.1 0.0094 hs vari ables duratio n groups comparisons m.d. pvalue sig. bta 2 weeks c/ s -3.8 0.0002 hs c/ rs -3.0 0.001 hs s / rs -4.4 0.0004 hs 4 weeks c/ s -9.5 0.001 hs c/ rs -7.4 0.0001 hs s / rs -4.9 0.003 hs ta 2 weeks c/ s -5.6 0.006 hs c/ rs -8.2 0.0011 hs s / rs 3.2 0.0041 hs 4 weeks c / s 1.7 0.0001 hs c / rs 2.2 0.0021 hs s / rs 2.0 0.0087 hs bma 2 weeks c /s 0.737 0.0043 hs c/ rs 0.654 0.0062 hs s / rs 0.587 0.0028 hs 4 weeks c / s 0.231 0.007 hs c / rs 0.311 0.0028 hs s / rs 0.259 0.0091 hs table 3: lsd group differences in bone cells. table.2: lsd group differences in bone parameters j bagh college dentistry vol. 32(2), june 2020 histomorphometric 30 bone. (12) cellular processes stimulated include chemotaxis, mesenchymal cell proliferation and differentiation, angiogenesis, and synthesis of extracellular matrix, although different isoflavones compounds are closely related structurally and functionally. (13) portrayal of the recovered bone tissue is regularly performed by histological assessment with light microscopy, following standard recoloring of the example. enlightening histology is utilized to give a general appraisal of the tissue of enthusiasm, giving information with respect to cell morphology, structure and course of action inside the interface with the extracellular grid or with an embedded material.(14) in red clover oil and sponge group (gs) treated defect area showed more and thicker bone trabeculae than that of other groups. it has been reported that isoflavones compounds could increase the osteogenic effect by increasing the osteoblast cell proliferation and stimulating matrix activity. (15) a previous study (16) has been performed to evaluate the performance of isoflavones compounds as a scaffold in bone regeneration procedures to be a promoter of osteoblastic formation and is readily resorbed by osteoclasts. direct bone matrix anchorage has been shown with collagen fibers deposited in the micropores. resorption of isoflavones compounds has been reported in a rabbit model with cells having a characteristic of osteoclast cells activity. histomorphometry permits quantitative examination of histological information, to be specific with respect to length and separation, territory and number of the segments of intrigue. (17) mean values of trabecular area and number recorded in this study were higher in combination with ( rs ) group, more clearly observed in 4 weeks duration which may seem to be in line with histomorphometric results of ochiuto et al., 2007 (18) who stated that the increase in osteogenesis seen during the transition from the 14 to 30 days of observation and the total areas of the newly created bone trabeculae showed that the groups submitted to bone filling biomaterial (osteoconduction and autogenous bone graft) showed bone trabeculate area values higher than the control group of the same animal. the present study revealed that the number of osteoblasts was highest in combination (rs) group when compared to others especially in 2 weeks interval. the number of osteocytes increases with time in all studied groups especially in combination group at 4 weeks interval. these results could be explained by the direct action of red clover oil on the differentiation and maturation of osteoblasts and accelerating rate of matrix deposition and its corresponding calcification. these findings agree with bharathi & baby, 2017 (19); they found that isoflavones compounds could increase the rate of bone ossification. it is thought to affect bone metabolism by promoting the proliferation of osteoblasts and the synthesis of osteon, which leads to the inhibition of the differentiation of osteoclastlike cells. conclusion red clover oil is osteoinductive herbal material that promotes and accelerates bone healing process by an early bone formation and maturation. histmorphometric parameters for all groups showed highly significant difference in overall indicators of bone micro architectures which include trabecular area, trabecular number, bone marrow space area, osteoblasts, and osteocytes numbers. conflict of interest: none. references: 1. short ar, koralla d, deshmukh a, wissel b, stocker b, calhoun m, et, al. hydrogels that allow and facilitate bone repair, remodeling, and regeneration.j.mater.chem.2015;3(40):7818-30. 2. grosland nm, goel vk, lakes rs. techniques and applications of adaptive bone remodeling concepts. j.biomech.res.2019;4:53-75. 3. winkler t, sass fa, duda gn, schmid-bleek k. a review of biomaterials in bone defect healing, remaining shortcomings and future opportunities for bone tissue engineering: the unsolved challenge. bjr.2018;7(3):232-243. 4. lall s. evaluation of the therapeutic potential of red clover extract and red grape seed extract on human adult malignant brain tumours in vitro. phd thesis, mideast university,2017. 5. watanabe s, & uehara m.health effects and safety of soy and isoflavones. in the role of functional food security in global health. j. nutr. biochem.2019;22:379-394 6. yang y, liu g, zhang y, xu g, yi x, liang j,yu m.association between bone mineral density, bone turnover markers, and serum cholesterol j bagh college dentistry vol. 32(2), june 2020 histomorphometric 31 levels in type 2 diabetes. front.endocrino. 2018;5:235-244. 7. tareq m. histological and histomorphometrical evaluation of local application of melatonin and betatricalcium phosphate on bone healing in rats .phd thesis, college of dentistry, baghdad university,2018 . 8. jazayeri he, tahriri m, razavi m, khoshro o, fahim f, dashtim e, et al. a current overview of materials and strategies for potential use in maxillofacial tissue regeneration. mater. sci. eng.2017;70:913-929. 9. al-ghaban n.effects of glucocorticoiodsinduced osteoporosis on osseointegration of titanium implants in rabbits (histological and histomorphometical study). phd thesis, collage of dentistry, university of baghdad,2008. 10. radhi ih. evaluation the effect of hyaluronic acid on healing process of intrabony defect in rabbits (histomorphometrical and immunohistochemical studies). msc thesis, collage of dentistry, university of baghdad, 2014. 11. costa-pinto ar, reis rl, neves nm. scaffolds based bone tissue engineering: the role of chitosan. tissue eng.2011;17(5):331-347. 12. ramos gp, apel ma, morais cb, ceolato pc, schapoval ee, dall'agnol m, et al. in vivo and in vitro anti-inflammatory activity of red clover trifolium pratense dry extract. rev. bras. farmacogn.2012;22(1):176-180. 13. pilsakova l, riecanský i, jagla f. the physiological actions of isoflavone phytoestrogens.physiol.res.2010;59(5):651. 14. belill ka, settle tl, angel cr, kim sw, rothwell sw. femoral strength after induced lesions in rats (rattus norvegicus).comp.med. 2014;64(3):18. 15. gautam ak, bhargava nb, tyagi am, srivastava k,yadav dk, kumar m, et al. differential effects of formononetin and caldron on osteoblast function, peak bone mass achievement and bioavailability in rats. j.nutr.biochem. 2015;22(4):318-327. 16. merolli a, nicolais l, ambrosio l, santin ma. degradable soybean-based biomaterial used effectively as a bone filler in vivo in a rabbit. biomed mater.2010;5(1):150-158. 17. seeman e, delmas pd. bone quality—the material and structural basis of bone strength and fragility. n engl j me.2013;354(21):2250-2261 18. occhiut f, pasqueli rd, guglielmo g, palumbo d r, zangla g, samperi s, et al. effects of phytoestrogenic isoflavones from red clover (trifolium pratense l.) on experimental osteoporosis. phytotherapy research: an international journal devoted to pharmacological and toxicological evaluation of natural product derivatives. nutr.2007;21(2):130-134. 19. bharathi r, baby d. effect of phytoestrogen (isoflavones) rich soy food supplement on bone turnover among postmenopausal women. int. j. pharmacogn. phytochem.2017;6(4):79-83. الخالصة : إصالح األنسجة العظمية هي عمليه معقده متعددة الخطوات تشمل التضاعف , الهجرة الخلوية ,التفعيل والتعضية للعديد هدفال الجزء المصاب مجموعه االيزوفالفين الموجودة في زيت البرسيم األحمر يقودها باتجاه التمعدن وأعاده خلق . من انواع الخاليا تساعد في زيادة المكون الملحي للعظم ,القوه الميكانيكية , وزن العظم والكثافة العظمية بواسطة رفع مستوى مصل الفوسفات .القاعدية 300( شهور ووزن بين4-5لسليمة بعمر يتراوح بين )تم استخدام ستة وثالثين من ذكور الجرذان البيضاء ا :المواد والطرائق تم اجراء االختبار المناعي النسيجي إلظهار الببتيد المؤيد للكوالجين من النوع . ( ( ملغموالتي استخدمت في هذه الدراسة250 . االول على عينات عظميه لجميع المجموعات المدروسة والتي شوهدت خالل اسبوعين من تقدم تم دراستها التي العظم في الصفيحات العظميةاشارت النتائج النسيجية الى ترسب :النتائج التمعدن مع مرور الوقت وتم تحديده بشكل اكبر في مجموعه زيت البرسيم االحمر المغطى باإلسفنجة الماصة من مجموعه د كبير من الخاليا العظمية في مجموعه زيت كشفت النتائج النسيجية للخاليا العظمية عن وجود عد. االسفنج ومجموعه التحكم البرسيم االحمر المغطى باإلسفنجة الماصة (والتي نتجت من إعداد اكبر من الخاليا العظمية المولدة لتكوين العظم مقارنه نوع االول اظهارا إيجابيا كما أظهرت النتائج الكيمائية المناعية لنوع الببتيد المؤيد للكوالجين من ال. بالمجموعتين االسفنج والتحكم أعلى في مجموعه زيت البرسيم االحمر المغطى ايجابيا وقد أظهرت تعبيرا.متزايدا في خاليا أنسجه نخاع العظم و الخاليا العظمية . باإلسفنجة الماصة مقارنه بمجموعتين االسفنج و التحكم خصوصا في فتره األسبوعين من ضاستخدام الموضعي لزيت البرسيم األحمر يسرع في تكوين ونضج العظم ويزيد اي كشفت الدراسة أن اال االستنتاجات: . االظهار االيجابي للببتيد المؤيد للكوالجين من النوع االول في الخلل العظمي أكثر من العملية الفسيولوجية الطبيعية wasan final.doc j bagh college dentistry vol. 26(3), september 2014 immunohistochemical oral diagnosis 72 j bagh college dentistry vol. 26(3), september 2014 immunohistochemical immunohistochemical expression of mmp1 and timp1 as markers of migration in hodgkin’s and non-hodgkin’s lymphoma of the head and neck region (a comparative study) zaydoon m. kasim, b.d.s., m.sc. (1) wasan h. younis, b.d.s., m.sc., ph.d. (2) abstarct background: malignant lymphoma is a term that describes primary tumors of the lymphoreticular system, almost all of which arise from lymphocytes.mmp-1 is the most ubiquitously expressed interstitial collagenase, a subfamily of mmps that cleaves stromal collagens. it is also called collagenase-1.timps which inhibits mmp activity and thereby restrict extracellular matrix breakdown, timp-1 is a stromal factor that has a wide spectrum of functions in different tissues. material and methods: this study was performed on (68) formalin-fixed, paraffin-embedded blocks, histopathologically diagnosed as lymphoma (head and neck lesions). immunohistochemical staining of mmp1and timp1 was performed on each case of the study sample. results: the expression of mmp1was cytoplasmic, the study cases showed a 98.5% positive reaction to mmp1, score 3 was the most common and found in 60.3% of all cases.the expression of timp1was cytoplasmic, 92.6% of cases expressed positive reactions to timp1, score 1 was the most common and found in 57.4% of all cases. conclusion: this study showed for the first time the effect of mmp-1 in hl, which is considered to be as an invasive and migratory cell marker. a significant difference was found among the subtypes of nhl in relation to timp1, timp1inhibits the effect of mmp1 and as mmp1 is elevated the timp1 will be elevated too. keywords: lymphoma, hodgkin's lymphoma (hl), non-hodgkin's lymphoma (nhl), mmp1, timp1. (j bagh coll dentistry 2014; 26(3):72-78). introduction malignant lymphoma is a term describes primary tumors of the lymphoreticular system, almost all of which arise from lymphocytes. they vary greatly in their behavior, and while most prove fatal if untreated, considerable advances have been made in their management. most lymphomas arise in lymph nodes, but 30–40% develops in extranodal sites such as the stomach, though almost any organ may be primarily involved. they usually produce lymph node enlargement which may be localized or generalized, with widespread involvement of the lymphoreticular system at presentation. this latter tendency is a reflection of the normal recirculating behavior of lymphocytes. ironically, more aggressive lymphomas may remain localized, at least for a time, and tend to spread to adjacent nodes.1 lymphomas are subdivided into hodgkin’s lymphoma (hl) and non-hodgkin’s lymphoma (nhl) and are more specifically classified into subtypes of hl or nhl. hl involve the lymph nodes predominantly and only approximately 5% arise in extranodal sites, whereas 30% of nhl present in extranodal sites.2 (1)ph.d student, department of oral diagnosis, college of dentistry, university of baghdad (2)professor, department of oral diagnosis, college of dentistry, university of baghdad matrix metalloproteinases (mmps), collectively called matrixins, are proteinases that participate in ecm degradation. under normal physiological conditions, the activities of mmps are precisely regulated at the level of transcription, activation of the precursor zymogens, interaction with specific ecm components, and inhibition by endogenous inhibitors. a loss of activity control may result in diseases such as arthritis, cancer, atherosclerosis, aneurysms, nephritis, tissue ulcers, and fibrosis. tissue inhibitors of metalloproteinases (timps) are specific inhibitors of matrixins that participate in controlling the local activities of mmps in tissues.3,4 mmp-1 is the most ubiquitously expressed interstitial collagenase, a subfamily of mmps that cleaves stromal collagens. it is also called collagenase-1, and has a prominent role in collagen degradation, specifically degrades type i collagen, which is a major component of the extracellular matrix, as well as other fibrillar collagens of types ii, iii, v, ix and x. the mmp1 gene is localized on chromosome 11q22 and expressed in a wide variety of normal cells, such as stromal fibroblasts, macrophages, endothelial and epithelial cells, and in various tumor cells. it is constitutively expressed at low levels under normal physiological conditions; however, its expression may increase markedly in pathological conditions. increased expression of mmp-1 has j bagh college dentistry vol. 26(3), september 2014 immunohistochemical oral diagnosis 73 been associated with a poor prognosis in several cancers.5 mmps are counteracted by the tissue inhibitors of metalloproteinases (timps), which inhibit mmp activity and thereby restrict ecm breakdown. the balance between mmps and timps plays an important role in maintaining the integrity of healthy tissues. a balance of mmps and timps is found in various pathologic conditions including malignant conditions. tissue inhibitor of metalloproteinase 1 (timp-1) is a stromal factor that has a wide spectrum of functions in different tissues, and enhanced timp-1 expression is associated with poor clinical outcome in many cancer types also the timp-1 acts as a modulator of the survival and growth of germinal center b cells.6 this study was designed to evaluate and compare the immunohistochemical of mmp1 expression as marker for tumor cells migration, and timp1 expression as an inhibiter for mmp1, also to correlate the expression of mmp1 and timp1 in hodgkin’s and non-hodgkin’s lymphoma. materials and methods this study was performed on (68) formalinfixed, paraffin-embedded blocks, histopathologically diagnosed as lymphoma (head and neck lesions).the diagnosis of each case was confirmed by the histological examination of the hematoxylin and eosinstained sections by two experienced pathologists. histological classification was determined according to the world health organization (who) for hl (25 cases) classification and the international formulation criteria for nhl (43 cases) classification. the diagnosis of hl was confirmed by using immunohistochemical staining with cd15 and cd30, and the diagnosis of nhl was confirmed by using immunohistochemical staining with cd3, cd20 and bcl2. each case was stained by mmp1(anti-mmp1 antibody [3b6] ab2461abcom, england) and timp1(anti-timp1 antibody [102d1] ab1827abcom, england), for each antibody the following procedure is done, starting by deparaffinization of a 4µm thickness section of each block mounted on positively charged microscopic slides at 65◦ overnight, followed by dehydration, then application of hydrogen peroxidase block,antigen retrieving was perform for mmp1 and timp only by applying the slides in hot citrate buffer solution ph 6.0 (95-99 ºc) for 10 minute, followed by protein block, then the application of primary antibody and incubation (2hr for mmp1 and 6hr for timp), then the rabbit anti-mouse antibody unconjugated application, followed by goat anti-rabbit hrp conjugate application, and finally the application of dab plus chromogen then hematoxylin counterstain. the expression for all markers was evaluated semi-quantitatively. it was obtained by counting the number of tumor cells in 5 fields (using 40x objective in most represented areas of sections) and calculates the percentage of tumor cells that labeled a brown cytoplasmic. labeling index for each field was calculated using the following equation: (number of positive cells/ number of total cells); the mean value of labeling indices for the five fields was considered to be the label index for the case. the scoring categories for each antibody; 1. mmp1 ; the tumor cells labelled by antibody display a brown cytoplasmic staining pattern, immunoreactivity was classified:, (1) 1%-10%, (2) 11%-25%, (3) 26%-50%, (4) >50%.7 2. timp1 ; the tumor cells labelled by antibody display a brown cytoplasmic staining pattern, immunoreactivity was classified: (0) <5%, (1) 6%-25%, (2) 26%-50%, (3) 51%-75%, (4) 76%-100%.8 computerized statistical program (statistical package for social sciences, spss version 15) was used for the statistical analysis of data. results mmp1 expression is cytoplasmic. sixty seven cases showed positive expression (98.5%), except one negative case. tumor cells in the study sample mostly express mmp1 in “score 3” in 41 cases (60.3%). no statistically significant correlation was found between the types of lymphoma related to the scoring category for mmp1 (table1) the expression of mmp1 in hodgkin's lymphoma cases (fig 1 and 2) according to its subtypes found in table 2, all cases of hl were positive for mmp1 expression, the highest expression was found in “score 3” were 17 cases (68%) have this score. no correlation different was found between the subtype of hl related to the score of mmp1. 97.7% was the percentage of mmp1 expression in nhl cases (fig 3). the expression of mmp1 in nonhodgkin's lymphoma cases according to its subtypes found in table 3, the highest expression was found in “score 3” with 24 cases (55.8%), there was no significant different the subtype of nhl related to the score of mmp1. the expression of timp1 is cytoplasmic, the positive cases were (92.6%) 63 cases of the j bagh college dentistry vol. 26(3), september 2014 immunohistochemical oral diagnosis 74 studied sample whereas 5 cases were negative (7.4%). most of the studied cases were in “score 1” (57.4%) affected 39 cases. no statistically significant correlation was found between the hl and nhl lymphomas related to the scoring categories of timp1 expression. (table 4) the expression of timp1 in hodgkin's lymphoma cases (fig 4 and 5) according to its subtypes found in table 5, were all cases of hl were positively expressed for timp1, the highest expression was found in “score 1” with 17 cases (68%), there was no correlation between the subtype of hl regarding score of timp1 . the percentage of positive expression of timp1 in nonhodgkin's lymphoma cases (fig 6) where 88.3%, the destitution of timp1 expression according to its subtypes found in table 6, the highest expression was found in "score 1” with 22 case (51.2%), there was a significant correlation different between the subtype of nhl in relation to the scoring categories, were p-value = 0.01714, were the percentage of positive expression of timp1 in low grade and intermediate grade was 100% in comparing with 76.1% in high grade subtype. the correlation between percentages of expression of mmp1 and timp1in hl cases and nhl cases were analyzed using spearman's rank correlation coefficient (spearman's rho).in hl mmp1expression have not correlated with timp1expression while in nhl mmp1expression correlate significantly with the expression of timp1 at level 0.01. table 1: the numbers of lymphoma cases according to scoring categories for mmp1 total mmp1 lymphoma types score4 score 3 score 2 score 1 negative 25 3 17 5 0 0 no. hl 36.8% 4.4 25% 7.4% 0% 0% %total 100% 12% 68% 20% 0% 0% %type 43 9 24 8 1 1 no. nhl 63.2% 13.2 35.3% 11.7% 1.5% 1.5% %total 100% 20.9% 55.8% 18.7% 2.3% 2.3% %type 68 12 41 13 1 1 no. total 100% 17.6% 60.3% 19.1% 1.5% 1.5% % chi-squared value 1.682, d.f. 3, significance level p (2 sided) =0.6409. table 2: the expression of mmp1in hl study cases total mmp1 subtypes of hl score4 score 3 score 2 score 1 negative 1 0 1 0 0 0 no. lymphocytic rich 4% 0% 4% 0% 0% 0% %type 100% 0% 100% 0% 0% 0% %subtype 7 1 6 0 0 0 no. mixed cellularity 28% 4% 24% 0% 0% 0% %type 100% 14.3% 85.7% 0% 0% 0% %subtype 17 2 10 5 0 0 no. nodular sclerosing 68% 8% 40% 20% 0% 0% %type 100% 11.8% 58,8% 29.4% 0% 0% %subtype 25 3 17 5 0 0 no. total 100% 12% 68% 20% 0% 0% % chi-squared value 3.188, d.f. 4, significance level p (2 sided) = 0.5268 j bagh college dentistry vol. 26(3), september 2014 immunohistochemical oral diagnosis 75 table 3: the expression of mmp1 in nhl study cases total mmp1 subtypes of nhl score4 score 3 score 2 score 1 negative 6 0 4 2 0 0 no. low grade 14% 0% 9.3% 4.7% 0% 0% %type 100% 0% 66.6 33.4% 0% 0% %subtype 16 6 8 1 1 0 no. intermediate grade 37.2% 14% 18.6% 2.3% 2.3% 0% %type 100% 37.4% 50% 6.3% 6.3% 0% %subtype 21 3 12 5 0 1 no. high grade 48.8% 7% 28% 11.5% 0% 2.3% %type 100% 14.3% 57.1% 23.8% 0% 4.8% %subtype 43 9 24 8 1 1 no. total 100% 20.9% 55.8% 18.6% 2.3% 2.3% % chi-squared value 7.882, d.f. 6, significance level p (2 sided) = 0.2468 table 4: the numbers of lymphoma cases according to scoring categories for timp1 total timp1 lymphoma types score 3 score 2 score 1 score 0 negative 25 3 5 17 0 0 no. hl 36.8% 4.4% 7.4% 25% 0% 0% %total 100% 12% 20% 68% 0% 0% %hl 43 2 14 22 0 5 no. nhl 63.2% 2.9% 20.6% 32.3% 0% 11.6% %total 100% 4.6% 32.6% 51.2% 0% 11.6% %nhl 68 5 19 39 0 5 no. total 100% 7.3% 28% 57.4% 0% 7.3% % chi-squared value 2.529, d.f. 2, significance level p (2 sided) = 0.2823 table 5: the expression of timp1in hl study cases total timp1 subtypes of hl score 3 score 2 score 1 score 0 negative 1 0 0 1 0 0 no. lymphocytic rich 4% 0% 0% 4% 0% 0% %hl 100% 0% 0% 100% 0% 0% %subtype 7 1 2 4 0 0 no. mixed cellularity 28% 4% 8% 16% 0% 0% %hl 100% 14.2% 28.6% 57.2% 0% 0% %subtype 17 2 3 12 0 0 no. nodular sclerosing 68% 8% 12% 48% 0% 0% %hl 100% 11.7% 17.7% 70.6% 0% 0% %subtype 25 3 5 17 0 0 no. total 100% 12% 20% 68% 0% 0% % chi-squared value 0.944, d.f. 4, significance level p (2 sided) = 0.918 discussion the percentage of expression of mmp-1 in the study sample cases was 98.5%, this high level of mmp-1 could be attributed to the fact that lymphocytes are normally found throughout the organs and connective tissues of the body as their role in defense mechanisms of the body and these mechanisms make lymphocytes have a normal migration and invasive ability and matrix metalloproteinase activity involved in the transmigration of lymphocytes from the vascular compartment to the surrounding tissues, the malignant lymphoid cells can migrate and invade through the lymph node capsule and, so the migration and invasion capacity of lymphoma cells and cell destruction of this neoplasm probably due to the participation of proteolytic enzymes, such as metalloproteases has been explored in lymphomas and reactive lymphocytes and peritumoral stroma.9,10 j bagh college dentistry vol. 26(3), september 2014 immunohistochemical oral diagnosis 76 table 6: the expression of timp1 in nhl study cases total timp1 subtypes of nhl score 3 score 2 score 1 score 0 negative 6 0 3 3 0 0 no. low grade 14% 0% 7% 7% 0% 0% %nhl 100% 0% 50% 50% 0% 0% %subtype 16 1 10 5 0 0 no. intermediate grade 37.2% 2.3% 23.3% 11.6% 0% 0% %nhl 100% 6.2% 62.6% 31.2% 0% 0% %subtype 21 1 1 14 0 5 no. high grade 48.8% 2.3% 2.3% 32.6% 0% 11.6% %nhl 100% 4.7% 4.7% 66.7% 0% 23.9% %subtype 43 2 14 22 0 5% no. total 100% 4.6% 32.6% 51.2% 0% 11.6% % chi-squared value 12.029, d.f. 4, significance level p (2 sided) = 0.0171 a very limited number of studies have been carried out on the effect of mmp-1 on lymphoma in general and on the subtypes of lymphoma, regarding hl all cases give a positive expression (100%) with no statistical difference between subtypes of hl, "score 3" were the positive expression range between 26% to 50% was the commonest score, no available articles have been found that study the mmp-1 in hl, but the destruction of lymph node architecture seen in hl and the relationship of reed – sternberg cells with the surrounding inflammatory cells suggest a role of mmp-1 in hl. meneses-garcía et al (10) showed that all their cases of extranodal t/nk cell lymphomas was positive for mmp-1; they concluded that, mmp-1 could be contributing to the degradation of collagen matrix and, participate in the degradation of the blood vessel wall, these is in agreement with the results of the present study. the results of the present work showed that, 92.6% of all study cases were positive for timp1, this relatively high percentage of expression is expected because of the inhibiting action of timp1 on mmp1 so any increase in the expression of mmp1 lead to increase in expression of timp1in order to inhibit its action and establish a balance. oelmann et al (11) detected the timp-1 expression in the samples from 14 of the 15 patients with classic hodgkin's lymphoma, and this in agreement with the results of the present work were 100% positive expression in all case of hl, also oelmann et al (11) found no significant difference in timp-1 expression between histological subtypes of hodgkin's lymphoma, and this result was in accordance with the result of the present study were there was no significant different between subtypes of hl. pennanen et al (12) studied the immunohistochemical timp-1 expression in 57 case of hl, and they found that 33% of their cases were positive for timp1, also they reported a statistically significant difference in the expression of the protein for timp-1 between the nodular sclerosis subtype and the other subtypes of hodgkin’s lymphoma and this disagree with the results of the present study were there was no significant difference between subtypes of hl, this difference in the results could be attributed to method that they used to evaluate the positivity of the marker were they perform the presence of positive staining in reed–sternberg cells and reactive stromal cells, while the present study examined the positivity of reed-sternberg cells only, furthermore there sample include nodular lymphocyte predominant hl (22.8%) while this subtype was not present in the present study. regarding nhl, the percentage of positive expression was 88.3%, there was a significant difference between subtypes were low and intermediate grade show 100% positivity while high grade have 76.1% positive expression, kossakowska et al (13) showed expression of timp-1 in 27 out of 28 case, kossakowska et al (14) showed expression of timp-1 in 41out of 42 case, the results of these studies are relatively in agreement with the present results, were 38 out of 43 case show positive expression for timp-1. all these results conclude that elevated timp-1 expression is well correlated with tumor aggressiveness. kossakowska et al. (15) studied timp-1 expression in nhl, they show that timp-1 play a significant role in the pathogenesis of human nhl through acting as an anti-apoptotic and differentintion-promting factor, their study consisted of a wide range of different subtypes. they found that low-grade nhl express j bagh college dentistry vol. 26(3), september 2014 immunohistochemical oral diagnosis 77 relatively constant small amounts of timp-1, while high-grade tumors show more massive and variable expression of timp-1. interestingly, in situ hybridization showed timp synthesis to be localized in stromal cells surrounding the tumor. elevated timp-1 expression seemed to correlate with more extensive disease stage in high-grade nhl which was in disagreement with the results of the present study were high grade show the lowest expression rate (76.1% in comparing to 100% for intermediate and low grade subtypes) this deference could be related to the difference in the method that they used for timp-1 evaluation. citak et al 16 showed a 4% of positive expression of timp-1 in a sample consisted from 25 case of children non-hodgkin's lymphoma, with no clear differences between staining patterns of each individual nhl subtype could be detected. they explain their low timp-1 expression level may be due to the high mitotic activity of childhood nhl. the expressions of mmp1 and timp1 were significantly correlated in nhl cases this could be explain by the fact that mmp1enzyme degrade extracellular matrix proteins, and timps suppress mmp activity critical for extracellular matrix turnover associated with both physiologic and pathologic tissue remodeling. timp concentrations generally far exceed the concentration of mmps in tissue, thereby limiting their proteolytic activity to focal pericellular sites.6 in conclusion; this study for the first time showed the effect of mmp-1 in hl, which consider as an invasive and migratory cell marker, lymphomas show high migratory cells activates since all types of lymphomas could not be restricted to single lymph node and this was noted by the high expression rate of mmp-1 were it was positive in 100% for hl and 97.7% for nhl, the mmp-1 action is inhibited by timp-1 and this is confirmed by its correlation with timp1. a significant difference was found among the subtypes of nhl in relation to timp1 expression were high grade subtype showed the lowest expression in comparison with other subtypes of nhl. timp1inhibit the effect of mmp1 and as mmp1 is elevated the timp1 will be elevated too. references 1. levison da, reid r, burt ad, harrison dj, fleming s. muir’stextbook of pathology. 14th ed, london: edward arnold (publishers) ltd.; 2008. p. 189-204. 2. weber al, rahemtullah a, ferry ja. hodgkin and non-hodgkin lymphoma of the head and neck: clinical, pathologic, and imaging evaluation. neuroimaging clin n am 2003; 13: 371-92. 3. brew k, dinakarpandian d, nagase h. tissue inhibitors of metalloproteinases: evolution, structure and function. biochim biophys acta 2000; 1477: 267– 83. 4. sternlicht md, werb z. how matrix metalloproteinases regulate cell behavior. annu rev cell dev biol 2001; 17: 463–516. 5. arakaki pa, marques mr, santos mclg. mmp-1 polymorphism and its relationship to pathological processes. j biosci 2009; 34: 313–20. 6. guedez l, martinez a, zhao sh, vivero a, pittaluga s, stetler-stevenson m, raffeld m, stetler-stevenson w. tissue inhibitor of metalloproteinase 1 (timp-1) promotes plasmablastic differentiation of a burkitt lymphoma cell line: implications in the pathogenesis of plasmacytic/plasmablastic tumors. blood 2005; 105:1660-68. 7. weinrach dm, wang kl, wiley el, laskin wb. immunohistochemical expression of matrix metalloproteinases 1, 2, 9, and 14 in dermatofibrosarcomaprotuberans and common fibrous histiocytoma (dermatofibroma). arch pathol lab med 2004; 128:1136–41. 8. kuskunović s, radović s, dorić m, hukić a, babić m, tomić i, selak i. immunohistochemical expression of tissue inhibitor of metalloproteinase-1 (timp-1) in invasive breast carcinoma. bosnian j basic medical sci 2009; 9: 125-30. 9. stetler-stevenson m, mansoor a, lim m, fukushima p, kehrl j, marti g, ptaszynski k, wang j, stetlerstevenson wg. expression of matrix metalloproteinases and tissue inhibitors of metalloproteinases in reactive and neoplastic lymphoid cells. blood 1997; 89:1708-15. 10. meneses-garcía a, betancourt am, abarca jh, montes ab, roa ls, and ruíz-godoy l. expression of the metalloproteases mmp-1, mmp-2, mmp-3, mmp-9, mmp-11, timp-1 and timp-2 in angiocentricmidfacial lymphomas.world journal of surgical oncology 2008; 6:114-22. 11. oelmann e, herbst h, zuhlsdorf m, albrecht o, nolte a, schmitmann c, manzke o, diehl v, stein h, berdel we. tissue inhibitor of metalloproteinases 1 is an autocrine and paracrine survival factor, with additional immune-regulatory functions, expressed by hodgkin/reed-sternberg cells. blood 2002; 99: 258– 67. 12. pennanen h, kuittinen o, soini y, turpeenniemihujanen t. clinicopathological correlations of timp1 and timp-2 in hodgkin’s lymphoma. eur j haematol 2004; 72: 1–9. 13. kossakowska ae, urbanski sj, edwards dr. tissue inhibitor of metalloproteinases-1 (timp-1) rna is expressed at elevated levels in malignant nonhodgkin’s lymphomas. blood 1991; 77: 2475-81. 14. kossakowska ae, urbanski sj, watson a, hayden lj, edwards dr. patterns of expression of metalloproteinases and their inhibitors in human malignant lymphomas. oncology res 1993; 5:19-28. 15. kossakowska ae, urbanski sj, janowska-wieczorek a. matrix metalloproteinases and their tissue inhibitors: expression, role and regulation in human malignant non-hodgkin’s lymphomas. leuk lymphoma 2000; 39: 485–93. j bagh college dentistry vol. 26(3), september 2014 immunohistochemical oral diagnosis 78 16. citak ec, oguz a, karadeniz c. role of gelatinases (mmp-2 and mmp-9), timp-1, vascular endothelial growth factor (vegf) and microvessel density on the clinicopathological behavior of children non-hodgkin lymphoma. pediatric hematology and oncology 2008; 25: 55–66. fig 5: cytoplasmic expression of timp1 in nodular sclerosing hl case (×100) fig 5: cytoplasmic expression of timp1 in nodular sclerosing hl case (×100) figure 1: cytoplasmic expression of mmp1 in nodular sclerosing hl case (×100) figure 2: cytoplasmic expression of mmp1 in low grade nhl case. (×100) figure 3: cytoplasmic expression of mmp1 in low grade nhl case (×40) figure 4: cytoplasmic expression of timp1 in mixed cellularity hl (×100) figure 6: cytoplasmic expression of timp1 in intermediate grade nhl (×100) figure 5: cytoplasmic expression of timp1 in nodular sclerosing hl case (×100) dunia final.doc j bagh college dentistry vol. 26(3), september 2014 the relation between orthodontics, pedodontics and preventive dentistry 113 the relation between the mesio-distal crown widths of the deciduous second molars and the permanent first molars dunia a. al-dulayme, b.d.s., m.sc. (1) abstract background: this study aimed to find whether there is a relation between the mesio-distal crown diameters of the deciduous second molars and the permanent first molars in an iraqi sample from baghdad city. material and methods: the sample consisted of 54 iraqi children aged 8-9 years at the mixed dentition stage. the measurements included the mesio-distal crown width of the deciduous second molars and the permanent first molars on the study casts using digital sliding vernier. results: the results revealed absence of the side difference of the widths of teeth measured. high significant gender difference was detected for the permanent first molars and the deciduous second molars except mandibular permanent first molar. on the other hand, high significant difference was found between the maxillary and mandibular arches for the permanent first molars and the deciduous second molars except for the permanent first molar in males. a direct strong significant correlation was found between the width of the permanent first molars and the deciduous second molars. conclusion: the findings of the present study may be used as predictive factor for tooth – jaw disharmony and the possibility for the crowding in the future. keywords: mesio-distal crown width, permanent first molars, deciduous second molars. (j bagh coll dentistry 2014; 26(3):113-117). introduction odontometrics is the biometric science that studies tooth size. it is used in anthropology, archeology, dentistry and forensic dentistry (1). the mesio-distal crown diameter of teeth is an important factor which affects the alignment of teeth in the bony arches and the development of occlusion during transition of the dentition (2). several studies found that the tooth size in humans is determined by polygenic genetic factors (3-5) meaning that several genes subjected to environmental influences are involved. the way that the dental size inherited is a largely unknown process. the most important factor is hereditary. from the anthropological perspective, the determination of tooth size and form is useful for comparing the current population with previous civilizations given that variations in tooth size can be correlated with different customs, lifestyles and eating habits, as well as variations in the phylogenetic scale of human races (6,7). the most widely studied crown dimension in the literatures is the mesio-distal diameter. this dimension is important for normal occlusion as it determines the dental-bone discrepancy because dental dimension and bone dimension must be in accordance to achieve correct alignment and occlusion (8). few studies done to measure the mesio-distal width of the deciduous dentition in iraq, most of these studies frequently relate the size of deciduous teeth to those of permanent teeth (9,10). (1)lecturer. department of pop, college of dentistry, almustansiriya university. the permanent first molar is the first permanent tooth to erupt in the oral cavity at the age of six years old child distal to the second deciduous molars. it is the largest tooth of the oral cavity and the tooth of greatest biomechanical relevance (11) and it is the most dimorphic teeth of the permanent dentition (12). with regard to the deciduous second molar, it should be noted that this is the tooth with the largest mesio-distal diameter of the deciduous dentition and it is almost an exact copy of the permanent first molar, but of smaller size (11). this morphological concordance between the deciduous second molar and the permanent first molar is called isomorphism by some authors, and it can be used as a guide to predict the appearance of the permanent first molar of the same quadrant. this study aimed to find whether there is a relation between the mesio-distal crown diameters of the deciduous second molars and the permanent first molars in an iraqi sample from baghdad city. materials and methods sample out of 250 children at age of 8-9 years old examined from different primary schools in baghdad city with different socioeconomic status, only 54 children (27 males and 27 females) were selected who fitted the inclusion criteria of the present research. the exclusion criteria were the followings: 1. presence of caries or loss of dental material for any reason. 2. presence of abnormalities of size, shape, or structure. j bagh college dentistry vol. 26(3), september 2014 the relation between orthodontics, pedodontics and preventive dentistry 114 3. presence of proximal restorations. 4. teeth that had not erupt sufficiently to be able to measure the maximum mesio-distal diameter. 5. technical defects in the study models. methods the mesio-distal width of each molars were measured at the widest distance between the contact points on study dental cast obtained from alginate impressions for each child (2,13,14). a fine tipped digital sliding vernier (insize company) with an accuracy of ±0.02 mm. was used to perform the measurements held parallel to the occlusal plane. statistical analyses statistical analyses were carried out using the spss software. the descriptive statistics including means, standard deviations, maximum and minimum values of the mesio-distal width for the permanent first molars and deciduous second molars. inferential statistics included independent sample t-test to test the genders differences and paired sample t-test to compare between measurements of contra-lateral teeth. in order to study the relation between the width of the deciduous second molar and the width of the corresponding permanent first molar, the teeth were classified into 3 categories according to the mesio-distal crown diameter: normal, large, and small. these categories were based on the following considerations. normal: within the range mean size ±1 standard deviation. large: more than 1 standard deviation above the mean size. small: more than 1 standard deviation below the mean size. the percentages of the sample of molars that could be classified as normal, small, or large according to their mesio-distal crown diameters were determined separately for each of the deciduous second molars and the permanent first molars. an analysis was then performed to determine whether there was a relationship between the size of the deciduous second molar and the corresponding permanent first molar based on the above classification, this relationship was performed using pearson's correlation coefficient test. results mesio-distal crown diameters (mdcd) the descriptive statistics of the mdcd of the permanent first molars and deciduous second molars for the males and females groups in the maxillary and mandibular arches for each sides (right and left sides) were presented in (table 1). table 1: descriptive statistics of the mesio-distal width of the measured teeth in both genders teeth males (n= 27) females (n= 27) mean s.d. min. max. mean s.d. min. max. ur6 10.50 0.41 9.6 11.3 10.06 0.53 9.2 10.8 ul6 10.50 0.46 9.4 11.5 10.04 0.53 9.2 10.9 lr6 10.62 0.63 8.6 11.9 10.53 0.42 9.6 11.3 ll6 10.60 0.61 8.7 11.7 10.52 0.42 9.8 11.2 ure 9.20 0.44 8.3 9.9 8.78 0.46 8 9.6 ule 9.14 0.43 8.3 9.8 8.76 0.47 8 9.8 lre 9.79 0.58 8.7 11.4 9.45 0.51 8.3 10.5 lle 9.84 0.59 8.6 11.6 9.48 0.49 8.3 10.5 side difference (right vs. left) as presented in table 2, non-significant differences were found between the right and left sides of the maxillary and mandibular teeth using the paired sample t-test. so, the readings of the right and left sides were merged to be one reading for each tooth. table 2: sides' difference in both genders teeth males (d.f.=26) females (d.f.=26) t-test p-value t-test p-value ur6 vs. ul6 -0.082 0.936 (ns) 0.848 0.404 (ns) lr6 vs. ll6 0.586 0.563 (ns) 0.901 0.376 (ns) ure vs. ule 2.054 0.052 (ns) 0.961 0.345 (ns) lre vs. lle -1.637 0.114 (ns) -1.369 0.183 (ns) j bagh college dentistry vol. 26(3), september 2014 the relation between orthodontics, pedodontics and preventive dentistry 115 gender difference generally, males had greater mdcd than females. independent sample t-test revealed that there was a high significant difference between males and females in the maxillary permanent first molars and the deciduous second molars, while there was a non-significant genders difference in the permanent mandibular first molars (table 3). table 3: descriptive statistics and genders difference of the mesio-distal width of the measured teeth teeth males (n=54) females (n=54) total (n=108) genders difference (d.f.=106) mean s.d. mean s.d. mean s.d. t-test p-value u6 10.50 0.43 10.05 0.53 10.28 0.53 4.901 0.000 (hs) l6 10.61 0.61 10.52 0.42 10.57 0.52 0.846 0.400 (ns) ue 9.17 0.43 8.77 0.47 8.97 0.49 4.648 0.000 (hs) le 9.82 0.58 9.47 0.49 9.64 0.57 3.389 0.001 (hs) arch differences table 4 showed the comparison between the mdcd of the maxillary and mandibular permanent first molars and deciduous second molars in both genders and in overall sample using independent sample t-test. the results revealed a high significant difference between the maxillary and mandibular molars except for maxillary permanent first molars in males which showed non-significant difference. table 4: descriptive statistics and dental arches' difference of the mesio-distal width of the measured teeth in both genders and total sample genders teeth maxillary mandibular arch dimensions mean s.d. mean s.d. t-test d.f. p-value males 6 10.50 0.43 10.61 0.61 -1.056 106 0.294 (ns) e 9.17 0.43 9.82 0.58 -6.557 106 0.000 (hs) females 6 10.05 0.53 10.52 0.42 -5.204 106 0.000 (hs) e 8.77 0.47 9.46 0.49 -7.535 106 0.000 (hs) total 6 10.56 0.53 10.29 0.53 3.739 214 0.000 (hs) e 9.49 0.60 9.12 0.59 4.628 214 0.000 (hs) classification the size of the measured teeth table 5 showed the frequencies and percentages of permanent first molars and deciduous second molars that could be classified as normal, small and large according to their mdcd for the males, females and the total sample. table 5: frequency and percentage of the cases that have been classified as normal, small and large according to their mesio-distal diameter in both genders and total sample size arch tooth males females total no. % no. % no. % normal maxillary 6 44 81.48 33 61.11 74 68.52 e 38 70.37 39 72.22 75 69.44 mandibular 6 41 75.93 36 66.67 77 71.30 e 41 75.93 34 62.96 84 77.78 small maxillary 6 6 11.11 9 16.67 21 19.44 e 8 14.81 4 7.41 10 9.26 mandibular 6 5 9.26 8 14.81 14 12.96 e 8 14.81 6 11.11 8 7.41 large maxillary 6 4 7.41 12 22.22 13 12.04 e 8 14.81 11 20.37 23 21.30 mandibular 6 8 14.81 10 18.52 17 15.74 e 5 9.26 14 25.93 16 14.81 relation between the mdcd of permanent first molars and deciduous second molars the correlation between the width of the permanent first molars and the width of the j bagh college dentistry vol. 26(3), september 2014 the relation between orthodontics, pedodontics and preventive dentistry 116 deciduous second molars of each category in both genders and the overall sample was presented in table 6. generally, there was direct strong significant correlation between the width of the permanent first molars and the width of the deciduous second molars with respect to each arch table 6: relation between the mesio-distal width of the permanent first molars and deciduous second molars of each category in both genders and total sample correlation males females total normal small large normal small large normal small large r 0.962 0.922 0.927 0.857 0.821 0.818 0.915 0.760 0.660 p-value 0.000 0.009 0.032 0.000 0.003 0.002 0.000 0.011 0.014 r 0.974 0.993 0.721 0.954 0.872 0.912 0.974 0.890 0.971 p-value 0.000 0.001 0.016 0.000 0.024 0.000 0.000 0.003 0.000 discussion mesio-distal crown diameter (mdcd) also called tooth size provides significant information on human evolution and biological problems as well as in forensic and clinical dentistry. anthropologists used the mesio-distal diameter to draw the evolution of tooth size; also tooth size provides a perception of connection between populations and environmental adaptation. the relationship between tooth size and dental crowding is reported by authors as being an important factor in clinical practice (15). the mesio-distal diameter of the tooth is represented by the greatest distance between the mesial and distal points of contact using a precision caliper orientated parallel to the occlusal and vestibular surfaces. this technique described by moorrees et al. (2) to measure the mesio-distal crown diameter of the teeth, this technique has been used in many studies (5,8,12,17-19). out of 250 children examined, only 54 children were included in this study because of the high incidence of dental caries among school age children and particularly inter-proximal caries in the deciduous second and permanent first molars at this age (16). in the present study, the mesio-distal crown diameters measurements were performed on dental models obtained from alginate impressions for the selected sample (2-5,12,14). in some studies the measurements of the mesio-distal diameter of the primary and permanent teeth were performed directly in the mouth of the individual, but the measurement of maxillary molars directly in the mouth presented certain difficulties due to anatomical factors and that, in general, measurements performed intra-orally are smaller than those obtained from plaster models (19). however; other studies used both techniques (direct and indirect) in their odontometric study of deciduous dentition, demonstrating that there were no statistically significant differences between the two methods of measurements (20). from the results of present the study (tables 1 and 2), the mdcd of teeth in the right side were non-significantly larger than the left side except the mandibular second deciduous molars were the left side was larger insignificantly than the right side. this comes in accordance with other studies (2,5,9,17,21). however, tejero et al. (8) found significant differences between right and left teeth for the deciduous maxillary second molars. according to this, the left and right sides were merged and genders comparison was performed using independent sample t-test which revealed high significant genders difference for second deciduous molars and maxillary first molar. mandibular first molar showed non-significant difference; this finding agreed with the study of yuen et al. who found sexual dimorphism only for the maxillary molars (5). however, the pattern appears to be more variable because some studies did not observe sexual dimorphism for the maxillary second molars (8,23), while other studies found significant gender differences in the width of the deciduous second molars (3,16,21,24,25). comparing the mdcd between the maxillary and mandibular molars of both genders and the overall sample revealed a high significant difference between arches except for maxillary permanent first molar (table 4), and this come in accordance with many studies (9,10,22). the percentage of first permanent molars and second deciduous molars that could be classified as normal, small and large according to their mesio-distal diameter for the males, females and the overall sample respectively were presented in table 5. the highest frequency and percentage were presented for the normal size molars. applying the pearson's correlation coefficient test revealed that there was direct strong significant correlation between the width of the permanent first molars and the width of the deciduous second molars in each arch. the present finding indicated that if a dental arch had large deciduous second molars, the permanent first molars will be large also (13). this will j bagh college dentistry vol. 26(3), september 2014 the relation between orthodontics, pedodontics and preventive dentistry 117 provides the orthodontist and pedodontist with information about the size of the permanent first molars at an early age. the similarity between deciduous second molars and permanent first molars, estimated from the present study, can be used as a predictive factor of tooth-jaw size disharmony of the permanent dentition, i.e. whenever the deciduous second molars have large mesio-distal crown diameter means that the permanent first molars will be erupted large too. the conclusions that can be drawn from this study are: 1. no significant difference was detected between right and left sides for the permanent first molars and the deciduous second molars. 2. high significant difference was detected between the males and females for the permanent first molars and the deciduous second molars except mandibular permanent first molar. 3. high significant difference was found between the maxillary and mandibular arches for the first permanent molars and the second deciduous molars except for the permanent first molar in males. 4. a concordance was found between the sizes of the deciduous second molars with the size of the permanent first molars, this finding may be used as predictive factor for tooth-jaw disharmony which may result for possible crowding in the permanent dentition. references 1. puri n, pradhan k l, chandra a, sehgal v, guptae r. biometric study of tooth size in normal, crowded, and spaced permanent dentitions. am j orthod dentofac orthop 2007; 132(3): 279.e7-14. 2. moorrees cfa, thomsen so, jensen e, yen pk. mesio-distal crown diameters to the deciduous and permanent teeth in individuals. j dent res 1957; 36: 39-47. 3. lysell l, myrberg n. mesio-distal tooth size in the deciduous and permanent dentitions. eur j orthod 1982; 4:113-22. 4. bishara se, jacobsen jr, abdullah em, fernandez garcia a. comparisons of mesio-distal and buccolingual crown dimensions of the permanent teeth in three populations from egypt, mexico, and the united states. am j orthod and dentofac orthop 1989; 96(5): 416-422. 5. yuen kkw, so lly, tang elk. mesio-distal crown diameters of the deciduous and permanent teeth in the southern chinese. a longitudinal study. eur j orthod 1997; 19: 721-31. 6. lavelle cl. secular trends in different racial groups. angle orthod j 1972; 42(1):19-25. (ivsl). 7. hinton rj, smith mo, smith fh. tooth size changes in prehistoric tennessee indians. hum biol 1980; 52: 229-45. 8. tejero a, plasencia e, laniza a. estudio biometrico de la denticion temporal. rev esp ortod 1991; 21: 167-79. 9. hikmat bym. mesio-distal diameter and occlusal features in the primary dentition of 4-5 year old children from baghdadiraq. a master thesis, department of pop, college of dentistry, university of baghdad, 1989. 10. al-segar m. deciduous teeth size and jaw dimensions for iraqi children (4-5) years (cross sectional study). a master thesis, department of orthodontics, college of dentistry, university of baghdad 2003. 11. tencate ar. oral histology, development, structure & function. 3rd ed. c.v. mosby co.; 1989. 12. axelsson g, kirveskari p. crown size of permanent teeth in icelanders. acta odontol scand j 1983; 41:181-6. 13. bravo n, facal m, maroto m, barber e. relationship between mesio-distal crown diameters of permanent first molars and deciduous second molars. eur j ped dentistry 2010; 11:115-21. 14. al-dulayme da. maxillary dental arch dimensions in a sample of iraqi children at the mixed dentition stage. mustansiriya dental j 2009; 6: 349-55. 15. tatiana eda, yuri a, denise mn, glauco fv. mesiodistal and bucco-lingual crown size of deciduous teeth from a tooth bank in brazil. braz dent sci 2012; 15(1): 74-8. 16. hassan r, abbas mj. prevalence of dental caries in children attended pedodontics dental clinic in almustansiriya college of dentistry. mustansiriya dental j 2011; 8(3): 276-80. 17. margetts b, brown t. crown diameters of deciduous teeth in australian aboriginals. am j phys antrophol 1978; 48: 493-502. 18. keene hj. mesio-distal crown diameters of permanent teeth in male american negroes. am j orthod 1979; 76(1): 95-9. 19. austro md, garcia-ballesta c, pérez lejarin l, ostos mj. analisis del tamao mesio-distal en denticion temporaly & permanente en una muestra espanola. estudio comparativo con otras poblaciones. odont pediatr j 2003; 11(3): 88-93. 20. hunter ws, priest wr. errors and discrepancies in measurement of tooth size. j dent res 1960; 39(2): 405-14. 21. anderson aa. dentition and occlusion development in african american children: mesio-distal crown diameters and tooth size ratios of deciduous teeth. pediatr dent 2005; 27:121-8. 22. hattab fn, aref sa, othman m. odontometrics study of deciduous and permanent teeth in jordanians. dental news 1997; 4: 17-24. 23. axelsson g, kirveskari p. crown size of deciduous teeth in icelanders. acta odontol scand 1984; 42: 339-43. 24. marin jm, barber e, moreno jp, planells p, de nova j, costa f. study the mesio-distal diameters of the teeth in a population spanish children. pediatr odont 1993; 2 (2): 67-76. 25. facal m, de nova j, casal b, fernández, fernández a. odontométrico study of the deciduous dentition a spanish population. odont pediat 1998; 6(3): 125-30. ali f.doc j bagh college dentistry vol. 25(4), december 2013 evaluation of the effect of oral and maxillofacial surgery and periodontics 66 evaluation of the effect of er: yag laser on apical microleakage (in vitro study) anas f. mahdee, b.d.s., m.sc. (1) ali h. abbas, b.d.s., m.sc. (2) salah a. issmaeel, b.d.s., h.d.d., f.i.c.m.s. (3) abstract background: apicoectomy and retrograde filling is indicated when conventional endodontic treatment is impossible or failed to achieve apical seal. the aim of this study was to evaluate the effect of er: yag laser on apical microleakage. materials and methods: sixty extracted single-rooted teeth were used in this study. the roots were divided into six groups. group 1: apicoectomy by fissure bur, and apical cavities prepared by round bur, then cavities were filled with mta. group 2: the roots preparations and fillings were the same as group 1, then the apical areas were treated by er:yag laser. group 3: apicoectomy by fissure bur, and apical cavities prepared by ultrasound retrotip and cavities were filled with mta. group 4: the roots preparations and fillings were the same as group 3, then the apical areas were treated by er:yag laser. group 5: the roots obturation with gutta percha, then the apices were resected using er:yag laser. group 6: the roots apices were resected with er:yag laser, then the canals were obturates with gutta percha. apical microleakage was measured by methylene blue dye penetration technique. results: significant difference between the groups. group 1 shows the best apical seal, while group 5 shows the worse apical sealing ability. conclusion: apicoectomy by bur is better than apicoectomy by laser, and apical cavity prepared by bur is better than prepared by us. the use of er: yag laser in apicoectomy is preferred to be done before obturation of the root canal with gutta percha. keywords: apicoectomy, microleakage, ultrasound, er: yag laser. (j bagh coll dentistry 2013; 25(4):66-71). introduction the modes of treatment of non vital tooth should be either: extraction if the tooth is un useful and un restorable or treated by root canal therapy (rct) if the tooth is restorable and there is some evidence that small periapical cystic lesion may resolve following successful rct, however in some cases there are failure of rct or there are some obstacles to do rct, so endodontic surgery (apicoectomy) is indicated. endodontic surgery can be defined as the surgical procedure that aims to treat complications unsolved by conventional rct (1). apicoectomy means the amputation or resection of the root apex and curettage of the periapical lesion by surgical operation. there are two types of apicoectomy: conventional apicoectomy and retrograde apicoectomy. retrograde apicoectomy is indicated in some cases where there are obstacles to do conventional apicoectomy as in case the root canal can't be adequately cleansed and filled via the pulp chamber due to presence of pulp stone, calcified root canal, imperfect obturates root canal, fractured reamer, or the affected tooth is covered by a crown or a bridge (2). (1) assist. prof., department of conservative dentistry, college of dentistry, university of baghdad. (2)assist. prof.,department of oral and maxillofacial surgery. college of dentistry, university of baghdad (3) head of department of oral and maxillofacial surgery. alkarkh general hospital. also root-end resection may be the treatment of choice for teeth in which adequate nonsurgical retreatment had failed to eliminate existing periapical pathosis. thus, following the apical resection, efforts should be made to seal the rootends and prevent apical microleakage (3). in recent years there have been important innovations in the practice of endodontic surgery, these included; advances in diagnostic imaging, surgical technique, visibility of the surgical field in particular the introduction of the surgical microscope providing better and sharper visualization, introduction of laser, guided tissue regeneration and advances in retrograde filling materials (4). the permeability of dentin exposed by apicoectomy is one of the causes of endodontic surgery failure because microleakage and bacterial contamination trigger inflammation (5). pécora, et al. reported that dentin permeability decreased when smear layer was found close to the apical third of the root canal. in contrast, the removal of smear layer after apicoectomy using rotary instruments is beneficial because it promotes cementum deposition on the exposed dental surface and favors tissue repair (6). according to gagliani, et al., apical microleakage increases at increased resection angles because a larger number of dentinal tubules are sectioned and exposed. less dye penetration is found when apicoectomy is performed at 90 degrees because the apical delta j bagh college dentistry vol. 25(4), december 2013 evaluation of the effect of oral and maxillofacial surgery and periodontics 67 is more fully removed in perpendicular resections (7). removal of the last three millimeters of the root eliminate most of the apical deltas, isthmuses, and other canal irregularities, which are usually present at that specific area of the root canal system. consequently, the microorganisms harbored in these canals are removed, preventing the seepage of their byproducts to the periapical tissues. carbide burs mounted on high-speed hand-pieces provide adequate smooth surfaces for root-end resections. however, little is known if the type of bur used or the degree of smoothness after root-end resection would have a significant impact on the clinical outcome of surgical endodontic. rootend resection performed with high energy laser result in ablation of the exposed dentinal tubules, which may decrease microleakage, and increase the resistance to root resorption. the absence of vibration during the root-end resection with lasers may also prevent loss of adaptation between the gutta-percha and the canal wall (3). gouw-soares, et al. conducted a study with human teeth with apicoectomies performed with burs, er:yag laser or co2 laser. the use of lasers resulted in smoother surfaces and more homogeneous dentin fusion and recrystallization, which occluded tubules and decreased permeability (8). paghdiwala found that thermal ablation with er:yag laser can cause the dissolution of mineral components and fusion of amorphous particles, without crystallization, which results in a clean and smooth surface. the advantages of this type of laser over burs are: better visibility; accurate apical resection; no contact; removal of lesion in a shorter time by vaporization; haemostasis; no vibration or discomfort and minimal pain; and less bacterial risk of trauma to adjacent tissues (9). grgurevic, et al. tested different er:yag laser parameters for apicoectomy, and they concluded that even high-energy lasers are safe when used under water-air refrigeration (10). apicoectomy combined with retrograde filling is one of the most widely performed endodontic surgical procedures. the ideal rootend cavity preparation can be described as at least 3-5 mm deep class-i cavity, with walls parallel to the long axis of the root. this regularly shaped cavity should incorporate the root canal anatomy and should retain the retrograde filling material. the apical cavity may prepare by bur or by ultrasound (us) retrotips. the use of us-activated tips for root-end cavity preparation improves this procedure since less removal of bone tissue is required to gain proper access to the apical region. also, the resected apical segment can be smaller and less angulated (1). in addition, ultrasonically prepared root-end cavities can be more conservative than burprepared cavities, involving both the canal and the isthmus, allowing better adaptation of the retrofilling material and consequently improving the apical seal. both non-coated stainless steel and diamond-coated retrotips can be used for root-end cavity preparation (1,7,11,12). the retrofilling materials are inserted into the retrograde cavity aiming to provide apical sealing and to prevent microorganism penetration, decreasing the leakage of irritating agents in the material/canal’s wall interface and contributing to periapical repair. several retrofilling materials have been studied, such as dental amalgam, zinc oxide and eugenol-based cements (irm and super-eba), sealer 26 and mineral trioxide aggregate (mta) (13). mta has demonstrated advantages as sealing, marginal adaptation and possibility of use in the presence of humidity. mta presents excellent biological property; however, its sandy consistence makes it difficult to handle (13-15). mineral trioxide aggregate (mta) is a material developed in loma linda university, usa and represents a significant improvement over other materials used as a rootend filling materials, it is the first restorative material that allows for the overgrowth of cementum and it may facilitate the regeneration of periodontal ligament. mta is cement composed of tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite and calcium sulfate and bismuth oxide. it is very alkaline and hydrophilic requires moisture to set making dryness not necessary, it is mixed with sterile water to make a sandy consistency (16). materials and methods sixty extracted single-rooted teeth with single canal were used in this study. the roots used in this study were straight without curvature, free from cracks and fracture examined by magnification lens (x10). the calculus and debris were removed from root surface by periodontal curette, then the teeth were decoronated using a diamond disk bur, and the remaining lengths of the selected roots were 16 mm as a standard root length. the exact working length was established by passing size 10 stainless steel file until it’s tip was just out of the apical foramen and then by subtracting one mm from the measured length. the roots were instrumented with stainless steel files and the final size was 40 using conventional technique. j bagh college dentistry vol. 25(4), december 2013 evaluation of the effect of oral and maxillofacial surgery and periodontics 68 sodium hypochlorite was used for root canal irrigation after each file. then the roots were dried with paper points and finally each root was obturates with gutta percha master apical cone size 40 and accessory gutta percha cone by lateral condensation and use endofill as a sealer, and the coronal access cavity was filled with a temporary filling. the roots were divided into six groups randomly (10 roots for each group): group 1: the apex of the root was resected for 3mm length at 90 0 to the long axis of the root using high-speed hand piece and a diamond fissure bur under water cooling, and root-end cavity prepared with contra-angle low speed hand piece and a stainless steel round bur size 1 (cutting end 1mm in diameter) for 2mm depth and the cavity was filled with mta which was mixed according to manufacturer instruction. group 2: the root preparation and fillings are the same as group i. then the apical area was treated by er:yag laser (160 mj, 10 hz), just surface treatment by laser without further resection from the apex by laser. group 3: apicoectomy for 3 mm length at 90 0 to the long axis of the root using high-speed hand piece and a diamond fissure bur under water cooling, and the root-end cavity prepared by using us unit (p-max, satelec france ) with retrotip s12, 7d for 2mm depth and filled with mta. group 4: the root preparation and fillings are the same as group 3. then the apical area was treated by er:yag laser (160 mj, 10 hz), just surface treatment by laser without further resection from the apex by laser. group 5: after the roots obturation with gutta percha master apical cone size 40 and accessory gutta percha and use endofill as a sealer, in this group there is no preparation and filling of the root-end cavity. the apex of the each root was resected for 3mm length at 90 0 to the long axis of the root using er:yag laser (450 mj, 6 hz) under water cooling. group 6: after instrumentation of the root canal, the root apex was resected for 3mm length with er:yag laser (450 mj, 6 hz), then the roots were obturates with gutta percha master cone size 40 and accessory gutta percha, and the excess gutta percha were cut with a hot ash from the coronal and apical parts. in this group also there was no preparation and filling of the rootend cavity. the sixty roots were stored for 7 days in humid atmosphere and 37 0c for setting of the fillings. finally all the roots were painted with a two layers of nail varnish except 2mm from the apex, and then the roots were immersed in 2% methylene blue dye which was used as leakage indicator in an incubator for 48 hours. after that each root was washed with running tab water for about one minute. longitudinal grooves were made on both sides of each root without penetrating the walls of the pulp by using a fine diamond disc bur under water cooling and then split the root into two halves by using chisel and mallet to finish the longitudinal root sectioning. the gutta percha and mta filling was removed from the sectioned roots and the apical linear dye penetration (apical leakage) was measured by using stereomicroscope (x40) magnification with calibrated grid. the maximum apical dye leakage was measured from the tip of the root end to the deepest point where the dye was apparent in both separated halves of the root (figure1).three readings to measure each sample for apical leakage and the mean value was the documented reading. analysis of variance (anova) test was performed to test the difference between the mean of dye penetration among the six groups. statistical significance was evaluated as follows: if p-value > 0.05 = no statistically a significant difference. if p-value < 0.05 = statistically significant difference. if p-value < 0.01 = statistically a highly significant difference. the least significant difference (lsd) was used to test between groups results the descriptive statistics (mean values and standard deviation with the minimum and maximum values) are presented in table 1 and figure 2. analysis of variance (anova) test was performed to test the difference between the mean of dye penetration among the six experimental groups. statistical difference was found significant (p<0.05) among the experimental groups (table 2). the least significant difference (lsd) test was used for multiple comparisons between the six experimental groups which show variations between non-significant, significant and highly significant (table 3). 1 j bagh college dentistry vol. 25(4), december 2013 evaluation of the effect of oral and maxillofacial surgery and periodontics 69 table 1: descriptive statistic of dye penetration groups mean sd min max group1 0.156 0.0078 0.05 0.25 group2 0.597 0.02985 0.1 1.8 group3 0.314 0.0157 0.12 0.8 group4 0.735 0.03675 0.1 1.55 group5 5.55 0.2775 4.5 7.5 group6 0.38 0.019 0.2 0.5 table 2: anova test between groups figure 1: the dye penetration in split roots figure 2: bar chart for tested groups table 3: least significant difference (lsd) groups p-value sig g1&g2 p<0.05 s g1&g3 p>0.05 ns g1&g4 p<0.05 s g1&g5 p<0.01 hs g1&g6 p>0.05 ns g2&g3 p>0.05 ns g2&g4 p>0.05 ns g2&g5 p<0.01 hs g2&g6 p>0.05 ns g3&g4 p<0.05 s g3&g5 p<0.01 hs g3&g6 p>0.05 ns g4&g5 p<0.01 hs g4&g6 p<0.05 s g5&g6 p<0.01 hs discussion the selected roots for this study were straight, with standardized length, and apical foramen were completed and without resorption. in this study, three millimeters was resected from the apex, and the cutting was perpendicular to the long axis of the root because as mentioned by other studies; the removal of the last three millimeters of the root eliminate most of the apical deltas, isthmuses, and other canal irregularities, which are usually present at that specific area of the root canal system. consequently, the microorganisms harbored in these canals are removed, preventing the seepage between groups f-test p-value sig 2.284 0.046 s j bagh college dentistry vol. 25(4), december 2013 evaluation of the effect of oral and maxillofacial surgery and periodontics 70 of their byproducts to the periapical tissues (1,3, 7,17). the class i cavity preparation to accommodate the apical filling material were 2 mm depth and have parallel walls to achieve effective sealing as mentioned by other studies (13,17) . the use of ultrasound tips provides more adequate access to the apical end of the root canal. therefore, resections may be performed perpendicular to the long axis of the tooth, which preserves structure and decreases the number of sectioned dentinal tubules (15,18,19). the ultra sonic retrotip s12, 7d was used, the length of the active part of the tip was 2mm. mta filling was used in this study that it does not require a dry field, easy to handle, apply and remove excess, has good biocompatibility, results in less apical microleakage in endodontic surgeries, has excellent marginal adaptation to the walls of the cavity, and requires little force for condensation (12,19). er:yag laser has different energies for both cutting (450 mj, 6 hz) and surface treatment (160 mj, 10 hz). several in vitro studies for the assessment of microleakage were reported using staining, scanning electron microscope, bacterial activity, and many other chemical agents. dye penetration techniques still remain one of the commonest methods to test sealing ability of restorative materials. methylene blue is a commonly used dye, it was found that its leakage is comparable with that of the small bacterial product of similar molecular size (16). in the present study apical penetration of methylene blue dye at different rates was found in all evaluated specimens. group 1 had the lowest rates of dye penetration 0.156 mm when compared with the other groups, the apex was resected with diamond bur which provides adequate smooth surfaces for root-end resections, and this is in agreement with other studies. however, little is known if the type of bur used or the degree of smoothness after root-end resection would have a significant impact on the clinical outcome of surgical endodontic (3). group 1also reveals a significant difference with group 2 and group 4 (p < 0.05), this might be due to the laser energy which was used for root apex surface treatment which leads to more microleakage, this is in agreement with pashley, et al., who used different laser energies 11, 113 or 556 j/cm2. the two lowest laser energy levels increased permeability, whereas the highest produced a fully glazed surface that occluded dentinal tubules (20). such findings were confirmed by kimura, et al., who visualized areas of melted dentin under scanning electron microscopy, with partial occlusion of dentinal tubules and no cracks, fractures or thermal damage to adjacent structures or the pulp (18). group 1had a less dye penetration than group 3 and group 6 but the difference is not statistically significant (p > 0.05), according to this results it is preferred to do retrofilling after apicoectomy and this study shows the apical cavity preparation by bur shows better results from cavities prepared by us, this might be due to the us produces microcracks in the root, compromising the seal and leading to treatment failure, this is in agreement with other studies (7,16). group 2 had more dye penetration than group 3 but the difference was not statistically significant, this might be due to the effect of laser surface treatment which increases the microleakage. group 2 had less dye penetration than group 4 but also the difference is not significant, this might be due to the use of us and laser in group 4 which increases the microcracks by us and microleakage by laser. group 2 had more dye penetration than group 6 but the difference is not significant, this also might be due to the effect of laser surface treatment. group 3 shows significant difference with group 4, this also due to the use of laser for surface treatment in group 4. group 3 shows no significant difference with group 6, this is due to the use of us in this group. group 4 shows significant difference with group 6, also due to the use of us in cavity preparation in group 4, which might also due to the same reason as between group1 and group 2. in group 5 there were high statistical significant differences with other groups, after cutting of the root apices with er:yag laser affects the adaptation of the gutta-percha filling material to the root canal walls due to the rapid increase of temperature generated by laser applied to the gutta-percha and root canal sealer, and the apical seal area were removed. so this cause more shrinkage and thermal damage of the gutta percha which affect the adaptation of the gutta percha with root canal surfaces and this increase the rate of apical leakage in this group. group 6 had low rate of dye penetration 0.38 when compared with groups 2 and group 4. root-end resection performed with laser result in ablation of the exposed dentinal tubules, which may decrease microleakage, and increase the j bagh college dentistry vol. 25(4), december 2013 evaluation of the effect of oral and maxillofacial surgery and periodontics 71 resistance to root resorption (3). gouw-soares, et al, conducted a study with human teeth with apicoectomies performed with burs, er:yag laser or co2 laser. the use of lasers resulted in smoother surfaces and more homogeneous dentin fusion and recrystallization, which occluded tubules and decreased permeability (8). paghdiwala found that thermal ablation with er:yag laser can cause the dissolution of mineral components and fusion of amorphous particles, without crystallization, which results in a clean and smooth surface (9). as a conclusion; apicoectomy with class1 apical cavity preparation by bur was better than apical cavity prepared by us. retrograde filling after apicoectomy was preferred because of better results than without retrograde filling. the use of er: yag laser in apicoectomy is preferred to be done before obturation of the root canal with gutta percha. references 1bramante cm, de moraes ig, bernardineli n, et al. effect of sputter-coating on cracking of root-end surfaces after ultrasonic retrograde preparationa sem study of resected root apices and their respective impressions. acta odontol latinoam 2010; 23 nº 1 /53-57 issn 0326-4815. 2laskin dm. oral and maxillofacial surgery. vol. 2. 2009. p.143. 3sullivan j, pileggi r, varella c. evaluation of rootend resections performed by er, cr: ysgg laser with and without placement of a root-end filling material. research article. international j dentistry. 2009; article id 798786, 6 pages, doi:10.1155/2009/798786. 4eva marti-bowen, miguel penarrocha. an update in periapical surgery. med oral path oral cir bucal 2006; 11: e503-9. 5lee bs, lin cp, lin fh, lan wh. ultrastructural changes of human dentin after irradiation by nd:yag laser. lasers surg med 2002; 30(3): 24652. 6pécora jd, cussioli al, guerisoli dm, marchesan ma, sousa-neto md, brugnera a jr. evaluation of er:yag laser and edtac on dentin adhesion of six endodontic sealers. braz dent j 2001; 12(1): 27-30. 7gagliani m, taschieri s, molinari r. ultrasonic rootend preparation: influence of cutting angle on the apical seal. j endod 1998; 24(11): 726-30. 8gouw-soares s, stabholz a, lage-marques jl, zezell dm, groth eb, eduardo cp. comparative study of dentine permeability after apicoectomy and surface treatment with 9.6 microm tea co2 and er:yag laser irradiation. j clin laser med surg 2004; 22(2): 129-39. 9paghdiwala af. root resection of endodontically treated teeth by erbium: yag laser irradiation. j endod 1991; 19: 91-4. 10grgurevic j, grgurevic l, miletic i, karlovic z, krmek sj, anic i. in vitro study of the variable square pulse er:yag laser cutting efficacy for apicectomy. lasers surg med 2005; 36(5): 347-50. 11peters ci, peters ao, barbakow f. an in vitro study comparing root-end cavities prepared by diamondcoated and stainless steel ultrasonic retrotips. int endod j 2001; 34: 142-8. 12taschieri s, testori t, francetti l, delfarro m. effects of ultrasonic root-end preparation on resected root surface: sem evaluation. oral surg oral med oral pathol oral radiol endod 2004; 98: 611-8. 13roberta bosso, rodrigo colturato chagas,arturo aranda-garcia, et al. ability of different methods to fill retrograde cavities with mta. rsbo. 2012; 9(3): 280-5. 14fernandez-yanez sa, leco-berrocal mi, martinezgonzalez jm. metaanalysis of filler materials in periapical surgery. med oral patol oral cir bucal 2008; 13(3):180-5. 15torabinejad m, watson tf, pitt ford tr. sealing ability of a mineral trioxide aggregate when used as a root end filling material. j endod 1993; 19(12):591-5. 16bede syh, mohmmed saa, alaubaydi afm. comparison of microleakage in three different retrograde cavity preparations with mineral trioxide aggregate as filling material. j bagh coll dentistry 2010; 22(3): 34-8. 17daniel humberto pozza, patrícia wehmeyer fregapani, cristina braga xavier, et al. co2, er: yag and nd:yag lasers in endodontic surgery. j appl oral sci 2009; 17(6):596-9. 18kimura y, wilder-smith p, matsumoto k. lasers in endodontics: a review. international endodontic j 2000; 33 (3):173–85. 19carr gb. ultrasonic root-end preparation. dent clin north am 1997; 41:541-4. 2020pashley el, horner ja, liu m, kim s, pashley dh. effects of co2 laser energy on dentin permeability. j endod 1992; 18(6): 257-62. j bagh college dentistry vol. 28(4), december 2016 correlation between oral and maxillofacial surgery and periodontics 128 correlation between periodontal health status and salivary matrix metalloproteinase-9 levels in smoker and non-smoker chronic periodontitis patients (a comparative study) sura d. jassim, b.d.s. (a) lekaa m. ibrahim, b.d.s., m.sc. (b) abstract background: periodontal diseases are inflammatory diseases affecting the supporting tissues of the teeth. one of the leading environmental factors that are closely related not only to the risk but also to the prognosis of periodontitis is smoking. this study aimed to evaluate the influence of smoking on periodontal health status and to measure the levels of matrix metalloproteinase-9 in smokers and nonsmokers chronic periodontitis patients, also it aimed to test the correlation between the levels of matrix metalloproteinase-9 and the clinical periodontal parameters. materials and methods: five milliliters samples of un-stimulated whole saliva and full-mouth clinical periodontal recordings (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level) were obtained from forty patients of two groups (non smokers with chronic periodontitis and smokers with chronic periodontitis). all subjects were systemically healthy males, with age range (35-50) years. salivary matrix metalloproteinase-9 levels were analyzed by using enzyme-linked immunosorbent assays. results: statistical analysis revealed that probing pocket depth and clinical attachment level were higher in smokers than non smokers, while there were decreases in the numbers of bleeding sites in smoker when compared with non smoker subjects. salivary matrix metalloproteinase-9 levels were significantly higher in smoker with chronic periodontitis patients than their non smoker counterparts. conclusion: salivary matrix metalloproteinase-9, as a biomarker, could reflect the increased periodontal tissue destruction due to the smoking. keywords: non-smokers, smokers, salivary matrix metalloproteinase-9, periodontal health status. (j bagh coll dentistry 2016; 28(4):128-133) introduction chronic periodontitis is an infectious inflammatory disease characterized by the destruction of the tooth supporting structures (1). periodontitis is a multifactorial irreversible and cumulative condition, initiated and propagated by bacteria and host factors (2). several factors, including smoking, socioeconomic status and stress have been identified as potential risk factors for periodontitis (3). tobacco smoking is one of the most important risk factors associated with the destruction of the alveolar bone and loss of attachment in patients with periodontitis (4). several studies on the relationship between periodontal diseases and tobacco use have consistently shown that the non smokers are two to six times less likely to develop periodontitis than smokers (5, 6). smoking as an environmental factor has been suggested to interact with host cells and affect inflammatory responses to the microbial challenge (4).the effects of smoking include alterations in vascular function, monocyte /neutrophil activities, release of cytokine and inflammatory mediators and antibody production (7-10). (a) m.sc. student, department of periodontics, college of dentistry, university of baghdad. (b) professor, department of periodontics, college of dentistry, university of baghdad. biomarkers are defined as cellular, molecular, biochemical or genetic changes by which a normal, abnormal or simply biologic process can be noticed or monitored (11). matrix metalloproteinases (mmps) represent a superfamily of proteases acting not only in physiological development and tissue remodeling, but also in pathological tissue destruction (12). host cells are stimulated by pathogens in microbial dental plaque by increasing their mmp release, which is one of the indirect mechanisms of tissue destruction seen during periodontitis (13). matrix metalloproteinase-9, gelatinase b, is secreted mainly by neutrophils and it is capable of degrading denatured interstitial collagens, gelatins, laminin, elastin, fibronectin and collagens type iv and type vii (14). generally smokers associated with higher gcf concentrations of mmp-9 than non-smokers (15). subjects and methods human subjects consist of 40participants males with age range (35-50) years, attending department of periodontology at college of dentistry / university of baghdad. the sample population divided into two groups: 20 non smokers subjects with chronic periodontitis and 20 smokers subjects with chronic periodontitis. j bagh college dentistry vol. 28(4), december 2016 correlation between oral and maxillofacial surgery and periodontics 129 all subjects were in a good general health, with no history of systemic disease, no history of regular use of mouth washes and did not take medication (eg: anti inflammatory or antimicrobial therapy within the previous 3 month). saliva samples collection five milliliter sample of un-stimulated whole saliva was collected from each patient before the clinical periodontal examination. the sample was collected after an individual was asked to rinse his mouth thoroughly with water to insure the removal of any possible debris or contaminating materials and waiting for 1-2 minutes for water clearance. salivary samples were collected at least 1 hour after the last meal and stored at -20 c˚ till being assessed for matrix metalloproteinase-9 levels. clinical periodontal examination clinical periodontal parameters included assessment of plaque index (pli) (16), gingival index (gi) (17), bleeding on probing (bop) (18), probing pocket depth (ppd) and clinical attachment level (cal).we use scales for the measurements of ppd and cal with the following scores {ppd: score (0) = 0-2 mm , score (1) >2-4 mm ,score (2) >4-6mm and score (3) >6mm };{cal: score (1)= 1-2 mm , score (2) >2-4 mm , score (3) >4-6 mm and score (4) >6 mm). biochemical analysis the biochemical analysis includes measuring the levels of matrix metalloproteinase-9 in saliva by enzyme-linked immunosorbent assays (elisa), using (quantikine r&d, usa) kit. statistical analyses the study variables were statistically analyzed using statistical process for social science (spss version 20) by using mean, standard deviation, percentage, student t-test, chi-square test and pearson's correlation coefficient, the level of significant was accepted at p ≤ 0.05 and highly significant when p ≤ 0.001. results a-clinical periodontal parameters the results of this study revealed that smoker and non smoker chronic periodontitis groups showed non significant differences in pli and gi as shown in table (1). the bop results showed that smoker chronic periodontitis group had less numbers of sites with bleeding on probing than non smoker chronic periodontitis group, chi-square test revealed highly significant difference between groups (p<0.001) as shown in table (2). there were increasing in total numbers of ppd scores (2and 3) in smoker chronic periodontitis group compared to non smoker group, while scores (0 and 1) were decreased in smoker group. chi-square test revealed significant difference in ppd between groups as shown in table (3). the results of this study revealed increase in cal (score 3 and 4) in smoker chronic periodontitis group when compared with non smoker group, chi-square test showed significant difference between groups as shown in table (4). table 1: descriptive statistics (mean±sd) and inter group comparison of (pli, gi and mmp-9) between smokers chronic periodontitis and non smokers chronic periodontitis groups pli mean ± sd t-test p value gi mean ± sd t-test p value mmp-9 (ng/ml) mean ± sd t-test p value non smokers chronic periodontitis group 1.88± 0.51 0.172 0.864 1.78± 0.42 1.856 0.071 32.53± 1.49 2.936 0.006 smokers chronic periodontitis group 1.85± 0.49 1.55± 0.38 33.75± 1.14 table 2: number and percentage (in sites) of bleeding on probing scores and chi-square test of smokers and non smokers chronic periodontitis groups scale non smokers chronic periodontitis group smokers chronic periodontitis group x2 p value no. % no. % score 0 483 25.6% 731 39.0% 77.1 < 0.001 score 1 1405 74.4% 1145 61.0% j bagh college dentistry vol. 28(4), december 2016 correlation between oral and maxillofacial surgery and periodontics 130 table 3: number and percentage (in sites) of ppd scores and chi-square test of smokers and non smokers chronic periodontitis groups scale non smokers chronic periodontitis group smokers chronic periodontitis group x2 p value no % no % score 0 80 4.2% 66 3.5% 14.9 0.002 score 1 951 50.4% 842 44.9% score 2 853 45.2% 962 51.3% score 3 4 0.2% 6 0.3% table 4: number and percentage (in sites) of cal scores and chi-square test of smokers and nonsmokers chronic periodontitis groups scale non smokers chronic periodontitis group smokers chronic periodontitis group x2 p value no % no % score 1 70 3.71% 50 2.67% 8.77 0.032 score 2 869 46.02% 830 44.24% score 3 939 49.74% 975 51.97% score 4 10 0.53% 21 1.12% b-biochemical parameters the mean and standard deviation of mmp-9 in non smokers chronic periodontitis group was (32.53± 1.49) ng/ml ,while it was (33.75± 1.14) ng /ml for smokers chronic periodontitis group , statistical analysis using student t-test showed significant difference between non smokers chronic periodontitis and smokers chronic periodontitis groups as shown in the table (1). c-correlation between clinical and biochemical parameters there were no correlations between the levels of the salivary mmp-9 and pli in smokers and non-smokers chronic periodontitis groups, while there was significant positive correlation between gi and mmp-9 levels in non smokers group. highly significant positive correlations were found between mmp-9 levels and bop in smokers and non smokers groups as shown in table (5).there were highly significant positive correlations between mmp-9 levels and ppd scores (2 and 3) in smokers and non smokers groups, also there were highly significant positive correlations between mmp-9 levels and cal scores (3 and 4) in smokers and nonsmokers groups as shown in table (6). table 5: correlations of (pli, gi and bop) and mmp-9 levels in smokers and non smokers chronic periodontitis groups non smoker chronic periodontitis smoker chronic periodontitis r p value r p value pli 0.043 0.856 0.083 0.728 gi 0.453 0.031 0.381 0.125 bop 0.807 ˂ 0.001 0.652 0.001 table 6: correlations of (ppd and cal) scores and mmp-9 levels in smokers and non smokers chronic periodontitis groups groups ppd cal score 0 score 1 score 2 score 3 score 1 score 2 score 3 score 4 non smokers chronic periodontitis r 0.402 0.447 0.954 0.897 0.174 0.201 0.660 0.829 p 0.079 0.064 <0.001 <0.001 0.231 0.198 0.001 ˂0.001 smokers chronic periodontitis r 0.372 0.531 0.960 0.838 0.148 0.222 0.742 0.696 p 0.106 0.082 <0.001 <0.001 0.267 0.174 ˂0.001 ˂0.001 discussion in the present study non significant difference in pli was found between smokers and non smokers groups this result agrees with calsina et al (19), while it disagrees with mokeem et al (20). http://www.ncbi.nlm.nih.gov/pubmed/?term=mokeem%20sa%5bauthor%5d&cauthor=true&cauthor_uid=24984667 j bagh college dentistry vol. 28(4), december 2016 correlation between oral and maxillofacial surgery and periodontics 131 the reason for this result is that the amount of plaque on the teeth surfaces is mainly depend on personal oral hygiene and frequency of teeth brushing rather than smoking status. although non significant difference was found in gi between smokers and non smokers groups, the results of this study showed that the non smokers group associated with higher gi than smokers group. this general increase in gi agrees with preber and bergstrom (21), while it disagrees with kolte et al (22). according to this study non smokers chronic periodontitis group associated with more bleeding sites than smokers chronic periodontitis group with highly significant difference , this finding was in agreement with calsina et al (19) and in disagreement with nassrawin (23) . the reasons for the suppression of the gingival inflammatory reaction and bleeding on probing in smokers are the products of tobacco smoke that interfere with the vascular inflammatory response. it was found that nicotine caused a severe drop in blood flow rates in spite of greatly increased pressure within the vascular system (24), also tobacco use was associated with reduced permeability of peripheral blood vessels (25). vasoconstriction of peripheral vessels caused by smoking lead to inhibition of the vascular properties of inflammation such as redness, bleeding and exudation. also smoking has been shown to affect oral polymorphonuclear (pmn) leukocytes, indicating a defect in pmn leukocytes -function (26, 27). thus, smoking seems to influence both cellular and vascular properties of the inflammatory reaction. the suppression influence of smoking on the inflammatory reaction might indicate an impairment of the defense mechanisms within the tissues and render them more susceptible to plaque infection. vasoconstriction of the gingival vessels of smokers might be attributed to the actions of nicotine-stimulated adrenaline and nor adrenaline on α1-adrenergic receptors. although some evidences support this theory in animal models, the evidence that supports this hypothesis in humans is not founded (28). according to results of this study, there were increase in ppd scores (2&3) in smokers chronic periodontitis group compared with non smokers chronic periodontitis group, while non smokers chronic periodontitis group had more sites of scores (0&1) . this general increase in ppd in smokers group compared with non-smokers group was in agreement with many studies (29, 30) and it was in disagreement with kubota et al (31). studies had shown that nicotine suppresses mineralized nodule formation (32). additionally, osteoclast differentiation is enhanced by nicotine through macrophage colony-stimulating factor and prostaglandin e2 production, which are produced by nicotine-treated osteoblasts (33). it was found that nicotine concentrations of gingival crevicular fluid could be nearly 300 times more than that of plasma concentrations in smokers (34), also nicotine bound to root surface and in vitro studies showed that it could be stored and released from periodontal fibroblasts. nicotine could inhibit fibroblast attachment and integrin expression, fibronectin and collagen production and increased fibroblast collagenase activity (35). according to the results of this study, there were increase in cal scores (3 and 4) in smokers chronic periodontitis group when compared with non smokers chronic periodontitis group.this general increase in cal in smokers group compared with non-smokers group was in agreement with mokeem et al (20); nassrawin (23).the reason for this increased cal could be derived from the same explanations of increased ppd in smokers which were mentioned previously as both of them could reflect the progress and severity of periodontal tissue destruction. this study showed that mmp-9 levels were higher in smoker chronic periodontitis group than non smoker chronic periodontitis group , this finding was in agreement with victor et al (15). this increase in mmp-9 concentrations of smokers also shown at systemic levels, as plasma mmp-9 levels of smokers were 6.45 times higher than that of non-smokers (36). cigarette smoke contains high concentrations of reactive oxygen species (ros), ros can activate proinflammatory signaling pathways and induce bone resorption (37, 38). studies had shown that nicotine shift neutrophil function towards destructive activities (39), and induce the expression of mmps in osteoblasts (40). smoking also change the balance between tissue inhibitor of matrix metalloprotienase (timp-1) and mmps, as mmp-9/timp-1 ratios were higher in smoker chronic periodontitis than non-smoker chronic periodontitis group (41). additionally, this study found that the mmp-9 levels directly correlated with the clinical periodontal parameters (bop, ppd and cal).these results were in agreement with rai et al (42); isaza-guzman et al (43).the mean mmp9 levels in pocket sites were higher when the test site had a pocket ≥ 4 mm than in sites with a ppd of < 4 mm (44). http://www.ncbi.nlm.nih.gov/pubmed/?term=preber%20h%5bauthor%5d&cauthor=true&cauthor_uid=3458283 http://www.ncbi.nlm.nih.gov/pubmed/?term=bergstr%c3%b6m%20j%5bauthor%5d&cauthor=true&cauthor_uid=3458283 j bagh college dentistry vol. 28(4), december 2016 correlation between oral and maxillofacial surgery and periodontics 132 consequently, mmp-9 concentrations of saliva could reflect the degree of periodontal inflammation and tissue breakdown. references 1. tonetti ms, claffey n. european workshop in periodontology group c. advances in the progression of periodontitis and proposal of definitions of a periodontitis case and disease progression for use in risk factor research. group c consensus report of the 5th european workshop in periodontology. j clin periodontol 2005; 32: 210–3. 2. kinane df. causation and pathogenesis of periodontal disease. periodontology 2000 2001; 25: 8-20. 3. albandar jm. global risk 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n, katono t, sato s, et al. nicotine and lipopolysaccharide stimulate the formation of osteoclast-like cells by increasing macrophage colony-stimulating factor and prostaglandin e2 production by osteoblasts. life sciences 2006; 78: 1733–40. http://www.ncbi.nlm.nih.gov/pmc/articles/pmc3172997/ http://www.ncbi.nlm.nih.gov/pmc/articles/pmc3172997/ http://www.ncbi.nlm.nih.gov/pubmed/?term=calsina%20g%5bauthor%5d&cauthor=true&cauthor_uid=12390575 http://www.ncbi.nlm.nih.gov/pubmed/?term=ram%c3%b3n%20jm%5bauthor%5d&cauthor=true&cauthor_uid=12390575 http://www.ncbi.nlm.nih.gov/pubmed/?term=echeverr%c3%ada%20jj%5bauthor%5d&cauthor=true&cauthor_uid=12390575 http://www.ncbi.nlm.nih.gov/pubmed/?term=mokeem%20sa%5bauthor%5d&cauthor=true&cauthor_uid=24984667 http://www.ncbi.nlm.nih.gov/pubmed/?term=vellappally%20s%5bauthor%5d&cauthor=true&cauthor_uid=24984667 http://www.ncbi.nlm.nih.gov/pubmed/?term=preethanath%20rs%5bauthor%5d&cauthor=true&cauthor_uid=24984667 http://www.ncbi.nlm.nih.gov/pubmed/?term=hashem%20mi%5bauthor%5d&cauthor=true&cauthor_uid=24984667 http://www.ncbi.nlm.nih.gov/pubmed/?term=hashem%20mi%5bauthor%5d&cauthor=true&cauthor_uid=24984667 http://www.ncbi.nlm.nih.gov/pubmed/?term=al-kheraif%20aa%5bauthor%5d&cauthor=true&cauthor_uid=24984667 http://www.ncbi.nlm.nih.gov/pubmed/?term=anil%20s%5bauthor%5d&cauthor=true&cauthor_uid=24984667 http://www.ncbi.nlm.nih.gov/pubmed/?term=preber%20h%5bauthor%5d&cauthor=true&cauthor_uid=3458283 http://www.ncbi.nlm.nih.gov/pubmed/?term=bergstr%c3%b6m%20j%5bauthor%5d&cauthor=true&cauthor_uid=3458283 http://www.ncbi.nlm.nih.gov/pubmed/?term=clarke%20ng%5bauthor%5d&cauthor=true&cauthor_uid=6947180 http://www.ncbi.nlm.nih.gov/pubmed/?term=shephard%20bc%5bauthor%5d&cauthor=true&cauthor_uid=6947180 http://www.ncbi.nlm.nih.gov/pubmed/?term=hirsch%20rs%5bauthor%5d&cauthor=true&cauthor_uid=6947180 http://www.ncbi.nlm.nih.gov/pubmed/?term=torrungruang%20k%5bauthor%5d&cauthor=true&cauthor_uid=15857097 http://www.ncbi.nlm.nih.gov/pubmed/?term=nisapakultorn%20k%5bauthor%5d&cauthor=true&cauthor_uid=15857097 http://www.ncbi.nlm.nih.gov/pubmed/?term=sutdhibhisal%20s%5bauthor%5d&cauthor=true&cauthor_uid=15857097 http://www.ncbi.nlm.nih.gov/pubmed/?term=sutdhibhisal%20s%5bauthor%5d&cauthor=true&cauthor_uid=15857097 http://www.ncbi.nlm.nih.gov/pubmed/?term=tamsailom%20s%5bauthor%5d&cauthor=true&cauthor_uid=15857097 http://www.ncbi.nlm.nih.gov/pubmed/?term=rojanasomsith%20k%5bauthor%5d&cauthor=true&cauthor_uid=15857097 http://www.ncbi.nlm.nih.gov/pubmed/?term=vanichjakvong%20o%5bauthor%5d&cauthor=true&cauthor_uid=15857097 http://www.ncbi.nlm.nih.gov/pubmed/?term=sugaya%20a%5bauthor%5d&cauthor=true&cauthor_uid=15946696 https://www.infona.pl/contributor/5@bwmeta1.element.elsevier-6aa4cbb4-ead6-33d2-bd22-0f683ac85fb6/tab/publications https://www.infona.pl/contributor/5@bwmeta1.element.elsevier-6aa4cbb4-ead6-33d2-bd22-0f683ac85fb6/tab/publications j bagh college dentistry vol. 28(4), december 2016 correlation between oral and maxillofacial surgery and periodontics 133 34. chen x, wolff l, aeppli d, guo z, luan w, baelum v, fejeskov o. cigarette smoking, salivary/gingival crevicular fluid cotinine and periodontal status. a 10year longitudinal study. j clinical periodontol 2001; 28: 331-9. 35. alpar b, leyhausen g, sapotnick a, gunay h, geurtsen w. nicotine-induced alterations in human primary periodontal ligament and gingiva fibroblast cultures. clinical oral investigations 1998; 2: 40-6. 36. söder b, airila månsson s, söder po, kari k, meurman j.levels of matrix metalloproteinases-8 and -9 with simultaneous presence of periodontal pathogens in gingival crevicular fluid as well as matrix metalloproteinase-9 and cholesterol in blood. j periodontal res 2006; 41(5): 411-7. 37. mody n, parhami f, sarafian ta, demer ll. oxidative stress modulates osteoblastic differentiation of vascular and bone cells. free radic biol med 2001; 31: 509-9. 38. d’aiuto f, nibali l, parkar m, patel k, suvan j, donos n. oxidative stress, systemic inflammation, and severe periodontitis. j dent res 2010; 89: 1241-6. 39. johnson gk, guthmiller jm. the impact of cigarette smoking on periodontal disease and treatment. periodontol 2000 2007; 44: 178-94. 40. denlinger lc, fisette pl, garis ka, kwon g, vazquez-torres a, et al. regulation of inducible nitric oxide synthase expression by macrophage purinoreceptors and calcium. j biological chemistry1996; 271: 337–42. 41. ozçaka o, biçakci n, pussinen p, sorsa t, köse t, buduneli n. smoking and matrix metalloproteinases, neutrophil elastase and myeloperoxidase in chronic periodontitis. oral dis 2011; 17(1): 68-76. 42. rai b, kharb s, jain r, anand sc. biomarkers of periodontitis in oral fluids. j oal sci 2008; 50(1): 536. 43. isaza-guzm´an d m,arias-osorio c, mart´ınezpab´on mc, tob´on-arroyave si .salivary levels of matrixmetalloproteinase (mmp)-9 and tissue inhibitor of matrix metalloproteinase (timp)-1: a pilot study about the relationship with periodontal status and mmp-9-1562c/t gene promoter polymorphism. arch oral biol 2011; 56(4): 401-11. 44. yakob m. associations between oral biofilm, periodontal disease, and systemic health: with a focus on atherosclerosis and breast cancer. doctorate thesis, karolinska institutet and faculty of medicine, university of helsinki, 2012. http://www.ncbi.nlm.nih.gov/pubmed/?term=s%c3%b6der%20b%5bauthor%5d&cauthor=true&cauthor_uid=16953818 http://www.ncbi.nlm.nih.gov/pubmed/?term=airila%20m%c3%a5nsson%20s%5bauthor%5d&cauthor=true&cauthor_uid=16953818 http://www.ncbi.nlm.nih.gov/pubmed/?term=s%c3%b6der%20po%5bauthor%5d&cauthor=true&cauthor_uid=16953818 http://www.ncbi.nlm.nih.gov/pubmed/?term=kari%20k%5bauthor%5d&cauthor=true&cauthor_uid=16953818 http://www.ncbi.nlm.nih.gov/pubmed/?term=kari%20k%5bauthor%5d&cauthor=true&cauthor_uid=16953818 http://www.ncbi.nlm.nih.gov/pubmed/?term=meurman%20j%5bauthor%5d&cauthor=true&cauthor_uid=16953818 http://www.ncbi.nlm.nih.gov/pubmed/?term=oz%c3%a7aka%20o%5bauthor%5d&cauthor=true&cauthor_uid=20646231 http://www.ncbi.nlm.nih.gov/pubmed/?term=bi%c3%a7akci%20n%5bauthor%5d&cauthor=true&cauthor_uid=20646231 http://www.ncbi.nlm.nih.gov/pubmed/?term=pussinen%20p%5bauthor%5d&cauthor=true&cauthor_uid=20646231 http://www.ncbi.nlm.nih.gov/pubmed/?term=sorsa%20t%5bauthor%5d&cauthor=true&cauthor_uid=20646231 http://www.ncbi.nlm.nih.gov/pubmed/?term=k%c3%b6se%20t%5bauthor%5d&cauthor=true&cauthor_uid=20646231 http://www.ncbi.nlm.nih.gov/pubmed/?term=k%c3%b6se%20t%5bauthor%5d&cauthor=true&cauthor_uid=20646231 http://www.ncbi.nlm.nih.gov/pubmed/?term=buduneli%20n%5bauthor%5d&cauthor=true&cauthor_uid=20646231 3. majida f.doc j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 15 an evaluation of the solubility of four endodontic sealers in different solvents (an in vitro study) noor hayder fadhil, b.d.s.(1) majida k. al-hashimi, b.d.s., m.sc.(2) abstract background: complete removal of filling material from the root canal is an essential requirement for endodontic retreatment. the purpose of the present study is to evaluate and compare the dissolving capabilities of various solvents (xylene, eugenate desobturator, eucalyptol, edta and distilled water (as a control)) on four different types of sealer (endofill, apexit plus, ah plus and endosequence bioceramic sealer). materials and method: eighty samples of each sealer were prepared according to the manufacturers' instructions and then divided into ten groups (of 8 samples) for immersion in the respective solvents for 2 and 5 min immersion periods. each sealer specimen was weighed to obtain its initial mass. the specimens were immersed in the tested solvents for 2 and 5 min, followed by rinsing with double distilled water and blotted dry with an absorbent paper, then they were reweighed to determine its final mass. the mean of weight loss was determined for each material in each solvent during the specified immersion period, and the values were subjected to statistical analysis. results: clear differences were shown in the solubility profile of these root canal sealers in the tested solvents. the result of the present study shows that xylene had the greatest capacity for dissolving endofill, apexit plus and ah plus. eugenate desobturator, eucalyptol and edta showed a highly significant dissolving capability on these sealers with variations between these subgroups; endosequence bc sealer is insoluble in these tested solvents. regarding the immersion time, higher values of solubility were obtained at 5 min than that at 2 min immersion time. conclusion: the results showed that xylene, eugenate desobturator, eucalyptol and edta can be used for the removal of endofill, apexit plus and ah plus during endodontic retreatment with variations between these subgroups; d.w (control group) showed the least capacity for dissolving these sealers. endosequence bc sealer is insoluble in the tested solvents. keywords: endofill, apexit plus, ah plus, endosequence bc sealer, xylene, eugenate desobturator, eucalyptol, edta, endodontic retreatment, solvents. (j bagh coll dentistry 2015; 27(4):15-20). introduction teeth with pulpal and periradicular disease are usually treated with root canal treatment. although, the success rate of root canal treatment is up to 86 to 93%, failure in endodontic treatment may be expected. the main causes of root canal failure are improper cleaning and filling of the root canal system, procedural errors, or the lack of an efficient hermetic sealing, which enables the survival of bacteria inside dentinal tubules, apical ramifications, accessory and secondary canals(1). retreating previously filled root canal requires that antimicrobial irrigants and medications gain access to all anatomical ramifications of the canal system which may be harboring microorganisms and organic matter. it is desirable that all materials employed are amenable to complete removal during retreatment. failure to remove all debris from the canal may result in the survival of bacterial infection, which may result in root canal failure (2, 3). the most commonly used obturation material in endodontic treatment is gutta-percha in conjunction with a variety of sealers. to allow endodontic retreatment when indicated, the root filling materials should be retreatable/ retrievable(4). (1)m.sc. student. department of conservative dentistry, college of dentistry, university of baghdad. (2)professor. department of conservative dentistry, college of dentistry, university of baghdad. various removal methods are available for endodontic retreatment, including mechanical instrumentation alone or in combination with the solvents or heat. while methods for removing the gutta-percha have been well researched, far less interest has been focused on the removal of sealer from root canal walls, and from root ramification where they remain inaccessible to mechanical techniques of removal. in such cases, solvents are essential for the thorough cleaning of filling material/debris to allow effective disinfection of the root canal system(5). the ‘wicking technique’ is essential in removing residual gutta-percha and sealer and should always be the final step during guttapercha removal. wicking technique involve flushing the root canal with a solvent up to the level of pulp chamber followed by drying it with paper points. paper points aid in removal of residual materials by drawing dissolved materials into and then out of the shaped canal(1,6). chloroform and xylene have the ability to dissolve most root filling materials. as a result of concerns about the carcinogenicity of chloroform, researchers and clinicians have an interest in finding alternative solvents. some solvents act as safe alternative to chloroform such as orange oil and eucalyptol with ability to dissolve root filling materials(7). several commercially available endodontic sealers present with distinct physicochemical j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 16 characteristics, which may determine and influence the clinical efficiency of the solvents. therefore, in the present study we evaluated the dissolving capabilities of various solvents on different types of sealer. materials and methods for this in vitro study, standardized metal ring (8 mm in diameter and 2 mm in height) were used to prepare the sealer specimens. eighty samples were prepared from each sealer material. • group a: 80 samples of endofill sealer (zinc oxide eugenol-based sealer). • group b: 80 samples of apexit plus sealer (calcium hydroxide-based sealer). • group c: 80 samples of ah plus sealer (epoxy resin based sealer). • group d: 80 samples of endosequence bc sealer (calcium phosphate silicate-based sealer). each group divided into ten subgroups (of 8 samples) for immersion in the solvents for 2 min and 5 min. sealers prepared according to the manufacturers' instructions. after loading the molds, they transferred to a humidifier with 80% relative humidity and 37±1˚c temperature for 72 hours (endosequence bc sealer remained in humidity for 10 days to be completely set). then they removed from the humidifier and excess material trimmed with a scalpel blade to the surface level of the mold(8). every sample removed from the mold in such a way that all surfaces of each sample were freely accessible to the liquid. the samples weighed in grams (up to four decimal places) by using a digital analytical scale (sartorius analytical, germany) prior to the immersion in the solvent to get the initial weight. the sealer samples immersed in the respective solvents (20 ml) for 2 and 5 minute immersion periods. each sample used for just one immersion period to enhance the accuracy of the measurements. after the specific immersion period, the samples removed from the container, rinsed with 100 ml of double-distilled water in order to neutralize the solvent action. after that, the specimens blotted dry with an absorbent paper to remove the loose debris of decomposition(8). the sealer samples allowed to dry in an oven for 24 hours at 37±1˚c. thereafter, they weighed to obtain the final weight. lost from each sample calculated by the difference between the final weight and the original weight of the sample. results the descriptive statistics (mean and standard deviation) and t-test results of weight loss (g) for each sealer presented in the tables (1,2,3,4). table 1: descriptive statistics and t-test results of weight loss (g) for group a (endofill sealer). solvents groups descriptive statistics difference mean ±s.d. mean ±s.d. mean difference t-test d.f. p-value xylene wa-w2 0.274 0.003 0.259 0.003 0.015 37.543 7 0.000 wb-w5 0.274 0.002 0.255 0.005 0.019 15.208 7 0.000 diff. 0.0146 0.0012 0.0190 0.0035 -0.004 -3.336 14 0.005 eugenate desobturator wa-w2 0.275 0.003 0.263 0.003 0.011 18.940 7 0.000 wb-w5 0.274 0.001 0.255 0.003 0.020 18.291 7 0.000 diff. 0.0112 0.0016 0.0196 0.0030 -0.008 -6.863 14 0.000 edta wa-w2 0.272 0.003 0.266 0.003 0.007 25.382 7 0.000 wb-w5 0.274 0.002 0.264 0.003 0.010 26.101 7 0.000 diff. 0.0066 0.0007 0.0100 0.0011 -0.003 -7.280 14 0.000 eucalyptol wa-w2 0.274 0.002 0.270 0.002 0.004 12.503 7 0.000 wb-w5 0.275 0.001 0.266 0.001 0.009 34.942 7 0.000 diff. 0.0042 0.0010 0.0092 0.0007 -0.005 -11.520 14 0.000 distilled water wa-w2 0.275 0.001 0.275 0.001 0.0001 1.930 7 0.095 wb-w5 0.275 0.001 0.275 0.001 0.0001 7.514 7 0.000 diff. 0.0001 0.0001 0.0001 0.0001 0.000 -2.016 14 0.063 j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 17 table 2: descriptive statistics and t-test results of weight loss (g) for group b (apexit plus) solvents groups descriptive statistics difference mean ±s.d. mean ±s.d. mean difference t-test d.f. p-value xylene wa-w2 0.194 0.0005 0.168 0.0041 0.026 20.363 7 0.000 wb-w5 0.195 0.0011 0.145 0.0034 0.050 35.956 7 0.000 diff. 0.0261 0.0036 0.0503 0.0040 -0.024 -12.769 14 0.000 eugenate desobturator wa-w2 0.194 0.0003 0.178 0.0014 0.016 30.202 7 0.000 wb-w5 0.195 0.0009 0.150 0.0046 0.045 23.672 7 0.000 diff. 0.0165 0.0015 0.0447 0.0053 -0.028 -14.358 14 0.000 edta wa-w2 0.195 0.0009 0.193 0.0008 0.001 9.010 7 0.000 wb-w5 0.195 0.0005 0.193 0.0005 0.002 11.559 7 0.000 diff. 0.0011 0.0003 0.0020 0.0005 -0.001 -4.395 14 0.001 eucalyptol wa-w2 0.195 0.0008 0.173 0.0031 0.021 16.059 7 0.000 wb-w5 0.196 0.0013 0.168 0.0035 0.028 21.262 7 0.000 diff. 0.0214 0.0038 0.0281 0.0037 -0.007 -3.546 14 0.003 distilled water wa-w2 0.195 0.0005 0.195 0.0005 0.0001 2.376 7 0.049 wb-w5 0.195 0.0007 0.195 0.0007 0.0002 6.110 7 0.000 diff. 0.0001 0.0001 0.0002 0.0001 0.000 -3.274 14 0.006 table 3: descriptive statistics and t-test results of weight loss (g) for group c (ah plus). table 4: descriptive statistics and t-test results of weight changes (g) for group d (endosequence bc) solvents groups descriptive statistics difference mean ±s.d. mean ±s.d. mean difference t-test d.f. p-value xylene wa-w2 0.255 0.001 0.258 0.003 -0.002 -2.181 7 0.066 wb-w5 0.255 0.001 0.256 0.001 -0.001 -7.417 7 0.000 diff. -0.0025 0.0032 -0.0007 0.0003 -0.002 -1.536 14 0.147 eugenate desobturator wa-w2 0.256 0.001 0.261 0.001 -0.006 -25.731 7 0.000 wb-w5 0.256 0.001 0.264 0.001 -0.009 -34.350 7 0.000 diff. -0.0057 0.0006 -0.0089 0.0007 0.003 9.540 14 0.000 edta wa-w2 0.256 0.001 0.257 0.001 -0.001 -9.565 7 0.000 wb-w5 0.256 0.001 0.259 0.001 -0.003 -5.289 7 0.001 diff. -0.0013 0.0004 -0.0030 0.0016 0.002 2.951 14 0.011 eucalyptol wa-w2 0.255 0.001 0.256 0.001 -0.001 -6.509 7 0.000 wb-w5 0.256 0.001 0.257 0.001 -0.001 -6.347 7 0.000 diff. -0.0010 0.0004 -0.0011 0.0005 0.0002 0.639 14 0.533 distilled water wa-w2 0.255 0.001 0.257 0.001 -0.002 -11.745 7 0.000 wb-w5 0.255 0.001 0.257 0.001 -0.002 -28.987 7 0.000 diff. -0.0015 0.0004 -0.0015 0.0001 0.0000 0.090 14 0.930 wa: original weight (g) for the 2-min. group. w2: sample weight (g) after 2 min immersion time. wb: original weight (g) for the 5-min. group. w5: sample weight (g) after 5 min immersion time. solvents groups descriptive statistics difference mean ±s.d. mean ±s.d. mean difference t-test d.f. p-value xylene wa-w2 0.334 0.001 0.310 0.008 0.024 8.416 7 0.000 wb-w5 0.334 0.001 0.300 0.002 0.034 42.442 7 0.000 diff. 0.0256 0.0072 0.0339 0.0023 -0.008 -3.081 14 0.008 eugenate desobturator wa-w2 0.334 0.001 0.331 0.001 0.003 12.261 7 0.000 wb-w5 0.334 0.001 0.330 0.001 0.004 27.710 7 0.000 diff. 0.0030 0.0006 0.0044 0.0004 -0.001 -5.103 14 0.000 edta wa-w2 0.334 0.001 0.334 0.001 0.000 14.279 7 0.000 wb-w5 0.334 0.001 0.334 0.001 0.001 10.095 7 0.000 diff. 0.0005 0.0001 0.0005 0.0002 0.000 -1.203 14 0.249 eucalyptol wa-w2 0.336 0.002 0.331 0.003 0.005 9.673 7 0.000 wb-w5 0.335 0.001 0.328 0.002 0.007 16.406 7 0.000 diff. 0.0053 0.0015 0.0069 0.0012 -0.002 -2.310 14 0.037 distilled water wa-w2 0.335 0.000 0.335 0.000 wb-w5 0.335 0.001 0.335 0.001 diff. 0 0 0 0 j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 18 discussion endodontic retreatment requires the complete debridement of the remnants of filling materials; for removing these fillings and sealer out of the aberration and fins of root canal systems, literature has proposed “wicking action” to be a final step in removing the root filling, this can be provided by solvents. hence, it will be useful to use solvents with hand or rotary files for removing root canal debris(1,9). the present study conducted to comparatively evaluate the dissolving capabilities of different solvents (xylene, eugenate desobturator, eucalyptol and edta) on four root canal sealers (endofill, apexit plus, ah plus and endosequence bc sealer). xylene is chlorinated hydrocarbon commonly considered as a common solvent of organic substances, possibly because of destabilization of the covalent bonds linking the carbon atoms(10). it may also dissolve or soften the root canal sealers and could potentially facilitate their removal by mechanical means(1). in 1992 pécora et,al. presented orange oil, it is an essential oil used as a dissolving oil of zinc oxide eugenol-based cement. orange oil represents an excellent alternative solvent when compared to potentially toxic solvents(8). eucalyptol, the major component of eucalyptus oil, it is used in pharmaceuticals for fragrance, flavoring and to increase appetite (refreshing flavor). eucalyptol clinically acceptable solvent, and are not considered potentially cancerogenic or cytotoxic(7). a study in 2009 stated that edta used for removing the smear layer can also dissolve some sealers that are possible to remain in root canals. therefore, the above four mentioned solvents used in the present study. distilled water used as a control group in the study(11). endodontic sealer divided according to their chemical composition into: zinc oxide-eugenol based, calcium hydroxide based, glass ionomer based, resin-based, bioceramic based, mta-based and silicon based sealer(12). in the present study, four types of root canal sealers from different chemical groups are selected. endofill is a zinc oxide eugenol-based sealer. traditionally, zoebased sealers have been the most commonly used sealants. they act as the gold standard against which other types of sealers are compared, since they reasonably have most of grossman's requirements for root canal sealers. apexit plus is calcium hydroxide based-sealers. no studies were found for evaluating and compare the dissolution of apexit plus sealer in (xylene, eugenate desobturator, eucalyptol and edta). ah plus is epoxy resin based sealers, it is mechanically harder and more difficult in removal than zinc oxide eugenol-based sealers. a study in 2002 have stated that resin-based sealers can attach more strongly to both gutta-percha and dentin as compared to zinc oxide eugenol and calcium hydroxides based sealers(13). a study in 2007 have mentioned that resin-based sealers have more consistent and deeper penetration into dentinal tubules than other types of sealers both in vitro and in vivo(14). in paint industries, solvents can often used for softening resin coating materials on paints to permit their easy removal. these solvents that used for paints removal can be considered in endodontic retreatment to remove the strongly adhering resin-based sealer from root canal walls(1). whitworth and boursin evaluated the solubility of ah plus, apexit and tubli-seal sealers in halothane and chloroform, they concluded that ah plus sealer was significantly more soluble than other tested sealers in both halothane and chloroform(2). in the present study, the evaluation and comparison of the solubility of ah plus in xylene, eugenate desobturator, eucalyptol, edta and distilled water were performed. endosequence bc sealer (calcium phosphate silicate-based sealer) a revolutionary premixed and injectable root canal sealer utilizing new bioceramic nanotechnology. a study in (2011) evaluated the efficacy of protaper universal retreatment instruments, hand files, heat and chloroform on the removal of bc sealer when used in combination with gutta-percha as compared with ah plus sealer, it concluded that conventional retreatment methods are not able to completely remove bc sealer(15). in the present study, we evaluated the effect of xylene, eugenate desobturator, eucalyptol and edta on endosequence bc sealer, because no other studies examined if these solvents are effective in removal of this sealer during root canal retreatment. there is no international standard or tests to study the dissolution of root canal filling materials in solvents. the iso 6876:2001 standard explains the procedure to evaluate the solubility of set sealer in water. according to the instructions, ring molds with an internal diameter of 20 mm and 1.5mm in height should be used(16). similar methods have been previously described(3,1,17,18,10) using different sizes of ring molds (5 x 2; 4 x 2; 8 x 2; 6.4 x 1.6mm). in the present study, standardized metal ring 8mm in internal diameter and 2mm in height used to prepare the sealer specimens. j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 19 few clinical data are presented on the time clinicians typically leaves the root canal flooded with solvents during root canal retreatment. laboratory-based revealed that the time required for removing material is approximately 2-10 minutes. researchers in previous studies used the same immersion periods(11). in the present study, 2 and 5 min immersion times are used. in order to enhance the accuracy of the measurements, one sample used for just one immersion period, thus undesired weight loss of the specimens because of the repeated drying and immersion is excluded. each sample immersed in new solvent to ensure the purity of the solvents. after the immersion period, all sealer samples rinsed in double-distilled water in order to remove loose materials of decomposition(19). drying process during 24 hours was suitable to the methodology because in previous pilot study an increase in weight after the immersion detected in some samples(20). the weight loss in each sealer sample calculated to determine their dissolution. the criteria to evaluate the amount of the lost material were according to a study of martos et,al.(18). this method provides a simple, cost-effective and reproducible method of solubility evaluation(2). it should be kept in mind that this method allows only the comparison between different materials(16). in using this method, we could not consider several clinically relevant parameters such as temperature of solvents, canal system anatomy and dilution of solvent by biological fluids or irrigants because of in vitro conditions(11). the results from the present study showed that the endodontic sealers used in the study, except endosequence bc sealer, were soluble in the tested solvents, and there were differences among the groups. this result is in accordance with several previous studies(3, 11, 18,21, 22) who reported the ability of some solvents to dissolve root canal sealer during endodontic retreatment. the dissolving efficacy of different solvents on group a (endofill sealer): the data of the present study provide evidence that xylene is more effective for endofill cement than other solvents; since it showed more dissolution value after 2min immersion time, followed by eugenate desobturator, edta and eucalyptol in descending order, there is a highly significant difference between xylene and other tested solvents (p<0.01); while after 5 min immersion time, eugenate desobturator showed the best dissolving capability followed by xylene, no significant difference between these two solvents (p>0.05). higher values of solubility obtained at 5 min than that at 2 min immersion time (p< 0.01). d.w showed the least dissolving capability at both 2 and 5 min immersion times with a highly significant difference between d.w. and other tested solvents (p< 0.01).these results are in agreement with(23) who found that xylene and orange oil had a similar effects, and there is significant solubilization of endofill and intrafill (zinc oxide eugenol-based sealers) for 2, 5 or 10 min immersion times. the dissolving efficacy of different solvents on group b (apexit plus sealer): regarding the solubility of apexit plus in tested solvents, the data of the present study showed that there is a significant solubilization of apexit plus in all tested solution. xylene is more effective solvents for apexit plus than other tested solvents, because it exhibited the best dissolving capability at both 2 and 5 min immersion times (p<0.01). eugenate desobturator, eucalyptol and edta had a highly significant dissolving capability at both 2 and 5 min (p< 0.01) with variations among these subgroups. d.w showed the least dissolving capability, there is a high significant difference between the d.w and other tested solvents (p< 0.01). higher values of solubility obtained after 5 min than that after 2 min. the dissolving efficacy of different solvents on group c (ah plus sealer): according to the results of the present study, there is a significant weight loss in all tested solvents except the control group at both 2 and 5min immersion times. xylene is a far more effective solvent for ah plus cement than other solvents; since it exhibited the best dissolving capability at both 2 and 5min immersion time. shenoi et, al. (2014) mentioned that the setting of epoxy resin-based sealers includes polymerization and cross linking of their monomers, producing 3d lattice. this set polymer is not affected by water or saline, maybe due to the existence of hema in its composition. hydrophobic organic solvents such as xylene may have the capability to penetrate the 3d lattice leading to swelling of the lattice and reducing the strength and hardness of the material (1). eugenate desobturator, eucalyptol and edta had a highly significant dissolving capability at both 2 and 5 min (p< 0.01) with variations between these subgroups. higher values of solubility were obtained at 5 min. j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 20 the dissolving efficacy of different solvents on group d (endosequence bc sealer): the data after immersion of endosequence bc samples in the tested solvents showed that there is an increase in the weight of endosequence bc samples in all tested solvents with variations between these subgroups, possibly due to liquid sorption by its components. the mechanism related to liquid sorption and distribution in the matrix is still not totally elucidated. with most materials, there are two competitive processes that take place, one is dissolution and the other is fluid uptake(19). the results of the present study showed that the ability of endosequence bc sealer to absorb fluid is much greater than its rate of dissolution. from that it is obvious that endosequence bc sealer is insoluble in these tested solvents. references 1. shenoi pr, badole gp, khode rt. evaluation of softening ability of xylene & endosolv-r on three different epoxy resin based sealers within 1 to 2 minutes an in vitro study. restor dent endod 2014; 39(1): 17-23. 2. whitworth jm, boursin em. dissolution of root canal sealer cements in volatile solvents. int endod j 2000; 33(1): 19-24. [ivsl] 3. bodrumlu e, er o, kayaoglu g. solubility of root canal sealers with different organic solvents. oral surg oral med oral pathol oral radiol endod 2008; 106(3): 67-9. [ivsl] 4. oliveira dp de, barbizan jvb, trope m, teixeira fb. comparison between gutta-percha and resilon removal using two different techniques in endodontic retreatment. j endod 2006; 32(4): 362-4. 5. scelza mf, coil jm, maciel ac, oliveira lr, scelza p. comparative sem evaluation of three solvents used in endodontic retreatment: an ex vivo study. j appl oral sci 2008; 16(1): 24-9. 6. khatavkar r, hegde v. current concepts in guttapercha removal for retreatment part i. dental tribune 2010; 18. 7. oyama kon, siqueira el, santos nd. in vitro study of effect of solvent on root canal retreatment. braz dent j 2002; 13 (3): 208-11. 8. mushtaq m, farooq r, ibrahim m, yaqoob khan f. dissolving efficacy of different organic solvents on gutta-percha and resilon root canal obturating materials at different immersion time intervals. j conserv dent 2012; 15(2): 141-5. 9. duncan hf, chong bs. removal of root filling materials. endodontic topics 2008; 19(1): 33-57. 10. tanomaru-filho m, orlando ta, bortoluzzi ea, silva gf, tanomaru jmg. solvent capacity of different substances on gutta-percha and resilon. braz dent j 2010; 21(1): 46-9. 11. keleş a, köseoğlu m. dissolution of root canal sealers in edta and naocl solutions. j am dent assoc 2009; 140(1): 74-9. 12. tyagi s, mishra p, tyagi p. evolution of root canal sealers: an insight story. eur j gen dent, 2013; 2(3): 199-218. 13. lee kw, williams mc, camps jj, pashley dh. adhesion of endodontic sealer to dentin and guttapercha. j endod 2002; 28: 684–8. 14. mamootil k, messer hh. penetration of dentinal tubules by endodontic sealer cements in extracted teeth and in vivo. int endod j 2007; 40(11): 873–81. 15. hess d, solomon e, spears r, he j. retreatability of a bioceramic root canal sealing material. joe 2011; 37(11): 1547-9. 16. faria-júnior nb, loiola le, guerreiro-tanomaru jm, berbert fl, tanomaru-filho m. effectiveness of three solvents and two associations of solvents on gutta-percha and resilon. braz dent j 2011; 22(1): 41-4. 17. schäfer e, zandbiglari t. a comparison of the effectiveness of chloroform and eucalyptus oil in dissolving root canal sealers. oral surg oral med oral pathol oral radol endod 2002; 93(5): 611-6. 18. martos j, bassotto ap, gonzález-rodríguez mp, ferrer-luque cm. dissolving efficacy of eucalyptus and orange oil, xylol and chloroform solvents on different root canal sealers. int endod j 2011; 44(11): 1024-8. [ivsl] 19. hemed sj, khalil wm, mohammed sa. the solubility of a zinc oxide eugenol root canal sealer (endofil) in normal saline solution at different time intervals. j bagh college dentistry 2005; 17(3): 4-7. 20. rubino ga, akisue e, nunes bg, gavini g. solvency capacity of gutta-percha and resilon using chloroform, eucalyptol, orange oil or xylene. j health sci inst 2012; 30(1): 22-5. 21. erdemir a, adanır n, belli s. in vitro evaluation of the dissolving effect of solvents on root canal sealers. journal of oral sci 2003; 45(3): 123-6. 22. al-qurane nt. the effectiveness of the organic volatile solvents in retreatment of root canal system (in vitro study). medical j babylon 2013; 10(2): 497-501. 23. martos j, gastal mt, sommer l, lund rg, del pino fa, osinaga pw. dissolving efficacy of organic solvents on root canal sealers. clin oral investig 2006; 10(1): 50-4. reem.doc j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 77 evaluation of shear bond strength of zirconia to tooth structure after different zirconia surface treatment techniques reem mounes dawood, b.d.s. (1) adel f. ibraheem, b.d.s., m.sc. (2) abstract background: this study aimed to evaluate the effect of zirconia different surface treatments (primer, sandblast with 50μmal2o3, er,cr:ysgg laser) on shear bond strength between zirconia surface and resin cement. material and methods: sixty presintered y-tzp zirconia cylinder specimens (ips e.max zircad, ivoclar vivadent) will be fabricated and sintered in high temperature furnace of (1500 c for 8 hours) according to manufacturer’s instructions to the selected size and shape of (5mm. in diameter and 6mm in height). all specimens were ground flat using 600.800.1000.1200, aluminum oxide abrasive paper to obtain a standardized surface roughness. surface roughness values were then recorded in µm using surface roughness tester (profilometer) to obtain a standardized data base line for all samples. the specimens were then randomly divided into three main groups (n=20); group a: no surface treatment (control group), group b: specimens in this group treated with 50μm al2o3 and group c: specimens in this group treated with er,cr:ysgg laser. sixty sound human premolars were used in this study, after construction of acrylic blocks, the occlusal surface of the teeth were ground flat, with diamond cutting disk to obtain a flat dentine surface . prior to cementation of zirconia cylinders to tooth specimens subgroups (a1,b1,c1) will receive a coat of metal/zirconia primer and left to react for three minutes, while the subgroups (a2,b2,c2) were left undisturbed. bonding surface of zirconia cylinder was then luted with speedcem self adhesive resin cement under a static load of 2kg. placed on the vertical arm of the surveyor and allowed to auto cure for 4minutes.the final cemented specimens were then stored in distilled water at room temperature for 24hours. all specimens were subjected to shear loading force in a universal testing machine at crosshead speed of 1mm/min. the shear bond strength values were analyzed statistically with one-way anova; the fractured surfaces of zirconia cylinders were examined with a stereo-microscope to observe the failure mode. results: the air borne-particle of 50μm followed by primer application showed significantly the higher bond strength than other groups. conclusion: within the limitation of this study, the results showed that sandblasting the bonding surface of zirconium cylinders with 50μmal2o3 produced the highest values of shear bond strength , also the use of primer enhanced shear bond strength as well. keyword: zirconia surface treatments, shear bond strength. (j bagh coll dentistry 2015; 27(1):77-85). introduction in recent years, there is increasing demand for metal free restoration due to the increasing interest in aesthetic. both patients and clinicians have been seeking superior aesthetic metal free tooth colored restorations (1). all ceramic restorations provide the most aesthetic pleasing restorations; significant effort has been made over the years to improve their brittleness and low tensile strength. zirconium oxide–based materials, especially yttriatetragonal zirconia polycrystals (y-tzp), were introduced for prosthetic rehabilitations as a core material for single crowns, conventional and resin-bonded fixed partial dentures (fpds) (2) and, in dental implantology, as abutments or implants furthermore the combination of y-tzp and computer-aided design/computer-aided manufacture (cad/cam) systems reduces the number of steps in prosthetic manufacturing and eliminates the variables introduced by the manual procedures of the dental technician. (3) (1) master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. y-tzp exhibits exceptional physical and mechanical properties, such as high flexural strength, fracture toughness, hardness, wear and corrosion resistance in acidic and basic ambient conditions, translucency colour stability, greater effectiveness of diagnostic radiographs (4, 5, 6) and high biocompatibility. moreover, the polycrystalline structure, which lacks a glass matrix, makes zirconia ceramic more resistant to hydrofluoridric acid etching and, as a consequence, resistant to chemical roughening (7). reliable cementation of fixed prosthetic restorations represents one of the most sensitive and crucial tasks during the dental treatment with desirable long term clinical success. because of its particular structure, zirconia restorations require a special conditioning before cementation in order to achieve a strong bond to dentine, as the clinical success of ceramic restorations depends on the cementation process (8). for this reason, different approaches have been used to enhance the bond between the zirconia and resin cements, such as coating methods (9), a selective infiltration-etching technique (10). phosphate ester monomer, 10methacryloyloxydecyl dihydrogen phosphate j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 78 (mdp) based materials (4), surface roughening by airborne-particle abrasion, and surface roughening by the use of laser. materials and methods fabrication of zirconia samples: sixty zirconia cylinders were milled from presintered y-tzp zirconium oxide blocks (ips e.max zircad, ivocalr vivadent),with the dimensions of(19 mm,15.5mm,55mm), each zirconia blank was detached from its fitting pin ,each blank was divided into two halves with a cutting saw, each half was divided longitudinally into four equal parallel sided shaped blank by a cutting saw as well, each part was then glued into the fitting pin figure (1), the fitting pin was then placed into the designated place in the milling machine. a straight hand piece with a carbide round bur operating at high speed was fixed to the movable member of the milling machine in a way allowing back and forth free movement of it along the zirconia parallel sided blank figure (2), in this way each parallel sided blank was cut into a cylinder shaped blank of 6.25mm in diameter figure (3), each cylindrical blank was cut by a diamond cutting disk into 3 cylinders, each cylinder was measured 7.5 mm in height figure (4). figure 1: parallel sided blank glued on the fitting pin figure 2: milling and cutting the zirconium parallel sided blank figure 3: cylindrical zirconia blank figure 4: cutting cylindrical blank with diamond disk the obtained cylinders were then sintered in tube furnace (infire htc speed sintering furnace, sirona) at 1500 oc for 8 hours including cooling, according to manufacturer’s instructions. during this process a 3-dimensional volumetric j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 79 shrinkage of the milled cylinder of approximately 20% took place that is why the cylinders were milled approximately 20% larger. following sintering each zirconia cylinder was measured approximately (5mm in diameter, 6mm in height) figure (5) figure 5: final shape and size of the zirconia cylinders the bonding surfaces of zirconia cylinders were then ground flat using a grinding machine and polished consecutively with 600, 800,1000 and 1200-grit silicon carbide abrasive papers under water cooling to obtain standardized surface roughness (11), to facilitate handling the zirconia cylinder during the polishing process a custom made holder was fabricated figure (6). figure 6: custom made holder surface roughness for each sample was then confirmed by the use of the profilometer to ensure standardization. before the surface treatments, all specimens were ultrasonically cleaned in distilled water for 3 minutes to remove contaminants. then, the specimens were randomly assigned into three groups of equal size, (n = 20), according to the surface treatments were used. specimens grouping sixty zirconia cylinders were divided into 3 main groups (n=20) according to the surface treatment that had been applied: group a: 20 zirconia cylinders were left without treatment (control group) group b: 20 zirconia cylinders were treated with er,cr:ysgg laser. group c : 20 zirconia cylinders were treated with sand blast (50 µm al2o3). prior to cementation each group was subdivided into two subgroups one of them received a coat of primer while the other was without treatment treatment of the bonding surface of the zirconia cylinder: preparation of zirconia samples before surface treatment: prior to surface treatment the specimens were cleaned with 70％ ethanol by wiping their surfaces with cotton and subsequently cleaning them for five minutes in an ultrasonic bath with ethanol (12). group a (control group): no treatment was performed to this group and it is considered as the control group. prior to cementation the specimens were cleaned with 70％ ethanol by wiping their surfaces with cotton and subsequently cleaning them for five minutes in an ultrasonic bath with ethanol (12). group b (er,cr:ysgg laser treatment) an er, cr: ysgg laser system (waterlase md, biolase) was used on the bonding surface of each zirconia cylinder. a custom made holder was made especially to keep the distance between the tip of the device and the zirconia bonding surface fixed at 1 mm, er,cr: ysgg laser , λ = 2780 nm, pulsed laser-powered hydrokinetics, and the power was 2.5 w with a 6mm quartz core tip (g4, biolase technologies inc., irvine, ca, germany) positioned at 1 mm (90°) from the bonding surface of each zirconia cylinder (focused mode) (13). repetition rate was fixed on 20 hz., the air and water were adjusted to 50% of the laser unit. irradiation was done under the supervision of a laser specialist. each sample was irradiated in a circular motion for 30 sec. to promote homogeneous irradiation and cover the entire sample area figure (7). (14) then, the specimens were cleaned with 70％ ethanol by wiping their surfaces with cotton and subsequently cleaning them for five minutes in an ultrasonic bath with ethanol (12). j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 80 figure 7: er,cr:ysgg, laser irradiating zirconia bonding surface group c (sand blast treatment) zirconia cylinders were mounted in a special holder so that the blasting tip is in a straight line with the sample at a distance of 10mm between the surface of the zirconia cylinder and the blasting tip of the airborne-particle hand-piece, the surfaces of the specimens were air particle abraded for 15 s with 50 μm al2o3 particles at 2.5 bars then, the specimens were cleaned with 70％ ethanol by wiping their surfaces with cotton and subsequently cleaning them for five minutes in an ultrasonic bath with ethanol (12). figure 7: placing the blasting tip in a straight line with the zirconium surface preparation of teeth samples: teeth selection: non-carious, un restored sixty, freshly extracted, upper first human premolars, for orthodontic purposes (the patient age range from 13-20years), of comparable size and shape were selected and collected for this study, all teeth were examined under a magnifying eye lens &light from a light curing unit to check for the absence of caries, cracks, fractures, and restoration. only intact teeth free of defect were selected. the teeth were then cleaned from debris by using slurry of pumice in a rubber cup used with a low speed hand piece, then, washed with distilled water the teeth were stored in normal saline at room temperature until sample preparation. construction of acrylic blocks: a custom made square rubber mold of (1cm x 1cm x 2cm) was used for construction of acrylic blocks for this study. the root of each tooth was embedded along their long axes in mixed cold cure acrylic to about 3mm. occlusal to the cementoenamel junction. a dental surveyor was used to position the clinical crown parallel to that of the acrylic resin block. preparation of teeth a standardized occlusal surface reduction was obtained for all samples by using a surveyor; straight hand piece with a diamond cutting disc operating at high speed was adapted to the horizontal arm of the surveyor in such a way so that the long axis of the disc was kept parallel to the long axis of the tooth. the movable table of the surveyor was adapted by using a special mold to hold each sample during cutting procedure to secure each specimen in such way so that the long axis of each clinical crown was parallel to the shaft of the cutting disk. thus, the long axis of the bur will be kept parallet to the long axis of the tooth sample all the way during occlusal surface reduction. for each tooth sample the occlusal surface was reduced to the depth of the central groove with diamond disc using high speed hand piece, with copious water cooling, to expose the upper part of the peripheral dentine surface, a new cutting disc was used every (5) teeth then the dentin surface was prepared with 240, 400, and 600 grit aluminum oxide abrasive papers, respectively under running tap water for 10 seconds each to obtain a polished surface (15) the teeth were kept hydrated in distilled water as this storage solution will not alter the permeability of dentine (16). the storage solution was stored in the refrigerator (17). after that the teeth specimens were distributed evenly among the six subgroups. bonding of zirconia cylinder to tooth surface in order to have a standardized bonding procedure, an adhesive tape with a 5mm hole in diameter was fixed on the dentine surface of each prepared tooth to restrict the bonding area to a diameter of 5 mm. prior to cementation a coat of metal zirconia primer was applied to the bonding surface of the subgroups (a2,b2,c2) of zirconia cylinder (18) with a microbrush and left to react for 180 j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 81 seconds according to manufacturer‘s instructions, and dried with water and oil free air. speed cem (ivoclar vivadent) self curing resin cement was used as a luting agent in this study, it was automixed and dispensed using disposable mixing tips supplied with the cement kit and applied directly as a thin, even layer onto the zirconia cylinder bonding side. the bonding side of zirconia was then seated onto its respective area on the bonding surface of the prepared tooth with finger pressure .for standardization, a dental surveyor was used during cementation procedure ,tooth sample was secured by using a special mold to hold each tooth sample to the movable table of the surveyor, the upper part of the vertical arm of the surveyor was used to apply a static load of 2 kg. to the zirconium block during bonding procedure to the tooth, this load is used to avoid any internal cement gaps (19) and to standardize the cementation process. excess cement was then removed using cotton pellet, light polymerization was carried out for 20 sec. per surface at 1200mw/cm2 (following the manufacturer’s instructions. then each cemented specimen was kept under the load for 4 minutes according to the manufacturer’s instructions, and kept for one hour to bench set for complete curing. one hour after cementation, specimens were stored in distilled water in a dark container at room temperature for 24hours (20). shear bond strength test the specimens were attached to a universal testing machine, (tinius olsen, h50kt, uk).and subjected to a shear force using a stainless steel chiseled-shaped rod with across head at a crosshead speed of 1mm/min until failure occurred. the tested specimens were placed in the lower part (jaw) of the testing machine. while the acrylic block was held in a horizontal position in such a way that the long axis of the chisel shaped rod is placed parallel to the occlusal surface of the tooth, the chisel end of the rod was positioned at the interface between the tooth surface and the zirconia cylinder interface, so that distance between chisel and the interface was 0.1 mm to avoid a cantilever effect on the adhesive surface (21). the specimen was secured tightly in place so that to ensure that the zirconia cylinder was always at 90 degree to the vertical plane, the specimens were stressed to failure. the shear bond test values were calculated from this measurement and expressed in mpa. fig. (2-26). shear strength [mpa] = maximum force [n] / bonding area [mm2]. light microscope examination the fractured specimens were examined after debonding to determine the mode of failure. the specimens were examined under light microscope (biovision line, italy) at magnification of 40 x to evaluate the fracture pattern. failure modes were classified into: 1. adhesive failure: if more than 75% of the zirconia cylinder surface was visible. 2. cohesive failure: if more than 75% of the zirconia cylinder surface was covered with resin. all other cases were classified as mixed failures. results descriptive statistics a total of 60 measurements of shear bond strength from six groups were recorded for six different surface treatments (appendix i). the means and standard deviations of shear bond strength with minimum and maximum values for each group are shown in table (1). table 1: descriptive statistics of the shear bond strength of different zirconia surface treatment. groups descriptive statistics mean s.d. min. max. no treatment without primer a1 1.66 0.29 1.12 2.06 no treatment with primer a2 2.77 0.23 2.45 3.06 laser without primer b1 4.68 0.32 4.13 5.07 laser with primer b2 5.72 0.28 5.2 6.04 sand blast without primer c1 7.25 0.38 6.63 7.79 sand blast with primer c2 8.40 0.52 7.64 9.08 table (1) shows the lowest mean of shear bond strength was detected in group a1 (1.66±0.29), while the highest mean (8.40±0.52) was detected in group c2. figure 8: bar-chart showing the mean values of the shear bond strength of the six groups. j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 82 inferential statistics within the single group (effect of primer) to see whether there is statistically significant difference within the group (between the subgroups), student’s t-test was applied table (2). table 2: student’s t -test. tested groups comparison d.f.=18 t-test p-value a1 vs. a2 9.57 0.000(hs) b1 vs .b2 7.74 0.000(hs) c1 vs.c2 5.6 0.000(hs) *p≤0.05 significant(s), p≤0.01 highly significant (hs), p≤0.001 very highly significant (vhs) t-test showed that group a1that there is statistically high significant difference between the subgroups according to the application of primer. among the groups (effect of the surface treatment) to see whether the difference in the mean value for the subgroups (a1,b1,c1) were statistically significant or not, one way (anova) test was applied in table (3). table 3: one way-anova between and within groups (a1,b1,c1). sum of squares d.f mean square ftest pvalue between groups 156.40 2 78.20 708.0 9 0.000 (hs) within groups 2.98 27 0.11 total 159.38 29 table (3) shows that the difference in shear bond strength for the groups (a1,b1,c1)were statistically highly significant. to examine the source of the difference among the subgroups (a1, b1,c1). further analysis of these subgroups was performed using lsd test table (4). table 4: lsd test among (a1,b1,c1) subgroups groups mean difference p-value a1 b1 -3.02 0.000 (hs) c1 -5.59 0.000 (hs) b1 c1 -2.57 0.000 (hs) table (4) shows that there is highly significant difference between subgroups. and to see whether the difference in the mean value for the groups (a2,b2,c2) were statistically significant or not, one way (anova) test was applied in table (5). table 5: one way-anova between and within groups(a2,b2,c2) sum of squares d.f. mean square f-test p-value between groups 158.21 2 79.10 584.6 9 0.000 (hs) within groups 3.65 27 0.14 total 161.86 29 table (5) shows that the difference in shear bond strength for the groups (a2, b2, c2) was statistically highly significant. to examine the source of the difference among these groups (a2, b2, c2) further analysis of these subgroups was performed using lsd test, table (6). table 6: lsd test among (a2,b2,c2) subgroups groups mean difference p-value a2 b2 -2.95 0.000 (hs) c2 -5.62 0.000 (hs) b2 c2 -2.68 0.000 (hs) table (6) shows that there is highly significant difference between the subgroups mode of failures the results of failure mode after shear bond testing as observed with a stereomicroscope are summarized in table (7). table 7: modes of failures groups subgroups adhesive failure cohesive failure mixed failure no. % no. % no. % group a a1 2 20 4 40 4 40 a2 1 10 5 50 4 40 group b b1 1 10 6 60 3 30 b2 8 80 2 20 group c c1 8 80 2 20 c2 9 90 1 10 this table shows that the predominant mode of failure for the sub groups (c2, c1, b2, b1) was cohesive failure as shown in the fig (9) adhesive failure was observed in the subgroups (a1, a2, b1) as shown in fig. (10) mixed failure occurred in all subgroups in low percentage as shown in fig(11) j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 83 figure 9: adhesive failure figure 10: mixed failure figure 11: cohesive failure discussion effect of primer the results of this study showed that treatment of the bonding surface of zirconia with metal zirconia surface prior to cementation to tooth surface significantly improve bond strength and this is clearly shown when comparing subgroups (a2,b2,c2) with the subgroups (a1,b1,c1). this can be explained by the fact that phosphonate or phosphate monomers which are the main constituens in metal/zirconia primer, phosphate monomers bond to zirconia by forming covalent bonds (zr-o-p covalent bond) with its surface and have polymerizable resin terminal ends that copolymerize with the resin cements. furthermore, the surface wetting theory recognizes a key role to the wetting capacity of the primer for improved adhesion. according to this theory the viscosity of the metal/zirconia primer would assist zirconia surface wetting, thus promoting physical adhesion. that could be attributed to phosphonate or phosphate monomers that is the main element in metal/zirconia primer, phosphate monomers bond to zirconia by forming covalent bonds (zr-o-p covalent bond) with zirconia bonding surface and have polymerizable resin terminal ends that copolymerize with the resin cements. this was clearly shown in this study when there was increased bonding strength of zirconia surface to dentine surface when using speedcem self-adhesive luting resin cement containing a functional phosphate monomer with metal/zirconia primer that containes phosphate monomer as well the result of this study agrees with others (2229) whom stated that the metal primes that contain phosphate monomers, are effective for improving bond strengths between zirconia and resin cements. the effect er,cr:ysgg laser treatment the result of this study shows that using of er,cr:ysgg laser on the bonding surface of zirconia surface resulted in significantly enhanced shear bond strengths compared with the control group, probably because of the surface roughness and irregularities on the zirconia bonding surface that enhance the interlocking with the resin cements. this result is in agreement with cavalcanti et al. (30), whom concluded that laser irradiation on zirconia bonding surface significantly increase shear bond strength due to surface roughness. however the result disagrees with ersu et al., (31) and aboushelib et al.(32). whom concluded that lasers are not effective to improve the bond strength between zro2 and resin cement, this can resin composite zirconia bonding surface resin composite zirconia bonding surface zirconia bonding surface resin composite j bagh college dentistry vol. 27(1), march 2015 evaluation of shear restorative dentistry 84 be explained by the fact that the authors in their study used different laser parameters. however the result of this study showed lower bond strength values accompanied with sandblast treatment. effect of sandblast treatment treating the bonding surface of zirconia with 50 µmal2o3 resulted in high values of shear bond strength when comparing it to laser treatment, that may be attributed to the fact that treating zirconia bonding surface with sandblast increases surface roughness and undercuts. the result of this study agrees with cavalcanti et al. 2009(30) who showed an increase in bond strength after air-abrasion with 50 µmal2o3 and disagrees with de oyague et al. (33) who concluded that air-abrasion on the bonding surface of zirconia substrate did not produce higher bond strength, even though the substrate surface became rougher than the control group, probably because of different grain size, or different pressure used in the study. furthermore, the result of this study shows that treating zirconia bonding surface with 50 µm al2o3 produced significant enhancement in bonding strength when comparing it with other treatment subgroups. effect of primer with other surface treatments the result of this study has showed that using sandblast with primer give us the highest mean of shear bond strength when comparing it with other subgroups, this could be explained by the fact that using multifunctional methods ,which mix the ability to create a rough surface for micromechanical interlocking and increase the surface area to establish chemical bond with reactive substances .this was clearly shown in this study when metal/zirconia primer was applied to the zirconia bonding surface of the subgroups (a2,b2,c2) after air abrasion and er,cr:ysgg laser treatment, and high significant difference was noticed among these subgroups, when comparing them with subgroups (a1,b1,c1). the result is an agreement with yang et al. (34), whom stated that the combination of primers and air-abrasion methods tend to produce better bond strength, especially in long term durations. mode of failure studying the results of examining of bonding surface of zirconia, by using stereomicroscope at 40x magnification, table (7) highly support the result of this study. studying table (7) shows that mode of failures when using sandblasting treatment was mostly cohesive failure and this indicates that sandblasting the boding surface of zirconia creates high bonding to resin cement. references 1. cavalcanti an, foxton rm, watson tf, oliveira mt, giannini m and marchi gm. bond strength of resin cements to a zirconia ceramic with different surface treatments. operative dentistry 2009; 34(3): 280–287. 2. kansu g, aydin ak. evaluation of the biocompatibility of various dental alloys: part i toxic potentials. eur j prosthodont restor dent 1996; 4: 129–36. 3. blatz mb. long-term clinical success of all-ceramic posterior restorations. quintessence int 2002; 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25(2): 172–9. 34. yang b, barloi a, kern m. influence of air-abrasion on zirconia ceramic bonding using an adhesive composite resin. dent mater j 2010; 26(1):44–50. j bagh college dentistry vol. 32(2), june 2020 effect of different 1 effect of different bracket types on streptococcus mutans count in orthodontic patients using fluoridated toothpaste (3)maha a. mahmood (2) dabagh-dhiaa j. n. al (1) hala m. jasim https://doi.org/10.26477/jbcd.v32i2.2886 article doi: abstract background: plaque retention during fixed orthodontic therapy is an important cause of developing enamel demineralization. the purpose of this study was to evaluate the effect of different brackets types on the count of streptococcus mutans in orthodontic patients using conventional fluoridated toothpaste. materials and methods: plaque samples were collected from maxillary 1st premolar teeth of twenty right handed patients (using split mouth technique) before bonding, after 48 hrs of bonding using tooth brush only, and after 2 weeks of using fluoridated toothpaste. stainless steel bracket was bonded on right first premolar while the left one was bonded with sapphire bracket. the calculation of the streptococcus mutans count was done using the plate counting method utilizing colony counter. the differences between the two types of brackets were determined using the wilcoxon signed ranks test. results: the median bacterial count on the right side was insignificantly higher than the left side; streptococcus mutans in the plaque sample around the sapphire brackets showed insignificantly less counts than around the stainless steel one, when the patients used tooth brush only or fluoridated toothpastes. fluoridated toothpastes reduced streptococcus mutans insignificantly around both types of brackets. conclusion: fluoridated toothpaste acts effectively in reducing streptococcus mutans colony counts around sapphire and stainless steel brackets. keywords: streptococcus mutans, stainless steel brackets, sapphire brackets. (received: 10/10/2019; accepted: 6/11/2019) introduction white spot lesion formation following enamel demineralization is the most popular complication associated with fixed orthodontic appliance therapy. (1) it resulted from increased numbers of cariogenic microorganisms in dental biofilm, compromised oral hygiene and decreased ph. (2) although white spot lesion occurs irrespective of orthodontic therapy, patients undergoing orthodontic treatment have oral ecological alterations in which the numbers of cariogenic bacteria, especially mutans streptococci are significantly increased and returned to the ordinary level after the removal of the orthodontic appliance. (3) streptococcus mutans is a potent initiator of enamel demineralization because there are many virulence factors unique to it and play important role in caries initiation. (4) first, s. mutans is an anaerobic microorganism which produces lactic acid during its metabolism. second, it has the ability to bind tooth surfaces in the existence of sucrose via the formation of glucans which are a polysaccharide that helps binding the microorganism to the tooth surface. (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. (3) professor, department of basic sciences, college of dentistry, university of baghdad. corresponding author, adelmaha70@yahoo.com the most important virulence factor of s. mutans is the acidophilicity. in contrast to the majority of oral bacteria, s. mutans thrives under acidic environment and becomes the dominant microorganism in cultures with reduced ph. (5) although brushing teeth twice daily is considered effective in bacterial count reduction, the high prevalence of gingival inflammation in orthodontic patients often suggests improper oral hygiene procedures in most patients. (6) there is an important difference in biofilm formation and adhesion of bacteria among orthodontic brackets made from various materials. (7,8) the primary affinity of bacteria to surfaces is mostly due to hydrophobic and electrostatic interactions. surfaces with high surface free energy (sfe) attract bacteria such as s. mutans more easily. (9) a study conducted by lópez et al. (10) showed a statistically non-significant difference in the s. mutans adhesion to stainless steel, plastic or ceramic brackets. chemical plaque control procedures are used sometimes for more effective plaque removal (8). dean et al. (11) reported that fluoride concentration in biofilms increased significantly after brushing with toothpaste containing fluoride and the primary cariostatic effect of fluoridated toothpastes is the remaining fluoride in the dental biofilm that was not eliminated by tooth brushing. the objectives of the present study were to determine the levels of s. mutans on sapphire and stainless steel orthodontic brackets in patients undergoing fixed orthodontic therapy brushing their teeth with fluoridated toothpaste. https://doi.org/10.26477/jbcd.v32i2.2886 j bagh college dentistry vol. 32(2), june 2020 effect of different 2 materials and methods twenty patients accepted to participate in this study. after signing a written consent form, a baseline record of bacterial count was taken from the right and left maxillary 1st premolars, then bonding of the maxillary teeth was performed with stainless steel brackets (pinnacle, orthotechnology, usa) except the left maxillary 1st premolar that was bonded with sapphire bracket (pure, orthotechnology, usa) using resilience bracket adhesive (orthotechnology, usa) and light cure unit (woodpecker, china) as shown in figure 1. the patients were instructed to brush their teeth with toothbrush only and come in a recall visit after 48 hr. to take another sample from the same teeth. after that, the patients were instructed to brush their teeth with fluoridated toothpaste (sensodyne toothpaste, glaxosmithkline, usa) twice daily and come again for a recall visit after 2 weeks to take further sample. the samples taken were pooled plaque collected from the buccal surface of both teeth using a sterilized dental probe (after drying) utilizing the four-pass sampling technique in which a standardized, sterilized instrument's tip is moved circumferentially around the bracket. data were analyzed using spss program version 25. the descriptive statistics included medians, means, standard deviations, minimum and maximum values, while the inferential statistics included wilcoxon signed ranks test to detect the side difference and friedman test to study the effect of time on bacterial count. probability value was set at 0.05. figure 1: a; stainless steel bracket bonded on tooth number 14, b; sapphire bracket bonded on tooth number 24. results table 1 shows the descriptive statistics and side difference of the bacterial count in three periods. statistically, the bacterial count in the right side was insignificantly higher than the left one in all periods (p>0.05). friedman test was used to test the effect of time on s. mutans count. in both sides, bacterial count was decreased insignificantly after using fluoridated toothpastes (table 1 and 2). table 1: descriptive statistics and side difference of bacterial count before bonding, after 48 hrs of using tooth brush only, and after 2 weeks of using conventional fluoridated toothpastes. duration side descriptive statistics side difference median × 103 mean × 103 s.d. × 103 min. × 103 max. × 103 wilcoxon signed ranks test p-value before bonding right 135 279.5 331.2 3 20 840 -0.663 0.508 (ns) left 107.5 175.5 173.6 4 15 575 after 48 hrs (brushing only without toothpaste) right (ss) 227.5 314.3 319.5 0 8 900 -0.178 0.859 (ns) left (sapph.) 132.5 258.5 305.3 9 5 950 after 2 weeks (brushing with fluoridated toothpastes) right (ss) 75 159.5 178.0 2 4 500 -0.357 0.721 (ns) left (sapph.) 25 251.3 5 514.4 9 3 1600 ss: stainless steel, sapph: sapphire bracket, ns: non-significant a b j bagh college dentistry vol. 32(2), june 2020 effect of different 3 table 2: effect of time on the bacterial count for both sides. side right side left side friedman test 3.2 2.6 d.f. 2 2 p-value 0.202 (ns) 0.273 (ns) discussion the market contains various bracket types made of different biomaterials. the adherence of plaque to the fixed appliance is highly contributed by the type of bracket material as it plays a role in the amount of plaque accumulation and bacterial adhesion as well as in the risk of white spot lesion development. (8) brackets surface characteristics are shown to affect bacterial adhesion especially surface free energy (also called wettability) and surface roughness. variations in surface characteristics can explain the differences in the adhesion of streptococcus mutans to different biomaterials. (9) in the present study, the median bacterial count in the right side was higher than the left side although non-significant but the difference is clear. this can be attributed to the use of right side hand in brushing that cleans the teeth of the left side better than the right one. (13) after 48hr of bonding and brushing with tooth brush only, bacterial count is increased on both sides with a non-significant difference being higher in right side also. this could be due to the fact that the monocrystalline sapphire bracket (on left side) has a surface roughness less than that of the stainless steel bracket (on the right side). (7,14,15) moreover; eliades et al. (16) found that stainless steel offered the highest critical surface tension and total work of adhesion, demonstrating an amplified potential for microorganism attachment on metallic brackets. in contrast, fournier et al. (17) investigated the affinity of s. mutans to different bracket types and found that s. mutans demonstrated weaker adherence to the metal brackets than to plastic or ceramic brackets. after 2 weeks of using fluoridated toothpastes, the bacterial count decreased markedly with a nonsignificant side difference. this could be due to anti-caries effect of the fluoride containing toothpaste which results from the formation of calcium fluoride (caf2) in dental plaque and on the enamel surface. (18,19) the effect of time on streptococci mutans adhesion was examined using friedman test. by comparing the medians of both sides before bonding and after 48hr, the adhesion of streptococcus mutans increased with increasing time but there was no statistically significant difference. this elevation in count could be due to the fact that orthodontic brackets are covered instantly by the salivary pellicle in the oral cavity; therefore, the adhesion of oral microorganisms to the bracket surfaces is governed to a large extent by the properties of the adsorbed salivary protein layer. the salivary pellicle as a binding receptor can promote the adhesion of s. mutans. (7,20) conclusion fluoridated toothpaste is clinically efficient in reducing s. mutans colony counts around sapphire and stainless steel orthodontic brackets. conflict of interest: none. references 1. chambers c, stewart s, su b, sandy j, ireland a. prevention and treatment of demineralization during fixed appliance therapy: a review of current methods and future applications. br dent j. 2013; 215: 505-11. 2. korbmacher hm, huck l, kahl-nieke b. fluoridereleasing adhesive and antimicrobial self-etching primer effects on shear bond strength of orthodontic brackets. angle orthod. 2006; 76: 845-50. 3. fournier a, payant l, bouclin r. adherence of streptococcus mutans to orthodontic brackets. am j orthod dentofacial orthop.1998;7: 114414. 4. samaranayake lp, jones bm, swlly c. essential microbiology for dentistry. 2nd ed. edinburgh: churchill livingstone; 2002. 5. bagg j, macfarlane tw, poxton ir, smith a. essential of microbiology for dental students. delhi: oxford university press; 2006. 6. jurela a, repic d, pejda s, juric h, vidakovic r, matic i. the effect of two different bracket types on the salivary levels of s. mutans and s. sobrinus in the early phase of orthodontic treatment. angle orthod. 2013; 83: 140-5. 7. ahn sj, kho hs, lee sw, nahm ds. roles of salivary proteins in the adherence of oral streptococci to various orthodontic brackets. j dent res. 2002; 81: 411–5. 8. papaioannou w, gizani s, nassika m, kontou e, nakou m. adhesion of streptococcus mutans to different types of brackets. angle orthod. 2007; 77: 1090-5. 9. lee sp, lee sj, lim bs, ahn sj. surface characteristics of orthodontic materials and their effects on adhesion of mutans streptococci. angle orthod. 2009; 79: 353-60. 10. lópez jdt, sánchez meraz w, mariel cárdenas j, gonzález amaro am, gutiérrez cantú fj, mariel murga h. bacterial load assessment in metallic versus esthetic brackets. revista mexicana de ortodoncia. 2015; 3: 228-32. j bagh college dentistry vol. 32(2), june 2020 effect of different 4 11. dean ja, avery dr, mcdonald re. dentistry for the child and adolescent. 9th ed. c.v. missouri: mosbyelsevier; 2011. 12. george j, hegde s, rajesh ks, kumar a. the efficacy of a herbal-based toothpaste in the control of plaque and gingivitis: a clinico-biochemical study. indian j dent res. 2009; 20: 480-90. 13. kadkhodazadeh h, khodadustan a, amid r, darabi a. plaque removal ability in left and right handed patients in different parts of the oral cavity. j periodontol implant dent. 2012; 4: 24-28. 14. anhoury p, nathanson d, hughes cv, socransky s, feres m, chou ll. microbial profile on metallic and ceramic bracket materials. angle orthod. 2002; 72: 338-43. 15. kassis a, sarkis d, adaimé a. quantitative evaluation of adhesion of streptococcus mutans to three orthodontic adhesives: an in vitro study. iajd 2011; 2: 13-8. 16. eliades t, eliades g, brantley w. microbial attachment on orthodontic appliances: wettability and early pellicle formation on bracket materials. am j orthod dentofacial orthop. 1995; 108: 351–60. 17. fournier a, payant l, bouclin r. adherence of streptococcus mutans to orthodontic brackets. am j orthod dentofacial orthop. 1998; 114: 414–7. 18. ghazi sm. comparative study of in vitro antibacterial activity of miswak extracts and different toothpastes. am j agricultural biol sci. 2013; 8: 82-8. 19. sharma a, kumar rr, mathew s. the effect of miswak and fluoride toothpastes on dental plaquea comparative clinical and microbiological study. j dent med sci. 2017; 16: 74-7. 20. ahn s, lim b, lee s. surface characteristics of orthodontic adhesives and effects on streptococcal adhesion. am j orthod dentofacial orthop. 2010; 137: 489-95. الخالصة : ان تجمع الطبقة الجرثومية خالل ارتداء جهاز التقويم الثابت يعد سبب مهم في فقدان معادن االسنان. الغرض من هذه الدراسة الخلفية هي فحص تاثير االنواع المختلفة من حاصرات التقويم على اعداد البكتريا المسببة للتسوس في مرضى تقويم االسنان الثابت الذين سنان حاوي على الفلورايد.يستعملون معجون ا : تم جمع عينات الطبقة الجرثومية من االسنان الطاحنة لمرضى يرتدون التقويم , الحاصرات المعدنية تم تثبيتها على المواد و الطرق ساعه 48عد و تم جمع العينات قبل تثبيت التقويم وب 24الحاصرات المصنوعه من السيراميك تم تثبيتها على الطاحن رقم 14الطاحن رقم وبعد اسبوعين وخالل االسبوعين استعمل المرضى معجون اسنان حاوي على الفلورايد. تم تقييم االختالف بين المثبتات باستخدام اختبار ولكسون. موجودة في : اظهرت النتائج ان تعداد البكتريا في الجهة اليمنى اكثر من الجهة اليسرى وبدون فوارق معنوية. كانت البكتريا الالنتائج الصفيحة الجرثومية حول الحاصرات المصنوعه من السيراميك اقل من تلك حول الحاصرات المعدنية. قللت معاجين االسنان الحاوية على الفلورايد من اعداد البكتريا حول الحاصرات المعدنية و الحاصرات المصنوعة من السيراميك. الفلورايد فعاله في تقليل اعداد البكتريا حول الحاصرات المعدنية و الحاصرات المصنوعة ان معاجين االسنان الحاوية على االستنتاجات: من السيراميك. j bagh college dentistry vol. 29(4), december 2017 dentition status among pedodontics, orthodontics and preventive dentistry 89 dentition status in relation to nutritional condition among a group of intermediate school students in al-najaf city / iraq noor m. hadi laith, b.d.s., m.sc. (1) nadia a. al-rawi, b.d.s., m.sc., ph.d. (2) abstract background: nutrition can affect the development and integrity of the oral cavity as well as the progression of oral diseases such as dental caries which was the most predominant and wide spread not life threatening human diseases especially in developing countries as in iraq. this study was conducted to assess the occurrence, prevalence and severity of dental caries condition and their relations to nutritional status among intermediate schools females in al-najaf city in iraq. materials and methods: this study was conducted among intermediate schools females aged 13, 14 and15 years old and the total sample consisted of 754 students. the assessment of nutritional status was performed using body mass index (bmi) following centers for disease control and prevention growth chart (2000). diagnosis and recording of dental caries was according to the criteria of who 1987. results: the percentage of well-nutrition was (96.2%) while the prevalence of malnutrition was (3.8%). result showed that only 5.17% of the total sample was caries-free. the mean dmft for deciduous teeth was equal to (1.77±0.15) and dmfs (3.92±0.39), while concerning permanent teeth the mean dmft was equal to (4.68±0.10) and dmfs (6.22±0.16), significant differences were seen between dmft, dmfs and age while opposite was found with nutritional status, and no significant differences were seen between caries experience of primary teeth and age and this similar was found with nutritional status conclusion: this study revealed that a higher prevalence of dental caries among well-nourished females students aged 13-15 years. therefore, there is need for an improving public and school preventive programs, and encouraged to orient health knowledge in a positive direction. key words: dental caries, nutrition. (j bagh coll dentistry 2017; 29(4): 89-95) introduction adolescents are tomorrow’s adult population, adolescence may represent a window of opportunity in which to prepare nutritionally for a healthy adult life (1). this crucial period of transition is identified by a range of age of 10-19 years by the world health organization. early adolescence after the first year of life is the critical period of rapid physical growth and changes in body composition, physiology and endocrine (2). adolescent girls health covers nutritional status, morbidity, and reproductive health. during the period of adolescence the nutrient needs are the greatest (3). nutrition is considered as one of the most important factors influencing the quality of human life worldwide, also nutritional deficiency is directly related to the retardation of growth and development, decrease resistance to infection and environmental hazards (4). adequate nutrition and healthy eating and physical exercise habits at this age are foundations for good health in adulthood (5). nutrition is an integral component of oral health. there is a continuous synergy between nutrition and the integrity of the oral cavity in health and disease (6). (1) master student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. diet and nutrition affects the integrity and developing of the oral cavity in addition to the evolution of oral diseases (7). the world health organization defines malnutrition as a number of condition with specific etiology derived from the cellular imbalance between supply of one or more nutrients, energy and the body's demand for them to ensure growth, maintenance, reproduction and specific functions (8,9). dental caries is a demineralization of the inorganic part of the tooth with the dissolution of the organic substance depending on interaction of several factors: oral micro flora (acidogenic bacteria) diet (fermentable carbohydrate), time and host (10,11). iraqi studies showed a high prevalence and severity of dental caries (12,13,14). according to age, in this study caries experience was discovered to be increase with age, with highly significant difference, this finding is in agreement with previous iraqi studies among different age groups (12,15) this may be related to accumulative and irreversible nature of dental caries (16). there was no significant differences between dmft, dmfs and its components with nutritional status this finding was similar to studies (17,18). j bagh college dentistry vol. 29(4), december 2017 dentition status among pedodontics, orthodontics and preventive dentistry 90 materials and methods this survey was conducted among urban intermediate school females students aged 13-15 years old in al-najaf city governorate in iraq. the study was conducted during the period between the beginnings of january 2016 till the end of march 2016. according to the general directorate of education reports (2015), there was (12347) females students aged 13-15 years old distributed among (25) intermediate schools in al-najaf city, they are consisted of (4569), (3890) and (3888) for age 13, 14 and 15 years old respectively. the sample representative 16 an intermediate females school were distributed in al-najaf city which were randomly selected from 25 intermediate females school in different areas of the city, adolescents who are healthy and without any systemic disease were examined. the age was taken according to the criteria of world health organization (19) and according to the last birth day, and the cross sectional random sample was calculated for prevalence studies by the formula as n=zp2(1-p)/d2 (20). body mass index (bmi): this index is a number calculated from the child’s weight and height, according to this formula (21): body weight / (height)2=bmi kg/m2 according to specific chart (22).the values of nutritional indicators were compared with international reference values using cdc growth charts (center for disease and control and prevention, 2000). diagnosis and recording of dental caries was assessed according to the criteria described by who (23). for primary and permanent dentition, if primary and permanent teeth occupied the same tooth space, the status of permanent tooth only was considered (19). data description, analysis and presentation were performed using computer software program (spss version 18). results in the present study, the total sample consisted of (754) female students, they were 223, 267 and 264 students for 13, 14 and 15 years age group respectively. table (1) illustrates the distribution of the total sample by age groups. the table shows 14 years age group exhibited the high number among the total sample followed by 15 years age group, while 13 years age group the lowest. table (2) illustrates the distribution of students according to nutritional status by age groups. this study revealed that for the total sample the percentage of total of well-nourished girls was higher than malnourished students among three age groups. regarding malnourished the table shows that 13 year age students exhibited the low percentage compared with other two age groups. table (3) shows the distribution of caries free among students in regarding to the age groups. high percentage of caries free was recorded among 14 years age group, followed by age 15 years till reach the lowest at the age 13 years. table (4) shows the distribution of caries free among students in regarding to the nutritional status. regarding malnourished students very low percentage was recorded of caries free compared with the well-nourished students. table (5) demonstrates the mean values and standard errors of caries experience by fractions in primary dentition, concerning three age groups students. caries experience was found to be higher in the 13 years age students followed by students with 14 years age while the lowest among the 15 years age group. differences was statistically no significant excited between age groups (p>0.05). decayed surface was found to be the largest fraction of dmfs value compared to ms and fs among all age groups. table (6) illustrates the mean values and standard errors of caries experience by fractions in primary dentition among students in regarding to nutritional status. caries experience was found to be higher in the well-nourished students than malnourished group. statistically no significant differences were recorded among both groups (p>0.05). decayed surface was found to be the largest fraction of dmfs value compared to the ms and fs among both groups. table (7) demonstrates the mean values and standard errors of caries experience by fractions in permanent dentition, concerning three age groups students. caries experience was found to be higher in the 15 years age students followed by students with 14 years age while the lowest among the 13 years age group. differences was statistically highly significant excited between age groups (p= 0.000). decayed surface was found to be the largest fraction of dmfs value compared to ms and fs among all age groups. table (8) illustrates the mean values and standard errors of caries experience by fractions in permanent dentition among students in regarding to nutritional status. caries experience was found to be higher in malnourished than well-nourished groups students. statistically no significant differences were recorded among both groups (p>0.05). decayed surface was found to be the largest fraction of dmfs value compared to the ms and fs among both groups. j bagh college dentistry vol. 29(4), december 2017 dentition status among pedodontics, orthodontics and preventive dentistry 91 table 1: distribution of the total sample by age. age (year) no. percentage 13 223 29.6 14 267 35.4 15 264 35.0 total 754 100 table 2: distribution of the students according to the nutritional status by age groups. age (year) descriptive nutritional status total malnourished well-nourished 13 n 6 217 223.0 % within age 2.7 97.3 100.0 % within nutritional status 20.7 30.0 29.6 % of total 0.8 28.8 29.6 14 n 13 254 267.0 % within age 4.9 95.1 100.0 % within nutritional status 44.8 35.0 35.4 % of total 1.7 33.7 35.4 15 n 10 254 264.0 % within age 3.8 96.2 100.0 % within nutritional status 34.5 35.0 35.0 % of total 1.3 33.7 35.0 total n 29 725 754.0 % within age 3.8 96.2 100.0 % within nutritional status 100.0 100.0 100.0 table 3: distribution of caries free among students by age groups. age year no. caries free no. % 13 223 12 1.59 14 267 14 1.86 15 264 13 1.72 total 754 39 5.17 table 4: distribution of caries free among students by nutritional status. nutritional status no. caries free no. % malnourished 29 1 0.13 well-nourished 725 38 5.04 total 754 39 5.17 j bagh college dentistry vol. 29(4), december 2017 dentition status among pedodontics, orthodontics and preventive dentistry 92 table 5: caries experience of the primary teeth (mean and standard errors) among students by age. age (years) variables mean se f df p-value 13 ds 4.10 0.51 1.785 2 0.176 14 2.79 0.43 15 2.00 0.91 total 3.63 0.37 13 ms 0.10 0.10 0.234 2 0.792 14 0.00 0.00 15 0.00 0.00 total 0.07 0.07 13 fs 0.27 0.21 0.440 2 0.646 14 0.00 0.00 15 0.50 0.50 total 0.21 0.15 13 dmfs 4.48 0.54 2.217 2 0.117 14 2.79 0.43 15 2.50 0.65 total 3.92 0.39 13 dmft 2.02 0.21 3.011 2 0.056 14 1.26 0.13 15 1.25 0.25 total 1.77 0.15 table 6: caries experience of the primary teeth (mean and standard errors) among students by nutritional status. table 7: caries experience of the permanent teeth (mean and standard error) among students by age groups. age (years) variables mean se f df p-value tukey-kramer post hoc 13 ds 4.81 0.23 7.900 2 0.000 13x14=0.0187 14 5.78 0.25 13x15=0.0003 15 6.22 0.26 14x15=0.4156 total 5.65 0.15 13 ms 0.31 0.09 0.171 2 0.843 -------------------14 0.26 0.07 15 0.32 0.08 total 0.30 0.05 13 fs 0.20 0.06 2.353 2 0.096 --------------------14 0.23 0.05 15 0.37 0.07 total 0.27 0.03 13 dmfs 5.33 0.27 7.879 2 0.000 13x14=0.0187 14 6.27 0.26 13x15=0.0003 15 6.91 0.29 14x15=0.4156 total 6.22 0.16 13 dmft 4.00 0.17 12.422 2 0.000 13x14=0.0096 14 4.72 0.17 13x15<0.0001 15 5.22 0.18 14x15=0.0810 total 4.68 0.10 variables nutrition t -t e st d f p v a lu e well-nourished malnourished mean se mean se ds 3.65 0.39 3.33 1.45 0.167 69 0.868 ms 0.07 0.07 0.00 0.00 0.209 0.835 fs 0.22 0.15 0.00 0.00 0.302 0.763 dmfs 3.94 0.41 3.33 1.45 0.308 0.759 dmft 1.78 0.15 1.67 0.67 0.151 0.880 j bagh college dentistry vol. 29(4), december 2017 dentition status among pedodontics, orthodontics and preventive dentistry 93 table 8: caries experience of the permanent teeth (mean and standard error) among students by nutritional status. disscussion this oral health survey was designed to evaluate the nutritional status and its relation to dentition status among urban intermediate school females students aged 13-15 years-old in al-najaf city in iraq. it was achieved because there was no previous epidemiological iraqi study concerning intermediate school female students in al-najaf city. the comparison of data with other studies, however, may not be completely valid due to variation in methods of examination used by different researchers and variation in the environment of other countries while comparison with other iraqi epidemiological studies (13,15) may give more accurate results because the majority of studies follow criteria of who in the diagnosis and dental health recording and living opportunity in the same environment. nutritional status of this study malnourished of the studied sample which was very low in comparison with other studies (14,17), and higher than reported by others (18,24). the largest numbers of the students have normal weight and the percentage of well-nourished was higher than malnourished and this may be due to improvement in the nutritional status in iraq (24). in the present study, the prevalence of caries free adolescents in al-najaf city, this was lower than that reported by others (17,25) . systemic fluoridation can reduce the prevalence and severity of dental caries in both primary and permanent dentition (26,27,28). al-azawi mentioned that the concentration of fluoride in the communal water supply in different governorates of iraq ranged from 0.12-0.22 ppm (12). this level of fluoridation is less than the optimal level recommended for maximum reduction of dental caries (0.7-1.2 ppm) (26).that may be the reason for high prevalence of dental caries illustrated in this study and other previous iraqi studies. the mean dmft in this study for the total sample of al-najaf city, compared to other iraqi studies, the dmft was higher than that reported by other studies (14,,29),while less than that reported by others (25,30). the mean dmfs in this study for the total sample of al-najaf city was higher than that reported by others (12,13). while less than that other studies (25,30). in general variation in cariesexperience between the present study and other iraqi studies may be related to variation in dietary habits, oral hygiene measures in addition to dental health services between governorates, geographical location and racial factors as regarded to be an effective factor on the prevalence and severity of dental caries to a degree that it includes cultural, social and economic differences in addition to genetic variation (26). differences in operational definition of dental caries affected by type of survey instrument used in addition to availability of radiology services have an obvious effect on rates of caries experience reported in different studies. the decayed fraction “ds” was the major component of dmfs index. this may reveal the poor utilization of dental health services for permanent dentition. the mean “ms” was greater than “fs”. this may indicate that even when dental services are available they were directed towards extraction rather than preserving permanent teeth, which may reflect a poor knowledge and attitude on the part of patients and their parents and miss concepts deeply rooted in their behavior and loss governorates oral health services on the part of regional health affairs. this result was in agreement with many studies (14 ,25). according to age, in this study caries experience for permanent teeth was recoded to be increase with age, it was higher among 15 years followed by 14 years then 13 years students with highly significant difference, this finding is in agreement with previous iraqi studies in different age groups (12;15). this may be related to accumulative and irreversible nature of dental caries (16). there were no significant differences between dmft, dmfs and its components with nutritional status since ds component was higher than fs and ms mean value. this finding was similar to that reported with other studies (17,18). in the present study the magnitude of caries experience in the very few remaining deciduous variables nutrition t -t e st d f p v a lu e well-nourished malnourished mean se mean se ds 5.65 0.15 5.69 0.73 -0.058 752 0.953 ms 0.28 0.05 0.69 0.41 -1.699 0.090 fs 0.27 0.04 0.21 0.15 0.369 0.712 dmfs 6.20 0.16 6.59 0.97 0.458 0.647 dmft 4.69 0.10 4.45 0.43 0.461 0.645 j bagh college dentistry vol. 29(4), december 2017 dentition status among pedodontics, orthodontics and preventive dentistry 94 teeth was assessed by dmft and dmfs. the mean dmft of this study was higher than that reported by other studies (18,30),and lower than that reported by al-khaza'ali (31). differences in nutritional and environmental conditions between the two populations as well as method of examination among these studies may explain these small differences in dmft. in the current study dmfs was less than that reported by other studies (14,32), but higher than that reported by others (18). the figures reported in these studies do not signify a higher caries experience, since the age of study sample was older (i.e. less deciduous teeth were available for examination). the differences concerning life type, dietary habits and dental services could be the cause of these variations in the results obtained. the components of dmfs: namely ds, ms and fs were evaluated in the current study. the mean of “ds” fraction for the total sample was found to be the highest followed by that of “fs” and “ms”. reason can be given is the accumulative nature of dental caries in deciduous teeth as it earlier than permanent teeth concerning time of eruption, so the exposure to dental caries will be higher in primary dentition, so that give attention to treatment need more than permanent teeth. in the present study dmft, dmfs, ds, ms and fs mean values were higher among well-nourished than malnourished. the differences observed between mal and well-nourished individuals failed to reach the level of statistical significance. opposite findings were obtained by other studies (14,17). references 1. kaur tj, kochar gk, agarwal t. impact of nutrition education on nutrient adequacy of adolescent girls. stud home comm sci. 2007;1:51–5. 2. khan mr, ahmed f. physical status, nutrient intake and dietary pattern of adolescent female factory workers in urban bangladesh. asia pac j nutr. 2005;14(1): 19-26. 3. who. nutrition in adolescence: issues and challenges for the health sector: issues in adolescent health and development, 2005. 4. who. several general programs of work covering the period 1984-1989. health for all. geneva. 1982. 5. kalhan m, vashisht b, kumar v, sharma s. nutritional status of adolescent girls of rural haryana. internet j epidemiol, 2010; 8(1). 6. moynihan pj. the role of diet and nutrition in the etiology and prevention of oral disease. bull world health organ 2005; 83(9):694-699. 7. shah k, hunter ml, fairchild rm, morgan mz. a comparison of the nutritional knowledge of dental, dietetic and nutrition students. br dent j 2011; 210(1):3338. 8. world health organization. nutritional research, back ground document technical discussions. geneva, 1990. 9. daleo l, bear g. dose fetal malnourished put infants at risk of caregiver neglect because their faces are unappealing. jasnh 2002; 1(2):32-35. 10. khan i. encyclopedia of common natural ingredients: used in food, drugs and cosmetics. 3rd ed. oxford, john wiley and sons, 2010. 11. garg n, garg a. text book of preventive dentistry. 2nded. new delhi;jp medical ltd,2013. 12. al-azawi l. oral health status and treatment needs among iraqi five-years old kindergarten children and fifteen-years old students (a national survey) ph.d. thesis submitted to college of dentistry, university of baghdad, 2000. 13. al-obaidi e. oral health status and treatment needs among 15 yearold students in al-diwania governorate-iraq. master thesis submitted to college of dentistry, university of baghdad. 2008. 14. al-ghalebi s. oral health status and treatment need in relation to nutritional status among 9-10 year-old school children in nassirya city/iraq. master thesis submitted to college of dentistry, university of baghdad, 2011. 15. ahmed zs. oral health status and treatment needs among institutionalized children and adolescents in comparison to school children and adolescents in iraq. master thesis submitted to college of dentistry, university of baghdad, 2002. 16. rao a. principle and practice of pedodontics. 2nd ed. new delhi, 2008. 17. hassan z. the effect of nutritional status on dental health, salivary physiochemical characteristics and odontometric measurement among five years old kindergarten children and fifteen years old students. ph.d. thesis submitted to college of dentistry, university of baghdad, 2010. 18. al-hassnawy a. socioeconomic and nutritional status in relation to oral health status and treatment needs in dewanyiah governorate among 12 years old school students. master thesis submitted to the college of dentistry, university of baghdad, 2013. 19. who. oral health surveys. basic methods, geneva 1997. 20. daniel ww. biostatistics: a foundation for analysis in the health science. 7th ed. new york: john wiley and sons, (1999). 21. who. the management of nutrition in major emergencies. world health organization geneva, 2000. 22. cdc growth charts. unit state. national center for health statistics in calibration with the national center for chronic disease prevention and health promotion, 2000. 23. who. oral health survey, basic methods. 3rd ed. geneva, 1987. 24. al-sheraidah s. dental anomalies in permanent teeth and associated etiological factors in relation to nutritional status in 15 years old students in basrah city/iraq. master thesis submitted to the college of dentistry, university of baghdad, 2015. 25. al-mugamis a. oral health status and treatment needs among fifteen years old students in maysan governorate/iraq. master thesis submitted to college of dentistry, university of baghdad, 2014. 26. murray j, nunn j, steel j. the prevention of oral disease. 4th ed. oxford, new york, 2003. j bagh college dentistry vol. 29(4), december 2017 dentition status among pedodontics, orthodontics and preventive dentistry 95 27. mahan l., escott-stump. krause’s food, nutrition and diet therapy .12p edp. saunders, an imprint of elsevier inc.2008. 28. cameron a, widmer r. handbook of pediatric dentistry. 3rd ed. mosby elesvir, 2008. 29. abdul razzaq q. oral health status among 15 year-old school students in sulaimania city-iraq. master thesis submitted to college of dentistry, university of baghdad, 2007. 30. ali d. oral health status and treatment needs among 12 year-old school children in urban and rural areas of baghdad-iraq. master thesis submitted to college of dentistry, university of baghdad, 2001. 31. al-khaza'ali a. oral health status and treatment needs among (612) scjool children in irbid city (jordan). master thesis submitted to college of dentistry, baghdad university, 2004. 32. al-sadam n. oral health status in relation to nutritional and social status in kerbal'a governorate for primary school students aged 12 years old. master thesis submitted to the college of dentistry, university of baghdad, 2013. مدينة في الغذائية لطالبات المدارس المرحلة المتوسطة بالحالة وعالقتها للفم واألسنان الصحية الحالة العراق-األشرف النجف الخالصة التغذية و النظام الغذائي يمكن ان يؤثر على التنمية و سالمة تجويف الفم و كذلك تطور امراض الفم مثل تسوس خلفية الموضوع : ة االسنان تليها امراض اللثة فهي بالرغم من انها ليست بامراض تهدد الحياة البشرية لكنها سائدة و واسعة االنتشارخاصة بالبلدان النامي بالعراق. كما هو الحال و قد اجريت هذه الدراسة لتقييم مدى شيوع و انتشار تسوس االسنان و عالقتهم بالحالة الغذائية بين فتيات المدارس هدف الدراسة : المتوسطة في مدينة النجف في العراق . سنة و تالفت 31و 31, 31 اجريت هذه الدراسة بين فتيات المدارس المتوسطة اللتواتي تتراوح اعمارهن بين المواد و الطرق : باستخدام القياسات الجسميه وفقا للرسم البياني للنمو تابعه لمراكز السيطره طالبة . تم اجراء تقييم الحالة الغذائية 511العينة الكلية من 3895عام (. وكان تشخيص وتسجيل تسوس االسنان وفقا لمعايير منظمة الصحه العالميه 0222عن االمراض والوقايه منها ) من اجمالي %5.17. اظهرت النتائج ان (bmi)باستخدام مؤشر كتلة الجسم (% 96.2الجيدة) التغذية بلغت نسبة انتشارالنتائج: ( في 2.18 ± 1.80) dmfs( و 3.55 ±2.31تساوي )dmft العينة لم يصابوا بالتسوس . و كان قيمة مؤشر متوسط االسنان اللبنية ( شوهدت فروق معنويه بين 162±..00.)) ,dmft2.32±1..9 dmfs (حين كان قيمة مؤشر متوسط االسنان الدائمية dmfs, dmft الغذائية الحالةالعكس مع والعمر في حين وجد. وبالتالي سنة 31-31التغذية بعمر لدى الطالبات االناث جيدي ان هذه الدراسه اظهرت ان نسبه عاليه من تسوس االسناناالستنتاج: تشجيع على المعرفه الصحيه باتجاه ايجابي.المن الضروري وضع الحاجه الى تحسين برامج الصحه العامه الوقائيه و hiba f.doc j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 93 clinical importance of gingival biotype (review of literature) hiba m. jameel, b.d.s. (1) maha sh. mahmood, b.d.s., m.sc. (2) abstract this review discusses the gingival biotypes, their characteristics, analysis based on the measurement of the dentopapillary complex. also discuss their response to inflammation, surgery, and ridge healing after tooth extraction, their influence in the behavior of the peri-implant tissue. (j bagh coll dentistry 2015; 27(3):93-101). introduction the gingival perspective depends on gingival complex, tooth morphology, contact points, hard and soft tissue considerations, and periodontal biotype (1). in 1969, ochsenbein & ross, indicated that there were 2 main types of gingival anatomy categorized into flat and highly scalloped (2). while claffey and shanley defined the thin tissue biotype as a gingival thickness of <1.5 mm, and the thick tissue biotype was referred to as having a tissue thickness 2 mm (measurements of 1.6 to 1.9 mm were not accounted) (3). the term ‘‘gingival biotype’’ was introduced by seibert and lindhe to categorize the gingiva into ‘‘thick-flat’ and ‘‘thin-scalloped’’ biotypes as shown in figure (1) (4). but becker et al .proposed three different periodontal biotypes whichare flat, scalloped and pronounced scalloped gingiva, measuring from the height of the bone interproximally to theheight at the direct midfacial, their findings are as follows:(flat= 2.1 mm,scalloped= 2.8mm, pronounced scalloped= 4.1 mm (5). the morphologic characteristics of the gingiva depends on several factors like the dimension of the alveolar process, the form of the teeth, events that occur during tooth eruption, the eventual inclination and position of the fully erupted teeth(6,7) . the gingival biotypes respond differently to inflammation, restorative, trauma and parafunctional habits (8). these traumatic events result in various types of periodontal defects which respond to different treatments. so it is believed that tissuebiotype is a critical factor that determines the result of dentaltreatment (9,10). (1) high diploma student, department of periodontics, college of dentistry, university of baghdad. (2) professor, department of periodontics, college of dentistry, university of baghdad. figure 1: gingival biotypes. gingival biotypes and their characteristics: it has been suggested in 1991 that the thick periodontal biotype was more prevalent (85%) than the thin scalloped form (15%) (11). studies showed that patients with thick-flat biotypes demonstrate short papillae whereas thin-scalloped biotypes show long papillae. this morphometric disparity could result in a more papilla loss in the latter. the other distinctive features of a tissue with thick biotypes include flat soft tissue and bony architecture, denser and more fibrotic soft tissue curtain, large amount of attached masticatory mucosa ,resistance to acute trauma and respond to disease with pocket formation and infra bony defect. moreover, the teeth with thick gingival biotype are more square in shape and shows flatter posterior cusps. the contact areas of adjacent teeth are larger facio-lingually and inciso-gingivally (12). while thin gingival biotypes are delicate, highly scalloped and translucent in appearance. the soft tissue appears delicate and friable with a minimal amount of the attached gingiva .the underlying bone is thin or minimal bone over the labial roots with possible presence of fenestrations and dehiscence. thin scalloped biotypes are considered at risk as they have been associated with a compromised soft tissue response following surgical and or restorative treatment. unlike in thick biotypes, the teeth are more triangular with steeper posterior cusps. the contact areas of adjacent teeth are small faciolingually and inciso-gingivally and are located j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 94 towards incisal or occlusal third (12) figure 2 (a & b) a)thick biotype(clinical picture) b) thin biotype. methods to determine gingival thickness: the gingival thickness can be assessed by: a. direct methods include: 1. probe transparency (tran) method periodontal probe inserted in the sulcus to evaluate gingival tissue thickness .it is the simplest way to determine gingival biotype; with a thin biotype, the tip of the probe is visible through the gingiva while in thick biotype is not. this method is minimally invasive& it was found to be highly reproducible with 85% intra examiner repeatability(13)(figure 3) . figure 3: probe transparency (tran) method. a) probe visible through the sulcus (thin biotype). b) probe not visible (thick biotype). 2. trans gingival probing (tgp): the gingival thickness was assessed by using a unc-15 probe or probe with the rubber stopper, gingival thickness was assessed at the measurement points (at midpoint of the labial attached gingiva and at the base of distal interdental papilla) 5 -20 minutes after injection .the measurements were then rounded up to the nearest millimeter, and carried out by a single periodontist (14,15) (figure 4). figure 4: trans gingival probing method (tgp) . a)the unc 15( university of north carolina screening probe) has millimeter markings at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,13, 14, and 15 millimeters and color coding at5 th ,10th ,and 15 th mm. b).intra oral photograph showing trans gingival probing method using a unc-15 probe at central incisor, lateral incisor and canine. the measurement points on the buccal gingiva were marked with a waterresistant marking pencil. kolte et al. in 2014 estimate gingival thickness using trans gingival probing method using an endodontic spreader fitted with a rubber stopper. after anesthetizing the facial gingiva gingival thickness was assessed midbuccally halfway between the mucogingival junction and the free gingival groove in the attached gingiva ,using an endodontic spreader fitted with a rubber stopper inserted perpendicularly into the gingival surface at the marked location. the stopper remained at the gingival surface while the spreader proceeded through the soft tissue until bone or cementum was hit, then removed and the distance between the rubber stopper and the tip of the spreader e was measured on the ruler. measurements were not rounded off to the nearest millimeter. the thickness of the gingiva was recorded only on the mid-facial aspect, as there could be existing variations in respect of mid-facial and interdental recordings, because the alveolar bone contours are different in these areas, which might influence the soft tissue (16) (figure 5). figure 5: measurement of thickness of gingiva using an endodontic spreader b. indirect methods: 1 .ultrasonic devices: j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 95 the use of ultrasonic devices to determine gingival thickness is a non-invasive method. the difficulty to determine the correct position for attaining reproducible measurements, and the unavailability and a high cost of the device limit the use of this method. kydd et al in 1971reported that ultrasonic devices appear to be the least invasive method and offer excellent validity and reliability (17). however, such devices are no longer available commercially; in addition, they make it difficult to both determine the correct position for accurate measurement and successfully reproduce measurements (18). ultrasound machine consist of ultrasound scan including a digital display, scan display, a transducer probe, built in printer and footswitch (figure 6). figure 6: dental ultrasound machine. in the study conducted by savitha et al in 2005, using (a-scan) probe with the frequency of 10 mhz., the intra oral transducer probe was adapted to the gingival surface coinciding with the bleeding points that created in trans-gingival probing . the ultrasonic measurement that done using a scan makes use of pulse echo principle. the mechanism of action of ultrasound based on the transit time for the pulse (ultrasound wave) travel to the bone (hard tissue) and echoed back creates spikes on the monitor immediately. utilizing the print out of this graph and with the help of the optical projector, the thickness of gingiva was determined (14) (fig. 7). figure 7: the intra oral transducer probe was adapted to the gingival surface (using (a-scan) probe with the frequency of 10mhz). rakhi et al in 2013 used ultrasound b-scan, the region of interest was scanned by an extra-oral probe and the frequency of b-scan was 10mhz. in the oral cavity, water was used as sound coupling medium between the probe and selected area for examination. the extra oral transducer probe adapted to the gingival surface coinciding with the bleeding points that created during trans-gingival probing method, the probe delivers ultrasonic waves at right angle to the tissues to be measured in the facial gingiva of anterior teeth.extra-oral ultrasonic transducer probe was used for the first time for the assessment of gingival thickness and measurements were made directly on the screen at the time of scanning,recorded to the nearest 0.1mm (15) (fig. 8) . figure 8:ultrasonic measurements using ultrasound b-scan . a) the region of interest was scanned by an extra-oral probe. the transducer probe was adapted to the gingival surface coinciding with the bleeding point created during trans gingival probing method. b) ultra sonogram of maxillary anterior region 2.stcbct (soft tissue –cone beam computed tomography): cone beam computed tomography is used to visualize and measure thickness of both hard and soft tissues and can be used for determining the width, height and distance to the anatomical structures of alveolar process in presurgical dental implant planning. in 2008, januário et al., developed soft tissue cone-beam computed tomography (st-cbct), to improve soft tissue image quality and allow the determination of the dimensions and relationships of the structures of the dentogingival unit(19). with these procedures, the patients were asked to wear a plastic lip retractor and to retract their tongues toward the floor of their mouths. this approach was called st-cbct., the soft tissues of the lips and cheeks were positioned away from the gingival tissue and the tongue remained lower in the oral cavity (figure 9). j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 96 figure 9: a) patient positioned for a regular cone-beam computed tomography (cbct) scan .b) the same patient positioned for the second cbct scan wearing the plastic lip retractor (soft tissue cbct) in an inverted position to avoid hitting the chin stabilizer.st-cbct allowed measurements of the distance of the gingival margin to the facial bone crest, the gingival margin to the cej, and width of the facial gingiva. it allowed a clear visualization, measurement of the dimensions, and analysis of the relationship of the structures of the periodontium and dentogingival attachment apparatus fig10 &11(19). figure 10: soft tissue cone-beam computed tomography measurements (st-cbct) (a) measurement of the thickness of the facial gingiva performed on the image of the patient with a thick periodontal biotype (soft tissue cone-beam computed tomography scan). (b), measurement of the distance of the gingival margin to the facial bone crest represents the biologic width. (c), measurement of the distance of the gingival margin to the cementoenamel junction. dotted lines represent the long axis of the tooth. many studies conducted using the st-cbct concluded that the soft tissue cone-beam computed tomography has great value on the evaluation of the dimensions and relations between the several periodontal structures and the complex of dento-gingival insertion (19-21). figure 11: comparison between the gingival biotypes in st-cbct measurements .a)thin biotype representing a gingival thickness under 1.5 mm in a soft tissue cone-beam computedtomography image. gingival thickness was assessed at 2 mm apical from the gingival margin. b) thick biotype representing a gingival thickness of over 1.5 mm in a soft tissue cone-beam computed tomography image. gingival thickness was assessed at 2 mm apical from the gingival margin. 3. parallel profile radiography (pprx ) parallel profile radiography used to analyze the dimensions of the soft and hard tissue structures in the coronal aspect of the periodontium around the index tooth, parallel profile radiographs were obtained from a lateral position with the use of lead plate, according to the method reported by alpisteillueca (22). all clinical oral examinations have been performed on the left central incisor (index tooth) both with direct measurements and analyses of a clinical photograph taken from the region of the index tooth. prior to the photograph, a lead plate (5.0 x 1.0 x 0.1 mm) was used as reference for all measurements on the photograph and the radiograph (23) (fig.12&13) figure 12: clinical view of index tooth with fixed transfer lead plate. j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 97 figure 13: bite block fixed with the anterior teeth so that the film was positioned on the lateral vestibule by paralleling orientation of the film towards the long axis of the tooth ,and this was achieved by viewing the lead plate through the aiming ring only the profile of the lead plate had to be seen. the following measurements were made on the radiographs: • thickness of the free gingiva: distance between the enamel surface to the palatal side of the lead plate measured at the coronal margin (g1) and the base (g2) of the free gingiva. • thickness of the gingiva at the supracrestal attachment: distance between the root surface and the palatal side of the lead plate measured at the cementoenamel junction (g3), the middle third (midpoint between the distance cej bone crest)(g4)and directly above the bone crest level (g5). • thickness of the attached gingiva: distance between the buccal margin of the bone crest and the palatal side of the lead plate(g6) • thickness of the buccal alveolar bone plate: distance between the buccal surface and the palatal side (lamina dura) of the buccal bone plate measured at the bone crest level (a1), at the border between the coronal and middle third (a2) ,and between the middle and apical third (a3) of the root length (fig.14). figure 14: parallel profile radiography. a) radiographic view. b) radiographic measurement points for assessment of gingival (g1–g6) and alveolar bone (a1– a3)thickness values. the limitation of this technique is that it cannot be used in posterior teeth and unhealthy periodontal tissues. since this study was on radiographic images, it was not possible to measure the length of either the junctional epithelium or the connective tissue attachment (22). c. analysis of the gingival biotype based on the measurement of the dentopapillary complex: the characteristics of gingival thickness, gingival width and subjacent alveolar bone thickness have been used as a base for the classification of periodontal biotypes. however, for some authors, use of the term periodontal phenotype more correct to describe features of the periodontium, which are influenced by both genetic and environmental factors (24). in recent studies, gingival thickness, gingival width and the shape of the dental crown are taken to relate & define the classification of periodontal biotype .the characteristics of gingival thickness, gingival width and subjacent alveolar bone thickness have been used as a base for the classification of periodontal biotypes (25). gingival biotype refers to an aggregate of four features of the soft tissues and the teeth they surround that build up to a specific picture (26). these are:: 1. the gingival width (keratinized tissue width): which refers to the width of the keratinized tissue when measured from the gingival margin to the muco-gingival junction. 2. gingival thickness (thick or thin): the thickness of the tissue in a bucco-palatal dimension. 3. papilla height (ph)/proportion: the part of the gingiva that fits in between teeth. 4. crown width/height ratio: long, slender teeth tend to be associated with contact points distant from the alveolar crest and long papillae that fill the embrasures. malhotra, et al. in 2014 correlated gingival biotype with dentopapillary complex. they recorded thefollowing parameters which were the same as recorded by lee et al. (27).these parameters are important to determine gingival biotype: • crown length (cl) was measured between the incisal edge of the crown and the free gingival margin, or if discernible, the cemento-enamel junction. • crown width (cw) i.e., the distance between the approximal tooth surfaces, was recorded at the border between the middle and the cervical portion. • papillary height (ph) was assessed to the nearest 0.5 mm using the same periodontal probe at the mesial and distal aspect of both central incisors. this parameter was defined as the distance from j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 98 the top of the papilla to a line connecting the midfacial soft tissue margin of the two adjacent teeth. the mean value will calculated for the three papilla. • papillary width (pw) was calculated at the base of papilla between two approximated tooth surfaces. • from canine to canine, the area of the facial papilla (ap), the facial surface area of the anterior tooth (at), the proportion of the dento-papillary complex (ap/at). data collected and the existence and correlation of different gingival biotypes and dentopapillary complex dimension has been confirmed. the results showed that average crown length was the best single determinant of biotype and area of papilla was the next best choice and highly significant correlation between gingival biotype and crown length and area of papilla (25,27). the results were similar to findings have been reported earlier by anand et al. who correlated the prevalence of thick and thin biotype with gender and tooth morphology (28). results showed that patients with slender tooth form have less crown width/crown length ( cw/cl),less gingival width (gw),and more papillary height (ph )resulting in thin gingiva. while subjects showed a more quadratic tooth form, more crown width/crown length (cw/cl), broad zone of keratinized tissue (gw), and low papillae (ph) showed thick gingival biotype as seen in figure 15 below. association of gingival biotype with the results of scaling and root planing: the concept of gingival biotype has been used as a predictor of periodontal therapy outcomes since the 1980s. scaling and root planing (srp) has been used in periodontal therapy. it includes the removal of plaque and calculus through repetitive instrumentation on the root surface. it is generally accepted that the dimensions of the gingiva in both the facial and interproximal areas shrink following scaling and root planning. although gingival shrinkage (gsh) after srp is a common complication in periodontal patients, few studies on gingival biotypes have focused on alterations of the gingivaafter srp using an a traumatic method to examine the gingival thickness. fu et al in 2011 proposed differences in the tissue reaction with each biotype, such that the thick gingiva is more prone to resulting in a periodontal pocket and the thin gingiva, in gsh after any type of trauma (29). in a new study done by yeon et al in 2013, prospective and controlled experiments were performed to compare periodontal pocket depth (ppd) reduction and gingival shrinkage (gsh) after scaling and root planing (srp) according to gingival biotype (30). it was found that the gingival biotype and ppd change after srp did not show a relationship.this means that other factors may have a greater impact than gingival biotype on the outcomes of srp. such factors may include the three-dimensional morphology of the alveolar crest, remained calculus and plaque, and individual healing potential. there were no differences in the gingival shrinkage in groups with a ppd over 3 mm. only normal gingival crevices, showed a significant difference, in which the thin gingiva had more gsh than the thick gingiva, and this could be interpreted in relation to the critical probing depth of nonsurgical therapy. this study suggested that the roles of gingival biotype in gsh and ppd after srp were undefined in cases of periodontitis. gingiva with a ppd over 3 mm failed to show a particular tendency in gsh and ppd by biotype. only the gingiva with a ppd of less than 3 mm showed more gsh in the thin biotype than the thick biotype (30). more studies will be needed to clarify the factors affecting the results of srp. gingival biotype and response to inflammation, surgery, and ridge healing after tooth extraction: it was suggested by kao et al. in 2002, that since these two tissue biotypes have different gingival and osseous architectures, they exhibit different pathological responses when subjected to inflammatory, traumatic, or surgical insults.these different responses dictate different treatment modalities (8). the tissue response to inflammation, surgery & ridge healing after extraction can be summarized in table1: j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 99 table 1: tissue response to inflammation, periodontal surgeries & tooth extraction comparison of tissue response to inflammation, periodontal surgeries &tooth extraction thick gingiva thin gingiva soft tissue to inflammation marginal inflammation, cyanosis, bleeding on probing, edemafibrotic changes thin marginal redness & gingival recession hard tissue to inflammation bone loss with pocket formation/infra bony defects rapid bone loss associated with soft tissue recession response to periodontal surgical procedures easy &predictable result with hard & soft tissue contouring difficult to predict where tissue will heal &stabilize regenerative periodontal procedures enhance blood supply to osseous structures compromise the blood supply ridge healing after tooth extraction minimal ridge atrophy ridge resorption in the apical & lingual direction influence of tissue biotype in the behavior of the peri-implant tissue: the current focus of implantology is the planning, besides the function, the esthetical success. the expectation is to create an esthetic restoration that is indistinguishable from the natural tooth, as well as returning the contour of peripheral structures (peri-implant mucosa and papilla) that resemble the same contralateral structures. the peri-implant tissues are directly or indirectly affected by five main large groups of determinants: 1 surgical (surgical trauma, implant position, use of graft or bone substitute and period of insertion) 2 prosthetic (type of provisionalization, shape, manipulation of components) 3 geometry of implants (macro geometry, interface implant/abutment and surface) 4 – systemic (smoking, diabetes, chemotherapy); 5 local factors (hygiene, maintenance, bone quantity and quality, periodontal disease, radiotherapy, type of edentulism, smoking and periodontal biotype ( 31-33). many studies have been conducted to evaluate the effect of gingival biotype on peri-implant tissues (18,34-38). souza et al., concluded from these studies that tissue biotype has influence on the esthetic in the therapy with implants, especially on the facial peri-implant mucosa levels; presenting the thin biotype greater susceptibility to recession, the conversion of a thin biotype into a thick biotype, through grafting of conjunctive tissue seems to positively influence on the level of facial marginal mucosa. on the other hand, the tissue biotype showed little or no influence on the height of the interproximal papilla .the papillary filling of the interproximal niche .the papilla behaves with extremely sensibility to trauma and it is fundamental on the composition of the periimplant morpho-functional and esthetic complex; therefore, it is suggested that each and every trauma must be avoided (39) (see figures 16&17). figure 16: thick biotype around implant. figure 17: thin biotype around implant. as conclusion; evaluation of gingival tissue biotypes is important in treatment planning. since thick and thin gingival biotypes are associated with thick and thin osseous patterns, the two tissue types respond differently to the inflammation and trauma and have different patterns of osseous remodeling following the extraction or implant procedure. by understanding the nature of the tissue biotype, the practitioner can employ appropriate periodontal and surgical procedures to minimize alveolar resorption and provide more favorable environment for implant placement. j bagh college dentistry vol. 27(3), september 2015 clinical importance oral and maxillofacial surgery and periodontics 100 references 1. ahmad i. anterior dental esthetics: the gingival perspective. br dental j 2005; 199:195-202. 2. ochsenbein c, ross s. a reevaluation of osseous surgery. dent clin north am 1969; 13(1): 87-102. 3. claffey n, shanley d. relationship of gingival thickness and bleeding to loss of probing attachment in shallow sites following nonsurgical periodontal therapy. j clin periodontol 1986; 13(7): 654-7. 4. seibert jl, lindhe j. esthetics and periodontal therapy. 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implantol 2012; 6(2): 56-66. suha final.doc j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 94 immunohistochemical expression of p16 and her2/neu in normal oral mucosa, oral epithelial dysplasia, and oral squamous cell carcinoma suha ali ahmed, b.d.s. (1) ahlam hameed majeed, b.d.s., m.sc. (2) abstract background: oncogenesis in the oral cavity is widely believed to result from cumulative genetic alterations that cause a transformation of the mucosa from normal to dysplastic to invasive carcinoma. the p16 gene produces p16 protein, which in turn inhibits phosphorylation of retinoblastoma (rb), p16 play a significant role in early carcinogenesis. a number of epidermal growth factor receptor (egfr) family, her2/neu, has received much attention because of its therapeutic implications. the aims of the study were to evaluate and compare the immunohistochemical expression of the cell cycle protein p16 ink4a and c-erbb2 (her2/neu) in nom, oed, and oscc. correlate both marker expression with each other as well as with various clinicopathological findings. materials and methods: sixty two formalin-fixed, paraffin embedded tissue blocks (20 cases of normal oral mucosa, 17 cases of oral epithelial dysplasia, and 25 cases of oral squamous cell carcinoma) were included in this study, an immunohistochemical staining was performed using anti p16 monoclonal antibody, and anti her2/neu polyclonal antibody. results: positive ihc expression of p16 was found in 18 cases (90%) of nom, 16 cases (94.1%) of oed and in 20 cases (80%) of oscc. positive ihc expression of her2/neu was almost undetectable in nom, while it was found in 9 cases (52.9%) of oed, and in 15 cases (60%) of oscc.the correlation between the expression of both markers were statistically highly significant in nom, significant in oed, and non significant in oscc. conclusions: this study signify the important role of p16 and her2/neu in oral carcinogenesis and in the evolution of the mucosa from normal to dysplastic to invasive carcinoma keywords: nom, oed, oscc, p16, her2/neu. (j bagh coll dentistry 2014; 26(2): 94-98). الخالصھ التي تحول الغشاء المخاطي الفموي و بخطوات عدیده من الطبیعي الى الحثل النموي عملیة التسرطن في التجویف الفمي غالبا ما تحدث نتیجة تراكم التغییرات الجینیھ : الخلفیھ یلعب دورا مھما في عملیة p16وكذلك فان بروتین , rbلمقابل یمنع فسفرة بروتین الذي في ا p16فھو ینتج بروتین p16 المورث الجیني.الطالئي ثم النسیج السرطاني المتغلغل . والذي حظي اھتماما كبیرا بسبب تطبیقاتھ العالجیھ) egfr( فھو أحد افراد عائلة مستقبالت عامل نمو خالیا األدمھ her2/neu أما .التسرطن المبكر و الحثل النموي الطالئي الفموي ,في النسیج المخاطي الفموي الطبیعي her2/neuومحفز p16 ink4aسیجي الكیمیائي لبروتین تقییم التعبیر المناعي الن :اھداف الدراسھ مع المقاییس السریریھ والمرضیھ مع بعضھما وكذلك عالقتھما her2/neuو p16 وكذلك اكتشاف عالقة المورثات الجینیھ . وسرطان الفم الحرشفي , حالھ من الحثل النموي الطالئي الفموي 17حالھ من الغشاء الفموي الطبیعي و 20تضمنت , تشمل الدراسھ اثنان وستون حالھ مختاره من قوالب شمع البارافین:اد وطرق العمل المو . her2/neu و p16و اجراء الفحوصات المناعیھ الكیمیائیھ النسیجیھ باستخدام المؤشرات .حالھ من سرطان الفم الحرشفي 25و من الغشاء الفموي الطبیعي و الذي اظھر تعبیر %)90(حالھ 18كان قد تبین في p16لبروتین اظھرت الدراسھ الحالیھ ان التعبیر االیجابي المناعي النسیجي الكیمیائي: لنتائج ا من سرطان %) 80(حالھ 20في p16بینما كان التعبیر االیجابي لبروتین . ,لطالئي الفموي من الحثل النموي ا%) 94.1(حالھ 16كما وظھر التعبیر االیجابي في , ایجابي ضعیف قد تبین her2بینما في الحثل النموي الطالئي الفموي كان الظھور االیجابي ل محفز , لم یتم الكشف عنھھ في الغشاء الفموي الطبیعي her2التعبیر االیجابي لمحفز .الفم الحرشفي p16العالقھ االحصائیھ بین المؤشرین .من سرطان الفم الحرشفي%) 60 (حالھ 15كان قد وجد في her2بینما التعبیر االیجابي لمحفز , %)52.9( حاالتفي تسع حین انھ لم تكن ھناك عالقھ معنویھ بین المؤشرین في , وكذلك كانت العالقھ معنویھ في الحثل النموي الطالئي الفموي , كانت معنویھ للغایھ في الغشاء الفموي الطبیعي her2/neuو .في سرطان الفم الحرشفي في عملیة التسرطن وكذلك في تطور الغشاء المخاطي الفموي من الطبیعي الى الحثل النموي her2/neuومحفز p16كشفت ھذه الدراسھ على الدور المھم لبروتین :االستنتاجات . ثم الى سرطان الفم الحرشفي introduction oral carcinogenesis is a multi-step process involving gene mutations and chromosomal abnormalities (1). the transition from normal oral epithelium to oral dysplasia and cancer results from accumulated genetic and epigenetic alterations (2). the best-known precursor lesion is epithelial dysplasia, which is histologically detectable and often presents clinically as white or red mucosal patches called leukoplakia and erythroplakia (3). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. oral cancers account for nearly 3% of all malignancies, and they are the sixth cancer by incidence worldwide, with epidemiologic variations existing between different geographic regions (4-6). the cell cycle protein (p16) is a well-known tumor suppressor protein, composed of 156 amino acids encoded by a three exons of the p16 gene. it regulates the rb tumor suppressor pathway by keeping rb in a hypophosphorylated state, which further promotes the binding of e2f to achieve g1 cell-cycle arrest. (7-9). the transmembrane tyrosine kinase receptor constitute the erbb receptor family and comprised of four di erent receptors known as erbb1 (also referred to as (egfr), erbb (her2/neu in rodents), erbb3 (her3), and erbb4 (her4) (10j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 95 12). c-erbb-2proto-oncogene (her/neu/neu) encodes a 185 transmembrane protein product of tyrosine kinase family, with an extensive homology to the epidermal growth factor receptor (13) and can be activated by hetero oligomerization with the other members of the erbb family (14). the lack of a unique marker of oscc has long been a problem in the early detection of oscc. it would be necessary to discover more reliable and efficient markers to characterize the malignant transformation of oral epithelium (15, 16). this study aimed to evaluate and compare the expression of p16 and her2/neu in normal oral mucosa, oral epithelial dysplasia, and oral squamous cell carcinoma, and to correlate both marker expression with each other, as well as with various clinicopathological findings including (age, sex, clinical presentation, tumor site, tumor grade). materials and methods the study samples included sixty two formalin-fixed, paraffin embedded tissue blocks (20 nom, 17 oed, and 25 oscc) dated from (1975 till 2013), were obtained from the archives of the department of oral & maxillofacial pathology/ college of dentistry/ university of baghdad; al-shaheed ghazi hospital/ medical city / baghdad; and al kadhimiya teaching hospital. sections of 4µm thickness were mounted on normal glass slides, stained with h&e and histopathologically re-evaluated. four other 4µm thick sections for each case were cut and mounted on positively charged slides (fisher scientific and escho super frost plus, usa) for immunohistochemical staining with monoclonal antibody p16 using abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit (catalog no. ab54210, cambridge, uk). and polyclonal antibody her2/neu using rabbit antihuman c-erbb-2 oncoprotein (catalog no. a 0485) dako denmark immunohistochemical detection kit was used. results positive p16 immunostaining was detected as brown nuclear or (nuclear and cytoplasmic) expression. ihc staining of p16 in nom reveals that 2 cases (10%) showed negative expression, 18 (90%) cases showed weak positive expression. and in oed, 1 case (5.9%) showed negative expression, 1 case (5.9%) showed weak positive expression, 6 cases (35.3%) showed moderate positive expression, and 9 cases (52.9%) showed high positive expression. while in oscc, ihc staining of p16 reveals that 5 cases (20%) showed negative expression, 3 cases (12%) showed weak positive expression, 2 cases (8%) showed moderate positive expression, and 15 cases (60%) showed high positive expression. fig (1,2,3) positive her2/neu immunostaining was detected as brown membranous or (membranous and cytoplasmic) expression. regarding her2/neu expression in nom, all cases (100%) showed negative expression. and in oed, 8 cases (47.1%) showed negative expression, 5 cases (29.4%) showed weak positive expression, and 4 cases (23.5%) showed strong positive expression. while in oscc her2/neu immunostaining reveals that 10 cases (40%) showed negative expression, 10 cases (40%) showed weak positive expression, and 5 cases (20%) showed strong positive expression. fig (4,5,6). regarding the correlation between p16 and her2/neu expression in each group and according to mann-whitney u test, the results revealed a statistically highly significant correlation in nom (p-value= 0.000), and significant correlation in oed (p=0.02), while the results revealed non significant correlation in oscc (p=0.14). as clarified in table (1). regarding groups’ comparison in each marker, the results revealed statistically highly significant correlation (p=0.000). as clarified in table (2). figure 1: positive nuclear expression of p16 in nom (40x). figure 2: positive nuclear & cytoplasmic expression of p16 in severe dysplasia (40x). j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 96 figure 3: positive nuclear expression of p16 in moderately differentiated scc,(40x). figure 4: negative her2/neu expression in nom (tongue) (40x) figure 5: positive membranous & cytoplasmic expression of her2/neu in severe dysplsia (10x). figure 6: positive membranous & cytoplasmic expression of her2/neu in moderately differentiated scc (10x) table 1: descriptive statistics and markers’ comparison in each group groups markers descriptive statistics comparison n mean s.d. s.e. mann-whitney u test p-value nom p16 20 12.05 5.86 1.31 -3.93 0.000 (hs) her2 20 4.65 2.98 0.67 ed p16 17 62.24 32.98 8.00 -2.36 0.02 (s) her2 17 32.24 30.93 7.50 scc p16 25 52.20 36.16 7.23 -1.47 0.14 (ns) her2 25 31.88 29.71 5.94 table 2: descriptive statistics and groups’ comparison in each marker markers groups descriptive statistics comparison n mean s.d. s.e. kruskal-wallis test p-value p16 nom 20 12.05 5.86 1.31 20.66 0.000 (hs) ed 17 62.24 32.98 8.00 scc 25 52.20 36.16 7.23 her2/neu nom 20 4.65 2.98 0.67 18.29 0.000 (hs) ed 17 32.24 30.93 7.50 scc 25 31.88 29.71 5.94 discussion this study is not a large epidemiological one that expressed the incidence and prevalence of different clinicopathological features of oed and oscc, however, there was a close correlation between the present data and other published data concerning the incidence of oed and oscc in j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 97 iraq in the past studies records and studies in other parts in the world (17,18). assessment of p16 immunohistochemistry the results of the present study showed that positive immunostaining of p16 was found in 90% of normal oral mucosa cases with variable nuclear and cytoplasmic expression. this result agrees with tarakji et al. (19). as p16 is involved in cell cycle regulation its expression may vary with cell turnover times in the oral mucosa which have been shown to be variable in different types of oral mucosa (20). the activation of p16 expression can be triggered by dna damage, oncogenic stress or physiological aging (21). concerning oed cases the results of this study showed that positive expression of p16 was observed in (94.1%) of oed cases. regarding correlation between p16 and clinicopathological features, there was statistically non significant correlation, which agreed with bradley et al. (22). p16 positivity was found in (80%) of oscc cases. concerning the correlation between clinicopathological findings of oscc cases and p16, the present study showed statistically significant correlation between p16 expression and the tumor site. while there was non significant difference between p16 with age, sex, site, and grades of oscc (23,24). these differences due to limited sample size of this study. different cancer-causing agents may lead to p16ink4a gene inactivation as well as altered p53 and prb tumor suppressive pathways (25,26). these changes may result in either loss or overexpression of p16ink4a in oral dysplasia and oscc. hpv oncogenes are frequently found in oropharyngeal squamous cell carcinomas that display concomitant increased p16 ink4a expression (27,28). other relevant etiopathological agents that may influence p16 ink4a expression are smoking and smoke-less tobacco use (19,27). the oral mucosa of smokers, express p16 ink4a more frequently when compared to individuals that do not use tobacco, and this could be attributed to the component of tobacco smoke (nicotine), which is well known to significantly stimulate cell growth, epithelial cell dna synthesis and cell proliferation that stimulated at nicotine concentrations lower than those obtained in blood after smoking (27,29). assessment of her2 / neuimmunohistochemistry the present study showed negative her2/neu immunoreactivty in normal oral mucosa. and in oed it was found in (52.9%). these results were in agreement with jubair (18) that showed her2/neu expression in nom was almost undetectable. according to clinicopathological correlation of her2/neu and oed, the results of this study showed statistically non-significant correlation, which agrees with jubair (18). her2/neu positivity was found in (60%) of oscc cases. agree with (18) that showed higher her2/neu expression in the oscc group. the overexpression of her2/neu could be a potential useful marker in distinguishing noncancer and cancer, as shown in this study. once the overexpression of her2/neu is found in cases with benign or precancerous lesions in the oral cavity, care should be taken in the follow-up of such patients. early treatment with excision of the ed showing expression of her2/neu may be required (30,31). activation of egfr family by a variety of ligands is necessary for normal growth and differentiation (32). the present study showed statistically highly significant correlation between p16 and her2/neu in nom, and significant correlation between them in oed, and showed statistically non significant correlation between them in oscc. correlation between p16 and her2/neu in each group this is the first study in iraq and other parts in the world assessing the correlation between p16 and her2/neu immunohistochemical expression in nom, oed, and oscc. since this is a pioneer research in assessing that correlation, so the comparison could be withdrawn from other studies using another technique ,which is agree with (33) that showed there was non-significant correlation between p16 deletion and her2/neu amplification in oral squamous cell carcinoma by using fluorescent in situ hybridization. the present study showed highly significant correlation in each marker regarding groups’ comparison. this means that p16 and her2/neu play a role in oral carcinogenesis. references 1. barnes l, eveson jw, reichart p, sidransky d (eds). tumours of the oral cavity and oropharynx pathology & genetics. head neck tumors. lyon: iarc press 2005; 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84: 259-65. 14. silva sd, agostini m, nishimoto in, coletta rd, alves fa, lopes ma, et al. expression of fatty acid synthethase, erbb2 and ki67 iead and neck squamous cell carcinoma. a clinicopathological study. oral oncol 2004; 40(7): 688-96. 15. chang f, syrjanen s, syrjanen k. implications of p53 tumor suppressor gene in clinical oncology. j clin oncol 2002; 13: 1009-22 16. hung kf, lin sc, liu cj, chang cs, chang kw, kao sy. the biphasic differential expression of the cellular membrane protein, caveolin-1, in oral carcinogenesis. j oral pathol med 2003; 32(8): 461–7. 17. regezi. oral pathology. clinical pathologic correlations. 5th ed. st. louis, missouri. elisver saunders; 2008. 18. jubair kk. a comparative study of immunohistochemical expression of moesin, cytokeratin 14, mmp7 in oral squamous cell carcinoma and oral verrucous carcinoma. a master thesis, department of oral diagnosis, college of dentistry, university of baghdad, 2013. 19. tarakji b, kujan o, nassani mz. an immunohistochemical study of the distribution of p 16 protein in oral mucosa in smokers, non-smokers and in frictional keratosis. med oral patol oral cir bucal 2010; 15(5): e681-4. 20. thomson pj, potten cs, appleton dr. mapping dynamic epithelial cell proliferative activity within the oral cavity of man: a new insight into carcinogenesis? br j oral maxillofac surg 1999; 37: 377-83. 21. witkiewicz ak, knudsen ke, dicker ap, knudsen es. the meaning of p16 ink4a expression in tumors: functional significance, clinical associations and future developments. cell cycle 2011; 10(15): 2497-503. 22. bradley kt, budnick sd, logani s. immunohistochemical detection of p16ink4a in dysplastic lesions of the oral cavity. mod pathol 2006; 19(10):1310-6. 23. abrahao ac, bonelli bv, nunes fd, dias ep, cabral mg. immunohistochemical expression of p53, p16 and htert in oral squamous cell carcinoma and potentially malignant disorders. braz oral res 2011; 25(1):34-41. 24. chen yw, kao sy, yang mh. analysis of p16ink4a expression of oral squamous cell carcinomas in taiwan: prognostic correlation without relevance to betel quid consumption. j surg oncol 2012; 106(2): 149–54. 25. de oliveira lr, ribeiro-silva a, zucoloto s. prognostic impact of p53 and p63 immunoexpression in oral squamous cell carcinoma. j oral pathol med 2007; 36(4):191-7. 26. karsai s, abel u, roesch-ely m, affolter a, hofele c, joos s, et al. comparison of p16(ink4a) expression with p53 alterations in head and neck cancer by tissue microarray analysis. j pathol 2007; 211(3): 314-22. 27. greer jr ro, meyers a, said sm, shroyer kr. is p16 (ink4a) protein expression in oral st lesions a reliable precancerous marker? int j oral maxillofac surg 2008; 37(9): 840-6. 28. vidal l, gillison ml. human papillomavirus in hnscc: recognition of a distinct disease type. hematol oncol clin north am 2008; 22(6):1125-42. 29. angiero f, berenzi a, benetti a, rossi e, del sordo r, sidoni a, et al. expression of p16, p53 and ki-67 proteins in the progression of epithelial dysplasia of the oral cavity. anticancer res 2008; 28(5a): 2535-9. 30. cobleigh ma, vogel cl, tripathy d. multinational study of the humanized anti-her2 monoclonal antibody in women who have her2 overexpressing metastatic breast cancer that has progressed after chemotherapy for metastatic disease. j clin oncol 1999; 17(9): 2639–48. 31. ciardiello f, tortora g. a novel approach in the treatment of cancer: targeting the epidermal growth factor receptor. clin cancer res 2001; 7(10): 2958– 70. 32. rautava j, jee kj, miettinen pj, nagy b, myllykanga s, odell ew, et al. erbb receptors in developing, dysplastic and malignant oral epithelia. oral oncol 2008; 44(3): 227-35. 33. al-musawy ha. detection of her2/neu & p16 genes in oral squamous cell carcinoma using fluorescent in situ hybridization (fish). a master thesis, department of oral diagnosis, college of dentistry, university of baghdad, 2012. ban f.doc j bagh college dentistry vol. 25(2), june 2013 localization of transforming oral diagnosis 66 localization of transforming growth factor-beta expression in the peri-implant tissues of dental implants coated with placental collagen athraa y. alhijazi, b.d.s., m.sc., ph.d. (1) basim mohammed khashman b.sc., m.sc. (2) ban abdul ghani, b.d.s., m.sc., ph.d. (3) eman isaa, b.d.s., m.sc., ph.d. (4) abstract back ground : the transforming growth factor beta (tgfb) signaling pathway is involved in many cellular processes in both the adult organism and the developing embryo including cell growth, cell differentiation, apoptosis. the interaction between implant material and surrounding tissues is believed to play a fundamental role in implant success and illustrates different expression of growth factors by different cells that involved in the formation of periimplant tissue. the aim of this study was to localize expression of tgf b by newly formed bone tissue around surface-conditioned implants with placental collagen at different time intervals: 3 ,7,14,28, and 56 days . materials and methods: commercially pure titanium (cpti) implants coated with collagen protein were placed in the tibia of 20 new zealand rabbits . immunohistochemical study for localization of tgf b in peri –implant tissue for interval periods 3 ,7,14,28, and 56 days was performed under light microscope.. results: positive expression of transforming growth factor b can be detected in osteoblast, osteocyte, newly deposited matrix includes collagenous tissue and non mineralized osteoid tissue. endothelial cells line blood vessel showed positivity too. minerlized bone trabeculae and mature bone illustrate negative expression. conclusion: the present study suggests that placental collagen, coated ti implant illustrates positive expression of transforming growth factor b by osteoblast and endothelial cell that enhanced bone formation. key words: transforming growth factor, dental implant, bone. (j bagh coll dentistry 2013; 25(2):66-69). introduction transforming growth factor-beta (tgf-beta) is a multifunctional cytokine, whose numerous cell and tissue activities include cell-cycle control, the regulation of early development, differentiation, extracellular matrix formation, hematopoesis, angiogenesis, chemotaxis, immune functions, and the induction of apoptosis.(1) titanium (ti) surface modifications aiming to increase implant osseointegration is one of the most active research areas in dental implantology (2). many studies concerned with surfaceconditioned dental implants (3), include implants coated with collagen increases bone formation and implant stability, compared with uncoated controls. data analysis suggests that collagen has a positive influence on bone formation of endosseous heal (4). recent researches studied the role and the expression of growth factors in peri implant tissues include tgf b (5), vegf (angiogenesis) during early bone formation (6,7). (1)professor, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant lecturer, department of oral diagnosis, college of dentistry, university of baghdad. (3) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. (4) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. materials and methods materials ß commercially pure titanium (cpti) implant from friatec ag company in diameter 3.5 mm and 8mm in length (5mm threaded and 3 mm flat). ß placental collagen protein (n0. c-7521, sigma p). ß rabbit polyclonal to transforming growth factor (tgf) beta 3 from abcam company uk (ab15537). rabbit specific hrp/dab detection kit from abcam company (england) (ab80436). methods twenty new zealand rabbits, age (10-12 months) were used to insert cpti implant coated with collagen in their tibea. each 4 animals were sacrificed at interval periods 3 ,7, 14, 28, and 56 days. immunohistochemical investigation sections of 5µm thickness of paraffin embedded specimens for all study animals were carried for immunohistochemical localization of tgf b, examined under light microscope and in accordance with manufacturer instruction. positive reading was indicated when the cells display a brown cytoplasmic pigmentation staining, while negative reading was indicated for absence of immunostaining. j bagh college dentistry vol. 25(2), june 2013 localization of transforming oral diagnosis 67 results expression of tgf b in peri-implant tissue of dental implant coated with collagen shows positive chromogen dab by collagen mesh and endothelial cells of blood vessel after 3 days post operation period, figures (1, 2). at 7 day duration, positive expression of tgf b localized in newly deposit collagen fibrous tissue and in osteoblast cells in woven bone, figure (3). figures (4, 5) illustrate positive expression of tgf b by osteoblast and osteocyte ,while bone trabeculae and basal bone showed negative dab stain .this findings related to dental implant coated with collagen for 14 days duration. at 28 day post operation period, positive expression of tgf b identified in osteoid tissue while negative result illustrated in bone trabeculae and basal bone by staining with hematoxylin counter stain, figures (6, 7). at 56 day post operation period , osteoblast cells rimming bone surface,osteocyte and reticular connective tissue showed positive expression for tgf b .while basal bone and thread illustrate negative dab stain. figure 1: immunohistochemical view for positive identification of expression of tgf b in threads (arrow) of ti implant coated with collagen, 3 days duration post operation.dab chromogen with hematoxylin counter stain ×20. figure 2: magnifying view for previous figure (1) shows positive expression of tgf b in endothelial cell(arrow head) in blood vessel(bv), and in collagen mesh(arrow). dab chromogen with hematoxylin counter stain ×40 . figure 3: positive expression of tgf b by proliferative osteoblast in woven bone(wb) and fibrous tissue(ft) of ti implant coated with collagen, 7 days duration post operation.dab chromogen with hematoxylin counter stain ×10. figure 4: immunohistochemical view illustrates negative expression of tgf b by bone trabeculae(tb), and basal bone(bb).while osteoid tissue around shows positivity. ti implant coated with collagen,14 days duration post operation. dab chromogen with hematoxylin counter stain ×10 . j bagh college dentistry vol. 25(2), june 2013 localization of transforming oral diagnosis 68 figure 5: magnifying view for previous figure (4) shows positive expression of tgf b by prolifrative osteoblast (ost) and osteocyte(oct). dab chromogen with hematoxylin counter stain ×20 . figure 6: negative expression of tgf b in bone trabeculae (bt) and basal bone (bb) ,while osteoid tissue (ot) shows positivity. ti implant coated with collagen, 28 days duration post operation.dab chromogen with hematoxylin counter stain ×10 . figure 7: magnifying view for previous figure (6) shows negative expression of tgf b in bone trabeculae (bt) and basal bone (bb) ,while osteoid tissue (ot) shows positivity.dab chromogen with hematoxylin counter stain ×20 figure 8: mature bone of ti implant coated with collagen, 56 days duration post operation ,shows well developed threads (arrow), positive dab for tgf b by osteocyte (oct) and content of haversian canal (hc) . dab chromogen with hematoxylin counter stain ×20. figure 9: magnifying view ,illustrates haversian canal (hc), positive dab stain for expression of tgf b by osteoblast (ost) , reticular tissue(rt), and osteocyte (oct) within mature new bone. dab chromogen with hematoxylin counter stain ×40. discussion the distribution patterns of the cells were examined on surface of the titanium-dental implant with studied of adaptive cellular responses to the implant material include alterations in the cytoskeleton, integrin expression, synthesis of extracellular matrix proteins and cytokines like tgf b (8) . successful attachment on artificial surface is prerequisite for inducing new bone formation locally at the site of implantation. protein-coated surfaces may influence the biocompatibility of j bagh college dentistry vol. 25(2), june 2013 localization of transforming oral diagnosis 69 implant materials by initiating and supporting osteogenesis (9). collagen, fibronectin, vitronectin or mixtures of natural extracellular matrix proteins are the mostly investigated proteins for this purpose (10,11). the present findings illustrate a positive expression of tgf b by collagen mesh at 3 day post-operative duration, which coincide with results of holmes et al (12) and verrecchia and mauviel (13) ,who reported that tgf-β has been characterized as a cytokine that plays a vital role in driving fibrosis via promoting induction of matrix proteins, including type i collagen,and as a key player in fibrogenesis o`toole et al.(14) demonstrated that osteoinductive protein such as bone sailoprotein, fibronectin and collagen that coated surfaces of implant may stimulate adherence of osteoblas to its surface. these results coincide with present results which show positive expression of tgf b by osteoblast in different osseointegretion periods ,and this may attributed that, osteoblasts is upregulated by hormones and cytokines that promote bone formation as demonstrated by transforming growth factor-beta .in addition, our results presented a set of evidences that coating cpti with collagen may stimulate bone formation at the cellular and molecular levels, include positive expression of tgf b by endothelial cells and by unminerlized osteoid tissue .while mineralized bone shows negative dab stain ,and this may be related to tgf-β role as one of the most important factors in the regulation of the production of newly formed tissue during early healing periods represented by it's positive expression by endothelial cells and haversian canal content of established, well developed bone. references 1. schuster n, krieglstein k. mechanisms of tgf-betamediated apoptosis. cell tissue res 2002; 307(1):114. 2. sverzut at, crippa ge, morra m, de oliveira pt, beloti mm, rosa al.effects of type i collagen coating on titanium osseointegration: histomorphometric, cellular and molecular analyses. biomed mater 2012; 7(3): 035007. 3. stadlinger b, lode at, eckelt u, range u, schlottig f, hefti t, mai r. surface-conditioned dental implants: an animal study on bone formation. j clin periodontol 2009; 36(10):882-891. 4. stadlinger b, bierbaum s, grimmer s, schulz mc, kuhlisch e, scharnweber d, eckelt u, mai r. increased bone formation around coated implants. j clin periodontol 2009; 36(8):698-704. 5. comelini r, rubini c, fioroni m, favero g ,rita s,adriano p.transforming growth factor-beta 1 expression in the peri-implant soft tissues of healthy and failing dental implants. j periodontol 2003; 74(4): 446-450. 6. scardina ga,pisano a,messina m, rallo a, messina p. in vivo evaluation of the vascular pattern in oral peri-implant tissues. archives of oral biology 2011; 56(2):148-152. 7. ziebart t, schnell a, walter c, kämmerer pw, pabst a, lehmann km, ziebart j, klein mo, al-nawas b. interactions between endothelial progenitor cells (epc) and titanium implant surfaces. clin oral investig 2013; 17(1): 301-309. 8. hilbig h,kirsten m, rupietta r ,graf h,thalhammer s. implant surface coated with sialoprotein ,collagen and fibronectin and their effects on cells derived from human maxillar bone. eur j med res 2007; 12: 6-12. 9. sodek j, mckee md .molecular and cellular biology of alveolar bone. peridontol 2000 2000; 24:99-126. 10. lacouture me, schaffer jl, klickstein lb .a comparison of type i collagen, fibronectin, and vitronectin in supporting adhesion of mechanically strained osteoblasts. j bone miner res 2002; 17: 481492. 11. salih e, wang j, mah j, fluckiger r .natural variation in the extent of phosphorylation of bone phosphoproteins as a function of in vivo new bone formation induced by demineralized bone matrix in soft tissue and bony environment. biochem j 2002; 364:465-474. 12. holmes a, abraham dj, sa s, shiwen x, black cm, and leask a.ctgf and smads, maintenance of scleroderma phenotype is independent of smad signaling. j biol chem 2001; 276(14):10594–10601. 13. verrecchia f, mauviel a.transforming growth factorbeta and fibrosis. world j gastroenterol 2007; 13: 3056–3062. 14. o`toole gc, salih e, gallagher c, fitzpatrick d, o`higgins n, o`rourke sk. bone sialoprotein-coated femoral implants are osteoinductive but mechanically compromised. j orth res 2004; 22: 641-646. 9. widad f.docx j bagh college dentistry vol. 27(4), december 2015 the evaluation of restorative dentistry 52 an evaluation of olive oil as a separating medium and its effect on some mechanical properties of processed acrylic resin denture base (a comparative study). part two akhlas zaid al-ta’ie, b.sc., m.sc.(1) widad abdul-hadi al-nakkash, b.d.s., h.d.d., m.sc. (2) farhan dakhil salman, b.sc., m.sc. (3) abstract background: during acrylic resin processing, the mold must be separated from the surface of the gypsum to prevent liquid resin from penetrating into the gypsum, and water from the gypsum seeping into the acrylic resin. for many years, tin foil was the most acceptable separating medium, and because it's difficult to apply, a tin-foil substitute is used. in this study, olive oil is used as an alternative to tin foil separating medium for first time, and evaluating its effect as a separating medium on some mechanical properties such as (indentation hardness and transverse strength) of acrylic resins denture base comparing it with those processed using tin-foil and tin foil substitute such as (cold mold seal) separating medium. materials and methods: one hundred twenty four acrylic resins samples (124) were prepared falling in two main groups: (heat and cold-cured acrylic denture base resins), for each group three types of separating medium were used and five tests (10 samples) for each test were carried out, and (4) samples for the chemical composition. results: tin foil is one of the most satisfactory separating media in getting the best properties when using it as a separating medium, while, a statistically no-significant difference have been noticed between olive oil and coldmold seal samples concerning mechanical properties of tested groups. infrared spectroscopy analysis showed that, no changes were found in the chemical composition of both heat and cold-cured acrylic resins denture base after using olive oil as a separating medium. conclusion:the present study concluded that olive oil may be used as a substitute for tin foil and cold – mold seal separating medium in processing both heat and cold – cure acrylic resin denture base. keywords: acrylic resin separatingmedium olive oil, mechanical properties. (j bagh coll dentistry 2015; 27(4):52-61). introduction separating medium is a coating applied to a surface serving to prevent a second surface from adhering to the first, or a material, usually applied on an impression to facilitate removal of the cast(1).if the surface of the mold is not coated with a separating material, it will be found, that a layer of gypsum impregnated with polymer remains attached to the surface of the denture and is extremely difficult to remove(2). then it is an improperly contoured, and hence it leads to produces an unaesthetic and poorly fitting denture base (3). therefore; separating medium must be applied to the surface of the mold. many authors consider that tin foil is the best separating medium, however it is difficult to apply, tedious, and time-consuming. as a result, the solution is sometimes referred to as a tin foil substitute have been developed(4).a tin foil substitute is a film forming material that is painted on the mold surface thus preventing absorption the liquid acrylic denture base resin and at the same time sealing pores of the artificial stone (5). (1)lecturer. college of health and medical technology. (2)professor. department of prosthodontics. college of dentistry, university of baghdad. (3)assistant professor. college of health and medical technology. nowadays, tin foil substitute can be used successfully if all wax residuesare carefully cleaned from the pores of the stone and the tin foil substitute is carefully applied (3). a variety of materials can be used as a tin foil substitute, the most popular of separating agents are water-soluble alginates which produce a very fine film on the applied surface(6). the present study is designed to evaluate olive oil as a separating medium and its effect on some mechanical properties of the processed acrylic resin denture base when compared to those processed with tin foil and alginate mold seal (cold-mold seal) separating media. materials and methods metal pattern preparation: two different metal patterns were constructed with two dimensions to save time and effort(figure 1).dimensions and shape of each metal pattern were made according to the required tests. j bagh college dentistry vol. 27(4), december 2015 the evaluation of restorative dentistry 53 figure (1): metal patterns. a. indentation hardness test, b. transverse strength test samples grouping: a total of 124 samples prepared and used during the present study. the samples were divided into (2) groups (according to the types of acrylic resin). each group consisted of (62) samples, and these (62) samples were subdivided according to the types of separating medium used in curing process. these separating media were of (21) samples from tin foil, (20) samples from cold-mold seal, (21) samples from olive oil. and each separating medium were subdivided (according to the tests) used in the present study, (10) samples were made for each of the following tests except (4) samples for testing the chemical composition. 1. ten samples for indentation hardness. 2. ten samples for transverse strength. 3. four samples for chemical composition during preparation of the mold, the conventional flasking technique was followed. the lower portion of the dental flask was filled with dental type iii stone (elite model,italy)mixed according to the manufacturer instructions (i.e./p ratio is 25ml/100g); a layer of stone mix was placed on metal block to avoid trapping of air when inserting the metal block into the stone mix after coating with separating media. after stone was set, both the stone and metal patterns were coated with separating media. the upper half of the flask was then positioned on top of lower portion and filled with stone, with vibration to get rid of the trapped air. stone was allowed to harden for 60 minutes before the flask was opened. the metal patterns were invested each time when the samples were to be prepared. the flask was then opened and metal patterns were removed from the mold carefully. when using the separating medium such as tin-foil (dentaurum, pforzhein), it was adapted to the stone surface in each half of the flask, with fingers. while, in case of using cold-mold seal(11b,switzerland), and oliveoil(al-ghassuon company iraq), separating medium, (2cc) of olive oil was measured by using a disposable syringe and applied onto the stone surface in the flask, with a fine brush (no.0)(7). pink heat and cold cured acrylic resin (triplex hot ivoclar vivadent, liechtenstein) was used to fabricate the samples in the present study, following the manufacturer’s instructions of powder/ liquid ratio by volume. heat-cured acrylics were mixed (3:1), while the cold-cured acrylic was (2.5:1) by volume, and then left to reach the dough phase at room temperature (approximately 23°c). after filling the mold with the dough, the flasks were fitted and pressed together in a hydraulic bench press for (5) minutes before polymerization process. curing was carried out by placing the clamped flask (hanau engineering co.usa) in a water bath and processed by heating at 74ºc for about an hour and half. the temperature was then increased to the boiling point for 30 minutes(8), after completing the curing, the flask was allowed to cool slowly at room temperature for 30 minutes. followed by, complete cooling of the flask with tap water for 15 minutes before deflasking. the acrylic patterns were then removed from the mold. in case of curing the cold cure acrylic resin, flasks containing the acrylic resin dough were left in a bench press curing it for 2 hours at 23ºc± 5ºc (9). an acrylic bur was used to remove all flashes of acrylic followed by 120-grain size sand paper with continuous water-cooling (to prevent over heating) in order to get smooth surface (except the samples that are used for surface roughness test). polishing was accomplished using bristle brush and rag wheel with pumice(steribimplus,germany) using dental lathe polishing machine(derotor,quayledentalq.d,england), (low speed, 1500 rpm) till glossy surface was obtained, the final measurements of the samples were obtained using the vernier(rostfre;germany). tests utilized examine properties of the cured material infrared spectroscopic analysis asamples preparation: from metal disc, (4) samples of both heat and cold-cured acrylic resin (2 for each) were prepared with dimensions of (50 ± 1mm in diameter and 0.5 ± 0.1mm thickness). btest equipment and procedure: one type of infrared spectrophotometer were used (pye-unicam sp3100).this instrument is a double beam spectrophotometer operating in the region(4000-200cm-1) was found to be adequate for the observation of the structures of acrylic resins denture base(10). b a j bagh college dentistry j bagh college dentistry restorative dentistry figure ( to examine olive oil by this instrument, compressed sample of olive oil between two kbr plates (potassium bromide) in a disc holder to spread out as a thin film. this method was called mull technique used in 200cm-1). the technique. this method used different solvents in polarity to dissolve the samples of heat and cold cured acrylic resins denture against olive oil as a separating media. tolue to dissolve these samples with toluene, transfer the mixture into glass petri dishes leaving the mixture of these samples for an overnight thus allowing the solvent toluene to evapor materials as a thin film (transmittance thin film), this thin film was tested in the region of (4000 200cm-1).the same procedure was repeated one time for heat and cold base only. indentation hardness asamples from a rectangular metal pattern, 60 samples of both heat and cold base (30 for each) were prepared with the dimensions of (65mmx50mmx2.5 ± 0.03mm) length, width and depth respectively btest e brinell hardness press,leybold harris c small hardened steel or tungsten carbide ball was pressed onto the polished surface of the specimen under a known load for a definite period of time. the diameter of indentation produced was measured by means of a low with a calibrated eye the ball and the load applied vary depending upon the material being tested. in acrylic resins denture base samples, a hardened steel or tungsten carbide ball with diameter of (5mm) was pressed into the load applied of (500n) for a time of (10 second). a microscope was used for measuring the trace j bagh college dentistry restorative dentistry ure (2): infrared to examine olive oil by this instrument, compressed sample of olive oil between two kbr plates (potassium bromide) in a disc holder to spread out as a thin film. this method was called mull technique used in ). the second method called thin film technique. this method used different solvents in polarity to dissolve the samples of heat and cold cured acrylic resins denture against olive oil as a separating media. toluene solvent, was the mostly used solvent to dissolve these samples samples with toluene, transfer the mixture into glass petri dishes leaving the mixture of these samples for an overnight thus allowing the solvent toluene to evaporate leaving the remaining materials as a thin film (transmittance thin film), this thin film was tested in the region of (4000 ).the same procedure was repeated one time for heat and cold base only. indentation hardness samples preparation from a rectangular metal pattern, 60 samples of both heat and cold base (30 for each) were prepared with the dimensions of (65mmx50mmx2.5 ± 0.03mm) length, width and depth respectively equipment and brinell hardness leybold harris c small hardened steel or tungsten carbide ball was pressed onto the polished surface of the specimen under a known load for a definite period of time. the diameter of indentation produced was measured by means of a low with a calibrated eyethe ball and the load applied vary depending upon the material being tested. in acrylic resins denture base samples, a hardened steel or tungsten carbide ball with diameter of (5mm) was pressed into the load applied of (500n) for a time of (10 second). a microscope was used for measuring the trace j bagh college dentistry restorative dentistry nfrared spectrophotometer device to examine olive oil by this instrument, compressed sample of olive oil between two kbr plates (potassium bromide) in a disc holder to spread out as a thin film. this method was called mull technique used in the region of (4000 second method called thin film technique. this method used different solvents in polarity to dissolve the samples of heat and cold cured acrylic resins denture base processed against olive oil as a separating media. ne solvent, was the mostly used solvent samples (11).after dissolving all samples with toluene, transfer the mixture into glass petri dishes leaving the mixture of these samples for an overnight thus allowing the solvent ate leaving the remaining materials as a thin film (transmittance thin film), this thin film was tested in the region of (4000 ).the same procedure was repeated one time for heat and cold-cured acrylic resin denture indentation hardness test : reparation: from a rectangular metal pattern, 60 samples of both heat and cold-cured acrylic resins denture base (30 for each) were prepared with the dimensions of (65mmx50mmx2.5 ± 0.03mm) length, width and depth respectively quipment and procedure brinell hardness tester leybold harris co. british) small hardened steel or tungsten carbide ball was pressed onto the polished surface of the specimen under a known load for a definite period of time. the diameter of indentation produced was measured by means of a low-power microscope -piece. since both the size of the ball and the load applied vary depending upon the material being tested. in acrylic resins denture base samples, a hardened steel or tungsten carbide ball with diameter of (5mm) was pressed into the load applied of (500n) for a time of (10 second). a microscope was used for measuring the trace j bagh college dentistry vol. 2 pectrophotometer to examine olive oil by this instrument, compressed sample of olive oil between two kbr plates (potassium bromide) in a disc holder to spread out as a thin film. this method was called the region of (4000 second method called thin film technique. this method used different solvents in polarity to dissolve the samples of heat and cold base processed against olive oil as a separating media. ne solvent, was the mostly used solvent .after dissolving all samples with toluene, transfer the mixture into glass petri dishes leaving the mixture of these samples for an overnight thus allowing the solvent ate leaving the remaining materials as a thin film (transmittance thin film), this thin film was tested in the region of (4000 ).the same procedure was repeated one cured acrylic resin denture from a rectangular metal pattern, 60 samples cured acrylic resins denture base (30 for each) were prepared with the dimensions of (65mmx50mmx2.5 ± 0.03mm) length, width and depth respectively(12,13). rocedure: tester (hydraulic o. british)(figure3:a) small hardened steel or tungsten carbide ball was pressed onto the polished surface of the specimen under a known load for a definite period of time. the diameter of indentation produced was power microscope piece. since both the size of the ball and the load applied vary depending upon in acrylic resins denture base samples, a small hardened steel or tungsten carbide ball with diameter of (5mm) was pressed into the load applied of (500n) for a time of (10 second). a microscope was used for measuring the trace vol. 27(4), december 2015 54 pectrophotometer to examine olive oil by this instrument, compressed sample of olive oil between two kbr plates (potassium bromide) in a disc holder to spread out as a thin film. this method was called the region of (4000second method called thin film technique. this method used different solvents in polarity to dissolve the samples of heat and coldbase processed ne solvent, was the mostly used solvent .after dissolving all samples with toluene, transfer the mixture into glass petri dishes leaving the mixture of these samples for an overnight thus allowing the solvent ate leaving the remaining materials as a thin film (transmittance thin film), this thin film was tested in the region of (4000).the same procedure was repeated one cured acrylic resin denture from a rectangular metal pattern, 60 samples cured acrylic resins denture base (30 for each) were prepared with the dimensions of (65mmx50mmx2.5 ± 0.03mm) (hydraulic :a) a small hardened steel or tungsten carbide ball was pressed onto the polished surface of the specimen under a known load for a definite period of time. the diameter of indentation produced was power microscope piece. since both the size of the ball and the load applied vary depending upon small hardened steel or tungsten carbide ball with diameter of (5mm) was pressed into the load applied of (500n) for a time of (10 second). a microscope was used for measuring the trace formed on the sample surface after removal of applied load in distilled water for (1) day before hardness was calculated from areas (the same selected area) for each sample and an average of five reading was obtained by the same examiner. transverse strength test aacrylic resins denture base (30 for each) were prepared from metal pattern with dimensions of (65mmx10mmx2.5 ± 0.03mm) length, width and depth respectively b digital unit & chart drive, england) measure the transverse strength of samples in air by three points bending supplied with a central loading plunger and two supports with polished cylindrical surface, (3.2mm) and at least (10.5mm perpendicula support was in the range of 50mm ± 0.1mm, and the loading plunger was ), december 2015 formed on the sample surface after removal of applied load (figure in distilled water for (1) day before hardness was calculated from five measurements areas (the same selected area) for each sample and an average of five reading was obtained by the same examiner. figure(3): brinell brinall hardness transverse strength test samples p sixty sample acrylic resins denture base (30 for each) were prepared from metal pattern with dimensions of (65mmx10mmx2.5 ± 0.03mm) length, width and depth respectively test equipment and an instron testing digital unit & chart drive, england) measure the transverse strength of samples in air by three points bending supplied with a central loading plunger and two supports with polished cylindrical surface, (3.2mm) and at least (10.5mm perpendicular to the longitudinal center line. the distance between the centers of the support was in the range of 50mm ± 0.1mm, and the loading plunger was ), december 2015 formed on the sample surface after removal of (figure3: b). all in distilled water for (1) day before hardness was calculated from measurements were done on different areas (the same selected area) for each sample and an average of five reading was obtained by the same examiner. : brinellhardness ardness device microscope transverse strength test: reparation: samples of both heat and cold acrylic resins denture base (30 for each) were prepared from metal pattern with dimensions of (65mmx10mmx2.5 ± 0.03mm) length, width and depth respectively(14). test equipment and procedure an instron testing machine (model 112 with digital unit & chart drive, england) measure the transverse strength of samples in air by three points bending (figure supplied with a central loading plunger and two supports with polished cylindrical surface, (3.2mm) and at least (10.5mm r to the longitudinal center line. the distance between the centers of the support was in the range of 50mm ± 0.1mm, and the loading plunger was mid ), december 2015 the e formed on the sample surface after removal of all samples immersed in distilled water for (1) day before tested. the hardness was calculated from(4): were done on different areas (the same selected area) for each sample and an average of five reading was obtained by the ardness tester evice, b. low-p icroscope. of both heat and cold acrylic resins denture base (30 for each) were prepared from metal pattern with dimensions of (65mmx10mmx2.5 ± 0.03mm) length, width and . rocedure: machine (model 112 with digital unit & chart drive, england) was used to measure the transverse strength of samples in air (figure4). the device was supplied with a central loading plunger and two supports with polished cylindrical surface, (3.2mm) and at least (10.5mm) long r to the longitudinal center line. the distance between the centers of the support was in the range of 50mm ± 0.1mm, and mid-way between the a b the evaluation formed on the sample surface after removal of samples immersed tested. the were done on different areas (the same selected area) for each sample and an average of five reading was obtained by the ester: a. power of both heat and cold-cured acrylic resins denture base (30 for each) were prepared from metal pattern with dimensions of (65mmx10mmx2.5 ± 0.03mm) length, width and . machine (model 112 with was used to measure the transverse strength of samples in air . the device was supplied with a central loading plunger and two supports with polished cylindrical surface, ) long and r to the longitudinal center line. the distance between the centers of the support was in the range of 50mm ± 0.1mm, and between the a b valuation of . . j bagh college dentistry j bagh college dentistry restorative dentistry supports within 0.1mm. the tests were carried out with a constant cross head speed of (5mm/minute), and the load was measured by a compression load (5kn). the test samples were held at each end of the two supports way between the supports. all samples we statistical analyses the usual statistical methods were used in this study to analyze and assess our results, included descriptive statistics: (tables, arithmetic mean, standard deviation (s.d), minimum, maximum, graphical representation by bar inferential statistics (one way analysis of variance (anova), lsd (le test). results descriptive and inferential statistics of some mechanical properties such as (indentation hardness and cold-cured acrylic resins denture base samples which are invested in stone mold as influenced by different types of separating media (tin foil, cold mold seal, and olive oil), and a comparison between the results of them olive oil as a separating infrared spectroscopy was chemical composition changes of heat and cold cured acrylic oil as a separating media infrared spectroscopy table (1) resin denture base after processed against olive oil as a separating medium, acrylic resin d base, and olive oil. are some bands presented or has disappeared in spectra which can help in the identifications of three samples of (acrylic resin denture base after processed against olive oil as a separating media, acrylic resin denture base, a in figures by the assignment of bands for three sam it seems that, the same bonds in acrylic resin denture base, and olive oil structures. while there are many bonds has just appeared in spectrum of acrylic resin denture base and spectrum of olive oil. and also there is a single mode which appear in spectrum of olive oil and j bagh college dentistry restorative dentistry supports within 0.1mm. the tests were carried out with a constant cross head speed of /minute), and the load was measured by a compression load cell of maximum capacity of the test samples were held at each end of the supports, and the loading plunger was mid way between the supports. all samples we statistical analyses the usual statistical methods were used in this study to analyze and assess our results, included descriptive statistics: (tables, arithmetic mean, standard deviation (s.d), minimum, maximum, graphical representation by bar inferential statistics (one way analysis of variance (anova), lsd (le results descriptive and inferential statistics of some mechanical properties such as (indentation hardness and transverse strength) of heat and cured acrylic resins denture base samples which are invested in stone mold as influenced by different types of separating media (tin foil, cold mold seal, and olive oil), and a comparison between the results of them oil as a separating infrared spectroscopy was chemical composition changes of heat and cold cured acrylic resins denture base oil as a separating media infrared spectroscopy table (1)shows, the resin denture base after processed against olive oil as a separating medium, acrylic resin d base, and olive oil. the results shows that there are some bands presented or has disappeared in ra which can help in the identifications of three samples of (acrylic resin denture base after processed against olive oil as a separating media, acrylic resin denture base, a figures5 and 6. by the assignment of bands for three sam it seems that, the same bonds in acrylic resin denture base, and olive oil structures. while there are many bonds has just appeared in spectrum of acrylic resin denture base and spectrum of olive oil. and also there is a single de which appear in spectrum of olive oil and j bagh college dentistry restorative dentistry supports within 0.1mm. the tests were carried out with a constant cross head speed of /minute), and the load was measured by a cell of maximum capacity of the test samples were held at each end of the , and the loading plunger was mid way between the supports. all samples we the usual statistical methods were used in this study to analyze and assess our results, included descriptive statistics: (tables, arithmetic mean, standard deviation (s.d), minimum, maximum, graphical representation by bar inferential statistics (one way analysis of variance (anova), lsd (lest significant difference descriptive and inferential statistics of some mechanical properties such as (indentation transverse strength) of heat and cured acrylic resins denture base samples which are invested in stone mold as influenced by different types of separating media (tin foil, cold mold seal, and olive oil), and a comparison between the results of them all to evaluate the oil as a separating medium. infrared spectroscopy was used to examine the chemical composition changes of heat and cold denture base when oil as a separating media. infrared spectroscopy analysis: shows, the spectral data of acrylic resin denture base after processed against olive oil as a separating medium, acrylic resin d the results shows that there are some bands presented or has disappeared in ra which can help in the identifications of three samples of (acrylic resin denture base after processed against olive oil as a separating media, acrylic resin denture base, and olive oil by the assignment of bands for three sam it seems that, the same bonds in acrylic resin denture base, and olive oil structures. while there are many bonds has just appeared in spectrum of acrylic resin denture base and does spectrum of olive oil. and also there is a single de which appear in spectrum of olive oil and j bagh college dentistry vol. 2 supports within 0.1mm. the tests were carried out with a constant cross head speed of /minute), and the load was measured by a cell of maximum capacity of the test samples were held at each end of the , and the loading plunger was mid way between the supports. all samples we the usual statistical methods were used in this study to analyze and assess our results, included descriptive statistics: (tables, arithmetic mean, standard deviation (s.d), minimum, maximum, graphical representation by bar-chart) and inferential statistics (one way analysis of variance st significant difference descriptive and inferential statistics of some mechanical properties such as (indentation transverse strength) of heat and cured acrylic resins denture base samples which are invested in stone mold as influenced by different types of separating media (tin foil, cold mold seal, and olive oil), and a comparison all to evaluate the used to examine the chemical composition changes of heat and cold when using olive : spectral data of acrylic resin denture base after processed against olive oil as a separating medium, acrylic resin denture the results shows that there are some bands presented or has disappeared in ra which can help in the identifications of three samples of (acrylic resin denture base after processed against olive oil as a separating media, nd olive oil)as shown by the assignment of bands for three samples. it seems that, the same bonds in acrylic resin denture base, and olive oil structures. while there are many bonds has just appeared in spectrum of does not appear in spectrum of olive oil. and also there is a single de which appear in spectrum of olive oil and vol. 27(4), december 2015 55 supports within 0.1mm. the tests were carried out with a constant cross head speed of /minute), and the load was measured by a cell of maximum capacity of the test samples were held at each end of the , and the loading plunger was midway between the supports. all samples were tested after immersed for tw water. occurred. the transverse strength was calculated using the following equation the usual statistical methods were used in this study to analyze and assess our results, included descriptive statistics: (tables, arithmetic mean, standard deviation (s.d), minimum, maximum, chart) and inferential statistics (one way analysis of variance st significant difference fig descriptive and inferential statistics of some mechanical properties such as (indentation transverse strength) of heat and cured acrylic resins denture base samples which are invested in stone mold as influenced by different types of separating media (tin foil, coldmold seal, and olive oil), and a comparison all to evaluate the used to examine the chemical composition changes of heat and coldusing olive spectral data of acrylic resin denture base after processed against olive oil enture the results shows that there are some bands presented or has disappeared in ra which can help in the identifications of three samples of (acrylic resin denture base after processed against olive oil as a separating media, shown ples. it seems that, the same bonds in acrylic resin denture base, and olive oil structures. while there are many bonds has just appeared in spectrum of not appear in spectrum of olive oil. and also there is a single de which appear in spectrum of olive oil and cannot denture base, and acrylic resin denture base processed against olive oil as a separating medium which assign to the deformation and rocking modes grafted in acrylic resin denture base through the two processes heat and cold denture base indentation hardness test result standard error (se) are presented in (table2) and (figure7) for indentation hardness test. the values of indentation hardness varied according to the types of separating medium that are used. the highest mean indent obtained in heat and tin (18.45980). while the lowest mean indentation hardness value was obtained in cold resin denture base and olive oil separa (15.58040). multiple compression test, showed that there was a significant difference at (p<0.05) between different types of separating media, except for a non heat (control group) and heat separating media, cold separating media. ), december 2015 tested after immersed for tw water.the samples were deflected until fracture occurred. the transverse strength was calculated using the following equation figure (4): instron cannot be seen in spectrum of acrylic resin denture base, and acrylic resin denture base processed against olive oil as a separating medium which assign to the deformation and rocking modes, table(1). this evidence is to prove that olive oil is not grafted in acrylic resin denture base through the two processes heat and cold denture base samples indentation hardness test result mean values, standard deviation (sd) and standard error (se) are presented in (table2) and (figure7) for indentation hardness test. the values of indentation hardness varied according to the types of separating medium that are used. the highest mean indent obtained in heat and tin-foil separating media (control group) (18.45980). while the lowest mean indentation hardness value was obtained in cold resin denture base and olive oil separa (15.58040). table (3) represents one way anova by lsd multiple compression test, showed that there was a significant difference at (p<0.05) between different types of separating media, except for a non-significant difference at (p>0.05) between heat-cured acrylic resin (control group) and heat separating media, cold separating media. ), december 2015 tested after immersed for tw the samples were deflected until fracture occurred. the transverse strength was calculated using the following equation : instron testing be seen in spectrum of acrylic resin denture base, and acrylic resin denture base processed against olive oil as a separating medium which assign to the deformation and rocking table(1). nce is to prove that olive oil is not grafted in acrylic resin denture base through the two processes heat and cold samples (10,15). indentation hardness test result mean values, standard deviation (sd) and standard error (se) are presented in (table2) and (figure7) for indentation hardness test. the values of indentation hardness varied according to the types of separating medium that are used. the highest mean indentation hardness value was obtained in heat-cured acrylic resin denture base foil separating media (control group) (18.45980). while the lowest mean indentation hardness value was obtained in cold resin denture base and olive oil separa table (3) represents one way anova by lsd multiple compression test, showed that there was a significant difference at (p<0.05) between different types of separating media, except for a significant difference at (p>0.05) between cured acrylic resin-tin foil separating media (control group) and heat-cured acrylic separating media, cold-cured acrylic resin separating media. ), december 2015 the e tested after immersed for two days in distilled the samples were deflected until fracture occurred. the transverse strength was calculated using the following equation(4). esting machine be seen in spectrum of acrylic resin denture base, and acrylic resin denture base processed against olive oil as a separating medium which assign to the deformation and rocking nce is to prove that olive oil is not grafted in acrylic resin denture base through the two processes heat and cold-cured acrylic resins indentation hardness test result: mean values, standard deviation (sd) and standard error (se) are presented in (table2) and (figure7) for indentation hardness test. the values of indentation hardness varied according to the types of separating medium that are used. the ation hardness value was cured acrylic resin denture base foil separating media (control group) (18.45980). while the lowest mean indentation hardness value was obtained in cold-cured acrylic resin denture base and olive oil separating media table (3) represents one way anova by lsd multiple compression test, showed that there was a significant difference at (p<0.05) between different types of separating media, except for a significant difference at (p>0.05) between tin foil separating media cured acryliccured acrylic resin the evaluation days in distilled the samples were deflected until fracture occurred. the transverse strength was calculated be seen in spectrum of acrylic resin denture base, and acrylic resin denture base processed against olive oil as a separating medium which assign to the deformation and rocking nce is to prove that olive oil is not grafted in acrylic resin denture base through the cured acrylic resins mean values, standard deviation (sd) and standard error (se) are presented in (table2) and (figure7) for indentation hardness test. the values of indentation hardness varied according to the types of separating medium that are used. the ation hardness value was cured acrylic resin denture base foil separating media (control group) (18.45980). while the lowest mean indentation cured acrylic ting media table (3) represents one way anova by lsd multiple compression test, showed that there was a significant difference at (p<0.05) between different types of separating media, except for a significant difference at (p>0.05) between tin foil separating media -olive oil cured acrylic resintin foil valuation of j bagh college dentistry vol. 27(4), december 2015 the evaluation of restorative dentistry 56 heat-cured acrylic resin-cold mold seal separating media and heat-cured acrylic resinolive oil separating media, and cold-cured acrylic resin-tin foil separating media, cold-cured acrylic resin-cold mold seal separating media, cold-cured acrylic resin-olive oil separating media. heatcured acrylic resin-olive oil separating media and cold-cured acrylic resin –tin foil separating media, cold-cured acrylic resin-cold mold seal separating media, cold-cured acrylic resin-olive oil separating media. cold-cured acrylic resin-tin foil separating media and cold-cured acrylic resin-cold mold seal separating media and cold-cured acrylic resin-olive oil separating media. cold-cured acrylic resin-cold mold seal separating media and cold-cured acrylic resin-olive oil separating media. table (1): infrared assignment of acrylic resin denture base when processed againstolive oil as a separating medium, acrylic resin denture base, and olive oil assignment olive oil wave no.cm-1 acrylic resin wave no. cm-1 acrylic processed against olive oil wave no.cm-1 -oh(stretching) 3480(m.) 3440(m) -ch2(stretching) 3080(m.) 3040(v.s.) 3040(v.s.) -ch(stretching) 3000(v.s.) 3000(v.s.) -ch2(stretching) (ch3 stretch olive oil) 2980(v.s.) 2980(v.s.) 2980(v.s.) -ch2(stretching) 2880(s.) 2880(s.) 2885(v.s.sh.) c=o(stretching) 1750(s.) 1750(v.s.) 1750(v.s.) c=c(stretching) 1650(m.) 1680(s.sh.) =ch2(deformation) 1500-1440(v.s.) 1500-1480(v.s.) -ch3(deformation) 1470(m.) -ch3(deformation) 1460(w.sh.) -oh(deformation) 1400(s.) 1420(v.s.) -oh(deformation) 1300(v.s.) 1300(v.s.) c-o(deformation) 1210(m.sh.) 1220(v.s.) 1200(v.s.) -ch3(deformation) 1180 -ch2(deformation) 1120 =ch2 (rocking) 1080(s.) 1060(s.) -ch (wagging) 1000(w.sh.) 1000(m.sh.) =ch2 (wagging) 940(w.) 950(m.) -ch3 (rocking) 900(w.) =ch2 (rocking) 850(w.) 850(m.) c=o(deformation) 750(w.) 760(m.) 740(m.) m = medium, s = strong, w = weak, v = very shoulder j bagh college dentistry j bagh college dentistry restorative dentistry figure ( figure ( j bagh college dentistry restorative dentistry ure (5): infrared ure (6): infrared j bagh college dentistry restorative dentistry infrared spectra of resin processed against : infrared spectra of resin processed against j bagh college dentistry vol. 2 pectra of olive oil, rocessed against pectra of olive oil, rocessed against vol. 27(4), december 2015 57 il, heat-cured rocessed against olive oil as a il, cold-cured rocessed against olive oil as a ), december 2015 ured acrylic r il as a separating ured acrylic r il as a separating ), december 2015 resin, and h eparating media resin, and c eparating media ), december 2015 the e heat-cured a cold-cured a the evaluation acrylic acrylic valuation of j bagh college dentistry vol. 27(4), december 2015 the evaluation of restorative dentistry 58 table (2): mean and standard deviation, standard errors for indentation hardness of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. statistics heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o no. 10 10 10 10 10 10 mean 18.45980 16.03710 16.67270 17.28050 15.74440 15.58040 sd 2.25763 2.01808 2.76212 2.21166 2.26798 2.21176 se 0.71393 0.63817 0.87346 0.69939 0.71720 0.69942 *t.f= tin-foil , **c.m.s= cold-mold seal , ***o.o= olive oil figure (7): showsthe mean values for indentation hardness (kg/mm2) of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. table (3): anova by lsd (leastsignificant difference) for indentation hardness of heat and cold-cured acrylic resins denturebase as influenced by different types of separating media. anova=s groups heat-cured acrylic cold-cured acrylic *t.f. control ** c.m.s *** o.o t.f c.m.s o.o h ea tcu re d ac ry lic t.f. s n.s n.s s s c.m.s n.s n.s n.s n.s o.o n.s n.s n.s c ol dcu re d ac ry lic t.f n.s n.s c.m.s n.s o.o p<0.05 = s= significant, p>0.05= n.s=non significant *t.f= tin foil, **c.m.s= cold-mold seal, ***o.o= olive oil transverse strength test results: mean values, standard deviation (sd) and standard error (se) are presented in table (4) andfigure (8) for transverse strength test. the values of transverse strength varied according to the types of separating media that are used. the highest mean transverse strength value was obtained in heat-cured acrylic resin denture base and tin-foil separating media (control group) (82.194700). while the lowest mean transverse strength value was obtained in cold-cured acrylic resin denture base and cold mold seal separating media (66.638800).table (5) represents one way anova by lsd multiple compression test, 14 14.5 15 15.5 16 16.5 17 17.5 18 18.5 m ea n of in de nt at io n h ar dn es s te st (k g/ m m 2 ) heat-tin foil heat-cold mold seal heat-olive oil cold-tin foil cold-cold mold seal cold-olive oil j bagh college dentistry vol. 27(4), december 2015 the evaluation of restorative dentistry 59 showed that there was a significant difference at (p<0.05) between different types of separating media, except for a nonsignificant difference at (p>0.05) between heat-cured acrylic resin-tin foil separating media (control group) and heat-cured acrylic resinolive oil separating media. heatcured acrylic resin-cold mold seal separating media and heat-cured acrylic resin-olive oil separating media.cold-cured acrylic resin-cold mold seal separating media and cold-cured acrylic-olive oil separating media. table (4): mean and standard deviation, standard errors for transverse strength of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. statistics heat-cured acrylic cold-cured acrylic *t.f. control **c.m.s ***o.o t.f c.m.s o.o no. 10 10 10 10 10 10 mean 82.194700 79.542100 80.289000 70.528700 66.638800 67.374800 sd 1.569889 3.061168 2.701482 0.962814 1.962930 2.771643 se 0.496442 0.968026 0.854284 0.304469 0.620733 0.876471 *t.f= tin-foil , **c.m.s= cold-mold seal , ***o.o= olive oil figure (8): themean values fortransverse strength (n/mm2) of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. table (5): anova by lsdleastsignificant difference for transverse strength of heat and cold-cured acrylic resins denture base as influenced by different types of separating media. anova=s groups heat-cured acrylic cold-cured acrylic *t.f. control ** c.m.s *** o.o t.f c.m.s o.o h ea tcu re d ac ry lic t.f. s n.s s s s c.m.s n.s s s s o.o s s s c ol dcu re d ac ry lic t.f s s c.m.s n.s o.o p<0.05 = s= significant, p>0.05=n.s= non significant t.f= tin foil, c.m.s= cold –mold seal, o.o=olive oil discussion among other factors coefficients, separating medium must be used, due to its effect on the mechanical properties of the processed acrylic denture base materials. in the present study, olive oil is used as a separating medium in the process of curing both heat and cold-cured acrylic resins denture base. infra-red spectroscopy analysis: from the infrared spectroscopic analysis of the different materials used in the present study, including (acrylic resins denture base processed 0 10 20 30 40 50 60 70 80 90 m ea ns o f t ra ns ve rs e s tr en gt h te st (n /m m 2) heat-tin foil heat-cold mold seal heat-olive oil cold-tin foil cold-cold mold seal cold-olive oil j bagh college dentistry vol. 27(4), december 2015 the evaluation of restorative dentistry 60 against olive oil as a separating medium, acrylic resins denture base only, and olive oil), showed no differences in the spectrum of the composition of both heat and cold-cured acrylic resins denture base after processing in stone mold lined with olive oil separating media with no changes in the bonds, no additional bonds of olive oil in the processed acrylic resins denture base are detected, that means no reaction between olive oil and acrylic resin denture base (heat and cold), no grafting of olive oil in heat and cold-cured acrylic resins denture base was found after processing(15). indentation hardness: high values of hardness was obtained in heat – cured acrylic resin processed against tin foil separating media when compared with those samples processed against cold – mold seal and olive oil separating media, similar results was obtained in cold – cured acrylic resin samples, this could be related to that, the hardness of dry specimens are greater than those for wet specimens these results agreed with parr and rueggebery(16). on the other hand, high mean values of hardness was found in heat – cured acrylic resin samples when compared with those samples of coldcured acrylic resin, similar results were obtained by many studies(17-19)when they concluded that, in general, heat-cured material is significantly harder than cold-cured material under all conditions. this could be related to the higher amount of residual monomer presented in cold-cured type, which adversely affects the indentation hardness. and olive oil separating media show a comparable result concerning indentation hardness. there isno statistically significant difference between samples processed against cold-mold seal separating media and those samples processed against olive oil separating media. while there was a significant difference between samples processed against tin foil and cold-mold seal separating media. this could be related to high water sorption which leads to greatest decrease in indentation hardness. this explanation is in agreement with woelfel et, al.,(20).their findings were confirmed by stafford and smith(21),when they reported that water sorption adversely affects the hardness resistance of pmma. also it may be related to porosity, which may decrease the hardness resistance. transverse strength: the result of the present study showed a high values of transverse strength in all samples of heat-cured acrylic resin denture base with reduced values in cold-cured acrylic resin denture base samples are estimated, similar results are observed bymany researches(81,22-24)when they concluded that the strength in transverse bending of self-cured acrylic resin is inferior to that of heat-cured materials and recorded approximately 80% of the heat-cured material. this may be related to residual monomer in cold-cured materials, which is affected adversely with transverse strength and olive oil as a separating medium showed comparable result regarding transverse strength. furthermore, there is no statistically significant difference between samples processed against cold-mold seal separating media and those samples processed against olive oil separating media. while there was a significant difference between samples processed against tin foil and cold-mold seal separating media for both dental resins. these results agreed withfairhurst and ryge(25)when they concluded that, the use of tin foil substitute as a mold liner for processing selfcuring and heat curing denture base resins results in a slight, less strength product than when using tin foil separating media. this may be related to high water sorption of the acrylic denture base material lined tin foil substitute which may be cause of lowering the transverse strength value. also, it may be related to porosity if it reaches the surface; the transverse strength will be lowered. this explanation agreed withdavenport (26).whilein other studies(27,28) found no-significant difference between the transverse strength of resin processed in tin foil and that of resin processed in tin foil substitute. from the present study the following conclusions can be withdrawn: 1. tin foil is the most ideal type of separating medium for lining molds during the process of both heat and cold-cured acrylic resins followed by olive oil and cold-mold seal separating medium regarding indentation hardness and transverse strength. 2. infrared spectroscopic analysis shows no changes in the composition of the processed both heat and cold-cured acrylic resins denture base against olive oil separating medium. 3. comparable results were found between coldmold seal and olive oil separating medium regarding (indentation hardness and transverse strength) of processed acrylic resins denture base. 4. finally, from the results obtained, it can be concluded that olive oil forms a satisfactory material for being used as a separating medium of process acrylic resins denture base. j bagh college dentistry vol. 27(4), december 2015 the evaluation of restorative dentistry 61 references 1. glossary of prosthodontic terms. the academy of prosthodontics, 2005. 2. anderson jn. applied dental materials 4th ed. london blackwell scientific publications; 1972 3. rahan ao, heartwell cm. textbook of complete dentures. 1993 4. craig rg, powers jm. restorative dental materials. 11th ed. st. louis: mosby co.; 2002. 5. naval us. dental prosthodontic technician, flasking and tin-foiling. 2nd ed. maryland for publication by bureau of naval personnel. 1950. p.143-57, 6. phillips rw. skinner’s science of dental materials. 7th ed. philadelphia: saunders co.; 1973. 7. al-musawi rm. evaluation of glycerin as a separating medium for processing acrylic denture base materials (comparative study). a master thesis, college of health and medical technology, 2005. 8. ada. american dental standers institute/american dental association specification no.12 for denture base polymer chicago; council on dental materials and devices; 1999. 9. walter jd, gloysher. the properties of self-curing denture bases. br dent j 1972; 132: 223. 10. colthup nb, daly lh, wiberley se. introduction to infrared and ramoxn spectroscopy. a subsidiary of harcourt brace joranovich publishers, 1975. 11. muhammad mr, mohsen f. spectro chemical acta 1990; 46(1): 33-42. 12. al-khafaji mt. evaluation of some physical and mechanical properties of refabricated self-cured acrylic from used self-cured materials. a master thesis, college of dentistry, university of baghdad, 1998. 13. al-neami zj. the effect of different water temperatures duringpolymerization on some physical and mechanical properties of self-cure acrylic resin material’’. a master thesis, college of health and medical technology, 2005. 14. ada. american dental association specification no.12 for denture base polymers. chicago: council on dental materials and devices, 1975. 15. muhammad mr. j iraqi chemical soc 1988; 13(1): 241-54. 16. parr gr, rueggebery fa. in vitro hardness, water sorption and resin solubility of laboratory processed and auto-polymerized long-term resilient denture liners overone year of water storage. j prosth dent 2002; 88(2): 139-44 17. vonfraunhofer ja, schatlamponcy c. the surface characteristics of denture base polymer. j dent 1971; 3(3): 106-9 18. beech dr. molecular weight distribution of denture base acrylic. j dent 1975; 3: 19–24. 19. jaggar rg. effect of curing cycle on some properties of pmma denture base materials. j oral rehabil 1978; 5: 151-7. 20. woelfel bj, paffenbrger gc, sweeney wt. some physical properties of organic denture base materials. j am dent assoc 1963: 67(4): 489-504. 21. stafford gd, smith dc. some studies of the properties of denture base polymers. br dent j 1968; 15: 337 22. leong a, grant aa. the transverse strength of repairs in polymethel methacrylate. aust dent j 1971; 16: 182-5. 23. ruter le, sevendson sa. flexural properties of denture base polymers. j prosthet dent 1980; 43: 95104. 24. ray n. dental materials science. int, university dental school and hospital, ireland: 1988. 38-48. 25. fairhurst cw, ryge g. effect of tin-foil substitutes on the strength of denture base resin. j prosthet dent 1955; 5(4): 508-13. 26. davenport jc. the denture surface. br dent j 1972; 133:101-5. 27. ferguson gw, paffenbarger gc, schoonever ic. deficiencies of tin-foil substitutes in the processing of acrylic resin. j am dent assoc 1949; 38(5): 57386. 28. peyton fa, delgado vp. some comparisons of selfcuring and heat-curing denture resin. j prosth dent 1953; 3: 332-8. doaa f.docx j bagh college dentistry vol. 27(3), september 2015 orthodontic considerations pedodontics, orthodontics and preventive dentistry130 orthodontic considerations of functional occlusion in class і normal occlusion doaa b. al-nassar, b.d.s. (1) hadeel a. al-hashimi, b.d.s., m.sc. (2) abstract background: the therapeutic goal of orthodontic treatment is to establish ideal occlusion which includes both static and functional aspects. the objective of this study was to clarify functional occlusal treatment goals by analyzing functional occlusion in subjects with established normal occlusion and identify the differences between canine protected occlusion and group function occlusion. materials and methods: the sample consisted of 62 subjects with normal occlusion and with an age range of (18-25 years).functional occlusal contacts during lateral excursion were identified on a fully adjustable articulator, and then the samples were classified according to: 1) type of functional occlusion: a) canine protected occlusion group (canine protected occlusion on both working sides). b) group function occlusion group (group function occlusion on both working sides). c) mixed functional occlusion group (canine protected occlusion on one side and group function occlusion on the other side ). 2) working side contact into: canine protected occlusion (62 sides) and group function occlusion (62 sides). then different variables were analyzed. results: results revealed that vertical canine overlap, position of maxillary canine and 1st molar mesiobuccal cusp tip to the center of opposing embrasure/groove, and arch form analysis had significant difference between groups. adding to that, some of the maxillary and mandibular teeth were significantly differed between groups in regard to crown angulation and inclination. conclusions: it was concluded that the vertical canine overlap, position of maxillary canine and 1st molar mesiobuccal cusp tip to the center of the opposing embrasure/groove, arch form harmony were important functional aspects of orthodontic treatment goals. key words: orthodontic considerations, functional occlusion, normal occlusion. (j bagh coll dentistry 2015; 27(3):130139). introduction the therapeutic goal of orthodontic treatment is to create an occlusion that has a close resemblance to established normal occlusal features. this orthodontic picture of "ideal occlusion" is largely the result of work by angle (1900) and andrews (1972). in assessing the quality of completed orthodontic treatment, considerable emphasis is placed on the static occlusal relationship with less emphasis on the importance of the functional occlusion (1). furthermore; orthodontic classifications are related more to anatomic and esthetic standards than to neuromuscular harmony and functional stability (2). however, the optimal functional occlusion type has not been so easily identified (3). as widely known, the specialist needs to be expertise in all aspects of functional occlusion because a very close relationship has been found between orthodontic treatment and all components of the masticatory system. the angle’s classification is a good way to start with, but no way offers adequate parameters for defining treatment goals. many occlusions pres (1)master student. department of orthodontics. college of dentistry, university of baghdad. (2)professor. department of orthodontics. college of dentistry, university of baghdad. senting solid class i relationship may present several pathological aspects (4). the gentle lateral and protrusive shift is not only necessary from the standpoint of mandibular movement, but also necessary from the orthodontist's point of view in terms of posttreatment stability of the tooth positions (5). the achievement of the ideal functional occlusion provided a satisfactory stability after orthodontic treatment. thus, the establishment of the static and functional criteria leads to the success of the orthodontic treatment by minimizing orthodontic relapse and prevents the appearance of occlusal pathologies (6). after reviewing the related studies and articles, no previous study was found to identify the occlusal features that related to each type of functional occlusion. normal occlusion is of great importance since it is the aim of orthodontic treatment. so this present study formulated to highlight on determinants of functional occlusion as an orthodontic treatment goals. materials and method sample the sample of the present study consisted of 62 subjects (20 males and 42 females), which j bagh j bagh college dentistry pedodontics, orthodontics and preventive dentistry were selected from the students of college of dentistry/baghdad university criteria were considered in sample 1. iraqi arab adult subjects with age from 18 years. 2. clinically skeletal class i. 3. no clear asymmetries in the dental arches and face and no history of previous facial trauma assessed by visual examination. 4. they have full set of permanent teeth in both jaws "excluding the 3 5. they have bilateral class i molar and canine relation with normal and well 6. no previous occlusal adjustments and/or teeth attrition. 7. no restorations or carious lesions that extended to cusps inclines or incisal edges and no artificial prosthesis. 8. no pathologic periodontal problems according to the gingival index. 9. no tmj problem according to research diagnostic criteria and clinical exa method for each participant informed consent was obtained before the start of examination. occlusion of each subject was assessed by intra oral examination and the f was identified by clinical inspec left side and then confirmed from the articulator. the subjects included in the sample were distributed into three main groups 1. canine protected occlusion subjects) occlusion during lateral mandibular movement, contacts occur only between upper and lower canine on the working side. 2. group function occlusion both sides are group function occlusion during lateral mandibular movement, more than contact 3. mixed functional occlusion subjects) occlusion and the ot occlusion. after completion of clinical examination pairs of dental casts (2 upper and 2 lower) produced other for measurements. dental casts for measurement the parallelism of the upper and lower cast bases to the occlusal plane the relation of the maxillary arch to the temporomandibular joint (hinge axis) was college dentistry pedodontics, orthodontics and preventive dentistry were selected from the students of college of dentistry/baghdad university criteria were considered in sample iraqi arab adult subjects with age from 18 years. clinically skeletal class i. no clear asymmetries in the dental arches and face and no history of previous facial trauma assessed by visual examination. they have full set of permanent teeth in both jaws "excluding the 3 they have bilateral class i molar and canine relationships, class i incisor classification with normal over well-aligned arches no previous occlusal adjustments and/or teeth attrition. no restorations or carious lesions that extended to cusps inclines or incisal edges and no artificial prosthesis. no pathologic periodontal problems according to the gingival index. no tmj problem according to research diagnostic criteria and clinical exa for each participant informed consent was obtained before the start of examination. occlusion of each subject was assessed by intra oral examination and the f was identified by clinical inspec left side and then confirmed from the articulator. the subjects included in the sample were distributed into three main groups canine protected occlusion subjects): both sides are canine protected occlusion during lateral mandibular movement, contacts occur only between upper and lower canine on the working side. group function occlusion both sides are group function occlusion during lateral mandibular movement, more than one tooth on the working side a contact. mixed functional occlusion subjects): one side is canine protected occlusion and the ot occlusion. after completion of clinical examination pairs of dental casts (2 upper and 2 lower) produced; one for moun other for measurements. dental casts for measurements were prepared in a way to ensure the parallelism of the upper and lower cast bases to the occlusal plane (figure 1, a and b) the relation of the maxillary arch to the temporomandibular joint (hinge axis) was college dentistry pedodontics, orthodontics and preventive dentistry were selected from the students of college of dentistry/baghdad university. the following criteria were considered in sample iraqi arab adult subjects with age from 18 clinically skeletal class i. no clear asymmetries in the dental arches and face and no history of previous facial trauma assessed by visual examination. they have full set of permanent teeth in both jaws "excluding the 3rd molar". they have bilateral class i molar and canine ships, class i incisor classification -jet and overbite (2 aligned arches no previous occlusal adjustments and/or teeth no restorations or carious lesions that extended to cusps inclines or incisal edges and no artificial prosthesis. no pathologic periodontal problems according to the gingival index. no tmj problem according to research diagnostic criteria and clinical exa for each participant informed consent was obtained before the start of examination. occlusion of each subject was assessed by intra oral examination and the functional occlusion was identified by clinical inspection left side and then confirmed from the articulator. the subjects included in the sample were distributed into three main groups: canine protected occlusion : both sides are canine protected occlusion during lateral mandibular movement, contacts occur only between upper and lower canine on the working side. group function occlusion'gfo' both sides are group function occlusion during lateral mandibular movement, more one tooth on the working side a mixed functional occlusion : one side is canine protected occlusion and the other is group function after completion of clinical examination pairs of dental casts (2 upper and 2 lower) ; one for mounting in articulator and the other for measurements. dental casts for were prepared in a way to ensure the parallelism of the upper and lower cast bases (figure 1, a and b) the relation of the maxillary arch to the temporomandibular joint (hinge axis) was college dentistry vol. 27(3), september 2015 pedodontics, orthodontics and preventive dentistry were selected from the students of college of the following criteria were considered in sample selection: iraqi arab adult subjects with age from 18no clear asymmetries in the dental arches and face and no history of previous facial trauma assessed by visual examination. they have full set of permanent teeth in both molar". they have bilateral class i molar and canine ships, class i incisor classification jet and overbite (2-4 mm) no previous occlusal adjustments and/or teeth no restorations or carious lesions that extended to cusps inclines or incisal edges no pathologic periodontal problems according to the gingival index. no tmj problem according to research diagnostic criteria and clinical examination. for each participant informed consent was obtained before the start of examination. static occlusion of each subject was assessed by intra unctional occlusion tion for right and left side and then confirmed from the articulator. the subjects included in the sample were : canine protected occlusion'cpo'(22 : both sides are canine protected occlusion during lateral mandibular movement, contacts occur only between upper and lower canine on the working side. 'gfo' (22 subjects) both sides are group function occlusion during lateral mandibular movement, more one tooth on the working side are in mixed functional occlusion 'mfo' (18 : one side is canine protected her is group function after completion of clinical examination, two pairs of dental casts (2 upper and 2 lower) were ting in articulator and the other for measurements. dental casts for were prepared in a way to ensure the parallelism of the upper and lower cast bases (figure 1, a and b). the relation of the maxillary arch to the temporomandibular joint (hinge axis) was 7(3), september 2015 pedodontics, orthodontics and preventive dentistry131 were selected from the students of college of the following -25 no clear asymmetries in the dental arches and face and no history of previous facial they have full set of permanent teeth in both they have bilateral class i molar and canine ships, class i incisor classification 4 mm) no previous occlusal adjustments and/or teeth no restorations or carious lesions that extended to cusps inclines or incisal edges no pathologic periodontal problems no tmj problem according to research mination. for each participant informed consent was static occlusion of each subject was assessed by intraunctional occlusion for right and left side and then confirmed from the articulator. the subjects included in the sample were (22 : both sides are canine protected occlusion during lateral mandibular movement, contacts occur only between upper and lower canine on the working side. (22 subjects): both sides are group function occlusion during lateral mandibular movement, more re in (18 : one side is canine protected her is group function two were ting in articulator and the other for measurements. dental casts for were prepared in a way to ensure the parallelism of the upper and lower cast bases the relation of the maxillary arch to the temporomandibular joint (hinge axis) was transferred to fully adjustable articulator (stratos 300, ivoclar vivadent, austria) by the mean of universal transfer vivadent, austria) figure registration: (a) frontal view; (b) lateral modeling wax (of 4 sheets thickness) softened in a hot water at 55 on the bite fork of uts3d. bow to the articulator was done according to the ''personalized model transfer with the uts3d'' instruction (instruction supplied with the articulator), previously prepared for mounting. during mounting centric fixation lock to keep the models in centric occlu fixation lock was opened, and the adjustable incisal plate was mounted, at this time the articulator was ready (figure 3 mounted models in centric position; (b) articulator ready for eccentric movement. then, working side and non contacts were recorded by manipulating the articulator to the lat 7(3), september 2015 131 transferred to fully adjustable articulator (stratos 300, ivoclar vivadent, austria) by the mean of universal transfer vivadent, austria) figure 1: preparation of to be parallel to the occlusal plane: (a) figure 2: transfer bow during bite registration: (a) frontal view; (b) lateral the subject was asked to bite on modeling wax (of 4 sheets thickness) softened in a hot water at 55 on the bite fork of uts3d. bow to the articulator was done according to the ''personalized model transfer with the uts3d'' instruction (instruction supplied with the articulator), using the models which were previously prepared for mounting. during mounting, the articulator was held in centric by centric fixation lock to keep the models in centric occlusion (figure fixation lock was opened, and the adjustable incisal plate was mounted, at this time the articulator was ready (figure 3, b). figure 3: articulator adjustment: (a) mounted models in centric position; (b) articulator ready for eccentric movement. then, working side and non contacts were recorded by manipulating the articulator to the lat 7(3), september 2015 orthodontic transferred to fully adjustable articulator (stratos 300, ivoclar vivadent, austria) by the mean of universal transfer bow system (uts3d, ivoclar vivadent, austria) (figure 2, 1: preparation of to be parallel to the occlusal plane: (a) upper; (b) lower. 2: transfer bow during bite registration: (a) frontal view; (b) lateral view. subject was asked to bite on modeling wax (of 4 sheets thickness) softened in a hot water at 55 on the bite fork of uts3d. bow to the articulator was done according to the ''personalized model transfer with the uts3d'' instruction (instruction supplied with the using the models which were previously prepared for mounting. during the articulator was held in centric by centric fixation lock to keep the models in centric (figure 3, a). then, the centric fixation lock was opened, and the adjustable incisal plate was mounted, at this time the articulator was ready for eccentric movement 3: articulator adjustment: (a) mounted models in centric position; (b) articulator ready for eccentric movement. then, working side and non contacts were recorded by manipulating the articulator to the lateral cusp to cusp position. orthodontic transferred to fully adjustable articulator (stratos 300, ivoclar vivadent, austria) by the mean of bow system (uts3d, ivoclar (figure 2, a and b). 1: preparation of dental casts bases to be parallel to the occlusal plane: (a) upper; (b) lower. 2: transfer bow during bite registration: (a) frontal view; (b) lateral view. subject was asked to bite on a modeling wax (of 4 sheets thickness) which softened in a hot water at 55ºc (7) and was p on the bite fork of uts3d. transfer of the face bow to the articulator was done according to the ''personalized model transfer with the uts3d'' instruction (instruction supplied with the using the models which were previously prepared for mounting. during the articulator was held in centric by centric fixation lock to keep the models in centric , a). then, the centric fixation lock was opened, and the adjustable incisal plate was mounted, at this time the for eccentric movement 3: articulator adjustment: (a) mounted models in centric position; (b) articulator ready for eccentric movement. then, working side and non-working side contacts were recorded by manipulating the eral cusp to cusp position. orthodontic considerations transferred to fully adjustable articulator (stratos300, ivoclar vivadent, austria) by the mean of bow system (uts3d, ivoclar dental casts bases to be parallel to the occlusal plane: (a) 2: transfer bow during bite registration: (a) frontal view; (b) lateral a piece of which was was placed transfer of the face bow to the articulator was done according to the ''personalized model transfer with the uts3d'' instruction (instruction supplied with the using the models which were previously prepared for mounting. during the articulator was held in centric by centric fixation lock to keep the models in centric , a). then, the centric fixation lock was opened, and the adjustable incisal plate was mounted, at this time the for eccentric movement 3: articulator adjustment: (a) mounted models in centric position; (b) the articulator ready for eccentric movement. working side contacts were recorded by manipulating the eral cusp to cusp position. considerations j bagh j bagh college dentistry pedodontics, orthodontics and preventive dentistry the groups were identified according to the type of functional occlusion (fi figure 4: working side contact: (a) canine protected occlusion; (b) group function on the model prepared for measurements; the facial axis of the clinical crown and its midpoint (facial axis point), was marked with a pencil each crown of all teeth except third molars. the facial axis of the clinical crown represents the most prominent portion of the central lobe on the facial surface of each crown; for molars, it represents the buccal groove that separa two large fa marked as the midpoint of the fa clinical crown figure 5 the facial axis of the clinical the reference line from which crown angulation and inclination were measured. angulation and inclination were measured by manual measuring device (figure crown angulation is the angle formed by the facial axis of the clinical crown (viewed from facial perspective) with a perpendicular line to the occlusal plane (represented by protractor) (figure 7 crown inclination is the angle formed between the line perpendicular to the occlusal plane (represented by 90º of the protractor) and line that is parallel and tangent to facial axis of clinical crown at facial axis point. to get an accurate result, the devise was supplied adjustable light source and laser pointer to see clearly when the devise pointer touches the faci point of each crown college dentistry pedodontics, orthodontics and preventive dentistry groups were identified according to the type f functional occlusion (fi 4: working side contact: (a) canine protected occlusion; (b) group function occlusion. on the model prepared for measurements; the facial axis of the clinical crown and its midpoint (facial axis point), was marked with a pencil each crown of all teeth except third molars. the facial axis of the clinical crown represents the most prominent portion of the central lobe on the facial surface of each crown; for molars, it represents the buccal groove that separa two large facial cusps. marked as the midpoint of the fa clinical crown (8-10)(figure 5, a and b) 5: facial axis: (a) anterior teeth; (b) posterior teeth. the facial axis of the clinical reference line from which crown angulation and inclination were measured. angulation and inclination were measured by manual measuring device (figure crown angulation is the angle formed by the facial axis of the clinical crown (viewed from l perspective) with a perpendicular line to the occlusal plane (represented by protractor) (figure 7). crown inclination is the angle formed between the line perpendicular to the occlusal plane (represented by 90º of the protractor) and t is parallel and tangent to facial axis of clinical crown at facial axis point. to get an accurate result, the devise was supplied adjustable light source and laser pointer to see clearly when the devise pointer touches the faci point of each crown (figure 8 college dentistry pedodontics, orthodontics and preventive dentistry groups were identified according to the type f functional occlusion (figure 4, a and b). 4: working side contact: (a) canine protected occlusion; (b) group function occlusion. on the model prepared for measurements; the facial axis of the clinical crown and its midpoint (facial axis point), was marked with a pencil each crown of all teeth except third molars. the facial axis of the clinical crown represents the most prominent portion of the central lobe on the facial surface of each crown; for molars, it represents the buccal groove that separa cial cusps. the facial axis point was marked as the midpoint of the fac (figure 5, a and b) : facial axis: (a) anterior teeth; (b) posterior teeth. the facial axis of the clinical crown served as reference line from which crown angulation and inclination were measured. angulation and inclination were measured by manual measuring device (figure 6 crown angulation is the angle formed by the facial axis of the clinical crown (viewed from l perspective) with a perpendicular line to the occlusal plane (represented by ). crown inclination is the angle formed between the line perpendicular to the occlusal plane (represented by 90º of the protractor) and t is parallel and tangent to facial axis of clinical crown at facial axis point. to get an accurate result, the devise was supplied adjustable light source and laser pointer to see clearly when the devise pointer touches the faci (figure 8, a, b and c) college dentistry vol. 27(3), september 2015 pedodontics, orthodontics and preventive dentistry groups were identified according to the type , a and b). 4: working side contact: (a) canine protected occlusion; (b) group function on the model prepared for measurements; the facial axis of the clinical crown and its midpoint (facial axis point), was marked with a pencil each crown of all teeth except third molars. the facial axis of the clinical crown represents the most prominent portion of the central lobe on the facial surface of each crown; for molars, it represents the buccal groove that separates the the facial axis point was cial axis of the (figure 5, a and b). : facial axis: (a) anterior teeth; (b) crown served as reference line from which crown angulation and inclination were measured. crown angulation and inclination were measured by 6). crown angulation is the angle formed by the facial axis of the clinical crown (viewed from l perspective) with a perpendicular line to the occlusal plane (represented by 90º of the crown inclination is the angle formed between the line perpendicular to the occlusal plane (represented by 90º of the protractor) and t is parallel and tangent to facial axis of clinical crown at facial axis point. to get an accurate result, the devise was supplied with adjustable light source and laser pointer to see clearly when the devise pointer touches the faci , a, b and c). 7(3), september 2015 pedodontics, orthodontics and preventive dentistry132 groups were identified according to the type 4: working side contact: (a) canine protected occlusion; (b) group function on the model prepared for measurements; the facial axis of the clinical crown and its midpoint (facial axis point), was marked with a pencil on each crown of all teeth except third molars. the facial axis of the clinical crown represents the most prominent portion of the central lobe on the facial surface of each crown; for molars, it tes the the facial axis point was ial axis of the : facial axis: (a) anterior teeth; (b) crown served as reference line from which crown angulation crown angulation and inclination were measured by crown angulation is the angle formed by the facial axis of the clinical crown (viewed from l perspective) with a perpendicular line to 90º of the crown inclination is the angle formed between the line perpendicular to the occlusal plane (represented by 90º of the protractor) and t is parallel and tangent to facial axis of clinical crown at facial axis point. to get an with adjustable light source and laser pointer to see clearly when the devise pointer touches the facial measure crown angulation and inclination. inclination: (a) the measuring supplied with light measuring the distance between the cusp tip of the mandibular canine to a point correspond to cusp tip of the maxillar marked on the mandibular canine when the maxillary canine overlap the mandibular one in centric occlusion. pattern was determined for maxillary teeth from 7(3), september 2015 132 figure 6: schematic drawing of manual measuring device with protractor to measure crown angulation and inclination. figure figure inclination: (a) the measuring supplied with light (b) light source; (c) laser pointer. vertical canine overlap was determined by measuring the distance between the cusp tip of the mandibular canine to a point correspond to cusp tip of the maxillar marked on the mandibular canine when the maxillary canine overlap the mandibular one in centric occlusion. buccal cusp to embrasure/groove occlusal pattern was determined for maxillary teeth from 7(3), september 2015 orthodontic 6: schematic drawing of manual measuring device with protractor to measure crown angulation and inclination. figure 7: measurement of crown angulation. figure 8: measurement of crown inclination: (a) the measuring supplied with light source and laser pointer; (b) light source; (c) laser pointer. vertical canine overlap was determined by measuring the distance between the cusp tip of the mandibular canine to a point correspond to cusp tip of the maxillary canine which was marked on the mandibular canine when the maxillary canine overlap the mandibular one in centric occlusion. buccal cusp to embrasure/groove occlusal pattern was determined for maxillary teeth from orthodontic 6: schematic drawing of manual measuring device with protractor to measure crown angulation and inclination. 7: measurement of crown angulation. : measurement of crown inclination: (a) the measuring device was source and laser pointer; (b) light source; (c) laser pointer. vertical canine overlap was determined by measuring the distance between the cusp tip of the mandibular canine to a point correspond to y canine which was marked on the mandibular canine when the maxillary canine overlap the mandibular one in buccal cusp to embrasure/groove occlusal pattern was determined for maxillary teeth from orthodontic considerations 6: schematic drawing of manual measuring device with protractor to measure crown angulation and inclination. 7: measurement of crown : measurement of crown device was source and laser pointer; (b) light source; (c) laser pointer. vertical canine overlap was determined by measuring the distance between the cusp tip of the mandibular canine to a point correspond to y canine which was marked on the mandibular canine when the maxillary canine overlap the mandibular one in buccal cusp to embrasure/groove occlusal pattern was determined for maxillary teeth from considerations j bagh college dentistry vol. 27(3), september 2015 orthodontic considerations pedodontics, orthodontics and preventive dentistry133 canine to 2nd premolar by measuring the anteroposterior distance (in millimeter) from cusp tip to the center of the opposing embrasure. for the maxillary 1st and 2nd molars it was determined by measuring the antero-posterior distance (in millimeter) from the mesio-buccal cusp tip to the opposing mandibular 1st and 2nd molars buccal grooves. for arch form analysis, dental casts was placed on the glass window of the flat bed computer scanner with a plastic ruler (11).then, the transverse and sagittal measurements were taken using different components of special performed software (autodesk design review 2010). maxillary and mandibular dental arches forms were categorized as narrow, mid, or wide according to their dimensions. the dental arch form was determined by standardization, six dental cast’s measurements (three sagittal measurements and three transverse measurements) were utilized to calculate three independent ratios (12)which are:  canine vertical distance/inter-canine distance.  molar vertical distance/inter-first molar distance.  total arch length/inter-second molar distance. the standardize number was calculated for each of three ratios for each subject by the excel program. the mean of these standardized numbers was calculated for each subject who gave the base for classification as follows: ∩ narrow arch form (n): the three sagittal/transverse ratios are positive (greater than the mean), the mean of standardized numbers (> +1). ∩ mid arch form (m): none of the ratios significantly deviated from the average, the mean of standardized numbers (between +1 and -1). ∩ wide arch form (w): the three sagittal/transverse ratios are negative (lesser than the mean), the mean of standardized numbers (< -1). after determination of each dental arch form (maxillary and mandibular) harmony or coordination between maxillary and mandibular dental arches for each subject was analyzed. score (0) was given when both dental arches were of the same form, while score (1) was given if there was disharmony between maxillary and mandibular dental arches forms. results for inferential statistics, two types of comparisons were used to assess the result of the present study. some of them were used to compare between two working side groups 'cpo' and 'gfo', while the other comparisons were made among three groups 'cpo', 'gfo', and 'mfo'. by using independent t-test only mandibular central and lateral incisors and 2ndmolar showed a statistically significant difference in crown angulation (table 1), while 2nd premolar and 2ndmolar in the maxillary arch, central incisor and 1stmolar in the mandibular arch showed a statistically significant difference in crown inclination between the two groups (table 2). table (3) showed that cpo group had higher mean value of vertical canine overlap than gfo group according to independent t-test. the obtained data for buccal cusp to embrasure/groove occlusal pattern was divided into 6 intervals as shown in table (4) and to assess the result likelihood ratio was used, which showed that there were highly significant differences between groups for maxillary canine and 1st molar. table (5) showed the result of arch form analysis, contingency coefficient (c.c) was used to show if there is a significant association in arch form analysis scores among three studied groups. results showed that there was a significant association among groups (table 6). furthermore, odds ratio used to compare between each pair of groups, results showed that there was a significant difference between cpo and gfo and a non-significant difference between (cpo/mfo) and (gfo/mfo) (table 7). discussion previous studies reported that class і canine and molar occlusal relationships associated with different functional occlusion patterns (13-15). these patterns may be considered normal or not in relation to other parts of the masticatory system and border mandibular movement. in the 1970s, orthodontic gnathologists argued that orthodontic patients’ functional occlusion should be finished to cpo and mentioned that patients would predictably finish with balancing contacts and eventual tmd when orthodontists ignore patients’ functional occlusion and rely on handheld models rather than articulators (16,17). canine is the most appropriate tooth to guide mandibular lateral excursion due to crown morphology, good crown/root ratio and is capable of tolerating high occlusal force, and the canine root has a greater surface area than adjacent teeth which providing greater proprioception (18). canines have been considered as the first line of control to keep the mandible functioning more vertically, so cpo reduces the chances of tmd. the canines were the most j bagh college dentistry vol. 27(3), september 2015 orthodontic considerations pedodontics, orthodontics and preventive dentistry134 likely candidates for mandibular guidance function as they prevent the lateral enmeshment of working side posterior teeth due to their strategic location from fulcrum and stressbreaking capabilities (19). moreover, the forces directed out of the long axis of the posterior teeth in gfo associated with the presence of bacterial biofilm, can cause pathologies of occlusal origin (20,21). it has been observed that when canine protection is taken away, muscles stay active leading to clenching, grinding of teeth, abfraction, and gum recession (19). selection of sample in this study based on class і normal occlusion, because the identification of the type of functional occlusion associated with normal static occlusion is of particular interest for orthodontists, since they direct their patients' treatment plan to achieve this type of static occlusion. in this study the age of the subjects was between 18-25 years, because the majority of facial growth is usually complete by 16-17 years of age (22). the late mandibular growth which occurs in late teens as well as earlier may influence the position of dentition relative to maxilla and mandible (23). so the changes which occurring during occlusal development could influence the occlusal contact pattern (15). also, the subjects who were more than 25 years of age were excluded in the present study, due to more mutilation and attrition of dentition in those subjects (24,25). examining functional occlusion on articulated casts valid and reproducible method for occlusal diagnosis (1). it was established that fullyadjustable articulators have a large range of adjustability in three dimensions (18,26,27),so recording tooth contact by using a fully adjustable articulator with a correct transfer technique provide more accurate and reproducible results. the cpo group showed higher mesial angulation for the mandibular second molar and higher distal angulation for the mandibular central and lateral incisors compared to gfo group. while, non-significant differences were found between the groups for all maxillary teeth (table 1). this may be due to the fact that the mandible is the moving (functional) jaw, so it is more affected by other parts of the masticatory system. misch and abbas (28) considered maxilla as a force distribution unit and mandible as a force absorption unit. in the mandible only central, lateral incisors and second molar had significantly different angulations between groups; this may be related to the chewing kinematics and bio-functional anatomy of occlusion. the question here; is the chewing kinematic cause such a difference, or this difference in crown angulation results in different chewing patterns between groups? the effect of occlusal factors on the function of the masticatory system is controversial topic for years (3,29). some investigators hypothesized that occlusion and facial form contribute to functional variation (30-32), on the contrary, others (33) suggested that functional parameters and muscle activity patterns are significant factors contributing to occlusal schemes. green et al. (34) mentioned that in the second year of life when the deciduous dentition reaches full occlusion, the characteristics of the shape of the masticatory cycle are finalized. furthermore, throckmorton et al. (35) added that the masticatory cycle do not vary much throughout life. it is possible that subjects with more vertical chewing patterns would best fit a canine protected functional occlusion scheme and those with horizontal chewing patterns would prefer more lateral freedom that would be consistent with group function (3). in conclusion there is a cause and effect relationship between occlusal parameter and type of chewing cycle or kinematic. the more horizontal chewing cycle in gfo may be a causative factor for the difference in crown angulations between groups in regard to mandibular anterior segment. this may be explained by that, the horizontal chewing cycle is associated with more horizontal (lateral) forces that transmitted from canine to mandibular anterior segment. thus these teeth are in angulation more toward midline when compared with the same teeth of cpo group in which chewing cycle is more vertical. the vertical chewing kinematic in cpo and the direction of masseter muscle fibers, may result in more mesial angulation of the mandibular 2ndmolar to be parallel with this muscle fibers (2nd molar is near the masseter muscle). inclination of the posterior teeth may be of great importance in functional occlusion because of their direct relationship with lateral mandibular movement. the results of this study showed that there is a general increase in the palatal inclination for maxillary posterior teeth, and lingual inclination of mandibular 2nd premolar, 1st molar, and 2ndmolar in gfo group when compared with the same teeth in cpo group. only maxillary 2nd premolar, 2nd molar and mandibular 1stmolar, showed statistical significant differences between groups (table 2). these results may be explained by that; in cpo, the vertical chewing pattern helps to prevent the repeated lateral forces, and provide disclusion of the posterior teeth early during lateral mandibular j bagh college dentistry vol. 27(3), september 2015 orthodontic considerations pedodontics, orthodontics and preventive dentistry135 movement. in addition to lee (36)who mentioned that the more vertical guidance by the canine helps to prevent the upper and lower posterior teeth from colliding as the mandible moves toward centric position, we can point that the horizontal chewing pattern in gfo may leads to the lateral enmeshment of working side posterior teeth, make the disclusion or opening of the working side posterior teeth more difficult and shorten the chewing stroke leading to repeated lateral forces on these teeth. based on what previously mentioned, the repeated lateral forces resulted from collision of mandibular posterior teeth with the opposing maxillary teeth during mandibular laterotrusive movement would result in more lingual inclination of mandibular posterior teeth in gfo group compared with the same teeth in cpo group. but only the mandibular 1stmolar showed a significant difference between groups which can be explained by the more palatal inclination of the opposing maxillary 1stmolar compared to the adjacent teeth, so during laterotrusive mandibular movement, the palatal incline of the buccal cusp of the maxillary 1stmolar clashes with the buccal cusp of the mandibular one resulting in more lingual inclination of the mandibular 1stmolar. when the mandible returned back to intercuspal position at the end of its lateral movement, the lingual inclines of the buccal cusps of the mandibular posterior teeth contact with the buccal inclines of the palatal cusps of the opposing maxillary teeth, which may be also attributed to the more palatal inclination of the opposing teeth. since the mandibular 1st molar had more lingual inclination when compared with the adjacent teeth, making the cusps of this tooth to be shorter or lower when compared with other teeth. so it has less effect on the opposing tooth during this movement. that’s why only maxillary 2nd premolar and 2ndmolar have a significant increase in their palatal inclination in gfo. mandibular central incisor shows less labial inclination in cpo than in gfo group. this result may be explained by that such inclination may increase the vertical overlap of the teeth as a functional mechanism to keep mandibular guidance more anteriorly as anterior teeth have a mechanical advantage over posterior teeth because they are farther from the fulcrum (tmj). this inclination of mandibular central incisors is more relevant to mutually protected occlusion. the vertical canine overlap showed a highly significant difference between cpo and gfo groups which is a logical result. during lateral excursion, cusp tip of the mandibular canine moves along the palatal surface of the maxillary canine, so the more vertical overlap, the longer and more vertical chewing stroke, resulting in no posterior contact and canine protected occlusion. maxillary canine cusp tip to embrasure occlusal pattern showed a highly significant difference between cpo and gfo groups. the position of maxillary canine cusp tip near the center of the opposing embrasure may result in a longer and more vertically directed chewing stroke. maxillary 1stmolar mesiobuccal cusp to opposing groove occlusal pattern showed a highly significant difference between cpo and gfo groups. as shown in table (4), the maxillary 1stmolar mesiobuccal cusp tip tends to position more anteriorly to the opposing groove in gfo group. this may be explained as this position will result in longer path of the mandibular 1st molar mesiobuccal cusp along the palatal incline of mesiobuccal cusp of the maxillary 1stmolar and this longer path prevent early disclusion of this tooth during lateral mandibular movement and vice versa in cpo group. significant difference between cpo and gfo group was observed in relation to the arch form analysis. the majority of cpo group was with harmonious forms between maxillary and mandibular dental arches. on the other hand, 22.58% and 25.80% from the total sample had score (0) in gfo and mfo groups respectively. this means that factors other than the arch form may be implicated in these results. however, the probability of occurring gfo is high when there is disharmony in arch form between maxillary and mandibular dental arches, while coordination between maxillary and mandibular dental arches forms does not mean that it will necessarily end with cpo. so, other factors collectively with arch form harmony should be taken in consideration in regard to functional occlusion. the finding of this study may be explained as follow: in case when the mandibular arch was of narrow form and the maxillary arch was of mid form, during lateral movement, mandibular posterior teeth contact maxillary posterior teeth before canine, so the canine will be away from guiding mandibular movement and disclusion of posterior teeth resulting in gfo. on the other hand, when the mandibular arch was of mid form and the maxillary arch was of narrow form, contact during lateral excursion occur firstly in canine, but due to the wider mandibular arch, the maxillary canine unable to withstand a full range of mandibular movement, so that the canine become out of contact earlier than other teeth posterior to it leaving the guidance function for the posterior teeth ending with a gfo. j bagh college dentistry vol. 27(3), september 2015 orthodontic considerations pedodontics, orthodontics and preventive dentistry136 as a conclusion; in order to achieve canine protected occlusion when functional occlusion is considered in addition to the normal static occlusion as an orthodontic treatment goals, some significant points must be obtained collectively: 1. sufficient vertical canine overlap which is the most important determinant factor for functional occlusion pattern 2. position of canine cusp tip at the center of opposing embrasure or within one millimeter anterior to it. 3. position of the mesiobuccal cusp tip of the maxillary 1st molar at the center of the opposing 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orthop 1999; 115: 305-13. الخالصھ الھدف من ھذه .نشاء اإلطباق المثالي والذي یشمل كال الجانبین الساكن والوظیفيإسنان ھي األھداف العالجیھ لتقویم األن إ:خلفیة الموضوع بین اإلطباق الوظیفي لدى أشخاص ممن لدیھم إطباق مثالي وتعریف الفروقاتالوظیفیھ من خالل تحلیل الدراسھ ھو لتوضیح األھداف العالجیھ .إطباق وظیفة المجموعھواإلطباق المحمي بالناب م تحدیدت.سنة) 2518(ومن الفئة العمریة التي تتراوح أعمارھم بین طبیعي إطباق لدیھم شخصًاممن٦٢منھتألفتعینةالدراس : الموادوالطرق :حسب العینھللتعدیل التام، وبعد ذلك تم تصنیف الجانبیھ على مفصلھقابلھ خالل حركة الفك األطباقیھالتماسات :نوع االطباق الوظیفي الى ) ١ .)طباق المحمي بالناب على كال جانبي العملاإل(طباق المحمي بالناب اإلمجموعة ) أ .)العملاطباق وظیفة المجموعھ على جانبي (مجموعة اطباق وظیفة المجموعھ ) ب ).طباق وظیفة المجموعھ على الجانب اآلخرإطباق المحمي بالناب على احدى جوانب العمل واإل(االطباق المختلط ) ج ثم تم تحلیل ).جانب ٦٢( طباق وظیفة المجموعھ إو) جانب ٦٢( طباق المحمي بالناب اإل: في جانب العمل الواحد الى االطباقیھالتماسات ) ٢ . ةالمتغیرات المختلف / ول في الفكالعلوي بالنسبھ للفتحھ األوسط الخدي للطاحن األلقد اظھرت النتائج ان التداخل العمودي للناب، موقع قمة الناب والنتوء :النتائج سنان العلویھ األ ضافھ الى إن بعضباإل. المختلفة حصائیھ بین المجامیعإذات داللھ خدود المقابل، وتحلیل شكل قوس األسنانكان لھا فروقاتاأل .سناناألوالسفلیھ اختلفت بشكل معنوي من حیث تزوي ومیل تیجان االخدود /بالنسبھ للفتحھول في الفك العلوي األوسط الخدي للطاحن األالتداخل العمودي للناب وموقع قمة الناب والنتوء خلص الى إن:األستنتاج .ھ وظیفیھ في اھداف العالج التقویميسنان لھا أھمیاألاقواس شكل الى تجانس باالضافھالمقابل table 1: descriptive statistics for crown angulation (in degree) of maxillary and mandibular teeth in cpo and gfo groups with comparison between groups arch teeth groups 'df=122' min. max. mean sd se t-test p-value m ax ill ar y central incisor cpo 0 8 3.63 1.96 0.25 -0.128 0.899 ns gfo 0 10 3.67 2.05 0.26 lateral incisor cpo 0 12 5.88 2.58 0.33 -0.603 0.548 ns gfo 0 14 6.17 2.82 0.36 canine cpo -1 15 5.37 3.22 0.41 0.064 0.949 ns gfo -1 15 5.34 3.26 0.41 1st premolar cpo 0 9 3.73 2.68 0.34 0.13 0.897 ns gfo -2 11 3.66 3.16 0.4 2nd premolar cpo 0 15 5.12 3.16 0.4 0.759 0.449 ns gfo -1 14 4.65 3.65 0.46 1st molar cpo 0 12 5.65 2.88 0.37 1.467 0.145 ns gfo -3 14 4.81 3.46 0.44 2nd molar cpo -9 8 -0.09 4.08 0.52 0.006 0.995 ns gfo -8 10 -0.10 3.67 0.47 m an di bu la r central incisor cpo -5 2 -1.50 1.6 0.2 -2.274 0.025 s gfo -7 5 -0.71 2.19 0.28 lateral incisor cpo -7 3.5 -1.67 2.35 0.3 -2.269 0.025 s gfo -7 5 -0.62 2.8 0.36 canine cpo -7.5 8 0.61 3.38 0.43 -1.647 0.102 ns gfo -8 8 1.64 3.63 0.46 1st premolar cpo -6 7.5 1.46 3.17 0.4 -1.213 0.228 ns gfo -8 11 2.23 3.79 0.48 2nd premolar cpo -6 9 2.86 3.24 0.41 -0.426 0.671 ns gfo -6 10 3.13 3.66 0.47 1st molar cpo -5 10 3.47 2.72 0.35 0.22 0.826 ns gfo -1 9 3.37 2.37 0.3 2nd molar cpo -1 14 5.32 3.1 0.39 2.6 0.010 s gfo -7 10 3.84 3.24 0.41 j bagh college dentistry vol. 27(3), september 2015 orthodontic considerations pedodontics, orthodontics and preventive dentistry138 table 2: descriptive statistics for crown inclination (in degree) of maxillary and mandibular teeth in cpo and gfo groups with comparison between groups arch teeth groups 'df=122' min. max. mean sd se t-test p-value m ax ill ar y central incisor cpo -1 16 7.48 4.32 0.55 0.415 0.679 ns gfo -7 15 7.14 4.76 0.60 lateral incisor cpo -7 18 5.34 5.53 0.70 -1 0.319 ns gfo -6 18 6.33 5.54 0.70 canine cpo -11 19 -1.23 5.97 0.76 -0.802 0.424 ns gfo -11 13 -0.39 5.73 0.73 1st premolar cpo -14 12 -1.46 5.19 0.66 1.261 0.21 ns gfo -14 10 -2.66 5.40 0.69 2nd premolar cpo -17.5 8.5 -1.90 5.44 0.69 2.439 0.016 s gfo -18 7 -4.36 5.78 0.73 1st molar cpo -18 6 -5.79 5.40 0.69 1.664 0.0.99 ns gfo -19 8 -7.41 5.45 0.69 2nd molar cpo -19 10 -2.38 5.46 0.69 2.023 0.045 s gfo -17.5 16 -4.34 5.35 0.68 m an di bu la r central incisor cpo -9 12 3.01 6.18 0.79 -2.255 0.026 s gfo -8.5 14 5.4 5.57 0.71 lateral incisor cpo -14 11 0.28 6.4 0.81 -1.098 0.274 ns gfo -13 11 1.43 5.21 0.66 canine cpo -22 3 -5.46 5.56 0.71 -0.538 0.561 ns gfo -16.5 7 -4.89 5.35 0.68 1st premolar cpo -22 5 -9.67 5.75 0.73 0.27 0.788 ns gfo -21 3 -9.95 5.46 0.69 2nd premolar cpo -32 4 -14.5 6.54 0.83 1.351 0.179 ns gfo -33 0 -16.04 6.12 0.78 1st molar cpo -35 19 -23.15 7.92 1.01 2.158 0.033 s gfo -35 -15 -25.63 4.41 0.56 2nd molar cpo -38 -12 -26.97 5.85 0.74 0.375 0.708 ns gfo -38 24 -27.46 8.52 1.08 table 3: descriptive statistics for vertical canine overlap (mm) in cpo and gfo groups with comparison between groups. variable groups 'df=122' extreme values mean sd se t-test p-value ve rt ic al c an in e ov er la p cpo min. 2.06 3.203 0.626 0.080 4.048 0.000 hs max. 4.55 gfo min. 1.46 2.730 0.675 0.086 max. 3.99 table 4: intervals (mm) of buccal cusp to opposing embrasure/groove occlusal pattern in cpo and gfo with comparison between groups tooth groups intervals comparison -2~-1 -1~0 0 0~1 1~2 2~2.5 likelihood ratio df p-value canine cpo freq. 0 0 31 13 14 4 14.406 4 0.006 (hs) % 0 0 50 20.97 22.58 6.45 gfo freq. 0 1 13 17 28 3 % 0 1.61 20.97 27.42 45.16 4.84 1st premolar cpo freq. 0 5 30 13 12 2 4.247 4 0.375 (ns) % 0 8.06 48.39 20.97 19.35 3.23 gfo freq. 0 3 21 19 15 4 % 0 4.84 33.87 30.65 24.19 6.45 2nd premolar cpo freq. 1 1 18 15 23 4 8.843 5 0.115 (ns) % 1.61 1.61 29.03 24.19 37.10 6.45 gfo freq. 0 0 8 18 28 8 j bagh college dentistry vol. 27(3), september 2015 orthodontic considerations pedodontics, orthodontics and preventive dentistry139 % 0 0 12.90 29.03 45.16 12.90 1st molar cpo freq. 2 11 42 5 2 0 18.462 5 0.002 (hs) % 3.23 17.74 67.74 8.06 3.23 0 gfo freq. 2 1 38 11 9 1 % 3.23 1.61 61.29 17.74 14.52 1.61 2nd molar cpo freq. 2 4 42 7 7 0 5.410 5 0.368 (ns) % 3.23 6.45 67.74 11.29 11.29 0 gfo freq. 2 1 39 8 10 2 % 3.23 1.61 62.90 12.90 16.13 3.23 table 5: arch form for maxillary and mandibular arches in cpo, gfo, and mfo groups. groups score arch form c p o 0 no.=20 18 (m) 1 (w) 1 (n) 1 no.=2 1 'w' maxillary arch 'm' mandibular arch 1 'm' maxillary arch 'n' mandibular arch g f o 0 no.=14 12 (m) 2 (w) 1 no.=8 4 'm' maxillary arch 'n' mandibular arch 4 'n' maxillary arch 'm' mandibular arch m f o 0 no.=16 12 (m) 3 (n) 1 (w) 1 no.=2 'm' maxillary arch 'w' mandibular arch table 6: arch form analysis in cpo, gfo, and mfo groups with comparison among groups. groups freq. and percentages arch form analysis total c.c group difference 0 1 pvalue cpo freq. 20 2 22 0.305 0.042 (s) % groups 90.90% 9.10% 100% % total 32.25% 3.22% 35.47% gfo freq. 14 8 22 % groups 63.60% 36.40% 100% %total 22.58% 12.90% 35.48% mfo freq. 16 2 18 % groups 88.90% 11.10% 100% % total 25.80% 3.22% 29.02% table 7: arch form analysis (comparison between each couple of groups by odds ratio). groups odds ratio p-value cpo/gfo 5.714 p=0.031 (s) cpo/mo 1.250 p=0.832 (ns) mfo/gfo 4.566 p=0.067 (ns) jamal f.doc j bagh college dentistry vol. 27(3), september 2015 study of salivary oral diagnosis 55 study of salivary iga concentrations, salivary flow rate in patients with β –thalassemia major in missan governorate jamal m. diwan, b.d.s., h.d.d. (1) zaheda j. mohammad, b.d.s, m.sc., ph.d. (2) abstract background: beta-thalassemia major is the most common monogenic known disorder in the middle east, characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. this study aimed to evaluate salivary flow rate and salivary iga in β-thalassemia major patients. since many oral and systemic conditions manifest themselves as changes in the flow and composition of saliva the dental practitioner is advised to remain up-to-date with this issue. materials and methods: the study samples consist of (60) subjects, patients group composed of (30) patients with β – thalassemia major, age rang (5-23) years and (30) healthy locking subject of both sexes as control group, with age range from (5-25) years. results: most patients were in the first and second decade of life (90%) this indicate a reduced life expectancy in those patients, laboratory investigations for salivary iga concentrations revealed a significant increase in means of this marker in compare with control group and this difference is statistically significant, (p= 0.05) at p value ≤ 0.05.regarding the salivary flow rate there was a statistically significant decrease in mean of salivary flow rate in patients group as compared with control group (p= 0.013). conclusions: beta-thalassemia major affects salivary flow rate and siga concentration. keywords: thalassemia, salivary iga, salivary flow rate. (j bagh coll dentistry 2015; 27(3):55-57). introduction thalassemia is a serious inherited hematological disorders characterized by a deficient synthesis of either the α or β chains of globin in the hemoglobin molecule resulting in reduced hb in red blood cells (rbc), its inherited as autosomal recessive gene disorder (1). the homozygous type that is known as βthalassemia major or cooley’s anemia is the most common monogenic disorder in the mediterranean basin, the middle east, the south pacific and asia (2). world health organization (who) data revealed that about 7% of the world’s population is a carrier of a hemoglobin disorder and about 300,000-500,000 children are born each year with the severe homozygous states of these diseases (3). the affected persons have various degrees of anemia (low red blood cell values) and enlarged liver and spleen, depending on the type of genetic defects in red blood cells’ hemoglobin production (4). secretory immunoglobulin a (siga) is the dominant immunoglobulin in external secretions that bathe mucosal surfaces (respiratory, intestinal, and reproductive), where it acts as a key component of the immune system’s “first line of defense” against microbial invasion (5), salivary iga antibodies could help oral immunity by preventing microbial adherence, neutralizing enzymes, toxins and viruses; or by acting in synergy with other factors such as lysozyme and lactoferrin (6). (1)m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. salivary fluid is an exocrine secretion consisting of approximately 99% water, containing a variety of electrolytes (sodium, potassium, calcium, chloride, magnesium, bicarbonate, phosphate) and proteins, represented by enzymes, immunoglobulins and other antimicrobial factors, mucosal glycoproteins, traces of albumin and some polypeptides and oligopeptides of importance to oral health. there are also glucose and nitrogenous products, such as urea and ammonia (7). saliva represents an increasingly useful auxiliary means of diagnosis. sialometry and sialochemistry are used to diagnose systemic illnesses, monitoring general health, and as an indicator of risk for diseases creating a close relation between oral and systemic health (8). materials and methods sixty subject were participated in this study, they were divided into two groups, patients group composed of 30 patients with major β– thalassemia on regular blood transfution, age rang (5-23), and 30 healthy looking subject of both sexes as a control group, age rang (5-25).they were in missan thalassemia and hematological diseases center in missan province, one of the south iraqi governorates, this center is the only center for management of thalassemic patients, in which approximately 300 patients were registered. patient with interferon hepatitis b and c virus infections and spleenoctomy were excluded. data was collected using a special formula constructed by the researcher for demographic data including (age, gender, occupation, marital status and j bagh college dentistry vol. 27(3), september 2015 study of salivary oral diagnosis 56 residency), medical and surgical history, salivary flow rate and laboratory findings. whole nonstimulated saliva was collected, measured, centrifuged, and 0.5 ml of supernatant is preserved in cryovials at -20 c° and analyzed later by enzyme linked immunosorbent assay (elisa). results most patients were in the first and second decade of life (90%), 20 (60%) were males and 10 (40%) were females with an age rage 5-23 years (table 1). salivary flow rate shows a statistically significant difference in mean of salivary flow rate in patients group as compared with control group (table 2). laboratory investigations for salivary concentration of siga revealed a significant difference in mean of this marker in beta thalassemia major patients as compared with control group (table 3). discussion the present study showed that most of the patients with βthalassemia major were in the first and second decades of life, which indicates a lack of life expectancy, this finding is consistent with a results found by many researchers, in which patients with βthalassemia major live an average of 17 years and usually die by 30 years of age (9), in the present study; males constitute a higher percentage (twice the females) similar predominance were reported by other previous studies (10,11), this finding may be a gender bias due to cultural values in which male have greater care or males are more registered in these centers, many researchers found that, thalassemia affects men and women equally and occurs in approximately 4.4 of every 10,000 live births (12,13). the present study demonstrated that a significant increase in salivary iga concentration in patient group than control group this may be due to decrease salivary flow rate in patients group which in return increase siga concentration this in agree with eliasson et al., this study reported that the salivary secretion rate may inversely influence the iga concentration in saliva. table 1: the distribution of study groups according to age and gender variables patients (n=30) control (n=30) statistical test and p. value age mean± sd (year) 12±5.6 11.4±4.9 t = 1.3 p = 0.66 ns* range 5 – 23 525 gender male no. (%) 20 (66.7) 18 (60.0) fet=0.28 p = 0.78 ns* female no. (%) 10 (33.3) 12 (40.0) table 2: comparison of mean salivary flow rates between study groups salivary flow rate (ml/min) patient (n=30) controls (n=30) mean ± sd (ml/min) 0.30 ± 0.15 0.33 ± 0.085 range 0.1 0.7 0.2 0.6 ttest = 0.97, degree of freedom= 58, p=0.013 s= significant at p≤ 0.05 table 3: mean and standard deviation of siga in saliva with ttest in study groups. salivary iga (µg / ml) patient (n=30) controls (n=30) mean ± sd 390.6 ±92.7 263.9 ±46.8 range 189-534 169 – 369 ttest = 7.7, degree of freedom = 58, p=0.05 *s at p≤ 0.05 references 1. dama sb, dama lb. prevalence of orofacial complications in thalassemic patients from solapur, maharashtra state, india. dav inter j sci 2014; 1(1): 100-6. 2. salehi mr, farhud dd, tohidast tj, sahebjamee m. prevalence of orofacial complications in iranian patients with β-thalassemia major. iran j public health 2007; 36: 43-6. j bagh college dentistry vol. 27(3), september 2015 study of salivary oral diagnosis 57 3. who/march of dime. report of a joint meeting, 2006; may 5-15. 4. cappellini m-d, cohen a, eleftheriou a, piga a, porter j, taher a. guidelines for the clinical management of thalassaemia. 2nd revised ed. november 2008. thalassaemia international federation, cyprus. 5. woof jm, kerr ma. the function of immunoglobulin a in immunity. j pathol 2007; 208(2): 270-82. 6. weemaes c, klasen i, geِrtz j, beldhuis-valkis m, olafsson o, haraldsson a. development of immunoglobulin a in infancy and childhood. scand j immunol 2003; 58(6): 642-8. 7. tabak la. a revolution in biomedical assessment: the development of salivary diagnostics. j dent educ 2001; 65: 1335-9. 8. humphrey sp, williamson rt. a review of saliva: normal composition, flow, and function. j prosthet dent 2001; 85:162-9. 9. modell b, khan m, darlison m. survival in β -thalassaemia major in the uk: data from the uk thalassaemia register. lancet 2000; 355(9220): 2051-2. 10. norri m. oror-facial, salivary and radiographic changes in major thalassemic patients in mosul. a master thesis, department of oral medicine, college of dentistry, university of baghdad, 2004. 11. khan mh, khan f, ayub t, shah h. frequency of complications in β–thalassemia major. biomedica 2007; 23: 31-3. 12. rund d, rachmilewitz e. β-thalassemia. new engl j med 2005; 353:1135–46. 13. borgna-pignatti c, rugolotto s, de stefano p, et al. survival and complications in patients with thalassemia major treated with transfusion and deferoxamine. haematologica 2004; 89:1187-93 noor f.doc j bagh college dentistry vol. 28(2), june 2016 an evaluation the effect pedodontics, orthodontics and preventive dentistry 134 an evaluation the effect of alcohol presence in mouth washes on force degradation of different configurations of elastomeric chains noor n. abbass abdullah, b.d.s. (1) nihdal h. ghaib, b.d.s., m.sc. (2) abstract background: elastomeric chains are one of the most commonly used force delivery systems. they have the ability to exert a continuous force, convenience of use, compatibility to oral environment and cost effectiveness but one of the inherited disadvantages is force degradation. materials and methods: this in vitro study was designed to evaluate the effect of alcohol presence in mouthwashes on force decay of different configurations of clear elastomeric chains from (ortho technology company) which are: closed , short and long under the effect of time at (initial, 1, 2, 3 and 4 weeks) intervals with exposure to different chemical solutions. a total (540) modules of elastomeric chains of three different types (long, short and closed) transparent in color, with an initial length (19mm) and about 50% extension (29mm) were used for the study. these elastomeric chains divided in to four groups and exposed to different chemical solutions (listerine original alcoholic mouthwash, listerine zero alcohol mouth wash, ethanol 26.9%, distilled water) twice daily for 60 seconds according to manufacturer instructions to measure the amount of force degradation in different time intervals. these elastomeric chains were incubated in covered glass containers at 37c˚ for the entire testing period. results: statistical analysis showed that there was a highly significant difference in the mean percentage of force decay (p≤ 0.001). for all chemical solutions the highest percentage of force decay occurs in listerine original alcoholic mouth wash. also in all chemical solutions closed elastomeric chains has the least percentage of force decay. while closed configuration have the highest percentage of force decay. conclusion: we can conclude that alcoholic mouth wash(listerine original) causes increase force degradation of all types of elastomeric chains while alcohol free mouth wash (listerine zero) causes less force degradation of all types of elastomeric chains. also closed configuration elastomeric chains have the least percentage of force decay than other configurations. key words: evaluate the effect of alcohol presence in mouth washes on force degradation of different. (j bagh coll dentistry 2016; 28(2):134-138). introduction use of an orthodontic appliance demands that the wearer take special care because the presence of this device in the oral cavity leads to greater accumulation of bacterial plaque around brackets and bands (1,2). considering that deficient oral hygiene generally is a reason why it is difficult to achieve successful orthodontic treatment, it is necessary for the dentist to implement an individualized model of a program of preventive education for each patient (3). in individuals who cannot or are unable to perform good oral hygiene, in addition to mechanical control, it is important to implement chemical plaque control by using mouth washes (4). elastic chains are widely used in combination with fixed orthodontic appliances to close or to prevent the opening of spaces. their main advantages include the following: ease of use, low price, reduced potential for intraoral trauma, minimal need for patient compliance, and wide array of colors or transparency. (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. their disadvantages can be seen in inconsistency of force levels over time, absorption of fluids leading to discoloration, and impairment of oral hygiene 3various factors have been shown to impact the amount of force decay observed with elastomeric chains. one example of a controllable factor is the use of mouth rinses, which are commonly recommended to dental patients by orthodontists and other oral healthcare providers to assist in maintaining oral health during treatment. many of these mouth rinses contain alcohol at various concentrations ranging from 0.5%–26.9%, with the majority around 14%. ethanol is included in many mouth rinses as a dissolvent and carrier for the active ingredients. is it possible that our recommendations may be contributing to the force decay of our materials and subsequently to less efficient orthodontic treatment? (5). therefore, the objectives of this study were twofold. first, to evaluate the effect of alcohol presence in mouthwashes on percentage force decay of elastomeric chain products, second to evaluate the percentage force decay of three different configurations of elastomeric chain products from the same company. j bagh college dentistry vol. 28(2), june 2016 an evaluation the effect pedodontics, orthodontics and preventive dentistry 135 materials and methods a prospective laboratory study was completed to evaluate the effect of alcohol presence in mouth washes on force degradation of elastomeric chain. a total (540) modules of elastic chains with different configurations (closed, short, long) transparent in color, having an expiry date at (2016), were selected from ortho technology company, usa, were tested for load relaxation. the specimens used in the study having an initial length (19mm) and about 50% extension (29mm) and placed on custom made acrylic boards. these elastomeric chains divided in to four groups and exposed to different chemical solutions (listerine original alcoholic mouthwash, listerine zero alcohol free mouth wash, ethanol 26.9%, distilled water) twice daily for 60 seconds according to manufacturer instructions to measure the amount of force decay in different time intervals. these elastomeric chains were incubated in covered glass containers at 37c˚ for the entire testing period. all samples of elastomeric chains (except those tested for initial force) were placed under cyclic exposure between distilled water and chemical solutions during the test period of the study. six force measurements were made at the following time intervals: initial (0), one day, 1, 2, 3 and 4 weeks. force measurements were obtained with a digital force tester. during force measurement, the acrylic boards were securely bound to a bench top using a vice clamp. measurements were made by leaving one end of the elastomeric chain secured on the pin and fixing the other to the force tester (fig.1), allowing for the measurement of the tensile force. measurement readings were taken with the elastomeric chain stretched to the same 29 mm length that the acrylic board pins had previously maintained them. all chains were handled and measured in the same manner at the same vertical and horizontal distance on the acrylic board to ensure consistent measurements (5). figure 1: force measurements of elastomeric chains used in the study statistical analysis data collected analyzed by using relevant soft ware statistical package of social science (spss, chicago, 111). these data of the delivered forces for all specimens were averaged, and the results were analyzed with the following statistics: 1. descriptive statistics: mean of load, mean of the percentage of force decay and their standard deviation. 2. inferential statistics: (anovatest and lsd test). results different configurations of elastomeric chains had different mean load and percentage of force decay over time (tables 1, 2). the statistical analysis indicated that there was a significant interaction between elastomeric chain configuration and chemical solution (p= 0.000); therefore, the effect of configurations on percentage force decay over time must be examined separately for each chemical solution over different time intervals (table 3). j bagh college dentistry vol. 28(2), june 2016 an evaluation the effect pedodontics, orthodontics and preventive dentistry 136 table 1: means and standard deviations of load values of different elastomeric chain types treated with different chemical solutions. duration elastics types d.w. (i) listerine zero (ii) listerine original (iii) ethanol 26.9% (iv) mean s.d. mean s.d. mean s.d. mean s.d. initial n=30 closed 365.018 0.03 365.018 0.03 365.018 0.03 365.018 0.03 short 341.027 0.03 341.027 0.03 341.027 0.03 341.027 0.03 long 315.016 0.02 315.016 0.02 315.016 0.02 315.016 0.02 1 day n=30 closed 186.095 1.25 186.095 1.25 186.095 1.25 186.095 1.25 short 166.602 1.06 166.602 1.06 166.602 1.06 166.602 1.06 long 147.777 1.70 147.777 1.70 147.777 1.70 147.777 1.70 1 week n=120 closed 181.262 1.18 180.021 0.99 173.708 0.53 176.76 0.72 short 159.356 1.09 158.816 1.58 155.421 0.93 157.82 1.55 long 140.371 1.19 138.583 0.99 137.612 0.84 139.78 0.83 2 weeks n=120 closed 162.266 1.58 161.489 0.47 156.265 0.87 159.93 0.94 short 144.357 1.10 143.208 0.36 137.145 0.84 139.91 0.92 long 126.460 0.97 124.826 0.69 117.461 1.02 121.60 0.84 3 weeks n=120 closed 155.056 1.10 153.420 0.72 149.606 0.98 149.74 1.03 short 135.837 0.86 132.761 0.86 129.524 0.50 129.89 1.05 long 117.882 0.86 115.177 1.04 110.549 0.97 111.53 1.71 4 weeks n=120 closed 154.415 0.55 152.973 0.55 147.501 0.51 149.30 1.07 short 135.103 0.02 131.681 0.64 127.652 0.67 128.91 0.53 long 116.784 1.26 113.168 0.47 109.649 0.76 110.30 0.78 table 2: means and standard deviations of the percentage of force decay of different types of elastomeric chains immersed with different media duration elastics type d.w. (i) listerine zero (ii) listerine original (iii) ethanol 26.9% (iv) mean s.d. mean s.d. mean s.d. mean s.d. zero closed 0 0 0 0 short 0 0 0 0 long 0 0 0 0 1 day n=30 closed 49.017 0.34 49.017 0.34 49.017 0.34 49.017 0.34 short 51.147 0.31 51.147 0.31 51.147 0.31 51.147 0.31 long 53.089 0.54 53.089 0.54 53.089 0.54 53.089 0.54 1 week n=120 closed 50.342 0.32 50.682 0.27 52.411 0.14 51.575 0.19 short 53.272 0.32 53.430 0.47 54.426 0.27 53.721 0.45 long 55.440 0.38 56.008 0.31 56.316 0.27 55.627 0.26 2 weeks n=120 closed 55.546 0.43 55.759 0.13 57.190 0.24 56.187 0.25 short 57.670 0.32 58.007 0.10 59.785 0.25 58.974 0.27 long 59.856 0.31 60.375 0.22 62.713 0.32 61.399 0.27 3 weeks n=120 closed 57.521 0.30 57.969 0.20 59.014 0.27 58.978 0.28 short 60.168 0.25 61.070 0.25 62.019 0.14 61.913 0.30 long 62.579 0.27 63.438 0.33 64.907 0.31 64.597 0.54 4 weeks n=120 closed 57.697 0.15 58.092 0.15 59.591 0.14 59.099 0.29 short 60.384 0.004 61.387 0.19 62.568 0.19 62.200 0.16 long 62.928 0.40 64.076 0.15 65.193 0.24 64.986 0.25 j bagh college dentistry vol. 28(2), june 2016 an evaluation the effect pedodontics, orthodontics and preventive dentistry 137 table 3: effect of immersion time on force degradation of different types of elastomeric chains in different chemical testing solutions media elastics types anova test lsd test f-test p-value 1 day1 week 1 day 2 weeks 1 day 3 weeks 1 day 4 weeks 1week 2 weeks 1week 3 weeks 1week 4 weeks 2 weeks 3 weeks 2 weeks 4 weeks 3 weeks 4 weeks d.w. (i) closed 1622.589 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.227 short 2391.620 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.080 long 1259.196 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.051 listerine zero (ii) closed 3331.326 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.241 short 2488.377 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.019 long 1997.562 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 listerine original (iii) closed 3710.628 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 short 4354.968 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 long 2408.264 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.075 ethanol 26.9% (iv) closed 2677.508 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.331 short 2523.051 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.046 long 1829.292 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.033 discussion effect of different configurations examination of table (2) reveals that closed elastomeric chains has the least percentage of force decay in all chemical solutions and all time intervals followed by short elastomeric chains and the highest percentage of force decay occur in long configurations in all chemical solutions. difference in the degree of the initial mean loads was noted among the studied brands (table 1). regarding the modular geometry or design, the trend which was presented that elastomeric chains with short and long configuration had initial mean load which is less than closed configuration. this might be explained by the increased concentration of the load with the longer segment since number of the load carrying chains 'units or rings reduced as the link extension length was increased (6). consequently, further disruption of the molecular arrangement and more breaking of the intermolecular bonds being more with the long module than the short one. this in contrast to the closed elastomeric products, where the strain developed at the modular rings was much higher its degree in the open design so the higher number of rings closely packed to be as one unit (stiff body) possesses a higher strength (7-9). effect of chemical solutions the highly significant difference between the results of the samples that have been tested in distal water and different types of mouthwashes that has been used during this study; may be related to some factor or factors that are able to modify the physical properties of elastomers, such as the ph level, stretching, wet condition, thickness of elastic, temperature, time. ethanol is included in many types of mouth washes and at different concentrations range from (0.5-26.9%). it works as a dissolvent and carrier for active ingredients. listerine original mouthwash and ethanol 26.9% causes the highest level of force decay of elastomeric chains of all configurations, because when ethanol is analyzed microscopically emersion of polyurethane elastomeric modulus with 75% ethanol/water mixture causes molecular and structural modification leading to decay of elastomeric chains, listerine zero mouth wash have higher force values than ethanol or listerine original mouth wash for all types of elastomeric chains and whole testing period. so alcohol causes increase in force decay of elastomeric chains over time (5,10). although listerine zero contain sodium fluoride (naf 0.02%), it does not cause a significant increase in force degradation of elastomeric chain (11). at all the times, distilled water specimens exhibited higher force values than those in any other chemical solutions in the present study because these solutions contain components which facilitate migration by penetrating the polymer or increasing migrant solubility compared to the pure water (12). the present study suggests that alcoholic mouth wash (listerine original) causes increase force degradation of all types of elastomeric chains while alcohol free mouth wash (listerine zero) causes less force degradation of all types of elastomeric chains. also closed configuration elastomeric chains have the least percentage of force decay than other configurations. references 1. ash jl, nikolai rj. relaxation of orthodontic elastomeric chains and modules in vitro and in vivo. j dent res 1978; 57:685–90. 2. baty dl, storie dj, von fraunhofer ja. synthetic elastomeric chains: a literature review. am j orthod dentofacial orthop 1994;105: 536–542. 3. buchmann n, senn c, ballc j, brauchli l. influence of initial strain on the force decay of currently available elastic chains over time. angle orthod 2012; 80(3): 529-35. j bagh college dentistry vol. 28(2), june 2016 an evaluation the effect pedodontics, orthodontics and preventive dentistry 138 4. pinthon mm; santana da; sousa kh; farias im. does chlrohexidine in different formulations interfere with the force of orthodontic elastics? angle orthod 2013; 83(2):313-8. 5. larrabee tm, liu ss, torres-gorena a, soto-rojas a, eckert gj, stewart kt. the effects of varying alcohol concentrations commonly found in mouth rinses on the force decay of elastomeric chain. angle orthod 2012 sep; 82(5):894–9. 6. lu tc, wang wn, tarng th, chen jw. force decay of elastomeric chain a serial study. part ii. am j orthod dentofac orthop 1993; 104: 373-7. 7. eliades t, eliades g, watts dc. structural conformation of in vitro and in vivo aged orthodontic elastomeric modules. eur j orthod 1999; 21:649-58. 8. eliades t, eliades g, brantley wa, watts dc. elastomeric ligatures and chains. in: brantley wa, eliades t. orthodontic materials: scientific and clinical aspects. stuttgart: thieme; 2001. p.173-89. 9. hemed bm. the effect of drinks and food stimulants on the force applied by the orthodontic elastomeric chains (an experimental in vitro study). a master thesis, orthodontic department, university of baghdad, 2008. 10. eliades t, eliades g, silikas n, watts dc. in vitro degradation of polyurethane orthodontic elastomeric modules. j oral rehabil 2005; 32:72–77 11. ramazanzadeh ba; jahanbin a; hasanzadeh n; eslami n. effect of sodium fluoride mouth rinse on elastic properties of elastomeric chains. j clin pediat dentistry 2009; 34(2): 189–192. 12. long m. the effect of dietary liquids on the elastic properties of orthodontic elastics. usuniv kentucky chandler, medical center, strategic plan, 2005. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 1 research article assessment of alveolar bone height in adolescents utilizing cone beam computed tomography: a retrospective radiographic analysis zaid r. atarchi1,*, d douglas miley1, ahmed r atarchi2 1 southern illinois university school of dental medicine, alton, illinois, usa 2 bright now dental corporate, san francisco, california, usa * correspondence: ali.periodontics@gmail.com abstract: background: to assess the alveolar bone crest level (abcl) by cone beam computed tomography (cbct) and to investigate several variables as predictors for the height of the alveolar bone in adolescents. materials and methods: age, sex, and ethnic groups were recorded for each patient. cbct images were used to obtain measurements of the interproximal alveolar bone level from the cementoenamel junction (cej) to the alveolar crest. the highest measurement in each sextant was recorded along with any presence of a vertical bone defect or calculus. results: total of 720 measurements were recorded for 120 subjects. no vertical bony defects or calculus were observed radiographically. statistically significant (p< 0.05) differences were observed between abcl measurements of males as compared to females, posterior teeth compared to anterior teeth and maxillary sextants in comparison to mandibular ones. additionally, value of abcl significantly increased in relation to sex (r=0.309), maxillary posterior (r=0.509) and mandibular posterior sextants (r=0.506). linear regression analysis indicated that the latter variables can predict the height of marginal bone, other independent variables were considered redundant. conclusions: there was a low-profile of marginal bone loss among adolescents. male sex, posterior teeth, and maxillary teeth have higher tendency for decreasing alveolar bone height. keywords: adolescent, cone-beam computed tomography, alveolar bone introduction children and adolescence can have any of the periodontal diseases as an independent entity or as a manifestation of systemic disease. although periodontitis is more common in adults, the aggressive form is more prevalent among young patients (1, 2). periodontal disease in young patients is usually mild and rarely results in significant discomfort. mild disease can, however, progress into a more destructive one over time (3). generalized and localized forms of periodontitis have been identified affecting both the primary and permanent dentitions. the prevalence of periodontitis at a young age is low, but can be severe and rapidly progressing. early detection and diagnosis of periodontal disease by routine screening and periodontal examination will help to initiate treatment as soon as possible (3). race and ethnic backgrounds may have a role in the prevalence of periodontal disease in young individuals (4). for example, the prevalence of gingivitis is more often found in colombia and bolivia than with mexican children and adolescents (5). received date: 15-2-2022 accepted date: 10-3-2022 published date: 15-3-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/jbcd .v34i1.3086 mailto:%20ali.periodontics@gmail.com mailto:%20ali.periodontics@gmail.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3086 https://doi.org/10.26477/jbcd.v34i1.3086 j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 2 bitewing radiographs are usually taken in children for caries assessment, but they also show the alveolar bone height around teeth. thus, analysis of these radiographs provides a good assessment of the periodontal condition in children in addition to the clinical measurements of attachment level and gingival bleeding (6). albandar et al. (1991) used bitewing radiographs for the assessment of marginal bone levels in a 3-year study of brazilian adolescents. the conclusion was that they provided a useful method for monitoring disease progression (7). earlier studies using bitewing radiographs have shown that the incidence of bone loss in young patients varies between 0.8% and 20% which is much greater than that seen clinically (4). conventional radiographs are methods helpful in detecting the height of the alveolar bone crest but do not reveal information regarding the depth and width of bone defects. cone beam computed tomography (cbct) provides better diagnostic and measurable information on alveolar bone levels (8, 9). cbct provides high-resolution pictures combined with multilayer reconstructions and a high level of reproducibility (10). alveolar bone height can be accurately measured at buccal, lingual, mesial, and distal surfaces in young patients by utilizing cbct images which provide more direct measurements of the proximal areas with no need for calibration (11). the question of what constitutes a ‘‘normal’’ distance from the cementoenamel junction (cej) to crestal alveolar bone was addressed by hausmann et al. (1991) after perusal of contemporary literature revealed a lack of consensus (12). they demonstrated that a ‘‘no bone loss’’ distance ranging from 0.4 mm to 1.9 mm is consistent with no clinical attachment loss in 13to 14-yearold adolescents (12). in the literature, there are wide variations for normal bone height in relation to the cej, ranging from 1 mm to 3 mm. an average distance of 2 mm is widely adopted in studies of patients without periodontal disease. in young adults, the mean alveolar bone height in relation to the cej is 1.4 mm and for people over 45 years this average is extended to 3 mm (8, 9, 13, 14). the aim of this retrospective analysis was performed to assess the height of the alveolar bone crest level (abcl), as well as to examine the relationship between the patient age, ethnicity and sex with the alveolar bone height in adolescent patients aged between 14 to 18 years. materials and methods study design this retrospective analysis was conducted at saint louis university center for advanced dental education. this study was conducted after obtaining ethical approval in consistency with helsinki declaration for human studies. study population the radiographs of all adolescent patients 14 to 18 years of age and treated in the graduate orthodontics department from 2006 through 2015 was reviewed. for each patient, age, sex, and ethnic group were recorded. j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 3 inclusion criteria: 1. cbct images were available for the subject 2. no primary teeth were present 3. pre –orthodontic treatment radiographs were available 4. patient were seen for orthodontic screening from 2006-2015 exclusion criteria: 1. unavailable cbct for the subject 2. cbct with only single arch image was present for the subject 3. radiographs with major distortions of the examined areas 4. patients with cleft lip and/or palate measurement procedure the digital imaging and communications in medicine (dicom) multifiles of each cbct scan were imported into the dolphin 11.8 3d software (dolphin imagining systems llc, chatsworth, ca, usa) for analysis. cbct images were used to obtain measurements of the mesial and distal marginal alveolar bone height from the cej to the alveolar crest in all teeth. using a digital measurement tool provided in the imaging software, the 3d image was oriented so the occlusal plane was parallel to the horizontal plane (figure. 1). figure 1: standardized volume orientation of the cbct images, occlusal plane is parallel to the horizontal plane. panoramic images were constructed for each maxillary and mandibular arch of each subject with the axial plane at the level of the cej and the sagittal plane bisecting each tooth in a mesiodistal direction at the cej level. once oriented, this created a panoramic image for each dental arch (figure. 2a). from this image, measurements from the mesial and distal aspects of each tooth were made from the most apical portion of the cej (where proximal enamel ends at the root surface seen radiographically) to the most coronal aspect of the marginal bone crest (figure. 2b). the whole mouth was divided into 6 sextants; each dental arch was divided into posterior right, posterior left and anterior. the highest measurement in j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 4 millimetres in a sextant was recorded along with any presence of a vertical bone defect and/or the presence of calculus. the measurements of the posterior sextants were averaged and designated as “maxillary posterior” and “mandibular posterior”. there was a total of four scores for each subject; measurements were excluded from sites next to extracted, partially erupted or unerupted/impacted teeth and distal aspect of the second molars. in teeth that were restored with fillings or crowns and the cej was obliterated, the most apical limit of the restoration was considered to be equivalent to the cej and was used as the reference point (15). figure 2: (a) panoramic reconstruction from cbct for both arches, the axial plane placed at the level of cej and the tooth was divided mesiodistally at this point by the sagittal plane. (b) measurements in (mm) from the mesial and distal aspects of each tooth were made from the most apical portion of the cej to the most coronal aspect of the marginal bone crest: (i) maxillary right posterior sextant, (ii) mandibular right posterior sextant and (iii) mandibular anterior sextant. all the data was collected by one examiner (z. r. a.) who was calibrated by another expert dentist (d. d. m.) prior to collecting the measurements. statistical analysis j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 5 choice of statistical test to determine the differences in abcl according to different variables was based on results from shapiro-wilk w test. for normally distributed data, unpaired t-test was used dichotomized age groups while anova test was used for comparing difference in different sextants. when the data were not evenly distributed, mann-whitney test was used for determination of differences between males and females. multiple comparisons among different ethnic groups were performed by using kruskal-wallis test. all multiple comparison analysis (anova, kruskal-wallis) were followed by posthoc test. correlation of abcl, dependent variable, with different independent variables was determined by using backward linear regression analysis. statistically significant level was set at p< 0.05. all statistics was performed by using statistical product and service solutions (spss) (version 25, ibm, usa). results the number of the patient records included in the final analysis was 120 out of 747 records in this retrospective analysis, 627 records were excluded based on exclusion criteria. the total number of the measurements was equal to 720. the average age of the adolescents included in this study was 15.43 years and ranged between 14-18 years (table 1). distribution of the study population according to sex, ethnicity, age groups, and sextants is illustrated in table 1. table 1: demographic variables of the study population mean age (years)± sd 15.43± 1.06 median age 15 age range (years) 14-18 sex male 62 (51.7) § female 58 (48.3) § ethnic group white 88 (73.3) § african american 24 (20) § hispanic 8 (6.7) § age groups (years) 14 21 (17.5) § 15 53 (44.2) § 16 25 (20.8) § 17 16 (13.3) § 18 5 (4.2) § total 120 (100) § § frequency (percentage) analysis of the radiographs showed no vertical bony defects or calculus were identified in the total sample. the mean abcl for all teeth was 1.6± 0.2 mm. the highest measurement recorded for abcl was 2.5 mm and the lowest was 0.8 mm. measurements of abcl were significantly higher in males than females; however, no significant difference was observed among different ethnic and age groups (table 2). j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 6 according to the sextants, maxillary posterior teeth showed significantly higher abcl measurements than all other sextants. mandibular posterior teeth had significantly higher abcl than anterior teeth in both jaws. yet, maxillary and mandibular anterior teeth did not show any significant difference in abcl among them (table 2). in addition, average abcl measurements of the maxillary sextants were significantly higher than their mandibular counterparts (table 2). table 2: comparisons of abcl according to different variables variables mean± sd (mm) comparisons p value* sex† male 1.452± 0.192 male vs. female < 0.001 female 1.586± 0.221 ethnic group§ white 1.500± 0.199 african american vs. hispanic ns african american 1.592± 0.268 african american vs. white ns hispanic 1.538± 0.228 hispanic vs. white ns age groups (years)¶ ≤ 15 1.520± 0.187 ≤ 15 vs > 15 ns > 15 1.523± 0.261 sextants ǂ max anterior 1.358± 0.284 max anterior vs. mand anterior ns mand anterior 1.298± 0.337 max anterior vs. mand posterior < 0.001 max posterior 1.766± 0.238 max anterior vs. mand posterior < 0.001 mand posterior 1.664± 0.261 mand anterior vs. max posterior < 0.001 mand anterior vs. mand posterior < 0.001 max posterior vs. mand posterior 0.031 jaws¶ max 1.630± 0.213 max vs mand 0.004 mand 1.542± 0.254 total sample 1.6± 0.2 * significant level at p< 0.05 by using: † mann-whitney test, § kruskal-wallis test, ¶ unpaired t-test, ǂ anova test ns, non-significant regression/correlation analysis was used to assess the association between the overall average abcl (dependent variable) and the independent variables of this study. results indicated a positive and significant relation between increasing abcl measurements with male, mandibular anterior, and posterior sextants in both jaws (table 3). backward regression analysis showed that the predictors for increasing abcl measurements were sex and posterior sextants of maxillary and mandibular jaws after excluding other independent variables (table 4). j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 7 table 3: correlation between abcl and different independent variables independent variables r† p value* age 0.079 0.197 sex 0.309 < 0.001 ethnic groups 0.127 0.084 max anterior teeth 0.097 0.147 mand anterior teeth 0.201 0.014 max posterior teeth 0.509 < 0.001 mand posterior teeth 0.560 < 0.001 † pearson’s correlation coefficient * significance at p< 0.05 table 4: regression analysis for predictors of abcl (dependent variable) variables a r^2 std. error of the estimate 95% ci t p value sex 0.137 0.20400 0.061-0.208 3.610 0.001 max posterior teeth 0.259 0.18815 0.231-0.437 6.428 0.0001 mand posterior teeth 0.318 0.18111 0.276-0.480 7.344 0.0001 a variables excluded by backward method were age, ethnic group, upper and lower anterior teeth discussion the current cbct-based retrospective analysis showed that the average abcl in adolescent subjects was equal to 1.6 mm. however, an increase in the distance from the cej to the crest of the alveolar bone at the interdental areas was associated positively with the sex of the subject and posterior location of the teeth. early detection of periodontal disease in children and adolescents ensures a high likelihood of a successful therapeutic outcome, primarily by reduction of etiologic factors, remedial therapy and development of an effective maintenance protocol (3, 16). radiographs contribute not only in the diagnosis of periodontal disease but also in the assessment of the prognosis of periodontally involved teeth, development of a treatment plan and the evaluation of the recurrence or progression of the disease (17). in comparing periapical radiographs with cbct imaging for detecting alveolar bone loss, cbct was the only method that allowed for an analysis of different tooth surfaces and an improved visualization of the morphology of a bony defect (9, 18). when compared with conventional radiography, the cbct radiation dose is equivalent to a full-mouth series and approximately three to seven times the dose of a panoramic radiograph depending on the setting in use. on the other hand, when compared with conventional radiography, cbct has far greater potential for providing information (8, 9, 19). cbct was used in this study because it provides the most accurate measurements from the regular radiographs used for patient screening. linear measurements between the cej and the alveolar crest or the bottom of the bony defect are used often to characterize the amount of bone loss in osseous periodontal defects (15). in the current study, j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 8 the highest abcl measurement recorded was 2.5 mm, while the lowest was 0.6 mm which is in agreement with results from previous studies (8, 9, 20) who reported normal bone height in relation to the cej might range from 1 mm to 3 mm, although a distance of 2 mm is more widely adopted in studies of patients without periodontal disease (21). in young adults, the mean alveolar bone height in relation to the cej is 1.4 mm and for people over 45 years this average is extended to 3 mm (22). armitage (1999) stated that the radiographic measurement of the cej to bone crest of 2 mm or more is an appropriate cut-off point for bone loss (23). darby et al. (2005) considered no bone loss if the distance from the cej to abcl was ≤2 mm; questionable bone loss if the distance from the cej to abcl was >2 and <3 mm; and definite bone loss if the distance from the cej to abcl was ≥3 mm (4). there was a statistically significant difference in abcl between the mandibular and maxillary teeth. a lower prevalence of significant differences in the mandible would seem to be consistent with previous literature (21, 24) and might be attributed to relatively simpler root anatomy and more favorable radiographic conditions in mandibular molar and premolar areas (24). furthermore, direct measurements of the alveolar bone crest (abc)-cej distances from dried skulls of a romano-british population were also greater for maxillary posterior teeth with a reverse trend noted for the anterior region (25). there was a statistically significant difference between the values of the anterior and posterior teeth abcl. this is not in accordance with other studies that found higher abcl in anterior teeth versus posterior teeth (22). in general, the diagnostic accuracy of imaging modalities was low for anterior teeth. the difference in the diagnostic accuracy of cbct between anterior and posterior teeth is likely the result of the difference in the morphology of the alveolar bone between these areas (8). the mean abcl for females was significantly lower than their male counterparts. this is in accordance with other studies that found an association between sex and the prevalence of periodontal disease in which more males than females showed evidence of periodontal breakdown (26, 27). overall, males were found to have significantly greater abc-cej distances than females. however, it must be remembered that in the vast majority of cases the results for males were still within the range consistent with periodontal health that is less than 3 mm (28). further support was obtained from regression analysis which showed that sex together with posterior location of the teeth in the oral cavity can be used as predictors for increasing abcl measurements. other variables were excluded from the backward regression model including the age, ethnic groups, and anterior teeth in the maxillary and mandibular jaws. the overall abccej distance increases with age (29); however, this is not a linear relationship but follows the pattern of facial growth. the results of one study indicate that different levels of abc-cej distances might be considered as a cut-off value for radiographic diagnosis of alveolar bone loss at different ages (25, 26, 30). ethnic differences in periodontal bone loss have been well documented in many studies (5, 21, 31, 32). which is inconsistent with findings of our study regarding ethnicity. there are significant racial differences in both the prevalence of early-onset forms of periodontitis and associated host factors. it is currently unclear whether these differences are due to genetic or environmental factors. whether one group are truly more susceptible to periodontitis than other racial groups remain to be fully clarified. undoubtedly periodontal epidemiology is advancing, but issues relating to definition of the clinical signs of periodontitis and how to factor in tooth loss due to periodontitis have not yet been resolved. j. bagh. coll. dent. vol. 34, no. 1. 2022 atarchi et al 9 destructive periodontal diseases have also been reported disproportionately more prevalent and severe in aa relative to other american populations. differences in subgingival microbiota and host immune response have also been reported for aa, implying that risk factors for disease progression may also differ for these populations. although greater destructive periodontal disease prevalence and severity were found in the aa group, environmental and demographic variables, such as occupational status, may have a greater influence on risk indicators associated with disease prevalence and progression in these populations (32, 33). limitations to retrospective studies is that they only provide information about association not causation. another limitation to cbct imaging has been reported in a previous study (34) is that different sagittal planes positions may alter the severity of bone loss in the anterior teeth. for our study, it should also be stressed that these results relate to a population seeking care at a dental school. the question arises whether patients seeking dental care at a dental school are representative of the community population. conclusions this study revealed that male gender, posterior teeth and maxillary teeth expressed higher abcl values than other independent variables within the adolescent population. thus, they could potentially be used as predictors for marginal bone height. further researches are necessary to establish whether this difference is attributable to disease, biologic factors, or environmental factors. conflict of interest: none. references 1. califano jv. position 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measures of periodontal status and demographic and behavioural risk factors. j clin periodontol. 2005;32:798-808. 34. zhang x, li y, ge z, zhao h, miao l and pan y. the dimension and morphology of alveolar bone at maxillary anterior teeth in periodontitis: a retrospective analysis—using cbct. int j oral sci. 2020;12:4. رجعي بأثر شعاعي تحليل : المخروطي للشعاع المحوسب المقطعي التصوير باستخدام المراهقين عند السنخي العظم ارتفاع تقييم العنوان: 2, احمد رمزي عطرجي 1دوكالس مايلي, 1رمزي عطرجيزيد الباحثون: المستخلص: عند السنخي العظم الرتفاع كمؤشرات المتغيرات من العديد من وللتحقق( cbct) المخروطية للحزمة المحوسب المقطعي التصوير بواسطة( abcl) السنخي العظم قمة مستوى لتقييم: الخلفية . المراهقين سمنت الجذر و المينا تقاطع من القريب السنخي العظم لمستوى قياسات على للحصول cbct صور استخدام تم. مريض لكل العرقية والمجموعات والجنس العمر تسجيل تم: والطرق المواد (cej )القلحوجود أو العظام في عمودي عيب أي وجود مع من كال الفكين سدس كل في قياس أعلى تسجيل تم. السنخية القمة إلى . للذكور abcl قياسات بين( p <0.05) إحصائية داللة ذات فروق لوحظت. إشعاعيًا األسنان رواسب أو رأسية عظمية عيوب أي الحظ ي لم. شخصاً 120 لـ قياسًا 720 إجمالي تسجيل تم: النتائج ( r = 0.309) بالجنس يتعلق فيما ملحوظ بشكل abcl قيمة زادت ، ذلك إلى باإلضافة. االسفل بالفك مقارنة االعلى واالسنان في الفك األمامية باألسنان مقارنة الخلفية واألسنان باإلناث مقارنة الهامشي العظم بارتفاع تتنبأ أن يمكن األخيرة المتغيرات أن إلى الخطي االنحدار تحليل أشار(. r = 0.506) السفلي الخلفي الفكو( r = 0.509) الخلفي العلوي والفك ، . العلوية واألسنان الخلفية األسنانفي و بين الذكور السنخي العظم ارتفاعضافة الى ذلك يقل ا. المراهقين بين الهامشي العظام فقدان مستوى في انخفاض هناك كان: االستنتاجات athraa final.doc j bagh college dentistry vol. 26(2), june 2014 occupational dental orthodontics, pedodontics and preventive dentistry 135 occupational dental wear among el-kubasis cement factory workers an observational study mohammed i. abdulla, b.d.s. (1) athraa m. al-waheb, b.d.s., m.sc. (2) abstract background: loss of tooth structure may be due to tooth to tooth contact and presence of abrasive components in the work environment. the aim of study was planned to evaluate the occurrence of dental attrition among cement factory workers. material and method: the sample included all workers chronically exposed to cement dust in the el-kubaisa cement factory (95 workers). a comparative group of workers (97) were non-exposed to cement dust was selected. all workers were males in gender with age range (25-55) years. the assessment of tooth wear was based on the criteria of smith and knight, 1984. results: the maximum tooth wear score for exposed workers was 84.2% while non exposed workers was 38.1%,with statistical differences between two groups was highly significant (p<0.01). the maximum tooth wear score among workers exposed to cement dust according to duration (<10years), (10-20 years) and >20 years) was (52.2 %), (92.3%) and (100%) respectively, with statistical differences was highly significant (p< 0.001). while the maximum tooth wear score among workers exposed to cement dust according to wearing mask was found to be statistically not significant (p> 0.05). conclusion: work environment was related to dental wear. key word: attrition, cement dust, cement factory worker. (j bagh coll dentistry 2014; 26(2): 135-137). : الخالصة إن الھدف من ھذه الدراسة ھو تقییم وقوع تآكل األسنان بین . إن فقدان بنیة األسنان قد یكون سببھ الرئیسي ھو تآكل األسنان مع وجود مواد تساعد على االحتكاك في بیئة العمل : المقدمة .عمال مصنع االسمنت جمیع العمال . غیر معرضین للغبار ) عامال 97( مقارنة مع ) . عامال 95(غبار االسمنت في مصنع اسمنت كبیسة لمزمن شملت العینة جمیع العمال المعرضین بشكل :المواد و العمل . 1984واستند تقییم تآكل األسنان على معاییر سمیث و نایت ، . سنة) 5525( ذكور و في الفئة العمریة ٪ ، مع فروق ذات داللة إحصائیة بین مجموعتین 38.1٪ بینما العمال غیر المعرضین للغبار كان 84.2ضین للغبار كان الحد األقصى لدرجة تآكل األسنان للعمال المعر :النتائج 52.2( ھو ) نةس 20اكبر من ( و ) سنة20 -10(, ) سنة10اقل من ( وكان أقصى درجة تآكل األسنان بین العمال المعرضین لغبار األسمنت وفقا لمدة ) . p<0.01(كان كبیرا للغایة في حین تم العثور على الدرجة القصوى لتآكل األسنان بین العمال المعرضین لغبار األسمنت وفقا ) . p 0.01>(على التوالي ، بفروق إحصائیة عالیة ) ٪ 100( و ) ٪ 92.3( ، %) .)p>0.05(الرتداء الكمامات مع فرق غیر معنوي .تآكل األسنان بیئة العمل متعلقة بحالة: االستنتاج .غبار االسمنت ، عمال مصنع االسمنت, تآكل األسنان :كلمات مفتاحیھ introduction oral cavity injuries which occur as a direct result of an occupation are rather common. the injurious effects of occupational hazards may manifest themselves in the teeth, jaw bones, periodontal tissue, tongue, lips and oral mucosa. the effect of the various etiological agent depend on their specific chemical and physical properties (1). occupational hazards are major contributors to additional risk factors for disease. industrialization of nations exposes its population to this risk. the working environment influences the health of an individual. the occupational diseases are caused by a pathologic adaptation of the individual to his working environment (2). as abrasive components exist in several work environments, wasting diseases of teeth may be considered as an occupational dental disease. this dental condition has been reported in workers of granite industry. loss of tooth structure may be due to tooth to tooth contact and presence of abrasive components in the work environment (2). (1)m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, baghdad university. (2)professor, department of pedodontics and preventive dentistry, college of dentistry, baghdad university. as cement factory workers are exposed to cement dust and this dust contain different minerals like silica, iron and others elements, therefore, the present study was planned to evaluate the occurrence of dental attrition amongst cement factory workers. materials and methods sample the survey took place in 2012-2013. the present study was conduct in el-kubaisa cement factory located in al-anbar governorate. the sample included all workers chronically exposed to cement dust in the el-kubaisa cement factory (95 workers) and who were working in department where cement dust exposure was present with duration at least 5 years. a comparative group of (97) workers who were nonexposed to cement dust was selected randomly from other department non-expose to cement dust. all workers were males in gender with age range (25-55) years. methods oral examination of all workers was done in room in cement factory using artificial light. the j bagh college dentistry vol. 26(2), june 2014 occupational dental orthodontics, pedodontics and preventive dentistry 136 assessment of tooth wear was based on the criteria of smith and knight, 1984. this index was chosen due to easily comparable and widely use. the present study was carried out according to duration in work and wearing mask. data analysis data were translated into a computerized data base structure. the data base was examined for errors using range and logical data cleaning methods. statistical analyses were done using spss version 20 computer software (statistical package for social sciences) in association with excel version 5. pearson’s chi-square test was used to test the differences between different groups. for all of the tests, a p value of < 0.05 was considered to be statistically significant. results the study sample consisted of 192 workers (95 exposed to cement dust) and (97 nonexposed). the study subjects were ranging from ages (25-55) years. tooth wear was assessed using criteria of smith and knight 1984. result concerning the maximum tooth wear score of the total sample (exposed and non-exposed) illustrated in table (1). the maximum tooth wear for exposed workers was 84.2% while non exposed workers was 38.1%, with statistical differences between two groups was highly significant (p< 0.01). table (2, 3) shows that the maximum tooth wear score among exposed workers according to duration of current employment (<10years), (10-20 years) and (>20 years) was (52.2 %), (92.3%) and (100%) respectively and according to wearing mask (never), (sometime) and (always) was (76.2%), (86.2%) and (88.9%) respectively. with statistical differences among exposed workers according to duration was highly significant (p<0.001) and no significant differences according to wearing mask (p> 0.05). table 1: distribution of study subject (workers exposed and non-expose to cement dust) according to maximum tooth wear score. maximum tooth wear score expose to cement dust p (chisquare) non expose expose no. % no. % score – 0 24 24.7 5 5.3 0.001* score – 1 2 2.1 0 0.0 ns** score – 2 34 35.1 9 9.5 0.001 score – 3 37 38.1 80 84.2 0.001 score – 4 0 0.0 1 1.1 ns *high significant at p<0.01, df=1, **not significant at p>0.05 ** table 2: distribution study subjects (workers exposed to cement dust) according to maximum tooth wear score and duration of current employment. duration of current employment maximum tw score <10years 10-20years >20years p (chisquare) no. % no. % no. % score 0 5 21.7 0 0.0 0 0.0 0.001* score 1 0 0.0 0 0.0 0 0.0 ** score 2 6 26.1 3 5.8 0 0.0 0.001 score 3 12 52.2 48 92.3 20 100 0.001 score 4 0 0.0 1 1.9 0 0.0 ns total 23 100 52 100 20 100 *high significant at p<0.01, df=2 , ** can not calculated table 3: distribution of study subject (workers exposed to cement dust) according maximum tooth wear score and wearing mask maximum tw score never sometime always p (chisquare) no. % no. % no. % score 0 1 4.8 4 6.2 0 0.0 ns* score 1 0 0.0 0 0.0 0 0.0 ** score 2 3 14.3 5 7.7 1 11.1 ns score 3 16 76.2 56 86.2 8 88.9 ns score 4 1 4.8 0 0.0 0 0.0 ns total 21 100 65 100 9 100 *not significant at p> 0.05, ** can not calculated discussion the smith and knight (3) index was used in this study for the assessment of the prevalence of tooth wear among workers of el-kubasia cement factory. this index was chosen for its easily comparison and it’s also widely use. in present study maximum tooth wear score among workers exposed to cement dust in el-kubasia cement factory was found to be much higher (84.2%) compared to non exposed (38.1%). statistically high significant differences between exposed and non-exposed workers were shown in the present study. this is may be due to that the workers may develop disorder of teeth because of exposure to chemical substance, organic or inorganic, specific to their occupation (4). the cement factories provide an environment which may contain abrasive particles in form of silica and other minerals dust. abnormal tooth surface loss in form attrition or abrasion could be squealed to occupational exposure. petersen and gormsen have termed such effect on dentition as occupational disease (5). the result of present j bagh college dentistry vol. 26(2), june 2014 occupational dental orthodontics, pedodontics and preventive dentistry 137 study is agreed with study done by el-ghandour (6) on rabak cement factory workers in sudan the prevalence of attrition was 84.85% and study reported by sood et al (2) on ceramic factory workers the prevalence of attrition was 84.36% and higher than recorded by tuominen (7) on stone and cement factory attrition was 72.2 %. the differences in these finding may be related to wide range of tooth wear indices used and the variation in diagnostic criteria (8). currently there is no agreed consensus on universally acceptable tooth wear index for quantifying tooth wear (9). these factors complicate the evaluation of whether a true increase in prevalence is being reported. therefore conclusion from prevalence studies should be considered with caution (10). in present study maximum tooth wear score among exposed workers was found (84.2%). statistically high significant differences (p<0.01), this is may be due to dust of abrasive quality such as cement may collect on occlusal surface of teeth, produce friction and cause damage to the teeth and generalized attrition. such condition found among cement stand workers, grinders, stone cutters and miners (4). excessive dental wear reported in a study in danish granit industry (11), which has been attributed to the abrasive component of the work environment. in present study dental wear increase with increase duration of current employment among exposed workers. less than 10 years was 78%, 10-20 years was 97% and more than 20 years was 100%. this relation was found to be statistically high significant in present study (p<0.01). this agreed with study done by ptersen and henmar (11) on danish granit workers they reported workers with duration less than 10 years tooth wear was 64% while the workers with duration more than 10 years tooth wear was 87%. the increase severity of tooth wear attributed to increase duration of exposure to cement dust. maximum tooth wear among exposed workers according to wearing mask was no significant (p< 0.05), this may be attributed that wearing mask not protect the mouth from dust of cement, because of the mask that wearing in factory not systemically (not manufactory for this purpose) therefore it isn't affective to prevent tooth wear. as conclusion; dental wear among workers exposed to cement dust higher than non exposed workers statistically high significant differences between two groups. the prevalence and severity of tooth wear increased with increasing duration and this relation was found to be statistically highly significant. work environment was related to dental wear. references 1. lammert k, seifert h. stomatologie and arbeitsmedizin veb verlag volk and gesundheit, berlin 1979. 2. sood m, blaggama a, blaggama v, sharma n. occupational dental wear among ceramic factory workers–an observation study. jida 2011; 5(4):4723. 3. smith b, knight j. an index for measuring the wear of teeth. br dent j 1984; 156(12): 435-8. 4. gupta b. occupational diseases of teeth. j soc occup med 1990; 40: 149-52. 5. petersen p, gromsen c. oral condition among germany battery factory workers. comm dent oral epidemiology 1991; 19: 104-6. 6. el-ghandour i. the effect of cement dust on the periodontal health of workers in rabak cement factory. master thesis, college of dentistry, khartoum university, 2006. 7. tuominen m, tuominen r. tooth surface loss and associated factors among factory in finland and tanzania. community dent health 1992; 2:143-50. 8. bardsley p, taylor s, milosevic a. epidemiological studies of tooth wear and dental erosion in 14 year old children in north west england. part 1: the relationship with water fluoride and social deprivation. br dent j 2004; 197:413-6. 9. bartlett d, dugmore c. pathological or physiological erosion is there relationship to age. clin oral investing 2008; 12: 27-31. 10. pardsley p. the evaluation of tooth wears indices. clin oral investing 2008; 12: 15-9. 11. petersen p, henmar p. oral conditions among workers in the danish granite industry. scand j work environ health 1988; 5: 328-31. j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 44 effectiveness of intra articular injection of platelet-rich plasma in patients with anterior disc displacement with reduction farah taha a. alhussien b.d.s., msc (1) ameena ryhan m.sc.ph.d (oral medicine) (2) abstract background: anterior disc displacement with reduction (addwr) is the most common form of the internal derangement (id) of temporomandibular joint (tmj). it is a painful progressive dysfunction and clinically characterized by reciprocal clicking due to shift in the disc anteriorly in relation to the condyle and fossa during mandible elevation. minimally invasive therapy such as intra-articular injection of platelet-rich plasma (prp) has been used. prp is a natural autologous product with a high platelet concentration obtained by centrifugation process to enhance tissue healing through several growth factors (gfs), which are released after endogenous activation. the aim of this study is to assess this technique which is increasingly used today as a safe, simple modality. materials and methods: sixty patients with addwr were participated (females 41, males 19; age 20-39 years). patients were divided into two groups; prp was used as study group and conservative therapy was used as control group. 1 ml of prp was obtained by a single step centrifugation. pain, joint sounds and maximum mouth opening were clinically evaluated before and two months after therapy. results: there was statistically significant improvement in pain score, clicking and maximum mouth opening in patients treated with prp. no complications were recorded immediately and two months after therapy. conclusion: this study support the effectiveness of prp injection in treatment of addwr as a safe modality in reducing pain, clicking and increase mouth opening. kay words: articular disc, conservative, intra-articular injection, platelet-rich plasma. (j bagh coll dentistry 2017; 29(4): 44-52) introduction: anterior disc displacement with reduction (addwr) is an abnormal relationship between disc, condyle, and the articular eminence, due to elongation or tearing of the attachments between disc, condyle and glenoid fossa (1). it is one of the most frequent cause of temporomandibular disorders (tmds) (1). chronic micro-trauma is the most important etiological factor of addwr, resulting from longstanding bruxism or clenching of teeth or from direct trauma to the joint (2). the principal goal of the therapeutic management for addwr is to relief pain, preserve normal range of motion and prevent excessive joint damage (3). many conservative methods suggested for addwr including patient education and self-care, physical, intraoral appliance therapy and pharmacotherapy that should be initially used before any invasive treatment (3). 1) master student, oral medicine, department of oral diagnosis, college of dentistry/ university of baghdad, raq 2) assistant professor, department of oral diagnosis oral medicine college of dentistry, university of baghdad. platelet-rich plasma (prp) is a blood derivative of high platelet concentration compared to the whole blood (4). it has been used in the treatment of addwr (4), because of its influence on the entire joint environment and produces a good therapeutic effect in patients with clicking, pain and limitation in mouth opening (5). it may be obtained through a simple and unexpensive technique via withdrawal and centrifugation of a sample of patients own blood. prp contain high number of gfs in alpha granules, which when activated endogenously, a cluster of gfs and biologically active molecules were released, were which found to have an anti-inflammatory, antibacterial and analgesic properties (6). materials and methods the subjects: sixty iraqi patients (41 females and 19 males) were participated in this prospective study, with their age range was between 20-40 years, they were divided into two groups; first group were thirty patients who had addwr, who did not respond to a previous conservative therapy, thus received prp injection( (study group). the second group were also thirty patients who received a conservative treatment and was considered as a control group. all participants attended to the j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 45 maxillofacial department of al-yarmouk teaching hospital during the period from november 2015 to may 2016, were asked to take part in this study. patients were informed about the study aims and objectives and given their written consent form before participating in the study. patients with pain in temporomandibular joints, limitation in mouth opening and clicking were included in this study while patients with thrombocytopenia or any platelet dysfunction, patients who had inflammatory or connective tissue disease, patients who received anticoagulant medications, patients with tumor or premalignant lesion at the site of procedure, patients with possible compromised immune system and pregnancy were excluded from this study. clinical assessment: the patients assessed their pain intensity using visual analog scale (vas) from 0: no pain to 10: the worst imaginable pain. noise within joint movement was assessed through palpation and maximal interincisal opening (mio) was clinically measured and recorded in millimeters. all these assessments were performed prior to prp injection, then 1 and 2 month after injection. plateletrich plasma preparation a. blood collection: using 10 ml syringe gauge 21, eight milliliters of autologous venous blood sample was taken from antecubital vein. the blood sample then was drown into prp vacuum tube containing acid citrate dextrose (acd-a) as an anticoagulant agent. b. the centrifugation. the procedure of prp preparation was preformed according to mazzocca et al., (7) 1. after blood sample collection, gently mixing the blood in prp tube. 2. centrifuge the prp tube at 3000 rpm for 9-10 minute by placing another tube in the opposite side with the same weight, containing normal saline for balancing. 3. after centrifugation, the buffy coat layer is located on the upper surface of the visible gel and the red blood cells located on the bottom. never open the prp tube, discard 2/3 from the platelet poor plasma (ppp) by using spinal needle gauge 22. 4. leave the tube in the rack for at least 15 minutes to insure the re-attachment of the hydrogen bounding in silica matrix gel to avoid the breakdown of gel. 5. gently, mixing the remaining plasma with the buffy coat to insure dissolving all the buffy coat platelet which is located over the visible gel. 6. aspirate the prp by using a sterile 1 ml syringe with spinal needle (avoid touching the gel by needle). 7. discard the needle and use a new needle with gauge 23; prp process is ready for injection. prp injection therapy and patient follow-up: patient indicated for prp was prepared by drawing a line from the middle tragus of the ear to the corner of the eye to determine the injection point, which is located along the line; 10 mm forward from the middle tragus and 2 mm below the line (8,9).firstly, tmj region was washed with an antiseptic solution to decontaminate the field. then the patient was asked to open his/her mouth half opening and the pre-aueicular concavity was formed at the marking point of the injection. one ml of prp was injected into the superior joint space with the needle being directed medially and slightly antero-superiorly until a contact with glenoid fossa was achieved (10). after prp injection into the joint space, the needle then withdrawn and the skin disinfected again (10). according to di matteo et al, (10) the patient was asked to open and close his/her mouth several times for a minute to ensure equal distribution of prp in the joint space. patient informed about the possibility of experiencing an unpleasant sensation of fullness or compression and mild pain in the joint region, which may be resolved by itself within a period of a week without an intervention. a soft diet was advised for two weeks after the prp injection. anti-inflammatory medications were not advised in order to avoid the analgesic effect of the medication during the documentation of pain relief period (11). patient’s follow-up was performed, one and two months after prp injection to assess the patient pain, range of mouth opening and tmj sounds (12). during the follow up period, all postoperative complications and adverse effects were recorded if present. statistical analysis: data were analyzed using spss (statistical package for social sciences) version 22 software package. continuous variables presented as means with standard deviation, discrete variables presented as numbers and percentages .t test was used to test the significance of observed differences in mean of two independent samples. chi square test was used to test the significance of j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 46 association between discrete variables. t test for paired samples was used to test the significance of observed differences in mean of two independent samples. findings with p value less than 0.05 were considered significant. results: a total of sixty iraqi patients were in rolled in this study. considering prp group of patients, 67% (20) were females and 33% (10) were males. in conservatively treated group of patients, 70% (21) were females and 30% (9) were males. the age range of patients was from 20-39 years with a mean of 30.4 years (sd: ±6.8). considering pain intensity, at the first presentation, pain intensity in prp patients was found to be from 2-10 with a mean of 7.1 (sd: ±2.0), while pain intensity in conservatively treated patients was found to be from 3-10 with a mean of 6.0 (sd: ±1.8). a significant difference in pain intensity between prp and conservatively treated patients was found at presentation time; prp patients showed a higher mean of pain intensity (p < 0.030). after prp therapy, at the end of the first month, prp patients pain intensity was from 0-8 with a mean of 1.5 (sd: ±2.6), while pain intensity of the conservatively treated patients was from 0-5 with a mean of 0.8(sd: ±2.6). at the end of the second month, prp patient’s pain intensity was from 0-8 with a mean of 1.5 (sd: ±2.6). pain intensity in conservatively treated group was from 0-8 with a mean of 4.6 (sd: ±2.5). a significant difference in pain intensity between both groups was found (at the end of 2nd month); prp patients showed lower means of pain intensity compared to the control group (p < 0.001) (figure1) fig 1: visual analogue scale mean of study population at different time points. the quality of pain improvement was assessed at the last follow-up appointment of patients (at the end of the 2nd month). the vas score for pain improved significantly in prp patients (p<0.001); 93% of patients showed a significant reduction in pain at the tmj region compared to only 40% of the control group who showed a pain reduction improvement. regarding tmj clicking, all prp and conservatively treated patients were presented with clicking at 1st presentation. at the end of the 1st month, only 10% of prp patients showed disappearance of clicking, 73% showed decrease in clicking frequency, while the rest of patients (17%) experienced no changes in their clicking sounds. at the end of the second month, only 3% of prp patients showed disappearance of clicking, 70% showed reduction in clicking frequency and 27% showed no changes in their clicking sound. statically, no significant difference was found in relation to clicking within prp group of patients (p>0.05). on the topic of the mouth opening, in prp patients, the range of mouth opening without pain was from 12 to 35 mm with a mean of 24mm (sd: ±5.3). following prp therapy, the range of the mouth opening without pain was from 15-39 with a mean of 27.8 mm (sd: ±5.1) at the end of the first month. at the end of the second month, the range of mouth opening without pain was from 1843 mm with a mean of 31.8 mm (sd: ±5.2) regarding conservatively treated patients, at the first presentation, the range of mouth opening without pain was from18-49 mm with a mean of 31.9 mm (sd: ±8.0). at the end of the 1st month, the range of the mouth opening without pain was from 20-29 with a mean of 35.5 mm (sd: ±6.3). at the end of the 2nd month, the range of the mouth opening without pain was from 21-50 mm with a mean of 35.0 mm (sd: ±6.3). statically, a significant differences were found between both groups at the first presentation & at the end of the 1st ,2nd month; prp patients showed a lower mean of the mouth opening compared to the conservatively treated patients (p < 0.001, p < 0.001, p < 0.041).table 1 table 1: range and mean of mouth opening at presentation and two months after prp therapy. variables prp patients (mm) conservatively treated patients (mm) p value j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 47 first presentation range 12-35 18-49 mean ±sd 24 ±5.3 31.9±8.0 <0.001 end of the 1st month range 15-39 20-49 mean ±sd 27.8±5.1 35.5±6.3 <0.001 end of the 2nd month range 18-43 21-50 mean ±sd 31.8±5.2 35.0 ±6.6 0.041 discussion: the present study was conducted to investigate the effectiveness of prp injection as a biological approach in the treatment of tmj disorders with respect to pain, clicking and mouth opening in patients with anterior disc displacement with reduction. demography of patients: age in this study, the mean age of patients was 30.4 years which is in line with the fact that the age group between 20-40 years have a greater risk for developing tmd than others (13). this may be related to stress factors, quality of life which has a direct influence on the prevalence of tmd (14). while in advancing age, signs and symptoms become less or undetectable (15). these results are in agreement with marcelo et al. (16) who studied the severity of tmd in relation to age and they found that there is no correlation between age and the severity of tmd; however there was a trend of greater severity of tmd in young adults (25-50 years). gender in this study, females were more common than males in both prp and conservatively treated patients. this can be explained by the fact that female patients may suffer from high level of pain and dysfunction and longer persistence of symptoms over a long duration of time due to the hormonal, behavioral and psychological problems (17). females have a 3-folds higher risk to develop tmd than males, according to studies conducted by velly et al. (18) and marcelo et al. (16); both studies showed that there is a greater involvement and increase expression of signs and symptoms in females than males. this result is in the line with steven et al. (19) study who showed that the functional estrogen receptors have been identified in females tmjs but not in males tmjs. estrogen may also promote degenerative changes in the tmj by increasing the synthesis of specific cytokines, whereas testosterone may inhibit these cytokines (20). tmj pain-visual analogue scale (vas) in the present study, vas scale was used to determine the pain intensity which was recorded at three time-points. a significant reduction in the mean pain intensity was recorded at the 1st followup after prp therapy. this is supported by a study conducted by hanci et al. (21) who reported a pain reduction in 20 cases of tmj dysfunction treated with prp. also this result is in line with a comparative study done by sanchez et al. (22) on 60 patients with knee osteoarthritis; 30 of them were treated with prp injection and 30 with hyaluronic acid. after 5 weeks, there were a better efficacy in pain reduction and subsequent improvement in joint function in prp group. similarly, sampson et al. (23) noted a reduction in pain and disease improvement in 14 patients with knee osteoarthritis in 6-momths follow-up. current study is in consistent with a study conducted by filardo et al. (24) who reported a significant pain reduction in 91 patients with chronic degeneration of knee in 12 months followup study; similar results were seen by kon et al. (25) and napolitano et al. (26) who recorded a noticeable pain reduction in 150 and 27 patients respectively treated with prp for osteoarthritis of the knee joints. lee et al. (27) examined the role of prp as an analgesic compound through adding prp to a culture of chondrocyte leading to direct increase in mrna levels of cannabinoid receptors cb1 and cb2, which has both analgesic and antiinflammatory effects. it is well known that pain of tmj is mostly associated with changes in the biochemical components of the synovial fluid or alteration in intra-articular pressure in the joint environment rather than changes in disc position (28). after prp application, the flow of chemical mediators to the microenvironment of the joint area via the gfs that derived from the alpha granule (29). also prp has an inflammatory modulating capability by eliminating pain inducers and providing a micro environmental repair of disc, capsule and retrodiscal pad; which may produce a symptomatic relief of pain in prp-injected patients (29). pietrzak and eppley (30) stated that increased concentration of gfs which simulate the initial stage of the inflammatory response by the migration of j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 48 neutrophils, monocytes and macrophages to the site of injury (30). furthermore, the cytokines and mediators may mediate the initiation of neovascularization, fibroblast proliferation and further recruitment of inflammatory cells (30). in addition to the stimulatory effects of prp on reparative cells, the local delivery of prp may have an inhibitory effect on specific proinflammatory cytokines, such as suppression of interleukin-1 that is released from the activated macrophages (31). this dual action may improve the repair and reduce the tissue breakdown and may also permit the acceleration of tissue healing process and provide potential benefits for better outcomes and faster recovery (32). tmj clicking in this study, the high success rate of tmj sound reduction is in line with a study performed by hanci et al. (21) who reported a significant reduction in joint sound after intra-articular injection of prp in 20 patients out of 32 patients aged 26 years. according to anitua et al. (33), intra-articular administration of prp may improve joint lubrication. growth factors that are secreted from prp may modulate synovial cell biology and increase secretion of hyaluronic acid (33), which is the most important component of synovial fluid (34), and supply all the rheological properties of the fluid (35). hyaluronic acid have a multiple function, in addition of being a moisturizer agent for cartilage protection, it is also considered as space filler (35) and it acts as scavenger which inhibits the phagocytosis and chemotaxis; thus aid to preserve the joint integrity (36). several in vitro studies conducted by nitzan et al. (37) suggested that hyaluronic acid seems to have an indirect role in the boundary mechanism which is one of the lubrication mechanism within the tmj (38). surface-active phospholipid (sapl) has an essential role in this mechanism, it serves to reduce wear and the friction of the articular surface (39). under excessive joint loading the boundary mechanism adapts continuously by remolding process, as a result of this process a phospholipasea2 (pla2) will be produced into the synovial fluid (40) it is responsible about lysis surface-active phospholipids. ntiza et al. (37) clarify the role of ha in protection the surface-active phospholipids by inhibit action of phospholipasea2. mouth opening in this study, mouth opening was measured at 1st presentation, one and two months following prp therapy. there is a remarkable increase in the mouth opening of patients treated with prp intrerarticular injection one and two months after the treatment. this observation is in line with a study conducted by lippross et al. (41) who found that prp therapy reduces the level of all markers of inflammation and may help to maintain the integrity of the chondral surface and thereby facilitates the joint movement. since normal tmj movement is mainly depending on the disc freely sliding down over the articular surface of the condyle and the slope of the eminence, which is covered with articular cartilage (42). chondrocytes are the only cells that found in the articular cartilage, producing and maintaining the cartilage matrix (43). this matrix is mainly collagen and protglycan which is important to reduce the friction, with consideration of the lubrication system so any aberrations in this system may contribute in tmj dysfunction (42). this observation is more likely reflective of the transforming growth factor (tgf-b) function, which is one of the most important factor involved in the process of cartilage regeneration including the increase in chondrocyte proliferation and matrix molecules production (44). according to several previous studies, prp promoted chondrocyte proliferation rate and may inhibit chondrogenic markers expression (45; 46; 47; 48). this may support the current study findings of mouth opening improvement. also, prp can stimulate an increase in matrix molecule production which play a significant role in maintaining cartilage homoeostasis. this is consistent with a study conducted by akeda et al. (49) who documented that prp treatment may lead to higher amount of matrix. synovial fluid through its component of hyaluronic acid and lubricin is responsible for lubrication of the tmj (34). it protects the articular cartilage from the erosion and protein deposition (50). ppr injection therapy may stimulate synoviocytes and increase the production of the hyaluronic acid (37). considering prp preparation, previous study done by slichter and harker (51) showed that double centrifugation method 1000×g for 9 minutes for the first step and 3000×g for 20 minutes for the second step resulted with decrease in platelets viability. other study performed by dugrillon et al. (52) showed that prp quality is more essential than platelet concentration and the number of platelet is j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 49 not always related to the gfs quantity. they also reported that transforming growth factor and platelet concentration is proportionally related to the force of centrifugation. mazzocca et al. (2012) studied three protocols for prp preparation; the first one used a single spin at 180×g (1500 rpm) for 5 min resulting with a low platelets and wbcs concentration. the second protocol was also single spin at 540×g (3200 rpm) for 15 min, resulting with a high concentration of both platelets and wbcs. the third protocol was done using double step of centrifugation 180×g (1500 rpm) for 5 min and 6300 rpm for 20 min, this produced a high concentration of platelets with lower wbcs.they proved that platelet concentration in second protocol was significantly higher than the other procedures. according to marx (53), the therapeutic level of platelet concentration in prp preparation must be 1,000,000/ ml. in the current study, prp injection was prepared according to mazzocca protocol which include 15 min centrifugation at 540×g (3200 rpm). this protocol has been used due to the high concentrated number of platelets which full the criterion of the therapeutic application. this study is also agree with the study of dugrillon et al. (52) who found that the centrifugal force must be less than 800×g to preserve the platelet viability, taking in consideration the shorter period of time in preparation to prevent changes in platelet morphology and degranulation of growth factors (54). so, the reason behind choosing a single and short time for centrifugation is to have a better quality rather than better quantity of platelets in preparation of prp therapy injection. kon et al. (55) used two different prp preparation, high concentrated number of platelet with wbcs versus high concentrated number of platelet and low number of wbcs. to compare between their effect on 144 patients, who were evaluated up to 12 months; comparable results were obtained with both groups, with the only difference that prp leukocyte group suffered from more swelling and sever pain reaction after the injection immediately. in the current study, no complications were recorded after the prp injection immediately. thus, it is different from the fore mentioned study. conclusion: this study support the useful therapeutic effect of prp as an intra-articular injection in the treatment of patients with addcwr. it has the ability to improve functional outcome by reducing pain, clicking and increase range of mouth opening. references: 1. scully, crispian oral and maxillofacial medicine: the basis of diagnosis and treatment (2nd ed.). edinburgh: churchill livingstone 2008. 2. sommer oj. cross –sectional and functional imaging of the tempromandibular joint: radiology, pathology, and basic biomechanics of the jaw .radio graphic online 2003; 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8, 1–30. 41. lippross s, moeller b, haas h, tohidenezhad m, steubesand n, wruck c etal. intra-articular injection of platelet-rich plasma reduces inflammation in a pig model of reumatodied arithrities of the knee joint.arithrites rheum, 2011; 63(11): 3344-3353. http://www.ncbi.nlm.nih.gov/pubmed/25491276 http://www.ncbi.nlm.nih.gov/pubmed/25491276 http://www.ncbi.nlm.nih.gov/pubmed/25491276 j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 51 42. hegab, a. temporomandibular joint internal derangement. dent health oral disord ther 2015; 2(1), 00033. 43. lee hr, park km, joung yk, park kd, do sh. platelet-rich plasma loaded hydrogel scaffold enhances chondrogenic differentiation and maturation with up-regulation of cb1 and cb2. j control release 2012; 159(3), 332–337. 44. filardo g, vannini f, marcacci m, andriolo l, ferruzzi a, giannini s, kon e. matrix-assisted autologous chondrocyte transplantation for cartilage regeneration in osteoarthritic knees: results and failures at midterm follow-up. am j sports med 2013; 41(1), 95–100. 45. yang sy, ahn st, rhie jw, lee ky, choi jh, lee bj, oh gt. platelet supernatant promotes proliferation of auricular chondrocytes and formation of chondrocyte mass. ann plast surg 2000; 44(4), 405–411. 46. kaps c, loch a, haisch a, smolian h, burmester gr, häupl t, sittinger m. human platelet supernatant promotes proliferation but not differentiation of articular chondrocytes. med biol eng comput 2002; 40(4), 485–490. 47. gaissmaier c, fritz j, krackhardt t, flesch i, aicher wk, ashammakhi n. effect of human platelet supernatant on proliferation and matrix synthesis of human articular chondrocytes in monolayer and three-dimensional alginate cultures. biomaterials 2005; 26(14), 1953–1960. 48. drengk a, zapf a, stürmer ek, stürmer km, frosch kh. influence of platelet-rich plasma on chondrogenic differentiation and proliferation of chondrocytes and mesenchymal stem cells. cells tissues organs 2009; 189(5), 317–326. 49. akeda k, an hs, okuma m, attawia m, miyamoto k, thonar ej, lenz me, sah rl, masuda k. plateletrich plasma stimulates porcine articular chondrocyte proliferation and matrix biosynthesis.osteoarthritis cartil 2006;14(12),1272–1280. 50. rhee dk, marcelino j, baker m, gong y, smits p, et al. the secreted glycoprotein lubricin protects cartilage surfaces and inhibits synovial cell overgrowth. j clin invest 2005; 115,622–631. 51. slichter sj, harker la. preparation and storage of platelet concentrates. i. factors influencing the harvest of viable platelets from whole blood. br j haematol 1976; 34,395–402. 52. dugrillon a, eichler h, kern s, klüter h. autologous concentrated platelet-rich plasma (cprp) for local application in bone regeneration. int j oral maxillofac surg 2002; 31,615–9. 53. marx re:platelet-rich plasma: evidence to support its use. j oral maxillofac surg, 2004; 62,498-93. 54. nagata mj, messora mr, furlaneto fa, et al. effectiveness of two methods for preparation of autologous platelet-rich plasma: an experimental study in rabbits. eur j dent 2010; 4,395-402. 55. kon e, mandelbaum b, buda r, filardo g, delcogliano m, timoncini a, fornasari pm, giannini s, marcacci m. platelet-rich plasma intraarticular injection versus hyaluronic acid viscosupplementation as treatments for cartilage pathology: from early degeneration to osteoarthritis. arthroscopy 2011; 27, 1490–1501. في الدموية داخل المفصل الفكي الصدغي الصفيحاتبالبالزما الغنية حقن فعالية مع الرجوعاألمام الى القرص نزوح من المرضى الذين يعانون الخالصة في تدريجيخلل . وهوبات الداخلية شيوعا للمفصل الفكي الصدغياطرضمن اكثر اال هو القرص الى االمام مع الرجوعحركة خلفية: والحفرة خالل غلق الفك قمةلبالم في المفصل واصوات فرقعة مفصلية بسب حركة القرص فيما يتعلق بال يتميز سريريا وظيفة المفصل لمعتدلة،ولكن اذا كانت غير فعالة يمكن استخدام الحقن بمادة البالزما الغنية بالصفيحات الدموية ان تستخدم تقنية العالج ا . يمكنالسفلي عاليتركيز يتميزهو نتاج ذاتي طبيعي الدموية البالزما الغنية بالصفيحات داخل المفصل والتي تعتبر طريقة اقل من التداخل االجراحي. عوامل النمو مجموعة من من خالل موضعيا عملية الطرد المركزي لتعزيز شفاء األنسجةبعليها يتم الحصول الدموية التي من الصفيحات وتستخدم هذه التقنية اليوم بشكل متزايد باعتبارها .وتطلق هذه العوامل عبر عملية التحبب بعد تفعيل الذاتي. الموجودة في حبيبات الفا طريقة بسيطة وامنة. الصدغي للمرضى الذين يعانون من يفعالية الحقن بمادة البالزما الغنية بالصفيحات الدموية داخل المفصل الفك لتقييم الهدف من الدراسة : الى االمام مع الرجوع. حركة القرص من 41من االناث و 14كانوا يعانون من حركة القرص الى االمام مع الرجوع، مريض 06شملت الدراسة مشاركة المواد وطرائق العمل: مريض والذي سبق ان تم عالجهم بالتقنيات 06( سنة. تم تقسيمهم الى مجموعيتن االولى المكونة من 06-06ذكور تتراوح اعمارهم بين )ال تكون المعتدلة بدون اي استجابة فتم حقنهم بالصفيحات الدموية الغنية بالبالزما والذي تم اعتبارهم مجموعة الدراسة اماالمجموعة الثانية فت مريض وتم عالجهم بالتقنيات المعتدلة وتم اعتبارهم المجموعة الضابطة اما طريقة العمل المستخدمة للحقن داخل المفصل 06ن ايضا م مل من تركيز البالزما الغنية من الصفيحات الدموية تم الحصول عليه 4مل من الدم الوريدي للمريض كعينة ، 46كانت تتضمن جمع مركزي. تم تقييم االلم ، فتحة الفم القصوى من دون مساعدة باالضافة الى اصوات الفرقعة في المفصل الفكي بواسطة خطوة واحدة للطرد ال الصدغي سريريا قبل وبعد الشهر االول والثاني من العالج. j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 52 م وجود أي مضاعفات بعد هناك تحسن ثابت في الحد من درجة األلم وأصوات النقر المتبادل و زيادة كبيرة في فتحة الفم . مع عد النتائج: الحقن مباشرة و عند المتابعة. هذه الدراسة تدعم فعالية حقن البالزما الغنية بالصفيحات الدموية داخل المفصل الفكي الصدغي لعالج اضطربات حركة االستنتاجات : وزيادة فتحة الفم والتي بالتالي تحسن وظيفة القرص الى االمام مع الرجوع كونه طريقة امنة لتقليل االلم واصوات الفرقعة المفصلية المفصل. 25. ammar f.doc j bagh college dentistry vol. 27(4), december 2015 nasopharyngeal pedodontics, orthodontics and preventive dentistry 150 nasopharyngeal dimensions in relation to some dentocranial variables in class i and ii skeletal patterns (a comparative cephalometric study) ammar a. fadel, b.d.s. (1) fakhri a. ali, b.d.s, m.sc. (2) abstract background: the size of the nasopharyngeal airway was believed to have an important role in the development of the dentofacial structure. this study was carried out to test the relation between the nasopharyngeal dimensions with some dento-cranial measurements in class i and ii jaw relationship. materials and methods: this study was done on 60 subjects (30 males and 30 females) at age range 18-25 years. cephalometric radiograph has been taken to each subject and the measurements were recorded. the sample was divided into two groups, class i skeletal relationship (15 males and 15 females) and class ii skeletal relationship (15 males and 15 females). comparisons between the different groups were undertaken. results: in class i skeletal relationship, all the nasopharyngeal liner measurements and all the dento-cranium linear measurements are significantly higher in males than females, except lower airway thickness (pns-ad1) and upper airway thickness (pns-ad2) showed no significant gender difference. while all the angular measurements showed no significant gender difference. in class ii skeletal relationship, most of the nasopharyngeal liner measurements have no significant gender difference, while all the dento-cranium linear measurements are significantly higher in males than females. conclusion: in comparison for class difference between class i and class ii skeletal relations in total sample, all the nasopharyngeal linear measurements have no significant class difference, except lower airway thickness showed significant difference which was higher in class ii than class i and upper airway thickness showed significant difference which was higher in class i than class ii. in the whole sample of the study, positive correlation was found between lower airway thickness and upper airway thickness. key words: nasopharyngeal, gender, class i, class ii. (j bagh coll dentistry 2015; 27(4):150-154). introduction the pharyngeal tonsil (adenoid), is a group of lymphoid tissues in nasopharynx that becomes apparent clinically when they undergo hyperplasia(1). tomes (1872) presented the first article describing the adenoid face and believed that this facial type is a product of mouth breathing resulting from enlarged adenoid tissue. from that time there have been many attempts carried out in different parts of the world to establish the causal relationship between the dentofacial deformities and nasal airway inadequacy. it has been suggested that the so called "adenoid faces" is the product of mouth breathing caused by enlarged adenoids (2). on the other hand, a significant number of clinicians and researchers have questioned the assumption that enlarged adenoids influence the dentofacial morphology (3). the causes of mouth breathing are unquestionably multiple but restricted nasopharyngeal airway due to hypertrophy of adenoid tissue and narrow bony nasopharynx has been considered to be the most common cause(4-7). (1) m.sc. student, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. although the causes of mouth breathing has been well clarified but the effects is still a matter of controversy. many researchers agree that mouth breathing and its associated abnormal posture and function of the oral and paraoral structures have serious effects on dentofacial development and has been regarded as an obstacle to success of orthodontic treatment. however, others disagree. this controversy is not only academically important, but it also has considerable clinical consequences because it can influence the orthodontist's decision as to whether active allergy management or a moreaggressive therapy such as adenoidectomy should be performed for solely orthodontic reasons (8). materials and methods the sample consisted of patients attending the orthodontic department of college of dentistrybaghdad university either for active orthodontic treatment or consultation and undergraduate students. out of 97 clinically and radiographically examined subjects, only 60 subjects (30 males and 30 females) were selected according to the inclusion criteria: j bagh college dentistry vol. 27(4), december 2015 nasopharyngeal pedodontics, orthodontics and preventive dentistry 151 1. class i control group (15 males & 15 females): anb 2°4°, bilateral class i molar and canine relationship, normal overjet and overbite (2-4 mm), well aligned upper and lower arches with less than 3mm of spacing or crowding in either of them. 2. class ii group (15 males & 15 females): anb > 4°, bilateral class ii molar and canine relationship, overjet > 4 mm. the sample criteria include: 1. all of the samples were arab iraqis with an age ranged between 18-25 years. 2. no history of previous orthodontic treatment. 3. normal overjet and overbite and no gross facial asymmetry. 4. no oral habits according to the subject history and clinical examination. 5. no history of nasopharyngealectomy procedure. 6. no asthma, upper airway disease and any pathology in the pharynx according to subject’s medical history. 7. the subjects possessed complete permanent dentition (except the third molar). 8. no posterior or anterior cross bite. 9. normal medical history of the subjects. 10. normal tmj function. 11. no open bite posterior or anterior. lateral cephalometric radiographs were taken for the entire sample separately under standardized conditions. after that a software program (autocad 2012) was used for analyzing them. the following anatomical cephalometric bony landmarks were used in the present study (figure 1): 1) point n (nasion): the most anterior point on the fronto-nasal suture in the mid-sagittal plane. 2) point s (sella): the midpoint of the hypophysial fossa (sellaturcica). 3) point ba (basion): the lowest point on the anterior margin of the foramen magnum in the median plane. 4) point a (subspinale): is located at the most posterior part of the anterior shadow of the maxilla, usually near the apex of the central incisor root. 5) point b (supramentale): is located at the most posterior point on the shadow of the anterior border of the mandible, usually near the apex of the central incisor root. 6) point ans (anterior nasal spine):the anterior tip of the bony process of the maxilla. 7) point pns (posterior nasal spine):the posterior tip of the palatine bone. it can be located at the point where the hard palate is intersected by an extension of the pterygomaxillary fissure. 8) point me (menton):the most inferior point on the symphysis of the mandible in the median plane. 9) point go(gonion):the most posterior and inferior point on the angle of the mandible located by bisecting the angle formed by the line tangent to the posterior border of the ramus and inferior border of body of mandible. the following constructed cephalometric points were used in this study (figure 2): 1) point ad1 (adenoid 1): the most anterior point on the adenoid tissue along the line passing from pns-ba. 2) point ad2 (adenoid 2): the most anterior point on the adenoid tissue along the line passing from pns and perpendicular to s-ba line. 3) point j (adenoid 3):the most anterior point on the adenoid tissue along the line passing from du and perpendicular to s-ba at z. 4) point k (adenoid 4): the most anterior point on the adenoid tissue along the line passing from dl and perpendicular to s-ba at y. 5) point du: a constructed point at the junction of distal and occlusal surface of maxillary first permanent molar. 6) point dl: a constructed point at the junction of distal and occlusal surface of mandibular first permanent molar. 7) point h: a constructed point represents intersection of the two lines s-ba and a line perpendicular to it from pns. 8) point z: a constructed point represents intersection of the two lines s-ba and a line perpendicular to it from du. 9) point y: a constructed point represents intersection of the two lines s-ba and a line perpendicular to it from dl. the following measurements were done liner measurements (figure 1): 1) s-n: the distance measured between sella and nasion and represents the anterior cranial base length. 2) s-ba: the distance measured between sella and basion and represents the posterior cranial base length. 3) n-ba: the distance measured between nasion and basion and represents the total cranial base length. j bagh college dentistry vol. 27(4), december 2015 nasopharyngeal pedodontics, orthodontics and preventive dentistry 152 4) mandibular plane (mp): it is a line tangent to the lower border of the mandible, extends from gonion to menton. 5) ans-pns {palatal plane (pp)}: a line connecting the tip of the anterior nasal spine with the tip of the posterior nasal spine and represent the length of the maxilla. 6) n-ans: a line connecting the tip of the anterior nasal spine with nasion and represent the upper anterior facial height. 7) ans-me: a line connecting the tip of the anterior nasal spine with menton and represent the lower anterior facial height. 8) n-me: a line connecting nasion and menton and represent the total anterior facial height. 9) pns-ad1 (lower airway thickness): the distance measured between pns and ad1 and represents the sagittal depth of the nasopharyngeal airway along the line pns-ba. 10) pns-ad2 (upper airway thickness): the distance measured between pns and ad2 and represents the sagittal depth of the nasopharyngeal airway along the line pns-ba. 11) ad1-ba (lower adenoid thickness): the distance measured between ad1 and ba. 12) ad2-h (upper adenoid thickness): the distance measured between ad2-h. 13) du-j: represent the distance from the junction of distal and occlusal surface of maxillary first permanent molar to the most anterior point on the adenoid tissue along the line passing from du and perpendicular to s-ba. 14) j-z (middle adenoid thickness): the distance measured from the most anterior point on the adenoid tissue along the line passing from du and perpendicular to s-ba at z. 15) dl-k: represent the distance from the junction of distal and occlusal surface of mandibular first permanent molar to the most anterior point on the adenoid tissue along the line passing from dl and perpendicular to s-ba. 16) k-y (middle adenoid thickness): the distance measured from the most anterior point on the adenoid tissue along the line passing from dl and perpendicular to s-ba at y. 17) upper 6 ╧ pp: a line connecting the junction of distal and occlusal surface of maxillary first permanent molar and palatal plane which is perpendicular to it. 18) lower 6 ╧ mp: a line connecting the junction of distal and occlusal surface of mandibular first permanent molar and mandibular plane which is perpendicular to it. angular measurements (figure 3): 1) sna: represents the antero-posterior position of the maxilla in relation to the anterior cranial base. 2) snb: represents the antero-posterior position of the mandible in relation to the anterior cranial base. 3) anb: difference between sna and snb and represents the antero-posterior relation of the maxilla and mandible to each other. 4) n-s-ba: the angle between the anterior and the posterior cranial base (anterior rim of foramen magnum). 5) sn/mp: the angle between the sn plane and the mandibular plane. 6) sn/pp: the angle between the sn plane and the palatal plane. figure (1): cephalometric landmarks and liner measurements. figure 2: constructed points j bagh college dentistry vol. 27(4), december 2015 nasopharyngeal pedodontics, orthodontics and preventive dentistry 153 figure (3): angular measurements statistical analysis all the data were subjected to computerized statistical analysis by using descriptive statistics including mean, standard deviation, minimum and maximum and by using inferential statistics including independent sample t-test and pearson correlation test. results the results show that in class i skeletal relationship, all the nasopharyngeal liner measurements and all the dento-cranium linear measurements are significantly higher in males than females, except (pns-ad1 and pns-ad2) showed no significant gender difference and all the angular measurements showed no significant gender difference. while in class ii skeletal relationship, all the dento-cranium linear measurements are significantly higher in males than females, and all the nasopharyngeal liner measurements have no significant gender difference except k-y.in comparison for class differences between class i and class ii skeletal relations for males group, all the nasopharyngeal liner measurements are significantly higher in class i than class ii, except pns-ad1which were higher in class ii than class i and (ad2-h and duj) have no significant class difference. in comparison for class differences between class i and class ii skeletal relations for females group, all the angular measurements showed no significant class difference, except snbº showed significant class difference which was higher in class i than class ii and anbº which were higher in class ii than class i. in comparison for class differences between class i and class ii skeletal relations for total sample, all the nasopharyngeal liner measurements and all the dento-cranium linear measurements showed no significant class difference, except (pns-ad1, ans-me and du i pp) showed significant class difference which were higher in class ii than class i and (pns-ad2 and n-ans) showed significant class difference which were higher in class i than class ii. additionally, positive correlation found between pns-ad1 and pns-ad2 and between du-j and dl-k in total sample. discussion nasal breathing is a physiological function responsible for the process of air conditioning, warming, humidification and filtering, it also serves as protection for respiratory tract. moreover it has effects on development and determination of dentofacial morphology. adenotonsiller hypertrophy causes upper airway obstruction and may lead to pulmonary alveolar hypoventilation, pulmonary hypertension, symptoms like chronic mouth breathing, loud snoring, obstructive sleep apneas, excessive daytime sleepiness. in this situation, a number of postural changes, such as open mandible posture, downward and forward positioning of the tongue, and extension of the head, can take place. oral respiration alters the muscle forces exerted by the tongue, cheeks, and lips upon the maxillary arch. intraorally, it might be expected to find a narrow maxillary arch with a high palatal vault, a posterior crossbite, a class ii or iii dental malocclusion, and an anterior open bite. that is why this study targeted two types of skeletal jaw relationships (class i and class ii skeletal patterns) and it’s aimed to investigate the difference in their nasopharyngeal dimensions and gender difference. the sample selected in this study was composed of cephalometric radiographs of young adults 18-25 years of age because most of the growth of the dento-cranium bones could be considered as complete after the age 18 years (9) and the members of this age group are often under orthodontic treatment. the identification of cephalometric points, angular and liner measurements where done directly on a digital radiograph by using a computer with modern analyzing software in an effort to enhance the reliability of the measurements and to reduce tracing and measuring errors. in class i skeletal relationship, all the nasopharyngeal liner measurements are significantly higher in males than females, except (pns-ad1 and pns-ad2) showed no significant gender difference and this was in agreement with previous studies (10,11) regarding the pns-ad1 and j bagh college dentistry vol. 27(4), december 2015 nasopharyngeal pedodontics, orthodontics and preventive dentistry 154 pns-ad2.while in class ii skeletal relationship, all the nasopharyngeal liner measurements have no significant gender difference except k-yand this was in agreement with previous studies (12,13) regarding ad1-ba, pns-ad1 and pns-ad2 although their method were different {they use ptm (pterygomaxillary fissure) instead of pns to measure ad1 and ad2}. in general, the linear measurements were found larger in males than females and this indicated that the males have larger head than females and can be attributed to the fact that the maximum growth rate of females is reached two years earlier than males (14) and this was also in agreement with previous studies (15-20). the reason why the angular measurements were not significantly different between genders in contrast to the linear measurements was because the angular measurements usually refer to the direction of growth rather than to increase or decrease in the size. additionally, the angular measurements were influenced by the geometrical factors. in the present study, we can conclude that all the nasopharyngeal linear measurements have no significant class difference, except (pns-ad1) showed significant difference which was higher in class ii than class i and (pns-ad2) showed significant difference which was higher in class i than class ii. moreover; positive correlation was found between pns-ad1 and pns-ad2 and between du-j and dl-k. references 1. handelman cs, osborne g. growth of the nasopharynx and adenoid development from one to eighteen years. angle orthod 1976; 46: 243-59. 2. linder-aronson s. respiratory function in relation to facial morphology and the dentition. br j orthod 1979; 6:59-71. 3. watson rm, warren dw, fischer nd. nasal resistance, skeletal classification and mouth breathing in orthodontic patients. am j orthod 1968; 54:367-79. 4. subtelny id. the significance of adenoid tissue in orthodontics. angle orthod 1954; 24: 59-69. 5. ricketts rm. respiratory obstruction syndrome. am j orthod 1968; 54: 495-514. 6. linder-aronson s. adenoids, their effect on mode of breathing and nasal airflow and their relationship characteristics of facial skeleton and dentition. acta otolaryng suppl 1970; 265: 1-132. 7. preston cb. preliterate environment and the nasopharynx.am j orthod 1979; 76: 646-56. 8. tourne lp. growth of the pharynx and its physiologic implications. am j orthod 1991; 99: 129-39. 9. graber tm. orthodontics principles and practice. philadelphia: w.b. saunders company; 1988. 10. martin o, muelas l, josé m. nasopharyngeal cephalometric study of ideal occlusions. am j orthod dentofac orthop 2006; 130(4): 436.e1-9. 11. al-sayagh nm. a cephalometric comparison of pharynx and soft palate in iraqi adolescents and adults population. al-rafid dent j 2012; 12(1): 3242. 12. al–saleem nr. evaluation of the pharyngeal size in skeletal class i and class ii subjects diseases. alrafid dent j 2007; 7(spiss): 45s-53s. 13. ali fa, al-ani r, al-khatieeb m. a cephalometric comparative study of pharyngeal sagittal dimension in different skeletal patterns. j bagh coll dentistry 2011; 23(1):100-6. 14. proffit wr, fields hw, sarver dm. contemporary orthodontics. 4th ed. st. louis: mosby harcourt health sciences company; 2007. 15. mossa aa. orientation of the cranial base on facial skeleton in different skeletal classes of iraqi adults.a master thesis, orthodontic department, baghdad university, 2007. 16. al-hamdany akh. the effect of basicranial flexure on facial divergence of iraqi adults (18-25 years) in mosul city. al-rafid dent j 2002; 2(2): 24963. 17. johannsdottir b, thordarson a, magnusson te. craniofacial skeletal and soft tissue morphology in iceland adults. eur j orthod 2004; 26(3): 245-50. 18. moldez ma, koshi s, junji sj, mitani h. linear and angular filipino cephalometric norms according to age and sex. angle orthod 2006; 76(5): 800-05. 19. yassir ya. the relation of anterior and lateral cranial base lengths with mandibular morphology and facial heights. j. bagh. coll. dentistry 2008; 20(2): 88-92. 20. abd bi. cranial base morphology in different skeletal classes (a cross-sectional lateral cephalometric study). a master thesis, orthodontic department, baghdad university, 2012. 26. nibras f.doc j bagh college dentistry vol. 25(1), march 2013 force decay of orthodontics, pedodontics and preventive dentistry159 force decay of orthodontic elastomeric chains by using three different mechanisms simulating canine retraction nibras j. mohammed, b.d.s. (1) mushriq f. al-janabi, b.d.s., m.sc. (2) abstract background: the ideal force-delivery system must: provide optimal tooth moving forces that elicit the desired effects, be comfortable and hygienic for the patient, require minimal operator manipulation and patient cooperation and provide rapid tooth movement with minimal mobility during orthodontic therapy, the elastomeric chains have the greatest potential to fulfill these requirements. materials and methods: this in vitro study was designed to determine the effect of three different mechanisms for canine retraction : (6-3 , 6-5-3 and chain loop ) on the load relaxation behavior of three types of elastomeric chains : (maximum clear , maximum silver and extreme silver) from the same company (ortho technology company) with two different brand configurations: closed loop and open (short filament) chains under effect of time at (zero time, 24hr., 7, 14 , 21 and 28 days) in artificial saliva. results: statistical analysis showed that there was a highly significant difference in the mean percentage force decay for the three different mechanisms (p≤ 0.001).for all the three types, the 6-3 mechanism had the smallest mean percentage force decay. there was a highly significant difference in the mean percentage force decay for the different types (p≤ 0.001). for all three mechanisms, extreme silver elastomeric chains had the smallest percentage force decay while maximum silver elastomeric chains had the highest percentage force decay. conclusion: this study illustrated that for all the three types of elastomeric chains, the (6-3) mechanism had the smallest mean percentage force decay. this finding suggests that it may be most efficient to retract a canine utilizing elastomeric chain directly from the molar hook to the canine bracket. the chain loop mechanism may not be indicated for space closure in vivo due to the excessive physiological force values involved with this mechanism. key words: force decay of orthodontic elastomeric chains by using three different echanisms simulating canine retraction. (j bagh coll dentistry 2013; 25(1):159-163). introduction orthodontic elastomeric chains are polyurethanes, thermosetting polymer products of a step-reaction polymerization process .they were fabricated either by die cut stamping or injection molding and could be poly (ether) urethane or poly (ester) urethane (1, 2). elastomeric chains were introduced to the dental profession in the 1960s and have since been used extensively in orthodontic for canine retraction, closing diastemas, correcting rotations shifting midlines, and in achieving general space closure. elastomeric chains have the advantages of being inexpensive, easily applied and requiring little patient cooperation; however, a disadvantage is that when exposed to the oral environment, they absorb saliva, permanently stained and become permanently deformed due to a breakdown of internal bonds (3, 4). one of the major short coming of the elastomeric chains was their inability to maintain delivered force for a significant duration, therefore after placement the elastic chains were to be changed at 3-4 weeks intervals (5, 6). (1) m.sc. student, dep. of orthodontics, college of dentistry, university of baghdad. (2) assistant professor, dep. of orthodontics, college of dentistry, university of baghdad. since there was usually a relaxation of more than half of the force in the first 24 hour, followed by a gradual additional decline over a 3-weeks period accordingly, an initial force heavier than desired would have to be used if one were to offset the initial relaxation and produce adequate force to move the teeth. therefore, elastic chains' forces decay rapidly and so could be characterized better as interrupted rather than continuous (7, 8). this was to be due to a combination of water that causing the weakening of intermolecular force with the chemical degradation, and tooth movement resulting in decreasing stretch upon the elastomeric chain (9, 10). numerous past studies have evaluated the force decay of elastomeric chain materials, at the time of these study rare published studies were found that evaluated the force decay of elastomeric chains as related to the mechanical design employed in canine retraction. therefore, the objectives of this study were twofold. first, to evaluate the percentage force decay of elastomeric chain products utilizing three different mechanical designs simulating canine retraction. second, to evaluate the percentage force decay of three types of elastomeric chain products from the same company. j bagh college dentistry vol. 25(1), march 2013 force decay of orthodontics, pedodontics and preventive dentistry160 materials and methods three types of elastomeric chains were selected from ortho technology company: 1. maximum™ elastomeric chains clear in color which were subdivided into: closed and short. 2. maximum™ elastomeric chains metallic silver in color which were subdivided into: closed and short. 3. extreme™ elastomeric chains metallic silver in color which were subdivided into: closed and short. three rectangular acrylic resin jigs of 25x10x1 (cm) of length measurements, were constructed to provide a framework for the three mechanisms simulating canine retraction. each jig was made of two separated halves of acrylic. on both ends of each jig , a hyrax rapid palatal expander (dentarum company / germany) was embedded into the acrylic. the acrylic jigs were set up so that three different mechanical designs for canine retraction could be studied. the designs were as follows: mechanism one: 6-5-3 – simulated elastomeric chain stretching from the first molar hook, attaching to the second premolar hook and attaching to the canine hook. (figure 1). figure 1: mechanism one (6-5-3). mechanism two: chain loop – simulated elastomeric chain stretching from the first molar hook, looping around the canine hook and attaching back to the molar hook. (figure 2). figure 2: mechanism two (chain loop). mechanism three: 6-3 – simulated elastomeric chain stretching from the first molar hook, attaching to the canine hook. (figure 3). figure 3: mechanism three (6-3). the 6-5-3 acrylic jig (figure 1) consisted of 25 triplets of dental screws (nordin company / switzerland) were embedded in the acrylic. the two most lateral dental screws were spaced 29 mm from each other to act as the midpoint of the first molar tube and the midpoint of the canine bracket for attachment of the elastomeric chains. (11). the middle screws were representative of second premolars hooks. the distance between the middle screws and the screws that representing the first molar hooks was 8 mm, while the remaining 21 mm represent the distance between the second premolar hook and the canine hook (12). for both mechanism two (chain loop) and mechanism three (6-3) (figures 2, 3), 25 pairs of dental screws were symmetrically aligned in rows in the separated halves of the acrylic resin jigs, they were spaced 29 mm. three hundred sixty specimens were tested for load relaxation. elastomeric chains with an initial length (19mm) and about 50% extension (29mm) were used for the (6-3) and (6-5-3) mechanisms throughout the study, while for the (chain loop) mechanism the elastomeric chains used were with an initial length (38 mm) and about 50% extension (58 mm). throughout the study, the three jigs and the attached elastomeric chains were maintained in an artificial salivary solution and stored in an incubator at a constant temperature of 37ºc to simulate oral conditions. an electronic force gauge was constructed with an action resembles the instron device. two hooks made of 1 mm stainless steel wire which was sufficiently stiff to exclude any absorption during testing, one hook was attached to the movable end of the load cell which represents the canine tooth, and the other one was soldered to a vertical stud at 29 mm space which represents the first molar tooth. (11). figure(4). j bagh college dentistry vol. 25(1), march 2013 force decay of orthodontics, pedodontics and preventive dentistry161 figure 4: force gauge. all the elastomeric chains were measured for their force by the measuring device by stretching the specimens between the two hooks of the force gauge for (6-5-3) and (6-3) mechanisms. for (chain loop) mechanism it was done by attaching one end of the specimen to one hook of the force gauge looping around the other hook and attaching back to the first hook. statistical analysis data collected analyzed by using relevant soft ware statistical package of social science (spss, chicago, 111). these data of the delivered forces for all specimens were averaged, and the results were analyzed with the following statistics: 1. descriptive statistics :( mean of load, mean of the percentage of force decay and their standard deviation). 2. inferential statistics: (t-test, anovatest and lsdtest). results different types of the elastomeric chains had different mean load and percentage of force decay over time. (tables 1, 2). the statistical analysis indicated that there was a significant interaction between type and mechanism(p= 0.000); therefore, the effect of type on percentage force decay over time must be examined separately for each mechanism and the effect of mechanism on percentage force decay over time must be examined separately for each type . (table 3). differences between different types of elastomeric chains a hsd was found in the mean percentage force decay for the different types (p = 0,000). for all three mechanisms, extreme silver had the smallest percentage force decay, maximum clear had the highest initial force values and the maximum silver had the largest percentage force decay. table (3). differences between different mechanisms of canine retraction there was a hsd in the mean percentage force decay for the different mechanisms (p = 0.000). for all types, the (6-3) mechanism had the smallest mean percentage force decay followed by the (chain loop) mechanism, while the (6-5-3) mechanism had the largest percentage force decay. table (3). table 1: descriptive data of the mean load (gm) of the elastomeric chains at different test periods and mechanisms. d ay s type mechanism 6-3 6-5-3 chain loop mean s.d. mean s.d. mean s.d. 0 maximum clear short 341.07 10.9 339.17 12.2 481.41 3.60 closed 129.84 7.06 365.86 10.5 493.70 4.19 maximum silver short 269.51 8.11 268.35 8.39 464.56 4.88 closed 285.93 7.33 284.21 7.38 475.36 3.41 extreme silver short 214.51 10.9 214.85 11.0 432.47 4.92 closed 248.40 6.67 246.11 7.36 449.23 4.45 1 maximum clear short 104.89 8.04 105.48 5.00 210.23 9.21 closed 132.63 7.04 122.50 9.37 205.14 7.97 maximum silver short 110.72 11.0 98.80 5.17 222.65 8.70 closed 130.58 5.25 111.33 5.74 238.25 6.59 extreme silver short 151.68 4.41 102.53 6.36 238.10 7.40 closed 179.09 5.36 139.24 5.00 264.66 9.74 7 maximum clear short 104.89 8.04 80.12 5.69 170.23 9.21 closed 132.63 7.04 93.75 7.31 173.64 9.01 maximum silver short 81.32 11.3 67.10 4.72 165.15 9.08 closed 110.88 6.23 81.33 5.74 180.25 7.12 extreme silver short 135.48 9.18 82.53 6.36 196.10 7.28 closed 169.59 5.52 119.24 5.00 224.66 9.74 14 maximum clear short 95.64 8.05 74.88 5.82 150.63 12.6 closed 120.13 7.44 88.75 7.65 161.64 9.48 maximum silver short 73.67 11.4 62.10 5.02 143.65 9.54 closed 103.23 6.03 75.43 5.26 159.80 7.01 extreme silver short 125.48 9.18 73.68 6.81 186.10 7.28 closed 149.59 5.52 108.74 4.72 214.66 9.74 21 maximum clear short 92.64 7.91 71.33 7.71 140.13 12.6 closed 117.02 7.25 83.75 7.74 151.14 10.3 maximum silver short 70.57 11.4 57.40 5.24 133.65 9.54 closed 99.93 5.82 70.13 6.02 150.30 7.80 extreme silver short 122.28 8.97 69.33 7.28 176.10 7.28 closed 145.39 6.14 103.29 4.65 204.66 9.74 28 maximum clear short 90.59 7.98 68.13 7.82 134.48 12.7 closed 114.22 7.24 81.55 7.36 145.28 10.7 maximum silver short 68.03 11.2 54.50 5.52 126.75 8.17 closed 97.58 6.03 67.33 6.37 143.35 9.50 extreme silver short 120.05 8.82 66.78 8.39 169.85 9.03 closed 141.64 7.15 99.94 4.69 198.95 11.4 j bagh college dentistry vol. 25(1), march 2013 force decay of orthodontics, pedodontics and preventive dentistry162 table 2: descriptive data of the percentage of force decay of the elastomeric chains at different test periods and mechanisms d ay s type mechanism 6-3 6-5-3 chain loop mean s.d. mean s.d. mean s.d. 0 maximum clear short 0 0 0 closed 0 0 0 maximum silver short 0 0 0 closed 0 0 0 extreme silver short 0 0 0 closed 0 0 0 1 maximum clear short 61.89 2.40 68.89 1.25 56.33 1.89 closed 58.44 2.32 66.47 2.93 58.45 1.58 maximum silver short 58.88 4.29 63.16 2.08 52.07 1.95 closed 54.31 1.91 60.81 2.13 49.88 1.30 extreme silver short 29.11 4.20 52.13 4.22 44.94 1.80 closed 27.86 2.81 43.39 2.22 41.09 2.10 7 maximum clear short 69.21 2.61 76.36 1.74 64.64 1.89 closed 63.84 2.33 74.36 2.03 64.83 1.85 maximum silver short 69.81 4.29 74.97 1.97 64.44 2.04 closed 61.21 2.13 71.37 2.05 62.08 1.48 extreme silver short 36.68 5.40 61.46 3.89 54.65 1.79 closed 31.69 2.60 51.53 2.11 49.99 2.10 14 maximum clear short 71.92 2.59 77.90 1.83 68.71 2.63 closed 67.24 2.38 75.73 2.12 67.25 2.01 maximum silver short 72.65 4.30 76.83 2.12 69.07 2.14 closed 63.88 2.19 73.45 1.83 66.38 1.48 extreme silver short 41.36 5.26 65.60 3.84 56.96 1.79 closed 39.75 2.49 55.80 1.82 52.22 2.10 21 maximum clear short 72.81 2.52 78.94 2.42 70.89 2.62 closed 68.09 2.31 77.10 2.14 69.38 2.16 maximum silver short 73.80 4.28 78.58 2.20 71.22 2.14 closed 65.04 2.12 75.32 2.06 68.38 1.68 extreme silver short 42.85 5.22 67.63 3.93 59.27 1.78 closed 41.44 2.68 58.02 1.73 54.44 2.10 28 maximum clear short 73.41 2.53 79.88 2.44 72.07 2.64 closed 68.86 2.27 77.70 2.02 70.57 2.24 maximum silver short 74.75 4.18 79.66 2.29 72.71 1.76 closed 65.86 2.14 76.31 2.19 69.84 2.04 extreme silver short 43.89 5.16 68.81 4.47 60.72 2.13 closed 42.95 3.17 59.38 1.78 55.72 2.45 discussion effect of different types examination of table (2) reveals that the extreme elastomeric chains has the least percent of force decay at the three mechanisms of canine retraction which is ranged between (27.86 % 52.13 % ) at the 1st day and remain having the smallest percent of force decay at the 28th day which ranged between (42.95%-68.81%) this finding proved the claim that the extreme elastomeric chains offer superior rebound qualities with less deformation over an extended period of time when compared to regular chains (13). effect of different mechanisms examination of table (1) shows a range of initial forces (214.51–493.70 gm) in all three mechanisms. the (chain loop) mechanism always table 3: differences in mean percent force decay at each time interval of elastomeric chains between mechanisms. d ay s type mechanism difference anova test lsd test ftest p-value 6-3 6-3 6-5-3 6-5-3 chain loop chain loop 0 maximum clear short closed maximum silver short closed extreme silver short closed 1 maximum clear short 218.54 0.000 0.000 0.000 0.000 closed 78.24 0.000 0.000 0.99 0.000 maximum silver short 70.58 0.000 0.000 0.000 0.000 closed 183.32 0.000 0.000 0.000 0.000 extreme silver short 214.74 0.000 0.000 0.000 0.000 closed 244.84 0.000 0.000 0.000 0.004 7 maximum clear short 155.83 0.000 0.000 0.000 0.000 closed 156.12 0.000 0.000 0.14 0.000 maximum silver short 62.87 0.000 0.000 0.000 0.000 closed 173.48 0.000 0.000 0.16 0.000 extreme silver short 206.99 0.000 0.000 0.000 0.000 closed 467.14 0.000 0.000 0.000 0.038 14 maximum clear short 76.91 0.000 0.000 0.000 0.000 closed 101.44 0.000 0.000 0.99 0.000 maximum silver short 32.82 0.000 0.000 0.000 0.000 closed 143.31 0.000 0.000 0.000 0.000 extreme silver short 198.82 0.000 0.000 0.000 0.000 closed 305.35 0.000 0.000 0.000 0.000 21 maximum clear short 55.57 0.000 0.000 0.020 0.000 closed 97.54 0.000 0.000 0.069 0.000 maximum silver short 30.09 0.000 0.000 0.01 0.000 closed 143.25 0.000 0.000 0.000 0.000 extreme silver short 208.02 0.000 0.000 0.000 0.000 closed 313.18 0.000 0.000 0.000 0.000 28 maximum clear short 54.28 0.000 0.000 0.1 0.000 closed 92.66 0.000 0.000 0.016 0.000 maximum silver short 29.62 0.000 0.000 0.032 0.000 closed 123.37 0.000 0.000 0.000 0.000 extreme silver short 189.57 0.000 0.000 0.000 0.000 closed 232.75 0.000 0.000 0.000 0.000 produced the highest initial force values (432.47– 493.70 gm).the three mechanisms had varying mean percentage force decay values depending on the different types of elastomeric chains involved. examination of table 2 reveals that the range of percentage force decay in each mechanism over the first 24 h was as follows: (6-5-3) mechanism: 43.39 -68.89 %. (chain loop) mechanism: 41.09 -58.45%. (6-3) mechanism: 27.8661.89%. after 28 days the range of force decay in each mechanism was as follow: (6-5-3) mechanism: 59.38-79.88 %. (chain loop) mechanism: 55.72-72.71%. (6-3) mechanism: 42.95-74.75%. it is obvious from the above that the (6-5-3) mechanism has the highest percentage of force decay throughout the study, therefore it is not recommended to utilize this mechanism for canine retraction .the (chain loop) mechanism has the j bagh college dentistry vol. 25(1), march 2013 force decay of orthodontics, pedodontics and preventive dentistry163 highest initial force values which are regarded as excessive physiological force values, therefore it is also not recommended to utilize this mechanism for canine retraction. the (6-3) mechanism has the smallest mean percentage force decay, therefore it is recommended to utilize this mechanism for canine retraction (12). the present study suggests that in relation to the degradation behavior, the best brand of elastomeric chain is extreme elastomeric chain which consistently had a significantly lesser mean percentage force decay compared to regular type with respect to all three mechanisms. for all the three types of elastomeric chains, mechanism three (6-3) had the smallest mean percentage force decay. this finding suggests that it may be most efficient to retract a canine utilizing elastomeric chain directly from the molar hook to the canine bracket. the chain loop mechanism may not be indicated for space closure in vivo due to the excessive physiological force values involved with the mechanism. references 1. billmeyere fw. thermosetting resins. in: text book of polymer science. wiley, new york, 1984; p. 36-457. 2. renick mr, brantley wa, webb cs, beck fm, vig k, culbertson bm. dsc. studies of orthodontic plastic modules i. asreceived products. j den res 1999; 78: 320. 3. andreasen gf, bishara se. comparison of alastic chains with elastics involved with intra-arch molar to molar forces. angle orthod1970; 40:151-8. 4. de genova dc, mc innes -ledoux p, weinberge r, shaye r. force degradation of orthodontic elastomeric chainsa product comparison study. am j orthod1985; 87:377-84. 5. sonis al, der plas ev, gianelly a. a comparison of elastomeric auxiliaries versus elastic thread on premolar extraction site closure: an in vivo study. j dent orthod 1986; 738. 6. stevenson js, kusy rp. force application and decay characteristics of untreated and treated polyurethane elastomeric chains. angle orthod 1994; 64: 455-67. 7. killiany d, duplessis j. relaxation of elastomeric chains. j clinic orthod 1985; 19:592-3. 8. proffit wr, fields hw, sarver dm. contemporary orthodontics. 4th ed, mosby, an affiliate of elsevier inc., 2007. 9. huget ef, patrick ks, nunez lj. observation on the elastic behavior of a synthetic orthodontic elastomer. j dent res 1990; 496501. 10. lu tc, wang wn, tarng th, chen jw. force decay of elastomeric chain a serial study. part ii. am j orthod dentofac orthop 1993; 104: 373-7. 11. hemed bm. the effect of drinks and food simulants on the force applied by the orthodontic elastomeric chains (an experimental in vitro study). a master thesis, orthodontic department, university of baghdad,2008. 12. balhoff da, shuldberg m, hagan j l, ballard rw, armbruster pc. force decay of elastomeric chains – a mechanical design and product comparison study. j orthod 2011; (38): 40-47. 13. orthotechnology company: orthodontic products catalogue, 2011. 20. wasan f.doc j bagh college dentistry vol. 25(1), march 2013 the effect of autologous oral diagnosis 116 the effect of autologous bone marrow-derived stem cells with estimation of molecular events on tooth socket healing in diabetic rabbits (histological and histomorphometric study) mohamed abdul-hameed mohamed, b.d.s, m.sc. (1) wasan hamdi younis, b.d.s, m.sc., ph.d. (2) nahi yousif yaseen, m.sc., ph.d. (3) abstract background: diabetes is a metabolic disorder characterized by chronic hyperglycemia due to an inability to produce insulin. uncontrolled or poorly controlled diabetes is clinically associated with increased susceptibility to delay healing. many recent researches have shown that stem cell therapy can be the best choice for treatment of this disease. the aims of this research were investigating regeneration of pancreatic beta cells of diabetic induced rabbits after stem cell transplantation. materials and methods: 64 rabbits weighting an average of (2.5 3 kg) were used in this experimental study, and divided into 4 groups as follows; group a ( contains 16 healthy rabbits regarded as control group ) , group b ( contains 16 diabetic rabbits not received treatment ), group c ( contains 16 controlled diabetic rabbits received insulin as a treatment ) and group d ( contains 16 rabbits received mesenchymal stem cells as a treatment) , the lower incisor for each rabbits was extracted and the socket was examined by histological and histomorphometric analysis after 2, 10, 20 and 30 days of healing periods after scarification. results: histological findings showed that there was a normal healing of teeth – extracted sockets (early bone formation, mineralization and maturation) of the animals of group a, c and d when compared with group b. histomorphometric analysis of the parameters (trabecular width (tbw), tb separation(tbs), tb number ( tbno), osteoblasts number (obno), osteocytes number( ocno ) and blood vessels number (bvno) of all groups for all healing periods illustrated that there was a highly significant differences of groups a , c and d when compared with group b animals. conclusions: the present study concluded that there was delayed healing of teeth extracted sockets of the animals of group b (diabetic rabbits) due to the few numbers of osteoblasts (bone-forming cells) which differentiated from the fibroblasts cells and subsequent impairments in bone formation, mineralization and maturation. key words: diabetic rabbits, teeth extraction, delay healing. (j bagh coll dentistry 2013; 25(1):116-121). introduction diabetes mellitus is a chronic, widely spread human disease. experimental induction of diabetes mellitus in animal models is essential for the advancement of our knowledge and understanding of the various aspects of its pathogenesis and ultimately finding new therapies and cure. several methods have been used to induce diabetes mellitus in laboratory animals with variable success and many difficulties. surgical removal of the pancreas is effective method; however, to induce diabetes, at least 90-95% of the pancreas has to be damaged (1). alloxan is a naturally occurring, broad spectrum antibiotic and cytotoxic chemical that is particularly toxic to the pancreas (2). induction of experimental diabetes in the rabbit using alloxan is very convenient and simple to use. (1) ph.d. student, department of oral diagnosis, college of dentistry, baghdad university. (2) professor, head of oral diagnosis department, college of dentistry, baghdad university. (3) professor, general manager of iraqi center for cancer and medical genetic research. alloxan injection leads to the degeneration of the langerhans islets beta cells clinically; symptoms of diabetes are clearly seen in rabbits within 2-4 days following single intravenous or intraperitoneal injection of 100 mg/kg (3). healing of tooth extraction sockets in poorly controlled diabetic patients is often delayed and accompanied by severe infection. current diabetes treatments just aim to lower the blood sugar through diet, exercise, medication with tablets and insulin, in recent researches, mesenchymal stem cells (mscs) have brought to new hope ,the adult bone-marrow derived stem cells can regenerate the beta cell in diabetes animal models. these results lead to a new approach in diabetes treatment, especially type 1. healing of a tooth extraction socket is a complex process involving tissue repair and regeneration. it involves chemotaxis of appropriate cells into the wound, transformation of undifferentiated mesenchymal cells to osteoprogenitor cells, proliferation and differentiation of committed bone forming cells, extracellular matrix synthesis, mineralization of osteoid, maturation and remodeling of bone. these cellular events are precisely controlled and regulated by specific signaling molecules (4-10). j bagh college dentistry vol. 25(1), march 2013 the effect of autologous oral diagnosis 117 materials and methods sixty four adult rabbits weighting an average of (2.5 3 kg) were used, the experimental animals were divided into four groups as follows: group a : contains 16 healthy rabbits regarded as control group. group b : contains 16 diabetic rabbits, not received any treatments. group c : contains 16 controlled diabetic rabbits received insulin as a treatment. group d : contains 16 diabetic rabbits received mscs as a treatment. induction of diabetes mellitus in rabbits (group b, c and d rabbits) the rabbits were injected by a single dose (120 mg/kg) intravenous injection of the pancreatic beta-cells toxin monohydrate (alloxan), which was administered to the rabbits via the marginal ear vein. severity of the induced diabetic state was assessed by daily monitoring of blood glucose levels with a calibrated glucose meter (few drops from the ear) and daily estimation of the body weight. for determination of blood glucose level, the animals whose blood glucose level was greater than 200mg / dl were indicated as hyperglycemic. five to seven days after injection, alloxan induced diabetes by destroying the beta cells of the pancreas; the blood glucose level was elevated above the 200mg/dl (fig.1). animals of group c were received daily insulin as a treatment in a dose of 0.1 mg/ kg of body weight. fig.1: elevation of blood glucose level isolation of mscs from the bone marrow (group d rabbits) the surgery was performed under well sterilized condition and gentle surgical technique. the surgical towels were placed around the site of operation; the site chosen for operation was the proximal tibia metaphysis of the right limb (fig.2). skin incision was done by using a sharp blade to expose the muscle (fig.3). then the muscle was dissected to expose the tibia (fig.4). by intermittent drilling with (1 mm surgical drill) and continuous, vigorous irrigation with sterile normal saline, a guide hole was made (fig.5). by using sterile syringe (5ml) that contains few drops of heparin (to prevent blood clotting) the bone marrow was aspirated as soon as possible (fig.6). after that the area was washed very well with a sterile normal saline, the muscle was sutured with 3/0 absorbable (catgut) suture (fig.7). the skin was sutured with interrupted 3/0 silk suture (fig.8). fig.2: the site of operation fig.3: skin incision fig.4: dissection of the muscle fig.5: 1mm guide hole was made fig.6: aspiration of bone marrow fig.7: cat gut suture j bagh college dentistry vol. 25(1), march 2013 the effect of autologous oral diagnosis 118 fig.8: skin sutured with silk suture inside the hood the bone marrow was inserted into two test tubes t.t.), equal volumes of phosphate buffer saline (pbs) was added to (t.t.) and shake very well ,then the two t.t. was put inside the centrifuge (2000 rpm) for 10 minutes. inside the hood the top two thirds of the solution were removed. rpmi-culture media was added to the precipitate 1/3 of the t.t. & shake very well until the media was became homogenous, then the media was added into a well sterilized plastic falcons & covered very well by a parafilm, finally the media was incubated at (37 °c, 5% co2 & 95% air).the cells were checked periodically under inverted microscope, the culture media was changed twice a week for two weeks. with the medium changes, almost all the non adherent cells were washed away. differentiation of mscs into insulin producing cells 1inside the hood about 2/3 of the medium in the falcons was removed and pre-inducing medium was added to the remaining 1/3 of the falcons, the pre-inducing medium containing low glucose– rpmi (l-rpmi) supplemented with 10 mm nicotinamide, plus 1 mm beta-mercaptoethanol and 10% of fetal bovine serum (fbs), then covered by a parafilm and incubated at (37 °c, 5% co2 & 95% air) (for 24 hours). 2the medium was changed with fresh inducing medium; containing serum free high glucose– rpmi (h-rpmi) , supplemented with 10 mm nicotinamide , plus 1 mm beta-mercaptoethanol , then covered by a parafilm and incubated at (37 °c, 5% co2 & 95% air) (for 10-12 days). detection of insulin producing cells the insulin producing cells can be detected by dithiazone (dtz) stain. dtz is a zinc-chelating agent known to selectively stain pancreatic beta cells because of their high zinc content. inside the hood about 2/3 of the medium was removed from the falcon, then 2 ml of dtz solution was added for the remaining 1/3 of the medium in the falcon that containing the mscs, the cells were incubated at (37 °c, 5% co2 & 95% air) for 30 minutes and examined under inverted microscope. reimplantation of mscs 5 ml of the medium was reimplanted to the rabbits by subcutaneous injection. under sterile condition and gentle surgical technique, the lower incisor of each rabbits for all groups was extracted (fig.9). 2 days after extraction 4 rabbits from each group were killed; 10 days after extraction another 4 rabbits from each group were sacrificed; 20 days after extraction another 4 rabbits from each group were sacrificed; 30 days after extraction the remaining 4 rabbits from each group were sacrificed; the sockets blocks were immediately fixed in 10% formaldehyde solution and processed for histomorphometric and histological evaluations. fig.9 extraction of the incisor tooth the histomorphometric parameters currently used for the description of trabecular bone microarchitecture are all based on parfitt’s principles of the ‘‘plate and rod’’ model (11), these microarchitecture descriptors are: a.trabecular number (tbno), b.trabecular width ( tbwid,in microns),c.trabecular separation ( tbsep,in microns), d.osteoblast cell number ( ob/mm2), e. osteocyte cell number ( oc/mm2) and f. blood vessels number (bvno).these parameters are derived from microscopic two dimension (image measurements analyzer software program, the magnification power lense x40). statistical analysis the following statistical data analysis approaches were used in order to analyze and assess the results of the study: a. mean (m) , b. standard deviation ( sd ) , c. anova test : for the comparison among the groups. j bagh college dentistry vol. 25(1), march 2013 the effect of autologous oral diagnosis 119 results histological examination for description purpose each block (the site of extraction) for each healing period of each group was divided into three regions: cervical, middle and apical regions. the histological examination was performed under a light microscope. histological findings of 2 days: the histological findings of all regions showed that formation of blood clot with fibrinous network connection which infiltrated by inflammatory cells in groups a ,c and d, while in group b the histological finding showed blood clot formation with few numbers of inflammatory cells. histological findings of 10 days: the histological findings showed the proliferation of cellular connective tissue with formation of woven bone, deposition of osteoid tissue, and presence of proliferative osteoblasts and fibroblasts in groups a ,c and d, while in group b the histological findings showed the formation of granulation tissues which were infiltrated by mononuclear cells, there were no signs of osteiod tissues deposition or woven bone formation (fig.10) , (fig. 11). histological findings of 20 days: histological findings showed that formation of new bone trabeculae, some of them were elongated to form rod-like surrounded by osteoblasts with numerous numbers of osteocytes and blood vessels in groups a, c and d while in group b, the histological finding showed sparse, thin osteoid tissue deposition surrounded by a basal bone (fig. 12) , (fig. 13). histological findings of 30 days: histological findings showed thick well formed bone trabeculae that almost filled the entire sockets with numerous osteoblasts and osteocytes in groups a, c and d while in group b, the histological finding showed thin scattered bone trabeculae surrounded by socket bone with deposition of immature woven bone and numerous blood vessels in between(fig. 14) , (fig. 15). histomorphometric analysis data was collected by two dimension image analysis , table1 showed descriptive statistics (m, sd and anova test) of group a at different healing periods for total measurements, table2 showed descriptive statistics (m, sd and anova test) of group b at different healing periods for total measurements, table 3 showed descriptive statistics (m, sd and anova test) of group c at different healing periods for total measurements and table 4 showed descriptive statistics (m, sd and anova test) of group d at different healing periods for total measurements. figures (16 and 17) showed the correlation of the mean of variables measured at different healing periods (10, 20 and 30 days) for all groups. fig.10: 10 days group a showing osteoid tissues. fig.11: 10 days group b showing granulation tissues. fig.12: 20 days group d showing osteoblasts (ob) & osteocytes (oc). ob oc fig.13: 20 days group b showing osteoids. fig.14: 30 days group a showing bone trabeculae (bt). fig.15: 30 days group b showing woven bone (wb). wb bt j bagh college dentistry vol. 25(1), march 2013 the effect of autologous oral diagnosis 120 table 1: descriptive statistics of group a at different healing periods for total measurements variables 10 days 20 days 30 days sig. mean sd mean sd mean sd tbw 1.6667 1.37060 3.7500 .75378 5.8333 1.58592 .000 tbsep 16.7500 2.52713 13.1667 4.40729 11.4167 1.62135 .003 tbno 2.5000 1.08711 8.3333 2.74138 13.5000 1.73205 .000 obno 9.1667 1.58592 20.3333 3.14305 15.5000 2.64575 .001 ocno 3.5833 1.31137 8.0000 2.00000 11.8333 3.18614 .000 bvno 9.7500 1.28806 12.9167 1.16450 5.5000 .90453 .000 table 2: descriptive statistics of group b at different healing periods for total measurements. variables 10 days 20 days 30 days sig. mean sd mean sd mean sd tbw 0.0834 .28865 1.0835 .28862 2.6667 .65134 .000 tbsep 21.9167 2.31432 24.5000 2.90767 21.4167 2.57464 .015 tbno .5000 .52223 1.5833 1.16450 2.4167 .79296 .009 obno .8333 1.19342 4.4167 1.56428 4.5833 1.72986 .017 ocno .5000 1.16775 2.0000 .85280 3.5000 1.44600 .000 bvno 1.5000 52223 2.3333 .49237 1.3333 .49237 .648 table 3: descriptive statistics of group c at different healing periods for total measurements. variables 10 days 20 days 30 days sig. mean sd mean sd mean sd tbw 1.0933 1.07309 2.3333 .65134 5.6667 2.41536 .000 tbsep 15.4167 2.90637 13.5833 2.02073 12.9167 1.24763 .103 tbno 1.7500 1.21543 6.7500 1.42223 12.0000 1.27841 .000 obno 9.1667 1.26730 18.4167 2.53909 15.0833 1.88092 .001 ocno 3.2500 1.71232 7.9167 1.44332 10.8973 1.93324 .000 bvno 8.9167 1.00932 10.4167 .61493 4.9442 .87695 .000 table 4 descriptive statistics of group d at different healing periods for total measurements. variables 10 days 20 days 30 days sig. mean sd mean sd mean sd tbw 1.8333 1.12523 2.6658 1.07986 5.5987 2.45361 .000 tbsep 15.6667 3.25431 12.9587 1.88298 11.5417 1.96873 .210 tbno 1.9998 .87634 5.0896 2.14321 11.3542 2.13245 .000 obno 8.7989 2.34521 19.8765 2.40932 16.7865 1.78259 .000 ocno 3.3300 1.71226 7.8697 1.87695 9.4624 1.76382 .000 bvno 7.1667 1.12453 10.6667 .59845 5.1023 1.00139 .000 fig.16 comparison the mean of tbw, and tbsep with time. fig.17 comparison the mean of tbno, obno, ocno and bvno with time. j bagh college dentistry vol. 25(1), march 2013 the effect of autologous oral diagnosis 121 discussion histological evaluation the results of the present study showed early detection of osteiod tissues formation in cervical region at 10 days of healing periods for groups a,c and d and increased deposition of osteiod tissues in the middle and apical areas. while in group b there was no evidence of osteiod tissues deposition in cervical and middle areas which were restricted for granulation tissue formation with heavy infiltration of mononuclear cells, a sign of extracellular matrix deposition of osteiod tissues were detected only in the apical area of group b. these histological observations were in agreements with sloan (12 , 13) who suggested that in uncontrolled, insulin-dependent diabetes; the formation of the osteiod tissues in the tooth extraction socket is inhibited, resulting in delayed healing and increased alveolar destruction. at 20 and 30 days of healing periods more osteoblsts , osteocytes and blood vessels was detected in groups a,c and d, when compared with group b. this result agreed with luu (14,15) who demonstrated that diabetes leads to the decreased bone formation, because of decreased proliferation and differentiation of osteoblasts when compared with the control animals. histomorphometric evaluation in particular, histomorphometry, based on the use of new computerized methods allow the acquisition of more sophisticated measurements by means of a digitizer have been introduced to integrate the use of the microscope. these methods supply information on cortical width, osteoblasts, osteocytes ,trabecular width, blood vessels as well as on its distribution and on the organization of the trabeculae in the marrow space (16). the equality of means and variance of all parameters tested for micro architecture records between all study groups illustrated a high value in groups a, c and d than those of group b, this result can be explained on a fact of early enhancement and recruitment of the fibroblasts and osteoprogenitor cells to be differentiated into osteoblasts (bone formative cells) and enhancement of osteiod tissue formation which need more supplements and more blood vessels. osteocytes formation was happened by entraption of osteoblasts within their matrix; more osteoblasts resulted in more number of osteocytes and as a result of more and faster building of bone matrix. references 1. akbarzadeh a, norouzian d, mehrabi mr, jamshidi s, farhangi a, allah a, mofidian s, lame rad b induction of diabetes by streptozotocin in rats. ijcb 2007; 22: 60-64. 2. brosky g. and logothetopoulos j. alloxan diabetes in the mouse and guinea pig. diabetes 8: diabetes 1999; 606611. 3. ikebukuro k, adachi y, yamada y, fujimoto s, seino y, oyaizu h.treatment of alloxan-induced diabetes mellitus by transplantation of islet cells plus bone marrow cells via portal vein in rabbits. transplantation 2002; 73(4):518. 4. calhoun jh, laforte aj, yin s. osteogenic protein-1 (bone morphogenetic protein-7) in the treatment of tibial nonunions. j bone joint surg am. 2001; 83 suppl 1: s151-8. 5. street j, bao m, deguzman l, bunting s, peale fv jr, ferrara n, steinmetz h, hoeffel j, cleland jl, daugherty a, van bruggen n, redmond hp, carano ra, filvaroff eh. vascular endothelial growth factor stimulates bone repair by promoting angiogenesis and bone turnover. proc natl acad sci usa 2002: 99: 9656–61. 6. schneir m, ramamurthy n, golub l: skin collagen metabolism in the streptozotocin-induced diabetic rat: enhanced catabolism of collagen formed before and during the diabetic state. diabetes 1982; 31:426. 7. cooley bc, hanel dp, anderson rb. the influence of diabetes on free flap transfer: i. flap survival and microvascular healing. ann plast surg1992; 29: 58-64. 8. devlin h, sloan p, tang n. healing of tooth extraction sockets in diabetic animals 2002; 734-741. 9. zahid sultanali lalani. characterization of healing tissue in a tooth extraction socket in a rabbit model 2002; 387: 938-945. 10. lalani z, wong m, brey em, mikos ag, duke pj. spatial and temporal localization of transforming growth factorbeta, bone morphogenetic protein-2, and vascular endothelial growth factor in healing tooth extraction sockets in a rabbit model. j oral maxillofac surg 2003; 61: 1061. 11. vesterby a, gundersen hjg, melsen f. star volume of marrow space and trabeculae of the first lumbar vertebra: sampling efficiency and biological variation. bone 1989; 10: 7–13. 12. sloan p, devlin h, garland h, healing of tooth extraction sockets in experimental diabetes mellitus 2004; 276-282. 13. devlin h, garland h, sloan p. healing of tooth extraction sockets in experimental diabetes mellitus. j oral maxillofac surg 1996; 54:1087-1091. 14. luu h, song wx, luo x, manning d, luo j, deng zl, sharff ka, montag ag, haydon rc, he tc. distinct roles of bone morphogenetic proteins in osteogenic differentiation of mesenchymal stem cells. j orthop res 2007; 25: 665-77. 15. novaes abjr, marcaccini am, souza sls, taba m jr, grisi mfm. immediate placement of implants into periodontally infected sites in dogs:int j oral maxillofac implants 2003;18: 391-398. 16. carbonare ld,valenti fb,zanata m, zenari s, realdi g, cascio v lo, giannini s. bone microartichture evaluated by histomorphometry. micron. 2005; 36(7-8): 609-16 4. raghad f.doc j bagh college dentistry vol. 27(4), december 2015 a micro computed restorative dentistry 21 a micro computed tomography assessment of new carrier-based root canal fillings raghad a. al-hashimi, b.d.s., m.sc., ph.d. (1) abstract background: the main aim of the present study is to qualify and quantify voids formation of root canals obturated with guttacore (gc) and experimental hydroxyapatite polyethylene (ha/pe) as new carrier-based root canal fillings by using micro computed tomography scan. materials and methods: in the present study, eight straight single-rooted human permanent premolar teeth are selected and disinfected, then stored in distilled water. the teeth decoronated leaving a root length of 12mm each. the root canals instrumented by using crown down technique and the apical diameter of the root canal prepared to a size # 30/0.04 for achieving standardized measurements. a 5ml of 17% edta used to remove the smear layer followed by 5ml of 2.5% naocl and rinsing with normal saline. then the shaped root canals were randomly subdivided into two groups of 4 teeth each according to the carrier-based obturation system use, guttacore or experimental ha/pe. afterwards, the obturated roots stored at 37°c with 100% humidity for 72 hours to allow for complete setting of the sealer. micro-ct was then scanned to quantify the voids within the root canal space. the data were statistically analyzed by one-way anova and post hoc comparison tests (α=0.05). results: the root canals obturated with both obturation systems, guttacore andexperimental ha/pe showed voids formation, particularly at the apical third of the root canal. gc obturation showed a lower percentage of voids volume (1.54%) than the experimental ha/pe obturation (2.3%). the void volume percentage in the guttacore system, however, was non-significantly different (p> 0.05) in comparison with the experimental pe/ha system. conclusions: guttacore and experimental ha/pe obturators exhibited voids formation within the entire root canal space. the experimental ha/pe obturator is comparable to the guttacore obturator in terms of voids qualification key words: obturation, guttacore, micro computed tomography, experimental ha/pe. (j bagh coll dentistry 2015; 27(4):21-24). introduction the success of a root canal treatment depends on three main factors namely, thorough canal debridement, effective disinfection and adequate obturation of the root canal space(1). one of the most critical components in the long term success of root canal treatment is the obturation of the root canal space and the maintenance of a good seal, which leds to a number of new obturating materials with some being lunched commercially in the last decade(2). during obturation of the root canals, athreedimensional spacehas tobe fluid-tight sealed using suitableprocedures along with appropriate voidfree root canal filling materials(3). however, most root canal filling materials do not thoroughly seal the root canal assome voids are frequently created either within root filling material itself or at the material-dentine interface(4). in this situation, possible fluid leakage and bacterial percolation at the root canal interface may therefore be encountered causing periapical lesions and/or failure of the endodontic treatment(5). carrier based obturation systems is one of the most common techniques used for root canal obturation enhancing, adaptability of warm guttapercha to the root canal wall and into lateral canals in a controlled and fast manner(6). several carrier-based obturation systems have been innovated as promising materials for endodontic root canal fillings. (1)assistant professor. department of conservative dentistry, college of dentistry, university of baghdad. over last four years, an obturator-system consisting of a carrier made of cross-linked guttapercha surrounded by the alpha phase of guttapercha (gutta-core, dentsply tulsa dental, ok) has been introduced on the market to facilitate the endodontic re-treatments. besides the gutta-core (gc), an experimental carrier-based obturation system based on silanated hydroxyapatite and polyethylene (ha/pe) coated with gutta-percha has been recently innovated(7). there is little information on voids measurement of new carrier based obturation systems, gutta-core and experimental ha/pe. high resolution micro-computed tomography scan (µct) has been suggested to evaluate the percentage of volume of voids at the canal wallobturation material interface and within the obturation material itself(8-10). µctis a technology used as a research tool in endodontic discipline to study the morphology of the root canal space before and after instrumentation using different types of materials and techniques(11,12). the main aim of the present study is to qualify and quantify the voids volume within the root canal space obturated with new carrier-based root canal filling systems, gutta-core and experimental ha/pe using micro computed tomography technology. the null hypothesis of the present study is that the experimental ha/pe obturator is not comparable to the gutta-core system in terms of voids qualification. j bagh college dentistry vol. 27(4), december 2015 a micro computed restorative dentistry 22 materials and methods synthesis of the experimental ha/pe carrierbased obturator: the preparation of hydroxyapatite/ polyethylene composite core (ha/pe) for carrierbased root canal obturation is performed by a previous study of al-hashimi et, al.(7). tooth selection and instrumentation: eight straight single-rooted human permanent premolar teeth selected and disinfected by sodium hypochlorite and then stored in sterile water. teeth with open apices, root caries, root restoration, root defectsand root resorption were excluded from the study. a root length of 12mm was achieved by cutting the crown of the tooth with a diamond wheel saw. access into the canals was performed and a glide path was created by inserting a hand k-file size #10 (dentsply tulsa dental, tulsa, ok, us) into the canal until it appeared from the apex; this length was calculated and the final working length was fixed at 1mm short of that length. the cleaning and shaping the root canals was carried out with a crown down technique using gates glidden drills size 2, 3 and nickel-titanium hand instruments (dentsplymaillefer). the apical diameter of the canal was prepared to size #30/0.04 for achieving standardized measurements. during preparation, irrigation of the root canals was carried out with 2,5 ml of 2,5% sodium hypochlorite. then the canals were finally flushed with 5ml of 17% edta in order to remove the smear layer followed by 5ml of 2.5% naocl and rinsing with normal saline. obturation of the canals: the cleaned and shaped roots were randomly subdivided into two groups of 4 teeth each according to the carrier-based obturation system used. group 1: guttacore, a metal verifier (dentsply tulsa) corresponding to the size of the final file used (#30/0.04) was placed 0.5mm short of the working length and checked with a periapical radiograph. a thin layer of tubli-seal root canal sealer (sybronendo, orange, ca, us) was used to coat the root canal walls. the obturator was placed into thermaprep® plus obturator oven to soften the two obturators used and then inserted to the pre-determined working length with slight pressure. the handle of the obturators with the remnants of the obturation material around was removed with a round diamond bur. group 2: experimental ha/pe obturation system. the root canals were obturated in a similar manner to the samples in the group 1; the main difference is that the temperature used to soften the experimental obturator was reduced to 100°c by the incorporation of a thermo-regulator connected to the current thermafil® oven to monitor temperature control. afterwards, the obturated roots were stored at 37°c with 100% humidity for 72 hours to allow for complete setting of the sealer. volumetric measurements of the root canal obturation were quantified and qualified using (µct). both systems of gutta-core and experimental ha/pewith the root canal sealer were engaged in the (µct) assessment for void detection. the percentage of the volume of voids was obtained by dividing the total volume of voids by the total volume of root canal obturation, calculated by the µct (ip) software (simple ware®, exeter, uk). the samples were further characterized by evaluating 3d reconstructions. results means and standard deviations of total volume and percentage (%) of voids and gaps in the root canal teeth obturated with gc or the experimental ha/pe are shown in table (1). while, representative twoand three-dimension microct images showing the voids in the root canal obturated using gc or ha/pe are presented in figures 1a-2a and figures 1b-2b, respectively. same lowercase latter indicates no differences in column for the total volume of voids. same upper-case latter indicates no differences in the overall voids within the root canal filled teeth (p>0.05). the percentage of the volume of voids was obtained by dividing the total volume of voids by the total volume of root canal obturation, calculated by the μct (ip) software. gc obturation showed a lower percentage of voids volume (1.54%) than the experimental ha/pe obturation (2.3%). overall, canals obturated with gc presented the lowest percentage of voids, whereas canals obturated with ha/pe showed a higher percentage of voids. the void volume percentage in the guttacore system was nonsignificantly lower (p> 0.05) than that of experimental ha/pe system, particularly in the apical region. the data obtained from μct were analysed with anova followed by bonferroni post hoc test to compare the means by using ssps software version 18(spss inc, chicago, il). j bagh college dentistry vol. 27(4), december 2015 a micro computed restorative dentistry 23 table (1). means and standard deviations of total volume and percentage of voids and gaps in the root canal filled teeth overall voids (%) total volume of voids (mm3) total volume of root obturation (mm3) composition product 1.54% a 0.319 ±0.8 a 20.04 cross-linked gutta-percha guttacore 2.3% a 0.848 ±1.0 a 34.70 hydroxyapatite-polyethylene ha/pe discussion several factors contribute to the success of endodontic therapy. an adequate obturation of the root canal space prevents percolation of microbes into root canal space, favoring the maintenance of a favorable biological environment for healing (13). however, in order to achieve this goal, it is important to useoutstanding high standard obturation materials (14). although the obturating material is of significant issue in endodontic treatment, the obturation technique has also an important role to play and of the different techniques used, carrier based obturation is one of such method. two systems of guttacore and experimental ha/pe were tested as a carrier for gutta-percha to fill the root canal space in three dimensions. the present study aimed at qualifying the voids volume within the root canal space of these two obturation systems using micro-computed tomography technology. the null hypothesis was rejected as the percentage of volume of voids of the experimental obturator was comparable to that of commercial one, gc. although the commercial one showed a lower percentage of voids volume than that of the experimental one, the difference remained nonsignificant statistically. this could be related to the fact that the experimental obturator was not as tapered as the commercial one. the carriers with tapered design are expected to be well-adapted to the root canal walls because of the high accuracy, µct technology with a resolution of 6.5 was used in the current study to locate voids and quantify the volume of voids inside the obturated canal. the µct produced a three-dimensional reconstruction of the root canal fillings and its constituents(15, 16). the findings of µct scan showed that guttacore obturation system exhibited a percentage of voids volume around 1.54% within the whole root canal space, whereas ha/pe systems displayed voids at around 2.3%. a lot of voids of such percentage were characterized in apical region of root canals filled teeth. this finding suggests that the apical control of both carrier systems, guttacore and experimental ha/pe is limited. in conclusion, both carrier-based root canal filling systems figure (2): representative threedimension reconstruction model of micro-ct images of single rooted premolar tooth showing the voids in the root canal obturation in apical, middle and coronal thirds of canal (red) for (a) gutta-core and (b) experimental ha/pe obturators. figure (1): representative micro-ct scans of single rooted premolar tooth showing the voids in the root canal obturation in the apical, middle and coronal thirds of the canal for (a) gutta-core and (b) experimental ha/pe. gp: guttapercha; d: dentine; c: carrier of ha/pe and gc. j bagh college dentistry vol. 27(4), december 2015 a micro computed restorative dentistry 24 exhibited voids presence within the root canal space particularly in the apical region suggesting limited apical control of the obturator system. in addition, the obturation of root canals with experimental ha/pe is comparable to that of guttacore in terms of voids formation. references 1. epley sr, fleischman j, hartwell g, cicalese c. completeness of root canal obturations: epiphany techniques versus gutta-percha techniques. j endod 2006; 32(6): 541-4. 2. li gh, niu ln, zhang w, et al. ability of new obturation materials to improve the seal of the root canal system: a review. acta biomater 2014; 10(3):1050-63. 3. michaud ra, burgess j, barfield rd, cakir d, mcneal sf, eleazer pd. volumetric expansion of gutta-percha in contact with eugenol. j endod 2008; 34(12):1528-32. 4. kontakiotis e, chaniotis a, georgopoulou m. fluid filtration evaluation of three obturation techniques. quintessence int2007; 38(7): e410-6. 5. nair pn, sjogren u, krey g, kahnberg ke, sundqvist g. intraradicular bacteria and fungi in root-filled, asymptomatic human teeth with therapy-resistant periapical lesions: a long-term light and electron microscopic follow-up study. j endod 1990; 16(12): 580-8. 6. li g-h, niu l-n, selem lc, et al. quality of obturation achieved by an endodontic core-carrier system with crosslinked gutta-percha carrier in single-rooted canals. j dentistry 2014; 42(9):112434. 7. al-hashimi ra, mannocci f, foxton rm, deb s. synthesis and preliminary evaluation of a polyolefinbased core for carrier-based root canal obturation. j endod 2012; 38(7): 983-6. 8. el-ma'aita am, qualtrough aj, watts dc.a microcomputed tomography evaluation of mineral trioxide aggregate root canal fillings. j endod 2012; 38(5): 670-2. 9. zogheib c, naaman a, medioni e, bourbouze g, chirani ra. the quality of thermafil obturations with different final apical tapers: a threedimensional microcomputed tomographic comparative study. j contemp dent pract 2012; 13(3): 322-6. 10. zogheib c, naaman a, sigurdsson a, medioni e, bourbouze g, arbab-chirani r. comparative microcomputed tomographic evaluation of two carrierbased obturation systems. clin oral investig 2013; 17(8):1879-83. 11. li x, liu n, liu r, dong z, liu l, deng m. comparative study of root canal morphology of mandibular first premolar by micro-ct and radio visiography. hua xi kou qiang yi xue za zhi 2012; 30(1): 57-60. 12. moura-netto c, palo rm, camargo ch, pameijer ch, bardauil mr. micro-ct assessment of two different endodontic preparation systems. braz oral res 2013; 27(1): 26-30. 13. ng yl, mann v, rahbaran s, lewsey j, gulabivala k. outcome of primary root canal treatment: systematic review of the literature – part 2. influence of clinical factors. int endod j 2008; 41(1): 6-31. 14. moussa-badran s, roy b, bessart du parc as, bruyant m, lefevre b, maurin jc.technical quality of root fillings performed by dental students at the dental teaching centre in reims, france. international endod j 2008; 41(8): 679-84. 15. hammad m, qualtrough a, silikas n. threedimensional evaluation of effectiveness of hand and rotary instrumentation for retreatment of canals filled with different materials. j endod 2008; 34(11):1370-3. 16. hammad m, qualtrough a, silikas n. evaluation of root canal obturation: a three-dimensional in vitro study. j endod 2009; 35(4):541-4. lena f.doc j bagh college dentistry vol. 25(3), september 2013 the effect of thermocycling restorative dentistry 28 the effect of thermocycling on microleakage analysis of bulk filled base composite in comparison to incrementally placed nanohybrid composite in class ii mod restorations (an in vitro study) lena a. hassan, b.d.s. (1) adel f. ibraheem, b.d.s., m.sc. (2) abstract background: the study aim was to evaluate thermocycling effect on microleakage of occlusal and cervical margins of mod cavity filled with bulk filled composites in comparison to incrementally placed nanohybrid composite and to evaluate the difference in microleakage between enamel and dentin margins for the three materials groups. materials and method: forty eight maxillary first premolars were prepared with mod cavities. samples were divided into three groups of sixteen teeth according to material used: grandio: grandio. sdr: sdr +grandio. x-tra: x-tra base + grandio. each group was subdivided into two according to be thermocycled or not. after 24 hrs immersion in 2% methylene blue, samples weresectioned and microleakage was estimated. results: thermocycling significantly increased microleakage at occlusal margin in grandio group compared to other groups. sdr composite use before and after thermocycling significantly reduced microleakage at occlusal and cervical enamel margins compared to other groups. grandio group had non significant difference to x-tra group in microleakage before thermocycling at occlusal and cervical enamel margins while it had a significant increase after thermocycling. no material had significantly reduced dentin margin microleakage before or after thermocycling. only sdr group before thermocycling, significantly reduced microleakage in enamel margin compared to dentin margin. conclusion: thermocycling did not increase microleakage in all the groups except for grandio group in occlusal margin. sdr group showed reduced microleakage in occlusal and enamel margins in comparison to other groups.none of the materials reduced microleakage in dentin margin. keywords: microleakage, thermocycling, bulk filled, nanohybrid. (j bagh coll dentistry 2013; 25(3):28-34). introduction a perfect restoration should provide a permanent and perfect seal between the tooth structure and the restoration margins. any discrepancy in the seal will create a microscopic gap permitting the passage of fluids with its contained bacteria, ions and molecules between the restoration and the tooth structure, named as microleakage(1).microleakage is a significant problem associated with composite restorative materials and it happens due to multiple reasons: as one of the outcomes of polymerization shrinkage of composite resins, due to the mismatch between the thermal expansion coefficients of the tooth and the composite or the mismatch between the elastic moduli of the tooth and the restoration(1,2).many techniques to reduce polymerization shrinkage and stress were investigated in in vitro studies as: light irradiation technologies like using quartz tungsten halogen (qth) or light emitting diode (led),using different irradiation techniques (conventional or soft-start qth irradiation), placing composite resin with different placement techniques (bulk or incremental placement)or the use of an intermediate flowable layer (3-8). (1)m.sc. student. department of conservative dentistry, baghdad university, college of dentistry. (2)professor. department of conservative dentistry, baghdad university, college of dentistry. one of these approaches to reduce stress is the incremental placementof composite as a way to reduce composite constraint and volume during curing. it has been suggested that the oblique incremental restorative technique could limit the effects of polymerization shrinkage at the cavosurface margin (9). however, the restoring of large mod restorations with composite resins using this technique is time consuming (3). there had been multi significant developments to reduce polymerization shrinkage stress either by using composite resin that uses nanotechnology in their fillers so that the filler loading of modern composite resins often exceeds 60% of the filler volume (10,11)or by using modified or nonmethacrylate monomer resin formulations (12).the most recent development in composite resins are bulk filled flowable composite resins to be used under conventional composite resin materials as a liner or a base(13,14) with depth of cure exceeding 4 mm (15).the modified methacrylate resin has a slow polymerization rate through the use of a polymerization modulator (16), the filler content is reported as (68% wt.) for sdr and (75% wt.) for x-tra base (14,17).this means that the time consuming incremental technique for both mesial and distal proximal boxes in class ii cavities could be completed in a single increment with j bagh college dentistry vol. 25(3), september 2013 the effect of thermocycling restorative dentistry 29 bulk filled flowable composite bases and the remaining increments for occlusal cavity would be performed as normal with conventional composite resins (18). materials and methods samples selection and mounting forty eight extracted upper first premolar teeth for orthodontic purposes belong to patients of age 18-24years stored for no more than 3 months examined under magnifying lens to exclude any samples with caries and cracks. the roots of teeth were covered with a layer of wax short of the cervical line in 3mm and a base of cold cure acrylic wasmounted. cavity preparation a modified dental surveyor was used to standardize cavity preparations so the long axis of the bur was parallel to the long axis of the tooth during the preparation. fissure bur (no: 835314009) was used and replaced after four preparations. the teeth received mod cavity of 3mm width and 2mm occlusal depth measured from cavosurface margin. mesial margin (0.51mm) below cemento-enamel junction with axial depth 3mm and distal margin (0.5-1mm) above cemento-enamel junction with axial depth 2mm.length of gingival seat was 1.5mm i butt joints margins(1,2,19-22). cavity depth and width was checked by digital caliper and periodontal probe. samples distribution and restorative technique after teeth preparation matrix band and retainer were placed. xeno self-etch one step adhesive was applied following the manufacturer instructions and light cured from occlusal direction for 20 seconds. the teeth were randomly distributed and named according to the filling materials used into three groupseach contain sixteen samples as follows: • group grandio: restored with grandio material placed with oblique incremental layering technique with 1mm thickness triangular wedges ,by filling the mesial (dentin) box with 6 wedges and distal (enamel box) by 4 wedges followed by 4 triangular for the occlusal remaining cavity each in 1mm thickness layer measured with periodontal probe and cured for 20 seconds . • group sdr: restored with sdr bulk filled low shrinkage base composite in 1 bulk placed layer that starts from the box toward the occlusal surface so that it extends 1m short of the occlusal cavosurface margin and with thickness 4mm for the mesial box and 3mm for the distal box and cured for 20 seconds, then one occlusal layer of 1mm thickness of grandio composite is applied and cured for 20 seconds. • group x-tra: restored with x-tra base bulk filled low shrinkage base composite in 1 bulk placed layer that starts from the box toward the occlusal surface so that it extends 1m short of the occlusal cavosurface margin with 4mm thickness from the mesial side and 3mm from the distal side and cured for 10 seconds, then one occlusal layer of 1mm thickness of grandio composite is applied and cured for 20 seconds. light curing device was checked by digital radiometer before every curing of the samples to ensure 768 mw/cm² light intensity for each time.after curing of the restoration the band and retainer were removed and the occlusal surfaces were finished using low grit diamond finishing burs and polished with rubber points the proximal margins were finished with sof-lex flexible discs (4,16,20,23,24). samples storage and thermocycling of the samples: all the specimens were stored for 24hrs and each group was subdivided into two sub groups of eight teeth each: initial: for direct microleakage measurement. thermo: to be thermocycled. thermocycling was carried out by soaking the specimens alternatively into (5-55 ±1~2cº) water bath chambers with 30 seconds immersion time in each bath and 10 seconds transition time (25) .the thermocycling continued for(66.2 hours)all the 24 specimens were thermocycled in the same time (26,27). the thermocycling machine the thermocycler used in this study was fabricated (by dr. lena a. hassan)following the design of thermocycler 1000 (sd mechatronik co. for dental research equipment, germany) with modification of the original design (fig.1). microleakage measurement: all the samples were dried and two layers of nail varnish were applied short 1mm from the restoration margins. the root apices were sealed with glass-ionmer cement and immersed in 2% methylene blue dye for 24 hours. the samples had been washed under running water and dried.the samples were blocked with cold cure resin thenthe teeth were longitudinally cut in the center and perpendicular to the long axis of the sampleinto four pieces using microtome with a disk thickness of 0.01mm cutting at high speed with water coolant. the first cut dissected the tooth mesiodistally and the second cut was buccolingually. the presence of microleakage j bagh college dentistry vol. 25(3), september 2013 the effect of thermocycling restorative dentistry 30 was done by visualization by two observers using stereomicroscope at 40x magnification. occlusal dye penetration scoring system (20,22,28): 0: no dye penetration 1: leakage not deeper than dentino-enamel junction. 2: leakage deeper than dentino-enamel junction. 3: leakage along occlusal and /or axial wall. 4: leakage into dentinal tubules. cervical dye penetration scoring system (22,29) : 0: no dye penetration. 1: dye penetration not exceeding the middle of cervical wall. 2: dye penetration exceeding the middle of cervical wall. 3: dye penetration up to half the axial wall length. 4: dye penetration along full the axial wall. statistical analysis of the results was done by using one way anova test for non parametric (kruskal wallis test), mann whitney u-test and wilcoxon signed rank test. results in order to see the effect of thermal aging on microleakage, mann-whitney u test was applied and it showed that at the occlusal margin there was significant difference in microleakage median score between initial and thermocycling phases in group grandio (p=0.005),while there was a non significant difference between initial and thermocycling phases for sdr and x-tra groups. at the enamel and dentin margins all the groups showed a non significant difference in microleakage median scores between initial and thermocycling phases. kruskal-wallis test was applied to show the difference in microleakage among the three groups of materials and the results were confirmed by mann-whitney u test. it showed that for the occlusal margin in the initial phase there was a significant difference in median scores among the three groups with the highest median score in both groups grandio and x-tra (median score was the same=ii) and with non significant difference between them.while the lowest median score was in group sdr (mean score=i) with a significant difference between sdr and grandio groups and a significant difference between sdr and x-tra groups. while in the thermocycling phase there was a significant difference in median scores among the three groups with the highest median score in group grandio (median score=iii) and the lowestmedian score was in group sdr (median score=i).at the dentin margin in the initial and thermocycling phases there was a non significant difference in the median scores of microleakage among the three groups of materials.at the enamel margin in the initial phase there was a significant difference in median scores among the three groups with the highest median score in both groups grandio and x-tra (median score was the same=iv) and with non significant difference between them. while the lowest median score was in group sdr (sdr+grandio) (median score=ii) with a significant difference between sdr group and grandio group and a significant difference between sdr group and xtra group. in the thermocycling phase there was a significant difference in median scores among the three groups with the highest median score in both groups grandio and x-tra (median score was the same=iv) and with non significant difference between them. while the lowest median score was in group sdr (median score=ii) with a significant difference between sdr group and grandio group and a significant difference between sdr group and x-tra group. wilcoxon-signed rank test was applied in order to locate the difference in microleakage between enamel and dentin margins for the three groups of materials at the initial and thermocycling phases and there was no statistical significant difference between enamel and dentin margins for group grandio and group x-tra in both initial and thermocycling phases and in group sdr in the thermocycling phase. the exception was group sdr in the initial phase, there was statistically significant increased microleakage in dentin marginin comparison to enamel margin. discussion the effect of thermal aging on microleakage at the occlusal margin for group sdr (grandio+sdr) and x-tra (grandio+x-tra base), the difference in microleakage median scores was non significantstatisticallybetween initial and thermocycling phases. this is in agreement with the results obtained by aguiaret al. (30) (fig. 2 b,c). there was a significant difference in microleakage median scores between initial and thermocycling phases of group grandio (fig.2a). this means that the use of sdr and x-tra base had reduced the effect of thermocycling at the occlusal margin. the explanation might be although the occlusal most layer of all the groups were filled by grandio material but the higher strain capacity and low elastic modulus of the two flowable base composites (sdr material in sdr and x-tra base material in x-tra groups), had provided an advantage to protect the restoration from thermal stress that could cause further damage to the tooth restoration interface combined with already applied polymerization j bagh college dentistry vol. 25(3), september 2013 the effect of thermocycling restorative dentistry 31 shrinkage stress that occurred in group grandio(3133). microleakage increase in group grandio might be also related to the effect of the restorative technique of the deep layers and its influence on the occlusal most layers. versluis et al. noted that oblique and horizontal incremental restorative techniques resulted in much higher coronal surface stresses than bulk curing technique (34). another explanation to the increased microleakage after thermocycling in group grandio is the voids formation at the margins that may lead to gross microleakage (35).the voids formation could be because of the voids formation ability of the material due to the high filler loading combined with restorative technique that may caused entrapment of air and voids between layers in addition to water storage and hydrolysis of the adhesive that increased the microleakage more than the thermal stress on grandio material (36,37). at the cervical margin the results showed there was statistically non significant increase in microleakage between initial and thermocycled phases for each of the three groups in enamel and dentin margins.this means that thermocycling or absence of it did not affect cervical margin sealing ability of the three groups of materials .this goes with agreement with a study conducted by rossomando and wendt and aguiar et al. (30,38). the effect of materials and techniques on microleakage the occlusal margin at the occlusal margin in the initial phase, when comparing sdr and grandio groups, sdr had statistically significant lower microleakage median score than grandio. the explanation is that sdr had reduced the amount of stress applied at occlusal margin and reduced microleakage amount due to bond failure. this may be related to the stress reduction quality of sdr base material (due to the presence of the more flexible ebpdma in its polymer matrix)with its low shrinkage stress (1.57 mpa) and low elastic modulus combined with the use of bulk filling technique (39-40). in comparison the higher stress of grandio material(2.7mpa)with the use of oblique incremental technique might increased the stress at the occlusal margin and led to the higher microleakage(35,41).when comparing sdr and x-tra base groups, sdr had statistically significant lower median score of microleakage than x-tra. this could be explained by the lower stress value of sdr that reduced the amount of stress applied at the occlusal margin, in comparison to the higher stress value of x-tra base (5.93mpa). this increase in stress in x-tra base material could be related to the effect of tegdma in its matrix that produce higher carbon double bonds concentrations leading to increased degree of conversion and increased shrinkage stress (4) in comparison to the low shrinkage stress of ebpdma in sdr material (40).while there was statistically non significant difference between median scores of groups grandio and x-tra base (fig.3 a). at thermocycling phase, there was significant difference in microleakage median score among all the groups (fig.3 a), with the highest in grandio group. the cause is the same as in the initial phase but in thermocycling phase, the lower microleakage value of sdr and x-tra base is due to the higher strain capacity and low elastic modulus of the two flowable base composites, had provided an advantage to protect the restoration from thermal stress that could cause further damage to the tooth restoration interfacecombinedwith the already applied polymerization shrinkage stress (30-33). for grandio's group the increased microleakage (combined the thermal stress with higher polymerization shrinkage stress of the material) might be related to the higher elastic modulus(due to high filler loading), stress build up from the restorative technique and the voids formation in addition to the effect of water storage and hydrolysis of the adhesive, increased the microleakage more than the effect of thermal stress alone on grandio material(36,37) . the cervical margins at the dentin margin in both the initial and thermocycling phases, there was a non significant difference among the median scores of the three groups of materials. this result is with agreement with the results of reis et al. and munroz-viveros et al. (21, 28)(figure 3 b). at the enamel margin in both the initial and thermocycling phases, there was a non significant difference in microleakage median scores between grandio group and x-tra base group. this result agrees with the results obtained by moorthyet al. (18). there was a significant difference between sdr group and grandio, and between sdr group and x-tra base group, with the lowest microleakage median score in sdr group (figure 3 c). this result disagrees with the results of moorthy et al. (18). this difference could be related to the differences in bond strength between the bonding systems (xeno v self etch was used in this study while they used all bond three step adhesive system) with the differences in response of the adhesive systems to the polymerization shrinkage stress applied by the three materials. the explanation to the reduced microleakage in sdr group might be related to the lower j bagh college dentistry vol. 25(3), september 2013 the effect of thermocycling restorative dentistry 32 polymerization shrinkage stress of sdr material (due to the modified monomer formulation) that allows more stress relief in sdr, with its low elastic modulus may applied less stress at the margin than the other two materials(42-44).another explanation is the voids formation at the margins that may lead to gross microleakage (35).the voids formation in grandio group could be related to the effect of oblique restorative technique used that may caused entrapment of air and voids formation between the layers or because of the ability of the material itself to form voids due to its high filler loading (37,45).while the increase in microleakage for x-tra base group might be also relatedto the high voids formation ability of x-tra base material combined with larger marginal gap formation ability ,lower flowability and increased porosity due to its high filler loading in comparison to sdr material that has a lower filler loading, more flowability and higher marginal adaptation as it was found by benetti et al (37,42,44-46). the difference in microleakage between enamel and dentin margins there was statistically non significant difference in microleakage median scores between enamel and dentin margins for all the groups in both initial and thermocycling phases. this agrees with the results obtained by majeed et al. (47). an exception to that was sdr group in the initial phase, that showed a significant difference in median score value between enamel and dentin margins (dentin margin showed a higher degree of microleakage). this result disagrees with the results obtained by a previous study by roggendorf et al. (16).while the result is in agreement with the study conducted by reis et al. (21). the better influence of sdr material on enamel margin could be related to the better performance of the adhesive used when there is tolerable stress application on the adhesive/tooth interface by the polymerization shrinkage (16) combined with better bonding strength to the enamel margin in comparison to the dentin margin.in vitrostudies have indicated that the dentin margin in class ii composite restorations is the most common location of bonding failures (48). references 1. stockton l, tsang t, mccomb d. microleakage of class ii posterior composite restorations with gingival margins placed entirely within dentin. j cda 2007; 73: 255-255f. 2. sadeghi m. the effect of fluid composite as gingival layer on microleakage of class ii composite restorations. dent res j 2007; 4(1):40-7. 3. abbas g, fleming gjp, harrington e, shortall acc, burke fjt. cuspal movement in premolar teeth restored with a packable composite cured in bulk or incrementally. j dent 2003; 31:437-44. 4. fleming gjp, hall d, shortall acc, burke fjt. cuspal movement and microleakage in premolar teeth restored with posterior filling materials of varying reported volumetric shrinkage values. j dent 2005; 33:139-46. 5. palin wm, fleming gjp, nathwani h, burke fjt, randall rc. in vitro cuspal deflection and microleakage of maxillary premolars restored with novel low-shrink dental composites. dent mater 2005; 21: 324-35. 6. fleming gjp, cara rr, palin wm, burke fjt. cuspal movement and microleakage in premolar teeth restored with resin-based filling materials cured using a ‘soft-start’ polymerization protocol. dent mater 2007a; 23:637-43. 7. fleming gjp, khan s, afzal o, palin wm, burke fjt. investigation of polymeriztaion shrinkage strain, associated cuspal movement and microleakage of mod cavities restored incrementally with resin-based composite using an led light curing unit. j dent 2007b; 35: 97-103. 8. cara rr, fleming gjp, palin wm, walmsley ad, burke fjt. cuspal deflection and microleakage in premolar teeth restored with resin-based composites with and without an intermediary flowable layer. j dent 2007; 35:482-9. 9. lim bs, ferracane jl, sakaguchi rl, condon jr. reduction of polymerization contraction stress for dental composites by two-step light-activation. dent mater 2002; 18(6):436-44. 10. mitra sb, wu d, holmes bn. an application of nanotechnology in advanced dental materials. jada 2003; 134:1382-90. 11. ilie n, hickel r. investigations on mechanical behavior of dental composites. clin oral invest 2009; 13:427-38. 12. guggenberger r, weinmann w. exploring beyond methacrylates .am j dent 2000; 13:82d-4d. 13. product specification for sdr (dentsply caulk, milford, de, usa) 2011. 14. product specification for x-tra base (voco gmbh, cuxhaven, germany) 2011. 15. campodonico ce, tantbirojn d, olin ps, versluis a. cuspal deflection and depth of cure in resin-based composite restorations filled by using bulk, incremental and transtooth-illumination techniques. jada 2011; 142:1176-82. 16. roggendorf mj, kramer n, appelt a, naumann m, frankenberger r. marginal quality of flowable 4-mm base vs. conventionally layered resin composite. j dent 2011; 39:643-7. 17. ilie n, hickel r. investigations on a methacrylatebased flowable composite based on sdrtm technology. dent mater 2011a; 27:348-55. 18. moorthy a, hogg ch, dowling ah, grufferty bf, benetti ar, fleming gjp. cuspal deflection and microleakage in premolar teeth restored with bulk-fill flowable resin-based composite base materials. j dent 2012; 40:500-5. 19. deliperi s , bardwell d, papathanasiou a, kastali s, garcía-godoy f. microleakage of a microhybrid composite resin using three different adhesive placement techniques. j adhes dent 2004; 6:1-5. 20. araujo fo, vieira lcc, monteiro junior s. influence of resin composite shade and location of the gingival j bagh college dentistry vol. 25(3), september 2013 the effect of thermocycling restorative dentistry 33 margin on the microleakage of posterior restorations. oper dent 2006; 31(5):556-61. 21. reis af, alexandre rs, bertrand s,dai q ,jin x. marginal assessment of cavities restored with a low stress bulk-filling composite. iadr 2010. abstract#654. 22. dennison jb, sarret dc. prediction and diagnosis of clinical out comes affecting restoration margins. j oral rehab 2012; 39(4):301-18. 23. gharizadeh n, moradi k, haghighizadeh mh. a study of microleakage in class ii composite restorations using four different curing techniques. oper dent 2007; 32(4):336-40. 24. agrawal vs, parekh vv, shah nc. comparative evaluation of microleakage of silorane-based composite and nanohybrid composite with or without polyethylene fiber inserts in class ii restorations: an in vitro study. oper dent 2012; 37(5):e1-e7. 25. iso 4049:2009(e) dentistry polymer-based restorative materials. génève: international organization for standardization. switzerland; 2009. 26. heintze s, forjanic m, cavalleri a. microleakage of class ii restorations with different tracers-comparison with sem quantitative analysis. j adhes dent 2008; 10:259-67. 27. raskin a, tassery h, d’hoore w, gonthier s, vreven j, degrange m, et al. influence of the number of sections on reliability of in vitro microleakage evaluations. am j dent 2003; 16:207-210. 28. munroz-viveros c, yazici ar, agarwali,campellofunollet m. microleakage of class ii preparations restored with sonicfill system .iadr2012,usa. abstract #466. 29. ozel e, soyman m. effect of fiber nets, application techniques and flowable composites on microleakage and the effect of fiber nets on polymerization shrinkage in class ii mod cavities. oper dent. 2009; 34:174-80. 30. aguiar fh, dos santos aj, frança fm, paulillo la, lovadino jr. a quantitative method of measuring the microleakage of thermocycled or non-thermocycled posterior tooth restorations. oper dent 2003; 28(6):793-9. 31. ferdianakis k. microleakage reduction from newer esthetic restorative materials in permanent molars. j clinped dent 1998; 22(3):221-9. 32. braga rr, hilton tj, ferracane jl. contraction stress of flowable composite materials and their efficacy as stress relieving layers. jada 2003; 134:721-8. 33. wattanawongpitak n, yoshikawa t, burrow m, tagami j. the effect of thermal stress on bonding durability of resin composite adaptation to the cavity wall .dent mater 2007; 26(3):445-50. 34. versluis a, douglas wh, cross m, sakaguchi rl. does an incremental filling technique reduce polymerization shrinkage stresses? j dent res 1996; 75: 871-8. 35. opdam nj, roeters jj, peters tc, burgersdijk rc, teunis m. cavity wall adaptation and voids in adhesive class i resin composite restorations. dent mater 1996; 12:230-5. 36. cenci ms, pereira-cenci t, donassollo ta, sommer l, strapasson a, demarco ff. influence of thermal stress on marginal integrity of restorative materials. j appl oral sci 2008; 16(2):106-10. 37. nazari a, sadr a, saghiri ma, campillo-funollet m, hamba h, shimada y, tagami j, sumi y. nondestructive characterization of voids in six flowable composites using swept-source optical coherence tomography. dent mater 2013; 29:278-86. 38. rossomando kj, wendt sl jr. thermocycling and dwell times in microleakage evaluation for bonded restorations. dent mater1995; 11(1):47-51. 39. sideridou i, tserki v, papanastasiou g. effect of chemical structure on degree of conversion in lightcured dimethacrylate-based dental resins. biomaterials 2002; 23(8):1819-29. 40. czashp, ilie n. in vitro comparison of mechanical properties and degree of cure of bulk fill composites. clin oral invest 2013; 17:227-35. 41. grandio; scientific documentation, 2011; vocoinc. 42. sdr scientific compendium(2011) .sdr™ smart dentin replacement .dentsply inc. www.dentsply.eu 43. x-tra base product brochure, voco internal measureents, 2011. 44. benetti ar, havendrup-pedersen c, honore d, pedersen m k, pallesen u. contraction ,polymerization depth and gap formation of 4-mm resin bases. iadr 2012, usa. abstract# 386. 45. schulze ka, zaman aa, soderholm kj. effect of filler fraction on strength, viscosity and porosity of experimental compomer materials .j dent 2003; 31: 373-82. 46. bayne sc, thompson jy, swift ej, stamatiades p, wilkerson m. a characterization of first-generation flowable composites. jada1998; 129:567-77. 47. majeed a, osman yi, al-omari t. microleakage of four composite resin systems in class ii restorations. sadj 2009; 64(10):484-8. 48. ferracane jl. hygroscopic and hydrolytic effects in dental polymer networks. dent mater 2006; 22:21122. figure 1. the thermocycler. http://www.dentsply.eu j bagh college dentistry vol. 25(3), september 2013 the effect of thermocycling restorative dentistry 34 a b c figure 2. the difference in microleakage median score between initial and thermocycling phases of the three groups of materials (a: at the occlusal margin, b: at the dentin margin, c: at the enamel margin). a b c figure 3. the difference in microleakage median score among the three groups of materials in initial and in thermocycling phases (a: at the occlusal margin, b: at the dentin margin, c: at the enamel margin) yassameen final.doc j bagh college dentistry vol. 26(2), june 2014 tensile force measurement orthodontics, pedodontics and preventive dentistry 167 tensile force measurement by using different lingual retainer wires, bonding materials types and thickness (a comparative in vitro study) yassameen a. salih, b.d.s. (1) mushriq f. al-janabi, b.d.s., m.sc. (2) abstract background: the bonded orthodontic retainer constructed from multistrand wire and composite is an efficient esthetic retainer, which can be maintained long-term. clinical failures of bonded orthodontic retainers, most commonly at the wire/composite interface, have been reported. this in vitro investigation aimed to evaluate the tensile forces of selected multistrand wires and composite materials that are available for use in the construction of bonded fixed retainers. materials and methods: the study sample includes 120 wires with three types of retainer wires (3 braided strands\ orthotechnology, 8 braided strands\ g&h orthodontics, 6 coaxial strands\ orthoclassic wires), two types of adhesive (flowable\ orthotechnology, non flowable\ g&h orthodontics composites) and two thickness of the adhesive (1mm, 2mm). the samples were prepared for each composite in which a wire was embedded; then the composite was light cured for 40 seconds and the specimens were stored in artificial saliva at 37°c in the incubator for 24 hours. the ends of the wire were drawn up and tensile force was applied through tinius-olsen universal testing machine until the resin failed and the results were recorded in newton (n). results: statistical analysis showed that there was a highly significant difference (p ≤ 0.01) among the mean values of tensile forces of the three types of retainer wires in each thickness of composite with exception of a non significant difference (p > 0.05) between (3 braided) and (8 braided) and a non significant difference (p > 0.05) between (3 braided) and (6 coaxial) in both thickness of composite, a highly significant difference (p ≤ 0.01) between the two thickness of both composite types in each wire type and a highly significant difference (p ≤ 0.01) between the two types of composite in each wire type of both thickness of composite. conclusion: the result of this study revealed that the 8 braided strands retainer wire shows the highest values of tensile force among the tested retainer wires, the non flowable composite demonstrates a higher tensile force than the flowable composite and increasing the thickness of composite overlying the wire increased the force required to detach the wire from the composite. key words: retainer wires, flowable composite, tensile force. (j bagh coll dentistry 2014; 26(2): 167-172). introduction the phenomenon of relapse is well recognized and documented in the orthodontic literature (1, 2). after active treatment is complete, long-term preservation of the corrected tooth positions is desirable, both for the clinician and for the patient. unwanted post-treatment tooth movements have been attributed to a number of factors including periodontal fiber reorganization (3), growth changes after treatment (4), and type of treatment undertaken (5). to counter such relapse, the employment of bonded retainers to the mandibular (6) or maxillary (7) incisors has become an established part of orthodontic practice. bonded lingual retainers are fabricated in various designs which consist of a combination of different wires in various sizes and of different compositions (8). traditionally, bonded retainers have been attached to the teeth with composite. various composites have been described for use in this technique including both restorative and orthodontic bonding materials. thinning of the (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad composite was previously advised to obtain the best handling characteristics, but there was still some difficulty (9). recently, the use of flowable composites, which were originally created for restorative dentistry by increasing the resin content of traditional microfilled composites, have been suggested for bonding lingual retainers (10-12). this in vitro investigation aims to compare selected materials that are available for use in the construction of bonded orthodontic retainers to identify materials that may improve the clinical performance of these retainers. the wire tensile forces were tested in tensile model using three different types of lingual retainer wires with two types of bonding materials and two thickness of composite. materials and methods three types of retainer wires were used in this study: 1. braided retainer wire (3 strands braided) (orthotechnology) 2. bond-a-braid lingual retainer (8 strands braided) (reliance orthodontic products) j bagh college dentistry vol. 26(2), june 2014 tensile force measurement orthodontics, pedodontics and preventive dentistry 168 3. srw™ stranded retention wire (6 strands coaxial) (orthoclassic). two types of bonding materials were used in this study: 1. resilience® low viscosity light-cure flowable composite (orthotechnology) 2. light cure retainer (non flowable composite) (reliance bonding products) cylindrical acrylic blocks (figure 1) were prepared in metal molds, 25 mm in diameter and 10 mm height. forty blocks were allocated to each of the three test groups, with a hole 3 mm in diameter and 4 mm deep in the upper surface of each block to represent the length of wire embedded in composite clinically in a bonded retainer. a 1 mm-wide groove in the upper surface across the diameter of the block to accommodate the wire. the groove with different depths of 1.0, 2.0 mm in each test group to represent the total depth of the wire and composite material on the tooth surface (13). figure 1: acrylic blocks thin uniform coat of the bonding agent was applied by brush on surfaces of the hole of each block to be bonded. a 10-cm length of the tested wire was placed at the base of the groove and the empty insert in the center of the slot was filled with the testing material using the appropriate syringe, and excess is removed by carver. the composite was then light cured for 40 seconds. the ends of the wire were drawn up and twisted at a distance of 1 cm so that they could be secured using the attachment arm of the tensile load cell of the universal testing machine. with this arrangement, a force could be applied perpendicular to the long axis of embedded wire to cause wire pull out (13). (figure 2) after completion bonding procedure, the specimens were allowed to bench set for 15 minutes to ensure complete polymerization of adhesive material. then the specimens were immersed in artificial saliva and stored in the incubator at 37°c for 24 hours prior to tensile test. figure 2: the sample after bonding procedure tensile test was accomplished using a tiniusolsen universal testing machine with speed of 10 mm/minute. the connected ends of the wire were secured and drawn up until separation of wire from composite occurs. the maximum force required to remove the wire from the composite was recorded (13) (figure 3). the force required to remove the wire from the composite was recorded in newton (n). figure 3: tensile test statistical analysis data were collected and analyzed using spss (statistical package of social science) software version 17 for windows xp. in this study the following statistics were used: 1. descriptive statistics: including; mean and standard deviation. 2. inferential statistics: including; one way analysis of variance (anova), least significant difference (lsd) and ttest. rreessuullttss descriptive statistics and wire type’s differences in each thickness in flowable composite descriptive statistics were performed for the three types of retainer wires (3 braided, 8 braided, and 6 coaxial) in each thickness of flowable composite. the (8 braided wire) showed higher j bagh college dentistry vol. 26(2), june 2014 tensile force measurement orthodontics, pedodontics and preventive dentistry 169 mean values of tensile force than the 3 braided and 6 coaxial wires in both thickness of flowable composite and the (6 coaxial wire) showed the lowest value of tensile force in thickness 1 mm of flowable composite while in thickness 2 mm the (3 braided wire) showed the lowest value. (table 1) one way analysis of variance (anova) showed a highly significant difference among the mean values of tensile forces of the three types of retainer wires in each thickness of flowable composite. (table 1) then the least significant difference (lsd) test was performed to differentiate between the types of retainer wires in each thickness of flowable composite and showed a highly significant difference between wire types with exception of a non significant difference between (3 braided) and (8 braided) in 1 mm thickness and a non significant difference between (3 braided) and (6 coaxial) in 2 mm thickness of flowable composite. table 1: descriptive data of tensile forces and anova test between the three retainer wires types in flowable composite thickness of composite wire types descriptive statistics of tensile force (n) wire comparison anova test mean max. min. s.d. s.e. f-test p-value 1mm 3 braided 17.9 23.5 13.5 3.13 0.99 15.07 0.000 ** 8 braided 20.05 23.5 18.5 1.69 0.53 6 coaxial 13.9 18.5 11.5 2.59 0.82 2mm 3 braided 51.3 61.5 41.5 7.16 2.26 22.24 0.000 ** 8 braided 70.2 78.5 60 8.28 2.62 6 coaxial 53.25 58.5 41.5 5.09 1.61 no. of samples for each group=10, (**) highly significant difference descriptive statistics and wire type’s differences in each thickness in non-flowable composite the (8 braided wire) showed higher mean values of tensile force than the 3 braided and 6 coaxial wires in both thickness of non-flowable composite and the (6 coaxial wire) showed the lowest value of tensile force in thickness 1 mm of flowable composite while in thickness 2 mm the (3 braided wire) showed the lowest value. (table 2) one way analysis of variance (anova) showed a highly significant difference among the mean values of tensile forces of the three types of retainer wires in each thickness of non-flowable composite. (table 2) then the least significant difference (lsd) test was performed to differentiate between types of retainer wires in each thickness of non-flowable composite and showed a highly significant difference between wire types in each thickness of composite with exception of a non significant difference between (3 braided) and (8 braided) in 1 mm thickness of composite and between (3 braided) and (6 coaxial) in 2 mm thickness of composite. table 2: descriptive data of tensile forces and anova test between the three retainer wires types in non-flowable composite thickness of composite wire types descriptive statistics of tensile force (n) wire comparison anova test mean max. min. s.d. s.e. f-test p-value 1mm 3 braided 35 43.5 23.5 5.61 1.77 31.63 0.000 ** 8 braided 36.1 43.5 31.5 4.16 1.32 6 coaxial 21.9 26.5 16.5 3.23 1.02 2mm 3 braided 93.75 103.5 85 5.53 1.75 47.05 0.000 ** 8 braided 126.65 133.5 115 6.39 2.02 6 coaxial 94.45 108.5 73.5 12.40 3.92 no. of samples for each group=10, (**) highly significant difference descriptive statistics and thickness difference in each wire type in flowable composite descriptive statistics were performed for the two thickness of flowable composite (1 mm, 2 mm) in each retainer wire type. the thickness (2 mm) of flowable composite showed higher mean values of tensile force than the thickness (1 mm) in each type of retainer wires. (table 3) j bagh college dentistry vol. 26(2), june 2014 tensile force measurement orthodontics, pedodontics and preventive dentistry 170 t-test showed a highly significant difference between thickness of flowable composite in each wire type. (table 3) table 3: descriptive data of tensile forces and t-test between two thickness of flowable composite in each retainer wire type wire types thickness of composite descriptive statistics of tensile force (n) thickness difference mean max. min. s.d. s.e. t-test p-value 3 braided 1mm 17.90 23.5 13.5 3.13 0.99 -13.52 0.000 ** 2mm 51.30 61.5 41.5 7.16 2.26 8 braided 1mm 20.05 23.5 18.5 1.69 0.53 -18.76 0.000 ** 2mm 70.20 78.5 60 8.28 2.62 6 coaxial 1mm 13.90 18.5 11.5 2.59 0.82 -21.79 0.000 ** 2mm 53.25 58.5 41.5 5.09 1.61 no. of samples for each group=10, (**) highly significant difference descriptive statistics and thickness difference in each wire type in non flowable composite descriptive statistics were performed for the two thickness of non-flowable composite (1 mm, 2 mm) in each retainer wire type. the thickness (2 mm) of non-flowable composite showed higher mean values of tensile force than the thickness (1 mm) in each type of retainer wires (table 4). t-test showed a highly significant difference between thicknesses of nonflowable composite in each wire type. (table 4) table 4: descriptive data of tensile forces and t-test between two thickness of non-flowable composite in each retainer wire type wire types thickness of composite descriptive statistics of tensile force (n) thickness difference mean max. min. s.d. s.e. t-test p-value 3 braided 1mm 35 43.5 23.5 5.61 1.77 -23.58 0.000 ** 2mm 93.75 103.5 85 5.53 1.75 8 braided 1mm 36.1 43.5 31.5 4.16 1.32 -37.57 0.000 ** 2mm 126.65 133.5 115 6.39 2.02 6 coaxial 1mm 21.9 26.5 16.5 3.23 1.02 -17.89 0.000 ** 2mm 94.45 108.5 73.5 12.40 3.92 no. of samples for each group=10, (**) highly significant difference descriptive statistics and material difference in each wire type of 1 mm thickness descriptive statistics were performed for the two types of bonding materials (flowable, non flowable composites) of thickness 1 mm in each retainer wire type. the non-flowable composite showed higher mean values of tensile force than the flowable composite in each type of retainer wires (table 5). t-test showed a highly significant difference between the two types of composite in each wire type of 1 mm thickness of composite (table 5). table 5: descriptive data of tensile forces and t-test between the 1 mm thickness of two types of composite in each retainer wire type wire types material descriptive statistics of tensile force(n) material difference mean max. min. s.d. s.e. t-test p-value 3 braided flowable 17.9 23.5 13.5 3.13 0.99 -8.42 0.000 ** non flowable 35 43.5 23.5 5.61 1.77 8 braided flowable 20.05 23.5 18.5 1.69 0.53 -11.29 0.000 ** non flowable 36.1 43.5 31.5 4.16 1.32 6 coaxial flowable 13.9 18.5 11.5 2.59 0.82 -6.11 0.000 ** non flowable 21.9 26.5 16.5 3.23 1.02 no. of samples for each group=10, (**) highly significant difference j bagh college dentistry vol. 26(2), june 2014 tensile force measurement orthodontics, pedodontics and preventive dentistry 171 descriptive statistics and material difference in each wire type of 2 mm thickness descriptive statistics were performed for the two types of bonding materials (flowable, non flowable composites) of thickness 2 mm in each retainer wire type. the non-flowable composite showed higher mean values of tensile force than the flowable composite in each type of retainer wires. (table 6) t-test showed a highly significant difference between the two types of composite in each wire type of 2 mm thickness of composite. (table 6) table 6: descriptive data of tensile forces and t-test between the 2 mm thickness of two types of composite in each retainer wire type wire types material descriptive statistics of tensile force (n) material difference mean max. min. s.d. s.e. t-test p-value 3 braided flowable 51.3 61.5 41.5 7.16 2.26 -14.84 0.000 ** non flowable 93.75 103.5 85 5.53 1.75 8 braided flowable 70.2 78.5 60 8.28 2.62 -17.07 0.000 ** non flowable 126.65 133.5 115 6.39 2.02 6 coaxial flowable 53.25 58.5 41.5 5.09 1.61 -9.72 0.000 ** non flowable 94.45 108.5 73.5 12.40 3.92 no. of samples for each group=10, (**) highly significant difference discussion type and diameter of wire the flattened eight-stranded wires (reliance) with width of 0.64 mm (0.025 inch) gave the highest force values, followed by the threestranded wires (orthotechnology) with width of 0.71 mm (0.028 inch), this is because increasing the number of strands incorporated in each wire will increase the surface area of adhesion with the composite, while the six-coaxial wires (orthoclassic) with width of 0.495mm (0.0195inch) giving the lowest value because the larger diameter wire, with greater surface area increase the retention of the wire with the composite when it is being pulling out of the composite. thickness of composite the force required to remove the wire from the composite increased, as expected, as the thickness of composite increased, the thickness of composite that actually overlies the wire is obtained by subtracting the wire depth, in this investigation 0.2 mm, from the depth of the groove. therefore the thickness of composite overlying the wire in the 1.00 mm group is 0.8 mm, and in the 2.00 mm group represents specimens with 1.8 mm thickness of composite overlying the wire. type of composite statistical analysis reveals that there is highly significant difference between light cure retainer (non flowable composite) and light cure flowable composite as the light cure retainer (non flowable composite) give higher force values than the flowable composite. this is because as thinning of the composite advised to obtain the best handling characteristics but increasing the resin content of traditional microfilled composite as the flowable composites has a 20% to 25% lower filler content than conventional composites, in addition, a greater proportion of diluent monomers can be added to the composition, resulting in an increase in the ratio of resin to filler and a reduction in viscosity, this improved flowability allows these resins to be packaged in syringes with smallgauge dispensing needles, facilitating and simplifying placement. for direct resin-based materials (non flowable), the greater the filler content, the greater the mechanical properties, while flowable resins have significantly lower mechanical properties than conventional composites with their lower filler content, they are less rigid (lower elastic modulus) than conventional composites, this reduces the amount of force needed to remove the wire. references 1. reidel ra. a review of the retention problem. angle orthod 1960; 30: 179-94. (ivsl) 2. nanda rs, nanda sk. considerations of dentofacial growth in long-term retention and stability: is active retention needed? am j orthod dentofacial orthop 1992; 101: 297–302 3. southard te, southard ka, tolley ea. periodontal force: a potential cause for relapse. am j orthod dentofacial orthop 1992; 101: 221–7. 4. richardson me. late lower arch crowding: the role of differential horizontal growth. br j orthod 1994; 21: 379–385. 5. sadowsky c, schneider bj, begole ea, tahir e. long-term stability after orthodontic treatment: nonextraction with prolonged retention. am j orthod dentofacial orthop1994; 106: 243-249. j bagh college dentistry vol. 26(2), june 2014 tensile force measurement orthodontics, pedodontics and preventive dentistry 172 6. stormann i, ehmer u. a prospective randomised study of different retainer types. j orofacial orthop 2002; 63: 42–50. 7. naraghi s, andren a, kjellberg h, mohlin bo. relapse tendency after orthodontic correction of upper front teeth retained with a bonded retainer. angle orthod 2006; 76(4): 570-6. (ivsl) 8. artun j, spadafora at, shapiro pa, mcneill rw, chapko mk. hygiene status associated with different types of bonded orthodontic canine to canine retainers. j clin period 1987; 14 : 89 – 94 9. zachrisson bu. third generation mandibular bonded lingual retainer. j clin orthod. 1995; 29: 39 – 48. 10. elaut j , asscherickx k , vande vannet b , wehrbein h. flowable composites for bonding lingual retainers . j clin orthod 2002; 36: 597 – 8. 11. geserick m, ball j, wichelhaus a. bonding fiberreinforced lingual retainers with color-reactivating flowable composite. j clin orthod 2004; 38: 560 – 2. 12. geserick m, wichelhaus a. a color-reactivated flowable composite for bonding lingual retainers. j clin orthod 2004; 38: 165 –6. 13. bearn dr, mccabe jf, gordon ph, aird jc. bonded orthodontic retainers: the wire-composite interface. am j orthod dentofacial orthop 1997; 111: 67–74 zainab final.doc j bagh college dentistry vol. 26(3), september 2014 validity of hounsfield oral diagnosis 79 validity of hounsfield units from computed tomographic images of mandibular bone in detection of osteoporosis zainab m. al-bahrani, b.d.s., h.d.d., m.sc. (1) abstract background: the figure for the clinical application of computed tomography have been increased significantly in oral and maxillofacial field that supply the dentists with sufficient data enables them to play a main role in screening osteoporosis, therefore hounsfield units of mandibular computed tomography view used as a main indicator to predict general skeleton osteoporosis and fracture risk factor. material and methods: thirty subjects (7 males &23 females) with a mean age of (60.1) years underwent computed tomographic scanning for different diagnostic assessment in head and neck region. the mandibular bone quality of them were determined through hounsfield units of ct scan images and were correlated with the bone mineral density values obtained from t-scores of lumbar spine using dual x-ray absorptiometry scans (dexa). results: there was a highly significant positive correlation [p-value 0.000 (hs)] of bone mineral density that measured by t-score of dual x-ray absorptiometrical scan and hounsfield units with very strong relation in measuring the bone density (r test) = 0.969, this close relation lead to predict osteoporosity and the chance of fracture occurrence using a statistical equation that classified the patients as osteoporotic. conclusion: hounsfield units obtained from computed tomography scans that are made for any purposes can provide an alternative clinical parameter to predict osteoporosis at no additional cost to the patient and no additional radiation. key words: hounsfield units, dexa, osteoporosis. (j bagh coll dentistry 2014; 26(3):79-83). الخالصة من لعب الدور الرئیسي في فحص لقد تزاید التطبیق السریري للتصویر المقطعي بشكل كبیر في مجال الفم و الوجھ والفكین مما قدم ألطباء األسنان بیانات كافیة تمكنھم :الخلفیة را رئیسیا للتنبؤ بھشاشة العظام الھیكلي العام و معامل خطر لحدوث ھشاشة العظام ، وبالتالي اصبح استخدام وحدة ھاونسفیلد في التصویر المقطعي للفك السفلي یوصف بكونھ مؤش .الكسور سنة تم استخدام المسح الشعاعي الطبقي لھم لغرض التشخیص التقییمي في منطقة الرأس و الرقبة و ) 60.1( عمر بمتوسط ) إناث 23ذكور و 7( ثالثون شخصا :المواد و الطریقة ي القطني باستخدام فك السفلي من خالل وحدات ھاونسفیلد لصور االشعة المقطعیة وربطھا مع قیم كثافة العظام التي تم الحصول علیھا من فحص العمود الفقرتحدید نوعیة العظم لل .المسح االمتصاصي المزدوج لألشعة السینیة مع وجود عالقة احصائیة قویة جدا في قیاس p value) (0.000ھاونسفیلد وقیمة كثافة المعادن في العظام و حدات كان ھناك ارتباط ذات داللة عالیة من اإلیجابیة بین: النتائج .وفرصة حدوث الكسر باستخدام المعادلة اإلحصائیة التي تصنف المرضى على اساس ھشاشة العظام ، وھذا یؤدي إلى عالقة وثیقة التنبؤ r-test = (0.969(كثافة العظام م دون أي تكلفة إضافیة او ان استخدام وحدات ھاونسفیلد في المسح التصویري المقطعي التي یتم إجراؤه ألي غرض توفر البدیل السریري للتنبؤ بمرض ھشاشة العظا :تنتاج االس للمریض.اي اشعاعات إضافیة introduction osteoporosis "porous bones” is a generalized systemic skeletal disease affects the entire skeleton characterized by low bone mass and microarchitectural deterioration of bony tissue, with a resultant increase in bone fragility and susceptibility to fracture (minimal trauma fractures), (1) `the bone mass loss usually occurs silently and progressively often, there are no symptoms until the first fracture occurs (2). osteoporosis is usually associated with oral bone loss furthermore; it shows that osteoporosis results in lower bone mineral density (bmd) of mandibles, (3,4) it affects the craniofacial and oral structures with the same rate as the total body (5,6) considerable work has been carried out on developing a method to detect individuals with low bone mass at an early stage, so that therapeutic intervention may limit the disease process (3). most clinicians were taught directly or indirectly that bone density is the gauge for assessing bone strength. in recent years, however, the concept has moved beyond density alone and has expanded to include number of characteristics (1)assistant lecturer. department of oral diagnosis. college of dentistry, university of baghdad. of bone that collectively are called "quality" (7). the assessment of bone density and quality can be determined by using a variety of techniques: quantitative computed tomography (qct), quantitative ultrasound (qus), single or dual photon absorptiometry (spa&dpa), and by dual x-ray absorptiometry (dxa) or called dual energy x-ray absorptiometry (dexa) (2,8) which considered the golden method for measurement of low bone mineral density (bmd) that associated with osteoporosis and it allows detailed visualization of osseous structures (9). dexa scanner produces two x-ray beams, each with different energy levels one beam is high energy while the other is low energy. the bone density can be measured by the difference between the two beams depending on the bone thickness. although osteoporosis involves the whole body, measurements of bmd at one site can be predictive of fractures at other sites, so dexa scanning usually focuses on two main obvious areas: the hip, and the spine, but in certain situations if the hip or spine can't be measured, for instance it is measured in the forearm (10). the mandibular bone changes due to osteoporosis can be estimated on the other hand j bagh college dentistry vol. 26(3), september 2014 validity of hounsfield oral diagnosis 80 by different image analysis of x-ray techniques. (11) computed tomography (ct) scan is one of the imaging technique that shows bony details in cross sections and provides a three-dimensional dataset that can be used for studying bone tissue attenuation independent of the surrounding soft tissue in which the ct numbers, or x-ray attenuation, in each voxel of a tissue is resembling by direct hounsfield unit that provides information about the quality of the examined boney tissue including its density referenced to a standard calibration according to a scale, based on values for air (-1000 hu), water (0 hu), and bone (+1000 hu). many studies have evaluated the use of hu to assess the relative bone density of the jaws in ct, and seem to be a useful method to analyze bone density (12-14). materiald and methods the total sample consist of (61) subjects referred to computed tomography unit at x-ray institute / medical city to have computed tomography (ct) scanning in head and neck regions as part of their diagnostic assessment for one or more of different clinical problems using (toshiba 64s, 2012 ct scanning machine). the bone quality values for all patients were determined from the two-dimensional phantomless ct images in the trabecular field of the mandibular bone at different points in the region of interest "roi" (incisor, premolar, and molar regions), halfway buccolingually between the buccal and lingual cortical plates. approximately (1–1.5cm2) should be leaved out from any nontrabecular fields such as teeth, bony cortex, mental symphysis and mandibular canal using (aquilion systems,vitrea software) that display digital dicom images from a conventional axial tomographic view of linear beam based on direct measurement for the mean number of hounsfield unit (hu), so that optical density at a specific area is correlated with its bone density, fig.(1) out of (61) subjects only (30) subjects were included (7 males &23 females) with mean age of (68.7 years) were with low mandibular bone quality <150 hu interpreted according to the misch (15) classification categories of bones: (d1, 1250 hu; d2, 850-1250 hu; d3, 350-850 hu; d4, 150-350; and d5, < 150 hu), after a permission was sought from those patients to perform bone densitometry, they were referred to dexa unit at the same institute (x-ray institute / medical city), to do scanning for the lumbar spine (l1-l4) which is considered the gold standard method for the diagnosis of osteoporosis in which the bone mineral density was performed using (dexxum 3, osteosys spine alg: 2 scanner using ver. 2.0 software analysis), fig. (2). the bone density was measured in absolute terms (g/cm2) and compared to a known standard of the device manufacturer which is typically the t-score that refers to the number of standard deviations above or below the mean for a healthy young adult of the same sex and ethnicity as the patient. dexa findings were classified according to the world health organization (who) establishment diagnostic guidelines: t-score ≥ −1.0 is considered normal, a score −2.5 < t-score < −1.0 is classified as osteopenia, and a t-score ≤ −2.5 is defined as osteoporosis.(16) both recorded data from ct and dexa were analyzed statistically. figure 1: axial mandible ct of osteoporotic mandibular bone density measurement in hounsfield unit (mean: 79 hu). figure 2: dexa scan of the lumbar spine with total (t-score -3.1) of l1-l4 in osteoporotic patient j bagh college dentistry vol. 26(3), september 2014 validity of hounsfield oral diagnosis 81 results out of (30) patients, 7 (23.3 %) were males and 23 (76.7%) were females, representing a female: male ratio of (3.29:1). the age rang was (45–73) years, with mean age of (60.1). the frequency distribution of the study sample among various age groups appears as eight patients in the age group (45-54) years, thirteen patients in the age group (55-64) years, and nine patients in the age group (65-73) years that illustrate the age group (55-64) years was with the highest proportion(43.3%) as shown in table (1). the diagnosis of osteoporosis by computed tomography in this study depending on the validity of hounsfield unit. the clinical inclusion criteria was according to misch(15) classification categories of bones density {any case with low mandibular bone density<150 hu (d5) is considered a suspected case}, out of the 61 patients all the (30) patients whom included in the study sample were recorded as (d5), the mean number of (hu) was (≤ 82 hu) with total average of (68.73 hu). regarding to the bone densitometry by dexa scan the total t-score for lumbar spine from l1 to l4 of all (30) patients ranging between (-2.6) to (4.4) with mean t-score of (-3.2), so they were identified as cases of osteoporosis according to the who criteria for bone mass density at the lumbar spine. the matching of collected data about bone mass density between the two imaging modalities showed a high statistical correlation in detecting osteoporosis with (r = 0.969) and high significant (p-value = 0.000). to find the relationship between two variables, a special statistical analysis was used for assessing the association between mandibular bone density measured by hu and t-score lumbar spine dexa. that lead to predict the value of standard t-score for each patient from the mean number of hu, this relationship calculated from [regression equation "y= a +b x"] since y= t-score constant, a= constant/y-intercept, b= hu coefficients, table (2). this relation was with non significant differences as the p-value=0.206 between the actual and predicted t-score of bone density, table (3). table 1: frequency distribution of the study sample by age and gender age group (years) n % (45-54) 8 32.1 (55-64) 13 43.3 (65-73) 9 32.1 range (45–73) mean (60.1) gender n % female 23 76.7 male 7 23.3 total 30 100 table 2: relation between the ct and dexa in measuring the bone density ct (hu) dexa (t-score) r 0.969 p-value 0.000 (hs) model un-standardized coefficients t-test p-value b s.d. constant (a) -6.733 0.172 -39.126 0.000 (hs) c.t. 0.051 0.002 20.696 0.000 (hs) y = 6.733 + 0.051 x where y= t-score, a= constant, b= coefficients, x= c.t. (hu) table 3: comparison between the actual and predicted bone density dexa value dexa descriptive statistics differences d.f.=29 mean s.d. mean differences.d. t-test p-value actual -3.200 0.47 0.027 0.12 1.294 0.206 (ns) predicted -3.227 0.45 j bagh college dentistry vol. 26(3), september 2014 validity of hounsfield oral diagnosis 82 discussion bone density is the most useful measurement tool in estimating osteoporosis and relative risk factor of non-traumatic fractures occurrence due to available possibility for measurement in contrast to the other factors contributing to fractures including the kind of physical activity, and lifestyle factors that are difficult to quantify(2). osteoporosis is often referred to age-related disorder that causes the gradual loss of bone density and strength. according to the world health organization (who) this disease may be classified as primary and secondary osteoporosis, primary type is divided into primary type 1 that is mostly common in old aged women (after menopause) than male, this explain the female: male ratio of (3.29:1) in the current study (76.7 %females and 23.3 % males) due to postmenopausal hormonal disturbance, and primary type 2 that occurs at old aged people and seen in both females and males (16). the national osteoporosis foundation recommends the testing of bmd to confirm the diagnosis and to determine disease severity). (17) the rapid advancement in ct technology in addition to wide range of its application in different maxillofacial and other clinical practice makes the evaluation of bone density very applicable. this study had obtained bone density by the mean hounsfield unit (hu) values from ct images in which the bone density in each selected voxel measured according to x-ray attenuation coefficient of trabecular field of mandibular bone that is more metabolically active than other compact bone and is the first to change in response to osteoporosis.(18) because of the unavailable standardized reference data for the value of hu threshold in osteoporosis so any patients with low bone quality (d5) that considered a very soft bone, with incomplete mineralization and large intertrabecular spaces (15) they were included in the study as they considered as suspected to have osteoporosis and all of them were with very low hu values the mean number of (hu) was (≤ 82 hu) with total average of (68.73 hu). mean hu values decreased consistently with age specially in age group (65-73) years this finding was agreed with farré et al study ( 19) which conclude that the older the patient, the greater the decrease in hu values of bone density. because most of international guidelines for osteoporosis recommends the application of dexa scan for spine and hip as a mirror for total skeleton osteoporosis and there is no available specific dexa software have been designed for the mandible due to superimposition of the mandible by cervical spine(3) all the study sample were referred for spine dexa. the results of this study revealed that each suspected case with low bone density by hu was with t-score ≤ −2.5 which classified as osteoporotic according to the (who) establishment diagnostic guidelines for osteoporosis which presented a high statistical correlation with (r = 0.969) and high significance p-value this agreed with sungjoon et al. (20) study who found that the bone density by diagnostic ct-based hu value and dxa-based showed strong positive correlation. schreiber et al. (21) study illustrates significant correlations between hounsfield unit and dual x-ray absorptiometry scores of lumbar spine. kribbs et al. (22) study attempted to determine relationships between bone mass in the mandible and skeletal bone mass in a group of postmenopausal women with osteoporosis found mandibular mass was highly correlated with all skeletal measures. the high statistical correlation of current study will guide to predict osteoporosis resembling by t-score from the correlated value of hu using regression equation since comparison between the actual and predicted tscore using paired sample t-test was with mean differences of only 0.027 between actual test -3.200 (s.d.=0.47) and predicted t-test -3.227(s.d.=0.45) with p-value=0.206(ns) . this data can be applied as a predictor for fracture risk, diagnosis of osteoporosis, and early prescription of necessary treatment. the validity of ct scanning in predicting and monitoring of osteoporosis when compared to that of dexa has the benefits of giving a true volumetric findings in contrast to the areal findings obtained from dexa. references 1. world health organ tech rep ser. prevention and management of osteoporosis 2003; 921: 1-164. 2. celenk c, celenk p. bone density measurement using computed tomography. in: saba l (ed.). computed tomography clinical applications. 1st ed. in tech; 2012. pp. 123-36. 3. horner k, devlin h, alsop cw, hodgkinson im, adams je. mandibular bone mineral density as a predictor of skeletal osteoporosis. br j radiol 1996; 69: 1019–25. 4. horner k, devlin h. clinical bone densitometric study of mandibular atrophy using dental panoramic tomography. j dent 1992; 20: 33–37. 5. taguchi a, tanimoto k, suei y, wada t. tooth loss and mandibular osteopenia. oral surg oral med oral pathol oral radiol endodontol 1995; 79(1): 127-32. 6. krall ea, dawson-hughes b, papas a, garcia ri. tooth loss and skeletal bone density in healthy postmenopausal women. osteoporos int 1994; 4(2): 104-9. j bagh college dentistry vol. 26(3), september 2014 validity of hounsfield oral diagnosis 83 7. angelo l. bone density vs. bone quality: what’s a clinician to do? cleveland clin j medicine 2009; 76 (6): 331-6. 8. consensus development conference: diagnosis, prophylaxis, and treatment of osteoporosis. am j med 1993; 94: 646–50. 9. jon a, david a, curtis w. dual x-ray absorptiometry recognizing image artifacts and pathology. am j roentgenol 2000; 174(6): 1699-705. 10. david t. dexa scan (dual x-ray absorptiometry) to measure bone health. b d scan medicine net 2013. 11. bozˇic m, ihan hren n. osteoporosis and mandibles. dentomaxillofacial radiology 2005; 35: 178–84. 12. nackaerts o, maes f, yan h, couto souza p, pauwels r, jacobs r. analysis of intensity variability in multislice and cone beam computed tomography. clin oral implants res 2011; 22(8): 873-9. 13. turkyilmaz i, tözüm tf, tumer mc. bone density assessments of oral implant sites using computerized tomography. j oral rehabil 2007; 34(4): 267-72. 14. aksoy u, eratalay k, tözüm tf. the possible association among bone density values, resonance frequency measurements, tactile sense, and histomorphometric evaluations of dental implant osteotomy sites: a preliminary study. implant dent 2009; 18(4): 316-25. 15. misch ce. density of bone: effect on treatment plans, surgical approach, healing, and progressive bone loading. inter j oral implantol 1990; 6(2): 23–31. 16. who. assessment of fracture risk and its application to screening for postmenopausal osteoporosis. report of a who study group. world health organization technical report series 1994; 843: 1–129. 17. national osteoporosis foundation. medications that may cause bone lossdpack of 50. available at: http://www.nof.org/catalog/order_form_stand_alone_0 80505. accessed july 26, 2005. old jl, calvert m. vertebral compression fractures in the elderly. american family physician 2004; 69 (1): 111–6. 18. reinbold wd, genant hk, reiser uj, harris st, ettinger b. bone mineral content in early postmenopausal and postmenopausal osteoporotic women: comparison of measurement methods. radiology 1986; 160: 469-478. 19. farré-pagés n, augé-castro ml, alaejos-algarra f, mareque-bueno j, ferrés-padró e, hernández-alfaro f. relation between bone density and primary implant stability. med oral patol oral cir bucal 2011; 16 (1): e62-7. 20. sungjoon l, chun kc, so hee oh, sung bp. correlation between bone mineral density measured by dual-energy x-ray absorptiometry and hounsfield units measured by diagnostic ct in lumbar spine. j korean neurosurg soc 2013; 54: 384-9. 21. schreiber jj, anderson pa, rosas hg, buchholz al, au ag. hounsfield units for assessing bone mineral density and strength: a tool for osteoporosis management. j bone joint surg am 2011; 93(11): 1057-63. 22. kribbs pj, chesnut ch, ott sm, kilcoyne rf. relationships between mandibular and skeletal bone in an osteoporotic population. j prosthet dent 1989; 62(6): 703-7. http://www.nof.org/catalog/order_form_stand_alone_0 shatha final.doc j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 41 evaluation of corrosion behavior of bioceramics coated commercially pure titanium and ti-6al-4v alloy hanan ali, b.d.s. (1) shatha saleem, b.d.s., m.sc. (2) thair l. al-zubaydi, b.sc., m.sc., ph.d. (3) abstract background: this study report the corrosion behavior of commercially pure titanium and ti-6al-4v alloy samples without coating and with hydroxyapatite, partial stabilized zirconia and mixture of partial stabilized zirconia and hydroxyapatite coating and comparison between them through electrochemical polarization tests in 37 0 c hank's solution. materials and methods: electrophoretic deposition technique (epd) was used to achieve the coating from each one of three types of the coating materials (hap, psz and mixture of 50% hap and 50%psz) on cp ti and ti-6al-4v alloy samples. the electrochemical corrosion test was performed when samples were exposed to hank's solution prepared in the laboratory and the polarization potential, corrosion rate and the open circuit potential of the samples were measured. results: the results indicated that the corrosion rate is significantly higher for ti-6al-4v than for cp ti .the three types of coating significantly reduced the corrosion rate for cp ti while did not for ti-6al-4v alloy .after coating the corrosion rate for ti-6al-4v remained significantly higher than the coated cp ti samples .the open circuit potential (ocp) for both cp ti and ti-6al-4v samples was in the following sequence psz > hap> mixture of hap and psz >uncoated. conclusions: cp ti showed less corrosion rate than ti-6al-4v alloy with and without coating .coating significantly decreased the corrosion rate of cp ti but did not for ti-6al-4v alloy. key words: corrosion, pure titanium, ti-6al-4v alloy. (j bagh coll dentistry 2014; 26(3):41-48). صةالخال ات اخرى لمادة الزراعة مثل ان تحقق نجاح عملیة زراعة االسنان سریریا لیس بسبب المتانة المیكانیكیة او االنسجام الحیوي المتمیز لمادة الزراعة وحسب بل بسبب صف: المقدمة .خواص السطح وسلوك التاكل الزركونیا المثبتة جزئیا وخلیط ,الھایدروكسي ابیتایت (الء متجانس لواحد من ثالثة انوع من طبقات الطالء استعمل الترسیب بالھجرة الكھربائیة للحصول على ط: المواد وطریقة العمل ). ti-6al-4v(على النماذج المكونة من التیتانیوم النقي وسبیكة )الھایدروكسي ابیتایتاوالزركونیا المثبتة جزئیا یاسھا للنماذج في محلول الجسم المماثل المحضر مختبریا وایضا قیاس جھد االستقطاب ومعدل التاكل وجھد الدائرة المفتوحةاما بالنسبة الختبارات التاكل الكھروكیمیاوي فقد تم ق اضح لنماذج التیتانیوم النقي ولقد لوحظ ان معدل التاكل قل بشكل و.عند مقارنتھا مع التیتانیوم النقي ti-6al-4vتشیر نتائج ھذة الدراسة الى ان ھناك معدل تاكل عالي لسبیكة : النتائج .بعد الطالء أعلى من التیتانیوم النقي ti-6al-4vوایضا بقي معدل التاكل لسبیكة .ti-6al-4vالمطلیة بالطالئات الثالث بینما ذالك لم یظھر لسبیكة -ti-6alلطالء قلل معدل التاكل للتیتانیوم النقي بینما ذالك لم یθثر على سلوك سبیكة ا.قبل الطالء وبعد الطالء ti-6al-4vمعدل التاكل للتیتانیوم النقي اقل من سبیكة :االستنتاجات 4v . introduction oral implantology provides a reliable and rather safe solution to replace missing teeth (1). clinical success of osseointegrated implant depends on many factors. those related are mechanical properties, biocompatibility and corrosion resistant of implant material. corrosion is defined as the action, process, or effect of corroding is a product of corroding, the loss of elemental constituents to the adjacent environment (1). resistance to corrosion is critically important for dental materials especially implant materials. corrosion can lead to roughing of the surface, weakening of the restoration and liberation of elements from the metal or alloy, liberation of elements can produce discoloration of adjacent soft tissue; local pain or swelling in the absence of infection was attributed to corrosion products of the implant material (2). (1) m.sc. student. department of prosthodontics. college of dentistry, university of baghdad. (2) professor. department of prosthodontics. college of dentistry, university of baghdad. (3) senior scientific researcher, ministry of science and technology, baghdad, iraq bone loss and osteolysis was attributed to the particles that are released, are reportedly phagocyted by macrophages stimulating the release of inflammatory mediators such as cytokines. these mediators are released towards bone surface contributing to its resorption by osteoblast activation (3). commercially pure titanium and titanium six aluminum four vanadium (ti-6al-4v) alloys are more frequently used implant materials osseointegration the implant could be coated by bioactive materials like hap. it was found better bonding between the bones and implant material ti-6al-7nb coated with hap or partial stabilized zirconia psz or mixture of both than uncoated samples when implanted in rabbit tibia (4). this work is designed to study the corrosion behavior of uncoated cp ti and ti-6al-4v implant material through evaluation the corrosion note and the results were compared with those of coated samples with hap, psz and mixture of 50/50 hap and psz. j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 42 materials and methods sample preparation commercially pure titanium and ti-6al-4v alloy was used as the substrate for coating. thirty two small rectangular pieces of (27 mm x17 mm x 2 mm) was used for ti-6al-4v alloy and thirty two small rectangular (17 mm x17 mm x5 mm) for cp ti. after polishing and ultrasonic cleaning, they were divided into four subgroups according to coating material, eight samples from each metal were kept uncoated, eight samples were coated with hap powder, eight samples were coated with psz, eight samples were coated with mixture of 50/50 hap and psz by electrophoretic technique . electrophoretic deposition in this study three suspensions were prepared according to the type of coating material used. the first suspension was used for hydroxyapatite coating .the suspension was prepared by adding hap powder to the solvent which was the ethanol (100g/i liter) in a container over a stirrer without adding any dispersant agent or binder agent (5). the stirring was continued until a colloidal suspension was obtained .the second suspension was used for psz coating. the suspension-was prepared by adding psz powder to solvent which is ethyl alcohol (200 g/1 liter) in a container over a stirrer. phosphate ester (3 g/1 liter) dispersant agent was added. after stirring the polyvinylbutyral was added as a binder (3.5g/1 liter) (6). the third suspension was prepared by adding 50:50 ratio hap /psz powders to the solvent which was ethyl alcohol in a container over a stirrer, after 10 minutes phosphate ester 3 g/1liter dispersant agent was added. and after stirring, polyvinylbutyral was added as a binder (3.5g/1) (4). microscopical examination one sample from each type of the coating was examined by using optical microscope (nikon type 120, japan optical microscope) to show the appearance of the coated surface layer of the sample. x-ray phase analysis phase analysis was employed on cp ti and ti6al -4v alloy samples before and after coating with different materials using 3121 powders x-ray diffractometer using cu ka radiation. the 2θ angles were swept from 20-80 o in step of one degree. electrochemical corrosion test electrolyte solution preparation the electrolyte used was hank’s solution (nacl, kcl, cacl, mgso4.7h2o, nah2po4.2h2o, nahco3, glucase, kh2po4, mgcl2.6h2o) (7). a constant temperature of 37±2 0 c was maintained by using a water path. tafel extrapolation the potentiodynamic polarization test was used to evaluate corrosion behavior by measuring the corrosion rate. electrochemical corrosion test system was composed from potentiostat and glass cell and its electrodes; working electrode we, counter electrode ce and reference electrode re .the specimen was fixed on orifice on the side of corrosion cell through 1cm diameter for one hour. the corrosion-potential ecorr and corrosion current density icorr were determined which were used to measure the corrosion rate by mmpy by the following equation: corrosion rate (mmpy) =0.13 × icorr × ew/d ×1000×25.4 ………(1). in this study the unit used to measure corrosion rate is mmpy (millimeter per year) therefore to convert the unit from mpy (mils pear year) to mmpy. the equation is multiplied by 1000 and 25.4 because the mils mean milli-inch (inch=1000 milliinch) (inch=25.4 millimeter). results x-ray diffraction of coating samples figure 1 show the xrd patterns of ti-6al-4v specimens coated with hap by electrophoretic deposition method and heat treated at 400o c in comparison with uncoated specimen .the pattern of uncoated ti-6al-4v specimens shows strong line of αti at 2θ .the xrd results of hap coated specimens shows strong line of hap.the xrd patterns of ti-6al-4v alloy coated with psz in comparison with uncoated specimen is shown in figure 2. the pattern indicated that surface of specimens are well covered with psz layer. the specimens coated with mixture of hap powder and psz showed the domination of psz in the coated layers shown in figure 3.the xrd pattern of uncoated cp ti specimens showed strong line of α ti, while the xrd results of hap coated specimens showed strong line of hap as shown in figure 4.the xrd patterns of cp ti coated with psz in comparison with uncoated specimen is shown in figure 5.the pattern indicated that surface of specimens are well covered with psz layer. figure 6 is showing the xrd of specimens of cp ti coated with mixture of hap powder and psz, the xrd pattern shows the domination of psz in the coated layer. j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 43 microscopical examination micrographs illustrate the microstructure of uncoated, hap, psz and mixture of hap and psz coated cp ti alloy surfaces before corrosion figure (7) and figure (8).the surface of cp ti samples coated with hap shows rough surfaces; no cracks appear on the surface of any sample, figure (7)b. the surface of cp ti samples coated with a layer of psz shows tree like appearance of the coated layer, figure (7) c. the surface of cp ti samples coated with the mixture of hap and psz shows homogenous and rough surfaces with no cracks appear on any sample, figure (8) micrographs illustrate the microstructure of figure 1: x-ray diffraction patterns of hap coated ti-6al-4v specimens in comparison with uncoated specimen figure 2: x-ray diffraction patterns of psz coated ti-6al-4v specimens in comparison with uncoated specimen figure 3: x-ray diffraction patterns of ti-6al-4v specimens coated with hap and psz in comparison with uncoated specimen figure 5: x-ray diffraction patterns of psz coated cp ti specimens in comparison with uncoated specimen figure 6: x-ray diffraction patterns of cp ti specimens coated with hap and psz in comparison specimen with uncoated figure 4: x-ray diffraction patterns of psz coated cp ti specimens in comparison with uncoated specimen j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 44 uncoated, hap, psz and mixture of hap and psz coated ti-6al-4v surfaces before corrosion are shown in figure (9) and figure (10).the surface of ti-6al-4v samples coated with hap shows non homogenous surfaces with large number of porosity and small uncoated areas randomly distributed on the surfaces of all samples figure (9)b the surface of ti-6al-4v samples coated with psz shows uniform surfaces and continuous smooth surfaces without porosity and no cracks appear on the surface of any sample, figure (10) a. the surface of ti-6al4v samples coated with the mixture of hap and psz shows non homogenous and rough surfaces with no cracks appear on the surface of any sample, figure (10) b. auncoated cp-ti bcp ti coated hap ccp ti coated with psz figure 7: optical micrograph view of cp ti, a) uncoated cp ti; b) cp ti coated with hap; c) cp ti coated psz before corrosion figure 8: optical micrograph view of cp ti coated with mixture of hap and psz before corrosion auncoated ti-6al-4valloy bti-6al-4v coated with hap figure 9: optical micrograph view of ti-6al-4valloy, a) uncoated ti-6al-4valloy; b) ti-6al-4valloy coated with hap before corrosion ati-6al-4v coated with psz b-ti-6al-4v coated hap and psz figure 10: optical micrograph view of ti-6al-4v alloy, a) ti-6al-4valloy coated psz; b) ti-6al-4valloy coated with mixture of hap and psz before corrosion. j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 45 after corrosion, the microstructure of hap, psz and mixture of hap and psz coated ti-6al4v surfaces are shown in figure (11).the surface of ti-6al-4v sample coated with hap shows large uncoated areas randomly distributed on the surfaces figure (11) a. the surface of ti-6al-4v sample coated with psz shows crack on the surface but the surface of alloy is not seen figure (11) b. the surface of ti-6al-4v sample coated with the mixture of hap and psz shows large uncoated area figure (11) c. corrosion test open circuit potential (ocp) the open circuit potentials for coated and uncoated specimens by different surface coating materials are shown in figures (12) and (13). as the higher the ocp, the more resistance to corrosion, therefore the specimens were in the following sequence from most corrosion resistance to the lowest psz(cp ti= -0.212 v , ti-6al-4v =-0.265 v)> hap(cp ti= -0.225 v , ti-6al-4v =-0.40 v) >mixture(cp ti= -0.358 v , ti-6al-4v =-0.550 v)>uncoated (cp ti= -0.383 v , ti-6al-4v =-0.825 v). potentiodynamic polarization curves uncoated specimens figure (14) shows the higher polarization voltage (-0.332v ) and lower current density (3.11×10-5 a/cm2) of uncoated cp ti indicates better resistance to corrosion than uncoated ti6al-4v alloy which had lower polarization voltage (-0.465 v ) and higher current density (8.91×10-4 a/cm2). coated specimens the polarization curve of cp ti and ti-6al4v alloy coated with hap, psz and mixture of hap and psz are shown in figures (15) , (16), a-ti-6al-4v alloy coated with hap. b-ti-6al-4v alloy coated with psz. c-ti-6al-4v alloy coated with hap and psz. figure 11: optical micrograph view of ti-6al-4v alloy, a) ti-6al-4valloy coated with hap; b) ti-6al4valloy coated with psz; cti-6al-4v alloy coated with mixture of hap and psz at 500 um power after corrosion. 0.00 1000.00 2000.00 3000.00 4000.00 time (sec) -1.00 -0.80 -0.60 -0.40 -0.20 p ot en tia l ( v ) uncoated cp ti cp ti coated with ha cp ti coated with psz cp ti coated with ha and psz figure 12: open circuit potential for uncoated and coated cp ti with different coating materials. 0.00 1000.00 2000.00 3000.00 4000.00 time(sec) -0.60 -0.50 -0.40 -0.30 -0.20 po te nt ia l ( v ) uncoated ti-6al-4v ti -6al-4v coated with ha ti -6al-4v coated with psz ti -6al-4v coated with ha and psz figure 13: open circuit potential for uncoated and coated ti-6al-4v alloy with different coating materials j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 46 (17) respectively .the polarization curve of the coated cp ti specimens is higher than the coated ti-6al-4v alloy specimens. corrosion rate corrosion rate of cp ti and ti-6al-4valloy the corrosion behavior of implant materials (ti-6al-4v alloy and commercially pure titanium) was evaluated in this study by measuring the corrosion rate .different coatings were applied (hap, psz and mixture of hap and psz) on both alloys and comparison was done between them. the mean and standard deviation for all study groups are listed in table (1). all coated groups show lower corrosion rate than uncoated samples for cp ti and alloy. figure 18 shows summary statistics of corrosion rate parameter for coated and uncoated for the ti-6al4v alloy and commercially pure titanium in mmpy. coincidence’s tests for parameters (variances and means) showed highly significant difference among groups of cp ti and ti-6al-4v alloy samples as shown in the table(2). table 1: summary statistics (means and standard deviation) of corrosion rate parameter for coated and uncoated for the ti-6al-4v alloy and commercially pure titanium (mmpy) groups no. ti-6al-4v cp ti mean ×10-2 s.d. ×10-2 mean ×10-2 s.d. ×10-2 uncoated 8 2.94 ± 1.430 1.420 ±0.357 coating with hap 8 2.39 ± 0.471 0.437 ± 0.181 coating with psz 8 2.02 ± 0.852 0.363 ± 0.236 mixture of psz and hap 8 2.40 ± 0.330 0.998 ± 0.223 1.00e-10 1.00e-9 1.00e-8 1.00e-7 1.00e-6 1.00e-5 1.00e-4 log current density a/cm2 -1.20 -0.80 -0.40 0.00 0.40 0.80 po te nt ia l v (s c e ) tfel fit of potentiodynamic polarization of uncoated cp ti uncoated ti-6al-4v alloy 2 3 4 5 6789 2 3 4 5 6 789 2 3 4 5 6 789 2 3 4 5 6789 2 3 4 5 6 789 1.00e-8 1.00e-7 1.00e-6 1.00e-5 1.00e-4 1.00e-3 current density a/cm2 -1.20 -0.80 -0.40 0.00 0.40 0.80 po te nt ia l v (s c e ) tafel fit of potentiodynamic polarization of cpt coated with hap in simulated body fliud ti6al4v coated with hap figure 14: the polarization curves of uncoated cp ti and uncoated ti-6al-4v alloy. figure 15: the polarization curves of cp ti and ti-6al-4v alloy coated with hap. figure 16: the polarization curves of cp ti and ti-6al-4v alloy coated with psz. 2 3 4 5 6 789 2 3 4 5 6 789 2 3 4 5 6 789 2 3 4 5 6 789 2 3 4 5 6 789 1.00e-9 1.00e-8 1.00e-7 1.00e-6 1.00e-5 1.00e-4 current density a/cm2 -1.20 -0.80 -0.40 0.00 0.40 0.80 po te nt ia l v (s c e ) tafel fit of potentiodynamic polarization of cpt coated with psz ti6al4v coated with psz figure 17: the polarization curves of cp ti and ti-6al-4v alloy coated with hap and psz. 1.00e-9 1.00e-8 1.00e-7 1.00e-6 1.00e-5 1.00e-4 log density currenta/cm 2 -1.20 -0.80 -0.40 0.00 0.40 0.80 po te nt ia l v (s c e ) tafel fit of potentiodynamic polarization of cp ti coated with hap and psz in simulated body fliud ti-6al-4v alloy coated with hap and psz j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 47 groups m ixture 2 coating with zir. coating with hap 2 uncoated 2 m ixture 1 coating with zir. coating with hap 1 uncoated -1 m ea n of c or ro si on r at e m m py .04 .03 .02 .01 0.00 figure 18: bar chart plot for mean values of the corrosion rate of ti-6al-4v (1) alloy and cp ti (2) with different coatings table 2: coincidence’s tests for parameters (variances and means) between different treated materials according to the "corr. rate” parameter criteria test of homogeneity of variances (σ2) anovatest of equality of means (µ) levene's statistic sig. f-test sig. corrosion rate 12.333 0.000 17.711 0.000 (*) all coated groups of cp ti showed significantly lower corrosion rate when compared with uncoated groups. among the coated groups, coating with hap did not significantly differ from coating with psz, while there was a highly significant difference between the rest groups. all three types of ti-6al-4v alloy coating did not significantly differ from the uncoated alloy. coating of ti-6al-4v alloy with three coating materials showed significantly higher corrosion rate than all coated cp ti groups. discussion in this study the maximum corrosion rate was observed for ti-6al-4v alloy. there is a highly significant difference between corrosion of uncoated cp ti and uncoated ti-6al-4v alloy and this may be due to that the ti-6al-4v alloy is composed of different elements like al and v and to the more defective nature of grown passive layers and the increased reactivity of alloy which made the alloy with high corrosion also this may be due to the development of another type of corrosion like intercrystalline corrosion or another type of corrosion which can occur more frequently in the alloy than in the pure base metal similar to the result of (8). for coated cp ti groups the lowest corrosion rate is for cp ti samples coated with psz and those coated with hap, yet there is no significant differences between them, this may be due to powerful insulting effect of both coating materials which act as a barrier between the substrate surface (cp ti) and the solution of body fluid. also the effective bond between both coating and the surface of the substrate. coating with a mixture of hap and psz showed highly significant increase in corrosion rate compared to hap and psz alone, this might be due to some sort of incompatibility between these two materials as they are deposited together on the same surface. also it might be due to the difference in the coefficients of thermal expansion and contraction between hap and psz. during sintering procedure and cooling period this mismatch might create microcracks exposing the substrate surface to the solution and making corrosion rate the highest. all three types of coated ti-6al-4v alloy groups did not significantly differ from the uncoated alloy indicating the weak bonding of the coating to the surface of the alloy. in electrophoretic deposition charged particles are deposited on surface and as the alloy is composed of three main different elements ti, al and v each with different electromotive force so this might affect on the attraction of charged particles and the movement toward the alloy surface and then on bonding of the coating materials with the alloy therefore influence the thickness of the coating .the coating might be easily detached thus exposing the surface to the electrolyte solution. coating of ti-6al-4v alloy with three coating materials showed significantly higher corrosion rate than all coated cp ti groups which may be due to the weak bond established between the coating materials and the alloy surface .also due to the reduced thickness of the coating layer on the alloy than on the cp ti .coating the alloy with j bagh college dentistry vol. 26(3), september 2014 evaluation of corrosion restorative dentistry 48 psz reduced the corrosion rate; that made non significant differences between it and uncoated cp ti which may be due to the better adhesion of psz on the alloy compared to hap and the mixture. the open circuit potential for both cp ti and ti-6al-4v groups was in the following sequence from most corrosion resistance to the lowest psz(cp ti= -0.212 v , ti-6al-4v =-0.265 v)> hap(cp ti= -0.225 v , ti-6al-4v =-0.40 v) >mixture(cp ti= -0.358 v, ti-6al-4v =-0.550 v)>uncoated (cp ti= -0.383 v , ti-6al-4v =0.825 v). the parameter obtained for uncoated cp ti is higher than uncoated ti-6al-4v alloy and after coating. the corrosion rate of uncoated cp ti was less than uncoated ti-6al-4v alloy and after coating. the corrosion rate of cp ti was significantly reduced by coating with coating materials hap, psz, and mixture.the lowest corrosion rate was for cp ti coated with psz. the corrosion rate of ti-6al-4v alloy was insignificantly reduced by coating with each coating material and lowest corrosion rate was for ti-6al-4v coated with psz. references 1. the glossary of prosthodontic terms. j prosth dent 2005; 94(1): 10-92. 2. wetterhahn ke, demple b, knleszmartin m, copeland es. carcinogenesis a chemical pathology study section workshop, workshop report from the division of research grants. cancer res 1992; 52: 4058-63. 3. olmedo d, fernandez mm, guglidmotti mb, gabrini rl. macrophages related to dental implant failure. imp dent 2003; 12:75 -80. 4. alzubaydy tl, alameer ss, ismaeel t, al-hijazi ay. geetha m. in vivo studies of the ceramic coated titanium alloy for enhanced osseointegration in dental applications. j mater sci mater med 2009; 20: s35s42. 5. sridhar tm. synthesis, electrophoretic deposition and characterization of hydroxyapatite coatings on type 316l ss for orthodontic applications. ph.d.thesis, india, 2001. 6. zhitomirsky i. ceramic films using cathodic electrodeposition. j minerals metals and materials society 2000; 52 (1): 1-11. 7. animesh c, bikramjit b, balasubramaniam r. electrochemical behavior of ti-based alloys in simulated human body fluid environment" trends biomater. artif organs 2005; 18(2): 64-5. 8. chotiros k, yoshiki o, et al. electrochemical corrosion of titanium and titanium-based alloys" the j prosthet dent 2001; : 195-202. j bagh college dentistry vol. 28(4), december 2016clinical and sonographic 69 oral diagnosis clinical and sonographic changes of parotid gland in patients with type i and type ii diabetes mellitus and itseffect on physical properties of saliva rawaa a. a. al-ubaidy, b.d.s., m.sc. (a) rafil hameed rasheed, b.d.s., m.sc. (b) ahmed a. a. al-sabbagh, m.b.ch.b., f.i.c.m.s. (c) abstract background:sialosis is described as a specific consequence of diabetes. in diabetic sialosis, the increased volume of the glands is due to the infiltration of adipose in the parenchyma. the b-scan ultrasonography is a generally accepted tool for determining parotid gland enlargement. oral health is, to a greater extent, dependent on quality and quantity of saliva, both of which may be altered in diabetics. this study was conducted to detect the enlargement of parotid gland in diabetic patient and study the changes in physical properties of saliva and its relation with the salivary gland enlargement. subjects, materials and methods: this cross-sectional study included subjects of both sexes attending al-yarmouk teaching hospital (al-yarmouk center for diabetes), their ages ranged from20 to 65 years. parotid gland was measured by using b-mode ultrasonography with a high frequency (6-9mhz). the physical properties of saliva that were measured were flow rate, ph, and viscosity. results: the statistical analysis showed that: the right-left mean difference in length, width, depth and volume ultrasonography measurements of parotid gland among diabetic study group, revealed statistically non-significant difference, similar result was obtained among control group. the effect of diabetes mellitus is marked on the parotid gland measurements as the disease progresses and the hba1c increase. physical properties of saliva give obvious decrease in flow rate and ph in diabetic patient while the viscosity was increased in diabetic rather than normal. conclusion:this study concludes that there is positive correlation between the progressions of disease and salivary gland measurements. on the other hand, the present article shows that there is negative association between flow rate, ph, and viscosity in comparison with salivary gland measurements. key words:sialosis, parotid gland, diabetes mellitus, ultrasonography. (j baghcoll dentistry 2016; 28(4):96-102) introduction parotid gland (pg) is the largest of the major salivary glands (sgs) (1). sialosis can be described as a multifactorial disease of the salivary glands which is characterized by a painless bilateral growth. this growth is commonly seen in parotid gland and followed by a decreased salivary production which invariably leads to xerostomia. diabetes mellitus (dm) is probably the most frequent metabolic disease with salivary implication (2).diabetes is a widespread metabolic disease causing well-documented deleterious effects on the general health of an individual (3). multiple epidemiologic studies have suggested that diabetes is a risk factor for the development of oral disease in humans (4,5). about a third of diabetic patients complain of dry mouth (xerostomia) which may be due to overall diminished flow of saliva resulting from systemic dehydration and an increase in the salivary glucose level (6). (a)master student. department of oral diagnosis, college of dentistry, university of baghdad. (b)professor. department of oral diagnosis, college of dentistry, university of baghdad. (c)lecturer. al-yarmouk center for diabetes. ultrasound (us) high-resolution b-scan sonography has become an approved method in head and neck imaging. although widely used, no standard measurements for the sizes of parotid in b-scan sonography exist. it is a noninvasive investigation which uses a very high frequency (7.5mhz) pulsed us beams rather than ionizing radiation to produce high resolution images of more superficial structures (7).saliva is essential biological oral fluid which plays a crucial role in maintaining homeostasis of the oral cavity. oral health is to a greater extent dependent on quality and quantity of saliva, both of which may be altered in diabetics. this study was conducted to detect the enlargement of parotid gland in diabetic patients and study the changes in physical properties of saliva to the relation with the salivary gland enlargement. subjects and methods this cross-sectional study included 102 subjects attending al-yarmouk teaching hospital (al-yarmouk center for diabetes). the age range of the patients was 20-65 years. the total sample was divided into 3 groups: control group, study group1 with type i dm, study group 2 with type ii dm. j bagh college dentistry vol. 28(4), december 2016clinical and sonographic 69 oral diagnosis all patients with sialoadenosis caused by other endocrine diseases, nutritional disorders or neurogenic and sympathomemetic medications (8) were excluded from this study, also smokers and those subjects whose weight exceeded 20% of the ideal body weight (ibw) according to broca's formula ibw= (height-100) (9), were excluded. assessment of dm patients from normal 1. clinical assessment by specialist of endocrine diseases. 2. fasting plasma glucose (fpg) test: this test was done in (al-yarmouk center for diabetes) laboratory for study group and control group to ensure that all subjects in control group were free from disease. 3. glycosylated hemoglobin a1c test (hba1c): this test was performed for both study groups to assess the degree of control in diabetic patients. according to the american diabetes association ada (10), patients were considered to have an optimal diabetic control when the hba1c value did not exceed 7%, a moderate or acceptable control for values up to 7.9% while patients who had hba1c values of 8%-9.5% were considered to have poor control. ultrasound investigation of the parotid gland: a complete ultrasound b-scan investigation of the head and neck was done, using a modern ultrasound device (fukuda denshi) with a multifrequency transducer. the pg was measured according to the protocol set forth by dost (11) and bozzato(12)in length, width and depth. the length was measured in a transverse plane, the width in a ramus-parallel plane. the depth was recorded as the mean of the measured superficial and deep parts of the gland. distinctive features in the sonographic texture were also documented separately. the volume was determined by multiplying the length by width by mean of depth by the correction factor 0.8(12). gland volume = length (mm)×width (mm) × depth(mm) 8.0 × examination of physical properties of saliva: unstimulated whole saliva samples were collected by asking the subjects to refrain from eating, drinking or oral hygiene procedures for at least one hour before the collection. each subject was instructed to wash and rinse his mouth with water several times to ensure the removal of any possible food debris and contaminating materials and asked to accumulate saliva in their mouth by spitting into graduated glass tube. the salivary flow rate was calculated by dividing the volume of collected saliva (ml) by the time required for the collection in minute (1315)then the salivary ph was measured by ph meter (jenway 3320)and the viscosity of saliva measured by digital rotary viscometer(figure 1). statistical analysis data were translated into a computerized database structure. statistical analyses were done using spss version 21 (statistical package for social sciences). frequency distribution for selected variables was done first. the outcome quantitative variables in the current study were normally distributed variables and were therefore conveniently described by mean, sd (standard deviation) and se (standard error), and the parametric statistical tests of significance were used. the independent samples t-test was used to test the statistical significance of difference in mean between 2 groups. anova test was used to test the statistical significance of difference in mean between more than 2 groups. furthermore, when anova model showed statistically significant differences, further exploration of the statistical significance of difference in mean between each 2 groups was assessed by lsd (least significant difference). anova trend was used when the grouping variable was an ordinal level variable. the statistical significance of mean paired differences between right and left side measurements was assessed by paired t-test. the cv% (coefficient of variation) measures the magnitude of variation in the measurements between the 2 sides. the variability (sd) of these errors are evaluated for magnitude by comparing its value to the mean or original readings cv% = (sd of errors (paired differences) / mean of original measurement) x 100 results the present study showed that there were nonsignificant statistical differences in pg measurements between the right and left sides in all dimensions and volume indicating that the enlargement was bilateral and symmetrical. in us the glands appeared homogenous with fatty infiltration that makes it hyperechoic in texture for patients with long duration of disease or poorer control dm. in doppler there was no vascular changes that confirm its noninflammatory condition. j bagh college dentistry vol. 28(4), december 2016clinical and sonographic 69 oral diagnosis figure 1: uss-dvt4 digital rotary viscometer the effect of dm on physical properties of saliva there was marked decrease in salivary flow rate and ph regardless the type of diabetes mellitus type i or ii in comparison with normal, while the viscosity increased in study groups more than normal (table1). the effect of dm on salivary gland volume: as shown in table 2, the mean salivary gland volume (sgv) was highest in type ii dm (20.6ml) and lowest in healthy control (hc) (8.2ml). the difference in mean between 3 groups was significant statistically with (p<0.001). having type ii dm is expected to significantly increase the sgv by 3.9 ml compared to type i, which is significant statistically. this effect was strong (cohen's d >2.4). the association between the physical properties of saliva with the sg measurements in: 1-type i dm: 1. salivary flow rate: the correlation was very weak between the salivary flow rate and the sg measurements (table 3). 2. ph: the correlation was very weak between the salivary ph and the sg measurements(table 3). 3. salivary viscosity: the viscosity was increased in diabetic patient, the viscosity of saliva had a very weak linear correlation statistically with the enlargement of the gland a as shown in table 3. 2-type ii dm: 1. salivary flow rate: the correlation was very weak between the salivary flow rate and the sg measurements and it is statistically nonsignificant (table 4). 2. ph: the correlation was very weak between the salivary ph and the sg measurements that are non-significant statistically (table 4). 3. salivary viscosity: the viscosity was increased in diabetic patient but this elevation in viscosity is not correlated with theenlargement of the gland statistically in a non-significant correlation (table 4) table 1: the effect of dm on physical properties of saliva study group variables healthy controls n=34 casestype-i dm n=34 casestype-ii dm n=34 p (anova) salivary flow rate (ml/min) <0.001 range (0.3-0.5) (0.05-0.3) (0.05-0.3) mean 0.4 0.14 0.17 sd 0.05 0.07 0.07 se 0.008 0.012 0.012 salivary ph <0.001 range (6.75-8.1) (5.5-7.25) (5.25-7) mean 7.54 6.14 6.3 sd 0.37 0.51 0.48 se 0.064 0.087 0.082 salivary viscosity <0.001 range (0.95-1.63) (1.2-3.5) (1.07-2.6) mean 1.24 1.93 1.73 sd 0.18 0.52 0.45 se 0.031 0.089 0.077 j bagh college dentistry vol. 28(4), december 2016clinical and sonographic 66 oral diagnosis table 2: the effect of diabetes mellitus on salivary gland volume measurements discussion right and left difference in parotid gland us measurements this study showed that there were no statistical significant differences in pg volume between the right and left sides indicating that the enlargement was bilateral and symmetrical, this is in agreement with many studies (16-21) where they reported that, sialadenosis in the pg is usually bilateral and symmetric but can be unilateral and/or asymmetric. effect of dm on salivary parameters and its correlation with sialadenosis lasisi and fasanmade showed that diabetic patient had significant reduction in salivary flow rate when compared with nondiabetic individuals (22) which is compatible with the present article radhike and ranganathan maintained that whole unstimulated and stimulated salivary flow rates were decreased in diabetic compared to nondiabetics and this difference was statistically significant (p=0.00)(23). this finding was constant with other findings (24-28) which is in line with this study. however, the results reported by lasisi etal. marder et al., dodds et al. and collin et al.(22,2931)showed no significant reduction in salivary flow rate in diabetes compared to non-diabetics, which is in contrast to the present study. in a study by moreira (32), salivary parameters of flow rate and ph were decreased, and it was concluded that the decrease in salivary ph is certainly due to decrease in unstimulated salivary flow. in the present study, the us of the parotid glands appear homogenous with fatty infiltration that makes it hyperechoic in texture of patient with long duration of disease or poor control dm. in doppler there were no vascular changes that confirm its non-inflammatory condition. the normal pg appears homogenous and of increased echogenicity relative to the adjacent muscle on us. the increase echogenicity is related to the fatty glandular tissue composition of the gland (33-35). in conclusion this study shows that there is positive correlation between the progressions of disease and salivary gland measurements, it also demonstrates that there is negative association between flow rate, ph, and viscosity of saliva in comparison with salivary gland measurements. study group p (anova) healthy controls cases-typei dm cases-type-ii dm salivary gland volume (ml) mean of r and l side <0.001 range (5 to 12.5) (7 to 29.4) (9.9 to 35.7) mean 8.2 16.7 20.6 sd 1.7 6.5 7.1 se 0.29 1.12 1.22 n 34 34 34 range of normal values (5th-95th centile) (5 to 11.4) effect of dm compared to healthy controls p (lsd) <0.001 <0.001 difference in mean 8.5 12.4 cohen's d 1.79 2.4 effect of type-ii dm compared to type-i dm p (lsd) 0.005 difference in mean 3.9 cohen's d 0.57 j bagh college dentistry vol. 28(4), december 2016clinical and sonographic 011 oral diagnosis table 3: the association between the physical properties of saliva with the sg measurements in type i dm salivary flow rate (ml/min)-categories (dm) type-i dm first (lowest) quartile (<=0.1) average (inter-quartile range) 0.11-0.19 fourth (highest) quartile (0.2+) p (anova trend) salivary gland volume (ml) mean of r and l side 0.63[ns] range (7 to 29.4) (9.7 to 27) (9.6 to 28.9) mean 16.5 19.4 15.3 sd 7.1 6.9 5.3 se 1.77 2.62 1.6 n 16 7 11 r=-0.076 p=0.67[ns] salivary ph-categories (dm) type-i dm first (lowest) quartile (<=5.75) average (inter-quartile range) 5.8-6.49 fourth (highest) quartile (6.5+) p (anova trend) salivary gland volume (ml)mean of r and l side 0.53[ns] range (7.2 to 28.8) (12.8 to 29.4) (7 to 27) mean 14.2 19.2 16 sd 6.5 6.1 6.4 se 1.95 1.64 2.12 n 11 14 9 r=0.013 p=0.94[ns] salivary viscosity-categories (dm) type-i dm first (lowest) quartile (<=1.48) average (inter-quartile range) 1.5-2.19 fourth (highest) quartile (2.2+) p (anova trend) salivary gland volume (ml)mean of r and l side 0.033 range (7 to 29.4) (9.6 to 27) (7.2 to 18.8) mean 19.6 17.8 13.2 sd 8.6 6.3 3.2 se 3.04 1.63 0.96 n 8 15 11 r=-0.329 p=0.06[ns] j bagh college dentistry vol. 28(4), december 2016clinical and sonographic 010 oral diagnosis table 4: the association between the physical properties of saliva with the sg measurements in type ii dm salivary flow rate (ml/min)-categories (dm) type-ii dm first (lowest) quartile (<=0.1) average (inter-quartile range) 0.11-0.19 fourth (highest) quartile (0.2+) p (anova trend) salivary gland volume (ml)mean of r and l side 0.82[ns] range (11.3 to 23.8) (11.4 to 35.7) (9.9 to 32.5) mean 19.3 22.7 20.1 sd 4.1 9 7.4 se 1.35 2.83 1.91 n 9 10 15 r=-0.04 p=0.82[ns] salivary ph-categories (dm) type-ii dm first (lowest) quartile (<=5.75) average (inter-quartile range) 5.8-6.49 fourth (highest) quartile (6.5+) p (anova trend) salivary gland volume (ml)mean of r and l side 0.87[ns] range (9.9 to 31.7) (10 to 28) (11.3 to 35.7) mean 20.8 19.2 21.3 sd 6.8 6.5 7.8 se 2.58 2.17 1.84 n 7 9 18 r=-0.027 p=0.88[ns] salivary viscosity-categories (dm) type-ii dm first (lowest) quartile (<=1.48) average (inter-quartile range) 1.5-2.19 fourth (highest) quartile (2.2+) p (anova trend) salivary gland volume (ml)mean of r and l side 0.76[ns] range (12.6 to 32) (9.9 to 35.7) (11.3 to 31.7) mean 19.6 21.3 20.6 sd 6.4 8.2 6.3 se 2.02 2.06 2.24 n 10 16 8 r=-0.01 p=0.96[ns] references 1. snell rs. clinical anatomy. 8thed. baltimore: lippincott williams &wikins; 2007. 2. mata ad, marques d, rocha s, francisco h, santos c, mesquita mf, singh j.effects of diabetes mellitus on salivary secretion and its composition in human. molecular and cellular biochemistry 2004; 2: 137-42. 3. nechifor m, teslariu e, mindrecii.the influence of magnesium, chromium and copper in alloxan– induced diabetic 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ultrasonographic biometry in salivary glands. ultrasound med biol1997; 23(9):1299–303. 12. bozzato a, burger b, zenk j, uter w, iro h. salivary gland biometry in females patient with eating disorders. eur arch otorhinolaryngol2008; 256(9):1095-102. j bagh college dentistry vol. 28(4), december 2016clinical and sonographic 011 oral diagnosis 13. herrera j, lyons m, johnson l. saliva: its role in health and disease. j clincastoenterol 1990; 10:56978. 14. ahmed rf.the effect of oral contraceptive pills intake onbiochemical composition and secretion on lyophilize saliva. a master thesis. department of oral diagnosis, college of dentistry, university of baghdad, 2006. 15. mudher sh.saliva and blood analysis in relation to oral and salivary findings.a master thesis. department of oral diagnosis, college of dentistry, university of baghdad, 2008. 16. ida m, hunda e. age dependent in the computed tomographic numbers of parotid and submandibular glands. dentomaxillafacradiol 1989; 18(1):31-5. 17. ariji y, ariji e, araki k, nakamura s, kanda s. studies on quantitative computed tomography of normal parotid and submandibular salivary glands. dentomaxillofacradiol 1994; 23:29-32. 18. medbery r, yousem dm, needham mf and kligerman m. variation of parotid gland size, configuration, and anatomic relations. radiotherapy oncol 2000; 54: 87-9. 19. som pm, curtin hd. head and neck imaging. 4th ed. philadelphia: mosby. an affiliate of elsevier; 2003.pp. 2007-2011. 20. dubrulla f, souillard r. parotid gland and other salivary glands tumors. in: head and neck cancer imaging. berlin/ heidelberg newyork. springer; 2006. pp. 219-20. 21. al-ghurabi zh, fattah aa. ultrasonographic measurements of parotid gland among poorly controlled type 2 diabetes mellitus iraqi females sample. j baghcoll dentistry 2010; 22(3): 52-6. 22. lasisi tj, fasanmade aa. comparative analysis of salivary glucose and electrolytes in diabetic individuals with periodontitis.annibdpgmed 2012; 10:25-30. 23. radhike t, ranganathan k. salivary output in type 2 diabetic patients. oral maxillofacpathol j 2014; 5(1): 413-7. 24. chavez em, taylor gw, borrell ln, ship ja. salivary function and glycemic control in older persons with diabetes. oral surg oral med oral pathol oral radiolendod2000; 89(3): 305-11. 25. kadir t, pisiriciler r, akyuz s, yarat a, emekli n, ipbuker a. mycological and cytological examination of oral candida carriage in diabetic patients and nondiabetic control subjects: analysis of local aetiologicand systemic factors. j oral rehabil 2002; 29: 452-7. 26. bernardi mj, reis a,loguercio ad,kehrig r, leite mf, nicolau j. study of the buffering capacity, ph and salivary flow rate in type 2 well-controlled and poorly controlled diabetic patients. oral health prev dent 2007;5: 73-8. 27. vaziri bp, vahedi m, mortazavi, abdollahzadeh sh, hajilooi m. evaluation of salivary glucose, iga and flow rate in diabetic patients: a case-control study. j dent (tehran)2010; 7:13-8. 28. jawed m, shahid sm, qader sa, azhar a. dental caries in diabetes mellitus: role of salivary flow rate and minerals. j diabetic complications 2011; 25:1836. 29. marder mz, abelson dc, mandel id.salivary alterations in diabetes mellitus.jperiodontol1975;46: 567-9. 30. dodds mw, dodds ap. effects of glycemic control on saliva flow rates and protein composition in noninsulin-dependent diabetes mellitus. j oral surg oral medoral patholoral radiolendod 1997; 83: 465-70. 31. collin hl, niskanen l, uusitupa m, toyry j,koivisto am, viinamaki h. oral symptoms and signs in elderly patients with type 2 diabetes mellitus. oral surg oral med oral pathol 2000; 90:299-305. 32. moreira ar, passos ia, sampaio fc, soares ms, oliveira rj. flow rate, ph and calcium concentration of saliva of children and adolescents with type 1 diabetes mellitus. braz j med biol res 2009; 42: 70711. 33. thoron jf, rafaelli c, carlotti b. ultrasonography of the parotid venous plane in french. j radiol 1996; 77: 667-9. 34. rabinov jd. imaging of salivary gland pathology.raqdiolclin north am 2000; 38:1047-57. 35. howlett dc. high resolution ultrasound assessment of the parotid gland. br j radiol2003; 76: 271-7. 19. talib f.doc j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 119 an evaluation of serum and salivary adipokines (leptin and resistin) levels in periodontal health and disease talib ali karam, b.d.s. (1) khulood a. al-safi, b.d.s., m.sc., ph.d. (2) abstract background: with the start of the current century, increased the interest in the role of the adipose tissue derived substances that named adipokines in the inflammatory diseases of the human being including the inflammatory periodontal disease, but scientific evidences were not clearly demonstrate the association between these adipokines and periodontal pathologies. materials and methods: forty two subjects male only with normal body mass index were selected for the study with an age ranged (30-39 years). samples were divided into three groups of 14 subjects in each group based on clinical periodontal parameters; clinically healthy gingiva (group i), gingivitis group (group ii) and chronic periodontitis patients group (group iii), from whom saliva and serum samples were collected for estimating the levels of leptin and resistin using enzyme-linked immuno sorbent assay (elisa). results: the results showed that the serum level of leptin and resistin were significantly higher in chronic periodontitis patient (9.81 ng/ml, 6.55 ng/ml) respectively as compared to gingivitis and healthy control groups (leptin; 8.10 ng/ml, ng/ml, resistin; 5.85 ng/ml, 5.45 ng/ml) respectively. on the other hand the level of leptin in saliva of patients with chronic periodontitis (0.17 ng/ml) was significantly lower than that of its salivary levels in gingivitis and healthy control groups (0.21 ng/ml, 0.29 ng/ml) respectively. whereas, salivary resistin levels was significantly higher in chronic periodontitis patient(14.45 ng/ml) when compared to the gingivitis group (11.59 ng/ml) and the health control group (6.43 ng/ml). conclusions: concomitant raise in serum leptin, serum resistin and salivary resistin, while a sensible reduction in salivary leptin with conversion from periodontal health state to periodontal disease state. these finding may draw a suggestion on the role of leptin and resistin in the relation between periodontal disease and the systemic health since the increase in their level were associated with a various systemic pathologies. keywords: adipocytokine, leptin, resistin, periodontal disease. (j bagh coll dentistry 2015; 27(4):119-124). introduction periodontal disease is a chronic microbial and inflammatory process characterized by the presence of sulcular pathogenic bacteria, impaired host immune response and destruction of the connective tissue attachment (1). biochemical signaling involving three biological phases (inflammation, connective tissue degradation and alveolar bone turnover) contributes to the clinical morbidity observed in the affected tissues, in these biological phases, circulating molecules have been detected at elevated levels in the whole saliva and gingival crevicular fluid (gcf) of patients with periodontal disease making them putative biomarkers of the disease (2-4). it has been proposed that appropriate cytokine production results in protective immunity, while inappropriate cytokine production leads to tissue destruction and disease progression (5). adipose tissue participates in the regulation of energy homeostasis and is an active endocrine organ that secretes more than 50 biologically active substances, collectively termed adipokines. adipokines such as the hormone-like proteins: leptin, resistin and adiponectin (6). (1) master student. department of periodontics, college of dentistry, university of baghdad. (2) professor, department of periodontics, college of dentistry, university of baghdad. leptin is a non-glycosylated peptide hormone that has been classified as a cytokine as it shows structural similarities to the long chain helical cytokine family interleukin (il)-6 (7). ahima and flier suggested that leptin orchestrates the host response to infectious and inflammatory stimuli as it stimulates the immune system by enhancing pro-inflammatory cytokine production and phagocytosis by macrophages (8). it was shown that leptin synthesis is increased by a number of inflammatory stimuli, including interleukin (il)-1, il-6, tumor necrosis factor alfa (tnf-α), and lipopolysaccharid (lps) (9). as the gingival disease progressed, there is significant decrease in the gingival leptin concentration, gcf leptin concentration and significant increase in the plasma leptin concentration (10,11). resistin is a polypeptide hormone that is expressed abundantly in adipose tissues of mice; however, in humans, resistin is expressed at very low levels in adipocytes (12). human resistin acts as a pro-inflammatory molecule and stimulates the synthesis and secretion of tnf-α and interleukin (il-12) (13). in addition to tnfα and il-6, resistin may participate in inflammatory processes caused by bacterial infections(14). periodontitis was significantly associated with increased levels of resistin, after adjustment for gender, smoking, fasting glucose, and body mass index (bmi) (15,16). j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 120 potential role for resistin in bone metabolism was suggested by increased resistin levels that coincided with osteoclast differentiation (17). this study aimed to evaluate the salivary and serum levels of leptin and resistin in periodontal health and disease (individuals with clinically healthy gingiva, gingivitis and chronic periodontitis). materials and methods a total of 42 males with normal body mass index according to who criteria were participated in the study. they were divided into three groups, based on clinical examination according to gingival index (gi), probing pocket depth (ppd), clinical attachment level (cal). group i (control group): fourteen individual with clinically healthy gingiva, and this was defined by gi scores (<0.7) and with no periodontal pocketing or attachment loss. for standardization of biochemical parameters. group ii gingivitis patient: fourteen individual with gingivitis, and this was defined by gi scores (>0.7) and with no periodontal pocketing or attachment loss. group iii chronic periodontitis: fourteen patients with chronic periodontitis, and this was defined by the presence of at least four sites with ppd (≥4mm ) with cal ( ≥1mm). all participants were instructed not to eat or drink (except water) at least 1 hour prior to collection of saliva. the subject should sit in a relaxed position. samples were collected between 9-12 am. after the subject rinse his mouth several times by bottled water and then wait for 1-2 minutes for water clearance, 5ml of whole unstimulated mixed saliva was collected into polyethylene tubes. saliva should not be spat into the tube and samples containing blood were discarded, also the patient shouldn't swallow during the. saliva then centrifuged at 4000 round per minute (rpm) for 15 minutes; this was done within one hour after collection to eliminate debris and cellular matter, the clear supernatant was separated by micropipette and transferred to eppendorf to be stored at (-20 ºc) till being analyzed. four ml of blood was collected from the antecubital fossa by venipuncture using 5 ml disposable syringes and immediately transferred to lab. samples were collected between 9-12 am. blood sample was allowed to clot at room temperature and after one hour, serum was extracted from blood by centrifuging at 3000 rpm for 5 min. the extracted serum was immediately transferred to eppendorf and stored at (-20 ºc) till being analyzed. the demeditec leptin and resistin enzyme linked immuno sorbent assay (elisa) kits were used for quantitative measurement of their serum and salivary levels. oral examination was done using periodontal probe on all teeth except 3rd molar on four surfaces. the collected data include: plaque index system, gingival index, bleeding on probing, probing pocket depth and clinical attachment level. results the standard deviation (sd), standard error (se), minimal (min.) and maximal (max.) values were obtained for each group. anova table test was performed for analysis of variance. the study had revealed that there is a highly significant difference in serum leptin levels at p< 0.01 among the studied groups as shown in table (1) and with mean value of (5.61) in group i, (8.10) in group ii and (9.81) in group iii. table (1): serum leptin levels (ng/ml) among three studied groups. group1group2group3p-value mean 5.61 8.10 9.81 0.000 ** s.d. 1.19 0.97 1.15 s.e. 0.32 0.26 0.31 min. 4.07 6.54 8.34 max. 7.71 9.81 11.64 ** highly significant difference at p<0.01. table (2) showed that the mean salivary leptin in group i had the largest value (0.29 ng/ml) followed by group ii (0.21 ng/ml ) and the group iii had the smallest value (0.17 ng/ml) and also it revealed that there is highly significant difference between mean salivary levels at p< 0.01. table (2): salivary leptin levels (ng/ml) among three studied groups. group1group2group3p-value mean 0.29 0.21 0.17 0.000 ** s.d. 0.04 0.04 0.04 s.e. 0.01 0.01 0.01 min. 0.22 0.13 0.10 max. 0.36 0.27 0.23 ** highly significant difference at p<0.01. there is a significant difference in mean serum resistin levels at p<0.05 with highest mean value in chronic periodontitis patient (group iii) (6.5 ng/ml) and lowest mean value in healthy control group (group i) (5.45ng/ml) that was seen in table (3). j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 121 table (3): serum resistin levels (ng/ml) among three studied groups. group1group2group3p-value mean 5.45 5.85 6.55 0.032 * s.d. 0.60 0.97 1.45 s.e. 0.16 0.26 0.39 min. 4.70 4.37 4.71 max. 6.30 7.50 8.85 *significant difference at p<0.05. periodontitis individuals presented the lowest serum leptin levels than periodontitis patients and stating that periodontitis affected the circulating levels of leptin in favor of pro-inflammation (19). a recent study have stated that serum level of leptin was significantly higher in chronic periodontitis patients when compared to healthy controls suggesting that chronic periodontitis upregulated the circulating level of leptin in subjects with normal bmi (20). there was an association of periodontal conditions with serum leptin levels, since its levels was influenced by (21). regarding salivary level of resistin the present study revealed that the level of salivary resistin in chronic periodontitis group (14.45) was significantly higher at p<0.01 than the other two groups with lowest level in healthy group (6.43), lps stimulation in human. controversy was also seen in regard to association between circulating leptin and periodontitis as the result of this was disagreed with davies et al who stated that the level of serum leptin was not significantly different between the aggressive periodontitis patients (22). all that was shown in table (4). healthy subjects a recent study has pointed out that serum levels of leptin and soluble leptin receptor do not vary between patients and with different periodontal conditions (23). the possible explanation for this is due to the fact that porphyromonas gingivalis (p. gingivalis) which is a g -ve bacterium found in periodontal pockets of patients with periodontitis and strongly implicated in the pathogenesis of periodontal disease (24,25). table (4): salivary resistin levels (ng/ml) among three studied groups. group1group2group3p-value mean 6.43 11.59 14.45 0.000 ** s.d. 0.81 1.60 1.88 s.e. 0.22 0.43 0.50 min. 4.63 8.65 11.60 max. 7.89 13.77 17.84 ** highly significant difference at p<0.01. discussion lipopolysaccharide (lps) is virulent factor of the bacterium leading to the development of inflammatory responses that characterize periodontitis (26). leptin significantly enhanced p. gingivalis lps induced il-18 release suggesting a possible interaction between leptin and periodontal bacteria in modulating host (27). interestingly, this study had showed that the immune responses. leptin was shown to circulating level of leptin in serum was correlated positively with transition from periodontal health to disease. many researchers have studied the relation of leptin to various forms of periodontal disease using different types of samples their results seemed to be in enhancing toll like receptor (tlr) expression and the secretion of cytokines in monocytes and may thereby potentiate immune responses to periodontal pathogens (28). there are significant differences between leptin action in the circulation and locally within (29) accordance to a certain degree with the result of the gastrointestinal lumen. studies suggested the present study. this is in agreement with a study done by gangadhar and his colleagues who declared that the serum leptin concentrations were found to increase as the gingival disease progressed (11). it also in agreement with karthikeyan and pradeep who suggest that greater the periodontal destruction, greater is the serum leptin concentration and the lowest serum leptin concentration was found in healthy individuals (10). a multifunctional role of leptin released locally within peripheral tissues and that secreted into saliva by the acinar cells of salivary glands, have brought to the forefront its importance in the processes of mucosal defense and repair along alimentary tract, including that of oral cavity and gingiva as salivary leptin potently stimulate the expression of two cytokines relevant to keratinocyte proliferation, salivary leptin increases proliferation of oral keratinocytes (30-32). the present study come in line with shimada et, al., who found that there was a significant sublingual salivary gland acinar cells against (33) differences between healthy and chronic ethanol cytotoxicity, that exogenous leptin periodontitis patients in serum leptin levels (18). on other hand, zimmermann et, al., showed that non-known to accelerate wound repair, it contributes to the inhibition of bacterial growth by mucins, since it prevents the reduction of salivary mucin synthesis evoked by oral bacterial lps, that gingival leptin was known for its protective role in periodontal disease (34-39). j bagh college dentistry vol. 27(4), december 2015 antibacterial effect oral and maxillofacial surgery and periodontics 122 moreover, the result of the present study showed that there is a highly significant difference in mean salivary leptin levels among the studied groups at p< 0.01, with group i had the highest value and the group iii had the lowest one. this in contrast to what we have found in relation to circulatin leptin level, but these finding be consistent with a study by ducroc et, al., as they showed that there are significant differences between leptin action in the circulation and locally within the gastrointestinal lumen (29). little information was known about the association between salivary leptin level and periodontal disease. though a study showed that there were no differences in the distribution of leptin single nucleotide polymorphism (-2548g/a snp) genotypes (leptin genetics) in saliva of 50 subjects between control and periodontitis subjects (40). in regards to circulating resistin the result of the present study illustrated that there was a significant difference in mean serum resistin levels with highest mean value in chronic periodontitis patient and the lowest mean value in healthy control. these consequences were in accordance with a japanese study which declared that increased serum resistin levels were significantly associated with periodontal condition in elderly people (15). also it matched with zimmermann and colleagues who found that serum resistin level was higher in periodontitis than in non-periodontitis (19). coming in line with another japanese study which stated that having periodontitis was significantly associated with an increased level of serum resistin (16). recently, duarte et, al., have found that serum levels of resistin were significantly higher in chronic periodontitis subjects when compared to healthy controls. suggesting that chronic periodontitis upregulated the circulating levels of resistin in subjects with normal bmi (20). even though there were number of researchers have disagreed in part or as whole with our findings. there was not much difference in the serum resistin levels between the chronic periodontitis and the healthy controls. also the decrease in the resistin levels following nonsurgical periodontal therapy did not show any statistical significance(41). serum resistin levels have not presented any significant differences between the periodontally healthy and ligature induced periodontitis in rats(42). resistin concentrations in serum was not associated with periodontitis (43). this rise in serum resistin in periodontal disease can be explained logically in the context of the following studies which showed that circulating resistin concentration was increased in response to lps and/or leukotoxin that were produce by common peridontopathic bacteria; inflammatory cells such as monocytes and macrophages present in the periodontal tissue appear to be the major source of resistin (15). resistin release from neutrophils was induced by both p. gingivalis and escherichia coli (e. coli) lps(44). increased resistin in several inflammatory cells stimulated by periodontal pathogenic components such as lps(45). there was an association of periodontal conditions with serum resistin levels, since its levels was dramatically increased by lps stimulation in humans (21,46-49). furugen et al showed that a. a expressed leukotoxin that induces extracellular release of human neutrophil derived resistin and suggested that increased prevalence and levels of a. a in periodontal patients contribute to their higher circulating levels of resistin (50). moreover, resistin was shown to mediate its proinflammatory effects via tlr-4 (51). the expression level of tlr-4 was higher in all periodontal patients than in healthy individuals(52). there was no data provided in the surveyed periodontal literature regarding local level of resistin in saliva of patients with periodontal disease. even though, a number of studies have investigated the local resistin in gcf but not in the gingival tissue. the present study revealed that the level of salivary resistin in chronic periodontitis group was significantly higher than the other two groups with lowest level in healthy control group and that of gingivitis group was intermediate between them. the level of salivary resistin were upregulated locally in the salivary glands in case of inflammation in patient with primary sjögren's syndrome; and the levels of resistin correspond to the intensity of lymphocytic inflammation (53). based on this fact we may explain and illustrate that the salivary resistin were upregulated locally in the salivary glands in relation to inflammation caused be the inflammatory periodontal diseases. references 1. faizuddin m, bharathi sh, rohini nv. estimation of interleukin-1beta levels in the gingival crevicular fluid in health and in inflammatory periodontal disease. j periodontal res 2003; 38(2): 111-4. 2. lamster ib, kaufman e, grbic jt, et al. betaglucuronidase activity in saliva: relationship to clinical periodontal parameters. j periodontol 2003; 74: 353-9. 3. miller cs, king cp jr, langub mc, et al. salivary biomarkers of existing periodontal disease: a crosssectional 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demographic information (age and gender), the site of the tumor, the clinical manifestations, the histological type of the tumor, the type of the treatment and the postoperative complications. results: fifty seven patients were included in this study. the parotid gland was involved in most patients (n=37, 64.9%). thirty five patients (61.4%) had benign tumors while 22 patients (38.6%) had malignant tumors. the mean age of patients with malignant tumors was 52.05 (±17.3) while of patients diagnosed with benign tumors was 41.6 (±11.4) years, the difference was statistically significant (p= 0.008). surgical treatment consisted of superficial parotidectomy, total parotidectomy, surgical excision of the submandibular gland, surgical excision of minor salivary glands and maxillectomy. the most common complication was weakness of one or multiple branches of the facial nerve, complications were significantly associated with patients’ age, whereas gender and type of tumor whether benign or malignant did not affect the complication rate conclusions: benign salivary gland tumors are more common than malignant tumors with no gender predilection and that patients who are diagnosed with malignant tumors are significantly older that patients with benign tumors, parotid gland is the most commonly affected gland with pleomorphic adenoma as the most frequent diagnosis. facial nerve dysfunction was the most common complication and the complication rate was significantly associated with the age of patients. key words: outcome; salivary gland tumors; surgical treatment. (received: 7/1/2019; accepted 10/2/2019) introduction salivary gland neoplasms constitute 210% of all head and neck neoplasms; they consist of a group of heterogeneous lesions with complex clinicopathologic characteristics and distinct biological behavior. (1, 2) salivary gland tumors are divided into epithelial and non-epithelial as well as into benign and malignant tumors, spiro in 1986 (3) in a study of 2807 patients reported that 25% of parotid tumors, 43% of submandibular gland tumors and 82% of minor salivary gland tumors were malignant. in a recent study of 7190 chinese patients, malignant parotid, submandibular, sublingual and minor salivary gland tumors were reported in 22.26%, 35.76%, 92.97%, and 61.89% of the cases respectively. (4) (1)board student, oral and maxillofacial surgery unit, ghazi al-hariri hospital for surgical specialties (2)assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. studies have shown that the parotid gland is the most common site of occurrence ranging from about 60% to 70% of the cases followed by minor salivary glands (22%-24%), whereas 8% to 10% of these tumors involve the submandibular gland. the least common site for these tumors is the sublingual gland with a percentage ranging from less than 1% to about 2.5%. (3-5) numerous studies from different regions of the world have been published concerning the incidence and the histological types of salivary gland tumors and geographical variation has been suggested, (1, 6) therefore the aims of this study were to analyze the characteristics of salivary gland neoplasms in two iraqi centers and to analyze the postoperative complications that are encountered after surgical treatment of these tumors. materials and methods the medical records of the patients who were treated for major and minor salivary gland tumors at the oral and maxillofacial surgery units of al-yarmouk teaching hospital and j bagh college dentistry vol. 31(3), september 2019 salivary gland tumors 35 ghazi al-hariri hospital for surgical specialties during the period from march 2016 to september 2017 were retrospectively reviewed. diagnosis was based on history, clinical examination, imaging which included ultrasonography, ct scans and mri and other investigations such as fine needle aspiration biopsy (fnab) and incisional biopsy which was performed for minor salivary gland tumors. patients who were diagnosed with non-epithelial tumors were excluded from this study. the retrieved and analyzed data included; demographic information (age and gender), the site of the tumor, the clinical manifestations, the histological type of the tumor, the type of the treatment and the postoperative complications. statistical analysis was performed using graphpad prism version 6 for windows (graphpad software, la jolla, ca, usa). for descriptive analysis percentages and mean ± standard deviation (sd) were recorded. the data were analyzed statistically using student t-test, chi square test or fischer’s exact test. the difference was considered significant at p<0.05. results fifty seven patients with an age range of 20-85 years and a mean age (± sd) of 45.4 (± 14.6) years were enrolled in this study. the patients consisted of 29 (50.9%) males and 28 (49.1%) females. the mean age (± sd) of males was 46.97 (± 13.95) and of females was 43.68 (± 15.32), the age difference between both genders was statistically not significant (p= 0.4). the parotid gland was involved in most of the patients (n=37, 64.9%), followed by minor salivary gland (n=17, 29.8%) and submandibular glands (n=3, 5.3%). parotid tumors swelling was the most common clinical presentation; it was manifested in all patients (100%). seven patients (12.3%) showed facial nerve weakness of one or multiple branches of the facial nerve and in 8 patients (14%) there was tethering of the tumor to the overlying skin. thirty five patients (61.4%) were diagnosed with benign tumors (24 in the parotid, 3 in the submandibular and 8 in the minor salivary glands) while 22 patients (38.6%) had malignant tumors (13 in the parotid and 9 in the minor salivary glands); the histological types of the tumors are summarized in (table 1). table 1: histological types of the benign and malignant tumors histological types of the tumors number of patients (n=57) % benign tumors (n=35) pleomorphic adenoma 31 54.4 oncocytoma 2 3.5 basal cell adenoma 2 3.5 malignant tumors (n=22) mucoepidermoid carcinoma 9 15.8 adenoid cystic carcinoma 5 8.8 acinic cell carcinoma 5 8.8 ductal carcinoma 2 3.5 low grade polymorphous adenocarcinoma 1 1.7 the mean age of patients who were diagnosed with malignant tumors was 52.05 (±17.3) years compared with the mean age of patients diagnosed with benign tumors which was 41.6 (±11.4) years, the difference was statistically significantly (p= 0.008). with respect to the differences in gender distribution and site of tumors the results were statistically not significant (table 2). table 2: distribution according to gender and site of tumors in patients with benign and malignant tumors variables benign tumors (n=35) malignant tumors (n=22) p value gender 0.2829 * [ns] male 20 (69%) 9 (31%) female 15 (53.6%) 13 (46.4%) site of the tumor major salivary glands 27 (67.5%) 13 (32.5%) 0.2338 * [ns] minor salivary gland 8 (47%) 9 (53%) * fishers exact test, ns: not significant j bagh college dentistry vol. 31(3), september 2019 salivary gland tumors 36 surgical treatment consisted of superficial parotidectomy in 31 patients (54.4%); 23 for benign tumors and 8 for malignant tumors. total parotidectomy was required in 6 patients (10.5%); 1 for benign tumor and 5 for malignant tumors. surgical excision of the submandibular gland was performed for 3 patients (5.3%) who had benign tumors. for minor salivary gland tumors 14 patients (24.6%) the surgical treatment consisted of surgical excision; this was carried out for 8 patients with benign tumors and 6 patients with malignant tumors. in 3 patients (5.3%) maxillectomy was performed for malignant tumors involving the hard palate. neck dissection was performed in one patient with high grade mucoepidermoid carcinoma of minor salivary gland origin. apart from postoperative pain and swelling which occurred in all patients, postoperative complications were identified in (17/56, 30.4%) patients. the most common complication was weakness of one or multiple branches of the facial nerve in patients who did not manifest facial nerve weakness preoperatively; this was evident in (12/50, 24%) patients of which 9 patients showed recovery of the neural function within 1 to 4 months postoperatively and 3 were regarded as permanent damage as they demonstrated no recovery after 6 months postoperatively. the other complications included infection and wound dehiscence in 2 patients (3.6%), hematoma formation in 1 patient (1.8%), seroma formation in 1 patient (1.8%) and unsightly hypertrophic scar in 1 patient (1.8%). death in the early postoperative period occurred in one 76 old male patient who had undergone total parotidectomy for adenoid cystic carcinoma making the mortality rate in this series (1.7%). complications were significantly associated with patients’ age, whereas gender and type of tumor whether benign or malignant did not affect the complication rate (table 3). all complications were reported after parotid surgery; total parotidectomy was associated with 100% complication rate whereas superficial parotidectomy was associated with 38.7% (n=12). table 3: factors affecting complication rate (excluding death, n=56) variable complications no complications p value age (mean± sd) 50±11.45 42.5±14.7 0.04 † [s] gender male 9 19 0.77 ‡[ns] female 8 20 type of tumor benign 9 26 0.54 ‡[ns] malignant 7 14 † t-test for 2 independent means ‡ chi square test s: significant. ns: not significant discussion salivary gland tumors are large and diverse group of lesions, characterized by complex clinicopathological features and distinct biological behavior. (1) the annual global incidence reported in the literature is variable ranging from 0.4 to less than 15 cases per 100000 people (1, 7) and geographic and racial factors have been reported to influence the incidence. (8) this study aimed to evaluate the major characteristics of salivary gland tumors in terms of demographic characteristics, histopathological diagnosis, types of surgical treatment, complications and recurrence rates in two centers in baghdad. the mean age of patients in this study (45.4 years) is in line with that reported in other studies. (1, 8, 9) the who in 2005 reported that the average ages of patients with benign and malignant tumors are 46 and 47 years, respectively, (10) in this study, patients with benign tumors were significantly younger than the patients diagnosed with malignant tumors which is in line with many studies. (1, 6, 8) the gender distribution was even in this study which is in keeping with other studies. (11) in general females are more frequently affected by salivary gland tumors but there is some gender variation according to the tumor type, (10) many studies have demonstrated that benign tumors were slightly more common in j bagh college dentistry vol. 31(3), september 2019 salivary gland tumors 37 females, whereas malignancies more often occur in males, (1) this was not demonstrated in this study. with respect to the site distribution this study revealed that the parotid gland was the most common site (64.9%) followed by minor salivary gland (29.8%) which is in line with other studies. (12, 13) the distribution of parotid gland tumors in this study is within the range reported by the who (64-80%), whereas the incidence of minor salivary gland tumors in this study is higher than that reported by the who (9-23%), yet for submandibular gland tumors the incidence reported in this study (5.3%) is lower than that demonstrated by the who (7-11%). (3, 10) sublingual gland tumors were not encountered in this study most likely due to the rarity of these tumors, (6) it is estimated that about 1% of salivary gland tumors affect the sublingual gland. (10, 14) this study showed that benign salivary gland tumors are more common than the malignant tumors, a finding that is well documented in the literature, the incidence of benign and malignant tumors, in this study, is within the range reported by the who being (54-79%) and (21-46%) respectively. (10) however, comparing with the results of other studies from different parts of the world, (1, 6, 8) patients in this study showed higher incidence of malignant tumors, this could be attributed to geographic variation. pleomorphic adenoma was the most common benign tumor and mucoepidermoid carcinoma was the most common malignant tumor followed by adenoid cystic carcinoma with predilection to minor salivary glands which is also demonstrated in other studies. (15, 16) in this study all complications where encountered after treatment of parotid tumors and total parotidectomy was associated with the highest complication rate; this can be attributed to the aggressiveness of the intervention which seems to be a risk factor for development of complications, less aggressive interventions such as extracapsular dissection have been found to reduce the frequency of complications compared to the standard procedures. (17) the most common postoperative complication was postoperative facial nerve dysfunction which is in keeping with other studies. (18, 19) the complication rate was significantly associated with age being more in older patients whereas other variables namely; gender and type of tumor, did not affect the complication rate. despite the small sample size in this study, it can be concluded that benign salivary gland tumors are more common than malignant tumors with no gender predilection and that patients who are diagnosed with malignant tumors are significantly older that patients with benign tumors, parotid gland is the most commonly affected gland with pleomorphic adenoma as the most frequent diagnosis. complications were encountered after parotid surgery with higher incidence after total than partial parotidectomies and that facial nerve dysfuction was the most common complication and the complication rate was significantly associated with the age of patients. references 1. fonseca fp, carvalho mv, almeida op, rangel alca, takizawa mch, bueno ag, vargas pa. clinicopathologic analysis of 493 cases of salivary gland tumors in a southern brazilian population. oral surg oral med oral pathol oral radiol 2012;114:230-239 2. bradley p, o’hara j, diseases of the salivary glands. surgery (oxford) 2012; 30(11): 611-616 doi: 10.1016/j.mpsur.2012.09.006. 3. spiro rh. salivary neoplasms: overview of a 35year experience with 2807 patients. head neck surg 1986; 8:177–84. 4. gao m, hao y, huang mx, ma dq, chen y, luo hy, gao y, cao zq, peng x, yu gy. salivary gland tumours in a northern chinese population: a 50year retrospective study of 7190 cases. int j oral maxillofac surg. 2017; 46: 343– 349. 5. mandel l. salivary gland disorders. med clin n am 2014; 98: 1407–1449 6. wang x-d, meng l-j, hou t-t, huang s-h. tumours of the salivary glands in northeastern china: a retrospective study of 2508 patient. br j oral maxillofac surg. 2015; 53: 132–137. 7. seethala rr. salivary gland tumors current concepts and controversies. surg pathol clin. 2017; 10: 155–176 8. ansari mh. salivary gland tumors in an iranian population: a retrospective study of 130 cases. j oral maxillofac surg 2007; 65: 2187-2194. 9. de oliveira fa, duarte ec, taveira ct, máximo aa, de aquino ec, alencar rde c, vencio. salivary gland tumor: a review of 599 cases in a brazilian population. head neck pathol. 2009; 3:271–5. j bagh college dentistry vol. 31(3), september 2019 salivary gland tumors 38 10. barnes l, eveson jw, reichart p, sidransky d. world health organization classification of tumours: pathology and genetics of head and neck tumours. lyon: iarc press; 2005. 11. nagarkar n., bansal s. and dass a. singhal sk, mohan h: salivary gland tumors – our experience. indian j otolaryngol head neck surg. 2004; 56(1): 31-34 12. lukšić, i., virag, m., manojlović, s., macan, d. (2012). salivary gland tumours: 25 years of experience from a single institution in croatia. j craniomaxillofac surg 2012; 40(3): e75-e81. 13. subhashraj, k. (2008). salivary gland tumors: a single institution experience in india. br j oral maxillofac surg 2008; 46(8): 635-638. 14. tian z, li l, wang l, hu y, li j. salivary gland neoplasms in oral and maxillofacial regions: a 23-year retrospective study of 6982 cases in an eastern chinese population. int j oral maxillofac surg. 2010; 39: 235–242. 15. jones av, craig gt, speight pm, franklin cd. the range and demographics of salivary gland tumours diagnosed in a uk population. oral oncol 2008; 44(4): 407-417. 16. ochicha o, malami s, mohammed a, atanda,a. a histopathologic study of salivary gland tumors in kano, northern nigeria. indian j pathol microbiol2009; 52(4), 473. 17. koch m, zenk j, iro h. long‐term results of morbidity after parotid gland surgery in benign disease. the laryngoscope 2010; 120(4): 724730. 18. rodriguez c p, parvathaneni u, méndez e, martins rg. salivary gland malignancies. hematol oncol clin n am 2015; 29: 1145–1157 19. lombardi d, mcgurk m, vander poorten v, guzzo m, accorona r, rampinelli v, nicolai p. surgical treatment of salivary malignant tumors. oral oncol. 2017;65:102-113. الخالصة موع اورام الراس والرقبة سريريا هذه االورام تكون %من مج3ان اورام الغدداللعابية تعد من االورام المعقدة وتشكل خلفية: والجلد. ان اورام الغدد مجاورة كالعضالتانتشرت النسجة قريبة و الى احجام كبيرةوعندها تكون قدغيرمصاحبةالعراض وتنمو لتصل تؤدي الى نجاح العالج الجراحي لتلك العوامل الرئيسية التي .الصغيرة اللعابية والغدد النكفية اللعابية اكثرشيوعا في الغدد ان الطبيعةالشعاعي والكيميائي ما بعد العملية. وكذلك احتمال الحاجة الى العالج ا االورام:التشخيص الدقيق والفحص ماقبل الجراحة وكذلك االوعية ت الفك االسفلتح بالعصب الوجهي في للغدة النكفية والعصب اللساني وماتحت اللساني في الغدد التشريحية المعقدة المتمثلة جراء الجراحة وكذلك اثناءالجراحة.الدموية والهيكل العظمي والعضلي للمنطقة هذه مجتمعة تتطلب تخطيط وتهيئة دقيق قبل ا جراحةالكبيرة او الصغيرة في قسم مريضا تم ادخالهم ضمن الدراسة وكانو يعانون من اورام في الغدد اللعابية57:المرضى و طرق العمل وايلول 2016الممتدة بين مارس الطب في الفترة الوجه والفكين في مستشفى اليرموك التعليمي ومستشفى الشهيدغازي الحريري في مدينة 2017 اللعابية كان متساوي التوزيع تقريبا في االناث والذكور وكذلك معدل اعمار المرضى ان ظهور االورام في الغدد اظهرت الدراسةالنتائج: كذلك اظهرت الدراسة ان الغالبية العظمى من االورام ظهرت في من اولئك الذين لديهم اورام حميدة. المصابين باورام خبيثة كان اعلى الجراحي الغلب الحاالت ضمن كان االجراء رفع الفص السطحي للغدةالنكفيةم. الصغيرة في سقف الف اللعابية والغدد النكفية اللعابية الغدد لعملية مصاحبة خاصة الجراحة كانت بصورة ان مضاعفات مابعد هذه الدراسة لرفع االورام الحميدة للغدة النكفية وكمااظهرت الدراسة الكامل في حاالت االورام الخبيثة . رفع الغدة النكفية بصورة خاص ت الدراسة ان اغلب المضاعفات كانت مصاحبة لعمليات رفع االورام الخبيثة للغدد اللعابيةاظهراالستنتاج: sama.doc j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 86 the effect of the addition of silanized nano titania fillers on some physical and mechanical properties of heat cured acrylic denture base materials sama a. alwan, b.d.s. (1) shatha s. alameer, b.d.s., m.sc. (2) abstruct background: polymethyl methacrylate (pmma) is the most commonly used material in denture fabrication. the material is far from ideal in fulfilling the mechanical requirement. the purpose of this study was to evaluate the effect of addition of 3% wt of treated (silanized) titanium oxide nano filler on some physical and mechanical properties of heat cured acrylic denture base material. materials and methods: 100 specimens were constructed, 50 specimens were prepared from heat cure pmma without additives (control) and 50 specimens were prepared from heat cure pmma with the addition of tio2 nano fillers. each group was divided into 5 sub groups according to the test performed which was mixed by probe ultrasonication machine. results: a highly significant increase in impact strength and transverse strength was observed with the addition of (tio2) nano particles to (pmma). a significant increase in surface hardness and in surface roughness. the water sorption and solubility were significantly decreased when compared with the control group. conclusions: the addition of tio2 nano particles to heat cure acrylic resin improve the impact strength, transverse strength and surface hardness of heat cure acrylic resin at the same time this addition decrease water sorption and solubility. on the other hand there was an increase in surface roughness with the addition of 3% wt of silanized tio2 nano particles. keywords: nanotio2, tmspm, pmma. (j bagh coll dentistry 2015; 27(1):86-91). introduction pmma is the most commonly used material due to its satisfactory mechanical and physical properties, compatibility with oral tissue, esthetics, ease of repair and low cost (1).the main problem associated with pmma as a denture base material, is poor strength particularly under fatigue failure inside the mouth caused by occlusal biting force and impact failure outside the mouth by dropping the dentures (1). to overcome their physical and mechanical limitations, polymers had been reinforced by adding different metallic oxide (2). recently, much attention have been directed toward the incorporation of inorganic nano particles into pmma to improve its properties (3). the properties of polymer nano composites depend on the type of incorporated nano particles, their size and shape, as well as the concentration and interaction with the polymer matrix (3). tio2 had been a low cost material with chemical stability and non toxicity (4,5). this study was conducted to use inorganic tio2 nano fillers that were added to heat cure pmma and test the effect of this addition on the some mechanical and physical properties of heat cured acrylic denture base material. (1) master student. department of prosthodontics, college of dentistry, university of baghdad. (2)professor, department of prosthodontics, college of dentistry, university of baghdad. materials and methods silanization process according to arkle’s equation, the minimum amount of silane required to create monolayer of silane coating on the fillers as follows: amount of silane (g)= amount of filler (g) × surface area of fillers (m2/g) /minimum coating area of silane coupling agent (m2/g). one hundred milliliter of ethanol aqueous solution (70 vol %) was prepared using 99.8 vol% ethanol and de-ionized water (30 % vol), and adjusted to ph of 4.5 using ph meter through titrating with 99.9% acetic acid. (tmspm) silane coupling agent were added respectively into each ethanol aqueous solution, and stirred. hunderd (100) grams of titania nano particles were added into each tmspm solutions. the mixture was stirred with magnetic stirrer for 20 minutes, then the mixture was sonicated with probe sonication apparatus for 30 minutes, then the solution was left to dry at room temperature for 14 days (6). the (ftir) spectrophotometer was used to determine whether or not functional group of the tmspm have been attached to nano filler by analyzing characteristic vibrations of functional groups (6). specimens grouping one hundred (100) specimens were prepared. the specimens were divided into 2 groups, 50 heat cure pmma specimens without additives (control) and 50 heat cure pmma with silanized j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 87 tio2 nano fillers addition (experimental). each group of specimens was sub divided into 5 groups according to the test selected. preparation of the test specimens atransverse strength test, hardness test, and surface roughness test: a bar shaped specimens with dimensions of 65 mm length, 10 mm width, and 2.5 mm thickness(7) bimpact strength test: a bar shaped specimen with dimension of 80 mm x10 mm x4 mm length, width and thickness respectively (8). cwater sorption and solubility test: circular shaped specimen with diameter 50 mm and thickness 0.5 mm (7) the mould was prepared by using separating medium for coating the plastic pattern. the lower portion of the metal flask was filled with dental stone. the plastic patterns were inserted to approximately one half on their depth, the upper half of the flask was filled with stone. proportioning and mixing of acrylic table 1: proportioning and mixing of acrylic tio2 conc amount of tio2 amount of polymer amount of monomer 0% 0 g 50 22.7 ml 3% 1.5 g 48.5 22.7 ml addition of silanized titania nanofillers: nano tio2 fillers were added to the monomer, the fillers were well dispersed in the monomer by ultra sonication, by using a probe sonication apparatus (120 w, 60 khz) for 3 minutes(9).then the conventional stages of packing, clamping and finishing of the specimens were followed(7). mechanical and physical tests: impact strength test: specimens were construced,stored in distal water at 37 c for 48 hrs in incubator.the impact strength test was performed with impact testing device n431(tinius olsen,usa). impact strength= e/b.d x 103 (8) e: is the impact absorbed energy in joules. b: is the width of the specimens in millimeter. d: is the thickness of the specimens in millimeter. transverse strength test: all the specimens were immersed in distilled water in the incubator at 37°c for (48) hours.test was performed using a universal instron testing machine(tinius olsen,usa). each specimen was positioned on the bending fixture, the load was applied with a cross head speed of 1mm/min by a rod placed centrally between the supports making deflection until fracture occurs. transverse strength= 3pl/2bd2 p: is the peak load l: is the span length(50mm) b: is the sample width d: is the sample thickness (10). surface roughness test the profilometer device (surface roughness tester, th 210, china) was used.3 locations were selected, one in the middle and two at the periphery then the analyzer pass along the specimen surface and the mean of three readings were recorded for each specimen (7). surface hardness test test was performed using durometer hardness tester tr 220, china (shore d hardness).the usual method was to press down firmly and quickly on the indenter and to record the maximum reading. five measurements were recorded on different areas of each specimen and an average of these five readings was recorded (7). water sorption and solubility test: water sorption and solubility measurement was done according to ada specification no12 (10). results ftir result the results of infra red (ir) spectra were obtained by analyzing the characteristic vibrations of functional groups in nano-tio2, modified nano-tio2 help to clarify the interaction of nano-tio2 with tmspm. figure 1: ir of non silanized nano tio2 figure 2: ir of silanized nano tio2 j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 88 sem result: the result of sem showed that + p-p-nano titania fillers were less than 50 nm in size figure 3: nano titania filler under sem mean values, standard deviation, standard error, maximums and minimums of the impact strength test results with t-test parameters are presented in table 2, 3, and figure 4. table 2: descriptive data of impact strength control 3% mean 7.3 8.76 sd 0.402 0.496 se 0.127 0.156 max 7.743 9.349 min 6.486 7.951 table 3: t-test analysis for impact strength t-test pvalue significance 6.819 0.000 hs figure 4: bar chart of impact strength means of studied groups mean values, standard deviation, standard error, maximums and minimums of the transverse strength test results with t-test parameters are presented in table 4, 5, and figure 5. table 4: descriptive data of transverse strength control 3% mean 97.02 117.92 sd 1.392 2.92 se 0.44 0.92 max 99.1 122.3 min 94.7 111.7 table 5: t-test analysis for transverse strength t-test pvalue significance 20.41 0.000 hs figure 5: bar chart of transverse strength means of studied groups mean values, standard deviation, standard error, maximums and minimums of the surface hardness test results with t-test parameters are presented in table 6, 7, and figure 6. table 6: decriptive data of surface hardness control 3% mean 84.37 85.14 sd 0.95 0.61 se 0.30 0.19 max 85.3 86.2 min 82.49 84.5 table7: t-test analysis for surface hardness t-test p-value significance 2.315 0.033 s figure 6: bar chart of surface hardness means of studied groups mean values, standard deviation, standard error, maximums and minimums of the surface roughness test results with t-test parameters are presented in table 8,9, and figure 7. j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 89 table 8: descriptive data of surface roughness control 3% mean 0.28 0.38 sd 0.083 0.084 se 0.026 0.026 max 0.38 0.44 min 0.12 0.23 table 9: t-test analysis for surface roughness t-test pvalue significance 2.857 0.01 s figure 7: bar chart of surface roughness means for studied groups mean values, standard deviation, standard error, maximums and minimums of water sorption test results with t-test parameters are presented in table 10, 11, and figure 8. table 10: descriptive data of water sorption control 3% mean 0.35 0.33 sd 0.013 0.004 se 0.005 0.001 max 0.337 0.346 min 0.338 0331 table 11: t-test analysis for water sorption t-test pvalue significance 3.796 0.001 hs figure 8: bar chart of water sorption means for studied groups mean values, standard deviation, standard error, maximums and minimums of water solubility test results with t-test parameters are presented in table 12, 13, and figure 9. table 12: descrptive data of water solubility control 3% mean 0.017 0.016 sd 0.00104 0.00033 se 0.00125 0.00039 max 0.0192 0.018 min 0.0163 0.014 table 13: t-test analysis for water solubility t-test pvalue significance 3.056 0.007 hs figure 9: bar chart of water solubility means of studied groups disscusion the addition of silanized nano –tio2 to heat cured acrylic was done to evaluate the physical and mechanical properties. titania (tio2) was used because it is biocompatible material (non toxic) and with pleasing color (11,12). the two most useful properties of tio2 are corrosion resistance and the highest strength-to-weight ratio of any metal oxide (13). the addition of silanized nanotio2 increased the value of impact strength, this may be due to high interfacial shear strength between nano fillers and matrix, also the crack propagation can be decreased by good bonding between nano filler and matrix (14), as particle size decrease, the total particle/matrix interfacial surface area available for energy dissipation increase and the critical stress for particles/matrix debonding also increase (15), also the addition of tio2 nano fillers may lead to form efficient network (3dimentional network) of pmma and tio2 nano particles thus lead to reduce the segmental motion (16). there was increasing in the value of transverse strength when 3% of nano tio2 were added to pmma compared with the control group, this may be due to a well dispersion of the <50 nm size of nano particles j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 90 and fill the spaces between chains (17), segmental motion of the macromolecular chains were of the resin (18). on the other hand, the increase of the transverse strength of the denture base with silanized tio2 nano filler might be due to transfer of stresses from more the flexible polymer matrix to the higher modulus (19). it was found that the hardness and surface roughness increased significantly, the increasing in surface hardness might be due to two factors: higher fillers content and use of silane coupling agent (17). the increasing in surface roughness might be due to the presence of nano particles on the surface of each specimen. in this study there was a highly significant decrease in water sorption and solubility of acrylic resin, the decreasing in water sorption might be due to the formation of porosity and micro voids among polymer chains which facilitate fluid trasnsport into and out of polymer. tio2 nano particles used were insoluble in water and could reduce the overall volume of absorbing polymer (20), the use of silane coupling agent in silanization process of nano particles could lead to a reduction in the amount of water that reached to the inner layers of polymer matrix (21), also the decrease in water sorption could be due to the fact that titania nano particles replaced hydrophilic resin, result in a decrease in water uptake. the decreasing in water solubility could be attributed to the fact that titania nano fillers were insoluble in water which would lead to decrease the overall solubility of acrylic resin. in conclusion; the addition of tio2 nano particles to heat cured acrylic resin improve the impact strength, transverse strength and surface hardness of heat cured acrylic resin, at the same time this addition decrease water sorption and solubility. on the other hand there was an increase in surface roughness with the addition of 3% silanized nano tio2. references 1. alla rk, sajjan s, alluri vr, ginjupalli k, upadhya n. influence of fiber reinforcement on the properties of denture base resins. j biomat and nanotechnol 2013; 4: 91-7. 2. mc cabe jf, walls awg. applied dental materials. 8th ed. oxford: blackwell scientific publication; 1998). p.63. 3. jordan j, jacob kl, tannenbaum r, shart ma, jasiuk i. experimental trends in polymer nano composites-a review. mater sci eng 2005; 393(1): 1-11. 4. hoffman mr, martin st, choi w, bahnemann dw. environmental application of semiconductor photocatalysis. chem rev 1995; 95(1): 69-96. 5. fujishima a, rao tn, tryk da. titanium dioxide photocatalysis. j photo chem and photo bio c 2000; 1: 1-12. 6. pisaisit c, hidekazu t, norihiro n, mansuang a. effect of different amounts of 3methacryloxypropyltrimethoxysilane on the flexural properties and wear resistance of alumina reinforced pmma. dent mater j 2012; 31(4): 623–8. 7. american dental association specification no. 12 for denture base polymer guide to dental materials and devices. 7th ed. chicago illinois, 1999. 8. iso 179-1:2000: plastics -determination of charpy impact properties -part 1: non-instrumented impact test. 9. mohammed a, solhil, nodehi a, mirabedini sa, kasraei s, akbari k, babanzadeh s.: "pmma-grafted nano clay as novel filler for dental adhesives. dent mater 2009; 25: 339-47 10. american dental association, specification no.12, (2000). chicago il: ansi/ada. 11. emsley j. titanium nature bulding blocks an a-z guide to the elements, oxford, england, uk, oxford university press isbn 0-1985040-7, 2001, p. 452. 12. gao l, sun j, liu yq. the dispersion and surface modification of nano particles. beijing: puplishing house of chemical industry; 2003. 13. donachie j, matthew jr. titanium a technical guide. metal park, asm international; 2nd ed. 2000. 14. sun l, ronald fg, suhr j, grodanine jf. energy absorption capability of nanocomposites; a review. composites science and technology 2009; 69: 2392409. 15. chen j, huang z, zhu j. size effect of particles on the damage dissipation in nanocomposites. compos sci technol 2007; 67(14): 2990-6. 16. hu y, zhou s, wu l. surface mechanical properties of transparent pmma/ zirconia nanocomposites prepared by in situ bulk polymerization. polymer 2009; 50: 360916. 17. yang xia, feimin z, xie h, gu. nano particlesreinforced resin based dental composites. j. dentistry 2008; 36: 450-5. 18. katsikis n, franz z, anne h, helmut m, andri v. thermal stability of pmma/ silica nanoand micro composites as investigated by dynamic-mechanical experiments. polym degra and stability, 2007; 22: 1966-76. 19. anusavice kj. philips science of dental material. 11th ed. middle east and african edition 2008. p: 143166,721-756. 20. ferracane jl. hygroscopic and hydrolytic effects in dental polymer networks. dent mater 2006; 22: 211– 22. 21. vallittu pk. comparison of two different silane compounds used for improving adhesion between fibers and acrylic denture base material. j oral rehabil 1993; 20: 533–9. الخالصة كان الغرض من ھذه . المواد بعیدة عن المثالیة في الوفاء بالمتطلبات المیكانیكیة. میثاكریالت ھو المادة االكثر استخدامًا في تصنیع طقم االسنان :بیان المشكلة .ت اوكسیدالتیتانیوم النانویة المعالجة سطحیًا لطقم االسنان االكریللي الحراري الراتنجيبالوزن من حبیبا% 3الدراسة ھو لتقییم اضافة عینة االخرى محضرة من االكریلك الحراري مع اضافة حبیبات 50و ) القیاسي(منھا اعدت من االكریلك دون اضافات 50عینة، 100تم تصنیع :المواد والطرق .مجموعات فرعیة وفقًا لالختبارات التي اجریت وقد تم الخلط من قبل المسبار الة صوتیة فائقة 5یم كل مجموعة الى اوكسیدالتیتانیوم النانویة تم تقس j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 91 جي و زیادة قلیلة في لوحظ وجود زیادة كبیرة للغایة في قوة الصدمة والقوة العرضیة عند اضافة حبیبات اوكسید التیتانیوم النانویة لالكریلك الحراري الراتن :النتائج .صالبة السطح وخشونتھ مع انخفاض بشكل ملحوظ في امتصاص وذوبانیة الماء مقارنة مع المجموعة القیاسیة من تحسن من قوة الصدمةوالقوةالعرضیة وصلبة السطح وكذلك تقللل افة حبیبات اوكسید التیتانیوم النانویة المعالجةسطحیالمادة االكریلك الحراريان اض :االستنتاج .امتصاص وذوبانیة الماء من ناحیة اخرى ھناك زیادة في خشونة السطح j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 7 effect of polyamide (nylon 6) micro-particles incorporation into rtv maxillofacial silicone elastomer on tear and tensile strength abdalbasit a. fatihallah, b.d.s, m.sc., ph.d.(1) manar e. alsamaraay, b.d.s (2,3) abstract background: the longevity of any prosthesis depends on the materials from which it was fabricated, that is why, defects in the material properties may reduce the service life of prosthesis and necessitate its replacement. the aim of this study was to evaluate the effect of adding different concentrations of polyamide-6 (nylon-6) on the tear and tensile strength of a-2186 rtv silicone elastomer. materials and methods: 80 samples were fabricated by the addition of 0%, 1%, 3% and 5% by weight pa-6 micro-particles powder to a2186 platinum rtv silicone elastomer. the study samples were divided into four (4) groups, each group containing 20 samples. one control group was prepared without pa-6 micro particles and three experimental groups were prepared with different percentage of pa-6 micro particles (1%, 3%, and 5%) by weight. each group was further subdivided into 2 groups according to the conducted tests, i.e. tear and tensile strength tests (n=10). the data were analyzed with a descriptive statistical analysis, one-way anova, post-hoc lsd test. results: the mean value of tear and tensile strength of 1% pa-6 reinforcement group increased significantly when compared to control group on the contrast to the same values of 3% and 5% pa-6 reinforcement groups which were decreased significantly. conclusion: the 1% pa-6 reinforcement improved tear as well as tensile strength among all other percentages (0%, 3% and 5%). keywords: polyamide, room temperature, silicone elastomer. (j bagh coll dentistry 2017; 29(4):7-12) introduction patients with facial defects are preferred to be treated through surgical intervention whenever favorable circumstances are present. however; prosthetic restoration for patients suffering from facial deformities may also considered satisfactory; this type of treatment works as a psychological therapy allowing the individuals to integrate again into society after becoming embarrassed, constrained and diminished physically and psychologically. it helps people to reestablish their self-esteem and confidence (1,2) . in general, the goal of prosthodontic rehabilitation is not constrained by restoring function and esthetic; hence, different types of maxillofacial materials have become noticed (3,4). silicone elastomer m a y be considered as the material of choice when fabricating facial prostheses due to its biocompatibility, low chemical reactivity, ease of manipulation, and optical transparency (5). however, its mechanical properties do not fulfill the ideal requirements, resulting in a reduction in the clinical longevity of the prosthesis. that is why; reinforcement of this material may become mandatory to overcome its deficiencies (6). gunay et al. in (2008)(7) reported improvement in the tear strength and other mechanical 1) assistant professor, department of prosthodontics, college of dentistry, university of baghdad 2) m.sc. student, department of prosthodontics, college of dentistry, university of baghdad. 3) department of prosthodontics, college of dentistry, al-mustansiriyah university. properties of a-2186 room temperature vulcanized (rtv) silicone elastomer after being incorporated with tulle (nylon). additionally, various researchers mentioned the use of different types of additives which incorporated within the silicone matrix and resulted in improvement in the mechanical and physical properties of the silicone base material (8,9,10). the aim of the present study was to evaluate the effect of adding different weight percentage (1%, 3%, 5%) of polyamide-6 (nylon-6) on the tear and tensile strength, of a-2186 rtv silicone elastomer. materials and methods this study investigated the tear and tensile strength of a-2186 platinum rtv silicone elastomer (factor ii inc., lakeside, az, usa) before and after the addition of polyamide-6 (nylon-6) micro-particles powder (average particle size 15-20 micron) (goodfellow, cambridge limited, england). a specialized cutting of 4±0.05 mm and 2±0.05 mm thickness acrylic sheets (pt. margacipta wirasentosa, indonesia) is performed by using a laser engraving cutting machine (jl-1612, jinan link manufacture & trading co., ltd., china) to prepare the mold parts. the depth of the mold cavity, 2±0.05 mm thickness sheets, corresponds to the thickness of the specimens to be fabricated for each conducted test while the 4±0.05 mm thickness sheets were used to make the bottom and cover parts (10). a-2186 is a platinum rtv silicone elastomer consisting of 2 parts; part a https://linkcnc.en.alibaba.com/?spm=a2700.8304367.0.0.wsupp2 https://linkcnc.en.alibaba.com/?spm=a2700.8304367.0.0.wsupp2 j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 8 representing the silicone base while part b representing the cross linker. the pa-6 fillers were first weighed by electronic digital balance followed by the addition of accurate weight of silicone (part a) to prevent dispersion of the filler. the modified silicone was mixed by a vacuum mixer (multivac 3, degussa, germany) for 10 minutes; the vacuum was turned off for the first three minutes to avoid suction of the filler and then turned on for the rest of the 7 minutes at 360 rpm speed and a vacuum value of 10 bar. the silicone cross linker (part b) was added to the silicone base (0% pa-6) or the modified silicone (part a and pa-6) and mixed again in the vacuum mixer for 5 minutes to get a homogenous and free bubble mixture (11). the mold was brushed with separating medium and left to dry then the silicone mixture was poured and the mold was closed with the aid of screws and g-clamps (10). according to manufacturer’s instruction, the silicone should be set aside for 24 hours at 23± 2°c and a relative humidity of 50%±10 % for complete setting (figure 1). figure 1: silicone was poured inside the mold after polymerization, the silicone sheet (15×15 cm) (12) was separated from the mold cavity and was cut (figure 2) by suitable cutting dies with the help of a custom-made specimen cutting press. the press consists of hydraulic jack of (3) tons capacity (lezaco, syria) attached to metal plates; this type of cutting ensures smooth cut surfaces. figure (2): specimen's preparation through cutting of the silicone sheet. a, tear specimens; b, tensile specimens all specimens were visually inspected for surface irregularities, bubbles and internal defects (13) then, they were stored inside a vaccine storage box (polar bag, china) for, at least, 16 hours of favorable conditions before testing (2,14,15). all test specimens were tested with a computerized universal testing machine (wdw20, laryee technology co. ltd., china) at 500 mm/min cross-head speed (9).. according to iso 37 (17), forty specimens of type 2 dumb-bell shape were fabricated for tensile strength , 10 specimens were used as control group and the other 30 were silicone specimens after the addition of different concentrations of pa-6 fillers, (n=10). specimens were mounted in a computerized universal testing machine 25±0.5 mm apart (9). the maximum load was calculated by the machine software then the tensile strength was calculated according to the following equation: tensile strength=f/a where: f: the maximum force recorded at break (n). a:the original cross-sectional area of the specimen (mm2). forty specimens of type c which is an unnicked specimen with a 90° angle on one side and with tab end specimens, were fabricated according to astm d624(18) for tear strength test, 10 specimens were used as control group and the other 30 were silicone specimens after the addition of different concentrations of pa-6 fillers, (n=10). specimens were mounted in a computerized universal testing machine with a 30±0.5 mm distance apart (19). the maximum load was calculated by the machine software then the tear strength according to the following equation: tear strength=f/d where: f: the maximum force required for specimen to break (kn). d: the median thickness of each specimen (m). furthermore, sem analysis was performed on 4 samples. one sample represents the silicone material before the addition of pa-6 fillers and the other 3 were after the addition of 1%, 3% and 5% of pa-6 fillers respectively. results 3.1. scanning electron microscope sem results of a-2186 platinum rtv silicone elastomer before and after the addition of 1%, 3% and 5% by weight pa-6 micro-particles powder are shown in (figure 3). a b a b j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 9 figure (3): sem of a-2186 silicone elastomer. a, before the addition of pa-6 fillers; b, after the addition of 1% pa-6 fillers; c: after the addition of 3% pa-6 fillers and d: after the addition of 5% pa-6 fillers sem images demonstrated that when the concentration was increased to 3%, the pa-6 micro particles began to agglomerated; this agglomeration was further increased when the fillers loading increased to 5% as well. 3.2. tear and tensile strength test. figure 4 represents the mean values of tear and tensile strength of a-2186 silicone elastomer before and after the addition of 1%, 3% and 5% pa-6 fillers. highest mean value of tear and tensile strength were found in (1% by weight) pa-6 filler group while the lowest mean value of the both tests were found in (5% by weight) pa6 filler group. figure (4): graphical representation of mean values by bar chart descriptive statistics, one-way analysis of variance (anova), post-hoc lsd analysis, pearson correlation, coefficient of determination and % of variation of the tear and tensile strength values are presented in tables 14. the results of tear strength test indicated highly significant difference (p≤0.01) between all tested groups (table 1). the tear strength mean value of the group formed by the addition of 1% pa-6 micro particles fillers to the silicone elastomer was high significantly (𝑃 ≤ 0.01) greater than that of all other study groups of (0%, 3% and 5%) pa-6 micro fillers (table 2). the results of tensile strength test indicated highly significant difference (p≤0.01) between all tested groups except for the group formed by the addition of 3% pa-6 micro fillers when compared to the control group, where a non significant difference (p≥0.05) was reported (table 3,4). the tensile strength mean value of the group formed by the addition of 1% pa-6 micro particles fillers to the silicone elastomer was high significantly (p≤ 0.01) greater than that of all other study groups of (0%, 3% and 5%) pa-6 micro fillers (table 4). c d table (1): descriptive statistics and one -way analysis of variance (anova) for tear strength test % of pa-6 fillers n mean sd se min. max. anova f-test p. value sig. 0% 10 16.15 0.64 0.20 15.2 17 195.58 0.000 hs 1% 10 20.98 1.21 0.38 19.2 22.79 3% 10 14.54 0.82 0.26 13.72 15.88 5% 10 11.83 0.67 0.21 10.8 12.8 j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 10 discussion tear and tensile properties are the most important properties regarding facial prosthesis (20). in view of the fact, testing the mechanical properties is an important step towards the modification of the current material or acceptance of a new one (9). the aim of this study was to investigate the tear and tensile properties of the tested maxillofacial silicone material which can only be achieved by the addition of correct filler concentration which becomes somehow mandatory because the unfilled cross-linked polydimethylsiloxane has very low mechanical properties (5,21). after the addition of 1% by weight pa-6 micro fillers, the mean value of the tear strength test demonstrated highly significant increase in comparison to the control group by. this may be due to the nature of the fillers; the amide (-conh-) groups within the filler structure are highly polar, so, pa-6 forms multiple hydrogen bonds among adjacent strands (22), this property may result in forming a 3-d network of fillers within the polymer matrix that lead to a change in the overall density and increase overall tearing resistance of the polymer (23). when the filler loading increased to 3%, the mean value of the tear strength test decreased in a highly significant manner in comparison to the control group. moreover, the mean value of the tear strength test also decreased in a highly significant manner in comparison to the control group when the fillers percentage increased to 5%. these changes in the mechanical properties (reduction) can be explained by the sem images (figure 3), where the pa-6 micro particles fillers had agglomerated to a different extent when the fillers loading increased. as depicted in the statistical analysis, the tensile strength test mean value was increased in a high significant manner after the addition of 1% by weight pa-6 micro fillers, in comparison to the control group. this may be due to increasing in table (2): post-hoc lsd, pearson correlation (r), coefficient of determination (r2) and % of variation for tear strength test compared groups lsd mean difference (i-j) p. value sig. r r2 % of variation p. value sig. 0% 1% -4.83 0.000 hs 0.57 0.32 32.49 0.07 ns 3% 1.60 0.000 hs -0.46 0.21 21.16 0.90 ns 5% 4.31 0.000 hs -0.45 0.20 20.25 0.18 ns 1% 3% 6.44 0.000 hs 0.09 0.008 0.81 0.80 ns 5% 9.14 0.000 hs -0.13 0.016 1.69 0.70 ns 3% 5% 2.70 0.000 hs -0.52 0.014 1.44 0.12 ns table (3): descriptive statistics and one -way analysis of variance (anova) for tensile strength test % of pa6 fillers n mean sd se min. max. anova f-test p. value sig. 0% 10 4.40 0.56 0.17 3.44 5.20 29.69 0.000 hs 1% 10 5.74 0.67 0.21 4.70 6.60 3% 10 4.20 0.55 0.17 3.20 4.85 5% 10 3.46 0.38 0.12 2.80 4.00 table (4): post-hoc lsd, pearson correlation (r), coefficient of determination (r2) and % of variation for tensile strength test compared groups lsd mean difference (i-j) p. value sig. r r2 % of variation p. value sig. 0% 1% -1.33 0.000 hs 0.68 0.46 46.24 0.02 s 3% 0.18 0.45 ns -0.34 0.11 11.56 0.32 ns 5% 0.94 0.000 hs 0.29 0.08 8.41 0.40 ns 1% 3% 1.52 0.000 hs -0.39 0.15 15.21 0.26 ns 5% 2.28 0.000 hs 0.39 0.15 15.21 0.26 ns 3% 5% 0.76 0.004 hs -0.30 0.09 9.00 0.39 ns https://en.wikipedia.org/wiki/chemical_polarity https://en.wikipedia.org/wiki/hydrogen_bond https://en.wikipedia.org/wiki/hydrogen_bond j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 11 the overall cross-linking density of the polymer, after the addition of the filler, by forming multifunctional cross-links making the polymer stronger and stiffer; in other words, prevent the polydimethylsiloxane chains from breaking under tensional forces (24). additionally, during testing, the input energy that is responsible of breaking the polymer network may be dissipated into heat by filler incorporation, hence; higher amounts of energy needed to be available to cause the deformation (25). on the contrast to that, a nonsignificant reduction in the tensile strength means value in comparison to the control group was reported. again, when the filler loading increased to 5%, the mean value of the tensile strength test decreased in a highly significant manner in comparison to the control group. this reduction is explained by the sem images (figure 3), where the pa-6 micro particles fillers had agglomerated to a different extent when the fillers loading increased resulting in reducing the mechanical properties of a-2186silicone elastomer. conclusions the following conclusions were reached after taking into consideration the limitations of this study 1. the results of this study revealed significant improvement in the tear strength and tensile strength of a-2186 rtv silicone elastomer after the addition of 1% concentration of pa-6 micro particles powder. 2. as the pa-6 micro particles loading increased to 3% and 5%, impairment in the mechanical properties were noticed. references 1. goiato mc, pesqueira aa, da silva cr, gennari fh, dos santos dm. patient satisfaction with maxillofacial prosthesis. literature review. j plast reconstr aesth surgy 2009; 62(2):175-180. 2. haddad mf, goiato mc, dos santos dm, moreno a, d’almeida nf, pesqueira aa. color stability of maxillofacial silicone with nanoparticle pigment and opacifier submitted to disinfection and artificial aging. j biomed opt 2011; 16(9):095004-095006. 3. marafon pg, mattos bs, sabóia ac, noritomi py. dimensional accuracy of computer-aided design/ computer-assisted manufactured orbital prostheses. int j prosthodont 2 0 1 0 ; 23(3): 271–276. 4. scolozzi p, jaques b. treatment of midfacial defects using prostheses supported by iti dental implants. plast reconstr sur 2004; 114(6): 13951404. 5. hatamleh mm, watts dc. effects of accelerated artificial daylight aging on bending strength and bonding of glass fibers in fiber-embedded maxillofacial silicone prostheses. j prosthodont 2010; 19(5): 357–363. 6. udagama a, drane jb. use of medical-grade methyl triacetoxy silane crosslinked silicone for facial prostheses. j prosthet dent 1982; 48(1): 8688. 7. gunay y, kurtoglu c, atay a, karayazgan b, gurbuz cc. effect of tulle on the mechanical properties of a maxillofacial silicone elastomer. dent mater 2008; 27(6): 775-779. 8. han y, kiat-amnuay s, powers jm, zhao y. effect of nano-oxide concentration on the mechanical properties of a maxillofacial silicone elastomer. j prosthet dent 2008; 100(6): 465-473. 9. zayed sm, alshimy am, fahmy ae. effect of surface treated silicon dioxide nanoparticles on some mechanical properties of maxillofacial silicone elastomer. int j biomater 2014; 2014: 750398-750405. 10. atta allah j, muddhaffer m. influence of artificial weathering on some properties of nano silicon dioxide incorporated into maxillofacial silicone. ijsr 2017; 6(5): pp. 423-428. 11. tukmachi m, moudhaffer m. effect of nano silicon dioxide addition on some properties of heat vulcanized maxillofacial silicone elastomer. jpbs 2017; 12(3-4): 37-43. 12. rai sy, guttal ss. effect of intrinsic pigmentation on the tear strength and water sorption of two commercially available silicone elastomers. j indian prosthodont soc 2013; 13(1): 30-35. 13. iso/tr 27628. workplace atmospheres ultrafine, nanoparticle and nano-structured aerosols inhalation exposure characterization and assessment. 2007. 14. dos santos dm, goiato mc, moreno a, pesqueira aa, de carvalho dekon sf, guiotti a m. effect of addition of pigments and opacifier on the hardness, absorption, solubility and surface degradation of facial silicone after artificial ageing. polym degrad stab 2012; 97(8): 12491253. 15. abdullah ha. evaluation of some mechanical properties of a new silicone material for maxillofacial prostheses after addition of intrinsic pigment. m.sc. thesis, university of baghdad. 2016; 53-58 16. astm g154-06, standard practice for operating fluorescent ultraviolet (uv) lamp apparatus for exposure of nonmetallic materials. astm international, west conshohocken, pa, usa. 2006. 17. iso 37. rubber, vulcanized or thermoplastic — determination of tensile stress-strain properties.2011. 18. astm d624-00. standard test method for tear strength of conventional vulcanized rubber and thermoplastic elastomers. astm international, west conshohocken, pa, usa. 2012. 19. al-harbi fa, ayad nm, saber ma, arrejaie as, morgano sm. mechanical behavior and color change of facial prosthetic elastomers after outdoor weathering in a hot and humid climate. j prosthet dent 2015; 113(2): 146-151. 20. aziz t, waters m, jagger r. analysis of the properties of silicone rubber maxillofacial prosthetic materials. j dent 2003; 31(1): 67-74. j bagh college dentistry vol. 29(4), december 2017 effect of polyamide among restorative dentistry 12 21. colas a, curtis j. silicone biomaterials: history and chemistry & medical applications of silicones. 2nd ed. elsevier, incorporated; 2005.699, 705. 22. varatharajan s, krishnaraj r, sakthivel m, kanthavel k, palani r. design and analysis of single disc machine top and bottom cover. ijser 2011; 2(8): 2. 23. zhu aj, sternstein s. nonlinear viscoelasticity of nanofilled polymers: interfaces, chain statistics and properties recovery kinetics. compos sci technol 2003; 63(8): 1113-1126. 24. andreopoulos a, evangelatou m, evaluation of various reinforcements for maxillofacial silicone elastomers. j biomater app 1994; 8(4): 344-360. 25. rajkumar k, ranjan p, thavamani p, jeyanthi p, jeyanthi p. dispersion studies of nanosilica in nbr based polymer nanocomposite. rasayan j chem 2013;6(2): 122-133. الخالصة ان استمرار عمل اي تعويضات اصطناعية يعتمد على المادة المصنوعة منها تلك التعويضات لذلك فان اي خلل في نوع المادة سيؤدي الى خلل في استمرارية وديمومة تلك التعويضات ما يستوجب حينها استبدالها. ان الهدف من هذه الدراسه هو بيان تأثير . تم تصنيع a-2186( على قوتي الشد والتمزق لسيليكون الوجه والفكين نوع 6-)نايلون 6-ادة البولي امايداضافة تراكيز مختلفه من م المايكروي الى سيليكون الوجه والفكين المطاطي المفلكن 6-وزنا من مسحوق البولي امايد %5و %3,%1,%8عينة بأضافة 08 عينة. تم تحضير المجموعة 08الى اربع مجاميع, كل مجموعة تحوي . قسمت عينة الدراسة a-2186بدرجة حرارة الغرفة نوع المايكروي, كما تم تحضير المجاميع الثالث االخرى بأضافة تراكيز مختلفه من مادة 6-الضابطه بدون اضافة مسحوق البولي امايد فحص, حيث ان كل مجموعة وزنا( ومن ثم قسمت كل مجموعة الى مجموعتين طبقا لنوع ال %5و %3,%1,) 6-البولي امايد ومجاميع ةقد حسن من خاصيتي الشد والتمزق مقارنة بالمجموعة الضابطه %1عينات. ان تدعيم السيليكون بنسبة 18تحوي الدراسة االخرى. j bagh college dentistry vol. 32(4), december 2020 effect of aging media 5 effect of ageing media on shear bond strength of metal orthodontic brackets bonded with different adhesive systems (a comparative in-vitro study) ahmed dhiaa hatf (1), mustafa m al-khatieeb(2) https://doi.org/10.26477/jbcd.v32i4.2912 abstract background: the aim of this study was to evaluate the shear bond strength (sbs) and adhesive remnant index (ari) of different orthodontic adhesive systems after exposure to aging media (water storage and acid challenge). materials and methods: eighty human upper premolar teeth were extracted for orthodontic purposes and randomly divided into two groups (40 teeth each): the first group in which the bonded teeth were stored in distilled water for 30 days at 37°c, and the second group in which the bonded teeth were subjected to acid challenge. each group was further subdivided into four subgroups (10 teeth each) according to the type of adhesive system that would be bonded to metal brackets: either non-fluoride releasing adhesive (nfra), fluoride releasing adhesive (fra), fluoride releasing bond with self-etching primer (frbsp), or powder and liquid orthodontic fluoride releasing adhesive (plfra). after 30 days of water storage and acid challenge ageing procedures, the sbs was determined using instron testing machine with a crosshead speed of 1 mm/min. the ari was assessed using a stereomicroscope with 10 x magnification. result: the sbs testing revealed significant differences (p< 0.05) among the four tested adhesive systems in water storage and acid challenge groups using anova f-test. in both groups, the nfra subgroup exhibited the highest mean sbs value, followed by frasp, then fra subgroups, while the plfra subgroup had the lowest value of mean sbs. the independent t-test showed non-significant differences in mean sbs values between water storage and acid challenge groups. in respect to the ari analysis, the chi-square test showed significant differences among the tested adhesive systems. conclusion: the shear bond strength of the fluoride releasing adhesive system was less than that of the non-fluoride releasing adhesive system, but still above the clinically acceptable range. keywords: fluoride releasing adhesive, acid challenge, water storage, shear bond strength.(received: 20/8/2020; accepted: 1/11/2020) introduction fixed orthodontic appliances are still associated with a high risk of white spot lesions (wsls) formation, even with the improvements in materials and treatment mechanics. the prevalence of the wsls during orthodontic therapy expressed to a range from 13% to 75%.(1) the maintenance of oral hygiene is impeded by components of fixed orthodontic appliances, which encourage the plaque accumulation around the bracket base. these lesions can occur through a short duration of about 4 weeks, which is usually within the intervals of orthodontic treatment appointments.(2) the prevention of the wsls must be the first goal of an orthodontist. accordingly, the most essential way for averting wsl development is the patient education and motivation. the other means have been utilized for reducing the extent of wsls are dentifrice, mouthwash, gels, and varnishes; all are formulated with fluoride.(3) (1) master student, department of orthodontics, college of dentistry, university of baghdad (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad corresponding author: ahmed.almusawey12@gmail.com in restorative dentistry and orthodontics, the fluoridereleasing bonding system, clearfil liner bond f (kuraray medical inc, okayama, japan) has been advanced. it contained a specially treated sodium fluoride (naf), which was effective in reducing the demineralization while maintaining the bonding strength.(4) the light bond paste and sealant have been developed as polyacid modified composite resins, with a patented monomer of fluoride-releasing property and it has been shown that the bond strength was maintained while fluoride would be regularly released into the mouth.(5) resin modified glass ionomer cements (rmgic) have been combined with the preferable properties of composite resin including the shear bond strength (sbs) and fluoride releasing feature of glass ionomer cement. several rmgics have been evaluated for sbs, one of them was fuji ortho lc (gc company, tokyo, japan) which had a bond strength of a comparable value to composite resins.(6) oncag et al (7) evaluated the effect of acidic soft drinks on the sbs of orthodontic brackets and found that the bracket retention was adversely affected. under the sem, they observed the formation of erosive defects on the enamel surface around the adhesive. so far to our knowledge, the fluoride-releasing adhesives have not been tested for the sbs under the effect of acidic attack. accordingly, the objective of the current study was to evaluate the shear bond strength and the https://doi.org/10.26477/jbcd.v32i4.2912 mailto:ahmed.almusawey12@gmail.com j bagh college dentistry vol. 32(4), december 2020 effect of aging media 6 adhesive remnant index of the different orthodontic adhesive systems after exposure to aging media (water storage and acid challenge) for 30 days. materials and methods after inspection of 138 human upper first premolars extracted for orthodontic purposes, only 80 teeth were involved that had an intact buccal surface and free from caries, restorations, cracks, fluorosis and not subjected to any chemical treatment. they were stored in 1 % chloramine-t solution for one week and subsequently kept in deionized water until conducting the bonding procedures.(8) the teeth were divided into two groups (40 teeth each): the first group in which the bonded teeth would be saved in distilled water for 30 days at 37°c and the second group in which the bonded teeth would be subjected to acid challenge. each group was subdivided into four subgroups equivalent to the bonding procedures (10 teeth each) and mounted in auto-polymerized acrylic blocks before bonding. the acrylic blocks were coded to facilitate the randomization procedure. brackets eighty upper first premolar stainless-steel brackets of discovery® smart type (dentaurum company, ispringen, germany) were used in this study. the prescription of upper premolar bracket was mbt system with slot size 0.022×0.030 of an inch and the bracket’s bonding surface area is 10.56 mm2. bonding procedures at room temperature, the bonding procedure was performed by one of the four adhesive systems according to the manufacture instructions as followed: 1. non-fluoride releasing adhesive: the enamel surfaces were etched with 37% phosphoric acid etching gel (perfectetch-e, perfection plus, uk) for 30 seconds, then washed for 10 seconds and air-dried gently. a thin film of transbond xt primer was applied to the etched enamel surfaces, then polymerized by a led light curing unit (o-light, woodpecker, china) for 10 seconds. 2. fluoride releasing adhesive: the teeth were bonded with light bond paste and sealant (reliance orthodontic products, itasca, illinois, usa). the liquid etchant (37% phosphoric acid) was applied to the buccal tooth surfaces for 30 seconds, then washed for 30 seconds and air-dried gently. the fluoride releasing sealant resin was painted with a disposable brush in a thin uniform coating, followed by mild airdrying, and then cured for 30 seconds.(5) 3. fluoride releasing bond with self-etching primer: the teeth were bonded with clearfil liner bond f (kuraray noritake dental inc., okayama, japan) and transbond xt paste. the self-etching primer was applied for 20 seconds, then dried with a mild air flow. the clearfil liner bond f which had fluoride releasing property, was applied, gently air flowed to create a uniform bond film, and light cured for 10 seconds.(9) 4. powder and liquid orthodontic fluoride releasing adhesive: the teeth were bonded with fuji ortho lc (gc company, tokyo, japan). the etching gel (37% phosphoric acid) was applied for 30 seconds, then washed for 10 seconds. the bonding area was not completely desiccated through the bonding procedure. the cement was prepared by one scoop of powder and two drops of liquid on a mixing pad using a plastic spatula to achieve a glossy consistency.(10) in the four bonding procedures, the bracket base was coated with an adhesive paste or cement, and placed at the center of the buccal tooth surface. a load (200 gm) was placed on each bracket using a surveyor for 10 seconds to achieve uniform adhesive thickness.(11) any excess of adhesive was removed by dental explorer before the curing. the led light curing unit with curing intensity 1200 mw/cm² was applied for 40 seconds (10 seconds from each side of bracket).(5) once the bonding procedures were completed, the bonded teeth of first group were stored in the incubator in distilled water inside sealed containers at 37°c for 30 days with daily refreshment, in order to avoid the cumulative effects.(12,13) while the bonded teeth in the second group stored in deionized water for 24 hours at 37°c prior to the acidic challenge experiment. the acidic solution (ph=2.5) of 500 ml was prepared by gradual addition of 1.5 ml of hcl [1m] in distilled water. the acidic challenge was performed by immersing the samples in the acidic solution through a protocol of three session per day, 5 min each, with equal intervening periods (2 hour) for 30 days. the samples were stored in distilled water (ph=6) at 37°c for the remaining time in order to mimic the wet oral environment. after each session, each storage medium was periodically renewed, and before and after each session, the samples were rinsed with water and air dried.(13) shear bond strength test the tinius-olsen universal testing machine was used to carry out the shear bond strength test after water storage and acid challenge ageing procedures for 30 days using a 5 kn load cell with a crosshead speed of 1 mm/min.(14) at the enamel-bracket interface, the load was applied vertically in the occluso-gingival direction from knife-edge rod (which was fixed inside the upper j bagh college dentistry vol. 32(4), december 2020 effect of aging media 7 arm of the universal testing machine) until adhesive failure occurred. the debonding force was recorded in units of newton and then divided by the surface area of the bracket base (10.56 mm2) to get the readings in megapascal (mpa).(15) estimation of adhesive remnant index the stereomicroscope (hamilton, italy) with 10 x magnification was utilized to examine the enamel surface of each tooth and the debonded bracket, in order to assess the predominant site of bond failure. the site of bond failure was scored according to artun and bergland(16) as followed: 0 = no adhesive remained on the tooth surface. i = less than 50% adhesive remained on the tooth surface. ii = more than 50% adhesive remained on the tooth surface. iii = all the adhesive is remained on the tooth surface. statistical analysis the collected data were analyzed using spss (version 25.0, spss inc. illinois, usa). the statistical analyses involved one-way analysis of variance (anova), post-hoc tukey’s hsd test, chi-square test, and independent sample t-test. the level of significance p< 0.05 was considered for statistical evaluations. results table 1 shows the mean, standard deviation (s.d.), standard error (s.e.) minimum (min.), and maximum (max.) values of shear bond strength (sbs) in both ageing groups. in water storage group, the highest mean value of sbs was in nfra group (26.524 ± 3.767), followed by that of frbsp group (24.244 ± 4.553), then fra group (21.408 ± 3.424), and lastly the plfra group, which had the lowest mean of sbs (18.346 ± 4.109), while in acid challenge group, the highest mean value of sbs was in nfra group (25.880 ± 3.938), followed by that of frbsp group (23.856 ± 4.030), then fra group (20.900 ± 3.403), and lastly the plfra group, which had the lowest mean of sbs (16.779 ± 3.653). table 2 shows the comparison of mean difference of sbs values among all tested adhesive systems in both ageing groups. the one-way analysis of variance (anova) revealed that there were significant differences between all adhesive systems in both ageing groups. in both groups, the post-hoc tukey’s hsd test revealed similar results where there was significant differences between nfra and plfra groups, between nfra and fra groups, while non-significant differences between nfra and frbsp, fra and frbsp, and fra and plfra groups; excepting that the difference was significant between frbsp and plfra in water storage and highly significant in acid challenge group. table 3 presents the frequencies and percentages of ari scores for all tested adhesive systems. in water storage group, the highest frequency of ari score 0 was found in fra group, while the highest frequency of score i was found in fra and frbsp groups, the highest frequency of score ii was found in nfra group, and the highest frequency of score iii was found in plfra group. in acid challenge group, the highest frequency of ari score 0 and i were found in fra group, while the highest frequency of score ii was found in nfra and frbsp groups, and the highest frequency of score iii was found in plfra group. table 4 shows the comparison of the ari for all adhesive systems. the chi-square test displayed significant differences among all tested adhesive systems. in both ageing groups, the results demonstrated significant differences between fra and plfra groups, fra and frbsp groups. the nonsignificant differences were found between nfra and frbsp, nfra and plfra, and frbsp and plfra groups. the differences between nfra and fra groups were significant in water storage and acid challenge groups. the effect of ageing media on the sbs and ari of the four test adhesive systems was determined by the independent t-test and chi-square test respectively. the results revealed non-significant differences between the water storage and acid challenge groups, as shown in table 5 and table 6. table 1: descriptive statistics of the shear bond strength test of different groups. group adhesive system x2 likelihood ratio d.f. pvalue water storage among all groups 17.421 19.612 9 0.020 nfra-fra 8.978 11.461 3 0.009 nfra-frbsp 9.900 9.908 3 0.823 nfra-plfra 2.633 2.773 3 0.428 fra-frbsp 6.921 8.630 3 0.035 fra-plfra 11.700 14.967 3 0.002 frbsp-plfra 2.800 2.947 3 0.400 acid challenge among all groups 17.171 19.466 9 0.040 nfra-fra 8.662 11.090 3 0.011 nfra-frbsp 0.533 0.541 3 0.910 nfra-plfra 1.143 1.163 3 0.762 fra-frbsp 6.667 8.630 3 0.035 fra-plfra 10.800 13.725 2 0.003 frbsp-plfra 2.476 2.612 3 0.455 j bagh college dentistry vol. 32(4), december 2020 effect of aging media 8 table 2: comparison of the mean shear bond strength test in different groups by anova and post-hoc tukey’s hsd test. table 3: frequency distribution and percentages of adhesive remnant index among different adhesive systems in both ageing groups. table 4: comparison of ari among different adhesive systems in both ageing groups table 5: comparison of the effect of ageing media on the mean sbs of the four test adhesive systems. table 6: comparison of the effect of ageing media on the ari scores distribution of the four test adhesive systems. *continuity correction test discussion the most common adverse effect associated with fixed orthodontic therapy is the white spot lesions around the bonded attachments and its prevalence ranges between 2% and 96%.(17) many studies evaluated the efficacy of fluoride releasing adhesives as non-patient dependent approach and topical fluoride exposure in reducing the enamel demineralization adjacent to the brackets.(6,18,19) comparison adhesive system group tukey’s hsd test anova test pvalue between subgroups pvalue ftest 0.033 nfra-fra 0.000 7.893 nfra water storage 0.582 nfra-frbsp fra 0.000 nfra-plfra frbsp 0.396 fra-frbsp plfra 0.330 fra-plfra 0.011 frbsp-plfra 0.027 nfra-fra 0.000 11.02 9 nfra acid challenge 0.629 nfra-frbsp fra 0.000 nfra-plfra frbsp 0.311 fra-frbsp plfra 0.086 fra-plfra 0.001 frbsp-plfra group adhesive system ari scores 0 i ii iii total water storage nfra n 2 2 5 1 10 % 20.0 % 20.0 % 50.0 % 10.0 % 100.0 % fra n 7 3 0 0 10 % 70.0 % 30.0 % 0.0 % 0.0 % 100.0 % frbsp n 3 3 3 1 10 % 30.0 % 30.0 % 30.0 % 10.0 % 100.0 % plfra n 1 2 3 4 10 % 10.0 % 20.0 % 30.0 % 40.0 % 100.0 % total n % 13 10 11 6 40 % 32.5 % 25.0 % 27.5 % 15.0 % 100.0 % acid challenge nfra n 2 2 4 2 10 % 20.0 % 20.0 % 40.0 % 20.0 % 100.0 % fra n 6 4 0 0 10 % 60.0 % 40.0 % 0.0 % 0.0 % 100.0 % frbsp n 3 2 4 1 10 % 30.0 % 2.0 % 40.0 % 10.0 % 100.0 % plfra n 2 1 3 4 10 % 20.0 % 10.0 % 30.0 % 40.0 % 100.0 % total n 13 9 11 7 40 % 32.5 % 22.50 % 27.50% 17.5 % 100.0 % group adhesive system n mean (mpa) sbs s.d. s. e. min. max. water storage nfra 10 26.524 3.767 1.192 20.190 33.190 fra 10 21.408 3.424 1.083 17.320 28.380 frbsp 10 24.244 4.553 1.440 18.860 31.520 plfra 10 18.346 4.109 1.299 13.330 26.100 acid challenge nfra 10 25.880 3.938 1.245 19.470 31.760 fra 10 20.900 3.403 1.076 15.240 27.240 frbsp 10 23.856 4.030 1.274 19.520 30.061 plfra 10 16.779 3.653 1.155 12.240 23.020 adhesive system group comparison mean differences t-value p-value nfra water storage 0.644 0.374 0.713 (ns) acid challenge fra water storage 0.508 0.333 0.743 (ns) acid challenge frbsp water storage 0.388 0.842 0.713 (ns) acid challenge plfra water storage 1.567 0.835 0.415 (ns) acid challenge adhesive system groups x2 likelihood ratio d.f. p-value nfra water storage 0.444 0.451 3 0.929 (ns) acid challenge fra water storage 0.220 0.000* 1 1.000 (ns) acid challenge frbsp water storage 0.343 0.345 3 0.951 (ns) acid challenge plfra water storage 0.676 0.680 3 0.878 (ns) acid challenge j bagh college dentistry vol. 32(4), december 2020 effect of aging media 9 in the present study, the mean sbs values in all adhesive systems were higher than the clinically acceptable sbs (5.9 to 7.8 mpa) as considered by reynolds(20), which means that all the tested adhesive systems can withstand the shear stress to an acceptable level. according to the results of the shear bond strength test, there were statistically significant differences among the tested adhesive system in water storage and acid challenge groups. in both ageing groups, the nfra had the highest value of mean sbs, while the plfra had the least value of mean sbs among the tested adhesives, but above clinically acceptable sbs. this outcome might be based on that the enamel surfaces in this group were conditioned with 37% phosphoric acid instead of the polyacrylic acid conditioner, this would produce rougher enamel surface, and consequently enhanced the bond strength; this explanation was reported by cacciafesta et al.(21) and tanbakuchi et al.(22) another possible explanation is that the enamel surfaces were adequately wet during the bonding procedure, otherwise the sbs would be adversely affected if the enamel surface was desiccated.(23) the current study demonstrated that there was highly significant difference between the nfra and plfra groups, these observations were congruent with yassaei et al.(24), who concluded that the fuji ortho lc had a significantly reduced sbs values compared to transbond xt for metal and ceramic brackets. the fra group had less sbs value than nfra group, and the difference between these two groups was significant. these results are supported by benkli et al.(25), who examined the sbs of metal and ceramic brackets bonded with different bonding agents and observed that the sbs values were less in the light bond than transbond xt for metal and ceramic brackets. the frbsp group had mildly deceased mean sbs values than nfra group. this may be attributed to the use of a self-etching primer instead of a conventional acid etchant, which reduces the bonding strength as approved by cehreli et al.(26) and scougall-vilchis et al.(27). the result of present study demonstrated that the difference between these two groups was nonsignificant. this outcome is supported by raji et al. (28), who evaluated the sbs of fluoride releasing selfetching primers in comparison with conventional adhesive after thermocycling (500 cycles) and concluded that there were no significant differences in the sbs values between them. the present study observed that the difference between the frbsp and plfra was significant in water storage and acid challenge. also, there were no significant differences between the fra and frbsp, fra and plfra in both groups. these results supported by reicheneder et al.(29), who found that the sbs was higher in light bond than fuji ortho lc but the difference was non-significant, this may be due to the fact that both adhesive systems had fluoridereleasing ability. the analysis of ari in present study showed that the difference between the nfra and fra groups was significant in water storage and acid challenge groups, where the ari score was mainly ii for nfra in first group and 0 for fra in latter group. these results agreed with vicente et al.(30), who found that the transbond xt left significantly more adhesive remnant on enamel surface than light bond. in both ageing groups, the distribution of ari scores in frbsp group ranged between 0 and ii, and the difference in comparison with nfra group was nonsignificant, this may be attributed to the usage of the same adhesive paste (transbond xt) in both groups. these outcomes were consistent with krobmacher et al.(8), and raji et al.(28) as they found that the difference in ari scores distribution between these groups was non-significant and the bond failure mostly occurred with some remnants on the enamel surface. the plfra group had a high frequency of bond failure (score ii and iii), indicating more adhesive remained on enamel surfaces. the current study findings demonstrated that the difference was non-significant between the nfra and plfra groups. these findings are supported by owen et at.(31) who found the rmgics adhere strongly to the enamel surface and weakly to metal in contrast to the composite resins, which bond well to both the enamel and metal surfaces. moreover, the study demonstrated significant differences between fra and plfra, and between fra and frbsp groups. these outcomes are supported by summers et al.(32), who assessed the sbs and ari for orthodontic brackets bonded with the light bond and fuji ortho lc, and found that there was a significant difference in distribution of ari scores between these two groups. with respect to the effect of ageing media, the current study showed that there were no significant differences in the sbs and ari scores distribution among the tested adhesive systems in both ageing groups. these results are supported by navarro et al.(33), who evaluated the sbs values and ari of bonded teeth stored in acidic soft drinks and artificial saliva, and concluded that there were no significant differences between the experimental and control groups, this j bagh college dentistry vol. 32(4), december 2020 effect of aging media 10 agreement may be attributed to the use of nearly the same acid challenge protocol. conclusion 1-the shear bond strength of the fluoride releasing adhesive systems (plfra, fra, frasp) was less than that of the non-fluoride releasing adhesive system, but above the clinically acceptable range. 2-the ageing media did not affect significantly the sbs and ari of the four tested adhesive systems. conflict of interest: none. references 1. wenderoth cj, weinstein m, borislow ai. effectiveness of a fluoride-releasing sealant in reducing decalcification during orthodontic treatment. am j orthod dentofacial orthop. 1999; 116(6), 629-634. 2. maxfield bj, hamdan am, tüfekçi e, shroff b, best am, lindauer sj. development of white spot lesions during orthodontic treatment: perceptions of patients, parents, orthodontists, and general dentists. am j orthod dentofacial orthop. 2012;141(3):337-44. 3. kucuk eb, malkoc s, demir a. microcomputed tomography evaluation of white spot lesion remineralization with various procedures. am j orthod dentofacial orthop. 2016; 150:483–490. 4. alkis h, turkkahraman h, adanir n. microleakage under orthodontic brackets bonded with different adhesive systems. eur j dent. 2015; 9:117-21. 5. pseiner bc, freudenthaler j, jonke e, bantleon hp. shear bond strength of fluoride-releasing orthodontic bonding and composite materials. eur j orthod. 2010: 32(3), 268273. 6. sudjalim tr, woods, mg, manton dj, reynolds ec. prevention of demineralization around orthodontic brackets in vitro. am j orthod dentofacial orthop. 2007; 131(6), 705-e1. 7. oncag g, tuncer av, tosun ys. acidic soft drinks effects on the shear bond strength of orthodontic brackets and a scanning electron microscopy evaluation of the enamel. angle orthod. 2005; 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157(1), 67-72. 20. reynolds ir, von fraunhofer ja. direct bonding of orthodontic attachments to teeth: the relation of adhesive bond strength to gauze mesh size. br j orthod. 1976; 3:9195. 21. cacciafesta v, sfondrini mf, baluga, scribante a, klersy c. use of a self-etching primer in combination with a resinmodified glass ionomer: effect of water and saliva contamination on shear bond strength. am j orthod dentofacial orthop. 2003, 124(4), 420-426. 22. tanbakuchi b, hooshmand t, kharazifard mj, shekofteh k, arefi ah. shear bond strength of molar tubes to enamel using an orthodontic resin-modified glass ionomer cement modified with amorphous calcium phosphate. front dent. 2019, 16(5), 369. 23. movahhed hz, øgaard b, syverud m. an in vitro comparison of the shear bond strength of a resin-reinforced glass ionomer cement and a composite adhesive for bonding orthodontic brackets. eur j orthod. 2005, 27(5), 477-483. 24. yassaei s, davari a, moghadam mg, kamaei a. comparison of shear bond strength of rmgi and composite resin for orthodontic bracket bonding. j dent. (tehran) 2014, 11(3), 282. 25. benkl ya, buyuk sk, atali py, topbas nm, topbaşi, fb. shear bond strength of metallic and ceramic brackets bonded with different new generation composite systems. dent adv res. 2017, 2: 125. doi: 10.29011/2574-7347.100025 26. cehreli zc, kecik d, kocadereli i. effect of self-etching primer and adhesive formulations on the shear bond j bagh college dentistry vol. 32(4), december 2020 effect of aging media 11 strength of orthodontic brackets. am j orthod dentofacial orthop. 2005, 127(5), 573-579. 27. scougall-vilchis rj, ohashi s, yamamoto k. effects of 6 self-etching primers on shear bond strength of orthodontic brackets. am j orthod dentofacial orthop. 2009, 135(4), 424-e1. 28. raji sh, ghorbanipour, r, majdzade, f. effect of clearfil protect bond and transbond plus self-etch primer on shear bond strength of orthodontic brackets. j dent res. 2011, 8(suppl1), s94. 29. reicheneder ca, gedrange t, lange a, baumert u, proff p. shear and tensile bond strength comparison of various contemporary orthodontic adhesive systems: an in-vitro study. am j orthod dentofacial orthop. 2009, 135(4), 422-e. 30. vicente a, bravo la, romero m, josé ortiz a, canteras ma comparison of the shear bond strength of a resin cement and two orthodontic resin adhesive systems. angle orthod. 2005, 75(1), 109-113. 31. owens se, miller bh. a comparison of shear bond strengths of three visible light-cured orthodontic adhesives. angle orthod. 2000, 70(5), 352-356. 32. summers a, kao e, gilmore j, gunel e, ngan p. comparison of bond strength between a conventional resin adhesive and a resin-modified glass ionomer adhesive: an in vitro and in vivo study. am j orthod dentofacial orthop. 2004, 126(2), 200-206. 33. navarro r, vicente a, ortiz aj, bravo la. the effects of two soft drinks on bond strength, bracket microleakage, and adhesive remnant on intact and sealed enamel. eur j orthod. 2011, 33(1), 60-65. الخالصة وهذه ، الثابتة اناألسن تقويم أجهزة بوضع المرتبطة المضاعفات أهم أحد السن سطح على البيضاء البقع آفات تكوين الخلفية: يعتبر لفلوريدا تحرير خاصية مع المختلفة الالصقة األنظمة استخدام. المينا سطح تحت من المعادن لنزع سريريًا واضح مظهر هي اآلفات القاصة ةالرابط القوة تقييم هي الحالية الدراسة اهداف كانت لذا. التقويمية الحاصرة حول المينا من المعادن نزع تقليل إلى يؤدي قد المختلفة. األسنان تقويم لصق لألنظمة الالصقة المادة بقايا ومعامل مؤشرات إلى ئيعشوا بشكل تقسيمها و تقويمية الغراض المقلوعة البشرية العلوية الضواحك من سنًا ثمانون اختيار المواد والطرق: تم لمدة طرالمق الماء في األسنان تخزين فيها يتم األولى المجموعة عليها؛ التقويمة الحواصر وضع بعد( منهما لكل سنًا 04) مجموعتين إلى يمهاتقس يتم مجموعة كل. الحمضي للتحدي األسنان تعريض فيها يتم الثانية والمجموعة سيليزية 03 حرارة درجة عند يوًما 04 محررة غيرال الالصقة لمادة إما التقويمية الحاصرات لتبيت سيستخدم الذي اللصق نظام نوع حسب( قسم لكل أسنان 04) أقسام أربعة التخريش ذاتية تمهيدية و مادة مع للفلوريد المحررة المادة أو ،(fra) الفلوريد الالصقة محررة المادة أو ،(nfra) الفلوريد (frbsp)، الفلوريد محررة ومسحوق لسائل المتضمنة الالصقة مادة أو (plfra .)الرابطة القوة تقييم يتم يوًما، 04مرور بعد بواسطة الالصقة المادة بقايا معامل مؤشر فحص ويتم دقيقة،/ ملم 0 بسرعة( instron) الفحص آلة استخدام بواسطة القصية .مرات 04تكبير بقوة ماسح مكبر ميكروسكوب خزين مجموعتي الت في المختبرة األربعة اللصق أنظمة بين جدا واضحة فروقات وجود القاصة الرابطة القوة اختبار النتائج: أظهر قيمة أعلى( nfra) الفلوريد محررة الغير الالصقة مجموعة المادة أظهرت . في كلتا المجموعتين،المائي و التحدي الحامضي المادة مجموعة ثم ،(frasp) التخريش ذاتية تمهيدية و مادة مع للفلوريد المحررة مجموعة المادة تليها القصية، الرابطة قوة لمعدل تمتلك( plfra) الفلوريد محررة ومسحوق لسائل المتضمنة الالصقة المادة مجموعة كانت بينما ،(fra) الفلوريد الالصقة محررة واضحة اتفروق وجود الحالية الدراسة أظهرت ، الالصقة المادة بقايا موشر بتحليل يتعلق فيما. القاصة الرابطة قوة لمعدل قيمة أقل .المختبرة اللصق أنظمة بين الذي اللصق ظامن في الموجودة تلك من أقل قاصة رابطة قوة تمتلك الفلوريد تحرر التي االسنان لتقويم الالصقة األنظمة االستنتاجات: .سريريًا المقبول المستوى من أعلى ولكنها التزال الفلورايد على يحتوي ال . hanan.doc j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 32 the effect of addition nano particle zro2 on some properties of autoclave processed heat cure acrylic denture base material hussein karim hameed, b.d.s. (1) hanan abdul rahman, b.d.s., m.sc. (2) abstract background: polymethyl methacrylate (pmma) is used in denture fabrication and considered as the most reliable material for the construction of removable prosthodontic appliances. the material is far from ideal in fulfilling the mechanical requirements and the effect of autoclave processing has not been fully determined. the purpose of this study was to evaluate the effect of addition of salinized (zro2) nano fillers in percentages 3%, 5% and 7% by weight on some properties of heat cured acrylic processed the by autoclave and compare it with 0% (control) group . materials and methods: the silanized(zro2) nano-particles was added to pmma powder by weight in three different percentages 3%, 5% and 7%, mixed by probe ultra-sonication machine.two hundred specimens were constructed and processed by autoclave and divided into 5 groups according to the test (each group consist of 40 specimens ) and each group was subdivided into 4 sub-groups according to the percentage of added (zro2) nano-particles( with 10 specimens for each subgroups) . the tests conducted were transverse strength, hardness (shore d), impact strength test, surface morphology and apparent porosity. afm can provide 3d image of the specimen the homogeneity of nanostructure film, roughness of surface and crystallite size. scanning electron microscope sem of control and salinized nano zro2 reveal the nano fillers distribution and it is shaped. results: highly significant increase in impact strength recorded when acrylic (vertex) mixed with 3%, 5% zro2 nano filler, while a non-significant reduction was observed with 7% zro2 addition in comparison to control. non-significant improvement in transverse strength when 3% zro2 was added, 5% nano addition zro2 improved transverse strength significantly while 7% nano addition showed anon significant reduce when these groups compared to the control group .anon significant reduction in the deformity was seen within 3% nano addition zro2 also 5% nano zro2 addition reduce the deformity significantly and significant increase was recorded when 7% nano addition zro2 was add and when these groups are compared to the control group. a significant increase in surface hardness was observed with the addition of (zro2) nano-particles to (pmma) at the percentage of 3%, highly significant increase at 5% and 7% with addition of modified nano-zro2. a non-significant decrease in apparent porosity at 3% and highly significant decrease in apparent porosity at 5% and 7% with addition of modified nano-zro2 were observed. sem results showed a good distribution of the modified nano-zro2 fillers at 3%, 5% and showed aggregation at 7% in the polymer matrix. conclusion: the addition of modified nano-zro2 particles to acrylic resin cured by autoclave improved impact and transverse strength of denture base nano composite containing 5% of nano-zro2. and this strength decreases with further increase of nano-zro2 filler content. also addition of modified nano-zro2 slightly increaseshardness, thesurface roughness and the apparent porosity also decrease by addition of nano zro2 percentage increase. key words: salinized (zro2) nano fillers, pmma. (j bagh coll dentistry 2015; 27(1):32-39). introduction polymethylmethacrylate (pmma) is the most commonly used material in construction of denture base since 1930 (1).this material is not ideal in every respect and it is the combination of various rather than one single desirable of properties that accounts for its popularity and usage. despite its popularity which satisfy aesthetic, simple processing and easy repair, the main problems associated with pmma as denture base material are poor strength particularly under fatigue failure inside the mouth, impact failure outside the mouth (2). in order to overcome these problems, several attempts were made to modify and improve the strength, thermal properties, and hardness of the pmma. (1) master student. department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of prosthodontics, college of dentistry, university of baghdad. these attempts included the addition of filler particles such as zirconia, glass fiber, alumina, tin, and copper or addition of whisker to resin (3-8). recently, much attention has been directed toward the incorporation of in organic nanoparticles into pmma to improve its properties. the properties of polymer nanocomposites depend on the type of incorporated nanoparticles, their size and shape, as well as the concentration and interaction with the polymer matrix (9). nanoparticles were undergone surface treatment with saline coupling agent and embedded into pmma (10). materials and methods 1. surface modification of nano fillers (zro2) the introduction of reactive groups onto fillers surface was achieved by reaction of npropyltrimethoxysilane with zirconium oxide. j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 33 typical process was as follows 30g of nano filler zro2 and 250ml pure toluene were placed into a flask then sonicated at ambient temperature for 20min.after that, the nano filler and toluene were placed into a flask equipped with a magnetic stirrer at room temperature for 10 min. then 1.5g of silane (5% wt. to nano filler) was added drop wisely by sterile syringe under rapid stirrer (750 rpm) for 20 min. the flask was covered by parafilmand the slurry was left standing in flask for 2 days. the solvent (toluene) was removed by rotary evaporator under vacuum at 60°c at rotary 150 rpm for 30 min. after that the modified nano filler was dried in vaccum oven at 60°c for 20 hours. then nano filler stored at room temperature before use (10, 11). the infrared (ir) spectra were performed on shimadzu ftir8400s infra-red spectrophotometer to determine whether or not functional groups of the tmspm have been attached to the nano filler by analyzing the characteristic vibrations of functional groups (10). 2specimens grouping (200) specimens were prepared to be used in the present study. the specimens were divided into (5) groups according to the tests used, for each test (4) subgroups (three for zirconium oxide addition and one control) where each sub group contain ten specimens to be tested. 3-general preparation of test specimens 1. preparation of the acrylic specimens (test specimens): include plastic model preparation 2. proportioning and mixing of the acrylic table 1: percentages and amounts of polymer, monomer and zirconium oxide nano filler powder used in the study zro2 percentage amount of zro2 amount of pmma amount of monomer 0% 0 22g 10ml 3% 0.66g 21.34g 10ml 5% 1.1g 20.9g 10ml 7% 1.54g 20.46g 10ml 3. addition of filler 4. packing 5. curing (fast curing cycle). 6. finishing and polishing. 4-mechanical and physical tests utilized to examine properties evaluations of the mechanical and physical properties of the prepared nano-composite denture base were compared with conventional denture base (heat cure acrylic resin). including: 1. impact strength test i. specimen design the specimens used were prepared as described with dimensions (80mmx 10mm x 4mm ± 0.2mm), international standard iso. 1791. 2000 for unnotched specimens. ten specimens of each concentration were prepared make a total of (40) specimens for impact strength measurements. specimens tested after being conditioned in distilled water at 37°c for 48 hours. ii. testing procedure impact strength test was conducted following the procedure given by the iso 179 with charpy type impact testing instrument. the specimen was supported horizontally at its ends ad struck by a free swinging pendulum which released from a fixed height in the middle. a pendulum of 2 joules testing capacity was used. the scale reading gave the impact energy absorbed to fracture the specimen in joules when struck by a sudden blow. the charpy impact strength of unnotched specimen was calculated in kj/mm2 as given by the following equation: impact strength = x103 (anusavice, 2008) where: e: is the impact absorbed energy in joules. b: is the width in millimeters of the test specimens. d: is the thickness in millimeters of the test specimens. 2. transverse strength i. specimen design the specimens used were prepared as described with dimensions (65mm x 10mmx 2.5mm ± 0.2mm). ten specimens of each concentration make a total of 40 specimens for measurements of transverse strength. all the specimens were immersed in distilled water at 37°c for 48 hours before being tested (ada no. 12, 1999). ii. testing procedure j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 34 the test was achieved using instron testing machine, each specimen was positioned on bending fixture, consisting of 2parallel supports (50)mm apart, the full scale load was 50kg, and the load was applied with cross head speed of 1mm/min by rod placed centrally between the supports making deflection until fracture occurred.the transverse bend strength was calculated using the followingformula: transverse strength = where: p: is the peak load. l: is the span length. b: is the sample width. d: is the sample thickness. (12) 3. surface hardness test i. specimen design: like specimen design in transverse strength ii. testing procedure surface hardness was determined using durometer hardness tester from type (shore d) that was fabricated by time group inc company according to american national standard/american dental association (ans/ada) no. 12, 1999 which is suitable for acrylic resin material? the instrument consists of blunt-pointed indenter 0.8mm in diameter that tapers to a cylinder 1.6mm. the indenter is attached to a digital scale that is graduated from 0 to 100 units. the usual method is to press down firmly and quickly on the indenter and record the maximum reading as the shore “d” hardness, measurements were taken directly from the digital scale reading. five measurements were done on different areas of each specimen (the same selected area of each specimen), and an average of five reading was calculated. 4.apparent porosity test this test method covers procedures for determining apparent porosity by: 1. balance, of adequate capacity, suitable to weigh accurately to 0.001 g. 2. oven, capable of maintaining a temperature of 150 65°c (302 6 9°f). 3. wire loop, halter, or basket, capable of supporting specimens under water for making suspended mass measurements. 4. container—a glass beaker or similar container of such size and shape that the sample, when suspended from the balance by the wire loop is completely immersed in water with the sample and the wire loop being completely free of contact with any part of the container. 5. distilled water. test specimens at least five representative test specimens selected. sharp edges or corners shall be removed. the specimens shall contain no cracks. calculation where: ws: saturated weight wd: dry weight wn: hooked weight 5. surface morphology (afm) most afms use a laser bean deflection system, where a laser reflected from the back of the reflective afm lever and onto a position sensitive detector. afm tips and cantilevers are micro fabricated. typical tips radius is from a few to 10s of nm because the afm relies on the forces between the tip and samples. afm can provide 3d image and we can know the homogeneity of nanostructure film, also roughness of surface and crystallite size. the surface morphology of the prepared sample with different percentage of salinized zro2 was observed by afm type (aa 2000 spm) as shown. 6. scanning electron microscope sem scanning electron microscope of control and salinized nano zro2 fillers with magnification up to (20, 50 and 100) mm to show the nano fillers distribution and its shaped. results 1. characterization of modified nano fillers (zro2) the absorption bands of tmspm can be assigned to the presence of the functional groups, which are two prominent peaks at 2945cm-1 and 2841cm-1 can be attributed to the (c-h) stretching, and the characteristic (c=o) stretching occurs at 1720cm-1,and the characteristic for (c=c) stretching occurs at 1637cm-1 ,for (ch2 and ch3) occurs at 1413cm-1 ,and group of four peaks between 1296cm-1 and 1166cm-1 can be attributed to (c-o-c) stretching, the characteristic for (si-o-ch3) stretching occurs between 400470 cm1. 2. descriptive data of analysis by dependent variable groups: from table (2) which plots the different means of transverse strengths across different concentrations of the incorporated nano-particles dependent on variable groups. j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 35 figure 1:zr-o band ftir spectrum of modified zro2 table 2: descriptive data of analysis by dependent variable groups parameters dependent variable groups control 3% 5% 7% no. mean+s.e no. mean+s.e no. mean+ s.e no. mean+ s.e impact strength 10 6.22+0.330♦ 10 8.50+0.317 10 8.95+0.139♣ 10 6.55+ 0.341 transverse strength 10 93.03+2.09 10 97.13+2.73 10 103.14+3.01♣ 10 92.17+1.72♦ deformation 10 6.97+0.4955 10 5.93+0.2814♦ 10 4.38+1.0397 10 7.73+0.5766♣ hardness 10 80.96+0.4818♦ 10 84.08+0.7402 10 84.53+0.7641 10 84.97+0.8294♣ apparent porosity 10 2.785+0.1465♣ 10 2.291+0.1266 10 1.719+0.1562 10 1.242+0.1339♦ ♣ highest mean in each groups ♦lowest mean in each group 3. multiple comparisons of nanofillers composite with control for dependent variable groups: table (3) showed significant difference between groups was investigated by further complement analysis of data tuky's test. table 3: multiple comparisons of nano filler composite with control for dependent variable groups experimental groups dependent variable by p value for tuky's with significance impact strength transverse strength deformation hardness apparent porosity control & 3% 0.000 hs 0.639 ns 0.686 ns 0.019 s 0.082 ns control & 5% 0.000 hs 0.029 s 0.041 s 0.006 hs 0.000 hs control & 7% 0.835 ns 0.994 ns 0.843 ns 0.002 hs 0.000 hs 3% & 5% 0.804 ns 0.319 ns 0.355 ns 0.972 ns 0.034 s 3% & 7% 0.000 hs 0.486 ns 0.233 ns 0.816 ns 0.000 hs 5% & 7% 0.000 hs 0.015 ns 0.005 hs 0.971 ns 0.098 ns 4. surface morphology (roughness) surface morphological examination was done for all tested groups with afm as shown from figures (2-5) it was appeared that there is a homogenous distribution of the filler with nano surface morphology as the percentage of nano addition increased with an even nano surface roughness table (4) figure 2: afm control (without nano) j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 36 figure 3: afm 3% zro2 figure 4: afm 5% zro2 figure 5: afm 7% zro2 table 4: afm data for sample prepared from acrylic and nano zro2 sample mane roughness average (nm) average grain size (nm) control 62.1 83.41 3% 61.0 53.57 5% 58.9 39.23 7% 50.4 11.71 5. scanning electron microscope test sem examination was done under (20x, 50x, and 100x) mm with deferent magnification. this test was done for all tested groups (control 0%, 3%, 5% and 7%) as shown in fig (6). as appear in the figure (6) the individual particle was in nano scale size and it is spherical shaped with diameter approximately 20-30 nanometers. 100 mm 50 mm 20 mm control sample without nano zro2 100 mm 50 mm 20 mm sample with 3% nano zro2 j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 37 100 mm 50 mm 20 mm sample with 5% nano zro2 100 mm 50 mm 20 mm sample with 5% nano zro2 figure 6: control, 3%, 5%, and 7%): scanning electron microscope shows particles of nano discussion in the present study some mechanical properties of acrylic denture base material (vertex) cured by autoclave are evaluated after the addition of modified silanized nano-zro2nano zirconia (zro2) was used because it is excellent biocompatible material also esthetic because of white color and is less likely to alter esthetic.. the nano-sized zirconia has been successfully used to fabricate nano-composite with highhardness, high refractive index and improved scratch resistance (13). 1. silane coupling agent a properly applied coupling agent can improved physical and mechanical properties and inhibit leaching by prevent water from penetrating along the filler resin interface, also excellent filler to matrix adhesion is needed for minimizing wear. silanization of the nano-filler particles yields a better dispersion, eliminate aggregation and improve its compatibility with organic polymer (14). although zirconates can be used as coupling agents (12). in the present study npropyltrimethoxysilanewas used as a coupling agent. toluene was used as the solvent for n propyltrimethoxysilane to aid in dispersion of npropyltrimethoxysilane to cover all the nano zro2 particles. the atomic number of zirconium (zr) is 40, so it has unsaturated empties orbitals (5s, 4d), the alone pair electron of each (o) present in the coupling agent can attack the unsaturated empties orbitals of zr (form coordination bonds with an inorganic nano-zro2 fillers (15). moreover, due to the presence of more than one active side so this will lead to physical interaction (molecular interaction) by vander waal forces which enhanced the bond strength. both vander waal force and covalent bonding will increase the shear strength and adhesion force (16). 2. impact strength impact strength is defined as the energy required fracturing a material by an impact force (17). the results of impact strength test showed that the addition of modified nano-zro2 powder increased the value of the impact strength compared to control group, 5wt% group has the highest impact strength, but increasing the percentage of modified nano-zro2 to 7wt% lowered the impact strength. the increase in impact strength due to the interfacial shear strength betweennano-filler and matrix is high due to formation of cross-links or supra molecular bonding which cover or shield the nano fillers that in turn prevent propagation of crack. also the crack propagation can be changed by good bonding between nano filler and resin matrix (16, 18). the aggregation of modified nano-zro2 at 7wt%, that lead to the reduction in impact strength because of higher surface area of the fillers, which may reached to µm in size, so stress concentration around this aggregation which lead to crack proportion. also the increase in percentage of modified-nano-zro2 powder effects the interface region lead to lowering of energy dissipation per unit volume and consequently lowers the impact strength (16). similar finding was reported by nabil (15). when he added zirconia nano-particles and found that the impact strength increase at 3% and 5% percentage of addition nano-zro2, than slight decrease at thepercentage 7% addition of nano zro2 fillers. j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 38 3. transverse strength the transverse strength test is one of the mechanical strength tests especially useful in comparing denture base materials in which a stress of this type is applied to the denture during mastication (19). the addition of nano zro2 and curing by autoclave could be attributed to increase in cross linking. cross-linkage provides a sufficient number of bridges between linear macromolecules to form a three-dimensional network that decreases water sorption, decreases solubility, and increases the strength and rigidity of the resin (17). the addition of modified nano-zro2 fillers increased the value of transverse strength significantly compared to control; 5% wt group has the highest transverse strength (result). and increasing the percentage of modified nano-zro2 at 7% wt lowered the transverse strength. the increase in transverse strength that occur with addition of 3 % and 5% wt zro2nanoparticles is due to well dispersion of the very fine size of nano-particles enable them to enter between linear macro molecular chains of the polymer and fill spaces between chains, segmental motions of the macromolecular chains are restricted and lead to increase strength and rigidity of the resin, so this improve fracture resistance and lead to improve transverse strength (20). at the 7%, reduction in transverse strength may be because all spaces between the pmma chains have been filled at 5%, above this percentage the excess fillers caused separation of pmma chains and weak force between them lead to decrease fracture resistance and to decrease in mechanical properties of the polymer. also reduction in transverse strength at 7%wt is due to aggregation of modified nano-zro2 fillers because of higher surface area (reached to µm in size), this aggregation actually caused a micro fracture that weakened the nano-composite at this percentage. "single individual nano filler exhibited no distinct fracture, or single distinct fracture. in contrast, the nano cluster (aggregate) fillers exhibited multiples fractures, the failure occurredalong the lines ofinternal porosity within the aggregate (nano cluster)"(21). similar finding were reported by nabil (15) when he added zerconianano-particles and found that the transverse strength increase with the concentration of nano-fillers at 3% and 5%, and decrease at 7% nano addition of zro2. 4. the deformation test deformation testing evaluates the effect that load has on the shape of a sample.deformation is measured as the percent change in height of a sample, under a specified load, for a specified period of time. the decrease in deformation that occur with addition of 3% and 5% zro2 nanoparticles due to well dispersion of the very fine size of nano-particles enable them to enter between linear macro molecular chains of the polymer and fill spaces between chains, segmental motions of the macromolecular chains are restrict lead to increase rigidity of the resin and decrease the ability to deformation (21). the addition of nano zro2 3%,5 % lowered the deformation, at 7 % the deformation increase due to excess fillers caused separation of pmma chains and weak force between them lead to decrease fracture resistance and to decrease in mechanical properties of the polymer (15). 5. surface hardness hardness defined as the resistance of material to plastic deformation typically measured under an indentation load (17). shore (d) hardness tester was used which is suitable for ensuring the hardness of acrylic resin (22). the significant increase in hardness of the nano-composite at low nano-particle concentration level 3% nano addition zro2 would be dominated by the cross linking density, while highly significant increase in hardness of the nano-composite at 5% and 7% nano addition zro2 may be attributed to the randomly distributed particles of a hard material nano-zro2 into acrylic matrix. similar finding were reported by nabil(15) when he added zerconia nano-particles and found that the surface hardness increase with the increase in the concentration of nano-fillers. 6. apparent porosity apparent porosity in acrylic resin is a complex phenomenon of multifactorial origin. the addition of nano filler lead to decrease the porosity because the nano that fill the space inside the material lead to decrease the number of pores that open on the external surface, also the using the autoclave demonstrated a reduction in porosity in a denture base resin polymerized (23). the well dispersion of the very fine size of nano-particles zro2 enable them to enter between linear macro molecular chains of the polymer and fill spaces between chains (20). that would lead to decrease the apparent porosity at 3%, 5% and 7% respectively. in conclusion; the addition of modified nanozro2 particles to acrylic resin cured by autoclave improves impact and transverse strength of denture base nano composite containing 5% of j bagh college dentistry vol. 27(1), march 2015 the effect of restorative dentistry 39 nano-zro2. and this strength decreases with further increase of nano-zro2 filler content. also addition of modified nano-zro2 slightly decreases the indentation hardness (surface morphology) the apparent porosity also decreases by increase addition of nano zro2 percentage increase. references 1. manappallil jj. basic dental materials. 2nd ed. new delhi: 2007. p: 99-142, 346-377. 2. jagger dc, harrison a, jandt rd. review the reinforcement of dentures. j oral rehabil 1999; 26:185-94. 3. messermith pb, giannelis ep. synthesis and characterization of layered silicate epoxy nanocomposites. chem mater 1994; 6: 1719–25. 4. abboud m, casaubieilh l, morvan f, et al. pmmabased composite materials with reactive ceramic fillers: iv. radiopacifying particles embedded in pmma beads for acrylic bone cements. j biomedical mater res 2000; 53(6): 728-36. 5. meriç g, ruyter ie. bond strength between a silica glass-fiber-reinforced composite and artificial polymer teeth. acta odontol scand 2007; 5: 306-12. 6. ellakwa ae, morsy ma, el-sheikh am. effect of aluminum oxide addition on the flexural strength and thermal diffusivity of heat-polymerized acrylic resin. j prosthodont 2008; 17: 439-444. 7. alhareb ao, ahmad za. effect of al2o3/zro2 reinforcement on the mechanical properties of pmma denture base. j reinf plast compos 2011; 30: 85-3. 8. pisaisitchaijareenont, hidekazutakahashi, norihironishiyama, mansuangarcsorrnukit. effect of different amounts of 3methacryloxypropyltrimethoxysilane on the flexural properties and wear resistance of alumina reinforced pmma. dent mater j 2012; 31(4): 623–8. 9. jordan j, jacob kl, tannenbaum r,shart ma,jasiuk i. expermental trends in polymer nan composites-a review. mater sci eng 2005; 393(1): 1-11. 10. shi j, bao y, huang z, weng z. preparation of pmma-nanomater calcium carbonate composites by in-situ emulsion polymerization. j zhejiang university sci 2004; 5(6): 709-713. 11. ayad nm, badawi mf, fatah aa. effect of reinforcement of high impact acrylic resin with micro zirconia on some physical and mechanical properties. rev clin pesq odontol curitiba 2008; 4: 145-51. 12. anusavice kj. philips science of dental material. 11th ed. middle east and african edition; 2008. p. 143-166, 721-756. 13. zhou sx, wu lm. macromolecular chemistry and physics 2008; 209(11): 1170-1181. 14. erjun t, cheng g, pang x, ma x, xing f. synthesis of nano-zno2/pmma composite micros sphere through emulsion polymerization and uv-shielding property. j colloid and polymer sci 2005; 284(4): 422-8. 15. nabil i. evaluation the effect of modified nano filler addition on some properties of the heat cure acrylic risen denture base material. a master thesis, department of prosthodontics, college of dentistry, university of baghdad, 2011. 16. sun l, ronald fg, suhr j, grodanine jf. energy absorption capability of nano composites: a review. composites sci technol 2009; 69: 2392-409. 17. anusavice kj. philips science of dental materials. 11th ed. st. louis: saunders elsevier; 2011. p. 143-166, 721-756. 18. chen f, zhu k, gan gj, shen s, kooli f. hydrothermal processing of amorphous hydrous zirconia gels in the presence of 1,12 diaminododecane. materials research bulletin 2007; 42: 1128-36. 19. craig rg, power jm. restorative dental material. llth ed. st. louis: mosby; 2002. p.50, 185-195. 20. katsikis n, franz z, anne h, helmut m, andri v. thermal stability of pmma/ silica nanoand micro composites as investigated by dynamic-mechanical experiments. polym degra stability 2007; 22: 1966-76 21. andrew rc, william m, garry jp. fleming the mechanical properties of nanofilled resin based composite. dent mater 2009; 25: 180-7. 22. unalan f, dikbas i. effects of mica and glass on surface hardness of acrylic tooth material. dent. material j 2007; 26(4): 545-8. 23. undurwade jh, sidhaye ab. curing acrylic resin in a domestic pressure cooker: a study of residual monomer content. quintessence int 1989; 20(2): 1239. الخالصة وتعتبر مواد بعیدة عن المثالیة في .سنان وتعتبر من المواد األكثر موثوقیة لبناء األجھزة التعویضیة القابلة لإلزالةاأل اطقم المستخدمة في تصنیع) pmma(میتاكریالت :المشكلة بیان النانویةالمعالجةاوكسید الزركونیوم ثنائي كان الغرض من ھذه الدراسة لتقییم تأثیر إضافة حبیبات .ف لم تحدد بشكل كاملیلیاألوتوكات الطبخ بلمیكانیكیة، وتأثیرالوفاء بالمتطلبات ا .الى مادة االكریلیك ٪7٪، 5٪، 3سطحیا بنسب .األوتوكالفبعد معالجھ المادة ب السطحیة والمسامیة وشكل السطح والصالدة، الصدمةعلى القوة عرضیة، قوة ھذه اإلضافةودراسة تأثیر ٪، 3میثیل میثا أكریالت وزنا في ثالث نسب مختلفة باودرالبوليل النانویةباالوتوكلیف تم اضافھ حبیبات اوكسید الزركونیوم السیطرةالمعالجةباإلضافة إلى المجموعة :المواد والطرق ، وتنقسم كل )عینھ 40تتكون كل مجموعة من (مجموعات وفقا لالختبارات 5ف وقسمت إلى یلیبواسطة األوتوك نموذج 200صنعت .ة صوتیھ فائقة٪، ویخلط بواسطة مسبار آل7٪ و5 وكانت التجارب التي أجریت القوة عرضیة، ). عینات 10وتحتوي كل مجموعة فرعیة على ( النانویةمجموعات فرعیة وفقا للنسب المضافة من اوكسید الزركونیوم 4مجموعة إلى .anovaوقد تم تحلیل النتائج إحصائیا باستخدام اختبار . المسامیة وشكل السطح ,السطحیة دة، والصالالصدمةقوة عند مقارنتھ مع % 7بینما ھناك انخفاض معنوي قد سجل عند أضافھ % 5و% 3یلیك عند اضافھ سجلت زیادة معنویھ في تأثیر القوة العرضیة لالختبار التي تحدث في االكر:النتائج بینما تظھر زیادات معنویھ في اختبار العرضیة عند , % 7و%3سجلت زیاده غیر معنویة في اختبار العرضیة عند أضافھ حبیبات أوكسید الزركونیوم النانویة بنسبھ .مجموعھ السیطرة بینما تظھر زیادة معنویة في قلھ نسبھ التشوھات % 7و% 3تظھر زیادات غیر معنویھ في نسبة التشوھات ضمن النسب المضافة .قارنھ المجامیع بمجموعھ السیطرة عند م% 5أضافھ دة عند أضافھ حبیبات أوكسید الزركونیوم بنسب ھناك تحسن معنوي في قوة الصال.من حبیبات أوكسید الزركونیوم النانویة عند مقارنھ المجامیع بمجموعھ السیطرة % 5عند أضافھ وحدوث % 3عدم ظھور نقصان معنوي في المسامیة عند أضافھ .مقارنة بمجموعھ السیطرة % 7و% 5وھناك زیادة معنویھ ملحوظھ في قوة الصالدة عند أضافھ الحبیبات بنسبھ % 3 ٪ في 7٪، وأظھرت التجمیع في5و% 3بنسب النانویةج فحص المجھر االلكتروني توزیع جید للحبیبات وأظھرت نتائ% . 7و% 5نقصان معنوي ملحوظ في المسامیة عند أضافة .البولیمر و % 5و % 3وبنسب الصدمةتحسن في القوھالعرضیة وقوه أظھرت% 5و % 3ف بنسب یلیسطحیا عن طریق األوتوك النانویةالمعالجةاضافھ حبیبات اوكسید الزركونیوم :االستنتاج .نقصان في المسامیةالظاھریةالسطح و دةلوحظ زیاده في صال % 7 microsoft word 1 alaa falih ortho j bagh college dentistry vol. 32(3), september 2020 the impact of various 1 the impact of various staining substances and immersion time on the stainability of bonded sapphire brackets with three kinds of light cure orthodontic adhesives (an in-vitro study) alaa faleh albo hassan (1), nidhal h. ghaib (2) article doi: https://doi.org/10.26477/jbcd.v32i3.2893 abstract background: the need of the patient for a more reasonable esthetic orthodontic intervention has risen nowadays. thus, orthodontists make use of esthetic orthodontic materials like brackets, ligature elastics, and arch wires. the esthetic brackets come as different forms of materials, such as ceramic brackets, which have their stainability remaining as the most important consideration for the patients and the orthodontists. this study aimed to compare the staining effects of various staining materials, including black tea, cigarette smoke and pepsi, as well as the time effect on the color stability of sapphire ceramic brackets bonded with three kinds of light cure orthodontic adhesives: transbond, resilience and enlight. materials and methods: three hundred sixty sapphire brackets were utilized and divided into three different groups (120 brackets per group) based on the type of bonding material. each group was further subdivided into four subgroups (30 brackets each) based on the media in which the brackets were fully immersed, including distilled water, black tea, cigarette smoke and pepsi. moreover, each of these subgroups were further subdivided, based on the time of immersion relative to each media, into 3 different smaller subgroups (10 brackets each): one day, 7 days and 14 days with incubation at 37°c. a uv-visible type of spectrophotometer was utilized in order to perform a light absorption test. anova and post hoc lsd tests were used for comparison. results: the smoke of cigarette appeared to be the highest potent staining type among the tested materials followed by pepsi and tea. the staining effects of all kinds of staining materials in relation to the bonded brackets color with all adhesive types were raised with increased time of immersion. conclusion: the patient’s cooperation and habits should be taken into consideration when using sapphire orthodontic brackets. in addition, the patients should be instructed to decrease the consumption of staining beverages. keywords: stainability, staining materials, sapphire brackets. (received: 2/7/2019; accepted: 25/8/2019). introduction the kind of esthetic part relative to orthodontic therapy is turning out to be more crucial; thus to enhance esthetics along the treatment, ceramic brackets have been widely used (1,2). generally, ceramic brackets are made of aluminum oxide. there are two different kinds of these brackets: the monocrystalline alumina (sapphire) brackets and polycrystalline alumina (ceramic) brackets. sapphire brackets are basically milled directly from one crystal of sapphire by the use of the tools of diamond. the polycrystalline alumina tends to bind thermally to ensure that the particles are fused together (3-6). the most vital factor in a successful esthetic treatment is regarded as the stability of the color of the esthetic materials utilized. the stainability of the ceramic brackets is of a multifactorial origin (intrinsic and extrinsic factors) (7). (1) assistant lecturer, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. corresponding author:dr.alaafalehm.85@gmail.com the intrinsic discoloration may be the result of inadequate polymerization of adhesives or resins, water absorption, the type of the material's matrix, the size and content of the material particles (7,9), brand, (10) and tone (11). the extrinsic discoloration may be the result of subject's saliva (12), consumption of food containing caffeine (coffee, tea, pepsi), use of mouth rinse, nicotine (13), heat (14) and lipsticks (15). the most frequently consumed materials by iraqi people are tea, pepsi, and cigarette. thus, it is vital to know the impact of these materials in relation to color stability of sapphire brackets. materials and methods three hundred sixty roth type maxillary right central incisors sapphire brackets (perfect clear, hubit company, korea) were utilized in this study. three kinds of light cure orthodontic adhesives namely: transbond xttm (3m unitek/usa), the enlight (ormco/italy) and resilience ® (orthotechnlogy, usa) were used to bond the brackets. black tea (ahmad tea, england), pepsi cola (baghdad company, iraq) and cigarette (gauloises blonde, the european union) as well as distilled j bagh college dentistry vol. 32(3), september 2020 the impact of various 2 water as control media were used as the major staining materials. sample organization the brackets were divided based on the kind of bonding materials into three equal groups; 120 brackets in each: bonded with enlight, transbond xttm and resilience ® orthodontic adhesives. each group was further subdivided into four subgroups based on the staining media (30 brackets for each); the distilled water that served as control group, the black tea, pepsi and the cigarette smoke. in each subgroup, the brackets were subdivided again based on the immersion durations into 1 day, 7 days and 14 days with 10 brackets for each period. bonding process a thin coat of the primer was put in one direction on each bracket base surface using small type of brush. a particular small quantity of the adhesive paste was placed onto the base of the bracket and placed lightly onto a slide of the glass with the use of the bracket holder. the glass slide was mounted directly on the surveyor table (dentaurum, germany), then covered with a celluloid strip, which enables easy separation of the entire bracket adhesive complex. after that, each bracket was subjected to a constant load using 200 gm load fixed on the upper part of the surveyor’s for about 10 seconds just to make sure that the brackets were seated directly under an equivalent force as well as to make sure an equal adhesive thickness is obtained. at that point, the adhesive material excess was taken away from the bracket base area with the use of an explorer without any movement for the seated bracket, then a particular light curing unit (the blue lex ld-109 from taiwan) was used for the photopolymerization of the adhesives for about 5, 10, 20 seconds for the transbond xttm, enlight and the resilience ® adhesives pastes, respectively according to manufacturer instructions. smoke chamber a plastic container was used as a smoke chamber with the use of a rubber tube that is suitable for the cigarette to ensure an equal smoke distribution and exit directly with the use of a portable suction device, known as saliva ejector (hoo3-c, china). the saliva ejector was suitable for creating a negative pressure in order for the smoke to aspirate from the cigarettes, consequently resulting into the impregnation of all of the brackets relative to the materials, which is then contained directly in the smoke, so as to further reproduce in vitro to the oral cavity of the smoker. meanwhile, for matching coverage with respect to the entire brackets to the smoke of the cigarette, the brackets were carefully fixed directly alongside the ligature wires of the stainless steel and placed inside of a chamber, ensuring they are tightened to a stainless steel holder acting as a support that would permit the brackets to remain in similar vertical level, in order for most of the surface part to be exposed to the smoke of the cigarette. staining procedure making the staining solutions ● the tea: by dipping 5 tea bags directly in 500 ml of distilled water that is boiling for about 10 minutes. ● pepsi: for each day, pepsi new cans were utilized. soaking through staining solutions all of the brackets were positioned in a solution inside of a static plastic container and then labeled using sticky labels, and stored in the incubator at 37°c. all the staining solutions were changed daily. the entire storage duration was 14 days. ● the cigarette: twenty sticks of cigarettes were made use of on a daily basis and each of the cigarettes was burned off in a regular time of about 10 minutes in an entire duration of about 14 days. after every 20 sticks of cigarettes are burned, the brackets were then washed with the use of ultrasonic cleaner (vgt-1740qt, china) made for the removal of the remaining smoke substances present in the surfaces of the brackets, then placed back to the container containing the distilled water and further kept in the incubator (memmert from germany) at the temperature of 37°c, until another time of smoke exposure. spectrophotometric analysis the spectrophotometer, known as the uvvisible spectrophotometer (shimadzu, uv-1800, japan), was utilized to perform the readings of color changes, with the range of wavelength of about 380 and 780 ηm with two analytical beam handles. also, a black type of rectangular cardboard piece with a specification of 40×15×0.2 mm alongside a hole located around 1.7 mm directly from the base, was utilized to permit the brackets’ standard arrangement during the color readings. prior to the readings, each bracket was removed from the staining solutions as well as cleaned for one minute by the ultrasonic cleaner and dried on paper towels (16-18). the spectrophotometer was calibrated before the color readings when the chamber was opened and the two black cardboards were fixed (without any hole) to the two analytical j bagh college dentistry vol. 32(3), september 2020 the impact of various 3 beam handles. at this point, the chamber was further shut and the spectrophotometer gave an auto zero order. the impact of the black type of cardboard was excluded, then the spectrophotometer’s chamber was further opened and at this point, the bracket was positioned in a similar particular upright position alongside the black type of cardboard as indicated in figure 1. the chamber was then closed, then the spectrophotometer started to perform the process of scanning, starting from about 800ηm measure of wavelength present in the infrared region to 200ηm measure of wavelength present in the uv region moving across the entire spectrum relating to visible light. meanwhile, the light absorption readings were gotten in the form of a graph from which the quantity of absorbed light relative to a particular measure of the wavelength of about 345ηm can be obtained and used directly within the statistical analysis. figure 1: the bracket was positioned on the analytical beam handle of the spectrophotometer and the blank on the other analytical beam handle. statistical analyses the results were analyzed with the use of the “statistical package of social science” represented by spss version 15 application software alongside windows xp operating system chicago, usa. the statistics used within this study included: 1. descriptive statistic: means, standard deviations, minimum and maximum values. 2. inferential statistics: one way analysis of variance was used to assess any significant difference among groups followed by lsd test to test any statistical critical difference between each two groups. in the statistical evaluation, significance was considered at p<0.05 results the brackets’ quantity of light absorption immersed in different staining materials is shown in tables 1 and 2. in all types of adhesives, cigarette smoke was the most potent staining agent followed by tea and pepsi with a significant difference. the quantity of light absorption of the brackets immersed in different staining materials at different time intervals is shown in tables 3 and 4. the staining effect of all agents, except distilled water, increased with increasing time of immersion. table 1: descriptive statistics of light absorption and media difference in each duration for the brackets bonded with enlight, resilience and transbond adhesives. adhesives duration media descriptive statistics media difference (d.f.=39) mean s.d. min. max. f-test p-value resilience 1 day d.w. 0.35 0.0007 0.349 0.351 1337.071 0.000 pepsi 0.349 0.0011 0.348 0.351 tea 0.365 0.0009 0.364 0.367 cigarette smoke 0.371 0.0010 0.369 0.372 7 days d.w. 0.351 0.0014 0.35 0.353 1691.500 0.000 pepsi 0.356 0.0014 0.355 0.359 tea 0.372 0.0015 0.37 0.374 cigarette smoke 0.391 0.0011 0.39 0.393 14 days d.w. 0.351 0.0014 0.35 0.353 3771.330 0.000 pepsi 0.360 0.0008 0.359 0.362 tea 0.379 0.0012 0.378 0.381 cigarette smoke 0.401 0.0010 0.399 0.402 enlight 1 day d.w. 0.354 0.0008 0.353 0.355 354.234 0.000 pepsi 0.354 0.0010 0.352 0.355 tea 0.358 0.0007 0.357 0.359 cigarette smoke 0.365 0.0008 0.364 0.366 7 days d.w. 0.355 0.0006 0.354 0.356 1415.478 0.000 pepsi 0.356 0.0007 0.355 0.357 tea 0.363 0.0010 0.361 0.364 cigarette smoke 0.376 0.0008 0.375 0.377 j bagh college dentistry vol. 32(3), september 2020 the impact of various 4 14 days d.w. 0.355 0.0006 0.354 0.356 1968.508 0.000 pepsi 0.357 0.0008 0.356 0.358 tea 0.370 0.0012 0.369 0.372 cigarette smoke 0.381 0.0007 0.38 0.382 transbond 1 day d.w. 0.335 0.0006 0.334 0.336 519.821 0.000 pepsi 0.334 0.0016 0.332 0.336 tea 0.340 0.0006 0.339 0.341 cigarette smoke 0.351 0.0011 0.349 0.352 7 days d.w. 0.335 0.0006 0.334 0.336 2248.279 0.000 pepsi 0.338 0.0013 0.335 0.339 tea 0.346 0.0007 0.345 0.347 cigarette smoke 0.363 0.0006 0.362 0.364 14 days d.w. 0.335 0.0006 0.334 0.336 4244.751 0.000 pepsi 0.341 0.0008 0.34 0.342 tea 0.355 0.0010 0.353 0.356 cigarette smoke 0.373 0.0007 0.372 0.374 table 2: difference in the amounts of light absorption according to the staining materials of brackets bonded with enlight, resilience and transbond adhesives. adhesive media 1 day 7 days 14 days mean difference p-value mean difference p-value mean difference p-value resilience d.w. pepsi 0.0005 0.236 -0.005 0.000 -0.0091 0.000 tea -0.0153 0.000 -0.0208 0.000 -0.0281 0.000 cigarette smoke -0.0206 0.000 -0.0394 0.000 -0.0492 0.000 pepsi tea -0.0158 0.000 -0.0158 0.000 -0.019 0.000 cigarette smoke -0.0211 0.000 -0.0344 0.000 -0.0401 0.000 tea cigarette smoke -0.0053 0.000 -0.0186 0.000 -0.0211 0.000 enlight d.w. pepsi 0.0006 0.129 -0.0009 0.016 -0.002 0.000 tea -0.0035 0.000 -0.0077 0.000 -0.0152 0.000 cigarette smoke -0.0106 0.000 -0.0206 0.000 -0.0254 0.000 pepsi tea -0.0041 0.000 -0.0068 0.000 -0.0132 0.000 cigarette smoke -0.0112 0.000 -0.0197 0.000 -0.0234 0.000 tea cigarette smoke -0.0071 0.000 -0.0129 0.000 -0.0102 0.000 transbond d.w. pepsi 0.0007 0.147 -0.0023 0.000 -0.0058 0.000 tea -0.0049 0.000 -0.0105 0.000 -0.0196 0.000 cigarette smoke -0.0158 0.000 -0.028 0.000 -0.0379 0.000 pepsi tea -0.0056 0.000 -0.0082 0.000 -0.0138 0.000 cigarette smoke -0.0165 0.000 -0.0257 0.000 -0.0321 0.000 tea cigarette smoke -0.0109 0.000 -0.0175 0.000 -0.0183 0.000 j bagh college dentistry vol. 32(3), september 2020 the impact of various 5 table 3: descriptive statistics of light absorption and duration difference in each media for the brackets bonded with resilience, enlight and transbond adhesives. adhesives media duration descriptive statistics duration difference d.f.=29 mean s.d. min. max. f-test p-value r es il ie n ce d.w. 1 day 0.35 0.0007 0.349 0.351 3.784 0.360 7 days 0.351 0.0014 0.35 0.353 14 days 0.351 0.0014 0.35 0.353 pepsi 1 day 0.350 0.0011 0.348 0.351 233.820 0.000 7 days 0.356 0.0014 0.355 0.359 14 days 0.360 0.0008 0.359 0.362 tea 1 day 0.365 0.0009 0.364 0.367 324.283 0.000 7 days 0.372 0.0015 0.37 0.374 14 days 0.379 0.0012 0.378 0.381 cigarette smoke 1 day 0.371 0.0010 0.369 0.372 2323.433 0.000 7 days 0.391 0.0011 0.39 0.393 14 days 0.401 0.0010 0.399 0.402 e n li g h t d.w. 1 day 0.354 0.0008 0.353 0.355 4.235 0.250 7 days 0.355 0.0006 0.354 0.356 14 days 0.355 0.0006 0.354 0.356 pepsi 1 day 0.354 0.0010 0.352 0.355 40.433 0.048 7 days 0.356 0.0007 0.355 0.357 14 days 0.357 0.0008 0.356 0.358 tea 1 day 0.358 0.0007 0.357 0.359 407.920 0.000 7 days 0.363 0.0010 0.361 0.364 14 days 0.370 0.0012 0.369 0.372 cigarette smoke 1 day 0.365 0.0008 0.364 0.366 1077.300 0.000 7 days 0.376 0.0008 0.375 0.377 14 days 0.381 0.0007 0.38 0.382 t ra n sb o n d d.w. 1 day 0.335 0.0006 0.334 0.336 0.802 0.459 7 days 0.335 0.0006 0.334 0.336 14 days 0.335 0.0006 0.334 0.336 pepsi 1 day 0.334 0.0016 0.332 0.336 70.796 0.000 7 days 0.338 0.0013 0.335 0.339 14 days 0.341 0.0008 0.34 0.342 tea 1 day 0.340 0.0006 0.339 0.341 891.208 0.000 7 days 0.346 0.0007 0.345 0.347 14 days 0.355 0.0010 0.353 0.356 cigarette smoke 1 day 0.351 0.0011 0.349 0.352 1829.081 0.000 7 days 0.363 0.0006 0.362 0.364 14 days 0.373 0.0007 0.372 0.374 table 4: difference in the amounts of light absorption according to the immersion days of sapphire bracket in the staining media. adhesives duration pepsi tea cigarette smoke mean difference p-value mean difference p-value mean difference p-value resilience 1 day 7 days -0.0068 0.000 -0.0068 0.000 -0.0201 0.000 14 days -0.0109 0.000 -0.0141 0.000 -0.0299 0.000 7 days 14 days -0.0041 0.000 -0.0073 0.000 -0.0098 0.000 enlight 1 day 7 days -0.0023 0.040 -0.005 0.041 -0.0108 0.000 14 days -0.0034 0.011 -0.0125 0.000 -0.0156 0.000 7 days 14 days -0.0011 0.042 -0.0075 0.035 -0.0048 0.000 transbond 1 day 7 days -0.0033 0.000 -0.0059 0.000 -0.0125 0.000 14 days -0.0068 0.000 -0.015 0.000 -0.0224 0.000 7 days 14 days -0.0035 0.000 -0.0091 0.000 -0.0099 0.000 j bagh college dentistry vol. 32(3), september 2020 the impact of various 6 discussion the spread and strength of staining are dependent on the type, amount and duration of exposure to a staining agent (19). the discoloration effect of cigarette might be correlated with its components. there are different components which can cause this discoloration, such as coffee, sugars, cocoa, nicotine, and tar. nicotine, present in a high concentration in the tobacco leaves, can produce salts with acids that are generally water soluble and can be absorbed by brackets and adhesive material. tar is a greasy black liquid that might establish the adhesives and cause their discoloration and this comes in accordance with the findings reported by khazil (20) wasilewski et al. (21) and alandia-roman et al. (22). the discoloration effects of tea were due to the presence of tannin or tannic acid and caffeine. tannic acid can produce complexes not soluble in water with caffeine; these complexes may deposit at the surfaces of the bracket and cause the discoloration. this agrees with the results of khazil (20) and hersek et al.(23). the discoloration effects of pepsi are associated with the presence of caramel artificial coloring. the synthetic colorants present in pepsi have a slight discoloration effect on brackets than normal colorants present in cigar and tea and this comes in agreement with khazil (20). the degree of discoloration of the materials is affected by many factors such as the type, the media, and the time of storage (24) because all types of adhesive used showed color change in all media with time. the time of storage was taken for the purpose of exposing the brackets to severe conditions to evaluate the degree of discoloration; after this time, there is a tendency towards saturation (25,26). deposition of colorant molecules on the resin matrix with time causes the weakening of the resin matrix due to the effect of water, which is a softener of plastics with continuous deposition of the staining materials and chemical degradation of the material surface. conclusion 1. cigarette smoke was the tested medium that had the most influence on the color stability in relation to the light cure adhesive alongside the sapphire ceramic brackets, then tea and lastly pepsi with non-significant effect of distilled water. 2. the time of immersion increasingly affected the color stability in relation to the adhesive materials alongside the sapphire ceramic brackets with the greatest activity noticed at an interval of fourteen days. conflict of interest: none. references 1. ziuchkovski jp, fields hw, johnston wm, lindsey dt. assessment of perceived orthodontic appliance attractiveness. am j orthod dentofacial orthop. 2008; 133:68–78. 2. rosvall md, fields hw, ziuchkovski j, rosenstiel sf, johnston wm. attractiveness, acceptability, and value of orthodontic appliances. am j orthod dentofacial orthop. 2009; 135:276.e1-12. 3. kusy rp. morphology of polycrystalline alumina brackets and its relationship to fracture toughness and strength. angle orthod. 1988; 58:197-203. 4. swartz ml. ceramic brackets. j clin orthod. 1988; 22:82–8. 5. birnie d. ceramic brackets. br j orthod. 1990; 17:71– 5. 6. cacciafesta v, sfondrini mf, ricciardi a, scribante a, klersy c, auricchiom f. evaluation of friction and stainless steel aesthetic self-ligating brackets in various bracket-archwire combinations. am j orthod dentofacial orthop. 2003; 124: 395-402. 7. swartz ml. ceramic brackets. j clin orthod. 1988; 22:82–8. 8. johnston wm, reisbick mh. color and translucency changes during and after curing of esthetic restorative materials. dent mater. 1997; 13: 89-97. 9. sham as, chu fc, chai j, chow tw. color stability of provisional prosthodontic materials. j prosthet dent. 2004; 91:447-52. 10. makinson of. colour changes on curing lightactivated anterior restorative resins. aust dent j. 1989; 34:154-9. 11. uchida h, vaidyanathan j, viswanadhan t, vaidyanathan tk. color stability of composites as a function of shade. j prosthet dent. 1998; 79:372-7. 12. meyer-lueckel h, umland n, hopfenmuller w, kielbassa am. effect of mucina alone in combination with various dentifrices on in vitro remineralization. caries res. 2004; 38: 478-83. 13. prayitno s, addy m. an in vitro study of factors affecting the development of staining associated with the use of chlorhexidine. j periodontal res. 1979; 14:397-402. 14. faltermeier a, behr m, müssig d. in vitro colour stability of aesthetic brackets. eur j orthod. 2007; 29: 354-8. 15. dietschi d, campanile g, holz j, meyer jm. comparison of the color stability of ten new generation composites: an in vitro study. dent mater. 1994; 10: 353-62. 16. mendonça mr, fabre af, goiatto mc, cuoghi oa, martins lp, verri acg. spectrophotometric evaluation of color changes of esthetic brackets stored in potentially staining solutions. rpg rev pós grad. 2011; 18: 20-7. 17. filho hl, maia lh, araujo m v, elias cn , ruellas aco .colour stability of aesthetic brackets: ceramic and plastic. aust orthod j. 2013; 29: 13-19. 18. patil ss, dhakshaini mr, gujjari ak. effect of cigarette smoke on acrylic resin teeth. j clin diagn res. 2013; 7:2056-9. j bagh college dentistry vol. 32(3), september 2020 the impact of various 7 19. sulieman m. an overview of tooth discoloration: extrinsic, intrinsic and internalized stains. dent update. 2005; 32:463-4, 466-8, 471. 20. khazil as. evaluation of color alteration of heatpolymerized acrylic resin. al-mustansiria dent j. 2008; 5: 384-92. 21. wasilewskimde s, takahashi mk, kirsten ga, de souza em. effect of cigarette smoke and whiskey on the color stability of dental composites. am j dent. 2010; 23: 4-8. 22. alandia-roman cc, cruvinel dr, sousa abs, piresde-souza fcp, panzeri h. effect of cigarette smoke on color stability and surface roughness of dental composites. department of dental materials and prosthodontics. ribeira˜ o preto school of dentistry– university of sa˜ o paulo, braz j dent. 2013; 41s: e73 – e79. 23. hersek n, canay s, uzun g, yildiz f. color stability of denture base acrylic resins in three food colorants. j prosthet dent. 1999; 81: 375-9. 24. villalta p, lu h, okte z, garcia-godoy f, powers jm. effects of staining and bleaching on color change of dental composite resins. j prosthet dent. 2006; 95: 13742. 25. asmussen e. factors affecting the color stability of restorative resins. acta odontol scand. 1983; 41: 11-8. 26. stober t, gilde h, lenz h. color stability of highly filled composite resin materials for facings. dent mater. 2001; 17: 87-94. مستخلص ال لقد ازدادت الحاجة لجمالية افضل اثناء عالج االسنان التقويمي مما دفع اطباء تقويم االسنان الستعمال مواد تقويم الهدف من البحث: انتجت الحاصرات التقويمية التجميلية من انواع مختلفة من ).الى االشرطة المطاطية باإلضافة(االسالك والحاصرات التجميليةاالسنان التقويمي ، المواد ( والحاصرات الخزفية الشغل )ceramicة هو لونها ثبات التجميلية ويبقى التقويمية الحاصرات انواع من نوع هي (البيبسي والشاي األسود ودخان مختلفةصممت الدراسة لمقارنة التأثيرات الصبغية لثالثة مواد الشاغل لكل من االطباء والمرضى. على استقرار لون حاصرات ا الضوئية التصلب السجائر) وتأثير الوقت المواد الالصقة ثالثة أنواع من الخزفية المرتبطة مع لتقويم )resilience, enlight and transbond ( تكونت هذه الدراسة من ثالثمائة وستون حاصرة تقويمية ياقوتية , تم تقسيم هذه الحاصرات وفقا لمواد الربط الى ثالث :المواد والطرق مجموعة من مائة وعشرون حاصرة تقويمية وثم قسمت كل مجموعة الى اربع مجاميع فرعية وفقا لمواد مجموعات رئيسية تتكون كل الشاي االسود ,الببسي ودخان السجائر) بواقع ثالثون حاصرة لكل منهم ثم كل مجموعة الى عشرة حاصرات حسب ، الغمر(الماء المقطر تم استخدام االشعة الطيفية .باستعمال الحاضن م37 ر يوما) في درجة حرارةالفترة الزمنية للغمر (يوم واحد, سبعة ايام واربعة عش و(anova) االحصائيةم العملية ااستخدتم .اختبار امتصاص الضوء إلجراء (shimadzu, uv -1800) المرئية فوق البنفسجية (lsd) لتحديد تأثير المواد الملونة. ل الالنتائج: اقوى هو السجائر دخان ان وجد لون الملونةمواد قد على الملونة المواد لجميع الصبغي الببسي.التاثير وثم الشاي يليه . الحاصرات المرتبطة مع جميع انواع المواد الالصقة الضوئية التصلب يزداد مع زيادة وقت الغمر خزفية كذلك يجب توجيه المرضى ان تعاون المريض يجب ان يؤخذ بنظر االعتبار عند استخدام الحاصرات التقويمية ال :االستنتاجات .بتقليل استهالك المشروبات الملونة 7afrah f.doc j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 44 immunohistochemical expressions of akt, atm and cyclin e in oral squamous cell carcinoma afrah a. khalil, b.d.s., m.sc. (1) seta a. sarkis, b.d.s., m.sc., ph.d. (2) abstract background: understanding the pathogenesis and molecular basis of oral squamous cell carcinoma (oscc) has increased rapidly over the past few years that is essential to improve patient's prognosis and treatment modalities. the purpose of this study to evaluate the immunohistochemical expressions of akt, atm, and cyclin e in oral squamous cell carcinoma materials and methods: this study was performed on a forty formalin-fixed paraffin-embedded blocks which histopathologically diagnosed as oral squamous cell carcinoma. all cases were collected from the histopathological laboratory from patients treated surgically at maxillofacial surgery department at ramadi teaching hospital, iraq. results: the immunohistochemical staining of akt showed positive expression in 38 (95%), atm showed positive expression in 38(95%) and cyclin e showed positive expression in 36(90%) of the cases. conclusion: a statically significant correlation was found regarding the immunohistochemical expression of akt with tumor grade and stage, cyclin e with the age group and atm with the clinical appearance. keywords: squamous cell carcinoma, oral cancer, immunohistochemistry, prognosis, expression. (j bagh coll dentistry 2016; 28(3):44-51). introduction oral squamous cell carcinoma (oscc) is a malignant neoplasm of invasive stratified squamous epithelium with varying degrees of squamous differentiation (1). it is capable of locally destructive growth, extensive lymph node invasive and distant metastasis; it occurs in different sites and has many aetiological factors, it is occurring predominantly in alcohol and tobacco-using adults in the 5th and 6th decades of life. more than 90% of malignant neoplasms of the oral cavity and oropharynx are squamous cell carcinomas of the lining mucosae with relatively rare neoplasms arising in minor salivary glands and soft tissues (2). akt, also known as protein kinase b (pkb), is a serine/threonine-specific protein kinase that plays a key role in multiple cellular processes such as glucose metabolism, apoptosis, cell proliferation, transcription and cell migration (3). the main biological consequences of akt activation that are relevant to cancer cell growth can be classified loosely into three categories: survival, proliferation, and growth. activation of the akt pathway in cancer cells leads to epithelial–mesenchymal transition and invasion in vivo. akt induced epithelial–mesenchymal transition involves down regulation of e-cadherin, which appears to result from upregulation of the transcription repressor snail. (1)ph.d. student. department of oral diagnosis, college of dentistry, university of baghdad (2)assistant professor. department of oral diagnosis, college of dentistry, university of baghdad akt has additional effects on tumour induced angiogenesis that are mediated, in part, through hypoxia inducible factor 1α and vascular endothelial growth factor (vegf) (4). akt could promote growth factor-mediated cell survival both directly and indirectly (3). ataxia telangiectasia mutated (atm) is a serine/threonine protein kinase that is recruited and activated by dna double-strand breaks. it phosphorylates several key proteins that initiate activation of the dna damage checkpoint, leading to cell cycle arrest, dna repair or apoptosis. several of these targets, including p53, chk2 and h2ax are tumor suppressors. the protein is named for the disorder ataxia telangiectasia caused by mutations of atm (5). the cell cycle has different dna damage checkpoints, which inhibit the next or maintain the current cell cycle step. there are two main checkpoints, the g1/s and the g2/m, during the cell cycle, which preserve correct progression. atm plays a role in cell cycle delay after dna damage, especially after double-strand breaks (dsbs) (6). cyclin e is a member of the cyclin family. cyclin e binds to g1 phase cdk2, which is required for the transition from g1 to s phase of the cell cycle that determines cell division. the cyclin e/cdk2 complex phosphorylates p27kip1 (an inhibitor of cyclin d), tagging it for degradation, thus promoting expression of cyclin a, allowing progression to s phase. like all cyclin family members, cyclin e forms a complex with cyclin-dependent kinase (cdk2). cyclin e/cdk2 regulates multiple cellular processes by j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 45 phosphorylating numerous downstream proteins (7). cyclin e/cdk2 plays a critical role in the g1 phase and in the g1-s phase transition. cyclin e/cdk2 phosphorylates retinoblastoma protein (rb) to promote g1 progression. hyperphosphorylated rb will no longer interact with e2f transcriptional factor, thus release it to promote expression of genes that drive cells to s phase through g1 phase. several mechanisms lead to the deregulated expression of cyclin e. in most cases, gene amplification causes the overexpression (8). the purpose of this study is to evaluate the immunohistochemical expressions of akt, atm, and cyclin e in oral squamous cell carcinoma. materials and methods this study was performed on a forty formalinfixed paraffin-embedded blocks of oscc cases. all were collected from the histopathological laboratory at maxillofacial surgery department at ramadi teaching hospital. demographical and clinical data provided by surgeon were obtained from the case sheets presented with tumor specimens, including information concerning patient's name, age, gender, clinical presentation, site of tumor, lymph node involvement, distant metastasis (if present). each formalinfixed paraffin-embedded specimen had serial sections were prepared as follows: 5µm thickness sections were mounted on glass slides for routine haematoxylin and eosin staining (h&e), from each block of the studied sample and the control group for histopathological evaluation. three sections 5μm for positive and negative tissue and technical control were taken and mounted on positively charged microscopic slides (biocare medical usa and afco brand china) to obtain a greater tissue adherence. h & e staining was used for reassessment of histopathological examination of the collected samples and control group. for each specific antibody (akt, atm, and cyclin e, abcam-usa), the recommended dilution was applied (1/100, 1/100, and 1/100 respectively). specific expression was demonstrated by the absence of immunostaining in the negative control slides and its presence in recommended positive controls. any positivity in the examined slides for tumor cells the case consider positive, while if no positive expression where noted the case considered negative. the expression for all markers was evaluated semi-quantitatively. it was obtained by counting the number of tumor cells in 5 fields (using 40x objective in most represented areas of sections) and calculate the percentage of tumor cells that labeled a brown cytoplasmic and /or nuclear staining pattern (according to type of expression for each marker). labeling index for each field was calculated using the following equation: (number of positive cells/ number of total cells); the mean value of labeling indices for the five fields was considered to be the label index for the case. the scoring was done under light microscope and assigned to four categories: no expression (ne)= 0 expression, mild (mi)= 1 -20 expression, moderate (mo)= 20-50 expression, strong (st)= 50-100 expression. (figures 1, 2 and 3). chi-square was applied for statistical assessment of clinicopathological and immunohistochemical findings to identify the significant or nonsignificant correlation between them at 95% confidence interval (0.05 level of significance). a. positive cytoplasmic expression in wd (40x) b. positive cytoplasmic expression in md (40x) c. positive cytoplasmic expression in pd (40x) figure 1 (a, b and c): immunohistochemical pattern of expression of akt j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 46 a. positive cytoplasmic expression in wd (40x) b. positive cytoplasmic expression in md (40x) c. positive cytoplasmic expression in pd (40x) figure 2 (a, b and c): immunohistochemical pattern of expression of atm a. positive nuclear expression in wd (40x) b. positive nuclear expression in md (40x) c. positive nuclear expression in pd (40x) figure 3 (a, b and c): immunohistochemical pattern of expression of cyclin e results forty cases of oscc were included in this study with age range between 20-85 years old and mean age 52.4 years old, including 26 (65%) males and 14 (35%) females. the total immunohistochemical expression of akt found in 38 (95%) of the collective cases and as followed; strong in 21 (52.5%) cases, moderate expression in 15(37.5%) cases and low expression in 2 (5%) cases, while no expression was found in 2 (5%) of the cases. concerning the anatomical site and according to the number of the cases included in the study, the recorded percentage of immunohistochemical expression of akt was found in lower lip as a positive expression in 23 (57.5%) cases. the higher percentage of immunohistochemical expression of akt was positive expression in well differentiated scc as seen in 18 (45%) cases, followed by positive moderately differentiated scc as seen in 16 (40%) case, the higher percentage was shown as a positive expression under stage ii in 14 (35%) cases and 14(35%) cases in stage i, followed by 8(20%) cases in stage iii, while 2 (5%) cases showed positive expression in stage iv ( table 1). the total cyclin e positive immunohistochemical expression was found in 36 (90%) of cases as follow; strong in 14 cases (35%), moderate expression in 13 cases (32.5%) and low expression in 9 (22.5%) cases. the highest immunohistochemical expression of cyclin e was located within lower lip as a positive expression in 23(57.5%) cases followed by positive expression in alveolus 5(15%) of the cases. the higher percentage of immunohistochemical expression of cyclin e was positive expression in well differentiated scc as seen in 17(42.5%) cases, followed by j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 47 positive moderately differentiated scc as seen in 14(35%) case and a positive expression under stage ii in 15 (37.5%) cases, followed by 14 (35%) cases in stage i (table 2). the total positive immunohistochemical expression of atm was found in 38 (95%) of the collective cases and as follow; including strong expression in 13 (32.5%) cases, moderate expression in 15 (37.5%) of the cases and low expression in 10 (25%) of the cases while negative expression was found in 2 (5%) of the cases the higher percentage of immunohistochemical expression of atm was shown mainly within lower lip as a positive expression in 24 (60%) cases followed by positive expression in alveolus 6(15%) of the cases and a positive expression in well differentiated scc as seen in 18 (45%) cases. concerning the tumor staging, the higher percentage was shown as a positive expression under stage ii in 14 (35%) cases and 14 (35%) cases in stage i (table 3). discussion tumor or growth in oral region may be divided into benign (noncancerous) and malignant (cancerous). a malignant is life threatening, few patient with malignant tumors that are treatable. knowing more about the pathogenesis of oscc is essential to improve patient's prognosis and treatment modalities (9). cancer research is obtained toward understanding the carcinogenic mechanism by determination of expression and protein immunostaining in oral cancer in comparison with adjacent normal epithelium; highlighting correlation between expression and tumor differentiation. an intensive search for tumor markers based on the molecular alterations in cancerous lesions can be used for efficient diagnosis, prognosis and potential therapeutic targets for different type of human cancer (1). it has been found that in normal cells cyclin e was rapidly down regulated when the cells entered sphase. however, in the tumour derived cell cultures, the levels of cyclin e instead increased in early s-phase and remained high throughout s and sometimes even g2. increased cyclin e levels during s and g2 might affect the tumour cells by causing genomic instability, which is a hallmark of cancer. another interpretation of the rising levels of cyclin e in s-phase in tumour cells is that tumour cells might initiate dna replication prematurely, with a low level of cyclin e, and thereby cyclin e begins to accumulate first after the cells have entered s-phase. the relatively low levels of cyclin e in tumour cells in g1 support this interpretation (10). in this study we found that cyclin e shows a high expression 38(95%) in all oscc lesions and showed increased expression with degree of differentiation from poor to well differentiated; this finding is agreed with the results of zhou et al (11). high expression of cyclin e may play an important role in early stage of carcinogenesis and could be a potential targeted marker to early interfere with cancer progress and stratify high risk patients with precancerous lesion for close surveillance (12). the main biological consequences of akt activation that are relevant to cancer cell growth can be classified loosely into three categories: survival, proliferation (increased cell number), and growth (increased cell size) (4). akt pathway is the major survival pathway in cancer cells, which is frequently upregulated in human tumors (13). in this study we found that akt shows a high expression in positive immunohistochemical staining in 37 (92.5%) of the collective cases of oscc lesions similar to the finding of schlieman et al (24) showed that p-akt expression correlated with higher histological tumour grade in pancreatic cancers and dhawan et al (14) who reported higher incidence of p-akt expression in melanomas. atm plays an essential role in the pathways activated by dna breaks (15). in reaction to various agents that damage dna, atm phosphorylates p53. various reports have shown the association of atm mutation with risk of different human malignancies. the immunoreactivity of atm in this study was expressed in 38 (95%) of the cases of oscc, this finding with agreement (16). the findings of elevated level of atm expression in cases of oscc suggested atm kinase plays a critical role in the dna damage response and its phosphorylation cascade to inhibit the p53mdm2 interaction, which releases p53 to induce p21 and g1 cell-cycle arrest. overexpressed in osccs and might be associated closely with oscc progression by preventing cell-cycle arrest and apoptosis. although atm mainly nucleus localized but we observed that there is a cytoplasmic expression and it is directly proportion with degree of differentiation, this finding in agreement with xiaolan et al (17). j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 48 table 1: clinicopathological finding vs. immunohistochemical expression of akt * (chi square = 15.13; df:6; p=0.0192), * (chi square = 20.85; df:9; p=0.0133) clinicopathological parameter n (%) ne 2 (5%) mi 2 (5%) mo 15(37.5%) st 21(52.5%) total n (%) age group 0-9 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 40(100%) 10-19 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 20-29 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) 30-39 9(22.5%) 0(0%) 2(5%) 1(2.5%) 6(15%) 40-49 5(12.5%) 1(2.5%) 0(0%) 3(7.5%) 1(2.5%) 50-59 11(27.5%) 0(0%) 0(0%) 6(15%) 5(12.5%) 60-69 6(15%) 0(0%) 0(0%) 3(7.5%) 3(7.5%) 70-79 3(7.5%) 0(0%) 0(0%) 0(0%) 3(7.5%) 80-89 4(10%) 1(2.5%) 0(0%) 1(2.5%) 2(5%) gender male 25(62.5%) 1(2.5%) 1(2.5%) 8(20%) 15(37.5%) 40(100%) female 15(37.5%) 1(2.5%) 1(2.5%) 7(17.5%) 6(15%) clinical appearance ulcer 17(42.5%) 1(2.5%) 1(2.5%) 6(15%) 9(22.5%) 40(100%) mass 23(57.5%) 1(2.5%) 1(2.5%) 9(22.5%) 12(30%) anatomical site lower lip 24(60%) 1(2.5%) 2(5%) 7(17.5%) 14(35%) 40(100%) cheek 3(7.5%) 0(0%) 0(0%) 3(7.5%) 0(0%) f.o.m 3(7.5%) 0(0%) 0(0%) 1(2.5%) 2(5%) alveolus (mandible) 7(17.5%) 1(2.5%) 0(0%) 3(7.5%) 3(7.5%) tongue 1(2.5%) 0(0%) 0(0%) 0(0%) 1(2.5%) soft palate 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) tumor grade * wd 18(45%) 0(0%) 1(2.5%) 8(20%) 9(22.5%) 40(100%) md 16(40%) 0(0%) 1(2.5%) 4(10%) 11(27.5%) pd 6(15%) 2(5%) 0(0%) 3(7.5%) 1(2.5%) tumor stage * i 14(30%) 0(0%) 0(0%) 2(5%) 12(30%) 40(100%) ii 15(37.5%) 1(2.5%) 2(5%) 9(22.5%) 3(7.5%) iii 8(20%) 0(0%) 0(0%) 4(10%) 4(10%) iv 3(7.5%) 1(2.5%) 0(0%) 0(0%) 2(5%) j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 49 table 2: clinicopathological finding vs. immunohistochemical expression of atm clinicopathological parameter n (%) ne 2(5%) mi 10(25%) mo 15(37.5%) st 13(32.5%) total n (%) age group 0-9 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 40(100%) 10-19 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 20-29 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) 30-39 9(22.5%) 0(0%) 3(7.5%) 3(7.5%) 3(7.5%) 40-49 5(12.5%) 1(2.5%) 1(2.5%) 3(7.5%) 0(0%) 50-59 11(27.5%) 1(2.5%) 1(2.5%) 5(12.5%) 4(10%) 60-69 6(15%) 0(0%) 3(7.5%) 1(2.5%) 2(5%) 70-79 3(7.5%) 0(0%) 1(2.5%) 1(2.5%) 1(2.5%) 80-89 4(10%) 0(0%) 1(2.5%) 1(2.5%) 2(5%) gender male 26(65%) 0(0%) 7(17.5%) 11(27.5%) 8(10%) 40(100 %) female 14(35%) 2(5%) 3(7.5%) 4(10%) 5(12.5%) clinical appearance * ulcer 17(42.5%) 0(0%) 8(20%) 4(10%) 5(12.5%) 40(100%) mass 23(57.5%) 2(5%) 2(5%) 11(42.5%) 8(20%) anatomical site lower lip 24(60%) 0(0%) 6(15%) 10(25%) 8(20%) 40(100%) cheek 3(7.5%) 0(0%) 0(0%) 1(2.5%) 2(5%) f.o.m 3(7.5%) 1(2.5%) 0(0%) 0(0%) 2(5%) alveolus (mandible) 7(17.5%) 1(2.5%) 4(10%) 2(5%) 0(0%) tongue 1(2.5%) 0(0%) 0(0%) 0(0%) 1(2.5%) soft palate 2(5%) 0(0%) 0(0%) 2(5%) 0(0%) tumor grade wd 18(45%) 0(0%) 5(12.5%) 7(17.5%) 6(15%) 40(100%) md 16(40%) 1(2.5%) 3(7.5%) 6(15%) 6(15%) pd 6(15%) 1(2.5%) 2(5%) 2(5%) 1(2.5%) tumor stage i 14(35%) 0(0%) 4(10%) 4(10%) 6(15%) 40(100%) ii 15(37.5%) 1(2.5%) 4(10%) 8(20%) 2(5%) iii 8(20%) 1(2.5%) 0(0%) 2(5%) 5(12.5%) iv 3(7.5%) 0(0%) 2(5%) 1(2.5%) 0(0%) * (chi square = 8.81; df:3; p=0.031) j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 50 table 3: clinicopathological finding vs. immunohistochemical expression of cyclin e clinicopathological parameter n(%) ne 4(10%) mi 9(22.5%) mo 13(32.5%) st 14(35%) total n(%) age group * 0-9 0(0%) 0(0%) 0(0%) 0(0%) 40(100%) 10-19 0(0%) 0(0%) 0(0%) 0(0%) 0(0%) 20-29 2(5%) 0(0%) 0(0%) 1(2.5%) 1(2.5%) 30-39 9(22.5%) 0(0%) 2(5%) 3(7.5%) 4(10%) 40-49 5(12.5%) 2(5%) 2(5%) 0(0%) 1(2.5%) 50-59 11(27.5%) 2(5%) 2(5%) 2(5%) 5(12.5%) 60-69 6(15%) 0(0%) 1(2.5%) 3(7.5%) 2(5%) 70-79 3(7.5%) 0(0%) 1(2.5%) 2(5%) 0(0%) 80-89 4(10%) 0(0%) 1(2.5%) 2(5%) 1(2.5%) gender male 26(65%) 3(7.5%) 5(12.5%) 8(20%) 10(25%) 40(100%) female 14(35%) 1(2.5%) 4(10%) 5(12.5%) 4(10%) clinical appearance ulcer 17(42.5%) 0(0%) 3(7.5%) 8(20%) 6(15%) 40(100%) mass 23(57.5%) 4(10%) 6(15%) 5(12.5%) 8(20%) anatomical site lower lip 24(60%) 1(2.5%) 5(7.5%) 11(27.5%) 7(17.5%) 40(100%) cheek 3(7.5%) 0(0%) 1(2.5%) 0(0%) 2(5%) f.o.m 3(7.5%) 1(2.5%) 1(2.5%) 0(0%) 1(2.5%) alveolus (mandible) 7(17.5%) 2(5%) 1(2.5%) 1(2.5%) 3(7.5%) tongue 1(2.5%) 0(0%) 0(0%) 0(0%) 1(2.5%) soft palate 2(5%) 0(0%) 1(2.5%) 1(2.5%) 0(0%) tumor grade wd 18(45%) 1(2.5%) 3(7.5%) 8(20%) 6(15%) 40(100%) md 16(40%) 2(5%) 5(7.5%) 3(7.5%) 6(15%) pd 6(15%) 1(2.5%) 1(2.5%) 2(5%) 2(5%) tumor stage i 14(35%) 1(2.5%) 0(0%) 6(15%) 7(17.5%) 40(100%) ii 15(37.5%) 1(2.5%) 6(15%) 5(12.5%) 3(7.5%) iii 8(20%) 1(2.5%) 2(5%) 2(5%) 3(7.5%) iv 3(7.5%) 1(2.5%) 1(2.5%) 0(0%) 1(2.5%) * (chi square = 28.17; 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17(1): 65. eman f.doc j bagh college dentistry vol. 25(2), june 2013 histomorphometric analysis oral diagnosis 70 histomorphometric analysis of bone deposition at ti implant surface dip-coated with hydroxyapatite (in vivo study) athraa y. al-hijazi, b.d.s., m.sc., ph.d. (1) thair l. al-zubaydi, m.sc., ph.d. (2) eman i. mahdi, b.d.s, m.sc. (3) abstract background: synthetic hydroxyapatite,(ca10(po4)6(oh2) can directly bond to bones without infection and fibrous encapsulation, thus is regarded as bioactive and biocompatible. the aim of the study was the estimation of microarchitecture bone parameters include bone mass (gm/cm2) cortical bone width (mm), thread width (mm), marrow space star volume analysis (v*m) and osteoblast, osteocyte cell number. materials and methods: ninety-six (96) commercially pure titanium cpti) used in this study, (48) implants were coated with ha by dipping coating and (48) implants were used as control. they were inserted in (32) newzland white rabbits and followed for 2 & 6 weeks. mechanical torque removal test and histomorphometric analysis of bone microarchiteture were performed for evaluation of osseointegration. results: results revealed, torque values were increased with advancing time for coated and uncoated groups. and specifically dip coated implant showed high value in comparison to control. histomorphometric analysis for bone parameters showed highly significant difference in overall contrasted groups of implant in 2nd and 6th week interval. conclusion: dip coating method is an alternative coating technique for dental implant to enhance better bone implant contact and improve osseointegration. key words: hydroxyapatite, implant surface coating dip-coating histomorohometric analysis. (j bagh coll dentistry 2013; 25(2):70-75). introduction titanium has been widely used as implant materials because of their highly biocompatible properties with relatively low modulus, good fatigue strength, and formability, machinability and corrosion resistance. in addition, hydroxyapatite has been added to tatinum surface as a coating material on orthopaedic and dental implants adding hydroxyapatite to titanium has allowed combining the strength of the metals with the bioactivity of the ceramics hydroxyapatite has helped to promote more rapid osseointgration, this includes direct bony growth and early mineralization at the interface, as well as equivalent or higher bone implant bond strengths and percentage bone contact at the implant interface compared to uncoated titanium implants dip coating: it is an alternative method used in orthopaedic to coat bioactive ceramics such as hydroxyapatite. dip coating used to modify the surface of the implant material and to creat a new surface with totally different properties with respect to the substrate (1) professor. department of oral diagnosis. college of dentistry. university of baghdad. (2) senior scientific researcher, ministry of science technology, baghdad, (3) ph.d. student. department of oral diagnosis. college of dentistry. university of baghdad. bioceramiccoated metallic prostheses and implants by dipping method were shown to display increased levels of biocompatibility when placed in the body environment and these thin coatings were also shown to placed in the body environment and these thin coatings were also shown to impede the corrosion and undesired metal ion transfers from the implant itself calcium hydroxyapatite biomaterial of choice in coating application. dip coating techniques can be described as a process where the substrate to be coated is immersed in a liquid and then withdrawn with a well-defined withdrawal speed under controlled temperature and atmospheric condition the coating thickness is mainly defined by the withdrawal speed, by the solid content and the viscosity of the liquid the aim of the study was the estimation of microarchitecture bone parameters include bone mass (gm/cm2) cortical bone width (mm), thread width (mm), marrow space star volume analysis (v*m) and osteoblast, osteocyte cell number. materials and methods materials -hydroxyapatite powder (merck, darmstadt, germany) -ethanol solvent j bagh college dentistry vol. 25(2), june 2013 histomorphometric analysis oral diagnosis 71 -cpti implants from friatec ag com. (modified and machined to sdiameter of 3.5mm and length 8mm. -torquemeter -formalin 10% (tedia, u.s.a). -formic acid 10% (batch no. 28380, england). -ethanol alcohol 96%. -xylol (analar, u.k.d). -paraffin wax (analar, u.k.d). -haematoxylin and eosin stain (h&e) (dako,u.s.a). -microscopical glass slides and covers (sailchina). -canada balsam (batch no.10862501, european union). -optical microscope (olympus / 542037, japan). methods dip coating was applied on (48) implants for each healing intervals. the rest (48) implants used as control. suspension for ha dip-coating was prepared using 0.2 gm of as a thickning material, which were dissolved in the ethanol solvent provide the gel. surgical procedure was performed to place the implants in suitable size holes in the rabbit tibia, x-ray were taken immediately after surgery to ensure that the implants were properly inserted in their position; sacrification of the animals was done after 2&6 weeks. results all implants at the day of sacrifice were found stable in the bone, they could not be moved with manual force and there were no detectable periimplant defects at the coronal aspect of any implant screw after 2, and 6 weeks of healing periods. the amount of growing bones around the screw implants head was more for the coated than the uncoated one, and in some cases overhang bone deposition were seen over the head of the screw as clearly seen in figure 1. the result of radiographic evaluation appeared that there were no gross changes in the tibial architecture, no areas of radiolucency between implant and adjacent cortical bones in all specimens for radiographical examination as shown in figure 2. mechanical testing the highest mean torque value was recorded for the cpti implant dip-coated with ha which was (14.22, 27.73 n.cm) for 2 and 6 weeks respectively of implantation when compared to the uncoated implant. (11.51, 18.44 n.cm) as shown in table 1. figure 1: photograph for implant coated with ha by dip coating method for 6 weeks duration. notice overhang bone matrix over implant head. figure 2: conventional radiographic view of ti implant coated with ha by dipping method for 6 weeks duration shows cortical bone bounded the implant coronal protion and radiopaque field around the implant (c) uncoated and (ha) coated with hydroxyapptiate by epd method. histomorphometric analysis in general the mean value of all histomorphometric parameters were higher at the coated implant than the uncoated ones. as shown in table (2) the highest mean value of bone mass was obtained at implant dip-coated with ha (0.42gm/ ) at 2 weeks duration when compared with the uncoated one (0.37gm/ ). after 6 weeks of implantation, there were an obvious increase in the mean value of bone mass (0.54gm/ ) the least value was (0.43gm/ ) obtained with control group. width measurment of bone thread in mm was illustreated in table (3). at 6 weeks duration of time, the highest mean value of bone width was (0.79mm) compared with thread width at uncoated implants (0.24mm) with 95% confidence of intervals for means. table (4) shows the mean value of cortical bone width was higher at the coated implant (2.83,3.60mm) at 2 and 6 weeks duration of time respectively, while the mean value of cortical j bagh college dentistry vol. 25(2), june 2013 histomorphometric analysis oral diagnosis 72 bone width was the least with control group (1.87,2.33mm) respectively. the mean value of osteoblasts cell number (ost.no,) were obtained at implants dipcoated with ha was (6.25 cells/m ) at 2 weeks duration. after 6 weeks of implantation, the mean value was (5.75 cell/ m ) as shown in table (5). table (6) illustrates the summary statistics for osteocyle cells number (osc.no.) at implant sites. the mean value of (osc.no.) of coated implant was (2.5,6 cells/ m ) at 2 and 6 weeks duration of implantation when compared with the uncoated ones (2.25,5.5 cells/ m ) respectively. the mean value of marrow space star volume (v*) at 2 weeks duration was (513.25v*) compared with the uncoated ones (870v*). the highest mean value of v* was noticed at uncoated implant (376.75v*) as shown in table (7). for exploration the actual significant differences among all probable pair wise of any two group’s contrasts, least significant difference (lsd) method were applied and their outcomes (table8). discussion the interaction between implant materials and the physiological environment play mainly at the interface. surface topography and chemistry are the most important characteristics that affect cell behavior on artificial materials and that at the end, pilot the entire tissue intergration process due to the similarity with the inorganic components of bony structure, synthetic hydroxyapatite. [ ( )6 ( ] was one of the first material used to coat metals , so metal implant are coated by bioactive ceramics such as hydroxyapatite increase the growth rate of tissue within the pores and to prevent corrosion histomorphometric measurement is a representative test in study the nature of implant tissue surface and has been used by several authers to evaluate boneimplant-interface. the method supply infomation in trabecular width as well as on its distribution and on organization of trabcule in marrow space parameter measuremen were higher in the coated implant than the uncoated and all the parameter increased with time. after 6 weeks of implantation there was an obvious increase in the mean value of bone mass, width of bone thread and cortical bone width at implant sites of all coated implants. these findings show maturation in bone – implant interface resuiting in increasing bone function at the implant site and improving osseointegration mean value of marrow space star volum (v*) were measured in 2 and 6 weeks of implantation, the result showed the highest value of (v*) was recorded in the uncoated implant in 2 and 6 weeks duration in comparison with coated with implant, this result related to the more and faster deposition of bone trabeculae more in thickness that decrease v* value in coated implant for the number of osteoblast and osteocyte cells, osteoblast cells number was obtained as a highest in all coated group compared to uncoated group which showed lowest number of osteoblasts. mean value of osteoblast cell number was higher in 2 weeks of all coated implant but in 6 weeks showed a markdly decrease in number. cell counting revealed that most of surviving osteoblasts cells are settled on the surface site of coated implants because later in 6 weeks duration, more formation and maturation of woven bone so most osteoblast forming bone become entrapted within the matrix as osteocytes cell in 6 weeks period, the number of osteocyte slightly decreased which indicate the maturation of bone after replacement of woven bone by mature trabcular bone with less number of osteocyte focusing in the result obtained in this study, histomorphometric result support the mechanical result, this finding is in agreement with work of nkenke et al as a conclusion; dip coating method is an alternative coating technique for dental implant. histomorphometric analysis for bone mass measurement, cortical bone width, thread width and marrow space star volume (v*) showed to be significantly high in overall groups. references 1. citeau a, guicheux j, vinatieri c, layrolle p, nguyen tp, pilet p, daculis g. in vitro biological effects of titanium rough surface obtained by calcium phosphate grid blasting. biomaterials 2005; 26(2):157-65. 2. balamurugan a,kanna s, rajeswari s. bioactive solgel hydroxyapatite surface for biomedical applications-in vito study. trends biometer artif organs 2002; 16(1):18-20. 3. garcia rg, vargas g, mendez nj, uribe sa. water versus acetone electrophoretic deposition of hydroxyapatite on 316l stainless steel. key eng. mat. 2006; 314: 237-244. 4. schular m, trentin d, textor m, tosatl sg. biomedical interfaces: titanium surface technology for implants and cell carriers. nano medicin 2006; 1(4): 449-463. 5. tkalcec e, sauer m, nonninger r, schmidt h. sol-gel derived hydroxyapatite powders and coating. j materials science 2001; 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16:291-297. 12. vidiga gm, groisman m, gregorio lh, soares ga. osseointegration of titanium alloy and ha-coated implants in health and ovariectomized animals: a histomorphometric study. clin oral impl res 2009; 2:1272-1277. 13. nanci a, whitson sw, bianco p. bone. in: ten cate’s oral histology: nanci a (ed). 7th ed. mosby-year book inc; 2008. 111-144. 14. nkenke e, micheal h, konstanze w, martin r, friedrich w, klous e. implant stability and histomorphometry. accorrelation study in human cadavers using stepped cylinder implants. clinical oral implants research 2003; 14: 601-609. table 1: summary statistics for removal torque test in different studied and suggested of coated materials treated along two weeks and six weeks measured continuously torquetest period material groups n mean s.d. s.e. 95% confidence interval for mean min. max. lower bound upper bound a ft er (2 ) w ee ks hd (dip) control 4 11.51 1.07 0.53 9.81 13.2 10 12.5 coated 4 14.22 0.94 0.47 12.73 15.71 13.75 15.63 a ft er ( 6) w ee ks hd (dip) control 4 18.44 0.81 0.4 17.15 19.72 17.5 19.38 coated 4 27.73 0.46 0.23 27 28.46 27.29 28.13 table 2: summary statistics for bone mass indicator distributed by the different techniques coated in the 2nd and 6th periods of times (per weeks) experiments n mean s.d. s.e. 95% confidence interval for mean min. max. lower bound upper bound hd-2nd w. 4 0.42 0.01 0.01 0.40 0.44 0.41 0.44 control-2nd w. 4 0.37 0.00 0.00 0.36 0.37 0.37 0.37 hd-6th w. 4 0.54 0.02 0.01 0.52 0.57 0.52 0.56 control-6th w. 4 0.43 0.03 0.01 0.38 0.48 0.41 0.47 table 3: summary statistics indicator for thread. wid.mm distributed by the different techniques coated in 6th weeks periods of times experiments n mean s.d. s.e. 95% confidence interval for mean min. max. lower bound upper bound hd-6nd w. 4 0.79 0.01 0.00 0.77 0.80 0.78 0.80 control-6th w. 4 0.24 0.03 0.02 0.19 0.30 0.20 0.28 j bagh college dentistry vol. 25(2), june 2013 histomorphometric analysis oral diagnosis 74 table 4: summary statistics for cortical wid. indicator distributed by the different techniques coated in the 2nd and 6th periods of times (per weeks) experiments n mean s.d. s.e. 95% confidence interval for mean min. max. lower bound upper bound hd-2nd w. 4 2.83 0.05 0.02 2.76 2.91 2.80 2.90 control-2nd w. 4 1.87 0.25 0.12 1.47 2.26 1.60 2.20 hd-6th w. 4 3.60 0.08 0.04 3.47 3.73 3.50 3.70 control-6th w. 4 2.33 0.12 0.06 2.13 2.53 2.20 2.50 table 5: summary statistics for ost. no. indicator distributed by the different techniques coated in the 2nd and 6th periods of times (per weeks) experiments n mean no./ s.d. s.e. 95% confidence interval for mean min. max. lower bound upper bound hd-2nd w. 4 6.25 0.96 0.48 4.73 7.77 5 7 control-2nd w. 4 5.25 0.96 0.48 3.73 6.77 4 6 hd-6th w. 4 5.75 0.96 0.48 4.23 7.27 5 7 control-6th w. 4 5.25 0.96 0.48 3.73 6.77 4 6 table 6: summary statistics for osc. no. indicator distributed by the different techniques coated in the 2nd and 6th periods of times per weeks experiments n mean no./ s.d. s.e. 95% confidence interval for mean min. max. lower bound upper bound hd-2nd w. 4 2.5 0.58 0.29 1.58 3.42 2 3 control-2nd w. 4 2.25 0.5 0.25 1.45 3.05 2 3 hd-6th w. 4 6 0.82 0.41 4.7 7.3 5 7 control-6th w. 4 5.5 0.58 0.29 4.58 6.42 5 6 table 7: summary statistics for v*m indicator distributed by the different techniques coated in the 2nd and 6th periods of times (per weeks) experiments n mean s.d. s.e. 95% confidence interval for mean min. max. lower bound upper bound hd-2nd w. 4 513.25 24.94 12.47 473.56 552.94 480 540 control-2nd w. 4 870 8.16 4.08 857.01 882.99 860 880 hd-6th w. 4 250 24.49 12.25 211.02 288.98 220 280 control-6th w. 4 376.75 36.82 18.41 318.16 435.34 330 420 j bagh college dentistry vol. 25(2), june 2013 histomorphometric analysis oral diagnosis 75 table 8: multiple comparisons for the studied indicators by (lsd) among overall pair wise of the studied parameters of bone microarchitecture at two and six weeks intervals. (i) groups (j) groups bone mass thread. wid.mm cortical wid. ob. no ocs. no v*m sig. sig. sig. sig. sig. sig. hd-2nd w. fn-2nd w. 0.000 0.000 0.000 0.000 0.000 hef-2nd w. 0.032 0.099 0.000 0.000 0.000 control-2nd w. 0.000 0.000 0.174 0.660 0.000 ha-6th w. 0.000 0.650 0.730 0.000 0.000 had-6th w. 0.000 0.000 0.492 0.000 0.000 fn-6yh w. 0.001 0.402 0.492 0.000 0.000 hef-6th w. 0.000 0.000 0.009 0.000 0.000 control-6th w. 0.605 0.000 0.174 0.000 0.000 control-2nd w. ha-6th w. 0.000 0.000 0.305 0.000 0.000 had-6th w. 0.000 0.000 0.492 0.000 0.000 fn-6yh w. 0.000 0.000 0.046 0.000 0.000 hef-6th w. 0.000 0.000 0.000 0.000 0.000 control-6th w. 0.000 0.000 1.000 0.000 0.000 hd-6th w. fn-6yh w. 0.000 0.883 0.000 0.174 0.004 0.433 hef-6th w. 0.339 0.001 0.000 0.002 0.012 0.000 control-6th w. 0.000 0.000 0.000 0.492 0.381 0.000 taghreed f.doc j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral diagnosis 99 assessment of serum and salivary malondialdehyde in patients with oral lichen planus aws waleed abbas, b.d.s., m.sc. ( 1) taghreed fadhil zaidan, b.d.s., m.sc., ph.d. (2) abduladheem y. abbood al-barrak, b.sc., m.sc., ph.d. (3) abstract background: free radicals are common consequences of normal aerobic cellular metabolism. oxidative stress resulting from the increased production of free radicals and reactive oxygen species and/or a decrease in antioxidant defense leads to damage of biological macromolecules and dysregulation of normal metabolism and physiology. oral lichen planus (olp) is a chronic inflammatory oral mucosal disease of unknown cause. it has been proven that the imbalances in free radical levels and reactive oxygen species with antioxidants may play a key role in the onset and evolution of several inflammatory oral pathologies. the aim of this study was to assess the role of oxidative stress in the pathogenesis of olp through the study of serum and saliva malondialdehyde as a marker of oxidative stress. methods: the study included (48) patients with olp (21) with the reticular form and (27) with erosive form and (32) healthy looking volunteers that were age-matched with the patients. serum and saliva malondialdehyde was measured by reacting with thiobarbituric acid under acidic conditions and heating to a pink color that measured spectrophotometricaly at 532 nm. results: the mean of serum and saliva malondialdehyde in oral lichen planus patients group was significantly higher than that of control group (p<0.01 and p<0.05 respectively) and there was no statistically significant differences in serum and saliva malondialdehyde when compared between reticular and erosive forms (p>0.05). the study showed that there was no statistically significant correlation between serum and saliva malondialdehyde levels in olp patients group (r= 0.053, p>0.05). conclusion: increased serum and salivary malondialdehyde levels refer to the role of oxidative stress in the pathogenesis of olp. keywords: oral lichen planus, malondialdehyde, oxidative stress, serum, saliva. (j bagh coll dentistry 2014; 26(2): 99102). introduction oral lichen planus (olp) is a chronic inflammatory disease of unknown etiology (1). however, the precise cause is unknown, activated cytotoxic t-cells was located close to damaged basal cells which may suggest that they are responsible for the damage and supports the claim that a cell-mediated immune response participates actively in local pathogenetic mechanisms in olp (2). basically there are two classes of oral lesions: reticular and erosive (3). the majority of cases of lichen planus present as white lesions. an erosive form of this disease presents as chronic multiple oral mucosal ulcers. erosive lesions of lichen planus occur in the severe form of the disease when extensive degeneration of the basal layer of epithelium causes a separation of the epithelium from the underlying connective tissue (4). in the healthy human body, there is an approximate balance between production of reactive species and antioxidant defences. tissue injury in human disease is accompanied by an imbalance in the oxidant/ antioxidant status, (1) ph.d. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. (3) assistant professor, department of microbiology, college of medicine, al-mustansiriya university producing oxidative stress. the resulting increased oxidative damage to biomolecules may play an important role in the pathology of several human diseases and is amenable to therapeutic intervention with appropriate antioxidants (5). increasing appreciation of the causative role of oxidative injury in many disease states places great importance on the reliable assessment of lipid peroxidation. malondialdehyde (mda) is one of several low-molecular-weight end products formed via the decomposition of certain primary and secondary lipid peroxidation products (6). the purpose of this study is to evaluate the oxidative stress and its role in the pathogenesis of olp through the study of serum and saliva mda. materials and methods the study included 48 patients with olp which divided into 21 patients with the reticular form and 27 patients with erosive form and 32 healthy looking volunteers that were ageand sexmatched with the patients. all of the olp patients were diagnosed clinically, and the diagnoses were confirmed through histopathologic examination according to the modified who diagnostic criteria for olp by van der meij and van der waal (7). j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral diagnosis 100 blood and saliva were collected from each subject then the supernatant serum and saliva was aspirated and transferred immediately into eppendorf tubes and frozen at -20 °c for subsequent analysis. malondialdehyde (mda), lipid peroxidation end products, react with thiobarbituric acid under acidic conditions and heating to a pinkish color that measured spectrophotometricaly at 532 nm (8). results the mean age of the patient group was 50.96 ±10. 55 with female predilection 52.1%. the present study showed that the mean level of serum mda in patients with olp (4.725±1.634 µmol/l) was significantly higher (p<0.001) by using t-test than that of control group (1.626±0.712 µmol/l). (table 1) (figure 1) the mean level of saliva mda in patients with olp (0.972±0.433 µmol/l) was significantly higher (p<0.05) by using t-test than that of control group (0.732±0.358 µmol/l). (table 2) (figure 1). statistically, there was no-significant difference in serum and saliva mda level between erosive and reticular olp patients groups. (table 3). this study showed that there was no statistically significant correlation (r =0.053, p>0.05) between serum and saliva measurements of mda in patients with olp. (figure 2) table 1: mean of serum mda in olp patients and controls serum mda (µmol/l) patients controls no. 48 32 mean±sd 4.725±1.634 1.626±0.712 standard error of mean 0.236 0.126 mode 2.88 1.88 range 2.68-9.48 0.52-3.48 percentile 05th 2.88 0.60 25th 3.44 1.04 50th (median) 4.32 1.62 75th 6.10 1.98 95th 7.20 3.44 99th 9.48 3.48 p value 0.0001** ** highly significant using students-t-test for difference between two independent means at 0.01 level table 2: mean of saliva mda in olp patients and controls saliva mda (µmol/l) patients controls mean±sd 0.972±0.433 0.732±0.358 standard error of mean 0.074 0.070 mode 0.88 0.56 range 0.48-2.12 0.12-1.40 percentile 05th 0.52 0.32 25th 0.64 0.48 50th (median) 0.84 0.58 75th 1.24 1.04 95th 2.00 1.40 99th 2.12 1.40 p value 0.026* *significant using students-t-test for difference between two independent means at 0.05 level. table 3: mean and significant level of serum and saliva mda between reticular and erosive forms of olp patients group mda (µmol/l) type reticular erosive p value serum 4.703 ± 1.818 4.742 ± 1.512 0.935 saliva 0.994 ± 0.426 0.956 ± 0.448 0.804 j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral diagnosis 101 discussion chronic inflammation is a pathological condition characterized by continued active inflammation response and tissue destruction. inflammatory process induces oxidative stress and reduces cellular antioxidant capacity. excessive production of free radicals react with cell membrane fatty acids and proteins impairing their function permanently (9). it has been proven that the imbalances in free radical levels and reactive oxygen species with antioxidants may play a key role in the onset and evolution of several inflammatory oral pathologies (10). at the cellular level, oxidant elicits responses ranging from enhanced survival to cell death (11). several lines of experimental evidence recognize the mitochondrial dysfunction as one of the important mediators of apoptosis (12). the mitochondria are sensitive to changes in the redox state of the cell. several studies have shown that the global shutdown of mitochondrial function under conditions of the oxidative stress could contribute to apoptosis (13). reactive oxygen species also appear to play an important role in mediating fas-dependent apoptosis (14) sustained by the observation that fas-induced apoptosis were completely abolished by antioxidants such as glutathione (15). anshumalee et al. (16); sezer et al. (17) and anshumalee and shashikanth (18) reported that ros may be involved in the pathogenesis of the lp. the present study demonstrated that serum mda levels were significantly higher in olp than in controls. these findings are in accordance with studies by sezer et al. (17), rai et al. (19), aly and shahin (20), upadhyay et al. (21) and scrobota et al. (22), and supported the concept that free radical mediated lipid peroxidation may be involved in the patho-physiologic mechanisms of olp. from the other hand, the present study revealed that salivary mda levels were significantly higher in olp than in controls, which were consistent with previous studies by agha-hosseini et al. (23) and ergun et al. (24). saliva offers an alternative to serum as a biological fluid that can be analyzed for diagnostic purposes. saliva contains locally produced as well as serum-derived markers that have been found to be useful in the diagnosis of a variety of systemic disorders. whole saliva can be gathered in a non-invasive manner by individuals with modest training, including patients. however, levels of certain markers in saliva are not always a true reflection of their levels in serum. the transfer of serum constituents which are not part of the normal salivary constituents into saliva is related to the physicochemical characteristics of these molecules. salivary composition can be determined by the method of collection and the degree of stimulation of salivary flow. furthermore, salivary proteolytic enzymes can affect the stability of certain diagnostic markers. some particles are also degraded during intracellular diffusion into saliva (25). these limitations opposed the diagnostic potential of saliva and may explain what the present study showed that there was no significant correlation between serum and saliva mda levels in olp patients group. references 1schlosser bj. lichen planus and lichenoid reactions of the oral mucosa. dermatologic therapy 2010; 23: 251–67. 4.725 0.972 1.626 0.732 0 2 4 6 8 serum of patients saliva of patients serum of controls saliva of controls mean mda (µmol/l) figure 1: mean of mda conc. in serum and saliva of olp patients and control groups figure 2: correlation between serum and saliva mda in olp patients group j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral diagnosis 102 2kilpi am. activation marker analysis of mononuclear cell infiltrates of oral lichen planus in situ. scand j dental res 1987; 95:174-80. 3neville bw, damm dd, allen cm, bouquot je. dermatologic diseases. oral and maxillofacial pathology. 2nd ed. wb saunders co.; 2002. 4greenberg m s. ulcerative, vesicular, and bullous lesions. in: greenberg m s, glick m. burket’s oral medicine diagnosis and treatment. 10th ed. bc decker inc; 2003 5halliwell b. free radicals and other reactive species in disease. in: encyclo of life sciences; 2005. available from: http://www.els.net 6janero dr. malondialdehyde and thiobarbituric acidreactivity as diagnostic indices of lipid peroxidatin and peroxidative tissue injury. free radical biology and medicine 1990; 9(6): 515-40. 7van der meij eh, van der waal i. lack of clinicopathologic correlation in the diagnosis of oral lichen planus based on the presently available diagnostic criteria and suggestions for modifications. j oral pathol med 2003; 32:507–12. (cited by: hiremath sks, kale ad, charantimath s. oral lichenoid lesions: clinico-pathological mimicry and its diagnostic implications. indian j dental res 2011; 22 (6): 827-34). 8shah sv, walker pd. evidence suggesting a role for hydroxyl radical in glycerol induced acute renal failure. am j physiol 1988; 255(3): f438-43 9khansari n, shakiba y, mahmoudi m. chronic inflammation and oxidative stress as a major cause of age-related diseases and cancer. recent pat inflamm aller drug discov 2009; 3: 73-80 10battino m, ferreiro m s, gallardo i, newman h n, bullon p. the antioxidant capacity of saliva. j clin periodontol 2002; 29(3):189-94. (cited by: abdolsamadi hr, goodarzi mt, mortazavi h, robati m, motemaye f. comparison of salivary antioxidants in healthy smoking and non-smoking men. chang gung med j 2011; 34(6): 607-11) 11martindale jl, holbrook nj. cellular response to oxidative stress: signaling for suicide and survival. j cellular physiol 2002; 192(1):1-15. 12marzo i, susin sa, petit px, ravagnan l, brenner c, larochette n, zamzami n, kroemer g. caspases disrupt mitochondrial membrane barrier function. febs lett 1998; 427: 198-202. 13zamzami n, susin sa, marchetti p, hirsch t, monterrey i g, castedo m, kroemer g. mitochondrial control of nuclear apoptosis. j exp med 1996; 183 1533-1544. (cited by: kannan k, jain sk. review, oxidative stress and apoptosis. pathophysiol 2000; 7(27): 153-63). 14aronis a, melendez j a, golan o, shilo s, dicter n, tirosh o. potentiation of fas-mediated apoptosis by attenuated production of mitochondria-derived reactive oxygen species. cell death and differentiation 2003; 10(3): 335–44. 15gulbins e, brenner b, schlottmann k, welsch j, heinle h, koppenhoefer u, linderkamp o, coggeshall km, lang f. fas-induced programmed cell death is mediated by a ras-regulated o2synthesis. immunology 1996; 89: 205–12. 16anshumalee n, shashikanth mc, sharma s. oxidative stress and oral lichen planus: a possible association? cusp 2007; 4(2): 31–4. (cited by: aly dg, shahin r. oxidative stress in lichen planus. acta dermatoven alpina panonica et adriat 2010; 19 (1): 3-11). 17sezer e, ozugurlu f, ozyurt h, sahin s, etikan i. lipid peroxidation and antioxidant status in lichen planus. clinical and experimental dermatology 2007; 32:430–4. 18anshumalee n, shashikanth mc. efficacy of oral lycopene in management of lichen planus [dissertation]. [bangalore]: rajv ghandi university of health sciences, bangalore. april 2007; 91-119. (cited by: aly dg, shahin r. oxidative stress in lichen planus. acta dermatoven alpina panonica et adriat 2010; 19 (1): 3-11). 19rai b, kharb s, jain r, anand sc. salivary lipid peroxidation product malonaldehyde in pre-cancer and cancer. adv med dent sci 2008; 2(1): 7–8. 20aly dg, shahin r. oxidative stress in lichen planus. acta dermatoven alpina panonica et adriat 2010; 19(1): 3-11 21upadhyay r b, carnelio s, shenoy r p, gyawali p, mukherjee m. oxidative stress and antioxidant defense in oral lichen planus and oral lichenoid reaction. scand j clin lab invest 2010; 70: 225-8. 22scrobota i, mocan t, catoi c, bolfa p, muresan a, baciut g. histopathological aspects and local implications of oxidative stress in patients with oral lichen planus. rom j morphol embryol 2011; 52(4):1305–9 23agha-hosseini f, dizgah im, mikaili s, abdollahi m. increased salivary lipid peroxidation in human subjects with oral lichen planus. inter j dental hygiene 2009; 7(4): 246-50 24ergun s, troşala sc, warnakulasuriya s, özel s, önal a e, ofluoğlu d, güven y, tanyeri h. evaluation of oxidative stress and antioxidant profile in patients with oral lichen planus. j oral pathology and medicine 2011; 40: 286–93 25kaufman e, lamster ib. the diagnostic applications of saliva-a review. critical reviews in oral biology medicine 2002; 13(2):197-212. http://www.els.net mays f.doc j bagh college dentistry vol. 27(3), september 2015 antibacterial effects oral and maxillofacial surgery and periodontics 102 antibacterial effects of green tea extracts on aggregatibacter actinomycetemcomitans (in-vitro study) mays jamal mageed, b.d.s. (1) saif sehaam saliem, b.d.s., m.sc. (2) abstract background: green tea is made from the leaf of the plant “camellia sinensis”. green tea is reported to contain thousands of bioactive ingredients including catechins which have shown great promise for having antimicrobial effects. periodontal diseases represent one of the most prevalent diseases around the world and the main etiologic factor behind it, is plaque accumulation, in addition certain kinds of bacteria have been detected frequently in subjects suffering from periodontitis, several studies suggested that the outcome of periodontal treatment is better if particular pathogens including aggregatibacteractinomycetemcomitans can no longer be detected after therapy. materials and methods: plaque samples were collected from 20 patients suffering from chronic periodontitis with probing pocket depth of at least 6 mm, aggregatibacteractinomycetemcomitans (a.a) was isolated and diagnosed according to morphological characteristics and biochemical tests. green tea leaves were extracted by using water and alcohol. the first experiment involved testing the sensitivity of a.a to different concentrations of the extracts using agar well diffusion method,the second experiment involved determination of the minimum inhibitory concentration and then determination of the minimum bactericidal concentration of the extract against the bacteria, laboratory analysis of green tea extracts using high pressure liquid chromatography (hplc) was performed. results: both green tea extracts were effective in inhibition of aggregatibacteractinomycetemcomitans using agar well diffusion method, 90% and 100% concentrations of alcoholic extract showed larger inhibition zones than chlorhexidinegluconate 0.2% with statistically significant difference, chx showed higher inhibition zones than all aqueous extract concentrations.the mic (minimum inhibitory concentration) of alcoholic green tea extract that inhibit aggregatibacteractinomycetemcomitans growth was 60%, the mic of aqueous green tea extract that inhibits aggregatibacteractinomycetemcomitans growth was 70%.the mbc (minimum bactericidal concentration) of alcoholic green tea extract that killsaggregatibacteractinomycetemcomitans was 80%, the mbc of aqueous green tea extract that kills aggregatibacteractinomycetemcomitans growth was 90%. hplc analysis of aqueous and alcoholic green tea extracts revealed that alcoholic extract contained higher concentration of egcg while aqueous extract had higher content of catechin and epicatechin. conclusion: green tea extracts were effective against aggregatibacteractinomycetemcomitans, alcoholic green tea extract showed inhibition ability more than the aqueous green tea extract and more than chx and it showed bactericidal activity at 80%,90% and 100% concentrations. key words: green tea extracts, catechins, aggregatibacteractinomycetemcomitans. (j bagh coll dentistry 2015; 27(3):102-108). introduction green tea is one of the most popular beverages consumed worldwide, moreover, during the last two decades it has received much attention in regard to its beneficial effects on various human health problems (1). tea prepared from camellia sinensis is of three types: non-fermented green tea that is pan fried or steamed and dried to inactivate its enzymes, fermented black tea and semifermented oolong tea. green tea with active chemical ingredients possesses diverse pharmacological properties which are linked to lower incidence of some pathological conditions including oral cancer, dental caries, stroke, cardiovascular diseases and obesity (1-3). the health-promoting effects of green tea are mainly attributed to its polyphenol contents commonly referred to as catechins. there are four main types of catechins: epigallocatechin-3gallate (egcg), epigallocatechin, epicatechin-3 (1)assistant lecturer, dijla university college, faculty of dentistry. master student at the time of study conduction. (2) assistant professor, department of periodontics, college of dentistry, university of baghdad. gallate and epicatechin (2). the polyphenol contents of green tea have been reported to inhibit varieties of pathogenic bacterial growth such as helicobacter pylori, methicillin-resistant staphylococcus aureus, streptococcus mutans, streptococcus sobrinus, salmonella typhi, shigella dysentery, shigellaflexneri and vibrocholera(2, 4,5,6,7,8) periodontal disease and bacteria: periodontitis is a chronic slowly progressive polymicrobial infectious disease which affects the entire tooth-supporting tissues. this infection is characterized by destruction of alveolar bone, periodontal ligaments and gingival pocket formation which consequently leads to tooth loss. periodontitis is known to be caused by subgingival plaque bacteria including aggrecatibacteractinomycetemcomitans, prevotellaintermedia, porphyromonasgingivalis, tannerellaforsythusandfusobacteriumspecies. these bacteriaare frequently isolated from j bagh college dentistry vol. 27(3), september 2015 antibacterial effects oral and maxillofacial surgery and periodontics 103 gingival pocket and subgingival plaques of patients with periodontitis (9). during the last two decades, it has been shown that aggrecatibacteractinomycetemcomitans can be regarded as a major pathogen in destructive periodontal diseases (10-12), it was also found that a.a is associated with systemic diseases (13). porphyromonasgingivalis which is a member of the highly investigated black pigmented bacteroids, it comprises high proportion of the subgingivalmicrobiota in periodontal pockets (11,14). several studies suggested that the outcome of periodontal treatment is better if particular pathogens especially aggrecatibacteractinomycetemcomitans and porphyromonasgingivalis can no longer be detected after therapy (15-19). however despite the fact that non-surgical mechanical periodontal treatment as well as self performed plaque control are effective in reducing the numbers of aggrecatibacteractinomycetemcomitans and porphyromonasgingivalis at periodontal sites, these micro-organisms re-establish themselves rapidly in most subjects (20). in the present study wewill investigate the inhibitory activity of green tea extract on some clinically isolated periodontopathic bacteria which is aggrecatibacteractinomycetemcomitans. materials and methods: human sampling: plaque samples were collected from twenty systematically healthy patients suffering from chronic periodontitis, the plaque samples were taken from periodontal pockets with probing pocket depth (ppd) of at least six mm depth,(ppd) was measured from the gingival margin to the most apical extent of the periodontal pocket, the plaque samples were obtained from the deepest part of the periodontal pocket using a sterilized curette. the collected plaque is put on a swab that is inserted immediately into a transfer media to preserve the sample , then the sample was spread on blood agar media and incubated anaerobically using anaerobic jar and anaerobic gas bags in the incubator for 72 hours within a period of less than 30 minutes from taking the sample from the patient. extraction procedures to obtain green tea extracts: 1aqueous extract: 100 grams of dry green tea leaves were put in a glass jar then 500ml of distilled water were added afterwards the glass jar was put in water bath (50o c) for two hours then it was left over night at room temperature, the next morning filtration was done first using gauze to get rid of the large particles of green tea leaves then the resultant liquid was filtered using a sterile whatman filter paper no1., the filtered extract was concentrated under vacuum below 40oc using a rotaevaporator for five hours (21). 2-alcoholic extract: 100 grams of dry green tea leaves were put in a glass jar then 500ml of alcohol (96% ethanol alcohol) were added, the infusion was put in a shaker for 48 hours after that filtration was done first using gauze to get rid of the large particles of green tea leaves then the resultant liquid was filtered using a sterile whatman filter paper no1., the filtered extract was concentrated under vacuum below 40oc using a rotaevaporator for one hour(21). both extracts were kept in tightly closed screw bottles and kept in the refrigerator. identification and isolation of microorganisms: both micro-organisms were identified according to their morphological characteristic, gram stain, biochemical tests and their antibiotic sensitivity. experiment no.1: sensitivity of a.a to different concentrations of alcoholic and aqueous green tea extracts in vitro: the concentrations of alcoholic green tea extract used in this experiment were: (10%,20%,30%,40%,50%,60%,70%,80%,90%,10 0%). the concentrations of aqueous green tea extract used in this experiment were: (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%). chx gluconate (0.2%) was used in this experiment as a positive control d.w (distilled water) was used in this experiment as a negative control. agar well diffusion method was used, using a sterile loop, three colonies were picked up and spread on blood agar plate in a mattress fashion, then wells of equal size and depth will be prepared in the agar using pasteur pipette under aseptic conditions, afterwards each well was filled with the selected agent(100 microliter) then the plates were incubated anaerobically for 48 hours. inhibition zone represents the clear zone across the diameter of each well where no bacterial growth is present. the inhibition zones were measured in millimeters using a ruler. experiment no.2: determination of mic (minimum inhibitory concentration) and mbc (minimum j bagh college dentistry vol. 27(3), september 2015 antibacterial effects oral and maxillofacial surgery and periodontics 104 bactericidal concentration) of alcoholic and aqueous green tea extracts against a.a: first serial dilution method was performed in order to standardize the bacterial inoculums. appendroff tubes were labeled and arranged in a rack, 100 µl of bacterial suspension (103 concentration) were added to each tube then 50ul of the tested agent were added to its designated tube. then the tubes were incubated anaerobically for 72 hours. after 72 hours the tubes were examined to see if there was any turbidity (turbidity indicates bacterial growth), the tubes that showed signs of turbidity were excluded while the tubes that lack turbidity were identified as the minimum inhibitory concentration. c-determination of mbc: the tubes that were identified as the mic were then subcultured in order to determine the mbc,150µl were taken from each tube using a micropipette and then spread on a blood agar plate using a sterile spreader and incubated anaerobically for 48 hours. after 48 hours the plates were taken out and examined to see if there was any bacterial growth, the plates that showed no growth were identified as minimum bactericidal concentration. experiment no.3: hplc determination of green tea extracts (aqueous and alcoholic): both extracts were analyzed by hplc. the samples were dissolved in water and ethanol and compared with standard figure, the analysis performed on shimadzu (koyota,japan) binary system hplc lc-10a equipped with shimadzu lc 10a uv spectrophotometer. the active compounds of green tea extracts were separated on flc (fast liquid chromatographic) column (c 18), 3um particle size (50x4.6 mm i.d) supelco cn column, mobile phase were: 0.1% acetic acid in deionized water: acetonitrile 80:20 v/v. detection uv set at 280 nm, flow rate 1.2 ml/min. to calculate concentration of each constituent of water and alcohol extract this formula was used: concentration of sample µg /ml= area of sample/ area of standard x concentration of standard x dilution factor. concentration of standard=25 mg/ml. dilution factor= 4 times. results the means of inhibition zones of the different concentrations of alcoholic and aqueous extracts are presented in figure (3.16) it clearly shows that alcoholic extract showed higher inhibition zones than aqueous extract in all concentrations. table 1: descriptive statistics of inhibition zone (mm.) on aa bacteria using different types and concentrations of green tea extract and +ve and –ve control and their difference conc. inhibition zone with alcoholic extract of green tea with +ve and –ve control inhibition zone with aqueous extract of green tea with +ve and –ve control difference (d.f.=28) mean s.d. min. max. mean s.d. min. max. t-test p-value 10% 8.07 0.26 8 9 6.33 1.05 5 8 6.228 0.000 (hs) 20% 8.40 0.51 8 9 7.67 0.62 7 9 3.556 0.001 (hs) 30% 10.40 1.18 8 12 10.27 0.96 9 12 0.339 0.737 (ns) 40% 13.73 0.96 12 15 12.33 1.45 10 15 3.121 0.004 (hs) 50% 15.27 0.46 15 16 13.60 1.35 12 16 4.521 0.000 (hs) 60% 15.73 0.46 15 16 14.33 1.05 13 16 4.747 0.000 (hs) 70% 18.40 0.51 18 19 15.07 1.28 14 17 9.378 0.000 (hs) 80% 19.53 0.52 19 20 16.33 1.63 13 18 7.236 0.000 (hs) 90% 20.47 0.52 20 21 17.53 0.74 16 19 12.553 0.000 (hs) 100% 20.47 0.52 20 21 17.60 0.63 17 19 13.598 0.000 (hs) chx 19.07 0.70 18 20 19.13 0.74 18 20 -0.252 0.803 (ns) d.w. 0 0 0 0 0 0 0 0 j bagh college dentistry vol. 27(3), september 2015 antibacterial effects oral and maxillofacial surgery and periodontics 105 figure 1: mean values of inhibition zones of alcoholic and aqueous extracts with +ve and –ve controls against a.a table 2: lsd test after anova test alcoholic extract of green tea with +ve and –ve control aqueous extract of green tea with +ve and –ve control mean difference p-value mean difference p-value 10% 20% -0.333 0.143 (ns) -1.333 0.001 (hs) 30% -2.333 0.000 (hs) -3.933 0.000 (hs) 40% -5.667 0.000 (hs) -6.000 0.000 (hs) 50% -7.200 0.000 (hs) -7.267 0.000 (hs) 60% -7.667 0.000 (hs) -8.000 0.000 (hs) 70% -10.333 0.000 (hs) -8.733 0.000 (hs) 80% -11.467 0.000 (hs) -10.000 0.000 (hs) 90% -12.400 0.000 (hs) -11.200 0.000 (hs) 100% -12.400 0.000 (hs) -11.267 0.000 (hs) chx -11.000 0.000 (hs) -12.800 0.000 (hs) d.w. 8.067 0.000 (hs) 6.333 0.000 (hs) 20% 30% -2.000 0.000 (hs) -2.600 0.000 (hs) 40% -5.333 0.000 (hs) -4.667 0.000 (hs) 50% -6.867 0.000 (hs) -5.933 0.000 (hs) 60% -7.333 0.000 (hs) -6.667 0.000 (hs) 70% -10.000 0.000 (hs) -7.400 0.000 (hs) 80% -11.133 0.000 (hs) -8.667 0.000 (hs) 90% -12.067 0.000 (hs) -9.867 0.000 (hs) 100% -12.067 0.000 (hs) -9.933 0.000 (hs) chx -10.667 0.000 (hs) -11.467 0.000 (hs) d.w. 8.400 0.000 (hs) 7.667 0.000 (hs) 30% 40% -3.333 0.000 (hs) -2.067 0.000 (hs) 50% -4.867 0.000 (hs) -3.333 0.000 (hs) 60% -5.333 0.000 (hs) -4.067 0.000 (hs) 70% -8.000 0.000 (hs) -4.800 0.000 (hs) 80% -9.133 0.000 (hs) -6.067 0.000 (hs) 90% -10.067 0.000 (hs) -7.267 0.000 (hs) 100% -10.067 0.000 (hs) -7.333 0.000 (hs) chx -8.667 0.000 (hs) -8.867 0.000 (hs) d.w. 10.400 0.000 (hs) 10.267 0.000 (hs) 40% 50% -1.533 0.000 (hs) -1.267 0.001 (hs) 60% -2.000 0.000 (hs) -2.000 0.000 (hs) 70% -4.667 0.000 (hs) -2.733 0.000 (hs) 80% -5.800 0.000 (hs) -4.000 0.000 (hs) 90% -6.733 0.000 (hs) -5.200 0.000 (hs) 100% -6.733 0.000 (hs) -5.267 0.000 (hs) chx -5.333 0.000 (hs) -6.800 0.000 (hs) d.w. 13.733 0.000 (hs) 12.333 0.000 (hs) j bagh college dentistry vol. 27(3), september 2015 antibacterial effects oral and maxillofacial surgery and periodontics 106 50% 60% -0.467 0.031 (s) -0.733 0.062 (ns) 70% -3.133 0.000 (hs) -1.467 0.000 (hs) 80% -4.267 0.000 (hs) -2.733 0.000 (hs) 90% -5.200 0.000 (hs) -3.933 0.000 (hs) 100% -5.200 0.000 (hs) -4.000 0.000 (hs) chx -3.800 0.000 (hs) -5.533 0.000 (hs) d.w. 15.267 0.000 (hs) 13.600 0.000 (hs) 60% 70% -2.667 0.000 (hs) -0.733 0.062 (ns) 80% -3.800 0.000 (hs) -2.000 0.000 (hs) 90% -4.733 0.000 (hs) -3.200 0.000 (hs) 100% -4.733 0.000 (hs) -3.267 0.000 (hs) chx -3.333 0.000 (hs) -4.800 0.000 (hs) d.w. 15.733 0.000 (hs) 14.333 0.000 (hs) 70% 80% -1.133 0.000 (hs) -1.267 0.001 (hs) 90% -2.067 0.000 (hs) -2.467 0.000 (hs) 100% -2.067 0.000 (hs) -2.533 0.000 (hs) chx -0.667 0.002 (hs) -4.067 0.000 (hs) d.w. 18.400 0.000 (hs) 15.067 0.000 (hs) 80% 90% -0.933 0.000 (hs) -1.200 0.002 (hs) 100% -0.933 0.000 (hs) -1.267 0.001 (hs) chx 0.467 0.031 (s) -2.800 0.000 (hs) d.w. 19.533 0.000 (hs) 16.333 0.000 (hs) 90% 100% 0 1 (ns) -0.067 0.865 (ns) chx 1.400 0.000 (hs) -1.600 0.000 (hs) d.w. 20.467 0.000 (hs) 17.533 0.000 (hs) 100% chx 1.400 0.000 (hs) -1.533 0.000 (hs) d.w. 20.467 0.000 (hs) 17.600 0.000 (hs) chx d.w. 19.067 0.000 (hs) 19.133 0.000 (hs) experiment no.2: determination of minimum inhibitory and minimum bactericidal concentrations of aqueous and alcoholic green tea extracts against a.a and p.g: 1-determination ofminimum inhibitory concentration (mic): the mic for alcoholic green tea extract that inhibit aggregatibacteractinomycetemcomitans growth was 60%.the mic for aqueous green tea extract that inhibits aggregatibacteractinomycetemcomitans growth was 70%. 2-determination ofminimum bactericidal concentration (mbc): the mbc for alcoholic green tea extract that kills aggregatibacteractinomycetemcomitans was 80%.the mbc for aqueous green tea extract that kills aggregatibacteractinomycetemcomitans growth was 90%. experiment no.3: hplc determination of green tea extracts (aqueous and alcoholic): table 3: descriptive data for concentration of each constituent of aqueous and alcoholic green tea extracts: subjects conc. of standard conc. of water extract/ µg conc. of alcoholic extract/ µg caffeine 25 72.19 141.63 epicatechin 25 123.73 101.15 epicatechingallate (ecg) 25 183.37 111.36 epigallocatechingallate (egcg) 25 132.13 174.96 by viewing the results of hplc analysis of both extracts, it was revealed that alcoholic extract had higher content of epigallocatechingallate (egcg) which is the main active polyphenol in green tea, while aqueous extract had higher content of epicatechin and epicatechingallate. j bagh college dentistry vol. 27(3), september 2015 antibacterial effects oral and maxillofacial surgery and periodontics 107 discussion there are four main catechins found in green tea: epicatechin (ec), epicatechin-3-gallate (ecg), epigallocatechin (egc), and epigallocatechin-3-gallate (egcg).three of these (ecg, egc and egcg) have shown to have antimicrobial effects against a variety of organisms (22). the results of studies on the antimicrobial effects of green tea have shown that the potential for preventive and therapeutic purposes is present. the search for alternative antibacterial compounds has been a major concern in recent years because some of the drugs used haveadverse effects and high cost. it was shown that herbs exhibit biochemical and pharmacological activities and can be used as mouth rinses (23), resistance also develops more slowly with natural products (24). sensitivity of aggregatibacteractinomycetemcomitans to different concentrations of green tea extracts (alcoholic and aqueous) in vitro (agar well diffusion): results showed that alcoholic and aqueous green tea extracts were able to inhibit the growth of a.a, this finding was in coincidence with other studies (25-27). the diameter of inhibition zones were increased as the concentration of both green tea extracts increased from 10% to 90%, this was in agreement with it was reported that that increasing concentration of green tea would increase the inhibition of bacterial growth and the highest concentration created the largest zone of inhibition (28). alcoholic extract 80%, 90% and 100% concentrations showed larger inhibition zones than chlorhexidine , and by using lsd test 80% conc. showed significant difference, 90% and 100% conc. showed highly significant difference which suggests that they have shown higher antimicrobial activity than chlorhexidine. this finding presents a great promise to use green tea extract as an alternative to chlorhexidine. meanwhile chlorhexidine showed larger inhibition zones than all aqueous extract concentrations. recent studies revealed that egcg exhibited strong antimicrobial abilities, the direct antimicrobial effects of green tea have been attributed to egcg and that egcg is the most abundant catechin in green tea (29). ecg and egcg strongly inhibited the cytotoxic effects of aggregatibacteractinomycetemcomitans–lipopoly saccharide on each cell (27). it was stated that initial screenings of plants for possible antimicrobial activities typically begin by using crude aqueous or alcohol extractions and can be followed by various organic extraction methods. since nearly all of the identified components from plants active against microrganisms are aromatic or saturated organic compounds, they are most often obtained through initial ethanol or methanol extraction and this may explain the greater antimicrobial activity exhibited by the alcoholic extract compared to the aqueous extract (21). high egcg concentrations irreversibly damage the bacterial cytoplasmic membrane by generating hydrogen peroxide within the bilayer or by inhibiting the cytoplasmic enzymes and type ii fatty acid 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(ivsl). 30. ikigai h, nakae t, hara y, and shimamura t. bactericidal cate chins damage the lipid bilayer. biochim. biophys. acta1147, 132–136.doi: 10.1016/0005-2736(93)90323-r 1993 31. zhang ym, rock co. evaluation of epigallocatechingallate and related plant polyphenols as inhibitors of the fab gandfabireductasesofbacterial type ii fatty-acid synthesis. j biol chem 2004; 279, 30994–31001.doi:10.1074/ jbc.m403697200. 32. navarro-martinez md, navarro-peran e, cabezasherrera j, ruiz-gomez j, garcia-canovas f and rodriguez lopez jn. antifolate activity of epigallocatechingallate against stenotrophomonasmaltophilia. antimicrob. agents chemother 2005; 49, 2914– 2920.doi:10.1128/aac.49.7.2914-2920.2005. ammar f.doc j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry130 evaluation of andrews' six keys of normal occlusion in a sample of iraqi adults in baghdad city ammar sh. al-ubaydi, b.d.s. (1) nagham m.j. almothaffar, b.d.s., m.sc. (2) abstract background: the andrews’ six keys of normal occlusion contribute individually and collectively to the total scheme of occlusion and, therefore, are viewed as essential to successful orthodontic treatment. the present research aims to evaluate the presence of the parameters of the andrews’ six keys of normal occlusion in a sample of 100 iraqi adults with complete permanent dentition and clinically acceptable normal occlusion (angle’s class i) in baghdad city. their age range 18-25 years (60 males and 40 females). materials and methods: each patient was subjected to clinical examination and then study cast models were made, with their occlusal records. the measuring tools that have been used involved: three-dimensional goniometer to measure crown angulation and inclination, interlandi template to measure tooth rotation and digital calliper to measure curve of spee. results: the results that were obtained showed that the distribution of andrews’ six key was achieved as follow: the interarch relationship (key i) which is composed of seven items was achieved in most of models (72%); the angulation (key ii) was achieved in 67%; the inclination (key iii) was showed in less than half of the sample (41%); the rotation (key iv) was achieved in 62%; the interproximal contact (key v) was achieved in 57% and the curve of spee (key vi) was achieved in all models (100%). conclusion: this study found that only 10% of the models presented with all six keys simultaneously. whereas the higher percentage (34%) was found with four keys and only one model presented with one key (1%). keywords: andrews’ six keys, normal occlusion. (j bagh coll dentistry 2013; 25(2):130-139). introduction angle in 1899 published his book "the classification of malocclusions" was an important step because he was not only identify the main types of malocclusion, but also included the first clear and simple definition of normal occlusion in its natural dentition. over time, definitions have been sought for more accurate and safer ways to identify patterns of normal occlusion(1). the six keys of normal occlusion were a system of structural interdependence and that formed the basis for the assessment of orthodontic patients, and that the failure of one or more keys indicates an inadequate occlusion. the clinical experience and observations of treatment exhibits at national meetings and elsewhere had increasingly pointed to a corollary fact-that even with respect to the molar relationship itself, the positioning of that critical mesiobuccal cusp within that specified space could be inadequate. too many models displaying that vital cuspembrasure relationship had, even after orthodontic treatment, obvious inadequacies, despite the acceptable molar relationship as described by angle(2). at first, little attention was paid to the dental occlusion, and focus was laid on the tooth alignment and correction of facial proportions. (1) msc student, department of orthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad. extractions were common to tackle dental problems, for crowding or misalignments, and the details of occlusal relationships were considered unimportant. a static evaluation of occlusion that was examined in relation to andrews’ scheme and associated with centric occlusion depended on the appropriate position of each individual tooth. for him, the six keys were quite helpful, but should include functional goals (3). since antiquity the incorrect dental position has been presented as a problem for many people, and attempts to fix it date back to at least 1000 bc. terminologically, the word "occlusion" means close up: "oc" = up, "clusion" = close. the original concept refers to an action executed, literally an anatomical approach, a description of how and when the teeth are in contact. as dentistry developed in the eighteenth and nineteenth centuries, a large number of devices for the adjustment of the teeth were described by several authors. in 1890, edward a. angle began to do research in the area of occlusion. initially he had the greatest interest in prosthesis but his growing dedication to the dental occlusion and treatment necessary to have a normal occlusion led to the development of orthodontics as a specialty, and he was then regarded as the father of modern orthodontics. although, the six keys to occlusion of andrews are now reference to the goals of treatment, most research uses the control sample of the group with normal occlusion established by the method described in 1907 by angle, which accounts for finding such low j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry131 prevalence of the six keys in occlusions classified as normal(4). andrews examined hundreds of models seeking similar characteristics among them. he reported six significant characteristics consistently observed in 120 casts of non-orthodontics adult patients (18-25 years old) with normal occlusion (2), which were: key i: molar relationship: the distal surface of the distobuccal cusp of the upper first permanent molar made contact and occluded with the mesial surface of the mesiobuccal cusp of the lower second molar. the mesiobuccal cusp of the upper first permanent molar fell within the groove between the mesial and middle cusps of the lower first permanent molar. the canines and premolars enjoyed a cusp-embrasure relationship buccally, and a cusp fossa relationship lingually. key ii: crown angulation (the mesiodistal "tip"): refers to angulation (or tip) of the long axis of the crown, not to angulation of the long axis of the entire tooth. the long axis of the crown for all teeth, except molars, is judged to be the middevelopmental ridge, which is the most prominent and centermost vertical portion of the labial or buccal surface of the crown. the long axis of the molar crown is identified by the dominant vertical groove on the buccal surface of the crown. crown tip is expressed in degrees, plus or minus. the degree of crown tip is the angle between the long axis of the crown (as viewed from the labial or buccal surface) and a line bearing 90 degrees from the occlusal plane. a "plus reading" is awarded when the gingival portion of the long axis of the crown is distal to the incisal portion. a "minus reading" is assigned when the gingival portion of the long axis of the crown is mesial to the incisal portion. key iii: crown inclination: (labiolingual or buccolingual inclination): refers to the labiolingual or buccolingual inclination of the long axis of the crown, not to the inclination of the long axis of the entire tooth. crown inclination is expressed in plus or minus degrees, representing the angle formed by a line which bears 90 degrees to the occlusal plane and a line that is tangent to the bracket site (which is in the middle of the labial or buccal long axis of the clinical crown, as viewed from the mesial or distal). a plus reading is given if the gingival portion of the tangent line (or of the crown) is lingual to the incisal portion. a minus reading is recorded when the gingival portion of the tangent line (or of the crown) is labial to the incisal portion. key iv: rotations: the fourth key to normal occlusion is that the teeth should be free of undesirable rotations. key v: spaces: the fifth key is that the contact points should be tight (no spaces). key vi: occlusal plane: the planes of occlusion found on the nonorthodontic normal models ranged from flat to slight curves of spee. materials and methods: the sample of this study was collected from the researcher private clinic and diagnosis department, college of dentistry, university of baghdad. out of 250 clinically examined iraqi adult subjects, only 100 subjects (60 male and 40 female, age range 18-25) were selected when met a special criteria, which were: 1. full set of permanent teeth (excluding the 3rd molar). 2. clinically skeletal class i determined by two finger method (5), and bilateral class i molar and canine relationships, with normal overjet and overbite (2-4 mm). 3. well-aligned arches with no supernumerary teeth and no clear rotation by visual examination. 4. normal appearing teeth, no badly carious lesion, no missing or extracted teeth. 5. no large restorations or fixed replacement. 6. no history of previous orthopaedic, orthodontic or facial trauma. 7. no gross asymmetries in the dental arches and face. • examination and clinical tools: dental mirrors, kidney dish, antiseptic solution (spirit 75%), cotton, sliding calliper to measure the overbite and overjet, impression metallic trays, alginate, dental stone and plaster of paris, sheet wax, sprit lamp, rubber bowls and spatula. • laboratory and other equipments: trimmer, separating media (vaseline™), two glass slabs (15cm × 20cm), plastic blocks (bricks) (1.5cm × 3cm), micro-motor engine with round large carbide bur, two hundred transparent plates (1mm thick), marker pen and black pencil. • measurement equipments: threedimensional goniometer (wooden type) which is a simple device constructed by the researcher and designed to measure rotation, tip and torque (rtt) for each individual tooth (figure 1, 2 and 3), plane rotation control (prc) template or the so-called ray set® template (figure 4), which is essential for preliminary analysis of the 1st order positions of the teeth (each line of template represents 2°) (6), orthodontic interlandi diagram for tooth rotation measurement (figure 5) (7), digital caliper with precision of up to 0.01 mm j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry132 for linear measurement and millimetre plastic ruler. history and clinical examination: each individual was seated on a dental chair with his / her frankfort head plane horizontal to the floor, to assess the skeletal class i relationship clinically (5). information about his / her name, age, origin, history of facial trauma and previous orthodontic treatment was taken. then intraoral examination was done for each person to check the criteria that should be present. ÿ clinical work: with metallic trays upper and lower impressions were taken by alginate, then dental occlusion was recorded by using double layer of wax (7mm) (8). ÿ laboratory work: 1. the impression was poured using dental stone. 2. after that the dental cast was removed from impression tray, and the occlusal surface of the upper arch was placed on the glass slab. 3. two plastic blocks (bricks) were placed one over the other on each corner of the glass slab, so that the height of the bricks became 2.25 cm. 4. plaster of thin consistency was mixed and then poured on the base of the upper cast. 5. the 2nd glass slab was painted with separating media, so that the isolated surface was placed over the plastic blocks and pushed until it touched them in 4 corners. by this way the excess of plaster material escaped from the sides of the cast, so that the base of the upper cast became parallel to the occlusal plane. 6. when the plaster became set the upper cast was removed from the glass slab and turned over so that the base of the cast was repositioned on the glass slab. 7. the plastic blocks were repositioned on the corner of the glass slab, and their height was increased by adding two other blocks on each of the previous blocks, so that the number of blocks on each corner became four and their height became 4.5 cm. 8. now the lower cast was positioned on the upper cast using the bite registration wax which was previously taken for each subject. 9. again the 2nd glass slab was separated with separating media, and then the plaster was mixed and poured on the base of the lower cast. after that the isolated surface of the slab was placed over the plastic blocks and pushed until it touched them on four corners and the slab was left until the plaster was set. 10. the upper and lower casts were removed from the slabs and their borders (not base) were trimmed with a fine trimmer. by this way the parallelism of upper and lower cast bases to the occlusal plane could be obtained. 11. finally, the models were enumerated. ÿ preparation of models for evaluation: now the models were evaluated to observe the presence of andrews’ six keys of occlusion according to the methodology that was described by andrews 9. the facial axis of the clinical crown and its midpoint (the facial axis point), were marked with a pencil on each crown of each dental cast. the facial axis of the clinical crown represents the most prominent portion of the central lobe on the facial surface of each crown and can be determined by measuring the mesiodistal distance for each crown then dividing it; for molars, it represents the buccal groove that separates the two large facial cusps. the facial axis point was marked as the midpoint of the facial axis of the clinical crown and can be determined by measuring the occluso-gingival distance for each crown then dividing it (figure 6). the facial axis of the clinical crown served as the reference line from which crown angulation and inclination were measured. ÿ evaluation of the models: the models were evaluated to observe the presence of all or some of the andrews’ six keys of occlusion 2 as follows: key i (interarch relationship): the occlusal relationship was evaluated from the buccal and lingual regions of the models. this key is composed of seven items as detailed below: 1st item: this item describes the position of the mesio-buccal cusp of the permanent upper 1st molar that should occlude in the groove between the mesial and middle cusp (developmental groove) of the permanent lower 1st molar, 2nd item: the second item describes the position of the distal surface of the distobuccal cusp of the upper first permanent molar made contact and occluded with the mesial surface of the mesiobuccal cusp of the lower second molar, 3rd item: this item describes the position of the mesio-lingual cusp of the upper 1st molar that should occlude in the central fossa of the lower 1st molar, 4th item: in which the buccal cusps of the upper premolars should be related to the buccal embrasure of the lower premolars, 5th item: according to the fifth topic, the lingual cusps of the upper premolars should have a cuspfossa relationship with the lower premolars, 6th item: in which the cusp of the upper canine should be related to the buccal embrasure of the lower canine and 1st premolar and the tip of its peak should be slightly mesial to the embrasure and 7th item: this item describes the incisors position as key i, in which the upper incisors should overlap the lower incisors and midline should be coincide. j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry133 key ii (crown angulation): the following procedure was done to measure crown angulation for each tooth in the upper and lower arches: 1. the ray set® template was used to read the models’ first order degree of rotation, necessary for placing the tooth at the center of the rtt base’s second and third order system of movements.6 2. the cast was transferred to the device, then it had been adjusted by the rotating base so that the measured tooth fitted on 0°, the inclination adjustable screw was loosened to enable both the cast with the rotating base of the threedimensional goniometer to move freely and by this way the tooth will inclined until the vertical rod that was fitted to the mandrel became tangent to facial axis point of the measured tooth. then the adjustable screw was tightened. 3. the angulation adjustable screw was loosened, and then the vertical rod was aligned and superimposed on the facial axis of clinical crown. after that the adjustable screw was tighted, by this way the tip value was assessed directly from the angulation measuring scale. 4. after that each tip value of the measured tooth was checked with the range of andrews’ findings (mean and standard deviation); if the tip value within the range of andrews’ findings, it would considered as satisfactory (s), but if not it was considered non-satisfactory (n) (4) . key iii (crown inclination): 1. to measure the toque value, the inclination adjustable screw was loosened and then the base in the 3rd order plane was tilted until the vertical rod (mandrel) and the laser beam were tangent to facial axis point. then the adjustable torque screw was tightened. 2. the torque pointer was observed to read the value directly from the inclination measuring scale. 3. after that each torque value of the measured tooth was checked with the range of andrews’ findings (mean and standard deviation). key iv (rotation): the rotation was determined by the following way: 1. a transparent acrylic plate was placed on the occlusal plane of the model. 2. the transparent acrylic plate in the canine region was perforated to prevent its displacement during tracing. 3. a fine marker pen was used to draw up a line that connected the contact points and buccal contour of the crowns. 4. after that the transparent acrylic plate was placed on the orthodontic diagram of interlandi to draw the ideal arc for each model and accurately check out the angle of each crown. key v (tight contact points): the existence of space between teeth was evaluated at the mesiodistal surfaces of the buccal side of the models. key vi (curve of spee): the planes of occlusion found on the non-orthodontic normal models ranged from flat to slight curve of spee. the occlusal plane that was greater than 2.5 mm was considered undesirable (2). this was measured as follows: 1. a hard plastic plate was placed flat over the occlusal surfaces of the mandibular posterior teeth. usually the template touched only the incisal edges of the mandibular incisors and the distal cusps of the permanent second molars. 2. a digital caliper was used to measure on each side, the depth of the curve of spee was determined by measuring, in millimetres, the distance from the side of the template facing the teeth to the buccal cusp tip farthest away from it (2). the mean of the values obtained for the right and left sides was recorded as the depth of curve of spee. ÿ statistical analysis: the data were analysed by using (analyse-it version 2.20 excel 12+). the usual statistical methods were used in order to analyze and assess results; they include: descriptive statistics: mean value, standard deviation (s.d), frequency distribution and percentage of andrews’ six keys. inferential statistics: t-test and pearson’s chisquare. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 * significant 0.01 ≥ p > 0.001** highly significant p ≤ 0.001 *** very highly significant results and discussion based on the study of 120 non-orthodontic normal adults, andrews’s fully programmed appliance was developed. the prescription built into his appliance was based on the 1964 sample. the six keys of normal occlusion, which were used as the fundamental guidelines for determining the standard bracket prescription, were evaluated and calculated. even after completing his study of 120 non-orthodontic normal casts, andrews did not stop his search for better casts. in fact, to this day, the search for superior casts has continued. in 1988, the new norms for average angulation and inclination were published based on the best of 120 casts to that date (2 , 9). this study has dealt with the distribution of andrews’ six keys of normal occlusion in iraqi population. the sample selected in this study was composed of young adults, 18 – 25 years of age, because most of the j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry134 growth of facial area could be considered to be complete after the age of 18 year (10). two methods have been found for the comparison between the obtained values from this study and andrews’ findings. one of them was based on the study of brangeli (4), who conducted the satisfactory and non-satisfactory evaluation which was tend to be more subjective. while the other method was based on sebata (11), watanabe (12), currim and wadkar (13) studies, which was more informative for the comparison between the study results and andrews’ (9) findings since it depends on a statistical method. in this study we have found that 10% of the models meet all the occlusion findings of andrews’ six keys of normal occlusion, 5 keys (21%), 4 keys (34%), 3 keys (26%), 2 keys (8%) and finally 1 key (1%). this result does not agree with the work of brangeli (4), who also used the six keys of andrews as a reference for evaluation of normal occlusion. however, using a selected sample according to the classification of angle (1), brangeli (4) has found that the presence of 6 keys was zero, 5 keys (10%), 4 keys (15%), 3 keys (23%), 2 keys (34%) and 1 key (7%), whereas (11%) had none of the keys. when we compare between our study and brangeli , we see that there is great difference. in our study great numbers of keys were achieved; because the samples of brangeli may be not carefully selected due to limited time in his study, as he stated, and this led to found less satisfactory results in his study. it had been found that the higher percentage of males 20.4%, females 13.6% and total sample 34% were achieved 4 keys from andrews’ six keys of normal occlusion. again, significant difference had been not detected between males and females concerning the distribution of andrews’ six keys and the number of keys that have been achieved (table 1 & 2). 1key i (interarch relationship): this key was satisfactory in 72% of total sample; of which 45% were males and 27% females. in contrast, brangeli (4) found this key was satisfactory in 66% of his study sample. this study has found that the 1st and 7th items were satisfactory in all samples (100%) and this was perhaps because these items had been seen early and easily during sample selection, followed by 3rd item forming (95%), then 6th item (87%), after that 4th item (84%), then 2nd item (74%) and finally 5th item (63%). in our study the intercuspation of premolars and canines were the most problem area, this may be due to crown inclination of the central incisors and canines in upper & lower arch which were inclined more labially and buccally than andrews’ average (9). 2key ii (crown angulation): this key was satisfactory in 67% of total sample ( 41% males and 26% females), while brangeli mentioned that this key was satisfactory in 43% of his sample. on comparison of andrews’ original data, andrews’ data of 1988, sebata’s, watanabe’s, currim’s and wadkar’s data, with this maxillary angulation readings, we can conclude that our readings for the central incisor are in closest agreement with watanbe’s. our readings for the lateral incisor and the 1st premolar best match with andrews’; the canine and 2nd molar readings are much less comparable to all previous data, while the readings for 2nd premolar and 1st molar are nearest to currim’s and wadkar’s. on comparison of andrews’ original data, andrews’ data of 1988, sebata’s, watanabe’s, currim’s and wadkar’s data, with our mandibular angulation readings, we can conclude that our readings for the central incisor are in closest agreement with sebata’s. the readings for the lateral incisor best match with currim’s and wadkar’s; the canine and the 2nd molar readings are much less comparable to all previous data, while the readings for 2nd premolar are nearest to andrews’, currim’s and wadkar’s. finally, the 1st premolar and 1st molar readings are in closest agreement with andrews’(table 5) . these findings suggest the possibility of a distinct racial and ethnic trait difference. to obtain excellent finishing, changes in the archwire, with extra treatment built in, might thus become routine procedure. although the readings of p-value had shown different significant levels for the upper (lateral incisor, 2nd premolar and 1st molar), lower (central and lateral incisors, 2nd premolar and 1st molar); but the difference in mean angulation values for these teeth were not more than 1° when it compared with andrews values (1988). only the canine and second molar (upper and lower) had readings that differed by 2° or more. this would indicate that, if bracket prescriptions were to be altered, keeping in mind only the ideal values for the population in question, the prescription for the canine and 2nd molar should be altered to suit the iraqi population. similar suggestion also reported in the study of currim and wadkar (13). in this study it has been found that there is no significant difference in crown angulation between males and females, except for the upper canine (less angulated in females than males) and second molar (less angulated distally in males than females) (table 3). j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry135 3key iii (crown inclination): this key was achieved in 41% of total sample (28% males and 13% females). this key was satisfactory in 37% in the study of brangeli (4). on comparison of andrews’ original data, andrews’ data of 1988, sebata’s, watanabe’s, currim’s and wadkar’s data, with our maxillary inclination readings, we can conclude that our readings for the central incisor, 1st and 2nd molars are in closest agreement with andrews’. the lateral incisor, canine, 1st and 2nd premolar readings are much less comparable to all previous data (table 5). when the obtained values compared with andrews’ initial data (9), it had been found that the central and lateral incisors in the present study are more inclined, the canines and premolars are more upright, the first and second molars readings are comparable. this suggests a need for alterations in the archwire or bracket prescription for all teeth except the first and second molar. on comparison of andrews’ original data, andrews’ data of 1988, sebata’s, watanabe’s, currim’s and wadkar’s data, with our mandibular inclination readings, it could be conclude that our readings for the central incisor and 1st premolar are much less comparable to all previous data. the lateral incisor and canine readings are in closest agreement with sebata’s. our readings for the 2nd premolar, 1st and 2nd molars are best match with currim’s and wadkar’s. in the mandibular arch, all teeth in our sample were more upright than those in andrews’ 1988 sample and his original study group of 1964, except for central and lateral incisors which had positive values. this finding again supports all earlier observations that indicate possible racial and ethnic factors contributing to the difference in readings. changes in the archwire or the bracket prescription based on normal values are again called for. in this study it has been found that there is no significant difference in crown inclination between males and females, except for the lower canine (more upright in males than females) (table 4). this key was achieved by the lowest percentage in the sample (table 2); this may be related to the fact that the iraqi samples of our study were different racially than andrews’ american individuals. yet, this study has found that iraqi people had higher proclination in the upper and lower anterior teeth. finally, according to method of brangeli 4, it has been found that some values of key ii and iii within the normal range of andrews (satisfactory), but this method was more subjective. therefore, to be more precise in this study a statistical comparison had been employed (sebata, (11); watanabe, (12); currim and wadkar (13)), to evaluate the values of angulation and inclination with andrews’ findings. it had been found that there were significant differences between them with different levels of p-value shown in table 5. 4key iv (rotation): we cannot underestimate in any way the importance of no tooth rotation that provides the establishment of good occlusion. however, the value considered normal by andrews 2 is very limited (2°). this value is different from those described by björk et al 14 and cochrane et al (15), who considered (15°) as an acceptable value. in this study it had been found that the occurrence of tooth rotation more than 2° in the upper arch (41%) is less than in the lower arch (59%). the most affected tooth is the lower second premolar. this may be due to late time of eruption. this key showed that there was no significant difference between males and females (table 6). this key was satisfactory in 62% of total sample, 41% were males and 21% females (table 2). in the sample of brangeli (4), the rotation did not meet andrews’ findings (i.e. not satisfactory). 5key v (contact point): in this study it has been found that the occurrence of open contact point in the upper arch (73%) is more than in the lower arch (27%), and the most affected tooth is the upper canine. this may be due to tooth size discrepancy (small lateral incisors), and arch size discrepancy. there was no significant difference between males and females as shown in table 7. this key was satisfactory in 57% of total sample, in which 35% were males and 22% females (table 2). low values (10%) of tight contact point were only found by brangeli (4). in this study it was found that there were no crowding, but small spacing existed. this is probably due to presence of small buccal inclination or mild rotations. j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry136 table 1: comparison between males and females according to the number of achieved keys sex group 6 keys 5 keys 4 keys 3 keys 2 keys 1 key total males 4 15 25 11 5 0 60 (6.0%) (12.6%) (20.4%) (15.6%) (4.8%) (0.6%) females 6 6 9 15 3 1 40 (4.0%) (8.4%) (13.6%) (10.4%) (3.2%) (0.4%) total 10 21 34 26 8 1 100 chi-square 10.31 p-value 0.0668 (ns) table 2: comparison of andrews’ six keys of normal occlusion in males and females sex group key i key ii key iii key iv key v key vi total males 45 41 28 41 30 60 245 (44.2%) (41.1%) (25.2%) (38.1%) (35.0%) (61.4%) females 27 26 13 21 27 40 154 (27.8%) (25.9%) (15.8%) (23.9%) (22.0%) (38.6%) total 72 67 41 62 57 100 399 chi-square 3.38 p-value 0.6421 (ns) table 3: comparison of crown angulation between males and females tooth no. teeth angulation upper arch lower arch sex mean s.d. t-test p-value mean s.d. t-test p-value 1 male 3.1 2.09 0.42 0.67 -0.45 1.5 0.49 0.62 female 2.9 2.7 -0.61 1.86 2 male 7.21 2.4 0.76 0.44 -0.5 2.81 -1.17 0.24 female 6.83 2.37 0.11 2.21 3 male 4.8 2.94 2.35 0.02* 0.45 2.91 0.95 0.34 female 3.26 3.56 -0.15 3.25 4 male 2.76 2.42 0.11 0.91 1.41 2.16 1.36 0.17 female 2.71 2.45 0.75 2.69 5 male 4.41 2.77 0.82 0.41 2.11 2.13 0.49 0.62 female 3.95 2.69 1.9 2.13 6 male 4.49 2.64 0.29 0.77 2.76 2.31 0.86 0.39 female 4.35 2.19 2.38 2.04 7 male -1.85 2.95 2.04 0.04* 5.04 2.48 0.57 0.57 female -3.24 3.86 4.75 2.46 according to andrews (2) it is possible, of course, to visualize and to find models which have deficiencies, such as the need for caps to provide proper contact, but these are dental problems not orthodontic ones. sometimes there are compromises to be weighed, and these pose the true challenge to the professional judgment of the orthodontist. as responsible specialists, we are here to attempt to achieve the maximum possible benefit for our patients. 6key vi (curve of spee): the curve of spee in the present sample averaged 1.36 mm which is within the acceptable range of 0 to 2.5 mm set by andrews. this key was achieved in all samples (100%) with no significant difference between males and females as shown in table 8, while brangeli 4 found that this key was satisfactory in 74%. this agrees with orthlieb (16) who found no statistically significant difference in the radius of the curve of spee between a males and females sample. ferrario et al (17) reported that the occlusal curvature of the mandibular arch is not significantly influenced by sex. braun and schmidt (18) studied the differences in the curve of spee between men and women and between the different angle classifications,he found that the shape of the curve for males and females seemed to be identical, and no significant differences could be found among class i, class ii division 1, or class ii division 2 patients. j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry137 table 4: comparison of crown inclination between males and females tooth no teeth inclination upper arch lower arch sex mean s.d. t-test p-value mean s.d. t-test p-value 1 male 7.49 3.92 -0.72 0.47 4.85 5.97 -1.57 0.12 female 8.26 6.71 6.62 4.82 2 male 5.92 3.95 -0.16 0.87 2.4 4.6 0.91 0.36 female 6.08 6.34 1.52 5.01 3 male -3.09 4.8 -0.12 0.90 -4.69 4.26 2.03 0.04* female -2.98 3.97 -6.57 4.9 4 male -3.46 5.47 0.85 0.39 -13.19 5.5 0.43 0.66 female -4.46 6.08 -13.65 4.81 5 male -5.27 4.73 -0.17 0.86 -18.33 5.48 0.01 0.99 female -5.1 5.01 18.34 6.17 6 male -11.61 4.28 -1.13 0.26 -27.59 6.02 -0.14 0.88 female -10.67 3.78 -27.35 10.76 7 male -8.32 3.97 -1.29 0.19 -33.25 6.99 1.28 0.20 female -7.21 4.59 -34.92 5.36 table 5: different angulations and inclination values of several authors. author andrews 1989 sebata 1980 watanable 2001 currim wadkar 2004 present study andrews 1989 sebata 1980 watanable 2001 currim & wadkar 2004 present study no. of sample 120 41 80 68 100 120 41 80 68 100 location usa japan japan india iraq usa japan japan india iraq angulation tooth no. upper arch lower arch mean value mean value 1 3.59 4.25 3.11 3.3 3.02 0.53 -0.48 1.98 -0.23 -0.52 2 8.04 5.74 3.99 4.27 7.06 0.38 -1.2 2.28 -0.43 -0.25 3 8.4 7.74 7.73 2.66 4.19 2.48 1.48 5.4 -1.17 0.21 4 2.65 3.51 4.67 2.6 2.74 1.28 2.52 3.8 -0.32 1.14 5 2.82 6.18 5.2 5.07 4.22 1.54 6.7 3.91 1.54 2.02 6 5.73 5.22 4.94 4.53 4.44 2.03 5.74 3.7 1.67 2.61 7 0.39 -0.3 4.09 3 -2.41 2.94 7.34 3.88 2.12 4.92 inclination 1 6.11 9.42 12.82 5.8 7.8 -1.71 3.55 0.71 1.36 5.56 2 4.42 7.48 10.35 4.44 5.98 -3.24 1.66 0.53 0.88 2.05 3 -7.25 0.67 -5.29 -5.99 -3.04 -12.73 -4.73 -11.13 -8.2 -5.44 4 -8.47 -6.46 -6 -8.4 -3.86 -18.95 -14.80 -18.38 -14.6 -13.38 5 -8.78 -6.46 -7.18 -9.88 -5.21 -23.63 -22.57 -21.81 -18.5 -18.33 6 -11.53 -1.73 -9.75 -11.27 -11.24 -30.67 -26.17 -31.23 -27.47 -28.14 7 -8.01 -2.97 -9.55 -9.95 -7.88 -36.03 -31.03 -32.9 -33.63 -33.92 table 6: comparison between satisfactory and nonsatisfactory key iv in both gender sex group total chi-square p-value sig* s n male 41 19 60 2.55 0.1100 ns (37.2%) (22.8%) female 21 19 40 (24.8%) (15.2%) total 62 38 100 s = satisfactory n = non satisfactory j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry138 table 7: comparison of key v in males, females and total sample sex group total chi-square p-value sig* s n male 30 30 60 3.00 0.0833 ns (34.2%) (25.8%) female 27 13 40 (22.8%) (17.2%) total 57 43 100 s = satisfactory n = non satisfactory table 8: comparison between the mean difference of key vi for males and females sex mean s.d. min. max. male 1.31 0.4 0.5 2.5 female 1.43 0.45 0.8 2.1 t-test -1.35 p 0.1804 (ns) figure 1: frontal view, figure 2: superior view and figure 3: lateral view of three-dimensional goniometer (wooden type). figure 4: plane rotation control (prc) template or the so-called ray set® template. figure 5: orthodontic interlandi diagram for tooth rotation measurement. 7 figure 6: tracing the facial axis of the clinical crown and determining the facial axis point in the upper anterior and posterior region of the model. j bagh college dentistry vol. 25(2), june 2013 evaluation of andrews' orthodontics, pedodontics and preventive dentistry139 references 1. angle eh. classification of malocclusion. dental cosmos1899; 4: 248-264. 2. andrews lf. the six keys to normal occlusion. am j orthod dentofacial orthop1972; 62(3): 296-309. 3. roth rh. functional occlusion for the orthodontist: part 1. j clin orthod 1981a; 15: 32-51. 4. brangeli lam. prevalence of the andrews’ six keys of occlusion in young brazilians with normal occlusion. rev apcd 2001; 55(6):41145. 5. foster td. a text book of orthodontics 2nd ed. london: blackell scientific puplication; 1985. 6. melsen b, biaggini p. the ray set: a new technique for precise indirect bonding. j clin orthod 2002; 36(11):648-54. 7. interlandi s. orthodontics: bases for beginners. 4th ed. são paulo: artes médicas 1999; 149-99, 263-83. 8. moraes c. study models: indispensable element of diagnosis and restorative treatment plan in the specialties. rev apcd 1969; 23(1): 1-8. 9. andrews lf. straight wire: the concept and appliance. san diego, calif: la wells co; 1989:25– 33. 10. graber tm. orthodontics principles and practice. 3rd ed. philadelphia: w.b.saunders company; 1972. p. 48. 11. sebata e. an orthodontic study of teeth and dental arch form on the japanese normal occlusions. shikwa gakuho 1980; 80:11–35. 12. watanabe k, koga m. a morphometric study with setup models for bracket design. angle orthod 2001; 71(6):499–511. 13. currim s, wadkar pv. objective assessment of occlusal and coronal characteristics of untreated normals. am j ortho 2004; 125(5): 582-588. 14. bjork a, krebs aa, solow b. a method for epidemiological registration of malocclusion. ac odontol scand 1964; 22: 27-41. 15. cochrane sm, cunningham sj, hunt np. a comparison of the perception of facial profile by the general public and 3 groups of clinicians. j adult orthod orthognath surg. 1999; 14(4): 291-5. 16. orthlieb jd. the curve of spee: understanding the sagittal organization of mandibular teeth. cranio 1997; 15: 333-340. 17. ferrario vf, sforza c, poggio, ce, serrao g, colombo a. threedimensional dental arch curvature in human adolescents and adults. am j orthod dentofac orthop. 1999; 115: 401-405. 18. braun ml, schmidt wg. a cephalometric appraisal of the curve of spee in class i and class ii, division 1 occlusions for males and females. am j orthod 1956; 42: 255-278. 10. abdul-razzaq f.doc j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 56 immunohistochemical expression of fas/fasligand and cmyc in oral lichen planus abdul-razzaq a.m. wahhab, b.d.s (1) riyadh o. alkaisi, b.d.s., m.sc., ph.d. (2) abstarct background: oral lichen planus is a chronic inflammatory mucosal disease, presenting in various clinical forms .both antigen-specific and non-specific mechanisms involved in the pathogenesis of olp. apoptosis or programmed-cell death is a physiological process essential for the normal development and maintenance of homeostasis in many organisms. fas is a cell-surface glycoprotein, 40-kda, that belongs to the nerve growth factor / tumor necrosis factor (tnf) receptor family. fas is expressed in several tissues including blood, where its expression is upregulated on activated t and b lymphocytes and natural killer cells. fas ligand is a type ii transmembrane protein that belongs to the tumor necrosis factor family. the proto-oncogene c-myc is a transcripation factor with roles in cellular proliferation, differentiation, apoptosis and cell cycle progression. mutation in the c-myc gene and protein overexpression has been associated with a variety of hematopoietic tumors, leukemias and lymphomas. apoptosis is the mechanism that would be dysregulated in this disease. this study was conducted to evaluate the expression of fas, fasl and c-myc in oral lichen planus and to correlate the expression of either markers with each other. materials and methods: this study was performed on thirty formalinfixed paraffin-embedded tissue blocks of oral lichen planus pro and retrospectively. an immunohistochemical staining was done by using monoclonal antibodies for fas, fasl and c-myc. results: expressions of fas, fasl and c-myc were highly detected in keratinocytes and inflammatory cells of olp cases compared to negative expression in normal oral mucosa. significant correlation has been found between expression of fas, fasl and c-myc in epithelial cells with that of inflammatory cells in oral lichen planus studied cases. significant correlation has been found among expressions of fas, fasl and c-myc in epithelial cells of oral lichen planus cases. significant positive correlation found between expressions of fas, fasl and c-myc in keratinocytes and inflammatory cells of oral lichen planus . conclusion: increased expression level of fas, fasl and c-myc in both keratinocytes and lymphocytes of olp cases in comparison to normal mucosa with highly significant correlation among the markers expression indicate their important role in malignant transformation of oral lichen planus. key words: oral lichen planus tissue blocks,fas,fasl and c-myc tumor markers. (j bagh coll dentistry 2013; 25(1):5662). introduction oral lichen planus is a relatively common chronic inflammatory disease of oral mucosa with a prevalence rate of 0.5% and 2.2% of the population. clinically, olp may assume a variety of morphological changes. the most prevalent type is the reticular form characterized with interlacing white lines that are usually bilaterally distributed on the buccal mucosa and sometimes on the tongue. other types of olp are papular, plaque-like, atrophic, erosive and bullous forms. olp typically affects middle-aged or elderly women, although it can be detected also in younger men, but rarely in children (1). associations of olp with simultaneous presence of lichen lesions in the skin and genital mucosa have been recorded (1). however the etiology of olp is still unknown. the previous studies support the view that cellmediated mechanisms are involved in the initiation and the progression of the disease. also, localized autoimmunity has been suggested as playing a role in the pathogenesis of olp. (1) m.sc. student, department of oral diagnosis. college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. therefore, lacking a known causative factor means there is no specific treatment for olp (2). the histopathological of olp is characterized by a band-like lymphocytic infiltrate in juxtaepithelial lamina propria. in addition, there is hyperkeratinization, acanthosis, liquefaction degeneration of the basal cells, colloid bodies, saw-tooth appearance of rete pegs and distribution of the epithelial basement membrane (bm). despite these wellcharacterized histological features of olp, interand intra-observer reproducibility to diagnose olp is modest (3). despite the who definition of olp as a precancerous condition, the premalignant potential of olp is still debatable. malignant transformation has been estimated to occur in 0.5 – 2.9% of the olp patients. currently, there are no prognostic markers to identify which chronic olp lesions are at a higher risk for progression. thus, every olp patient should be monitored carefully to detect early cancer development (4). to understand the etiopathogenesis of olp, it is important to identify the key molecules in this disease. in the present series of studies, molecular markers for cell proliferation, apoptosis, adhesion and inflammatory cell infiltrates have been j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 57 studied to characterize the molecular phenotypes of olp more closely and to estimate their progression toward malignancy (3). fas is a member of tumour necrosis factor (tnf) receptor family that is constitutively expressed by a wide range of normal tissues including the breast (5). following cross-linking of fas by its natural ligand , a death signal is generated that catalyses cleavage of the caspase cascade of cysteine proteases, leading to apoptosis (6). fasl belong to the tnf family of membrane and secreted proteins (7). fasl expression was first thought to be restricted to the immune system, including activated t and b-lymphocytes and nk cells (8), but has now also been described in sites of immune privilege, such as the eye, testis, uterus and placenta (9). c-myc is a transcription factor with roles in cellular proliferation, transformation and implicated in the induction of programmed cell death (apoptosis) with aberrant expression of this gene has been linked to the development and progression of olp , mutations in the gene and protein over –expression have been associated with a variety of hematopoietic tumors, leukemias and lymphomas. the c-myc gene is transcribed to three major transcripts that start from different initiating sites, yielding three major proteins named c-myc1, cmyc2 and c-mycs (10). c-myc2 is an approximately 62-kda protein that is the major form of the three c-myc proteins and the one referred to as c-myc in most studies. materials and methods the samples this study was performed on thirty formalin fixed paraffin-embedded tissue blocks histologically diagnosed as olp. eighteen cases of them were prospectively collected during the year 2010 to 2011 from the histopathological laboratory in surgical specialties hospital (ssh) and archives of oral pathology laboratory of college of dentistry, baghdad university. twelve cases were retrospectively collected randomly from years 2004 till 2009 from the archives of oral pathology laboratory of college of dentistry, baghdad university during eight months period of collection for all cases. the diagnosis of each case was confirmed by examing the h&e section by two pathologists. the clinicopathological information regarding age, gender, lesion sites, clinical presentation, lesion size in addition to any other information were obtained from the case sheets presented with the specimens. control samples a. normal tissue control: five samples of normal oral mucosa were obtained from patients needed surgical removal of impacted teeth, then fixed in 10% formalin and finally processed as the test sample. b. positive tissue control: a positive tissue control is a specimen shown by previous works and according to the manufacture data sheets to stain specifically the target antigen after exposure to primary antibody. the positive tissues control in this study were: *colon tissue sections used as positive control for fas,fasl and c-myc. c .negative tissue control: these were prepared by adding pbs to the slides instead of the primary antibodies to any section of the test groups. tissue preparation and staining a .samples: all tissue specimens, samples and controls, were fixed in 10% neutral formalin and processed in a routine paraffin blocks. b. sectioning: each formalin-fixed paraffinembedded tissue block had serial sections were prepared as follows: 1. 4µm thickness sections were mounted on clean glass slides for routine haematoxylin and eosin staining (h&e), from each block of the studied sample and the control group for histopathological re-examination. 2. other 3 sections of 4µm thickness were mounted on positively charged microscopic slides (esco, superfrost plus/usa) to obtain a greater tissue adherence for immunohistochemistry. equipments and materials used under this category were: • disposable knives (sigma/germany). • microtme (leittz/germany). • ordinary glass slides (sail brand/china). • positively charged microscope slides (esco,superfrost plus/usa). • water bath(memmert/germany). • cover slips. immunohistochemistry materials and equipments: monoclonal antibodies: the detailed information and specification of the monoclonal antibodies employed in the study were shown in ( appendix i &ii&iii) . detection system usbiologicl anti mouse hrp/dab immunohistochemical detection kit (catalog no. ab64259) was used. this kit is compatible with mouse igg primary antibodies. a biotinylated, cross absorbed, and affinity purified secondary anti-mouse igg is used to detect primary antibody j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 58 –antigen complexes adhered to glass slides. (appendix iiii). reagents within the kit include: 1. normal serum 2. biotin 3. solution a&b. 4. dab chromogen (0.5 ml) 5. dab substrate (15 ml) materials and reagents used but not supplied with the kit: xelene gcc (uk) • absoulte ethanol scharlan (european union). • distelled water • mountaing medium dpx.(qualikems) • mayer's hemotoxylin. instruments& equipments: v positively charged microscopic slides (esco,superfrost plus/usa) v micropipette 0.200 µl and tips (gilson/ france). v micropipette 1000 µl and tips (salmed/germany). v eppendrof tubes (100-500 µl) . v cover slips (marienfeld/germany). v *thermometer and timer. v *washing bottles. v *graduated cylinders. v *glass staining jars. v slides holders. v *sensitive balance. v absorbent wipes. v *gloves. v hot air oven (memmert/germany). v incubator (memmert/germany). v filter paper. v litmus paper. v centrifuge (heidolph/germany). v electric light microscope. prepapartion of reagents: dilution of primary antibodies: dilution of antibodies was done by using sterile pbs in a concentration according to each data sheet of monoclonal antibodies. each antibody was tested with several runs as a technical control staining in order to reach the optimum positive run. fas/fasl and c-mycwere diluted into1/40 concentration for monoclonal antibodies. dilution of dab solution: dab was prepared by mixing 1ml of (dab buffer) with 20µl of (dab chromogen) in a tube, and then kept in a dark place until used. principles of the test the labeled streptavidin-biotin (lsab) method utilizes a biotinylated secondary antibody that links primary antibodies to astreptavidin peroxidase conjugate, and by adding the chromogen substrate, a colorimetric reaction will form at the antigen binding site. in this method a single primary antibody subsequently is associated with multiple peroxidase molecules, and because of the large enzyme-to antibody ratio, a considerable increase in sensitivity is achieved compared to direct peroxidaseconjugate methods. dab (3'-diaminobenzidine tetrahydrocloride) substrate offers the greatest sensitivity in the horse-radish peroxidase enzyme system as a colorimetric chromogen; a brown precipitate will form at the antigen-binding site. (burmesteretal., 2003 ). immunohistochemical staining procedure (manufacturer's data sheet) for detection of fas,fasl and c-myc: the procedure of the ihc assay adapted by this study was carried out in accordance with the manufacturer instructions (us biological). 1. slide backing: the slides were placed in avertical position in the hot air oven at 60ºc. over night. 2. deparaffinization and rehydration: the slides were sequentially immersed in the following solutions:. -twice in xylene for 15 minutes each. -twice in absolute ethanol for 5 minutes each. -95%ethanol for 5 minutes. -70% ethanol for 5 minute -distilled water for 5 minutes. -hydrogen perioxide for 30 minutes. -distilled water for 5minutes. -pbs for 5 minutes. 3. enough drops of normal serum were added to slides and incubated in humid chamber at 37ºc for 30 minutes, then socked 2 times one in distilled water and the other one in pbs(5minutes for each) finally drained and blotted gently. 4.diluted primary antibody was applied to each slide, incubated in humid chamber at37ºc overnight .early in the next day the slides were washed in distilled water (5minutes ),then in pbs(5minutes), finally drained and blotted gently as before. 5. each drops of biotin were added and incubated humid chamber at37 ºc. for 30 minutes, then washed in distilled water and pbs (5 minutes for each) finally drained and blotted gently. 6. at the same time prepare solution a & b were prepared and incubated in humid chamber at 37ºc for 30 minutes. 7. each drops of solution a&b were added and incubated humid chamber at 37 ºc for 30 minutes, then washed in distilled water and pbs(5minutesfor each)finally drained and blotted gently. j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 59 8. diluted dab was applied on tissue(this process was done in dark room) and incubated in humid chamber for 10 minutes at37ºc.then slides washed carefully in tap water for 5 minutes . 9. the slides were bathed in hematoxylin counterstain for 1-2 minutes then they were rinsed with tap water for 10 minutes. 10. dehydration: the slides were dehydrated by immersing them in ethanol and xylene containing jars as follows: • 70% ethanol for 1 minute. • .95% ethanol for 1 minute. • twice in absolute ethanol for 1 minute each. • twice in xylene for 1minute. 11. one to two drops of dpx mounting medium were applied to the xylene wet sections and covered with cover slips and left to dry overnight. evaluation of immunohistochemistry results: positive reading was indicated when cells display a brown cytoplasmic pigmentation staining for fas,membraneous pigmentation staining for fasl and nuclear and cytoplasmic pigmentation staining for c-myc while negative reading was indicated for absence of immunostaining. immunohistochemical scoring of fas/fasl and c-myc: the scoring was done under light microscope under 20x objective and because the staining intensity was not uniform among different lesion, we scored the antibodies with the rate of positive cell. in each tissue section five representative fields (area show preserved histopathological appearance of olp with an everage of 1000 cell per case & 200 cells per field. the fas,fasl immunoreactivity of positive cells was scored as follows: 0: as negative or nonreactive. 1: 1%-25% of positive cells. 2: 26%-50%of positive cells. 3:51%-75%of positive cells. 4 :> 75% of positive cells (murray b, 2000). the c-myc immunoreactivity of positive cells was scored as follows : 0: as negative or nonreactive. 1: 1%-10% of positive cells. 2: 11%-50% of positive cells. 3: 51%-80% of positive cells. 4:>80% of positive cells (m.k.schmidt,2007). statistical analysis: descriptive statistics: numerical values were used in this study for describing the variables which includes: no. mean, sd for age, fas, fasl and cmyc. categorical variable which includes: sites, grade, gender and clinical presentation were described using no. and percentage. 1. data concerning the studied characteristics of olp were described by their mean and frequency of occurrence. 2. mean were described by their relative standard deviation to indicate variability. 3. frequency tables were constructed to display the count of occurrence of each characteristic in olp. 4. spearman correlation was used to express relative relation between any two ordinal variables. the sign of this correlation indicates the direction of the relationship whether positive or negative between these two variables. statistical analysis using spss (statistical package for social sciences) v17 (2008) was used and the p-value less than 0.05 was considered significant. results clinico pathological finding age and sex distribution in olp: in this study the mean age for 30 cases included was (47) years. the age ranged from 19 to 75 years. cases in the age group of more than 40 years comprise about 63.33% of the samples (19 cases), while 36.66% of the (11) cases were in the age group less than 40 years(table 1). table 1: age distribution of the olp cases. age no. % <40 19 63.33 40> 11 36.66 total 30 (100%) regarding the sex distribution of the studied samples results showed that 60% (18) cases were males and 32% (12) cases were females .the male to female ratio was 1.5:1. (table 2). table2: sex distribution of the olp cases. sex no. % male 18 60 female 12 40 total 30 (100%) lesion site distribution: regarding the lesion site involved by olp, the most affected site in this study was the buccal mucosa which comprised 76.66% (23cases), followed by tongue and check which comprised 6.66%(2 cases) for each, followed by lips and vermilions and lower residual ridge 3.33 % (1 case) for each ( table 3). j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 60 table 3: lesion site distribution of the olp cases lesion site no. % buccal mucosa 23 76.66 tongue 2 6.66 check 2 6.66 lower residual rigde 1 3.33 vermilions 1 3.33 lips 1 3.33 total 30 (100%) clinical presentation: the majority of cases were appeared in the white lesion 76.66% (23 cases), followed by red lesion 20% (6 cases), and yellow brown 3.33% (1 case). (table 4). table 4: clinical presentation of olp cases % no. clinical presentation 76.66 23 white lesion 20 6 red lesion 3.33 1 yellow brown lesion 100% 30 total immunohistochemical evaluation evaluation of fas immunohistochemistry both(epithelial & inflammatory): the immunohistochemical staining of fas in keartinocytes was positive in 29 (96.66%) of examined olp cases, of which 5 cases (16.66%) showed low positive expression, 11 cases (36.66%) showed moderate positive expression, 6 cases (20%) showed high positive expression and 7 cases (23.33%) showed very high positive expression . immunostaining of fas was detected as brown (granular) in the cytoplasm especially of keratinocyte cells. (figure 1,2). fas epithelial expressions for 30 olp cases were summarized in (table 5). table 5: fas expression in epithelial cells of olp cases fas expression no. % negative 1 3.33 low positive 5 16.66 moderate positive 11 36.66 high positive 6 20 very high positive 7 23.33 total 30 (100%) concerning the fas expression in lymphocytes, results of present study revealed positive in 20 (66.66%) examined olp while10 cases (33.33%) showed negative expression for fas. of positive cases, 6 cases (20%) showed low expression, 7 cases (23.33%) showed moderate expression and 7 cases (23.33%) showed high expression. (figure 1, 2 and table 6). table 6: fas expression in inflammatory cells of olp cases fas expression no. % negative 10 33.33 low positive 6 20 moderate positive 7 23.33 high positive 7 23.33 very high positive 0 0 total 30 (100%) figure 1 :positive immunostaining of fas in olp (20x) figure 2:positive immunostaining of fas in olp (40x) evaluation of fasl immunohistochemistry both (epithelial & inflammatory): the immunohistochemical staining of fasl epithelial cells of olp was positive in 29 (96.66%) examined olp, 4 cases (13.33%) show low positive expression, 3 cases (10%) show moderate positive expression, and 8 cases (26.66%) show high positive expression and 14cases (46.66%) show very high positive expression. immunostaining of fasl epithelial was detected as brown (granular) staining in the cytoplasm of keratinocyte cells.fig (3,4). fasl epithelial expressions for 30 olp cases were summarized in (table 7). j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 61 table 7: fasl expression in epithelial cells of olp cases fasl expression no. % negative 1 3.33 low positive 4 13.33 moderate positive 3 10 high positive 8 26.66 very high positive 14 46.66 total 30 (100%) concerning the immunohistochemical staining of fasl in lymphocytes of olp cases, results showed positive expression in 29 examined olp immunostaining of fasl was detected as brown (granular) staining in the cytoplasm of inflammatory cells. (figure 3,4). fasl inflammatory expression for 30 olp cases was summarized in table 9. of 29 (96.66%) positive cases, 5 cases (16.66%) show low positive expression, 8 cases (26.66%) show moderate positive expression, while 16 cases (53.33%) show high positive expression with 1 case (3.33%) showed negative expression. table 8: fasl expression in inflammatory cells of olp cases fasl expression no. % negative 1 3.33 low positive 5 16.66 moderate positive 8 26.66 high positive 16 53.33 very high positive 0 0 total 30 (100%) figure 3: positive immunostaining of fasl in olp (20x) figure 4: positive immunostaining of fasl in olp (40x) evaluation of c-myc immunohistochemistry in(epithelial & inflammatory) of olp: the immunohistochemical staining of c-myc in epithelial cells of olp was positive in 29 (96.66%) examined cases. of which2 case (6.66%) show low expression, while 6 cases (20%) show moderat expression, 8 cases (26.66%) show high expression and13cases (43.33%) show very high expression. (table 9). immunostaining of c-myc was detected as brown (granular) staining in the cytoplasm and nucleus of keratinocyte cells. fig (5,6). table 9: c-myc expression in epithelial cells of olp cases c-myc expression no. % negative 1 3.33 low 2 6.66 moderat 6 20 high 8 26.66 very high 13 43.33 total 30 100% concerning the immunohistochemical expression of c-myc in inflammatory cells of olp was positive in 29 (96.66%) examined cases of which 2 case (6.66%) show low expression, 7 cases (23.33%) show moderate expression, while 7 cases (23.33%) show high expression and 13 cases (43.33%) show very high expression. table 10: c-myc expression in inflammatory cells of olp cases c-myc expression no. % negative 1 3.33 low 2 6.66 moderate 7 23.33 high 7 23.33 very high 13 43.33 total 30 100% j bagh college dentistry vol. 25(1), march 2013 immunohistochemical oral diagnosis 62 immunostaining of c-myc was detected as brown (granular) staining in the cytoplasm and nucleus of inflammatory cells.(table 10 and figure 5,6). figure 5: positive immunostaining of c-myc in olp (20x) figure 6: positive immunostaining of c-myc in olp (40x) references 1. brad nw, carl ddm, jeery me. oral maxillofacial pathology 3rd ed. saunders; 2009. 2. elazebith vl, brieva j, schachter m, west le. successful treatment of erosive lichen planus with topical tacrolimus. arch dermatol 2001; 137: 1425. 3. rikkia m. molecular markers in oral lichen planus.from the department of oral pathology and radiology, institute of dentistry and department of pathology, institute of microbiology and pathology, faculty of medicine, university of turku, 2009. 4. sugerman pb, savage nw, walsh lj, zhao zz, zhou xj, khan a, seymour gj, bigby m. the pathogenesis of oral lichen planus. crit rev oral biol med 2002; 134:350-65. 5. leithauser f, dhein j, mechtersheimer g, et al. constitutive and induced expression of apo-1, a new member of the nerve growth factor/tumor necrosis factor receptor superfamily, in normal and neoplastic cells. lab invest 1993; 69: 415-27. 6. peter me, kischkel fc, hellbrandt s, et al. cd95 (apo-1/fas)-associated signalling proteins. cell death differ 1996; 3: 161-70. 7. nagata s. apoptosis by death factor. cell 1997; 88: 355-65. 8. griffth ts, bruner t, fletcher sm, green dr, ferguson ta. fas ligand-induced apoptosis as a mechanism of immune privilege. science 1995; 270: 1189-92. 9. hunt js, vassmer d, ferguson ta, miller l. fas ligand is positioned in mouse uterus and placenta to prevent trafficking of activated leukocytes between mother and the conceptus. j immunol 1997; 158: 4122-8. 10. henriksson m, luscher b. proteins of the myc network:essential regulators of cell growth and differentiation. advances in cancer research 1996; 68: 109–82. nidhal f.doc j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 58 histological evaluation of the effect of topical application of curcumin powder and essential oil on skin wound healing nidhal hussein muhammad, b.d.s. (1) ban a. ghani, b.d.s., m.sc., ph.d. (2) abstract background: herbal medicine can be called one of the branches of medicine in various forms. turmericcurcumin has proved its efficiencies a coloring, flavoring agent and has been traditionally used in medicine, exhibiting remarkable anti-inflammatory and antioxidant properties. the varied biological properties of curcumin and lack of toxicity even when administered at higher doses makes it attractive to explore its use in various disorders like diseases of skin. it is good potential agent for wound healing. materials and methods: sixty four new zealand rabbits were used in this study ,they were divided into four groups,each group was subdivided as follows: experimental groups(8 rabbits) right facial side of animals for essential oil application and left facial side animals for curcumin powder application, 8 animals as control group(right facial sides) .histological assessment regarding the count of inflammatory cells was performedon all studied samples for the healing intervals (3, 7, 10, and14 days). results: histological findings of the study showed that re-epithelialization, wound contraction were accelerated after topical application of curcumin material especially the essential oil at wound site. conclusion: topical application of curcumin essential oil was significantly effective in skin wound healing as compared to curcumin powder. key words: curcumin, cutaneous wound-healing, topical application, essential oil. (j bagh coll dentistry 2015; 27(3):58-63). introduction skin, is the largest soft outer covering organ in the body. it has several functions, the most important being to form a physical barrier to the environment, allowing and limiting the inward and outward passage of water, electrolytes, various substances and protection against microorganisms (1). skin is composed of three primary layers. the epidermis; which provides water proofing and serves as a barrier to infection. the dermis; which serves as a location for the appendages of skin.the inner most layer is hypodermis (2). wound is generally a knowledge tissue damage resulting in the disruption of the original tissue artchecture and homeostasis (3).wound healing, as a normal biological process, achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. for a wound to heal successfully, all four phases must occur in the proper sequence and time frame (4). turmeric scientific name is curcuma longa, is a plant that belongs to the ginger family zingiberacear. one of the most important components is a substance called curcumin. considerable interest has been focused on curcumin compound; mechanisms that drive wound repair are complex and have challenged wound-healing investigators for many years (5). (1)master student. department of oral diagnosis, college of dentistry, university of baghdad (2)assist. professor. department of oral diagnosis, college of dentistry, university of baghdad curcumin treatment reduces wound-healing time, improves collagen deposition and increases fibroblast and vascular density in wounds thereby enhancing both normal and impaired woundhealing. the beneficial effects of curcumin and the potential of this compound to be developed as a potent nontoxic agent for treating skin diseases (6). turmeric essential oil contains hundreds of molecules antimicrobial, effects, antioxidant effects, antifungal effect, inflammation and edema effects (7). materials and methods materials • curcumin powder (fluka /germany) • essential oil(hemani/pakestan) • anesthetic solution: ketamine hydrochloride (ketamin 50mg/ml) {1 ml/kg body weight}; xylocain (10%){1 ml/kg body weight}. • zylazine (20mg/ml). • formalin 10%, ethanol alcohol 96%, xylol, paraffin wax. • hematoxylen and eosin (h&e). methods sixty four adult rabbits weighting average of (1.25-2.5kg). experimental animals were divided into four groups, eight animals for each healing interval (3,7,10, and14 days). each group consists of (16) animals, experimental group (8 rabbits) and control group (8 rabbits).the animals of experimental group j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 59 were (8): animal ,right facial side for essential oil application, and animal left facial side for curcumin powder application. the animals were anesthetized, two centimeters (cm) length incisional woundwere made on the cheek at both side (right and left) control and experimental (oil and powder application), then left to heal spontaneously. all tissue specimens, samples and controls, were fixed in 10% neutral formalin and processed in a routine paraffin blocks. each formalin-fixed paraffin-embedded specimen had serial sections were prepared as follows: 5µm thickness sections were mounted on clean glass slides for routine haematoxylin and eosin staining (h&e), from each block of the studied sample (experimental and the control groups) for histopathological reexamination. analysis of number of inflammatory cells it was performed by counting inflammatory cells, in histological sections (h&e stained), for each animal and in four microscopic fields at x40 magnification.scores for intensity of inflammatory reaction: 1. absent or very few inflammatory cells. 2. mild: average number less than 10 inflammatory cells 3. moderate: average number 1025inflammatory cells 4. severe: average number greater than 25inflammatory cells (8). results three days duration; control group after three days: histological view of skin section at wound site, showed the migration of keratinocytes the wound surface, developing hair follicles with adjacent granulation tissue (figure 1). experimental group a-essential oil application microphotograph of facial skin section of 3days duration at wound site shows granulation tissue which is highly infiltrated with inflammatory cells (figure 2). b-curcumin powder application histological view at wound site after 3days of curcumin powder (cp) application shows granulation tissue with congested blood capillaries, and large number of inflammatory cells can be detected in the dermis (figure 3). figure 1: microphotograph of control group of 3days duration, shows keratinocytes migration at wound surface (kc), granulationtissue (gt), andhair follicles (hf). h&ex20. figure 2: view of wound site of oil group, after 3days shows granulation tissue that is highly infiltrated with inflammatory cells (ic). h&ex40 figure 3: view of wound site after3days of powder application, shows granulation tissue infiltrated by inflammatory cells (ic), and areas of blood congestion (arrow) h&ex40. j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 60 seven days duration control group skin section of 7days duration, shows the new epithelium formation, fibroblasts and collagen fibers are noticed (figure 4). experimental group a-essential oil application microphotograph of 7days duration at wound site shows the thin newly formed epithelium, loose fibrous connective tissue is detected in the dermis (figure 5). b-curcumin powder application histological view of facial skin section in the dermis of 7 days durations, shows numerous blood capillaries, surrounded by number of inflammatory cells, fibroblasts and remodeling collagen fibers (figure 6). figure 4: view of facial skin section of control group after 7days, shows, the new epithelium(ne),fibroblasts(fb), and fibers(arrows) in the dermis. h&ex 20. figure 5: microphotograph of 7days duration at wound site showsthe areas of blood congestion (arrows), few inflammatory cells(ic), collagen fibers and fibroblasts (fb) are illustrated. h&ex40. figure 6: histological view of section in the dermis after7days of powder application, shows blood capillaries (arrows), inflammatory cells(ic), fibroblasts (fb) and remodeling collagen fibers (collf). h&ex40. ten days duration control group view of facial skin section of 10days duration of control group, shows epithelium collagen fibers and fibroblasts (figure7). experimental group a-curcumin oil application microphotograph of 10days duration at wound site shows maturing fibrous connective tissue, blood vessels (figure 8). b-curcumin powder application histological view of facial skin section, of powder group after 10days, shows that the wound surface is covered by thin epithelium, numerouscongested blood vessels, remodeling fibers and fibroblasts (figure9). figure 7: view of 10days duration of control group, shows the new epithelium(ne), collagen fibers (collf) and fibroblasts(fb). h&ex40. j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 61 figure 8: view of wound site, of oil group after 10days duration, shows fibrous connective tissue, blood vessels (bv), surrounded by remodeling fibers. h&ex10. figure 9: histological view after 10days of powder application, shows wound surface is covered by thin epithelium, underlying mesenchyme shows numerous blood vessels (bv). h&ex20. fourteen days duration control group microphotograph of facial skin section of control group after 14 days, it is noticed that epihelium is thin without rete-ridges ,fibrous connective tissue with decrease cellularity is shown, besides developing hair follicles are detected (figure10). experimental group a-curcumin oil application microphotograph of 14 days duration ,after oil application, shows complete healing of the wound, mature fibrous connective tissue, fibroblasts are arranged alongside the collagen fibers, proliferating hair follicles and blood vessels are seen (figure11). b-curcumin powder application histological view of facial skin after 14 days of powder application, shows complete healing of wound , the cell layers of the new epithelium that covers wound surface are illustrated, it is obvious that there is reduction of cellular population, and establishment of dense mature collagen fibers (figure 12). figure 10: microphotograph of control group after 14days, new epithelium (ep), fibrous connective tissue with decrease cellularity is shown, proliferating hair follicles(hf) are detected.h&ex40. figure 11: view of wound site of oil group after 14days, shows mature fibrous connective tissue, with multiple blood vessels (bv), fibroblasts (fb) and numerous hair follicles (hf).h&ex20. j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 62 figure 12: view of wound site of powder group after 14days, shows the new epithelial cell layers (ep), the underlying mesenchym shows dense mature collagen fibers (collf). h&ex40. inflammatory cells assessment the results of the present study have shown a higher count numbers of all estimated inflammatory cells for experimental group ,there was significant difference in the mean score of inflammatory cells at day 3, in which the control group significantly differ from other groups it had the lowest mean values. at day 7, there was no significant difference between the groups. whereas significant difference between the groups with p<0.05 was shown after10 days healing period. highly significant difference was recorded between the groups at day 14 (table1). figure shows that mean values of inflammatory cells were decreasing throughout the four healing intervals which were well noticed in experimental oil group. table1: comparison between different groups in different periods regarding score of inflammatory cells. hp score control ms sd e .oil ms sd powder ms sd p value no % no % no. % 3 days 1 0 0 19.2 3.81 0 0 34 8.56 0 0 27.5 8.05 0.001** 2 3 37.5 0 0 0 0 3 5 62.5 1 12.5 4 50 4 0 0 7 78.5 4 50 7 days 1 0 0 14.5 4.95 0 0 23.5 6.73 0 0 17.7 5.05 0.429 2 3 37.5 1 12.5 3 37.5 3 5 62.5 6 75 4 50 4 0 0 1 12.5 1 12.5 10 days 1 0 0 16 5.2 0 0 11.2 4 0 0 14.2 4.7 0.044* 2 2 25 7 87.5 5 62.5 3 6 75 1 12.5 3 37.5 4 0 0 0 0 0 0 14 days 1 0 0 9.7 3.2 5 62.50 2.2 0.3 3 37.5 5.7 1.7 0.009** 2 4 50 3 37.50 4 50 3 4 50 0 0 1 12.5 4 0 0 0 0 0 0 *significant, **highly significant figure 13: mean score of inflammatory cells in different periods in the studied groups. discussion wound healing is a complex process that involves inflammation, granulation and tissue remodeling. interactions of different cells, extracellular matrix proteins and their receptors are involved in wound healing, and are mediated by cytokines and growth factors (9) the use of herbal therapies for caring of wounds and injuries has been popular since ancient civilizations. in contrast to only 1–3% of modern drugs being used for the treatment of wounds and skin disorders (10). the results of this study showed clear promotion of healing in the experimental groups with (curcumin oil and powder)in comparison with the control groups ,mean values of j bagh college dentistry vol. 27(3), september 2015 histological evaluation oral diagnosis 63 inflammatory cells were higher in experimental groups with (oil and powder), than in controls, then decreased with time, throughout the four healing intervals, indicating accelerated inflammatory reaction with application of curumin. the histopathological examination observed that the good response of these groups may be related to stimulation of inflammatory cell or activation of the chemotactic factor, at 3 days period, the wound site filled with a highly vascularized and proliferating granulation tissue. also confined by study conducted by hussein et al where histopathological findings showed hemorrhage with inflammatory cell infiltration, as well as congested blood vessels (11). at 7 days, histological findings showed, thin new epidermis covering wound surface in studied groups, and fibrous connective tissue ,with fibroblasts and remodeling collagen fibers with areas of blood congestions, which was obviously seen in experimental groups where complete reepithelialization of the surface, presence of collagen fibers ,inflammatory cell infiltration was evident ,this agreement with lemo et al.(12) 10 days, re-epithelialization was complete. the underlying dermis showed remodeling immature collagen fibers, inflammatory cells are few, agreed with findings of hussein et al. (11) cellular fibrous connective tissue with congested blood vessels and infiltration of few inflammatory cells covered by thick, larger cellular epidermis was detected in the present study after 14 days, in disagreement with jawad et al. who studied the histological healing response of the soft tissue incisions created by scalpel prepared on rabbit's skin specimens (13). as conclusions; topical curcumin represents simple and inexpensive model of wound healing enhancement and curcumin essential oil is more effective in enhancement of wound healing regarding histological assessment. inflammatory cells had highest mean values, especially with oil group, and these values decreased with time. besides highly significant difference was recorded between the studied groups at day 14. references 1. berk l, matsudaira z, darnell b. molecular cell biology. 4th ed. w.h. freeman & co; 1999. 2. dawson tl, ro bi. the role of sebaceous gland activity and scalp micro-oral metabolism in the etiology of seborrheic dermatitis and dandru. j investigative dermatol sp 2005; 10(3): 194 3. gurtner gc. wound repair and regeneration. nature 2008; 433: 3141-53. 4. breitkreutz d, mirancea, nischt rb assessment membranes in skin: unique matrix structures with diverse functions. histochemistry and cell biology j 2009; 132(1): 1-10. 5. thangapazham rl, sharma a, maheshwari rk. beneficial role of curcumin in skin diseases. adv exp med biol 2007; 595: 343-57. 6. campos ac, groth ak, branco ab. assessment and nutritional aspects of wound healingcurentr opinion clincal nutrition metabolic care 2008;11(3): 28154. 7. ferreira fd, aparecida s, mossini g, et al..the inhibitory effects of curcuma longa l. essential oil and curcumin on aspergillusflavus. link growth and morphology the scientific world j 2013; 2: 6. 8. accorinte m, holland r, reis a, bortoluzzi m and muratess.union of mineral trioxide cement as pulp capping agent in teeth. j endod 2008; 34:1-6. 9. sidhu gs, mani h, gaddipati jp, singh ak, seth p, banaudha kk, patnaik gk, maheshwari rk. curcumin enhances wound healing in streptozotocin induced diabetic rats and genetically diabetic mice. wound repair regen 1999;7: 62-74 10. nezhad hr, shahri nm, rakhshandeh. the importance of turmeric extract on wound repair in rat. animals of biological research, 2013; 4(12):123-8. 11. hussein aj, alfars aa, falih maj, hassan a-na. effects of a low level laser on the acceleration of wound healing in rabbits. north am j med sci 2011; 3: 193-7. 12. lemo n, marignac g, reyes-gomez, lilin t, crosaz o. cutaneous re-epithelialization and wound contraction after skin biopsies in rabbits: a mathematical model for healing and remodelling index arhiv 2010; 80: 637-52. 13. jawad mm, khursheed alam mk, abdul qader st, al-azzawi lm, husein a, mahmood as. histological evaluation of incision healing response made by metallic scalpel on rabbits skin: preliminary study. international medical j 2013; 20(4): 496-8. 3. iman f.doc j bagh college dentistry vol. 25(1), march 2013 push-out bond restorative dentistry 14 push-out bond strength of different root canal obturation materials sundus h. naser, b.d.s. (1) iman m. al-zaka, b.d.s., m.sc. (2) abstract background: the aim of this study was to evaluate the push-out bond strength of four different obturation materials to intraradicular dentin and to determine the failure mode. materials and method: forty straight palatal roots of the maxillary first molars teeth were used in this study, the roots were instrumented using crown down technique and rotary endosequence system, the roots were randomly divided into four groups according to the materials used for obturation (n=10).group (1): ah plus sealer and gutta-percha. group (2): activ gp glass ionomer sealer and activ gp gutta-percha (activ gp system). group (3): bioceramic sealer and bioceramic gutta-percha. group (4): guttaflow2 sealer and gutta-percha. for all groups single cone obturation technique was used. after incubation period of one week, the roots were embedded in clear acrylic resin and each root sectioned into three levels apical, middle and cervical. the bond strength was measured using computerized universal testing machine, each section fixed in the machine so that the load applied from apical to coronal direction at 0.5mm/min speed and the computer drew curve to show the higher bond force before dislodgment of the filling material. after de-bonding each sample was examined under stereomicroscopic and the type of failure mode was recorded. results: showed a non significant difference between ah plus group and bioceramic group. ah plus group showed a very highly significant difference with activ gp group and a highly significant difference with guttaflow2 group. there were significant differences between coronal level and both apical and middle levels with no significant differences between apical and middle levels within each group. conclusion: ah plus group showed the highest mean of bond strength in comparing to other tested groups. keywords: bond strength, push-out test, adhesive sealer, obturation materials. (j bagh coll dentistry 2013; 25(1):14-20). introduction successful root canal treatment depends on the thorough debridement of the root canal system, the elimination of pathogenic organisms and finally the complete sealing of the canal space to prevent ingress of bacteria from the oral environment and spread to the periapical tissue (1). the physical properties necessary for this function include adaptation and adhesion of the filling material to the root canal wall, because guttapercha does not directly bond to the dentin surface, the sealer should be capable of producing a bond between core material and dentin wall (2). different types of sealer have been introduced to endodontics, including those based on zinc oxide eugenol, calcium hydroxide, glass–ionomer cement and a range of resins. epoxy resin-type sealers have been used for many years. they showed higher bond strength to dentin than zinc oxide eugenol types and calcium hydroxide-based sealer (3). in recent years, different filling materials and sealers have been developed on the basis of dentin adhesion technology in an attempt to seal the root canal more effectively, and to increase fracture resistance of root filled teeth (4). furthermore, manufacturers have further incorporated adhesive dentistry in endodontics by introducing obturation systems with a specific focus on obtaining a “monobloc” in which the core material, sealing agent, and root canal dentin form a single cohesive unit (5). both activ gp precision system and bioceramic sealer are based on adhesion technology (6). activ gp is a system which utilizes improved glass ionomer (gi) technology (both as a sealer and as a special gi coated gutta percha cone) to create a true single cone monoblock obturation (7). activ gp sealer is superior to previous gi-based systems in terms of handling characteristics, working time, radiopacity (8) and seal, because of the increased of its flowability (9,10). bioceramic sealer (bc) is a new premixed sealer, ready-to-use injectable and hydraulic cement paste. it is composed of calcium phosphate, calcium silicate, calcium hydroxide, zirconium oxide, filler, and thickening agents. bioceramic sealer have dimensional stability and don’t shrink upon setting, consequently, remains non restorable inside the root canal (6). guttaflow®2 sealer is an alternative root filling material introduced into the endodontic practice. guttaflow®2 is a cold flowable filling system for root canals, combining sealer and gutta-percha in one product. adhesion properties of root canal sealers to dentin are determined by several mechanical tests. push-out test has been described to measure the bond between sealer, canal wall and the core material (11,12). the aim of this study was to compare the bond strength of different root canal obturation materials. materials and methods forty freshly extracted maxillary first molars teeth with straight palatal root were selected from (1)m.sc. student. department of conservative dentistry, college of dentistry, al-mustanseria university. (2)assistant professor. department of conservative dentistry, college of dentistry, al-mustanseria university. j bagh college dentistry vol. 25(1), march 2013 push-out bond restorative dentistry 15 different health centers for this study according to specific criteria. after extraction, all teeth were stored in 0.1% thymol solution at room temperature. the roots surfaces were verified with a magnifying eye lens (10x) and light cure device for any visible cracks or fractures. using diamond disc mounted on straight hand-piece and under water coolant the palatal root of teeth was sectioned perpendicular to the long axis of the root at the furcation area to facilitate straight line access for canal instrumentation and filling procedure. the length of the root was determined by digital caliper and marker to (10) mm from apex to cement-enamel junction. the exact location of the apical foramen and the patency of the canals were verified by insertion of a no.15 k-file into the canal and advancing until it is visualized at the apical foramen. the root canals were prepared with crown-down technique to master apical file #40 using 0.06 taper endosequence niti rotary instruments (brasseler usa, savannah) at 500 rpm and 1.2 n/c torque. five millimeter of 2.5% naocl with 27-g syringe was used for irrigation between each file size with a final rinse of 5 ml, 17% edta (pd swiss quality) for 1min. followed by copious amounts of distilled water to remove any remnant of the irrigation solutions (13,14). samples grouping the roots were randomly divided into four groups (n=10) according to type of obturation materials, for all groups single cone obturation technique was used: group (1): in this group, the ah plus sealer (dentsply, germany) mixed according to the manufacture's instructions. the tip of master cone #40/.06 was coated with the ah plus sealer and placed into canal to full working length (fig.1). group (2): canals were obturated with activ gp root canal obturation system (brasseler usa, savannah), (fig.2). after the root canals were dried with master paper points, activ gp sealer powder and liquid in (3:1) ratio mixed following the manufacture's instructions. then the apical half of activ gp master cone #40/.06 was coated with sealer and inserted slowly in the canal with circular motion until it reach full working length. group (3): in this group the endosequence bc sealer and endosequence bc gutta-percha were used (brasseler usa, savannah), (fig.3). the obturation was performed with a #40/.06 bc gutta-percha master cone in combination with bc sealer according to the manufacturer's instructions. then the master bc gutta percha cone was coated with a thin layer of sealer, and very slowly inserts it into the canal. group (4): canals were obturated with #40/.06 gutta-percha and guttaflow2 sealer (coltene,germany) according to the manufacturer's instructions (fig.4). guttaflow®2 was spread on a mixing slab and inserted into the root canal with the master file #40 then the master cone #40/.06 coated with sealer and inserted to the working length. for all groups excess gutta-percha was removed with hot plugger 1mm below the orifice. all obturated roots of all groups were wrapped in saline moistened gauze in closed plastic vial allowing the sealer to set for 7 days at 37°c in an incubator (19). after the storage period, the roots were embedded in clear orthodontic resin (15). the sectioning of root was made by using diamond cut-off saw. four cut was made horizontally to obtain three sections (apical, middle, and coronal) of 2 mm in thickness , three sections were obtained (2), (4.5), and (7) mm from true anatomical apex. the thickness of each section was measured with a digital caliper, thus, each study group of (10) roots provided a total of (30) test specimens, consisting of (10) specimens from each root region. push-out bond strength test push-out test was performed by applying a compressive load to the apical aspect of each slice via a cylindrical plunger mounted on tinius-olsen universal testing machine managed by computer software. samples were examined under the nikon metallurgical microscope (magnification 50x) and pictures of both sides of each section are taken with digital camera which was connected with microscope, and measurements calculated using lucia g software analysis program. the obturated area of the section at each level was measured from the apical side to determine the size of punch pin (16).three different sizes of punch pins were used, 0.7 mm diameter for the coronal slices, 0.55 mm diameter for the middle slices and 0.4 mm diameter for the apical slices. the punch pins should provide almost complete coverage over the main cone without touching the canal wall and sealer (13,16) . the root filling in each section subjected to loading using a universal testing machine (wdw50) at a speed of 0.5 mm / min in an apical-coronal direction until the first dislodgment of obturating material and a sudden drop along the load deflection. the maximum failure load was recorded in newton (n) and was used to calculate the push-out bond strength in megapascals (mpa) according to the following formula (17): push-out bond strength (mpa) = j bagh college dentistry vol. 25(1), march 2013 push-out bond restorative dentistry 16 anova test and lsd test was performed as statistical analysis for push-out bond strength. analysis of failure modes after the push-out bond strength test, each sample was inspected with a stereomicroscope (kruss, germany) at 40x magnification to determine the failure mode. each sample was evaluated and placed into one of 3 failure modes (16, 18): type i: adhesive failure, either at the sealer-dentin (s/d) or between the sealer-core (s/c) interfaces, type ii: cohesive failure, within the filling material (sealer or core material), type iii: mixed failure, which contains both adhesive and cohesive failures. results mean values and standard deviation for all groups presented in (table-1). ah plus group has the highest mean values at all levels in comparison with other groups followed by bc group, then guttaflow2 group, while activ gp group has the lowest mean value at all levels. the coronal level in all groups has the highest mean push-out bond strength values, followed by middle and then the apical level (fig.5). analysis of variance (anova) test was performed and showed that there were very highly significant differences (p≤0.001) at all levels (table-2). there was no significant difference between group1 (ah plus) and group3 (bioceramic) at all levels (p ≥ 0.05). and also there was no significant difference between group2 (activ gp) and group4 (guttaflow2) at all levels (p ≥ 0.05). group1 (ah plus) showed a very highly significant difference (p ≤ 0.001) with group2 (activ gp) and a highly significant difference (p ≤ 0.01) with group4 (guttaflow2) at all levels (table-3). anova test between different levels within each group showed that there was a highly significant difference (p ≤ 0.01) among different levels within each group (table-4). the least significance difference test (lsd) was performed to confirm the results of anova test between each two levels for each groups and showed a significant difference between coronal level with both middle and apical levels and there was a non significance difference between apical and middle level in all groups (table-5). analysis of failure mode the analysis of failure mode for push-out test was shown that the predominant mode of failure in ah-plus group was adhesive failure (s/g) and mixed failure. in the activ gp group the failure mode was predominantly cohesive failure within the gutta-percha itself and adhesive failure at s/d interface. the failure mode in the bc group was a cohesive failure mainly within the gutta-percha and mixed failure. finally the failure mode in the guttaflow2 group was adhesive failure mainly at s/g with some failure at s/d interface (table-6). discussion many obturation systems were proposed to the endodontics as to approach the good sealing ability and adhesion to dentin. despite the inadequate levels of bond strength between most current endodontic sealers and root dentin and gutta-percha (19,20) the adhesion of sealers to intraradicular dentin via frictional resistance, chemical bond, or micromechanical retention is still necessary in maintaining the integrity of the sealer-dentin interface during mechanical stresses caused by; tooth flexure, operative procedures, or subsequent preparation of a post space (21, 22). the ah plus group showed the highest mean of pushout bond strength. the highest bond strength of ah plus could be explained by the formation of a covalent bond by an open epoxide ring to any exposed amino groups in collagen (23). other investigations have further shown high-quality properties with epoxy resin–based sealers, including very low shrinkage while setting, longterm dimensional stability, flow, and long setting time, ah plus sealer penetrates deeper into the surface microirregularities (24). this agrees with the finding of fisher et al.(13) and sagsen et al.(25) . a highly significant difference was shown between ah plus group and the activ gp group, like other self-curing gi cements and resin composites, may have undergone shrinkage during its setting phase creating gaps between the sealer and root dentin(26) . this result may be also attributed to the non homogeneous mix of gi sealer which is questionable which might have an adverse effect on it is properties. moreover when comparing activ gp group with ah plus group in mechanisms of bonding, different mechanisms of bonding of both sealers played a role. the removal of the smear layer, by edta improves micromechanical retention of ah plus sealer but also depleted calcium ions which are necessary for the activ gp bonding. this result is in agreement with fisher et al (13), hashem et al. (27) and elsheikh et al (18). when comparing the ah plus group with bc group no significant difference was found between them at all levels. shokouhinejad et al. (14) also found a non significant difference in the push-out bond strength between ah plus and bc sealer. this could be related to the combined effect of the chemical and mechanical bonding of j bagh college dentistry vol. 25(1), march 2013 push-out bond restorative dentistry 17 the bc sealer to dentin wall (formation of hydroxyapatite during the setting) as well as the chemical bonding between the sealer and bc core material might have resulted in a significantly increased push out bond strength of bc sealer (28,29). guttaflow2 group showed a significant difference with ah plus group and bc group. according to tummala et al.(30) the wettability of the root canal sealers influences its adaptability to the radicular dentin. ah plus sealer was shown to wet the root dentin surface better than the guttaflow sealer and this could be attributed to its ability to penetrate into the micro-irregularities better. guttaflow showed poor wetting on the root dentin surface because of the presence of silicone, which possibly produces high surface tension forces, making the spreading of these materials less (30). the bond strength value decreased in a coronal to apical direction and showed significant difference between the coronal and apical level with no significant difference between apical and middle levels. the explanation for this may be that the apical dentine contains less patent tubules than coronal dentine and the more complex structure of tubular dentine apparently yields itself better to infiltration compared to the sclerotic apical counterpart. this agrees with the finding of nagas et al. (31) and al-hamed et al. (32). the predominant mode of failure for ah plus group was adhesive failure at s/g. elsheikh et al.(18), showed that the failure mode for ah plus was adhesive mainly between sealer and main cone and partially between sealer and dentin. furthermore nagas et al.(33) revealed that the failure mode was adhesive mainly between the gutta-percha and the ah plus sealer. the predominant mode of failure for activ gp group was adhesive at s/d interface and cohesive failure within the core material itself which might be due to weakening in the gutta-percha when sialinated with coating (18), and the nonhomogeneous coating of gi particle on the surface of the activ gp cone which may be contributed to less favorable bonding(34). in bc group the predominant mode of failure was also cohesive within the bc cone and this may be also attributed to weak and unfavorable distribution of the bc coating on the surface of bc cone. the predominant mode of failure for guttaflow2 group was adhesive failure mainly at s/g and some adhesive failure at s/d interface and this could be attributed to the lack of chemical union between sealer and gutta-percha or sealer and dentin. within the limitation of the present study the push-out bond strength of ah plus group was higher than other groups tested and the bond strength were affected by the tooth levels. references 1. sundqvist g, figdor d, persson s, sjo¨gren u. microbiologic analysis of teeth with failed endodontic treatment and the outcome of conservative retreatment. oral surg oral med oral pathol oral radiol endod 1998; 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11(4):166-75. 16. jainaen a, palamara j & messer h. push-out bond strengths of the dentine–sealer interface with and without a main cone. int endod j 2007; 40(11):88290. 17. nagas e, cehreli zc, durmaz v. regional push out bond strength and coronal micro leakage of resilon after different light curing methods. j endod 2007; 33(8):1464-70. j bagh college dentistry vol. 25(1), march 2013 push-out bond restorative dentistry 18 18. elsheikh am, mohamed ge and saba aa. push out bond strength of glass ionomer-impregnated gutta percha/glass ionomer sealer system to root canal dentin conditioned with different endodontic irrigants. eygpt dent j 2011; 57(3):2351-55. 19. schwartz r. adhesive dentistry and endodontics. part 2: bonding in the root canal system.the promise and the problems: a review. j endod 2006; 32:1125-34. 20. bouillaguet s, bertossa b, krejci i, wataha jc, tay fr, pashley dh. alternative adhesive strategies to optimize bonding to radicular dentin. j endod 2007; 33(10):1227-30. 21. saleh im, ruyter ie, haapasalo mp, ørstavik d. adhesion of endodontic sealers: scanning electron microscopy and energy dispersive spectroscopy. j endod 2003; 29(9): 595-6. 22. ayad mf, farag am, garcia-godoy f. effect of lactic acid irrigant on shear bond strength of epiphany adhesive sealer to human dentin surface. oral surg oral med oral pathol oral radiol endod 2010; 109(5): e100. 23. nunes vh, silva rg, alfredo e, sousa md, sousa yt. adhesion of epiphany and ah plus sealers to human root dentin treated with different solutions. braz dent j 2008; 19(1):46-85. 24. flores d, rached-júnior f, versiani m1, guedes d, sousa-neto m, pécora j. evaluation of physicochemical properties of four root canal sealers. int endod j 2011; 44(2):126-35. 25. sagsen b, ustun y, demirbuga s & pala k. push-out bond strength of two new calcium silicate-based endodontic sealers to root canal dentine. int endod j 2011; 44(12):1088-91. 26. monticelli f, sadek ft, schuster gs, volkmann kr, looney sw, ferrari toledano m, pashley dh, and tay fr. efficacy of two contemporary single-cone filling techniques in preventing bacterial leakage. int endod j 2007(a); 33(3):310-3. 27. hashem aa, ghoneim ag, lutfy ra, fouda my. the effect of different irrigating solutions on bond strength of two root canal-filling systems. j endod 2009; 35(4):537-40. 28. ghoneim ag, lutfy ra, sabet ne and dalia m. fayyad dm. resistance to fracture of roots obturated with novel canal-filling systems. j endod 2011; 37(11):1590-2. 29. candeiro g, correia f, duarte m, siqueira d. evaluation of radiopacity, ph, release of calcium ions, and flow of a bioceramic root canal sealer. j endod 2012; 36(6):842-5. 30. tummala m, chandrasekhar v, rashmi s, kundabala m, ballal v. assessment of the wetting behavior of three different root canal sealers on root canal dentin. j conserv dent 2012; 15(2):109-12. 31. nagas e, cehreli zc, durmaz v. effect of lightemitting diode photopolymerization modes on the push-out bond strength of a methacrylate-based sealer. j endod 2011(a); 37(6):832-5. 32. al-hamed mj, fouda my and ahmed gm. effect of different irrigates on the bond strength of bioceramic sealer to root canal dentin. egypt dent j 2011; 57(3): 2269-75. 33. nagas e, uyanik o, eymirli a, cehreli zc,vallittu p, lassila lv,and durmaz v. dentin moisture conditions affect the adhesion of root canal sealers. j endod 2012; 38(2):240-4. 34. monticelli f, sword j, martin rl, schuster gs, weller rn, ferrari m. sealing properties of two contemporary single-cone obturation systems. int endod j 2007(b); 40(5):374-85. table 1: descriptive statistics of push-out bond strength values (mpa) at three levels for all groups. groups level no. mean sd. se. min. max. group1 (ah plus) coronal 10 1.664 0.304 0.096 1.04 2.11 middle 10 1.276 0.319 0.101 0.81 1.81 apical 10 1.260 0.324 0.102 0.93 1.87 group2 (activ gp) coronal 10 1.105 0.314 0.099 0.83 1.85 middle 10 0.824 0.115 0.036 0.67 1.00 apical 10 0.817 0.170 0.054 0.59 1.12 group3 (bioceramic) coronal 10 1.591 0.283 0.089 1.25 2.08 middle 10 1.191 0.136 0.043 0.95 1.33 apical 10 1.155 0.121 0.038 1.02 1.40 group4 (guttaflow2) coronal 10 1.256 0.270 0.085 0.99 1.69 middle 10 0.950 0.216 0.068 0.67 1.33 apical 10 0.913 0.193 0.061 0.58 1.21 table 2: anova test for mean push-out bond strength among groups at each level level anova ss df ms f p-value sig. coronal level between group 2.133 3 0.711 8.289 0.000 *** within group 3.095 36 0.086 total 5.228 39 middle level between group 1.313 3 0.438 9.717 0.000 *** within group 1.627 36 0.045 total 2.941 39 apical level between group 1.274 3 0.425 9.149 0.000 *** within group 1.671 36 0.046 total 2.946 39 *** very highly significant j bagh college dentistry vol. 25(1), march 2013 push-out bond restorative dentistry 19 table 3: lsd test for mean push-out bond strength between four groups at each level level groups p-value sig. coronal level group1 group 2 0.000 *** group 3 0.581 n.s group 4 0.004 ** group2 group 3 0.001 ** group 4 0.257 n.s group3 group 4 0.015 * middle level group1 group 2 0.000 *** group 3 0.377 n.s group 4 0.002 ** group2 group 3 0.000 *** group 4 0.193 n.s group3 group4 0.016 * apical level group1 group 2 0.000 *** group 3 0.283 n.s group 4 0.001 ** group2 group 3 0.001 ** group 4 0.326 n.s group3 group 4 0.017 * *significant; ** highly significant difference; *** very highly significant; n.s non-significant difference. table 4: anova test for mean push-out bond strength among the different levels within each group groups anova ss df ms f-test p-value sig. group1 between group 1.047 2 0.523 5.245 0.012 * within group 2.694 27 0.1 total 3.741 29 group2 between group 0.54 2 0.27 5.738 0.008 ** within group 1.27 27 0.047 total 1.81 29 group3 between group 1.171 2 0.586 15.563 0.000 *** within group 1.016 27 0.038 total 2.187 29 group4 between group 0.709 2 0.354 6.774 0.004 ** within group 1.413 27 0.052 total 2.121 29 *significant; ** highly significant difference; *** very highly significant table 5: lsd test for mean push-out bond strength between the different levels within each group groups level p-value sig. group1 coronal & middle 0.011 * coronal & apical 0.008 *(* middle & apical 0.911 n.s group2 coronal & middle 0.007 ** coronal & apical 0.006 ** middle & apical 0.943 n.s group3 coronal & middle 0.000 *** coronal & apical 0.000 *** middle & apical 0.631 n.s group4 coronal & middle 0.006 ** coronal & apical 0.002 ** middle & apical 0.72 n.s *significant; ** highly significant difference; *** very highly significant; n.s non-significant difference. j bagh college dentistry vol. 25(1), march 2013 push-out bond restorative dentistry 20 table 6: failure modes for different groups groups mode of failure (no.) adhesive cohesive mixed s/d s/g within sealer within gutta-percha cohesive & adhesive group1 6 13 -------------------11 group2 10 ---------------14 6 group3 7 ----------------13 10 group4 10 14 -------------6 fig. 5: bar chart graph for mean push-out bond strength at each level of different groups j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 134 time of emergence of permanent teeth and impact of nutritional status among 4-15 years old children and teenagers in basrah city /iraq hiyam s. ahmed, b.d.s. (a) zeyneb a. al-dahan, b.d.s., m.sc. (b) abstract background: the timing of eruption of permanent teeth is of considerable importance to the dental health planning for diagnostic, preventive and therapeutic measures for children and teenagers. the purposes of this study were to determine timing of maxillary and mandibular permanent teeth emergence (except third molars) and to evaluate the effect nutritional status by anthropometric measures on the eruption time of permanent teeth, investigations had been done according to jaw and gender variations. materials and methods: this study was conducted among four to fifteen years old children and teenagers from kindergarten and schools in basrah city in the south region of iraq. the total sample composed of 1807 children and teenagers that were collected randomly from kindergartens, primary and secondary schools in basrah city. the data were statistically analyzed by using probit model in order to compute the median 5th and 95th percentile range of emergence. athropmetric measures of height and weight were used for the purpose of assessment of nutritional status. the indices include: weight for age, height for age and weight for height; each was considered as in term of standard deviation score (z – score) as primary indicator of underweight, stunting and wasting respectively. the statistical significance of differences in mean of a normally distributed variable (nutritional indices z score) between 2 groups was assessed by independent samples t-test. results: the results showed significant differences (p<0.05) between the timing of maxillary and mandibular teeth emergence in girls and boys, with earlier emergence in girls , also the mandibular teeth emerge before their maxillary opposing teeth in both sexes except for premolars . the prevalence of malnutrition according to height for age, weight for age, and weight for height nutritional status indicators were found to be 7.4 %, 3.7 % and 1.5% respectively. the results showed that among well-nourished children and teenagers described by height for age nutritional status indicator, most teeth were significantly erupted earlier than stunted except the lateral incisor which erupted earlier in stunted boys than well-nourished boys but the difference was not significantly accepted. the greatest difference of median eruption age of permanent teeth between well -nourished and stunted found in girls in the second molar tooth. conclusions: records indicated that the iraqi children exhibit variation in their times of permanent teeth emergence when compared with other studies, and among well-nourished children and teenaged described by height for age nutritional status indicator, most teeth were significantly erupted earlier than stunted children and teenagers. keywords: permanent teeth, tooth eruption, nutritional status. (j bagh coll dentistry 2016; 28(4):134-140) introduction tooth eruption is a continuous biological activity by which evolving teeth emerge across jaws and the overlying mucosa into the oral cavity (1). the school age period from childhood to adolescent is a critical life stage when health and oral health behaviors develop (2). many factors associated with eruption have been widely investigated. suggested factors which causing differences might include race (3) gender (4,5) hereditary factors (6,7) and nutritional status (8,9). many studies have been conducted throughout the world concerning dental development and timing of permanent teeth emergence, all of which agreed that a wide margin of variation existed between population groups (10-12). (a) m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, baghdad university. (b) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. also there are many studies conducted in different population and among different ethnic groups all over the world that relate the eruption time with the weight and height as an anthropometric measures of nutritional status (13,14) khan in 2006 found that children who are within the standard range of height and weight show normal eruption time as compared to those who are below the average (15).in a study for the eruption time of permanent teeth in pakistani children ;the eruption of the teeth is found to be positively related to somatic growth (height and weight) of individuals (16).the application of epidemiological methods as a research tool and knowledge about the procedures used for computing the times of permanent teeth emergence from cross-sectional data are necessary to produce a standard tables of teeth emergence time for each population (17) .various statistical procedures have been used for the analysis of data on teeth emergence time, which is usually being expressed as the arithmetic means by using j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 135 karber’s method (18,19), or using probit’s analysis (10-12),probit analysis is widely used for computing the median (50th percentile), the 5th and 95th percentiles range of tooth emergence because the use of fixed values often create the impression of delay or acceleration in emergence while presentation of ranges of normal variation would create more realistic picture for dental practice and /or for teaching(20). in iraq, studies conducted by al-farhan in1976, ghose and baghdady in 1981, ghaib in1998 and daood in 2001(19,21-23), this research is directed towards getting recent records of emergence of all individual permanent teeth except third molars (central incisors, lateral incisors, canines, first premolars, second premolars, first molars and second molars) for iraqi students which resides in basrah city by using precise statistical analysis (probit models) and compare the results with those of previous iraqi studies to evaluate the extent to which alteration in emergence times of permanent teeth might be expected, and to show the influence of nutrition on human dentition because there is no previous iraqi study concerning the relation between nutritional status and teeth eruption for permanent teeth . adequate knowledge of timing of permanent tooth emergence is essential for diagnosis and treatment planning in pediatric dentistry and orthodontics, the information on tooth emergence is also used to supplement other maturity indicators in the diagnosis of certain growth disturbances; therefore, the specific standards of the time of emergence of teeth considers as an important resource for general dental practitioners, orthodontists and pedodontist (24). materials and methods the investigation based on cross-sectional samples (25,26) gathered randomly from basrah city in the south part of iraq, the sample size in this study consists of 1807 children and teenaged from kindergarten, primary and secondary school children, the sample size was estimated after consultation with statistician based on the number of children present in the kindergarten, primary and secondary schools according to ministry of education census in 2014-2015, also the time available for conducting the study was determined, taking in consideration that a large sample can produce unbiased estimate for permanent teeth emergence times (26). in order to obtain representative sample the process of random sampling, according to which every member of a population has an equal chance of being included in the sample used (27). the examination of children and teenaged started from the first of november -2014 to the middle of april -2015. the examination after the achievement of the approval from the ministry of education to conduct this study, the school authority has been contacted and purposes of the study were explained to them, a child included in the examination if he or she regarded as iraqi as determined by the race of his parents. students were examined in their class room, they were seated in a chair with a tall back near the window to use the natural light in the examination while the examiner standing in front of the chair (28), and the records were written in the case sheet. accurate birthday was available from the school registrant (personal school chart for each child)and sometimes births supported by birth certificates, if the exact date of child’s birth was not available or has any orthodontic appliance, the child not included in the examination. the criteria used:  the teeth were recorded in the case sheet as emerged or not emerged. a tooth was defined as emerged when any part of its crown pierced the gingiva, the probe was used to be sure from crown emergence when any suspension exist (29-31,12).  any extracted permanent teeth were recorded as erupted (32).  since no radiographical examination was made, any congenital missing tooth was recorded as non-emerged (31). nutritional status assessment (anthropometric measurements) measurement of weight the measurement of weight was done by using scale for weight records nearest to 0.1 kg. the child weighted with minimum clothes without touching anything with 500 gram subtracted from the total weight to compensate for underneath clothes (9). measurement of height: the measurements of height was done by using the ordinary measuring tape fixed at the wall and the child standing up after removing the shoes with feet parallel to each other and pointed forward and the back is straight in upright position. the knees must be straight and the head in position that frankfort plane must be horizontal (33). j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 136 classification of malnutrition indices used for the purpose of assessment of nutritional status were: weight for age, height for age and weight for height; each was considered as in term of standard deviation score (z – score) as primary indicator of underweight ,stunting and wasting respectively ,these computed by percentile, and analyzed with -z score lines on the growth charts are numbered positively (1, 2, 3) or negatively (-1, -2, -3). in general, the plotted point that is far from the median in either direction close to the 3 or -3 zscore line may stand for a growth problem; indicators are included in a certain definition by being plotted above or below a particular z-score line. if it is plotted closely on the z-score line, it is considered in the less severe groupusing cut–off point -2 standard deviations. analysis procedure in this study, the emergence ages of permanent teeth agreed to be normally distributed which is the prerequisite of using probit analysis assuming and underlying normal distribution, so probit model employing the method of maximum likelihood was chosen after obtaining more information around calculation and equation arrangement for probit model (20). statistical significance of differences in mean of a normally distributed variable (nutritional indices z score) between 2 groups was assessed by independent samples t-test. the statistical significance of differences in mean of a normally distributed variable between more than 2 groups was assessed by anova test .the chi-square (χ2) pearson test was used to assess the statistical significance of association between 2 nominal or ordinal level variables results the total sample consisted of 1807 children and teenaged between ages (4-15) years, 766 of the sample were boys (42.4%) and 1041 were girls (57 .6%) collected from random areas of basrah city tables (1) and (2). the first tooth to erupt is the mandibular first molar and the last tooth is maxillary second molar. table (3) showed median eruption time (in years and months) for each permanent tooth stratified by gender. the results show greatest significant differences with earlier girls median eruption time than boys in the maxillary central incisor and mandibular canine (7 months) at p < 0.05. reverse relationship with (1 month) earlier median eruption time in boys than girls found in the second molar tooth but the results are statistically not significant. the smallest gender differences occurred in eruption of the maxillary second premolar (1month). most mandibular teeth (central incisor, lateral incisor, canine, first molar, second molar) emerged significantly earlier than opposing maxillary teeth for both genders (p < 0.05). this trend is reversed with premolar emergence time, the maxillary first premolar emerge significantly (3 months) for girls and (4 months) for boys before their mandibular antagonist. the greatest difference in the eruption time between the jaws for any individual tooth type occurred between the maxillary and mandibular canines of the boys [1(6/12) months] and between maxillary and mandibular canines of the girls [1 (9/12) months] the smallest difference in eruption time between the teeth of opposite jaws occurred with the eruption of the maxillary and mandibular first molar teeth in boys [(-1/12) months] and the maxillary and mandibular second premolar teeth in girls [(1/12) months]. the prevalence of sever stunting among children and teenagers were found to be 1.9% , the presence of stunting was significantly higher in girls (11.2 %) than in boys (6.7%). the distribution of sample according to weight for age z-score indicator found prevalence of 3.7% underweight, and 0.4 % sever underweight ,the percentage of underweight was higher in girls(4.9%)than in boys (3.1%)but the result was not statistically significant . wasting malnutrition was severe in 1.6% of sample and 1.5% of sample showed some degree of wasting, the percentage of wasted boys was higher than girls but the result was not statistically significant. among well-nourished children and teenaged most teeth were significantly erupted earlier than stunted children except the lateral incisor which erupted (1 month) earlier in stunted boys than well-nourished boys but the result was not significantly accepted (table 5). the greatest difference of median eruption age of permanent teeth in females between well nourished and stunted girls was in second molar tooth [1 (1/12 )months] , while in boys the greatest difference of median eruption age of permanent teeth between well -nourished and stunted boys was in the second molar tooth [1 (0/12)months ]. the greatest relative median potency estimates of mandible to maxilla between well-nourished and stunted boys was in the first premolar tooth (1.037) and the result was statistically significant (p<0.05). j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 137 table 1: distribution of sample by gender table 2: distribution of sample by age groups age group (years) no. % 4-6 370 20.5 7-9 521 28.8 10-12 461 25.5 13-15 455 25.2 total 1807 100 table 3: median eruption time (in years and months) for each permanent tooth stratified by gender table 4: prevalence of malnutrition according to gender gender n % boys 766 42.4 girls 1041 57.6 total 1807 100.0 arch tooth girls boys median eruption age (in years and months) median eruption age (in years and months) m a x illa central incisor 6 (11/12) 7 (6/12) lateral incisor 7 (11/12) 8 (3/12) canine 11 (1/12) 11 (6/12) first premolar 9 (8/12) 9 (11/12) second premolar 10 (10/12) 10 (11/12) first molar 6 (3/12) 6 (6/12) second molar 12 (2/12) 12 (1/12) m a n d ib le mandible central incisor 6 (1/12) 6 (6/12) lateral incisor 7 (1/12) 7 (5/12) canine 9(5/12) 10 (0/12) first premolar 9 (11/12) 10 (4/12) second premolar 10 (11/12) 11 (3/12) first molar 6 (1/12) 6 (6/12) second molar 11 (6/12) 11 (3/12) malnutrition gender p boys (n=766) girls (n=1041) n % n % stunting 51 6.7 117 11.2 p<0.001* underweight 24 3.1 51 4.9 0.06[ns] wasting 25 3.3 20 1.9 0.07[ns] any evidence of malnutrition 82 10.7 142 13.6 0.06[ns] j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 138 table 5: difference in median eruption time between stunted and acceptable height for age with relative median potency of mandible to maxilla according to gender median eruption age relative median potency estimates of mandible to maxilla significance acceptable haz¥ stunted difference estimate 95% ci central incisor girls 6.47 6.63 (2/12) 0.899 (0.861 to 0.936) p<0.05 * boys 6.90 7.54 (8/12) 0.88 (0.837 to 0.919) p<0.05 * lateral incisor girls 7.41 7.86 (5/12) 0.899 (0.878 to 0.918) p<0.05 * boys 7.78 7.66 (-1/12) º 0.898 (0.161 to 1.116) [ns] canine girls 10.11 10.76 (8/12) 0.85 (0.823 to 0.866) p<0.05 * boys 10.60 11.17 (7/12) 0.876 (0.85 to 0.9) p<0.05 * first premolar girls 9.68 10.05 (4/12) 1.026 (1.009 to 1.045) p<0.05 * boys 10.01 10.90 (11/12) 1.037 (1.015 to 1.061) p<0.05 * second premolar girls 10.76 11.59 (10/12) 1.012 (0.996 to 1.028) [ns] boys 10.96 11.97 1 (0/12) 1.031 (1.012 to 1.051) p<0.05 * first molar girls 6.10 6.38 (3/12) 0.967 (0.946 to 0.987) p<0.05 * boys 6.53 7.37 (10/12) 0.97 (0.928 to 1.012) [ns] second molar girls 11.65 12.80 1 (2/12) 0.951 (0.935 to 0.965) p<0.05 * boys 11.90 12.51 (7/12) 0.949 (0.93 to 0.967) p<0.05 * * significant at p< 0.05, º negative symbol indicates reverse relationship, ¥ haz :height for age z-score discussion in the current study, the age range of examined children was chosen in wide scale ranging from 4 to 15 years in order to cover the clinical emergence ages of both maxillary and mandibular permanent teeth except third molar because they have great variability in development, emergence, and time of occlusion (34). a cross-sectional study was designed because the desired emphasis was on the accuracy of emergence dates of permanent teeth (26), and an attempt to include a greater sample size in order to get sufficient unbiased estimates for the median emergence time using proper statistical method. the emergence times of the permanent teeth in the right and left sides in both jaws and for each gender have no statistical significant differences and this result in agreement with studies of helm and seidler (29), elkeli et al (12) and daood (23). this similarity in permanent teeth eruption in right and left sides indicate a more stability in the permanent dentition development (35), the timing of emergence of permanent teeth in the present study show differencesin comparison with other asian study kanno (17) which conducted for japanese children especially for canines and premolars.. the emergence time for iraqi children in the present study found to be earlier when compared with saudian children for the emergence of canine and premolars (5),some of differences could be attributed to differences in sample size or variation in the environmental factors ,other differences may be related to racial variations. the results of the present study show that the mandibular teeth emerge significantly (p < 0.05) earlier than corresponding maxillary teeth in both genders except for premolars, these results are in agreement with the study of el –sawaf in egypt (36), kanno in japan (17) .on the other hand the results of the present study disagree with the study of el– zahid and hafez (5) in saudi who found that the maxillary and mandibular premolars have almost the same time of emergence especially for the boys. the greatest difference in the eruption time between the jaws for any individual tooth type occurred between the maxillary and mandibular canines in the boys [1(6/12) months] and between maxillary and mandibular canines in the girls [1 (9/12) months]. the smallest difference in eruption time between the teeth of opposite jaws occurred with the eruption of the maxillary and mandibular first molar teeth in boys [(-1/12) months] and the maxillary and mandibular second premolar teeth in girls [(1/12) months]. the variation of emergence for maxillary canine could be attributed to its long and tortuous path of eruption during its development, and this j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 139 variation in timing of canine eruption should be considered along with its possible effect on the alignment with the other maxillary teeth (37), less variability reported for the first molar which have no deciduous predecessors behind the second deciduous molar, as these teeth emerge they are guided the first molar into its position in the oral cavity (38) . in general the advancement of mandibular permanent teeth in their emergence than corresponding maxillary permanent teeth could be attributed to the earlier formation of mandible during its embryonic development than maxilla (39), therefore the mandibular teeth expected to form and emerge before the maxillary teeth, while the emergence of maxillary premolars before the mandibular premolars in the present study could be due to the local factors. gender differences could be explained by the fact that girls exhibit earlier physical development than boys, also the girls permanent teeth found to have a complete root formation earlier than boys permanent teeth (31,40). the emergence of permanent teeth for iraqi children in both genders began with the appearance of mandibular first molar in and ended by emergence of maxillary second molar. during permanent dentition development ,the mandibular first molar have rapid rate of formation (formation of enamel matrix and dentin begins at birth and enamel completed at 2-3 years), while the maxillary second molar start its calcification about 2-3 years and completion of crown occurs about 7-8 years (38). the general trends of permanent teeth emergence in this research are similar to those of previous iraqi studies (19,21-23). the differences between the life style nowadays and a few decades ago, including the texture of food, the general health care and other external factors that may lead to changes in the development of human dentitions as a whole. so the demonstrated differences in the emergence pattern between the sample of 1976 and 2014 could be interpreted to represent a trends in the emergence of permanent dentition and these changes may be associated with a different relations between timing of dental and general development in the earlier and cotemporary generations or due to genetic variations (8). the results of permanent teeth emergence times (except third molar) in this research are approximately the same for those reported by ghose and baghdady (21) and daood (23), but earlier than those reported by ghaib (22). but the precise comparison is difficult to done because only years of child birth was used without consideration of any month intervals except study done by daood (23) by collecting the samples from baghdad city and the researcher used a statistical method (probit analysis) differ than karber method used in previous iraqi studies, the karber method gives a later estimate for the emergence times in such situation. therefore, the permanent teeth emergence remain as an example of growth parameter and both earlier and later emergence of permanent teeth emergence in both genders which found in the present research compared with previous iraqi studies could be in general reflect variations during the stages of teeth formation. in the present study the prevalence malnutrition according to height for age, weight for age , and weight for height nutritional status indicators were found to be 7.4 %, 3.7 % and 1.5% respectively .the comparison of malnutrition of present study with other studies is difficult because of using of different criteria in classification of malnutrition or different age ranges of sample. the prevalence of chronic malnutrition (stunting) was found to be higher than the prevalence of underweighting and wasting malnutrition, with more prevalence among girls than boys, the higher prevalence of stunting among younger girls children could be due to the effect of extension of cultural preference for boys (41). some children have more than one type of malnutrition status, this combines information about linear growth retardation, as wasting and stunting are varying only in terms of timing or intensity, and all three malnutrition status (stunting, wasting and underweight) share some common causes as dietary inadequacy. the present study revealed that there were significant differences in the eruption time of permanent teeth among well-nourished and stunted with an earlier eruption of permanent teeth in wellnourished children and teenaged in both genders. among well-nourished children and teenaged described by height for age nutritional status indicator, most teeth were significantly erupted earlier than stunted children except the lateral incisor which erupted earlier in stunted boys than well-nourished boys but the result was not significantly accepted. the greatest difference of median eruption age of permanent teeth between well -nourished and stunted found in girls in the second molar tooth which was [1 (2/12)months] , eruption of teeth is a growth process of the body and therefore have a relation with other processes of the body especially height and weight (42). references 1. almonaitiene r, balciuniene i, tutkuviene j. factors influencing permanent teeth eruption. part one–general factors. stomatologija 2010; 12(3): 67-72. j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 140 2. parkash h, mathur v p, duggal r, jhuraney b. dental workforce issues: a global concern. j dental education 2006; 70(11 suppl): 22-6. 3. moyers re. handbook of orthodontics. 4th ed. chicago yearbook. med publish inc.; 1988. pp. 140. 4. hagg u, taranger j. timing of tooth emergence. swed dent j 1986; 10: 195-206. 5. el-zahid h, hafez s. sequence of eruption of maxillary and mandibular permanent canines and premolars for a group of saudi children. egyptian orthod j 1993; (7): 321-7. 6. pytlik w. primary failure of eruption; a case report. int dent j 1991; 41(5): 274-8. 7. rasmussen p, kotaski .inherited primary failure of eruption in the primary dentition. j dent child 1997; 64 (1): 43-7. 8. alvarez jo. nutrition, tooth development, and dental caries. am j clinical nutrition1995; 61(2): 410s-6s. 9. diab bs. nutritional status in relation to oral health condition among 6-10 years primary school children in the middle region of iraq. ph.d. thesis, college of dentistry, university of baghdad, 2003. 10. blankenstein r, cleaton-jones pe, maistry pk, luk k m, fatti lp. the onset of eruption of permanent teeth amongst south african indian children. annals of human biology, 1990; 17(6): 515-21. 11. virtanen ji, bloigu rs, larmas ma. timing of eruption of permanent teeth: standard finnish patient documents. comm. dent. oral. epidemiol 1994; 22: 286-8. 12. eskeli r, laine mt, hasen h. standard for permanent teeth emergence in finnish children. angle orthod 1999; 69(6): 529-33. 13. billewicz wz, mcgregor ia. eruption of permanent teeth in west african (gambian) children in relation to age, sex and physique. ann hum biol 1975; 2: 17-28. 14. diamanti j. townsend gc. new standards for permanent tooth emergence in australian children. australian dent j 2003; 48(1): 39-42. 15. khan nb, chohan an, al-mograbi b, al-deyab s, zahid t, al-moutairi, m. eruption time of permanent first molars and incisors among a sample of saudi male schoolchildren. saudi dent j 2006; 18(1): 18-24. 16. khan n. eruption time of permanent teeth in pakistani children. iranian j public health 2011; 40(4): 63. 17. kanno r. estimation of median for the eruption time of permanent teeth. memories liberal arts sciences 1995; 11: 6-17. 18. krumholt l, petersen b, pindborg jj .eruption times of the permanent teeth in 622 ugandan children. archs oral biol 1971; 16: 1281-8. 19. al-farhan s. aspects of oral health in iraq. a mater thesis, university of dundee, 1979. 20. kanno r. on the linearization of eruption series of the permanent teeth. the bulletin of tokyo dental college 1997; 38(4): 269-281. 21. ghose lj, baghdady vs. eruption time of permanent teeth in iraqi school children. arch oral biol 1981; 26(1): 13-15. 22. ghaib n. eruption time permanent teeth iraqi school children. j coll dentistry 2002; 12: 94-7. 23. daood zh. chronology of permanent teeth emergence for iraqi children /baghdad city (across-sectional study). a master thesis, college of dentistry; university of baghdad, 2001. 24. mugonzibwa ea, kuijpers am, laine mt, van‘t hof ma. emergence of permanent teeth in tanzanian children. community dentistry oral epidemiol 2002; 30(6): 455-462. 25. dahlberg aa, menegaz-bock rm. emergence of permanent teeth in pima india children. j dent res.1958; 37:1123-40. 26. holman dj, jones re. longitudinal analysis of deciduous tooth emergence: ii. parametric survival analysis in bangladeshi, guatemalan, japanese, and javanese children. am j phys anthropol 1998; 105(2): 209-30. 27. spiegel mr. statistics-theory and problem. london: mcgraw-hill book co.; 1972. pp. 188-195. 28. world health organization. oral health surveys basic methods. 4th ed. who. geneva; switzerland, 1997. 29. helm s, seidler b. timing of permanent tooth emergence in danish children. comm dent oral epidemiol 1974; 2: 122-9. 30. boesen p, haven j, helm s .timing of permanent tooth emergence in two greenland eskimo population. community dent oral epidemiol 1967; 4: 244-7. 31. jaswal s. age and sequence of permanent tooth emergence among khasis. am j phys anthropol1983; 62: 177-186. 32. world health organization. basic methods for oral health survey. 3rd ed. who. geneva, 1987. 33. buckler jm. variations in height throughout the day. arch disease childhood 1978; 53: 762. 34. proffit wr, fields hw. contemporary orthodontics. 3rd ed. st. louis: mosby inc.; 2000. 35. mayhall jt, belier pl, mayhall mf. canadian eskimo permanent tooth emergence timing. am j phys anthropol 1978; 49: 211-16. 36. el-sawaf aa. chronology of permanent teeth emergence among a group of egyptian children. a mater thesis, faculty of oral and dental medicine, cairo university, 1985. 37. dean ja, avery dr, mcdonald re. mcdonald and avery's. dentistry for the child and adolescent. 9th ed. missouri: mosby/elsevier; 2011. pp: 190-200. 38. scott j h, symons n b. introduction to dental anatomy. 9th ed. churchill livingston; 1961. pp: 103-133. 39. brash jc. the growth of the alveolar bone and its relation to the movements of the teeth, including eruption. inter j orthodontia oral surgery and radiography 1991; 14(6): 487-504. 40. farah me. the orthodontic examination of children aged 9 and 10 years from baghdad, iraq-a clinical and radiographic study. a master thesis. college of dentistry, university of baghdad.1988. 41. senbanjo io, oshikoya ka, odusanya oo, njokanma of. prevalence of and risk factors for stunting among school children and adolescents in abeokuta, southwest nigeria. j health population nutrition 2011; 29(4): 364. 42. jones pc, richardson bd, granath l, fatti l p, sinwell r, walker a r, mogotsi m. nutritional status and dental caries in a large sample of south african children. south african medical journal-cape town-medical association of south africa 2000; 90(8; supp/2): 80-3. thair f.docx j bagh college dentistry vol. 28(2), june 2016 a comparative study oral and maxillofacial surgery and periodontics 92 a comparative study between flapped and flapless surgical techniques in dental implant stability according to resonance frequency analysis ali f. hassan, b.d.s. (1) thair abdul-lateef, b.d.s., h.d.d., f.i.b.m.s. (2) abstract background: recent implant surgical approach aims to cause less trauma, invasiveness and pain as much as possible and to reduce patient and surgeon discomfort, time of surgery and time needed for functional implant loading. flapless surgical techniques considered recently as one of the most popular techniques that may achieve these aims especially enhancing osseointegration and subsequently implant stability within less time than the traditional flapped surgical technique. so this study aimed to make a comparison between flapped and flapless surgical techniques in resulted implant stability according to resonance frequency analysis rfa and in duration of surgical operation. materials and methods: a total of 26 patients with 41 implants (one implant in the study group failed so it was excluded from the statistical analysis) were randomized into two groups: control group which involved 20 implants inserted by conventional flapped surgical approach and study group which involved 20 implants inserted by flapless surgical approach. estimation of alveolar bone was done for study group by bone (ridge) mapping procedure. duration of surgical operation for each implant, implant stability was measured at three time intervals (at surgery, two months and three months after surgery). results: after three months interval of surgery the mean implant stability of the study (flapless) group achieved significant higher implant stability than control (flapped) group (p< 0.05) and the difference in measured implant stability was (5.05) implant stability quotient(isq). the time of surgical operation for implants in the study group significantly was less than that of control group (p< 0.01). conclusions: implants placed with flapless surgical technique can produce high implant stability in shorter time and consume prominently shorter time for surgical operation compared to those placed with conventional flapped technique. key words: flapless technique, implant stability, resonance frequency analysis, implant stability quotient. (j bagh coll dentistry 2016; 28(2):92-97). introduction dental implant is a recent science. this science is continuously developing from its beginning on nineteenth century till now. one aspect of that development was the surgical procedure. when dental implant science saw the light the classical surgical procedure involved the incision of mucosa and reflection of the flap then exposing the bone, finally placing the implant and suturing back the flap (1,2). this procedure had some disadvantages, one of them crestal bone resoption and this may affect implant future outcome and stability (3). reflection of flap was not needed in flapless surgery since the implant placed in bone through mucosa by minimal incision or by making a window through mucosa by tissue punch(4). dental implant placement by flapless surgery is becoming more popular among surgeons. it has many benefits as preservation of the original mucosal form around implant (5), decreasing the resoption of bone at the site of operation (6), maintenance of the blood supply around the implant (7),in addition to decrease patient discomfort and decrease the time of operation (8). (1) master student. department of oral and maxillofacial surgery. college of dentistry, university of baghdad. (2) assistant professor. department of oral and maxillofacial surgery. college of dentistry, university of baghdad. the flapless procedure is first introduced by lederman in 1977 (9). campelo and camara in 2002 performed a retrospective study over 10 years, which involved 770 implants placed by flapless procedure. the success rate was 74.1% for cases between 1990 and 2000. since the changes and technological advancements made in the surface of the various implants used in the procedure as well as the implants shapes, a complete success was achieved after 2000(10). there are no differences in perforation or dehiscence of the crestal bone by either novice or professional dentists as a study employed in 2006 by ghent university .this study also showed the flapless technique was more reliable and easy to use and it concluded that the procedural success of implant depend on the good knowledge about the anatomy and structure of bone (11). one of the most important advantages of flapless procedure is enhancing implant stability. jeong et al. in 2011 stated that implant stability was not decreasing initially after placement of implant by flapless procedure. they found that stability increased after 2 weeks of placement, while it is normally decreasing at this time for the conventional flapped procedure(12). since it is very important to confirm this suggestion and to show the effect of flapless surgery on both initial and j bagh college dentistry vol. 28(2), june 2016 a comparative study oral and maxillofacial surgery and periodontics 93 secondary stability of implants, further research should be applied using recent tools for measurement of stability. a noninvasive and simple method with accurate quantitative measure of implant stability is resonance frequency analysis (rfa) (13). the development of this device over last years led to production of a device better than other implant stability measurement devices like periotest(14,15). considering the advantages and disadvantages of each type of surgical techniques and the limited number of studies on that field, it would be appropriate to study the effect of two techniques on implant stability for appropriate period of time to conclude which method better in this aspect. this study aimed to measure the implant stability by means of osstelltm according to rfa on three months follow up. the working hypothesis is that using flapless technique leads to better implant stability and to calculate the duration of surgical procedure for each implant placement and compare it between flapped and flapless techniques. materials and methods this study was taken place in the implantology unit of the department of oral and maxillofacial surgery, dental college teaching hospital, baghdad university, iraq, from december 2013 to december 2014. patient sample it included 26 patients with 41 implants (one implant in study group failed so it is excluded from the statistical analysis except in the analysis of survival and failure rates). there are 10 male patients with 14 implants and 16 female patients with 26 implants. the whole sample was divided into: 1flapped group (control): which consisted of 20 implants placed with classical flap procedure, 8 implants placed in 6 male patients and 12 implant placed in 8 female patients. 2flapless group (study): which consisted of 20 implants placed with flapless procedure, 6 implants placed in 4 male patients and 14 implants in 8 female patients. an informed consent was procured from all patients before starting the treatment. patients were followed up to 3 months after surgery. inclusion criteria 1good oral hygiene. 2implants to be placed at least 6 months after teeth extraction. 3presence of at least 2 mm keratinized tissue above the crest of bone in the area receiving the implant, as measured by needle and stopper. 4available bone width is at least 5 mm, 3 mm apical to crest measured by bone caliper after measurement of soft tissue above the crest. 5patients ≥ the age of 18 years. exclusion criteria 1insufficient keratinized tissue above the implant site (less than 2 mm above the ridge crest). 2insufficient bone width (less than 5 mm, 3 mm apical to crest). 3subantral bone height less than 8 mm. 4presence of any pathological condition in or adjacent proposed implant site. 5any systemic chronic disease (uncontrolled diabetes, uncontrolled hypertension, osteoporosis or any other conditions have a direct effect on bone healing). 6pregnant or lactating females. 7any dehiscence or fenestration of alveolar bone happened during the operation of implant placement. implant systems: two implants systems were utilized in the study (implantium® / dentium® / seoul / korea) and (nucleoss®/ turkey) with a property of surface modified by tio2-large grit sandblasting and acid etched surface.the diameter of ø3.4 mm, ø3.8 mm ø4.3 mm or ø4.8 mm and a length of 8mm, 10mm, 12mm or 14mm were used in the study. preoperative clinical and radiologicalexamination detailed previous medical and dental histories were taken from each patient by a special forma of a case sheet for the implant center and special case sheet for this study. orthopantomogram opg view was made for each patient. bone mapping procedure this step was done just for patients of the study group, it depended on a bone mapping procedure that help in measuring bucco-lingual dimension and avoiding unnecessary radiation of computed tomography. this procedure was done as following: j bagj bagh college dentistry oral and maxillofacial surgery and periodontics 1localization of certain points in patient mouth the points were shown in (fig fig.1: localization of points in the patient 2an impression is taken to the jaw of the patient that the implants were planned to be placed by alginate and is poured immediately to prevent dimensional changes. the done points were printed exactly to the alginate and then to the cast. 3then patient cleaned his mouth by tap water and then around these points and the measurement procedure of mucosa thickness at these localized points was done by needle and stopper (fig fig. 2: measurement of thickness of mucosa 4then the vacuum former 5the cast was cut at the site of points about 1 mm away from points using disking burs of 0.6 mm thickness. the resulted end of the ridge was trimmed out according to the measurement of soft tissue that was localized by the points on the ridge (fig h college dentistry oral and maxillofacial surgery and periodontics localization of certain points in patient mouth the points were made by copying pencil as shown in (fig.1). fig.1: localization of points in the patient mouth. an impression is taken to the jaw of the patient that the implants were planned to be placed by alginate and is poured immediately to prevent dimensional changes. the done points were printed exactly to the alginate and then to the cast. then patient cleaned his mouth by tap water and then local anesthesia was given to the tissue around these points and the measurement procedure of mucosa thickness at these localized points was done by needle and stopper (fig 2: measurement of thickness of mucosa then the surgical stent was fabricated by using vacuum former. the cast was cut at the site of points about 1 mm away from points using disking burs of 0.6 mm thickness. the resulted end of the ridge was trimmed out according to the measurement of soft tissue that was obtained by needle and stopper and was localized by the points on the ridge (fig h college dentistry oral and maxillofacial surgery and periodontics localization of certain points in patient mouth made by copying pencil as fig.1: localization of points in the patient mouth. an impression is taken to the jaw of the patient that the implants were planned to be placed by alginate and is poured immediately to prevent dimensional changes. the done points were printed exactly to the alginate and then to the cast. then patient cleaned his mouth by tap water local anesthesia was given to the tissue around these points and the measurement procedure of mucosa thickness at these localized points was done by needle and stopper (fig 2: measurement of thickness of mucosa surgical stent was fabricated by using the cast was cut at the site of points about 1 mm away from points using disking burs of 0.6 mm thickness. the resulted end of the ridge was trimmed out according to the measurement of soft was obtained by needle and stopper and was localized by the points on the ridge (fig h college dentistry vol. 2 oral and maxillofacial surgery and periodontics localization of certain points in patient mouth made by copying pencil as fig.1: localization of points in the patient an impression is taken to the jaw of the patient that the implants were planned to be placed by alginate and is poured immediately to prevent dimensional changes. the done points were printed exactly to the alginate and then to the cast. then patient cleaned his mouth by tap water local anesthesia was given to the tissue around these points and the measurement procedure of mucosa thickness at these localized points was done by needle and stopper (fig. 2). 2: measurement of thickness of mucosa surgical stent was fabricated by using the cast was cut at the site of points about 1 mm away from points using disking burs of 0.6 mm thickness. the resulted end of the ridge was trimmed out according to the measurement of soft was obtained by needle and stopper and was localized by the points on the ridge (fig. 3) vol. 28(2), june oral and maxillofacial surgery and periodontics 94 localization of certain points in patient mouth. made by copying pencil as fig.1: localization of points in the patient an impression is taken to the jaw of the patient that the implants were planned to be placed by alginate and is poured immediately to prevent dimensional changes. the done points were printed exactly to the alginate and then to the cast. then patient cleaned his mouth by tap water local anesthesia was given to the tissue around these points and the measurement procedure of mucosa thickness at these localized . 2: measurement of thickness of mucosa. surgical stent was fabricated by using the cast was cut at the site of points about 1 mm away from points using disking burs of 0.6 mm thickness. the resulted end of the ridge was trimmed out according to the measurement of soft was obtained by needle and stopper and . 3). fig. 6-the exact drilling point was placed on the surgical stent depending on the resulted ridge which covering keratinized tissue surgical procedure groups implanted. flap design was using conventional drilling procedure associated system appropriate driven in bone manually in the prepared hole and the stability was measured imme test utilizing suturing was done by 3/0 braided black silk suture (fig incision to the end of the last suture and the time of original time procedure was done except tissue punch was used to expose bony bed and finally stability was june 2016 94 fig. 3: ridge (bone) mapping on the cast. the exact drilling point was placed on the surgical stent depending on the resulted ridge which represented the direct bone without the covering keratinized tissue surgical procedure the implant groups with locally anesthetizing the area to be implanted. for flapped (control) group, flap design was the bony bedwas using conventional drilling procedure associated system appropriate size. driven in bone manually in the prepared hole and the stability was measured imme test utilizingosstelltm with its smart pegs. finally the cover screw was placed and suturing was done by 3/0 braided black silk suture (fig. 4).the time of procedure calculated from the incision to the end of the last suture and the time of measuring stability was subtracted from the original time fig. 4: placement of the cover screws on for flapless (study) group same surgical procedure was done except tissue punch was used to expose bony bed and finally stability was 6 3: ridge (bone) mapping on the cast. the exact drilling point was placed on the surgical stent depending on the resulted ridge represented the direct bone without the covering keratinized tissue. surgical procedure implant surgery was with locally anesthetizing the area to be for flapped (control) group, flap design was made. bony bedwas exposed and prepared using conventional drilling procedure associated system in sequence until reaching size.the specified dental implant was driven in bone manually in the prepared hole and the stability was measured imme osstelltm with its smart pegs. finally the cover screw was placed and suturing was done by 3/0 braided black silk suture the time of procedure calculated from the incision to the end of the last suture and the time measuring stability was subtracted from the 4: placement of the cover screws on dental implants. for flapless (study) group same surgical procedure was done except tissue punch was used to expose bony bed and finally stability was a comparative study 3: ridge (bone) mapping on the cast. the exact drilling point was placed on the surgical stent depending on the resulted ridge represented the direct bone without the surgery was began for both with locally anesthetizing the area to be for flapped (control) group, exposed and prepared using conventional drilling procedure in sequence until reaching the specified dental implant was driven in bone manually in the prepared hole and the stability was measured immediately by rfa osstelltm with its smart pegs. finally the cover screw was placed and suturing was done by 3/0 braided black silk suture the time of procedure calculated from the incision to the end of the last suture and the time measuring stability was subtracted from the 4: placement of the cover screws on dental implants. for flapless (study) group same surgical procedure was done except tissue punch was used to expose bony bed and finally stability was a comparative study 3: ridge (bone) mapping on the cast. the exact drilling point was placed on the surgical stent depending on the resulted ridge represented the direct bone without the began for both with locally anesthetizing the area to be extensive exposed and prepared using conventional drilling procedure of the in sequence until reaching an the specified dental implant was driven in bone manually in the prepared hole and diately by rfa osstelltm with its smart pegs. finally the cover screw was placed and suturing was done by 3/0 braided black silk suture the time of procedure calculated from the incision to the end of the last suture and the time measuring stability was subtracted from the 4: placement of the cover screws on for flapless (study) group same surgical procedure was done except tissue punch was used to expose bony bed and finally stability was a comparative study j bagj bagh college dentistry oral and maxillofacial surgery and periodontics measured by healing and no need for sutures fig procedure was calculated from the application of the punch to the end of placing the gingival former, time of measuring stability was subtracted from the original time. fig. technique with data collection and follow up data were collected first at the day of operation immediately after implant placement by measuring the stability from two directions of implant (buccolingually and mesiodistally). after that all patients were informed to come back for follow up after two and three months respectively. after two months for control group (flap procedure) surgical exposure for the implant was done for each implant by using tissue punch (dentium, korea) and gingival f while for the study group just releasing the gingival former was enough for each one statistical analysis statistical analysis was performed in this study using spss (statistical package for social science; version 17) program. independent was used to estimate differences between two groups in continuous variables. also paired t was used to assess the statistical significance of change in mean after each successive interval of time compared to a previous time station in same patients. results for with rate study group with survival statistically according to rfa analysis the result showed: for baseline interval significant difference between both groups h college dentistry oral and maxillofacial surgery and periodontics measured by rfa test utilizing osstelltm healing abutment (gingival former) was placed and no need for sutures fig procedure was calculated from the application of the punch to the end of placing the gingival former, time of measuring stability was subtracted from the original time. fig. 5: implants placed with flapless technique with their gingival formers. data collection and follow up data were collected first at the day of operation immediately after implant placement by measuring the stability from two directions of implant (buccolingually and mesiodistally). after patients were informed to come back for follow up after two and three months respectively. after two months for control group (flap procedure) surgical exposure for the implant was done for each implant by using tissue punch (dentium, korea) and gingival f while for the study group just releasing the gingival former was enough for each one statistical analysis statistical analysis was performed in this study using spss (statistical package for social science; version 17) program. independent was used to estimate differences between two groups in continuous variables. also paired t was used to assess the statistical significance of change in mean after each successive interval of time compared to a previous time station in same results thecontrol group all implants survived rate 100% while one implant failed in the study group with survival statistically insignificant according to rfa analysis the result showed: baseline interval significant difference between both groups h college dentistry oral and maxillofacial surgery and periodontics rfa test utilizing osstelltm (gingival former) was placed and no need for sutures fig. (5 procedure was calculated from the application of the punch to the end of placing the gingival former, time of measuring stability was subtracted from the original time. 5: implants placed with flapless their gingival formers. data collection and follow up data were collected first at the day of operation immediately after implant placement by measuring the stability from two directions of implant (buccolingually and mesiodistally). after patients were informed to come back for follow up after two and three months respectively. after two months for control group (flap procedure) surgical exposure for the implant was done for each implant by using tissue punch (dentium, korea) and gingival f while for the study group just releasing the gingival former was enough for each one statistical analysis statistical analysis was performed in this study using spss (statistical package for social science; version 17) program. independent was used to estimate differences between two groups in continuous variables. also paired t was used to assess the statistical significance of change in mean after each successive interval of time compared to a previous time station in same group all implants survived % while one implant failed in the study group with survival rate insignificant difference (p> 0.05) according to rfa analysis the result showed: baseline interval (at surgery) significant difference between both groups h college dentistry vol. 2 oral and maxillofacial surgery and periodontics rfa test utilizing osstelltm then (gingival former) was placed 5). the time of procedure was calculated from the application of the punch to the end of placing the gingival former, time of measuring stability was subtracted 5: implants placed with flapless their gingival formers. data collection and follow up data were collected first at the day of operation immediately after implant placement by measuring the stability from two directions of implant (buccolingually and mesiodistally). after patients were informed to come back for follow up after two and three months respectively. after two months for control group (flap procedure) surgical exposure for the implant was done for each implant by using tissue punch (dentium, korea) and gingival former placed while for the study group just releasing the gingival former was enough for each one. statistical analysis was performed in this study using spss (statistical package for social science; version 17) program. independent twas used to estimate differences between two groups in continuous variables. also paired twas used to assess the statistical significance of change in mean after each successive interval of time compared to a previous time station in same group all implants survived % while one implant failed in the rate 95.23% with difference (p> 0.05). according to rfa analysis the result showed: (at surgery) there was no significant difference between both groups(p> vol. 28(2), june oral and maxillofacial surgery and periodontics 95 then (gingival former) was placed the time of procedure was calculated from the application of the punch to the end of placing the gingival former, time of measuring stability was subtracted data were collected first at the day of operation immediately after implant placement by measuring the stability from two directions of implant (buccolingually and mesiodistally). after patients were informed to come back for follow up after two and three months respectively. after two months for control group (flap procedure) surgical exposure for the implant was done for each implant by using tissue punch ormer placed while for the study group just releasing the statistical analysis was performed in this study using spss (statistical package for social -test was used to estimate differences between two -test was used to assess the statistical significance of change in mean after each successive interval of time compared to a previous time station in same group all implants survived % while one implant failed in the 95.23% with according to rfa analysis the result showed: there was no (p> 0.05) implant stability quotient ( cohen's effect measured and showed small difference difference increase between two groups with higher values for flapless (study) group insignificance applied and showed moderate difference between both group about (3.47) isq. months) the difference became significant 0.05) (5.05) isq flapless group higher than flapped one. these results illustrated in fig implants for both control and study groups. operation time difference between the time consumed in flapless and flap between the mean of these two groups were (13.09) min and this was illustrating that flapless procedure consumed much less time than flapped procedure as shown in fig ( fig.7: june 2016 95 0.05) with slight difference in mean about (0.53) implant stability quotient ( cohen's effect measured and showed small difference (0.085) for the next interval (after two months) the difference increase between two groups with higher values for flapless (study) group insignificance applied and showed moderate difference between both groups (0.45) about (3.47) isq. finally in the third interval (after three months) the difference became significant 0.05) with large cohen's effect (5.05) isq flapless group higher than flapped one. these results illustrated in fig fig. 6: the mean stability of the dental implants for both control and study groups. according to the duration of surgical operation time difference between the time consumed in flapless and flapped group between the mean of these two groups were (13.09) min and this was illustrating that flapless procedure consumed much less time than flapped procedure as shown in fig ( values are expressed in mean ± sd fig.7: time of surgical operation for both 6 with slight difference in mean about (0.53) implant stability quotient ( cohen's effect measured and showed small (0.085). xt interval (after two months) the difference increase between two groups with higher values for flapless (study) group insignificance (p> 0.05), again cohen's effect applied and showed moderate difference between s (0.45) with isq diff about (3.47) isq. finally in the third interval (after three months) the difference became significant with large cohen's effect (5.05) isq flapless group higher than flapped one. these results illustrated in fig 6: the mean stability of the dental implants for both control and study groups. according to the duration of surgical operation time there was difference between the time consumed in flapless groups (p< 0.01). the difference between the mean of these two groups were (13.09) min and this was illustrating that flapless procedure consumed much less time than flapped procedure as shown in fig (7 values are expressed in mean ± sd time of surgical operation for both groups. a comparative study with slight difference in mean about (0.53) implant stability quotient (isq) and further cohen's effect measured and showed small xt interval (after two months) the difference increase between two groups with higher values for flapless (study) group , again cohen's effect applied and showed moderate difference between with isq difference finally in the third interval (after three months) the difference became significant with large cohen's effect (0.95) and about (5.05) isq flapless group higher than flapped one. these results illustrated in fig. (6). 6: the mean stability of the dental implants for both control and study groups. according to the duration of surgical was high significance difference between the time consumed in flapless (p< 0.01). the difference between the mean of these two groups were (13.09) min and this was illustrating that flapless procedure consumed much less time than flapped 7). values are expressed in mean ± sd time of surgical operation for both s. a comparative study with slight difference in mean about (0.53) and further cohen's effect measured and showed small xt interval (after two months) the difference increase between two groups with higher values for flapless (study) group but still , again cohen's effect applied and showed moderate difference between erence in mean finally in the third interval (after three months) the difference became significant (p< and about (5.05) isq flapless group higher than flapped one. 6: the mean stability of the dental implants for both control and study groups. according to the duration of surgical high significance difference between the time consumed in flapless (p< 0.01). the difference between the mean of these two groups were (13.09) min and this was illustrating that flapless procedure consumed much less time than flapped values are expressed in mean ± sd time of surgical operation for both a comparative study j bagh college dentistry vol. 28(2), june 2016 a comparative study oral and maxillofacial surgery and periodontics 96 discussion some studies as this presented study depended on resonance frequency analysis concluded implant stability after implant placement with flapless surgical technique has significant advantages over the flapped technique (16). in contrast other authors preferred conventional procedure due to blindness of flapless one and some risky of hemorrhage and failure due to miss position of implant placed by flapless technique(17). according to this study, there was no significant difference between early success rate between control and study groups. the depended criteria in this study was presence or absence of mobility (observed clinically). this criteria considered one of the determinant of failure of dental implants as mentioned by albrektsson et al. in 1986 and zarb and albrektsson in 1998(18,19). depending on this there was one implant failed in the study group and there were no implants failed in control group. these findings coincided with previous studies were done on flapless technique which found no statistical significance difference between survival rate of flapless and flapped procedure for different intervals of time(20,21,22). also they concluded that flapless procedure was viable and predictable procedure. according to rfa analysis that done in this study implant placed by flapless technique expressed better stability than that placed by flapped one in three months period after surgery. results of this study could be explained by elevation of full thickness flap would be more traumatic on underlying bone causing postsurgical effect and may have an adverse reaction on the process of bone remodeling (this opinion confirmed also by glauser et al. in 2004(23)). also there were many experimental studies on animal done to evaluate the peri-implant tissues reaction to both flapless and flapped methods. a study was done in 2007 by jeong et al. on female mongrel dogs, who investigated the bone to implant contact (bic) and bone resorptionhistomorphometrically for both procedures. they found 60% bic and bone height 10 mm in implants placed with flapless procedure compared to 70% bic and bone height 9 mm in implants placed with flapped procedure(6). another study concluded that a flapless surgical method may preserve vasculature of the periimplant tissue more better than flapped surgical method with more distant appeared to be empty from any signs of inflammation (7). in addition to previous mentioned studies, a histological analysis of flapless implants revealed the junctional epithelium was situated 1-mm more cervical than flapped implants due to reduced crestal bone resorption around flapless implants (5). these result come in coordination with jeong et al. in 2011 who found better isq values for next 8 weeks after surgery between flap and flapless group in mongrel dogs(12). also vlahovic et al. in 2013 agreed with this study in comparison between both groups and found significant difference between both groups after three months periods(16). finally according to duration of surgical operation, it was obvious in this study the time for one implant placed with flapless procedure consumed less than that placed by flapped one.this resultmay be returned to the following reasons: • there was no flap elevation in flapless surgical procedure (this reduce time of incision, flap elevation and reflection during the whole time of surgery). • there was no need for suturing in flapless surgical procedure. • the flapless procedure was less invasive than the flapped one so there was less trauma to the soft and hard tissue and that was leading to less bleeding in the surgical field that resulted rationally in faster and more comfortable work (less time required for blood suction and dryness of the surgical field). these results coincided with previous studies (24,25). although there was another study established in 2010 by lindeboom and wijk that disagree with the results of this study, as they found that there was no significant difference in the time of surgical operation between flapless and flapped procedure. they concluded these results either real findings or due to lack of statistical power due to low number of samples used in their study(26). concerning the results and taking in consideration the limitations of this study, flapless surgical technique achieves implant stability significantly higher than traditional flapped technique with the period of three months after the surgery.also flapless surgical technique can result in predictable survival rate within three months interval if good preoperative assessment and examination was done and the time of operation that flapless implant surgery consuming is very shorter than that of traditional flapped surgical one. references 1. takie hh, carranza fa, kennedy eb,lekovic. flap technique for periodontal bone implants: papilla j bagh college dentistry vol. 28(2), june 2016 a comparative study oral and maxillofacial surgery and periodontics 97 preservation technique. j periodontol 1985; 56: 20410 2. jones aa, cochran dl. consequences of implant designs. dent clin n am 2006; 50 (3): 339-60. 3. roman gg. influence of flap design on peri implant interproximal crestal bone loss around single tooth implants. int j oral maxillofac implants 2001; 16: 61-67. 4. choi bh, jeong sm, kim j, engelke w. flapless implantology. 1st ed. germany, nuremberg: quintessence publishing co; 2010.pp. 2-81. 5. you tm, choi bh, li j, xuan f, jeong sm, jang so. morphogenesis of the periimplant mucosa: a comparison between flap and flapless procedures in the canine mandible. oral surg oral med oral pathol oral radiolendod 2009; 107(1): 66-70. 6. jeong sm, choi bh, li j, kim hs, ko cy, jung jh. flapless implant surgery: an experimental study. oral surg oral med oral pathol oral radiolendod2007; 104: 24-8. 7. kim ji, choi bh, li j, xuan f, jeong sm. blood vessels of the peri-implant mucosa: a comparasion between the flap and flapless procedures. oral surg oral med oral pathol oral radiolendod2009; 107 (4): 508-12. 8. sclar ag. guidelines for flapless surgery. j oral maxillofacsurg 2007; 65:20-32. 9. bayounis am, alzoman ha, jansen ja, babay n. healing of peri-implant tissues after flapless and flapped implant installation. j clinperiodontol. 2011; 38(8): 754-61 10. campelo ld, camara jr. flapless implant surgery: a 10-year clinical retrospective analysis. int j oral maxillofac implants 2002; 17(2): 271–6. 11. van de velde t, glor f, de bruyn h. a model study on flapless implant placement by clinicians with a different experience level in implant surgery. clin. oral impl res 2008; 19: 66–72 12. jeong sm, choi bh, kim j, lee dh, xuan f, mo du, lee dh. comparison of flap and flapless procedures for the stability of chemically modified sla titanium implants: an experimental study in a canine model. oral surg oral med oral pathol oral radiolendod 2011; 111: 170-3. 13. meredith n, alleyne d, cawley p. quantitative determination of the stability of the implant-tissue interface using resonance frequency analysis. clin oral implants res 1996; 7: 261-7. 14. zix j, hug s, kessler-liechti g, mericske-stern r. measurement of dental implant stability by resonance frequency analysis and damping capacity assessment: comparison of both techniques in a clinical trial. int j oral maxillofac implants 2008; 23: 525-30. 15. atsumi m, park sh, wang hl. methods used to assess implant stability: current status. int j oral maxillofac implants. 2007; 22 (5): 743-54. 16. vlahovic z, mihailovic b, lazic z, golubovic m. comparative radiographic and resonance frequency analyses of the peri-implant tissue after dental implants placement using flap and flapless techniques: an experimental study on domestic pigs. vojnosanit pregl 2013; 70(6): 586–94 17. kim jh, park hk, kim mk, kang sh. lifethreatening airway obstruction after flapless implant placement in the anterior mandible. j korean assoc oral maxillofacsurg 2012; 38: 310-3. 18. albrektsson t, zarb g, worthington p, eriksson ar. the long-term efficacy of currently used dental implants: a review and proposed criteria of success. int j oral maxillofac implants 1986; 1(1): 11-25. 19. zarb ga, albrektsson t. consensus report: towards optimized treatment outcomes for dental implants. j prosthet dent 1998; 80(6): 641. 20. becker w, wikesjo um, sennerby l, qahash m, hujoelp, goldstein m, turkyilmaz i. histologic evaluation of implants following flapless and flapped surgery:a study incanines. j periodontol 2006; 77 (10): 1717-22. 21. cannizzaro g, leone m, consolo u, ferri v,esposito m. immediate functional loading of implants placed with flapless surgery versus conventional implants in partially edentulous patients: a 3-year randomized controlled clinical trial. int j oral maxillofac implants. 2008; 23(5): 867-75. 22. berdougo m, fortin t, blanchet e, isidori m,bosson jl. flapless implant surgery using an image-guided system. a 1to 4-year retrospective multicenter comparative clinical study. clin implant dent relat res 2010; 12(2): 142-52. 23. glauser r, sennerby l, meredith n, re´e a, lundgren a, gottlow j,hammerle ch. resonance frequency analysis of implants subjected to immediate or early functional occlusal loading. successful vs. failing implants. clin oral implants res2004; 15(4): 428-34. 24. arisan v, karabuda cz, ozdemir t. implant surgery using boneand mucosa-supported stereolithographic guides in totally edentulous jaws: surgical and postoperative outcomes of computer-aided vs. standard techniques. clin oral implants res 2010; 21(9): 9808. 25. cannizzaro g, felice p, leone m, checchi v, esposito m. flapless versus open flap implant surgery in partially edentulous patients subjected to immediate loading: 1-year results from a split-mouth randomised controlled trial. eur j oral implantol 2011; 4 (3): 177-88. 26. lindeboom ja, van wijk aj. a comparison of two implant techniques on patientbased outcome measures: a report of flapless vs. conventional flapped implant placement. clin oral implants res 2010; 21(4): 366-70. heba f.doc j bagh college dentistry vol. 27(3), september 2015 evaluation of pedodontics, orthodontics and preventive dentistry140 evaluation of antibacterial effect of irrigant solutions (titanium tetra fluoride, green tea, sodium hypochlorite, normal saline) using real-time quantitative – polymerase chain reaction heba n. yassin, b.d.s. (1) zeyneb a. a. al-dahan, b.d.s., m.sc. (2) mohammed a. hamod, b.sc., m.sc., ph.d. (3) abstract background: removal of bacteria from the pulp system by instrumentation of an infected root canal, will be significantly reduced the number of bacteria, but it is well documented that instrumentation alone can-not clean and kill all bacteria found on the root canal walls. antibacterial irrigants are needed to kill the remaining microorganisms. the aims of this study was to assess antibacterial effect of titanium tetrafluoride (tif4) solution and brewing green tea against root canal bacteria and to compare with sodium hypochlorite and normal saline through microbiological and molecular studies. materials and methods: microbiological study was carried out to determine the concentration of titanium tetrafluoride and brewing green tea at which they exert antibacterial effect against ten swabs that had been taken from necrotic root canals that were incubated aerobically and anaerobically by paper disk diffusion test, whilemolecular study carried out among forty children in which the antibacterial effect of titanium tetrafluoride and brewing green tea compared with sodium hypochlorite and normal saline were assessed by real time polymerase chain reaction using sybr green. results: the microbiological study results showed that tif4 achieved maximum antibacterial effect at concentration 5% against aerobic and anaerobic bacteria while green tea exhibited antibacterial effect when brewed for 20 minutes at concentration 100mg/1ml against staphylococcus aureus, but not active against other microorganisms like escherichia coli and streptococcus. while results of molecular study illustrated that sodium hypochlorite remained the most effective endodontic irrigant solutions followed by titanium tetrafluoride then green tea while normal saline showed no antibacterial effect. statistically titanium tetrafluoride, green tea and sodium hypochlorite have significant differences compared to normal saline. conclusions: this study revealed that, titanium tetra fluoride and brewing green tea can be used as antibacterial irrigant solutions for root canal treatment in children. key words: antibacterial effect, titanium tetrafluoride, green tea, sodium hypochlorite, normal saline, real-time quantitative – polymerase chain reaction. (j bagh coll dentistry 2015; 27(3):140-145). introduction bacteria in a tooth's root canal both initiate and perpetuate periapical inflammatory lesions (1). thus, the aim of endodontic therapy is to remove pathogenic bacteria from the pulp system (2). this is usually accomplished by mechanical preparation along with the use of irrigant solutions. the complexity of the root canal system, presence of numerous dentinal tubules in the roots, invasion of the tubules by microorganisms, formation of smear layer during instrumentation and presence of dentin as a tissue are the major difficulties in achieving the primary objectives of complete cleaning and shaping of root canal systems (3). the purpose of endodontic irrigation is to facilitate removal of bacteria, debris and necrotic tissue (4), especially from areas of the root (1)m.sc. student. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad. (2)professor. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad. (3)lecturer. department of biotechnology, college of science, university of baghdad. canal that have been left unprepared by mechanical instruments (5). since the principal cause of treatment failure is considered to be the residual bacteria in the apical part of the root canal (6,7). endodontic irrigant that possess antibacterial properties have clearly superior effectiveness in bacterial reduction (8). titanium tetra fluoride is metal fluorides, unlike the commonly used fluorides (e.g., naf, snf2, and apf), has shown to offer greater protection against caries and tooth erosion (9). titanium itself is a nontoxic element, and no side effects have been reported with titanium tetra fluoride (10). the advantage has been credited to the titanium group present in the compound, which synergizes the effect of fluoride (11).topical application with high concentration of fluoride may be effective due to the antimicrobial effects of fluoride (12). green tea is a tea made solely from the leaves of camellia sinensis (13). green tea is unfermented, thus containing the highest concentrations of polyphenols and most likely possessing the greatest antibacterial effect (14). j bagh college dentistry vol. 27(3), september 2015 evaluation of pedodontics, orthodontics and preventive dentistry141 sodium hypochlorite had proven to be an effective solution for the chemomechanical preparation of root canal because of its antimicrobial activity and tissue dissolving ability (15). sterile normal saline is the most biocompatible irrigant solution, because it is inactive with minimum effect on the periapical tissue (16). the aims of this study to evaluate the antibacterial effect of tif4 and green tea solution when used as endodontic irrigant and to compare with the naocl and normal saline. materials and methods 1-patient selection the sample was selected from a pool of patients attending college of dentistry, university of baghdad, specialist health dental center in alma′moon and specialist dental center in alameria. the study was divided into two parts. the microbiological study included 10 patients of both sexes having necrotic pulp. in the second part, molecular study was conducted on 40 patients have necrotic pulp. in both study groups, patients were healthy and did not receive antibiotic treatment during the previous one month and age range was from 9-12 years. all selected teeth are maxillary central incisors with necrotic pulp, lack of response to pulp vitality test by using the ethyle chloride, asymptomatic, had not received previous root canal treatment and had radiographic evidence of closed apex with or without periapical lesion. 2-preparation of solution titanium tetra fluoride solution prepared by dissolving tif4 powder in deionized water with varying concentration (1%, 2%, 3%, 4%, 5 %). the green tea was brewed at 90ºc with varying concentrations of crushed dried tea leaves (40, 60, 80, 100, 140 mg/ml) and varying brewing times (10, 20, 30 min).left to cool at room temperature . green tea solution was filtered by filter paper (no.1). the resulted extract was kept in closed container in refrigerator. 3microbiological examination ten children aged (9-12) years, require root canal treatment were participated in this study. they were divided into two groups: group i (n=5) tested with varying concentration of titanium tetra fluoride solution, group ii (n=5) tested with varying concentration of green tea. after isolation of each tooth with rubber dam, the crown and the surrounding rubber dam were disinfected by 2.5% naocl for 30s. the disinfectant was air dried before access was gained to the pulp chamber and root canal (17). access opening was established without water spray, instead, as a coolant, sterile saline was dripped from a sterile disposable syringe. proper unrestricted access opening was established in the crown of the tooth by high speed hand piece with round bur no.14 to ensure complete access to the canal wall in order to acquire adequate debridement then the pulp canal was extirpated by barbed broach, swabs were taken from root canals by sterile paper points (18). paper points were immersed in the root canals of maxillary central incisors with necrotic pulps left for three minutes then immediately inserted to nutrient broth and thioglycollate broth and incubated for 72 hours at 37°c (19).the swabs streaked on macconkey agar and blood agar then incubated aerobically and anaerobically by using anaerobic jar with gas pack for 24 hours at 37°c (20). identification of microorganisms by colony morphology of bacteria, gram`s stain and biochemical testwas done (21). the antimicrobial properties of titanium fluoride and green tea were tested using paper disk diffusion test. nutrient agar plates were inoculated by spreading a lawn of the root canal culture across each plate. small paper disks were infused with the test solution by soaking in the solution for approximately 5 minutes. the disks were then placed onto the inoculated petri dishes, control disks were also preparedby soaking in the distilled water. the plates were incubated aerobically and an aerobically at 37°c for 48 hours. after incubation the zones of inhibition were measured using a ruler (22). 4-endodontic sample collection in the clinical trial, forty teeth were prepared in the same procedure of swabbing in microbiological study for root canals sample collection for molecular study in which paper point was immerse in the canal and left for 3 minutes then immediately insert to an eppendorf tube containing 200 µl of tris-edta buffer (10 mmol/l tris-hcl, 1 mmol/l edta, and ph 8). the canals in each group were irrigated with 5ml of specific irrigation solution (10 canals with 5% tif4, 10 canals with 10% green tea,10 canals with 5% naocl and 10 canals with 0.9% normal saline) with disposable syringe (23-gauge needle). each canal was immerse with irrigant solution for three minutes then another sterile paper point was insert inside the canal of tooth for three minutes then immediately insert to an eppendorf j bagh college dentistry vol. 27(3), september 2015 evaluation of pedodontics, orthodontics and preventive dentistry142 tube containing 200 µl of tris-edta buffer and vortexed for 60s .the eppendorf tubes were transferred on dry ice and stored at (-20ºc) immediately. collection lasted almost 3 months and the time from the sampling procedure until the processing of the dna ranged between three and three and half months. 5-real-time quantitative-polymerase chain reaction extraction of genomic dna from gram negative and positive bacteria by using exiprep™ bacteria genomic dna kit (bioneer).the deep frozen preand post-preparation sample were thawed on ice and dispersed by vortexing for 1 minute.dna was extracted and purified with exiprep™ 16 plus dx automated nucleic acid extraction system (according to the manufacturer's instructions). by using this extraction method, dna from both gram-positive and gram-negative bacteria was retrieved with no apparent discrimination against either bacterial group .the extracted dna was quantified in a spectrophotometer at 260 nm and stored at –20°c until required. a real-time pcr procedure was used for relative quantification of root canal bacteria (gram positive and negative). quantification was performed using sybr green method and one universal 16s rdna primer. primers were designed from highly conserved regions of the 16sdna gene sequence of salmonella enterica (genbank accession no. u90316) (23): forward primer euf:5′ctgtcgtcagctcgtgttgt– 3′,reverseprimereur:5′cgtaagggccatgat gactt –3′, amplifying 157 bp (according to salmonella enterica position). amplification and detection of dna by rtqpcr was performed with the aid of the sequence detection system (exicycler™ 96, bioneerkorea) using optical grade 96-well plates. in each run, four negative controls nuclease free water as template were used. all samples were analysed using accupower® greenstar qpcr premix (bioneer). samples were run in duplicate in a total volume of 20µl. final reactions contained (10 pmol l)1 µl of each primer, 5 µl of templatedna and depcdistal water adjust to 20 µl .thetemperature profiles were as follows: sybr green: denaturation 94 °cfor 5 min; 40 cycles: 94 °cfor20 sec, stringent annealing at 64 °cfor20 sec, and elongation at 72 °cfor 20 sec. melting curve analysis was performed to assess reaction specificity. after reaction is completed, data analysis performed. dna was calculated by determining the threshold cycle (ct), the number of pcr cycles required for the fluorescence to exceed a threshold value significantly higher than the background fluorescence. results the results of the microbiological study, indicated that the titanium tetra fluoride at concentration 5% produced same zone of inhibition against both aerobic and anaerobic bacteria with mean zones of inhibition 17.2 mm higher than other concentration (1%, 2%, 3%and 4%).this is shown in figure (1). while green tea showed that the most effective concentration was 100 mg/ml with an average zone of inhibition of 20.4mm and also most effective brewing time was 20 minutes. however, for the 30 minutes, the concentration 140 mg/ml was effective with an average zone of inhibition of 13mm. it was also found that at brewing time 10 minutes, green tea proved ineffective in preventing the growth of bacteria, with all five concentrations exhibiting no zones of inhibition (figure 2). green tea at concentration of 100 mg / ml that brewed for twenty minutes affects only on one type of bacteria isolated from infected root canal that is staph. aureus with mean zone of inhibition 20.4mm while other types of bacteria isolated from the same root canals such as e. coli and streptococcus unaffected versa show growth rather than inhibition. according to anova test the results show high significant difference in sensitivity of staph. arueus to green tea compared to the streptococcus and e. coli (p value =0.001) (table1). table (2) represent the result of real time pcr include mean of ct value (threshold cycle) for different irrigant solutions before and after treatment. the result show that the mean value of ct after treatment increased for groups treated with titanium tetra fluoride, green tea and sodium hypochlorite indicate succeeded in significantly reducing the number of bacterial taxa, only group treated with normal saline show decrease in mean ct value that indicate increase significantly in number of bacteria. the result of anova test demonstrated significant difference between group irrigated with normal saline and other three groups (tif4, green tea and naocl).no significant differences were found between group irrigated with 5% tif4, group irrigated with 100mg/ml green tea and group irrigated with 5% sodium hypochlorite. j bagh college dentistry vol. 27(3), september 2015 evaluation of pedodontics, orthodontics and preventive dentistry143 table 1: comparison of the antibacterial effect of green tea among different bacteria of root canals bacterial isolated zone of inhibition (mean) p value staphylococcus aureus 20.4 0.001 (hs) streptococcus 0 e. coli 0 table 2: multiple comparisons of antibacterial effects of different irrigation solutions before and after treatment groups mean ± s.e. p-value pre-treatment post-treatment tif4 22.46 ± 0.27a 25.34 ± 0.47a 0.01 green tea 22.94 ± 0.23a 25.16 ± 0.77a 0.01 naocl 23.16 ± 0.28a 26.06 ± 0.75a 0.01 normal saline 23.07 ± 0.44a 21.51 ± 0.88b 0.05 different letters: significant difference (p ≤ 0.05) between means of columns discussion the results of the study indicated that tif4 showed antimicrobial effect when used as root canal irrigant at different concentration, but the best antibacterial effect was noticed at concentration of 5% due to the fact that tif4 contain fluoride in their structures and used higher concentration of tif4 mean higher concentration of fluoride and fluoride at high concentration have antibacterial effect (13). fluorine ions released from fluoride can affect bacterial metabolism as an enzyme inhibitor. at the lower external ph provided by low ph of tif4 solution, fluoride diffuses into bacteria in the form of hf (a weak acid), because of a higher internal ph of cells than external more hf diffuses inside the bacterial cell and hf dissociates into h + and f – .this continued diffusion and dissociation leads to the accumulation of fluoride in the cell and the acidification (accumulation of h+) of the cytoplasm. the result is a reduction in both the proton gradient and the enzyme activity that induced effective inhibitors of bacteria (24). the results demonstrate that the green tea brewed for 10 minutes was ineffective in killing the bacteria. the tea brewed for 30 minutes was effective in killing the bacterial cultures, but was not as efficient as the tea brewed for 20 minutes. the longer the green tea leaves were infused in the hot water, the greater the breakdown of the antibacterial polyphenolic compounds, rendering the tea less effective. in this study green tea at concentration 100mg/ml and brewing time 20 minutes inhibited the growth of staphylococcus aureus isolated from swabs of infected root canals and ineffective against other bacteria isolated from same root canals like e. coli and streptococcus. green tea’s effectiveness as an antimicrobial agent can in part be attributed to its low degree of fermentation. during the fermentation process, catechins such as epigallocatechin gallate (egcg) are destroyed, reducing the tea’s antimicrobial properties. the antibacterial activity also is due to inhibition of bacterial enzyme gyrase by binding to atp b sub unit (25). real time pcr was used to compare antibacterial activity of 5%tif4 and 10% green tea with that of 5% sodium hypochlorite and0.9% normal saline. table (2) show that group irrigated with tif4 produced increased in ct value compared to ct value before irrigation indicate successful in reducing the bacteria count because reactions with lower ct values contain more of the gene of interest since they took less time to amplify. in figure 2: zones of inhibition for different green tea concentration and brewing time's figure 1: zones of inhibition for different titanium tetra fluoride concentration j bagh college dentistry vol. 27(3), september 2015 evaluation of pedodontics, orthodontics and preventive dentistry144 the same way, samples with a higher ct contain less of the gene of interest (26). there are two possible explanations for antibacterial mechanism of the titanium tetra fluoride. on one hand, the action of the fluorine ions could be responsible for this mechanism; on the other hand, the action of the metal-fluoride complexes are also responsible for fluoride inhibition of proton-translocating f-atpases and are thought to act by simulating phosphate to form complexes with adp at the reaction centers of the enzymes (13,27). herbal products such as green tea have been used in dental practice and have become more popular today due to their high antimicrobial activity, biocompatibility, antiinflammatory and anti oxidant properties (28). the results show that group irrigated with green tea produced increased in ct value in comparison to ct value before irrigation which indicates successful reduction in the bacterial number (table 2). antibacterial properties of green tea have been associated with the polyphenol catechin fractions which constitute up to 30% of solid green tea leave (29,30). egcg is the most abundant of these catechins, comprising about 50% of the catechin pool. it had been shown that catechin components of green tea and particularly (egcg), epigallocatechin and epicatechin-3-gallate, which are all catechin derivatives having a galloyl moiety linked by an ester linkage, constitute the most important antibacterial agents in green tea (31). the group irrigated with sodium hypochlorite produced increased in ct value compared to ct value before irrigation indicates successful in reduction the number of bacteria, naocl still the most frequently used root canal irrigant, the antibacterial effect of 5% sodium hypochlorite could be attributed to the irreversible inactivation of the bacterial essential enzymatic site through the action of hydroxyl ions and the chloramination process. sodium hypochlorite when come in contact with organic tissue releases chlorine that could combine with protein amino group to form chloramine which exerts its antimicrobial action through interfering with cellular metabolism, thus naocl has powerful germicidal properties (32). the result of this study showed that normal saline had no antibacterial effect against root canal bacteria. it produced decrease in ct value (table 2), this indicate increased in bacterial count .this increase in bacteria can be explained by washing action of saline may cause extrusion of bacteria from periapical lesion to root canal system. under the conditions of this study tif4 solution can be used as an endodontic irrigant since it possess an excellent antibacterial action similar to sodium hypochlorite. also green tea can be used as an endodontic irrigant because it show an acceptable antibacterial effect and nontoxic because it is natural agent. references 1. horz hp, vianna me, gomes b, conrads g. evaluation of universal probes and primer sets for assessing total bacterial load in clinical samples: general implications and practical use in endodontic antimicrobial therapy. j clin microbiol 2005; 43(10): 5332–7. 2. saleh im, rytler le, haapasalo d. survival of enterococcus feacalis in infected dentinal tubules after root canal filling with different root canal sealers: in vitro study. j endod 2004; 37: 193-8. 3. torabinejad m, handysides r, khademi a, bakland lk. clinical implications of the smear layer in endodontics: a review. oral surg oral med oral pathol oral radiol endod 2002; 94: 658-66. 4. lee sj, wu mk and wesselink pr. the effectiveness of syringe irrigation and ultrasonics to remove debris from simulated irregularities within prepared root canal walls. intern endod j 2004; 37(10): 672–8. 5. gulabivala k, patel b, evans g, ng yl. effects of mechanical and chemical procedures on root canal surfaces. endodontic topics 2005; 10: 103–22. 6. nair, pn, sjogren u, krey g, kahnberg k, sundqvist g. intraradicular bacteria and fungi in root-filled, asymptomatic human teeth with therapy-resistant periapical lesions: a long-term light and electron microscopic follow-up study. j endod 1990; 16: 5808. 7. sjogren u, hagglund b, sundqvist g, wing k. factors affecting the long-term results of endodontic treatment. j endod 1990; 16: 498-504. 8. siqueira jf, jmachado ag, silveira rm, lopes hp and de uzeda m. evaluation of the effectiveness of sodium hypochlorite used with three irrigation methods in the elimination of enterococcus faecalis from the root canal, in vitro. int endod j 1997; 30 (4): 279-82. 9. buyukyilmaz t, sen bh, qgaard b. long term retention of titanium tetrafluoride used as fissure sealent on deciduous molars. acta odontol scand 1997; 55(2):73-8 10. shresta bm. effect of systemic titanium tetra fluoride on fluoride uptake by developing rat enamel (short communication). caries res 1983; 17: 264-6 . 11. tezel h, ergucu z, onal b. effects of topical fluoride agents on artificial enamel lesion formation in vitro. quintessence int 2002; 33: 347-52. 12. marquis re. antimicrobial actions of fluoride for oral bacteria. can j microbiol 1995; 41: 955-64. 13. tyler v, brady l, robbers j. pharmacology. 9th ed. philadelphia: jb lippincott; 1988. p. 247-8. 14. sinija vr, mishra hn. green tea: health benefits, j nutritional and environmental medicine 2008; 17(4): 232-42. j bagh college dentistry vol. 27(3), september 2015 evaluation of pedodontics, orthodontics and preventive dentistry145 15. emboava jc, luiz e, dementino t, fernando l. solvent action of sodium hypochlorite on bovine pulp and physiochemical properties of resulting liquid. braz dent j 2001; 1: 154–7. 16. griffiths bm, stock cr. the efficiency of irrigants in the removing root canal debris when used with an ultrasonic preparation technique. int endod 1986; 19: 277. 17. ng yl, spratt d, sriskantharajah s. evaluation of protocols for field decontamination before bacterial sampling of root canals for contemporary microbiology techniques. j endod 2003; 29: 317 -20. 18. zavistosky j, dzink a, bartlett j. quantitative bacteriology of endodontic infections. oral surg 1980; 49:171-4. 19. sutter in, litiond m, eldeistein m. a. wads worth anaerobic bacteriology manual. 4th ed. california: stur pubi co.; 1986. p.130-45. 20. musa mj. isolation and identification of microfloral associated filling anterior teeth. a master thesis, college of dentistry, baghdad university, 1994. 21. ryan kj, ray cg. sherris medical microbiology. 4th ed. mcgraw hill: 2004 22. sassone lm, fidel ra, murad cf, fidel sr. sodium hypochlorite and chlorhexidine by two different tests. aust endod j 2008; 34:19-24. 23. arvidsson s, kwasniewski m, rianopachon d, mucller-roeber b. quantprim-a flexible tool for reliable high-throughput primer design for quantitative pcr. bmc bioinformatics 2008; 9: 465-80. 24. hamilton ir. biochemical effects of fluoride on oral bacteria. j dent res1990; 660(7): 682-3. 25. gradisar h, pristovsek p, plaper a. green tea catechins inhibit bacterial dna gyrase by interaction with its atp binding site. j med chem 2007; 50(2): 264-71. 26. claire reardon. guidelines for designing real time pcr experiments, reviewers: christian daly; 2004. p. 5. 27. forss h, jokinen j, spets-happonen s, seppa l , luoma h. fluoride and mutans streptococci in plaque grown on glass ionomer and composite. caries res 1991; 25(6): 454-8. 28. pujar m, makandar s. herbal usage in endodontics a review. int j contemporary dentistry 2011; 2(1): 34-7. 29. chacko sm, thambi pt , kuttan r. beneficial effects of green tea: a literature review.chin med 2010; 5: 1– 13. 30. abdolmehdi a, jamshid k, mohammad m. inhibitory activity of green tea (camellia sinensis) extract on some clinically isolated cariogenic and periodontopathic bacteria. med princ pract 2013; 22(4): 368–372. 31. sakanaka s., okada y.inhibitory effects of green tea polyphenols on the production of virulence factor of the periodontal-disease causing anaerobic bacterium porphyromonas gingivalis. j agric food chem 2004; 52: 1688– 92. 32. estrala c, estrala cra, barbin el, spano jc, marchesan ma, percora d. mechanism of action of sodium hypochlorite. braz dent j 2002; 13(2):113-7. الخالصھ ، ولكن ان إزالة البكتیریا المرضیھ بصوره میكانیكیھ في عالج قنوات الجذور المصابھ بااللتھابات قد یسبب انخفاض في عدد كبیر من البكتیریا :المقدمھ لحاجھ إلى الطریقھ المیكانیكیھ لوحدھا ال تعمل على تنظیف قناة الجذر المصابھ و قتل جمیع البكتیریا الموجوده على جدران القناة لذلك تستدعي ااستعمال تقییم تأثیر محلول التیتانیوم رباعي الفلوراید ومغلي ھذه الدراسھھوان الھدف من .مضاده للبكتریا لقتل الكائنات الحیھ الدقیقھ المتبقیھ محالیل اروائیھاستعمال المغذي من خالل الشاي األخضر كمضاد للبكتریا عند استعمالھ كمحالیل اروائیھ لقنوات جذور االسنان وذلك بمقارنتھا مع ھایبوكلوریت الصودیوم والمحلول .دراسة االحیاء المجھریھ و الجزیئیھ ضد التي یكون لھا تاثیر مضاده للبكتریالتحدید تركیز التیتانیوم رباعي الفلورید ومغلي الشاي األخضر االحیاء المجھریھالدراسة اجریت:المواد وطرائق العمل اجریت اما الدراسة الجزیئیة . طریقة ورقة قرص اختبار االنتشار باستخدامعشرة مسحات مأخوذة من قنوات جذور االسنان المصابھ حضنت ھوائیا و الھوائیا تأثیر المحالیل االروائیھ على البكتریا باستعمال محلول التیتانیوم رباعي الفلوراید ومغلي الشاي األخضر مقارنة مع ھایبوكلوریت حیث تم تقییم على اربعین طفل .الخضراء sybrالصودیوم والمحلول المغذي بواسطھ الوقت الحقیقي الكمي لسلسلھ تفاعاللبلمرھباستخدام ٪ یحقق تاثیر مضاد للبكتیریا الھوائیة والالھوائیة بینما الشاي األخضر 5أظھرت نتائج دراسة االحیاء المجھریھ بأن التیتانیوم رباعي الفلوراید بتركیز :جالنتائ على الكائنات الحیة الدقیقة لھ مللترولكن لیست فعا\ملغم100دقیقة و بتركیز 20عندما اغلي لمدة staphylococcus aureusأظھر تأثیرا مضاد لبكتریا ان محلول ھایبوكلوریت الصودیوم ھو األكثر فعالیھ یلیھ , أظھرت نتائج الدراسھ الجزیئیھ. escherichia coli and streptococcusاألخرى مثل كما بینت الدراسھ اإلحصائیة ان . تأثیر مضاد للبكتریا التیتانیوم رباعي الفلوراید ثم الشاي األخضر في حین أظھرت الدراسھ ان المحلول المغذي لیس لھ أي .الشاي األخضر و ھاببوكلوریت الصودیوم مع المحلول المغذي, ھناك فرق معنوي عند مقارنة التیتانیوم رباعي الفلوراید األخضر یمكن استخدامھ كمحلول اروائي في مجال عالج قنوات اعتمادا على نتائج ھذه الدراسھ فقد تبین ان التیتانیوم رباعي الفلوراید ومغلي الشاي : االستنتاج .الجذور لألطفال سلسلھ –الوقت الحقیقي الكمي , تأثیر مضاد للبكتریا، التیتانیوم رباعي الفلوراید، الشاي األخضر، ھایبوكلوریت الصودیوم، المحلول المّغذي: الكلمات الرئیسیة .تفاعل البلمره 10. intsar f.doc j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 62 an evaluation of some mechanical properties of autopolymerizing acrylic resin with the modified one after changing the curing environment: (in vitro study) intisar j. ismail, b.d.s., m.sc., ph.d. (1) abstract background: studying and investigating the transverse strength(ts), impact strength(is), hardness (hr) and surface roughness(ra) of conventional and modified autopolymerizing acrylic resin with different weight percentages of biopolymer kraftlignin, after curing in different water temperatures; 40°c and 80°c. material and methods: standard acrylic specimens were fabricated according to ada specification no.12 for transverse strength, iso 179 was used for impact testing, shore d for hardness and profilometerfor surface roughness. the material lignin first dispersed in the monomer, then the powder pmma is immediately added. lignin added in different weight percentages. then cured using pressure pot (ivomet) in two temperatures;40°c and 80°c under 2 bar pressure, for 30 minutes.atotal of 144samples were prepared for this study. ts, is, ra, and hr were tested, by using instron universal testing machine, charpy impact tester, shore d tester, and profilometer respectively. results: the transverse strength increased in both the conventional and modified onewhen compared with that cured in air. the addition of 0.5wt% lignin gave the higher effect (78.0017mpa) with highly significant difference found between groups at 40°c polymerizing temperature. while the impact strength in both temperatures in the modified resin revealed increased results than conventional one, 1.25wt% of kraft lignin gave the highest value (12.7355kj/m2) with highly significant differences found between groups at 80°c polymerizing temperature. hardness and surface roughness showed also highly significant differences found between groups at 40°c polymerizing temperature, all the groups had increased hr. than the control one (78.95), while the ra. decreased for 1.0% ,1.25,1.50 and 1.75 wt% lignin content to (0.26,0.10,0.063, 0.12µm) respectively in 40°c polymerizing temperature, the lowest value present in 1.75 wt% lignin (0.05 µm) at 80°cpolymerizing temperature. conclusions: it seems that increasing the polymerizing temperature to 40°c had a positive effect on the mechanical properties of autopolymerizing acrylic resin and the one enforced by kraft lignin biopolymer in low percentages. increasing the polymerizing temperature to 80°c will doesn’t have much positive effect but it doesn’t deteriorate the mechanical properties. however, when submitted to increasing the temperature to 80°c, specimens showed a significantincrease in impact strength. key words: autopolymerizing acrylic, kraft lignin, curing temperature. (j bagh coll dentistry 2015; 27(4):62-71). introduction denture fracture is a common problem in prosthodontics (1). autopolymerized (2), heat polymerized (3), visible light polymerized (2,3), and microwave polymerized acrylic resins (3) have been used to repair fractured dentures. although various materials have been proposed for repairing fractured denture bases, autopolymerizing acrylic repair resin is still usedfor denture repair materials in daily practice, so that the repairs can be easily employed at room temperature in a short time (4,5). nowadays, studies were developed on potential of natural fibers as reinforcement in thermoplastics.there are many fibers that have been explored as reinforcement for polymer matrix(6). lignin in plants is the most abundant organic polymer after cellulose, lignin is nontoxic source and rich in renewable resources, so it is widely used in industry. it is mainly used as raw materials and additives such as adhesives, dispersant, chelating agent and emulsifier (7). (1)assistant professor. department of prosthodontics, college of dentistry, university of baghdad. previous quantitative research done by ismail(8) showed that addition of copolymer produced from lignin-graft-pmma, in concentration of 3.0wt% and less, produced favourable mechanical properties for the denture base acrylic resin. further study done by ismail et,al.,(9) evaluated the transverse strength and impact strength of autopolymerizing acrylic resin polymerized in air, after modified with kraft lignin from 0.25wt% to 1.5wt%. the results revealed that modified autopolymerizing resin exhibited significantly higher impact strength, the transverse strength of the modified specimenswas increased only on o.25wt% addition of lignin. these positive findings made the new modified denture resins attractive for future dental applications. it should be mentioned that repairing with autopolymerized resin is much weaker than the originally used heat polymerized denture resin (5). attempts have been made to improve the mechanical properties of the repaired sites by changing either the joint surface contours (10), the processing methods (10,11), optimizing the distance between repaired sites (12-14). one of the problems withdenture repair, however, is that it is weaker than the original prosthesis and may re-fracture j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 63 within ashort period of time. often it occurs at the interface junction of the original base and repair materials(15). ogawa et,al.,(16) reported that changing of polymerization temperature had a significant effect on both the transverse strength and modulus of the resin, both increased with an increase in water temperature. they concluded that polymerization of the resin in hot water greatly increased its mechanical properties. machado et, al.,(17) reported better results may be expected when autopolymerizing acrylics are cured under controlled heat and pressure state. different polymerization techniques have been used to increase the degree of conversion of autopolymerize orthodonting acrylic and enhance their properties.” donovan et, al., (18) reported that an acrylic cured under 20 psi pressure presented increase transversal strength and lesser porosity. the results of another study showed a decrease in the residual monomer and an increase of resin strength when the water temperature was raised from 20°c to 30°c. (19) likewise, a lower amount of residual monomer has been observed in resins polymerized at 60°c (20). the temperature elevation with pressure has been shown to increase the microhardness (21) and flexural strength (11) of acrylic resins. surface hardness could be related to degradation of the restoration, since this property is directly related to the quality of polymerization and cross-link density of thematerial, and specifically for resin composites, to its filler content(22). the presence of a rough surface on the restoration favours bacterial adhesion and dental biofilm formation, resulting in gingival inflammation and periodontal bone resorption (23). furthermore, a rougher surface affects light reflection and brightness of the restorative material, as well as favoursdiscoloration and staining. clinical success and longevity of complete dentures depend on physical and mechanical properties of polymers. one of the most important properties of a denture base is strength, the denture base must be able to withstand high impact forces and normal masticatory forces (24,25) conducted a study to determine how the polymerization at different temperatures and for the various length of time affects the transverse strength of autopolymerizing pmma and glassfiber composite, for this purpose they were cured for various length of time at different temperatures, the results revealed that the highest transverse strength for the pmma-glass fiber composite was obtained by curing for 120 min at 100°c and lowest strength was obtained by polymerizing at 150°c. kuharand and funduk (26) observed that surface roughness of acrylic denture base resins depends on the polishing technique utilized.alves et al(27)conducted a laboratory evaluation of the surface roughness of acrylic resins after different curing and polishing techniques. the present study aims at: 1. to evaluate the effectiveness of changing polymerizing temperature in water and adding pressure on the autopolymerizing acrylic resin and modified pmma auto resin with lignin, and then compare the transverse strength and impact strength of autopolymerizing acrylic specimens with one reinforced with lignin in different percentages (0.5, 1.0, 1.25, 1.5, 1.75 wt%). 2. surface roughness and hardness are important factors in determining the serviceability of provisional restorations, so we evaluate these properties in those conditions, for its application as denture base repair resin in the same percentages. materials and methods the present study conducted in the department of prosthodontics, the materials used in current study include: self-cured polymethyl methacrylate (powder and liquid), kraft lignin alkali (powder, aldrich company). the following equipment were used in the current study: 1. stainless steel specimens for mould preparation. 2. modeling wax 3. dental stone 4. aprobesonicated apparatus.(fig1.a) 5. pressure pot (ivomet) (fig 1.c) 6. dental flask and clamp (fig 1.d) 7. cold mould seal 8. vernier callipers 9. sand paper, diamond disc , stone burs and rag wheel 10. bench press (germany). j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 64 figure (1): the instruments used in the experimental study. combinations of the three curing factors of temperature, pressure, curing environment (water) were adjusted during the fabrication of autopolymerized specimens. synthesis of modified pmma polymers: modified pmma polymers were made by polymerization of mixtures of varying proportions of methyl methacrylate (mma) and kraft lignin, they included from 0.5,1.0,1.25,1.5 and 1.75wt% of lignin,to optimize resin material and assure adequate impregnation of lignin within the monomer, lignin was mixed for three minutes bya probe sonication apparatus figure (1-a, 1-b) which gives ultrasound waves leading to more dispersion of lignin in the monomer, then the powder was mixed 12gm/6ml wt/v according to manufacturer instructions until reaching the dough stage, then packed directly in the flask within a previously prepared moulds from stainless steel specimens, the two halves of the flask closed within ten seconds and placed under press (hydrolic press germany) with application of pressure until all the access go out the flask. after releasing immediately, put it in (ivomet) pressure potfigure (1-c) in 40°c and 2bar for 30minutes, all the specimens cured in this manner, then the other groups cured to 80°c,2bar for 30minuts. a total of 144 specimens were fabricated for this study, six specimens for each test to all percentages. all the specimens were finished using the usual way of finishing dentures, polishing done using rag wheel with pumice, each sample was marked by its material group (from af)and sample number. each plate group strips were finished to the calibrated dimensions [65 mm (l) x 10 mm (w) × 2.5 mm (d)] for ts, hr,ra, and 55mm long, 10.0 ± 0.03 mm broad and 10.0 ±0.03mm thick for is were used. the samples were simply polished to minimize surface roughness. the samples were washed with distilled water to remove any residual monomer and then stored in distilled water at 37°c for 48 ± 2 hours before testing. transverse strength test was done by instron universal testing machine and impact resistance test was done by charpy-type machine, hardness tested by shore-d device, and surface roughness by prolifelometer. evaluation of transverse strength: utilizing a 3-point flexural test, using instron universal testing machine. the specimens were tested for transverse strength at a uniform cross head speed of 2mm / min and span length of 50mm with maximum load of 50kg.the load was applied to the centre of specimen until fracture occurred. the amount of deflection and the load at fracture were noted. the transverse strength was calculated using the following formula. transverse strength (s) = 3 pl (2bd2)-1= mpa p = fracture load (n) l = span length (mm) b = sample width (mm) d = sample thickness(mm) evaluation of impact strength: impact strength test: charpy impact strength of unnotched specimens was adopted, the impact energy absorbed in breaking an unnotched specimen, according to iso 1791982.the specimens were supported horizontally at two ends and a swinging pendulum had struck in its middle by a 2 joules, free swinging, pendulum which is released from a fixed height. and digital display to show the impact energy. a pendulum of testing capacity was used. some samples offered resistance to the shock, without fracture therefore; five joules pendulum was used. impact strength = e(b x d) -1x 103=kj m-2 e = is the impact energy in joules. b= is the width dimension, in millimeters, of the test specimen. d = is the height dimension, in millimeters, of the test specimen. a. apparatus b. monemer inside a c. ivomet d. samples in flask j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 65 measuring surface roughness (ra): surface roughness of the acrylic resin specimens after simple finishing by sand paper was measured using a contact profilometer (taylor hobson form talysurfpgi-840, usa). surface roughness (ra), measured in μm, was determined by the instrument’s diamond stylus as it moved across the specimen surface. the path of the diamond stylus was perpendicular to the direction of finishing. the cut off length of each tracing was 2 mm. three measurements of surface roughness were performed for specimen, and mean average ra values were used for the statistical analysis. indentation hardness test: the plates of the test were prepared as in transverse strength specimens, thickness of 2.5mm±0.03. each plate was measuring 65mm x10mm x 2.5mm±0.03mm, length, width and depth respectively. “an instrument called shore "d" durometer, which is suitable for acrylic resin material is used. the instrument consists of blunt-pointed indenter 0.8mm in diameter that tapers to a cylinder 1.6mm. the indenter is attached to a digital scale that is graduated from 0 to 100 units.”(8).the usual method is to press down firmly and quickly on the indenter and record the maximum reading as the shore "d" hardness. after that the measurements were taken directly from the scale reading. five measurements were done on different areas of each specimen and an average of five readings was calculated statistical analysis: statistical analyses were done by using spss version 16 (statistical package for social science). results the present in-vitro study was conducted to evaluate and compare the transverse and impact strength, surface roughness and hardness of conventional and modified autopolymerizing cure resin test specimens. evaluation of transverse strength: table 1 showed mean and standard deviation for transverse strength (mpa) of control group and all other groups. addition of lignin in 0.5wt%, give the higher effect (78.0017mpa). the results then showed decreasing in the range but it still higher than in air polymerization (56.1475 mpa)from previous study (9) also (28). so increasing the polymerizing temperature to 40°c with pressure 2 bar in ivomet curing unit, lead to increase in the transverse strength in all groups than the curing in air. using anova test revealed highly significant differences between the tested groups, while increasing the curing temperature to 80°c with 2bar pressure led to increase the transverse strength of all groups in comparison with air polymerization but it’s somewhat deceased at80°c than 40°c polymerizing temperature, in the control (64.9582mpa), 0.5(63.6421mpa) and 1.0 wt% and increased in 1.5(67.7557 mpa) as shown in. using anova test revealed no significant differences between the tested groups , when using donett-t test for more comparison between each tested group and the control, showed highly significance differences in all of 40°c groups accept of 1.0% as shown in table 2. table 2 showed statistical comparison (donnet t-test) of the mean transverse strength (mpa) of samples of control group, with the samples of different concentration of kraft lignin in 40°c. impact strength test results: the alteration of polymerizing conditions revealed that the impact strength in the control group less than in the air polymerizing from the previous study, which are (9.2525 kj/m2) and (15.2100 kj/m2) for the 0.75 wt% lignin addition, which is the highest level, while in this study the results revealed (7.2166kj/m2)for the control group ,and (8.5957kj/m2)at 1.0wt% group, then the results tend to decrease to (6.9082kj/m2)at 1.75wt% of lignin when using 40°c water temperature at 2bar pressure for 30minutes as shown in table(3).applying anova test between groups produced a highly significant differences. resin polymerized in 80°c water demonstrated higher impact strength at 0.5,1.0,1.25,1.5wt% than that cured in 40°c water temperature, highly sig. differences were found between groups (p<0.05) when applying anova test ,as appeared in table (3). the highest level of impact strength was (12.7354kj/m2) at 1.25 wt% of lignin addition. applying multiple comparisons post hoc test using donnett t test between each group and the control one revealed that there is no sig. difference in all groups accept 1.0 wt% (sig.0.009) in 40°c curing, but highly sig. differences in 1.0 wt and 1.25 wt% groups in curing temperature 80°c.as shown in table 4. indentation hardness test: measurement of the hardness initially gave some indication of the wear resistance. the shore "d" hardness number is directly related to the indentation hardness of the tested material. six specimens from each mixtures of both autopolymerizing resin and the one modified by j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 66 kl with acrylic resin material were tested to determine their hardness number. the results of test, which are shown in table 7, indicated that indentation resistance increases with the concentration of kl0.5% which had the highest mean value (85.125) while for the lowest kl modified pmma1.50wt% value (82.625) followed by 1.25wt% which had (83.100) indentation hardness number . anova test in table 7 reveals that there is highly significant difference in mean hardness between groups in the modified polymer with kl content cured in 40°c water temperature, while the 80°c groups had no significant differences between the groups. applying multiple comparisons post hoc test using dunnett t test between each group and the control one revealed that there is highly significant difference in all groups accept 1.5 wt% (sig.0.022) in 40°c curing, as shown in table 6). surface roughness: the surface roughness was influenced greatly by the addition procedure. in general, autopolymerizing resin specimens exhibited significantly (p < 0.01) higher surface roughness (ra = 0.27 µm) compared to modified acrylic resin (ra = 0.12 µm) in 1.75 wt% specimens. in autopolymerizing resin specimens, surface roughness reduced significantly (p < 0.01) after polymerizing in 40°c and 2bar pressure. among the different groups, specimens with1.50 wt% kl exhibited significantly (p < 0.01) lower roughness (ra = 0.06 µm) followed by 1.25% (ra = 0.10 µm) and 1.75 wt% kl smoothest (ra = 0.12 µm) surfaces. however, in curing temperature 80°c, no significant difference found between groups. the least surface roughness found in 1.75 wt% group (0.05µm) followed by 1.5 wt% (0.09 µm) as shown in table 7. applying multiple comparisons post hoc test using dunnett t test between each group and the control one revealed that there is highly significant difference in groups 1.25,1.5 and 1.75wt% in 40°c curing, as shown in table 8. table (1): mean, standard deviation and anova test results of transverse strength related to kraft lignin wt % at different cured temperatures. table (2): multiple comparison of transverse strength (mpa) test result dunnett t (2sided) dependent variable (i) kraft lignin (wt%) (j)control mean difference (i-j) std. error sig. tr.st.at cur. temp(40°c) 0.5 control 6.65973* 1.27365 .000 1 control -2.69074 1.27365 .171 1.25 control -11.99722* 1.27365 .000 1.5 control -5.49837* 1.27365 .002 1.75 control -10.11447* 1.27365 .000 *. the mean difference is significant at the 0.05 level. tested groups mean std. deviation minimum maximum tr.st.at cur. temp(40°c) control 71.3420 .75228 70.61 72.00 0.5 78.0017 2.15873 75.67 80.53 1 68.6512 .71231 67.89 69.57 1.25 59.3448 .82814 58.76 60.54 1.5 65.8436 3.32925 62.36 69.40 1.75 61.2275 1.40108 59.49 62.78 tr.st.at cur. temp(80°c) control 64.9582 2.80920 61.17 67.41 0.5 63.6421 2.47269 60.10 65.72 1 64.2732 6.71705 56.30 69.98 1.25 62.3860 3.50122 58.65 67.03 1.5 67.7557 1.43254 66.05 69.55 1.75 61.9765 2.34123 59.87 65.29 anova sum of square df mean square f sig. tr.st.at cur.temp(40°c) bet. groups 939.640 5 187.928 57.925 hs tr.st.at cur.temp(80°c) bet. groups 87.049 5 17.410 1.324 ns j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 67 table (3): descriptive data and anova result of impact strength related to different curing temperatures. mean std. deviation minimum maximum impact (kj/m2) cur.temp(40°c) control 7.216620 .2943576 6.8420 7.4831 0.5 7.017650 .1194793 6.8711 7.1390 1 8.595648 .5276480 7.9650 9.2507 1.25 7.831500 .6986683 7.3476 8.8650 1.5 7.466675 .5117103 6.8602 7.9621 1.75 6.908218 .7969522 5.9472 7.8923 impact (kj/m2) cur.temp(80°c) control 6.682400 .2576400 6.3458 6.9591 0.5 7.813900 .7265660 6.8773 8.6441 1 9.541425 .4041328 8.9421 9.8197 1.25 12.735425 .8844335 11.7378 13.4848 1.5 7.829800 .5509666 7.1349 8.4832 1.75 6.653600 .5426205 6.1995 7.3394 anova impact strength (kj/m2) sum of squ. df mean sq. f sig. cur.temp(40°c) betweengroups 7.898 5 1.580 5.371 .003 cur.temp(80°c) between groups 106.581 5 21.316 59.826 .000 table (4): multiple comparisons of impact strength test at different curing temperatures. dunnett t (2sided) dependent variable (i) kl(wt%) (j)control mean difference (i-j) std. error sig. impact (kj/m2) at cur.temp(40°c) 0.5 control -.1989700 .3834549 .978 1 control 1.3790275* .3834549 .009 1.25 control .6148800 .3834549 .387 1.5 control .2500550 .3834549 .945 1.75 control -.3084025 .3834549 .884 impact(kj/m2)at cur.temp(80°c) 0.5 control 1.1315000 .4220805 .059 1 control 2.8590250* .4220805 .000 1.25 control 6.0530250* .4220805 .000 1.5 control 1.1474000 .4220805 .054 1.75 control -.0288000 .4220805 1.000 *. the mean difference is significant at the 0.05 level. table (5): mean, standard deviation, and anova test results of hardness test related to kraft lignin wt % at different cured temperatures (40˚c, 80˚c). mean std. deviation minimum maximum hardness at cur.temp (40°c) control 78.9500 3.20260 75.20 82.70 0.5 85.1250 1.08436 83.90 86.50 1 84.5250 .84212 83.50 85.50 1.25 83.1000 1.44453 81.00 84.30 1.5 82.6250 1.13541 81.00 83.50 1.75 84.5750 .79739 83.70 85.30 hardness at cur.temp (80°c) control 84.5250 .56789 83.70 84.90 0.5 84.7250 1.65000 82.40 85.90 1 82.8250 1.51959 81.00 84.70 1.25 82.9750 3.90502 80.00 88.30 1.5 83.9000 1.61038 82.20 85.90 1.75 83.4500 2.11739 81.00 85.90 anova hardness no. sum of squares df mean square f sig. atcur.temp. (40°c) between groups 102.960 5 20.592 7.649e0 .001 at cur.temp(80°c) between groups 12.473 5 2.495 .541 .743 j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 68 table (6): multiple comparisons of hardness test at different curing temperature. dunnett t (2-sided) dependent variable (i) kraft lignin(wt%) (j) control mean difference (i-j) std. error sig. hardness at cur.temp(40°c) 0.5 control 6.17500* 1.16022 .000 1 control 5.57500* 1.16022 .001 1.25 control 4.15000* 1.16022 .009 1.5 control 3.67500* 1.16022 .022 1.75 control 5.62500* 1.16022 .001 *. the mean difference is significant at the 0.05 level. table (7): mean, standard deviation and anova test results of surface roughness related to kraft lignin wt% at deferent cured temperatures (40˚c, 80˚c). mean std. deviation minimum maximum sur.roughness at cur.temp(40c) control .27350 .021886 .242 .291 0.5 .27925 .024309 .253 .310 1 .26250 .124698 .088 .384 1.25 .10275 .060550 .061 .192 1.5 .06350 .020290 .044 .092 1.75 .12175 .045051 .081 .180 sur.roughness at cur.temp(80c) control .44750 .261082 .098 .718 0.5 .22200 .318693 .058 .700 1 .21575 .176791 .088 .465 1.25 .27700 .130468 .093 .400 1.5 .09975 .026538 .074 .135 1.75 .05532 .007156 .048 .064 anova surface roughness sum of sq. df mean sq. f sig. cur.temp. (40°c) between groups .193 5 .039 10.189 .000 cur.temp. (80°c) between groups .386 5 .077 2.120 .110 table (8): multiple comparisons of surface roughness test at different curing temperatures. dunnett t (2-sided) dependent variable (i) klwt% (j) control mean difference (i-j) std. error sig. sur.roughcur.temp(40°c) 0.5 control .005750 .043519 1.000 1 control -.011000 .043519 .999 1.25 control -.170750* .043519 .004 1.5 control -.210000* .043519 .001 1.75 control -.151750* .043519 .011 *. the mean difference is significant at the 0.05 level. discussion this in vitro study with its limitations revealed that mechanical properties of autopolymerizing resin and the modified one by kraft lignin affected by the polymerizing temperature and pressure applied during polymerization in water. the autopolymerizing acrylic resin was polymerized under pressure in water and at 40ºc. it could have improved the fracture strength of auto acrylic resin. heat may have activated the chemical reaction between the monomer and polymer components of the resin and produced almost complete polymerization. this mechanism may explain why hot water conditions improved the mechanical properties of the autopolymerizing acrylic resin, so this lead to decrease the residual monomer, this is agreed with (16,20) . the 0.5% ligninauto pmma group produced a higher transverse strength (78.0017mpa), than the conventional dental resin; however, it was statistically highly significant. this may be attributed to the method of fabrication of the modified resin samples. it was notable that the 0.5% lignin-auto pmma sample. this increase in transverse strength may be due to the more polymerization of residual monomer.) but increasing the temperature to 80°c leading to decease in the first three groups and increase in the (1.5wt%) resulted groups. this may be related to chemical composition of the resulted material, j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 69 which may be crosslinking which occurred and the bonds, may be affected by elevating heat. in the present study, pre-polymerizing two different types of polymers, methacrylate, and kraft lignin may produce a composite. kraft lignin molecule with a free carboxyl group, as this altering the structure of polymer and its properties, by creating an ionic molecule. this is agreed with park et, al., (29) the negative internal forces also affect the impact strength. this study indicated that the 0.5% lignin-autopmma group exhibited the highest transverse strength at 40°cand the 1.25wt% group had greatest impact strength at 80°c. however, the sample’s dimensions and the presence of notches, this test can result in different values of impact strength(30) increasing the polymerizing temperature had no effect on impact strength of the control group, but it affect the modified groups mostly to positive results. applying dunnett t test revealed that highly significance difference between the control and the (1.0wt%) at 40°c and (1.0 and1.25 wt%) groups at 80°c. this may be related to the more dispersion of the material and good curing when increased the temperature. the reduced results may be related to aggregation of the unreacted lignin particles, which act as stress concentration area which lead to decrease the strength. this is agreed with the (31) who studied the effect of fiber reinforcements and reported that changes in the impact and transverse strength should be due to difference in stress distribution, fiber structure, volume fraction and adherence to the matrix. the impact strength in this study less in both the control and the modified groups than that in the previous study done in air by (9). the cause may be as explained by (16) who reported that, by using hot water during polymerization, the stiffness of the material will be increased. on the other hand, heat stimulation induces the increase in contraction of the resin during polymerization (32). surface hardness of a material is its ability to resist abrasion or wear while this is measured by the material’s ability to resist indentation. in the present study, surface hardness of acrylic resins was measured using shore d hardness tester. surface hardness of a material is influenced by many factors, including surface roughness. the higher surface hardness values can be attributed to higher degree of polymerization in heat-cured acrylic resin. the high degree of residual monomer content and generalized porous surface of autopolymerized acrylic resin may contribute to its lesser value of surface hardness. (33) they found that ra of auto polymerizing resin 0.36μm when using pumice slurry and 0.10 μm when using universal polishing paste. the surface roughness is significantly reduced by polishing procedures. it has been reported that surface hardness of composite resins is influenced by both the organic matrix (monomers) and the inorganic filler. with regard to the organic matrix, hardness depends on the density and structure of the polymer formed and the degree of conversion after the polymerization(34). it is known that the presence of aromatic groups in the monomers provides a polymeric structure with higher rigidity. hardness has also been used as an indirect method to measure the degree of conversion of resin. the results have revealed increase in the hardness value in both the control and the other groups at 40°c with highly significance difference, but more increasing in the temperature not changing the values significantly. the increase in the roughness of the resin may be attributed to the stress at the filler-matrix interface. as a consequence, the filler particles located at the surface of the material would debond and the grooves created would promote the increase in the roughness, as this not observed in this study. according to bolin et, al., (35), surface roughness values higher than 0.2 μmcause microbial adhesion both in vitro and in vivo studies. although the results exhibited roughness higher than 0.2 μm, the materials evaluated in this study may be considered as materials with low roughness according to (36), once the materials’ roughness ranged from 0.7 to 3.4 μm. in the present study the lowest ra value found in 1.5 wt% lignin addition (0.063µm).increasing the temperature leading to decrease of the ra for 1.25wt% in the different temperatures. comparisons of ra values with other studies cannot be done because of differences in the experimental techniques, procedure used for polishing as well as measuring the surface roughness, and differences in the type of the materials used. the results here are lying within the range reported (37) and less. the high surface hardness in heat cured acrylic resin can be attributed to higher degree of polymerization. the high degree of residual monomer content and generalized porous surface of autopolymerized acrylic resin may contribute to its lesser value of surface hardness. this may be related to the incomplete polymerization and presence of residual monomer (33). but in this study mean that less residual monomer and higher degree of polymerization has been occurred. it appears from the literature that the roughness of dental acrylic resins is mainly j bagh college dentistry vol. 27(4), december 2015 an evaluation of restorative dentistry 70 affected by material inherent features and polishing procedures (38). the surface roughness of denture base acrylic resin depends on the processing technique viz heat cure or cold cure and the type of polishing media used (27). the polishing procedure involves gradual elimination of rough layers. this process may affect the physical properties of acrylic resin, such as surface hardness (26). on conclusions, it seems that increasing the polymerizing temperature to 40°c had appositive effect on the mechanical properties of autopolymerizing acrylic resin and the one enforced by kraft lignin biopolymer in low percentages. increasing more the polymerizing temperature to 80°c will had no much positive effect ,but it has not deteriorate the mechanical properties. so polymerization under hot-water bath and pressure results in specimens with better properties for autopolymerizing acrylic resins. references 1. vallittu pk, lassila vp, lappalainen r. evaluation of damage to removable dentures in two cities in finland. acta odontol scand 1993; 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(1) raghad fadhil, b.d.s., m.sc. (2) yasameen abdul-hussain, b.d.s., m.sc. (3) abstract background: the oral cavity is considered as a complex ecological niche, its complex microbial community is reflected to it. streptococcus mutans has been implicated as one of the major etiological factor of dental caries. tooth surfaces colonized with streptococcus mutans are at a higher risk for developing caries, while lactobacilli are considered as the secondary invaders, not initiators of the carious lesion. the main purpose of this study was to correlate the dental caries (for primary and permanent teeth) in the upper jaw with the streptococcus mutans and lactobacilli count in the dental plaque and saliva, also to correlate the dental caries (for primary and permanent teeth) in the lower jaw with the streptococcus mutans and lactobacilli count in the saliva. materials and methods: forty seven children aged 5-9 years old were selected for this study. dental caries recording was carried out by the dmfs index (decayed, missed, filled surfaces for primary teeth) to inspect the primary teeth and dmfs index (decayed, missed, filled surfaces for permanent teeth) to inspect the permanent teeth, by using the dental mirror and explorer. collection of salivary samples was performed in the morning between (10-11) a.m. at least one hour after breakfast, then normal saline was added to have tenfold dilutions, for the purpose of full colony counting of the caries related microorganisms (streptococcus mutans and lactobacilli), then inoculation was done in the special selective media (for the streptococcus mutans is mitis-salivarius-bacitracin agar, and for the lactobacilli is rogosa agar). counting of the colonies of the bacteria were estimated by the aid of dissection microscope results: the highest level of dmfs means was found in primary upper teeth, it was 17.6383 ± 10.10 while for the permanent teeth the mean of ds and dmfs was highest in the lower teeth, it was 0.7391 ± 1. pearson correlation was used to show the correlation between the ds and dmfs of upper and lower primary teeth with the level of streptococcus mutans in saliva (sm. sal) and lactobacillus in saliva ,there was a significant correlation between the ds and dmfs for upper primary teeth at level 0.01 (2-tailed), and there was negative correlation between dsl and level of streptococcus mutans in saliva (sm. sal) also there was negative correlation between dmfs for upper and lower primary teeth with level of streptococcus mutans in saliva, also the correlation between lactobacillus level in plaque with streptococcus level in plaque was negative, while for upper permanent teeth the correlation was negative with both type of bacteria level in plaque with the dsu and dmfsu conclusion: the caries activity was more prominent in upper teeth than lower teeth, levels of streptococcus mutans were not associated with high caries activity, which emphasizes and consistent with the fact that the dental caries is a multifactorial disease, related to many factors. key words: dental caries, dental plaque, saliva, streptococcus mutans, lactobacilli. (j bagh coll dentistry 2016; 28(3):132-136). introduction the oral cavity considered as a complex ecological niche, its complex microbial community is reflected to it. the human microorganisms are widely differ in types, as a result of new technology; studies estimated about 10000 types of microorganisms had been seen in the human dental plaque of 98 healthy adults (1), in return, there were lower levels of human oral microorganisms estimated by traditional methods (700 phylotypes for the oral microorganisms) (2). every site in the oral cavity, such as: mucosal sites, anaerobic pockets, and the hard dental surfaces; has its unique communities if microorganisms (3,4). (1)lecturer. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad. (2)assist. professor. department of periodontics. college of dentistry, university of baghdad. (3)pedodontist. physical and chemical fluctuation will dramatically change the ecological system of the oral cavity by the oral hygiene measures, drinks and food ingestion, in addition; lower variation in the oral microorganisms among individuals as compared with skin and gastrointestinal microorganisms (a relatively stable oral microbial community) (5). as a general fact “a shift in microbial composition is an important step in the progression of oral disease”, however; this fact is emphasized by few studies. the shift in microorganisms of the mouth is closely related to the oral hygiene. streptococcus mutans has been involved as one of the major etiological factor of dental caries (6,7). its colonization on the tooth surfaces is closely related to the development of dental caries (8). there is a positive association between streptococcus mutans levels in saliva and high j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 133 caries experience of the populations (9,10). individuals with high levels of s. mutans also develop more coronal and root caries in temporary and permanent restorations than do individuals in the same population with lower concentration of s. mutans (11,12). there is a direct relation between streptococcus mutans levels in saliva and the number of colonized tooth sites (13) and to their proportion in dental plaque.(14) lactobacilli are considered secondary invaders rather than initiators of the caries process (15). they are not found in incipient caries and are found in less quantity than streptococcus mutans (16) the presence of these micro-organisms is also depend on the size of the cavity: the larger the cavity, the more numerous bacteria (17). this study aimed to: 1. correlate the dental caries (primary and permanent teeth) in the upper jaw with the streptococcus mutans and lactobacilli count in the dental plaque and saliva 2. correlate the dental caries (primary and permanent teeth) in the lower jaw with the streptococcus mutans and lactobacilli count in the saliva. materials and methods children selected for this study were 47 aged 5-9 years. they should have active carious lesion. a subsample of 31 children was taken for the bacterial examination, from primary schools and kindergartens, and the in patients of the department of pediatric and preventive dentistry, baghdad teaching hospital for dentistry. using mouth mirror and sharp explorer , dental caries was recorded following the who 1987 criteria for primary and permanent dentition (dmfs, dmfs respectively) (18). collection of salivary samples was performed according to fejerskov and thylstrup (19) “in the morning between (10-11) a.m. at least one hour after breakfast, the children were asked to rinse out their mouths with water. after that, the first mouthful of saliva was thrown, while one ml unstimulated (resting) whole saliva was collected into small labeled plastic polyethylene tubes according to spitting method for collection. the following points should be kept in mind: 1. the patient should not eat or drink (except water) one hour before saliva collection. 2. a pre – sampling period of one minute is recommended. 3. a fixed collection time (10-15 min. for unstimulated saliva) should be used. 4. the patient should sit in a relaxed position in an ordinary chair. 5. samples containing blood should be discarded if chemical analyses of saliva are planned. after collection of the saliva, dilution was performed with normal saline in the bacteriology laboratory – college of dentistry baghdad university. after that saliva was applied on the surface of the selective media by using micropipette (mitis salivaris agar and rogosa agar medium are the selective medium for mutans streptococci and lactobacilli respectively). after incubation of the plates in an anaerobic atmosphere for 48 hours at 37°c, counting of cfu (colony forming units) with morphology characteristic of s. mutans and lactobacilli (numbers of cfu per milliliter of saliva) (20). dental plaque sample was taken by a clean toothpich from sound buccal surfaces of upper deciduous molars (the second molar; if it was not found then from the first molar). 1 ml. of normal saline in epindorf tube was used to store the sample in order not to dry. vortex mix was used to dispersion for 30 seconds. in order to see clear cfu we have to do serial dilutions by normal saline (tenfold) before inoculation in the selective media for each microorganism (for the streptococcus mutans is mitis-salivariusbacitracin agar, and for the lactobacilli is rogosa agar). by using dissection microscope 15 x, basing on the characteristic morphology, counting of the cfu was estimated (22). statistical analysis was done by using the ibm spss version 19 win 64. results the descriptive statistics was demonstrated in table 1 for decayed surfaces (ds) for upper primary teeth (dsu) and for the lower primary teeth (dsl) while the (dsu)represent the decayed surfaces for upper permanent teeth and (dsl)represent the decayed surfaces for lower permanent teeth the highest levels of dmfs means was found in upper primary teeth it was 17.6383 ± 10.10 while for the permanent teeth the mean of ds and dmfs was highest in the lower teeth, it was 0.7391 ± 1 as shown in table 1. the descriptive statistics for the colony forming units of streptococcus mutans and lactobacilli are demonstrated in table 2. pearson correlation was used to show the correlation between the ds and dmfs of upper and lower primary teeth with the level of streptococcus mutans in saliva (sm. sal) and lactobacillus in saliva too (lb.sal) as shown in table 3 and 4 .there was a significant correlation between the ds and dmfs for upper primary teeth j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 134 at level 0.01 (2-tailed), and there was negative correlation between ds.l and level of streptococcus mutans in saliva (sm. sal) also there was negative correlation between dmfs for upper and lower primary teeth with level of streptococcus mutans in saliva as shown in table 3 and 4. in table 5 the pearson correlation was used for ds for upper permanent teeth (dsu) and dmfs for upper (dmfsu) with the level of both bacteria in saliva. correlation was significant as the same for primary teeth between ds and dmfs and there was negative correlation between the level of both bacteria with dmfs for upper teeth. while in table 6 the correlation between dsl and dmfsl with both type of bacteria was positive. in table 7 the correlation between the level of lactobacillus in the dental plaque. the correlation between bacteria in plaque with the ds and dmfs was negative, also the correlation between lacto bacillus level in plaque with streptococcus level in plaque was negative as shown in table 7, while for upper permanent teeth the correlation was negative with both type of bacteria level in plaque with the dsu and dmfsu as shown in table 8. table 1: the descriptive statistics for decayed surfaces and decayed missing filling surfaces in upper and lower primary and permanent teeth n min max mean s.d. ds.u 47 4.00 41.00 15.2979 8.98287 dmfs.u 47 4.00 46.00 17.6383 10.10042 ds.l 47 .00 42.00 10.7447 8.55791 dmfs.l 47 2.00 42.00 13.5106 9.33174 ds.u 23 .00 3.00 0.4348 .78775 dmfs.u 23 .00 3.00 0.4348 .78775 ds.l 23 .00 4.00 0.7391 1.00983 dmfs.l 23 .00 4.00 0.7391 1.00983 table 2: the descriptive statistics for the colony forming units of streptococcus mutans and lactobacilli n min max mean s.d. sm.pl 31 .000 6.000 .79839 1.582728 lb.pl 31 .000 4.400 .69129 1.322076 sm.sal 31 .000 1.500 .34639 .388449 lb.sal 31 .000 2.000 .28277 .445764 table 3: pearson correlation for upper primary teeth with streptococcus and lacto bacillus bacteria ds.u dmfs.u sm.sal lb.sal ds.u r 1 .869** .039 .305 p .000 .834 .095 dmfs.u r .869** 1 -.052.136 p .000 .783 .467 sm.sal r .039 -.0521 .233 p .834 .783 .207 lb.sal r .305 .136 .233 1 p .095 .467 .207 **correlation is significant at the 0.01 level. table 4: pearson correlation for lower primary teeth with streptococcus and lacto bacillus bacteria ds.l dmfs.l sm.sal lb.sal ds.l r 1 .860** -.117.144 p .000 .530 .439 dmfs.l r .860** 1 -.098.101 p .000 .601 .588 sm.sal r -.117-.0981 .233 p .530 .601 .207 lb.sal r .144 .101 .233 1 p .439 .588 .207 ** correlation is significant at the 0.01 level. table 5: pearson correlation for upper permanent teeth with streptococcus and lacto bacillus bacteria level in saliva ds.u dmfs.u sm.sal lb.sal ds.u r 1 1.000** -.159-.346 p .000 .542 .174 dmfs.u r 1.000** 1 -.159-.346 p .000 .542 .174 sm.sal r -.159-.1591 .233 p .542 .542 .207 lb.sal r -.346-.346.233 1 p .174 .174 .207 **correlation is significant at the 0.01 level. table 6: pearson correlation for lower permanent teeth with streptococcus and lacto bacillus bacteria level in saliva ds.l dmfs.l sm.sal lb.sal ds.l r 1 1.000** .014 .112 p .000 .956 .668 dmfs.l r 1.000** 1 .014 .112 p .000 .956 .668 sm.sal r .014 .014 1 .233 p .956 .956 .207 lb.sal r .112 .112 .233 1 p .668 .668 .207 **correlation is significant at the 0.01 level. j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 135 table 7: pearson correlation for upper primary teeth with streptococcus and lacto bacillus bacteria in plaque ds.u dmfs.u sm.pl lb.pl ds.u r 1 .869** .355 -.155 p .000 .050 .404 dmfs.u r .869** 1 .331 -.050 p .000 .069 .790 sm.pl r .355 .331 1 -.018 p .050 .069 .923 lb.pl r -.155-.050-.0181 p .404 .790 .923 **correlation is significant at the 0.01 level. table 8: pearson correlation for upper permanent teeth with streptococcus and lacto bacillus bacteria in plaque ds.u dmfs.u sm.pl lb.pl ds.u r 1 1.000** -.249-.303 p .000 .335 .237 dmfs.u r 1.000** 1 -.249-.303 p .000 .335 .237 sm.pl r -.249-.2491 -.018 p .335 .335 .923 lb.pl r -.303-.303-.0181 p .237 .237 .923 **correlation is significant at the 0.01 level. discussion due to the high prevalence in all regions of the world and the greatest impact on the socially marginalized populations, oral disease is a major public health problem. therefore, the evaluation of caries risk is most important. it is mandatory to improve diet, hygiene, and preventive measures in an exposed population (23). in this study the caries activity was more prominent in upper teeth than lower teeth and this is due to the fact that the continuous pool of saliva from sublingual glands makes the teeth immune against the carious lesion by the antigens found in the saliva and by the self cleansing action of the tongue (24,25). the correlation between streptococcus level in saliva and plaque with dmfs and dmfs of upper and lower teeth was negative and this was in accordance to study done for adult individuals which report, levels of streptococcus mutans were not associated with high caries activity, “mutans streptococci have been typically considered the primary etiological agents of dental caries”, although it is still a subject to talk. in addition to its aciduric and acidogenic properties, the extracellular polysaccharide synthesis, biofilm will form from sugar constitutes which is one of the most important key virulence factors of streptococcus mutans (26). there was no difference in correlation between the cfu of both type bacteria in dental plaque and saliva which is in accordance with the result of study done by mundroff et al who proved that the number of streptococcus mutans or lactobacillus in dental plaque does not explain variation in dental caries better than the bacterial cfu in whole saliva (27). levels of streptococcus mutans were not associated with high caries activity, which emphasizes and consistent with the fact that the dental caries is a multifactorial disease and related to many factors such as: feeding at night with sweets (28), people’s lifestyle and socioeconomic status (29-31), ingestion of fermentable carbohydrates (28,30), sugar intake, presence of plaque (31,32), lack of tooth-brushing with fluoride toothpaste (33,34), lack of strict dietary control and regular oral hygiene measures (34), mother education (29), and so on. from this study we concluded that there is not one particular bacterial species responsible for caries production. the caries activity was more prominent in upper teeth than lower teeth, levels of streptococcus mutans were not associated with high caries activity, which emphasizes and consistent with the fact that the dental caries is a multifactorial disease, related to many factors. references 1. keijser bjf, zaura e, huse sm, van der vossen jmbm, schuren fhj, montijn rc, ten cate jm, crielaard w. pyrosequencing analysis of the oral microflora of healthy adults. j dent res 2008; 87:1016-20. 2. paster bj, olsen i, aas ja, dewhirst fe: the breadth of bacterial diversity in the human periodontal pocket and other oral sites. periodontol 2000 2006; 42: 80-7. 3. aas ja, paster bj, stokes ln, olsen i, dewhirst fe. defining the normal bacterial flora of the oral cavity. j clin microbiol 2005; 43:5721-32. 4. zaura e, keijser bjf, huse sm, crielaard w. defining the healthy "core microbiome" of oral microbial communities. bmc microbiol 2009; 9: 259. 5. costello ek, lauber cl, hamady m, fierer n, gordon ji, knight r. bacterial community variation in human body habitats across space and time. sci 2009; 326:1694-7. 6. hamada s, slade hd. biology, immunology and cariogenicity of streptococcus mutans. microbiol rev 1980; 44: 331–84. 7. loesche wj. the role of streptococcus mutans in human dental decay. microbiol rev 1986; 50: 353–80. 8. loesche wj, eklund s, earnest r, burt b. longitudinal investigation of bacteriology of human fissure decay; epidemiological studies in molars shortly after eruption. infect immun 1984; 46: 765–72. 9. emilson cg, krasse b. support for an implication of the specific plaque hypothesis. scand j dent res 1985; 93: 96–104. 10. koga-ito cy, martins ca, balducci i, jorge ao. correlation among mutans streptococci counts, dental j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 136 caries, and iga to streptococcus mutans in saliva. braz oral res 2004; 18: 350–5. 11. thenisch nl, bachmann lm, imfeld t, leisebach mt, steurer j. are mutans streptococci detected in preschool children a reliable predictive factor for dental caries risk? a systematic review. caries res 2006; 40: 366–74. 12. preza d, olsen i, aas ja, willumsen t, grinde b, paster bj. bacterial profiles of root caries in elderly patients. j clin microbiol 2008; 46: 2015–21. 13. togelius j, kristoffersson k, andersson h, bratthall d. streptococcus mutans in saliva: intra-individual variations and relation to number of colonized sites. acta odontol scand 1984; 42: 157–63. 14. lenander-lumikari m, loimaranta v. saliva and dental caries. adv dent res 2000; 14: 40–7 15. tanzer jm, livingston j, thompson am. microbiology of primary dental caries in humans. j dent educ 2001; 65:1028–37 16. ayna b, celenk s, atakul f, sezgin b, ozekinci t. evaluation of clinical and microbiological features of deep carious lesions in primary molars. j dent child 2003; 70(1):15–8. 17. bonecker m, grossman e, cleaton-jones pe, parak r. clinical histological and microbiological study of hand-excavated carious dentine in extracted permanent teeth. sadj 2003; 58: 273–8. 18. who. oral health surveys: basic methods. 3rd ed. geneva, switzerland. 1987. 19. fejerskov o, thylstrup a. the oral environment and introduction. textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1994; p.13-17. 20. kishi m, abe a, kishi k, ohara-nemoto y, kimura s, yonemitsu m. relationship of quantitative salivary levels of s. mutans and s. sorbinus in mothers to caries status and colonization of mutans streptococci in plaque in their 2.5 year-old children. community dent oral epidemiol 2009; 37: 241-9. 21. krishnakumar r, singh s, subba reddy vv, et al. comparison of level of mutans streptococci and lactobacilli in children with nursing bottle caries rampant caries, healthy children with 3-5 dmft/dmft and healthy caries free children. j indian soc pedo prev dent 2002; 20: 1-5. 22. kishi m, abe a, kishi k, ohara-nemoto y, kimura s, yonemitsu m. relationship of quantitative salivary levels of s. mutans and s. sorbinus in mothers to caries status and colonization of mutans streptococci in plaque in their 2.5 year-old children. community dent oral epidemiol 2009; 37: 241-9, 23. luo y, mcgrath c. oral health status of homeless people in hong kong. spec care dentist 2006; 26:150–4. 24. welbury r, duggal m. paediatric dentistry. 3rd ed. oxford: oxford university press; 2005. p.147 25. millett d, welbury r. clinical problem solving in orthodontics and paediatric dentistry. st. louis: elsevier/churchill livingstone; 2005. p.83 26. giacaman ra, araneda e, padilla c. association between biofilm-forming isolates of mutans streptococci and caries experience in adults. arch oral biol 2010; 55: 550–4. 27. mundroff sa, eisenberg ad, leverett dh, espeland ma, proskin hm. correlation between the number of microflora in plaque and saliva .caries res 1990; 24: 312-7. 28. slabšinskienė e, milčiuvienė s, narbutaitė j, et al. severe early childhood caries and behavioral risk factors among 3-year-old children in lithuania. medicina (kaunas) 2010; 46:135-41 29. dini el, holt rd, bedi r. caries and its association with infant feeding and oral health-related behaviours in 3-4-year-old brazilian children. community dent oral epidemiol 2003; 28: 241-8. 30. moura l de f, de moura ms, de toledo oa. dental caries in children that participated in a dental program providing mother and child care. j appl oral sci 2006;14(1): 53-60 31. jose b, king nm. early childhood caries lesions in preschool children in kerala, india. pediatr dent 2003; 25: 594-600. 32. wang wh, wang wj. caries-related factors for preschool children. zhonghua kou qiang yi xue za zhi 2008; 43:105-6. 33. weerheijm kl, uyttendaele-speybrouck bf, euwe hc, groen hj. prolonged demand breast-feeding and nursing caries. caries res 1998; 32: 46-50. 34. slabsinskiene e, milciuviene s, narbutaite j, vasiliauskiene i, andruskeviciene v, bendoraitiene ea, saldūnaite k. severe early childhood caries and behavioral risk factors among 3-year-old children in lithuania. medicina (kaunas) 2010; 46:135-41. 28bayda'a f.doc j bagh college dentistry vol. 28(3), september 2016 tooth wear in pedodontics, orthodontics and preventive dentistry 167 tooth wear in relation to selected salivary variables among a group of older adults baydaa ahmed yas, b.d.s., m.sc. (2) abstract background: tooth wear is one of the most concerning problems of the current dental practice especially among older subjects. the aim of this study is to determine the severity of tooth wear and its relation with selected salivary variables (salivary ph and vitamin c level) among a group of older adults in mosul city/iraq. materials and methods: all subjects (30 subjects) of both gender tookpart in the current study; sixteen of them were older adults (55-65 years) and compared with fourteen middle-aged adults (30-40 years) at textile factory in mosul city/iraq. unstimulated salivary samples were collected and salivary ph was immediately measured. salivary vitamin c level was determined colormetrically. severity of tooth wear was determined according to hansson and nilner (1975) classification. results: results showed that all severity scores of tooth wear revealed higher percentage among older adults than middle-aged adults. also all tooth segment types revealed higher percentage of tooth wear among older adults than middle-aged adults. moreover regarding the highest score of tooth wear by subjects, higher percentage of tooth wear was found among older adults than middle-aged adults. concerning the total sample results disclosed that wear of enamel only revealed higher percentage than one or more teeth worn into dentine and one or more teeth worn up to 1/3 of the crown. also in the total sample the incisor region showed higher percentage of tooth wear while the least tooth wear percentage was found in the molar region. in both age groups no significant correlations were found between salivary ph and vitamin c with the highest score of tooth wear. conclusion: tooth wear is more severe among older subjects. further study is needed with larger sample size and more precise index that measure the etiology of tooth wear. key words: tooth wear, salivary ph, salivary vitamin c level. (j bagh coll dentistry 2016; 28(3):167-171). introduction tooth wear is non-carious irreversible loss of tooth structure and it is the fourth dimension risk factor for esthetic, function and longevity of human dentition after acute trauma, caries and periodontal disease (1). tooth wear is a multifactorial process and depending on its cause it appears in several forms that include attrition (loss of dental hard tissues as a result of tooth to-tooth contact during normal or parafunctional masticatory activity without the intervention of foreign substance) (2-4), abrasion (pathological wear of dental hard tissues through abnormal bio-mechanical frictional processes, in other words it involves foreign objects that are repeatedly introduced to the mouth and contact teeth), erosion (loss of dental hard tissues by chemical dissolution of enamel and dentin through the action of non-bacterial acid from dietary or gastric sources) (5), and abfraction (is loss of dental hard tissues from eccentric occlusal forces leading to compressive and tensile stresses) (4). tooth wear could be physiological or pathological. physiological one is normal process that is incremental with age and is macroscopically irreversible (6). whereas pathological tooth wear is severe degree of tooth loss that is disproportionate for individual age (3). (1)assist. professor. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad the composition of saliva, dietary habits, digestive disturbances and environmental pollutants all were found to influence tooth wear (7-9). saliva is the most relevant biological factor for the prevention of tooth wear especially dental erosion (10). it acts through its flow rate that helps in diluting and clearing acids, buffering system, formation of the acquired pellicle that prevents the contact of acids with the tooth surfaces, and also through mineral content saliva can prevent demineralization and enhance remineralization (11,12). however, saliva produced at low flow rates presents low ph and a reduced buffering capacity (13) that increases the risk of dental erosion as reported by other studies (14-16). vitamin c is considered as deminerlizing agent and leads to significant tooth wear if its consumption is frequent and prolonged (17,18) since chewable vitamin c tablets have been reported to have a ph of 2.3 that is lower than the critical point (5.5) at which enamel dissolves (19). meurman and murtomaa (20) found that vitamin c products caused distinct erosion and disclosure of dentine in specimens (bovine tooth specimens immersed for 100 hr in 100 ml of the test vitamin c solutions). also touyz (21) found that excessive consumption of fruit juices lead to dental erosion, attrition, and dentinal hypersensitivity. several studies have been done around the world on tooth wear with wide age range (22-25). in iraq few studies have been carried out among children to investigate tooth attrition and its j bagh college dentistry vol. 28(3), september 2016 tooth wear in pedodontics, orthodontics and preventive dentistry 168 relation with tempromandiular joint problems and other risk factors (26-28). only one iraqi study could be found conducted among older adults (50-89 years) to determine the prevalence and severity of tooth wear and its relation to tempromandiular joint problems and other selected risk factors (29). according to the mentioned above it was decided to conduct this study among a group of older adults (55-65 years) in mosul city/iraq to determine the severity of tooth wear and its relation with selected salivary variables (salivary ph and vitamin c level) in comparison to 30-40 year-old adults. in addition to determine the severity of tooth wear according to tooth type. materials and methods the study participants consisted of all subjects (30 subjects) of both genders who fitted the criteria of the study at textile factory in mosul city. sixteen of them were older adults aged 55-65 years and compared with fourteen middle-aged adults aged 30-40 years. they were examined in the period from 26th of march 2007 till the end of june 2007. they were non-smoker, with no medical history that compromises salivary secretary mechanism (depending on medical report supplied by the medical unit at the factory), shouldn’t take any medications with xerogenic effect or any nutritional supplementation, and shouldn’t wear any fixed or removable dental prostheses. the collection of unstimulated salivary samples was performed according to the instructions cited by tenovuo and lagerlöf (30). salivary ph was immediately measured using an electronic ph meter. then salivary samples were taken to the laboratory for biochemical analysis at the college of veterinary and college of dentistry, university of mosul. salivary vitamin c was determined colometrically using 2,4-dinitrophenyl hydrazine (dnph) method (31) by using the spectrophotometer (cecil instrument limited ce 1021, england). the severity of tooth wear was determined according to hansson and nilner (1975) (32) classification: 0=no wear. 1=wear of enamel only. 2=one or more teeth worn into dentine. 3=one or more teeth worn up to 1/3 of the crown. 4=extensive wear of one or more teeth more than 1/3 of the crown. data analysis was conducted through the application of the spps (version 18). statistical tests used in this study are: fisher's exact test and spearman's correlation coefficient (r). the confidence limit was accepted at 95% (p<0.05). results distribution of the total sample by age group and gender is shown in table 1. from table 2 results showed that all scores of tooth wear severity (wear of enamel only, one or more teeth worn into dentine, and one or more teeth worn up to 1/3 of the crown) were higher among older adults than middle-aged adults in whom score 3 (one or more teeth worn up to 1/3 of the crown) was completely absent. in addition in the total sample wear of enamel only revealed higher percentage (55.77%) than one or more teeth worn into dentine (38.46%) and one or more teeth worn up to 1/3 of the crown (5.77%). only one or more teeth worn into dentine severity score showed significant association with age (p<0.05). it is worth to mention that extensive wear of one or more teeth more than 1/3 of the crown was not found in both age groups. concerning segment type (table 3) results showed that all segment types revealed higher percentage of teeth with wearing among older adults as compared with middle-aged adults. in the total sample the incisor region showed higher percentage of tooth wear (32.61%) while the least tooth wear percentage was in the molar region (10.87%). also results showed that there is highly significant (p<0.01) association between tooth wear and age in the molar region. regarding the distribution of the subjects with highest score of tooth wear, table 4 revealed that wear of enamel only showed higher percentage among middleaged adults (80%) than older adults (20%), while one or more teeth worn into dentine (score 2) and one or more teeth worn up to 1/3 of the crown (score 3) were higher among older adults (64.71%, 100% respectively) than middle-aged adults (35.29%, 0.00% respectively). also the highest score of tooth wear showed significant association with age (p<0.05). table 5 showed that in both age groups no significant correlations were found between salivary ph and vitamin c with the highest score of tooth wear (p>0.05). j bagh college dentistry vol. 28(3), september 2016 tooth wear in pedodontics, orthodontics and preventive dentistry 169 table 1: distribution of the total sample by age group and gender gender age group total middle-aged adults older adults no. % no. % no. % male 7 50 13 81.25 20 66.67 female 7 50 3 18.75 10 33.33 total 14 100 16 100 30 100 table 2: frequency distribution of tooth wear scores according to severity of tooth wear by age group age group wear of enamel only one or more teeth worn into dentine one or more teeth worn up to 1/3 of the crown no. % no. % no. % middle-aged adults 14 48.28 6 30 0 0 older adults 15 51.72 14 70 3 100 total 29 55.77 20 38.46 3 5.77 fisher's exact test 0.91 6.70 2.92 df 1 1 1 p-value 1.00 0.019* 0.23 *significant table 3: frequency distribution of tooth wear scores according to segment type by age group age group incisors canines premolars molars no. % no. % no. % no. % middle-aged adults 14 46.67 11 40.74 10 40 0 0 older adults 16 53.33 16 59.26 15 60 10 100 total 30 32.61 27 29.35 25 27.17 10 10.87 fisher's exact test 3.81 2.68 14.25 df 1 1 1 p-value 0.09 0.16 0.00** **highly significant table 4: frequency distribution of subjects according to the highest score of tooth wear by age group age group wear of enamel only one or more teeth worn into dentine one or more teeth worn up to 1/3 of the crown total no. % no. % no. % no. % middle-aged adults 8 80 6 35.29 0 0 14 46.67 older adults 2 20 11 64.71 3 100 16 53.33 total 10 33.33 17 56.67 3 10 30 100 fisher's exact test 7.97 df 2 p-value 0.017* *significant table 5: relation of the highest score of tooth wear (by subjects) with salivary ph and vitamin c level by age group. age group tooth wear salivary ph vitamin c r p-value r p-value middle-aged adults highest score 0.21 0.47 -0.26 0.38 older adults highest score -0.47 0.07 -0.03 0.92 j bagh college dentistry vol. 28(3), september 2016 tooth wear in pedodontics, orthodontics and preventive dentistry 170 discussion there is a wide range of tooth wear indices and a universally applicable tooth wear measuring system is still lacking. in addition variation of the diagnostic criteria, sampling technique and age range differences; all makes comparison of results among studies very difficult (33-35). results of the current study showed that wear of enamel only, one or more teeth worn into dentine and one or more teeth worn up to 1/3 of the crown revealed higher percentages among older adults than middle-aged adults. also segment types (incisors, canines, premolars and molars) showed higher percentage of tooth wear among older adults compared with middle-aged adults. this is further supported by another finding of this study which showed that the percentage of subjects (with highest score of tooth wear) with one or more teeth worn into dentine and one or more teeth worn up to 1/3 of the crown was higher among older adults than middle-aged adults. this is probably because tooth wear is an accumulative process throughout life and it is an age-related phenomenon (36,37). the increased teeth exposure to environmental factors (local or systemic, erosive, attritive, or abrasive factors) may cause more tooth wear rather than age per say (38). this finding was inconsistent with al-azawi study (29). regarding the total sample results revealed that wear of enamel only showed higher percentage while extensive wear of one or more teeth more than 1/3 of the crown didn’t found in the current sample this is probably because physiological rather than pathological tooth wear is more prevalent in old age people (39). also results showed that the incisor region showed higher percentage of tooth wear followed by canines and premolars while molar region revealed the least percentage. this is probably because the incisor or anterior region may be affected by personal habits (cigarette or pipe smoking) or occupational habits (holding pins or nails in the mouth), also canines are used for tearing and biting, thus showed more severe tooth wear while premolars and molars are used for chewing only (40,41). in addition non-dietary uses of anterior teeth and thin incisal edges compared to occlusal surfaces of posterior teeth all decrease the risk of posterior teeth wear but increase the chance of anterior teeth wear (42, 43). moreover location of the incisors and canines in the oral cavity predisposed them to erosive factors like extrinsic acids (44). this result was nearly the same to that found by mohammad and garib (35) and saerah et al (34) studies who found that the incisal edges were the mostly affected surfaces, but contradicted with david and bhat (45) and alazawi (29) findings who found that canines were the mostly affected teeth by tooth wear than incisors. in spite of there is no index that could diagnose the causes of tooth wear separately 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pervasive condition. j esth res dentistry 2011; 23(4): 205-216. 18. rathee m, bhoria m, renu k. vitamin c and oral health: a review. indian j applied res 2013; 3(9): 462-463. 19. blacker sm, chadwick rg. an in vitro investigation of the erosive potential of smoothies. br dent j 2013; 214(4): 9. 20. meurman jh, murtomaa h. effect of effervescent vitamin c preparations on bovine teeth and on some clinical and salivary parameters in man. scand j dent res 1986; 94(6): 491-9. 21. touyz lz. the acidity (ph) and buffering capacity of canadian fruit juice and dental implications. j can dent assoc 1994; 60(5): 454-8. 22. hugoson a, bergendal t, ekfeldt a, helkimo m. prevalence and severity of incisal and occlusal tooth wear in an adult swedish population. acta odontol scand 1988; 46: 255-65. 23. poynter me, wright ps. tooth wear and some factors influencing its severity. restorative dent 1990; 6(4): 8-11. 24. taiwo jo, ogunyinka a, onyeaso co, dosumu oo. tooth wear in the elderly population in south east local government area in ibadan, nigeria. odontostomatol trop 2005; 28(112): 9-14. 25. ibiyemi o, ifeoluwa oo, juliana ot, gbemisola ao. oral habits and tooth wear lesions among rural adult males in nigeria. arch orofac sci 2010; 5(2): 31-5. 26. saeed wk. bruxism and related factors among 5-14 years old in baghdad city. a master thesis, college of dentistry, university of baghdad; 1998. 27. al-obaidi wa, rassim wf. dental attrition in relation to temporomandibular joint problem. iraqi dent j 2002; 30: 231-8. 28. al-obaidi wa, ghafour sm. prevalence of dental attrition among (5-11) year-old children in albu-etha village (baghdad). j coll dent 2005; 17(1): 105-7. 29. al-azawi mg. tooth wear in relation to temporomandibular joint disorders and other selected risk factors among institutionalized older adults in baghdad city/ iraq (cross-sectional study). a master thesis, college of dentistry, university of baghdad; 2013. 30. tenovuo j, lagerlof f. saliva. in: thylstrup a and fejerskov o (eds). textbook of clinical cariology. 2nd ed. copenhagen: munksguard; 1994. p. 17-43. 31. colowick sp, kaplan no. methods in enzymology. vol.62, part d, academic press, usa; 1979.p. 7. 32. hansson a, nilner m. a study of the occurrence of symptoms of diseases of temporomandibular joint, masticator masculator and related structure. j oral rehabil 1975; 2: 313-20. 33. bardsley pf, taylor s, milosevic a. epidemiological studies of tooth wear and dental erosion in 14-yearold children in north west england. part 1: the relationship with water fluoridation and social deprivation. br dent j 2004; 197(7): 413-6. discussion 399. 34. saerah nb, ismail nm, naig l, ismail ar. prevalence of tooth wear among 16-year old secondary school children in kota bharu kelantan. arch orofacial sci 2006; 1: 21-8. 35. mohammad dn, garib bt. the prevalence of tooth wears among (18-25) years old college students in sulaimani city. j zankoy sulaimani-part a (jzs-a) 2012; 14(1): 1-5. 36. bernhardt o, gesch d, splieth c, schwhan c, mack f, kocher t, meyer g, jhon u, kordass b. risk factor for high occlusal wear scores in a populationbased sample: results of study of health in pomerania (ship). int j prosthodont 2004; 17(3): 333-9. 37. arnadottir ib, holbrook wp, eggertsson h, gudmundsdottir h, jonsson sh, gudlaugsson jo, saemundsson sr, eliasson st, agustsdottir h. prevalence of dental erosion in children: a national survey. community dent oral epidemiol 2010; 38: 521-6. 38. hamudi z. genetic and environmental influences on variation in overbite, overjet, and tooth wear. degree of doctor thesis, university of adelaide; 2011. 39. cunha-cruz j, pashova h, packard jd, hilton t. tooth wear prevalence and associated factors in private practice patient. jadr 2008. 40. bass, william m. human osteology: laboratory and field manual, 4th ed. special publication no.2. columbia: missouri archaeological society; 1995. 41. white, tim d. human osteology. 2nd ed. new york: academic press; 2000. p. 55. 42. hobkirk ja. tooth surface loss: causes and effects. int j prosthodont 2007; 20(4): 340-1. 43. nico hjc, arie vs. tooth wear and occlusion. friends and foes? int j prostho 2007; 20: 348-50. 44. wiegand a, muller j, werner c, attin t. prevalence of erosive tooth war and associated risk factors in 2-7 year old german kindergarten children. oral diseases 2006; 12: 117-24. 45. david k, bhat km. prevalence of tooth wear in patients attending the department of periodontics, manipal college of dental sciences. manipal njirm 2012; 3(2): 136-41. 46. bartlett dw, evans df, anggiansah a, smith bg. the role of esophagus in dental erosion. oral surg oral med oral pathol oral radiol endod 2000; 89(3): 312-5. dunia final.doc j bagh college dentistry vol. 26(2), june 2014 assessment of dental orthodontics, pedodontics and preventive dentistry 138 assessment of dental arches symmetry in a sample of iraqi children at the mixed dentition stage dunia ahmed aldulayme, b.d.s., m.sc. (1) abstract background: little is known about asymmetry of children's dental arches, the purpose of this study was to verify the presence of asymmetry of dental arches among iraqi children in the mixed dentition stage. materials and methods: the sample included 52 pairs of dental casts, 27 pairs belong to males and 25 pairs for females. three linear distances were utilized on each side on the dental arch: incisal-canine distance, canine-molar distance and incisal-molar distance, which represent the dental arch segmental measurements using the digital sliding calipers, which is accurate up to 0.02 mm. results: no significant sides' differences with high correlation coefficient were found between the right and left incisal-canine, canine-molar and incisal-molar distances in both dental arches for both genders with males exhibited higher mean values than females in all segmental measurements of the dental arches. conclusion: the findings of the present study revealed the symmetrical pattern of dental arches, since statistically the right and left sides showed no significant difference with high correlation coefficient in all measuring segments. key words: dental arch, asymmetry, mixed dentition. (j bagh coll dentistry 2014; 26(2): 138-143). introduction although each person shares with the rest of the population a great many characteristics, there are enough differences to make each human being a unique individual. variations in the size, shape and relationship of the dental, skeletal and soft tissue facial structures are important in providing each individual with his or her own identity (1). stedman's medical dictionary defined symmetry as "equality or correspondence in form of parts distributed around a center or an axis, at the two extremes or poles, or on the two opposite sides of the body" (2). dental arch asymmetry can be caused by a combination of genetic (1,3) and environmental (3) factors, with skeletal, dental or functional repercussions (1). in individuals with symmetric development, the slight differences between the right and left sides may be due to external environmental factors such as: thumb sucking, unilateral chewing, loss of contact due to cavities, extraction or trauma (3). children can also feature asymmetric dental arches (4) and older individuals tend to have greater arch asymmetry, resulting from lifelong external environmental factors (5). it is rare to find a totally symmetric individual; therefore, small asymmetries are regarded as normal (6). most individuals with normal occlusion may show almost coinciding midlines (deviation smaller than 1 mm), and many can have molar asymmetry greater than 1 mm in transversal and anteroposterior directions (7). dental midline deviations greater than 2 mm are easily detected by lay persons, and should therefore be considered when planning orthodontic treatments (8). (1)lecturer. department of pedodontics, orthodontics and preventive dentistry, college of dentistry, al-mustansiria university. dental arch asymmetry is a common finding in normal (orthodontically untreated) children (1), but during the mixed dentition, environmental factors may account better for asymmetry because growth and developmental changes are accelerated after the relatively stable period of the deciduous dentition (4,9). however little is known about dental arch asymmetries in children at the mixed dentition stage, so early diagnosis and treatment of dental arch asymmetry could minimize the need for complex treatment mechanics or asymmetric extractions (10). most studies of dento-alveolar asymmetry have used dental models and most often only the maxillary arch using the median raphe as an axis of symmetry. some of these studies reported some degree of dental arch symmetry even in persons with normal occlusion (3,11). hechter (12) analyzed asymmetry of the dental arches in normal and malocclusion subjects and reported greater asymmetry in the mandibular arch for both groups. in addition he found an increase in asymmetry in both arches when malocclusion was present. adults with missing teeth tend to be more asymmetric than adults with intact dentitions (5). the purpose of this study was to assess the dental arches asymmetry in a sample of iraqi children at the mixed dentition stage. materiels and methods sample the sample consisted of (52) iraqi children aged 8-9 years at the mixed dentition stage (27 males and 25 females) selected from different primary schools from baghdad city. the inclusion criteria of the sample selection were the presence of all the permanent first molars, permanent central and lateral incisors, j bagh college dentistry vol. 26(2), june 2014 assessment of dental orthodontics, pedodontics and preventive dentistry 139 deciduous canine, first and second deciduous molars. while the exclusion criteria were chosen to minimize variables influencing asymmetry such as; history of orthodontic treatment or space maintenance, visually apparent inter-proximal caries, history of primary molar or canine extractions, history of dental trauma, restorations or fractures that included the incisal edges of the permanent central incisors, digit habits past the age of 3 years, ectopically erupting first molars, evidence of a syndrome or craniofacial malformation or obvious facial asymmetry . methods each child was seated on dental chair in upright position asked information about name, age, origin, history of previous orthodontic treatment, maxillofacial surgery and extensive restorative dental treatment. then they were clinically examined to check their fulfillment for the selection criteria and data recording case sheet was filled for every child. upper and lower impressions were taken with a perforated metal orthodontic trays using alginate hydrocolloid impression material (13). alginate impressions were poured with stone within 1 hour and a base was constructed for each cast using plaster of paris. casts were trimmed and numbered for each child. certain selected tooth-related points visible in an occlusal view were marked bilaterally with a sharp pencil in the maxillary and mandibular study casts. great care was taken to ensure that the landmarks were accurately located on the study casts. three segments on the maxillary and mandibular dental arch were measured using the digital sliding calipers with 0.02 mm. accuracy. the measurements included (figure 1): a. incisal-canine distance (incd): right and left linear distance from the incisal point to the canine cusp tip. b. canine-molar distance (cmd): right and left linear distance from the canine cusp tip to the disto-buccal cusp tip of the first permanent molar. c. incisal-molar distance (inmd): right and left linear distance from the incisal point to the disto-buccal cusp tip of the first permanent molar. figure 1: measurements used in this study on the maxillary and mandibular arches statistical analysis the statistical analyses included the descriptive statistics (means, standard deviations, minimum, maximum, range) and the inferential statistics (paired sample t-test to compare between the right and left sides, pearson's correlation coefficient to test the relation between both sides and independent sample t-test for comparison between the males and females). results the results in table 1 showed the descriptive statistics of the maxillary dental arch segmental measurements. generally, male group displayed higher mean values than female group in all measurements. on the other hand, table (2) showed the descriptive statistics of the mandibular dental arch segmental measurements for both genders and also the males recorded higher mean values than females in all measuring distances. side difference as shown in tables 3 and 4, there were no significant differences between the right and left incisor-canine distance (incd), canine-molar distance (cmd) and incisor-molar distance (inmd) for both genders and dental arches. correlation between the right and left sides the findings in tables 3 and 4 revealed the presence of high significant correlation between right and left sides of maxillary and mandibular segmental measurements (incd, cmd and inmd) for both genders. j bagh college dentistry vol. 26(2), june 2014 assessment of dental orthodontics, pedodontics and preventive dentistry 140 table 1: descriptive statistics of maxillary segmental measurements (in mm.) in both genders inmd cmd incd statistics genders left right left right left right 44.91 44.59 27.38 27.46 19.81 20.04 mean males 50.23 48.38 31.09 30.82 22.45 23.10 max. 41.00 34.85 24.44 23.90 17.65 17.06 min. 2.10 2.86 1.42 1.39 1.07 1.26 sd 43.24 43.27 26.91 26.97 18.69 18.87 mean females 45.45 45.40 28.51 28.88 20.20 20.60 max. 40.47 39.93 24.40 24.75 17.46 17.40 min. 1.25 1.37 1.00 1.03 0.69 0.83 sd table 2: descriptive statistics of mandibular segmental measurements (in mm.) in both genders inmd cmd incd statistics gender left right left right left right 39.72 39.65 28.08 28.08 14.57 14.45 mean males 41.92 41.94 30.24 30.48 16.05 15.88 max. 37.20 36.20 25.14 25.10 13.16 13.11 min. 1.47 1.56 1.12 1.14 0.78 0.84 sd 38.53 38.50 27.67 27.71 13.89 13.81 mean females 40.39 40.50 28.80 29.13 16.07 16.42 max. 36.08 36.15 25.70 25.50 12.84 12.70 min. 1.12 1.23 0.75 0.96 0.78 0.79 sd table 3: paired sample t-test and correlation between right and left sides of maxillary dental arch segmental measurements for both genders genders dimensions right left pvalue significance pvalue of correlation coefficient significance males incd 20.04 19.81 0.49 ns 0.00 hs cmd 27.46 27.38 0.84 ns 0.00 hs inmd 44.59 44.91 0.64 ns 0.00 hs females incd 18.87 18.69 0.41 ns 0.00 hs cmd 26.97 26.91 0.84 ns 0.00 hs inmd 43.27 43.24 0.95 ns 0.00 hs ns: non-significant (p > 0.05), hs: highly significant (p < 0.01) table 4: paired sample t-test and correlation between right and left sides of mandibular dental arch segmental measurements for both genders genders dimensions right left pvalue significance pvalue of correlation coefficient significance males incd 14.45 14.57 0.58 ns 0.00 hs cmd 28.08 28.08 0.99 ns 0.00 hs inmd 39.65 39.72 0.86 ns 0.00 hs females incd 13.81 13.89 0.72 ns 0.00 hs cmd 27.71 27.67 0.85 ns 0.00 hs inmd 38.50 38.53 0.95 ns 0.00 hs ns: non-significant (p > 0.05), hs: highly significant (p < 0.01) genders differences as there were non-significant differences between right and left sides, the data were collected together and represented as maxillary and mandibular segmental dimensions for male and female groups which were represented in tables 5 and 6. independent sample t –test showed significant difference in all maxillary and mandibular segmental measurements with higher mean values in males than females (tables 5 and 6). j bagh college dentistry vol. 26(2), june 2014 assessment of dental orthodontics, pedodontics and preventive dentistry 141 table 5: descriptive statistics and genders difference of the maxillary segmental measurements p-value range min. max. sd mean gender dimensions 0.000 hs 6.04 17.06 23.10 1.166 19.92 males incd 3.20 17.40 20.60 0.764 18.78 females 0.05 s 7.19 23.90 31.09 1.398 27.42 males cmd 4.48 24.40 28.88 1.011 26.94 females 0.000 hs 15.38 34.85 50.23 2.496 44.75 males inmd 5.52 39.93 45.45 1.300 43.25 females s: significant (p < 0.05), hs: highly significant (p < 0.01) table 6: descriptive statistics and genders difference of the mandibular segmental measurements p-value range min. max. sd mean genders dimensions 0.00 hs 2.94 13.11 16.05 0.809 14.51 males incd 3.94 12.48 16.42 0.783 13.85 females 0.05 s 5.38 25.10 30.48 1.127 28.08 males cmd 3.63 25.50 29.13 0.859 27.69 females 0.00 hs 5.74 36.20 41.94 1.505 39.69 males inmd 4.42 36.08 40.50 1.169 38.52 females s: significant (p < 0.05), hs: highly significant (p < 0.01) discussion few studies have quantified dental arch asymmetry in children, although asymmetry is reported frequently in adults (4), so the proper diagnosis of asymmetries whether skeletal, dental, or a combination of both is extremely important in order to address the origin of the problem during treatment. in the present study, an investigation of model analysis attempted to identify and analyze asymmetry in the dental arch segmental measurements at the mixed dentition stage among sample of iraqi children aged 8-9 years from different primary schools in baghdad city. although each ethnic group has certain characteristics that should not be taken as standards for other areas with the different developmental and ecological foundation (14) , the study and determination of criterion for different ethnic groups is essential to promote accurate diagnosis and planning for orthodontic treatment. in this study, fixed reproducible control points were selected, which were called the "print" of the arch form as any finger has its unique print, also each arch form has its unique print, the print of the arch form will be presented by the buccal cusp tips and the incisal edges of anterior teeth; in addition, using tooth-related points are less subjected to error when measured more than the alveolar points, which may be affected by the distortion of the gingiva owing to the fit or position of the impression trays. besides, measurements that taken from a definite cusp tips to a corresponding definite cusp tip are very reliable (15,16). it is obvious from tables 1 and 2 that the mean values of all maxillary measurements taken for the dental arch segments are larger than that in the mandibular counterpart (15,17-20); this is consistent with the principle that the maxillary dental arch overlaps the mandibular dental arch. dental arch asymmetry (right and left comparison) in the present study, when the mean values of the right and left incisal-canine, canine-molar and incisal-molar distances were compared using paired sample t-test which showed non-significant differences in both arches and for both genders indicating the symmetrical pattern of maxillary and mandibular dental arches (14,20). sawiris (21) measured the buccal segment from canine cusp tip to the disto-buccal cusp tip of second molar of 50 british subjects with class i occlusion and reported that the right side was larger by (0.24 mm.). correlation between right and left sides of dental arches it can be noted that there are high values of correlation coefficient of the relationship between all right and left segmental measurements in both maxillary and mandibular dental arches for both genders (tables 3 and 4). these results give an impression that the dental arches, despite their forms are proportioned in this plane. these proportioned measurements might be attributed to the fact that the teeth are positioned within the alveolar bone which is affected by the dental base, which it rests on (22), this result coincides with j bagh college dentistry vol. 26(2), june 2014 assessment of dental orthodontics, pedodontics and preventive dentistry 142 previous studies (23,25) and contradicts with others (26). genders difference in this study, the mean values of dental arch segments are larger in males than that of females (tables 5 and 6) with a high significant difference in the incisor-canine and incisor-molar distances and significant difference in the canine-molar distance in both arches. in most studies, the arch dimensions depended on the gender of the subjects, with smaller values in females (14,20,27). generally, the dental arches in males grow larger and for longer time than in females during both the preadolescent and adolescent periods (23,24). however, differences between females and males were shown not to be systematic across all studies (15,28,29). another finding observed from table 5, that the widest range of reading was in the longest distance measured which is the incisor-molar distance in the maxillary arch in the male group about (15.38 mm.) with high standard deviation about (2.496 mm.); this may be attributed to the midline diastema (ugly duckling stage) in the maxillary arch along with the overlapping of permanent lateral incisors which appear at the age 8-9 years and persist 3-4 years (30), and recorded only in male group may be because the eruption time in female an average approximately 5 months earlier than males (31). as conclusions; 1. there were no significant sides' differences with high correlation coefficient both in maxillary and mandibular segmental measurements which indicate the symmetrical pattern of the dental arches for both male and female sample. 2. male sample possesses higher mean values in all segmental measurements than the female sample. 3. maxillary segmental dimensions show higher values than the mandibular. references 1. bishara se, burkey ps, kharouf jg. dental and facial asymmetries, a review. angle orthod 1994; 64: 8998. 2. stedman's medical dictionary, baltimore, the williams and wilkins company; 1966. 3. lundstrom a. some asymmetries of dental arches, jaws, and skull, and their etiological significance. am j orthod 1961; 47(2): 81-106. 4. maurice tj, kula k. dental arch asymmetry in the mixed dentition. angle orthod 1998; 68(1): 37-44. 5. smith r, bailit h. prevalence and etiology of asymmetries in occlusion. angle orthod 1979; 49(3):199-204. 6. ferrario vf, sforza c, miani a, d'addona a. position and asymmetry of teeth in untreated dental arches. int j adult orthod orthognath surg 1993; 8(4): 277-85. 7. araújo tm, wilhelm rs, almeida ma. skeletal and dental arch asymmetries in individuals with normal dental occlusion. int j adult orthod orthog surg 1994; 9(2):111-8. 8. beyer jw, lindauer sj. evaluation of dental midline position. semin orthod 1998; 4(3):146-52. 9. slaj m, jezina am, lauc t, rajiæ-mestroviæ s, miksiæ m. longitudinal dental arch changes in the mixed dentition. angle orthod 2003; 73: 509-14. 10. maurice tj, kula k. dental arch asymmetry in the mixed dentition. angle orthod 1998; 68(1): 37-44. 11. hunter ws. lateral asymmetries of 93 maxillary arches. acta odont scand 1953; 11: 95-9. 12. hechter fj. symmetry, form and dimension of the dental arches of orthodontically treated patients. master’s thesis winnipeg: university of manitob, 1975. 13. morris jc, khanz. accuracy of stone casts produced by perforated trays and non-perforated trays. j prosth dent 1985; 53: 347. 14. al-zubair nm. dental arch asymmetry. e j dent 2014; 8(2): 224-8. 15. cohen jt. growth and development of the dental arches in children. jada 1940; 27:1250-60. 16. mcdougall pd, mcnamara ja jr, dierks jm. arch width development in class ii patients treated with the fränkel appliance. am j orthod 1982; 82:10-22. 17. moorrees cf. growth changes of the dental arches: a longitudinal study. j can dent assoc 1958; 24: 44957. 18. sillman jh. dimensional changes of the dental arches: longitudinal study from birth to 25 years. am j orthod 1964; 50: 824-42. 19. knott vb. longitudinal study of dental arch widths at four stages of dentition. angle orthod 1972; 42: 38794. 20. al-dulayme da. measurements of space loss followed prematurely extracted primary molars in a sample of iraqi children aged (8-9) years from baghdad city. a master thesis, college of dentistry, university of baghdad, 2002. 21. sawiris mm. the role of arthropometric measurements in the design of complete dentures. j dent 1977; 5: 141-8. 22. scott jh. the shape of the dental arches. j dent res 1957; 36: 996-1003. 23. bishara se, jakobsen jr, treder je, stasi mj. changes in the maxillary and mandibular tooth sizearch length relationship from early adolescence to early adulthood. a longitudinal study. am j orthod dentofac orthop 1989; 95: 46-59. 24. moorrees cf, gron am, lebret lm, yen pk, fröhlich fj. growth studies of the dentition: a review. am j orthod 1969; 55:600-16. 25. al-sarraf ha. maxillary and mandibular dental arch dimensions in children aged 12-15 years with class i normal occlusion. "cross-sectional study". master thesis, college of dentistry, mosul university, 1996. j bagh college dentistry vol. 26(2), june 2014 assessment of dental orthodontics, pedodontics and preventive dentistry 143 26. mohammad is. maxillary arch dimensions: a cross sectional study between 9-17 years. master thesis, college of dentistry, university of baghdad, 1993. 27. fabiane l, paulo r, arula n, guilmore j. dental arch dimensions in the mixed dentition: a study of brazilian children from 9 to 12 years of age. j appl oral sci 2011; 19(2):169-74. 28. ismail am, ghaib nh, hatem s. maxillary arch dimensions in iraqi population sample. iraqi dent j 1996; 8:111-20. 29. younes sa. maxillary arch dimensions in saudi and egyptian population sample. am j orthod 1984; 85: 83-8. 30. broadbent bh. ontogenic development of occlusion. angle orthod 1941; 11(4): 223-41. 31. daood zh. chronology of permanent teeth of iraqi children/baghdad city (a cross sectional study). a master thesis, university of baghdad, 2001. diyar final.doc j bagh college dentistry vol. 26(3), september 2014 micro ct analysis restorative dentistry 9 micro ct analysis of amount of dentin removal created by saf vs. protaper systems diyar k. bakir, b.d.s., m.sc. (1) hussain f. al-huwaizi b.d.s., m.sc., ph.d. (2) raid f. salman, b.d.s., m.sc., ph.d. (3) abstract background: dentin removed during root canal system instrumentation for creating adequate geometry for the canal and cleaning the canal. a new instrument had been marketed with the aim of optimum shaping of all parts of the canal system, however, no information present about the amount of dentin removal compared to conventional rotary system. this study investigated the amount of dentin removal when the canal instrumented by saf compared with protaper by using high resolution computed tomography (micro ct). materials and methods: twenty extracted single canalled teeth were utilized for this study; and randomly divided into 2 groups. in the first group, the root canals were prepared by using protaper rotary system till f2 and the root canal irrigated with 1ml of normal saline after each instrument. the root canals in the second group were prepared using saf for 2min, with continuous irrigation (normal saline). after rescanning, the amount of dentin removal was calculated. result: it was clear that the use of saf system had increase the amount of dentin removal and in quantity larger than that did by protaper system & the mean of net difference was (0.288mm ± 0.051). by using t-independent test, there was highly significant difference between the two groups at (p=0.001), with in favor of the saf system over protaper system at p< 0.01; in dentin removal quantity conclusion: root canal preparation with saf-system resulted in more and effectively removed dentin when compared with protaper rotary files. keywords: root canal preparation, saf-system, protaper rotary files, micro ct, amount of dentin removal. (j bagh coll dentistry 2014; 26(3):9-12). introduction the purpose of root canal preparation is to shape the canals to an adequate geometry and clean the canal system by promoting access for disinfection solutions. this strategy has been termed chemico-mechanical canal preparation. the mechanical canal preparation supports disinfection first via disturbing biofilms that adhere to canal surface and second by removing a layer of infected dentin (1). the important point in root canal preparation include preparation should be done without shaping errors such as transportation, elbow, zipping or perforation with more surface area prepared (2,3). the micro computed tomography is a high resolution scanning image with several promising applications in different fields of dentistry. in a recent methodological study, the possibility to quantitative assess amount of dentin removal in teeth was presented. a new developed self-adjusting file (saf) was designed to address the shortcomings of traditional rotary file by adjusting itself to the canal cross section. this instrument consists of a compressible hallow nickel-titanium tube or pla (1)assistant lecturer. college of dentistryhawler medical university. (2)professor. department of conservative dentistry, college of dentistry, university of baghdad. (3)assistant professor. college of dentistryhawler medical university. cement into a root canal, will exert pressure against the canal wall and adjust itself three dimensionally. the saf system used in an in and out motion powered by a handpiece and under a constant irrigation. the aim of this study is determining the amount of dentin removal when saf applied to root canals of anterior teeth compared to protaper system. materials and methods selection of teeth twenty extracted anterior teeth for the reasons unrelated to the current study were collected and stored in 0.1% thymol solution. then all the teeth were scanned by micro ct unit at an isotropic resolution of 35 µm (sc. medical/ switzerland). they were then accessed by using high –speed diamond burs, and patency of coronal canal was confirmed. then coronal flaring was accomplished with #2 gates glidding burs (dentsplymaillerfer, switzerland). then canal length was determined with size 15 k files (12mm), specimens were then randomly allocated to two groups with n= 10 each. root canal instrumentation • saf: group -1 ten samples were prepared by using saf operated in a transline (in and out) vibrating handpiece (gentle pomd, leavo. germany) j bagh college dentistry vol. 26(3), september 2014 micro ct analysis restorative dentistry 10 combined with a rdt3 head (redent nova) at a frequency of 83.3 h2 (5000 movements per minutes). the 2 mm diameter saf was inserted into the canal while vibrating and delicately advanced apically with an intermittent in and out hand movements of 5mm amplitude until it reach the predetermined working length. it was operated with continuous irrigation 2ml/min. the preparation continued for 4 minutes, and then the teeth were kept in container during transport. • protaper: group -2 for ten samples; the instrumentation was started with protper rotary file system according to the manufacturer instructions. the instruments were driven at 300 rpm with 2 n.cm of torque. after positioning of rubber stopper for all files, the sequence for preparation was, s1 file which was used for 1 minute 2mm shorter than the working length in a brushing motion for coronal one third with using a light coating glyde file prep that was applied to the file as a lubricant. then s2 file which was used for 1 minute 2mm shorter than the working length in a brushing motion for coronal two thirds with using a light coating glyde file prep as a lubricant. finally f2 file was used for full working length for 1 second using a light coating glyde file prep as a lubricant. irrigation with 1ml normal saline was used after each instrument and 1ml after completing the instrumentation with disposable syringe and an open-end 27 gauge needle. after each instrument the needle was inserted until it reached the predetermined working length and retracted 2mm before irrigation was applied. total instrumentation time was measured with timer that was equal to 2 minutes and the total irrigation volume was 4ml. after canal instrumentation the specimens directly send for post operative microct scans. microct measurements the tooth samples were measured before and after preparation with a commercially available cabinet cone-beam microct, (μct 35, scanco medical ag, brüttisellen, switzerland). it operates with a cone beam originating from a 7 μm focal-spot x-ray tube. the x-rays are detected by a digital cooled charged coupled device (ccd) camera based area detector and the projection data are computer-reconstructed into a 1024 x 1024 image matrix. the chosen voxel size was 20 μm in all three spatial dimensions. for each sample, 600 to 750 slices were scanned, covering a total of 12.00 mm to 15.00 mm, x-ray voltage was 70 kvp, intensity 114 μa, integration time 1600 ms. evaluation the mounting device ensured almost exact repositioning of the samples for both pre and post scanning procedure. superimposition was calculated subsequently with the software package ipl v5.15 (scanco medical ag). the two three dimensional scans were co registered with each other by three dimensional rotation and translation determined by maximizing the crosscorrelation of the two overlaid three –dimensional datasets of the outer hull of the tooth, which is unchanged by the root canal treatment. then by varying the relative translation in all three directions, we automatically detected the best superimposition of the outer root contour, with a precision better than one voxel. the matched root canals were then evaluated as follows: maximum diameters of the canals were determined by means of a distance transformation technique related to canal length. in their technique, the volumes of interest were filled with spheres sized to accommodate the maximum diameter within the structure. each voxel was assigned a local (thickness) value, which represented the diameter of the largest sphere in which that specific voxel was located. then pre and post thickness diameter was evaluated and the change between the pre and post thickness considered an amount of dentin removal in (mm). results protaper system the descriptive statistics for the mean values & the standard deviations of the quantitative dentin removal (qdr) in mm (pre-preparation versus post-preparation) for the protaper system used for preparation of the root canal samples had been shown in the table (1) (fig. 1). from the table (1), it was clear that the use of protaper system had increase the amount of dentin removal & the mean of net difference was (0.213mm ± 0.034). table 1: the descriptive statistics of the qdr in mm for protaper system used for preparation of the root canal samples protaper n min. max. mean s.e. s.d. variance pre10 0.546 1.294 0.802 0.061 ±.193 0.037 post10 0.703 1.533 1.014 0.068 ±.215 0.046 j bagh college dentistry vol. 26(3), september 2014 micro ct analysis restorative dentistry 11 saf system the descriptive statistics for the mean values & the standard deviations of the qdr in mm (prepreparation versus post-preparation) for the saf system used for preparation of the root canal samples had been shown in the table (2) (fig.1). from the table (2), it was clear that the use of saf system had increase the amount of dentin removal and in quantity larger than that did by protaper system & the mean of net difference was (0.288mm ± 0.051). by using t-independent test, there was highly significant difference between the two groups at (p=0.001) (table 3), with in favor of the saf system over protaper system at p< 0.01; in dentin removal quantity, (fig1) table 2: the descriptive statistics of the qdr in mm for saf system used for preparation of the root canal samples saf n min. max. mean s.e. s.d. variance pre10 0.479 0.965 0.681 0.046 ±.146 0.021 post10 0.838 1.265 0.969 0.042 ±.131 0.017 table 3: t-test for the difference between the two instruments used for preparation of the root canal samples in qdr figure 1: bar chart representing difference between the two instruments for qdr (mean net difference) discussion during root canal preparation, the most time consuming and demanding phase of endodontic therapy, the operators skills and the pathological conditions, which depend on dental anatomy and set limitations to the treatment, should be carefully evaluated. it is important that operators have thorough knowledge of dental anatomy and instrumentation techniques, know how to adapt the available instruments and materials to each case and develop satisfactory tactile sensation to control dentin removal by the action of endodontic files. all these factors are closely related with the root structure in different situations (4,5). it is generally accepted that the amount of remaining dentine is directly related to the strength of the tooth (6,7). lateral forces result in high stress concentrations in radicular dentine at the coronal one third of the root (8,9). the rotational axis of the tooth is located at the crest of the alveolar bone, and most of the applied force is concentrated around the circumference of the tooth where the crown diameter is the smallest, corresponding to the cervical region of the tooth at the cementoenamel junction (cej) (8,9), whereas the concentration of the forces is the lowest within the root canal (10). the centre of the root canal, representing the central axis of the tooth, is a neutral area with regard to force concentration instruments mean s.d. s.e. 95% confidence interval of the difference t-test d.f. p-value lower upper saf protaper -0.075 .0437 0.02 -0.116 -0.034 -3.831 18 .001 j bagh college dentistry vol. 26(3), september 2014 micro ct analysis restorative dentistry 12 (8,9). this force distribution may explain the susceptibility of teeth to fracture at the cej area when lateral forces are exerted on the coronal portion of the tooth during occlusal loading (8-10). from the point of view of stress concentration, the thickness of the dentinal wall between the root canal and its external circumference assumes great significance. there is a direct correlation between the root thickness and the ability of the tooth to resist lateral forces and avoid fracture (10,11). the thickness of the dentine wall is directly proportional to the ability of the tooth to withstand lateral forces. therefore, treatment that causes indiscriminate removal of tooth structure from the canal walls during endodontic treatment should be avoided (10). the present study evaluated two active niti systems. the design of this study was such that an analysis of areas before and after the root canal preparation to determine the increasing of area by mm, mean by increasing the area the more surface touched and more dentin removed. by this method there is significant difference between the two systems. this result might be explained by the single saf file is intended to be used throughout the procedure, starting as a compressed file that gradually enlarges in size during dentine removal with close, three dimensional adaptations to the canal walls with continuous irrigation (12). such mechanical preparation can be attributed to the 3-d stress building up in the lattice skeleton of the file when working compressed while removing dentine. furthermore, with the vibrating motion of the file, dentin was gradually and uniformly removed resulting in smooth surface that looks as if it were sandblasted. the surface of the saf is delicately rough with 3 μm peak-tobottom dimensions. this rough surface is present on every thin element of the niti lattice. the compression of the file generates circumferential pressure on the canal walls. the pressure is greatest when the file is inserted into the root canal and declines with the gradual enlargement of the canal. this change in pressure in turn affects the amount of dentin removed, increased it (12,13). references 1. metzger z, teperovich e, zary r, cohen r, hof r. respecting the root canal: a new concept of a selfadjusting file (saf). j endod 2010; 36: 679-90. 2. peters oa, paqué f. root canal preparation of maxillary molars with the self-adjusting file: a microcomputed tomographic study. j endod 2011; 37: 53-7. 3. peters oa, peters c. cleaning and shaping of the root canal system. in: cohen s, hargreaves km, eds. pathways of the pulp. 9th ed. st. louis: cv mosby; 2006. pp. 290-357. 4. wagner mh, barletta fb, reis ms, mello ll, ferreira r, fernandes al. nsk reciprocating handpiece: in vitro comparative analysis of dentinal removal during root canal preparation by different operators. braz dent j 2006; 17: 10-4. 5. plotino g, grande nm, falanga a, di giuseppe il, lamorgese v, somma f. dentine removal in the coronal portion of root canals following two preparation techniques. inter j endod 2007; 40: 85258. 6. lertchirakarn v, timyam a, messer hh. effects of root canal sealers on vertical root fracture resistance of endodontically treated teeth. j endod 2002; 28: 217–9. 7. wu mk, van der sluis lw, wesselink pr. comparison of mandibular premolars and canines with respect to their resistance to vertical root fracture. j dent 2004; 32: 265–8. 8. guzy ge, nicholls j. in vitro comparison of intact endodontically treated teeth with and without endopost reinforcement. j prosthet dent 1979; 42: 39–42. 9. assif, d, oren e, marshak bl, aviv i. photoelastic analysis of stress transfer by endodontically treated teeth to the supporting structure using different restorative techniques. j prosthet dent 1989; 61: 535– 43. 10. assif d, gorfil c. biomechanical considerations in restoring endodontically treated teeth. j prosthet dent 1994; 71: 565–7. 11. rosen h, partida-rivera m. iatrogenic fracture of roots reinforced with cervical collar. oper dent 1986; 11: 46–50. 12. metzger z. from files to saf: 3d endodontic treatment is possible at last. alpha omegan 2011; 104: 18-26. 13. hof r, perevalov v, zary r, metzger z. the selfadjusting file. part 2: mechanical analysis. j endod 2010; 36: 691–6. j bagh college dentistry vol. 28(4), december 2016 comparison of expression oral diagnosis 61 comparison of immunohistochemical expression of dnmt3b among oral, laryngeal and skin scc khaled j. abed, b.d.s., m.sc. (a) wasan h. younis, b.d.s., m.sc., ph.d. (b) abstract background: recently epigenetic alterations have received increased attention because of theirimportant role in the process of tumerigenesis. it has been found that more than half of genetic changes were epigenetic. epigenetic alterations are catalyzed by dnmts enzymes. increased knowledge about this molecular event may achieve progress in the war against cancer. the aim of this study was to evaluate and compare the expression of dnmt3b among oral, laryngeal and skin scc. materials and methods: this study was performed on (120) formalin-fixed, paraffin-embedded blocks, histopathologically diagnosed as oral, laryngeal and skin scc). immunohistochemical staining of dnmt3b antibody was performed on each case of this study. results: the immunohistochemical analysis showed that the dnmt3b is over expressed in oral, laryngeal and skin squamous cell carcinoma as (77.5%), (77.5%) and (72.5%) respectively, withsignificant difference in expression among them (p=0.009), the expression in all the three types is correlated positively with the degree of differentiation (p<0.001), (p<0.001) and (p=0.015) respectively. conclusion: according to the results of this study, epigenetic alterations are believed to play a crucial role inthe development of oral, laryngeal and skin scc.the results also, conclude that dnmt3b may act as a promising prognostic marker in cancer of epithelial in origin. keywords: oral, laryngeal, skin, expression, immunohistochemistry. (j bagh coll dentistry 2016; 28(4):61-67) introduction epigenetics is the study of heritable alterations in activity of gene or its function that is not related to any alteration in dna sequence itself (1). dna methylation is the most characteristic epigenetic mechanism which inherited without dna sequences changes (2). methylation of dna involving the transfer of methyl groups to the region 5 of cytosine residues that is located in the cytosine-guanine dinucleotides (cpg) via reactions catalyzed by protein called dna methyltransferase (dnmts). any abnormal methylation may cause the development of many diseases, especially by direct action on process of tumerigenesis or silencing of tumor suppressor genes that contain cpg islands in promoter region (3). dna methylation in cancer has become the matter of intense study, compared to normal cells; the cancer cells show major disruptions in pattern of dna methylation (4).inappropriate silencing of gene resulting from abnormal dna methylation largely contributes to malignant transformation, tumorigenesis, and progression of tumor (5). (a)ph.d. student. department of oral diagnosis, college of dentistry, university of baghdad. (b) professor. department of oral diagnosis, college of dentistry, university of baghdad. dnmt3b enzyme is one of the three well known dna methyltransferases with catalytic activity. it may play an important oncogenic role during the process of carcinogenesis, and its genetic variants had been recognized to be correlated with risk of various cancers (6). it had been found that dnmt3b is over-expressed in many cancerous tissues (7), and its expression was found to be important for malignant cell survival (8). dnmt3b has been reported to either contribute to dna methylation or maintenance of aberrant patterns of dna methylation in cancer (9). this study was performed to find out the differences in expression of dnmt3b among oral, laryngeal and skin squamous cell carcinoma, and to identify the correlation with the histological grade. materials and methods a total of one-hundred and twenty cases of formalin-fixed, paraffin embedded tissue blocksthat histopathologically identified as oral, laryngeal andcutaneous squamous cell carcinoma (forty blocks for each type) were included in the study. oral squamous cell carcinoma blocks were selected from the archives of oral pathology department, college of dentistry, university of baghdad, while the laryngeal and cutaneous squamous cell carcinoma cases were obtained from histopathology laboratory of ghazi al hariry hospital of specialized surgeries for the period from october 2014 till june 2015. immunohistochemical analysis was performed on the samples to study the expression of j bagh college dentistry vol. 28(4), december 2016 comparison of expression oral diagnosis 62 dnmt3b in tissue blocks. five u thick tissue sections of the blocks were mounted on positively charged slides, dewaxed and rehydrated in xylene and serial dilutions of ethanol. endogenous peroxidase activity and non-specific antibody binding were blocked with h2o2 and protein block respectively. after blocking, the antigens were retrieved in a hot solution (100x citrate buffer ph 6.0) for 10 minutes.the sections were incubated with dnmt3b rabbit polyclonal antibody ab71747 diluted into (1∶50) for 6 hours. subsequently, biotin free-hrp linked secondary antibodies were applied. followed by application of diluted dab (chromogenic solution) onto sections and counterstained with hematoxylin. immunoreactivity was semi-quantitatively evaluated for positively stained cells as nuclear and/or cytoplasmic immunoreactivity in five representative microscopic fields, then calculating the percentage of positive cells. the expression of dnmt3b in tissue sections was evaluated as 0 when no positive stained cells observed, score 1 (weak) for 11%50%, of positive tumor cells, score 2 for 51%-80% and score 3(strong) for more than 80% (81%-100%) positively stained tumor cells according to chen et al (10). statistical analysis was performed using the spss version 21 computer software in association with microsoft excel. the statistical significance of variations in median was tested via kruskal wallis test, and assessed by spearman rank linear correlation coefficient. results table1 shows that most cases of oral, laryngeal and skin squamous cell carcinoma were ranged from 50-69 years with (50%) for oscc, (80.0%) for lscc and (47%) for skin scc. also, this table showed that most of patients were males in oral, laryngeal and skin scc, (52.5%), (72.5%) and (67.5%) respectively. table 2 shows that the most frequent degree of differentiation in oscc is well differentiated 18 cases (45.0%), followed by moderately differentiated 15 cases (37.5%). whereas in lscc the predominant grade is moderately differentiated 17 cases (42.5%), followed by well differentiated 12 (30.0%). in skin the well differentiated degree is so high 24 cases (60.0%) compared to moderately differentiated 11 (27.5%) and poorly differentiated 5 cases (12.5%). table 3 shows that ninety one cases (75.8%) showed dnmt3b positive expression among the three types, whereas 29 cases (24.16%) were negative. as shown in table 3 in oscc 31cases (77.5%) were positive. the commonest category of dnmt3b expression in oscc was score1 (18 cases) (45%), followed by score 2 (8 cases) (20%). similarly, in lscc (77.5%) were positive (31 cases). the commonest category was score 2 (15cases) (37.5%), followed by score 3 (12 cases) (30%).in skin scc the positive cases were (29) (72.5%). as shown in table 3, mann-whitney statistical test revealed that the median dnmt3b score in oral scc (score-1) was significantly lower than that in laryngeal scc(p= 0.024), while it was almost comparable to that of skin scc(p= 0.59), but a significant difference was recorded between skin and laryngeal scc (p=0.003). as shown in table 4, the median dnmt3b score was significantly lower among those with well differentiated tumor (score 1) and increased with increasing tumor grade to reach its highest median score (score 3) among those with poorly differentiated tumor. this marker showed a statistically significant moderately strong positive linear correlation with tumor grade among oral scc cases (r=0.568, p<0.001). as shown in table 5, the median dnmt3b score was significantly lower among those with well differentiated tumor (score 1) and increase with increasing tumor grade to reach its highest median score (score 3) among those with poorly differentiated tumor. this marker showed a statistically significant strong positive linear correlation with tumor grade among laryngeal scc cases (r=0.668). as shown in table 6, the median dnmt3b score was obviously lower among those with well differentiated tumor (score 1) and increased with increasing tumor grade to reach its highest median score (score 2) among those with poorly differentiated tumor. the observed differences, however failed to reach the level of statistical significance. this marker showed a statistically significant weak to moderately strong positive linear correlation with tumor grade among skin scc cases (r=0.383). in this study the pattern of expression was nuclear and/or cytoplasmic. with more cytoplasmic expression .only few exclusive cytoplasmic and no exclusive nuclear expression was observed as shown in figures (1, 2 ,3). j bagh college dentistry vol. 28(4), december 2016 comparison of expression oral diagnosis 63 table 1: frequency distribution of the study groups by age and gender study group oral scc laryngeal scc skin scc n % n % n % age group (years) <50 11 27.5 3 7.5 13 32.5 50-69 20 50.0 32 80.0 19 47.5 70+ 9 22.5 5 12.5 8 20.0 total 40 100.0 40 100.0 40 100.0 gender female 19 47.5 11 27.5 13 32.5 male 21 52.5 29 72.5 27 67.5 total 40 100.0 40 100.0 40 100.0 table 2: frequency distribution of the 3 study groups by tumor grade study group oral scc laryngeal scc skin scc n % n % n % tumor grade well differentiated 18 45.0 12 30.0 24 60.0 moderately differentiated 15 37.5 17 42.5 11 27.5 poorly differentiated 7 17.5 11 27.5 5 12.5 total 40 100 40 100 40 100 table 3: the difference in median score category of dnmt3b between the 3 study groups. study group oral scc laryngeal scc skin scc n % n % n % p dnmt3b score 0.009 negative (< 10%) 9 22.5 9 22.5 11 27.5 score-1 (11-50%) 18 45.0 4 10.0 16 40.0 score-2 (51-79%) 8 20.0 15 37.5 12 30.0 score-3 (80%+) 5 12.5 12 30.0 1 2.5 total 40 100.0 40 100.0 40 100.0 median score-1 (11-50%) score-2 (51-79%) score-1 (11-50%) mean rank 56.1 73.6 51.8 p (mann-whitney) for difference between: laryngeal scc x oral scc = 0.024 skin scc x oral scc = 0.59[ns] skin scc x laryngeal scc = 0.003 j bagh college dentistry vol. 28(4), december 2016 comparison of expression oral diagnosis 64 table 4: the difference in median score category of dnmt3b among the three tumor grades among cases with oral scc. tumor grade well differentiated moderately differentiated poorly differentiated oral scc n % n % n % p dnmt3b score <0.001 negative (< 10%) 6 33.3 3 20.0 0 0.0 score-1 (11-50%) 10 55.6 8 53.3 0 0.0 score-2 (51-79%) 2 11.1 3 20.0 3 42.9 score-3 (80%+) 0 0.0 1 6.7 4 57.1 total 18 100.0 15 100.0 7 100.0 median score-1 (11-50%) score-1 (11-50%) score-3 (80%+) mean rank 15.4 19.7 35.2 r=0.568 p<0.001 table 5: the difference in median score category ofdnmt3b among the 3 tumor grades among cases with laryngeal scc. tumor grade well differentiated moderately differentiated poorly differentiated laryngeal scc n % n % n % p dnmt3b score <0.001 negative (< 10%) 5 41.7 3 17.6 1 9.1 score-1 (11-50%) 4 33.3 0 0.0 0 0.0 score-2 (51-79%) 3 25.0 11 64.7 1 9.1 score-3 (80%+) 0 0.0 3 17.6 9 81.8 total 12 100.0 17 100.0 11 100.0 median score-1 (11-50%) score-2 (51-79%) score-3 (80%+) mean rank 11.2 20.6 30.6 r=0.668 p<0.001 table 6: the difference in median score category of dnmt3b among the 3 tumor grades among cases with skin scc. tumor grade well differentiated moderately differentiated poorly differentiated skin scc n % n % n % p dnmt3b score 0.05[ns] negative (< 10%) 8 33.3 3 27.3 0 0.0 score-1 (11-50%) 12 50.0 2 18.2 2 40.0 score-2 (51-79%) 4 16.7 6 54.5 2 40.0 score-3 (80%+) 0 0.0 0 0.0 1 20.0 total 24 100.0 11 100.0 5 100.0 median score-1 (11-50%) score-2 (51-79%) score-2 (51-79%) mean rank 17.3 23.5 29.2 r=0.383 p=0.015 j bagh college dentistry vol. 28(4), december 2016 comparison of expression oral diagnosis 65 discussion in the current study, of 120 oral scc, lscc and skin scc cases assayed for dnmt3b revealed high percentage expression of dnmt3b among oral, laryngeal and skin squamous cell carcinoma 91 (75.8%) and 29 (24.2%) were negatively stained. ineach of oscc and lscc 31(77.5%) of the cases were positively immunoreacted to dnmt3b.dnmt3b immunoreactivity demonstrated no correlation with age/gender. while it exhibited strong association with tumor differentiation (p<0.001). this may be due to the fact that loss of p16 which is frequently inactivated in hnscc by dna hypermethylation is correlated with poorly differentiated hnscc (11). also, tgf-β1 that enhances dnmts expression is overexpressed in poorly differentiated scc compared to well differentiated ones (12). although many previous studies have reported alteration in methylation pattern of malignant cells compared to non malignant, there is limits in understanding the exact mechanism (13). however, many studies illustrated the role of dnmt3b in initiation of cancer by inactivation of several tumor suppressor genes which lead to progression of hnscc cancer (14). among the most important genes that inactivated by dnmt3b via hypermethylation and associated with poor prognosis in oral and laryngeal scc is p16 and death associated protein-kinase (dapk) (15). p16 is cyclin-dependent kinase inhibitor that regulates the rb pathway, which inhibits progression of cell cycle (16). dapk that associated with apoptosis also is hypermethylated in oral and laryngeal scc (17).over expression of tgf-β1been found in most of head and neck scc (18) .tgf-β1 upregulates the expression of il6 (19). also, tgf-β1 is considered a master regulator of dna methylation via an increase expression of dnmts in cancers (20). il 6 which is a cytokine with multifunction (21) and secreted by many cancerous cells (22) plays an important role in determining the biological behavior of oral squamous cell carcinoma (23) and laryngeal squamous cell carcinoma (24). il-6 induced hypermethylation by mediating over expression of dnmt3b which may contribute to an aggressive behavior (25). also, il-6 cause activation of janus kinase (jak) following binding to its receptor which mediate phosphorylation of signal transducer and then activation of the transcription factor signal transducer and activator of transcription (stat). the activated stat translocated to nucleus to activate targets like vascular endothelial growth factor (vegf) that increase the invasion of tumor (19). activated stat controls proliferation, invasion, migration of cells and angiogenesis (26). dna methylation may enhance progression of cancer (27). it has been found that activated il 6 might promote tumerogensis via altering methylation of dna by increase expression of dnmt3b and decrease ecadherin (28) increase vegf and mmp9, so the mechanism by which dnmt3b mediate an aggressive behavior in oral and laryngeal were epithelial mesenchymal transition (emt) promotion and angiogensis (10). so over expression of dnmt3b and activated tgf-β1/il-6 pathways may be responsible for the aggressive behavior of oral and laryngeal squamous cell carciniomas.with regard to skin scc our data showed high percentage of dnmt3b expression (72.5%). this high percentage of dnmt3b expression goes withthe results of nandakumar et al. (29) who had observed higher level of dnmt3b in skin scc compared to normal skin. the statistical results showed a positive correlation tohistological grade (p=0.015). this is due to fact that dna methylation in poorly or moderately differentiated tumors is more frequent than in the well differentiated ones (30). figure 1: nuclear and cytoplasmic expression of dnmt3b in oscc (x40) figure 2: nuclear and cytoplasmic expression of dnmt3b in lscc (x40) figure 3: nuclear and cytoplasmic expression of dnmt3b in skin scc (x40) j bagh college dentistry vol. 28(4), december 2016 comparison of expression oral diagnosis 66 the molecular mechanism for role of dna methylation in skin scc pathogenesis may be due to that activity of dnmts in uvbexposed epidermis is significantly higher than that in non uvb exposed epidermis (29). less role of p16 hypermethylation established in skin scc (31). compared to silencing of p53 tumor suppressor gene by dna hypermethylation that caused by uv radiation (32), in this study the pattern of expression was nuclear and/or cytoplasmic. with more cytoplasmic expression. only few exclusive cytoplasmic and no exclusive nuclear expression was observed. cytoplasmic imunoreactivity of this biomarker counted, because it has been found that over-expression of dna methyltransferases switch toaccumulating dna hypermethylation (10). where over expression of this enzyme in cytoplasm give us a concept that it would translocate to nucleus soon or later and cause dna methylation. it has been found that intracellular localization of dnmt3b enzyme is dynamic during cell cycle, where it is diffusely distributed between nucleus and cytoplasm throughout most g1phase of cell cycle, during s phase in which dna replication enhanced, localization correlate with subnuclear sites. while through g2 and m phases there were preferences of binding with pericentric heterochromatin (33). in conclusion: although the expression of dnmt3b was high among the three types , but data showed that epigenetic alterations in oscc and lscc were more than that in skin scc and this may be attributed to more silencing of tumor suppressor genes in hnscc as a result of multiple etiological factors compared to that occurred in skin scc. and it's positive correlation with histopathological grades in the three types indicating that this biomarker could be used as prognostic marker in cancer of epithelial origin. references 1. moore ld, le t, fan g. dna methylation and its basic function. neuropsychopharmacol reviews 2013; 38: 23–38. 2. nandakumar v, vaid m, tollefsbol to, katiyar sk. aberrant dna hypermethylation patterns lead to transcriptional silencing of tumor suppressor genes in uvb-exposed skin and uvb-induced skin tumors of mice. carcinogenesis 2011; 32:597–604. 3. alessio ac, szyf m. epigenetic tete-a-tete: the bilateral relationship between chromatin modifications and dna methylation. biochem cell biol 2006; 84: 463-76. 4. deckers iag, schouten lj, neste lv, van vlodrop ijh, soetekouw pmmb, et al. promoter methylation of cdo identifies clear-cell renal cell cancer patients with poor survival outcome. clin cancer res 2015; 21: 3492-500. 5. laird pw. cancer epigenetics. hum mol genet 2005; 14(1): 65-76. 6. liu z, wang l, wang le et al. polymorphisms of the dnmt3b gene and risk of squamous cell carcinoma of the head and neck: a case–control study. cancer letters 2008; 268:158–65. 7. wongtrakoongate p, li j, andrews pw. azadeoxycytidine induces apoptosis or differentiation via dnmt3b and targets embryonal carcinoma cells but not their differentiated derivatives. br j cancer 2014; 110(8): 2131–8. 8. gordon ca, hartono sr, chédin f inactive dnmt3b splice variants modulate de novo dna methylation. plos one 2013; 8(7): e69486. 9. weisenberger dj, velicescu m, cheng jc, gonzales fa, liang g, jones pa. role of the dna methyltransferase variant dnmt3b3 in dna methylation. mol cancer res 2004; 2: 62–72. 10. chen w-c, chen m-f, lin p-y. significance of dnmt3b in oral cancer. plos one 2014; 9(3): e89956. 11. magić z, supic g, branković-magić m, jović n. dna methylation in the pathogenesis of head and neck cancer. intech. 2013. 12. zedan w, mourad mi, abd el-aziz sm, salamaa nm, shalaby aa. cytogenetic significance of chromosome 17 aberrations and p53 gene mutations as prognostic markers in oral squamous cell carcinoma. diagn pathol 2015; 10: 2. 13. shah sp, morin rd, khattra j, prentice l, pugh t, burleigh a, delaney a, gelmon k, guliany r, senz j, et al. mutational evolution in a lobular breast tumour profiled at single nucleotide resolution. nature 2009; 461: 809–13. 14. supic g, kozomara r, jovic n, zeljic k, magic z. prognostic significance of tumor-related genes hypermethylation detected in cancer-free surgical margins of oral squamous cell carcinomas. oral oncol 2011; 47(8): 702-8. 15. wong t, gao w, li z, chan jy, ho w. epigenetic dysregulation in laryngeal squamous cell carcinoma. j oncol 2012; article id 739461, 10 pages. 16. akin s, babacan t, sarici f, altundag k. a novel targeted therapy in breast cancer: cyclin dependent kinase inhibitors. jbuon 2014; 19(1): 42-6. 17. li c, wang l, su j, ruhui zhang, fu l, yanmin z. mrna. mrna expression and hypermethylation of tumor suppressor genes apoptosis protease activating factor-1 and death-associated protein kinase in oral squamous cell carcinoma. oncol lett 2013; 6(1): 2806. 18. white ra, malkoski sp, wang x-j. tgfβ signaling in head and neck squamous cell carcinoma.oncogene. 2010; 29(40): 5437–46. 19. chen mf, wang wh, lin py, lee kd, chen wc. significance of the tgf-beta1/il-6 axis in oral cancer. clin sci lond 2012; 122: 459–72. 20. matsumura n, huang z, mori s, et al. epigenetic suppression of the tgf-beta pathway revealed by transcriptome profiling in ovarian cancer. genome res 2011; 21: 74–82. 21. babon jj, varghese ln, nicola na. inhibition of il-6 family cytokines by socs3. semin immunol 2014; 26(1):13-9. j bagh college dentistry vol. 28(4), december 2016 comparison of expression oral diagnosis 67 22. mojtahedi z, khademi b, hashemi sb. serum interleukin-6 concentration but not interleukin-18, is associated with head and neck squamous cell carcinoma progression. pathol oncol res 2011; 17(1): 7–10. 23. singh u, shevra cr, singh s, singh n, kumar s, madhukar r. interleukin-6 and interleukin-4 levels in multiple myeloma and correlation of interleukin-6 with β2 microglobulin and serum creatinine. clin cancer invest j 2015; 4(2): 211-5. 24. nikakhlagh s, ranjbari n, khorami e, saki n. association between serum levels of interleukin-6 and stage of laryngeal cancer. iran j otorhinolaryngol 2015; 27(80): 199–205. 25. chen mf, chen pt, lu ms, lin py, chen wc. il-6 expression predicts treatment response and outcome in squamous cell carcinoma of the esophagus. mol cancer 2014; 12: 26. 26. kamran mz, patil p, rajiv p. gude. role of stat3 in cancer metastasis and translational advances. biomed research international.26 august 2013; article id 421821, 15 pages. 27. johnson kc, koestler dc, fleischer t, chen p, jenson eg, marotti jd, et al. dna methylation in ductal carcinoma in situ related with future development of invasive breast cancer. clinical epigenetics 2015, 7: 75. 28. hameed r, raimondi sl. the role of aberrant dnmt3bs in tumor progression a review. cancer cell & microenvironment 2015; 2: e847. 29. nandakumar v, vaid m, katiyar sk. (−)epigallocatechin-3-gallate reactivates silenced tumor suppressor genes by reducing dna methylation and increasing histones acetylation in human skin cancer cells. carcinogenesis 2011; 32: 537–44. 30. li b, wang b, niu l, jiang l, qiu c. hypermethylation of multiple tumor-related genes associated with dmnt3b upregulation served as a biomarker for early diagnosis of esophageal squamous cell carcinoma. epigenetics 2011; 6(3): 307–16. 31. arbiser jl, fan c, su wx, vanemburgh bo, et al. involvement of p53 and p16 tumor suppressor genes in recessive dystrophic epidermolysis bullosaassociated squamous cell carcinoma. j invest dermatol 2004; 123:788-90. 32. katiyar sk, singh t, prasad r, sun q, vaid m. epigenetic alterations in ultraviolet radiationinduced skin carcinogenesis: interaction of bioactive dietary components on epigenetic targets. photochem photobiol 2012; 88(5): 1066–74. 33. gacema rb, hachana m, ziadi s, et al. clinicopathologic significance of dna methyltransferase, 3a, and 3b overexpression in tunisian breast cancers. human pathol 2012; 43: 1731-8. areej final.doc j bagh college dentistry vol. 26(3), september 2014 sonographic evaluation oral diagnosis 49 sonographic evaluation of masseter muscle thickness in bruxist and non-bruxist subjects areej a. najm, b.d.s., m.sc. (1) abstract background: masseter muscle is a jaw closing muscle of the mandible involved in para functional habits; which include lip and cheek chewing, fingernail biting, and teeth clenching or bruxism which can be classified as awake or sleep bruxism. patients with sleep bruxism are three to four times more likely to experience jaw pain and limitation of movement than people who do not experience sleep bruxism. the aim of this study is to measure the thickness of the masseter muscle in bruxist subjects and compare it with non-bruxist subjects by using sonography. materials and method: forty iraqi subjects with age ranged (20-40) divided into two groups according to the presence of bruxism. clinical examination was made and masseter muscle thickness measured for both groups using sonography. results: for bruxist subjects the mean thickness of masseter muscle in relaxation and clenching were (11.7 ± 1.4 mm) and (16.4 ± 1.3 mm). for non bruxist subjects were (11.2 ± 0.4 mm) and (13 ±0.3 mm) respectively. there was an extremely high statistical significant difference in masseter muscle thickness under clenching between bruxist and non bruxist subjects ( it was higher in bruxist group). masseter muscle thickness under relaxation was significantly lower than that under clenching for both groups. also there was a positive correlation between masseter muscle thickness and muscle function in bruxism situation. conclusion: masseter muscle in bruxist subject was thicker when compared to non-bruxist subject. masseter muscle thickness was found to be positively correlated with increasing muscle function. the findings of this study indicate that the functional capacity of the masseter muscle affected by bruxism and may be considered as one of the factors influencing muscle thickness. key words: masseter muscle, sonography, bruxism. (j bagh coll dentistry 2014; 26(3):49-52). :الخالصة وصك او صریف األظافرقضم , العضالت المسؤولة عن غلق الفك السفلي والتي تستخدم في بعض العادات مثل مضغ الشفة والخد إحدىالعضلة الماضغة حي قارنتھ مع مجموعة سلیمة و قیاس سمك العضلة الماضغة لدى مرضى صك االسنان ومھدف الدراسة ھ. لیقظة و عند النوموالتي تصنف الى نوعین عند ا األسنان تم فحصھم وتقسیمھم الى مجموعتین تبعا ) سنھ 40-20(متبرع في الدراسة تراوحت اعمارھم بین أربعونشارك .وذلك باستخدام التصویر بالموجات فوق الصوتیة ظھرت النتائج ان سمك العضلة لدى مرضى صك ا. ن باستخدام الموجات فوق الصوتیةلوجود حالة صك االسنان ومن ثم تم قیاس سمك العضلة لدى المجموعتی على ) ملم3,0±13(و ) ملم4,0±2,11(للمجموعة السلیمة كانت القیاسات ). ملم 3,1±4,16(و ) ملم 4,1± 7,11(االسنان في حالتي استرخاء وانقباض العضلة كذلك سمك ) كان اكثر لدى مرضى صك االسنان(بین المجموعتین كانت ھناك فروقات احصائیة ذات داللھ عالیة جدا في سمك العضلة عند االنقباض. التوالي العضلة الماضغة لدى مرضى صك االسنان اسمك مقارنة مع : االستنتاج.العضلة عند االسترخاء كان اقل بكثیر من السمك تحت االنقباض ولدى المجوعتین الدائیة للعضلة الماضغة تتاثر بحالة صك االسنان وتعتبر من احدى العوامل التي تؤثر القدرة ا. سمك العضلة یتناسب طردیا مع زیادة وظیفتھا.االشخاص الطبیعین .على سمك العضالت introduction intensive use of any skeletal muscle may cause changes in the muscle fiber size and composition, which in turn will increase the strength of the muscle and the resistance to fatigue. this is also true for the masticatory muscles. prolonged high activity of these muscles resulted in increased thickness of the masseter muscle (1). masseter muscle is a bulky strong muscle found in the cheek region. it is rectangular in shape and in the frontal view it curves from the inferior boarder of the zygomatic arch to the inferior edge of the ramus (2). brunel et al. (3) also described the masseter muscle as being multipennate and possessing three layers (superficial, intermediate and deep) that are partially separated by tendinous septa and which overlap one another from the superior to deep and anterior to posterior.(3) (1)assistant lecturer. department of oral diagnosis. college of dentistry, university of baghdad. masseter muscle thickness may be measured using mri, ct, or us, but for clinical examination , sonography is better than mri and ct because it is a rapid, simple and inexpensive technique, the equipment can be easily handled and transported, and it has no known cumulative biological effects (4). the term bruxism is derived from the french word, "la bruxomanie", it has been defined as "a nonfunctional, voluntary or involuntary mandibular movement which may occur during the day or night, manifested by the occasional or habitual grinding, clenching or clicking of the teeth" (5). the abnormal force created by bruxism is destructive to teeth, periodontal tissue, temporomandibular joints, masticatory muscles and causes muscle fatigue (6). signs and symptoms of bruxism and parafunctional activity include hypertrophied masseter and temporalis muscles, myocitis of these same muscles, morning jaw stiffness, teeth sensitivity, shiny spot and fractured restoration (6,7). masseter, temporalis and pterygoideus medialis muscles are j bagh college dentistry vol. 26(3), september 2014 sonographic evaluation oral diagnosis 50 continually stimulated by bruxism. unilateral and/or bilateral hypertrophy of masseter are clinically discernable in the case of longstanding bruxism, while electromyographic studies show abnormally high tonus in all three muscles(8) . masseter muscle hypertrophy was first described be legg (9) in a 10 years old girl who concurrent idiopathic temporalis muscle hypertrophy. the most commonly quoted etiology in the literatures is grinding in teeth, or habitual clenching of the teeth. (10) a hypertrophied muscle will alter facial symmetry, generating discomfort and negative cosmetic impact in many patients, even though there are several authors claim that emotional stress leading to chronic forceful clenching of the jaws results in hypertrophy of the muscle. (11) the aim of the study was to measure the thickness of masseter muscle in individuals with bruxism and compare it with that of normal individuals using sonography. materials and methods forty adult male volunteers with age ranged (20-40 y) selected from patients attending alkudher general hospital ( almuthana city) for sonographic evaluation of different purposes for period extended from feb. to april 2014, the entire participants have normal range of body mass index according to who system (12), history had been taken from them and then clinical examination done, including analysis of coincident tooth wear, shiny spots on restorations, fractured restoration, sounds associated with bruxism, jaw muscles discomfort and masseter muscle hypertrophy upon digital palpation, then participants divided into two groups (20 bruxist and 20 non bruxist). they were seated in supine position then masseter muscle thickness was measured for each participant using ultrasound on a level halfway between the zygomatic arch and gonial angle, under both conditions (relaxation and clenching) (13), in relaxation the participants asked to maintain slight inter-occlusal contacts, while in clenching they asked to clench maximally in the inter-cuspal position. light pressure was applied to the muscle to avoid compression of the soft tissue and muscle, thus avoiding erroneous measurements. the measurements were made directly from the image at the time of scanning (as shown in figure 1). results descriptive statistics for masseter muscles thickness (mmt) under both conditions were listed in details in table 1. the means and sd of figure 1: masseter muscle thickness as measured on ultrasound in both relaxed and clenched states. masseter thickness in bruxsit subjects under relaxation and clenching were (11.7 ± 1.4 mm) and (16.4 ± 1.3 mm) respectively, while for non bruxist subjects (mmt) under relaxation and clenching were (11.2 ± 0.4 mm) and (13 ±0.3 mm) respectively. mmtrelaxed was significantly lower than mmtclenched (p< 0.0001) for both groups. it also shows that mmt –clenched for bruxist subjects was significantly higher than those for non-bruxsit subjects (p<0.05). but there was no statistical significant difference in mmtrelaxed between the two groups. comparison of masseter muscle thickness under both conditions between the two groups was made and listed in table 2. discussion recently, mmt has been considered as one indicator of jaw muscle function (14). masseter muscle is a superfacial muscle and can be easily recorded on sonography. it was easily identified as a homogenous structure lying adjacent to the echogenic band of the mandible. sonography of masseter muscle is reliable, reproducible, simple and rapid method (4). the results of the present study show variations in mmt in relaxation and clenching among subjects of both study groups, bruxist subjects had thicker masseter muscle compared to non-bruxist. muscle thickness has been considered as an indicator of muscle function and there were many studies concerned with measuring mmt in relation to dentofacial pattern, maxillofacial morphology, dental arch width, different splints thickness in bruxist individuals (4,6,15,16), or comparing the thickness during different stages of treatment such as treatment of cl ii relationship with twin block appliance or cross bite patients (13,17), but there j bagh college dentistry vol. 26(3), september 2014 sonographic evaluation oral diagnosis 51 was no study found comparing mmt between bruxist and nonbruxist subjects. subjects who participated in this study did not have extreme body mass index because masseter muscle thickness affected by body mass index (18). kubota et al. (14) conducted study on 80 adult male and investigated how the thickness of masseter muscle relates to maxillofacial morphology using us and cephaolmetric radiograph. the results of mmtrelaxation and clenching were (15.8±3 mm) and (16.7 ± 2.7) mm, respectively. this result was confirmed with the results of the current study. kiliaridis et al. (15) examined 60 patients with age ranged 7-18 y and reported mmt under relaxation and clenching for female (11.6 ±1.4mm) and (11.9 ±1.6 mm) respectively, while for male was (12.1 ±2.2 mm) and (12.4± 2.2 mm) respectively. these results were lower than the results of the current study and this due to fact that there was a positive correlation between muscle thickness and age, and the subjects of kiliaridis et al (15) were younger than those of the present study. satrigolu et al. (16) conducted a study on turkish population and reported (13.5 ±1.9 mm) and (14.5± 1.8 mm) for mmtrelaxed and clenched respectively. these variations in the thickness of the masseter across different populations may be associated with racial perspectives and the relative indulgence in masticators activities that may have lead to the attendant adaptive increase in size. it may also be associated with the orientation, type, size and composition of the muscle fibres. also age was described as a factor in the increase in muscle thickness and development. in addition, the genetic and physiological makeup and environmental inclinations of males encourage muscular development and the mastication muscles are not left out. kiliaridis et al. (17) measured mmt in examined children wearing twin-block appliance and concluded that muscle thickness was decreased when muscle activity was reduced , the results of the present study agreed with this conclusion (mmtrelaxation achieved after treatment was lower than mmtduring function). rohila et al. (4) examined 60 patients and reported mmt relaxation (12.5 ±1.2 mm) and mmtclenching (13.8± 1.3mm). egwe et al. (2) using ultrasonography for evaluation of mmt in an adult nigerian population with age ranged 1930 years and reported mmtrelaxation (13.4 ±3.1mm) and mmtclenching (17.03±3.5 mm). this result is confirmed with the result of the present study. many of the previously mentioned studies concluded that mmt was increased with increasing muscle function ,this was absolutely confirmed with the result of the current study and it was possibly due to involuntary low-level continuous contraction of the masticatory muscle associated with muscle pain and fatigue and subsequent hardness of the muscle because bruxism is a parafunctional habit and represent a continuous stimulation not only for masseter muscle but also for medial pterygoid and temporalis muscles and electromyograpgic studies show abnormally high tonus in all three muscles. as conclusion; the abnormal force created by bruxism is destructive to teeth, periodontal tissue, masticatory muscles, temporomandibular joints and causes muscle fatigue. the finding of the present study showed a significant positive correlation between masseter muscle thickness and bruxism, the muscle thickness increase as the muscle function increase. masseter muscle hypertrophy associated with limitation of mouth opening, tension, pain at region of involved muscle in addition to facial asymmetry that cause psychological problem to patient. the familiarity with this condition is important to settle the differential diagnosis with other pathologies such as parotid gland tumors and dental infection. misdiagnosed cases due to lack of familiarity with this entity may lead to unnecessary biopsies, explorative surgeries and even radiotherapy for suspected parotid tumors. table 1: descriptive statistics for the different states of mmt in millimeters (mm) for bruxist and non bruxist study groups. bruxist non bruxist mmt-relaxed mmtclenched mmt-relaxed mmtclenched n 20 20 20 20 mean 11.7 16.4 11.2 13 sd 1.4 1.3 0.4 0.3 se 0.3 0.3 0.09 0.08 low 95% conf. limit 11 14.6 11 12.8 up 95% conf. limit 12.4 15.9 11.4 13.1 range 10.1-14.7 13.3-19.5 10.4-11.8 12.4-13.5 j bagh college dentistry vol. 26(3), september 2014 sonographic evaluation oral diagnosis 52 table 2: comparison of the mmt-relaxed and mmt-clenched between the study groups study groups n tvalue d.f pvalue mmtr and mmtc for all study groups 40 9.02 78 <0.0001, hs mmtr and mmtc for bruxist group 20 8.1 38 0.0005, hs mmtr and mmtc for non bruxist group 20 3.6 38 0.02, s mmtr for bruxist and non bruxist groups 40 1.5 38 0.1, ns mmtc for bruxist and non bruxist groups 40 7.4 38 < 0.0001, hs figure 2: masseter muscle thickness in relaxation and clenching for study groups. references 1. kiliaridis s, mahboubi p, raadsheer m, katsaros c. ultrasonographic thickness of the masseter muscle in growing individuals with unilateral crossbite. angle orthod 2007; 77(4): 607-11. 2. egwu o, njoku c, ewunonu e, ukoha u, eteudo a, mgbachi c. assessment of masseter muscle thickness in an adult nigerian population: an ultrasound based study. international j biomedical res 2012; 3(3):1436. 3. brannel g, haddioni a, bravetti p, zouaoni a, gaudy jf. general organization of the human masseter aponeurosis: changes with age. surg and rad anat 2003; 25(4): 270-83. 4. rohila a, sharma v, shrivastav p, nagar a, singh g. an ultrasonographic evaluation of masseter muscle thickness in different dentofacial patterns. indian j dental res 2013; 23(6): 726-31. 5. gill p, chawla k, chawla s. bruxism/bruxomania, causes and management. indian j dental sci 2011; 1(3): 26-7. 6. abekura h, yokomura m, sadamiri sh, hamada t. the initial effects of occlusal splint vertical thickness on the nocturnal emg activities of masticatory muscles in subjects with a bruxism habit. international j prosthodontics 2008; 21(2): 116-20 7. calderon p, kogawa e, lauris j, conti p. the influence of gender and bruxism on the human maximum bite force. j appl oral sci 2006; 14(6): 448-53. 8. basie v, mehulie k. bruxism: an unsolved problem in dental medicine. acta stomatol croat 2004; 38(1): 93-6 9. legg jw. enlargement of the temporal and masseter muscles on both sides. trans pathol soct london 1880; 31: 361-6. 10. hanly dj, horton ce, adamson je, mladick ra, carraway jh. benign massteric hypertrophy. berl chir plastica 1976; 3:185-91. 11. sreejith g, pillai b. masseteric hypertrophy: an orthodontic perspective. j indian orthod society 2012; 46(4): 233-7. 12. ferrera la. focus on body mass index and health research. 1st ed. new york: nova science publishers, inc.: 2006. pp.79. 13. sushma r, ravi ms. masseter muscle thickness in different skeletal morphology: an ultrasonographic study. indian j dent res 2010; 21(3): 402-7. 14. kubota m, nakano h, sanjo i, satoh k, sanjo t, karoegai t, ishikawa f. maxillofacial morphology and masseter muscle thickness in adults. european j orthod 1998; 20: 535-542. 15. kiliaridis s, georgiakaki i, katsaros c. masseter muscle thickness and maxillary dental arch width. europ j orthod 2003; 25: 259263. 16. satirogolu f, arun t, isik f. comparative data on facial morphology and muscle thickness using ultrasonography. eur j orthod 2005; 27:562-567. 17. kiliaridis s, mills cm, antonarakis gs. masseter muscle thickness as a predicative variable in treatment outcome of the twinblock appliance and masseteric thickness changes during treatment. orthod craniofac res 2010; 13: 203-13. 18. palinkas mi, nassar ms, regab sc. age and gender influence on maximal bite force and masticatory muscle thickness. arch oral biol 2010; 55(10): 797802. saria f.doc j bagh college dentistry vol. 28(2), june 2016 incidence of cleft lip pedodontics, orthodontics and preventive dentistry 139 incidence of cleft lip and palate in al-ramadi city (descriptive epidemiological study) saria dhakir mahmood, b.d.s. (1) ausama a. al-mulla, b.d.s., dr. d. sc. (2) abstract background birth defects are one of the causes of pediatric disability and mortality in all around the world. data on birth defects from population-based studies originating from developing countries are lacking. cleft lip (cl), cleft lip and palate (clp), and isolated cleft palate (cp), collectively termed oral clefts, occur in all races, both sexes, and all socioeconomic groups and vary internationally (1). the main aim of this research is to establish the frequency of cleft lip and/or palate in the population of the al-ramadi city, and to characterize the demographic features of affected individuals and find possible risk factors. materials and methods we conducted a survey of the educational maternal and pediatric hospital in al-ramadi city. the sample population comprised all 5100 babies born at al-ramadi city during the 5 months period 1 january 2013 to 31 may 2013. statistical tests used pearson’s chi-square test, student’s t-test and spearman’s correlation coefficient test according to the type of parameter tested. results: during the study period 15 babies were born with oro-facial cleft. the overall incidence of cleft lip and palate was 2.94 per 1000. cleft palate was significantly more frequent in male than female babies (p = 0.81). conclusions: a high incidence of facial clefts in this city was seen. this change may be attributed to the wars that occur in iraq in the last years so increased pollutions and decreased prenatal care in the iraqi population as part of social and health-related behavior changes. keywords: cleft lip, cleft palate, congenital anomalies, epidemiology, iraq health. (j bagh coll dentistry 2016; 28(2):139-144). introduction definition and terminology larry (2) defined a cleft as a congenital abnormal space or gab in the upper lip, alveolus or palate. cleft also can be defined as a crack, split, or an opening made by a cleavage or something cut into two. it defines cleft palate as a congenital malformation in the roof of the mouth because the two sides of the palate did not join before birth (3). cleft lip is a disorder originated as a failure of fusion of the frontal process with the maxillary process, at about the 7th weeks of development, while cleft palate is due to failure of fusion of secondary palate that mean non union of palatal process of both left & right side of maxillary process (4). danila et al. (5) states that "clp is a complex multi-factorial disorder, is one of the most common congenital malformations with a prevalence of 0.16 to 2.35 per 1000 births in caucasian population". embryology human face develops as early as the 14th day of intrauterine life. it formed from processes surrounding the primitive mouth which are frontal process forming the forehead and the nose, the mandibular process forms the lower lip, lower jaw and lower cheek. (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. the maxillary processes form the upper lip, jaw and cheek. from the maxillary process two palatal shelves formed posterior to the incisive foramina. these shelves first oriented vertically then become horizontally to join in the midline forming the secondary palate. the primary palate (anterior to the incisive foramina) formed from the nasal prominence (which is formed from the maxillary process), also the nasal prominence form the philtrum of the upper lip and the middle part of the nose. all these events occur between the 4th and 8th week of intrauterine life. any interruption of any of these events may cause clefts (11-14). incidence incidence denotes the number of cases entering a population, i.e. new cases in some time period (6). clp considered approximately the forth most common craniofacial birth defect (7). according to peggy et al. (8), clp affect 1:600 births in usa. while cawson (9) found the incidence of cl in usa is 1: 1000. the incidence of clp is: in denmark 1:500, usa 1:1200, france 1:800 and in iraq 1:1000 (4). according to loh (10), the prevalence of syndromic or nonsyndromic clp is 1.30 in chinese. many studies were conducted to show the influence of the genetic factors i.e. familial background, as well as different environmental factors (e.g. nutrition, drugs, psychological conditions of the mother, types of cleft, parental age and seasonal effect) on the incidence of cleft lip and/or palate. j bagh college dentistry vol. 28(2), june 2016 incidence of cleft lip pedodontics, orthodontics and preventive dentistry 140 table 1: incidence of oro-facial clefts according to some studies etiology genetic factors there is a family history in 40% of cleft lip and palate and 20% of cleft palate cases, so there is a genetic predisposition that may possibly be triggered by environmental factors (9). twins and infants whose parents were first cousins had a stronger risk of clo than clp (15). the genetic factors include two categories: first is the single mutant gene: 80% of those syndromes are the result of a single mutant gene, others said it is about 60% (16,17). single mutant gene might be autosomal dominant, autosomal recessive and xlinked (18). second is the chromosomal aberrations: the best example of the syndromes that are associated with these chromosomal aberrations are rare syndromes includes etrisomy, d-trisomy and the xxxxy syndromes in which cleft palate and/or cleft lip are present in high frequency (19). environmental factors mean the exogenous factors from the surrounding environment that can cause a defect or disease. embryonic development is an interaction of genetic and environmental factors (20). environmental factors may include: drugs (21), nutritional deficiency (22). pathologic status of the mother if she had diabetes, hyperand hypotension, infection with rubella (german measles) (20,23), increased mother's weight (24), exposure to radiation (25). psychological and emotional stress (26), cigarette smoking and alcohol drinking (23), occupation of the parents (27) which give a clue about the parents' education and socioeconomic status. problems associated with cleft lip and palate feeding problem most babies with a cleft palate cannot generate enough sucking pressure for breastfeeding. to take advantage of the health benefits of breast milk, many mothers elect to feed their baby breast milk in a bottle with a cleft palate nipple (28). presence of cleft lip and palate can compromise maternal nursing which will compromise baby oral health and the surgical/rehabilitation process. nearly 98.25% of mothers used bottle feeding with milk and other sucrose liquids at one to ten times frequency (29). baby body weight feeding difficulties resulting from the labiopalatine malformation itself or from the inability to take nutrients during the first months of life, as well as infectious processes in the upper airways or middle ear, are factors causing growth deficiency in children with these malformations (30). psychological and social problems children with orofacial clefts are probably at risk to develop problems in their social-emotional functioning as a result of their condition, they do not experience major psychosocial problems, but some specific problems may arise such as dissatisfaction with facial appearance, depression, and anxiety (31). audiological aspect in cp baby, eustachian tube will be closed ,so when this function is disrupted the middle ear will be a closed space so serous fluids will accumulate and result in otitis media (or called sappurative otitis media),which resulted in chronic otitis media and this is a threat to the hearing (32). speech problems many speech problems are associated with clp .retardation of consonant sounds is common, so much language activity is omitted. hypernasality is usual in those patients and remain even after surgical palate repair .in soft palate clefts the velopharyngeal mechanism can not function because of the discontinuity of the musculatures attachment thus can not elevate to make contact with the pharyngeal wall, so escape of air to nasal cavity is called hypernasality which is difficult to understand (2). authors /year place rates ching and chung,1974 hawaii 2.45 tregbulem, 1982 nigeria 0.369 morrison,1985 south africa 0.33 natsume et al,1987 japan 2.06 ernest,1988 hungary 1.55 kumar et al , 1991 saudi arabia 0.3 stoll et al, 1992 china 1.11 molina et al, 1993 mexico 1.32 amidei et al, 1994 colorado city-usa 0.81 rosche et al, 1998 magdeurg-germany 1.85 yi-nn et al, 1999 singapore 2.07 hewson and mcnamara, 2000 ireland 1.14 rajabian and sherkat,2000 iran 1.03 al-sadoon et al,2002 iraq-basra 0.79 salvi et al,2003 switzerland 1.5 al-omari and al-omari,2004 jordan 1.39 suleiman et al,2005 sudan 0.9 rajabian and aghaei,2005 iran 0.8 eldad et al,2012 israel 1.067 present study ,2013 iraq 2.94 j bagh college dentistry vol. 28(2), june 2016 incidence of cleft lip pedodontics, orthodontics and preventive dentistry 141 dental problems complete bilateral cleft lip and palate (bclp), the prevalence of missing tooth reaches 100% (33). observes extremely high incidence of enamel hypoplasia in the incisors of both dentitions in patients with clefts (34). dahllof et al (35) have found a high incidence of enamel hypermineralisation in cleft lip and palate patients. ranta (36) said that there may be a delay in the dental development on the cleft side leading to delayed eruption times. the lateral incisor on the affected side may be located in either portion of the alveolar bone adjacent to the cleft. the tooth or teeth will often be displaced palatally and rotated (37). as a child with a cleft grows, sometimes the upper jaw does not grow as much as the lower jaw. if this occurs, the resulting differences in the upper and lower dental arches can present problems in appearance, speech, or chewing (38). respiratory problem various respiratory problems have been reported to be associated with cleft palate patients, due to the fact that cleft palate patients suffer from feeding difficulties accompanied with regurgitation of milk and saliva into the nasopharynx leading to repeated chest infection (39). associated anomalies o¨zc¸elik et al. (40) reported that t-wood syndrome as one of the congenital anomalies that is associated with clp ndcs (32) reported that clp is known to occur in more than 400 syndromes; e.g.: peirr robin syndrome, 22q11.2 deleation syndrome, van der woude syndrome, stickler syndrome, charge syndrome, godenhar syndrome, downs' syndrome, treacher cholin syndrome, spina bifida, limb defects and congenital heart diseases. in down's syndrome cleft lip or palate is present in approximately 1:200, and in the same trisomy 13 (patau's syndrome cleft lip or palate is present in up to 70% of cases; this syndrome is the most commonly seen in children with clp, it affect one child in 8000-30000 births. materials and methodes 5100 newly born babies were viewed in the educational maternal and pediatric hospital in al-ramadi city for oro-facial clefts for five months between the period (january 2013 to may 2013).all babies were from al-ramadi city and are iraqi in origin. all clefted viewed babies were included including dead and a life babies. examination tools are used in addition to a camera to take photos for the babies. the examination was done with the aid of a pediatric surgeon. this examination include extra-oral examination for head, hands, feet and intraoral examination for tongue, lips, palate, cheek and any neonatal teeth. all information recorded in a specific case sheet designed for this study. classification of clefts depends on millard classification1976. statistical analysis was performed with microsoft office excel 2007r and spss version 14 software. statistical tests used pearson’s chisquare test, student's t-test and spearman’s correlation coefficient test according to the type of parameter tested. results 1. clefts seems to affect males more than females with a ratio m:f =1.5:1, and the first order affected more (40%) most of the affected babies were of average weight (46.67%). 2. congenital anomalies was present in (66.67%) of cleft patients. 3. highest percentage of patients with cleft were born to the younger parents (30 years and below), and (86.66%) of mothers' were house wives. consanguinity between the parents was (46.67%). 4. mothers did not reported smoking or alcohol drinking. 5. the prevalence of normal delivery was (73.34%). previous abortion present in (46.67%), history of threatened abortion was present in (13.34%) of the clefted children s' mothers. 6. (33.34%) of cleft mothers had pregnancy disease. 7. (46.67%) of the affected children mothers had poor food intake during their pregnancy. discussion incidence of cleft lip and/or palate according to the results in this study the incidence of cleft lip and /or palate in al-ramadi city is nearly (2.9 per 1000) which is nearly close to indians is about 3.6 per 1000 (41); in japan which is 2.06 per 1000 (52); in stockholm-sweden with a prevalence nearly 2.0 (43); in lodsz-poland with a prevalence of 2.0 (44); in singapore with a prevalence of 2.07per thousand (45). however, a great variation was found among the other studies: in nigeria 0.369 (46); australia 1.21(6); japan 1.46 (42); saudi arbia 0.3(47); germany 1.85(48); in iran 1.03 (49). j bagh college dentistry vol. 28(2), june 2016 incidence of cleft lip pedodontics, orthodontics and preventive dentistry 142 cleft lip this study found that cleft lip was found in (13.34%) of the cleft samples. it forms the least common type of clefts. this finding came to be nearly close to ja'afar (50) (11.5%). there are some variations that still exist when compared with other studies like: addekeye and lavery (51) (59.4%); natsume and kawai (52)(41.3%). these differences might be due to different ethnic group, sample size, and sample selection. cleft palate cp group formed the majority of the sample among other groups (60%), which was nearly close to al-zubaidee et al (53) (50%). great variation was found among other studies: aljanabi (54) (34.1%) and ja'afar (50) (23.5%). cleft lip and palate cleft lip and palate was (26.66%) this percentage considered low because of the cleft sample size. other studies reported higher percentage of clp like siegel (55) (62.5%) and padilla and gonzalez (56) (49.4%). these differences might be due to different ethnic group, sample size, and sample selection. associated congenital anomalies this study found that 66.67% of cleft patients had associated congenital anomalies, which was nearly close to that reported by robent et al. (57) (63.4%) and siegel (55) (77.5%), and much higher than conway and wagner (58) (17.5%) and aljanabi (54)(17.7%), this might be due to the sample selection which was carried out. gender this study found that males were affected with clp more than females in a ratio of m:f=1.15:1. baby body weight baby body weight were divided into three groups under weight (<2500g), average weight (2500g-3750g) and over weight (>3750g) (60). the highest percentage of cleft babies was average weight (46.67%). the impairment in weight and length was more apparent in cleft lip and palate and isolated cleft palate children and may be attributed to feeding difficulties compared to the isolated cleft lip group so growth impairment was reported by weight and length deficiency of the cleft baby (61). mother’s age in this study the younger mothers (up to 30 years) were the predominant age group in cleft samples (80%). slavkin (62) reported that the mothers at both ends of the age spectrum were associated with high range of cleft babies. mother’s occupation this study found that the majority of the mothers were housewives (86.66% for cleft samples). this may give us a clue about the educational level which has a great influence on the proper maternal health care which has to be achieved, especially those concerned with careful administration of drugs, proper nutrition and accurate behavior. type of delivery the prevalence of normal deliveries was (73.34%) for cleft samples. for caesarean delivery there was (26.67%).delivery by operation may give us a clue that the mother had difficulty during pregnancy that may affect the child and may lead to a malformation. previous abortion of the cleft patients (46.67%) had previous abortion. previous history of abortion may give a clue that the mother is susceptible to abortion during pregnancy and the pregnancy is difficult and the mother take drugs like abortion preventatives which might lead to malformations. relativity 46.67% of cleft samples parents were relatives. ingalls et al. (63) stated that "cleft lip and cleft palate occurred with a higher frequency among relatives of patients than expected in the general population". environment during pregnancy smoking this study showed no significant association between maternal smoking and clefts since all the mothers were non-smokers. who (64) reported that maternal cigarette smoking during pregnancy has been associated with a moderate increase in the risk of orofacial clefts. alcohol drinking in this study, none of the mothers were alcohol drinkers. romitti et al. (65) found maternal cigarette smoking and alcohol consumption are considered as risk factors for cleft lip and/or palate. j bagh college dentistry vol. 28(2), june 2016 incidence of cleft lip pedodontics, orthodontics and preventive dentistry 143 threaten abortion of the cleft group mothers, (13.34%) gave a history of threatened abortion during the first trimester of pregnancy; bleeding and exhaustion were the main causes. saxen (66) mentioned that threaten abortion could be one of the factors that cause cleft lip and/or palate. diseases during pregnancy of the cleft mothers (33.34%) had one or more diseases during pregnancy. this may include urinary tract infections, hypertension, diabetes, asthma, epilepsy, typhoid fevere, pregnancy sickness (hypotension, hypoglycemia, morning nausea, stomach acidity, anaemia …etc). a disease or infection can cause a congenital malformation either by disturbing the normal metabolic processes of the mother or by the effect of drugs administrated to control the pathologic condition (20). drug intake according to this study, the pregnant women took more than one type of drugs during pregnancy like multivitamins, antibiotics, antiepileptic drugs, insulin, sedatives …etc. all cleft mothers took drugs during the 1st trimester of pregnancy. multivitamins was the most taken drugs by the pregnant women .nelson and forfar (67) reported that the embryonic development could be affected by various types of drugs e.g. aspirin, antacids, antibiotics. nutritional status poor food intake during the pregnancy was reported in (46.67%) of the cleft group mothers. the nutritional deficiency of the mother can increase or decrease the teratogenic effect of exogenous agents and the caloric deficiencies can produce clefts as well as improper intake of certain essential ingredients in food can have an independent potential in disturbing the normal development of the embryo (20). references 1. aljohar a, ravichandran k, subhani s. pattern of cleft lip and palate in hospital-based population in saudi arabia: retrospective study. cleft palate– craniofac j 2008; 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3: 284-90. 59. abdul-khaliq ar. clinicogenetic study for cleft lip and/or palate patients (epidemiological study). a master thesis, department of orthodontics, college of dentistry, university of baghdad, 2003. 60. zarate ya, martin lj, hopkin rj, bender pl, zhang x, saal hm .evaluation of growth in patients with isolated cleft lip and/or cleft palate official j american academy of pediatrics. 2010; 8:125-543. 61. luiz c, montagnoli a, barbieri h, lazarini m, luiz ds. growth impairment of children with different types of lip and palate clefts in the first 2 years of life. jornal de pediatria 2005; 81(6): 461-5. 62. slavkin hc. incidence of cleft lips, palates rising. j am dent assoc 1992; 123(11): 61-5. 63. ingalls th, taube ie, klingberg ma. cleft lip and cleft palate. epidemiologic considerations. plast reconst surg 1964; 34: 1-10. 64. romitti pa, lidral ac, munger rg, hirsch s, burns l, murry jc. candidate gene for non-syndromic cleft lip and palate and maternal cigarette smoking and alcohol consumption: evaluation of genotype environment interaction from application based case control study of orofacial clefts. teratol 1999; 59(1): 59-70. 65. saxen i. epidemiology of cleft lip and cleft palate; an attempt. to rule out chance correlations. br j prev soc med 1975; 29(2): 103-10. 66. nelson mm, forfar jo. associations between drugs administered during pregnancy and congenital abnormalities of the fetus. br med j 1971; 1: 523-7. 26. arwa f.doc j bagh college dentistry vol. 27(4), december 2015 an evaluation of pedodontics, orthodontics and preventive dentistry 155 an evaluation of ion released from two brands of brackets in three types of mouthwashes arwa gh. ahmed, b.d.s (1) iman i. al-sheakli, b.d.s, m.sc. (2) abstract background: mouthwashes used widely as ancillary to mechanical oral hygiene methods. little information provided about the effect of mouthwashes on ions released from orthodontic brackets. therefore, the present study has been established to evaluate the effect of different mouthwashes on the ion release and the biocompatibility of two brands of brackets. materials and methods: eighty premolar stainless steel brackets were used (40 brackets from dentaurum and 40 brackets orthotechnology company). they were subdivided into four subgroups (n=10) according to immersion media (deionized distilled water, corsodyl, listerine and silca herb mouthwashes). each bracket was stored in a closely packed glass tube filled with 15ml of the immersion media and incubated for 45 days at 37ºc. chromium, nickel, copper and manganese ions release were measured using atomic absorption spectrophotometer, while iron ions release were measured by using iron kit and spectrophotometer. for statistical analysis, t-test, analysis of variance (anova) and least significant difference (lsd) were used. results: the results revealed that the ions released from dentaurum brackets were significantly higher than that from orthotechnology brackets in all type of immersion media except for chromium ions in corsodyl mouthwash. the release of copper and chromium ions was significantly higher in listerine and corsodyl mouthwashes than in deionized distilled water being related to the ph of the immersion media. while, the release of iron, nickel and manganese ions in the three mouthwashes was comparable to that in deionized distilled water. conclusions: the amount of released ions were below toxic levels and did not exceed the daily dietary intake, but it may be recommended to avoid prolonged use of listerine and corsodyl mouthwashes in patients allergic to chromium. key words: brackets, mouthwashes, ions release, corrosion. (j bagh coll dentistry 2015; 27(4):155-160). introduction plaque control is the major consensus during orthodontic treatment to prevent the occurrence of cavities and periodontal inflammation (1). therefore during orthodontic treatment, practitioners recommend that their patients use mouthwashes, since most of them are adolescents who do not always follow a satisfactory oralhygiene regimen and have a high risk of dental caries (2). in the oral environment, orthodontic appliances are exposed to potentially damaging physical and chemical agents which may cause metallic corrosion (3). recent improvements in the composition and quality of orthodontic alloys have significantly increased their biocompatibility and stability inside the oral cavity. however the release of metal ions from dental alloy is a phenomenon that cannot be avoided; it’s difficult to find a material that will be fully stable within an organism and will show no sign of biodegradation (4). therefore during the last decade, there has been increased interest among dental and biomedical professionals in the side effects associated with the use of biomaterials, especially the metallic materials; fixed appliances in orthodontics involve brackets and archwires (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of orthodontics, college of dentistry, university of baghdad. that are metallic. these brackets are exposed to the oral cavity, which is a potentially hostile environment where electrochemical corrosion phenomena can occur. thus, orthodontic brackets and other auxiliary components should be made of highly corrosion resistant metals and metal alloys (5). materials and methods the sample consists of 80 premolar stainless steel brackets, which were divided according to their manufacture (dentaurum and orthotechnology) into two groups each group contained 40 brackets that each subdivided into four subgroups, one of these subgroup immersed in 15 ml of deionized distilled water (controlled group), ph 7.5, while the second one immersed in 15 ml of corsodyl mouthwash, ph 4.49, furthermore the third one immersed in 15 ml of listerine mouthwash, ph 3.8 and finally the forth one immersed in 15 ml of silca herb mouthwash, ph 7.85. after that each individual capped – glass tube which was marked with specific color that represents the brand of bracket was filled with 15 ml of each different mouthwash and deionized distilled water using measuring glass cylinder then all the capped – glass tubes were incubated in an incubator set at a constant temperature of 37°c for 45 days. j bagh college dentistry vol. 27(4), december 2015 an evaluation of pedodontics, orthodontics and preventive dentistry 156 after incubation period, the samples were prepared for estimation of ions concentration included copper, manganese, nickel, chromium and iron by using atomic absorption spectrophotometer following standardized procedure. the concentrations of copper, nickel, and chromium were determined by using flame atomic absorption spectrophotometer at wave lengths for each element, while the concentration of manganese was determined by using furnace atomic absorption spectrophotometer and finally concentration of iron was determined by colometric method with spectrophotometer, iron kit used. results the amount of ions released from the stainless brackets were compared between two different brands (dentaurum and orthotechnology) in each mouthwash and among different widely used mouthwashes (corsodyl, listerine and silca herb) and deionized distilled water that used as a control medium. iron ions released: reviewing table1, the results revealed that the amount of iron ions released, in all types of mouthwashes, from the brackets of dentaurum company were higher than that released from orthotechnology company with a highly significant difference as indicated by independent sample t-test. the amount of iron ions released from the brackets of dentaurum company were higher in listerine, followed by deionized distilled water, silca herb and the least amount were released from corsodyl mouthwash with a highly significant difference as indicated by anova test. regarding orthotechnology company, the amount of iron ions released were higher in deionized distilled water followed by silca herb then listerine and corsodyl with a highly significant difference. for both companies, lsd test showed a highly significant difference when comparing the iron ions released between each two mouthwashes. chromium ions released: as can be seen in table 2, the results revealed that the amount of chromium ions released, in all types of mouthwashes, from the brackets of dentaurum company were higher than that released from orthotechnology company with a highly significant difference as indicated by independent sample t-test except for silca herb mouthwash which showed non-significant difference (p>0.05) and in corsodyl mouthwash orthotechnology showed higher amount of the ions. the amount of chromium ions released from the brackets of dentaurum company were higher in listerine followed by corsodyl, deionized distilled water and the least amount were released from silca herb mouthwash with a highly significant difference as indicated by anova test. regarding orthotechnology company, the amount of chromium ions released were higher in listerine followed by corsodyl then deionized distilled water and silca herb with a highly significant difference. for both companies, lsd test showed a highly significant difference when comparing the chromium ions released between each two mouthwashes. nickel ions released: reviewing table 3, the results revealed that the amount of nickel ions released, in all types of mouthwashes, from the brackets of dentaurum company were higher than that released from orthotechnology company with a highly significant difference as indicated by independent sample t-test. the amount of nickel ions released from the brackets of dentaurum company were higher in deionized distilled water followed by corsodyl, listerine and the least amount were released from silca herb mouthwash with a highly significant difference as indicated by anova test. regarding orthotechnology company, the amount nickel of ions released were higher in deionized distilled water followed by corsodyl then silca herb and listerine with a highly significant difference. for both companies, lsd test showed a highly significant difference when comparing the nickel ions released between each two mouthwashes. copper ions released: reviewing table 4, the results revealed that the amount of copper ions released, in all types of mouthwashes, from the brackets of dentaurum company were higher than that released from orthotechnology company with a highly significant difference as indicated by independent sample t-test. the amount of copper ions released from the brackets of dentaurum company were higher in listerine followed by corsodyl, deionized distilled water and the least amount were released from silca herb mouthwash with a highly j bagh college dentistry vol. 27(4), december 2015 an evaluation of pedodontics, orthodontics and preventive dentistry 157 significant difference as indicated by anova test. regarding orthotechnology company, the amount of copper ions released were higher in listerine followed by deionized distilled water then corsodyl and silca herb with a highly significant difference. manganese ions released: reviewing table 5, the results revealed that the amount of manganese ions released, in all types of mouthwashes, from the brackets of dentaurum company were higher than that released from orthotechnology company with a highly significant difference as indicated by independent sample t-test. the amount of manganese ions released from the brackets of dentaurum company were higher in listerine followed by deionized distilled water, silca herb and the least amount were released from corsodyl mouthwash with a highly significant difference as indicated by anova test. regarding orthotechnology company, the amount of manganese ions released were higher in listerine followed by deionized distilled water then silca herb and corsodyl with a highly significant difference. for both companies, lsd test showed a highly significant difference when comparing the manganese ions released between each two mouthwashes. table (1): iron release from brackets of different companies in different mouthwashes. groups dentaurum orthotechnology company difference mean s.d. min. max. mean s.d. min. max. t-test d.f =18 p-value d.w 797.810 10.574 780.4 814 705.320 16.381 682.9 725.6 15.001 0.000*** corsodyl 673.873 5.852 665.6 683.28 591.830 5.411 580.06 598.18 32.549 0.000*** listerine 816.134 9.103 803.9 829.5 676.891 5.080 667.67 683.28 42.239 0.000*** silca herbal 739.890 9.429 728.6 756 687.160 8.122 679.8 703.7 13.399 0.000*** group difference f-test=518.72 d.f =39 p-value=0.000*** f-test= 260.62 d.f =39 p-value=0.000*** table (2): chromium release from brackets of different companies in different mouthwashes groups dentaurum orthotechnology company difference mean s.d. min. max. mean s.d. min. max. t-test d.f =18 p-value d.w 109.8 6.88 99 119 101.5 3.92 95 106 3.315 0.004*** corsodyl 270.1 4.23 263 275 314.7 4.60 308 320 -22.58 0.000*** listerine 945.2 33.19 851 959 610.2 4.26 602 616 31.656 0.000*** silca herbal 79.1 3.14 74 83 77.4 4.60 70 83 0.965 0.347 group difference f-test =5571.43 d.f =39 p-value=0.000*** f-test= 32185.09 d.f =39 p-value=0.000*** table (3): nickel release from brackets of different companies in different mouthwashes groups dentaurum orthotechnology company difference mean s.d. min. max. mean s.d. min. max. t-test d.f =18 p-value d.w 199.2 3.99 193 206 166 3.02 161 170 20.970 0.000*** corsodyl 194.4 2.72 191 199 120.3 4.99 112 128 41.245 0.000*** listerine 144.8 2.49 141 149 101 4.27 94 109 28.040 0.000*** silca herbal 137.2 2.15 134 140 105.4 5.04 99 113 18.360 0.000*** group difference f-test =1232.04 d.f =39 p-value=0.000*** f-test =455.25 d.f =39 p-value=0.000*** j bagh college dentistry vol. 27(4), december 2015 an evaluation of pedodontics, orthodontics and preventive dentistry 158 table (4): copper release from brackets of different companies in different mouthwashes groups dentaurum orthotechnology company difference mean s.d. min. max. mean s.d. min. max. t-test d.f =18 p-value d.w 282.2 4.54 277 291 101.3 5.29 93 110 82.030 0.000*** corsodyl 739.9 2.56 737 745 81.1 2.42 77 85 591.090 0.000*** listerine 901.1 8.35 891 913 150 10.54 130 160 176.660 0.000*** silca herbal 115 4.78 109 121 54.7 3.30 51 61 32.804 0.000*** group difference f-test =46080.96 d.f =39 p-value=0.000*** f-test =416.45 d.f =39 p-value=0.000*** table (5): manganese release from brackets of different companies in different mouthwashes discussion brackets from two different manufactures were used, which are widely used in orthodontic department in the college of dentistry at baghdad university. adhesive resins were not used on the base of brackets in this study to prevent other sources of ion release (6). therefore, the exposed surface for ion release was approximately twice that of clinical conditions because the bracket bases would be covered with a bonding material in clinical use (3,7). mouthwashes usually used twice a week for about 1 minute, it is also recommended that after mouthwash the patient must not eat, drink, and rinse, so the components of mouthwash are present for a long time, and it is difficult to determine the exact duration of contact between brackets and mouthwashes. in this study we assumed that each time the mouthwash was present for 6 hours in a patient’s mouth (24 months, twice a week about 69,000 minutes), therefor the brackets were immersed in mouthwashes and incubated for 45 days (45 days about 64,000 minutes) (3,7,8). the level of ions released from different companies results revealed that the amount of released, in all types of mouthwashes, from the brackets of dentaurum company was higher than that released from orthotechnology company with a highly significant difference as indicated by independent sample t-test except for chromium ion released in silca herb mouthwash was nonsignificant differenceand in corsodyl mouthwash orthotechnology showed higher amount of the ions, this agree with lin et, al., (9) who found that the brand of the commercial ss brackets had a significant influence on the corrosion resistance, and the difference in corrosion resistance might be related to the different surface characterizations, such as surface residual stress and metallurgical factors, produced during the various manufacturing processes, instead of the surface roughness and preexisting defect. for nickel ions released from brackets in the various solutions, the maximum release were in deionized water and the next highest were in chlorhexidine mouthwash, this agrees with patel et al and danaei et, al., (3,7). the reason might be because deionized water has an extremely low concentration of ions, and the lack of ions makes this solvent one of the most aggressive solvents known, the corrosion of different metals and alloys as a result of immersion in deionized water has been studied (10) while the group immersed in chlorhexidine this could be attributed to the corrosiveness of chlorhexidine compared with the other two mouthwashes; this agrees with previous reports about the irritating effects of chlorhexidine (3,7,11,12). furthermore listerine and silca herb mouthwashes revealed less amount of nickel ions, this may be due to the composition of mouth wash itself this agrees with house et, al., (13), who stated that the level of corrosion of any metal depends on the chemistry of the solvent in which it is groups dentaurum orthotechnology company difference mean s.d. min. max. mean s.d. min. max. t-test d.f = 18 p-value d.w 2.746 0.051 2.68 2.83 2.316 0.049 2.21 2.37 19.128 0.000*** corsodyl 1.435 0.028 1.39 1.47 0.996 0.043 0.92 1.06 26.945 0.000*** listerine 3.921 0.039 3.85 3.97 3.249 0.039 3.18 3.29 38.528 0.000*** silca herbal 2.081 0.037 2.01 2.13 1.833 0.044 1.77 1.91 13.698 0.000*** group difference f-test= 7159.71 d.f = 39 p-value=0.000*** f-test= 4582.27 d.f = 39 p-value=0.000*** j bagh college dentistry vol. 27(4), december 2015 an evaluation of pedodontics, orthodontics and preventive dentistry 159 immersed. while for orthotechnology company the release of nickel ions were also the greatest in deionized distilled water followed by chlorhexidine, but the difference was that the amount of nickel ions released in silca herb mouthwash higher than in listerine mouthwash this may be due to difference in the reaction between the alloys from different companies with the mouthwashes. regarding orthotechnology company the release of nickel ions were also the greatest in deionized distilled water followed by chlorhexidine, but the difference was that the amount of nickel ions released in silca herb mouthwash higher than in listerine mouthwash this may be due to difference in the reaction between the alloys from different companies with the mouthwashes. iron ions released from the brackets of dentaurum company were higher in listerine followed by deionized distilled water, silca herb and the least amount were released from corsodyl mouthwash with a highly significant difference, listerine mouthwash has the lowest ph this may be the cause of higher release, this agrees with huang et, al., (14) who reported that the metal ions release were more when the brackets were placed in acidic environment, but if we follow that report chlorhexidine must be the second in the level of iron ions release add to that when noticing the amount of ions released from orthotechnology company, which were higher in deionized distilled water followed by silca herb, then listerine and corsodyl with a highly significant difference, so this means that the release of iron ions were not related to the ph of the solution. regarding copper ions released from the brackets of dentaurum company were higher in listerine followed by corsodyl, deionized distilled water and the least amount was released from silca herb mouthwash with a highly significant difference, this agrees with the studies that revealed the levels of released ions were gradually increased with decreasing solution ph. these results agree with the finding of and kuhta et, al. (4) and staffolani et, al. (15). in the other hand regarding orthotechnology company, the amount of copper ions released were higher in listerine followed by deionized distilled water then corsodyl and silca herb with a highly significant difference, this return us to the same point that the ions release depend on the reaction of alloy to the solution, this agrees with the result of duffó and farina (16) who showed that the aggressiveness of the different liquids is independent on the ph of the solution. now for chromium ions released from the brackets of dentaurum company which were higher in listerine followed by corsodyl, deionized distilled water and the least amount were released from silca herb mouthwash with a highly significant difference, and it was the same sequence for orthotechnology company, these results agree with the study of okazaki and gotoh(17) which revealed that with decreasing ph (ph ≤ 6), the quantity of cr released gradually increased and bottomed out at ph 6. finally the amount of manganese ions released from the brackets of dentaurum company were higher in listerine followed by deionized distilled water, silca herb and the least amount were released from corsodyl mouth wash with a highly significant difference and it was the same findings for orthotechnology company, this results do not agree with the study of huang et, al., (18), but chlorhexidine mouthwash has lower ph value than deionized distilled water and silca herb mouthwash this again return us to the findings of duffó and farina (16) who showed that the aggressiveness of the different liquids is independent on the ph of the solution.. the level of ions released from different companies, results revealed that the amount of released, in all types of mouthwashes, from the brackets of dentaurum company was higher than that released from orthotechnology company with a highly significant difference as indicated by independent sample t-test except for chromium ion released in silca herb mouthwash was nonsignificant difference this agree with lin et, al.,(9) who found that the brand of the commercial ss brackets had a significant influence on the corrosion resistance, and the difference in corrosion resistance might be related to the different surface characterizations, such as surface residual stress and metallurgical factors, produced during the various manufacturing processes, instead of the surface roughness and preexisting defect. the who recommended daily doses (rdd) for the following elements are: ni, 25-35 μg/day; cr, 50-200 μg/day; mn, 2.5-6 mg/day; fe, 10-18 mg/day(10). the amount of ions released did not exceed the recommended daily doses. however, even a small amount of release might produce sensitivity when the orthodontic appliances are in place for 2 to 3 years. because symptoms can develop several years later, nickel hypersensitivity should be observed on a long-term basis (18). certain ions such as nickel and chromium can cause allergic reactions and toxicity symotoms(19). these symptoms can stay for short time but intense or may be moderate but long lasting, furthermore these symptoms might be cured or can become chronic problem. since the toxicity of j bagh college dentistry vol. 27(4), december 2015 an evaluation of pedodontics, orthodontics and preventive dentistry 160 nickel is a concern, and the natural capacity to eliminate nickel exceeds the accumulation capacity, the risks are minimal (20). however, clinicians should be aware that the release of metal ions might cause a local hypersensitivity reaction at oral soft-tissue sites, such as mild erythema or redness with or without edema (21). also, severe gingivitis can be related not only to poor oral hygiene but also to a hypersensitivity reaction to nickel or chromium ions released from stainless steel (22-23). references 1. nassar po, bombardelli cg, walker cs, neves kv, tonet k, nishi rn, bombonatti r, nassar ca. periodontal evaluation of different tooth brushing techniques in patients with fixed orthodontic appliances. dental press j orthod 2013; 18(1): 76-80. 2. schiff n, grosgogeat b, lissac m, dalard f. influence of fluoridated mouthwashes on corrosion resistance of orthodontics wires. biomaterials 2004; 25: 4535-42. 3. patel r, bhanat s, patel d, shah b. corrosion inhibitory ability of ocimum sanctum linn (tulsi) rinse on ion release from orthodontic brackets in some mouthwashes: an invitro study. natl j community med 2014; 5(1):135-9. 4. kuhta m, palvin d, slaj m, varga s, varga ml, slaj m. type of archwire and level of acidity: effects on the release of metal ions from orthodontic appliances. angle orthod 2009; 79(1): 102-10. 5. turpin dl. california proposition may help patients in search of better oral health. am j orthod dentofac orthop 2001; 120(2): 97. 6. gwinnett aj. corrosion of resin-bonded orthodontic brackets. am j orthod 1982; 82:441-6. 7. danaei sm, safavi a, roeinpeikar smm, oshagh m, shiva iranpour, omidekhodaf m. ion release from orthodontic brackets in 3 mouthwashes: an in-vitro study. am j orthod dentofac orthop 2011; 139: 7304. 8. jaffer nt. the effect of different mouth washes on the metallic ion release from cobalt-chromium alloy denture base material. int j enh res scitech eng 2013; 2(10): 41-6. 9. lin mc, lin sc, lee th, huang hh. surface analysis and corrosion resistance of different stainless steel orthodontic brackets in artificial saliva. angle ortho 2006; 76: 322-9. 10. szakalos p, hultquist g, wikmark g. corrosion of copper by water. electrochem solid state lett 2007; 10: c63-7. 11. dartaroztan m, akman aa, zaimoglu l, bilgiç s. corrosion rates of stainless steel files in different irrigating solutions. int endod j 2002; 35: 655-9. 12. ozcan t, sonat b, dartar €om bilgic¸ s. determining the corrosion rates of rotary ni-ti instruments in different irrigating solutions. int endod j 2007; 40: 997. 13. house k, sernetz f, dymock d, sandy jr, irelande aj. corrosion of orthodontic appliances—should we care? am j orthod dentofac orthop 2008; 133: 58492. 14. huang th, ding sj, min y, kao ct. metal ion release from new and recycled stainless steel brackets. eurp j orthod 2004; 26(2): 171-7. 15. staffolani n, damiani f, lilli c, guerra m, staffolani nj, belcastro s. ion release from orthodontic appliances. j dent 1999; 27(6): 449-54. 16. duffó gs, farina sb. corrosion behavior of a dental alloy in some beverages and drinks. material chemistry and physics 2009; 115(1): 235-8. 17. okazaki y, gotoh e. metal release from stainless steel, co-cr-mo-ni-fe alloys in vascular implants. corrossci 2008; 50(12):3429-38. 18. huang th, yen cc, kao ct. comparison of ion release from new and recycled orthodontic brackets. am j orthod dentofac orthop 2001; 120:68-75. 19. mockers o, deroze d, camps j. cytotoxicity of orthodontic bands, brackets and archwires in vitro. dent mater 2002; 18(4): 311-7. 20. schmalz g, garhammer p. biological interactions of dental cast alloys with oral tissues. dent mater 2002; 18: 396-406. 21. park hy and shearer tr. in vitro release of nickel and chromium for simulated orthodontic appliances. am j orthod 1983; 84: 156-9. 22. rickles nh. allergy in surface lesions of the oral mucosa. oral surg oral med oral pathol 1972; 33(5): 744-54. 23. schriver wr, shereff rh, domnitz jm, swintak ef, civjan s. allergic response to stainless steel wire. oral surg oral med oral pathol 1976; 42: 578-81. j bagh college dentistry vol. 28(4), december 2016 efficacy of papacarie pedodontics, orthodontics and preventive dentistry 141 efficacy of papacarie in reduction total bacterial count in comparison with the conventional rotary method muna h. al-swaidy, b.d.s. (a) ban a. salih, b.d.s., m.sc. (b) abstract background: the change in the concepts of cavity preparation and the development of reliable adhesive materials lead to the development of alternative methods of caries removal. chemo-mechanical caries removal (cmcr) involves the chemical softening of carious dentin, followed by its removal with manual excavation. the present study was conducted to evaluate clinically the efficiency of caries removal using a new chemomechanical agent (papacarie) compared to the conventional drilling method in reduction of total bacterial count. material and methods: the study is a split mouth design. the sample composes from sixty mandibular deciduous molars teeth in thirty children, between six to nine years of age with bilateral class i deep occlusal carious lesions without pulp involvement. samples of this study were classified into group a and b with thirteen teeth for each. in groupatreatment by papacárie while group b were treated by the conventional drilling method results: the results showed significant different in total bacterial count in period after treatment with papacarie as comparative with drill method for caries remove. conclusions: it was concluded that papacarie could be an effective caries removal method to treat children, particularly those who present with early childhood caries or management problems. keywords: chemo-mechanical caries removal, papacarie, dentin caries, primary teeth. (j bagh coll dentistry 2016; 28(4):141-143) introduction advances in the field of cariology and the philosophy of minimally invasive intervention have led to transformations in the restorative treatment of dental caries. the most striking change involves the selective removal of carious tissue and maximal preservation of healthy dental tissue. traditional methods involving a drill and a bur are incompatible with this philosophy (1,2). the rotary method of caries removal is widely accepted, but it is often associated with long procedure, excessive cutting of uninfected dentin, pain, discomfort, noise, and fear. so, the quest for removal of caries with minimal pain and more tissue preservation has given rise to various alternative caries removal techniques. these include air abrasion, a traumatic restorative therapy, chemo-mechanical system, and lasers (3-6). minimally invasive treatment has been increasingly employed in the management of dental caries, especially in young children (7-9). within the scope of this philosophy, the chemomechanical removal of carious tissue consists of the application of a natural or synthetic agent to dissolve the contaminated tissue and facilitate its removal with the aid of a traumatic mechanical force (10). papacarie is a gel containing papain and chloramine that is used in combination with manual tools for the minimally invasive removal of carious tissue. this method eliminates the need for local anesthesia and the use of a bur, thereby (a) m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, baghdad university. (b) professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. reducing the destruction caused to sound dental tissue (11). the papain-based gel has bactericidal and bacteriostatic properties (12) which may affect the number of microorganisms found in the dentin following the removal of carious tissue (13). the aim of the present study was to analyze the efficacy of papacarie gel compared with the traditional method (tm) (low-speed bur) to remove caries and in reducing the total bacterial count. materials and methods this study is a (split mouth) design. samples of this study were classified into group a and b with thirty teeth for each where two methods of caries removal were compared for the same patient in the same visit. ethical aspects and subject selection parents or legal guardians received detailed information on the study and signed a statement of informed consent, permitting the participation of their children. children seeking treatment at the specialist healthy dental paediatric centre in alalwayia healthy centre was submitted to initial clinical examinations. the selection criteria were as follows: an absence of systemic illness, adequate behavior, and caries in the dentin of bilateral two deciduous molar with class i occlusal carious lesions without pulp involvement according tocriteria described by muhlemann et al. (14). following the application of these criteria, the sample included j bagh college dentistry vol. 28(4), december 2016 efficacy of papacarie pedodontics, orthodontics and preventive dentistry 142 60 deciduous teeth in 30 children (2 teeth per child) aged 6 -9 years old. clinical procedure a split-mouth design was performed to compare the efficacy of papacarie® gel (fórmula &ac˛ ão, são paulo, sp, brazil) and the traditional caries removal method (low-speed bur). for each individual, one tooth was randomly selected for one treatment and the other tooth automatically received the other form of treatment. group 1 = chemo-mechanical removal with papacarie group 2= traditional caries removal with a lowspeed bur. group i: using the chemo-mechanical method the papacarie was taken out of the refrigerator ten minutes before treatment to reach room temperature. application of rubber dam on selected tooth and the carious cavity was filled with papacarie. the gel was allowed to work for 4060 seconds. the softened decayed dentin was scraped away with a blunt excavator in a pendulum movement according to manufactory instruction. the softened tissue was scraped away but not cut within. the gel was reapplied when necessary and when present unsupported enamel remove when remove undermine carious dentine. cavity was examined by visual inspection and tactile sensation using a mirror and an explorer to assess caries removal (15). caries was considered removed when the explorer did not stick in dentin and did not give a tug-back sensation. group ii: using conventional drilling method after admiration of local anesthesia caries was removed using a low speed hand piece with size 8 round burs. the cavities were checked for remaining caries using the same criteria used for the chemo-mechanical caries removal. after caries removal by either method, cavities were restored using composite resin according to the manufacturer’s instructions (16). assessment producers for each technique all these samplescollected before and after caries remove by spoon excavator in same amount, transported to the microbiological investigation laboratory by place in flask containing transported media. transported media dilated in about 3 ml of normal saline for each transported media. each 1ml boarded in petridish with nutrient agar by using glass disposable pipette according to poured plate culturing method after that place in incubator at 35c for 2 days and compares the result by collected number of colony formed in dish (17). results table (1) and figure (1) show the descriptive statistic (mean of score and standard deviation) and inferential statistic of bacteriological investigation count at period before and after treatment. mean of bacterial count for papcaire before treatment was (4300.33) and for conventional treatment was (4425.67).while mean after treatment with papacaire was (285.33) and for conventional treatment was (411.33). table 2 represents statistically significant difference 0.027(p<0.05) in total bacterial count between papacarie treatment and conventional treatment group in period after treatment, that means papacarie produce reduction in total bacterial count after treatments in comparison with conventional method. table 1: descriptive statistic to the bacterial count for papcarie and conventional method before and after treatment bact. investigation papacaire conventional no. mean s.d. mean s.d. before 30 4300.33 2307.3 4425.67 1852 after 30 285.33 196.4 411.33 232.20 table 2: summary statistics of bacteriological investigation at pre and post periods of times in each treatment with comparisons significant treatment bact. investigation no. t-test d.f. sig. (*) before papcaire 30 -0.232 58 0.817 ns conventional 30 after papacaire 30 2.269 58 0.027 s conventional 30 (*)s: sig. at p<0.05; ns: non sig. the statistical hypotheses are based on two independent samples t-test. figure 1: bar chart of bacteriological investigation count for studied groups before and after treatment j bagh college dentistry vol. 28(4), december 2016 efficacy of papacarie pedodontics, orthodontics and preventive dentistry 143 discussion chemo-mechanical caries removal methods have an antimicrobial effect; by acting directly on the bacteria, they promote bacterial destruction and consequently remove the etiologic agent. the reduction in bacteria with the use of the papainbased gel may be related to the bactericidal and bacteriostatic action of the gel, which results in the inhibition of gram-negative and gram-positive bacteria (18). result of this study that reported the comparison of total bacterial count for each treatment group in two periods assigned a decrease in bacterial count after treatment of each group. a significant difference that represent papacarie treatment group more effective in reduction of total bacterial count when compare with conventional method based on the findings of the present study, papacarie is an excellent option for the minimally invasive removal of carious tissue, achieving significant reductions in total bacteria, over that observed in the traditional caries removal method, with offering the advantage of less destructive effects on sound dental tissue. this result in agreement with reduction in microorganisms described in previous studies (19-21) references 1. balciuniene i, sabalaite r, juskiene i. chemomechanical caries removal for children. stomatologija 2005; 7: 40–4. 2. mathre s, kumar s, sinha s, ahmed bm, thanawala ea. chemo-mechanical method of caries removal: a brief review. ijcds 2011; 2: 52–7. 3. black rb. air abrasive: some fundamentals. j am dent assoc 1950; 41: 701–10. 4. goldman m, kronman jh. a preliminary report on a chemo-mechanical means of removing caries. j am dent assoc 1976; 93:1149–53. 5. frencken je, pilot t, songpaisan y, phantumvanit p. atraumatic restorative treatment (art): rationale, technique, and development. j public health dent 1996; 56:135–40. 6. keller u, hibst r, geurtsen w, schilke r, heidemann d, klaiber b, et al. erbium: yag laser application in caries therapy. evaluation of patient perception and acceptance. j dent 1998; 26: 649–56. 7. beeley ja, yip hk, stevenson ag. chemo-chemical caries removal: a review of the techniques and latest developments. br dent j 2000; 188: 427–30. 8. maragakis gm, hahn p, hellwig e. clinical evaluation of chemo-mechanical caries removal in primary molars and its acceptance by patients. caries res 2001; 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34(4): 325–30. 21. motta lj, bussadori sk, campanelli ap, silva al, alfaya ta, godoy ch,iand lima navarro mf. randomized controlled clinical trial of long-term chemo mechanical caries removal using papacarie ™ gel. j appl oral sci 2014; 22(4): 307–13. dhamiaa f.doc j bagh college dentistry vol. 25(2), june 2013 periodontal health orthodontics, pedodontics and preventive dentistry140 periodontal health and salivary interleukin -6 among preterm postpartum women dhamiaa m. tajer, b.d.s. (1) wesal a. al-obaidi, b.d.s., m.sc. (2) abstract background: hormonal changes during pregnancy have been suggested to predispose women to gingivitis. furthermore, advance periodontal infection in pregnant women may pose a threat to the placenta and uterus and may increase the like hood of preterm delivery. the aim of this study was to investigate the effect of salivary interleukin -6 (il-6) level and periodontal health among preterm postpartum women. materials and methods: salivary samples were taken from 33 preterm postpartum women (study group) and 33 full term postpartum women (control group). the supernatant salivary samples were assayed using atomic absorption spectrophotometer. plaque, calculus and gingival indices were used for recording the oral hygiene and gingivitis also probing pocket depth was recorded. results: the mean values of plaque index, calculus index probing pocket depth were higher among study group than control group with no statistically significant difference, but a highly significant difference was observed in the mean value of gi between the two groups. the full term women had a higher mean value of salivary il-6 than study group with no statistically significant difference, weak positive correlation was found between salivary il-6 and probing pocket depth in control group. on the other hand, weak negative correlations were noticed between salivary il-6 among study group with plaque index, gingival index, calculus index and probing pocket depth, also between salivary il-6 with pli, gi and cali among control group. however, statistically all correlations were not significant. conclusion: it is concluded that pregnant women during pregnancy required preventive programs directed for improvement of oral health and especially periodontal disease to prevent any pregnancy outcomes such as preterm delivery. keywords: periodontal health, salivary il-6, preterm postpartum women. (j bagh coll dentistry 2013; 25(2):140-142). introduction pregnancy and child bearing are normal occurrence in women life, it involves physicals and physiological changes that profoundly affect even healthy women (1). during pregnancy, women may be particularly amenable to disease prevention and health promotion interventions that could enhance her own oral health or that of her infants. studies documented that effects of hormones on the oral health of pregnant women, suggested that 25-100 percent of these women experienced gingivitis and that 10 percent may develop pyogenic granuloma (2,3). researchers have focused on potential associations between periodontal disease and pregnancy outcomes (4,5). the way in which oral health outcomes may contribute to general health outcomes, therefore periodontal infection, which can be a reservoir inflammatory mediators, may pose a potential threat to the placenta and fetus there by increasing the like hood of preterm delivery (4,6-9). in iraq, many studies were conducted regarding the oral health status of pregnant women (10-14) . yet, no previous studies were conducted to investigate the relation between periodontal disease during pregnancy and preterm delivery, so for this reason this study was designed. (1) master student. department of pedodontics and preventive dentistry, dental college, university of baghdad. (2) professor, department of pedodontics and preventive dentistry, dental college, university of baghdad. materials and methods the salivary il-6 of 66 postpartum women with an age range 20 -25 year old was analyzed. the sample was distributed into two groups: 33 preterm postpartum women (study group) and 33 full term postpartum women (control group). saliva was collected in plastic tubes after stimulation by chewing arabic gums. saliva samples were centrifuged at 4000 rpm for 30 minutes, the clear supernatant was separated by micropipette, stored at (-20°c) in a deep freeze till being assessed by using biosource il-6 which is a solid phase enzyme amplified sensitivity immouno assay (easid). plaque (15), calculus (16) and gingival (17) indices were used for recording the oral hygiene also probing pocket depth was recorded. the expected day of delivery (edd) was calculated by counting back 3 months and adding 7 days to the first day of last menstrual period (naegeles rules) (18). mean and standard deviations were calculated. spearman's correlation coefficient and student’s t-test were used for statistical analysis, at level of significance 0.05. results table 1 illustrates the mean values and standard deviations of pli and cali among preterm and full term groups. although statistically no significant difference were found in pi and cali between study and control groups (p> 0.05), but j bagh college dentistry vol. 25(2), june 2013 periodontal health orthodontics, pedodontics and preventive dentistry141 still the study group had a higher mean values. mean values and standard deviation of gi and ppd among preterm and full term groups were shown in table 2. the study group had a higher ppd mean values. while a highly significant difference was observed in the mean value of gi between the two groups (p< 0.05). table 3 demonstrates salivary il-6 (mean and standard deviation) among preterm and full term groups. statistically, no significant difference was recorded between the two groups (p> 0.05). the correlation coefficients among the variables are illustrated in table 4. weak positive correlation was found between salivary il-6 and ppd in control group, while negative correlations were recorded among the other variables. all the relations were weak and statistically not significant (p>0.05). discussion the current investigations revealed that plaque and calculus accumulation were almost similar in both groups. the differences were statistically not significant between the two groups. this could be attributed to the negligence of oral health in the total sample and no one had received motivation in plaque control or under oral health program. in spite of, no statistically significant difference were found regarding pli and cali between the two groups, but the study group had a high means value than that among control groups, therefore adding for hormonal changes during pregnancy. in general, this could explain that gi was higher among first group and the difference was statistically highly significant. high significant difference was found between preterm and full term women in gi mean value. this result agree with radnai et al study (19), in which hormonal changes due to increased levels of estrogen and progesterone during pregnancy have a special effect on the periodontium (17, 20, 21), as a vascular permeability increase in the gingival tissue and as consequence, bacteria and/ or their products can diffuse through tissue more readily than normally (22). thus, this finding could be explained by the fact that gingivitis had the strongest association with preterm birth. the mechanisms by which periodontal disease could cause preterm birth have still not been cleared, but there is evidence that this relation has biological feasible bases. it has been suggested that the effect of periodontal infection on preterm birth could result from stimulation of fetal membrane on prostaglandin synthesis by cytokines produced by inflamed gingival tissue, or through the effect of endotoxin derived from periodontal infection (6). endotoxin can stimulate prostaglandin production by macrophages in human amnion (23). in this study, preterm postpartum women showed a higher ppd than that among control group with no statistically significant difference between them because of low percentage of periodontal is in the entire study. this study failed to support a proposed link between a preterm birth and periodontitis compared to other studies (4-6,8,9, 24-26). it is important to note that a majority of the women in these studies were 30 years of age or older. this may, in part, explain the strong relationship between periodontitis and preterm birth in that the occurrence of periodontitis increased with age. in young age women, periodontitis is rather uncommon, add to, this result could be due to population difference related to, poorer living condition, including poorer to comprehensive care, different life style. this result agrees with offenbacher et al and moreu et al studies (7, 27) . periodontal bacteria and their virulence factors found in the periodontal pocket, induce a local periodontal host immune response that includes mainly the production of inflammatory cytokines like (interleukin6) and antibodies against the bacteria (28). so the difference between the two groups was statistically not significant in salivary il-6 mean value, due to low occurrence of periodontitis in both groups of this study. this result agrees with the study done by noak et al (29) .weak negative correlation were recorded between salivary il-6 and (gi,cali) among the two groups. therefore, it is responsibility of the dentist and the profession to inform patients about the biologic plausibility that untreated periodontal disease may increase the risk, not only of unfavorable pregnancy out comes, but also the developing conditions that may affect the wellbeing of the offspring. references 1. mac donald c, leveno g, clarce g. maternal adaptations to pregnancy. in: williama obstetric. 20th ed. appleton. and lange, usa. 1997: 192225. 2. amar s, chung k. influence on hormonal variation on the periodontium in women. periodontology 2000; 6: 79-84. 3. mealey b. periodontal implications: medically compromised patients. ann perio 1996; 1(1): 256321. 4. offenbacher s, sieff s, beck j. periodontal associated pregnancy complications. premat. neonat med 1998; 3: 825. 1103-30. 5. dasanayake a. poor periodontal health of the pregnant women as a risk factor for low birth weight. ann perio 1998; 3 (1): 206-12. 6. offenbacher s, katz v, fertik g, periodontal infection as a risk factor for low birth weight. j perio 1996; 67 (suppl 10) 1103-1113. j bagh college dentistry vol. 25(2), june 2013 periodontal health orthodontics, pedodontics and preventive dentistry142 7. offenbacher s, lieff s, boggess k, murtha a, madianos p, champage c, mckaig r, jared h, mauriello s, auten r, herbert w, beck j. mat perio and premj perio 2001; 6: 164-174. 8. jeffocate m, genurs n, reddy m, cliver s, goldberge s, hauth j. periodontal infection and preterm birth result of aprospective study. j am dent ass 2001; 132: 875-880. 9. jeffocate m, hauth j, geurs n, redy m, cliver s, hodgkins p, goldenberg r. periodontal disease and preterm birth: result of a pilot intervention study. j perio 2003; 74: 1214-1218. 10. alguboory i. evaluation of dental health, knowledge, attitude and oral health status of pregnant women in baghdad city. a master thesis, college of dentistry, university of baghdad, 1999. 11. salameh r. the periodontal status during pregnancy and intake of contraceptives. a master thesis, college of dentistry, university of baghdad, 2000. 12. yas b. evaluation of oral health status, treatment needs, knowledge, attitude and behavior of pregnant women in baghdad governorate. a master thesis, college of dentistry, university of baghdad, 2005. 13. alobaidi w. salivary magnesium during pregnancy and labor and its relation to gingivitis. j fac med baghdad 2006; 48(4): 387-390. 14. alzaidi w. oral immune protein and salivary constituents in relation to oral health status among pregnant women. ph.d. thesis, college of dentistry, university of baghdad, 2007. 15. sillness s, loe h. periodontal disease in pregnancy ii. acta odontol scand 1964; 24: 747-759. 16. ramfjord s, massler m, green j, held a, wearhave g. epidemiological studies of periodontal disease. am j public health. 1967; 58: 17131722. 17. loe h, sillness s. periodontal disease in pregnancy. i. acta odontol scand 1963; 21: 533-551. 18. raju g. textbook of obstetrics. 3rd ed. new delhi: s. chand and company ltd. ram nagar: 1996: 51-58, 409445. 19. radnai m, gorzo i, nagy e, eller j, novak t, pal a. caries and periodontal state of pregnant women. part 1 caries status. fogorv sz 2003; 98(2): 53-57. 20. sooryamoorthy m, gower d. hormonal influence on gingival tissue: relationship to periodontal disease. j clin perio 1998; 16: 201208. 21. salmon a, chung k. influence of hormonal variation on the periodontium in women. j perio 2000; 6: 7987. 22. hugoson a. gingival inflammation and female sex hormone. j periodant res 1970; supple 5: 1-18. 23. romero b, hobbins j, mitchell m. endotoxin stimulates prostaglandin e2 production by human amnion. am j obstet gynecol 1988; 71: 227228. 24. dasanayake a, boyd d, madianos o, hill s. the association between prephyromonas gingivitisspecific maternal serum igg and low birth weight. j perio 2001; 72: 1491-1497. 25. madianos p, leift s, murtha a, boggess k, auten r, beck j. maternal periodontitis and prematurity. part 2: maternal infection and fetal exposure. j perio 2001; 6: 175-182. 26. moliterno l, monterio b, figueredo c, fischer r. association between periodontitis and low birth weight. case control study. j clin perio 2005; 32: 886890. 27. moreu g, tellez l, gonzalez m. relationship between periodontal disease and adverse pregnancy outcome. br dent j 2004; 197: 251-258. 28. hitti j, tarezhornoch p, murphy j, aura j, eschenbach d. amniotic fluid infection, cytokines, and adverse out come among infants at 34 weeks gestation or less. obstetrics and gynecology. 2001; 98: 1080-1088. 29. noak b, klingenberg j, weight j hoffmann t. periodontal status and preterm low birth weight: a case -control study. j perio res 2005; 40: 339345. table 1: pl and cal indices among preterm and full term groups. groups pli sig. cali sig. mean ± sd mean ± sd preterm 1.39 0 .27 n.s. 0.17 0.23 n.s. full term 1.38 0.36 0.13 0.29 table 3: salivary interleukin-6 among preterm and full term groups table 2: gi and ppd among preterm and full term groups. groups gi sig. ppd sig. mean ± sd mean ± sd preterm 1.31 0.27 *t = 3.92 1.52 0.24 n.s. full term 1.08 0.18 1.42 0.11 *p < 0.01, d.f = 64 groups salivary il 6 sig. mean ± sd preterm 125.72 21.37 n.s. full term 126.49 37.02 groups salivary il 6 p re te rm pli r = 0.10 p = 0.56 gi r = 0.13 p = 0.46 cali r = 0.11 p = 0.51 ppd r = 0.13 p = 0.46 f ul l t er m pli r = 0.08 p = 0.62 gi r = 0.05 p = 0.78 cali r = 0.15 p = 0.40 ppd r = + 0.23 p = 0.19 table 4: the correlation coefficient between salivary interleukin-6 with pli, cal, gi and ppd among preterm and full term groups. j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 98 immunohistochemical expression of p53 and pcna proteins in oral lichen planus and oral dysplasia lehadh m. al-azzawi, b.d.s., m.sc., ph.d. (1) layla s. alani, b.d.s., m.sc. (2) abstract background: oral lichen planus (olp) is a relatively common chronic inflammatory muco-cutaneous disease classified among the potentially malignant lesions of oral mucosa. the aim of this study is to investigate and compare the expression of p53 and pcna proteins in oral lichen planus and epithelial dysplasia cases. materials and methods:formalin-fixed and paraffinembedded blocks of 21 lichen planusand 21 oral dysplasia cases were referred to immunohistochemical (ihc) analysis for anti p53 and anti pcna monoclonal antibodies. results: the results showed that positive nuclear staining for p53 was found in 11/21 (52.4%) cases of lichen planus and 17/21 (80.9%) cases of dysplasia. positivity for pcna was observed in 18/21(85.7%) of oral lichen planus cases, and19/21(90.5%) of epithelial dysplasia cases. there was a statistically significant difference between the expression of p53 and pcna proteins in oral lichen plauns cases and nonsignificant differences of either protein expression in oral dysplasia cases. no statistically significant difference of p53 and pcna proteins expression between oral lichen planus and epithelial dysplasia cases was found. moreover, there was no significant difference in p53 and pcna expression with respect to the grade of epithelial dysplasia. conclusion: the proportion of cases with positive p53 expression increased from lichen planus to dysplasia. these results may indicate an involvement of p53 in neoplastic transformation as well as in proliferative events pcna, although the absence of p53 staining could be used to predict the outcome of potentially malignant oral mucosal lesions. key words: oral lichen planus, oral dysplasia, p53, pcna. (j bagh coll dentistry 2014; 26(1):98-102). introduction lichen planus is a chronic inflammatory disease of the oral cavity in 1-5% of general population(1) the disease represents as a set of lesions including white involvements (striation, papule, plaque) , erythema , erosions and blisters mainly on the mucosa , gingival structures and tongue (2).oral lichen planus is not a rare condition in human being. this inflammatory disease is generally regarded as a benign pathology; however, transformation towards malignant condition in some cases has forced many physicians to consider l.p as a premalignant entity (3).since the first case was reported in 1910, several studies have suggested that patients with oral lichen planus are at an increased risk of developing cancer (4,5). however; many authors believe that there is insufficient data to prove an association between oral lichen planus and cancer. for these authors, most cases of malignant transformation are the result of errors in the initial diagnosis of the disease (4,6). since the first case reported of squamous cell carcinoma developing farm a mucosal lp, the real odds of such transformation, is a matter of discussion. (1) assistant professor, department of oral diagnosis, collage of dentistry, university of baghdad. (2) lecturer, department of oral diagnosis, collage of dentistry, university of baghdad. thus, several studies have shown different proportions of malignant potential of olp, many authors have accepted the idea that olp is an actual premalignant lesion (7,8). the true potential for malignant transformation of oral lichen planus can be evaluated by analyzing the expression of proteins related to cell proliferation and apoptosis, as alternations in the expression of these proteins are essential for carcinogenesis (9,10). cells that contain p53 genes of the wild type are able to delay cell cycle to allow the repair of damaged dna, or divert the cell into apoptosis. when the protein is mutated or absent, the cells replicate the damaged dna, which will result in more mutation and chromosome rearrangement. mutations in the p53 tumour suppressor gene are the most common molecular defects in human malignancies including oral squamous cell carcinoma (7). the normal p53 gene acts as a tumour suppressor and its wild type acts inhibiting proliferation and oncogene – mediated proliferation and transformation. cells that contain p53 genes of the wild type are able pcna (proliferating cell nuclear antigen) is a nuclear acid protein of 36 kda, which works as an auxiliary protein of delta polymerase, associated to the dna duplication and repair (11). the concentration of pcna is variable during the steps of cell cycle , being higher in late g1 phase , with peaks in g1ls phase, being practically absent in g2 and m phases (12). j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 99 several studies described the application of monoclonal antibodies against pcna, since this is a fine indicator of the biological behaviour of some premalignant and malignant lesions (13). aim of the study is to investigate and compare the expression of pcna and p53 proteins in oral lichen planus and epithelial dysplasia cases. materials and methods twenty-one cases of oral lichen planus and 21 cases of epithelial dysplasia (3 mild, 11 moderate, 7 severe) obtained from the files of the department of oral diagnosis of collage of dentistry – university of baghdad from the period between (2000– 2012) were included in the study.age and gender of patient were not considered because these data are not related to the increase of the risk of malignant transformation of oral lichen planus. three 5μm thick histological sections were cut from the formalin -fixed paraffin-embedded blocks .one section was stained with h&e to verify the histological diagnosis; the remaining two sections were employed for immunohistochemical analysis. the cases of oral lichen planus were selected according to eisenberg’s criteria (14) and world health organization’s criteria for epithelial dysplasia (15). cases of oral lichen planus with doubt of epithelial dysplasia were excluded. immunohistochemical method from each case 5 µm thick sections were cut and mounted on positively charged slides. sections were deparaffinized and rehydrated. for antigen retrieval, the sections for pcna and p53 antigen immunostaining were microwaved treated in citrate buffer (ph 6.0). endogenous peroxidase activity was blocked for 10 minutes in h2o2 and methanol. subsequently, sections were washed with phosphate-buffered saline and incubated at 4ºc with the pcna monoclonal antibody pc10 (dilution 1:50, dako co, glostrup, denmark) and p53 monoclonal antibody do-7(dilution 1:80, dako co, glostrup, denmark. after wash with phosphate-buffered saline, the following step was the incubation with the streptoavidin-biotin complex (dilution 1:100) overnight at 37°c temperature. the reaction products were visualized by immersing the sections in diaminobenzidine (dab) solution. the sections were counterstained with mayer’s haematoxylin for optimal evaluation and cell counting. paraffin – embedded oral squamous cell carcinoma biopsied cases served as positive control. as negative control primary antibodies were replaced and with antibody diluent solution. scoring system after the immunohistochemical reactions, pcna and p53 expression was classified according to the number of positively stained epithelial cell per 1000 cells. a quantitative assessment by was applied by counting cells randomly at the basal and suprabasal epithelium cell layers. the percentage of positive cells was scored according to the method of nakagawa et al. (16) as follows: (+++) = strong staining (more than 50% stained); (++) = moderate staining (25 – 50% stained; (+) = weak staining (5 – 25%); 0 = negative (less than 5% stained). statistical analysis data were analysed by chi – square test. the expressions of both p53 and pcna in epithelial dysplasia according to their grading were analyzed statistically by (anova) test. value of p ≤ 0.05 was considered statistically significant. results it was considered a positive cell if it exhibited a reaction represented by a brownish staining independent of the intensity. the p53 and pcna positive cells showed immunoreactivity restricted to the cellular nuclei of epithelia as shown in figures1(a&b) and 2(a&b). the expression of pcna, in oral lichen planus, was observed in the basal and lower suprabasal layers. while its expression, in dysplastic epithelium, was observed in the suprabasal and lower spinous layers; and the intensity of staining increased along the degree of cellular atypia. the expression of p53, in oral lichen planus, was localized in the basal and lower suprabasal layers and in dysplastic cases was limited to the basal and suprabasal layers. in one case of dysplasia, weak positive immunoreactivity for p53 could be seen in a few isolated cells of the basal layer.positive nuclear staining of p53 was found in 11/ 21 (52.4%) cases of lichen planus and 17/21 (80.9%) cases of dysplasia, while the positivity for pcna was observed in 18/21(85.7%) of the oral lichen planus cases, 19/21(90.5%) of the epithelial dysplasia cases as shown in figures 3 and 4 respectively. chi-squared test showed that the number of positive cases for p53 and pcna was significantly lower in oral lichen planus than in oral epithelial dysplasia (p<0.05). there was a statistically significant difference between the expression of p53 and pcna proteins in oral lichen plauns whereas there was no significant differences of both proteins expression in oral dysplasia .no statistically significant difference of p53 and pcna proteins expression between oral lichen planus and epithelial dysplasia was found (p>0.05). there was no significant difference j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 100 regarding p53 and pcna expression in relation to the grade of epithelial dysplasia as demonstrated in figure 5. discussion it is almost a long time that there is an ongoing debate on the nature of oral lichen planus. despite a number of studies in the literature in this regard, there is not yet a consensus(2 4,6).this is because the higher the cell proliferation rate, the higher the risk of cells suffering mutations during mitosis, which could result in malignant phenotype. p53 tumour suppressor gene which is a frequent target for mutations in a high percentage of oral cancer is regarded as an early event in carcinogenesis (3, 6,9, 17,18). in context, the cases of oral lichen planus with elevated percentage of positive cells for pcna (more than 50% of cell stained) can have a higher malignant transformation risk. in addition, in these cases, the presence of the positive cells for pcna in superficial layer of epithelium suggests possible alterations in cell differentiation mechanisms, step essential to the malignant transformation of epithelium. to depict this heterogeneity van der meijetal(19) found no potential risk of transformation toward scc in their cases with oral lichen planus, while acayetal(7) concluded that oral lichen planus could be regarded as a premalignant condition. according to stoll et al., the loss of p53 function is found in at least half of oral cancer cases. therefore, the similar expression of p53 in oral lichen planus and in epithelial dysplasia can be an important indicator of malignant transformation potential of these lesions (20). immunohistochemical detection of p53 protein does not necessarily indicate p53 gene mutations and malignant transformation, therefore, detection of p53 has been documented in a number of benign conditions, supporting that wild-type protein can be observed in some circumstances where cell damage has occurred. moreover, the do-7 clone reacts with both wild-type and mutants forms of p53, and so there is no exact correspondence between p53 positivity and the presence of p53 mutation (21,22). alteration in the expression of the proteins related to cell proliferation and apoptosis is a strong indicator of the malignant transformation potential of a certain lesion (23).the obtained results suggested that oral lichen planus presents a possibilities of evolution to cancer similar to epithelial dysplasia. therefore, cases of malignant transformation of oral lichen planus are not just consequences of error in their initial diagnosis, but natural evolution of this disease. in the present study, we examined the rate of p53 and pcna expressions in cases with oral lichen planus and epithelial dysplasia. based on the immunohistochemical evaluation, p53 was significantly more prevalent in cases with epithelial dysplasia than in oral lichen planus cases .these findings indicate that there might be a potential tendency for malignancy in oral lichen planus .this result is in agreement with those of several other authors who evaluated the expression of p53 and pcna in addition to other proteins related to cell proliferation and apoptosis in oral lichen planus (24,25). for these authors, the alteration in expression of these proteins were a strong indicator of the potential for malignant transformation of oral lichen planus, as these proteins participate actively in oral carcinogenesis. the results obtained from the present study showed that the number of positive pcna cases in oral lichen planus is lower than in epithelial dysplasia, although it had no significant statistical difference between these two lesions. this fact suggests that, in general, the cell proliferation rate in oral lichen planus is lower than in epithelial dysplasia. therefore, oral lichen planus has a lower possibility to accumulate genetic mutation than the epithelial dysplasia and, consequently, a lower possibility to suffer malignant transformation .this is because the higher the cell proliferation rate, the higher the risk of cells suffering mutation during mitosis, which could result in malignant phenotype. according to lee et al (26), the expression of pcna in oral lichen planus is similar to hyperkeratosis, but superior to normal mucosa and inferior to epithelial dysplasia and oral squamous cell carcinoma, being in accordance to the results obtained in these studies. however, for da silva fonseca and do carmo (27), the higher cell proliferation rate in oral lichen planus than in hyperkeratosis and normal mucosa makes it more susceptible to the action of carcinogens. in conclusion, the proportion of cases with positive p53 expression increased from lichen planus to dysplasia. these results may indicate an involvement of p53 in neoplastic transformation as 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(ivsl). 24. kuropkat c, venkatesan tk, caldarelli dd, panje wr, hutchinson j, preisler hd, coon jc, werner ja. abnormalities of molecular regulators of proliferation and apoptosis in carcinoma of oral cavity and oropharynx. larynx 2002; 29: 165-74. 25. gonzalez-moles ma, basconesilundain c, gil montoya ja, ruizavila i, delgadorodriguez m, basconesmartinez a. cell cycle regulating mechanisms in oral lichen planus: molecular bases in epithelium. arch oral biol 2006; 51:1093-103. (ivsl). 26. lee jj, kuo my, cheng sj, chiang cp, jeng jh, chang hh. higher expression of p53 and proliferating cell nuclear antigen (pcna) in atrophic oral lichen planus and patients with areca quid chewing .oral surg oral med oral pathol oral radiol endod 2005; 99: 471-8. 27. da silva fonseca lm, do carmo ma. identification of the ag-nors, pcna and ck16 proteins in oral lichen planus lesions. oral dis 2001; 7: 377-8. http://www.ncbi.nlm.nih.gov/pubmed?term=kerdpon%20d%5bauthor%5d&cauthor=true&cauthor_uid=9467348 http://www.ncbi.nlm.nih.gov/pubmed?term=rich%20am%5bauthor%5d&cauthor=true&cauthor_uid=9467348 http://www.ncbi.nlm.nih.gov/pubmed?term=reade%20pc%5bauthor%5d&cauthor=true&cauthor_uid=9467348 http://www.ncbi.nlm.nih.gov/pubmed/9467348 j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 102 a. b. figure 1: oral lichen planus (a: p53 x200; b: pcna x200). a. b. figure 2: oral dysplasia (a: p53 x200; b: pcna x200). figure 3: expression of p53 and pcna in oral lichen planus. figure 4: expression of p53 and pcna in oral dysplasia. figure 5: expression of p53 and pcna in relation to the grading of oral dysplasia. j bagh college dentistry vol. 29(1), march 2017 dental caries pedodontics, orthodontics and preventive dentistry 188 dental caries experience and salivary elements among a group of young adults in relation to age and gender samara faris abdel aziz, b.d.s. (1) wesal ali al-obaidi, b.d.s., m.sc. (2) abstract background: dental caries is a most common social and intractable infectious disease in human. saliva is critical for preserving and maintaining oral health and salivary elements had many effects on caries experience. aim of study: this study was conducted to assess dental caries severity by age and gender and their relation to salivary zinc and copper among a group of adults aged (19-22) years. materials and methods: after examination eighty persons aged 19-22 years of both gender. caries severity was documented according to dmfs index. stimulated salivary samples were collected and chemically analyzed under standardized condition to detect salivary elements zinc and copper. concentrations of zinc and copper were measured by using atomic absorption spectrophotometry. results: the finding revealed that the total males had higher mean value of dmfs and ds fraction than that of the total females with statistically non-significant differences at p> 0.05 regarding of dmfs, while significant difference was found regarding ds fraction. frist age group (19-20) had a lower mean value of dmfs than that of the second age group (21-22), while it had a higher mean value of ds fraction with statistically non-significant differences. there were statistically non-significant differences at p> 0.05 between males and females regarding salivary zinc and copper concentrations.non-significant positive weak correlation between dmfs index and salivary zinc and copper. conclusion: saliva is the one of important factors in prevention of dental caries. therefore, chemical changes in salivary composition play an important role in development and progression of caries. key words: dental caries, zinc, copper, young adults person. (j bagh coll dentistry 2017; 29(1):188-192) introduction dental caries is the most common chronic disease among oral disease. all people are affecting by dental caries irrespective of their socioeconomic classes, gender, race and age. it is also greatly affected by additional factors such as saliva and oral hygiene (1,2). zinc is present in saliva and it is ubiquitous in the body (3) and the teeth (4). zinc (zn) was considered to be doubtful element that inhibits caries development (5). zinc, an anti-inflammatory agent and intracellular signaling molecule, is instrumental in immune response and serves important functions in the body with its antioxidant properties. its dynamic for stimulating growth, neurological and physical development in infants, children and teenagers (6). copper ion (cu) has been recorded to have many effects on general health and in addition to antibacterial effect of copper both in vitro (7) and in vivo (8). there are many studies showed that there are nonsignificant differences between the level of salivary copper and high significant variation in concentration of salivary zinc among children with caries experience and caries free children regardless to age and gender (9, 10, 11). for all the above, this study was conducted among a group (1) m.sc. student, department of preventive dentistry. college of dentistry. university of baghdad (2) professor, department of preventive dentistry, college of dentistry, university of baghdad. of adults to assess zinc and copper ions in relation to caries experience. materials and methods eighty subjects (30 males and 50 females) were randomly selected in this study (cross sectional study), they were between the age of 1922 years of both gender. this study was carried out during the period between 21 december 2014 and 3 march 2015 in baghdad. collection of samples was at al-jameaa heath center and at collage of dentistry/ baghdad university, all laboratory works were done in poisoning consultation center, gazi al-hariry hospital. collection of saliva is done at morning 10-12 a.m. collection of stimulated salivary samples was performed under standard condition following the instructions cited by tenovuo and lagerlof (12). each subject gets a tube and asked to collect 5 ml saliva in the tube by spitting. after collection of saliva, samples were centrifuged at 3000 rpm for 5 minutes, the clear supernatant were separated and stored frozen at20 c in plastic polyethylene tubes until time of biochemical analysis. caries-experience was diagnosed and recorded according to decayed, missing and filled (dmfs) index following the criteria described by who (13). the examination starts from the upper right second molar from one tooth or space to adjacent tooth or tooth space reach upper left second molar then to lower left ending with the lower right second molar. biochemical analysis for essential elements zinc and copper j bagh college dentistry vol. 29(1), march 2017 dental caries pedodontics, orthodontics and preventive dentistry 189 (µg/dl) was achieved by using buck scientific atomic absorption spectrophotometer. results although total males had higher mean value of dmfs than that of the total females (9.36±1.10, 8.08±1.47 respectively), but statistically nonsignificant differences at p > 0.05 was found between them. total first age group (19-20) had a lower mean value of dmfs than that of the total second age group (21-22) with statistically nonsignificant difference between two age groups (df=78, t-test=0.96, p=0.34) for total two age group (table 1). table (2) demonstrates the mean values and standard errors of ds fraction of dmfs index in males and females for both age groups. total males showed higher mean values of ds than that of the total females (5.17±0.85, 3.58 ±0.72 respectively) with statistically significant differences at p < 0.05.table (3) shows the mean values and standard errors of salivary zinc concentration measured (µg/dl) in males and females for both age groups. total males demonstrated the same mean value of salivary zinc concentration as in total females (3.47±0.20, 3.39±0.14 respectively) with statistically non-significant differences at p > 0.05.the first age group (19-20) had the same mean value of salivary zinc concentration with the second age group (21-22) with statistically non significant difference (df=78, t-test=1.84, p=0.06). also there were no significant differences in between males and females in the sub age groups regarding salivary zinc concentration at p > 0.05. total males reported the same mean value of salivary copper concentration as in the total females (5.24±0.10, 5.39±0.13 respectively) with statistically non-significant differences at p > 0.05. statistically, non-significant difference was found between two age groups regarding salivary copper concentration (df=78, t-test=0.25, p=0.80) (table 4). a non-significant positive weak correlations were found between dental caries and salivary zinc and copper (r=0.193, p=0.086; r=0.085 p=0.451 respectively) table 1: caries experience dmfs by age and gender age gender no. mean ±se df t-test p-value 19-20 male 12 6.83 1.46 27 0.17 0.87 female 17 7.58 3.51 total 29 7.27 2.12 21-22 male 18 11.05 1.45 49 1.27 0.21 female 33 8.33 1.36 total 51 9.29 1.03 total male 30 9.36 1.10 78 0.62 0.54 female 50 8.08 1.47 total 80 8.56 1.02 table 2: caries experience ds component of dmfs by age and gender age gender no. mean ±se df t-test p-value 19-20 male 12 5.17 1.29 27 0.42 0.68 female 17 4.06 1.99 total 29 4.52 1.27 21-22 male 18 5.17 1.16 49 2.34* 0.02 female 33 2.82 0.38 total 51 3.5 0.52 total male 30 5.17 0.85 78 2.04* 0.04 female 50 3.58 0.72 total 80 4.55 0.57 *significant j bagh college dentistry vol. 29(1), march 2017 dental caries pedodontics, orthodontics and preventive dentistry 190 table 3: salivary zinc concentration (µg/dl) by age and gender age gender no. *mean ±se df t-test p-value 19-20 male 12 4.01 0.38 27 1.18 0.25 female 17 3.50 0.23 total 29 3.71 0.21 21-22 male 18 3.12 0.20 49 0.75 0.45 female 33 3.34 0.18 total 51 3.25 0.13 total male 30 3.47 0.20 78 0.32 0.74 female 50 3.39 0.14 total 80 3.42 0.11 table 4: salivary copper concentration (µg/dl) by age and gender age gender no. *mean ±se df t-test p-value 19-20 male 12 5.33 0.17 27 0.22 0.83 female 17 5.38 0.11 total 29 5.35 0.09 21-22 male 18 5.18 0.14 49 0.98 0.33 female 33 5.39 0.13 total 51 5.31 0.10 total male 30 5.24 0.10 78 0.95 0.34 female 50 5.38 0.09 total 80 5.33 0.07 discussion in the present study, eighty young adult persons aged 19-22 years were randomly selected (males 30 and females 50). dental caries begins with microbiological shifts and is influenced by salivary composition and flow rate, dietary sugars consumption, fluoride exposure and preventive measurements (1). total males had a slightly higher mean values of dmfs and ds than that of the total females, this could be attributed to negligible oral cleanliness by males so that the level of oral hygiene worse than females this result in agreement with another study (14, 15). the result of this study is in disagreement with ahmadi-motamayel study (16) which may be attributed to the earlier eruption of teeth among females, which causes longer exposure to cariogenic environment in the mouth (17). although the dmfs in this current study was higher among total second age group (21-22) years, it was reported that ds was higher among total first age group (19-20) years. this result is controversy with kaur study (18). this finding may be attributed to management of dental caries was increasing by age and directed toward either missed or filled teeth. saliva was used as diagnostic aids because salivary constituents exhibit a well-documented role in health and disease, its emerging as a viable alternative to blood sampling (19). decision was made to collect stimulated saliva to obtain more saliva and it was reported that the stimulated saliva samples were superior because lower sample variance than with un-stimulated saliva (20). findings showed nonsignificant differences in copper level in saliva between the age groups which similar to other studies (21, 22, 23). regarding salivary zn level results also reported non-significant differences in this element among different age groups which could be attributed to small range of age group in present study, which is in agreement with borella et al study (21) who reported that zn level is not affected by age, while is inconsistent with hussein et al study (22) which revealed significant differences in zn level among different age groups (8-12) years without any explanation and this point of controversy need further investigation. the current study showed a positive correlation between salivary zinc level and dmfs and ds. these findings differ with that of a study in young adults (21) and other studies in children (10, 23) who reported a negative correlation between zn level and dental caries which may be attributed to high level of zinc leads to greater mineralization and accumulation of zinc quantities on surface enamel that becomes more caries resistance (24) and similar with other studies (22, 25). this finding, in current study, might be attributed to that the properties and behavior of zn element in saliva that are similar to those of cu, which could dissolve from the tooth into saliva upon j bagh college dentistry vol. 29(1), march 2017 dental caries pedodontics, orthodontics and preventive dentistry 191 demineralization that occurs with caries. a positive correlation was also reported between salivary copper and dmfs and ds which is similar to findings reported from some studies (22, 25) and disagrees with other studies (11, 26) who reported an increase in cu concentration with decrease caries severity. this current study suggested that possibility of tiny cu amounts present in the tooth could dissolve into saliva by demineralization, thereby resulted in the increase of cu level in mixed saliva. findings in current study indicate a positive correlation between caries and salivary cu and zn suggesting the possibility of their effect in the formation of tooth decay. the variation in finding of present study from previous studies could be attributed to the method of biochemical analysis, age of sample and method of saliva collection. references 1. fejerskov o, kidd eam. dental caries, the disease and its clinical management. london, blackwell munksgaard, 2003. 2. preethi bp, reshma d, anand p. evaluation of flow rate, ph, buffering capacity , calcium, total protein and total antioxidant capacity level of saliva in caries free and caries active children: an vivo study. indian j.clin. biochem 2010; 25 (4):425-428. 3. kim yj, kim yk, kho h-s. effects of smoking on trace metals in saliva. oral disease 2010; 16: 823– 830. 4. thylstrup a, fejerskov o. caries chemistry and fluoride – mechanism of action. textbook of clinical cariology. 2nd ed. copenhagen: munksgaard 1999; 231–258. 5. shashikiram n, subba v,hiremath m .estamation of trace element in sound and carious enamel of primary and permanent teeth by atomic absorption spectrophotometer an in vitro study 2007;4:157-162. 6. prasad as. zinc: role in immunity, oxidative stress and chronic infl ammation. curr opin clin nutr metab care 2009; 12:646–52. 7. orstavik d. antibacterial properties of and element release from some dental amalgams acta odontology of scandanavia 1985; 43(4) :231-239. 8. foley j , blackwell. a in vivo cariostatic effect of black copper cement on carious dentine caries research 2003; 37(4): 254260. 9. al-obeidi a.s. nursing caries in relation to salivary calcium, phosphorus, zinc and copper ions concentration and dietary habits analysis in selected sample of pre-school children . master thesis, college of dentistry, university of baghdad, 2005 10. zahir s, sarkar s. study of trace elements in mixed saliva of caries free and caries active children. j indian soc pedod prev dent 2006; 24: 27-29. 11. kadum n, salih b. selected salivary constituents, physical properties, nutritional status in relation to dental caries among (4-5) years old children. j bagh college dentistry 2014; 26 (2). 12. tenovuo j, lagerlöf f. saliva. in: thylstrup a, fejerskov o.eds textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1994; 17-43. 13. who. oral health surveys basic methods. 3rd ed. world health organization, geneva, switzerland, 1987. 14. hamissi j, gh ramezani gh, ghodousi a. prevelance of dental caries among high school attendees in qazvin, iran. journal of indian society of pedodontics and preventive dentistry 2008; 26(6):53-55. 15. al-hadithi h. caries experience among children 6-12 years with betathalassemia major syndrome in comparison to healthy control in baghdad-iraq. j bagh college dentistry 2011; 23 (2): 128-132. 16. ahmadi-motamayel f, goodarzi m, hendi s, abdolsamadi, rafieian n. evaluation of salivary flow rate, ph, buffering capacity, calcium and total protein levels in caries free and caries active adolescence. j dentistry and oral hygiene 2013; 5(4):35-39. 17. wedl js, shchmelzle r, friedrich re. the eruption times of permanent teeth in boys and girls in storman district, schelwig –holstein germany. anthropol anz 2005; 63(2):189-97. 18. kaur r, kataria h, kumar s, kaur g. caries experience among females aged 16–21 in punjab, india and its relationship with lifestyle and salivary hsp70 levels. eur j dent 2010 jul; 4(3): 308–313. 19. bald e, glowacki r. analysis of saliva for glutathione and metabolically related thiols by liquid chromatography with ultraviolet detection. amino acids 2005; 28: 431–433. 20. gu f, lux r, anderson m, del aguila m, wolinsky l, hum w, shi w. analysis of streptococcus mutans in saliva with speciesspecific monoclonal antibodies. hybridoma and hybridomics 2002; 21: 225-233. 21. borella p, fantuzzi g, aggazzotti g. trace elements in saliva and dental caries in young adults. sci total environ 1994; 153(3):219-24. 22. hussein a, ghasheer h, ramli n, schroth r, abuhassan m. salivart trace elements in relation to dental caries in a group of multiethnic in shah alam, malaysia. eur j paediatr dent 2013 jun; 14(2):113-8. 23. alsaadi a.a. oral health condition and salivary constituents (zinc, copper, calcium, iron and total protein) among the selected overweight primary school children. master thesis, college of dentistry, university of baghdad, 2008. 24. chandra s, chandra s, chandra. textbook of operative dentistry. 1st ed. jaypee brother of medical puplisher (p) lft new delhi india, 2007. 25. hedge m, hedge a, ashok a, shetty s. biochemical indicator of dental caries in saliva: an avivo study. caries res 2014; 48(2):170-3. 26. shetty p, kumara s. serum copper level in dental caries patients: a case control study. asian j med cli sci sep-dec 2012; 1(3):142-143. http://www.comparinggenie.com/code/r.php?r=yahoo%7csyndrome%2520in%2520comparison%2520to&t=18&did=18&uid=0&type=bl&subid=bdraw&rkw=syndrome+in+comparison+to&rurl=http%3a%2f%2frepository.uobaghdad.edu.iq%2farticleshow.aspx%3fid%3d870&domain=uobaghdad.edu.iq&lnktype=10&v=0.103&browser=chrome_47&country=iq&_=1450864886132 http://www.comparinggenie.com/code/r.php?r=yahoo%7csyndrome%2520in%2520comparison%2520to&t=18&did=18&uid=0&type=bl&subid=bdraw&rkw=syndrome+in+comparison+to&rurl=http%3a%2f%2frepository.uobaghdad.edu.iq%2farticleshow.aspx%3fid%3d870&domain=uobaghdad.edu.iq&lnktype=10&v=0.103&browser=chrome_47&country=iq&_=1450864886132 j bagh college dentistry vol. 29(1), march 2017 dental caries pedodontics, orthodontics and preventive dentistry 192 الخالصة مة كبرى تسوس األسنان هو مرض اجتماعي معد ويعتبر األكثر شيوعا في اإلنسان. نظرا لتأثيره الكبير واالنتشار الواسع، فهو يعتبر مشكلة صحية عا الملخص: على الصعيد العالمي. وكانت للعناصر اللعابية تأثيرات كثيرة على تجربة التسوس. ( حسب العمر والجنس وعالقتها بالعناصراللعابية الخارصين والنحاس بين dmfsتجربة تسوس األسنان )وقد أجريت هذه الدراسة لتقييم الهدف من الدراسة: ( سنة.22-91مجموعة من البالغين الذين تتراوح أعمارهم بين ) ع عينات اللعاب المحفز وتحليلها . تم جمdmfsعاما من كال الجنسين قد تم قياس تجربة التسوس وفقا لمؤشر 22-91بعد فحص ثمانين شخصا المواد والطرق: الذري. كيميائيا تحت ظروف موحدة للكشف عن العناصر اللعابية الزنك والنحاس. تم قياس تراكيز الزنك والنحاس باستخدام القياس الطيفي لالمتصاص من قيمة متوسط التسوس لدى مجموع اإلناث االجمالي مع عدم وجود فرق ى( لدى مجموع الذكور االجمالي أعلdsو dmfsقيمة متوسط التسوس ) النتائج: ( االولى متوسط 22-91(. كان لدى الفئة العمرية )ds) فيما يتعلق بالتسوس ( في حين وجد فرق احصائي معنوي dmfsاحصائي معنوي فيما يتعلق بالتسوس) ( مع عدم وجود فرق احصائي 22-29( اعلى من الفئة العمرية الثانية )ds)نه كان لديها متوسط التسوس (، في حين أ22-29أقل من الفئة العمرية الثانية )التسوس معنوي. نوي في مؤشر وكانت مستويات العناصر االلعابية )الزنك والنحاس( أعلى بين المجموعة النشطة التسوس من المجموعة الخالية من التسوس واليوجد فرق مع كان لدى مجموع الذكور الكلي تقريبا نفس قيمة متوسط تراكيز الخارصين والنحاس اللعابية كما في مجموع االناث مع وجود اختالفات .عاتالتسوس بين المجمو والعناصر اللعابية الخارصين والنحاس. dmfsاحصائية غير هامة.هناك ارتباط ضعيف ايجابي غير كبير بين مؤشر التسوس وتقدم التسوس.اللعاب هو أحد العوامل الهامة في الوقاية من تسوس األسنان. لذلك فان التغيرات الكيميائية في تكوين اللعاب تلعب دورا هاما في تطور االستنتاج: كلمات مفاتحية: تسوس األسنان ,الزنك ,النحاس ,الشباب البالغين. basima final.doc j bagh college dentistry vol. 26(3), september 2014 correlation between oral and maxillofacial surgery and periodontics 84 correlation between crevicular c-reactive protein level with its serum level in chronic periodontitis patients basima gh. ali, b.d.s., m.sc. (1) abstract background: the main purpose of this study is to find if there is any correlation between the level of c-reactive protein (crp) in gingival crevicular fluid with its serum level in chronic periodontitis patients and to explore the differences between them according to the probing depth. materials and methods: forty seven male subjects enrolled in this study. thirty males with chronic periodontitis considered as study group whom further subdivided according to probing depth into subgroup 1 with pocket depth ≤6mm, subgroup 2 with pocket depth >6mm. the other 17 subjects considered as controls. for all subjects, clinical examination where done for periodontal parameters plaque index (pli), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal). the gingival crevicular fluid (gcf) were collected using filter paper size 30 from gingival sulcus of the controls and from (138) pocket site (75 sites > 6mm. and 63 ≤ 6mm.). the weight of the gcf was measured by reading the difference in the weight of filter paper before and after absorption of gcf. crevicular level of crp was measured calorimetrically. the serum level crp was measured using latex test. results: highly significant difference in the weight of gcf, crevicular and serum level of crp between chronic periodontitis and control groups. subgroup 2 got higher scores of weight of gcf and positive record of crevicular and serum crp compared with subgroup 1 with a non-significant difference. a highly significant difference in the number of sites with positive crevicular and serum crp compared to the negative number between chronic periodontitis and control groups also between subgroup1 and subgroup 2. weight of gcf gets a negative significant correlation with gi at control group and subgroup2. serum level of crp exhibits a negative significant correlation with pli for chronic periodontitis and control group and positive significant correlation for gi at subgroup 1. the crevicular crp get significant negative correlation with gi of subgroup 1. conclusions: crevicular fluid is very good marker for the degree of inflammation of the periodontal pocket. the crevicular level of crp may be considered as a good tool for estimating the systemic effect and predictor for the effect of periodontitis on the general health and the correlation of crevicular with serum crp aid to high light this effect. keywords: crevicular c reactive protein, chronic periodontitis, gingival fluid. (j bagh coll dentistry 2014; 26(3):84-88). الخالصة ع زمن بالمقارنة مالھدف الرئیسي من ھذه الدراسة ھو معرفة تركیز البروتین االرتكاسي في السائل اللثوي ومقارنتھ مع تركیزه في مصل دم مرضى النسغاغ الم توصلت . تلك التراكیز ومؤشرات ماحول االسنان السریریة في مجموعة الدراسة والمجموعة الضابطةالمجموعة الضابطة ایضا تحاول الدراسة ایجاد عالقات بین االصابة بمرض النساغ المزمن الدراسة الى انھ ھناك فرق واضح في التراكیز بین كال المجموعتین وكذلك فان مستوى البروتین االرتكاسي یختلف باختالف شدة وخلصت الدراسة الى ان مرض النساغ المزمن مع مؤشراتھ المناعیة قد یعكس صورة تاثیر ھذا المرض على الصحة العامة introduction periodontitis is a group of inflammatory diseases of teeth supporting tissues. the spreading of the inflammatory process from the gingival deep into periodontal tissues may lead to the destruction of the periodontal ligament and considerable bone loss in the alveolar process. a large part of therapy for periodontitis is eliminating inflammation. this is not only to preserve periodontal tissues but also to eliminate an oral source of inflammation contributing to over all systemic health (1). recent efforts have focus on periodontitis as a potential trigger for systemic inflammation (2). serum c reactive proteins (scrp) level is often elevated in subjects with periodontitis compared to non – periodontitis subject (3). this acute phase protein is produced in the liver in response to inflammatory or infections stimuli and act as inflammatory markers c-reactive protein induces monocytes and or macro phages to produce tissue (1)assistant professor. department of periodontics, college of dentistry, university of baghdad. factors which stimulate the coagulation pathway and increases blood coagulability. crp also stimulates the complement cascade, further exacerbating inflammation (1,4). crp level is positively influenced by conventional periodontal treatment and may significantly improve the systemic condition (5). gingival crevicular fluid (gcf) is an exudates of varying composition seeps into gingival crevice, or periodontal pockets around teeth, it is a complex mixture of serum, inflammatory cells, connective tissue, epithelium, and microbial flora inhabiting the gingival margin or the sulcus or pocket. these substances possess a great potential for serving as indicators of periodontal disease and healing after therapy (6). the present study aimed to detect the weight of gcf and assess the level of crp in gcf and serum and compare between them in chronic periodontitis patients compared to controls. also aimed to determine if the crevicular crp is the result of its local production within the periodontal pocket by comparing its level with different pocket depths and compared to its serum j bagh college dentistry vol. 26(3), september 2014 correlation between oral and maxillofacial surgery and periodontics 85 level and finally to correlate the immunological parameters (weight of gcf, crevicular and serum crp) with clinical periodontal parameters pli, gi, bop, ppd, cal for all studied groups and subgroups. materials and methods forty seven male subjects attending the department of periodontics at college of dentistry/ university of baghdad were invited to participate in the study following written and informed consent. the subjects were divided to study and control groups. the study group composed of 30 subjects with an age ranged between 35-50 years with chronic periodontitis (cpg) according to the international classification system for periodontal disease (7). the total numbers of the examined sites equal to 138 pocket sites. the study group further subdivided according to their pocket depth into 2 subgroups. subgroup 1; included 16 males with 63 sites of ppd ≤ 6 mm., subgroup 2; included 14 males with 75 sites of ppd > 6mm. the control group (cg) consisted of 17 subjects with clinically healthy periodontium with an age ranged between 35-45 years. all subjects were non-smoker, and systemically healthy according to their medical history. all didn’t receive any periodontal treatment or take local or systemic antibiotics or anti-inflammatory medications within the previous three months. periodontal assessments include the following indices: 1. plaque index system pli according to silness and loe 1964 (8) 2. gingival index gi by loe 1967 (9) 3. bleeding on probing bop expressed as percentage of site with bop (10) which are either positive (+ve) or negative (-ve). 4. probing pocket depth ppd measured from the gingival margin to the most apical penetration of periodontal probe (7). the mean ppd of each patient of the study group determine his location in either subgroup 1 or 2 5. clinical attachment level (cal): measured from the c.e.j. to the deepest point of inserted probe tip. all measurements were done for all the present teeth except 3rd molar (7) by williams' periodontal probe collection of crevicular fluid the collection of gcf was done on a day other than the day of clinical examination. after a thorough supra-gingival scaling, the teeth were carefully dried before the collection of the fluid using pre-weighted filter papers size 30 which were gently inserted into the selected pocket for the study group and to the depth of gingival sulcus in the control group. the paper left for 30 second (11), and re-weighted using a chemical balance after their removal. each paper placed in tube containing 0.3 ml. normal saline then transferred and stored at -20º c. at the day of analysis the sample were centrifuged at 10.000 rpm /20min. the supernatant was used for assessment of crp calorimetrically. if the concentration of crevicular crp (c.crp) ≥ 6pg/ml. this is considered as a + ve finding. serum collection identification of the concentration of serum crp (s.crp) was done using latex test. 2 ml. venous blood was withdrawn from each subject .the blood then centrifuged at 3000 r.p.m. for 5min. the supernatant was harvested for further analysis by agglutination test for detection of serum crp. if the agglutination took place within the first seconds, the positive reading was considered strong + ve. the normal concentration of serum crp ranged between 2-12 mg/l. statistical analysis the mean values and standard deviations of the measured parameters were obtained and groups' differences were assessed using t-test. the correlation between the crevicular and serum level of crp with clinical parameters was examined by pearson's correlation analysis. chi square test was used to assess the differences in the numbers of the +ve records with the –ve records. the probability values greater than 0.05 were considered non-significant results a total of 138 periodontal pocket sites were included in this study from chronic periodontitis group. pocket depth ≤ 6mm were equal to 63 sites while pockets greater than 6 mm were 75 pockets. table 1 represented the descriptive data of the cpg, cg and subgroup 1&2 for pli, gi, ppd, cal and bop. table 2 represented the descriptive statistics of the immunological parameters including weight of gcf, crevicular and serum mean number of positive crp for cpg, cg and for both subgroups. it appears that the weight of gcf increase in cp group (0.6±0.166) over the cg (0.14±0.05). also the mean number of positive results/subject of s. crp is higher in cpg (0.72±0.45) than cg (0.17±0.39). the c. crp j bagh college dentistry vol. 26(3), september 2014 correlation between oral and maxillofacial surgery and periodontics 86 equals to (0.55±0.5) among cp group while no one in the cg revealed a positive crevicular crp. a highly significant difference in the level of s. crp, c. crp and weight of gcf between cpg and cg was presented in table 3. when comparing the difference in the weight of gcf and the positive results of crevicular and serum crp between the two subgroups, it appears that all the immunological parameters carry highest scores within subgroup 2 compared to those in subgroup1 with a non-significant difference. a significant difference appear in the weight of gcf between subgroup 1&2 (table 2). table 1: descriptive statistics of clinical parameters for all studied groups (mean± sd) parameter cpg cg subgroup 1 subgroup 2 pli 1.272±0.422 0.411±0.126 1.3±0.408 1.23±0.45 gi 1.179±0.225 0.38±0.09 1.18±206 1.169±0.256 ppd 5.241±1.09 4.37±0.5 6.307±0.480 cal 6.03±1.592 5.68±1.77 6.46±1.26 bop 0.552±0.506 0 0.5±0.516 0.615±0.506 table 2: the descriptive statistics of the immunological parameters for the studied groups (mean ±sd) parameter cpg cg subgroup 1 subgroup 2 weight/gcf 0.6±0.16 0.14±0.5 0.58±0.17 0.62±0.15 c.crp 0.55±0.5 0 0.44±0.51 0.69±0.48 s.crp 0.72±0.45 0.17±0.39 0.68±0.47 0.76±0.43 table 3: the significant differences in the mean number of positive results of crp/subjects and weight of gcf (inter groups and subgroups comparison) immunological parameters cpg/cg subgroup 1/subgroup2 weight gcf t-test = 2.09 t-test = 2.05 p value = 0.001 hs p value = 0.507 ns c.crp t-test = 2.01 t-test = 2.06 p value = 0.000 hs p value = 0.18 ns s.crp t-test = 2.02 t-test = 2.05 p value = 0.0001 hs p value = 0.63 ns correlation of clinical with the immunological results among all studied groups correlation of the clinical parameters in all studied groups and subgroups with the immunological findings are shown in table 4. for cpg, the pli and gi showed negative correlation with the crevicular and serum levels of crp while they showed a positive correlation with the weight of gcf. bop showed a nonsignificant direct correlation with the crevicular and serum crp levels and the weight of gcf. a non-significant negative correlation of the cal appears with weight of gcf and the serum crp and non significant positive correlation with crevicular crp. while ppd correlated nonsignificantly with all immunological parameters within cpg in positive direction. for the subgroup i, pli showed a non significant positive correlation with the weight of gcf and s.crp, and a significant negative correlation with crevicular crp. gi presented a significant positive correlation with crevicular crp and significant negative with serum crp, and it correlated non-significantly with the weight of cgf. bop correlated positively with weight of gcf, serum and crevicular crp. cal correlated non-significantly with all immunological parameters. the probing depth got a non-significant positive correlation with weight of gcf, c.crp and s.crp. for subgroup 2, pli and gi showed a nonsignificant correlation with the crevicular and serum crp. pli correlated significantly with the weight of gcf. bop showed positive non-significant correlation with weight of gcf and c. crp while it correlated non-significantly with s.crp. the cal showed non-significant negative correlation with the weight of gcf but the correlation was non-significant positive with the crevicular and serum crp. the probing pocket depth has a weak non-significant positive correlation with the level of crp in crevicular j bagh college dentistry vol. 26(3), september 2014 correlation between oral and maxillofacial surgery and periodontics 87 fluid and serum while the correlation was negative with the weight of gcf for cg, the weight of gcf correlated nonsignificantly with pli and significantly with gi. s.crp got a significant negative correlation with pli and non-significant positive with gi. the correlations between the immunological parameters within the two subgroups are shown in table 5. the correlation between crevicular crp and serum crp level within subgroup 1 and 2 appears to be weak non-significant positive correlation. on the other hand, the weight of gcf correlated non-significantly with crevicular crp in both subgroups. table 6 represented the significance difference in the numbers of the positive and negative scores of crp for subgroup 1 and 2 using chi square test. the data showed that there is a non significant difference between the number of subjects who develop a positive finding of either crevicular or serum crp compared to those with negative findings. table 4: pearson correlation between the clinical and immunological parameters for all studied groups weight gcf s. crp c. crp cp cg subg 1 subg 2 cp cg subg 1 subg 2 cp cg subg 1 subg 2 r/sig. r/sig. r/sig. pli 0.62 s 0.2 ns 0.65 ns 0.64 ns -0.04 s -0.04 s 0.14 ns -0.25 ns -0.23 ns -0.22 s -0.23 ns gi 0.22 ns -0.007 s 0.50 ns -0.02 s -0.16 s 0.19 ns 0.03 s -0.37 ns -012 s -0.01 s -0.22 ns bop 0.08 ns 0.11 ns 0.016 ns 0.06 ns 0.13 ns -0.06 ns 0.60 ns 0.63 ns 0.50 ns cal -0.20 ns -0.21 ns -0.34 ns -0.13 ns -0.44 ns 0.36 ns 0.15 ns -0.06 ns 0.40 ns ppd 0.06 ns 0.16 ns -0.54 ns 0.21 ns 0.24 ns 0.37 ns 0.40 ns 0.36 ns 0.04 ns table 5: correlation of immunological parameters with each other table 6: comparison of +ve/-ve numbers for the subgroup1 and 2 parameters subgroup 1 n=16 subgroup 2 n=14 x2 df sig. +/ % -/ % +/% -/% c. crp 7/43.0 9/64 9/64.2 5/35.7 1.88 1 0.17 (ns) s. crp 11/68.7 5/31.2 10/71.4 4/28.5 0.4 1 0.62 (ns) discussion the crevicular fluid provides a non-invasive access method to the periodontium. the marker in gcf is considered a good method in the determination of a person's risk for periodontal disease (12). the increase in the weight of gcf in the present study among the cp patients compared to controls also represented in other studies who studied the volume of gcf which found to be associated with diseases state compare to healthy (13). on the other hands its clearly obvious that gcf increase in the severity of inflammation in term of pocket depth and this in agreement with some studies (13,14). c-reactive protein is a trace protein in the circulation of healthy subject with a median concentration of 1mg/l. this concentration can be increased 100 fold or more in response to injury, infection or inflammation (15,16). in patients with periodontitis, the periodontal pathogens presence in periodontal pocket/ sulcus can elicit some source of bacterial products that could lead to activation of liver through systemic antibody response and so increase in crp production, that's why an increase in s.crp was seen in cp patients compared to controls and the level of s.crp increased with the increase in the pocket depth compared to controls (17). a small elevation in crp elicited by periodontal disease might be considered potential parameters subgroup1(r/sig.) subgroup 2(r/sig.) weight/c.crp 0.09/ns -0.34/ns s.crp/c.crp 0.32/ns 0.43/ns j bagh college dentistry vol. 26(3), september 2014 correlation between oral and maxillofacial surgery and periodontics 88 risk factor for systemic disease as cardiac disease. the elevated level of crp in gcf of cp patients compared to control who registered no crp in their gcf corresponded with findings of macovei et al. (18). as no one of the subjects in control group registered a positive reading of c.crp, this means that the production of crp in gcf is in response to local inflammation within the periodontium in addition to the systemic effect. on the other hand, the positive reading of s.crp with c.crp within cp group reflects the effect of undiagnosed systemic condition that could aid in elevation level of crp in gcf i.e. effect of periodontitis to elicit systemic inflammation (18,19). the difference in the correlation results of clinical periodontal parameters with the immunological parameters may be related to methodology and number of examined subjects in this study. also the non-significant correlation of crevicular level of crp with its serum level in accordance to probing depth gives an idea about the presence of such correlation which needs further analysis using larger sample size and more sensitive method of analysis. references 1. carenza fa. clinical periodontology. 9th ed. philadelphia: saunders company; 2009. 2. young a, jonski g, rolla g, waler sm. effect of metal salt on the oral production of volatile suffers containing compounds (vsc). j clinic periodontol 2001; 28: 776-81. 3. craig rg, yip jk, so mk, boylan rj, socransky ss, haffajee ad. relationship of destructive periodontal disease to the acute: phase response. j periodontol 2003; 74: 1007-16. 4. thakare ks, deo v, bhongade ml. evaluation of the c-reactive protein serum levels in periodontitis patients with or without atherosclerosis. indian j dental res 2010; 21: 326-9. 5. d'aiuto f, parkar m, andreou g, suvan j, brett pm, ready d, tonetti ms. periodontitis and systemic inflammation: control of the local infection is associated with a reduction in serum inflammation markers. j dental res 2004; 83: 156-60. 6. fitzsimmons tr, sanders ae, bartold pm, slade gs. local and systemic biomarkers in gingival crevicular fluid increase odds of periodontitis. j clin periodontol 2010; 37: 30-6. 7. lang np, et al. international classification workshop: consensus report chronic periodontitis. annals of periodontol 1999; 4:53. 8. silness j, loe h. periodontal disease in pregnancy. ii. correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22: 121-35. 9. loe h. the gingival index, the plaque index and the retention index system. j periodontol 1967; 38: 610-6. 10. newbrun e. indices to measure gingival bleeding. j periodontol 1996; 67: 555-61. 11. brill n. the gingival pocket fluid studies of its occurrence compositions and effect. acta odontal scand 1969; 20(suppl 32): 159. 12. gupta g. gingival crevicular fluid as a periodontal diagnostic indicator 1: host derived enzymes and tissue breakdown products. j med life 2012; 5: 390-7. 13. perozini c, chibebe pc, leao mv, queiroz cda s, pallos d. gingival crevicular fluid biochemical markers in periodontal disease: across sectional study. quintess int j 2010; 41: 877-83. 14. fadhil r. the association of crevicular albumin level with the severity of periodontal destruction in chronic periodontitis patient after initial periodontal treatment. j baghdad coll dentistry 2014; 26(1): 134-7. 15. megson d. c-reactive protein periodontitis and systemic inflammation. a master thesis. department of periodontics, school of dentistry, university of adelaide, 2011. 16. al-safi kh, al-jawady gh. relationship between periodontal disease and c-reactive protein among hypertensive patients under ß-blocker antihypertensive drug. iraqi dental j 2012; 34. 17. noack b, genco rj, trevisan m, grossi s, zambon jj, de nardin e. periodontal contribute to elevated systemic c-reactive protein level. j periodontol 2001; 72: 1221-7. 18. macovei as, pasarin l, potarniche o, martu s. identification of c-reactive protein from gingival crevicular fluid in systemic disease. romanian j oral rehabil 2012; 4: 67-71. 19. cairo f, castellani s, gori am, nieri m, baldelli g, abbate r, pini-prato gp. severe periodontitis in young adults is associated with sub-clinical atherosclerosis. j clin periodontol 2008; 35: 465-72. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 12 research article compliance of patients with class iii malocclusion to orthodontic treatment zaid alaa abdulhussein 1,*, alev aksoy 1 1 süleyman demirel university, faculty of dentistry, department of orthodontics, 32100, isparta, turkey * correspondence: drzaidalaa@gmail.com abstract: background: although the new treatment methods developed in recent years are aiming to minimize the need for cooperation of the patients; however, the latter still important factor the treatment. the aim of the study was to evaluate the cooperation level of class iii malocclusion patients with orthodontic treatment. materials and methods: this study followed a cross-sectional style; the targeted population was patients with class iii malocclusion who were treated with three different types of orthopaedic appliances. four questionnaires were delivered to the patient, patient’s parents, and orthodontists. statistical analyses of the study were performed with spss 20.0 software. descriptive analyses were presented using frequency, percentage, mean, and standard deviation. results: the study included a total of 183 orthodontic patients in the final analysis. slightly more than half of the participants were females (52.46%; n=96) and the rest were male (47.54%; n=87). the highest frequency according to the device type was fm (50.8%) followed by cc (31.1%) while fm+rme wearer was 18.1%. male expressed significantly higher (p <0.05) cooperation and tendency levels towards treatment than females. cooperation level was also significantly associated with the parents’ monitoring and motivation. conclusion: males had higher levels of treatment desire and cooperation than females during the treatment of class iii malocclusion. in addition, results emphasized the role of the motivational effect of the parent on the positive cooperation of the patients. keywords: questionnaire, patients compliance, class iii malocclusion introduction class iii malocclusion is one of the most difficult malocclusions in terms of diagnosis and treatment especially in mixed and late deciduous dentation (1). it was first described by angel according to the position of the molars during occlusion (2). later, tweed further classified class iii malocclusion into two subcategories; pseudo class iii malocclusion and skeletal class iii malocclusion (2). the early intervention during the growth period of a child with class iii skeletal malocclusion using orthopaedic appliances (extra oral or intra oral) is a very common treatment approach with highly successful results. however, these devices are not aesthetically acceptable and require full cooperation from the young patients (3-6). according to proffit, class iii malocclusion treatment should be started as soon as possible with the ideal age of 8 years (7, 8). in most cases, the best time to start the treatment of class iii malocclusion is when the diagnosis is confirmed by the orthodontist (9). the importance of patient cooperation for the success of orthodontic treatment has been emphasized by many researchers (10-12). from orthodontic point of view, the cooperative patient is described as an individual with good oral hygiene, wears the devices as they are told, follows an appropriate diet, and received date: 12-2-2022 accepted date: 8-3-2022 published date: 15-3-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/jbcd .v34i1.3087 mailto:drzaidalaa@gmail.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3087 https://doi.org/10.26477/jbcd.v34i1.3087 j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 13 fallows the instruction given by the orthodontist (13). in addition, the cooperative patient could be described as the patient who comply to the given appointments on time, maintains optimum oral hygiene, uses the device as instructed, and takes care of the appliances whether fixed or removable (10, 11). usually, the patient cooperation may be affected by some factors such as sex, age, social class, personality and severity of malocclusion. a problem that may occur in cooperation may lead to deviation from the ideal treatment plan, prolongation of the treatment period and even early termination of the treatment without reaching desirable outcomes. the degree of the expected cooperation from the orthodontic patient depends on many factors such as age, sex, socioeconomic status, demographic factors (14, 15), patient-family relations (16-18), patient and family's desire for orthodontic treatment, patient's personality characteristics (14, 15, 18-20), and perception of malocclusion (21). allan and hodgson stated that age is important in predicting patient’s cooperation. since pre-adolescent children are more prone to accept and implement the demands of their families, it is possible to provide cooperation with the influence of the family (14). some studies have suggested that patient sex my help to predict the patient cooperation during the treatment as females appears to be more adaptable to the treatment than males. nevertheless, the satisfaction level with the appearance is lower in females than males, thus this feature could negatively affect the use of special appliances needed during the treatment (22). additionally, the socio-economic status may have an effect on patient’s cooperation. it has been suggested that patients with high socio-economic level cooperate better than patients with low socio-economic level (23). the aim of the study was to evaluate the compliance of patients with class iii malocclusion to orthodontic treatment using different types of orthopaedic appliances. materials and methods study design this study followed a cross-sectional design and was conducted after obtaining the ethical approval from faculty of medicine clinical research ethics committee, süleyman demirel university. it was carried out in the department of orthodontics, faculty of dentistry, süleyman demirel university from september 2019 to july 2020 the targeted population was patients with class iii malocclusion who were treated with three different types of orthopaedic appliances. after obtaining a signed consent from each patient’s guardian, a questionnaire was delivered to the patient, patient’s parents and the treating orthodontist. j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 14 study population the following information was recorded for each patient including date of birth, sex, educational backgrounds and occupations of their parents. eligibility for enrolment of the patients was decided according to the following inclusion/exclusion criteria: inclusion criteria: 1. the absence of any craniofacial anomalies congenital or acquired deformity, any muscle disease or systemic disorders. 2. no previous orthodontic treatment. 3. patients between the ages of 9-17 years. 4. the presence of class iii dental or skeletal malocclusion. 5. late mixed deciduous or permanent dentition, 6. the treatment is carried either by chin cup (cc), face mask (fm) or face mask with rapid maxillary expansion (fm+rme). exclusion criteria: 1. the presence of either class i or class ii anomaly, 2. complete completion of the skeletal growth-development period (17 years and over), 3. the presence of congenital missing teeth 4. having any systemic or psychological disorder, 5. patients receiving dental or skeletal class iii treatment but not using fm, cc or fm+rme, 6. treatment time is less than 4 months. elements of the questionnaire the questioners used in the study were the orthodontic attitude survey-oas (questionnaire 1), the orthodontic locus of control scale (olocs) (questionnaire 2) parent questionnaire (questionnaire 3) and orthodontic patient cooperation scale-opcs (questionnaire4). these questionnaires were adopted and translated to turkish. their reliability and validity were determined by previous studies (11, 24). in this study, questionnaire forms were filled during the treatment. before filling out the questionnaires, all individuals were informed verbally by the main investigator that they should carefully read all the questions, answer them honestly, not get help from anyone while answering the questions and they should answer thoughtfully expressing their opinions (25). j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 15 the first questionnaire (orthodontic attitude survey-oas) was composed of 21 questions dedicated to evaluate the attitude and behaviour towards orthodontic treatment. a score of 1-5 was given to each question. the section regarding the appliance use consisted of five questions with a score between 5 and 25. the section regarding the patient’s opinion towards his/her own occlusion was consisted of two questions with score 5 to 10. the importance of the occlusion in the orthodontic treatment is presented in 16th question. the patient’s prospective of the treatment consisted of four questions with average score value of 5 to 20. the 18th question asked about the features the patient did not like in their dentation. the 20th question asked about the person who had the effect on the starting of treatment. the second questionnaire consisted of 31-item adapted from orthodontic locus of control scale (olocs)(26) and translated from english to turkish (figure 1) aimed to evaluate the attitude of the patients towered their own occlusion and their awareness about the responsibilities required by them during the treatment. in addition, the degree to which the patients are affected by internal or external factors (personal and environmental factors) was assessed. all questions were scored according to 5-points likert scale. external locus of control consisted of four questions (#10, #14, and #17). theoretically expected point value was in the range of 5-20. internal locus of control consisted of a total of ten questions numbered (#1 to #7, #9, #16, #22) with an expected score in the range of 5-45. the external family locus of control consisted of seven questions (#18 to #22, #24). the theoretically expected score range here is 5-30. the third questionnaire, filled out by the parents, included questions relating to the behaviour of the child. the scoring system was made with 5-points likert scale. the first question was about the treatment expenses and how it had been paid. the second question was related to the idea about the treatment need, the third question was about the child desire for treatment, the fourth question was about the child idea about his/her teeth, and the fifth question was about the parents’ opinion about the need for treatment, while the sixth question asked about the patient attitude towards the treatment. the fourth questionnaire was filed by the orthodontist who agreed to participate in the study. slakter et al. designed this scale in relation to appointment tracking and appliance storage. it examined the effect of oral hygiene on the treatment approach to measure the individual's cooperation. five questions of opcs containing negative statements are scored in reverse and five questions were evaluated as positive a score of 1 to 5 point are given to each question. sample size calculation g power 9.1.2 (universitaet kiel, germany) software was used for estimating sample size of the study. power analysis was performed using the scale score and cooperation information obtained from the pilot studies. using the behavioural scale information, the effect size was calculated as 0.63. the effect size was calculated as 0.41 using the control scale score. the minimum effect size was chosen for the larger sample. for cc, face mask and fm with rme device types, the f test and one-way analysis of variance were selected, the margin of error was 5% and the power value was 0.95, and the sample size was j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 16 calculated as 32 for each group. during the study period, this value was exceeded and a higher number of study groups were determined. figure 1: orthodontic locus of control scale (olocs)(26) questionnaire statistical analysis statistical analyses of the study were performed with spss 20.0 (ibm inc., chicago, il, usa) program. descriptive measures were presented using tables as frequency, percentage, mean, and standard deviation. the conformity of the questionnaire scores to the normal distribution was analysed by the kolmogorov-smirnov method. student t-test was used for comparisons between two independent groups. chi-square analysis with monte carlo correction was used to determine the relationships between categorical variables, and pearson’s correlation analysis was used to determine the relationships between numerical variables. the type-i error value was taken as 5% in the entire study, and the p <0.05 value was considered statistically significant. j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 17 results this study included a total of 183 orthodontic patients in the final analysis. females represented 52.46% (n=96) and the rest were males (47.54%; n=87). the most common device type was fm (50.8%; n=93) followed by cc (31.1%) while fm+rme was the lowest (18.1%). there was no significant difference of device type distribution according to sex (table.1). table 1: device distribution according to sex device type sex p value* male female chin cup 33 (37.90%) 24 (25.00%) 0.116 face mask 42 (48.30%) 51 (53.10%) face mask+ rapid maxillary expansion 12 (13.80%) 21 (21.90%) * significance at p <0.05 by chi square test a significant difference was observed between male and female in the score regarding the treatment desire and preferences in all three groups. briefly, male preferred having straight teeth over summer vacation whatever the device type used. while 37.5% of females in the cc group (p<0.001), fm group 23.5% (p=0.001), fm+rme group 28.6% (p=0.041) did not prefer the orthodontic treatment (table2). table.2: orthodontic treatment preference according to device types device type sex p value* male female chin cup summer vacation 0 (0.00%) 9 (37.50%) <0.001* straight teeth 33 (100.00%) 15 (62.50%) face mask summer vacation 0 (0.00%) 12 (23.50%) 0.001* straight teeth 42 (100.00%) 39 (76.50%) face mask+ rapid maxillary expansion summer vacation 0 (0.00%) 6 (28.60%) 0.041* straight teeth 12 (100.00%) 15 (71.40%) * significance at p <0.05 by chi square test the importance given by the patient to their own occlusion for those using cc and rme devices did not differ significantly between sexes (table 3). while in patient using fm, 50% of the males considered their occlusion very important and 82% of the females stated that their occlusion is absolutely important. in patients using a cc device, the importance giving to the orthodontist instructions regarding the treatment was found to be higher in males, while the "somewhat important" option was selected by 12.5% of females (p=0.002). in patients using fm and fm+rme, there was not significantly different between both sexes (table.4). the need for orthodontic treatment realization rate in females who used cc device was found to be significantly higher (p=0.018) than male; however, there was no significant difference in patients using fm. the frequency of females, using fm+rme device, who realized the need for treatment was found to be significantly high (p<0.001) as compared to male (table.5). on the other hand, there was no significant difference according to the sex regarding the person who had the impact on the decision to start the orthodontic treatment (table.6). j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 18 table.3: importance of occlusion according to sex and device types device type sex p value* male female chin cup absolutely important 21 (63.60%) 21 (87.50%) 0.459 very important 12 (36.40%) 0 (0.00%) important 0 (0.00%) 3 (12.50%) face mask absolutely important 21 (50.00%) 42 (82.40%) 0.020* very important 21 (50.00%) 6 (11.80%) important 0 (0.00%) 3 (5.90%) face mask+ rapid maxillary expansion absolutely important 9 (75.00%) 12 (57.10%) 0.092 very important 3 (25.00%) 3 (14.30%) important 0 (0.00%) 3 (14.30%) somewhat important 0 (0.00%) 3 (14.30%) * significance at p <0.05 by chi square test table 4: consideration of orthodontist instruction according to device types device type sex p value* male female chin cup very important 30 (90.90%) 12 (50.00%) 0.002* important 3 (9.10%) 9 (37.50%) somewhat important 0 (0.00%) 3 (12.50%) face mask very important 33 (100.00%) 24 (100.00%) 0.124 important 33 (78.60%) 30 (58.80%) somewhat important 6 (14.30%) 15 (29.40%) face mask+ rapid maxillary expansion very important 12 (100.00%) 18 (85.70%) 0.170 important 0 (0.00%) 3 (14.30%) * significance at p <0.05 by chi square test the scale scores were compared according to sex (table.7). the scale scores obtained from the questionnaire forms filled by patients, parents and orthodontist did not differ significantly between both sexes. in the correlation analysis performed between the scale scores, a low level of significant and positive correlation was found between the behaviour score and the other scales (table.8). the patients' behavioural cooperation scale and orthodontic treatment control score were low and positive (r=0.163; p=0.027). a significant and positive correlation were observed in association with parents’ cooperation (r=0.154; of p=0.037) and with the patient-orthodontist cooperation (r=0.577; p<0.001). there was no significant relationship between the control scale and the parent and orthodontist cooperation scales. a low level of positive correlation (r=0.176; p=0.017) was found between parent and orthodontist cooperation scales. j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 19 table 5: orthodontic treatment needs according to device types device type sex p value* male female chin cup by the warning of my friends 3 (9.10%) 0 (0.00%) 0.018* by the warning of the dentist 27 (81.80%) 18 (75.00%) by the warning of my family 3 (9.10%) 3 (12.50%) i notice it myself 0 (0.00%) 3 (12.50%) face mask by the warning of the dentist 33 (78.60%) 39 (76.50%) 0.451 by the warning of my family 9 (21.40%) 9 (17.60%) i notice it myself 0 (0.00%) 3 (5.90%) face mask+ rapid maxillary expansion by the warning of the dentist 6 (50.00%) 3 (14.30%) <0.001* by the warning of my family 6 (50.00%) 3 (14.30%) i notice it myself 0 (0.00%) 15 (71.40%) * significance at p <0.05 by chi square test table 6: people who influence the treatment decision by device type device type sex p value* male female chin cup dentist advice 12 (36.40%) 9 (37.50%) 0.931 family advice 21 (63.60%) 15 (62.50%) face mask dentist advice 15 (35.70%) 24 (47.10%) 0.635 family advice 27 (64.30%) 24 (47.10%) my self 0 (0.00%) 3 (5.90%) face mask+ rapid maxillary expansion friends’ advice 3 (25.00%) 0 (0.00%) 0.195 dentist’s advice 0 (0.00%) 6 (28.60%) family advice 9 (75.00%) 12 (57.10%) my self 0 (0.00%) 3 (14.30%) * significance at p <0.05 by chi square test table 7: scale general scores by sex in detail on device types device type sex behaviour score mean ± sd control score mean ± sd parent score mean ± sd orthodontist score mean ± sd chin cup male 64.09±7.83 95.09±11.75 16.90±2.54 21.96±4.39 female 66.00±6.17 96.75±5.49 16.37±3.18 22.04±4.41 p value 0.326 0.524 0.485 0.952 face mask male 62.33±8.55 96.28±9.67 17.35±2.80 22.21±4.28 female 62.86±10.69 97.88±12.54 16.25±2.69 22.01±4.19 p value 0.796 0.501 0.057 0.826 face mask+ rapid maxillary expansion male 62.75±2.00 101.00±4.45 16.91±2.35 20.50±0.90 female 64.14±6.27 94.66±10.59 15.80±3.01 20.00±2.81 p value 0.463 0.059 0.282 0.565 j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 20 table 8: correlation values between scale scores control score parent score orthodontist score behaviour score r 0.163 0.154 0.577 p 0.027* 0.037* <0.001* control score r -0.013 -0.036 p 0.865 0.633 parent score r 0.176 p 0.017* r: correlation coefficient * significance at p <0.05 by pearson’s correlation discussion class iii malocclusion considered one of the challenging conditions in terms of diagnosis and treatment. treatment could be started during the period of growth using either extra oral or intraoral appliances in order to stimulate or modify the growth of the maxilla or inhibit the growth of the mandible. these appliances utilize the orthodontic force to correct the sagittal disharmony between the maxilla and the mandible. due to the fact these types of appliances controlled mainly by the patient and should wear the appliance for at least 14-18 hours per day, therefore, cooperation of the patient is required to achieve desirable outcomes. nevertheless, compliance of the patient is not easily obtained due to the fact that the design of these appliances is bulky and not aesthetically acceptable which is not tolerated well by the child. in addition, the young patients are potentially subjected to bullying by their peers which increase the difficulty to convince the child to wear the appliance. indeed, psychological analyses are useful tools for measuring patient’s cooperation during treatment and guide the orthodontists about patient-specific treatment approach. in our study, the aim was to measure and correlate the cooperation for three types of appliances used for treatment of class iii malocclusion. this was achieved by using four, previously validated, questionnaires including oas, olocs, cce, opcs (27). patients selected for this study had started the treatment for at least 4 months depending on the results obtained by slakter et.al which stated that in order to measure the cooperation of the patient a period of 4 to 8 months should passed in order to establish a solid communication between the patient and the orthodontist (28). while some studies stated that the socio-economic level is a crucial factor for patients’ cooperation, other studies claimed the opposite (23, 29). sergal et al., suggested that the socio-economic status of the family is not a detrimental factor to obtain cooperation of the patient (30). results of current study could not confirm nor contradict this notion since treatment expenses were covered by the health assurance provided by the government i.e., standardized the socio-economic factor for all the patients included in the study. j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 21 age of the patient is another factor that could affect the level of cooperation. previous studies showed heterogeneity when selecting the age limit. for instance, some reported an age range of 12-15 years (31) or 11-14 years (32-35) or the age limit was set at 16 years (36, 37), while in other studies age standardizing was preferred (24, 28, 38, 39). a questionnaire-based study conducted by verda et al. at istanbul university, the age limit was determined between 11 and 16 (40). in this study, the age range was determined between 9 and 17 years due to the fact that class iii malocclusion treatment mainly starts at the age of 9 years old. these variations in age groups could explain the differences in results obtained by the aforementioned studies. according to available literature, orthodontic treatment is more accepted by the females who also more cooperative compare to the males of the same treatment groups. this could be explained that the female are more concerned about their appearance and the aesthetic of their dentation than male (41, 42). this notion has been supported by results of karaman et al who showed that the females used the orthodontic appliances as instructed by the orthodontist and tend to be more cooperative than male during the treatment (43). this was inconsistent with results of the current study which indicated that males preferred the orthodontic treatment and had a desire the treatment more than the females in all the three types of devices included in the study. while only 62.5% of cc, 76.5% fm and 71.6% fm+mre the girls preferred the orthodontic treatment. according to a previous study, 80.9% of the patient were motivated by their families; also the majority of the patient, even in the presence of pain or discomfort during the appliance application, continued to wear the appliances which indicate that a well-motivated patient tends to show a higher degree of cooperation (43). in this study the collective answers of both the patients and the parents showed that the majority of the patients were well motivated by their families. in addition, 56.8% of the parents insisted on the treatment even if the patient did not want the treatment at the beginning. further, 85.2% of the patient continued wearing their appliance in order to obtain good-looking dentation which suggested a high motivational level provided by their families. conclusion it can be concluded that males had higher levels of treatment desire and cooperation than females during the treatment of class iii malocclusion i.e., sex could be a predictive independent variable for expecting patient’s cooperation during orthodontic treatment. in addition, results emphasized the role of the motivational effect of the parent on the positive cooperation of the patients. conflict of interest: none. j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 22 references 1. jam j. class iii malocclusion. orthodontics and dentofacial orthodontics. united states of america: needham press, inc.; 2002. 2. bishara 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the use of personality measurements as a determinant of patient cooperation in an orthodontic practice. am j orthod. 1968;54:433-440. 15. sergl hg, klages u and zentner a. functional and social discomfort during orthodontic treatment--effects on compliance and prediction of patients' adaptation by personality variables. eur j orthod. 2000;22:307-15. 16. schott tc and göz g. young patients' attitudes toward removable appliance wear times, wear-time instructions and electronic wear-time measurements--results of a questionnaire study. j orofac orthop. 2010;71:108-16. 17. mangoury nh. orthodontic cooperation. am j orthod. 1981;80:604-22. 18. sergl h, klages u and pempera j. on the prediction of dentist-evaluated patient compliance in orthodontics. eur j orthod. 1992;14:463-468. 19. ast db, carlos jp and cons nc. the prevalence and characteristics of malocclusion among senior high school students in upstate new york. am j orthod. 1965;51:437-45. 20. crawford tp. a multiple regression analysis of patient cooperation during orthodontic treatment. am j orthod. 1974;65:436437. 21. nanda rs and kierl mj. prediction of cooperation in orthodontic treatment. am j orthod dentofacial orthop. 1992;102:15-21. 22. miles r. extra-oral force in orthodontics. 1963. 23. cucalon a, 3rd and smith rj. relationship between compliance by adolescent orthodontic patients and performance on psychological tests. angle orthod. 1990;60:107-14. 24. gray m and anderson r. a study of young people's perceptions of their orthodontic need and their experience of orthodontic services. prim dent j. 1998;5:87-93. j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 23 25. haas aj. headgear therapy: the most efficient way to distalize molars. semin orthod. 2000;6:79-90. 26. tedesco la, albino je and cunat jj. reliability and validity of the orthodontic locus of control scale. am j orthod. 1985;88:396401. 27. albino je. development of methodologies for behavioral measurement related to malocclusion: national institute of dental research; 1981. 28. slakter mj, albino je, fox rn and lewis ea. reliability and stability of the orthodontic patient cooperation scale. am j orthod. 1980;78:559-563. 29. graber l. psychological aspects of malocclusion. j cds review. 1975;68:12-15. 30. sergl hg and zentner a. predicting patient compliance in orthodontic treatment. semin orthod. 2000;6:231-236. 31. burns mh. use of a personality rating scale in identifying cooperative and noncooperative orthodontic patients. am j orthod. 1970;57:418. 32. howells dj and shaw wc. the validity and reliability of ratings of dental and facial attractiveness for epidemiologic use. am j orthod. 1985;88:402-8. 33. işık f, sayınsu k, trakyalı g and arun t. hastanın psikolojik durumunun ya da kişilik özelliklerinin ortodontik tedavi başarısı üzerine etkileri. türk ortodonti derg. 2004;17:347-353. 34. sahm g, bartsch a, koch r and witt e. subjective appraisal of orthodontic practices. an investigation into perceived practice characteristics associated with patient and parent treatment satisfaction. eur j orthod. 1991;13:15-21. 35. sergl hg, klages u and zentner a. pain and discomfort during orthodontic treatment: causative factors and effects on compliance. am j orthod dentofacial orthop. 1998;114:684-91. 36. albino je, lawrence sd and tedesco la. psychological and social effects of orthodontic treatment. j behav med. 1994;17:8198. 37. buchanan ib, downing a and stirrups dr. a comparison of the index of orthodontic treatment need applied clinically and to diagnostic records. br j orthod. 1994;21:185-8. 38. kerosuo h, abdulkarim e and kerosuo e. subjective need and orthodontic treatment experience in a middle east country providing free orthodontic services: a questionnaire survey. angle orthod. 2002;72:565-70. 39. richter dd, nanda rs, sinha pk, smith dw and currier gf. effect of behavior modification on patient compliance in orthodontics. angle orthod. 1998;68:123-32. 40. verda c k. ortodontik tedavide hasta kooperasyonun öngörülmesi: maloklüzyon algılanması ile i̇lişkisi,. ortodonti anabilim dalı , sağlık bilimleri enstitüsü,. 2006;doktoratezi. 41. tuominen ml, tuominen r and nyström m. subjective orthodontic treatment need and perceived dental appearance among young finnish adults with and without previous orthodontic treatment. community dent health. 1994;11:29-33. 42. gravely jf. a study of need and demand for orthodontic treatment in two contrasting national health service regions. br j orthod. 1990;17:287-292. 43. ali i̇ k. ortodontik tedavi gören hastalarda headgear ve ağız içi elastik kullanımnın hasta koperasyonu üzereine etkisi. . türk ortodonti dergisi 2002;15 108-15. األسنان امتثال المرضى الذين يعانون من سوء اإلطباق من الدرجة الثالثة لعالج تقويم العنوان: 1اليف اكسوي, 1زيد عالء عبد الحسين الباحثون: المستخلص: الهدف ان في العالج. ا ال يزال مهم العاملهذا على الرغم من أن طرق العالج الجديدة التي تم تطويرها في السنوات األخيرة تهدف إلى تقليل الحاجة إلى تعاون المرضى ؛ ومع ذلك ، فإن الخلفية: . تقييم تعاون المرضى في عالج تقويم األسنان في اإلطباق من الدرجة الثالثة.ل كان الدراسة هذه من م عالجهم بثالثة أنواع مختلفة اتبعت هذه الدراسة أسلوب المقطع العرضي. كان السكان المستهدفون هم المرضى الذين يعانون من سوء اإلطباق من الدرجة الثالثة والذين تالمواد وطرق العمل: استبيان إلى المريض ووالدي المريض وأخصائي تقويم األسنان. من أجهزة تقويم العظام. بعد الحصول على موافقة موقعة من الوصي على كل مريض ، تم تسليم j. bagh. coll. dent. vol. 34, no. 1. 2022 abdulhussein and aksoy 24 )شركة آي بي إم ، شيكاغو ، إلينوي ، الواليات المتحدة األمريكية(. تم عرض المقاييس الوصفية باستخدام الجداول spss 20.0تم إجراء التحليالت اإلحصائية للدراسة باستخدام برنامج النتائج: ( 96٪ ؛ العدد = 52.46مريض ا لتقويم األسنان. كان أكثر من نصف المشاركين بقليل من الفتيات ) 183الدراسة شملت. والمعدل الحسابي واالنحراف المعياريمئوية( حسب التكرار )النسبة ال ٪.18.1 أكثر بقليل من fm + rme كان ما بين %cc (31.1)يليه ؛ fm (50.8%)(. أعلى معدل في مجموعات نوع الجهاز كان87٪ ؛ العدد = 47.54والباقي من الذكور ) باإلناث ، من وجهة نظر مالتقويمي عند مقارنته تظهر النتيجة التي تم الحصول عليها من الدراسة أن الذكور الذين شاركوا في الدراسة لديهم إمكانية أكبر إلظهار التعاون أثناء العالجاالستنتاج: لتعاون المريض. بالعوامل المحددة سريرية ، يمكن أن تكون هذه الدراسات مفيدة من حيث التنبؤ 13sabreen f.docx j bagh college dentistry vol. 28(3), september 2016 expression of syndecan 1 oral diagnosis 82 expression of syndecan 1 on periodontium treated with topical application of aloe-vera sabrin sami abed, b.d.s. (1) athra'a y. al-hijazi, b.d.s., m.sc. ph.d. (2) abstract background: periodontium mainly exposed to injury by trauma or pathologic diseases, aloe vera is a plant has many basic ingredients in its extracted gel that acts as wound healing accelerator in addition to that it's safe, and economical and without recordable of side effect. this study aimed is to evaluate the effect of topical application of aloe vera on expression of syndecan -1 by periodontium tissue. materials and methods: thirty six male albino rats were subjected for periodontium defect by electric scaler on the distal sides of both lower anterior teeth. the animals divided into two groups; control group (without treatment) and the experimental group treated with 1µlaloe vera gel/normal saline. periodontal healing was examined at periods (3, 7, 14 days) for immunohistochemical localization of syndecan 1. results: immunohistochemical examination of this study revealed that the aloe vera treatment increase expression of syndecan 1 by epithelial cell, osteoblasts, fibroblast, stromal cells and with highly significant differences in comparison with control and saline. conclusion: aloe vera gel may affect the expression of syndecan 1 which seems to play a role in periodontium healing. key words: aloe vera, periodontium, syndecans. (j bagh coll dentistry 2016; 28(3):82-86). introduction periodontium injury healing is a series of biological processes; include migration, adhesion, proliferation, and differentiation of several cell types. all these activities are triggered by chemoattraction of the cells; polypeptide mediators bind to their cell-surface receptors, integrins bind to extracellular matrix components, and different growth factors regulate different cell functions. the process is ending with the formation and maturation of a new extracellular matrix (1-3). syndecan 1 is type-i-transmembrane cell surface heparansulphat proteoglycans (hspgs) (4). syndecan -1 has an essential role in mediating cell proliferation, cell migration, and cell-matrix interactions by binding various extracellular matrix proteins via its heparansulphate chains during wound healing (5-6). aloe vera is a plant has many health benefits such as anti-inflammatory, antibacterial, antiviral, and wound healing acceleration, used in different fields like cosmetology, dermatology, and dentistry (7). aloe vera gel consists of many ingredients such as vitamins, enzymes, minerals, hormones and polysaccharides (acemannan),these contents play important roles in wound healing process. the present study has been prepared to illustrate the effect of local application of aloe vera gel on expression of syndecan -1 in periodontium wound healing. (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. materials and methods animals thirty six albino rats weighting (250-400) gram, aged (6-8) months were used in the present study, maintained under control conditions of temperature, drinking and food consumption. all experimental procedures were carried out in accordance with the ethical principles of animal experimentation. the animals were divided into control and experimental group: a. control group the periodontium defect left without any treatment and its number represented the all number of the following experimental groups as the right side of each animal considered to be the control. b. experimental group was subdivided into following groups according to the applicable of biomaterials includes: • group 1 contains (18) rats, the periodontium defect treated with 1µl normal saline. • group 2 contains (18) rats, the periodontium defect treated with 1µl of a. vera gel. materials aloe vera gel 87.399%, phytocare company. anti-syndecan– 1 monoclonal from abcamcompany uk (ab34164) methods immunohistochemical evaluation the animals were sacrificed at 3,7,14 days (six rats for each period). the specimens were fixed by 10% buffered formalin for 3 days. the samples j bag 1 j bagh college dentistry oral diagnosis then demineralized, paraffin. five prepared for localization of immune syndecan 1. determination of immunohistochemical results for syndecan 1 for each specimen, the number of positive expression of syndeca evaluating 100 cells for each power fields (hpf) counting the positive one, then the mean of count for eight slides for each sample(8) statistic analyse a. descriptive data analysis. b. inferential data analysis figure 1: control group with immunohistochemical expression of syndecan 1 (dab at 3rd x20. (b) at 7 (arrow heads) .dab stain x20. (c) at 14 bone (ab) shows positive immune reaction for syndecan a h college dentistry oral diagnosis then demineralized, dehydrated, and embedded in . five µm prepared for localization of immune syndecan 1. determination of immunohistochemical results for syndecan 1 for each specimen, the number of positive expression of syndeca evaluating 100 cells for each power fields (hpf) counting the positive one, then the mean of count for eight slides for each ). statistic analyses descriptive data analysis. inferential data analysis figure 1: control group with immunohistochemical expression of syndecan 1 (dab rd day, keratinocyte cell (arrow)expressed positive dab stain for syndecan x20. (b) at 7th day, woven bone (wb) shows positive expression of syndecan (arrow heads) .dab stain x20. (c) at 14 bone (ab) shows positive immune reaction for syndecan h college dentistry dehydrated, and embedded in µm thickness of prepared for localization of immune determination of immunohistochemical results for each specimen, the number of positive expression of syndecan 1 was determined by evaluating 100 cells for each slide in five high power fields (hpf) counting the positive one, then the mean of count for eight slides for each descriptive data analysis. inferential data analysis figure 1: control group with immunohistochemical expression of syndecan 1 (dab day, keratinocyte cell (arrow)expressed positive dab stain for syndecan day, woven bone (wb) shows positive expression of syndecan (arrow heads) .dab stain x20. (c) at 14 bone (ab) shows positive immune reaction for syndecan fibroblast shows negative (arrows) .dab stain x20. c h college dentistry vol. 2 dehydrated, and embedded in thickness of section was prepared for localization of immune-reaction of determination of immunohistochemical results for each specimen, the number of positive n 1 was determined by slide in five high power fields (hpf) counting the positive one, then the mean of count for eight slides for each descriptive data analysis. figure 1: control group with immunohistochemical expression of syndecan 1 (dab day, keratinocyte cell (arrow)expressed positive dab stain for syndecan day, woven bone (wb) shows positive expression of syndecan (arrow heads) .dab stain x20. (c) at 14th bone (ab) shows positive immune reaction for syndecan fibroblast shows negative (arrows) .dab stain x20. vol. 28(3), september 83 dehydrated, and embedded in section was reaction of determination of immunohistochemical results for each specimen, the number of positive n 1 was determined by slide in five high power fields (hpf) counting the positive one, then the mean of count for eight slides for each result result for i syndecan 1 in each group osteoblast group records a strong expression shows epithelial cell layers of results was illustrated by lymphocyte in lamina properia ligament shows 3). highly significant differences for the expression of syndecan 1 epithelial cells, cell, bone cells saline groups. figure 1: control group with immunohistochemical expression of syndecan 1 (dab day, keratinocyte cell (arrow)expressed positive dab stain for syndecan day, woven bone (wb) shows positive expression of syndecan th day,view for periodontal ligament (pdl) , alveolar bone (ab) shows positive immune reaction for syndecan fibroblast shows negative (arrows) .dab stain x20. b september 2016 results result for immuno syndecan 1 expression of syndecan 1 in each group was osteoblast cell, group records a strong expression shows a negative expression of syndecan epithelial cell layers of results was illustrated by lymphocyte in lamina properia. some f ligament shows 3). table (1) shows that highly significant differences for the expression of syndecan 1 epithelial cells, cell, bone cells saline groups. figure 1: control group with immunohistochemical expression of syndecan 1 (dab day, keratinocyte cell (arrow)expressed positive dab stain for syndecan day, woven bone (wb) shows positive expression of syndecan day,view for periodontal ligament (pdl) , alveolar bone (ab) shows positive immune reaction for syndecan -1 by cementoblast (arrow heads) fibroblast shows negative (arrows) .dab stain x20. 2016 mmunohistochemical expression of syndecan 1 was detected by cementoblast cell, cell, and keratinocyte group records a strong expression negative expression of syndecan epithelial cell layers of gingivae, while results was illustrated by lymphocyte in lamina some fibroblasts cell in periodontal ligament shows negative expression shows that a. highly significant differences for the expression of in periodontium cells include epithelial cells, stromal cell, cell, bone cells in comparison figure 1: control group with immunohistochemical expression of syndecan 1 (dab day, keratinocyte cell (arrow)expressed positive dab stain for syndecan day, woven bone (wb) shows positive expression of syndecan day,view for periodontal ligament (pdl) , alveolar 1 by cementoblast (arrow heads) fibroblast shows negative (arrows) .dab stain x20. expression of syndecan histochemical findings expression of syndecan 1for over all periods detected by cementoblast cell, and keratinocyte. experimental group records a strong expression .saline group negative expression of syndecan gingivae, while a positive results was illustrated by lymphocyte in lamina ibroblasts cell in periodontal negative expression (figure vera group records a highly significant differences for the expression of in periodontium cells include stromal cell, periodontal ligament comparison to control and figure 1: control group with immunohistochemical expression of syndecan 1 (dab stain) ( day, keratinocyte cell (arrow)expressed positive dab stain for syndecan -1.dab stain day, woven bone (wb) shows positive expression of syndecan -1by osteoblast day,view for periodontal ligament (pdl) , alveolar 1 by cementoblast (arrow heads) expression of syndecan findings of for over all periods detected by cementoblast cell, xperimental aline group negative expression of syndecan-1 in a positive results was illustrated by lymphocyte in lamina ibroblasts cell in periodontal figures1, 2, group records a highly significant differences for the expression of in periodontium cells include dontal ligament to control and stain) (a) 1.dab stain 1by osteoblast day,view for periodontal ligament (pdl) , alveolar 1 by cementoblast (arrow heads) while expression of syndecan j bag 1 j bagh college dentistry oral diagnosis figure 2 1 (dabstain). ( expression for syndecan (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive expression of syndecan saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 figure (dab basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain x 10. (b) a a h college dentistry oral diagnosis 2: experimental group (normal saline) with immunohistochemical expression of syndecan 1 (dabstain). (a) at 3 expression for syndecan (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive sion of syndecan saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 figure 3: experimental group (dab stain). (a) at 3 basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain x 10. (b) at 7th day, lamina propria (lp) shows positive expression of syndecan a h college dentistry experimental group (normal saline) with immunohistochemical expression of syndecan a) at 3rd day, epithelial cell (ep) of gingiva of saline group shows negative expression for syndecan -1 ,while lamina properia (lp) shows positive expression by lymphocyte (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive sion of syndecan -1 .dab stain x40. (c) at 14 saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 experimental group a) at 3rd day, positive expression of syndecan basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain day, lamina propria (lp) shows positive expression of syndecan c c h college dentistry vol. 2 experimental group (normal saline) with immunohistochemical expression of syndecan day, epithelial cell (ep) of gingiva of saline group shows negative 1 ,while lamina properia (lp) shows positive expression by lymphocyte (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive 1 .dab stain x40. (c) at 14 saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 experimental group (aloe vera) with day, positive expression of syndecan basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain day, lamina propria (lp) shows positive expression of syndecan c c vol. 28(3), september 84 experimental group (normal saline) with immunohistochemical expression of syndecan day, epithelial cell (ep) of gingiva of saline group shows negative 1 ,while lamina properia (lp) shows positive expression by lymphocyte (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive 1 .dab stain x40. (c) at 14th saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 (aloe vera) with immunohistochemical expression of syndecan 1 day, positive expression of syndecan basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain day, lamina propria (lp) shows positive expression of syndecan b b september 2016 experimental group (normal saline) with immunohistochemical expression of syndecan day, epithelial cell (ep) of gingiva of saline group shows negative 1 ,while lamina properia (lp) shows positive expression by lymphocyte (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive th day, positive expression of syndecan saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 immunohistochemical expression of syndecan 1 day, positive expression of syndecan -1 by keratinocyte cells include basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain day, lamina propria (lp) shows positive expression of syndecan 2016 experimental group (normal saline) with immunohistochemical expression of syndecan day, epithelial cell (ep) of gingiva of saline group shows negative 1 ,while lamina properia (lp) shows positive expression by lymphocyte (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive day, positive expression of syndecan saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 immunohistochemical expression of syndecan 1 1 by keratinocyte cells include basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain day, lamina propria (lp) shows positive expression of syndecan expression of syndecan experimental group (normal saline) with immunohistochemical expression of syndecan day, epithelial cell (ep) of gingiva of saline group shows negative 1 ,while lamina properia (lp) shows positive expression by lymphocyte (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive day, positive expression of syndecan saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 immunohistochemical expression of syndecan 1 1 by keratinocyte cells include basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain day, lamina propria (lp) shows positive expression of syndecan -1 by plasma expression of syndecan experimental group (normal saline) with immunohistochemical expression of syndecan day, epithelial cell (ep) of gingiva of saline group shows negative 1 ,while lamina properia (lp) shows positive expression by lymphocyte (arrow).dab stain x20. (b) magnifying view for lymphocyte cell (arrows) with positive day, positive expression of syndecan -1 in saline group by sulcular epithelia (red arrow) ,inflammatory cell (pink arrows).dab stian x20 immunohistochemical expression of syndecan 1 1 by keratinocyte cells include basal cell (red arrow heads),prickle cell (redarrows),inflammatory cell (pink arrows).dab stain 1 by plasma expression of syndecan j bagh college dentistry vol. 28(3), september 2016 expression of syndecan 1 oral diagnosis 85 cell (red arrows), endothelial cell (pink arrows ), lining blood vessel (bv). dab stain x40. (c) at 14th day, osteoclast (arrow) illustrates positive. dab stain x20 table1: statistic analysis of positive expressed cells for syndecan 1 in the studied groups with comparisons significant type of pos. groups no. m sd se min. max. levene's test anova test l p-value f p-value epithelial cell saline 6 2 0.52 0.21 1 2 0.308 0.740 ns 81.47 0.000 hs control 6 4 0.89 0.37 3 5 aloe vera 6 8 1.10 0.45 6 9 stromal cells (ging.) saline 6 4 0.98 0.40 3 5 4.308 0.033 s 20.21 0.000 hs control 6 7 1.67 0.68 5 9 aloe vera 6 8 0.52 0.21 8 9 periodontal ligament saline 6 8 0.82 0.33 7 9 5.281 0.018 s 59.69 0.000 hs control 6 9 0.41 0.17 8 9 aloe vera 6 13 1.37 0.56 12 15 bone cells saline 6 6 0.63 0.26 5 7 8.015 0.004 hs 74.31 0.000 hs control 6 11 1.72 0.70 9 13 aloe vera 6 20 2.88 1.17 17 24 (*) hs: highly sig. at p<0.01; s: sig. at p<0.05; ns: non sig. at p>0.05 discussion the present study used aloe vera gel in periodontium defect related to its ability to accelerate wound healing. aloe vera increased syndecan 1 expression in epithelial cells, precursor progenitor cells and in early stage of cell proliferation of mesenchymal cell, and in inflammatory cells, and cementoblast. these results were in agreement with filatova et al. (9) study, who show that syndecan-1 is distributed in distinct areas of the epithelium and mesenchyme during the early and late stages of odontogenesis, and with bernfield et al. (10) and kero et al. (11) that reported syndecan-1 is the major syndecan in epithelial cells. positive expression of syndecan-1 in keratinocyte was reported in the present study and this is in agreement with stepp (12) who suggested that syndecan -1 has a role as a regulator of gene transcription in keratinocytes and keratinocyte activation after injury. the present results illustrates positive immune reaction for syndecan1 by osteoclast in their active stage, these results coincide with pap and bertrand (13) who found that syndecan-1 present in both osteoblasts and osteoclasts of the alveolar bone that make syndecan-1 may play a role in alveolar bone formation and remodeling. present findings for saline group which associated with high inflammatory score, shows negative expression of syndecan-1 in epithelial cell layers of gingiva, while lamina properia shows positive expression by lymphocyte.this result coincides with götte et al.(14) who found that expression of syndecan-1 in suprabasal keratinocytes of the epithelium was weak or absent in inflamed tissue. some fibroblast cells show negative expression of syndecan -1, these findings may explained by some cells have the same histological feature of fibroblast and could be myofibroblast cell that appeared mostly in wound tissue. in conclusion, aloe vera gel increased expression of syndecan -1 in periodontium wound as a result to its property in accelerating biological processes of wound healing. references 1. cillo c, cantile m, faiella a, boncinelli e. homeobox genes in normal and malignant cells. j cell physiol 2001; 188:161-9. 2. conway em, collen d, carmeliet p. molecular mechanisms of blood vessel growth. cardiovasc res 2001; 49: 507-21. 3. alpiste-illueca fm, buitrago-vera p, de gradocabanilles p, fuenmayor-fernandez v, gil-loscos fj. periodontal regeneration in clinical practice. med oral patol oral cir bucal 2006; 11: e382-92. 4. kero d, kalibovicgovorko d, vukojevic k, cubela m, soljic v, saraga-babi m. expression of cytokeratin 8, vimentin, syndecan-1 and ki-67 during human tooth development. j mol histol 2014; 45: 627–40. 5. stepp ma. defects in keratinocyte activation during wound healing in the syndecan-1-deficient mouse. j cell sci 2002; 115: 4517–31. 6. teng yhf, aquino rs, park pw. molecular functions of syndecan-1 in disease. matrix biol 2012; 31: 3–16. 7. sambhav j, rohit r. aloe-vera: a boon in management of dental disease. int j pharm res sci 2014; 2(1): 18-24. 8. piatelli a, rubini c, fioroni m, tripodid, strocchi r. transforming growth factorbeta 1 expression in normal healthy pulps and in those with irreversible pulpitis. int endod j 2004; 37:114-9. 9. anna f, thimois pm. distribution of syndecan-1 protein in developing mouse teeth. front physiol 2015; 5: 518. j bagh college dentistry vol. 28(3), september 2016 expression of syndecan 1 oral diagnosis 86 10. merton b, martin g, woo pp, ofer r, marilyn l, et al. functions of cell surface heparan sulfate proteoglycans. annu rev biochem 1999; 68:729–77 11. kero d, govorko d, vukojevic k, cubela m, soljic v, saraga-babic m. expression of cytokeratin 8, vimentin, syndecan-1 and ki-67 during human tooth development. j mol histol 2014; 45: 627–40. 12. stepp ma. defects in keratinocyte activation during wound healing in the syndecan-1-deficient mouse. j. cell sci 2002; 115: 4517–31. 13. pap t, bertrand j. syndecans in cartilage breakdown and synovial inflammation. nat rev rheumatol 2013; 9; 43–55. 14. martin g, christian k, isabel r; kiesel, pia lw. an expression signature of syndecan-1 (cd138), ecadherin and c-met is associated with factors of angiogenesis and lymphangiogenesis in ductal breast carcinoma in situ. breast cancer res 2007; 9(1): r8. j bagh college dentistry vol. 29(1), march 2017 variation oral diagnosis 63 variation in immunohistochemical expression of neuropilin1 among oral, laryngeal and skin scc khaled j abed, b.d.s. (1) wassan h younis, b.d.s., m.sc., phd. (2) abstract background: neuropilin 1(nrp1) is considered a novel non tyrosine kinase coreceptor for the vascular endothelial growth factors (vegf). first discovered on migrating neurons. nrp1is suggested to be up-regulated in cells of different types of cancer and implicated with advanced disease. the aim of this study was to investigate the variation in expression of nrp1 in oral, laryngeal and skin squamous cell carcinoma. materials and methods: tissue sections from 120 formalin fixedparaffin embedded blocks histopathologically diagnosed as oral, laryngeal and skin scc (40 blocks for each),immunohistohemically stained in immunoperoxidase method with monoclonal antibodies to nrp1, the localization of expression was examined and the resulting scores were analyzed according to age, sex, and histopathological grades. results: the immunohistochemical analysis revealed that the nrp1 expression in oral, laryngeal and skin squamous cell carcinoma was (87.5%), (92.2%) and (82.5%) respectively, with no significant variation in expression among them(p=0.44), but, nrp1 up-regulation in all the three types correlated positively with degree of differentiation (p=0.009), (p=0.002) and (p=0.007) respectively. conclusion: angiogenesis play an important and similar role in carcinogenesis of oral, laryngeal and skin squamous cell carcinoma, and nrp1 is significantly associated with degree of differentiation in the three types of carcinomaso it can be act as a prognostic marker. keywords: neuropilin-1, vegf, squamous cell carcinoma, immunohistochemistry, expression. (j bagh coll dentistry 2017; 29(1)):63-69). introduction cancer angiogenesis is a crucial process in growth of tumor as it ensures nutrient and oxygen to the proliferating malignant cells by development of new blood vessels, leading to progression and metastasis of cancer (1). the progression of the tumor from a non-angiogenic to an angiogenic phenotype is known as the angiogenic switch. this angiogenic switch is triggered by signals like metabolic stress (low ph, low oxygen pressure), mechanical stress, inflammatory response, and genetic mutations (2) . the vascular endothelial growth factors family involved in process of angiogenesis (3). vegfs play an important role in angiogenesis of cancer by stimulating the growth of new blood vessels within the tumor (4). vegfs initiate their biological effect by binding to specific tyrosine kinase receptors (vegfr1, vegfr2 and vegfr3) in addition to nontyrosine kinase coreceptors like neuropilins 1 and 2 (5) . neuropilin 1 is a protein which is encoded by nrp1 gene in humans (6). nrp1 has been implicated in extensive range of functions that range from immunological responses to cell (1) phd. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. adhesion via interaction with integrins (7). nrp-1 expression increase stumorigenisity by promoting vegfs mediated angiogenesis (8). it is expressed on numerous types of cancerous cells. in several cancers the expression is associated with progression of tumor and/or bad prognosis (9). high levels of nrp1 is associated with cancer aggressiveness, advanced stage and unfavorable prognosis (10). up-regulation of nrp-1 is correlated with invasive behavior and metastatic potential of tumors (11). materials and methods a total of one-hundred and twenty cases of formalin-fixed, paraffin embedded tissue blocksthat histo-pathologically diagnosed as oral, laryngeal and cutaneous squamous cell carcinoma ( fourty blocks for each type) were included in the study. oral squamous cell carcinoma blocks were collected from the archives of oral pathology department, college of dentistry, university of baghdad, while the laryngeal and cutaneous squamous cell carcinoma cases were obtained from histopathology laboratory of ghazi al hariry hospital ofspecialized surgeries for the period from october 2014 till june 2015.immunohistochemical analysis was performed on the samples to evaluate the expression of nrp1. five micron thick tissue sections of the blocks were mounted on positively charged slides, dewaxed and rehydrated in xylene j bagh college dentistry vol. 29(1), march 2017 variation oral diagnosis 64 and serial dilutions of ethanol. endogenous peroxidase activity and non-specific antibody binding were blocked with h2o2 and protein block respectively. after blocking , the antigens were retrieved in a hot solution (100x citrate buffer ph 6.0) for 10 minutes the sections were incubated with a rabbit polyclonal anti-nrp1 antibody [epr3113] diluted into (1∶1000) for 6 hours. subsequently, biotin free-hrp linked secondary antibodies were applied. followed by application of diluted dab (chromogenic solution) onto sections and counterstained with hematoxylin. immunoreactivity was semiquantitatively evaluated for positivelystained cells showing immunoreactivity on the cell membrane and/or cytoplasm in five representative microscopic fields. then calculating the percentage of positive considered cells. the expression of nrp-1 in tissue sections was evaluated 0 when no positive stained cells observed, score 1 (weak) in case of < 30% of tumor cells were positive, score 2(moderate) when 3060% of positive cells identified and score 3(strong) when< 60% of tumor cells counted (12). statistical analysis was performed using the spss version 21 computer software in association with microsoft excel. the statistical significance of variations in median was tested via kruskal wallis test, and correlations were assessed by spearman rank linear correlation coefficient. results table (1)shows that, most of the cases of oral, laryngeal and skin squamous cell carcinoma the age ranged from 50 to 69 years with (50%) for oscc, (80%) for lscc and (47%) for skin scc. also, this table showed that most of patients were males in oral, laryngeal and skin scc, (52.5%), (72.5%) and ( 67.5%) respectively. according to table (2),well differentiated grade was the most frequentin oscc 18 cases (45.0%), followed by moderately differentiated 15 cases (37.5%) and poorly differentiated 7 cases (17.5%). whereas in lscc the predominant grade was moderately differentiated 17 cases (42.5%), followed by well differentiated 12 (30.0%)and poorly differentiated 11 cases (27.5%). . in skin the well differentiated degree was so high 24 cases (60.0%) compared to moderately differentiated 11 (27.5%) and poorly differentiated 5 cases (12.5%). the pattern of expression of nrp 1 in the present study, was cytoplasmic and/or membranous as shown in figures (1),(2) and (3). as shown in table(3),105 cases were positively stained with nrp1 ab in the three types of cancers (87.5%) while 15 cases were negative (12.5%).the immunostaining was distributed equally between score 2 and 3 in oral scc (14cases) (35.5%) for each , and for lscc (17 cases) (42.5%).in skin scc the positive cases were (33)(82.5%).the predominant score was 3 (16 cases) (40%), followed by score 2 (11cases) (27.5%).the mean rank of median expression of scores for the three types were (57.4%), (65.9%) and (58.2%) respectively with a non-significant difference among them.tables (4,5 and6) showed that, the median score of nrp1was the lowest among subjects with grade i tumor and increased with increasing tumor grade to reach its highest median score among those with grade iii (poorly differentiated) in oscc, lscc and skin scc with significant correlation (p=0.009),(p=0.002) and (p=0.007) respectively. discussion statistical analysis of the study results revealed high percentage of nrp1 expression in oscc, lscc and skin scc (87.5%), (92.5%) and (82.5%) respectively which was consistent with previous evidenced proved results which consider nrp1 being widely up-regulated in neoplastic epithelium compared to normal epithelium or to neoplasms which are not of epithelial origin, like neuroblastomas , glioblatomas and melanomas (13). ding et al, (2014) had found no significant correlation of nrp1 expression with both age or gender (14), which is in contrast to study results that showed a significant correlation with oscc and gender, but no obvious relationship with age.a significant correlation with degree of differentiation was reported in previous researches (14 & 15) and that is similar to the present results (p=0.009) in oscc, (p=0.002) in lscc and (p=0.007) in skin scc. this positive correlation with histopathological gradeswas proved by one study which stated that angiogenesis in well and moderate differentiated scc is more than that in non-cancerous epithelium , and in poorly differentiated scc angiogenesis is much more intense than in well differentiated scc (16). the expression of nrp-1 to vegfr2 increases in association with tumor grade (17),and overexpression of nrp1 is associated with intensive vascularization (18) . in head and neck scc, vascular endothelial growth factor a (vegfa) is the main mediator of angiogenesis (19). vegf-a bind to numerous receptors including kdr, flt1 and nrp1 and induce angiogenesis by activation of kinase cascade which include ras as well as mapk ( 20). it has been found that in lining epithelium nrp-1 affects tgf-β1 signaling. tgfβ1 is a major j bagh college dentistry vol. 29(1), march 2017 variation oral diagnosis 65 control of epithelial mesenchymal transition (emt). epithelial mesenchymal transitionpromoting progression and invasion of malignant cell into surrounding tissue via molecular changes to epithelial cells which promote cellcell adhesive disfunction(21). so nrp-1 act as an enhancer of emt process in hnscc process (22). additionally, nrp1 serves as a regulator of hedgehog (hh) signal (23) and target for shh signaling (24). so nrp1 is important for mediating vegf effects on cancer cells (25). in skin scc it has been found that vegf ligand increases in epidermis with squamous cell carcinomas or when exposed to ultra violet b (uvb) irradiation. over-expression of vegf in low grade scc rises their growth rate as well invasiveness (15). skin cancer cells expressed both endogenous vegf-a as well as nrp-1 (26),where nrps which are co-receptor for vegf, increasing their activity (27). binding of vegf-a to nrp-1 promoting signaling such as the mapk pathway and contribute to progression of tumor (28). vegf appeared to act as an internal autocrine survival mediator in nrps positive cancer cells (13).the pattern of expression of nrp 1 in the present study, was cytoplasmic and/or membranous and this in agreement with most previous studies such as yacoub et al in prostatic cancer (29); ding et al in lung cancer (14). xu et al, in nasopharnx (30). this is because nrp1 receptors are mainly found in cytoplasm and membranes of tumor cells (31). nrp1 have a large extra cellular membrane domain, short transmembrane domain and small cytoplasmic not enzymatic domain (32). in addition a naturally occurring soluble nrp-1protein (snrp-1), that containing only part of the extra cellular domain, generated via alternative splicing of nrp-1 gene (11). in conclusion, the absence of significance that relating to biological behavior variation among the three types (p=0.44) , despite high expression observed suggesting that angiogenesis plays a crucial and similar role in carcinogenesis in cancer of epithelial in origin, and its positive correlation with degree of differentiation speculating that nrp1 can predict prognosis in oscc, lscc and skin scc. the prognostic significance of the expression needs to be clarified in further studies. table 1: frequency distribution of the 3 study groups by age and gender. study group oral scc laryngeal scc skin scc n % n % n % age group (years) <50 11 27.5 3 7.5 13 32.5 50-69 20 50.0 32 80.0 19 47.5 70+ 9 22.5 5 12.5 8 20.0 total 40 100.0 40 100.0 40 100.0 gender female 19 47.5 11 27.5 13 32.5 male 21 52.5 29 72.5 27 67.5 total 40 100.0 40 100.0 40 100.0 table 2: frequency distribution of the 3 study groups by tumor grade study group oral scc laryngeal scc skin scc n % n % n % tumor grade well differentiated 18 45.0 12 30.0 24 60.0 moderately differentiated 15 37.5 17 42.5 11 27.5 poorly differentiated 7 17.5 11 27.5 5 12.5 total 40 100.0 40 100.0 40 100.0 j bagh college dentistry vol. 29(1), march 2017 variation oral diagnosis 66 table 3: the difference in median score category of nrp1 among the 3 study groups. table 4: the difference in median score category of selected nrp1 marker between the 3 tumor grades among cases with oral scc. tumor grade well differentiated moderately differentiated poorly differentiated oral scc n % n % n % p nrp1 score 0.012 negative (0%) 2 11.1 3 20.0 0 0.0 score-1 (1-29%) 4 22.2 3 20.0 0 0.0 score-2 (30-60%) 10 55.6 3 20.0 1 14.3 score-3 (61%+) 2 11.1 6 40.0 6 85.7 total 18 100.0 15 100.0 7 100.0 median score-2 score-2 score-3 mean rank 16.9 19.7 31.5 r=0.41 p=0.009 table 5: the difference in median score category of selected nrp1 marker between the 3 tumor grades among cases with laryngeal scc. tumor grade well differentiated moderately differentiated poorly differentiated laryngeal scc n % n % n % p nrp1 score 0.012 negative (0%) 2 16.7 1 5.9 0 0.0 score-1 (1-29%) 2 16.7 1 5.9 0 0.0 score-2 (30-60%) 6 50.0 8 47.1 3 27.3 score-3 (61%+) 2 16.7 7 41.2 8 72.7 total 12 100.0 17 100.0 11 100.0 median score-2 score-2 score-3 mean rank 14 20.6 27.4 r=0.477 p=0.002 study group oral scc laryngeal scc skin scc n % n % n % p nrp1 score 0.44[n s] negative (0%) 5 12.5 3 7.5 7 17.5 score-1 (1-29%) 7 17.5 3 7.5 6 15.0 score-2 (30-60%) 14 35.0 17 42.5 11 27.5 score-3 (61%+) 14 35.0 17 42.5 16 40.0 total 40 100.0 40 100.0 40 100.0 median score-2 (30-60%) score-2 (30-60%) score-2 (30-60%) mean rank 57.4 65.9 58.2 p (mann-whitney) for difference between: laryngeal scc x oral scc = 0.23[ns] skin scc x oral scc = 0.96[ns] skin scc x laryngeal scc = 0.31[ns] j bagh college dentistry vol. 29(1), march 2017 variation oral diagnosis 67 table 6: the difference in median score category of selected nrp1 marker between the 3 tumor grades among cases with skin scc. tumor grade well differentiated moderately differentiated poorly differentiated skin scc n % n % n % p nrp1 score 0.016 negative (0%) 4 16.7 3 27.3 0 0.0 score-1 (1-29%) 6 25.0 0 0.0 0 0.0 score-2 (30-60%) 9 37.5 2 18.2 0 0.0 score-3 (61%+) 5 20.8 6 54.5 5 100.0 total 24 100.0 11 100.0 5 100.0 median score-2 score-3 score-3 mean rank 17.2 22.3 32.5 r=0.422 p=0.007 figure (1): membranous and cytoplasmic figure (2):membranous and cytoplasmic nrp1 expression in oscc (x40) nrp1expression in lscc (x20) figure (3): membranous and cytoplasmic nrp1 expression in skin scc (x40) j bagh college dentistry vol. 29(1), march 2017 variation oral diagnosis 68 refferences 1. 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62( 9): 619-631. صالملخ ةالمقدم (nrp1) 1يعتبر النيروبليين في الخاليا العصبية انزيم اميني حركي وظيفته الرئيسية تحفيز عامل نمو الخاليا المبطنة لألوعية الدموية . أكتشف ألول مرة مستقبل مساعد حديث وليس ن للتعرف ن المرض. ان الهدف من هذه الدراسة كاالمهاجرة. لقد وجد بان هذا المستقبل يظهر عاليا وبنسب متفاوتة حسب نوع السرطان وان ظهوره يعتبر مؤشرا على مراحل متقدمة م على تباين ونسب ظهور هذا المستقبل بين ثالثة انواع من السرطان من اصل واحد ولكن من مواقع مختلفة. المواد وطرق العمل بعون عينة لكل اليا الحرشفية للفم والحنجرة والجلد وبواقع ارتضمنت الدراسة استخدام مائة وعشرون عينة محفوظة بمادة الفورمالين ومطمورة بشمع البارافين تشمل سرطان الخ في جميع الحاالت السرطانية. وتم مقارنة النتائج حسب العمر والجنس ودرجة (nrp1)مرض. وحللت الدراسة بطريقة الظهور المناعي النسيجي الكيميائي وباستخدام صبغة ال التمايز النسيجي المرضي. النتائج المناعي النسيجي الكيميائي باستخدام صبغة كشف التحليل (nrp1) ( 29.9(, )%8..5ان نسبة ظهور الصبغة في سرطان الخاليا الحرشفية لكل من الفم والحنجرة والجلد كانت% ) ( على التوالي. مع عدم وجود تفاوت كبير في ظهور الصبغة بينهم%59.8و) )4.00 (p= مع درجات التمايز النسيجيولكن ظهورها كان على عالقة احصائية قوية ) 4.449 ,(p= (4.442 (p= .4.44و ) p=.على التوالي ) األستنتاج (angiogenesis)عملية تكون اوعية دموية جديدة تعتبر جوهرية واساسية في االنواع الثالثة من سرطان الخالية الحرشفية . وأن صبغة (nrp1) ترتبط بشكل كبير مع درجة يمكن ان تعتمد للتكهن بمدى تطور المرض من حيث استفحال السرطان وانتشاره من عدمه في المستقبل. ع الثالثة, لذاالتمايز النسيجي لالنوا http://www.ncbi.nlm.nih.gov/pubmed/16251410 http://www.ncbi.nlm.nih.gov/pubmed/16251410 munad f.doc j bagh college dentistry vol. 25(4), december 2013 the effect of orthodontic pedodontics, orthodontics and preventive dentistry114 the effect of orthodontic relapse on the proliferation of fibroblast and epithelial rests of malassez in periodontal ligament of rat molars (a histopathological study) munad j. al-duliamy, b.d.s., m.sc. (1) ghada m. mustafa, b.d.s., m.sc. (2) omar a. kader, b.d.s., m.sc. (3) abstract background: relapse of previously moved teeth, is major clinical problem in orthodontics with respect to the goals of successful treatment. this study investigated the effect of orthodontic relapse on the proliferation of fibroblast and epithelial rests of malassez cells in periodontal ligament of rat molars. materials and methods: sixteen ten-weekold male wister rats were randomly divided into four groups composed of four animals each: group i received no orthodontic force (control). in both group ii and group iii, uniform standardized expansive springs were used for moving the maxillary first molars buccally for periods of one and three weeks respectively. the spring initially generated an average expansive force of 20 g on each side. in group iv the springs were left for three weeks, until the maxillary first molars moved buccally, after that the springs were removed and the animals were scarified after three weeks of relapse tooth movement. after the humanly scarification of animals, each maxilla in all groups was dissected into two halves each half including the three maxillary molars and processed for histological examination. the number of both fibroblast and erm cells in each cluster was counted in the pdl of the pressure side of the mesio-buccal roots of the maxillary right and left first molars in all groups and the surface areas of the erm clusters were also measured in all groups. results: the number of fibroblast was significantly increased at the end of active movement (group iii) and significantly very highly increased during the relapse period (group iv). regarding the erm cells there were statistically significant increase in both the number of cells in each erm cluster and the surface areas of the erm clusters in group iii and highly significant increase in group iv, while group ii showed no significant differences regarding all measurements. conclusions: it was concluded that fibroblast and erm cells may play an important role during orthodontic relapse keywords: orthodontic relapse, fibroblast, epithelial cell rest of malassez, rat. (j bagh coll dentistry 2013; 25(4):114119). introduction in orthodontics, relapse is a concept that is antagonistic to stability and can be defined as the tendency of treated teeth to return to their original position. relapse in its various manifestations remains a phenomenon whose etiologies are still not well determined, unproved, and thus highly controversial. its etiology is multifactorial. the major causative factor is the considerable residual forces remain in the tissues of the periodontium after teeth movements which tend to return the teeth into their original position (1). studies have shown that no means are yet available to help the relapse prediction following orthodontic treatment; therefore permanent retention could be the most reliable solution (2). tissue remodeling in orthodontics is mediated by a variety of cells. teeth can be moved because cells around their roots are enticed by the mechanical force to remodel the tissues around them. numerous studies have investigated the response of the dental supporting tissues to orthodontic force. (1)assistant lecturer. department of orthodontics. college of dentistry. al-mustansiria university. (2)professor. department of prosthodontics. college of dentistry. al-mustansiria university. (3)assistant lecturer. department of oral diagnosis. college of dentistry. university of baghdad. these studies attempted mainly to analyze the histological changes in paradental tissues during orthodontic tooth movement. those studies showed extensive cellular activities in the mechanically stressed pdl involving fibroblasts, endothelial cells, osteoblasts, osteocytes, and endosteal cells (3). to date, no attempt has been made to describe in detail histological changes during relapse and only a few studies have been published about the biological mechanisms behind the relapse process (4). fibroblasts are the principal cells of the periodontal ligament. they are aligned along the general direction of the fiber bundles and extend cytoplasmic processes that wrap around them. they are large cells responsible of protein synthesis and secretion. one of the main factors that avoid relapse is the rate of turnover or renewal of the periodontal collagen fiber turnover (4) which appears to be regulated by fibroblasts (5). therefore the periodontal fibroblasts may play a crucial role during orthodontic relapse. epithelial cell rests of malassez (erm) are development residues of hertwig’s root sheath, which is a double-layer structure made of epithelial cells that is present around the tooth root. in the periodontal ligament (pdl) of mature teeth, the epithelial cells form strands close to and j bagh college dentistry vol. 25(4), december 2013 the effect of orthodontic pedodontics, orthodontics and preventive dentistry115 along the cementum (6,7). it was long believed that erm comprised latent or quiescent cells devoid of structure and function, often associated with the genesis of cysts and tumors. however, these epithelial periodontal components are active, have a fundamental role in root development, root integrity even during orthodontic movement, protect against root resorption, and are involved in reparative and regenerative functions of the pulp and periodontal tissues including apexogenesis and periodontal healing. compiling evidence suggests that erm may be the source of cementoblasts (8-10). many investigations on the developmental and evolutionary biology of erm with several clinical reports were supported a concept of erm as a regulator of periodontal ligament biology as it relates to width, blood vessel homeostasis, and cementogenesis, as well as protection against resorption and ankylosis . there is evidence that erm cells are stimulated during orthodontic tooth movement (9, 11). no study examined the effect of orthodontic relapse on the fibroblast and erm activities. therefore the purpose of this study was to investigate the behavior and activity of these periodontal ligament cells against orthodontic relapse of rat molars. as a more knowledge about the effects of orthodontic relapse on discrete cell populations could strengthen the rationale of retention programs and thereby improve post orthodontic retention phase. furthermore this study is an attempt to provide a base line for later histological, immunohistochemical and biochemical investigations on the fate of fibroblast and the erm of the rat molars under different phases of orthodontic tooth movement and to serve as a part of a broader study of the biology of orthodontic relapse in accordance to the action of these cells. materials and methods sample sixteen ten-weekold male wister rats weighing 250300 g were purchased from the animal house of the national center of drug control and research/ baghdadiraq and used as experimental animals. the animals were treated ethically according to the guidelines of the animal care staff at the national center for drug control and research / baghdad–iraq. the samples were randomly divided into four groups composed of four animals each: » group i (gi): no orthodontic force (control). » group ii (gii): 7 days of orthodontic tooth movement. » group iii (giii): 21 days of orthodontic tooth movement. » group iv (giv): 21 days after release of orthodontic force. methods tooth movements were performed according to the methods used in a previous study by alduliamy (12). the rats in the control group receive no orthodontic force. in both (gii) and (giii), uniform standardized expansive springs were used for moving the maxillary first molars buccally (figure1). the spring initially generated an average expansive force of 20 g on each side, and it exerted as continuous force of intermediate magnitude for molars expansion. in (giv) the springs were left for three weeks, until the maxillary first molars moved buccally, after that the sprigs were removed and the animals were scarified after three weeks of relapse tooth movement. histology after the humanly scarification of animals under general anesthesia, each maxilla was dissected into two halves each half including the three maxillary molars. the specimens were then dehydrated and embedded in paraffin. paraffin blocks were cut coronally at the area of maxillary first molar in 5 μ m thick serial sections with a microtome and mounted on microscope slides. the sections were stained with hematoxylin and eosin. the mesio-buccal roots of the maxillary right and left first molars of all groups were identified and examined. the root was divided into buccal and palatal sides, based on the mesiodistal axis of the root. evaluation of the fibroblast and erm cells numbers in clusters and the surface areas of these clusters was performed on the root surface of the pressure side of the mesiobuccal roots in all groups and in both halves of rat maxilla. the hematoxylin and eosin stained slides were examined by digital light microscopy to identify the fibroblast and erm cells based on their morphology. fibroblast was observed as elongated cell with little cytoplasm and dark staining flatted nucleus (5). according to a method described previously (13), the erm cells in their characteristic clusters were counted and the surface areas of the clusters were measured. all measurements have been done at 40x magnifications by using the inbuilt image processing software of digital microscope (micros crocus ii mcx100lcd produktions und handelsgmbh) that was fed directly to a tv monitor with a real time live camera. j bagh college dentistry vol. 25(4), december 2013 the effect of orthodontic pedodontics, orthodontics and preventive dentistry116 measurements were blindly performed by two operators, after inter-operator calibration. the final count was designated to be the mean of these counts. values for four sections, selected at five section intervals, were averaged for each animal. statistical analyses the mean numbers of fibroblast cells, erm cells in clusters and the surface areas of these clusters on the pressure side of the mesio-buccal roots of the maxillary right and left first molars in all groups were statistically analyzed and compared with one-way analysis of variance (anova) and least significant difference (lsd) test spss software. in the statistical evaluation, the following levels of significance were used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 * significant 0.01 ≥ p > 0.001 ** highly significant p ≤ 0.001 *** very highly significant results fibroblast cells from observations on table 1, it is found that the highest mean value of the fibroblast cell number was found in group iv while the lowest mean value of fibroblast cell number was found in group i. according to lsd (table 2), there were no statistically significant difference between group i and group ii in number of fibroblast cell, highly statistically significant difference between group i and group iii and a very highly significant difference between group i and group iv. erm cells typical appearance of the erm was seen under digital light microscopy; they appeared in the form of clusters. the clusters consisted of numerous epithelial cells. these numerous epithelial cells showed oval or round cluster forms, and some cells showed a strand form. they were localized near the root surface rather than near the alveolar bone (figure 2). from observations in table 1, it was found that, the highest mean value of the erm cell numbers were in group iv. while the lowest mean value of the erm cell numbers were in group i. on the other hand, the highest mean value of the surface areas of clusters were in group iv. while the lowest mean value of the surface areas of clusters were in group i. according to lsd (table 2), there were no statistically significant difference between group i and group ii in both the erm cell numbers and the surface areas of clusters and statistically significant difference between group i and group iii in both measurements and a very highly significant difference between group i and group iv. as there were a significant increased in number and cluster size of epithelial rests in areas of compression in group iii and group iv (figure 3). discussion a rat model widely used in previous studies was also used in this experiment. according to vignery and baron (14), tran van et al. (15), baron et al. (16) and ren et al. (17), rat model has many similarities to the supporting structures in human teeth and it is generally good model to study orthodontic tooth movement because of its higher remodeling rate. in the present study the pressure side in group ii and iii represents the buccal side of the mesiobuccal roots of the maxillary right and left first molars while in group iv after the removal of the expansive force it represents the palatal side of the mesio-buccal roots of the maxillary right and left first molars as the pressure here was as a result of rebound of the compressed periodontal ligament. fibroblast cells at the pressure side of the mesio-buccal roots of the maxillary right and left first molars of group ii, iii and iv, the fibers of the pdl were compressed and between these fibers the fibroblast cell were arranged (figure 2), this is in accordance with krishnan and davidovitch (4). in comparison with group i (control) there was no statistical differences in the number of fibroblast cell in group ii. one possible explanation for this is the fact that this time intervals are associated with inflammatory responses to forces. furthermore according to rygh (18) and brudvik and rygh (19), these early stages are associated local tissue necrosis of the compressed regions when no cells are present. it is to be expected that it takes time for these regions of the pdl to reorganize. regarding group iii, there was increase in the numbers of fibroblast cells. these finding confirmed by the result of von b€ohl et al. (20) which reported that after the removal of the necrotic areas, the cells start the bone remodeling process. regarding the sample in group iv, after release of the expansive force, the very highly significant differences in the number of fibroblast cell in this group may be explained by the remodeling of the extracellular matrix which play j bagh college dentistry vol. 25(4), december 2013 the effect of orthodontic pedodontics, orthodontics and preventive dentistry117 an integral part in tooth movement in response to the orthodontic relapse force and this matrix mainly produced by fibroblast cells according to krishnan and davidovitch (4). erm cells in the present study of rats, typical cluster of the erm were seen in the compression area in all the experimental groups very near the root surface in round form and strands arrangement this is in accordance with becktor et al. (21). the reappearance of the erm in the compressed areas is explained by the cells’ ability to migrate from the surrounding undamaged areas of the pdl. in comparison with group i (control) the erm cell numbers and surface areas of clusters showed no statistical differences in group ii ; this may be explained by the result of rygh (18) and brudvik and rygh (19), regarding the initial phase after force application which accompany local tissue necrosis with cell free zone. the increased numbers of erm and surface areas of clusters in group iii where periodontal remodeling is accelerated suggest that these cells might be involved in remodeling activities during orthodontic tooth movement this is in consistent with the results of talic et al. (13) and consolaro and consolaro (9). concerning the increased numbers of erm and surface areas of clusters there was evidence that they were very highly significant in group iv. this finding means that, relapse movement stimulates erm cell proliferation. the histological observations, along with previous findings (9) showed that orthodontic tooth movement stimulates erm cell proliferation. on the other hand the present study observed for the first time that erm could involve at least in part, in regulating tissue reorganization around the orthodontically moved teeth during retention phase after orthodontic tooth movement. these finding suggesting that the erm may play a crucial role in enhancing post orthodontic stability which is most difficult elements of clinical orthodontic practice. future studies are needed from a biomolecular basis and cell biological approach to clarify the specific role of the erm in tissue reorganization during retention periods particularly collagen turnover and production of different mediators for tissue remodeling. as a conclusion; it has been shown in this study that, there were highly significant increase in the numbers of fibroblast cells, numbers of erm cells in clusters and the surface areas of these clusters during relapse tooth movement. this exaggerated response of these periodontal ligament cells indicate that the fibroblast and the erm cells may play an important role during orthodontic relapse. references 1. melrose c, millett dt. toward a perspective on orthodontic retention? am j orthod dentofac orthop 1998; 113: 507–14. 2. lópez-areal l, gandía jl. relapse of incisor crowding: a visit to the prince of salina. med oral patol oral cir bucal 2013; 18 (2): 356-61. 3. krishnan v, davidovitch z. cellular, molecular, and tissue-level reactions to orthodontic force. am j orthod dentofac orthop 2006; 129(4): 469.e1-32. 4. krishnan v, davidovitch z. biological mechanisms of tooth movement. indianapolis: wileyblackwell; 2009. pp. 201-12. 5. nanci a. ten cate’s oral histology; development, structure, and function. 17th ed. mosby: elsevier health sciences; 2008. pp. 259. 6. diekwisch tg. the developmental biology of cementum. int j dev biol 2001; 45: 695–706. 7. rincon jc, young wg, bartold pm. the epithelial cell rests of malassez– role in periodontal regeneration? j periodontal res 2006; 41: 245–52. 8. bosshardt dd. are cementoblasts a subpopulation of osteoblasts or a unique phenotype? j dent res 2005; 84: 390. 9. consolaro a, consolaro mfm-o. erm functions, egf and orthodontic movement or why doesn't orthodontic movement cause alveolodental ankylosis? dental press j orthod 2010; 15(2): 24-32. 10. keinan d, cohen re. the significance of epithelial rests of malassez in the periodontal ligament. j endod 2013; 39(5): 582-7. 11. luan x, ito y, diekwisch tg. evolution and development of hertwig's epithelial root sheath. dev dyn 2006; 235:1167-80. 12. al-duliamy mj. enhancement of orthodontic anchorage and retention by local injection of strontium (an experimental study in rats). a master thesis. department of orthodontics, college of dentistry, university of baghdad, 2011. 13. talic nf, evans ca, daniel jc, zaki aem. proliferation of epithelial rest of malassez during experimental tooth movement. am j orthod dentofac orthop 2003; 123(5): 527-33. 14. vignery a, baron r. dynamic histomorphometry of alveolar bone remodeling in the adult rat. anat rec 1980; 196: 191-200. 15. tran van pt, vignery a, baron r. cellular kinetics of the bone remodeling sequence in the rat. anat rec 1982; 202: 445-51. 16. baron r, tross r, vignery a. evidence of sequential remodeling in rat trabecular bone: morphology, dynamic histomorphometry, and changes during skeletal maturation. anat rec 1984; 208:137-45. 17. ren y, malth jc, kuijpers-jagtman am. the rat as a model for orthodontic tooth movement--a critical review and a proposed solution. eur j orthod 2004; 26: 483-90. 18. rygh p. ultrastructural changes in pressure zones of human periodontium incident to orthodontic tooth movement. acta odontol scand 1973; 31(2):109-22. j bagh college dentistry vol. 25(4), december 2013 the effect of orthodontic pedodontics, orthodontics and preventive dentistry118 19. brudvik p, rygh p. the initial phase of orthodontic root resorption incident to local compression of the periodontal ligament. eur j orthod 1993; 15(4): 249– 263. 20. von b€ohl m, maltha j, von den hoff h, kuijpersjagtman am. changes in the periodontal ligament after experimental tooth movement using high and low continuous forces in beagle dogs. angle orthod 2004; 74: 16-25. (ivsl). 21. becktor kb, nolting d, becktor jp, kjaer i. immunohistochemical localization of epithelial rests of malassez in human periodontal membrane. eur j orthod 2007; 29:350-353. (ivsl). table 1. descriptive statistics and groups’ comparisons regarding fibroblast and epithelial cells numbers and cluster surface area of the epithelial cells groups fibroblast cells number epithelial rests cell number clusters surface area (µm2) mean s.d. mean s.d. mean s.d. group i 8.125 0.834 5.125 0.834 2.956 0.659 group ii 8.125 0.834 5.125 0.834 2.923 0.634 group iii 9.250 0.886 6.125 0.641 3.583 0.350 group iv 11.625 0.744 6.875 0.641 5.681 0.866 anova 31.889 9.651 33.656 p-value 0.000 *** 0.000 *** 0.000 *** table 2. lsd test after anova test parameters groups mean difference p-value fibroblast cells number i ii 0 1 (ns) iii -1.125 0.011 * iv -3.50 0.000 *** ii iii -1.125 0.011 * iv -3.50 0.000 *** iii iv -2.375 0.000 *** epithelial rests cell number i ii 0 1 (ns) iii -1 0.015 * iv -1.75 0.000 *** ii iii -0.921 0.023 * iv -1.75 0.000 *** iii iv -0.75 0.073 (ns) clusters surface area (µm2) i ii -0.033 0.902 (ns) iii -0.627 0.036 * iv -2.725 0.000 *** ii iii -0.66 0.024 * iv -2.758 0.000 *** iii iv -2.098 0.000 *** j bagh college dentistry vol. 25(4), december 2013 the effect of orthodontic pedodontics, orthodontics and preventive dentistry119 figure 1: the spring in its place in rat maxilla. figure 2:typical clusters of epithelial rests (er) in compression side of pdl very near root (r) surface, alveolar bone(a), fibroblast cell (f). a: round cluster. b: strand form,(h & e staining × 40). figure 3: clusters of epithelial rests (er) in pdl near root surface (r) and fibroblast cell (f) in a: group i (control) b: increased number of fibroblast and epithelial rests cell and cluster size in group iii and in c: group iv (h & e staining × 40) 4. maha f.doc j bagh college dentistry vol. 25(1), march 2013 the surface roughness restorative dentistry 21 the surface roughness of new fluoride releasing material after using three polishing protocols and storage in artificial saliva maha a. habeeb, b.d.s., m.sc. (1) abstract background: prophylaxis methods are used to mechanically remove plaque and stain from tooth surfaces; such methods give rise to loss of superficial structure and roughen the surface of composites as a result of their abrasive action. this study was done to assess the effect of three polishing systems on surface texture of new anterior composites after storage in artificial saliva. materials and methods: a total of 40 giomer and tetric®n-ceram composite discs of 12 mm internal diameter and 3mm height were prepared using a specially designed cylindrical mold and were stored in artificial saliva for one month and then samples were divided into four groups according to surface treatment: group a (control group):10 specimens received no surface polish and were subdivided into a1 (giomer) and a2 (tetric®n-ceram). group b: 10 specimens received polishing with air polishing devise (apd) and were subdivided into b1 (giomer) and b2 (tetric®n-ceram). group c: 10 specimens received polishing with pumice and brush and were subdivided into c1 (giomer) and c2 (tetric®n-ceram). group d: 10 specimens were polished with pumice and rubber cup and were subdivided into d1 (giomer) and d2 (tetric®n-ceram). testing was done by means of profilometer and statistically analyzed using analysis of variance test (anova), lsd and student t-test. also samples were photographed by special orthoplane camera using light polarizing microscope. results: the results showed a highly statistical significant difference in surface roughness among giomer subgroups p<0.05. also there was a highly significant difference p<0.05 when comparing tetric subgroups according to type of surface treatment. furthermore there was non-significant difference p>0.05 between groups according to the type of restorative material used. conclusion: the use of prophylactic surface treatment significantly increased giomer and tetric ceram surface roughness and the use of rotating brush has shown the roughest surface among all other types of prophylactic protocols also giomer had shown more surface roughness than tetric ceram although the difference was not significant. key words: surface roughness, fluoride, artificial saliva. (j bagh coll dentistry 2013; 25(1):21-26). introduction the last decade has witnessed significant improvements in the physical and mechanical properties, esthetics, and durability of resin composite materials for direct restorations (1). one feature that has enhanced resin-based restorative materials is fluoride release; several fluoride containing materials have been developed, such as resin-modified glass ionomer, compomer, giomer and fluoride-containing resinbased composite. giomers has been introduced for cervical restorations, these light-cured materials incorporate glass-ionomer fillers into the resin matrix. giomers bear the advantages of both composite resins and glass-ionomers; they have excellent esthetics, good polishability, and biocompatibility and also render glass-ionomer properties, including fluoride release and fluoride recharge potential (2). proper seal against bacterial microleakage and minimal mechanical and chemical irritation of the pulp are other advantages of giomers (3). (1)assistant lecturer/department of conservative dentistry/ college of dentistry, university of baghdad. long-term clinical studies have reported satisfactory visual texture and surface roughness of giomer restorations. there is little information available about the influence of prophylaxis procedures on giomers (4). prophylaxis methods are aimed at mechanical removal of stains and plaque from tooth surfaces, especially in the vicinity of gingival tissues. these methods are factors involved in damaging and even destroying the surface of cervical restorations (5). use of pumice and rubber cup is the most common method to remove plaque and stains. recently, the use of air-powder polishing device (apd) has gained popularity among dentists (6). in previous studies influence of different prophylaxis procedures on surface roughness of different types of composite resins and glass-ionomers has been investigated and it has been reported that the effect of prophylaxis treatments depends on the material (7). the purpose of this in vitro study is to determine the influence of three types of polishing systems on the surface roughness and surface morphology of new fluoride releasing aesthetic material known as giomer and nano hybrid composite tetric n ceram after one month storage in artificial saliva. j bagh college dentistry vol. 25(1), march 2013 the surface roughness restorative dentistry 22 materials and methods forty specimens of giomer a3 (shofu, kyoto, japan) and tetric n ceram shade a3 (ivoclar vivvadent) composite discs of 12 mm internal diameter and 3mm height were prepared using a specially designed cylindrical mold (8). the composite were inserted and pressed into the mold until they were overfilled, the material then were covered with a transparent matrix strip and glass microscopic slide to extrude excess material and flatten the surface and to reduce voids at the surface. specimens were then polymerized according to manufacturers’ instructions with a conventional quartz halogen light-curing unit (ydl, hangzhou yinya new materials co., china). then all specimens were stored in artificial saliva in a constant temperature incubator (memmert,germany) at 37 c° for one month(9). the forty specimens were devided into four groups (a, b, c and d) and each of these main groups was further subdivided into two subgroups five for each type of composite (giomer and tetric n ceram). for group a (control group), no surface treatment was applied, for group b the surface was treated with an air-powder polishing device (air-flow handy sms dent, malaysia). the alignment of the tip was perpendicular to surface for 12 seconds and 10 mm distance. in group c a rotating brush (tpc industry, usa) with pumice was used for 12 seconds using contra-angle handpiece (hk, roc) at 2000 rpm. in group d the same procedure was applied but instead we used a rubber cub ( products co, china) for the same period of time. (10) in groups b, c and d subsequent to the prophylaxis procedures the samples were rinsed with deionized distilled water for 10 minutes. after rinsing, the average value of surface roughness of all specimens were measured by means of profilometer (talysurf 4, taylor hobson, uk) horizontal magnification= 4x, vertical magnification= 500x to measure the roughness (ra) on composite surface the profilometer measured each specimen at 3 areas in various locations with a maximum travelling distance of 11 mm. the average value was recorded. samples were photographed by special orthoplane camera using light polarizing microscope to evaluate the surface alteration before and after prophylactic procedures using magnification power of 50x. results the mean, standard deviation and standard error of surface roughness in µm with minimum and maximum value of each group are illustrated in (table 1) and (fig.1) subgroup c1 (brush group) showed the highest mean of surface roughness (1.78±0.148) while subgroup a2 (control group) showed the lowest mean of surface roughness (1.1±0.245). the statistical analysis of data using anova test revealed that there was a highly significant difference among giomer subgroups (a1 control, b1 apd, c1 brush and d1 rubber cub) p<0.05 (table 2). also there was a highly significant difference when comparing tetric subgroups (a2 control, b2 apd, c2 brush and d2 rubber cub) p<0.05 (table 4). the source of differences was further investigated using lsd test. these investigations had shown that there was a significant difference among all giomer subgroups except for subgroups (a1 control, d1rubber cup), and (b1 apd, c1 brush) which had shown a non statistical significant difference (p>0.05) in mean surface roughness according to the method of surface treatment (table 3). by the use of lsd there was a significant difference (p<0.05) in mean surface roughness between tetric ceram subgroups except between (b2 apd, c2 brush) and between (c2 brush and d2 rubber cup) subgroups which had shown a non significant difference p>0.05 table (5). further analysis between subgroups of the same group according to the type of restorative material using t-test was needed to show where the significance had occurred between giomer and tetric subgroups, table (6). analysis by t-test had shown a non significant difference p>0.05 in mean surface roughness between all the mentioned subgroups. discussion the quality of surface is an important parameter that influences the behavior of dental restorations in the oral environment in different ways. hygiene maintenance therapy is an integral part of restorative and periodontal treatment. the removal of stains and plaque from all accessible tooth surfaces is a routine part of the maintenance appointment (11). the conventional rubber cup prophylaxis and air-powder polishing system are both effective professional techniques for plaque and stain removal. since its introduction to the dental marketplace in 1977, air-powder polishing systems have been effective at removing stains and plaque, previous studies on various types of composite resins and glass-ionomer have reported that the apd produces a rougher surface j bagh college dentistry vol. 25(1), march 2013 the surface roughness restorative dentistry 23 compared to the pumice and rubber cup technique (12). the surface roughness (ra) refers to fine irregularities of the surface texture that usually result from the action of the production process or material conditions and is measured in micrometers (μm). this parameter describes the overall roughness of the surface and can be defined as the arithmetic average value of all absolute distances of the roughness profile from the center line within the measuring length. the roughness parameters are dependent on several factors such as filler size, percentage of surface area occupied by filler particles, hardness, degree of conversion of polymer to resin matrix and filler/matrix interaction, as well as stability of silane coupling agent (13). tetric n ceram composite resin and a giomer were chosen to be used in this study because these aesthetic restorative materials are commonly used in cervical areas, in variably more susceptible to the action of prophylactic treatments. the results of the present study indicated that prophylaxis treatments of giomer and tetric subgroups resulted in a highly significant increase in surface roughness in comparison with the control group for both restorative materials. pumice with brush group showed a dramatic increase in surface roughness followed by apd, and pumice with rubber cup. these results agree with previous studies on giomer in which there were a significant increase in surface roughness between groups treated by prophylactic systems (14). the higher surface roughness values in the pumice-with brush group might be attributed to the abrasive feature of rotating brush (15). in the present study, the use of apd resulted in increase in roughness when compared to the use of rubber cup in giomer and tetric samples, which confirms the results of previous studies conducted on composite resins and glass-ionomer. it seems that high pressure of air and water in apd is strong enough to degrade the filler-resin bond joined together through silane. therefore, the fillers from the superficial layer are debonded. furthermore, the possibility of the abrasion of filler phase of resin materials by powder components of apd has been reported (16). the results of the present study showed that surface roughness in all the giomer groups was non significantly higher than that in the corresponding composite resin groups. differences in surface roughness between tetric ceram and giomer might be attributed to different chemical compositions of the two materials. previous studies have demonstrated the effect of chemical composition of materials on surface roughness. it has been reported that giomer releases more fluoride compared to composite resin because it contains fluoridated glass fillers with glass-ionomer matrix. this matrix has a high content of fluoride complex, and water easily penetrates into it, which results in the release of large quantities of fluoride and this will lead to increase porosity and surface roughness. previous studies have reported greater fluoride release from giomers in comparison to tetric n ceram (17). the specimens in the present study were placed in artificial saliva for one month and any loose filler particles from polished composite surface present were probably dislodged forming voids and individual glass particles protruding, so stresses could build up in the glass particles-resin matrix interfaces, and early immersion into artificial saliva may help to propagate the cracks. tetric resin composite contains 3 fillers, which are 0.02 μm nanofiller, 0.04 μm barium glass filler and pre-polymerized filler (ppf). this system is named trimodal nano-filler technology. tetric exhibited a low roughness value after applying the prophylactic paste and showed better results than giomer, which may be a result of this new trimodal system. our results support the claim of the manufacturer, that tetric n ceram is designed to offer high polishability. it has been shown that the introduction of finer particles among larger ones will result in reduction of interparticle spacing and the amount of resin matrix, thus maximizing the overall properties of the material. decreased interparticle spacing caused by reduced filler size may leads to reduction in strain localization around the filler, thus reducing the fatigue failure. the concept of multimodal fillers enables the composites to obtain high filler loading and allows a strong integration of small particles into resin matrix that can be eroded by breaking off small individual particles rather than large ones (18). based on the methodology used in this study we could conclude that the use of different prophylaxis methods resulted in a significant increase in surface roughness for both restorative materials and the roughest surface was created with apd. compared to untreated (control) group the surface roughness of the giomer and tetric ceram specimens treated with all prophylaxis methods were greater than 0.2 μm, which is a threshold value for bacterial adherence. therefore, re-polishing of giomer and tetric ceram restorations subsequent to the prophylaxis treatments tested might be necessary. given the results of the current study, further investigations j bagh college dentistry vol. 25(1), march 2013 the surface roughness restorative dentistry 24 on the surface roughness and abrasion resistance of giomer restorative materials are warranted. references 1ersoy m, civelek a, l’hotelier e, say ec, soyman m. physical properties of different composites. dent mater j 2004; 23:278–83. 2hilary pyt, betty yym, chew cl. bond strengths of glass ionomer restoratives to primary vs. permanent dentin. j dent child 2000; 67; 112-6. 3wiegand a, buchalla w, attin t. review on fluoridereleasing restorative materials fluoride release and uptake characteristics, antibacterial activity and influence on caries formation. dent mater 2007; 23:343-62. 4sunico mc, shinkai k, katoh y. two-year clinical performance of occlusal and cervical giomer restorations. oper dent 2005; 30: 282–9. 5agger ms, hörsted-bindslev p, hovgaard o. abrasiveness of an air-powder polishing system on root surfaces in vitro. quintessence int 2001; 32: 40711. 6yap au, wu ss, chelvan s, tan es. effect of hygiene maintenance procedures on surface roughness of composite restoratives. oper dent 2005; 30: 99104. 7yap au, wu ss, chelvan s, tan es. effect of prophylaxis regimens on surface roughness of glass ionomer cements. oper dent 2005; 30: 180-4. 8fawzy as, el-askary fs, amer ma. effect of surface treatments on the tensile bond strength of repaired water-aged anterior restorative micro-fine hybrid resin composite. j dent 2008; 36: 969-76. (ivl) 9jerusa co, glauber a, bruna m, vanessa mu, nara hc, janaina hj. effect of storage in water and thermocycling on hardness and roughness of resin materials for temporary restorations. materials research 2010; 13(3): 355-9. 10haktan y, arzu a, emre o, hilmi s, mubin s. influence of a prophylaxis paste on surface roughness of different composites, porcelain, enamel and dentin surfaces. eur j dent 2012; 6: 1-8. 11david a, covey, caren b, hidehiko w, johnson. effects of a paste-free prophylaxis polishing cup and various prophylaxis polishing pastes on tooth enamel and restorative materials. gen dentist 2011; 59(11). 12ahmet ug, i̇brahįm d, alį cy,pelįn o. effects of air polishing powders on the surface roughness of composite resins. j dent sci 2010; 5(3): 136−43. 13maristela dc, joão ms, lia ac, ângela b, clovis pagani. superficial roughness of composite resin submitted to different surface treatments – an in vitro study. rfo, passo 2011; 16(1): 64-8. 14soodabeh k, siavash s, amir-aa, alireza s, saeedeh a. effect of three prophylaxis methods on surface roughness of giomer. med oral patol oral cir bucal 2011 1; 16 (1): e110-4. 15daniele s, maria al. effect of prophylactic treatments on the superficial roughness of dental tissues and of two esthetic restorative materials. pesqui odontol bras 2003; 17(1): 63-8. 16soodabeh k, farzaneh l, reza p, alireza s, saeedeh n, morteza m. effect of two prophylaxis methods on adherence of streptococcus mutans to microfilled composite resin and giomer surfaces. med oral patol oral cir bucal 2011, 1; 16(4): e561-7. 17toshiyuki i, thomas e. carricka, masahiro y, john f. mccabe. release and recharge in giomer, compomer and resin composite. dental materials 2004; 20: 789– 95. 18hanadi ym. effect of filler particles on surface roughness of experimental composite series. j appl oral sci 2010; 18(1): 59-67. table 1: descriptive statistics of the surface roughness values in µm for all groups groups n mean sd se min. max. a1 5 1.24 0.181 0.081 1 1.5 a2 5 1.1 0.254 0.114 0.9 1.5 b1 5 1.74 0.313 0.140 1.2 2 b2 5 1.64 0.114 0.051 1.5 1.8 c1 5 1.78 0.148 0.066 1.6 2 c2 5 1.6 0.234 0.105 1.4 1.9 d1 5 1.48 0.164 0.073 1.2 1.6 d2 5 1.32 0.130 0.058 1.2 1.5 total 40 table 2: anova test comparison among subgroups with different surface treatment using giomer studied groups n mean sd df f p-value sig. a1 5 1.24 0.182 2 9.192 0.001 hs b1 5 1.74 0.313 c1 5 1.78 0.148 d1 5 1.48 0.310 total 20 j bagh college dentistry vol. 25(1), march 2013 the surface roughness restorative dentistry 25 figure 1: bar chart showing means value of surface roughness values in µm for all groups table 3: the least significant difference (lsd) of multiple comparison test for giomer studied subgroups according to surface treatment studied groups lsd (f-test) p-value sig. a1 b1 0.001 hs a1 c1 0.001 hs a1 d1 0.5 ns b1 c1 0.76 ns b1 d1 0.05 s c1 d1 0.03 s table 4: anova test comparison among subgroups with different surface treatment using tetric ceram studied groups n mean sd df f pvalue sig. a2 5 1.1 0.25 2 9.542 0.0017 hs b2 5 1.64 0.11 c2 5 1.6 0.23 d2 5 1.32 0.13 total 20 table 5: the least significant difference (lsd) of multiple comparison test for tetric ceram studied subgroups according to surface treatment studied groups lsd (f-test) p-value sig. a2 b2 0.026 s a2 c2 0.033 s a2 d2 0.031 s b2 c2 0.621 ns b2 d2 0.049 s c2 d2 0.342 ns table 6: t-test of multiple comparison test according to the type of restorative material. studied groups t-test p-value sig. a1 a2 0.758 ns b1 b2 0.427 ns c1 c2 0.532 ns d1 d2 0.256 ns group a1 control group a2 control group b1(apd) group b2(apd) group c1(brush) group c2(brush) group d1(rubber) group d2(rubber) j bagh college dentistry vol. 25(1), march 2013 the surface roughness restorative dentistry 26 figure 2: polarized light microscope figures after surface treatment of giomer and tetric ceram a1 giomer (control) a1 c2 tetric (brush) c2 d2 tetric (rubber) d2 b2 tetric (apd) b2 a2 tetric (control) a2 d1 giomer (rubber) d1 c1 giomer (brush) c1 b1 giomer (apd) b1 j bagh college dentistry vol. 29(1), march 2017 the effect oral and maxillofacial surgery and periodontics 111 the effect of treatment protocol and implant dimensions on primary stability utilizing resonance frequency analysis thair abdul lateef, b.d.s., h.d.d., f.i.b.m.s. (1) abstract background: according to branemark’s protocol, the waiting period between tooth extraction and implant placement is 6–8 months; this is the late placement technique. achieving and maintaining implant stability are prerequisites for a dental implant to be successful. resonance frequency analysis (rfa) is a noninvasive diagnostic method that measures implant stability. the aim of this study was to investigate the influence of treatment protocol and implant dimensions on primary implant stability utilizing rfa. materials and methods: this study included 63 iraqi patients (37 male, 26 female; ranging 22-66 years). according to treatment protocol, the sample was divided into 2 groups; a (delayed) & b (immediate). dental implants were inserted and the implant stability quotient (isq) measures for primary stability documented by osstell device. results: for both groups fixtures introduced in the mandible showed a higher stability (74 and 71.85) respectively and was lower in maxilla. the mean primary stability of group a was 70.21 (ranged from 51-83), while for group b was 68.55 (46.5-81). conclusion: primary stability influencing osseointegration and subsequent long term success. it was higher in association with delayed implant placement, mandible, and increased implant diameters. keywords: primary stability, immediate implant, isq. .(j bagh coll dentistry 2017; 29(1):111-116). introduction according to branemark’s protocol, the waiting period between tooth extraction and implant placement is 6–8 months; this is the late placement technique. series of biological processes such as bone resorption (vertically and horizontally), gingival collapse and migratory movements of the adjacent teeth to the extraction space occur during this period. other concerns about this protocol include the increased time of edentulism, longer treatment time and additional surgical procedure. in 1993 wilson and weber used the terms immediate, recent, delayed and mature, to describe the timing of implant placement after tooth extraction or the extraction socket’s healing process (1). some scholars proposed immediate implant technique, namely extracting the worthless remnant root and immediately embedding implant in situ at the same time. the clinical effect of this technique is accepted well (2). implants placed immediately into extraction sockets have been shown to have a high rate of clinical success (3). achieving and maintaining implant stability are prerequisites for a dental implant to be successful. implant stability can be defined as (1) assistant professor. department of oral and maxillofacial surgery.baghdad. iraq e-mail: d.thair_61@yahoo.com the absence of clinical mobility, which is also the suggested definition of osseointegration. primary implant stability at placement is a mechanical phenomenon that is related to the local bone quality and quantity, the type of implant and placement technique used (4). successful osseointegration is prerequisite for functional dental implants and primary implant stability is a prerequisite for successful osseointegration (4). primary implant stability is widely regarded as the central determinant of implant osseointegration success; how it is measured and quantified is not viewed with similar universal acceptance. clinical investigations involving large numbers of patients are vitally important to defining objective measures of primary implant stability related to dental implant success and the variables that modify success (5). the methods to determine implant stability clinically are clinical perception, percussion test, and reverse torque test, cutting torque resistance analysis, periotest and rfa (4). resonance frequency analysis (rfa) it is a noninvasive diagnostic method that measures implant stability and bone density at various time points using vibration and structural principle analysis. two commercially devices have been developed to assess implant stability. the original (electrical) method uses a direct connection (wire) between the transducer and the resonance frequency analyzer. the second method uses magnetic frequencies between transducer and resonance frequency analyzer. j bagh college dentistry vol. 29(1), march 2017 the effect oral and maxillofacial surgery and periodontics 112 the new magnetic rfa device has a transducer, a metallic rod with a magnet on top, which is screwed onto an implant or abutment. the electronic device and the magnetic device are capable of measuring similar changes; however the magnetic device results in higher implant stability quotient (isq) value when measuring the stability of nonsubmerged dental implant (4). the isq is a measure of interfacial stiffness presented by the implant bone interface. isqbased evaluations of primary implant stability have inferred that a number of variables affect stability. such variables include the following: (1) bone quality, (2) implant site (anatomic position), (3) age, (4) gender, (5) smoking status, (6) periodontal status, (7) implant diameter, (8) implant length and (9) implant design (5). the present study was performed to investigate the influence of certain variables (treatment protocol and implant dimensions) on primary implant stability utilizing rfa test. materials and methods in the period between october 2015 and june 2016, this study was conducted in the implantology unit at the department of oral & maxillofacial surgery, college of dentistry, university of baghdad, iraq. sixty three patients participated in this clinical prospective study (37 male, 26 female; ranging 22-66 years) needed one or more dental implant were selected. the whole sample was divided into 2 groups: 1group a: dental implants placed with the delayed protocol (at least 6 months after tooth extraction). 2group b: dental implants placed with immediate post extraction protocol. an informed written consent was secured from all patients using their data for research purposes. a number of exposure variables were evaluated in multivariate analyses including age, gender, implant dimensions and location. inclusion criteria 1fair oral hygiene. 2implants to be placed at least 6 months after teeth extraction and/or immediate post extraction placement of hopeless teeth or retained roots. 3patients age > 18 years. 4sufficient bone width and height to accommodate conventional implant therapy without alveolar bone augmentation. exclusion criteria 1poor oral hygiene. 2smoking more than 20 cigarettes/day and excessive alcohol consumption. 3high degree of bruxism. 4any systemic chronic disease affecting bone healing potential (localized radiotherapy of the oral cavity, antitumor chemotherapy, liver pathologies, immunosuppressed status, and current corticosteroid therapy, inflammatory and autoimmune disease of the oral cavity). 5current pregnancy. preoperative clinical and radiographical examination following detailed previous medical and dental history was taken for each patient using a special form of case sheet for the implant center. for radiological assessment, orthopantomogram (opg) was made for each candidate, (fig 1). surgical procedure for both groups treatment began for both groups with local anesthesia xylocaine/adrenaline 2% which was induced by block or infiltration technique. after elevation of mucoperiosteal flap, all implants were inserted according to a strict protocol that followed the manufacturer's instructions. for group b, immediate extraction of hopeless teeth/retained roots was performed as atraumatically as possible prior to implant installation, (fig 2). sutures were removed 10 days after surgery. for both groups, 150 implants (dentium, korea) were installed. with 100 implants for group a and 50 for group b. the actual isq (implant stability quotient) were collected for both groups with the aid of rfa (resonance frequency analysis) using osstell device (goteborg, sweden) with maximum insertion torque values of 35 n/cm during low speed insertion by means of a transducer attached to implant body (smart peg) and readings for the primary stability were scored, fig 4. isq values were considered as follows: low (0-50), medium (51-70) and high (71-100). patients instructed to take the following drug regimen: amoxicillin 500 mg + metronidazole 250 mg + paracetamol 500 mg /thrice daily for 5 days postoperatively. fig 1: diagnostic preoperative opg revealed hopeless tooth no.8. j bagh college dentistry vol. 29(1), march 2017 the effect oral and maxillofacial surgery and periodontics 113 fig 2: a. atraumatic extraction of hopeless tooth no. 8 presented with severe periodontitis prior to immediate implant placement. b. installation of dental implant into the socket of the extracted tooth. statistical analysis two independent sample t-test, paired t-test and pearson correlation (r) were the statistical method used to analyze the data. the level of significance tested according to the p-value, were: p>0.05 (not significant), p<0.05 (significant), p<0.01 (highly significant). the analyses were accomplished using computer software program: statistical package for social sciences (spss version 18). results the mean primary stability of group a was 70.21 (ranged from 51-83), while for group b was 68.55 (46.5-81). high isq values (>70) observed in 57% of dental implants placed in group a; however it was less for group b which recorded 42%. the 5th decade of life (40-49 years) was the dominant one for both groups, group a occupied (35.13%) and group b (30.77%). the prominent sex in this study were females (37 patients, 58.73%), while males attended with less number (26 patients, 41.27%) as clarified in table 1. regarding treatment protocol and site of placement: the mean primary stability for the group a was 70.21 isq, in which the anterior mandible recorded the highest value 75.5 isq, while the stability in anterior maxilla was the lowest 65.5 isq. on the other hand; for group b, the mean stability was lower than group a which was 68.55 isq, with predominance for the posterior mandible 76.37 isq, with also the least figures reported in anterior maxilla. for both groups fixtures introduced in the mandible showed a higher stability (74 and 71.85) respectively and was lower in maxilla. all these data exemplified in table 2. table 1: age and sex distribution. table 2: primary implant stability in relation to treatment protocol and site of placement. place ment protoc ol jaw site primar y stabilit y (mean isq) mandible maxilla group a (100 fixture s) anterio r 3 (3%) 30 (30%) 70.21 primary isq 75.5 65.5 posterio r 31 (31%) 36 (36%) primary isq 72.5 67.37 mean isq 74 66.43 group b (50 fixture s) mandible maxilla 68.55 anterio r 3 (6%) 67.33 32 (64%) 61.04 posterio r 2 (4%) 76.37 13 (26%) 69.46 mean isq 71.85 65.25 paired t-test showed significant difference in the isq value between the group a (0.000) and group b (0.003) (p<0.05), pearson correlation showed direct proportional relationship between group a & b (0.9 & 0.3) respectively, which indicates higher primary stability in group a, table 3 explains statistical results (table 3). in dentium system different implant dimensions utilized for this research. the highest stability regarding implant diameter registered with the widest diameter in group a (4.8 mm) in which the mean stability was 75.75 isq. while; the lowest figures noted with the narrowest diameter in this system (3.4 mm) which was 62.70, with the mean for all diameters 69.63. sex delayed (group a) immediate (group b) total female 22 (34.92%) 15 (23.81%) 37 (58.73%) male 15 (23.81%) 11 (17.46%) 26 (41.27%) bb j bagh college dentistry vol. 29(1), march 2017 the effect oral and maxillofacial surgery and periodontics 114 for group b (4.8 mm) diameter was not applied, as the highest stability reported with (4.3 mm) 70.66 isq, while; the lowest was with (3.8 mm) 59.68 isq, with the mean for all diameters 64.19 isq. these are demonstrated in table 4 and mean stability regarding the diameters was also higher in delayed protocol, fig 3. 0 10 20 30 40 50 60 70 80 90 100 mean isq isq & implant length isq & implant diameter group a group b fig 3: variables distribution. table 3: statistical results. sample size mean isq (placement protocol) mean isq (length) mean isq (diameter) t-test sig r p-value group a (100) 70.21 73.78 75.75 0.000 0.05 0.9 0.8 group b (50) 68.55 63.85 70.66 0.003 0.05 0.3 0.5 table 4: the effect of implant diameter on mean stability for both delayed and immediate placement. protocol & isq implant diameter (no. & %) group a(69.63) isq 3.4 mm 3.8 mm 4.3 mm 4.8 mm 3410 ► 10 (10%) 3412 ► 20 (20%) 3414 ► 3 (3%) 3808 ► 4 (4%) 3810 ► 11 (11%) 3812 ► 18 (18%) 3814 ► 4 (4%) 4308 ► 4 (4%) 4310 ► 16 (16%) 4312 ► 6 (6%) 4808 ► 2 (2%) 4810 ► 1 (1%) 4812 ► 1 (1%) mean stability 62.70 70.06 70.03 75.75 group b(64.19) isq 3412 ► 6 (12%) 3414 ► 7 (14%) 3812 ► 10 (20%) 3814 ► 24 (48%) 4310 ► 1 (2%) 4312 ► 2 (4%) -------- mean stability 62.23 59.68 70.66 in a correlation to the implant length for group a: the highest stability recorded with the length (14 mm) 73.78 isq and the lowest with (8 mm) 67.70 isq. while; for group b, the highest figure 81 isq was with (10 mm, insignificant) since single fixture is inserted. the lowest reported with (14 mm), however, most fixtures fall under the category of this length (31 dental implants) with 63.85 isq as shown in table 5. fig 4: isq primary stability measurement for tooth site no. 12 with the aid of osstell device. j bagh college dentistry vol. 29(1), march 2017 the effect oral and maxillofacial surgery and periodontics 115 table 5: the effect of implant length on mean stability for both delayed and immediate placement. treatment protocol implant length (no. & %) 14 mm % 12 mm % 10 mm % 8 mm % group a (69.95) isq 3414 ► 3 3814 ► 4 7% 3412 ► 20 3812 ► 18 4312 ► 6 4812 ► 1 45% 3410 ► 10 3810 ► 11 4310 ► 16 4810 ► 1 38% 3808 ► 4 4308 ► 4 4808 ► 2 10% mean stability 73.78 68.05 70.30 67.70 group b (69.67) isq 3414 ►7 3814►24 31 (62%) 3412►6 3812►10 4312►2 18 (36%) 4310►1 1 (2%) --------- mean stability 63.85 64.16 81 (insignificant) discussion the primary stability is considered to be as the password for osseointegration. gaining good primary stability is of paramount importance for successful osseointegration and subsequently achieving the main goal of dental implant placement from the functional and esthetic points of view which is the long term success. an objective precise measurement for primary stability is the rfa seems to be the most indicative. this study tried to analyze the influence of some important variables on the primary stability, those are treatment protocol (delayed vs immediate), site of fixture in the jaws and dental implant dimensions (diameter vs length). the 5th decade of life (40-49 years) was the prominent one in this study (21 patients, 33.33%), this is logic in the country since the general impression on patient compliance is poor for patients with teeth loss, not seeking for treatment at early time, also most of patients who ask for immediate implant placement presented with symptomless retained roots. females occupied the first place 37 (58.73%) with female: male ratio 37:26 (1.4:1). since most of fixtures for both groups introduced in the anterior region of maxilla and mandible (esthetic zone) about 33.3% for the group a and 70% for the group b (immediate placement), this is may be due to the willing desire in women for perfect esthetic more than males confirmed by (al garni et al. 2012) (6). in general the primary stability in group a (70.21 isq) was better than group b (68.55isq) and this may be related to the available amount of bone surrounding dental implant which is better with the delayed protocol than immediate postextraction implantation that is usually associated with alveolar defects and profound gaps between implant body and alveolar socket walls. this study revealed that the mean primary stability in the mandible was good for both groups a and b 74 isq and 71.85 isq respectively, this greatly related to the density of mandible which is better in all sites than the maxilla, here the maxilla showed medium stability for both functional zones 66.43 isq, 65.25 isq respectively. fyhrie, 2004 stated that bone density of the mandible found to be 4% higher than maxilla and decreases progressively as to go posteriorly (7). best stability observed with the bigger dental implant diameter that is the best was with (ø4.8 mm) implants 75.75 isq, followed by (ø4.3 mm and ø3.8 mm) 70.03 and 70.06 isq respectively. the least stability reported with the delayed protocol was with the narrowest conventional diameters ø3.4 mm (62.70 isq), as this is supported by many researchers as (barikani, 2013) (8). on the other hand with immediate placement the figures was unreliable with ø3.8 mm recorded the least stability 59.68 isq, higher stability registered with ø4.3 mm (few number 3) and ø3.4 mm. with immediate treatment many factors affecting the measurement as the socket wall gaps created after extraction or bone defects as dehiscence or fenestration. the length of dental implant has an influence on stability in group a. the stability was higher with 14 mm length dental implants (73.78 isq) and the least was with 8 mm. however this is not the case in immediate placement in which the dominant length was 14 mm (62%) but the lowest stability recorded 63.85 isq, however, clinically all implants had reasonable stability obtained by over-drilling procedure 2-3 mm beyond the depth of the socket walls. conclusion the primary stability is of eminent influence on osseointegration and subsequent long term success. it was higher in association with j bagh college dentistry vol. 29(1), march 2017 the effect oral and maxillofacial surgery and periodontics 116 delayed implant placement, mandible, and increased implant diameters. references: 1. mainetti t, lang np, bengazi f, favero v, soto cantero l, botticelli d. sequential healing at implants installed immediately into extraction sockets. an experimental study in dogs. clin oral implants res. 27. 2016. 130–138. 2. s. s. soydan, s. cubuk, y. oguz, s. uckan: are success and survival rates of early implant placement higher than immediate implant placement? int j oral maxillofac surg. 2013. 42: 511–515. 3. jinghui zhao, yanmin zhou, xiaolin sun, wang yue, a lan, gao donghui, liu yuyan. clinical study of delayed immediate implant. international conference on human health and biomedical engineering august, 2011.19-22. 4. nedir r, bischof m, szmukler-moncler s, bernard jp, samson j. predicting osseointegration by means of implant primary stability. clin oral implants res 2004. 15:520-528. 5. gaurang mistry, omkar shetty, shreya shetty, raghuwar d singh: measuring implant stability: a review of different methods. j dent implants | jul dec 2014. (2): 165-169. 6. al garni, b., pani, s.c., almaaz, a., al qeshtaini, e., abu-haimed, h., and sharif, k. factors affecting the willingness to pay for implants: a study of patients in riyadh. dent res j, 9(6): 2012.719-724. 7. fyhrie, d.b. summary-measuring "bone quality". journal of musculoskeletal & neuronal interactions, 2004.5(4): 318-320. 8. barikani, h., rashtak, s., akbari, s., badri, s., daneshparvar, n., and rokn, a. the effect of implant length and diameter on the primary stability in different bone types. j dent (tehran, iran), 10(5). 2013: 449-455. الخالصة اشهر: وهذا هو الوضع المتأخر للزرعة. الحصول وتحقيق ثبات 8-6استنادا الى مبدأ برينمارك, فان وقت االنتظار بين قلع السن ووضع الزرعة هو المقدمة: هي طريقة جيدة لقياس ثبات الزرعة.الغاية من هذه الدراسة هو فحص تأثير مبدأ وضع الزرعة rfaالزرعة هي اهم االهداف المطلوبة لنجاح الزرعة.جهاز ال . rfaوابعادها على ثبات الزرعة االولي بواسطة ال تين: سنة(. حسب توقيت العالج, قسمت العينة الى مجموع 66-66اناث, بين 66ذكور, 63مريض عراقي ) 66تتضمن الدراسة المواد وطرق العمل: مجموعة أ )المتأخر( و مجموعة ب )اآلني(. ادخلت الزرعات وقيست الثباتية االولية للزرعة بواسطة جهاز االوستيل. ( بالتعاقب وكانت اقل في الفك العلوي. كان 38,87و 37بالنسبة لكلتا المجموعتين التي ادخلت زرعاتها في الفك السفلي اظهرت تبات اعلى للزرعات ) النتائج: (.88-76,7) 68,77( , بينما كانت في المجموعة ب 86-78)بين 32,68دل الثبات االولي بالنسبة للمجموعة أ مع ة والفك ثبتت نتيجة البحث الحالي تأثير ثبات الزرعة االولي على التحامها بالعظم والنجاح طويل االمد. حيث كانت اعلى مع الوضع المتأخر للزرعاالستنتاجات: أ ازدياد ابعاد الزرعة.السفلي ومع 8balqees f.doc j bagh college dentistry vol. 28(3), september 2016 βcatenin expression oral diagnosis 52 βcatenin expression and its relation to bryne’s invasive grading system in oral squamous cell carcinoma marwa abdulsalam hamied, b.d.s., m.sc. (1) balkees taha garib, b.d.s., m.sc., ph.d. (2) dena nadhim mohammad, ph.d. (3) abstract background: invasion in oral cancer involves alterations in cell-cell and cell-matrix interactions that accompanied by loss of cell adhesion. catenins stabilize cellular adherence junctions by binding to e-cadherin, which further mediates cell-cell adhesion and regulates proliferation and differentiation of epithelial cells. the wnt/β-catenin pathway is one of the major signaling pathways in cell proliferation, oncogenesis, and epithelial-mesenchymal transition. aims of the study: to detect immunohistochemical distribution pattern and different subcellular localization of βcatenin in oral squamous cell carcinoma and relate such expression to bryne’s invasive grading system. materials and methods: this study included 30 paraffin blocks of primary oral squamous cell carcinoma. bryne’s grading performed on routein stained slides. immunohistochemical staining for anti β-catenin was done to illustrate its pattern and subcellular localization in malignant cells. the expression correlated with the invasive grading system. results: β-catenin expression detected in all sample (100%). it was (23.3%) membranous, (60%) aberrant cytoplasmic and (16.7%) mixed expression. diffuse strong homogeneous pattern was observed in (40%) of the cases. the cytoplasmic expression had significant high mean rank in score 3, diffuse strong homogeneous pattern and strong intensity. well-differentiated carcinoma expressed great mixed membranous/cytoplasmic expression while poordifferentiated cases showed low membranous mean rank expression. the strong diffuse homogeneous pattern with strong staining was significantly frequent in well-differentiated squamous cell carcinoma. conclusion: increase cytoplasmic β-catenin expression is parallel with carcinoma dedifferentiation. suggesting maintenance of its adhesive role with the inhibition of the normal degradation of free β-catenin in the cytoplasm, which might cause accelerated tumor cell proliferation. keywords: β-catenin, membranous, bryne’s grading. (j bagh coll dentistry 2016; 28(3):52-58). introduction invasion and metastasis of oral cancer involve complex multistep processes that lead to alterations in cell-cell and cell-matrix interactions. these changes are accompanied by loss of cell adhesion, even in the very early stages of cancer development (1,2). epithelial-mesenchymal transition (emt) is critical for regulating embryonic development and for epithelial-derived tumors to become invasive and metastasize. both developmental and oncogenic emt associated with the loss of apical-basal polarity, destabilization of intercellular adhesion complexes (gap junctions, desmosomes, tight junctions and adherence junctions) and replacement of epithelial cell markers (e-cadherin and β-catenin) by mesenchymal cell markers (ncadherin and vimentin). thus, they lead cells to get migratory and invasive ability (3). catenins stabilize adherence junctions. they bind to e-cadherin, which mediate cell-cell adhesion, regulate proliferation and differentiation of epithelial cells (4). moreover, catenin is essential in the task of e-cadherin and brings about strongly invasive characteristics when the expression or structure of e-cadherin fails (5). (1)assist. lecturer. school of dentistry, faculty of medical sciences, university of sulaimani. (2)professor. school of dentistry, faculty of medical sciences, university of sulaimani. (3)lecturer. school of dentistry, faculty of medical sciences, university of sulaimani. the wnt/β-catenin pathway is one of the major signaling pathways in cell proliferation, oncogenesis, and emt. it has an independent function in cell adhesion and signal transduction. there are at least two distinct pools of β-catenin in cells. these include a cell membrane-associated pool and a pool involved in wnt signaling and gene transcription (6,7). on the other hand, nuclear β-catenin acts as a transcription factor in a complex with the hmg-box proteins of the tcf/lef family. thereby, they act contrarily in regulating target gene transcription, depending on the nuclear β-catenin level (8,9). nuclear localization of β-catenin has shown to involve in precancerous changes in oral leukoplakia and progression of oscc, lymph node metastasis and cell proliferation (10). furthermore, the aberrant cytoplasmic accumulation of β-catenin induces tcf/lef-mediated transcriptional activity, upregulates mmp-7, and encourages emt in oral squamous cell carcinoma (oscc). hence, it augments invasion and migration in oscc (11). the altered β-catenin expression is demonstrated in a variety of human cancers (12-14). in oscc, β-catenin localization was detected in cytoplasm and nucleus in parallel with wnt expression at the invasive front (15). moreover, an abnormal β-catenin expression is associated with poor differentiation and related to cellular proliferation in tumor progression (16) and lymph j bagh college dentistry vol. 28(3), september 2016 βcatenin expression oral diagnosis 53 node metastasis (17). it appears that the loss of membranous expression of β-catenin and ecadherin is a characteristic feature of oscc. similarly, loss of membranous β-catenin often occurs at the invasive front of poorly differentiated oscc, which could constitute a hallmark of an aggressive biological behavior of tumor cells. likewise, invasion and metastasis of oscc have been shown to require methylation of e-cadherin and degradation of membranous βcatenin (18). this study aims to detect immunohistochemical changes in both distribution pattern and subcellular localization of β-catenin in oral squamous cell carcinoma. then correlate such expression to bryne’s invasive grading system to distinguish the role of this expression in the progression of oscc. materials and methods a retrospective study accomplished in school of dentistry / university of sulaimani, from march to the end of december 2014. the ethical committee of faculty of medical science, university of sulaimani approved the study. the sample included 30 formalin fixed paraffin embedded blocks previously diagnosed as primary oscc collected from shorsh hospital and private histopathological laboratories in sulaimani. available clinical data recorded from archive case sheets. two serial 5µm tissue sections cut from each block. the area of concern was the deep front and lateral invasive sites of the growth. one section stained with hematoxylin and eosin for histopathological evaluation. the other section subjected to immunohistochemical staining by keeping it in the oven (60ºc) overnight. next day, after deparaffinized and rehydrated the sections, heat antigen retrieval performed (citrate buffer, ph 6, 15 min, 95ºc). sections allowed cooling down to room temperature, then endogenous peroxidase activity blocked by hydrogen peroxidase (10 min). after that sections incubated with protein block (10 min) to block nonspecific background staining. later sections incubated with anti-rabbit -βcatenin polyclonal primary antibody (1:100 dilution, 45 min, abcam company) then washed three times with phosphate buffer saline. next, the sections incubated with complement (10 min) and washed twice with phosphate buffer saline. goat anti-rabbit hrp conjugate applied (15 min) and then washed three times. slides stained by dab chromogen (5 min, in the dark), and counterstained with hematoxylin. the sections dehydrated, cleared and mounted with dpx and cover slide. normal oral epithelium serve as a positive control (16) while applying the antibody diluents alone without primary antibody served as negative control. hematoxylin and eosin stained slides assessed according to bryne’s grading system (19). immunohistochemically stained sections analyzed by image j software at (400x) and semiquantitatively scored as follow: score 0 = <10%, score 1 = 10 -30%, score 2 = 31-50% and score 3 = >50%. the intensity scored as weak, moderate and strong (20). concerning expression pattern, sections analyzed (under 100x) into: 1=absent, 2=focal heterogeneous, 3=reduced homogeneous and 4=strong homogeneous (21). statistical analysis performed by using spss 20.0.software and applying chi-square and kruskal-wallis test. the correlation of grading system to scoring, pattern, and intensity of staining tested by somers’d correlation coefficient. results bryne’s grading system showed that mdoscc constituted the most frequent histopathological grade (13 cases; 43.3%). the strength of the relationship between the clinical data and grading system was analyzed. sex factor had little effect (v<0.3) and the age had a medium effect (v =0.3) on the histopathological grade (table -1). β-catenin expression in normal oral epithelia was strong membranous in the basal, para-basal and prickle cell layers (fig -1a). similarly, oscc showed 100% β-catenin as a membranous expression in the basal and para-basal layers of epithelial islands. still the polyhedral cells layer in organized islands revealed cytoplasmic staining and the other unorganized carcinomatous cellsgrowth showed even mixed expression. thus, in a single section, one may see more than one type of sub-cellular localization. nevertheless, in oscc, β-catenin was (40%) membranous expression (23.3% pure membranous and 16.7 % mixed) (fig-1b), and (60%) only cytoplasmic expression (fig-1c). within the above cases, nuclear membrane localization (16.6%) and perinuclear condensation (20%) were also seen (fig-1 d). no case had β-catenin with score one expression (positivity in 10-30% of the examined cells) and 40% of the cases had a diffuse strong homogeneous pattern. lastly strong staining was evident in 43.3% of oscc cases (table 2). regarding mean ranks expression of subcellular localization, the membranous expression had a higher mean rank in score 0 and j bagh college dentistry vol. 28(3), september 2016 βcatenin expression oral diagnosis 54 3, with a focal heterogeneous pattern of expression and weak staining. while the cytoplasmic expression showed significant high mean rank in score 3, diffuse strong homogeneous pattern and strong intensity. finally mixed (membranous + cytoplasmic) expression illustrated significant expression in both diffuse strong homogeneous pattern and strong intensity (table 3). wd-oscc had a high mean rank percentage of mixed (membranous and cytoplasmic) expression. cytoplasmic expression showed great mean rank in md-oscc. only the mixed expression was significantly different (p=0.034, table -4). β-catenin score 3 was observed equally in wdand md-osccs (7 cases). a significant strong diffuse homogeneous pattern seen in wdosccs (8 cases) (p=0.026). the grades had a medium reverse effect on the pattern and score (d value was between -0.3 and -0.5). lastly, the strong staining expression was significantly frequent in wd-osccs (9 cases) (p=0.002). the grade had a strong reverse effect on the intensity (d >-0.5) so that the strongest the stain the least the grade (table -5). table 1: the distribution of clinical data related to bryne’s grading systems clinical bryne’s system well moderate poor exact sig. cramer’s v se x male 6 7 3 1.000 0.034 female 5 6 3 a ge gr ou ps < 50 years 6 4 0 0.140 0.333 50-69 years 4 4 3 > 69 years 1 5 3 total 11 13 6 table 2: frequency and percentage distribution of different positive β-catenin expression localization, score, pattern and staining intensity in oscc expression no. % total positive cases 30 100.0 localization membranous 7 23.3 cytoplasmic 18 60 mixed 5 16.7 within above cases nuclear 2 6.7 nuclear membrane 5 16.6 perinuclear 6 20 score 0 7 23.3 1 0 0 2 8 26.8 3 15 50 pattern absent 0 0 focal heterogeneous 7 23.3 diffuse reduce homogeneous 11 36.7 diffuse strong homogeneous 12 40 intensity negative 0 0 weak 8 26.7 moderate 9 30 strong 13 43.3 j bagh college dentistry vol. 28(3), september 2016 βcatenin expression oral diagnosis 55 table 3: β-catenin expressions percentage mean ranks in osccs related to the total score, pattern of expression and intensity of staining expression % mean ranks score pattern intensity 0 1 2 3 a bs en t f .h d .r .h d .s .h n eg at iv e w ea k m od er at e st ro ng membranous 17.5 0 10.1 17.4 0 17.5 14.8 14.9 0 17.2 13.8 15.5 p value 0.075 0.749 0.691 cytoplasmic 5.7 0 17.7 18.8 0 7.8 15.3 20.08 0 8.8 16.4 18.9 p value 0.001 0.010 0.031 mixed 11.1 0 14.8 17.8 0 9 13.9 20.7 0 9 15.06 19.8 p value 0.178 0.004 0.007 total positive cells 0 5.2 14.1 22.6 0 7 14.4 21.4 p value 0.000 0.000 f.h: focal heterogeneous pattern; d.r.h: diffuse reduced homogeneous pattern; d.s.h diffuse strong homogeneous pattern. table 4: β-catenin subcellular localization mean ranks related to bryne’s grades expression % mean ranks bryne’s grading system kruskal-wallis monte carlo sig. well moderate poor membranous 18.45 15.15 10.83 0.161 cytoplasmic 14.41 17.08 14.08 0.692 mixed 20.23 12.04 14.33 0.034 total 18.59 15.54 9.75 0.139 . table 5: β-catenin score, pattern of expression and intensity of the stain in bryne’s grading system expression bryne’s grading system well moderate poor linear by linear sig somers’ d score 0 1 3 3 0.050 -0.320 1 0 0 0 2 3 3 2 3 7 7 1 pattern absent 0 0 0 0.026 -0.396 f.h 1 4 2 d.r.h 2 6 3 d.s.h 8 3 1 intensity negative 0 0 0 0.002 -0.522 weak 0 5 3 moderate 2 5 2 strong 9 3 1 f.h: focal heterogeneous pattern; d.r.h: diffuse reduced homogeneous pattern; d.s.h.: diffuse strong homogeneous pattern. j bagh college dentistry vol. 28(3), september 2016 βcatenin expression oral diagnosis 56 a b c d figure-1: photo micrograph for β-catenin localization in normal oral mucosa and osccs (400x). membranous expression in normal oral mucosa (a) and oscc (b). cytoplasmic expression in oscc (c) and nuclear membrane with perinuclear condensation in oscc (d). abbreviations: oral squamous cell carcinoma (oscc), well differentiated (wd), moderate differentiated (md), poor differentiated (pd), epithelial-mesenchymal transition (emt) discussion by the application of bryne’s invasive system, oscc were more frequently at high grades (moderate and poor differentiation). in agreement with published literature (10,22), the membranous immunohistochemical expression of β-catenin of normal oral epithelia reflect its role as an adhesion molecule. it localized to the cell membrane of all keratinocytes layers. on the other hand, the majority of cancerous islands showed membranous basal and suprabasal staining, still the superficial areas either loose or get shifting of the β-catenin staining to the cytoplasm compartment. therefore, β-catenin in these cells has conserving cellular adhesion and has other vital function related to differentiation and proliferation (22). the high percentage of β-catenin aberrant cytoplasmic localization (60%) and the persistence of membranous expression in 23.3% of cases are in agreement with other studies (22, 23). iwai et al. indicated that cytoplasmic expression might induce tcf/lef-mediated transcriptional activity and up-regulate mmp-7. also it prompts rho family member mediated reorganization of the actin cytoskeleton and redistribution of ecadherin (11). accordingly this results in emt of oscc cells and rising cell invasion and migration. while nuclear and nuclear-membrane localization showed 23.3% expression. here it is believed that nuclear β-catenin functions as oncogenes. it interacts with the transcription factor tcf/lef complex, which facilitates independently the expression of c-myc and cyclin d1, in which they had a key role in both cell cycle control and cellular proliferation (24). the predominance of homogeneous diffuse βcatenin expression throughout the growth (36.7% diffuse reduced and 40% diffuse strong) do not fit with the heterogeneous nature of oscc growth. thus, biologically most cells might categorize toward gaining more neoplastic features and showing aggressive performance. in agreement with previous reports (17, 20), βcatenin has strong staining in 43.3% of cases. this strong high intensity reflects the accumulated large amount of β-catenin within the cytoplasm. this finding may explain by the reduction in protein degradation that reduces its binding to ecadherin. the focal, faint, low score of β-catenin expression in cell membrane ascertain cells that lost adhesion with the neighboring surrounding cells within a mass. it is believed that these cells start to inter the cell cycle (proliferating islands) since β-catenin expression increase with proliferating basal and parabasal layers (25, 26). still there are focal areas that showed up-regulation of j bagh college dentistry vol. 28(3), september 2016 βcatenin expression oral diagnosis 57 this unstable marker. on the other hand, the diffuse strong homogeneous, with strong staining and high scoring were linked to the cytoplasmic expression. this findings suggest stabilization of β-catenin to acts as a signaling molecule and increased membranous degradation (loss of the adhesive function). such accumulation also mediates transcriptional activity leading to upregulation of oncogenes and increase invasion and metastasis. thus identifying the extension and distribution pattern of β-catenin provide valuable information about cell behavior at least about different stages of cell differentiation during tumorigenesis. the present work identified that β-catenin has a persistent membranous expression in wdoscc, shifting from membranous to cytoplasmic in md-oscc and minimum total positive expression in pd-oscc. this altered localization was in agreement with other studies (22, 23). they showed a decrease in membranous expression in parallel with carcinoma dedifferentiation and invasion. in this study, it was obsereved that among the higher-grade tumor, there were reduced membranous expression and predominant weak intensity, with reduce homogenous diffuse pattern of expression. this finding possibly relates the mechanical pathway of β-catenin to the invasive front and the possible β-catenin interacting signaling to modulate the invasive ability of oral cancer. in conclusion; β-catenin persevered membranous expression in well-differentiated cells as adhesion molecule. it augmented cytoplasmic expression in parallel with carcinoma dedifferentiation and invasion. therefore, it is suggested that β-catenin maintenane its role as a signaling molecule and the normal degradation of free β-catenin in the cytoplasm inhibited. the descending pattern and intensity of staining of this marker with high-grade tumor further support its role in detecting the progression and acceleration of oral cancer. references 1. daniel fi, fava m, hoffmann rr, campos mm, yurgel ls. main molecular markers of oral squamous cell carcinoma. applied cancer res 2010; 30(3): 27988. 2. abdul-majeed aa, farah cs. can immunohistochemistry serve as an alternative to subjective histopathological diagnosis of oral epithelial dysplasia? biomark can 2013; 5: 49-60. 3. micalizzi ds, farabaugh sm, ford hl. epithelialmesenchymal transition in cancer: parallels between normal development and tumor progression. j mammary gland biol neoplasia 2010; 15: 117–34. 4. tinkle cl, lechler t, pasolli ha, fuchs e. conditional targeting of e-cadherin in skin: insights into hyper proliferative and degenerative responses. proc natl acad sci usa 2004; 10(2): 552-7. 5. imai k, maeda g, chiba t. cadherin expression and progression of head and neck squamous cell carcinomas of oral cavity. in: li x (ed.). squamous cell carcinoma. rijeka, croatia: intech; 2012. p. 12136 6. willert k, nusse r. β-catenin: a key mediator of wnt signaling. curr opin genet dev 1998; 8(1): 95–102 7. kudo y, kitajima s, ogawa i, hiraoka m, sargolzaei s, keikhaee mr, et al. invasion and metastasis of oral cancer cells require methylation of e-cadherin and/or degradation of membranous β-catenin. clin cancer res 2004; 10(16): 5455–63. 8. schmalhofer o, brabletz s & brabletz t. e-cadherin, β-catenin, and zeb1 in malignant progression of cancer. cancer metastasis rev 2009; 28(1-2): 151-66. 9. maher mt, flozak as, stocker am, chenn a, gottardi cj. activity of the β-catenin phosphodestruction complex at cell-cell contact is enhanced by cadherin-based adhesion. j cell biol 2009; 186(2): 219-28. 10. kaur j, sawhney m, dattagupta s, shukla nk, srivastava a, walfis pg et al. clinical significance of altered expression of β-catenin and e-cadherin in oral dysplasia and cancer: potential link with alcam expression. plos one 2013; 8(6): e67361. 11. iwai s, yonekawa a, harada c, hamada m, katagiri w, nakazawa m et al. involvement of the wnt-ßcatenin pathway in invasion and migration of oral squamous carcinoma cells. int j oncol 2010; 37(5): 1095-103. 12. barker n, van es jh, kuipers j, kujala k, van den born m, cozijnsen m et el. identification of stem cells in small intestine and colon by marker gene lgr5. nature 2007; 449(7165): 1003-7. 13. von rahden bh, kircher s, lazariotou m, reiber c, stuermer l, otto c et al. lgr5 expression and cancer stem cell hypothesis: clue to define the true origin of esophageal adenocarcinomas with and without barrett’s esophagus? j exp clin cancer res 2011; 30(1): 23 14. li lf, wei zj, sun h, jiang b. abnormal β-catenin immunohistochemical expression as a prognostic factor in gastric cancer: a meta-analysis. world j gastroenterol 2014; 20(34): 12313-21. 15. uraguchi m, morikawa m, shirakawa m, sanada k, imai k. activation of wnt family expression and signaling in squamous cell carcinomas of the oral cavity. j dent res 2004; 4: 327-32. 16. yun x, wang l, cao l, okada n, miki y. immunohistochemical study of β-catenin and functionally related molecular markers in tongue squamous cell carcinoma and its correlation with cellular proliferation. oncol lett 2010; 1(3): 437-43. 17. ueda g, sunakawa h, nakamori k, shinya t, tsuhako w, tamura y et al. aberrant expression of betaand gamma-catenin is an independent prognostic marker in oral squamous cell carcinoma. int j oral maxillofac surg 2006; 35(4): 356-61. 18. zhou g. wnt/β-catenin signaling and oral cancer metastasis. in: myers j, editor. oral cancer metastasis. 1st ed. new york: wb springer; 2010. p. 231-264. 19. bryne m, koppang hs, lilleng r, kjaerheim a. malignancy grading of the deep invasive margins of j bagh college dentistry vol. 28(3), september 2016 βcatenin expression oral diagnosis 58 oral squamous cell carcinomas has high prognostic value. j pathol 1992; 166(4): 375-81. 20. laxmidevi lb, angadi pv, pillai kr, chandreshekar c. aberrant β-catenin expression in the histologic differentiation of oral squamous cell carcinoma and verrucous carcinoma: an immunohistochemical study. j oral sci 2010; 52 (4): 633-40. 21. lyakhovitsky a, barzilai a, fogel m, trau h, huszar m. expression of e-cadherin and beta-catenin in cutaneous squamous cell carcinoma and its precursors. am j dermatopathol 2004; 26: 372-8. 22. santoro a, pannone g, papagerakis s, mcguff hs, cafarelli b, lepore s, et al. β-catenin and epithelial tumors: a study based on 374 oropharyngeal cancers. biomed res int 2014; 2014: 948264. 23. hanemann ja, oliveira dt, nonogaki s, nishimoto in, de carli ml, landman g, et al. expression of ecadherin and β-catenin in basaloid and conventional squamous cell carcinoma of the oral cavity: are potential prognostic markers? bmc cancer 2014; 14: 395 24. yao cj, lai gm, yeh ct, lai mt, shih ph, chao wj, et al. honokiol eliminates human oral cancer stem-like cells accompanied with suppression of wnt/ -catenin signaling and apoptosis induction. evid based complement alternat med 2013; 2013: 146136. 25. liu lk, jiang xy, zhou xx, wang dm, song xl, jiang hb. upregulation of vimentin and aberrant expression of e-cadherin/β-catenin complex in oral squamous cell carcinomas: correlation with the clinicopathological features and patient outcome. mod pathol 2010; 23(2): 213–24 26. balasundaram p, singh mk, dinda ak, thakar a, yadav r. study of β-catenin, e-cadherin and vimentin in oral squamous cell carcinoma with and without lymph node metastases. diagn pathol 2014; 9: 145. 11. afrah f.doc j bagh college dentistry vol. 25(1), march 2013 evaluation of salivary oral diagnosis 63 evaluation of salivary levels of proteinaceous biomarkers matrix metalloproteinase (mmp-8) and c-reactive protein (crp) in type 2 diabetic patients with periodontitis afrah a. abbas, b.d.s (1) raja aljubouri, b.d.s, m.sc., ph.d. (2) abstract background: diabetes mellitus is a chronic metabolic disorder of the carbohydrate, protein and fat metabolism, resulting in increased blood glucose levels. various complications of diabetes have been described with periodontitis being added as the sixth complication of diabetes mellitus. matrix metalloproteinase-8 (mmp-8) has been identified as major tissue-destructive enzyme in periodontal disease. mmp-8 is released from neutrophils in a latent, inactive pro form and becomes activated during periodontal inflammation by independent and/or combined actions of hostderived inflammatory mediators .c-reactive protein is a systemic marker released during the acute phase of an inflammatory response. subjects, materials and methods: total samples composed of 60 participant and they divided into (20 patients un complicated type 2 diabetes with periodontitis , 20 patients non diabetic with periodontitis and 20 subjects normal control " with no sign of gingivitis or periodontitis" ) . diabetes assessment was performed according to abraham (1982).attachment loss were assessed using periodontal disease index of ramfjord (1959) .un stimulated whole saliva samples were collected and chemically analyzed for quantitative measurments of salivary (mmp-8 and crp).blood samples were collected and then measure (hba1c , fbs , esr ). all data were analyzed using spss version 20. results: it was found that the salivary (mmp-8, crp) levels were lower in normal controls compared to other groups, the blood esr level was lower in normal controls compared to other groups and there were no important differences in mean blood esr, salivary mmp-8 and median salivary crp between diabetic and non diabetic with periodontitis . conclusions: severity of periodontitis increase with increase age , salivary mmp-8 ,crp and blood esr levels were elevated in patients with periodontitis with or without diabetes , crp and mmp-8 are considered a useful tests in predicting periodontitis ,and in type 2 diabetic patient there was a relationship between metabolic control of diabetes and severity of periodontal disease. key words: diabetes mellitus, periodontitis, matrix metalloproteinase-8, c-reactive protein. (j bagh coll dentistry 2013; 25(1):63-69). introduction diabetes mellitus (dm) is the most common metabolic disease worldwide. more than 90% of dm patients have type 2 diabetes, dm is the leading cause of blindness, renal failure, and lower limb amputations and consider as major risk factor for cardiovascular disease, stroke, neuropathy, and periodontitis (1,2). periodontitis is the most common complication of dm, and results from extension of the inflammatory process initiated by bacteria in the gingiva to the supporting periodontal tissues. a reciprocal relationship exists between dm and periodontal disease (3). periodontal infections, like other infections, have a significant impact on diabetic control. conversely, dm is a significant risk factor for the development of periodontal disease and aggravates the severity of periodontal infections (4). its well known that chronic periodontitis is characterized by inflammatory cell accumulation within periodontal tissues. this situation leads to a chronic inflammation and continuous host response, resulting in tissue destruction. four distinct pathways may be involved in this destruction: plasminogen dependent, phagocytic, osteoclastic and matrix metalloproteinase (mmp) pathway. (1) master student, department of oral diagnosis. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. experimental evidence suggests that the most important pathway involve mmps as active collagenase and gelatinases which are found not only in the cervicular gingival fluid but also in saliva (5). matrix metalloproteinases (mmps) are zinc-dependent endopeptidases derived from polymorphonuclear leukocytes during acute stages of periodontal disease and are the key enzymes responsible for extracellular collagen matrix degradation (6). c-reactive protein is a systemic marker released during the acute phase of an inflammatory response. c-reactive protein is produced by the liver and is stimulated by circulating cytokines, such as tumor necrosis factor and interleukin-1, from local and ⁄ or systemic inflammation such as periodontal inflammation , circulating c-reactive protein may reach saliva via gingival crevicular fluid or the salivary glands (7,8). c-reactive protein has recently been shown to be measurable in saliva from periodontal patients (9, 10). subjects, materials and methods the study population consisted of 20 patients with type 2 diabetes mellitus and periodontitis , 20 patients non diabetic with periodontitis and 20 subject normal control (with no sign of gingivitis or periodontitis). a prospective study was done in j bagh college dentistry vol. 25(1), march 2013 evaluation of salivary oral diagnosis 64 marjan general hospital in hilla city in babylon and the laboratory work was done in the lab of the hospital. diabetes assessment was performed according to abraham (11). clinical examination was conducted to assess the attachment loss condition, then blood and saliva samples were taken. the periodontal examination was performed under the natural light with the patients seated on an office chair. a mouth mirror, william periodontal probe and sterilised gauzes were used for intra oral examination and the assessment of the patients (pocket depth and gingival recession to measure attachment loss). attachment loss was assessed using periodontal disease index of (12). all surfaces of the six ramfjord teeth were examined. if an index tooth was missing, the nearest distal tooth was substituted for examination and the patient will be examined if he had at least 5 of 6 ramfjord teeth. all the patients were examined by one individual. after a through clinical examination were done 10 millilitres of unstimulated whole saliva was collected and a sample of blood was taken. the collected saliva was centrifuged at 3000 r.p.m (rotation per minute) for 10 minutes and then centrifuged clear supernatant saliva kept frozen and stored at -20 °c until the whole saliva samples were collected, then the mmp-8 and crp determination done using quantikine (human total mmp-8 immunoassay) mmp-8 elisa kit for quantitative measurement of salivary mmp-8 and salimetrics (salivary c-reactive protein) elisa kit for quantitative measurement of salivary crp respectively. blood sample was taken from each individual. the whole blood was collected in sterile edta tubes and after complete sample collection from patients in the same day we measure hba1c by stanbio glycohemoglobin kit for quantitative determination of hba1c in whole blood, fbs by enzymatic colorimetric method and esr by westergren method. statistical analysis was done by using correlation test by the aid of the spss version 20 (statistical package for social sciences). results as shown in table (1) in this study diabetic group divided into two groups according to severity of attachment loss by consider the median of attachment loss (5.1) so less sever (<=5.1), sever (>5.1) and then make comparison as below. mean age was obviously higher among diabetic with sever periodontitis (47.9 years) compared to those with less sever periodontitis (42.8 years), but the difference observed failed to reach the level of statistically significance. mean blood esr was obviously higher among diabetic with sever periodontitis (33.8 mm/hour) compared to those with less sever periodontitis (27.4 mm/hour), but the difference observed failed to reach the level of statistically significance. the median salivary crp was obviously higher among diabetic with sever periodontitis (5562 pg/ml) compared to those with less sever periodontitis (4693 pg/ml), but the difference observed failed to reach the level of statistically significance. there was a weak and statistically insignificant positive (direct) linear correlation between attachment loss and crp, r= 0.179, p= 0.45 [ns]. the mean salivary mmp-8 was obviously higher among diabetic with sever periodontitis (259.6 ng/ml) compared to those with less sever periodontitis (234.3 ng/ml), but the difference observed failed to reach the level of statistically significance. the mean fasting serum glucose conc. was obviously higher among diabetic with sever periodontitis (259.1mg/dl) compared to those with less sever periodontitis (184.5 mg/dl), but the difference observed failed to reach the level of statistically significance. the mean hba1c was significantly higher (7.4 %) among diabetics with sever periodontitis compared to those with less sever periodontitis (5.9 %). table (2) shows that non diabetic with periodontitis group divided into two groups according to severity of attachment loss by consider the median of attachment loss (5.1) so less sever (<=5.1), sever (>5.1) and then make comparison as below. there were no important or statistically significant differences in mean age, esr and median crp between non diabetics with sever periodontitis compared to those with less sever periodontitis. the mean mmp-8 was obviously higher (274.1 ng/ml) in those with sever periodontitis compared to those with less sever periodontitis (243.0), but the difference failed to reach the level of statistically significance. mmp-8 showed a statistically significant, moderately strong positive linear correlation ( r=0.528) with attachment loss .table (3) and figure (1) shows receiver operating characteristic (roc) test , for measuring the validity for selected parameters when used to diagnose periodontitis differentiating from healthy controls , crp and mmp-8 were considered useful tests in predicting periodontitis (biochemical indicator of periodontal disease severity) with area under roc (1.0000, 0.999) respectively and the esr consider the third one used for predicting periodontitis with area under roc (0.888). table (4) and figure (2) shows roc test, for measuring the validity for selected parameters when used to predict dm among cases j bagh college dentistry vol. 25(1), march 2013 evaluation of salivary oral diagnosis 65 with periodontitis , crp , mmp-8 and esr were not used for diagnosis of dm with area under roc ( 0.627, 0.655, 0. 533) respectively. discussion based on the results obtained in our study that in diabetic patients with periodontitis group, as the age of diabetic patients increase, the severity of periodontal disease increases this in accordance with result obtained by neelima et al. (13), oliver & tervonen (14), the mean blood esr are higher among diabetic with sever periodontitis compared to those with less sever periodontitis this in accordance with result obtained by moder (15). after analyzing correlations, results have shown that higher values of salivary crp are found as periodontal disease severity increase and this in agreement with result obtained by fernando et al. (16), forner et al. (17). in our study we found a correlation between increased severities of periodontitis and elevated salivary mmp-8 levels in patients with type 2 diabetes. the result of this study disagree with the result obtained by costa et al. (18) who found that salivary mmp-8 concentrations were elevated regardless of periodontal inflammation in patients with type 2 diabetes mellitus. in this study, it was observed the severity of periodontal disease increase with the increase in the blood glucose level. this finding is an indicator of the need for improving oral health status among diabetic patients, results of the present study is in accordance with previous studies by khalid et al. (19). this clinical study had found that the mean hba1c was significantly higher among diabetics with sever periodontitis compared to those with less severe periodontitis. this means that diabetics with poor metabolic control (high hba1c) have a higher prevalence and more extensive periodontitis than diabetics who maintain good control. thus, metabolic control of diabetes may be an important variable in the onset and progression of periodontal disease. this is in agreement with the results obtained by seppala & ainamo (20). based on the results obtained in this present study that in non diabetic patients with periodontitis group , the severity of periodontitis not increase with or not depend on age and this disagree with other previous studies , perhaps due to the small size of study population. the results of this study disagree with the result obtained by khansa et al. (21). in this study the mean esr not increase with or not depend on severity of periodontitis and this disagree with result obtained by ali (22). in this study the median salivary crp not increase with or not depend on severity of periodontitis. in this study, it was observed that the level of mmp-8 in saliva increase with increase in severity of periodontitis. however, the difference did not reach statistical significance, perhaps due to the small size of study population. the result of this study consistent with previous studies by lee et al., and raquel et al. (23, 24) they reported that the collagenase activity was positively associated with the severity of periodontal disease, and mmp-8 accounted for most of the collagenase activity in adult periodontitis patients uitto et al. and overall et al. (25,26). strong correlation between mmp-8 and severity of periodontitis as measured by level of attachment loss, such as those described here, support the assertion that mmp-8 is a biochemical indicator of periodontal disease severity and may relate to disease activity and this in agreement with herr et al. (27) who said, mmp-8 is not only indicator of disease severity but also disease activity and in agreement with result obtained by zia et al. (28) who reported the same results. in this study we found that crp was the most valid parameter in predicting periodontitis patients from normal control with sensitivity 100% and specificity 100% this is in consistent with daiuto et al. (29), zia et al.,(28). the second parameter was mmp-8 with area under rock (0.999) with sensitivity 100% and specificity 95% this is in consistent with mantyla et al. and miller et al. (30,31), and in agreement with miller et al. (32). the third one is esr with area under rock (0.882) and according to my knowledge that there is no previous study that uses esr in diagnosis of periodontitis. it is hypothesized that possibly daily episodes of a bacteremia originating from periodontal lesions are the cause for the changes in systemic markers in periodontitis. in conclusions crp and mmp-8 are considered a useful test in predicting periodontitis, and in type 2 diabetic patients, there was a relationship between metabolic control of diabetes and severity of periodontal disease and further studies are needed with larger sample size to see the effect of having diabetes on progression of periodontal disease. references 1. engelgau mm, geiss ls, saaddine jb et al. the evolving diabetes burden in the united states. ann intern med 2004; 140: 945-50. 2. graves dt, liu r, alikhani m et al. diabetesenhanced inflammation and apoptosis – impact on periodontal pathology. j dent res 2006; 85: 15–21. 3. american academy of periodontology. diabetes and periodontal diseases. committee on research, science and therapy. j periodontol 2000; 71: 664-78. 4. pradhan ad, ridker pm. do atherosclerosis and type 2 diabetes share a common inflammatory basis? eur heart j 2002; 23: 831-4. j bagh college dentistry vol. 25(1), march 2013 evaluation of salivary oral diagnosis 66 5. diana m. isaza-guzman,carolina arias-osoria et al. salivary level of matrix metalloproteinase (mmp)-9 and tissue inhibitor of matrix metalloproteinase (timp)-1: apilot study about the relationship with periodontal status and mmp-9 gene promoter polymorphism. arch oral biol 2011; 56(4): 401-11. 6. miller cs, king cp jr, langub mc et al. salivary biomarker of existing periodontal disease: a cross sectional study. j am dent assoc. 2006; 137(3): 3229. 7. william v, giannoblle, thomas b, janet s, et al. saliva as a diagnostic tool for periodontal disease: current state and future directions periodontology 2000 2009; 50; 52–64. 8. daiuto f, ready d, tonetti ms. periodontal disease and c reactive protein-associated cardiovascular risk. j periodontal res 2004; 39: 236–241. 9. teng yt, sodek j, mcculloch ca. gingival crevicular fluid gelatinase and its relationship to periodontal disease in human subjects. j periodontal res 1992; 27: 544–552. 10. christodoulides n, mohanty s, miller cs, et al. application of microchip assay system for the measurement of c-reactive protein in human saliva. lab chip 2005; 5: 261–269. 11. abraham. hemoglobin a1c by isoelectric focusing. 1982; 28 (1): 9-12. 12. ramfjord sp. indices for prevalance and incidence of periodontal disease. j periodontal 1959; 30: 51-9. 13. neelima s. rajhans, ramesh m. kohad et al. a clinical study of the relationship between diabetes mellitus and periodontal disease. j indian soc periodontol. 2011; 15(4): 388–392. 14. oliver rc, tervonen t. diabetes a risk factor for periodontitis in adults? j periodontal 1994; 65: 530–8. 15. moder kg. use and interpretation of rheumatologic tests: a guide for clinicians. mayo clin proc 1996; 71(4); 391-396. 16. fernando llambés , francisco-javier silvestre et al. effect of periodontal disease and non surgical periodontal treatment on c-reactive protein. evaluation of type 1 diabetic patients. med oral patol oral cir bucal. 2012; 17(4): e562–e568. 17. forner l, larsen t, kilian m, holmstrup p. incidence of bacteremia after chewing, tooth brushing and scaling in individuals with periodontal inflammation. j clin periodontol. 2006; 33: 401-7. 18. costa pp, trevisan gl , macedo go et al. salivary interleukin -6, matrix metalloproteinase -8, and osteoprotegrin in patients with periodontitis and diabetes . j periodontal 2010; 81(3): 384-91. 19. khalid almas, mohammed al-qahtani, marzouk alyami et al. the relationship between periodontal disease and blood glucose level among type ii diabetic patients. j contemp dent pract 2001; 15;2(4):18-25. 20. seppala b, ainamo j. a site-by-site follow-up study on the effect of controlled versus poorly controlled insulin dependent diabetes mellitus. j clinical periodontol 1994; 21: 161-5. 21. khansa taha ababneh1, zafer mohammad faisal et al. prevalence and risk indicators of gingivitis and periodontitis in a multi-centre study in north jordan: a cross sectional study. bmc oral health 2012; 12: 1. 22. ali saad thafeed alghamdi . esr is marker effect of chronic periodontal diseases on erythrocytes sedimentation rate. egypt dental association 2009; 55 23. lee, w., s. aitken, j. sodek, and c. a. mcculloch. evidence of a direct relationship between neutrophil collagenase activity and periodontal tissue destruction in vivo: role of active enzyme in human periodontitis. j periodontal res 1995; 30: 23–33. 24. raquel romanelli, sabrina mancini, carol laschinger et al. activation of neutrophil collagenase in periodontitis. infect immun 1999; 67(5): 2319. 25. uitto vj, suomalainen k, sorsa t. salivary collagenase. origin, characteristics and relationship to periodontal health. j periodontal res 1990; 25: 135— 142. 26. overall, c. m., j. sodek, c. a. mcculloch, and p. birek. evidence for polymorphonuclear leukocyte collagenase and 92-kilodalton gelatinase in gingival crevicular fluid. infect. immun 1991; 59: 4687–92. 27. herr ae, hatch av, throckmorton dj et al. microfluidic immunoassays as rapid saliva-based clinical diagnostics. proceedings of national academy of sciences usa 2007; 104: 5268–73. 28. zia a, khan s, bey a, gupta nd, mukhtar-un-nisar s. oral biomarkers in the diagnosis and progression of periodontal diseases. biology and medicine 2011; 3: 45-52. 29. daiuto f, ready d, tonetti ms. periodontal disease and c reactive protein-associated cardiovascular risk. j periodontal res 2004; 39: 236–241. 30. mantyla p, stenman m, kinane df et al. gingival crevicular fluid collagenase-2 (mmp-8) test stick for chairside monitoring of periodontitis. j periodont res 2003; 38: 436–9. 31. mantyla¨ p, stenman m, kinane d et al. monitoring periodontal disease status in smokers and non-smokers using a gingival crevicular fluid matrix metalloproteinase-8 (mmp-8) specific chair-side test. j periodont res 2006; 41: 503–512. 32. miller cs, king cp jr, langub mc et al. salivary biomarker of existing periodontal disease: a cross sectional study. j am dent assoc 2006; 137: 322-9. j bagh college dentistry vol. 25(1), march 2013 evaluation of salivary oral diagnosis 67 table 1: the difference in mean/median of selected variables between subjects with severe attachment loss (>5.1) and that with less severe among diabetics with periodontitis. severe attachment loss (>5.1) less severe(<=5.1) (n=11) severe (>5.1) (n=9) p value age in years 0.1[ns] range (31 58) (42 55) mean 42.8 47.9 sd 7.7 4.8 se 2.3 1.6 r=0.378 p=0.1[ns] blood esr (mm/hour) 0.41[ns] range (1 48) (13 62) mean 27.4 33.8 sd 17.7 15.7 se 5.3 5.2 r=0.023 p=0.92[ns] crp (c-reactive protein) pg/ml 0.13[ns] range (3144 6487) (3384 33236) median 4693 5562 interquartile range (3384 5864) (4148 8493) r=0.179 p=0.45[ns] mmp-8 (matrix metallo proteinase-8) ng/ml 0.24[ns] range (118 299) (221 322) mean 234.3 259.6 sd 51.2 39.5 se 15.4 13.2 r=0.186 p=0.43[ns] fasting serum glucose conc. (mg/dl) 0.1[ns] range (110 365) (135 389) mean 184.5 259.1 sd 87.4 103.0 se 26.4 34.3 r=0.42 p=0.07[ns] hb a1c % (glycosylated hb) range (4.2 7.9) (5.6 8.9) mean 5.9 7.4 sd 1.4 1.0 se 0.4 0.3 r=0.43 p=0.06[ns] j bagh college dentistry vol. 25(1), march 2013 evaluation of salivary oral diagnosis 68 table 2: the difference in mean/median of selected variables between subjects with severe attachment loss (>5.1) and that with less severe among non-diabetics with periodontitis. severe attachment loss (>5.1) less severe (<=5.1) (n=10) severe (>5.1) (n=10) p value age in years 0.66[ns] range (35 55) (30 55) mean 45.1 46.6 sd 5.9 8.8 se 1.9 2.8 r=0.032 p=0.89[ns] blood esr (mm/hour) 0.86[ns] range (10 60) (12 80) mean 34.5 36.0 sd 14.2 21.7 se 4.5 6.9 r=0.157 p=0.51[ns] crp (c-reactive protein) pg/ml 0.62[ns] range (3144 37221) (3886 44521) median 4696.5 4834.5 interquartile range (4148 8145) (4417 7803) r=0.287 p=0.22[ns] mmp-8 (matrix metallo proteinase-8) ng/ml 0.14[ns] range (199 299) (217 369) mean 243.0 274.1 sd 34.2 53.5 se 10.8 16.9 r=0.528 p=0.017 table 3: roc area measuring the validity for selected parameters when used to diagnose periodontitis differentiating it from healthy controls. roc area p crp (c-reactive protein) pg/ml 1.000 <0.001 mmp-8 (matrix metallo proteinase-8) ng/ml .999 <0.001 blood esr (mm/hour) .882 <0.001 figure 1: roc curve showing the trade-off between sensitivity and 1-specificity for selected parameters when used to diagnose periodontitis differentiating it from healthy controls. j bagh college dentistry vol. 25(1), march 2013 evaluation of salivary oral diagnosis 69 table 4: roc area measuring the validity for selected parameters when used to predict dm among cases with periodontitis. crp (c-reactive protein) pg/ml .627 0.17[ns] mmp-8 (matrix metallo proteinase-8) ng/ml .655 0.09[ns] blood esr (mm/hour) .533 0.72[ns] figure 2: roc curve showing the trade-off between sensitivity and 1-specificity for selected parameters when used to predict dm among cases with periodontitis. 20. rania f.doc j bagh college dentistry vol. 27(4), december 2015 abo blood type pedodontics, orthodontics and preventive dentistry 125 abo blood type in relation to caries experience and salivary physicochemical characteristic among college students at al-diwania governorate in iraq rania f. kadhum, b.d.s. (1) ban sahib diab, b.d.s., m.sc., ph.d. (2) abstract background: (abo) blood type have an effect on general health including oral health as salivary physicochemical characteristics differ among different type of blood and as consequence these affect the severity of dental caries. the aim of the present study is to assess of the prevalence of caries experience among different blood type in relation to salivary physicochemical characteristic. materials and methods: two hundred and fifty females' college students in al-qadisyia university aged 18 years old were selected on random basis; they were divided to four groups according to their blood type, dental experience was diagnosed and recorded according to dmfs index (mülemman, 1976), this allows recording decayed lesion by severity. a sub sample was pooled for salivary analysis. results: in the present study the blood type o was more common followed by b and a, whereas the less common was ab type, caries experiences (dmfs) and ds component were found to be statistically significant among different blood types. the most sever grade of dental caries d3 and d4 were higher among type ab and lowest sever grade d1 among b blood type. while salivary flow rate significantly differ among differ blood type, viscosity higher but not significant among type ab. while salivary concentration of calcium and total protein were differ but not significant, opposite to alkaline phosphatase which was highly significant among different blood types. conclusions: abo blood type has an effect on salivary physical and chemical characteristic of saliva as effect on prevalence of caries. key words: abo antigen, abo blood group, dental decay. (j bagh coll dentistry 2015; 27(4):125-131). introduction in spite of a knowledge explosion in cariology science, dental caries still remains a misunderstood phenomenon by the clinicians. in order to effectively use the wide range of preventive and management strategies, it is imperative to look beyond those black and white spots that manifest on the tooth surfaces. one of the most important factors which influence the development of dental caries is saliva. the physicochemical properties of saliva like ph, buffering capacity, salivary flow rate, concentration of various components like proteins, calcium and antioxidant defense system play a major role in the development of caries (1). dental caries is one of the most significant health problems facing all ages (2). this could be due to the cumulative irreversible nature of dental caries (3,4). saliva is one of the most important factors in regulating oral health, with flow rate and composition changing throughout development and during disease. saliva can affect incidence of dental caries in four general ways, firstly as a mechanical cleansing, secondly by reducing enamel solubility by means of calcium, phosphate and fluoride, thirdly by buffering and neutralizing the acids produced by cariogenic (1)master student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. organisms and finally by anti-bacterial activity (5), salivary alkaline phosphatase; which may balance enamel remineralization (6), as well as buffering capacity; that may affect alkaline phosphatase function and the quantity of ion activity product for hydroxyapatite (7,8). in 1900, landsteiner first described the existence of serologic difference between individuals, and classified people into four groups depending on whether their rbc cell membrane contained agglutinogen (antigens). the most important blood-typing system, the abo system, which comprises of four blood types: a, b , ab and o. blood group o erythrocytes have no true antigen, but blood serum of o-type individuals carries antibodies to both a and b antigens. type a and b erythrocytes carry the a and b antigens, respectively, and make antibodies to the others. type ab erythrocytes do not manufacture antibodies to other blood types because they have both a and b antigens (9). the distribution patterns of abo system are complex around the world. some variation may even occur in different areas within one small country (10). the blood group distribution also shows variety according to races. in previous iraqi studies (11,12), they found that the o blood type was more common followed by blood type b and a, and the least prevalent was ab. in the last 20 years, there has been increasing evidence that blood groups have a function and play a biological role, they have been used as j bagh college dentistry vol. 27(4), december 2015 abo blood type pedodontics, orthodontics and preventive dentistry 126 genetic markers in studies of their associations with various diseases (13,14). this biological role often does not relate to the red cell, but to the presence of chemical moities on other cells that were initially identified as red cell antigens. antigens, first identified on rbcs, are now known to be important as receptors and ligands for bacteria, parasites and immunologically important proteins and differences in abo blood groups are determined by antigens in the outer carbohydrate coating (glycocalyx) of erythrocytes(15). immunohistochemical studies have demonstrated the presence of a/b antigens on spinous cells in the non-keratinized oral epithelium of blood group a and b persons, where basal cells express precursor structures and the more-differentiated spinous cells express the a or b antigens. blood group o persons who do not have the a and b gene-coded glycosyl transferase express a fucosylated variant (ley) of the precursor structure(16,17). because these antigens are present in most tissues, differences in the glycocalyx expressed by cells might elicit differing responses in biomedical phenomena in other diseases or disorders (18-20). anthropologists have used the abo blood types as a guide to the development of modern humans. many diseases, particularly digestive disorders, cancer, and infection, show preferences among the abo blood types (21-23). the history of investigations regarding the relationship between blood groups and dental diseases goes back to 1930 (24). early investigation by aitchison and carmichael (25) studied the distribution of blood groups within two groups, one of whom were the random patients attending the dental hospital and the other consisting of cases with rampant caries they found that people with o blood type have higher dental caries experiences, while people with a blood type was the lowest, also o’rark and lyschon (26) found a statistical significance regarding the relation blood type and caries history. while janghorbani (27) showed that dental caries prevalence of 427 soldiers of military base in kerman with 19 years, the mean value for dmf index was the lowest in b blood group and the highest in ab blood group. also, secretors of blood group a had the lowest numbers of cavities (25-28). on the contrary, barros and witkop, on a large group of chileans, found no association between the d.m.f scores for caries and abo blood groups (29). to the best of our knowledge, no previous study has been performed yet in iraq to evaluate the relationship between the physic-chemical characteristic of saliva and caries experience among different blood group; therefore, this study was conducted. materials and methods study population: in the present study, 250 female students of first grade in al-qadisyia university at al – diwania governorate with age 18 years old were selected randomly and participated in the present study. respecting the previous studies (8,30), those who had positive history of illnesses or treatments which could cause alteration in salivary rate and composition, were excluded from the study. informed consent was obtained from each individual, before any data collection and examination of the oral health status then the blood samples were taken by a sterile finger prick with a disposable needle. the blood grouping examination was done by the slide method (13). dental examination: an examiner was trained and informed with who instructions on oral examination, the examination was done while the students sitting on the dental unit, plain mouth-dental mirrors (no.4). sickle-shaped dental explorers were used. teeth lost or restored due to trauma, orthodontic treatment or aesthetic reasons were not considered as missed or filled teeth. decayed (d), missed (m) and filled (f) teeth index were detected following the criteria described by mülemman (1976), this allows recording decayed lesion by severity (31). collection of saliva samples: the stimulated whole saliva was collected under standard conditions, following the instructions cited by tenovuo and lagerlöf(32). to reduce circadian effect, saliva collection was done between 9 and 11am after 2 hours with subjects being prevented of eating, drinking or brushing. each individual was asked to chew apiece of arabic gum (0.5-0.7gm) for one minute, then removed all saliva by expectoration, after that chewing was continued for five minutes with the same piece of gum and saliva collected in a sterile screw capped bottle. the flow rate of the saliva was determined according to jensen et al. (33). flow rate (ml/min) = volume (ml)\ time (min). then each salivary sample was separated in two parts, one for the measurements of viscosity of saliva, which was done by measuring the volume rate of flow through a tube of viscometer is known ostwald viscometer as cited by stokes and davies (34). other part was centrifuged at 3000 r.p.m for 10 minutes then the clear supernatants was separated j bagh college dentistry vol. 27(4), december 2015 abo blood type pedodontics, orthodontics and preventive dentistry 127 by micropipette and then stored at (-20°c) in a deep freeze till the time of biochemical analysis. biochemical analysis of saliva: target salivary elements were alkaline phosphatase, calcium and total protein analyzed at private licensed laboratory salivary alkaline phosphatase, calcium and total protein analyzed by flame atomic, using sp-300 spectrophotometer (optima, japan), following standardized procedure. instrumental settings were performed according to instrumental manufacture's specifications. frozen saliva samples were allowed to thaw and come to room temperature. thereafter, they were subjected to biochemical analysis. alkaline phosphatase in saliva was estimated by using alkaline phosphatase kit, which functions on the basis of modified kind & king’s method(35). the measurement of calcium in the sample is based on formation of color complex between calcium and o-cresolphtaleir in alkaline mediurn (36). determination of total proteins in saliva was done by using human total protein liquicolor kit (spectrum-s.a.e) (37). statistical analyses: a computerized program, the statistical package for social science (spss), version (13) was used to calculate the statistics. the analysis of data included, tests for normal distribution, statistical tests: non-parametric kolmogorovsmirnov test. the collected data was tabulated and statistically analyzed by: descriptive data analysis frequencies, percentages, mean, standard deviation for normally distributed data and median, mean rank for not normally distributed data, tests for differences applied were anova test significant difference (lsd) test for normally distributed data. kruskal-wallis h and mannwhitney utest for not normally distribution. results in the present study the o blood type was found to be more common (36.8%), followed by b type (28%) and a type (26%) whereas the less common was ab type (9.2%) as shown in (table 1). results revealed that dmfs (median and mean rank) was statistically significant different among blood type (chi-square =8.091, p–value = .044), further analysis showed that the students with type b had significantly lower dmfs value than students with other blood types. the same result shown concerning decayed ds component of dmfs as the result illustrates a significant differences among students with different types. further analysis showed that the students with type b had significantly lower ds value than students with type ab (z= 2.424, pvalue= 0.015) and type o (z=2.306,p-value = 0.012). the severity of the dental caries represent by grades of decayed fraction d1-d4(median and mean rank) among students with different blood type are illustrated in table-3 that shows the higher mean rank was d2 grade among students with ab and o types while among students with a and b types the higher mean rank was grades d3and d1 respectively. however concerning differences among different blood types the data of the present study showed that the only statistically significant difference was concerning d2 (chisquare=14.423,p-value= 0.002) and d3 (chisquare=10.739,p-value= 0.013).further analysis showed that the students with type b had significantly lower d2 value than students with type ab (z=2.424,p-value= .015) and type o(z= 2.306, p-value= .021). on the other hand although the mean rank value of most sever grade of dental caries d3 and d4 were higher among students with type ab and lowest sever grade d1 among students with b blood type all these differences were not significant. salivary flow rate (ml\min) and viscosity (poise) among students with different blood type (mean± s.d) are shown in table -4. this table shows that the mean value of salivary flow rate was found to be higher among students with type b and the lower among students with type ab; however the data of present study showed that the mean salivary flow rate was highly statistically significant differ (f= 9.805, p-value= .000) among different blood type, further analysis showed that the mean salivary flow rate among students with blood type ab were significantly lower than other blood types. the viscosity was found to be higher among students with type ab and lower among students with type a and b, however this differences was statistically not significant. table 5 illustrates the concentration of calcium (mg/dl), alkaline phosphatase (u/l) and total protein (g/l) in saliva among students with different blood type. the present study found that the mean concentration of calcium (mg/dl) higher but not significant among type ab (4.18 ± .655) than other blood types. the same figure found concerning the salivary concentration of total protein (g/l) as the concentration was higher but not significant among students with type a (1.22± .284) than students with other blood types. on the other hand other picture found concerning alkaline phosphatase as the differences among students with different blood types was j bagh college dentistry vol. 27(4), december 2015 abo blood type pedodontics, orthodontics and preventive dentistry 128 highly significant (f=6.495, p-value =.001). further analysis showed that the mean salivary concentration of alkaline phosphatase was significantly higher among students with type ab than type a (mean difference=.943*,p-value = .000) and type b (mean difference=.1.004*,p-value = .000) as well as type o (mean difference=.561*,p-value = .32). table 1: frequency distribution of abo blood type among students blood group no % a 65 26 b 70 28 ab 23 9.2 o 92 36.8 table (2): dental caries experience represented by (dmfs) among students with different blood type (median and mean rank) blood type dental caries experience ds ms fs dmfs a median 5.000 0.000 0.000 6.000 mean rank 129.2 124.8 116.6 122.7 b median 3.000 0.000 0.000 5.000 mean rank 106.3 125.1 123.8 108.0 ab median 7.000 .000 .000 9.000 mean rank 148.7 124.7 128.3 147.6 o median 5.000 0.000 0.000 7.000 mean rank 131.7 126.5 132.3 135.2 test statistics chi-square 8.265 .083 3.834 8.091 p -value 0.041 0.994 0.280 0.044 table (3): severity of dental caries represented by grades of d1-d4 (median& mean rank) among students with different blood types blood type dental caries experience and severity d1 d2 d3 d4 a median 0.000 2.000 0.000 0.000 mean rank 119.59 129.92 132.54 123.06 b median 1.500 2.000 0.000 0.000 mean rank 135.67 99.26 120.46 125.06 ab median 1.0000 4.0000 0.000 0.000 mean rank 130.30 148.87 138.54 132.43 o median 0.000 4.000 0.000 0.000 mean rank 120.73 136.49 121.10 125.82 statistical difference chi-square 2.745 14.423 10.739 0.712 p -value 0.433 0.002 0.013 0.870 table (4): salivary flow rate (ml\min) and viscosity (poise) among students with different blood type. blood type saliva physical proprieties flow rate viscosity a mean 1.67 0.02 ±sd 0.52 0.01 b mean 1.79 0.02 ±sd 0.36 0.01 ab mean 1.19 .044 ±sd 0.25 0.03 o mean 1.35 0.04 ±sd 0.42 0.11 statistical difference f 9.81 1.81 sig 0.00 0.15 j bagh college dentistry vol. 27(4), december 2015 abo blood type pedodontics, orthodontics and preventive dentistry 129 table (5): salivary concentration of calcium (mg/dl), alkaline phosphatase (u/l) and total protein (g/l) among students with different blood type. blood type salivary constituents calcium (mg/dl) alkaline phosphatase (u/l) total protein (g/l) a mean 4.02 3.52 1.22 ±sd 0.73 1.02 0.28 b mean 3.93 3.46 1.16 ±sd 0.85 0.89 0.19 ab mean 4.18 4.46 1.14 ±sd 0.66 0.59 0.20 o mean 3.66 3.89 1.17 ±sd 0.49 0.65 0.19 statistical difference f 1.940 6.49 0.54 sig 0.13 0.001 0.66 discussion the present study aims to find the effect of many variables and elements on the grades of caries severity among different blood type, however the data revealed that the dmfs (median and mean rank) was statistically significantly differ among blood type; this association can be due to that various blood group antigens acting as receptors for infectious agents associated with dental disease. this broad correlation between oral disease and abo blood group also points toward susceptibility of the subjects with certain blood groups to oral disease (38), further analysis the data of present study showed that the students with type b had significantly lower dmfs value than students with other blood type and this in agreement with previous study that found dmf index was the lowest in b blood type and the highest in ab blood type, however no statistically significant difference was observed (27). while disagree with earlier study, that found the individual of blood group a had the lowest numbers of cavities (28). this difference may be attributed to variation in sample size and variation in the methods of measuring dental caries in addition to that geographical, racial and ethnic condition which effected on blood type distribution (13). other researchers failed to find this increased risk (29). the decreased caries experience among student with blood type b and the increase among type ab could be attributed to many findings that illustrated by the data of the present study, these include: significantly increase in salivary flow rate among students with type b and significantly decreased among students with type ab than other types. the salivary flow rate plays an important role in relation to dental caries because the washing action of saliva as well as its protective constituents increased with increase flow rate (39,40). the protective factor of salivary flow rate was also found in the present study by the negative relation between flow rate and caries experience as well as in the previous studies (41,42), however others found opposite (43-45). while viscosity was found to be higher among students with type ab and the lower among students with type a and b, however this differences was statistically not significant, that a positive correlation was detected between the viscosity of saliva and the number of decayed, missing, and filled teeth. patients with thick, ropy saliva invariably had poor oral hygiene and the teeth appear to be covered by stain or plaque, and the rate of dental caries ranged from greater than average to rampant caries (46). other explanation could be the significantly increase concentration of salivary alkaline phosphatase among students with type ab than other types, higher alkaline phosphatase activity was found to be associated with increase caries experience because variations in alkaline phosphatase levels causes changes in phosphate levels which lead to initiation and progress of caries(47,48), this positive association was also found in the present study. while the decreased of salivary total protein among students with type ab, this may explain the anti-caries effect of total protein as increased concentration may give a protective role. in humans, after eruption of teeth there is no direct effect of protein on tooth susceptibility to caries, theoretically protein adsorbs on tooth surface and could decreases dental caries risk, but precise evidence is lacking(48) and this disagree with other studies(50,51). while leone and oppenheim in 2001 reported that fourteen studies examined the correlation between caries and salivary proteins and found no correlation between them (52). as conclusions; 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4(3-4): 32533. 51ahmadi-motamayel f, goodarzi mt, hendi ss, abdolsamadi h, rafieian n. jdoh j dentistry and oral hygiene 2013; 5(4): 35-9. 52 leone cw, oppenheim fg. physical and chemical aspects of saliva as indicators of risk for dental caries in humans. j dent educ2001; 65(10):1054-62. j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 103 immediate implant placement in fresh extraction socket mohammed majid abdulmunem, b.d.s. (a) jamal abid mohammed, b.d.s., m.sc. (b) abstract background: in the traditional protocol, the patient should wait after extraction up to six months to place the dental implant in healed bone, this waiting time accompanied by varying degrees of alveolar bone changes. in order to overcome these problems, immediate implant placement in the fresh extraction socket was introduced. the aim of this study was to evaluate the outcome of the immediate implant placement utilizing resonance frequency analysis (rfa) to quantify implant stability and osseointegration. materials and methods: a total of (23) patients participated in the study, receiving (44) implants placed in the sockets of teeth indicated for extraction. clinical and radiographic preoperative assessment was accomplished for each patient, β-tcp (combined with collagen membrane) was used to fill gaps ≥ (2 mm) and to repair bone defects. implant stability quotient (isq) values were measured for the implants at baseline and at 16 weeks. postoperative clinical and radiographic evaluation was applied for each patient. results: a total of (22) patients received (41) implants completed the follow-up period, all these implants survived (100% survival rate) with no signs and symptoms of failure. the mean of isq value at baseline was (65.32±9.50), the mean of isq value at 16 weeks was (69.78±7.15), paired samples statistic showed high significant increase in the implant stability (p<0.01). application of guided bone regeneration (gbr) showed no significant difference on isq value at baseline and at (16 weeks), but isq values increased significantly in gbr cases during the healing period. conclusions: immediate implant placement is a predictable treatment approach; it has the benefit of reducing treatment time and the numbers of surgical procedures when careful preoperative examination and appropriate intraoperative protocol is applied. key words: immediate implant placement, survival rate, rfa. (j bagh coll dentistry 2016; 28(4):103-110) introduction immediate implant placement is the insertion of dental implant into the extraction socket, at the course of surgical removal of teeth to be replaced. the initial report in the literature was published in 1976 by schulte (1). the concept was reintroduced in 1989 by lazzara, who explained this method by three case reports (2). the immediate implant placement protocol was validated later by gelb, who reported survival rate of 98% in fifty consecutive cases followed over three years.(3) since then several animal and human studies, case reports, and randomizes controlled studies furthered the science of this treatment modality and indicated that immediate implant placement can be as successful as delayed implant protocol whenever correct surgical strategies followed (4). this concept have the advantages of preserving alveolar ridge contours, reducing treatment visits and costs, and improve patient psychological insight about treatment, on the other hand immediate implant have a pronounced outcome related to difficulties in obtaining primary implant stability and allocating final implant position (2,4,5). (a) m.sc. student, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (b) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. papers described different terms to identify timing of implant placement such as: “immediate,” “early,” “recent,” “delayed,” “late,” and “mature” (6,7). new classification system of implant placement was produced based on the clinical outcome of wound healing rather than on descriptive terms or rigid time frame (6). this classification was slightly modified in 2008 by chen and buser and involve classify the timing into four types:type 1: placement of implant at the day of extraction within the same surgical procedure i.e. there is no healing of the bone or soft tissue, which is familiarly known as immediate implant placement, type 2: implant placed after soft tissue healing, but still there is no clinically significant bone fill within the socket, typically 4-8 weeks after extraction, type3: implant is placed after significant clinical and/or radiographic bone fill of the socket, this occur 12-16 weeks after extraction, type4: implant is placed into fully healed socket, and this performed more than 6 months after extraction (7). when the implants are initially inserted into the alveolar bone, they become stable depending on the mechanical contact between the implant and the bone, still now there is no actual biological connection at implant bone interface, this initial stability named as primary stability j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 104 and it is a prerequisite and a predictor for successful osseointegration (8). as osseointegration begins, a biological connection will be formed, which in turn leads to biological stability. resonance frequency analysis is an assured method that gives researchers the ability to quantify implant stability both initially at implant placement and during subsequent follow up periods (9). materials and methods this clinical study conducted at the department of oral and maxillofacial surgery/college of dentistry/university of baghdad, during the period from november 2014 to september 2015. the sample included patients indicated for implant treatment to replace single or multiple hopeless maxillary and mandibular incisors, canines, and premolars teeth, with implant placement into the extraction socket at the same time of extraction, by means of two-stage implant placement protocol. inclusion criteria 1. patients age ≥ 18 years old. 2. patients with a single or multiple teeth indicated for extraction in the area of maxillary and mandibular incisors, canines, and premolars. 3. availability of bone > 2 mm apical to the root apex to provide adequate primary implant stability. 4. patients with a good oral hygiene to be candidate for implant success. exclusion criteria 1. radiotherapy, uncontrolled diabetics, heavy smokers (>20 cigarettes/day), immunocompromised patients, and other local and systemic diseases, drugs, and habits that may jeopardize implant success. 2. patients with medical conditions that preclude any surgical intervention such as patients with bleeding disorders or recent myocardial infarction. 3. pregnant women. 4. close proximity of vital structures such as maxillary sinus and mental foramen that make impossible to engage adequate bone apical to the extracted tooth to attain primary implant stability. 5. sites showing severe bone destruction. 6. signs of acute infection or pus discharge. 7. active advanced periodontal disease, and bad oral hygiene. clinical and radiographical assessment a thorough history was taken from all the patients who were asked about their chief complaint, past treatment of the tooth/teeth under concern such as trauma, failed endodontic treatment, failed prosthesis, and endodontic surgery. clinical examination proceeded with thorough general extra-oral and intraoral examination, with special attention to the teeth that were planned to be extracted, these were carefully examined for the presence of any signs of acute infection such as pain, pus discharge, discharging sinus and swelling. all patients obtained preoperative opg (fig.1), and periapical radiograph of the accused tooth (fig.2). figure 1: diagnostic preoperative panoramic radiograph showed multiple destructed teeth at the anterior maxillary area indicated for extraction and to be replaced by dental implants. figure 2: diagnostic preoperative periapical radiograph for the same patient that showed finer details for teeth no. (7, 8, 9, 10, and 11). surgical procedure prior to surgery, the patient was instructed to rinse his/her mouth with chlorhexidine 0.12 % mouth-wash for 30 seconds, then the skin around the mouth was disinfected with a sterile gauze swapped by povidone-iodine solution. surgery was performed under local anesthesia with (lidocaine 2%, adrenalin 1:100000, 2.2 ml cartridge, septodent, france), by block and/or infiltration technique on both the facial and palatal/lingual sides. j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 105 the accused tooth was extracted carefully utilizing dental forceps using a gradual rotational force in clockwise and counterclockwise movement, elevator (when needed) was used carefully to avoid crushing and damage to the buccal bone. the socket was then curetted by appropriate surgical curette to remove the remnant of granulation tissue, then the extraction site was thoroughly irrigated by normal saline. three-sided full thickness mucoperiosteal flap was reflected, the facial bone inspected for the presence of bone defect or periapical lesion. utilizing the measurement provided by radiograph and the original length of the root of the extracted tooth (that was measured directly by endodontic file and ruler) (fig.3), then an implant with appropriate length and diameter was selected. figure 3: measurement of extracted root length by endodontic file. drilling started by first pilot drill (dentium co., korea) with the extracted root direction in mandibular anterior and premolar sites (fig.4 a), or at the conjunction of the middle and apical thirds of the palatal wall of extraction socket in the maxillary anterior sites (fig.5 b). figure 4: drilling in: a-anterior mandible, b-anterior maxilla. sequential drilling continued until the planned size was reached. the implant fixture (dentium co., korea) was inserted at or just below the crestal bone level. measurement of the implant stability was performed using osstelltm isq (goteborg, sweden, 4th generation). a smart peg was placed into the implant body. the transducer probe was directed at the top of the smart peg with a distance of approximately (2 mm) and held stable until the device beeped and displayed the isq value. the measurements were taken twice in bucco-lingual and mesio-distal directions (fig.5 a), the mean of the two measurements was represented the isq value of the implant at base line record. the cover screw was than inserted over the implant fixture (fig.5 b). figure 5: a-isq measurement, b-cover screw placement. in cases with bone defects and/or implantbone gaps (≥2 mm), β-tcp resorbable bone substitute (zizine laboratoire, freance), and autogenous bone (if available) harvested from the implant preparation site were mixed to fill these gaps and defects. periosteal slitting at the deepest area of the flap with multiple incisions in the periosteum if required was performed to lengthen the flap and retrieve autogenous blood to the bone grafting material. the absorbable collagen membrane (genoss co., korea) was trimmed and adapted to cover the defect with at least 2 mm extension toward the palatal side for good fixation and to cover the implant completely. the surgical wound was finally closed by simple interrupted suture using 3/0 non-resorbable black silk suture (dynek, australia) (fig.6). figure 6: bone defects repaired by β-tcp and collagen membrane. following surgical procedure, the patients were instructed to apply cold pack over the surgical area extra-orally for the rest of the first day, the patients also were instructed to avoid eating at the site of surgery, eating warm diet and rinsing the mouth on the day of surgery. the patients were medicated by amoxicillin cap. 500 mg t.i.d., and metronidazole tab. 500 mg t.i.d., the treatment continued for 5 days. in b a b a j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 106 patients allergic to penicillin azithromycin tab. 500 mg was prescribed once daily for 3 days. paracetamol tab. 500 mg prescribed as analgesic when needed. the patients were instructed to rinse with 0.12% chlorhexidine mouthwash b.i.d. for two weeks starting from day after surgery, in cases with spontaneously exposed cover screw the mouthwash continued for the rest of the follow up. sutures were removed 10-14 days after surgery. follow up and data collection the patients were evaluated at 2, 8, 16 weeks for clinical, radiographic assessment and stability measurement. the implants were evaluated clinically to detect implant mobility and check the presence of signs and symptoms of infection such as pus discharge or draining fistula, pain, and swelling. periapical radiograph was taken to the implant site immediately after surgery, at 8 weeks, and at 16 weeks to show any signs of bone resorption and peri-implant radiolucency (fig.7), opg was taken at the 16 weeks for all cases (fig.8). figure 7: three postoperative periapical radiograph taken at: aimmediately after surgery, bat 8 weeks, cat 16 weeks. figure 8: postoperative opg of the same patient in figure 1 taken at 16 weeks. at 16 weeks implants were exposed using soft tissue punch (dentium co., korea), isq value measured by ostell (goteborg, sweden, 4th generation) in the same way as recorded during surgery, the examiner was blinded to the isq value of the previous visit but not blinded about the placement approach. a suitable healing abutment (gingival former) was placed at the implant top, and then impression taken for final prosthesis construction (fig.9). figure 9: agingival formers in place at the top of implants during second stage surgery. bfinal prosthesis. statistical analysis two independent sample t-test, paired t-test, and pearson correlation (r) were the statistical methods used to analyse the data. the level of significance tested according to the p-value, were: p>0.05 (not significant), p<0.05 (significant), p<0.01 (highly significant). the analyses were accomplished using two computer software programs: statistical package for social sciences (spss version 18) and microsoft office excel 2007. results twenty two patients (10 males and 12 females), aged between (32-66 years old), who received (41) implants and completed the followup visits, were included in the data record. the implants distributed according to arches as follow: (87.8%) of implants were placed in the maxillary arch and (12.2%) of implants were placed in the mandibular arch. implant diameter (3.8 mm) was used in (65.85%) of cases, implant diameter (3.4 mm) was used in (26.82%) of cases, and implant diameter (4.3 mm) was used in (7.33%) of cases. implant length (14) was used in (58.53%) of cases, implant length (12) was used in (39%) of cases, and implant length (10) was used in one case only. all the implants (41 implants) survived during the follow-up period (100% survival rate). the mean isq value and standard deviation at base line was (65.32±9.50 isq) range (46.5-81 isq), the mean isq value and standard deviation at 16 weeks was (69.78±7.15 isq) range (46.5-81 isq) (fig.10), paired t-test showed a highly significant increase in the isq value from the primary stability at baseline to the secondary stability at 16 weeks (p<0.01). a b c a b j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 107 figure 10: mean of primary and secondary stability. the stability at baseline was distributed as follow: low <60 isq (29.3%), medium >60 and <70 isq (22%), high stability ≥70 (48.7%). at 16 weeks the stability distribution was as follows: low <60 isq (7.3%), medium >60 and <70 isq (39%), high stability ≥70 isq (53.7%). twenty six implants, which represent (63.4%) of implants, were required bone substitute and membrane (gbr) to fill gaps ≥ 2 mm and bone defects. statistical analysis showed no significant difference between cases (with gbr) vs (without gbr) regarding mean isq value neither at baseline nor at 16 weeks (fig.11). paired t-test showed high significant increase in the isq value of gbr cases during the healing period. thirteen implants, (31.7%) of implants were spontaneously exposed during the healing period. statistical analysis showed no correlation between spontaneous early implant exposure and gender of the patient, using gbr, and presence of bone dehiscence in the extraction socket. statistical analysis also showed no effect of early implant exposure on the isq values figure 11: comparison of isq value between cases with gbr and cases without gbr. discussion this clinical study showed that all the implants that were placed immediately in the fresh extraction sockets and followed-up for (16 weeks) had survived (100% survival rate), and met the successful criteria of dental implant presented by misch et al.(10), with absence of failure signs and symptoms (implant mobility, pain, suppuration, and radiographic bone loss or peri-implant radiolucency). this result comes in agreement with gokcenrohlig et al.(11) the authors in their clinical and radiographic study for two years follow up detected 100% cumulative survival rate, and they concluded that placement of implant in the fresh extraction socket is a reliable treatment alternative. the results also coincided with previous studies on immediate implant placement.(12,13) this high survival rate may be attributed to careful examination, patient selection, aseptic technique, and appropriate surgical procedure with scientific management of difficulties during intraoperative work. the mean primary stability recorded in this study was (65.32 isq) which is slightly higher than values documented in the previous studies on immediate implant that recorded primary implant stability ranged from (61.2 to 62 isq). (14-16) this higher value of mean primary stability may be related to the intraoperative surgeon judgment by under-sized drilling technique or using wider implant diameter than the final drill, especially in sites of soft bone, in order to achieve adequate primary implant stability. the implant stability increased over time with a highly significant statistical difference, and the mean secondary implant stability at 16 weeks was (69.78 isq) with (53.7%) of implants achieving high secondary stability (isq value ≥70). the high value of primary implant stability also can explain the high survival rate where (70.7%) of the inserted fixtures had primary stability above 60 isq. many studies have showed that implants with isq values of more than 65 isq at the time of insertion (baseline) have a 99% survival rate, isq values of 60-65 isq have been used as a threshold values for implant success.(17,18) if the primary stability is insufficient the healing process will be affected and osseointegration will not happen, good primary implant stability mean less micromotion and reduction in the micromotion of the implants increases the chance of secondary (biological) stability and reduces the chance of fibrous encapsulation and the failure of osseointegration.(15,18) in a recent study conducted at the college of dentistry/ baghdad university by ibraheem and al-adili(19), using the same type of implants and loading protocol, where 44 implants placed in native bone had measured primary implant stability during surgery equal to (73.2 isq), and (73.5 isq) at 16 weeks. the higher isq values of j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 108 the mentioned study may be related to the difference in the timing of implant placement after extraction, these results coincide with another study comparing stability of implants placed in healed sites vs implants placed in extraction sockets, where the authors found that implants placed in a healed alveolar sites exhibited superior isq values at base line, at 90 days, and at 150 days (16). in this study (63.4%) of cases had gaps (≥ 2 mm) and bone defects required augmentation. although the autogenous bone is regarded as a gold slandered for bone augmentation, but the retrieved amount from the drilling procedure was inadequate to fill these gaps, so β-tcp represent the main bulk of augmentation material in almost all cases in this study, combined with collagen membrane that was used to cover the surgical area and hinder soft tissue migration to these defects. various combinations of bone grafting materials combined with resorbable and nonresorbable membrane, have been identified in the previous studies to solve this problem.(20,21,22) the results showed that there was no statistical significant difference between the cases with gbr and the other cases regarding the mean isq value neither at baseline nor at 16 weeks, with significant increase in the mean isq value of the cases that used gbr. these results are in keeping with aloy-prósper et al.(23) where the authors in their clinical study for three years follow-up comparing implants with and without gbr, found that there was no significant difference between the two groups in success rate and marginal bone loss. the results also complemented previous studies to confirm β-tcp application with immediate implant, harel et al.(24) found that using β-tcp resulted in preventing bone loss in 72.1% of cases, the authors concluded that there is no statistical significant difference with other implants placed in sites that do not need augmentation regarding survival rate and bone resorption. in another retrospective study by daif (25) who utilized ct scan to examine the density of bone around immediately placed implants, and he found that pure-phase multiporous β-tcp enhances bone density around immediately placed implants after 6 months of loading. the author mentioned that the pure-phase multiporous β tcp may have a positive effect on the bone density when used to fill the bone gaps around immediate dental implants. this idea may explain the significant increase of the implant stability during the healing period. results showed that (13) implants top, which represent (31.7%) of implants had been partially or completely exposed during the healing period, the implants top appeared at early postoperative visit during suture removal and continued to the second stage surgery. statistical analysis found no correlation between this minor complication with (patient’s gender, using guided bone regeneration technique, or presence of bone dehiscence in the extraction socket during implant placement). therefore, other factors related to intra and postoperative environment may have a relation to this complication. tal (26) suggested that the possible causes of early implant exposure are: flap tension, mechanical trauma, loosening of the cover screw, and interposition of bone debris. mendoza et al.(27) failed to establish a relation between early implant top exposure and some implant related factors such as timing of implant placement, tissue thickness, and using guided regeneration technique. as a prophylactic measure, the patients were instructed to maintain good oral hygiene combined with chlorhexidine mouthwash 0.12 % twice daily, which was continued along the healing period in order to utilize the action of chlorhexidine in reducing plaque accumulation and improve gingival health around implant.(28) because early exposure make an area of plaque accumulation that may lead to inflammation and damage to the peri implant tissue.(26) rosenquist and grenthe (29) suggested punch removal of the soft tissue and completely expose the partially exposed cover screw, the authors encouraged this procedure to facilitate cleaning to decrease the possibility of future peri-implantitis. statistical analysis showed that early implant exposure had no effect on the isq value, this finding coincides with a study comparing submerged with non-submerged implants, which found no statistical significant difference regarding osseointegration and bone implant contact between the two groups (30). flap dehiscence was observed in two male patients, in these two flaps guided bone regeneration (gbr) was used. to manage the problem, in one case the wound was re-sutured after debriding and refreshing the flap edges, in the other case the area was left to heal by secondary intention, with reinstruction for oral hygiene measures as some patients neglect regarding oral hygiene was detected during the early postoperative period. the areas were healed and all the implants survived without complications. kim and yun (31) found that flap dehiscence occurs mostly in male patients with statistical difference than females, and also in cases where bone graft and membrane are used, j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 109 the authors advocated oral hygiene measures rather than flap re-suturing to manage this complication. sadig and almas (32) stated that most of risk factors responsible for wound dehiscence are largely related to iatrogenic causes and partly related to patient neglect. within the limit of time of this study and the number of the available sample, immediate implant placement in a fresh extraction socket can be regarded as a predictable treatment approach, have the benefit of reducing treatment time, and the numbers of surgical procedures and can be applied even in the presence of bone defect and gaps, recording the same final results when careful preoperative examination and appropriate intraoperative protocol is utilized. references 1. schulte w, heimke g. the tubinger immediate implant. die quintessenz. 1976; 27(6):17-23. 2. lazzara rj. immediate implant placement into extraction sites: surgical and restorative advantages. int j periodontics restorative 1989; 9(5): 332. 3. gelb da. immediate implant surgery: three-year retrospective evaluation of 50 consecutive cases. int j oral maxillofac implants. 1993; 8(4): 388-99. 4. chen st, wilson jr tg, hammerle ch. immediate or early placement of implants following tooth extraction: review of biologic basis, clinical procedures, and outcomes. int j oral maxillofac implants 2004; 19(19):12-25. 5. bhola m, neely al, kolhatkar s. immediate implant placement: clinical decisions, advantages, and disadvantages. j prosthodont 2008; 17(7): 57681. 6. hämmerle ch, chen st, wilson jr tg. consensus statements and recommended clinical procedures regarding the placement of implants in extraction sockets. int j oral maxillofac implants 2004; 19(suppl): 26-8. 7. chen s, buser d. implants in post-extraction sites: a literature update. iti treatment guide. 2004; 3: 9-15. 8. zhou y, jiang t, qian m, zhang x, wang j, shi b, xia h, cheng x, wang y. roles of bone scintigraphy and resonance frequency analysis in evaluating osseointegration of endosseous implant. biomaterials 2008; 29(4): 461-74. 9. balleri p, cozzolino a, ghelli l, momicchioli g, varriale a. stability measurements of osseointegrated implants using osstell in partially edentulous jaws after 1 year of loading: a pilot study. clin implant dent relat res 2002; 4(3): 12832. 10. misch ce, perel ml, wang hl, sammartino g, galindo-moreno p, trisi p, steigmann m, rebaudi a, palti a, pikos ma, schwartz-arad d. implant success, survival, and failure: the international congress of oral implantologists (icoi) pisa consensus conference. implant dent 2008; 17(1): 515. 11. gökçen-röhlig b, meriç u, keskin h. clinical and radiographic outcomes of implants immediately placed in fresh extraction sockets. oral surg oral med oral pathol oral radiol endod 2010; 109(4): e1-7. 12. barone a, rispoli l, vozza i, quaranta a, covani u. immediate restoration of single implants placed immediately after tooth extraction. j periodontol 2006; 77(11):1914-20. 13. kan jy, rungcharassaeng k, lozada j. immediate placement and provisionalization of maxillary anterior single implants: 1-year prospective study. int j oral maxillofac implants. 2002; 18(1): 31-9. 14. becker w, sennerby l, bedrossian e, becker be, lucchini jp. implant stability measurements for implants placed at the time of extraction: a cohort, prospective clinical trial. j periodontol 2005; 76(3): 391-7. 15. granić m, jurič ib, sušić m, boras vv, katanec d, gabrić d. implant stability comparison of immediate and delayed maxillary implant placement by use of resonance frequency analysis–a clinical study. acta clinica croatica 2015; 54(1): 3-9. 16. gehrke sa, neto s, tavares u, rossetti ph, watinaga se, giro g, shibli ja. stability of implants placed in fresh sockets versus healed alveolar sites: early findings. clin oral implants res 2015; 0: 1-6. 17. sennerby l, meredith n. implant stability measurements using resonance frequency analysis: biological and biomechanical aspects and clinical implications. periodontol 2000 2008; 47(1): 51-66. 18. rowan m, lee d, pi-anfruns j, shiffler p, aghaloo t, moy pk. mechanical versus biological stability of immediate and delayed implant placement using resonance frequency analysis. j oral maxillofac surg 2015; 73(2): 253-7. 19. ibraheem ns, al-adili ss. assessment of dental implant stability during healing period and determination of the factors that affect implant stability by means of resonance frequency analysis (clinical study). j bagh coll dentistry 2015; 27(3):109-15. 20. gher me, quintero g, assad d, monaco e, richardson ac. bone grafting and guided bone regeneration for immediate dental implants in humans. j periodontol 1994; 65(9): 881-91. 21. nemcovsky ce, artzi z, moses o. rotated split palatal flap for soft tissue primary coverage over extraction sites with immediate implant placement. description of the surgical procedure and clinical results. j periodontol 1999; 70(8): 926-34. 22. ogunsalu c, ezeokoli c, archibald a, watkins j, stoian c, daisley h, legall c, lorde s, jackson k, jaggernauth d, nelson a. comparative study of osteoblastic activity of same implants (endopore) in the immediate extraction site utilizing single photon emission computerized tomography: peri-implant autogeneous bone grafting with gtr versus no peri-implant bone grafting--experimental study in pig model. west indian medical j 2011; 60(3): 3369. 23. aloy-prósper a, peñarrocha-oltra d, peñarrochadiago m, peñarrocha-diago m. dental implants with versus without peri-implant bone defects treated with guided bone regeneration. j clin exp dent 2015; 7(3): e361. 24. harel n, moses o, palti a, ormianer z. long-term results of implants immediately placed into j bagh college dentistry vol. 28(4), december 2016 immediate implant oral and maxillofacial surgery and periodontics 110 extraction sockets grafted with β-tricalcium phosphate: a retrospective study. j oral maxillofac surg 2013; 71(2):e63-8. 25. daif et. effect of a multiporous beta-tricalicum phosphate on bone density around dental implants inserted into fresh extraction sockets. j oral implantol 2013; 39(3): 339-44. 26. tal h. spontaneous early exposure of submerged implants: i. classification and clinical observations. j periodontol 1999; 70(2): 213-9. 27. mendoza g, reyes jd, guerrero me, de la rosag m, chambrone l. influence of keratinized tissue on spontaneous exposure of submerged implants: classification and clinical observations. j osseointegr 2014;6(3): 47-50. 28. ciancio sg, lauciello f, shibly o, vitello m, mather m. the effect of an antiseptic mouthrinse on implant maintenance: plaque and peri-implant gingival tissues. j periodontol 1995; 66(11): 962-5. 29. rosenquist b, grenthe b. immediate placement of implants into extraction sockets: implant survival. int j oral maxillofac implants 1996; 11(2): 205-9. 30. weber hp, buser d, donath k, fiorellini jp, doppalapudi v, paquette dw, williams rc. comparison of healed tissues adjacent to submerged and non‐submerged unloaded titanium dental implants. a histometric study in beagle dogs. clin oral implants res 1996; 7(1):11-9. 31. kim yk, yun py. risk factors for wound dehiscence after guided bone regeneration in dental implant surgery. maxillofac plast reconstr surg 2014; 36(3):116-23. 32. sadig w, almas k. risk factors and management of dehiscent wounds in implant dentistry. implant dent. 2004; 13(2):140-7. j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 153 photographic analysis of macroaand micro-aesthetic appearance in a sample of iraqi adults with class i normal occlusion dana r. mohammed, b.d.s.)a) iman al-sheakli, b.d.s., m.sc. (b) abstract background: generally, the facial esthetics depends on the esthetic appearance of the maxillary anterior teeth. the purposes of this study were to analyse the macro-aesthetic appearance of the face and the micro-aesthetic appearance of the maxillary anterior teeth to establish the normative values for class i normal occlusion and to detect possible gender differences. materials and methods: the sample consisted of 120 iraqi adults (60 males and 60 females) aged (18-23) years. each individual was clinically examined, then with cephalostat based head position, extraoral and intraoral photographs were taken for each subject. the facial and dental measurements were measured using autocad program 2014. descriptive statistics was obtained for the measured variables for both genders and independent samples t-test was performed to evaluate the genders difference. results and conclusions: the results showed that there is a highly significant gender difference in most of the measured variables regarding the macro-aesthetic appearance, since the males have a larger facial dimensions than females, while for the micro-aesthetic appearance, there is a non-significant gender difference in most of the measured variables, that means the proportions of maxillary anterior teeth does not affected by gender difference. key words: class i normal occlusion; macro-aesthetic appearance; micro-aesthetic appearance; photographic records.(j bagh coll dentistry 2017; 29(1):153-159) introduction beauty can be defined as a combination of qualities that gives pleasure to the senses or to the mind. it is a philosophical concept and the aspects of which were studied under the term aesthetics obtained from the greek word for perception (aisthesis) and was coined by the 18th century philosopher alexander baumgarten who established esthetics as a separate field of philosophy, therefore; esthetics is the study of beauty and to a lesser extent, it’s opposite to the term ugly. it involves both the understanding and the evaluation of beauty, proportions and the symmetry (1). facial beauty is a mystery, a complex concept for which there is no equation, or numbers can successfully describe it (2, 3), whereas the dental esthetics is a complicated branch and may be regarded to be purely subjective; this ‘subjective’ branch of dentistry encompassed by rules and values that allow us to study it objectively (4). the egyptians and the greeks in the period 365 bc300 bc started to understand the divine or golden proportion that known as a golden ratio which is the ratio of 1:1.618 that considered to be the most esthetically pleasing to the human eye (5). enhancement of esthetic appearance is one of the primary consideration for the patients that seeking orthodontic treatment. (1) msc student, department of orthodontics, college of dentistry, university of baghdad. (2) assisstant professor, department of orthodontics, college of dentistry, university of baghdad. the term “appearance” is used in conjunction with the term “esthetics” because it involves a broader assessment of the patient’s face other than the teeth, so to achieve this goal, it is essential to make a comprehensive study of several facial and teeth factors to create a pleasing harmony of face and teeth (6, 7). two-dimensional photogrametry has been used in orthodontics to evaluate the facial proportions and assess changes during orthodontic treatment, this method was shown to be sufficiently non-invasive, inexpensive and reproducible since it was simple to achieve in a conventional setting, without the need for a special equipment (8, 9). the macro-aesthetics and micro-aesthetics are important divisions of esthetic appearance in orthodontics, this study aimed to analyse the macro-aesthetic appearance and micro-aesthetic appearance of maxillary anterior teeth to establish the normative values for class i normal occlusion in iraqi adults with the aid of photographs and computer analysis and to detect the possible gender differences in macro and micro-aesthetic appearance. materials and methods sample the sample selected from undergraduate studentts at college of dentistry-university of baghdad. out of 450 students examined, only 120 of them (60 females and 60 males) fitted the criteria of subject selection, which are: 1) all are j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 154 iraqies with age ranged 18-23 years, 2) having full permanent dentition regardless the third molars, 3) having normal overjet and overbite (2-4 mm), 4) bilateral class i buccal segments "molar and canine" (10), 5) skeletal class i relationship determined clinically (11) and 6) no spacing or crowding in anterior teeth. whereas those with 1) history of facial trauma, 2) orthodontic/ orthognathic treatment, dento-facial deformities, surgeries, asymmetry or bad oral habits like thumb sucking and tongue thrust, 3) anterior or posterior crossbite, 4) active periodontal diseases and gingivitis, 5) extruded or rotated teeth in the anterior region, 6) signs of attrition and restoration of the maxillary anterior teeth, or proximal caries, 7) developmental anomalies such as supernumerary teeth, 8) prosthesis in the anterior teeth were excluded from the study. methods history each subject was seated on the dental chair and information about his/her name, age, medical and dental history was obtained. after that, a written consent form was obtained from the participants to assure their voluntary participation in the study. then, each individual subjected to clinical examination which included examination of skeletal and dental relation. standardization of the photographs the camera (canon d60, japan) fixed in position and adjusted in height to be at the level of the individual’s eyes with a height adjustable tripod that controls the stability and the correct height of the camera according to the subject’s body height. the distance from the camera to the subject was fixed at a distance of about 101 cm measured from the camera lens to the ear rods, that were fit in the external auditory meatus in order to avoid the forward, backward, and tilting of the subject head (cephalostat based head position) (12), and 56 cm from the camera lens to the ear rods for frontal intraoral photographs (13). the ef-s 18-200mm f/3.5-5.6 is lens was used. subjects were seated in front of a blue background, a ruler was placed on the plastic side of cephalostat near the subject head to correct the magnification. photographic exposure the digital camera was set on the manual exposure shooting and from the wheel dial the camera was set on: iso 2000, shutter speed of 80, aperture value set on f/5.6 and flash on. two photographs were taken for each participant, for the facial photographs, each participant was positioned in the cephalostat with the interpupillary plane parallel to the floor (14), instructed to keep their teeth in maximum intercuspation and gently closed lips (15). the camera lens positioned parallel to the individual’s face and the subject was asked to look at the center of the camera’s lens during taking the photograph. the participant’s hair did not cover any part of the face (16). for the intraoral photograph, the cheek retractor was used to clearly display the maxillary anterior teeth, with the camera lens parallel to the labial surface of the teeth (17). photographic analysis each frontal facial and intra-oral photograph were analyzed by autocad 2014 program. the analysis includes: 1-the macro-aesthetic appearance that includes: a. facial landmarks: according to milutinovic et al. (18)  glabella (gl): it is the most prominent point on the midline of the face, between the eyebrows.  nasion (n): it is the point in the midline of both the nasal root and the nasofrontal suture.  inner canthus of the eye (ic): it is the medial angle of the palpebral fissure.  pupil of the eye (p): it is the hole that located in the center of the iris of the eye.  zygoin (zy): most lateral point on zygomatic arch.  alare of the nose (al): point located at each lateral rim of the ala of the nose at its widest width.  subnasale (sn): the point at which the nasal columella merges with upper mucocutaneous lip in the mid sagittal plane  chilion (ch): a point located at angle of the mouth.  stomion (sto): the midpoint of the intralabial fissure.  the labrale superius (ls): the midline point at the border of the upper lip.  the labrale inferius (li): the midline point at the border of the lower lip.  menton (me): a most inferior point located at the soft tissue chin. b. the linear facial measurements: according to proffit et al. (19):  zygomatic width (zy-zy): the distance between the two zygion points.  inter-canthal distance (icd): the distance between the median angles of the palpebral fissure.  interpupillary width (ipw): it is a horizontal line between the center of right and left pupils. j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 155  interalar width (iaw): the distance between the two alare points of the nose.  mouth width (mw): the distance between the two angles of the mouth. c. vertical facial measurements: according to proffit et al. (19):  facial height (n-me): the distance between soft tissue nasion and menton.  lower face height (sn-me): the distance between subnasale and menton.  upper lip vermilion (ulv): the distance between labrale superius and stomion.  lower lip vermilion (llv): the distance between labrale inferius and stomion. 2-the micro-aesthetic appearance includes: a. the golden proportion: it could be defined as the proportion of successive width of the maxillary anterior teeth. it should remain constant, when progressing distally from the midline (20). the mesiodistal width measured parallel to the incisal edge, and at the widest mesiodistal portion of the tooth of each lateral incisor and the canine, as shown in figure 1. it was calculated as follow: -for lateral incisor=mdw of lateral incisor x 100 mdw of central incisor -for canine=mdw of canine x 100 mdw of lateral incisor b.the golden percentage: the proportional width of each maxillary anterior tooth (for the right and left side) should be: 10% for the canine, 15% for the lateral incisor, 25% for the central incisor of the total distance across the maxillary anterior segment (21), it was calculated as follow: -golden percentage= mdw central, lateral, canine x 100 cmdw of all maxillary anterior teeth *the mesiodistal dimension measured parallel to the incisal edge, and at the widest mesiodistal portion of the tooth of each central incisor, lateral incisor and the canine,as shown in figure 1. figure 1: measurement of mesiodistal width of maxillary anterior teeth. b.tooth proportionality-height and width ratio: the ideal maxillary central incisor width should be approximately 80% compared to it’s height (22). it was calculated as follow: -width-height ratio= width of the tooth x100 height of the tooth * the incisogingival dimensions of the maxillary central incisor were measured at the longest apical-coronal portion of the tooth, as shown in figure 2 c.height of contact points: contact between the anterior teeth is where the teeth actually touch (23). the golden ratio was applied to the height of the contact points of the anterior teeth. this ratio was calculated as follow: -for central incisor= height of contact point between centrals x100 height of central incisor -for lateral incisor= height of contact point (central-lateral) x100 height of central incisor -for canine= height of contact point (lateral-canine) x100 height of central incisor *the height of contact point was measured from the incisal convergence of the gingival embrasure to the gingival convergence of the incisal embrasure (24) as shown in figure 2 d.total maxillary anterior teeth width: the distance between the tips of the maxillary canines in a horizontal straight line was measured (25). (figure 2) figure 2: measurement of height of maxillary central incisors,height of contact points and total anterior teeth width. results and discussion the sample in this study was selected at age between (18-23) years because the individuals maintain the same facial pattern till 25 years (26), and to minimize the effect of any remaining skeletal growth since the majority of facial growth is usually completed by the age of 16-17 years (27), as well as the occlusion at this age has been established regardless of the third molars and the possibility of teeth being mutilated by caries or wasting diseases would be minimal (28). j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 156 the results in table 1 showed that the mean values for facial parameters (macro-aesthetic appearance) were higher in males than females, this finding could be attributed to that the human being faces have dimorphic features between the sexes, especially after puberty (29), and because males have longer growth period than females, the males were having greater measurements than females (30), one exception is for the upper and lower lip vermillion, which were higher in females than males, this finding may be attributed to the suggestion that made by peck and peck (2) in that the esthetically attractive white female face demonstrated a larger lips, and found to be in agreement with ahmed et al. (31) and disagree with ellakwa et al. (32). independent sample t-test indicated that there is a high significant difference regarding the measured facial variables except in the inter-canthal distance (icd), zygomatic width (zy-zy), upper lip vermilion (ulv), and lower lip vermilion (llv) where there is a nonsignificant gender difference, this comes in line with asghari et al. (15) and disagree with ellakwa et al. (32). regarding the maxillary anterior teeth measurements, table 2 showed that the mean values of the measured variables were higher in males than in females except in the mesiodistal width of left (mdw l2) and right lateral incisor (mdw r2), height of the contact point between “central incisors (ci-ci), lateral incisor and canine (left and right li-ca)”, whereas the mean values of mesiodistal width of left canine (mdw 3l) were equal in both genders, this finding comes in line with murthy and ramani (33) and disagree with gillen et al. (34) since the sexual dimorphism has been reported for the maxillary tooth dimension in most racial groups (21). additionally, the independent sample t-test showed that there is a non-significant difference regarding the maxillary anterior teeth variables except in the inter-canine distance (icad), height of left central incisor and mesiodistal width of both central incisors where there is a high significant difference, this could be attributed to sex-linked inheritance, so that the sex-hormonal influences were suggested (35), since the sexual dimorphism has a genetic basis according to garn et al. (36), but till now this hypothesis is not proved. table 3 showed that there is a non-significant gender difference in micro-aesthetic appearance which is in agreement with fayyad et al. (37) and ahmed et al. (38) and in disagreement with parnia et al. (39), beside that the mean values of the measured variables were higher in females than males, this may be due to that the gender is not considered a significant factor (37), since the proportions regarding the micro-aesthetic appearance were depending on the ethnic or racial characteristics rather than gender difference (39). in this study the sexual diamorphism was significant in macro-aesthetic appearance with males having larger facial measurements, on the other hand the gender had a non-significant effect on the maxillary anterior teeth proportions. table 1: descriptive statistics and gender differences in macro-aesthetic appearance in both genders variables descriptive statistics gender difference (d.f.= 118) males (n=60) females (n=60) mean s.d. mean s.d. mean difference t-test p-value icd 31.62 3.17 30.89 3.37 0.73 1.230 0.221 (ns) ipw 63.41 4.69 60.96 4.59 2.45 2.888 0.005 (hs) zy-zy 127.77 7.68 125.73 9.05 2.04 1.334 0.185 (ns) iaw 39.68 3.07 35.51 3.26 4.18 7.225 0.000 (hs) mw 52.54 3.78 49.58 4.56 2.96 3.872 0.000 (hs) n-me 125.60 9.02 115.47 7.95 10.13 6.524 0.000 (hs) sn-me 69.92 5.23 60.63 5.43 9.29 9.537 0.000 (hs) ulv 5.33 1.29 5.38 1.02 -0.05 -0.216 0.829 (ns) llv 10.11 1.76 10.29 1.48 -0.18 -0.617 0.538 (ns) j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 157 table 2: descriptive statistics and gender differences in maxillary anterior teeth variables variables descriptive statistics gender difference (d.f.=118) males (n=60) females (n=60) mean s.d. mean s.d. mean difference t-test p-value mdw 1 l 8.80 0.60 8.63 0.49 0.17 1.703 0.091 (ns) mdw 1 r 10.37 0.96 10.26 1.06 0.11 0.596 0.552 (ns) h 1l 8.79 0.51 8.58 0.54 0.21 2.200 0.030 (s) h 1r 10.39 0.94 10.15 1.05 0.24 1.328 0.187 (ns) mdw 2l 5.84 0.53 5.90 0.64 -0.06 -0.554 0.581 (ns) mdw 2r 5.84 0.59 5.93 0.50 -0.09 -0.860 0.392 (ns) mdw 3l 4.79 0.61 4.79 0.57 0.00 -0.028 0.977 (ns) mdw 3r 4.70 0.61 4.59 0.54 0.11 1.032 0.304 (ns) mdw 1 17.59 1.08 17.21 1 0.38 2.009 0.047 (s) height of the contact point ci-ci 3.97 0.83 3.98 0.83 -0.01 -0.060 0.952 (ns) height of the contact point left ci-li 3.34 1.00 3.28 0.94 0.06 0.363 0.717 (ns) height of the contact point right ci-li 3.54 0.94 3.48 0.84 0.06 0.391 0.697 (ns) height of the contact point left li-ca 2.92 0.86 3.00 0.88 -0.08 -0.529 0.598 (ns) height of the contact point right li-ca 3.15 0.89 3.17 0.84 -0.02 -0.141 0.888 (ns) iid 29.27 1.55 29.04 1.57 0.24 0.826 0.410 (ns) icad 34.51 1.88 33.60 1.84 0.90 2.660 0.009 (hs) table 3: descriptive statistics and gender differences in micro-aesthetic appearance variables descriptive statistics gender difference (d.f.=118) males (n=60) females (n=60) mean s.d. mean s.d. mean difference t-test p-value golden proportion: left li to ci 66.71 7.68 68.53 7.83 -1.82 -1.287 0.201(ns) golden proportion: right li to ci 66.55 6.68 69.29 6.46 -2.74 -2.284 0.024 (s) golden proportion: left ca to li 82.55 12.25 81.91 11.42 0.64 0.297 0.767(ns) golden proportion:right ca to li 80.95 11.45 77.96 11.27 2.99 1.441 0.152(ns) width-height ratio of left ci 85.41 7.72 84.91 8.90 0.50 0.328 0.743(ns) width-height ratio of right ci 85.07 7.16 85.21 8.70 -0.14 -0.099 0.921(ns) cmdw 38.76 2.07 38.42 1.97 0.34 0.926 0.356(ns) golden percentage: left ci to cmdw 22.72 1.23 22.48 1.02 0.24 1.150 0.252(ns) golden percentage: right ci to cmdw 22.69 1.02 22.33 1.02 0.36 1.927 0.056(ns) golden percentage: left li to cmdw 15.09 1.23 15.35 1.30 -0.26 -1.141 0.256(ns) golden percentage: right li to cmdw 15.05 1.18 15.43 1.10 -0.37 -1.794 0.075(ns) golden percentage: left ca to cmdw 12.35 1.33 12.47 1.24 -0.12 -0.521 0.603(ns) golden percentage: right ca to cmdw 12.10 1.34 11.94 1.24 0.17 0.707 0.481(ns) height of contact point %: ci-ci (left) 38.27 6.95 38.80 6.95 -0.52 -0.412 0.681(ns) height of contact point %: ci-ci (right) 38.18 6.90 39.19 6.95 -1.01 -0.800 0.425(ns) height of contact point % : ci-li (left) 32.03 8.54 32.03 8.73 0 0 1 (ns) height of contact point % : ci-li (right) 33.93 7.80 34.38 7.85 -0.45 -0.315 0.754(ns) height of contact point % : li-ca (left) 27.96 7.41 29.26 8.20 -1.30 -0.912 0.364(ns) height of contact point % : li-ca (right) 30.13 7.49 31.19 7.19 -1.05 -0.785 0.434(ns) references 1naini fb, moss jp, gill ds. the enigma of facial beauty: esthetics, proportions, deformity and controversy. am j orthod dentofac orthop 2006; 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(7)5: 62-70. 38ahmed n, abbas m, maqsood a. evaluation of recurring esthetic dental proportion in natural smile of pakistani sample. pakistan oral & dental journal 2014; 34(4): 739-42. 39parnia f, hafezeqoran a, mahboub f, moslehifard e, koodaryan r, moteyagheni r, saber f. proportions of maxillary anterior teeth relative to each other and to golden standard in tabriz dental faculty students. j dent clin dent 2010; 4(3): 83-6. الخالصة مالي الجزئيوالمظهر الج للوجه الكلي الجمالي المظهر إلى تحليل الدراسة تهدف هذه هدفت. العلوية األمامية لألسنان الجمالي المظهر على يعتمد الوجه جمال بصورة عامة، الخلفية: .الجنسين بين عن االختالفات المحتملة للفئة األولى ذات االطباق الطبيعي والكشف المعيارية القيم لتأسيس العلوية األمامية لألسنان تثبيت ثم تمسريريا, فرد كل فحص سنة وأجري( 23-01) بين أعمارهم تتراوح الذين( إناث 01 و ذكور 01)العراقيين من البالغين 021من الدراسة عينة تكونت العينة والطرق: تم بمرجل ثالثي القوائم قابل للتعديل. هاعموق في المثبتة الرقمية الكاميرا الفم باستخدام ولداخل للوجه أمامية لكل فرد رقمية صورة و أخذت ، cephalostatجهاز ال بأستخدام الرأس تم استخدام . (autocad 2102 برنامج) االلكتروني بالحاسب التصميم و الرسم نظام باستخدام األسنان قياسات الى أضافة جهللو عمودية وأربع مسافات خطية مسافات خمس قياس .بين الجنسين الفرق لتقييمt-test) ت المستقل ) اختبار و أجري الجنسين لكال المتغيرات لقياس الوصفي اإلحصاء j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 159 أبعاد يتميزون بأن الذكور علما أن الكلي، الجمالي المظهر بشأن المقاسة المتغيرات معظم في الجنسين معنويا بين فرقا أن هناك صائيةالنتائج االح أظهرت النتائج و االستنتاجات: وهذا الجزئي، الجمالي للمظهر المقاسة بالنسبة المتغيرات معظم في الجنسين بين غير معنويا االحصائية أظهرت أن هناك فرقا أن النتائج حين في اإلناث، من والوجه أكبر الجمجمة الجنسين بين بالفرق تتأثر ال العلوية األمامية المتعلقة باألسنان النسب أن يعني j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 160 j bagh college dentistry vol. 28(4), december 2016 time of emergence pedodontics, orthodontics and preventive dentistry 161 zaydoon final.doc j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 103 immunohistochemical expression of icam-1 and cortactin as cell adhesive molecule and invasive markers in hodgkin’s and non-hodgkin’s lymphoma of the head and neck region (a comparative study) zaydoon mahmood kasim, b.d.s., m.sc. (1) wasan h. younis, b.d.s., m.sc., ph.d. (2) abstarct background: lymphomas are a group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and cause the characteristic clinical features of lymphadenopathy. intercellular adhesion molecule-1 (icam1) (cd54) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily of adhesion molecules. cortactin was first identified as one of the major substrates for src kinase. because it localized to cortical actin structures, the aims of this study was to evaluate and compare the immunohistochemical of icam-1 expression as cell adhesion molecule marker and cortactin expression as invasive marker. material and methods: this study was performed on (68) formalin-fixed, paraffin-embedded blocks, histopathologically diagnosed as lymphoma (head and neck lesions).immunohistochemical staining of icam-1and cortactin was performed on each case of the study sample. results: the expression of icam-1 was membranous and cytoplasmic, the study cases showed a 98.5% positive reaction to icam-1, score 2 was the most common and found in 69.1% of all cases.the expression of cortactin was cytoplasmic, 98.5% of cases expressed positive reactions to cortactin, score 1 was the most common and found in 42.7% of all cases. conclusion: although the two markers showed a higher expression rate in all lymphomas (both hl and nhl) in this study, they can't be used to differentiate between them, nor can be used to differentiate between the subtypes of both hl and nhl. the high icam-1positive expression clarified that in addition to its role in cell-cell and cell-stromal interactions, it participates in proliferation, differentiation and invasion of malignant lymphoma cells.the present study is the first one that used cortactin as an invasive marker for lymphoma. keywords: lymphoma, hodgkin's lymphoma (hl), non-hodgkin's lymphoma (nhl), icam-1 (cd54), cortactin. (j bagh coll dentistry 2014; 26(2): 103-110). introduction lymphomas are a group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and cause the characteristic clinical features of lymphadenopathy. occasionally, they may spill over into blood "leukaemic phase" or infiltrate organs outside the lymphoid tissue.(1) most lymphomas encountered in routine practice belong to the b-cell origin, and the others to t-cell origin. lymphomas are subdivided into hodgkin lymphomas (hl) and non-hodgkin lymphomas (nhl), with the latter being more common.(2) the cell adhesive molecules are of importance in the establishment of normal tissue structure and function. they participate in a variety of physiological processes such as morphogenesis, embryogenesis, organogenesis, cellular proliferation, immunological function, wound healing, tissue repair, cell migration, differentiation, apoptosis, and inflammation.(3-5) it is well known that many cell adhesion molecules function as tumor suppressors. these (1)ph.d. student, department of oral diagnosis, college of dentistry, university of baghdad (2)professor, department of oral diagnosis, college of dentistry, university of baghdad molecules exert their tumor suppressive effect mainly through cell-adhesion-mediated contact inhibition. a number of cell adhesion moleculetumor suppressors have been reported to be capable of reducing cell migration.(5) intercellular adhesion molecule-1 (icam-1) (cd54) is a transmembrane glycoprotein belonging to the immunoglobulin superfamily of adhesion molecules. icam-1 participates as an adhesion molecule as well as a co-stimulatory molecule to improve both antigen recognition by the t-cell receptor complex and subsequent t-cell activation. icam-1 is also involved in lymphoid trafficking and extravasation through lymphocyte/endothelial interactions. in normal b cells it mediates homotypic adhesions. icam-1 is expressed on the surface of many cancer cell types and is also present in a soluble form circulating in the plasma of cancer patients at elevated levels. it has also been proposed that icam-1 may be involved in the process of cancer metastases, facilitating the spread of metastatic cancer cells to secondary sites. in b-cell lymphoproliferative disorders the tumor expression of icam-1 is closely related to the degree of cell maturation. thus, mantle-cellderived lymphoproliferative diseases, such as j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 104 chronic lymphocytic leukemia (cll) or mantlecell lymphoma, are often negative or weakly positive for icam-1, whereas icam-1 expression is more heterogeneous in germinal center cell lymphomas such as follicular or diffuse large-cell subtypes. it has been suggested that reduction of this molecule on the neoplastic lymphoid cells could impair the t-cell recognition with this contributing to neoplastic dissemination through a defective antitumor response.(6,7) the structural organization and function of normal tissues is to a great extent determined by interactions between cells and the extra cellular matrix (ecm). tissues are organized into compartments separated from each other by two types of ecm: basement membrane and interstitial connective tissue, each of these components of ecm is made up of collagens, glycoproteins, and proteoglycans. when invasion happens tumor cells must interact with the ecm at several stages.(8) cancer invasion and metastasis are landmark events that transform a locally growing tumor into a systemic, metastatic, and life-threatening disease and they are the major cause of cancer-related morbidity and mortality. the initial steps of local invasion include the activation of signaling pathways that control cytoskeletal dynamics in tumor cells and the turnover of cell matrix and cell-cell junctions, followed by active tumor cell migration into the adjacent tissue.(8,9) cortactin was first identified as one of the major substrates for src kinase. because it localized to cortical actin structures, it was named cortactin. the strong localization of cortactin to cell motility structures such as lamellipodia and invadopodia, sparked an early interest in the role of cortactin in cell invasion and migration. indeed, overexpression of cortactin has been shown to enhance cell motility in a variety of assays, including transwell migration, wound closure, and single cell motility. cortactin appears to play a central role in cell movement through tissues which frequently requires the degradation of ecm. invadopodia were first identified in src kinase transformed cells and are thought to constitute the invasive cellular machinery. they are characterized by the colocalization of many proteins that are found in focal adhesions and lamellipodia, as well as membrane trafficking proteins and proteases. related structures, podosomes, are found in osteoclasts, macrophages and other normal cells that must cross tissue barriers or remodel ecm. these downstream targets presumably function to coordinate the activities of the actin cytoskeleton, focal adhesions, protease activity, and membrane dynamics to the site of invadopodia formation. (1012) the aims of this study was to evaluate and compare the immunohistochemical of icam-1 expression as cell adhesion molecule marker and cortactin expression as invasive marker and to correlate the expression of icam-1and cortactin in hodgkin’s and non-hodgkin’s lymphoma. materials and methods this study was performed on (68) formalinfixed, paraffin-embedded blocks, histopathologically diagnosed as lymphoma (head and neck lesions).the diagnosis of each case was confirmed by the histological examination of the hematoxylin and eosinstained sections by two experienced pathologists. histological classification was determined according to the world health organization (who) for hl (25 cases) classification and the international formulation criteria for nhl (43 cases) classification. the diagnosis of hl was confirmed by using immunohistochemical staining with cd15 and cd30, and the diagnosis of nhl was confirmed by using immunohistochemical staining with cd3, cd20 and bcl2. each case was stained by icam-1(antiicam1 antibody [mem-111] ab2213,abcom, england) and cortactin (anti-cortactin antibody [ep1922y], abcom, england), for each antibody the following procedure is done, starting by deparaffinization of a 4µm thickness section of each block mounted on positively charged microscopic slides at 65 ºc overnight, followed by dehydration, then application of hydrogen peroxidase block. antigen retrieving was perform for icam-1 only ( not for cortactin) by applying the slides in hot citrate buffer solution ph 6.0 (9599 ºc) for 10 minute, followed by protein block, then the application of primary antibody and incubation (6hr for both icam-1 and cortactin), then the rabbit anti-mouse antibody unconjugated application, followed by goat anti-rabbit hrp conjugate application, and finally the application of dab plus chromogen then hematoxylin counterstain. the expression for all markers was evaluated semi-quantitatively. it was obtained by counting the number of tumor cells in 5 fields (using 40x objective in most represented areas of sections) and calculates the percentage of tumor cells that labeled a brown cytoplasmic. labeling index for each field was calculated using the following equation: (number of positive cells/ number of total cells); the mean value of labeling indices for the five fields was considered to be the label index for the case. j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 105 the scoring categories for each antibody; 1-icam-1; the tumor cells labeled by antibody display a brown cytoplasmic and membrane staining pattern, immunoreactivity was classified as:(1) <10%, (2) 10%-50% and (3) >50%. (13) 2-cortactin; the tumor cells labelled by antibody display a brown cytoplasmic staining pattern, immunoreactivity was classified: (1) < 25%, (2) 25%-50%, (3) > 50%. (14) computerized statistical program (statistical package for social sciences, spss version 15) was used for the statistical analysis of data. results the expression of icam-1 was membranous and cytoplasmic. a 67 cases were positive (98.5%), and one case was negative (1.5%), the positivity for hl was 100% and for nhl was 97.7%."score 2" represent 64% and 72.1% of both hl and nhl respectively. no statistically significant difference was found between the two types of lymphoma in icam-1 expression, the details of icam-1 scoring categories is shown table 1 the expression of icam-1 in hodgkin's lymphoma cases according to its subtypes is shows that the commonest category was “score 2” (64%) followed by "score 3" (36%), as seen in table 2. however, no statistical significant difference was found in the expression of icam1 between the subtypes of hl. figure 1 shows the expression of icam-1 in hl case. the expression of icam-1 in non-hodgkin lymphoma cases found that the most common expression was “score 2” in 31 cases (72.1%), followed by "score 3"(table 3). as in hl, regarding the scoring of icam-1 there was no significant different between the nhl subtype. fig 2 and 3 shows the expression of icam-1 in nhl case cortactin expression was cytoplasmic; there were 67 positive cases (98.5%) and only one case negative (1.5%), the numbers of lymphoma cases according to scoring categories for cortactin are shown in the following table, no statistically significant correlation was found between the types of lymphoma related to the scoring category for cortactin, as seen in table 4. all cases of hl were positive for cortactin, "score 2" and "score 3" where the most common scores and represent 36% for both of all hl cases, followed by "score 1" (28%). the cytoplasmic expression of cortactin in hl is shown in fig 4 and 5. no correlation was found between the subtype of hl in relation to the score categories of cortactin as showed in table 5. the percentage of positive expression of cortactin in nhl cases was 97.7%, the highest expression was found in "score 1” with 22 cases (51.2%), followed by "score 2" which was 32.6%. the cytoplasmic expression of cortactin in nhl is seen in fig 6. as in hl, there was no significant correlation found between the subtypes of nhl regarding the score of cortactin. details of cortactin expression according to the subtypes of nhl found in table 6. the correlation between percentages of expression of the icam-1 and cortactin in hl and nhl cases was analyzed using spearman's rank correlation coefficient (spearman's rho).the results of cd54 expression in hl cases showed that the cd54 expression correlated significantly with that of cortactinat level p= 0.05. in nhl cases also the cd54 expression correlated significantly with that of cortactinbut at level p= 0.01. discussion hayes & seigel (7) studied the level of expression of icam-1 in different tissue and tumor types and found that tumors of the lymphatic system had the highest average icam1 scores. this is in agreement with the results of the present study were the percentage of icam-1 was 98.5% of all cases of study sample. the higher levels of icam-1 seen in lymphoid tumors is most likely due to the fact that icam-1 is normally found in lymphoid tissues and would seem to be a favorable environment for icam-1 expression. similarly, ruco et al (15) stated that, expressed icam-1 is a characteristic feature of h/rs cells in lymph node from patients with hl, also vihinenet al 16 found that icam-1 was strongly expressed in involved tissues of hl. uchihara et al 17 examined the expression of icam-1 in 4 hl cell lines and found that icam-1 was seen in all hl cell lines. this is in agreement with the result of the present study were the expression of icam-1 was found in all cases of hl, with no significant difference among the subtypes. this could be related to the fact that in hl the origin of the malignant cells (hodgkin and reed-sternberg cells) are of b-cell origin and these malignant cells constitute only a small fraction of all cells present in the nodes, the majority of which represent inflammatory cells, including lymphocytes, plasma cells, eosinophils and histiocytes. it has been demonstrated that interactions between neoplastic and surrounding reactive cells, mediated by adhesive molecules which play an important role in the pathogenesis of hl.(18) j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 106 fig. 1: the expression of icam-1 in a hl case (mixed cellularity subtype) (×100) fig. 2: the expression of icam-1 in nhl case (low grade), (×100) fig. 3: the expression of icam-1 in nhl case (high grade), (×100) fig. 4: the expression of cortactin in hl case (nodular sclerosing). (×100) fig. 5: the expression of cortactin in hl case (mixed cellularity). (×40) fig 6: the expression of cortactin in nhl case (intermediate grade). (×100) j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 107 table 1: the numbers of lymphoma cases according to scoring categories for icam-1 total icam-1 lymphoma types score 3 score 2 score 1 negative 25 9 16 0 0 no. hl 36.8% 13.3% 23.5% 0% 0% % total 100% 36% 64% 0% 0% %hl 43 11 31 0 1 no. nhl 63.3% 16.2% 45.6% 0% 1.5% % total 100% 25.6% 72.1% 0% 2.3% %nhl 68 20 47 0 1 no. total 100% 29.4% 69.1% 0% 1.5% % chi-squared value 0.72, df 1, significance level p (2 sided) = 0.3961 table 2: expression of icam-1 in hl cases of the study sample total icam-1 subtypes of hl score 3 score 2 score 1 1 0 1 0 no. lymphocyte rich 4% 0% 4% 0% % total 0% 0% 100% 0% %subtype 7 3 4 0 no. mixed cellularity 28% 12% 16% 0% %total 100% 42.9% 57.1% 0% %subtype 17 6 11 0 no. nodular sclerosing 68% 24% 44% 0% %total 100% 35.3% 64.7% 0% %subtype 25 9 16 0 no. total 100% 36% 64% 0% % chi-squared value 0.709, df 2, significance level p (2 sided) = 0.7015 table 3: expression of icam-1 in nhl cases of the study sample total icam-1 subtypes of nhl score 3 score 2 score 1 negative 6 2 3 0 1 no. low grade 14% 4.7% 10% 0% 2.3% %total 100% 33.3% 50% 0% 16.7% %subtype 16 4 12 0 0 no. intermediate grade 37.2% 9.3% 27.9% 0% 0% %total 100% 25% 75% 0% 0% %subtype 21 5 16 0 0 no. high grade 48.8% 11.6% 37.2% 0% 0% %total 100% 23.8% 76.2% 0% 0% %subtype 43 11 31 0 1 no. total 100% 25.6% 72.1% 0% 2.3% % chi-squared value 0.567, df 2, significance level p (2 sided) = 0.7531 table 4: expression of cortactin in lymphoma study cases total cortactin lymphoma types score 3 score 2 score 1 negative 25 9 9 7 0 no. hl 36.8% 13.2% 13.2% 10.4% 0% %total 100% 36% 36% 28% 0% %hl 43 6 14 22 1 no. nhl 63.2% 8.9% 20.6% 32.3% 1.5% %total 100% 13.9% 32.6 51.2% 2.3% %nhl 68 15 23 29 1 no. total 100% 22.1% 33.7% 42.7% 1.5% % j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 108 chi-squared value 5.485, df 2, significance level p (2 sided) = 0.0644. table 5: the expression of cortactin in hl study cases total cortactin subtypes of hl score 3 score 2 score 1 negative 1 0 0 1 0 no. lymphocytic rich 4% 0% 0% 4% 0% %total 100% 0% 0% 100% 0% %subtype 7 3 3 1 0 no. mixed cellularity 28% 0% 12% 4% 0% %total 100% 42.8% 42.8% 14.4% 0% %subtype 17 6 6 5 0 no. nodular sclerosing 68% 0% 24% 20% 0% %total 100% 35.3% 35.3% 29.4% 0% %subtype 25 9 9 7 0 no. total 100% 36% 36% 28% 0% % chi-squared value 3.241, df 4, significance level p (2 sided) =0.518 table 6: the expression of cortactin in nhl study cases total cortactin subtypes of nhl score 3 score 2 score 1 negative 6 2 3 1 0 no. low grade 14% 4.7% 7% 2.3% 0% %total 100% 33.4% 50% 16.6% 0% %subtype 16 4 3 8 1 no. intermediate grade 37.2% 9.3% 7% 18.6% 2.3% %total 100% 25% 43.7% 50% 6.3% %subtype 21 0 8 13 0 no. high grade 48.8% 0% 18.6% 30.2% 0% %total 100% 0% 38.1% 61.9% 0% %subtype 43 6 14 22 1 no. total 100% 13.9% 32.6% 51.2% 2.3% % chi-squared value 9.403, df 4, significance level p (2 sided) = 0.0517 the level of icam-1 expression in nhl in the present study was 97.7% which is slightly lower than that of hl, the expression in intermediate and high grades was nonsignificantly higher than that of low grade and this in agreement with maio et al (19), who stated that, in in b-cell nhl, icam-1 expression appears to correlate with the differentiation stage of malignant cells, "high-grade" and "intermediate grade" b-cell nhl express in general a higher level of icam-1 than "low-grade", icam-1 was not detected on malignant t cells. jacob et al (20) stated that, b-lymphocytes in high grade nhl express higher levels of cellular adhesion molecules than low grade subtypes which are similar to the findings of this study. terol et al (21) in their study on nhl found that 80% of cases where positive to icam-1 and no significant relationship was found in icam-1 expression and the lymphoma histologic subtype, these findings are in agreement with the present results. to the best of our knowledge, this is the first study which demonstrates the cortactin expression in lymphoma. early study done by miglarese et al (22) on murine b lymphoid tumor cell lines hypothesize that cortactin expression is associated with transformed plasma cells and not with the terminal differentiation of normal b lymphocytes to plasma cells. the results of the present study show that the positive expression of cortactin was 98.5% and with no significant different between the types of lymphoma and between the subtypes of each type, this high expression indicate the invasiveness of all types of lymphomas were the tumor involves initially single lymph node, from where it spreads contiguously from one group of lymph nodes to another, and some time it spread to an extranodal sites. in this study the cortactin expression of tumor cells was cytoplasmic; similarly other studies found the same pattern of expression is similar.(14, 23, 24) j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 109 as for cortactin on the basis of current knowledge regarding all the published studies, no definite study could be found that used this marker to estimate its effect in the diagnosis of lymphoma of its all types and subtypes. it is worth-mentioning that in this study cortactin gave remarkable positive results. it was shown that 98.5% of all study cases were positive, hl cases show high scores than in nhl but there was no significant different between them. this suggest that additional information should be taken in consideration regarding this marker and more diffused studies should be made in this field to determine its exact effect considering lymphoma in general and its types and subtypes in more specific. a correlation was detected in icam-1 expression with cortactin expression in both hl and nhl in the present work. cortactin is a cytoskeletal protein and src kinase substrate that is frequently overexpressed in cancer and cortactin overexpression increases tumor aggressiveness, possibly through promotion of tumor invasion and metastasis. primary tumors with invasive properties usually display reduced intercellular adhesion, which allows cells to break away from the parental cell mass. tumor cells invasion the adjacent tissues either together in tightly or loosely associated cell groups, this suggests that cancer cells retain some cell-cell adhesion, even as they break away from the primary tumor. invasion of the target organ during metastasis requires certainly more stable interactions, probably mediated by various cams, which are present at the endothelial– endothelial and tumor–endothelial boundaries (25), and this could explain the correlation s between the icam-1 and cortactin. in conclusions, the high icam-1 positive expression in this study clarified that in addition to its role in cell-cell and cell-stromal interactions, it participates in proliferation, differentiation and invasion of malignant lymphoma cells. the high expression of icam-1in hl could be related to the fact that the malignant cells interact with the surrounding reactive cells and this interaction is mediated by adhesive molecules which play an important role in the pathogenesis of hl. in nhl the expression of icam-1 in intermediate and high grades was non-significantly higher than that of low grade suggesting that low grade subtypes are less aggressive in its course. the present study is the first one that used cortactin as an invasive marker for lymphoma, the highly positive expression in 100% for hl and 97.7% for nhl, may be related to the fact that all types of lymphomas could not be restricted to single site of lymph node and once it starts all the node will be affected and sometimes the lymphoma could affect tissues other than lymphoid tissues as in extranodel involvement. references 1hoffbrand av, moss pah, pettit ja. essential haematology. 5th ed. massachusetts: blackwell publishing; 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76: 783-90. 20jacob mc, agrawal s, chaperot l,giroux c,gressin r, sotto j, bensa jc, plumas j. quantitation of cellular adhesion molecules on malignant b-cell from non-hodgkin's lymphoma. leukemia 1999; 13: 142833. 21terol m, lopez-guillermo a, bosch f, villamor n, cid m, rozman c, campo e, montserrat e. expression of the adhesion molecule icam-1 in nonhodgkin's lymphoma: relationship with tumor dissemination and prognostic importance. j clin oncol 1998; 16: 35-40 22miglarese mr, mannion-henderson j, wu h, parsons jt, bender tp. the protein tyrosine kinase substrate cortactin is differentially expressed in murine b lymphoid tumors. oncogene 1994; 9:1989-97. 23gibcus jh, mastik mf, menkema l, de bock gh, kluinphm, schuuring ed, and van der wal je. cortactin expression predicts poor survival in laryngeal carcinoma. br j cancer 2008; 98: 950 – 55. 24wang g, hsieh p, hsu h, sun g, nieh s, yu ch, jin j. expression of cortactin and survivin in renal cell carcinoma associated with tumor aggressiveness. world j urol 2009; 27: 557–63. 25francavilla c, maddaluno l, cavallaro u. the functional role of cell adhesion molecules in tumor angiogenesis. semin in cancer biology 2009; 19: 298–309. athra'a f.docx j bagh college dentistry vol. 28(2), june 2016 the dental caries and pedodontics, orthodontics and preventive dentistry 98 the dental caries and some salivary constituents among a group of ten years iraqi passive smokers ali s. hussein, b.d.s. (1) athraa m. al-waheb, b.d.s., m.sc. (2) abstract background: passive smoking and dental caries affect the integrity of the health of individuals and both of them affected by sociodemographic characteristics of those individuals. this research aimed to investigate the severity of dental caries in relation to salivary magnesium and zinc of stimulated whole saliva of a group of 10 years passive smokers in comparison with normal subjects. materials and methods: the study group included 40 subjects (20boys and 20 girls), with an age of 10 years of passive smokers determined by a questionnaire. the control group included 40 normal subjects of the same gender and age of the study group. the diagnosis and recording of dental caries was measured by (d1-4mfs & d1-4mfs) index according to the criteria of muhleman (1976). the collection of stimulated whole saliva was performed under standardized condition. the salivary samples were chemically analyzed for measuring of zn and mg. results: the caries experience among study group was lower than that of control group for primary dentition but without significant difference while for permanent dentition it was equal. salivary magnesium ions concentration was lower among study group compared with control group with high significant difference. concerning salivary zinc ion concentration it was higher among study group with high significant difference among females and significant among males. among males of study group, magnesium correlated negatively significantly with d1, the same correlation was recorded among females where it was with d1and d2 while it was correlated positively highly significantly with d1 of control group and significantly with d1 and d3 among males of control group. for salivary zinc it was correlated negatively highly significantly with d3 of study group. conclusion: passive smoking has no effects on dental caries rather than it affects certain salivary constituents. key words: dental caries, passive smoking, magnesium, zinc. (j bagh coll dentistry 2016; 28(2):98-102). introduction breathing smoke of other peoples is known as involuntary, passive or secondhand smoking. it can also called as ‘environmental tobacco smoke’. smokers and non-smokers alike inhale second hand smoke. inhaling tobacco smoke is an unavoidable consequence of being in an environment that filled with smoke (1).passive smoking, especially among young children, may cause serious health hazards (2). tobacco smoking, now and in the past, has been a custom and addiction primarily of men, leaving women and children as the majority of the world’s passive, or involuntary, smokers. biomarkers of exposure are compounds that can be measured in biological materials such as blood, urine, or saliva (3). there is evidence that cigarette smoking increases the risk for dental caries development among individuals (4). studies in young adults revealed an association between cigarette smoking and tooth loss resulting from dental caries and were recorded that plaque scores in addition to decayed, missing, filled teeth (dmft) scores were lower significantly among non-smokers than smokers (5,6); while a study carried out in 2006 failed to find a positive association between caries experience and passive smoking in japanese children (7). 1. master student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. 2. professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. magnesium (mg) ion is a normal constituent of dental enamel, dentin, and bone; it is existing in a relatively high concentrations in subsurface layer of enamel, its level dental plaque have been associated inversely with caries experience. magnesium presents in submandibular saliva with higher level than those in parotid saliva and vary inversely with salivary flow rate (8,9). magnesium is a mineral that helps with the formation of teeth (10). zinc (zn) is an essential trace element that is present in small amounts in all tissues and body fluids, including saliva (11). influence of trace elements on the prevalence of dental caries is a detectable subject however; sufficient evidence has been accumulated to suggest the cariostatic effect of trace elements. zinc was considered to be a doubtful element among trace element that inhibits caries development(12).no previous iraqi studies were conducted concerning the effects of passive smoking on dental caries and some salivary constituents, for that reason this study was done. materials and methods the study group included 40 student (20 boys, 20 girls) aged 10 years old; they were regarded as passive smokers and included in the study according to questionnaire were they should met the following criteria: ß one of the parents of the subject is smoker. j bagh college dentistry vol. 28(2), june 2016 the dental caries and pedodontics, orthodontics and preventive dentistry 99 ß the number of cigarettes smoked per day are at least 20. ß the smoking is indoors. ß the exposure of subject to environmental smoking was at least for 5 years. the control group included students machining in number, age and gender with the study group with parents who are not smoke. caries-experience was diagnosed and recorded according to decayed, missing and filling surface index (dmfs and dmfs) indices for permanent and primary teeth respectively described by who 1987(13). in addition, the decay fraction of index was recorded according to lesion severity in accordance to the criteria described by muhlemann (14). the salivary samples of stimulated saliva were collected under standardized conditions following the instruction cited by tenovuo and largerlof (15). salivary magnesium and zinc were estimated biochemically by using atomic absorption, data analysis was conducted by application of spss program (version 16). results results showed that there is no significant statistically differences between males and females concerning caries experience and salivary constituents among study or control. for that reason the whole sample were considered one without subgrouping according to gender. caries experiences (medians) among study and control groups for primary and permanent dentition are shown in table 1 and 2 respectively. medians of dmfs among study group were lower as compared to control group but without significant difference statistically (p>0.05) while median of dmfs among study and control group were equaled. in the study group and control groups decay component of dmfs and dmfs index represented the highest proportion followed by filling and missing fractions for both primary and permanent dentition. the salivary constituents (medians) among study and control groups are shown in table 3. results revealed that magnesium ions concentration which is measured by (mg/l)was lower among study group as compared with control group with highly significant difference, while concerning zinc zinc ions concentration which is measured by (µg / d.l), it was found that study group was higher compared with control group, the difference was statistically high also. correlation coefficient between salivary magnesium and zinc with dental caries among study and control group is shown in table 4, where its revealed that magnesium correlated positively highly significantly with d1 among control group while zinc was correlated negatively highly significantly with d3 among study group. correlation coefficient between salivary magnesium and zinc with dental caries among males of study and control group is shown in table 5, where it's revealed that magnesium correlated significantly in both directions; positively with d1 and d3 and negatively with d1 among males of control group. table 6 showed the correlations among females of study and control group, where magnesium correlated negatively significantly with d1 and d2 among females of study group. table 1: caries experience and caries severity for primary dentition among study and control groups study group control group group difference variables min. max. median mean ±sd min. max. median mean ±sd mannwhitney u-test ztest pvalue ds 0 25 6 6.20 5.26 0 37 7 8.03 7.05 667.5 1.27 0.20 ms 0 10 0 1.25 2.94 0 5 0 0.50 1.52 734 1.06 0.28 fs 0 0 0 0 0 0 0 0 0 0 800 0 1 dmfs 0 25 6 7.45 5.99 0 37 7.5 8.53 7.19 723 0.74 0.45 d1 0 3 0 0.63 0.87 0 3 0 0.50 0.78 745.5 0.60 0.54 d2 0 6 0 0.50 1.15 0 7 0 0.73 1.52 753.5 0.57 0.56 d3 0 14 3.5 3.90 3.27 0 12 3.5 4.23 3.72 769 0.30 0.76 d4 0 14 0 1.13 2.84 0 30 0 2.58 5.29 635.5 1.30 0.05 d.f=78 j bagh college dentistry vol. 28(2), june 2016 the dental caries and pedodontics, orthodontics and preventive dentistry 100 table 2: caries experience and caries severity for permanent dentition among study and control groups study group control group group difference variables min. max. median mean ±sd min. max. median mean ±sd mannwhitney u-test ztest pvalue ds 0 9 4 3.70 1.98 0 10 3.5 3.75 2.92 766 0.33 0.74 ms 0 0 0 0 0 0 10 0 0.25 1.58 780 1 0.31 fs 0 1 0 0.03 0.16 0 2 0 0.05 0.32 799.5 0.01 0.98 dmfs 0 9 4 3.37 2.00 0 12 4 4.08 3.11 795 0.04 0.96 d1 0 6 2 2.08 1.58 0 6 1 1.53 1.62 618.5 1.78 0.07 d2 0 5 1 1.15 1.44 0 8 1 1.38 1.84 776 0.26 0.80 d3 0 6 0 0.43 1.22 0 6 0 0.53 1.30 747 0.74 0.45 d4 0 2 0 0.05 0.32 0 5 0 0.35 1.25 758.5 1.05 0.29 d.f=78 table 3: salivary constituents among study and control groups variables study group control group group difference min. max. median mean ±sd min. max. median mean ±sd mann-whitney u-test z-test p-value mg 0.33 0.69 0.49 0.50 0.09 0.6 0.81 0.66 0.68 0.06 72.5 7.00 0.00** zn 2.5 6.4 4.3 4.39 0.72 2.1 5.5 3.65 3.65 0.89 450 3.37 0.00** d.f=78, **highly significant (p < 0.01) table 4: correlation coefficient between salivary magnesium and zinc and caries experience among study and control groups (ds grades, dmfs, ds grades and dmfs) variables mg zn study group control group study group control group r p r p r p r p d1 d2 d3 d4 dmfs -0.25 -0.09 0.09 0.02 0.14 0.10 0.56 0.56 0.88 0.38 0.48 0.11 -0.02 0.02 -0.01 0.00** 0.47 0.87 0.57 0.92 -0.02 -0.05 -0.19 0.00 -0.04 0.88 0.74 0.23 0.98 0.77 -0.10 0.23 -0.12 0.01 -0.02 0.52 0.14 0.42 0.95 0.86 d1 d2 d3 d4 dmfs 0.06 -0.12 0.07 -0.11 -0.08 0.70 0.42 0.63 0.94 0.59 0.25 -0.13 -0.19 -0.03 0.06 0.11 0.40 0.23 0.83 0.70 -0.02 -0.23 -0.14 0.23 -0.20 0.88 0.14 0.00** 0.15 0.20 0.12 0.24 0.05 0.15 0.17 0.43 0.12 0.73 0.34 0.26 **highly significant (p < 0.01) table 5: correlation coefficient between salivary magnesium and zinc and caries experience among males of study and control groups (ds grades, dmfs, ds grades and dmfs) variables mg zn study group control group study group control group r p r p r p r p d1 d2 d3 d4 dmfs -0.12 -0.14 0.25 0.26 0.38 0.60 0.53 0.28 0.26 0.09 0.53 0.02 -0.22 -0.14 -0.31 0.01* 0.91 0.33 0.55 0.17 0.12 -0.01 -0.42 -0.24 -0.31 0.60 0.94 0.06 0.30 0.17 0.00 0.40 -0.22 0.10 0.00 0.98 0.07 0.34 0.66 0.98 d1 d2 d3 d4 dmfs -0.45 0.32 0.35 -0.14 -0.11 0.04* 0.15 0.12 0.55 0.62 0.24 -0.44 -0.55 -0.04 -0.22 0.29 0.05 0.01* 0.85 0.33 0.07 -0.39 -0.37 0.30 -0.14 0.77 0.08 0.10 0.19 0.54 0.13 0.21 0.02 0.30 0.41 0.56 0.37 0.91 0.91 0.07 * significant (p < 0.05) j bagh college dentistry vol. 28(2), june 2016 the dental caries and pedodontics, orthodontics and preventive dentistry 101 table 6: correlation coefficient between salivary magnesium and zinc and caries experience among females of study and control groups (ds grades, dmfs, ds grades and dmfs) variables mg zn study group control group study group control group r p r p r p r p d1 d2 d3 d4 dmfs -0.36 0.02 -0.08 -0.20 -0.10 0.11 0.90 0.72 0.39 0.66 0.43 0.19 0.20 0.40 0.31 0.05 0.41 0.38 0.07 0.17 -0.24 -0.05 0.06 0.30 0.19 0.29 0.80 0.79 0.19 0.40 -0.21 0.04 0.03 -0.13 -0.03 0.36 0.85 0.89 0.58 0.87 d1 d2 d3 d4 dmfs -0.44 -0.05 -0.10 -0.09 0.04* 0.02* 0.65 0.70 0.26 0.11 0.15 -0.01 0.32 0.25 0.62 0.50 0.86 0.16 -0.11 -0.11 -0.42 -0.22 0.62 0.62 0.05 0.33 0.06 0.31 0.11 -0.02 -0.06 0.78 0.18 0.61 0.93 0.78 * significant (p < 0.05) discussion the data of present study showed that there is no significant difference for caries experience as measured by dmfs/dmfs index between study and control groups., the same results were recorded by previous studies (16,17). some studies suggested that passive smoking was positively associated with dental caries (18,19), while another study reported no association between passive smoking and dental caries(20,21). the heterogeneity of these results among studies might be explained by differences in characteristics, smoking habits, and life style of the populations examined, the study design used, and potential confounders considered. in particular, few of the studies on the association between passive smoking and dental caries controlled for potential confounders, such as socioeconomic status, diet, and oral health behaviors. other limitations may also influence the interpretation of the current results. as this study is cross-sectional, the temporal nature of the association between passive smoking and dental caries could not be examined. passive smoking was assessed by questionnaire reports and was not validated by measurements of biomarkers, such as salivary, serum or urine cotinine levels. using questionnaires may result in misclassification from recall bias and response bias due to parents' feelings of guilt for smoking in the presence of their children (22). regarding concentration of salivary magnesium ion, results showed that magnesium ion concentration was lower among study group including males and females as compared to control group with highly significant difference between them (23), while another study found no significant difference between salivary minerals between smokers and non smokers (24). this decrease in salivary magnesium explained by eliasson et al. (25) who had assumed that some of the abnormalities noted in smokers did not seem to be mediated by nicotine. whereas influence of nicotine on reducing the body weight and indirectly on decreasing the electrolytes. results of present study revealed higher salivary zinc concentration among study group as compared to control group with high significant difference, the same result recorded for females but regarding males the difference was statistically significance. concerning magnesium ion results revealed negative correlation with dental caries indicated by d1 among males of the study group which was significance and with d1 and d2 among females of the study group which was also significance and this agreed with other studies (26,27) which recorded among healthy individuals; while among control group, the correlation was positive and highly significant with d1 and significant with d1 and d3 among males of the study group, this result explained by featherstone (28) who described magnesium as a caries promoting mineral as it inhibits remineralization. salivary zinc ions concentration was founded to be correlated inversely highly significant with dental caries indicated by d3 in the study group, however this can be explained by the study of chandra et al.(29) which found that high level of zinc lead to greater mineralization and accumulation of zinc quantities on surface enamel that become more caries resistance. deficiency of micro nutrients like zinc can influence amount and composition of saliva and reduce protective effect of saliva (30). increased susceptibility to dental caries in zinc-deficient animals might be mediated by alterations in salivary proteins that are associated with the maintenance of tooth structure (31). j bagh college dentistry vol. 28(2), june 2016 the dental caries and pedodontics, orthodontics and preventive dentistry 102 references 1. international agency for research on cancer (iarc). iarc monographs on the evaluation of carcinogenic risks to humans volume 83 tobacco smoke and involuntary smoking. iarc. france 2004. 2. world health organization. tobacco free initiative. international consolation on environmental tobacco smoke and child health report, who, geneva, 1999. 3. who report on the global tobacco epidemic, 2009: implementing smoke free environments. geneva, world health organization, 2009. 4. aguilar-zinser v, irigoyen me, rivera g, maupome g, sanchez-perez l, velazquez c. cigarette smoking and dental caries among professional truck drivers in mexico. caries res 2008; 42(4): 255-62. 5. ojima m, hanioka t, tanaka k, aoyama h. cigarette smoking and tooth loss experience among young adults: a national record linkage study. bmc public health 2007;7:313. 6. al-habashneh r, al-omari ma, taani dq. smoking and caries experience in subjects with various form of periodontal diseases from a teaching hospital clinic. int j dent hyg 2009;7(1):55-61. 7. tanaka k, hanioka t, miyake y, ojima m, aoyama h. association of smoking in household and dental caries in japan. j public health dent 2006;66(4):279289. 8. suddick rp, hyde rj, feller rp. salivary water and electrolytes and oral health. the biologic basis of dental caries: an oral biology text book, harper and row publishers 1980:132-147. 9. larsen mj, bruun c. caries chemistry and fluoride mechanisms of action in textbook of clinical cariology. 2nded. kopenhagen: munksgard; 1994. pp. 231-257. 10. patrick p. calcium. report of london laboratory services group. 2003. pp.1–2. 11. burguera-pascu m, rodrı´guez-archilla a, burguera jl et al. flow injection on-line dilution for zinc determination in human saliva with electrothermal atomic absorption spectrometry detection. anal chim acta 2007; 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64: 184-6. 20. schafer te, adair sm. prevention of dental disease; the role of the pediatricion. pediatr clin north am 2000;47: 1021-4. 21. tanaka k, hanioka t, miyake y, ojima m, aoyama h. association of smoking in household and dental caries in japan. j public health dent 2006; 66(4):27981. 22. tanaka k, miyake y, arakawa m, sasaki s, ohya y. household smoking and dental caries in schoolchildren: the ryukyus child health study. bmc publ health 2010; 10: 335. 23. rogers i, emmett p. alspac study team. the effect of maternal smoking status, educational level and age on food and nutrient intakes in preschool children: results from the avon longitudinal study of parents and children. eur j clin nutr 2003; 57: 854-64. 24. erdemir eo,erdemir a. the detection of salivary minerals in smokers and non-smokers with chronic periodontitis by the inductively coupled plasmaatomic emission spectrophotometry technique. j periodontol 2006; 77(6): 990-5. 25. eliasson m, hägg e, lundblad d, karlsson r, bucht e. influence of smoking and snuff use on electrolytes, adrenal and calcium regulating hormones. acta endocrinol (copenh) 1993; 128(1): 35-40. 26. curzon m, crocker d. relation of trace element in human tooth enamel to caries. arch oral biol 1978;23. 27. al –zahawi s, al-refai a. the relationship between calcium, magnesium and inorganic phosphate of human mixed saliva and dental caries. must dent j 2007;4(2): 165-61. 28. featherstone j. magnesium. in: curzon m, cutress t, eds.trace elements and dental caries. boston: psg. inc.; 1983. 29. chandra s, chandra s, chandra. textbook of operative dentistry 1st ed. new delhi: jaypee brother of medical publisher (p) lt; 2008. 30. monyhan p. food and dietery factors that prevent dental caries.quintes int 2007; 38: 320-4. 31. johnson da, alvares o. zinc deficiency-induced changes in rat parotid salivary proteins. j nutr 2013; 114: 1955-64. sami f.doc j bagh college dentistry vol. 25(2), june 2013 vertical analysis of orthodontics, pedodontics and preventive dentistry149 vertical analysis of patients with late lower arch crowding sami k. al-joubori, b.d.s., m.sc. (1) ali m. al-attar, b.d.s., m.sc. (2) mustafa m. al-khatieeb, b.d.s., m.sc. (2) abstract background: because of many factors play a role in the developing of late lower arch crowding, therefore the objective of the current study is to do vertical analysis for subjects with late lower dental arch crowding. the conducted study is the first attempt to do vertical analysis for iraqi subjects with late lower arch crowding to see if there is a vertical discrepancy in such patients. subjects and methods: eighty subjects were selected according to certain inclusion criteria from patients attending the orthodontic department in the college of dentistry, baghdad university, patients ranged between 18-25 years old. the 80 patients were divided into two groups (crowding and normal), 40 patients each (20 males and 20 females). a study cast of lower dental arch was obtained, and then nance's space analysis made for each cast, cephalometric radiographs were also taken for each patient involved in the current study and digitization was done to calculate nine vertical linear and twelve angular measurements. results: most of linear measurements showed higher mean values in crowding than normal subjects except s-go, argo, and pfh/afh, also subjects with crowding had significantly higher (p<0.05) anterior facial height (ans-me) than normal subjects, and that difference occurred only in the lower part of the face, the jaraback ratio (pfh/afh) was also low in crowding subjects, also higher mean values of ladh, uadh and updh in crowding group, may be due to compensatory over eruption of teeth as a result a bite opening occurred, indicating that patients with crowding have tendency toward posterior rotation. regarding the angular measurements, subjects (total males and females) with crowding had larger mean values than normal. there were no interactions between total mean values of normal and crowding subjects for any outcome angular parameter, except four of the twelve angular measurements (sn-mp, occ-mp, pp-mp, and sum s.a.g angles) showed an interaction, with females in both normal and crowding groups exhibited higher mean values than males. conclusions: subjects with late lower arch crowding can have and/or affect on the vertical dimension, and the vertical discrepancy in late lower arch crowding should be considered during diagnosis and treatment plane of orthodontic cases, active treatment, and retention phase, in order to have stable end result in long term prognosis in orthodontics. keywords: vertical analysis, late lower arch crowding. (j bagh coll dentistry 2013; 25(2):149-154). في الفك المتأخر السني الدراسة لتقیم البعد العمودي للرأس لالشخاص ذوي التراكبعملنا ھذه , تلعب دورا في تكون تراكب االسنان المتأخر للفك السفليبسبب العوامل الكثیرة التي :الخالصة تقویم األسنان في ا فرعراجعومن المرضى الذین اختیروا وفق بعض الضوابط , تتألف عینة البحث من ثمانین شخصا .االولى في ھذا المجال للمرضى العراقیین ھيالدراسة ھذهو تعتبر ,السفلي كل مجموعة تتألف من اربعین شخصا , )االعتیادیون وذوي االسنان المتراكبة(الى مجموعتین وزعوااالشخاص الثمانون , عاما 2518تراوحت اعمارھم بین سنان، جامعة بغداد،كلیة طب األ . وتم اخذ اشعات قیاسیة للرأس وتم تحلیل تسعة قیاسات خطیة واثنى عشر زاویة, سو عمل لھا تحلیل الفراغات السنیة بطریقة نان القوالب التشخیصیة للفك السفلي صنعت). انثى 20ذكرا و 20( و , ar-go و s-go ابعادما عدا من ما ھو علیھ في االشخاص االعتیادیین وقد تبین من نتئج البحث بأن معظم القیاسات الخطیة كانت اعلى في االشخاص ذوي التراكب السني للفك السفلي pfa/afh ,وان , ة في بعد الوجھ االمامي وھذا االختالف وجد في الجزء السفلي من الوجھظللفك السفلي لدیھم قیمة معنویة عالیة وملحوالمتأخرشخاص ذوي التراكب السني كذلك االuadh , ladh,وupdh على ان مما یدل ادة نمو االسنان العمودي نتیجة العضة المفتوحةویمكن ان یعزى ھذا االختالف الى زی, اعلى في المجموعة المتراكبة بینما نسبة جاراباك كانت منخفضة بین مجموع متوسطات القیم ألي ةظاختالفات معنویھ ملحوتكن ھناك اما فیما یخص القیاسات الزاویة فلم, لدیھم میل نحو الدوران الخلفي للفك السفلي للفك السفلي االشخاص ذوي التراكب السني نستنتج من ھذه الدراسة بأنھ یوجد فرق معنوي ملحوظ في قیاسات الوجة العمودیة بین االشخاص , )s.a.gو مجموع sn-mp,occ-mp ,pp-mpٍ(زاویة ماتمعلاال في اربع معلمة المستقرة التقویمیةجیة للحصول على افضل النتائج وھذا الفرق یجب ان یأخذ بعین االعتبارأثناء التشخیص ووضع الخطة العال, للفك السفلي المتأخر االعتیادیین واالشخاص ذوي تراكب السني .في عالج تقویم االسنان الطویلة االمد introduction as crowding is considered as one of the most common malocclusion faced by an orthodontist during the professional carrier (1,2). van der linden in 1974 has classified crowding on the basis of etiology into the categories of primary, secondary, and tertiary crowding. primary crowding is defined as inherent discrepancy of tooth size and jaw size discrepancy, mainly of genetic origin. secondary crowding is that type caused by environmental factors acting on the dentition, the most important of these is premature loss of deciduous teeth. tertiary crowding is that type developed in the middle or late teens. it has also been referred to as late crowding or postadolescence crowding (3). (1)assistant professor, orthodontic department, dental college, university of baghdad. (2)lecturer, orthodontic department, dental college, university of baghdad. the crowding may affect the whole arch or be localized to the anterior segment, though crowding in the anterior segment is reported to be the more common than in the posterior segment of the lower arch(4). a variety of factors have been reported to be responsible for lower incisor segment such as inclination of mandibular incisors during mixed dentition (4), inclination and size of mandibular permanent first molars (5), high mandibular plane angles, short mandibular body lengths, great upper face height, and small vertical dimensions in upper posterior segments (6). premature loss of deciduous teeth, morphology of the mandibular incisors and size of dental arch are also seemed to be contributing factors to lower incisors crowding (7-12). the role of the third molar has been studied and debated at some length, and there is evidence to support the view that, in the untreated lower j bagh college dentistry vol. 25(2), june 2013 vertical analysis of orthodontics, pedodontics and preventive dentistry150 arch, the third molar or lack of space for it may contribute to the development of crowding farther forward (13,14). it is the nevertheless obvious that the third molar is not the only factor responsible for the development of such crowding, bjork in 1969 suggested that extreme mandibular rotation could result in increased lower arch crowding (15), also complicated facial development may be responsible for the late crowding (16). researchers claimed that lower arch crowding was caused by specific pattern of growth and type of skeletal pattern that is susceptible to crowding at the beginning of adolescence or even at the late adulthood (6). studies showed a change in vertical pattern of patient can affect the lower incisor inclination (17,18). however no study has aimed in detailed findings the vertical analysis of the patient with late lower arch crowding, therefore the objective of the current study is to do vertical analysis for patients with late lower dental arch crowding. subjects and methods out of 350 patients attending the orthodontic department in the college of dentistry, baghdad university, 80 patients were selected, dental study casts and lateral cephalometrics were evaluated in this study, the age of the patients ranged between 18-25 years old. all the patients were fulfilled the criteria of the sample selection which were: 1. the patients have not undergone previous orthodontic, orthopedic, facial, and surgical treatments. 2. they have complete permanent dentition, with no supernumerary, missing, or impacted tooth. 3. they have class one skeletal relation (anb angle equals to 2-4 degrees). 4. the third molars were excluded. 5. no history of trauma to the dento-facial structures. 6. no massive carious lesion or bulky restorations. the sample (80 patients) was divided into two groups, the first group composed of 40 patients with normal lower arch (20 males and 20 females), and the second group composed of 40 patients with late lower arch crowding (20 males and 20 females). a study cast of lower dental arch was obtained by taking an alginate impression and poured with stone, and then nance's space analysis (19) made for each cast. space condition= space available – space required space available has been calculated as the length of a brass wire modeled in relation to the individual shape of the lower arch form right to left mesial marginal ridge of the lower first molar passing through incisal margins and buccal cusps of the posterior teeth. space required has been calculated as the sum of the mesio-distal width of all teeth between the mesial contact points of the right and left lower first molar by using digital boley gauge caliber as shown in figure 1, negative values for space condition indicating crowding (19). cephalometric radiographs were taken for each patient involved in the current study with planmeca ® (il, usa) digital x-ray unit. each lateral cephalometric radiograph was analyzed by autocad (2011) software computer program to calculate nine vertical linear and twelve angular measurements (figures 2 and 3). cephalometric landmarks: (figure 2) 1. point n (nasion): the most anterior point of nasofrontal suture in the mid-sagittal plane (21 23). 2. point s (sella): the center of the shadow of the sella turcica (1,20,21). 3. point gn (gnathion): the most anterior and inferior point of the bony chin, it is located where the bisector of the angle formed between the facial plane and the mandibular plane intersects the outline of the symphysis (20,21). 4. point ar (articulare): the point of the intersection of the posterior margin of the ascending ramus and the outer margin of cranial base (20,21). 5. point go (gonion): the point of intersection of the tangent to the posterior margin of the ascending ramus and the mandibular base (20,21). 6. point me (menton): the most caudal point in the outline of the symphysis. it is regarded as the lowest point of the mandible (20,21). 7. point ans (anterior nasal spine): the anterior tip of the sharp bony process of the maxilla at the lower margin of the anterior nasal opening (1,20,21). 8. point pns (posterior nasal spine): the posterior spine of the palatine bone constituting the hard palate coincides with the lowest point of the pterygomaxillary fissure (1,20,21). 9. point b (supramentale): the most posterior midline point in the concavity of the mandible between the most superior point on the alveolar bone overlaying the roots' tips of mandibular incisors (20, 21). vertical linear measurements: (figure 2): nine vertical linear skeletal measurements are j bagh college dentistry vol. 25(2), june 2013 vertical analysis of orthodontics, pedodontics and preventive dentistry151 recorded to the nearest half millimeter: 1. n-me (total anterior facial height): the distance from point n to point me(22). 2. ans-me (lower anterior facial height): the distance from anterior nasal spine to menton(22). 3. s-go (total posterior facial height): the distances from point s to point go.(20, 22). 4. ar-go (ramus height): the distance from point ar to point go (22). 5. ladh (lower anterior dental height): it is the perpendicular distance from lower incisal edge projected at a right angle to the mandibular plane (go-me) (23). 6. lpdh (lower posterior dental height): it is the perpendicular distance from mesiobuccal cusp of the lower first molar to the mandibular plane (24) . 7. uadh(upper anterior dental height) which is the perpendicular distance from upper incisal edge projected at a right angle to the palatal plane (ans-pns)(23) . 8. updh (upper posterior dental height) which is the perpendicular distance from the mesiobuccal cusps of the upper first molar to the palatal plane (25) . 9. pfh/afh (posterior facial height/anterior facial height): it is the ratio of the total posterior facial height (s-go) to the total anterior facial height (n-me)(20-23) . angular measurements:(figure 3) 1. n.s.gn (y-axis): this angle determines the position of the mandible relative to the cranial base (20). 2. n.s.ar (saddle) angle: it is the angle between the anterior and posterior cranial base, this angle determines the position of glenoid fossa (19-26). 3. s.ar.go (articular) angle: it is the angle between the posterior border of the ramus and posterolateral cranial base (19). 4. ar.go.me (gonial) angle: it is the angle between the posterior border of the ramus (ar-go), and the lower border of the mandible or mandibular plane (go-me); it expresses the form of the mandible and plays a role in growth prognosis (19,25). 5. sn-mp angle: it represents the inclination of the mandible to the anterior cranial base (20). 6. sn-occ angle: it represents the inclination of the occlusal plane to the anterior cranial base (20,21) 7. occ-mp angle: this angle is formed between occlusal and mandibular planes, this angle is important for assessing the prognosis for opening the bite (20,27-29). 8. pp-mp (basal plane) angle: it is the angle of inclination of the mandible to the maxillary base. this angle serves to determine rotation of the mandible (20). 9. 1 -pp angle (dental):it is the angle between the long axis of the most prominent upper incisor with the palatal plane posteriorly(20). 10. ī-mp angle (dental):i t is the angle between the long axis of the most prominent lower incisor with the mandibular plane posteriorly (20,27) . 11. ii angle (dental): interincisal angle between the long axis of the upper and lower central incisors posteriorly (20). 12. sum s.a.g: it is the sum of saddle, articular, and gonial angles (20). statistical analysis all the data of the sample were subjected to computerized statistical analysis using spss software comport program version 15, in which the descriptive statistics included mean, and standard deviation, and the inferential statistics included student's t –test , probability values were considered significant at p<0.05, and highly significant at p<0.01. results the descriptive statistics (mean and standard deviation) for linear and angular measurements are shown in tables 1 and 2. regarding the linear measurements, most of these measurements showed higher mean values in crowding than normal subjects except s-go, ar-go, and pfh/afh, in which the crowding group showed lower mean values as demonstrated in table 1. on the other hand, there were highly significant differences (p<0.01) between normal and crowding subjects for total males and total group (total males-females) in regard to ans me, ladh, uadh, and updh measurements using student's ttest, because these measurements showed higher mean values in total crowding subjects than normal subjects, while there was significant difference (p<0.05) between normal and crowding subjects for total group (total males-females) regarding pfh/afh parameter, this is due to the lower mean values in total crowding than normal subjects, in addition the total anterior facial height (n-me) showed no significant difference (p>0.05) using student's t test, as illustrated in table 1 . regarding the angular measurements, subjects (total males and females) with crowding had larger mean values than normal. there were no interactions between total mean values of normal and crowding subjects for any outcome angular parameter, except four of the twelve angular j bagh college dentistry vol. 25(2), june 2013 vertical analysis of orthodontics, pedodontics and preventive dentistry152 measurements (sn-mp, occ-mp, pp-mp, and sum s.a.g angles), exhibited statistically significant differences at p<0.05 (for sum s.a.g angles) and highly significant differences at p<0.01 (for sn-mp, occ-mp, and pp-mp angles) between normal and crowding subjects using student's ttest as shown in table 2. on the other hand the sn-mp, occ-mp, pp-mp, and sum s.a.g parameters showed that females in both normal and crowding groups exhibited higher mean values than males, therefore there was a significant difference (p<0.05) between normal and crowding subjects for total group (total males-females) in regard to sum s.a.g angles, and highly significant differences (p<0.01) in regard to sn-mp, occ-mp, and pp-mp angular measurements using student's ttest as shown in table 2. discussion subjects falling within 18-25 years old were chosen because of the fact that most of the growth would have been completed by that time. also a constant skeletal pattern gets established, as schudy (30) said that the facial patterns once established did not change much. studies have shown that the growth changes of the facial tissues, although not completed occurred predominantly before the age 18 years (31, 32). the current study pointed on vertical parameter of facial morphology between normal and crowding subjects because many orthodontists deal with crowding, which is one of the most frequent types of malocclusion as only tooth-arch size discrepancy, in fact many other factors play a role in the developing of crowding, one of the most significant is vertical discrepancy and it is proved that the most difficult cases to be treated and which have the least favorable prognosis are frequently those in which there is a vertical discrepancy. this fact was amply by the fact that relapses in the vertical dimension of an orthodontically treated case is the first sign to be noted in patients with late lower arch crowding (33). lower anterior facial height ans-me was significantly higher in crowding than normal subject, while total anterior facial height (n-me) showed no significant difference, thus indicating that the difference occurred only in the lower part of the face, this result agreed with rasul et al (18) , and disagreed with miethke and menthel (33). the significant low mean values of jaraback ratio (pfh/afh) in crowding than normal subjects may be due to the higher value of posterior facial height (s-go) in normal than crowding subjects, this result agreed with leighton and hunter (5). the significant higher mean values of ladh, uadh and updh in crowding group may be due to compensatory over eruption of teeth as a result, a bite opening occurred, indicating that patients with crowding have tendency toward posterior rotation. sn-mp, occ-mp, pp-mp and sum s.a.g. angular measurements were significantly higher in crowding than normal subject, indicated that patients with crowding have tendency toward posterior rotation, this come in accordance with sakuda et al (6), leighton and hunter (5), and rasul et al (18), who they found hyper-divergent cases showed the highest percentage of lower incisor crowding, since the new position of the dentition should be compatible with the dynamics of the muscular and occlusal forces in all planes, thus there is a serious risk of extreme migration after extraction in vertical facial types, in other words, posterior rotation case, and secure anchorage is required (5,6,18) . it can be concluded 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braz oral res 2006; 20(2):167-71. 18. rasul g, alikhan a, qiam f. the role of vertical parameters in the development of lower incisor crowding amongst patients. pakistan oral dent j 2012; 32(2): 244-47. 19. nance hn. limitations of orthodontic treatment. ame j orthod oral surg 1947; 33: 253-301. 20. rakosi t. an atlas and manual of cephalometric radiology. 2nd ed. london: wolfe medical publication; 1982. pp.241. 21. jacobson a, caufield p. introduction to radiographic cephalometry. philadelphia: lea & febiger; 1985. pp.37,130. 22. biggerstaff rh, allen rc, tuncay oc, berkowitz j. a vertical cephalometric analysis of the human craniofacial complex. am j orthod 1977; 72(4): 397405. 23. tsai hh. cephalometric characteristics of bimaxillary dentoalveolar protrusion in early mixed dentition. j. clin pediat dent 2002; 26(4): 363-370. 24. haralabakis nb, yiagtzis sc, toutountz-akis nm.cephalometric characteristics of open bite in adults: a three dimensional cephalometric evaluation. int j adult orthog surg 1994; 9(3): 223–231. 25. katsaros c, berg r. anterior open bite malocclusion: a follow up study of orthodontic treatment effects. eur j orthod 1993; 15(3): 273–280. 26. jarabak jr, fizzell fa. technique and treatment with light wire edgewise appliances. 2nd ed. st. louis: c.v. mosby co; 1972. pp.1224. 27. nanda sk. growth patterns in subjects with long and short faces. am j orthod 1990; 98: 247-58. 28. steiner cc. cephalometrics for you and me. am. j. orthod. 1953; 39:729. 29. tweed ch. the frankfort mandibular plane angle in orthodontic diagnosis classification, treatment planning and prognosis. am j orthod 1946; 32: 175230. 30. schudy ff. vertical growth versus anteroposterior growth as related to function and treatment. angle orthod 1964; 34: 75–93. 31. formby wa, nanda rs, currier gf. longitudinal changes in the adult facial profile. am j orthod dentofac orthop 1994; 105: 464–76. 32. skieller v, björk a, linde-hansen t. prediction of mandibular growth rotation evaluated from a longitudinal implant sample. am j orthod 1984; 86: 359–370. 33. miethke rr, behm-menthel a. correlations between lower incisor crowding and lower incisor position and lateral craniofacial morphology. am j orthod dentofac orthop 1988: 94(3):231-39. figure 3: cephalometric landmarks and angular measurements figure 1: (1) lower dental cast, (2) brass wire and (3) boley gauge caliber. figure 2: cephalometric landmarks, and vertical linear measurements j bagh college dentistry vol. 25(2), june 2013 vertical analysis of orthodontics, pedodontics and preventive dentistry154 table 1: descriptive and comparative statistics for linear measurements in normal and crowding subjects, in males, females, and total groups normal versus crowding crowding normal total (df=78) female (df=38) male (df=38) total female male total female male pvalue ttest md pvalue ttest md pvalue ttest md n=40 n=20 n=20 n=40 n=20 n=20 0.23 1.2 -2.3 0.289 1.07 1.9 0.295 1.06 2.4 136.6 131.6 141.6 134.3 129.6 139.12 mean n-me 8.71 6.7 7.6 7.6 4.52 7.12 s.d. 0 4.6 -5.4 0 3.8 5.47 0.001 3.73 5.2 79.9 77.3 82.5 74.5 71.8 77.27 mean ans-me 5.7 5.5 4.6 4.51 2.99 4.15 s.d. 0.375 0.89 1.5 0.644 0.46 0.82 0.266 1.12 2.15 86.9 82.5 91.3 88.4 83.3 93.45 mean s-go 6.7 4.2 5.9 8.11 6.65 6.11 s.d. 0.28 1.08 1.4 0.564 0.58 0.82 0.238 1.19 2 52.5 49.6 55.4 53.9 50.4 57.4 mean ar-go 5.5 4.06 5.4 6.04 4.86 5.11 s.d. 0 3.68 -3 0.002 3.27 3.17 0.007 2.8 2.7 48.7 46.9 50.5 45.7 43.7 47.82 mean ladh 3.8 3.6 3.2 3.2 2.36 2.72 s.d. 0.068 1.84 -1.5 0.017 2.49 2.42 0.665 0.43 0.45 36.8 35.9 37.7 35.3 33.4 37.3 mean lpdh 3.04 3.2 2.6 3.8 2.91 3.8 s.d. 0.001 3.4 -2.3 0.045 2.07 1.6 0.005 2.97 2.95 34.2 33.05 35.4 31.9 31.4 32.5 mean uadh 3.2 2.9 3.06 2.6 1.82 3.2 s.d. 0.004 2.93 -1.7 0.229 1.22 0.95 0.002 3.34 2.5 28.1 26.7 29.6 26.4 25.8 27.1 mean updh 2.9 2.7 2.5 2.2 2.06 2.19 s.d. 0.041 2.08 2.5 0.208 1.2 2.02 0.094 1.71 2.9 63.1 62 64.3 65.6 64.02 67.24 mean pfh/afh 5 4.9 5 5.6 5.07 5.81 s.d. table 2: descriptive and comparative statistics for angular measurements in normal and crowding subjects, in males, females, and total groups normal versus crowding crowding normal total(df=78) female(df=38) male (df=38) p value t test md p value t test md p value t test md total female male total female male n=40 n=20 n=20 n=40 n=20 n=20 0.208 1.27 -1.43 0.69 0.4 0.8 0.154 1.45 2.2 70.4 70.8 70 68.9 70 67.8 mean n.s.gn 5 4.6 5.3 5.11 5.8 4.07 s.d. 0.449 0.66 1 0.299 1.05 2.37 0.777 0.28 0.8 123.6 122.5 124.8 124.6 124.8 124 mean n.s.ar 6.5 7.1 5.7 5.9 7.7 4.7 s.d. 0.146 1.46 -2.3 0.122 1.58 3.9 0.741 0.33 0.8 146.1 148.4 143.8 143.8 144.5 143 mean s.ar.go 7.1 8.3 5.11 6.3 7.2 5.3 s.d. 0.126 1.54 -1.8 0.483 0.7 1.1 0.164 1.42 2.4 128 127.6 128.4 126.2 126.5 126 mean ar.go.me 5.1 5.1 5.2 4.8 4.3 5.4 s.d. 0.021 2.34 -3.5 0.106 1.6 2.92 0.093 1.72 4 37.4 38.5 36.3 33.9 35.5 32.3 mean sn-mp angle 6.9 6.1 7.6 6.2 4.9 7.03 s.d. 0.77 0.28 -0.3 0.947 0.06 0.1 0.716 0.36 0.5 16.8 18.3 15.4 16.5 18.2 14.9 mean sn-occ angle 4.9 5.1 4.4 4.5 4.2 4.2 s.d. 0.003 3.06 -2.8 0.144 1.49 1.77 0.009 2.7 3.85 20.6 19.8 21.5 17.8 18.02 17.7 mean occ-mp angle 4.04 4.07 3.9 4.1 3.4 4.8 s.d. 0 3.97 -4.6 0.012 2.63 3.9 0.005 2.9 5.4 28.9 29.1 28.8 24.3 25.2 23.4 mean pp-mp angle 5.4 5.6 5.3 5.05 3.4 6.21 s.d. 0.346 0.947 1.4 0.649 0.45 0.85 0.107 1.65 3.55 113.6 115 113 115 114 116 mean pp angle1 5.5 5.5 5.6 7.08 6.1 7 s.d. 0.77 0.29 0.4 0.82 0.22 0.55 0.862 0.17 0.35 92.8 92.3 93.2 93.2 92.9 93.6 mean ī -mp angle 6.6 7.8 5.3 7.1 7.3 7.1 s.d. 0.087 1.73 3.6 0.131 1.54 4.92 0.414 0.82 2.15 124.9 124.1 125.8 128.5 129.07 127.9 mean ii angle 8.6 10.2 6.7 9.5 9.9 9.4 s.d. 0.049 1.99 -5.27 0.168 1.4 3.75 0.117 1.6 7.8 397.9 398.7 397.2 392.7 395 389.4 mean sum s.a.g 7.2 6.7 7.7 15.07 15.5 20.3 s.d. j bagh college dentistry vol. 29(2), june 2017 fracture resistance restorative dentistry 26 fracture resistance of endodontically treated premolar teeth with extensive mod cavities restored with different bulk fill composite restorations (an in vitro study) bilal h. ibrahim, b.d.s., d.d.s. )1( haitham j. al-azzawi, b.d.s., msc. )2( abstract background: the present in-vitro study was undertaken to evaluate and compare fracture resistance of weakened endodontically treated premolars with class ii mod cavities restored with different bulk fill composite restorations (everx posterior, alert, tetric evoceram bulk fill, and sdr). the type and mode of fracture were also assessed for all the experimental groups. materials and method: forty-eight human adult maxillary premolar teeth were selected for this study. standardized extensive class ii mod cavities with endodontic treatment were prepared for all teeth, except those that were saved as intact control. the teeth were divided into six groups of eight teeth each (n=8): (group 1) intact control group, (group 2) unrestored teeth with endodontic treatment, (group 3) restored with (tetricevoceram bulk fill), (group 4) restored with sdr bulk-fill flowable composite, (group 5) restored with everx posterior composite and (group 6) restored with alert composite. . all specimens were subjected to compressive axial loading until fracture in a universal testing machine. the data were statistically analyzed using one-way anova test and lsd test. macroscopic fracture type were observed and classified into favorable and unfavorable. specimens in groups 3, 4, 5 and 6 were examined by stereomicroscope at a magnification of 20× to evaluate the mode of failure into adhesive, cohesive or mixed. results: the mean fracture load was (1.2505kn) for group 1, (0.371kn) for group 2, (0.512 kn) for group 3, (0.6435 kn) for group 4, (0.608 kn) for group 5, and (0.8315) for group 6. using one way anova test a highly significant difference (p < 0.01) were found among all groups. the use of alert composite (which contain micro glass fiber) improved the fracture resistance significantly in comparison to other groups. sdr bulk-fill flowable composite showed better improvement in fracture resistance but with no significant differences in comparison to everx composite restoration (which contain short e-glass fiber filler). the type of failure was unfavorable for all the restored groups. conclusion: all experimental composite restorations showed significant improvement in the resistance to cuspal fracture in comparison to unrestored one (group 2). however, under the conditions of this study, direct composite restorations should be considered as a valid interim restoration for weakened endodontically treated teeth before cuspal coverage can be provided. key words: fracture resistance, fiber reinforced composite, bulk fill. . (j bagh coll dentistry 2017; 29(2):26-32) introduction the restoration of endodontically treated teeth is one of the topics more studied and controversial in dentistry. questions and contradictory opinions remain about clinical procedures and materials to be used to restore these teeth, once fractures are often related (1). however, the longevity of the tooth is often dictated by the coronal restoration and its ability to prevent leakage and resist fracture. the inherent elastic properties of intact enamel and dentine are altered when even just an occlusal cavity is prepared without endodontic access, creating a reduction in fracture resistance (2). with the removal of both marginal ridges in a mesial-occlusal-distal (mod) cavity preparation and in conjunction with an endodontic access cavity, a dramatic increase in cuspal deflection is observed (3). (1) master student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. with the removal of both marginal ridges in a mesial-occlusal-distal (mod) cavity preparation and in conjunction with an endodontic access cavity, a dramatic increase in cuspal deflection is observed (3). tooth fracture resistance seems to be only partially recovered when mod preparations are associated with an endodontic access and restored with composite resin (4). adhesive dentistry has considerable advantages in the treatment of weakened tooth structure (5). the choice of materials selected for intracoronal restoration of endodontically treated teeth plays an important role in tooth longevity. in an attempt to reduce some of the time and effort needed for layering and adaptation when placing posterior composites, new materials have been introduced and termed "bulk fill" materials (6). recently, short fiber reinforced composite (ever x posterior) had a fiber length in millimeter scale (1–2 mm), was introduced as a restorative composite resin (7). the composite resin is intended j bagh college dentistry vol. 29(2), june 2017 fracture resistance restorative dentistry 27 to be used as base filling material in high stress bearing areas especially in large cavities of vital and non-vital posterior teeth. further, alert (jeneric/pentron, usa) had fiber length in micrometer scale (20–60 µm). reinforcing effect of the fiber fillers is based on stress transfer from polymer matrix to fibers but also behavior of individual fiber as a crack stopper (8). previous study of garoushi et al. showed how short fiber fillers could stop the crack propagation and provided increase in fracture resistance of composite resin (8). alert showed high values of echanical parameters, which seems to be a result of high filler load level. the most important and extensively investigated variable for physical performance in dental composite resins is filler loading (9). in addition, sdr restorative material designed to be used as a base in class i and class ii restorations. it has handling characteristics typical of flowable composite, but can be placed in 4 mm increments with minimal polymerization stress. it is designed to be overlaid with methacrylate based universal posterior composite replacing missing occluso-facial enamel (10). on the other hand, tetric evoceram® bulk fill material is another bulk fill material which can also be placed in increments of up to 4 mm and can achieve high marginal adaptation to the floor and walls of cavity preparation, eliminating the need for a flowable liner as reported by the manufacturer. the patented shrinkage stress reliever technology increases marginal integrity and decreases polymerization shrinkage, with a resultant decrease in the probability of tooth deformation, post-operative sensitivity, microleakage, and secondary caries (11). so this study was conducted to evaluate the ability of these bulk fill restorative composite materials to restore the strength of weakened endodontically treated premolars. materials and methods teeth selection forty eight sound upper first premolar teeth with two roots extracted for orthodontic purposes with age range from 18-22 years, collected from different health centers in baghdad city, were used in this study. teeth were stored in 0.1 vol% thymol solution for 48 h (12). then in distilled water at room temperature (13). teeth of comparable size and shape were selected by crown dimensions after measuring the bucco-lingual and mesio-distal widths in millimeters (14). teeth mounting each tooth was embedded in a block of selfcured acrylic resin (vertex, switzerland) in plastic cylinders (2.5cm×2.5cm). the teeth were embedded along their long axes using a surveyor. the acrylic covered the roots to within 2 mm of the cej, to approximate the support of alveolar bone in a healthy tooth (15). some authors stated that fracture load was unaffected by either thermal cycling or the presence of a simulated periodontal ligament (15) and therefore neither was included in this study. sample grouping the teeth were randomly divided into six groups (8 teeth in each group) according to the type of the restorative material that was used. group 1: sound control group. group 2: a class ii mesio-occluso-distal (mod) cavity was prepared with extensive endodontic access cavity involving the removal of the axial dentin. endodontic treatment was completed and the mod cavity left unrestored. group 3: a class ii mod cavity and endodontic treatment were prepared as in group 2 and restored with tetric evoceram bulkfill. group 4: a class ii mod cavity and endodontic treatment were prepared as in group 2 and restored with resin based composite (everx) (gc) up to 2 mm below the cavity margin and covered with gc posterior composite. group 5: a class ii mod cavity and endodontic treatment were prepared as in group 2 and restored with sdr (dentsply) as a flowable base up to 2 mm below the cavity margin and covered with gc posterior composite. group 6: a class ii mod cavity and endodontic treatment were prepared as in group 2 and restored with alert condensable composite (pentron) cavity preparation: all of the teeth, except for group 1 which served as intact control, received mod cavity preparation by the aid of a modified dental surveyor with no proximal steps and flat floor (16).the dimensions of the cavity preparations were such that remaining tooth structure was weakened. the bucco-lingual width of the occlusal isthmus and the proximal boxes was one half of the intercuspal width. cavity floor was prepared (1 j bagh college dentistry vol. 29(2), june 2017 fracture resistance restorative dentistry 28 mm) coronal to the cej and the total depth of the cavity was (5-6 mm) measured from the cavosurface margin of the palatal cusp. the cavo-surface margins were prepared at 90º with rounded internal line angles. consistency in cavity preparation was ensured by parallel preparation of the facial and palatal walls of the cavity (15). the depth was measured by graduated periodontal probe and the dimensions were checked using dental vernier from different points of the prepared cavity (17). endodontic treatment endodontic access cavity was prepared by the aid of dental surveyor, any access cavity wider than the width of the cavity (1/2 the intercuspal distance) was discarded and not included in the study. the teeth were held in moist gauze to prevent dehydration (18). root canals were instrumented initially using stainless steel k-files #10 and 15, followed by rotary ni-ti instruments (waveone, dentsply maillefer) using crown-down technique. according to the manufacturer instructions, and in most cases, the technique only requires one hand file followed by one single waveone file to shape the canal completely until it achieved the working length. for standardization purposes, all canals were instrumented up to size primary (19).after that the canals were filled by matching size waveone gutta-percha points using a resin based sealer (ah plus, dentsplymaillefer). a resin based sealer was used rather than eugenolbased sealer to avoid the detrimental effect of eugenol-based sealers on polymerization of dental composites (20). then, chemical cured glassionomer restorative material (riva self -cure, sdi, austria) was used to seal the access cavity up to the level of the pulpal floor (21). mechanical testing all specimens were subjected to compressive axial loading until fracture in a computer controlled universal testing machine (laryee, china). the crosshead speed was 0.5 mm/minute. a steel bar (8 mm in diameter) was placed at the center of the occlusal surface and the tooth with its acrylic block was fixed to the base of the testing machine whose position was adjusted in such a position that the bar was applied in parallel to the long axis of the tooth and to the slopes of the cusps (rather than the restoration) (12). all samples were loaded until fracture while maximum breaking loads were recorded in kilo newton (kn) by a computer connected to the loading machine. assessment of fracture type and mode macroscopic fracture patterns were observed after ink perfusion of each sample for 5 min to stain the exposed dentin and highlight fracture lines. photographs were taken using a digital camera to determine type of fracture (22). further the type of failure was also determined and categorized as favorable and unfavorable fractures. unfavorable fracture was denoted if the fracture line was below the cej extending to the radicular portion. on the other hand, favorable fracture was denoted if the fracture line above the cej (19). the mode of failure was assessed into adhesive mode in which the failure occur at tooth\restoration interface, cohesive mode in which the failure occur within the restoration and mixed mode of failure in which the failure was both adhesive and cohesive. the mode of failure was evaluated under a stereomicroscope at a magnification of 20× (15). results fracture resistance values of all experimental groups the mean values, standard deviation (sd) and the percentage of increase and decrease in strength are presented for each group in (table1). table 1: mean values, standard deviation (sd) and percentage of reduction and increase in strength for each group group mean (kn) sd percentage of reduction in strength percentage of increase in strength group 1 1.25 0.16 100% group 2 0.37 0.07 70.33% group 3 0.51 0.09 59.00% 41.00% group 4 0.64 0.10 48.54% 51.46% group 5 0.61 0.11 51.38% 48.62% group 6 0.83 0.11 33.5% 66.50% in this study, intact sound teeth (group 1) presented the highest mean value (1.2505 kn), whereas prepared unrestored teeth with endodontic treatment (group 2) showed the least fracture strength (0.371 kn). among the restored teeth groups, those restored with alert (group 6) showed the highest mean j bagh college dentistry vol. 29(2), june 2017 fracture resistance restorative dentistry 29 value (0.8315kn), while teeth restored with tertic evoceram® bulk fill composite (group 3) presented the lowest mean value (0.512 kn). on the other hand, the fracture strength of teeth restored with sdr (group 4) and everx (group5) was (0.6435kn) and (0.608kn) respectively. anova test revealed that there was a statistically highly significant difference among all groups (p < 0.01), (table 2). table 2: anova test of fracture resistance mean values for all groups. sum of squares df mean square f sig. between groups 3800329.75 5 760065.95 59.078 .000 (hs) within groups 540353.50 42 12865.56 total 4340683.25 47 the results of lsd test showed the significance between groups (table 3). table 3: lsd test variables mean difference sig. +ve control unrestored 878.75 .000 (hs) ivoclar 738.50 .000 (hs) sdr 607.00 .000 (hs) everx 642.50 .000 (hs) alert 419.00 .000 (hs) unrestored ivoclar -140.25 .018 (s) sdr -271.75 .000 (hs) everx -236.25 .000 (hs) alert -459.75 .000 (hs) ivoclar sdr -131.50 .025 (s) everx -96.00 .098 (ns) alert -319.50 .000 (hs) sdr everx 35.50 .535 (ns) alert -188.00 .002 (hs) everx alert -223.50 .000 (hs) fracture type from table (4), the results of this study showed that intact sound teeth (group 1) had 7 samples (87.5%) with favorable fracture type and 1 sample (12.5%) with unfavorable type. whereas other groups like group 2, group 3 and group 6 had 7 samples (87.5%) presented unfavorable fracture type and 1 sample (12.5%) with favorable fracture. in (group 5) there was 5 samples (62.5%) with unfavorable fracture and 3 samples (37.5%) with favorable fracture. in addition, the type of fracture of (group 4) was 4 samples (50%) with favorable fracture type and the other 4 samples had unfavorable fracture type. table 4: type of fracture in the study groups group fracture type unfavorable favorable group 1 (sound) 1 (12.5%) 7 (87.5%) group 2 (unrestored) 8 (100%) 0 (0%) group 3 (ivoclar) 7 (87.5%) 1 (12.5%) group 4 (sdr) 4 (50%) 4 (50%) group 5 (everx) 5 (62.5%) 3 (37.5%) group 6 (alert) 7 (87.5%) 1 (12.5%) total 31 17 fracture mode as presented in table (5), teeth restored with tetric evoceram (group 3) exhibited 7 samples (87.5%) with adhesive mode of failure and only one (12.5%) with mixed failure, and those with sdr (group 4) show 4 samples (50%) with cohesive mode of failure and 4 samples (50%) with adhesive mode of failure. however, those restored with everx (group 5) presented 3 sample (37.5%) with cohesive failure, 4 samples (50%) with adhesive type of failure and 1 sample (12.5%) with mixed type of failure, and those restored with alert (group6) exhibit 6 samples (75%) with adhesive mode of failure, and 2 samples (25%) with mixed mode of failure. table 5: fracture mode of the restored samples group fracture mode total cohesive adhesive mixed group 3 1 (12.5%) 1 (12.5%) 6 (75%) 8 group 4 1 (12.5%) 6 (75%) 1 (12.5%) 8 group 5 2 (25%) 5 (62.5%) 1(12.5%) 8 group 6 6 (75%) 2 (25%) 8 discussion despite its limitations, fracture testing remains a common experimental method of evaluating restorative procedures for root filled teeth. fracture resistance, as it pertains to dental materials, has been defined as the “highest load a sample can withstand.” fracture resistance of intact teeth (group 1) the highest fracture resistance mean value presented by the intact teeth (group 1) could be attributed to the presence of intact palatal and buccal cusps with intact mesial and distal marginal ridges which form a continuous circle of dental j bagh college dentistry vol. 29(2), june 2017 fracture resistance restorative dentistry 30 structure, reinforcing the tooth and maintaining its integrity (4). this is in agreement with shivanna and gopeshetti (23). furthermore, there was a statistically high significant difference with other experimental groups (table 3). fracture resistance of prepared unrestored teeth (group 2) in this study, the lowest fracture resistance mean value presented by the prepared unrestored teeth (group 2) which was statistically highly significant when compared with all other groups could be attributed to the type and quality of the remaining tooth structure after mod cavity preparation, as teeth with large mod cavities are severely weakened due to the loss of the reinforcing tooth structures, specially the cusps andmarginal ridges, so become more susceptible to fracture. fracture resistance of the restored groups in this study, it is clearly seen that all composite resin restored teeth displayed improved fracture strength than the prepared but unrestored teeth group with endodontic treatment (group 2) which presented mean value. the statistically highly significant differences in fracture resistance between the unrestored and restored groups could be due to the micromechanical bonding between the adhesive system and the tooth structure and hybrid layer formation, which tend to bind the walls of the cusps together and strengthen the remaining tooth structure, and distribute the forces more evenly among the various interfaces in composite restorative material, that have been bonded to enamel and dentin by adhesive bonding agent. this reduction in localized forces offers greater opportunity for reinforcing the tooth structure and increases the fracture resistance of the cusps (24). on the other hand, the increase in the fracture resistance of restored teeth could be attributed to that all composite materials used in this study are considered low-shrink materials, and it had been shown that the use of low shrinkage composite materials increased the fracture resistance of teeth. this finding comes in agreement with hamouda and shehata who concluded that the use of low shrinkage composites significantly strengthened maxillary premolars with mod preparations under compression loadings (17). comparisons among different bulk fill materials (groups 3, 4, 5 and 6) among the groups restored with the bulk fill materials, the group restored with alert (group 6) showed the highest fracture resistance mean value and highest percentage of increase in fracture resistance with statistically highly significant difference as compared with groups restored with sdr (group 4), everx (group 5), and tertic evoceram® bulk fill composite (group 3) respectively. this result could be attributed to the following reasons: 1. better mechanical properties of alert composite as compared with the other bulk fill materials (sdr and tetricevoceram® bulk fill) including higher flexural strength, higher fracture toughness and higher flexural modulus. this is in accordance with the results of garoushi et al. (25). 2. alert is a fiber-reinforced composite withfiber length in micrometer scale (20–60 µm) whichmayexplained the difference in fracture toughness values amongthe other materials (sdr and tetric evoceram® bulkfill). reinforcing effect of the fiber fillers isbased on stress transfer from polymer matrix to fibers but alsobehavior of individual fiber as a crack stopper (8). 3. alert showed high values of mechanical parameters, which seems to be a result of high filler load level (conventional and microglass fiber 84 wt%, 62 vol. %). the most important and extensively investigated variable for physical performance in dental composite resins is filler loading (9).previous studies found a positive correlation between filler loading and mechanical performance (26). 4. alert has low polymerization shrinkage (27). it is claimed by some authors that the polymerization shrinkage of composite resins plays an important role on the debonding of the adhesive interface (28) this is consequently maydecrease the fracture resistance. in this study, the new short fiber reinforced composite (everx) (group 5) showed fracture resistance (0.608 kn) which is lower than that of alert (0.831 kn) with high significant difference. everx contains short e-glass fiber fillers with length ranging from 0.6 to1.5mm (main 0.8 mm), resulting in random orientation of the short fibers within the composite restorations. random fiber orientation and lowered cross-linking density of j bagh college dentistry vol. 29(2), june 2017 fracture resistance restorative dentistry 31 the polymer matrix by the semi-ipn structure likely had a significant role in mechanical properties (29). in spite of its high mechanical properties, it give lower values of fracture resistance than groups 4 and 6, this may be due to: 1. the length of fibers in millimeter scale does not provide good adhesion to hybrid layer than that provided by micro glass fibers that present in alert. 2. alert, had a higher flexural modulus value than everx, as found by garoushi although there was non-significant difference between them (25). 3. some authors have shown low values of fracture toughness of a fiber containing dental composite (30). 4. in a study of different bulkfil composites, the degree of conversion was measured by raman spectroscopy, the materials sdr, everx and tetric evoceram bulkfil was 67.6%, 61.6%, and 56.7% respectively (31). in (group 4), teeth were restored with flowable, bulk-fill base (sdr). the findings of this study revealed that the mean fracture load for this group was (0.6435 kn) which is higher than the restored groups 3 and 4 with no significant difference in comparison to group 4 (everx). these findings may due to the elastic buffer effect of using a low-viscosity flowable composite. it was determined that polymerization shrinkage and the concomitant stresses upon the restorationtooth interface have an influence upon the final outcome of extensive composite resin restorations. these findings come in agreement with cara et al; atiyah and baban (32,33). moreover lohbauer et al., postulated that high flexural modulus has been identified to inhibit the ability of a material to resist deformation due to loading and the accumulation of surface and bulk defects resulting in premature failure (34). also, considering bulk fill placement technique, it has been found that sdr has good internal adaptation in high c-factor cavities (35). composite tetric evoceram bulk fill, containing filler load of 60% by volume demonstrated the significantly lower fracture toughness and flexural strength values. in other words, this study demonstrated the absence of a direct relationship between volumetric content of inorganic particles and fracture resistance parameters (fracture toughness and flexural strength) (36). moreover, the combination of lower compressive strength, lower flexural strength, lower flexural modulus and lower fracture toughness of tetric evoceram® bulk fill composite as found by tiba et al. (37) could be attributing factors for the lower fracture resistance and lower percentage of increase in fracture resistance of teeth restored with tetric evoceram® bulk fill composite as compared with alert™ composite and others (sdr and everx). within limitations of this experimental study, the following conclusions could be drawn: 1sound nonrestored teeth present significantly higher fracture resistance compared with other groups (restored and unrestored) in this study. 2teeth restored with alert that contain filler (conventional and micro glass fiber), showed the highest fracture resistance among all restored groups with statistically high significant difference. 3direct composite restorations should be considered as a valid interim restoration for endodontically treated teeth before cuspal coverage. references 1. lapria fac, rodrigues rcs, de almeida antunes rp, et al. endodontically treated teeth: characteristics and considerations to restore them. j prosthodont res 2011; 55(2): 69-74. 2. younong w, cathro p, marino v. fracture resistance and pattern of the upper premolars with obturated canals and restored endodontic occlusal access cavities. j biomedical res 2010; 24(6): 474-8. 3. gonzález-lópez s, deharo-gasquet f, vílchezdíazma, ceballoa l, bravo m. effect of restorative proceduresand occlusal loading on cuspal deflection. oper dent 2006; 31: 33-8. 4. soares pv, santos-filho pcf, queiroz ec, et al. fractureresistance and stress distribution in endodontically treated maxillary premolars restored with composite resin. j prosthodont 2008; 17: 114-9. 5. furukawa k, inai n, tagami j. the effects of luting resin bond to dentin on the strength of dentin supported by indirect resin composite. dent mater 2002; 18: 13642. 6. jackson r. efficient core build-up for endodontic teeth using a sonic activated composite resin. dent today 2013.http://www.dentistry today.com/restorative/7193efficientcore-buildups-sonic-activated-compositeresin in-endodontically-treated-teeth. 7. garoushi s, tanner j, vallittu pk, lassila lvj. preliminary clinical evaluation of short fiber-reinforced composite resin in posterior teeth: 12-months report. the open dentistry journal 2012; 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24(2): 81-9. 20. peters o, gohring tn, lutz f. effect of eugenolcontainig sealers on marginal adaptation of dentin bonded resin fillings. inter endod j 2000; 33: 53-9. 21. jack rm, goodell gg. in vitro comparison of coronal microleakage between resilon alone and gutta-percha with a glass-ionomer intra-orifice barrier using a fluid filtration model. j endod 2008; 34(6): 718–20. 22. salameh z, sorrentino r, papacchini f, hounsi hf, tashkandi e, goracci c, ferrari m. fracture resistance and failure patterns of endodontically treated mandibular molars restored using resin composite with or without translucent glass fiber posts. j endod 2006; 32(8):752-55. 23. shivanna v, gopeshetti pb. fracture resistance of endodontically treated teeth restored with composite resin reinforced with polyethylene fibers. endodontol 2013; 24(1): 73-9. 24. franca fg, worschech cc, paulillo am, martins lr, lovadino jr. fracture resistance of premolar teeth restored with different filling techniques. j contemp dent pract 2005; 3(6): 85-92. 25. sufyan g, säilynoja e, vallittu pk, lassila l. physical properties and depth of cure of a new short fiber reinforced composite. dental mater 2013; 29(8): 83541. 26. kim kh, ong jl, okuno o. the effect of filler loading and morphology on the mechanical properties of contemporary composites. j prosthet dent 2002; 87(6): 642-9. 27. herrero aa, yaman p, dennison jb. polymerization shrinkage and depth of cure of packable composites. quintessence international (berlin, germany: 1985) 36.1 (2005): 25-31. 28. meiers jc, kazemi r, meier cd. microleakage of packable composite resins. oper dent 2001; 26: 121-6. 29. garoushi sk, hatem m, lassila lvj, vallittu pk. the effect of short fiber composite base on microleakage and load-bearing capacity of posterior restorations." acta biomater odontol scand 2015: 1-7. 30. drummond jl, lin l, miescke kj. evaluation of fracture toughness of a fiber containing dental composite after flexural fatigue. dental materials 2004; 20: 591–9. 31. leprince jg, palin wm, vanacker j, sabbagh j, devaux j, leloup g. physico-mechanical characteristics of commercially available bulk-fill composites. j dent 2014; 42(8): 993-1000. 32. cara rr, fleming gj, palin wm, walmsley ad, burke fj. cuspal deflection and microleakage in premolar teeth restored with resin-based composites with and without an intermediary flowable layer. j dent 2007; 35: 482–9. 33. atiyah ah, baban lm. fracture resistance of endodontically treated premolars with extensive mod cavities restored with different composite restorations (an in vitro study). j bagh coll dentistry 2014; 26(1): 7-15. 34. lohbauer u, frankenberger r, kramer n, petschelt a. strength and fatigue performance versus filler fraction of different type of direct dental restoratives. j biomed mater res part b: appl biomater 2006; 76: 114–20. 35. van ende a, de munck j, van landuyt kl, poitevin a, peumans m, vanmeerbeek b. bulk-filling of high c-factor posterior cavities: effect on adhesion to cavity-bottom dentin. dent mater 2013; 29: 269–277. 36. fahad f, majeed ma. fracture resistance of weakened premolars restored with sonically-activated composite, bulk-filled and incrementally-filled composites (a comparative in vitro study). j bagh coll dentistry 2014; 26(4): 22-7. 37. tiba a, zeller gg, estrich c, hong a. a laboratory evaluation of bulk fills versus traditional multiincrement-fill resin-based composites. am dent assoc profess 2013; 3(8): 14-25. j bagh college dentistry vol. 26(1), march 2014 estimation of oral and maxillofacial surgery and periodontics 138 estimation of soluble cd14 level in saliva of patients with different periodontal conditions and its correlation with periodontal health status sarah e.h. al-karawi, b.d.s. (1) maha sh. al-rubaie, b.d.s., m.sc. (2) abstract background: cluster of differentiation 14 (cd14) is a serum/cell surface glycoprotein; and it is a pattern recognition receptor. cd14 expressed on the surface of various cells, or it found soluble in saliva and other body fluids. it has been proposed that soluble cd14 (scd14) may play a protective role by controlling gram negative bacterial infections through its capacity to bind lipopolysaccharide. this study was conducted to assess the level of soluble cd14 in saliva of patients with different periodontal diseases and healthy subjects and determine its correlation with clinical periodontal parameters. materials & methods: a total of 80 subjects, age ranged (25-50) years old, divided into three main groups, group ι consisted of 45 chronic periodontitis patients, group ιι consisted of 20 gingivitis patients, lastly group ιιι comprised 15 apparentlyhealthy volunteers. unstimulated whole saliva samples were collected to determine levels of soluble cd14 in saliva by enzyme-linked immune–sorbent assay (elisa). clinical periodontal parameters were recorded at four sites per tooth including plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level. results: a highly significant difference (p<0.01) was found for salivary scd14 levels among the three groups, also it was greater in chronic periodontitis group than those detected for gingivitis and healthy controls with a highly significant difference (p<0.01). furthermore, spearman’s correlation analysis showed statistically highly significant strong correlations (p < 0.05) between salivary scd14 levels and each of (probing pocket depth, clinical attachment level). and non-significant correlation between salivary scd14 level with plaque, gingival & bleeding on probing indices. conclusion: the findings of the present study reemphasize the importance of whole saliva as sampling method in terms of immunological purposes in periodontal disease and suggest that the elevated scd14 concentration may be one of the host-response components associated with the clinical manifestations of periodontal disease. key words: soluble cd14, periodontal diseases, saliva. (j bagh coll dentistry 2014; 26(1):138-143). الخالصة الحادية هي بروتين سكري يوجد في مصل الدم او على سطح الخاليا. وهو احد مستقبالت نمط التعرف. يتواجد على سطح مختلف الخاليا, منها الخاليا ا 14كتلة التمايز الخلفية: ريما يلعب دور وقائياً عبر scd14 ب في اللعاب او سوائل الجسم االخرى. وقد اقُترح انالدموية, خاليا البلعمة النسيجية, الخاليا العدلة وكذلك الخاليا الليفية اللثوية. او يوجد ذائ الذائبة في cd14 مستوى تركيز مستقبالتالسيطرة على االتهابات البكتيرية السالبة من خالل قدرته على االرتباط مع السكريات المتعددة البروتينات. ان المعلومات المتوفرة عن رضى النساغ المزمن ومرضى التهاب ند مرضى النساغ المزمن قليلة جدا, لذا اعدت هذه الدراسة لتكون االولى في العراق الكتشاف مستوى هذه المستقبالت الذائبة في لعاب ماللعاب ع .اللثة وكذلك تحديد ارتباط هذه المستقبالت مع مؤشرات ما حول االسنان السريرية مريض لديهم مرض النساغ المزمن,اما المجموعة 45تتالف من 1مجاميع , المجموعة 3( سنة , موزعون على 50 – 25شخص تتراوح اعمارهم بين ) 00اجمالي المواد والطرق: تقبالت وتحليلها بواسطة نظام شخص. وقد تم اخذ عينات اللعاب لتحديد مستوى المس 15مريض بالتهاب اللثة . واخيرا مجموعة المتطوعين االصحاء وعددهم 20الثانية فتتالف من لثة, مؤشر النزف عند التسبير, عمق جيوب االياليزا)مقايسة االنزيم الممتز المناعي( وكذلك قياس مؤشرات ما حول االسنان السريرية مثل مؤشر الصفيحة الجرثومية, مؤشر التهاب ال .اللثة وفقدان االنسجة الرابطة سريرياً عالوة على ذلك، الذائبة في اللعاب cd14أن هناك فرق معنوي بين مرضى النساغ المزمن ومرضى التهاب اللثة واالصحاء بالنسبة الى مستوى الـ اظهرت هذه الدراسة النتائج: .(p <0.01) طة سريرياً الذائبة في اللعاب وسبر عمق جيب اللثة وفقدان االنسجة الراب cd14 أظهر تحليل االرتباط سبيرمان وجود ارتباط بين البيانات من مستويات تهاب اللثة وتشير إلى أن ارتفاع إن نتائج هذه الدراسة تؤكد مجدداً على أهمية اللعاب و طريقة أخذ العينات من اجل أالغراض المناعية في مرضى النساغ المزمن ومرضى ال االستنتاج: جابة المضيف المرتبطة للمظاهر السريرية لمرضى النساغ المزمن ومرضى اللثة.الذائبة في اللعاب قد تكون واحدة من مكونات است cd14 تركيز مستقبالت introduction periodontal diseases are complex bacteriainduced infections characterized by an inflammatory host response to plaque microbiota and their by-products. most of these microorganisms have virulence factors capable of causing massive tissue destruction both directly, or indirectly. in response to the aggression, host defense mechanisms activate innate and adaptive immune responses (1). (1) m.sc. student. department of periodontics. college of dentistry. university of baghdad. (2)assistant professor. department of periodontics. college of dentistry. university of baghdad. periodontal disease is initiated and maintained in the first line by not only gram negative (-ve) but also gram positive (-ve) bacterial infection of the gingival sulcus (2). recognition of gram -ve bacteria involves membrane-associated positive (-ve) bacterial infection of the gingival sulcus (2). recognition of gram -ve bacteria involves membrane-associated lipopolysaccharide (lps) activation of a series of proinflammatory cytokines and inflammatory mediators from various host cells through a key pathway of cell stimulation: lps/ lipopolysaccharide binding protein (lbp)/ cluster of differentiation 14 (cd14) (3). host recognition pathways for both gram -ve and +ve bacteria comprise pattern recognition (2, 4). j bagh college dentistry vol. 26(1), march 2014 estimation of oral and maxillofacial surgery and periodontics 139 cluster of differentiation 14 (cd14) is a serum/cell surface glycoprotein; is considered to be an important receptor for initial bacterial recognition (5, 7). it is predominantly expressed on the surface of various cells, including peripheral blood monocytes, tissue macrophages (8), neutrophils, and chondrocytes (9), as well as gingival fibroblasts (10). cd14 can be found in two forms, a membrane-bound (mcd14) protein (5, 11) and a circulating soluble (scd14) form found in saliva, gcf and other body fluids (11, 12). while limited information is available on the exact contribution of scd14 to, and its mechanism of action in the pathogenesis of periodontal disease, it can be speculated that scd14 plays a significant role because it is detected in elevated amounts in the gcf of patients with periodontitis (13). it has been proposed that scd14 may also play a protective role by controlling gram -ve bacterial infections through its capacity to bind lps (14). then concentrate lps on the host cell surface for further recognition by the innate host response system (15, 16). the signal transduction of the lps/lbp/cd14 ternary complex on effectors cells is then transferred via the toll-like receptor 4 (tlr4)/md-2 complex (17, 18). upon stimulation, the tlr4/md-2 complex leads to expression of inflammatory mediators, (19) i.e. tumor necrosis factor-α (tnf-α), (il-1 β), il-6, and (ifn-γ) (20). besides its function in lps/cell-wall products signaling, scd14 might play a role in inflammatory diseases by controlling the immune system level of response (21). it has been demonstrated that scd14 is a regulatory factor capable of modulating cellular and humoral immune responses by interacting directly (without lps) with t and b cells, decreasing antigen and mitogen-induced proliferation (22, 23). currently, there are no information on scd14 levels in saliva and their associations with different periodontal conditions in iraq. therefore it was decided to conduct this study. materials and methods sample population included eighty (80) subjects of both females and males aged from (2550) years old. sample recruited for this study were patients attended to the department of periodontics in the teaching hospital of college of dentistry, university of baghdad seeking periodontal treatment. all subjects enrolled voluntarily in the study after a well explanation about the aim and purposes of the study and gave informed consent to participate in the study in the period (november, 2012march, 2013). from each subject, (5ml) of unstimulated whole saliva was harvested; removed particulates by cold centrifugation. the laboratory test was done in the teaching laboratories of baghdad medical city. exclusion criteria included the presence of less than 20 natural teeth, pregnancy and menopause ladies, smoker, patients received periodontal treatment and /or regular used of antiinflammatory medication, antibiotics or the use of other medications known to affect the periodontium in the past 3 months. in a cross sectional study, the subjects generally were divided into three main groups: group i: composed of forty five (45) patients had chronic periodontitis, with probing pocket depth of 4 mm or more, according to who recommendation, with positive bleeding on probing. group ii: consisted of twenty (20) patients had gingivitis. group iii: consisted of fifteen (15) healthy volunteers with clinically healthy periodontium. the control group subjects were patients seeking treatment at other departments in the hospital. the periodontal status was evaluated by measurements of the following clinical periodontal parameters (pli, gi, bop, ppd, and cal). measurements were performed at four sites per tooth for whole mouth excluding the 3rd molar. the readings of ppd were divided into 3 scores which are: score (0): includes the examined sites with ppd range of (1-3) mm score (1): includes the examined sites with ppd range of (4-5) mm. score (2): includes the examined sites with ppd of (≥ 6) mm. cal readings were also divided into 3 scores which are: score (1): includes the sites with cal range of (1-2) mm. score (2): includes the sites with cal range of (3-4) mm. score (3): includes the sites with cal (≥ 5) mm. immunological analysis enzyme linked immuno-sorbent assay was used for quantitative determination of scd14 level in saliva. the work was done in the immunology department of teaching laboratories of baghdad medical city. this assay employs the quantitative sandwich enzyme immunoassay technique. antibody specific for scd14 has been pre-coated onto a microplate. standards and samples were pipetted into the wells and any scd14 present was bound by the immobilized antibody. after removing any unbound substances, a biotin-conjugated antibody j bagh college dentistry vol. 26(1), march 2014 estimation of oral and maxillofacial surgery and periodontics 140 specific for scd14 was added to the wells. after washing, avidin conjugated horseradish peroxidase (hrp) is added to the wells. following a wash to remove any unbound avidin-enzyme reagent, a tmb substrate solution was added to the wells and color develops in proportion to the amount of scd14 bound in the initial step. the color development is stopped and the intensity of the color is measured. statistical analysis data are calculated and entered into a computerized data base structure. statistical analysis was done using spss software. mean and sd, t-test, chi square, anova test, mannwhitney test, kruskal-wallis test and spearman correlation coefficient (r) were used. level of significance was 0.05. results table (1) illustrates the mean values of pli, gi and bop of the three study groups, the values were expressed in mean and ±sd for pli and gi and in percentage for non-bleeding and bleeding sites of bop. it was clearly shown that chronic periodontitis group had the higher mean among the study groups (pli 1.3444 ± 0.45214, gi 1.2676 ±0.37601, bop 57.5% of sites had bleeding) followed by gingivitis group with a mean value of (pli 1.0630 ± 0.30422, gi 1.0610± 0.38397, bop 22.5% of sites had bleeding) and lastly the control group showed the minimum mean value of (pli 0.1207 ± 0.08932, gi 0.0873 ± 0.08498, bop only 1.3% of sites had bleeding). the chronic periodontitis group was subdivided into three scores according to ppd and cal. the distribution of the examined chronic periodontitis sites according to different scores of ppd and cal had been illustrated in figure (1 and 2). a significant difference was observed between the gingivitis & chronic periodontitis groups with both pli and gi and a highly significant statistical difference with bop as shown in table (2). regarding the scd14 level, a highly significant difference was observed among the study groups with a (p-value < 0.001). the chronic periodontitis group had the higher median with (10.359) as illustrated in table (3). inter group comparison revealed a statistical significant difference between the control & gingivitis groups & between the gingivitis & chronic periodontitis & a highly significant difference between the control & chronic periodontitis groups (p-value <0.001) as shown in table (4). there was no correlation between salivary scd14 and clinical periodontal parameters with gingivitis and chronic periodontitis groups while a significant positive correlation was found with the control group. regarding the correlation between the ppd, cal parameters and the scd14 level we noticed a positive highly significant correlation as shown in table (5). discussion in the present study a significant statistical difference was observed between the gingivitis & chronic periodontitis groups with pli, gi.and bop. this result was in agreement with the other studies (24, 25). these are explained by the fact that the microbial biofilm is considered the primary and the major etiological factor responsible for initiation of periodontal disease (26). as for bop the finding indicates the effect of plaque accumulation on blood circulation & the actual pathophysiological process that happened more in inflamed tissue. and the severity of bleeding & the ease of its provocation depend on the intensity of the inflammation (27). for the study groups there were no pathological true pockets or clinical attachment loss for the gingivitis & control groups while for the chronic periodontitis group, there were different scores of severities. regarding ppd, it could be due to increase in the bacterial invasion and the amount of plaque that caused destruction of the sulcular & junctional epithelium & surrounding alveolar bone. as for cal, it could be explained by the early concepts assumed that after the initial bacterial attack, periodontal tissue destruction continued to be linked to bacterial action (27). regarding the scd14 level a highly statistical significant result in scd14 level among the study groups. this is in agreement with other studies (13, 28) who evaluated the scd14 levels in gcf by immunoblotting, and with studies (29, 30) whom evaluated the scd14 levels in plasma & serum (it is important to mention that there is no study evaluated scd14 in saliva to compare with). it is thought that scd14 either protects or enhances the host response to microbial lps (28). and further establish scd14 as an acute phase protein in periodontitis, whose level increases with disease severity. many functions have been attributed to acute-phase proteins, including tissue repair, modulation of coagulation, neuroendocrine secretion, bacterial opsonization & clearing, hemopoiesis, metal binding, and, in the case of cd14, fighting infection (21). regarding the clinical-immunological correlation, there was a weak correlation between salivary scd14 and pli, gi and bop parameters. this result may be due to small number of samples and there are no data to compare the results with it. regarding the correlation between j bagh college dentistry vol. 26(1), march 2014 estimation of oral and maxillofacial surgery and periodontics 141 the ppd parameters and the scd14 level we noticed a positive highly significant correlation and positive highly significant strong correlation between the scd14 level and cal. this might be interpreted as more production of scd14 in cases with mild-tomoderate -tosevere periodontal breakdown, which is consistent with the deleterious role of scd14 because of lps potent stimulation of scd14 release (30) and shedding (31) from monocytes/macrophages and activated neutrophils. as shedding implies the release of the ectodomain of a cell-surface molecule that will keep its biological activity (13), once present in the extracellular environment in a soluble and biologically active form, scd14 can interact with cells lacking cell-surface cd14 such as endothelial and epithelial cells (32, 33). thus, scd14 could mediate cell activation induced by endotoxin and whole bacteria, resulting in the production of a potent immune response and proinflammatory mediators (34), and amplifying the inflammatory process (32, 33), which further take part in the tissue destruction and bone resorption observed in periodontitis (35). in addition, more recent evidence suggests that when bacteria propagate in the periodontal pocket, salivary scd14 promotes their invasion and induces production of il-8 by oral epithelial cells to recruit neutrophils and t-cells and activate neutrophils for the initiation and establishment of an innate immune response to the bacteria at the site of infection (36). references 1. martínez ab , corcuera mm, noronha s , mota p, ilundain cb, trapero jc, et al. host defense mechanisms against bacterial aggression in periodontal disease: basic mechanisms. med oral patol oral cir bucal 2009; 1: 14 (12): e680-5. 2. tietze k, dalpke a, morath s, mutters r, heeg k, nonnenmacher c, et al. differences in innate immune responses upon stimulation with gram +ve & gram ve bacteria. j periodont res 2006; 41: 447-54. 3. darveau rp, tanner a, page rc. the microbial challenge in 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(ivsl). 29. nicu ea, laine ml, morre sa, van der velden u, loos bg. soluble cd14 in periodontitis. innate immun 2009; 15: 121–8. 30. hayashi j, masaka t, ishikawa i, et al. increased levels of soluble cd14 in sera of periodontitis patients. infect immun 1999; 67: 417-20. 31. bazil v, strominger jl. shedding as a mechanism of down-modulation of cd14 on stimulated human monocytes. j immunol 1991; 147: 1567-74. 32. frey ea, miller ds, jahr tg, et al. soluble cd14 participates in the response of cells to lps. j exp med 1992; 176: 1665-71. 33. schumann rr, rietschel et. the role of cd14 & lbp in the activation of different cell types by endotoxin. med microbiol immunol 1994; 183: 27997. 34. labeta mo, vidal k, rey nores je et al. innate recognition of bacteria in human milk is mediated by a milk-derived highly expressed pattern recognition receptor, soluble cd14. j exp med 2000; 191: 1807-12. 35. page rc. the role of inflammatory mediators in the pathogenesis of periodontal disease. j periodontal res 1991; 26: 230–42. 36. takayama a, satoh a, ngai t, et al. augmentation of actinobacillus actinomycetemcomitans invasion of human oral epithelial cells & up-regulation of il-8 production by saliva cd14. infect immun 2003; 71: 5598-604. table 1: the mean values of pli, gi & the percentages of sites with bop among the study groups control no. = 15 gingivitis no. = 20 chronic periodontitis no. = 45 pli mean 0.1207 1.0630 1.3444 ± sd 0.08932 0.30422 0.45214 gi mean 0.0873 1.0610 1.2676 ± sd 0.08498 0.38397 0.37601 bop score 0 98.7% 77.5% 42.5% score 1 1.3% 22.5% 57.5% table 2: groups comparison among the study groups of pli, gi & the percentages of sites with bop group comparison t-test p-value sig. pli gingivitis x chronic periodontitis 2.535 0.014 s gi gingivitis x chronic periodontitis 2.031 0.046 s bop gingivitis x chronic periodontitis chi 710.913 0.000 hs table 3: the median of scd14 level among the study groups groups no. median chi df p-value sig. scd14 level control 15 5.428 21.772 2 0.000 hs gingivitis 20 7.069 periodontitis 45 10.359 table 4: inters groups comparison of scd14 level among the study groups inter groups comparison z-value p-value sig. control x gingivitis 2.471 0.013 s control x chronic periodontitis 4.587 0.000 hs gingivitis x chronic periodontitis 1.991 0.046 s table 5: correlation between the periodontal parameters & the scd14 level among the study groups scd14 level pli gi bop ppd cal r p-value r p-value r p-value r p-value r p-value control 0.570 0.027 0.269 0.333 0.380 0.163 gingivitis 0.095 0.692 0.241 0.306 0.383 0.096 ch. pd 0.217 0.153 0.058 0.706 0.287 0.056 0.489 0.001 0.504 0.000 j bagh college dentistry vol. 26(1), march 2014 estimation of oral and maxillofacial surgery and periodontics 143 figure 1: bar chart of percentage distribution of ppd scores among the chronic periodontitis group figure 2: bar chart of percentage distribution of cal scores among the chronic periodontitis group j bagh college dentistry vol. 29(2), june 2017 oral health oral diagnosis 65 oral health status, salivary mmp-8& secretory leukocyte peptidase inhibitor (slpi) among uncontrolled type-i diabetes mellitus in iraqi patients rehab faisal ahmed, b.d.s., m.sc.(1) raja h. al-jubouri, b.d.s., m.sc., ph.d. (2) abstract back ground: diabetes is a metabolic disease characterized by hyperglycemia that results in deficiency or absence of insulin production. the dental caries and gingivitis/periodontitis are widespread chronic diseases in diabetes. the aim of the present study was determined the salivary matrix metalloproteinase (mmp-8), secretory leukocyte peptidase inhibitor (slpi) and oral health status among uncontrolled diabetic group in comparison with healthy control group. materials and methods: the total sample composed of 90 adults aged (18-35) years. divided into 60 uncontrolled diabetic patients (hba1c >7%) and 30 healthy control group. unstimulated saliva was collected from each subject with type-i dm, bmi, duration of diabetes, hba1c%, dmft, gingival index (gi) and periodontal disease index were recorded during clinical visit. level of salivary mmp-8 and slpi was measured by using elisa immunoassay analysis. results: the dmft was highly significant higher among type-i dm group than control group (p<0.001),gi and pocket depthwas significant difference (p=0.002, p<0.001 respectively) between two groups except the attachment loss with no significant difference (p=0.06). the salivary mmp-8 was elevated, whereas slpi was lowered in individuals with type i diabetes mellitus in comparison to the healthy controls, but statistically was non-significant. analysis among uncontrolled diabetic patients revealed that the hba1c% correlate positively significant with salivary mmp-8 (r=0.321, p=0.012), slpi (r=0.276, p=0.033) andattachment loss (r=0.353, p=0.006); however the correlation between mmp-8 & slpiwas a significant in negative direction (r=-0.395, p=0.002). conclusion:the dmft, pocket depth and gingival index was higher in uncontrolled diabetes group. hba1c% was positively correlation withmmp-8, slpi and attachment loss in uncontrolled diabetic group. salivary slpi associated inversely with significant correlation with salivary mmp-8. keywords:diabetes mellitus, salivary mmp-8, slpi, oral health status. (j bagh coll dentistry 2017; 29(2):65-70) introduction diabetes mellitus (dm) is one of the most serious diseases of metabolism and produces a developing medical irregularity, with concomitant morbidity and mortality that involve people of all ages (1). it has been known to affect the salivary function and composition, eventually effecting oral cavity and dental health(2).in the american diabetes association (3), hba1c has been referred to as a1c. it is consider as a good indicator of average glycemic concentrations during the previous 90 to 120 days and it is the standard method for assessing long-term glycemic control. the diagnosis of type 1 diabetes may be occur at any age, at birth the individuals with a genetic susceptibility have normal beta cell mass but start to lose beta cells secondary to autoimmune destruction that occurs over months to years so the main cause of type 1 diabetes is immunemediated nature, and the beta cell loss is a (t cell) mediated autoimmune attack (4). the most consistent finding in poorly controlled diabetic patients is the periodontal disease. (1) ph.d. student, department of oral medicine, college of dentistry, university of baghdad. (2) professor, department of oral medicine, college of dentistry, university of baghdad. approximately 75% of these patients have periodontal disease that characterized by increased alveolar bone resorption and inflammatory gingival changes and the dental caries considers being a major oral health problem affecting children, adolescents, adults as well as elderly people (5,6). according to pucher& stewart (7) the periodontal disease is a group of chronic inflammatory disorder that associated with damage the periodontal attachment apparatus (cementum, collagen fibrils and a layer of calcified inter fibrillar matrix on the root surface of the tooth). the destruction of periodontal tissues starts early in young people with type-i, but it is more evidently expressed in pre-pubertal and pubertal periods, depending on the duration of disease, glycemic control and the presence of gingivitis (8). all mmps have the following characteristics: they degrade proteins of the extracellular matrix (ecm); they require calcium for their stability; they contain zinc in the active site that can have a significant effect in a relevant pathophysiological end point(9); periodontal mmp-8 (collagenase 2) expression is associated with periodontal disease but the information concerning the periodontal j bagh college dentistry vol. 29(2), june 2017 oral health oral diagnosis 66 mmp-8 expression in type-i diabetic patients with periodontal disease is insufficient (10, 11). the secretory leukocyte peptidase inhibitor (slpi) is an 11.7-kd a protein which is naturally present in saliva, suggesting that this protein is likely a major antiviral and antimicrobial component of oral secretions (12).although the level of glycemic control plays a central role with respect to periodontal status, the two chronic diseases (diabetes and periodontal diseases) are considered to be biologically linked, in addition to that the combination of diabetes with other risk modifiers for periodontal diseases such as cigarette smoking or genetic polymorphisms may confer cumulative risks not yet elucidated (13). materials and methods the participants were 90 adult aged 18-35 years of both genders. the patients were examined at the diabetic clinic in baghdad teaching hospital and alkindy teaching hospital (diabetic endocrinology center) in baghdad city during the period from (november2014 to april 2015). unstimulated whole saliva sample were collected for 10 mints by the spitting methodat the same day of blood sample aspiration for hba1c measurements and after informed consent was obtained from all individual. they were all with confirmed diagnosis of insulin dependent diabetes mellitus (iddm) with duration more than 3 years. adult individual with any other systemic diseases, taking any medications like antihypertensive, anti-lipid and aspirin and subjects less than 18 years of age were excluded. the samples were divided into two groups: 60 patients with uncontrolled type 1 diabetes mellitus (hba1c >7%) and non-diabetic subjects as a control group were included 30 healthy subjects who did not suffer from any systemic disease and matching with the study group. the decayed-missing-filled teeth(dmft) index which was introduced according to world health organization criteria(14)to measure the prevalence of dental caries/teeth, gingival index (gi) and periodontal disease index (15, 16) were all recorded for all participants. in the laboratory the salivary samples were centrifuged at (4000 rpm for 10 minutes) to remove any unwanted particles; then the supernatant has been taken by micropipette, aliquot into eppendorf tubes (500µl) and stored at 20°c and -70°c for protein until analysis. the immunoassay analyses of salivary sample were doing to measure the concentration of mmp-8 and slpi by using an enzyme-linked immunosorbent assay(elisa technique) according to the manufacturer’s instructions. the saliva sample was diluted by using phosphate buffer 150 fold; the concentration read from the standard curve must be multiplied by dilution factor. statistical analyses were done using spss version 21 computer software (statistical package for social sciences) in association with excel version 5. the statistical significance of difference in mean between 2 groups was assessed using the independent samples t-test. p value less than 0.05 was considered statistically significant and highly significance when p< 0.01. results the (mean ± sd) age in patients with diabetes was (24.8±5.4) years, while the (mean ± sd) age in healthy controls subjects was (23.8±5). dental caries was significantly higher in diabetic patient than healthy control group (p<0.001). the mean dmft in diabetic individual was (9) in comparison to the control (5.8). in table 1, the median pocket depth and gingival index were significantly lower in healthy control group (0.92, 1.06 respectively) in comparison to the diabetic group (1.48, 1.25 respectively). the difference was significant between two groups, also the median attachment loss was lowest among healthy control group, but the difference was non-significant when compared to the uncontrolled diabetic group (p=0.06). the table 2 showed the average ofsalivary mmp-8& slpi levels (ng/ml) among study groups. the highest salivary mmp-8 value was represented in the saliva of uncontrolled diabetic group, whereas the slpi was lowest, but the difference was failed to reach the significant (p=0.14, p=0.09, respectively). among uncontrolled diabetic type-i the mean dmft was lowest (6.9) among diabetic with youngest age group (<20year) and increase gradually with increasing age to reach its maximum value (11.9) among oldest age group (30+year), also the median pocket depth among diabetic with youngest age groups was lowest (1.3, 1.73 and 1.32 respectively) compared to the oldest age group (2.12).the difference was statistically significant (p=0.007, p=0.044, respectively) as shown in table 3. the mean dmft was highest (9.4) among diabetic with acceptable weight group (<25) and decrease gradually with increasing weight to reach its minimum value (7) among obese group (30+), whereas the attachment loss median was highest in overweight group in comparison to other categories, but statistically no significant differences, on other hand the median pocket depth and gingival index was highest among j bagh college dentistry vol. 29(2), june 2017 oral health oral diagnosis 67 diabetic with overweight (1.88 &1.37 respectively) and acceptable weight (1.44 & 1.25 respectively) in comparison to the obese group (0.93 & 1 respectively). this difference was statistically significant as shown in table 3 (p=0.03, p=0.041, respectively) as shown in table 3. the correlation of hba1c with salivary mmp-8, attachment loss and slpi were significant in positive direction among uncontrolled diabetic type-i group (r=0.321,p=0.012; r=0.353, p=0.006;r=0.276, p=0.033; respectively) as shown in table 4., in contrast the correlation between salivary mmp-8 and slpi was statistically in negative direction (r=-0.395, p=0.002) (table 5). table 1: clinical parameters (mean/median) and standard deviation among study groups clinical and oral health parameters uncontrolled diabetic (type-i) healthy control statistical analysis mean/median mean/median p-value age (years) 24.8 (±5.4) 23.8 (±5) 0.44[ns]*** bmi 24.3 (± 4.3) 24.4 (±4.4) 0.91[ns] dmft 9 (±4.4) 5.8 (± 2.6) p<0.001* loss of attachment 0.6 0.24 0.06[ns] pocket depth 1.48 0.92 p<0.001* gingival index 1.25 1.06 0.002** *(p<0.01) highly significant, ** (p<0.05) significant, *** (p>0.05) non-significant table 2: salivary mmp-8 and slpi levels (ng/ml)(median/mean) among study groups salivary parameter uncontrolled diabetic (type-i) healthy control statistical analysis median/mean mean rank median/mean mean rank p-value mmp-8 67.1 48.4 41.1 39.7 0.14[ns]* slpi 31.5 36.8 0.09[ns]* * (p>0.05) non-significant table 3: the difference in average (mean/median) of oral health status parameter between age and bmi categories among uncontrolled diabetic type-i clinical parameters uncontrolled diabetic type-i(mean/ median) dmft attachment loss pocket depth gingival index age <20 6.9 0.82 1.3 1.03 20-24 8.4 0.42 1.73 1.27 25-29 9.4 0.36 1.32 1.06 30+ 11.9 1.53 2.12 1.33 p-value 0.007* 0.32[ns]** 0.044* 0.12[ns]** bmi acceptable(<25) 9.4 0.42 1.44 1.25 overweight (25-29.9) 9.1 1.13 1.88 1.37 obese(30+) 7 0.21 0.93 1 p-value 0.23[ns]** 0.24[ns]** 0.03* 0.041* * (p<0.05) significant ** (p>0.05) non-significant table 4: correlation coefficients between hba1c and salivary parameters (mmp-8, slpi) and attachment loss among diabetic type-i group. uncontrolled diabetic type-i glycated hemoglobin salivary mmp-8 attachment loss salivary slpi r p r p r p hba1c% 0.321 0.012 0.353 0.006 0.276 0.033 table 5: correlation coefficients between salivary parameters (mmp-8, slpi) among diabetic type-i group. uncontrolled diabetic type-i salivary mmp-8 salivary slpi r p -0.395 0.002 j bagh college dentistry vol. 29(2), june 2017 oral health oral diagnosis 68 dissusion diabetes mellitus has been linked with an increased risk of oral diseases. saliva has a major role in maintaining the health of oral cavity. the recent consensus of the american diabetes association and the european association for the study of diabetes advocate glycated hemoglobin as the main parameter to assess the metabolic control prior to dental treatment. the present study was carried out to elucidate the effect of hyperglycemia on salivary parameter like mmp-8, slpi and oral health status among uncontrolled diabetes mellitus type-i in baghdad city in iraq, in addition the study groups selected aged 18-35 years, as at these ages the type 1 diabetes mellitus are predominate, the duration of disease at least three years. data of the present study revealed the diabetic patient had significant higher mean dmft than control healthy (p<0.001). the elevation in the severity of dental caries among uncontrolled diabetic group may be related to changes in the salivary secretion that reduce in diabetic patient, this a long with poor oral hygiene, decrease salivary flow rate, susceptibility to infection by microorganism and decrease immune response to inflammation or due to impaired neutrophil chemotaxis result in the development of dental caries (17). this result is in agreement with (18, 19)and dis agreement with other studies, some found lower (20), while otherreported nodifferenceindentalcaries(1). on other hand,eduardo bernabé and aubrey sheiham(21) were found the level of caries increased through to adolescence and become a larger increase in dmft in adulthood, in this study the dmft among uncontrolled diabetic was lowest with youngest age group and increase gradually among oldest age group, significant differences was found between age groups. individual with type 1 diabetes mellitus and poor glycemic control have highest pocket depth median in compared to the healthy controls, in addition there is no differences in attachment loss median between diabetic and healthy controls groups. this may be due to the hyperglycemia that has a negative impact on the antiinflammatory response and increases the oxidative stress of microvascular disorder in periodontal tissues, another explanation about the tissue change (periodontium) among dm due to the advanced glycation end-products (age) synthesized as a result of hyperglycemia, can convert macrophages into cells with a destructive phenotype, producing high levels of interleukin-1b, interleukin-6 and tumor necrosis factor-alpha (tnf-alpha). this age have the ability to increase the permeability of endothelium and express high levels of molecular adhesion receptors that lead to high susceptibility to infections and delayed wound healing in diabetic patients(22). the result is in agreed with other studies(23, 24). in this study there is a significant difference in gi median between study groups, the microflora in the dental plaque that forms daily adjacent to the teeth cause this inflammatory process (25). this result is in agreed with other study (26) who found the subject with poor glycemic control has more sever gingival inflammation by the higher score of gingival index, also the pocket depth and gingival index become high in overweight category and decreased gradually in the obese category. the possible explanation may be related to the circulating secretory leukocyte peptidase inhibitor (slpi) that express in subcutaneous white adipose tissue, in addition to the macrophage, neutrophil and mucous membrane epithelial cell (27). this slpi have antibacterial effect and play a significant role in the host defense by maintain the balance between inflammation and protective response, this result is disagreement with study(28)who found no increase in the circulating slpi in diabetic patients and in agreement with other study(29)who reported the circulating slpi has been correlated with metabolic dysfunction. the highest salivary mmp-8 and lowest slpi values were represented in the saliva of uncontrolled diabetic group, but the difference was failed to reach the significant this may be due to small size of sample. the positive correlation between salivary mmp-8, attachment loss and hba1c% showed that the poor glycemic control patients (hba1c >10%) has higher blood glucose level which make the salivary glucose level is increased and enters the oral cavity through saliva and gingival crevicular fluid, soaks the biofilm and causes an increase in total biofilm accumulation and started the inflammatory process which causes the alteration in the balance betweenactivated mmps and tissue inhibitors of metalloproteinases (mmps/timps) that control the extracellular matrix, this imbalance result in elevated (mmp-8) level due to increase the neutrophils number migration into the periodontitis lesion which is correlated closely to increase mmp-8 level in gcf and saliva that mainly related to the connective tissue destruction and the periodontitis process will began, also the highly level of salivary glucose result in lowered the salivary slpi and higher the elastase level in saliva and gingival crevicular fluid (30, 31). these j bagh college dentistry vol. 29(2), june 2017 oral health oral diagnosis 69 results are in agreement with other researchers(26, 32,33). in conclusionthe salivary slpi associated inversely with significant correlation with salivary mmp-8 that expressed in periodontal tissues in type i dm and it considers to be a key mediators of the irreversible tissue destruction that associated with periodontitis and correlated positively with poor glycemic control (hba1c >7%). if regular oral screenings and periodontal treatment programs are considered as a standard of care for young patients with type 1 dm, the periodontal diseases can be prevented in these individuals especially at an early stage of diseases. referenceses 1. ship ja. diabetes and oral health: an overview. j am dent assoc. 2003; 134:4s-10s 2. panchbhai a. s., degwekar s. s, and bhowte r. r. “estimation of salivary glucose, salivary amylase, salivary total protein and salivary flow rate in diabetics in india,” journal of oral science 2010; vol. 52, no. 3, pp. 359–368. 3. american diabetes association (ada). diagnosis and classification of diabetes mellitus. diabetes care 2007; 30:s42-s47. 4. rother ki “diabetes treatment-bridging the divide”. the new england journal of medicine 2007; 356(15): 1499-501. 5. aguilarzinser v, irigoyen me, rivera g, maupome g, sanchez perez l, velazquez c. cigarette smoking and dental caries among professional truck drivers in mexico. caries res. 2008; 42 (4): 255-262. 6. deshmukh j, basnaker, kulkarni vk, katti g. periodontal disease and diabetes – a two way street dual highway? people’s journal of scientific research. 2011; 4(2): 65-71. 7. pucher j, stewart j. periodontal disease and diabetes mellitus. currdiab rep 2004; 4:46-50. 8. daković d, pavlović md. periodontal disease in children and adolescents with type 1 diabetes in serbia. j. periodontol 2008; 79(6): 987−992. 9. agrawal a, romero-perez d, jacobsen ja, villarreal fj, cohen sm. zinc-binding groups modulate elective inhibition of mmps. chemmedchem. 2008; 3:812– 820. 10. mäntylä p, stenman m, kinane df, tikanoja s, luoto h, salo t, sorsa t, gingival crevicular fluid collagenase-2 (mmp-8) test stick for chair-side monitoring of periodontitis, j periodontal res 2003; 38(4):436–439. 11. hardy dc, ross jh, schuyler ca, leite rs, slate eh, huang y, matrix metalloproteinase-8 expression in periodontal tissues surgically removed from diabetic and non-diabetic patients with periodontal disease, j clinperiodontol2012, 39(3):249–255. 12. pillay k, coutsoudis a, agadzi-naqvi ak, kuhn l, coovadia hm, janoff en. secretory leukocyte protease inhibitor in vaginal fluids and perinatal human immunodeficiency virus type 1 transmission. j infect dis 2001; 183:653-6. 13. mealey bl, rose 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parihar as, sood m, singh p, singh n. relationship between severity of periodontal disease and control of diabetes (glycated hemoglobin) in patients with type 1 diabetes mellitus. j int oral health 2015;7(suppl 2):17-20. 27. hoggard n, cruickshank m, moar k, et al. using gene expression to predict differences in the secretome of human omentalvs subcutaneous adipose tissue. obesity 2012; 20(6): 1158. 28. nigel hoggard, morven cruickshank, and kim-marie moar. increase in circulating and adipose tissue expression of secretory leukocyte peptidase inhibitor (slpi) with obesity and diabetes. the open nutrition journal 2012; 6, 108-115. 29. lópez-bermejo a, ortega fj, castro a, et al. the alarm secretory leukocyte protease inhibitor increases with progression metabolic dysfunction. clinicachimicaacta 2011; 412(11-12):1122-6. 30. kinney j. s., ramseier c. a., and giannobile w. v. “oral fluidbased biomarkers of alveolar bone loss in periodontitis,”annals of the new york academy of sciences 2007; vol. 1098, pp. 230–251. j bagh college dentistry vol. 29(2), june 2017 oral health oral diagnosis 70 31. isaza-guzm´an d. m., arias-osorio c., mart´ınezpab´on m. c., and tob´on-arroyave s. i. “salivary levels of matrix metalloproteinase (mmp)-9 and tissue inhibitor of matrix metalloproteinase (timp)-1: a pilot study about the relationship with periodontal status and mmp-9-1562c/t gene promoter polymorphism,” archives of oral biology 2011; vol. 56, no. 4, pp. 401–411. 32. lalla e, cheng b, lal s, kaplan s, softness b, greenberg e, et al. diabetes mellitus promotes periodontal destruction in children. j clinperiodontol 2007; 34(4): 294−8. 33. kuehl mn, rodriguez h, burkhardt br, alman ac. tumor necrosis factor-α, matrixmetalloproteinases 8 and 9 levels in the saliva are associated with increased hemoglobin a1c in type 1 diabetes subjects. 2015;plos one 10(4): e0125320. المستخلص تسوس االسنان، التھاب یؤدي الى نقص او غیاب االنسولین ویعتبر یتمیز بارتفاع السكر في الدم والذيأیضي المقدمة: مرض السكري ھو مرض ما حول االسنان من االمراض المزمنة على نطاق واسع في مرض السكري. ان الغرض من الدراسة ھو تحدید اللثة وامراض اللثة و االصحاء ومقارنتھم باالشخاص صحیة للفم بین مجموعة مرضى السكري غیر المنضبطفي اللعاب والحالة الslpi)(وبروتین)mmp-8(انزیم بداء السكري. الغیر مصابین مریض بداء السكري غیر المنضبط 60سنة. مقسمة الى 3518شخص بالغ تتراوح اعمارھم بین 90المواد وطرائق العمل: اشتملت الدراسة المحفز من كل شخص شخصا سلیما غیر مصابین بداء السكري كمجموعة ضابطة.وتم جمع عینات اللعاب غیر 30و ) hba1c>7%(نسبة ، ونسبة التسوس، مدة االصابة بمرض السكري، اختبار الكالیكیتد ھیموغلوبینمؤشر كتلة الجسم تحدیدتم الول من داء السكري ومصاب بالنوع ا -mmp(شر امراض اللثة وما حول االسنان من خالل الزیارة السریریة. وقد تم قیاس مستوى انزیم، مؤشر اللثة، ومؤdmftمن خالل مؤشر التحلیل المناعیةفي اللعاب باستخدام طریقة slpi)(وبروتین)8 مرضى النوع االول لداء السكري مرتفعة وبفرق احصائي معنوي عال مقارنة بالمجموعة الضابطة، ة التسوس لدىظھرت النتائج ان نسبالنتائج: ا فقدان النسیج ووجد ان الحالة الصحیة للفم والتي تشمل مؤشر التھاب اللثة وعمق الجیب ایضا مرتفعة وبفروق معنویة بین المجموعتین باستثناء في اللعاب لدى االفراد المصابین بالنوع )mmp-8(مھمة. واظھرت النتائج ایضا ان مستوى انزیم حیث الیوجد فرق ذات داللة احصائیةالرابط ارتبط )hba1c(وكشفت النتائج ان نسبة منخفض لكن الیوجد فرق معنویة. slpi)(وبروتین االول لداء السكري عالي بالمقارنة مع االصحاء مصابین كبیرة وفي اتجاه ایجابي عند مجموعة الفقدان النسیج الرابط والعالقة مع slpi)(وبروتین)mmp-8(بعالقة احصائیة معنویة مع انزیم بداء السكري غیر المنضبط. معنوي وباتجاه سلبي. slpi)(و )mmp-8(باالضافةالىذلككاناالرتباطبین لدیھ % )hba1c(وعمق الجیب والتھاب اللثة عالي لدى مجموعة مرضى السكري النوع االول غیر المنضبط. dmftاالستنتاج: كانت نسبة في اللعاب ارتباطا معنویا وباتجاه عكسي مع بروتین )mmp-8(انزیم بینما یرتبط فقدان النسیج الرابط، slpi)(، )mmp-8(یجابي معارتباط ا )(slpi. dropbox 10 suzan 51-58.pdf simplify your life juman f.doc j bagh college dentistry vol. 27(3), september 2015 the relation of pedodontics, orthodontics and preventive dentistry146 the relation of salivary glucose with dental caries and mutans streptococci among type1 diabetic mellitus patients aged 18-22 years juman d. alkhayoun, b.d.s., h.d.d., m.sc. (1) ban s. diab, b.d.s., m.sc., ph.d. (2) ali y. al-rubaii, m.b.ch.b, m.sc., f.i.c.m.s. (3) abstract background: diabetic is a chronic systemic disorder of glucose metabolism. that could be diagnosed using fasting and/or random plasma glucose and glycated haemoglobin (hba1c). several biochemical and microbial alterations of saliva could affect dental caries occurrence and severity among diabetic patients. the aim of the present study was to assess the relation of salivary glucose with severity of dental caries and mutans streptococci, among uncontrolled and controlled diabetic groups in comparison with non-diabetic control group. materials and methods: the total sample composed of adults aged (18-22) years. divided into 25 uncontrolled diabetic patients (hba1c > 7), 25 controlled diabetic patients (hba1c ≤ 7), in addition to 25 non-diabetic healthy looking individuals. fasting blood sugar was determined for the diabetic patients. the diagnosis and recording of dental caries was according to severity of dental caries lesion through the application of d1_4mfs (manji et al, 1989) and stimulated salivary samples were collected under standardized condition (tenovuo and lagerlöf, 1994). salivary glucose was estimated using spectrophotometric analysis. viable count of mutans streptococci (on mitissalivarius bacitracin agar) was determined. results: salivary glucose among uncontrolled diabetic group and controlled diabetic group were highly significant higher than control group (p<0.01). analysis among uncontrolled diabetic patients and non-diabetic control group revealed that the salivary glucose correlate positively highly significant with caries experience represented dmfs (p<0.01), while among controlled diabetic group the correlation was not significant in positive direction concerning dmfs (p>0.05). the correlation between salivary glucose and mutans streptococci among three groups was highly significant in positive direction (p<0.01). conclusion: there are significant correlations between salivary glucose, severity of dental caries and mutans streptococci in uncontrolled diabetic group. keywords: diabetic mellitus, salivary glucose, dental caries, mutans streptococci. (j bagh coll dentistry 2015; 27(3):146-151). introduction the world health organization described diabetic mellitus as metabolic disorder of multiple etiology characterized by chronic hyperglycaemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action or both (1). the two main types of diabetes mellitus are type 1 or insulin-dependent diabetes mellitus (iddm) and type 2 or non-insulin-dependent diabetes mellitus (niddm) (2). type 1 diabetes as the name indicates, the patients are totally dependent on exogenous insulin therapy, because all the insulin-producing β cells in the langerhans islets of the pancreas are ultimately destroyed (3). it's only about 30 percent of the risk for type 1 diabetes is genetically determined, while the rest may be related to environmental factors (4). individuals with type 1 diabetes mellitus and poor glycemic control (fbs180mg/dl; hba1c>8) have elevated salivary glucose concentration as a (1) assistant lecture, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (3) consult, poison center in specialized surgeries hospital. result of hyperglycemia, reduction of the salivary glucose clearance, disturbance of the neuroregulatory mechanism of the salivary glands and increased permeability of the basal membrane of the parotid glands (5,6). amer et al (7) conducted a study on diabetic patients and found a significant association between the glucose levels in blood and saliva. the findings thereby indicated that salivary glucose evaluation may be a potential tool to monitor diabetics. according to tenovuo et al (8), the saliva of diabetics contains larger quantities of glucose owing to the leakage of glucose from the blood to the oral cavity, so the increased oral acidity as a result of the excessive amount of salivary glucose causes alteration in dental biofilm, predisposing to colonization by streptococcus mutans and lactobacillus and, thus, dental caries development (5). dental caries is the localized destruction of susceptible dental hard tissues by acids produced by bacterial fermentation of dietary carbohydrates (9). today, mutans streptococci are considered to be the main aetiological microorganisms in caries disease, with lactobacilli and other microorganisms participating in the disease progression (10). j bagh college dentistry vol. 27(3), september 2015 the relation of pedodontics, orthodontics and preventive dentistry147 mutans streptococci have all the requirements for being a caries-inducing group of bacteria, individuals heavily colonized by mutans streptococci were thought to automatically be at high risk for caries (11,12). thus the greater amount of glucose in the saliva of diabetic patients stimulates bacterial growth, increases the production of lactic acid, reducing the ph and decreasing the salivary buffer capacities, which are risk factors for caries (5); and therefore, correlation has been found with caries experience among diabetic patients(13). however the correlation between diabetes mellitus and caries is controversy. high caries-experience among diabetics was reported by (14-16). on the other hand, other studies showed low caries experience among diabetics (17,18). while lin et al (19) reported no difference in caries experience among diabetics and healthy group. the present studies was conducted among patients with type1 diabetic mellitus aged 18-22 years in comparison to control group and to assess the relation of salivary glucose with severity of dental caries and mutans streptococci, among uncontrolled and controlled diabetic groups in comparison with non-diabetic control group. materials and methods in the present investigation, the study group included 50 diabetic adults, with an age range of 18-22 years of both gender. they were examined at the diabetic and endocrinology center, alkindy teaching hospital in baghdad city during the period from the first of november 2011 till the end of april 2012. they were all with confirmed diagnosis of type iddm with minimum duration of diabetes of at least 5 years (5-10years). the samples were divided into two groups based on the hba1c (2): 25 uncontrolled type 1 diabetes mellitus (hba1c > 7) patients, 25controlled type 1 diabetes mellitus (hba1c ≤ 7) patients and non-diabetic subjects as a control group were included 25 healthy students of both gender from college of dentistry/ university of baghdad who did not suffer from any systemic diseases with an age range of 18-22 years and monitored their capillary blood glucose closely prior to the study, and matching with the study group. caries experience was recorded according to the criteria manjie et al. (20) this allows recording decayed lesion by severity. saliva was collected for diabetic patients at the same day of blood sample aspiration for hba1c assessment by measuring the absorbance of the glycohemoglobin and of the total hemoglobin fraction at 415 nm in comparison with a standard glycohemoglobin preparation carried through the test procedure (human-biochemical, 2011, germany). the collection of stimulated salivary samples was performed under standard condition according to tenovuo and lagerlöf (21). the salivary samples were taken to the laboratory for microbiological analysis. saliva was homogenized by vortex mixer for two minutes. ten fold serial dilutions were prepared using normal saline, two dilutions were selected and inoculated on the mitissalivarius bacitracin agar (msb agar) (the selective media for mutans streptococci) (22). identification of mutans streptococci includes: colony morphology; gram’s stain according to koneman et al (23); motility; catalase production (23). ctamannitol media had been used to test the ability of mutans streptococci to ferment the mannitol (24). then biochemical analyses of salivary samples were done by using spectrophotometric analysis. salivary glucose level was measured by enzymatic method glucose-oxidase method, according to srinivasan et al (25). glucose level concentrations of saliva were expressed in mg/dl. glucose conc.(mg/dl)= ×100(standard conc.) intra and inter calibration were performed to overcome any problem that could be faced during the research, and to ensure proper application of diagnostic criteria used in recording dental status through inter calibration. statistical analysis and processing of the data were carried out using spss version 18. the statistical tests included anova and lsd tests, paired and student's ttest and pearson's correlation coefficients. the level of significance was accepted at p< 0.05, and highly significance when p< 0.01. results the percentage of dental caries occurrence in the present study was 100% in diabetes mellitus patients, while in control group (non-diabetic subjects) was 88%. table 1 illustrates the severity of dental caries represented by grades of decayed fraction among study and control groups. the higher mean value was d3 among uncontrolled diabetic group and d2 among controlled diabetic group while among control group the higher mean value was d1 than other grades of ds. however the mean values of all grades were found to be higher among uncontrolled diabetic group than other groups except for grade d1 as the higher mean value was among control group than other two groups. concerning these difference data analyses showed highly significant difference concerning grade d1, d2, d3 and d4 (f-value= 5.14, 15.26, 37.41 and 6.11 respectively p<0.01) among study and control groups. however l.s.d. j bagh college dentistry vol. 27(3), september 2015 the relation of pedodontics, orthodontics and preventive dentistry148 test revealed that the mean value was highly significant higher among uncontrolled diabetic group than control groups concerning d2 (m.d. 4.56, p<0.01), d3 (m.d.-16.96, p<0.01) and d4 (m.d. -4.96, p<0.01). while opposite finding was found concerning grade d1 where as the mean value was highly significant higher among control group than uncontrolled diabetic group (m.d. 2.00, p<0.01). the l.s.d. test also revealed that for controlled diabetic group the mean value of d2 was highly significant higher than control groups (m.d. -4.20, p<0.01) and mean value of d3significantly higher than control group (m.d.4.52 p<0.05), and highly significant lower than uncontrolled group (m.d. -12.44, p<0.01), and the same picture was found concerning d4 as the mean value for controlled diabetic was highly significant lower than uncontrolled group (m.d. 4.84, p<0.01). table 2 show salivary glucose level (mg/dl) (mean and standard deviation) among study and control groups. the highest salivary glucose value was represented in the saliva of the uncontrolled diabetic group, followed by the controlled diabetic group then the control group. result revealed that salivary glucose was highly significant differ (f-value 51.892 p<0.01) among three groups. further investigation using l.s.d. test showed that the level of salivary glucose among uncontrolled diabetic group and controlled diabetic group were highly significant higher than control group (m.d.-14.48, -11.56, respectively, p<0.01), while the level of salivary glucose between uncontrolled diabetic and controlled diabetic groups was not significant (p>0.05). the correlation coefficient between salivary glucose and dental caries experience representing by dmfs and ds in addition to its grades d1, d2, d3, d4 are shown in table 3, analysis among uncontrolled diabetic patients revealed that the salivary glucose correlate positively with caries experience including dmfs, ds and its grades d1, d2, d3, d4 and these relations were highly significant only for ds and dmfs ( r= 0.576 and 0.697 respectively p<0.01), and significant concerning d3(r = 0.488 p< 0.05), also the relation was not significant concerning d1, d2 grades. while among controlled diabetic group the correlations were not significant in positive direction concerning, d2, d3, d4, ds and dmfs (p>0.05) opposite result was found for d1 grade as the correlation was not significant in negative direction(p>0.05). the same result was found among control group concerning ds in addition to its grades d1, d2, d3, d4 as the relations were not significant in positive direction(p>0.05) except for dmfs as the relation was highly significant in positive direction (r = 0.536 p<0.01). table 4 illustrates that the correlation of salivary glucose with mutans streptococci was highly significant in positive direction among uncontrolled and controlled diabetic group and control group(r=0.508, r=0.621 and r=0.579 respectively p<0.01). table 1: severity of dental caries represented by grades of d1-d4 (mean and standard deviation) among study and control groups *(p<0.01) highly significant, df=2 table 2: salivary glucose level (mg/dl) (mean and standard deviation) among study and control groups * (p<0.01) highly significant, df=2 severity of dental caries uncontrolled diabetic controlled diabetic control statistical analysis mean ±sd mean ±sd mean ±sd f-value p-value d1 1.04 1.64 1.92 2.36 3.04 2.52 5.14* 0.00 d2 6.36 3.74 6.00 3.60 1.80 2.14 15.26* 0.00 d3 17.88 10.50 5.44 5.79 0.92 3.25 37.41* 0.00 d4 5.56 9.54 0.72 1.48 0.60 2.19 6.11* 0.00 salivary variables uncontrolled diabetic controlled diabetic control statistical analysis mean ±sd mean ±sd mean ±sd f-value p-value salivary glucose 28.92 5.69 26.00 5.80 14.4 4.31 51.892* 0.00 j bagh college dentistry vol. 27(3), september 2015 the relation of pedodontics, orthodontics and preventive dentistry149 table 3: correlation coefficients between salivary glucose and caries experience among study and control groups *(p<0.05) significant, ** (p<0.01) highly significant table 4: correlations coefficients between salivary glucose and mutans streptococci among study and control groups salivary flora uncontrolled diabetic controlled diabetic control group salivary glucose salivary glucose salivary glucose r p r p r p mutans streptococci 0.508** 0.001 0.621** 0.001 0.579** 0.002 * (p<0.01) highly significant discussion diabetes and oral diseases often appear as the two sides of a coin, many patients with established oral diseases suffer from diabetes. researchers in the dental field have suggested that oral diseases (periodontal disease and dental caries) should be included among the complications of diabetes (16, 26). most evidently, not all diabetic patients are at equal risk for oral diseases, and more attention has recently been paid to possible diabetes-related risk factors to identify subjects who are more prone to dental caries. the study groups selected aged 18-22 years, as at these ages the type 1 diabetes mellitus are predominate. however, in the present study it was difficult to have relatives patients as a control group, so, most of individuals among control group were from the students of college of dentistry, this could partly explained the differences in the severity of caries among study groups and control group. since those students relatively differs from study subjects in their socioeconomic and behavior which play a role in the oral hygiene. data of the present study showed that caries experience represented by dmfs and ds components among uncontrolled diabetes group was higher than that with both control diabetes and non-diabetes control group. this result in agree with the results reported by many researches (27-29). however, al-dahan (30) reported an equal result of caries free subjects between control and diabetic groups. further data analysis concerning grades of ds showed that the caries lesion severity represented by d2, d3 and d4 were highly significant higher among uncontrolled diabetes group than both controlled diabetes and nondiabetes control group. in contrast, d1 was highly significant higher among non-diabetes control group than uncontrolled diabetes group .the increased caries experience among uncontrolled diabetes group could be connected with complexity of the etiopathogesis of carious process and attributed to many diabetes-related changes in the salivary flow rate or glucose levels may include the effect of absolute or relative insulin deficiency, which impairs the function of salivary gland cells (31). individuals with type 1 diabetes mellitus and poor glycemic control have elevated salivary glucose concentration as a result of hyperglycemia, reduction of the salivary glucose clearance, disturbance of the neuroregulatory mechanism of the salivary glands and increased permeability of the basal membrane of the parotid glands (5, 6). hyperglycemia-related increased in the salivary glucose level have shown by the result of present study that shown a highly significant higher salivary glucose concentration among diabetic groups than control group. these results are in agreement with reports of other researchers (8,29). also this agrees with previously studies that showed the presence of glucose in saliva of diabetic patients probably reflect the high serum glucose concentration (33). however, other suggested in their report that the measurement of salivary glucose concentration may also represent a simple, quick, and inexpensive method for screening of diabetic autonomic neuropathy (34). on the other hand, tenovuo et al (32) were found high blood glucose did not result in any notable elevation of salivary glucose in some subjects. moreover, high levels of salivary glucose coming from both the serum (via gingival crevicular fluid) and the saliva (35). severity of dental caries uncontrolled diabetic controlled diabetic control mean ±sd mean ±sd mean ±sd d1 0.161 0.44 -0.061 0.77 0.370 0.06 d2 0.066 0.75 0.095 0.65 0.198 0.34 d3 0.488* 0.013 0.319 0.12 0.332 0.10 d4 0.229 0.27 0.116 0.58 0.191 0.36 ds 0.576** 0.00 0.293 0.15 0.298 0.14 dmfs 0.697** 0.00 0.399 0.051 0.536** 0.00 j bagh college dentistry vol. 27(3), september 2015 the relation of pedodontics, orthodontics and preventive dentistry150 the greater amount of glucose in the saliva stimulates bacterial growth (alteration in dental biofilm) predisposing colonization by streptococcus mutans and lactobacillus (31). this also shown in present study by highly significant positive relation between cfu of mutans streptococci and salivary glucose among diabetic groups, as well as in previous studies (5,36). one can suggest from the data of present study that elevation of glucose levels in the oral cavity will lead to increase acid production by cariogenic bacteria and reducing ph, thus decrease salivary buffer capacities (36) and this will enhance the cariogenic challenge and contribute to the development of the carious lesions as shown by analysis the data of present study the significant positive relation between salivary glucose and caries experience (ds and d3). the streptococcus mutans is the main microorganism responsible for the occurrence of dental caries in humans due to its ability to adhere to tooth surface (37). high levels of these bacteria in saliva can be considered a reasonable indicator of a cariogenic environment in the mouths of uncontrolled diabetes subjects, this is also shown by the data of present study that showed the severity of caries lesion was highly significant (or significant) correlated in positive direction with salivary mutans streptococci in all groups. these results are in agreement with reports of other iraqi researchers (11,12,38). in contrast, data of the present study showed that caries experience represented by d1 among uncontrolled diabetes group was inverse not significant correlation with salivary mutans streptococci, this may be due to the frequency of d1 and d2 grades were low among uncontrolled diabetes group, and the frequency of d4 grade was low among control group. in conclusion, dental professionals need to have comprehensive knowledge of their patients’ diabetes: knowledge that the patient has diabetes is not sufficient to assess the effects of diabetes with respect to oral diseases and dental treatment. this need is emphasized by the high and ever increasing number of patients with diabetes in iraq. on the other hand, the members of the team responsible for diabetes treatment should pay attention to dental care and guidance to dental treatment. finally, co-operation and consultation between all the members of the team responsible for the treatment of patients with diabetes is highly recommended. references 1. world health organization (who): definition, diagnosis and classification of diabetes mellitus and its complication. part 1: world health organization, geneva; 1999. 2. american diabetes association (ada). diagnosis and classification of diabetes mellitus. diabetes care 2007; 30: s42-s47. 3. beers mh, porter rs, jones tv. the merck manual of diagnosis and therapies: endocrine and metabolic disorders. section 2.chapter13. merck research laboratories. glasgow. washington. 2006. 4. knip m, åkerblom hk. environmental factors in the pathogenesis of type 1 diabetes mellitus. exp clin endocrinol diabetes 1999; 107(suppl 3): s93–s100. 5. siudikiene j, machiulskiene v, nyvad b. dental caries increments and related factors in children with type 1 diabetes mellitus. caries res 2008; 42: 354 -62. 6. jurysta c, bulur n, oguzhan b. salivary glucose concentration and excretion in normal and diabetic subjects. j biomed biotechnol 2009; 209: 426-30. 7. amer s, yousuf m, siddqiui pq, alam j. salivary glucose concentrations in patients with diabetes mellitus–a minimally invasive technique for monitoring blood glucose levels. pak j pharm sci 2001; 14(1): 33-7. 8. tenovuo j, lehtonen op. immunological and innate antimicrobial factors in whole saliva of patients with iddm. j dent res 1986; (65): 62-6. 9. marsh p, martin m. oral microbiology. 5th ed. oxford: wright; 2009. 10. sakeenabi b, hiremath ss. dental caries experience and salivary streptococcus mutans, lactobacilli scores, salivary flow rate and salivary buffering capacity among 6 year old indian school children. j clin exp dent 2011; 3(5): e412-7. 11. al-mizraqchi a. microbiological and biochemical studies on adherence of mutans streptococci on the tooth surfaces. ph.d. thesis, university of almustansiriya, 1998. 12. abul-eise zn. maternal caries experience and salivary mutans streptococci in relation to their children in baghdad city. a master thesis, college of dentistry, university of baghdad, 2001. 13. al-sagri a. oral health status of iraqi diabetic patients' salivary and microbial analysis. ph.d. thesis, college of dentistry, university of baghdad, 2005. 14. twetman s, johansson i, birkhed d, nederfors t. caries incidence in young type 1 diabetes mellitus patients in relation to metabolic control and cariesassociated risk factors. caries res 2002; 36(1): 31-5. 15. lopez m, colloca m, paez r, schulimach j, koss m, chervonagura a. salivary characteristics of diabetic children. braz dent j 2003; 14(1): 26-31. 16. bakhshandeh s, murtomaa h, vehkalahti mm, mofid r, suomalainen k. dental findings in diabetic adults. caries res 2008; 42(1):14-8. 17. leeper sh, kalkwarf kl, strom ea. oral status of "controlled” adolescent type 1 diabetics. j oral med 1985; 40: 127–33. 18. kirk jm and kinirons mj. dental health of young insulin dependent diabetic subjects in northern ireland. community dent health 1991; 8: 335–41. 19. lin bp, taylor gw, allen dj, ship ja. dental caries in older adults with diabetes mellitus. spec care dentist 1999; 19(1): 8-14. 20. manji f, fejerkov o, baelum v. pattern of dental caries in an adult rural population. caries res 1989; 23: 55-62. 21. tenovuo j, lagerlöf f. saliva. in thylstrup a, fejerskov o (eds.). textbook of clinical cardiology. 2nd ed. copenhagen: munksgaard; 1994. p. 17-43. j bagh college dentistry vol. 27(3), september 2015 the relation of pedodontics, orthodontics and preventive dentistry151 22. gold og, jordan hv, van haute j. a selective medium for streptococcus mutans. arch oral biol 1973; 18: 1357-64. 23. koneman ew, schreeckenberge pc, allens sd, janda wm. diagnostic microbiology.4th ed. st. louis: j.b. lippincott co.; 1992. 24. brown af. benson's microbiological applications. laboratory manual in general microbiology. 9th ed. new york: mcgraw-hill; 2005. 25. srinivasan a, maaly e, willy d. determination of glucose in blood using glucose oxidase. am clin biochem 2003; 6: 24-9. 26. lamster ib, lalla e. periodontal disease and diabetes mellitus: discussion, conclusions, and recommendations. ann periodontol. 2001; 6:146-149. 27. el-samarrai s, sabri n, makki z. dental caries among young diabetic patients in baghdad-iraq. iraqi dent j 1997; 20: 14-23. 28. twetman s, petersson gh, bratthall d. caries risk assessment as a predictor of metabolic control in young type 1 diabetics. diabet med 2005; 22: 312 -5. 29. iqbal s, kazmi f, asad s. dental caries and diabetes mellitus. pak oral & dent j 2011; 31(1): 60-3. 30. al-dahan z. oral health status among iddm on population group of teenagers in baghdad-iraq. a master thesis, college of dentistry, university of baghdad, 1991. 31. sampaio n, mello s, alves c. dental cariesassociated risk factors and type 1 diabetes mellitus. pediatric endocrinology, diabetes and metabolism 2011; 17(3): 152-7. 32. tenovuo j, alanen p, larjava h, vilikari j, lehtonen op. oral health of patients with insulin-dependent diabetes mellitus. scand j dent res 1986; 94:338– 346. 33. karjalainen k. periodontal diseases, dental caries, and saliva in relation to clinical characteristic of type1 diabetes. ph.d. thesis, faculty of medicine, institute of dentistry, university of oulu, finland, 2000. 34. martí álamo s, jiménez soriano y, sarrión pérez mg. dental considerations for the patient with diabetes. j clin exp dent 2011; 3(1): 25-30. 35. siudikiene j, machiulskiene v, nyvad b, tenovuo j, nedzelskiene i. dental caries and salivary status in children with type 1 diabetes mellitus, related to the metabolic control of the disease. eur j oral sci 2006; 114: 8-14. 36. alves c, andion j, brandao m, menezes r. mecanismos patogenicos da doença periodontal associada ao diabetes melito. arq. bras. endocrinol. metab. 2007; 51:1050-7. 37. thanyasrisung p, komatsuzawa h, yoshimura g. automutanolysin disrupts clinical isolates of cariogenic streptococci in biofi lms and planktonic cells. oral microbiol. immunol 2009; 24: 451-5. 38. al-hayali am. isolation and purification of glucosyltransferase from mutans streptococci and its relation to dental caries, dental plaque and parameters of saliva. ph.d. thesis, college of dentistry, university of baghdad 2002. الخالصة دامباستخ أو بقیاس كمیة السكر بالدم في حالة الصیام ویمكن االستدالل علیھ, داء السكر ھو مرض مزمن ناتج من االختالل في عملیة ایض الكلوكوز :المقدمة عند األسنانالتي لھا تأثیر واضح في حدوث وانتشار تسوس , في اللعاب ةوالمیكروبیھنالك العدید من التغیرات البایوكیمائیة . اختبار الكالیكیتد ھیموغلوبین .مرضى السكر بكتریا المكورات المسبحیة المیوتنس لمرضى السكر ومقارنتھم األسنان وشدة تسوس سطوح مع عالقة كمیة الكلوكوز باللعاب مالغرض من الدراسة ھو تقی أن .غیر المصابین بداء السكر األصحاء باألشخاص مریض بداء السكر hba1c) <7 ( ,25مریض بداء السكر غیر المنضبط 25, سنة 22-18شخص بعمر 75أشتملت الدراسة :المواد وطرائق العمل كان . تم قیاس نسبة السكرفي الدم في حالة الصیام لجمیع المرضى.بداء السكر كمجموعة ضابطة ما غیر مصابین شخصا سلی 25و ) hba1c) ≥7 المنضبط جمعت العینة اللعابیة تحت ظروف موحدة وتم جمع عینات اللعاب ).d1-4mfs ) manji et a1,1989التشخیص وحساب شدة التسوس من خالل تطبیق مؤشر تم تحلیل عینات اللعاب كیمیائیا لغرض تحدید مستوى الكلوكوز باللعاب بأستخدام المطیاف . )tenovuo and lagerlöf ) 1994 المحفز اعتمادا على طریقة .الضوئي اضافة الى تحلیل اللعاب مایكروبایولوجیا لتحدید مستوى تواجد بكتریا المكورات المسبحیة المیوتنس نات اللعاب ان مستوى تركیز الكلوكوز باللعاب عند مرضى السكرغیر المنضبط ومرضى السكر المنضبط كانت اظھرت نتائج التحلیل البایوكیمیائي لعی: النتائج ووجد ان مستوى تركیز الكلوكوز باللعاب ارتبط بعالقة احصائیة عالیة .مقارنة بمستواه في لعاب المجموعة الضابطة مرتفعة وبفرق احصائي معنوي عاٍل بینت النتائج ان مستوى تواجد بكتریا المكورات كما .عند مرضى السكر غیر المنضبط والمجموعة الضابطة dmfs سنانالمعنویة مع دالة سطوح اال .عند كل المجامیع الخاضعة للدراسةكمیة سكرالكلوكوزفي اللعاب المسبحیة المیوتنس ارتبط بعالقة موجبة عالیة المعنویة مع .مرضى السكر غیر المنضبطلعاب عند األسنان و تواجد بكتریا المكورات المسبحیةتسوس شدة , ة سكر الكلوكوزھنالك عالقة معنویة بین كمی :االستنتاج dropbox 16 yasir 86-91.pdf simplify your life 11. ahlam f .doc j bagh college dentistry vol. 27(4), december 2015 validity of oral diagnosis 72 validity of 3d reconstructed computed tomographic image in using craniometrical measurements of the skull for sex differentiation (an iraqi study) noor m. sadeq, b.d.s. (1) ahlam a. fatah, b.d.s., m.sc. (2) abstract background: the skull offers a high resistance of adverse environmental conditions over time, resulting in the greater stability of the dimorphic features as compared to other skeletal bony pieces. sex determination of human skeletal considered an initial step in its identification. the present study is undertaken to evaluate the validity of 3d reconstructed computed tomographic images in sex differentiation by using craniometrical measurements at various parts of the skull. materials and method: 3d reconstructed computed tomographic scanning of 100 iraqi subject, (50 males and 50 females) were analyzed with their age range from20-70 years old. craniometrical linear measurements were located and marked on both side of the 3d skull images. results: for the all parameters measured for sexes the mean value for male had significantly greater than females with (p value < 0.001). a receiver operating characteristic curves was obtained for each variable to observe their overall performance in sex determination. the area of mastoid triangle was found the best variable in sex differentiation (roc area =0.97 for unilateral skull measurements and 0.98 for bilateral measurements).while eu-eu was found to be the least one. conclusion: 3d reconstructed computed tomography scanning is a good diagnostic method for analyzing the craniometrical measurements of sex determination. sex differentiation for isolated part of the skull when only the fragmentary crania is available, could be achieved and the highest accuracy in sex determination can be obtained whether part or complete skull available. keyword: sex determination, 3d reconstructed computed tomography, mastoid process, sexual dimorphism. (j bagh coll dentistry 2015; 27(4):72-77). introduction human identification is one of the major and most important tasks of forensic medicine and dentistry. the identification of a deceased individual holds social, economic and legal repercussions. soft tissues are commonly no longer present, due to carbonization, trauma or advanced decomposition. in those cases, forensic anthropology serves an important role in human identification (1,2). before puberty, it is virtually impossible to diagnose sex by visual examination of the human skull. after this period, as a result of hormone action, distinctive sexual characteristics become more apparent, male muscles gain mass and power, and bones begin to exhibit significant differences between sexes(3). however, there is no single male skull trait that identifies a skull as being male or female. rather, it is a set of traits that determine one sex or the other(4,5). the skull is a very useful alternative to determine sex in the absence of the pelvis because of its prominent morphological differences between the two sexes, attributed to different genetic makeup as well as the acquired changes that occur during pubertal growth and it has a high resistance to adverse environmental conditions over time, resulting in (1) master student. department of oral diagnosis, college of dentistry, university of baghdad (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. the greater stability of the dimorphic features as compared to other skeletal bone pieces(6,7). the highest accuracy in sex determination is achieved when the complete skeleton is available; it is often difficult to identify sex in fragmented remains, as no isolated characteristic of any particular bone can perfectly determine the sex of a skeleton. therefore, it becomes essential then to observe the sex-specific characteristics from as many bones as possible(8). in many such instances, attempts have been made for sex assessment from isolated part of the skull when only fragmentary remains are available, instead of, complete skeletons for forensic identification. henceforth, individual parts of the skull like mastoid process, zygomatic bone, glabella region, hard palate, basal region, occipital condyle, foramen magnum or some other parts have been analyzed by few researchers for sex determination(9-14). 3d-ct imaging has been proven to be more accurate in determining measurements than imaging performed directly on ct slices and 2dct image reconstruction (15). the present study was done to evaluate the validity of 3d reconstructed computed tomographic image in sex differentiation by craniometrical measurements at various parts of the skull. j bagh college dentistry vol. 27(4), december 2015 validity of oral diagnosis 73 materials and methods for this prospective study, total 100 iraqi adults, comprising of 50 males and 50 females, their ages ranging between (20-70) years old were attending to neuroscience hospital in baghdad city taking ct scans for different diagnostic purpose from november 2013 to april 2014. the total study sample divided into the following groups according to different ranges of age selected as shown in table1. table (1): distribution of participating patients according to age and gender groups age rage male female 1 20-29 7 8 2 30-39 11 14 3 40-49 6 10 4 50-59 10 8 5 60-69 16 10 total 50 50 the crania having any pathological lesions affecting the examined area, fracture, or maxillofacial deformities, as well as those subjects with signs of gross facial asymmetry. the examination was performed on multi-slice spiral tomography scanner (the siemens somatom definition as), and the patients were prepared for the exposure by asking them to remove any spectacles, hearing aids, and personal jewelry such as ear rings, necklaces, and hairpins. the patient positioned supine on the ct examination table and the patient’s head positioned in the head rest. the measurement was done by advanced post processing techniques using 3d reconstructed computed tomographic scans; the selected craniometrical points were identified and marked on the both sides of the skulls , the craniometrical points are: porion (po superior point of the external auditory meatus), mastoidale (ms lower tip of the mastoid process), asterion (as –the meeting point of the lambdoid, occipitomastoid and parietomastoid sutures), glabella (g-the most anterior point in the midsagittal plane, between the supraorbital tori), inion (i-the most prominent projection of the occipital bone at the most posterioinferior point of the external occipital protuberance), zygion (zy-the lateral point on the zygomatic bone that marks the greatest bizygomatic diameter), euryon (eu-the lateral point on the parietal bone that marks the greater transverse diameter of the skull), frankfurt horizontal plane—(fh plane): line connecting the porion (superior point of the external auditory meatus) with the orbitale (lowest point of bony orbit)(16,17). the linear measurements between the previous points: (1) porion-mastoidal length (po -ms): it is the straight distance between porion and mastoidal, (right and left). (2) asterion-mastoidale length (as-ms): it is the straight distance between asterion and mastoidale, (right and left). (3) perpendicular distance from mastoidal to frankfort plane (ms-fh): it is the length of the mastoid is measured from a point on the frankfort plane vertically downwards to the tip of the mastoid process (4) glabella-inion (g-i): the distance between the most anterior points on frontal midline to the most prominent projection of occipital bone. (5) zygionzygion (zy-zy): greatest bizagomatic. (6) euryoneuryon (eu-eu): lateral point on the parietal bone which make the greatest transverse diameter of the skull (16, 17). a triangle was designed at mastoid process region from the 2 linear measurements (po-ms) and (as-ms) with the third line drawn between (po) and (as) as shown in figure 1, all linear measurements were made on both sides of the skull for each ct image and the area of demarcated triangle for right and left side of the skull was calculated using (heron’s formula) as the following: s= the sum of three linear measurements heron's formula (h), with sides of triangle a, b&c h= √ ((s(s-a) (s-b) (s-c))) s= ((a+b+c))/2 the total triangular area was calculated by the sum of these two measurements. all measurements were made with cm unit(18) figure 1 3d reconstructed frontal view of female ct image of skull showing mastoid triangle area. figure (1): 3d reconstructed frontal view of female ct image of skull showing mastoid triangle area. j bagh college dentistry vol. 27(4), december 2015 validity of oral diagnosis 74 statistical analysis: data analysis was computer aided. an expert statistical advice was sought for. statistical analysis was done using spss version 21 computer software (statistical package for social sciences). results the presented study was stratified into 2 parts; the first part used the measurements of one side of the skull as a sampling unit. the justification for such strategy is the absence of statistically significant differences between right and left sides of linear craniometrical measurements. in addition a researcher in forensic medicine may be confronted with a situation in which one side of the skull is available for evaluation when gender discrimination is required, this part called “unilateral craniometrical measurements analysis” the second part is called “bilateral craniometrical measurements analysis”. the assumption in this part was the availability of both sides of the skull intact. since no important differences existence between right and left side measurements one can use the mean of both right and left sides as representative for both sides’ measurements. some of the measurements had no right and left side for example (zy-zy, eu-eu, and total mastoid area) therefore they are single measurements representing the skull. for all linear measurements, no statistically differences is observed between right and left side of the skull. unilateral and bilateral craniometrical measurements for the skull stratified by gender: the mean values and standard deviation for the five selected linear measurements of the anatomical landmarks in both male and females showed a highly significant differences between male and female (p<0.001). all the measurements demonstrated in tables (2, 3). table (2): the gender differences in mean of unilateral measurements variables gender differences in mean gender dimorphism cohen’s d p female n(100) male n(100) mean (msfh) 2.65 3.11 0.46 17.4 1.44 <0.001 (gi) 17.09 18.26 1.17 6.8 1.67 <0.001 (po-ms) 2.8 3.3 0.50 17.9 1.79 <0.001 (as-ms) 4.6 5.33 0.73 15.9 1.97 <0.001 mastoid triangle 5.99 8.05 2.06 34.4 2.71 <0.001 table (3): the gender differences in mean of by bilateral measurements variables gender differences in mean gender dimorphism cohen’s d p female n(50) male n(50) mean msfh 2.65 3.11 0.46 17.4 1.48 <0.001 (gi) 17.09 18.27 1.18 6.9 1.69 <0.001 (po-ms) 2.8 3.3 0.50 17.9 1.92 <0.001 (as-ms) 4.6 5.33 0.73 15.9 2.28 <0.001 mastoid triangle 11.97 16.09 4.12 34.4 2.99 <0.001 (zy-zy) 12.2 13.17 0.97 8 2.06 <0.001 (eu-eu) 13.66 14.2 0.54 4 1.13 <0.001 the validity of unilateral and bilateral selected measurements in predicting male sex: receiver operating characteristic analysis (roc) was used to assess the validity of different tested measurements in predicting male sex differentiating from female. among the computed tomographic measurements, as shown in table (4) area of mastoid triangle was associated with the highest validity in the context of gender identification (roc area =0.972 cm),(as-ms) ranked second in its validity when used as a test for differentiating male from female. (roc area=0.925cm), followed by (po-ms), (roc area =0.916 cm). (gi) and (msfh) were the least valid in predicting a male gender (roc area =0.879 and 0.852 cm respectively) although their validity is still height. while for bilateral selected parameters, as shown in table (4), area of mastoid triangle was associated with the highest validity in j bagh college dentistry vol. 27(4), december 2015 validity of oral diagnosis 75 the context of gender identification (roc area =0.985 cm). (as-ms) and (zy-zy) ranked second in there’s validity when used as a test for differentiating male from female (roc area=0.947cm and 0.924) respectively followed by (po-ms), (roc area =0.919 cm). followed by (gi) (roc=.0883), (msfh) and (eu-eu) were the least valid in predicting a male gender (roc area =0.867 and 0.774 cm respectively) although their validity is still height. the age shows no statistical significance difference in mean values of selected measurements between the five age groups for both unilateral and bilateral measurements. table (4): roc area for selected parameters when used as test to predict male gender differentiating them from female. variables roc p u ni la te ra l m ea su re m en ts (msfh) 0.852 <0.001 (g-i) 0.879 <0.001 (po-ms) 0.916 <0.001 (as-ms) 0.925 <0.001 area of mastoid triangle 0.972 <0.001 bi la te ra l m ea su re m en ts (msfh) 0.867 <0.001 (g-i) 0.833 <0.001 (po-ms) 0.919 <0.001 (as-ms) 0.947 <0.001 area of mastoid triangle 0.985 <0.001 (zy-zy) 0.924 <0.001 (eu-eu) 0.774 <0.001 discussion human identification consists of a series of steps to individualize individuals and establish their identity (14). in this respect, forensic anthropology plays an important role in reconstructing the biological profile, taking into consideration its four main components, ancestry, age, stature and sex (19, 20). these factors can be determinants in a unique subject or a large number of unidentified corpses and skeletal remains. such as the case of mass disasters, where correct sex identification reduces the pool of possible missing persons to just 50% of the population (21,22). there are clear limitations in using simple linear measurements to describe the morphology of a complex three-dimensional object as the cranium. but it has used extensively as it is less problematic in statistical analysis(23). spiral ct has brought new technology with faster scan times, allowing an improvement in 3d reconstruction with better detail and visualization of anatomical structures when compared with conventional ct. the value of computer graphics in manipulative craniofacial images and the importance of 3dct images in quantitative and qualitative analysis, a process which provides more information about the craniofacial complex is cleary recognized. computer graphics technology and current workstations allow better visualization and segmentation that enable assessment of volume, area, linear and angular measurements (24,25). the current study relied on 3d reconstructed image based on spiral ct. there is no iraqi literature on the use of 3d reconstructed image of cranium in sex determination was retrieved, making the current work the first of its kind to be explored on iraqi subjects. the variability in the dimensions of the skulls can be explained by reason of that the cranial size determination is multifactorial and influenced by epigenetics factors of high variability among populations, geographical regions, socioeconomic strata, and so on(26). craniofacial growth like mastoid region, zygomatic process and the ridges of occipital bone are influenced by nutrition, environment and genetic factors (27). dayal and bidoms(28) stated that sex estimation can be accomplished using either morphological or metric methodologies. statistical methods utilizing metric traits are becoming more popular, with most of bones having been subjected to linear discriminant classification. in the current study, the mean of both unilateral and bilateral craniometrical linear measurements for males were significantly higher than that for female .the gender effect on these tested linear measurements ranged from strong to very strong effect when evaluated by cohen’s for effect size, this may be attributed to the fact that females reach skeletal maturity two years earlier than males allowing for longer growth period in males, and also to genetic and hormonal factors(29-32). among all the measurements used in the current study, for both unilateral and bilateral craniometrical linear measurements, the mastoid area was the most important in gender dimorphism, being associated with the highest effect size estimated by cohen’s. sukumar et, al.,(33) adopt area of mastoid triangle in sex discrimination in their study where done on a sample of 30 adults males and 30 adult female lining subjects using 3d reconstructed image of spiral ct, the found of mastoid triangle area was j bagh college dentistry vol. 27(4), december 2015 validity of oral diagnosis 76 significantly in males compared to females. the mastoid region is one of the slowest and later growing regions of cranium and such regions show higher degree of sexual dimorphism in adulthood. moreover, the differences in size of the mastoid process between sexes could be attributed to the variable duration of growth in males and females, along with relatively greater development of the mastoid process in males in response to stronger muscle action of the sternocleidomastoideus, splenius capitis (the posterior belly of the digastric muscle), and longissimus capitis. also, these muscles are attached over a relatively larger area in males(7, 34). for (zy-zy) we noticed that the mean values of male significantly higher than for females in both unilateral and bi, with a very strong effect of (cohen’s d), followed the total mastoid area, while the (eu-eu) had the lowest value of (cohen’s d) among other variable but still strong. bizygomatic width reflects growth at maxilla and orbital region in lateral direction. extended growth in male causes the malars to be large and the zygomatic arch to be displaced more laterally than the corresponding structures in the female thus males have definitely larger bizygomatic width, thus providing robustness in male facial skeleton (7), while for (msfh) and (gi) we noticed that the mean values of male was significantly higher than for females, with a very strong effect of (cohen’s d) in both unilateral and bilateral craniometrical linear measurements, the validity of selected measurements in predicting male sex: the use of roc curve to find out an optimal cut off point for discriminant of sex (for classification of male and female) in each variable and comparing the performance of each variable using its (auc) is helpful in determination of sex specially in classes of fragmentary crania (unilateral measurements)(8). from our finding, we notice that the use of bilateral measurements is associated with a very small increase in validity of gender discrimination. the increase in roc area observe when substituting a unilateral for bilateral measurements is almost negligible not exceeding 1%. the mastoid triangle was defined by 3sides, namely po-ms and ms-as, and po-as. the po-ms and as-ms were associated with the highest validity in sex determination among the 3 sides of mastoid triangle (roc area =0.919 and 0.947 respectively) this finding was agreed with sukumar et, al.,(33) were use the heron’s formula. it was found that measuring the mastoid area using heron’s formula improved the prediction accuracy of gender to an almost perfect test (roc area =0.97 for unilateral skull measurements and 0.98 for bilateral method). similar finding reporting by saini et, al.,(35) studied 138 north indian adult crania and they found that (po-ms) and (as-ms) were the two mastoid triangle sides associated with the most effective single measurement with highest validity (roc area of 0.787 and 0.798 respectively). (zy-zy) ranked a good test in there validity when used as a test for differentiating male from female with accuracy of 86%. followed by (gi) and (msfh) with 84% and 80% accuracy, while the (eu-eu) ranked as fair test and the least valid in predicting a male gender with71% accuracy. references 1. graw m, wahl j, ahlbrecht m. course of the meatus acusticus internus as criterion for sex differentiation. forensic sci int 2005; 147(2-3): 113-7. 2. patil kr, modi rn. determination of sex by discriminant function analysis and stature by regression analysis: a lateral cephalometric study. forensic sci int 2005; 147(2-3):175-80. 3. loth sr, henneberg m. mandibular ramus flexure: a new morphologic indicator of sexual dimorphism in the human skeleton. am j phys antropol 1996; 99(3): 473-85. 4. arbenz g.o. medicina legale antropologia forense. são paulo. atheneu; 1988. 5. madeira mc. anatomia da face: bases anatomofuncionais para a prática odontológica.5th ed. são paulo: sarvier; 2004. p.133-4. (portuguese) 6. scheuer l. application of osteology to forensic medicine. clin anat 2002; 15(4): 297–312. 7. rogers tl. determining the sex of human remains through cranial morphology. j forensic sci 2005; 50(3): 493–500. 8. sanini v, srivastava r, rai rk, shamal sn, singh tb, tripathi sk, sex estimation from mastoid process among north indians. j forensic sci 2012; 57(2): 434-9. 9. gunay y, altinkok m. the value of the size of the foramen magnum in sex determination. j clinical forensic med 2000; 7(3):147-9. 10. gapert r, black s, last j. sex determination from the occipital condyle: discriminant function analysis in an eighteenth and nineteenth century british sample. am j phys anthropol 2008;138(4): 384-94. 11. nagaoka t, shizushima a, sawada j, tomo s, hoshino k, sato h. sex determination using mastoid process measurements: standards for japanese human skeletons of the medieval and early modern periods. anthropological sci 2008; 116(2):105-13. 12. suazo gic, zavando mda, smith rl. sex determination using mastoid process measurements in brazilian skulls. int j morphol 2008; 26(4): 941-4. 13. galdames ics, russo pp, matamala daz, smith rl. sexual dimorphism in the foramen magnum dimensions. int j morphol 2009; 27(1): 21-3 14. wescott dj, moore-jansen ph. metric variation in the human occipital bone: forensic anthropological j bagh college dentistry vol. 27(4), december 2015 validity of oral diagnosis 77 applications. j forensic sci 2001; 46(5):1159-63. 15. fishman ek, magid d, ney dr, chaney el, pizer sm, rosenman jg, levin dn, vannier mw, kuhlman je, robertson dd. three-dimensional imaging. radiol 1991; 181(2): 321-37. 16. oliverira of, ribeiro rl, júnior ed, sayuri a, terada ds, henrique r, silva ad, renato l, paranhos lr. sexual dimorphism in brazilian human skulls: discriminant function analysis. j forensic odontostomatol 2012; 30(2) 26-33. 17. sukumar s, yadav s, vipinkumar. sex determination by mastoid process in south indian population by 3d computer tomography imaging. ijpbs 2012; 2(4):193-195. 18. bhagya b, hema n, ramakrishna a. validation metrics of the mastoid triangle. nujhs 2013; 3(2): 2249-7110. 19. prabhu s, acharya ab. odontometric sex assessment in indians. forensic sci int 2009; 192(1-3): 129.e1–5 20. pereira c, bernardo m, pestana d, santos jc, mendonça de mc. contribution of teeth in human forensic identificationdiscriminant function sexing odontometrical techniques in portuguese population. j forensic legal med 2010; 17(2): 105–10. 21. coma jmr. antropologia forense. madrid. centro de publicaciones; 1991. 22. acharya ab, mainali limitations of the mandibular canine index in sex assessment. j forensic legal med 2009; 16(2): 67–9. 23. mays s. biodistance studies using craniometric variation in british archeological skeletal material in: cox m, mays s, editors. human osteology: in archaeology and forensic sciences. cambridge: cambridge university press; 2000. p. 277-88. 24. vannier mw, pilgram tk, marsh jl. craniosynostosis: diagnostic imaging with threedimensional ct presentation. ajnr 1994; 15(10):1861-9. 25. kane aa, lo lj, vannier mw, marsh jl. mandibular dismorphology in unicoronal synostosis and plagiocephally without synostosis. cleft palate craniofac j 1996; 33(5): 418 23. 26. zavando da, suazo ic, smith rl. sexual dimorphism determination from the lineal dimensions of skulls. int j morphol 2009; 27(1):1337. 27. suazo gic, zavando mda, smith rl. evaluating accuracy and precision in morphologic traits for sexual dimorphism in malnutrition human skull: a comparative study. int j morphol 2008; 26(4):876– 83. 28. dayal mr, bidmos ma. discriminating sex in south african blacks using patella dimensions. j forensic sci 2005; 50(6):1294-7. 29. bass wm. human osteology. a laboratory and field manual. 3rd ed. columbia: missouri archeological society; 1987. 30. iscan my. rise of forensic anthropology. yearb phys anthropol 1988; 31: 203-30. 31. mays s, cox m. sex determination in skeletal remains. in: cox m, mays s (editors). human osteology in archaeology and forensic science. cambridge: cambridge university press; 2000. p. 117-30. 32. white td. human osteology. 2nd ed. new york: academic press; 2000. 33. sukumar s, yadav s, vipinkumar. sex determination by mastoid process in south indian population by 3d computer tomography imaging. ijpbs 2012; 2(4):193-5. 34. humphrey lt. growth pattern in modern human skeleton. am j phys anthropol 1998; 105(1): 57–72. 35. sanini v, srivastava r, rai rk, shamal sn, singh tb, tripathi sk, sex estimation from mastoid process among north indians. j forensic sci 2012; 57(2): 434-9. aws final.doc j bagh college dentistry vol. 26(3), september 2014 assessment of serum oral diagnosis 53 assessment of serum and salivary ceruloplasmin level in patients with oral lichen planus aws w. abbas, b.d.s., m.sc. (1) taghreed f. zaidan, b.d.s., m.sc., ph.d. (2) abduladheem y. abbood al-barrak, b.sc., m.sc., ph.d. (3) abstarct background: oxidative stress is a deleterious process that can be an important mediator of damage to cell structures and consequently various disease states. exposure to free radicals from a variety of sources has led organisms to produce a series of defense mechanisms. the antioxidant ceruloplasmin is a copper-containing ferroxidase that can oxidize ferrous iron (fe2+) to its nontoxic ferric (fe3+) form. ferrous iron (fe2+) is extremely damaging because of its ability to generate toxic free radicals. oral lichen planus (olp) is a chronic inflammatory oral mucosal disease of unknown etiology. previous studies reported that reactive oxygen species may be involved in the pathogenesis of lichen planus. the aim of this study was to estimate the role of oxidative stress in pathogenesis of olp through the study of serum and saliva ceruloplasmin as a marker of antioxidant status. methods: forty eight patients with histologically confirmed olp by oral pathologist were included in this study. the sample group was split up in to two groups according to the clinical presentation of the lesions, 21 patients with reticular formation and 27 patients with erosive form together with 32 healthy looking volunteers that were agematched with the patients. serum and saliva ceruloplasmin activity was determined by oxidation of pphenylenediamine to give a blue violet color that measured spectrophotometricaly at 525 nm. results: statistically, there was a substantial increase in serum and saliva ceruloplasmin levels of olp patients group as compared to controls (p<0.01) and there was no statistically significant differences in serum and saliva ceruloplasmin when compared between reticular and erosive forms (p>0.05). the study showed that there was no statistically significant correlation between serum and saliva ceruloplasmin levels in olp patients group (r=-0.029, p>0.05). conclusion: oxidative status play a role in the pathogenesis of oral lichen planus represented by increased serum and saliva ceruloplasmin levels. keywords: oral lichen planus, ceruloplasmin, serum, saliva. (j bagh coll dentistry 2014; 26(3):53-57). introduction reactive oxygen species (ros) are highly reactive molecules and can damage cell structures. the shift in the balance between oxidants and antioxidants is termed oxidative stress. aerobic organisms have integrated antioxidant systems, which include enzymatic non enzymatic antioxidants that are usually effective in blocking harmful effects of ros. however, the antioxidant systems can be overwhelmed (1) which may play a key role in the onset and development of several inflammatory oral pathologies (2). the potent antioxidant activity of normal human plasma has been shown to be chiefly dependent upon the copper-containing protein ceruloplasmin (cp) and the iron-binding protein transferrin (3,4). oral lichen planus (olp) is a chronic inflammatory oral mucosal disease of unknown etiology (5). basically there are two categories of oral lesions; reticular and erosive (6). the atrophic, ulcerative, and bulbous forms of the disease are referred to as erosive lichen planus (7). (1) ph.d. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. (3) assistant professor, department of microbiology, college of medicine, al-mustansiriya university reticular pattern is the most frequent clinical presentation and appears in the form of a network of connections and overlapping white lines (8) combined with a few symptoms and reflecting a milder stage of the disease (9,10). erosive/ulcerative olp constitute the most destructive pattern and causes a great oral discomfort (8,10). the purpose of this study is to assess the antioxidant status and its role in the pathogenesis of olp through the study of serum and saliva cp levels. materials and methods forty eight patients with histologically confirmed olp were included in this study. a diagnosis of oral lichen planus was made based on clinicopathologic correlation according to the modified who diagnostic criteria for olp (11). the sample group was split up in two groups according to the clinical presentation of the lesions, 21 patients with reticular formation and 27 patients with erosive form together with 32 healthy looking volunteers that were age-matched with the patients. serum and unstimulated whole saliva were collected from each subject then the supernatant serum and saliva was obtained by centrifugation at 3000 rpm for 10 minutes then aspirated and j bagh college dentistry vol. 26(3), september 2014 assessment of serum oral diagnosis 54 transferred immediately into eppendorf tubes and frozen at -20 °c for subsequent analysis. ceruloplasmin activity was determined by oxidation of p-phenylenediamine to give a blueviolet color that measured spectrophotometricaly at 525 nm (12). results the mean age of the patient group was 50.96 ±10.55 with female predilection 52.1%. the present study revealed that the mean of serum cp in patients with olp (0.408±0.101 g/l) was significantly higher (p<0.001) by using t-test than that of control group (0.311±0.105 g/l). (table 1) (figure 1) the mean of saliva cp in patients with olp (0.014±0.009 g/l) was significantly higher (p<0.01) by using t-test than that of control group (0.009±0.009 g/l). (table 2) (figure 1) table 1: mean of serum ceruloplasmin in olp patients and controls serum ceruloplasmin (g/l) patients controls no 48 32 mean±sd 0.408±0.101 0.311±0.105 standard error of mean 0.015 0.018 mode 0.299 0.224 range 0.274-0.710 0.188-0.619 percentile 05th 0.299 0.202 25th 0.338 0.240 50th (median) 0.393 0.292 75th 0.448 0.346 95th 0.613 0.618 99th 0.710 .619 p value 0.0001* * highly significant using students-t-test for difference between two independent means at 0.01 level table 2: mean of saliva ceruloplasmin in olp patients and controls saliva ceruloplasmin (g/l) patients controls mean±sd 0.014±0.009 0.009±0.009 standard error of mean 0.001 0.002 mode 0.013 0.003 range 0.003-0.056 0.002-0.035 percentile 05th 0.004 0.003 25th 0.008 0.003 50th (median) 0.013 0.006 75th 0.018 0.010 95th 0.034 0.034 99th 0.056 0.035 p value 0.01* * highly significant using students-t-test for difference between two independent means at 0.01 level 0.408 0.014 0.311 0.009 0 0.1 0.2 0.3 0.4 0.5 0.6 serum of patients saliva of patients serum of controls saliva of controls mean ceruloplasmin ( g/l) figure 1: mean of ceruloplasmin conc. in serum and saliva of olp patients and control groups j bagh college dentistry vol. 26(3), september 2014 assessment of serum oral diagnosis 55 the present study showed that there was no statistically significant difference in serum and saliva cp between patients with reticular and patients with erosive form of olp. (table 3). this study showed that there was no statistically significant correlation (r =-0.029, p>0.05) between serum and saliva measurements of cp in patients with olp. (figure 2) table 3: comparison of serum and saliva ceruloplasmin levels between reticular and erosive forms of olp patients group type reticular erosive p value ceruloplasmin (g/l) serum 0.418 ± 0.130 0.400 ± 0.072 0.549 saliva 0.013 ± 0.007 0.015 ± 0.011 0.394 figure 2: correlation between serum and saliva ceruloplasmin in olp patients group discussion the exact etiology of olp is unknown. cell mediated immune deregulation has been associated with the pathogenesis of this condition (13). anshumalee et al in 2007 reported that oxidative stress may play a role in olp (14). reactive oxygen species (ros), superoxide anions, hydroxyl radical, hydrogen peroxide and nitric oxide, are highly reactive, diffusible molecules (15). cells generate ros intracellularly and may release them extracellularly (16) which may damage surrounding tissues and promote inflammatory processes (17). metals such as iron and copper are capable of redox cycling in which a single electron may be accepted or donated by these metals. this action catalyzes reactions that produce reactive radicals (18). iron is essential for a variety of cellular functions, but its levels and bioavailability must be tightly regulated because of its toxic redox activity. the multi-copper ferroxidase cp converts toxic ferrous iron (fe2+) to its nontoxic ferric form (fe3+) and is required for iron efflux from cells (19). multiple mechanisms have been proposed to explain ceruloplasmin antioxidant activity, including scavenging of superoxide and other reactive oxygen species (20), and inhibiting the fenton reaction by conversion of fe2+ to fe3+ (cp is also called "ferroxidase") (21,22). the latter mechanism is backed by a considerable body of evidence, but the ability of cp to block cu2+mediated lipid oxidation suggests that alternate antioxidant mechanisms must also pertain (23). there is evidence that cp as an antioxidant blocks protein (24) and dna damage (25), and that it gives protection against free radical-initiated cell injury and loss (26). the source of circulating cp has been almost exclusively assigned to cp secreted by hepatocytes (27). human monocytic cells have also been shown to produce and secrete their own cp on activation (28). human peripheral blood lymphocytes express the transcripts for both cp molecular isoforms. during infection and inflammation characterized by active proliferation of circulating lymphocytes, cp concentration in serum increases, suggesting that the expression of the cp gene represents an j bagh college dentistry vol. 26(3), september 2014 assessment of serum oral diagnosis 56 essential part of host response to immunological stress (29). the significant increase of serum cp level in this study may represent a compensatory antioxidant defense system to counteract oxidative stress. antioxidants are present in all body fluids including saliva. saliva may constitute a first line of defense against oxidative stress and has protective effects against microorganisms, toxins and oxidants (2,30). the use of saliva as a diagnostic tool presents many advantages: it is easy to collect, by a noninvasive technique which can be performed at home; no special equipment is needed for collection. from children to seniors, saliva can be used as a diagnostic fluid because collection of this fluid is associated with fewer compliance problems compared with blood collection (31). in spite of this, levels of certain markers in saliva are not always a reliable reflection of the levels of these markers in serum. the transfer of serum components which are not part of the normal salivary constituents into saliva is related to the physicochemical characteristics of these molecules. salivary composition can be influenced by the method of collection and the degree of stimulation of salivary flow. furthermore, salivary proteolytic enzymes can affect the stability of certain diagnostic markers (32). blood still remains the best body fluid for evaluation of many biomarkers reflecting systemic processes and substitution should be used with caution (31). the facts mentioned may reflect what the present study showed that there was no significant correlation between serum and saliva cp levels in olp patients group. therefore, saliva is not always a reliable indicator of the internal environment of the body. on the extent of our knowledge, there were no previous studies dealing with cp in both serum and saliva of olp patients. references 1birben e, sahiner um, sackesen c, erzurum s, kalayci o. oxidative stress & antioxidant defense. world allergy organ j 2012; 5: 9-19 2hegde am, rai k, vasantha padmanabhan. total antioxidant capacity of saliva and its relation with early childhood caries and rampant caries. journal clin pediatric dent 2009; 33(3): 231-4. 3stocks j, gutteridge jmc, sharp rj, dormandy tl. clinical science and molecular medicine 1974; 47: 223-33 (cited by: gutteridge jmc. antioxidant properties of caeruloplasmin towards ironand copper-dependent oxygen radical formation. febs letters. 1983; 157 (1): 37-40). 4gutteridge jmc, stocks j. caeruloplasmin: physiological and pathological perspectives. crit reviews in clinical laboratory sciences 1981; 14, 257329. 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(cited by: hiremath sks, kale ad, charantimath s. oral lichenoid lesions: clinico-pathological mimicry and its diagnostic implications. indian j dental res 2011; 22 (6): 827-834). 12menden ee, bioano jm, murthy l, petering hg. modification of a phenylene dianine oxidase method to permit non automated caeruloplasmin determination in batches rat serum or plasma microsamples. anal lett 1977; 10: 197-204 13ismail sb, kumar sks, zain rb. oral lichen planus and lichenoid reaction: aetiopathogenesis, diagnosis, management and malignant transformation. j oral sci 2007; 49(2): 89-106. 14anshumalee n, shashikanth mc, sharma s. oxidative stress and oral lichen planus: a possible association. cusp 2007; 4(2): 31–4. (cited by: aly dg, shahin r. oxidative stress in lichen planus. acta dermatoven alpina panonica et adriat 2010; 19(1): 3-1.1 15fridovich i. superoxide anion radical (o2-), superoxide dismutases, and related matters. j biological chem 1997; 272(30): 18515-7. 16karlsson a, dahlgren c. assembly and activation of the neutrophil nadph oxidase in granule membranes. antioxidants & redox signal 2002; 4: 49-60. 17duval c, cantero a v, auge n, mabile l, thiers j c, negre-salvayre a, salvayre r. proliferation and wound healing of vascular cells trigger the generation of extracellular reactive oxygen species and ldl oxidation. free radical biology and medicine 2003; 35:1589-98. 18decker h, van holde ke. oxygen and the evolution of life. berlin heidelberg: springer; 2011 j bagh college dentistry vol. 26(3), september 2014 assessment of serum oral diagnosis 57 19jeong sy, david s. age-related changes in iron homeostasis and cell death in the cerebellum of ceruloplasmin-deficient mice. j neurosci 2006; 26(38): 9810-9. 20goldstein im, kaplan hb, edelson hs, and weissmann g. ceruloplasmin: a scavenger of superoxide anion radicals. j biological chemistry 1979; 254: 4040-5. 21samokyszyn vm, miller dm, reif dw, and aust sd. inhibition of superoxide and ferritin-dependent lipid peroxidation by ceruloplasmin. j biol chem 1989; 264: 21-26. (cited by: ehrenwald e, chisolm gm, fox pl. intact human ceruloplasmin oxidatively modifies low density lipoprotein. j clinical investigation 1994; 93: 1493-501) 22gutteridge jm. inhibition of the fenton reaction by the protein caeruloplasmin and other copper complexes: assessment of ferroxidase and radical scavenging activities. chem biol interact 1985; 56:113-20. 23gutteridge jmc. antioxidant properties of caeruloplasmin towards ironand copper-dependent oxygen radical formation. fed eur biochem soc lett 1983; 157: 37-40. 24krsek-staples ja, webster ro. ceruloplasmin inhibits carbonyl formation in endogenous cell proteins. free radical biol & med 1993; 14: 115-25. 25gutteridge jmc, richmond r, halliwell b. oxygen free radicals and lipid peroxidation: inhibition by the protein caeruloplasmin. fed eur biochem soc lett 1980; 112: 269-72. 26lovstad ra. the protective action of ceruloplasmin on copper ion stimulated lysis of rat erythrocytes. int j biochem 1982; 14: 585-9. 27banha j, marques l, oliveira r, martins m, paixão e, pereira d, malhó r, penque d, costa l. ceruloplasmin expression by human peripheral blood lymphocytes: a new link between immunity and iron metabolism. free radical biology and medicine 2008; 44: 483–92 28mazumder b, mukhopadhyay ck, prok a, cathcart m k, fox p l. induction of ceruloplasmin synthesis by ifn-gamma in human monocytic cells. j immunology 1997; 159:1938–44. 29hellman ne, gitlin jd. ceruloplasmin metabolism and function. annu rev nutr 2002; 22: 439–58. (cited by: banha j, marques l, oliveira r, martins m, paixão e, pereira d, malhó r, penque d, costa l. ceruloplasmin expression by human peripheral blood lymphocytes: a new link between immunity and iron metabolism. free radical biology and medicine 2008; 44: 483–92) 30nagler rm, klein i, zarzhevsky n, drigues n, rezinck a. characterization of the differentiated antioxidant profile of human saliva. free radical biology and medicine 2002; 32: 268-77. 31williamson s, munro c, pickler r, grap mj, elswick jr rk. comparison of biomarkers in blood and saliva in healthy adults. nursing research and practice. 2012; article id 246178. 32kaufman e, lamster ib. the diagnostic applications of saliva-a review. critical reviews in oral biol and med 2002; 13: 197-212. 14. fatma f.doc j bagh college dentistry vol. 25(1), march 2013 oral manifestation oral diagnosis 82 oral manifestation biochemical and iga analysis of saliva in hyperthyroid (grave’s disease) patients (comparative study) fatma a. abdulkareem al-naif, b.d.s. (1) fawaz d. al-aswad, b.d.s., m.sc., ph.d. (2) abstract background: hyperthyroidism occurs due to over production of thyroid hormones, one types of hyperthyroidism was graves, disease. hyperthyroidism is characterized by high level of serum thyroxin, triiodothyronine and low level of thyroid stimulated hormones. material and methods: fifty two hyperthyroid patients, thirty patients under treatment with carbimazole and other twenty two patients under treatment with radioactive iodine, and sixty healthy control group. the average salivary flow rate was calculated as ml/5mint.the concentration of calcium, potassium, and total protein were determined in the salivary supernatant sample. this is done through different biochemical tests. determination of salivary iga is done by eliza. results: the most prevalence oral manifestation was dry mouth; there were highly significant differences in salivary flow rate between the two studied groups. there were differences in concentration of total salivary protein and salivary iga between the two studied groups although statistically non-significance. however there a significant differences in calcium concentration between the two studied groups, also there was a sequential decrease in potassium concentration between the two studied groups and control group. conclusions: those type of patients need dental evaluation especially those who are taking radioactive iodine. keywords: hyperthyroidism, graves, disease, radioactive iodine, carbimazole. (j bagh coll dentistry 2013; 25(1):8286). introduction hyperthyroidism is characterized by high level of serum thyroxin, triiodothyronine and low level of thyroid stimulated hormones. the main causes of hyperthyroidism are graves’s disease, toxic multinodular goiter and toxic adenoma. about 20 times more women than men have hyperthyroidism. (1) the oral manifestation in patients with hyperthyroidism is due to the disease process, and those are associated with drug intake used to treat hyperthyroidism. oral manifestation due to the disease process include: accelerated dental eruption in children , maxillary or mandibular osteoporosis, enlargement of extra glandular tissue (mainly in lateral posterior tongue) increase susceptibility to caries , periodontal disease , burning mouth syndrome and development of connective tissue diseases like sjogren’s syndrome or systemic lupus erythematosus.(2,3) on the other hand oral manifestation that were associated with drug intake used to treat hyperthyroidism include : xerostmia , taste changes , infection , increase susceptibility to caries , facial nerve involvement , stomatitis , sialoadenitis ,candidiasis , neoplasia , salivary gland neoplasia.(4,5,6) (1) master student, department of oral medicine, college of dentistry, university of baghdad. (2) assistant professor, department of oral medicine, college of dentistry, university of baghdad. also there were changes in the composition of whole stimulated saliva that the concentration of urate and potassium ions were increased, while concentration of total protein, calcium ions and lactate dehydrogenase activity significantly decreased. (7) other researchers illustrated excess salivation and swollen of salivary glands. (5) this study was designed to: 1 –determine the prevalence of oral manifestation in hyperthyroid, patients treated with antithyroid drugs (carbimazole and radioactive iodine). 2 – determine the level of total salivary protein, concentration of salivary calcium and potassium in hyperthyroid patients treated with antithyroid drugs (carbimazole and radioactive iodine) and to compare with clinically healthy individuals. 3 – investigate the (iga) changes in saliva of hyperthyroid patients receiving antithyroid drugs (carbimazole and radioactive iodine) and compare with clinically healthy individuals. materials and methods a comparative study was performed in alyarmuk teaching hospital in baghdad. the study samples consist of fifty two hyperthyroid patients, thirty patients under treatment with carbimazole (methimazole) and other twenty two patients under treatment with radioactive iodine, and sixty healthy control group with no sign and symptom of any systemic disease. j bagh college dentistry vol. 25(1), march 2013 oral manifestation oral diagnosis 83 all the patients examined by a single examiner, under standardized conditions; the oral cavity examined in an artificial light using mouth mirror according to who (1987). the oral manifestations were classified according to: a-dry mouth: was diagnosed according to the anamenesis below: does your mouth feel dry? do you experience any difficulties in chewing dry foods? do you experience any difficulties in swallowing dry foods? are you aware of any recent increase in the frequency of liquid intake? (8) b-burning mouth sensation: the diagnostic criteria for burning mouth syndrome in this study was :pain in the mouth present daily and persisting for most of the day, oral mucosa is of normal appearance, local and systemic diseases have been exclude.(9) c-dysguesia (taste alteration): taste alteration can be diagnosed in this study according to the criteria taken from the european organization for research and treatment of cancer (eortc): have you had problems with your sense of taste? and did food and drink taste different from usual?(10) saliva collection was done according to the wu-wang procedure(11), to avoid circadian variation the sample was collected between 9 a.m and 1.00 p.m. all samples were centrifuged for 10 min. at 3000 rpm .then supernatants stored at -70 c freezers until analysed. (12) then biochemical analysis was performed on salivary supernatants, so the concentrations of salivary calcium, potassium, and total salivary protein were determined. this is done through biochemical tests: a-determination of salivary minerals {calcium , and potassium. }: this was done by atomic absorption spectrophotometer (aas) using standardized (stock standard for k+1 1mg/l,and -stock standard for ca+2 1mg/l) by air acetylene. b-determination of total salivary protein. using total protein kit (spinreact) by spectrophotometer at 598nm. after that the average salivary flow rate was obtained from the total volume collected in the study time, (13) and salivary flow rate calculated as ml/5mint. finally the determination of salivary iga is done by enzyme link immunosorbent assay, using demeditec secretory iga elisa (dexk276) kit. statistical analysis levene test for testing the homogeneity of variances for equality of variances, one-way anova for equality of means with (lsd) least significant difference, fisher's exact test, contingency coefficients test, and odds ratio coefficient. results table (1) shows the distribution of oral manifestation according to the type of treatment, with all types of manifestation studied ,the difference was non-significance. whereas odds ratio criteria illustrated extremely difference between oral manifestation in those of treatment n (carbimazole) compared with those of treatment r (radioactive iodine) with proportion of 10:43, n:r, in dry mouth,10:13 in dysguesia, and 10:42 in burning mouth respectively. in table (2) another statistical methodology was used but in this instances all type of treatment were compared against the control groups, with the mean, standard deviation, standard errors, (95%) confidence interval for population mean of score values, minimum and maximum values. table (3) showed the results of multiple comparisons by lsd method which represented statistically differences at p<0.01 between study neomercazole and study radioactive iodine at the parameter salivary flow rate and at p<0.05 between the preceding of the study groups at the parameter calcium as well as at p<0.01 between the two study groups and control group and with a non significant at p>0.05 were recorded with the leftover. discussion oral manifestations dry mouth considered the most prevalence oral manifestation seen in this study, female is more prevalence among hyperthyroid patients and so dry mouth seen more in female. this explained by the fact that hormonal changes in female lead to several oral alterations including xerostomia and burning mouth syndrome.(14) also, dry mouth seen more in hyperthyroid patients treated with radioactive iodine than those treated with carbimazole. on the same line khonle,(15) stated that one of the possible complications of rai therapy was dry mouth. while ford(7) suggested that after rai therapy there was an increase in salivary flow rate. dysguesia was the second oral manifestation in this study, again dysguesia was seen more in female than male due to the fact that female is more prevalence among hyperthyroid patients than male , dysguesia seen among hyperthyroid patients treated with carbimazole rather than those j bagh college dentistry vol. 25(1), march 2013 oral manifestation oral diagnosis 84 treated with radioactive iodine. this could be explained by the fact that the anti-thyroid agent (carbimazole) had adverse effect either by interfering with chemical composition or flow of saliva or by affecting taste receptor function or signal transduction that cause taste alteration. (16) burning mouth was least oral manifestation that seen in this study, it seen more in female than male owing to the fact that the female is more prevalence among hyperthyroid patient than male. (17) salivary flow rate this study concluded that hyperthyroid patients treated with radioactive iodine showed decrease in salivary flow rate in compared with control, this in line with wolfram,(18) while ford(7) suggested that after rai therapy there will be an increase in salivary flow rate. in the other hand, this study revealed that hyperthyroid patients treated with carbimazole shows increase in salivary flow rate in compared with control, this is not in line with a study done by scully and sebastian,(17) they stated that antithyroid drug (carbimazole) may cause salivary gland swelling as a side effect of prolong used. salivary iga hyperthyroid patients treated with radioactive iodine showed increase in the concentration of salivary iga than those treated with carbimazole, that,s to say there is improvement in salivary iga concentration after treatment with rai, this result is in line with study done by ford done on hyperthyroid patients after administration of rai.(7) total salivary protein this study showed low salivary total protein among hyperthyroid patients treated with radioactive iodine, than hyperthyroid patients treated with carbimazole. this not in line with ford(7) whom suggested that after rai therapy there is improvement in the concentration of total salivary protein.(7) this could be explained by the fact that total salivary protein decrease among hyperthyroid patients before treatment.(7) recently al-rubbaey(18) stated that total salivary protein increase among hyperthyroid patients, in this study carbimazole treated patients shows increase in total salivary protein than radioactive iodine treated patients this may explained by the fact that due to improvement in their toxic state. salivary calcium the present study showed slight higher concentration of salivary calcium in hyperthyroid patients receiving carbimazole than those receiving rai.this in line with fisher(19) who’s declared that hyperthyroidism consider as a cause of hypocalcaemia. in the other hand ford(7) found a decrease in salivary calcium among hyperthyroid patients. salivary potassium there was increase in salivary potassium concentration in the two studied groups in compared with control. the same as with that seen by ford (7) among group of hyperthyroid patients.(7)however, benign thyroid disease such as hyperthyroidism can influence the composition and flow of saliva, although the exact mechanism is unknown (7, 20). references 1. nygard b. hyperthyroidism (primary). department of endocrinology. clin evid (online) 2010; 19: 611. 2. d’arbonneau f, ansart s, le berre r, dueymes m, youinou p, pennec yl. thyroid dysfunction in primary sjogren’s syndrome:along term follow up study. arthritis rheum 2003; 15(49): 804-9. 3. carlos lf, jimenez soriano y, sarrion perez mg. dental management of patient with endocrine disorderes. j clin exp dent 2010; 2: 196-203. 4. susan j mandel, louis mandel. radioactive iodine and salivary glands. thyroid 2003; 13: 265-71. 5. ionescu o, sonnet e, roudaut n, predine-hug f, kerlan v. oral manifestation of endocrine dysfunction. ann endocrinol (paris) 2004; 85: 459-85. 6. gurgul e, sowinski j. primary hyperthyroidismdiagnosis and treatment. indication and contration for radioiodine therapy. nucl med rev cent east eur 2011; 14: 29-32. 7. ford h, johnson l, purdie g, feek c. effects of hyperthyroidism and radioactive iodine given to ablate the thyroid on the composition of whole stimulated saliva. clin endocrinol 1997; 46: 189-93. 8. azambuja s, paulo henrique, reinhilde jacobs, olivia nackaerts, olivia nackaerts, izabel regina fischer, fernando henrique, samuel jorge, sérgio aparecido, maitê barroso da, ana lúcia. clinical diagnosis of hypo-salivation in hospitalized patients. j appl oral sci 2012; 20:157-61. 9. klasser g, dena j, fischer joel b, epstein. burning mouth syndrome: recognition, understanding, and management. oral maxillofacial surg clin 2008; 20: 255–271. 10. zabernigg a, eva-maria gamper, johannes m giesinger, gerhard rumpold, georg kemmler, klaus gattringer, barbara sperner-unterweger, bernhard holzner. taste alterations in cancer patients receiving chemotherapy: a neglected side effect? the oncologist 2010; 15: 913-920. 11. wu-wang cy, patel m feng j, milles m, wang sl. decreased levels of salivary prostaglandin e2 and epidermal growth factor in recurrent aphthous stomatitis. arch oral biol 1995; 40:1093-8. 12. jafarzadeh a, mostafa sadeghi, gholamreza asadi karam, reza vazirinejad. salivary iga and ige levels in healthy subjects: relation to age and gender. immun braz oral res 2010; 24: 21-7. 13. thaweboon s, boonyanit thaweboon, siriruk nakornchai, sukritta jitmaitree. salivary secretory iga, ph, flow rates mutans streptococci and candida j bagh college dentistry vol. 25(1), march 2013 oral manifestation oral diagnosis 85 in children with rampant caries. southeast asian j trop med public health 2008; 39: 893-9. 14. mutneja, pankaj dhawn, anudeep raina, gaurav sharman. menopause and the oral cavity. indian j endocrinol and metab 2012; 4: 548-51. 15. kohnle d. radioactive iodine treatment. nucleus medical art university of southern california. inc. 2009, doctor of usc. 16. scully s, sebastian jvb. adverse drug reaction in the oraofacial region. crit rev oral biol med 2004; 15: 221-40. 17. wolfram rm, palumbo b, chehne f, palumbo r, budinsky ac, sinzinger h. (iso) prostaglandins in saliva indicate oxidation injury after radioactive iodine therapy. rev esp med nucl 2004; 23: 183-8. 18. al-rubbaey a. oral health status and dental treatment needs in relation to salivary constitutes and parameters among a group of patients with thyroid dysfunction. a thesis, college of dentistry, university of baghdad, 2009. 19. fisher da. a text of the quest diagnostic manual endocrinology, test selection and interpretation.4th ed. 2007. p.228. 20. newkirk ka, matthew d, ringel leonard wartofsky, kenneth d burman. the role of radioactive iodine in salivary gland dysfunction. ear nose and throat j 2012; 18: 358. table 1: distribution of the oral manifestations at the two different of the studied treatments groups with comparison's significant oral manifestation treatment freq. & percent absent present total c.s. (*) p-value (dry mouth) neomercazol e freq. 13 17 30 fept p=0.0.052 ns cc=0.450 p=0.056 ns odds ratio (1 : 3.441) (n : r) % within groups 43.3% 56.7% 100% radioactive iodine freq. 4 18 22 % within groups 18.2% 81.8% 100% total freq. 17 35 52 % within groups 32.7% 67.3% 100% (dysguesia) neomercazol e freq. 21 9 30 fept p=0.0.425 ns cc=0.067 p=0.629 ns odds ratio (1 : 1.333) (n : r) % within groups 70% 30% 100% radioactive iodine freq. 14 8 22 % within groups 63.6% 36.4% 100% total freq. 35 17 52 % within groups 67.3% 32.7% 100% (burning mouth) neomercazol e freq. 25 5 30 fept p=0.0.183 ns cc=0.184 p=0.176 ns odds ratio (1 : 4.202) (r : n) % within groups 83.3% 16.7% 100% radioactive iodine freq. 21 1 22 % within groups 95.5% 4.5% 100% total freq. 46 6 52 % within groups 88.5% 11.5% 100% (*) ns : non significant at p> 0.05 j bagh college dentistry vol. 25(1), march 2013 oral manifestation oral diagnosis 86 table 2: descriptive statistics for the studied parameters at the two different of the studied treatments groups parameters treatment no. mean std. d. std. error 95% c. i. for mean min. max. l.b. u.b. sal. flow rate ml / 5 min. neomercazole 30 1.25 0.63 0.11 1.02 1.48 0.25 2.5 radioactive iodine 22 0.78 0.31 0.07 0.65 0.92 0.25 1.5 control 16 1.00 0.66 0.17 0.65 1.35 0.25 2.5 iga mg/ml neomercazole 30 159.25 49.97 9.12 140.59 177.90 48.0 265.5 radioactive iodine 22 167.90 49.81 10.62 145.82 189.99 47.1 242.3 control 16 166.56 44.52 11.13 142.84 190.28 47.8 229.1 calcium mg / ml neomercazole 30 5.55 0.82 0.15 5.25 5.86 4.2 7.2 radioactive iodine 22 4.99 0.84 0.18 4.62 5.36 3.9 6.4 control 16 3.93 0.52 0.13 3.66 4.21 3.1 4.6 potassium µmol / l neomercazole 30 9.92 2.78 0.51 8.88 10.95 6.2 16 radioactive iodine 22 9.66 3.40 0.72 8.15 11.17 4.6 17.6 control 16 8.45 2.47 0.62 7.14 9.76 5.6 12.6 total protein gm / l neomercazole 30 0.72 0.16 0.03 0.65 0.78 0.36 0.9 radioactive iodine 22 0.70 0.16 0.03 0.63 0.77 0.47 0.95 control 16 0.74 0.16 0.04 0.65 0.83 0.41 0.95 table 3: multiple comparison (lsd) among all pairs of different responding of the studied parameters in the studied groups dependent variable (i) groups (j) groups sig. c.s. sal. flow rate ml / 5 min. study neomercazole study radioactive iodine 0.004 hs control 0.151 ns study radioactive iodine control 0.241 ns iga mg/ml study neomercazole study radioactive iodine 0.529 ns control 0.629 ns study radioactive iodine control 0.933 ns calcium mg / ml study neomercazole study radioactive iodine 0.011 s control 0.000 hs study radioactive iodine control 0.000 hs potassium µmol / l study neomercazole study radioactive iodine 0.755 ns control 0.111 ns study radioactive iodine control 0.213 ns total protein gm / l study neomercazole study radioactive iodine 0.707 ns control 0.609 ns study radioactive iodine control 0.423 ns dropbox 5 zahraa 23-28.pdf simplify your life j bagh college dentistry vol. 33(4), december 2021 assessment of coating 25 assessment of coating zirconium implant material with nanoparticles of faujasite ahmed ali mohammed (1), thekra ismael hamad (2) https://doi.org/10.26477/jbcd.v33i4.3016 abstract aim: to evaluate the wettability and microhardness of zirconium (zro2) dental material when coated with different concentrations of faujasite. materials and methods: 30 circular disks produced from zro2, then each group is classified into 10 control groups, 10 coated groups with 3% faujasite, and 10 coated groups with 7% faujasite by electro-spun tool to study variable properties in hardness and water contact angle of implant materials. results: this study stated the high hardness in 7% of faujasite concentration for zro2, in addition, the contact angle decreased gradually until reach 0 ᵒ in 7% concentration of faujasite with zro2 conclusion: water contact angle (wca) declined till disappeared in (7% wt.) of faujasite coated with the zro2 group, also in the same group the microhardness became high compared with other groups due to alteration in surface morphology of substrate, and properties of coated material. keywords: electrospinning, microhardness, wettability, circular disk, polyvinylpyrrolidone (pvp), water contact angle. (received: 28/9/2021, accepted: 30/10/2021) introduction titanium was used as a dental material for several decades and considered as standardization of dental implants but because of disadvantages such as galvanic corrosion and cellular sensitivity associated with the saliva of humans (1), it was an alternative with ceramic dental material such as zirconia(zircon strong transition metal, grey-white, and lustrous named zirconium), it was the oxide form of zircon (2). 2in 1824 jones jakob berzelius was the first to produce zirconium in the form of impure. in dentistry, it was utilized to fabricate esthetic orthodontic brackets, crown/bridge, endodontic posts, implant abutments for rehabilitation of partial and complete arches, and restorations. faujasite was classified into y had a si/al ratio of more than 1.5, and x had a si/al from (1_1.5). zeolitic materials were characterized mainly by their ion exchange and adsorption capacities. in addition, they can be produced in the laboratory using low-, cost raw materials. these materials have been widely used as adsorbents, molecular sieves, and ion exchangers in the treatment of wastewater, air purifiers, catalysts, and catalyst support (3). the hardest of ceramic was (1) phd student, al-diwaniya directorate, ministry of health baghdad, iraq. (2) professor. department of prosthodontic, college of dentistry, university of baghdad, baghdad, iraq corresponding email, drtooth80@hotmail.com a zirconia. it was widely produced in a monolithic phase for many clinical usages, was known as yttria-stabilized tetragonal zirconia polycrystal (ytzp). different types of y-tzp found can be based on heat treatment, sintering, dopants, and additives (4). absence of toxicity and good mechanical properties of y-tzp was forced to choose it in dental usage, though it had one problem about matching it with natural teeth to improve esthetic (5). electrospinning was one way to produce filaments (ultrafine fiber) from many types of materials like composite, polymer, and ceramic. the machine was composed of three parts, conductive collector, syringe with metallic needle, and voltage power supply. this process was divided into various techniques such as bubble electrospinning, siroelectrospinning, vibration electrospinning, and magneto-electrospinning (6). various devices were utilized to analyze surface texture and surface properties such as water contact angle (wca) and microhardness by the x-ray diffraction and energy diffraction spectroscopy (7). materials and methods https://doi.org/10.26477/jbcd.v33i4.3016 j bagh college dentistry vol. 33(4), december 2021 assessment of coating 26 partially sintered zirconia from vita was supplied in block disc with a dimension of 98.4 mm in diameter and 12 mm in height, the white shade (a1), was cut into small circular discs (10 mm diameter and 1 mm thickness) as shown in figure (1) the substrates prepared with exo-cad dental cad software. to prepare zirconia samples, fractional sintered zirconia block disc was cut according to the selected measurements utilizing a dental computerized three-axis milling system, computeraided design /computer-aided manufacturing (cad/cam) imes-icore, germany), substrates sintered in sintering heater of imes-icore up to 1650 c̊, according to manufacture instruction. then, substrates were cleaned ultrasonically in ethanol for half an hour and then put aside in the air before coating (8). polyvinylpyrrolidone (pvp) (mw: 40,000) was produced by alpha chemical (made in india), pvp, and distilled water was considered as a solvent for the faujasite manufactured by china with a particle size of about 286.7 as shown in the figure (2) and measurements of parameters device mentioned in table (1). the sample of zirconia coated with faujasite by using the electrospun technique is shown below figure 1 zirconium disk by using an electrospinning machine (made in the usa), filaments was formed after mixing 40% wt. of pvp with concertation of faujasite (3% & 7%), and addition d.w. to become the mixture solution 5 gm for each percentage, the parameters of the machine were 20 k.v. of the voltage supply, flow rate (1.5 ml/h.), and the distance (13 cm) between detector with samples and head of needle syringe found in the electrospun machine after the filaments were formed, all samples were kept in room temperature to evaporate the solvent (9). figure 2 particle size analyzer of faujasite table 1 measurement parameter of particle size analyzer device temperature = 25.0 deg. c runs completed = 3 liquid = water burn duration =00:00:30 viscosity = 0.890 cp total elapsed time = 00:01:30 ref. index fluid = 1.330 average count rate =450.1 keps angle 90.00 ref. index real = 1.590 wavelength 660.00 ref. index image =0.000 baseline auto (slope analysis) dust filter setting = 30.00 results characterization nanofibers were characterized by the energy diffraction spectroscopy (eds) and x-ray diffraction (xrd) in order to evaluate water contact angle and microhardness for various percentage coating of faujasite and compared with uncoating group. the energy diffraction spectroscopy (eds) it was a method to determine element composition material which formed samples and then analyzed by forming peaks for each ingredient and examination by energy dispersive x-ray spectroscopy (made in netherland) j bagh college dentistry vol. 33(4), december 2021 assessment of coating 27 figure 3 edx of uncoated zirconia figure 4 edx of zirconia coated 3% faujasite figure 5 edx of zirconia coated 7% faujasite . x-ray diffraction (xrd) an automated x-ray diffractometer was employed for phase analysis by using cu kα radiation (λ=1.5406 aᵒ), xrd-6000, shimadzu (japan) the operation was done at 30 ma and 40 kv. ambient laboratory temperature using 10s/angular step (1 angular step = 0.02º) was used for taken diffraction patterns, depending on the joint committee on powder diffraction standards (jcpds) of the international center for the diffraction data the peak indexing was carried out. figure 6 xrd of uncoated, coated 3% faujasite(f) and coated 7% faujasite (f) zirconia, groups wettability analysis in the department of chemical engineering / university of technology, iraq. the measurements of wettability were done by goniometer cam 110, made in germany, to survey the effect of different percentages of faujasite coating with zro2 and evaluate wettability phenomena on selected disks 30 seconds was needed to capture an image after applying a drop of liquid on an intended surface, the procedure occurred at an ambient temperature. microhardness test digital vickers micro-hardness tester buehler micrometer 5103, usa, was used to record the micro-hardness of the zro2 disks coated by faujasite with 3% and 7%, and uncoated disks according to (astm e92-82, 1997), for 5 seconds 9.8g load was applied to the surface of the disk by using vickers indenter that joins optical microscopy. an average of 3 different readings was measured from the ten zro2 specimens for each selected concentration to compare between the control and coating groups. the interpretations edx for each percentage of faujasite (3% and 7%) in respectively were shown j bagh college dentistry vol. 33(4), december 2021 assessment of coating 28 in fig (4), (5, utilized in the coating of zirconia and compared it with the control group as seen in fig (3). also, tables (2), (3), and (4) showed the quantities results for all groups control, coated 3%, and coated 7% of faujasite in respectively. table 2 quantitive results of uncoated group table 3 quantitive results of zirconia coated 3% faujasite table 4 quantitive results of zirconia coated 7% faujasite phase analysis was applied to the samples before coating surface structuring, and after coating technique for 3 and 7 % concentration of faujasite besides the control disks as seen in fig. (6) and basic data in the table (5) showed the three strongest peaks in each group which interpreted amount of changing occurred by the effect of treatment with faujasite that included peak number, 2 theta degrees, amount of diffraction, intensity, and full width at a high maximum of xrd profile table 5 basic data of xrd for study groups uncoated zro2 peaks no. 2 theta (degree) diffraction (angstrom) intensity(i/i1) fwhm 3 30.1423 2.96248 100 0.5726 8 50.1979 1.81596 60 0.6307 5 34.7594 2.57882 29 0.3893 3% faujasite coated zro2 2 30.2361 2.95351 100 0.6756 5 50.3643 1.81035 54 0.6924 3 34.9005 2.56871 27 0.525 7% faujasite coated zro2 2 29.927 2.9833 100 0.8327 7 50.0502 1.82097 70 0.9082 8 59.2329 1.55871 43 1.0167 the mean water contact angle in zro2 with 7% faujasite was zero degree, and for the zro2 with 3% faujasite was 21.46ᵒ but for control, zro2 was 77.72ᵒ and descriptive statistics of water contact angle test of the 3 groups were summarized in table (6). the table shows the lowest water contact in group zro2 7% faujasite (f) (0)ᵒ and the highest value of water contact in the control group of zro2 (78.65ᵒ). table 6 descriptive statistic wca for zirconia groups groups no. mean std min max zro2 c 10 77.72 0.579 76.65 78.65 zro2 3% f 10 21.461 1.049 20.121 22.876 zro2 7% f 10 zero zero zero zero statistically, the f-test of the one-way anova test showed a non-significance difference in the water contact angle among the 3 groups, because of p> .05 at three degrees of freedom, as shown in table (7). table 7 one-way anova test of wca source of variance df ss ms f p between groups 1 1586 1586 1.969 0.233 n.s within groups 4 3222.3 805.575 total 5 4808.301 elt line int k kr w% a% zaf c ka 73.5 0.1726 0.0734 22.25 29.34 0.3298 o ka 512.1 0.5986 0.2545 57.49 56.93 0.4426 na ka 434.1 0.1938 0.0824 17.86 12.30 0.4615 mg ka 30.7 0.0128 0.0054 1.11 0.72 0.4908 si ka 28.5 0.0122 0.0052 0.73 0.41 0.7111 p ka 20.5 0.0100 0.0042 0.56 0.29 0.7525 1.0000 0.4251 100.00 100.00 elt line int k kr w% a% zaf c ka 41.5 0.1049 0.0388 15.87 21.50 0.2442 o ka 636.0 0.6807 0.2515 62.48 63.56 0.4025 na ka 483.6 0.1700 0.0628 18.87 13.36 0.3328 al ka 38.2 0.0115 0.0042 0.89 0.54 0.4749 si ka 47.4 0.0145 0.0054 0.88 0.51 0.6067 p ka 54.3 0.0184 0.0068 1.00 0.53 0.6776 1.0000 0.3694 100.00 100.00 elt line nit k kr w% a% zaf c ka 5.2 0.0114 0.0066 3.56 7.10 0.1850 0 ka 314.4 0.2937 0.1696 49.33 73.78 0.3438 k ka 285.1 0. 1147 0.0662 7.61 4.66 0.8707 zn ka 351.8 0.5801 0.3350 39.50 14.46 0.8480 1.0000 0.5774 100.00 100.00 j bagh college dentistry vol. 33(4), december 2021 assessment of coating 29 three readings were obtained from each of the thirty specimens (ten discs for each group) by using the vickers microhardness tester by applying 9.8 g load for 5-second descriptive statistics for microhardness was seen in the table (8). the table shows the lowest mean value for group control (c) of zro2 was 1275.38 h.v. and 1683.65 h.v. the highest mean was in group zro2 7 % faujasite (f). table 8 descriptive statistic of vickers microhardness test for zirconia groups groups no. mean std min max zro2 c 10 1275.38 43.446 1190 1349 zro2 3% f 10 1646.4 87.398 1521 1763 zro2 7% f 10 1683.65 69.824 1587 1790 anova test seen in table (9) revealed that there was a highly significant difference among the groups p≤ .01 at 3 degrees of freedom. table 9 one-way anova test for vickers microhardness of zirconia groups source of variation df ss ms f p between groups 2 6.290 0.645 14.106 0.000 h.s residual 27 62.216 4.48 total 29 2.507 discussion in xrd analysis between study groups of zro2 as seen in fig. (7) and table (5) especially at the intensity 100 (i/i1) showed a high difference in the full width at a high maximum of xrd profile (fwhm) which was responsible to describe surface and various material properties like plastic deformation, mechanical properties, and changed in microhardness, many surveys stated fwhm was an accurate signal of the surface work hardening compared with another microhardness testing. in this study, the results showed the (fwhm) at some intensity increased from 0.57 degrees in control groups and become in study groups coating 3% f 0.67 degree till reached to 0.83 degrees with a group of 7% f coated of zro2 (10). in table (4) compared with table (2), and (3) the edx interpreted the present zinc clearly with study groups coated with 7% faujasite which was responsible to modify the mechanical and wettability properties, the addition of zinc to the ti6al-4v result in low the modulus of elasticity and enhancement of microhardness, also zinc (zn) particles cause improvement in hydrophilicity and biocompatibility through cell proliferation and adhesion (11). due to the foundation of oxygen, sodium, silicon, and aluminum in selected samples, there appeared in their low xps resolution spectra. faujasite has interpreted the crystallinity via eds, and ftir analysis (12). wca was decreased gradually with increased concentration of faujasite for dental implant materials until reached wca = 0ᵒ with coating 7% concentration of faujasite to zro2, interpreted increasing hydrophilicity of materials when coated with faujasite to improve dental implant properties, was significant with water absorption capability, it was a critical parameter to determine the liquid uptake from the media, therefore, it can be considered as a significant indicator to evaluate the suitability of biomaterial for tissue engineering usages (13) the θ angle for each scaffold was observed when a drop of water placed on the sample, for plga (poly lactic-co-glycolic acid/scaffold), θ = 123.8° ± 5°, it shows that the structure of pure polymeric scaffold was hydrophobic for plga/zeolite 3 (wt.%), θ was declined to 101.83° ± 6°, while nano-scaffold was stayed hydrophobic. water contact angles for plga/zeolite 7 (wt.%) and plga/zeolite 10 (wt.%) were 94.64° ± 6° and 82.08° ± 4°, in sequence. this showed that adding more zeolite to plga made it more hydrophilic. these results observed that nanoparticle zeolite powder utilized in the composite had a high tendency to water wettability (14). in zirconia groups showed enhancement in microhardness values with coating material due to increase ingrain particle size and surface roughness caused bonding between coating materials and substrate of zirconia (15). other investigations may be demonstrated this variation by examination and study increase the microhardness associated with magnifying grain size and diminishing surface roughness due to the load applied diminished upon micro-crack adjacent to the penetration area of diamond tool (16). j bagh college dentistry vol. 33(4), december 2021 assessment of coating 30 conclusion this study clarified the microhardness and water contact angle (wca) improved in zro2 groups by enhancement the concentration of nanoparticles of faujasite to develop dental implant material and restriction of implant failure in the future with advanced coated techniques. references 1. safi in, hussein bma, al shammari am, et al. implementation and characterization of coating pure titanium dental implant with sintered β-tcp by using nd: yag laser. saudi dent j. 2019; 31: 242-50. 2. kim kt, eo my, nguyen tth, et al. general review of titanium toxicity. int j implant dent. 2019 ; 5: 10 . 3. burakov ae, galunin e v., burakova i v., et al. adsorption of heavy metals on conventional and nanostructured materials for wastewater treatment purposes: a review, ecotoxicol environ saf. academic press; 2018; 148: .702–712. 4. zhang y, lawn br. novel zirconia materials in dentistry. j dent res. 2018 ;97: 140-147 5. pieger s, salman a, bidra as. clinical outcomes of lithium disilicate single crowns and partial fixed dental prostheses: a systematic review, mosby inc.; 2014; 112: p. 22–30. 6. shao h, fang j, wang h, et al. effect of electrospinning parameters and polymer concentrations on mechanical-to-electrical energy conversion of randomly-oriented electrospun poly(vinylidene fluoride) nanofiber mats. rsc adv. 2015; 5: 14345-50. 7. rusli msic, hassan mi, sultana n, et al. characterization of pcl/zeolite electrospun membrane for the removal of silver in drinking water. j teknol. 2017; 79:89–95. 8. safi in, hussein bma, al-shammari am. testing and characterization of sintered β-tricalcium phosphate coat upon zirconia dental implant using nd: yag laser. j laser appl. 2019;31:032002-13. 9. anis sf, hashaikeh r. electrospun zeolite-y fibers: fabrication and morphology analysis. microporous mesoporous mater. 2016; 1:78–86. 10. vashista m, paul s. correlation between full width at half maximum (fwhm) of xrd peak with residual stress on ground surfaces. philos mag. 2012; 92: 4194204. 11. zhu c, lv y, qian c, et al. microstructures, mechanical, and biological properties of a novel ti-6v4v/zinc surface nanocomposite prepared by friction stir processing. int j nanomedicine 2018;13:1881-98. 12. zahmakiran m, özkar s. zeolite confined nanostructured dinuclear ruthenium clusters: preparation, characterization and catalytic properties in the aerobic oxidation of alcohols under mild conditions. j mater chem. 2009; 19 :7112-8. 13. prasopdee t, sinthuvanich c, chollakup r, et al. the albumin/starch scaffold and its biocompatibility with living cells. mater today commun. 2021; 2 7: 102164. 14. davarpan r, rafienia m, salehi rozve h, et al. fabrication and characterization of electrospun poly lactic-co-glycolic acid/zeolite nanocomposite scaffolds using bone tissue engineering. j bioact compat polym. 2018; 33:63–78. 15. lin sc, lin wc, hu tc, et al. evaluation of the bonding strength between various dental zirconia models and human teeth for dental posts through in vitro aging tests. coatings 2021; vol 11, page 1017. 16. song n, wang z, xing y, et al. evaluation of phase transformation and mechanical properties of metastable yttria-stabilized zirconia by nanoindentation. materials (basel). 2019; 12: 1677. الخالصة القراص مادة الزركنيوم دايوكسايد المستعمله في زراعة االسنان عند طالئها بتراكيز مختلفة من :هو تقييم قابلية االبتالل والصالدة الهدف .مادة الفوجاسيت : ثالثون قرص مصنع من مادة الزركونيوم دايوكسايد تقسم الى عشرة اقراص غير مطليه و عشرة اقراص مطلي ب نسبهالمواد والطرق aراص اخرى مطليه بنسبه عشرة بالميه من الفوجاسيت بواسطة جهاز النسج الكهربائي ل بحث اختالف ثالثة بالمية من الفوجاسيت وعشرة اق .الصفات في الصالدة وزاوية اتصال الماء لمواد زراعة االسنان انخفاض في الى : هذه الدراسة ذكرت زيادة في الصالدة في تركيز السبعه بالمئه من القوجاسيت مع دايوكسيد الزركونيوم باالضافهالنتائج .زاوية اتصال الماء تريجيا حتى يصل الى الصفر في نسبة السبعة بالمئة من الفوجاسيت : زاوية اتصال الماء تنخفض حتى تختفي في تركيز السبعه بالمئة من الفوجاسيت المطلي لدايوكسيد الزركونيوم وفي نفس االستنتاجات .لمجاميع االخرى نتيجة تغير الشكل الخارجي للمادة المراد طالئها وخواص مادة الطالءالتركيز خاصية الصالدة تصبح كبيرة مقارنة با articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. dropbox 11 suhair 59-65.pdf simplify your life haitham final.doc j bagh college dentistry vol. 26(3), september 2014 effect of zirconia restorative dentistry 13 effect of zirconia surface treatments on the shear bond strength of veneering ceramic inas h. kareem, b.d.s, (1) haitham j. al-azzawi, b.d.s., m.sc. (2) abstarct background: the aim of the study was to investigate the effect of surface treatments of zirconia (grinding and sandblast with 50μm, 100 μm) on shear bond strength between zirconia core and veneering ceramic. material and methods: twenty-eight presintered y-tzp ceramic specimens (ips e.max zircad, ivoclar vivadent) were fabricated and sintered according to manufacturer’s instructions. the core specimens were divided randomly in to 4 groups, group 1: no surface treatment, group2: zirconia specimens were ground with silicon carbide paper up to1200 grit under water cooling, group3: zirconia specimens were ground and sandblast with 100 μm alumina, group 4: zirconia specimens were ground and sandblast with 50 μm alumina. surface roughness of specimens were analyzed by surface profilometer, then veneering ceramic (ips e.max ceramic, ivoclar vivadent) was applied on the specimens& fired according to manufacturer’s instructions. all specimens were subjected to shear force in a universal testing machine at a crosshead speed of 1mm/min. the shear bond strength values were analyzed with one-way anova; the fractured surfaces were examined with a stereo-microscope to observe the failure mode. results: the mean of shear bond strength values in mpa were 24.75 for group 4, (17.72) for group 3, (17.68) for group2, (14.61) for group 1.the airborne-particle abrasion with 50μm group showed significantly higher bond strength than other groups. the airborne-particle-abraded with 100 μm group was not significantly different from grinding group. conclusion: with limit of this study, the sandblast with 50 μm alumina was enhance the sbs between zirconia &veneering ceramic, and zirconia-veneering ceramic bonding is not only influenced by surface roughness. but also may be other factors. keywords: zirconia specimens, veneering ceramic, sandblast, shear bond strength. (j bagh coll dentistry 2014; 26(3):13-17). الخالصھ .السیرامیك قشرهو یمعلى قوه الربط القصي بین ھیكل الزركون یمالغرض من ھذه الدراسھ لفحص تأثیر الطرق المختلفھ لمعاملھ السطح لماده الزركون ال توجد :المجموعھ االولى:حسب تعلیمات المصّنع،وتم توزیع العینات عشوائیًا الى اربع مجامیع) ایفوكالر فیفادینت,ایماكس ,زركاد ( یمه الزركونتم تحضیر ثمان وعشرین عینھ من ماد حك العینات ثم تخدیشھا بواسطھ :موعھ الثالثھ المج,مایكرومیتر1200تدریجیا الى الحجم ) سیلكون كارباید(العینات بأستخدام اوراق الحك) حك(شحذ::معاملھ للسطح ، المجموعھ الثانیھ ، بعد عملیات الحك والتخدیش یتم فحص )مایكرون 50(حك العینات ثم تخدیشھا بواسطھ االلومینیوم اوكساید حجم : ، المجموعھ الرابعھ)مایكرون 100(االلومینیوم اوكساید حجم ، ثم تم بناء ماده السیرامیك على جمیع العینات ثم تم صھر ماده السیرامیك حسب تعلیمات المصّنع،تم قیاس قوه )ومیترالبروفایل(خشونھ سطح العینات بواسطھ جھاز قیاس خشونھ السطح ر لكل لتحدید نوع الكس) ستیریو مایكرسكوب(احادي االتجاه، ثم تم فحص العینات بواسطھ المایكرسكوب anova،تم اجراء االحصائي بواسطھ )االنسترون(الربط باستخدام جھاز .عینھ (میكاباسكال،وللمجموعھ االولى )17,68( لثانیھوللمجموعھ ا,میكاباسكال )17,72(وللمجموعھ الثالثھ,میكاباسكال) 24,75(معدل قوه الربط للمجموعھ الرابعھج ان النتائ اظھرت واظھرت النتائج انھ الیوجد فرق بین المجموعھ ,ت اعلى من المجامیع االخرىكان) مایكرون 50میكاباسكال، قوة الربط للمجموعھ الرابعھ مجموعھ الحك ثم التخدیش ب )14,61 .)مجموعھ الحك فقط(والمجموعھ الثانیھ) مایكرون 100مجموعھ الحك ثم التخدیش ب (الثالثھ وقد اظھرت الدراسھ ان قوه الربط بین المادتین ال ,السیرامیكشره قو یم مایكرون بعد عملیھ الحك تزید قوه الربط بین ھیكل الزركون 50ضمن حدود ھذه الدراسھ فان عملیھ التخدیش ب .یم خشونھ سطح الزركونتتأثر فقط ب introduction zirconia-based materials are used as a core for crowns and fixed dental prostheses (fdps) in restorative dentistry, due to their superior esthetics, biocompatibility and mechanical properties. to achieve optimal esthetics, zirconia frameworks are veneered with a ceramic material, adding veneer ceramics in layers provides the definitive restoration with individual optical characteristics (1). however, clinical failures (chipping and/or delamination of veneering ceramic) of veneered yttria-stabilized tetragonal zirconia polycrystal (ytzp) frameworks were reported in 15% of cases after 2 years follow-up (2). according to fischer et al, bond strength is determined by a range of factors, including chemical bonds, mechanical int (1) m.sc. student. department of conservative dentistry, college of dentistry, university of baghdad (2) professor. department of conservative dentistry, college of dentistry, university of baghdad erlocking, type and concentration of defects at the interface, wetting properties, and the degree of compressive stress in the veneering layer (3). mechanical or chemical surface treatments promote an increase in the porosity and roughness of dental ceramics, improving wetability (4). it was reported that the bonding strength and the mode of failure were significantly affected by some surface treatments such as air-borne particle abrasion or use of liner material (5,6) . airborne-particle abrasion is a routine way to roughen and clean porcelain bonding surfaces of zirconia, although its role in zirconia to porcelain bonding has not been confirmed (7). it is important to consider that airborne particle abrasion results in a phase transition at the surface, changing the crystal structure from tetragonal to monoclinic. these crystal structures exhibit different coefficients of thermal expansion (cte). the coefficient of thermal expansion of monoclinic j bagh college dentistry vol. 26(3), september 2014 effect of zirconia restorative dentistry 14 zirconia (7.5･10-6/ k) is significantly lower than that of tetragonal zirconia (10.8･10-6/k). the effect of sandblasting on the mechanical strength of y-tzp and the bond quality to veneering ceramics is a discussed subject (3). the aim of this study was to investigate the effect of surface treatments of zirconia: grinding and sandblast with (50μm, 100 μm) alumina on shear bond strength between zirconia core and veneering ceramic. materials and methods the presintered y-tzp block (ips e.max zircad, ivoclar vivadent, schaan, liechtenstein) were divided to specimens (dimensions: 8mm in height, 15.5mm in width,19mm in length). then the specimens were sintered in furnace (infire htc speed sintering furnace, sirona) according to the cycle recommended by manufacturer. after sintering, approximately 25% shrinkage was occurred in zirconia specimens. after sintering, the dimensions of specimens was (11.7 mm in width, 14.3 mm in length, 6mm in height), then (28) zirconia specimens were divided randomly to four groups according to the surface treatment, each group contains (7) specimens, group 1 (control group) zirconia specimens were remained without any surface treatment. group2 (grinding group): zirconia specimens were ground by using the grinder\ polisher device (mopao 160e, china)with silicon carbide paper up to1200 grit (8) under water cooling at speed (600 rpm) for 10 sec for each direction. group 3 (grinding and sandblast with (100) µm alumina): zirconia specimens were ground in the same manner as in group 2.then zirconia specimens were abraded vertically on ground surface with (100µm) alumina (al2 o3) particles (garreco, inc., united states) at an air pressure (0.3) mpa for (10) second and at fixed distance of (10) mm between the nozzle and the surface of the specimens (8). group 4 (grinding and sandblast with 50 µm alumina): zirconia specimens were ground in the same manner as in the group 2.then the zirconia specimens were abraded vertically on ground surface with (50µm) alumina (al2 o3) particles (cobra, renfert-gmbh, germany) at an air pressure (0.3) mpa for (10) second and at fixed distance of (10) mm between the nozzle and the surface of the specimens (8). application of veneering ceramic all specimens were cleaned with 70％ethyl alcohol for (10) minutes in a digital ultrasonic cleaner (model cd-4820\china), and air dried. a liner was applied to all specimens by using a brush to create an even layer (7).then zirliner was fired in calibrated porcelain furnace (p3000, ivoclar vivodent, schaan, liechtenstein) according to the manufacturer’s recommendations. then the ceramic was added incrementally onto the customizemade stain less steel mold (on the prepared surfaces of the zirconia) by using brush, the excess liquid sucked off with paper tissue, the veneering procedure was continued until the mold completely filled. then, firing of ceramic\dentin was performed in a calibrated porcelain furnace (p 3000, ivoclar vivadent, schaan, liechtenstein) according to the manufacturer’s recommendations. because of the volumetric shrinkage during firing of porcelain, the additional porcelain was added by same previous technique and fired under the same conditions to achieve the desired dimensions of ceramic(10mm in length,5mm in width,3mm in height) (8). surface roughness evaluations the surface roughness of working surface was analyzed for all specimens before and after surface treatment by surface roughness tester (tr 200 – en 104, time group inc., china). six measurement were performed for each specimen and the average value were calculated (9). shear bond strength test the specimens were placed in a custom-made holder and mounted in a universal testing machin . load was applied parallel to the long axis of the specimens and as close as possible to the interface, with a chiselshaped piston at a constant crosshead speed of 1 mm/min until failure (3). the maximum force (n) was recorded, and shear bond strength (sbs) in (mpa) was calculated by dividing the load (n) by the surface area of bonded area (mm2). types of failure all specimens were examined under the stereomicroscope (x 20) to investigate the type of bonding failure. (10) failure modes were classified as follow: (5) cohesive failure, adhesive failure, combination. statistical analysis one –way anova test to see if there is any statistical significant difference among and within the groups, t -test was performed to examine the source of differences. j bagh college dentistry vol. 26(3), september 2014 effect of zirconia restorative dentistry 15 results surface roughness result the result showed that the highest mean of surface roughness is related to group 1 (no surface treatment) which was (1.13 µm), followed by group 3 (the grinding and sandblast with 100µm) which was (0.88µm) followed by group 4 (grinding and sandblast with 50μm) which was (0.5 µm) followed by group 2 (grinding only) which was (0.039 µm) as shown in the table (1). table 1: descriptive statistics of the surface roughness of zirconia specimen in (µm) groups mean sd (±) min max group 1 (control) 1.13 0.07 1.018 1.242 group 2 (grinding only) 0.039 0.007 0.03 0.049 group 3 (grinding and sandblast with 100μm) 0.88 0.08 0.758 0.985 group 4 (grinding and sandblast with 50μm) 0.5 0.03 0.458 0.562 shear strength result the result showed that the highest mean of sbs is related to group 4 (the grinding and sandblast with 50µm) which was (24.75mpa), followed by group 3 (grinding and sandblast with 100μm) which was (17.72 mpa) followed by group 2 (grinding only) which was (17.68 mpa) followed by group 1 (control group) which was (14.61mpa). this is clearly shown in bar-chart. fig (1). figure 1: bar –chart according to mean value of shear bond strength (in mpa) for total value of four groups. discussion sufficient bond strength between the veneering ceramic and the substructure is important for the long-term clinical success of zirconia restorations. bond strength is determined by many factors: strength of the chemical bonds, mechanical interlocking, type and concentration of defects at the interface, wetting properties, and the degree of compressive stress in the veneering layer due to a difference in the coefficients of thermal expansion between zirconia and the veneering ceramic (11,12). one or more surface treatment is typically used to increase the bond strength, zirconia surface treatment, such as airborne-particle abrasion or the application of a liner, had a significant effect on bond strength (13). in this study, zirconia specimens (zircad, ivoclar vivadent) were veneered with their manufacturer-recommended veneering ceramics (e.max ceram, ivoclar vivadent) to ensure the compatible cte between zirconia specimens and ceramic veneer because the high cte mismatch between zirconia specimens and ceramic veneer resulted in a region of high stress above the ceramic-core interface consequently, a crack initiated and propagated in the vicinity of the interface in the veneering ceramic (14). liners can be applied as an intermediate layer between the zirconia substrate and the veneering ceramic to mask the framework and increase the wetting properties of the zirconia surface. the application of liner material is only recommended for layering veneer ceramics, where it improves bond strength with zirconia substrate and reduces the interfacial failure percentage (13). in this study, according to manufacture, liner (ips e.max zirliners are suitable for the application on ips e.max zircad) was applied and fired before the veneer ceramic was applied. in this study, the sbs test was used. the sbs test has been widely used because of its relative simplicity and ease of use compared to the micro tensile bond strength (mtbs) test. other advantages of sbs testing are ease of specimen preparation, a clear test protocol, and rapid production of test results (5). in this study, the results of roughness for control group showed higher roughness than other groups, but the result of sbs for control group showed lower than other groups, this may be due to the amount of monoclinic zirconia in control group high compared with other groups. the coefficient of thermal expansion of monoclinic zirconia is 7.5×10-6/k, and that of tetragonal zirconia is 10.8×10-6/k. while the coefficient of thermal expansion of veneering ceramic (ipse.max ceram) is 9.5 ± 0.25 × 10 -6 /k. j bagh college dentistry vol. 26(3), september 2014 effect of zirconia restorative dentistry 16 accordingly, an increase in the difference in the coefficient of thermal expansion between the tzp framework and the veneering ceramic leads to tensile stress in the veneering layer due to the quite low coefficient of thermal expansion of the monoclinic phase and lead to decrease in bond strength (15). the results agree with results by oguri et al.(16) the result of this study disagree with results by teng et al.(8) , this difference may be due to the use of different study methods and conditions. in spite the result of surface roughness of grinding group was showed lower than other groups, the sbs of this group higher than control group. according to kosmac et al, this may be due to the locally developed temperature during severe machine grinding, in spite the water cooling, may have exceeded the t→m transformation temperature (about 700 c) above which the tetragonal zirconia is thermodynamically stable(17) the finding of this study disagrees with the result of mosharraf et al.(10) who found the grinding dramatically decreased the sbs especially in white zirconia group and this difference may be due to the hand grinding was used in the mentioned study, while the machine grinding was used in present study. in spite the results showed the surface roughness of group 3 (grinder and sandblast with 100μm) higher than group 2 (grinding only) and group 4 (grinder and sandblast with 50μm) but the sbs of group 3 showed no significant difference with group 2and significantly lower than group 4, this is due to the zirconia surface roughness and the proportion of the monoclinic phase was correlated directly with abrasive particle size. (18) according to grigore et al. the application of coarse sandblasting involves higher kinetic energy, thus creating a greater defect zone, surface roughness, and monoclinic content in the subsurface layer (18) .this finding is in agreement with fischer et al. (3) who stated increased surface roughness of zirconia by sandblasted did not enhance shear strength. the results of this study disagree with the results gašparić et al. (19). this difference may be due to the use of different methods and surface modification (grinding procedure, sandblast pressure, sandblast time). the result of group 4 (the grinding and sandblasted with 50 µm) showed the highest sbs this may be due to the sand blast 50 µm after grinding provide moderate roughness and porous so provide adequate retention for the veneering ceramic and induce less t-m transformation compared with group 3 and group 1, .this finding disagrees with the result of fischer et al. (3) and teng et al. (8). this difference may be due to the grain size of sandblast particle in the mentioned studies was (110μm) larger than (50 μm) which was used in group 4 of this study. most of the specimens demonstrated combined failure or cohesive failure and none of surface treated group's demonstrated adhesive failure, and only control group showed adhesive failure with 28.5%, this result indicated the surface treatment decrease the interfacial (adhesive) failure between zirconia core and veneering ceramic. the results of this study agree with kim et al., 2011 who stated all specimens demonstrated combination fracture mode (adhesive and cohesive failure). (7) within the limitation of this study, it was possible to conclude that: 1. the surface treatment (grinding and\or sandblast with alumina particles) of zirconia core is significantly increased the shear bond strength between zirconia framework and veneering ceramic. 2. shear bond strength (sbs) value of the sandblast with 50µm alumina after grinding is significantly higher compared with other surface treatments. 3. there is no different in sbs between grinding group and sandblast with 100 µm, this result suggested that zirconia-veneering ceramic bonding is not only influenced by surface roughness. but also may be other factors. 4. the surface treatments of zirconia framework is decreased the adhesive failure of veneering ceramic. acknowledgement the especial thanks to dr. nazar naumen for his supply some of materials free. references 1. aboushelib mn, kleverlaan cj, feilzer aj. microtensile bond strength of different components of core veneered all ceramic restorations. part iii: double veneer technique. j prosthodont 2008; 17: 9-13 2. vult von steyern p, carlson p, nilner k. all-ceramic fixed partial dentures designed according to the dczirkon technique. a 2-year clinical study. j oral rehabil 2005; 32:180-7. 3. fischer j, grohmann p, stawarczyk b. effect of zirconia surface treatments on the shear strength of zirconia/veneering ceramic composites. dent mater j 2008; 27: 448-54. 4. pazinatto f, lopes f, marquezini j, de castro f, atta m. effect of surface treatments on the spreading velocity simplified adhesive systems. j appl oral sci 2006; 14: 393-8. 5. ozkurt z, kazazoglu e, unal a. 'in vitro evaluation of shear bond strength of veneering ceramics to zirconia. dent mater j 2010; 29:138-46. 6. fischer j, stawarczyk b, sailer i, hammerle ch. shear bond strength between veneering ceramics and ceriaj bagh college dentistry vol. 26(3), september 2014 effect of zirconia restorative dentistry 17 stabilized zirconia/alumina. j prosthet dent 2010; 103: 267-74. 7. kim h, pil lim h, park y, vang m. effect of zirconia surface treatments on the shear bond strength of veneering ceramic. j prosthet dent 2011; 105:315-22. 8. teng j, wang h, liao y, liang x. evaluation of a conditioning method to improve core-veneer bond strength of zirconia restorations. j prosthet dent 2012; 107: 380-7. 9. sato h, yamada k, pezzotti g, nawa m ,ban s. mechanical properties of dental zirconia ceramics changed with sandblasting and heat treatment. dent mater j 2008; 27(3): 408-14. 10. mosharraf r, rismanchian m, savabi o, hashemi ashtiani a. influence of surface modification techniques on shear bond strength between different zirconia cores and veneering ceramics. j adv prosth 2011; 3: 221-8. 11. isgro g, pallav p, van der zel j, feilzer a. the influence of the veneering porcelain and different surface treatments on the biaxial flexure strength of a heat-pressed ceramic. j prosthet dent 2003; 90: 46573. 12. de jager n, pallav p, feilzer aj. the influence of design parameters on the fea-determined stress distribution in cad-cam produced all-ceramic crowns. dent mater 2005; 21: 242-51. 13. aboushelib m, kleverlaan c, feilzer a. microtensile bond strength of different components of core veneered all-ceramic restorations. part ii: zirconia veneering ceramics. dent mater 2006; 22: 857-63. 14. guazzato m, proos k, quach l, swain m. strength, reliability and mode of fracture of bi-layered porcelain/ zirconia (y-tzp) dental ceramics. biomaterials 2004; 25: 5045-52. 15. fischer j, stawarczyk b. compatibility of machined ce-tzp/al2o3 nanocomposite and a veneering ceramic. dent mater 2007; 23: 1500-5. 16. oguri t, tamaki y, hotta y, miyazaki t .effects of a convenient silica-coating treatment on shear bond strengths of porcelain veneers on zirconia-based ceramics. dent mater j 2012; 31(5): 788–96. 17. kosmac t, oblak c, jevnikar p, funduk n, marion l. the effect of surface grinding and sandblasting on flexural strength and reliability of y-tzp zirconia ceramic. dent mater 1999; 15:426-33. 18. grigore a, spalleka s, petschelt a, butza b, spieckera e, lohbauer u. microstructure of veneered zirconia after surface treatments: a tem study. dent mater 2013; 29(11):1098-107. 19. ga pari l, schauperl z, mehulić k. shear bond strength in zirconia veneered ceramics using two different surface treatments prior veneering. coll. antropol 2013; 37(1): 121–5. sulafa f.doc j bagh college dentistry vol. 28(2), june 2016 salivary oxidative stress pedodontics, orthodontics and preventive dentistry 145 salivary oxidative stress markers in relation to vascular disease risk of type two diabetes mellitus dalia kudier abbas, b.d.s, m.sc. (1) sulafa k. el-samarrai, b.d.s., m.sc., ph.d. (2) abstract background: cardiovascular disease (cvd) is an important complication of type 2 diabetes mellitus (t2dm). oxidative stress plays a major role in the development of cvd. saliva has a diagnostic properties aiding in the detection of systemic diseases. this study aimed to assess the association between salivary oxidative stress markers and the risk of vascular disease (vd) in t2dm patients. materials and methods: one hundred t2dm patients and fifty apparently healthy males were enrolled in this study. saliva sample was collected for assessment of oxidative stress markers including: lipid peroxidation plasma thiobarbituric acid-reactive substances (tbars), uric acid (ua) and total antioxidant capacity (tac) levels. arterial stiffness index (asi) was used for the assessment of vd risk. results: according to asi, t2dm patients were categorized into two groups: group a: t2dm patients without vd risk. group b: t2dm patients with vd risk. the mean values of tbars and ua of group b showed a statistically highly significant elevation compared to group a and controls (p<0.01). the mean value of tac of group b showed a statistically highly significant decrease when compared to group a and controls (p<0.01). conclusion: the increase in salivary tbars and ua levels and the decrease in the tac level can be used as an indicator for the increase of risk for vd in t2dm patients. key words: type 2 diabetes mellitus, vascular disease risk, salivary oxidative stress. (j bagh coll dentistry 2016; 28(2):145-148). introduction type 2 diabetic patients have higher risk of cvd compared with those without diabetes (1). a non-invasive and effective method for early detection of vd used to indicate the stiffness of the arteries is asi (2, 3). oxidative stress plays a major role in the development of cvd (4). reactive oxygen species (ros) can stimulate oxidation of ldl, cholesterol, cholesterol derived species, protein modifications which can lead to foam cell formation and atherosclerotic plaques and vascular thrombosis (heart attack and stroke)(5). saliva is like blood, a complex fluid containing a variety of enzymes, hormones, antibodies, antimicrobial constituents. therefore, most compounds found in blood are also present in saliva (6). saliva has a dynamic diagnostic properties aiding in the detection of oral and systemic disease by using the salivary biomarkers (7,8). the relationship of salivary oxidative stress markers including: tbars, ua and tac were studied in relation to t2dm in previous studies (9,10). in this study the aim is to investigate the risk of vd in t2dm patients through studying salivary tbars, ua and tac all together as an indicator of risk for vd. (1)ph.d. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad materials and methods one hundred t2dm patients and fifty apparently healthy males were enrolled in this study recruited from national diabetes center, university of al-mustnasiriya, from january 2014 to february 2015. t2dm patients were on oral hypoglycemic drugs. their age range was 45–55 years and duration of diabetes mellitus was 2-15 years. the exclusion criteria for the t2dm patients were smokers, patients treated with insulin, patients with a concurrent acute illness or with a major liver, thyroid or other endocrine diseases, patients suffered from endpoints of vd: angina pectoris, myocardial infarction, transient ischemic attack and stroke. the asi was measured after training and supervision by a specialist physician in the national diabetes center, university of almustnasiriya by using an automated digital oscillometric device that is called commercially as (vital vision) and which provides an indicator, the h-value (arterial hardness indicator) (figure 1), that quantifies the degree of arterial hardness depending on the variations in pulse wave amplitude obtained while measuring blood pressure (11). the saliva sample collection was performed without any stimulus in the morning (9 to 11 am), it was collected on ice, patients and healthy were asked to rinse their mouth with normal saline. all subjects refrained from eating, drinking for a minimum of one hour before saliva collection. subjects were comfortably seated and, j bagh college dentistry vol. 28(2), june 2016 salivary oxidative stress pedodontics, orthodontics and preventive dentistry 146 after a few minutes of relaxation, they were trained to avoid swallowing saliva and asked to lean forward and spit all the saliva they produced for 10 minutes. the collected saliva was centrifuged at 3000 rpmfor 10 minutes; the clear supernatants were separated and stored frozen at (-20 co) untilassayed. oxidative stress markers assessment including tbars was conducted according to shah and walker (12), estimation of ua was conducted according to fossati et al.(13) and tac was conducted according to prieto et al.(14). anova test for more than two independent means and lsd was used to measure the precision of a variety of means between two mean values. to estimate the diagnostic efficiency for vascular disease risk in t2dm patients of each single parameter of the present study; receiver operating characteristic (roc), sensitivity and specificity was measured. a probability value (p<0.05) was considered to be statistically significant and (p<0.01) was considered to be statistically highly significant. pattern 1: 1 to 3 bars appear when the cardiovascular system is normal pattern 2: 4 to 6 bars suggest a condition of progressing arterial hardness figure 1: h-value measurement result on the lcd display of asi measuring device results according to asi, t2dm patients were categorized into two groups: group a: t2dm patients with normal asi (without vd risk) group b: t2dm patients with abnormal asi (with vd risk) table (1) shows a comparison of salivary oxidative stress markers among group a, group b and controls. the mean values of tbars and ua of group b showed a statistically highly significant elevation compared to group a and controls (p<0.01). concerning the comparison between group a vs. controls for the mean values of tbars and ua, the results revealed significant (p<0.05), highly significant (p<0.01) difference, respectively (table 1). the mean value of tac of group b showed a statistically highly significant decrease when compared to group a and controls (p<0.01). concerning the comparison between group a vs. controls for the mean values of tac the results revealed no significant difference (p>0.05) (table 1). the area under the receiver operator characteristic (roc) curve was used to discriminate between t2dm patients with vd risk and t2dm patients without vd risk depending on the levels of salivary oxidative stress markers (tbars, ua and tac) (table 2 and figure 1). the area under the curve was highest for salivary tac (roc area =0.842, p<0.01) , followed by salivary ua (roc area = 0.805, p<0.01) and salivary tbars (roc area =0.752, p<0.01) (table 2 and figure 1). discussion the identification of t2dm patients with a higher risk to vd is a priority need since such patients suffer from risk of cvd more than double in comparison with those age-matched individuals (1). in this study, tbars level was significantly higher in t2dm patients than in controls. this result is in accordance with a study conducted by al-rawi (9), who found that salivary tbars level was elevated in t2dm patients. furthermore, the results of the current study showed that salivary tbars level was significantly higher in t2dm patients with vd risk than in those without risk, such results are consistent with an iraqi study conducted by zaidan (15) who found that serum and saliva tbars were significantly higher in patients with myocardial infarction than in controls. the finding in the current study that ua level was higher in t2dm patients compared with j bagh college dentistry vol. 28(2), june 2016 salivary oxidative stress pedodontics, orthodontics and preventive dentistry 147 controls and in t2dm patients with vd risk compared with those without risk is in accordance with the results of many studies that investigated the role of ua as an antioxidant in t2dm and vd. it was noted that t2dm patients have higher levels of serum ua(16), and so they might represent an additional vd risk factor in these patients (17, 18). in an epidemiological study conducted by zoppini et al. (19) assessing the association of serum ua levels with all-cause and cvd mortality in t2dm patients and after adjusting for several baseline confounding factors, the major finding of this study suggested that higher serum ua levels are associated with increased risk of vd mortality in t2dm patients, independent of conventional risk factors. in this study salivary tac level was lower in t2dm patients with vd risk compared to t2dm patients without vd risk. in a recent study conducted by mussavira et al. (20), tac was decreased in the saliva of t2dm patients in comparison with healthy controls. in regard to tac level in patients with cvd, several studies had found a significantly lower serum tac level in patients with cvd (21, 22). in conclusion, the increase in salivary tbars and ua levels and the decrease in the tac level in t2dm patients is an indicator of risk for vd and this may make salivary oxidative stress markers another noninvasive method to detect vd risk in t2dm patients. table 1: salivary oxidative stress markers of t2dm patients according to arterial stiffness index (asi) in comparison with controls variables study groups lsd-test group a mean ±sd n=50 group b mean ±sd n=50 control mean ±sd n=50 anova pvalue group a vs. group b control vs. group a control vs. group b tbars (µmol/l) 1.28±0.38 1.60±0.37 1.10±0.27 <0.001 <0.001 <0.05 <0.001 uric acid (mg/dl) 3.02±1.51 4.43±1.31 2.03±1.02 <0.001 <0.001 <0.001 <0.001 tac (µmol/l) 543.51±239.93 270.74±171.31 580.16±240.87 <0.001 <0.001 >0.05 <0.001 df between groups:2, df within groups:147 table 2: area under receiver operator characteristic (roc) curve for prediction of vascular disease risk in t2dm patients depending on the levels of salivary oxidative stress markers variables roc area under curve pvalue tbars (µmol/l) 0.752 < 0.001 uric acid (mg/dl) 0.805 < 0.001 tac (µmol/l) 0.842 < 0.001 a b c figure 1: roc diagram showing the trade-off between sensitivity (rate of true positive results) and 1-specificity (rate of false positive test results) for a.tbars, b. uric acid and c. total antioxidant measurements when used as a test to predict vd risk in t2dm patients, differentiating them from t2dm patients without vd risk j bagh college dentistry vol. 28(2), june 2016 salivary oxidative stress pedodontics, orthodontics and preventive dentistry 148 references 1. laakso m, lehto s. epidemiology of macrovascular disease in diabetes. diabetes rev 1997; 5: 294–315. 2. kaibe m, ohishi m, komai n, ito n, katsuya t, rakugi h, ogihara t. arterial stiffness index: a new evaluation for arterial stiffness in elderly patients with essential hypertension. geriatrics and gerontology international 2002; 2: 199–205. 3. altunkan s, oztas k, seref b. arterial stiffness index as a screening test for cardiovascular risk: a comparative study between coronary artery calcification determined by electron beam tomography and arterial stiffness index determined by a vital vision device in asymptomatic subjects. eur j internal medicine 2005; 16: 580-4. 4. pham-huy la, he h, pham-huyc. free radicals, antioxidants in disease and health. int j biomed sci 2008; 4(2): 89-96. 5. vijaykumar s, saritha g, fareedullha md. role of antioxidants and oxidative stress in cardiovascular diseases. annals of biomedical res 2010; 3:158-73. 6. lee yh, wong dt. saliva: an emerging biofluid for early detection of diseases. am j dent 2009; 22(4): 241–8. 7. malamud d, isaac r. chavez r. saliva as a diagnostic fluid. dent clin north am 2011; 55(1):159–78. 8. knosp wm, knox sm, hoffman mp. salivary gland organogenesis. wiley interdiscip rev dev biol 2012; 1: 69-82. 9. al-rawi nh. oxidative stress, antioxidant status and lipid profile in the saliva of type 2 diabetics. diabetes & vascular disease res 2011; 8(1): 22–8. 10. mussavira s, dharmalingam m, omana-sukumaran b. salivary glucose and antioxidant defense markers in type ii diabetes mellitus. turk j med sci 2015; 45: 141-7. 11. mars medical products co., ltd. vital vision user’s guide, 2009. http://www. mars.com.tw. 12. shah sv, walker pd. evidence suggesting a role for hydroxyl radical in glycerol induced acute renal failure. am j physiol renal fluid electrolyte physiol 1988; (24): f438-f443. 13. fossati p, prencipe l, berti g. use of 3, 5-dichloro 2-hydroxybenzenesulfonic acid/4-ami nophenazone cvhromogenic system in direct enzymic assay of uric acid in serum and urine. clin chem 1980; 26(2): 227– 31. 14. prieto p, pineda m, aguilar m. spectrophotometric quantitation of antioxidant capacity through the formation of a phosphomolybdenum complex: specific application to the determination of vitamin e. analytical biochem 1999; 269: 337–41. 15. zaidan tf. lipid peroxidation and caeruloplasmin levels in serum and saliva of acute myocardial infarction patients. kufa med j 2009; 12(2): 75-83. 16. saggiani f, pilati s, targher g, branzi p, muggeo m, bonora e. serum uric acid related factors in 500 hospitalized subjects. metabolism 1996; 45:1557–61. 17. fukui m, tanaka m, shiraishi e, harusato i, hosoda h, asano m, kadono m, hasegawa g, yoshikawa t, nakamura n. serum uric acid is associated with microalbuminuria and subclinical atherosclerosis in men with type 2 diabetes mellitus. metabolism 2008; 57: 625-9. 18. newman ej, rahman fs, lees kr, weir cj, walters mr. elevated serum urate concentration independently predicts poor outcome following stroke in patients with diabetes. diabetes metab res rev 2006; 22: 79–82. 19. zoppini g, targher g, negri c, stoico v, perrone f, muggeo m. elevated serum uric acid concentrations independently predict cardiovascular mortality in type 2 diabetic patients. diabetes care 2009; 32(9): 171620. 20. mussavira s, dharmalingam m, sukumaran bo. salivary glucose and antioxidant defense markers in type ii diabetes mellitus. turk j med sci 2015; 45: 141-7. 21. wronska-nofer t, nofer jr, stetkiewicz j, wierzbicka m, bolinska h, fobker m, schulte h et al.evidence for oxidative stress at elevated plasma thiol levels in chronic exposure to carbon disulfide (cs2) and coronary heart disease. nutrition, metabolism and cardiovascular diseases 2007; 17(7): 546-553. 22. lidebjer c, leanderson p, ernerudh j, jonasson l. low plasma levels of oxygenated carotenoids in patients with coronary artery disease. nutrition, metabolism and cardiovascular diseases 2007; 17(6): 448–56. j bagh college dentistry vol. 26(1), march 2014 immunoflourescent oral diagnosis 103 immunoflourescent assessment of herpes simplex virus (hsv) type 1 in oral lichen planus muthanna k. ali, b.d.s., m.sc. (1) abstract background: oral lichen planus is one of the most common dermatological diseases presenting in the oral cavity. hence, viral infection of the oral mucosa may be involved in the pathogenesis of oral lichen planus, taking in to consideration the oncogenic potential of hsv-1, this study aimed to assess the presence of herpes simplex virus type one by direct immunoflourescent in oral lichen planus. this study aimed to assess the presence of hsv type1 by direct immunofluorescent in histopathologically diagnosed olp material and method: twenty formalin fixed embedded tissue blocks of oral lichen planus with 2 positive control cases were taken from patients having infection with herpes labialis, us biological herpes simplex virus-1 glycoprotein c was used for detection of hsv-1 ag by direct immunofluorescence assay results: one case of oral lichen planus showed positivity of hsv 1 with a nonstatistical significance. conclusion: the present study couldn’t find any correlation between hsv-1 positivity with clinical and histopathological features of olp. key words: olp, hsv, immunofloresant assay. (j bagh coll dentistry 2014; 26(1):103-107). introduction lichen planus (lp) is a chronic mucocutaneous disease that affects the skin and the oral mucosa with unknown aetiology. oral lichen planus (olp) affects women more than men, and occurs predominantly in adults over 40, although younger adults and children may be affected (1). olp may arise anywhere in the oral cavity. the buccal mucosa, tongue and gingiva are commonly affected sites, whereas palatal localization is uncommon (2). lesions are typically bilateral and often appear as a mixture of clinical subtypes. oral lichen planus (olp) may present reticular, bullous or erosive form and occurs more frequently than the cutaneous form and tends to be more persistent and more resistant to treatment (2, 3). oral lichen planus is probably of multifactorial origin, possibly induced by drugs or dental materials, psychological factors, infective agents, and often idiopathic. the etiopathogenesis appears to be complex, with interactions between genetic, environmental, lifestyle factors, and interesting new associations, such as with liver disease, have emerged (4). viral infections have recently been linked with olp. herpes simplex virus-1 (hsv-1), cytomegalovirus (cmv), human herpes virus-6 (hhv-6) (5,6), epsteinbarr virus (ebv) (5,7,8), human papilloma virus (hpv) (7) and hepatitis c virus (hcv) (5,6) are virus types that have been studied in the etiopathogenesis of olp. hence, viral infection of the oral mucosa may be involved in the pathogenesis of olp. (1)assistant lecturer, department of oral diagnosis, college of dentistry / university of baghdad many dna viruses are known to infect the oral and peri-oral mucosa. herpes simplex virus (hsv: human herpesviruses types 1 and 2) causes an acute gingivostomatitis, herpes labialis (cold sores) and recurrent intra-oral herpes (9). the specific demonstration of herpes simplex virus in smears from the oral lesion may be accomplished by immunofluorescent staining in which fluorescein-labeled antibodies to the virus react with viral antigen present in the infected epithelial cells. the infected cells showing characteristic yellow-green fluorescence are visualized by ultraviolet microscopy. this method has been quite successful in the specific diagnosis of oral lesions with herpes simplex virus (10). the aim of the present study was to assess the presence of hsv type1by direct immunofluorescent in histologically diagnosed olp cases and to correlate its presence with clinical variant, histopathological and demographic features. materials and methods the study was conducted on formalin fixed paraffin embedded tissue specimens of 20 oral lichen planus. the cases were classified according to age, sex, localization and the histopathological type regarding (type of keratinization, degeneration of basal keratinocytes, inflammation intensity and thickness of epithelium). two normal oral mucosal tissues were used as control group with two smears taking from patient having herpes labialis as positive control. us biological herpes simplex virus-1 glycoprotein c (code no. h2033-08a) was used for detection of hsv-1 ag by direct immunofluorescence assay according to manufacturer's protocol. j bagh college dentistry vol. 26(1), march 2014 immunoflourescent oral diagnosis 104 in this study, positive control was used consisted of two patients having infection with herpes labialis, and a swab was taken from the site of infection put on a charged slide and the same procedure for if was done. also two slides of negative control were prepared as the procedure of if to the whole samples but one slide was prepared by putting sample without using the substrate, but instead of that we used the bovine serum albumin, while the other slide was prepared by using distilled water instead of the sample. statistical analyses were performed using chisquare test. results a total of 20 cases of oral lichen planus were utilized in the study. clinical and immunoflourescent analysis of hsv type 1 were given in table 1. out of 20 patients studied 10 (48%) were females and 11 (52%) were males.15 (75%) patients had classical white lesions mostly in the buccal mucosa followed by tongue and lower lip 3 (15%) then one case (5%) for each lower lip and gingiva. most of the lesions were described as reticular forms 12 (60%), followed by plaque 4 (20%), 3(15%) erosive lesions and 1 case (5%) was annular. table 1: relation between the genders and the presence of hsv1 genders presence of hsv1 total relation negative positive x2 continuity correction d.f. p-value females no. 9 0 9 0.861 0 1 1 (ns) % 47.4% 0% 45% males no. 10 1 11 % 52.6% 100% 55% total no. 19 1 20 % 100% 100% 100% table 2: relation between the sites and the presence of hsv1 site presence of hsv1 total relation negative positive x2 likelihood ratio d.f. p-value buccal mucosa no. 14 1 15 0.351 0.591 3 0.898 (ns) % 73.7% 100% 75% gingiva no. 1 0 1 % 5.3% 0% 5% lower lip no. 1 0 1 % 5.3% 0% 5% tongue & lower lip no. 3 0 3 % 15.8% 0% 15% total no. 19 1 20 % 100% 100% 100% j bagh college dentistry vol. 26(1), march 2014 immunoflourescent oral diagnosis 105 table 3: relation between the age and the presence of hsv1 age presence of hsv1 total relation negative positive x2 likelihood ratio d.f. p-value 20-29 no. 3 0 3 1.955 2.199 5 0.821 (ns) % 15.8% 0% 15% 30-39 no. 5 0 5 % 26.3% 0% 25% 40-49 no. 3 0 3 % 15.8% 0% 15% 50-59 no. 6 1 7 % 31.6% 100% 35% 60-69 no. 1 0 1 % 5.3% 0% 5% 70-79 no. 1 0 1 % 5.3% 0% 5% total no. 19 1 20 % 100% 100% 100% table 4: relation between the clinical types and the presence of hsv1 clinical types presence of hsv1 total relation negative positive x2 likelihood ratio d.f. p-value annular no. 1 0 1 0.702 1.057 3 0.788 (ns) % 5.3% 0% 5% erosive no. 3 0 3 % 15.8% 0% 15% plaque no. 4 0 4 % 21.1% 0% 20% reticular no. 11 1 12 % 57.9% 100% 60% total no. 19 1 20 % 100% 100% 100% as far as histopathological features the results of this study showed that sub epithelial mononuclear infiltration, basal cell degeneration, parakeratinization acanthosis and aprominent granular layer were consistent finding in olp figure 1(he). figure 1: olp 20x (he) the number of olp cases that were positive for hsv was only one case (5%) and it was not statistically significant. (fig. 2,3,4). figure 2: positive control smear 20 x j bagh college dentistry vol. 26(1), march 2014 immunoflourescent oral diagnosis 106 figure 3: negative if picture in patient with o.l.p. figure 4: if picture in patient with olp 20 x there was no any correlation between hsv positivity and age, sex, localization, clinical type and histopathological features. discussion the viruses play an important role in oral ulcerations and may therefore elicit activating effects upon immune response (11). hsv-1 is adapted best and performs more efficiently in the oral, facial, and ocular areas (12). hence, viral infection of the oral mucosa may be involved in the pathogenesis of olp. many dna viruses are known to infect the oral and peri-oral mucosa, hsv-1 was one of these oncogenic potential viruses (13). hsv (human herpes viruses types 1 causes an acute gingivostomatitis, herpes labialis (cold sores) and recurrent intra-oral herpes. hsv-1 infections are common vesicular lesions of the skin and oral mucosa. hsv-1 has occasionally been found in the olp, mainly in the erosive lesions in small series (13), however in the present study 1 of 20 olp cases (5%) was positive for hsv-1 in which the infected cells swell to a large size leading to ballooning degeneration (fig2) and was not significant statistically and this result was compatible with other studies as cox et al. (14), which reported hsv-1positivity in 4 cases (14), while de vries et al. and oflatharta et al. could not detect any hsv-1 dna in olp (15,16). they all have concluded that hsv-1 virus has no causative role in the etiopathogenesis of olp. the result of the present study couldn’t find any correlation between hsv-1 positivity and clinical and histopathological features. the low percentage of hsv-1presence in lesional olp does not imply a causative relation between the two. the explanation of the presence of hsv-1virus in olp could be secondary to a locally altered immune response or to a symptomatic shedding which defined as having hsv present without clinical lesions. shedding often occurs at mucosal sites in the eyes, mouth, and genitalia (17). past estimates state that 5% of individuals demonstrate asymptomatic hsv shedding in the oral cavity, but detection methods have improved and sampling frequencies increased (17). the shedding of hsv-1 in the oral cavity tends to be frequent and episodic. the interindividual rates of viral shedding vary widely. both seropositive and seronegative individuals demonstrate asymptomatic shedding. factors that effect shedding include patient age, recent orofacial trauma, and inflammation. most patients experience shedding for a limited time, generally 1to 3 days, but oral trauma or inflammation can prolong the episode. infected saliva is a possible source of transmission of the virus. recent data indicate that healthy individuals shed hsv-1 asymptomatically in the oral cavity for 1 to 2 days for an average of 13 days each month (17) the examination of olp specimens for other oncogenic viruses is certainly important and needed for further large sample studies. references 1. axell t, rundqvist l. oral lichen planus-a demographic study. community dent oral epidemiol 1987; 15: 52-6. 2. bowers ke, sexton j, sugerman pb. commentary. clin dermatol 2000; 18: 497-8. 3. sugerman pb, savage nw, zhou x, walsh lj, bigby m. oral lichen planus. clin dermatol 2000; 18: 533-9. 4. eisen d. the evaluation of cutaneous, genital, scalp, nail, esophageal, and ocular involvement in patients with oral lichen planus. oral surg oral med oral pathol oral radiol endod 1999; 88: 431-6. 5. eisen d. the therapy of oral lichen planus. crit rev oral biol med 1993; 4:141-58. j bagh college dentistry vol. 26(1), march 2014 immunoflourescent oral diagnosis 107 6. rojo-moreno jl, bagan jv, rojo-moreno j, donat js, milian ma, jimenez y. psychologic factors and oral lichen planus. a psychometric evaluation of 100 cases. oral surg oral med oral pathol oral radiol endod 1998; 86:687-91. 7. scully c, beyli m, ferreiro mc, et al. update on oral lichen planus: etiopathogenesis and management. crit rev oral biol med 1998; 9: 86-122. 8. krutchkoff dj, eisenberg e. lichenoid dysplasia: a distinct histopathologic entity. oral surg oral med oral pathol 1985; 60: 308-15. 9. sugerman pb, savage nw. oral cancer in australia: 1983-1996. aust dent j 2002; 47:45-56. 10. lennette eh, magoffin rl. virologic and immunologic aspects of major oral ulcerations. jada 1973; 87: 1055-73. 11. lin ss, chou my, ho cc, kao ct, tsai ch, wang l, yang cc. study of the viral infections and cytokines associated with recurrent aphthous ulceration. microbes and infection 2005; 7(4): 635-44. 12. woo sb, challacombe sj. management of recurrent oral herpes simplex infections. oral surg. oral med oral pathol oral radiol oral endod 2007; 103(3):118. 13. sugerman pb, shillitoe ej. the high risk human papillomaviruses and oral cancer: evidence for and against a causal relationship. oral dis 1997; 3:130-47. 14. cox m, maitland n, scully c. human herpes simplex1 and papillomavirus type 16 homologous dna sequences in normal, potentially malignant and malignant oral mucosa. eur j cancer b oral oncol 1993; 29b: 215-9. 15. oflatharta c, flint sr, toner m, butler d, mabruk mj. investigation into a possible association between oral lichen planus, the human herpes viruses, and the human papillomaviruses. mol diagn 2003; 7: 73-83. 16. de vries hj, van marle j, teunissen mb, picavet d, zorgdrager f, bos jd, et al. lichen planus is associated with human herpesvirus type 7 replication and infiltration of plasmacytoid dendritic cells. br j dermatol 2006; 154(2): 361-4. 17. miller cs, danaher rj. oral herpes virus shedding. dental abstracts 2008b; 53(6): 332-3. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 25 research article the effect of age on the clinicopathological features of oral squamous cell carcinoma alaa s . saeed1,* , bashar h. abdullah2 1 phd student, ministry of health / al sader medical city , al najaf al ashraf ,iraq. 2 professor, department of oral and maxillofacial pathology, college of dentistry ,university of baghdad . * corresponding authors , drbashar69@yahoo.com abstract: : background: squamous cell carcinoma is a disease of elderly peopleand it is uncommon in people with less than 40 years old; however many literatures revealed that tumor developing in patients younger than forty years appears more aggressive at the time of diagnosis. the purpose of the present study was to focus on the clincopathological features of the oral scc in different age groups. material and methods: in this study thirty five cases of paraffin embedded tissue blocks of oral squamous cell carcinoma were studied. the age range was from 16 to 80 years. the clinicopathological data were recorded for evaluating the tumor characters according to age of patients. results : the age was not significantly correlated to the clinicopathological features that involved the gender of the patients, anatomical site of the tumor, perineural invasion , histological grading and staging . keywords: oral squamous cell carcinoma, age category, tumor behavior. . introduction oral scc which is a multifactorial disease can be classified microscopically in to three grads including well differentiated, moderately differentiated and poorly differentiated tumor (1)as was reported in many literatures, a tumor developing in younger patients increased nowadays(2). however, the main etiological factors that have seen in elderly patients rarely occur in young individuals. developing of this malignancy in the young patients mostly associated with different etiologies and different out comes (3). hypothetically, a tumor developing in a young patients may be considered as a distinct clinical entity that needed more research and studies. this study intended to evaluate the clinicopathological features of the oral scc among different age groups. materials and methods this retrospective study applied on thirty five case of paraffin embedded tissue blocks of oral scc including twenty cases of patients with age >forty years and fifteen cases were patients with <forty years. these cases were retrieved from the oral pathology department, college of dentistry, university of baghdad. received date: 5-10-2021 accepted date: 8-11-2021 published date: 15-3-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbcd. v34i1.3088 mailto:drbashar69@yahoo.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3088 https://doi.org/10.26477/jbcd.v34i1.3088 j. bagh. coll. dent. vol. 34, no. 1. 2022 saeed and abdullah 26 the clinicopathological characters of the tumor involved: the gender of the patients, tumor site, histological grading, perineural invasion and tumor staging were collected and studied. from each a tissue block one section of four micron thickness mounted on ordinary glass slide and stained with hematoxylin and eosin for microscopic reexamination. fisher exact test was used to analysis the data with a significant level of p<0.05. results both of the study groups were not significantly different (p>0.05) in their demographic and clinical characteristics (table-1). from a clinical point of view, patients younger than forty years demonstrated advanced stage more than elderly patients as stage iii and iv were recorded for 76.9 % of young patients vs 46.7% for elderly patients ; however, this was not reach the statistical significant. moreover, a slightly higher histological grading was recorded in young patients (33.3% a high grade) than elderly patients (15%) but this difference was non-significant as well. table 1: clinicopathological comparison of the study groups. discussion. it is well known that adult people with smocking history are at a high risk for oral scc development (4). eventhough the fifths and the sevenths decade of the life are the usual age for oral scc(5) , many researchers recorded increasing in the tumors incidence now a days below this age(6).this demographic changing in the tumor incidence is not well obvious because the long period of smocking habit (that have been seen in adults patients) is uncommon in young individuals. so, tobacco smocking may not be an important factor in the tumor development in young patients or it may be considered as a cofactor with other parameters such as viruses including hpv16 (7,8). variables age (year) p.value < 40 > 40 no. % no. % gender male 8 53.3 9 45.0 625 female 7 46.7 11 55.0 site tongue 8 53.3 14 70.0 0.58 floor 4 26.7 2 10.0 buccal mucosa 1 6.7 2 10.0 other 2 13.3 2 10.0 grade low grade 4 26.7 9 45.0 0.361 intermediate grade 6 40.0 8 40.0 high grade 5 33.3 3 15.0 stage stage 1-2 3 23.1 8 53.3 0.102 stage 3-4 10 76.9 7 46.7 perineural invasion positive 3 20.0 5 25.0 0.727 negative 12 80.0 15 75.0 j. bagh. coll. dent. vol. 34, no. 1. 2022 saeed and abdullah 27 despite that, some authors showed poor tumor outcom and more aggressive behavior in the young individuals(9,10).yet, the result of the studies still conflicting and many molecular markers and cell cycle proteins used as a prognostic indicators for the tumor behavior in the young and adult patients(11,12). in the present study, the samples were analyzed and studied as two age categories conidering the forty years was the limit value for the young participants. it should be noted that using such age as break point between the young and adult is common in the research since the tumor incidence is usually high above this age(4,7,13).the present study showed slightly a higher tumor incidence in females than in male patients as 51.4% in the females vs 48.5 % in the males which were in accordance with another study (14). however, males are the most commonly affected and this a slight difference may be related to the life style modification including smocking habits that recently increased among females (15). this study revealed that the most predominant affected anatomical site is the tongue in both age groups which was in accordance to previous iraqistudy (16).with respect to the histological grading, there is no statistically significant difference in both age groups despite that young patients relatively associated with higher grade. this finding was mentioned by other studies (8,15,17). however, some authors suggested that low histological grading is more commonly seen in a young patients (4,18) . clinical analysis of the present study revealed that advanced tumor stage was highly recorded for young patients in comparison to adult patients but it was statistically non significant. this finding was in agreement with other studies(17,19). on the other hand, that shuwei et al. (2020) (20) in their study did not show any differences in tnm staging at the time of diagnosis between old and young patients . advanced tumor stage in young patients might be due to delay in the tumor diagnosis or more aggressive tumor behavior. moreover, when studying the perineural invasion at both age groups non significant difference was recorded. this finding was consistent with another studies (21,22) . conclusion statistically the age was not the main causative factor of the clinicopathological features of the tumor; however the subject was still controversy and large study sample with a molecular basis was required for better understanding of the biological behavior of oral scc in different age groups. conflict of interest : none references 1. dascălu it, coleș e, țîrcă t, et al. histopathological aspects in oral squamous cell carcinoma. j dental sci . 2018;3(2): 000173 2. cassarino ds, derienzo dp, barr rj. cutaneous squamous cell carcinoma: a comprehensive clinicopathological classification part one. j cutan pathol. 2006;33(3): 191-206. 3. ribeiro ac, silva ar, simonato le, et al. clinical and histopathological analysis of oral squamous cell carcinoma in young people.brj.oral maxillofac. surg.2009: 47(2) 95-98. 4. muller s, pan y, li r, et al. changing trends in oral squamous cell carcinoma with particular reference to young patients: 1971–2006. the emory university experience. head neck pathol. 2008 ; 2:60-06. 5. pires fr ,ramose ab, oliveira jb, et al. oral squamous cell carcinoma: clinicopathological features from 346 cases from a single oral pathology service during an 8-year period. j oral science. 2013;21(5), 460-67. 6. shiboski ch, schmidt bl & jordan rc. tongue and tonsil carcinoma. j cancer 2005; 103(9), 1843-49. j. bagh. coll. dent. vol. 34, no. 1. 2022 saeed and abdullah 28 7. udeabor se, rana m, wegener g, et al. squamous cell carcinoma of the oral cavity and the oropharynx in patients less than 40 years of age: a 20-year analysis. head neck onco.2012;4:28-34. 8. supriya nk, srikant n, karen b .comparison of clinicopathological differences in oral squamous cell carcinoma in patients below and above 40 years of age. j clin. diagnostic. res .2017; vol-11(9): zc46-zc5. 9. soudry e, preis m, hod r, et al. squamous cell carcinoma of the oral tongue in patients younger than 30 years: clinicopathologic features and outcome. clin otolaryngol 2010; 35(4):30712. 10. santos-silva ar, ribeiro ac, soubhia ,et al. high incidences of dna ploidy abnormalities in tongue squamous cell carcinoma of young patients: an international collaborative study. histopathology 2011;58(7):112735 . 11. rushatamukayanunt p, morita k, matsukawa s, et al. lack of association between high-risk human papillomaviruses and oral squamous cell carcinoma in young japanese patients. asian pac j cancer prev. 2014; 15(10):413541. 12. luan eg , aline cb, elismauro f , et al. cell cycle markers and a apoptotic proteins in oral tongue squamous cell carcinoma in young and elderly patients. braz oral res.2019; 33-e103. 13. komolmalai n, chuachamsai s, tantiwipawin s ,et al. ten year analysis of oral cancer focusing on young people in northern thailand. j oral sci 2015;57(4):327-334. 14. suresh t, hemalatha a, kumar mh, et al. evaluation of histomorphological and immunohistochemical parameters as biomarkers of cervical lymph node metastasis in squamous cell carcinoma of oral cavity: a retrospective study. j. oral maxillofac. pathol 2015; 19(1), 18. 15. razavi sm & khalesi s. clinico-pathological differences of oral squamous cell carcinoma among younger and older patients. j clin exp pathol .2017; `7: 316. 16. museedi os & younis wh. oral cancer trends in iraq from 2000 to 2008. saudi j.dent.res.2014; 5(1), 41-47. 17. syedmukith r, ahmedmujib br, bastian ts. oral squamous cell carcinoma in elderly vs young patients: a comparative analysis using stnmp stagingsystem. j oralmaxillofac. pathol 2014;5(2):471-475 18. sasaki t, moles dr, imai y, et al. clinico-pathological features of squamous cell carcinoma of the oral cavity in patients <40 years of age. j oral pathol med. 2005;34:129-33 19. iype em, pandey m, mathew a, et al. oral cancer among patients under the age of 35 years. j postgrad med.2001; 47(3):171176. 20. shuwei c, zhu l, jingtao c , et al . older age is a risk factor associated with poor prognosis of patients with squamous cell carcinoma of the oral cavity european archive of oto-rhino-laryngology.2020 ; 277:2573–2580. 21. zhang yy, wang dc, su jj et al. clinicopathological characteristics and outcomes of squamous cell carcinoma of the tongue in different age groups. head& neck 2017;39: 2276-82. 22. gyuheon c, joon s, seung hc et al. comparison of squamous cell carcinoma of the tongue between young and old patients, seoul, korea .j patho transl med.2019;53(6). تاثير العمر على السمات السريرية المرضية لسرطان الفم الحرشفي العنوان: حي سعيد , بشار حامد عبد للا لباحثون: عالء صبا المستخلص حدوثه تحت سن اال ربعين .ولكن وفقا للعديد من الدراسات فان ظهور المرض لدى صغار السن وخصوصا اللذين التزيد اعمارهم الكبارو نادر ى شيوعا لد سرطان الفم الحرشفي اكثر على السمات المرضية للورم لدى فئات عمرية مختلفة عن االربعين يكون اكثر عدوانية ويرتبط بسلوك بايلوجي مختلف . الغرض من الدراسة هوتسليط الضوء عاما تم جمع البيانات لدراسة 80و 16عينة من انسجة سرطان الفم الحرشفي المطمورة بشمع البرافين وكانت اعمار المرضى تتراوح بين 35: اجريت الدراسة على اد وطرق العملالمو .ية السررية وفقا العمار المرضى السمات المرض .العصب حول والغزو مرحلة الورم ، النسيجي التصنيف ، الورم بموقع يتعلق فيما المقارنة المجموعات بين إحصائية داللة ذات فروق الحالية الدراسة تظهر لمالنتائج: عند للورم البايلوجي السللوك لتفسير المناعية المعلمات باستخدام جزئية دراسة الى يحتاج الموضوع. للورم والنسيجية السريرية الصفات تحديد في مؤثر غير عامل العمر: االستنتاجات . المختلفة العمرية الفئات linda final.doc j bagh college dentistry vol. 26(2), june 2014 aging effect of orthodontics, pedodontics and preventive dentistry 144 aging effect of different types of composite resin restoration on shear bond strength to different orthodontic adhesives with sapphire bracket (in vitro comparative study) linda b. jabbar, b.d.s. (1) fakhri a. ali, b.d.s., m.sc. (2) abstract background: this study was performed to determine the effect of aging of different types of composite material restorations on: shear bond strength (sbs) to light cure and no mix chemical cure orthodontic adhesives with sapphire bracket and the debonding failure sites. materials and methods: one hundred forty four composite disks were made from three different composite resin materials which are: 3m filtek z250, 3m filtek z350 and 3m valux plus, each group with (48) disks each, then according to the duration of storage each group was subdivided into two equal groups one of them stored for one day and the other was stored for one month, then each group was further subdivided into two equal subgroups with (12) disks each one bonded with light cure orthodontic adhesive and the other with no mix chemical cure adhesive. the sample was tested for bond strength using the universal testing machine and the adhesive remnant index (ari) was inspected under the stereomicroscope. results: the results revealed that there was a highly significant difference among the three types of composite materials bonded with light cure orthodontic adhesive as showed by anova test, while the t test showed that there was no significant difference between the two storage durations and also between the two orthodontic adhesives for both filtek z250 and valux plus. conclusions: the highest (sbs) values were obtained from filtek z350 samples than other two types of composite. all the samples stored for one day showed higher values of (sbs) than those stored for one month. key words: shear bond strength, sapphire bracket, orthodontic adhesive. (j bagh coll dentistry 2014; 26(2): 144-149). introduction the demand for orthodontic treatment has been gradually increasing among the adult population. this increase in the number of orthodontic patients presents new problems to the orthodontists. as many patients have restored teeth with various restorative materials, such as composite resin, amalgam, and porcelain, orthodontists are more likely to face the difficulty of bonding orthodontic attachments to these materials. particularly in adolescent orthodontic patients, composite resin restorations are often present on the labial surfaces of maxillary incisors and occasionally on the buccal surfaces of posterior teeth. the frequency of composite resin restorations in posterior teeth have increased with the improvement in the properties of aesthetic filling materials.(1) this composite restoration could be newly placed (fresh restoration) or could be aged for long time in a humid environment inside the oral cavity. intra-orally, restorations are constantly immersed in a moist environment. the absorption of water by the composite resin restoration further results in surface degradation, softening of the resin matrix, formation of microcracks, formation of (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. of surface microporosities, loss of filler particles, and chemical degradation of the resin itself (2). when a restorative material absorbs water, its properties change, and its effectiveness as a restorative material is usually diminished. materials with high filler contents exhibit lower water absorption values (3). it is manifested that as the filler particles size of composites decreases, the amount of water sorption increases (4). in general, any orthodontic adhesive may be used for bonding a ceramic bracket to composite restoration; however, it is probably more advantageous to use a light-cured bonding material as direct illumination is possible: the illumination time being less than that required for a metal bracket because of the translucency of the ceramic bracket (5). materials and methods construction of composite disks one hundred forty four restorative composite resin discs, 7 mm in diameter and 3 mm thick, were prepared three types of resin composite (3m filtek z250, 3m filtek z350, 3m valux plus) by conventional condensation method using a metal mould. the mold was adapted on a glass slide so that the deeper layer of composite would be smooth. each layer was cured by light emitting diode (led) for 20 seconds for filtek z250 and j bagh college dentistry vol. 26(2), june 2014 aging effect of orthodontics, pedodontics and preventive dentistry 145 filtek z350 and 40 seconds for valux plus. the last layer was loaded in the mold and covered by celluloid strip and a glass slide was placed over the strip and slightly pressed to extrude the excess of material (6-9). aging procedure the composite disks were aged by putting them in artificial saliva and storing them in the incubator at 37°c and ph 7 checked every 3 days by ph meter (half of them aged for one day and the other half for one month). the saliva was changed every 3 days (10). after completion of the ageing procedure, all specimens were embedded in acrylic blocks, leaving the smooth surfaces of the composite discs exposed for bonding. construction of acrylic blocks one-hundred forty four acrylic blocks were constructed to hold the sample during bonding and debonding procedures. the blocks were made by using a metal mold which consists of two l shape plates and metal plates to form the base on which the l shape plates were fitted. the base plate contains two projections 7.5mm in diameter and 3mm in height which produce a cavity in the acrylic blocks for embedding of composite disks. bonding of bracket the bonding was done by using either a light cure orthodontic adhesive or a no mix chemical cure adhesive (orthotechnology/usa) according to manufacturer instructions for each one of adhesives. upper right stainless steel central incisor brackets (sapphire bracket, hubit company/ korea) were used for bonding to the composite surfaces (figure 1a) according to the manufacturer, the mean area of each bracket base was12.2mm2. at the end of the bonding procedure, the specimens were allowed to bench cure for 30 minutes, then immersed in artificial saliva and stored in the incubator at 37 °c for 24hours prior to brackets debonding (11-13). sbs test shear test was accomplished using a tiniusolsen universal testing machine "h50kt, england" with a 5 kn load cell and at a crosshead speed of 0.05 mm/minute (14-16) with a custom made chisel rod. the specimens were stressed in an occluso-gingival direction (17-19). (figure 1b).the maximum load necessary to debond was recorded in newtons and converted to megapascals (mpa) as a ratio of newtons to surface area of the bracket base. a. bonding of brackets b. debonding of brackets figure 1: bonding and debonding of sapphire bracket. determination of fracture sites the debonded bracket and the composite surface of each disk were inspected under a stereomicroscope (magnification 10x) to determine the predominant site of bond failure (2022).the site of bond failure was scored according to aurtun and bergland (23) as follows: 0 = no adhesive left on the composite surface. 1 = less than 50% adhesive left on the composite. 2= more than 50% adhesive left on the composite. 3 = all the adhesive is left on the composite. statistical analysis data were collected and analyzed using: descriptive statistics: including means, standard deviations, standard errors, minimum and maximum values. inferential statistics: including; a. one way analysis of variance (anova): to test any statistically significant difference among the shear bond strength of the subgroups in each group. b. least significant difference (lsd): to test any statistically significant differences between each j bagh college dentistry vol. 26(2), june 2014 aging effect of orthodontics, pedodontics and preventive dentistry 146 two subgroups when anova showed a statistical significant difference within the same. c. t-test: to test any significant differences between mean shear bond strength of each two subgroups at different storage periods (1 day and 30 days) and different adhesive systems (light cure and no-mix chemical cure). d. chi-square (x²): to test any statistically significant differences between groups and subgroups for the failure site examination results. a p-level of more than 0.05 was regarded as statistically non significant. while a p-level of 0.05 or less was accepted as significant difference as follows: results difference between the effects of aging on shear bond strength statistically t-test was done to detect any difference in the mean values for the shear bond strength between samples aged for one day and 30 days that were bonded with both adhesive systems. there was no significant difference (p > 0.05) in the mean values for the shear bond strength for both (filtek z250 and valux plus) between the two storage periods, while a very highly significant difference ((p ≤ 0.001) between the two storage periods was found for the (filtek z350) samples bonded with light cure adhesive and a significant difference (0.05 ≥ p > 0.01) between the two storage periods for chemical cure bonded samples. difference between the effects of different adhesive systems on shear bond strength t-test showed that there was no significant difference between light cure and chemical cure adhesive systems in both (filtek z250 and valux plus) samples for two storage durations respectively. for the (filtek z350) samples, there was a very highly significant difference between the samples bonded with light cure and chemical cure adhesive systems in both durations of storage with the highest mean values associated with light cure bonded samples. the effect of type of composite on shear bond strength one way analysis of variance (anova) showed a very highly significant difference among the mean values for the shear bond strength of different types of composite materials (filtek z250, filtek z350 and valux plus) bounded with light cure adhesive system that aged for both 1day and 30 days. for the chemical cure adhesive system the one way analysis of variance (anova) showed a significant difference among the mean values for the shear bond strength of different types of composite materials that were aged for one day, while for the subgroups that were aged for 30 days there was no significant difference in the shear bond strength values of the three types of composite bonded with chemical cure adhesive system (table 1). table 1: descriptive data for the shear bond strength values in (mpa). materials mode of curing duration mean s.d. s.e. min. max. filtek z 250 light cure 1 day 8.69 1.21 0.35 7.01 10.7 30 day 8.55 0.70 0.20 7.66 9.71 chemical cure 1 day 8.55 1.05 0.30 7.09 9.84 30 day 8.05 0.82 0.24 6.56 8.89 filtek z 350 light cure 1 day 13.33 1.85 0.53 10.25 15.7 30 day 10.43 1.89 0.54 8.07 12.75 chemical cure 1 day 9.50 2.04 0.59 7.09 12.58 30 day 7.90 1.15 0.33 6.56 9.76 valux plus light cure 1 day 8.46 0.72 0.21 7.38 9.43 30 day 8.01 1.06 0.31 6.56 9.43 chemical cure 1 day 8.01 0.75 0.22 6.97 9.14 30 day 7.84 0.71 0.21 6.56 8.75 the effect of storage duration on the adhesive remnant index the failure site for all specimens stored for 1 day was mainly (score 2) while specimens aged for 30 days it was predominantly (score 0). there was a high significant difference in the ari for (filtek z250, filtek z350 and valux plus) samples aged for 1 day and 30 days for both types of adhesive systems (table 2). the effect of different adhesive systems on the adhesive remnant index the failure site for specimens bonded with light cure adhesive system was mainly (score 2) for (filtek z250, filtek z350) composite restorations and (score 1) for (valux plus) composite restoration for groups stored 1 day and (score 0) for groups aged for one month, while for samples bonded with chemical cure adhesive j bagh college dentistry vol. 26(2), june 2014 aging effect of orthodontics, pedodontics and preventive dentistry 147 system the ari was mainly (score 1) for both (filtek z250,valux plus) while (score 2) for (filtek z350) composite material for groups stored for 1 day, and (score 0) for 30 days aged groups, although there was no significant difference between the two types of adhesives in all composite types for both duration of storage (table 2). the effect of type of composite on adhesive remnant index statistically chi-square test showed that there was a significant differences in the site of bond failure between the three types of materials bonded with light cure materials that aged for 1 day and no significant difference between the samples aged for 30 days, while for composite restoration bonded with chemical cure adhesive system there was no significant difference in the site of bond failure between the three types of composite restoration (table 2). table 2: failure site distribution for all the sample. scores z 250 z 350 valux light cure chemical cure light cure chemical cure light cure chemical cure 1 day 30 days 1 day 30 days 1 day 30 days 1 day 30 days 1 day 30 days 1 day 30 days 0 1 9 2 9 0 8 1 9 1 10 2 10 i 4 3 4 3 3 3 4 3 9 2 8 2 ii 7 0 6 0 9 1 7 0 2 0 2 0 iii 0 0 0 0 0 0 0 0 0 0 0 0 discussion the result of this study shows a significant difference in the shear bond strength between the three types of composite materials with the highest mean value of bond strength (13.33, 10.43mpa) achieved with (filtek z350) when brackets bonded using the light cure adhesive in both storage periods. the possible explanation for this result may be due to the difference in composition of these different types of composite resin as they differ in the organic matrix composition that filtek z350 contains bis-gma in conjugation with udma as a monomer system. the latter was found to be more reactive than bis-gma based resin (24) leading to increase its strength. furthermore, as the bis-gma is highly viscous, in filtek z350 it is diluted by tegdma, pegdma and bis-ema to decrease the viscosity of the bis-gma while in valux plus composite type contains only bisgma as a monomer system and diluted by only tegdma in high percent, such diluents' monomers in valux plus coupled with the presence of hydroxyl groups in the bis-gma molecule, result in an increase in water sorption of resin and decrease the bond strength (25). the composite types differ in the filler amount; size, shape, distribution, hardness of the filler material, the nature and quality of the bond between the filler and the polymer matrix, and the distribution of filler particles in the polymer matrix all have an influence on the wear and mechanical properties of the composite resins. this result agrees with crumpler et al.(26) who reported that in composite resin repair, different composite resin types produced different bond strengths. the result also comes in agreement with chay et al.(27), who found that bonding of orthodontic brackets to different types of provisional materials produce different values of shear bond strength in spite of the difference in materials and methodology used. the result disagrees with viwattanatipa et al.(28) who attempted to determine whether there were any differences in bond strengths when bonding an orthodontic appliance to five different types of composite resins restorations. the reasons for the decrease bond strength after aging could be due to that chemical bonding of a composite resin to another composite resin surface is mediated through the unreacted methacrylate groups, these unreacted methacrylate groups are found in the oxygen-inhibited layer of unpolymerized resin on the surface of the composite, and what allows for the incremental placement and build up of a composite resin restoration. the bond strength between any two layers of freshly placed composite resin is equal to the cohesive strength of the material itself as this is improved by boyer et al.(29). for a relatively new material that has just been cured and polished, there might still be more than 50% unreacted methacrylate groups to copolymerize with the newly added material , however, as the material ages, fewer and fewer unreacted methacrylate groups remain, and the j bagh college dentistry vol. 26(2), june 2014 aging effect of orthodontics, pedodontics and preventive dentistry 148 greater cross-linking reduces the ability of fresh monomer to penetrate into the matrix. the strength of the bond between the original material and the added resin decreases in direct proportion to the time elapsed between polymerization and addition of the new resin. the strength of the adding new composite to an old one is approximately half the strength of the material itself. this result comes in agreement with chiba et al.(30), he found that a tendency for bond strength between new and old composite to decrease after aging and storage of the old material in saliva. the result also agrees with ismail (31), who tested aging on three composite resin, two utilize total etch technique and one utilize self etching bonding agent, the samples were stored for one day, fifteen days, three months and six months. he found that one day storage time of composite had the highest shear bond strength and the lowest shear bond strength was determined at six months of storage time. this result indicates that increase storage time of composite will lead to decrease its bond strength. this finding also comes in agreement with chunhacheevachaloke and tyas (32), lai et al.(33) whereas this results does not coincide with the finding of eli et al.(34),who reported that 48 hours aging of visiofil & p30 composites in fresh human saliva before their subjection to various surface treatments provide repair shear bond strength values ranging from 1 to 3 mpa which were clinically unacceptable. the result disagrees with rinastiti et al.(35),who found that exposure of four different composite resin restorations to an oral biofilm for two weeks, resulted in a statistically significantly decrease in repair bond strength by more than 50%, compared to a non-aged sample. this result agrees with al qahtani et al.(36) who found that filtek z250 is less affected by storage in saliva than filtek z350. in general the mean values of the shear bond for the three types of composite materials were higher with light cure adhesive than those with chemical cure ones. however there were no significant differences in the mean values of bond strengths for the two adhesive systems tested, except for filtek z350 which showed highly significant difference between chemical and light cure adhesive systems. the weakest combination was valux that aged for 30 days bonded with no mix chemical cure adhesive. this difference may be attributed to weak chemical bond of hydrophobic orthodontic adhesive to smooth hydrophilic surface of the hydrated swollen composite restoration. the study result was similar to rathke (37) who found that significantly higher bond strength for the chemically cured and light cured resins but not the no-mix resin, possibly because the chemicals in this adhesive (no-mix) were ineffective in providing higher bond strength. the result also agrees with heravi et al.(38) who found that bonding of orthodontic brackets to fiber reinforced composite frc with different orthodontic adhesives (chemical cure, light cure and no-mix chemical cure) with different surface conditioning will result in higher bond strength values with light cure and chemical cure adhesives but not the no-mix adhesive systems. the result also agrees with lai et al.(33) who bonded metal, ceramic and polycarbonate brackets to silux plustm (3m, st. paul, mn) samples (roughened with soflexm discs) using either a light-cured resin modified glass ionomer cement, a chemical cured composite, or a lightcured composite system. they found the weakest combination being with the polycarbonate/chemically-cured group. the percentage of score 2 is 75% in filtek z350, 58% in filtek z250 while valux plus had only 16.7% for score 2 and the majority is score 1(75%). one possible explanation is that perhaps the adhesive primer was able to penetrate the matrix of (z350) composite due to its small filler size (nanofillers), and once cured, locked the attachment to the resin substrate with more strength than the cohesive strength of the resin itself. the ari of the sample before aging was predominantly score 2 at the bracket-adhesive interface indicating that bond strength between bonding adhesive and the composite 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(a) ban sahib diab, b.d.s., m.sc., ph. d. (b) huda jameel abd alghani, m.a., ph.d. (c) abstract background: the individual differences in emotional and behavioral style can be examined through personality instruments. these differences may explain the health status of the individuals. the purpose of the present study was to assess the influence of personality types on gingival and periodontal health status among teachers in baghdad city in relation to selected salivary hormone (dehydroepiandrosterone). materials and methods: females teachers 534 of randomly selected schools were subjected to personality questionnaire using the riso-hudson enneagram type indicator. teachers were examined to estimate the periodontal status according to the community periodontal index (cpi). a group of teachers were selected for salivary analysis of dehydroepiandrosterone (dhea). results: data analysis showed that the higher mean of scores was reported for the helper personality type among the sample. according to the maximum (cpi) code, significant difference was found in the mean values of individualist personality type scores between the healthy periodontium (code 0) and calculus (code 2) of community periodontal index. no significant correlation was found between salivary dhea concentration (pg /ml) and the scores of the nine personality types. no significant correlation was found between salivary dhea concentration(pg/ml) and number of sextants for cpi codes. conclusions: personality types could influence gingival and periodontal health status of the subjectsso that psychological interventions may be carried out to improve the oral hygiene condition of the population. keywords: personality types, periodontalstatus, dehydroepiandrosterone. (j bagh coll dentistry 2016; 28(4):144-148) introduction riso and hudson defined personality type as “a metaphor for a wide range of behavior and attitude just as in astrology differences, shared by a group of people and reflecting the dynamic interaction among three personality centers (the feeling, the thinking and the instinctive) and nine personality types” (1). personality influences on health appears over centuries of medical writing (2). the work of friedman and rosenman on the association between personality type and coronary heart disease is perhaps the most well-known example of the personality and general health hypothesis (3). psychological science has new opportunities to find relations between oral health status and personality factors. studies have been conducted by researchers to identify whether personality has an association with periodontal health (4,5). (a)ph.d. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (b)assist. professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (c)assist. professor. psychological research center, university of baghdad. periodontal disease is one of the major dental diseases that affect human populations worldwide at high prevalence rates (6). periodontal disease is multifactorial with many risk factors, modifiable like microorganism; smoking, drugs, and nonmodifiable like age; gender and hormonal fluctuations (7). stress also has been diagnosed as a risk factor in periodontal diseases. clinical studies indicated strong relationships between stress and periodontal disease through a direct change in tissue physiology (8,9) or through changes in behavior (10,11). hormones and chemical mediators produced by the organism as the result of psychological influence may explain these effects (12,13). from these hormones, dehydroepiandrosterone (dhea) is known as a hypothalamic-pituitary adrenal (hpa)-related steroid hormone (14). the dhea is considered as a metabolic intermediate in the biosynthesis of the androgen and estrogen steroids hormones. it also has a number of other important functions, it can decrease cholesterol levels, increase bone growth and support the immune system (15). the dhea can increase physical and psychological well-being by increasing energy, j bagh college dentistry vol. 28(4), december 2016 personality types in pedodontics, orthodontics and preventive dentistry 145 deeper sleep, improved mood, more relaxed feeling and better ability to handle stressful events (16). few reports regarding salivary dhea have been presented in the dental field (17,18).this study was designed to investigate the influence of personality types on the periodontal health and salivary dhea concentration. materials and methods the target population of the study was females teachers aged between 29 and 39 years. secondary schools of females were randomly selected in baghdad city, urban only. riso-hudson enneagram type indicator (rheti), version 2.5, was used to determine the scores of the nine personality types of human nature (1). after the agreement of the authors, the (rheti) was translated to arabic and prepared to be used in iraq by al-yassiry (19). the indicator sheet was introduced to each teacher. it requires from each teacher to choose one statement in each pair that best describes her throughout most of life (forced choice). each chosen statement has a score of one while the non-chosen statement has a score of zero. after collection of the scores, each teacher had nine scores of the nine personality types and each personality type should have a score range (0-32). the total scores for the nine types should be equal to 144 (number of paired questionnaires); otherwise the indicator sheet should be neglected. the indicator sheets were checked for incomplete answers and the total scores were calculated for each personality type. periodontal status was recorded according to the community periodontal index (cpi) modified by who (20) as demonstrated in table 1. plain dental mirrors and who probes were used in the examination. six segments were assessed for each individual which were 17, 16, 11, 26, 37, 36, 31, 46, and 47. if less than two functional teeth existed, the sextant was classified as edentulous. a group of teachers (87) was randomly selected from the total sample (534) for salivary analysis of dehydroepiandrosterone (dhea). saliva collection, storage and analysis were according to the manufacturer instructions (demeditec diagnostics gmbh, germany). the collection time of saliva was between 11:00 am and 1:00 pm to minimize any circadian rhythm effects. the teachers were instructed to stop eating for at least two hours. after saliva collection, the samples should be kept at a temperature of 20°c.at the day of saliva analysis, each sample has to be thawed, warmed up to room temperature and centrifuged for 5 to 10 minutes. salivary elisa kit for the hormone is a solid phase enzyme-linked immunosorbent assay based on the principle of competitive binding. data were entered onto microsoft excel and statistically analyzed using spss version 18 software. a pvalue less than 0.05 was considered to be statistically significant. results a sample of 534 teachers from 55 schools was examined, distributed throughout the six directorates of baghdad city, urban only. the total scores for each personality type were calculated from the indicator sheets. table 2 is showing the distribution of teachers according to maximum cpi score by the age groups. the highest percentage was reported for the teachers with healthy periodontium (56.55%) while shallow pockets (4.31%) were the lowest. table 3 is demonstrating the scores of personality types among the study sample. the higher mean of scores was reported for the helper type followed by the peacemaker type. table 4 reveals the differences in the scores of personality types according to maximum cpi codes. statistical significant difference was found in the mean of scores of the individualist type. further analysis using lsd test (to compare the means of scores for each personality type among the four groups of cpi codes) showed that the significant differences was found only between the (code 0) and (code2). this revealed that the scores of individualist type among teachers with healthy periodontium was significantly lower than the scores of individualist type among teachers with calculus (mean difference=0.95, p=0.003). no significant differences were found in the scores of the other personality types (p>0.05). table 5 is showing that the correlation coefficient between salivary dhea concentrations (pg/ml) and the scores of the nine personality types was statisticallynot significant (p>0.05).correlation coefficient between salivary dhea concentrations (pg/ml) and number of sextants of cpi codes was also not significant (no case was reported in the sample of salivary analysis with shallow pockets) as seen in table 6. j bagh college dentistry vol. 28(4), december 2016 personality types in pedodontics, orthodontics and preventive dentistry 146 table 1: codes and criteria of community periodontal index (who, 1997) codes criteria 0 no bleeding, no calculus no pathological pocket 1 bleeding on probing gingival margin, no calculus, no pathological pocket 2 presence of calculus (sub or supra-gingival) with or without bleeding, no pathological pocket 3 pocket 4 5 mm (gingival margin within the black band on the probe) 4 pocket 6 mm or more (black band on the probe not visible) table 2: distribution of teachers according to maximum cpi codes total sample maximum cpi code healthy code 0 bleeding code 1 calculus code 2 shallow pockets code 3 no. % no. % no. % no. % n=534 302 56.55 35 6.56 174 32.58 23 4.31 table 3: the scores of personality types (means and standard deviations) among the study sample personality types mean ± sd the reformer 16.51±4.186 the helper 19.68±3.822 the achiever 17.31±3.206 the individualist 14.27±3.373 the investigator 14.37±3.137 the loyalist 16.65±3.445 the enthusiast 12.65±4.079 the challenger 15.15±4.142 the peacemaker 17.42±3.977 table 4: the scores of personality types according to maximum cpi codes maximum cpi code personality types (mean ± sd) reformer helper achiever individualist investigator loyalist enthusiast challenger peacemaker healthy code 0 n=302 16.67 ±3.99 19.58 ±3.72 17.52 ±3.30 13.89 ±3.26 14.33 ±3.12 16.67 ±3.46 12.86 ±4.14 15.23 ±4.04 17.20 ±3.89 bleeding code 1 n=35 16.29 ±4.46 19.77 ±4.22 16.71 ±2.72 14.51 ±3.61 14.08 ±2.95 16.03 ±2.63 13.25 ±3.68 15.00 ±4.41 18.31 ±3.53 calculus code 2 n=174 16.33 ±4.407 19.71 ±3.79 17.11 ±3.09 14.84 ±3.46 14.50 ±3.26 16.63 ±3.51 12.22 ±4.10 15.08 ±4.27 17.56 ±3.99 shallow pockets code 3 n=23 16.04 ±4.63 20.39 ±4.79 16.86 ±3.32 14.47 ±3.24 14.21 ±2.83 17.47 ±3.77 12.00 ±3.34 14.73 ±4.20 17.78 ±5.28 f value df=3 0.382 0.333 1.221 3.083* 0.228 0.827 1.374 0.150 1.020 *significant, p≤0.05 j bagh college dentistry vol. 28(4), december 2016 personality types in pedodontics, orthodontics and preventive dentistry 147 table 5: correlation coefficient between salivary dhea concentrations (pg /ml) and the scores of the nine personality types personality types r p the reformer -0.06 0.54 the helper -0.12 0.25 the achiever -0.05 0.61 the individualist 0.04 0.67 the investigator -0.07 0.47 the loyalist 0.05 0.64 the enthusiast 0.05 0.63 the challenger 0.03 0.75 the peacemaker 0.09 0.38 table 6: correlation coefficient between salivary dhea concentrations (pg /ml) and the number of cpi sextants no. of sextants r p healthy code 0 0.007 0.95 bleeding code 1 0.03 0.78 calculus code 2 -0.12 0.29 discussion data are still insufficient to determine the exact effects of different psychological factors especially the impact of personality on the oral health conditions. since there are no previous studies in iraq on the relationship between personality types and oral health status, this study was conducted to focus on the relation between personality types(on the basis of questionnaire) and periodontal health status. teachers were the target group in this study, females only. females were the target group in many studies especially in some developing countries. in these studies, periodontal disease was worse in females than males and may be due to frequent child birth, poor nutrition and poor oral hygiene measures (2123). other studies reported more periodontal diseases in males than the females (24,25).teaching is one of the important and high stress professions in which personality type can influence the degree to which stressful situations are being perceived, and influence the teacher’s emotional and cognitive well-being (26). this study showed that the basic personality type among the study group was the helper type followed by the peacemaker type. al yassiry reported that the basic personality type among the college students in baghdad was the achiever type followed by the individualist type (19). in another study conducted in syria, the basic personality type among the college students was the achiever type followed by the loyalist (27). this difference could be due to the differences in the target group regarding ageand occupation. by comparing the personality type scores among groups divided according to the maximum cpicode, the study revealed that the scores of individualist type among teachers with healthy periodontium lower than the scores of individualist type among teachers with calculus. this difference was statistically significant and could be related to different possible explanations. the individualists are self-aware, sensitive, emotionally honest and creative, but can also be moody and self-conscious. they are withholding themselves from others due to feeling susceptible. at their unhealthy levels, they may feel hopeless, possibly abusing tobacco or drugs to escape and more related to the depressive personality disorders (28). the above description of the individualists could make them less concerned in the oral health measures. other possible explanations are the differences in the salivary composition or flow rate due to psychological influence (29, 30). this result is in agreement with another study that supported a possible relationship between certain personality factors and gingival conditions (4). in the present study, no significant correlation was found between the scores of the nine personality types and the concentration of salivary dhea hormone.this finding disagrees with the finding of another study which concluded that personality may be related to dhea reactivity (31).the differences in study design and personality scale may explain this disagreement. work stress among teachers was reported in previous studies (32,33). coping with this stress and teachers adaptation to their work roles may explain these results in the selected salivary hormone among the nine personality types. correlation coefficient between salivary dhea concentrations and cpi codes was also not significant which disagrees with other studies (17,18). these studies concluded that dhea level were found to be increased with periodontal disease severity. the differences in current study design may be related to this finding. in addition to that, wide range of the hormone concentration may be responsible for this disagreement and larger j bagh college dentistry vol. 28(4), december 2016 personality types in pedodontics, orthodontics and preventive dentistry 148 sample size may be needed to confirm this finding.further studies are needed to correlate the personality characteristics with other biomarkers and to investigate the exact influence of personality types on oral health status. references 1. riso d r, hudson r. personality types: using the enneagram for self-discovery. houghton mifflin harcourt, 1996. 2. smith tw, gallo lc. personality traits as risk factors for physical illness. in baum a, revenson t, singer j (eds). handbook of health psychology. hillsdale nj: erlbaum; 2001. pp. 139-72. 3. friedman m, rosenman r. association of specific overt behavior pattern with blood and cardiovascular findings. j am med assoc 1959; 169: 1286–96. 4. minneman ma, cobb c, soriano f, burns s, schuchman l. relationships of personality traits and stress to gingival status or soft-tissue oral pathology: an exploratory study. j public health dent 1995; 55(1): 22–7. 5. shanker rk, mohamed m, hegde s, kumar ms. influence of personality traits on gingival health. j indian soc periodontol 2013; 17(1): 58-62. 6. petersen pe, bourgeois d, ogawa h, estupinan-day s, ndiaye c. the global burden of oral diseases and risks to oral health. bull world health organ 2005; 83(9): 661-9. 7. al-jehani ya. risk factors of periodontal disease: review of the literature. int j dent 2014; 2014: 182513. 8. waschul b, herforth a, stiller-winkler r, idel h, granrath n, deinzer r. effects of plaque, psychological stress and gender on crevicular il-1beta and il-1ra secretion. j clin periodontol 2003; 30: 23848. 9. kamma jj, giannopoulou c, vasdekis vg, mombelli a. cytokine profile in gingival crevicular fluid of aggressive periodontitis: influence of smoking and stress. j clin periodontol 2004; 31: 894-902. 10. deinzer r, ruttermann s, mobes o, herforth a. increase in gingival inflammation under academic stress. j clin periodontol 1998; 25: 431-3. 11. hugoson a, ljungquist b, breivik t. the relationship of some negative events and psychological factors to periodontal disease in an adult swedish population 50 to 80 years of age. j clin periodontol 2002; 29: 247-53. 12. rosania ae, low kg, mccormick cm, rosania da. stress, depression, cortisol, and periodontal disease. j periodontol 2009; 80(2): 260-6. 13. cakmak ob, alkan a, ozsoy s, sen a , ummuhan abdulrezzak u. association of gingival crevicular fluid cortisol/dehydroepiandrosterone levels with periodontal status. j periodontol 2014; 85 (8): e287e294. 14. krobath, pd, salek, fs, pittenger, al. dhea and dhea-s: a review. j clin pharmacol 1999; 39: 32748. 15. watson rr. dhea in human health and aging. usa: crc press; 2011.pp. 3. 16. morales aj, nolan jj, nelson jc, yen ss. effects of replacement dose of dehydroepiandrosterone in men and women of advancing age. j clin endocrinol metab1994; 78(6):1360-7. 17. ishisaka a1, ansai t, soh i, inenaga k, yoshida a, shigeyama c, awano s, hamasaki t, sonoki k, takata y, takehara t. association of salivary levels of cortisol and dehydroepiandrosterone with periodontitis in older japanese adults. j periodontol 2007; 78(9):1767-73. 18. mudrika s, muthukumar r, suresh r. relationship between salivary levels of cortisol and dehydroepiandrosterone levels in saliva and chronic periodontitis. j icdro 2014; 6(2): 92-7. 19. al-yassiry m. the nine personality types of the enneagram. a master thesis, college of education, university of baghdad, 2004. 20. world health organization (who). oral health surveys: basic methods. geneva. 4th ed. 1997. 21. khamrco ty. assessment of periodontal disease using the cpitn index in a rural population in ninevah, iraq. east mediterr health j 1999; 5 (3): 549-55. 22. ali bg, al-rubeye ms, al-obaidi wa. prevalence and severity of gingivitis and periodontitis among a group of adults living in al nasir village, baghdad. j coll dentistry 2001; 8: 24-8. 23. salman fd, saleh km, qasim aa. dental health status of adult population in yemen (thamar city). al– rafidain dent j 2006; 6(2): 144-50. 24. nasir s, arain ah, mohsin a. periodontal diseases among a teaching hospital patients. j pak dent assoc 2010; 19(4): 202-5. 25. alam mdn, mishra p, chandrasekaran sc. gender basis of periodontal diseases. indian j basic and appl med res 2012; 2(1):128-35. 26. coetzee m, cecelia j, helene m. stress, coping resources and personality types: an exploratory study of teachers. acta academica 2009; 41(3): 168-200. 27. abo al sill ms. the enneagram personality types among college student in damascus university. damascus university j 2014; 30: 621-45. 28. riso dr, hudson r. the wisdom of the enneagram: the complete guide to psychological and spiritual growth for the nine personality types. bantam books, usa 1999: pp.180. 29. bergdahla j, bergdahla m. environmental illness: evaluation of salivary flow, symptoms, diseases, medications, and psychological factors. acta odontol scand 2001; 59(2): 104-10. 30. borahan mo, pekiner fn, atalay t. evaluation of effects of the psychological factors on saliva. müsbed 2012; 2(1):s8-s14. 31. do vale sd, joão martin martins jm, fagundes mj, do carm i. plasma dehydroepiandrosteronesulphate is related to personality and stress response. biogenic amines 2011; 25(4): 283–296. 32. abel mh, sewell j. stress and burnout in rural and urban secondary school teachers. j educational res 1999; 92(5): 287-93. 33. pervez s, hanif r. levels and sources of work stress among women school teachers. pakistan j psychol res 2003; 18: 3-4. j bagh college dentistry vol. 29(1), march 2017localization of maxillary oral diagnosis 70 localization of maxillary impacted canine using cone beam computed tomography for assessmentof angulation, distance from occlusal plane, alveolar width and proximity to adjacent teeth vian fouad rahman, b.d.s., h.d.d. (1) ahlam ahmed fatah, b.d.s., m.sc. (2) abstract backgrounds: maxillary canine impaction is complicated and time consuming to treat, for being highly diverse in inclination and location; it may be a companied by root resorption of the neighboring teeth. cbct has been used for its' diagnostic reliability in localization of impacted canine and revealing its' serious local complications. objectives: localization of maxillary impacted canine using cone beam computed tomography for assessment of angulation, distance from occlusal plane, alveolar width and proximity to adjacent teeth. subjects and methods: the study sample was 33 subjects 16 females and 17 males attended to al-wasitti general hospital in baghdad city-oral and maxillofacial radiology department for cbct scan investigationfrom november/2015 to april/2016. by using thecs 9000 device, 3d images and coronal, axial and sagittal views obtained to perform the selected measurements. results: contact of impacted canine to the nearby teeth had a strong effect on their root resorption. vertical or horizontal angulation measurement in axial view, was not possible for a number of cases.comparison of the angulation measurement validity between axial and coronal views, had showed an obvious statistical difference in coronal view for vertical angulation, and in the axial view for horizontal angulation calculation. correlation of the canine localizations found in the study with the measurements, showed a significant statistical difference with age and vertical angulation (coronal view). age or gender correlation with the measurements wasnon significant statistically, except for age with vertical angulation (coronal view). conclusion: utilization of cbct provides a worthy data about the impacted maxillary canine localization, for more explanation and treatment of these cases surgically and by orthodontics. keywords: localization, canine, maxillary, cbct, impaction..(j baghcoll dentistry 2017; 29(1):70-75). introduction the secondary cuspidrepresent the establishment of dynamic occlusion in addition to equiponderant smile.(1)the canine is the pillar or corner stone of the maxillary arch.(2, 3) canine impaction elevates the hazard of cyst formation, infection as well as settlement of longterm prognosis of nearby lateral incisor due to their root resorption. moreover a morbid complexities manifested as referred pain, lack of dental arch length and others.(4, 2) althoughthe optimal treatment choices for the emendation of canine impaction is those options with long-term prognosis which are to get these teeth in collocation. for that reason careful localization and assortment of impacted cuspid is mandatory to manage them in best way. the initial stage of handling is accurate revealing of presence of an impacted maxillary cuspid. (1, 5, 6, 3) precise examination of the neighboring anatomical structures is entailed for localizing an impacted tooth. (7, 8) regarding the diagnosis and treatment planning, the most usual imaging means, (1) master student, department of oral and maxillofacial radiology, college of dentistry, university of baghdad. (2)assist.professor, department of oral and maxillofacial radiology, college of dentistry, university of baghdad. was classic bi-dimensional radiographs by which the semblance of the long axis and the relevance with the adjacent dental and bony structures were not delicate due to superposition of these complex structures in the maxillofacial area. image disfigurement projection mistakes, blurred radiographs; also complex maxillofacial projection onto a bi-d level could decrease the precision and effectiveness, and elevate the hazard of misconstruction of the radiograph. (8, 9) therefore ct was employed for similar conditions, to localize the impactions and assessment of resorption of incisors, because of superior tissue contrast and accurate granted tri-d radiographs. (7, 10, 11, 12, 13) cbct concerning canine impaction has diagnostic potency and may impact on organizing the treatment, in addition it is possible to do a suggestive remediation for the resorption of the roots of incisors. (14) in addition cbct does not distort radiographs of impacted teeth. (8)in contrast to conventional ct it offers a volumetric radiographs at raised spatial resolution with a decreased dose of radiation for the dental arch, the 3d radiography offers the information in depth width and length. (15) in the current study, the use of cbct images is for evaluation of maxillary impacted canine. j bagh college dentistry vol. 29(1), march 2017localization of maxillary oral diagnosis 71 subjects and methods (33) iraqi subjects (17 males and 16 females) with an age range (13-27 years), were referred to the oral and maxillofacial radiology department / alwasitti general hospital in baghdad city, from (november/2015 till april/2016) to have cbct imaging for localization of maxillary impacted canines. 50 cases of maxillary impacted canines were found (22 in females and 28 in males), involved both bilateral and unilateral impactions. all patients participated in the study were informed about it and they were asked to sign an informed consent form before undergoing the examination.the clinical examination included the intraoral examination of each patient in order to meet the selective criteria of the sample. the patients should be without history of orthodontic treatment or orthognathic surgery, no history of dentofacial deformities, pathological lesions at the examined area of the jaw or facial trauma, no gross distortion of dental arches due to cleft lip/palate and with good medical history and no hormonal disturbances. the cbct machine cs 9000 3d extraoral imaging system-carestream dental, was used to obtain the measurements of selected variables which were: 1.impacted maxillary canine localization:in 3d images to show the presence or absence of maxillary canine (fig. 1). the relative position of the impacted maxillary canine was classified to5 basic localization described by fragiskos(16). 2.angulation:the angle between long axis of tooth and the mid-sagittal plane, (vertical angulation) & the angle between the long axis of tooth and occlusal plane(horizontal angulations),as described by al-ansari et al. (17)in axial and coronal view (fig.2, 3). figure 1:impacted maxillary canine localization. figure 2: measurement of vertical and horizontal angulation, axial view figure 3: vertical and horizontal angulation measurement, coronal view. 3.cusp tip distance : the distance from the tip of cusp to occlusal plane line, in coronal view(fig.4) figure4: cusp tip distance measuremet. j bagh college dentistry vol. 29(1), march 2017localization of maxillary oral diagnosis 72 4.rootresorption of adjacent teeth:in sagittal view, based on the grading systemsuggestedby ericson et al. (18):no, mild, moderate and severe resorption. 5. alveolar width (in millimeters): mean widtharound the tooth(fig.5),in sagittal view.(19) figure5: alveolar width measurement. 6. proximity to adjacent teeth: sagittal view,the alveolar width determines the proximity,described byericson et al. (18): no contact or contact. results 56% of the patients were males and 44% females. age range (13-27years) was divided to 3 groups were: (13-15, 16-20, 21 years -older).impacted canine tooth localization was found in the study was:labial localization, labial localization of crown and palatal localization of root, palatal localization and palatal localization of crown and labial localization of root.labial localization had the highest percentage (42%), while least (4%) for palatal localization crown and labial localization root, none was found as ectopic localization. the highest percentage of the study sample unite did not have root resorption forming (56%) of total cases. the remaining had mild and moderate resorption, none showed severe resorption. a significant statistical relation was found between the impacted canines in contact or touch with the neighboring teeth and those without contact(table 1). both vertical or horizontal angulation measurement in axial view, was not possible for a number of the cases,exceeded half of the sample (table2); a single case of measuring vertical angulation in coronal view and another case of measuring horizontal angulation in axial view did not have an angulation with the mid-sagittal and occlusal plane respectively. comparison of the 2 views validity in measurement of vertical angulation showed a higher mean of angulation calculated in coronal than axial view and a significant statistical difference between the 2. a higher mean of horizontal angulation measurement was found in axial than coronal view with a significant difference between the 2 views. correlation of the four impacted canine localizations found with the measurements showed a significant statistical difference only with age and vertical angle (coronal view) (table3). no mentionable statistical difference for gender or age with the measurements, except between age and vertical angulation (coronal view)(table 4). table 1: association between the anatomical proximity of the impacted canine to the nearby teeth and their root resorption touching nearby teeth negative positive total resorptio n n % n % n % no resorption 2 5 86.20 7 3 14.28 6 2 8 56.0 mild 3 10.34 5 1 3 61.90 5 1 6 32.0 moderate 1 3.448 5 23.80 9 6 12.0 total 2 9 100.0 2 1 100.0 5 0 100. 0 none had severe resorption; p (mannwhitney) = 0.012[s] table 2: the relative frequency of cases whom the measurements of the vertical angulation and horizontal angulation in axial section was technically not feasible n % vertical angulation in axial section-validation can not be measured 29 58.0 measurable 21 42.0 total 50 100.0 horizontal angulation in axial section-validation can not be measured 30 60.0 measurable 20 40.0 total 50 100.0 j bagh college dentistry vol. 29(1), march 2017localization of maxillary oral diagnosis 73 table 3: association between impacted canine tooth localization and measurements impacted canine tooth localization palatal localization palatal localization of crown, labial localization root labial localization crown, palatal localization root labial localization p (anova) age (years) 0.005 [s] range (13 to 27) (14 to 25) (13 to 27) (13 to 21) mean 18.4 19.5 18 14 sd 4.19 7.78 5.11 2.22 se 1.16 5.5 1.37 0.49 n 13 2 14 21 vertical angulation in coronal section 0.008[s] range (24 to 64) (25 to 31) (26 to 88) (18 to 60) mean 41.9 28 45.8 31.2 sd 11.59 4.24 17.68 10.04 se 3.21 3 4.9 2.19 n 13 2 13 21 table 4: association between age and vertical angulation age group (years) 13-15 16-20 21+ p (anova trend) vertical angulation in coronal section 0.012[s] range (18 to 60) (24 to 64) (30 to 88) mean 34 39.4 47.4 sd 11.48 12.62 19.31 se 2.17 3.64 6.44 n 28 12 9 r=0.389 p=0.006 discussion maxillary cuspidsare the perfect alternative preservation of the occlusal outline, they are the principle agent in the permanence and esthetics of the dental arch. (20) accurate diagnosis and localization are needed for the several handling means of the impacted caninewhich involve surgical disclosure then orthodontic induced eruption later.(13) in dentistry obtaining volumetric images of the dental arch and the allaround tissues at a decreased dose of radiation and raised spatial resolution is permitted by cbct utilization. (21) this study agreed with findings of a study by al-ansari et al.(17), that there's a remarkable link of contacting the impacted canine to the nearby teeth and their root resorption. as this study, they also revealed that all the resorption conditions occurred in group of positive touching.uday et al. (19) had demonstrated the same, except that larger number of mild resorption cases happened in negative contact group, may be due to different sample size. alqerban et al. (9), reported a familiar findings specified that following the diagnosis of root resoption of adjacent teeth was determined, the splitting of impacted maxillary canine and the nearby incisors should be instant and, to pause the resorption procedure. in this study 21 cases of vertical angulation measurement as well as 20 cases of horizontal angulation measurement could not be obtained in the axial section respectively. these results were also recognized by uday et al.(19), who reported that in order to gain the longitudinal axis of the tooth and for multiple sorts of impaction if various sections were utilized then it is substantial to direct the angulation to the mid-sagittal plane. due to parallelism with the mid-sagittal plane and occlusal plane respectively, 2 cases of angulation measurement:vertical angle in coronal view (vertical impaction) and horizontal angulation in axial view (horizontal impaction) could not be obtained, this in accordance to alansari et al. (17)and archer ( 23). in this study there was a statistically significant difference in vertical angulation value for coronal than axial section, (p=0.002). a study done by uday et al. (19) did not agree with these,they found that the difference between the 2 sections in mean measurement of vertical angulation was not significant statistically. on the j bagh college dentistry vol. 29(1), march 2017localization of maxillary oral diagnosis 74 other hand they agreed that there's a higher mean angulation recorded in coronal compared to axial section.in the current study there was a statistical important difference for the axial than coronal view (p>0.001), for the horizontal angulation measurement. the highest mean of alveolar bone width surrounding the impacted canine was found in this study in cases of palatal crown labial root localization, which come in accordance to with that obtained by uday et al. (19),the lowest mean found for labial crown palatal root localization;such findings can lead to improvement of surgical approach to make the most suitable window or disclosure of the impacted cuspid by the operator, in order to do appropriate positioning of an orthodontic attachment.there's no statistical significant difference of both genders with all the selected measurements in this study, such result came in agreement with ericson and kurol, (24),elefteriadis(25)preda et al.(7). basically there's a different craniofacial evolution and expansion between both sexes. refferences 1. richardson g and russell ka. a review of impacted permanent maxillary cuspids--diagnosis and prevention. can dent assoc. 2000; 66(9): 497-501. 2. crawford lb. four impacted permanent canines: an unusual case. angle orthod. 2000; 70: 484–9. 3. katiyarradha, pradeep tandon, gyan p. singh, akhil agrawal, and t. p. chaturvedi. management of impacted all canines with surgical exposure and alignment by orthodontic treatment. contempclin dent. 2013; 4(3): 371–373. 4. bishara se. impacted maxillary canines: a review. am j orthoddentofacialorthop. 1992; 101: 159–71. 5. anwar ayesha, jan hameedullah and naureensadia. pakistan oral & dental journal 2008; 28 (1). 6. bedoya mm and park jh. a review of the diagnosis and mamagement of impacted maxillary canines. j am dent assoc. 2009;140(12): 1485-1493 . 7. preda l, fianza1á la, maggio em di, dore1r, schifino mr, campani1r, segu c and sfondrini mf. the use of spiral computed tomography in the localization of impacted maxillary canines. dentomaxillofacial radiology. 1997; 26: 236-205. 8. maverna r and gracco a. different diagnostic tools for the localization of impacted maxillary canines: clinical considerations. progorthod. 2007; 8(1): 28-44. 9. alqerban a, jacobs r, fieuws s and willems g 2011. comparison of two cone beam computed tomographic system versus panoramic imaging for localization of imparte maxillary canines and detection of root resorption. eur j orthod., 33, 93-102. 10. chaushu stella, chaushugavriel and adrian becker. the use of panoramic radiographs to localize displaced maxillary canines. oral surgery, oral medicine, oral pathology, oral radiology, and endodontology 1999; 88(4): 511-6 . 11. ericson s and kurol j. incisor root resorption due to ectopic maxillary canines imaged by computerized tomography: a comparative study in entracte teeth. angle orthodontist 2000; 70: 276-83. 12. mason c, papadakou p and roberts gj. the radiographic localization of impacted maxillary canines: a comparison of methods. eur j orthod. 2001; 23: 25–34. 13. walker l, ensico r and mah j. three-dimentional localization of maxillary canines with cone-beam computed tomography. am j orthoddentofacialorthop. 2005; 128(4): 418-23. 14. oana l, zetu i, petcu a, nemtoi a, dragan e, haba d. the essential role of cone beam computed tomography to diagnose the localization of impacted maxillary canine and to detect the austerity of the adjacent root resorption in the romanian population. rev med chirsoc med nat iasi. 2013;117(1): 212-6. 15. kishnani r and bharat r. a new appoaroch in diagnosis of palatally impacted maxillary canine in orthodontic patient by cone beam computed tomography (cbct) -a case report. iosr -jdms. 2014; 13: 48-51. 16. fragiskos d. fragiskos. oral sugery. springer-verlag berlin heidelberg; 2007. 17. al-ansari nadia b., ghaibnidhal h., alnaimishifaah.. diagnosis and localization of the maxillary impacted canines by using dental multi-slice computed tomography 3d view and reconstructed panoramic 2d view. j bagh college dentistry 2014; 26(1). 18. ericson s, bjerklin k and falahat b. does the canine dental follicle cause resorptionof permanent incisor roots? a computed tomographic study of erupting maxillary canines. angle orthod. 2002; 72: 95-104. 19. uday n m, prashanthkamath, vinod a r kumar, arun b r kumar, rajatscindhia, raghuraj m b, rozario joe. comparison of axial and sagittal views for angulation, cuspal tip distance, and alveolus width in maxillary impacted canines using cbct. journal of orthodontic research 2014; 2(1): 22-26. 20. pokornypaul h., wiensjonathan p. and litvakharold. occlusion for fixed prosthodontics: a historical perspective of the gnathological influence. the journal of prosthetic dentistry 2008; 99(4): 299– 313. 21. pauwels ruben, jilkebeinsberger, bruno collaert, chrysoulatheodorakou, jessica rogers, anne walker, lesley cockmartin, hilde bosmans, reinhildejacobsriabogaerts and keith horner. effective dose range for dental cone beam computed tomography scanners. european journal of radiology 2011;81: 267–271. 22. ericson s and kurol pj. resorption of incisors after ectopic eruption of maxillary canines: a ct study. angle orthod. 2000; 70: 415-23. 23. archer wh. oral and maxillofacial surgery (5thed.). saunders, philadelpha, pa; 1975. 24. ericson s and kurol j. resorption of maxillary lateral incisors caused by ectopic eruption of the canines. a clinical and radiographic analysis of predisposing factors. am j orthoddentofacialorthop. 1988; 94: 503-13. 25. elefteriadisjn,athanasiouae.evaluationofimpactedca nines bymeansofcomputerizedtomography.intjadultorthod orthognathsurg. 1996, 11: 257-64. http://www.ncbi.nlm.nih.gov/pubmed/?term=oana%20l%5bauthor%5d&cauthor=true&cauthor_uid=24505917 http://www.ncbi.nlm.nih.gov/pubmed/?term=zetu%20i%5bauthor%5d&cauthor=true&cauthor_uid=24505917 http://www.ncbi.nlm.nih.gov/pubmed/?term=petcu%20a%5bauthor%5d&cauthor=true&cauthor_uid=24505917 http://www.ncbi.nlm.nih.gov/pubmed/?term=nemtoi%20a%5bauthor%5d&cauthor=true&cauthor_uid=24505917 http://www.ncbi.nlm.nih.gov/pubmed/?term=dragan%20e%5bauthor%5d&cauthor=true&cauthor_uid=24505917 http://www.ncbi.nlm.nih.gov/pubmed/?term=haba%20d%5bauthor%5d&cauthor=true&cauthor_uid=24505917 http://www.ncbi.nlm.nih.gov/pubmed/?term=haba%20d%5bauthor%5d&cauthor=true&cauthor_uid=24505917 http://www.sciencedirect.com/science/article/pii/s0022391308600669 http://www.sciencedirect.com/science/article/pii/s0022391308600669 http://www.sciencedirect.com/science/article/pii/s0022391308600669 j bagh college dentistry vol. 29(1), march 2017localization of maxillary oral diagnosis 75 :الخالصة إستخدم.المجاورة نخرالجذورلألسنان يصاحبه قد وايضا والموقع الميالن في إختالفه لكثرة وذلك ,العالج عند ومطولة معقدة يعتبرحالة العلوي إنطمار الناب:الخلفية المنطمروكشف الناب موقع تقييم في التشخيصية لرصانته وذلك, إستعماله فوائد مقابل في المخاطرالمترتبة تقييم بعد المخروطي الشعاع ذات المقطعية جهازاالشعة .المهمة الموقعية تأثيراته االطباق خط عن العمودي والبعد الميالن لتقييم المخروطي الشعاع ذات المقطعية جهازاالشعة باستخدام المطمور العلوي الناب موقع تحديد: الدراسة من الهدف .المجاورة األسنان من والقرب السنخي العظم وعرض باألشعة للتصوير قسم اشعة الفم و الوجه و الفكين-بغداد في العام الواسطي ذكورحضروالمستشفى61اناثو61مشارك 33 عينة البحث كانت : البحث وطريقة المواد , تاجية) إلىصورمقاطع باالضافة األبعاد صورثالثية على الحصول تمcs 9000باستعمال جهاز .إلىنيسان 5162 الثاني تشرين من المخروطي الشعاع ذات المقطعية إلجراءالقياساتالمختارة.( جانبية, عرضية في واألفقية العمودية الزاوية قياس إمكانية عدم.نخرجذورها في تأثيرقوي له كان المجاورة األسنان من( تماس على كونه) المطمورتشريحيا الناب قرب :النتائج اظهرت وجود فروق احصائية واضحة لصالح المقطع التاجي ٬مقارنة فاعلية قياس الميالن بين المقطعين التاجي و العرضيالحاالت. بعض في العرضي المقطع الناب مواقع بين مهمة إحصائية داللة ذات عالقة وجدتونفس الفروق لصالح المقطع العرضي في قياس الزاوية االفقية. ٬في قياس الزاوية العمودية .العمودية الزاوية وقياس عمرالمشترك مع الدراسة في تقييمها تم التي المطموراألربعة المطمورلزيادة العلوي الناب موقع تقييم حول قيمة يوفرمعلومات المخروطي الشعاع ذات المقطعية جهازاألشعة إستخدام إن الدراسة المعطيات وفق يتبين: االستنتاج .وتقويميا جراحيا الحاالت هذه وعالج توضيح 14safa'a f.docx j bagh college dentistry vol. 28(3), september 2016 corrеlation bеtwееn oral diagnosis 87 corrеlation bеtwееn dual-еnеrgy x-ray absorptiomеtry and panoramic mandibular indicеs in prеdiction of bonе minеral dеnsity in postmеnopausal fеmalеs safa hasan alwan,b.d.s. (1) lamia h. al-nakib, b.d.s., m.sc. (2) abstract background: ostеoporosis is a systеmic disеasе of thе bonе that is charactеrizеd by rеducеd bonе mass, which lеads to incrеasеd bonе fragility and fracturеparticularly in postmеnopausal womеn.thе aims of study was toеvaluatе thе rеlationship bеtwееn mandibular radiomorphomеtric indicеs obtainеd on digital panoramic radiographswith thе bonе minеral dеnsitiеs of thе lumbar spinееvaluatеd using dual-еnеrgy x-ray absorptiomеtry (dxa) scan, in a population of ostеoporotic and non-ostеoporotic fеmalеs. matеrials and mеthods: in panoramic imagеs obtainеd from 60 fеmalе individuals dividеd еqually into thrее groups: controls (20-30 yеars), non-ostеoporotic post-mеnopausal agеd 50 yеars and abovе and ostеoporotic postmеnopausal agеd 50 yеars and abovе, thе mеan was calculatеd for mandibular cortical width (mcw), panoramic mandibular indеx (pmi), mandibular cortical indеx (mci) and gonial anglе indеx (gai) valuеs mеasurеd in thе right and lеft sidеs of thе mandiblе. bonе minеral dеnsity (bmd) valuеs wеrе mеasurеd by dual еnеrgy x-ray absorptiomеtry (dxa) scan. rеsults: significant positivе corrеlation (r) was obsеrvеd bеtwееn bonе minеral dеnsity of lumbar vеrtеbraе and mcw (r=0.706) and pmi (r=0.668) of mandiblе, and a nеgativе corrеlation was obsеrvеd bеtwееn mci and bmd of lumbar vеrtеbraе (r=-0.716). whilе gai did not show any significant diffеrеncе in rеlation to bonе minеral dеnsity. conclusion: this study showеd that mcw, pmi and mci indicеs wеrе usеful for idеntifying fеmalеs with low skеlеtal (bmd), whilе gai was indеpеndablе in dеtеcting ostеoporosis. kеy words: dxa scan, panoramic mandibular indicеs, post-mеnopausal fеmalеs. (j bagh coll dentistry 2016; 28(3):87-91). introduction ostеoporosis is a disеasе charactеrizеd by low bonе mass and micro-architеctural dеtеrioration of bonе tissuе, lеading to bonе fragility and еnhancеd suscеptibility to fracturеs. ostеoporosis is prеdominantly a condition of thееldеrly(1). it affеcts mostly womеn, еspеcially aftеr mеnopausе as a rеsult of еstrogеn withdrawal(2).a major obstaclе to combating ostеoporosis is thе failurе to idеntify individuals who havе ostеoporosis until thе clinical consеquеncеs of ostеoporosis havе occurrеd (i.е., fracturеs form with littlе trauma to thе bonеs)(3). bmd еvaluation by dual-еnеrgy x-ray absorptiomеtry (dxa) tеsting is considеrеd thе gold standard for fracturе risk prеdiction(4). howеvеr, in addition to not bеing rеcommеndеd by thе who as a triagе scrееning tool for ostеoporosis, it has a high financial cost(5). bеcausе thе bonеs of thе oral cavity arе similar in structurе and physiology to various othеr bonеs in thе skеlеton, sеvеral studiеs havе bееn conductеd with thе objеct of dеtеcting whеthеr thеsе skеlеtal changеs in thе mandiblе arе spеcific to thе ostеoporotic stagе(4,5). panoramic radiography has bееn an important componеnt of dеntal diagnostic radiology for ovеr 40 yеars (6). (1) m.sc. studеnt, dеpartmеnt of oral diagnosis, collеgе of dеntistry, univеrsity of baghdad. (2) assistant profеssor, dеpartmеnt of oral diagnosis, collеgе of dеntistry, univеrsity of baghdad. rеcеnt clinical studiеs havе shown that panoramic radiography plays a critical rolе in thе idеntification and еvaluation of ostеoporotic patiеnts or thosе with low bmd by dеntists(7). qualitativе and quantitativе indicеs which includе thе mandibular cortical indеx (mci), mandibular cortical thicknеss (mcw), gonial anglе indеx (gai) or panoramic mandibular indеx (pmi) havе bееn usеd for panoramic radiographs, to assеss thе bonе quality and to obsеrvе signs of rеsorption and ostеoporosis(6). thе prеsеnt study focusеs on obtaining a possiblе mеan of еarly dеtеction of ostеoporosis by panoramic radiography. matеrials and mеthods a cross-sеctional study was conductеd on 60 iraqi fеmalеswho had bееn rеfеrrеd to bonеdеnsitomеtеr cеntеr for bmd еvaluation by dxa tеchniquе at thе xray institutеin thе mеdical city in baghdad. thе patiеnts wеrе askеd to participatе in this clinical trial as voluntееrs, and thеy wеrе thoroughly informеd about thе procеdurе.thе samplе was dividеd into thrее groups according to thеir agе and ostеoporotic status: • 1st group: 20 fеmalеs with agе 20-30 as control group (nonostеoporotic). • 2nd group: 20 postmеnopausal nonostеoporotic fеmalеs with agе from 50 and abovе. j bagh college dentistry vol. 28(3), september 2016 corrеlation bеtwееn oral diagnosis 88 • 3rd group: 20 postmеnopausal ostеoporotic fеmalеs with agе from 50 and abovе. fеmalеs with natural mеnopausе (which occurrs aftеr 12 months of amеnorrhoеa and for which thеrе was no obvious pathologic causе) with no history of hystеrеctomy, wеrе includеd in thе study. smoking, alcoholism and patiеnts with any known systеmic disеasе that would affеct bonе mеtabolism likе hypеrparathyroidism, hypopar athyroidism, hypеrthyroidism, pagеt’s disеasе, ostеomalacia, rеnal ostеodystrophy, cancеrs with bonе mеtastasis or significant rеnal impairmеnt and patiеnts who wеrе on spеcific drugs (corticostеroids) which arе known to havе advеrsееffеcts on bonе mеtabolism wеrееxcludеd from thе study. dual–еnеrgy x–ray absorptiomеtry (dеxa) scan of thеspinal vеrtеbraе (l2–l4) was pеrformеd by using ostеosys dеxxum 3(korеa)machinе. this procеdurе is thе currеnt gold standard for mеasuring bonе mass and dеtеcting ostеoporosis(8). thеrеaftеr,thе patiеnts wеrе thеn subjеctеd to panoramic imaging in thе dеpartmеnt of oral mеdicinе, diagnosis and radiology at thе collеgе of dеntistry (baghdad univеrsity), ondimax 3 digital x-ray machinе manufacturеd by planmеca oy, hеlsinki, finland. aftеr that, thе imagеs wеrе manipulatеd on thе computеr monitor of thе x-ray machinе to achiеvе bеst imagе quality,thеn convеrtеd to jpg (joint photographic еxpеrts group) filеs; so that linеar and angular mеasurеmеnts wеrеcalculatеd by autocad softwarе (2007). thе rеsults of dxa scan wеrе thеn comparеd with thе rеsults of thе indicеs from thе panoramic radiographs. thе following radiomorphomеtric indicеs wеrе mеasurеd for еach patiеnt: • mandibular cortical width (mcw), which is thе mеasurеmеnt of thе cortical width at thе mеntal foramеn rеgion(9). • panoramic mandibular indеx (pmi) is thе ratio of thе thicknеss of thе mandibular cortеx to thе distancе bеtwееn thе supеrior margin of mеntal foramеn and thе infеrior mandibular cortеx, prеsеntеd by bеnson еt al.(10). • mandibular cortical indеx (mci) rеfеrs to thе mandibular cortical shapеs on dеntal panoramic radiographs , and is catеgorizеd into onе of thе thrее groups according to thе mеthod of klеmеtti еt al., as follows: c1: normal cortеx, c2: mild to modеratеly еrodеd cortеx and c3: sеvеrеly еrodеd cortеx(11). • gonial anglе indеx (gai), which rеfеrs to thе sizе of thе gonial anglе of mandiblе(12). thе who diagnostic critеria for ostеoporosis dеfinеs ostеoporosis in tеrms of a t-scorе which is bеlow -2.5 and ostеopaеnia in tеrms of a t-scorе which is bеtwееn -2.5 and -1(13). rеsults thе rеsults showеd that mcw and pmi mеan valuе was thе highеst for thе hеalthy young fеmalе group (group i).whilе, thе mcw and pmi valuе of post-mеnopausal ostеoporotic fеmalе group (group iii) showеd thе lowеst mеan.thе rеsults showеd that all thе thrее groups wеrе statistically highly significant in mcw and pmi as pvaluе<0.001. thе mеangai valuе for group i was thе lowеst among thе rеst of thе study groups. whilе thе gai ofgroup iii showеd thе highеst valuе.thеrеsults showеd that all thе thrее groups wеrе statistically non-significant in gai as p-valuе was 0.21 (tablе 1). rеgarding mci, it was found that group i has normal mandibular cortical indеx (c1). whilе group ii shows lacunar rеsorption (c2) in 15% of thе casеs. and group iii shows lacunar rеsorption (c2) in 45% and clеar porosity (c3) in 40% of thе casеs.thе diffеrеncе bеtwееn thе 3 groups showеd a high statistical significancе as thе pvaluе<0.001(tablе 2). thе rеsults showеd a positivе corrеlation bеtwееn mcw, pmi and t-scorе as r pеarson valuе was (0.706) and (0.668), rеspеctivеly. and a strong nеgativе corrеlation bеtwееn mci and tscorеas r valuе was (-0.716).thеrе is a wеak nеgativе corrеlation bеtwееngaiand t-scorеas r valuе (-0.224);(tablе 3). discussion panoramic radiography is a routinе imaging mеthod in dеntistry and is part of many rеcallprogrammеs. j bagh college dentistry vol. 28(3), september 2016 corrеlation bеtwееn oral diagnosis 89 tablе1: mеan valuеs of mandibular cotical width, panoramic mandibular indеx and gonial anglе indеx according to dеxa rеsults. groups mcw pmi gai mеan sd p-valuе mеan sd p-valuе mеan sd p-valuе normal young group 3.8 0.38 <0.001 0.246 0.032 <0.001 121.9 7.34 0.21 [ns] post-mеnopausal normal group 3.4 0.43 0.207 0.032 123.6 6.74 post-mеnopausal ostеoporotic group 2.3 0.61 0.141 0.043 126 7.97 tablе2: showing frеquеncy and pеrcеntagе of mci in diffеrеnt study groups. hеalthy young group postmеnopausal non ostеoporotic group postmеnopausal ostеoporotic group mci n % n % n % c1 20 100.0 17 85.0 3 15.0 c2 0 0.0 3 15.0 9 45.0 c3 0 0.0 0 0.0 8 40.0 total 20 100.0 20 100.0 20 100.0 tablе3:linеarcorrеlation coеfficiеnt of mci, pmi, gai, t-scorе and agе of all thrее groups t-scorе mcw pmi gai mci r=0.706 p<0.001 r=0.668 p<0.001 r=-0.224 p=0.17 r=-0.716 p<0.001 sеvеral studiеs suggеst that panoramic radiomorphomеtric indicеs may bе usеful for idеntifying patiеnts with lowskеlеtal bonе minеral dеnsity or ostеoporosis (14,15). although somе studiеs havе found no rеlationship bеtwееn skеlеtal and mandibular bmd (7,16). mеasurеmеnt of thе thicknеss of thе mandibular cortical width in panoramic radiographs has bееn suggеstеd as a way to prеdict patiеnts with low bonе minеral dеnsity (17). in thе currеnt study, thе cortical bonе in thе mеntal rеgion was significantly thinnеr in postmеnopausal ostеoporotic fеmalеs if comparеd with post-mеnopausal non-ostеoporotic fеmalеs. this rеsult was еxpеctеd as it concurs with prеvious studiеs(18-,20). bеsidеs that, mcw was also significantly thinnеr in post-mеnopausal groups than thе young hеalthy group, and this can bе attributеd to thе fact that mcw is affеctеd by hormonal changеs likееstrogеns which havе an important rolе in thе rеgulation of skеlеtal dеvеlopmеnt and homеostasis; this is dеmonstratеd by thе dramatic loss of bonе that occurs aftеr mеnopausе.(during еstrogеn dеficiеncy thеrе is prolongation of ostеoclast lifе span duе to inhibition of apoptosis)(21,22).this rеsult was in agrееmеnt withtaguchi еt al. and khojastеhpour еt al.,who statеd that agе was shown to havе a significant corrеlation with thе mcw, as agе incrеasеd, thеrе was a dеcrеasing ratе in cortical width(15,23). panoramic mandibular indеx was first proposеd by bеnson еt al.,as radiomorphomеtric indеx of adult cortical bonе mass(10). prеdictably, in this study pmi dеmonstratеd similar agе-rеlatеd corrеlations as thosе of mcw by showing a statistically significant diffеrеncе among all thе thrее groups; thе rеsult of this study agrееs with that of halling еt al. and kim еt al. (24,25). thе rеsults of this study is consistеnt with thе rеsults ofhornеr and dеvlin, in which thе pmi valuеs mеasurеd in fеmalеs with ostеoporosis on panoramic radiographs wеrе comparеd with thе mandibular bonе valuеs mеasurеd with dxa, and a significant rеlationship was found bеtwееn thе two. thеy concludеd that pmi could bе usеd as an indicator of mandibular bonе dеnsity(18).our rеsults disagrееs with thе study donе by drozdzowska еt al., which showеd that thеrе was no corrеlation bеtwееn pmi and dеxa mеasurеmеnt and thеy suggеstеd that it should not bе usеd as an indicator of skеlеtal status(7). rеgarding thе gonial anglе, in thеprеsеnt study, thе sizе of thе gonial anglе incrеasеs as agе incrеasеs, but it did not show a statistical significant diffеrеncе. which agrееs with thе study conductеd by dutra еt al., donе onbritish population, whеrе thе corrеlation bеtwееn agе and gonial anglе was statistically non-significant(26), also with cеylan еt al., whеrеthе gonial anglе did not incrеasе as agе incrеasеs in thееdеntulous individuals; thеrеforе, thеy statеd that lack of corrеlation bеtwееn thе gonial anglе and thе agе indicatеs that thе anglе doеs not changе with incrеasе of thе individual’s agе(27). thе prеsеnt study disagrееs with that donеby mahdi and al-nakib, which showеd that oldеr subjеcts had significantly largеr gonial anglе than youngеr onеs(28). j bagh college dentistry vol. 28(3), september 2016 corrеlation bеtwееn oral diagnosis 90 onе of thе most commonly studiеd paramеtеrs of mandibular bonе with rеspеct to ostеoporosis is thе porosity of thе mandibular cortical bonе. in thе prеsеnt study, c1 shapе of cortеx was sееn in youngеr fеmalеs, but as agе incrеasеd, thе numbеr of individuals who had c2 and c3 catеgoriеs incrеasеd, prеsumably rеflеcting agе rеlatеd bonе loss. in thе prеsеnt study, c2 and c3 catеgoriеs wеrе prеdominantly sееn in post-mеnopausal ostеoporotic fеmalеs, which wеrе again supportеd by prеvious studiеs (29-31). klеmеtti еt al. еvaluatеd thе mci, which was also known by thе author’s namе. our rеsults confirm thе rеsults achiеvеd by klеmеtti еt al., as thеy suggеstеd that a thin or еrodеd infеrior cortеx of thе mandiblе dеtеctеd on dеntal panoramic radiographs, an indicator of altеrations of thе mandiblе, is usеful for idеntifying postmеnopausal fеmalеs with undеtеctеd low skеlеtal bmd or ostеoporosis(11). rеgarding t-scorе, wе found that thеrе is a positivе corrеlation bеtwееn mcw and t-scorе, this corrеlation was statistically highly significant, and this agrееs with hеkmatin еt al.,who found a significant corrеlation bеtwееn bmd and mcw and positivе corrеlation bеtwееn mcw and tscorе(32). t-scorе was also corrеlatеd positivеly with thе pmi, which statistically has highly significant diffеrеncе that was rеpеatеd by parlani (33). t-scorе, in our study also corrеlatеs positivеly with thе mci, and this is agrееd by gulsahiеt al. (30). from this study, wе can concludе that panoramic radiography givеs sufficiеnt information to makеanеarly diagnosis rеgarding ostеoporosis in post-mеnopausal fеmalеs, and this may bе hеlpful in thе prеvеntion of ostеoporotic fracturеs in еldеrly fеmalеs. references 1. rizzoli r, bruyere o, cannata-andia jb, devogelaer jp, lyritis g, ringe jd, vellas b, reginster jy. management of osteoporosis in theelderly. curr med res opin 2009;25: 2373–87. 2. karasik d. osteoporosis: an evolutionary perspective. hum genet 2008;124: 349–56. 3. nih consensus development panel on osteoporosis prevention, diagnosis, and therapy jama 2001;285: 785–95. 4. horner k, karayianni k, mitsea a, berkas l, mastoris m, jacobs r, et al. the mandibular cortex on radiographs as a tool for osteoporosis risk assessment: the osteodent project. j clin densitom 2007; 10: 138– 146. 5. taguchi a. triage screening for osteoporosis in dental clinics using panoramic radiographs. oral dis 2010; 16: 316–27. 6. yasar f, senar s, yesilova e, akgunlu f. mandibular cortical index evaluation in masked and unmasked panoramic radiographs. dentomaxillofac radiol 2009;38:86–91. 7. drozdzowska b, pluskiewicz w, tarnawska b,. panoramic-base mandibular indices in relation to mandibular bone mineral density and skeletal status assessed by dual energy x-ray absortiometry and quantitative ultrasound. dmfr 2002; 31: 361-7. 8. leite af, figueiredo pt, guia cm, melo ns, de paula ap. correlations between seven panoramic radiomorphometric indices and bone mineral density in postmenopausal women. oral surg oral med oral pathol oral radiol endod 2010; 109: 449-56. 9. ledgerton d, horner k, devlin h, worthington h. panoramic mandibular index as a radiomorphometric tool: an assessment of precision. dentomaxillofac radiol 1997;26:95–100. 10. benson bw, prihoda tj, glass bj. variations in adult cortical bone mass as measured by a panoramic mandibular index. oral surg oral med oral pathol 1991;71: 349–56. 11. klemetti e, kolmakov s, kroèger h. pantomography in assessment of the osteoporosis risk group. scand j dent res 1994; 102: 6872. 12. ceiiareginawinckmahl comparison of morphometric indices obtained from dental panoramic radiography of identifiying individuals with osteoporosis or osteopenia. radiolbris 2008;41:3. 13. el maghraoui a, roux c. dxa scanning in clinical practice. qjm 2008; 101:60517. 14. bollen am, taguchi a, hujoel pp, hollender lg. case-control study on self-reported osteoporotic fractures and mandibular cortical bone. oral surg oral med oral pathol oral radiol endod 2000; 90: 518–24. 15. taguchi a, suei y, ohtsuka m, otani k, tanimoto k, ohtaki m. usefulness of panoramic radiography in the diagnosis of postmenopausal osteoporosis in women. width and morphology of inferior cortex of the mandible. dentomaxillofac radiol 1996; 25: 263– 7. 16. devlin cv, horner k, devlin h. variability in measurement of radiomorphometric indices by general dental practitioners. dentomaxillofac radiol 2001; 30: 120-5. 17. dutra v, yang j, devlin h, susin c. radiomorphometric indices and their relation to gender, age, and dental status. oral surg oral med oral pathol oral radiol endod 2005;99:479–84. 18. horner k, devlin h. the relationship between mandibular bone mineral density and panoramic radiographic measurements. j dent 1998;26: 337–43. 19. taguchi a, tsuda m, ohtsuka m, kodama i, sanada m, nakamoto t, inagaki k, noguchi t, kudo y, suei y, tanimoto k, bollen am. use of dental panoramic radiographs in identifying younger postmenopausal women with osteoporosis. osteoporos int 2006;17: 387–94. 20. bodade pr, mody rn. panoramic radiography for screening postmenopausal osteoporosis in india: a pilot study. ohdm 2013;12:72-65. 21. haslett c, braum we, randolph t, et al. (davidson’s):principles and practice of medicine. 19thed.london: hunter; 2005. pp. 1025-7. 22. marcus r, feldman d, nelson da, rosen cj. osteoporosis. 3rded. elsevier; 2008.pp. 3,1031,14161441. 23. khojastehpour l, afsa m, dabbaghmanesh mh. evaluation of correlation between width and j bagh college dentistry vol. 28(3), september 2016 corrеlation bеtwееn oral diagnosis 91 morphology of mandibular inferior cortex in digital panoramic radiography and postmenopausal osteoporosis. iranian red crescent medical j 2011;13(3):181-6. 24. halling a, perrson gr, berglund j, johansson o, renvert s. comparison between the klemetti index and heel dxa bmd measurements in the diagnosis of reduced skeletal bone mineral density in theelderly.osteoporosis int 2005;16:999–1003. 25. kim y, kim k, koh k. the relationship between age and the mandibular cortical bone thickness by using panoramic radiograph. korean j oral maxillofac radiol 2010; 40:83-7. 26. dutra v, devlin h, susin c, yang j, horner k,. mandibular morphological changes in low bone mass edentulous females: evaluation of panoramic radiographs. oral surg oral med oral pathol oral radiolеndodontol 2006; 102:663-8. 27. ceylan c, yanikoglu n, yilmaz a, ceylan y, .changes in the mandibular angle in the dentulous and edentulous states. j prosthet dent 1998; 80: 680-4. 28. mahdi as, al-nakib lh. assessment of mandibular radiomorphometric indices as predictors of osteoporosis in postmenopausal women (cephalometric reconstructed computed tomographical study). jbcd 2014; 26(2): 50-7. 29. geraels wgm, verheij jgc, van der stelt pf, horner k, lindh c, nicopoulou-karayianni k, et al. osteoporosis and the general dental practitioner: reliability of some digital dental radiological measures.community dent oral epidemiol 2007;35:465–71. 30. gulsahi a, yuzugullu b, imirzahoglu p, gene y. assessment of panoramic radiomorphometric indices in turkish patients of different age groups, gender and dental status. dentomaxillofac radiol 2008;37:288–92. 31. dagistan s, bilge om. comparison of antegonial index, mental index, panoramic mandibular index and mandibular cortical index values in the panoramic radiographs of normal males and male patients with osteoporosis. dentomaxillofac radiol 2010;39: 290–4. 32. hekmatin e, ahmadi ss, ataiekhorasgani m, feizianfard m, jafaripozve s, jafaripozve n,. prediction of lumbar spine bone mineral density from the mandibular cortical width in postmenopausal women. j res med sci 2013; 18: 951–5. 33. parlani s, nair p, agrawal s, chitumalla r, beohar g, katar u.role of panoramic radiographs in the detection of osteoporosis. oral hyg health ijgm 2014; 2: 23320672 j bagh college dentistry vol. 29(1), march 2017 assessment of pedodontics, orthodontics and preventive dentistry 193 assessment of different techniques to detect recurrent carious lesion around amalgam filling noor m. kadhim, b.d.s.(1) ban a. salih b.d.s., m.sc.(2) abstract background: this in-vitro study was to evaluated bitewing radiograph and tactile examination for detection secondary caries adjacent to amalgam restorations. material and method: sixty primary extracted molars with class i and class ii amalgam restorations were selected from children, and examined by bitewing radiographs were taken by using film holders and interpreted on a backlit screen without magnification. then, we used tactile examination with blunt probe. result: the result of this study showed that the best cut-off points for the sample were found by a receiver operator characteristic (roc) analysis, and the area under the roc curve and the sensitivity, specificity and accuracy of the techniques were calculated for enamel (d1) and dentine (d2) thresholds. these parameters were found for each techniques and then compared by the cochran's q test. the tactile examination presented the fair techniques for detecting secondary caries at enamel thresholds for both occlusal and proximal surfaces, while, bitewing radiograph presented good techniques at dentin thresholds. conclusion: tactile examination represented the best performance for detecting enamel secondary caries. while, bitewing radiograph represented the best performance for detecting dentin secondary caries. keywords: secondary caries, amalgam restorations, bitewing radiograph, tactile examination. (j bagh coll dentistry 2017; 29(1): 193-198) introductio amalgam is a restorative material essentially accurate for classes i and ii restorations in teeth that encounter heavy chewing forces(1,2). secondary caries is a disease that occurs on the tooth after the dental restoration has been in place for a period of time (3). it was the major cause most frequently reported in relation to failure and replacement of restorations (4, 5,6, 7). secondary caries is responsible for 60% of all replacement restorations in the typical dental practice (8). the diagnosis of secondary caries is still a challenging topic. so, early detection of these kinds of caries can be helpful to use preventive procedures and control caries development (9,10,11).. as a result, the accurate detection of secondary caries lesions is extremely important. the conventional techniques commonly used for this purpose have been radiographic and tactile examination are the most common techniques applied for detecting secondary caries lesions (12,13). furthermore, radiographic and tactile examination perform better at detecting advanced caries lesions than non cavitated lesions (14,15,16). (1) m.sc. student, department of pedodontics dentistry. college of dentistry. university of baghdad. (2) professor. department of pedodontics and prevention dentistry. college of dentistry. university of baghdad. material and methods this study was carried out on sixty primary extracted molars with class i and class ii amalgam restorations were selected from children. one, two or three surfaces were selected adjacent to the restorations (n = 120) for examination. the specimens were cleaned with a toothbrush with pumice/water slurry and stored in saline solution until the examinations. caries detection techniques 1. bitewing radiograph each two teeth are fixed in cast by wax to the level of cej which pouring on simple articulator. for standardized conditions the bitewing radiographs were taken a kodak ultras-speed film, all of the same batch number was used. and using film holding system with same x-ray machine at the same exposure factors (70 kvp, 8ma with exposure time 0.50 sec).after exposure the film was developed in automatic processor in which the temperature of the developer and developing time were kept rigidly constant. the radiographs was examine on a backlit screen, without magnification. the evaluation was according to the following criteria (17): sound radiolucency restricted to the outer half of the enamel. radiolucency in the inner half of the enamel or at maximum to the outer third of the dentine. radiolucency reaching the middle third of the dentin. radiolucency in the inner third of the dentin. j bagh college dentistry vol. 29(1), march 2017 assessment of pedodontics, orthodontics and preventive dentistry 194 2. tactile examination the tactile examination was perform by probing gently the suspected surfaces with a blunt explorer probe to avoid damage to the dental tissues. additionally, this examination was the last one to be performed in order to avoid interference in the results of the other techniques in case of any damage. the evaluation was regarding the presence of ditches and presence of softened dental tissue, using the following scores (18): 0. no ditches. 1. ditches hardly visible. 2. ditches visible (< 0.2 mm). 3. ditches visible (> 0.2 mm). statistical analysis roc curves: a receiver operator characteristic (roc) is a graphical plot that illustrates the performance of a binary classifier system as its discrimination threshold is varied. the curve is created by plotting the true positive rate (sensitivity) against the false positive rate (1 specificity) at various threshold settings. for the analyses, occlusal and proximal surfaces were dichotomized into sound and decay, and performed for enamel (d1) and dentine (d2) thresholds, and the area under the roc curve and the best cut-off points were obtained. using these cut-off points for sensitivity (ability to recognize secondary caries in teeth with/without cavitations), specificity ( correct recognition of sound tooth structure), and accuracy (percentage of correct diagnosis in sound and decayed teeth) of each techniques were calculated at each threshold. accuracy is measured by the area under the roc curve which interpreted as follow: 90-1 = excellent, 80-.90 = good, 70-.80 = fair, 60-.70 = poor,50-.60 = fail. results the area under the roc curve for the tactile examination at enamel threshold better than bitewing radiograph. while almost bitewing radiograph was good for detection secondary caries at dentin for occlusal surfaces. figure 1: receiver operator characteristic roc plot: bitewing radiograph at enamel threshold for occlusal surfaces figure 2: receiver operator characteristic roc plot: bitewing radiograph at dentin threshold for occlusal surfaces figure 3: receiver operator characteristic roc plot: tactile examination at enamel threshold for occlusal surface figure 4: receiver operator characteristic roc plot: tactile examination at dentin threshold for occlusal surface table 1: the sensitivity, specificity, accuracy and p-value for diagnostic techniques to detect secondary caries at enamel (d1) and dentin (d2) threshold in occlusal surface in primary molars teeth. p-value accuracy specificity sensitivity techniques 0.077 (ns) 0.685 0.308 0.600 d1 bitewing radiograph 0.000 * 0.872 0.335 0.889 d2 0.001 * 0.781 0.318 0.808 d1 tactile examination 0.062 (ns) 0.694 0.200 0.529 d2 ns: non-significant difference (p≥ 0.05) *highly significant difference (p≤ 0.001) https://en.wikipedia.org/wiki/graph_of_a_function https://en.wikipedia.org/wiki/binary_classifier https://en.wikipedia.org/wiki/binary_classifier https://en.wikipedia.org/wiki/true_positive_rate https://en.wikipedia.org/wiki/true_positive_rate https://en.wikipedia.org/wiki/sensitivity_(tests) https://en.wikipedia.org/wiki/specificity_(tests) j bagh college dentistry vol. 29(1), march 2017 assessment of pedodontics, orthodontics and preventive dentistry 195 the area under the roc curve for the tactile examination at enamel threshold better than bitewing radiograph. while almost bitewing radiograph was good for detection secondary caries at dentin for proximal surfaces. figure 5: receiver operating characteristic roc plot: bitewing radiograph at enamel threshold for proximal surfaces figure 6: receiver operating characteristic roc plot: bitewing radiograph at dentin threshold for proximal surfaces figure 7: receiver operating characteristic roc plot: tactile examination at enamel threshold for proximal surfaces figure 8: receiver operating characteristic roc plot: tactile examination at dentin threshold for proximal surfaces table 2: the sensitivity, specificity, accuracy and p-value for diagnostic techniques to detect secondary caries adjacent toamalgam restoration at enamel (d1) and dentin threshold (d2) in proximal surfaces for primary molars teeth. p-value accuracy specificity sensitivity techniques 0.121 (ns) 0.672 0.545 0.789 d1 bitewing radiograph 0.000 ** 0.860 0.500 0.926 d2 0.048* 0.702 0.200 0.612 d1 tactile examination 0.153 (ns) 0.634 0.280 0.500 d2 ns: non-significant difference (p≥ 0.05) * significant difference (p≤ 0.05) **highly significant difference (p≤ 0.001) result of percentile value of sound, enamel caries and dentin caries of each techniques in occlusal and proximal surface of primary molars in groups a,b,c,d tactile examination had higher percentage value in sound surface followed by enamel caries and lower percentage at dentin caries. whereas, bitewing radiograph had high percentile values at dentin caries followed by sound then enamel caries. figure9: illustrated percentile value of different threshold of each techniques at occlusal surface 0 20 40 60 80 100 bitewing radiogra ph tactile examinat ion dentin caries 45 20 enamel caries 26.7 46.7 sound 28.3 33.3 a x is t it le j bagh college dentistry vol. 29(1), march 2017 assessment of pedodontics, orthodontics and preventive dentistry 196 figure 2: illustrated percentile value of different threshold of each techniques at proximal surface discussion: the diagnosis of secondary caries is still a challenging topic. therefore early detection of these kinds of caries can be helpful to use preventive procedures (9,10) and caries control (11). bitewing radiograph and tactile examination are the basic and most commonly used techniques for caries detection. but these techniques are subjective, with a low reproducibility (19). the present study evaluate bitewing radiograph and tactile examination for detection secondary caries adjacent to amalgam restoration for primary molars teeth in vitro. bitewing radiograph was good sensitivity and accuracy for detection demineralize dentin at occlusal and proximal surfaces but poor at enamel threshold, as a result many existing lesions are not detected. a small amount of demineralization at one site may be masked by the radiodensity of the surrounding sound enamel (20). therefore, bitewing radiograph do not recommend for detection of non-evident occlusal and proximal caries in primary molars. this agreed with (21 -36). hence, tactile examination was fair sensitivity and accuracy at enamel threshold for occlusal surfaces but poor at dentin threshold. accordingly, the result of this study confirm tactile examination alone fails to detect a number of occlusal and proximal caries lesions and inadequate for detection caries in deciduous teeth in children. this result agreed with other studies (23,31,33,37,38 42). conclusion bitewing radiograph presented the best performance in detecting dentin secondary caries at occlusal and proximal surfaces in primary teeth restored with amalgam, and at proximal surfaces better than occlusal surfaces. references 1. leinfelder, “do restorations made of amalgam outlast those made of resin-based composite?” the journal of the american dental association, vol. 131, no. 8, pp. 1186–1187, 2000. 2. manhart, f. garcía-godoy, and r. hickel, “direct posterior restorations: clinical results and new developments,” dental clinics of north america, vol. 46, no. 2, pp. 303–339, 2002. 3. feng x. cause of secondary caries and prevention. hua xi kou qiang 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diagnodent for detecting secondary carious lesions associated with resin composite restorations. quintessence int. 2003 feb;34(2):109–16. 10. bamzahim m, aljehani a, shi xq. clinical performance of diagnodent in the detection of secondary carious lesions. actaodontol scand. 2005;63(1):26–30. 11. spiguel mh, tovo mf, kramer pf, franco ks, alves kmrp, delbem acb: evaluation of laser fluorescence in the monitoring of the initial stage of the de-/remineralization process: an in vitro and in situ study. caries res 2009;43:302-307. 12. kidd eam. diagnosis of secondary caries. j dent educ. 2001 oct;65(10):997-1000. 13. ando m, gonzalez-cabezas c, isaacs rl, eckert gj, stookey gk. evaluation of several techniques for the detection of secondary caries adjacent to amalgam restorations. caries res. 2004;38(4):350–6. 14. braga, m.m.; mendes, f.m.; martignon, s.; ricketts, d.n. & ekstrand, k.r. in vitro comparison of nyvad’s system and icdas-ii with lesion activity assessment for evaluation of severity and activity of occlusal caries lesions in primary teeth. caries research.2009; 43(5): 405-412. 15. diniz m.b. et al.: the efficacy of laser fluorescence to detect in vitro demineralization and remineralization of smooth enamel surfaces. photomed. laser. surg., 27, 1, 2009. 0 10 20 30 40 50 60 70 80 90 100 bitewing radiograph tactile examination dentin caries 46.7 13.3 enamel caries 28.3 40 sound 25 46.7 a x is t it le http://www.ncbi.nlm.nih.gov/pubmed/?term=feng%20x%5bauthor%5d&cauthor=true&cauthor_uid=24881200 http://www.ncbi.nlm.nih.gov/pubmed/24881200 http://www.ncbi.nlm.nih.gov/pubmed/?term=silvani%20s%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=trivelato%20rf%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=nogueira%20rd%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=gon%26%23x000e7%3balves%20ld%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=gon%26%23x000e7%3balves%20ld%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=geraldo-martins%20vr%5bauth%5d j bagh college dentistry vol. 29(1), march 2017 assessment of pedodontics, orthodontics and preventive dentistry 197 16. chawla n. · messer l.b. · adams g.g. · manton d.j. an in vitro comparison of detection methods for approximal carious lesions in primary molars. 2012;46:161–169 17. ismail a. i., sohn w., tellez m., amaya a., sen a., hasson h., pitts n. b. the international caries detection and assessment system (icdas): an integrated system for measuring dental caries. community dentistry and oral epidemiology. 2007;35(3):170–178. 18. ando m, gonzalez-cabezas c, isaacs rl, eckert gj, stookey gk. evaluation of several techniques for the detection of secondary caries adjacent to amalgam restorations. caries res. 2004;38(4):350–6. 19. pretty ia. caries detection and diagnosis:noveltechnologies. journal of dentistry. 2006;34(10):727–739. 20. wenzel, a. verdonschot, eh. truin, gj. konig, kg. accuracy of visual inspection, fiber-optic transillumination, and various radiographic image modalities for the detection of occlusal caries in extracted non-cavitated teeth. j dent res. 1992; 71(12):1934-1937. 21. ibrahim gt. evaluation of different clinical methods in detection early carious lesion in approximal surfaces among group of children. m.sc. thesis. university of bagdad. 2001. 22. sheehy ec, brailsford sr, kidd eam, beighton d, zoitopoulos l. comparison between visual examination and a laser fluorescence system for in vivo diagnosis of occlusal caries. caries research.2001;35(6):421–426. 23. bader jd, shugars da, bonito aj: a systematic review of the performance of methods foridentifying carious lesions. j public healthdent 2002; 62: 201–213. 24. bloemendal e, de vet hcw, bouter lm. the value of bitewing radiographs in epidemiological caries research: a systematic review of the literature. journal of dentistry. 2004;32(4):255–264. 25. wenzel a. bitewing and digital bitewing radiography for detecstion of caries lesions. j dent res.2004;83:c72–c75. 26. wolwacz, vf. chapper, a. busato, al. barbosa, an. correlation between visual and radiographic examinations of non-cavitated occlusal caries lesions -an in vivo study. braz oral res. 2004; 18(2):145-149. 27. tranaeus, s. shi, x-. angmar-månsson, b. caries risk assessment: methods available to clinicians for caries detection. community dentistry and oral epidemiology. 2005;33(4):265-273. 28. neuhaus, k.w.; longbottom, c.; ellwood, r. & lussi, a. novel lesion detection aids. monographs in oral science. 2009; 21: 52-62. 29. novaes tf, matos r, braga mm, imparato jc, raggio dp, mendes fm. performance of a pen-type laser fluorescence device and conventional methods in detecting approximal caries lesions in primary teeth in vivo study. caries res 2009;43:36-42 30. newman b, seow wk, kazoullis s, ford d, holcombe t.clinical detection of caries in the primary dentition with and without bitewing radiography. aust dent j. 2009;54(1):23-30. 31. braga mm, chiarotti ap, imparato jc, mendes fm. validity and reliability of methods for the detection of secondary caries around amalgam restorations in primary teeth. braz oral res. 2010;24(1):102–7. 32. neuhaus kw, rodrigues ja, hug i, stich h, lussi a: performance of laser fluorescence devices, visual and radiographic examination for the detection of occlusal caries in primary molars. clin oral investig 2010; 15: 635– 641. 33. novaes tf, matos r, raggio dp, imparato jc, braga mm, mendes fm: influence of the discomfort reported by children on the performance of approximal caries detection methods. caries res 2010; 44: 465–471. 34. ekstrand kr, luna le, promisiero l, cortes a, cuevas s, reyes jf, et al. the reliability and accuracy of two methods for proximal caries detection and depth on directly visible proximal surfaces: an in vitro study. caries res 2011;45:93-9. 35. guerrero, e. validez y seguridad de las pruebas diagnósticas para la caries oculta de dentina: un estudio in vivo. ph thesis. university of seville.2011. 36. rodrigo alejandro dr. haristoy, bitewing radiographic evaluation of interproximal carious lesions on permanent first molars in 6 and 12 year-olds in the public health system of chile. master's theses. university of connecticut graduate school collections.2011: 97. 37. rudolphy mp, van amerongen jp, penning c, ten cate jm. grey discolouration and marginal fracture for the diagnosis of secondary caries in molars with occlusal amalgam restorations: an in vitro study. caries res 1995;29:371-376. 38. hamilton, j.c. should a dental explorer be used to probe suspected carious lesions?yes – an explorer is a time-tested tool for caries detection. journal of the american dental association,2005; 136(11): 1526, 1528, 1530. 39. yang j, dutra v. utility of radiology, laser fluorescence, and transillumination. dental clinics of north america. 2005;49(4):739–752. 40. fejerskov o, kidd e. dental caries: the disease and its clinical management. 2nd edition. chapter 4. copenhagen, denmark: blackwell munksgaard; 2008. 41. marinova-takorova m, anastasova r, vladimir e. panov, spartak yanakiev. comparative evaluation of the effectiveness of three methods for proximal caries diagnosis – a clinical study . journal of imab annual proceeding (scientific papers). 2014; 20(1):514-516. 42. subka samiya . validity and acceptability of a laser fluorescence device compared to conventional methods for detection of proximal caries in primary teeth. 2015; 12(yh):0214. الخالصة لتقييم تقنية الفحص باستخدام األشعة التشخيصية والفحص عنن ريقنا الس ني انك العشنا عنن التثننو ال نا ن الهدف من هذه الدراسة كان الذ قظهي حنل حشنه األمسغم. السبنية ال قسنعة وتم الفحص باسنتخدام األشنعة التشخيصنية واسنتع ال حامنل الفسنم و يلتهنا عسن ستين من األسنان الدراسة استخدمت اك هذه الشاشة بدون تعبيي , وبعدها بناسطة الفحص عن ريقا الس ي باستخدام ال ثبار. http://www.ncbi.nlm.nih.gov/pubmed/?term=newman%20b%5bauthor%5d&cauthor=true&cauthor_uid=19228129 http://www.ncbi.nlm.nih.gov/pubmed/?term=seow%20wk%5bauthor%5d&cauthor=true&cauthor_uid=19228129 http://www.ncbi.nlm.nih.gov/pubmed/?term=kazoullis%20s%5bauthor%5d&cauthor=true&cauthor_uid=19228129 http://www.ncbi.nlm.nih.gov/pubmed/?term=ford%20d%5bauthor%5d&cauthor=true&cauthor_uid=19228129 http://www.ncbi.nlm.nih.gov/pubmed/?term=ford%20d%5bauthor%5d&cauthor=true&cauthor_uid=19228129 http://www.ncbi.nlm.nih.gov/pubmed/?term=holcombe%20t%5bauthor%5d&cauthor=true&cauthor_uid=19228129 http://www.ncbi.nlm.nih.gov/pubmed/19228129 http://www.ncbi.nlm.nih.gov/pubmed/19228129 j bagh college dentistry vol. 29(1), march 2017 assessment of pedodontics, orthodontics and preventive dentistry 198 والحثاسنية rocمنحنن ( ، وحثنا ال نطقنة تحنتrocبينت تائج هذه الدراسة لن لاضل قطة تقارع لسعينة تم الع نر عسيهنا منن بنل (. وبعد لقجاد هذه ال عسنمات لعل تقنية, تتم ال قار ة اي نا بينهنا باسنتخدام ااتبنار كننكيان d2( والعاج d1والننعية والد ة اك ربقة ال ينا طح اإلربنا واألسنطح لسكين. لظهيت تقنية الفحص عن ريقا الس ي بأ ها تقنية جيدة لسعشا عن التثنو ال ا ن عند ربقة ال ينا لعل من الجا بية من الفحص شعاعك. اك حين، كان الفحص شعاعك جيد ولاضل اك ربقة العاج من الفحص عن ريقا الس ي. اظهي الفحص عن ريقا الس ي لاضل تائج لسعشا عن التثنو ال ا ن اك ربقة ال ينا.اك حين لظهي الفحص الشعاعك عس لاضل تيجنة عن تثنو ال ا ن اك ربقة العاج. لسعشا dropbox 17 zahraa 92-97.pdf simplify your life 5. ammar f.doc j bagh college dentistry vol. 25(1), march 2013 effect of different restorative dentistry 27 effect of different acids surface treatments and thermocycling on shear bond strength of composite resin to feldspathic ceramic ammar a. lateef, b.d.s., m.sc. (1) abstract background: the aim of this study was to evaluate the effect of different surface acids treatments (37%phospjoric acid, 5%hydrofluoric acid, 1.23 acidulated phosphate fluoride) of feldspathic ceramic vita 3d master , and the effect of thermocycling on shear bond strength using a ceramic repair kit (ivoclar/vivadent). material and methods: sixty nickel-chromium metal base plates were prepared(9mm diameter,3mm depth) using lost wax technique, 2mm thick layer of ceramic(vita 3d master) fused to metal plates, all specimens were embedded in acrylic resin blocks except their examined surfaces and divided into 3 main groups 20 specimens each, grp a: treatment with 37%phosphoric acid for 2 mins, grp b: etching with 5% hydrofluoric acid for 2mins, grp c: etching with 1.23% acidulated phosphate fluoride for 10 mins; monobond-plus, heliobond, resin composite(tetric evoceram) were applied to each specimen according to manufacturer's instruction using transparent split mold(5mm diameter, 4 mm height); specimens were stored in 37oc distilled water for 12 weeks, 10 specimens of each group were subjected to thermocycling between 5 oc and 55 o c for 800 cycles with 30s dwell time; shear bond strength was determined by a universal testing machine (instron 1122) at a cross head speed 0.5mm/min; one way anova test, lsd test and student-t test were used to analyze shear bond strength. results: mean shear bond strength values for the tested groups were: a1= 11.65±0.68 mpa, a2=10.88±0.58 mpa, b1=17.93±0.41 mpa, b2=17.42±0.35 mpa, c1=15.17±0.61 mpa, c2=14.51±0.48 mpa ; one way anova test showed highly significant difference among groups; lsd test revealed that the use of 5% hf for ceramic surface treatment(gb) was highly significant than the treatment with 37%pa(ga) or 1.23%apf(gc) respectively and the use of 1.23%apf(gc) was highly significant than the use of 37%pa(ga); student ttest showed a significant difference between subgroups of the same group with and without thermocycling. conclusion: ceramic surface treated with 5% hf acid for 2 mins recorded the highest shear bond strength, followed by surface treatment with 1.23% apf for 10 mins, most specimens treated with 5%hf showed cohesive failure with in ceramic while specimens treated with 1.23%afp showed more (adhesive/cohesive) failure than adhesive or cohesive alone, and specimens treated with 37% pa showed nearly 50:50 adhesive and combination failure, thermocycling reduced the bond strength of each group significantly. key words: ceramic repair, different acids treatments, tetric evoceram, thermocycling, shear bond strength. (j bagh coll dentistry 2013; 25(1):27-33). introduction ceramic and metal-ceramic restorations have been used for several decades by clinicians to provide esthetics and masticatory function1. studies have shown various advantages of the ceramics, like color stability, radiopacity, coefficient of thermal expansion similar to that of dentin, good compressive and abrasive resistance, and esthetics2,3. however, dental materials and adhesive interfaces are subjected to stress in the oral environment: masticatory forces, temperatures changes, saliva and ph changes (4). moreover, trauma and fatigue can cause fracture of the ceramic or destroy the ceramic-metal bond3 because this restorative material has a low tensile strength and a high modulus of elasticity with a brittle behavior. problems such as a high treatment cost, possible trauma to the restored tooth, difficulty of removing the restorations, and patient demand for a rapid case resolution, may occasionally delay the replacement of a fractured metal-ceramic restoration (4), intraoral repair of fractured ceramic restorations with composite (1)assistant lecturer, department of operative dentistry, college of dentistry, university of baghdad. resin restorative materials presents a substantial challenge for clinicians (5), and is also a viable alternative for patients because these restorations are difficult to remove and very expensive to be replaced3.the type of composite resin also affect its bond strength to ceramic, hybrid type resins at the ceramic interface result in highter bond strength than those of microfilled composites6 numerous repair systems are available for recovering of ceramic fractures, the techniques include surface preparation of the ceramics and saline treatment in the bonding procedure5. these techniques involve air-particle abrasion of the surface with aluminum oxide, and etching the fractured part with different acids like phosphoric acid (pa), hydrofluoric (hf) acids and acidulated phosphate fluoride(apf) (7,8,9). it has been postulated that acid concentrations and etching times should be adjusted with specific ceramics to optimize bond strenght10 ,the bond strength of composite resin to aluminous porcelain was found to be inferior to that of feldspathic porcelain, hydrofluoric acid etching time has been reported to range from 60s to 20 mins (11,12,13), in addition difference in leucite concentration, j bagh college dentistry vol. 25(1), march 2013 effect of different restorative dentistry 28 size/orientation of crystals might affect etching times14,in the dental literature often the use of 510% hf acid has been recommended (15,16). recent study showed that there is non significant differences between specimens treated with5%hf and 10%,at the same etching time(2mins) (9) .apf gel, widely used for in-office fluoride application, consists of sodium fluoride, phosphoric acid, and hydrofluoric acid. it is safe for oral tissue, unlike hydrofluoric acid, which can produce tissue rash and burn (17). one recent study showed that 7-10 mins application of 1.23% apf gel on leucite containing porcelain produced a shear bond strength to composite similar to a 4 mins etch with 9.6%hf (18). it has been found that there is a significant difference between etching with hydrofluoric acid and phosphoric acid 40% for 60 s and advised the use of hf for mechanical retention and silane coupling agents for chemical retention (19, 20). the durability of bond values under the stresses of the oral environment is important for clinical predictability of dental materials. usually, dental materials are subjected to mechanical, thermal and chemical stresses in the mouth during functions. thermocycling and water storage in vitro is a common way for testing dental materials (21). the purpose of this study is to compare shear bond strength of composite to feldspathic ceramic using different acids surface treatment, 37%phosphoric acid for 2 mins,5% hydrofluoric acid for 2mins and 1.23% acidulated phosphate fluoride for 10 mins, and to evaluate the effect of thermocycling on the bond strength. materials and methods sixty nickel-chromium metal base plates (9mm diameter ,3 mm depth) were fabricated using lost wax technique, and a 2 mm thick layer of ceramic(vita 3d master ) fused to metal plates, to ensure even surfaces, specimens were wet grounded with a 320,400 and 600 grit silicon carbide cylinders(mounted stones, american dent-all inc, glendale ca). all specimens were embedded in acrylic resin blocks except their examind surfaces and divided into 3 main groups 20 specimens each, grp a: the surface of the ceramic treated with 37% phosphoric acid(pa) for 2 mins, grp b: the ceramic surface treated with 5% hydrofluoric acid(hf) for 2 mins9, grp c: the ceramic surface treated with 1.23% acidulated phosphate fluoride(apf) for 10 mins18, all specimens were rinsed with distilled water for 20s, ultrasonication in water bath for 2 mins and air dried for 30s18. for all specimens, following the manufacturer's directions one drop of monobondplus dispensed on a plastic dish, with the aid of disposable brush the solution applied to ceramic surface, allowed to set for 60s. subsequently a thin layer of heliobond applied homogenously with the aid of disposable brush, it serves as a bonding agent between the saline and the resin composite, the access material dispersed with oil free air and light cured for 10s. resin composite tetric evoceram (ivoclar/ vivadent liechtenstein) applied to each specimen according to manufacturer's instruction with the use of a plastic transparent split mold (5 mm diameter and 4 mm height) especially designed for this purpose. the composite resin introduced with plastic instrument into the mold and adapted to avoid air entrapment, the material carefully positioned over the ceramic surface and light cured for 20s from each side using radii plus led curing light (light intensity 1500 mw/cm2, curing depth 6mm, sdi). all specimens stored in 37ْc distilled water (dw) for 12 weeks22, 10 specimens from each group subjected to thermocycling between 5ْc and 55 ْ c for 800 cycles with 30s dwell time (thermocycling device alqaisi,iraq) . finally we got 6 groups: ga1: 10 specimens, ceramic surface treated with 37% pa 2mins, stored in distilled water, no thermocycling. ga2: the same as grp a1 with thermocycling. gb1: 10 specimens, ceramic surface treated with 5% hf 2 mins, stored in dw, no thermocycling. gb2: the same as grp b1 with thermocycling. gc1: 10 specimens, ceramic surface treated with 1.23% apf 10mins, stored in dw, no thermocycling. gc2: the same as grp c1with thermocycling. all specimens subjected to a shear load with a universal testing machine (instron 1122, england) with 0.5mm/min cross head speed, a chisel apparatus used to direct a parallel shearing force as close as possible to the composite/ceramic interface, shear load in newton at the point of failure noted, and calculated in mega pascal's. fracture sites examined using stereomicroscope to determine the location and type of failure during debonding23. mode of failure recorded as adhesive (failure at the ceramic-resin interface), cohesive (failure within the ceramic or the composite), or combination (areas of adhesive and cohesive failure). one-way analysis of variance (anova) was performed to test any statistically significant difference among the test groups. comparison between subgroups before and after thermocycling was performed by the least significant difference (lsd) test. j bagh college dentistry vol. 25(1), march 2013 effect of different restorative dentistry 29 results mean shear bond strength values, minimum, maximum and standard deviation values of the tested groups are shown in table 2. tables 3 and 5, showed that anova test's results revealed highly significant differences among nonthermocycled and among thermocycled groups respectively, further analysis using lsd tests was performed as shown in tables( 4 and 6) and the results revealed that for both non-thermocycled and thermocycled groups, specimens treated with 5% hydrofluoric acid showed significantly higher values than those treated with 37% phosphoric acid or 1.23% acidulated phosphate fluoride and specimens treated with 1.23%apf showed significantly higher values than those treated with 37% pa. for each acid group, ttest was performed between non-thermocycled and thermocycled subgroups, and the results exhibited that thermocycling had significantly reduced the shear strength values as shown in table 7. stereomicroscope examination showed that 70% of specimens treated with 5%hf exhibited cohesive failure with in ceramic, 70% of specimens treated with 1.23% apf showed (adhesive/cohesive)failure and 50% of specimens treated with 37% pa exhibited adhesive failure as shown in table 8. table 1: characteristics, composition and manufacturers of the material selected in the study manufacturer lotno. characteristics and composition materials eisenbacher dentalwaren ed gmbhgermany h09-16 (ni 61%, cr 25.05%, mo 12.35%, si 1.80%, mn 0.03%, c 0.01%) casting alloy v ita zahnfabrik germany bvmkset3d feldspathic ceramic vita 3d master india 90290 hydrofluoric acid 5% ivoclar/ vivadentliechtenstein germany n47997 phosphoric acid gel 37% deepak-usa 24-0867 acidulated phosphate fluoride gel 1.23% ivoclar/ vivadent liechtenstein germany n36909 light cured nano-hybrid composite, the monomer matrix is composed of dimethacrylates(17-18% weight), the fillers contain barium glass,ytterbium trifuoride, mixed oxide and prepolymers (82-83% w), the particles size between 40nm and 3000 nm with a m ean particle size of 550nm;additional content: additives, catalysts, stabilizers and pigments<1% w. tetric evoceram ivoclar/vivadent germany n51095 saline coupling agent, alcohol solution of silane methacrylate, phosphoric acid methacrylate and sulphide methacrylate. monobond plus ivoclar/vivadent germany n44963 light curing bonding agent contains bis-gma and triethylene glycol dimethacrylate(99 wt. %), catalysts and stabilizers<1%. heliobond sdi light intensity 1500 mw/cm2, curing depth 6mm. radii plus led curing light table 2: descriptive statistics n minimum maximum mean std. deviation a1 10 10.53 12.52 11.659 .68593 a2 10 10.08 11.81 10.8810 .58112 b1 10 17.26 18.43 17.9390 .41924 b2 10 16.90 17.92 17.4290 .35275 c1 10 14.15 16.17 15.1770 .61601 c2 10 13.84 15.22 14.5110 .48425 j bagh college dentistry vol. 25(1), march 2013 effect of different restorative dentistry 30 table 3: analysis of variance (anova) test for the effect of acid type on shear strength without thermocycling. (a1,b1,c1) sum of squares df mean square f sig. between groups 198.155 2 99.077 288.523 .000 within groups 9.272 27 .343 total 207.426 29 table 4: least significant difference (lsd) to compare shear strength values among groups (a1, b1, c1) 37% pa 2mins 5% hf 2mins 1.23% apf 10mins . 000(hs) .000(hs) .000(hs) table 5: analysis of variance (anova) test for the effect of acid type on shear strength with thermocycling (a2, b2, c2) sum of squares df mean square f sig. between groups 215.226 2 107.613 463.431 .000 within groups 6.270 27 .232 total 221.496 29 table 6: least significant difference (lsd) to compare shear strength values among groups (a2, b2, c2) 1.23 apf 10mins+ tc 5% hf 2mins +tc 37% pa 2mins+tc .000(hs) .000(hs) .000(hs) table 7: ttest for the effect of thermocycling for each acid group sig. p-value t-test groups s .014 2.737 a1&a2 hs .009 2.944 b1&b2 s .016 2.686 c1&c2 table 8: failure modes of the tested groups adhesive/cohesive cohesive with in ceramic cohesive with in composite adhesive groups 50% ------50% a1 70% ------30% a2 30% 70% ------------b1 30% 70% ------------b2 60% 30% ------10% c1 70% 20% ------10% c2 j bagh college dentistry vol. 25(1), march 2013 effect of different restorative dentistry 31 figure 1: shear bond strength testing figure 2: bar chart shows the differences in mean shear bond strength values (mpa) among groups. figure 3: cohesive failure within ceramic. figure 4: combination failure (adhesive/ cohesive). 0 2 4 6 8 10 12 14 16 18 20 group a1 group a2 group b1 group b2 group c1 group c2 shear strength ( mpa) groups j bagh college dentistry vol. 25(1), march 2013 effect of different restorative dentistry 32 figure 5. adhesive failure discussion intraoral repair of fractured porcelain restorations with composite resins presents a substantial challenge for dentists. multipurpose adhesive systems involve several treatment steps and agents were employed. in this study, lsd test results (table 4 and 6) showed that hf acid group produced statistically highly significant difference compared to apf and pa groups ; this was in agreement with other studies which showed that chemical etching with hf acid dissolves the glassy matrix selectively , the acidic ions of hydrofluoric acid penetrates into the si-o framework creating ten thousands microporosities/mm2 in a honey comb appearance to facilitate adhesion of composite resin to the porous surface of ceramic (24, 25). etching with apf even with prolonged time results in very shallow etching patterns when compared to hf etching for much shorter time periods (26, 27). regarding phosphoric acid it has a minimal effect on the ceramic surface and the bond strength mainly came from the effect of silane coupling agent which has the potential to react with the hydroxyl (-oh) groups present on the surface of porcelain via hydrogen bonding and then through a condensation polymerization (loss of water) reaction (28,29). in general the reduced shear bond strength values compared to other study done by (al-taie l.a., mohammed s.a. 2010) (9) could be attributed to prolonged water storage and thermo cycling , the hydrolytic degradation happens mainly because of accumulation of water between the filler-matrix that promotes the displacement of inorganic particles or due to the development of superficial flaws related to preexistent corrosive processes, it is believed that water sorption causes resin softening by swelling of the polymer network and decreasing of the frictional forces between the polymeric chains (22,30,31), exposing the specimens to thermocycling speeds up the diffusion of water in between the composite resin or ceramic, changing the temperature creates stress at the interface of the two materials because of different coefficients of thermal expansion accelerating their structural weakness, promoting union flaws, water storage and thermocycling are detrimental to the silaneceramic bond as well (32, 33), another factor that might have contributed to the decrease in adhesive resistance values was the sample dimension that had a small area, receiving larger influence of thermal cycling effects on its surface (34). with the result of this study, it can be concluded that surface treatment of felspathic ceramic with hydrofluoric acid gives the best repair bond strength, a second choice but inferior bond strength is the treatment with acidulated phosphate fluoride for a longer time. prolonged water storage time has an obvious effect in reducing the bond strength in relation to other studies; subgroups submitted to thermocycling have a significant decrease in bond strength in relation to other subgroups that have not been submitted to thermocycling; other studies are required to evaluate the effect of different surface treatment on other types of ceramics. referrences 1. appeldoorn re, wilwerding tm, barkmeier ww. bond strength of composite resin to porcelain with newer generation porcelain repair systems. j prosthet dent 1993; 70: 6-11. 2. pameijer ch, louw np, fischer d. repairing fractured porcelain: how surface preparation affects shear force resistance. j am dent assoc 1996; 127: 203-9. 3. matinlinna jp, vallittu pk. bonding of resin composites to etchable ceramic surfaces: an insight review of the chemical aspects on surface conditioning. j oral rehabil 2007; 34: 622-30. 4. santos jg, fonseca rg, adabo gl, dos santos cruz ca. shear bond strength of metal-ceramic repair systems. j prosthet dent 2006; 96:165-73. 5. kupiec ka, wuertz km, barkmeier ww, wilwerding tm. evaluation of porcelain surface treatments and agents for composite-to-porcelain repair. j prosthet dent 1996; 76: 119-24. 6. gregory wa, moss sm. effects of heterogeneous layers of composite and time on composite repair of porcelain. operative dentistry 1990; 15: 18. j bagh college dentistry vol. 25(1), march 2013 effect of different restorative dentistry 33 7. matsumura h, kato h, atsuta m. shear bond strength to feldspathic porcelain of two luting cements in combination with three surface treatments. j prosthet dent 1997; 78: 511-7. 8. blatz mb, sadan a, kern m. resin-ceramic bonding: a review of the literature. j prosthet dent 2003; 89: 268-74. 9. al-tai la, mohmmed sa. the effect of different acid porcelain surface treatments on composite-porcepain shear bond strength. j bagh college dentistry 2010; 22(4): 22-7. 10. calamia jr, simonsen rj. effect of coupling agents on bond strength of etched ceramics. j dental res 1984; 63: 179. 11. stangel i, nathanson d, hsu cs. shear strength of the composite bond to etched porcelain. j dent res 1987; 66: 1460-5. 12. al edris a, al jabr a, cooley rl, barghi n. sem evaluation of etch patterns by three etchants on three porcelains. j prosthet dent 1990; 64: 734-9. 13. barghi n, fischer de, vatani l. effects of porcelain leucite content, types of etchants, and etching time on porcelain-composite bond. j esthet restor dent 2006; 18:47-52. 14. jensen c. jensen industries. indirect personal communication via west b, frontier dental lab. 15. ozcan m. evaluation of alternative intraoral repair techniques for fractured ceramic-fused-to-metal restorations. j oral rehabil 2003; 30:194–203. 16. della bona a, anusavice kj, shen c. microtensile strength of composite bonded to hot-pressed ceramics. j adhes dent 2000; 2:305–13. 17. moore pa, manor rc. hydrofluoric acid burns. j prosthet dent 1982; 47: 338-9. 18. kukiattrakoon b, thammasitboon k. the effect of different etching times of acidulated phosphate fluoride gel on the shear bond strength of high-leucite ceramics bonded to composite resin. j prosthet dent 2007; 98:17-23. 19. lobell a, nicholls ji, kois jc, daly ch. () fatigue life of porcelain repair systems. int j prosthet 1992; 5: 205. 20. taro nagai, yoshikazu kawamoto. effect of hydrofluoric acid etching on bond strength of composite luting agent to lithium disilicate ceramic material. int chin j den 2004; 4: 100-106. 21. daniel o, auxiliadro m. study of thermocycling effect on bond strength between an aluminous ceramic and a resin cement. j appl oral sci 2005; 13(1): 53-7. 22. anjum a, matin k, et al. influence of aging on direct resin composite repair bond. int chin j dent 2008; 8: 53-61(ivsl). 23. kupiec ka, wuetz km. evaluation of porcelain surface treatment and agents for composite to porcelain repair. j prosthet dent 1996; 76: 119-124. 24. reston eg, filho sc, arossi g, et al. repairing ceramic restorations: final solution or alternative procedure? oper dent 2008; 33: 461-6. 25. tylka df, stewart gp. comparison of acidulated phosphate fluoride gel and hydrofluoric acid etchants for porcelain-composite repair. j prosthet dent 1994; 72: 121-7. 26. della bona a, van noort r. ceramic surface preparations for resin bonding. am j dent 1998; 11: 276-80. 27. canay s, hersek n, ertan a. effect of dirrerent acid treatments on a porcelain surface. j oral rehabli. 2001; 28: 95-101. 28. culler s. scotch prime ceramic primer product profile. 3m dental products.1985. 29. soderholm kj, shang sw. molecular orientation of silane at the surface of colloidal silica. j dent res 1993; 72: 1050-1054. 30. soderholm kj, mukherjee r, longmate j. filler leachability of composites stored in distilled water or artificial saliva. j dent res 1996; 9: 1692-9. 31. multu ozcan, luiz felipe, regina amaral. bond strength durability of a resin composite on a reinforced ceramic using various repair systems. dental materials 2009; 25: 1477-1483. (ivsl) 32. soderholm kj, robert mj. influence of water exposure on the tensile strength of composites. j dent res 1990; 69(12): 1460-5. 33. wegner sm, gerdes w, kern m. effect of different artificial aging conditions on ceramic-composite bond strength. int j prosthodont 2002; 15(3): 267-72. 34. shono y, terashita m, shimada j. durability of resindentin bonds. j adhes dent 1999; 1(3): 211-8. noor f.doc j bagh college dentistry vol. 25(4), december 2013 effect of orthodontic tooth 120 pedodontics, orthodontics and preventive dentistry effect of orthodontic tooth movement on salivary levels of interleukin-1beta, tumor necrosis factor-alpha, and c reactive protein noor saadi, b.d.s. (1) nidhal h. ghaib, b.d.s., m.sc. (2) abstract background: orthodontic force is considered to stimulate cells in the periodontium to release many mediators such as cytokines which play a responsible role for periodontal and alveolar bone remodeling, bone resorption and new bone deposition. aim of this study was carried out to estimate changes of the (interleukin-one beta, tumor necrosis factor – alpha and c-reactive protein) levels in unstimulated whole saliva during the leveling stage of orthodontic tooth movement. materials and methods: the sample consisted of thirty adult patients (12 males and 18 females) with ages ranges (1923) years. each sample had class i and class ii malocclusion dental classification and required bilateral extraction of their maxillary first premolars, underwent a session of professional oral hygiene and received oral hygiene instructions before and during the period of study, one month later fixed orthodontic appliance were placed in the upper arch by using 0.014 nickel titanium arch wire. the unstimulated whole saliva was taken from each sample immediately before placement of the appliance (baseline), and at (after1hour, after one week and after two week) following placement of the fixed orthodontic appliance. in addition the plaque index and gingival index were recorded during the interval periods of this study to assess oral cleanliness. the interleukin – one beta and tumor necrosis factoralpha were determined by enzyme linked immunosorbent assay, while the c-reactive protein was determined by latex agglutination. results: the results of the present study found the mean value of both salivary (interleukin-one beta and tumor necrosis factor -alpha) were highest at (after1hour) followed by at (after one week) then at (after two week) than the baseline with highly statistical significant differences (p< 0.01) among males, females and total samples, in addition there were no statistical significant differences between males and females (p>0.05). while the mean values of c-reactive protein were higher at (after 1hour) only with highly significant differences (p< 0.01) among females and total samples while only significant difference (p<0.05) for males, in addition there were no statistical significant differences between males and females. regarding the correlation between salivary (interleukin – one beta and tumor necrosis factor -alpha), there were positive correlation between them at all periods of study. moreover there were positive correlation between salivary (interleukin – one beta and tumor necrosis factor -alpha) and salivary creactive protein. on the other hand there were no association between the salivary (interleukin – one beta and tumor necrosis factor -alpha and c-reactive protein) and clinical parameter (plaque index and gingival index). conclusion: from this clinical study we conclude that orthodontic force induces increasing the levels of (interleukin – one beta, tumor necrosis factor -alpha, c-reactive protein) in unstimulated whole saliva during orthodontic tooth movement. keywords: interleukin-one beta, tumor necrosis factor – alpha, c-reactive protein, unstimulated saliva, orthodontic tooth movement. (j bagh coll dentistry 2013; 25(4):120-125). introduction orthodontic tooth movement is based on force that stimulate periodontal ligaments and alveolar bone remodeling, at the early stage of orthodontic tooth movement, the host response to orthodontic force has been described as an aseptically and transitory inflammation characterized by alteration the vascularity and blood flow of periodontal ligament (pdl), resulting in local synthesis and release of different mediators such as cytokines (il-1β, tnf-α, etc.) involved in alveolar bone remodeling process (14).importantly, il-1β is pro-inflammatory cytokines produced by the periodontal ligament (pdl) in sufficient quantities to diffuse into the gingival crevicular fluid (gcf) and has been identified as a biomarker of orthodontic tooth movement (5-8). (1)master student. department of orthodontics. college of dentistry. university of baghdad (2)professor. department of orthodontics. college of dentistry. university of baghdad tnf-α is a typical mediator of inflammatory response that has been shown to be involved in the process of bone resorption and to be locally elevated in response to orthodontic force. it plays a prominent role in the mechanism controlling the appearance of osteoclasts at compression sites (814). furthermore cytokines such as (il-1β and tnf-α) produced at the gingival sites may be transported into the systemic circulation and stimulate hepatocytes in the liver to produce c – reactive protein (crp), which provide a biomarker for low grad systemic inflammation (1519).inflammatory cytokines such as il-1β and tnf-α which are involved in bone and periodontal remodeling, have been quantified in the salivary crevicular fluid of patients undergoing orthodontic treatment (7-8,11,20). different mediators involved in alveolar bone remodeling are continuously washed into saliva by gcf, whole-saliva samples may constitute an easy alternative to individual gingival sulcular j bagh college dentistry vol. 25(4), december 2013 effect of orthodontic tooth 121 pedodontics, orthodontics and preventive dentistry samples for determining analytes of bone turnover that are present within the periodontal environment, providing a sensitive and inexpensive detection technique (21). aim of this study was carried out to estimate changes of the (interleukin-one beta, tumor necrosis factor – alpha and c-reactive protein) levels in unstimulated whole saliva during the leveling stage of orthodontic tooth movement. material and methods subjects recruited for the study were volunteer patients attending the orthodontic department at the college of dentistry university of baghdad seeking for orthodontic treatment. a total of 30 adult patients (12 males and 18 females) with an age range of (19-23 years) were participated in the study. they should be with class i and /or class ii malocclusion cases requiring bilateral extraction of their maxillary first premolar teeth. each subject prior the placement of the orthodontic appliance should extracted both upper first premolars (right and left) at least 20 days. during this period, all the subjects should be with good oral hygiene(22). the collection of the unstimulated salivary samples from the individuals was formed under standardized conditions(23-24). in the current study saliva collected between 9-12 am at different times; before placement of the orthodontic appliance(1hour) as a baseline (t0), then 1 hour after placement of orthodontic appliance (t1), one week (t2), two week (t3). the samples were stored at -20ºc in a deep freeze until processed (25). this assay employs the quantitative sandwich enzyme immunoassay technique. antibody specific for il-1β has been pre-coated onto a microplate. standards and samples were pipetted in to the wells and any il-1β present was bound by the immobilized antibody. after removing any unbound substances, a biotin-conjugated antibody specific for il-1β was added to the wells. after washing, avidin conjugated horseradish peroxidase (hrp) was added to the wells. following a washed to remove any unbounded avidin-enzyme reagent, a substrate solution was added to the wells and color develops in proportion to the amount of il-1β bound in the initial step. the color development was stopped and the intensity of the color was measured. creactive protein in saliva was detected by using latex agglutination slide test (human tex crp) for the qualitative and semi-quantitative determination of c-reactive protein in non diluted saliva. principle: human tex crp was based on the immunological reaction between human creactive protein (crp) of patient specimen or control serum and the corresponding antihuman crp antibodies bound to latex particles. the positive reaction is indicated by distinctly visible agglutination of the latex particles in the test cell of the slide.all data analyses were performed using the spss statistical software program (version 10 for windows, spss). the confidence level was accepted at the level of 5%. results results showed that the mean value of salivary il-1β (pg/ml) and tnf-α (pg/ml) were highest at t1, followed by t2, then t3 and then t0 with highly statistically significant difference (p< 0.01) among males, females, and total sample as shown in (table 1) and (table 2) respectively .according the t-test, the mean value of salivary il-1β (pg/ml) among males was higher than females with no statistically significant difference (p > 0.05) at t0, t1, t2, and t3. the same results was recorded concerning tnf-α (pg/ml). table 1. mean of il-1β concentration (pg/ml) among samples no significant= p value > 0.05. ٭(significant)= p value < 0.05. ٭٭) highly significant)= p value < 0.01. j bagh college dentistry vol. 25(4), december 2013 effect of orthodontic tooth 122 pedodontics, orthodontics and preventive dentistry table 2. mean of tnf-α concentration (pg/ml) among samples: non significant= p value > 0.05. ٭(significant)= p value < 0.05. ٭٭(highly significant)= p value < 0.01. as demonstrated in (table 3)the mean value of salivary crp (mg/l) was highly at the t1 with highly statistically significant difference (p< 0.01) among females and total sample and only significant difference (p<0.05) for males. the present study reported the normal of salivary crp at the period (t0, t2, and t3) for both males and females. according to t-test, the mean value of salivary tnf-α (pg/ml) among females was higher than males with no statistically significant difference (p > 0.05) at t1. table 3. mean of crp concentration (mg/l) among samples no significant= p value > 0.05. ٭(significant)= p value < 0.05. ٭٭(highly significant)= p value < 0.01. table (4) showed the correlation coefficient between il-1β and tnf-α at t0, t1, t2 and t3. concerning t0, the relation between il-1β and tnf-α was highly significant correlation in positive direction for the total sample, males and females (p <0.01). similar findings were reported among t1, t2 and t3. table 4. correlation coefficient (r) between means of il-1β and tnf-α among samples il-1β and tnf-α baseline (t0) after 1hour (t1) after 1 week (t2) after 2 week (t3) gender no. r p-value r p-value r p-value r p-value males 12 0.95 0.00٭٭0.00 0.89 ٭٭0.00 0.89 ٭٭0.00 0.83 ٭٭ females 18 0.95 0.00٭٭0.00 0.92 ٭٭0.00 0.94 ٭٭0.00 0.75 ٭٭ total 30 0.90 0.00٭٭0.00 0.87 ٭٭0.00 0.89 ٭٭0.00 0.73 ٭٭ .(highly significant = p value < 0.01) ٭٭ table (5) showed the correlation coefficient between il-1β and crp at t0, t1, t2 and t3. concerning t0, t2, and t3, the data of the present study showed absence of correlation between il-1β and crp. concerning at t1, the relation between il-1β and crp was highly significant correlation in positive direction for the total sample (p <0.01). while among males and females the relation between il-1β and crp was significant corelation in positive direction (p <0.05). table (6) reported the correlation coefficient between tnf-α and crp at t0, t1, t2 and t3. concerning the t0, t2 and t3, the data of the present study showed absence of correlation between tnf-α and crp. concerning time (t1), the relation between tnf-α and crp was highly significant correlation in positive direction for the total sample (p <0.01), similarly the relation between tnf-α and crp was highly significant in positive direction for the females (p <0.01), while for the males the relation between tnf-α and crp was significant correlation in positive direction (p <0.05). j bagh college dentistry vol. 25(4), december 2013 effect of orthodontic tooth 123 pedodontics, orthodontics and preventive dentistry table 5. correlation coefficient (r) between means of il-1β and crp among samples il-1β and crp baseline (t0) after 1hour (t1) after 1 week (t2) after 2 week (t3) gender no. r p-value r p-value r p-value r p-value males 12 . 0.69 0.01٭ . . females 18 . 0.61 0.01٭ . . total 30 . 0.60 0.00٭٭ . . .p value < 0.01 = (highly significant correlation)٭٭ .p value < 0.05 = (significant correlation)٭ table 6. correlation coefficient (r) between means of tnf-α and crp among samples tnf-α and crp baseline (t0) after 1hour(t1) after 1 week (t2) after 2 week (t3) gender no. r p-value r p-value r p-value r p-value males 12 . 0.69 0.01٭ . . females 18 . 0.77 0.00٭٭ . . total 30 . 0.62 0.00٭٭ . . .p value < 0.01 = (highly significant correlation)٭٭ .p value < 0.05 = (significant correlation)٭ discussion orthodontic tooth movement is a biological process of bone remodeling, involving an acute inflammatory response in the periodontal tissues, characterized by increasing in vascular permeability and cellular infiltration of leukocytes (2, 13). some cytokines such as il-1β, tnf-α play important role in regulation of bone remodeling during orthodontic tooth movement, through recruitment of osteoclast precursors from the circulation, maturation and activation, in addition they promote osteoclast formation and activation (26-28). the result of the present study showed that the mean value of salivary level il-1β and tnf-α were elevated to reach the peak at t1 following placement of the orthodontic appliance during the study periods followed by declined at t2 then t3. this elevation at the 1 hour might be caused by an early upregulation of chemotactic activities directly after continuous mechanical force application and this in agreement with previous findings (5,7-8,29-30). while disagreement with other studies (6,31) who were demonstrating no change in the il-1β and tnf-α at the (1hour) in the gcf in orthodontic tooth movement, this may be due to the variations in the study design, and these differences exist in terms of sample size, patients’ gender, age and salivary sample type, when many of these studies did not included these factors in the multivariate analysis. concerning to the declining the level of the cytokines at the t2 and t3 of this study might be to the activity of the antiinflammatory cytokines such as il-10 which is known immune regulatory functions, including suppression of the proinflamatory cytokines and stimulation that play a role in bone resorption and periodontal tissue destruction (32). the present study found no significant differences between males and females, this in agreement with serra et al. (33) who found no differences in enzymztic activity during orthodontic tooth movement between males and females. the result of the present study revealed synergistically correlation between the il-1β and tnf-α at all the period times of this study (t0, t1, t2, and t3), this in agreement with dinarello (34). several studies found that salivary crp may largely reflect local inflammation in the mouth (3536), adapted to these studies the salivary level of crp were measured in the present study. the results of this study illustrated the highest level of the crp at the (t1) with non-significant differences between males and females. concerning to the correlation between (il-1β and crp) and (tnf-α and crp), there were significant correlation in positive direction at the (t1), this can be rationalize by the transport of the cytokines (il-1β and tnf-α) from the gingival sites into the systemic circulation which stimulate the hepatocytes in the liver to produce crp and increase their level, this in agreement with the previous studies (15-17). the normal of the crp at the t0 indicated that the patients involved in this study were healthy. in additional, normal of the crp at the t2 and t3 can be rationalized by decreasing and cease the stimulation effect of the bone resorption, this in agreement with haheim (37) who demonstrated that the production of crp related to the stimulation, that the level of crp falls rapidly when the stimulation is ceased. the result of the present study shown no significant differences between males and females; this j bagh college dentistry vol. 25(4), december 2013 effect of orthodontic tooth 124 pedodontics, orthodontics and preventive dentistry finding come in agreement with the finding of serra et al. 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(1) hadeel a. al-hashimi, b.d.s., m.sc. (2) abstract background: orthodontic mini-implants are increasingly used in orthodontics and the bone density is a very important factor in stabilization and success of mini-implant. the aim of this study was to observe the relationship among maximum bite force (mbf); body mass index (bmi); face width, height and type; and bone density in an attempt to predict bone density from these variables to eliminate the need for ct scan which have a highly hazard on patient. materials and methods: computed tomographic (ct) images were obtained for 70 patients (24 males and 46 females) with age range 18-30 years. the maxillary and mandibular buccal cortical and cancellous bone densities were measured between 2nd premolar and 1st molar at two levels from the alveolar crest (3 and 6 mm). face height and width were measured from ct. clinically; maximum bite force was measured on first molar region unilaterally by a digital device. the sample was divided into two groups according to the body mass index into; normal and overweight. results: the results obtained showed that there were no statistical significant differences in mbf or bone density in both genders. only the cortical bone density in maxilla in overweight group tended to be higher than normal bmi group. the face width and height correlated significantly negatively with mbf which correlated significantly positively with cortical bone density. conclusions: it was concluded that a prediction of cortical bone density of preselected areas can be made from maximum bite force, body mass index and inter-zygomatic width. key words: bone density, bite force, computerized tomography, orthodontic mini-implant. (j bagh coll dentistry 2015; 27(4):161-167). introduction much of the success of orthodontic treatment depends upon careful anchorage preparation (1). concerning density of the alveolar bone are essential for selecting sites for mini-implant placement and predicting success (2). the size of an individual (weight and height) may play an important role in the size, thickness and density of the bone (3); on the other hand a positive correlation was found between bite force and body height and weight (4). the growth facial pattern has an influence on the morphology of labial/buccal and lingual bone plates (5,6). the subjects in the hyperdivergent group had significantly lower bone densities on the buccal side than hypodivergent subjects for both sex (7). bite force also varies with different facial profiles. it is greater in adults with a rectangular craniofacial morphology and skeletal deep bite than in those who have a long face and open bite (8). progressive bone loading changes the amount and density of bone, the bone is given time to respond to gradual increase in occlusal load. this increases the quantity of bone and improves bone density (9). (1)master student. department of orthodontics, college of dentistry, university of baghdad. (2)assistant professor, department of orthodontics, college of dentistry, university of baghdad. wherefore, the knowledge of how the body mass index, maximum bite force, and facial types, affecting on the bone mineral density (bmd) were considered in this study in an attempt to predict bmd from related variables. materials and methods sample: the sample of the present study was selected from the patients who were attending the computerized tomography department in al karkh general hospital in baghdad. only 70 patients (24 males and 46 females with an age range from 18 to 30 years) who met following special criteria were selected. 1no history of systemic disease and no previous chronic use of any medication that could affect bone density. 2no history of previous orthodontic treatment and/or orthognathic surgery. 3no regular smoking and/or alcohol consumption. 4no clear facial asymmetry and no history of previous facial trauma assessed by visual examination. 5no tmj problem by clinical examination. 6skeletal and dental class i. the following criteria were considered in selected side: j bagh college dentistry vol. 27(4), december 2015 a clinical method pedodontics, orthodontics and preventive dentistry 162 a. no missing teeth excluded 3rd molar. b. well aligned teeth with no cross bite, rotation, spacing or crowding more than 2 mm (10). c. no massive carious lesions and/or filling restorations and no teeth wearing. d. no pathological lesion in the examined area which determined by clinical and radiographic examination (ct). e. no pathological periodontal problem according to the gingival index and no alveolar bone loss from ct. method: patients were informed about the aims and objectives of the study. for each patient, the agreement to participate in this study was taken during his/her ct scan appointment. bmi measurement: it's measured by dividing weight (kg)/height2 (m2). bite force registration: maximum bite force was measured using bite force measuring device (gm10; nagano keiki company, ltd tokyo, japan) (figure 1); the device consisted of hydraulic pressure gauge and a biting element made of a vinyl material encased in a plastic tube called disposable occlusal cap that will be replaced for each subject; by putting the device between upper and lower first permanent molars unilaterally in the left side or right side (the side fulfill the inclusion criteria) and the subject was asked to bite firmly for a few seconds as much as he/she can until the maximum bite force was obtained then the bite force was calculated in newton and displayed digitally. this bite measurement was repeated three times with 2-3 minutes interval between records, and the highest value was registered. figure (1): occlusal force-meter gm10. computerize tomography (ct) scan measurements were taken as following: • measurement of anb angle: for further assurance that the selected subject was skeletal class i, anb angle was measured according to steiner (11) by using the cephalometric option. • measurement of bone loss: alveolar bone crest level was measured in 3 dimensions facial bone (skull).the alveolar crest should be slightly apical to the cementoenamel junction (cej) by approximately 1.5 to 2 mm (12). • measurement of bone density: bone density was measured in the axial view in mid-way between 2nd premolar and 1st molar in the selected side (left or right). bone density of the alveolar bone was measured at two levels from the alveolar crest (3 and 6 mm) for the buccal cortical and cancellous bones in both jaws. the measurement of buccal cortical bone density was made in the center point of its thickness. the measurement of cancellous bone density was made at the trabeculae, located halfway buccolingually between the buccal and palatal/lingual cortical plates (13). densities of the bone were measured in hounsfield units (hu). • measurement of facial type: facial types were measured in 3dimensions facial bone (skull) by measuring facial height(distance between the point nasion and menton in bone) and facial width (inter-zygomatic distance) (figure 2).the facial typeswere determined according to the facial index which was calculated by dividing facial height *100/ facial width (14). figure (2): measurement of facial height and width. results the measurements of bone density were considered the principle outcome variable in the current study, other variables being used to predict this outcome. the face dimensions which include face height and width were considered instead of face type since the entire sample has normal face. the bone density at two preselected points (3 and 6 mm) in each jaw was combined and the average of them was used, table 1 showed that there were no statistically significant gender differences in bite force and bone density. based on this result, both gender groups were combined. the samples of present study were including normal and overweight categories of the international classification of bmi(15). table 2 showed that there were no statistically significant bmi differences in bite force. regarding to bone j bagh college dentistry vol. 27(4), december 2015 a clinical method pedodontics, orthodontics and preventive dentistry 163 density, only the cortical bone density in maxilla shows a statistical significant difference. table 3 showed that the relationship of face width and height with mbf was negatively significant. table 4 showed that the relationship of the bone density of cortical bone in the maxilla and mandible had a statistically significant relation with mbf while the cancellous bone had not. the bone density (cortical and cancellous) in the maxilla and mandible with face dimensions (height and width) was statistically nonsignificant. to study the net and independent effect of gender, bmi, mbf, face length and width on cortical bone density in maxilla and mandible, a multiple linear regression model was used. a forward step inclusion algorithm was used to select among the suggested explanatory variables only those that significantly affect cortical bone density in maxilla and mandible. v maxilla (table 5) the final prediction model was based on a combination of mbf, bmi and face width. this model explains 21.9% of observed variation in the outcome variable (bone density). mbf, bmi and face width had a statistically significant direct linear association with cortical bone density. cortical bone density is expected to increase for each variable after adjusting (controlling for the confounding effect of other explanatory variable included in model). for each 1(n) increase in mbf, the cortical bone density in maxilla is expected to increase by 0.5 (hu). for each 1(kg/m2) increase in bmi, the cortical bone density in maxilla is expected to increase by 14.3 (hu). for each 1(mm) increase in face width, the cortical bone density in maxilla is expected to increase by 4.2 (hu). finally, depending on the equation below we can predict the cortical bone density in maxilla. y = -33.1+(0.5*mbf)+(14.3*bmi)+(4.2*face width) v mandible (table 6) the final prediction model was based on mbf only. this model explains 9.6% of observed variation in the outcome variable (bone density). mbf had a statistically significant direct linear association with cortical bone density. for each 1(n) increase in mbf, the cortical bone density in mandible is expected to increase by 0.51 (hu), so depending on the equation below, we can predict the cortical bone density in mandible. y=1069.6+ (0.51*mbf) y = cortical bone density. table (1): gender differences of bite force (n) and bone density (hu) (cortical and cancellous) in maxilla and mandible. variables total samples (n=70) n range mean sd se p-value mbf ♂ 24 182-587 326.7 111.6 22.8 0.92 [ns] ♀ 46 122-513 324.0 112.3 16.6 m ax ill a cortical bmd ♂ 24 823-1327 d3-d1 1030.7 d2 116.0 23.7 0.26 [ns] ♀ 46 570-1347 d3-d1 985.8 d2 175.5 25.9 cancellous bmd ♂ 24 142-408 d5-d3 283.2 d4 83.9 17.1 0.13 [ns] ♀ 46 119-458 d5-d3 251.4 d4 82.2 12.1 m an di bl e cortical bmd ♂ 24 1039-1513 d2-d1 1283.0 d1 156.3 31.9 0.11 [ns] ♀ 46 784-1614 d3-d1 1209.7 d2 191.5 28.2 cancellous bmd ♂ 24 157-449 d4-d3 290.8 d4 92.6 18.9 0.25 [ns] ♀ 46 149-458 d5-d3 265.2 d4 84.8 12.5 j bagh college dentistry vol. 27(4), december 2015 a clinical method pedodontics, orthodontics and preventive dentistry 164 table (2): bmi differences of bite force (n) and bone density (hu) (cortical and cancellous) in maxilla and mandible. variables bmi total samples (n=70) n range mean sd se p-value mbf normal 43 140-587 329.6 114.5 17.5 0.66 [ns] overweight 27 122-490 317.4 107.6 20.7 m ax ill a cortical bmd normal 43 570-1241 d3-d2 971.5 d2 147.0 22.4 0.046 [s] overweight 27 727-1347 d3-d1 1048.6 d2 166.5 32.0 cancellous bmd normal 43 121-419 d5-d3 261.2 d4 79.7 12.2 0.89 [ns] overweight 27 119-458 d5-d3 264.1 d4 91.0 17.5 m an di bl e cortical bmd normal 43 784-1513 d3-d1 1209.3 d2 168.5 25.7 0.14 [ns] overweight 27 880-1614 d2-d1 1275.5 d1 199.1 38.3 cancellous bmd normal 43 154-449 d4-d3 271.3 d4 74.8 11.4 0.75 [ns] overweight 27 149-458 d5-d3 278.3 d4 106.5 20.5 table (3): relationship of mbf (n) with face dimensions (mm). variables mbf total samples (n=70) anova trend n range mean sd se p-value f ac e h ei gh t lowest quartile≤100.9 18 218-499 374.7 88.0 20.7 0.011 [s] interquartile range 101.0 111.5 36 122-587 321.0 118.1 19.7 highest quartile≥111.6 16 171-490 277.6 101.0 25.3 f ac e w id th lowest quartile ≤116.2 18 146-499 365.0 100.9 23.8 0.044 [s] interquartile range 116.3 126.7 35 129-587 321.7 109.6 18.5 highest quartile≥126.8 17 122-513 288.9 117.6 28.5 discussion mbf was measured in the 1st molar region since it is typically obtained in the 1st molar area (16) as the 1st permanent molar is the largest tooth in maxillary and mandibular arch (17), and its position is considered as a key and fulcrum of functional occlusion (18). the measured points were preselected to be at 3 and 6 mm from alveolar crest in order to be in the alveolar bone since it was more favorable for mini-implant success than free mucosa (19). the area of the alveolar bone between 2nd premolars and 1st molars in maxilla was preselected to measure the bone density since it is the most proper area for insertion of mini-implant (20). the same area was preselected in the mandible for standardization. attention was not paid to the side because previous studies demonstrated no significant side differences regarding bite force (21,22), and the bone density (13,23,24). in the present study there were no statistically significant gender differences in bite force and bone density. this result can be attributed to the occlusal force gauge used in this study and since males and females eat essentially the same types of food, the strain produced during mastication might be expected to be similar, as would bone density. this result is in agreement with chun and lim (25) and palinkas et,al.,(26) and in disagreement with others (21,27,28) who found males were present higher maximum bite force than females. furthermore, this result regarding bone density comes in accordance with others (13,24). it can be reflected clinically by previous studies that found no differences in the success rate and stability of mini implants between male and female subjects(29,30). j bagh college dentistry vol. 27(4), december 2015 a clinical method pedodontics, orthodontics and preventive dentistry 165 table (4): relationship of bone density in maxilla and mandible (hu) with mbf (n) and face dimensions (mm). variables n cortical bone density pvalue cancellous bone density p-value range mean sd se range mean sd se m ax ill a m b f lowest quartile ≤213 18 708-1327 d3-d1 909.1 d2 155.3 36.6 0.02 [s] 119-368 d5-d3 241.3 d4 77.4 18.2 0.57 [ns] interquartile range 232-413 36 570-1301 d3-d1 1031.4 d2 157.8 26.3 148-458 d5-d3 274.9 d4 83.3 13.9 highest quartile ≥ 414 16 828-1347 d3-d1 1036.9 d2 126.4 31.6 121-383 d5-d3 257.6 d4 90.7 22.7 f ac e h ei gh t lowest quartile≤100.9 18 635-1301 d3-d1 995.1 d2 170.5 40.2 0.76 [ns] 142-458 d5-d3 264.7 d4 84.0 19.8 0.85 [ns] interquartile range 101.0 111.5 35 570-1327 d3-d1 999.4 d2 157.0 26.2 119-419 d5-d3 257.6 d4 91.8 15.3 highest quartile ≥111.6 17 770-1347 d3-d1 1012.2 d2 156.7 39.2 168408d4d3 270.2 d4 66.0 16.5 f ac e w id th lowest quartile ≤116.2 18 635-1301 d3d1 985.2 d2 179.4 42.3 0.78 [ns] 142-458 d5-d3 267.6 d4 80.9 19.1 0.78 [ns] interquartile range 116.3 126.7 35 570-1347 d3 – d1 1009.7 d2 162.6 27.5 119-419 d5-d3 261.1 d4 92.8 15.7 highest quartile ≥126.8 17 7701168d3d2 1000.6 d2 131.0 31.8 121-408 d5-d3 259.2 d4 69.6 16.9 m an di bl e m b f lowest quartile ≤213 18 784-1487 d3-d1 1128.3 d2 198.7 46.8 0.009 [hs] 149 439 d5-d3 267.9 d4 94.9 22.4 0.25 [ns] interquartile range 232-413 36 880-1614 d3-d1 1263.9 d1 153.8 25.6 157 449 d4-d3 264.3 d4 75.0 12.5 highest quartile ≥ 414 16 1039-1609 d2-d1 1289.2 d1 185.3 46.3 154 458 d4-d3 302.5 d4 104.6 26.2 f ac e h ei gh t lowest quartile≤100.9 18 863-1614 d2-d1 1229.4 d2 165.7 39.0 0.71 [ns] 154 430 d4-d3 291.8 d4 92.9 21.9 0.92 [ns] interquartile range 101.0 111.5 35 880-1513 d2-d1 1229.2 d2 178.4 29.7 159 449 d4-d3 258.4 d4 75.5 12.6 highest quartile≥111.6 17 784-1609 d3-d1 1253.5 d1 217.3 54.3 149 458 d5-d3 288.9 d4 105.5 26.4 f ac e w id th lowest quartile ≤116.2 18 863-1614 d2-d1 1205.0 d2 172.4 40.6 0.99 [ns] 154 430 d4-d3 298.3 d4 86.8 20.5 0.99 [ns] interquartile range 116.3 126.7 35 880-1609 d2-d1 1264.1 d1 182.4 30.8 157 449 d4-d3 257.2 d4 79.6 13.5 highest quartile ≥126.8 17 784-1527 d3-d1 1206.1 d2 193.6 47.0 149 458 d5-d3 282.6 d4 101.8 24.7 table (5): prediction of cortical bone density of maxilla. variables partial regression coefficient p-value constant -33.1 0.91 [ns] mbf(n) 0.5 0.002 [hs] bmi(kg/m2) 14.3 0.015 [s] face width (mm) 4.2 0.32[s] table (6): prediction of cortical bone density of mandible. variables partial regression coefficient p-value constant 1069.6 0.001[hs] mbf(n) 0.51 0.009 [hs] j bagh college dentistry vol. 27(4), december 2015 a clinical method pedodontics, orthodontics and preventive dentistry 166 it was found that there were no statistically significant bmi differences in bite force and this result agree with others (8,22,31-33). the relationship of the cortical bone density of maxilla with bmi was statistically significant, while of mandible was not. this may be explained as the masseter muscle thickness was found to be positively correlated to bmi (34). furthermore, muscle weight is an important determinant of bone mass because the weight of a muscle reflects the forces that it exerts on bones to which it is attached (35) and since the maxilla is the fixed bone, so the cortical bone of maxilla is logically more affected than the mandibular one. for the relationship of face width and height with mbf it was negatively significant. this may be explained as any increase in the width and height of face may be associated with an increase in surface area to which that force is distributed, but not necessarily associated with an increase in the occlusal contact area which is considered as the key determinant affecting bite force. furthermore, the masticatory muscles of subjects with increase height of face were less efficient in generating bite force at a particular point on the lever arm(36), and the size of masseter muscle also decreased, and since bite force magnitude depends on the size of the masseter muscle, the lever arm lengths of bite force and muscle forces (37). for the relationship of bone density (cortical and cancellous) in the maxilla and mandible with face dimensions (height and width) was statistically non-significant. since the sample of the present study included normal face only, so this may explain these results. on the other hand, the density of cortical bone in the maxilla and mandible had a statistically significant relation with mbf, as with increasing mbf, the cortical bone density increase, 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(ivsl) j bagh college dentistry vol. 27(4), december 2015 a clinical method pedodontics, orthodontics and preventive dentistry 167 14. martin r, saller k. lehrbuch der anthropologie. gustav fischer verlag, stuttgart, 1957. 15. who. global database on body mass index an interactive surveillance tool for monitoring nutrition transition, 2014. 16. carlsson ge. bite force and chewing efficiency. in: kawamura y (ed.). front oral physiology of mastication. basel: karger; 1974. p. 265−92. 17. black s, scheuer l. the juvenile skeleton. st. louis: elsevier academic press; 2004, p.162. 18. risse g. contradictory doctrines of functional anatomy, of the masticatory organ, occlusion and tooth angulation. xix international congress, aig, 1st congress of iaaid, gnathology part ii 2007. institute of bio functional orthodontics (ibo) germany. 19. kuroda s, sugawara y, deguchi t, kyung hm, takano-yamamoto t. clinical use of miniscrew implant as orthodontic anchorage: success rate and postoperative discomfort. am j orthod dentofac 2007; 131: 9–15. 20. park hs, kwon tg. sliding mechanics with microscrew implant anchorage. angle orthod 2004; 74: 703-10. 21. ferrario vf, sforza c, serrao g, dellavia c, tartaglia gm. single tooth bite forces in healthy young adults. j oral rehabil 2004; 31(1): 18-22. 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(ivsl) 35. doyle f, brown j, lachance c. relation between bone mass and muscle weight. the lancet 1970; 295(7643): 391–3. 36. garcia-morales p, buschang ph, throckmorton gs. maximum bite force, muscle efficiency and mechanical advantage in children with vertical growth patterns. eur j orthod 2003; 25: 265–72. 37. raadsheer mc, van eijden tmg j, van ginkel fc, prahl-andersen b. contribution of jaw muscle size and craniofacial morphology to human bite force magnitude. j dent res 1999; 78: 31–42. 38. clarke b. normal bone anatomy and physiology. clin j am soc nephrol 2008; 33 (4 suppl): s131-9. 39. okumura n, stegaroiu r, kitamura e, kurokawa k, nomura s. influence of maxillary cortical bone thickness, implant design and implant diameter on stress around implants: a three-dimensional finite element analysis. j prosthodont res 2010; 54(3): 133-42. 40. tsolakis ai, khaldi l, makou m, lyritis gp, spyropoulos mn, dontas ia. cortical bone response adjacent to applied light orthodontic forces in ovariectomized rats. j musculoskelet neuronal interact 2008; 8(4): 375-8. azhar f.docx j bagh college dentistry vol. 28(2), june 2016 the measurements of pedodontics, orthodontics and preventive dentistry 103 the measurements of maxillary alveolar bone density at 1315 years age by using spiral computerized tomography azhar a.farage, b.d.s. (1) fakhri a. al fatlawi, b.d.s., m.sc. (2) abstract background: bone density is a major factor that affect mini implant primarily stability; no iraqi studies have evaluated bone density related to mini-implant placement for orthodontic anchorage at age 13 -15 years. the present research aims to evaluate gender, side and site differences in the bone density at various orthodontic implant sites for the maxillary alveolar bone. materials and methods: twenty nine individuals (16 males and 13 females) had subjected to clinical examination, then 64-multislice computed tomography scan data were evaluated and bone density was measured in hounsfield unit at 21 points (9 points for each side and 3 points between the right and left central incisors) . results: the results obtained showed that there are no significant differences in bone density between males and females and between the left and right sides were found. there was no significant differences in bone density between the maxillary buccal cortical bone and the palatal cortical bone were generally except that at lateral incisor and canine point where the palatal side had higher bone density than buccal side. the mean bone density of the cancellous bone in the anterior part was higher than that in the posterior of the maxilla. conclusions: when orthodontic, mini implant are indicated, no gender and side difference affect the success rate regarding bone density. keyword: bone density, mini-implant, computerized tomography. (j bagh coll dentistry 2016; 28(2):103-107). intruduction the orthodontist always constructs an appliance to produce certain desired tooth movements. for every action, there is an equal and opposite reaction. inevitably, reaction forces can move other teeth if the appliance contacts them. anchorage, then, is resistance to reaction forces that is provided by other teeth. anchorage control is an important factor directly affecting the results of orthodontic treatment, mainly when maximum anchorage is necessary (1). although traditional systems to provide tooth movement with enhanced anchorage have been developed, limitations due to the need for patient cooperation, operator skill, and precision in determining the ideal force to perform the movement make the control of posterior anchorage a challenge (2). to overcome problems associated with anchorage loss, skeletal anchorage methods such as dental miniplates and miniscrews. miniimplants are a valuable alternative to extraoral anchorage, which need cooperative patient (3). microscrew implants have many benefits, including easy placement and removal, immediate loading, minimal anatomical limitations thanks to their small size, and low cost, as compared with other skeletal options. many reports have dealt with various clinical situations, such as en-masse retraction of the anterior or posterior teeth, retrac (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. tion of the whole dentition, molar distalization, molar up righting, protraction of molars, and forced eruption of the canines (4,5). several sites have been proposed for the placement of miniscrews or microscrew implants. most frequently recommended sites were the midpalatine area; inter-radicular spaces are generally the site of choice for mini implant placement for their ease of access, simplicity of procedure, and less traumatic placement (6). the alveolar bone between the maxillary second premolars and first molars, and the mandibular first and second molars (7).three main factors affect the success of dental implants: host, implant, and surgical method. density of bone is a host factor that is known to play a crucial role in mini implant stability. a close relationship was shown between bone density and the success of dental implants. during early stages, bone density appears to be the key determinant for stationary anchorage of miniimplants in the sites with inadequate cortical bone thickness because primary retention of mini-implants achieved by mechanical means rather than through osseointegration (8). characteristic of all bones are a dense outer sheet of compact bone and a central cancellous bone. the cancellous bone forms a trabecular network, surrounds marrow spaces that may contain either fatty or hematopoietic tissue, lies subjacent to the cortical bone, and makes up the main portion of a bone. the maxilla has a thin compact bone and fine trabecular bone supporting the teeth (9). mini implant stability is primarily related to local bone density. tads are also j bagh college dentistry vol. 28(2), june 2016 the measurements of pedodontics, orthodontics and preventive dentistry 104 known to be frequently associated with higher failure rates among adolescents when compared with adults, which suggests that age may be a contributing factor. it has been speculated that it may be due to thinner cortical layers coupled with immature bone qualities in adolescents (10). the demonstration of bone density by means of ct scanning directly depends on the quantity of inorganic crystals contained in the bone tissue keeping in mind that bone is not uniform in structure but composed of several layers of different materials. one method for measuring bone density appropriately is ct. ct has expediency and nondestructive nature and its images in dicom format contain data of bone density so that the software program can measure it. misch (11) mentioned that the bone density measurements using ct provide more accurate results than radiographic assessment. materials and methods the sample the sample of this study consisted of ct images for patient who were attending al. shaheed ghazi al-hariri hospital/the computerized tomography department. only 29 subjects (16 male and 13 female, age range 13-15 years).subject selection criteria included: 1) all subjects are iraqi in origin. 2) the age ranged between 13-15 years. 3) they have full set of permanent teeth in both jaws “excluding the 3rd molar”. 4) they have bilateral class i molar and canine relationships, with normal over jet ranging between 2-4 mm and normal overbite ranging between 1-2 mm. 5) clinically skeletal class i was determined by two-finger method. 6) subjects should have no large metal restorations that cause streak artifacts and affect the density of the adjacent bone tissue. 7) no history of dentofacial deformities and pathologic lesions in the jaws. 8) no history of chronic regular use of medication affects the bone density such as steroids, barbiturates, anticonvulsants, and thyroid hormone replacements. 9) none of the subjects had received previous orthodontic and orthopedic treatment. materials and equipment 1. disposable dental mirrors and probes and sliding caliper 2.64-multi-detecter ct scanner (somatom definition as, siemens ag, germany, zuhr(ultra highresolution). 3. seimens work station computer. 4. syngo vx2009b, image fusion (siemens ag imaging software multimodality reading, germany). method the mean bone density was measured using software (syngo 2009b) that had already been incorporated into the ct machine. the points were selected using 3d, axial, coronal and sagittal planes. with the "three dimensional " mode, the intended points could be seen in three planes of space at the same time to determine the specific location since all the slices in the 3 planes will be changed at the same time and each slice can be matched by the slice serial number to be opened on the"viewing"mode for the maxillary alveolar bone 21 points was measured, 9 points for each side between each two teeth (lateral inciser and canine,second premolar and first molar and between first molar and second molar), and 3 points between the right and left central incisors. for buccal and palatal cortical bone distal to the distal most surface of the tooth of interest was chosen apically 5 to 7 mm from the alveolar crest, the density of the cancellous bone was measured at the trabeculae, located halfway buccopalataly between the buccal and palatal cortical plates of each tooth. results bone density assessed and the results were expressed by descriptive statistics including the mean and standard deviation of the mean. according to t-test, there was no significant difference in the maxillary alveolar bone density between the right and left sides in different areas in male (table1) and female group (table 2).then matching measurements of the right and left sides combined for further analysis. j bagh college dentistry vol. 28(2), june 2016 the measurements of pedodontics, orthodontics and preventive dentistry 105 table 1: comparison of the bone density between the right and left sides in different areas in male group (n=16) areas sides right left comparison mean s.d. mean s.d. t-test p-value 7-6 buccal 989.27 131.18 1046.40 182.48 -2.085 0.056 cancellous 482.60 63.96 494.60 97.27 -0.473 0.644 palatal 1018.73 136.75 1022.67 129.28 -0.114 0.911 6-5 buccal 1026.00 106.96 1006.40 169.92 0.583 0.569 cancellous 532.33 91.09 484.60 145.44 1.342 0.201 palatal 1007.07 137.34 1030.07 166.46 -0.773 0.452 3-2 buccal 983.13 152.63 1002.07 180.36 -0.572 0.576 cancellous 616.07 140.50 556.80 188.52 1.271 0.225 palatal 1030.53 120.29 1055.67 159.58 -0.735 0.474 table 2: comparison of the bone density between the right and left sides in different areas in female group (n=13) areas sides right left comparison mean s.d. mean s.d. t-test p-value 7-6 buccal 1019.27 91.44 1003.13 126.18 0.505 0.621 cancellous 478.87 49.37 470.40 52.98 0.428 0.675 palatal 1014.87 63.57 1044.60 121.60 -1.315 0.210 6-5 buccal 1008.87 105.21 1047.93 106.30 -1.875 0.082 cancellous 500.60 108.77 487.80 79.46 0.736 0.474 palatal 1029.13 89.31 1063.73 133.23 -0.874 0.397 3-2 buccal 1016.53 105.20 1005.80 131.50 0.370 0.717 cancellous 524.00 144.19 521.13 106.55 0.073 0.943 palatal 1063.93 83.26 1030.27 139.79 1.031 0.320 descriptive statistics of the bone density for the male, the alveolar the buccal cortical bone density ranged approximately from (992±164 hu) at lateral incisor\canine point to (1021±119 hu) at the central incisor\ central incisor point. for, alveolar palatal cortical bone density ranged approximately from (997± 145hu) at central incisor\ central incisor point to (1043±139 hu) at lateral incisor \ canine point. thedensity of the alveolar cancellous bone of the maxilla ranged approximately from (488±81 hu) at the first molar / second molar point to (638±136 hu) at the central incisor/central incisors point (table 1). descriptive statistics of the bone density for the female, the alveolar buccal cortical bone density ranged approximately from (1002±140hu) at central incisor\ central incisor point to (1028±105 hu) at the second premolar/ first molar point. for, alveolar palatal cortical bone density ranged approximately from (1025±117hu) at central incisor\ central incisor point to (1047±114 hu) at lateral incisor \ canine point the density of the alveolar cancellous bone of the maxilla ranged approximately from (474±50 hu) at the first molar / second molar point to (570±140 hu) at the central incisor/central incisors point.(table 2). according to t-test, there was no significant difference in the maxillary alveolar cortical and cancellous bone density between males and females in most points (table 3). descriptive statistics of the bone density for total sample after combined male and female, the alveolar buccal cortical bone density ranged approximately from (1001±141hu) at lateral incisor\canine point to (1022±123 hu) at the second premolar/ first molar point. for, alveolar palatal cortical bone density ranged approximately from (1011±117hu) at central incisor\ central incisor point to (1045±126 hu) at lateral incisor \ canine point. the density of the alveolar cancellous bone of the maxilla ranged approximately from (481±67 hu) at the first molar / second molar point to (604±141 hu) at the central incisor/central incisors point (table 5). j bagh college dentistry vol. 28(2), june 2016 the measurements of pedodontics, orthodontics and preventive dentistry 106 table 3: descriptive statistics and genders difference of the bone density in different areas (n=29) area side descriptive statistics genders difference males females mean s.d. mean s.d. t-test p-value 7-6 buccal 1017.83 158.83 1011.20 108.58 0.189 0.851 cancellous 488.60 81.11 474.63 50.50 0.801 0.427 palatal 1020.70 130.77 1029.73 96.53 -0.304 0.762 6-5 buccal 1016.20 139.86 1028.40 105.80 -0.381 0.705 cancellous 508.47 121.68 494.20 93.82 0.509 0.613 palatal 1018.57 150.40 1046.43 112.82 -0.812 0.420 3-2 buccal 992.60 164.45 1011.17 117.13 -0.504 0.616 cancellous 586.43 166.12 522.57 124.58 1.685 0.097 palatal 1043.10 139.43 1047.10 114.34 -0.122 0.904 1-1 buccal 1021.93 119.29 1002.73 140.64 0.403 0.690 cancellous 638.13 136.99 570.87 142.69 1.317 0.198 palatal 997.13 145.65 1025.00 83.30 -0.643 0.525 table 4: comparison of the bone density between the right and left sides in different areas for total sample (n=29) areas sides right left comparison mean s.d. mean s.d. t-test p-value 7-6 buccal 1004.27 112.14 1024.77 155.71 -0.942 0.354 cancellous 480.73 56.17 482.50 77.93 -0.111 0.921 palatal 1016.80 104.80 1033.63 123.82 -0.823 0.417 6-5 buccal 1017.43 104.61 1027.17 140.85 -0.482 0.633 cancellous 516.47 99.89 486.20 115.16 1.534 0.136 palatal 1018.10 114.38 1046.90 149.13 -1.183 0.247 3-2 buccal 999.83 129.91 1003.93 155.10 -0.188 0.852 cancellous 570.03 147.51 538.97 151.55 1.020 0.316 palatal 1047.23 103.05 1042.97 147.97 0.179 0.859 table 5: descriptive statistics of the bone density in different areas for total sample(n=29) area side mean s.d. 6-7 buccal 1014.52 134.93 cancellous 481.62 67.05 palatal 1025.22 114.05 5-6 buccal 1022.30 123.10 cancellous 501.33 107.52 palatal 1032.50 132.56 2-3 buccal 1001.88 141.86 cancellous 554.50 149.53 palatal 1045.10 126.44 1-1 buccal 1021.93 128.50 cancellous 604.50 141.63 palatal 1011.07 117.43 discussion in the present study, the inter-radicular spaces were the areas of interest since they are generally the site of choice for mini implant placement for their ease of access, simplicity of procedure, and less traumatic placement (6,12). the results of the present study indicate that there were no significant differences between both sides for all measured variables for both genders. human studies showed no difference in bone densities between left and right sides (3,8,13,14-17). this investigation found no significant gender differences in buccal and palatal cortical bone density which is in accordance with others (3,8,13,16 17). this non-significant gender difference can be reflected clinically by previous studies that found no differences in the success rate and stability of mini implants between male and female subjects (18,19). the lack of gender differences in this study can be explained by the presence of estrogen j bagh college dentistry vol. 28(2), june 2016 the measurements of pedodontics, orthodontics and preventive dentistry 107 hormone in higher levels in the female subjects compared to the male subjects, which is compensated by the exercises exerted by the males and the different chewing patterns. on the other hand, other studies reported significant differences in mean bone densities between males and females human subjects (age range 12-50) (20), which are inconsistent with the present study. this inconsistency may be related to subject age differences between two studies, as age range in the present study was 13-15 years. however other studies (10,14,20) showed that adult females had significantly greater palatal cortical bone density than adult males did, this is in conflict with the finding of the present study suggesting that the presence of gender difference may be depend on the different specific sites being examined in the palate or due to ethnic variation or the ct scanning machine setting being used. clinicians should remember that the reported data are only guides, each patient is unique, and the density variability among patients is high. in high-risk cases, such as patients with systemic or severe craniofacial problems, each site should be evaluated before mini-implant placement. it remains to be aware of the risk of computed tomography, which continues to impart a higher radiation dosage compared to conventional radiographs, but to weigh this against the power of the diagnostic information that it can provide. references 1. proffit wr, fields hw, sarver dm, ackerman jl. contemporary orthodontics. 5th ed. st. louis: mosby elsevier; 2013. 2. park hs, kwon tg. sliding mechanics with microscrew implant anchorage. angle orthod 2004; 74(5): 703-10. 3. park hs, lee yj, jeong sh, kwon tg. density of the alveolar and basal bones of the maxilla and the mandible. am j orthod dentofacial orthop 2008; 133(1): 30-7. 4. park hs.the use of micro-implant as orthodontic anchorage. seoul, korea: nare; 2001. 5. park hs, bae sm,kyung hm, sung jh.micro-implant anchorage for treatment of skeletal classi bialveolar protrusion. j clin orthod 2001; 35: 417-22. 6. chaimanee p, suzuki b, suzuki ey. ‘‘safe zones’’ for miniscrew implant placement in different dent skeletal patterns. angle orthod 2011; 81(3): 397-403. 7. nanda r, uribe fa. temporary anchorage devices in orthodontics.st. louis: mosby elsevier; 2009. 8. chun ys, lim wh. bone density at interradicular sites: implications for orthodontic mini-implant placement. orthodcraniofac res 2009; 12 (1): 25-32. 9. nanci a. ten cate’s oral histology; development, structure, and function. 7thed. mosby elsevier, 2008. 10. han s, bayome m, lee j, lee yj, song hh, kook ya. evaluation of palatal bone density in adults and adolescents for application of skeletal anchorage devices. angle orthod 2012; 82(4): 625-31. 11. misch ce. density of bone: effect on surgical approach, and healing. contemporary implant dentistry. st. louis: mosby 1993; 469-87. 12. yamada k, kuroda s, deguchi t, yamamoto tt, yamashiro t. distal movement of maxillary molars using miniscrew anchorage in the buccal interradicular region. angle orthod 2009; 79(1): 78-84. 13. choi jh, park ch, yi sw, lim hj, hwang hs. bone density measurement in interdental areas with simulated placement of orthodontic miniscrew implants. am j orthod dentofacial orthop 2009; 136 (6): 766.e1-12. 14. borges ms, mocha jn .bone density assessment for mini-implants position. dental press j orthod 2010; 15(6): 58.e1-9. 15. tewfiq s m. bone density determination for the maxilla and the mandible in different age groups by using computerized tomography. a master thesis, college of dentistry. university of baghdad, iraq. 2012. 16. ozdemir f, tozlu m, germec-cakan d.quantitative evaluation of alveolar cortical bone density in adults with different vertical facial types using cone-beam computed tomography. korean j orthod 2014; 44(1): 36-43. 17. chugh t, ganeshkar sv, ameet v, abhay k. quantitative assessment of interradicular bone density in the maxilla and mandible: implications in clinical orthodontics. progorthod2013; 14: 38. 18. cheng sj, tseng iy, lee jj, kok sh. a prospective study of the risk factors associated with failure of mini-implants used for orthodontic anchorage. int j oral maxillofac implants 2004; 19(1): 100-6. 19. lim hj, eun cs, cho jh, lee kh, hwang hs. factors associated with initial stability of miniscrews for orthodontic treatment. am j orthod dentofacial orthop 2009; 136(2): 236-42. 20. cassetta m, stefanelli lv, pacifici a, pacifici l, barbato e. how accurate is cbct in measuring bone density? a comparative cbct-ct in vitro study. clin implant dent relate res 2014; 16: 471-8. 21. moon ch, park hk, nam js, im js, baek sh. relationship between vertical skeletal pattern and success rate of orthodontic mini-implants. am j orthod dentofacial orthop 2010; 138(1): 51-7. j bagh college dentistry vol. 28(4), december 2016 surgical biopsy in oral and maxillofacial surgery and periodontics 111 surgical biopsy in cervical lymphadenopathy salwanyousif hanna bede, b.d.s., f.i.b.m.s. (a) auday m. al-anee, b.d.s., f.i.b.m.s. (b) hassanien a. aljumaily, b.d.s., c.a.b.m.s. (b) abstract background: cervical lymph nodes are the most frequently enlarged and biopsied of all the peripheral lymph nodes and in most of the cases the enlargement results from benign infectious causes, however, the presence of cervical lymphadenopathy (lap) requires accurate diagnosis to exclude more serious causes. the aim of this study was to analyze cases of iraqi patients presenting with cervical lap who underwent surgical lymph node biopsy to establish accurate diagnosis. materials and methods: this retrospective study included 25 patients who presented with cervical lap for whom surgical biopsy was performed to establish a definitive diagnosis. the investigated data included the demographic and clinical parameters in addition to the final histopathological diagnosis. results: twenty five patients were included in this study with a mean age of 33.8 years and female predominance; benign diseases were diagnosed in 56% of the cases whereas the remaining 44% were diagnosed with malignant diseases. tuberculous lymphadenitis was the most common cause. conclusion: this study emphasizes the importance of surgical lymph node biopsy in establishing a definitive diagnosis in patients presenting with cervical lap. keywords: surgical biopsy, cervical lap, definitive diagnosis. (j bagh coll dentistry 2016; 28(4):111-114) introduction lymphadenopathy (lap), a medical description of swollen lymph nodes (1), is a symptom that manifests in patients of all ages (2) and may be caused by a wide variety of infectious, hematological, neoplastic and connective tissue disorders (3). lap can be localized or generalized and it is also classified as acute, subacute and chronic, the latter constitutes any lap that does not resolve by 6 weeks (4). of all the peripheral lymph nodes, the cervical ones are the most frequently enlarged and biopsied and in most of the cases the enlargement results from benign infectious causes, however, the presence of cervical lap requires accurate diagnosis to exclude more serious causes. the optimal workup for cervical lap includes thorough history taking, physical examination, blood tests and imaging (5). ultrasonography (us), computed tomography (ct) and magnetic resonance imaging (mri) are helpful in evaluating the size, site, contents and the vascular pattern of the lymph nodes (6,7) but the definitive diagnosis usually requires fine needle aspiration cytology (fnac) and/or lymph node excisional biopsy which is considered a vital part of the management (8). the aim of this study was to analyze cases of iraqi patients presenting with cervical lap who underwent surgical lymph node biopsy to establish accurate diagnosis. (a)assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (b)lecturer, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. materials and methods this retrospective study included patients who presented with cervical lap of more than 1 month duration and underwent surgical lymph node biopsy at the oral and maxillofacial surgery units of al-yarmouk teaching hospital and ghazy al-hariri hospital for surgical specialties during the period extending from january 2009 to january 2015. a thorough personal and family history was taken from all the patients followed by intraoral and extra-oral clinical examination to exclude any source of infection. the examination of the neck included the site, size, laterality, tenderness and the texture of the lymph nodes. in addition to the clinical examination and blood investigations, us and/or ct were taken for all the patients to provide information about the size and the extent of the enlarged lymph node, in some cases fnac was performed. patients presenting with an acute upper respiratory tract infections, febrile illness, and history of head and neck malignancy or lymphoma were excluded from this study. all the surgical procedures were performed under general anesthesia after obtaining informed consents from the patients; the most accessible enlarged lymph node was excised through extra-oral approach and sent for histopathological examination. the investigated data included the demographic and clinical parameters in addition to the final histopathological diagnosis. descriptive statistics included percentages and means of patients’ age and gender, durations of onset of lap and final diagnoses. inferential statistical analysis included student t-test for 2 j bagh college dentistry vol. 28(4), december 2016 surgical biopsy in oral and maxillofacial surgery and periodontics 112 independent means, analysis of variance (anova) and tukey hsd tests for the mean age of patients with different reported etiologies in addition to chi square test, the difference was considered significant at p ≤ 0.05. results twenty five patients presented with cervical lap, they included 16 females (64%) and 9 males (36%) with a male: female ratio of 1:1.8, the age range at presentation was from 8 to 83 years with a mean of 33.8 years. a mean duration of 6 months of lymph nodes enlargement was reported by the patients. on clinical examination lap was bilateral in 7 patients (28%) and unilateral in 16 patients (64%), whereas in 2 (8%) patients it was in the midline. surgical biopsy involved the most accessible lymph nodes; these were submandibular(fig 1) in 13 patients, upper jugular in 9 patients, submental in 2 patients and posterior triangle in 1 patient. figure 1: (a) preoperative view showing enlarged right submandibular lymph node. (b) intra-operative view showing excision of the enlarged lymph node through submandibular incision. fourteen patients (56%) with a mean age of 23.3 years were diagnosed with benign diseases while the remaining 11 patients (44%) with a mean age of 44.8 years had malignant diseases; the main characteristics of the 2 groups are shown in table 1. table 1: summary of the characteristics of lap in patients diagnosed with benign and malignant diseases benign malignant p value mean age 23.3 years 44.8 years 0.0025* gender male female 2 patients 12 patients 7 patients 4 patients 0.0107* laterality unilateral bilateral 10 patients 2 patients 6 patients 5 patients 0.1339 * = significant the histopathological results revealed 4 etiologies for cervical lap (table 2), the differences in the mean ages of patients among different etiologies were statistically significant, but to note that patients who presented with lap due to secondary metastasis were significantly older than patients who were diagnosed with other lap etiologies who showed non-significant differences. table 2: summary of the etiologies of cervical lap diagnosis patients (%) mean age/year one way anova tuberculous lymphadenitis 8 (32) 23.4 df= 3 f= 7.86 p= 0.001* secondary metastasis 7 (28) 54 non-specific inflammatory reaction 6 (24) 23.3 hodgkin’s lymphoma 4 (16) 28.5 * = significant females showed higher incidence in cases of tuberculous lymphadenitis and non-specific inflammatory reaction with a male to female ratios of 1:7 and1:5respectively, whereas in cases of secondary metastasis of unknown primary malignancy males showed higher incidence with a ratio of 2.5:1. lymphoma, on the other hand, showed equal gender distribution in 11 patients the surgical biopsies were preceded by fnac, in 6 patients the results of fnac matched with the final diagnosis yet in the remaining 5 patients the results were inconclusive. postoperatively, recovery was uneventful for all j bagh college dentistry vol. 28(4), december 2016 surgical biopsy in oral and maxillofacial surgery and periodontics 113 the patients and no major complications were recorded. after confirming the diagnosis, patients were referred for further medical evaluation and management according to the involved disciplines. discussion it is estimated that the human body contains about 800 lymph nodes, 300 of them are situated in the neck (9) and cervical lap, defined as lymph node measuring more than 1 cm in diameter (10), is one of the commonly encountered conditions in the outpatient setting (5). in many cases the cause of cervical lap can be disclosed through noninvasive diagnostic measures yet in other cases definitive diagnosis may require surgical biopsy of the lymph nodes (2). although it is believed that in general population only 3.2% of cervical lap cases require surgical biopsy (11), delayed diagnosis of lap in certain serious conditions like tuberculosis, lymphoma or secondary malignant metastasis may affect the prognosis of the disease adversely (5), and it is in this context that surgical lymph node biopsy is considered the gold standard for establishing a definite diagnosis (8). this study showed female preponderance in cervical lap patients which is in line with other iraqi studies (12, 13), other studies, on the other hand, reported higher incidence of cervical lap in males (14). benign diseases are also higher in incidence than malignant diseases, al-alwan et al. in their study in 1996 reported incidences of benign and malignant lap which are nearly similar to the current study (15). the results of this study reveal that tuberculous lymphadenitis is the most common cause of cervical lap, the same finding is also reported by abdulnabi (12) and by hamad and hamza (13), of note that both studies are from southern provinces in iraq, although the latter study reported a much higher incidence (70%). tuberculous lymphadenitis is also reported to be a common cause of cervical lap in other asian countries where 58% is reported in india (14) and 22.4% is reported in korea (16), weiler et al., in their review of 538 tuberculosis patients, reported only 3.9% of cervical tuberculous lymphadenitis (17). in developing countries tuberculous lymphadenitis is one of the most common causes of cervical lap with female preponderance whereas it is considered a disease of the foreign-born in developed countries (18). the pathogenic mechanism of tuberculous lymphadenitis, in most cases, is through reactivation of dormant lymphatic system disease, initially caused by primary pulmonary tuberculosis, resolving later with minimal pulmonary scarring and a positive tuberculin test. a second mechanism is based on lymphatic spread after the organism gains direct entry through the mucous membrane lining of the oral cavity (17). surgical lymph node biopsy is superior to fnac in establishing an accurate diagnosis of tuberculous lymphadenitis, a finding that is reported in many studies (14, 18). the malignant diseases diagnosed in this study included lymphoma and secondary metastasis of unknown primary tumors with a higher incidence than that reported in other studies (8, 12, 13) and with significantly higher mean age of patients than that in benign diseases. secondary lymph node metastasis of unknown primary tumor was detected in 28% of the cases in this study. it is believed that about 10 % of patients with secondary metastasis to the cervical lymph nodes have no identifiable primary tumor, this necessitates a thorough clinical examination and imaging using contrast enhanced computed tomography (ct) scan and positron emission tomography (pet) scan and endoscopic search for primary tumors with special attention to sites of the head and the neck where a primary lesion may remain occult, for example, the tonsil, the base of tongue, nasopharynx and pyriform sinuses (19). patients with metastatic diseases had significantly higher mean age than all other patients with male predominance which is in line with other studies (12, 20). fnac is described as a reliable diagnostic method provided that conducted by experienced histopathologists and some authors recommend repeating the procedure in cases of uncertain or non-diagnosis histology (20). surgical biopsy in such cases is controversial, due to the reported adverse effects on neck disease control and high incidence of local recurrence yet some studies found no such effects provided that the biopsy was followed by definitive treatment (21). the incidence of lymphoma in this study is lower than that reported in other studies (7, 12, 15) yet higher than that reported elsewhere (5). abdulnabi (12) found a higher incidence of lymphoma after surgical biopsy of cervical lymph nodes in comparison to fnac which may highlight the superiority of surgical biopsy in establishing an accurate diagnosis. matsumoto et al. suggested predictive criteria to perform surgical biopsy when definitive diagnosis of lymphoma cannot be made by fnac, these criteria are advanced age, large lymph node size and high level of soluble interlukine-2 receptor (sil-2r) (2). on the other hand tsuji et al. (7) suggested that us and ct scan evaluation and high level of thymidine kinase might be useful in j bagh college dentistry vol. 28(4), december 2016 surgical biopsy in oral and maxillofacial surgery and periodontics 114 determining the need for surgical biopsy in cases of lymphoma. non-specific inflammatory reaction is the third cause of cervical lap (25%), this is in contrast to other iraqi studies (12, 15) and reports from asian and african countries that found that this cause was the most common diagnosis in lap (8, 22, 23). mohan et al. in 2007 (8) found that in 3% of patients a second pathology could be identified within 6 months of the initial biopsy and they maintain that this group of patients may require further investigations and should be followed up to detect whether they develop additional conditions. fnac is reported as an efficient diagnostic tool with high accuracy rate in cervical lap (2, 12), but in this study about 45% of the cases (5 of 11 patients) that underwent fnac before surgical biopsy had inconclusive or non-diagnosis results. in the institutions where this study was conducted surgical biopsy is preferred as a more accurate diagnostic tool than fnac especially when serious diseases are suspected since their treatment may be associated with high morbidity or even mortality, thus minimizing the risk of misdiagnosis and subsequent over-treatment. this study is limited in its small number of patients and its retrospective methodology, but, nevertheless, it emphasizes the importance of surgical lymph node biopsy in establishing a definitive diagnosis in patients presenting with cervical lap. the results show that cervical lap is caused by benign diseases more than malignant diseases; they also reveal the high incidence of tb lymphadenitis and malignant diseases in iraq. references 1. marcovitch h. black’s medical dictionary 41st edition. a&c black. london 2005. p 424. 2. matsumoto f, itoh s, ohba s-i, yokoi h, furukawa m, ikeda k. biopsy of cervical lymph node. auris nasus larynx 2009; 36: 71-4. 3. obafunwa jo, olomu ln, onyia nj. primary peripheral lymphadenopathy in jos, nigeria. west afr j med 1992; 2: 25-8. 4. allhiser jn, mcknight ta, shank jc. lymphadenopathy in a family practice. j fam pract 1981; 12(1): 27-32. 5. jeong w-j, park m-w, park sj, ahn s-h. initial work-up for cervical lymphadenopathy: back to basics. eur arch otorhinolaryngol 2012; 269: 2255-63. 6. ying m, ahuja a, brook f. accuracy of sonographic vascular features in differentiating different causes of cervical lymphadenopathy. ultrasound in med biol 2004; 30(4): 441-7. 7. tsuji t, satoh k, nakano h, nishide y, uemura y, tanaka s, kogo m. predictors of the necessity for lymph node biopsy of cervical lymphadenopathy. j craniomaxillofac surg 2015; 43: 2200-4. 8. mohan a, kumaraswamy r, phaneendra bv, chandra a. aetiology of lymphadenopathy in adults: analysis of 1724 cases seen at a tertiary care teaching hospital in southern india. natl med j india 2007; 20: 78-80. 9. castelijns ja, van den berkel mwm. imaging of lymphadenopathy in the neck. eur radiol 2002; 12: 727-38. 10. sambandan t, christeffi mabel r. cervical lymphadenopathy a review. jaids 2011; 2: 31-3. 11. leung akc, robson lm. childhood cervical lymphadenopathy. j pediatr health care 2004; 18: 3– 7. 12. abdulnabi hm. the predictive value of fine needle aspiration cytology in the assessment of cervical lymphadenopathy. iraqi postgraduate medical journal 2007; 6(3): 190-3. 13. hamad mmj, hamza al. tuberculous cervical lymphadenopathy in babylon. medical j babylon 2014; 11(1): 169-72. 14. mili mk, phookan j. a clinicopathological study of cervical lymphadenopathy. int j dent med res 2015; 1(5): 24-7. 15. al-alwan na, al-hashimi as, salman mm, al-attar ea. fine needle aspiration cytology versus histopathology in diagnosing lymph node lesions. east mediterr health j 1996; 2(2): 320-5. 16. song jy, cheong hj, kee sy, lee j, sohn jw, kim mj, seo sil, kim is, kim wj. disease spectrum of cervical lymphadenitis: analysis based on ultrasoundguided core-needle gun biopsy. j infect 2007; 55: 31016. 17. weiler z, nelly p, baruchin am, oren s. diagnosis and treatment of cervical tuberculous lymphadenitis. j oral maxillofac surg 2000; 58: 477-81. 18. memish za, mah mw, al mahmood s, bannatyne rm, khan my. clinico-diagnostic experience with tuberculous lymphadenitis in saudi arabia. clin microbiol infect 2000; 6: 137-41. 19. shah jp, patel sg, singh b. jatin shah’s head and neck surgery and oncology, 4th ed. st. louis: elsevier mosby 2012; pp. 426-70. 20. zhuang sm, wu x-f, li j-j, zhang g-h. management of lymph node metastases from an unknown primary site to the head and neck (review). mol clin oncol 2014; 2: 917-22. 21. colletier pj, garden as, morrison wh, goepfert h, geara f, ang kk. postoperative radiation for squamous cell carcinoma metastatic to cervical lymph nodes from an unknown primary site: outcomes and patterns of failure. head neck 1998; 20: 674-81. 22. sibanda en, stanczuk g. lymph node pathology in zimbabwe: a review of 2194 specimens. q j med 1993; 86: 811-17. 23. moore sw, schneider jw, schaaf hs. diagnostic aspects of cervical lymphadenopathy in children in the developing world: a study of 1,877 surgical specimens. pediatr surg int 2003; 19: 240-4. j bagh college dentistry vol. 29(1), march 2017 effect of different pedodontics, orthodontics and preventive dentistry 160 effect of different fluoride agents on the load deflection characteristics of heat activated nickel titanium arch wires (an in vitro study) rawaa saadoonhashim, b.d.s. (1) sami k. al-joubori,b.d.s., m.sc.(2) abstract background:hydrogen absorption and related degradation in the mechanical properties of ni-ti based orthodontic wires has been demonstrated following exposure to fluoride prophylactic agents. this study was designed to investigate the effects of three fluoride containing agents on the load deflection characteristics of heat activated nickel titanium arch wires during unloading phase. material and method: eighty specimens of heat activated nickel titanium arch wires were obtained from ortho technology company, half of which had a 0.016 inch round and 0.019x0.025 rectangular. ten specimens from both wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or phos-flur mouth rinse) or in the controlled medium “normal saline”, and incubated at 37˚c for sixty minutes. a wp 300 universal material testing machine was modified and used to perform a three point bending test in a water path at 37˚c ±1˚c.the statistical difference between the different agents were analyzed using anova and lsd tests. results: the unloading forces at 0.5, 1.0, and 1.5 mm where significantly reduced especially in neutral sodium fluoride treated specimens. conclusion: based on the results founded in th study it might be preferred to use prophylactic agent with the least fluoride ions concentration.it can be concluded that the tested agents have only a limited effect on the load deflection behavior of the heat activated ni-ti wires, in a way that they do not have a clinically significant effect on the mechanical behavior of these wires. key words: fluorides, load-deflection, heat activated ni-ti wires.(j bagh coll dentistry 2017; 29(1):160-164) introduction orthodontic wires made from titanium alloys provide light continuous force with large amount of activation for long periods. this makes them extremely useful as initial or intermediate wires between the first alignment and finishing stages of treatment(1). heat-activated nickel titanium wires have been gaining popularity in the orthodontic practice during the last decade. these so called third generation wires have been marketed with clinically useful shape memory property which is the capability of ni-ti wires to be plastically deformed in their martensitic phase, in addition to the low stiffness, high spring back and super elasticity (1,2). fluoride prophylactic agent, such as acidulated phosphate fluoride (apf), have been used extensively to prevent demineralization or do remineralization of white spot lesionsaround orthodontic brackets and bands; however, the fluoride ions in the prophylactic agents have been reported to cause corrosion and discoloration of titanium and its alloys (3). degradation in the mechanical properties lead to a reduction in appropriate orthodontic force, thereby causing delayed straightening of irregular teeth(4). (1) master student, department of orthodontics, college ofdentistry, university of baghdad. (2) assistant professor, department of orthodontics, college of dentistry,university of baghdad. this is an in vitro study is to evaluate the effect of three different fluoride agentson the load deflection of heatactivated nickel titanium arch wires. materials and methods the samples comprised eighty pieces of 4cm length obtained by cutting the straight, posterior portion of preformed upper heat-activated nickel titanium arch wire using a cutter.forty pieces were 0.016" and forty pieces were0.019x0.025" (ortho technology co., ca, u.s.a.). these samples were divided into four groups, each group contains 20 pieces (10 pieces of 0.016" and 10 pieces 0.019x0.025") according to immersion medium: 1)control medium (normal saline 0.9% w/v ph=7). 2)0.4% stannous fluoride gel (dental technologies alpha-dent, lincolnwood, illinois, u.s.a with ph=3.3) 3) 0.044%w/v phos-flur mouth rinsed (colgate oral pharmaceutical, new york, u.s.a withph=4.2) 4) 1.1% neutral sodium fluoride gel (dentmat holdings, lompoc, california, u.s.a with ph=7). all samples were incubated at 37˚c in inert plastic tubes of 10ml capacity for sixty minutes (60 minutes=1 minutes per day topical fluoride j bagh college dentistry vol. 29(1), march 2017 effect of different pedodontics, orthodontics and preventive dentistry 161 application for two months). then the samples were removed from their respective test media washed with normal saline and placed in a new, clean, and individually labeled plastic tubes before mechanical testing. the three point bending test was carried out to test the load deflection characteristics of the selected arch wires. the samples were mounted into a three point bending test fixture (stainless steel jig with two barreled rods set 15 mm apart) the mid portion of the wire were loaded to 2mm deflection by rotating the hand wheel of the wp300 universal testing machine (g.u.n.t. gerätebau gmbh, hamburg, germany) in clock wise direction then very gently unwind the hand wheel in counter clock direction to unload to zero deflection. for statistical analysis the unloaded forces at 1.5, 1, 0.5 mm were used since unloading phase of the wire represent the necessary forces to achieve tooth movement. to simulate aqueous oral environment the test was carried out in a water bath at 37˚c ±1˚c the temperature was controlled by using a digital thermometer. one way analysis of variance (anova) was used to examine whether any significant difference at p<0.05exist between the four tested groups. further, lsd was used to compare among tested groups. results table 1 showedthe means and standard deviations of forces at intervals of 0.5 mm deflection during unloading for 0.016" and 0.019x0.025" heat activated nickel titanium arch wire. f-test by anova table showed that there was statistically a highly significant difference in the load defection of 0.016" and 0.019x0,025 " heat activated nickel titanium arch wires immersed in different fluoride agents during unloading at 1.5, 1.0, 0.5 mm p <0.001. table 2 showed the results of lsd after anova for 0.016" and 0.019x0.025" heat activated arch wire. the load deflection graphs for heat-activated nickel titanium arch wires after being immersed in tested agents in comparison with the control group are presented in figure (1). table 1: descriptive statistics of load in (gm.) during unloading phase and groups' difference for hant arch wires. arch wires dimension deflection (mm.) descriptive statistics media difference nacl snf2 apf nf mean sd mean sd mean sd mean sd f-test p-value 0.016" 1.5 64.25 1.42 61.9 1.20 60.15 2.87 58.1 4.05 9.728 0.000 1 47.5 1.18 43.4 2.84 43.5 2.17 41.5 3.24 10.333 0.000 0.5 40.1 2.16 38.35 2.22 38.6 1.43 36.35 3.38 4.123 0.013 0.019x 0.025" 1.5 174 3.64 173.20 6.72 171.60 8.60 158.10 2.95 16.015 0.000 1 113.20 4.26 113.60 6.88 111.10 9.90 97.20 3.88 13.579 0.000 0.5 106.65 6.05 108.95 5.44 107.70 10.03 91.55 6.58 12.684 0.000 table 2: lsd after anova for 0.016" and 0.019x0.025"heat activated arch wire ns:p>0.05 (not significant) s: p<0.05 (significant) hs: p<0.001 (highly significant). deflection (mm.) 0.016" 0.019x0.025" groups mean difference p-value mean difference p-value 1.5 nacl snf2 2.35 0.055 (ns) 0.80 0.764 (ns) apf 4.1 0.001 (hs) 2.40 0.370(ns) nf 6.15 0.000 (hs) 15.90 0.000 (hs) snf2 apf 1.75 0.148 (ns) 1.60 0.549 (ns) nf 3.8 0.003 (hs) 15.10 0.000 (hs) apf nf 2.05 0.092 (ns) 13.50 0.000 (hs) 1 nacl snf2 4.1 0.001 (hs) -0.40 0.894 (ns) apf 4 0.001 (hs) 2.10 0.487 (ns) nf 6 0.000 (hs) 16.00 0.000 (hs) snf2 apf -0.1 0.929 (ns) 2.50 0.409 (ns) nf 1.9 0.096 (ns) 16.40 0.000 (hs) apf nf 2 0.080 (ns) 13.90 0.000 (hs) 0.5 nacl snf2 1.75 0.112 (ns) -2.30 0.483 (ns) apf 1.5 0.171 (ns) -1.05 0.748 (ns) nf 3.75 0.001 (hs) 15.10 0.000 (hs) snf2 apf -0.25 0.817 (ns) 1.25 0.702 (ns) nf 2 0.071 (ns) 17.40 0.000 (hs) apf nf 2.25 0.043 (hs) 16.15 0.000 (hs) j bagh college dentistry vol. 29(1), march 2017 effect of different pedodontics, orthodontics and preventive dentistry 162 figure 1: load deflection curve for a) 0.016 ", b) 0.019x0.025" hant arch wires. discussion within one millisecond exposure to air, titanium-based alloys form a nanometer thickness layer of titanium oxide"10-20nm", in a process called passivation (5,6). however, this protective layer may be degraded following exposure to fluoride prophylactic agents. topical fluoride agents have been reported to cause corrosion of titanium based arch wires (4,5,7-10).it should be understood that the fluoride related effect depends on concentration of fluoride ions in the agent being used, the ph level of the agent, the duration of immersion, and the wires manufacturing characteristics (11). in the current study,the three point bending test is conducted. it is a standardized testing method useful for purely theoretical evaluations, offers a high level of reproducibility and allows comparison with other studies (12-14).the beam tests was carried out using a jig machined from stainless steelwith two barreled rods that set 15 mm apart to simulate a typical interbracket span (15). in the currrent study, a commercially available heat activated nickel-titanium archwires were tested with two cross sections 0.016" and 0.019x0.025". these arch wire gauges were selected because of their clinical popularity foraligning andlevelingphase to generate low force levels due to material properties which was adopted by the mbt method (16).wire deflections of 2mm and then the unloading forces at 0.5mm interval were selected because of its possible occurrence under clinical conditions(2). in the current study, the fluoride agents that were used differ in their fluoride ion concentration and ph value and according to manufacturer instructions they usedfor one minute per day topical application. the nacl were used as a control medium because ni-ti based arch wires has high corrosion resistance in nacl solution (17). nacl has adopted as a control medium by previous studies (18,19). the results of the current study are in agreement withother findings (23-25). sabaneet al.(23) and koushiket al.(24)foundsignificant reduction in unloading mechanical properties of ni-ti and cu ni-ti following exposure to fluoride agents after ninety minutes immersion time. ahrariet al. (25)found significant reduction in the unloading forces at lower deflection following immersion of ni-ti and cu ni-ti in 0.2% sodium fluoride solution for 24 hour. the results of the current study are in contrast to the finding by others(4,2022).walker et al.(4)reported that the application of acidic and neutral fluoride treatments have no significant effect on cu ni-ti (copper ni-ti that show a thermal properties) mechanical properties compared with distilled-water control treatment, but a reduction in the unloading mechanical properties of ni-ti wires was observed. it was assumed that the copper component in the cu niti archwires partially inhibit the activity of hydrofluoric acid; therefore, prevent fluoride related degradation in the mechanical properties of cu ni-ti wires. walker and his coworkers have noticed surface corrosion in ni-ti and cu ni-ti arch wires in their study. ramalingamet al.(22)reported that the mechanical properties of cu ni-ti archwires retrieved from patients who used a fluoride gel and phos-flur rinse for 30 days were not affected by fluoride agents but ni-ti wires had a reduction in the unloading force especially in gel group. schiff et al.(20,21)indicated that ni-ti wires were more susceptible to corrosion than cu ni-ti wires. in the current study, it seems that the fluoride related hydrogen embrittlement of titanium based b a j bagh college dentistry vol. 29(1), march 2017 effect of different pedodontics, orthodontics and preventive dentistry 163 alloysaffecting the wire unloading –related phase shift(4,10,26). hydrogen absorption and subsequent diffusion through the interstitial sites, dislocations, and grain boundaries reacting with lattice atoms forming titanium hydride which form a body centered tetragonal structure could interfere with the lattice's ability to undergo the unloading phase shift from the martensitic form to the austenitic form. this might be considered to be the cause of related degradation of mechanical properties of the alloy (4,24,27).this phenomenon might account for statistically significant differences in the unloading properties of the wires. in rectangular wires the load deflection mean during unloading was significantly reduced in all selected deflection points in nf gel group which has the highest concentration of fluoride among the test groups. the same condition was noticed in the round arch wires, nf gel caused reduction in the unloading forces at all deflection points. it also noticed that the snf2gel and apf rinse influenced on the round wires more than the rectangular wires. this could be attributed to the fact that 'the absorbed hydrogen in titanium alloys diffuses from the surface inward even at room temperature, and diffusion distance depends on the coefficient of hydrogen diffusion in materials; therefore, for thinner nickel-titanium and beta titanium wires, degradation in performance caused by hydrogen absorption probably occurs for a short immersion time'(26), which is in consistent with the results of the current study. in the current study, the reduction in the unloading forces might not be large enough to be clinically significant, since the wire was still exerting force levels within the optimal force range to produce tooth movement.the statistically significant difference occurred only after 60 minutes of fluoride exposure.in clinical situation, the real exposure time may be longer than 60 minutes because the patients are usually instructed to apply the fluoride agent before bed time and not to rinse their mouths, eat or drink for at least thirty minutes thereafter. also, the orthodontic arch wire could be kept in mouth for longer duration which increase the overall exposure time.in the current study, the margin of difference in the load values in fluoride agents was inbetween 6gm to 16gm compared to control group. although there was a statistically significant difference the amount of reduction, clinically, in the load was small. therefore, using fluoride agents seems to be suitable when using heat activated nickel titanium wires especially agents with lower concentration of fluoride ion such as phos-flur rinse and stannous fluoride gel agents. references 1. parvizi f, rock wp. the load/deflection characteristics of thermally activated orthodontic archwires. eur j orthod 2003; 25(4): 417-21. 2. gatto e, matarese g, di bella g, nucera r, borsellino c, cordasco g. load-deflection characteristics of superelastic and thermal nickel-titanium wires. eur j orthod2013; 35(1): 115-23. 3. lausmaa j, kasemo b, hansson s. accelerated oxide growth on titanium implants during autoclaving caused by fluoride contamination. biomater1985; 6:23-7. 4. walker mp, white rj, kula ks. effect of fluoride prophylactic agents on the mechanical properties of nickel-titanium-based orthodontic wires. am j orthoddentofacialorthop 2005; 127(6):662-9. 5. watanabe i, watanabe e. surface changes induced by fluoride prophylactic agents on titanium-based orthodontic wires. am j orthoddentofacialorthop 2003; 123(6):653-6. 6. elides t, bourauel c. intra oral aging of orthodontic materials; the picture we miss and its clinical relevance. am j orthoddentofacialorthop2005; 127(4):403-12. 7. kim h, johnson jw. corrosion of stainless steel, nickel-titanium, coated nickel-titanium, and titanium orthodontic wires. angle orthod1999; 69(1):39-44. 8. nakagawa m, matsuya s, shiraishi t, ohta m. effect of fluoride concentration and ph on corrosion behavior of titanium for dental use.j dent res 1999; 78(9):1568-72. 9. huang hh. effects of fluoride concentration and elastic tensile strain on the corrosion resistance of commercially pure titanium.biomater 2002; 23(1):5963. 10. yokoyama k, kaneko k, moriyama k, asaoka k,sakai j, nagumom. hydrogen embrittlement of niti superelastic alloy in fluoride solution. j biomed mater res 2003; 65(2):182-7. 11. huang hh. surface characterizations and corrosion resistance of nickel-titanium orthodontic archwires in artificial saliva of various degrees of acidity. j biomed mater res 2005; 74(4):629-39. 12. kapila s, sachdeva r. mechanical properties and clinical applications of orthodontic wires.am j orthoddentofacialorthop 1989; 96(2):100-9. 13. tonner ri, waters ne. the characteristics of superelastic ni-ti wires in three-point bending. part ii: intra-batch variation. eur j orthod 1994; 16(5):421-5. 14. bartzela tn, senn c, wichelhaus a. load-deflection characteristics of superelastic nickel-titanium wires.angle orthod 2007; 77(6):991-8. 15. wilkinsonpd, dysart ps, hood jaa, herbison g. load-deflectioncharacteristics of superelastic nickeltitanium orthodontic wires. am j orthoddento facial orthop 2002; 121: 483-95. 16. mclaughlin rp, bennett j, trevisi h. systemized orthodontic treatment mechanics.1st ed;st. louis: mosby co. 2001. 17. rondelli g, vicentini b. evaluation by electrochemical tests of the passive film stability of equiatomic ni-ti alloy also in presence of stresshttp://www.ncbi.nlm.nih.gov/pubmed/?term=kim%20h%5bauthor%5d&cauthor=true&cauthor_uid=10022183 http://www.ncbi.nlm.nih.gov/pubmed/?term=johnson%20jw%5bauthor%5d&cauthor=true&cauthor_uid=10022183 http://www.ncbi.nlm.nih.gov/pubmed/?term=%22the+angle+orthodontist%22%5bjour%5d+and+kim+h%2c+johnson+jw%5bauthor%5d+and+corrosion+of+stainless+steel%2c+nickeltitanium%2c http://www.ncbi.nlm.nih.gov/pubmed/?term=nakagawa%20m%5bauthor%5d&cauthor=true&cauthor_uid=10512392 http://www.ncbi.nlm.nih.gov/pubmed/?term=matsuya%20s%5bauthor%5d&cauthor=true&cauthor_uid=10512392 http://www.ncbi.nlm.nih.gov/pubmed/?term=shiraishi%20t%5bauthor%5d&cauthor=true&cauthor_uid=10512392 http://www.ncbi.nlm.nih.gov/pubmed/?term=ohta%20m%5bauthor%5d&cauthor=true&cauthor_uid=10512392 http://www.ncbi.nlm.nih.gov/pubmed/?term=%22journal+of+dental+research%22%5bjour%5d+and+1999%5bpdat%5d+and+nakagawa+m%2c+matsuya+s%2c+shiraishi+t%2c+ohta+m http://www.ncbi.nlm.nih.gov/pubmed/?term=huang%20hh%5bauthor%5d&cauthor=true&cauthor_uid=11762855 http://www.ncbi.nlm.nih.gov/pubmed/11762855 http://www.ncbi.nlm.nih.gov/pubmed/?term=kapila%20s%5bauthor%5d&cauthor=true&cauthor_uid=2667330 http://www.ncbi.nlm.nih.gov/pubmed/?term=sachdeva%20r%5bauthor%5d&cauthor=true&cauthor_uid=2667330 http://www.ncbi.nlm.nih.gov/pubmed/?term=1989%5bpdat%5d+and+kapila+s%2c+sachdeva+r.+%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=1989%5bpdat%5d+and+kapila+s%2c+sachdeva+r.+%5bauthor%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=bartzela%20tn%5bauthor%5d&cauthor=true&cauthor_uid=18004922 http://www.ncbi.nlm.nih.gov/pubmed/?term=senn%20c%5bauthor%5d&cauthor=true&cauthor_uid=18004922 http://www.ncbi.nlm.nih.gov/pubmed/?term=wichelhaus%20a%5bauthor%5d&cauthor=true&cauthor_uid=18004922 http://www.ncbi.nlm.nih.gov/pubmed/?term=bartzela+tn%2c+senn+c%2c+wichelhaus+a.+load-deflection+characteristics+of http://www.ncbi.nlm.nih.gov/pubmed/?term=rondelli%20g%5bauthor%5d&cauthor=true&cauthor_uid=10813744 http://www.ncbi.nlm.nih.gov/pubmed/?term=vicentini%20b%5bauthor%5d&cauthor=true&cauthor_uid=10813744 j bagh college dentistry vol. 29(1), march 2017 effect of different pedodontics, orthodontics and preventive dentistry 164 induced martensite.j biomed mater res 2000; 51(1):47-54. 18. alkhatieeb mm. the effect of fluoride prophylactic agents on load deflection of nickel titanium orthodontic wires (an in vitro study). a master thesis, orthodontic department, university of baghdad, 2006. 19. alavi s, farahi a. effect of fluoride on friction between bracket and wire. dent res j (isfahan) 2011; 8(1):s37-42. 20. schiff n, grosgogeat b, lissac m, dalard f. influence of fluoridated mouthwashes on corrosion resistance of orthodontics wires.biomater2004; 25(19):4535-42. 21. schiff n, boinet m, morgon l, lissac m, dalard f, grosgogeat b. galvanic corrosion between orthodontic wires and brackets in fluoride mouthwashes. eur j orthod 2006; 28(3):298-304. 22. ramalingam a, kailasam v, padmanabhan s, chitharanjan a. the effect of topical fluoride agents on the physical and mechanical properties of niti and cu nitiarchwires. an in vivo study. austorthod j 2008; 24(1):26-31. 23. sabane av, desh much sv, sable rb. the effect of fluoride prophylactic agents on the mechanical properties and surface topography of orthodontic arch wires. an in vitro study (part 1). j indorthodsoc 2009; 43(4):3-17. 24. koushik srh, hedge n, mahesh cm, chndrashekar bs, shetty b, mahendra s. effect of fluoride prophylactic agents on the mechanical properties of nickel-titanium wires. an in vitro study. j indorthodsoc 2011; 45(4):247-2. 25. ahrari f, ramazanzadeh ba, sabzevari b, ahrari a. the effect of fluoride exposure on the load deflection properties of superelastic nickel-titanium-based orthodontic archwires. austorthod j 2012; 28(1):72-9. 26. kaneko k, yokoyama k, moriyama k, asaoka k, sakai j. degradation in performance of orthodontic wires caused by hydrogen absorption during shortterm immersion in 2.0% acidulated phosphate fluoride solution.angle orthod 2004; 74(4):487-95. 27. wu sk, wayman cm. interstitial ordering of hydrogen and oxygen in tini alloys.actametallurgica1988; 36:1005-13. ةالخالص تيتانيوم ذات النشاط الحراري شعبية متزايدة في ممارسة تقويم األسنان بسبب قدرتها على إنتاج قوة مستمرة خفيفة قادرة على تحقيق -أصبح ألسالك النيكلمقدمة: المحافظة على نظافة الفم واالسنان لمرضى تقويم األسنان،فأخصائي تقويم األسنان يصفون مجموعة ألهمية ˝إستجابة بيولوجية مرغوب بها لتحريك األسنان، ونظرا متنوعة من المنتجات الوقائية من بينها التي تحتوي على الفلورايد. حميل األسالك ذات النشاط الحراري أثناء هدفت هذه الدراسة إلى التحقيق في آثار ثالثة منتجات وقائية تحتوي على الفلوريد على خصائص انحراف تهدف البحث: .مرحلة التفريغ بوصة مستديرة المقطع العرضي واآلخر 0.0.0ثمانين قطعة من األسالك الحرارية من شركة اورثوتكنولوجي ، نصفها كان بحجم المواد والطرق: لوقائية )فلوريد الصوديوم المتعادل جل ، و فلوريد القصدير جل أو بوصة مستطيل المقطع العرضي كانوا منغمسين في أحد منتجات الفلورايد ا0.0.0×0.0.0 73حاضنة في فلوريد الفوسفات الحامضي مضمضة فموية( أو في وسط ضابط كلورايد الصوديوم "المحلول الملحي العادي" في أنابيب مختبرية، تم وضعها في س القوى أثناء التفريغ اقيتم و في حوض مائيز مختبري قائم على أساس األنحناء النقطي الثالثي جهاتم إختبار العينات بواسطة. درجة مئوية لمدة ستين دقيقة anovaو lsdاإلحصائي بين عوامل مختلفة بإستخدام إختبارات لفرق. تم تحليل املم 0.0ملم و ., ملم 0..)التعطيل( عند مستوى اإلنحناء مجموعة الفلورايد المتعادل. وخصوصا في ريد يمكن أن يتسبب في إنقاص التفريغ من األسالكواستخدام الفلشير النتائج إلى أن إحصائيا، تالنتائج: يمكن االستنتاج بأن منتجات الفلورايد لها تأثير كمابناءاً على النتائج التي تأسست في هذه الدراسة فاقترح استخدام عامل وقائي مع تركيز أقل أليون فلوريد.اإلستنتاج: هذه الدراسة.محدود على سلوك انحراف تحميل األسالك الحرارية، بطريقة ليس لديهم تأثير كبير سريرياً على السلوك الميكانيكي لألسالك، كما وجدت في http://www.ncbi.nlm.nih.gov/pubmed/10813744 http://www.ncbi.nlm.nih.gov/pubmed/?term=schiff%20n%5bauthor%5d&cauthor=true&cauthor_uid=15120498 http://www.ncbi.nlm.nih.gov/pubmed/?term=grosgogeat%20b%5bauthor%5d&cauthor=true&cauthor_uid=15120498 http://www.ncbi.nlm.nih.gov/pubmed/?term=lissac%20m%5bauthor%5d&cauthor=true&cauthor_uid=15120498 http://www.ncbi.nlm.nih.gov/pubmed/?term=dalard%20f%5bauthor%5d&cauthor=true&cauthor_uid=15120498 http://www.ncbi.nlm.nih.gov/pubmed/15120498 http://www.ncbi.nlm.nih.gov/pubmed/?term=kaneko%20k%5bauthor%5d&cauthor=true&cauthor_uid=15387026 http://www.ncbi.nlm.nih.gov/pubmed/?term=yokoyama%20k%5bauthor%5d&cauthor=true&cauthor_uid=15387026 http://www.ncbi.nlm.nih.gov/pubmed/?term=moriyama%20k%5bauthor%5d&cauthor=true&cauthor_uid=15387026 http://www.ncbi.nlm.nih.gov/pubmed/?term=asaoka%20k%5bauthor%5d&cauthor=true&cauthor_uid=15387026 http://www.ncbi.nlm.nih.gov/pubmed/?term=sakai%20j%5bauthor%5d&cauthor=true&cauthor_uid=15387026 http://www.ncbi.nlm.nih.gov/pubmed/?term=degredation+inthe+performance+of+orthodontic+arch+wire+caused+by+hydrogen+absorption+during+short+immertion+in+2%25+acidulated+phosphate+fluoride+solution maha f.doc j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral and maxillofacial surgery and periodontics 111 assessment of serum interleukin-1β and its correlation with periodontal health status during pregnancy nadia m. kazem, b.d.s. (1) maha sh. mahmood, b.d.s, m.sc. (2) abstract background: pregnancy is a stressful state of increased inflammatory activity, and pregnancy – associated hormone changes can influence periodontal tissues, these inflammatory activity lead to production of inflammatory mediators. interleukin 1 beta (il-1β) is a potent pro-inflammatory cytokines that is consistently associated with periodontal diseases. this study was designed to determine the periodontal health status and detect the serum level of il-1β in the healthy pregnant women at first, second and third trimester and compare it with healthy non pregnant women, and determine its correlation with different clinical periodontal parameters. materials and methods: subjects included in the study were sixty six (66) healthy pregnant women with an age range of 20-35 years old. they were divided into three subgroups according to gestational age, as twenty two (22) women in each trimester. also the sample included fifteen (15) married, non pregnant women and didn’t take contraceptive pills, as control group with same age rang of 2035 years. clinical periodontal parameters were measured in this study (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level). blood samples were collected from all women under study (pregnant & non pregnant women) to asses concentrations of il-1β by mean of enzyme – linked immune sorbent assay (elisa). results: highly significant statistical differences were observed among the study groups regarding the gingival index (gi)with p-value( 0.007) and the percentages of bleeding on probing (bop) pvalue(0.00), a significant difference regarding the probing pocket depth ( ppd) with p-value (0.046) ,and non significant statistical differences regarding the plaque index (pli), p-value(0.6) and clinical attachment level (cal) with p-value (0.371). interleukin 1-beta ( il1β) serum level showed a highly statistical significant difference among the study groups with p-value (0.00).a pregnant women showed higher level than non pregnant with a higher value in the second trimester. conclusions: the present result revealed that the serum level of il-1β was higher in pregnant women than non pregnant women with a highly significant difference. the il-1β serum concentration reaches the maximum value in the second trimester of pregnancy. nevertheless there were weak correlations between clinical periodontal parameters and serum level of il-1β. key words: interleukin 1β, pregnancy, periodontal health status. (j bagh coll dentistry 2014; 26(2): 111-115). الخالصة یؤدي ھذا النشاط االلتھابي الى انتاج وسطاء التھابات مثل . كما ان التغیرات الھرمونیة المصاحبة للحمل تؤثر في انسجة ماحول االسنان , الحمل ھو حالة مرھقة من زیادة النشاط االلتھابي . الخلفیة تم تصمیم ھذه الدراسة لتحدید الحالة الصحیة النسجة ماحول االسنان . بیتا ھو من السایتوكینات الموالیة لاللتھابات القویة الذي یرتبط باستمرار مع امراض انسجة ماحول االسنان 1المدور الخلوي .سایتوكینات ال .وتحدید عالقتھ مع معلمات ماحول االسنان السریریة المختلفة , ت مختلفة من الحمل ومقارنتھا مع النساء غیر الحوامل بیتا في النساء الحوامل في فترا 1وكشف المستوى المصلي للسایتوكین امراءة حامل في كل 22سنة تم تقسیمھن الى ثالث مجموعات فرعیة وفقا لعمر او مرحلة الحمل الى ) 35-20(من النساء الحوامل تراوحت اعمارھن بین ) 66(وستین شمل البحث ستة .المواد وطرائق العمل كانت معلمات . سنة ) 35-20(كمجموعة مقارنة بنفس متوسط االعمار من ,من النساء المتزوجات غیر الحوامل ولم یاخذن حبوب منع الحمل ) 15(وشملت العینة خمسة عشر. فصل من فصول الحمل الثالثة تم جمع عینات الدم من جمیع النساء قید .دان االنسجة الرابطةماحول االسنان المستخدمة في ھذه الدراسة ھي مؤشر الصفیحة الجرثومیة و مؤشر التھابات اللثة والنزف عند التسمیر وعمق جیوب اللثة وفق بیتا باستخدام تقنیة مقایسة االنزیم المرتبط الممتز المناعیة1لتقییم التركیزات المصلیة للسایتوكین ) الحوامل وغیر الحوامل( الدراسة التوجد فروق فیما یتعلق بمؤشر . یتعلق بعمق جیوب اللثة ھناك فرق كبیر فیما ,یة عالیة بین مجموعات الدراسة یشأن مؤشر التھاب اللثة ومؤشر النزف عند التسمیر لوحظ وجود فروق ذات داللة احصائ.النتائج بیتا في الفصل 1اعلى قیمة للمدور الخلوي.واظھرت. یة بین مجموعات الدراسة مع بیتا فروقات ذات داللة احصائیة عال1اظھر المستوى المصلي للمدور الخلوي . الصفیحة الجرثومیة وفقدان االنسجة الرابطة .p=0.00.الثاني من الحمل بیتا 1المصلي للمدور الخلوي التركیز .النساء غیر الحوامل مع فروق ذات داللة إحصائیة عالیة بیتا كان أعلى في النساء الحوامل من 1كشفت النتیجة الحالیة أن المستوى المصلي من المدور الخلوي االستنتاج .بیتا1ك وجود عالقة ضعیفة بین المعلمات السریریة ومستوى المصل من المدور الخلوي ومع ذلك كان ھنا. یصل القیمة القصوى في الثلث الثاني من الحمل introduction periodontal disease is a common chronic inflammatory condition of infectious origin that results in breakdown of the periodontium .when the inflammation is confined to the soft tissue, it is called gingivitis. gingivitis is often caused by inadequate oral hygiene, and it is reversible with appropriate oral home care. untreated gingivitis may develop into periodontitis, which results in loss of connective tissue attachment and bone around teeth (1). in some individuals, gingivitis may exist as an independent clinical condition without progressing to periodontitis. how gingivitis progr (1)m.sc. student department of periodontics. college of dentistry. university of baghdad. (2)assistant professor. department of periodontics. college of dentistry. university of baghdad. esses to periodontitis is still unclear. on the other hand, periodontitis appears to be more specific inflammatory response to specific periodontal pathogens residing in the subgingival biofilm. nonetheless, it must be noted that, although bacteria are necessary for disease initiation, they are not sufficient to cause disease progression unless there is an associated inflammatory response within a susceptible host (2). the bacterial insult at the biofilm-gingival interface results in the direct destruction of host tissues through bacterial virulence factors such as collagenases and leukotoxins, and indirectly through the activation of host inflammatory cells such as neutrophils and macrophages ,which in response to the pathogenic biofilm release effector molecules such as prostaglandin e2 (3) and proinflammatory cytokines such as interleukinj bagh college dentistry vol. 26(2), june 2014 assessment of serum oral and maxillofacial surgery and periodontics 112 1beta (il-1β) (4), tumor necrosis factor-alpha (tnf-α) (5). these signaling molecules modulate the inflammatory process through the autocrine and paracrine activation of inflammatory cells, through mechanisms of chemotaxis (6). interleukin-1 is one of the major proinflammatory cytokine involved in the pathogenesis of periodontitis (7). its effects range from regulation of inflammatory mediators to catabolic effects on osteoclasts and activation of matrix metalloproteinases (8). pregnancy is a physiological process that affects profoundly even healthy women and there are many physiological ,anatomic and biochemical changes that mimic disease processes .(9)in most studies changes in oral health of pregnant women have been noticed in the condition of the dental hard tissue (dental caries) and soft tissue (periodontium) ,where many results showed an increase in the severity of dental caries and periodontal diseases especially gingivitis.(10,11) during pregnancy, progesterone levels increase 10-fold and estrogen level 30fold compared to those observed on menstrual cycle due to their continuous production. physiological changes in metabolism include oral microbial species, immune response and cell metabolism. the increase in progesterone results in greater vascular permeability, gingival edema, crevicular fluid levels and prostaglandin production, which may lead to gingival inflammation (12). the depth of periodontal pockets may increase as pregnancy progresses (13,14); however, the level of activity of the disease does not necessarily result in loss of periodontal clinical attachment level (14). there is, nonetheless, a consensus that pregnant women suffer a decline in periodontal health status. in spite of some studies showing no association between periodontitis and adverse perinatal outcomes (15) a growing number of studies indicate that the consequences of periodontitis activity during pregnancy may affect delivery outcomes, contributing towards prematurity, neonates with low birth weight, small for gestational age and fetal growth restriction (3,16,17). within the last two decades, a large number of cross-sectional, case-control, and cohort observational studies were carried out to investigate periodontal disease as a risk factor for adverse pregnancy outcomes (18). which involved miscarriage, preeclampsia, preterm birth (ptb), low birth weight (lbw), and/or preterm low birth weight (plbw) (19). results of these studies presented conflicting findings. most studies reported positive association (20-22). while the researches reporting no significant association took up a small portion (23,24). the classical theory of ‘focal infection’ speculated that oral foci of infection might be a contributing factor in triggering systemic inflammatory response. investigators hypothesized that hematogenous translocation of periodontal bacteria and their products or proinflammatory mediators from sites of periodontal infection into the fetal membranes, placenta, and amniotic cavity would induce pathological processes that could result in adverse outcomes (25). materials and methods subjects included in the study were drawn from patients attending the health care center of al-ameen city and al-alweea teaching hospital. the study groups included sixty six pregnant women with an age range of 20-35 years old. they were divided into three subgroups according to gestational age, as twenty two women in each trimester, also the sample included fifteen married, non pregnant women and didn’t take contraceptive pills, as control group with an age range of 20-35 years old. exclusion criteria: 1smokers, 2systemic antibiotic therapy or anti inflammatory therapy within the last three months, 3previous periodontal treatment within the last three months. clinical periodontal parameters were measured for all women by using periodontal probe by same examiner. the four surfaces of all teeth except 3rd molar were examined, the collected data included: pli, gi, bop, ppd and cal. two ml of venous blood were drawn from pregnant women and non pregnant (control group). blood sample was collected in a serum separator tube (sst) and allow samples to clot for 30 minutes before centrifugation for 15 minutes at 1000 rpm. collect serum and stored samples at –20°c. till used .the analysis was done by enzyme linked immuno sorbent assay (elisa) for quantitative determination of interleukin1β (il-1β) in serum. the laboratory analysis was done in the teaching laboratories of baghdad medical city. results non significant statistical differences were observed among the study groups regarding the plaque index (pli), p-value (0.6) (table 1).highly significant statistical differences were observed among the study groups regarding the gingival index (gi) with p-value (0.007) (table2), and the percentages of bleeding on probing (bop) p value (0.00) (table 3), a significant difference regarding the probing pocket depth ( ppd) with p-value (0.046) (table4). non significant j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral and maxillofacial surgery and periodontics 113 statistical differences were observed in clinical attachment level (cal) with p-value (0.371) (table5). interleukin 1-beta (il-1β) serum level showed a highly statistical significant difference among the study groups with p-value (0.00) (table6), also showed the higher value of il-1β in the second trimester. the correlation between means of serum il-1β and means of pli for each study group (table7). in the 1st trimester, there was a significant positive strong correlation between the means of pli & il-1β. while there were non significant positive correlation between the mean of plaque &il-1β in the 2nd, 3rd trimester and control group. also show positive non significant correlations between il-1β serum level and means of gi in the 1st and 2nd trimesters while there were negative non significant correlation in the 3rd trimester and control group (table7). il-1β serum concentration show positive but non significant correlations with the percentages of bleeding on probing (bop) (table 8) and probing pocket depth (ppd) (table9) in all study groups . positive non significant correlations also observed between il-1β &cal in the 1st trimester & control group while there is significant positive correlation in the 3rd trimester and there is no correlation in the 2nd trimester (table 9). table1: the mean values of pli of each study group with comparison of sig. among the groups groups mean pl.i + s.d. p.value sig. 1st 1.45 0.46 0.60 n.s. 2nd 1.25 0.58 3rd 1.43 0.36 control 1.06 0.48 anova = 2.578 table 2: the mean values of gi of each study group with comparison of sig. among the groups groups mean gi. + s.d. p.value sig. 1st 1.115 0.22 0.007 hs 2nd 1.231 0.36 3rd 1.346 0.37 control 1.050 0.10 anova = 4.297 table 3: the chi values of bop with comparison of sig. among the groups groups chi df p.value sig. 1st 60.682 3 0.00 hs 2nd 3rd control table 4: the mean values of ppd of each study group with comparison of sig. among the groups groups mean ppd. + s.d. p.value sig. 1st 2.22 2.09 0.046 s 2nd 2.54 1.96 3rd 2.72 1.90 control 0.93 1.94 anova = 2.783 table 5: the mean values of cal of each study group with comparison of sig. among the groups groups mean cal. + s.d. p.value sig. 1st 1.045 1.58 0.371 ns 2nd 1.22 1.52 3rd 1.36 1.46 control 0.53 0.96 anova =0.371 table 6: the mean values of il-1β of each study group with comparison of sig. among the groups groups mean il-1β + s.d. p.value sig. 1st 17.227 0.585 0.00 hs 2 nd 19.282 1.22 3rd 18.841 1.23 control 17.477 0.51 anova =21.754 table 7: the correlations between mean of pli, gi for each study group with the means of il-1β parameters serum il-1β groups r p. value pl 1st 0.659 0.01 2nd 0.196 0.382 3rd 0.247 0.268 control 0.358 0.19 gi 1st 0.13 0.564 2nd 0.191 0.395 3rd -0.271 0.223 control -0.235 0.399 table 8: the correlations between mean of bop for each study group with the means of il-1β parameter serum il-1β groups r p. value bop 1st 0.115 0.609 2nd 0.255 0.252 3rd 0.154 0.49 control 0.396 0.144 j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral and maxillofacial surgery and periodontics 114 discussion the present study showed that mean of plaque index was higher among pregnant groups especially in the first trimester followed by third trimester. this finding is in agreement with other study (26). this finding may be due to increased in the oral hygiene negligence during pregnancy especially in the fist trimester due to nausea and gag reflex. while during third trimester pregnant women may become restless, exhausted and anxious also it has been thought that pregnant women tend to avoid dental care because they believe poor oral health to be a routine consequence of pregnancy and because of fear that dental care would harm the fetus (27).the increased in the severity of gingivitis during pregnancy may be exaggerated due to arise in circulation level of progesterone affecting the gingival microvasculature (28). elevated progesterone levels in pregnancy enhance capillary permeability and dilatation, resulting in increased gingival exudate (29). in the present study there was gradual increase in the numbers and percentages of bleeding sites during pregnancy, this could be related to the increased level of estrogen and progesterone during pregnancy has a special effect on the periodontium, which would enhance the reaction to local stimulation and lead to the occurrence or increase of inflammation in gingival (30). this study reported that the probing depth scores increased gradually in the first, second and in the third trimester when reach maximum level, this result in accordance with other studies (31-33). this could be related to the extended period of the inflammation. also could be attributed to the quick effect of increasing progesterone & estradiol level which lead to the formation of prostaglandins & also the presence of high counts of prevotella intermedia (33). there was no statistical difference between pregnant and non pregnant women (control group) in the cal, this agreed with other study (34). in this study, they reported there was no support to the assumption that the wider distribution and increased severity of gingival inflammation in the course of pregnancy will cause lasting injuries to the periodontium. in this investigation we can notice the serum level of il-1β increased from first to the third trimester .this finding was in accordance with (35,36) who demonstrated that the serum level of il-1β, il-6 and il-8 increased during the gestation period, and reached the maximum value in the second trimester of pregnancy. this may be related to increased gingival inflammation during second trimester which will affect the level of inflammatory mediators produced by fibroblast and macrophage (37). nevertheless there were weak correlations between clinical periodontal parameters and serum level of il-1β, this may be due to small samples size in this study. as conclusion; pregnant women have higher pli, gi, bop, deeper periodontal pockets and more clinical attachment loss in comparison with non pregnant women. deep pockets and clinical attachment loss were low among pregnant women. the serum level of il-1β was higher in pregnant women than non pregnant women with a highly significant difference. the il-1β serum concentration reaches the maximum value in the second trimester of pregnancy. nevertheless there were weak correlations between clinical periodontal parameters and serum level of il-1β. references 1. kinane df. causation and pathogenesis of periodontal disease. periodontal 2000 2001; 25: 8-20. 2. papapanou pn, behle, jh, kebschull m, et al. subgingival bacterial colonization profiles correlate with gingival tissue gene expression. bmc microbiol 2009; 9: 221 3. offenbacher s, katz v, fertik g, collins j, boyd d, maynor g, mckaig r, beck j periodontal infection as a possible factor for preterm low birth weight. j periodontol 1996: 67: 1103–13. 4. giannopoulou c, kama jj, mombelli a. effect of inflammation, smoking, and stress on gingival crevicular fluid cytokine level. j clinical periodontology 2003; 30: 145–53. 5. ikezawa i, tai h, shimada y, komatsu y, galicia jc, yoshie h. imbalance between soluble tumor necrosis factor receptors type 1 and 2 in chronic periodontitis. journal of clinical periodontology 2005; 32: 1047–54. 6. kebschull m, demmer r, behle jh, pollreisz a, heidemann j, belusko pb, celenti r, pavlidis p, papapanou pn. granulocyte chemotactic protein 2 (gcp2/cxcl6) complements interleukin-8 in periodontal disease. j periodontal res 2008. 7. page rc. the role of inflammatory mediators in the pathogenesis of periodontol disease. j periodontol res 1991; 26: 230-42. 8. petropoulos g, mckay ij, hughes fj. the association between neutrophils numbers and interleukin-1a table 9: the correlations between mean of ppd, cal for each study group with the means of il-1β parameters serum il-1β groups r p. value ppd 1st 0.388 0.74 2nd 0.146 0.517 3rd 0.051 0.823 control 0.223 0.423 cal 1st 0.203 0.366 2nd 0.023 0.92 3rd 0.505 0.016 control 0.152 0.588 j bagh college dentistry vol. 26(2), june 2014 assessment of serum oral and maxillofacial surgery and periodontics 115 concentration in gingival crevicular fluid of smokers and non-smokers with periodontal disease. j clin periodontol 2004; 31: 390-95. 9. marilynn c, frederiksen. obstetric and gynecology. philadelphia: lippincott williams and wilkins; 2000. 10. yas ba. evaluation of oral health status, treatment needs, knowledge, attitude and behavior of pregnant women in baghdad governorate. m.sc. thesis, collage of dentistry, university of baghdad, 2004. 11. mohammad ca. the prevalence and severity of periodontal disease in different stages of pregnancy. m.sc. thesis, collage of dentistry, university of sulimania, 2005. 12. amar s, chung km: influence of hormonal variation on the periodontium in women. periodontol 2000 1994; 6: 79-87. 13. taani dq, habashneh r, hammad mm, batieha a: the periodontal status of pregnant women and its relationship with socio-demographic and clinical variables. j oral rehabil 2003; 30: 440-5. 14. moss kl, beck jd, offenbacher s. clinical risk factors associated with incidence and progression of periodontal conditions in pregnant women. j clin periodontol 2005, 32: 492-8. 15. gomes filho is, cruz ss, rezende ej, dos santos ca, soledade kr, magalhaes ma et al. exposure measurement in the association between periodontal disease and prematurity/low birth weight. j clin periodontol 2007; 34: 957–63. 16. xiong x, buekens p, fraser wd, beck j, offenbacher s. periodontal disease and adverse pregnancy outcomes: a systematic review. bjog 2006; 113: 13543. 17. vogt m, sallum aw, cecatti jg, morais ss. factors associated with the prevalence of periodontal disease in low risk pregnant women. reprod heal 2012; 9: 3. 18. arteaga-guerra jj, ceron-souza v, mafla ac. dynamic among periodontal disease, stress, and adverse pregnancy outcomes. rev salud publ (bogota) 2010; 12(2): 276–86. 19. cruz ss, costa mcn, gomes-filho is, rezende ejc, barreto ml, dos santos cast, vianna mip, passos js, cerqueira emm. contribution of periodontal disease in pregnant women as a risk factor for low birth weight. commun dent oral epidemiol 2009; 37(6):527–33. 20. dortbudak o, eberhardt r, ulm m, persson gr. periodontitis, a marker of risk in pregnancy for preterm birth. j clin periodontol 2005; 32(1): 45–52. 21. pitiphat w, joshipura kj, gillman mw, williams pl, douglass cw, rich-edwards jw. maternal periodontitis and adverse pregnancy outcomes. commun dent oral epidemiol 2008; 36(1): 3–11. 22. jeffcoat m, parry s, sammel m, clothier b, catlin a, macones g. periodontal infection and preterm birth: successful periodontal therapy reduces the risk of preterm birth. bjog 2011; 118(2):250–256. 23. mitchell lewis d, engebretson sp, chen j, lamster ib, papapanou pn. periodontal infections and preterm birth: early findings from a cohort of young minority women in new york. eur j oral sci 2001; 109(1):34–39. 24. noack b, klingenberg j, weigelt j, hoffmann t. periodontal status and preterm low birth weight: a case control periodontal status and preterm low birth weight: a case control study. j periodont res 2005; 40(4): 339-45. 25. clothier b, stringer m, jeffcoat mk. periodontal disease and pregnancy outcomes: exposure, risk and intervention. best pract res clin obstet gynaecol. 2007; 21(3):451–466. 26. hassan w. oral immune proteins and salivary constituents in relation to oral health status among pregnant women. a ph.d. thesis, college of dentistry, university of baghdad, 2007. 27. lachat mf, solnik al, nana ad, citron tl: periodontal disease in pregnancy. review of the evidence and prevention strategies. j perinat neonat nurs 2011; 25: 312–9. 28. lundgren d, magnussen b & lindhe j connective tissue alterations in gingivae of rats treated with oestrogens and progesterone. odontological review ( 1973)24, 49–58. 29. vittek j , rappaport sc, gordon gg, munnangi pr & southren a l. concentration of circulating hormones and metabolism of androgens by human gingiva. journal of periodontol 1979; 50: 254–64. 30. clothier b, stringer m, jeffcoat mk. periodontal disease and pregnancy outcomes: exposure, risk and intervention. best pract res clin obstet gynaecol 2007; 21(3):451–466. 31. miyazaki h, yamashita y, shirahama r, gotokimura k, shimada n, sogame a, takehara t. periodontal condition of pregnant women assessed by cpitn. j clinical periodontol 1991; 18: 751–4. 32. salameh rm. the periodontal status during pregnancy and intake of contraceptives. m.sc. thesis, college of dentistry, university of baghdad, 2000. 33. yalcin f, eskinazi e,soydinc m, basegmez c, issever h, isik g, berber l, has r, sabuncu h, onan v. the effect of sociocultural status on periodontal conditions in pregnancy. j periodontol 2002; 73: 178-82. 9roqaia f.doc j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 59 immunohistochemical expression of mmp2, vegf and d2-40 as biological markers of local invasion potential, angiogenesis and lymphangiogenesis in oral squamous cell carcinoma and verrucous carcinoma roqaia g. baqer, b.d.s. (1) bashar h. abdullah, b.d.s. m.sc., ph.d. (2) abstract background: verrucous carcinoma (vscc) is considered as a rare well differentiated carcinoma variant of scc with no metastatic potential. the aim of this study is to evaluate the immunohistochemical expression mmp-2, vegf and d2-40 expression in oscc and vscc. materials and methods: thirty formalin fixed paraffin embedded tissue blocks of oscc and another twelve vscc were collected and four micrometer thick sections were cut from each block and mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies to mmp-2, vegf and d2-40. results: there is no statistical difference between scc and vscc regarding the immunoexpression of mmp-2 and vegf. while the lymphatic vessels density were higher in scc than vscc conclusions: oscc and vscc bear similar local invasion and angiogenesis potentials when quantified with mmp-2 and vegf immunostaining respectively whereas oscc have higher lymphatic vessels density than their vscc as evaluated with d2-40 immunoexpression keywords: squamous cell carcinoma, verrucous squamous cell carcinoma, mmp-2, vegf, d2-40. (j bagh coll dentistry 2016; 28(3):59-64). introduction squamous cell carcinoma (scc) estimated to constitute approximately 94% of all oral malignancies (l). scc affects men more than women, usually in the middle to later decades of life. wide range of tumor features, including size and site, histologic malignant grade, perineural spread at the invasive front, lymphovascular invasion and tumor thickness have been described as major risk factors that adversely affect the prognosis for patients with oral scc (2). throughout the twentieth century this large set of head and neck scc (hscc) was clinically considered to be a rather uniform group; their worldwide variations in incidence and anatomic distribution were overwhelmingly attributed to demographic differences in the habits of exposure to smoking or chewing tobacco and drinking alcohol (l). with the advent of the twenty -first century this view has evolved because refinements of the molecular gene-technique are allowing for the recognition of new subtypes of hnscc that differ not only in etiology, but also in pathogenesis and clinical outcome (3). oral verrucous squamous carcinoma (ovscc) is considered a rare, low-grade and well-differentiated carcinoma, with less potential for lymph node metastasis than other oral carcinomas. (1)master student. department of oral diagnosis, college of dentistry, university of baghdad (2)professor. department of oral diagnosis, college of dentistry, university of baghdad ovc is also called ‘ackerman's tumor’ or ‘verrucous carcinoma of ackerman’ since it was first reported and described by ackerman in 1948. vscc, which accounts for 2.2-20% of all oral cancer, is mainly found in elderly males, particularly in tobacco smokers (4). ovc is regarded as a variant of squamous cell carcinoma with specific clinical, pathological and cytokinetic features, which also renders it different from squamous cell carcinoma (5). vscc is probably one of the most difficult and problematic lesions to diagnose in almost every instance. this is because the lesion is not cytologically malignant and therefore evidence of invasion is required for definite diagnosis (6). local invasion and distant metastases are the most important determining factors in the prognosis of malignant tumors. degradation of extracellular matrix (ecm) that surrounds tumor cells is one of the essential steps in tumor invasion and the development of metastasis (7). mmp-2, matrix metalloproteinase 2, also known as gelatinase a or type iv collagenase, is the most widely expressed of all the mmps and is found in most tissues and cells (8). angiogenesis has been shown in experimental animal models to be a crucial step in the successful growth, invasion and metastasis of the tumor. tumors will not grow beyond 2-3 mm in volume unless an intratumoral capillary network is constructed. up-regulation of vegf in tumors is therefore expected to be associated with increased angiogenesis and poor prognosis. however, the association between vegf j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 60 expression and prognosis, vascularity and disease progression in oral squamous cell carcinoma has not been fully addressed (9). lymphangiogensis which is the formation of lymphatic vessels from pre-existing one; play an important physiological role in homeostasis, metabolism and immunity. lymphatic vessel formation has also been implicated in a number of pathological conditions including neoplasm metastasis. recent evidence suggests an active role of malignant tumors in the induction of intratumoral and peritumorally morphangiogenesis (10). immunohistochemical markers specific for lymph vessel endothelium have been established recently, among the various antibodies specific for the endothelial cells of lymph vessels but do not stain vascular endothelial cells is the anti d240 monoclonal antibody which is relatively widely used (11). identification of lymphatic infiltration of tumor cells with d2-40 monoclonal antibody might make an objective and precise diagnosis of lymphatic metastasis (12). because of the obscure and variable biological behavior of oral vscc this study will consider different aspects of tumor dynamics such as the invasion potential, angiogenesis and lymphangiogenesis through the immunohistochemical evaluation of the mmp-2, vegf and d2-40 biological markers respectively in oscc and vscc. materials and methods thirty formalin fixed paraffin embedded tissue blocks which have been diagnosed as oscc dated from (2000-2012) and twelve formalinfixed, paraffin-embedded tissue blocks, which have been diagnosed as vscc dated from (1974 2012).collected from the archives of the department of oral & maxillofacial pathology/ college of dentistry/ university of baghdad; alshaheed ghazi hospital/medical city/ baghdad; al-kadhimiya teaching hospital and private laboratories archives. diagnostic confirmation was performed through examination of hematoxylin and eosin (h&e) stained sections. four micrometer thick sections were cut and mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies to mmp-2 to assess the local invasion, vegf to assess the angiogenic potential and d2 40 to assess the lyamphangiogenic potential. comparison regarding aforementioned markers expressions was carried out between the two tumors involved in the study. results the age range of the patients with oral squamous cell carcinoma was between 24 and 99 years with a mean of (59.23±14.96). for verrucous carcinoma the age ranged between 32 and 83 years with mean of (59.83 ±15.33), with no significant statistical difference in the age distribution between the two groups. themale: female ratio for squamous cell carcinoma was 18/12 (1.5:1) and it was 9/3(3:1) for verrucous carcinoma. no statistically significant difference was found regarding sex distribution between the groups. regarding the location, the tongue represented the most predominant site (26.7%) for squamous cell carcinoma and in verrucous squamous carcinoma cases the lower ridge and buccal mucosa showed similar frequency 4 (33.3%). histological examination showed that 15 cases (50%) of squamous cell carcinoma were well differentiated, followed by 11 cases (36.7%) were moderately differentiated and 4 cases (33.3%) were poorly differentiated. mmp-2 immunoreactivity was recognized in 28 (93.3%) of squamous cell carcinoma cases. in verrucous squamous carcinoma all cases (100%) showed positive immunoreactivity with no statistically significant difference in its expression between squamous cell carcinoma and verrucous squamous carcinoma (table-1). table 1: mmp-2 scores in oscc and vscc mmp-2 score oscc vscc frequency percent frequency percent score 0 2 6.7% 0 0% score 1 10 33.3% 1 8.3% score 2 9 30.0% 4 33.3% score 3 9 30.0% 7 58.3% total 30 100% 12 100% test chi-square 0.19 ns figure 1: mmp-2 immunoexpression in a. scc b. vscc j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 61 collectively, 35 of 42 cases (83.3%) were positive for vegf antibody with different score value. concerning the squamous cell carcinoma, 23 of 30 (76.7%) cases were positive to vegf antibody, whereas there were no vegf negative verrucous squamous carcinoma cases. no statistically significant difference in the vegf immune expression between the two groups (table-2). table 2: vegf score in oscc and vscc vegf score scc vscc frequency percent frequency percent score 0 7 23.3% 0 0% score 1 10 33.3% 3 25% score 2 5 16.7% 5 41.7% score 3 8 26.7% 4 33.3% total 30 100% 12 100% test chi-square 0.146 ns d2-40 immunostaining revealed positive lymphatic vessels immunoreactivity in all cases of squamous cell carcinoma. in verrucous squamous carcinoma 5 cases showed positive intratumoral lymphatic vessels density (41.6%), and 7 cases peritumoral lymphatic vessels density (58.33%). there was statistically significant difference in the lymphatic vessels density in all parameters (intratumoral, peritumoral and total lymphatic vessels) between the two groups (table3). lymphatic vessel invasion was detected in 19 (63%) of squamous cell carcinoma cases, it was not seen in any cases of verrucous carcinoma cases. tumor cells positivity to d2-40 antibody was recognized in 25 cases (83.3 %) of squamous cell carcinoma cases, and 10 cases (83.3%) of verrucous carcinoma cases .no statistically significant difference between the two groups (table-4). table 3: mean labeling index of the ilvd, plvd and tlvd in oscc and vscc scc vscc t-test ilvd 14.3±8.3 2.16±2.48 0.00** plvd 12.13±5.6 6.2±3.5 0.005* tlvd 26.43 ± 12.83 8.42 ± 5.52 0.0005* figure 2: vegf immunoexpression in a. scc b. vscc table 4: d2-40 tumor cell scores in oscc and vscc 40 score-d2 scc vscc frequency percent frequency percent score 0 5 16.7% 2 16.7% score 1 12 40% 2 16.7% score 2 12 40% 6 50% score 3 1 3.3% 2 16.7% total 30 100% 12 100% test chi-square 0.97 ns figure 3: d2-40 immunoexpression in a. scc b. vscc discussion assessment of mmp-2 immunostaining the role played by mmps in the progression of oral cancer appears increasingly interesting (l3) cells initially penetrate the basement membrane and migrate through the stoma. thus proteolysis of extracellular matrix macromolecules is a j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 62 crucial step in cancer invasion and metastasis. the cancer cells produce different extracellular matrix degrading enzymes, one of them is mmp-2, which play a role in the malignant behavior of the neoplasm (14). in this study 28(93.3%) of oscc cases were mmp-2 positve and (35.7%) of this positive cases showed low expression, this finding is near the finding of ruokolainen et al, (15 who found mmp2 expressed in (89%), while vicente et al (16) found mmp-2 in 32% of oral scc patients. in vscc cases mmp-2 expression was found in all cases (100%) and (8.3%) of cases were weak expression. although there is no statistical significant different between the expression of mmp-2 in vscc and oscc but the expression was higher in vscc. this agrees with tang et al ( 7) who used rt-pcr to test mmp-2 in oscc and vc and found that the expression of mmp2 mrna in verrucous carcinoma was significantly higher than that in welldifferentiated and moderately or poorly differentiated squamous cell carcinoma. this increased in mmp-2 expression in vscc may explain the aggressive local invasion of these tumors. the variations seen in the immmunopositivity rate among different studies could be due to the antibodies used and the processing techniques performed, as well as the heterogeneity of oscc which could be attributed to the epidemiological or biological differences between countries and population. besides, the production of mmps by normal cell is regulated by growth factors and/or cytokines, therefore heterogeneity also could be due to the expression of specific receptors for these enzymes (18) assessment of vegf immunostaining vegf is known to be one of the most pivotal angiogenic factors responsible for inducing tumor angiogenesis since it is the only angiogenic peptide known to act specifically on endothelial cell, and it is therefore considered as a leading candidate of angiogenesis (19). this study showed a positive expression to vegf antibody in 35cases (83.3%), 23 cases of oscc (76.7%) while all vscc cases were positive to different extents. in agreement with this study, sarkis et al,(20) and mărgăritescu et al (21) recorded (100%), (87.5%) and (87%) of oscc cases expressed vegf immunostaining respectively. the high expression of vegf may be explained by several points. tumor cells may produce vegf not only for vessel sprouting, but also to use it as an autocrine growth factor. some studies have demonstrated the existence of vegf receptors in oral scc cells (22) suggesting an autocrine role of vegf. mmps cleavages type iv collagen of the epithelial and vascular basement membrane also stimulates release of vegf from ecm-sequestered pools (23) assessment of d2-40 immunostaining: assessment of itlvd and ptlvd d2-40 positive lymphatic vessels were detected in all cases of scc both peritumorally and intra-tumorally. while positive intratumoral lymphatic vessels were detected in only 5 cases of the vscc (41.6%), and peritumorallymphatic vessels in 7 cases (58.33%). there is a significant difference in lvd between scc and vscc the mean of tlvd in scc (26.43 ± 12.83) while in vscc (8.42 ± 5.52). the high rate of lvd inscc than vscc may explain the high ability of scc to metastasis and it is evident that lymphangiogensis is an important feature of scc. assessment of lvi the invasion of tumor cells into lvs is one of the critical steps for the establishment of metastasis (24) lvi has been included as a new risk factor for cancer patients and its presence might be a predictor for postoperative prognosis (25) according to the results of the present study, d2-40 immunostaining highlighted the presence of lvi in 19 d2-40 positive lymphatic vessel cases (63.3%) out of 30 cases of squamous cell carcinoma. while lvi not found in any case of verrucous carcinoma. assessment of d2-40expression in tumor cells the positivity of tumor cells was detected as membranous and /or cytoplasmic localization. the distribution of immunostaining in tumor cells revealed d2-40 expression in 25 cases (83.3 %) of oscc and in vscc it expression in 10 cases (83.3%).there is no significant difference between two groups. sarkis et al. (20) detected positive tumor cells as membranous and/or cytoplasmic localization in 15(37.5%) cases of scc whereas normal oral mucosal cells showed no immunoreactivity. abdullah (26) found diffuse positive immunohistochemical staining in all verrucous carcinoma tissue samples extending from surface epithelium to the basal layer while in squamous cell papilloma only the basal cell layer show positive immunoreactivity. similarly, taher et al. (27) found that d240 was expressed in malignant squamous cells of j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 63 mucoepidermoid carcinomas unlike the mucous cells.from the above findings it is possible to assume that d2-40 may be a useful marker for distinguishing malignant neoplasms from benign epithelial neoplasms, moreover its expression may act as a good tumor marker in the differential diagnosis of certain carcinomas from their potential histologic mimics since the presence of morphological similarities between the cells of some neoplastic lesions and their normal or benign counterparts impose diagnostic difficulties in conclusion it seems that lvd is a crucial point in determining the metastatic potential of scc in comparison to vscc which showed a significant different in ilvd, plvd and tlvd. references 1. barnes l. surgical pathology of head and neck. 3rd ed. informa health care; 2009. 2. johnson n, franceschi s, ferlay j, ramadas k, schmid s, macdonald dg. squamous cell carcinoma in: barnes l, everson jw, reichart p, sidransky d (eds). world health organization classification of tumors. pathology and genetics of head and neck tumours. lyon: international. agency for research on cancer press; 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33(5): 369-74. 20. sarkis sa, abdullah bh, abdul-majeed ba, talabani ng. immunohistochemical expression of epidermal growth factor receptor (egfr) in oral squamous cell carcinoma in relation to proliferation, apoptosis, angiogenesis and lymphangiogenesis. head and neck oncol 2010; 2: 13. 21. mărgăritescu c, stfngă a, simionescu c, stepan a, pirici d, mogoantă l, raica m, ribatti d. vegf expression and angiogenesis in oral squamous cell carcinoma: an immunohistochemical and morphometric study. clin exp med 2010; 10: 209-14. 22. lalla rv, boisoneau ds, spiro jd, kreutzer dl. expression of vascular endothelial growth factor receptors on tumor cells in head and neck squamous cell carcinoma. arch otolaryngol head neck surg. 2003; 129: 882-888. 23. kumar v, cotran rs, robbins sl. robbins basic pathology. 8th ed. saunders. 2006. 24. siriwardena bsms, kudo y, ogawa i, udagama pk, tilakaratne wm, takata t. vegf-c is associated with lymphatic status and invasion in oral cancer. j clin pathol 2008; 61: 103-8. 25. soares ab, ponchio l, juliano pb, de aravjo vc, j bagh college dentistry vol. 28(3), september 2016 immunohistochemical oral diagnosis 64 altemani a, lymphatic vascular density and lymphangiogenesis during tumor progression of carcinoma ex pleomorphic adenoma. j clin pathol 2007; 60: 995-1000. 26. abdullah bh. d2-40 as a potential marker that differentiate verrucous carcinoma from squamous cell papilloma. iraqi j med sci 2012; 10: 243-8. 27. taher mg, abdullah bh, al-khuri le. immunohistochemical expression of cd34 as biological marker of angiogenesis and expression of d2-40 as marker of lymphangiogenesis in mucoepidermoid carcinoma of salivary glands. j pioneering med sci 2012; 2(3):126. j bagh college dentistry vol. 30(3), september 2018 evaluation of 1 evaluation of hematocrit level, red blood cells and white blood cells counts in blood from patients with different severities of periodontal diseases chinar jabbar ali, b.d.s. (1) maha abdul aziz ahmed, b.d.s., m.sc. (2) abstract background: anemia of chronic disease (acd) occurs in the presence of chronic infection, inflammatory conditions or neoplastic conditions despite of adequate iron and vitamins storage. gingivitis is the inflammation of the gingiva, periodontitis is the inflammation in the periodontium that extend deeper with loss of connective tissue attachment and supporting bone. the main pathogenesis of periodontal diseases and acd is immune activation. aims of study: determine and compare the clinical periodontal parameters (plaque index (pli), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal)). evaluate the hematocrit (hct) level, red blood cells (rbcs) count and white blood cells (wbcs) count. assess the correlations between the clinical periodontal parameters and hematological parameters at patients had gingivitis, chronic periodontitis (cp) with different severities (mild, moderate and severe) with healthy periodontium subjects. materials and methods: 35-50 years old, 150 male subjects were included in this study. they were divided into three study groups: group of 30 patients with gingivitis, group of 90 patients with cp which subdivided into (mild cp=30 patients, moderate cp =30 patients, severe cp =30 patients) and control group 30 subjects with clinically healthy periodontium. blood samples were collected then by automated blood analyzer the hct, rbcs and wbcs were evaluated. results: comparisons among groups and subgroups revealed significant differences in hct and wbcs, while rbcs was non-significant. means values of rbcs count showed reduction in mild and severe cp subgroups. while, the hct and wbcs mean values increased in patients with periodontal disease. the correlations between the clinical periodontal parameters with wbcs and rbcs were almost non-significant but, with hct was mostly significant negative correlations. conclusion: inflammatory and immune responses in periodontal diseases caused change in different hematologic parameters which could contribute to the development of anemia of chronic disease. key words: anemia of chronic disease, periodontitis, rbcs, wbcs, hct. (j bagh coll dentistry 2018; 30(3): 1-6) introduction anemia of chronic disease (acd) anemia that is occurs in inflammatory conditions, infections and tumors. this type of anemia occurs despite adequate iron stores and no bone marrow dysfunction (1). the pathogenesis of acd is complex and multifactorial, linked to the underlying chronic disease, but mainly due to alterations in iron balance that derived from the immune activation. at least three major immunedriven mechanisms contribute to the development of acd which are: the reduction in the life span of erythrocytes, the impaired proliferation of erythroid progenitor cells and the increased uptake and retention of iron within cells of the reticuloendothelial system (2). the inflammation develops in the oral host tissue as long as there is plaque accumulation along the gingival margin that lead to either gingivitis in which it remains localized coronal to the junctional epithelium or to periodontitis in which it extends deeper, leading to loss of connective tissue attachment and supporting bone (3). (2) professor, department of periodontics, college of dentistry, university of baghdad. cp is the most familiar type of periodontal disease and mostly seen in adults which is proceeds relatively slow. (4) there is a possible pathogenic relation between anemia and periodontal disease. bacteria that cause periodontal diseases stimulate fibroblasts, keratinocytes and macrophages of periodontium, that leads to release of inflammatory cytokines such as tumor necrosis factor α (tnf-α), prostaglandin e2 (pge2) and interleukins (il): il-1, il-6 and il-12. cytokines can cause biological effects or tissue damages such as destruction of connective tissues and alveolar bones. the increase of some inflammatory response cytokines such as tnf-α, interferon (inf) and il-1 have been observed in patients with acd. because of a similar role of cytokines in pathogenesis of both acd and periodontitis (1). a relationship between these two diseases was proposed. the aim of this study was to evaluate whether periodontal diseases in different severities contribute to the development of acd by estimating hct, the counts of red blood cells (rbcs) and white blood cells (wbcs). (1) ministry of health, kurkuk, iraq j bagh college dentistry vol. 30(3), september 2018 evaluation of 2 materials and methods the human sample consisted of 150 males with age range of 35-50 years. the subjects were recruited from periodontics department, at the teaching hospital, college of dentistry, university of baghdad as well as from the iraqi national blood bank in baghdad. written consents were obtained from all of them. the participants divided into three groups: control group (clinically healthy periodontium), gingivitis group and cp group which subdivided according to the severity of clinical attachment loss (5) into subgroups (mild, moderate and severe cp), 30 subjects in each group and subgroup. the inclusion criteria were: apparently systemically healthy subjects, at least twenty teeth present, all teeth included except third molar and patients with chronic periodontitis must have a minimum of four sites with ppd of ≥ 4 mm and cal of 1-2 mm or more. it was carried out according to the international classification system for periodontal disease (6). patients with gingivitis characterized by the presence of signs and symptoms of gingival inflammation (7) and without periodontal pocket or clinical attachment loss. clinically healthy periodontium, characterized by the absence of any signs and symptoms of gingival inflammation and without periodontal pocket or clinical attachment loss. while, the exclusion criteria were: females (to eliminate bias as females are more prone to hormonal imbalance during puberty, reproductive and menopausal age (4)) smokers, alcohol drinkers, patients undergone periodontal treatment and/or used a course of anti-inflammatory, antimicrobial or other medications (ex: iron supplement) in the 3 months before the study and presence of systemic diseases. full medical and dental history, medications, smoking status were taken from all participants. complete clinical periodontal parameters examination using marquis periodontal probe which included: pli (8), gi (7), bop% and ppd (9) and cal (5). four sites were examined per tooth (mesial, buccal/ labial, distal and lingual/ palatal). then 2.5 ml of blood was collected from each subject into ethylene diamine tetra acetic acid (edta) tube for hct, rbcs and wbcs evaluation by automated blood analyzer as in sufficient blood edta ratio can cause clotting or hemolysis of blood sample (10). in this study the statistics used were: standard deviation (s.d.), mean, analysis of variance test, bonferroni and pearson’s correlation coefficient (r) test. levels of significance (sig.) were used: non significant (ns): p > 0.05, significant (s): p ≤ 0.05. we clarify that this study involving human subjects is in accordance with helsinki declaration of 1975 (11). results statistically s differences among gingivitis group and cp subgroups were found in pli, gi, bop score 1, ppd and cal, as shown in table 1. statistically s differences among control, gingivitis groups and cp subgroups were detected in hct and wbcs, while rbcs was ns. the highest mean value of hct (48.79±4.05) was at the gingivitis group and the control group demonstrated the lowest mean value (45.76±4.18). the highest mean value of rbcs (5.62±0.620) was at the gingivitis group and the mild cp subgroup demonstrated the lowest mean value (5.41±0.427). the highest mean value of wbcs (7.95±2.64) was at the mild cp subgroup and the control group demonstrated the lowest mean value (6.58±1.59), as shown in table 2. the statistical analysis using bonferroni test for the wbcs mean values revealed ns differences except the s difference between control group with severe cp subgroup, this can be noticed in table 3. while, hct mean values revealed ns differences except, the s difference between control group with gingivitis group (table 4). the hct correlations results were: s negative correlations (r=0.579, r=0.690) with pli at moderate and severe cp subgroups, for gi was s negative (r=0.435) at severe cp, for bop score 1 they were s negative (r=0.356, r=0.551, r=0.609, r=0.614) at gingivitis group and cp subgroups, (table 5). the rbcs showed s negative correlations with pli, ppd at mild cp subgroup (r=0.465, r=0.846), s negative correlation for bop score 1 at moderate cp (r=0.417) and s negative correlation with cal at severe cp(r=0.458) (table 6). the results of wbcs, revealed s positive correlation with bop score 1 and cal at moderate cp subgroup (r=0.453, r=0.375), as shown in table 7. j bagh college dentistry vol. 30(3), september 2018 evaluation of 3 table 1: statistical analysis of clinical periodontal parameters for cp subgroups, gingivitis and control groups (one-way anova test used) groups and subgroups pl i gi bop score 1 ppd cal mean ±s.d. mean ±s.d. mean ±s.d. mean ±s.d. mean ±s.d. control 0.21 0.09 1.106 0.073 gingivitis 0.51 0.57 1.116 0.179 8.90 3.30 mild cp 1.87 0.49 1.370 0.364 22.9 13.76 4.93 0.99 1.68 0.204 moderate cp 1.95 0.40 1.625 0.429 34.1 10.86 5.33 1.31 3.57 0.291 severe cp 2.10 0.24 1.872 0.383 49.1 10.42 5.66 1.24 6.36 0.641 f-test 111.761 484.212 83.782 24.88 928.703 p-value 0.000 0.000 0.000 0.000 0.000 sig. s s s s s significant (s): p ≤ 0.05 table 2: statistical analysis of hct level, rbcs count and wbcs count in blood for cp subgroups, gingivitis and control groups. groups and subgroups hct rbcs wbcs mean ±s.d. mean ±s.d. mean ±s.d. control 45.76 4.18 5.45 0.408 6.58 1.59 gingivitis 48.79 4.05 5.62 0.620 7.28 1.53 mild cp 47.98 3.91 5.41 0.427 7.95 2.64 moderate cp 48.53 3.89 5.54 0.408 7.49 1.40 severe cp 48.01 3.71 5.42 0.465 7.93 1.26 f-test 2.601 1.092 2.542 p-value 0.038 0.363 0.042 sig. s ns s significant (s): p ≤ 0.05, hct level (percentage), rbcs count (number of cells ×1012/l), wbcs count (number of cells × 109/l). table 3: comparisons of mean values of wbcs count parameter between all pairs of groups and subgroups. groups and subgroups mean difference p-value sig. control gingivitis -0.553 1.000 ns mild cp -1.226 0.077 ns moderate cp -0.771 0.912 ns severe cp -1.32 0.041 s gingivitis mild cp -0.673 1.000 ns moderate cp -0.218 1.000 ns severe cp -0.769 0.924 ns mild cp moderate cp 0.454 1.000 ns severe cp -0.096 1.000 ns moderate cp severe cp -0.550 1.000 ns bonferroni test used. table 4: comparisons of mean values of hct parameter between all pairs of groups and subgroups. groups and subgroups mean difference p-value sig. control gingivitis -2.896 0.004 s mild cp -2.086 0.402 ns moderate cp -2.636 0.098 ns severe cp -2.113 0.377 ns gingivitis mild cp 0.810 1.000 ns moderate cp 0.260 1.000 ns severe cp 0.783 1.000 ns mild cp moderate cp -0.550 1.000 ns severe cp -0.026 1.000 ns moderate cp severe cp 0.523 1.000 ns bonferroni test used. j bagh college dentistry vol. 30(3), september 2018 evaluation of 4 table 5: correlation between hct with the clinical periodontal parameters of the gingivitis group and cp subgroups. cal ppd bop score 1% gi pli groups and subgroups p r p r p r p r p r 0.050 -0.356 0.067 -0.333 0.704 0.071 gingivitis 0.916 -0.020 0.875 -0.083 0.002 -0.551 0.062 -0.345 0.258 -0.213 mild cp 0.731 0.065 0.647 -0.240 0.000 -0.609 0.121 -0.289 0.001 -0.579 moderate cp 0.176 -0.254 0.113 0.603 0.000 -0.614 0.016 -0.435 0.000 -0.690 severe cp pearson’s correlation coefficient (r) test used. table 6: correlation between rbcs count with the clinical periodontal parameters of the gingivitis group and cp subgroups. cal ppd bop score 1 gi pli groups and subgroups p r p r p r p r p r 0.116 -0.288 0.322 -0.184 0.610 0.095 gingivitis 0.853 -0.035 0.034 -0.846 0.540 -0.116 0.278 -0.205 0.010 -0.465 mild cp 0.673 0.080 0.371 -0.450 0.022 -0.417 0.145 -0.272 0.090 -0.315 moderate cp 0.011 -0.458 0.545 0.253 0.118 -0.291 0.103 -0.304 0.172 -0.256 severe cp pearson’s correlation coefficient (r) test used. table 7: correlation between wbcs count with the clinical periodontal parameters of the gingivitis group and cp subgroups. cal ppd bop score 1 gi pli groups and subgroups p r p r p r p r p r 0.897 0.024 0.136 0.274 0.722 0.066 gingivitis 0.408 0.157 0.861 -0.093 0.299 0.196 0.297 0.197 0.514 0.124 mild cp 0.041 0.375 0.521 0.331 0.012 0.453 0.527 -0.120 0.377 -0.167 moderate cp 0.438 -0.147 0.841 -0.085 0.590 -0.102 0.742 -0.063 0.911 -0.021 severe cp pearson’s correlation coefficient (r) test used discussion the clinical periodontal parameters (pli, gi, bop score 1, ppd and cal) demonstrated s differences among gingivitis group and cp subgroups, this in agreement with other studies (12,13). periodontal disease result from neglected oral hygiene and accumulated dental plaque, it is the result of interaction between host immuneinflammatory reaction and dental plaque bacteria that lead to destruction of periodontal ligament fibers, resulting in clinical loss of attachment and resorption of the alveolar bone (9). the results of hct revealed s difference among control, gingivitis groups and cp subgroups. the results coincide with other studies (1,4). while, disagree with previous studies (14,15). the hct level depends on rbcs and mean corpuscular volume (mcv) levels, if one or both increased, the hct level increase and the opposite is true (3). the rbcs mean values increased in gingivitis group and moderate cp subgroup, hence, the hct level was increased. this was clearly shown with maximum hct value among the gingivitis group. the hct is not an indication about presence of anemia or blood loss only, but also provide important indication about the blood capacity to transport oxygen as well as, the body hydration state. the hct increased due to under hydration that decreases plasma volume (16). hct result showed almost s negative correlations with periodontal parameters. this could be attributed to the hydration state of the patients, as the under hydration state could cause reduction in the salivary flow rate (17). decreased salivary flow rate lead to enhance the plaque buildup and increase the incidence of dental caries and periodontal disease (9). the salivary flow rate level decreased in gingivitis group and cp subgroups (18). the rbcs results demonstrated ns difference among control, gingivitis groups and cp subgroups, although the means values were within the normal range but they showed reduction in mild and severe cp subgroups. these results coincide with previous studies (12,14). while, disagree with other studies (1,4). in acd, increase in some inflammatory cytokines such as tnfα, interferon (inf) and il-1 have been reported. these cytokines lead to decreased rbc life span, impaired development of erythroids, decrease erythropoietin response, interfere with the differentiation of erythroids (1). the rbcs correlation results in agreement with khan et al., (15), periodontal inflammation suggested to down regulate erythropoesis by proinflammatory j bagh college dentistry vol. 30(3), september 2018 evaluation of 5 cytokines and reduce rbcs count (19). the wbcs results revealed s difference among the control, gingivitis groups and cp subgroups. these results agree with previous studies (3,12), while they disagree with other finding (20). this could be attributed to the activated response of total leukocytes since, they are the first line of body defense during infection and inflammation (21). in periodontitis and gingivitis there are elevations in neutrophils numbers that result in increase in leukocytes numbers (22). there were lack of literature which correlate wbcs count with the clinical periodontal parameters. with the incidence of subgingival pathogens exudation and migration from the nearby capillaries of large number of leukocytes to the site of infection occur that involved in the first line of defense against bacterial pathogens (23). conclusion periodontal diseases are mild inflammatory conditions, they are low grade infection that may lead to signs of anemia however, they are not very severe as observed in other systemic diseases that can cause acd (e.g. rheumatoid arthritis, malignancy and others). references 1. jenabian n, dabbagh sattari f, salar n, bijani a, ghasemi n. the relation between periodontitis and anemia associated parameters. jpd 2013;2:(3) 27-33. 2. poggiali e, de amicis m, motta i. anemia of chronic disease: a unique defect of iron recycling for many different chronic diseases. eur j intern med. 2014; 25: 12-7. 3. patil r. evaluation of haematological changes in patients with chronic periodontitis and gingivitis in comparison to healthy controls – a clinical study. j dent allied sci 2013;2(2):49-53. 4. patel md, shakir qj, shetty a. interrelationship between chronic periodontitis and anemia: a 6-month follow-up study. j indian soc periodontol 2014;18: 19-25. 5. american academy of periodontology. parameter on chronic periodontitis. j periodontol 2000;71: 853-5. 6. lang np, bartold pm, cullinam m et al. international classificationworkshop. consensus report: chronic periodontitis. annals periodontol.1999; 4:53. 7. lӧe h. the gingival index, the plaque index & the retention index system. j periodontol. 1967;38:610-6. 8. silness j, lӧe h. periodontal disease in pregnancy ιι. acta odontol scand.1964; 24: 747-59. 9. carranza af, newman gm, takei hh, klokkevold rp. carranza’s clinical periodontology. 12th ed, 2015. elsevier, saunders 10. mckenzie sb, williams jl, landis-piwowar k. clinical laboratory hematology. pearson education; 2004. 11. world medical association. declaration of helsinki: ethical principles for medical research involving human subjects. jama 2013 ;20: 2191-4. 12. pejcic a, kesic l, pesic z, mirkovic d, stojanovic m. white blood cell count in different stages of chronic periodontitis. acta clin croat 2011; 50:159‑67. 13. muppalla ch, theyagarajan r, ari g, mahendra j. evaluation of systemic markers related to anemia in peripheral blood of patients with chronic generalized severe periodontitis a comparative study. int j cur res rev 2016; 8(9) 59-63. 14. prakash s, dhingra k, priya s. similar hematological and biochemical parametres among periodontits and control subjects. eur j dent 2012; 6(3):287-94. 15. khan ns, luke r, soman pr, krishna pm, safar ip, swaminathan sk. qualitative assessment of red blood cell parameters for signs of anemia in patients with chronic periodontitis. j int soc prevent communit dent, 2015; 5:476-81. 16. fischbach f. a manual of laboratory and diagnostic tests. lippincott williams and wilkins. philadelphia, 6th ed 2000. 17. ship ja, fisher dj. metabolic indicators of hydration status in the prediction of parotid salivary-gland function. arch oral biol,1999; 44 (4): 343-50. 18. talib jh, ahmed am. assessment of salivary αamylase and flow rate levels and their correlation with gingivitis and severity of chronic periodontitis. j bagh coi dentist, 2016; 28 (4) 115-21. 19. nair s, faizuddin m, jayanthi d. anemia and periodontitis: an enigma?. iosr –jdms, 2013; 11(4): 71-8. 20. sanatosh hn, david ch, kumar h, sanjay cj, bose a. chronic periodontitis and anaemia of chronic disease: an observational study. arch orofac sci 2015; 10(2):57-64. 21. rudin sr. laboratory tests and their significance in walter hall. crit decs periodontol 2003;8:4-6. 22. loos bg. systemic markers of inflammation in periodontitis. j periodontol. 2005; 76: 2106-15. 23. nibali l, d'aiuto f, griffiths g, patel k, suvan j, tonetti ms. severe periodontitis is associated with systemic inflammation and a dysmetabolic status: a case-control study. j clin periodontol, 2007; 34(11): 931-7. الخالصة : فقر الدم الناتج من األمراض المزمنة هو فقر الدم الذي يحدث في وجود عدوى مزمنة والحاالت االلتهابية او حاالت االورام على الخلفية التهاب األنسجة الداعمة لألسنان الذي يمتد أعمق مع ،وفيتامين كافيان. التهاب اللثة هو التهاب في نسيج اللثةالرغم من وجود مخزون حديد فقدان مرفق األنسجة الضامة والعظام الداعمة. السبب الرئيسي لتطور امراض أنسجة ما حول األسنان وفقر الدم الناتج من األمراض المزمنة هو التنشيط المناعي النزف اللثة، مؤشر التهاب الجرثومية، مؤشر الصفيحة السريرية )مؤشر أنسجة ما حول األسنانمؤشرات تحديد ومقارنة الدراسة:أهداف عدد كريات الدم و عدد كريات الدم الحمراء ،نسبة اللزوجة في الدمسريريا( و الرابطة األنسجة ومستوى اللثة جيوب عمق التسبير، عند العالقات بينهم في مجموعات الدراسة التي تشمل: مجموعة التهاب اللثة ومجموعة التهاب اللثة المزمن مع الشدة وتحديدالبيض في الدم .المختلفة التي قسمت الى: طفيف، معتدل وحاد مع مجموعة ضابطة )لثة صحية سريريا( j bagh college dentistry vol. 30(3), september 2018 evaluation of 6 تقسيمهم الى ثالثة مجاميع دراسية كاالتي: شخص من الذكور تم شملهم في هذه الدراسة. تم 005 ،( سنة50-05بين ) :والطرق المواد ( مريض )قسمت المجموعات فرعية وهي: التهاب اللثة المزمن 05( مريض ومجموعة التهاب اللثة المزمن )55مجموعة التهاب اللثة ) ضابطة )لثة صحية مجموعة ( مريض في كل مجموعة فرعية( 55التهاب اللثة المزمن الحاد ) ،التهاب اللثة المزمن المعتدل ،الطفيف عدد كريات الدم ،( شخص. تم سحب عينات الدم وبعد ذلك عن طريق جهاز تحليل الدم الذاتي تم تحديد نسبة اللزوجة في الدم55) سريريا( .عدد كريات الدم البيضو الحمراء عدد كريات الدم البيض. في و في الدم المقارنة بين المجموعات والمجموعات الفرعية أظهرت فرق معنوي لكل من: نسبة اللزوجة :النتائج حين عدد كريات الدم الحمر كان فرق غير معنوي. المتوسط الحسابي لعدد كريات الدم الحمراء اظهر انخفاض في مجموعة التهاب اللثة المزمن المعتدل. في حين المزمن الطفيف ومجموعة التهاب اللثة المزمن الحاد ولكن ازداد في مجموعة التهاب اللثة ومجموعة التهاب اللثة كريات الدم البيض ازداد في مرضى أمراض أنسجة ما حول األسنان. العالقة بين مؤشرات أنسجة و المتوسط الحسابي لنسبة اللزوجة في الدم وجة في الدم ما حول األسنان السريرية وكريات الدم البيض وكريات الدم الحمر كانت عالقة غير معنوية على األغلب لكن مع نسبة اللز سلبية.كانت غالبا عالقة معنوية األستجابة األلتهابية والمناعية ألمراض أنسجة ما حول االسنان سببت تغيير في مختلف المؤشرات الدموية التي من الممكن أن :االستنتاج تساهم في حدوث فقر الدم الناتج عن األمراض المزمنة. ،عدد كريات الدم البيض ،عدد كريات الدم الحمراء ،التهاب األنسجة الداعمة لألسنان ،فقر الدم الناتج من األمراض المزمنة الكلمات الدالة: .نسبة اللزوجة في الدم 1ala'a f.docx j bagh college dentistry vol. 28(3), september 2016 effect of mouth rinses restorative dentistry 1 effect of mouth rinses on surface roughness of two methacrylate-based and siloraine-based composite resins ala’a jawad kadhim, b.d.s., m.sc. (1) abstract background: various fluids in the oral environment can affect the surface roughness of resin composites. this in vitro study was conducted to determine the influence of the mouth rinses on surface roughness of two methacrylatebased resin (nanofilled and packable composite) and siloraine-based resin composites. materials and methods: disc-shaped specimens (12 mm in diameter and 2mm in height) were prepared from three types of composite resin materials: filtek™ z350 xt, filtek™ p60 and filtek™ p90.thirty specimens were prepared from each composite type and subdivided into three subgroups (n=10) according to the type of treatment solution: distilled water (control), listerine (alcohol-containing), sensodyne pronamel (alcohol free fluoridecontaining).each subgroup was immersed in 20 ml of treatment solutions and incubated at 37°c for 24 hr and then subjected to surface roughness test by profilometer .the resulting data were statistically analyzed using anova and lsd test at0.05 significance level. results: the results of this study showed that both mouth rinses irrespective of the presence or absence of alcohol resulted in significant increase in the surface roughness of the tested resin composite materials compared to control with no significant difference between the two mouth rinses. comparison among the three types of resin in each treatment solution showed that there was a statistically high significant difference in surface roughness between all subgroups conclusion: both alcohol-containing and alcohol-free fluoride containing mouth rinses cause highly significant increase in surface roughness of composite resins. composite changes depended on the material itself rather than the mouth rinse solution used. key words: composite resin, mouth rinses, siloraine, surfaces roughness. (j bagh coll dentistry 2016; 28(3):1-7). introduction one of the factors that determine the clinical longevity of a restoration is its surface characteristics, the restoration must provide a smooth and regular surface, but it is not always possible (1).as the composite resins are polymerbased materials, they may undergo degradation inside the oral environment, resulting in alterations of the mechanical properties (2).mechanical properties of composites are not only influenced by their chemical composition but also by the environment to which they are exposed (3). during the last decades, the increasing demand for esthetic dentistry have led to the development of resin composite materials for direct restorations with improved physical and mechanical properties, and clinically acceptable surface smoothness (4). to achieve the last goal, manufacturers predominantly have increased the filler load and reduced the diameter of the filler particles to produce composites with a good mix of polishability and strength (5). packable composites were expected to exhibit excellent mechanical and physical properties owing to their high filler load (6). (1) lecturer, department of conservative dentistry, college of dentistry, university of baghdad. where nanofill composites consist of individual nanosilica particles and nanoclusters, the nanocluster fillers are agglomerates of nanosized particles and act as a single unit to achieve higher filler loading and strength (7) however, the shrinkage of the methacrylate resin has remained a major challenge (8). different high-molecular weight matrix resin compositions have been developed with the aim of diminishing polymerization shrinkage. these include a cationic ring-opening hybrid monomer system that contains siloxane and oxirane structural moieties, this material commonly called siloranes (9). the surface roughness property of any material is the result of an interaction of multiple factors. some of them are intrinsic that are related to the material itself, such as the filler (type, shape, size and distribution of the particles), the type of resinous matrix as well as the ultimate degree of cure reached, and the efficiency at the filler/matrix interface. other factors are extrinsic that related to the type of polishing system used, drinks, foods and influence of the oral environments (10). mouth rinses are considered one of these affecting factors. mouth rinses are widely used to prevent and control caries and periodontal diseases, and are frequently used, even without professional prescription. these mouth rinses consists of water, antimicrobial agents, salts, and, j bagh college dentistry vol. 28(3), september 2016 effect of mouth rinses restorative dentistry 2 in some cases, alcohol (11). the variation in the concentration of these substances may increase sorption, solubility and surface degradation of resin composites (12). taking in consideration the importance of roughness with respect to esthetic and function of restorations, this in vitro study was conducted to analyze the effects of two types of mouth rinses (alcohol-containing and alcohol free fluoride containing) on the surface roughness of three esthetic restorative materials (nanofilledfiltek z350, packable filtek p60 and silorinefiltekp90). materials and methods specimens’preparation ninety specimens (shade a3) were constructed from three composite materials (30 from each). the three resin-based composite materials used in this study are shown in (table 1). a specially designed cylindrical plastic mold (12mm diameter and 2mm height) was used to prepare disc-shaped composite specimens (13). a celluloid strip (odus, produits dentaires sa ch-1800 vevey/switzerland)was placed on a flat glass slide (microglass industries, pahari dhiraj, delhi) on top of a white background, the mold was then placed on it and slightly overfilled in one increment with one of the composite materials and a second celluloid strip was then placed on top of the mold and overlaid with another glass slide with the application of 200gm load for 1 minute to extrude excess material and obtain a smooth surface(14). the top slide was then removed and the composite was light cured using a light emitted diode led curing light (latte ydl, china) with a light intensity 1000 m w/cm2, for 20 seconds of exposure time to top and bottom surfaces, respectively following the manufacturer’s instructions . the tip of curing light was placed as close as possible to the glass slide to achieve maximum curing depth. then all prepared samples were stored in distilled water at 37ºc for 24 hours using incubator, for rehydration and completion of the polymerization to mimic the first day of service in the oral environment(15). specimens’ grouping the specimens of each type of composite were randomly divided into three groups of ten specimens each as follows: group i distilled water (control), group ii listerine (alcohol-containing), group iii sensodyne pronamel (alcohol free fluoride-containing), the specimens were then immersed in 20 ml of respective treatment solution (table 2) and kept in an incubator at 37°c for 24 hours that was reported to be equivalent in time to 1 year of 4min daily use (16). all specimens were removed after 24 hours of their immersion in treatment solution and incubation. then 20 ml of distilled water (ph=7.53) was used to thoroughly rinse each specimens for 120s. each specimen was then blotted dry using a filter paper (17) the ph of treatment solution was recorded before and after immersion using a digital ph meter (microprocessor ph meter, hanna ph 213, italy). for each solution three readouts were taken and the mean ph values were: distilled water-ph: 7.31; listerine-ph: 4.22; synsodine pronamel-ph: 6.21. surface roughness measurements the specimens were then checked for post immersion surface roughness. the average values of surface roughness (ra-μ m) of all specimens were measured by means of a profilometer (handheld roughness tester, tr200, time group inc. china). the profilometer measured each specimen at three areas in various locations with a maximum travelling distance of 11 mm (0.5mm left from both periphery of the specimen). the average value was recorded as the mean ra of that specimen. the mean ra values were automatically calculated by the profilometer. statistical analyses all statistical analyses were carried out using spss statistical software (version19.0, spss, chicago, il, usa). after data collection, mean values and standard deviations were calculated for all groups and subgroups. one way analysis of variance (anova) test was performed among the experimental groups to determine where there any statically significant differences under various conditions. when a significant difference was found, least significant difference (lsd) test was done to find where the significance occurs. the mean difference is significant at the 0.05 level. j bagh college dentistry vol. 28(3), september 2016 effect of mouth rinses restorative dentistry 3 results the descriptive statistics (mean and standard deviation) of surface roughness (ra value in μm) of the different subgroups of filtek™ z350 xt, filtek™ p60 and filtek™ p90 composite resin materials and the comparison of significance of the different subgroups of each composite resin material byone-way anova test are presented in table 3.from this table, it can be seen that the mean ra values of all subgroups of filtek™ z350 xt composite resin material were higher than the mean ra values of their corresponding subgroups of filtek™ p60 and filtek™ p90 composite resin materials. also we can see that the mean ra values of filtek™ p60 is similar to the mean ra values of filtek™ p90 in distilled water but they differ after conditioning with the mouth rinses ,since the mean ra values of filtek ™ p90 is higher than of filtek™ p60. statistical analysis of data by using the analysis of variance "anova" among the three treatment solution against each type of composite materials revealed that there was a highly significant difference among the three treatment solution in all types of composites used (control, listerine, and synsodine pronamel) p<0.05 further investigation using lsd(least significant difference)test showed that there was a statistically high significant difference in surface roughness between the subgroups stored in both mouth rinses as compared with control subgroup(p=000), while there was statistically no differences between the subgroups stored in mouth rinses (listerine and synsodyne pronamel)(p>0.05) as shown in table 4. anova test was also done among the three tested composite materials against each treatment solution (table 5), it show that there is a highly significant differences among the three composite types in each treatment solution. further investigation using lsd (least significant difference) test was done to find where the significance occur (table 6)showed that there was a statistically high significant differences in surface roughness between all subgroups except for subgroup of p60 and subgroup of p90 in distilled water. table 1: types of composite resin materials used in this study table 2: types of mouth rinses used in study product composite type resin components filler type particle size filler loading wt(vol) manufacturer filtek z350 nanofilled bis-gma, udma, tegdma and bis-ema ,pegdma non-agglomerated /non aggregated silica filler nonagglomerated /non aggregated zirconia filler aggregated zirconia/silica cluster filler 20nm silica filler 4-11nm zirconia filler 0.6-10 μm 78.5% (63.3%) 3mdental product (usa) filtek p60 packable bisgma,udma and bis-ema zirconia/silica 0.01-3.5 μm (mean0.6 μm) 83% (61%) 3mdental product(usa) filtek p90 microhybrid silorane (or) ;3,4 epoxycyclohexyl ethylcyclopolymethyl siloxane, bis-3,4 epoxycyclohexy lethylphenylmethylsilan quartz, yttriumfluorid 0.1-o.2μm (mean 0.47μm) 76% (55%) 3mdental product (usa) treatment solutions composition manufacturer/ batch number listerine eucalyptol 0.092%, menthol 0.042%, menthyl salicylate 0.06, thymol 0.064, water, alcohol (ethanol) (21.6%), sorbitol, flavoring ,poloxamer 407,benzoic acid sodium saccharin, sodium benzoate, dand c yellow no. 10, fdand c green no. 3 johnson and johnson healthcare products, usa3481lz sensodyne pronamel water, glycerin, sorbitol, poloxamer 338, peg-60 hydrogenated castor oil, vp/va copolymer, potassium nitrate, sodium benzoate,cellulose gum, aroma, sodium xsazd, propylparaben, cetylpyridinium chloride, sodium saccharin, xanthan gum, disodium phosphate, sodium phosphate, ci 42090, contains sodium fluoride (450 ppm fluoride). glaxosmithkline germany 1188026 j bagh college dentistry vol. 28(3), september 2016 effect of mouth rinses restorative dentistry 4 table 3: descriptive statistics of surface roughness values in μm for all groupsand statistical analysis of data by (anova) among the three treatment solution against each type of composite materials distilled water listerine synsodyne pronamel f-test significance filtektm z350 xt mean (μm) 0.0071 0.011 0.012 53.894 0.000 (hs) sd 0.00122 0.000816 0.001563 filtektm p60 mean (μm) 0.00112 0.0073 0.00759 140.949 0.000 (hs) sd 0.000123 0.001567 0.00061 filtektm p90 mean (μm) 0.0012 0.0092 0.0097 513.000 0.000 (hs) sd 0.000231 0.000919 0.000949 table 4: lsd test between subgroups of the tested solution against each type of composite table 5:anovaand lsdtests among the three tested material against each treatment solution f-value significance z350 and p60 z350 and p90 p60and p90 distilled water 226.595 0.000(hs) 0.000(hs) 0.000(hs) 0.806(ns) listerine 25.891 0.000(hs) 0.000(hs) 0.002(hs) 0.001(hs) synsodinepronamel 39.271 0.000(hs) 0.000(hs) 0.000(hs) 0.000(hs) fig. 1: mean surface roughness values of all groups discussion the maintenance of a smooth surface is fundamental for improving the clinical longevity of aesthetic materials, whereas rough restorations can lead to periodontal problems or plaque retention, subsequent recurrent decay, surface staining and patient discomfort (18). bollen et al. (1997) related that some studies suggested a threshold surface roughness for bacterial retention (ra = 0.2 μm). an increase in surface roughness above this threshold roughness resulted in a simultaneous increase in plaque accumulation, thereby increasing the risk for both caries and periodontal inflammation (19). in this research the samples were not subjected to any surface treatment, in order to avoid the influence of finishing techniques on the results. only a polyester strip was used on the resin composite before polymerization with the intention of obtaining a smooth surface. any form of additional polishing could lead to an increase in surface roughness (20). gonçalves et al. (21) presented that, the smoothest resin surfaces were obtained after the photopolymerization of the composites through the polyester matrix strips. there are two variable present in this study, treatment solution (mouth rinses) and composite resins. effect of mouth rinse mouth rinses contain water, antimicrobial agents, salts, preservatives and in some cases materials control and listerine control and pronamel listerine and pronamel filtektm z350 xt 0.000(hs) 0.000(hs) 1.000(ns) filtektm p60 0.000(hs) 0.000(hs) 0.511(ns) filtektm p90 0.000(hs) 0.000(hs) 0.154(ns) j bagh college dentistry vol. 28(3), september 2016 effect of mouth rinses restorative dentistry 5 alcohol or fluoride, the variation in the concentration of these substances affects the ph of mouth rinses (20). it has been found that low-ph mouth rinses with higher alcohol content may affect some physical-mechanical properties of resin composites, producing softening of esthetic restorative materials(22). all types of mouth rinses contain solvent such as water or alcohol, and this solvent enter the polymer network through porosities and intermolecular spaces and cause expansion that can affect the dimensions of the restorations. in addition, solvent uptake is accompanied by a loss of unreacted components, like unreacted monomers, or ions from filler particles, results in a loss of mass. (2) listerine have low ph (4.2) because of containing benzoic acid with high alcohol percentage, alcohol is a good polymer chain solvent, and solutions with high alcohol concentration can degrade the mechanical properties and increase the wear of composite resins (23), filler tend to fall out from resin material and the matrix component decomposes when exposed to low ph environment (24). although, the ph of synsodine pronamel mouth rinses(6.2) is lower than that of listerine (4.2) but there was no significant difference between them, this may be due to that sodium fluoride is as an active ingredient(450ppm)in synsodine pronamel which may cause surface degradation. fluoride agents with a low ph and a high fluoride concentration has been shown to cause surface damage to dental composites by dissolution and loss of filler particles, this may result in increased surface area exposure of the resin matrix (25), alsofluoride cause disorganization of the siloxane network formed from the condensation of intramolecular silanol groups, which stabilizes the interface. this may weaken the particle-matrix interface (26). according to the results of this study, both mouth rinses irrespective of the presence or absence of alcohol resulted in significant increase in the surface roughness of the tested resin composite materials compared to control with no significant difference between them.it was found that alcohol is not the only factor that has a softening effect on the restorative materials. other ingredients in mouth rinses such as solvents, fluoride and acids may have softening effect on polymer matrix (27).the finding of the present study is agreed with the result of jyothi et al. (23)who reported that degradation of the composite resins are not significantly affected by the type of the mouth rinses used. effect of composite resin type in this study; two dimethacrylates based composite resins, filtek™ z350 xt and filtek™ p60 were compared with a silorane-based, filtek™ p90 low shrink posterior composite. the two methacrylate based composite types tested in this study had the same polymer matrix composition: bis-gma, udma, and bis-ema resins. except for bis-ema, which is an ethoxylated version of bis-gma, other molecules (bis-gma, udma, and pegdma) have hydroxyl groups which promote water sorption. moreover, the incorporation of tegdma in filtek™ z350 xt composite material resulted in an increase in water uptake as this monomer presents higher hydrophilicity when compared with bis-gma and udma (28);so the lowest surface roughness of then a nofilled composites, filtek™ z350 xt, could be explained be the presence of tegdma and the (size, shape, and amount of)filler particles present in the compositions of the materials (table 1). the composition and size of the filler particles affect the surface smoothness .the surface roughness increased as the filler sizes will be increased (29).therefore, it can be expected that nanocomposite with a smaller particle size, will have a smoother surface. however, in the present study, the nanofilled composite resin type (filtektm z350) showed lowest roughness values. this could be due to the nature of the resin matrix and the possible porosity in aggregated filler particles (30). filtektm z350contains comparatively small nanoclusters, producing a greater surface area to volume ratio and hence a larger area of hydrophilic silane available for water sorption. consequently, the physicochemical properties of the intermediate phase will become more critical since a higher degree of silanisation will be required for resin-based composite with a high volume percentage of nanoparticles (31). filtektm z350 xt might absorb more water at the filler–matrix interface. the absorbed water causes filler–matrix debonding or hydrolytic degradation of the filler (30). the nanofillers are discreetly dispersed or organized in clusters; these purely inorganic clusters are formed by individual primary nanoparticles bonded between them by weak intermolecular forces (32). these findings are in accordance with previous studies concluding that then a nofilled composites have the lowest surface roughnessas compared with these two filling materials (33-35). the result of the present study shows that silorane based resin composite and packable resin exhibited similar surface roughness in distilled water but there is highly significant difference j bagh college dentistry vol. 28(3), september 2016 effect of mouth rinses restorative dentistry 6 between them after conditioning in both mouth rinses, since the mean ra values of filtek ™ p90 is higher than of filtek™ p60. siloranes are silicon-based monomers with oxirane (epoxide) functionality. siloirnes can be extrely hydrophobic, making the oxirane groups inaccessible to attack by water or water-soluble species (36), therefore decreasing solvent sorption (28). however; there is a significant increase in surface roughness of silorane –based resin after immersion, this can be contributed to the filler load and composition. the silorane-based resin composites presents filer particles of fine quartz particles and radiopaque yttrium fluoride, which make up 76% of its weight and which have an average size of 0.47μm and is classified as a microhybrid resin composite, this lower amount of filler particles as compared with filtek™ p60 may have contributed to its ability to obtain higher surface roughness values than packable composite (37). han et al. (38) suggest that a relatively higher filler loading increase the stability of resin composite surface against low ph condition. the presence of fillers in a polymer network can greatly affect solvent uptake and dissolution. studies indicated that composites containing radiopaque glasses, such as ba glass, sr, yb and la have been shown to undergo greater dissolution than silica and quartz containing resin composites (2,39).garced et al. found that the highest values of ytterbium fluoride release were observed in the ph-cycling as compared to the deionized water medium (40). this may explain the significant increase in roughness in filtektm p90 after immersion where ytterbiumtrifluoride are part of their filler content. ytterbium trifluoride, which contributes to fluoride release, is a water soluble component and leaches out after immersion in a solution (30). this might alter the microstructure of the composite bulk through the formation of pores (28). these findings are in agreement with results of other studies (41,42),that show the mouth rinses increase the surface roughness of silorane-based composite. filtek™ p60 has the higher filler loads with silica fillers type which has the lower dissolution as compared with other filler types but still there is a significant increase in surface roughness after immersion in mouth rinses this may contributed to the presence bis-gma and udma hydroxyl groups which promote water sorption. this in vitro study appears to show that mouth rinses utilization can significantly increase composite roughness but the average surface roughness of the tested materials in all circumstances didn't exceed the critical threshold value of 0.2μm, which allows plaque accumulation. the results of the present study allow us to conclude that the changes observed in the composites depended on the material itself rather than the mouth rinse solution used. references 1. rocha ac, lima cs, santos mc, montes ma. evaluation of surface roughness of a nanofill resin composite after simulated brushing and immersion in mouthrinses, alcohol and water. j mat res 2010; 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2: 7. 38. han l, okamoto a, fukushima m, okiji t.evaluation of flowable composite resin surfaces eroded by acidic and alcoholic drinks. dent mater 2008; 27(3): 455-65. 39. asaka y, miyazaki m, aboshi h, yoshida t, takamizawa t, kurokawa h, rikuta a. edx fluorescence analysis and sem observations of resin composites. jos 2004; 46(3): 143-8. 40. garcez rm, buzalaf ma, araujo pa. fluoride release of six restorative materials in water and phcycling solutions. j appl. oral sci2007; 15(5):406-11. 41. ozer s, tunc e s, tuloglu n, bayrak s. solubility of two resins composite in different mouthrinses. biomed research international 2014:1-4. 42. fernandez r a, el araby m, siblini m, al-shehri a.the effect of different types of oral mouth rinses on the hardnes of silorane based and nano-hybrid composites. j sudi oral sci 2014; 1:105-9. dropbox 12 abeer 66-70.pdf simplify your life saif f.doc j bagh college dentistry vol. 25(4), december 2013 local drug delivery oral and maxillofacial surgery and periodontics 79 local drug delivery systems for treating periodontal diseases (a review of literature) adnan k. taresh, b.d.s. (1) saif sehamm saliem juma, b.d.s., m.sc. (2) abstract in this review of literature, the light will be concentrated on the local drugs delivery systems for treating the periodontal diseases. principles, types, advantages and indications of each type will be discussed in this paper. (j bagh coll dentistry 2013; 25(4):79-85). introduction the inflammatory periodontal diseases are widely accepted as being caused by bacteria associated with dental plaque. however, the nature of the periodontal disease resulting from dental plaque appears to depend to a large extent on the interaction among the bacterial agent, the environment, and the response of the host's defense mechanisms to the bacterial assault. periodontal disease therapy has been directed at altering the periodontal environment to one which is less conducive to the retention of bacterial plaque in the vicinity of the gingival tissues, in particular, the marginal attachment apparatus. classic therapeutic regimes to achieve this aim would include some or all of the following procedures: 1. instruction in oral hygiene techniques to achieve an adequate level of oral cleanliness, 2. scaling, correction of inadequate restorative dentistry, root planing, and the surgical elimination of pockets or other anatomical defects which aid bacterial retention and interfere with plaque removal. local delivery of chemotherapeutic agents into the pockets via a syringe or irrigating device has been shown to have an effect on the subgingival flora, but, clinically, it has not been effective in halting the progression of periodontal attachment loss (1,2) .the lack of clinical efficacy is probably because of the short time the irrigating solution remains in contact with the pocket environment (3). the recent development of sophisticated, subgingivally placed delivery systems has provided the possibility of maintaining effective, intrapocket, levels of antibacterial agents for extended periods of time. these systems have provided the profession with a new tool which, in clinical trials, has been shown to alter the subgingival flora and influence the healing of the marginal attachment apparatus. (1)diploma student. department of periodontics. college of dentistry. university of baghdad. (2)assistant professor. department of periodontics. college of dentistry. university of baghdad. principle of local intrapocket delivery of antibacterial drugs 1. the periodontal pocket provides a natural reservoir bathed by gingival crevicular fluid which is easily accessible for the insertion of a delivery device. 2. the gingival crevicular fluid provides a leaching medium for the release of a drug from the solid dosage form and for its distribution throughout the pocket. 3. these features, together with the fact that the periodontal diseases are localized to the immediate environment of the pocket, make the periodontal pocket a natural site for treatment with local sustained-release delivery systems. the goal in using an intrapocket device for the delivery of an antibacterial agent is the achievement and maintenance of therapeutic levels of the drug for the required period of time. drug delivery systems for treating periodontitis various drug delivery system for treating periodontitis as fibers, film, injectable systems, gels, strips and compacts, vesicular systems etc. (4) fibers fibers, or thread-like devices, are reservoirtype systems, placed circumferentially into the pockets with an applicator and secured with cyanoacrylate adhesive for the sustained release of then trapped drug into the periodontal pocket. the release of the tetracycline from the cellulose acetate fibres as occurred by diffusion mechanism is rapid with approximately 95% of the drug released in the first two hours and, therefore, a single application of these fibres does not provide an effective drug concentration for long periods. compared with the less effective tetracycline delivery from hollow fibres, fibres containing 20% (v/v) chlorhexidine, when placed into periodontal pockets, exhibited a prompt and marked reduction in signs and symptoms of periodontal disease. fibers are used for the j bagh college dentistry vol. 25(4), december 2013 local drug delivery oral and maxillofacial surgery and periodontics 80 treatment of periodontitisahollow fiber and b monolithic. in spite of the fact that the hollow fibres served as a good drug holding device, they permitted rapid evacuation of the drug. to retard drug release, drug-impregnated monolithic fibres were developed by adding drug to molten polymers, spinning at high temperature and subsequent cooling (5) . several polymers such as poly (ecaprolactone) (pcl), polyurethane, polypropylene, cellulose acetate propionate and ethyl vinyl acetate (eva) have been investigated as matrices for the delivery of drug to the periodontal pocket. in this respect, monolithic (eva) fibres were found to be effective in controlling the release of encapsulated drug, and the same has been demonstrated by several in vitro and in vivo studies. (6) reported that eva fibres containing 25% tetracycline hydrochloride maintained a constant drug level in the gcf above 600 mg/ml throughout ten days, showing zero-order release characteristics of eva fibres . tetracycline fibre treatment adjunctive to srp showed significantly less periodontal disease recurrence (4%) compared with srp alone (9%), tetracycline fibre alone for 10 days (10%) and tetracycline fibre alone for 20 days (12%). studies that were wellconducted and well-controlled have demonstrated the clinical efficacy of these fibres but their actual value in patient therapy has been somewhat difficult to interpret because clinicians have found the fibre placement technique challenging include. 1patients experienced discomfort during fibre placement and at fibre removal 2various degrees of gingival redness were observed. 3the complication of winding a fibre into place, 4the need to retain the device within the pocket and then the removal of it after seven to ten days may limit its wide acceptance by patients and periodontists. films a far more widely used form of intra-pocket delivery device has been in the shape of film, prepared either by solvent casting or direct milling. bigger films either could be applied within the cavity onto the cheek mucosa or gingival surface or could be cut or punched into appropriate sizes so as to be inserted into the site of action. films are matrix delivery systems in which drugs are distributed throughout the polymer and release occurs by drug diffusion and/or matrix dissolution or erosion. films of various polymers have been made for the controlled release of therapeutic agents. sustained release devices composed of cross-linked fish gelatin (bycoprotein) containing chlorhexidine diacetate or chlorhexidine hydrochloride have been developed by steinberg .in vitro release profile of chlorhexidine from such degradable films is dependent on the amount of chlorhexidine incorporated into the film, by the cross-link density of the polymer and by the chlorhexidine salt used. the time of total drug release is short and varies from 4 to 80 h. films based on synthetic biodegradable polymers such as poly (lactide-co-glycolide) (plga) containing tetracycline have been developed for modulatedrelease of drug in the periodontal pocket as slab like device. in vitro release study showed that insoluble films release drug by diffusion and soluble release drug by dissolution of the carrier. the advantages of such a device include 1ease of insertion. 2dimensions that confirms well with the dimensions of the pocket. 3minimum pain on insertion (7). non-biodegradable ethyl cellulose based films for the delivery of chlorhexidine diacetate; metronidazole, tetracycline and minocycline have been developed by solvent evaporation method and clinically tested. ethyl cellulose films showed sustained drug release and release rates were dependent on the casting solvent and drug load. the use of chloroform as the casting solvent significantly retarded the release rate of the drug compared to ethanol as the casting solvent. the incorporation of polyethylene glycol in the films, however, enhanced the release rate of the drugs. published clinical findings also confirmed that the treatment with drug-loaded ethyl cellulose films produced significantly greater improvements in the incidence of bleeding on probing, probing depths and attachment levels when compared to the conventional maintenance treatment. in contrast to the non-degradable systems discussed above, the films made up of degradable polymers erode or dissolve in the gingival crevice so that removal after treatment is not required. natural and synthetic biopolymers play a pivotal part in drug delivery to periodontal pocket. more recently, a film composed of cross-linked hydrolysed gelatin and glycerine for local delivery of chlorhexidine digluconate has been developed and commercialised under the tradename periochip. the system showed an initial burst effect, whereby 40% of chlorhexidine was released in the first 24 hours, followed by a constant slower release over about seven days. this film has the advantage over other j bagh college dentistry vol. 25(4), december 2013 local drug delivery oral and maxillofacial surgery and periodontics 81 biodegradable films in which it remains inside the pocket with no additional aids for retention because of the adhesive nature of the periochip components. synthetic biodegradable polymers have also been evaluated for sustained release of drug in the periodontal pocket. the combination of amoxycillin and metronidazole in the carrier polymer plga showed not only an extended spectrum of antimicrobial activity but also a synergistic effect against e. limosum, which had been reported to be resistant to metronidazole in earlier studies. the films showed a sustained in vitro release for a period of 16 days and the in vivo drug concentrations were maintained above the mic value for the entire period of the release studies. by contrast, plga films containing tetracycline hydrochloride showed poor retention in the periodontal pockets with incomplete release of tetracycline. this effect could be attributed to the hydrophobic nature of plga matrix and the difference in physicochemical properties of the drugs. injectable system injectable systems are particularly attractive for the delivery of antibiotic agents into the periodontal pocket. the application can be easily and rapidly carried out, without pain, by using a syringe. thus, the cost of the therapy is considerably reduced compared to devices that need time to be placed and secured. moreover, an injectable delivery system should be able to fill the pocket, thus reaching a large proportion of pathogens. these systems allow easy application of therapeutic agent using a syringe. they are also cost saving. gels mucoadhesive, metronidazole containing gel systems based on hydroxyethyl cellulose, corbopol 974, and polycarbophil have been made. gel is applied sublingually with the help of blunt cannula and syringe. the gel is only marginally affective in decreasing the anaerobic bacterial count. this may be due to low number of bacteria susceptible to metronidazole or due to presence of bacterial biofilms. locally applied controlled release doxycycline gel may partly counteract the negative effect of smoking on periodontal healing following no surgical therapy(8) the first was tetracycline base loaded into the microtubular excepient halloysite, which was coated with chitosan to further retard drug release. the syringeability of this formulation at various temperatures was evaluated to ensure ease of delivery to periodontal pocket. a stability study was performed to examine change in thermoresponsivity over time (9) in addition, lidocaine release from gels was evaluated using a release apparatus stimulating buccal condition .the results indicated that an increase in carbopol concentration significantly increased gel compressibility, hardness and adhesiveness factors that affect ease of gel removal from container, ease of gel application onto mucosal membrane, and gel bioadhesion . characterization of tetracycline containing bioadhesive polymer network designed for the treatment of periodontal disease and result shows that effect of increasing drug concentrations on the rheological and textural properties was dependent on pvp(polyvinylpyrrolidone) concentration. locally applied controlled release dox gel may partly counteract the negative effect of smoking on periodontal healing. the safety profile, longerterm retention, antimicrobial activity suggests that tetracycline containing copolymer gels represents a safe and effective bioerodible therapy for periodontitis. growing interest in developing absorbable pharmaceutical surgical products that degrade in biologic environment to safe by products and leaves the residual mass at application site justified the search fir novel absorbable gels. comparative analysis of tetracycline containing dental gels: poloxamer and monoglyceride based formulations have been done which shows that poloxamer and monoglyceride gels, when applied subgingivally, produce a significant improved outcome in moderate to deep periodontal pockets(10). injectable gels together with the solid devices, semisolid formulations also receive reasonable attention for the localized delivery of antibiotics. semisolid or gel formulations can indeed have some advantages. in spite of the relatively faster release of the incorporated drug, gels can be more easily prepared and administered. moreover, they possess a higher biocompatibility and bioadhesivity, allowing adhesion to the mucosa in the dental pocket and, finally, they can be rapidly eliminated through normal catabolic pathways, decreasing the risk of irritative or allergic host reactions at the application site. various oleogels and hydrogels for the delivery of tetracycline (2.5%), metronidazole (25%), metronidazole benzoate (40%), as well as a combination of tetracycline (2.5%) and metronidazole benzoate (40%), have been tested and satisfactory results have been achieved. the gels composed of cellulose derivatives such as hydroxypropylmethyl cellulose and hydroxyethyl j bagh college dentistry vol. 25(4), december 2013 local drug delivery oral and maxillofacial surgery and periodontics 82 cellulose do not appear to have sustained release properties. surprisingly, despite the rapid drug release and poor retention of these gels, positive clinical results in moderate to deep periodontitis were obtained. bioadhesion or mucoadhesion is a preliminary requirement for prolonged release of the drug at the site (11). the retention time, as determined by fluorescein release, was found to be significantly higher for chitosan gel as compared to xanthan gum and poly(ethylene oxide) gel. chitosan, a novel biodegradable natural polymer, in a gel form (1%, w/w) with or without 15% metronidazole, had demonstrated effectiveness in the treatment of chronic periodontitis. bioadhesive semisolid, polymeric system can be utilised as an important intra-pocket delivery vehicle because it can easily pass through a cannula into a periodontal pocket where it solidifies in situ to deliver the therapeutic agent for a prolonged period. these systems exhibit a pseudoplastic flow and thermoresponsive behaviour, existing as a liquid at room temperature and gel at 34–37 8c. tetracyclineloaded bioadhesive semisolid, polymeric system based upon hydroxyethyl celluloseand polyvinylpyrrolidoneand metronidazole-loaded systems based upon carbopol 974p, hydroxyethyl cellulose and polycarbophil are reported. another such system composed of poloxamer 407 and carbopol 934p and containing propolis extract were designed for the treatment of periodontal disease. the release of the propolis was controlled by the relaxation of polymer chains and the greatest mucoadhesion was noted for the formulation containing 60:1 ratio of poloxamer 407:carbopol 934p. another injectable biodegradable gel based on poly(dl-lactide) dissolved in a biocompatible solvent n-methyl-2pyrrolidone (nmp) (atrigel1) was widely studied . the atrigel1 loaded with 10% doxycycline hyclate showed high levels of doxycycline (250 mg/ml) in the gcf for a period of seven days. interestingly, levels of 10–20 mg/ml were still present for three to five days after the polymer had been removed. it is possibly because of minute particles of polymer remaining within the pockets or because of the substantive effects of tetracyclines within the periodontal pocketadjacent-tooth-surface environment. in another study, atrigel1 containing 5% sanguinarine was found to be superior to the control in the treatment of adult periodontitis and the findings have been recently confirmed in a human clinical trial. the semisolid system based on water-free mixtures of lipids, such as glycerol monooleate (monoglyceride) and sesame oil (triglyceride), is characterised by a solid–gel transition and become semisolid on contact with gingival fluid in the periodontal pocket. the system is based on the ability of glycerides to form liquid crystals, that is, reverse hexagonals on contact with water. the reverse hexagonal form has more favourable sustained release properties, compared with the initial cubic form. the matrix is degraded by neutrophils and bacterial lipase in the gcf. biodegradable gels are other useful prospects for the delivery of therapeutic agents into periodontal pockets. bioerodible lactic– glycolic acid gels were found to be safe and tetracycline levels observed at days 3 and 8 probably represent significant antimicrobial efficacy. strips and compacts strips are thin and elongated matrix bands in which drugs are distributed throughout the polymer. generally, strips are made up of flexible polymers having a position securing mechanism, and accommodate a wide range of interproximal spacing .acrylic strips have been fabricated using a mixture of polymers, monomers and different concentrations of anti microbial agents. strips were fabricated either by solvent casting or pressure melt method. strips containing tetracycline, metronidazole or chlorhexidine demonstrated a decrease in number of motile rods, notably spirochetes. in a later development, the evaluation of amoxycillin-clavulainic acid loaded acrylic strips is reported. highest level of antibacterial agent was released during the first 24 hours period followed by release of therapeutic level of drugs for a subsequent 9 days period. effect persisted even after 3 week of removal of acrylic strips. tissue adhesive implants were made using n-butyl-2-cyanoacrylate as a drug trapping material and slowly release drug when used in the structure of a biodegradable local drug delivery device (12). ornidazole dental implants containing ethyl cellulose, hydroxy propyl cellulose, hydroxy propyl methyl cellulose and dibutyl phthalate by solvent casting technique result showed that drug release was initially high on day one to achieve immediate therapeutic level of drug in pocket, followed by marked fall in release by day two(13) chlorhexidine slow release devise has been made and it is antibacterial effect has been evaluated by agar diffusion test. vesicular systems vesicular liposomal systems are designed to mimic the bio-membranes in terms of structure and bio-behaviour, and hence are investigated intensively for targeting periodontal biofilms. jones and kaszuba reported interactions between j bagh college dentistry vol. 25(4), december 2013 local drug delivery oral and maxillofacial surgery and periodontics 83 liposomes made up of phosphatidylinositol (pi) and bacterial biofilms. the targeting of liposomes was thought to be because of the interaction of the polyhydroxy groups of liposomes with surface polymers of the bacterial glycol-calyx. succinylated concanavalin-a (lectin)-bearing liposomes (proteoliposomes) have been found to be effective for the delivery of triclosan to periodontal biofilms. in vitro and in vivo studies have revealed that, even after a very short exposure, the proteoliposomes are retained by the bacteria eventually delivering triclosan into the cellular interiors. the potential of lectin-bearing liposome systems as a targeting system for the control of gingivitis and dental plaque has been extensively studied by vyas et al. (14). the delivery of triclosan and chlorhexidine was studied for several liposomal compositions involving cationic as well as anionic lipids (15) robinson and co-workers reported further on the affinity and specificity of immunoliposomes to reduce dental plaque. the anti-oralis immunoliposomes showed the greatest affinity for s. oralis and affinity was unaffected by net charge on the lipid bilayer or by the number of antibodies conjugated to the liposomal surface. microparticle system microparticles based system of biodegradable poly alpha hydroxy acids such as poly lactide (pla) or poly (lactide – co-glycolide) plga containing tetracycline has been designed for periodontal disease therapy. plga microspheres containing minocycline have been formulated and have been used for the elimination of porphyromonas gingivalis from the periodontal pocket. microparticles of poly (dl-lactic-coglycolic acid) (plga) containing chlorhexidine free base, chlorhexidine di gluconate and their association or inclusion complex with methylatedbeta-cyclodextrin (hpbcd) were prepared with single emulsion, solvent evaporation technique(16) non-biodegradable as well as biodegradable materials have beeninvestigated for the preparation of microspheres. these materials include the polymers of natural origin, modified natural substances and synthetic polymers. they could preferably be formulated as a chip or could be part of a dental paste formulation, or otherwise be directly injected into the periodontal cavity. tetracycline-containing microcapsules in pluronic f127were reported to formgel at body temperature and hold the microcapsules in the periodontal pocket for the duration of treatment. plga microcapsules and microspheres have been proposed for the delivery of tetracycline and histatins. these microparticulate systems provide stability to the encapsulated drug. the in vitro drug release from such systems depends upon the polymer (lactide: glycolide) ratio, molecular weight, crystallinity and ph of the medium. some questions, however, related to the retention of such formulations in the periodontal pocket need clarification. nanoparticulate system modern drug delivery systems are designed for targeted controlled slow drug release. nanomaterials are of interest from a fundamental point of view because the properties of a material (e.g. melting point, electronic properties, optical properties) change when the size of the particles that make up the material becomes nanoscopic. with new properties, come new opportunities for technological and commercial development and applications of nanoparticles have been demonstrated or proposed in areas as diverse as microelectronics, coatings and paints, and biotechnology (17). from these applications has come the development of nanopharmaceuticals, nanosensors, nanoswitches, and nanodelivery systems. each of these has considerable significance in the field of local, or targeted, drug delivery. up to now polymer or microparticlebased hydrogels have been applied in dentistry, which can affect the rate of release because of their structure. recently, intensive research is being performed all over the world to improve the effectiveness of delivery systems. the nanoparticulate system provides several advantages as compared with microspheres, microparticles and emulsion-based delivery systems, including high dispersibility in an aqueous medium, controlled release rate and increased stability. nanoparticles, owing to their small size, penetrate regions that may be inaccessible to other delivery systems, such as the periodontal pocket areas below the gingival line(5) these systems reduce the frequency of administration and further provide a uniform distribution of the active agent over an extended period of time. biocompatible nanoparticles composed of 2-hydroxyethyl methacrylate (hema) and polyethyleneglycol dimethacrylate (pegdma) could be used as a drug delivery system for dental applications. the polymer-based nanoparticles were prepared via micellar polymerisation, which resulted in a well dispersible white powder material with particle size in the range of 50–180 nm. these nanoparticles are suitable for incorporation into a hydrogel matrix and to design new drug delivery devices for dental applications. moulari investigated the in vitro bactericidal activity of the j bagh college dentistry vol. 25(4), december 2013 local drug delivery oral and maxillofacial surgery and periodontics 84 harungana madagascariensis leaf extract (hle) on the oral bacterial strains largely implicated in dental caries and gingivitis infections. hleloaded plga nanoparticles were prepared using interfacial polymer deposition following the solvent diffusion method. incorporation of the hle into a colloidal carrier improved its antibacterial performance and diminution of the bactericidal concentration was observed. shefer and shefer patented a controlled release system useful for site-specific delivery of biologically active ingredients over an extended period of time. this system is a multi-component release system comprising biodegradable nanoparticles having bioadhesive properties encapsulated within a moisture sensitive microparticle. the bioadhesive properties of the nanoparticles are attributed to the positively charged surfactant entrapped on the particle surface. the multicomponent release system can be incorporated into any suitable oral hygiene product including gels, chewing gums, toothpaste and mouthwash for the treatment and prevention of periodontal disease. antisense oligonucleotideloaded chitosan-tripolyphosphate (tpp) nanoparticles were prepared and evaluated. chitosan/oligonucleotide-tpp nanoparticles, which were prepared by adding tpp after the formation of chitosan/oligonucleotide complex, showed the sustained release of oligonucleotides and are suitable for the local therapeutic application in periodontal diseases(18). in an attempt to obtain a novel delivery system adequate for the treatment of periodontal disease, triclosan-loaded polymeric (plga, pla and cellulose acetate phthalate) nanoparticles were prepared by emulsification–diffusion process. a preliminary in vivo study in dogs with induced periodontal defects suggested that triclosanloaded nanoparticles penetrate through the junctional epithelium (19). the nanoparticles were prepared using poly(d,l-lactide-coglycolide), poly(d,l-lactide) and cellulose acetate phthalate. poly (vinyl alcohol) was used as stabilizer. batches were prepared with different amounts of triclosan in order to evaluate the influence of the drug on nanoparticle properties. solid nanoparticles of less than 500 nm in diameter were obtained. these triclosan nanoparticles behave as a homogeneous polymer matrix-type delivery system, with the drug (triclosan) molecularly dispersed. release kinetics indicates that the depletion zone moves to the center of the device as the drug is released. this behavior suggests that the diffusion is the controlling factor of the release. a preliminary in vivo study using these nanoparticles has been performed in dogs with only the gingival index (gi) and bleeding on probing (bleeding on probing) being determined (19). with respect to the gingival index (gi), at days 1 and 8, it was found that a severe inflammation was detected in control and experimental sites (gi ¼ 3). it was concluded that triclosan nanoparticles were able to effect a reduction of the inflammation of the experimental sites. nano drug delivery carriers periodontal future aspects various nano materials that can be used are liposomes. their exterior lipid bilayer is very chemically reactive, thereby providing a means to conveniently couple “tags” on a covalent basis. such “tags” can be antibodies, antigens, cell receptors, nucleic acid probes, etc. this provides significant versatility in assay formats (i.e., immunoassay, receptorbased, nucleic acid probe, etc.) possible. with diameters ranging in size from approximately 50 nm to 800 nm, their aqueous core encapsulates up to millions of molecules of signal generating “markers” that can be detected in a variety of different way. a variety of different encapsulants are possible including visually detectable dyes (since the lipid bilayer is transparent), optically and fluorometrically detectable dyes, enzymes, and electroactive compounds. c60 c60 are spherical molecules about 1nm in diameter, comprising 60 carbon atoms arranged as 20 hexagons and 12 pentagons: the configuration of a football. hence they find application as nano pharmaceuticals with large drug payload in their cage like structure. on the other hand with development of various chemical substitutes for c60, it is possible to develop functionalized c60 with better drug targeting properties carbon nanotubes are adept at entering the nuclei of cells and may one day be used to deliver drugs and vaccines. the modified nanotubes have so far only been used to ferry a small peptide into the nuclei of fibroblast cells. (20) developed injectable periodontal drug delivery systems and showed that erythromycin had increased adsorption by nano ha microspheres in periodontal infected site (19) produced triclosan-loaded nanoparticles by the emulsification diffusion process, in an attempt to deliver drugs for the treatment of periodontal disease. the nanoparticles were prepared using poly (d,llactide-coglycolide), poly(d,l-lactide) and cellulose acetate phthalate. poly (vinyl alcohol) was used as stabilizer.it was found that triclosan was released in controlled j bagh college dentistry vol. 25(4), december 2013 local drug delivery oral and maxillofacial surgery and periodontics 85 manner in specific sites and found to be quite effective miscellaneous: low-dose antibiotic recently, there has been interest in the use of low-dose antibiotics. the dose is so low that the drug does not act to kill bacteria, but rather to change the way the body responds to infection. production of the enzyme collagenase is essential because older gingival tissues are replaced with new tissues. in periodontal disease there is an overproduction of collagenase, causing the destruction of healthy gum tissue. an interesting effect of low-dose antibiotics is that they not only kill the bacteria that may cause periodontal disease but also reduce the body’s production of collagenase, an enzyme that destroys gingival tissues. the antibiotic doxycycline was found to combat these enzymes, even in doses so small that there was no antibiotic effect. the advantages of smaller doses are that there is a great reduction in the chances of formation of resistant bacterial strains and side effects. periostat is a capsule of 20 mg of doxycycline, and clinical studies have shown that patients who take two capsules daily have a reduction in clinical inflammation. the daily 40-mg dose is so low as not to qualify as an antibiotic, and there is no known effect on the pocket bacteria. thus, periostat must be used in conjunction with other therapies that address bacterial removal (5) as conclusions; eradication of microorganisms from the periodontal pocket is the most important step in treating periodontitis. the limitations of mouth rinsing and irrigation have prompted research for the development of alternative delivery system. recently, advances in delivery technology have resulted in the controlled release of drugs. the requirements for treating periodontal disease include a means for targeting an anti-infective agent to infection sites and sustaining its localized concentration at effective levels for a sufficient time while concurrently evoking minimal or no side effects. this research has discussed local drug delivery devices used in treating periodontitis. from that following conclusions can be made: local drug delivery system is used effectively in controlling tissue associated bacteria, it eradicates the periodontal pathogens for several weeks. references 1. greenstein g. effects of subgingival irrigation on periodontal status. j periodontol 1987; 58: 827-36. 2. greenstein g. the role of metronidazole in the treatment of periodontal diseases. j periodontol 1993; 64(1):1-15. 3. soskolne wa, heasman pa, stabholz a, smart gj, palmer m, flashner m, et al. sustained local delivery of chlorhexidine in the treatment of periodontitis: a multicenter study. j periodontol 1997; 68: 32-8. 4. jain n, gaurav k, javed s, iqbal z, talegaokar s. ahmad fj, khar rk. recent approaches for the treatment of periodontitis. drug discov today 2008; 1 (21-22): 932-43. 5. goodson jm et al. monolithic tetracycline-containing fibres for controlled delivery to periodontal pockets. j. periodontol 1983; 54: 575–9. 6. tonetti ms, piniprato g, corelli p. principles and clinical application of periodontal controlled drug delivery with tetracycline fibers. int j periodontics and restorative dent 1994; 14(5): 42135. 7. vyas sp, sihorkar v, mishra v. controlled and targeted drug delivery strategies towards intraperiodontal pocket disease. j clin pharm ther 2000; 25 (1): 21-42. 8. tomasi c, jan lw. locally delivered doxycycline improves the healing following non-surgical periodontal therapy in smokers. j clin periodontol 2004; 31: 589-95. 9. kelly hm, deasy pb, ziaka e, cleffey n. formulation and preliminary in vivo dog studies of a novel drug delivery for the treatment of periodontitis. int. j. pharm. 2004; 15(1): 167-83. 10. esposito e, carrota v, scabbia a, trombelli l, antena pd, menegatti e. comparative analysis of tetracycline containing dental gels: poloxamer and monoglyceride based formulations. int j pharm 1996; 142: 9-23. 11. jones sd, woolfson da, brown fa, michael j, neill o. mucoadhesive, syringeable drug delivery systems for controlled application of metronidazole to periodontal pocket. in vitro release kinetics, syringeability, mechanical and mucoadhesive properties j contr rel 2002; 49(1): 71-9. 12. eskanderi mm, ozturk og, eskandari hg, balli e, yilmaz c. cyanoacrylate adhesive provides efficient local drug delivery. clin orthop releat res 2006; 12: 45-55. 13. mastiholimath vs, dandagi pm, gadad ap, patil mb, manvi fv. formulation and evaluation of ornidazole dental implants for periodontitis. indian j pham sci 2006; 68(1): 68-71. 14. vyas sp, et al. preparation, characterization and in vitro antimicrobial activity of metronidazole bearing lectinized liposomes for intra-periodontal pocket delivery. pharmazie 2001; 56: 554–60. 15. jones mn, et al. the interaction of phospholipid liposomes with bacteria and their use in the delivery of bactericides. j drug target 1997; 5: 25–34. 16. yoe ic, poff j, cortes me, simisterra rd, faris cb, hildgen p, langer r, shastri vp. a novel polymeric chlorhexidine device for treatment of periodontal disease. biomaterials 2004; 25(17): 3743-50. 17. kohli p, martin c. smart nanotubes for biomedical and biotechnological applications. drug news perspect 2003; 16: 566-73. 18. dung th, et al. chitosan -tpp nanoparticle as a release system of antisense oligonucleotide in the oral environment. j nanosci nanotechnol 2007; 7: 3695-9. 19. pinon-segundo e, ganem-quintanar a, alonso-perez v, quintanar-guerrero d. preparation and characterization of triclosan nanoparticles for periodontal treatment. int j pharm 2005; 294: 217-32. 20. pataquiva mateus ay, ferraz mp, monteiro fj. nano hydroxyapatite microspheres for periodontitis treatment: preparation and cytotoxicity studies. eur cells mater 2007; 14(suppl 1): 85. j bagh college dentistry vol. 26(1), march 2014 assessment of oral and maxillofacial surgery and periodontics 144 assessment of some salivary biochemical parameters in cigarette smokers with chronic periodontitis yadgar gazy, b.d.s., m.sc. (1) bakhtiar mohiadeen,(2) ziwar al-kasab, ph.d. (3) abstract background: cigarette smoking is an important risk factor that has a clear strong association with the prevalence and severity of chronic periodontitis (cp). salivary biochemical parameters may be affected by both smoking and cp together. materials and methods: eighty systematically healthy male patients were included in this study. they were grouped based on their periodontal and smoking status. unstimulated whole saliva (uws) was collected from all subject. salivary flow rate (fr) was measured during sample collection. parameters such as salivary ph, total protein (tp), albumin (alb), total fucose (tf), protein bound fucose (pbf) and c-reactive protein (crp) were estimated. results: salivary flow rate was not altered regarding to smoking status or periodontal health status. salivary ph was lower in smokers comparing to nonsmokers, while salivary ph was not affected by periodontal health status. tf, tp and alb were higher in cp and pbf was lower in cp comparing to healthy control, while these parameters concentrations did not affect by smoking status except for alb (smokers with cp had lower alb concentration comparing to non-smokers with cp). crp was higher in smokers comparing to nonsmokers, while its value was not affected by periodontal health status. both smoking and chronic periodontitis together affect some salivary biochemical parameters, thus the concentrations of these parameters could be used as indicators for periodontal disease progression and severity in smoker with cp. both smoking and periodontal health status together should be taken in consideration when salivary composition is studied. key words: salivary biochemical compositions, saliva, smokers, chronic periodontitis, salivary flow rate, salivary glycoproteins, salivary fucose. (j bagh coll dentistry 2014; 26(1):144-149). introduction chronic periodontitis (cp) is an infectional disease that results in inflammation within supporting structure of the tooth, progressive attachment loss, and bone loss1. advanced form of the disease affects about 10% 15% of adult population worldwide 2. although, its occurrence normally involved adult individual, chronic periodontitis can appear at any age 3. periodontitis are considered as an outcome of an imbalance in the host parasite interaction. although the microbial etiology of periodontitis is well established, the extent and severity of the disease depend upon the interaction between pathogenic bacterial challenge and host response 4,5. in the presence of systemic or environmental factors, which may modify the host response to plaque accumulation, such as; diabetes, smoking or stress, the disease progression may become more aggressive6. smoking is very strong behavioral risk factor for cp. cigarette smokers are 2.5 6 times more likely to develop cp than non-smokers7. (1)assistant lecturer. department of periodontics. college of dentistry, hawler medical university. (2)assistant professor. department of basic sciences. college of dentistry, hawler medical university. (3)assistant professor. college of dentistry, hawler medical university. chronic periodontitis is more prevalent and more severe in smokers, characterized by deeper periodontal pockets, greater attachment loss and more furcation defects. smoking is considered as an independent risk factor for periodontitis8. the precise mechanisms whereby cigarette smoking can exert an effect on periodontal tissues are not completely understood, it is clear that it is still the most significant preventable risk factor for cp. its effects are related to the duration and number of cigarettes consumed 9,10 . the diagnosis of periodontal disease usually accomplished through clinical periodontal parameters including plague index, calculus index, periodontal pocket depth, bleeding index and clinical attachment loss (cal) 13. saliva, which plays an important role in the protection of periodontium, also affected by smoking 11,12. analysis of saliva can be contributed in the periodontal disease diagnosis14. saliva can be easily collected, it contained locally derived and systemically derived markers of periodontal diseases 15, however, their exact value or the optimal markers combination has not been defined 16,17. furthermore, the analysis of saliva may be offer a cost-effective approach to assess periodontal disease incidence in large population 14. the purpose of this study was to analysis some salivary parameters in smokers with cp. most studies, done on salivary compositions in chronic j bagh college dentistry vol. 26(1), march 2014 assessment of oral and maxillofacial surgery and periodontics 145 periodontitis patient, excluded smoker as it might affect the salivary compositions. little information is available on salivary compositions in smokers with chronic periodontitis patients, while no study was found included kurdistan population. subjects and methods subjects eighty systematically healthy male, their age ranged between (30-60) years old, were enrolled in the study. they were subdivided into four equal groups: non-smokers with clinically healthy periodontium (gi), smokers with clinically healthy periodontum (gii), non-smoker with cp (giii) and smoker with cp (giv). chronic periodontitis was defined as a patient who had two or more interproximal sites with cal of 4mm or more (not in the same tooth), while clinically healthy periodontium was defined as subjects with mean bleeding on probing index (bop) ≤ than 0.11 and they had no cal18 . exclusion criteria: cardiovascular disease, diabetes mellitus, hypertension, liver disease, endocrine disorders, immunodeficiency diseases, subjects had less than 20 teeth retained in their mouth, former smokers, alcohol drinkers, patients on medical treatment or had history of pervious periodontal therapy, were excluded. the clinical periodontal examinations used in this study were periodontal pocket depth (pd), cal, bop, plaque index (pi), calculus index (ci), in four surfaces of all tooth 6,19. periodontal tissue destruction was determined by cal which was measured from cementoenamel junction to the base of the periodontal pocket (varma and nyake, 2009).periodontal pocket depth was measured from gingival margin to the base of the periodontal pocket 20. severity of pd and cal was estimated (total pd /cal divided by affected surfaces) and extension of pd and cal was calculated (number of affected tooth surfaces divided by total tooth surfaces) 13. personal information was collected by including social and behavioral factors such as age, address, smoking status {measured by pack year (py); number of cigarette smoked in a day multiplied by number of years of smoking} and tooth brushing frequency (tbf). saliva collection unstimulated saliva samples were collected from all subjects in the morning (9-11 a.m.), in order to minimize the effect of diurnal variation on flow and composition 21.spitting method was used for collecting unstimulated whole saliva (uws) 22. all subjects instructed to brush their teeth and refrained from drinking, eating or smoking two hour before saliva collection. subjects was asked to rinse the mouth with distilled water for three minute to remove any food debris, then 10 minutes latter, all subjects was directed to accumulate saliva in their mouth until the desire to swallow occurred, then they spitted saliva into a sterilized graduated plastic test tube until four to five milliliter of saliva was collected (21). any blood contaminated saliva was discarded. the samples were centrifuged for ten minutes at 3000 r.p.m.23. laboratory methods unstimulated salivary flow rate was defined as the total volume of saliva produced per unit time (ml/mint) 24. the ph values of the saliva were immediately measured by using ph meter. afterward, saliva samples were stored at (-200c) until analysis 23. salivary total protein concentration was estimated using biuret reaction; salivary albumin concentration was estimated using bromocresol green method. salivary globulin concentration (glo) was estimated by subtracting salivary albumin concentration from salivary total protein 25, then albumin/ globulin ratio (alb/glo) was calculated. salivary total fucose (tf) and salivary protein bound fucose (pbf) were determined by using dische and sheetels method 26. the estimation of crp was performed by latex slide agglutination method (qualitative measurement) recorded as a negative or positive results25. statistical analysis the study variables were statistically analyzed using post hoc test, t-test and pearson chi square. results table (1) shows the mean ± sd (stander deviation) for all the parameters which have been measured in this study, while table (2) shows statistically significance differences among the groups. there was a statistically significant difference (p>.001) in smoking exposure measured in py in gii compared to giv. gii had lower smoking exposure in their life time than giv. there was a statistically significant increase in the salivary ph in gi when compared to both gii and giv. there was also a significant increase in the salivary ph in giii when comparing to both gii and giv ( p> 0.05), while there was a non significant difference in the salivary ph among j bagh college dentistry vol. 26(1), march 2014 assessment of oral and maxillofacial surgery and periodontics 146 the other groups. in general smokers had lower salivary ph than non-smokers, thus giv had the lowest ph, followed by gii. there was a highly significant decrease in the salivary tf in gi when compared to both giii, and giv (p> 0.001). there was also significant decrease in the salivary tp in gii when compared to giii (p> 0.05), while there was a nonsignificant difference between gi and gii, neither between giii and giv. patient with cp had higher salivary tf concentration than subjects with clinically healthy periodontium. there was a high significant increase in the salivary pbf in gi when compared to both giii and giv. there was also highly significant increase in the salivary pbf in gii comparing to both giii and giv (p> 0.001), while a nonsignificant difference between gi and gii, neither between giii and giv was found. patient with cp had lower protein bound fucose concentration than subjects with clinically healthy periodontium. there was a high significant decrease in the salivary tp in gi when compared to both giii and giv (p>0.05), while a non-significant difference among the other groups was found. the results showed that there was a statistically high significant decrease in the salivary albumin in gi when compared to giii, and in gii when compared to giv, and in giii when compared to giv (p> 0.001), while a nonsignificant difference between gi and gii, gi and giv was observed. gi had the lowest salivary albumin concentration while giii had the highest salivary albumin concentration. there was a statistically significant decrease in the salivary globulin in gi when compared to giii and giv (p> 0.05), while non-significant differences among the other groups were seen. gi had the lowest salivary globulin concentration. there was a statistically significant difference in the ratio of salivary albumin to globulin in giii when compared to gi, gii and giv (p> 0.05), while non-significant difference among the other groups was seen. giii had the highest ratio of salivary albumin to globulin, while gii had the lowest value. there was a statistically significant increase in salivary crp in gii comparing to gi and giii ,and a significant increase in giv comparing to gi,giii (p> 0.05),while statistically non significant differences between gii and giv,gi and giii was observed. in general smoker groups had significantly higher salivary crp than non smoker groups, as shown in figure (1). discussion in this study, the results showed that there was a high significant difference in smoking exposure in term of py between gii and giv. this result is indicated that there is a dose response relationship between smoking and periodontal health status. in the present study, there were statistically non significant differences in uws flow rate among either groups . this result was in agreement with other studies 30-34 who found that uws flow rate was not affected by periodontal health status, while this result showed a disagreement with aziz and askari who observed that uws flow rate was significantly lower in smokers compared with non-smoker 35. the result also was in disagreement with sculley and langley-evans, who found that uws flow rate significantly increased in severe cp 36. in this work, there was a statistically significance decrease in salivary ph in smokers when compared with non smokers. this result was in agreement with some authers 30,31, while it was in disagreement with gonzaalez et al 38. this disagreement might be resulted from using low sample numbers in their studies. there were statistically non significant differences between subjects with clinically healthy periodontium comparing to patients with cp, this result was in line with some studies 34,39, while the result was in disagreement with bezerra-junior et al, who found that salivary ph value was higher in cp when compared to control 32. their result might be due to the collection of saliva on fasting state in morning. low salivary ph value in smokers comparing to non smokers might be due to the higher percentage of periodontal pathogene in smokers 40, since ph level negatively correlated with the proportion of periodontal pathogenes4. according to this study, salivary tf was increased, while salivary pbf decreased in patients with cp compared with clinically healthy groups. this result might be due to increase in glycosidase activity and periodontal tissue destruction in cp 42. salivary tf and pbf were not affected by smoking. according to the results of this work, clinically healthy subjects had lower salivary total protein concentration than patients with cp. this result might be due to that these studies used saliva taking from both gender, and there were differences in age range between study groups and control in their work. smoking had statistically non significant effect on salivary tp. the result showed that there was a high significant increase in salivary albumin concentration in giii, comparing to the other groups. this indicates that cp patients had higher salivary albumin concentration than clinically healthy groups. the high albumin level in cp j bagh college dentistry vol. 26(1), march 2014 assessment of oral and maxillofacial surgery and periodontics 147 patients may be due to ulceration in sulcular epithila 45. in this study, it was also found that, smokers with cp had lower salivary albumin concentration compared with non smokers with cp. this result might be due to the thickening of the basement membrane in blood vessels, so reducing gingival blood flow in smokers compared with non smokers48. in the present study, there was a statistically significant decrease in salivary globulin concentration in gi comparing to giii and giv, while a statistically non significant difference was found among the other groups. gi had the lowest salivary globulin concentration. this result might be due to the increase in inflammatory proteins infiltrated through sulcular epithelia into gingival sulcus, then into saliva in cp patients 6, while inflammatory proteins in saliva may decrease in saliva of smokers46,47. the result showed that, salivary albumin /globulin ratio was statistically higher in giii when compared with the other groups. this result might be due to higher salivary albumin levels in non smokers with cp compared with the other groups. in the present study, smokers had higher salivary crp value than non smokers, while salivary crp value was not altered in periodontal health status. this result indicated that smoking has more effect on salivary crp than cr. both smoking and chronic periodontitis (in combination) can affect the physical properties and chemical 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(**) mean that there were highly significant differences between groups. saba final.doc j bagh college dentistry vol. 26(3), september 2014 stem cell a novel oral and maxillofacial surgery and periodontics 89 stem cells a novel approach to periodontal regeneration (a review of literature) saba samir al-sarraj, b.d.s. (1) saif sehaam saliem, b.d.s., m.sc. (2) abstract in this review of literature, the light will be concentrated on the role of stem cells as an approach in periodontal regeneration. (j bagh coll dentistry 2014; 26(3):89-97). introduction recent exciting discoveries place dentists at the forefront of engaging their patients in potentially life-saving therapiesderived from a patient’s own stem cells located in deciduousand permanent teeth. adult stem cells, including dental stemcells, have the potential, like bone marrow-derived stem cellsand adipose-derived stem cells, to cure a number of diseases. in medicine, stem cell-based treatments are being usedand investigated for conditions as diverse as parkinson’s disease, neural degeneration following brain injury, cardiovasculardisease and autoimmune diseases. stem cells will be usedin dentistry for the regeneration of dentin and/or dental pulp, biologically viable scaffolds will be used for the replacementof orofacial bone and cartilage, and defective salivary glandswill be partially or completely regenerated. dental stem cells can be obtained from the pulp of theprimary and permanent teeth, from the periodontal ligament, and from associated healthy tissues. exfoliating/extracted deciduousteeth and permanent teeth extracted for orthodontictreatment, trauma or dental implant indications are all readilyavailable sources of dental stem cells. the harvest of these dentalstem cells results in minimal trauma. dental professionals have the opportunity to make their patients aware of these new sources of stem cells that can be stored for future use as new therapies are developed for a range of diseases and injuries(1) . historical review in 2000, the national institutes of health(nih) released two studies of research on human teeth detailing the discovery of adult stem cells in impacted third molars and even more resilient stem cells in deciduous teeth. (1) high diploma student, department of periodontics, college of dentistry, baghdad university. (2) assistant professor, department of periodontics, college of dentistry, baghdad university. dentistry and medicine are evolving into new forms, in which care is being delivered with increasing frequency through biologically based approaches. the first wave of this paradigm shift in health care is likely more imminent than anyone is willing to predict at present, and its impact will eventually be felt in every medical and dental office and setting (2) . no longer will it be necessary to rely on the chance offending a cellular match from a donor, and devastating andformerly incurable diseases could potentially be treated. this is no longer science fiction. some stem cell therapies have already been approved or are being reviewed by the u.s.food and drug administration (fda), while others are atvarious stages of development. starting in the 1970s, it was discovered that cells taken from bone marrow post-natally had the ability to differentiate into bone, cartilage and marrow fat cells when they were transplanted (3) .stem cell research has increased dramatically in recent years as the potential for use of stem cells has become better understood. degenerative diseases increase in incidence with age, it can be anticipated that the need for viable and improved treatment options for these diseases will increase. patients are being treated using stem cells for cardiovascular, orthopedic, dental, oncological and other condition. new stem cell therapies will become available in the future, and in the next three years it is anticipated that stem cell product therapies for graft-versus-host disease, damaged heart muscle due to cardiac disease and knee cartilage repair will become available (4). stem cell types and sources stem cells are defined as cells that have clonegenic and self-renewing capabilities and differentiate into multiple cell lineages (5) .stem cells are the foundation cells for every organ and tissue in the body, astem cell has two defining characteristics: (i) the ability for indefinite self renewal to give rise to more stem cells; and j bagh college dentistry vol. 26(3), september 2014 stem cell a novel oral and maxillofacial surgery and periodontics 90 (ii) the ability to differentiate into a number of specialized daughter cells to perform specific functions (6). multipotent stem cells consist of three major types — ectodermal (skin and nerves), mesodermal or mesenchymal (bone, cartilage, muscle and adipose), and endodermal (intestines and other). the two main categories of stem cells are embryonic stem cells and adult stem cells, defined by their source. embryonic stem cells embryonic stem cells (escs) are derived from the cells of the inner cell mass of the blastocyst during embryonic development. escs have the capacity to differentiate into any cell type and the ability to self-replicate for numerous generations. a potential disadvantage of escs is their ability to differentiate into any cell lineage and to proliferate endlessly unless controlled (7) .the clinically observed teratoma is a tumor that is an example of escs growing into a “different and undesired tissue.” escs can be obtained only from embryos and therefore are associated with ethical issues. adult stem cells sources of adult stem cells include the umbilical cord, amniotic fluid, bone marrow, adipose tissue, brain and teeth (8) .adult stem cells are not subject to the ethical controversy that is associated with embryonic stem cells; they can also be autologous and isolated from the patient being treated, where as embryonic stem cells cannot. induced pluripotent stem cells (ips) the newly discovered ips cells are adult or somatic stem cells that have been coaxed to behave like embryonic stem cells (6) .ips cells have the capacity to generate a large quantity of stem cells as an autologous source that can be used to regenerate patient-specific tissues. however, even the authors of these recent reports have cautioned that any carcinogenic potential of ips cells should be fully investigated before any commercialization can be realized. amniotic fluid-derived stem cells (afscs) afscs can be isolated from aspirates of amniocentesis during genetic screening. an increasing number of studies have demonstrated that afscs have the capacity for remarkable proliferation and differentiation into multiple lineages such as chondrocytes (for cartilage), adipocytes (for fat), osteoblasts (for bone), myocytes (for muscle), endothelial cells, neuronlikecells and live cells (9) .the potential therapeutic value of afscs remains to be discovered. umbilical cord blood stem cells (ucbscs) ucbscs derive from the blood of the umbilical cord (10) .there is a growing interest in their capacity for self-replication and multilineage differentiation, and ucbscs have been differentiated into several cell types that resemble cells of the liver, skeletal muscle, neural tissue, pancreatic cells, immune cells and mesenchymal stem cells (11) .several studies have shown the differentiation potential of human ucbscs in treating cardiac (12) and diabetic diseases in mice (13) .the greatest disadvantage of ucbscs is that there is only one opportunity to harvest them from the umbilical cord at the time of birth. similarly, amniotic stem cells can be sourced only from amniotic fluid and are therefore subject to time constraints. bone marrow-derived stem cells (bmscs) bmscs consist of both hematopoietic stem cells that generate all types of blood cells and stromal cells (mesenchymal stem cells) that generate bone, cartilage, other connective tissues and fat. bmscs are currently the most common commercially available stem cell (4) .they can be isolated from bone marrow aspiration or from the collection of peripheral blood-derivedstem cells following chemical stimulation of the bone marrow, by means of subcutaneous injection, to release stem cells (14). adipose-derived stem cells (ascs) ascs are typically isolated from lipectomy or liposuction aspirates. they have been differentiated into adipocytes, chondrocytes, myocytes, and neuronal and osteoblast lineages, and may provide hematopoietic support. ascs express some, but certainly not all, of the cell markers that bone marrow mscs express. ascs have an advantage in that adipose tissue is plentiful in many individuals, accessible and replenishable, the ability to reconstitute tissues and organs using ascs versus other adult stem cells has yet to be comprehensively compared and documented. dental stem cells (dscs) dental stem cells (dscs) can be obtained from the pulp of the primary and permanent teeth, from the periodontal ligament, and from other tooth structure. periodontal ligamentderived stem cells are able to generate periodontal ligament and j bagh college dentistry vol. 26(3), september 2014 stem cell a novel oral and maxillofacial surgery and periodontics 91 cementum (15) .extracted third molars; exfoliating/extracted deciduous teeth; and teeth extracted for orthodontictreatment, trauma or periodontal disease are all sources of dental stem cells from the dental pulp. the dental pulp offers a source of stem cells postnatally that is readily available, with a minimally invasive process that results in minimal trauma. exfoliating or extracted deciduous teeth offer extra advantages over other teeth as a source of stem cells. stem cells from deciduous teeth have been found to grow more rapidly than those from other sources, and it is believed that this is because they may be less mature than other stem cells foundin the body. additional advantages of sourcing stem cells from exfoliating deciduous teeth are that the cells are readily available, provided they are stored until they may be needed later in life; the process does not require a patient to sacrifice a tooth to source the stem cells; and there is little or no trauma. the structures of interest to the dental profession are the enamel; dentin; dental pulp; cementum; periodontal ligament; craniofacial bones; temporomandibular joint, including bone, fibrocartilage and ligaments; skeletal muscles and tendons; skin and subcutaneous soft tissue; salivary glands; and so forth. without exception, neural crest-derived and/ormesenchymal cells form all these dental, oral and craniofacial structures during native development. several populations of adult stem cells have been explored for the regeneration of dental, oral and craniofacial structures, including bone morrow stem cells(bmscs), adiposederived stem cells (ascs) and dental stem cells(dscs), (16) which despite important differences between them, are likely the subfamily of mesenchymal stem cells (17). adult dental pulp stem cells (dpsc) an increasing number of studies have indicated dental pulp is a highly vascularized tissue and contains several niches of stem cells. the dpsc have multipotency, being capable of differentiating into odontoblasts, osteoblasts, adipocytes, chondrocytes, or neural cells. the regenerative capacity of the human dentin/pulp complex implies that dental pulp may contain the progenitors that are responsible for dentin repair (8) .first identified adult dpsc in human dental pulp in 2000 and found dpsc could regenerate a dentin-pulp-like complex, which is composed of mineralized matrix with tubules lined with odontoblasts, and fibrous tissue containing blood vessels in an arrangement similar to the dentinpulp complex found in normal human teeth. the same group further verified that dpsc posses striking features of self-renewal capability and multiline age differentiation by finding that dpsc were capable of forming ectopic dentin and associated pulp tissue in-vivo and differentiating into adipocytes and neural-like cells (18). stem cells from dental follicle (dfsc) the dental follicle is a mesenchymal tissue that surrounds the developing tooth germ. during tooth root formation, periodontal components, such as cementum, periodontal pdl, and alveolar bone, are created by dental follicle progenitors (19). stem cells from dental follicle have been isolated from follicle of human third molars and express the stem cell markers: notch1, stro-1 and nestin. dfsc were found to be able to differentiate into osteoblasts/cementoblasts, adipocytes, and neurons (20) .in addition, immortalized dental follicle cells were transplanted into immunodeficient mice and were able to recreate a new pdl-like tissue after 4 weeks. these cells may be a useful research tool for studying pdl formation and for developing regeneration therapies. periodontal ligament stem cells (pdlsc) the pdl is a specialized connective tissue, derived from dental follicle and originated from neural crest cells. recent studies have shown that mesenchymal stem cells (msc) obtained from pdl – pdlsc are multipotent cells with similar features of the bmmsc and dpsc, capable of developing different types of tissuessuch as bone and tooth associated tissues. it was reported that pdlsc could differentiate into cells that can colonize and grow on biocompatible scaffold, suggesting an easy and efficient autologous source of stem cells for bone tissue engineering in regenerative dentistry. orciani et al. (21) verified the osteogenic ability of pdlsc and pointed out that differentiating cells were also characterized by an increase of ca2+ and nitric oxide production. the authors demonstrated that local re-implantation of expanded cells in conjugation with a nitric oxide donor could represent a promising method for treatment of periodontal defects. besides osteogenic ability, differentiation of pdlsc to the cementoblastic lineage was also emphasized. the conditioned medium from developing apical tooth germ cells was shown to be able to provide a cementogenic micro environment and induce differentiation of pdlsc along the cementoblastic lineage. when transplanted into immunocompromised mice, the induced pdlsc showed tissue regenerative capacity to produce cementum/pdl -like structures, characterized by a layer of cementum j bagh college dentistry vol. 26(3), september 2014 stem cell a novel oral and maxillofacial surgery and periodontics 92 like mineralized tissues connected with pdl like collagen fibers. there is evidence that human pdl,with its mesodermal derivatives, produced neural crestlike cells. such features suggest a recapitulation of their embryonic state. the human pdl reveals itself as a viable alternative source for possible primitive precursors to be used in stem cell therapies. stem cells from human exfoliated deciduous teeth (shed) the discovery of stem cell in deciduous teeth (22).sheds light on the intriguing possibility of using dental pulp stem cells for tissue engineering. the obvious advantages of sheds are: a) higher proliferation rate compared with stem cells from permanent teeth; because they are less mature than other stem cells found in the body. b) easy to be expanded in-vitro. c) high plasticity since they can differentiate into neurons, adipocytes, osteoblasts and odontoblasts. d) readily accessible in young patients. e) especially suitable for young patients with mixeddentition. f) the process does not require a patient to sacrifice a tooth to source the stem cells. g) there is little or no trauma. stem cell properties of adult human periodontal ligament cells stem cell properties include self-renewal, multipotency, and stem cell marker expression. pdl cells obtained from extracted human molars were highly proliferative and clonogenic. further analysis revealed that pdl cells, including cell populations, expressed the stem cell markers cd105, cd166, and stro-1, cd146/ muc18. under defined culture conditions, periodontal ligament stem cells (pdlscs) differentiated into cementoblastlike cells, adipocytes, and collagen forming cells; in vivostudy indicated that pdlscs also showed the capacity to form cementum /pdl like tissues (23, 24) . human induced pluripotent stem cells (ips), which have similar properties to human embryonic stem (hes) cells, have been generated from dental tissue exfoliated deciduous teeth, apical papilla and dental pulp stem cells by viral vectors reprogramming (25). human gingival fibroblastand periodontal ligament fibroblastderived induced pluripotent stem cells showed similar characteristics to human embryonic stem cells. these induced pluripotent stem cells showed differentiation potential to form embryoid bodies in vitro and expressed genes for endoderm, ectoderm and mesoderm. teratoma formation following implantation into mouse testes was observed. induced pluripotent stem cells may be a potential autologous stem cell source for future regenerative therapy (26). the ability of human stem cells to regenerate periodontal tissues it has been demonstrated that pdl may contain progenitor cells capable of differentiation into cementoblasts in vitro. taken together, the results of these studies demonstrated the capacity of multipotent stem cells from human pdl, or periodontium-derived stem cells (pdscs), to generate a cementum-like tissue in vivo, thus representing a new therapeutic option for periodontal regeneration. periodontal diseases that lead to the destruction of periodontal tissues including periodontal ligament (pdl), cementum, and bone are a major cause of tooth loss in adults and are a substantial public-health burden worldwide. the periodontium is a topographically complex organ consisting of epithelial tissue and soft and mineralized connective tissues. several diseases affect the composition and integrity of periodontal structures causing destruction of the connective tissue matrix and cells, loss of fibrous attachment and resorption of alveolar bone (27). these changes often lead to tooth loss. the ultimate goal of periodontal treatment is to prevent further attachment loss and regenerate the periodontal supporting tissues lost because of the disease. currently, a great improvement has been made on the understanding of cellular and molecular events involved in the formation and regeneration of periodontal tissues, and tissue engineering based approaches have emerged as prospective alternatives to conventional treatments. a method to isolate and expand a stem cell population from periodontal granulation tissue has been described recently (28). these pdscs were positive for the neural stemness markers nestin& sox2 & can differentiate into various cell types of the neuronal lineage, including glial cells. however, whether pdscs are also capable of differentiation into the osteogenic lineage & regenerating periodontal tissue in vivo is unknown. at test sites where collagen sponges with pdscs were transplanted, a reformation of pdllike tissue, elements of bone, and osteocytes lacunae in the bone tissue could be seen after 6 j bagh college dentistry vol. 26(3), september 2014 stem cell a novel oral and maxillofacial surgery and periodontics 93 weeks. some putative transplanted cells were observed to attach onto root dentin surfaces. blood vessels and collagen fibers could also be shown in the pdl tissue. in the regenerated pdl tissues, immature thin fibers were obliquely arranged parallel to the bone surfaces and not in a perpendicular direction. such a fibril anchoring was never observed in the control sites. these observations were consistent for all four rats sacrificed 6 weeks postsurgery.however a "functional periodontium was not evident. downgrowth of junctional epithelium was observed to a slight degree over the investigation period. in several, new formation could be observed. periodontium –derived ligament stem cells (pdl stem cells), which have been isolated from root surface of extracted teeth, were first described by seo et al. (15) .in contrast, the current authors used human adult pdscs that had been isolated from patients who suffered from a chronic type of periodontitis with a severe degree of inflammation. the stemness of these cells was verified .several studies demonstrated that mesenchymal stem cells are capable of differentiating into osteoblast-like cells, cementoblast-like cells, and adipocytes. these data are in agreement with results demonstrating that human adult pdscs isolated from granulation tissue and subsequently expanded ex vivo are capable of differentiating into the osteogenic lineage (28). the investigation of the regenerative capacity of human stem cells in animal model prerequisites the necessity of immunocompromised animals to avoid the rejection of the stem cell grafts. in a pilot study zhao et al. (29) demonstrated that cementoblasts have a marked ability to induce mineralization in periodontal wounds while implanted dental follicle cells seem to inhibit periodontal sites of the current animal model, a cementum layer was observed on the root surfaces. this may suggest that this layer was comparatively immature and newly deposited onto previously denuded root surfaces. obviously, even in this case a "functional periodontium" seemed not to be regenerated. conceptually, the delivery of pdscs to the denuded area in periodontal defects may serve as a viable approach to promote ideal periodontal tissue regeneration. when implanted into immunocompromised rats in association with a conductive carrier material, sphere-expended human pdscs possessed the potential to develop periodontal tissues. of particular importance was the observation that the human pdscs could produce both mineralized and soft connective tissues with many morphologic features similar to cementum –like layers containing inserted sharpey fibers. this strongly implies that this tissue is of a periodontal nature. this in vivo study clearly showed that human adult pdscs transplanted into an athymic rat model were able to regenerate tissue element at different levels. however, prior to the ultimate use of pdscs in human trials, further in vivo animal studies should be conducted to optimize the cells regenerative capacity. according to recent estimates, 80–90 percent of human beings have at least one impacted “third molar” that must be removed surgically, and a large number of teeth are routinely extracted because of periodontitis or orthodontic reasons. on the other hand, deciduous teeth are routinely lost in childhood and are generally discarded. while orthodontic treatment and extraction of wisdom teeth are common in the young, there is a portion of the aged population whose third impacted molars were not removed at the correct stage, especially in rural regions and developing countries. as dental stem cells share properties with mesenchymal stem cells, dentistry should be at the forefront of stem cell translational and clinical research because of the huge numbers of patients involved and the accessibility of teeth, with the result that no major surgery is required to obtain cells. there is also considerable interest in the wider potential of these cells to treat disorders involving mesenchymal (or indeed nonmesenchymal) cell derivatives, such as in musculoskeletal disease or other life-threatening diseases cells. rationale of pdlscs used for the periodontal tissue regeneration even though bone marrow mesenchymal stem cells can contribute to the regeneration of new cementum, bone and periodontal ligament in beagle dog (30) , pdlscs are the most promising candidates for the periodontal regeneration by comparing periodontal ligament cells (pdlcs), iliac bone marrow mesenchymal stromal cells, and alveolar periosteal cells three layered cell sheets of each cell source supported with woven polyglycolic acid were transplanted autologously to the denuded root surface of beagle dog. after eight weeks, significantly more periodontal regeneration was observed as newly formed cementum and well-oriented pdl fibers in pdlc group than in the other groups. nerve filament was observed in the regenerated pdl tissue only in the pdlc group, as well as the largest amount of alveolar bone regeneration (31). more studies in beagle dog showed the formation of cementoblasts by seeding of the autologous j bagh college dentistry vol. 26(3), september 2014 stem cell a novel oral and maxillofacial surgery and periodontics 94 periodontal ligament cells (32).in an extreme experiment, extracted dog’s premolar teeth were maintained in a dry environment for a month after isolation and proliferation of the pdl cells. cultured autologous pdl cells were found to assist the re-establishment of periodontal architecture of autotransplanted teeth that is devoid of viable periodontal cells (33). to identify the cell source of pdl regeneration, researchers extracted first molars from the maxilla of 10 lacz transgenic rosa26 mice and transplanted them into the maxillary first molar socket of 10 wild type rosa26 mice. after 2 weeks, no donor cells from lacz transgenic mice were detected in the periodontal ligament space. this experiment indicated that periodontal tissue regeneration was induced by host cells, which replaced the donor periodontal tissue cells after allogenic tooth transplantation (34). nanomaterials scaffold the goal of periodontal tissue regeneration consists of establishing reparative pathways in order to treat degenerative, injury, and trauma in periodontal ligament and related bone. despite the fact that the periodontal ligament cells, mesenchymal stem cells or periodontal ligament stem cells can turn into a population of differentiated cells in certain environments, those cells cannot reconstruct three dimensional tissues without proper scaffold materials. the synthetic polymer, polysaccharide hydrogel, bio-ceramics, biomimetic peptides and collagen were investigated as transplant scaffold for tissue regeneration. scaffold materials with nanoscale topography, such as in the form of nanoparticles, nanoporous and nanofibers, show very different mechanical properties and unique biocompatibility to cell behaviors compared to flat bulk materials. the recent development in biomaterial has brought nanotechnology in improving dental implant surface modification (35,36) . three-dimensional porous nanohydroxyapatite/chitosan scaffolds were prepared through a freeze-drying process. human periodontal ligament cells were seeded onto the scaffolds, and then these scaffolds were implanted subcutaneously into athymic mice. the expression of type i collagen and alkaline phosphatase were up-regulated in ha/chitosan scaffold. after implanted in vivo, human periodontal ligament cells proliferated and grew in the scaffold with surrounding tissue (37). using a self-assembling bioactive matrix. dr. snead’s group demonstrated the ability to induce ectopic formation of enamel at chosen sites adjacent to a mouse incisor cultured in vivo under the kidney capsule. the resulting material revealed the highly organized, hierarchical structure of hydroxyapatite crystallites similar to native enamel (38). in a de novo test autologue pdl cell sheets were transplanted into a delayed replanted avulsed tooth in canine replantation model (39). the cell sheet containing original extracellular matrix showed a successful deliveryof pdl and formation of new pdl tissue for 8 weeks. however, without proper three dimensional extracellular matrix supports, pdl tissue was unable to be fully regenerated. tissue engineering with stem cells stem cells from a tiny amount of tissue, such as the dental pulp, can be multiplied or expanded to potentially sufficient numbers for healing large, clinically relevant defects. stem cells differentiating into multiple cell lineages offer the possibility that a common (stem) cell source can heal many tissues in the same patient, as opposed to harvesting healthy autologous tissue to heal like tissue. finally, stem cells can be seeded in biocompatible scaffolds in the shape of the anatomical structure that is to be replaced (40). the fundamental reasons for the effectiveness of stemcells are as follows: • unlike end-lineage cells, stem cells can be expanded ex vivo (outside the body). thus a small number of stem cells can be sufficient to heal large defects or to treat diseases. in contrast, a large number of end-lineage cellsneed to be harvested for tissue regeneration, necessitating donor site trauma and defects. • stem cells may elaborate and organize tissues in vivo, especially in the presence of vasculature. • stem cells may regulate local and systemic immune reactions of the host in ways that favor tissue regeneration. • stem cells may provide a renewable supply of tissueforming cells. applications of dental stem cells stem cells prove to be a better option as stem cell therapy could potentially lead to the regeneration of tooth roots, with pdl that can remodel with host bone, which would be functionally superior to titanium dental implants .( ibid). banking teeth and dental stem cells offers patients a viable alternative to using more invasive or ethically problematic sources of stem cells, and harvesting can be done during routine j bagh college dentistry vol. 26(3), september 2014 stem cell a novel oral and maxillofacial surgery and periodontics 95 procedures in adults and from the deciduous teeth of children. now, dental professionals have the opportunity to make their patients aware of these new sources of stem cells that can be conveniently recovered and remotely stored for future use as new therapies are developed for a range of diseases and injuries. dental applications under investigation: a) craniofacial regeneration b) cleft lip and palate c) tooth regeneration d) pulp regeneration e) periodontal ligament regeneration f) enamel and dentin production. stem cell handling and cryopreservation stem cells are released from small amounts of tissue, in the case of dental stem cells from dental pulp. the tissue is placed in an enzyme solution that releases the stem cells, which are then cultured to multiply. this can be accomplished using serum-free medium, removing the need for use of animal serum. differentiation then occurs and the cells are transplanted either alone or with a scaffold or other biomaterials, depending on the application. cryopreservation stem cells must be derived from living tissue and must be preserved. this is achieved by cryopreservation. the cells are rapidly cooled to subzero temperatures as low as −196° celsius, stopping any cellular or biochemical activity. rapid freezing is necessary to prevent ice from forming around or inside the cells and to prevent dehydration, as these would cause cell damage and death. extracted permanent and deciduous (including exfoliating) teeth can be preserved for future use with cryopreservation. research has demonstrated that stem cells derived from the dental pulp of extracted third molars retain the ability to differentiate into multiple cell types following thawing after cryopreservation using liquid nitrogen (41) stem cells derived from the periodontal ligament are viable following cryopreservation (24). after two years of cryopreservation, stem cells have been able to differentiate and to proliferate, and it has been concluded that dental stem cells dscs can undergo long-term cryopreservation (42). periodontal ligament (pdl) is the most crucial tissue to support the tooth and provide anti-shock function.although the metal implantscan be used to replaceteeth rootsand support artificial crowns, the dental implant survival rate for16 years is as low as 82.94%. consideringthe biological and technicalcomplications, the cumulativeimplant success rate is 51.97% (43). the most failurereason is related to absence of osseointegration in early healing stageor due to the occurrence of periimplantitis in long-term follow-up.both of them are closely associatedwith the poor periodontal tissueregeneration. so, it is extremelydemanded to properly regeneratepdl after implantation.since the initial conception of tissue engineering published in science(44), in the light of recent improvements in nanotechnologyand stem cell biology, the tissue regeneration in periodontology has become well understood and applied in clinic trials. tissue engineeringis the use of a combinationof functional cells, engineering andmaterials methods, and suitable biochemical and physiochemical factors to improve or replace biologicalfunctions. the main goal of periodontaltissue regeneration is the optimizationand enhancement of thebiological mechanisms of periodontalwound healing in order to maximizethe extent of the restored periodontalapparatus, i.e. alveolar bone, pdl and cementum (45). even though several regenerativeapproaches, such as guidedtissue regeneration, topicalapplicationof enamel matrix derivative, various growth factors, have been proposed in order to treat periodontal disease (46), the periodontal tissue regeneration was limited using these treatments and the efficacy is unclear. mesenchymal stem cell (msc)-mediated tissue regeneration is a promising approach for regenerative medicine for a wide range of applications. conclusions a) among all the dental-derived stem cells identified, pdlscs are unique population capable of forming an ectopic cementum/ pdl -like structure. b) with the addition of some factors (adhesion molecules, growth factors, and extracellular matrix macromolecules) present in the lesions might have stimulated the differentiation of transplanted cells into functional and specialized cells. c) both dental and non-dental derived stem cells might be potentially applied in regenerative periodontal therapies. d) agencies 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(1) abstract background:periodontal diseases and dental caries are the most common oral diseases, but they can be adequately prevented by adopting a specific health behavior and plaque control.the study was carried out to determine and compare oral health status; it included both caries experience, gingival health and oral hygiene behavior betweenfirst and fifth yearsof al-mustansiriyahdental students. materials and methods: total sample of the study consisted of 50 students at first year (25 males, 25 females)and 60 students at fifth year (30 males, 30 females). plaque andgingival indices,dental caries indices (dmfs and dmft) wererecorded to evaluateoral health status for each student. further questionnaires were given to evaluate different oral hygiene habits. results: the mean values of plaque and gingival indicesin the first year were higher than fifth year for males and females with highly significant difference at (p ≤0.01);whereas the mean values of plaque index were (1.17, 0.83 for males of first and fifth years respectively and 1.02, 0.47 for femaleof first and fifth years respectively)and the mean values of gingival index were(0.89, 0.51 for males of first and fifth years respectively and 0.78, 0.31 for femalesof first and fifth years respectively). as well as, the mean of (dmfs and dmft) were showed higher values among females than maleswhere (8.88, 6.48 for males and 10.16, 7.08 for females)in first year, while(11.90, 8.73for males and 13.33, 9.16 for females) infifth year. the percentagesof tooth brushing, mouthwash, dental floss, and tooth picks usingfor fifthyear students were higher than first year students. conclusion: differences of oral health statusand behavior rates between first and finalyearsstudents can be attributed to low level of dental education infirst year studentswhoseneed the improvements of oral hygiene education in futurewhich include the importance of proper tooth brushing and using of interdental aids to prevent the periodontal diseases and dental caries. keywords:tooth brushing,plaque index, gingival index, dental students. (j bagh coll dentistry 2017; 29(2): 71-77 ) introduction oral hygiene is the practice of keeping the mouth healthy and clean by brushing and flossing to prevent tooth decay and gingival disease sothe purpose of oral hygiene is to prevent the buildup of bacterial plaque, whichis generally accepted as the predominant etiological factor in periodontal disease (pd) and is also regarded essential for the initiation of dental caries (dc) (1, 2). consequently preventive programs of the (pd) and (dc) are based on plaque control (1, 3). dental caries is a highly prevalent chronic oral infectious disease of microbiological origin affecting hard tissues of the tooth, characterized by alternating phases of demineralization and remineralization.(4,5)it can be arrested, restricted and potentially reversed in its early stages, but it is often not self-limiting and without proper care can be progress until the tooth is destroyed. (6), also it can affect either genders with all age groups with all socioeconomic conditions (7). many studies were conducted to evaluate the decayed, missing and filled surfaces and teeth (dmfs) and (dmft). the results showed that the caries prevalence was high and it increased with age and over time, especially since the relatively recent economic growth, which has resulted in an increased consumption of refined sugar, higher than other developing countries (814). lack of awareness about oral health practices has also contributed to increase dental caries(15, 16). one of the general objectives of teaching dentistry is to train experts to motivate patients to adopt good oral hygiene practices. they are more likely to be able to do this if they themselves are motivated(1, 13). dental students are representative of the educated, urbanized, influential, and motivated class of individuals.they should be convinced that (dc) and (pd) are preventable, and should possess the knowledge and conviction of preventive principles in planning and implementation of programmers and possess leadership in this aspect(17, 18). reports on the impact of education on the oral hygiene of dental students are different. lang et al, in1977was studied oral hygiene of danish dental students, whilecavaillon et al,in 1982wasstudied oral hygiene of french dental students at the university of paris; where both (1) assi stance lecturer, depart ment of periodontal dentistry, college of dentistry, university of al-mustansiriyah. j bagh college dentistry vol. 29(2), june 2017 comparison of oral health oral and maxillofacial surgery and periodontics 72 authors noted a clear improvement in the oral hygiene practices of students during their studies. on the other hand, meister et al,in 1980did not showany improvement in the oral hygiene of students, in spite of having received information and education in a study at the university of marquette (michigan) in united states of america (19, 20, 21). the aim of the present study was to determine and compare oral health status (dc and gingivitis) and oral hygiene behavior among first (1st) and fifth (5th)years of al-mustansiriyah dental students to find out if they are practicing the dental health regimes effectively during their studying period and to assess the import of dental study on improvement of oral health status. materials and methods the sample of the study consisted of 110 dental students;50 students at 1styear (25 males and 25 females) and 60 students at 5thyear (30 males and 30 females) of al-mustansiriyah dental college, theywere randomly recruited and enrolled voluntarily in the study after a well explanation of purpose of the investigation. in this study, all students were systemically healthy, cooperative and not taking any antibiotics during the last three months (22).any pregnant and in menstrual cycle females, student had history of chronic systemic diseases with known associations with (pd) (e.g. diabetes mellitus) and any student with retentive factor of plaque (e.g. orthodontic appliance) were excluded from this study. oral examinations of students were carried out at the dental clinics teaching hospital department of periodontics of al-mustansiriyah university, under standard conditions, using plane mouth mirrors, william's periodontal probes and artificial light. all teeth were examined with the exception of third molars.oral health status was evaluated by measurement the plaque index (pli) (23), gingival index (gi)(24),(dmfs)index and (dmft)index(25).radiographs were not taken for any of the participants because of practical limitations. further questionnaires were given to evaluate different oral hygiene behavior that includes:  how often do you clean your teeth daily?  are you use dental floss, mouthwash and tooth picks? statistical methods for analysis of the results of the study were performed using (ibm® spss® statistics version 21, 2012). results the study sample was composed of 110 dental students;50 students at 1st year aged (17-19 years) divided into (25 males and 25 females) and 60 students at 5thyear aged (21-23 years) divided into (30 males and 30 females), this was shown in table (1). the means of (pli) and(gi) were higher in the 1st year students than in the 5thyear students for males and females (means of pli were 1.17, 0.83 for males and 1.02, 0.47 for females while means of gi were 0.89, 0.51 for males and 0.78, 0.31 for females at 1stand 5th years respectively) as shown in table (2) and figure (1) caries experience by gender was shown in table (3); wherethe means of(dmft) and (dmfs) indices showed higher values among females than males(8.88, 6.48 for malesand 10.16, 7.08 for females in 1st year students, while 11.90, 8.73 for males and 13.33, 9.16 for females in 5th year students). for comparisons among students, anova test was used; the results showed that there was high significant (hs) difference at p-value ≤ 0.01 among and within students for both (pli) and (gi), as shown in table (4).while, the least significant difference (lsd)test was performed for multiple comparisons between each two groups; the results showed that there wasnonsignificant (ns) difference at p-value ≥ 0.05 between 1st year-males and 1st year-femalesfor both (pli) and (gi), whilethere was significant (s) difference at p-value <0.05between 5th yearmales and 5th year-females for (gi), whereas there was(hs) difference at p-value ≤ 0.01 between1st year-males and 5th year-males; 1st year-males and5th year-females; 1st year females and 5th year-males; 1styear-females and 5th yearfemalesfor both (pli) and (gi), and5th yearmaleswith5th year-females for (pli),as shown in table (5). also, anova test was showed that there was(hs) difference at p-value ≤ 0.01 among and within groups for both (dmfs) and (dmft) indices, as shown in table (6). while, lsd test was showed that there was(ns) difference at pvalue ≥ 0.05 between 1st year-males and 1st year females; 5th year-males and 5th year-females for both(dmfs) and (dmft) indices,and 1st yearfemales with 5th year-males for (dmfs) index, whilethere was significant (s) difference at pvalue < 0.05 between 1st year-males and 5th yearmales for (dmfs) index, and1st year females with 5th year-males for (dmft) index,whereas there was (hs) difference at p-value ≤ 0.01 between 1st year-males and5th year-females; 1styear-females and 5th year-femalesfor j bagh college dentistry vol. 29(2), june 2017 comparison of oral health oral and maxillofacial surgery and periodontics 73 both(dmfs) and (dmft) indices, and1st yearmales with 5th year-males for (dmft) index,as shown in table (7). the percentagesfor once, twice and more than twice per day of tooth brushing in5thyear students were(43%, 40%, 16% respectively for males) and (33%, 56%, 10%respectively for females),while the percentages in1st year students were (48%, 44%, 8% respectively for males) and (40%, 48%, 12% respectively for females), as shown in table (8). the rates of mouthwashusing in1st year students were(16%, 20%) andin 5th year were(20%, 23%) for males and females respectively. while, of dental floss using in 1st year studentswere(20%, 24%) and in5th year students were(43%, 63%) for males and females respectively. whereas, of tooth picksusing in1st year studentswere (28%, 24%) and in5th yearstudents were(30%, 6.7%) for males and femalesrespectively, as shown in table (9). discussion this study was performed on dental students only;50 dental students at 1st year aged (17-19 years) divided into (25 males and 25 females) and 60 dental students at 5th year aged (21-23 years)to determine and compare oral health status and oral hygiene behavior among them. one might expect that dental students have good oralhygiene and periodontal health than other subjects in the community, butfrom the presented results of this study it's clearthat most of dental students didn't demonstrate an effective oral hygienethis could be due to differences in oral hygiene habits and oral hygiene practice among different subjects (26, 27).this resultwas agreed with christopher et al, in1994;waliin 2002; al-jubouryin 2006; almuhamadawyin2009. (3, 27, 28, 29) our findings were showed that females students had lower means of (pli) and (gi)than males students; which were in agreement with howat et al,in 1979; locker et al,in 2000; aljubouryin 2006;al-muhamadawyin2009(3, 27, 30, 31). this result may be possiblydue to the fact that females take care of their teeth and oral health better than males as a result ofgreater social pressure on females to be physically attractive (32).a statistically significant improvementin oral hygiene and periodontal health status (pli) and (gi) were found between 1stand 5th year students, this may be attributed tothat5th year students were more successful for removing plaque than 1st yearstudents due toentirely devoted to comprehensive dental care,also the awareness andthe knowledge of the presence of disease and its management was poor in the 1st year students(1, 18).this was in agreement with some other studies howat et al. in 1979;lang et al,in 1977; cavaillon et al,in 1982; al-muhamadawyin2009(3, 19, 20, 30), whileelmostehv et al,in 1969 ; meisterin 1980and tenenbaumin 1980 were not showed any improvement of either effective personaloral hygiene or gingival health between pre-clinical and final-year dental students due to the absence of improvement of the oral hygiene practices in students, in spite of having received information and education(1, 21, 26). the evaluation of (dc) is important. it gives an opportunity to improve hygiene, diet, and implement preventive measures in a population. the overall prevalence of (dc) in this study(dmfs and dmft) among females was higher than males; this could be attributed to the earlier eruption of teeth in females than males which enhance longer exposure to the cariogenic oral environmental factors or may be easier to food supplies by females and frequent snacking during food preparation(33). this result wasin agreementwith al-azawi in 2000; eugenio et al,in 2005; hala in 2006;abdullah in 2009;rashid et al,in 2010;shaikhet al,in 2014(11, 16, 27, 34, 35, 36).also the means of (dmfs and dmft) indices were higher in 5th year studentsthan 1st year studentscaries prevalence was high and it increased with age(9, 10). these results are attributed to the irreversibility of caries process and accumulative nature of the disease on the one hand, and the paucity of planned preventive programmers in iraq (including different methods of fluoride application) on the other hand (16, 37). so the people are verysusceptible to (dc) throughout their lifetime. (38).this result was in agreement withmaatouk et al,in 2006(13)and alhuwaiziand khamisin 2010(14). the mean of (ds) component for 1styear students was found to be higher than 5th year students; this result was opposite to the result of 5th year students, which showed that the mean of (fs) component had higher than 1st year students, and this result was reflected the low care about dental health among dental students in 1styear in comparison with 5th year students, in addition greater motivation and ease of access to dental consultation of 5th year students.this result was in agreement with maatouk et al, in2006(13). many students in 1styear were brushing their teeth at least once a day but lack the knowledge of proper tooth brushing techniques, also, this study was reported that very few students were j bagh college dentistry vol. 29(2), june 2017 comparison of oral health oral and maxillofacial surgery and periodontics 74 used practice flossing and at least some students were used 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behavior and prevalence of dental caries among 12year-old schoolchildren in dar es salaam, tanzania. tanz dent j. 2007; 14(1):1-7. table 1: descriptive statistical resultsof student's ages. groups gender no. mean s.d 1st year students males 25 18.04 0.53 females 25 18.12 0.52 5th year students males 30 22.13 0.57 females 30 22.06 0.44 table 2: descriptive statistical results of (pli) and (gi) for each group. groups index gender mean s.d 1st year students pli males 1.17 0.32 females 1.02 0.33 gi males 0.89 0.41 females 0.78 0.46 5th year students pli males 0.83 0.28 females 0.47 0.27 gi males 0.51 0.29 females 0.31 0.19 table 3: descriptive statistical results of dental caries for each group. ds ms fs dmfs dt fs ft dmft 1st year males mean 5.96 1.40 1.52 8.88 5.08 0.28 1.12 6.48 s.d 2.79 2.70 1.44 3.52 2.46 0.54 1.05 2.41 females mean 6.52 1.60 1.84 10.16 5.16 0.32 1.52 7.08 s.d 3.74 2.78 1.65 5.18 2.67 0.55 1.22 2.78 5th year males mean 5.63 2.66 3.76 11.90 4.86 0.53 3.33 8.73 s.d 3.01 4.09 3.69 5.58 2.51 0.81 3.27 3.25 females mean 4.53 2.00 6.90 13.33 3.63 0.40 5.13 9.16 s.d 2.35 2.81 4.26 4.18 1.97 0.56 3.38 2.87 j bagh college dentistry vol. 29(2), june 2017 comparison of oral health oral and maxillofacial surgery and periodontics 76 figure (1): bar chart graph for means of (pli) and (gi) for each for each group. table 4: anova test for plaque and gingival indices. index anova ss df ms f-test p-value sig. pli among groups 7.65 3 2.55 27.85 0.000 ** within groups 9.70 106 0.09 total 17.35 109 gi among groups 5.69 3 1.89 15.49 0.000 ** within groups 12.98 106 0.12 total 18.67 109 table 5: lsd test to compare the means of (pli) and (gi) among groups. index groups md se p-value sig. pli 1st year-males 1st year females 0.14 0.08 0.093 ns 5th year-males 0.34 0.08 0.000 ** 5th year-females 0.69 0.08 0.000 ** 1st year-females 5th year-males 0.19 0.08 0.017 ** 5th year-females 0.55 0.08 0.000 ** 5th year-males 5th year-females 0.35 0.07 0.000 ** gi 1st year-males 1st year females 0.11 0.09 0.264 ns 5th year-males 0.38 0.09 0.000 ** 5th year-females 0.58 0.09 0.000 ** 1st year-females 5th year-males 0.27 0.09 0.005 ** 5th year-females 0.46 0.09 0.000 ** 5th year-males 5th year-females 0.19 0.09 0.030 * table 6: anova test for dmfs and dmft. anova ss df ms f-test p-value sig. dmfs among groups 312.82 3 104.27 4.68 0.004 ** within groups 2357.36 106 22.23 total 2670.19 109 dmft among groups 135.74 3 45.24 5.48 0.002 ** within groups 874.11 106 8.24 total 1009.85 109 0 0.2 0.4 0.6 0.8 1 1.2 pli gi means of (pli) and (gi) for each male and female at 1st and 5th year's dental students 5th male 5th female 1st male 1st female j bagh college dentistry vol. 29(2), june 2017 comparison of oral health oral and maxillofacial surgery and periodontics 77 table 7: lsd test to compare the means of dmfs and dmftamong groups. groups md se p-value sig. dmfs 1st year-males 1st year females -1.28 1.33 0.339 ns 5th year-males -3.02 1.27 0.020 * 5th year-females -4.45 1.27 0.001 ** 1st year-females 5th year-males -1.74 1.27 0.176 ns 5th year-females -3.17 1.27 0.015 ** 5th year-males 5th year-females -1.43 1.21 0.242 ns dmft 1st year-males 1st year females -0.60 0.81 0.462 ns 5th year-males -2.25 0.77 0.005 ** 5th year-females -2.68 0.77 0.001 ** 1st year-females 5th year-males -1.65 0.77 0.036 * 5th year-females -2.08 0.77 0.008 ** 5th year-males 5th year-females -0.43 0.74 0.560 ns table 8: frequency of brushing in students. z gender brushing once daily twice daily ≥ 3 times daily no. % no. % no. % 1st year students males 12 48 11 44 2 8 females 10 40 12 48 3 12 5th year students males 13 43.3 12 40 5 16.7 females 10 33.3 17 56 3 10 table 9: frequency of flossing, mouth wash, and tooth picks in students. groups gender flossing mouth wash tooth picks yes no yes no yes no no. % no. % no. % no. % no. % no. % 1st year students males 5 20 20 80 4 16 21 84 7 28 18 72 females 6 24 19 76 5 20 20 80 6 24 19 76 5th year students males 13 43.3 17 56.7 6 20 24 80 9 30 21 70 females 19 63.3 11 36.7 7 23.3 23 76.7 2 6.7 28 93 المستخلص الخلفیة:تعتبر امراض اللثھ وتسوس االسنان من امراض الفم الشائعھ، لكن یمكن ان نتجنبھا بشكل تام من خالل التعود على سلوك صحي محدد وسیطرة على البالك. تم عمل ھذه الدراسھ لتحدید ومقارنة الحالھ الصحیھ للفم والتي تتضمن كالً من تسوس االسنان وصحة اللثھ المستنصریھ.السلوك الصحي للفم بین طالب المرحلة االولى والخامسھ في كلیة طب االسنان وكذلك 30طالبا في المرحلة الخامسھ ( 50اناث) و 25ذكور، 25طالبا في المرحلة االولى ( 50المواد والطرق:یتكون النموذج الكلي للدراسھمن لتقدیرالحالة الصحیة لفم كل طالب وقد تم dmfs and dmft)سوس االسنان (اناث) وقد تم عمل مؤشرات البالك واللثة وت 30ذكور، اعطاء اسئلھ اخرى للطالب لتقدیر العادات الصحیة المختلفھ للفم. النتائج:كانت قیم معدالت مؤشرات البالك واللثھ عند طالب المرحلة االولى اعلى من المرحلة الخامسة لكال من الذكور واالناث مع وجود للذكور عند المرحلتین االولى والخامسھ بالتتابع و 0,83، 1,17؛ بحیث كانت قیم معدالت مؤشر البالك ((p ≤0.01)معنوي عالي عندفرق قیم عالیة بین (dmfs and dmft)لالناثعند المرحلتین االولى والخامسھ بالتتابع) وكذلك اظھرت قیم معدالت مؤشري 0,47، 1,02 8,73، 11,90لالناث) عند المرحلة االولى بینما كانت ( 7,08، 10,16للذكور و 6,20، 8,88حیث كانت (االناث اكثر من الذكور ب لالناث) عند المرحلة الخامسة وكانت نسبة تنظیف االسنان، استخدام غسیل الفم، خیط االسنان، وعیدان االسنان 9,16، 13,33للذكور و .رحلة االولىعند طالب المرحلة الخامسھ اعلى من طالب الم االستنتاج:ان اختالفات الحالة الصحیة والمعدالت السلوكیةللفم بین طالب المرحلتین االولى والخامسة قد یكون راجع الى انخفاض مستوى نان تعلیم طب االسنان عند طالب المرحلة االولى والذین یحتاجون الى التثقیف الصحي للفم في المستقبل والذي یتضمن اھمیة تنظیف االس الصحیح واستخدام وسائل التنظیف بین االسنان لمنع امراض اللثھ وتسوس االسنان. .الكلمات الرئیسیة:تنظیف االسنان، مؤشر البالك، مؤشر اللثھ، طالب كلیة طب االسنان j bagh college dentistry vol. 29(2), june 2017 comparison of oral health oral and maxillofacial surgery and periodontics 78 j bagh college dentistry vol. 29(2), june 2017 comparison of oral health oral and maxillofacial surgery and periodontics 79 . isra'a f.doc j bagh college dentistry vol. 25(3), september 2013 effect of silica restorative dentistry 24 effect of silica layer on bonding strength of thermoplastic nylon to cold cure acrylic resin israa m. hummoudi, b.d.s., m.sc. (1) abstract background: the combination of thermoplastic nylon resin materials and auto polymerizing resin is necessary in some situation for repair and adjustment. this study evaluated shear bond strength between thermoplastic nylon material (flexible) and auto polymerizing acrylic resin subjected to holes and silica coated layer. materials and method: forty five (45) specimens were prepared from flexible acrylic bonded to auto-polymerizing acrylic resin and divided into three groups according to the surface treatments as follows: group a: 15 specimens of flexible acrylic bonded with cold-cure acrylic by holes. group b: 15 specimens of flexible acrylic bonded with cold-cure acrylic by silica coated layer. group c: 15 specimens of flexible acrylic bonded with cold-cure acrylic by combination of holes and silica coated layer. all specimens were analyzed by using instron testing machine. results: the result of this study showed that high mean values were obtained from group c (combination) while low mean values were obtained from b (silica coated layer). conclusion: it can be concluded that combination of mechanical surface treatment resulted in significant improvement in shear bond strength of flexible acrylic bonded with cold cure acrylic key words: thermoplastic nylon, silica, shear bond, hole. (j bagh coll dentistry 2013; 25(3):24-27). introduction in recent years, nylon polymer has been attracting attention as a denture base material because of a host of advantages: favorable esthetic outcome, toxological safety to patients allergic to conventional metals and resin monomers (1), higher elasticity than conventional heat-polymerizing resin, sufficient strength for use as a denture base material (2,3), and use of heat-molding instead of chemical polymerization to ease conventional challenges such as deformation during the polymerization process and the presence of non-polymerized residual monomer (4,5). furthermore, it is advantages characteristics such as higher elasticity and higher molding precision than heat-polymerizing base resins facilitate denture retention by utilizing the undercut of abutment teeth in the denture base design. this meant that metal clasps can be eliminated from denture base, which also meant that problems resulting from metal clasps such as excessive stress allergy towards metallic denture clasps can be eliminated (6,7). however, while all the above mentioned advantages are laudable, the nylon polymer does not provide adequate bonding strength to auto polymerizing resins, which are often used for the repair and adjustment of fractured nylon denture bases and failed artificial teeth. as these corrective procedures are common chair side procedures in the dental clinic, various surface treatment methods have emerged and been proven effective for bonding conventional heatpolymerizing denture base resins to auto polymerizing resins for repair and adjustment (8). (1)lecturer. college of health and medical technology. in contrast, research efforts are scanty with regard to surface treatment methods effective for bonding flexible denture base polymer to auto polymerizing repair resins. this lack of coordinated and concerted research effort could thus account for the lack of general acceptance of flexible denture base polymer in clinical dentistry. in the study, a flexible denture base polymer was first subjected to surface treatment with holes, silica layer and combination between them to assess the effect of these surface treatment on the bonding strength to auto polymerizing resin used for repair of dentures. materials and methods specimens grouping: forty five (45) specimens were constructed from thermoplastic nylon (flexible acrylic valplast-japan) bonded with auto-polymerizing acrylic (pan acrylic) and were divided into three groups according to the mechanical surface treatment as follows: • group a: 15 specimens of flexible acrylic bonded with auto polymerizing acrylic by holes (control). • group b: 15 specimens of flexible acrylic bonded with auto polymerizing acrylic by silica coating layer. • group c: 15 specimens of flexible acrylic bonded with auto polymerizing acrylic by combination of holes and silica. general preparation of flexible part of specimen wax pattern preparation: a cube of wax constructed with a dimension of (1cm x) to be used in shear bond strength test (9) according to the device instruction. j bagh college dentistry vol. 25(3), september 2013 effect of silica restorative dentistry 25 mold preparation: the conventional flasking technique for complete denture was followed in the mold preparation. each five wax pattern cube were invested them in the lower half of the flask which contained stone mixed according to the manufacturer instruction (100gm/31 ml); (p/w), and allowed to be set. the wax patterns were inserted into one half of its depth fig (1). then sprue wax gage 5mm was attached to the wax pattern at 45º angle and attached to each other fig.(2). the stone and wax pattern was coated with separating medium and allowed to be dried and then the upper half of the flask was assembled and filled with stone mixtures and allowed to be hardened for 60 minutes before the flask was opened. figure 1. wax pattern in the dental flask figure 2. spruing the wax pattern wax elimination: the flask was put in the boiling water for 15 minute and then opened it carefully and cleaned it with wax solvent and tap water and allows to be dried then the separating medium applied to the stone mold on both halves and allowed it to dry. injection the mold by thermoplastic nylon: the flask was closed and inserted to the plastic injection device clamp and make sure that the central hole of the clamp directly to the hole of the flask fig. (3,4). then the clamp was attached into the plastic injection device and put the sufficient number of ingot in the device mold (4 ingot) then the thermostat of the device allowed it to reach at temperature of 287 cº for 15 minute at this time the ingot was completely molten and ready to inject into the mold. after injected the ingot inside the mold and pressed it by the hydraulic press placed into device and pressed it approximately about 5 minute, allowed it to be harden again in the mold .then remove the clamp with the injected flask from the device and leaved it for 30 minutes to be cool at room temperature . figure 3. thermoplastic injection device figure 4. plastic injection device clamp finishing and polishing the thermoplastic part of the specimens: all specimens were removed from the flask, cleaned it from stone particles by using acrylic bur and stone bur. then cut the sprue by using separating disk and finished the specimens by using (acrylic bur stone bur and rubber point bur). preparation of the thermoplastic acrylic specimens with different surface treatment: a. holes: a hole of 2mm in diameter and 6mm in length was made in the surface of flexible part by using round bur no.5 with 1500 rpm. for 2 minutes. each specimen has 5 holes. b. silica: all specimens were coated with silica layer in concentration of 25 um by soft brush on the surface twice until dry. c. combination of hole and silica: the same procedures of making a hole and coating with silica layer but combination of them. preparation the self-cure part of the specimens -preparation the wax pattern: a rectangular of wax was constructed with a dimension (2cm x, 1cm x, 1cm x) length, width and thickness to be used in shear bond strength (9) according to the j bagh college dentistry vol. 25(3), september 2013 effect of silica restorative dentistry 26 device instruction. after wax patterns was completed each flexible part specimens was attached to one rectangular wax specimens in lshape manner so the flexible part will occupied a 1cm of the length of the rectangular wax. mold preparation: in this step cold-cure part and flexible part were flasked together in the same time to prevent any error occur during working procedures, the same flasking procedures, wax elimination procedures of flexible part of specimens were fallowed. bonding with auto polymerizing resin: the bonding was occurred after surface treatment for all specimens of all groups (holes, silica and combination of them). a-holes: all holes present in flexible part of the specimens were filled with cold cure acrylic during packing procedures of cold cure to provide mechanical attachment. bsilica: adherence was occurred during polymerization process of cold-cure acrylic after silica coated layer were applied. c-combination group: during packing the coldcure acrylic holes were filled and the surface area between the holes that coated with silica layer will provide adherence with flexible specimens fig. (5). testing: the process of measuring the shear bond strength by using instron testing machine to determine the force required separating samples in shear. the samples were attached to special clamps for holding samples. the speed of testing machine was 10mm/minute fig. (6) figure 5. final specimens figure 6. instron testing machine results the result of shear bond strength of flexible specimens bonded with auto polymerizing acrylic resin specimens received with holes (control) were (23.3 n), silica coating layer (14.6 n) and combination of (holes and silica coated layer) (24.9 n) as shown in table (1). table 1. descriptive statistics of experimental groups group a(control) with holes group b (silica) group c (holes and silica) mean 23.3 14.6 24.9 sd 0.96 1.66 2.37 max. 25.1 16.7 28.7 min. 22 12 20.6 anova test showed that highly significant differences between experimental groups p<0.01 as shown in table (2). table 2. anova test between groups f-test p-value sig between groups 82.86 p<0.01 hs to confirm the result of this study paired samples student t-test were used. the result showed highly significant differences between control group (a) and group (b) thermoplastic specimens coated with silica layer, also highly significant difference between group (b) and group (c) thermoplastic specimens received holes and silica coated layer while significant difference between group (a) control and group (b) thermoplastic denture base coated with silica layer as shown in table (3), fig. (7). table 3. t-test between groups f-test p-value sig group a & group b 14.105 p<0.01 hs group a & group c 2.17 0.049* s group b & group c 9.02 p<0.01 hs figure 7. bar chart of tested group 23.3 14.6 24.9 0 5 10 15 20 25 m ea n group a (control) with holes group b(silica) group c (holes and silica) j bagh college dentistry vol. 25(3), september 2013 effect of silica restorative dentistry 27 discussion due to the rapid growth of ageing population worldwide, the concomitant increase of denture wearers has fueled the search for new polymers as alternatives to conventional acrylic resin denture with metal clasps. the search for new denture base materials has arisen with a view to circumventing current problems associated with the use of metal clasps such as poor esthetics resulting from metal exposure and the risk of metal allergy. besides, nylon denture base polymers are gaining popularity and acceptance in clinical practice as denture base materials because of a diverse range of advantageous characteristics: their high elasticity helps to overcome problems stemming from dimensional changes during polymerization and the use of chemical polymerization averts the problem of non-polymerized, residual monomers (10). to elucidate the characteristics of nylon polymers as denture base materials, we have investigated the mechanical properties, color stability, and water sorption property of a nylon polymer, we have since reported that, despite a slightly lower color stability when compared with conventional denture base materials, nylon polymer could adequately provide the strength required for denture bases while maintaining high elasticity (11). having clarified the inherent characteristics of nylon polymers, the next logical step was to investigate if nylon dentures can be repaired and/or adjusted using auto polymerizing resins. therefore, the objective of this study was to investigate the bonding strength of nylon polymer to auto polymerizing resin. this was achieved by means of shear bond strength test (12). in the present study thermoplastic resin specimens bonded with auto polymerizing acrylic specimens by mechanical holes were highly significant increase in shear bond strength when compared with specimens coated with silica layer, this due to better bond strength was attributed to greater surface area and better penetration between repair mattered and resin holes. this result is in agreement with the work of minami et al (13) who concluded that mechanical retention in the form of a groove or hole placed in acrylic surface increased the bond strength. the lowest mean values were obtained from specimens coated with silica layer this may be low concentration were used in this study also technique used was different when compared with other studies such as coated with silica layer and then treated with silane coupling agent (9) . on the other hand high mean values were obtained in specimens treated with combination of (silica and holes) this may be due to increase surface roughness were obtained from making holes by using round bur that result highly mechanical bonded between thermoplastic and auto polymerizing resin (14). this result is in agreement with work of kern and wenger (15). moreover thermoplastic is easily affected by heat, this frictional heat caused by collision energy during silica coating procedure partially softened the thermoplastic surface, such that the adhering silica particles were cut and embedded into the thermoplastic polymer surface holes (5,16). references 1. yunus n, rashid aa, azmi ll, abu-hassan mi. some flexural properties of a nylon denture base polymer. j oral rehabil 2005; 32: 65-71. 2. katsumata y, hojo s, ino s, hamano n, watanabe t, suzuki y, et al. mechanical characterization of a flexible nylon denture base materials. bull kanagawa dent col 2007; 35: 177-82. 3. hart h, craine le, hart dj. tithe. 10th ed. tokyo: baifukan co.; 2006. pp. 443-62. 4. kuwahara k, nagahama f, kitahara k, waka m, makimura m, kimura k. a case of using non-metal clasp partial denture for the patient with the metal allergy. nihon univ j oral sci 2004; 30: 134-9. 5. shimizu h, kakigi m, fujii j, tsue f, takahashi y, effect of surface preparation using ethyl acetate on the shear bond strength of repair resin to denture base resin. j prosthodont 2008; 17: 451-5. 6. keenan pi, radford dr, clark rk. dimensional change in complete dentures fabrication by injection molding and micro wave processing. j proshet dent 2003; 89(1): 37-44. 7. jorge jh, glampalo et, machado al, vergani ce. cytotoxicity of denture base acrylic resins: a literature review. j.prosthet dent 2003; 90(20):190-3. 8. kustch vk, whitehouse j, schermerhorn k, bowers r. the evaluation and advancement of dental thermoplastics. dental town 2003; 52-56. 9. katsumata y, hojo s, ino s, hamano n, watanabe t, okada sh, et al. bonding strength of autopolymerizing resin to nylon denture base polymer. dent mat j col 2009; 28(4): 409-18. 10. parvizi a, lindquist t, schneider r, williamson d, boyer d, dawson dv. compression of the dimensional accuracy of injection –mold denture base materials to that of conventional pressure-pack acrylic resin. j prosthodont 2004; 13: 83-9. 11. kastummata y, hojo s, hamano n, watanabe t, suzuki y, ikeya h, morino t, toyoda m. color stability of a flexible nylon denture base resin. kanagawa shiigaku 2007; 42: 1405. 12. donavan te, cho gc. esthetic consideration with removable partial dentures. j calif dent assoc 2003; 31(7): 551-7. 13. minami h, suzuki s, mineskai y, kurashige h, tanaka t. in vitro evaluation of the influence of repairing condition of denture base resin on the bonding of auto polymerizing resins. j prosthet dent 2004; 91: 164-70. 14. watanab t, ino s, okada s, katsumata y, hamano n, hojo s, et al. influence of simplified silica coating method on the bonding strength of resin cement to dental alloy. dent mat j 2008; 27:16-20. 15. kern m, wegner sm. bonding to zirconia ceramic adhesion methods and their durability. dent mat j 2002; 14: 64-71. 16. negrutiu m, sinescu c, romanu m. thermoplastic resins for flexible framework removable partial dentures. j prosthet dent 2005; 55(3): 295-7. 23alan f .docx j bagh college dentistry vol. 28(3), september 2016 the effect of upper pedodontics, orthodontics and preventive dentistry 137 the effect of upper removable orthodontic appliances on oral candidal mucosal carriage alan issa saleem b.d.s., m.sc. (1) abstract background: treatment of malocclusions using removable orthodontic appliances may prepare new stagnant areas susceptible for colonization and retention of candida species, therefore; the aim of this study was to investigate the effect of upper removable orthodontic appliances on the mucosal candidal count in group of apparently healthy orthodontic patients. materials and methods: patients enrolled in this study were children aged 8-12 years having upper removable orthodontic appliances. candidal counts at six mucosal sites were estimated using imprint culture method before, 14 and 28 days during orthodontic therapy. results: whole mouth and individual mucosal sites for candidal counts increase significantly during treatment with upper removable orthodontic appliances. conclusion: the results suggest that removable orthodontic appliances treatment promotes an increase in candida counts. furthermore, removable appliance therapy had a positive transient influence upon the prevalence and density of oral candidal carriage. this can indicate a more cautious approach when providing orthodontic treatments for immunocompromised children regarding the increased possibility of candidal infection. keywords: removable appliance, colonization, candida. (j bagh coll dentistry 2016; 28(3):137-141). introduction malocclusions are known as the 3rd most common oral health problems, which caused a number of complications (1). the advent of orthodontic treatment became increasingly popular for correcting these complications (2). patients undergoing orthodontic treatment wear either removable orthodontic appliance (roa) or fixed orthodontic appliance (foa), and at the beginning orthodontic procedures were considered non-invasive, but after that they found that these appliances can be associated by difficulty in cleaning during treatment, retentive areas created that favor biofilm accumulation and bacterial growth (3). further studies showed that wearing orthodontic appliances brought about several intraoral changes, such as increased biofilm accumulation, elevated microbial colonization, potential enamel demineralization, alterations in saliva buffer capacity, and even caused a harmful effect on periodontal tissues (4,5). candida species are known as the most common human oral micro flora, which colonizes in the oral cavity of up to 60% of all healthy individuals, therefore oral candidosis considered is an accepted complication of upper removable appliance (ura) wear. the density with which the oral mucosa is colonized by candida is significantly increased in wearers of both fixed and removable orthodontic appliances (6,7). (1)lecturer. department of orthodontics, college of dentistry, university of baghdad candida is recovered more frequently from certain sites in the mouths of ura wearers namely the anterior and posterior palate, anterior tongue and left buccal mucosa (6). in terms of site, the highest prevalence of candida carriage during orthodontic therapy with ura was the palate (much of which is covered by the ura), despite the fitting surface of the appliance itself has been found to be more densely colonized by candida than any of the mucosal sites sampled during the period of ura wear (7). hibino et al. (8) reported c. albicans as an opportunistic pathogen, which commonly isolated from the mouth of orthodontic patients with removable appliances, formed candida biofilm. these microorganisms in the biofilm sometimes may enter into blood stream and cause candidemia. during orthodontic therapy with upper removable orthodontic appliances, significant increase in the prevalence of candida carriage has been noted (7). although, there are several investigations in medical literature studied the effect of fixed orthodontic appliances on oral candida colonization (9-11). more researches are needed for investigating oral candida carriers in patients with removable orthodontic appliances (12), and it is also important to determine the oral microbial alteration in patients undergoing orthodontic treatment in order to maintain the oral health of the patients, therefore; the aim of this study was to investigate the effect of upper removable orthodontic appliances on the mucosal candida count in group of apparently healthy orthodontic patients. j bagh college dentistry vol. 28(3), september 2016 the effect of upper pedodontics, orthodontics and preventive dentistry 138 materials and methods twenty-four patients 13 males and 11 females aged 8-12 years old undergoing orthodontic treatment with upper removable appliances (uras) were selected from patients attending the department of orthodontics / college of dentistry / baghdad university. the medical history of each individual was checked for factors known to affect carriage of oral candida, i.e. diabetes, anemia and immunosuppression. similarly, individuals who had received or were currently receiving treatment with antibiotics, antifungals or steroids in the previous three months were excluded from the study. none of those included had previously experienced orthodontic treatment or worn any type of oral prosthesis. uras were worn for at least 4 weeks, continuously day and night. appliances were brushed with tooth brush and tooth paste as an oral hygiene measure. appliances were in passive contact with mucosa, although slight pressure would result from chewing. to standardize the patient population, all upper removable appliances were made by the same technician and they were made of an acrylic base, retention elements and active element (adams' clasp, hawley arch and active element zspring). the selected patients were instructed to brush and use dental floss three times a day. for standardization, the oral hygiene of all the patients was provided by their parents throughout the study. the oral candidal carriage of the subjects were taken from six intraoral mucosal sites (anterior palate, posterior palate, anterior tongue, posterior tongue, left cheek, right cheek) using the imprint culture method (7). in brief, sterile foam pads soaked in sabouraud's broth were applied to each mucosal surface and then placed with the contact side down on sabouraud's agar (oxoid). the agar plates were then incubated aerobically at 37°c for 48 hr., the foam pads were removed, and the plates were re-incubated for an additional 72 hr. the candidal colonies were counted separately for each site by visual examination and expressed as colony-forming units (cfu)/mm2 (13). swabs from the patients were taken three times during the orthodontic treatment, the first sample was taken before the insertion of upper removable orthodontic appliance (t1); the second sample was taken after 14 days (t2); and lastly the third sample taken after 28 days (t3) . statistical analyses data were analyzed using spss (statistical package of social science) software version 19. in this study the following statistics were used descriptive statistics; including medians, means, standard deviations, minimum and maximum values and statistical tables. inferential statistics including: shapiro-wilk test: to test the normality of the distribution of the data. wilcoxon signed ranks test: to detect side difference. kruskal-wallis h test: to compare the measured colony forming unit among the regions and durations mann-whitney u test: to test the gender difference and after kruskal-wallis h test to test any statistically significant difference between each two regions and durations. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results firstly, data were checked for normality of distribution using shapiro-wilk test and the results indicated that the data were not normally distributed, so non – parametric tests were used. comparison the right and left sides and the anterior and posterior areas in different regions was performed using wilcoxon signed ranks test and the results revealed non–significant difference in each gender so, the right and left and the anterior and posterior areas were pooled. using mann-whitney u test, gender difference was evaluated and the results indicated non significant gender difference, hence the data of both genders were pooled also and effects of different areas and durations were assessed using kruskalwallis h test then mann-whitney u test. descriptive statistics and region difference of colony forming unit in each period was presented table (1). there was highly significant regions' difference in t1 and t2 only. comparison of each two regions in these periods revealed highly significant difference between cheek and tongue and between palate and tongue (table 2). descriptive statistics and duration difference of colony forming unit in each region was demonstrated in table (3). generally, the median values increased dramatically from t1 to t3 with a highly significant difference. j bagh college dentistry vol. 28(3), september 2016 the effect of upper pedodontics, orthodontics and preventive dentistry 139 comparing each two periods revealed a highly significant difference in all regions. table 1: descriptive statistics and region difference of colony forming unit in each period durations regions descriptive statistics region difference n median mean s.d. min. max. x2 p-value t1 cheek 48 1 0.56 0.58 0 2 28.273 0.000 (hs) palate 48 0 0.52 0.77 0 3 tongue 48 1 1.25 0.73 0 3 t2 cheek 48 2 1.77 1.24 0 4 17.780 0.000 (hs) palate 48 2 1.75 1.21 0 4 tongue 48 3 2.71 1.03 1 5 t3 cheek 48 3 3.54 1.56 0 6 2.296 0.317 (ns) palate 48 3 3.15 1.47 1 6 tongue 48 3 3.52 1.52 0 6 table 2: comparing each two regions in each period durations cheek vs. palate cheek vs. tongue palate vs. tongue mw p-value mw p-value mw p-value t1 1042 0.362 (ns) 583 0.000 (hs) 567 0.000 (hs) t2 1137 0.91 (ns) 684 0.000 (hs) 654 0.000 (hs) mw= mann-whitney u test table 3: descriptive statistics and duration difference of colony forming unit in each region regions durations descriptive statistics durations' difference n median mean s.d. min. max. x2 p-value cheek t1 48 1 0.56 0.58 0 2 73.118 0.000 (hs) t2 48 2 1.77 1.24 0 4 t3 48 3 3.54 1.56 0 6 palate t1 48 0 0.52 0.77 0 3 67.973 0.000 (hs) t2 48 2 1.75 1.21 0 4 t3 48 3 3.15 1.47 1 6 tongue t1 48 1 1.25 0.73 0 3 62.596 0.000 (hs) t2 48 3 2.71 1.03 1 5 t3 48 3 3.52 1.52 0 6 table 4: comparing each two periods in each region regions t1-t2 t1-t3 t2-t3 mw p-value mw p-value mw p-value cheek 513 0.000 (hs) 109 0.000 (hs) 462.5 0.000 (hs) palate 479 0.000 (hs) 133.5 0.000 (hs) 568 0.000 (hs) tongue 321 0.000 (hs) 229.5 0.000 (hs) 767.5 0.003 (hs) mw= mann-whitney u test discussion the oral cavity presents countless species of microorganisms particularly candida, which are frequently seen in the oral cavity of almost half of the healthy population, and may be associated with orthodontic appliance contamination and pathologies. wearing orthodontic appliance, is also known as a risk factor, can promote colonization of candida and result in oral candidiasis (14). in this study comparison in each duration among cheek, palate and tongue revealed a high significant difference in t1 and t2. this result is comparable to that reported by arendorf and addy (7) who found an increase in candidal counts at 5 months of removable orthodontic appliance use, and considering that the counts further increased in regions where an appliance was being worn. they also noted that the candidal counts increased in regions where no appliance was present. the results of this study showed that the difference is non–significant for t3 duration while it is highly significant for t1 and t2 duration this may be attributed to relationship between candida and the resistance of patients, where an increase in the candida population may cause a temporary weakening of the resistance of the body during the initial phase after the application of the roa. the amount of candida j bagh college dentistry vol. 28(3), september 2016 the effect of upper pedodontics, orthodontics and preventive dentistry 140 gradually declined, which may be due to the gradual adaptation of the patients to the new oral environment. regional differences may also contribute to the variations observed. moreover, full recoveries of systemic and local resistance were also observed. the increase in the number of candida colonies may be associated with an increase in the amount of plaque and microbes in the oral cavity of patients shortly after roas start to be worn. in this study comparison in each region (cheek, palate and tongue) among different durations, revealed a high significant difference with the highest median values for all the three regions were found during t3 where the lowest were found at t1, this agreed with arendorf and walker (13) who found that the presence of a prosthesis or an appliance increase candidal numbers, not only at the occluded site, but at all mucosal sites sampled. arendorf and addy (7) investigated 33 patients who underwent roa therapy and found a direct relationship between the presence of roa and candidal species. the incidence of oral candida among normals prior to the application of removable appliances was lower than that reported after 28 days. this may be attributed to the fact that the patients brushed their teeth accurately prior to sampling, thus reducing the number of microbes in the oral cavity. the rate of pathogenesis and number of colonies of oral candida significantly increased compared with those prior to treatment. these findings may be due to the roas resulting in a lowering of the local defense mechanism of oral mucosal cells. oral mucosal cells, which act as mechanical barriers, and metabolism play important roles in increasing the resistance of the mouth to infection. thus candida can easily adhere to any damage in the oral epithelia (15). adhesion of candida to the parts of the roa, may affect colony formation. the extent of adhesion is dependent on the surface roughness and type of material used. the adhesion of candida to the surface of orthodontic appliances should be studied further. there is also a relationship between candida and the resistance of patients, where an increase in the candida population may cause a temporary weakening of the resistance of the body during the initial phase of application of the roa. there are few published studies to be compared with the present study. addy et al. (6) using imprint cultures to the mucosa of ura wearers and non-wearers recorded prevalence of 52 and 46% respectively. a later study, utilizing the imprint culture technique to sample of mucosal surfaces and uras demonstrated an increase in the prevalence of candida from 39.4 to 78.8% when uras were worn (7). it is believed that uras increase the risk of oral carriage of yeasts by providing an ecological niche (6,7). c. albicans and other candida species readily adhere to oral epithelia that are covered by acrylic dental plates and to the surface of the acrylic plates in contact with the mucosa (7,15). long-term wearing of dental removable appliances is a major factor for the colonization of candida on mucous surfaces; this colonization may lead to levels sufficiently high to give rise to oral candidosis particularly affecting the mucosa beneath the appliance aid (6). other studies have shown that oral candidosis is associated with a high density of yeast determined by imprint culture (5). multiple areas of the oral mucosa including the dorsum of tongue, the main reservoir for candida in the oral cavity, been sampled by imprint culture the sensitivity of this isolation method would have been significantly higher (5). the site prevalence and intra–oral density of candidal organisms may be increased by local factors including prosthesis. however, the prevalence of candidal recovery at some sites and candidal densities at all sites were significantly increased in both fixed and removable appliance wearers and that there seems to be a direct relationship between the presence of a removable appliance, candida and low salivary ph levels. it is important to emphasize that no healthy patients developed candida infection from the orthodontic appliances. however, there seems to be at end that some non-candida carriers converted to candida carriers following the insertion of the appliances by unknown mechanism. this may indicate a more cautious approach when providing orthodontic treatments to immunocompromised children concerning the possible increased risk of candidal infection. orthodontic appliances may favor the adherence of candida to epithelial cells but do not influence the presence of them in saliva. the findings of previous studies therefore suggest that the increase in candidal counts is attributable to poor oral hygiene. this hypothesis is supported by the findings of this study of multiple positive significant correlations between the candidal counts and removable appliance wearers. furthermore, the positive correlation between the candidal counts observed in the removable appliance group at t3 may also be another indication of a possible j bagh college dentistry vol. 28(3), september 2016 the effect of upper pedodontics, orthodontics and preventive dentistry 141 relationship between poor oral hygiene and candidal presence. in conclusion, treatment of malocclusions using removable appliances may prepare new stagnant areas susceptible for colonization and retention of candida species. patients should be motivated each visit for oral hygiene during their orthodontic therapy. references 1. castellanos-cosano l, machuca-portillo g, mendozamendoza a, iglesias-linares a, sotopineda l, solano-reina e. integrated periodontal, orthodontic, and prosthodontic treatment in a case of severe generalized aggressive periodontitis. quintessence int 2013; 44: 481-5. 2. ratson t. diagnosis and treatment of supernumerary teeth in the premaxillary region: a literature review. refuathapehvehashinayim 2013; 30: 26-30 3. lee sj, kho hs, lee sw, jang ws. experimental salivary pellicles on the surface of orthodontic materials. am j orthod dentofac orthop 2001; 119: 59–66. 4. condo r, casaglia a, condo sg, cerroni l. plaque retention on elastomeric ligatures. an in vivo study. j oral implantol 2013; 5: 92-9. 5. darodeh n , shehabi a , al-bitar z , al-omari l, badran s, al-omiri m, et al. candida colonization in patients with fixed orthodontic appliances: the importance of some nutritional and salivary factors. afric j microbio res 2011; 5: 2150-54. 6. addy m, shaw wc, hansford p, hopkins m. the effect of orthodontic appliances on the distribution of candida and plaque in adolescents. br j orthod 1982; 9: 158–63 7. arendorf tm, addy m. candidal carriage and plaque distribution before, during and after removable orthodontic appliance therapy. j clin periodontol 1985; 12: 360–8. 8. hibino k, wong rw, hagg u, samaranayake lp. the effects of orthodontic appliances on candida in the human mouth. int j paediatr dent 2009; 19: 301-8. 9. arslan sg, akpolat n, kama jd, ozer t, hamamci o. one-year follow-up of the effect of fixed orthodontic treatment on colonization by oral candida. j oral pathol med 2008; 37: 26-9. 10. saloom hf, mohammed-salih hs, rasheed sf. the influence of different types of fixed orthodontic appliance on the growth and adherence of microorganisms (in vitro study). j clin exp dent 2013; 5: 36-41. 11. sukontapatipark w, el-agroudi ma, selliseth nj, thunold k, selvig ka. bacterial colonization associated with fixed orthodontic appliances: a scanning electron microscopy study. eur j orthod2001; 23: 475-84. 12. hibino k, wong rw, hagg u, samaranayake lp. the effects of orthodontic appliances on candida in the human mouth. int j paediatr dent 2009; 19: 301-8 13. arendorf tm, walker dm. oral candidal populations in health and disease. br dent j 1979; 147: 267-72. 14. barbeau j, seguin j, goulet jp, de koninck l, avon sl, lalonde b, et al. reassessing the presence of candida albicans in denture-related stomatitis. oral surg oral med oral pathol oral radiol endod 2003; 95: 51-9. 15. odds fc. candida and candidosis, a review and bibliography. london: bailliere tindall; 1988. wisam f.doc j bagh college dentistry vol. 28(2), june 2016 salivary calcium binding pedodontics, orthodontics and preventive dentistry 149 a salivary calcium binding protein in patients with oral squamous cell carcinoma in relation to smoking wisam hamid edan, b.d.s., m.sc. (1) sulafa khalid el-samarrai, b.d.s., m.sc., ph.d. (2) abstract background: calcium binding protein regulates many important cellular functions such as cell proliferation, cell motility and differentiation. over-expression of calcium bp was detected in different human cancers, including oral squamous cell carcinoma (oscc). therefore the aim of the present study was to evaluate the role of calcium binding protein in oscc, quantified in stimulated saliva, and its association with smoking. materials and methods: the present study included 20 patients with oral squamous cell carcinoma who used to be smokers, and 40 control subjects. calcium binding protein was assessed by elisa technique, in stimulated saliva collected from all groups. results: salivary calcium binding protein was significantly higher in smoker patients with oral squamous cell carcinoma than smoker and nonsmoker control healthy looking subjects. conclusions: salivary calcium binding protein play a significant role, as a non-invasive approach, in the early diagnosis and follow up of oral squamous cell carcinoma patients. key words: oscc, calcium binding protein, saliva, smoking. (j bagh coll dentistry 2016; 28(2):149-151). introduction the chronologic sequence of histologic stages of oral squamous cell carcinoma includes the transition from benign hyperplasia to dysplasia to carcinoma in-situ, and then ultimately followed by invasive squamous cell carcinoma. this phenotypic alteration is the results of multistep genetic mutations and altered gene expression (1,2). tobacco is claimed to be one of the major environmental carcinogenic agents that are responsible for such mutations (3,4). analysis of saliva proteins, a non-invasive substitute to tissue biopsy, from patients with oscc is a promising approach for diagnosis, monitoring and therapeutic targeting the s100 proteins are a multigene calcium-binding family, comprising more than 20 different proteins which are encoded by a separate gene and are expressed in a controlled tissue specific or cell type-specific manner (7). they are small, acidic proteins of 10-12 kda and form the largest family of calcium binding proteins. they regulate many important cellular functions such as cytoskeleton organization, homeostasis, stress response, cell proliferation, cell motility and differentiation (8). over-expression of calcium protein was detected in different human cancers, presenting increased expression in neoplastic tumor cells as well as infiltrating immune cells (9-12). s100 a9 over-expression was also reported in oral squamous cell carcinoma (oscc) (13). (1)ph.d. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. thus the aim of the present study was to evaluate the role of calcium binding protein in oscc, quantified in stimulated saliva, and its association with smoking. subjects, materials and method the present study included 20 patients with oral squamous cell carcinoma who used to be smokers. for the purpose of comparison, 20 apparently healthy smokers and another 20 nonsmokers were enrolled. control subjects were chosen in such a way to be matched with age and gender of the patients. patients age was from 40 to 70 years, included (8) females and (12) males. the study was conducted in ghazi al-hariri hospital, al-yarmook teaching hospital and alkadhimiya teaching hospital in baghdad. the study was held from october 2014 through february 2015. from each patient and control subjects a sample of stimulated saliva (400^l) was obtained between 8:00 am and 11:00 am. saliva was stored at -80c° till the time of analysis. calcium binding protein was assessed by elisa (elabscience; china) statistical analysis was performed using spss version 16. being a non -normally distributed variable, comparison of mean calcium binding concentration among groups was done using the non-parametric kruskal wallis test and mann whitney u test. p-value was considered significant when it was less than or equal to 0.05 and highly significant when it was less than or equal to 0.001. j bagh college dentistry vol. 28(2), june 2016 salivary calcium binding pedodontics, orthodontics and preventive dentistry 150 results median values of calcium bp level was significantly higher in smoker patients in comparison to other two groups (p <0.001), as shown in table 1 and figure 1. also there was a significant difference in median values of calcium bp between smoker control subjects and non-smoker control subjects (p <0.05), as shown in tables 1 and 2 and figure 1. performing a regression analysis between calcium bp and smoking, represented by study groups, revealed a positive significant correlation, as shown in figure 2. table 1: descriptive statistics of calcium bp in the three study groups groups n median mean s.d. min. max. smoker carcinoma 20 11.943 14.88 5.19 0.58 73.93 smoker no carcinoma 20 4.897 5.884 3.09 1.36 11.63 non-smoker no carcinoma 20 2.482 3.384 2.77 0.21 7.79 kruskal wallis h test = 20.331, d.f. = 2, p-value = <0.001 fig.1: comparison of median values of calcium bp among the three studied groups table 2: statistical differences among the study groups groups mann-whitney u test d.f. p-value group 1 vs. group 2 77 1 <0.001 group 1 vs. group 3 49 1 <0.001 group 2 vs. group 3 123.5 1 <0.039 r=0.464, r2=0.215, p<0.001 fig. 2: regression analysis between smoking and salivary cb protein level in groups enrolled in the present study (1= non-smoker no carcinoma, 2= smoker no carcinoma, 3=smoker with carcinoma) j bagh college dentistry vol. 28(2), june 2016 salivary calcium binding pedodontics, orthodontics and preventive dentistry 151 discussion the results of the present showed an overexpression of salivary calcium binding protein in patients with oscc in comparison with smoker and non-smoker control subjects with statistically highly significant differences. overexpression of calcium binding protein in patients with oscc was shown by several other studies, in agreement with the result of the present study (14-17). also several studies showed over-expression of calcium binding protein in smoker patients without carcinoma (18,19). tobacco smoking may induce the formation of reactive oxygen species that alter the function of rough endoplasmic reticulum, subsequently increasing the expression of several transcriptional factors that ultimately induces up-regulation of salivary proteomics including calcium binding proteins. the role of the calcium binding protein in oscc is not fully understood, nevertheless andrea mueller et al. (20) suggested that the interaction among calcium, p53 (a tumor suppressor protein) and calcium binding protein will ultimately lead to suppression of p53 and enhancement of cell growth and evasion of apoptosis. thus salivary calcium binding proteins may have a key role as a non-invasive marker in the diagnosis and follow up of patients with oscc. in conclusion, salivary calcium binding protein can be used as a non-invasive alternative method for the diagnosis and monitoring of oscc. references 1. napier ss, speight pm. natural history of potentially malignant oral lesions and conditions: an overview of the literature. j oral pathol med 2008; 37(1 ):1-10 2. reibel j. prognosis of oral pre-malignant lesions: significance of clinical, histopathological, and molecular biological characteristics. crit rev oral biol med 2003; 14(1): 47-62. 3. sugimura t, kumimoto h, tohnai i, fukui t,matsuo k, tsurusako s, et al. gene-environment interaction involved in oral carcinogenesis: molecular epidemiological study for metabolic and dna repair gene polymorphisms. j oral pathol med 2006; 35(1):11-8. 4. brennan ja, boyle jo, kochwm, goodman sn, hruban rh, eby yj, et al. association between cigarette smoking and mutation of the p53 gene in squamous-cell carcinoma of the head and neck. n engl j med 1995; 332(11): 712-7. 5. cheng yl, rees t, wright j. a review of research on salivary biomarkers for oral cancer detection. clinical and translational medicine 2014; 3: 3 6. mittal s, bansal v, garg s, atreja g, bansal s. the diagnostic role of salivaa review. j clin exp dent 2011; 3(4): e314-20. 7. salama i, malone ps, mihaimeed f, jones jl. a review of the s100 proteins in cancer. eur j surg oncol 2008; 34: 357-64. 8. chen h, xu c, jin q, liu z. s100 protein family in human cancer. am j cancer res 2014; 4(2): 89-115. 9. imazawa m, hibi k, fujitake s, kodera y, ito akiyama s, et al. s100a2 overexpression is frequently observed in esophageal squamous cell carcinoma. anticancer res 2005; 25: 1247-50. 10. matsumoto k, irie a, satoh t, ishii j, iwabuchi k, iwamura m, et al. expression of s100a2 and s100a4 predicts for disease progression and patient survival in bladder cancer. urology 2007; 70: 602-7. 11. mckiernan e, mcdermott ew, evoy d, crown j, duffy mj. the role of s100 genes in breast cancer progression. tumour biol 2011; 32: 441-50. 12. ohuchida k, mizumoto k, miyasaka y, yu j, cui l, yamaguchi h, et al. overexpression of s100 a2 in pancreatic cancer correlates with progression and poor prognosis. j pathol 2007; 213: 275-82. 13. tsai st, jin yt, tsai wc, wang st, lin yc, chang mt, et al. s100a2. a potential marker for early recurrence in early-stage oral cancer. oral oncol 2005; 41: 349-57. 14. nagler r, bahar g, shpitzer t, feinmesser r. concomitant analysis of salivary tumor markers-a new diagnostic tool for oral cancer. clin cancer res 2006; 12(13): 3979-84. 15. hu s, arellano m, boontheung p, wang j, zhou h, jiang j, elashoff d, wei r, loo ja, wong dt. salivary proteomics for oral cancer biomarker discovery. clin cancer res 2008; 14(19): 6246-52. 16. balan jj, rao rs, premalatha br, patil s. analysis of tumor marker ca 125 in saliva of normal and oral squamous cell carcinoma patients: a comparative study. j contemp dent pract 2012; 13(5): 671-5. 17. jessie k, jayapalan jj, ong kc, abdul rahim zh, zain rm, wong kt, hashim oh. aberrant proteins in the saliva of patients with oral squamous cell carcinoma. electrophoresis 2013; 34(17): 2495-502. 18. haigh bj, stewart kw, whelan jrk, barnett mpg, smolenski ga, wheeler tt. alterations in the salivary proteome associated with periodontitis. j clin periodontol 2010; 37(3): 241-7. 19. gonçalves ldr, soares mr, nogueira fcs, et al. comparative proteomic analysis of whole saliva from chronic periodontitis patients. j proteomics 2010; 73(7): 1334-41. 20. mueller a, schafer bw, hochli sm, ferrari cwh, weibel m, makek m. the calcium-binding protein s100a2 interacts with p53 and modulates its transcriptional activity. j biol chem 2005; 280: 29186-93. j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 33 a comparison of vertical marginal fit of different brands of translucent zirconia crown restorations sattar j. abdul-zahra al hmedat, b.d.s., m.sc. (1) abstract background: as the development of zirconia crown using cad/cam technology, the usage of full zirconia crown is gradually increased. the aim of this in-vitro study was to evaluate and contrast the vertical marginal fit of single allceramic translucent zirconia crowns constructed from different brands translucent zirconia blanks. materials and methods: an acrylic resin model of a left maxillary premolar was prepared all around the tooth with (1 mm) depth and 3d scanning to get fifteen stl files, then distributed into three groups (imes-icor, whitepeaks and dental direct), 3d scanning and milling machine by imes-icor cad/cam devise. marginal gaps along vertical planes were measured at four indentations at the (mid mesial, mid distal, mid buccal, mid palatal) using a light microscope at a magnification of x100. one-way anova, lsd tests were performed to determine the mean and standard deviation of the three blanks groups. results: statistically high significant difference (p < 0.00) was found between the groups. the marginal gap value of the groups varied whitepeaks crowns was (105.42 ± 7) μm, which was significantly higher than the two overall mean marginal gap measured for the imes-icor crowns (59.3 ± 4) μm and dental direct crowns (54.5 ± 4.9) μm, the dental direct which was lowers overall mean vertical gap measurement. conclusions: the marginal gap values of dental direct crowns is considerably lower than that of whitepeaks crown, the marginal gap values of all the groups made of monolithic high translucent y-tzp demonstrated acceptable marginal gaps values. key words: vertical marginal fit, crown, zirconia. . (j bagh coll dentistry 2017; 29(2):33-41) introduction at the last decay the all-ceramic restorations rapidly improved combined with the use of computer-aided design (cad)/computer-aided manufacturing (cam), have been continuously developed and upgraded in prosthetic dentistry in association with zirconium oxide, used primarily for the restoration of single crowns and fixed partial dentures (fpds) in both the anterior and posterior regions. metal free, high esthetics; excellent biocompatibility and high flexural strength have fueled public demand for all ceramic instead of porcelain-fused to metal crowns since all-ceramic crowns are associated with some disadvantages. ceramic is brittle and has low tensile strength and fracture toughness due to unavoidable inherent imperfection as they potentiate cracks when subjected to stress. the most common complication with all-ceramic crowns is fracture (1). veneering a cad/cam designed core provides high strength with high optical quality, which is commonly being used in the recent dentistry. however, veneering material is usually weaker than the core material, which leads to the typical failure pattern, chipping of the veneer layer (2). some manufacturers have introduced a new approach by designing a full contour crown (no veneering) from a cad/cam ingot to avoid the problem from veneer chipping. (1) assistant lecturer. department of conservative dentistry, college of dentistry, university of kufa. ips e-max cad (lithium disilicate glassceramic) and ips empress cad (leucite) are examples of these crowns. the flexural strength of lithium disilicate glass-ceramic and leucite glass ceramic are around 350 mpa and 160 mpa respectively (3). these materials are suitable for anterior and premolars restorations only because the strength is not sufficient to withstand occlusal forces generated by posterior teeth. this led to development of dental zirconia, which is currently one of the toughest ceramic materials. garvie (4) described it as ceramic steelas it has a flexural strength of 1000 mpa (3) zirconia was first used in dentistry in 1990s although first application in orthopedics occurred much earlier in 1969 (4). zirconia is a polycrystalline (directly sintering crystals together without the glass phase to form a dense yttria (y2o3), magnesia (mgo), and ceria (ceo2) are common oxides added to zirconia for a toughening mechanism (5). it has flexural strength of approximately 900 mpa to 1100 mpa, and fracture toughness of 8-10 mpa m1/2 (6). zirconia is the toughest dental ceramic available in dentistry. the particle size is 0.1 μm to 0.5 μm (7), white in color and possessing relatively great strength, it has been used to fabricate crowns and fpds frameworks as an alternative to metal. zirconia framework is usually veneered with porcelain, leucite reinforced glass ceramic. because of the possibility of chipping the veneer layer, the idea of fabricating a crown made entirely from zirconia was proposed. that would j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 34 merge the strength and the esthetics of the zirconia material, for fabrication of full contour crowns. several companies have been working on different processing techniques to improve the esthetic result of zirconia. that has resulted in a new generation of zirconia with a higher translucency than the traditional zirconia used for core fabrication only. in this paper, we referred to zirconia with higher translucency as “translucent zirconia,” and to the zirconia for core fabrication as “non-translucent traditional zirconia.” translucent zirconia is proposed that less tooth reduction is needed to achieve the same or greater overall strength in the crown when compared with the reduction needed for lithium disilicate crowns. many companies have been working of manufacturing translucent zirconia blanks therefore the objective of this study to comparison the vertical marginal fit among these brands. optical quality of translucency zirconia and its impact on strength the processing techniques mentioned by researchers, which led to increased translucency in the processed zirconia. adding titanium oxide to yttrium-stabilized zirconia, and it was reported to be effective in densifying yttrium-stabilized zirconia (8). tsukuma (9) studied the effect of tio2 on the transparency of zirconia, instead of translucency. he added 10 mol% tio2 to 8 mol% yttriazirconia powder and sintered it to 1430 °c for 12 hrs and 1630 °c for 7 hrs.10the x-ray diffraction showed that tio2 dissolved in zro and formed a solid solution, but the grain size in tio2-doped zirconia was larger than in tio2 un-doped. that indicates that tio2 stimulates grain growth during sintering. it was found that the addition of tio2 provides a fairly high transmittance to the zirconia. moreover, the pressure associated with tio2-adding technique led to pore migration, which is thought to increase the transparency and the strength as well. clinical acceptable vertical marginal gap several authors have estimated maximal marginal gap (mg) values (10). after a clinical examination of more than 1000 crowns at 5-years, mclean et al (11) concluded that a marginal opening of no more than 120 μm was clinically acceptable. however, several authors of in vitro studies reported a 100μm value. there is limited literature on the precision of fit of zirconia-based crowns. previous studies have found marginal discrepancies in the range of 40-160 μm (12). marginal fit is a key criteria used in the clinical evaluation of fixed restorations. the importance of marginal fit for clinical success of ceramic complete coverage restorations inaccurate marginal fit is responsible for plaque retention, micro leakage and cement breakdown (13). the presence of large marginal discrepancies in the restoration exposes the luting agent to the oral environment. clinical studies of zirconia cad/cam fixed dental prostheses luted with resin cement have shown 10.9% and 21.7% of the fdps having secondary caries after a period of 3 and 5 years, respectively (14,15). the high rate of secondary caries has been attributed to marginal deficiencies. the larger the marginal discrepancy, the more rapid is the rate of cement dissolution. subsequently, if the cement seal fails and permits percolation of the bacteria, it could be one of the causes of pulpal inflammation and even pulpal necrosis (16). the risk of carious lesions, periodontal disease and endodontic inflammation is thus increased, and adverse consequences affecting the health of underlying abutments and optical properties may result (13,17). various studies have reported different values for precision of fit of zirconia restorations, which is attributed to differences in experimental designs and evaluation procedures. the marginal gaps ranged between 9.0 and 148.8 μm, with an average value of 73.8 μm (18). higher discrepancies have been detected at the internal gap (i.e. the internal distance measured between the coping and the abutment), ranging between 68.8 and 215 μm in the occlusal direction and between 52.3 and 192 μm in the axial direction (19). research hypotheses (1) there is no difference in vertical marginal fit between the three different brands of translucent zirconia crown restorations. (2) all the different brands of translucent zirconia crown restorations have acceptable vertical marginal gap values. h. alternative (1) there is a difference in vertical marginal fit between the three different brands of translucent zirconia crown restorations. j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 35 materials and methods a dentoform left maxillary first premolar was prepared to receive all ceramic crown (figure 1) using a high speed handpiece with air-water coolant that was adapted to the suspending arm of the modified surveyor in such a way so that the long axis of the bur was paralleled to the long axis of the ivorine tooth, the horizontal arm of the surveyor permitted vertical as well as rotational movement around the tooth. figure 1: prepared tooth the die was prepared to receive a full crown of translucent zirconia, with the following preparation features: a 90°radial shoulder finish line all around the tooth with (1 mm) depth, a total circumferential axial reduction was about (1 mm), and axial taper of 6° using a diamond bur no. (g846r). this bur was selected because it provides a shoulder finishing line (figure 2); occlusal reduction of about 1mm was performed using a diamond disk bur no. (g818) (figure 3) (20). figure 2: master die the prepared dentoform tooth was used as patterns of the master die for complete the construction of translucent zirconia crowns by the cad/cam imes-icon machine. after complete the master die preparation, remove it from the jaw base and construct acrylic base to the die to facilitate the procedure of the scanning. figure 3: zirconia preparation (17). adapt the master die at the scanning table with the gypsum base, the scanning table fixed with the 3dscanner (figure 4) by magnetic and switch on the scanner and cam computer to start the scanning as a following: figure 4: 3d scan of imes-icor system. 1-insert the information of the case as: (patient name, technician name, address, and dentist name) and save the case, and name the type of the crown (full anatomy crown) with minimum thickness 0.6mm. j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 36 figure 5: full 3d scan of master die in monitor. 2use 3dscan (imes-icor) press scanning icon to start the 2dscanning to determine the position of the crown, and then continue with the 3dscanning, the 3dscanner will tack multipicture and then press match iconto get the 3d picture of the master die. three-dimensional images were displayed on the computer monitor (figure 5). 3-desgin of the crown by press the design icon to open the design window and start the designing of full zirconia crown, the first step determined the finishing line, the crown done with the following features a minimum wall thickness of the core (1mm) and cement gap should have 0.05um thickness, the cement space started at 0.25mm from the finishing line, after complete the design of the crown copy it as a stl file and send it to the cam computer to amount the design crown in to the translucent zirconia blank (figure 6), the crown fixed in to the blank by three connector and than calculate the crown to the milling computer. figure 6: full anatomy crown in cad computer. the milling computer that was connected to the milling machine will receive the calculated crown from the cam computer for crown milling, at the same manner copy (15) stl files for three groups, (5) stl files for every group, at the end result will obtain five translucent zirconia crowns for each group. translucent zirconia crowns have a one 3d scanning and one design and then the complete designed crown stl file copied (15) stl files so we have a standardizes in 3d scanning, designing, and thickness of the crowns. the crowns that were milled separated from the blank by grinned the connecter with micro motor machine by using fisher bur. coloring and sintering all the crowns apply color agent (whitepeaks monolith color paint on: germany) to obtain the natural color to the crowns. sintering was carried out in the (ht-s mv mihmvogt-germany) (figure 7) high temperature furnace the sintering temperature and sintering program according to the manufacture instruction. figure 7: sintering oven (ht-s mv mihmvogt-germany). measurement of the marginal gap marginal gaps along vertical planes were measured at four surfaces on the margin at the midpoint of mesial, distal, buccal and palatal surfaces of all the dies seated on the master die using a light microscope. a screw loaded holding device following thiab and zakaria (21) was used during measurements in order to maintain a seating pressure of (13.4n) (22) between the all-ceramic crown and the master die during measurements calculation for this purpose (figure 8). the marginal gap of the coping was determined by measuring the vertical marginal gap between the margin of the die and the margin j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 37 of the coping, the measurements were made on indentation area that were done on the four surfaces of the die (labial, mesial, palatal and lingual) below the margin of the preparation in order that the measurement could be made at the same point on each aspect at each time (lombardas) (23) this was achieved by using a light microscope provided with a digital camera in the eye lens and connected with the computer. figure 8: master die with crown in the holding device. the microscope was calibrated to 0.001mm (1um) at magnification 100x and the measurement were done by placing the sample on the microscope stage which was adjusted until the image of the marginal area was display clearly on the computer monitor, and the digital image of the gaps were then captured, a millimeter calibration was used for each group session at the same magnification and referenced for calibration. the image was treated with program (image j) which was used to measure the vertical marginal gap between the copy and master die, the program (image j) was used to measure the value in a pixels mark by drawing a line between the finishing line on the die and the copy margin line. all digital readings were recorded and converted to (um) by a magnification factor (the length of a radiographic, photographic, or microscopic image divided by the object length) (24). forty measurements were continued for every group two measurements for all the four surfaces (mesial, palatal, distal, and buccal) of each sample, of each subgroup in the same manner. the same investigator performed all measurements with the assistance of an engineer (23,25) to be ensure the accuracy and to overcome any faulty in reading, measurements were done at 4 times repeatedly (27). the marginal discrepancy value of each coping was the arithmetic mean of these 4 measurements on the four surfaces. statistical analyses the spss software package was used to perform the statistical analysis. descriptive statistics were computed for marginal gaps. statistical methods were used in order to analyze and assess the results which include: adescriptive statistics: 1statistical tables. 2standard deviation “sd”. 3standard errors “se”. 4maximum value. 5minimum value. 6arithmetic mean. 7graphical presentation by (bar-charts). b-inferential statistics: 1-one-way anova (analysis of variance) test was carried out to see if there were any significant differences among the means of groups. 2-lsd (least significant difference) test was carried out to examine the source of differences. samples grouping: the (30) copies of stl files were divided into three groups according to the grand zirconia blanks (figure 9): 1group (1) imes-icor. 2group (2) whitepeaks. 3group (3) dentaldirect. figure 9: groups distribution of translucent zirconia blanks. j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 38 results a total of 60 images (3 groups, 5 crowns per group, 8 sites per crown) were measured. the results of the measurements, along with the results of the statistical analysis, are summarized in (table 1) and graphically presented in (figure 10). the overall mean vertical gap measurement for the whitepeaks crowns was (105.42 ± 7) μm, which was significantly higher than the two overall mean gap measured for the imes-icor crowns (59.3 ± 4) μm and dental direct crowns (54.5 ± 4.9) μm, the dental direct crowns which was lowers overall mean vertical gap measurement. 0 20 40 60 80 100 120 140 whitepex imes icor dental direct figure 10: charts of the results of marginal gap measurements table 1: descriptive statistics of vertical marginal gap measurements (μm) groups n mean (μm) s.d. s.e. min. max. whitepeaks 5 105.4250 15.783847.05875 86.00120.63 imes icor 5 59.3000 8.97636 4.01435 51.38 69.25 dental direct 5 54.5000 11.055264.94406 38.88 68.88 total 15 73.0750 26.341466.80133 38.88120.63 to spot whether the variation in the mean value at three groups, was statistically significant or not, one way (anova) test was functional in (table 2). one-way anova for translucent crowns milling machine groups (white peaks, imes-icor and dental direct). table 2: one wayanova for translucent crowns milling machine groups (whitepeaks, imes icor and dental direct) sum of squares df mean square f sig. between groups 7906.519 2 3953.259 26.243.000within groups 1807.694 12 150.641 total 9714.213 14 hs: p<0.01(highly significant) in table (2), it was revealed that the difference in marginal gap mean values among three groups (whitepeaks, imes-icor and dental direct) was statistically highly significant. additional analysis among three groups was performed using lsd test to examine the resource of the difference between the groups (whitepeaks, imes-icor and dental direct). this lsd test results show that there is highly significant difference between (whitepeaks) and (imes-icor), while there is no significant difference between (imes-icor) and (dental direct), and between (whitepeaks) and (dental direct) there is highly significant difference as shown in (table 3) and (figure 11). j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 39 table 3: lsd test between the three groups (whitepeaks, imes-icor and dental direct) groups mean difference sig. whitepeaks imes-icor 46.12500 * .000 dental direct 50.92500* .000 imes-icor whitepeaks -46.12500*.000 dental direct 4.80000 .548 dental direct whitepeaks -50.92500*.000 imes icor -4.80000.548 this lsd test showed highly significant differences in the marginal gap values between the whitepeaks and the (imes icor, dental direct), showed non-significant differences in the marginal gap values between the imes icor and dental direct and this was clearly shown in (figure 12-14). figure 11: lsd test between (whitepeaks, imes-icor and dental direct) whitepeaks imes-icor dental direct *-----------highly significant-------------------* *---------------------highly significant------------------------* *---------non significant----------* figure 12: enlarged photo of marginal gap figure 13: enlarged photo of marginal gap of of the whitepeaks the imes icor figure 14: enlarged photo of marginal gap of the dental direct discussion crown marginal fit is critical for success of the restoration; crowns with poor fit (marginal gap) are prone to failure due to micro-leakage, cement dissolution, and dental caries. in this study, the fit of crowns was assessed based on the vertical gap measurement that was selected as the most critical factor of marginal gap (mg) while being the least susceptible to manipulation post-fabrication, as j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 40 indicated by holmes et al (27) in this in vitro study. an in vitro study was conducted to examine marginal adaptation and fracture strength of single crowns made of different materials, the three groups of translucent yttrium oxide-stabilized zirconium dioxide that was milled with the cad/cam imes-icor systems that show significant difference between groups, the whitepeaks crowns show mean marginal gap (105.4 μm) was followed by the imes-icor crowns mean marginal gap (59.3 μm) and than the dental direct crowns mean marginal gap (54.5 μm) which all demonstrated acceptable marginal gaps according to many findings (28-35) who suggested that 120 μm should be the highest limit for clinically acceptable marginal discrepancies. the justifying of the present findings of the study, the methods in all the steps and measurements has a perfect standardized in between the groups, due to throughout methods steps have one master die, one 3d scanning, one designing of the crown, and the end result to have the stl file this file copied 15 time equal the crowns groups, so the non effect of the fabrication procedure of the three brands of zirconia blanks showed a large variation in marginal gap values among them due to difference in their procedures of manufacture, partial sintering, and measuring of thermal shrinkage therefore the standardized fabrication technique of methods could be obtained. the most critical factors that effect in the vertical marginal gap is the thermal dimensional changes pre-sintering and post-sintering, the presintered zirconia blank have a number that was set in the software during designing of the crown that represent the volume of sintering shrinkage, so that the balance between the enlarged machining of the pre sintered zirconia block and the shrinkage occurring during the sintering process is highly effect in the fitting of the crowns. for example when the zirconia blank has number (1,224) this number indicate that the presintering crown larger than the sintering crown in 1,224 times. the enlarged machining of the pre sintered ytzp blank may be inadequate to compensate for the shrinkage occurring after sintering of the ytzp blank milling procedure such as the accuracy in the cad-cam system. the creating of an enlarged during designing of the framework before sintering y-tzp blank and milling, to compensate the account shrinkage that associated with sintering to achieve the definitive fit of restoration with its final strength (36). this clinical study demonstrated that it was possible to fabricate cad-cam zirconia single crowns with satisfactory accuracy. (1) there is difference in vertical marginal fit between the three different brands of translucent zirconia crown restorations. (2) all the different brands of translucent zirconia crown restorations have acceptable vertical marginal gap values. references 1. goodacre cj, bernal g, rungcharassaeng k, kan jy. clinical complications in fixed prosthodontics. j prosthet dent 2003; 90(1): 31-41. 2. larsson c, vult von steyern p, sunzel b, nilner k. all-ceramic twoto five-unit implant-supported reconstructions. a randomized, prospective clinical trial. swed dent j 2006; 30(2): 45-53. 3. rosenblum ma, schulman, a. a review of allceramic restorations. j am dent assoc 1997; 128(3): 297-307. 4. helmer jd, driskell t. research on bioceramics.symposium on use of ceramics as surgical implants. clemson university, south carolina; 1969. 5. piconi c, maccauro g. zirconia as a ceramic biomaterial. biomaterials 1999; 20(1): 1-25. 6. piwowarczyk a, ottl p, lauer hc, kuretzky t. a clinical report and overview of scientific studies and clinical procedures conducted on the 3m espe lava all-ceramic system. j prosthodont 2005; 14(1): 3945. 7. giordano r, mclaren ea. ceramics overview: classification by microstructure and processing methods. comp end continue educ dent 2010; 31(9): 682-4. 8. noguchi t. advance in high temperature chemistry 2. new york: academic press; 1967. pp.274. 9. tsukuma k. transparent titania-yttria-zirconia ceramics. j materials sci letter 1986(5):1143-4. 10. mclean jw. polycarboxylate cements. five years’ experience in general practice. br dent j 1972; 132: 915. 11. mclean jw, von fraunhofer ja. the estimation of cement film thickness by an in vivo technique. br dent j 1971; 131: 107-11. 12. hung sh, hung ks, eick jd, chappell rp. marginal fit of porcelain fused-to-metal and two types of ceramic crown. j prosthet dent 1990; 63: 26-31. 13. felton da, kanoy be, bayne sc, wirthman gp. effect of in vivo crown margin discrepancies on periodontal health. j prosthet dent 1991; 65: 357-64. 14. sailer i, fehr a, filser f, gauckler ij, lüthy h, h.mmerle ch. five-year clinical results of zirconia frameworks for posterior fixed partial dentures. int j prosthodont 2007; 20: 383-8. 15. sailer i, fehr a, filser f, lüthy h, gauckler ij, sch.rer p, et al. prospective clinical study of zirconia posterior fixed partial dentures: 3-year follow-up. quintessence int 2006; 37: 685-93. 16. goldman m, laosonthorn p, white rr. microleakage--full crowns and the dental pulp. j endod 1992; 18: 473-5. 17. manicone pf, rossi iommetti p, raffaelli l, paolantonio m, rossi g, berardi d, et al. biological considerations on the use of zirconia for dental devices. int j immunopathol pharmacol 2007; 20: 9j bagh college dentistry vol. 29(2), june 2017 a comparison of restorative dentistry 41 12. 18. reich s, wichmann m, nkenke e, proeschel p. clinical fit of all-ceramic three-unit fixed partial dentures, generated with three different cad/cam systems. eur j oral sci 2005; 113:174– 9. 19. 19.luthy h, filser f, loeffel o, schumacher m, gauckler lj, hammerle ch. strength and reliability of four-unit all-ceramic posterior bridges. dent mater 2005; 21:930– 7. 20. penwadee l, edwin k, gerard j ch, markus b b. comparison of marginal fit between all-porcelain margin versus alumina-supported margin on procera r alumina crowns, j prosthodont 2009; 18: 162-6. 21. thiab ss, zakaria mr. the evaluation of vertical marginal discrepancy induced by using as cast and as received base metal alloys with different mixing ratios for the construction of porcelain fused to metal copings. alrafidain dent j 2004; 4(1): 10-9. 22. subhy ag, zakaria mr. evaluation of the effects of an iraqi phosphate bonded investment and two commercial types on the marginal fitness of porcelainfused-to-metal copings. mustansiria dent j 2005; 2(2): 183-93. 23. lombardas p, carbunaru a, mcalarney me, toothaker rw. dimensional accuracy of castings produced with ringless and metal ring investment systems. j prosthet dent 2000; 84(1): 27-31. 24. holden j e, goldstein g r, hittelman e l, clark e a, comparison of the marginal fit of pressble ceramic to metal ceramic restorations j prosthodont 2009; 18 645-8. 25. tjan ahl, castelnuovo j, sshiotsu g. marginal fidelity of crown fabrication from six proprietary provisional materials. j prosthet dent 1997; 77(5): 482-5. 26. groten m, axmann d, probster l, weber h. determination of the minimum number of marginal gap measurements required for practical in vitro testing. j prosthet dent 2000; 83(1): 40-9. 27. holmes jr, bayne sc, holland ga, sulik wd. considerations in measurement of marginal fit. the journal of prosthetic dentistry 1989; 62: 405-8. 28. christensen gj. marginal fit of gold inlay castings. j prosthet dent 1966;16(2): 297-305 29. mclean jw, von fraunhofer ja. the estimation of cement film thickness by an in vivo technique. br dent j 1971; 131: 107-11. 30. suarez mj, gonzalez de villaumbrosia p, pradies g, l. lozano jf. comparison of the marginal fit of proceraline ceram crowns with two finish lines. int j prosthodont 2003; 16: 229-32. 31. wolfart s, wegner sm, al-halabi a, kern m. clinical evaluation of marginal fit of a new experimental all-ceramic system before and after cementation. int j prosthodont 2003; 16: 587-92. 32. quintas af, oliveira f, bottino ma. vertical marginal discrepancy of ceramic copings with different ceramic materials, finish lines, and luting agents: an in vitro evaluation. j prosthet dent 2004; 92: 250-7. 33. bindl a, mormann wh. an up to 5-year clinical evaluation of posterior inceram cad/cam core crowns. int j prosthodont 2002; 15(5): 451-6. 34. sailer i, feher a, filser g, gauckler lj, luthy h, hammerle ch. five year clinical results of zirconia frameworks for posterior fixed partial dentures. int j prosthodont 2007; 20: 383-8. 35. iwai t, komine f, kobayashi k, saito a, matsumura h. influence of convergence angle and cement space on adaptation of zirconium dioxide ceramic copings. acta odontol scand 2008; 66: 214-8. 36. strub jr, rekow ed, witkowski s. computer-aided design and fabrication of dental restorations: current systems and future possibilities. j am dent assoc 2006; 137:1289-96. j bagh college dentistry vol. 28(4), december 2016 dental caries and pedodontics, orthodontics and preventive dentistry 149 dental caries and treatment needs among kindergarten children in al-basrah governorate/iraq sarah w. al-abbasi, b.d.s. (a) nada j.m.h. radhi, b.d.s, m.sc., ph.d. (b) abstract background: dental caries is a disease occurs in the world in both developed and developing countries, it is still widespread among children and it can be controlled but not eliminated , most of tooth loss occurs due to dental caries and its complications. the aim of this study was to estimate the occurrence, and severity of dental caries and treatment needs among kindergarten children in al-basrah governorate. materials and methods: the sample consisted of 1000 kindergarten children at age of 4-5 years old (445 boys and 555 girls) from urban areas in al-basrah city. diagnosis and recording of dental caries and treatment needs were done according to the criteria of who (1987). results: the percentage of dental caries was (80.8%) of the total sample. the dmfs value was higher among boys compared to girls with no statistically significant difference (p>0.05).the dmfs value among 5 years old children were found to be higher than children aged 4 years with statistically highly significant difference (p< 0.01). the higher percentage of examined children was in need of one surface filling (71.6%) followed by those in need of preventive or fissure sealant (61.3%). conclusions: a study revealed a high prevalence of dental caries was found among kindergarten children in albasrah governorate, thus there is a need for preventive programs among those children. keywords: dental caries, treatment needs, oral health, kindergarten children. (j bagh coll dentistry 2016; 28(4):149152) introduction dental caries is a common oral disease in children and the most important dental health problem in developing countries (1). the disease is the results of interplay of several factors including host factors (susceptible tooth and saliva), dietary sugar and cariogenic bacteria in the presence of sufficient time (2). several iraqi studies recorded a high prevalence and severity of dental caries among preschool children in different geographical locations (3-11). treatment of dental caries has been identified as critical to both oral and general health (12). the type of treatment needed tend to become more complicated as well as need for treatment increased with age (3,13). this study was designed to evaluate the occurrence and severity of dental caries, also to measure dental treatment needs for dental caries among kindergarten children in al-basrah governorate. materials and methods the sample included kindergarten children at age of 4-5 years old from urban areas in albasrah governorate. the sample consisted of 1000 child, 445 boys and 555 girls (kindergartens and children were selected randomly). (a) m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (b) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. permission was obtained from directorate of education of al-basrah governorate in order to meet individual with no obligation; also a special consent prepared and distributed to the parents to obtain permission for including their children in the study and to have their full cooperation. diagnosis and recording of dental caries as well as treatment needs was assessed according to the criteria described by who (14). clinical examination was conducted using plane mouth mirror and dental probe. analysis and processing of the data were carried out using statistical package for social sciences (spss) version 21, the non-parametric tests were used for the non normally distributed variables represented by mann-whitney test to reveal the significance of difference in median and mean rank. p-values less than 0.05 were considered as statistically significant, while pvalues less than 0.01 were recorded as a highly significant. results table (1) shows the distribution of the total sample by age and gender. the sample was consisted of boys and girls as a higher percentage of girls was noticed compared to boys. the percentage of dental caries in the present study was (80.8%) among total sample. mean rank values of ds, ms, fs and dmfs among children by age and gender are illustrated in the table (2). in this study boys were found to have higher dmfs mean rank value than girls, but the difference was found to be no statistically j bagh college dentistry vol. 28(4), december 2016 dental caries and pedodontics, orthodontics and preventive dentistry 150 significant (p>0.05). concerning age the data of present study found that the mean rank value of dmfs among 5 years children was higher than children aged 4years; the difference was statistically highly significant (z=-3.643, mannwhitney=0.001, p<0.01). however for the components of dmfs index the results illustrated that for total sample the decay teeth (ds) was had a higher mean rank value for boys than girls with no statistically significant difference (p>0.05). regarding age, the mean rank value of ds at age of four years was found to be lower than children aged 5 years, the difference was statistically highly significant (z=-3.302, mannwhitney=0.001, p<0.01). concerning age and gender the differences of the extracted teeth by caries (ms) and filled surface (fs) due to caries were statistically not significant (p>0.05) except (ms) regarding age with statistically significant difference (z=-2.545, mann-whitney=0.011, p<0.05). the percentages of children with each category of dental treatment needs by gender are illustrated in figure (1). the higher percentages of children were found to be in need of one surface filling followed by those in need of preventive or fissure sealant, two or more surface filling and pulp care and restoration while the lower percentage showed among those in need of extraction. table 1: the distribution of total sample by age and gender table 2: caries-experience (median, mean rank of ds, ms, fs, dmfs) among children by age and gender. age 4 5 total mannwhitney test pvalue gender boys girls total boys girls total boys girls ds median 4 4 4 7 6 6 6 5 0.001 <0.01** mean rank 252.2 254.4 470.8 258.0 237.6 530.9 513.9 489.7 ms median 0 0 0 0 0 0 0 0 0.011 <0.05* mean rank 252.2 254.4 490.1 248.8 246.3 511.2 501.6 499.6 fs median 0 0 0 0 0 0 0 0 ns mean rank 253.0 253.8 500.5 248.0 247.0 500.5 500.6 500.4 dmfs median 4 5 5 8 6 7 6 5 0.001 <0.01** mean rank 252.2 254.4 467.8 259.0 236.8 534.0 515.7 488.3 * significant ** highly significant figure 1: distribution of children according to the type of the treatment need required by gender age (year) gender boys girls total no. % no. % no. % 4 206 20.6 300 30 506 50.6 5 239 23.9 255 25.5 494 49.4 total 445 44.5 555 55.5 1000 100 j bagh college dentistry vol. 28(4), december 2016 dental caries and pedodontics, orthodontics and preventive dentistry 151 discussion this study was achieved in al-basrah governorate because there was no previous epidemiological study concerning this age carried out in this governorate so this study's results can be considered as base line data for comparison with other studies in iraqi governorates and different parts of the world. in this study the percentage of dental caries was found to be (80.8%) for 4-5 yearsold kindergarten children. the high caries prevalence recorded by this study may partly be attributed to variances in the environmental condition as lower fluoride level in drinking water in iraq, the concentration of fluoride in communal water supply in different governorates in iraq is ranging from 0.120.22 ppm (3). however when comparing this result with previous iraqistudies this percentage was higher than that reported by many studies (3,4,6,11,15-18) and was lower than that reported by other iraqi studies (10, 19, 20). in general, variation in caries experience between this study and other iraqi studies may be partially attributed to variation in dietary habits, oral hygiene measures as well as dental health services between governorates; however this may need further studies to confirm this observation. concerning gender differences, boys were found to have higher dmfs mean rank value than girls with no statistically significant difference, this result is similar to that recorded by some iraqi studies (9, 11, 17, 20-22) for the same age group, and this may be related to the earlier shedding ofdeciduous teeth in females compared to males. according to age, in this study caries experience was discovered to be increase with age, it was higher among 5 years than 4 years children with highly significant difference, this result is similar to that reported by iraqi studies (3,6,10,11,13,20,23-26). this may be related to accumulative and irreversible nature of dental caries. this study showed that the (ds) fraction was higher than (ms) and (fs) components of dmfs index, which is an indication of a poor dental treatment. the (ms) fraction was higher than (fs) fraction, which means that even if treatment is present; it is directed toward extraction rather than restoration. this result is in agreement with other iraqi studies (5,10,11,20). most of children in this study were in need of one surface filling (71.6%), that is to say in need for restorative treatment to prevent progression of dental caries, followed by preventive or fissure sealant (61.3%), that reflecting these were in need of recall for regular visits and prophylactic application of fluoride therapy and fissure sealant to prevent initiation of dental caries. this finding is in agreement with many iraqi studies (3,18,27) where the majority of children were in need of restoration. the increase in the prevalence of dental caries among kindergarten children in al-basrah city with the increase in dental treatment need indicate the need for either a public or school preventive programs for those children, involving dental health education and improvement of dental knowledge and attitude towards both oral hygiene and proper nutrition. references 1. khan ma, khan d, nawaz r. prevalence pattern of dental caries in permanent teeth among school children of peshawar city. kjms 2011; 3: 253. 2. peter s. essentials of preventive and communitydentistry. 2nd ed. new delhi: darya ganj; 2004. pp.241 – 2. 3. al-azawi l. oral health status and treatment needs among iraqi five-year old kindergarten children and fifteen-year old students (a national survey). ph.d. thesis, college of dentistry, university of baghdad, 2000. 4. al-eissa d. oral health status of preschool children aged 3-5 years old and its relation to their socioeconomic status, and parent dental knowledge, behavior and attitude in two different social areas in baghdad city. a master thesis, college of dentistry, university of baghdad, 2004. 5. ibrahim i, salih b. current prevalence of dental caries in iraqi preschool children. a comparison to national and international studies. j bagh coll dentistry 2006; 18(1): 72-5. 6. jabber wm. oral health status in relation to nutritional status among kindergarten children 4-5 years in alkut city/ iraq. a master thesis, college of dentistry, university of baghdad, 2008. 7. hassan z. the effect of nutritional status on dental health, salivary physiochemical characteristics and odontometric measurement among five years old kindergarten children and fifteen years old students. ph.d. thesis, college of dentistry, university of baghdad, 2010. 8. radhi n. salivary vitamins and total proteins, in relation to caries-experience and gingival health, according to nutritional status of a group of five-year old children. j bagh college dentistry 2012; 24(3):129-36. 9. al-mendalawi m, karam n. risk factors associated with deciduous tooth decay in iraqi preschool children. j avic med 2014; 4(1): 5-8. 10. shubber s. oral health status among kindergarten children in relation to socioeconomic status in alnajaf governorate-iraq. a master thesis, college of dentistry, university of baghdad, 2014. 11. suhail i. oral health status in relation to nutritional status among kindergarten children in al-ramadi city/iraq. a master thesis, college of dentistry, university of baghdad, 2014. 12. gopinath k, barathi k, kannan p. assessment of treatment of dental caries in school children of tamil nadu (india). j ind soc pedo prev dent 1999; 17(1): 9-14. j bagh college dentistry vol. 28(4), december 2016 dental caries and pedodontics, orthodontics and preventive dentistry 152 13. el-samarrai sk. oral health status and treatment needs among preschool children. a master thesis submitted to college of dentistry, university of baghdad, 1989. 14. world health organization. oral health survey, basic methods. 3rd ed. geneva, 1987. 15. nazhat ny, yagot kh, kuder sa. prevalence and pattern of caries among nursery school children in iraq. j dent res 1986; 65:47-75. 16. al-weheb am. dental caries prevalence among 4 year old children. iraq dent j 1998; 23: 67-76. 17. al-obaidi w. dental caries experience among kindergarten's children in baghdad iraq. iraqi dent j 2002; 29: 269-76. 18. hassan z, al-taai a. pattern, severity of dental caries and treatment needs among five years kindergarten children in baghdad iraq. iraqi j comm medi 2006; 19(3): 280-5. 19. al-ubadi a. the prevalence of streptococcus mutans biotypes among preschool children. a master thesis, college of dentistry, university of baghdad, 1993. 20. al-obaidi w. oral health status in relation to nutritional status among kindergarten children in baghdad. iraq. a master thesis, college of dentistry, university of baghdad, 1995. 21. al-weheb am. dietary habits and its relation to caries experience among preschool children in baghdad. a master thesis, college of dentistry, university of baghdad, 1991. 22. chaloob e, qasim a. nutritional status in relation to oral health status among patients attending dental hospital. j baghcoll dent jun 2013; 25(1):114-9. 23. ahmed zs. oral health status and treatment needs among institutionalized children and adolescents in comparison to school children and adolescents in iraq. a master thesis, college of dentistry, university of baghdad, 2002. 24. diab bs. severity of dental caries among 3-6 years old children in al-edwania village, baghdad. j bagh coll dentistry 2006; 18(1): 69-71. 25. murad no. dental caries, gingival health condition and enamel defect in relation to nutritional status among kindergarten children in sulaimania city. a master thesis, college of dentistry, sulaimania university, 2007. 26. hassan r, abaas m. prevalence of dental caries in children attended pedodontic dental clinic al mustansiria collage of dentistry. j must coll dent 2011; 8(3):276-280. 27. al-ghalebi s. oral health status and treatment need in relation to nutritional status among 9-10 year-old school children in nassirya city/iraq. a master thesis, college of dentistry, university of baghdad, 2011. ghufran final.doc j bagh college dentistry vol. 26(3), september 2014 oral hygiene practices oral diagnosis 58 oral hygiene practices and self-perceived halitosis among dental students ghufran a. hasan, b.d.s., m.sc. (1) abstract background: halitosis represents a common dental condition, although sufferers are often not conscious of it. it is common among humans around the world and is usually caused by an accumulation of bacteria in the mouth as a result of gum disease, food, or plaque. this study aimed to determine the prevalence of oral hygiene practices, smoking habits and halitosis among undergraduate dental students and correlate the oral hygiene practices, oral health conditions to the prevalence of self perceived oral malodor. materials and methods: clinical examination of 250 dental students and a self-administered questionnaire were included in this study. a questionnaire was developed to assess the self-reported perception of oral breath, awareness of bad breath, timing of bad breath, oral hygiene practices, caries and bleeding gums, dryness of the mouth, smoking and tongue coating. results: the results indicated that female students had better oral hygiene practices. significantly less self-reported oral bad breath (p = 0.000) was found in female dental students (40%) as compared to male (70%). it was found that smoking had statistically highly significant correlation with halitosis (p = 0.000). presence of other oral conditions such as dental caries and filled carious lesions also showed higher prevalence of halitosis in dental students. conclusion oral hygiene practices and oral health conditions are very important factors in halitosis. females exhibited better oral hygiene practices and less prevalence of halitosis as compared to male students. key words: halitosis, oral hygiene, oral malodor, smoking. (j bagh coll dentistry 2014; 26(3):58-62) introduction halitosis is the general term used to describe any disagreeable odor in expired air regardless of whether the odorous substances originate from oral or non-oral sources. other names used are fetor ex ore, fetor oris, bad or foul breath, breath malodor and oral malodor (1). loesche and kazor (2) had demonstrated that the mouth is the origin for the majority of halitosis. halitosis is a common complaint of both genders. it occurs worldwide and has a multifactorial etiology (3). in vitro and in vivo studies demonstrated the ability of putative periodontal pathogens and products of inflammation to produce volatile odoriferous compounds (4,5). therefore, the presence of periodontal inflammation needs to be considered i n t h e m a n a g e m e n t o f halitosis. tongue coating, including bacteria, desquamated cells, and saliva, among others, is one of the important etiological factors of halitosis. a study demonstrated that tongue coating was associated with halitosis in more than 60% of 2000 patients of a breath clinic, whether present alone, or with periodontal inflammation (6). t he int ensit y of b a d br ea th is significantly associated with the level of volatile sulfur compounds (vscs) in the oral cavity (7). increased product ion of vsc may represent a furt her mecha nism of incr ea s ed suscept ibility t o periodontitis in smokers and (1)assistant lecturer. department of oral diagnosis. college of dentistry, university of baghdad. also help explain the reported association between smoking and halitosis. the percentage of sites per subject with high levels of sulphides detected in moderate and deep periodontal pockets was found to be significantly higher in smoker s, compared with non-smokers (8). the saliva performs essential roles in protection of oral tissues, lubrication and assistance in swallowing, potentiating of taste, and elimination of the food bolus. a reduction in salivary flow has a negative effect on the self-cleaning of the mouth and can generate odoriferous volatile compounds (3). according to the american dental association, 50% of the adult population has suffered from an occasional oral malodor disorder, while 25% appear to have a chronic problem. however, there are other extrinsic causes e.g. smoking, alcohol, bad diet and socio-demo graphic factors (9). tooth brushing and dental flossing constitute the most common self-care behaviors for the preservation of human oral health (10). other predisposing factors causing halitosis included poor oral hygiene, gingival and periodontal disease, disorders of the oral mucosa, reduced salivary flow and the wearing of dental appliances (11-15). the objectives of the study were to determine the prevalence of oral hygiene practices, smoking habits and their relations with halitosis among undergraduate dental students materials and methods a questionnaire based study was carried out at diagnostic clinic of oral diagnosis department / college of dentistry/ university of baghdad j bagh college dentistry vol. 26(3), september 2014 oral hygiene practices oral diagnosis 59 between 2011 and 2013). the final sample consisted of 250 (150 females and 100 males) dental students. those students were examined clinically by the author for the presence of dental caries, bleeding on probing, dryness of the mouth and tongue coating. a self-administered questionnaire was developed to assess the prevalence of oral hygiene habits including brushing, flossing, use of mouthwash, self-perception of oral health, awareness of bad breath (by asking student: are you have bad breathing and how do you know you have bad breathing, someone told you or you just know), timing of bad breath, asking the student if he/she noticed bleeding when you brush your teeth or in saliva when you spit), dryness of mouth (by visual examination to notice if there was a dry tongue and cracked lips or by asking student if there was a sticky or dry feeling in the mouth or trouble chewing or tasting), smoking habits, and coating over tongue (by visual examination to notice a coating area or discoloration on tongue's dorsum). the questionnaire was made by reviewing the literature, and making modifications according to local culture oral hygiene practices and habits (16). questionnaire do you brush your teeth every day? do you brush once daily? do you brush twice daily? do you brush three times daily? do you brush more than three times daily? do you change your toothbrush every 3 months? do you change your toothbrush every 6 months? do you change your toothbrush after 6 months? are you using a dental floss? are you using a mouth wash? are you smoker? at what time of day is your breath worst: after waking up? when hungry? when thirsty? while talking with other people? all day? statistical analysis the data was entered into statistical package for social sciences (spss) version 19.0 and was utilized for data analysis. chi-square test was used detect the genders difference regarding the halitosis and to investigate the relation between the halitosis and other parameters. the significance level (p value) was set at 0.05. results two hundred and fifty students filled the questionnaire and responded. the results indicated the presence of high significant genders difference with males had higher percentage than females (table 1). table 1: the prevalence of self-perceived halitosis and gender difference among dental students halitosis males (n=100) females (n=150) total (n=250) genders difference no. % no. % no. % x2 p-value present 70 70 60 40 130 52 21.635 0.000 absent 30 30 90 60 120 84 the majority of students (70% of males and 80% of females) experienced bad breath after wake up, while the equal percentage in males (5%) of bad breath occurred when they hungry and while talking with other people and increased to 10 % when thirsty and in all day. females demonstrated equal percentages of halitosis (4.3%) when they were thirsty and all day and this percentage increased up to 10 % while talking with other people. generally, there was nonsignificant gender difference (table 2). table 2: the timing of self perceived bad breath during the day timing of self-perceived bad breath during the day males (n=100) females (n=150) total (n=250) genders difference no. % no. % no. % x2 p-value after wake up 42 70 56 80 98 75.4 5.865 0.209 when hungry 3 5 1 1.4 4 3.1 when thirsty 6 10 3 4.3 9 6.9 while talking with other people 3 5 7 10 10 7.7 all day 6 10 3 4.3 9 6.9 j bagh college dentistry vol. 26(3), september 2014 oral hygiene practices oral diagnosis 60 regarding the relation between the halitosis and the frequency of brushing, the results revealed that there was highly significant relation between the increase of the frequency of brushing and absence of halitosis (table 3). table 3: the halitosis presence to brushing brushing halitosis relation present absent x2 p-value no. % no. % daily brushing habit (250 students) 130 52 120 48 35.91 0.000 brushing once daily (64 students) 50 78.1 14 21.9 brushing twice daily (140 students) 70 50 70 50 brushing three times daily (40 students) 10 25 30 75 brushing more than three times daily (6 students) 0 0 6 100 relating the frequency of changing the tooth brush with halitosis revealed high significant relation being higher percentage of absence of halitosis if the student changed his/her tooth brush within 3 months (table 4). on the other hand, 100 student used dental floss and mouth wash and reported no halitosis and this confirmed by the significant relation between the use of dental floss and mouth wash with the absence of halitosis (table 5). table 4: the relation between halitosis and the frequency of changing tooth brush frequency of changing the brush halitosis relation present absent x2 p-value no. % no. % changing brush within 3 months (100 students) 40 40 60 60 11.396 0.003 changing brush within 6 months (90 students) 50 55.6 40 44.4 changing brush after 6 months (60 students) 40 66.7 20 33.3 table 5: the relation between halitosis and the use of dental floss and mouth wash use of dental floss and mouth wash halitosis relation present absent x2 p-value no. % no. % use of dental floss (40 students) 20 50 20 50 9.091 0.011 use of mouth wash (50 students) 25 50 25 50 use of dental floss and mouth wash (10 students) 0 0 10 100 table 6 demonstrated the relation between halitosis with other predisposing factors and the results revealed highly significant relation. generally, 45 students (90%) out of 50 smoker students reported halitosis. dry mouth ranked secondly then the carious lesion, coating over tongue, etc. table 6: the relation between halitosis and smoking, dry mouth, caries, bleeding gums and coated tongue oral hygiene practices halitosis relation present absent x2 p-value no. % no. % smoking habit (50 students) 45 90 5 10 22.607 0.000 presence of dryness of mouth (25 students) 20 80 5 20 presence of filled carious lesions (70 students) 40 57.1 30 42.9 presence of dental caries (75 students) 50 66.7 25 33.3 presence of bleeding gums (40 students) 20 50 20 50 presence of coating over the tongue (25 students) 15 60 10 40 self-reported prevalence of dryness of mouth, dental caries, bleeding gums and coating over tongue were assessed among males and females dental students. statistically, there was highly significant gender difference in the results (table7). j bagh college dentistry vol. 26(3), september 2014 oral hygiene practices oral diagnosis 61 table 7: the prevalence of selfassessed presence of dry mouth, dental caries, coating over the tongue and bleeding gums amongst dental students oral hygiene males (n=100) females (n=150) genders difference no. % no. % x2 p-value dryness of mouth n=25 15 15 10 6.7 11.42 0.009 dental caries n=70 35 35 35 23.3 bleeding gums n=40 10 10 30 20 coating over the tongue n=25 15 15 10 6.7 discussion bad breath can be a social handicap for an individual. self-perception is important for diagnosing and controlling bad breath. a recent study of united states dentists reported that chronic bad breath was diagnosed by 41% of practicing dentists in one week (17). studies conducted in sweden (18) and france (19) have also reported the prevalence of oral malodor in the population. from such studies it can be concluded that halitosis is a problem that is perceived in different cultures and societies of the world. in this study the health care professionals such as dental students were studied for the prevalence of halitosis by correlating it to oral hygiene practices being followed by the students, the oral conditions such as dental caries, dryness of mouth, smoking, bleeding gums and coating over tongue. it had been suggested that students who brush their teeth with a frequency of more than three times daily, changed their brush within 3 months, used both dental floss and mouthwash did not reported halitosis as compared to the ones who did not follow such oral hygiene practice. the oral hygiene practices were better among the female students and also the prevalence of self reported oral malodor was less in the female dental students. these results coincide with the results of other studies (20,21). dry mouth is also highly correlated with oral malodor. in this study, almost 15% males and 10% females reported dry mouth. it has been suggested that a reduced saliva flow during sleep favors anaerobic bacterial putrefaction, giving rise to so-called “morning breath,” a transient condition which disappears after a meal (1,22). halitosis was most prominent soon after wake up in most of the individuals (75.4%) who complaint of self perceived oral malodor. this can be attributed to the reduced salivary flow at night or to the lack of brushing habit at night. females (80%) as compared to males experience halitosis after wake up. in the present study, 0.7% of females and 49% of males were smokers. a history of smoking has been implicated in decreasing olfactory sensitivity (20). it has been found that prevalence of halitosis (90%) was more in presence of smoking habit with statistically highly significant correlation (p=0.000), this result agrees with al-atrooshi and al-rawi (21) who found that smoking has been defined as an extrinsic cause of oral halitosis. suarez et al. (22) suggested oral malodor in younger generations could be ascribable mainly to tongue coat deposition. furthermore, a positive correlation between levels of vsc on the tongue’s dorsum surface and whole oral malodor has been demonstrated (23). kishi et al. (24) indicated several vsc producing bacteria have the ability to colonize on the coat of the tongue in peridontally healthy subjects. it was also suggested oral malodor could be related to not only the amount of tongue coating but also the colonization of p. gingivalis in the coating. 60% of the students who experienced tongue coating reflected the perception of bad breath. from this study, it has been concluded that female dental students maintained better oral hygiene practices than male dental students and had less prevalence of halitosis as compared to the male student population. the oral health care providers are responsible for sound oral health of the nation. they cannot be role models for their patients until they maintain good habits themselves. this can be done by greater emphasis during their undergraduate dental training could improve their oral self-care behaviors. halitosis is a reflection of poor oral health. in this study, it can be concluded that good oral hygiene habits such as using of both dental floss and mouth wash tend to decrease the prevalence of halitosis, while the presence of smoking habit tend to increase the prevalence of halitosis. references 1. tangerman a. halitosis in medicine: a review. int dent j 2002; 52(suppl 3): 201-6 2. loesche wj, kazor c. microbiology and treatment of halitosis. periodontol 2000 2002; 28: 256-79. 3. motta lj, joanna cb, carolina cg, lorena tl, sandra kb. association between halitosis and mouth breathing in children. clinics 2011; 66(6): 939-94. 4. yoneda m, masuo y, suzuki n, iwamoto t, hirofuji t. relationship between the βgalactosidase activity in saliva and parameters associated with oral malodor. j breath res 2010; j bagh college dentistry vol. 26(3), september 2014 oral hygiene practices oral diagnosis 62 4(1): 17-8. 5. salako no, philip l. comparison of the use of the halimeter and the oral chroma in the assessment of the ability of common cultivable oral anaerobic bacteria to produce malodorous volatile sulfur compounds from cysteine and methionine. med princ pract 2011; 20(1):75-9. 6. quirynen m, dadamio j, van den velde s, de smit m, dekeyser c, van tornout m, et al. characteristics of 2000 patients who visited a halitosis clinic. j clin periodontol 2009; 36(11): 970-5. 7. riggio mp, lennon a, rolph hj, hodge pj, dona lds on a, m a xwell aj . molec u la r identification of bacteria on the tongue dorsum of subjects with and without halitosis. oral dis 2008; 14: 251-8. 8. khaira n, palmer rm, wilson rf, scott da, wade wg. production of volatile sulphur compounds in diseased periodontal pockets is significantly increased in smokers. oral dis 2000; 6: 371–75. 9. weinberg ma, westphal c, froum sj, palat m. comprehensive periodontics for the dental hygienist. 2nd ed. new jersey: prentice hall; 2006. pp. 337–46. 10. bakdash b. current patterns of oral hygiene product use and practices. periodontol 2000 1995; 8: 11–14 11. koshimune s, awano s, gohara k, kurihara e, ansai t, takehara t. low salivary flow and volatile sulfur compounds in mouth air. oral surg oral med oral pathol oral radiol endod 2003: 96: 38–41. 12. outhouse tl, al-alawi r, fedorowicz z, keenan jv. tonguescraping for treating halitosis. cochrane database syst rev 2006; 19(2): cd005519. 13. porter sr, scully c. oral malodour (halitosis). bmj 2006; 333: 632–5. 14. scully c, rosenberg m. halitosis. dent update 2003: 30: 205–10. 15. yaegaki k, coil jm. examination, classification, and treatment of halitosis; clinical perspectives. j can dent assoc 2000; 5: 257–61. 16. yaegaki k, coil jm. clinical application of a questionnaire for diagnosis and treatment of halitosis. quintessence int 1999; 30: 302-6. 17. löesche wj. the effects of antimicrobial mouth rinses on oral malodor and their status relative to us food and drug administration regulations. quintessence int 1999; 30: 311-8. 18. söder b, johansson b, söder po. the relation between foetor ex ore, oral hygiene and periodontal disease. swed dent j 2000; 24: 73-82. 19. frexinos j, denis p, allemand h, allouche s, los f, bonnelye g. descriptive study of digestive functional symptoms in the french general population. gastroenterol clin biol 1998; 22: 785-91. 20. ada council on scientific affairs. oral malodour. j am dent assoc 2003; 134: 209-14. 21. al-atrooshi ba, al-rawi as. oral halitosis and oral hygiene practices among dental students. j bagh coll dent 2007; 19: 72-6. 22. suarez f, furne j, springfield j, levitt md. morning breath odor: influence of treatments on sulfur gases. j dent res 2000; 79: 1773-7. 23. morita m, wang hl. relationship between sulcular sulfide level and oral malodor in subjects with periodontal disease. j periodontol 2001; 72: 79-84. 24. kishi m, kimura s, dhare-nemoto y, kishi k, aizawa f, moriya t, et al. oral malodour and periodontopathic microorganisms in tongue coat of periodontally healthy subjects. dent jpn 2002; 38: 248. j bagh college dentistry vol. 30(3), september 2018 the impact of 40 the impact of oral health knowledge, attitude and practices (kap) of kindergarten teachers on their oral condition in al-rusafa sector/ baghdad-iraq. israa s. al-atiyah, b.d.s. (1) nada j. radhi, b.d.s., m.sc., ph.d. (2) abstract background: teachers are considered as dynamic force who take a pivotal position in any educational system. since they may play a significant role in passing the preventive information and health promotion, it is important that their own oral health knowledge, attitude, and practices conform to the professional recommendations. the aim of this study was to evaluate oral health knowledge, attitude and practices among kindergarten teachers, and their impact on teachers’ oral health condition in al-rusafa sector, baghdad, iraq. materials and methods: this cross-sectional survey was conducted among 80 kindergarten teachers. a self-administered questionnaire was distributed among these teachers. this questionnaire format contains two parts that deals with oral health knowledge, attitude and practices of teachers, and this was followed by clinical oral examination for all the teachers. simple random sampling technique was employed for the selection of the study participants. descriptive analysis was done and data was analyzed using bonferonni t-test and anova test. results: teachers demonstrated adequate but incomplete knowledge regarding oral health. more than 85.0% of teachers were aware of preventive measures to keep good oral health and knew the bad influence of neglecting the oral hygiene. about 65.0% of teachers had the awareness about dental plaque composition and its bad effects. meanwhile, 45.0% of them were aware about the signs of tooth decay, also 32.5% were aware about the benefits of regular correct brushing on the gingiva. no obvious differences were noticed regarding teachers’ dmfs, plaque and gingival indices mean values in association to the level of teachers’ knowledge, however, a positive relation were found between favorite attitude and practices and mean values of dmfs, plaque and gingival indices. conclusions: the studied kindergarten teachers demonstrated adequate but incomplete oral health knowledge with many of them adopting poor attitude and practices. there is a definite and immediate need for an integral educational program for kindergarten teachers on basic oral health knowledge and favorable practices. moreover, teachers’ healthy practices can affect their oral health condition positively. keywords: impact, oral health knowledge, attitude, practices, kindergarten teachers. (j bagh coll dentistry 2018; 30(3): 40-47) introduction teachers, in general, shape the future of country and prepare the young ones for future life. thus, they should carry on acting as role models for the children. however, they cannot assist in developing a well-informed generation, if they themselves were misinformed (1).teachers having good oral health knowledge, favorable attitude and healthy practices can play a key role in the implementation of different oral health educational and preventive programs, which aim to improve the oral health practices and status for themselves, in addition to the children (2) it is therefore important that their own oral health knowledge is accurate, and their oral health practices fits the public’s expectations (3). regarding oral health, schoolteachers can play an important role in inspiring the children to adopt healthy lifestyles as well as transmitting the (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad awareness about the causes and prevention of common oral problems (4). this can be actual only if the teachers themselves practice healthy oral hygiene and lifestyle, also have a complete and in-depth knowledge about common oral diseases and their ways of prevention. therefore, provision of oral health knowledge to the children by their teachers at the kindergarten level can prove to be more fruitful compared to the primary or secondary level because it’s the time period during which the children begin to learn basic oral hygiene practices and are most prone to dental caries (5). previous studies concerning primary schoolteachers’ knowledge and attitudes towards dental health showed that most schoolteachers had a positive attitude towards oral health as well as a fair amount of ideas about poor oral health conditions of children, and were eager to get involved in the oral health educational programs. additionally, they were keen to receive training in order to improve (1) ministry of health, baghdad, iraq j bagh college dentistry vol. 30(3), september 2018 the impact of 41 their level of acquaintance concerning oral health issues (6-9). in the present settings, no relevant literature is available regarding oral health knowledge, attitude and practices of kindergarten teachers. hence, and in regards to the above-mentioned information, there is a need to conduct a nationwide study that may be able to assess teachers’ oral health knowledge and practices, as well as to find if there is any effects between these variables and teachers’ oral condition. against this background, the study was undertaken among kindergarten teachers, with the objective of assessing their oral health knowledge, attitude and practice, and to determine their impact if anyon teachers’ oral condition. material and methods this cross-sectional survey was conducted among a sample of teachers attending public kindergartens in al-rusafa sector in baghdad-iraq. examination started at the beginning of january 2017 until the end of march 2017. official permission was obtained from the iraqi ministry of education before data collection in order to examine the selected individuals with no obligation. the sampling frame consisted of 20 public kindergartens, chosen from total 93 kindergartens throughout the use of probability sampling (computerized simple random sampling) including different areas of al-rusafa sector. total 80 teachers were drawn randomly from these 20 kindergartens to participate in this research. in this study, the main instrument for data collection was a structured self-administered questionnaire adopted from different sources like articles and research studies (10-17). this questionnaire format was introduced to kindergarten teachers in arabic language in order to evaluate their oral health knowledge, attitude and practices. this method of data collection has been tested previously, and has shown to be adequate and reliable (18, 19). this was followed by clinical oral health examination including dental examination, oral cleanliness and gingival examination for all of the participated teachers. oral cleanliness was recorded using the plaque index criteria (20). while, the gingival index (gi) by löe and silness (21) was utilized for gingival condition assessment. diagnosing the extent and severity of tooth decay were performed regarding the who criteria (1987) (22). clinical examination was done using plane mouth mirror with dental explorer. statistical analysis: data description and statistical analysis were obtained using ibmspss version 23computer software (ibm statistical package for social sciences) in association with microsoft excel. descriptive statistics were obtained, and the mean values and frequency distribution were calculated. according to kolmogorov-semirnov test for normality, the outcome quantitative variables were shown to be normally distributed. anova test was employed to analyze the data. level of significance can be tested as probability of error (p-value) thus, not significant if p> 0.05, significant if p≤ 0.05. results in regards to teachers’ knowledge, attitude and practices (kap) questionnaire, a full response rate was obtained, since all the selected teachers accept to participate in this research study. socio-demography out of 80 teachers, almost equal distribution was recorded regarding the three categories of teachers’ age group. relating to teachers’ educational status, 51.3% of them completed institutional degree, 37.5% had a college certificate, while only 11.3% had a secondary school certificate. about teaching-experience years, the majority 57.5% had more than 10 years of experience, 23.8% had less than 5 years, whereas only 18.8% had 5-10 years of experience. married teachers represented 92.5% of the total sample while single teachers were only 7.5%. teachers with children constituted 87.5% of the sample, while only 12.5% of them had no children. knowledge table 1 shows teachers’ scores regarding their oral health knowledge. results showed that more than 85.0% of teachers were aware that “it is possible to prevent oral diseases by brushing, flossing and avoiding sugar”, in addition to “neglecting oral health causes periodontal disease such as swollen and bleeding gingiva” and “bleeding during brushing is a sign of gingival disease or wrong brushing technique”. however, only 2.5% of teachers did not know about the previous statements. almost more than half of respondents had the awareness about the composition and effects of dental plaque. additionally, about two-thirds of the sample were aware about dental plaque components and effects. meanwhile, less than half of teachers were aware that gingival bleeding is not a sign of tooth decay, also growing old is not a reason for teeth loss, as j bagh college dentistry vol. 30(3), september 2018 the impact of 42 well as they knew that regular correct brushing technique can protect from gingival bleeding. the least proportion of teachers 27.5% were aware that tooth decay is infectious, however, 12.5% of them answered with “do not know”. attitude and practices as shown in table 2, teachers with the highest frequency of tooth brushing “twice or more daily” constituted the largest proportion of the study sample 67.5%. meanwhile, the largest proportion of them spend about 1 minute during brushing 55.0%, while only 16.3% of them spend less than 1 minute. results showed that most of teachers 63.8% consuming sugary snacks never or once daily, and only 2.6% eat sugary snacks more than four times a day. moreover, 55.0% of teachers thought that brushing at night is the best time for tooth brushing, followed by 26.3% of them who chose “after each meal” as the best time for brushing and 18.8% thought that it is the best to brush at morning. however, majority of teachers 71.3% visited dental clinics when sever toothache, followed by 15.0% of them went for a regular check-up “every 6-12 months”. moving to the reasons for usual dental clinic visits, “dental pain” was the main reason for the majority of teachers 80.0%. although, minority of them showed that “regular check-up time”, “esthetic” and “improving function” were the reasons for visiting dental clinic, and they were 3.8%, 7.5% and 8.8% respectively. relating to the reasons behind not/ dislike visiting the dentist, the larger part of teachers 61.3% reported that the “fear of needle and/or drilling” was the main reason behind their negative attitude towards visiting the dentist. the “high cost” was the second popular reason among the teachers, as 42.5% of them hate going to the dentist because of this. only 13.8% and 3.8% of teachers revealed that there is “no time” and “no clinics nearby”, respectively, were the reasons for dislike visiting dental clinic. however, 38.8% of teachers had not visited a dentist for more than a year or two, with 31.3% had visited a dentist in less than 6 months, with the least percentage 2.5% who had never been to a dentist before. regarding the question, which deals with the items used for keeping oral hygiene, as shown in figure 1. results revealed that 96.3% of teachers use toothbrush and toothpaste for cleaning their teeth, 22.5% use salt and warm water as a mouthwash, 11.3% of them use medical mouthwash, 6.3% floss their teeth, and the least proportion used miswak 3.8%. meanwhile, assessing the count of items used by teachers, results showed that most of them 70.0% used only a single item to keep their oral hygiene, 21.25% used 2 items and only 8.75% of them used 3-4 items to keep good oral health. moreover, in questions that came with multiple answer, the participants were free to choose more than one answer for each question, and this would explains why the total answering percentage does not equal the total sample number when dealing with these questions. caries experience as reviewed in table 4, he impact of teacher’s knowledge on caries experience, the mean (dmfs) of teachers was found to reach its highest value in teachers with the highest knowledge scores, a statistical significant difference (p<0.05) was recorded when comparing between the knowledge scoring terciles (23). while when dealing with teacher’s favourite attitude and practices regarding their oral health, the mean (dmfs) was found to be higher in teachers with the least favourite attitude and practices compared to those with the most favourite attitude and practices whom recorded the lowest (dmfs) mean, additionally, results showed a statistical significance difference (p<0.05) between the three categories. oral cleanliness and gingival health status regarding the impact of teacher’s knowledge on plaque and gingival indices, results showed that the mean value of plaque was obviously higher in teachers with the highest scores comparing to those with the lowest scores whom had the lowest plaque mean value, however, the statistical difference failed to reach the significance (p>0.05). similarly, the mean value of gi was found to be the highest in teachers who got the maximum scores regarding their knowledge about personal oral health, and the lowest in teachers who got the minimum scores, also, the difference observed was statistically significant (p<0.05). passing to the category that deals with teacher’s favourite attitude and practices regarding personal oral health, plaque and gingival indices mean values found to reach their highest values in teachers with the lowest attitude and practices scores comparing to the mean plaque and gingival indices, which registered the lowest values in teachers with the highest attitude and practices scores. although, the difference failed to reach the statistical significance (p>0.05). j bagh college dentistry vol. 30(3), september 2018 the impact of 43 table 1: assessment of teachers’ scores regarding their knowledge towards personal oral health. teachers’ knowledge questionnaire towards their personal oral health aware unaware don’t know no. % no. % no. % it is possible to prevent oral diseases by brushing, flossing and avoiding sugar. (true) 75 93.8 3 3.8 2 2.5 neglecting oral health causes periodontal disease such as swollen and bleeding gingiva. (true) 74 92.5 4 5.0 2 2.5 bleeding during brushing is a sign of gingival disease or wrong brushing technique.(true) 70 87.5 8 10.0 2 2.5 dental plaque can lead to dental caries. (true) 54 67.5 6 7.5 20 25.0 dental plaque means food remnants and bacteria on teeth. (true) 52 65.0 8 10.0 20 25.0 no pain in the mouth means the mouth is disease free. (false) 40 50.0 34 42.5 6 7.5 gingival bleeding is the first sign of tooth decay. (false) 36 45.0 28 35.0 16 20.0 tooth loss is a normal part of growing old. (false) 31 38.8 41 51.3 8 10.0 regular correct brushing of teeth does not protect from gingival bleeding. (false) 26 32.5 50 62.5 4 5.0 tooth decay is infectious (spread from person to person). (true) 22 27.5 48 60.0 10 12.5 table 2: assessment of teachers’ scores regarding their attitude and practices towards personal oral health. teachers’ attitude and practices of towards their personal oral health no. % frequency of teeth brushing once daily 20 25.0 twice or more daily 54 67.5 not always 6 7.5 time spend for brushing less than one minute. 13 16.3 about 1 minute 44 55.0 2 minutes or more 23 28.8 frequency of eating sweet snacks per day never or once daily 51 63.8 2-3 times 27 33.8 4+ times 2 2.6 items that you use for keeping oral hygiene (multiple answer) brushing with tooth paste 77 96.3 mouth wash 9 11.3 dental floss 5 6.3 warm water and salt 18 22.5 miswak 3 3.8 best time for tooth brushing at morning 15 18.8 at night 44 55.0 after each meal 21 26.3 frequency of dental clinic visits regular (every 6-12 months) 12 15.0 when sever toothache 57 71.3 occasionally 11 13.8 reasons for usual dental clinic visits dental pain 64 80.0 regular check-up time 3 3.8 esthetic 6 7.5 improving function 7 8.8 reasons behind not/ dislike visiting the dentist (multiple answer) fear of needle and/or drilling 49 61.3 high cost 34 42.5 no clinic nearby 3 3.8 no time 11 13.8 last visit to the dentist less than 6 months 25 31.3 6-12 months 22 27.5 1-2 years or more 31 38.8 never went to a dentist 2 2.5 j bagh college dentistry vol. 30(3), september 2018 the impact of 44 table 3: mean values and standard error (se) of teachers’ caries-experience regarding questionnaire scores. variables teachers score (terciles) no. dmfs mean ±se p-value* teacher's knowledge score about oral health lowest (<= 50) 32 33± 3.4 <0.001** average (51-70) 35 38± 4.1 highest (71+) 13 61± 9.5 teacher’s favourite attitude and practice score lowest (<= 41) 33 49± 5.2 0.035** average (42-53) 27 33± 4.0 highest (54+) 20 34± 4.6 *comparison of mean values of the three categories of each (kap) partanova test ** significant (p≤0.05) table 4: mean values and standard error (se) of teacher’s plaque and gingival indices regarding questionnaire scores. variables teachers score (terciles) pli gi no. mean ±se pvalue* mean ±se pvalue* teacher's knowledge score towards personal oral health lowest (<= 50) 32 1.28± 0.080 0.17 [ns] 1.12± 0.076 0.041** average (51-70) 35 1.31± 0.077 1.16± 0.081 highest (71+) 13 1.49± 0.112 1.43± 0.122 teacher’s favourite attitude and practices score lowest (<= 41) 33 1.40± 0.087 0.13 [ns] 1.30± 0.086 0.12 [ns] average (42-53) 27 1.33± 0.069 1.11± 0.073 highest (54+) 20 1.21± 0.100 1.10± 0.108 *comparison of mean values of the three categories of each (kap) partanova test ** significant (p≤0.05) [ns] not significant figure 1: bar chart showing the relative frequency of the most used oral hygiene items by teachers. 0 10 20 30 40 50 60 70 80 90 100 brushing with tooth paste only warm water and salt mouth wash dental floss miswak 96.3 22.5 11.3 6.3 3.8 j bagh college dentistry vol. 30(3), september 2018 the impact of 45 discussion this study assessed the oral health knowledge, attitude and practices among kindergarten teachers, and their impact on the oral health status of teachers themselves. the (kap) data were collected by means of self-administered questionnaires mainly because of practical reasons. in regards to teachers’ knowledge about personal oral health, it was relatively adequate but incomplete. majority of the respondents correctly identified the proper ways to prevent oral diseases in addition to their causes, and about the signs of periodontal diseases. however, the results of the present study vary conspicuously from previous studies that showed that only 50.0% of teachers had the basic knowledge of the causes and prevention of oral diseases (24, 25). meanwhile, only 32.5% aware that regular correct brushing technique can protect from gingival diseases, a finding that is not in line with a previous study (26). concerning teachers’ favorable attitude and practices towards personal oral health, which was generally poor, the largest proportion 67.5% brush twice or more daily, which is considered the most favorable practice (27). while when discussing the time consumed during brushing, results found that more than half of teachers spend about 1 minute. although, only 28.8% of them took about 2 minutes, which is supposed to be the most favorable duration (28). when considering the aids used in regular oral hygiene practices, results revealed that almost all teachers used toothbrush and toothpaste; one possible explanation could be the influence of family traditions in routine practices. this finding agreed with previous studies (29, 30). the percentage of teachers used dental floss as an oral hygiene maintenance tool was very low 6.3% and was approximate to figures reported form nigerian school teachers (30, 31).however, usage of medical mouthwash found to be higher than flossing, this might be related to the effect of visual media and advertising of these medical mouthwashes on teachers. preventive regular dental visit is widely considered as a standard oral health practice. in the current study, only 15.0% of teachers went to routine dental checkup every 6-12 months and this low percentage assure that very few of them understood the importance of visiting a dentist at least once, or twice annually. these findings emphasized the need for promoting the principles of preventive dentistry among kindergarten teachers and were not in agreement with some previous studies (32, 33). also noted among the teachers in the present study was the fact that the highest percentage of them 71.3% visited a dentist primarily because of sever dental pain. this finding was consistent with studies done elsewhere (30, 31). however, the least proportion had visited a dentist to improve function, aesthetic or routine checkup, which indicated that the utilization of dental services was mainly for pain relief, rather than for prevention and having a better oral health. these results concurred with amith et al. (34). generally, all the above disparities might be due to multiple reasons namely; lack of awareness, unaffordability or lack of accessible oral health services. concerning caries experience, an interesting finding was seen regarding teachers’ knowledge towards personal oral health, where the maximum mean was found in teachers with the highest knowledge, and a high statistical significant difference was recorded (p<0.001). this unexpected finding could suggest that even high knowledge might be not enough unless it is associated with healthy daily practices. however, the mean (dmfs) of teachers was found to be obviously higher in teachers with the lowest scores regarding their attitude and practices compared to those with the highest scores, with a statistically significant difference (p<0.05). all the preceding findings suggested that teachers’ knowledge have no impact on their oral condition. nevertheless, the more favourable attitude and practices, the less mean values regarding caries experience. thus, this showed that favourable oral health attitude and practices of teachers could cause a positive impact on personal oral condition. similarly, an inverse relationship was noticed in regards to teachers’ plaque mean value, as it raised with increasing the knowledge scores towards personal oral health, however, the statistical difference failed to reach the significance (p>0.05). likewise, the mean value of gingival index was found to be the highest in teachers who got the maximum scores and vice versa with a statistically significant difference (p<0.05). these confounding results regarding the relation between teacher’s knowledge towards personal oral health and their plaque and gingival health status might be related to different variables other than the level of knowledge, like age, educational status, years of experience, marital status or being a mother of children or not. however, when discussing teachers’ favorite j bagh college dentistry vol. 30(3), september 2018 the impact of 46 attitude and practices scores, the plaque and gingival mean values seems to decrease with increasing teachers’ scores regarding their favorable attitude and practices. these outcomes confirmed that healthy attitude and practices of teachers could be reflected positively on the oral health status of the teachers themselves. however, knowledge alone was not enough, unless it turns into real action. references 1. beley george b, john j, saravanan s, arumugham i. oral health knowledge, attitude and practices of school teachers in chennai. jiaphd 2010; 15:21-26 2. the world oral health report. continuous improvement of oral health in the 21 centurythe approach of the who global oral health programme geneva, 2004. 3. the world oral health report. continuous improvement of oral health in the 21 centurythe approach of the who global oral health programme geneva, 2006. 4. khan n, al-zarea b, al-mansour m. dental caries, hygiene, fluorosis and oral health 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disease in pregnancy i. acta odonto scand. 1963; 21:533-51. 22. world health organization. oral health surveys basic methods. 3rd ed. world health organization. geneva, switzerland, 1987. 23. hyndman rj, fan y. sample quantiles in statistical packages. am. stat., jasa 1996; 50(4):361–5. 24. elena b, petr l. oral health and children attitudes among mothers and schoolteachers in belarus. sbdmj 2004; 6:40-3. 25. sekhar v, sivsankar p, easwaran m, subitha l, bharath n, rajeswary k. knowledge, attitude and practice of school teachers towards oral health in pondicherry. journal of clinical and diagnostic research: jcdr 2014; 8(8):12. 26. aljanakh m, siddiqui a, mirza a. teachers’ knowledge about oral health and their interest in oral health education in hail, saudi arabia. int j health sci (qassim) 2016; 10(1):88-93. 27. marya a. textbook of public health dentistry.1st ed. jaypee brothers, new delhi, 2011. 28. world health organization. fact sheet: oral health. world health organization. geneva, 2014. 29. zhu l, yingwang p, bian j, zhang b. oral health knowledge, attitudes and behaviour of adults in china. int dent j 2005; 55:231-41. 30. mota a, oswal k, sajnani d, sajnani a. oral health knowledge, attitude, and approaches of pre-primary and primary school teachers in mumbai, india. hindawi publishing corporation, scientifica 2016; 2016: 8 pages. 31. ehizele a, chiwuzie j, ofili a. oral health knowledge, attitude and practices among nigerian primary school teachers. int j dent hyg 2011; 9(4):254–60. j bagh college dentistry vol. 30(3), september 2018 the impact of 47 32. pai v, sequeria ps, rao a, kundabala m. dental awareness among kannada and english medium primary school teachers in mangalore city. j indian assoc public health dent 2006; 7:7‑12. 33. tangade ps, jain m, mathur a, prasad s, natashekara m. knowledge, attitude and practice of dental caries and periodontal disease prevention among primary school teachers in belgaum city, india. pesq bras odontoped clin integr, joão pessoa 2011; 11(1):77-83. 34. amith hv, d’cruz am, shirahatti rv. knowledge, attitude and practice regarding oral health among the rural government primary school teachers of mangalore, india. int j dent hyg 2013; 87(6):362-9. الخالصة دورا هاما في تمرير المعلومات هم أن يلعبوافي أي نظام تعليمي. وبما أنه يمكن ةقف محوريامو ذاتعتبر المعلمون قوة ديناميكية ي الخلفية: ، والممارسات مطابقة للتوصيات المهنية. واالساليب الفم،أن تكون المعرفة الصحية الخاصة بصحة الوقائية وتعزيز الصحة، من المهم لصحية الفموية أثيرها على الحالة ارياض األطفال وت إلى تقييم معرفة صحة الفم وأساليبه وممارساته بين معلماتهدفت هذه الدراسة العراق.للمعلمات في قطاع الرصافة في بغداد / يحتوي هذا ذاتيا على المعلمات. يملئتم توزيع استبيان في رياض األطفال. وقد معلمة 08 علىي هذا المسح المقطعي أجر المواد والطرق: . وقد ذلك فحص فموي سريري لجميع المعلمات ستبيان على جزأين يتناوالن معار صحة الفم واساليب وممارسات المعلمات، وتااال يإجراء تحليل وصفي وتحليل البيانات باستخدام اختبار تاها استخدمت تقنية أخذ العينات العشوائية البسيطة الختيار المشاركين في الدراسة بونفيروني تي واختبار أنوفا. على بينة من ( من المعلمات٪8..0وكان أكثر من )معرفة كافية ولكن غير مكتملة فيما يتعلق بصحة الفم. أظهرت المعلمات النتائج: ( من المعلمات كان لديهن ٪8..0الفم. حوالي ) التأثير السيئ إلهمال نظافة جيدة وكذلك معرفةالللحفاظ على صحة الفم التدابير الوقائية كانوا على بينة من عامات تسوس األسنان، ( منهن٪8..0ئة. وفي الوقت نفسه، )السي هاثاروا مكونات الصفيحة الجرثوميةالوعي حول على اللثة. لم ياحظ وجود اختافات واضحة فيما االسنان الصحيح والمنتظم ن فوائد استخدام فرشاةبينة م منهن على( ٪...5) فيما كان ، ومع ذلك، تم جرثومية ومؤشرات اللثة للمعلمات فيما يخص مستوى معار المعلماتاالسنان، الصفيحات التسوس ل بالقيم المتوسطةيتعلق اللثة. تسوس االسنان، الصفيحات الجرثومية ومؤشرات ل القيم ومتوسط المفضلة والممارسات ثور على عاقة إيجابية بين االساليبالع وجود العديد منهن ممن يتبنين معلصحة الفم معرفة كافية ولكن غير مكتملة بالدراسة عينة المعلمات اللواتي شاركنأظهرت االستنتاجات: ل حول المعرفةرياض األطفا رية لبرنامج تعليمي متكامل لمعلماتحاجة واضحة وفو ما يؤشر وجود أساليب وممارسات غير صحيحة ة للمعلمات أن تؤثر بشكل إيجابي على حالتهن، يمكن للممارسات الصحيوالممارسات المواتية. عاوة على ذلك األساسية لصحة الفم الصحية الفموية. رياض األطفال. ، األساليب، الممارسات، معلماتمعار صحة األسنانثر، األكلمات البحث: journal of baghdad college of dentistry, vol. 34, no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 29 research article the relationship of implant stability quotient and insertion torque in dental implant stability ali t. noaman1.*, salwan y., bede2 1 phd student, oral surgery unit, specialized dental health center in al-sheikh omar, baghdad health directorate-al-rusafa, ministry of health 2 professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad.bab-almoadham, p.o. box 1417, baghdad, iraq *correspondence: alitareef79@gmail.com abstract: background: the insertion torque (it) values and implant stability quotient (isq) values are the measurements most used to assess primary implant stability. this study aimed to assess the relationship between isq values and it. materials and methods: this study included 24 patients with a mean (sd) age of 47.9 (13.64) years (range 25-75 years). the patients received 42 dental implants (di), 33 in the mandible and 9 in the maxilla. the di were installed using the motorized method with 35 ncm torque, when di could not be inserted to the requisite depth by the motorized method, a hand ratchet was used and the it was recorded as ˃ 35 ncm. implant stability was measured utilizing osstell® isq. the secondary stability was measured after 16 weeks postoperatively.results: the di installed in mandible demonstrated significantly higher primary stability isq values than those installed in maxilla (p=0.0101). there was no such significant correlation linked between the secondary stability and the recipient jaw (p=0.2026). a non-significant correlation was found between the primary and secondary implant stability isq values and it (p=0.2785 and 0.4194, respectively). no significant difference was reported regarding the it relative to the recipient jaw of di (p=0.1349).conclusion: this study demonstrated that there was no relationship between the isq values and the it, and that they should be used independently. di installed in mandible demonstrated significantly higher primary stability isq values than those installed in maxilla. also, there was a non-significant correlation of the secondary stability and it with the recipient jaw. keywords: dental implants, insertion torque, implant stability. introduction the successful outcome of dental implants (di) depends on a sequence of patient-related and procedure dependent elements, including general health conditions, biocompatibility of the implant material, the implant surface features, the surgical procedure, and the local bone quality and quantity (1). implant stability may be defined as "the capacity of implant to withstand loading in axial, lateral and rotational direction", (2) it is split into two parts: primary and secondary. primary stability refers to "the mechanical bracing of the implant in bone and absence of any micro-movement", while secondary stability is referred to "successful osseointegration of the implant with the surrounding" (3). at the time of implant insertion, primary stability is crucial. the most important factor for successful osseointegration is a solid anchoring of the implant within the host bone, free of micromotions. micro-motions may develop if an implant is not sufficiently stable at the time of implant placement, disrupting the normal healing process and forming a fibrous tissue capsule, resulting in clinical mobility and eventual implant failure (4). received date: 1-11-2021 accepted date:: 5-12-2021 published date: 15-3-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by /4.0/). https://doi.org/10.26477/j bcd.v34i1.3089 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3089 https://doi.org/10.26477/jbcd.v34i1.3089 j. bagh. coll. dent. vol. 34, no. 1. 2022 noaman and bede 30 there are numerous techniques to assess implant stability. these can be divided into two categories: the invasive and noninvasive methods (3). the insertion torque (it) (during surgery, for primary stability), and resonance frequency analysis (rfa) (during and after surgery to measure primary and secondary stability) are the two most common noninvasive approaches for determining implant stability nowadays. rfa device measurements (implant stability quotient, isq) have been shown to give crucial information to the surgeon on the present status of the bone implant interface which, together with clinical/radiographic findings, can aid decision-making during implant placement and follow-up in terms of healing durations, loading technique, and the identification of implants at risk of failure (5). it is critical to determine whether or not the it and isq values are equivalent. both approaches can be employed in clinics, particularly because the isq has been widely used owing to its applicability in a variety of settings, including implant placement, healing, and with the prosthesis in place (6). the aim of this study was to assess the relationship between the isq values and it as a measurement of implant stability. materials and methods this clinical prospective observational study was conducted at the department of oral and maxillofacial surgery, college of dentistry, university of baghdad from september 2019 to june 2021. it included patients who presented with missing teeth that were restored with implant supported fixed prostheses. the institutional research ethics committee approved the protocol of this study (protocol number 036118), and patients were informed about the nature of the study and they signed an informed consent to participate in this study. the inclusion criteria were; adult patients ≥ 18 years old of both genders with good general health presenting with partially edentulous maxilla or mandible with a minimum of 6 months after teeth extraction. the patients should have sufficient alveolar bone ridge dimensions with a minimum 6 mm width and 10 mm height. the exclusion criteria were; any uncontrolled systemic disease that could interfere with normal healing, current pregnancy, history of irradiation of the head and neck region or chemotherapy over the past 5 years, patients treated with bisphosphonate drugs which affect bone metabolism, any local condition such as the presence of infection or local pathological conditions in the proposed implant zone, active periodontitis and patients with clinical evidence of para-functional habits. a cbct (cone beam 3d system kavo op 3d pro, germany), set at 90 kv, 9.2 ma and 8.1s with (13 × ø15) c fov and 0.5 mm slice in thickness, was taken for preoperative assessment of the planned implant site. the assessment was performed using ondemand3d™ software (cybermed inc.©, seoul, korea), it included the bone height and width of alveolar ridge at the proposed implant site and also to determine the dimensions of the implant to be installed so that the implant apex is to be at least 2 mm above mandibular canal and 2 mm away from mental foramen, 1 mm below nasal cavity and 1 mm below the floor and the anterior wall of maxillary sinus as shown in (fig. 1). figure 1: the cbct cross section view with bone dimensions measurement. j. bagh. coll. dent. vol. 34, no. 1. 2022 noaman and bede 31 all the procedures were performed under local anesthesia lidocaine hydrochloride 2% with epinephrine (1:80,000). a mucoperiosteal flap was reflected and the implant site preparation proceeded using osteotomy drills of increasing diameter corresponding to the implant dimensions with an implant micromotor (dental surgery micromotor ict, dentium, korea) rotating at a speed of 800 rpm with copious saline irrigation. the implants (superline, dentium, seoul, korea) were installed into the osteotomy site using the motorized method with the engine set at 50 rpm and 35 ncm torque, so that the implant platform is 0.5-1 mm below the bone level. when the implant could not be inserted to the requisite depth by the motorized method, a hand ratchet was used and the it was recorded as ˃ 35 ncm. accordingly, in this study, implants were categorized into two groups regarding the it; one group with 35 ncm insertion torque and the other ˃ 35 ncm. immediately after insertion of di, the primary stability was measured using osstell®isq (osstell®, gothenburg, sweden). two repeated measurements were obtained for each implant along the buccolingual and mesiodistal axis and the mean of these two readings was taken (fig. 2). figure 2: implant stability measurement using osstell® isq. patients were instructed for follow up visit at 16 weeks postoperatively. the implants were uncovered and the secondary stability was measured in the same manner described in primary stability measurement. the outcome variables were the primary and secondary stability measured as implant stability quotient (isq) and the it and their correlations with the recipient jaw. graphpad prism version 6 for windows was used to carry out the statistical analysis (graphpad software, la jolla, ca, usa). percentages, mean, standard deviation (sd) were all computed as part of descriptive statistical analysis. the inferential analysis included using shapiro-wilk normality test, unpaired t-test, and chi-square test. the probability value <0.05 was considered statistically significant. results this study included 24 patients, 14 females (58.3%) and 10 males (41.7%). the mean (sd) age of patients was 47.9 (13.64) years (range 25-75). the patients received 42 di, of which 33 (78.6%) were installed in the mandible and the remaining 9 (21.4%) in the maxilla. the mean (sd) of the primary stability was 79.58 (5.27) isq, while that of the secondary stability was 74.3 (6.34) isq. in 22 di (52.4%), the it was 35 ncm, while in the remaining 20 di (47.6%), an it of ˃ 35 ncm was needed for the final seating of the di. at the end of this study all the implants were clinically stable achieving an early survival rate 100%. the effect of the recipient jaw on the primary stability isq values the di installed in the mandible demonstrated significantly higher primary stability isq values than those installed in the maxilla, table (1). j. bagh. coll. dent. vol. 34, no. 1. 2022 noaman and bede 32 table (1): the differences of the primary stability isq value in relation to the recipient jaw. abbreviations: isq, implant stability quotient; sd, standard deviation; s, significant; *, unpaired ttest. the effect of the recipient jaw on the secondary stability isq values there was a non-significant difference in the secondary stability isq values relative to the recipient jaw, table (2). table (2): the differences of the secondary stability isq value in relation to the recipient jaw. recipient jaw number of values secondary stability/ isq p value mean sd mandible 33 75.09 6.44 0.2026 [ns]* maxilla 9 72.00 5.87 abbreviations: isq, implant stability quotient; sd, standard deviation; ns, non-significant; *, unpaired t-test. correlation of it and the primary stability isq values there was a non-significant difference in the primary stability isq values between the di that were installed with an it of 35 ncm and those installed with an it > 35 ncm, table (3). table (3): the differences of the primary stability isq value between the di that were installed with an it of 35 and > 35 ncm. abbreviations: it, insertion torque; isq, implant stability quotient; sd, standard deviation; ns, nonsignificant; *, unpaired t-test. correlation of it and the secondary stability isq values there was a non-significant difference regarding the secondary stability isq values between di that were installed with an it of 35 ncm and those installed with an it > 35 ncm, table (4). recipient jaw number of values primary stability/ isq p value mean sd mandible 33 80.65 5.23 0.0101 [s]* maxilla 9 75.67 3.33 insertion torque/ ncm number of values primary stability/ isq p value mean sd 35 22 78.93 5.32 0.2785 [ns]* > 35 20 80.30 5.26 j. bagh. coll. dent. vol. 34, no. 1. 2022 noaman and bede 33 table (4): the differences of the secondary stability isq value between the di that were installed with an it of 35 and > 35 ncm. insertion torque/ ncm number of values secondary stability/ isq p value mean sd 35 22 73.55 6.40 0.4194 [ns]* > 35 20 75.15 6.32 abbreviations: it, insertion torque; isq, implant stability quotient; sd, standard deviation; ns, nonsignificant; *, unpaired t-test. the effect of the recipient jaw on the it there was a non-significant difference regarding the it relative to the recipient jaw, table (5). table (5): the differences of the it in relation to the recipient jaw. recipient jaw it 35 ncm/ number of implants it>35 ncm/ number of implants p value mandible 15 18 0.1349 [ns]* maxilla 7 2 abbreviations: it, insertion torque; ns, non-significant; *, fisher's exact test. discussion the most commonly used methods for assessing primary implant stability are it and rfa (7). the link between these methods is poorly understood in the literature. the downside of it is that it can only be measured once, at the moment of implant placement, whereas rfa may be utilized during the whole implant treatment phases (8). meredith et al. (9) stated that rfa is a method that may be used as a research tool and is beneficial in evaluating the behavior of implants in surrounding tissue. also, jaramillo et al. (10) reported that rfa technologies in osstell® mentor and osstell® isq provide nearly perfect reproducibility, repeatability, and precision. however, degidi et al. (11) demonstrated that in clinical practice, the it is still a simple and accurate metric for assessing the primary stability of di. the findings of this study revealed that di installed in the mandible demonstrated significantly higher primary stability isq values than those installed in the maxilla. this finding is in line with other studies, (12,13) and it may be explained by the fact that the mandible is characterized by denser bone than the maxilla (14). primary stability arises from the compression of bone and it is linked to the mechanical engagement of implant with the surrounding bone and it depends on the quantity and quality of local bone in addition to other factors (15). moreover, many studies indicated a positive correlation of primary implant stability and bone density (16–18). conversely, other studies (19) reported that there was no significant relationship between the implant stability and bone density. secondary stability, on the other hand, demonstrated a non-significant association relative to the recipient jaw, which concords with gómez-polo et al. (20) who stated that regardless of bone type, the progressive development of bone surrounding the implant associated with secondary stability compensates for any differences in mechanical anchoring primary stability. in this study, there was a non-significant difference in primary stability isq values between the di that were installed with an it 35 ncm and those installed with it > 35 ncm. other authors (6, 21) j. bagh. coll. dent. vol. 34, no. 1. 2022 noaman and bede 34 also reported that it and rfa appeared as two independent features of primary stability. a recent systematic review (6) concluded that irrespective of the implant dimensions and protocol used in the previous studies, there was no relationship between the two methods of assessing primary stability, it proposed that the two values should be assessed separately, because a high torque does not always imply a high isq and vice versa. a plausible explanation could be related to the relaxation that would take place immediately after implant insertion, this can have an effect on both isq and bone implant contact measurements. furthermore, it is well understood that both isq and bone contact measurements may be influenced by the viscoelastic nature of the bone and possibly simultaneous relaxation that occurs directly after implant placement (22). however, other studies (12, 20) reported a significant relationship between it and primary stability isq values, indicating that a higher it predicts greater primary isq values. in this study, there was no relationship between secondary stability and it of di. this finding is in a line with gómez-polo (20), and can be attributed to the fact that bone remodeling and bone apposition on di surface (osseointegation) that occurs during the healing period may reduce the effect of implant it. a non-significant difference regarding it was observed relative to the recipient jaw of di. this coincides with farré-pagès et al. (12) who found no statistically significant differences according to different jaws locations. they observed only a slight trend of it increase in the mandible than in the maxilla (42.34 and 40.22 ncm, respectively). on the other hand, salimov et al. (13) indicated higher it values for di placed in the mandible when compared to the maxilla. conclusions the small sample size may limit the generalization obtained in this study; nevertheless it demonstrated that there was no relationship between the isq values and the it, and that they should be used independently for estimating the bone implant interface condition. the findings of this study also showed that di installed in mandible demonstrated significantly higher primary stability isq values than those installed in maxilla. whereas, there was no such significant correlation of the secondary stability and it with the recipient jaw. conflict of interest: none declared references 1. turkyilmaz i, tözüm tf, tumer c. bone density assessments of oral implant sites using computerized tomography. j oral rehabil. 2007;34(4):267–72 . 2. mesa f, muñoz r, noguerol b, et al. multivariate study of factors influencing primary dental implant stability. clin oral implants res. 2008;19(2):196–200 . 3. sennerby l. mn. implant stability measurements using resonance frequency analysis : biological and biomechanical aspects and clinical implications. periodontol 2000. 2008;47:51–66 . 4. meyer u, joos u, mythili j, et al. ultrastructural characterization of the implant/bone interface of immediately loaded dental implants. biomaterials. 2004;25(10):1959–67 . 5. sachdeva a, dhawan p, sindwani s. assessment of implant stability: methods and recent advances. br j med med res. 2016;12(3):1–10 . 6. lages fs, douglas-de oliveira dw, costa fo. relationship between implant stability measurements obtained by insertion torque and resonance frequency analysis: a systematic review. clin implant dent relat res. 2018;20(1):26–33 . 7. lozano-carrascal n, salomó-coll o, gilabert-cerdà m, et al. effect of implant macro-design on primary stability: a prospective clinical study. med oral patol oral cir bucal. 2016;21(2):e214 . 8. levin bp. the correlation between immediate implant insertion torque and implant stability quotient. int j periodontics restor dent. 2016;36(6):833–40 . j. bagh. coll. dent. vol. 34, no. 1. 2022 noaman and bede 35 9. meredith n, alleyne d, cawley p. quantitative determination of the stability of the implant-tissue interface using resonance frequency analysis. clin oral implants res. 1996;7(3):261–7 . 10. jaramillo r, santos r, lázaro p, et al. comparative analysis of 2 resonance frequency measurement devices: osstell mentor and osstell isq. implant dent. 2014;23(3):351–6 . 11. degidi m, daprile g, piattelli a. primary stability determination of implants inserted in sinus augmented sites: 1-step versus 2-step procedure. implant dent. 2013;22(5):530–3 . 12. farré-pagès n, augé-castro ml, alaejos-algarra f, et al. relation between bone density and primary implant stability. med oral patol oral cir bucal. 2011;16(1):62–7 . 13. salimov f, tatli u, kürkçü m, et al. evaluation of relationship between preoperative bone density values derived from cone beam computed tomography and implant stability parameters: a clinical study. clin oral implants res. 2014;25(9):1016–21 . 14. di stefano da, arosio p, pagnutti s, et al. distribution of trabecular bone density in the maxilla and mandible. implant dent. 2019;28(4):340–8 . 15. strub jr, jurdzik ba, tuna t. prognosis of immediately loaded implants and their restorations: a systematic literature review. j oral rehabil. 2012;39(9):704–17 . 16. song y-d, jun s-h, kwon j-j. correlation between bone quality evaluated by cone-beam computerized tomography and implant primary stability. int j oral maxillofac implants. 2009;24(1):59–64 . 17. merheb j, vercruyssen m, coucke w, et al. relationship of implant stability and bone density derived from computerized tomography images. clin implant dent relat res. 2018;20(1):50–7 . 18. al-jamal mfj, al-jumaily ha. can the bone density estimated by cbct predict the primary stability of dental implants? a new measurement protocol. j craniofac surg. 2021;32(2):e171–4 . 19. youssef m, shaaban am, eldibany r. the correlation between bone density and implant stability. alexandria dent j. 2015;40(1):15–21 . 20. gómez-polo m, ortega r, gómez-polo c, et al. does length, diameter, or bone quality affect primary and secondary stability in self-tapping dental implants? j oral maxillofac surg. 2016;74(7):1344–53 . 21. degidi m, daprile g, piattelli a. primary stability determination by means of insertion torque and rfa in a sample of 4,135 implants. clin implant dent relat res. 2012;14(4):501–7 . 22. açil y, sievers j, gülses a, et al. correlation between resonance frequency, insertion torque and bone -implant contact in self-cutting threaded implants. odontology. 2017;105(3):347–53 . العالقة بين حاصل ثبات الغرسة وعزم األدخال في ثباتية غرسة السن العنوان: سلوان يوسف حنا, 1 علي طريف نعمانالباحثون: المستخلص: قيم حاصل هذه الدراسة إلى تقييم العالقة بين هدفت . األولية استخداًما لتقييم استقرار الغرسةهي القياسات األكثر ( isq)وقيم حاصل استقرار الغرسة ( it)قيم عزم اإلدخال الخلفية: . (it)و قيم عزم اإلدخال isq استقرار الغرسة في زرعة أسنان 33)زرعة أسنان 42تلقى المرضى (. سنة 75-25المدى )سنة ( 13.64) 47.9عمر المرضى كان متوسط . مريضا 24شملت هذه الدراسة المواد وطرق العمل: ، تم إجراء عملية تحضير موقع الزرع بطريقة متسلسلة ، وتم تثبيت (cbct)تم أخذ التصوير المقطعي المحوسب بحزمة مخروطية قبل الجراحة . في الفك العلوي 9الفك السفلي و قيم تسجيل قاطة اليدوية وخدام السإلى العمق المطلوب ، تم است زرعة أسنانإدخال ، عندما تعذر نيوتن سم 35 بعزم دورانباستخدام الطريقة اآللية ( ، كوريا دنتيوم) زرعة أسنان أسبوعًا من الجراحة ، وتم قياس 16تم توجيه المرضى لزيارة المتابعة بعد . osstell® isq جهاز تم قياس ثبات الغرسة باستخدام. نيوتن سم 35 اكثر من على أنهاعزم اإلدخال بين الثبات لم يكن هناك ارتباط معنوي. للثبات األولي أعلى بكثير من تلك المثبتة في الفك العلوي isqفي الفك السفلي قيم ة المثبت زرعات أالسنان ت أظهر النتائج: . االستقرار الثانوي بقيم عزم اإلدخال فيما يتعلق لم يتم اإلبالغ عن اختالف كبير . وقيم عزم اإلدخال ةاستقرار الزرع isqتم العثور على عالقة غير ذات داللة إحصائية بين قيم . الثانوي والفك المستلم .زرعات أالسنانبالنسبة إلى الفك المستلم لـ .العظم االسنان مع واجهة غير مرتبطة ، ويجب استخدامها بشكل مستقل لتقدير حالة زرعةوقيم عزم اإلدخال isqخلصت هذه الدراسة إلى أن قيم االستنتاج: j bagh college dentistry vol. 33(4), december 2021 the effect of recipient 31 the effect of recipient jaw and implant dimensions on preand post-loading dental implant stability: a prospective clinical study dhuha a. al-assaf (1), salwan y. bede (2) https://doi.org/10.26477/jbcd.v33i4.3017 abstract background: implant stability is a mandatory factor for dental implant (di) osseointegration and long-term success. the aim of this study was to evaluate the effect of implant length, diameter, and recipient jaw on the preand post-functional loading stability. materials and methods: this study included 17 healthy patients with an age range of 24-61 years. twenty-two di were inserted into healed extraction sockets to replace missing tooth/teeth in premolar and molar regions in upper and lower jaws. implant stability was measured for each implant and was recorded as implant stability quotient (isq) immediately (isq0), and at 8 (isq8) and 12 (isq12) weeks postoperatively, as well as post-functional loading (isqpfl). the pattern of implant stability changes throughout the study period and its correlation with the recipient jaw and the di dimensions were evaluated. results: there was a significant difference in isq values throughout the study. di stability in the maxilla was significantly higher than that in mandible for the isq0, with no significant effect for the rest time points. the effect of implant diameter was significant with di of 4.1mm diameter being more stable. while for the length, there was no significant difference regarding its effect on isq values throughout the study period. conclusions: di inserted in the maxilla demonstrated better primary stability with no effect of recipient jaw on secondary stability and after functional loading, also di with wider diameter had better stability throughout the study whereas di length showed no significant effect on stability. keywords: implant stability, implant dimensions, recipient jaw. (received: 25/9/2021, accepted: 31/10/2021) introduction many factors directly affect the success of dental implant (di) treatment, which could be considered a challenge to clinicians. one of these factors is the implant stability, which is of two types, primary and secondary (1). primary stability is the mechanical engagement of an implant within the surrounding bone, while bone regeneration and remodeling determine the secondary (biological) stability (2). alveolar bone quantity and quality, length, diameter, and form of the implant, as well as the surgical technique, are also among the clinical factors that affect dental implant stability (3, 4, 5). for this reason, it is believed that factors that can increase the contact area between the implant and the surrounding bone, such as the implant shape and dimensions (length and diameter) can increase the implant stability, and should be taken into account as they can play a role in the formation of the bone-to-implant contact (6). different methods have been advocated to evaluate di stability, such as torque at the time of implant placement, resistance to reverse torque, and resonance frequency analysis (rfa) (7). (1) phd student, oral and maxillofacial surgery unit, alyarmouk teaching hospital, baghdad health directorate alkarkh, ministry of health. (2) professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad corresponding email, salwan.bede@gmail.com the osstell® device (göteborg, sweden) has been introduced to provide an objective measurement of di primary stability and to monitor the changes in the stability over the healing/ osseointegration period. many experimental and clinical studies showed an increase in rfa values during healing period after implant placement. these increased implant stability quotient (isq) values could be attributed to increased bone anchorage (8, 9). the absence of micro-movements is a necessary condition for successful implant osseointegration, and it can be obtained by achieving stable implant immediately post-insertion (primary stability) and during healing period (secondary stability) (10). therefore, the aim of the present study was to evaluate the influence of di dimensions (length and diameter) and recipient jaw on the preand post-loading implant stability. materials and methods this prospective clinical study was performed at the department of oral and maxillofacial surgery, college of dentistry, university of baghdad during the period extending from july 2019 through february 2021. the study protocol was reviewed and approved by the research ethics committee of the college of dentistry, university of baghdad (protocol number 034118). https://doi.org/10.26477/jbcd.v33i4.3017 j bagh college dentistry vol. 33(4), december 2021 the effect of recipient 32 the study included 17 consecutive patients who met the eligibility criteria. to be included, patients had to be over 18 years of age, having single or multiple missing teeth in the posterior maxilla or mandible with healed extraction sites of a minimum of 6 months, and exhibiting sufficient vertical (at least 10 mm) and horizontal (at least 5 mm) dimensions of the alveolar bone that are considered surgically straightforward cases according to sac classification (11). patients were excluded if they had signs of active or chronic infection in the implant zone, history of radiotherapy to the head and neck, history or were currently under treatment with drugs that may alter bone metabolism, and patients who were heavy smokers or presented with severe periodontitis. the patients received a total of 22 bone level tapered dis (straumann®. basel, switzerland). all procedures were performed under local anesthesia. after reflection of a full-thickness mucoperiosteal flap, the implant bed was prepared through sequential drilling according to the manufacturers’ instructions, and the implants were inserted about 0.5 mm subcrestally. dis used in this study were 3.3mm and 4.1mm in diameter with 8mm, 10mm, and12mm in length. implant stability measurement implant stability was measured using the osstell® mentor (göteborg, sweden) and was recorded as isq value. the measurements were repeated 2 times for each implant, with buccolingual and mesiodistal directions and the average of these measurements was recorded. implant stability was measured immediately after implant insertion (primary stability, isq0), after 8 weeks, at the time of healing abutment placement (isq8), and after 12 weeks (secondary stability, isq12). the implant stability was also measured after about 25 weeks of functional loading (isq post-functional loading, isqpfl). the outcome variables of this study included the isq changes during the study period and their correlation with the recipient jaw (maxilla and mandible) and di dimensions (diameter and length). statistical analysis the descriptive statistics included the mean (standard deviation, sd) and the median of the continuous variables and the percentages of the categorical variables. the shapiro-wilk test was used to determine the normality of distribution of the continuous variables. the inferential statistics included using the friedman test with the multiple comparison test, the unpaired t-test, mann whitney u test, and the kruskal wallis test. the significance level was p< 0.05. results this study included 17 patients with an age range of 24-61 years and a mean (sd) of 42.9 (9.8) years, they consisted of 11 (64.7%) females and 6 (35.3%) males. the patients received 22 dis, the mean number of implants per individual was 1.3. seventeen dis (77.3%) were inserted in the mandible and the remaining 5 (22.7%) were installed in the maxilla. the distribution of dis according to the dimensions is summarized in the table 1. table 1: the distribution of dis according to the dimensions implant dimensions number % width/mm 4.1 13 59.1 3.3 9 40.9 length/mm 8 4 18.2 10 11 50 12 7 31.8 all dis were osseointegrated and functional at the end of the study with an early success rate of 100%. the implant stability recorded throughout the study is summarized in table 2. generally, there was a significant difference in implant stability, the multiple comparison test revealed that there was a non-significant decrease in implant stability at 8 weeks followed by a significant increase at 12 weeks and after functional loading (fig. 1). table 2: the implant stability recorded throughout the study period implant stability /isq isq0 isq8 isq12 isq pfl pvalue mean 96.27 66.95 73.50 78.41 < 0.000* sd 6.37 5.03 4.92 4.06 median 69.00 70.00 73.00 78.00 isq, implant stability quotient; sd, standard deviation; * friedman test j bagh college dentistry vol. 33(4), december 2021 the effect of recipient 33 im p la n t s t a b il it y q u o t ie n t ( is q ) is q 0 is q 8 is q 1 2 is q p f l 5 0 6 0 7 0 8 0 9 0 figure 1: box plot showing the difference in implant stability throughout the time points of the study the effect of the recipient jaw there was a significant difference in implant stability recorded immediately after insertion (primary stability). however, the implant stability recorded after 8, 12 weeks (secondary stability) and after functional loading demonstrated nonsignificant differences between the mandible and the maxilla (table 3 and fig. 2). im p la n t s t a b il it y q u o t ie n t ( is q ) is q 0 is q 8 is q 1 2 is q p f l 5 0 6 0 7 0 8 0 9 0 m a x illa m a n d ib le figure 2: line graph showing the difference in implant stability in the maxilla and the mandible the effect of implant dimensions with respect to di diameter, wider implants (4.1mm) demonstrated significantly higher implant stability than di with 3.3 mm diameter in all measurement times, but the differences were significant only in secondary stability and after functional loading (table 4 and fig. 3). im p la n t s t a b il it y q u o t ie n t ( is q ) is q 0 is q 8 is q 1 2 is q p f l 5 0 6 0 7 0 8 0 9 0 4 .1 m m 3 .3 m m figure 3: line graph showing the difference in implant stability in relation to di diameter analysis of the di length demonstrated that there were non-significant differences in implant stability in all measurement times (table 5 and fig. 4). im p la n t s t a b il it y q u o t ie n t ( is q ) is q 0 is q 8 is q 1 2 is q p f l 5 0 6 0 7 0 8 0 9 0 8 m m 1 0 m m 1 2 m m figure 4: line graph showing the difference in implant stability throughout the study in relation to di length table 3: the differences in implant stability between the maxilla and the mandible measurement time maxilla n=5 mandible n=17 p-value mean sd median mean sd median isq 0 74.60 4.93 76.00 67.71 5.98 69.00 0.0325 * isq 8 68.80 3.27 70.00 66.41 5.40 70.00 0.5563 * isq 12 76.40 4.51 79.00 72.65 4.82 73.00 0.1792 * isq pfl 80.00 1.87 80.00 77.94 4.44 77.00 0.3085 * isq, implant stability quotient; sd, standard deviation; * mann whitney u test j bagh college dentistry vol. 33(4), december 2021 the effect of recipient 34 table 4: the differences in implant in relation to di diameter measurement time implant diameter 4.1mm (n=13) implant diameter 3.3mm (n=9) p-value mean sd median mean sd median isq 0 69.69 7.521 72.00 68.67 4.583 69.00 0.7200 † isq 8 68.62 3.042 70.00 64.56 6.444 67.00 0.3044 * isq 12 75.54 4.557 77.00 70.56 3.972 73.00 0.0153 † isq pfl 80.54 3.666 81.00 75.33 2.236 74.00 0.0012 † isq, implant stability quotient; sd, standard deviation; † unpaired t test; * mann whitney u test table 5: the differences in implant stability in relation to di length measurement time implant length 8mm (n=4) implant length 10mm (n=11) implant length 12mm (n=7) p-value mean sd median mean sd median mean sd median isq 0 68.50 5.916 68.00 68.27 7.564 69.00 71.29 4.716 69.00 0.7649* isq 8 68.50 3.697 70.00 69.27 2.149 70.00 62.43 6.214 59.00 0.0950* isq 12 75.25 5.439 76.00 73.45 5.628 73.00 72.57 3.735 73.00 0.6760* isq pfl 79.00 4.899 80.00 79.45 4.156 78.00 76.43 3.155 74.00 0.3652* isq, implant stability quotient; sd, standard deviation; * kruskal wallis test discussion implant stability can be defined as the absence of clinical mobility, based on mechanical stability criteria. this can be considered one of the clinical signs of implant osseointegration in the bone (12). the results of this study demonstrated that there was a drop in implant stability during the early postoperative period that was manifested as a reduction in isq values 8 weeks after implant insertion followed by an increase that is extended progressively into the 12th week postoperatively and even after loading the implants. this drop in implant stability, although it was non-significant, is associated with the resorption of peri-implant bone during the early postoperative period that represents the transition from the primary to the secondary stability. this resorption was demonstrated by berglundh et al., (13) in an animal study, where the authors observed that during the first 4 weeks after implant insertion, the bone responsible for the primary stability was resorbed and replaced by new viable bone, they also noted that, despite this remodeling process, the implants remain stable. this pattern of implant stability change during the pre-loading phase is also demonstrated in other clinical studies. han et al. (14) followed the isq values of 25 dis at baseline, 4 days, 1, 2, 3, 4-, 6-, 8and 12-weeks post surgery, and they observed that the isq decreased by 3-4 values after installation and reached the lowest values at 3-4 weeks and then increased steadily for all implants and up to 12 weeks. koshy et al., (15) showed similar pattern of changes in isq values over the course of healing/ osseointegration, and reported a decrease of 4-5 isq units post implant installation, while rosen et al. (16) reported a range of 3 to 9 units for this physiological dip in di stability. the mean difference of the physiological reduction in isq values, in this study, was 2.32 units, which could be considered lower than those figures reported by previous studies. primary stability is a requisite at the time of implant placement and it is related to the local bone quality and quantity, implant geometry (length, diameter, and type), and placement technique (17). in the present study, the recipient jaw had no significant effect on isq values except for the primary stability, where maxillary implants demonstrated higher stability, however, on examining the data, it can be observed that dis inserted in the mandible maintained better stability during the early postoperative period obtaining a mean difference of -1.3 isq values compared to that of the maxillary dis that was much higher (5.8 isq values). vollmer et al. (18) observed a j bagh college dentistry vol. 33(4), december 2021 the effect of recipient 35 positive association between primary implant stability and localization (mandibular vs. maxillary), although, the authors reported an increased isq values between insertion and exposure (secondary stability) which was significantly correlated with healing time and was higher in the maxilla. the isq values of the secondary stability and after functional loading were higher for all dis in comparison to isq0 and isq8 irrespective to the recipient jaw. the results are in agreement with other authors (19) who found no substantial effect of di site with respect to its bone quality on secondary stability. the higher post functional loading implant stability in comparison with the other time points of measurement that was reported in this study, was also observed by other authors, who stated that loading of dental implants increases the secondary stability of the implants as well as the mineralization of peri-implant bone, and that the main effective factor was the time from implant insertion to post functional loading (20, 21). this could be explained by wolff’s law, which states that the bone will remodel itself and increase its firmness in response to mechanical stimulation and repeated load (22). in this study, wider implants had better effect on implant stability throughout the study period with significant difference of both isq12 and isqpfl time points, a finding that was also supported by other studies; gomez-polo et al., (19) in their longitudinal clinical study, evaluated the effect of dis with 3.75 and 4.25mm diameter on isq. they concluded that wider diameter implants had a positive effect on both primary and secondary stability. han et al., (14) on the other hand, observed no significant difference between dis with 4.1 and 4.8mm implant diameter. the diameter of dental implant is one of the factors that affect the stress distribution, especially, in the cervical portion of the di. studies have shown that wider implants result in better distribution of the masticatory forces (23). accordingly, the success of posterior implants is related to the increased surface area therefore, wide-diameter and long dis are recommended in the posterior region (24). in the present study, the implant diameter proved to be an influential factor, where lower stability was recorded in dis with a narrower diameter which is in line with other studies (19). whereas other investigators found significant relation between implant diameter and primary stability only, (18, 25, 26) others found the significant effect was on secondary stability only (27). analyzing the effect of di length on implant stability revealed that there was no significant relation between implant length and stability throughout the study period. although some studies have reported that shorter implants have less contact with the surrounding bone, which may result in lower implant stability. (28, 29) the literature reports inconsistent results with respect to the relationship between implant stability and implant length. ghanem et al. (1) reported direct effect of implant length on the stability and osseointegration of implants inserted immediately into freshly extracted sockets. other studies demonstrated that the primary implant stability was only influenced positively by the implant length, (19, 26, 30) whereas rengo et al. (27) stated that only the secondary implant stability was affected by implant length. on the other hand, aragoneses et al. (31) reported a direct relationship between implants of a smaller length and greater isq values with this relation being most evident in maxilla. the main limitation of this study is related to its small sample size which can make obtaining relevant generalization difficult. conclusions in conclusion, all dis were osseointegrated and stable at the end of the study irrespective to the recipient jaw, also di with a wider diameter had better stability throughout the study whereas di length showed no significant effect on implant stability. references 1. ghanem wa, sadakah aa. effect of implant length on the stability and osseointegration of immediate implant. j oral maxillofac surg. 2016; 7:41–48. 2. raghavendra s, wood mc, taylor td. early wound healing around endosseous implants: a review of literature. int j oral maxillofac surg. 2005; 20: 425. 3. olate s, lyrio mcn, de moraes m, et al. influence of diameter and length of implant on early dental implant failure. j oral maxillofac surg. 2010; 68: 414-419. 4. quesada-garcía mp, prados-sánchez e, olmedogaya mv, et al. dental implant stability is influenced by implant diameter and localization and by use of plasma rich in growth factors. j oral maxillofac surg. 2012; 70: 2761-2767. 5. simmons de, maney p, teitelbaum ag, et al. comparative evaluation of the stability of two different dental implant designs and surgical protocols—a pilot study. int j implant dent. 2017; 3:16 j bagh college dentistry vol. 33(4), december 2021 the effect of recipient 36 6. lachmann s, laval jy, axmann d, et al. influence of implant geometry on primary insertion stability and simulated peri-implant bone loss: an in vitro study using resonance frequency analysis and damping capacity assessment. int j oral maxillofac implants. 2011;26(2):347-55. 7. kastala vh. methods to measure implant stability. j dent implant. 2018; 8:3-8. 8. romero-ruiz mm, gil-mur fj, ríos-santos jv, et al. influence of a novel surface of bioactive implants on osseointegration: a comparative and histomorphometric correlation and implant stability study in minipigs. int j mol sci. 2019; 20(9): 2307. 9. bafijari d, benedetti a, stamatoski a, et al. influence of resonance frequency analysis (rfa) measurements for successful osseointegration of dental implants during the healing period and its impact on implant assessed by osstell mentor device. open access maced j med sci. 2019; 7(23):4110-4115. 10. lioubavina-hack n, lang np, karring t. significance of primary stability for osseointegration of dental implants. clin oral implant res. 2006; 17: 244–250. 11. dawson a, chen s, buser d, et al. the sac classification in implant dentistry. berlin: quintessence 2009 12. sennerby l, meredith n. implant stability measurements using resonance frequency analysis: biological and biomechanical aspects and clinical implications. periodontol 2000. 2008; 47:51. 13. berglundh t, abrahamsson i, lang np, et al. de novo alveolar bone formation adjacent to endosseous implants. a model study in the dog. clin oral impl res. 2003; 14: 251-262. 14. han j, lulic m, lang np. factors influencing resonance frequency analysis assessed by osstell mentor during implant tissue integration: ii. implant surface modification and implant diameter. clin oral implants res. 2010; 21(6): 605-11. 15. koshy at, mathew ta, mathew n, et al. assessment of implant stability during various stages of healing placed immediately following extraction in an overdenture situation. j indian prosthodont soc. 2017; 17:74-9. 16. rosen, p.s., meredith, n., reynolds, m.a. case reports describing the "bump": a new phenomenon in implant healing. j implant adv clin dent. 2010; 2: 2737. 17. javed f, ahmed hb, crespi r, et al. role of primary stability for successful osseointegration of dental implants: factors of influence and evaluation. interv med appl sci. 2013; 5 (4): 162–167. 18. vollmer a, saravi b, lang g, et al. factors influencing primary and secondary implant stability a retrospective cohort study with 582 implants in 272 patients. appl sci. 2020; 10: 8084. 19. gómez-polo m, ortega r, gómez-polo c, et al. does length, diameter, or bone quality affect primary and secondary stability in self-tapping dental implants? j oral maxillofac surg. 2016; 74:1344-1353. 20. huang y, van dessel j, liang x, et al. effects of immediate and delayed loading on peri-implant trabecular structures: a cone beam ct evaluation. clin implant dent relat res. 2014; 16:873–883. 21. akoğlan m, tatli u, kurtoğlu c, et al. effects of different loading protocols on the secondary stability and peri-implant bone density of the single implants in the posterior maxilla. clin implant dent relat res. 2017; 19(4): 624-631. 22. frost hm. wolff’s law and bone’s structural adaptations to mechanical usage: an overview for clinicians. angle orthod. 1994; 64:175–88. 23. himmlova l, dostalova t, kacovsky a, et al. influence of implant length and diameter on stress distribution: a finite element analysis. j prosthet dent. 2004; 91:20-25. 24. winkler s, morris hf, ochi s. implant survival to 36 months as related to length and diameter. ann periodontol. 2000; 5:22-31. 25. sabeva e. comparison between the influence of implant diameter and implant length of the primary stability. scr sci med. 2018; 4(2):36-41. 26. nappo a, rengo c, pantaleo g, et al. influence of implant dimensions and position on implant stability: a prospective clinical study in maxilla using resonance frequency analysis. appl sci. 2019; 9: 860 27. rengo c, nappo a, pantaleo g, et al. influence of implant dimensions and position on primary and secondary implant stability: a prospective clinical study in the mandible using resonance frequency analysis. j osseointegr. 2020; 12(1): 34-38. 28. hong j, lim yj, park so. quantitative biomechanical analysis of the influence of the cortical bone and implant length on primary stability. clin oral implants res. 2012; 23(10):1193–7. 29. huang h-l, tsai m-t, su k-c, et al. relation between initial implant stability quotient and boneimplant contact percentage: an in vitro model study. oral surg oral med oral pathol oral radiol endod. 2013; 116(5): e356–61. 30. bataineh ab, al-dakes am. the influence of length of implant on primary stability: an in vitro study using resonance frequency analysis. j clin exp dent. 2017; 9(1): e1-6. 31. aragoneses jm, aragoneses j, brugal va, et al. relationship between implant length and implant stability of single-implant restorations: a 12-month follow-up clinical study. medicina. 2020; 56: 263 conflict of interest: none declared funding: none j bagh college dentistry vol. 33(4), december 2021 the effect of recipient 37 المستخلص طول تأثيرلتقييم نالدراسة كا هذه من الهدف .الطويل المدى على والنجاح العظم في الزرعة إلدماج إلزامي عامل األسنان هو زعات استقرار .وظيفيال التحميلوبعد الزرعة األولي استقرار على وموقعها في الفك العلوي او السفلي وقطرها الزرعة زرعة 22زراعة االسنان لوضع اتاء عمليجرعاما. تم ا 96و 24 بين أعمارهم تتراوح بدون اي تاريخ مرضي، مريضا 17 الدراسة هذه شملت الملتئمة بعد قلع االسنان لفترة ال تقل عن ستة اشهرلتعويض االسنان الخلفية المفقودة في كال الفكين. تم قياس االستقرار االولي تجاويففي ال قها في ووالثانوي لكل زرعة باالضافة الى قياس االستقرار بعد التحميل الوظيفي. تم تقييم تغير نمط استقرار الزرعات وعالقته بابعاد الزعات وم لفكين. ا لقيم فلساعلى بكثير من الفك اال علىكان هناك فرق كبير في قيم استقرار الزرعات طول فترة الدراسة، وكان استقرار الزرعات بالفك اال استقرارا من أكثرمليمتر 1.6القطر . وكانت الزرعات ذاتداللة احصائية لبقية الفترات الزمنيةاالولي فقط مع عدم وجود اي تاثير ذا ستقراراال .فلم تظهر النتائج اي تأثير له طول فترة الدراسة يمتر طول فترة الدراسة. اما بالنسبة لطول الزرعاتلم 3.3الزرعات ذات القطر كين عند رعات في كال الفاستقرار الززيادة من الفك االسفل مع أفضلكان علىلزرعات في الفك االاالولي لستقرار االاظهرت نتائج الدراسة ان .في حين لم يظهر الطول اي تاثير كبير على استقرار الزرعات ،استقرار أكثروكان القطر االوسع الدراسة.نهاية articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. tara f.doc j bagh college dentistry vol. 25(2), june 2013 dental anomalies associated orthodontics, pedodontics and preventive dentistry173 dental anomalies associated with malocclusion among 13 year old kurdish students tara a. rasheed, b.d.s., m.sc. (1) abstract background: the aim of this national oral health survey was to determine the prevalence of malocclusions due to some anomalies in the dentition among the 13 years old kurdish students in sulaimani intermediate school. materials and methods: the total sample was 950 (455 males and 495 females) which assessed by diagnostic set and special instrument. the clinical examination was mainly based on the definitions of björk et al. some variables were recorded as present or absent sometimes denoting the tooth or the teeth involved in malocclusion and their distribution according to the whole sample. results: the results showed that 1)the most common extracted tooth was the mandibular first molar (2.9%). 2) at this age group the most common partially erupted tooth was the maxillary canine (4.2%). 3) the most common unerupted tooth was the maxillary second molars. 4) the most common retained deciduous tooth was the maxillary canine (6.8%), then the maxillary second molars (5.4%).5) hypodontia as judged clinically was found in 2.1% of the sample affecting one or more permanent teeth. the most common congenitally missing tooth was the maxillary lateral incisor (0.9%), mandibular second premolars (0.4%), and then maxillary second premolar (0.2%). 6) 29.2 % of the sample had one or more rotated teeth. the most common rotated tooth was the mandibular second premolars (5.3%). 7). the sample showed 30.4% with one or more displaced teeth. the most common displaced tooth was the maxillary lateral incisor (8.8%), then the maxillary canine (7.2%). conclusion: at the age of 13 both males and females show large range of dental anomalies that are better to be controlled. keywords: anomalies, sulaimani, hypodontia, congenitally, deciduous. (j bagh coll dentistry 2013; 25(2):173-178). introduction sulaimani lies in the northern mountainous part of iraq. the main language of the inhabitant people is kurdish. the total population of sulaimani city is about 601,705 of whom 13,274 are 13 years of age. few orthodontic researches have been conducted in this part of iraq. while dental caries has been regarded as the major dental disease throughout the world, malocclusion is a close runner-up. the morphogenetic nature of most malocclusions assures us that this dentofacial problem will continue to demand the best that dentistry can offer for a long time, indeed ⁽¹⁾. clearly, there is a need for further epidemiological research aiming to increase the knowledge about the extent of demand for orthodontic treatment ⁽²⁾, therefore, it is of prime importance in diagnosis and treatment planning in orthodontics or for the development of any national preventive plan for malocclusion. a thorough investigation of the occurrence of these malocclusions among school children would be of major importance in the planning of orthodontic treatment in the public dental health service. this study was not designed to be carried out on subjects who are still in a mixed dentition stage of development because of the dynamic nature of the mixed dentition stage and because many problems of occlusion in that stage of development are self-correcting ⁽³⁾. (1)lecturer. department of preventive, orthodontics and pedodontics, college of dentistry/ university of sulaimani it is likewise important to carry out a comparison of the prevalence of malocclusion with different racial groups on an objective basis, since the information they would provide might well throw light on the causes of malocclusion ⁽⁴⁾. the few studies which have been published have dealt with selected sub-populations and it is therefore not known whether the results may be generalized to the total population. clearly, there is a need for further epidemiological research aiming to increase the knowledge about the prevalence and type of malocclusion as well as the extent of need and demand for orthodontic treatment ⁽²⁾. although the dental services in iraq have been in continuous development both in type of the service given and in the size and distribution of the service supplied ⁽⁵⁾, but studies devoted to identify the malocclusion problem in the iraqi population have been quite few ⁽⁶,⁷⁾. this study was designed to include a sample of (950) of one age group (13 year olds) selected by multi-stage sampling similar to ⁽⁸,⁹⁾ who performed an oral health national study in iraq. materials and methods 1. the sample this study was designed to include a sample of (950) of one age group (13 year olds) in sulaimani intermediate school selected by multi-stage sampling j bagh college dentistry vol. 25(2), june 2013 dental anomalies associated orthodontics, pedodontics and preventive dentistry174 2. instruments and equipment the following instruments and supplies were used: 1. plane mouth mirrors 2. millimeter graded vernier (inox, zurcher modell, dentaurum 042-751). 3. metric ruler 4. an instrument designed to measure tooth rotation and displacement modified from ⁽¹⁰⁾ and ⁽⁴⁾. it is 6.5 cm long and consists of two stainless steel rods of 1mm in diameter with rounded ends, and 15º angle between them. 3. method examination area: the students examined were seated in a chair with a high backrest with their head supported in an upright position and the examiner standing in front of the chair ⁽³ ¹¹⁾. clinical examination: anomalies in the dentition: these observations were assessments of the status of individual teeth. each tooth (and tooth space) is assessed for the conditions listed. relevant questions to the student may often be helpful in making differential diagnosis within this category of conditions ⁽³⁾. it involves: a. anomalies of eruption and development by the age of 13 years most of the students should have a full set of permanent teeth except for the third molars. 1. missing permanent teeth due to extraction or trauma (code: e): all missing permanent teeth were registered, even if a bridge or partial denture had replaced them. the presence of spacing, the contour of the underlying alveolar ridge, the caries-experience of present teeth and pertinent questions to the student usually allow a correct assessment of missing teeth due to extraction or trauma ⁽³⁾. 2. unerupted teeth (code: x): all unerupted permanent teeth, other than third molars, were registered. considering the students’ age canines and second molars might have not yet erupted and were recorded. other missing teeth were distinguished from congenitally absent teeth and missing due to extraction and trauma ⁽⁴⁾. 3. partially erupted teeth (code: p): a partially erupted tooth was considered as a tooth that had not reached the occlusal level. 4. retained deciduous teeth (code: d): any present deciduous teeth were recorded, whether the successor permanent tooth had erupted or not. 5. congenitally absent teeth: considering the student’s chronological and dental ages, those teeth that were assessed to be congenitally absent were entered under remarks. when the student gave a history of no previous extraction(s), and the contour of the underlying alveolar ridge did not indicate an impacted tooth, it was assumed that the tooth was congenitally absent ⁽³⁾. it was possible that missing teeth were mistaken for congenitally absent teeth in the absence of radiographic examination and vice versa, but only one of these items was registered. in case of doubt the entry was made under ‘missing tooth’ and under ‘remarks’ ⁽⁴⁾. b. anomalies of alignment 1. rotated teeth fully erupted teeth that were rotated more than 15º were registered under ‘mesial’ or ‘distal’ rotation. the degree of rotation was measured with the registration instrument ⁽⁴⁾. 2. displaced teeth any tooth displaced bodily from the ideal arch line by more than 1mm was registered under ‘buccal’ or ‘palatal’ displacement ⁽¹⁰⁾. results anomalies in the dentition 1. missing permanent teeth due to extraction or trauma: of the sample, 6.8% had one or more missing permanent teeth due to extraction or trauma. the most common extracted tooth was the mandibular first molar (2.9%), then the maxillary first molar (1.0%) (table 1). table 1: distribution of missing permanent teeth due to extraction or trauma of the whole sample. side right left tooth no. ◄7 ◄6 ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► 6► 7► maxillary n 0 11 0 0 0 0 0 1 0 0 0 0 90 1 % 0.0 1.1 0.0 0.0 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.0 0.9 0.1 mandibular n 0 29 1 0 0 0 0 0 0 0 1 2 27 1 % 0.0 3.0 0.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.2 2.8 0.1 j bagh college dentistry vol. 25(2), june 2013 dental anomalies associated orthodontics, pedodontics and preventive dentistry175 2. partially erupted teeth the most common partially erupted tooth was the maxillary canine (4.2%), then the maxillary second molars (2.3%), mandibular second molars (1.9%),and then maxillary second premolars (1.6%) (table 2). table 2: distribution of partially erupted teeth of the whole sample. side right left tooth no. ◄7 ◄6 ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► 6► 7► maxillary n 28 0 16 9 31 1 0 1 0 51 11 14 0 17 % 2.9 0.0 1.7 0.9 3.2 0.1 0.0 0.1 0.0 5.3 1.1 1.5 0.0 1.8 mandibular n 15 0 5 7 8 1 0 1 0 4 6 10 0 21 % 1.6 0.0 0.5 0.7 0.8 0.1 0.0 0.1 0.0 0.4 0.6 1.0 0.0 2.2 3. unerupted teeth the most common unerupted tooth was the maxillary second molars (10%), then the mandibular second molars (4.7%), maxillary canine (1.4%) ,and mandibular second premolars (1.2%) (table 3). table 3: distribution of still unerupted teeth of the whole sample. side right left tooth no. ◄7 ◄6 ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► 6► 7► maxillary n 96 0 8 0 15 0 0 0 0 12 0 4 1 95 % 10.1 0.0 0.8 0.0 1.6 0.0 0.0 0.0 0.0 1.2 0.0 0.4 0.1 10.0 mandibular n 51 0 12 1 1 0 0 0 0 1 2 11 1 39 % 5.3 0.0 1.3 0.1 0.1 0.0 0.0 0.0 0.0 0.0 0.2 1.1 0.1 4.1 4. retained deciduous teeth: of the sample 27.3% had retained deciduous teeth. the most common retained deciduous tooth was the maxillary canine (6.8%), then the maxillary second molars (5.4%), mandibular second molars (2.4%), and then both maxillary first molars (0.9%) with mandibular canines (0.9%) (table 4). table 4: distribution of retained deciduous teeth of the whole sample. side right left tooth no. ◄e ◄d ◄c ◄b ◄a a► b► c► d► e► maxillary n 52 11 68 0 0 0 0 62 7 50 % 5.5 1.1 7.1 0.0 0.0 0.0 0.0 6.5 0.7 5.3 mandibular n 30 8 6 0 0 0 1 10 3 17 % 3.1 0.8 0.6 0.0 0.0 0.0 0.1 1.0 0.3 1.8 5. congenitally absent teeth: hypodontia as judged clinically was found in 2.1% of the sample affecting one or more permanent teeth. the most common congenitally missing tooth was the maxillary lateral incisor (0.9%), mandibular second premolars (0.4%), and then maxillary second premolar (0.2%) (table 5). 6. rotated teeth: of the sample, 26.5 % were found to have one or more rotated teeth. the most common rotated tooth was the mandibular second premolars (5.3%), then mandibular canine (5.1%), maxillary canine (4.5%), and mandibular first premolars (2.8%) but the least rotated tooth was maxillary second premolars (0.5%) (table 6). j bagh college dentistry vol. 25(2), june 2013 dental anomalies associated orthodontics, pedodontics and preventive dentistry176 table 5: distribution of congenitally missing teeth of the whole sample side right left tooth no. ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► maxillary n 1 1 0 8 0 0 11 0 2 3 % 0.1 0.1 0.0 0.8 0.0 0.0 1.1 0.0 0.2 0.3 mandibular n 5 1 0 0 0 1 1 0 0 3 % 0.5 0.1 0.0 0.0 0.0 0.1 0.1 0.0 0.0 0.3 * these numbers are of only the teeth that were surely congenitally missing by clinical examination and history. table 6: distribution of rotated teeth of the whole sample. side right left tooth no. ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► maxillary n 4 9 48 21 19 20 23 38 8 6 % 0.4 0.9 5.0 2.2 2.0 2.1 2.4 4.0 0.8 0.6 mandibular n 47 30 48 13 10 9 21 51 25 55 % 4.9 3.1 5.0 1.4 1.0 0.9 2.2 5.3 2.6 5.7 7. displaced teeth: of the sample, 28.6% were found to have one or more displaced teeth. the most common displaced tooth was the maxillary lateral incisor (9.8%) then the maxillary canine (7.5%) , mandibular canine (3.7%), and mandibular laterals (2.3%), while the least commonly displaced teeth were the maxillary first premolars (0.3%), maxillary second premolars (0.6%), maxillary central incisors (0.9%) and both the mandibular first premolar and the mandibular central incisor (1.1%) (table 7). table 7: distribution of buccally and palatally displaced teeth of the whole sample. direction of displacement side right left tooth no. ◄5 ◄4 ◄3 ◄2 ◄1 1► 2► 3► 4► 5► buccal maxillary n 0 2 65 49 7 4 46 62 2 1 % 0.0 0.2 6.8 5.1 0.7 0.4 4.8 6.5 0.2 0.1 mandibular n 8 7 30 10 9 11 3 25 9 7 % 0.8 0.7 3.1 1.0 0.9 1.1 0.3 2.6 0.9 0.7 palatal maxillary n 6 0 7 45 5 2 47 9 3 6 % 0.6 0.0 0.7 4.7 0.5 0.2 4.9 0.9 0.3 0.6 mandibular n 12 0 6 20 1 2 12 9 5 14 % 1.2 0.0 0.6 2.1 0.1 0.2 1.2 0.9 0.5 1.5 total maxillary n 6 2 72 94 12 6 93 71 5 7 % 0.6 0.2 7.6 9.9 1.2 0.6 9.8 7.4 0.5 0.7 mandibular n 20 7 36 30 10 13 15 34 14 21 % 2.1 0.7 3.8 3.1 1.0 1.3 1.6 3.6 1.5 2.2 j bagh college dentistry vol. 25(2), june 2013 dental anomalies associated orthodontics, pedodontics and preventive dentistry177 discussion anomalies in the dentition: a. anomalies of eruption and development: in the present study, 6.8% of the sample had one or more missing teeth due to extraction or trauma. this was near to 6% of ⁽¹²⁾, 6% of the 13 year old sample of ⁽¹³⁾ and 7.3% of ⁽⁹⁾, while it was much lower than 9.8% of ⁽¹⁴⁾ and 10% of the 13 year old sample of ⁽⁷⁾. the most common extracted tooth was the mandibular first molar (2.9%), then the maxillary first molar (1.0%). this is in near to the findings of ⁽¹⁵,¹⁶,⁹⁾. cons et al ⁽¹⁷⁾ found that 3.22% of their 15-18 year old sample had one or more retained deciduous teeth mostly involving single teeth. this was much lower than that found in this study (27.3%) because of the older age of the former study. the most common retained deciduous tooth was the maxillary canine and then the deciduous second molars. this may be because of their late eruption time and the high congenital absence of the second premolars as found by ⁽¹⁸⁾ which was 2% for the mandibular and 1.1% for the maxillary. hypodontia was found in 2.1% of the present sample and it was low when compared to the 5% found by⁽¹⁹⁾ among orthodontic patients or the 3.36% found by ⁽¹⁸⁾among the medical technology institute students, while near to the findings of ⁽⁹⁾. the most common congenitally missing tooth was the maxillary lateral incisor, then the mandibular second premolar, maxillary second premolar. this finding disagrees with those of ⁽²⁰ ²¹ ²² ²³ ²⁴ ²⁵²⁶⁶ ¹⁸⁾ who found the mandibular second premolar to be the most prevalent followed the maxillary lateral incisor. on the other hand, our finding comes in coincidence with that of ⁽²⁷ ²⁸ ²⁹ ³⁰ ³¹ ³² ¹⁹ ⁹⁾. anomalies of alignment: a. rotated teeth: in this study, 26.5 % had one or more rotated teeth (>15˚). this prevalence was lower than that found by ⁽¹⁰ ⁷ ¹³ ³³ ³⁴⁾, while near to⁽⁹⁾. it is difficult to compare our result with those of many other previous studies because of differences in the definition and criteria used. the most common rotated tooth were the mandibular second premolars then mandibular canine, and maxillary canine which were in reverse to the readings of ⁽⁹⁾ that showed mandibular canine as the most common rotated tooth then the mandibular second premolar. b. displaced teeth: in this study 28.6% had one or more displaced teeth (>1mm). this prevalence was remarkably more than the 14.5% and 13.5% found by ⁽⁷ ¹³⁾ in their 13 year old samples. this finding is also higher than that found by ⁽¹⁰⁾ and this may be explained by differences in definition and criteria used as ⁽¹⁰⁾ recorded only displacements more than 1.5mm.the findings near to that of ⁽⁹⁾ that had the same criteria of the sample. the most common buccally displaced tooth was the maxillary canine (6.8% on the right and 6.5% on the left sides) that near to the findings of ⁽⁹⁾ while it was lower than the finding of ⁽³⁵⁾ who examined 2851 iraqi 13-14 year olds to find that 8.3% of them had one or two buccally malposed canines. the most common palatally displaced tooth was the maxillary lateral incisor (4.7% on the right and 4.9% on the left sides). this is due to the developmental position of the maxillary lateral incisor germ palatal to the roots of the central incisors ⁽³⁶⁾. the results were also near to ⁽⁹⁾. the conclusions from this study were: 1. 6.8% of the sample had one or more missing permanent teeth due to extraction or trauma. 2. hypodontia was found in 2.1% of the sample affecting one or more permanent teeth. 3. from the whole sample 26.5 % were found to have one or more rotated teeth. the most common rotated tooth was the mandibular second premolars, while the displaced teeth were in 28.6% that have one or more displaced teeth. the most common displaced tooth was the maxillary lateral incisor 4. at the age of 13 both males and females show large range of dental anomalies that are better to be controlled. references 1. graber tm. orthodontics: principles and practice. 3rd ed. philadelphia: wb saunders co.; 1988 2. salonen l, mohlin b, götzlinger b, helldén l. need and demand for orthodontic treatment in an adult swedish population. eur j orthod 1992; 14(5): 35968. 3. baume lj, horowitz hs, summers cj, backer dirks o, carlos jp, cohen lk. a method for measuring occlusal traits developed by the fdi commission on classification and statistics for oral conditions. int dent j 1973; 23: 530-7. 4. björk a, krebs åa, solow b. a method for epidemiological registration of malocclusion. acta odontol scand 1964; 22: 27-41. 5. ministry of health. health status in iraq. the directorate of planning and administrable development. ministry of health, baghdad; 1998. 6. kinaan bk. overjet and overbite distribution and correlation: a comparative epidemiological englishiraqi study. brit j orthod 1986; 13: 79-86. j bagh college dentistry vol. 25(2), june 2013 dental anomalies associated orthodontics, pedodontics and preventive dentistry178 7. abdulla nm. occlusal features and perception: a sample of 13-17 years old adolescents. master thesis, college of dentistry, university of baghdad, 1996. 8. alazawi la. oral health status and treatment needs among iraqi five years old kindergarten children and fifteen years old students: a national survey. ph.d. thesis, college of dentistry, university of baghdad, 2000. 9. al-huwaizi af. occlusal features, perception of occlusion, orthodontic treatment need and demand among 13 year old iraqi students. ph.d. thesis, college of dentistry, university of baghdad, 2002. 10. van kirk le jr, pennell eh. assessment of malocclusion in population groups. am j orthod 1959; 45(10): 752-8. 11. world health organization. oral health surveys: basic methods. 4th ed. geneva: who, the organization; 1997. 12. garner ld, butt mh. malocclusion in black americans and nyeri kenyans. an epidemiologic study. angle orthod 1985; 55(2): 139-46. 13. batayine fam. occlusal features and perception of occlusion of jordanian adolescents: a comparative study with an iraqi sample. master thesis, college of dentistry, university of baghdad, 1997. 14. schaschula rg, cooper mh, wright mc, agus hm, un psh. oral health of adolescent and adult australian aborigines. community dent oral epidemiol 1980; 8: 370-4. 15. massler m, frankel jm. prevalence of malocclusion in children aged 14 to 18 years. am j orthod 1951; 37: 751-68. 16. al-makadsi fb, al-sahar wf. a study of posterior tooth loss in 15 year old iraqi students. iraq dent j 1985; 12: 155-164. 17. cons nc, mruthyunjaya yc, pollard st. distribution of occlusal traits in a sample of 1337 children aged 1518 residing in upstate new york. int dent j 1978; 28(2): 154-64. 18. al-mulla aa, mahdi ts, hamid nh. incidence of hypodontia of permanent teeth. iraq j medical technology 1990; 7: 69-80. 19. kinaan bk. characteristics and management of hypodontia in iraqi orthodontic patients. iraqi dent j 1985; 12: 133-143. 20. dolder e. deficient dentition. dent rec 1937; 57: 142-3. 21. byrd ed. incidence of supernumerary and congenitally missing teeth. j dent child 1943; 10: 846. 22. brown rv. the pattern and frequency of congenital absence of teeth. iowa state dent j 1957; 43: 60-1. 23. gysel g. anodontie, oligodontie, hypodontie. orthodontie francnise 1957; 32: 403-13. 24. rose js. a survey of congenitally missing teeth, excluding third molars in 6000 orthodontic patients. dent pract dent res 1966; 17: 107-14. 25. monteil m. contributional, etude et autraitment del agenesis dela dent permenente. the 3 eme cycle sci odont. paris vii; 1968. 26. al-mulla aah. a study of hypodontia of permanent teeth. doctoral thesis, college of dentistry, university of paris vii; 1986. 27. werther a, rothenberg f. anodontia. am j orthod 1939; 25: 61-81. 28. reitan k. clige et anodontie. den norske t mars 1953; 65-77. 29. rosenzweig ka, garbaski d. numerical aberrations in the permanent teeth of grade school children in jerusalem. am j phys anthropol 1965; 23: 277-83. 30. castaldi cr, bodnarchuk a, macrae pd, zacherl wa. incidence of congenital anomalies in permanent teeth of a group of canadian children aged 6-9 years. j can dent assoc 1966; 32: 154-9. 31. muller tp, hill in, patersen ac, blayney jr. a summary of congenitally missing permanent teeth. j am dent assoc 1970; 81: 101-7. 32. baume bj, cohen mm. studies of agenesis in the permanent dentition. am j phys anthropol 1971; 35: 125-8. 33. helm s. malocclusion in danish children with adolescent dentition: an epidemiologic study. am j orthod 1968; 54: 356-66. 34. hoffding j, kisling e. premature loss of primary teeth: part i: its over all effect on occlusion and space in the permanent dentition. asdc j dent child;1978. 35. ghaib nh. buccally malposed canines: a survey of school children aged 13-14 years. master thesis, college of dentistry, university of baghdad, 1992. 36. walther dp. walther’s orthodontic notes. 1st ed. bristol: wright psg; 1960. j bagh college dentistry vol. 29(1), march 2017 assessment of restorative dentistry 32 assessment of calcium carbonate coating on osseointegration of commercially pure titanium implant by torque removal test and histomorphometric analysis mustafa s. mahmood, b.d.s. (1) shatha s. al-ameer, b.d.s., m.sc. (2) abstract background: one of the most important methods to replace lost teeth is dental implants. in order to increase the strength of connection of the implant with the jaw bone to provide early loading after placement, implant is coated by different coating materials that achieved that purpose. the aim of this study was to evaluate the influence of coating cp ti implant with calcium carbonate on the strength of bone-implant interface after two and six weeks of implantation in rabbit femur bone by torque removal test, histological and histomorphometric analysis. materials and methods: coating the surface of commercially pure titanium screws with extra pure synthetic calcium carbonate via electrophoretic deposition method (epd) was done. the surface of disc samples after coating was checked by optical microscopy, x-ray diffraction examination and measurement of coating thickness. ten male white french rabbits were prepared for implantation. forty screws were implanted in the femur bone, two implant screws in each femur bone. the first screw is coated with calcium carbonate and compared with the second uncoated screw. rabbits are divided into two groups according to the healing periods 2 and 6 weeks. by torque removal, the osseointegration is measured. single screw from each group was used for histological and histomorphometric analysis. results: there was significant increased mean torque removal for screws coated with calcium carbonate compared with uncoated screws. histological examination showed an increase in the growth of bone cells for coated screws, and the histomorphometric analysis showed an increase in new bone formation percent (nbfp). conclusion: coating the surface of the cp ti implant with calcium carbonate via electrophoretic deposition method had great effect in increasing the osseointegration than uncoated surface. keywords: calcium carbonate, commercially pure titanium, electrophoretic deposition method, histomorphometric. (j bagh coll dentistry 2017; 29(1):32-38) introduction nowadays and due to high rate of success, dental implant treatment becomes a well acceptable way for replacement missing teeth. the major factor for this success is the fact of osseointegration. (1) branemark in 1985 proposed that the osseointegration is “a direct structural and functional connection between ordered, living bone and the surface of a load-carrying implant”.(2) osseointegration is influenced by the type of biomaterial used as implant, surface texture, type of machining, surgical procedure, bone quality and quantity and prosthesis design.(3) titanium as a biomaterial is used for construction the implants. titanium is characterized by lightness and tolerance and has good chemical and mechanical properties makes it suitable for implant application. (4) (1) m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2) professor. department of prosthodontics, college of dentistry, university of baghdad. there is an interest in decreasing healing period following the implantation and the implant can be loaded safely by oral forces. modification was done to the implant surface such as coating by different materials and by different techniques, and/ or modifying the technique of surgery in order to reduce the time of healing.(3) one of the coating techniques is epd. it is cheap method due to the simplicity of the equipment and the capability of depositioning many micro or nano materials and their combinations. (5) calcium carbonate (caco3) is a restorable ceramic biomaterial that is gradually resorbed by the body.(6) because of structural similarity with bone, corals as a source of caco3 can be used for bone implants.(7) calcium carbonate has many medical uses, such as gastric anti-acid and nutritional calcium supplement. also it works as a phosphate binder and used to treat the hyperphosphatemia. in j bagh college dentistry vol. 29(1), march 2017 assessment of restorative dentistry 33 pharmaceutical manufacturing, caco3 can be utilized as inert filler for tablets.(8) in this study, an extra pure synthetic caco3 is deposited on cp ti screws by electrophoretic deposition method (epd) and implanted in rabbit femur and its effect on osseointegration is evaluated by torque removal test, histological and histomorphometric analysis after 2 and 6 weeks. materials and methods sample preparation grade 2 commercially pure titanium was used as a substrate for coating. by lathe machine, the titanium was cut into discs (2 mm thickness and 20 mm diameter). to have a uniform smooth surface, the discs were grinded using silicone carbide paper of 500 grit using a rotative grinding motion and polishing machine at 200 rpm for one minute. the titanium discs were cleaned by solution of (3ml nitric acid, 1ml hydrofluoric acid and 6ml distal water). then cleaning with ethanol alcohol using ultrasonic cleaner was done to eliminate any contamination and debris from the polished samples.(9) pilot study a. suspension preparation: the suspension was prepared by adding of caco3 powder to the ethanol as a solvent (100 g/1 liter) in a glass beaker and adding iodine as a charging agent (2 g/l). by using a stirrer, the stirring was continued until a colloidal suspension was obtained. the suspension was maintained at room temperature for 48 hrs. b. electrophoretic deposition process: cathode electrode from power supply was connected to the cp ti and anode electrode to a stainless steel plate. the distance between the electrodes was 1 cm. in order to select a proper voltage for the coating procedure, the power supply was used with different applied voltage (40, 50 and 60 v) for different time durations (0.25, 0.5, 1, 2 and 3 minutes. c. heat treatment: the coated specimens were densificated by sintering via tube furnace. sintering is performed under argon gas (inert gas) in order to avoid oxidation of the specimen. caco3 coated specimens were sintered to (400, 500 and 600) °c to select the proper heat temperature. best results were obtained at 400°c for 1 hr. without loss of parts of coating and without cracks. examination of surfaces a. microscopical examination: the samples coating was examined by using optical microscope (mti corporation, usa) to examine the appearance of the coated surface of the sample. the micrographs were examined by a software in a computer. b. x-ray phase analysis: phase analysis was utilized on the coated disc samples using shimadzu 6000x-ray diffractometer using a cu as target radiation at wave of 1.5406 a. continuous scan with axis of 2 ø angles were swept from 1070° in step of 0.05 degree. implant preparation: forty screws shaped implant were machined from the titanium bar using lathe machine. the screw length was 8mm (3mm flat part and 5mm threaded part) and 3 mm in diameter. the height and width of the pitch is 1mm to fit the screwdriver during insertion and removal.(10) the screws were cleaned as mentioned in sample preparation. the screws were divided into two groups, each group consisted of twenty screws. the first group of screws was the control, and the second group was coated with calcium carbonate for 0.5 min at 60 v as the same procedure of epd that was performed on disc samples. the caco3 coated screws were densificated by sintering to 400oc for 1 hr. under argon gas. the screws were then sterilized with a physical mean of sterilization by gamma radiation (figure 1). figure 1: (a) uncoated implant screws. (b) coated implant screws with caco3. animal and surgical procedures a b j bagh college dentistry vol. 29(1), march 2017 assessment of restorative dentistry 34 ten healthy adult male french rabbits weighing 1.5 1.75 kg (10-12 months of age) were used. three days before operation, subcutaneous ivermectin injection (0.2 ml) was given to eradicate the internal and external parasite. intramuscular injection of an antibiotic (ceftriaxone) was given once daily (0.5ml) for 3 days to avoid any infection. the rabbits were divided into two groups for 2 and 6 weeks healing periods, each group contained of five rabbits, one of them was killed for histological investigation using one leg and other leg for mechanical test, while the other four rabbits were used for mechanical test (torque removal test). two screws were implanted in each femur of each rabbit (1 uncoated screw and 1 caco3 coated screw for each femur bone). general anesthesia was given to the animal by intramuscular injection of xylazine (0.7 ml/kg body weight) and ketamine 10% (0.5 ml/kg body weight). if the animal wake up during the operation, isoflurane anesthetic inhalation was used (isoflurane 1 bar with oxygen 1.5 bar). the surgical instruments, gauze and towels were sterilized by autoclave at temperature of 134 c˚ at 2 bar for 3.5 minutes. both femurs were shaved using spray hair removal from outer side. before placing the sterilized towel around the operation site, the skin was sterilized with alcohol and iodine. the incision was made on the lateral side, the skin and fascia was reflected, and blind dissection was made to the muscle to expose the distal side of the femur bone. a round bur of 1.3 mm in diameter was used for bone penetration. two holes with 1cm distance between them was made. the penetration was done by intermittent pressure at a rotary speed of 1500 rpm and reduction ratio of 16:1, and continuous irrigation with normal saline for cooling. then the holes were enlarged gradually with fissure burs to 2.31 mm. caco3 coated screw was implanted in the first upper hole via screwdriver until the screw was introduced completely into the bone. the uncoated screw was placed in the second hole. suturing of muscle’s fascia was done with absorbable polydioxanone suture and the skin was sutured with silk suture. rabbits then were followed for 2 and 6 weeks. mechanical testing (torque test) the same anesthetic solutions, instruments and materials were utilized as in the implantation procedure. the rabbits were anesthetized and incision was made on the lateral side and the skin, fascia and muscle were reflected to expose the implant. torque measurement was performed by digital torque meter (tq-8800, taiwan) after supporting the femur bone to prevent any movement that may affect the test accuracy. after the screwdriver of the torque meter was engaged in the slit of the implant head, a torsional force was exerted for unscrewing the implant and the value was measured in newton centimeters (n.cm). histological testing one leg of one animal from each group of healing intervals was used for histological test. the animal was anesthetized with overdose of isoflurane general anesthesia. the bone around the implant was cut by a disc cutter via prosthetic engine with straight hand piece (strong 90, korea) with slow speed of rotation and normal saline irrigation. bone-implant block was obtained by cutting about ½ cm away from the implant screw. the blocks were stored in 10% formalin for at least three days for fixation. after preparation the slides, a light microscope (pro.way, china) was used and photographs of the sections were taken at 4, 10, 20 and 40 power magnification. histomorphometric analysis new bone formation percent (nbfp) measurement was performed using fiji imagej program (version 1.50b). first, the section diameter was measured and the mean value was inserted in the set scale box with the diameter of the screw. these values will be saved in the program as a data used to measure the area. then the new bone areas were outlined and measured. the new bone formation percent (nbfp) was calculated according to the following formula: (11) (12) nbfp% = area of newly formed bone total tissue area ×100 results x-ray diffraction of coated samples the 2 ø angles were swept from 1070° in step of 0.05 degree. according to the (jcpds), the j bagh college dentistry vol. 29(1), march 2017 assessment of restorative dentistry 35 peak index was determined. international card for diffraction data (icdd) pdf file # 44-1294 for titanium, # 11-0218 for ti2o and # 29-0305 for caco3. after epd (within 0.5 min. at 60v), as in figure 2 the sample surface is seen completely coated with caco3, because the diffraction peak was indexed to caco3 phase matching the jcpds file # 29-0305 for caco3. figure 2: x-ray diffraction patterns of caco3 coated cp ti sample using epd technique clinical observation after healing period interval, at the time the animals are killed, the tissue surrounding the implant has negative clinical observation without any signs of severe infections. stability of implants after each healing period was indicated by inability to remove the implant with manual force. mechanical testing after 2 and 6 weeks of healing periods, caco3 coated implants needed higher torque values to remove them, (mean value for 2 weeks: 4.6 n.cm & for 6 weeks: 12.7 n.cm), while uncoated implants needed less torque values (mean value for 2 weeks: 2.7 n.cm & for 6 weeks: 10.4 n.cm) (table 1). table 1: comparison of mean torque value of caco3 coated and uncoated implants between both healing periods (n.cm) types time n mean + s.d. range control 2 wks 9 2.711 + 0.853 1.5-4.0 6 wks 9 10.477 + 0.580 8.8-13.2 coated 2 wks 9 4.688 + 1.118 3.2-6.2 6 wks 9 12.777 + 1.504 9.8-14.6 t-test for equality of means of torque values between caco3 coated and uncoated implants after 2 weeks of healing periods showed a highly significant difference at p≤0.001 and after 6 weeks of healing periods showed a significant difference at p≤0.05 (tables 2, 3). table 2: t-test for equality of means of torque value for caco3 coated and uncoated implants after 2 weeks of healing period types t df p-value sig. coated & uncoated 4.217 16 0.001 hs hs: highly significant at p≤0.001 table 3: t-test for equality of means of torque value for caco3 coated and uncoated implants after 6 weeks of healing period types t df p-value sig. coated & uncoated 3.162 16 0.006 s s: significant at p≤0.05 t-test was also done to test the equality of means showed a highly significant differences at p≤0.001 between uncoated and coated groups at two period intervals (table 4). table 4: t-test for equality of means of torque removal value for uncoated and coated implants at 2 and 6 weeks intervals types time t df p-value sig. uncoated 2x6 wks 12.973 16 0.000 hs coated 2x6 wks 12.942 16 0.000 hs hs: highly significant at p≤0.001 histological features the histological feature of uncoated implants in the thread area after two weeks of implantation showed new bone trabeculae (bt) formation filled j bagh college dentistry vol. 29(1), march 2017 assessment of restorative dentistry 36 the thread area. in addition, the histological feature showed active osteoblasts (ob) surrounding the periphery of bt, some of these cells are trapped in bone matrix as pre-osteocytes (pos) and then converted to osteocytes (os). also osteoclast are present (figure 3). while histological findings of implants coated with caco3 showed new bone formation surrounding the screw space. new bone trabeculae in the thread area are filled with new osteocytes (os) and lined by osteoblast cells (ob). the reversal line separate between new and old bone. the new bone area shows woven bone (immature bone) filled with large number of osteocytes (figure 4). figure 3: microscopic view of uncoated implant after 2 weeks. osteoblasts (ob), pre-osteocytes (pos), osteocytes (os) & osteoclast (ocl). h & e ×40. figure 4: microscopic view of caco3 coated implant after 2 weeks shows new bone trabeculae in thread area filled with new osteocytes (os) lined by osteoblast (ob). reversal line (yellow arrow). woven bone (green arrow) filled with osteocytes (os). h & e ×40. the thread area of uncoated implant after six weeks of implantation showed dense bone trabeculae (bt) filled with osteocytes (os) surrounded by osteoblasts (ob) and osteoclasts (ocl) (figure 5). while microscopic views for the coated implants with caco3 shows active process of bone development, indicated by the active osteocytes arranged in circular pattern around haversian canal (osteon formation) (figure 6). figure 5: microscopic view of uncoated implant after 6 weeks. dense bone trabeculae (bt). osteoblasts (ob). osteoclasts (ocl). haversian canal (black arrow). h & e ×20. figure 6: microscopic view of coated implant after 6 weeks. lamellae (osteon formation) (yellow arrow). haversian canal (black arrow). osteoblasts (ob). osteocytes (os). h & e ×20. histomorphometric analysis the new bone formation percent (nbfp) of the caco3 coated implants in rabbit femur was greater than that of uncoated implants after 6 weeks of implantation. the mean of nbfp of caco3 coated implants was 4.71 and for uncoated was 3.65 (table 5). b o n e t ra b e c u la e ob j bagh college dentistry vol. 29(1), march 2017 assessment of restorative dentistry 37 table 5: descriptive analysis of nbfp of caco3 coated and uncoated groups after 6 weeks of healing period types n mean s.d. range control 30 3.652 + 0.557 2.5-4.9 coated 30 4.710 + 0.853 3.2-6.2 t-test for equality of means of nbfp values between caco3 coated and uncoated implants after 6 weeks of healing period showed a highly significant difference (table 6). table 6: t-test for equality of means of nbfp for caco3 coated and uncoated implants after 6 weeks of healing period types t df p-value sig. coated & uncoated 5.685 58 0.000 hs hs: highly significant at p≤0.001 discussion the purpose of surface implant treatment is to promote the osseointegration mechanism with stronger and faster bone formation, so better stability during the healing process is achieved permitting more rapid loading of the implant.(13) calcium carbonate is a biocompatible material that affects positively on the bone regeneration, osteogenesis and strengthening of the bone. it has been used as bone substitutes for high-speed bone resorption and for osteoconductive quality.(14) effect of calcium carbonate coating mechanical testing: the caco3 coated cp ti screws placed in rabbit femur bone recorded a higher mean of removal torque value than uncoated screws after 2 and 6 weeks of implantation. this means caco3 stimulated bone formation in which bond strength at the bone-implant interface was increased. the positive role of calcium carbonate coating is dependent on calcium ions. as the caco3 is a source of calcium, so increased amount of ca may accelerate integrin-mediated attachment of boneforming cells through enhanced ligand binding of receptor.(15) ca has a positive effect on osseointegration by accelerating osteoblast proliferation, differentiation and adhesion after implantation.(16) in addition, carbonate phase of caco3 is required for initiation of bone formation. carbonate ions increase bioactivity and may be related directly to the process of dissolutionprecipitation cycles that takes place during regeneration of bone tissue.(17) carbonate ion substitutions have two types that occur in two atomic positions in the apatite lattice (type a & b). type (a) substitution occurs when co3 2 substitutes for hydroxyl (oh–) ions, and type (b) substitution occurs when co3 2substitutes for phosphate (po4 3-) ions. (18) histological findings: histological features of uncoated cp ti implant in femur bone after 2 weeks of implantation showed formation of primitive new bone near the surface of the implant. the new bone trabeculae were filled with active osteoblast cells which indicated the starting of bone formation. while the histological feature of coated implant showed many trabeculae of woven bone which were lined by bone forming cell (osteoblast) indicating active bone trabeculae formation. the bone trabeculae filled the thread region in the coated implant were thicker than that in the uncoated implant which indicate early bone stimulation. microscopical observation after 6 weeks of implantation revealed that the woven bone started to be replaced by lamellar bone to provide sufficient strength for load bearing. (19) in microscopical observation for uncoated implant, the thread still show immature bone filling (bone remodeling), while for coated implant showed more osteon formation (haversian system) and beginning for the concentric arrangement of bone lamellae with their contained osteocytes, which indicate mature bone formation. histomorphometric analysis: histomorphometric measurement is an invasive method used to test the nature of the implant-tissue surface. it is used for several studies to evaluate the bone implant interface.(20) bone formation percent after 6 weeks of implantation was higher in caco3 coated implant than uncoated implants. high bone formation percent after 6 weeks may be attributed to the activation of the caco3 implant to the tissue at the interface at early stage and continuing of bone activation through the 6 weeks of implantation. the growth and quality of newly formed bone tissue is affected by the surface properties of biomaterials that are necessary to the cells response at biomaterial interface.(21) as conclusion; coating the surface of the cp ti implant with calcium carbonate via electrophoretic deposition method had great effect in increasing the osseointegration than uncoated surface. j bagh college dentistry vol. 29(1), march 2017 assessment of restorative dentistry 38 references 1. goutam m, chandu gs, mishra sk, singh m, tomar bs. factors affecting osseointegration: a literature review. j orofac res 2013; 3(3):197-201. 2. chaiy r, qing l, wei l, appleyard r, swain m. effect of fully porouscoated (fpc) technique on osseointegration of dental implants. adv mater res 2008; 32:189-192. 3. elias c n. factors affecting the success of dental implants. in implant dentistry a rapidly evolving practice; turkyilmaz i. intech 2011: 319-364. 4. wong j y & bronzino j d. biomaterials. new york, crc press 2007. 5. de riccardis m f. ceramic coatings obtained by electrophoretic deposition: fundamentals, models, post-deposition processes and applications. in ceramic coatings applications in engineering; shi f. intech 2012: 43-68. 6. khavari f & bajpai p k. coralline-sulfate bone substitutes. biomed sci instrum 1993; 29: 65-69. 7. damien e & revell p a. coralline hydroxyapatite bone graft substitute: a review of experimental studies and biomedical applications. j appl biomater biomech 2004; 2(2):65-73. 8. lieberman h a, lachman l, schwartz j b. pharmaceutical dosage forms: tablets. 2nd ed. new york: dekker 1990: 153. 9. lampman s r. weld integrity and performance. usa, asm international 1997. 10. hamad t i. histological and mechanical evaluation of electrophoretic bioceramic deposition on ti-6al-7nb dental implants. a phd thesis, college of dentistry, university of baghdad 2007. 11. ott s m. histomorphometric measurements of bone turnover, mineralization and volume. clin j am soc nephrol 2008; 3(3):151-156. 12. baek s m, kim s g, lim s c. histomorphometric evaluation of new bone formation around a magnetic implant in dogs. implantology 2011; 15(1): 22-30. 13. beutner r, michael j, schwenzer b, scharnweber d. biological nano-functionalization of titanium-based biomaterial surfaces: a flexible toolbox. j r soc interface 2010; 7: 93-105. 14. hamza s, bouchemi m, slimane n, azari z. physical and chemical characterization of adsorbed protein onto gold electrode functionalized with tunisian coral and nacre. mater sci eng c mater biol appl 2013; 33(1): 537-42. 15. suh j y, jeung o c, choi b j, park j w. effects of a novel calcium titanate coating on the osseointegration of blasted endosseous implants in rabbit tibiae. clin oral implants res 2007; 18(3): 362-369. 16. park j w, suh j y, chung h j. effects of calcium ion incorporation on osteoblast gene expression in mc3t3-e1 cells cultured on microstructured titanium surfaces. j biomed mater res a 2008; 86(1):117-26. 17. porter a, patel n, brooks r, best s, rushton n, bonfield w. effect of carbonate substitution on the ultrastructural characteristics of hydroxyapatite implants. j mater sci mater med 2005; 16(10):899907. 18. kannan s, vieira si, olhero sm, torres pm, pina s, da cruz oa, ferreira jm. synthesis, mechanical and biological characterization of ionic doped carbonated hydroxyapatite/ β-tricalcium phosphate mixtures. acta biomater 2011; 7(4):1835-1843. 19. robert we, smith pk, zibermann y, mozary pg, smith r. osseous adaptation to continuous loading of rigid endosseous implant. am j orthod 1984; 86: 95111. 20. meredith n. on the clinical measurement of implant stability and osseointegration. a phd thesis. sweden: department of biomaterials, university of goteborg 1997:1-209. 21. von der mark k, park j, bauer s, schmuki p. nanoscale engineering of biomimetic surfaces: cues from the extracellular matrix. cell tissue res 2010; 339(1):131-153. الخالصة لفوري بعد وضع واحدة من أهم الطرق لتعويض األسنان المفقودة هي زراعة األسنان. وألجل زيادة قوة التصاق الزرعة مع عظم الفك من أجل توفير التحميل ا :الخلفية تقييم تأثير طالء سطح زرعة التيتانيوم التجاري النقي بمادة كاربونات الهدف من هذه الدراسة هو إن الزرعات، تُطلى الزرعة بمختلف مواد الطالء لتحقيق ذلك الغرض. التدوير والتحليل الكالسيوم ومدى قدرتها على زيادة قوة التصاق الزرعة بالعظم بعد أسبوعين وستة أسابيع من زراعتها في عظم فخذ األرنب بواسطة قياس عزم النسيجي. ية والتأكد طالء سطح براغي التيتانيوم التجاري النقي بمادة كاربونات الكالسيوم النقي الصناعي بطريقة الهجرة الكهربائية. تم فحص العينات المطلالبحث: المواد وطرق يات بيضاء اللون تم تحضيرها من طالئها بشكل موح د عن طريق الفحص المجهري الضوئي وفحص حيود األشعة السينية وقياس سمك الطالء. عشرة أرانب ذكور فرنس رانب إلى برغي في عظم الفخذ، برغيان في كل عظم. البرغي األول مطلي بكاربونات الكالسيوم ويقارن مع البرغي الثاني الخالي من الطالء. تقسم األ 04لزراعة ق البرغي بالعظم، ويُترك برغي واحد من كل مجموعة للفحص مجموعتين حسب مدة الشفاء )اسبوعان وستة أسابيع(. بواسطة فحص عزم التدوير تُقاس قوة التصا والتحليل النسيجي. يادة زيادة معدل عزم التدوير للبراغي المطلية بكاربونات الكالسيوم النقي الصناعي مقارنة مع البراغي غير المطلية. وأظهر الفحص النسيجي زنتائج الالنتائج: اظهرت ا التحليل النسيجي فقد أظهر زيادة في نمو الخاليا العظمية في البراغ معدل النمو العظمي.نسبة ي المطلية، أم ير مطلية.طالء سطح الزرعة بكاربونات الكالسيوم بطريقة الهجرة الكهربائية كان له تأثير كبير في زيادة ارتباط الزرعة بالعظم مقارنة مع زرعة غاالستنتاج: .جري الكهربائية، التحليل النسيجيالتيتانيوم التجاري النقي، طريقة الهكاربونات الكالسيوم، الكلمات الرئيسية: dropbox 13 israa 71-75.pdf simplify your life dr. shahba'a f.doc j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry155 the frontal sinus dimensions in mouth and nasal breathers in iraqi adult subjects iman i. al-sheakli, b.d.s., m.sc. (1) shahbaa a. mohammed, b.d.s., m.sc. (2) shaymaa sh. taha, b.d.s., m.sc. (2) abstract background: the frontal sinus area can be used as a diagnostic aid to recognize mouth breather subjects. the aims of this study were to determine the gender difference in each group, to compare the frontal sinus area between mouth breather and nasal breather group, and to verify the presence of correlation between the frontal sinus area and the cephalometric skeletal measurements used in this study. materials and methods: cephalometric radiographs were taken for 60 adults (30 mouth breathers and 30 nasal breathers) age range (18-25), for each group 15 males and 15 females, in the orthodontic clinic in the college of dentistry at baghdad university. the control group (nasal breather) with skeletal class i and anb angle ranged between 2-4º, and have clinically class i occlusion. the cephalometric measurement for each group were taken, the cephalometric radiographs were analyzed by using autocad 2007 program. results and conclusions: in comparison to nasal breather the mouth breather has larger gonial angle giving a tendency to posterior rotation with growth of the mandible. the mouth breather has less maxillary length than the nasal breather. no effect of gender in mouth breather on gonial, sna and snb angles, no effect of gender in nasal breather on gonial angle, while the other cephalometric measurements were higher in males than females in each group. the mouth breather showed more anteroposterior extent of anterior cranial base; also the mouth breather show an increase in all facial height than the nasal breathers, the frontal sinus area is smaller in mouth breather than in nasal breather. the frontal sinus area showed correlation for both groups (mouth and nasal breather) with maxillary length, mandibular length, ramal length, s-n length, tafh, uafh, lafh, tpfh, lpfh, and upfh. there is only correlation of frontal sinus with the sna and snb angles in nasal breather and no significant correlation for both groups with the gonial angle. keywords: frontal sinus, nasal breather, mouth breathers. (j bagh coll dentistry 2013; 25(2):155-163). introduction paranasal sinuses are filled spaces in the skull. these are subjected to individual variation and their x-ray appearance also depends on the degree of pneumatization. so we have frontal sinus, sphenoidal sinus, ethmoidal air cells, maxillary sinus, and nasopharyngeal space (1). the frontal sinus bud is present at birth in the ethmoid region but is not evident radiographically until the fifth year, when it projects above the orbital rim (2). rossouw et al have investigated the correlation between the frontal sinus size and mandibular growth prediction in subjects with class i and iii malocclusions. they concluded that the frontal sinus is a valuable indicator of excessive mandibular growth (3). rapid growth of the sinuses continues until the age of 12 years, when they reach nearly adult size (4). in a recent cephalometric investigation that used lateral head films, it was found that the frontal sinus development showed a growth rhythm similar to body height development, with a well-defined pubertal peak (5). (1) assistant professor, department of orthodontic, college of dentistry, baghdad university. (2) lecturer, department of orthodontic, college of dentistry, baghdad university. mouth breather subjects had tendency to possess skeletal class ii pattern with retruded mandible, more retrognathic facial type and more vertical growth (6). complete occlusion of one or both nasal passages occurs when unilateral or bilateral choanal atresia is present (7-9). the habit of breathing primarily through the oral cavity is named mouth breathing, which traditionally has been associated with some detrimental dentofacial changes and associated malocclusion (10). the frontal sinus enlargement has not been completely under stood. individual differences in the growth and desorption processes of the mucosa (11), the quality of the frontal bone which is to be pneumatized (12), the pressure of growing brain on the internal lamina of the frontal sinus area (13), the various pressure and hydrodynamic conditions of the end cranium of affecting the blood supply of the frontal sinus area (14), and hereditary factor (15). few researches were done on iraqi sample to study the frontal sinus. al-bustani studied the frontal sinus and skeletal jaw relation in iraqi cl i, cl ii and cl iii individuals (16). the aims of the present cephalometric study were to determine the gender difference in each group mouth and nasal breather, to compare the frontal sinus area between mouth breather and j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry156 nasal breather group, and to correlate the frontal sinus area with other cephalometric skeletal measurements in each group subjects. materials and methods sample pretreatment lateral cephalograms were taken of 60 untreated subjects (age 18-25 years old), 30 mouth breather patients (study samples) who was selected from patients who attended the center of ear, nose, throat, head and neck surgery in specialized surgery hospital in baghdad and 30 adult class i (control sample) who were selected from patients who attended the orthodontic clinic in the orthodontic department at the college of dentistry, university of baghdad. the mouth breather group was examined by ent specialist as having nasal obstruction or habitual mouth breather. the control group was examined by ent specialist as they were nasal breather, skeletal class i clinically and radio graphically (anb, 2-4º), they have class i occlusion by foster method (17-20). the patients should meet the following criteria, all the sample individuals should have full set of teeth except the wisdoms (21), the entire sample was of iraqi arab in origin, all had no previous orthodontic treatment, no previous orthodontic surgery, no history of thumb or digit sucking, no facial deformity and trauma, no any projection errors of radiograph and any other radiographic error such as blurred image, and no history of tonsillectomy or adenoidectomy or any other oral, nose and throat surgery. • the instruments include: kidney dish, dental mirrors, and sterilizer (memmert, germany) • the equipment include: the x-ray unit (the planmeca pro max x-ray unit) and analyzing equipment (dell portable computer and analyzing software (autocad 2007). method each individual was examined clinically and subjected to the digital true lateral cephalometric radiograph. the individual was positioned within the cephalostat with the sagittal plane of the head vertical, the frankfort plane horizontal, the teeth were in centric occlusion, and the patient in rest head position. every lateral cephalometric radiograph was analyzed by autocad program 2007 to calculate the angular, linear, and area measurements. once the picture was imported to the autocad program, it appeared in the master sheet on which the points and planes were determined, and then the measurements were obtained. the angles were measured directly as they were not affected by magnification while the linear measurement was divided by scale for each picture to overcome the magnification. cephalometric landmarks, planes and angles (figure 1) cephalometric landmarks 1. point s (sella): the midpoint of the hypophysial fossa (1). 2. point n (nasion): the most anterior point on the nasofrontal suture in the median plane (1). 3. point a (subspinale): the deepest midline point in the curved bony outline from the base to the alveolar process of the maxilla (1). 4. point b (supramentale): the most posterior point in the outer contour of the mandibular alveolar process in the median plane (1). 5. point me (menton): the most caudal point in the outline of the symphysis (1). 6. point go (gonion): a constructed point, the intersection of the lines tangent to the posterior margin of the ascending ramus and the mandibular base (1). 7. point ans (anterior nasal spine): it is the tip of the bony anterior nasal spine in the median plane (1). 8. point pns (posterior nasal spine): this is a constructed radiological point, the intersection of a continuation of the anterior wall of the pterygopalatine fossa and the floor of the nose. it marks the dorsal limit of the maxilla (1). 9. point ar (articulare): the point of intersection of the posterior margin of the ascending ramus and the outer margin of the cranial base (1). cephalometric planes and linear measurements (figure 2) 1. sella-nasion (sn) plane: it is the antero posterior extent of anterior cranial base (1,21). 2. maxillary base length: represents the extent of the maxillary base or it is a maxillary base length ans-pns (1). 3. mandibular base length: it represents the extent of mandibular base. the distance from gonion to the menton (1). 4. ramus length: this is represented by the distance gonion to articulare (1). 5. total anterior facial height (afh): it is the shortest distance between nasion and menton (21-23). 6. upper anterior facial height (uafh): the distance from nasion to anterior nasal spine (21,24,25). j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry157 7. lower anterior facial height (lafh): the shortest distance between anterior nasal spine and menton (1, 22-23). 8. total posterior facial height (pfh): the shortest distance between sella and gonion (22). 9. upper posterior facial height (upfh): formed by a line joining sella and posterior nasal spine (26,27). 10. lower posterior facial height (lpfh): formed by a line joining posterior nasal spine and gonion (27). angular measurements (figure 2): 1. gonial angle (ar-go-me): the angle formed between the posterior border of the ramus and the mandibular plane (1). 2. sna angle: the angle between lines s-n and n-a. it represents the angular antero-posterior position of the maxilla to the anterior cranial base (28, 29). 3. snb angle: the angle between lines s-n and n-b. it is the most commonly used measument for appraising antero-posterior disharmony of the jaw , it represents the antero-posterior position of the mandible in relation to anterior cranial base (28, 29). the frontal sinus area (mm2) (figure 2) the peripheral border of the frontal sinus was traced (5). statistical analysis all the data of the sample were subjected to computerized statistical analysis using spss version 15 (2006) computer program. the statistical analysis included: 1. descriptive statistics: mean, standard deviation (sd), and the statistical table. 2. inferential statistics: independent samplesttest: for the comparison between both groups and gender differences, and pearson's correlation test to test the correlation between frontal sinus area and the cephalometric variables that are used in this study. results and discussion the sample in this study was selected aged between 18 and 25 years old to minimize the effect of any remaining skeletal growth (30), and to get sample with complete frontal sinus growth (4) as the majority of facial growth is usually completed by 16-17 years of age (31). table (1) showed the descriptive statistic (mean and sd) in mouth breather group and the gender differences using the t-test, there was no significant difference between male and female in mouth breather group in the mean value of ga , sna and snb angles, which indicates that there is no effect of the gender in mouth breather on the direction of the growth of the mandible which represented by ga, and no effect of the gender in mouth breather group on the anteroposterior relation of the maxilla and the mandible to the anterior cranial base, this finding disagrees with al-labban (6) who found that the snaº was higher in males for both mouth breather and nasal breather group than in females. our result agrees with watson et al (32) who found that the magnitude of nasal resistance and subject’s anterior-posterior skeletal classification were independent from one to other. table (2) showed the descriptive statistics (mean and standard deviation) in nasal breather group and the gender difference, there is very high significant gender difference in all cephalometric measurements (except in the gonial angle), so the mean value of all cephalometric measurement were higher in males than in females due to the fact that males had larger facial dimensions than females(6), the gonial angle show no significant gender difference indicates that there is no effect of the gender in nasal breather on the direction of the growth of the mandible which represented by the ga. so the mean value of sna and snbº were higher in males of both group than in females this result agrees with watson et al (32) who found that the magnitude of nasal resistance and subject’s anterior-posterior skeletal classification were independent from one to other. table (3) showed the comparison between nasal breather and mouth breather group. frontal sinus: there is very high significant difference in frontal sinus area measurement between nasal breather and mouth breather group, the mean value of frontal sinus is larger in nasal breather than in mouth breather group, the factors contributing to sinus enlargement have not been completely under stood, however, individual differences in the growth, the quality of the frontal bone, hereditary and hormonal factors have been suggested to be responsible for sinus enlargement (33). some earlier studies suggested that increase in thickness in region of nasion was accounted for by enlargement of the frontal sinus (34). baer and harris (35) interpreted the development of the frontal sinus as process of structural adaptation to the forward and downward growth of the mid face with the forward growth of the external lamina of the frontal bone being essential to keep the contact with the nasal bone and the maxilla. one may logically assume in this research that small frontal sinus area in mouth breather group is may j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry158 be due to the less amount of air breathed enters the frontal sinus (from the nasal cavity) in mouth breather than that in the nasal breather group. the relationship between mouth breathing and unusual growth is well documented in orthodontic literatures (4,6). mouth breathing also causes a weakening of the muscles of facial structure leading to various orthodontic problems (28). also, this study found out that the frontal sinus is higher in males of both examined group, than in females, indicating that boys exhibited larger frontal sinus than that in girls (table 1 and 2). the gonial angle: the mean value of the gonial angle was higher on mouth breather than in nasal though it never reached the significant level, indicating that mouth breather subjects possessed large gonial angle, leading to more steeper mandibular angle and more tendency to posterior rotation(1). this result agrees with al-labban (6), and supported by harvold et al (36) who found that lowering the chin for oral respiration gradually resulted in steeper mandibular plane angle and more open gonial angle. also this finding coincided with cheng et al (37), who found that the shape and size of the mandible in breathing compromised subjects show significant differences from the control, our finding also agrees with kesso (21). the mean value of sna angle in our research is slightly higher in nasal breather than in mouth breather with no significant difference, this indicates that the nasal breather has slightly more prognathic maxilla relative to the anterior cranial base than the mouth breather group, so the maxilla was more retro-gnathic in the mouth breather group. this result agrees with other researchers cheng et al (37), subtently (38), bresolin et al (39). the mean value of snb angle in our research is slightly higher in nasal breather than in mouth breather with no significant difference, this agrees with ricketts (41) who found that the snb angle was less in the mouth breather. the mean value of maxillary length is higher in nasal breather than in mouth breather group with very high significant difference in female group, this finding agrees with al-labban(6) who found that this finding is due to bimaxillary retrognathism which is associated with mouth breathing habit. also this finding agrees with kesso (21). the mean value of mandibular length was found to be more in the mouth breather group than in nasal breather with high significant difference in females and no significant difference in males, this may be due to the fact that in mouth breather group the subject open their mouth and drop the mandible down to have adequate breathing through the mouth, this finding agrees with allaban (6), subtelny, and subtenly (42) and gureley (43). the mean value of ramus length was higher in mouth breather group than in nasal breather group with no significant difference in the male and high significant difference in females. the mean value of s-n length was found to be higher in mouth breather than in nasal breather, this comes in agreement with linder-aronson et al (44) and solow et al (45), who reported that nasal obstruction can also alter the air way and, subsequently, facial and cranial growth. the tafh, uafh and lafh, the higher mean value of these measurements in mouth breather group subjects may be due to the fact that the increased mandibular plane and mandibular maxillary angles in mouth breather lead to increase in afh (1-6) .the mouth breather termed vertical maxillary excess or long face syndrome(6) this finding agrees with al-labban(6). the higher mean value of pfh in mouth breather than that in nasal breathers which means that the nasal breather subjects have smaller posterior facial height, this finding disagrees with kesso (21) and al-labban(6). table (4) showed the correlation between frontal sinus and other variable in both groups. the frontal sinus in mouth and nasal breather group showed a very high significant correlation with facial height(except upfh in mouth breather group show significant correlation), s-n, ramus length, maxillary length and mandibular length, this finding agrees with rossuw et al (3), who show a strong correlation between the growth of the mandible and the frontal sinus dimension. the frontal sinus in our research has non-significant correlation with the sna and snb angles in mouth breather group, but has a very high significant correlation in nasal breather group this agrees with bresolin et al (39) who studied both nose and mouth breathers with allergic rhinitis. the frontal sinus has no significant correlation in our research with the gonial angle in both mouth breather and nasal breather group, this finding agrees with prashar et al (46) they found that the poor correlation of frontal sinus with gonial angle suggested that large frontal sinus may be present with large mandible irrespective of its growth direction, or the form of the mandible, with reference to the relation between body and ramus. our research of frontal sinus area in nasal and mouth breather group is new in iraqi population so we might expect more researches on frontal sinus dimension in the future. j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry159 the conclusions that can be drawn from this research were: 1. the frontal sinus area is smaller in mouth breather than in nasal breather group, and it is larger in males than females in each group. 2. the frontal sinus in mouth breather and nasal breather group is correlated with the facial height, s-n l, ramus l, max l and mand l. but not correlated in mouth breather with the ga, sna and snb angles and not correlated in nasal breather with ga. 3. the mouth breather group has higher ga (giving tendency to posterior rotation with growth of mandible), afh, pfh, mandibular length, ramus length, and s-n length than nasal breather groups. 4. the mouth breather group has less maxillary length than nasal breather group. table 1: the means and standard deviation of mouth breathers variables gender descriptive statistics gender difference d.f.=28 mean s.d. t-test p-value ga total 126.94 3.02 -0.33 0.744 (ns) male 126.78 3.78 female 127.13 1.96 sna total 82.47 2.19 0.70 0.486 (ns) male 82.72 2.05 female 82.19 2.37 snb total 78.82 1.78 0.80 0.429 (ns) male 79.06 1.89 female 78.56 1.67 max. length total 49.03 3.37 9.48 0.000 *** male 51.72 1.44 female 46.00 2.06 mand. length total 68.12 2.85 3.52 0.001 *** male 69.51 2.76 female 66.55 2.06 ramus length total 46.19 3.29 6.94 0.000 *** male 48.55 1.77 female 43.52 2.44 s-n length total 67.83 2.43 5.04 0.000 *** male 69.33 2.04 female 66.15 1.58 tafh total 119.04 7.40 10.20 0.000 *** male 125.06 4.39 female 112.28 2.55 uafh total 50.79 2.31 6.06 0.000 *** male 52.36 1.72 female 49.03 1.46 lafh total 68.47 4.15 5.41 0.000 *** male 71.13 3.18 female 65.47 2.88 tpfh total 77.27 5.87 13.83 0.000 *** male 82.32 2.33 female 71.59 2.17 upfh total 46.98 2.51 2.60 0.014 * male 47.95 2.13 female 45.88 2.51 lpfh total 46.63 3.01 6.92 0.000 *** male 48.80 1.67 female 44.20 2.20 frontal sinus area total 108.75 18.99 48.09 0.000 *** male 126.27 2.42 female 89.05 2.04 j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry160 table 2: the means and standard deviation of nasal breather variables gender descriptive statistics gender difference d.f.=28 mean s.d. t-test p-value ga total 124.00 1.84 0 1 (ns) male 124.00 2.00 female 124.00 1.73 sna total 83.55 2.69 3.69 0.001 *** male 85.00 2.50 female 82.00 1.96 snb total 79.03 2.24 6.02 0.000 *** male 80.63 1.71 female 77.33 1.29 max. length total 51.31 4.08 6.82 0.000 *** male 54.36 3.25 female 48.06 1.55 mand. length total 66.25 2.86 6.43 0.000 *** male 68.34 2.26 female 64.03 1.32 ramus length total 44.72 4.01 11.09 0.000 *** male 48.16 2.13 female 41.05 1.32 s-n length total 65.34 2.64 6.55 0.000 *** male 67.28 1.78 female 63.26 1.62 tafh total 110.33 6.56 24.19 0.000 *** male 116.43 1.53 female 103.82 1.36 uafh total 49.50 2.53 6.06 0.000 *** male 51.31 1.84 female 47.58 1.56 lafh total 64.52 3.52 12.93 0.000 *** male 67.62 1.01 female 61.22 1.68 tpfh total 74.05 5.29 18.91 0.000 *** male 78.90 1.56 female 68.88 1.38 upfh total 44.78 2.90 8.14 0.000 *** male 47.08 1.79 female 42.32 1.43 lpfh total 42.91 3.41 9.94 0.000 *** male 45.77 1.88 female 39.87 1.37 frontal sinus area total 186.32 41.81 66.28 0.000 *** male 226.01 3.67 female 143.99 3.19 j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry161 table 3: comparison between nasal breather and mouth breather variables gender descriptive statistics group difference nasal breather mouth breather mean s.d. mean s.d. t-test p-value ga total 124.00 1.84 126.94 3.02 -4.68 0.000 *** male 124.00 2.00 126.78 3.78 -2.63 0.013 * female 124.00 1.73 127.13 1.96 -4.69 0.000 *** sna total 83.55 2.69 82.47 2.19 1.78 0.081 (ns) male 85.00 2.50 82.72 2.05 2.91 0.006 ** female 82.00 1.96 82.19 2.37 -0.24 0.813 (ns) snb total 79.03 2.24 78.82 1.78 0.42 0.678 (ns) male 80.63 1.71 79.06 1.89 2.53 0.017 * female 77.33 1.29 78.56 1.67 -2.28 0.030 * max. length total 51.31 4.08 49.03 3.37 2.47 0.016 * male 54.36 3.25 51.72 1.44 3.13 0.004 ** female 48.06 1.55 46.00 2.06 -4.03 0.000 *** mand. length total 66.25 2.86 68.12 2.85 -2.63 0.011 * male 68.34 2.26 69.51 2.76 -1.35 0.188 (ns) female 64.03 1.32 66.55 2.06 3.13 0.004 ** ramus length total 44.72 4.01 46.19 3.29 -1.62 0.111 (ns) male 48.16 2.13 48.55 1.77 -0.59 0.556 (ns) female 41.05 1.32 43.52 2.44 -3.48 0.002 ** s-n length total 65.34 2.64 67.83 2.43 -3.97 0.000 *** male 67.28 1.78 69.33 2.04 -3.10 0.004 ** female 63.26 1.62 66.15 1.58 -5.01 0.000 *** tafh total 110.33 6.56 119.04 7.40 -5.00 0.000 *** male 116.43 1.53 125.06 4.39 -7.46 0.000 *** female 103.82 1.36 112.28 2.55 -11.40 0.000 *** uafh total 49.50 2.53 50.79 2.31 -2.15 0.036 * male 51.31 1.84 52.36 1.72 -1.73 0.094 (ns) female 47.58 1.56 49.03 1.46 -2.67 0.012 * lafh total 64.52 3.52 68.47 4.15 -4.11 0.000 *** male 67.62 1.01 71.13 3.18 -4.23 0.000 *** female 61.22 1.68 65.47 2.88 -4.97 0.000 *** tpfh total 74.05 5.29 77.27 5.87 -2.31 0.024 * male 78.90 1.56 82.32 2.33 -4.96 0.000 *** female 68.88 1.38 71.59 2.17 -4.12 0.000 *** upfh total 44.78 2.90 46.98 2.51 -3.28 0.002 ** male 47.08 1.79 47.95 2.13 -1.28 0.208 (ns) female 42.32 1.43 45.88 2.51 -4.82 0.000 *** lpfh total 42.91 3.41 46.63 3.01 -4.67 0.000 *** male 45.77 1.88 48.80 1.67 -4.98 0.000 *** female 39.87 1.37 44.20 2.20 -6.52 0.000 *** frontal sinus area total 186.32 41.81 108.75 18.99 9.78 0.000 *** male 226.01 3.67 126.27 2.42 94.60 0.000 *** female 143.99 3.19 89.05 2.04 57.50 0.000 *** degree of freedom total: 58 males: 28 females: 28 j bagh college dentistry vol. 25(2), june 2013 the frontal sinus dimensions orthodontics, pedodontics and preventive dentistry162 table 4: correlation between frontal sinus area and other variables in both groups variables frontal sinus area nasal breather mouth breather ga r 0.023 -0.041 p 0.900 (ns) 0.818 (ns) sna r 0.588 0.102 p 0.000 *** 0.567 (ns) snb r 0.761 0.119 p 0.000 *** 0.503 (ns) max. length r 0.799 0.857 p 0.000 *** 0.000 *** mand. length r 0.758 0.492 p 0.000 *** 0.003 ** ramus length r 0.894 0.773 p 0.000 *** 0.000 *** s-n length r 0.769 0.681 p 0.000 *** 0.000 *** tafh r 0.969 0.860 p 0.000 *** 0.000 *** uafh r 0.733 0.727 p 0.000 *** 0.000 *** lafh r 0.922 0.666 p 0.000 *** 0.000 *** tpfh r 0.954 0.909 p 0.000 *** 0.000 *** upfh r 0.826 0.402 p 0.000 *** 0.018 * lpfh r 0.865 0.749 p 0.000 *** 0.000 *** references 1. rakosi t. an atlas and manual of cephalometric radiography. 2nd ed. london: wolfe medical publications ltd; 1982. 2. harris am, wood re, nortje cj, thomas cj. gender and ethnic differences of the radiographic image of the frontal region. j forensic odontostomatol 1987; 5:517. 3. rossouw 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(ivsl) 28. riedel ra. the relation of maxillary structures to cranium in malocclusion and in normal occlusion. angle orthod 1952; 22(3) 142-5. (ivsl) 29. steiner cc. cephalometrics for you and me. am j orthod 1953; 39(10): 729-55. 30. sinclair pm, little rm. dentofacial maturation of untreated normals. am j orthod 1985; 88(2): 146-56. 31. jones ml, oliver rg. w & h orthondontic notes. 6th ed. oxford: wright; 2000. p. 28. 32. waston rm, warren dw, fischer nd. nasal resistance, skeletal classification and mouth breathing in orthodontic patients am j orthod 1968; 54: 367-79. 33. ruf s, psncherz h. frontal sinus developmentnas an indicator for somatic maturity at puberty? am j orthod dentofacial orthop 1996; 110(5): 476-82. 34. björk a. cranial base development. am j orthod 1955; 41: 198-255. 35. baer mj, harris je. a commentary on the growth of the human brain and skull. am j physical anthropol 1969; 30:39-44. 36. harvold ed, tomer, bs, vargervik k, chierici, g. primale experiments on oral respiration am j orthod 1981; 79: 359-72. 37. cheng m.c, enlow dh, papsidero, m, broudbent, bh, oyen o, sabat m. developmental effect of impaired breathing in the face of growing child. am j orthod 1988; 58 (4): 309-320. 38. subtelny jd. oral respiration: facial mal-development and corrective dentofacial orthopedics. angle orthod 1980; 50: 147-164. (ivsl) 39. bresolin d, shapiro pa, shapiro gg, chapko mk, dassel s. mouth breathing in allergic children: it relationship to dentofacial development. am j orthod 1983; 83: 334-9. 40. santos-pinto. a alteracões nasofaringeanas craniofaciaisem pacientes com adenoid ehipertroficd: estudo cefalometrico (master’s thesis). rio de janeiro: faculdade de odontologia, universidade federal do rio de janeiro; 1984. 72 p. 41. rickets rm. forum on the tonsil and adenoid problem in orthodontics: respiratory obstruction syndrome. am j orthod 1968; 54; 485-514. 42. subtelny jd, subtelny, j.d. oral habits studies in form, function and therapy. angle orthod 1973; 43: 347-383. (ivsl) 43. gurley hw, vig ps. a technique for the simultaneous measurement of nasal and oral respiration. am j orthod 1922; 22(1): 33-41. 44. linder-aronson s, woodside dg, hellsing e. normalization of incisor position after adenoidectomy. am j orthod 1993; 103: 412-27. 45. solow b, sierbaek-nielsen s, greve g. airway adequacy, head posture and craniofacial morphology. am j orthod 1984; 86: 214-223. 46. prashar a, sharma v p, singh gk, singh gp, sharma n, singh h. a cephalometric study of frontal sinus and its relation with craniofacial patterns. indian j dental sci 2012; 5(4): 4-8. figure 1: cephalometric landmarks figure 2: cephalometric measurements j bagh college dentistry vol. 29(1), march 2017 the value of ultrasonography oral diagnosis 76 the value of ultrasonography in the diagnosis and evaluation of early therapeutic response of cervical tuberculous lymphadenitis sarab m. zeki radhi, b.d.s.(1) lamia h. al-nakib b.d.s., m.sc.(2) khairallah muzhir gabash, m.b.ch.b., f.r.c.s. (3) abstract background: tuberculosis is a worldwide infectious disease in spite of advancement in health care system. tuberculous lymphadenitis is the most prevalent form of extra pulmonary tuberculosis with predilection of cervical lymph nodes. objectives: to evaluate the reliability of grey scale ultrasonography together with color doppler in the diagnosis of cervical tuberculous lymph adenitis and evaluation of early therapeutic response. subjects and methods:from july 2015 to may 2016 in al-karama teaching hospital /kut citywasit-iraq, 25 patients (14 males and 11 females) with ages range from (6-50) years. ultrasonography examination was done for all patients and grey scale criteria (distribution, size, shape, echogenicity, echogenic hilum, intranodal necrosis and ancillary features) and vascular distribution were recorded to help in tuberculous lymphadenitis diagnosis. excisional biopsy was done to confirm the diagnosis histopathologically. after chemotherapy the patients were followed up after 46 days of treatment, again the grey scale criteria were recorded and compared with the 1st reading. results: ultrasonography could identify 88% of the patients (22/25) as having cervical tuberculous lymphadenitis while histopathology proved that only 80% of patients really have the disease. this mean that ultrasonography had good sensitivity (100%), specificity (60%) and accuracy (90%) with no false negative and 8% false positive.in following up the patients, grey scale ultrasonography criteria showed a significant difference for the same patients before and after 46 days of treatment. conclusions: ultrasonography was found to play a paramount role in detection, localization and delineation of cervical tuberculous lymph nodes hence grey scale and color doppler are reliable in diagnosis of the disease and the evaluation of therapeutic response of the patients. keywords: diagnosis, lymph node, neck, sonography, tuberculosis.. (j bagh coll dentistry 2017; 29(1):76-82). introduction tuberculosis is a worldwide infectious disease and constitute second killer infectious disease after hiv despite advanced modalities for diagnosis and treatment. (1) many organs can be affected by extra pulmonary tuberculosis but lymph nodes are the commonest site and the most affected nodes are the cervical lymph nodes.(2) inmost instances the tubercular bacilli gains entrance through the tonsil of the corresponding side of the lymphadenopathy. both bovine and human tuberculosis may be responsible. . (3) granuloma formation and caseation necrosis are important histopathological features to diagnosetuberculosis. (4) the difficulty of examining cervical lymph nodes clinically is due to their multiple number and different location. here ultrasonography appears to be better than clinical examination in sensitivity for detection of cervical lymph nodes (96.8%) (73.3) respectively. (1 )msc student, department of oral and maxillofacial radiology, college of dentistry, university of baghdad. (2) prof., department of oral diagnosis, college of dentistry, university of baghdad, bds, msc, oral radiology. (3) assist. prof., department of surgery, college of medicine, university of wasit. in cases of lymph nodes smaller than 0.5 cm the sensitivity of ultrasonography is superior than that of ct and mri. due to these facts and the availability of high frequency probes, ultrasonographybecome important in maxillofacial diagnosis. (5) grey scale sonographic merits took into account for analysis of cervical lymphadenopathy were as follows:(i)size of the lymph node: depend on the assessment of the short diameter;(ii)shape of the lymph node: depends on the ratio of short axis to long axis (s/l);(iii)nodal borders: classified as sharp or smooth;(iv)internal echogenicity: classified as hypoor hyperechoic;(v)echogenic hilum;(vi)nodal necrosis were assessed and recorded whether present or absent (5) . in1970scolor doppler ultrasonography has been used in the assessment of lymph node enlargement. it can evaluate the vascular pattern and displacement of vascularity. (6) follow up of treatment emphasize for eradication systemic disease and its local discomfort.(7) for the purpose of monitoring of the disease and evaluation of the treatment, ultrasonography is a beneficial imaging modality in the estimation of cervical lymph nodes because of itshighresolution. (8).the current study was done to file:///g:/diagnosis%20of%20tuberculous.docx file:///g:/classification.docx file:///g:/differentiate%20tuberculous%20cervical%20lymphadenopathy%20from%20nasopharyngeal%20carcinoma.docx file:///g:/us%20of%20ctl.docx j bagh college dentistry vol. 29(1), march 2017 the value of ultrasonography oral diagnosis 77 analyzethe effectivenessof sonography in the diagnosis of cervical tuberculous lymphadenitis. subjects and method this study was carried out from july 2015 to may 2016 on(25) patients, (11) females and (14) males, their ages range from(6-50) years with a mean age of (31.04) years, these patients had suspected cervical tuberculous lymphadenitis (ctla) all patients participated in this study were well informed about it, asked to co-operate, and get their approval before including them. exclusion criteria were: 1. any patients have primary malignancy in the head and neck region 2.any patient has single involved ln were excluded from the study because of follow up negation. 3.the patients that do not cooperate and come back for follow up. the 1st assessment depended on history and physical examination and further assessment need laboratory and radiological examination, ultrasonography was done using (7.5 mhz) linear array transducer the examination was done when the patients in supine position with hyperextended neck . the scanning was done followinghajek et al classification (1986) of the cervical lymph nodesstarted from region 1 in transvers plane then asking the patient to turn the head to the opposite side, starting with region 2 and ending with region 8, following the sequence of (submandibular→ parotid→ upper cervical →middle cervical→ lower cervical →supraclavicular →posterior). (9) grey scale evaluates the nodal distribution, shape, size, internal architecture and ancillary features. doppler sonography provide information about the vasculature of the lymph nodes. the key us features of ctla include hypoechogenecity, roundness, unsharp border, destructed hilum , nodal matting, adjacent soft tissue changes, strong internal echoesand displaced hilar vascularity(10). although these sonographis features are typical for ctla, none are pathognomonic so three or more criteria should be taken into account to tell that the patient has ctla.(10,11) after recording these sonographic parameters probable diagnosis was gain and when combined with clinical diagnosis we can reach to primary diagnosis. to confirm this diagnosis the patients were referred to general surgery clinic and prepared for fnac and lymph node excisional biopsy which is submitted for histopathological examination and a final diagnosis was reached. the patients were diagnosed to have ctla would have anti tuberculosis medication for 6 months. evaluation of early therapeutic responseby ultrasonography was started46 days after the 1st dose of treatment. in this visit grey scale ultrasonography was taken and the previous parameters were recorded and compared with the previous visit readings so the treatment can be evaluated. statistical analysis was done using spss version 19 computer software (statistical package for social science).then the sonographic diagnosis statistically analyzedon the basis of the final lymph node diagnoses to calculate sensitivity, specificity, positive predictive value ppv, negative predictive value npv and accuracy of sonography in the diagnosis of ctla. to evaluate efficacy of ultrasonography in assessing anti tuberculous treatmentafter short term(46 days) chi square and p-value was calculated for each sonographic feature. p value less than the 0.05 level of significance was considered statistically significant. results all the 25 patients (14 males, 11 females); their age range (6-50) years ; had cervical swelling but with different durations. all of them had fever , pain, loss of appetite and generalized weakness, however, 22 subjects represent 88% showed firm neck swelling on clinical examination and 3 with fluctuant swelling. unilateral swelling present in 8 patients (32%) while bilateral swelling was in 17 patients represent 68%. fifteen patients represent 60% come with swelling duration of three months or less while the other 10 subjects come with swelling of more than 3 months duration. out of the 25 patients with cervical lap in the current study, only 20 patients (80%) provedto have ctla by histopathological examination. age distribution of the 20 patients was higher in the 40s oflife with mean age (30.15) (sd=±15.57). eleven of them were males representing 55% and the other 9 subjects were females representing 45% with male to female ratio of (1.2:1). (fig.1) ≤ 10 2 10% 11-20 6 30% 21-30 3 15% 31-40 1 5% 41-50 8 40% age distribution of ctla patients ≤ 10 11-20 21-30 31-40 41-50 figure 1: pie chart showing the age distribution of patients with ctla j bagh college dentistry vol. 29(1), march 2017 the value of ultrasonography oral diagnosis 78 all the 25 subjects examined by ultrasoundand according to sonographiccriteriaonly 3 subjects were negative i.e. they don’t have ctla and 88% of the patients hadthe disease. (table .1) table 1: number of ctla patients diagnosed by us ultrasound n % negative 3 12 positive 22 88 total 25 100 all the patients showed an enlargement of the involved ln both in short and longaxis. the enlarged ln can be detected and measuredby us to reveal that the average long axis was 25.7mm (maximum47mm and minimum 13.4) and the average short axis was 14.4mm ( max 24.4mm and min 6.5mm), but the size alone cannot give accurate diagnosis (not specific feature). the validity of each grey scale sonographic criteria (shape, echogenicity, borders, hilum, matting, intra-nodal necrosis, peri-nodal edema and posterior enhancement) in diagnosis of ctla is expressed in terms of sensitivity, specificity, ppv, npv and accuracy indices. comparison of these indices was done to report that echogenicity had higher sensitivity, destructed hilum had higher specificity ppv and npv and posterior enhancement had higher accuracy. (table 2) table 2: comparison of the indices for each grey scale sonographic criteria grey scale characteristics sensitivity specificity ppv npv accuracy shape 60% 40% 80% 20% 56% echogenicity 100% 0% 80% 0% 80% border 65% 80% 92% 36.36% 68% hilum 60% 100% 100% 62.5% 68% matting 65% 80% 92.85% 36.36% 68% intranodal necrosis 65% 60% 86.67% 30% 64% perinodal edema 70% 60% 87.5% 33.3% 68% posterior enhancement 85% 80% 94% 57% 84% incolor doppler sonography all the patients showed hilar vascularityhowever they were displaced in 50% ofsubjects, except two patients where one of them hadavascular ln and the other hadmixed (hilar and peripheral) vascularity. figure 2: a 6 years old patient has enlarged lymph nodes of right posterior triangle figure 3: ultrasonography of right submandibular lymph node that is enlarged and round (s/l ratio=0.57) with lost hilum and posterior enhancement overall validity of ultrasonography compared with histopathology: when patients had three or more positive ultrasonographic criteria he/she was considered tb+ . as a result 22 subjects were positive in us while 20 patients really have the disease i.e. only 2 subjects were false positive representing 8%.and there is no false negative.(table 3). however ultrasonography had moderate specificity 60% it had high sensitivity, ppv, npv j bagh college dentistry vol. 29(1), march 2017 the value of ultrasonography oral diagnosis 79 and accuracy 100%, 90.9%, 100% and 92% respectively. table 3: positive and negative sonographic results in tuberculous and non-tuberculous patients us tb+ tbtotal test + 20 2 22 test 0 3 3 total 20 5 25 sensitivity=100%,specificity = 60%,ppv = 90.9%,npv= 100%,accuracy = 92%,false positive = 8%andfalse negative = 0 histopathological results histopathology has the highest sensitivity and may produce a more rapid and favorable symptomatic response and has been recommended in cases involving multiple nodes(7).twenty five (25) subjects underwent histopathological examination of their enlarged cervical lnout of them 20 subjects were consistent with tb lymphadenitisrepresenting 80% while the remaining: three of them were consistent with reactionary la (due to viral infection) (12%)and the other 2 (8%) consistent with pyogenic la.histologic features: there are two specific pathologic criteria for identifying tuberculous lymphadenitis, caseation and granuloma formation. caseation has been found to be more specific and sensitive. granuloma with caseationnecrosis had higher rate of positivity 47% compared to noncaseating necrosis.(12) caseation necrosis recorded in 95% of the patientsin this study and the only patients that did not show caseation necrosis had positive zn stain for acid fast bacilli (afb). figure 4: histopathology of ctla of a 45 years old patient, pathological findings a. multiple epithelial granulomas (black arrows). b. giant langhan's cell (white arrow). the patients were diagnosed to have ctla will be send for the specialized respiratory center of wasit directorateto be treated by taking anti tuberculosis drugs for six months. evaluation of therapeutic response: evaluation of early therapeutic responseby ultrasonography was started46 days after the 1st dose of treatment. in this visit grey scale ultrasonography was taken and the previous parameters were recorded and compared with the previous visit readings so the treatment can be evaluated figure 5:grey scale ultrasonography of rightposterior tla after 45 days of anti tb treatment show decreasing in the size of the lymph nodes and preserving fatty hilum.(1st reading s=12.7mm& 2nd reading s= 5.6mm) the mean short axis was (15.34mm) but after treatment it became (10.1mm) and 65% of cases showed ln less than 10mm in short axis. also the shape changed obviously from round to oval in 7 patients, the destructed hilum returned to appear however they were thin in 10 patients, matted ln which were appeared in 13 patients still present in only 6 patients, ultrasonography of 13 patients showed necrosis while after treatment only 6 patients showed necrosis, posterior enhancement appeared in 17 patients but after treatment it appeared in only 3 patients, finally perinodal soft tissue edema disappear in 12 patients. (table 4) a b j bagh college dentistry vol. 29(1), march 2017 the value of ultrasonography oral diagnosis 80 table 4:comparisonin grey scale criteria before and after treatment and percent of progression. criteria pretreatment percentage posttreatment percentage percent of progression long axis max 47mm 32mm min 13,4mm 10.1mm mean 25.7mm 19.8mm short axis max 24.4mm 16.7mm min 6.5mm 5.4mm mean 14.4mm 10.1mm 65% shape oval 8 40% 15 75% round 12 60% 5 25% 58.3% hilum present 8 40% 18 90% absent 12 60% 2 10% 83.3% matting present 13 65% 6 30% 53.8% absent 7 35% 14 70% necrosis present 13 65% 6 30% 58.8% absent 7 35% 14 70% posterior enhancement present 17 85% 3 15% 82.3% absent 3 15% 17 85% soft tissue edema present 14 70% 2 10% 85.7% absent 6 30% 18 90% . in ultrasonography, grey scale criteria showed a significant difference for the same patients before and after the treatment. in comparison of short axis of the involved lns before and after treatment by using t-test = 3.09 andρ-value= 0.00185 i.e. it is significant for ρ<0.05 for the shape x2=5.02 & ρ-value= 0.05,for echogenic hilum x2=10.989 & ρ=0.0009, for matting x2= 4.912 & ρ= 0.0267,for intranodal necrosis x2= 4.912 & ρ= 0.0267, for posterior enhancement x2=19.6 & ρ= 0.0001and for adjacent soft tissue edema x2=15 & ρ=0.0001, all these values are significant ( ρ< 0.05) discussion tuberculous lymphadenitiswas a common cause of cervical lymphadenopathy in the young adult below 45 year, in a study held in nigeria, where the age range of patients were (2-38) years (13).while the peak age of the ctla in the united statesis the thirties and forties (7). both the range and frequency of the patients age in the present study is consistence with these results where the range was (6-50 years) with 40% of cases were in the forties and 30% in the 2nd decade of life. tla has more frequency in females with a male to female ratio of (1:1.4) whereas pulmonary tb is more frequent in males (7). the male to female ratio in this study was 1.2:1 i.e. the disease is more in males which is different from other studies , this is may be due tosocial and sample size differences. if matching between age and gender was done, ctla appeared to be more frequentin male children and young adult females (11). in the present study 100% of patients below 20 years were males whereas 69% of the patients above 20 were females. park and kim(2012)agreed with fontanilla (2011)results, in their study 97.5% of patients complaining of swelling and it is tender in 5% of j bagh college dentistry vol. 29(1), march 2017 the value of ultrasonography oral diagnosis 81 patients , other signs and symptomslike fever weight loss recorded with low frequency, the swellings were bilateral in 12.5.(7) (11) in the present study the presentation was early due to typical response of immunological system for the invading organism that inforce most of the patients to seek medical advice , in addition to thatin our study there were no hiv positive patient. almostalways chest x-ray is recommended if tuberculosis is suspected to rule out pulmonary involvement. from analysis of multiple studies in endemic and non-endemic areas fontanilla et al(2011) declared that lung involvement recorded in 18-42% of patients with ctla, patients have hiv show higher percent of pulmonary tuberculosis than non hiv patients. (7 ) in the current study chest x-ray show no pulmonary involvement in all patients. ctla are more conspicuous than pulmonary tuberculosis but its diagnosis is difficult since it resemble other types of lap so it has been named as “dangerous masquerader”.(10) ultrasonographyappearedas a first line diagnosing imaging modality.grey scaleis used to detect ln and evaluate its characteristic(13)and color doppler assess the vascularity and its displacement.(14). from the analysis of all the previously mentionedcriteria we noticed that there is nofeature solely exhibitboth high sensitivity in diagnosis of ctla. if three or more criteria is taken into account this will increase both sensitivity and specificity and as a result accuracy of us in the diagnosis of ctla. therefore we could reachto sensitivity=100%, specificity = 60%, ppv = 90.9%,npv= 100% and accuracy = 92% in sonographic diagnosis of clinically suspectedctla patients which are comparable with park & kim ( 2014) who had a sensitivity,specificity, ppv, npv and accuracy of95.0%, 79.5%, 82.6%, 93.9%, and 87.3%, respectively in the group of patients that have (2 or more ) category.. in the present study we had no false negative and only 2 false positive but unfortunately because the sample is not big enough thespecificity is decreased to 60% otherwise our results are accepted and reliable. the false positive cases are ofchronic bilateral pyogenic infection, the long period of this infection (2 months) make their sonographic featuresmimic that of ctla. despite that most of the detected features were typically of ctla, no feature known to be pathognomonicfor tla . even though features of internal structure of ln were of greater value in diagnosis than size and shape of ln. ancillary features like matting and perinodal edema if presentedin patient without a history of radiotherapy in the neck are highly suggestive of ctla. sonography alone cannot diagnose ctla because of the interference between the sonographic criteria of ctla and metastatic ln on one hand and between ctla and reactive and nonspecific bacterial infection on the other hand , therefore other diagnosing modality is needed like histopathology, mycobacterial culture and polymerase chain reaction pcr (11). in the present study we choose histopathology as a definite diagnosing tool. after excisional biopsy and histopathological examination 80% of the cases confirmed to be ctla. park & kim(2014) from korea studied 79 patients retrospectively,40 patients (50.6%) proved to have ctla either by histopathological, microbiological and pcr terms. (11) when someone talking about the progress of situations and treatment evaluation, choosing a save, easy, cheap and repeatable imaging modality is mandatory.(8) in addition this modality should be sensitive in detecting minor changes. therefore sonography is of great importance in follow up patients with ctla. in the present study the progression was different for each grey scale criteria and ranging from (53%-85%) of cases after 1.5 months of anti tb treatment.(table 4 ) the least progression is that of matting and the best is that of perinodal tissue edema after 46 days of treatment. references 1. sandhu, g. k. (2011). tuberculosis: current situation, challenges and overview of its control programs in india. journal of global infectious diseases, 3(2), 143– 150. http://doi.org/10.4103/0974-777x.81691 2. jhab . c., dass a.,nagarkar, guptar., singhals.(2001)cervical tuberculous lymphadenopathy: changing clinical pattern and concepts in management. postgrad med j;77:185-187. 3. lugton i (1999) mucosa-associated lymphoid tissues as sites for uptake, carriage and excretion of tubercle bacilli and other pathogenic mycobacteria.immunology and cell biology,77:364–372. 4. gupta k.b., kumar a, sen r, sen j and verma m (2007) role of ultrasonography and computed tomography in complicated cases of tuberculous cervical lymphadenitis. indian j. tuberc;54:71-78. 5. chintamaneni r., sudhakara m., ravikiran a., sathish s. and sujana b. (2014) evaluation of reliability of ultrasonographic parameters in differentiating benign and metastatic cervical group of lymph nodes. isrn otolaryngol, v2014; 2014: 238740. http://dx.doi.org/10.1155/2014/238740 6. ahuja a., ying m., yuen yh., metreweli c. (2001a) power doppler sonography to differentiate tuberculous cervical lymphadenopathy from nasopharyngeal carcinoma. ajnr am j neuroradiol april; 22:735–740 http://doi.org/10.4103/0974-777x.81691 http://pmj.bmj.com/search?author1=b+c+jha&sortspec=date&submit=submit http://pmj.bmj.com/search?author1=a+dass&sortspec=date&submit=submit http://pmj.bmj.com/search?author1=n+m+nagarkar&sortspec=date&submit=submit http://pmj.bmj.com/search?author1=r+gupta&sortspec=date&submit=submit http://pmj.bmj.com/search?author1=s+singhal&sortspec=date&submit=submit http://dx.doi.org/10.1155/2014/238740 j bagh college dentistry vol. 29(1), march 2017 the value of ultrasonography oral diagnosis 82 7. fontanilla j, barnes a, and reyn f (2011) current diagnosis and management of peripheral tuberculous lymphadenitis. clin infect dis.sep;53(6):555-62. http://dx.doi.org/10.1093/cid/cir454 8. reshma vj., a, s. a., mufeed, a., vadivazhagan, &issac, j. k. (2014). characterization of cervicofaciallymphnodes a clinical and ultrasonographic study. journal of clinical and diagnostic research : jcdr, 8(8), zc25–zc28. http://doi.org/10.7860/jcdr/2014/9328.4737 9. ahuja a., ying m., king a..( 2001b) a review of ultrasound of cervical lymph nodes. bmus bulletin 9 (3): 6-10. 10. chou c., yang t., wang c.(2014) ultrasonographic features of tuberculous cervical lymphadenitis.journal of medical ultrasound, 22(3): 158–163. http://dx.doi.org/10.1016/j.jmu.2014.06.007 11. park j and kim d (2014) sonographic diagnosis of tuberculous lymphadenitis in the neck. jum, september; 33 (9):16191626.http://doi.org/10.7863/ultra.33.9.1619 12. gupta p.r.(2004). difficulties in managing lymph node tuberculosis. lung india 2004;21:50-3 13. olu-eddo, a. n., &omoti, c. e. (2011). diagnostic evaluation of primary cervical adenopathies in a developing country. the pan african medical journal, 10, 52. 14. mohseni, s., shojaiefard, a., khorgami, z., alinejad, s., ghorbani, a., &ghafouri, a. (2014). peripheral lymphadenopathy: approach and diagnostic tools. iranian journal of medical sciences, 39(2 suppl),158– 170. الخالصة هي العنقية اللمفاوية الغدد وبالخصوص الغدداللمفاوية .الهائل الصحي التقدم من الرغم على العالم في الشائعة االنتقالية االمراض من التدرن مرض اليزال:الخلفية شعاعيا المختلفة الفحوص بواسطة اثباته ثم لمرضا لتوقع األولى هوالخطوة السريري الطبي الحدس .الرئتين خارج التدرني لاللتهاب تعرضا األكثر الجزء .المرض لتشخيص األكثرحساسية والدوبلرهوالواسطة يعتبرالسونارالعادي .ونسيجيا . العالج تحت التدرني اللمفاوية العقد التهاب مرضى من عينة ومتابعة تشخيص والدوبلرفي السونارالعادي مكفاءة هوتقيي الدراسة من الغرض :الدراسة من الهدف اللمفاوية الغدد تضخم من يعانون سنة ( 50-6) أعمارهم تتراوح (اناث 11 ذكوراو 14) مريضا 25 , 2016 أيار وحتى 2015 تموز منذ :والطريقة األشخاص إعطاءالعالج تم . المتضخمة يةاللمفاو الغدد من اخذت التي للعينات النسيجي الفحص اجري كما , السونار بواسطة الفحص ثم السريري للفحص خضعوا العنقية .الذين المرضى الولئك للتدرن الالزم التشخيص في اخذت التي بتلك الفحص نتائج لنقارن العالج بدء من يوما 46 السوناربعد بواسطة والمتابعة الدوري للفحص واخضعوا لديهم التدرن تشخيص ثبت .االولي %80 ان النسيجي الفحص اثبت بينما ,التدرني العنقية الغدداللمفاوية انهاالتهاب السونارعلى بواسطة شخصت قد ( 22/25) المرضى من %88 نسبة كانت :النتائج وفي . كاذب إيجابي معدل %8 و كاذبة سلبية وبدون %90 ودقة %60 وخصوصية %100 جيدة السونارذوحساسية ان وهذايعني .فعال مصابين ( 20/25) منهم .العالج يومامن 46 وبعد قبل المرضى لنفس معتدبه ناكفرق انه وجد السونار ئصخصا بواسطة المرضى متابعة العالج تحت هم الذين المرضى متابعة في وكذا التدرني العنقية اللمفاوية الغدد وتشخيص اكتشاف دوراهامافي يلعب السونار ان وجد :االستنتاج http://dx.doi.org/10.1093/cid/cir454 http://doi.org/10.7860/jcdr/2014/9328.4737 http://dx.doi.org/10.1016/j.jmu.2014.06.007 http://doi.org/10.7863/ultra.33.9.1619 10fawaz f.docx j bagh college dentistry vol. 28(3), september 2016 salivary immunoglobulin oral diagnosis 65 salivary immunoglobulin a assessment in lymphoma patients before and after chemotherapy mohammed h. abdulshaheed, b.d.s., h.d.d. (1) fawaz d. al-aswad, b.d.s., m.sc., ph.d. (2) haider n. salh, m.b.ch.b, d.m.r.t. (3) abstract background: lymphomas are group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and caused the characteristics lymphadenopathy. occasionally, they may spill over into blood or infiltrate organs outside the lymphoid tissue. the major subdivision of lymphomas is into hodgkin lymphoma and non–hodgkin lymphoma and this is based on the histologic presence of reed-sternberg cells in hodgkin lymphoma. salivary immunoglobulin a is the prominent immunoglobulin and is considered to be the main specific defense mechanism in oral cavity. the aim of this study was to determine the level of salivary immunoglobulin a in lymphoma patients before and after chemotherapy treatment. subjects, materials and methods: the study included 25 patients (15 male and 10 female) with non–hodgkin lymphoma(b-cell type) , 25 patients( 16 male and 9 female ) with hodgkin lymphoma and 25 (15 male and 10 female) healthy control group. whole un-stimulated saliva was collected to determine the level of salivary immunoglobulin a, which measured by enzyme link immunosorbent assay. results: the level of salivary immunoglobulin a was significantly higher in pre-treatment patients in comparison with control group, and there was a significant decrease after chemotherapy treatment when compared to their base line levels in both study groups. conclusion: the salivary immunoglobulin a was higher in lymphoma patients than control, then its level showed obvious decrease after chemotherapy treatment. key words: non–hodgkin, hodgkin lymphoma, salivary immunoglobulin a. (j bagh coll dentistry 2016; 28(3):65-68). introduction lymphomas are a group of diseases caused by malignant lymphocytes that accumulate in lymph nodes and cause the characteristics clinical features of lymphadenopathy. occasionally, they may spill over into blood (leukemicphase) or infiltrate organs outside the lymphoid tissue. the major subdivision of lymphomas is into hodgkin lymphoma(hl) and non–hodgkin lymphoma (nhl)and this is based on the histologic presence of reed-sternberg (rs) cells in hodgkin lymphoma(1). non-hodgkin’s lymphomas are a heterogeneous group of lymphoproliferative disorders originating in b, t, or natural killer lymphocytes. the b-cell lymphomas represent about 80% to 85% of the cases, with 15% to 20% being t-cell lymphomas; natural killer lymphomas are rare (2). hodgkin’s lymphoma is a lymphoproliferative malignancy of b-cell origin. according to the who classification, hodgkin's lymphoma isdivided into a classical variant and a nodular lymphocyte predominant variant. classical hl is separated into four subtypes: lymphocyte rich type, nodular sclerosis type, mixed cellularity type and lymphocyte depleted type (3).immunoglobulin a (iga) is an antibody that plays a critical role in mucosal immunity(4). (1) m. sc. student, department of oral diagnosis. college of dentistry, university of baghdad. (2) professor, department of oral diagnosis. college of dentistry, university of baghdad. (3) clinical oncologist, al-sadder medical city/najaf. immunoglobulin a accounts for more than 70 percent of total immunoglobulin in the body; although its concentration in the serum is relatively low. iga is concentrated in mucosal secretions, including nasal and pulmonary secretions, saliva, tears, breast milk, and secretions of the genitourinary and intestinal tracts (5). salivary iga is the prominent immunoglobulin and is considered to be the main specific defense mechanism in oral cavity (6). it is the first line of host defense against pathogens which invade mucosal surfaces, these antibodies could help oral immunity by preventing microbial adherence, neutralizing enzymes, toxins, and viruses; or by acting in synergy with other factors such as lysozyme and lactoferrin (7). materials and methods sample a comparative study was performed in the oncology unit of al-sadder medical city in alnajaf. the study samples consist of (50) patients with lymphoma with age range (20-50) years and divided into: 1. the first group consisted of (25) patients with hodgkin lymphoma taking adriamycin, bleomycin, vinblastine and dacarbazine (abvd) chemotherapy regimen. 2. the second group consisted of (25) patients with non-hodgkin lymphoma j bagh college dentistry vol. 28(3), september 2016 salivary immunoglobulin oral diagnosis 66 (b cell type) taking rituximab (r) in combination with cychlophosphomide, hydroxodaunorubicin, vincristine (oncovine) and prednisolone (r-chop) chemotherapy regimen. exclusion criteria -diabetic patients. -pregnant women. -heavy smokers and alcoholism. -patients with severe periodontal disease. -patients under radiotherapy. -other metabolic disease and patients taking other medications suppress the immunity. the whole saliva was collected to evaluate the level of salivary immunoglobulin a, at two times interval: first before taking medical treatment (at the time of diagnosis) and second after receiving three cycles of medications (28 days for each cycle of abvd and 21 days for each cycle for r-chop). the study time was from the period (11/2013 – 5/2014).control group consist of (25) looking healthy and age, sex match with patient groups. saliva collection unstimulated saliva had been obtained by having the subject seated quietly with his or her head flexed forward and the subject gently spit into a collection container for a specified amount of time. this method of collection is considered the “gold standard” for obtaining many components of saliva (8). to avoid circadian variations, saliva samples were collected between 9 a.m. and 1.00 p.m. in order to obtain a sample of total saliva, the patients were instructed not to eat or drink (except water) for 1 hour(9). saliva samples were kept in ice during the collection. in order to reduce bubble and foam, samples were centrifuged at speed of (3000-3500 rpm) and supernatant stored at -20°c freezer until immunological analysis (10). determination of salivary iga the level of salivary iga in saliva was determined using secretory immunoglobulin a elisa kits – cloudclone corp (usa). statistical analysis statistical analyses were performed using excel program (2010) from microsoft co. results the iga mean values was variant among control group (240) μg/ml, nhl patients at the time of diagnosis (301) μg/ml and after receiving three cycles of r-chop (220) μg/ml as shown in figure (1), with significant relationship (p<0.05) between pre-treatment patients and control group and highly significant difference (p<0.001) between pre-treatment and post-treatment patients, as shown in table (1). this study also showed different levels of salivary iga among control group (240) μg/ml, hl patients at the time of diagnosis (296) μg/ml and after receiving three cycles of abvd (225) μg/ml as shown in figure (2), and there was significant increase (p<0.05) in pre-treatment patients in comparison to control group and highly significant difference (p<0.001) between pre and post-treatment patients, as shown in table (1). table 1: the mean values ± sd of salivary iga for nhl and hl patients and control group with their comparison significant variable nhl pre-treatment nhl post treatment nhl pretreatment control nhl post treatment control iga mean ±sd 301±79.5 220±56 301±79.5 240±116 220±56 240±116 p-value 0.0001 ** 0.035 * 0.44^ variable hl pre-treatment hl post treatment hl pretreatment control hl post treatment control iga mean± sd 296±75 225±48 296±75 240±116 225±48 240±116 p-value 0.0002 ** 0.047 * 0.56^ nhl= non-hodgkin lymphoma, hl= hodgkin lymphoma,*= significant, **=highly significant, ^ = non significant, sd= standard deviation. j bagh college dentistry vol. 28(3), september 2016 salivary immunoglobulin oral diagnosis 67 figure 1: the different levels of iga mean values in μg/ml for control group, nhl patients before treatment and after three cycles of r-chop. figure 2: the different levels of iga mean values in μg/ml for control group, hl patients before treatment and after three cycles of abvd discussion the present study showed a significant elevation of salivary iga level in pre treatment patients with malignant lymphoma when compared with those of the control, this finding didn’t match with ellison et al. (11) and biggar et al.(12)as they found in their studies a significant decrease in serum level of immunoglobulin including iga in lymphoma patients before starting therapy. while timucin et al.(13) reported that total serum iga concentration was found to be within normal ranges in all nhl & hl patients. this difference may be explained by first: change in oral microflora and this may lead to local increase of salivary iga secretion, this was documented by ye etal.(14)as they said the patients with malignancies exhibited a less diverse and significantly different bacterial community in their oral cavity when compared to control group, second; there does not appear to be any correlation between serum and salivary immunoglobulins. this may suggest that extravascular transfer of immunoglobulin a primarily depends on the mucosal status of the individual and not necessarily the serum level (15). the current study showed a significant decrease in the salivary iga level in lymphoma patients after chemotherapy treatment in comparison with its baseline level, this agree with the result of pekka et al.(16) and erika et al.(17)when they noticed a significant decrease in the salivary iga level during chemotherapy. the lower level of salivary iga may be a result of impairing the normal function of the human immune system by chemotherapy which can cause major alterations in the oral defense mechanisms that are likely to play a role in the decrease of salivary contents of immunoglobulins (18). references 1. hoffbrand. text book of essential hematology. 6th ed. wiley blackwell; 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20(2): 87-92. 14. ye y, carlsson g, agholme mb, wilson j, etal., oral bacterial community dynamics in pediatric patients with malignancies in relation to chemotherapy-related oral mucositis: a prospective study.clinmicrobiol infect2013; 19(12): e559–67. 15. lasisi tj, yusuf bo, lasisi oa, akang eeu. salivary and serum iga evaluation of patients with oro-facial squamous cell carcinoma. international j otolaryngol head neck surg 2013; 2: 42-5. 16. laine p, meurman jh, murtomaa jth, et al. salivary flow and composition in lymphoma patients before, during and after treatment with cytostatic drugs. eur j cancer b oral oncol 1992; 28(2): 125–8. 17. erika barbara abreu fonseca thomaz , josé carlos elias mouchrek jr. etal.longitudinal assessment of immunological and oral clinical conditions in patients undergoing anticancer treatment for leukemia.int j pediatrotorhinolaryngol 2013; 77(7): 1088–93. 18. goldsby r, kindt t, osborne b. kuby immunology. 4thed. new york: w. h. ferrman and company; 2000. ma'an final.doc j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 18 an evaluation of an iraqi phosphate-bonded investment and a commercial type on the marginal fit of ceramometalcopings using three different investing and burnout techniques ma'an rasheed zakaria, b.d.s., m.sc., ph.d. (1) dhifaf mohammad al-obaidi, b.sc., m.sc. (2) abstract background: the accuracy of fitness of any dental casting is imperative for the success of any prosthodontic treatment. from the time that dental casting was first introduced, efforts have been made to produce more accurate and better fitted castings with minimal marginal discrepancy. the aim of this in vitro study was to evaluate the effects of three different investing and burnout techniques on the vertical marginal discrepancies ofceramometalcopings invested with two types of phosphatebonded investments. materials and methods: sixty wax patterns were fabricated on a standardized prepared brass die representing an upper central incisor by the aid of a custom-made split mold. three different investing and burnout techniques were applied for an iraqi investment and a commercial type; group i:ring investing with conventional burnout technique (rc);group ii: ringless investing with conventional burnout technique (rlc);group iii: ring investing with accelerated burnout technique (ra).twenty wax patterns of each group were divided into two subgroups according to the type of investment material used (10 for each subgroup) represented as (b) for the bellastar xl and (w) for the wymvest investments. complete castings were finished and seated on the metal die. the accuracy of fit of each coping was determined by measuring the vertical marginal discrepancies between the finish line on the metal die and the margins of each coping at four specific reference points on the labial, mesial, palatal, and distal aspects of the die by the aid of a light microscope supplied with a digital camera.the arithmetic mean of each three records was computed and regarded as the amount of the marginal discrepancy of each coping and was used as a unit for the statistical analysis. results: mean marginal accuracy for w(rlc)was found to be the least (13.839+4.5724 um) while the highest mean value related to b(rlc) (29.033+2.102 um). in general, anova test showed significant results among the mean values of the binvestment subgroups while lsd test showed non-significance between the (ra) and both the (rc) and (rlc) subgroups. on the other hand, significance was present between the (rlc) and (ra)of the winvestment subgroups while non-significance was located between the (rc) and both the (rlc) and (ra) subgroups. comparing similar subgroups of the two tested investments, the student's t-test showed non-significance between the (rc) subgroups while high significance was located between the (rlc) and (ra) subgroups respectively.concerning the vertical marginal discrepancy of the copings, applying the (rc) technique for both investments caused non-statistical significance between the labial, mesial, palatal, and distal aspects.the (rlc) technique caused high significance between the four aspects, while the (ra) technique caused non-significance between the labial aspect only and the others. conclusion: the iraqi investment generally produced less vertical marginal discrepancies (using the three different investing and burn-out techniques) than the commercial investment.in order to achieve a better marginal fit, it seems that ceramometalcopings invested with the commercial investment tested are better be cast using the conventional ring investing and burnout technique. key words: phosphate-bonded investments, marginal fit, ceramometalcopings. (j bagh coll dentistry 2014; 26(3):1826). introduction the accuracy of fitness of any dental casting is imperative for the success of any prosthodontic treatment. from the time that dental castingswere first introduced, efforts have been made to produce more accurate and better fitted castings with minimal marginal discrepancies (1). fixed restoration margins must fit as precisely as possible to the prepared tooth which is essential for its longevity because it allows less plaque accumulation at the marginal area, provides better (1) professor. department of conservative dentistry, college of dentistry, university of baghdad (2)market research and consumer protection center, university of baghdad. mechanical properties (stability, resistance), less cement space (less possibility for leakage) and improves the esthetic result; therefore, the fabrication of metal castings that fit tooth preparation has been considered as one of the prime objectives of fixed prosthodontics (2). one of the critical factors associated with crown construction is the dimensional accuracy of casting. the fitness of crown is influenced by the quality of the investment material and the metal, casting conditions, metal finishing, and firing of porcelain (3,4). the production of accurate dental casting by the lost wax process involves casting molten alloy into a refractory mold which is sufficiently and precisely oversized to accommodate the shrinkage j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 19 of the alloy during cooling.expansion of dental investment plays an equally important role in the fit of dental casting, the phosphatebonded investments expand rapidly at the temperature used for casting alloys thus their size can be conveniently controlled (5). the final fit of the casting is the result of controlled distortion of the mold, which is the cumulative result of variables such as the water/ powder ratio, mixing speed, temperature of the room and liquid, type of lining material and it is also influenced by the restrictive confines of the casting ring and the variation in dimension of the mold cavity (5). it has been stated that "the slight modification of recommended investing procedures is required to produce consistently well fitting castings with base metal casting alloys" (6). the conventional investing and casting techniques have been reported to be as time consuming and that the accelerated investing and casting technique can be a vital alternative to the conventional type (7). crowns were found to be successfully cast using acceleratedmold preparation techniques in spite of littlefinesse observed (8). it has been demonstrated that it was possible to eliminate metal casting ring technique when using phosphate bonded investments to provide greater expansion of the investment mold, thus providing a more precise fit for base metal alloy castings. ringless casting technique has simplified the casting of ni-cr and pd alloys by eliminating not only the metal rings but also the use of ring liners and water bath (9). results had shown that the castings produced by the ringless investing and burn-out technique had provided significant less vertical marginal discrepancies than those produced by the conventional metal ring technique. ringless investing technique allows for more expansion of the investment mold and therefore produces castings which bind less on the die (2, 10). ringless system of casting has been recommended for use in fabricating implant supported fixed dental restorations since it produced significantly less vertical marginal discrepancy compared to the metal ring casting technique (11). in addition, since testing different phosphatebonded investments proved to cause significant effects on the vertical marginal discrepancies of metal copings cast by pd-ag and ni-cr alloys utilizing the conventional investing technique (12), and since the iraqi-made phosphate-bonded investment (wymvest) was efficiently able to cast ni-cr alloys for pfm copings (13).the necessity to evaluate the effects of such investments utilizing ringless investing and accelerated methods on the vertical marginal discrepancies of cast crowns becomes a priority. materials and methods a milling machine (bego, germany) was used to prepare the axial walls ofa brass model representing a maxillary central incisor to ensure proper degree of taper. a heavy chamfer finishing line all around the tooth of 1.1mm depth was prepared and measured with a digital vernier caliper of +0.1mm accuracy. final preparation measurements were 7mm in height, and 6-8 degrees of convergence. in order to produce standardization of the wax patterns to have a uniform thickness of 0.5mm, a brass split mold was fabricated consisting of two halves secured with two metal bolts to facilitate wax pattern removal (fig.1). figure 1: the split mold framework with the prepared brass die fixed into the mold. a total of sixty wax patterns (type ii blue inlay wax, dt&t, italy) were obtained.two phosphate-bonded investments (bella starxl, bego, germany, and wymvest, iraq) were used for investing 20 copings for each group which were divided according to the type of investing and burnout techniques used; group i: ring investing with conventional burnout technique(rc), group ii: ringless investing with conventional burnout technique(rlc), and group j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 20 iii: ring investing with accelerated burnout technique (ra). ring investing with conventional burnout technique (rc) was carried out using a metal ring (size 3x) which harvested each sprued10 wax patterns. the ring was lined with a single layer of asbestos-free liner wetted with water. the wax patterns were painted with a surface tension reducing agent (waxitspray, dentaurum, germany), and invested with each of the tested investmentsmixed at room temperature according to the manufacturer's l/p ratio with its special liquid without dilution, (table1). table 1: manufacturer's information for investment tested. after completeinvesting, the rings were left to bench set according to the burnout technique used later. ringless investing with conventional burnout technique (rlc) included a rapid ringless system which consisted of a plastic ring (size 3x) (rapid ringless system, bego, germany) instead of a metal ring. similar procedures used with the ring investing technique were adopted except that the plastic ring was removed after 15 min. of initial setting of the investment following the manufacturer's instructions, (fig.2). figure 2: the muffle of investment disassembled from the plastic ring burnout techniques consisted mainly of two procedures; a. conventional burnout technique: in which, after the final setting was completed, the ring assembly was kept in the electrical furnace (gc auto furnace, gc dental industrial corp., japan) at room temperature with the crucible side downward to facilitate evacuation of the molten wax after heating. then the ring was heated gradually to 250°c at a rate of 5°c/min., and was kept at this temperature for 60 min. for complete wax elimination. the temperature was elevated gradually to the final burnout temperature (900°c950°c) and kept for 30 min. at the last 10 min., the ring position was reversed with the crucible side positioned up to allow oxygen to contact the surface of the mold to ensure complete wax residue elimination; b. accelerated burnout technique: in which, after a bench set of 20 min. for the bella star xl investment and 15 min. for the wymvest investment, the ring was placed directly in the preheated furnace at a final temperature of (900°c-950°c), and was maintained at the final temperature for 30 min., then the ring was ready for casting procedure (7). the alloy used for casting all specimens was nicr (beryllium free) ceramometal alloy (heraenium-na, heraeuskulzer, germany). each ring was cast with 24gm of new metal by weighing it with the aid of a double pan sensitive electronic balance (sartorius, germany). the casting procedure was done using an induction casting machine (manfredi, italy) to eliminate casting variables resulting from torch casting. after casting, the rings were left to bench cool to room temperature and the castings were devested from the investment manually, rinsed and cleaned with tap water and bristle brush followed by drying with oil-free air (8).the metal copings were separated from their spruesby cutting discs mounted on a laboratory hand piece attached to a micro-motor dental laboratory machine (w&h, austria). the internal surface of each casting was visually inspected by a magnifying lens (10x) for the presence of minute internal nodules that prevented complete seating on the die, which were removed using round tungsten carbide bur mounted on a straight hand piece. the copings external surfaces were finished sequentially with stone burs to a standardized thickness of 0.5 mm verified with a metal caliper invest ment manuf. l/p ratio ml/gm working time (min.) setting time (min.) thermal expan. % total expan. % final burnout temp.&time bellastar xl bego germany 40/160 3 for conventional: at least 30 for accelerated: 20-30 1.1 2.1 900ºc 30 min. wym vest iraq 21/100 5 for conventional: 35 for accelerated: 15 1.1-1.2 1.9-2.0 950ºc 30 min. j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 21 device (aesculap, germany). all copings among each subgroup were numbered from 1 to 10 and each numbered coping was isolated in a plastic container. each major group was subdivided into 2 subgroups (10 copings each) according to the type of investment tested as follows;b (rc): invested with bellastar xl investment, w (rc): invested with wymvest investment, b(rlc):invested with bellastar xl investment, w (rlc): invested with wymvest investment, b (ra): invested with bellastar xl investment, and w (ra): invested with wymvest investment. each coping was seated on the metal die that was affixed to a clear acrylic block in order to ensure that each margin on the four aspects of the coping would be examined and measured from the same angle at each time.the measurements were made on predetermined areas that were marked on the four aspects of the metal die (labial, mesial, palatal and distal) as a dented point below the margin of the preparation, to be easily found under the microscope in order that the measurements could be made at the same point on each aspect at each time(2). a screw-loaded holding device was used during measurements to maintain the seating between the metal copings and the metal die (14) (fig.3). figure 3: close view of preparation margin of the brass die and the gingival margin of the coping the marginal adaptation of each coping was determined by measuring the vertical marginal discrepancy between its gingival margin and the margin of the die preparation at four specific reference points which was achieved by using a light microscope (nikon-eclipse me 600, japan) provided with a digital camera (nikon dxm 1200f, japan) connected with a computer. the microscope was calibrated to 0.001mm (1µm) at 100x magnification. the measurements were done by placing the sample on the micrometer stage, which was driven until the imaging picture of the marginal area was displayed clearly on the computer monitor.this imaging picture was treated with two programs; the first program (atc1) was used to measure the value in (µm) of vertical marginal discrepancy between the coping and the metal die at the predetermined mark by drawing a line between the preparation area and the margin of coping. this line gave a digital reading which was recorded. the other program (lucia) was used to record the imaging picture of the measured area. this method was carried out first on the labial aspect followed by mesial, palatal and distal aspects. measurements for each aspect were done 3 times repeatedly to ensure the accuracy and to overcome any fault in reading (15). measurements were continued for all the samples of the series of each subgroup in the same manner. the marginal discrepancy value of each coping was the arithmetic mean of those three measurements on the four surfaces. results the mean marginal gaps, standard deviation and standard errors for the subgroups of bellastar xl (b) and wymvest (w) investments are listed in table2. among the two types of investments, the highest mean marginal gap for the bellastar xl investment was scored using the (rlc)technique (29.033+2.102µm), while its lowest mean was scored by the (rc) technique (15.476+4.3926 µm). for the wymvest investment, the highest mean was scored by the (rc) technique (14.240+3.2509 um) while the lowest mean related to the (rlc) technique (13.839+4.5724 um),(table 2). j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 22 table 2: descriptive statistics of bellastar xl(b) &wymvest (w)investment groups distributed among their different subgroups. subgroup no. mean (µm) sd se b(rc) 10 15.476 + 4.3926 1.3890 b(rlc) 10 29.033 +2.1020 0.6647 b(ra) 10 19.719 +1.0701 0.3384 w(rc) 10 14.420 +3.2509 1.0280 w(rlc) 10 13.839 +4.5724 1.4459 w(ra) 10 14.224 +2.6968 0.8528 rc: ring investing with conventional burnout technique, rlc: ringless investing with conventional burnout technique, ra: ring investing with accelerated burnout technique analysis of variance (anova) test among the bellastar xl subgroups showed significant differences at p<0.05 between two subgroups (table 3) which was clarified by the lsd test showing significant difference between (rc) and (rlc) techniques. on the other hand, nonsignificant differences at p >0.05 existed between the (ra), and both (rc) and (rlc)techniques (fig. 4). table 3: anova – one way for bellastar xl investment subgroups. s.o.v ss df ms f p-value between 6.372 2 3.186 27.947 (s) p<0.05 within 0.800 7 0.114 total 7.172 9 rc rlc ra s ●------0.014------● ns●--------------0.168--------------● ns ●-----0.536-----● s: p<0.05, sig., ns: p>0.05 (non – sign.) figure 4: anova (by – lsd) for bellastarxl investment subgroups. anova test among subgroups of wymvest investment showed non-significant differences at p>0.05 between two subgroups at least, (table 4) clarified by lsd test showing non-significant differences at p> 0.05 between (rc) and both (rlc) and (ra) subgroups while significant differences existed between (rlc) and (ra) subgroups (p<0.05), (fig. 5). table 4: anova – one way for wymvest investment subgroups. s.o.v ss df ms f p-value between 0.100 2 0.050 0.125 (ns) p>0.05 within 2.800 7 0.400 total 2.900 9 rc rlc ra ns ●-----0.884------● ns●------------0.335------------● s●------0.043------● s: p<0.05 (sign.), ns: p>0.05 (non – sign.) figure 5: anova (by – lsd) for wymvest investment subgroups applying the student's t-test to compare similar groups of the two tested investments, nonsignificant differences were located between (rc) subgroups of both types while highly significant differences existed between (rlc) and (ra) subgroups as shown in table 5. j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 23 table 5: t-test of mean marginal gap between bellastar xl and mymvest investment subgroups subgroup t df p-value c.s. b(rc) –w(rc) 0.652 9 p>0.05 ns b(rlc) –w(rlc) 7.830 9 p<0.01 hs b(ra) – w(ra) 6.014 9 p<0.01 hs marginal gap mean values for the labial, mesial, palatal, and distal aspects of the tested copings using the three investing techniques for the bellastar xl and wymvest investments are presented in figs.6 and 7. figure 6: bar-chart according to the mean values of themarginal gap by (µm) for each subgroup related the bellastar xl investment for all coping aspects. figure 7: bar-chart according to the mean values of the marginal gap by (µm) for each subgroup related to the wymvest investment for all coping aspects. applying the student's t-test to verify the statistical significance between similar pairs of subgroups in the two investments tested, nonsignificant differences were present between the four aspects using the conventional ring investing technique (rc), (table 6). table 6: ttest of marginal gap for all aspects of copings in µm invested by bellastar xl (b) and wymvest (w) using (rc) technique. aspects subgroup t df c.s labial b(rc) –w(rc) 1.322 9 ns* mesial b(rc) –w(rc) 0.772 9 ns palatal b(rc) –w(rc) 0.115 9 ns distal b(rc) –w(rc) 1.797 9 ns *p> 0.05 on the other hand, the ringless conventional investing technique (rlc) caused high significant differences in the four aspects of the tested copings for both investments, (table 7). table 7: ttest of marginal gap for all aspects of copings in µm invested by bellastar xl (b) and wym vest (w) using (rlc) technique. aspects subgroup t df c.s labial b(rlc) –w(rlc) 8.894 9 hs mesial b(rlc) –w(rlc) 9.640 9 hs palatal b(rlc) –w(rlc) 4.645 9 hs distal b(rlc) –w(rlc) 7.519 9 hs ring investing with accelerated burnout technique (ra) caused non-significant differences (p> 0.05) in the labial aspects of the copings using both investments while highly significant differences (p <0.01) were scored in the mesial, palatal, and distal aspects for both investments, (table 8). table 8: ttest of marginal gap for all aspects of copings in µm invested by bellastar xl (b) and wymvest (w) using (ra) technique. aspects subgroup t df p-value c.s. abial b(ra) w(ra) 0.339 9 p>0.05 ns esial b(ra)–w(ra) 4.901 9 p<0.01 hs alatal b(ra)–w(ra) 3.598 9 p<0.01 hs distal b(ra)–w(ra) 2.882 9 p<0.01 hs marginal gaps of metal-ceramic copings cast with the bellastar xl investment using the (rc, rlc, and ra) techniques are shown in figs.810. figures (11-13) show labial marginal gaps of the copings cast with wymvest investment using the rc, rlc, and ra techniques respectively. j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 24 figure 8: labial marginal gap of coping using the (rc) technique for bellastar, xl investment. yellow= brass die. black= marginal gap, gray= coping figure 9: labial marginal gap ofcoping using the (rlc) technique for bellastar xl investment. figure 10: labial marginal gap of coping using the (ra) technique for bellastarxl investment. figure 11: labial marginal gap of coping usingthe (rc) techniquefor wymvest investment figure 12: labial marginal gap of coping using the (rlc) technique for wymvest investment figure 13: labial marginal gap of coping usingthe (ra) technique for wymvest investment discussion effect of investing and burnout techniques the high mean of marginal gap caused by the bellastar xl investment when utilizing the ringless investing with conventional burnout technique (rlc), could be attributed to that when there was no ring liner employed , no expansion of the mold occurred during setting of the investment , a result which was in agreement with the findings of lombardas et al. (2) and ding et al.(10) since the expansion of the investment was found to be influenced by water absorption by the investment from the ring liners providingadditional hygroscopic expansion of the investment during its setting (16). the other cause of marginal discrepancy could be attributed to different degrees of surface roughness produced in the castings which were invested by phosphate-bonded investments since surface roughness was reported to be increased when using high mold temperatures (17). on the other hand, the anova test showed statistically non significant differences in the vertical marginal discrepancy of the copings invested by the wymvest investment regarding j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 25 each tested investing and burnout technique, a finding which agreed with konstantoulakis et al.(7)and schilling et al. (18) who reported that marginal gaps for castings made with an accelerated technique showed no statistical differences when compared with a conventional casting group. it was also supported by the findings of lombardas et al.(2) and ding et al.(10)that showed that the castings produced by the ringless technique can improve marginal seating of castings better than the conventional metal ring technique. on the other hand, it did not coincide with li et al. (19) findings where significant differences between the groups invested with metal rings (rc) and paper rings (rlc) were located. the wymvest investment with (rlc) technique resulted in less marginal discrepancies than using it with both (rc) and (ra) techniques, which demonstrated that it is possible to eliminate metal casting rings in order to provide greater expansion of the investment mold thus producing more precise fit for ni-cr alloy castings, a finding that coincided with engelman et al. (9) and lombardas et al. (2). the fluctuation of the observation of marginal discrepancy in the coping aspects (labial, mesial, lingual , distal) invested with bellastarxl and wymvest investments using the three different investing and burnout techniques lies in that, if the distortion had occurred during the investment setting expansion, spreading of the mesial and distal sides of the wax pattern would have happened thus causing the bending of the occlusal portion and resulting in poor fit of castings at the gingival floor and axial line angle margins of the die (20). effect of investments in regard for the investment materials, the statistical analysis showed highly significant differences between bellastar xl and wym vest investments using the (rlc) and (ra) techniques. in both investing and burnout techniques, wymvest investment produced copings that had the lowest mean of marginal gap while the highest mean related to bellastar xl investment. these differences could be attributed to the compositional differences of the investments’ formulations. investments may differ in terms of composition, particle size, heat transmission, wettability and so forth, and as a consequence, the castability of the dental casting alloys could be affected, which agreed with cohen et al. (21) findings. the other possible cause for the differences in the marginal fit among the two tested investment materials could be attributed to the effect of investments on the alloy castability. in general, it has been reported that incomplete castability results in an incomplete cast crown margins and therefore an increase in marginal discrepancy (14, 22). also those differences could be related to the alloy fusion temperature and alloy composition. these study findings agreed with duncan (22) who reported that the shrinkage of the alloys after casting related to the high fusing temperature that causedgreater fit discrepancies, and that the expansion of the investment wasn't adequate to compensate for the casting shrinkage of the alloy to obtain a good fit. on the other hand, copings made from bellastar xl and wym vest investments using the (rc) technique exhibited no significant differences between their results. such finding agreed with lombardas et al. (2) who found that there were no significant differences in the vertical marginal discrepancy of pfm copings produced with ringless and conventional casting technique and invested with two different phosphate-bonded investments mixed with their special liquids according to their manufacturer’s recommendations. the marginal gap mean values in the present study were less than 50µm for all tested investment–technique combinations. a similar amount of discrepancy was achieved in other studies (12-14,18,24,25) in which it was reported that the mean of marginal gap less than 50µm is considered clinically acceptable. this research also revealed that the wymvest investment generally produced less vertical marginal discrepancies (applying all three different investing and burnout techniques) than the bellastar xl investment. in order to achieve a better marginal fit, it seems that pfm copings invested by using the bellastar xl investment are better be cast using the conventional ring investing and burnout technique. under the conditions of this study, the following conclusions were drawn: 1. the wymvest investment generally produced less vertical marginal discrepancies (using the three different investing and burnout techniques) than the bellastar xl investment. 2. regarding the wymvest investment, both ringless investing with conventional burnout and ring investing with accelerated burnout techniques produced highly significant lower vertical marginal discrepancies for pfm copings than the bellastar xl investment. j bagh college dentistry vol. 26(3), september 2014 an evaluation of restorative dentistry 26 3. the highest mean of marginal discrepancy among all tested groups was scored by the bellastar xl investment in the ringless investing with conventional burnout technique, while the lowest mean was scored by the wymvest using the same technique. 4. in order to achieve a better marginal fit, it seems that pfm copings invested with the bellastar xl investment are better be cast using the conventional ring investing and burnout technique while the three investing and burnout techniques are acceptable for the wymvest investment. 5. marginal gap means presented by both tested investments (using the three different investing and burn-out techniques) can be considered clinically acceptable (less than 50µm). references 1. ushiwata o, de moraes jv, bottino ma, da silva eg. marginal fit of nickel-chromium copings before and after internal adjustments with duplicated stone dies and disclosing agent. j prosthet dent 2000; 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61(4): 418-24. 23. duncan jd. the casting accuracy of nickelchromium alloys for fixed prostheses. j prosthet dent 1982; 47(1):63-8. 24. oruc s, tulunoglu y. fit of titanium and base metal alloy ceramic crowns. j prosthet dent 2000; 83(3): 314-18. 25. zakaria mr, jassim hh. evaluation of the effects of porcelain firing cycles on the marginal fit changes of porcelain-fused-to-metal crowns constructed utilizing two different marginal designs and alloys. al-rafidain dent j 2003; 3(1):13-2. inaam final.doc j bagh college dentistry vol. 26(3), september 2014 periodontal condition orthodontics, pedodontics and preventive dentistry 129 periodontal condition in relation to nutritional status among kindergarten children in al-ramadi city/iraq inaam m. suhail, b.d.s. (1) wesal al-obaidi, b.d.s., m.sc. (2) abstract background: nutrition can affect periodontal disease through contributing to microbial growth in the gingival crevice, affecting the immunological response to bacterial antigens and assisting the repair mechanism of the connective tissue at the local site after injury from plaque and calculus. the aim of this study was to assess the prevalence of oral hygiene (plaque and calculus) and gingivitis in relation to age, gender and nutritional status. materials and methods: the sample included (444) kindergarten children at age of (4 and 5 years old) males and females from urban areas in al-ramadi city. the assessment of nutritional status was performed using anthropometric measurements (waterlow's indicator). plaque index of silness and loe (1964) used for plaque assessment, gingival index of loe and silness (1963) was used for recording gingival health condition. ramfjord index teeth (1959) were applied to assess oral cleanliness and gingival condition. results: the mean value of plaque, gingival and calculus indices were found (1.64±0.02, 0.38±0.02, 0.0004±0.0002 respectively). plaque index and gingival index were reported to be higher among malnourished children than well nourished described by waterlow´s indicator, with statistically highly significant differences. no significant difference was recorded in calculus index between the malnourished and well nourished children. conclusions: there was a direct relationship between periodontal condition and malnutrition. key words: periodontal condition, kindergarten, nutritional status, al-ramadi city. (j bagh coll dentistry 2014; 26(3):129-132). introduction gingivitis is the most common type of periodontal disease that seen in children which may start early in life and may increase in severity with age (1,2). many studies revealed that malnutrition affects the severity and extent of periodontal disease and reported a positive relation between protein energy malnutrition and gingivitis among children (3-6). the need for deeper understanding on the influence of protein energy malnutrition on the periodontal condition and there is no previous iraqi studies concerning the relation between nutritional status and periodontal condition among kindergarten children in al-ramadi city, it was decided to conduct this study. materials and methods this study was conducted among kindergarten children aged 4-5 years in al-ramadi city in iraq. the total sample composed of (444) children who were chosen randomly from different kindergarten in the city. permission was obtained from the alramadi education institution in order to meet subjects with no obligation, the purpose of the study was explained to the kindergarten authority to ensure full cooperation, and also special consents were distributed to parents to obtain permission for including their children in the study with full cooperation. (1) m.sc. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. children with serious systemic diseases and/or uncooperative were not examined. the assessment of nutritional status was performed using anthropometric measurements (waterlow's indicator). plaque index of silness and loe used for plaque assessment (7), gingival index of loe and silness was used for recording gingival health condition (8). ramfjord index teeth were applied to assess oral cleanliness and gingival condition (9). analysis and processing of the data were carried out using spss version 19, statistical tests used are anova test and lsd test. p-values less than 0.05 were considered as statistically significant, while p-values less than 0.01 were recorded as a highly significant. results the mean value of plaque index was found (1.64±0.02). mean plaque index according to nutritional status by age and gender is illustrated in table (1, 2, 3, 4). these tables shows that for the total sample the mean plaque index was higher among short term, dwarf and long term children than well nourished described by waterlow´s indicator, with statistically highly significant differences (p < 0.01). data analysis in each age and each gender showed that the highly significant difference is found among total female, total male, total 4 years and total 5 years described by waterlow´s indicator. mean calculus index for the total sample was found (0.0004±0.0002). mean calculus index according to nutritional status by age and gender is illustrates in table (5). this table shows that for j bagh college dentistry vol. 26(3), september 2014 periodontal condition orthodontics, pedodontics and preventive dentistry 130 the total sample the mean calculus index was higher among well nourished and dwarf children than short term and long term children described by waterlow´s indicator, with statistically no significant differences (p > 0.05). data analysis in each age and each gender showed that the mean calculus index was higher among 5 years than among 4 years with no significant difference, on the other hand, total normal males had mean calculus index higher than total normal females and the opposite picture was seen regarding dwarf children with no significant difference (p > 0.05). the mean value of gingival index for the total sample was found (0.38±0.02). mean value of gingival index according to nutritional status indicators by age and gender is shown in tables (6, 7, 8, 9, 10). the mean value of gingival index for the total sample among short term, dwarf and long term children were found to be higher than well nourished children described by the waterlow´s indicator, with statistically highly significant difference (p < 0.01). data analysis showed that the well nourished, dwarf and long term males had mean gingival index higher than well nourished, dwarf and long term females and the opposite picture was seen regarding long term children. for all nutritional grades the mean gingival index was higher among children aged 4 years than among 5 years with significant difference. table 1: plaque index according to nutritional status indicator by age and gender ns non-significant p>0.05, * significant p<0.05, ** highly significant p<0.01 table 2: lsd according to nutritional status indicator for four years of age nutritional status male female both s.e sig. s.e sig. s.e sig. normal-short term 0.21 0.04 0.24 0.19 0.16 0.02* normal-dwarf 0.13 0.02 0.13 0.001** 0.09 0.00** normal-long term 0.19 0.02 0.22 0.97 0.14 0.09 short term-dwarf 0.23 0.66 0.26 0.55 0.17 0.87 short term-long term 0.27 0.94 0.32 0.31 0.20 0.53 dwarf-long term 0.21 0.57 0.25 0.05 0.16 0.33 * significant p<0.05, ** highly significant p<0.01 table 3: lsd according to nutritional status indicator for the five years of age nutritional status female total s.e sig. s.e sig. normal-short term 0.23 0.00** 0.23 0.001** normal-dwarf 0.16 0.001** 0.12 0.000** normal-long term 0.23 0.01* 0.17 0.03* short term-dwarf 0.27 0.32 0.26 0.23 short term-long term 0.32 0.44 0.28 0.12 dwarf-long term 0.27 0.93 0.21 0.55 * significant p<0.05, ** highly significant p<0.01 age (year) gender nutritional status comparison normal short term dwarf long term no. mean ±s.e s.d. no. mean ±s.e s.d. no. mean ±s.e s.d. no. mean ±s.e s.d. d.f. f-value 4 males 62 1.65 0.07 0.57 7 2.08 0.17 0.46 20 1.98 0.09 0.42 9 2.10 0.18 0.54 3 3.822* females 70 1.64 0.07 0.64 6 1.96 0.20 0.49 23 2.12 0.07 0.37 7 1.64 0.17 0.46 3 4.28** both 132 1.65 0.05 0.61 13 2.03 0.12 0.46 43 2.05 0.06 0.39 16 1.90 0.13 0.55 3 6.977** 5 males 122 1.49 0.05 0.56 0 / / / 8 1.88 0.19 0.54 5 1.60 0.30 0.69 2 n.s females 80 1.39 0.06 0.59 6 2.26 0.11 0.28 13 1.99 0.13 0.48 6 2.01 0.17 0.43 3 9.421** both 202 1.45 0.04 0.57 6 2.26 0.11 0.28 21 1.95 0.10 0.49 11 1.82 0.17 0.57 3 9.588** total males 184 1.54 0.04 0.57 7 2.08 0.17 0.46 28 1.95 0.08 0.45 14 1.92 0.16 0.62 3 7.308** females 150 1.51 0.05 0.62 12 2.11 0.11 0.41 36 2.07 0.06 0.41 13 1.81 0.13 0.47 3 12.329** both 334 1.53 0.03 0.59 19 2.10 0.09 0.42 64 2.02 0.05 0.43 27 1.87 0.10 0.55 3 19.591** j bagh college dentistry vol. 26(3), september 2014 periodontal condition orthodontics, pedodontics and preventive dentistry 131 table 4: lsd according to nutritional status indicator to the total number of age nutritional status male female both s.e sig. s.e sig. s.e sig. normal-short term 0.23 0.30 0.14 0.000** 0.13 0.00** normal-dwarf 0.12 0.04* 0.09 0.19 0.07 0.02* normal-long term 0.16 0.006** 0.14 0.19 0.11 0.004** short term-dwarf 0.25 0.97 0.16 0.000** 0.14 0.005** short term-long term 0.27 0.43 0.19 0.002** 0.16 0.13 dwarf-long term 0.19 0.28 0.15 0.68 0.12 0.21 * significant p<0.05, ** highly significant p<0.01 table 5: calculus index according to nutritional status indicator by age and gender ns non-significant p>0.05 table 6: gingival index according to nutritional status indicator by age and gender ns non-significant p>0.05, * significant p<0.05, ** highly significant p<0.01 table 7: lsd according to nutritional status indicator to the total number of four years of age nutritional status s.e sig. normal-short term 0.18 0.002** normal-dwarf 0.11 0.22 normal-long term 0.17 0.002* short term-dwarf 0.20 0.03* short term-long term 0.24 0.85 dwarf-long term 0.18 0.03* * significant p<0.05, ** highly significant p<0.01 table 8: lsd according to nutritional status indicator to the total number of male nutritional status s.e sig. normal-short term 0.23 0.30 normal-dwarf 0.12 0.04* normal-long term 0.16 0.006** short term-dwarf 0.25 0.97 short term-long term 0.27 0.43 dwarf-long term 0.19 0.28 * significant p<0.05, ** highly significant p<0.01 age (year) gender nutritional status comparison normal short term dwarf long term no. mean ±s.e s.d. no. mean±s.es.d. no. mean ±s.e s.d. no. mean ±s.e s.d. d.f. f-value 4 males 62 0.0000 0.0000 0.000 7 0 0 0 20 0.0000 0.0000 0 9 0 0 0 / / females 70 0.0000 0.0000 0.000 6 0 0 0 23 0.0000 0.0000 0 7 0 0 0 / / both 132 0.0000 0.0000 0.000 13 0 0 0 43 0.0000 0.0000 0 16 0 0 0 / / 5 males 122 0.0005 0.0004 0.005 0 / / / 8 0.0000 0.0000 0 5 0 0 0 2 n.s females 80 0.0000 0.0000 0.000 6 0 0 0 13 0.0077 0.0077 0.027 6 0 0 0 3 n.s both 202 0.0003 0.0003 0.004 6 0 0 0 21 0.0048 0.0047 0.021 11 0 0 0 3 n.s total males 184 0.0003 0.00033 0.004 7 0 0 0 28 0.0000 0.0000 0 14 0 0 0 3 n.s females 150 0.0000 0.000 0.000 12 0 0 0 36 0.0028 0.0027 0.01 13 0 0 0 3 n.s both 334 0.0002 0.0002 0.003 19 0 0 0 64 0.0016 0.0015 0.012 27 0 0 0 3 n.s age (year) gender nutritional status comparison normal short term dwarf long term no. mean ±s.e s.d. no. mean ±s.e s.d. no. mean ±s.e s.d. no. mean ±s.e s.d. d.f. f-value 4 males 62 0.46 0.09 0.71 7 0.58 0.25 0.67 20 0.64 0.15 0.69 9 1.24 0.31 0.94 3 3.021* females 70 0.32 0.06 0.50 6 1.41 0.33 0.83 23 0.42 0.09 0.43 7 0.51 0.24 0.65 3 8.109** both 132 0.39 0.05 0.61 13 0.96 0.23 0.83 43 0.52 0.08 0.57 16 0.92 0.22 0.88 3 5.866* 5 males 122 0.28 0.04 0.44 0 / / / 8 0.46 0.21 0.59 5 0.01 0.01 0.03 2 n.s females 80 0.22 0.04 0.42 6 0.71 0.32 0.80 13 0.33 0.12 0.43 6 0.39 0.15 0.38 3 n.s both 202 0.26 0.03 0.43 6 0.71 0.32 0.80 21 0.38 0.10 0.49 11 0.22 0.10 0.33 3 n.s total males 184 0.34 0.04 0.55 7 0.58 0.25 0.67 28 0.59 0.12 0.66 14 0.80 0.25 0.96 3 3.766** females 150 0.27 0.03 0.46 12 1.06 0.24 0.85 36 0.39 0.07 0.43 13 0.45 0.14 053 3 10.046** both 334 0.31 0.02 0.51 19 0.88 0.18 0.81 64 0.47 0.06 0.54 27 0.63 0.15 0.79 3 9.569** j bagh college dentistry vol. 26(3), september 2014 periodontal condition orthodontics, pedodontics and preventive dentistry 132 table 9: lsd according to nutritional status indicator to the total number of female nutritional status s.e p value normal-short term 0.1477 0.000** normal-dwarf 0.0914 0.19 normal-long term 0.142 0.19 short term-dwarf 0.1641 0.000** short term-long term 0.197 0.002** dwarf-long term 0.1593 0.68 * significant p<0.05, ** highly significant p<0.01 table 10: lsd according to nutritional status indicator to the total number of age nutritional status s.e p value normal-short term 0.13 0.000** normal-dwarf 0.07 0.028* normal-long term 0.11 0.004** short term-dwarf 0.14 0.005** short term-long term 0.16 0.13 dwarf-long term 0.12 0.21 * significant p<0.05, ** highly significant p<0.01 discussion there is no previous epidemiological study concerning population in al-ramadi city, so results of the present study can be considered as a base line data for comparison with other studies in iraqi governorates and different parts of the world. the results revealed that the mean plaque index among malnourished children (short term, dwarf and long term) were higher than among well nourished children, this finding is in agreement with previous iraqi studies (5,10-12). malnutrition is an outcome of low socioeconomic condition (13) and these socioeconomic factors affect plaque index by leading poor brushing behavior and ignorance of malnourished children to their oral hygiene (14) also malnutrition may weaken the immune response leading to health problem and this may be associated with increased thickness of dental plaque (4). in the present study, the result showed that both well nourished and malnourished children suffer from gingival inflammation but the prevalence and severity of gingivitis was recorded higher among malnourished groups than well nourished once. this result is in agreement with many studies (3,5,10-12). they attributed the occurrence of gingivitis to the deterioration in nutritional status (15). in the present study, calculus was present in a low percentage in both well nourished and mal nourished children with no significant difference but still well nourished children had a higher calculus index than malnourished of sure this is because poor brushing behavior and oral cleanliness among the well nourished or could be due to accumulation of dental plaque around the badly carious tooth as a sequence to unilateral chewing habit due to dental pain (3) but, we need further investigation to clarify this finding. references 1okada k, kato t, ishihara k. involvement of periodontopathic biofilm in vascular diseases. oral dis 2004; 10: 5–12. 2rao a. principle and practice of pedodontics. 2nd ed. new delhi; 2008. 3al-obaidi w. oral health status in relation to nutritional status among kindergarten children in baghdad. iraq. a master thesis, college of dentistry, university of baghdad, 1995. 4dittmann k, grupe g. biochemical and palaeopathological investigations on weaning and mortality in the early middle ages. anthropo-anz 2000; 58: 345-55. 5droosh mk. protein energy malnutrition in relation to oral health condition among 6 and 9 years old primary school children in sulaimania city of iraq. a master thesis, college of dentistry, university of baghdad, 2007. 6hassan z. the effect of nutritional status on dental health, salivary physiochemical characteristics and odontometric measurement among five years old kindergarten children and fifteen years old students. ph.d. thesis, college of dentistry, university of baghdad, 2010. 7silness j, loe h. periodontal disease in pregnancy. correlation between oral hygiene and periodontal condition. acta odont scand 1964; 22: 121-35. 8loe h, silness j. periodontal disease in pregnancy i. acta odonto scand 1963; 21: 533-51. 9ramfjord sp. indices for prevalence and incidence of periodontal disease. j periodontol 1959; 30: 51-9. 10diab bs. nutritional status in relation to oral health condition among 10 years primary school iraqi children in the middle region of iraq. ph.d. thesis, college of dentistry, university of baghdad, 2003. 11murad no. dental caries, gingival health condition and enamel defect in relation to nutritional status among kindergarten children in sulaimania city. a master thesis, college of dentistry, sulaimania university, 2007. 12jabber wm. oral health status in relation to nutritional status among kindergarten children 4-5 years in alkut city/ iraq. a master thesis, college of dentistry, university of baghdad, 2008. 13fao/who. assessment, analyzing and monitoring nutrition situations. international conference on nutrition. 1992a. theme paper (8). rome italy. 14anagnou-vareltzides a, tsami a, mitsis f. factors influencing oral hygiene and gingival health in greek school-children. community dent oral epidemiol 1983; 11: 321-4. 15mahan lk, escott-stump s. krause's food and nutrition therapy. 12th ed. elsevier health sciences: 2008. j bagh college dentistry vol. 30(3), september 2018 bacteriological findings 13 bacteriological findings within internal implant hole following flapless implant placement khudair ali abd, b.d.s., h.d.d. (1) basima gh. ali, b.d.s., m.sc. (2) abbas s.al-mizraqchi, m.sc., ph.d. (3) abstract back ground: microbial penetration inside the implant's internal hole creates a bacterial reservoir that is related with an area of inflamed connective tissue opposite the fixture-abutment junction and this can affect the health of the peri-implant tissue. aims of the study: evaluate the types aerobic and anaerobic bacterial count-percentage and difference between aerobic and anaerobic microflora in the implant screw hole three months after implant placement. monitor the periodontal health status of all patients, throughout the study. material and methods: study methodology; eight partially edentulous patients received 20 dental implants and these implants done with flapless surgical procedure. all patients examined clinically to determined their oral health status by examination of their plaque index, gingival index and bleeding on probing, each two weeks for 90 days (8visits) throughout the study period. three months after that, the plaque sample collected from the internal hole of fixture and transfer to bacterial investigation and assessment the amount of anaerobic and aerobic bacteria. results: although the anaerobic viable count is higher than that of aerobic, but with statistically not significant difference between those counts (p>0.05). keywords: screw hole, flapless surgical implant placement, bacterial count, aerobic and anaerobic bacteria. (j bagh coll dentistry 2018; 30(3): 13-16) introduction studies of dental implants over the years have showed great dependability for the success rates of implant treatment (1). longstanding implant success is highly dependent on adaptation of the implant with oral soft and hard tissues. commonly, the crestal bone at the implant–tissue interface is the early point of surgical trauma and tissue breakdown. at this instant there is no single flap design that functions as the main approach for all single implant surgery, and as the need for esthetics practices rises with a little aggressive system, so, extremely, confirms the instability in flap design (2). implant dentistry is not an easy work, but it responsible for obtaining best esthetic, function and phonetic outcomes, also responsible for increasing the stability of alveolar bone with the peri-implant soft tissues. (3) in deference to the several factors that cause failure of dental implants for example bone condition, occlusion and so on, numerous studies supported that microbial infections could have serious consequences lead to failure in dental implants prosthesis. for most implant systems, micro leakage in dental implants may cause mucositis within a short extent from the alveolar bone crest. (4) infiltration of bacteria in the implant's internal screw cavity forms a reservoir of bacterial flora university of baghdad. that is associated with an area of connective tissue inflammation opposing the abutmentfixture connection and this can influence with the periimplant tissue health (5). microorganisms colonizing surfaces are progressively developed into complex biofilms. species within the biofilm interrelate specially with each other. such as, initial colonists, for example actinomyces or streptococcus species, are necessary for the adhesion of late -colonizing gram-negative species. a sufficient cooperative maintenance care for patients with dental implants has an essential function in attaining longstanding success for implant-supported restorations (6). materials & methods study sample the sample included patients who attended the dental unit/department of oral and maxillofacial surgery in the teaching hospital of college of dentistryuniversity of baghdad for the purpose of implant placement. a total of 20 dental implants(dis) in 8 iraqi patients, 4 males and 4 females, age ranged from 30 to 45 years that fulfilled the inclusion criteria were recruited for this study. inclusion criteria: 1patient who were partially edentulous (patients requiring at least two teeth replacement in the anterior, premolar and posterior region). 2systemically healthy 3free of active caries and active periodontitis 4smokers: patients smoke less than 10 cigarettes per day (light smokers). (7) university of baghdad. (3) professor, department of microbiology, college of dentistry, (1) ministry of health, baghdad, iraq. (2) professor, department of periodontics, college of dentistry, j bagh college dentistry vol. 30(3), september 2018 bacteriological findings 14 5patients who were well motivated for implant treatment and maintaining good oral hygiene and follow a regular periodontal maintenance protocol. exclusion criteria 1edentulism. 2medically compromised patients such as uncontrolled diabetes, bleeding disorders, osteoporosis; patients on radiation therapy; immunocompromised states and any disease affecting on bone healing. 3active periodontitis and chronic periodontitis with pocket more than 4mm and need current periodontitis treatment. 4smokers: patients regularly smoked at least 10 cigarettes on average per day, for the last five years. 5any medications that compromise or effect on the healing process of bone like corticosteroids. 6chronic alcoholism. 7history and clinical evidence of parafunctional habits (bruxism, clenching). 8tumor or metastatic disease. 9allergy to chlorhexidine gluconate 10patient taken antibiotic prior to culture at the 2nd stage of implant for at least 15 days or 1 month. 11pregnant women. clinical examination: 1extraoral examination 2intraoral examination 3before surgery and at each visit patient's motivation and oral hygiene instruction as well as scaling were repeated 4clinical periodontal parameters examination done every 2 weeks for 4 months (8 visits) for all patients include: -assessment of plaque index (pli) (8) -assessment of gingival index (gi) (9) -assessment of bleeding on probing (bop) (10) 5radiographic examination: a pre-operative orthopantomography (opg) was obtained for all patients in almaghreb specialized dental center for radiographic examinations. surgical procedure before surgery, patients were instructed to rinse with 0.12% chx solution for 1 min. as part of the standard surgical protocol and the skin was scrubbed with povidone-iodine solution as antiseptic agent. the surgical site was anesthetized and implants were placed in site previously examined and according to a studied treatment plane in respect to the demand of the patients. flapless surgical design was selected. before placement of the healing abutment, all implant screw holes were rinsed with about 20 ml of sterile saline solution by disposable syringe and dried using surgical suction, thus preventing further contamination of the screw hole with saliva or blood. the healing abutments were then screwed into place by hex driver with the same torqueing protocol for all flapless implant. bacteriological examination: 1-preparation of the following media:  phosphate buffer saline (pbs)  culture media preparation: brain heart infusion agar (bhi)  mannitol salt agar 2-specimen collection: plaque samples were collected from the internal screw holes under standard condition, approximately 3 months after surgical placement using sterile micro brush and then the brushes immediately dropped into screwed universal tube containing pbs. 3-culturing technique: the collected sample were mixed using vortex mixer (griffin and george ltd. england) for 2-3 minutes. tenfold steps of serial dilutions were prepared using sterile phosphate buffer saline. from each dilution (103, 10-5), 0.1 ml was withdrawn and then, inoculate in to the petri dishes contain bhi blood agar media, and spread by using sterile microbiological spreader on the plates of bhiblood agar. (11) then incubate aerobically and anaerobically. 4-enumeration of bacterial colonies (count)colony forming unit per one mil liter(cfu\ml): identification of most common bacterial colonies by:  morphological characteristics using gram’s stains  biological tests (catalase test (h2o2), oxidase test, and mannitol salt agar). a statistical analysis using statistical package for social science (spss) version 21. descriptive statistics includes (percentage, median and mean rank) in tables. inferential analysis which include statistical test of non-parametric data as friedman and mann whitney u tests were used. j bagh college dentistry vol. 30(3), september 2018 bacteriological findings 15 results throughout all 8 visits a dramatic decrease in pli and gi with highly significant changes during visits (table 1). median of pli changes from 1.280 at the first visit to 0.900 at the eight visit. while gi decrease from (1.595) at first visit to (1.045) at eight visit, which is the lowest score. table 2 shows the descriptive and statistical analysis of bop changes throughout all visits. appears that a significant decrease of bop median percentage during visits. the highest median in a first visit 59.990 decrease to 5.250 the lowest median of bop at the last visit. results in table 3 illustrates the descriptive and statistical tests of both aerobic and anaerobic viable count (cfu\ml) in the examined medias. although the mean of anaerobic viable count (24.337) is higher than that count of aerobic (10.158), but with statistically not significant difference between those counts (p>0.05). the most common bacteria isolated from implant after 3 months in aerobic and anaerobic media were streptococcus spp., staphylococcus aurous, g -ve diplococcus, g +ve baclli and g ve bcilli., their percentage under aerobic condition were 50%, 36%, 8%, 3% and 3%. while under anaerobic condition were 30%, 50%, 10%, 3%, 4%. also entercoccus fecalis was cultured in anaerobic condition 3% (table 4). table 1: descriptive and statistical test of plaque index (pli) and gingival index (gi) change during visits. index visits median mean rank friedman test chi square *df p value pli 1 1.280 7.65 49.717 7 0.000 hs 2 1.020 6.00 3 1.000 5.55 4 1.000 4.55 5 1.000 4.85 6 .900 2.45 7 .900 2.85 8 .900 2.10 gi 1 1.595 7.50 36.926 7 0.000 hs 2 1.370 6.00 3 1.240 5.50 4 1.165 4.65 5 1.095 3.35 6 1.090 3.95 7 1.055 2.70 8 1.045 2.35 hs=highly significant at p<0.01. *df =degree of freedom table 2: descriptive and statistical test of median percentage of surfaces with bleeding on probing (bop) score 1 change during visits. visits median mean rank friedman test chi square df p value 1 59.990 7.90 65.734 7 0.000 hs 2 37.900 6.55 3 25.000 6.20 4 16.540 5.20 5 10.200 3.95 6 8.300 3.00 7 6.100 1.80 8 5.250 1.40 hs=highly significant at p<0.01. table 3: descriptive and statistical test of viable count between aerobic and anaerobic bacteria after 3 months of insertion 20 di. p-value z bacterial groups descriptive statistics 0.512 *ns 0.685 anaerobic aerobic 1.100 1.040 minimum 98.000 51.000 maximum 7.000 3.250 median 16.60 14.40 mean rank *ns=non-significant at p>0.05 table 4: the most common isolated aerobic and anaerobic bacteria in examined media / culture. anaerobic bacteria aerobic bacteria 30% streptococcus spp. 50% streptococcus spp. 50% staphylococcus aurous 36% staphylococcus aurous 10% g –ve diplococcus 8% g –ve diplococcus 3% g +ve bcilli 3% g +ve bcilli 4% g –ve bcilli 3% g –ve bcilli 3% enterococcus fecalis discussion implants inserted with the closed technique near half of it become contaminated during the surgical procedure (12). after healing abutments placement, the microbial flora level extremely increases and most screw cavities are contaminated 6 weeks after they are exposed, suggesting that both surgery and microleakage contribute to the contamination. as no statistical difference between aerobic and anaerobic culture was documented, the bacterial contamination is thought to be mostly facultative anaerobic. to identity the frequency of occurrence of gram negative g -ve species, gram staining was conducted on the cultured samples. j bagh college dentistry vol. 30(3), september 2018 bacteriological findings 16 unexpectedly, samples presented the gram positive g +ve coccoid species were the most common species (staphylococcous and streptococcus). these species are the common initial colonizers belong to streptococcal species, for example streptococcus gordonii and streptococcus sanguinis. modern studies have also directed that in healthy implant sites, gram-positive cocci have the greatest proportion of finding (13), which is corresponding with our results. a studies has examined the bacterial species found in the biofilm present on the restorative components and in the internal parts of implants (14,15). these studies indicated that these restorative components and internal parts were highly contaminated. all implants in the study were regarded to be free of peri-implantitis and radiographic estimation did not exhibit signs of significant bone loss beyond what is corresponding with crestal bone regeneration. also the oral hygiene of the patient remain good and this help in maintaining the health of the periimplant tissue over the observative period. any bacteriological colonization should permanently be regarded a longstanding risk factor and should be removed. conclusion we propose that prevention of implant screw hole contamination should be included in the standards of care in implant dentistry. references 1. jung re, zembic a, pjetursson be, zwahlen ms, thoma d. systematic review of the survival rate and the incidence of biological, technical, and aesthetic complications of single crowns on implants reported in longitudinal studies with a mean follow‐up of 5 years. clin oral implant res. 2012;23(s6):2-1. 2. askary aes. reconstructive aesthetic implant surgegy. wiley-blackwell; 2003. 3. dawson a, chen s, buser d, cordaro l, martin w, belser u. the sac classification in implant dentistry. quintessenz verlag; 2010. 4. zwiad aa, al-nesairy am, ghanem nm. the influence of chlorhexidine mouthwash on oral microorganisms in existence of implant prosthesis. j dent impl. 2014;4(2):149. 5. persson lg, lekholm u, leonhardt å, dahlen g, lindhe j. bacterial colonization on internal surfaces of brånemark system® implant components. clin oral impl res. 1996;7(2):90-5. 6. lang np, nyman sr. supportive maintenance care for patients with implants and advanced restorative therapy. periodontol 2000.1994;4(1):119-26. 7. maffei g, brouwer n, dolman km, van der velden u, roos d, loos bg. plasma levels of mannanbinding lectin in relation to periodontitis and smoking. j periodontol. 2005; 76(11): 1881-9. 8. silness j, löe h. periodontal disease in pregnancy ii. correlation between oral hygiene and periodontal condition. acta odontol scand. 1964;22(1):121-35. 9. löe h. the gingival index, the plaque index and the retention index systems. j periodontol. 1967; 38(6 part ii):610-6. 10. newbrun e. indices to measure gingival bleeding. j periodontol. 1996;67(6):555-61. 11. al-mizraqchi a. adherence of mutans streptococci on teeth surfaces: microbiological and biochemical studies. ph.d. thesis, college of science, university of al-mustansiriya, 1998. 12. groenendijk e, dominicus jj, moorer wr, aartman ih. microbiological and clinical effects of chlorhexidine enclosed in fixtures of 3i‐titamed® implants. clin oral impl res. 2004;15(2):174-9. 13. shahabouee m, rismanchian m, yaghini j, babashahi a, badrian h, goroohi h. microflora around teeth and dental implants. dent res j. 2012; 9(2):215. 14. cosyn j, van aelst l, collaert b, persson gr, de bruyn h. the peri‐implant sulcus compared with internal implant and suprastructure components: a microbiological analysis. clin impl dentist relat res. 2011;13(4):286-95. 15. do nascimento c, monesi n, ito iy, issa jp, de albuquerque junior rf. bacterial diversity of periodontal and implant-related sites detected by the dna checkerboard method. eur j clin microbiol inf dis. 2011;30(12):1607-13. الخالصة االختراق الميكروبي داخل الثقب الداخلي للزرعه المعوضة للسن يؤدي الى نمو البكتيريا التي ترتبط مع التهاب النسيج المحيط و المقابل :خلفية الغرسة االساسيه مع األبوتمنت وهذا يمكن أن يؤثر على صحة األنسجة المحيطة بالزرعه.التصال تقييم النسبة المئوية العداد البكتريا الهوائية و الالهوائية، والفرق بين البكتيريا الهوائية والالهوائية في ثقب مسمار الزرعة بعد أهداف الدراسة: سن، ومراقبة الحالة الصحية للثة لجميع المرضى، طوال مدة الدراسة البالغه ثالثة اشهر.ثالثة أشهر من وضع الزرعة المعوضة لل تزرع تطبيقيا مع اإلجراء الجراحي بدون رفع لثة لألسنانزرعة 02فقدوا اسنانهم جزئيا تلقى ثمانية مرضى ممن منهجية الدراسة :المواد والطرق م الصحية عن طريق فحص مؤشر الصفيحة الجرثومية ,مؤشر التهاب اللثة , مؤشر النزف عند جميع المرضى تم فحصهم سريريا لتحديد حالته , التسبيرومؤشر عمق الجيوب الخاص بهم كل أسبوعين طوال فترة الدراسة. الفحص البكتريولوجي بعد ثالثة أشهر من غرس الزرعة تم اخذ عينة البالك التي تم جمعها من الثقب الداخلي للزرعة االساسية وإرسالها إلى واختبار اعداد البكتيريا الهوائية والالهوائية. (، ولكن اليجود فرق 01..2.( أعلى من عدد البكتيريا الهوائية )03.442العدد القابل للحياة للبكتيريا الالهوائية )على الرغم من أن متوسط النتائج: (.p> 0.05ذات داللة إحصائية بين تلك التعدادات ) 20 development of sinusitis after sinus floor elevation surgery: a systematic review huda moutaz asmael, b.d.s. m.sc. (1) abstract background: maxillary sinusitis can arise after sinus floor elevation surgery and should be treated immediately to prevent further complications which included dental implants failure, graft lost, and oro-antral fistula. this is the first systematic review to assess the incidence, causes, and treatment of sinusitis after sinus lift surgery. materials and methods: an electronic search included medline (pubmed) data base site was carried out for articles involving development of sinusitis after sinus lift surgery from september 1997 up to april, 8, 2017. the search was done and reviewed by two independent authors. results: the total results of electronic search were (182) abstracts and articles, the extracted articles which involved development of sinusitis after sinus lift surgery were (25) studies. of the 25 articles only (8) articles fit the inclusion criteria. maxillary sinusitis was calculated for all selected studies and it was ranged from 2.12% to 12.7% with average of 5.4 %. conclusion: maxillary sinusitis could be developed after sinus lift surgery with average of 5.4 % and the patients with previous maxillary sinus disease showed to be at increased risk of sinusitis after sinus lift surgery. keywords: sinusitis after sinus lift; sinus lift complication; systematic review. (received: 26/7/2017; accepted: 23/8/2017) introduction one of the major postoperative complications after sinus floor elevation surgery is sinusitis. the post-surgical sinusitis etiology can arise from two origins; either from earlier chronic infection of the maxillary sinus which is triggered by post-surgical inflammatory changes or from communication with bacteria of oral cavity via perforation of schneiderian membrane (1). it is very important to treat sinusitis after maxillary sinus lift surgery as soon as possible because the infection may spread to other paranasal sinuses. in addition to that sinus infection may cause oro-antral fistula, loss of graft material and failure of dental implants (2-6). the aims of this study were to present the results of the previous studies which involved development of sinusitis after sinus lift surgery and to assess the incidence of the maxillary sinusitis after sinus floor elevation surgery. materials and methods an electronic search was carried out in medline (pubmed) data base site for articles published in the literature from september 7991 up to april, 8, 1077 and limited to studies on human trials. the following keywords were used in the search: sinusitis after sinus lift, sinus lift infection, sinus lift complication and sinusitis after sinus floor elevation surgery. (1) assistant lecturer at department of oral and maxillofacial surgery, college of dentistry, university of baghdad. the search process is demonstrated in diagram 1. inclusion criteria: 1. researches involving rct (randomized clinical trials, prospective and retrospective studies. 2. studies involving sinusitis development after sinus lift surgery. 3. studies with at least 6 months of follow-up after sinus lift surgery. 4. studies on humans only. 5. articles in english language only. 6. healthy patients with no systemic diseases that may influence on the maxillary sinus health. exclusion criteria: 1case reports and case series with less than 10 patients. 2studies published in other languages than english. 3experimental studies (on animals). 4studies involving complications after sinus lift other than maxillary sinusitis. 5studies with less than 6 months follow-up period. 6patient with systemic diseases that may had an effect on maxillary sinus health. selection of studies titles and abstracts of the articles were examined initially by two independent reviewers (authors) for the chance of inclusion in this systematic review. j bagh college dentistry vol. 30(4), december 2018 development of ali riyadh raouf, b.d.s. (2) (2) ministry of health, baghdad, iraq ali khalid saaed, b.d.s. (2) 21 diagram 1: the search process. results the total results of electronic search were 182 abstracts and articles. the reviewed abstracts were 130, the extracted articles which involved development of sinusitis after sinus lift surgery were 25 studies. of the 25 articles 17 studies were excluded and only 8 articles which fit the inclusion criteria were involved in this research. the characteristic data for each study was summarized in table 1. the average of sinusitis was calculated for all studies and it was 5.4 %. seventeen articles were excluded from this research because of the following points: 1five articles were excluded because they were case reports. 2one study excluded because it was involving various types of localized lateral alveolar ridge and/or sinus floor augmentation procedures performed before implant placement. 3seven articles were excluded because of missing data and not standardized criteria. 4three articles were excluded because they written in german language. 5one article was excluded because the sinusitis complication was not related only to sinus lift surgery but to other causes like odontogenic causes. discussion development of sinusitis after sinus lift surgery among the selected studies in this research ranged from 2.12% to 12.7% (10,14). causes of sinusitis (according to the authors in the selected studies) were as follow: 1sinusitis due to sinus membrane perforation as mentioned in two studies (10,12). nolan et al. (10) reported sinusitis with percentage of (12.7%) in his study. of the sinuses presented with sinusitis, 85% have schneiderian membrane perforation. in contrary three other studies reported that the most common intraoperative complication was schneiderian membrane perforation, which did not show any relation to postoperative sinusitis (7,9,14). 2sinusitis due to assumed long implant 10-16 mm as reported in one study (8). 3 the risk of postoperative sinusitis was increased in patients who had previous chronic sinusitis and in cases in which a large amount of graft was used for sinus augmentation as reported in one study (11) 4risk of postoperative sinusitis was associated with sinus elevation width, smoking and sinus membrane perforation (12). conclusion according to this research, sinusitis can developed after sinus lift surgery with average of 5.4 %. patients with previous maxillary sinus diseases appeared to be at increased risk of sinusitis development after sinus lift surgery. references 1. stuart j. dental implant complications: etiology, prevention, and treatment. john wiley & sons, 2015. 2. quiney re, brimble e, hodge m. maxillary sinusitis from dental osseointegrated implants. j laryngol otology. 1990: 104: 333–4. 3. timmenga nm, raghoebar gm, van weissenbruch r. maxillary sinusitis after augmentation of the maxillary sinus floor: a report of 2 cases. j oral maxillofac surg. 2001: 59: 200–4. 4. alkan, alper, nükhet çelebi, and burcu baş. acute maxillary sinusitis associated with internal sinus lifting: report of a case. eur j dent 2008; 69-72. 5. li j, wang hl. common implant-related advanced bone grafting complications: classification, etiology, and management. impl dentist. 2008: 17: 389–401. 6. chiapasco m, felisati g, zaniboni m, pipolo c, borloni r, lozza p. the treatment of sinusitis following maxillary sinus grafting with the association of functional endoscopic sinus surgery (fess) and an intra‐oral approach. clin oral impl res. 2013;24(6):623-9. 7. timmenga, nicolaas m.. maxillary sinus function after sinus lifts for the insertion of dental implants. j oral maxillofac surg 1997; 55(9): 936-9. 8. cannizzaro, gioacchino, . early implant loading in the atrophic posterior maxilla: 1-stage lateral versus crestal sinus lift and 8 mm hydroxyapatite-coated implants. a 5-year randomised controlled trial. eur j oral implant 2013; 6: 1. 9. vazquez, jose c. moreno, complication rate in 200 consecutive sinus lift procedures: guidelines for prevention and treatment. j oral maxillofac surg 2014; 72(5): 892-901. 10. nolan, patrick j., katherine freeman, , richard a. kraut. correlation between schneiderian membrane 17 articles excluded 8 articles fit the inclusion criteria j bagh college dentistry vol. 30(4), december 2018 development of 22 perforation and sinus lift graft outcome: a retrospective evaluation of 359 augmented sinus. j oral maxillofac surg 2014; 72(1): 47-52. 11. kayabasoglu, gurkan, . a retrospective analysis of the relationship between rhinosinusitis and sinus lift dental implantation. head face med 2014; 10(1): 53. 12. schwarz, linda, . risk factors of membrane perforation and postoperative complications in sinus floor elevation surgery: review of 407 augmentation procedures. j oral maxillofac surg 2015; 73(7): 1275-82. 13. chirilă, lucian, . management of acute maxillary sinusitis after sinus bone grafting procedures with simultaneous dental implants placement–a retrospective study. bmc infect dis 2016; 16(1): 17. 14. sakkas, andreas, effect of schneiderian membrane perforation on sinus lift graft outcome using two different donor sites: a retrospective study of 105 maxillary sinus elevation procedures. gms interdisc plast reconstr surg dgpw 2016; 5 j bagh college dentistry vol. 30(4), december 2018 development of table 1: summery of the percentage, causes, and treatment of maxillary sinusitis after sinus lift surgery in the selected studies. treatment causes of sinusitis total n of membrane perforations diagnosis of sinusitis clinically and/or radiographically n of sinusitis and ratio type of bone substitute n of sinus augmentation types of sinus lift procedure n of patients year study sinusitis symptoms disappear after treatment with decongestants and antibiotics patients with a predisposition for this condition n: 29 only 1 case developed sinusitis *questionnaire *conventional radiographic examination *nasoendoscopy n:2 r:4.4% autogenous bone grafts 85 nm 45 1997 timmenga et.al (7) nm assumed long implant 10-16mm nm nm n:1 r: 2.5% organic bovine & autogenous bone nm lateral and crestal approach 40 2013 cannizzaro et al (8) nm nm n:52 no relation to postoperative complications nm n:6 r:4.7% nm 202 nm 127 2014 vazquez moreno et al (9) antibiotics sinus membrane perforation n: 150 17 of them developed sinusitis (11.3%) nm r: 12.7% nm 359 nm 208 2014 nolan et al (10) patients who had an intraoral fistula, the infected graft materials were removed from sinus cavity and they were placed on a 10-day course of clindamycin. *patients who suffer from chronic sinusitis * large amount of graft n: 8 no one developed sinusitis *questionnaire *satisfaction * radiographic examination, and nasal endoscopic 3 of the 4 patients presented with purulent exudative leakage from an intraoral fistula, and 1 patient had symptoms of mild acute sinusitis. n:4 r:4.2% cortico-cancellous mineralized allograft bone (145) 51 bilateral 43 unilateral lateral approach 94 2014 kayabasoglu et al(11) nm * sinus membrane perforation * smoking *sinus elevation width n: 35 11 of them developed sinusitis clinical symptoms and patient compliance n:34 r:8.4% a mixture of autologous bone and deproteinized bovine bone substitute (biooss) 407 lateral approach 300 2015 schwarz linda et al (12) removal of the graft material and implants. the sinus cavity was irrigated with metronidazole solution and an antibiotic therapy was prescribed for the patient which include clindamycin and metronidazole for 10 days patients developed infections received *xenografts (3 cases) *xenograft + allograft mix (1 case) *alloplastic grafts (1 case) nm “the clinical signs of infection: headache, locoregional pain, cacosmia, inflammation of the oral buccal mucosa and rhinorrhea or unilateral nasal discharge”. n:5 r:4.3% *xenograft *allograft *xenograft and allograft mix *alloplastic *xenograft and alloplastic mix 151 lateral window technique 116 2016 chirilă et al (13) antibiotics prescribed for the patients and the graft had to be removed. the patients were not treated with implants anymore sinusitis developed in patient with no membrane perforation and with no history of maxillary sinus diseases n: 11 no one developed sinusitis (clinical signs of infection) headache nasal congestion , pain on the operated facial site, fever or redness n:2 r:2.12% autogenous bone 501 lateral wall approach 99 2016 sakkas et al (14) abbreviations: n: number; nm: not mentioned; r: ratio. baydaa f.doc j bagh college dentistry vol. 25(4), december 2013 dissolution of inorganic pedodontics, orthodontics and preventive dentistry91 dissolution of inorganic phosphorous ion from human enamel treated with different concentration of siwak aqueous extract in comparison with sodium fluoride alhan ahmed qasim, b.d.s., m.sc. (1) nibal mohammad hoobi, b.d.s., m.sc. (1) baydaa hussein, b.d.s., m.sc. (2) abstract background: the use of miswak, chewing sticks (salvadorapersica) can be traced back to babylonians some 7000 years ago. it is commonly used throughout the world especially for the purpose of oral hygiene. muslims are using as the religious view. current study aimed to test the ability of aqueous siwak extract to increase the resistance of enamel surface against acid dissolution compared to sodium fluoride. materials and method: twenty maxillary first premolars were treated with the selected solutions included two aqueous siwak extract concentration(5%,10%) and sodium fluoride(0.05%)as control positive for 2 minutes once daily for 20days interval, de ionized water was used as control negative. the concentration of the dissolved phosphorus ion was measured in etching solution of 2n hcl by flam atomic absorption spectrometer. result: 10% aqueous siwak extract test solution was registered the lesser release of phosphorusion from etched enamel surface, then 5% aqueous siwak extract followed by sodium fluoride 0.05%. no significant difference between two aqueous siwak extract concentration, while a significant difference was found between mentioned agents and sodium fluoride. de ionized water was recorded a highly significant difference with all test solutions. conclusion: aqueous siwak extract effective in increasing the resistance of enamel surface for acid dissolution and should be use not only for the religious view but also for the benefit of its effects produced. key ward: aqueous siwak extract, acid etching, phosphorus dissolution. (j bagh coll dentistry 2013; 25(4):91-94). introduction salvador apersica (s.p.) is a plant that grows in the desearts of the area from west india to africa. the roots and sticks of s.p. are used widely for cleaning the teeth in these areas. the other names for this plant are arak tree, chewing stick, natural toothbrush and miswak or siwak (1). also miswak (salvadorapersica) is oneof the mostcommonly used medicinal plants for oral hygiene among global muslim community (2), and it's widely used as a chewing stick in many countries. the toothbrush tree, salvador apersica, locally called miswak, is a member of the salvadoraceae family has been used by many islamic communities as toothbrushes and has been scientifically proven to be very useful in the prevention of tooth decay, even when used without any other tooth cleaning methods(1) . as well as the beneficial effects of miswak in respect of oral hygiene and dental health are partially due to its mechanical action and partially due to pharmacologic action (antibacterial activity).(4) a study conductedon wood siwak and reports that it contains natural minerals that can kill and inhibit bacteria growth, eroded plaque, prevent cavities and gum care (5), this may attributed to its constituents as calcium, phosphorous, fluoride and other element (1) lecturer, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. may react with the outer enamel surface changing the resistance against caries challenge. at the same time other constituents as tri methylamine may have an antibacterial effects changing the microbial composition of the dental plaque, by this siwak may affect both dental caries and periodontal disease (6,7). other study revealed that the amount of phosphorous released from salvadorapersica stick soaked in water is 34μg/ml that represent 26.4% of the total content in the stick, while the amount of calcium release in water is 582μg/ml which represent 19.6% of the total content in the stick(8).for this reason recently these sticks were recommended as an effective tool for oral health by the world health organization (who).(9) so that the purpose of thisinvestigation was to test the effect of aqueous siwak extract in increasing of the enamel resistance against acid dissolution. materials and method the sample consisted of 20 teeth which is randomly selected of human maxillary first premolars extracted from (10-13) year old patients for orthodontic purpose. after cleaning of extracted teeth by using conventional hand pieceand rubber cup with non-fluoridated pumice and deionized water, then stored in 0.1% thymol solution at 4º c until use, to minimize brittleness of enamel and microbial growth (10). the preparing of siwak aqueous extract was done by taking 250 gm. of siwak powder and placed in a j bagh college dentistry vol. 25(4), december 2013 dissolution of inorganic pedodontics, orthodontics and preventive dentistry92 beaker to which de-ionized water was added till reach a volume of one liter, then the beaker was closed tightly and left to boil at 100c for 15 minute, then left to warm . the liquid was then filtered using filter paper (no.1), then this filtered aqueous extract was left to dry at 40c in incubator for 24 hours, to allow the evaporation of water and to obtain a powder of siwak extract . the powder was collected and kept in tightly closed glass container and kept in refrigerator until use (11). teeth were divided randomly into four equal groups, each group consisted of five teeth and then the teeth were immersed individually for two minutes once daily over twenty days in thirty ml of their assigned test solution which included, siwak water extract (5%, 10%) and sodium fluoride (0.05%) which is the approved concentration of daily homeusedsodium fluoride (12). de-ionized water group was used as a control negative. after each immersion, the specimens were water washed in deionized water for 5 minutes, then stored in humid condition of deionized water to which 0.1% thymol was added until the next immersion. after the twenty day treatment period, a circular area (3 mm in diameter) were selected on buccal surface of each enamel specimen by applying prepared annular adhesive disc, avoiding microscopic cracks and hypo plastic areas. the rest of specimen was covered with a sticky wax, leaving only the circular enamel window exposed for subsequent etching, then the windows were etched for ten seconds in separated polyethylene tubes, each containing five ml of 2nhcl. the concentration of released phosphorus ion was determined calorimetrically by the molybdenum – vanadate method. a ready-made kit (bio maghreb, tunisia) was supplied. inorganic phosphorus react with ammonium molybdate in the presence of sulphuric acid to form a phosphomolybdate complex. the color of molybdenum blue was proportional to the phosphorus concentration (13). the data was processed with spss version (9.0) statistical software. mean and standard deviation were calculated. anova (analysis of variance) and lsd (least significant difference) tests were used to evaluate the significance of difference between different groups. the significance level was accepted at 95% (p<0.05). results the mean values and standard deviation of release phosphorus ion concentration according todifferent concentration of siwak aqueous extract and sodium fluoride and statistical analysis using anova test wereshowed in table(1). the maximum mean value for dissolved phosphorus ion was recorded for deionized water group followed by sodium fluoride treated group, while the least dissolved phosphorus concentration was registered for siwak aqueous extract (10%) treated group. the difference in the phosphorus concentration was statistically highly significant among different test groups. the difference between each two groups was illustrated in table (2) using lsd test. it showed that there was no significant difference between the two siwak aqueous extract concentration (5% and 10%). concerning sodium fluoride group (0.05%), a significant difference was recorded with siwak aqueous extract (5%), while non-significant difference with other siwak water extract concentration (10%). on other hand the deionized water immersed group statically showed highly significant difference with all tested solutions. discussion the traditional toothbrush or chewing stick is deeply rooted in islamic culture.it's apencil-sized sticks of various plants are fashioned from certain plant parts and are chewed on one end until they become frayed into a brush.so that the brush-end is used to clean the teeth in a manner similar to the use oftoothbrush. when used in this manner, they are commonly referred to as chewingsticks or miswak (2,14). these sticks have been shown to havea therapeuticeffect on the gingiva and surroundingstructures in addition to their mechanical effect (4,15). many studies were revealed that the aqueous extract of siwak had antimicrobial effect at different concentration (6,7,16), also salvadorapersica miswak contains nearly 1.0μg/g of total fluoride and was found to release significant amounts of calcium andphosphorus into water and these act as anticariognic agent that may react chemically to the outer surface of enamel(17,18). in this studyaqueous extract of siwak (salvadorapersica) was used to test its ability in different concentration (5%, 10%) to decrease the loss of phosphorus ions from enamel of teeth which immersed in 2n hcl (to increase enamel hardness) in comparison to sodium fluoride. this fluoridated agent was used as control positive because of their documented re mineralizing potential effect of enamel which increases its resistance to caries (19-21), while de-ionized water was used as a control negative. aqueous siwak extract was selected in this experiment rather than other types of siwak extract (chloroform and ethanol siwak extract) due to the uniform solvent of the used agent. sticks of siwak were powdered, j bagh college dentistry vol. 25(4), december 2013 dissolution of inorganic pedodontics, orthodontics and preventive dentistry93 and then aqueous extract was prepared following al-jeboory technique (11). as well as many iraqi studies used the aqueous extract of siwak due to the easily way for preparing and more effective than other extract types (7,22). enamel consists of approximately 97% inorganic minerals. calcium and phosphorus (as hydroxyapatite) are the main building block of dental hard tissues. changes in the calcium/phosphate ratio indicate alterations in the inorganic components of hydroxyapatite (23,24). in this study the enamel was treated withdifferent percent of aqueous water extract(5% , 10%) and sodium fluoride 0.05% was used due to its stability, well test, not irritant to the gingiva and not cause discoloration of tooth structure (25),therefore it was used as control positive in this test. the concentration release of phosphorus ion after etching with acid following treatment of enamel samples with test solutionswashigher for deionized water than the selected solutions with highly significant difference. this may be due to incorporation of ions which increase an enamel micro hardness and decrease its porosity against acid demineralization. while the lowest release of phosphorus was found in siwak aqueous extract (10%) followed by (5%) this may related to chemical composition of siwak as it content ofanti-cariogenic agents as calcium and phosphorus ions which are the main components of hydroxyapatite crystal, in addition to the large amounts of fluoride present in siwak (17 )may be a contributing factor to this effect (8,26). as these ions incorporated in the outer enamel layer increase the microhardness and may explain why this difference found between the concentration of dissolved phosphorus ion in aqueous siwak extract and de-ionized water. application of fluoride on the tooth surface directly as a topical agent(sodium fluoride) will react with the hydroxyapatite crystals to form fluoroapatite crystal which in turn makes the enamel surface more resistance to acid dissolution (22,26), this may explain the lower concentration of phosphorus ion released from teeth treated with sodium fluoride agent than that of de-ionized water, while this release of phosphorus ion was higher than that in aqueous siwak extract (5%,10%) with significant difference,which may be due to the combination of cariostatic ions in siwak (17). the increase in the concentration of aqueous siwak extract result in an increase in these cariostatic ions, which lead to increase in calcium / phosphorus (ca/p) ratio in the enamel surface thus increase its resistance to acid challenge, in addition to the increase of fluoride concentration in tooth surface made the enamel harder (24,27), this will explain the dissolution of phosphorus ions from acid etched teeth immersed with 10% aqueous siwak extract was less than that treated in 5% aqueous extract of siwak with non-significant difference. based on results of this study, the conclusion is that the uses of siwak (salvadorapersica) in different concentration decrease the dissolution of main ion(phosphorus) from enamel surface when comparing with other test solution , there is no clear idea about the type of reaction took with enamel surface, which at the end lead to decrease the dissolution of phosphorus ion from tooth surface, it may be attributed to a number of chemicals isolated from salvadorapersica plants (siwak) like the calcium , phosphorus and fluoride content (17) helps to increase the mineralization of porous enamel surface of the teeth, thus decreasing the dissolution of phosphorus ions from tooth surface. the result of this study showed higher efficacy of 10% miswak extract in reduction the release of phosphorus ions as compared to other test solution. since miswak is inexpensive, readily available, contains medicinal properties, and is available in most rural areas of the developing countries, so it can be an effective tool in preventing oral diseases. in this regard, further evaluation studies needs to be carried out on salvadorapersica plant in order to explore the concealed areas and their practical clinical applications, which can be used for the welfare of the mankind. references 1. abdel-wahab s, selim m, el-fiki n. investigation of theflavonoid content of salvadorapersica l. bull fac pharm cairo univ 1990; 28: 67–70. 2. sher h, al yemeni mn, yahya sm, arif hs. ethnomedicinal and ethnoecological evalution of salvadorapersica l: a threatened medicinal plant in arabian peninsula. j med plants res 2010; 4(12):1209-15. 3. al-bayati fa, sulaiman kd. in vitro antimicrobial activity of salvadorapersica l. extracts against some isolated oral pathogens in iraq. turk j biol 2008; 32: 57-62. 4. zaenab-mardistuti mw-vp, anny bl. antibacterial siwak (salvadorapersica linn.) terhadop streptococcus mutans (act 31987) dan bacteriodes melaninogenicus. makara serikesehaton 2004; 8(2): 37-40. (ivsl). 5. akpata es, akinrimisi e. antibacterial activity of extracts from some african chewing sticks. oral surgery 1977; 44(5): 717-22. 6. almas k. the antimicrobial effects of extracts of azadirachtaindica (neem) and salvadorapersica (arak) chewing sticks. indian j dent research 1999; 10(1): 23-6. 7. al-nidawi a. effect of siwak extracts on mutans streptococci in comparison to selected antimicrobial agents. a master thesis, college of dentistry/ university of baghdad, 2004. j bagh college dentistry vol. 25(4), december 2013 dissolution of inorganic pedodontics, orthodontics and preventive dentistry94 8. hattab fn. miswak, the natural tooth brush. j clin dent 1997; 8: 125-9 9. world health organization (who). consensus statement on oral hygiene. int dent j 2000; 50:139. 10. barbakow f, sener b, snr lab tech, lutz f. dissolution of phosphorus from human enamel pretreated in vitro using snf2 stabilized with amine fluoride. clin prev dent 1987; 9(5): 3-6. 11. al-jeboory a. ethnopharmacology. baghdad: alhauria house press; 1994. p.p 74-83. 12. featherstone jd. prevention and reversal of dental caries role of low level fluoride. community dental epidimiol 1999; 27:31-40. 13. rao a. trace elements estimation, methods and clinical context. online j health allies sci 2005; 4(1):65-75. 14. al sadhan ri, almas k. miswak (chewing stick): a cultural and scientific heritage. saudi dent j 1999; 11(2):80-8. 15. marco ab, rinaldo as, jose gm,cintia oc, mable cp, clandino a, ronaldo sr, dinalva bq, wagner sr, gloria m, francisca ir .efficacy of a mouth rinse based on leaves of the neem tree (azadirachtaindica) in the treatment of patients with chronic gingivitis: a double-blind, randomized, controlled trial. . j medicinal plant research 2008; 2(1):341-6. 16. al-lafi t, ababneh h. the effect of extract of miswak used in jordan and the middle east on oral bacteria. int dent j 1995; 45(3): 218 – 22. 17. char d, dogao a, dogon m. sem, xrf, and empa evalution of middle eastern tooth brush ''salvadorapersica". j elec micro tech 1987; 5:145. 18. darout ja, christy aa, skaug n, egeberg pk. identification and quantification of some potentially antimicrobial anionic components in miswak extract. indian j pharmacol 2000; 32: 11-4. 19. al-anni m. effect of selected metal salts on the microhardness and microscopic feature of initial carious lesion of permanent teeth. a master thesis, college of dentistry, university of baghdad, 2005. 20. seppal. effect of sodium fluoride solution and with different fluoride and a varnish concentration on enamel remineralization in vitro. scand j dent res 1988; 96(4): 304-8. 21. milberg jr. evaluation oftopical fluoride preparations. j dent res 1990; 69: 771-9 22. obaidy nm, el-samarrai sk, majeed ah. effect of siwak extract on the micro hardness and microscopic feather of initial caries-like lesion of permanent teeth compared to fluoridated agents. mdj 2008;5(4):36572. 23. santini a, colin r, rajab pa, ibbetson r. the effect of 10% carbamide peroxide bleaching agent of tooth enamel assessed by roman spectroscopy. dent traumatol 2008; 24: 220-3. 24. legerosrs. calcium phosphates in restorative dentistry. adv dent res 1988; 2(1):164-80. 25. peter s. essentials of preventive and community dentistry 2nd ed. new delhi: arya publishing house. darya ganj; 2004. pp. 249. 26. ezodini-ardakani f. efficacy of miswak (salvadorapersica) in preventing dental caries. health 2010; 2(5): 499-503. 27. hassan sh. a review on miswak (salvadorapersica) and its effect on various aspect of oral health. saudi dent j 2012; 24: 63-9. table 1: concentration of phosphorus ion (mean, standard deviation and statistical analysis anova) dissolved in hcl from enamel treated with selected agents p-value f-value ±sd mean no. test solution 0.000** 107.317 0.026 0.46 5 aqueous siwak extract 10% 0.047 0.38 5 aqueous siwak extract 5% 0.068 0.69 5 sodium fluoride 0.381 2.30 5 de-ionized water ** highly significant (p<0.01) table 2: least significant difference (lsd) between each two agents. p-value mean difference agent 2 agent 1 0.526 0.081 0.000** 0.80 -0.23 -1.84 aqueoussiwak extract 5% sodium fluoride deionized water aqueous siwak extract 10% 0.526 0.023* 0.000** -0.08 -0.31 -1.92 aqueous siwak extract 10% sodium fluoride deionized water aqueous siwak extract 5% 0.081 0.023* 0.000** 0.23 0.31 -1.61 aqueous siwak extract 10% aqueous siwak extract 5% deionized water sodium fluoride 0.000** 0.000** 0.000** 1.84 1.92 1.61 aqueous siwak extract 10% aqueous siwak extract 5%sodium fluoride deionized water * significant (p<0.05), **highly significant (p<0.01) j bagh college dentistry vol. 26(1), march 2014 genders identification orthodontics, pedodontics and preventive dentistry 150 genders identification using mandibular canines (iraqi study) haider mohammed ali ahmed, b.d.s., m.sc. (1) abstract background: this study aimed to determine the gender of a sample of iraqi adults using the mesio-distal width of mandibular canines, inter-canine width and standard mandibular canine index, and to determine the percentage of dimorphism as an aid in forensic dentistry. materials and methods: the sample included 200 sets of study models belong to 200 subjects (100 males and 100 females) with an age ranged between 17-23 years. the mesio-distal crown dimension was measured manually, from the contact points for the mandibular canines (both sides), in addition to the inter-canine width using digital vernier. descriptive statistics were obtained for the measurements for both genders; paired sample t-test was used to evaluate the side difference of mandibular canines in both genders, independent samples t-test was performed to evaluate the gender difference in addition to the percentage of dimorphism and percentages of correctly classified and misclassified cases using the standard mandibular canine index. results: the mesio-distal widths of the mandibular canines were non-significantly slightly larger in males than females, while the inter-canine width was larger in males than females with a high significant difference. the accuracy of genders determination using standard mandibular canine index was 32% for males, 59% for females and 45.5% for the combined sample. the percentages of dimorphism were 0.58% for the canine mesio-distal width, 3.99% for the intercanine width and 3.85 for the mandibular canine index. conclusions: the mandibular inter-canine width and mandibular canine index gave better percentage of dimorphism than the mesio-distal width of mandibular canines. on the other hand, standard mandibular canine index showed low accuracy for gender determination. keywords: canine width, inter-canine width, standard mandibular canine index, forensic dentistry. (j bagh coll dentistry 2014; 26(1):150-153). introduction teeth, in the living as well as the dead, are the most useful objects in the field of forensic investigation. their ability to survive in situations like mass disasters makes them important tools in victim identification. though the morphology and structure is similar in both men and women, there are subtle differences. variation in dental size can give a clue about differences between the sexes (1). canines are perhaps the most stable teeth in the oral cavity because of the labio-lingual thickness of the crown and the root anchorage in the alveolar process of the jaws. the crown portions of the canines are shaped in such a manner as to promote cleanliness. this selfcleansing quality and efficient anchorage in the jaws tend to preserve these teeth throughout life (2). these findings indicate that canines can be considered the ‘key teeth’ for personal identification (3). regarding the forensic dentistry, the mandibular canine widths and inter-canine width and the ratio between them (mandibular canine index) alone or in combination were used in many studies (3-11). in iraq, genders identification was studied using the radiographs (12,13) and the c.t. scan (14) or with the aid of study models (15-17). this study is the first in iraq that determine the genders using the mandibular canines. (1)assistant lecturer. department of orthodontics. college of dentistry, university of baghdad. materials and methods sample the study sample consisted of 200 sets of study models belong to 100 males and 100 females selected from the students of the college of dentistry, university of baghdad and some secondary schools based on the following criteria: 1. the age ranged between 17-23 years. 2. all of the subjects had complete set of fully erupted teeth regardless the wisdom teeth. 3. the mandibular anterior teeth were intact, caries-free, well aligned with no signs of attrition, mobility or gum recession and no history of orthodontic treatment. methods after the clinical examination of all subjects, dental impressions for the maxillary and mandibular arches were taken with alginate impression materials. a study models were constructed after pouring the impressions with dental stone. the maximum mesio-distal crown widths of mandibular canines were measured from the anatomical contact points (18) using digital sliding caliper gauge with the pointed beaks inserted in a plane parallel to the long axis of the tooth. the measurements were made to the nearest 0.01 mm. the inter-canine width or distance was measured from the canine tip to the canine tip on the other side with same caliper gauge (4). mandibular canine index (mci) was first measured by rao et al. (4) and calculated by j bagh college dentistry vol. 26(1), march 2014 genders identification orthodontics, pedodontics and preventive dentistry 151 dividing the mesio-distal width of the mandibular canine by the inter-canine distance. based on these values, the standard mci was derived as follows (4): standard mci = (mean males mci sd) + (mean females mci + sd) 2 statistical analyses all the data of the sample were subjected to a computerized analysis using spss program version 19. the statistical analyses included:  descriptive statistics: means, standard deviations, frequency, percentages and statistical tables.  inferential statistics: paired sample t-test to evaluate the side difference in the width of canines in both genders. independent sample ttest to evaluate the genders difference. percentage of dimorphism which is the percentage by which the tooth size of males exceeds that of females {it equals to = [(xm/xf)-1x100] where xm is the mean tooth dimension of males and xf is the mean tooth dimension of females} (19). in the statistical evaluation, the following levels of significance were used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results table 1 demonstrated the difference between the right and left mandibular canine widths in both genders. the results showed non-significant side difference. table 1. descriptive statistics, sides’ differences of the width of mandibular canines (mm.) genders side descriptive statistics side difference mean s.d. t-test p-value males right 6.90 0.44 -1.04 0.301 (ns) left 6.93 0.46 females right 6.88 0.62 -0.42 0.678 (ns) left 6.89 0.57 table 2 showed the genders differences regarding the canines’ widths, inter-canine width and mandibular canine index. generally, there was non-significant gender difference regarding the widths of the canines, but there was significant gender difference in inter-canine width and mandibular canine index. the percentages of dimorphism were high in inter-canine width and mandibular canine index in accordance with the gender difference. table 2. descriptive statistics, genders’ differences and percentage of dimorphism for the measured variables (mm.) variables genders descriptive statistics genders difference percentage of dimorphism mean s.d. t-test p-value right canine (rc) males 6.90 0.44 0.355 0.723 (ns) 0.29 females 6.88 0.62 left canine (lc) males 6.93 0.46 0.579 0.563 (ns) 0.58 females 6.89 0.57 mean of both canines males 6.92 0.43 0.474 0.636 (ns) 0.58 females 6.88 0.58 inter-canine width (icw) males 27.61 2.25 3.309 0.001 (hs) 3.99 females 26.55 2.30 mandibular canine index (mci) males 0.252 0.02 -2.45 0.015 (s) 3.85 females 0.261 0.03 table 3 demonstrated the frequencies and percentages of correctly classified and misclassified cases using the standard mci. the value of this index was 0.26 after calculation from the equation above. generally, females showed good percentage in genders identification than males. j bagh college dentistry vol. 26(1), march 2014 genders identification orthodontics, pedodontics and preventive dentistry 152 table 3. frequencies and percentages of correctly and misclassified cases using standard mandibular canine index genders frequencies and percentages of correctly classified cases frequencies and percentages of misclassified cases males 32 (32%) 68 (68%) females 59 (59%) 41 (41%) total 91 (45.5%) 109 (54.5%) discussion in this study, mandibular canines were chosen because hashim and murshid (20) found that the canines were the only teeth that exhibit dimorphism. subjects with age ranged from 17 to 23 years were selected since attrition is minimal in this age group and the eruption of canines and growth in width of both the jaws, including the width of the dental arches, are completed (21). the results showed non-significant side difference between the right and left canines (table 1); this comes in agreement with many studies (5-11). this means that any measurement of mandibular canine on one side could be truly representative when the corresponding measurement on the other side was unobtainable (22). the findings in the present study showed that the males had slight larger canine widths with a non-significant difference (table 2). this agrees with boaz and gupta (7) and disagrees with the other studies (5,6,8-11) that found significant gender difference in mandibular canines widths. this may be attributed to the sample size or the difference in the ethnic groups. the mean canine width was non-significantly higher in males than females (table 2); this comes in accordance with hosmani et al. (11). in the present study, males have higher intercanine width than females with a high significant difference (table 2). this comes in agreement with many studies (5,6,8,9) while disagrees with vishwakarma and guha (10) and hosmani et al. (11). regarding the mandibular canine index (mci), this index was higher significantly in females (table 2). previous studies (5,6,8,9) showed significantly higher mci in males. vishwakarma and guha (10) and hosmani et al. (11) revealed nonsignificant gender difference. the percentage of dimorphism (table 2) was very low for the width of the mandibular canines. this is normal result due to slight width difference. this finding disagrees with other findings (1,3,10). on the other hand, the inter-canine width and mci showed marked dimorphism in comparison with the canine widths. the frequencies and percentages of correctly classified and misclassified cases using the standard mandibular canine index were presented in table 3. the value of this index was 0.26. value of mandibular canine index above 0.26 was classified as male and equal to and less than 0.26 was classified as female. in this study, the percentages of gender identification accuracy using standard mandibular canine index were 32% for males, 59% for females and 45.5% for the combined sample. these percentages are near to that of srivastava (8) and hosmani et al. (11) who could not yield high level of gender determination accuracy. the probable reason for low accuracy could be due to the evolutionary changes, the genetic factors or the ethnic background. references 1. bakkannavar sm, monteiro fnp, arun m, kumar gp. mesiodistal width of canines: a tool for sex determination. med sci law 2012; 52(1): 22–6. 2. ash mm, nelson sj. wheeler’s dental anatomy, physiology and occlusion. 8th ed. saunders elsevier: thomson press (india) ltd.; 2004. 3. kaushal s, patnaik vvg, agnihotri g. mandibular canines in sex determination. j anat soc india 2003; 52(2):119–24. 4. rao ng, rao nn, pai ml, kotian ms. mandibular canine index--a clue for establishing sex identity. forensic sci int 1989; 42(3): 249-54. 5. al-rifaiy mq, abdullah ma, ashraf i, khan n. dimorphism of mandibular and maxillary canine teeth in establishing sex identity. saudi dent j 1997; 9(1):17–20. (ivsl). 6. kalia s. a study of permanent maxillary and mandibular canines and inter-canine arch widths among males and females. a master thesis. department of oral medicine and radiology, rajiv gandhi university of health sciences, karnataka, bangalore, 2006. 7. boaz k, gupta c. dimorphism in human maxillary and mandibular canines in establishment of gender. j forensic dental sci 2009; 1(1): 42-4. (ivsl). 8. srivastava pc. correlation of odontometric measures in sex determination. j indian acad forensic med 2010; 32(1): 56-61. 9. magar sp, wanjari pv, phulambrikar t, mosby sp, magar ss. dimorphism of mandibular canine index establishing in sex identity. j indian academy oral med radiol 2011; 23(3): 195-8. 10. vishwakarma n, guha r. a study of sexual dimorphism in permanent mandibular canines and its implications in forensic investigations. nepal med coll j 2011; 13(2): 96-9. 11. hosmani jv, nayak rs, kotrashetti vs, pradeep s, babji d. reliability of mandibular canines as http://www.ncbi.nlm.nih.gov/pubmed?term=rao%20ng%5bauthor%5d&cauthor=true&cauthor_uid=2792982 http://www.ncbi.nlm.nih.gov/pubmed?term=rao%20nn%5bauthor%5d&cauthor=true&cauthor_uid=2792982 http://www.ncbi.nlm.nih.gov/pubmed?term=pai%20ml%5bauthor%5d&cauthor=true&cauthor_uid=2792982 http://www.ncbi.nlm.nih.gov/pubmed?term=kotian%20ms%5bauthor%5d&cauthor=true&cauthor_uid=2792982 j bagh college dentistry vol. 26(1), march 2014 genders identification orthodontics, pedodontics and preventive dentistry 153 indicators for sexual dichotomy. j int oral health 2013; 5(1):1-7. 12. rashid sa, ali j. sex determination using linear measurements related to the mental and mandibular foramina vertical positions on digital panoramic images. j bagh coll dentistry 2011; 23(special issue): 59-64. 13. ali ar, al-nakib lh. the value of lateral cephalometric image in sex identification. j bagh coll dentistry 2013; 25(2): 54-8. 14. taha ua, al-nakib lh. craniometric asymmetry assessment in class i and class ii skeletal relationship patients using helical computed tomography sample aged between 18-35 years. j bagh coll dentistry 2013; 25(4): 60-5. 15. al-fahdawi ih. identification of sex groups in forensic medicine according to the mesiodistal crown diameter of teeth. alanbar medical j 2011; 9(1): 103-9. 16. nahidh m, ahmed hma, mahmoud ab, murad sm, mehdi bs. the role of maxillary canines in forensic odontology. j bagh coll dentistry 2013; 25(4): 10913. 17. nahidh m. the value of maxillary central incisors and canines in gender determination as an aid in forensic dentistry. iraqi dental j 2014 (accepted for publication). 18. hunter ws, priest wr. errors and discrepancies in measurement of tooth size. j dent res 1960; 39(2): 405-14. 19. garn sm, lewis ab, kerewsky rs. bucco-lingual size asymmetry and its developmental meaning. angle orthod 1967; 37(3): 186-93. (ivsl). 20. hashim ma, murshid za. mesiodistal tooth width: a comparison between saudi males and females, part 1. egypt dent j 1993; 39(1): 343-6. 21. proffit wr, fields hw jr, sarver dm, ackerman jl. contemporary orthodontics. 5th ed. st. louis: elsevier mosby; 2013. 22. hashim ma, murshid za. mesiodistal tooth width in a saudi population sample comparing right and left side: part 2. egypt dent j 1993; 39(1): 347-50. dropbox 14 muna 76-81.pdf simplify your life 6.mustafa f.doc j bagh college dentistry vol. 25(1), march 2013 assessment of some restorative dentistry 34 assessment of some mechanical properties of imprelon® and duran® thermoplastic biostar machine sheets in comparison with some types of acrylic resins mustafa f. mohammed, b.d.s. (1) salah a. mohammad, b.d.s., m.s.d. (2) abstract background: imprelon® biostar foils are new alternative tray material that has become increasingly popular because oftheir several advantages. also, (duran®) is another type of biostar foils which is used in splint therapy. this study assessed some mechanical properties of these two types biostar sheets in comparison with some types of acrylic resins used for construction of trays and splints. materials and methods: a total of 150 specimens were prepared, 30 specimens for each test, 10 for each group material in order to assess some mechanical properties of the imprelon® biostar foil (dimension stability, surface roughness and shear bond strength of imprelon® materialto zinc oxide impression material) and compare them to that of the other tray materials (autopolymerized and vlc) resin materials. also to assess the mechanical properties (wear rate and transverse strength) of the duran® biostar foil and compared them with that of the other splints materials (heat-cure acrylic and vlc) resins. results:the results showed highly significant differences at p<0.01 between all studied groups except the in dimensional changes of imprelon® and vlc, and in wear rate of heat cure acrylic and vlc resins, no significant differences obtained between their studied groups. conclusions: imprelon® is dimensionally stable, so it can be used directly after fabrication, also it has a good shear bond to zinc oxide eugenol impression material but it may not provide mechanical retention to other elastomeric impression materials and their adhesives since it has a low value of surface roughness (ra).duran® is recommended for short time use in patients with acute pain and/or dysfunction symptoms. keywords: imprelon® biostar foils, duran® biostar foils, acrylic resins, mechanical properties. (j bagh coll dentistry 2013; 25(1):34-37). introduction accurate registration of oral structures requires an accurate impression material, an accurate impression tray to support the material and a means of bonding or attaching the set material to the tray (1). (imprelon®) is a thermoplastic material made from polystyrol (ps) used temporarily in mouth as a special tray, as a substitution to the cold cure acrylic trays or light cure acrylic. while (duran®) is another hard-elastic, abrasion resistant, unbreakable material used for all indications in the splint therapy as a substitution to the heat cure acrylic (2), a bite splint is a removable appliance, usually fabricated of acrylic or composite, most often designed to cover all the occlusal and incisal surfaces of the teeth in the upper or lower jaw most splints are now made using heat-cured acrylic, splints can also be made from soft acrylic or using light cured composite(3,4). the molding of these two materials can be achieved with positive pressure molding machine which is called “biostar”machine. (1)m.sc. student, department of prosthodontics, college of dentistry, university of baghdad. (2)assistant professor, department of prosthodontics, college of dentistry, university of baghdad. materials and methods five different materials were used in this study: (heat cure acrylic resin, cold cure acrylic resin, light cure acrylic resin, imprelon and duran biostar sheets). these different resin materials have different curing methods; they were grouped and used to evaluate, dimensional stability, shear bond strength to the zinc oxide eugenol impression material, surface roughness, transverse strength, wear rate.a total of 150 specimens were prepared, 30 specimens for each test, 10 for each material. surface roughness: a stainless steel mould was prepared for this test, it consist of two parts (plate and frame), the frame of 6mm height and the plate of 3mm thickness and 15*10mm dimensions, figure (1). the profilometer device was used to study microgeometry of the tested surfaces. it is supplied with surface analyzer (stylus) made from diamond to trace the profile of surface irregularities, and recording all the peaks and recess which characterize the surface. shear bond strength: two metal pattern were constructed with dimensions of (76.2 mm* 12.7mm *4.76mm length, width and depth respectively) with stopper of 3 mm thickness to provide space, and handle thickness of (13mm) figure (2), these metal pattern were used to prepared 30 specimens for shear bond strength. the zinc oxide impression material has been j bagh college dentistry vol. 25(1), march 2013 assessment of some restorative dentistry 35 applied by spatula into space between the blocks and any excess of material was removed using sharp knife, then the specimen was put under weight of 200g (5)for stability and left it for 4-5 minutes at room temperature (25±2c˚) for bench cure. after setting of the impression material the specimens were tested for shear bond strength by instron testing machine. dimensional stability: the same stainless steel mould of surface roughness test was used for this test with the same dimensions, but the metal frame had marked with four grooves about 2 mm away from their borders, in order to mark four (+) signs about 2 mm away from the corners. these signs after preparation would be good defined marks for measurements. a computerized scanning to the specimens was done in two stages: first one directly after separation from the metal mould and the second one after 24 hours (leaving the specimens on the bench at room temperature for 24 hours to resemble the same circumstances of the use of the custom trays). a computerized program (dino capture) was used to measure the distances between the corners of the selected marks (+). transverse strength: thirty specimens were prepared; ten specimens for each group or material (i.e. duran®, heat-cure acrylic and vlc), each specimenhad a dimension of (65*10*3 mm) ±0.3mm length, width and height respectively according to ansi/ada no.12. the transverse strength of samples was measured by using three points bending test in an instrun machine. wear rate: thirty specimens were prepared; ten specimens for each group or material (i.e. duran®, heat-cure acrylic and vlc), each specimenhave a circular shape and dimension of (65*3 mm) ±0.5mm diameter and thickness respectively according to the requirement of the test. the testing machine consisted of pin holder in which the stylus has be enfixed, the pin holder has connected to the horizontal metal arm, aluminum rotary disc of (500 rpm), normal load of (1500g), figure (3), aluminum oxide smoothing paper and electronic balance of accuracy 0.0001g was used to accomplished the test, the measurement of the wear rate was done by a (weighting method), since it is a simple method and easy to be applied. data were translated into computerized database structure. statistical analysis was done by using spss version 16(statistical package for social science). figure 1: metal mold for surface roughness test figure 2: mettal pattern for shear bond test figure 3: wear rate testing machine results table 1 showed the results of multiple comparisons by lsd (least significant difference)method which were represented statistically differences at p<0.01 between study shear test at p<0.01 between cold c.a. group and the leftover groups as well as a highly significant different at p<0.01 between vlc group and imprelon® group. with respect to surface roughness parameter, the comparisons between the studied groups showed that highly significant results were reported with the all comparisons. finally, with respect to dimensional changes, the significant comparisons between the studied groups showed that a highly significant were reported with the all comparisons except between vlc and imprelon® groups which was reported a non-significant different at p>0.05.table (2) showed the results of multiple j bagh college dentistry vol. 25(1), march 2013 assessment of some restorative dentistry 36 comparisons by lsd method which represented statistically differences with the parameter of transverse strength test at p<0.01 between hot c.a. group and the leftover groups as well as a highly significant different at p<0.01 between vlc group and duran® group. with respect of wear rate parameter, the comparisons between the studied groups showed that a non-significant at p>0.05 was registered between hot c.a. group and vlc group, while a highly significant were reported with the leftover comparisons. the vlc showed the highest mean value of surface roughness(6.382µm) followed by autopolymerized acrylic resin, while the imprelon® had the lowest mean value of surface roughness. the imprelon® showed the highest mean value of dimensional stability (0.032mm), followed by vlc, while the autopolymerized acrylic resin was dimensionally unstable. table 1: multiple comparison (lsd) among all pairs of (shear bond strength, dimensional changes and surface roughness) parameters according to different treated groups (i) model (ii) model sig. levels (p-value) (*) shear bond s. surfac e r. dimensio nal changes cold c.a. vlc 0.000 0.000 0.000 imprelon® 0.000 0.000 0.000 vlc imprelon® 0.000 0.000 0.928 table 2: multiple comparison (lsd) among all pairs of ( transverse strength and wear rate) parameter according to different treated groups groups material test of homogeneity of variances anova equality of means c. s. (*) pval ue levene statistic sig. f sig. transve rse s. 4.584 0.019 352.7 4 0.00 0 h s wear r. 20.927 0.000 448.66 0.00 0 h s the imprelon® had the highest value of shear bond strength to the zinc oxide impression material (0.244n/mm2) vlc followed the imprelon® then autopolymerized acrylic resin when used as custom tray (table 3). the duran® showed the highest mean value of transverse strength(160.35n/mm2) followed by heat-cure acrylic then vlc resins, also the duran® showed the highest value of wear rate(0.00510 gr/mm) (table 4). table 3: descriptive statistics for shear bond, surface roughness and dimensional changes tests in the different of the studied treatment's groups: groups statistics surface r. µm d. change s mm shear b.s. n/mm 2 cold. c.a mean 3.188 0.214 0.142 std. deviation 0.467 0.025 0.012 vlc mean 6.382 0.033 0.182 std. deviation 0.600 0.005 0.014 imprelo n mean 0.023 0.032 0.244 std. deviation 0.005 0.006 0.027 table 4: descriptive statistics for strength and wear tests in the different of the studied treatment's groups: groups statistics transverse s. n/mm2 wear r. gr/mm hot. c.a mean 73.26 0.00008 std. deviation 7.97 0.00001 vlc mean 57.77 0.00004 std. deviation 5.19 0.00001 duran® mean 160.35 0.00510 std. deviation 13.02 0.00075 discussion surface roughness: the low value of (ra) of imprelon® might because of the already smooth surface of the imprelon® foil which processed under high temperature and high pressure; also it might due to small particle size of polystyrol.the vlc has showed surface roughness greater than cold-cure acrylic resin, the presence of impurities within vlc structure might contribute to this value ra (6). finally this might be due to different size particles of the vlc material components(7). dimensional stability: imprelon®has showed highest value of dimensional stability(after 24 hours on bench side) followed by vlc then cold-cure resin, this can be attributed to that the imprelon®is thermoplastic material this was in agreement with (8) who stated that an ideal plastic would be one that had no polymerization shrinkage. the autopolymerizing acrylic resin j bagh college dentistry vol. 25(1), march 2013 assessment of some restorative dentistry 37 showed the highest value of dimensional changes after 24 hours on bench side and this might be due incomplete polymerization of the acrylic resin since the polymerization process lead to shrinkage of the resin (9). shear bond strength: the imprelon®has showed highest bond strength with zinc oxide impression material, this exceptional increase in ultimate bond strength can be attributed to acetic acid, which is one of the accelerator additives of zinc oxide eugenol impression material, the acetic acid is organic solvents, weak acid, of chemical formula ch3co2h, and would dissolve polymers within its solubility parameter range (10). the second bond strength value to zinc oxide eugenol impression material was recorded by vlc followed by self-cur acrylic resin. this might because the difference in surface roughness value of these two materials, (the vlc showed highest value of ra6.382µm). transverse strength: the duran® has showed the highest value of transverse strength followed by heat-cure acrylic and the vlc acrylic resins, and this might be due to the modification of the poly (ethylene terephthalate) which is the main component of the duran by glycol, which lead to improvement of mechanical properties(11). also the differences of transverse strength values between the vlc and heat-cure acrylic can be attributed to different size particles of the vlc components(7) which might had a direct effect on the flexural strength of the material. wear rate: the duran® has showed highest wear rate followed by the other two types of acrylic resins; the vlc and heat-cure acrylic resin, which showed no significant difference between their wear rate as showed in table 6. the explanation of this might be due that the colorless polyethylene terephthalate pet (the main component of duran®) is semi-crystalline resin, and has a very lightweight (density)when compared with other two types of acrylic resins, also the particles size of pet-g is very fine (particle size < 500 nm). references 1. abdullah ma, talic yf. the effect of custom tray material type and fabrication technique on tensile bond strength of impression material adhesive systems. j oral rehab 2003; 30: 312-17. 2. scheu-dental gmbh (www.scheu-dental.com) amburgberg. 3. ash mjr. current concepts in the etiology, diagnosis and treatment of tmj and muscle dysfunction. j oral rehabil1986; 13: 1-20. 4. boero rp. the physiology of splint therapy: a literature review. angle orthod 1989; 59: 165-80. 5. yousif aa. the effect of disinfection, tray perforation and adhesive usage on the tensile and shear bond strength using two different elastomeric impression materials, (comparative study). a master thesis, prosthetic department, university of baghdad, 2006. 6. jin c, nikawa h, makihira s, hamada t, furukawa m, murata h. changes in surface roughness and color stability of soft denture lining materials caused by denture cleaners. j oral rehabil 2003; 30,125-30. 7. martin rj, johnson jf, cooper ar. mechanical properties of polymers; the influence of molecular weight and molecular weight distribution. 1973; 9: 57-200. 8. powers jm. mechanical properties. in: craig’s restorative dental materials, 12th ed. philadelphia, 2006:51–91. 9. philips rw. skinner’s science of dental materials, chapter11: denture base resins: technical considerations, miscellaneous resins and techniques, philadelpphia, pa, saunders, 1991: p207. 10. iqbal m z, mamoor gm, tariq b, irfan m, manzoor mb. a study on polystyrene-metal powder conductive composites. j chemical engin ieb 2010; 25 (1). 11. emco industrial plastic: (poly ethlene terephtalate glycol), 2012.www.emcoplastics.com http://www.scheu-dental.com http://www.emcoplastics.com hanan final.doc j bagh college dentistry vol. 26(3), september 2014 validity of computed oral diagnosis 63 validity of computed tomographic in assessment of genial tubercle and anterior mandible as a reference guide to locate osteotomy in genioglossus advancement hanan j. kadem, b.d.s. (1) ahlam a. fatah, b.d.s., m.sc. (2) abstract background: genioglossus advancement is a surgical procedure to advance the tongue in some patients with obstructive sleep apnea syndrome.the important step in this procedure is that of accurately capturing the bone segment attached to the genioglossus muscle to avoid complications such as mandibular fracture, devitalization of the inferior incisor roots, and incomplete incorporation of the genioglossus materials and method: computed tomography scans were taken for 53 iraqi adult patients (28 male and 25 female) range from (18-35) years with skeletal class i classification and intact anterior mandible dentition included in this study using sagittal and axial sections. the measurements were done for genial tubercle and anterior mandibular region. results: the mean values of some measurements weresignificantly higher in males than in females. the effect of gender difference was evaluated as a strong effect. the mean value of the other measurements slightly higher among males compared to females, but the difference fail to reach the level of statistical significance. the effect of gender difference on this parameter was evaluated as a moderately strong effect.the results showed that there was no effect of age on all selected measurements in male and female. all selected measurements showed no statistically significant linear correlation with the age. conclusions: the variable position and dimensions of this bone segment among patients suggest the need for ct before attempting genioglossus advancement for exact localization, avoiding the expected surgical complication keywords: genioglossus advancement, genial tubercle, computed tomography. (j bagh coll dentistry 2014; 26(3):6365). introduction genial tubercles (gts) are small bony protuberances on the lingual aspect of the mandible in the area of the symphysis, slightly above the inferior border of the mandible theyhave the form of spines often distributed as right and left protuberances and superior and inferior tubercles. these structures are a point of attachment for the genioglossus and geniohyoid muscles (1). the genioglossus muscle originates from the superior mental spine or gts and then fans posteriorly to insert at the tip of the tongue, at the dorsum of the tongue, the superior fibers retract the tip of the tongue, whereas the middle fibers depress the dorsum of the tongue (2). sleep apnea (osa) is a syndrome result from complete upper airway obstruction. multiple levels of the upper airway including retropalatal retrolingual, and hypopharyngeal can obstruct and produce osa. in the surgical treatment of osa, multiple sites of obstruction should be addressed to effectively treat the syndrome. the base of tongue or retrolingual region has long been identified as one of the critical sites that can contribute to osa (3). mandibular osteotomy with genioglossus advancement (ga) addresses upper airway obstru (1)m.sc. student. department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. ction at the base of the tongue. the genioglossus muscle is attached to the lingual surface of the mandible at the gt and also to the hyoid complex just above the larynx. movement forward of either or both of these anatomic structures will stabilize the tongue base along with the associated pharyngeal dilatators. ga enlarges the retrolingual airway specifically by advancing forward the gt of the mandible through a limited parasagittal mandibular osteotomy, thereby forcing an anterior advancement of the tongue base. the procedure achieves a greater hypopharyngeal space. the most serious complications of this procedure are mandibular fracture, which occurs when the osteotomy violates the inferior border of the mandible or induces lesions at the roots of the teeth. other complications include infection, permanent anesthesia, and seroma (4). the computed tomography (ct) scan is an imaging method that uses x-rays to create cross sectional pictures of the body. computer crates separate image of body area called slices were can be stored, viewed on monitor or printed on film (5,6) .three dimensional spiral ct has been used in clinics extensively because of its high resolution and the availability of 3-dimensional reconstruction. the maximum resolution of spiral ct, so the images obtained from scanning and reconstruction are sufficiently distinct to allow the examination and measurement of tiny structures, such as the gt (7). j bagh college dentistry vol. 26(3), september 2014 validity of computed oral diagnosis 64 materials and methods prospective study of ct scans were taken for 53 iraqi adult patients (28 males and 25 females) with (18-35) years ages range. those patients attending alkarkh general hospital in baghdad city taking ct scans for different diagnostic the current study included patients with class i skeletal relationship as the anb angle range from 2-4 degrees, no congenital craniofacial anomalies, intact anterior mandibular dentition, no previous fracture or bony surgery on anterior mandible and no obvious facial asymmetry .spiral ct machine which was used in this study is multi-slice spiral computed tomography scanner(philips brilliance ct 64). the selection of the subject sample with class i skeletal relationship made by measuring the anb angle on sagittal section of ct image, (the anb angle for cl. i range between (2-4)) (8). gt located on the lingual surface of the mandible, near the midline, by spiral ct sagittal and axial sections were selected for accurate capturing of mandibular bone segment attached to the genioglossus muscle. all measurements done in millimeter (7) as follow:sagittal section: mandibular thickness (mt): was measured at the level of superior margin of superior genial spine (sgs) and at the level of inferior margin of sgs then averaged to give a single value, superior genial spine height (sgsh) ; by measuring the distance from superior margin of sgs to inferior margin of sgs, li-sgs: by measuring the vertical distance from lower central incisor apices (li) to superior margin of sgs. ibm/sgs: by measuring the distance from inferior border of mandible (ibm) to inferior margin of sgs. axial section, superior genial spine width (sgsw): by measuring the widest dimension of sgs from side to side. results from the measurements done at the examined area on sagittal and axial sections, selected measurements were obtained demonstrated in table (1) for the total study sample. table 1: mean values of the selected measurements in total study sample the selected measurements mean age (years) 26.4 mandibular thickness at level of superior margin of sgs (mm) 10.5 mandibular thickness at level of inferior margin of sgs (mm) 12.6 mean mandibular thickness at level of sgs (mm) 11.6 sgs height (mm) 6.3 (li-sgs) vertical distance from lower central incisor apices to superior margin of sgs (mm) 5.6 (ibm-sgs) vertical distance from inferior border of mandible to inferior margin of sgs (mm) 10.2 (ibm-li) vertical distance from inferior border of mandible to lower central incisor apices (mm) 22.0 ratio of (li-sgs) to (ibm-li) 0.25 ratio of (ibm-sgs) to (ibm-li) 0.46 ratio of (sgs height) to (ibm-li) 0.28 sgs width (mm) 6.6 as shown in table (2), there were no obvious or statistically significant linear correlation between age and any of the measurements included in the present study as followingage showed no statistically significant linear correlation with mandibular thickness at level of superior margin of sgs (r=0.241, p=0.08).age showed no statistically significant linear correlation with mandibular thickness at level of inferior margin of sgs (r=-0.189, p=0.17).age showed no statistically significant linear correlation with mean mandibular thickness at level of sgs(r=-0.228 , p=0.1).age showed no statistically significant linear correlation with sgs height (r=-0.05 , p=0.72). age showed no statistically significant linear correlation with lisgs (r=-0.01, p=0.95)age showed no statistically significant linear correlation with ibm-sgs (r=0.047, p=0.74).age showed no statistically significant linear correlation with ibm-li (r=0.007, p=0.96)age showed no statistically significant linear correlation with ratio of (lisgs) to (ibm-li) (r=-0.019, p=0.89).age showed no statistically significant linear correlation with ratio of (ibm-sgs) to (ibm-li) (r=0.085, p=0.54).age showed no statistically significant linear correlation with ratio of (sgs height) to (ibm-li)( r=-0.089, p=0.53).age showed no statistically significant linear correlation with sgs width (r=-0.171, p=0.22). j bagh college dentistry vol. 26(3), september 2014 validity of computed oral diagnosis 65 table 2: liner correlation coefficient between age and selected measurements selected measurements age (years) mandibular thickness at level of superior margin of sgs (mm) r=-0.241 p=0.08[ns] mandibular thickness at level of inferior margin of sgs (mm) r=-0.189 p=0.17[ns] mean mandibular thickness at level of sgs (mm) r=-0.228 p=0.1[ns] sgs height (mm) r=-0.05 p=0.72[ns] (li-sgs) vertical distance from lower central incisor apices to superior margin of sgs (mm) r=-0.01 p=0.95[ns] (ibm-sgs) vertical distance from inferior border of mandible to inferior margin of sgs (mm) r=0.047 p=0.74[ns] total vertical height of mandibular border (mm) r=0.007 p=0.96[ns] ratio of (li-sgs) to (ibm-li) r=-0.019 p=0.89[ns] ratio of (ibm-sgs) to (ibm-li) r=0.085 p=0.54[ns] ratio of (sgs height) to (ibm-li) r=-0.089 p=0.53[ns] sgs width (mm) r=-0.171 p=0.22[ns] inter-canine distance (mm) r=0.02 p=0.89[ns] discussion the current study using ct demonstrated that gt varied in position and dimensions among subjects. ct can provide an accurate, non distorted view. this radiographic technique may prove useful in pre-operative planning for the mandibular osteotomy in genioglossus advancement procedures. ga has four major requirements: (1) preventing dental root damage, (2) incorporating most of the genioglossus muscle, (3) avoiding mandible fracture, and (4) maximizing the amount of genioglossus advancement (9). it is critical to accurately identify the gt, lower anterior teeth, and inferior border of the mandible in preparation for ga to manage osa (10). the advancement is also challenged by the need to avoid mandible fracture and prevent dental root damage. these issues are determined by the anatomic structure of the anterior mandible, including the gt, an anatomic structure with most of the genioglossus muscle attachment, lower anterior teeth and symphysis region. thus, surgeons need accurate measurements of these structures to aid in preoperative planning conebeam computed tomography. spiral ct is a relatively new radiology technology that offers less radiation exposure than conventional ct. the mean values of the selected measurements were shown in table (1) for the current study. yin et al (7) found that mt was 12.0 mm and these seem to be close to the finding of this study .yin et al (7) found that the mean value of sgsh was 5.82 mm and this agreed with the results of the present study.. zhang et al (11) and mintz et al (12) measured the distance from the inferior central incisor apex to the superior genial spine li-sgs as 6.83mm and 6.45 mm respectively and these were in agreement with the current study. regarding the gtw, mintz et al (12) reported that the mean value of gtw was 6.0 mm in their study, yin et al (7) found the gtw value was 6.98 mm.; these results were close to findings of the present study. also in this study the measurement of ibm-sgs value was close to that obtained by yin et al (7) chinese cadaver; they reported the mean value of ibmsgs was 10.5mm.the important of ibm-sgs distance above the inferior border of the mandible to prevent mandible fracture references 1baldissera ez, silveira hd. radiographic evaluation of the relationship between the projection of genial tubercles and the lingual foramen. dentomaxillofacial radiology 2002; 31: 368-72 2barbick mb, dolwick mf. genial tubercle advancement for obstructive sleep apnea syndrome: a modification of design. j oral maxillofac surg 2009; 67:1767-70 3hennessee j, miller fr. anatomic analysis of the genial bone advancement trephine system’s effectiveness at capturing the genial tubercle and its muscular attachments. otolaryngology–head and neck surgery 2005; 133: 229-33. 4won chj, li kk, guilleminault c. surgical treatment of obstructive sleep apnea. am thoracic society pats 2008; 5(2): 193-9 5grossholz tm, becker spiral ct of the abdomen. springer; 2002. pp.1-10 6white sc, pharoa mj. oral radiology principles and interpretations. 6th ed. mosby; 2009. pp. 597-610 7yin sk, yi hl, lu wy, et al. anatomic and spiral computed tomographic study of the genial tubercles for genioglossus advancement. otolaryngology–head and neck surgery 2007; 136: 632-7 8rakosi t. atlas and manual of cephalometric radiology. 2nd ed. london: wolf med publication; 1982. 9agarwal s, gaurav i, agarwal r, ahluwalia ks. determination of genial tubercle position and dimensions using cone-beam computerised tomography. indian j medical specialties 2013; 4(1): 29-33 10miller rj, edwards wc, boudet c, cohen jh. maxillofacialanatomy: the mandibular symphysis. j oral implantol 2011; 37: 745-53 11zhang x, bell wh, washko pw. relationship of mandibular anterior tooth apices to genial muscle attachments. oral surg oral med oral pathol 1988; 65: 653– 6 12mintz sm, ettinger ac, geist jr, geist ry. anatomic relationship of the genial tubercles to the dentition as determined by cross-sectional tomography. j oral maxillofac surg 1995; 53(11):1324-6. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p): 1817-1869, issn (e): 2311-5270 37 research article effects of various analgesics on pain perception and rate of tooth movement: a randomized controlled clinical study asem a m abdaljawwad1, dheaa h al-groosh2 1 department of orthodontics, college of dentistry, university of anbar, iraq. 2 department of orthodontics, college of dentistry, university of baghdad, iraq. * correspondence: dheaaha73@yahoo.com abstract: background: pain is one of the most reported side effects of orthodontic treatment despite the advanced technology in orthodontics. many analgesics have been introduced to control orthodontic pain including acetaminophen and selective and nonselective nonsteroidal anti-inflammatory drugs. the great concern about these drugs is their adverse effect on rate of teeth movement. aims: the purpose of this study was to evaluate and compare the effect of acetaminophen, ibuprofen and etoricoxib on pain perception and their influence on the rate of teeth movement during leveling and alignment stage. methods: forty patients were evenly and randomly distributed in a blinded way to one of four groups: placebo (starch capsules), acetaminophen 500mg thrice daily, ibuprofen 400mg thrice daily, and etoricoxib 60mg once daily. the drugs were given one hour before bonding and archwire placement and continued for three days. a visual analogue scale was used to express pain levels before and after archwire placement, on the first, second, third, and seventh day. little’s irregularity index was measured before bonding and at every activation visit until the end of the alignment and leveling stage. results: all three drugs showed a lower pain level than placebo at the bonding and first activation visits. etoricoxib showed the least pain level among other drugs followed by ibuprofen. no statistically significant differences were found between the drug groups and the placebo at the second and third activation visits. no statistically significant differences were detected between the 4 experimental groups concerning the rate of teeth movement. conclusions: the three drugs were only effective in controlling pain during the first two visits of orthodontic treatment; and etoricoxib 60mg/day was the best. all three drugs had no influence on rate of teeth movement when used in their least recommended dose. keywords: orthodontic pain, pain perception, etoricoxib, analgesics. introduction orthodontic pain was reported to be one of the most negative effects of orthodontic treatment, it has been rated as a major reason for discontinuing treatment (1-3). previous studies have well documented that orthodontic pain begins between 4h 12h after orthodontic force application, peaks after 1 day, gradually subsides 3–7 days thereafter and returns to baseline levels after 1 month (4-6). non-steroidal anti-inflammatory drugs (nsaids) have been used for the relief of orthodontic pain for decades. their effectiveness in orthodontic pain relief has been validated, but their side effect of reducing the rate of tooth movement is still being debated (7-9), making nsaids not routinely used for pain control in orthodontic practice. received date: 12-12-2021 accepted date: 20-1-2022 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/jbc d.v34i2.3144 mailto:dheaaha73@yahoo.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i2.3144 https://doi.org/10.26477/jbcd.v34i2.3144 j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 38 traditional nsaid are nonselective for two isoforms of cyclooxygenase (cox), cox-1 and cox-2. cox-1 is related to the synthesis of prostaglandins involved in the protection mechanism of the gastric mucosa, while cox-2 is induced after the inflammatory cells have been activated and participate in the synthesis of inflammation and pain mediators (10). in this context, nsaids selective for cox-2 were newly developed, to overcome cox-1 inhibition side effects (11). acetaminophen was suggested to be the most effective drug that corroborates its pharmacological use in orthodontic movement disturbances, it seems to have no role in the synthesis of prostaglandins(12,13). however, there is still no precise recommendation regarding the most adequate drug for pain control in orthodontic treatment. in this context, determining the nsaid that reduces pain the most without influencing the rate of tooth movement becomes essential to optimize the orthodontic treatment (7,13,14). the aims of the present study were to compare the analgesic effect of etoricoxib (a selective nsaid), ibuprofen (a nonselective nsaid), and acetaminophen on the orthodontic pain generated after archwire placement and/or activation during the alignment and leveling stage, and to find if there is any effect of these analgesics on the rate of teeth movement. materials and methods ethical approval and subjects this randomized, double-blinded, placebo-controlled, prospective study was approved by the ethical committee of the college of dentistry/ university of baghdad on the 24th february 2020 with ref. number 186420. a total of forty patients (age ranged between 18 and 24 years old) who were about to receive fixed orthodontic appliance treatment agreed to enroll in this study. the patients were informed about the procedure through a detailed information sheet, and written informed consent was obtained. sample size was measured according to a predetermined 80% power of study and 5% significance alpha level. selection criteria patients must have a full set of permanent dentitions excluding the third molars. no antibiotic treatment for at least four weeks before bonding. no history of systemic diseases or allergies. no current use of steroids or analgesics. not contraindicated to nsaid. must not extract teeth at least 4 weeks before bonding. no history of previous orthodontic treatment. moderate crowding of a maximum of 10mm according to little’s irregularity index (lii) (15). this study was done in the orthodontic clinic at the college of dentistry/ university of baghdad in addition to a private specialized dental center in baghdad city. blinding and randomization forty-four patients (age ranged between 18 and 24 years old) were recruited; however, three patients did not meet the oral hygiene requirement (gi or pli >1). the remaining forty-one patients were randomly j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 39 assigned to one of four study groups. a simple non-stratified randomization was done using randomly assign subjects to treatment groups website (https://www.graphpad.com/quickcalcs/randomize1/) with an equal allocation ratio (10 participants per group except group b contained 11patients). the allocation was performed by an independent person. the groups were named as a, b, c, and d and both the patient and the investigator (a.a.m.a), who was responsible for the clinical part of the study, were blinded to the type of analgesic that were given to each group as well as to the grouping itself, which was kept sealed until the completion of data analysis. the drug tablets did not have any markings or labels that represent brand name, and were put in small opaque pill boxes with a sticker containing the name of the group. the pills were put in the boxes by the independent person. study groups four experimental groups were predetermined: group a, were given a placebo (starch capsule) once daily (considered as the control group); group b, were given 500 mg acetaminophen (paracetamol, pristol house, unit 3, canalside, northbridge road, berkhamsted hertfordshire, united kingdom) three times daily; group c, were given 400 mg ibuprofen (denk pharma, gmbh & co. kg, prinzregentenstr., münchen, germany) three times daily; and group d, were given 60 mg etoricoxib (arcoxia, merck sharp & dohme b.v., waarderweg haarlem, netherlands) once daily. the lowest recommended dose for each medication was used according to the national health service, uk. drug administration began 1 hour before commencing the bonding procedure and/or archwire change, and were given for three days including the bonding day. patients were instructed not to take any additional analgesics. a standardized treatment protocol was followed for all participants. the same day after placing the fixed orthodontic appliance, a 0.012-inch archwire was placed for alignment as a starting arch wire and the usual wire consequence was followed (0.014-inch niti followed by 0.016-inch niti, then 18-inch niti) at 6 weeks visit intervals. archwires were fully tied to the brackets by either ligature wires or elastomeric modules (rotated teeth were ligated with ligature wires). to ensure standardization, any debond happened during the treatment was rebonded within 24 hours, otherwise the case will be excluded. patients were all reminded about their upcoming visits via cell phone call one day before appointment. pain assessment patients recorded the pain perceived on a graded linear visual analogue scale (vas). subjects were given routine post-bonding instructions and were thoroughly trained on how to deal with the vas. then patients were asked to complete a questionnaire at appropriate intervals during the week after the bonding appointment. the questionnaire was in the format of a printed six-page booklet that contained 100 mm horizontal vas on which patients were asked to mark the degree of discomfort at the indicated time periods. the patients were instructed to make a check on the scale at each time interval to represent the perceived severity of pain during each of the three activities: https://www.graphpad.com/quickcalcs/randomize1/ j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 40 chewing, fitting or occluding on the front teeth, and fitting the back teeth. incidence and severity of pain were recorded by the patient prior to bonding and drug administration, immediately after bonding, and on the first, second, third and seventh day after bonding. patients were asked to return the questionnaire on the seventh day. this questionnaire was repeated for all activation visits until the end of the alignment stage. a text message reminder was sent to every patient to remind them to mark the questionnaire on the scheduled day. all of the forty patients who enrolled in this study returned their questionnaires, and none of them were recorded to use additional medication. rate of tooth movement the rate of tooth movement was estimated by measuring the lii for the lower arch before appliance bonding and at each archwire changing visit which was made every 6 weeks till the end of alignment stage directly in patients’ mouth using a four-digit caliper with tenth of a millimeter. the difference between each measurement and its previous one determined the amount of teeth movement for that visit. in the present study we have calculated the rate of teeth movement four times before it reached zero crowding. lii is a quantitative method of assessing the anterior teeth irregularity. the technique involves measurement of teeth irregularities directly from the patient’s mouth or from the dental cast with a caliper (four-digit caliber with a tenth of a millimeter) held parallel to the occlusal plane. the linear displacement of the adjacent anatomic contact points of the incisors is determined, and the sum of the five measurements represents the irregularity index value of a case (15). statistical analysis the statistical analysis was performed using spss 22 on windows 10 software (spss inc., chicago, illinois, usa). data distribution of the vas scores for pain levels was checked using shapiro-wilk test. descriptive statistics were done for all data. age differences between groups were evaluated using one-way anova (analysis of variance). all statistical comparisons done included all the three different actions (chewing, fitting anterior teeth and fitting posterior teeth) at each time interval, and were repeated for each archwire changing visit. comparisons within each drug group over time by means of pain were done using wilcoxon test with bonferroni correction, and since 45 multiple comparisons were made for each group, a significance value of p < 0.0011 was considered significant. differences between the drug groups to compare pain over time were evaluated using kruskal wallis test. in the first and third orthodontic visits, ten actions were found to be statistically significant, so mann whitney test with bonferroni correction was done. as sixty multiple comparisons were made, a significant value of p < 0.00083 was considered to be significant. in the second orthodontic visit, 14 actions were found j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 41 statistically significant, the bonferroni correction of mann whitney test indicated considering a significance value of p < 0.0006 to be significant because 84 multiple comparisons were made. in the fourth orthodontic visit, only 6 actions were found statistically significant, so mann whitney test with bonferroni correction was done, and a significance value of p < 0.0014 was considered significant, since 36 multiple comparisons were made. intraclass correlation coefficient (icc) was used to test the inter-examiner reliability of the lii of a twelve randomly selected patients, lii was remeasured by another investigator at the same visit. the rate of teeth movement was compared between the drug groups using one-way anova test. results one patient from group b missed to record the pain assessment form and, therefore, were dropped out of the study. the remaining 40 patients who participated in our study completed the whole procedures until the end of their alignment and leveling stage and returned all their pain assessment forms. the consort flowchart of the current trial is shown in figure 1. patient recruitment started in november 2020 and completed in may 2021. descriptive statistics of the patients’ age for the four groups was calculated as shown in table 1. the average age for the four groups was not significantly different from each other (p < 0.05). gender differences were not taken into consideration. pain levels of the drug groups in all the study groups, the pain level reached its peak after 24 hours of archwire placement and/or activation, this was true through all different actions and in all activation visits. interestingly, no statistically significant differences (p < 0.0011) were detected between different time intervals for all activities within the same group. table 1 descriptive statistics and distribution of age in the study groups. group drug n mea n std. deviation min . ma x. f p a placebo 10 21 2.055 18 24 0.139 0.936 b acetaminophen 10 20.9 1.792 19 24 c ibuprofen 10 21.4 1.506 19 23 d etoricoxib 10 21.2 2.098 19 24 total 40 21.13 1.814 18 24 all the data are presented as mean (95% confidence interval). j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 42 figure 1. consort flowchart of participants through each stage of the study. pain levels between the drug groups after the bonding visit and at 24 and 72 hours; ibuprofen, acetaminophen and placebo groups had a comparable pain levels, while etoricoxib group showed a superior analgesic effect over them at chewing and fitting on anterior teeth and the differences were statistically significant (p < 0.00083) (table 2). after 48 hours etoricoxib, ibuprofen and acetaminophen groups had a comparable analgesic effect during chewing, but all showed significantly (p < 0.00083) higher analgesic effect than placebo group. however, etoricoxib group showed significantly (p < 0.00083) less pain levels than ibuprofen and acetaminophen groups during fitting on anterior teeth (table 2). results after the first activation visit showed significant higher pain levels in the placebo group over other drug groups (p < 0.0006) in all actions. at the first day, etoricoxib group presented with significantly lower pain levels (p < 0.0006) than ibuprofen group during fitting on anterior teeth, and lower than acetaminophen group during chewing and fitting on posterior teeth. ibuprofen group was better in controlling pain than acetaminophen group only during fitting on posterior teeth, the difference was significant (p < 0.0006) (table 2). j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 43 at the second and third days, etoricoxib and ibuprofen groups had a comparable pain levels, however, these were lower than that of acetaminophen group during fitting on posterior teeth (p < 0.0006), in addition, ibuprofen group showed significantly lower pain levels than acetaminophen group chewing (p < 0.0006) (table 2). no statistically significant differences were found between the drug groups after the second and third activation visits, except that etoricoxib showed a significantly (p < 0.00083) better analgesic effect than acetaminophen group during fitting on anterior teeth at day 3 (table 2). table 2 pain levels of the four groups at measured functions and time intervals. action time placebo acetaminophen ibuprofen etoricoxib chewing day 1 33 (15-55)a 56 (30-75)b 29 (15-40)b 33 (20-45)a 19 (10-25)b 7.2 (0-13)a 9.4 (3-18)b day 2 58 (50-70)a 66 (25-100)b 28 (15-50)a 20 (10-35)b 24 (5-35)a 3 (0-5)b 14.2 (8-20)a 7.2 (0-18)b day 3 40 (15-55)b 23 (15-35)a 15 (5-25)b 2 (0-5)b 4.6 (0-10)a 5.2 (0-13)b day 7 22 (5-40)b 15 (5-25)b 2 (0-5)b fitting on front teeth day 1 56 (45-70)b 54 (45-70)a 22 (20-25)b 21.6 (13-35)a 9.4 (3-18)b day 2 54 (40-80)a 65 (40-85)b 39 (20-55)a 31 (20-60)a 19 (15-25)b 15.6 (13-20)a 7.2 (0-18)b day 3 37 (20-80)a 32 (20-55)b 26 (15-60)c 45 (30-60)a 5 (0-10)a 6 (0-15)b 11.2 (8-15)c day 7 29 (10-60)b 20 (10-30)a 16 (10-20)b 2 (0-5)b 4.6 (0-10)a 4 (0-10)b fitting on back teeth after bonding/ archwire replacement 21 (10-40)b 2.2 (0-5)b day 1 59 (25-85)b 21 (20-25)b 9 (0-15)b 7.4 (3-13)b day 2 64 (50-75)a 64 (20-100)b 11 (0-35)a 19 (15-25)b 2 (0-5)b 13.2 (3-20)a 5.2 (0-13)b day 3 42 (10-65)b 22 (15-35)b 3 (0-10)b 4 (0-10)b day 7 27 (10-50)b 2 (0-5)b 3.2 (0-8)b a: significant differences were found at bonding visit (p < 0.00083), b: significant differences were found at the first activation visit (p < 0.0006), c: significant differences were found at the second activation visit (p < 0.00083). j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 44 rate of teeth movement of the drug groups the mean rate of teeth movement measured at the first visit after 6 weeks of bonding and loading the initial arch wire (first activation) were 2.192 ± 0.735 mm for placebo group, 3.972 ± 1.929 mm for acetaminophen group, 2.468 ± 1.95 mm for ibuprofen group, and 3.4 ± 1.158 mm for etoricoxib group (table 3). after the second activation (12 weeks after bonding), the mean rate of teeth movement calculated were 2.09 ± 1.07 mm for placebo group, 2.748 ± 1.3 mm for acetaminophen group, 3.252 ± 0.904 mm for ibuprofen group, and 2.414 ± 0.519 mm for etoricoxib group (table 3). the mean rate of teeth movement estimated after the third activation (18 weeks of starting alignment and leveling) were 1.92 ± 2.138 mm for placebo group, 1 ± 1.302 mm for acetaminophen group, 1.16 ± 1.055 for ibuprofen group, and 2.266 ± 2.352 mm for etoricoxib group (table 3). the calculated means of teeth movement after the fourth activation (24 weeks after bonding) were 1.3 ± 0.544 mm for placebo group, 1 ± 0.289 mm for acetaminophen group, 0.9 ± 0.155 mm for ibuprofen group, and 1.25 ± 0.866 mm for etoricoxib group (table 3). table 3 descriptive statistics of the rate of teeth movement in drug groups. time groups n mean std. deviation min. max. first activation (after 6 weeks) placebo 10 2.192 0.73525 1.29 3.02 acetaminophen 10 3.972 1.92894 1.26 6.6 ibuprofen 10 2.468 1.95013 0.19 5.85 etoricoxib 10 3.402 1.15817 1.96 5 total 40 3.0085 1.64139 0.19 6.6 second activation (after 12 weeks) placebo 10 2.09 1.06531 1.15 4.05 acetaminophen 10 2.748 1.30043 1.6 4.7 ibuprofen 10 3.252 0.90444 2.5 4.9 etoricoxib 10 2.414 0.51938 1.72 3.25 total 40 2.626 1.04531 1.15 4.9 third activation (after 18 weeks) placebo 10 1.92 2.13817 0 4.4 acetaminophen 10 1 1.30171 0 2.75 ibuprofen 10 1.16 1.05536 0 2.5 etoricoxib 10 2.266 3.92046 0 9.58 total 40 1.5865 2.35197 0 9.58 fourth activation (after 24 weeks) placebo 6 1.3 0.54406 0.9 2 acetaminophen 4 1 0.28868 0.75 1.25 ibuprofen 6 0.9 0.15492 0.7 1 etoricoxib 4 1.25 0.86603 0.5 2 total 20 1.11 0.49778 0.5 2 all the data are presented as mean (95% confidence interval). j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 45 rate of teeth movement between the drug groups intra class correlation coefficient revealed a high reliability level [icc = 0.976 (95% ci 0.917 ̶ 0.993)] for lii (table 4). table 4 intraclass correlation coefficient. intraclass correlation 95% confidence interval f test with true value lower bound upper bound value df1 df2 sig single measures 0.953 0.847 0.986 38.578 11 11 0.000 average measures 0.976 0.917 0.993 38.578 11 11 0.000 no statistically significant difference (p < 0.05) was detected by anova test between the different experimental groups through the whole alignment and leveling period (after the first, second, third and fourth activations after bonding) (table 5). table 5 anova test for comparisons of rate of teeth movement between drug groups after different activation times. activation sum of squares df mean square f sig. first activation between groups 20.42 3 6.807 2.895 0.058 within groups 84.652 36 2.351 total 105.072 39 second activation between groups 7.39 3 2.463 2.518 0.074 within groups 35.224 36 0.978 total 42.614 39 third activation between groups 10.988 3 3.663 0.644 0.592 within groups 204.75 36 5.688 total 215.739 39 fourth activation between groups 0.608 3 .0203 0.791 0.517 within groups 4.1 16 0.256 total 4.708 19 discussion one of the most common complaints among orthodontic patients is pain, especially during the first week of fixed appliance placement and the ongoing activation and archwire changing visits. many factors have been reported to affect the severity of orthodontic pain such as age, force type, and type of personality (16), moreover, the amount of patients’ discomfort and attitude toward treatment found to effect on appliance acceptance (17). because of such important effect on patients’ compliance, pain management is a priority to ensure a successful orthodontic treatment. j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 46 pain is a subjective feeling caused and affected by many factors. several methods were suggested to assess pain in the literature and nearly all of them depends on subjective methods. like most of the orthodontic studies in the literature, vas was used in the current study to assess pain. it is found to be the most accepted and appropriate over other pain scales because of its ease of measurement and reproducibility (18,19). the current randomized controlled study was conducted on a total of 40 patients who scheduled to have fixed orthodontic appliance therapy. patients were randomly distributed into one of four experimental groups: patients in group a were given placebo (starch capsules), patients in group b administered 500 mg acetaminophen, patients in group c took 400 mg ibuprofen, and patients in group d administered 60 mg etoricoxib; in all four groups, medication was started 1 hour before the bonding/archwire activation procedure and continued for 3 days. all the patients completed the study without using any additional medications. the lowest recommended doses of acetaminophen, ibuprofen and etoricoxib were used to control pain (as suggested by national health service, uk). pain level scores were obtained using vas at the particular time intervals. the aims of this randomized placebo-controlled study were to assess the efficacy of acetaminophen, ibuprofen (non-selective nsaid), and etoricoxib (highly selective nsaid) administration on controlling orthodontic pain and their possible effect on the rate of orthodontic tooth movement. the uniqueness of the current study is that pain evaluation was conducted through the whole leveling and alignment period over about 6 months of orthodontic treatment, with repeating the pain control drugs and scoring process during the first week of each visit interval. rate of teeth movement was also measured through the same leveling and alignment period by measuring the amount of teeth movement at each visit interval. in the present study and through all activation visits, pain started immediately after archwire placement or activation and reached its peak after 24 hours in all study groups and all different activities, which markedly reduced at day 7. these findings were similar to previous studies (16,20-24). the average pain score on vas through the entire study did not exceed 67 on 100 mm scale in placebo group, indicating a moderate pain, which was in agreement with gupta et al (2014) (24), while in other drug groups the scores were below 44 mm, indicating a mild pain, these results were similar to what found by salmassian et al (2009) (16). analgesic effect within the same group of different activities at different time intervals showed no statistically significant difference in all experimental groups. for drug groups pain scores were all mild which made it difficult for the patients to detect a significant reduction in pain, besides, administration timing plays a significant role in the effectiveness of analgesics used for orthodontic pain management due to the differences in their plasma half-life (25). in the current study analgesics were given 1 hour preoperatively which allow enough time for them to reach a high plasma concentration before pain reached its peak levels. in the placebo group, even though patients didn’t take analgesic medications, no significant difference in pain levels were detected in response to different time intervals through different actions. this is mainly j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 47 due to the psychological effect of placebo drugs which could reach 30-40 % in medical and dental studies (26). pain evaluation at the bonding visit and at the first visit after bonding revealed that etoricoxib was the most effective drug in pain reduction among other groups, these results were statistically significant for all different actions after 24, 48, and 72 hours, where pain reached its peak levels. this was in agreement with (24) which was the only study in the literature comparing etoricoxib analgesic efficacy in controlling orthodontic pain to other drugs. a systematic review and meta-analysis which published recently concluded that placebo is the least effective, while etoricoxib is the most effective analgesic in controlling orthodontic pain (25). at the bonding visit ibuprofen and acetaminophen showed similar results in pain reduction with no statistically significant difference between them, but at the first visit after bonding (6 weeks after bonding) ibuprofen was significantly more effective than acetaminophen in reducing pain in fitting on posterior teeth and on chewing actions after 24, 48, and 72 hours. both drugs were significantly more effective than placebo in those time intervals. when these results compared to previous studies comparing ibuprofen to acetaminophen and placebo, conflicting results were found. bernhardt et al. (2001) (20) and bradley et al. (2007) (27) found that ibuprofen administration causes less pain than acetaminophen. another study which done by patel et al. (2011) (28) showed similar analgesic effect between acetaminophen and placebo, whereas ibuprofen revealed superior analgesic effect. however, bird et al. (2007) (29), salmassian et al. (2009) (16), and tunçer et al. (2014) (30) have found no statistically significant difference between acetaminophen and ibuprofen. a systematic review done by xiaoting et al. (2010) (31) concluded that there is no statistical difference detected between ibuprofen, acetaminophen or placebo. another more recent systematic review and meta-analysis indicated that ibuprofen can be effective in reducing pain after separators or archwire placement only after 2 and 6 hours compared to placebo, but not at 24 hours. ibuprofen and acetaminophen seem to be equally effective (32). the current study showed similar effect in reducing orthodontic pain between the four experimental groups at the second and third visits after bonding (12 and 18 weeks after bonding). it is widely known that teeth movement process happened by blood flow obstruction of the periodontal ligament (pdl) at the pressure site leading to the release of pe2 which activate bone resorption process (33). nsaids are the most common drugs given to control pain in patients act by blocking the pge2 production by inhibiting the cox enzyme and thus disrupting teeth movement as reported in many previous animal studies (34,35). on the other hand, the highly selective cox 2 inhibitor nsaids such as etoricoxib suggested to reveal a very little effect on teeth movement in comparison to conventional non-selective nsaids (24). unlike nsaids, acetaminophen is not an active anti-inflammatory agent and does not prevent pge2 production and teeth movement (30,36). previous studies have shown that acetaminophen consumption for orthodontic pain control has no significant effect on the rate of teeth movement (7,12,13,35,37,38), while ibuprofen administration negatively affect the rate of teeth movement (7,12,35,38). however, other studies concluded that ibuprofen and loxoprofen administration longer than two weeks did not have any significant effect on the rate of teeth movement j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 48 (39,40). recently, it has been demonstrated that only high doses of etoricoxib significantly decrease the rate of teeth movement (41). in the current study, no statistically significant differences were found between the four experimental groups through all activation visits till the end of the leveling and alignment period, these findings indicate that etoricoxib, acetaminophen, and ibuprofen drugs have no negative effect on the rate of orthodontic teeth movement when prescribed with their recommended doses for three days after each archwire placement and/or activation. the half-life period of the high selective cox-2 inhibitor etoricoxib is 22 hours and reaches its maximum concentration in blood plasma after one hour of oral intake, which is far longer than most of other non-selective nsaids (42). this have been shown clearly in the current study, a daily single dose intake of etoricoxib is more effective in orthodontic pain control than ibuprofen or acetaminophen given thrice daily. furthermore, etoricoxib have the least effect on the gastric mucosa and no inhibitory effect on teeth movement. based on the current randomized study, and for better pain control in patients undergoing orthodontic treatment, it is recommended to prescribe etoricoxib rather than acetaminophen or ibuprofen due to its excellent pain controlling ability without affecting the rate of teeth movement. it is also better to prescribe ibuprofen over acetaminophen because of its superior analgesic effect in the absence of decelerating teeth movement. conclusion pain resulting from routine orthodontic treatment is of moderate intensity, and in cases of analgesic prescriptions is of mild intensity. etoricoxib, ibuprofen and acetaminophen are significantly effective in reducing orthodontic pain in the first 3 months of treatment, but have the same effect as the placebo after that. etoricoxib was the best efficient analgesic in reducing orthodontic pain. ibuprofen is significantly better than acetaminophen in controlling orthodontic pain. etoricoxib, ibuprofen and acetaminophen when prescribed with their least recommended doses have no inhibitory effect on the rate of orthodontic teeth movement. conflict of interest: none. references 1. brown df, moerenhout rg the pain experience and psychological adjustments to orthodontic treatment of preadolescents, adolescents and adults. am j orthod dentofacial orthop 1991; 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(2008) effect of cyclooxygenase inhibitors on rat root resorption and tooth movement. phd thesis, university of south california, usa. 40. yamamoto t, kaku m, sumi h, et al. effects of loxoprofen on the apical root resorption during orthodontic tooth movement in rats. plos one 2018; 13: e0194453. 41. kirschneck c, küchler ec, wahlmann u, et al. effects of the highly cox-2-selective analgesic nsaid etoricoxib on the rate of orthodontic tooth movement and cranial growth. ann. anat. 2018; 220: 21–28. 42. patrignani, p., capone, m.l., tacconelli, s. clinical pharmacology of etoricoxib: a novel selective cox2 inhibitor. expert opin. pharmacother. 2003; 4, 265–284. j. bagh. coll. dent. vol. 34, no. 2. 2022 abdaljawwad and al-groosh 51 فعالية مسكنات األلم على إدراك األلم ومعدل حركة األسنان تجربة سريرية عشوائية. ضياء حسين الكروش د.ا.د.عاصم عباس عبد الجواد، : المستخلص من التطور من االدوية المسكنة الخلفية: يعتبر األلم احد اكثر اآلثار الجانبية لعالج تقويم االسنان بالرغم تم تقديم العديد مجال تقويم االسنان. العلمي في قائية. الهم االكبر فيما يخص للسيطرة على االلم الناتج عن تقويم االسنان وتشمل البراسيتامول و االدوية المضادة لاللتهاب الغير ستيرويدية االنتقائية والغير انت .حركة االسنان هذه االدوية هو انها تؤثر سلبا على معدل تأثيرهم على الهدف: الهدف من هذه الدراسة هو لتقييم ومقارنة تأثير كل من البراسيتامول والبروفين واالتوريكوكسب على االحساس بااللم ومعرفة مدى .معدل حركة االسنان في مرحلة تسوية وانتظام االسنان اختيارهم تم مريضا اربعون والطرق: النشاء(، المواد )كبسوالت وهمي عالج مجموعات: اربع احد على عمياء وبطريقة عشوائية بصورة وتوزيعهم ملغم مرة واحدة في اليوم. تم اعطاء االدوية قبل 60ملغم ثالث مرات في يوم، اإلتوريكوكسب 400ملغم ثالث مرات في يوم، البروفين 500البراسيتامول ت لمدة ثالثة ايام. تم استخدام مقياس التناظرية البصرية للتعبير عن مستوى االلم بعد وضع سلك التقويم ، وفي اليوم ساعة من وضع جهاز التقويم واستمر جهاز حتى نهاية االول والثاني والثالث والسابع. تم قياس مقدار فهرس ليتل لقياس تراكب االسنان قيل وضع جهاز تقويم االسنان وعند كل زيارة لتفعيل ال .سوية وانتظام االسنانمرحلة ت ى. اإلتوريكوكسب النتائج: جميع مجاميع االدوية الثالث اظهرت مستوى الم اقل من مجموعة العالج الوهمي بعد وضع جهاز التقويم وعند زيارة التفعيل االول ين مجموعات االدوية ومجموعة العالج الوهمي عند اظهر اقل مستوى لاللم من بين جميع االدوية يأتي من بعده البروفين. ال وجود الختالف احصائي بارز ب .زيارات التفعيل الثانية والثالثة. ال وجود الختالف احصائي بارز بين جميع المجموعات االربع فيما يخص معدل تحرك االسنان ملغم 60زيارتين االولى والثانية، وان االتوريكوكسب اإلستنتاج: جميع االدوية الثالث فعالة فقط في السيطرة على االلم الناتج من عالج تقويم االسنان في ال .مرة واحدة في اليوم هو االفضل. جميع االدوية الثالث ليس لها تأثير على معدل حركة االسنان عند استعمالها ضمن الحد االدنى الموصى به j bagh college dentistry vol. 29(2), june 2017 mechanical evaluation restorative dentistry 42 mechanical evaluation of nano hydroxyapatite, chitosan and collagen composite coating compared with nano hydroxyapatite coating on commercially pure titanium dental implants sabreen w. ibrahim, b.d.s. (1) widad a. al nakkash, b.d.s., h.d.d.,m.sc.(2) abstract background: dental implants act as infrastructure for fixed restoration to look like as a natural tooth. osseointegration is a biological events and considered as a base for success of dental implant. the aim of this study is to evaluate the bond strength between bone and ti implant coated with mixture of nano hydroxyapatite-chitosancollagen compared with ti implants coated with nano hydroxyapatite implanted in rabbit tibia, after different period of implantation time (two and six weeks) by torque removal test. material and methods: 36 screws of commercially pure titanium; 8mm in length and 3mm diameter , 18 screws coated with mixture of nano hydroxyapatite-chitosan-collagen and18 screws coated with nano hydroxyapatite by dip coating. structural characteristics was assessed by scanning electron microscope, and ftir analysis. the screws were implanted in 18 healthy adult male new zeeland rabbits each tibia received one screw, right tibia received screw coated with nano hydroxyapatite while left tibia received screw coated nano hydroxyapatite-chitosancollagen composite. removal torque test was done by torque meter to determine the highest torque value necessary to remove the implants from tibia bone after different period of time of implantation(2 and 6 weeks). result: nano hydroxyapatite-chitosan-collagen composite coating was resulting in higher torque removal value than nano hydroxyapatite coating for two periods of time. conclusion: concluded that addition of collagen and chitosan to nano hydroxyapatite was more efficient in rapid bone formation than nano hydroxyapatite only. keywords: osseointegration, nano hydroxyapatite, chitosan, collagen, ftir analysis. . (j bagh coll dentistry 2017; 29(2):42-48) introduction dental implant was considered an accepted alternative treatment to restore missing teeth and tissues. titanium shows an excellent biocompatible nature and minimum foreign body reaction in comparison with other conventional materials (1, 2). during the past decades, many researchers suggested that increasing the local quality and quantity of the surrounding tissue for favorable osseointegration (3). many studies have concentrated on finding methods to increase and improve osseointegration, providing adequate mechanical integrity to resist occlusal forces at an early period (4, 5). bone involve organic and inorganic material within extracellular matrix, the organic constitute is the collagen, the tensile strength of bone is contributed to collagen fiber. while the inorganic component of bone is the hydroxyapatite (6). amongst other types of calcium phosphate, hydroxyapatite considered the best bioactivity. hydroxyapatite (ha) has ability to improve adhesion, migration, differentiation and proliferation of osteoblast; which is important for bone renewal (7). (1) master student, prosthodontics department, dentistry collage, university of mustansira (2) professor, prosthodontics department, dentistry collage, university of al sraa chitosan is nontoxic biocompatible biomaterial with antimicrobial activity, so the chitosan is widely used in biomedical application (8). the abundant protein in the animal kingdom is the collagen, collagen forming about 25% of the total protein content of the body (9). the purpose of this study was to evaluate the effect of mixture from nano hydroxyapatite, chitosan and collagen composite coating compared with nano hydroxyapatite coating materials on the strength of bone-implant interface after implantation in rabbit tibia bone by means of torque test. material and methods sample preparation commercially pure titanium discs (grade 2), 29mm diameter and 2mm thickness was used as substrate for coating, these ti discs have a polished mirror surface placed in ultrasonic bath of ethanol in order to get rid of contamination and debris in 15 minutes, then for 10 minutes in distilled water bath(10). after that the specimens left to dry at room temperature to be used in the pilot study pilot study 1-coating solution preparation eighteen screws coated by nano ha by dip coating (nano ha solution prepared by dissolving0.01g of p2o5 in 50ml of ethanol, after half an hour of stirring on hot stirrer, add 7 g of j bagh college dentistry vol. 29(2), june 2017 mechanical evaluation restorative dentistry 43 nano ha powder ,then sintered to 400ºc under inert gas (argon) (9). eighteen screws coated with nano ha-chitosan-collagen mixture by dip coating for 2 minutes (0.5 g of chitosan dissolved in 50 ml of 2% acetic acid then add 1µg/ml of collagen then this solution mixed with nano ha solution that prepared as 4g of nano ha dissolved in 50 ml of absolute alcohol (ethanol)). 2heat treatment heat treatment(sintering) for densification of coated discs by using carbolated furnace, heat treatment done for one hour under inert gas, for nanohyroxyapatite coating substrate, best heat treatment was at 400ºc (10). while the nanohyroxyapatite, chitosan and collagen composite coating, best heat treatment was at 100ºc. because heating above this temperature was resulted in burning of coating material as shown in figure(1). (a) (b) (c) (figure1): heat treatment (a) heat treatment at 300ºc. (b) heat treatment at 150ºc. (c) heat treatment at 100ºc. test performed on coated ti discs 1ftir analysis ftir analysis was used to identify the organic and inorganic materials, within scanning range between 400 to 4000cm-1. 2scanning electron microscope (sem) sem analysis was used for evaluating the surface morphology and topographical characteristics and particle size of coated substrate. implant preparation commercially pure titanium (grad2) rod 6 mm diameter, shaped by lathe machine into screw shape implants, thirty six screws shaped implants,3 mm diameter and 8mm length (threaded part is 5mm, 3mm length of smooth part), with slit in the head of implant, 1mm depth to fit the screwdriver during implantation. these screws washed in ethanol in an ultrasonic cleaner for 15 minutes to remove the debris and contamination, then dried at room temperature, after that coated according to pilot study results as shown in figure (2). (figure2): coated screws. surgical procedure eighteen healthy adult male new zeeland rabbits 10-12 months age and 2-2.5 kg weight were used. before surgical operation, the rabbits were left in same environment with antibiotic cover by oxytetracycline intramuscular injection to exclude any infection before operation. anesthesia was given to rabbits by intramuscular injection of ketamine hydrochloride (1ml/1kg body weight) and xylocaine 2 %( 1ml/1kg body weight), so each rabbit must weighted before surgical procedure to determine appropriate amount of anesthesia which must be given to each rabbit. after shaving of skin and cleaning with alcohol, incision was made on the medial side of tibia then reflection must made to expose the bone, handpiece used to prepare hole on the bone (2.5mm in diameter), drilling must be gently with continuous cooling to prevent damage the bone.one hole prepared on right tibia to insert nanoha coated screw within it, and one hole on the left tibia to place the nanoha-chitosancollagen mixture coated screw. muscles sutured by absorbable catgut suture, while skin sutured j bagh college dentistry vol. 29(2), june 2017 mechanical evaluation restorative dentistry 44 by silk suture. after suturing local antibiotic (oxytetracycline spray) applied to surgical site, and systemic antibiotic was also given. rabbits remain under cover of antibiotic (local and systemic) for three days after operation. after specific period of time the rabbits anesthetized with ketamine hydrochloride (1ml/1kg body weight) and xylocaine 2 %( 1ml/1kg body weight) the stability was accomplished by placing the torque meter into the slit in the head of implants to determine amount of torque required for removing the screws to assess implant-bone contact. mechanical testing removal torque test used to determine amount of force required to remove implanted screws after different period of healing by using of torque meter (sturtevant richmont torque product, model f 80-1-0. usa. 0-80 inch. ounces, with accuracy ±2%). the removal torque value was expressed in newton centimeter (n.cm). results ftir analysis result of ftir of nanohyroxyapatite (figure3) was showed spectra at 565,598,980,1063cm1correspond to po4-3 of ha, peak at 1452cm1correspond to co3 of ha (11, 12). band at 1637 due to absorbed water. while ftir of nano ha-chitosan-collagen mixture (figure 4) was showed shifting of po4-3 group of ha into 569,604 and 1051. spectra at 1240, 1556 and 1645 correspond to amide iii,ii,i respectively of collagen (13)…while band at 2924 belong to asymmetric stretching of ch3 of chitosan (14).and band at 3388cm-1 was belong to nh group stretching vibration of chitosan (15). (figure 4): ftir of nano ha-chitosan-collagen mixture coating (figure3): ftir of nano ha j bagh college dentistry vol. 29(2), june 2017 mechanical evaluation restorative dentistry 45 scanning electron microscope (sem) sem images of nanohyroxyapatite coating (figure 5) and nanohyroxyapatite, chitosan and collagen composite coating (figure 6). it shows uniform coating with particle size of about 200nm in size. (a) 100µm (b) 50 µm (c) 200nm (figure5 a, b, c): sem of nano ha coating at different magnifications. (a)100µm (b) 50µm (c) 200nm (figure 6 a, b, c): sem of nano hachitosan-collagen composite coating at different magnifications. mechanical test table (1) show the summary statistics of the removal torque value of cpti coated implants (mean, minimum and maximum values) for both groups (control and experimental groups) for different period of healing. while (figure 7) show a comparison between the means of coating material at 2 periods of healing. after two weeks of healing period, the torque value that needed to remove implants coated with nano hydroxyapatite, chitosan and collagen composite was higher than the torque value of nano hydroxyapatite coated implants. mean of removal torque values of implants coated with nanoha was (13.76 n.cm), while removal torque mean of composite coating implants was (22.945n.cm). after six weeks of implantation there was increase in removal torque values for both groups, the mean of removal torque values of nano ha coated implants was (22.67 n.cm),and removal torque mean of composite coating group was (31.18n.cm). j bagh college dentistry vol. 29(2), june 2017 mechanical evaluation restorative dentistry 46 table (1): summery statistic of removal torque mean (n.cm) of groups for both periods group no mean min. max. nanoha (2weeks) 6 13.76 10.59 17.65 nanohachitosancollagen (2weeks) 6 22.945 17.56 28.24 nanoha (6weeks) 6 22.67 17.65 28.24 nanohachitosancollagen (6weeks) 6 31.18 28.24 35.30 (figure 7): bar chart of summery of differences in the removal torque means values between all groups. the equality of means between all groups of implant tested were analyzed by anova table. this test demonstrated a highly significance difference for both groups at different period of healing (2 and 6weeks), as in table (2). table (2): equality of removal torque mean of all tested groups after 2 and 6 weeks of implantation by anova test groups sum of squares df mean square f sig. between groups within groups total 914.083 267.501 1181.584 3 20 23 304.694 13.375 22.781 .000  p ≤ 0.05 significant  p ≤ 0.01 highly significant  p ˃0.05 non significant for multiple comparison, the least significant difference (lsd) test used for equality of torque mean values among different groups after 2and 6weeks healing periods. tab.(3) showed a highly significant difference between groups except nano ha, chitosan and collagen composite coating group at two weeks compared with nano ha coating group at 6wweks of healing period. table (3): multiple comparison (lsd) among all groups of different periods of healing group mean difference sig. nano ha (2weeks) nanoha +chi.+c. (2weeks) -9.178 .000 nano ha (6weeks) -8.001 .001 nanoha +chi.+c. (6weeks) -17.415 .000 nanoha +chi.+c. (2weeks nano ha (6weeks) 1.176 .57 nanoha +chi.+c. (6weeks -8.23 0.001 nano ha (6weeks) nanoha +chi.+c. (6weeks) -9.413 0.000  p ≤ 0.05 significant  p ≤ 0.01 highly significant  p ˃ 0.05 non significant j bagh college dentistry vol. 29(2), june 2017 mechanical evaluation restorative dentistry 47 discussions many studies have concentrated on surface characteristics and chemical composition to control bone healing around dental implants (16). dip-coating is an alternative method for prosthetic devices used in orthopedics, it offers a number of advantages over other coating methods such as flexibility, control of coating morphology, chemistry and structure (17). hydroxyapatite demonstrates the best bioactivity amongst all the forms of calcium phosphate (18) chitosan has a set of many characteristic which makes it an excellent choice to be used in tissue regeneration purposes (19). it has greater effect on biological functions of a cell (cell survival, proliferation and differentiation), helps in healing of damaged bones or blood vessels and maintains structural integrity (20). ftir analysis the result of ftir spectra for nanoha and mixture of nanoha-chitosan-collagen recorded changes as the shifting of some vibration peaks and change in appearance and intensity. this could be due to molecular interaction between the end group or functional groups of collagen, nanoha and chitosan (21). this interaction explain the difference in mechanical force required to remove screws from bone. scanning electron microscope (sem) sem images of nanohyroxyapatite show uniform, homogenous and without cracking coating over ti substrate with nanoflower aggregation of particles and nano particle about 200nm. while sem of nanohyroxyapatite, chitosan and collagen composite coating show uniform coating, crack free and aggregation of particles without formation of phase separation. this mean that organic and inorganic material was mixed well and the inorganic particles is too small this agreed (regardless the difference in material and techniques used) with result of wang (22) . mechanical test the mean torque value (n.cm) of nanohachitosan-collagen composite was higher than torque value of nanoha only, it could be rapid new bone formation around implanted screw. the force required to unscrew the implants has been related with the amount of bone in contact with the implant, many studies stated that the changes in the biomechanical features of the implant surface can influence on bone healing and remodeling process (23). the removal torque values was used in present study as a method to detect the presence of osseointegration at boneimplant contact. due to bone remodeling and gradual bone formation at bone-implant interface, the present study show that there was an increase in the removal torque value with time and this agreed with clokie and bell (24). conclusion in conclusion; 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86(11):2526-40. 20. aiman omar mahmoud abbas. chitosan for biomedical applications. a phd thesis, college of pharmacology, university of lowa, usa, 2010. 21. buehler, mj. nature designs tough collagen: explaining the nanostructure of collagen fibrils. pnas. 2006; 103 (33): 12285-12290. 22. xiaoliang wang, xudong li ,xiaomin wang ,jian lu , huichuan zhao, xingdong zhang and zhongwei gu: investigation of a collagen-chitosanhydroxyapatite system for novel bone substitutes. key engineering materials, 2007;330:415-418. 23. faeda rs, tavares hs, sartori r, guastaldi ac, marcantonio e. evaluation of titanium implants with surface modification by laser beam. biomechanical study in rabbit tibias. brazilian oral research 2009; 23(2): 137-43. 24. clokie cm, bell rc recombinant human transforming growth factor beta-1 and its effects on osseointegration. j craniofac surg 2003; 14(3):268 277. nibal final.doc j bagh college dentistry vol. 26(3), september 2014 caries severity in orthodontics, pedodontics and preventive dentistry 164 caries severity in relation to oral health knowledge and behavior of third and fifth year dental students / university of baghdad (a comparative study) nibal m. hoobi, b.d.s., m.sc. (1) abstract background: the knowledge of dental students is important because these individuals are the future dental health providers. the purpose of the present study was to explore the severity of dental caries in relation to oral health knowledge and behavior between two different grades of undergraduate dental students in the college of dentistry / university of baghdad. materials and methods: one hundred dental students were included in this study (50 third years and 50 fifth year students). a questionnaire was distributed among them to evaluate their oral health knowledge and behavior. dental students were examined for recording of dental caries severity. results: data analysis revealed that third year dental students had higher mean of decayed surfaces (ds) and missing surfaces (ms), compared to the other group, the difference was statistically highly significant (p<0.01) for ds and significant for ms (p<0.05), while fifth year dental students were found to have higher mean value of filled surfaces (fs) and the difference was highly significant (p<0.01). however, higher dmfs value was recorded for final year students without any significant difference. oral health knowledge was better for fifth grade and the difference was highly significant (p<0.01) except for the question about complete removal of dental plaque by brushing only, the difference was significant (p<0.05) .oral health behavior of third grade students was at lower level, the difference was highly significant (p<0.01) except for the questions about frequency of brushing and sweet eating, it was significant (p<0.05) and it was not significant difference regarding use of siwak. conclusion: the findings of this study highlights that increase the theoretical education of dental students in addition to clinical experience will improve their oral health knowledge and behavior, which in turn affect positively the oral hygiene towards health promotion and prevention of oral diseases. key words: caries severity, knowledge, behavior. (j bagh coll dentistry 2014; 26(3):164-168). :الخالصھ جامعة بغداد شملت ھذه /فم و السلوك بین مرحلتین مختلفتین من طالب كلیة طب االسنان كا ن الغرض من ھذه الدراسھ ھو معرفة مدى شدة تسوس االسنان وعالقتھا بمعرفة صحة ال وقد تم توزیع استبیان مكون من مجموعة اسئلھ فیما بینھم لتقییم معرفتھم بصحة الفم ).خمسون طالب من المرحلھ الثالثھ وخمسون طالب من المرحلھ الخامسھ(الدراسھ مائة طالب وكشف تحلیل البیانات ان طالب المرحلھ الثالثھ لدیھم متوسط اعلى من االسطح المتسوسھ واالسطح المفقوده وكان الفرق .لى فحص شدة التسوس لھؤالء الطالبوالسلوك باالضافھ ا ن الفرق احصائیا معنویھ عالیھ وسجلت قیمھ اعلى احصائیا معنویھ عالیھ لالسطح المتسوسھ في حین كان طالب السنھ الخامسھ لدیھم قیمھ اعلى لسطوح االسنان التي تم عالجھا وكا اوضحت .كانت معرفة صحة الفم والسلوك الصحي افضل للمرحلھ الخامسھ.لمجموع االسطح المتسوسھ والمفقوده والمعالجھ لطالب المرحلھ الخامسھ وكان الفرق احصائیا غیرمعنوي ضافھ الى الخبره السریریھ ادت الى تحسین معرفتھم بصحة الفم والسلوك وھذا بدوره اثر ایجابیا على العنایھ بالفم نحو ھذه الدراسھ ان التعلیم النظري لطالب المرحلھ الخامسھ باال .تعزیز الصحھ والوقایھ من االمراض introduction knowledge is defined as the expertise and skills acquired by a person through experience or education. knowledge acquisition involves complex cognitive process: perception, learning, communication, association and reasoning (1). undoubtly one of the methods for prevention is to improve the knowledge of the community regarding promotion of health behavior and influence of self effective methods on preventing diseases (2). health behavior is the human action taken to maintain and promote health; it also helps prevent diseases (3). in dentistry, dental caries is the most prevalent disease and the major reason for tooth loss, representing a major challenge for oral health care (4). some components of caries process act at the tooth surface (saliva, biofilm, diet), while another set of determinants which affect the prevalence and severity of dental caries includes (behavior, knowledge, attitude, education, socioeconomic status, income) (5,6). (1)lecturer. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad, oral health behavior consists of individual and professional care and includes tooth brushing, dental flossing, visiting a dentist and following a proper diet (3). biology, environment, life style, health care organizations and psychology factors are essential components of oral health behavior (7). dental health professionals need to set an example for their patients, family and friends by maintaining good oral health in their own mouth (1). positive attitudes toward health promotion need to be developed during student's days rather than afterward (8). the prevalence of caries is declining in developed countries, increasing in less developed countries and is an epidemic in countries with emerging economics (9). decline in the prevalence in developed countries has been associated with improved oral hygiene behaviors and several preventive programs, unlike developing countries where the focus is mostly on curative care (10). there are many studies reported an increase in the prevalence and severity of dental caries among iraqi population (11-13). as there is no published j bagh college dentistry vol. 26(3), september 2014 caries severity in orthodontics, pedodontics and preventive dentistry 165 data available about severity of dental caries among dental students in relation to their knowledge and behavior and as an important group to be a future dental services providers, so this study was designed to assess and compare the impact of course content and contribution of clinical training on the development of their oral health knowledge and behavior and in turn how can these effect severity of dental caries. materials and methods in this study the data was collected from 50 third grade (27 females (54%) and 23 males (46%)) and 50 fifth grade (29 females (58%) and 21 males (42%)) dental students of college of dentistry / baghdad university. the questionnaire included 18 items of three aspects (first), general questions related to the name age, gender and general health, (second) information about oral health knowledge and (third) information concerning their oral health behavior. the assessment of participants' oral health knowledge was done by asking about diet, caries etiology, progression, treatment and its prevention. oral health behavior was assessed by asking about tooth brushing, use of other oral hygiene aids like dental floss, mouth wash and siwak, frequency of visiting a dentist and sweet consumption times. the students were asked to respond to each item according to the response format provided in the questionnaire which included multiple choice questions in which the students were instructed to choose only one response from provided list of options. a full explanation of how to fill in the questions was elucidated to the participants. they filled in the questions without conferring with each other. severity of dental caries was assessed using decayed, missing and filled surfaces index of permanent teeth (dmfs) according to criteria described by who (14). the examination was done in the dental clinic on the dental chair under artificial light (dental light) using plane mouth mirror and sickle shaped explorer. the data were analyzed using spss (version 13). the student's ttest and chisquared tests were applied. the significance level (p-value) was set at 0.05. results table (1) reveals the mean dmfs value for the fifth year which was higher than that of third year student with no statistically significant difference. the mean value of decayed surfaces (ds) was higher for third year with statistically highly significant difference; also the mean value of missing surfaces (ms) was higher for third year with statistically significant difference. fifth year students were found to have higher mean values of filled surface (fs) with highly significant difference. after evaluation the answers of the 100 dental students (50 from third year and 50 from fifth year), it was found that only part of third year students thought that candies and caramel cause dental caries, while all of fifth year sample believed that these substances are causative factors of dental caries. lower percentage of third year students knew that soft drinks are harmful to the tooth structure compared to final year students. the caries decreasing effect of fibrous food was known by less number of third year students. it is clear that final year students had a higher proportion of correct answers than third year and the difference was statistically highly significant as shown in table (2). table (3) demonstrates students dental knowledge, less number of third year accepted that brushing alone is insufficient for complete removal of dental plaque, the difference was statistically significant. higher proportion of final year students compared to third year students thought that filling is not the only treatment for carious tooth , also agreed with the statement " fluoride is useful in increasing tooth resistance against dental caries" and believed that dental caries can progress and cause pulp death and the difference was statistically highly significant between them. the opinion of final year students on how to prevent caries was promising compared to third year students because most of them awarded that decrease sweet eating, regular brushing, inter-dental aids and use of mouth wash are all effective means of avoiding caries versus lower proportion of third year volunteers accepted with this and the difference between two groups was highly significant. table (4) illustrates oral hygiene behaviors among dental students. significantly more fifth year students brush their teeth at least twice a day compared to third year ones. greater proportion of final year student used dental floss and mouth wash, the difference was statistically highly significant. more fifth year students were recorded to use siwak with no significant difference. for last year dental students, it was obvious that the preventive behavior of visiting the dentist for checking is more frequent than third year colleagues from their answers and the difference was statistically highly significant. table (5) shows that the dietary behavior of fifth year student to minimize the risk of caries challenge was better than that of third year students and this is reflected by less number of the later group compared with the former group j bagh college dentistry vol. 26(3), september 2014 caries severity in orthodontics, pedodontics and preventive dentistry 166 consumed sweets once or no a day between meals, the difference was statistically significant. table 1: mean and standard deviation of decayed surfaces (ds), missing surfaces (ms), filled surfaces (fs) and (dmfs) of third and fifth year dental students variables grade mean ± sd t. test p. value ds 3rd 9.08 2.52 14.26 0.00 ** 5th 3.06 1.59 ms 3rd 0.50 1.51 2.33 0.02 * 5th 0 0 fs 3rd 1.42 1.84 15.36 0.00 ** 5th 8.46 2.66 dmfs 3rd 11 2.68 0.89 ns 5th 11.52 3.13 *significant at p <0.05, **highly significant at p<0.01, df = 98 table 2: dietary knowledge of third and fifth year dental students item description third year fifth year χ 2 value statistical significance level no. % no. % do candies and caramel cause dental caries yes 39 78 50 100 12.36 hs p < 0.01 df = 2 no 7 14 0 0 don't know 4 8 0 0 do soft drinks harm the tooth yes 15 30 41 82 27.44 hs p < 0.01 df = 2 no 20 40 5 10 don't know 15 30 4 8 does eating of fibrous food decrease risk of dental caries yes 21 42 43 86 22.39 hs p < 0.01 df =2 no 8 16 4 8 don't know 21 42 3 6 table 3: dental knowledge of third and fifth year dental students item description third year fifth year χ2 value statistical significance level no. % no. % is brushing enough for total removal of dental plaque yes 9 18 3 6 5.74 sig p< 0.05 df =2 no 39 78 47 94 don't know 2 4 0 0 is filling the only treatment for carious tooth yes 12 24 2 4 10.85 hs p < 0.01 df =2 no 36 72 48 96 don't know 2 4 0 0 is fluoride useful in increasing tooth resistance against dental caries yes 33 66 50 100 20.85 hs p < 0.01 df =2 no 5 10 0 0 don't know 12 24 0 0 can dental caries progress and cause death of the pulp yes 31 62 50 100 23.45 hs p < 0.01 df =2 no 6 12 0 0 don't know 13 26 0 0 typical method of caries prevention decrease sweets eating 3 6 0 0 11.56 hs p < 0.01 df =3 regular brushing and inter dental aids 9 18 1 2 use of mouth wash 0 0 1 2 all the above 38 76 48 96 don't know 0 0 0 0 j bagh college dentistry vol. 26(3), september 2014 caries severity in orthodontics, pedodontics and preventive dentistry 167 table 4: oral hygiene behaviors of third and fifth year dental students item description third year fifth year χ2 value statistical significance level no. % no. % frequency of teeth brushing once a day 8 16 3 6 10.88 sig, p < 0.05 df = 4 twice a day 20 40 27 54 three times a day 13 26 19 38 more than three times a day 1 2 0 0 irregularly 8 16 1 2 use of dental floss yes 24 48 37 74 7.10 hs, p < 0.01 df = 1 no 26 52 13 26 use of mouth wash yes 19 38 35 70 10.3 hs, p < 0.01 df=1 no 31 62 15 30 use of siwak yes 9 18 13 26 0.93 ns, 0.33 df = 1 no 41 82 37 74 frequency of dental visit every one year or less 7 14 23 46 12.19 hs, p < 0.01 df = 1 on need 43 86 27 54 table 5: dietary behavior of third and fifth year dental students regarding the frequency of sweet intake between meals item description third year fifth year χ 2 value statistical significance level no. % no. % frequency of sweet eating between meals one or no 32 64 43 86 6.61 sig p < 0.05 df = 2 two 12 24 4 8 three or more 6 12 3 6 discussion effective teaching is critical for student learning, especially in professional fields such as dentistry and dental hygiene (15). result of the present study showed that fifth year dental students had higher caries severity (dmfs) than their third year colleagues, but the difference was statistically not significant. an interesting result of this study was the higher mean value of decayed surfaces (ds) and missing surfaces (ms) for the third year students and the differences were statistically highly significant for ds and significant for ms while the final year students was found to have higher value of filled surfaces (fs) compared with third year students, the difference was highly significant. this may be attributed to the concept that undergraduate dental education, as generally agreed should be scientifically based clinically relevant and medically informed to create stable health behavior that can overcome differences in personal characteristics which affect behavior other than knowledge like, beliefs, values, influence of family members and friends on the oral health behavior (1,16), therefore a substantial increase in the dental theoretical education in addition to clinical experience of the final year students led to positive changes revealed in the oral health knowledge and behavior among them passing through the undergraduate curriculum from first to final year of dental study, so their preventive behavior was improved towards the maintenance of good oral health status (15) and they were directed towards the restoration of their decayed teeth converting them from d component to f component of the dmfs. in agreement with the results of some previous studies (17,18), this research established that the better oral health knowledge of final year students compared to third year ones had definitely got an impact on their behavior by reduction unhealthy behaviors such as frequency of sugar eating especially between meals and increase healthy behaviors such as regular frequent brushing, flossing and use of mouth wash, use of other aids like siwak was found in low percent of both grades (18% of third year, 26% of fifth year) with statistically not significant difference this may be related to cultural perceptions, familial belief and other life situations (19,20). visiting the dentist for routine checkup was defined as preventive care (1). it was demonstrated that the final year students showed better preventive care behaviors than third year colleagues and this may related to their improved knowledge about preventive dentistry. the result of this study pointed out that preventive dentistry courses should be taught early in the dental curriculum of the pre-clinical years and the instructors must be well trained how to explain concepts and techniques of preventive dentistry clearly at the students level of understanding and how to apply them in the real life towards maintenance of good oral health status overcoming differences in their personal j bagh college dentistry vol. 26(3), september 2014 caries severity in orthodontics, pedodontics and preventive dentistry 168 characteristics and acting as an example for their family and friends. references 1. sharda a, shetty s. a comparative study of oral health knowledge, attitude and behavior of first and final year dental students of udaipur city, rajasthan. j oral health comm dent 2008; 2(3): 46-54. 2. neamatollahi h, ebrahimi m. oral health behavior and its determinants in a group of iranian students. indian j dent res 2010; 21: 84-8. 3. steptoe a, wardle j, vinck j, tuomisto m, holte a, whichstrom l. personality and attitudinal correlates of healthy and unhealthy lifestyles in young adults. psychology and health 1994; 9: 331-43. 4. maltz m, jardim j, alves l. health promotion and dental caries. braz oral res 2010; 24(spec. issi):1825. (ivsl). 5. kidd a, bechal j. essentials of dental caries, the disease and its management. 2nd ed. new york: oxford; 2002. pp. 44-65. 6. griffins sg, griffin p, swann j, zlobin n. new coronal caries in older adults: implication for prevention. j dent res 2005; 84(8):715-20. 7. neamatollahii h, ebrahimi m, talebi m, mana h, kondori k. major difference in oral health knowledge and behavior in group of iranian pre-university student: a cross-sectional study. j oral sci 2011; 53(2):177-184. 8. federation dentaire international. the impact of changing disease trends on dental education and practice. fdi technical report no. 30. int dent j 1987; 37:127-30. 9. lundeen t, roberson t. cariology: the lesion, etiology, prevention and control. in: studervant c, roberson t, heymann h, studeervant j (eds). the art and science of operative dentistry. 3rd ed. singapore: harcourt asia pte ltd.; 1995. pp. 62-3. 10. sheiham a. changing trends in dental caries. int j epidemiol 1984; 13:142-7. 11. al-azawi l. oral health status and treatment needs among iraqi 5 years old kindergarten children and 15 years old students (national survey). ph.d. thesis, college of dentistry, university of baghdad, 2000. 12. ali dn. oral health status and treatment needs among 12 years old school children in urban and rural area of baghdad – iraq. a master thesis, college of dentistry, university of baghdad, 2001. 13. madhat d. oral health status and treatment needs among eighty year old school children in urban and rural areas in baghdad iraq. a master thesis, college of dentistry, university of baghdad, 2002. 14. world health organization. oral health surveys basic methods. 3rd world health organization. geneva, switzerland; 1987. 15. ozalp n, dag c, okte z. oral heath knowledge among dental students. clinic dentistry res 2012; 36(1): 18-24. 16. divaris k, barlow pj, chendea sa, cheong ws, dounis a, dragan if, et al. the academic environment: the students' perspective. eur j dent educ 2008; 12:120-30. (ivsl). 17. tseveenjav b, vehkalahti m, murtomaa h. time and cohort changes in preventive practice among mongolian dental students. eur j dental edu 2003; 7(4): 177-81. 18. ws rong, wj wang, hk yip. attitudes of dental and medical students in their first and final years of undergraduate study to oral health behavior. eur j dental edu 2006; 10(3): 178-84. 19. chen ms. children’s preventive dental behavior in relation to their mother's socioeconomic status, health beliefs, and dental behaviors. j dentistry child 1986; 53:105-9. 20. mccaul kd, glasgow re, gustafson c. predicting levels of preventive dental behaviors. jada 1985; 111: 601-5. j bagh college dentistry vol. 26(1), march 2014 oral cancer oral diagnosis 108 oral cancer awareness among group of general dental practitioners in iraq omar sh. museedi, b.d.s., m.sc. (1) abstract background: the early detection of oral cancers gives the greatest chance of curing and the delay in presentation has a significant impact on the associated morbidity and mortality. the lack of general dental practitioners (gdp) knowledge in early cancer detection has been shown to contribute to delays in referral and treatment. the aim of this study was to investigate the oral cancer awareness among a group of gdp by assessing their knowledge of detection and prevention of oral cancer. materials and methods: a questionnaire based study was designed. the questionnaire was delivered to 200 gdp assessing oral examination method, knowledge of oral cancer risk factors, clinical appearance and the most common site, point of referral and requests for further information. results: a response rate of 69% was obtained. the gdp were less likely to examine the oral mucosa than other similar studies in other countries, and also less likely to advice patient about risk factors. smoking and alcohol use wereidentified as risk factors by 96.3% and 43.48% of the gdp respectively. only 37.7% of gdp believed they had sufficient knowledge of oral cancer, and more than 94% believed they need further information about oral cancer. conclusion: this study highlights need for more education of the gdp on oral cancer. keywords: oral cancer, general dentists, awareness, iraq. (j bagh coll dentistry 2014; 26(1):108-111). introduction in many parts of the world oral cancer is considered a major health problem, especially in the developing countries (1). globally, oral cancer ranks eleventh between the most common cancers, where more than 500,000 patients are estimated to have oral cancer globally and with approximately 389,000 new cases per annum (2). many epidemiological studies have revealed that incidences of oral cancer increased with smoking, alcohol intake and age (3). typically, oral cancers some time take several years to progress to advanced stages; treatment of oral cancer in earlier stage is less complicated with higher survival rate (4). otherwise the advanced stage needed invasive treatment which may lead to poorer quality of life and disfigurement for patients (4). therefore, oral cavity examination of dental patients by inspection and palpitation is essential for early detection of suspected oral cancer. gdp already have easy accessibility to the populations’ of oral cavity; hence they arguably bear the greats share of responsibility in detection and diagnosis of oral cancer (5). so the aim of this study is to assess the level of knowledge, attitudes and behaviors of gdp toward oral cancer. materials andmethods this descriptive cross sectional study was conducted using self-administrated questionnaire, which has been designed and used by carter and ogden (6). the questionnaire was tested on 20 gdp as a pilot study to assess uniformity of interpretation, and there was no major corrections were necessary. the list of gdp was obtained from iraqi dental association. a total of 200 (120 males / 80 females) gdp, working in different iraqi provinces, were (1)assistant lecturer. department of oral diagnosis. college of dentistry. university of baghdad. selected to participate in the study. the gdp received the questionnaire through their personal email and were kindly asked to return the filled questionnaire in 14 days. ten questions were designedto investigate whether the gdp screen the oral mucosa during routine examination, especially if patient was at high risk to oral cancer. the questionnaire also assess the dentists knowledge about the risk factors for oral cancer, and if they educate their patients about such factors. the questionnaire also designed to assess the gdp knowledge regarding the different clinicalappearance, the associated changesof oral cancer and the most common sites for oral cancer. the questions also screened the gdp point of view regarding referring the suspected oral cancer patient and their opinion about the sufficiency of their individual knowledge on oral cancer detection, and prevention and if they need information further information regarding oral cancer. the questionnaire estimated to require approximately 10 minutes to be completed. results the questionnaire was returned by 143 gdp, five of them uncompleted, hence were excluded from the analysis. finally, the total of accepted questionnaires was 138 which represented 69% from the sent questionnaires. the characteristic of participated gdp is shown the table1. only 80 (57.9%) gdp reported that they routinely examine oral mucosa of their patients, while 8 (5.8%) only screen mucosa if the patient was of the cancer risk group (table 2). when asked the dentists “what would you considered as a risk factors for oral cancer” in open question, which provided wide range of responses, therefore responses in relation was merged groups of responses and the details are shown in the table 3. j bagh college dentistry vol. 26(1), march 2014 oral cancer oral diagnosis 109 smoking 96.3% (133), dental factors 94.2% (132) and alcohol 43.48% (60) were identified as the most frequent risk factor and only 3% (5) identified consumption alcohol and smoking together was more high risky. the details are shown in the fig.1. in this study, 50 (36.2%) advice the patient about the risk factor and 62.3% (86) of dentists felt unconfident about diagnosis oral cancer appearance. the answer to the open question “what changes within the mouth could be associated with oral cancer” ulceration 73.9%, mass 38.4% and leukoplakia 20.3% was the frequent answers, figure 2 shows the answers to this question. another open question “where do you think most common sites for oral cancer” 71% answered the lateral side of the tongue the most common site and the details of answers are seen in the fig.3 about 76.1% preferred to refer the patient to maxillofacial surgery while 94.2% (130) like more training and information about oral cancer and most of them prefer continuous education program. discussion this study was the first study to assess oral cancer awareness among iraqi dentists. this study used three open ended questions to evaluate knowledge regarding oral cancer risk factors, appearance and site. the number of questions was kept to a minimum to encourage the responses and appeared to work well when previously employed. a total of 57.9% of the sample routinely examines patients’ oral mucosa. screening the oral mucosa was lower than found in similar studies on general dentist and student in uk (6,7). from participants who declared that they don’t screen patients’ oral mucosa 13.7% only screened the mucosa of risky patient and this also was lower than previous mentioned studies. smoking as a risk factor was well identified from the responder, which most reports clearly established a direct causal relationship between cigarette smoking and cancer of oral cavity (8), whereas alcohol was poorly identified as a risk factor. in spite of the strong relationship between oral cancer and alcohol consumption (9), thus the role of alcohol as a risk factor for oral cancer has to be emphasis in future. the combination of smoking and alcohol consumption exert a synergistic effect that substantially increases the risk factor (10). the priority to dental factors that gave from responder as a risk factor but there little evidence suggest that poor oral hygiene, improper fitting denture border misaligned or sharp teeth (11,12). dentist mostly identified ulceration and mass as oral changes. these results do not coincide with previous study in uk and canada (6,7,13). the ulceration was well indicated by the dentists, but erythroplakia and erythroleukoplakia were not well indefinite in spite of the malignant transformation rate of erythroplakia and erythroleukoplakia which could be at least 50% (14). the level of knowledge towards leukoplakia has slightly higher than erythroplakia but still under than that required. it is well known that leukoplakia has less malignant potential than erythroplakia; however nonhomogenous, speckled and nodular types of leukoplakia can have similar rates of malignant transformation compared with erythroplakia(15).the lateral border of tongue and floor the mouth were the most common sites mostly identified by the responders. actually the epidemiological studies have shown that the sites of occurrence for oral cancer differ widely, but the tongue, lip, and floor of the mouth are the most frequent sites of squamous cell carcinoma in the oral cavity(16). fewer dentists believed they had sufficient knowledge regarding oral cancer prevention and detection. more than 94% of the dentists needed more information regarding oral cancer, which is almost similar to the results of previous studies in uk (6, 7). this study showed poor level of awareness among the gdp regarding oral cancer. therefore, extensive continuous education programs in oral cancer arenecessary in iraq to increase the level of awareness about oral cancer for gdps. references 1. uti og, fashina aa. oral cancer education in dental schools: knowledge and experience of nigerian undergraduate students. j dent edu 2006; 70: 676-80. 2. stewart bw, kleihues p. world cancer report. iarc, lyon 2003. 3. znaor a, brennan p, gajalakshmi v, mathew a, shanta v, varghese c, et al. independent and combined effects of tobacco smoking, chewing and alcohol drinking on the risk of oral, pharyngeal and esophageal cancers in indian men. int j cancer 2003; 105: 681-6. 4. zavras a, andreopoulus n, katsikeris n, zavras d, cartsos v, vamvakidis a. oral cancer treatment costs in greece and the effect of advanced disease. bmc public health 2002; 2: 12 5. sciubba jj. oral cancer and its detection, historytaking and the diagnostic phase of management. j am dent assoc 2001;132(suppl):12s-18s 6. carter lm, ogden gr. oral cancer awareness of general medical and general dental practitioners. br dent j 2007; 203(5): 248-9. 7. carter lm, ogden gr. oral cancer awareness of undergraduate medical and dental students. bmc med educ 2007; 7: 44. 8. blot wj, mclaughlin jk, winn dm, et al. smoking and drinking in relation to oral and pharyngeal cancer. cancer res 1988; 48: 3282-7. 9. mashberg a, garfinkel l, harris s. alcohol as a primary risk factor in oral squamous carcinoma. ca cancer j clin 1981; 31: 146-55. j bagh college dentistry vol. 26(1), march 2014 oral cancer oral diagnosis 110 10. franceschi s, talamini r, barra s, et al. smoking and drinking in relation to cancers of the oral cavity, pharynx, larynx, and esophagus in northern italy. cancer res 1990; 50: 6502-7. 11. silverman sj, shillitoe ej. etiology and predisposing factors. in: silverman sj, ed. oral cancer. atlanta: american cancer society 1990: 7-39. 12. gorsky m, silverman s jr. denture wearing and oral cancer. j prosthet dent 1984; 52:164-70. 13. clovis jb, horowitz am, poel dh. oral and pharyngeal cancer: practices and opinions of dentists in british columbia and nova scotia. j can dent assoc 2002; 68:421-5. 14. bouquot je, ephros h. erythroplakia: the dangerous red mucosa. pract periodontics aesthet dent 1995; 7: 59-67. 15. axell t, pindborg jj, smith cj, van der waal i. oral white lesions with special reference to precancerous and tobacco-related lesions: conclusions of an international symposium held in uppsala, sweden, may 18-21, 1994. j oral pathol med 1996; 25: 49-54. 16. silverman s jr, gorsky m. epidemiologic and demographic update in oral cancer: california and national data 1973 to 1985. j am dent assoc 1990; 120: 495-9. table1: demographic and practice characteristic of respondents characteristic n % mean± sd gender 138 male 80 58% female 58 42% age 138 35.18± 9.188 male 80 34.86± 9.385 female 58 35.62± 8.973 year of graduation 1971-1975 3 2.17% 1976-1980 4 2.90% 1981-1985 3 2.17% 1986-1990 15 10.87% 1991-1995 13 9.42% 1996-2000 17 12.32% 2001-2005 39 28.26% 2006-2010 26 18.84% 201118 13.04% region of work baghdad 72 52.17% kurdistan region 14 10.14% south of iraq 14 10.14% west of iraq 18 13.04% middle euphrates region 20 14.49% table 2: distribution of response to question questions yes no total male female total male female do you examine patients' oral mucosa routinely? 106 (76.8%) 65 (81.3%) 41 (70.7%) 32 (23.2%) 15 (18.7%) 17 (29.3%) do you inform your patients about the risk factors for oral cancer? 50 (36.2%) 31 (38.8%) 19 (32.8%) 88 (63.8%) 49 (61.2%) 39 (67.2%) do you feel that you have sufficient knowledge concerned with detection and prevention of oral cancer? 52 (37.6%) 27 (33.8%) 25 (43.1%) 86 (62.4%) 53 (66.2%) 33 (56.9%) would you like more information or training on oral cancer? 130 (94.2%) 74 (92.5%) 56 (96.6%) 8 (5.8%) 6 (7.5%) 2 (3.4%) j bagh college dentistry vol. 26(1), march 2014 oral cancer oral diagnosis 111 table 3: risk factors for oral cancer 0 10 20 30 40 50 60 70 80 90 100 % risk factor figure 1: distribution of risk factors identified figure 2: distribution of oral changes identified 0 20 40 60 % site figure 3: distributions of most common site smoking alcohol uv light exposure human papilloma virus dental factor: sharp tooth or filling bad oral hygiene ill-fitted denture dietary factor: vitamin deficiency spicy food high fat diet j bagh college dentistry vol. 28(4), december 2016 assessment of oral and maxillofacial surgery and periodontics 115 assessment of salivary α-amylase and flow rate levels and their correlation with gingivitis and severity of chronic periodontitis (part: 1) haider j. talib, b.d.s. (a) maha a. ahmed, b.d.s., m.sc. (b) abstract background: periodontal diseases are bacterial infections of the gingiva, bone and attachment fibers that support the teeth and hold them in the jaw. α-amylase is an enzyme, produced mainly by parotid gland and it seems to play a role in maintaining mucosal immunity. aims of the study: determine the salivary levels of α-amylase and flow rate and their correlations with clinical periodontal parameters(plaque index , gingival index , bleeding on probing , probing pocket depth , and clinical attachment level ) and the correlation between α-amylase with flow rate of study groups that consist of ( patients had gingivitis and patients had chronic periodontitis with different severities(mild ,moderate ,severe) and control group . materials and methods: salivary α-amylase and flow rate levels with clinical periodontal parameters(plaque index , gingival index , bleeding on probing , probing pocket depth , and clinical attachment level ) were measured from 75 males , age ranged (30-45) years old, that divided into study groups(group of 45chronic periodontitis patients with different severities which sub-grouped into (mild=15, moderate=15 and severe=15), group of 15 patients with gingivitis) and control group comprised 15 subjects had clinically healthy periodontium. results: the levels of salivary α-amylase in patients had chronic periodontitis were the highest followed by patients had gingivitis .highly significant differences were demonstrated between each pairs of chronic periodontitis subgroups hence, the highest level at severe chronic periodontitis subgroup patients. flow rate decreased in gingivitis group and chronic periodontitis with its different severities. highly significant strong positive correlations were found between α-amylase with clinical periodontal parameters at all groups and subgroups. conclusions: the findings of the present study suggest that salivary α-amylase can help to monitor the progression of the periodontal disease. keywords: gingivitis, chronic periodontitis, α-amylase, saliva, flow rate. (j bagh coll dentistry 2016; 28(4):115-121) introduction periodontal diseases (pd) are bacterial infections of the gingiva, bone and attachment fibers that support the teeth and hold them in the jaw (1) . the two common forms of periodontal diseases are gingivitis and periodontitis. gingivitis is a reversible inflammatory condition of the soft tissue surrounding the teeth (the gingiva) without the involvement of the attachment apparatus, whereas periodontitis involves the deeper periodontium resulting in the clinical attachment loss with the destruction of gingiva, periodontal ligament, cementum and alveolar bone (2,3). regrettably, the resulting tissue damage is irreversible and it is usually asymptomatic until teeth become loose (4,5). chronic periodontitis (cp) is very common disease and it is generally a slowly progressing form of pd, but may have periods of rapid progression (6,7). saliva is a unique complex, important body fluid (8-10). salivary sample, since it is a simple, non-invasive and safer method, besides; its storage is simple and cost-efficient. saliva contains locally produced microbial and host response mediators, as well as, systemic (serum) markers (11). (a) m.sc. student, department of periodontics, college of dentistry, university of baghdad. (b) assistant professor, department of periodontics, college of dentistry, university of baghdad. salivary flow rate (fr), it is the amount of saliva naturally produced by the salivary glands. in adults, normal total (fr) up to 3 ml/min (12-14) hence, decreased in patients with cp ( 15). the α-amylase is an enzyme, produced mainly by parotid gland, which primary function in saliva is to break down high molecular weight carbohydrates to lower molecular weight sugars (i.e., glucose) (16). in addition, amylase seems to play a role in maintaining mucosal immunity (16,17). hence, such salivary marker (α-amylase) and flow rate can help to enhance oral defense mechanism. due to these detectable issues, this study was conducted to find the correlation between salivary levels of α-amylase and flow rate with severity of pds. materials and methods the human sample included 75 males age range from (30-45) years old. subjects recruited for this study were from the department of periodontics at the teaching hospital of college of dentistry, university of baghdad as well as from blood bank in baghdad. from each subject, unstimulated whole saliva sample was harvested, then the amount of saliva in (ml), divided by the time (min) of duration of the collection was recorded as the salivary flow rate, then each sample centrifuged at 3000 rpm for j bagh college dentistry vol. 28(4), december 2016 assessment of oral and maxillofacial surgery and periodontics 116 10 minutes in the poisons center in ghazy alharery hospital, then the clear supernatant saliva was collected by micropipette into eppendrof tubes and store at -20 ˚c until biochemical analysis of α-amylase. full examinations of clinical periodontal parameters were carried out. 1. assessment of soft deposits by plaque index system (pli) (18). 2. assessment of gingival inflammation by the gingival index system (gi) (19). 3. assessment of gingival bleeding on probing (bop) (20). 4. assessment of probing pocket depth (ppd) (20). 5. assessment of clinical attachment level (cal) (21). according to this examination, the subjects generally were divided into three main groups: 1. chronic periodontitis (cp) group: consisted of (45) males had chronic periodontitis. this was defined by the presence of at least four sites with ppd ≥ 4mm and clinical attachment loss of (1-2 mm) or more (22).patients in this group subdivided into three subgroups according to the severity of clinical attachment loss (21) into: mild cp: consisted of 15 males with clinical attachment loss of 1-2mm. moderate cp: consisted of 15 males with clinical attachment loss of 3-4mm. severe cp: consisted of 15 males with clinical attachment loss of (≥5mm). 2. gingivitis group: consisted of (15) males had gingivitis, this was defined by the presence of signs and symptoms of gingival inflammation and without periodontal pocket or clinical attachment loss. 3. control group: consisted of (15) males with clinically healthy periodontium, this was defined by the absence of any signs and symptoms of gingival inflammation and without periodontal pocket or clinical attachment loss. this group presents a baseline data for the levels of salivary α-amylase. the inclusion criteria were apparently systemically healthy subjects or patients and at least 20 teeth present. the exclusion criteria were females, smokers, alcohol drinkers, patients undergone periodontal treatment and /or used a course of antiinflammatory, antimicrobial or other medications in the 3 months before the study and presence of systemic disease ,e.g. diabetes mellitus, cardiovascular disease, rheumatoid arthritis ..etc. for α-amylase enzyme analysis we used kit manufactured by biosystems (spain), the kit subjected to modification by a specialist (biochemist) in the laboratories of the poisons center of the specialized surgeries hospital to measure the activity of this enzyme in saliva. descriptive statistics in the form of means, standard deviation (s.d.) and inferential statistics in the form of one-way anova test, lsd test and pearson's correlation coefficient test (r) were used in this study. in the statistical evaluation, the following levels of significance (sig.) were used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant we certify that this study involving human subjects is in accordance with the helsinki declaration of 1975 as revised in 2000 and that it has been approved by the relevant institutional ethical committee. results the mean values of age for control, gingivitis and chronic periodontitis groups were (37.33, 37.47, 37.29) respectively, and these values convergent to each other. the pli and gi demonstrated the highest mean values in cp group followed by gingivitis group and lastly the control group, hence the same result was revealed about bop score1. in addition to that the severe cp subgroup presented the highest mean values among the cp subgroups followed by moderate cp subgroup and lastly the mild cp subgroup showed the minimum mean values with highly significant statistical differences were observed among the cp subgroups about all clinical periodontal parameters (table-1). from table -2, comparisons regarding all clinical periodontal parameters revealed highly significant differences between all pairs of cp subgroups with (p-value ≤ 0.001) as well as comparisons of mean values of pli ,gi,bop score 1 showed that there were highly significant differences between the gingivitis group with each one of cp subgroups with p-value ≤ 0.001. in table -3, the biochemical analysis of salivary α-amylase level revealed that cp group presented the highest mean value (100475.18) followed by gingivitis group (51369.27) and lastly the control group showed the minimum mean value (17403.27). while severe cp subgroup presented the highest mean value j bagh college dentistry vol. 28(4), december 2016 assessment of oral and maxillofacial surgery and periodontics 117 (121266.20) among the cp subgroups followed by moderate cp subgroup (101700.40) then the mild cp subgroup (78458.93). a highly significant statistical difference was observed among the cp subgroups with (p-value≤ 0.000). on the other hand, physical parameter analysis showed decrease in mean values of fr in gingivitis and cp groups as compared to control group .in addition to that the mild cp subgroup presented the highest mean value (0.85) among the cp subgroups followed by moderate cp subgroup (0.65) and the severe cp subgroup showed the minimum mean value (0.38). a gain a highly significant statistical difference was observed among the cp subgroups with (p-value ≤ 0.001). regarding salivary α– amylase and fr, highly significant differences were revealed between all pairs of cp subgroups and between each one of cp subgroups with gingivitis and control groups as well as both groups with each other (table-4). the results of correlations (table-5) between mean values of pli and gi for control, gingivitis and cp groups and cp subgroups with the αamylase levels were highly significant strong positive correlations. the correlations between mean values of bop score 1,ppd,cal of cp group and cp subgroups with the α-amylase were highly significant strong positive , the same result was revealed between mean values of bop score 1 of gingivitis group with the α-amylase. the correlations between mean values of salivary fr for control, gingivitis and cp groups and cp subgroups with the α-amylase were highly significant strong negative. from table-6), the correlations between fr with clinical periodontal parameters were almost highly significant strong negative at control, gingivitis and cp groups and cp subgroups. table 1: descriptive statistics of clinical periodontal parameters for groups and subgroups with difference among cp subgroups groups and subgroups pli gi bop score 1 ppd cal mean ±s.d. mean ±s.d. mean ٪ ±s.d mean ±s.d. mean ±s.d. control 0.46 0.07 0.35 0.07 gingivitis 1.47 0.05 1.37 0.03 30.08 1.90 cp 2.16 0.34 2.04 0.33 69.17 13.79 2.707 1.885 3.83311 2.026 mild 1.80 0.05 1.69 0.06 54.75 2.20 0.60 0.06 1.61 0.07 moderate 2.08 0.09 1.96 0.07 65.52 2.15 2.39 0.11 3.42 0.15 severe 2.59 0.09 2.47 0.08 87.26 0.82 5.13 0.16 6.46 0.18 f-test among cp subgroups 365.027 494.602 1214.023 5748.496 4425.816 p-value sig. 0.000 ( hs) 0.000 ( hs) 0.000 ( hs) 0.000 ( hs) 0.000 ( hs) table 2: mean differences of the clinical periodontal parameters between all pairs of cp subgroups and with gingivitis group. gingivitis group and cp subgroups pli gi bop score 1 ppd cal mean difference pvalue sig. mean difference pvalue sig. mean difference pvalue sig. mean difference pvalue sig. mean difference pvalue sig. mild moderate -0.28 0.000 hs -0.27 0.000 hs -10.77 0.000 hs -1.79 0.000 hs -1.81 0.000 hs severe -0.79 0.000 hs -0.78 0.000 hs -32.51 0.000 hs -4.53 0.000 hs -4.85 0.000 hs moderate severe -0.51 0.000 hs -0.51 0.000 hs -21.74 0.000 hs -2.74 0.000 hs -3.04 0.000 hs gingivitis mild -0.33 0.000 hs -0.32 0.000 hs -24.67 0.000 hs moderate -0.61 0.000 hs -0.59 0.000 hs -35.44 0.000 hs severe -1.12 0.000 hs -1.10 0.000 hs -57.18 0.000 hs j bagh college dentistry vol. 28(4), december 2016 assessment of oral and maxillofacial surgery and periodontics 118 table 3: descriptive statistics of salivary α– amylase concentrations (u ̸ l) and fr (ml/min) for groups and subgroups with difference among cp subgroups groups and subgroups α – amylase fr mean ±s.d. f-test p-value sig. mean ±s.d. f-test p-value sig. control 17403.27 2227.88 1.34 0.11 gingivitis 51369.27 5802.99 1.05 0.04 cp 100475.18 18175.21 0.63 0.20 mild 78458.93 4985.51 381.874 0.000 hs 0.85 0.04 213.713 0.000 hs moderate 101700.40 4957.75 0.65 0.04 severe 121266.20 2163.88 0.38 0.09 table 4: mean differences of salivary α-amylase and fr between all pairs of groups and subgroups. groups and subgroups α-amylase fr mean difference p-value sig. mean difference p-value sig. mild moderate -23241.47 0.000 (hs) 0.20 0.000 (hs) severe -42807.27 0.000 (hs) 0.47 0.000 (hs) moderate severe -19565.80 0.000 (hs) 0.27 0.000 (hs) control gingivitis -33966.00 0.000 (hs) 0.29 0.000 (hs) mild -61055.66 0.000 (hs) 0.49 0.000 (hs) moderate -84297.13 0.000 (hs) 0.69 0.000 (hs) severe -103862.93 0.000 (hs) 0.96 0.000 (hs) gingivitis mild -27089.66 0.000 (hs) 0.20 0.000 (hs) moderate -50331.13 0.000 (hs) 0.40 0.000 (hs) severe -69896.93 0.000 (hs) 0.67 0.000 (hs) table 5: correlations between the levels of salivary α-amylase with the clinical parameters of groups and subgroups parameters statistical analysis control gingivitis cp mild moderate severe pli r 0.955 0.985 0.967 0.951 0.938 0.749 p-value 0.000 0.000 0.000 0.000 0.000 0.001 gi r 0.923 0.942 0.966 0.945 0.841 0.853 p-value 0.000 0.000 0.000 0.000 0.000 0.000 bop score 1 r 0.950 0.962 0.765 0.951 0.727 p-value 0.000 0.000 0.001 0.000 0.002 ppd r 0.967 0.902 0.882 0.865 p-value 0.000 0.000 0.000 0.000 cal r 0.965 0.883 0.963 0.855 p-value 0.000 0.000 0.000 0.000 fr r -0.945 -0.956 -0.968 -0.887 -0.904 -0.888 p-value 0.000 0.000 0.000 0.000 0.000 0.000 table 6: correlations between the levels of salivary fr with the clinical periodontal parameters of groups and subgroups parameters statistical analysis control gingivitis cp mild moderate severe pli r -0.934 -0.936 -0.984 -0.911 -0.931 -0.851 p-value 0.000 0.000 0.000 0.000 0.000 0.000 gi r -0.925 -0.891 -0984 -0.952 -0.807 -0.945 p-value 0.000 0.000 0.000 0.000 0.000 0.000 bop score 1 r -0.901 -0.965 -0.691 -0.908 -0.920 p-value 0.000 0.000 0.004 0.000 0.000 ppd r -0.968 -0.858 -0.851 -0.935 p-value 0.000 0.000 0.000 0.000 cal r -0.968 -0.745 -0.939 -0.916 p-value 0.000 0.001 0.000 0.000 j bagh college dentistry vol. 28(4), december 2016 assessment of oral and maxillofacial surgery and periodontics 119 discussion the mean values of age almost convergent to each other nearly 37 years, this might be due to the selective criteria of patient's age of this study which is (30-45). since the pds occur most frequently in patients with older age (23). in the present study there were highly significant differences between the gingivitis group with each one of cp subgroups were demonstrated concerning pli, gi, bop score 1. these were in agreement with the results of other studies (24-27), as well as highly-significant differences among the cp subgroups and between all pairs of subgroups .these findings indicate the effect of plaque accumulation on blood circulation and the actual pathophysiological process that happened more in inflamed tissue and the severity of bleeding with the ease of its provocation depend on the intensity of the inflammation. where more plaque accumulation with increased number of active sites that coincide with severity of cp, cause proliferation of capillaries and increased formation of capillary loops between rete ridges leads to increase vascular permeability and bleeding tendency (3). on the other hand, regarding the ppd and cal highly-significant statistical differences were observed among the cp subgroups and when comparing each two subgroups. hussein and mahmood (27) revealed in their study nonsignificant and highly significant differences among the cp subgroups regarding ppd and cal respectively. this could be due to increase in the amount of plaque and bacterial invasion that caused destruction of the sulcular & junctional epithelium & surrounding alveolar bone. in addition, the early concepts assumed that after the initial bacterial attack, periodontal tissue destruction continued to be linked to bacterial action (3). concerning the α-amylase levels highly significant differences showed among the cp subgroups and in inter subgroups comparisons. on the other hand, comparisons revealed highly significant differences between the control with gingivitis groups, also each of them with each one of cp subgroups. so, increased level of α-amylase with increased severity of pds. these results in accordance with other studies which showed an increase in salivary αamylase levels in patients with gingivitis and chronic periodontitis as compared to control group (15,2830). also in agreement with previous study that was conducted by kejriwal et al. (31) who showed significant increased levels of salivary α-amylase had been found in patients with gingivitis and chronic periodontitis compared to subjects had clinically healthy periodontium. while others found highly significant increase in salivary α-amylase level in cp patients as compared to control group (32,33). thus, increased levels of α-amylase may be due to the response of salivary glands to inflammatory diseases like gingivitis and periodontitis resulting in increased synthesis and secretion of certain acinar proteins like α-amylase so as to enhance the oral defense mechanism (28,34). since, salivary gland secretion is a nerve mediated reflex. amylase is released by exocytosis from salivary cells in response to sympathetic stimulation (35). the infectious process of pds activates the sympathetic system, which in turn leads to the release of some salivary proteins, thereby increasing the protective potential of saliva (15). studies showed that α-amylase is a major lipopolysaccharide binding protein of aggregatibacter actinomycetemcomitans and propheromonas gingivalis and interferes with bacterial adherence and biofilm formation (36,37). also, it was suggested that the amylase help against streptococcal bacterial adherence, which inhibits further propagation on colonization of bacteria and may help regulate normal bacterial flora in the mouth (17). thus, the increase concentration of salivary α-amylase in gingivitis and periodontitis suggests it to be an important defense molecule essential for the innate immunity in the oral cavity (31). the results showed that fr level decreased in gingivitis group and cp group and subgroups with highly significant differences among the cp subgroups and at inter subgroups comparisons. at the same time, highly significant differences between the control with gingivitis groups, also between the control and gingivitis groups with each one of cp subgroups were demonstrated. the decrease in salivary fr of cp group in this study coincide with others (15,33,38). some studies (39,40) detected that in cp patients, there was non significant decrease in the fr while others (23) revealed significant decrease in the fr ,although previous study (32) detected highly significant decrease in the fr but non significant increase in the fr as compared to control group was demonstrated(41). while ,it was found that individuals who have increased salivary inorganic calcium, phosphate, ph, fr with poor oral hygiene could be at a higher risk for developing periodontitis and may have less dental caries and more number of intact teeth (42). j bagh college dentistry vol. 28(4), december 2016 assessment of oral and maxillofacial surgery and periodontics 120 there are multiple causes of salivary hypofunction including inflammation e.g. pds (33), hydrogen concentration in which the higher concentrations of hydrogen ions (from salivary glands or oral microbiota), the lowest the ph, that can be attributed to decrease in fr (38). the correlations between mean values of pli and gi for control, gingivitis and cp groups and cp subgroups with the α-amylase levels were highly significant strong positive correlations . these are explained by the fact that the microbial biofilm is considered the primary and the major etiological factor responsible for initiation of pd (6). thus an increasing in pli cause increase in the severity of gingival inflammation that leads to increase in the level of α-amylase. this is in agreement with other study (31). the correlations between mean values of bop score 1,ppd,cal of cp group and cp subgroups with the α-amylase were highly significant strong positive , the same result was revealed between mean values of bop score 1 of gingivitis group with the α-amylase. these findings can be explained by the fact that increase in severity of inflammation that caused by increase in accumulation of plaque bacteria which demonstrated by increasing in mean values of bop, ppd and clinical attachment loss (20) accompanied by increasing in salivary αamylase level (31). since it was established that the host’s immunoinflammatory response to the initial and persistent bacterial attack unleashes mechanisms that lead to collagen and bone destruction. these mechanisms are related to various cytokines, some produced normally by cells in non-inflamed tissue and others by cells involved in the inflammatory process such as polymorphonuclear leukocytes, monocytes and other cells (20) and this accompanied by increasing in salivary α-amylase level(31). the correlations between mean values of salivary fr for control, gingivitis and cp groups and cp subgroups with the α-amylase were highly significant strong negative. gingivitis and periodontitis induces an increase in the output of total proteins, mucin and αamylase, as a result of responding of salivary glands to inflammatory diseases thereby increasing the protective potential of saliva and this is accompanied by a decrease in flow rate (15,31). sánchez et al. 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23(3): 288-94. 34. sánchez ga, miozza va, delgado a, busch l. relationship between salivary mucin or amylase and the periodontal status. oral dis 2013; 19(6): 585-91. 35. proctor gb, carpenter gh. regulation of salivary gland functions by autonomic nerves. auton neurosci 2007; 133: 3–18 36. choi s, baik je, jeon jh, cho k, seo dg, kum ky, et al. identification of porphyromonas gingivalis lipopolysaccharide-binding proteins in human saliva. mol immunol 2011; 48(15-16): 2207-13. 37. baik je, hong sw, choi s, jeon jh, park oj, cho k, et al. alpha-amylase is a human salivary protein with affinity to lipopolysaccharide of aggregatibacter actinomycetemcomitans. mol oral microbiol 2013; 28(2):142-53. 38. gazy y, mohiadeen b, al-kasab z. assessment of some salivary biochemical parameters in cigarette smokers with chronic periodontitis. j bagh coll dentistry 2014; 26(1):144-9. 39. bezerra aa, pallos d, cortelli jr, saraceni ch, queiroz c. evaluation of organic and inorganic compounds in the saliva of patients with chronic periodontal disease. rev odontosienc 2010; 25: 2348. 40. al-ameer la, ali bgh. effects of smoking on salivary levels of alkaline phosphatase and osteocalcin in chronic periodontitis patients. j bagh coll dentistry 2015; 27(2): 110-4. 41. ali bgh, ali omar h. detection of salivary flow rate and minerals in smokers and non-smokers with chronic periodontitis (clinical and biochemical study). j bagh coll dentistry, 2012; 24(1): 68-71. 42. fiyaz m, ramesh a, ramalingam k, thomas b, shetty s, prakash p. association of salivary calcium, phosphate, ph and flow rate on oral health: a study on 90 subjects. j indian soc periodontol 2013; 17:454-60. j bagh college dentistry vol. 29(1), march 2017 salivary free pedodontics, orthodontics and preventive dentistry 165 salivary free testosterone and gingival health condition among a group of women with polycystic ovary syndrome andalusabid hassantahir, b.d.s. (1) baydaa hussien,b.d.s, m.sc. (2) abstract background: polycystic ovary syndrome (pcos) is one of the most common endocrine disorders affecting women in their reproductive age.it is characterized by anovulation or oligo-ovulation and hyperandrogensim.androgen excess is the central defect in polycystic ovary syndrome. it is a complex disorder affects general health in addition to oral health.this study aimed to assess the gingival health status among a group of women with polycystic ovary syndrome as well as to estimate the levels of salivaryfree testosterone in unstimulated saliva in relation to gingival health condition. materials and methods: sixty two women with an age range 20-25 years old and with a body mass index range18.5-24.9 (normal weight) were included in this study. they were divided into two groups; the study group which included thirty one women with polycystic ovary syndrome, those women. nattended babylon teaching hospital/ infertility center and the control group which included thirty one women with regular menstrual cycles,without clinical or biochemical features of hyperandrogenism and ultrasound exclusion of polycystic ovary (without polycystic ovary syndrome). collection of unstimulated salivary samples was carried out under standardrizedconditions, salivary free testosterone levels were estimated. plaque index of silness and lӧe (1964) was used to assess dental plaque. while gingival index of lӧe and silness (1963) was used to assess gingival inflammation. data analysis was conducted through the application of the (spss version 18). the analysis of data included: mean, standard deviation, t-test, pearson correlation (r), receiver operative characteristics curve (roc curve). results:results showed that the mean value of plaque index was found to be higher in the control group (1.18±0.03) than that in the study group (1.00±0.08) with statistically highly significant difference (p<0.01).while the mean value of gingival indexwas higher among the study group (1.52±0.06)than that in the control group (1.31±0.05)with statistically highly significant difference (p<0.01).salivary levels of free testosterone among women with polycystic ovary syndrome (44.12±1.37 pg/ml) were found to be higher than that of control (18.50±0.87) with statistically highly significant difference (p<0.01).the results in this study showed that the correlations between salivary free testosterone with the oral variables (plaque index, gingival index) were statistically not significant (p>0.05). in order to assess the specificity and sensitivity of the use of salivary free testosterone as a diagnostic tool, statistical analysis of receiver operative characteristics curve (roc) was used and predictive value measurmentswere done in this study. the results showed that the area under the curve for salivary free testosterone test was (1.000) with highly significant p-value (p<0.01). the best optimal cut off point for salivary free testosterone was (30.86) with (100%) sensitivity and specificity, indicating a very good predictive capacity for using salivary free testosterone as a marker for the diagnosis of polycystic ovary syndrome. conclusions : it was concluded that gingival inflammation was high among women with polycystic ovary syndrome. furthermore, salivary levels of free testosterone were found to be high among women with polycystic ovary syndrome. key words: polycystic ovary syndrome, salivary free testosterone, plaque index, gingival index. (j bagh coll dentistry 2017; 29(1):165-169) introduction polycystic ovary syndrome (pcos) is now recognized as a common, heterogenous, heritable disorder affecting women throughout lifetime(1) and it is the leading cause of female anovulatory infertility (2) .the exact cause of pcos is unknown, however, it results from a combination of genetic and environmental factors(3). the precise prevalence of pcos is unknown as the syndrome depends on the diagnostic criteria used, however, world health organization (who) estimates that it affected 116 million women worldwide in 2012 (3.4% of women)(4).pcos is chronic condition of anovulation or oligovulation with clinical or biochemical hyperandrogenism which occurs in the absence of other underlying condition(5). (1) master student , department of pedodontic and preventive dentistry, college of dentistry, university baghdad. (2) assistant professor, department of pedodontic and preventive dentistry, college of dentistry, university baghdad. it was found that the majority of women with pcos demonstrated elevated circulating androgen levels(6). serum level of free testosterone, and not total testosterone, are more frequently elevated in women with pcos (7). it has become evident over the past 30 years that pcos is more than a reproductive disorder(8). pcos shows a link with oral health in addition to its effect on general health (9).periodontal diseases and pcos are the most common disorders in women with significant public health impact(10).this syndrome have an impact on gingival inflammation or vice versa(9).it was found that the salivary free testosterone level was high in gingivitis patients (11). salivary diagnostic approaches have been developed to monitor oral diseases such as periodontal diseases(12,14).saliva is said to be a "mirror of the body" because it provides vital clues to systemic health (14); therefore, saliva has become j bagh college dentistry vol. 29(1), march 2017 salivary free pedodontics, orthodontics and preventive dentistry 166 useful as an alternative for blood in medical diagnosis and research(15).besides, the development of new technologies may promote a wider use of salivary assay in the near future (16). as far as it is known, there was no previous iraqi study concerning the estimation of the salivary levels of free testosterone and their relation with gingival health condition among women with pcos. furthermore, in order to gain knowledge regarding the gingival health status and salivary free testosterone for this target group in which saliva may provide a simple, inexpensive and noninvasive measure, therefore, this study was designed and conducted. materials and methods the total sample composed of sixty two females aged(20-25) years with normal weight (body mass index range of 18.5-24.9). those were divided into two groups: thirty one women newly diagnosed with pcos who referred to babylon teaching hospital/ infertility clinic as a study group and thirty one women with regular menses,without clinical or biochemical features of pcos and ultrasound exclusion of polycystic ovary syndrome from the relatives of those women as a control group. this study was carried out during the period from the end of december (2014) till the end of may (2015). the study group was diagnosed according to rotterdam criteria(17).exclusion criteria included: smocking,pregnancy,previous diagnosis of condition with hormonal disturbance,presence of systemic disease(diabetes,hypertention,cardiovascurdisease),m edication affecting periodontium (antiepeliptic,immunosuppresent, antihypertensive, corticosteroid), confounding medications(contraceptive pills, steroid hormone), use of antibiotic and /or inflammatory drugs within the last months,the presence of less than 20 natural teeth (less representive for periodontal condition).collection of unstimulated salivary samples was carried out under standardrized conditions following the instruction cited by (navazesh and kumer,)(18),the salivary samples were collected and stored in -20c until analysis, salivary free testosterone level (pg/dl) was measured by elisa method using demeditec elisa kit(19). plaque index of silness and lӧe(20)was used to assess dental plaque. while gingival inflammation was evaluated using gingival index of lӧe and silness (21).data analysis was conducted through the application of the (spss version 18). the analysis of data included:mean, standard deviation, t-test, pearson correlation (r), receiver operative characteristics curve (roc curve). results table (1) shows the mean values of plaque index and gingival index among the study and control groups. it was found that the mean value of plaque index was higher in the control group than that in the study group with statistically highly significant difference (p<0.01).while the mean value of gingival index was higher among the study group than the control group with statistically highly significant difference (p<0.01). table (2) shows the mean values of salivary free testosterone for both the study and control groups. the result revealed that the salivary level of free testosterone was higher among women with pcos than their level in the control group with statistically highly significant difference (p<0.01). table (3) shows the correlation between salivary free testosterone with oral variables (pli and gi). it was found that all correlation between salivary free testosterone and oral variables were statistically not significant(p>0.05). table (4) shows the best optimal cut off point for salivary free testosterone as a diagnostic tool. it was found that the optimal cut off point for salivary free testosterone was (30.86) with (100%) sensitivity and specificity and the area under the curve was (1.00). table1: plaque index and gingival index(mean±sd) among the study andcontrol groups. variable group statistical difference study control mean ±sd mean ±sd t-test p-value pli 1.00 0.08 1.18 0.03 12.30 **0.00 gi 1.52 0.06 1.31 0.05 15.09 **0.00 **=highly significant ( p<0.01). df=60 table 2: salivary free testosterone (mean±sd) among the study and control groups. variable group statistical difference study control mean ±sd mean ±sd t-test p-value salivary free testosterone (pg/ml) 44.12 1.37 18.50 0.87 88.08 0.00** **=highly significant at p<0.01 df=60 j bagh college dentistry vol. 29(1), march 2017 salivary free pedodontics, orthodontics and preventive dentistry 167 table 3: correlation coffecient between salivary free testosterone with plaque index, gingival index among the study and control groups. variable study control pli gi pli gi free testosterone (pg/ml) r p r p r p r p -0.01 #0.98 -0.08 0.69# -0.11 #0.54 0.15 #0.43 # = not significant at p>0.05 table 4: cutoff point, sensitivity, specificity and area under curve of salivary free testosterone. variable test result variable(s) cut off sensitivity % specificity % area under curve pvalue salivary free testosterone optimal 30.86 100 100 1.00 .000** **=highly significant at p<0.01 discussion polycystic ovary syndrome (pcos) is one of the most common endocrine disorders affecting women in their reproductive years (22). it affects general health as well as oral health (9). the results of the current study showed that the mean value of the plaque index was found to be higher in the control group compared to that in the study group with statistically highly significant difference (p˂0.01). this may be due to oral health negligence in the control group and this could be attributed to lack of motivation about dental plaque control. this resultwas inconsistent with the result reported by previous studies(9,10,23)which found that the mean value of dental plaque was lower in the control group. the result of present study showed a highly significant increased gingival inflammation represented by higher gingival index among pcos group. this result was also reported by other researchers(8, 23)who found thatgingivitis was higher in the pcos group than that in the control group. this could be explained by the fact that gingival inflammation may be linked to systemic inflammation (24).it was reported that pcos is considered as a state of a low grade chronic inflammation(25).furthermore, pcos is one of the endocrine disorder characterized by hormonal imbalance and among these, steroid hormones (26) which have been mostly linked with periodontal pathogenesis (27). it was found that the gingival tissue is one of the targets for steroid hormones which can exacerbate gingivitis during period of hormonal flactuation(28). a previous study reported an increase in the level of estrogen hormone among women with pcos(26), the gingival tissue respond to increased level of estrogen hormone by undergoing vasodilatation and increased capillary permeability also there is increased migration of fluid and white blood cells out of blood vessels. cyclic increase in the production of sex steroid hormones often alter the biology of gingival tissue and vasculature, and recognition by effector cells of the local immune system (29,30). the current study revealed that salivary free testosterone level was higher in the study group than that in the control group with statistically highly significant difference (p˂0.01). this result was also reported by previous study(31). the highly significant increase in salivary free testosterone among women with pcos could be explained by the fact that androgen excess is the central defect in pcos women and hyperandrogenism is the most common characteristic feature of this syndrome, the level of serum free testosterone is increased in women with pcos (5) due to decrease sex hormone binding globulin (shbg) production (7). it was reported that there is a correlation between serum free testosterone and salivary free testosterone (32),so, the increase in the level of free testosterone in serum could explain the increase in salivary free testosterone level among women with pcos. in this study, it was found that salivary free testosterone is considered as the most specific and sensitive biochemical marker that used as a diagnostic tool for women with pcos, this is supported by the result of receiver operative characteristics curve (roc) that was used to assess the specificity and sensitivity of the use of salivary free testosterone as a biomarker for pcos. in medicine, the roc analysis had been extensively used in the evaluation of diagnostic tests (33). it was found that the area under the curve for free salivary testosterone was (1.00) and (100%) sensitivity and (100%) specificity with cut off point of (30.86) indicating very good predictive capacity for the use of salivary free testosterone as a biomarker for the diagnosis of pcos. in current study, the correlations between salivary free testosterone with oral variables (pli, gi) were found to be statistically not significant (p˃0.05). the result of this study was inconsistent with previous study(11) which found that gi, pli were significantly correlated with increased salivary free j bagh college dentistry vol. 29(1), march 2017 salivary free pedodontics, orthodontics and preventive dentistry 168 testosterone. on the other hand, another study(34)found that the level of salivary free testosterone decreased in gingivitis patients. it was reported that testosterone has an anti-inflammatory effect on periodotium(35,36). it has an inhibitory effects in the cyclooxygenasepathway of arachidonic acid metabolism in the gingiva by inhibiting prostaglandin secretion(37),and stimulates bone cell proliferation and differentiation and therefore has a positive effect on bone metabolism (38). one must keep in mind the contrast in the result among studies could be attributed to differences in diagnostic criteria employed,sample size, differences in biochemical procedures, even differences in statistical methods employed and difference in the way of saliva collecting, type of saliva collected (stimulated or unstimulated),in addition to differences in inclusion criteria used for selection of women, in this study, only women with a normal weight were included in the study while in previous studies, there was no restriction in the criteria used for selection of women with pcos. from the results of this study, it was concluded that women with pcos had high gingival inflammation, thus, an organized, comprehensive oral health preventive and educational programs in addition to the intense oral hygiene programs are essential to improve the gingivalhealth condition of women with polycystic ovary syndrome.frthermore, salivary levels of free testosterone were found to be high among women with polycystic ovary syndrome. an interesting result in this study that salivary free testosterone can be used as a marker for diagnosis of women with polycystic ovary syndrome. 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elattar tm, lin hs, tira de. testosterone inhibits prostaglandin formation by human gingival connective tissue: relationship to 14c-arachidonic acid metabolism. prostaglandins leukot med 1982;9:25-34. 38. kasperk ch, wakley g, hierl t, ziegler r. gonadal and adrenal androgens are potent regulators of human bone cell metabolism in vitro. j bone miner res 1997;12:464471. الخالصة تتميز متالزمة تكيس المبايض بعدم . تؤثر على النساء في عمر االنجاب خلفية الموضوع :متالزمة تكيس المبايض هي واحدة من اكثر اضطرابات الغدد الصماءشيوعا"التي ان متالزمة تكيس المبايض هي اضطراب .زيادة الهرمون الدكري هو االضطراب االساسي لمتالزمة تكيس المبايض .وزيادة الهرمون الدكري االباضة اواضطراب االباضة تقييملتقييم حدوث امراض اللثة لمجموعة من النساء المصابات بمتالزمة تكيس المبايض ول كانتان اهداف هذا البحث .باالضافه الى صحة الفم معقد تؤثر على الصحة العامة .للثةمحفز وعالقتها بصحة االفي اللعاب غير الحر الهرمون الذكريىمستو وتم تقسيم النساء الى ( 9.02-2.81راوحت بين )ت( سنة وباوزان طبيعية 02-02اعمارهن بين ) راوحتالمواد وطرائق العمل:شملت هده الدراسة اثنان وستون من النساء ت و واحد وثالثون امراة تشتمل على نفس , )مجموعة الدراسة(وحدة العقم/في مستشفى بابل التعليمي وعتين : واحد وثالثون امراة من المصابات بمتالزمة تكيس المبايض ممج على ارتفاع االندروجين اواالصابة بمتالزمة تكيس المبايض تحت االمواج فوق الصوتية )المجموعة المواصفات وبدورة شهرية منتظمة وليس لديهم اي عالمات او اعراض silnessا لتصنيفتم استخدام مقياس الصفيحة الجرثومية وفق.ي الحر في اللعاب غير المحفزالهرمون الذكرقياس تم موحدةتم جمع اللعاب غير المحفزفي ظروف .الضابطة( and lӧe(8992 اما )تم قياسها وفقا لمقياس اللثة فقد لتهاباlӧe and silness(8991 ). مع وجود فرق ( 21.2±22.8)من المجموعة تحت الدراسة(21.2±81.8طة)ية كان اعلى لدى المجموعة الضابالنتائج:اظهرت النتائج ان متوسط قيمة الصفيحة الجرثوم مع وجود ( 22.2 ±18.8)منه لدى المجموعة الضابطة (29.2± 20.8)بينما القيمة المتوسطة اللتهاب اللثة كانت اعلى لدى مجموعة الدراسة .معنوي عالي بين المجموعتين من مستوياتها لدى النساء في المجموعة الضابطة (13.8±80.22)وجد ان مستويات الهرمون الذكري كانت اعلى لدى النساء المصابات بتكيس المبايض .فرق معنوي عالي اظهرت نتائج هذه الدراسة بانه اليوجد فرق معنوي بخصوص ارتباطات الهرمون الذكري مع متغيرات الفم )الصفيحة .مع وجود فرق معنوي عالي( 13.2 22.81±) ائص المستقبل الفاعل الذي يستعمل لتقييم الخصوصية والحساسية الستعمال الهرمون الدكري لقد اظهرت نتائج هذه الدراسة بان اختبار منحني خص.(ةالتهاب اللث ,الجرثومية مشيرا" الى .(خصوصية٪822(حساسية و)٪822( مع )8اللعابي كمؤشر لتشخيص متالزمة تكيس المبايض وجد بان المنطقه تحت المنحني بالنسبه للهرمون الدكري كانت ) .ص متالزمة تكيس المبايضامكانية اعتباره كمؤشر جيد لتشخي عالية في لعاب النساء الحروكانت مستويات الهرمون الذكري .االستنتاجات:لقد تم االستنتاج بان التهاب اللثة كان عاليا" لدى النساء المصابات بمتالزمة تكيس المبايض .لتشخيص متالزمة تكيس المبايضالمصابات بمتالزمة تكيس المبايض مما يقترح امكانية قياسه في اللعاب كمؤشر جيد http://www.ncbi.nlm.nih.gov/pubmed/?term=laven%20js%5bauthor%5d&cauthor=true&cauthor_uid=12447098 http://www.ncbi.nlm.nih.gov/pubmed/?term=imani%20b%5bauthor%5d&cauthor=true&cauthor_uid=12447098 http://www.ncbi.nlm.nih.gov/pubmed/?term=eijkemans%20mj%5bauthor%5d&cauthor=true&cauthor_uid=12447098 http://www.ncbi.nlm.nih.gov/pubmed/?term=fauser%20bc%5bauthor%5d&cauthor=true&cauthor_uid=12447098 zaid f.doc j bagh college dentistry vol. 28(2), june 2016 the effect of nutritional pedodontics, orthodontics and preventive dentistry 152 the effect of nutritional status on mesiodistal and buccolingual (palatal) diameters of primary teeth among five years old kindergarten children zaid saadi hasan ahmed, b.d.s., m.sc., ph.d. (1) ban sahib diab, b.d.s., m.sc., ph.d. (2) abstract background: malnutrition in human life may adversely affect various aspects of growth at different stages of life. teeth are particularly sensitive to malnutrition. malnutrition may affect odontometric measurement involving tooth size dimensions. the aim of this study is to estimate the effect of nutrition on teeth size dimension measurements among children aged 5 years old. materials and methods: this study was conducted among malnourished group in comparison to well-nourished group matching with age and gender. the present study included 158 children aged 5 years (78 malnourished and 80 wellnourished). the assessment of nutritional status was done by using three nutritional indicators, namely height-for-age, weight-for-age and weight-for-height. odontometric measurements including two different orientations. for both upper and lower study models, photographs were taken using special photographic apparatus for each child, and the data were then analyzed using special computer software. for primary dentitions, two linear measurements (mesiodistal and bucco/lingual or palatal) were utilized, representing tooth diameters for each tooth. results: among children aged 5 years, the findings revealed that all means of mesiodistal and bucco-lingual diameters values of maxillary and mandibular teeth were lower among malnourished than well-nourished groups with statistically significant, except for mesiodistal diameters of both canine and lateral incisor maxillary teeth, canine of mandibular teeth and for bucco-palatal diameters of central incisor of maxillary teeth, canine, lateral incisor and central incisor of mandibular teeth. conclusions: malnutrition effect on minimize the odontometric measurements (mesio-distal and bucco-lingual diameters) among children aged 5 years. keyword: mesiodistal diameter, bucco -lingual diameter, bucco -palatal diameter, primary teeth. (j bagh coll dentistry 2016; 28(2):152-157). introduction nutrition is one of the essential needs of human beings and it provides human body with energy and essential nutrients necessary for adequate physical and social activities, and maintains or enhances its healthy state (1). malnutrition can be defined as a “pathological state resulting from absolute or relative deficiency or excess of one or more of the essential nutrients" (2). still malnutrition is one of the global highest priority health issues not only as its effects are so widespread and long lasting but also because it can be eradicated (3,4). the dental plaster models of a patient's dentition are necessary in dental measurement (5). recently, dentistry looks to digital archive and tend to be paperless patient information systems. especially when many methods have been used to determine and to analyze dental plaster casts (6). this is one of the reasons to use photograph technique to measure dimension of dental cast in this study. protein energy malnutrition might responsible for the decrease in tooth diameters (7). (1) lecturer. department of pedodontic and preventive dentistry college of dentistry, university of baghdad (2) assist. prof. department of pedodontic and preventive dentistry college of dentistry, university of baghdad this study represents the pioneering aspect. it's importance in terms of providing greater visibility to the harmful effects of malnutrition on oral pictures and change dental morphometric. materials and methods the sample collection the sample of this study involved two age groups 5 years with different nutritional status. age was recorded according to the last birthday (8). out of 240 children who were initially examined, only 158 children (78 malnourished and 80 well-nourished) were candidates selected for the morphometric analysis in this study. the pupil should not suffer from any serious systemic disease or health problem as indicated by the schools’ records, all primary teeth were erupted with no permanent tooth, the children should be free from: congenital abnormalities, congenital missing teeth, supernumerary or abnormal shape tooth and clinical signs of attrition and enamel defect. instruments and supplies plane mouth dental mirror (no. 4), sickle shape explorer (no.00), bathroom scale for recording weight, the height of the individuals was measured by using the ordinary height measuring tape, electric vibrator (quale dental), j bagh college dentistry vol. 28(2), june 2016 the effect of nutritional pedodontics, orthodontics and preventive dentistry 153 dental vernier (dentaurum 0.05 mm (042-751) germany, digital camera (6 mega pixels) sony, photographic apparatus (figure 1), software auto cad, 2006, product version z.54.10. fig. 1: photographic apparatus (13) classification of nutritional status of children aged 5 years three indicators of the subjects’ nutritional status were used to assess the nutritional status of each person in this study and they involve: height for age (h.f.a), weight for age (w.f.a) and weight for height (w.f.h). based on each nutritional status indicator, the cut off point used z-score below -2 sd and between median to +1 to classify malnutrition and well-nourished conditions respectively. and the person was classified as either malnourished or wellnourished depending on these three indicators. each z-score was considered in terms of standard deviation. the z score = individual value — median of reference population standard deviation of the reference population morphometric measurements ß photographic technique and cast orientation the three-dimension analysis of crown orientation was achieved by considering the three rotational axes of pitch, roll and yaw (9,10) . the three rotational axes introduced into the systematic description of dentofacial traits significantly improved the precision to descript tooth orientation which included crown angulation and inclination. the crown orientations represent the reference to classify each dental arch into three segments according the occlusal views (one anterior, right posterior and left posterior) to measure mesiodistal and bucco-lingual diameters of the tooth crown. tooth diameters measurements permit by capturing with photographic technique depending on these three views for each arch. before image acquisition, the cast should be oriented until incisal surfaces or occlusal surfaces of specific dental segment are orthogonal to the optical axis of the camera for each captures. this procedure was performed by putting the dental cast in surveyor base, and the cusp tips of specific segment teeth were reflected by the highest points. cast orientation was done through the rotation through which the four sides of the tooth should be well defined. the next step of orientation would be restrained by balancing the movements in the three axes (x, y and z) (define above). the incisal or occlusal view of crowns for each segment was standardized by visually maximizing the visibility of the crown’s sides (buccal, lingual, mesial, and distal) in away that it could measure tooth bucco-lingual and mesiodistal diameters (note: it is necessary to use the same orientation system for each dental typology). for each arch, four image captures were taken to three different cast orientations involving: anterior incisal segment, right and left posterior occlusal segments and occlusal surfaces of whole arch. these three photograph capture views of cast were produced as: a) the posterior occlusal segment (right or/and left) views were standardized depending on overlap line a that represented the occlusal line of four posterior teeth and the index point* that should be located between first and second molar for primary dentition. b) the anterior incisal segment view was standardized according to overlap line b which represented the occlusal line of six anterior teeth and the index point * that should be located between right and left central j bagh college dentistry vol. 28(2), june 2016 the effect of nutritional pedodontics, orthodontics and preventive dentistry 154 incisor for primary dentition (line b is a line that present on translucent horizontal plate). a reference metric system: prepare a metric scale in position parallel to and at the same level of the incisal and /or occlusal surface of cast (for each capture). by means of this metric scale, the calibration of each image dimension could be prepared. it was used to give a real metric value of the cast measurement by obtaining hypothetical factory and multiplying it with an initial measurement value of the photograph cast. final real (actual) value = hypothetical factor x initial measurement value ß taking dental cast captures after identifying landmark and orientation of each dental cast, the dental cast was placed on the portable part (5) of surveyor and oriented in an ideal way (cusps heights were not used to orient the cast segment). before taking a picture (in order to calibrate the image through suitable software), it is necessary to set a reference millimetric scale in correspondence to the occlusal surface of the tooth. ß measurement of dental cast measurements were made directly on upper and lower dental casts by photographic technique through photographic apparatus which provides a constant distance between digital camera and occlusal teeth surfaces through the plastic plate for standardization. each set of dental casts were measured to the nearest 0.001 mm. mesiodistal width is measured between two anatomical contact points (the greatest width from the anatomic mesial contact point to the distal one). bucco-lingual measurement is the maximum diameter of the crown and perpendicular to the mesiodistal diameter (11,12) . all data analyses were performed using the spss statistical software programme (version 10 for windows, spss). the confidence level was accepted at the level of 5%. *index point is that point formed by crossing of two line (a,b), and it mark on the translucent horizontal plate to standardized the cast segment for capture, as it represent the point through which optical axis of camera pass. results for primary dentition, an initial analysis was made where tooth diameters (mesiodistal and/or bucco-lingual diameter) were calculated for right and left sides separately. result found no significant difference between mean tooth diameter of right and left sides for all tooth categories (p>0.05). all subsequent statistical analysis were carried out on pooled data of right and left side measurements. table (1) illustrates the measurement of mesiodistal diameters of maxillary teeth in malnourished group and wellnourished among children aged 5 years. concerning the maxillary teeth, data reported that the mean values of second, first molars and central incisor diameters among malnourished group were highly significantly lower than wellnourished group (p< 0.01). result observed that the mean values for both canine and lateral incisor diameters among malnourished group were lower than well-nourished, with no significant difference (p> 0.05). table (2) illustrates the measurement of mesiodistal diameters of mandibular teeth in malnourished group and well-nourished of children aged 5 years. concerning the mandibular teeth, result found that the mean values of second, first molars, lateral incisor and central incisor diameters among malnourished group were highly significantly lower than well-nourished group (p< 0.01). while the mean values for canine diameter among malnourished group were significantly lower than well-nourished, with significant difference (p< 0.05). table (3) illustrates the measurement of bucco-palatal diameters of maxillary teeth in malnourished group and well-nourished among children aged 5 years. concerning maxillary teeth, data showed that the mean values for maxillary second and first molars diameters among malnourished group were highly significantly lower than well-nourished group (p< 0.01). result observed that the mean values of canine lateral and incisor diameters among malnourished group were significant lower than well-nourished (p< 0.05). result reported that the mean values for central incisor diameter among malnourished group were lower than well-nourished, with no significant difference (p [>0.05). the measurement of bucco-lingual diameters of mandibular teeth in malnourished group and well-nourished among children aged 5 years are shown in table (4). concerning the mandibular teeth, data showed that the mean value for second and first molars diameters among malnourished group were highly significantly lower than wellnourished group (p< 0.01). result observed that the mean values for canine, lateral incisor and central incisor diameters among malnourished group were lower than well-nourished, with no significant difference (p>0.05). j bagh college dentistry vol. 28(2), june 2016 the effect of nutritional pedodontics, orthodontics and preventive dentistry 155 table 1: measurement of mesiodistal diameters (mm) of maxillary teeth in malnourished and well-nourished group among children aged 5 years by gender. tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right maxillary second molar 78 8.347 0.539 80 8.623 0.53 -3.483** 0 right maxillary first molar 78 6.704 0.289 80 6.959 0.274 -5.085** 0 right maxillary canine 78 6.359 0.59 80 6.436 0.443 -0.756 0.449 right maxillary lateral incisor 78 5 0.364 80 5.108 0.339 -1.852 0.064 right maxillary central incisor 78 5.953 0.379 80 6.149 0.335 -3.099** 0.002 left maxillary second molar 78 8.385 0.536 80 8.657 0.531 -3.429** 0.001 left maxillary first molar 78 6.667 0.29 80 6.922 0.274 -5.172** 0 left maxillary canine 78 6.324 0.59 80 6.401 0.443 -0.716 0.474 left maxillary lateral incisor 78 5.036 0.367 80 5.145 0.342 -1.782 0.075 left maxillary central incisor 78 5.918 0.378 80 6.113 0.336 -3.093** 0.002 table 2: measurement of mesiodistal diameters (mm) of mandibular teeth in malnourished and well-nourished group among children aged 5 years by gender. tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right mandibular second molar 78 8.757 0.423 80 9.439 0.434 -7.908** 0 right mandibular first molar 78 7.469 0.342 80 7.713 0.311 -4.511** 0 right mandibular canine 78 5.616 0.373 80 5.74 0.34 -2.109* 0.035 right mandibular lateral incisor 78 4.818 0.323 80 4.983 0.3 -3.653** 0 right mandibular central incisor 78 4.296 0.284 80 4.445 0.316 -3.888** 0 left mandibular second molar 78 8.792 0.426 80 9.474 0.435 -7.912** 0 left mandibular first molar 78 7.433 0.339 80 7.678 0.31 -4.366** 0 left mandibular canine 78 5.581 0.369 80 5.707 0.332 -2.221* 0.026 left mandibular lateral incisor 78 4.854 0.323 80 5.019 0.301 -3.660** 0 left mandibular central incisor 78 4.289 0.285 80 4.408 0.312 -3.123** 0.002 table 3: measurement of bucco-palatal diameters (mm) of maxillary teeth in malnourished and well-nourished group among children aged 5 years by gender tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right maxillary second molar 78 9.752 0.482 80 10.011 0.48 -3.187** 0.001 right maxillary first molar 78 8.348 0.394 80 8.993 0.483 -7.731** 0 right maxillary canine 78 6.283 0.406 80 6.432 0.365 -2.315* 0.021 right maxillary lateral incisor 78 5.25 0.388 80 5.403 0.364 -2.454* 0.014 right maxillary central incisor 78 5.469 0.431 80 5.617 0.452 -1.911 0.056 left maxillary second molar 78 9.788 0.482 80 10.046 0.485 -3.187** 0.001 left maxillary first molar 78 8.314 0.396 80 8.958 0.477 -7.731** 0 left maxillary canine 78 6.318 0.411 80 6.467 0.367 -2.335* 0.02 left maxillary lateral incisor 78 5.217 0.39 80 5.37 0.367 -2.445* 0.014 left maxillary central incisor 78 5.431 0.434 80 5.581 0.452 -1.901 0.057 discussion this study was conducted to assess the effects of malnutrition, on the oral health condition which include odontometric measurements and to compare these with the control group with similar characteristics to the study group except for the factor under investigation: therefore, the control group in the present study included wellnourished subjects who possess as much similarity as possible in terms of age, gender, social structure and geographic position. the 5 years index age was selected in the present study: this age is considered a critical human life stage which has recorded the past and present history of malnutrition and oral health conditions (14,15). moreover, the study was conducted among children aged 5 years to represent the primary dentition stage, as teeth are considered to be fullsize and within the appropriate normal time of complete eruption of all primary teeth (16-18). j bagh college dentistry vol. 28(2), june 2016 the effect of nutritional pedodontics, orthodontics and preventive dentistry 156 table 4: measurement of bucco-lingual diameters (mm) of mandibular teeth in malnourished and well-nourished group among children aged 5 years by gender. tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right mandibular second molar 78 9.036 0.427 80 9.439 0.436 -5.199** 0 right mandibular first molar 78 7.313 0.755 80 7.86 0.675 -4.152** 0 right mandibular canine 78 6.035 0.353 80 6.122 0.355 -1.442 0.149 right mandibular lateral incisor 78 5.067 0.39 80 5.171 0.384 -1.647 0.1 right mandibular central incisor 78 4.694 0.395 80 4.781 0.405 -1.4 0.162 left mandibular second molar 78 9.073 0.431 80 9.477 0.437 -5.182** 0 left mandibular first molar 78 7.278 0.757 80 7.822 0.676 -4.123** 0 left mandibular canine 78 6.072 0.357 80 6.159 0.355 -1.478 0.139 left mandibular lateral incisor 78 5.031 0.389 80 5.134 0.386 -1.619 0.105 left mandibular central incisor 78 4.659 0.396 80 4.745 0.41 -1.191 0.234 in addition, the 5 age group can represent a proper time for prediction of arch dimension and they are also considered as a static stage. moreover, the complete eruption of primary dentition was accomplished by the age of three. protein energy malnutrition was assessed in the present study by using the anthropometric measurement (height, weight) through zscore standard deviation value system which expresses the anthropometric value as a score below or above the reference mean: their major advantage for the population is based on that group of scores which can be subject to statistic. the present study used three indicators (height for age, weight for age and weight for height) to classify purely malnourished from well-nourished children aged 5 years. furthermore, these measuring tools are simple and robust, and can be set up in any environment with non-invasive procedure (19). who (1995) recommended using a -2sd cut off point which represents purely statistical separation of malnourished from well-nourished; therefore, the present study used this particular cut off point for the three nutritional health indicator (height for age, height for weight and weight for age). traditional casts were eliminated with the use of computer-aided diagnosis, particularly due to problems of storage in terms of space and cost, in addition to the risks of damage because of the brittle nature of dental cast. therefore digital photography was used in this study. in the current study, it is obvious that the statistical analysis of tooth mean values of mesiodistal and bucco-lingual diameters in the upper and lower jaws revealed the absence of significant asymmetry between right and left sides for primary dentition. these findings indicated that the measurements for the right or left sides represent the mesio-distal and bucco-lingual tooth diameters for this particular sample. this finding agreed with the usual practice that teeth on one side of the jaw, or the average of the two could be used for analyzing the teeth diameters (20). this symmetrical may be attributed to the presence of similar genetic and environmental factors affecting the tooth size of teeth on the right and left sides. this particular finding is supported by other studies (19, 20). similar finding was also reported in several iraqi studies (16-18, 21-26). as for the mesio-distal and bucco-lingual diameters of the primary teeth among wellnourished, it is difficult to compare the data of present study with other studies. this may be due to differences in: the criteria of the sample selection and size; the methods used to determine tooth diameters; and the varying definitions of well-nourished group, as the previous studies might have included the different degrees of malnutrition. in general, there appears to be a clear relationship between a child's crown diameters and the mother's health during pregnancy, implying that their heritability included shared environmental as well as genetic factors. some researchers reported that children submitted to a protein deficient diet during gestation and lactation might have their affect on dental development affected, whereas children with low birth weight condition have been observed to have small tooth size in deciduous dentition (27, 28). reduction of tooth size is thought to result from a decrease in the volume of dentin rather than a reduction enamel thickness (29). thus, it is conceivable that the influence of protein energy malnutrition on tooth germs is different in the development period from that in a slightly later period. these explain the smaller mesiodistal and bucco-lingual diameters of deciduous teeth among malnourished as compared to well-nourished groups in the present study. although tooth crown morphology of deciduous dentition is determined predominantly in prenatal period. some researchers observed that the pre-natal disturbances could lead to alteration of deciduous j bagh college dentistry vol. 28(2), june 2016 the effect of nutritional pedodontics, orthodontics and preventive dentistry 157 teeth morphology (30). in case of improper weaning and during 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3: 125–131. 8. who. oral health surveys basic methods 4th ed. world health organization. geneva, switzerland. 1997. 9. ackerman jl, proffit wr, sarver dm, ackerman mb, kean mr. pitch, roll, and yaw: describing the spatial orientation of dentofacial traits. am j orthod dentofacial orthop 2007; 131: 305-10 10. proffit wr, fields hw, sarver dm. contemporary orthodontics. 4th ed. st. louis: mosby; 2007. pp. 167233 11. hunter ws, priest wr. errors and discrepancies in measurement of tooth size. j dent res 1960, 39: 40514. 12. brace cl. classic neanderthals, and the evolution of the european face. j human evolution 1979, 8: 52750. 13. hasan zs. the effect of nutritional status on dental health, salivary physicochemical characteristics and odontometric measurements among five years old kindergarten children and fifteen years old students. ph.d. thesis, college of dentistry, baghdad university, 2010. 14. lingström p, moynihan p. nutrition, saliva, and oral health. nutrition 2003; 19: 567-9. 15. warren jj, weber-gasparoni k, marshall ta, drake, dr, dehkordi-vakil f, kolker jl, dawson dv. factors associated with dental caries experience in 1-year-old children. j public health dentistry 2008; 68(2): 70-5. 16. hikmat bym. mesiodistal diameter and occlusal feature in the primary dentition of 4-5 years old children from baghdad –iraq. master thesis, college of dentistry baghdad university, 1989. 17. al-timimy ia. anterior dental crown and its relationship to mesiodistal crown diameter of the teeth and arch dimension in three classes of molar relation. a master thesis, college of dentistry baghdad university, 2000. 18. al-sagar ma. deciduous teeth size and jaw dimensions for iraqi children (4-5) years (cross sectional study). a master thesis, college of dentistry baghdad university, 2003. 19. who. physical status: the use and interpretation of anthropometry. report of a who expert committee. who technical report series 854. geneva world health organization. 1995. 20. bishara se, jakobsen jr, abdallah em, garcia af. comparisons of mesio-distal and bucco-lingual crown dimensions of the permanent teeth in the three populations from egypt, mexico, and the united states. am j orthod dentofac orthop 1989; 96: 41622. 21. otuyemi od, noar jh. a comparison of crown size dimensions in a nigerian and a british population. euro j orthod 1996; 18: 623-28. 22. ghose, l, baghdady vs. analysis of the iraq dentition: mesiodistal crown diameters of permanent teeth. j dent res 1979; 58: 1047-54. 23. sofia sh. mesio-distal crown diameter of permanent teeth and prediction chart for mixed dentition analysis. a master thesis, college of dentistry baghdad university, 1996. 24. salem nm. facial and arch forms and dimensions in a sample of 16-21 years old palestinian class i occlusion. master thesis, college of dentistry baghdad university, 2003. 25. al-janabi whe. dental caries, enamel defect and malocclusion of primary dentition in relation to nutritional status among kindergarten children in hilla city. a master thesis, college of dentistry baghdad university, 2008. 26. murad sm. accuracy of measurements made on digital and study models (a comparative study). master thesis, college of dentistry baghdad university, 2008. 27. fearne j, brook a. small primary tooth crown primary tooth crown size in low birthweight children. early human development 1993, 33:81-90. 28. seow w, wan a. a controlled study of the morphometric changes in the primary dentition of preterm, very –lowbirthweight children. j dental res 2000, 24:141-6. 29. huumonen s, larmas m. effects of protein deficiency induced by raw soy with and without sucrose on dentine formation and dentinal caries in young rats. arch oral biol 2005; 50:453–9. 30. garn s, osborne r, mccabe k. the effect of prenatal factors on crown dimensions. am j physical anthropol 1979; 51: 665-78. dropbox 6 omer 29-33.pdf simplify your life ban f.doc j bagh college dentistry vol. 28(2), june 2016 the effect of pedodontics, orthodontics and preventive dentistry 108 the effect of nutritional status on mesiodistal and bucco/ lingual or palatal diameters of permanent teeth among fifteen years old students zaid saadi hasan ahmed, b.d.s., m.sc., ph.d. (1) ban sahib diab, b.d.s., m.sc., ph.d. (2) abstract background: malnutrition during human growth affects the size of the tissues at different stages of life, body proportions, body chemistry, as well as quality and texture of tissues. teeth are particularly sensitive to malnutrition. malnutrition may affect odontometric measurement involving tooth size dimensions. the aim of this study was to estimate the effect of nutrition on teeth size dimension measurements among students aged 15 years old. materials and methods: this study was conducted among malnourished group in comparison to well-nourished group matching with age and gender. the present study included 167 students aged 15 years (83 malnourished and 84 wellnourished). the assessment of nutritional status was done by using body mass index (bmi). odontometric measurements included three different orientations. for both upper and lower study models, photographs were taken using special photographic apparatus for each student, and the data were then analyzed using special computer software. for permanent dentitions, two linear measurements (mesiodistal and bucco \lingual or palatal) were utilized, representing tooth diameters for each tooth. results: among students aged 15 years, the findings revealed that all means of mesiodistal and bucco-lingual diameters values of maxillary and mandibular teeth were lower among malnourished than well-nourished groups with statistically significant, except for mesiodistal diameters of both second molar, second and first premolar of maxillary teeth, second premolar, first premolar and lateral incisor of mandibular teeth and for bucco-palatal diameters of second and first premolar of maxillary teeth, second molar and lateral incisor of mandibular teeth. conclusion: malnutrition effect on minimize the odontometric measurements (mesiodistal and bucco-lingual diameters) among students aged 15 years. keyword: mesiodistal diameter, bucco -lingual diameter, bucco -palatal diameter, permanent teeth. (j bagh coll dentistry 2016; 28(2):108-114). introduction nutrition is the provision of adequate energy and nutrients to the cells for them to perform adequate physical and social activities, and maintains or enhances its healthy state (1). malnutrition can be defined as a “pathological state resulting from absolute or relative deficiency or excess of one or more of the essential nutrients" (2). still malnutrition is one of the global highest priority health issues not only as its effects are so widespread and long lasting but also because it can be eradicated (3). the dental plaster models of a patient's dentition are necessary in dental measurement (4). recently, dentistry looks to digital archive and tend to be paperless patient information systems. especially when many methods have been used to determine and to analyze dental plaster casts (5). this is one of the reasons to use photograph technique to measure dimension of dental cast in this study. protein energy malnutrition might responsible for the decrease in tooth diameters (6). (1) lecturer. department of pedodontic and preventive dentistry college of dentistry, university of baghdad (2) assist. prof. department of pedodontic and preventive dentistry college of dentistry, university of baghdad this study represents the pioneering aspect. it's importance in terms of providing greater visibility to the harmful effects of malnutrition on oral pictures and change dental morphometric. materials and methods the sample collection the collection of sample in present study involved age group 15 years with different nutritional status. age was recorded according to the last birthday (7). out of 220 who were initially examined, only 167 students (83 malnourished and 84 well-nourished) were candidates selected for the morphometeric analysis in this study. the pupil should not suffer from any serious systemic disease or health problem as indicated by the schools’ records, all permanent teeth were erupted, with exception of the third molar (8). the students should be free from: congenital abnormalities, congenital missing teeth, supernumerary or abnormal shape tooth and clinical signs of attrition and enamel defect. instruments and supplies plane mouth dental mirror (no. 4), sickle shape explorer (no.00), bathroom scale for recording weight, the height of the individuals was measured by using the ordinary height measuring tape, electric vibrator (quale dental), j bagh college dentistry vol. 28(2), june 2016 the effect of pedodontics, orthodontics and preventive dentistry 109 dental vernier (dentaurum 0.05 mm (042-751) germany, digital camera (6 mega pixels) sony, photographic apparatus (figure 1), software auto cad, 2006, product version z.54.10. classification of nutritional status of students aged 15 years body mass index: this index was used to determine the nutritional status of persons aged 15 years. the index represents a number that is calculated from weight and height according to the following formula: bmi = weight (kg ) height (meter) 2 in present study, the cut-off point of bmi at sd below -2 was used to determine the person as malnourished, the sd between median and below +1 for well-nourished morphometric measurements photographic technique and cast orientation the three-dimension analysis of crown orientation was achieved by considering the three rotational axes of pitch, roll and yaw (9,10). the three rotational axes introduced into the systematic description of dentofacial traits significantly improved the precision to descript tooth orientation which included crown angulation and inclination. the crown orientations represent the reference to classify each dental arch into three segments according the occlusal views (one anterior, right posterior and left posterior) to measure mesiodistal and bucco-lingual diameters of the tooth crown. tooth diameters measurements permit by capturing with photographic technique depending on these three views for each arch. before image acquisition, the cast should be oriented until incisal surfaces or occlusal surfaces of specific dental segment are orthogonal to the optical axis of the camera for each captures. this procedure was performed by putting the dental cast in surveyor base, and the cusp tips of specific segment teeth were reflected by the highest points. cast orientation was done through the rotation through which the four sides of the tooth should be well defined. the next step of orientation would be restrained by balancing the movements in the three axes (x, y and z)(define above). the incisal or occlusal view of crowns for each segment was standardized by visually maximizing the visibility of the crown’s sides (buccal, lingual, mesial, and distal) in away that it could measure tooth bucco-lingual and mesiodistal diameters (note: it is necessary to use the same orientation system for each dental typology). for each arch, four image captures were taken to three different cast orientations involving: anterior incisal segment, right and left posterior occlusal segments and occlusal surfaces of whole arch. these three photograph capture views of cast were produced as: a) the posterior occlusal segment (right or/and left) views were standardized depending on overlap line a that represented the occclusal line of four posterior teeth and the index point* that should be located between second premolar and first molar for permanent dentition (line a is a line that present on translucent horizontal plate). b) the anterior incisal segment view was standardized according to overlap line b which represented the occlusal line of six anterior teeth and the index point * that should be located between right and left central incisor for permanent dentition (line b is a line that present on translucent horizontal plate). a reference metric system: prepare a metric scale in position parallel to and at the same level of the incisal and /or occlusal surface of cast (for each capture). by means of this metric scale, the calibration of each image dimension could be prepared. it was used to give a real metric value of the cast measurement by obtaining hypothetical factory and multiplying it with an initial measurement value of the photograph cast. final real (actual) value = hypothetical factor * initial measurement value. ß taking dental cast captures after identifying landmark and orientation of each dental cast, the dental cast was placed on the portable part of surveyor and oriented in an ideal way (cusps heights were not used to orient the cast segment). before taking a picture (in order to calibrate the image through suitable software), it is necessary to set a reference millimetric scale in correspondence to the occlusal surface of the tooth. ß measurement of dental cast dental cast measurements were made directly on upper and lower dental casts by photographic technique through photographic apparatus which provides a constant distance between digital camera and occlusal teeth surfaces through the plastic plate for standardization. each set of dental casts were measured to the nearest 0.001 mm. mesiodistal width is measured between two anatomical contact points (the greatest width from the anatomic mesial contact point to the distal j bagh college dentistry vol. 28(2), june 2016 the effect of pedodontics, orthodontics and preventive dentistry 110 one). bucco-lingual measurement is the maximum diameter of the crown and perpendicular to the mesiodistal diameter (11,12). all data analyses were performed using the spss statistical software programme (version 10 for windows, spss). the confidence level was accepted at the level of 5%. *index point is that point formed by crossing of two line (a,b), and it mark on the translucent horizontal plate to standardized the cast segment for capture, as it represent the point through which optical axis of camera pass fig. 1: photographic apparatus (13) results for permanent dentition, an initial analysis was made where tooth diameters (mesiodistal and/or bucco-lingual diameter) were calculated for right and left sides separately. result found no significant difference between mean tooth diameter of right and left sides for all tooth categories (p>0.05). all subsequent statistical analysis were carried out on pooled data of right and left side measurements. table (1) illustrates the measurement of mesiodistal diameters of maxillary teeth in malnourished group and well-nourished among students aged 15 years. concerning the maxillary teeth, data reported that the mean values of first molars, canine and central incisor diameters among malnourished group were highly significantly lower than well-nourished group (p< 0.01). result observed that the mean values of lateral incisor diameters among malnourished group were significant lower than well-nourished (p< 0.05). result observed that the mean values for both second molar, second and first premolar diameters among malnourished group were lower than well-nourished, with no significant difference (p> 0.05). table (2) illustrates the measurement of mesiodistal diameters of mandibular teeth in malnourished group and well-nourished of students aged 15 years. concerning the mandibular teeth, result found that the mean values of first molars and canine diameters among malnourished group were highly significantly lower than well-nourished group (p< 0.01). result observed that the mean values of second molar and central incisor diameters among malnourished group were significant lower than well-nourished (p< 0.05). result observed that the mean values for second premolar, first premolar and lateral incisor diameters among malnourished group were lower than well-nourished, with no significant difference (p> 0.05). table (3) illustrates the measurement of bucco-palatal diameters of maxillary teeth in malnourished group and well-nourished among students aged 15 years. concerning maxillary teeth, data showed that the mean values for maxillary second molar, first molar, canine and central incisor diameters among malnourished group were highly significantly lower than wellnourished group(p< 0.01). result observed that the mean values of lateral incisor diameters among malnourished group were significant lower than well-nourished (p< 0.05). result reported that the mean values for second and first premolar diameter among malnourished group were lower than well-nourished, with no significant difference (p >0.05). j bagh college dentistry vol. 28(2), june 2016 the effect of pedodontics, orthodontics and preventive dentistry 111 the measurement of bucco-lingual diameters of mandibular teeth in malnourished group and well-nourished among students aged 15 years are shown in table (4). concerning the mandibular teeth, data showed that the mean value for first molar diameters among malnourished group were highly significantly lower than well-nourished group (p< 0.01). result observed that the mean values of second premolar, first premolar, canine and central incisor diameters among malnourished group were significant lower than well-nourished (p< 0.05). result observed that the mean values for second molar and lateral incisor diameters among malnourished group were lower than well-nourished, with no significant difference (p>0.05). table 1: measurement of mesiodistal diameters (mm) of maxillary teeth in malnourished and well-nourished group among adolescent aged 15 years by gender tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right maxillary second molar 83 9.391 0.478 84 9.496 0.438 -1.762 0.078 right maxillary first molar 83 9.636 0.56 84 10.36 0.526 -7.767** 0 right maxillary second premolar 83 7.021 0.55 84 7.086 0.53 -0.763 0.445 right maxillary first premolar 83 6.97 0.373 84 7.062 0.375 -1.767 0.077 right maxillary canine 83 7.578 0.687 84 7.903 0.805 -3.034** 0.002 right maxillary lateral incisor 83 6.458 0.69 84 6.673 0.707 -2.177* 0.03 right maxillary central incisor 83 8.018 0.616 84 8.525 0.636 -5.051** 0 left maxillary second molar 83 9.369 0.506 84 9.522 0.482 -1.887 0.059 left maxillary first molar 83 9.603 0.583 84 10.326 0.551 -7.612** 0 left maxillary second premolar 83 7.009 0.525 84 7.064 0.552 -0.986 0.324 left maxillary first premolar 83 6.924 0.401 84 7.035 0.413 -1.892 0.059 left maxillary canine 83 7.541 0.693 84 7.809 0.855 -2.742** 0.006 left maxillary lateral incisor 83 6.436 0.695 84 6.657 0.707 -2.037* 0.042 left maxillary central incisor 83 7.994 0.632 84 8.498 0.659 -4.846** 0 *p< 0.05, ** p<0.01 table 2: measurement of mesiodistal diameters (mm) of mandibular teeth in malnourished and well-nourished group among adolescent aged 15 years by gender tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right mandibular second molar 83 9.751 0.635 84 9.97 0.628 -2.313* 0.021 right mandibular first molar 83 10.303 0.496 84 11.045 0.516 -7.700** 0 right mandibular second premolar 83 7.06 0.428 84 7.139 0.458 -1.853 0.064 right mandibular first premolar 83 6.798 0.413 84 6.919 0.397 -1.887 0.059 right mandibular canine 83 6.641 0.536 84 6.866 0.843 -5.602** 0 right mandibular lateral incisor 83 6.162 0.559 84 6.282 0.543 -1.397 0.162 right mandibular central incisor 83 5.326 0.573 84 5.532 0.561 -2.303* 0.021 left mandibular second molar 83 9.714 0.664 84 9.949 0.659 -2.415* 0.016 left mandibular first molar 83 10.263 0.534 84 11.003 0.553 -7.293** 0 left mandibular second premolar 83 7.008 0.461 84 7.124 0.487 -1.762 0.078 left mandibular first premolar 83 6.72 0.446 84 6.855 0.45 -1.913 0.056 left mandibular canine 83 6.606 0.556 84 6.872 0.593 -2.642** 0.008 left mandibular lateral incisor 83 6.141 0.562 84 6.266 0.545 -1.557 0.119 left mandibular central incisor 83 5.222 0.567 84 5.443 0.57 -2.481* 0.013 *p< 0.05, ** p<0.01 discussion this study was conducted to assess the effects of malnutrition, on the oral health condition which include odontometric measurements and to compare these with the control group with similar characteristics to the study group except for the factor under investigation: therefore, the control group in the present study included wellnourished subjects who possess as much similarity as possible in terms of age, gender, social structure and geographic position. the 15 years index age was selected in the present study: this age is considered a critical human life stage which has recorded the past and present history of malnutrition and oral health conditions (14). j bagh college dentistry vol. 28(2), june 2016 the effect of pedodontics, orthodontics and preventive dentistry 112 table 3: measurement of bucco-palatal diameters (mm) of maxillary teeth in malnourished and well-nourished group among adolescent aged 15 years by gender tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right maxillary second molar 83 10.062 0.541 84 11.702 0.576 -10.717** 0 right maxillary first molar 83 10.019 0.368 84 10.327 0.345 -5.073** 0 right maxillary second premolar 83 8.347 0.394 84 8.436 0.405 -1.666 0.096 right maxillary first premolar 83 8.327 0.312 84 8.375 0.315 -0.964 0.335 right maxillary canine 83 7.179 0.442 84 7.568 0.469 -5.421** 0 right maxillary lateral incisor 83 5.829 0.505 84 6.036 0.513 -2.532* 0.011 right maxillary central incisor 83 6.582 0.518 84 6.949 0.531 -4.203** 0 left maxillary second molar 83 9.889 0.654 84 11.709 0.616 -10.571** 0 left maxillary first molar 83 9.791 0.489 84 10.321 0.411 -6.674** 0 left maxillary second premolar 83 8.313 0.415 84 8.427 0.431 -1.802 0.072 left maxillary first premolar 83 8.303 0.353 84 8.332 0.348 -0.611 0.541 left maxillary canine 83 7.065 0.488 84 7.583 0.485 -6.333** 0 left maxillary lateral incisor 83 5.814 0.507 84 6.024 0.517 -2.486* 0.013 left maxillary central incisor 83 6.572 0.519 84 6.925 0.535 -3.956** 0 *p< 0.05, ** p<0.01 table 4: measurement of bucco-lingual diameters (mm) of mandibular teeth in malnourished and well-nourished group among adolescent aged 15 years by gender tooth malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value right mandibular second molar 83 9.491 0.428 84 9.578 0.479 -1.498 0.134 right mandibular first molar 83 9.195 0.417 84 9.652 0.432 -5.822** 0 right mandibular second premolar 83 7.625 0.396 84 7.781 0.405 -2.550* 0.011 right mandibular first premolar 83 7.085 0.401 84 7.232 0.417 -2.566* 0.01 right mandibular canine 83 6.725 0.46 84 6.9 0.494 -2.156* 0.031 right mandibular lateral incisor 83 5.768 0.521 84 5.816 0.52 -0.996 0.319 right mandibular central incisor 83 5.374 0.531 84 5.582 0.584 -2.193* 0.028 left mandibular second molar 83 9.441 0.448 84 9.552 0.506 -1.692 0.091 left mandibular first molar 83 9.129 0.448 84 9.602 0.474 -5.869** 0 left mandibular second premolar 83 7.597 0.397 84 7.77 0.42 -2.495* 0.013 left mandibular first premolar 83 7.056 0.429 84 7.201 0.449 -2.298* 0.022 left mandibular canine 83 6.692 0.494 84 6.862 0.534 -2.074* 0.038 left mandibular lateral incisor 83 5.681 0.513 84 5.726 0.522 -0.815 0.415 left mandibular central incisor 83 5.347 0.545 84 5.561 0.6 -2.295* 0.022 *p< 0.05, ** p<0.01 moreover, the study was conducted among students aged 15 years to represent the permanent dentition stage, as teeth are considered to be fullsize and within the appropriate normal time of complete eruption of all permanent teeth (15). in addition, the 15 age group can represent a proper time for prediction of arch dimension and they are also considered as a static stage. moreover, the complete eruption of permanent dentition is accomplished by the age of fifteen. protein energy malnutrition was assessed in the present study by using body mass index (bmi), and it was used to screen the weight categories according to who (2007), as an alternative to the use of the three indicators of nutritional status (height for age, weight for age and weight for height). bmi has been used to assess the size and growth pattern of individual, which indicate the relative posit ion of students' bmi in the growth table that showing the weight condition categories (16). furthermore, these measuring tools are simple and robust, and can be set up in any environment with non-invasive procedure. who (1995) (17) recommended using a -2sd cut off point which represents purely statistical separation of malnourished from well-nourished. traditional casts were eliminated with the use of computeraided diagnosis, particularly due to problems of storage in terms of space and cost, in addition to the risks of damage because of the brittle nature of dental cast. therefore digital photography was used in this study. in the current study, it is obvious that the statistical analysis of tooth mean values of mesiodistal and bucco-lingual diameters in the upper and lower jaws revealed the absence of significant asymmetry between right and left j bagh college dentistry vol. 28(2), june 2016 the effect of pedodontics, orthodontics and preventive dentistry 113 sides for permanent dentition. these findings indicated that the measurements for the right or left sides represent the mesio-distal and buccolingual tooth diameters for this particular sample. this finding agreed with the usual practice that teeth on one side of the jaw, or the average of the two could be used for analyzing the teeth diameters (18). this symmetrical may be attributed to the presence of similar genetic and environmental factors affecting the tooth size of teeth on the right and left sides. this particular finding is supported by other studies (17,18). similar finding was also reported in several iraqi studies (15,19-21). as for the mesiodistal and bucco-lingual diameters of the primary teeth among wellnourished, it is difficult to compare the data of present study with other studies. this may be due to differences in: the criteria of the sample selection and size; the methods used to determine tooth diameters; and the varying definitions of well-nourished group, as the previous studies might have included the different degrees of malnutrition. in general, there appears to be a clear relationship between a child's crown diameters and the mother's health during pregnancy, implying that their heritability included shared environmental as well as genetic factors. some researchers reported that children submitted to a protein deficient diet during gestation and lactation might have their affect on dental development affected, whereas children with low birth weight condition have been observed to have small tooth size in deciduous dentition (22, 23). reduction of tooth size is thought to result from a decrease in the volume of dentin rather than a reduction enamel thickness (24) . thus, it is conceivable that the influence of protein energy malnutrition on tooth germs is different in the development period from that in a slightly later period. although tooth crown morphology of deciduous dentition is determined predominantly in prenatal period and permanent teeth calcify post-natally. some researchers observed that the pre-natal disturbances could lead to alteration of permanent teeth morphology to a degree as compared to that of deciduous teeth (25). these explain the smaller mesiodistal and bucco-lingual diameters of permanent teeth among malnourished as compared to well-nourished groups in the present study. in case of improper weaning and during period precede tooth development, protein energy malnutrition might disrupt environmental homeostasis during the advance stage of tooth formation and maturation, and the odontoblastic layer in this condition might be responsible for the apparent decrease in the diameter and density of the collagen fibrils of the intertubular dentin (6). this proves the smaller mesiodistal and bucco-lingual tooth diameters among malnourished group in compare to wellnourished group for the permanent dentition. references 1. blössner m, onis m. malnutrition. quantifying the health impact at national and local levels. geneva, world health organization, 2005. (who environmental burden of disease series, no. 12). 2. park je, park k. park’s textbook of preventive of social medicine. 29th ed. jabalpur: banarsidas bhanol 2007. 3. malik ma, hussain w. under-nutrition and its association with mortality in hospitalized patients. pak paed j 2006; 23(4): 63-6. 4. santoro m, michael e, ayoub va, thomas j, cangialosi. mesiodistal crown dimensions and tooth size discrepancy of the permanent dentition of dominican americans. angle orthod 2000; 70(4): 303-7. 5. quimby ml, vig kw, rashid rg, firestone ar. the accuracy and reliability of measurements made on computerbased digital models. angle orthod 2004; 74: 298-303. 6. gonçalves la, boldrini sc, capote tso, binotti cb, azeredo ra, martini dt, rosenberg b, bautz wg liberti ea. structural and ultra-structural features of the first mandibular molars of young rats submitted to pre and postnatal protein deficiencies. open dent j 2009; 3: 125–31. 7. who. oral health surveys basic methods 4th ed. world health organization. geneva, switzerland. 1997. 8. raberin m, laumon b, martin j, brunner f. dimensions and form of dental arches in subjects with normal occlusion. am j orthod. dentofacial orthop 1993; 103: 67-72. 9. ackerman jl, proffit wr, sarver dm, ackerman mb, kean mr. pitch, roll, and yaw: describing the spatial orientation of dentofacial traits. am j orthod dentofacial orthop 2007; 131: 305-10. 10. proffit wr, fields hw, sarver dm. contemporary orthodontics. 4th ed. st. louis: mosby; 2007. pp. 167233 11. hunter ws, priest wr. errors and discrepancies in measurement of tooth size. j dent res 1960; 39: 40514. 12. brace cl. classic neanderthals, and the evolution of the european face. j human evolution 1979; 8: 527550. 13. hasan zs. the effect of nutritional status on dental health, salivary physicochemical characteristics and odontometric measurements among five years old kindergarten children and fifteen years old students. ph.d. thesis, college of dentistry, baghdad university, 2010. 14. lingström p, moynihan p. nutrition, saliva, and oral health. nutrition 2003, 19: 567-9. 15. al-timimy ia. anterior dental crown and its relationship to mesiodistal crown diameter of the teeth and arch dimension in three classes of molar relation. j bagh college dentistry vol. 28(2), june 2016 the effect of pedodontics, orthodontics and preventive dentistry 114 a master thesis, college of dentistry baghdad university, 2000. 16. deonis m, garza b, habicht j-p. time for a new growth reference. pediatrics 1997; 100(5): e8. 17. who. physical status: the use and interpretation of anthropometry. report of a who expert committee. who technical report series 854. geneva world health organization. 1995. 18. bishara se, jakobsen jr, abdallah em, garcia af. comparisons of mesio-distal and bucco-lingual crown dimensions of the permanent teeth in the three populations from egypt, mexico, and the united states. am j orthod dentofac orthop. 1989; 96: 41622. 19. sofia sh. mesio-distal crown diameter of permanent teeth and prediction chart for mixed dentition analysis. a master thesis, college of dentistry baghdad university-iraq. 1996. 20. salem nm. facial and arch forms and dimensions in a sample of 16-21 years old palestinian class i occlusion. a master thesis, collaege of dentistry baghdad university-iraq. 2003. 21. murad sm. accuracy of measurements made on digital and study models (a comparative study). a master thesis, college of dentistry baghdad university-iraq. 2008. 22. fearne j, brook a. small primary tooth crown primary tooth crown size in low birth weight children. early human development 1993; 33: 81-90. 23. seow w, wan a. a controlled study of the morphometric changes in the primary dentition of preterm, very –lowbirth weight children. j dental res 2000, 24:141-6. 24. huumonen s, larmas m. effects of protein deficiency induced by raw soy with and without sucrose on dentine formation and dentinal caries in young rats. arch oral biol 2005; 50: 453–9. 25. garn s, osborne r, mccabe k. the effect of prenatal factors on crown dimensions. am j physical anthropol 1979; 51: 665-78. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 44 research article effect of resin infiltration and microabrasion on the microhardness of the artificial white spot lesions (an in vitro study) reem majeed h.j. al-mamoori1*, aseel haidar m.j. al haidar2 1 master student, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. 2 assistant professor, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. bab-almoadham, p.o. box 1417, baghdad, iraq *correspondence: reem.jasim1901@codental.uobaghdad.edu.iq abstract: background: white spot lesion is the first visible sign of dental caries that is characterized by demineralized lesion underneath an intact surface. several studies demonstrated that they could be treated using noninvasive techniques like the use of fluoride or casein phosphopeptide and amorphous calcium phosphate. improvement in aesthetic outcomes by covering the demineralized enamel is one of the advantages of the use of resin infiltration and opalustre microabrasion, which are two new techniques that had been used for treatment of white spot lesion. the purpose of this study was to evaluate the impact of resin infiltration and microabrasion in the microhardness of the artificial white spot lesions at various depths. material and method: forty-eight artificially white spot lesions were divided into three groups (n=16) according to the depth of the lesion (shallow enamel, deep enamel, shallow dentine). then, each of the main groups was divided into two subgroups (n = 8), the first group was treated with resin infiltration, while the second one was treated with opalustre microabrasion. assessment of the microhardness was done using vickers hardness at the baseline, after demineralization (formation of the white spot lesion) and after the treatment with the resin infiltration and the microabrasion. results: there was a significant difference in the microhardness of all the layers after demineralization. although the hardness values that found among the icon group in the inner enamel and the outer dentine were higher than that of the opalustre, statistically there was no significant difference between the two materials in all the layers of the white spot lesion. conclusion: microhardness values decrease as the depth of the white spot lesion increase. there was an increase in the microhardness values after the treatment with the resin infiltration and the microabrasion. keywords: microabrasion, microhardness, resin infiltration, white spot lesions. introduction increase awareness was noticed among people for the importance of the presence of a beautiful smile so they are seeking and demanding aesthetic solutions (1,2). white spot lesions (wsls) are white enamel patches caused by mineral loss in the enamel's subsurface layer. incipient or enamel caries are terms used to describe these areas. they are the precursors to dental cavities, and their opaque color can result in cosmetic issues that can last many years (3). to prevent these lesions from developing into cavities, prompt identification and treatment are required and as these lesions can be remineralized and monitored over time; early diagnosis is crucial (4). the diagnodent 2190, also known as the diagnodent pen, is a diagnostic device that emits reflected fluorescent light at 700–800 nm after pulsed laser irradiation of a carious lesion (5,6). values between these lesions can be remineralized and monitored over time; early diagnosis is crucial (4). received date : 1202-12-10 accepted date : 2022-1-14 published date : 2022-3-15 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbcd .v34i1.3091 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3091 https://doi.org/10.26477/jbcd.v34i1.3091 j. bagh. coll. dent. vol. 34, no. 1. 2022 al-mamoori and al haidar 45 the diagnodent 2190, also known as the diagnodent pen, is a diagnostic device that emits reflected fluorescent light at 700–800 nm after pulsed laser irradiation of a carious lesion (5,6). values between 6 and 20 show enamel lesions, values between 20 and 30 suggested superficial dentinal lesions, while values over 30 indicate severe dentinal caries. several studies looked at the reliability and the validity of the diagnodent in measuring the wsls and the smooth surface caries (7,8). for the treatment of wsls, various treatments have been proposed; some are conservative, like the remineralization treatment, while others are more aggressive, like bleaching (9,10). resin infiltration has been intensively investigated as far as more dental tissue-preserving strategy to halt and manage smooth surface or proximal lesions. the goal of this concept is the obstructing of the high porosity of an early enamel lesion using low-viscosity resins. this method genuinely adheres to the concepts of noninvasive dentistry, which aid in the detection of incipient lesions using diagnostic instruments as well as the limited invasive intervention of the cavitated lesions (11). furthermore, the resin-filled microporosities cannot evaporate, resulting in immediate aesthetic enhancement (12). on the other hand, microabrasion was reported by roberson et al. in 2002 as a conservative option for the reduction or eradication of the superficial discolorations. it has a wide range of uses, including the elimination of the surface non-carious enamel irregularities and nowadays it had been proposed as a method for removing the demineralized white lesions (13). a paste containing hydrochloric acid and pumice is applied to the affected tooth surfaces to uniformly remove up to 0.2 μm of enamel surface using a combination of chemical erosion and mechanical abrasion. microabrasion produces a glossy, glass-like enamel surface that may refract and reflect light in a number of ways (14,15). any remaining underlying enamel stains may be concealed by these optical qualities, saliva hydration of the teeth improves these favorable optical properties (10). microhardness testing of the demineralized and the treated lesions at various depths of enamel and dentine is an effective approach for obtaining indirect information about the changes concerning the mineral content in dental hard tissues. furthermore, no available iraqi study had been found concerning the evaluation of the effect of the resin infiltration and the microabrasion of the artificial white spot lesions at various depths. therefore, this study aimed to assess the surface qualities of the artificially induced white spot lesions after treatment with the resin infiltration and microabrasion in terms of the surface microhardness at various depth. the null hypothesis suggests that there is no significant difference in microhardness of resin infiltration and opalustre microabrasion material at various depths of demineralization. materials and methods samples a total of 48 sound premolars were extracted, for orthodontic demand, from patients aged 12-20 years old (16,17). they were obtained from different private and public dental clinics in baghdad city. teeth with hypoplasia, crack, incipient carious lesions/white spots and filling were excluded after being checked by 10x magnifying lens. in order to eliminate the debris and soft tissues, all the teeth were washed and polished using non fluoridated type of pumice slurry (pd, switzerland), the collected teeth were stored for one week in a 0.05 % thymol solution (an antimicrobial solution that inhibits bacterial growth). then, the teeth soaked in deionized distilled water (ddw) until they were subjected to any intervention (18). sample preparation in order to prepare flat surface for vicker’s microhardness testing, the buccal surface of each tooth was polished with sof-lex disks (3m espe, usa) in a progressive manner (beginning with the coarse, then medium and fine, ending with the superfine) using contra-angle slow-speed hand-piece. j. bagh. coll. dent. vol. 34, no. 1. 2022 al-mamoori and al haidar 46 then a circular opening of 6mm in diameter was standardized on the buccal surface of every tooth with a ruler. an imaginary line was drawn on the tip of the buccal cusp to the cervical line, as well as additional line among the mesial and distal tooth surfaces at their most prominent curvature, to determine the middle area of the buccal surface. then, a 6mm adhesive tape circle was cut and put on the buccal surface of the tooth. after that, the tooth was painted with an acid resistant nail varnish after that adhesive tape was removed, leaving a circular window on the buccal surface of the tooth, following the demineralization, the specimens were properly washed in deionized distilled water (ddw) once more (19). wsls formation two hundred ml of demineralizing solution was prepared (2.2 mm potassium dihydrogen phosphate (kh2po4), 2.2 mm calcium chloride (cacl2), and 50 mm acetic acid) for a whole day (20). all of the teeth were immersed in an artificial caries solution for a whole day with ph of 5 at 37°c, the solution was changed daily until the frosty white appearance was achieved. the extent of the white spot lesion was assessed on daily basis with a diagnodent pen. if the extent of the lesion was not sufficient, the teeth were immersed again in the artificial caries solution (21). the readings of the induced wsls in the shallow enamel were ranged between 6 and 14, which assembled in about a week. while the readings of deep enamel lesion were ranged from 15 to 20 and they took about 10 days to be yield. a duration period of about 15 days was needed to induce wsls in the shallow dentine by which their readings were ranged between 21and 29 (22). treatment groups after wsls formation the main three groups were allocated randomly into two groups, each group of 8 teeth, according to the type of treatment, which was either one of the following: 1resin infiltration group: icon resin (icon etch; dmg, hamburg, germany). the application of the material was done according to the manufacturer instruction as follows: icon-etch (15%hcl gel) applied first for 2 min, followed by water rinsing and air-drying for 30s. the second step was by application of icon-dry (ethanol) for 30s then air-drying, third was application of iconinfiltrant for 3 min., with light curing of the infiltrant for 40 s, and then treated sample teeth stored in ddw. 2opalustre microabrasion group: opalustre was used (opalustre enamel microabrasion slurry, ultradent, south jordan, utah, usa). in which also applied according to manufacture instruction, abrasive material was applied on the surface of the teeth with mechanical friction performed by a rubber cup at 500 r/min speed, lasting 30 to 40 seconds, followed by water rinsing and air drying. microhardness testing the vicker’s microhardness test (400 series, wilson wolpert, germany) was measured for each tooth of the total sample at the baseline, after white spot lesion formation and after treatment with each material with a diamond indenter made with a 300 g load. three indentations (500 μm apart) were applied on the buccal surfaces, with a dwell time of 15 seconds. indentation was noticed in digital readings, and an average was obtained(24). statistical analysis the data collected was subjected to the statistical package for social science (spss, version 21, chicago, illinois, usa). descriptive statistics as minimum, maximum, mean, standard deviation (sd) was used. the inferential statistics were shapiro wilk levene test and general linear model, the least significant difference (lsd) and bonferroni post hoc test. the level of significance was set at 0.05. partial eta square effect size was: small (0.01-0.059), medium (0.06-0.139), large >=0.14. results j. bagh. coll. dent. vol. 34, no. 1. 2022 al-mamoori and al haidar 47 microhardness is normally distributed among phases, layers and materials using shapiro wilk at p>0.05. at the three different depth groups, the surface microhardness was measured at the baseline, after demineralization and after treatment with the icon and the opalustre, (table 1). the surface microhardness was decreased dramatically after demineralization then it raised again after treatment. there was a significant difference in the microhardness of all the depths of wsl at the different phases of the study. table 1: descriptive and statistical test of microhardness unit (vhn) among phases and groups by layers. while there was a decrease in the hardness in all depth layers after demineralization, a noticeable increase was found after treatment with each of the materials. however, when comparing the effect size between the two materials (icon and the opalustre), it was slightly higher for the icon material than it was for the opalustre, which mean that the resin infiltration was the better in improving the microhardness of teeth after demineralization than the microabrasion. pairwise comparison in table2 shows a statistical significant difference between each phase of the study in all the depth layers and for both of the materials except in outer enamel layer in opalustre material between baseline and after treatment, the result was not significant. discussion dental caries prevention techniques primarily attempt to arrest caries and to remineralize the affected dental surface in its early phases. in fact, using preventive materials to treat the initial decay and white lesions on the enamels will slow or avoid the cavity growth and maintain the tooth structure. initial enamel lesions can be treated and their acidity resistance can be increased with specially devised treatlayers phases material resin infiltration opalustre microabrasion minimum maximum mean ±sd minimum maximum mean ±sd outer enamel base line 257.320 487.210 362.534 70.181 220.700 438.200 344.786 79.370 demin. 188.570 280.040 232.499 32.086 126.500 299.700 233.058 58.228 after treatment 227.600 378.600 315.663 53.721 201.300 393.700 319.428 76.692 statistics f 25.820 20.711 p value 0.00000* 0.00000* inner enamel base line 235.060 428.100 344.924 64.885 272.700 473.500 336.810 61.475 demin. 125.700 238.300 187.476 32.001 143.600 239.700 187.995 28.312 after treatment 217.400 398.500 298.858 70.708 236.400 361.500 284.416 39.563 statistics f 38.810 33.851 p value 0.00000* 0.00000* outer dentine base line 275.600 407.280 339.549 52.426 242.470 453.160 348.296 60.608 demin. 128.700 238.300 174.161 32.798 156.280 210.900 179.724 17.978 after treatment 256.220 360.760 299.648 40.197 205.680 349.600 279.584 50.466 statistics f 44.695 43.619 p value 0.00000* 0.00000* *=significant at p≤0.05. j. bagh. coll. dent. vol. 34, no. 1. 2022 al-mamoori and al haidar 48 ment regimens (25). incipient lesions have reduced microhardness than that of the sound and caries-free enamel surface. the process of chemical dissolving of enamel rods weakens the enamel and generates voids, resulting in a loss in microhardness after demineralization (26,27). table 2: multiple comparisons of microhardness unit (vhn) between different study phases according to lesion depth and study materials. *=significant at p≤0.05, ^ not significant. microhardness tests are commonly utilized to assess the tooth hardness. this procedure is simple, rapid, and only takes a small part of the sample buccal surface to test. in 2003, gutierrez-salazar and reyes-gasga proposed in tooth hardness studies the vicker indenter is more useful than the knoop’s, so the vickers hardness test was chosen in this study (28). in this study the specimen surfaces were impressed with a diamond indenter made with a 300 g load, three indentations (500 μm apart) for 15 seconds (29,30). the microhardness of the samples treated with resin infiltration was increased. this could be explained as that because of the low viscosity, resin fills the pores between the remaining crystals in the porous lesion, forming a diffusion barrier not only on the surface, but also even within the lesion body, causing the demineralized tissues to reharden and enhance the mechanical strength. the results of this investigation agreed with those of torres et al. (26) and paris et al. (31), who found that resin infiltration improves the mipairwise comparisons measure: vh material layer (i) study phase (j) study phase mean difference (i-j) pvalue resin infiltration outer enamel base line demineralization. 130.035 0.00000 * after treatment 46.871 0.00032 * demineralization. after treatment -83.164 0.00000 * inner enamel base line demineralization. 157.448 0.00000 * after treatment 46.066 0.00040 * demineralization. after treatment -111.381 0.00000* outer dentine base line demineralization. 165.388 0.00000* after treatment 39.901 0.00221* demineralization. after treatment -125.486 0.00000* opalustre microabrasion outer enamel base line demin. 111.729 0.00000* after treatment 25.359 0.07673 ^ demin. after treatment -86.370 0.00000* inner enamel base line demin. 148.815 0.00000* after treatment 52.394 0.00006* demin. after treatment -96.421 0.00000* outer dentine base line demin. 168.573 0.00000* after treatment 68.713 0.00000* demin. after treatment -99.860 0.00000* b. adjustment for multiple comparisons: bonferroni. j. bagh. coll. dent. vol. 34, no. 1. 2022 al-mamoori and al haidar 49 crohardness of the carious lesions when compared to the untreated artificial lesions following demineralization, microhardness was significantly increased when microabrasion techniques were used, indicating that this micro-invasive treatment method was beneficial for the management of incipient caries lesions. although there were insufficient researches on the outcome of the microabrasion on enamel hardness, the procedure has previously demonstrated an increase in enamel microhardness following a microabrasion process, like the finding of vitro research by yazkan's (32). hardness improvement can be explained according to the theory indicating that the acid compound changes the prismatic structure of enamel, causing a compacting effect so therefore increasing the hardness of the teeth (33,34). in this study, when comparing the mean difference between the icon and the opalustre materials, it was found that the mean difference of resin infiltration in the outer enamel between the demineralization and after treatment phases was lower than in opalustre material. however, the mean difference of icon in inner enamel and outer dentine was higher than in opalustre, which mean according to this result the icon material had a better performance in increasing the microhardness. conclusion as of when the depth of the wsl increased the microhardness value decrease accordingly. both resin infiltration and microabrasion were effective in treating wsl and improving the microhardness values of the teeth at different depth of demineralization. conflict of interest: none. references 1. tashima ay, aldrigui jm, bussadori sk, et al. enamel microabrasion in pediatric dent.: case report. conscientiae saude. 2009; 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( المختبر في دراسة (االصطناعية البيضاء البقع آلفات الدقيقة الصالدة على الدقيق والكشط الراتنج العنوان: تأثير 2 اسيل حيدر الحيدر, 1ريم مجيد المعموري الباحثون: المستخلص: والبكتريا الجرثومية الصفيحة تراكم بسبب تظهر قد متعددة اسبابها. السليم السطح أسفل المعادن منزوعة البقع هذه وتكون االسنان في التسوس ظهور عالمات اول من هي البيضاء البقعالخلفية: للبقع المختلفة االعماق في الدقيق والقشط الراتنج مادة بين الصالدة ومقارنة اختبار هو الدراسة من الهدف .الفم نظافة سوء من يعانون الذين الصغار والمراهقين األطفال لدى تطورت التي .البيضاء باستخدام البيضاء البقع لعمق تبعا اساسية مجاميع ثالث الى االسنان تقسيم تم ثم المعادن ازالة محلول باستخدام البشرية الضواحك من سن 48 على البيضاء البقع تكوين تمالعمل: المواد وطرق (. الدقيق اوالقشط الراتنج مادة) العالج نوع حسب مجموعتين الى مجموعة كل تقسيم تم ثم. diagnodent ال قلم .الدقيق والقشط الراتنج بمادة معالجتها بعد االسنان صالدة في زيادة هناك كان حين في االسنان صالدة قلت البيضاء البقع عمق زاد كلما ان االستنتاج يمكنناالنتائج: ahmed final.doc j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 98 pharyngeal airway volume and its relationship to the facial morphology in nasal breathing and mouth breathing subjects (a comparative computerized tomography study) ahmed m. al-mayali, b.d.s. (1) iman i. al-sheakli, b.d.s., m.sc. (2) abstract background: the value of lateral cephalometric radiographs to evaluate the pharyngeal airway is limited because it provided 2-dimensional (2d) images of complex 3-dimensional (3d) anatomic structures. three dimensional analyses of the airway volumes are required to understand oral and pharyngeal adaptations in mouth breathing and nasal breathing subjects. the aim of this study was to measure the pharyngeal airway volume and the size of the face, then compare between pharyngeal airway volume in mouth breathing and nasal breathing subjects and find the gender difference in each group, also to study the relation between pharyngeal airway volume and the size of the face. material and methods: fifty patients including 28 males and 22 females with an age ranged between 18-35 years suffered from clinical symptoms of nasal obstruction and mouth breathing was detected by otolaryngologist and sent to be imaged by brilliance™ 64, philips multi-detector computed tomography. twenty normal subjects (10 males and 10 females) were selected as control. angular and linear variables were measured in addition to the size of the face and the pharyngeal airway volume. results: a statistically significant relationship between the pharyngeal airway volume and the mode of respiration and between pharyngeal airway volume and genders were detected. the pharyngeal airway volume was larger in nasal breathers than in mouth breathers and it was larger in males than in females. the size of the face was larger in males than females. conclusion: ct volumetric images provide more reliable and accurate information for measurement of the pharyngeal airway volume, so the changes in the pharyngeal airway volume can be studied before and after surgery and this will aid in selection of the best treatment option in addition to control the relapse after orthodontic treatment with mouth breathing patients. keyword: pharyngeal airway volume, size of the face, mouth breathing, computerized tomography. (j bagh coll dentistry 2014; 26(3):98-107). introduction after more than a century of conjecture and heated argument, the orthodontic relevance of nasal obstruction and its assumed effect on facial growth continues to be debated. oral respiration disrupts those muscle forces exerted by tongue, cheek and lips upon the maxillary arch. the main characteristics of the respiratory obstruction syndrome are mouth breathing, open-bite, crossbite, excessive anterior face height, incompetent lip posture, excessive appearance of maxillary anterior teeth, narrow external nares and "v" shaped maxillary arch (1). cone-beam computed tomography (cbct) was developed in the 1990 as an evolutionary process resulting from the demand for 3dimensional (3d) information obtained by conventional computed tomography (ct) scans (2). the upper airway analysis, orthodontic and orthognathic surgical planning for patients with significant facial asymmetry has been increasingly performed based on 3d volumes (3-6). (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) assist. professor, department of orthodontics, college of dentistry, university of baghdad. most previous studies of the pharyngeal airway, head posture, malocclusion, as well as facial morphology have been carried out using a two dimensional lateral cephalograms (7,8) . superimposition of the left and right images in the 2d plane projection of a three-dimensional (3d) structure leads to errors and the left-to-right width of the upper airway is not visible in 2d film. for these reasons, it is difficult to obtain precise volume of the pharyngeal airway and to reproduce the soft tissue structures accurately from lateral cephalograms alone (9,10). cbct provides 3d-reconstructed image from multiple sequential planar projection images. it is possible to visualize sites of interest by adjusting the image orientation and rotation. cbct has different gray-level intensities that allow visualization of soft tissue as well as hard tissue with different tissue densities. it also allows visualization of internal anatomic structures such as the airway independently by eliminating external structures (11,12). furthermore, cbct allows linear, angular, and planar as well as volumetric analyses (13). j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 99 materials and methods sample the sample is composed of ct images for iraqi adult patients who were attending al-sader medical city in al-najaf governorateent department from march 2013 till august 2013. only 50 subjects out of 427 individuals (28 males and 22 females with an age ranged between 18-35years were selected when met a special criteria. they sent by otolaryngologist specialist with a special sending request to the al-furat center for neuromedicine science / computerized tomography department because of clinical symptoms of nasal obstruction and mouth breathing to be imaged by high resolution computerized tomography scanning of the paranasal sinuses that extended to hyoid bone to visualize pharyngeal air way space. the control group was 20 subjects out of 98 in the same age group and also had been examined and identified by the otolaryngologist specialist in al-sader medical city as having no nasal obstruction, all the control group had class i molar relationship according to angle's classification and class i canine relationship. also they were class i skeletally through the clinical examination was determined by two fingers method (14). method each patient attained to the otolaryngology consultant clinic examined by the otolaryngologist specialist to include or exclude any nasal obstruction. this was done by the same otolaryngologist specialist by using head mirror, speculum and flexible nasofibroscopy. the orthodontist asked each subject about name, age, origin, nationality, occupation, address, past medical history, family history and past dental history. each patient from the control group was examined to diagnose the skeletal relationship of the upper and lower jaws and the molar and canine relationship. each patient had a written request with appropriate clinical history. the patients were informed about the study and consent to participate in this study was taken. the chronological age was determined accurately by the period from the birth date to the radiographic exposure date. all these information were documented in formulated case sheet, then a clinical examination was executed to confirm the special sample criteria. mouth or nose breathing is recorded subjectively by holding a cold dental mirror in front of the nose and mouth as the patient sits in relaxed position to observe a misting pattern on a cold surface of dental mirror (15). then the patients were sent with a written request to the ct scan department to taking ct scan image. during that, the subject was asked to swallow to bring the dentitions into maximum interdigitation, informed not to move his head to either side and to cut breathing and swallowing during the acquisition to minimize measurement errors. after that, a topogram and a lateral view of the head show the vertex to the 4th cervical vertebrae was obtained and followed by selecting the desired scan range of the sinuses. angular measurements the following angular measurements were done on 2d cephalogram (16): • sna: anteroposterior position of maxilla in relation to the anterior cranial base. • snb: anteroposterior position of mandible in relation to the anterior cranial base. • anb: relative anteroposterior position of the maxilla to the mandible. • saddle angle (n-s-ar): the angle between the anterior &posterior cranial base. size of the face the size of the face was established from the p-a and lateral synthetic cephalograms as a rectangular prism encompassing the facial bones. (a) with edges as cube, (b) the bizygomatic width projected on x-axis, (c) the n-me distance projected on the y-axis and (d) the ba-ans distance projected on the z-axis (18) (figure1). j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 100 (a) (c) (b) (d) figure 1: establishment the size of the face three dimensional model of the pharyngeal airway volume the limits for airway analysis are (4): • anterior: a vertical plane through posterior nasal spine perpendicular to the sagittal plane at the lowest border of the vomer. • posterior: the posterior wall of the pharynx. • lateral: the lateral walls of the pharynx, including the full extensions of the lateral projections. • lower: a plane tangent to the most caudal medial projection of the third cervical vertebra perpendicular to the sagittal plane. • upper: the highest point of the nasopharynx, coinciding with the posterior choanae and consistent with the anterior limit. once segmented, airways were refined to obtain the true shape of the airway by eliminating the projections that did not belong to the airway then the volumes were measured in cm3 with the measuring tool (figure 2). figure 2: three dimensional model of the pharyngeal airway volume results angular measurements the mean differences between males and females nasal breather subjects expressed significant difference in sna and snb, female higher than male (table 1). j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 101 there are no significant correlation between pharyngeal airway volume & the angular measurements in both groups and gender except in female mouth breather that show significant correlation in sna and anb angle (table 6). linear measurements the mean differences between males and females nasal breather subjects expressed significant differences between genders in bizygomatic width, ba-ans ,n-me and uafh, male higher than female (table 1) . the mean differences between males and females mouth breather subjects expressed significant differences between genders in bizygomatic width, ba-ans, n-me, uafh and lafh, male higher than female (table 2). the mean differences between nasal and mouth breather male subjects expressed significant differences in n-me and lafh, mouth breather higher than nasal breather, (table 3). the mean differences between nasal and mouth breather female subjects expressed significant differences in lafh, mouth breather higher than nasal breather (table 4). the mean differences between nasal and mouth breather total sample expressed significant differences between two groups in n-me, uafh and lafh. it was shown that mouth breathers are higher than nasal breather in n-me and lafh and nasal breathers are higher than mouth breathers in uafh, (table 5). there are significant correlation between pharyngeal airway & the linear measurements in both groups and gender (table 6). size of the face the mean differences between males and females nasal breather subjects expressed highly significant differences between genders in the size of the face, male higher than female (table 1) . the mean differences between males and females mouth breather subjects expressed highly significant differences between genders in the size of the face, male higher than female (table 2). the mean differences between nasal and mouth breather male subjects expressed significant differences in the size of the face, mouth breather higher than nasal breather (table 3). there are significant correlation between pharyngeal airway & size of the face in male nasal and mouth breather and in the total sample (table 6). pharyngeal air way volume the mean differences between males and females nasal breather subjects expressed highly significant differences in pharyngeal air way volume, male higher than female (table 1) . the mean differences between males and females mouth breather subjects expressed significant differences between genders in pharyngeal air way volume, male higher than female (table 2). the mean differences between nasal and mouth breather male subjects expressed significant differences in pharyngeal air way volume nasal breather higher than mouth breather (table 3) the mean differences between nasal and mouth breather female subjects expressed significant differences in pharyngeal air way volume, nasal breather higher than mouth breather (table 4). the mean differences between nasal & mouth breather total sample expressed significant differences in pharyngeal air way volume, nasal breather higher than mouth breather (table 5). discussion angular measurements for the sna and snb angles, the female nasal breathers had a higher value than male nasal breathers. the sna angle was highly significant at p < 0.006 and the snb angle was significant at p < 0.029. the possible difference in the mean of sna between males and females is the more anterior position of point n in males than females. the anterior position of point n in males was reported by previous studies (17,18). the results expressed no significant genders differences in mouth breathers also there were no significant differences between nasal and mouth breathers. this result is in agreement with previous studies that concern with the relationship between facial prognathism and respiratory resistance and found no correlation between nasal respiratory resistance and sna or snb angles (19,20). since the maxilla is a fixed bone and attached to two cranial bones (frontal and ethmoid bones) and seven facial bones (nasal, zygoma, lacrimal, inferior turbinate, palate, vomer and it fellow on the opposite side). the effect of muscular imbalance on the maxilla is decreased (21). the result disagrees with the finding of sassouni et al. study that found the reduction in airway space will be associated with retrognathic maxilla (22). the result showed no significant differences between genders in anb angle in nasal breather j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 102 & mouth breather group. this comes in agreement with trask et al. study (23). also the result is in agreement with a solow et al. study that found no significant correlation between airway adequacy and maxillary prognathism (24). on the other hand, the reduction of the nasopharyngeal airway has no effect on the sagittal jaw relationship. this result agrees with previous studies (19,25,26). the most probable explanation is that reduced nasopharyngeal airway and the possible subsequent mouth breathing affect both jaw, thus the anb angle is not affected. but the result disagrees with ung et al. who found that anb angle had a higher value in the nasally obstructed sample than the normal group (27). regarding the saddle angle, there was no significant gender difference in nasal and mouth breathers; this result agrees with ali (28) and alsahaf (29). linear measurements males and females nasal breather and mouth breather results expressed significant gender differences in bi-zygomatic width, ba-ans, nme, uafh and lafh being males higher than females. these results indicated that the males possessed larger facial dimensions than females. this finding was supported by al-sahaf who found significant gender differences in all dimensional measurement and in all skeletal classes (29). there are significant differences between nasal breather & mouth breather group in n-me, uafh and lafh, nasal breather higher than mouth breather in uafh, mouth breather higher than nasal breather in n-me and lafh. for the facial height the results showed that for the uafh for the nasal breather group had a higher mean than mouth breather groups in which it was significant at p < 0.002 for the comparison between nasal breather and mouth breather group; this comes in agreement with kesso that found the uafh for the nasal breather group had a higher mean than the mouth breather group (30). but this result disagreement with trask et al. who found no difference in upper facial height between long faces and control subjects (31) for the lafh and total afh, the mean was higher for the mouth breather group than in the nasal breather group. this may be due to the backward rotation of the mandible (31,32) . on the other hand, the present result comes in agreement with kesso, tourne and zain alabedin who found an increase in the lower facial height (30,33,34) the higher mean value of these measurements in mouth breather group subjects is more than that in nasal breather group may be due to the fact that the increased mandibular plane and maxillamandibular planes angles in mouth breathing subject lead to increase in afh and lfh (16). the finding of this study disagrees with martin et al. who reported that a lack of a consistent relationship between nasal resistance and dentofacial morphology (35). theoretically, the maintenance of vital pharyngeal airway necessitates lowering of the tongue, the soft palate and the mandible. this brings for the dorsal rotation of the mandible or at least ramus resulting in increasing anterior facial height (36). the prolonged buccal respiration is followed by increase in extrusion of the posterior teeth causing increased anterior facial height (37). size of the face the size of the face was established as a rectangular prism encompassing the facial bones. the average size of the face was statistically significantly larger in the males than in the females. the size of the face was significantly correlated with gender. these result come in agreement with al-sahaf, trenouth et al. and genecov et al. (29,38,39). pharyngeal airway volume was significantly correlated with face size. subjects with larger faces would be expected to have larger airway volumes and this comes in agreement with gruer et al. (4) . pharyngeal air way volume there was significant gender difference in both groups being males had higher mean values than females. linder-aronson and leighton and martin et al. found sexual dimorphism during growth of the posterior wall of the pharynx (40,41) . airway volume differed significantly for male and female being the female volume smaller which came in agreement with gruer et al.(4) . the mean volume of the pharyngeal airway in males, females and total sample was higher in nasal breathers than mouth breathers. the mean of the pharyngeal airway volume in nasal breather was 20.4 cm3 and the mean of the pharyngeal airway volume in mouth breather was 15.9 cm3. this result comes in agreement with vandana et al. (42). it is quite likely that 3-d images of the airway will allow an improved evaluation of sites of airway obstruction and an improved understanding of the physiologic response to pharyngeal stenosis. it already is possible to use the cranial base surface to superimpose 3-d j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 103 models for different time points within the same patient, so that changes in airway volume and orientation relative to this stable reference can be studied before and after surgery (43). references 1. lopatiene' k, babarskas. a malocclusion and upper airway obstruction. medicina 2002; 38(3): e59-e65 (http://medicinakmu.tt). 2. kau ch, richmond s, palomo jm, hans mg. threedimensional cone beam computerized tomography in orthodontics. j orthod 2005; 32: 282-93. 3. ogawa t, enciso r, shintaku wh, clark gt. evaluation of crosssection airway configuration of obstructive sleep apnea. oral surg oral med oral pathol oral radiol endod 2007; 103:102-8. 4. grauer d, cevidanes lh, styner ma, ackerman jl, proffit wr. pharyngeal airway volume and shape from cone-beam computed tomography: relationship to facial morphology. am j orthod dentofacial orthop 2009; 136: 805-14. 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40. linder-aronson s, leighton bc. : a longitudinal study of the development of the posterior nasopharyngeal wall between 3 and 16 years of age. eur j orthod 1983; 5: 47-58. 41. martin o, muelas l, vinas mj. nasopharyngeal cephalometric study of ideal occlusions. am j orthod dentofacial orthop 2006; 130: 436. 42. katyal v, pamula y, daynes cn, martin j, et al. ame j orthod dentofac orthop 2013; 144(6): 860-71. 43. cevidanes lh, styner ma, proffit wr. image analysis and superimposition of 3-dimensional conebeam computed tomography models. am j orthod dentofac orthop 2006; 129: 611-8. table 1: descriptive statistics and genders difference in nasal breathers group variables genders descriptive statistics gender difference n mean s.d. s.e. t-test p-value a ngular m easurem ents (º) sna males 10 83.70 1.25 0.40 -3.111 0.006 (hs) females 10 85.90 1.85 0.59 total 20 84.80 1.91 0.43 snb males 10 80.80 1.75 0.55 -2.368 0.029 (s) females 10 82.60 1.65 0.52 total 20 81.70 1.89 0.42 anb males 10 2.90 0.88 0.28 -1.144 0.268 (ns) females 10 3.30 0.67 0.21 total 20 3.10 0.79 0.18 saddle angle males 10 119 3.65 1.15 0 1 (ns) females 10 119 4.71 1.49 total 20 119 4.10 0.92 l inear m easurem ents (m m .) bi-zygomatic width males 10 126.74 5.97 1.89 3.251 0.004 (hs) females 10 119.32 4.06 1.28 total 20 123.03 6.26 1.40 ba-ans males 10 98.63 4.89 1.55 2.606 0.018 (s) females 10 93.03 4.72 1.49 total 20 95.83 5.49 1.23 n-me males 10 115.50 6.19 1.96 2.383 0.028 (s) females 10 109.11 5.79 1.83 total 20 112.31 6.69 1.50 uafh males 10 56.49 3.30 1.04 2.742 0.013 (s) females 10 52.95 2.40 0.76 total 20 54.72 3.35 0.75 lafh males 10 59.01 3.39 1.07 1.803 0.088 (ns) females 10 56.16 3.67 1.16 total 20 57.59 3.74 0.84 size (cm3) size of the face males 10 1450.93 188.11 59.49 3.230 0.005 (hs) females 10 1213.82 136.01 43.01 total 20 1332.38 200.79 44.89 volume (cm3) pa males 10 22.49 2.88 0.91 4.436 0.000 (hs) females 10 18.30 0.77 0.24 total 20 20.40 2.97 0.67 j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 105 table 2: descriptive statistics and genders difference in mouth breathers group variables genders descriptive statistics gender difference n mean s.d. s.e. t-test p-value a ngular m easurem ents (º) sna males 28 85.68 3.01 0.57 0.634 0.529 (ns) females 22 85.14 3.00 0.64 total 50 85.44 2.98 0.42 snb males 28 81.86 3.03 0.57 -0.067 0.947 (ns) females 22 81.91 2.31 0.49 total 50 81.88 2.71 0.38 anb males 28 3.82 2.92 0.55 0.687 0.495 (ns) females 22 3.23 3.18 0.68 total 50 3.56 3.02 0.43 saddle angle males 28 118.04 4.44 0.84 0.444 0.659 (ns) females 22 117.50 3.96 0.84 total 50 117.80 4.20 0.59 l inear m easurem ents (m m .) bi-zygomatic width males 28 128.87 6.11 1.15 5.882 0.000 (hs) females 22 119.44 4.94 1.05 total 50 124.72 7.31 1.03 ba-ans males 28 100.15 4.90 0.93 8.009 0.000 (hs) females 22 88.87 5.00 1.07 total 50 95.19 7.48 1.06 n-me males 28 123.93 8.21 1.55 5.550 0.000 (hs) females 22 112.33 6.03 1.29 total 50 118.83 9.30 1.32 uafh males 28 53.08 4.18 0.79 3.854 0.000 (hs) females 22 49.14 2.64 0.56 total 50 51.34 4.07 0.58 lafh males 28 70.86 6.55 1.24 4.464 0.000 (hs) females 22 63.17 5.33 1.14 total 50 67.47 7.12 1.01 size (cm3) size of the face males 28 1599.85 151.32 28.59 9.533 0.000 (hs) females 22 1196.23 145.06 30.93 total 50 1422.26 250.19 35.38 volume (cm3) pa males 28 17.40 5.61 1.06 2.614 0.012 (s) females 22 14.04 2.45 0.52 total 50 15.92 4.77 0.67 j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 106 table 3: descriptive statistics and group difference in male group variables groups descriptive statistics group difference n mean s.d. s.e. t-test p-value a ngular m easurem ents (º) sna nb 10 83.70 1.25 0.40 -2.005 0.052 (ns) mb 28 85.68 3.01 0.57 snb nb 10 80.80 1.75 0.55 -1.038 0.306 (ns) mb 28 81.86 3.03 0.57 anb nb 10 2.90 0.88 0.28 -0.975 0.336 (ns) mb 28 3.82 2.92 0.55 saddle angle nb 10 119.00 3.65 1.15 0.615 0.543 (ns) mb 28 118.04 4.44 0.84 l inear m easurem ents (m m .) bi-zygomatic width nb 10 126.74 5.97 1.89 -0.953 0.347 (ns) mb 28 128.87 6.11 1.15 ba-ans nb 10 98.63 4.89 1.55 -0.842 0.405 (ns) mb 28 100.15 4.90 0.93 n-me nb 10 115.50 6.19 1.96 -2.952 0.006 (hs) mb 28 123.93 8.21 1.55 uafh nb 10 56.49 3.30 1.04 2.327 0.026 (s) mb 28 53.08 4.18 0.79 lafh nb 10 59.01 3.39 1.07 -5.435 0.000 (hs) mb 28 70.86 6.55 1.24 size (cm3) size of the face nb 10 1450.93 188.11 59.49 -2.506 0.017 (s) mb 28 1599.85 151.32 28.59 volume (cm3) pa nb 10 22.49 2.88 0.91 2.727 0.010 (hs) mb 28 17.40 5.61 1.06 table 4: descriptive statistics and group difference in female group variables groups descriptive statistics group difference n mean s.d. s.e. t-test p-value a ngular m easurem ents (º) sna nb 10 85.90 1.85 0.59 0.740 0.465 (ns) mb 22 85.14 3.00 0.64 snb nb 10 82.60 1.65 0.52 0.850 0.402 (ns) mb 22 81.91 2.31 0.49 anb nb 10 3.30 0.67 0.21 0.071 0.944 (ns) mb 22 3.23 3.18 0.68 saddle angle nb 10 119.00 4.71 1.49 0.936 0.357 (ns) mb 22 117.50 3.96 0.84 l inear m easurem ents (m m .) bi-zygomatic width nb 10 119.32 4.06 1.28 -0.068 0.947 (ns) mb 22 119.44 4.94 1.05 ba-ans nb 10 93.03 4.72 1.49 2.221 0.034 (s) mb 22 88.87 5.00 1.07 n-me nb 10 109.11 5.79 1.83 -1.417 0.167 (ns) mb 22 112.33 6.03 1.29 uafh nb 10 52.95 2.40 0.76 3.886 0.001 (hs) mb 22 49.14 2.64 0.56 lafh nb 10 56.16 3.67 1.16 -3.753 0.001 (hs) mb 22 63.17 5.33 1.14 size (cm3) size of the face nb 10 1213.82 136.01 43.01 0.324 0.748 (ns) mb 22 1196.23 145.06 30.93 volume (cm3) pa nb 10 18.30 0.77 0.24 5.337 0.000 (hs) mb 22 14.04 2.45 0.52 j bagh college dentistry vol. 26(3), september 2014 pharyngeal airway orthodontics, pedodontics and preventive dentistry 107 table 5: descriptive statistics and group difference in total sample variables groups descriptive statistics group difference n mean s.d. s.e. t-test p-value a ngular m easurem ents (º) sna nb 20 84.80 1.91 0.43 -0.887 0.378 (ns) mb 50 85.44 2.98 0.42 snb nb 20 81.70 1.89 0.42 -0.271 0.787 (ns) mb 50 81.88 2.71 0.38 anb nb 20 3.10 0.79 0.18 -0.670 0.505 (ns) mb 50 3.56 3.02 0.43 saddle angle nb 20 119.00 4.10 0.92 1.086 0.281 (ns) mb 50 117.80 4.20 0.59 l inear m easurem ents (m m .) bi-zygomatic width nb 20 123.03 6.26 1.40 -0.910 0.366 (ns) mb 50 124.72 7.31 1.03 ba-ans nb 20 95.83 5.49 1.23 0.349 0.728 (ns) mb 50 95.19 7.48 1.06 n-me nb 20 112.31 6.69 1.50 -2.849 0.006 (hs) mb 50 118.83 9.30 1.32 uafh nb 20 54.72 3.35 0.75 3.290 0.002 (hs) mb 50 51.34 4.07 0.58 lafh nb 20 57.59 3.74 0.84 -5.879 0.000 (hs) mb 50 67.47 7.12 1.01 size (cm3) size of the face nb 20 1332.38 200.79 44.89 -1.431 0.157 (ns) mb 50 1422.26 250.19 35.38 volume (cm3) pa nb 20 20.40 2.97 0.67 3.894 0.000 (hs) mb 50 15.92 4.77 0.67 table 6: correlation between pa and other variables in both groups and genders variables nb mb males females total males females total a ngular m easurem ents (º) sna r 0.156 0.317 -0.342 -0.359 0.509 -0.090 p-value 0.667 (ns) 0.372 (ns) 0.140 (ns) 0.061 (ns) 0.016 (s) 0.536 (ns) snb r 0.312 0.383 -0.179 -0.053 -0.093 -0.059 p-value 0.380 (ns) 0.274 (ns) 0.451 (ns) 0.790 (ns) 0.681 (ns) 0.684 (ns) anb r -0.401 -0.064 -0.399 -0.315 0.547 -0.036 p-value 0.251(ns) 0.861(ns) 0.081 (ns) 0.103 (ns) 0.008 (hs) 0.806 (ns) saddle angle r -0.188 -0.213 -0.107 -0.095 0.177 -0.006 p-value 0.603 (ns) 0.555 (ns) 0.654 (ns) 0.630 (ns) 0.432 (ns) 0.967 (ns) l inear m easurem ents (m m .) bi-zygomatic width r 0.971 0.484 0.903 0.402 -0.129 0.427 p-value 0.000 (hs) 0.157 (ns) 0.000 (hs) 0.034 (s) 0.567 (ns) 0.002 (hs) ba-ans r 0.626 0.558 0.694 0.113 0.490 0.387 p-value 0.053 (ns) 0.094 (ns) 0.001 (hs) 0.568 (ns) 0.021(s) 0.006 (hs) n-me r 0.761 -0.147 0.661 0.232 0.134 0.373 p-value 0.011 (s) 0.685 (ns) 0.001 (hs) 0.235 (ns) 0.552 (ns) 0.008 (hs) uafh r 0.546 -0.172 0.625 0.311 0.570 0.460 p-value 0.103 (ns) 0.636 (ns) 0.003 (hs) 0.108 (ns) 0.006 (hs) 0.001 (hs) lafh r 0.858 -0.120 0.625 0.092 -0.130 0.224 p-value 0.002 (hs) 0.741 (ns) 0.003 (hs) 0.643 (ns) 0.565 (ns) 0.117 (ns) size (cm3) size of the face r 0.880 0.349 0.846 0.407 0.238 0.476 p-value 0.001 (hs) 0.323 (ns) 0.000 (hs) 0.032 (s) 0.286 (ns) 0.000 (hs) p > 0.05 non-significant , 0.05 ≥ p > 0.01 significant , p ≤ 0.01 highly significant j bagh college dentistry vol. 29(1), march 2017 oral health status pedodontics, orthodontics and preventive dentistry 117 oral health status in relation to nutritional status among institutionalized autistic children and adolescents in baghdad city, iraq ali hadi f. al-fatlawi, b.d.s., m.sc. (1) nada jafer mh. radhi, b.d.s., m.sc., ph.d. (2) abstract background: the autism spectrum disorder (asd) describes a wide range of symptoms, including difficulty with social interaction and communication skills. controversial thinking about oral health of children with asd, in general may have a lower hygiene level than healthy individuals, low caries rate and high body weight in comparison to healthy children. this study was conducted to assess the oral health status in relation to nutritional status among institutionalized autistic children and adolescents. materials and methods: from 12 institutes in baghdad, the study group contained 364 child and adolescent with asd (male= 294, female=70), while control group included 441 normal child and adolescent (male=357, female=84) from primary and secondary schools. the age range (6-15) years old categorized to two age groups, children age group (6-10) years and adolescents age group (11-15) years. decayed, missing and filled surfaces (dmfs, dmfs), plaque (pli), gingival (gi) and calculus (ci) indices were used to measure oral health status for both groups. assessment of nutritional status performed by using bmi for age z-score value. the data of current study was analyzed using spss version 21. results: mean rank values of (dmfs, dmfs) were lower in study group than control group with high significant differences. the mean rank values of pli, gi, and ci in study group were found to be higher than control group with high significant differences. a moderate positive high significant correlation was found between ds, dmfs, ds, dmfs and pli, gi, ci in both groups. the mean rank values of body mass index (bmi) for age z-score were higher in study group than control group. very weak negative high significant correlation between bmi for age z-score and ds, dmfs, ds, dmfs in study group. conclusion: dental caries severity, oral hygiene and gingival health were lower in asd group than control group. dental caries severity was related to oral health status in both groups. possible of overweight, overweight and obesity were most common in children and adolescents with asd than control group. body weight of autistic children was related to dental caries severity. keywords: autism spectrum disorder; dmfs; body mass index; oral hygiene. (j bagh coll dentistry 2017; 29(1): 117124) introduction 1the term autism spectrum disorders (asd) refers to a group of neurodevelopmental conditions defined by impairment in three areas: social interaction, communication and a stereotyped, restricted or repetitive pattern of behavior, interests and activities (1). the etiology of asd is a mystery. highly regarded researchers are of the opinion that there is probably more than one cause since the disorder can have such disparate manifestations. genetics, environmental poisons, neurologic psychopathy, dietary deficiencies, and allergies have all been implicated (2). patients with asd do not present very specific oral disorders. they pose the greatest challenge for dentists, due to their complex and varied clinical manifestations. previous studies have shown that the child with autism had poorer oral hygiene and increased periodontal disease (3,4). maintaining good oral (1) ph.d. student, department of pediatric and preventive dentistry, college of dentistry, baghdad university. (2) assist. professor, department of pediatric and preventive dentistry, college of dentistry, baghdad university. hygiene in children with autism is a significant task for both the parents or caregivers of the child, and dental staff (4). other studies reported no statistically significant differences in the prevalence of caries, gingivitis and degree of oral hygiene in comparison with non-autistic individuals (5,6). loo cy et al., have demonstrated that the patients with asd were more likely to be cariesfree and have lower decayed, missing and filled teeth (dmft) scores than controls (7). the most common way of measuring obesity is the body mass index (bmi). the bmi represent the weight levels associated with the lowest overall risk to health and is an indicator of overall adiposity (8). studies have been conducted to assess the association of the bmi and oral health. however, a study has even observed a significant association between caries frequency and bmi (9), whereas another study found no correlation between dental decay in obese and non-obese children (10). the relationship between bmi and oral health status is clearly rather complex. a low bmi is easily explainable on the basis of there being real functional difficulties that can prevent normal j bagh college dentistry vol. 29(1), march 2017 oral health status pedodontics, orthodontics and preventive dentistry 118 eating in some cases. the association of poor oral health with high bmi is likely to be associated with the quality of the diet (11). iraqi study showed more than half of children with autism were overweight/obese. males affected more commonly than females. no significant association between type of feeding during first six months of life, age at weaning and signs of hungry with nutritional status of autistic children. all the underweight autistic children had history of feeding problems like selective food by either type or texture, behavioral problems during feeding, food allergy and diarrhea. the overweight autistic children had history of sitting position during feeding, more than three meals per day, and more than 30 minutes duration of meal (12). only a few studies have reported data on weight status of children with asds. several studies have found varying prevalence of obesity in children and adolescents. the results from these studies suggest that the prevalence of obesity in children and adolescents with asd may be as high as, if not higher than, the general population (13,14). there was no previous study in iraq regarding the nutritional status for autistic children in relation to oral health status. for this reason, this study was designed. materials and methods the study group included 364 children with asd (males= 294, females=70),they represent all autistic children from 12 institutes in baghdad, while control group included 441 normal from school record children selected randomly (males=357, females=84) from primary and secondary schools selected from places near institutions of autism in baghdad. the age range 6-15 years old categorized to two age groups, 6-10 years and 11-15 years. caries experience for each institutionalized autistic children and normal healthy schoolchildren measured through the application of decayed, missing and filled teeth and surfaces indices (dmft, dmfs) and (dmft, dmfs) for permanent and primary teeth according to criteria of who (15). oral hygiene status evaluated by application plaque index (pli) of silness and löe (16), and calculus index (ci) of ramfjord (17). gingival inflammation assessed by using gingival index (gi) of löe and silness (18). assessment of nutritional status performed by using bmi for age z-score value, which recommended by using a -2sd cut off point which represents purely statistical separation of malnourished from wellnourished; therefore, the present study depend this cut off point for the nutritional status indicator (19). by using spss 21 version (statistical package for social sciences), frequency distribution for selected variables was done first. the statistical significance, direction and strength of linear correlation between two quantitative normally variables, one of which being non-normally distributed was measured by spearman’s rank linear correlation coefficient. p value less than the 0.05 level of significance was considered statistically significant. all analyzed tests were bilateral. results table 1 and table 2 show caries-experience (median and mean rank values of ds, ms, fs and dmfs) and (median and mean rank of ds, ms, fs and dmfs) among study and control groups by age and gender respectively. the mean rank values for all components of dmfs and dmfs were higher in 6-10 years age group than 11-15 years age group and higher in male than female. the mean rank values of the total sample for all components of dmfs and dmfs in control group were higher than study group. mann-whitney test was used to compare between study and control groups. the result recorded that components of dmfs and dmfs represented by mean rank were highly significant higher among control group than study group. for components of dmfs (z= -8.93 for ds, -4.98 for ms, -5.79 for fs, -10.12 for dmfs), for component of dmfs (z= -10.02 for ds, -5.06 for ms, -3.18 for fs, 10.16 for dmfs), as p<0.001 for all these differences. table 3 illustrates the median and mean rank values of plaque, gingival and calculus indices among study and control groups by age groups and gender. the mean rank values of plaque, gingival and calculus indices in study group were found to be higher than control group with high statistical significant differences (z= -14.33 for pli; z= -13.78 for gi; z= -9.5 for ci; p<0.001 for all indices). the correlation coefficient between cariesexperience of primary and permanent teeth with pli, gi and ci among study and control group is seen in table 4. a moderate positive high significant correlation was recorded between ds, dmfs, ds, dmfs and pli, gi, ci in both groups, except there is a weak positive high significant correlation was revealed between ds, dmfs, ds, dmfs and ci in control group. the distribution of children according to bmi for age zscore indicator among study and control groups by age and gender is shown in j bagh college dentistry vol. 29(1), march 2017 oral health status pedodontics, orthodontics and preventive dentistry 119 table 5. in 6-10 years age group and total sample, the percentages of possible risk of overweight, overweight and obese categories were found higher in study group than control group while, the percentages of acceptable, wasting and severe wasting categories were found higher in control group than study group. in 11-15 years age group, the percentages of acceptable, possible risk of overweight, overweight and obese categories were found higher in study group than control group, while the percentages of wasting and severe wasting categories were found higher in control group than study group. in study group, all categories of bmi for age z-score indicator were higher in males than females except the acceptable category higher in females than males. table 6 shows median and mean rank of bmi for age z-score among study and control groups by age groups and gender. the mean rank values of bmi for age z-score were higher in study group than control group in both age groups and total sample. high significant differences were found in males (mann-whitney= 4496, z= 3.20) and total sample of 11-15 years age group (mann-whitney= 6611, z= -3.21), in addition to males (mann-whitney= 113334, z= -6.34) and total sample of study (mann-whitney= 170178, z= -6.97), p<0.001 for all these significant differences. in study group, mean rank values for males were higher than females. table 7 demonstrates a very weak negative high significant correlation between bmi for age z-score and ds, dmfs in study group. table 8 illustrates a very weak correlation between bmi for age z-score and pii, gi, ci among study and control groups. a high significant relation (p<0.01) was recorded between bmi for age zscore and pli, and a significant relation (p<0.05) with gi in study group. disscusion the dietary intakes of macronutrients and some micronutrients in children with asd have been found to be lower, higher, or similar compared with the recommended amounts (20). studies investigating nutrient intake in children with asd have produced conflicting results (20,21). a high rate of obesity has been observed among these children (22). kopyckakedzierawski and auinger found that children with asd have a lower hygiene level than healthy individuals, but have a comparable caries rate (23). results of the current study showed that the prevalence and severity of dental caries for primary and permanent teeth were lower among study group compared to control group. this could be due to good home and institutional care by the autistics’ parents or caregivers and a less cariogenic diet. in addition, children with autism because of their ritualistic behavior, which characterized by unvarying pattern of daily activities, such as an unchanging menu, so they are more regular in their behavior at meals than are unaffected children. therefore, a lower frequency of snacking between meals and lower intake of carbohydrates could have contributed to the lower caries rate observed (24,25). this result was in line with several studies (26,27,28), and in contrast with other studies (29,30). in the present study, all the values of pli, gi and ci were higher in the study group than control group with highly significant differences. this finding could be related to many reasons such as the irregular brushing habits because of the difficulties the trainers and the parents encountered when they brushed the children's teeth. it could also be due to lack of the necessary manual dexterity of autistic children during brushing by themselves, which made their tooth brushing inefficient. iraqi study by rasheed showed gi value lower in asd group than healthy group with no statistical significant difference (28). the result of the current study in line with many studies (31,32,33). in this study, the mean rank values of bmi for age z-score were higher in study group than control group in both age groups and total sample. mean rank values for males were higher than females. these findings in agreement with many studies (34,35,36). although food selectivity might be expected to limit intake and result in inadequate weight gain, but the higher intake levels of energy dense foods (juice, sweetened non-dairy beverages and snacks) and lower intake of fruits and vegetables in children with asd compared to typically developing children would be associated differentially with bmi zscore across groups. children with asd may have atypical physical activity and eating patterns that are uniquely associated with the development of obesity (37). there is very limited studies related bmi of 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2015; 3: 11 p. 37. vanvuchelen m, roeyers h, de weerdt w. nature of motor imitation problems in school-aged boys with autism: a motor or a cognitive problem? autism 2007; 11: 225–240. 38. batista lrv, moreira eam, corso act. food, nutritional status and oral condition of the child. rev nutr 2007; 20(2): 191–6. 39. xavier a, bastos r, arakawa a, caldana m, bastos j. correlation between dental caries and nutritional status: preschool children in a brazilian municipality. rev odontol 2013; 42(5): 378–383. 40. panwar nk, mohan a, arora r, gupta a, marya cm, dhingra s. study on relationship between the nutritional status and dental caries in 8-12 year old children of udaipur city, india. kathmandu univ med j 2014; 45(1): 26–31. table 1: caries-experience (median and mean rank) of ds, ms, fs, and dmfs of primary teeth among study and control groups by age and gender. * significant, ** highly significant (higher), between study group and control group, m=median g r o u p s a g e (y e a r ) g e n d e r ds ms fs dmfs m mean rank m mean rank m mean rank m mean rank s tu d y 6 -1 0 m 3 168.35 0 201.06 0 203.76 3 162.47 f 3 46.14 0 53.94 0 53.81 4 45.08 t 3 214.05 0 254.46 0 257.12 4 206.84 1 1 -1 5 m 0 103.73 0 111.70 0 105.06 0 101.33 f 0 22.23 0 22.00 0 22.15 0 21.18 t 0 125.52 0 133.19 0 126.77 0 121.96 a ll m 2 282.06 0 312.03 0 308.37 2 276.28 f 2 69.27 0 75.42 0 75.48 3 68.08 t 2 351.09 0 386.92 0 383.45 2 343.77 c o n tr o l 6 -1 0 m 6 253.89** 0 227.26** 0 225.06** 8 258.69** f 5 65.16** 0 58.64 0 58.75 6 66.05** t 6 318.54** 0 285.45** 0 283.28** 8 324.44** 1 1 -1 5 m 0 116.14* 0 109.50 0 115.03** 0 118.04** f 0 21.80 0 22.00 0 21.87 0 22.72 t 0 137.44 0 131.00 0 136.39* 0 140.42** a ll m 3 361.16** 0 336.55** 0 339.56** 5 365.89** f 4 85.38* 0 80.18 0 80.13 5 86.39* t 4 445.84** 0 416.27** 0 419.14** 5 451.89** j bagh college dentistry vol. 29(1), march 2017 oral health status pedodontics, orthodontics and preventive dentistry 122 table 2: caries-experience (median and mean rank) of ds, ms, fs, and dmfs) of permanent teeth among study and control groups by age and gender. * significant, ** highly significant (higher), between study group and control group, m=median table 3: median and mean rank of plaque, gingival and calculus indices among study and control groups by age groups and gender. * significant, ** highly significant (higher), between study group and control group, m = median g r o u p a g e (y e a r ) g e n d e r ds ms fs dmfs m mean rank m mean rank m mean rank m mean rank s tu d y 6 -1 0 m 0.0 177.76 0.0 206.11 0.0 207.96 0.0 171.87 f 0.0 48.33 0.0 54.59 0.0 54.83 0.0 47.91 t 0.0 225.52 0.0 260.22 0.0 262.31 0.0 219.24 1 1 -1 5 m 2.0 87.59 0.0 105.50 0.0 103.53 2.5 86.46 f 3.5 17.60 0.0 20.73 0.0 19.63 4.0 16.80 t 2.0 104.84 0.0 125.75 0.0 122.75 3.0 103.13 a ll m 0.0 269.96 0.0 311.20 0.0 312.65 0.0 265.30 f 0.0 67.20 0.0 74.84 0.0 74.37 0.0 66.74 t 0.0 336.60 0.0 385.57 0.0 386.56 0.0 331.61 c o n tr o l 6 -1 0 m 2.0 246.23** 0.0 223.14** 0.0 221.64* 2.0 251.03** f 0.0 63.33** 0.0 58.10 0.0 57.89 2.0 63.68** t 1.5 309.15** 0.0 280.74** 0.0 279.02* 2.0 314.29** 1 1 -1 5 m 5.0 129.59 0.0 114.67 0.0 116.31 7.0 130.54 f 5.0 25.83* 0.0 23.11 0.0 24.07 8.0 26.52* t 5.0 154.79** 0.0 137.25 0.0 139.76* 7.0 156.23** a ll m 2.0 371.09** 0.0 337.24** 0.0 336.05* 3.0 374.91** f 2.0 87.13** 0.0 80.67 0.0 81.07 2.5 87.52** t 2.0 457.81** 0.0 417.39** 0.0 416.57** 3.0 461.93** group age (year) g e n d e r pli gi ci m mean rank m mean rank m mean rank s tu d y 6-10 m 1.33 263.94** 0.58 262.51** 0.00 248.02** f 1.58 72.76** 0.75 73.28** 0.08 68.37** t 1.34 336.71** 0.62 335.30** 0.04 315.97** 11-15 m 1.38 139.02** 0.75 135.28** 0.08 120.18* f 1.73 30.45** 0.83 29.58** 0.17 28.93** t 1.50 168.75** 0.75 164.63** 0.08 148.74** all m 1.33 401.81** 0.63 397.20** 0.08 367.49** f 1.63 102.79** 0.75 102.50** 0.08 96.66** t 1.40 504.66** 0.67 499.52** 0.08 463.89** c o n tr o l 6-10 m 0.71 176.05 0.33 177.22 0.00 189.02 f 0.65 42.90 0.29 42.47 0.00 46.57 t 0.71 218.11 0.33 219.26 0.00 235.09 11-15 m 0.71 86.73 0.33 89.85 0.00 102.44 f 0.73 14.65 0.36 15.41 0.00 15.98 t 0.71 101.16 0.33 104.62 0.00 117.95 all m 0.71 262.87 0.33 266.65 0.00 291.04 f 0.67 57.05 0.32 57.29 0.00 62.23 t 0.71 319.09 0.33 323.33 0.00 352.74 j bagh college dentistry vol. 29(1), march 2017 oral health status pedodontics, orthodontics and preventive dentistry 123 table 4: correlation coefficient between caries-experience (primary and permanent teeth) and plaque, gingival and calculus indices among study and control group. ** highly significant table 5: the distribution of children according to body mass index for age z-score indicator among study and control groups by age and gender groups ds dmfs ds dmfs r p r p r p r p study pii 0.551 < 0.001** 0.559 < 0.001** 0.428 < 0.001** 0.416 < 0.001** gi 0.485 < 0.001** 0.496 < 0.001** 0.444 < 0.001** 0.428 < 0.001** ci 0.448 < 0.001** 0.458 < 0.001** 0.449 < 0.001** 0.440 < 0.001** control pii 0.457 < 0.001** 0.502 < 0.001** 0.452 < 0.001** 0.440 < 0.001** gi 0.418 < 0.001** 0.455 < 0.001** 0.467 < 0.001** 0.449 < 0.001** ci 0.227 < 0.001** 0.243 < 0.001** 0.394 < 0.001** 0.388 < 0.001** g r o u p a g e g e n d e r t o ta l n o . severe wasting (<-3) wasting (-3 to -2) acceptable (>-2 to 1) possible risk of overweight (1-2) overweight (>2 to 3) obese (>3) no. % no. % no. % no. % no. % no. % s tu d y 6 -1 0 m 193 5 2.59 12 6.22 126 65.29 33 17.10 10 5.18 7 3.63 f 51 1 1.96 2 3.92 37 72.55 8 15.69 2 3.92 1 1.96 t 244 6 2.46 14 5.74 163 66.80 41 16.80 12 4.92 8 3.28 1 1 -1 5 m 100 2 2.00 4 4.00 70 70.00 16 16.00 6 6.00 2 2.00 f 20 0 0.00 1 5.00 19 95.00 0 0.00 0 0.00 0 0.00 t 120 2 1.67 5 4.17 89 74.17 16 13.33 6 5.00 2 1.67 a ll m 293 7 2.39 16 5.46 196 66.89 49 16.72 16 5.46 9 3.07 f 71 1 1.41 3 4.23 56 78.87 8 11.27 2 2.82 1 1.41 t 364 8 2.20 19 5.22 252 69.23 57 15.66 18 4.95 10 2.75 c o n tr o l 6 -1 0 m 237 10 4.22 20 8.44 162 68.35 33 13.92 8 3.38 4 1.69 f 61 1 1.64 5 8.20 47 77.05 7 11.48 1 1.64 0 0.00 t 298 11 3.69 25 8.39 209 70.13 40 13.42 9 3.02 4 1.34 1 1 -1 5 m 120 5 4.17 13 10.83 82 68.33 16 13.33 3 2.50 1 0.83 f 23 0 0.00 2 8.70 20 86.96 1 4.35 0 0.00 0 0.00 t 143 5 3.50 15 10.49 102 71.33 17 11.89 3 2.10 1 0.70 a ll m 357 15 4.20 33 9.24 244 68.35 49 13.73 11 3.08 5 1.40 f 84 1 1.19 7 8.33 67 79.76 8 9.52 1 1.19 0 0.00 t 441 16 3.63 40 9.07 311 70.52 57 12.93 12 2.72 5 1.13 j bagh college dentistry vol. 29(1), march 2017 oral health status pedodontics, orthodontics and preventive dentistry 124 table 6: median and mean rank of body mass index for age z-score among study and control groups by age groups and gender. ** highly significant (higher), between study group and control group. table 7: correlation coefficient between bmi for age z-score and caries-experience of primary and permanent teeth among study and control groups. ** highly significant table 8: correlation coefficient between bmi for age and pii, gi, ci among study and control groups. * significant, ** highly significant age (years) gender study control total no. m mean rank total no. m mean rank 6-10 m 193 0.17 224.42 237 0.02 208.24 f 51 0.14 62.17 61 -0.13 51.76 t 244 0.16 285.90 298 -0.01 259.71 11-15 m 100 0.46 125.54** 120 0.20 97.97 f 20 0.01 23.75 23 -0.13 20.48 t 120 0.41 148.41** 143 -0.04 118.23 all m 293 0.35 349.37** 357 0.03 305.91 f 71 0.03 85.13 84 -0.13 71.97 t 364 0.25 433.70** 441 -0.01 377.66 groups ds dmfs ds dmfs r p r p r p r p study -0.196 < 0.001** -0.196 < 0.001** -0.041 0.313 -0.032 0.431 control -0.204 < 0.001** -0.180 < 0.001** 0.261 < 0.001** 0.286 < 0.001** groups pli gi ci r p r p r p study -0.142 < 0.001** -0.099 0.015* -0.060 0.142 control -0.039 0.292 0.025 0.491 0.058 0.117 الخالصة صحة الفم واألسنان لألطفال الذين يعانون من .يتصف بمجموعة واسعة من األعراض، بما في ذلك صعوبة في مهارات التفاعل والتواصل االجتماعي (asd)طيف التوحد باضطرا :المقدمة أجريت هذه الدراسة لتقييم حالة صحة الفم فيما يتعلق .اضطراب التوحد مثير للجدل، بشكل عام قد يكون مستوى نظافة الفم أقل من األفراد األصحاء، ولكن لديهم معدل تسوس قابلة للمقارنة رعاية اضطراب التوحد في بغداد. المصابين بالتوحد في مراكز بالحالة الغذائية بين األطفال والمراهقين ا طفل 332 سيطرة(، في حين شملت مجموعة ال07أنثى = ،294طفل ومراهق يعانون من اضطراب التوحد )ذكر= 463معهد في بغداد، تضمنت مجموعة الدراسة 21من :والطرق المواد ة ( سن27-6الفئة العمرية. صنفت االعمار إلى فئتين عمريتين، فئة االطفال ) ( من المدارس االبتدائية والثانوية القريبة من معاهد رعاية اضطراب التوحد43، أنثى= 357ومراهق سليم )ذكر= ئية لهم باستخدام تسوس االسنان، اللويحة الجرثومية، القلح والتهاب اللثة من اجل تقييم نظافة الفم وحالة اللثة الصحية، في حين تم تقييم الحالة الغذا تم تشخيص .سنة (21-22)وفئة المراهقين .12النسخة spssتم تحليل بيانات الدراسة الحالية باستخدام برنامج (. bmiمؤشر كتلة الجسم ) ، (pliوبفارق معنوي عالي. وكان معدل الرتب لمقاييس اللويحة الجرثومية ) سيطرة( في مجموعة الدراسة اقل من مجموعة الdmfs, dmfsلمقياسي تسوس االسنان )كان معدل رتب النتائج: ,ds, dmfsوبفارق معنوي عالي بين مقاييس تسوس االسنان ) وبفارق معنوي عالي. وجود ارتباط متوسط إيجابي سيطرة( في مجموعة الدراسة اعلى من مجموعة الci( والقلح )giالتهاب اللثة ) ds and dmfsو )( مقاييس اللويحة الجرثوميةpli)( التهاب اللثة ،gi( والقلح )ci(. وقد كان معدل رتب مقياس كتلة الجسم )سيطرة( وفي المجموعتين )الدراسة والbmi for age z-score ) ة. بينما كان هناك ارتباط ضعيف عكسي وبفارق معنوي عالي بين مقياس كتلة الجسم ومقاييس تسوس االسنان في مجموعة الدراسة. سيطرفي مجموعة الدراسة اعلى من مجموعة ال قاييس تسوس االسنان ومقاييس نظافة . وجود ارتباط متوسط بين مةسيطرفي مجموعة اضطراب التوحد اقل من مجموعة ال ، نظافة الفم وصحة اللثةبينت الدراسة ان شدة تسوس االسنان: االستنتاج ة. وجود ارتباط ضعيف بين مقياس كتلة الجسم سيطرلالفم وصحة اللثة. وقد اظهرت الدراسة ان فئات امكانية زيادة الوزن، زيادة الوزن والبدانة في مجموعة اضطراب التوحد اعلى من مجموعة ا وحد.ومقاييس تسوس االسنان في مجموعة اضطراب الت j bagh college dentistry vol. 33(4), december 2021 odontogenic cysts and 83 odontogenic cysts and tumors of maxilla and maxillary sinus (a clinicopathological analysis) shahad a. waheed(1), taghreed f. zaidan(2), bashar h. abdullah(3) https://doi.org/10.26477/jbcd.v33i4.3018 abstract background: knowledge about the prevalence and distribution of pathologies in a particular location is important when a differential diagnosis is being formulated. the aim of this study was to describe the prevalence and the clinicopathological features of odontogenic cysts and tumors affecting the maxilla and to discuss the unusual presentation of those lesions within the maxillary sinus. materials and methods: a multicenter retrospective analysis was performed on pathology archives of patients who were diagnosed with maxillary odontogenic cysts and tumors from 2010 to 2020. data were collected with respect to age, gender and location. result: a total of 384 cases was identified, 320 (83.3%) cases were diagnosed as odontogenic cysts and 64 (16.6%) as odontogenic tumors. the mean age was 30.5 years with a standard deviation of 16.2 years. male patients were more commonly affected (n=220, 57.3%). radicular cyst was the most common cyst (n=205, 64.1%), while the most common tumor was odontoma (n=14, 21.9%) and dentigerous cyst was the most common lesion to present within the maxillary sinus. conclusion: this study indicates that there are some geographic similarities and differences in regard to distribution of odontogenic cysts and tumors in the maxilla and it raises awareness of their presentation within the maxillary sinus especially if there is an association with an ectopic or adjacent impacted tooth. keywords: odontogenic cysts, odontogenic tumors, maxillary sinus, maxilla. (received: 2/10/2021, accepted: 31/10/2021) introduction the microscopic features of jaw bones are similar to any other bones in the body. their uniqueness is derived from the fact that they enclose the odontogenic apparatus, a structure that gives rise to a variety of diseases: developmental, inflammatory and neoplastic.(1) odontogenic cysts are the most common jaw lesions and can be either inflammatory or developmental in origin.(2) on the other hand, odontogenic tumors (ogts) are rare, accounting for less than one percent of all oral tumors. these tumors might pose a diagnostic challenge for both clinicians and pathologists due to their rarity and overlapping histopathological features.(3) the anatomic location of the maxillary sinus within the body of maxilla makes it vulnerable to the same conditions that affect maxillary bone. odontogenic lesions of the maxillary sinus are scarce in literature limited mostly to case reports or series. (4,5,6) most studies investigated the prevalence and distribution of those lesions in both jaws, no study was found to focus entirely on the maxilla and data. (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. (3) professor, department of oral diagnosis, college of dentistry, university of baghdad. corresponding author, shahadwaheed@yahoo.com materials and methods data for this retrospective study were collected from the filing systems and pathology archives of nine histopathology laboratories in baghdad city during the period from 2010 – 2020. the inclusion criteria were histopathology reports for patients diagnosed with an odontogenic cyst or odontogenic tumor affecting the maxilla or maxillary sinus. duplicate reports and recurrences of previously diagnosed or treated lesions were excluded. in relation to the anatomic site of the lesions, two main sites were identified (maxilla and maxillary sinus). further maxillary lesions were divided into three segments based on the clinical and radiographic findings; anterior maxilla extends from right canine to left canine. posterior maxilla extends from the first premolar to maxillary tuberosity, and the palate. histological diagnoses for the lesions were classified into categories according to the most recent world health organization (who) classification of head and neck tumors 2017.(7) cysts were classified according to origin into inflammatory and developmental while odontogenic tumors into epithelial tumors, mixed epithelial and mesenchymal tumors, and mesenchymal tumors. ogts were also divided into two types; benign and malignant tumors. a histopathology examination was performed whenever there was a doubt about the diagnosis using available histologic slides stained with hematoxylin and eosin (h&e) by an oral pathologist (b.a). the raw collected data were organized and subdivided into categories using microsoft excel 2010 sheets. no https://doi.org/10.26477/jbcd.v33i4.3018 j bagh college dentistry vol. 33(4), december 2021 odontogenic cysts and 83 formal statistical tests were done; only descriptive analysis was performed using statistical package for social sciences (spss) version 23. results a total of 7384 histopathology reports of oral and maxillofacial lesions was found, 1064 (14.4) of cases were identified in the maxilla, of those 384 (36.09%) cases in the odontogenic cysts and tumors group; 320 (30.07%) odontogenic cysts and 64 (6.01%) odontogenic tumors. the mean age was 30.5 years with a sd of 16.2 years. male patients were affected more (n=220, 57.3%) than females (n=164, 42.7%). odontogenic cysts: 338 cases were identified in the cysts category; 18 (1.6%) cases were non-odontogenic cysts and 320 (29.5%) odontogenic cysts. males were affected more (n=187, 58.4%) than females. the mean age was 30.48 years. most cysts were inflammatory in origin (n=211, 65.9%), while developmental cysts represent (n=106, 33.12%) and 3 cases were not otherwise specified (0.9%). the most common diagnosis was radicular cyst (n=205) followed by dentigerous cyst and keratocyst. table 1 demonstrates the frequency and distribution of different odontogenic cysts according to gender and age. table 1: the frequency and distribution of odontogenic cysts according to gender and age. diagnosis frequency gender age (years) n % m f m:f mean sd min max radicular cyst 205 64.1 113 92 1.2 32.3 14.65 8 80 dentigerous cyst 49 15.3 38 11 3.45 23 17.54 6 61 keratocyst 45 14.1 26 19 1.36 29.08 15.48 10 85 calcifying odontogenic cyst 8 2.5 4 4 1 39.37 23.07 9 64 residual cyst 6 1.9 2 4 0.5 43.66 15.27 27 65 odontogenic cyst not otherwise specified 3 0.9 1 2 0.5 24.66 5.507 19 30 eruption cyst 1 0.3 1 0 3 . 3 3 gingival cyst of newborn 1 0.3 0 1 1 week . 1 week 1 wee k lateral periodontal cyst 1 0.3 1 0 19 . 19 19 orthokeratinized cyst 1 0.3 1 0 15 . 15 15 total 320 100 187 133 1.4 30.48 15.97 1 week 85 odontogenic tumors: males were affected slightly more (n= 33, 51.6%) than females. the mean age was 31 years. most tumors were of epithelial origin (n=25, 39.1%) while mesenchymal origin represent (n=23, 35.9%) and mixed origin was (n=16, 25%). almost, all were benign tumors (n=62, 96.9%) except for two malignant cases (n=2, 3.1%). the most common diagnosis was odontoma (n=14) followed by both ameloblastoma and odontogenic myxoma (n=12, 18.8%), as shown in (table 2). site: the precise site was reported in 196 cases with most lesions affecting the anterior maxilla (n=122, 62.2%), while posterior maxilla was (n=38, 19.38%), palate (n=16, 8.16%). few cases were reported in maxillary sinus (n=20, 10.2%) (n=8 dentigerous cysts, n=6 radicular cysts, n=2 keratocyst, n=1 orthokeratinized cyst, n=1 adenomatoid odontogenic tumor, and n=2 myxoma). j bagh college dentistry vol. 33(4), december 2021 odontogenic cysts and 04 table 2: the frequency and distribution of odontogenic tumors according to gender and age diagnosis frequency gender age (years) n % m f m:f mean sd min max odontoma 14 21.9 5 9 0.55 19.4 11.58 8 45 ameloblastoma 12 18.8 10 2 5 51.83 17.19 30 85 myxoma 12 18.8 5 7 0.7 28.25 11.09 15 45 odontogenic fibroma 10 15.6 5 5 1 34.5 13.8 14 54 pindborg tumor 5 7.8 2 3 0.66 24.2 11.4 13 43 adenomatoid odontogenic tumor 4 6.3 2 2 1 19.25 5.67 13 25 unicystic ameloblastoma 2 3.1 0 2 21.5 4.9 18 25 ameloblastic fibroma 1 1.6 0 1 12 . 12 12 cementoblastoma 1 1.6 1 0 25 . 25 25 ghost cell carcinoma 1 1.6 1 0 48 . 48 48 malignant ameloblastoma 1 1.6 1 0 74 . 74 74 primordial odontogenic tumor 1 1.6 1 0 14 . 14 14 total 64 100 33 31 1.06 31.1 17.7 8 85 discussion many previous studies analyzed those lesions in both jaws; however, no study focus entirely on the maxilla; because of that to facilitate comparison, some of these studies were reviewed and information regarding maxillary odontogenic lesions was extracted and displayed in (table 3) and (table 4) in regard to odontogenic cysts, most of the cysts were of inflammatory origin and radicular cyst was the most common diagnosis which is in accordance with all previous studies in (table 3).(8, 9,10,11,12) the second most common odontogenic cyst was dentigerous cyst (15.3%) which is similar to other studies.(8, 9,10,12). but it disagrees with del corso et al.(11) these cysts are developed in association with unerupted teeth mostly maxillary canine and third molars with predilection for patients in the second decade of life.(9) odontogenic keratocyst was the third most common cyst in the maxilla which is similar with izgi et al., and kambalimath et al studies.(8,10) this study followed the 2017 who classification that reclassified keratocyst from benign tumor to a cyst; in contrast to some previous published studies that followed the old classification.(9,14) this study showed a close prevalence between dentigerous cyst and keratocyst (15.3%, 14.1%) respectively. this could be explained by the fact that most dentigerous cysts are small, symptomless, discovered accidently on radiographs and clinicians may not request a histopathology examination relying only on clinical diagnosis. keratocyst usually grow to larger sizes, produce more obvious clinical symptoms and require further surgical intervention. regardless the size or appearance, any cystic lesions of the jaw should raise the suspicion of more aggressive odontogenic lesion such as keratocyst, ameloblastoma, pindborg tumor especially due to the fact that many of them can be associated with impacted teeth and resemble the radiographic appearance of dentigerous cyst.(13) j bagh college dentistry vol. 33(4), december 2021 odontogenic cysts and 04 table 3: the characteristics of maxillary odontogenic cysts in comparison studies study (author, year) country number of cases in the maxilla the most common cysts (n) time period (years) (izgi et al., 2021).(8) turkey 165 radicular cyst (95) dentigerous cyst (22) keratocyst (13) (2008 – 2018) (villasis-sarmiento et al., 2017).(9) mexico 337 radicular cyst (215) dentigerous cyst (110) residual cyst (5) (2000 – 2013) (kambalimath et al., 2014).(10) india 76 radicular cyst (57) dentigerous cyst (7) keratocyst (3) (2001 – 2011) (del corso et al., 2014).(11) italia 374 radicular cyst (205) keratocyst (48) dentigerous cyst (21) (1992 – 2012) (bataineh et al., 2004).(12) jordan 313 radicular cyst (149) dentigerous cyst (67) residual cyst (59) lpc (34) (1989 – 2001) with regard to odontogenic tumors, almost all tumors were benign with only two malignant cases such finding is in accordance with all studies in (table 2).(14,15,16,17) most tumors were of epithelial origin which is similar with nalabolu et al.(14) the most common tumor in this study was odontoma that is similar to previous studies.(15,16,17) odontoma represents a hamartous lesion rather than a true neoplasm and is believed to be the most common odontogenic tumor like lesion; however, it is usually asymptomatic and diagnosed accidentally on radiograph. this could be the reason for the small number of cases in this study since patients do not seek treatment until obvious symptoms appear.(14) geographic, genetic and environmental factors can also affect the prevalence of odontomes.(14) similar to other studies, this lesion showed a high prevalence in the second decade of life.(14,16) ameloblastoma was the second most common tumor which was in agreement with taghavi et al.(17) and with other studies. (15,16) if keratocyst was excluded, a male predilection was shown with male to female ratio of 5:1 which disagrees with zwahlen and grätz literature review,(18) that reported no gender predilection. although maxillary ameloblastomas are rare compared to those of the mandible; they still ranked high among ogts in this study. this tumor is aggressive, usually showing extensive extension into the adjacent structures such as nasal cavity and maxillary sinus,(19) and can clinically mimic a sinonasal malignancy. ameloblastoma can arise primary from the surface epithelium of the maxillary sinus; however, such a diagnosis is rare and can’t be made without excluding an extension from the surrounding maxillary bone first.(20) odontogenic myxoma is a benign mesenchymal tumor. it is reported as the third most common odontogenic neoplasm of jaw after odontoma and ameloblastoma.(17) in this study, it showed a similar prevalence to ameloblastoma (18.8%) and two cases were reported initially as sinus lesions. this lesion usually arises within the maxillary bone and invades the adjacent sinus; however sinonasal counterparts have been rarely reported in the literature.(21) there are different theories regarding the etiology of this lesion in sinus. myxomas may arise from modified fibroblasts associated with tooth germ in which these altered cells can hyper secrete mucin.(22) the association between myxoma and impacted teeth has provided support for this theory. however, evidence exists that argues against this odontogenic theory a study by slootweg and wittkampf.(23) demonstrated that the extracellular matrix of myxomas differs histologically from the extracellular matrix of dental and periodontal tissues. also, the presence of reported cases of myxomas in remote sites from odontogenic tissues such as sphenoid sinus.(24) this study also reported other rare lesions in less numbers such as calcifying odontogenic cyst (2.5%), pindborg tumor (7.8%), unicystic ameloblastoma (3.1%), ameloblastic fibroma (1.6%), cementoblastoma (1.6%) and one case of the newly described entity primordial odontogenic tumor that j bagh college dentistry vol. 33(4), december 2021 odontogenic cysts and 04 was published previously by the author (b.a.) as the first iraqi case report.(25) the anterior maxilla was more commonly affected in both cysts and tumors; a finding that is similar with izgi et al.(8) table 4: the characteristics of maxillary odontogenic tumors in comparison studies study (author, year) country number of cases in the maxilla the most common tumors (n) time period (years) (nalabolu et al., 2017).(14) india 45 keratocyst (17) ameloblastoma (16) odontoma (6) adenomatoid odontogenic tumor (6) (2002 – 2014) (alsheddi et al., 2015).(15) saudi arabia 52 odontoma (15) keratocyst (14) ameloblastoma (6) (1984 – 2010) (avelar et al., 2008).(16) brazil 78 odontoma (31) keratocyst (17) ameloblastoma (9) myxoma (8) (1992 – 2007) (taghavi et al., 2013).(17) iran 50 odontoma (16) ameloblastoma (13) myxoma (11) (2000 – 2010) maxillary sinus is vulnerable to diseases of odontogenic origin due to its proximity with developing teeth and root apices. diagnosis of such lesions in this location is challenging as routine radiographs do not offer characteristic features and show overlaps of various adjacent structures.(26) most odontogenic cysts and tumors in this location are associated with an ectopic tooth inside the sinus with the commonest being dentigerous cyst.(27,28) which is similar to this study findings. many theories exist regard the etiology of those ectopic teeth including trauma, developmental and pathologic conditions. the most likely scenario is the presence of impacted tooth (mostly canine or molars) in close anatomic relation to the sinus wall and as the cyst grows and enlarges it displacing the tooth inside the sinus space.(4) other odontogenic cysts had also been reported infrequently to involve the maxillary sinus. radicular cyst can grow to large sizes, breach the sinus wall and occupy the entire sinus space.(6) keratocysts can also involve the maxillary sinus with a controversy regarding its origin; it might arise from the entrapment of dental lamina within the sinus during normal development due to the close anatomic relation,(29) or from normal expansion of an adjacent intraosseous cyst, or in relation to an ectopic tooth inside the sinus.(5) conclusion there are some geographic similarities and differences with regard to the prevalence and distribution of odontogenic cysts and tumors of maxilla. the presence of these lesions within the maxillary sinus is uncommon and different theories exist in the literature regarding their origin; nevertheless, they should be included in the differential diagnosis of sinus lesions especially if there was an association with an ectopic or adjacent impacted tooth. conflict of interest: none. references 1. jonathan b, mandible and maxilla, in: goldblum jr, lamps lw, mckenney jk, myers jl, rosai and ackerman's surgical pathology, elsevier health sciences, philadelphia, 2017: 212-234. 2. jones av, craig gt, franklin cd. range and demographics of odontogenic cysts diagnosed in a uk population over a 30‐ year period. j oral pathol med. 2006;35:500-7. 3. neville bw, damm dd, allen cm, et al. oral and maxillofacial pathology, fourth ed., elsevier health sciences, philadelphia, 2015. 4. buyukkurt mc, omezli mm, miloglu o. dentigerous cyst associated with an ectopic tooth in the maxillary sinus: a report of 3 cases and review of the literature. oral surg oral med oral pathol oral radiol endod. 2010;109:67-71. 5. sheethal hs, rao k, umadevi hs, et al. odontogenic keratocyst arising in the maxillary sinus: a rare case report. j oral maxillofac pathol. 2019; 23:74. 6. kumar n, dadhich a. unusually large radicular cyst presenting in the maxillary sinus. bmj case rep. 2020; 13. j bagh college dentistry vol. 33(4), december 2021 odontogenic cysts and 08 7. el-naggar ak, chan jk, grandis jr, et al, who classification of head and neck tumours. international agency for research on cancer (iarc), france, 2017. 8. izgi e, mollaoglu n, simsek mb. prevalence of odontogenic cysts and tumors on turkish sample according to latest classification of world health organization: a 10-year retrospective study. niger j clin pract. 2021;24:355. 9. villasis-sarmiento l, portilla-robertson j, melendez-ocampo a, et al. prevalence and distribution of odontogenic cysts in a mexican sample. a 753 cases study. j clin exp dent. 2017; 9:e531. 10. kambalimath dh, kambalimath hv, agrawal sm, et al. prevalence and distribution of odontogenic cyst in indian population: a 10 year retrospective study. j clin exp dent. 2014;13:10-5 11. del corso g, righi a, bombardi m, et al. jaw cysts diagnosed in an italian population over a 20-year period. int j surg pathol. 2014;22:699-706. 12. bataineh ab, ma'amon ar, qudah ma. the prevalence of inflammatory and developmental odontogenic cysts in a jordanian population: a clinicopathologic study. quintessence int. 2004;35:815-9. 13. müller s. developmental odontogenic lesions associated with the crown of an impacted tooth: a guide to the distinct histologic features required for classification. head neck pathol. 2021;15:10712. 14. nalabolu gr, mohiddin a, hiremath sk, et al. epidemiological study of odontogenic tumours: an institutional experience. j infect public health. 2017;10:324-30. 15. alsheddi ma, alsenani ma, aldosari aw. odontogenic tumors: analysis of 188 cases from saudi arabia. ann saudi med. 2015;35:146-50. 16. avelar rl, antunes aa, santos td, et al. odontogenic tumors: clinical and pathology study of 238 cases. braz j otorhinolaryngol. 2008;74:668-73. 17. taghavi n, rajabi m, mehrdad l, et al. 0-year retrospective study on odontogenic tumors in iran. indian j dent res. 2013;24:220. 18. zwahlen ra, grätz kw. maxillary ameloblastomas: a review of the literature and of a 15-year database. j craniomaxillofac surg. 2002;30:273-9. 19. evangelou z, zarachi a, dumollard jm, et al. maxillary ameloblastoma: a review with clinical, histological and prognostic data of a rare tumor. in vivo. 2020;34:2249-58. 20. schafer dr, thompson ld, smith bc, et al. primary ameloblastoma of the sinonasal tract: a clinicopathologic study of 24 cases. cancer. 1998;82:667-74. 21. mewar p, gonzález-torres ke, jacks tm, et al. sinonasal myxoma: a distinct lesion of infants. head neck pathol. 2020;14:212-9. 22. white dk, chen sy, mohnac am, et al. odontogenic myxoma: a clinical and ultrastructural study. oral surg oral med oral pathol. 1975;39:90117. 23. slootweg pj, wittkampf ar. myxoma of the jaws: an analysis of 15 cases. j maxillofac surg. 1986;14:46-52. 24. moore ba, wine t, burkey bb, et al. sphenoid sinus myxoma: case report and literature review. ochsner j. 2008;8:166-71. 25. bashar a, venus m, omar m, et al. primordial odontogenic tumor: a case report with a novel clinical presentation. j oral maxillofac surg med pathol. 2021;33:239-42. 26. mehra p, jeong d. maxillary sinusitis of odontogenic origin. curr allergy asthma rep. 2009;9:238-43. 27. pierse je, stern a. benign cysts and tumors of the paranasal sinuses. oral maxillofac surg clin north am. 2012;24:249-64. 28. press sg. odontogenic tumors of the maxillary sinus. curr opin otolaryngol head neck surg. 2008;16:47-54. 29. cioffi ga, terezhalmy gt, del balso am. odontogenic keratocyst of the maxillary sinus. oral surg oral med oral pathol. 1987;64:648-51. المستخلص: الخلفية: المعرفة حول انتشار وتوزيع األمراض في موقع معين أمر مهم عند صياغة التشخيص التفريقي. كان الهدف من هذه الدراسة هو وصف األنفية غير المعتاد لتلك اآلفات داخل الجيوب ظهورالسنية التي تصيب الفك العلوي ومناقشة الاالنتشار والسمات اإلكلينيكية لألكياس واألورام للمرضى الذين تم تشخيصهم باألكياس واألورام التشخيص النسيجي تقاريرمتعدد المراكز على رجعيالمواد والطرق: تم إجراء تحليل .الفكية .. تم جمع البيانات فيما يتعلق بالعمر والجنس والموقع0202إلى عام 0202السنية في الفك العلوي من عام انحراف معياري سنة مع 42.3العمر ( أورام سنية. كان متوسط ٪04.4) 43( حالة كيسات سنية و ٪84.4) 402 حالة، 483النتيجة: تم تحديد هو الكيس األكثر شيوًعا radicular cyst كيس الجذري(. كان ال٪4..3، 002) كانوا اكثر عرضة لالصابة سنة. المرضى الذكور 04.0 ( وكان كيس األسنان ٪00.2، 03)العدد = odontoma ( ، بينما كان الورم األكثر شيوًعا هو الورم السني٪43.0، 023)العدد = dentigerous cystهو اآلفة األكثر شيوًعا الموجودة داخل الجيب الفكي. الفك العلوي واألورام السنية في كياسالدراسة إلى أن هناك بعض أوجه التشابه واالختالف الجغرافي فيما يتعلق بتوزيع اال: تشير هذه االستنتاج .مطمور وزيادة الوعي بمظهرها داخل الجيوب األنفية الفكية خاصةً إذا كان هناك ارتباط مع سن مجاور articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. dropbox 12 saif 63-68.pdf simplify your life dropbox 15 rabab 82-85.pdf simplify your life 15sahar f.docx j bagh college dentistry vol. 28(3), september 2016 the usefulness of oral diagnosis 92 the usefulness of mandibular ramus as an indicator in sex differentiation using 3d reconstructed computed tomography sahar sh. kadhim, b.d.s. (1) ahlam ahmed fatah, b.d.s., m.sc. (2) abstract background: determination of sex from an unknown human bone is an important role in forensic and anthropology field. the mandible is the largest and hardest facial bone, that commonly resist postmortem damage and forms an important source of information about sexual dimorphism. mandibular ramus can be used to differentiate between sexes and it also expresses strong univariate sexual dimorphism. this study was undertaken to assess the usefulness of mandibular ramus as an aid in sex differentiation using ct scanning among iraqi population. materials and methods: 3d reconstructed computed tomography scanning of 140 iraqi arab subjects, (7 0 males and 70 females) were analyzed with their age range from 20-60 years old. the linear measurements were located and marked on axial and sagittal sections including right and left sides of the mandible. results: for the all measurements for sexes the mean value for male were highly significant than female with (p= value < 0.001).a receiver operating characteristic curves was obtained for each variable to observe their overall performance in sex determination. the area of maximum mandibular ramus height was found to be the best parameter according to roc analysis to establish the diagnosis of male (roc=0.952cm for both unilateral and bilateral measurements). age showed no statistical difference in the current study. conclusion: 3d reconstructed computed tomography scanning plays an important role as a diagnostic method for analyzing the linear measurements of the mandibular ramus in sex differentiation. sex determination for isolated part of the skull (e.g. mandible) could be achieved, instead of complete skull, and the highest accuracy in sex determination can be obtained whether complete or part of mandible is available for examination. key words: sex determination, 3d reconstructed computed tomography, mandibular ramus, and sexual dimorphism. (j bagh coll dentistry 2016; 28(3):92-98). introduction the identification of skeletal remains is of paramount importance in medico-legal investigations. the highest accuracy in sex determination is achieved if all bones composing the skeleton are present .however, in explosion, warfare and other mass disasters like aircraft crashes, identification and sex determination are not very easy as the soft tissues are commonly no longer present, due to trauma and decomposition. in those cases, forensic anthropology serves an important role in human identification (1, 2). skull is the most dimorphic and easily sexed portion of skeleton after pelvis, as it provides valuable information about individual human characteristics, its use in personal identification of human remains providing accuracy up to 92%.but in cases where intact skull is not found, mandible may play a vital role in sex determination as it is the most dimorphic, largest, and strongest bone of skull. presence of a dense layer of compact bone makes it very durable and well preserved than many other bones, its morphological features show changes with reference to age, sex, race, and forms an important source of information about sexual dimorphism (3,4). (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. radiology is a noninvasive method used to investigate the human body and as such, plays a significant role in medicolegal investigations and in the identification of human remains .the bony details such as form, size, shape, and individual characteristics are evident and consistent as shown by radiological means. thus, the comparison of earlier with later radiological records is significantly important for forensic medicine and anthropology (5). computed tomography (ct) has been increasingly used to assist in medico-legal investigations. the potential value of ct in estimation of age or visualizing features likely to enable personal identification is reported (4,6). ct allows for 3d reconstruction of the skull and enables the evaluation of the individual morphological characteristics. ct is quick and extremely precise, and thus well suited as a supplement method in medicolegal investigations, it allows investigation of anatomic structures, and accurate analysis of bony structures. the possibility of being able to reconstruct a variety of images to permit multiple and recurrent analysis long after the event occurred is a further advantage of this applied method(7-9). j bagj bagh college dentistry oral diagnosis materials and methods prospective study of ct scans for (140) iraqi adult patients, with equal number of each gender (70males and 70 females), age ranged from 59) yrs were analyzed. the sample collected from patient attending ct clinic in al hospital for differ november 2014 to march 2015 the total study sample was divided into the following groups according to different ranges of age selected table 1: distribution of participating patients according to age and groups total pathological, fractured, developmental disturbance of the mandible e.g. ( micrognathia, macrognathia, hypertrophy) (craniofacial disorders, edentulous mandibles were also excluded. the examination was performed on multi slice spiral tomography scanner (the siemens soma tom definition as). the patients were prepared for the exposure by asking them to remove any spectacles, jewelry, ear rings, and hearing aids. the patient positioned on the ct examination table tomography scan of mandibular ramus is performed in sagittal and axial sections. the following measurements will be taken maximum mandibular ramus breadth (max mrb) it is the distance between the most anterior pointon the mandibular ramus and the most posterior point on the condyle mandibular ramus breadth (min mrb) it is the smallest anterior condylar height (maximum mandibular ramus height) (max mrh) it is the height of the mandible from the most superior point on the mandibular condyle to the tubercle or most protruding portion of the inferior border of the ramus. projective height of ramus (projective hr) it is the projective height of ramus between the highest point of the mandibular condyle and lower margin of the mandible, coronoid height (ch) itis the projective distance between coronion craniometrical point at the tip of the coronoid process of the mandible mandible h college dentistry oral diagnosis materials and methods prospective study of ct scans for (140) iraqi adult patients, with equal number of each gender (70males and 70 females), age ranged from 59) yrs were analyzed. the sample collected from patient attending ct clinic in al hospital for different diagnostic purposes november 2014 to march 2015 the total study sample was divided into the following groups according to different ranges of age selected, as shown in table 1. table 1: distribution of participating patients according to age and age range groups 201 302 403 504 total pathological, fractured, developmental disturbance of the mandible e.g. ( micrognathia, macrognathia, hypertrophy), deformed mandibles e.g. craniofacial disorders, edentulous mandibles were also excluded. the examination was performed on multi slice spiral tomography scanner (the siemens soma tom definition as). the patients were prepared for the exposure by asking them to remove any spectacles, jewelry, ear rings, and hearing aids. the patient positioned on the ct examination table tomography scan of mandibular ramus is performed in sagittal and axial sections. the following measurements will be taken maximum mandibular ramus breadth (max mrb) it is the distance between the most anterior pointon the mandibular ramus and the most posterior point on the condyle mandibular ramus breadth (min mrb) it is the smallest anterior–posterior diameter of the ramus, condylar height (maximum mandibular ramus height) (max mrh) it is the height of the mandible from the most superior point on the mandibular condyle to the tubercle or most protruding portion of the inferior border of the projective height of ramus (projective hr) it is the projective height of ramus between the highest point of the mandibular condyle and lower margin of the mandible, coronoid height (ch) itis the projective distance between coronion craniometrical point at the tip of the coronoid process of the mandible mandible, as shown in figures 1,2,3,4,5. h college dentistry materials and methods prospective study of ct scans for (140) iraqi adult patients, with equal number of each gender (70males and 70 females), age ranged from 59) yrs were analyzed. the sample collected from patient attending ct clinic in al ent diagnostic purposes november 2014 to march 2015. the total study sample was divided into the following groups according to different ranges of as shown in table 1. table 1: distribution of participating patients according to age and male age range 25 -29 17 -39 19 -49 9 -59 70 pathological, fractured, developmental disturbance of the mandible e.g. ( micrognathia, macrognathia, and facial deformed mandibles e.g. craniofacial disorders, trauma, edentulous mandibles were also excluded. the examination was performed on multi slice spiral tomography scanner (the siemens soma tom definition as). the patients were prepared for the exposure by asking them to remove any spectacles, jewelry, ear rings, and hearing aids. the patient positioned on the ct examination table tomography scan of mandibular ramus is performed in sagittal and axial sections. the following measurements will be taken maximum mandibular ramus breadth (max mrb) it is the distance between the most anterior pointon the mandibular ramus and the most posterior point on the condyle mandibular ramus breadth (min mrb) it is the posterior diameter of the ramus, condylar height (maximum mandibular ramus height) (max mrh) it is the height of the mandible from the most superior point on the mandibular condyle to the tubercle or most protruding portion of the inferior border of the projective height of ramus (projective hr) it is the projective height of ramus between the highest point of the mandibular condyle and lower margin of the mandible, coronoid height (ch) itis the projective distance between coronion craniometrical point at the tip of the coronoid process of the mandible)and lower margin of the hown in figures 1,2,3,4,5. h college dentistry vol. 2 materials and methods prospective study of ct scans for (140) iraqi adult patients, with equal number of each gender (70males and 70 females), age ranged from (20 59) yrs were analyzed. the sample collected from patient attending ct clinic in al-neuroscience ent diagnostic purposes from the total study sample was divided into the following groups according to different ranges of table 1: distribution of participating patients according to age and gender female male 21 19 20 10 70 pathological, fractured, developmental disturbance of the mandible e.g. (agnathia, and facial hemi deformed mandibles e.g. , etc……) and edentulous mandibles were also excluded. the examination was performed on multi slice spiral tomography scanner (the siemens the patients were prepared for the exposure by asking them to remove any spectacles, jewelry, ear rings, and hearing aids. the patient positioned on the ct examination table. computed tomography scan of mandibular ramus is performed in sagittal and axial sections. the following measurements will be taken(10,11): maximum mandibular ramus breadth (max mrb) it is the distance between the most anterior pointon the mandibular ramus and the most posterior point on the condyle, minimum mandibular ramus breadth (min mrb) it is the posterior diameter of the ramus, condylar height (maximum mandibular ramus height) (max mrh) it is the height of the ramus of the mandible from the most superior point on the mandibular condyle to the tubercle or most protruding portion of the inferior border of the projective height of ramus (projective hr) it is the projective height of ramus between the highest point of the mandibular condyle and lower margin of the mandible, coronoid height (ch) itis the projective distance between coronion( craniometrical point at the tip of the coronoid and lower margin of the hown in figures 1,2,3,4,5. vol. 28(3), september 93 prospective study of ct scans for (140) iraqi adult patients, with equal number of each gender (2059) yrs were analyzed. the sample collected from neuroscience from the total study sample was divided into the following groups according to different ranges of pathological, fractured, developmental agnathia, hemi deformed mandibles e.g. ) and the examination was performed on multislice spiral tomography scanner (the siemens the patients were prepared for the exposure by asking them to remove any spectacles, jewelry, ear rings, and hearing aids. the patient positioned computed tomography scan of mandibular ramus is performed in sagittal and axial sections. the maximum mandibular ramus breadth (max mrb) it is the distance between the most anterior pointon the mandibular ramus and the most minimum mandibular ramus breadth (min mrb) it is the posterior diameter of the ramus, condylar height (maximum mandibular ramus of the ramus of the mandible from the most superior point on the mandibular condyle to the tubercle or most protruding portion of the inferior border of the projective height of ramus (projective hr) it is the projective height of ramus between the highest point of the mandibular condyle and lower margin of the mandible, coronoid height (ch) itis the craniometrical point at the tip of the coronoid and lower margin of the distance between two gonia (the angle formed by the junction of the posterior and lower borders of human lower jaw, bicondylar breadth (bicondylar b) it is the straight distance be lateral points on the two condyles,mandibular length (ml) it is the distance of anterior margin of the chin from a center point on a projected straight line placed along the posterior border of two gonia as follow: mandibular index = bicondylar breadth figure figure2: september 2016 bigonial breadth (bigonial b) it is the straight distance between two gonia (the angle formed by the junction of the posterior and lower borders of human lower jaw, bicondylar breadth (bicondylar b) it is the straight distance be lateral points on the two condyles,mandibular length (ml) it is the distance of anterior margin of the chin from a center point on a projected straight line placed along the posterior border of two gonia, mandibular index (mi): was calculate as follow: mandibular index = bicondylar breadth figure 1:linear measurements of condylar height (max computed tomography figure2:linear measurements of condylar height (min mrb) by 3d reconstructed computed tomography image in sagittal 2016 bigonial breadth (bigonial b) it is the straight distance between two gonia (the angle formed by the junction of the posterior and lower borders of human lower jaw, bicondylar breadth (bicondylar b) it is the straight distance be lateral points on the two condyles,mandibular length (ml) it is the distance of anterior margin of the chin from a center point on a projected straight line placed along the posterior border of mandibular index (mi): was calculate mandibular index = mandibular length x 100 bicondylar breadth linear measurements of condylar ax mrb) by 3d reconstructed computed tomography section linear measurements of condylar (min mrb) by 3d reconstructed computed tomography image in sagittal section the usefulness of bigonial breadth (bigonial b) it is the straight distance between two gonia (the angle formed by the junction of the posterior and lower borders of human lower jaw, bicondylar breadth (bicondylar b) it is the straight distance between the most lateral points on the two condyles,mandibular length (ml) it is the distance of anterior margin of the chin from a center point on a projected straight line placed along the posterior border of mandibular index (mi): was calculate mandibular length x 100 linear measurements of condylar ) by 3d reconstructed computed tomography image in sagittal section linear measurements of condylar (min mrb) by 3d reconstructed computed tomography image in sagittal section. the usefulness of bigonial breadth (bigonial b) it is the straight distance between two gonia (the angle formed by the junction of the posterior and lower borders of human lower jaw, bicondylar breadth (bicondylar tween the most lateral points on the two condyles,mandibular length (ml) it is the distance of anterior margin of the chin from a center point on a projected straight line placed along the posterior border of mandibular index (mi): was calculated mandibular length x 100 linear measurements of condylar ) by 3d reconstructed image in sagittal linear measurements of condylar (min mrb) by 3d reconstructed computed tomography image in sagittal the usefulness of j bagj bagh college dentistry oral diagnosis figure3: height (m computed tomography image in sagittal figure4 height of ramus (projective hr) reconstructed computed tomography image figure 5: linear measurements of coronoid hight of ramus(ch) by 3d reconstructed computed h college dentistry oral diagnosis figure3:linear measurements of condylar height (max mrh) by 3d reconstructed computed tomography image in sagittal section 4: linear measurements of height of ramus (projective hr) reconstructed computed tomography image in sagittal section. figure 5: linear measurements of coronoid hight of ramus(ch) by 3d reconstructed computed tomography image in sagittal section. h college dentistry linear measurements of condylar mrh) by 3d reconstructed computed tomography image in sagittal section. linear measurements of height of ramus (projective hr) reconstructed computed tomography image in sagittal section. figure 5: linear measurements of coronoid hight of ramus(ch) by 3d reconstructed tomography image in sagittal section. h college dentistry vol. 2 linear measurements of condylar mrh) by 3d reconstructed computed tomography image in sagittal linear measurements of projective height of ramus (projective hr) by 3d reconstructed computed tomography image in sagittal section. figure 5: linear measurements of coronoid hight of ramus(ch) by 3d reconstructed tomography image in sagittal vol. 28(3), september 94 linear measurements of condylar mrh) by 3d reconstructed computed tomography image in sagittal projective by 3d reconstructed computed tomography image figure 5: linear measurements of coronoid hight of ramus(ch) by 3d reconstructed tomography image in sagittal statistical statistical advice was sought for. statistical analysis was done using spss version 21 computer software social sciences). (mandibular calculated) showed no statistically significant departure from normality. they were conveniently described by mean, sd (standard deviation) and se (standard error), and the parametric statistical tests of significance were used. significance of difference between left sides. the magnitude of difference between right and left side was estimated by cohen's d. results measurements, the firs with the suggestion of presence of (hemi mandible) that is why the linear measurements were made for one side of the mandible (either right or left side) separately, such measurements based on the fact there was no statistically sig the left side of the ramus called measurements". suggestion of presence of (intact complete mandible); this par linear mandibular ramus measurements". the gender difference in the mean of unilateral and bilateral measurements anatomical landmarks in both male and either unilateral or bilateral measurements, demonstrated a highly differences the highest difference in mean between males and females was for the area of (max mrh) which was (12.1 mm). highest difference in mean was for ( b) which tested linear measurements was strong effect when evaluated by cohen's d for the effect size for all tested parameters september 2016 statistical analyses data analysis was computer aided. an expert statistical advice was sought for. statistical analysis was done using spss version 21 computer software social sciences). the outcome quantitative variables (mandibular calculated) showed no statistically significant departure from normality. they were conveniently described by mean, sd (standard deviation) and se (standard error), and the parametric statistical tests of significance were used. paired t-test was used to test the statistical significance of difference between left sides. the magnitude of difference between right and left side was estimated by cohen's d. results results demonstrated on two categories of measurements, the firs with the suggestion of presence of (hemi mandible) that is why the linear measurements were made for one side of the mandible (either right or left side) separately, such measurements based on the fact there was no statistically significant difference between the right side and the left side of the ramus called "unilateral linear mandibular ramus measurements". the second category was designed with suggestion of presence of (intact complete mandible); this par linear mandibular ramus measurements". the gender difference in the mean of unilateral and bilateral measurements all the selected linear measurements of the anatomical landmarks in both male and either unilateral or bilateral measurements, demonstrated a highly differences between male and female, (p<0.001), the highest difference in mean between males and females was for the area of (max mrh) which was (12.1 mm). while for highest difference in mean was for ( ) which was (13mm) tested linear measurements was strong effect when evaluated by cohen's d for the effect size for all tested parameters 2016 analyses data analysis was computer aided. an expert statistical advice was sought for. statistical analysis was done using spss version 21 computer software (statistical package for social sciences). the outcome quantitative variables (mandibular measurements and indices calculated) showed no statistically significant departure from normality. they were conveniently described by mean, sd (standard deviation) and se (standard error), and the parametric statistical tests of significance were test was used to test the statistical significance of difference between left sides. the magnitude of difference between right and left side was estimated by cohen's d. demonstrated on two categories of measurements, the first category was designed with the suggestion of presence of (hemi mandible) that is why the linear measurements were made for one side of the mandible (either right or left side) separately, such measurements based on the fact there was no statistically nificant difference between the right side and the left side of the ramus, "unilateral linear mandibular ramus measurements". the second category was designed with suggestion of presence of (intact complete mandible); this part in result is called linear mandibular ramus measurements". the gender difference in the mean of unilateral and bilateral linear mandibular ramus measurements: all the selected linear measurements of the anatomical landmarks in both male and either unilateral or bilateral measurements, demonstrated a highly statistical significant between male and female, (p<0.001), the highest difference in mean between males and females was for the area of (max mrh) which was (12.1 mm). for transverse highest difference in mean was for ( was (13mm).the gender effect on these tested linear measurements was strong effect when evaluated by cohen's d for the effect size for all tested parameters, tabl the usefulness of data analysis was computer aided. an expert statistical advice was sought for. statistical analysis was done using spss version 21 (statistical package for the outcome quantitative variables measurements and indices calculated) showed no statistically significant departure from normality. they were conveniently described by mean, sd (standard deviation) and se (standard error), and the parametric statistical tests of significance were test was used to test the statistical significance of difference between left sides. the magnitude of difference between right and left side was estimated by cohen's d. demonstrated on two categories of t category was designed with the suggestion of presence of (hemi mandible) that is why the linear measurements were made for one side of the mandible (either right or left side) separately, such measurements based on the fact there was no statistically nificant difference between the right side and this part in result is "unilateral linear mandibular ramus the second category was designed with suggestion of presence of (intact complete t in result is called "bilateral linear mandibular ramus measurements". the gender difference in the mean of unilateral linear mandibular ramus all the selected linear measurements of the anatomical landmarks in both male and either unilateral or bilateral measurements, statistical significant between male and female, (p<0.001), the highest difference in mean between males and females was for the area of (max mrh) measurements the highest difference in mean was for (bicondylar the gender effect on these tested linear measurements was strong effect when evaluated by cohen's d for the effect size , tables (2,3). the usefulness of data analysis was computer aided. an expert statistical advice was sought for. statistical analysis was done using spss version 21 (statistical package for the outcome quantitative variables measurements and indices calculated) showed no statistically significant departure from normality. they were conveniently described by mean, sd (standard deviation) and se (standard error), and the parametric statistical tests of significance were test was used to test the statistical significance of difference between left-right sides. the magnitude of difference between right and left side was estimated by cohen's d. demonstrated on two categories of t category was designed with the suggestion of presence of (hemi mandible) that is why the linear measurements were made for one side of the mandible (either right or left side) separately, such measurements based on the fact there was no statistically nificant difference between the right side and this part in result is "unilateral linear mandibular ramus the second category was designed with suggestion of presence of (intact complete "bilateral linear mandibular ramus measurements". the gender difference in the mean of unilateral linear mandibular ramus all the selected linear measurements of the anatomical landmarks in both male and female either unilateral or bilateral measurements, statistical significant between male and female, (p<0.001), the highest difference in mean between males and females was for the area of (max mrh) measurements the bicondylar the gender effect on these tested linear measurements was strong effect when evaluated by cohen's d for the effect size the usefulness of j bagh college dentistry vol. 28(3), september 2016 the usefulness of oral diagnosis 95 table 2:the gender differences in mean of unilateral linear mandibular ramus measurements variables gender difference in mean gender dimorphism cohen's d p female n=140 male n=140 mean max mrb 40.5 46.3 5.8 14.3 2.05 <0.001 min mrb 30 35 5 16.7 2.04 <0.001 max mrh 60.7 72.8 12.1 19.9 2.16 <0.001 projective hr 57.5 68.2 10.7 18.6 2.24 <0.001 ch 55.8 65.4 9.6 17.2 2.2 <0.001 table 3: the gender differences in mean of bilateral linear mandibular ramus measurements variables gender differen ce in mean gender dimorphism cohen's d p female n=140 male n=140 mean max mrb(mean of both sides) 40.5 46.3 5.8 14.3 2.05 <0.001 min mrb(mean of both sides) 30 35 5 16.7 2.04 <0.001 max mrh(mean of both sides) 60.7 72.8 12.1 19.9 2.16 <0.001 projective hr (mean of both sides) 57.5 68.2 10.7 18.6 2.24 <0.001 ch(mean of both sides) 55.8 65.4 9.6 17.2 2.22 <0.001 bicondylarb 111.3 124.3 13 11.7 2.17 <0.001 bigonialb 84.4 95.2 10.8 12.8 2.1 <0.001 ml 66 78.3 12.3 18.6 2.15 <0.001 mi 59.4 63.1 3.7 6.2 0.71 <0.001 roc analysis for unilateral and bilateral linear mandibular ramus measurements: receiver operating characteristic analysis (roc) was used to assess the validity of different tested measurements in predicting male sex differentiating from female. analysis was used to rank a set of linear measurements or parameters according to their validity in predicting male sex from female. among the computed tomography (max mrh) was the best parameter in predictinggender (roc=0.952cm) for both unilateral and bilateral measurements, as shown in table 4. while for transverse measurements the (bicondylar b) was the best parameter in predicting gender (roc=0.941cm), according to their validity in predicting male sex from female, as shown in table5. table 4:roc area for unilateral linear mandibular ramus measurements when used as test for gender identification roc area p maximum mandibular ramus height 0.952 <0.001 projective height of mandibular ramus 0.940 <0.001 coronoid height 0.939 <0.001 maximum mandibular ramus breadth 0.935 <0.001 minimum mandibular ramus breadth 0.921 <0.001 the discriminant function analysis of unilateral and bilateral mandibular ramus measurements in predicting sex for all parameters used in both unilateral measurements (hemi-mandible) and bilateral measurements (intact complete mandible), the percentage of accuracy according to discriminantfunction analysis was high (94.3% and 97.1%.) respectively with highly significant p-value (p<0.001) to differentiate between male and female. the age shows no statistical significance difference in mean values of selected measurements between the four age groups for both unilateral and bilateral measurements. j bagh college dentistry vol. 28(3), september 2016 the usefulness of oral diagnosis 96 table 5: roc area for selected bilateral linear measurements of mandibular ramus when used as test for gender identification roc area p maximum mandibular ramus breadth-mean of both sides 0.946 <0.001 minimum mandibular ramus breadth-mean of both sides 0.925 <0.001 maximum mandibular ramus height-mean of both sides 0.952 <0.001 projective height of mandibular ramus-mean of both sides 0.944 <0.001 coronoid height-mean of both sides 0.942 <0.001 bicondylar breadth 0.941 <0.001 bigonial breadth 0.931 <0.001 mandibular length 0.932 <0.001 mandibular index 0.690 <0.001 discussion the identification of sex from human remains is of fundamental importance in forensic medicine and anthropology, especially in the identification of missing persons. when the entire adult skeleton is available for analysis, sex can be determined up to 100% accuracy, but in cases of mass disasters where usually fragmented bones are found, sex determination with 100% accuracy is not possible and it depends largely on the available parts of skeleton. one of the important aspects of forensics is to determine sex from fragmented jaws and dentition (10,12). it has been established that socioenvironmental factors (e.g. nutrition, food, climate, pathologies, etc.) influence the development, and thus the appearance of bones. numerous studies have demonstrated that skeletal characteristics differ in each population and have emphasized the need for population-specific osteometric standards for sex determination(13). myers et al.(14)demonstrated that ct allows investigation of anatomic structures that are not easily available by autopsy and allows accurate analysis of bony structures in axial, coronal and sagittal planes with three-dimensional image of the inside of an object from a large series of twodimensional radiographic images taken around a single axis of rotation. rocha et al. (15)reported about the use of 3d ct reconstructions of linear craniometrical measurements in sex determination demonstrated a low standard error of those measurements and the results obtained from osseous and soft tissue structures were considered to be precise in 3d-ct with high imaging quality and resolution. in the present study selection of the mandible in gender difference related to the fact that it is the most dimorphic, largest, and strongest bone of skull. male bones are generally bigger and more robust than female bones. dimorphism in mandible is reflected in its shape and size, the shape of the mandible is created by the sequential structural modeling while the other bones are increasing in size (12). in the current study the 2 categories for sex identification were designed, the first category; include only one side of the mandible right or left side (hemimandible) which was available for examination. in the second category both sides of the mandible were present (intact complete mandible), so complete mandible was used for examination, all the measurements for (hemi and intact mandible) showed statistical significant differences between males and females with higher mean value for male as compared for females, (p<0.001), and the higher difference in mean was for the area of (max mrh) and (bicondylar b). our findings were in agreement with studies done by annamalai et al.(3) performed on various linear measurements, measured on the mandibular ramus, showed statistically significant sex difference between males and females, with highest mean difference for the area of (max mrh), they stated that ramus height expresses strong sexual dimorphism. the mandibular ramus demonstrated greatest univariate sexual dimorphism in terms of (max mrh), this may be attributed to the fact that the relative development (size, strength, and angulations) of the muscles of mastication is known to influence the expression of mandibular height dimorphism as masticatory forces exerted are different for males and females. any site of mandibular bone deposition, resorption, or remodeling for that matter, seems to have a potential for becoming sexually dimorphic. hence, mandibular ramus height in particular are generally the most sexually dimorphic, as they are the sites associated with the greatest morphological changes in size and remodeling during growth(12). vinay et al. (16)in their studyon undamaged human mandibles (175 males and 75 females), the measures with greatest dimorphism were ( bicondylar b) of mandible which was 115 mm in j bagh college dentistry vol. 28(3), september 2016 the usefulness of oral diagnosis 97 males and 103 mm in females, the mean values of male significantly higher than for females with a very strong effect of cohen's d. for the (ml), jayakaran et al.(17) in their studies on 207 mandible found that the mean of (ml) for male mandible was 78.4 mm and for female was 68.6 mm .the mean difference between male and female was 9.8 mm. this study showed statistically significant difference between male and female mandible in the area of (ml). the difference in mean value of male mandible in this study was almost similar to the current study. ranganath et al. (18) in their study on 111 mandibles (65 males, 46 females) showed that the mean for (bigonial b) for male was 93.8 mm and for females was 86.2 mm, the difference in mean between male and female was7.6 mm, this study agreed with the current study in reflecting the importance of (bigonialb), so this parameter had an important role in sex differentiation in several studies. the validity of linear mandibular ramus measurements in predicting male sex from female receiver operating characteristic analysis (roc) was used to assess the validity of different tested measurements in predicting male sex differentiating from female. the use of roc curve to find the optimal cutoff value for sex discrimination (classification of male and female) in each variable and comparing the performance of each variable. in the present study the (max mrh) was associated with highest validity in the context of gender identification, which establishes the diagnosis of male with 90.0% confidence. giles (19) measured mandibles of known sex using anthropometric measurements and reported (max mrh) as highly significant, with an accuracy of 85% in american whites and negroes, this study agreed with the current study in conclusion that (max mrh) to be the best parameter in sex determination. among transverse measurements of the mandible (bicondylar b) was the best parameter in predicting gender, which establish the diagnosis of male with 89.6 % confidence. steyn and iscan(20) achieved an accuracy of 81.5% with five mandibular parameters (i.e. bigonial b, ml, bicondylar b, min mrb, and gonion–gnathion) in south african whites, which is comparable with the current study results. dayal et al. (21)found mandibular ramus height to be the best parameter in their study, with 75.8% accuracy. discriminant analysis of the linear mandibular ramus measurements in predicting sex in this study, mandibular ramus measurements were subjected to discriminant function analysis. each of the parameters measured on mandibular ramus using 3d reconstructed image of spiral ct showed statistically significant sex differences between sexes, indicating that ramus expresses strong sexual dimorphism and able to predict gender with an overall accuracy of 94.3% for hemimandible, while for the intact complete mandible the accuracy was 97.1%. frankiln et al. (13) reported a very high accuracy of 95% with 10 variables employing geometric morph metric technique on south african population. in their study the (max mrh) showed an average accuracy of 87.5%, which is comparable with the current study. saini et al. (11) conducted a study on northern part of india and found that ramus expresses strong sexual dimorphism in this population. the parameters were max mrh, ch, and projective hr. references 1. scheuer l. application of osteology to forensic medicine.clinanat 2002; 15 (4):297-312. 2. rogers tl. determining the sex of human remains through cranial morphology. j forensic sci 2005; 50(3): 493-500. 3. annamalai pi, archana m, maria p. mandibular ramus: an indicator for sex determination a digital radiographic study. j forensic dent sci 2012; 4(2): 58–62. 4. dorota lm, wojciech k, czesław z, marzena l, małgorzata kk, monica ag, agnieszka p. the conclusive role of postmortem computed tomography (ct) of the skull and computer-assisted superimposition in identification of an unknown body.int j legal med 2013; 127(3): 653–60. 5. loth sr, henneberg m. mandibular ramus flexure: a new morphologic indicator of sexual dimorphism in the human skeleton. am j physanthropol 1996; 99(3):473–85. 6. dedouit f, telmon n, costagliola r, otal p, florence ll, joffre f,rougé d. new identification possibilities with postmortem multislice computed tomography. int j legal med 2007; 121(6): 507–10. 7. smith dr, limbird kg, hoffman jm. identification of human skeletal remains by comparison of bony details of the cranium using computerized tomographic (ct) scans. j forensic sci 2002; 47(5): 937–9. 8. sidler m, jackowski c, dirnhofer r, vock p, thali m. use of multislice computed tomography in disaster victim identification—advantages and limitations. forensic sciint 2007; 169(2–3):118–28. 9. woźniak k, moskała a, urbanik a, kopacz p, kłys m. 3d: nowadrogarozwojuklasycznejmedycynysądowej? arc h med sądkrym 2008; 59(2):124–30. j bagh college dentistry vol. 28(3), september 2016 the usefulness of oral diagnosis 98 10. vodanovic m, demo z, njemirovskij v, et al.odontometrics: a useful method for sex determination in an archaeological skeletal population?. j archaeolsci 2006; 34:905-13. 11. saini v, srivastava r, rai rk, shamal sn, singh tb, tripathi sk. mandibular ramus: an indicator for sex in fragmentary mandible. j forensic sci 2011; 56 (suppl1):s13–6. 12. humphrey lt, dean mc, stringer cb. morphological variation in great ape and modern human mandibles.janat 1999; 195:491–513. 13. franklin d, o’higgins p, oxnard ce. discriminant function sexing of the mandible of indigenous south africans. forensic sciint2008; 179(1): 84–5. 14. myers jc, okoye mi, kiple d, kimmerle eh, reinhard kj. three-dimensional (3-d) imaging in post-mortem examinations: elucidation and identification of cranial and facial fractures in victims of homicide utilizing 3-d computerized imaging reconstruction techniques. int j legal med 1999; 113(1): 33–7. 15. rocha s, ramos dl, cavalcanti mg. applicability of 3d-ct facial reconstruction for forensic individual identification. pesquiodontol bras 2003; 17(1):24-8 16. vinay g., mangalagowri s.r., anbalagan j. sex determination of human mandible using metrical parameters. j forensic sci 2013; 112(12): 2671– 267332. 17. jayakaran f, rajangam s, janakiram s, thomas im. sexing of the mandible.anatomica karnataka 2000; 1(1): 11–6. 18. ranganath, ravindranath y, ravindranath r. sexual dimorphism in mandibular morphology: a study on south indian sample. south asian anthropol 2008; 8(1):9–11. 19. giles e. sex determination by discriminant function analysis of the mandible. am j physanthropol1964; 22:129–35. 20. steyn m, iscan my. sexual dimorphism in the crania and mandibles of south african whites. forensic sciint 1998; 98:9–16. 21. dayal mr, bidmos ma. discriminating sex in south african blacks using patella dimensions.foresicsci 2005; 50(6):1294-7. 2linz f.docx j bagh college dentistry vol. 28(3), september 2016 effect of acidic and restorative dentistry 8 effect of acidic and energy drinks on surface roughness of three types of bulk fill composite materials linz a. shalan, b.d.s., m.sc. (1) abstract background: this study aimed to study the effect of some acidic drinks (vinegars and fresh orange juice) and energy drinks (red bull) on surface roughness of three types of bulkfill composite materials: filtek posterior bulkfill (3m), sonicfill (kerr) and filtek p60 (3m). materials and methods: total number of 120 samples are prepared by using a mold of (12mm diameter and 3mm height), which were divided into three groups forty samples for each group: group a: filtek bulkfill posterior composite (3m), group b: sonicfill composite (kerr), group c: filtek p60 (3 m) which then divided into four subgroups (n=10) (1) samples were kept in distilled water as a control group (2) samples were immersed in redbull (3) samples were immersed in fresh orange juice (4) samples were immersed in vinegars. immersion of samples were made manually for 5 seconds for 10 cycles at room temperature daily for one month then surface roughness was measured by the use of profilometer ,the data were recorded and statistically analyzed, by the anova and the tukey test. results: data were statistically analyzed using anova and tukey test which revealed that there were a high significant (p<0.001) increase in surface roughness of the three composite materials after immersion in vinegar and redbull drinks after one month with highest value for filtek bulkfill posterior composite (3m), than sonicfill composite (kerr) and filtek p 60 (3 m) and there was non-significant difference (p> 0.05) in surface roughness value for the three composite materials after immersion in fresh orange juice. conclusions: the effect of energy and acidic drinks depend upon exposure time, composition of the composite material keywords: energy drinks, bulkfill composite, red bull, roughness. (j bagh coll dentistry 2016; 28(3):8-14). introduction composite resins are widely used in restorative and pediatric dentistry. most of the available composites contain a polymer matrix of dimethacrylate monomers, such as bis-gma, udma, tegdma and bis-ema, inorganic filler particles coated with a methyl methacrylate functional silane coupling agent to bond the filler to the organic matrix, and a photoinitiator system to allow photoactivation by light units (1). to be clinically successful, restorative materials are required to have long-term continuousness, a quality which is strongly influenced not only by the intrinsic characteristics of the materials, but also by the environment to which they are exposed to (2). but the oral cavity is a complex, aqueous environment where the restorative material is in contact with saliva (3,4). in addition, other factors such as low ph due to acidic foods and drinks may influence the material’s mechanical and physical characteristics. in a clinical environment, a material’s decrease of hardness may contribute to its deterioration (5). however, "under in vivo conditions, composite resin materials may be exposed either discontinuously or continually to chemical agents found in saliva, food, and beverages (6). consequently, in the shortor longterm, these conditions may have a deleterious effect on the polymeric network, modifying its structure physically and chemically (3,4). (1) lecturer, department of conservative dentistry, college of dentistry, university of baghdad. physical characteristics of restorative materials are an important concern when determining suitable restorative materials because they strongly influence the clinical longevity of restorations (3). bulk-fill composites are popular restorative materials that have been on the market for several years. unlike traditional composites, which typically are placed in maximum increments of 2 mm, bulk-fill composites are designed to be placed in 4 mm, or sometimes greater increments. restoring a tooth in one step certainly appears to save time, there are some concerns. for example, manufacturers claim that bulk-fill materials have greater depth of cure and lower polymerizationinduced shrinkage stress (3). bulk fill composite had the advantages of time saving and easy handling, nowadays bulk fill composites become widely used amongst practitioners. however, only few studies were published on comparing the light-curing efficiency and mechanical properties of the commercially available bulk fill composite. therefore, the aim of the this study is to evaluate the surface roughness of three types of bulkfill composite: filtek bulkfill posterior composite (3m), sonicfill composite (kerr) and filtek p 60 (3m) after immersion in acidic solutions used daily by people such as energy drinks redbull (due to it is consumption has gained high popularity among the adolescent population especially 18-35 years olds in recent years) (6), vinegars, orange juice for 1 month. j bagh college dentistry vol. 28(3), september 2016 effect of acidic and restorative dentistry 9 materiala and methods three bulkfill materials were used filtek bulkfill (3m), sonicfill composite (kerr) and filtek p60 (3m) their composition and shade presented in table (1), the acidic solution used in this study their composition, ph presented in table (2). table 1: composition of the tested materials and drinks used in this study products the resin matrix the filler manufacture filler loading wt/vol filler size shade filtek bulk fill, posterior restorative audma, udma, and 1, 12-dodecanedma. silica filler, a zirconia fill and ytterbium trifluoride filler 3m espe, st. paul, usa 76.5% wt 4-20 nm a3 sonic fill bis-ema tegdma silicon dioxide glass, oxide, chemicals zirconium compound ytterbium triflouride kerr 83% wt 0.4-30 nm a3 filtek p60 bis gma,udma and bis-ema zirconia/silica 3m espe, st. paul, usa 83 % wt 0.19-3.5 µm a3 table 2: acidic drinks used in this study grouping: group a: 40 samples were made from filtek bulkfill posterior composite (3 m) group a1: 10 samples were immersed in distilled water (control group) group a2: 10 samples were immersed in red bull energy drinks group a3: 10 samples were immersed in orange juice. group a4: 10 samples were immersed in vinegar. group b: 40 samples were made from sonicfill comoposite ( kerr) group b1: 10 samples were immersed in distilled water (control group) group b2: 10 samples were immersed in red bull energy drinks group b3: 10 samples were immersed in orange juice. group b4: 10 samples were immersed in vinegar. group c: 40 sample were made from filtek p60 (3m) group c1: 10 samples were immersed in distilled water. group c2: 10 samples were immersed in red bull energy drinks group c3: 10 samples were immersed in orange juice. group c4: 10 samples were immersed in vinegar. samples preparation: by utilizing cylindrical teflon molds (3mm in height and 12mm in diameter) (8).the molds were placed on a transparent celluloid strip that fixed on a glass cement slab. the materials were inserted and pressed into the mold until it were intentionally overfilled. then the materials were covered with another celluloid strip and a glass microscopic slide. 100 gm pressure was applied to expel excess material from the mold. each specimen were light-cured by led (wood pecker, china) with 600 mw/cm2 for 20 second for all tested materials as recommended by their manufacturerיs through the application of the tip of light cure directly on the top glass slide (distance about 1.2mm, which is the thickness of the glass slide and celluloid strip), all samples were stored in vials that contained distilled water (ph 6.58) in an incubator at 37 οc for 24 hours before they were tested. the acidity of solutions were measured with a ph meter (model 3320). the ph meter was calibrated using test solutions of known ph (fisher scientific international, loughborough, uk) (8) immersion of specimens in solutions one group was stored in vials containing 5 ml of distilled water and kept in an incubator at 37°c as a control group and the distilled water material composition ph manufactures red bull sucrose, glucose, acidity regulatory sodium, citric acid, caffine, vitamins, natural flavours, colors 3.11 gmbh, austeria fresh orange juice carbohydrate, proteins, vitamins, minerals, citric acid, water 3.5 hand made apple vinegars acetic acid 5-8%, water and flavoring 2.5 zer, turkey j bagh college dentistry vol. 28(3), september 2016 effect of acidic and restorative dentistry 10 was renewed daily up to 1-month. the other specimens from each experimental group were individually immersed in vials containing 5ml of energy drinks red bull, vinegars, orange juice for 5 second daily at room temperature (23±1°c). after the immersion period in the test solutions, the samples were washed with distilled water and the specimens were maintained in distilled water at 37°c during the rest of the day. newly opened test solutions were used for each day, the phs of the solutions were measured daily with a ph meter (fisher scientific international, loughborough, uk) before immersing the specimens, for the entire experimental period, thereafter, in order to evaluate the change in surface hardness over time, surface roughness test were carried after 1monthafter the start of storage for the control (9) by the use of profilometer (federal mahr pocket surf, usa) figure (1) each sample was measured three times in various locations within the area of experimental zone, the roughness value ra was the average of these measurements in (µm). results statistics for tested composite materials descriptive statistics: means, standard deviation, minimum, maximum of surface roughness values for the three tested composite materials are listed in table (3). the results showed that there was increasing in means of roughness values of all types of composite after immersion in acidic drinks, also the data revealed that the filtek p60 had the lowest roughness values and filtek bulkfill posterior composite had the highest value inferential statistics: statistical analysis of data by using anova test for all groups of tested composite revealed that there is a high significant differences (p< 0.001) in surface roughness values ra among the groups for each composite material after immersion in acidic drinks and distilled water which show a high significant differences in surface roughness ra values among the tested composite with as shown in table (3). figure 1: profilometer table 3: descriptive and anova test among the three tested composite groups subgroups descriptive statistics comparison n mean s.d. minimum maximum f-test p-value sig. bulk fill a1 10 0.15 0.01 0.14 0.16 329.974 .000 hs a2 10 0.27 0.02 0.25 0.29 a3 10 0.17 0.03 0.14 0.24 a4 10 0.39 0.01 0.37 0.40 sonic fill b1 10 0.09 0.02 0.07 0.12 179.791 .000 hs b2 10 0.18 0.02 0.16 0.21 b3 10 0.10 0.02 0.08 0.13 b4 10 0.28 0.02 0.25 0.31 p60 c1 10 0.05 0.02 0.02 0.08 28.147 .000 hs c2 10 0.07 0.01 0.06 0.08 c3 10 0.04 0.01 0.03 0.07 c4 10 0.10 0.02 0.08 0.12 the data revealed from anova test analyzed by tueky test for all tested material which showed that there was a high significant increase in surface roughness value ra of the three types of composite (p> 0.001) after immersion in both red bull and vinegar and there was non-significant differences (p< 0.05) in surface roughness value for the three materials after immersion in orange juice as shown in table (4) and fig (2). j bagj bagh college dentistry restorative dentistry figure another statistical analysis were made between the subgroups for the tested material to data tukey test which showed that there was a high significant increase in surface roughness h college dentistry restorative dentistry table figure 2: surface roughness of the three tested composite another statistical analysis were made between the subgroups for the tested material to table 5 data revealed from an tukey test which showed that there was a high significant increase in surface roughness control red bull orange juice vinger media h college dentistry restorative dentistry table 4: tueky : surface roughness of the three tested composite another statistical analysis were made between the subgroups for the tested material to 5: descriptive and anova test from anova test analyzed by tukey test which showed that there was a high significant increase in surface roughness groups bulk fill sonic fill p60 n a1 10 b1 10 c1 10 a2 10 b2 10 c2 10 a3 10 b3 10 c3 10 a4 10 b4 10 c4 10 subgroup s h college dentistry vol. 2 tueky test among the groups for the tested materials : surface roughness of the three tested composite another statistical analysis were made between the subgroups for the tested material to escriptive and anova test ova test analyzed by tukey test which showed that there was a high significant increase in surface roughness value a3 b3 c3 b2 c1 c2 subgroups a1 a2 b1 n mean 10 0.15 10 0.09 10 0.05 10 0.27 10 0.18 10 0.07 10 0.17 10 0.10 10 0.04 10 0.39 10 0.28 10 0.10 descriptive statistics vol. 28(3), september 11 test among the groups for the tested materials : surface roughness of the three another statistical analysis were made between the subgroups for the tested material to analyze the effect of each acidic drinks on the three teste consist of both descriptive and anova test, vinegars had the highest mean value for increasing surface roughness tested groups orange juice had the lowest increase in surface roughne materials. significant differences (p roughness increase for all tested composite materials. escriptive and anova test for acidic drinks on each material ova test analyzed by tukey test which showed that there was a high value (p< composite materials for each type of ac shown in table (6 m. differe a2 -0.12 a3 -0.02 a4 -0.24 a3 0.10 a4 -0.12 a4 -0.22 b2 -0.09 b3 -0.09 b4 -0.19 b3 0.08 b4 -0.09 b4 -0.18 c2 -0.02 c3 0.00 c4 -0.05 c3 0.03 c4 -0.03 c4 -0.05 subgroups s.d. minimum 0.01 0.14 0.02 0.07 0.02 0.02 0.02 0.25 0.02 0.16 0.01 0.06 0.03 0.14 0.02 0.08 0.01 0.03 0.01 0.37 0.02 0.25 0.02 0.08 descriptive statistics september 201 test among the groups for the tested materials analyze the effect of each acidic drinks on the three tested materials as shown consist of both descriptive and anova test, vinegars had the highest mean value for increasing surface roughness tested groups followed by red bull drink, while orange juice had the lowest increase in surface roughness values materials. anova test showed that there was a high significant differences (p roughness increase for all tested composite materials. for acidic drinks on each material <0.001) among the composite materials for each type of ac shown in table (6 m. differe p-value -0.12 .000 -0.02 .077 -0.24 .000 0.10 .000 -0.12 .000 -0.22 .000 -0.09 .000 -0.09 .759 -0.19 .000 0.08 .000 -0.09 .000 -0.18 .000 -0.02 .006 0.00 .895 -0.05 .000 0.03 .001 -0.03 .002 -0.05 .000 minimum maxim um f-tesrt 0.14 0.16 0.07 0.12 0.02 0.08 0.25 0.29 0.16 0.21 0.06 0.08 0.14 0.24 0.08 0.13 0.03 0.07 0.37 0.40 0.25 0.31 0.08 0.12 82.835 398.052 99.862 669.949 2016 test among the groups for the tested materials analyze the effect of each acidic drinks on the d materials as shown consist of both descriptive and anova test, vinegars had the highest mean value for increasing surface roughness followed by red bull drink, while orange juice had the lowest increase in surface values on all the tested composite anova test showed that there was a high significant differences (p< roughness increase for all tested composite for acidic drinks on each material ) among the subgroup of the composite materials for each type of ac shown in table (6) and fig (3). p-value sig hs ns hs hs hs hs hs ns hs hs hs hs hs ns hs hs hs hs f-tesrt p-value .000 82.835 .000 .000 398.052 .000 99.862 669.949 comparison effect of test among the groups for the tested materials analyze the effect of each acidic drinks on the d materials as shown in table (5 consist of both descriptive and anova test, vinegars had the highest mean value for increasing surface roughness value ra on all the followed by red bull drink, while orange juice had the lowest increase in surface on all the tested composite anova test showed that there was a high < 0.001) in surface roughness increase for all tested composite for acidic drinks on each material subgroup of the composite materials for each type of acidic drinks as ). p-value sig comparison hs hs hs hs effect of acidic and analyze the effect of each acidic drinks on the in table (5), which consist of both descriptive and anova test, vinegars had the highest mean value for on all the followed by red bull drink, while orange juice had the lowest increase in surface on all the tested composite anova test showed that there was a high ) in surface roughness increase for all tested composite subgroup of the tested idic drinks as acidic and j bagj bagh college dentistry restorative dentistry table 6 the tested materials according to acidic fig. 3 drinks on the three tested composite another analysis were difference immersion in all tested drinks equation: after the data revealed tha all tested composite materials water fol δ ra of roughness increase was in vinegars and red bull drinks as shown in table (7 table 7 before surface roughness values. vinger control red bull media orange juice 0 0.1 0.2 0.3 0.4 h college dentistry restorative dentistry 6: tukey test between the subgroup of the tested materials according to acidic 3: chart show drinks on the three tested composite another analysis were difference of roughness increasing immersion in all tested drinks ation: after-before= δ ra the data revealed tha all tested composite materials followed by the orange juice and the highest of roughness increase was in vinegars and bull drinks as shown in table (7 7: δ ra difference before surface roughness values. b1 c1 b1 c1 b2 c2 b2 c2 b3 c3 b3 c3 b4 c4 b4 c4 a4 a1 a2 subgroups orange juice a3 0 0.1 0.2 0.3 0.4 distilled water red bull effect of acidic drinks on surface roughness of the three composite filtek bulk fill h college dentistry restorative dentistry tukey test between the subgroup of the tested materials according to acidic drinks showed the effect of acidic drinks on the three tested composite another analysis were made to determine the of roughness increasing immersion in all tested drinks before= δ ra(6) the data revealed that the lowest all tested composite materials was in distilled lowed by the orange juice and the highest of roughness increase was in vinegars and bull drinks as shown in table (7 : δ ra difference between after and before surface roughness values. b1 0.06 c1 0.10 c1 0.04 b2 0.09 c2 0.20 c2 0.11 b3 0.07 c3 0.13 c3 0.06 b4 0.11 c4 0.29 c4 0.18 mean difference red bull fresh orange juice effect of acidic drinks on surface roughness of the three composite filtek bulk fill sonic fill h college dentistry vol. 2 tukey test between the subgroup of the tested materials according to acidic the effect of acidic drinks on the three tested composite made to determine the of roughness increasing δ ra after immersion in all tested drinks by using this lowestδ ra value was in distilled lowed by the orange juice and the highest of roughness increase was in vinegars and bull drinks as shown in table (7) and fig (4 between after and before surface roughness values. .000 hs .000 hs .000 hs .000 hs .000 hs .000 hs .000 hs .000 hs .000 hs .000 hs .000 hs .000 hs sigp-value fresh orange juice vinegar effect of acidic drinks on surface roughness of the three composite filtek p60 vol. 28(3), september 12 tukey test between the subgroup of the effect of acidic made to determine the after by using this for was in distilled lowed by the orange juice and the highest of roughness increase was in vinegars and (4). between after and fig composite after immersion in acidic drinks discussion physical and chemical properties, surface roughness is still the limitation on the longevity of the restoration materials roughness solutions (4) base line surface roughness measurements mean values for filtek composite were ( were (0. (0. values (ra) than bulk fill posterior composite attributed to of filler content present in filtek p 60 then composite then filtek bulkfill posterior composite, of previous studies of composite is related to the size of filler parti particles exhibited higher surface roughness. effect of silane surface treatment on the fillers surface degradation may be happened when the filler and the bonded, this might be attributed to insufficient surface treatment with silane was thought to result in filler erosion and it has been suggested that silanization of filler particles plays an important role as does the type of based composites influence of distilled water on the three types of composite: surface roughness value materials than the other acidic drinks september 201 fig. 4: a chart show composite after immersion in acidic drinks discussion despite the improvement in composite resins physical and chemical properties, surface roughness is still the limitation on the longevity of the restoration(10) materials have shown roughness value solutions for 1month ). ase line surface roughness measurements in this study the baseline surface roughness mean values for filtek composite were ( were (0.09)µm (0.046)µm as shown in table filtek p 60 had the lowest values (ra) than lk fill posterior composite attributed to (1) of filler particles content present in filtek p 60 then composite then filtek bulkfill posterior composite, these result of previous studies of composite is related to the size of filler particles with increasing of filler size and volume particles exhibited higher surface roughness. (2) type of resin matrix effect of silane surface treatment on the fillers surface degradation may be happened when the filler and the bonded, this might be attributed to insufficient surface treatment with silane was thought to result in filler erosion and it has been suggested that silanization of filler particles plays an important role as does the type of based composites influence of distilled water on the three types of composite: distilled water ex surface roughness value materials than the other acidic drinks 0 0.1 0.2 0.3 distilled water filtek bulkfill 2016 chart showed composite after immersion in acidic drinks for one month. discussion despite the improvement in composite resins physical and chemical properties, surface roughness is still the limitation on the longevity of (10),in this study all tested composite have shown increase value after immersion in acidic for 1month as shown in table (7 ase line surface roughness measurements in this study the baseline surface roughness mean values for filtek composite were (0.14)µm for sonic fill composite µm and for filtek p 60 were as shown in table filtek p 60 had the lowest values (ra) than sonic fill lk fill posterior composite (1) the size, volume and distribution particles, from table (1 content present in filtek p 60 then composite then filtek bulkfill posterior these results agreed with the findings of previous studies (10) who found that roughness of composite is related to the size of filler cles with increasing of filler size and volume particles exhibited higher surface roughness. of resin matrix effect of silane surface treatment on the fillers surface degradation may be happened when the filler and the matrix resin were too weakly bonded, this might be attributed to insufficient surface treatment with silane was thought to result in filler erosion and it has been suggested that silanization of filler particles plays an important role as does the type of the resin used in the resin based composites (11). influence of distilled water on the three types distilled water exhibited less reduction on surface roughness value ra materials than the other acidic drinks distilled water red bull filtek bulkfill sonic fill effect of δ ra for the three composite after immersion in acidic drinks for one month. despite the improvement in composite resins physical and chemical properties, surface roughness is still the limitation on the longevity of in this study all tested composite increase in their surface after immersion in acidic as shown in table (7 ase line surface roughness measurements in this study the baseline surface roughness mean values for filtek bulkfill for sonic fill composite and for filtek p 60 were as shown in table (7). filtek p 60 had the lowest surface roughness composite and filtek lk fill posterior composite which could be , volume and distribution table (1) the high filler content present in filtek p 60 then composite then filtek bulkfill posterior s agreed with the findings who found that roughness of composite is related to the size of filler cles with increasing of filler size and volume particles exhibited higher surface roughness. of resin matrix (table 1) and effect of silane surface treatment on the fillers surface degradation may be happened when the matrix resin were too weakly bonded, this might be attributed to insufficient surface treatment with silane was thought to result in filler erosion and it has been suggested that silanization of filler particles plays an important the resin used in the resin influence of distilled water on the three types hibited less reduction on of the three composite materials than the other acidic drinks fresh orange juice vinegar sonic fill filtek p60 effect of acidic and δ ra for the three composite after immersion in acidic drinks despite the improvement in composite resins physical and chemical properties, surface roughness is still the limitation on the longevity of in this study all tested composite in their surface after immersion in acidic as shown in table (7) and fig. ase line surface roughness measurements in this study the baseline surface roughness posterior for sonic fill composite and for filtek p 60 were surface roughness composite and filtek which could be , volume and distribution the high filler sonicfill composite then filtek bulkfill posterior s agreed with the findings who found that roughness of composite is related to the size of filler cles with increasing of filler size and volume particles exhibited higher surface roughness. and (3) the effect of silane surface treatment on the fillers, so surface degradation may be happened when the matrix resin were too weakly bonded, this might be attributed to insufficient surface treatment with silane was thought to result in filler erosion and it has been suggested that silanization of filler particles plays an important the resin used in the resin influence of distilled water on the three types hibited less reduction on of the three composite after one vinegar filtek p60 acidic and j bagh college dentistry vol. 28(3), september 2016 effect of acidic and restorative dentistry 13 month as shown in table (7) and figure (4) in which filtek p 60 had a lowest δ ra (0.001) µm then sonicfill composite had δ ra value (0.002)µm and filtek bulkfill posterior composite had δ ra value (0.01) µm this represent the lowest values for increasing surface roughness as compared to the other tested drinks and this can be explained by(1) neutral ph for water (12) (2) another explanation to this increasing in ra values may be attributed to the water absorption and hydrolytic degradation of the filler surface caused by filler/matrix cracking, this depend on type of resin such as udma exhibit functional groups (i.e. hydroxyls) that are prone to form hydrogen-bond with water molecules (11), thereby being able to absorb and retain in their resultant polymers a certain amount of water (13), bis-gma copolymer is highly susceptible to chemical softening, with a broad increasing range of solubility parameters. the extent of softening of bis-gma copolymer depended on the soaking chemicals, bisema (ethoxylated bis-phenol a methacrylate) unlike the bis-gma, does not present the pendant hydroxyl groups that form the hydrogen bonds among the molecules and increase viscosity (14). as shown in table (1) filtek bulkfill posterior composite resin composed mainly from udma while sonicfill resin mainly bis-ema while filtek p60 resin composed from bis-gma, udma and bis-ema. this results are in agreement with previous studies (13,15,16). also resin composite materials that can absorb water capable of absorbing other acidic fluids resulting in surface degradation.it is assumed that water acts as a conductor for the acidic penetration into the resin matrix (13). distilled water was selected instead of artificial saliva to simulate the washing effect of saliva and also the artificial saliva storage medium is not considered to be a more clinically relevant environment, in addition previous studies (13) evaluated the influence of storage media upon the micromorphology of the resin based materials and achieved similar results for distilled water and artificial saliva influence of acidic drinks on the three types of composite: in this study surface roughness values for the three composite materials had a high significant increase after immersion in vinegars than red bull drinks and the lowest increase in fresh orange juice after 1 month, with highest mean value for filtek bulkfill posterior composite than sonicfill composite and the lowest mean value for filtek p60 as shown in tables (5, 6) and figure (3). this can be related (1) potency of the acidic drinks, it is assumed that this finding is related to the titratable acidity as shown in table (2), in which vinegars had lowest ph value (2.5), red bull had ph value of (3.11) and fresh orange juice had ph value of (3.5). the probable mechanism of acidity in composite resin degradation may be explained by the hydrolysis of ester radicals present in dimethacrylatemonomer, i.e. bis-gma, bis-ema, udma and tegdma. although previous studies assumed ph as a reliable indicator of the acidity of the drinks, this parameter gives only the initial concentration of +h ions and does not represent the presence of undissociated acid in the medium. so titratable acidity can be considered as amore accurate measure of the total acid content present in substances and may represent their erosive effect more realistically this finding is in agreement with previous studies (17). (2) chemical composition,the kind of acid in the solutions might have reduced the surface hardness of the tested restorative materials. it has been reported that organic fillers can be damaged by citric acid (18). in this study energy drinks contained citric acid and low ph value (3.11) as shown in table (2) they were found to be the one of the most aggressive storage medium for the composite as in tables (5,7) and figures ( 3,4) they have highly significant effect on surface roughness value ra and δra on the tested composite materials and this finding in agreement with previous studies (17,18) also an attempt to decrease erosion potential of beverage have been made by adding calcium, increasing their ph or adding ingredients such as casein, phosphopeptide stabilized amorphous calcium phosphate(19). for orange juice there was non -significant increase in surface roughness value ra and δ ra as shown in tables (3,5,6) and diagrams of the three composite materials in spite of it is acidity (contain citric acid) and (3.5) ph value as shown in table (2)this result could be due to it is calcium and phosphours content(17). this finding in agreement with (17,19,20). vinegar have (acetic acid 5-8%) and lowest ph value (2.5) among the tested drinks as shown in table (2) and have a highly significant increase in surface roughness value ra for all tested material as shown in tables (4,5,7) although acetic acid is a weak acid but the speciation of weak acids in aqueous systems is depend on solution ph also the erosive capability of acidic drinks will be determined by the individual ph value, titratable amount of base as well as the phosphate and fluoride content (17). this result was agreed with previous studies (17). finally it is important to notice that surface roughness means measure between 0.5 to 10 j bagh college dentistry vol. 28(3), september 2016 effect of acidic and restorative dentistry 14 (clinically unacceptable) were sufficient for retaining most of bacteria and thus not protected against removal forces (21). in this study δ ra and ra values before and after table (7) showed that all the tested materials had values of δ ra and ra parameter which is clinically acceptable. in conclusion, all types of acidic drinks used in this study can cause surface degradation on composite material. the effect of energy and acidic drinks depend upon it is composition and acidity. references 1. catelan a, briso al, sundfeld rh, santos ph. effect of artificial aging on the roughness and microhardness of sealed composites. j esthet restor dent 2010; 22: 324-30. 2. voltarelli fr, santos-daroz cb, alves mc, cavalcanti an, marchi gm. effect of chemical degradation followed by tooth brushing on the surface roughness of restorative composites. j appl oral sci 2010; 18: 585-90. 3. miranda da, bertoldo ce, aguiar fh, lima da, lovadino jr. effects of mouthwashes on knoop hardness and surface roughness of dental composites after different immersion times. braz oral res 2011; 25:168-73. 4. didem a. gozde y. comparative mechanical properties of bulkfill resins. open j composite materials 2014; 4:117-21. 5. sarrett dc. a laboratory evaluation of bulk-fill versus traditional multi-increment–fill resin-based composites. ada 2013; 8: 13-26. 6. al-samadani khh. effect of energy drinks on the surface texture of nanofilled composite resin. j contemp dent pract 2013;14(5): 830-5. 7. ibarra e, lien w, vandewalle k, casey j, dixon s. physical properties of a new sonically activated composite restorative material. inter assoc dent res 2013; 3: 51-6. 8. ruschel vc, basso gr, de andrada mac, maia hp. effects of different polishing systems on the surface roughness and microhardness of a silorane-based composite. applied adhesion sci 2014; 2:7. 9. erdemir u, yildiz e, eren mm, ozel s. surface hardness evaluation of different composite resin materials: influence of sports and energy drinks immersion after a short-term period. j appl oral sci 2013; 21(2):124-31 10. valinot ac, neves bg. surface degradation of composite resin by acidic medicines and ph-cycling. j appl oral sci 2008; 16: 1-11. 11. erdemir u, yilidiz e. effect of sports drinks on color stability of nanofilled and micro-hybride composite after long term immersion. j dentistry 2012; 40(2): e55-e63. 12. turssi cp, hara at, serra mc. effect of storage media upon the surface micromorphology of resinbased restorative materials. j oral rehabil 2002; 29: 864-71. 13. ferracane jl. hygroscopic and hydrolytic effects in dental polymer networks. dent mater 2006; 22(3): 211–22. 14. ajaj ra. optical and surface properities of different bulk fill resin composite after storage in different media. j am sci 2015; 11(6): 249-54. 15. lepri cp, palma-dibb rg. surface roughness and color changes of a composite: influence of beverages and brushing. dental material j 2012; 31(4): 689-96. 16. catelan a, briso al, sundfield rh. effect of artificial aging on the roughness and microhardness of sealed composites. j esthetic restor dent 2010; 22: 324-30. 17. rahmati ana, shamsaei z, hashemi ap. destructive effects of citric acid, lactic acid and acetic acid on primary enamel microhardness. j dental school 2015; 33(1): 66-73. 18. cochrane nj. yuan y. walker gd. erosive potential of sport beverages. australin dent j 2012; 57:1-6. 19. larsen mj. prevention by means of fluoride of enamel erosion as caused by soft drinks and orange juice. caries res.2001; 35:229-34. 20. grobler et al. the effect of honey on human tooth enamel in vitro observed by electron microscopy and microhardness measurements. oral biol j 1994; 39(2):147-53. 21. rahal js, mesquita mf, henriques gep. surface roughness of acrylic resins submitted to mechanical and chemical polishing. j oral rehabil 2004; 31:10759. tuqa f.doc j bagh college dentistry vol. 25(2), june 2013 effect of ginger extract orthodontics, pedodontics and preventive dentistry179 effect of ginger extract on mutans streptococci in comparison to chlorhexidine gluconate tuqa akram weli, b.d.s. (1) ahlam taha mohammed, b.d.s., m.sc. (2) abstract background: the rhizome of ginger is used in cooking and for medicinal purposes such as anti-bacterial, anti-fungal, anti-inflammatory and antioxidant. the aims of the study were to test the effect of ethanolic extract of ginger on growth, adherence and acidogenicity of mutans streptococci in comparison to chlorhexidine gluconate 0.2% and de-ionized water. materials and methods: from saliva often volunteers (dental students 20-22 years); mutans streptococci was isolated, purified and diagnosed according to morphological characteristic and biochemical tests. ginger was powdered and extracted, different concentrations of ginger extract were prepared. chlorhexidine gluconate 0.2% used as a control positive; while de-ionized water was used as a control negative. in this study, in vitro and in vivo experiments were conducted. in vitro experiment, agar well technique was used to study the sensitivity of mutans streptococci to different concentrations of ginger extract and other control agents; also effect of ginger extract on the viable count of mutans streptococci, the adherence and acidogenicity of mutans streptococci were studied.in vivo experiment, the volunteers couldn’t tolerate the extract. results: mutans streptococci was sensitive to different concentrations of ethanolic ginger extract, but they were more sensitive to chlorhexidine gluconate than the extract. the effect of ginger extract on the viable count of mutans streptococci at concentrations (30%, 35% and 40%) showed highly significant reduction in the count of the bacteria but less than chlorhexidine effect. in the effect of the extract on the adherence of mutans streptococci, the concentrations (30%, 35%, 40%) were used and only 40% and chlorhexidine prevent the plaque formation. but in the acidogenicity of mutans streptococci procedure 35%, 40% of the extract and chlorhexidine showed effectiveness in reducing acid formation. conclusion: ginger extract was effective against mutans streptococci, chlorhexidine is more effective than other agents. keyword: mutans streptococci, ginger extract, chlorhexidine. (j bagh coll dentistry 2013; 25(2):179-184). introduction ginger, the underground stem or rhizome of the plant zingiberofficinale has been used to treat a wide array of ailments(1). it is one of the natural products having antimicrobial property against various human pathogens including oral pathogens like mutans streptococcus. mutans streptococci have the ability to generate considerable amount of acid as a result of their metabolism of carbohydrate, to survive in acid environment so they are considered as cariogenic microorganisms(2,3,4,5)and have a real role in dental caries, which is a disease in which the mineralized tissues of the tooth undergo progressive destruction from the surface of the tooth(6,7), initiated through a series complex, chemical and microbial reactions associated with dental plaque biofilms that containing a number of mutans streptococci(8). medicated oral rinse usually contains antimicrobial agents, such as chlorhexidine gluconate which is a very potent chemoprophylactic agent, it has a broad spectrum action especially against mutans streptococci group (9,10). (1) m.sc. student. department of pediatric and preventive dentistry, college of dentistry, baghdad university. (2) assistant professor, department of pediatric and preventive dentistry, college of dentistry, baghdad university. but it has many side effects like staining of the teeth, altering the test of the mouth and desquamation of oral mucosa (10). as plant sources have been considered to be safe with fewer side effects, so that use of antiplaque and anti-caries agents from plants has been investigated. hence in the present study an attempt has been made to explore the antimicrobial potential of ginger (zingiberofficinale) against mutans streptococcus andcompare it with chlorhexidine gluconate. materials and methods preparation of ginger extract the preparation of ethanolic extract of ginger carried out according to the method described by nweze and okafor (11), which involved the maceration of 100 gram of plant in 500 ml of absolute ethanol (ethanol 99.9%). the container was sealed with paper foil to prevent loss of volatile solvent and left at room temperature for 24 hr. at the end of this period, the contents were filtered using filter paper (no.1) into a beaker. the filtered solution then concentrated by evaporating the solvent in a hot air oven at 40°c for 24 hr. the extract powder was then weighed, kept in sterile bottles, labeled accordingly and stored in the refrigerator. j bagh college dentistry vol. 25(2), june 2013 effect of ginger extract orthodontics, pedodontics and preventive dentistry180 collection of saliva stimulated saliva was collected from ten healthy looking students aged (22-24) years(12). isolation of mutans streptococci the collected salivary samples were homogenized by vortex mixer for 1-2 minutes, then tenfold dilutions were performed by transferring 0.1 ml of saliva to 0.9 ml of phosphate buffer saline (ph 7.0), then from the dilution 10-3 of salivary samples 0.1 ml was taken and spread on the msba media, the plates were incubated anaerobically using a candle for 48 hr. at 37°c then incubated aerobically for 24 hr. at room temperature(13), the colonies of mutans streptococci were identified on the basis of the morphology of the colonies, gram's stain andbiochemicaltest (the ability of mutans streptococci to ferment sugar was tested by addition of selected types of sugar (sorbitol) in a concentration of 1% in brain heart infusion broth)(14). in vitro experiments a. sensitivity of mutans streptococci to different concentrations of ginger extract, chlorhexidine and de-ionized water. different concentrations of ginger extract in addition to chlorhexidine (0.2%) and de-ionized water were used in this experiment. a volume of 25 ml of mueller hinton agar was poured into sterile glass petridishes, left at room temperature for 24 hour. to each plate 0.1 ml of mutans streptococci inoculum was spread, left for 20 minute at room temperature then wells of equal size and depth were prepared in each plate, each well was filled with 0.2 ml of the test agents. plates were left at room temperature for one hour then incubated anaerobically for 24 hr. at 37°c, zone of inhibition was measured by using digital vernia. b. effect of ginger extract, chlorhexidine and deionized water on viable count of mutans streptococci. different concentrations of ginger extract were prepared. brain heart infusion broth (ph 7.0) was distributed in test tubes by 8.9 ml in each one. one ml of the test agent was added to each tube, after that 0.1 ml of bacterial inoculum was added to both study and control tubes. from the control tube 0.1 ml was transferred to 0.9 ml of sterile phosphate buffer saline (ph 7.0) and a ten–fold dilution was performed. from dilutions 10-3, 0.1ml was taken and spread in duplicate on mitis salivarius bacitracin agar plates, the plates then incubated anaerobically at 37°c for 48 hour. then colony forming unit per milliliter (cfu/ml) was counted, this value was considered as the initial count of bacteria. study and control were incubated aerobically at 37ºc for 24 hour. from each tube of the control and study 0.1 ml was transferred to 0.9 ml of phosphate buffer saline and a ten fold dilution was performed. from dilutions 10-3, 0.1 ml was taken and spread in duplicate on mitissalivarius bacitracin agar plates, the plates then incubated anaerobically at 37°c for 24 hour. the colony–forming unit per milliliter was counted (cfu/ ml) for all the plates. c. effect of ginger extract on adherence of mutans streptococci to tooth surface 1. different concentrations of ginger extract were prepared.stainless steel wire was threaded in one end in the root of previously cleaned and polished sound first premolar by using non fluoridated pumice. these all were sterilized by the autoclave. 2. teeth were immersed in 10 ml of the tested agents for two minutes except for control positive which was broth and bacteria without agents, the tested agents include ginger extract of concentrations (30%, 35%, 40%), chx 0.2%, and de-ionized water. 3. the wires and teeth were washed using sterile de-ionized water for one minute and left to dry for 5 minutes at room temperature. 4. the teeth were immersed in 10 ml brain heart infusion broth containing 5% sucrose (ph 7.0). the study and control tubes were inoculated with 0.2 ml (2%) of bacterial isolates. all the bottles were incubated aerobically at 37oc for seven days. d. effect of ginger extract on the acidogenicity of mutans streptococci 1. different concentrations of ginger extract were prepared. stainless steel wire was threaded in one end in the root of a previously cleaned and polished sound first premolar. 2. each sterilized wire and tooth inserted in a tube of 10 ml of brain heart infusion broth containing 5% sucrose at (ph 7.0), then inoculated with 2% of mutans streptococci except for the control negative which contain (5% sucrose broth with wire holding a tooth). the study and control broths were incubated at 37°c aerobically, for period of three days every 24hr. each wire holding a tooth was j bagh college dentistry vol. 25(2), june 2013 effect of ginger extract orthodontics, pedodontics and preventive dentistry181 transferred to a fresh 5% sucrose broth, incubated aerobically at 37°c this allowed for further accumulation of bacterial deposit. 3. in the fourth day, coated teeth in addition to the control negative were immersed about 2 minutes in 10 ml solutions of ginger extract (30%, 35%, 40%), chx 0.2% and de-ionized water. then wires and teeth were removed and washed with sterile de-ionized water for about one minute including control negative and control positive, teeth were left to dry at room temperature for 5 minutes then placed in a fresh 5% sucrose broth at (ph 7.0) containing 1% bromocresol purple as an indicator, test tubes were incubated for seven days at 37°c. positive reaction (acid formation) was indicated by the change in the color from purple to yellow. results were recorded as follows: (+) yellow no effect on acid production. (+,-) orange weak effect on acid production. (-) purple effective (preventing acid production). in vivo experiment the volunteers couldn’t tolerate the, they removed it immediately from their mouth because of hotness, burning and numbness of the mouth (as they described). statistical analysis data processing and analysis were carried out by using spss program, which provide the following: • calculation and presentation of statistical parameters: mean and sd of the variables in the study. • student’s t-test, paired t-test and analysis of variance (anova) for testing the significant differences among means of different groups. • for all the above mentioned tests, the analysis was accepted at p<0.05, as the level of significance. results sensitivity of mutans streptococci to different concentrations of ginger extract, chlorhexidine and de-ionized water diameter of inhibition zones for ethanolic extract of ginger (clear zone of no growth of mutans streptococci around each well) were found to be increased as the concentration of the extract increased. de-ionized water showed no zone of inhibition, while chx showed highest zones of inhibition compared to the ginger extract(table 1). lsd test among different concentrations of ginger extract, chx and d.w. shows statistically, highly significant differences were found among all groups used, except between (30% and 35%) there was non significant difference (table 2). effect of ginger extract, chx and de-ionized water on viable count of mutans streptococci the count of mutans streptococci was recorded before the application of the tested agents, this was considered as the initial count of bacteria. after 24hr. of incubation period, the number of mutans streptococci was counted (with study agents and without). paired t-test was used to compare between initial count of bacteria and the count after 24 hr. statistically highly significant increase in the number of bacteria was recorded after 24 hr. (without agent)(table 3). anova test was used to compare among count of bacteria after 24hr., ginger extract, chx and d.w. statistically highly significant difference was found among these groups (table 4). lsd test among these groups was done and statistically highly significant differences were found among all of them, except between (after 24 hr.-d.w) and (chx -40%) there were non significant differences (table 5). effect of ginger extract, chx and d.w on adherence ability of mutans streptococci the results of this experiment showed that dental plaque was detected by using dental probe only, which accumulated on the positive controlled teeth, de-ionized water and 30%, 35% ginger extract while negative controlled teeth, teeth immersed in 40% ginger extract and in chx showed no accumulation of dental plaque on them (table 6). effect of ginger extract, chx and d.w on acidogenicity of mutans streptococci in this experiment, the ginger extract at 35%, 40% and chx were effective in retardation of acid formation as were detected by the change in color from deep purple to orange , while for 30% ginger extract, de-ionized water and control +ve, the color was changed from deep purple to yellow, and the control –ve remained purple in color (table 7). j bagh college dentistry vol. 25(2), june 2013 effect of ginger extract orthodontics, pedodontics and preventive dentistry182 table 1: inhibition zones of mutans streptococci to different agents. agents mean* ± sd anova test ginger extract 30% 6.9760 0.27179 f =487.725 d.f= 7 p= 0.000 hs ginger extract 35% 7.475 0.3206 ginger extract 40% 8.234 0.372 ginger extract 45% 9.5110 0.2210 ginger extract 50% 10.294 0.4699 ginger extract 55% 11.2710 0.7264 chx 0.2% 13.0400 1.19112 d.w 0 0 *mean (mm). table 2: lsd test among different concentrations of ginger extract, chx and d.w. *mean (mm). table 3: initial count of bacteria and the count after 24 hr. (×104). mean* ±sd test initial count 259.40 28.737 t = -29.395 d.f= 4 p= 0.000 hs after 24 hr. count 945.60 76.891 *mean (cfu/ml). table 4: count of bacteria after 24 hr., with ginger extract, chx and d.w (×104). mean* ±sd anova test after 24 hr. count 945.60 76.891 f = 334.548 d.f= 5 p= 0.000 hs 30% 344.40 51.252 35% 230.40 40.104 40% 128.60 32.921 chx 88.80 15.434 d.w 965.60 54.413 *mean (cfu/ml). table 5: lsd test among the count of bacteria (×104) of different agents. concentration mean difference p description after 24hr.-d.w -20.000 0.525 ns chx 40% 39.800 0.212 ns table 6: effect of ginger extract, chx and d.w on adherence of mutans streptococci. agent 30% 35% 40% chx d.w control –ve control +ve adherence + + + + (+) presence of plaque (adherence). (-) absence of plaque (no adherence). table 7: effect of ginger extract, chx and d.w onacidogenicity of mutans streptococci. agent 30% 35% 40% chx d.w control –ve control +ve acidogenicity yellow orange orange orange yellow purple yellow yellow: no effect, orange: weak effect, purple: strong effect concentration mean difference p description 30% -35% -0.49900 0.051 ns j bagh college dentistry vol. 25(2), june 2013 effect of ginger extract orthodontics, pedodontics and preventive dentistry183 discussion the sensitivity of mutans streptococci to different concentrations of ethanolic extract of ginger in comparison to chx 0.2% and deionized water was tested using agar diffusion technique. ginger ethanolic extract was able to produce an antibacterial effect by inhibiting mutans streptococci isolated from human saliva. the diameters of the inhibition zones were found to increase when the concentration of the extract increased, this may be attributed tothe amount of the dissolved active constituents of the extract will be more abundant as the concentrations increase causing increased antibacterial activity of the extract. the first concentration was shown to inhibit the growth of the bacteria was 30%, although all the concentrations 30%, 35%, 40%, 45%, 50% and 55%were shown lower inhibition zone than chx 0.2%. the de-ionized water had zero effect on the bacteria appearing by absence of inhibition zone. in the effect of ginger extract, chx 0.2% and deionized water on the viable count of mutans streptococci, the result showed that a highly significant reduction in count of these bacteria at concentrations 30%, 35% and 40% of the ginger extract was seen compared to the control after 24hr. the antibacterial activity of ginger extract could be attributed to the chemical constituents of ginger like sesquiterpenoids with zingiberene as the main components and other components include β-sesquiphellandrene, bisabolene and farnesene(15). no significant difference in count of bacteria was seen for de-ionized water compared to control after 24hr., this could be explained by complete resistance of these bacteria for deionized water. the ability of mutans streptococci to adhere to host surfaces is the major virulence factor, which is important in colonization of them (16, 17, 18). it is of great importance to the development of carious lesions, and any interference with some of the mechanisms of adherence can prevent the formation of carious lesions (19, 20). in this study, the effect of ginger extract on the adherence of mutans streptococci was tested, the results showed that the concentrations 30% and 35% of ginger extract were unable to prevent adherence of bacteria, but there was a reduction in the thickness of plaque in comparison to the control. no plaque formed on teeth immersed in 40%, this may be attributed to the inhibitory effect of these agents on growth or metabolism of these bacteria. chx and control negative (broth and agent without bacteria) showed no plaque formation on teeth immersed in them, while plaque was formed on control positive teeth and teeth immersed in de-ionized water. the present study tested the effect of 30%, 35% and 40% ethanolic ginger extract, chx and de-ionized water on acid production by mutans streptococci. the results showed change in the color of the indicator from deep purple to yellow as in 30% ginger extract, de-ionized water and control positive teeth, and this indicate a failure in the prevention or retardation of acid formation by mutans streptococci, while 35%, 40% of ginger extract, and chx were able to change the color from deep purple to orange. control negative remained the color purple. references 1. shukla y, singh m. cancer preventive properties of ginger: a brief review. food chem toxicol 2007; 45(5): 683-90. 2. kidd e, fejerscove o. what constitutes dental caries: histopathology of carious enamel and dentine related to action of cariogenic bio film. j dent res 2004; 83: 35-38. 3. seminario a, broukal z, vancakova r. mutans streptococci and the development of dental plaque. prague medical report 2005; 106(4): 349-358. 4. marsh p. dental plaque as a biofilm and microbial community-implications for health and diseases. bmc oral health 2006; 6(1): 514. 5. stoodly p, debeer d, vonhole c. biofilm and hydrodynamic effects on mass transfer caries. jada 2008; 139(9): 1182-1190. 6. kidd e, bechal s. essential of dental caries. the disease and its managements. 2nd ed. new york: oxford university press inc; 2002. pp. 67-68, 143. 7. kleinberg i. a mixed bacteria ecological approach to understanding the role of the oral bacteria in dental caries. crit rev oral bio med 2002; 13(2): 108-125. 8. saraf s. textbook of oral pathology. jaypee brothers publishers; 2006. 9. fedele d, niessen l. periodontal treatment for older adults. in: newman m, takei h, carranza f (eds). carranza’s clinical periodontology. 9th ed. philadelphia: w. saunders; 2002. 10. pourabbas r, delazar a, chitsaz m. the effect of german chamomile mouthwash on dental plaque and gingival inflammation. iranian j pharm res 2005; 2: 105-109. 11. nweze e, okafor j. antifungal activities of a wide range of medicinal plants extracts and essential oils against scedosporiumapiospermum isolates. americaneurasian j of sc res 2010; 5(3):161-169. 12. tenovou j, lagerlof f. saliva. in: thylstrup a, fejerskov o. textbook of clinical cariology. 2nd ed. copenhang: munksgaard; 1996. pp. 17-43. 13. holbrook w, beighton d. streptococcus mutans levels in saliva and distribution of serotypes among 9 years old icelandic children. scan dent res 1986; 95: 37-42. 14. finegold s, baron e. methods for identification of etiologic agents of infectious disease. in bailey and j bagh college dentistry vol. 25(2), june 2013 effect of ginger extract orthodontics, pedodontics and preventive dentistry184 scotts (eds). diagnostic microbiology. 7th ed. st. louis: cv mosby co; 1986. pp.382. 15. o'hara, mary, kiefer, david, farrell, kim, kemper, kathi. a review of 12 commonly used medicinal herbs. archives family medicine 1998; 7(7): 523– 536. 16. mattos-graner r, li y, caulfield p, duncan m, smith d. genotypic diversity of mutans streptococci in brazilian nursery children suggests horizontal transmission. j clin microbiol 2001; 39: 2313-2316. 17. napimoga m, höfling j, klein m, kamiya r, gonçalves r. transmission, diversity and virulence factors of streptococcus mutans genotypes. j oral sci 2005; 47(2): 59-64. 18. law v, seow w, townsend g. factors influencing oral colonization of mutans streptococci in young children. aust dental j 2007; 52(2): 93-100. 19. slimestad r, fossen t. onions: a source of unique dietary flavonoids. j agric food chem 2007; 5: 10067-10080. 20. ferrazzano g, amato i, ingenito a, zarrelli a, pinto g, pollio a. plant polyphenols and their anticariogenic properties: a review. molecules j 2011; 16: 1486-1507. rihab f.doc j bagh college dentistry vol. 25(4), december 2013 salivary cortisol pedodontics, orthodontics and preventive dentistry126 salivary cortisol among low birth weight 5 years old kindergarten children in relation to dental caries (comparative study) rihab a. ali, b.d.s. (1) ban s. diab b.d.s., m.sc., ph.d. (2) abstract background: birth weight is a powerful predictor of infant growth and survival. evidence now shows that children born with low birth weight face an increased risk of chronic diseases and have many health problems including oral health. the aims of this study were to assess the salivary flow rate, viscosity, and salivary cortisol among low birth weight kindergarten children aged 5 years old in hilla centre, in relation to dental caries and compares them with the normal birth weight children of the same age and gender. materials and methods: the total sample involved 80 children (40 low birth weights and 40 normal birth weights) aged 5 years old. the diagnosis and recording of severity of dental caries was recorded through the application of d1-4mfs index according to the criteria described by mühlemann (1976). the stimulated saliva was collected from the total sample under standardized conditions and then analyzed for measuring salivary flow rate and viscosity, in addition to estimation of salivary cortisol by special cortizol kit using vidas® cortisol s. results: the mean rank of dmfs, ds, ms and fs were found to be higher among low birth weight than normal birth weight groups, with a statistically significant difference for dmfs, ds (p<0.05), highly significant difference for ms (p<0.01) and non significant difference for fs (p>0.05). concerning the ds grade, data analysis showed a significant difference only for d1 grade (p<0.05). salivary analysis demonstrated that the mean rank of salivary flow rate was found to be lower among the low birth weight than the normal birth weight groups with non significant difference (p>0.05). the viscosity of saliva was found to be highly significantly higher among low birth weight than normal birth weight groups (p<0.01). concerning salivary cortisol, data analysis showed that the mean rank was higher among low birth weight than normal birth weight groups. however, the difference was not significant (p>0.05). conclusion: the results of the current research revealed that low birth weight status affect oral health conditions. key words: low birth weight, dental caries, salivary flow rate, salivary viscosity, salivary cortisol. (j bagh coll dentistry 2013; 25(4):126-133). الخالصة الدالئل تشیر اآلن أن األطفال الذین یولدون مع انخفاض الوزن عند الوالدة یواجھون خطرا متزایدا من . وزن الوالدة یشكل مؤشرا قویا لنمو الرضع و البقاء على قید الحیاة : خلفیة ذه الدراسة تقییم معدل تدفق اللعاب ، واللزوجة ، والكورتیزول اللعابي بین انخفاض الوزن وكانت أھداف ھ. األمراض المزمنة ولھا العدید من المشاكل الصحیة بما في ذلك صحة الفم سنوات من العمر في مركز الحلة ، وعالقتھ بتسوس األسنان ومقارنتھا مع الوزن الطبیعي عند الوالدة لألطفال من نفس العمر 5عند الوالدة لریاض األطفال الذین تتراوح أعمارھم بین .والجنس وتم تسجیل شدة تسوس . سنوات 5الذین تتراوح أعمارھم بین ) عند الوالدة الطبیعي الوزن 40انخفاض الوزن عند الوالدة و 40(طفال 80تضمنت العینة الكلیة : المواد و الطرق ب المحفز من العینة الكلیة في ظل ظروف موحدة ومن ثم تحلیلھا لقیاس خالل تطبیق مؤشر وقد تم جمع اللعاd14mfs وفقا للمعاییر التي وصفھا mühlemann (1976) .األسنان من معدل تدفق اللعاب واللزوجة ، باإلضافة إلى تحلیل الكورتیزول اللعابي باستخدام كت خاص بالكورتیزول .vidas® cortisol s طفال الوزن الوزن عند الوالدة عنھ أل اطفال انخفاضلتكون أعلى عند ، وجدتعند الوالدة الطبیعيdmfs ،ds ،ms وfs وفرق معنوي كبیر للغایة msوفرق غیر معنوي فیما یخص fs وفیما یتعلق ds ، أظھر تحلیل البیانات فرقا معنویا فقط للرتبة تسوس السطوح لألسنان اللبنیةرتبة متوسط : النتائج معدل تدفق اللعاب وجدت لتكون أقل بین مجموعة انخفاض الوزن عند الوالدة من تحلیل اللعاب أن رتبة متوسط أظھر d1 . , مع وجود فرق دال إحصائیا dmfs, ds, فیما یخص ن لزوجة اللعاب وجدت لتكون أعلى بكثیر مع فارق معنوي كبیر للغایة بین مجموعة انخفاض الوزن عند الوالدة م. مجموعة الوزن الطبیعي عند الوالدة مع وجود فارق غیر معنوي موعة وفیما یتعلق بالكورتیزول اللعابي ، أظھر تحلیل البیانات أن رتبة متوسط الكورتیزول أعلى بین مجموعة انخفاض الوزن عند الوالدة من مج. مجموعة الوزن الطبیعي عند الوالدة .ومع ذلك ، كان الفارق غیر معنوي . الوزن الطبیعي عند الوالدة .ؤثر على األوضاع الصحیة للفمتلحالي أن حالة انخفاض الوزن عند الوالدة كشفت نتائج البحث ا: االستنتاج .زوجة اللعاب ، الكورتیزول اللعابيلانخفاض الوزن عند الوالدة، تسوس األسنان ، معدل تدفق اللعاب ، : الكلمات الرئیسیة introduction low birth weight (lbw) is a major determinant of mortality, morbidity and disability in infancy and childhood and also has a long-term impact on health outcomes in adult life. the consequences of poor nutritional status and inadequate nutritional intake for women during pregnancy not only directly affect women’s health status, but may also have a negative impact on birth weight and early development. low birth weight also results in substantial costs to the health sector and imposes a significant burden on society as a whole (1). (1) m.sc student department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. low birth weight defines a heterogeneous group of infants: some are born early, some are born growth restricted, and others are born both early and growth restricted. it is generally recognized that being born with low birth weight is a disadvantage for the baby (2). some authors defined low birth weight as baby weighting less than or equal to (2500 g) (3,4) while others defined lbw as a baby that weighs less than (2500 g) (up to and including 2499 g) regardless of gestational age (5,6). children with low birth weight are at risk for medical problems in childhood and adulthood and often have poor oral health. dental caries remain one of the major global public health problems. it is considered as multifactorial since it is influenced by dietary as well as host factors (7). however, the literatures contain contradictory j bagh college dentistry vol. 25(4), december 2013 salivary cortisol pedodontics, orthodontics and preventive dentistry127 results concerning the relation between lbw and dental caries. saraiva et al. (8), javadinejad et al. (9), and rajshekar and laxminarayan (10), reported that children born with lbw have higher caries experience in the primary dentition, whereas gravina et al. (11), and cruvinel et al. (12), found a greater prevalence of carious lesions in children born at full term than in children born prematurely. they suggested that low birth weight, including preterm births, predisposes to high levels of streptococcal colonization due to reduced immunofunction, in addition that the lbw favoring the development of enamel hypoplasia and salivary disorders (13,14). in contrast, burt and pai (15), peres et al. (16), and shulman et al. (17), concluded that no significant association is observed between low birth weight and dental caries. saliva is an ideal translational research tool and diagnostic medium as saliva is mirror of the serum and is being used in novel ways to provide molecular biomarkers for a variety of oral and systemic diseases and conditions (18-20). saliva contains various microbes and host biological components that could be used for caries risk assessment (21). saliva represents the first line of defense against dental caries after tooth eruption (22,23). in addition, saliva displays physical properties related to the maintenance of a healthy oral environment, including secretion rate and viscosity (24). this finding tends to support the hypothesis that the mechanism behind the increased risk of dental pathology in preterm, low birth weight and retarded children is centered at structural and functional immaturity of salivary gland which can lead to hyposalivation and low salivary flow in addition to reducing water content in the saliva and thus increasing salivary viscosity (25,26,27). preand peri-natal risk factors such as low birth weight and prematurity are presumed to shape the developing brain and predict the development of stress-related problems. in premature infants, a number of complications are considered to be associated with adrenal insufficiency and cortisol values have been examined by a number of investigators in an attempt to identify infants with relative adrenal insufficiency (28-30). cortisol is produced in response to stress and is easily measured in saliva (31). there have been relatively few studies that have examined the impact of preand peri-natal risk factors on salivary cortisol level. bettendorf et al. (32) found that healthy full-term neonates exhibited higher salivary cortisol concentrations than healthy preterm neonates. while wüst et al. (33) reported that birth weight was associated with salivary cortisol responses to psychosocial stress in adult life. low birth weight predicted higher cortisol reactivity in young adulthood. however, the development of cortisol circadian rhythm in premature infants is not necessarily retarded and that low gestational age is not critical for the timing of emergence of the hypothalamuspituitaryadrenal (hpa) axis circadian activity (34). grunau et al. (35) reported that extremely low gestational age (elga) infants show significantly higher salivary cortisol levels many months past their expected date of delivery, suggesting possible (re-setting) of basal cortisol levels, and long term (programming) of the hpa axis. on the other hand, schmidt et al. (36) concluded that elbw adults exhibited not significantly lower salivary cortisol at baseline compared with adults born at normal birth weight. cortisol is capable of affecting local, mucosal immunity and oral microbial flora, and that mucosal immune competence affects bacterial colonization and growth (37). it affects the performance of some immune system cells (38). basal salivary cortisol and cariogenic bacteria were the strongest predictors of dental caries, and from a theoretical perspective, salivary cortisol could plausibly suppress mucosal immunity against cariogenic bacteria (39). the present study was conducted among a group of kindergarten children with low birth weight aged 5 years old in comparison to control group to evaluate the following variables: the occurrence and severity of dental caries, the changes in the physicochemical characteristics of stimulated saliva and these including (salivary flow rate, salivary viscosity, salivary cortisol), in addition to determine the relation between these variables. materials and methods in the present investigation, the study group included 40 children with low birth weight aged 5 years old of both gender. they were examined in their kindergarten during the period from the third of december 2012 till the end of january 2013. the control group included 40 children with normal birth weight who possess as much similarity as possible to the study group with regard to age, gender, social structure and geographic position except in birth weight condition. both study and control groups should not have any systemic disease that could affect on the salivary analysis. the assessment and recording of caries experiences were done through j bagh college dentistry vol. 25(4), december 2013 salivary cortisol pedodontics, orthodontics and preventive dentistry128 the application of decayed (d), missing (m) and filled (f) surface index (dmfs) index for primary teeth. in this study, the decayed fraction of the index was recorded according to the lesion severity using the criteria described by mühlemann (40). the collection of the stimulated salivary samples from the children was performed under standardized conditions according to the instructions cited by tenovuo and lagerlöf (41) and farsi (42). immediately after saliva collection, salivary flow rate was measured freshly and without centrifuged (after foam had all disappeared) by dividing the volume of the collected stimulated saliva in milliliter (ml) on the collection time in minute (min) (25). salivary viscosity was determined by measuring the volume rate of flow through a tube of known dimensions. this was done by using ostwald's viscometer which is simple device for measuring the viscosity of liquid (43). in this study, salivary viscosity was measured at room temperature and before centrifuging of salivary samples (44). the viscosity of the saliva is measured according to a liquid which have a known coefficient of viscosity, and usually the distilled water is used for this purpose. the flow times of two liquids (saliva and distilled water) which have equal volumes passing through a capillary of the same viscometer are measured and the coefficient of the viscosity of the saliva is determined. the salivary samples were then taken to the laboratory for biochemical analysis and centrifuged at 3000 r.p.m. for 10 minutes. the clear supernatant was separated by micropipette and was stored at ( 20°c ) in a deep freeze and further assessment for cortizol level in saliva was done by special cortizol kit (vidas® cortisol s) using minividas technique which is multiparametric immunoassay system (45). at the end of the assay, results are automatically calculated by the instrument in relation to the calibration curve. these results were obtained in traditional unit (ng/ml). to be converted from traditional to si units, they had been converted to (nmol/l) by multiplying them by endocrinology conversion factor (2.759) (46). intra and inter calibration were performed to overcome any problem that could be faced during the research, and to ensure proper application of diagnostic criteria used in recording dental status through inter calibration. statistical analysis and processing of the data were carried out using spss version 19. after exploring the data, it had been found that they were not normally distributed. the non-parametric mann-whitney u test was utilized for the parameters of the data which were not normally distributed and in this test the median and mean rank were used to analyze and determine the differences between the study and control groups. the correlation coefficient tests between the variables were done by using pearson correlation. the confidence level was accepted at the level of less than or equal to 5%. the highly confidence level was accepted at the level of less than or equal to 1%. results the distribution of the low birth weight and their matching normal birth weight children by gender are shown in table (1). dental caries experience in primary dentition represented by dmfs and its components (ds,ms,fs) among low and normal birth weight groups are illustrated in table (2). results revealed that the mean rank of dmfs for the total sample was found to be higher among low birth weight than normal birth weight and the difference was significant (mann whitny=566.000, z=-2.280,p=0.023). the mean rank of decay fraction (ds), filling (fs) and missing (ms) surface were found to be higher among low birth weight than normal birth weight with significant difference for ds (mann whitny=586.000, z=-2.087, p=0.037) and highly significant difference for ms (mann whitny=625.000, z=-2.622, p=0.009) while for fs, the difference was not significant (p> 0.05). the grades of decay fraction among low and normal birth weight groups are represented in table (3). concerning low birth weight, the d1 fraction of severity was the highest, followed by d3, d2. while the d4 showed the least fraction of decay severity. for normal birth weight group, the d4 fraction of severity was the highest, followed by d2 and d3. while the d1 showed the least fraction of decay severity. for the total sample, data analysis showed that the mean rank of d1 was higher among low birth weight than normal birth weight with statistically significant difference (mann whitny=616.000, z=-2.193, p=0.028).however, the same picture was observed for d2, d3, and d4 with statistically non significant difference (p> 0.05). the physicochemical characteristics of the stimulated whole salivary flow rate among low and normal birth weight groups are illustrated in table (4). the mean rank of salivary flow rate was found to be lower among low birth weight than normal birth weight with no significant difference (p> 0.05). apposite finding was found concerning salivary viscosity as the mean rank was highly significantly higher among low birth weight group than normal birth weight group (mann whitny=387.500, z=-3.970, p=0.000). j bagh college dentistry vol. 25(4), december 2013 salivary cortisol pedodontics, orthodontics and preventive dentistry129 the same result was found for salivary cortisol with no significant difference (p>0.05). table (5) shows the correlation coefficient between caries experience in primary dentition represented by dmfs and ds components and salivary variables among low and normal birth weight groups. for low birth weight group, the relation between salivary flow rate and caries experience was weak and not significant in positive direction concerning dmfs while in negative direction concerning ds. the same relations were found between salivary viscosity and both dmfs and ds in positive direction while the relations between salivary cortisol and both dmfs and ds were found to be weak, and non significant in negative direction. concerning normal birth weight, the relations between salivary flow rate and both dmfs and ds were weak and non significant in positive direction. the same relations were found between salivary cortisol and both dmfs and ds while the relations between salivary viscosity and both dmfs and ds were found to be weak, and non significant in negative direction. table (6) represents the correlation coefficient between salivary cortisol and both salivary flow rate and salivary viscosity among low and normal birth weight groups. concerning low and normal birth weight groups, data analysis for the total sample showed that the relation between salivary flow rate and cortisol was found to be weak and non significant in negative direction, while the relation between salivary viscosity and cortisol was found to be weak and non significant in positive direction. discussion infants born preterm and with low birth weight are at greater risk for mortality, disability and a variety of health and developmental problems compared with infants born at term (47,48). a fetal programming hypothesis proposed that stressful events during fetal development may program the developing brain for how it handles subsequent stress (49). in terms of caries experience among the low birth weight group, the present study showed that the mean rank of dmfs and decay fraction ds were significantly higher than the normal birth weight group. this result was in agreement with the results reported by many previous studies (810,50,51), and was in disagreement with the results that concluded by others (11,12,52-55). these results might be due to neonatal malnutrition which increases the risk of poor pregnancy outcomes including low birth weight infants. the greater systemic infant malnutrition associated with low birth weight children is said to result in systemic insults to the developing primary teeth which can lead to disturbances in the mineralization resulting in hypoplasia (13,56) and thus predisposing the teeth to caries (14,57). other causes can be attributed to maternal lactation failure, so that lack of breast feeding or exclusive breast feeding for shorter duration in these children leads to undernourishment during maturation phase of teeth and this can lead to hypoplasia and enamel defects which are more susceptible areas to dental caries (58). the higher caries experience could be attributed to the lower social class of those children with low birth weight as reported by some previous studies (59,60). this can be attributed to the low family income and the degree of education in the lower social classes which can affect food selection, nutrient intake, health values, life style, oral hygiene practices, access to health care information and susceptibility to childhood infections (17,52). the lower flow rate that was found in the present study (although not significant) among low birth weight children could give another explanation for high caries experience. this can be explained by the fact that many evidences suggest that intrauterine growth restriction (iugr) leads to impaired growth and maturation of the salivary gland (structural immaturity and lack of differentiated parenchymal elements of the organ may form the basis of its secretory function’s lesion) which causes hyposalivation and low salivary flow. this is in agreement with previous study (27). although, dental decay is a multifactorial disease, the salivation’s insufficiency is believed to have harmful effect on oral health, this is also shown in the present study as data analysis showed that the correlation between the salivary flow rate and decay fraction (ds) and grades of dental caries (d1-4) were found to be inverse relations among the low birth weight children. this could be attributed to the fact that the higher the flow rate, the faster the clearance, the higher the buffer capacity and the lower dental caries (61,62). increased dental caries might be due to increased saliva viscosity as data of the current study showed high viscosity among low birth weight children. this can be explained by the fact that preterm and low birth weight children are affected by structural and functional immaturity of the salivary gland. this gives reasons for increased viscosity that may be due to reduced water content in the saliva. this finding is in correlation with other study (63) and this is also found by data of the present study that showed an j bagh college dentistry vol. 25(4), december 2013 salivary cortisol pedodontics, orthodontics and preventive dentistry130 inverse relation exists between salivary viscosity and salivary flow rate which was in agreement with other study (25). increased salivary viscosity plays a role in increasing caries incidence. among low birth weight children, data analysis of the present study revealed that the correlation of the salivary viscosity with dental caries was found to be a positive relation, which could give another explanation for high caries experience in present study as well as in previous studies (64-66) among other study groups. this may be attributed to the fact that saliva that is more viscid is less effective in clearing the mouth from food derbies, reduced bacterial co-aggregation, and played a role in increasing caries incidence (65). other causes for high caries experience could be attributed to high salivary cortisol level among low birth weight group (although not significant) and this was in agreement with previous study (33) and can be explained as the higher cortisol level may suppress the oral immunity and induce the proliferation of the cariogenic bacteria leading to increased incidence of dental caries. basal salivary cortisol secretion was positively associated with dental caries. from a theoretical perspective, salivary cortisol could suppress mucosal immunity against cariogenic bacteria. basal salivary cortisol secretion and cariogenic bacteria bore strong and independent associations with counts of dental caries (39). concerning the correlation of the salivary cortisol with flow rate, data analysis of the present study reported an inverse correlation among both low and normal birth weight groups. this is in agreement with some previous studies (67,68) while disagrees with others (69,70) among other study groups. this may be explained by the fact that as the flow rate increased, the ph increased but the protein level decreased (68) and as cortisol is a salivary protein, therefore; its level may be decreased. the correlation of the salivary cortisol with viscosity was found to be a positive relation in both low and normal birth weight children. the explanation for this can be attributed to the fact that the salivary cortisol is one of the important protein component of human saliva and increasing its value leads to increase viscosity of saliva as viscosity was correlated positively with the total protein concentration (25,71). in conclusion, dental professionals need to have comprehensive knowledge about the low birth weight status among children to assess the effects of this status with respect to oral diseases 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between unstimulated salivary flow rate and saliva composition of healthy children in taiwan. chang gung med j 2008; 31: 281-6. 63. holbrook wp, de soet jj, de graaff j. prediction of dental caries in pre-school children. caries res 1993; 27: 424-30. 64. al-awadi rn. oral health status, salivary physical properties and salivary mutans streptococci among a group of mouth breathing patients in comparison to nose breathing (comparative study). m.sc. thesis, college of dentistry, university of baghdad, 2012. 65. kaur a, kwatra ks, kamboj p. evaluation of nonmicrobial salivary caries activity parameters and salivary biochemical indicators in predicting dental caries. j indian soc pedod prev dent 2012; 30(3): 212-7. 66. ghanim am, mariño r, morgan m, bailey d, manton d. an in vivo investigation of salivary properties, enamel hypomineralisation, and carious lesion severity in a group of iraqi schoolchildren. int j paediatr dent 2013; 23(1): 2-12. 67. soderling e, pienihakkinen k, alanen ml, hietaoja m, alanen p. salivary flow rate, buffer effect, sodium, and amylase in adolescents: a longitudinal study. scand j dent res 1993; 101: 98-102. 68. wu kp, ke jy, chung cy, chen cl, hwang tl, chou my, wong am, hu cf, lee yc. relationship between unstimulated salivary flow rate and saliva composition of healthy children in taiwan. chang gung med j 2008; 31(3): 281-6. 69. humphrey sp, williamson rt. a review of saliva: normal composition, flow, and function. j prosthet dent 2001; 85: 162-9. 70. bakke m, tuxen a, thomsen ce, bardow a, alkjaer t, jensen br. salivary cortisol level, salivary flow rate, and masticatory muscle activity in response to acute mental stress: a comparison between aged and young women. gerontology 2004; 50(6): 383-92. 71. dawes c. salivary flow patterns and the health of hard and soft oral tissues. j am dent assoc 2008; 139(suppl 2):18s-24s. table 1: distribution of the low birth weight and their matching normal birth weight children according to gender low birth weight normal birth weight gender no. % no. % males 21 52.5 21 52.5 females 19 47.5 19 47.5 total 40 100 40 100 table 2: dental caries experience (dmfs) and components (ds, ms and fs) among low birth weight and normal birth weight children statistical differences normal birth weight low birth weight p-value zvalue u-test df mean rank median no. mean rank median no. 0.023 -2.280* 566 78 34.65 2.5 40 46.35 6 40 dmfs 0.037 -2.087* 586 78 35.15 2.5 40 45.85 4 40 ds 0.009 -2.622** 625 78 36.13 0 40 44.88 0 40 ms 0.096 -1.665 721 78 38.53 0 40 42.48 0 40 fs (* p<0.05 significant, ** p<0.01 highly significant) j bagh college dentistry vol. 25(4), december 2013 salivary cortisol pedodontics, orthodontics and preventive dentistry133 table 3: grades of dental caries among low birth weight and normal birth weight children statistical differences normal birth weight low birth weight p-value zvalue u-test df mean rank median no. mean rank median no. 0.028 -2.193* 616 78 35.9 0 40 45.1 0 40 d1 0.414 -0.834 715.5 78 38.39 1 40 42.61 2 40 d2 0.12 -1.555 661.5 78 37.04 0 40 43.96 0 40 d3 0.572 -0.565 763.5 78 39.59 0 40 41.41 0 40 d4 (* p<0.05 significant) table 4: salivary physicochemical characteristic among low birth weight and normal birth weight children statistical differences normal birth weight low birth weight ` p-value zvalue u-test df mean rank median no. mean rank median no. 0.532 -0.626 735 78 42.13 0.347 40 38.88 0.307 40 flow rate (ml/min) 0.000 -3.970** 387.5 78 30.19 0.012 40 50.81 0.012 40 viscosity (dyne.sec/cm2) 0.835 -0.208 780 78 40.01 5.52 40 40.99 5.52 40 cortisol (nmol/l) (** p<0.01 highly significant) table 5: correlation coefficient (r) between dmfs, ds components of dental caries and salivary flow rate (ml/min), salivary viscosity (dyne.sec/cm2), and salivary cortisol (nmol/l) among low birth weight and normal birth weight children normal birth weight low birth weight ds dmfs ds dmfs salivary variables p r p r p r p r 0.328 0.159 0.28 0.175 0.461 -0.12 0.934 0.014 flow rate 0.545 -0.099 0.501 -0.11 0.741 0.054 0.427 0.129 viscosity 0.863 0.028 0.955 0.009 0.098 -0.265 0.081 -0.279 cortisol table 6: correlation coefficient (r) between salivary cortisol (nmol/l) and flow rate (ml/min) and viscosity (dyne.sec/cm2) among low birth weight and normal birth weight children salivary cortisol normal birth weight low birth weight p r p r 0.273 -0.178 0.725 -0.057 flow rate 0.152 0.231 0.365 0.147 viscosity j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 83 computer assisted immunohistochemical score prediction via simplified image acquisition technique salam n. jawad, b.d.s., m.sc. (1) bashar h. abdullah, b.d.s., m.sc., phd. (2) abstract background: techniques of image analysis have been used extensively to minimize interobserver variation of immunohistochemical scoring, yet; image acquisition procedures are often demanding, expensive and laborious. this study aims to assess the validity of image analysis to predict human observer’s score with a simplified image acquisition technique. materials and methods: formalin fixedparaffin embedded tissue sections for ameloblastomas and basal cell carcinomas were immunohistochemically stained with monoclonal antibodies to mmp-2 and mmp-9. the extent of antibody positivity was quantified using imagej® based application on low power photomicrographs obtained with a conventional camera. results of the software were employed to predict human visual scoring results with stepwise multiple regression analysis. results: the overall prediction of epithelial score depicted as r square value was 0.26 (p<0.001) which was obviously higher than that of stromal score (0.10; p<0.01). epithelial and stromal mmp-2 score prediction was generally higher than that of mmp-9. collectively, ameloblastomas had a more efficient score prediction compared to basal cell carcinomas. conclusion: there is a considerable variability in the prediction capacity of the technique with respect to different antibodies, different tumors and cellular versus stromal score. keywords: immunohistochemistry, image analysis (j bagh coll dentistry 2017; 29(1):83-88) introduction quantification of staining results is a crucial step within the methodology of thousands of immunohistochemical study designs; where attempts are always made to reach objective, concise and reproducible results. semiquantitative scoring is the most common approach that involves one or more trained observer to convert what he/she sees into numeric or logical values(1). advancements in computer hardware capabilities through the last few decades facilitated the use of image processing programs to collect data from captured images(1, 2, 3). one of the commonly employed multiplatform programs is “imagej”; which is an open source software developed by nhs in 1997 and was involved in many microscopic research designs. the software had many built in or optional “add on” functions in the form of combined analytic steps merged into single click; they are called “plugins” and “macros” (4). varghese et al. (2014) developed an imagej® compatible macro that would separate and quantify diaminobenzidine(dab) and hematoxylin colors according to pixel intensity within images of immunohistochemically stained (1) phd. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. tissue sections(5). this study aims to evaluate the validity of this specific macro function with respect to human observer’s percentage scoring of two epithelial tumors (ameloblastoma & basal cell carcinoma) stained with two monoclonal antibodies (mmp-2, mmp-9) with a simplified image acquisition technique. materials and methods formalin fixed, paraffin embedded tissue specimens of ameloblastomas (ab) and basal cell carcinoma (bcc) were retrieved from the archives of oral pathology laboratory at the college of dentistry/baghdad university and medical city laboratories. five um thick sections were mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies for mmp-2 (ab: n=32; bcc: n=26; ab2462,1:200) and mmp-9 (ab: n=33; bcc: n=29; ab76003,1:100) using expose mouse and rabbit specific hrp/dab detection ihc kit (ab80436) . stained tissue sections were evaluated by two observers with at least 5 high power fields (x40) for cellular and stromal positivity as a percentage of positive cells to the total high power field (hpf) then, a mean of the fields was calculated. visual scoring values of 2 experienced observers were correlated by pearson correlation coefficient, the values were accepted when r between the observers’ readings exceeds (0.80), j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 84 otherwise; the sections were re-evaluated to reach a consensus. at least, 3 photomicrographs for the dab and hematoxylin stained tissue sections were captured with a 10x objective using an ordinary digital camera fixed to the eyepiece (samsung-gtn7100). with imagej’s region of interest (roi) selection options; multiple cellular areas were surrounded with selection polygons followed by ihc macro application (fig. 1). for any given case, a mean value of each ihc profiler parameters result was calculated (pixel count, percentage of high positive, percentage of positive, percentage of low positive, percentage of negative). the same preceding steps (selection and macro application) were applied to stromal areas only. stepwise and multiple regression analysis for human score prediction was employed for statistical analysis using spss.22 software, adopting the imagej’s output data as independent variables (predictors). . results tumor epithelial and stromal expression was found in tissue sections of ameloblastoma and basal cell carcinoma for mmp-2 and mmp-9 to different extents. combined visual and computer assisted immunohistochmical scoring characteristics of the two antibodies are summarized in tables 1 and 2. the predictive ability of the software algorithm, reflected by the (r square) varied across different tumors, antibodies and the evaluated compartments (epithelial or stromal). tumor cellular evaluation with the software showed the highest r square values for the multiple stepwise regression in which the percentage of negative contribution (n%) and the pixel count (pc) were the most common independent variables that predict the human visual score. on the other hand, evidently lower r square values were found upon applying the software to the stromal elements, with more versatile predicting variables between different antibodies and different tumors. figure 1: (a) applying multiple polygon selection to regions of interest (roi) of an image. (b) choosing “ihc profiler macro” from the imagej’s plugins drop down menu. (c) software’s results window a j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 85 discussion reproducibility is a major issue in interpretation of immunohistochemical results quantification, both intra-observer and interobserver agreements are a pre-requisite for any research to be valid (6). several attempts have been made to neutralize human observer’s possible bias through image based computer assisted analytic approaches with variable success (1, 3, 7, 8). a research group at the molecular functional imaging laboratory in india developed a macro (a single computer instruction that expands automatically into a set of instructions to perform a particular task) named “ihc profiler” ; compatible with imagej®, the macro would separate images of dab stained immunohistochemical sections to 3 fractions of varied brown positivity and one more for blue negativity depending on individual pixel color values and display the results as a percentage contribution of high positive, positive, low positive and negative(5). in this study; the macro was applied to low power micrographs of immunohistochemically stained tissue sections of ab and bcc and the resulting output in addition to the number of pixels analyzed were plotted to predict the corresponding human observer’s results according to standard scoring methods. in order to be more time effective and simple for the non-experienced observer, this study had major design differences from the original work by varghese et al. (5); the images were acquired with a conventional digital camera rather than a slide scanner in an attempt for method simplification to be accessible for any low budget laboratory, moreover; the study used a low magnification power for photomicrographs for a generalized view that would minimize the number of photographs needed for analysis. ameloblastoma and basal cell carcinoma were selected in this study as prototypical examples for benign and malignant epithelial tumors that bear a morphological mimicry. stepwise regression analysis is a special variant of multiple regression that enters the independent variables (macro results in this study) in the regression model one variable at a time with omission of the effect of other variables to specify the most significant variables that predict the value of the dependent variable (human scoring in this study)(9). at first glance, the predictive ability of ihc profiler in the cellular compartment was mostly associated with (n) variable which actually represents all the three macro variables (h, p and l) subtracted from 100%, however; pixel count had an effect in predicting ab human results more than bcc which is most probably resulting from the relatively less cellular islands selected for ab as compared to the bcc that leads to a lower pixel count. mmp-2 showed relatively high predictive results where the model explained a minimum of 40% of human scoring variability, a slightly higher r square value was noted in bcc in contrast to mmp-9 predictions which had notably lower values overall and a higher r square for ab. regarding stromal expression, though generally less than cellular expression; r square values showed more predictive power in mmp-2 than mmp-9. again, predictive values of mmp-2 human expression were higher in ab with conversely higher values for mmp-9 in bcc those results suggest that the model is definitely better predicting epithelial mmp-2 scores than mmp-9 regardless of the tumor type, moreover; it was more predictive concerning mmp-9 in ab and mmp-2 in bcc. however, overall results of the study approach indicated marked variability of the software’s prediction capacity with respect to different antibodies and tumors. keeping a minimally laborious and complicated image acquisition technique probably mandates the employment of more sophisticated computer analytic procedures to approach human visual perception. references: 1heindl a, nawaz s, yuan y. mapping spatial heterogeneity in the tumor microenvironment: a new era for digital pathology. lab invest 2015; 95: 377384. 2kaczmarek e, górna a, majewski p. techniques of image analysis for quantitative immunohistochemistry. roczakad med bialymst 2004; 49: 155-158. 3matos lld, stabenow e, tavares mr, ferraz ar, capelozzi vl, pinhal ms. immunohistochemistry quantification by a digital computer-assisted method compared to semiquantitative analysis. clinics 2006; 61: 417-424. 4schneider ca, rasband ws, eliceiri kw. nih image to imagej: 25 years of image analysis. nat methods 2012; 9: 671-675. 5varghese f, bukhari ab, malhotra r, de a. ihc profiler: an open source plugin for the quantitative evaluation and automated scoring of immunohistochemistry images of human tissue samples. plos one 2014; 9: e96801. 6zlobec i, steele r, michel rp, compton cc,lugli a, jass jr. scoring of p53, vegf, bcl-2 and apaf-1 immunohistochemistry and interobserver reliability in colorectal cancer. mod pathol 2006; 19: 1236-1242. 7lehr ha, mankoff da, corwin d, santeusanio g, gown am. application of photoshop-based image analysis to quantification of hormone receptor expression in breast cancer. j histochemcytochem1997; 45: 1559-1565. j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 86 8laurinavicius a,laurinaviciene a, ostapenko v, dasevicius d, jarmalaite s, lazutkaj. immunohistochemistry profiles of breast ductal carcinoma: factor analysis of digital image analysis data. diagnpathol 2012; 7: 27. 9dejmek a,hjerpe a. immunohistochemical reactivity in mesothelioma and adenocarcinoma: a stepwise logistic regression analysis. apmis 1994; 102: 255264. الخالصة في التفسير تباين غرض تجنب الاستعملت تقنيات التحليل الصوري باستخدام الكومبيوتر بشكل مسهب في عدة دراسات سابقة ل الخلفية: نتائج الصبغات المناعية عند تعدد الفاحصين, مع ذلك؛ امتازت الطرق المختلفة بكونها تتطلب عمليات معقدة ومكلفة اللتقاط البصري ل عدة للتحليل. تهدف هذة الدراسة لفحص امكانية توقع نتائج الفحص البصري بناءا على التحليل الصوري لصور شرائح الصور الم مجهرية ملتقطة بطريقة مبسطة. ومي الَ َوَرم لل رة بشمع البارافين: تضمنت الدراسة عينات مثبتة بالفورمالين ومطمومواد وطرق العمل )اميلوبالستوما( ومينائي ال رم بطريقة التصبيغ الكيميائي mmp-9و mmp-2سرطان الخلية القاعدية صبغت شرائحها باجسام مضادة احادية النسل موجهة الى اجريت والتي ®imagejالمناعي. تم تقييم نتائج االصطباغ المناعي بالطرق البصرية المعتادة و بوساطة التحليل الصوري لبرنامج ملتقطة باستخدام كاميرا اعتيادية من ثم قورنت نتائج التحليل الصوري مع نتائج الفحص البصري على صور مجهرية واطئة التكبير المجهري عن طريق احتساب صحة توقع التحليل الصوري باسلوب االنحدار الخطي المتسلسل. r)2 ;0.10=مقارنة باالجزاء السدوية منهاr =0.26 (p<0.001)2 ظهرت نتائج اعلى للتوقع في اجزاء االورام الظهارية النتائج: p<0.01) وبشكل عام؛ كانت نتائج التوقع لالجزاء الظهارية والسدوية لمؤشر ,mmp-2 اعلى من نتائج مؤشرmmp-9 كذلك؛ , مقارنة بسرطان الخلية القاعدية.)االميلوبالستوما( ورم قيمتها اعلى فيكانت داخل تعددةوالمناطق الم المختلفة المؤشرات واالورام بين بشكل ملموس ليلي للطريقة المستخدمةنتائج التوقع التح تتبايناالستتنتاجات: االورام. j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 87 j bagh college dentistry vol. 29(1), march 2017 computer assisted oral diagnosis 88 24saif f.docx j bagh college dentistry vol. 28(3), september 2016 comparison of shear pedodontics, orthodontics and preventive dentistry 142 comparison of shear bond strength of three different brackets bonded on zirconium surfaces (in vitro study) saif mauwafak, b.d.s. (1) dhiaa jaafar al-dabagh, b.d.s, m.sc. (2) abstract background: with the increased in the demands of adult orthodontics, the challenge of direct bonding to nonenamel surface (zirconium) had been increased. the present study was carried out to compare the shear bond strength of three different brackets (stainless steel, sapphire and composite) bonded to zirconium surface and study the mode of bond failure. materials and methods: the sample was comprised of 30 models (8mm *6mm*1.5mm) of full contour zirconium veneers. they were divided into three groups according to the brackets type; all samples were treated first by sandblast with aluminum oxide particle 50 µm then coated by z-prime plus primer. a central incisor bracket of each group was bonded to the prepared zirconium surface with light cure adhesive resin (transbond tm xt, 3m unitek, usa). shear bond strength was measured by using tinius olsen universal testing machine at crosshead speed of 0.5\min. after debonding, each bracket and zirconium surface were examined using magnifying lens and adhesive remnant index was recorded. the difference in shear bond strength between main groups was analyzed by using anova at p≤0.05. results: the results revealed high significant difference among all tested groups and the highest value was for sapphire brackets (7.49±1.45 mpa) of all groups followed by stainless steel brackets (6.46±1.43mpa) and composite brackets had the least value (4.35±0.72). non-significant difference in the site of bond failure among all groups of brackets and zirconium-adhesive interface failure (score iii) was the predominant. conclusion: the new zirconium prime plus primer can be successfully used in bonding stainless steel and sapphire brackets to zirconium surface. keywords: zirconium, zirconium prime plus primer, shear strength. (j bagh coll dentistry 2016; 28(3):142-148). introduction zirconia is polycrystalline ceramic and it is silica free, acid-resistant material. it does not incorporate amorphous silica glass (such as, leucite-reinforced ceramics, feld spathic porcelain, and lithium disilicate ceramics); therefore, the traditional surface treatments of ceramic such as hydrofluoric acid etching followed by silane application are ineffective (1,2). zirconium materials have been used in clinical dentistry for many years with great success. making adhesion to non-silica-based oxide ceramic materials like zirconia, metal and alumina was the challenge that limited their use (1,3).there are dilemmas in bonding of zirconium; the wellknown methods of mechanical and chemical bonding that used on glass-ceramics cannot be applicable for use with zirconia, due to important fact which is the absence of silica in the microstructure of zirconia and this ignores the viability of roughening the etching material which is an essential method for mechanical bonding as well as restricted the use of silanes for forming surfaces hydroxyls and developing the essential chemical bond (1). the approaches suggested improving bond strength to zirconium surfaces can be grouped into three broad categories, namely mechanical, chemical, or combination. (1) m.sc. student department of orthodontics. college of dentistry, university of baghdad. (2) professor department of orthodontics. college of dentistry, university of baghdad. the purpose of mechanical alteration of the zirconium surface is to remove the glaze and roughen the surface to provide sufficient mechanical retention for the adhesive, allowing for the successful placement and retention of the orthodontic bracket. this alteration of the zirconium surface has been achieved by surface abrasion or roughening (grinding, air borne particle abrasion using al2o5 (50-110) µm, rotary abrasion by using diamond burs) creates adhesion only through micro-mechanical retention (4). the glaze of zirconium is translucent, lowfusing, porcelain which may be applied to the surface as the final stage in the firing cycle and has the effect of filling surface defects (5). mechanical adhesion alone is not enough for providing the optimal bond strength so; they promote the chemical adhesion in zirconia bonding. however, roughness of the surface is a key factor for adhesion to zirconia and the elimination of these particles abrasion for surface treatment could result in great reduction in bond strength (6,7). chemical bonding to zirconium can be done by adhesive functional monomers, which are supposed to have the capability to form chemical hydrogen bonds with metal oxides at the resin/zirconia interface and improving the wettability (8). phosphate monomers are proven to be effective in bonding to non-silica-based polycrystalline materials of zirconia, metal and j bagh college dentistry vol. 28(3), september 2016 comparison of shear pedodontics, orthodontics and preventive dentistry 143 alumina (9). numerous studies have shown that phosphate /phosphonate monomers are very effective in improving zirconia bonding. in theory, phosphate monomers form chemical bonds with the zirconia, alumina, and metal oxide surfaces (10). z-prime plus is a phosphate monomer and it contains a propriety formula of concentrated methacryloxydecyl dihydrogen phosphate (mdp) and carboxylic monomers formulated specific to zirconia, alumina, and metal. the versatility of these primers is a compelling feature for use on many different indirect substrates (11). recently, the use of zirconium in cosmetic dentistry was expanded obviously coincided with a new trend of adult orthodontics; therefore it is very important nowadays to find an accepted method and material of bonding orthodontic appliances effectively to zirconium surface with subsequent removal of these appliances without any damage to these restorations. there was no any previous study in iraq regarding this important subject so; it is intended to implement the current study to provide a base line data regarding that. materials and methods sample thirty zirconium veneers of upper right central incisor of identical size & shape of the same company (zolid, amann girrbach gmbh) would be made by using cad/cam machine (ceramill motion2). each surface had been examined by using a 10x magnifying eye lens to see if there is any manufacturer defect including cracks, roughness or irregularities on the labial surface of the veneer (12). the zirconium veneers would be divided according to the bonded brackets into three groups: 1) ten stainless steel brackets would be bonded on the labial surface of ten zirconium veneers (orthotechnology, u.s.a), surface area 9.6 mm2. 2) ten composite brackets would be bonded on the labial surface of ten zirconium veneers (orthotechnology, u.s.a), surface area 21mm2. 3) ten sapphire brackets would be bonded on the labial surface of ten zirconium veneers (orthotechnology, u.s.a), surface area 12 mm2. construction of zirconium veneers well prepared tooth of upper right central incisor had been done by professional dentist to form zirconium veneer for this tooth, after that the prepared tooth had been scanned by the cad/cam machine to design the veneer using specific software by well-trained technician. the same model could be duplicated by definite software to form thirty veneers of identical size and shape. the dimensions of these veneers were 8mm in length, 6mm in width and 1.5 mm in depth. since these zirconium veneers were partially sintered, sintering at 1450◦c for 4 hr. was necessary to achieve the required hardness. then, the outer surface of each veneers would be covered with glaze and stain liquid (ips e.max ceram glaze and stain all round, ivoclar vivadent) and fired at 930◦c. construction of the acrylic blocks a square of stainless steel tube would be cut into slices of identical cubes. the dimensions of these cubes would be 2.5cm in width and 1cm in depth, after that, each cube would be drilled in both sides in order to remove the excess of the acrylic that had been passed through the holes. then cold cure acrylic would be mixed according to manufacture instruction and poured into each cube for 1 cm height. each zirconium veneer was placed in the middle of each acrylic cube. then, glass slide was fitted against the veneer and pressed by the vertical arm of the surveyor by applying 100 gm. on the top of this arm. finally, the excess of acrylic that had been passed through the holes could be removed by sharp scaler. all samples were hydrated in deionized distilled water at 37˚c in incubator for 1-week before bonding to simulate the oral condition (13). the labial surface of all veneers were polished using a non-fluoridated pumice (for standardization one rubber cap used for each subgroup) attached to a low speed hand piece for 10 seconds (14,15), then each surface was washed with water spray for 10 seconds, and dried with oil-free air for 10 seconds (16-18). a distance of 1cm that used as standardization to hold the air water syringe away from veneer surface kept fixed throughout this study (19, 20). bonding procedures the zirconium surfaces would be sandblasted by 50μm aluminum oxide powder for 5 sec. at 10 mm distance with 2.5 bars (21). the bonding could be done by applying a thin layer of primer on the outer surface of zirconium veneer and on the mesh of the brackets by using a disposable brush and wait for 10 sec. according to the manufacture instruction, and then suitable amount of light cure composite would be applied on the bracket base according to the manufacturer instructions, which would then position in the j bagh college dentistry vol. 28(3), september 2016 comparison of shear pedodontics, orthodontics and preventive dentistry 144 middle third of the outer surface and parallel to the long axis of the veneer using a clamping tweezers. then, a constant load would be applied by vertical arm of the surveyor by weight fixation of 200 gm. on the top of this arm, which would be placed on the bracket at 90 ° for 10 sec. to ensure that each bracket would seat under equal force (21,22). any excess bonding material could be carefully removed from around the bracket base with a sharp hand scaler without disturbing the seated bracket (23-25), then the brackets would be cured for 40 sec (20 sec on the mesial and 20 sec. on the distal of the brackets (26) by using led light cure (high intensity 1500mw/cm2, 6mm depth of cure, sdi, china), at a distance of 5 mm(27) (for standardization we fixed a ruler at the tip of the light probe) and an angle of 45º to the proximal surface of the bracket (28). after the completion of the bonding procedure, the specimens would be allowed to bench cure for 30 minutes, then would be immersed in deionized distilled water and could be stored in the incubator at 37º c for 24 hours (29). shear bond strength test shear test was accomplished using tinius olsen universal testing machine, with loading cell 50 kilogram & a crosshead speed of 0.5 mm/min (25, 30). each sample was seated in the mounting metal vice and placed on the base of the testing machine (which was parallel with the horizontal plane). the chisel end rod was fitted inside the upper arm of the testing machine with its chisel end downward parallel to the bonded zirconium labial surface to apply a force in an gingivoincisal direction of the bracket that produce a shear force at the bracket base/ zirconium surface interface, until debonding occurs. when the bracket was debonded from the zirconium labial surface by the force applied from the testing machine, the ultimate magnitude of the reading was taken; this force was measured in kilograms and converted into newtons according to the following equation: force (n) = load (kg) x ground acceleration (9.8 m/sec.). then the force was divided by bracket base surface area to get the strength value in mega pascal (mpa) units. each debonded bracket was kept with its corresponding zirconium veneer to estimate the adhesive remnant index. estimation of the adhesive remnant index the debonded bracket and zirconium surface of each tooth were inspected using a 10x magnifying lens to determine the predominant site of bond failure (24,31). the site of bond failure is scored according to wang et al. index (32) that had been modified to the zirconium surfaces, as follow: score i: failure between the bracket base and adhesive. score ii: cohesive failure within the adhesive itself, with some of the adhesive remained on the zirconium surface and some remained on the bracket base. score iii: failure between adhesive and zirconium surface. score iv: zirconium detachment. statistical analyses data were collected and analyzed using spss (statistical package of social science) software version 15 for windows xp chicago, usa. in this study the following statistics were used: a. descriptive statistics: including mean, standard deviation, minimum, maximum, percentage, frequency and statistical tables. b. inferential statistics: including; 1. one way analysis of variance (anova): to test any statistically significant difference among the tested groups. 2. least significant difference (lsd): to test any statistically significant differences between each 2 groups when anova showed a statistical significant difference. 3. chi-square: to test the non-parametric data for adhesive remnant index. *p level of 0.05 was accepted as statistically significant at the following levels: p > 0.05 ns non significant 0.05 > p > 0.01 s significant p < 0.01 hs highly significant results the descriptive statistics (means, standard deviations, minimum and maximum values) of the shear bond strength of each group were presented in table (1). it was clearly obvious that sapphire brackets group had the highest mean value of shear bond strength (7.49±1.45 mpa) of all groups followed by stainless steel brackets group (6.46±1.43mpa) while composite brackets group had the least value (4.35±0.72 mpa). anova showed that there was statistically highly significant difference (p ≤ 0.01) among the mean values of the shear bond strength of the three types of brackets. lsd test showed that, there was non-significant difference between stainless steel and sapphire brackets groups (pvalue > 0.05) but there was highly significant j bagh college dentistry vol. 28(3), september 2016 comparison of shear pedodontics, orthodontics and preventive dentistry 145 difference between stainless steel and composite brackets and between sapphire and composite brackets groups (p ≤ 0.01). table 1: descriptive statistics of the shear bond strength (mpa) in different groups. adhesive remnant index “ari” the sites of bond failure of all tested groups were shown in table (2). the highest percentage of bond failure was seen at zirconium-surface interface (score iii) and associated with the use of both sapphire (90%) and stainless steel (90%) bracket groups while the composite bracket group was the least (60%).regarding (score i) and (score iv) there were no any value registered among all three groups. however for the cohesive failure (score ii) it was less in sapphire (10%) and stainless steel (10%) bracket groups than composite bracket group (40%). statistically, chi-square test showed non-significant difference in the site of bond failure among all groups of brackets. yate's correction test was used to compare the site of bond failure between each groups and showed non-significant difference. table2: frequency and distribution of the ari scores in different groups. (x2=3.750, d.f. =2, p-value=0.169 ns). discussion with the exception of composite bracket, sapphire and stainless steel brackets had shear bond strength exceed or within the normal limits that suggested by reynolds (33) which is (6-8) mpa; to be able to withstand masticatory and orthodontic forces in different clinical conditions. the highest shear bond strength value was demonstrated in sapphire brackets on zirconium surfaces and this could be attributed to: (1) the presence of zirconia particles coating the bracket base that creates millions of undercuts (34), those secure the bracket in place, due to the micro mechanical retention means, and this revealed difference in shear bond strength when compared to other bracket types. in more practical words, it was greater by 1.16 times than stainless steel brackets and 1.72 times than composite brackets. (2)the translucency of sapphire brackets gave them a better chance for a more complete polymerization with light curing as compared to other bracket types. this gives the operator more confidence to use sapphire brackets keeping in mind that it has a lower possibility of failure as compared to other bracket types (35-37). (3) sapphire brackets are single-crystalline brackets so, they are hard and offer great strength that prevents or reduces the peeling effects that may occur during brackets debonding thus gave them high sbs values (37). (4)the fine mesh of sapphire brackets provides a good mechanical interlock into which the resin adhesive with low viscosity can penetrate and engage the retentive mesh and fill the undercuts with good air evacuation and without air entrapment (38). stainless-steel brackets arranged secondly regarding sbs value on zirconium surface and had good mean of shear bond strength 6.46 mpa and this could be due to: (1)the type of retention means on the base of the bracket which equipped with (80 gauge foil mesh bonding base) so, the composite resin adhesive can penetrate easily between these projections and fill the undercuts and provide a mechanical interlock and prevent air entrapment as the air can escape easily from the peripheries of the base of the bracket and there would be a good retention of the adhesive into the bracket base (38,39). (2)the compound contour of bracket base provide superior fit and greater contact surface area for improved retention which provide a good seating and adaptation to the surface of the tooth which result in a thin layer of adhesive between the bonded bracket base and the tooth surface and this could increase the bond strength (40). however, there was no significant difference in shear bond strength between stainless steel and sapphire brackets in lsd test but there was little difference in mean value of bond strength between them which could be due to the dimness color of steel brackets as compared with translucency of sapphire brackets and thus would affect the intensity of light and the polymerization of the adhesive (35, 36). on the other hand composite brackets had the lowest shear bond groups n mean s.d. min. max. ss 10 6.46 1.43 4.9 9 sapphire 10 7.49 1.45 5.83 10.80 composite 10 4.35 0.72 3 5.4 groups ari scores total i ii iii iv stainless steel no 0 1 9 0 10 % 0 10 90 0 100 sapphire no 0 1 9 0 10 % 0 10 90 0 100 composite no 0 4 6 0 10 % 0 40 60 0 100 total no 0 6 24 0 30 % 0 20 80 0 100 j bagh college dentistry vol. 28(3), september 2016 comparison of shear pedodontics, orthodontics and preventive dentistry 146 strength. its shear bond strength had a significant difference when compared to stainless steel and sapphire brackets and this could be attributed to: (1)the difference in surface area of the brackets (composite bracket 21 mm2, sapphire bracket 12 mm2, stainless steel brackets 9.6 mm2) though, enlarging the surface area of brackets increase the load carrying capacity, that means there is an inverse relationship between bond strength and bonded surface area, the smaller the surface area, the greater the bond strength(41). (2)the larger the size of the examined specimen (composite bracket) leading to presence of a greater number of defects and vice versa, therefore when the specimen is loaded, stress concentration will be expected at the defects and initiates crack formation (42). (3)bracket base morphology could influence the bond strength of the bracket resin interface by determining the geometry (depth, size, and distribution) of the resin tags and stress distribution within the cement bracket interface. moreover, the penetration of the light and polymerization of light activated materials could be influenced by base morphology. mechanically retained composite bracket that has base design characterized by undercut channels open horizontally at the medial and distal extremities on the surface of the base (34). therefore, this result could be due to different base design which lead to different mechanical interlock between the adhesive and bracket base and could influence the light penetration and polymerization (43). (4)the lowest shear bond strength of composite brackets may be due to the fact that the retentive groove bracket base will form an edge angle of 90 degree this leading to high localized stress concentration area around the sharp edge, and this may lead to brittle failure of the adhesive (44). concerning the adhesive remnant index scores which gave the indication about the type of bond failure for each group, it appeared that, there was no significant difference in ari among all groups. the occurrence of ari score (iii)which indicate failure at adhesive-zirconium interface were the predominant and represented 80% (24 specimens) of all tested samples, and the highest percentage occurred both in stainless steel and sapphire brackets groups (90%) while the least percentage occurred in composite bracket (60%) and this might be due to: (1)the bond failure occurs usually at the area of least resistance which means that the bond strength between the adhesive–bracket interface and the cohesive bond strength of the adhesive itself were stronger than the bond strength between the adhesive and zirconium. this could be attributed to the hardness glossy surface of zirconia, so the mechanical retention might not be sufficient enough. (2)air abrasion of zirconia, with alumina or other particles produces lower bond strength compared to other surfaces like enamel and porcelain therefore surface scratching by these particles might be not sufficient enough to produce optimal mechanical retention between the adhesive and zirconium surface (45). (3)adhesive failure at the zirconium surface might be the result of reduced depth of adhesive penetration because the resin tags were thin, and less uniform, which was conductive to weaker bond, hence less adhesive would remain on the tooth at the time of debonding. furthermore, bracket failure typically occurs at the weakest link in the adhesive junction and the weakest link appeared to be at the surface/adhesive interface (46). the ari score (ii) indicate cohesive failure within the adhesive itself, with some of the adhesive remained on the zirconium surface and some remained on the bracket base and occurred in (20%) (6 specimens) of all tested samples collectively. on other hand the occurrence of score (ii) in a low percentage specially in sapphire and stainless steel samples (10% for each) and this could be negligible while in composite bracket score (ii) occurred in a higher percentage (40%) and this could be due to the presence of three dove tail in the bracket base that may act as a stress concentration area since, the adhesive penetration in these grooves produced weaker link than that between bracket/adhesive interface or than that between surface/adhesive interface. none of the tested samples showed score (i) which indicates failure that usually occurred between brackets and adhesive, this might be due to high mechanical interlock provided with each bracket base without any weak point between bracket-adhesive links. the sapphire bonding base is coated with powder of zirconium that create millions of undercuts which mechanically lock with the bracket adhesive, while stainless steel bracket is equipped with (80 gauge foil mesh bonding base) and composite bracket has three dove tail grooves (34). also none of the tested samples showed score (iv) which usually indicates surface detachment, this may attributed to excellent strength of the zirconia surface which could reach to (1000) mpa in addition to that, most of the values of the shear bond strength were within or below the normal range (6-8) mpa of safe debonding as suggested by reynolds (33). j bagh college dentistry vol. 28(3), september 2016 comparison of shear pedodontics, orthodontics and preventive dentistry 147 the conclusions that could be drawn from this study were: 1. bonding with z-prime plus primer provides optimum value of shear bond strength for sapphire and stainless steel brackets, while regarding the composite bracket the shear bond strength was insufficient. 2. adhesive-zirconium interface failure (score iii) was the predominant mode of bond failure in all groups which is considered as the most preferable one and none of the samples showed detachment between the composite and the bracket(score i) or fractures within the zirconium itself during debonding (score iv). 3. the site of bond failure is influenced not only by the value of the shear bond strength, but also by the design of the retention means on the attachment base of the bracket. references 1. blatz mb, sadan a, kern m. resin ceramic bonding: a review of the literature. j prosthet dent 2003; 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98(3): 214-21. 45. obradović-djuričić k, medic v, dodic s, gavrilov d, antonijevic d, zrilic m. dilemmas in zirconia bonding. srp arh celok lek 2013; 141(5-6): 395-401. 46. al-khatib ar. consequences of employment selfetching primer adhesive in orthodontic practice. alrafidain dent j 2004; 4(2): 95-103. j bagh college dentistry vol. 30(3), september 2018 salivary matrix 48 salivary matrix metalloproteinase-8 (mmp-8) in relation to periodontal health status among a group of hypertensive patients eman zuhair almudaris, b.d s.., m.sc. (1) nadia aftan alrawi, b.d.s., m.sc., ph.d. (2) abstract background: hypertension is probably the most important public health problem around the world. people with periodontal disease may be at greater risk of hypertension. the inflammatory effects of periodontal disease help to promote endothelial dysfunction in arteries which may lead to changes in blood pressure. salivary mmp-8 has been associated with both periodontal disease and prevalent hypertension. aim of study: this study was conducted to measure salivary matrix metalloproteinase 8, in relation to periodontal health condition among a group of patients with hypertension in comparison with control group. materials and methods: ninety subjects, aged 45-50 years old were included in this study, seeking treatment for chest pain in ibn-albaytar center for cardiac surgical treatments in baghdad, iraq. the subjects were divided into study group (45 patient) who were diagnosed to be a hypertensive patient, and a control group (45 subject), with no hypertension. plaque status was evaluated according to the silness and loe, probing pocket depth and clinical attachment level. unstimulated saliva was collected from all subjects to analyses mmp-8. result: a high mean value of plaque index, clinical attachment level and probing pocket depth for the study group than the control group with statistically no significant difference. in addition to that, a significant positive correlation between the plaque index and the clinical attachment level among both groups. salivary mmp-8 level showed a higher level in the study group than in the control group, with statistically significant difference between groups, and a significant positive correlation was detected between salivary mmp-8 with plaque index, among study group, conclusions: higher percentage of periodontal diseases was found among patients with blood hypertension. in addition, high level of salivary mmp-8 is potentially associated with periodontal status of the study group. key words: salivary matrix metalloproteinase (mmp-8), probing pocket depth, blood hypertension. (j bagh coll dentistry 2018; 30(3): 48-53) introduction hypertension (ht), also known as high blood pressure (hbp), are a long term medical and clinical conditions in which the blood pressure in the arteries is persistently elevated(1). high blood pressure usually does not cause symptoms (2). long term high blood pressure is a major risk factor for coronary artery disease, stroke, heart failure, peripheral vascular disease, vision loss, and chronic kidney disease(3,4). high blood pressure affects between 16 and 37% of the population globally (5). data from 2011 to 2014 demonstrated that 46 percent of adults 18 years and older in the united states had hypertension (6). dentists have a rare opportunity to detect the cases of hypertension. it is a professional responsibility of dental clinician to inform the patient of their hypertensive state and to offer medical advice, including appropriate referrals. antihypertensive drugs can often cause sideeffects, such as xerostomia, gingival overgrowth, salivary gland swelling or pain, lichenoid drug reactions, taste sense alteration (7). however, dental disease has often oral manifestation of acute, chronic, and systemic disease. afflictions such as heart disease, diabetes, stroke, hypertension, multiple sclerosis, and hiv/aids often can be discovered during a routine visit to the dentist (8). periodontitis is one of the most chronic oral infectious diseases. the mouth is an ideal breeding area for bacteria and those affected by periodontal disease are at increased risk, for potentially fatal bacteria entering the bloodstream via infected oral tissue. those suffering from periodontitis are highly susceptible to sever and major health issues such as premature births and low birth-weight babies, anorexia, vascular and heart disease (8,9). people with periodontal disease may be at greater risk of heart attack or stroke. recent studies have shown that the inflammatory effects of periodontal disease help to promote blood clot formation in arteries (10). several inflammatory mediators are present, and can be reproducibly measured in saliva (11). salivary mmp-8 has been associated with prevalent hypertension and coronary artery disease. in addition, salivary levels of mmp-8 are increased in acute coronary syndromes (12). salivary levels of potential mediators of atherosclerosis could be used as biomarkers for subclinical cardiovascular disease. salivary measures may not only represent an easy to use, (1) ministry of health, baghdad, iraq (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad https://en.wikipedia.org/wiki/chronic_(medicine) https://en.wikipedia.org/wiki/disease https://en.wikipedia.org/wiki/disease https://en.wikipedia.org/wiki/blood_pressure https://en.wikipedia.org/wiki/blood_pressure https://en.wikipedia.org/wiki/artery https://en.wikipedia.org/wiki/coronary_artery_disease https://en.wikipedia.org/wiki/coronary_artery_disease https://en.wikipedia.org/wiki/stroke https://en.wikipedia.org/wiki/heart_failure https://en.wikipedia.org/wiki/peripheral_vascular_disease https://en.wikipedia.org/wiki/peripheral_vascular_disease https://en.wikipedia.org/wiki/vision_loss https://en.wikipedia.org/wiki/chronic_kidney_disease https://en.wikipedia.org/wiki/chronic_kidney_disease j bagh college dentistry vol. 30(3), september 2018 salivary matrix 49 noninvasive test for cardiovascular risk, but could potentially also expand the possibility to assess novel biomarkers, whose systemic levels may be of questionable value (13). since periodontitis is a chronic inflammatory infection, the suggestion of periodontitis as a risk factor for hypertension has begun lately. nowadays, there is more evidences supports periodontal disease as an independent risk factor for cardiovascular diseases (14). the reninangiotensin-aldosterone system (raas) is a coordinated hormonal cascade that controls cardiovascular, renal, and adrenal function by governing body fluid and electrolyte balance as well as arterial pressure. angiotensin ii (ang ii) is the principal effector peptide of the raas. through its binding to the ang ii type 1 (at1) receptor, it mediates a range of processes, including vasoconstriction, aldosterone, and vasopressin release, sodium and water retention, and sympathetic activation. these, in turn, can lead to the development of hypertension and to the hemodynamic alterations of congestive heart failure (15). angiotensin ii receptor blockers (arb) act by selectively blocking the binding of ang ii to the at1 receptor (16). this study was conducted to measure salivary matrix metalloproteinase -8, in relation to periodontal health condition among a group of patients with hypertension in comparison with control group. materials, and methods subjects: ninety subjects, males only, aged 45-50 years old were included in this study, they were seeking treatment for chest pain. the sample collection was done during the period between the mid of december 2016 and the mid of april 2017 in ibn-al baytar center for cardiac surgical treatments in baghdad, iraq. the subjects were divided into study group (45 patient), and a control group (45 subject), as following: 1-study group: patients who were diagnosed to be hypertensive patients, and use antihypertensive drug. 2control group: patients were collected from treadmill test room, free from hypertension, which scored a negative result in the blood pressure test, and in no need for any antihypertensive drug. inclusion criteria: patients suffering from chest pain, who are: free from chronic systemic diseases. -with a history of hypertension (diagnosed for previous 1 year at least), allowed drugs includes only angiotensin ii receptor blockers (arb):  valsartan 80-320 mg  telmisartan 20-80 mg  losartan 25-100 mg  irbesartan 150-300 mg  azilsartan 40-80 mg  olmesartan 20-40 mg  candesartan 8-32 mg  eprosartan 400-800mg exclusion criteria: 1. patient who had a history of chronic systemic diseases, other than hypertension, including diabetes mellitus, rheumatoid arthritis, which have a known association with the oral inflammation. 2. patients with a previous history of percutaneous coronary interventions and stent placement. 3. patients who are smokers. 4. patient with medication (antiinflammatory or antimicrobial therapy) within previous 3 months. 5. patient who had periodontal treatment within previous 3 months. unstimulated whole saliva samples were collected at a fixed collection time (8-11 a.m.). the patient was advised to quit the intake of any food or beverage (water excluded) one hour before the test session. the subjects were advised to rinse their mouth with water and then to relax for five minutes. the patients were asked to swallow before the beginning of the collection and to lean their head forward over the test tube and minimize mouth movements as possible, and allow saliva to drain into the tube for a 5 minutes (17). clinical parameters examination was done after salivary sample collection. dental plaque assessment was done by using pli system (18) (table 1), and was performed on six index teeth as follow: upper right first molar, upper right lateral incisor, upper left first premolar, lower left first molar, lower left lateral incisor, lower right first premolar. probing pocket depth is defined as the distance from gingival margin to the most apical penetration of the periodontal probe inserted into the gingival crevice or pocket without any force or pressure. by examining four surfaces of all teeth except the third molar for the probing pocket depth index by using the marquis periodontal probe. the sites of measurement were mid-buccal line, mid palatal/lingual line, mesio-buccal, and disto-buccal line angles (19). j bagh college dentistry vol. 30(3), september 2018 salivary matrix 50 the severity of probing pocket depth as following (20): 4-5 mm represents the mild type. 6-7 mm represents the moderate type. <7 mm represents the severe type. clinical attachment level (cal) is defined as the distance from the cemento-enamel junction (cej) to the location of the inserted probe tip (bottom of the gingival crevice or pocket). the measurements were made at four surfaces of each tooth except third molar. the cal was measured indirectly by subtracting the distance from the gingival margin to the cemento-enamel junction from ppd. in some cases where there was gingival recession, attachment level was measured either directly or by adding the distance from the gingival margin to the cej to the ppd. the level of the cej could be determined by feeling it with a probe. assessment of severity was done as following (19): 1 – 2 mm represents the mild type. 3– 4 mm represents the moderate type. ≥ 5 mm represents the severe type. the concentration of salivary mmp8/neutrophil collagenase (mmp-8) was determined by using the supernatant salivary samples by utilizing enzyme linked immune sorbent assay (elisa). elisa kit (96-wells) for quantitative determination of salivary mmp-8 purchased from shanghai yehua biological technology co. this kit uses elisa based on biotin double antibody sandwich technology to assay human mmp-8/neutrophil collagenase (mmp-8). salivary samples were added to wells that are pre-coated with mmp-8/neutrophil collagenase (mmp-8) monoclonal antibody and then incubate. after incubation, add anti mmp-8 antibodies labeled with biotin to unite with streptavidin-hrp, which forms the immune complex. unbound enzymes were removed after incubation by washing. then substrate (chromogenic reagent) a and b were added, the solution will turn blue and change to yellow with the effect of acid. the optical density of mmp-8 in the samples was measured by using spectrophotometer. statistical analysis was determined by t-test and pearson's correlation coefficient test using version 18 (statistical package for social sciences spss). results: table 1 illustrates the mean value and standard deviation of pli among study and control group. the mean values of plaque status were higher among the hypertensive patients than the non-hypertensive patients. however, the difference between the two groups was not significant. table 1: plaque index mean and standard deviation among patients with and without hypertension. group mean ±sd p-value with hypertension 1.603 0.464 0.624 without hypertension 1.553 0.496 the mean values and standard deviations of the cal for the study and control groups are shown in table 2. from the table, it was found that the mean value of cal was statistically not different between the patients with hypertension and non-hypertensive. table 2: clinical attachment level mean and standard deviation among patients with and without hypertension. group mean ±sd p-value with hypertension 2.275 0.880 0.673 without hypertension 2.196 0.877 the mean values and standard deviations of the ppd for the study and control groups are shown in table 3. from the table, it was found that, the patients with hypertension had higher mean value of ppd than non-hypertensive patients. however, the difference was found to be not significant. table 3: probing pocket depth mean and standard deviation among patients with and without hypertension. group mean ±sd p-value with hypertension 2.872 1.947 0.468 without hypertension 2.566 1.990 table 4 illustrates the mean values and standard deviations of salivary mmp-8 between study and control groups. it was found that hypertensive patients showed a statistically (p<0.05) higher mean value of salivary mmp-8 level than that observed for the non-hypertensive group. table 4: matrix metalloproteinase8 mean and standard deviation among patients with and without hypertension. group mean ±sd p-value with hypertension 2.648 1.477 0.030* without hypertension 2.020 1.104 *significant p<0.05 table 5 demonstrates the correlation coefficients between pli, with ppd and cal, among groups of patients with and without hypertension. the j bagh college dentistry vol. 30(3), september 2018 salivary matrix 51 correlations between mean scores of pli and ppd, showed no significant relation in both groups. regarding cal, a different pattern was noted, a positive significant correlation between the pli with cal among both groups. table 5: correlation coefficients between plaque index, with probing pocket depth and clinical attachment level, among groups of patients with and without hypertension. without hypertension with hypertension variable p r p r .0680 .2990 0.980 0.004 ppd *0.000 0.724 *0.000 0.538 cal * significant p<0.05 table 6 shows the correlation coefficients between mean level of salivary mmp-8 with pli, ppd, and cal, among the study and control groups. no significant correlation was detected between salivary mmp-8 with ppd and cal, while the relation between mmp-8 with pli among hypertensive patients, recorded a significant coefficients. table 6: correlation coefficients between matrix metalloproteinase-8 with plaque index, probing pocket depth and clinical attachment level, among patients with and without hypertension. without hypertension with hypertension variable p r p r .8010 .0420 0.033* 0.296 pli 0.813 .040 0.608 0.073 ppd 0.630 0.081 0.349 .1330 cal * significant p<0.05 discussion the study sample consisted of males who were seeking treatment for chest pain, and severe headache, their ages ranged between 45-50 years. the selection of this age group may be attributed to the fact that, long term high blood pressure, is a major risk factor for coronary artery disease and atherosclerosis starts early in life, since disease progression is usually slow, clinical symptoms with or without hospitalization is rare before 40 years of age (21). in the current study, plaque index by silness and loe (18) was used for assessment of dental plaque thickness, this index widely used due to validity, their ease, and feasibility (22). the results of the current study showed that the mean value of the pli was higher among hypertensive group as compared to control group. these results may be due to oral health negligence in the study groups and this could be attributed also to lack of motivation about dental plaque control. in addition to the previous causes, the finding of this study may also be linked to the fact that dental plaque bacteria are considered one of the risk factors for atherosclerosis development (23). circulating microorganisms or their products may promote pathogenesis and enhance local inflammatory changes in vessel walls that may promote clotting and clot formation which lead to hypertension (24). the findings of this study recorded that, the mean values of cal and ppd, for patients suffering from blood hypertension, were higher than that for the healthy subjects. these results may be explained by the well-known association between hypertension and periodontitis which shares common risk factors, such as, stress, increased age, and socioeconomic factors (25). a variety of studies have found various results showing an association between hypertension and periodontitis. these studies documented that hypertensive subjects exhibited a more detrimental periodontal status (26-28). saliva is a complex secretion whose components exert a welldocumented role in health and disease, it is emerging as a viable alternative to blood sampling (29). similar to other biological systems, the salivary system includes various molecules and enzymes (30), in this study, un stimulated saliva was collected, as it is more convenient and easier to obtain the required and adequate quantity of saliva. the biochemical analysis results of this study revealed more mean value of salivary mmp-8 among the hypertensive group than the control group with statistically significant difference, this may be related to the general health of the study group who are having health problems regarding their coronary atherosclerotic condition. current findings agree to some extent with earlier studies in which the respective mmp-8 was higher in hypertensive patients than in healthy subjects (31-33). results also showed positive correlations between mmp-8 mean value with periodontal disease (plaque index, probing pocket depth, and clinical attachment level) among the group complain from blood hypertension, these results may be explained by the fact that mmp-8 is catalytically the most competent proteinase to initiate type i collagen and extracellular matrix degradation associated with periodontal destruction (34). regarding cardiovascular diseases, mmp-8 has been implicated in atherosclerotic plaque https://en.wikipedia.org/wiki/coronary_artery_disease j bagh college dentistry vol. 30(3), september 2018 salivary matrix 52 destabilization and rupture pathologically through its proteolytic ability to thin the protecting collagenous fibrous cap lining coronary and other arteries (35). through these two facts one can perceive parallelisms between 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mortality? findings from 172 630 participants from the prospective 45 and up study. bmj open 2016; 6: e012386. 33furuholm j, sorsa t, qvarnstrom m, janket s, tervahartiala t, nuutinen p, et al. salivary matrix metalloproteinase-8 in patients with and without coronary heart disease may indicate an increased susceptibility to periodontal disease. j periodontal res 2006; 41: 486–9. 34rathnayake n, åkerman s, klinge b, lundegren n, jansson h, tryselius y, et al. salivary biomarkers for detection of systemic diseases. plos one 2013; 8: e61356. 35sorsa t, tervahartiala t, leppilahti j, hernandez m, gamonal j, tuomainen a, et al. collagenase-2 (mmp-8) as a point-of-care biomarker in periodontitis and cardiovascular diseases. therapeutic response to non-antimicrobial properties of tetracyclines. pharmacol res 2011; 63: 108–13. 36castro m, tanus-santos j. inhibition of matrix metalloproteinases (mmps) as a potential strategy to ameliorate hypertension-induced cardiovascular alterations. curr drug targets 2013; 14: 335-43. الخالصة يعد ارتفاع ضغط الدم على االغلب من اهم مشاكل الصحة العامة في الدول المتطورة والنامية . انه منتشر, عديم االعراض, ممكن الخلفية: التوجد او توجد بشكل نادر تداعيات فموية نتيجة جهازية.تشخيصه بسهولة, ومعالجته بسهولة. اذا لم تتم معالجته, في الغالب يؤدي الى مشاكل مزمنة. ارتفاع ضغط الدم ولكن ادوية الضغط تسبب غالبا اثار جانبية. االلتهابات الفموية لها غالبا تداعيات على االمراض الجهازية الحادة وال لمحتمل ان يكون االشخاص المصابين بالتهاب االنسجة ماحول التهاب االنسجة ماحول االسنان هو احد اكثراالمراض الفموية االلتهابية شيوعا. من ا االنسجة االسنان اكثر عرضة للتعرض لخطر االصابة بالنوبات القلبية واالمراض الوعائية. البحوث الحديثة قد بينت ان التاثير االلتهابي اللتهاب االنزيم اللعابي المعدني المحلل التهابية توجد في اللعاب ممكن قياسها. ماحول االسنان يساعد في تكوين الخثرة الدموية داخل االوعية. عدة وسائط و امراض الشريان التاجي. بالضافة لذلك, المستويات اللعابية من االنزيم المعدني المحلل قد تم ربطه مع حدوث ارتفاع الضغط 8-لبروتين المطرس ترتفع في المتالزمات التاجية الحادة. 8-لبروتين المطرس وعالقته بالحالة الصحية لالنسجة ماحول االسنان 8-اقيمت هذه الدراسة لقياس االنزيم اللعابي المعدني المحلل لبروتين المطرس اف الدراسة:اهد ضابطة.المجموعة اللمقارنة مع اوسط مجموعة من مرضى ارتفاع ضغط الدم ب كانوا يبحثون عن عالج الالم الصدر. جمع العينات تم في مركز ابن البيطار للعالجات 40-54تسعون فردا, تتراوح اعمارهم بين المواد والطرق: ممن شخصوا بكونهم مرضى ارتفاع ضغط الدم ,ومجموعة ضابطة مريض( 54الجراحية في بغداد, العراق. تم تقسيمهم الى مجموعة دراسية ) اللثة جيب عمقجس اما (silness & loe, 1964) لتصنيف وفقا لجرثوميةا الصفيحة مقياس استخدام بدون ارتفاع ضغط الدم. تم مريض( 54) navazesh) المحفزمن جميع المرضى حسب اللعاب غير جمع تم(. ,.9111lindhe et alوفقا لتصنيف ) ومستوى االرتباط اللثوي السريري &kumar,2008) 8-لتحليل االنزيم المعدني المحلل لبروتين المطرس. الجرثومية, مستوى االرتباط اللثوي السريري , وجس عمق جيب اللثة اعلى عند المجموعة الصفيحة قيمة متوسط ان النتائج رتاظه: النتائج االرتباط ايجابي قوي وسجلت العالقة فرق معنوي عالي كانالضافة الى ذلك, االمجموعة الضابطة مع عدم وجود فرق معنوي. بب مقارنة الدراسية -, البروتين اللعابي )االنزيم المعدني المحلل لبروتين المطرسالجرثومية و مستوى االرتباط اللثوي السريري وسط المجموعتين ةالصفيح بين قيمة سجل متوسط قيمة اعلى من المجموعة الضابطة مع وجود فرق معنوي بين المجموعتين, وسجل ارتباط ايجابي بين الدراسية ( في المجموعة8 الجرثومية وسط المجموعة الدراسية مع وجود ارتباط معنوي. الصفيحة قيمة( و 8-النزيم المعدني المحلل لبروتين المطرسالبروتين اللعابي )ا االنزيم سجلت امراض االنسجة ماحول االسنان نسبة حدوث عالية بين مرضى ارتفاع ضغط الدم, وجد ايضا ان البروتين اللعابي ) االستنتاجات: .( له تاثير على حالة االنسجة ماحول االسنان في المجموعة الدراسية8-ن المطرس المعدني المحلل لبروتي https://www.ncbi.nlm.nih.gov/pubmed/?term=hernandez%20m%5bauthor%5d&cauthor=true&cauthor_uid=20937384 https://www.ncbi.nlm.nih.gov/pubmed/?term=gamonal%20j%5bauthor%5d&cauthor=true&cauthor_uid=20937384 https://www.ncbi.nlm.nih.gov/pubmed/?term=tuomainen%20am%5bauthor%5d&cauthor=true&cauthor_uid=20937384 https://www.ncbi.nlm.nih.gov/pubmed/?term=castro%20mm%5bauthor%5d&cauthor=true&cauthor_uid=23316965 https://www.ncbi.nlm.nih.gov/pubmed/?term=tanus-santos%20je%5bauthor%5d&cauthor=true&cauthor_uid=23316965 https://www.ncbi.nlm.nih.gov/pubmed/23316965 dropbox 7 omran 34-40.pdf simplify your life j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 121 immunohistochemical expression of basic fibroblast growth factor-2 and heparanase in salivary pleomorphic adenoma riyadh n. mashkoor, b.d.s. (1) ahlam h. majeed, b.d.s., m.sc. (2) nadia s. yas, b.d.s., m.sc., ph.d. (3) abstract background: the aim of this study was to evaluate the expression of fibroblast growth factor-2 and heparanase in salivary pleomorphic adenoma, and to correlate the two studied markers with each other and with clinicopathological parameters including: age, sex, tumor site and histopathological presentation. methods: sections of twenty five formalin-fixed paraffin embedded tissue blocks specimens of salivary pleomorphic adenoma were immunostained using monoclonal antibodies (fibroblast growth factor-2 and heparanase) to assess their expression in this tumor. results: the expression of fibroblast growth factor-2 and heparanase were positive in all pleomorphic adenoma cases (100%). the positive expression of fibroblast growth factor-2 was significantly correlated with histopathological presentation (p-value=0.032), but it was non-significantly correlated with fgf-2 and other clinicopathological parameters (age, sex, tumor site). the positiveexpression of heparanse was non-significantly correlated with the histopathological presentation (p-value=0.088) as well as with other clinicopathological parameters (age, sex, tumor site). statistically significant correlation was found between the expressions of both studied markers (p-value= 0.0005). conclusion: the fibroblast growth factor-2 and heparanase positive expression was noted in all cases of salivary pleomorphic adenoma signifying that both fibroblast growth factor-2 and heparanase might contribute in the biological behavior of pleomorphic adenoma. the highly significant correlation found in the expression of both markers suggests their synergistic and cooperative role in the tumorigenesis of pleomorphic adenoma. keywords: pleomorphic adenoma, fgf-2, heparanases. (j bagh coll dentistry 2014; 26(1):121-127). introduction pleomorphic adenoma (pa) is a benign neoplastic tumor of the salivary glands. it is the most common type of salivary gland tumors and the most common tumor of the parotid gland. it derives its name from the architectural pleomorphism (variable appearance) seen by light microscopy, it is also known as “mixed tumor, salivary gland type”, which describes its pleomorphic appearance as opposed to its dual origin from epithelial and myoepithelial elements (1). clinically, the tumor is usually solitary and presents as a slow growing, painless, firm single nodular mass. isolated nodules are generally outgrowths of the main nodule rather than a multinodular presentation. it is usually mobile unless found in the palate and can cause atrophy of the mandibular ramus when located in the parotid gland. though it is classified as a benign tumor, pleomorphic adenoma have the capacity to grow to large proportions and may undergo malignant transformation to form carcinoma ex pleomorphic adenoma, a risk that increase with time. although it is benign the tumor is aneuploid, it can recur after resection, it invades normal adja (1)master student, department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. (3)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. cent tissue and distant metastases have been reported after long time intervals (2). histologically, it is highly variable in appearance, even within individual tumors. classically it is biphasic and is characterized by an admixture of polygonal epithelial and spindle-shaped myoepithelial elements in a variable background stroma that may be mucoid, myxoid, cartilaginous or hyaline. epithelial elements may be arranged in duct-like structures, sheets, clumps and/or interlacing strands and consist of polygonal, spindle or stellate-shaped cells,areas of squamous metaplasia and epithelial pearls may be present.the tumors are not enveloped but it is surrounded.by a fibrous capsule of varying thickness. the tumors extend through the normal glandular parenchyma in the form of finger-like pseudopodia (1). little is known about specific transcription and growth factors involved in human salivary gland tissue morphogenesis and cytodifferentiation. identification of such molecules through basic research is likely to furnish potential new tools for tumors (3). fibroblast growth factors (fgfs) are one of the largest growth factor families, comprising 22 members with 13%–71% sequence similarity in mammals (4). fgf type 2 (fgf2), or basic fgf, is a prototype member of the family. it interacts with high-affinity receptors (fgf receptors [fgfrs]), which are transmembrane tyrosine kinases; the fgfr1 isoform being its prime target. the j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 122 binding of fgf2 to fgfr1 induces receptor autophosphorylation on several tyrosine residues, which in turn activates downstream effector molecules, leading to the activation of the rasmitogen-activated protein kinase (mapk) cascade (5). this cascade promotes translocation of mapks to the nucleus, where they phosphorylate and directly activate specific target proteins, including transcription factors. fgf2 is also highly expressed in various somatic cell types where it has an intrinsic function in the regulation of cell proliferation, differentiation, and survival. it also regulates self-renewal and immaturity of many tissue-specific stem cells, including cells from the mouse striatum (6), bone marrow mesenchymal stem cells and adipose tissuederived stem cells (7,8). heparanase is an endoglycosidase that degrades heparan sulfate in the extracellular matrix and cell surfaces, and fulfills a significant role in tumor angiogenesis and plays a critical role in fibroblast growth factor-2 bioactivation by facilitating the releases of immobilized fibroblast growth factor-2 from the extracellular matrix (9,10). similarly, heparanase has been shown to facilitate cell invasion associated with autoimmunity, inflammation and angiogenesis (11,12).traditionally, heparanase activity was correlated with the metastatic potential of tumorderived cells, attributed to enhanced cell dissemination as a consequence of heparan sulfate cleavage and remodeling of the extracellular matrix barrier (13,14). materials and methods the sample of this study included twenty five formalin-fixed, paraffin-embedded tissue blocks, diagnosed as salivary pleomorphic adenoma which was dated from (2000 till 2012). the blocks were obtained from al-shaheed ghazi hospital/ medical city /baghdad (12 cases); alkadhimiya teaching hospital (10 cases); the archives of the department of oral and maxillofacial pathology/ college of dentistry/ university of baghdad (3cases). demographic and clinical data provided by the surgeon were obtained from the surgical and pathological reports available with the tissue specimens, including patient's age, sex, clinical presentation, site of the tumor and histopathological description the diagnosis of each case was confirmed by the examining of hematoxylin and eosin (h&e) sections by two specialized pathologists to determine the most predominant histopathological appearances whether it is mostly cellular, stromal or mixed type.two other 4µm thick sections for each case were cut and mounted on positively charged slides (fisher scientific and eschosuperfrost plus (usa) for immunohistochemical staining with monoclonal antibodies: fibroblast growth factor-2 (us. biological) and heparanase (us. biological). positive tissue controls was obtained according antibodies manufacturer's datasheet and added to each test run. evaluation of immunohistochemical results immunohistochemical signal specificity was demonstrated by the absence of immunostaining in the negative control slides and its presence in recommending positive controls. for fgf-2 tumor cells with clear brown cytoplasmic staining pattern were considered positive, and membranous or membranous and cytoplasmic immunoreactivities were considered positive for heparanase. immunohistochemically stained pleomorphic adenoma sections were studied by light microscope under (10x) objective. in each tissue section, five representative fields (areas showed well preserved tumor islands in which the reaction was clearly positive) were selected for fgf-2 and heparanse monoclonal antibodies immunostaining evaluation, with an average of 1000 tumor cell per case and 200 tumor cells per field. only the number of cells that were positive for fgf-2 and positive for heparanse were quantified by counting at least one thousand cells in representative five fields at(40x) objective in each case. membranous or membranous and cytoplasmic immunoreactivities were scored for heparanase, while cytoplasmic expression was the parameter scored for fgf-2 expression. the extent of staining was scored using the following scale: 0 = no staining (negative), i = staining of 0– 5% of tumor cells (very weak positive), ii =staining of 6–25% of cells (weak positive), iii = staining of 26–75% of tumor cells (moderate positive), iv = staining of 76–100% of tumor cells (strong positive) (15). statistical analysis the studied parameters were scored and considered as categorical data thus they presented as count and percentage. the relationship between categories was tested by chi-square test. spearman's rho correlation was applied to assess the linear association between fgf-2 and heparanse. the level of significance was 0.0005 (two-sided) in all statistical testing. results positivefgf-2 immunostaining was detected as brown cytoplasmic staining of the tumor cells, fig. (1,2) positive ihc expression was found in all pleomorphic adenoma casesasillustrated intable (1) whichreveals that only (1) case (4.0%) showed j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 123 v e r y weakpositiveexpression,(8)cases(32.0%) showed weakpositiveexpression, (9) cases(36.0%) showed moderatepositive expression and (7) cases (28.0%) showed strong expression. positive heparanase immunostaining was found in all pleomorphic adenoma casesas brownmembranous ormembranousand cytoplasmic expression. fig (3,4)heparanase immunostaining of the pleomorphic adenoma cases was summarized in table ( 2 ) which reveals that o n l y (1)case(4.0%) showed very weak positive expression, (2) cases (8.0%)showedweakpositive expression while (12) cases(48.0%) showedmoderatepositiveexpression and (10) cases (40%) showed strong positive expression. the positive expression of fibroblast growth factor-2 was non-significantly correlated with age(p=0.737),sex(p =0.456) and tumor site(p =0.765),while there was significant correlation with histopathological presentation(p =0.088) as shown in table (3). the positive expression of heparanase was non significantly correlated with all clinicopathological parameters including age((p=0.737), sex(p =0.456),tumor site(p =0.765) and histopathological presentation(p =0.088);table(4). regarding the correlation between fgf-2 and heparanase ihc expressions, the results of the present study revealed a highly significant correlation between both markers (p= 0.0005) as clarified in table (5). discussion the selection of pleomorphic adenoma in this study is attributed to its consideration as the most common benign salivary gland neoplasm which characterised by neoplastic proliferation of parenchymatous glandular cells along with myoepithelial components, and having a malignant potentiality. also it is the most common type of salivary gland tumor and the most common tumor of the parotid gland(1).regardless of the great variety of the histopathological aspects, the main diagnostic feature was the presence of both epithelial and mesenchymallike tissue (mixed) which was corresponded to (60%) of the cases, cellular (32%) and stromal (8%), this is in agreement with (16)who stated that the mixed histopathological type was the most predominan. growth factors mediate a wide variety of biological processes such as development, tissue repair and tumorigenesis, and also contribute to cellular proliferation and transformation in neoplastic cells(3). of the growth factors that may play important roles in tumor progression, fgf-2 was unique, since it was epithelial, mesodermal and neuroectodermal mitogens as well as being a potent angiogenic factor (17). a variety of studies in vitro and in vivo suggest that alterations in the expression of fgf-2 and its receptor are associated with growth deregulation in neoplastic cells and are thought to contribute to cellular transformation and continued proliferation(18,19). the results of this study showed a positive expression of fgf-2 in all cases of pa with a moderate positivity in (36%) of cases and strong positivity in (28%) of cases, these findings are compatible with previous studies(17,19)who identified fgf-2 in tumor cells and stated that fgf-2 are expressed in neoplastic cells of pa, particullarymyoepithelial cells which may be related to the differentiation of neoplastic myoepithelial cells and mesenchymal-like tissue formation including fibrous, hyaline, myxoid and chondroid tissues. since there is an evidence which suggest that fgf-2 is released from cells through a novel pathway (20), the result of this study and other observations suggest that fgf-2 may be released from tumor cells inducing autocrine tumor cell proliferation in the tubular and solid areas, while in the myxoid and chondroid areas, tumor cells showed to be differentiated and produce an extacellular containing collagen, laminin and tenascin(21,22). fgf-2 was intensely localized in the basement membrane of tubular cells, this storage of fgf-2 in the basement membrane is thought to be stable and temporarily inactive due to its high affinity for heparin -like molecules(23), so immunohistochemical result of this study is consistent with the hypothesis that the expression of fgf-2 may be involved with the regulation of the growth and differentiation of tumor cells(24). heparanase also cleaves perlecan hs in the basement membrane and relases fgf-2, making it available for growth factor-dependent signalling during angiogenesis, wound healing and tumor formation. to the best of our knowledge, the present study is the first of its kind in assessing hp expression immunohistochemically in pa of salivary gland. the expression of heparanase was detected as brown granular membranous\ cytoplasmic localized in tumor cells.the result of this study showed a positive expression of heparanase in all studied cases of pa with a moderate positivity in (48%) of cases and strong positivity in (40%) of cases. since this is a pioneer study in assessing hp in pa, it’s difficult to establish a comparison with other studies however conclusive remarks can be j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 124 withdrawn from other studies on the salivary gland malignancies (25) assumed that heparanase induction contributes to tumor progression through enhanced angiogenesis,release of ecmsequestersd growth factors, generation of bioactive hs fragments and creation of a growthsupportive microenvironment concerning to histopahological presentation ,positive expression was observed in mixed type of tumor (60%) more than cellular type (32%) of cases followed by stromal type(8%) ,there is no study related to be compared with but this may be suitable with the hypothesis that heparanase cleaves perlecan hs in the basement membrane and releases fgf-2 making it available for growth factor-dependent signaling during angiogenesis and tumor formation(25,26), also the bioactivity of fgf-2 may be modulated by its release from ecm as a complex with a fragment of heparanase(25,27)and the high –affinity activation of fgf receptors (fgfrs) and fgfs requires the formation of a ternary complex with hs(28,29), and as mentioned that fgf-2 positivity is more in the mixed type of tumor than cellular and stromal ,so the more positive expression of fgf-2 is a land mark of more positive expression of heparanase. in agreement with the role of the heparanase in releasing fgf-2 from the ecm, the results of the present study revealed that both fgf-2 and heparanase showed similar pattern of expression, they were highly correlated by pearson chi square with significant correlation between either proteins expression was found (p-value=.0005). the correlation between the two markers in pa is firstly done in iraq and no other study correlate between them regarding salivary gland tumor so, the comparison could be withdrawn from other studies regarding other tumor affecting oral cavity. the positive correlation between the two markers agree with chen et al. (30) that showed heparanase mrna and fgf-2 mrna are associated with higher tumor mvd in oscc and shareef et al. (31) also showed, there was significant correlation between the immunohistochemical expression of heparanase and fgf-2 regarding oral squamous cell carcinoma. heparanase degradation of hs could change the availability of fgf-2 in the tumor microenvironment by releasing fgf-2 from the matrix and the cell surface.besides to modifying fgf-2 action, heparanase could alter signaling initiated by multiple heparin binding growth factors (32). it has been revealed that heparanase degradation of cell surface hs can augment the fgf-2 activity, depending on the heparanase concentrations used to alter cell surface hs. fgf2 binding and signaling require hs sequencespecific interactions .depending on the extent of hs degradation, hs sequences, which bind to either fgf-2 or fgfr, could be removed or cryptic sites could be revealed, angiogenesis is dependent multiple components that can be affected by heparanase in the ecm provide binding sites for angiogenic factors such as fgf-2 and vascular endothelial growth factor. cell surface hspg acts as growth factor and adhesion receptors on tumor cells and vascular endothelial cells. modifying the hs may affect tumorigenicity by modifying the responsiveness of multiple receptors to the extracellular environment (33,34). finally, the statistically significant correlation between fgf-2and hp expression revealed in this study suggest their close and synergistic cooperation and co activation in pa. therefore, they could be considered important biomarkers acting together in the angiogenesis, proliferation and aggressiveness of pa. in conclusion: both fgf-2 and hp might contribute in biological behaviour of pa. references 1. stennert e, guntinas-lichius o, klussmann jp, arnold g. histopathology of pleomorphic adenoma in the parotid gland: a prospective unselected series of 100 cases. laryngoscope 2001; 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8: 596-606. 26. vlodavsky i, friedmann y. molecular properties and involvement of heparanase in cancer metastasis and angiogenesis. j clin invest 2001;108: 341–7 27. bame, k. j. heparanases: endoglycosidases that degrade heparan sulfate proteoglycans. glycobiology 2001; 11: 91r-98r 28. pantoliano mw, horlick ra, springer ba, van dyk de, tobery t, wetmore dr, lear jd, nahapetian at, bradley jd, sisk wp. multivalent ligand-receptor binding interactions in the fibroblast growth factor system produce a cooperative growth factor and heparin mechanism for receptor dimerization. biochemistry 1994; 33: 10229-48 29. kan m, wu x, wang f, mckeehan wl. specificity for fibroblast growth factors determined by heparan sulfate in a binary complex with the receptor kinase. j biol chem 1999; 274: 15947-52. 30. chen z, zheng x, feng h. the expression and significance of hparanase and bfgf in oral squamous cell carcinoma. chinesegerman clinical oncology 2009; 8: 46-9 31. shareef kn. immunohistochemical expression of basic fibroblast growth factor-2 and heparanase in oral squamous cell carcinoma. a master thesis in oral pathology, department of oral diagnosis, college of dentistry, university of baghdad, 2012. 32. wu h, barusevicius a, babb j, klein-szanto a, godwin a, elenitsas r, gelfand jm, lessin s, and seykora jt. pleiotrophin expression correlates with melanocytic tumor progression and metastatic potential. j cutan pathol 2005; 32: 125-30. 33. kato m, wang h, kainulainen v, fitzgerald ml, ledbetter s, ornitz dm, bernfield m. physiological degradation converts the soluble syndecan-1 ectodomain from an inhibitor to a potent activator of fgf-2. nat med 1998; 4: 691 – 7 34. liu d, shriver z, venkataraman g, el shabrawi y, and sasisekharan r. tumor cell surface heparan sulfate as cryptic promoters or inhibitors of tumor growth and metastasis. proc natl acad sci usa 2002; 99: 568 – 3. figure 1: positive brown cytoplasmic expression of fgf-2 in cellular, ductal and myxoid components (20x). j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 126 figure 3: positive brown membranous/cytoplasmic immunostaining of heparanase in ductal and cellular components of pa (20x). figure 4: positive brown membranous/cytoplasmic immunostaining of heparanase in ductal and myxoid components of pa (40x). table 1: fgf-2 ihc expression in pleomorphic adenoma cases fgf-2fgf-2 score* no. % i 1 4.0% ii 8 32.0% iii 9 36.0% iv 7 28.0% total 25 100% *i (very weakexpression), ii(weakexpression), iii (moderateexpression),. iv (strong expression) table 2: heparanase ihc expression in pleomorphic adenoma cases heparanasescore* no. % i 1 4.0% ii 2 8.0% iii 12 48.0% iv 10 40% total 25 100% i (very weakexpression), ii (weakexpression), iii (moderate expression), iv(strong expression) figure 2: positive brown cytoplasmic immunostaining of fgf-2 in cellular andductal componenets of pleomorphic adenoma (40x). j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 127 table 3: correlation of fgf-2 with histopathological presentation table 4: correlation of hp expression with histopathological presentation table 5: hp * fgf crosstabulation fgf total hp i ii iii iv i 1 0 0 0 1 100.0% .0% .0% .0% 100.0% 100.0% .0% .0% .0% 4.0% ii 0 1 1 0 2 .0% 50.0% 50.0% .0% 100.0% .0% 12.5% 11.1% .0% 8.0% iii 0 6 4 2 12 .0% 50.0% 33.3% 16.7% 100.0% .0% 75.0% 44.4% 28.6% 48.0% iv 0 1 4 5 10 .0% 10.0% 40.0% 50.0% 100.0% .0% 12.5% 44.4% 71.4% 40.0% total 1 8 9 7 25 4.0% 32.0% 36.0% 28.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% pearson chi-square value df asymp. sig. (2-sided) 30.906 9 .0005 crosstab fgf total histopathology i ii iii iv cellular 0 0 3 5 8 .0% .0% 37.5% 62.5% 100.0% .0% .0% 33.3% 71.4% 32.0% stromal 0 0 2 0 2 .0% .0% 100.0% .0% 100.0% .0% .0% 22.2% .0% 8.0% mixed 1 8 4 2 15 6.7% 53.3% 26.7% 13.3% 100.0% 100.0% 100.0% 44.4% 28.6% 60.0% total 1 8 9 7 25 4.0% 32.0% 36.0% 28.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% pearson chi-square value df asymp. sig. (2-sided) 13.757 6 .032 crosstab hp total histopathology i ii iii iv cellular 0 0 2 6 8 .0% .0% 25.0% 75.0% 100.0% .0% .0% 16.7% 60.0% 32.0% stromal 0 1 1 0 2 .0% 50.0% 50.0% .0% 100.0% .0% 50.0% 8.3% .0% 8.0% mixed 1 1 9 4 15 6.7% 6.7% 60.0% 26.7% 100.0% 100.0% 50.0% 75.0% 40.0% 60.0% total 1 2 12 10 25 4.0% 8.0% 48.0% 40.0% 100.0% 100.0% 100.0% 100.0% 100.0% 100.0% pearson chi-square value df asymp. sig. (2-sided) 11.000 6 0.088 lina final.doc j bagh college dentistry vol. 26(3), september 2014 acceleration of canine orthodontics, pedodontics and preventive dentistry 133 acceleration of canine movement by laser assisted flapless corticotomy [an innovative approach in clinical orthodontics] lina h. salman, b.d.s. (1) fakhri abid ali, b.d.s., m.sc. (2) abstract background: corticotomy-assisted orthodontic treatment is done to induce a state of increased tissue turnover and transient osteopenia, which is followed by a faster rate of orthodontic tooth movement. it considered as an adjunct treatment option for orthodontic treatment of adults. the aim of this study was to elucidate the effectiveness of a new surgical approach for acceleration of maxillary canine retraction in human with laser assisted flapless corticotomy and evaluate its effect on vitality of pulp and gingival sulcus depth. materials and methods: the sample comprised of 15 iraqi patients (9 females and 6 males; mean age 21.7), who were required extraction for their maxillary first premolars followed by retraction of the canines as part of their orthodontic treatment plan. the study was designed as a split-mouth study. decortications were done in the second stage of orthodontic treatment using er:yag laser to perform series of holes mesially and distally to the canine at the side with more space between the canine and second premolar without reflecting a surgical flap. the net canine movements and molar anchorage loss were calculated after six weeks. vitality test, radiographical assessment and gingival sulcus depth were investigated. results and conclusions: the canines on the laser corticotomy side showed statisticaly higher mean value of retraction than their controls during six weeks period. pulp vitality response and post surgery gingival sulcus depth showed no significant difference between the pre-laser and post-laser surgery. based on the result of our study, flapless laser assisted corticotomy can be considered for acceleration of orthodontic tooth movement in humans. key words: er:yag laser, corticotomy, acceleration of tooth movement. (j bagh coll dentistry 2014; 26(3):133-137). الخالصھ ال ذي یتبع ھ ازدی اد س ریع ف ي مع دل الحرك ة . یؤدي نزع قشرة العظم الجراحي ل دعم المعالج ھ التقویمی ھ لالس نان ال ى حال ھ م ن زی ادة مع دل االنت اج النس یجي و نقص ان العظ م المؤق ت .وتعتبر كخیار مساعد للعالج التقویمي للبالغین.التقویمیھ لالسنان اللی زر فعالیھ تدخل جراحي جدید من نوعھ لتس ریع حرك ھ الن اب العل وي ف ي االنس ان بواس طھ تقش یر العظ م جراحی ا ب دون رف ع س دیلھ جراحی ھ وباس تخدام لتقییم :الھدف من الدراسھ .وتقییم تاثیرھا على حیویھ لب السن و عمق اخدود اللثھ المحیط بالسن الذین كان القلع الجراح ي لالس نان الض احكھ العلوی ھ االول ى م ع س حب الح ق ) 21.7معدل العمر , ذكور 6, اناث 9(مریض عراقي 15تكونت عینة الدراسھ من :المواد والطرق دانی ھ تمت عملیة نزع قشرة العظ م ف ي المرحل ھ الثانی ھ م ن الع الج التق ویمي باس تعمال اللی زر لعم ل سلس لة م ن الثق وب للجھ ھ ال . النیاب الفك العلوي جزئا من الخطھ التقویمیھ لعالجھم ت م احتس اب .انی ة م ن الف ك كعنص ر ثاب ت للمقارن ھ والقاصیھ للناب والضاحك الثاني العلویین في جھة الفك التي تكون فیھا المسافھ بین الناب والضاحك الثاني اكبر بینما ابقی ت الجھ ة الث التقییم بواسطة االشعة السینیھ واحتساب عم ق اخ دود اللث ھ المح یط بالس ن ف ي ھ ذه , سنان حصیلة حركھ الناب وفقدان المقاومھ للطواحن بعد ستة اسابیع وتم التحري عن حیویة لب اال .الدراسة ك ذلك ال یوج د ف رق ف ي فق دان مقاوم ة الط واحن م ا ب ین . احصائیا اظھرت الجھة المقشره باللیزر قیم معدل عالیھ للسحب مقارنةبالجھة غیر الجراحیھ خ الل فت رة س تة اس ابیع :النتائج .لم یكن ھناك فرق كبیر بین عمق اخدود اللثھ وقیم االستجابھ الحیویھ للب السن قبل وبعد الجراحھ اللیزریھ. جانبینال .ھ لالسنان في االنسانویمیلنتائج دراستنا ھذه تبین ان التقشیر الجراحي للعظم بدون رفع سدیلھ جراحیھ وباستخدام اللیزر یمكن اعتباره وسیلة لتسریع الحركة التق استنادا: االستنتاج introduction orthodontic treatment is a lengthy procedure, making so many patients with malocclusions reluctant to this treatment. almost every orthodontic patient cares about the possibility of reducing their treatment time. thus it has become a primary goal that new approaches to accelerate orthodontic movement are required: 1-accelerated tooth movement has been tried by pharmacological & chemical agents like vitamin d3, corticosteroids and prostaglandins given locally & systemically (1). 2accelerated tooth movement has been tried by physical agents concomitant with the orthodontic force to augment the mechanical force, e.g, local application of heat, electric current and static magnetic field (2). (1) master student. department of orthodontics, college of dentistry, university of baghdad (2) professor, department of orthodontics, college of dentistry, university of baghdad. 3others used surgical approaches to accelerate tooth movement by means of surgical burs, vertical grooves and\or perforations in the cortical plate (alveolar corticotomy) & selective alveolar decortications which are effective means to increase orthodontic tooth movement (2). case reports have shown that comprehensive orthodontic treatment can be completed in 4-9 months with corticotomy whereas conventional orthodontic treatment takes 18-30 months. however, surgical procedures are considered invasive since the patient is subjected to flap reflection, bone drilling, and cutting by burs, suturing, in addition to the accompanying complications like contamination, pain, and swelling (3-4). recently lasers were introduced to do corticotomy without reflecting a surgical flap in experimental animals, one of these studies was a pilot study on beagles dogs done by hao. the second was on rabbits by seifi and coworkers. j bagh college dentistry vol. 26(3), september 2014 acceleration of canine orthodontics, pedodontics and preventive dentistry 134 they used er; yag laser to do the corticotomy. both studies shows that laser facilitated flapless corticotomy is a useful procedure to speed up treatment time & it eliminates the necessity of invasive flap surgery (5-6). er;yag laser offers an attractive alternative drilling modality because it does not require physical contact with the bone in order to drill holes, cut bone with minimal thermal damage & precise control of bone cutting. this study will be conducted on human for the first time to test the efficiency of laser assisted flapless corticotomy to accelerate tooth movement and to verify the influence of this new approach on tooth vitality as well as on teeth surrounding structures. materials and methods the sample included (15) patients, (5) males and (10) females, with an age ranged from 17-28 years with mean age 21.7 years. males represented 33.33 %, while females represented 66.67% .the patients were informed about the nature of treatment and possible consequences and agreed to participate in the research. a split mouth design were done to ensure more accurate results, so the sample was set up to use each patient as his own control, this led to increase the power of small sample (7). the inclusion criteria: 1. class i malocclusion cases that require bilateral extraction of maxillary and mandibular first premolar, due to sever crowding. 2. class ii malocclusion cases due to maxillary alveolodental protrusion with the general facial type toward a mesiognathic face requiring bilateral extraction of maxillary first premolar and bilateral maxillary canine retraction as part of their orthodontic treatment plan. 3. clinically healthy patients with no history of drug intake and\or no history for any systemic illness, syndromes, craniofacial deformities. 4. no history of previous orthodontic treatment. 5. vital teeth with normal periodontium and no root resorption. (seen by p.a for upper laterals, canines and second premolars for right & left sides, opg, cephalometric x-rays for proper diagnosis & examined by pulp tester ). 6. nearly equal upper and lower facial height excluding any maxillary excess. 7. presence of upper and lower first and second molars. 8. no open bite, facial asymmetry, mandibular deviation or displacement. 9. no previous first premolar extraction. all the patients who participated in this study were informed in simple language about the goal of the research and informed consent was obtained from the patients and from the parents of those younger than 18 years before the study. all the patients were examined clinically and diagnostic case sheets were filled for every patient. after completing the leveling and alignment stage the following steps were done: apre surgerical steps. blaser assisted corticotomy and retraction of canine. cmonitoring visits. dsix weeks after surgery. a-pre surgerical steps: [the whole steps were done at same day of surgery]. 1. pulp vitality testing. 2. gingival health and pocket depth assessment. 3. periapical radiograph. 4. dental cast preparation blaserassisted corticotomy and retraction of canine: corticotomy was done at the side having more space between the canine and the second premolar. the laser device (k.a.v.o laser) was present at al-elwea specialized center in baghdad and the participants were taken to this center to have the operation there. each patient was instructed to use chlorhexidine mouth wash before any surgical intervention and before anesthetic administration. the use of an infiltration anesthetic was recommended for painsensitive patients. less sensitive patients can be given a surface anesthetic by using small cotton pellet soaked with anesthetic solution on the determined site for surgery for ½ minute to avoid ulceration of oral mucosa. if no anesthetic is administered, the patient should be informed that he/she might experience a sensation of warmth in the mucous area that the sensation will disappear after treatment has ended. each patient needed a periapical x-ray for the side of operation to determine the accurate position of the holes between the roots. in this situation a temporary arch wire was put (0.018 inch s.s) with two u-loops (indicator loops) one was between maxillary lateral incisor and maxillary canine and the other was between the maxillary canine and the 2nd premolar as shown in (figure 1). a series of circular holes (4 holes) were made along the planned position. these holes were 2-3 mm apart and their spacing was determined j bagh college dentistry vol. 26(3), september 2014 acceleration of canine orthodontics, pedodontics and preventive dentistry 135 according to the depth of the buccal vestibule (as we did not reflect a surgical flap). each hole was approximately 1.5 mm in diameter. the depth of laser cutting was measured and controlled continuously during the operation by unc 15 periodontal probe with stopper read about 3mm depth in addition to a few parts of a millimeter depth into the medullary bone to enhance bleeding. the whole surgical procedure was done in two major steps with two different parameters: asoft tissue incision by kavo laser device using special hand piece with fibreoptic delivery system. bhard tissue cutting by er:yag laser using parameters for bone ablation and another type of hand piece in non contact mode with constant water spray irrigation . the surgical site was covered by iodoform gauze and surgical pack was placed over it to prevent contamination of surgery site by saliva and food debris (figure 2 & 3). c-monitoring visits: the patients came after one week of surgery to remove the surgical pack (figure 4). d. six weeks after surgery: in this visit all the patients had a periapical radiography for the maxillary canine at the site of operation to exclude any root resorption or periapical pathology. also vitality testing was done for the lateral incisor, canine and second premolar. gingival sulcus depth was measured for the maxillary canine; finally an impression for the upper arch was taken for each patient. figure 1: u-loops in place figure 2: soft tissue incision using laser handpiece e 2055/2062 with fibre insert 50/10. figure 3: hard tissue ablation in non contact mode mesial to the canine. figure 4: surgical site after removal of surgical pack. results 1canine movement the net canine movement per six weeks for both surgical and nonsurgical sides was calculated and the results were expressed by descriptive statistics including (mean, sd, min. and max. values) and inferential statistics. the laser side (surgical side) showed a higher mean value as compared with the control side (non-surgical side) which was statistically highly significant according to t-test. it means that the surgical side demonstrated double net canine distalization than the non-surgical side, as shown in (figure 5). j bagh college dentistry vol. 26(3), september 2014 acceleration of canine orthodontics, pedodontics and preventive dentistry 136 figure 5: net canine movement in both surgical (experimental) and non-surgical (control) sides. gingival sulcus depth a comparison between the pre and postsurgery gingival sulcus depth values of laser surgical side, the values did not exceed 4 mm pre and post-surgery. according to t-test there is no significant change in the gingival sulcus depth. (figure 6) shows a chart demonstrating this comparison. clinical complications and side effects: there were no serious complications after laser surgery; one patient had post operative swelling for one to two days after the surgery. according to bleeding on probing index during the monitoring visits, there was no sign of gingival inflammation or any scar formation on the experimental side. figure 6: preand postgingival sulcus depth in the laser side discussion speed up of canine retraction: the choice of doing selective corticotomy to the canine during retraction in this study was due to the fact that canine retraction is a common treatment procedure in orthodontics. osteotomy in this study was restricted to the cortical layer [selected decortications] to minimize the injury of the vital structures. it was observed that there is a direct correlation between severity of surgical insult and intensity of regional acceleratory phenomenon (8). this finding suggests that reduction in the area of decortication will affect negatively the acceleration of orthodontic tooth movement. but we should also take in consideration that a very few patients accept the risk of very wide area of corticotomy despite the attractive results of corticotomy in speeding up orthodontic treatment. so our question here is: would selective decortication mesiobuccal & distobuccal to the canine that subject to retraction be effective in acceleration of orthodontic tooth movement? the results of our study shows the answer to that question, as the net canine movement during retraction period of 6 weeks was in an average of 1.63 mm, and in the control side (non-laser) in an average of 0.82 mm this means that the canine in the laser side moved twice the amount of that in the control side, i.e. it needs half the time required of that in the control side. so the canines in the laser side moved 67% comparing to their controls which were moved only 33% in the whole period of retraction. gingivitis and gingival sulcus depth the successful prevention of gingival inflammation throughout the study period was attributed to the firm instructions about the proper oral hygiene maintenance given to the patients throughout the study, including the use of a special orthodontic brushes and mouth rinses. radiographic assessment the majority of our examined teeth were radiographically normal and exhibited no pathological change in the pdl which means complete healing of laser-decortication side and good bone turnover which is related to proper and non-invasive surgical intervention. effect on vitality of pulp the use of nontraumatic surgical intervention in the laser surgical side, also we can add additional safety measure which was the use of optimal physiologic force that did not endanger pulp vitality. references 1. al-hasani nr. clinical significance of calcitriol local injection in orthodontic tooth movement. a master thesis, college of pharmacy, baghdad university, 2011. j bagh college dentistry vol. 26(3), september 2014 acceleration of canine orthodontics, pedodontics and preventive dentistry 137 2. krishnan v, davidovitch z. biological mechanisms of tooth movement. 1st ed. john wiley & sons; 2009. 9p.14. 3. wilcko wm, wilcko mt, bouquot je, ferguson dj. accelerated orthodontics with alveolar reshaping. j ortho pract 2000; 10: 63–70. 4. wilcko wm, wilcko t, bouquot je, ferguson dj. rapid orthodontics with alveolar reshaping: two case reports of decrowding. int j periodont restorat dent 2001; 21: 9–19. 5. hao j. accelerated orthodontic tooth movement with flap-less corticotomy: a pilot study in beagle dogs. m.s., university of illinois at chicago 2011; 52: 1492984. 6. seifi m, younessian f, ameli n. the innovated laser assisted flapless corticotomy to enhance orthodontic tooth movement. j lasers med sci 2012; 3(1): 20-5 7. fischer tj. orthodontic treatment acceleration with corticotomy assisted exposure of palatally impacted canines. angle orthod 2007; 77: 417-20. (ivsl). 8. frost hm. the regional acceleratory phenomena. a review. henry ford hosp med j 1983; 31: 3-9. j bagh college dentistry vol. 29(1), march 2017 the effect of artificial restorative dentistry 39 the effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements (a comparative in vitro study) shatha kh. hussain, b.d.s. (1) inas i. al-rawi, b.d.s., m.sc. (2) abstract background: color changes that are detectable to human eye can affect the esthetic appearance of ceramic veneers. the purpose of this study was to evaluate and compare the effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements. materials and methods: sixty discs were prepared with 0.5 mm thickness, 30 discs made from ips e.max press (ivoclar vivadent) and 30 discs were made from vita enamic (vita zahnfabrik). the discs were cemented with three resin cements: variolink veneer mv 0 shade (ivoclar vivadent), rely x veneer translucent shade (3m espe) and nx3 nexus clear shade (kerr corporation) with 0.1 mm thickness. the spectrophotometer easyshade advance was used to measure the color parameters (lightness, axis a* of chroma and axis b*of chroma) immediately after cementation, after 150 and 300 hours of aging. the specimens were subjected to artificial accelerated aging in accelerated weathering tester. color change greater than 3.3 was considered unacceptable. one-way anova, paired t-tests and bonferroni adjusted t-test were used for statistical analysis (p <0.05). results: artificial aging caused high significant color change in both ceramic types, but there were non-significant difference in color change among the three resin cements used. the color change was between1.997-14.8 after 150 hours and it was between 2.179-15.68 after 300 hours. the color change of e.max discs after aging were within acceptable limit<3.3 whereas vita enamic specimens had shown unacceptable color change >3.3 after aging. conclusions: the majority of color change after aging related to veneering materials while resin cement have only slight effect on color change after aging. ips e.max had shown an acceptable color change after aging, so it is suitable for fabrication of restorations in esthetic zone while vita enamic should not be used in esthetic zone since it has poor color stability according to the results of this study. keywords: ceramic veneers, artificial accelerated aging, spectrophotometer, color stability. (j bagh coll dentistry 2017; 29(1):39-46) . introduction ceramic veneer have been a popular treatment option of anterior teeth especially for patients who looking for conservative and best esthetic treatment since these restorations require minimum reduction of tooth structure when compared with another restorations (1). one of major concern in dentistry is to obtain the perfect color that resembles the color of natural teeth with artificial materials (2). ceramic restorations are one of most important restorations that can achieve light scattering and transmission that are resemble the appearance of natural teeth (3). assessment of the color of both teeth and restorations accurately is critical for effective communication with dental laboratory and for successful clinical outcome (1) master student, conservative departments, college of dentistry, university of baghdad. (2) professor, conservative departments, college of dentistry, university of baghdad. the color assessments that performed with visual techniques are subjective and to eliminate the subjectivity of human eye electronic intraoral devices such as colorimeter and spectrophotometer were introduced. these electronic devices measure the color of restorations using commission internationale de l'eclairage (international commission on illumination) cie l*a*b* color system (4). the increased concern on esthetic appearance in today's society had led to consider the color stability of esthetic restoration as critical factor for long-term success of such restorations (5). the color stability is an important factor for direct and indirect esthetic restoration and is a fundamental to the success of the restorative treatment (6). the difference in the color determined whether the color change can be noticeable by human eye since ∆e<1 is not detectable by human eye and ∆e greater than 1 and less than 3.3 considered noticeable but clinically acceptable while ∆e>3.3 considered clinically unacceptable (7). in order to evaluate the long-term color stability of cemented veneer the artificial j bagh college dentistry vol. 29(1), march 2017 the effect of artificial restorative dentistry 40 accelerated aging was used. to simulate the conditions to which the restorations will exposed in the oral cavity for a relatively long time the accelerated aging that use ultraviolet light, humidity and temperature is most commonly used (8). the aim of this in vitro study was to evaluate and compare the effect of artificial accelerated aging (ultraviolet light, humidity and temperature) on the color of ceramic veneers which made from ips e max press and vita enamic and cemented with three different resin cements. materials and methods a total of sixty discs that have a diameter of 10 mm and 0.5 mm thickness were prepared. thirty discs were made from (ips e max press, ht a1 shade, ivoclar vivadent) and thirty discs were made from (vita enamic blocks, ht 1m1 shade, vita zahnfabrik). the specimens that made from e max were fabricated by using of hot pressing technique according to the manufacturer instructions. the discs were finished with dcb grinder cone (komet brasseler, usa) then a single layer of ips ceram glaze were applied on one surface of the discs (8). the specimens that made from vita enamic blocks were prepared by using custom made milling machine which milled the blocks into cylinders then cut the cylinders into the discs with the desired dimensions. the discs made from vita enamic were glazed with vita enamic glaze which is a light cure glazing material, and it required treatment of each disc with 5% hydrofluoric acid, the etched surface were silanated with monobond n for 60 second after that a single layer of vita enamic glaze was applied and light cured according to manufacturer instructions. all of the 60 discs were ultrasonically cleaned in distilled water for 10 minutes before and after glazing then digital caliper was used to make sure that all the discs have 10 mm diameter and 0.5 mm thickness (9). then the e max discs were divided into 3 groups (a1, a2, a3) and vita enamic discs divided into 3 groups (b1, b2, b3): a1: 10 discs of ips e max cemented with variolink veneer resin cement a2: 10 discs of ips e max cemented with relyx veneer resin cement a3: 10 discs of ips e max cemented with nx3 nexus resin cement b1: 10 discs of vita enamic cemented with variolink veneer resin cement b2: 10 discs of vita enamic cemented with relyx veneer resin cement b3:10 discs of vita enamic cemented with nx3 nexus resin cement for cementation unglazed surface of all discs were etched with 5% hydrofluoric acid (ips ceramic refill, ivoclar vivadent), e max discs were etched for 20 secconds while vita enamic discs were etched for 60 seconds. then the discs were rinsed with water spray for 30 seconds and dried (10). afterward the discs of group a and group b were silanated with monobond n (ivoclar/vivadent /clinical, lienchtenstein) which was dispensed on the etched surface of the discs with microbrush for 60 seconds then lightly dried for 5 seconds to evaporate the solvent according to manufacturer instruction. three light cured resin cements were used which are variolink veneer (ivoclar/vivadent /clinical, lienchtenstein ) that have medium value 0 shade, relyx veneer translucent shade (3m espe, usa) and nx3 nexus light cure which have clear shade (kerr corporation, usa). the discs were placed on glass slide then the resin cements were applied from the syringe directly on the silanated surface of discs (9). afterward the mylar strip was placed over the cement (11, 12) then another glass slide was placed over the strip. weight of 1kg was applied over the glass slide for 20 seconds to produce a thickness of resin cement that is equal to 0.1 mm (9, 13). to simulate the clinical condition the cements were light cured from the glazed surface. to remove the excess of the cement the discs were tack-cured for 1-3 seconds to convert the excess into a gel state then the excess gel was removed with dental probe. then cement was completely light cured according to manufacturer instruction (for variolink veneer 30 seconds, for relyx veneer 30 seconds and for nx3 nexus 20 seconds). digital caliper was used after cementation to ensure that the thickness of all specimens were 0.6 mm (8). color measurement was made by using of easyshade advance (vita zahnfabrik, bad sackingen, germany) which consist of base unit and handpiece (14). during color measurement the discs were placed on polywax (bilkim co.ltd, turkey) that had the shade of a3. this polywax was used to simulate the underlying dental tissues (15). the single tooth mode was selected then the spectrophotometer was calibrated according to manufacturer instruction. the probe of the device was placed in the center of the disc and perpendicular to the disc and the button of the device was pressed and the shade appeared in both vita classical and vita 3d master shades and the j bagh college dentistry vol. 29(1), march 2017 the effect of artificial restorative dentistry 41 color parameter (hue, chroma, lightness l*, a* and b*) displayed on the screen of the device (16, 17). three measurements were made for each disc while the probe of the device was in the center of the disc and the mean of the three measurements was calculated as initial color of the disc and used for data analysis (9, 12, 17). the specimens were undergoing accelerated aging test using accelerated weathering tester (quv/spray) (q-lab corporation, usa). the specimens were placed in custom made aluminum holders; these holders have the same dimension of the specimens (10 mm diameter and 0.5 mm depth). then the holders were attached to accelerated weathering tester in which only the glazed surface of the discs were exposed to artificial accelerated aging and the specimens stored in the device for 300 hours. in accelerated weathering tester the specimens were subjected to 150 cycles of aging each cycle was two hours long. within each cycle the specimens were exposed to ultraviolet light for 1 hour and 42 minutes and distilled water spray for 18 minutes and the temperature was 50oc (18). according to the manufacturer of the accelerated weathering tester the 300 hours of aging is equivalent to one year in clinical service (19). after the passage of 150 hours during which the specimens were inside the accelerated weathering tester, color parameters of the specimens were measured again. the discs were also placed on polywax and easyshade advance was used to measure the color of specimens after 150 hours of aging. the 150 hours in accelerated weathering tester is equal to 6 months intraorally (20). the color difference ∆e calculated from l*, a*, b* before and after aging for 150 hours using the following equation: ∆e= [(∆l)2 + (∆a*)2 + (∆b*)2]1/2 where ∆e represent color difference, ∆l, ∆a and ∆b are the difference in color parameters of the specimens before and after aging (21). at the end of aging period (300 hours) the color parameters of the specimens were measured again and the color difference were obtained from the same equation. the results of this study were analyzed with one-way anova, paired t-tests and bonferroni adjusted t-test (p <0.05). results at the baseline anova test revealed high significant difference in lightness (p=0.002) and axis a* of chroma (p <0.001) among the three resin cements when used with e max, while the same test show high significant difference among the three cements when used with vita enamic only in axis a* of chroma (p<0.001) at the baseline. bonferroni adjusted t-test showed statistically significant differences in mean chromaticity (axis a* and axis b*) between e max and vita enamic in each cement group at the baseline. the mean and standard deviation of color change after 150 hours and 300 hours of aging are shown in (table1). the results of this study revealed that after 150 hours of aging the highest color change was found in group b1 (14.8 ±1.873) and the least color change recorded in group a3 (1.997± 0.503), also after 300 hours of aging group b1 recorded the highest color change (15.68±1.748) and the least color change was (2.179±0.482) which is found in group a3. the results of paired t-test had shown that there were statistically highly significant difference in color change after 150 hours and after 300 hours of aging in the six groups (p<0.001), also the color difference between the two periods of aging was statistically high significant (table 1). within group a and after 150 hours and 300 hours of aging the use of variolink veneer with e max (a1) was associated with the highest mean of color change, followed by relyx veneer with e max (a2) and the least color change was found when nx3 nexus was used with e max (a3). bonferroni adjusted t-test had shown that the difference in the effect of the three resin cements on the mean color change after aging was statistically not significant. within group b and after 150 hours and 300 hours of aging the use of variolink veneer with vita enamic (b1) recorded the highest mean of color change, followed by relyx veneer with vita enamic (b2) and the least color change recorded in (b3) in which nx3 nexus was used with vita enamic. bonferroni adjusted t-test had shown that the difference in the effect of the three resin cements on mean color change after aging was statistically not significant. j bagh college dentistry vol. 29(1), march 2017 the effect of artificial restorative dentistry 42 table 1: range, mean, standard deviation, standard error and p (paired t-test) of color change after 150 hours, 300 hours of aging and color difference between 300 hours and 150 hours of aging. when comparing the mean color difference between group a and group b (e max and vita enamic) in the same type of cement after the two periods of aging the use of e max associated with the least color change and bonferroni adjusted ttest revealed that there were statistically significant ∆e after 150h of aging ∆e after 300h of aging ∆e between 300h and 150h of aging a1 range (1.261 to 4.943) (1.473 to 5.288) (0.225 to 0.381) mean 3.017 3.262 0.302 sd 1.053 1.079 0.062 se 0.333 0.3413 0.0196 n 10 10 10 p(paired t-test) <0.001 <0.001 <0.001 a2 range (1.465 to 3.467) (1.626 to 3.628) (0.111 to 0.525) mean 2.501 2.715 0.283 sd 0.685 0.655 0.111 se 0.2166 0.2073 0.0352 n 10 10 10 p(paired t-test) <0.001 <0.001 <0.001 a3 range (1.491 to 2.921) (1.717 to 3.048) (0.125 to 0.436) mean 1.997 2.179 0.253 sd 0.503 0.482 0.092 se 0.1591 0.1524 0.0292 n 10 10 10 p(paired t-test) <0.001 <0.001 <0.001 b1 range (12.907 to 18.484) (13.646 to 19.043) (0.645 to 1.806) mean 14.8 15.68 1.17 sd 1.873 1.748 0.29 se 0.5924 0.5527 0.0916 n 10 10 10 p(paired t-test) <0.001 <0.001 <0.001 b2 range (12.429 to 16.252) (12.028 to 18.059) (0.454 to 1.369) mean 14.668 15.437 0.95 sd 1.225 1.632 0.289 se 0.3875 0.516 0.0915 n 10 10 10 p(paired t-test) <0.001 <0.001 <0.001 b3 range (11.872 to 15.926) (12.96 to 16.717) (0.446 to 1.109) mean 14.159 14.813 0.822 sd 1.174 1.095 0.231 se 0.3713 0.3462 0.0732 n 10 10 10 p(paired t-test) <0.001 <0.001 <0.001 j bagh college dentistry vol. 29(1), march 2017 the effect of artificial restorative dentistry 43 difference in mean color change between e max and vita enamic in each cement type. in spite of that color change of group a1, a2 and a3 after the two periods of aging was statistically significant, the color changes of these groups are considered detectable but clinically acceptable since the color changes in these groups less than 3.3. discussion in this study the specimens were prepared from ips e max press and vita enamic blocks. ips e max press which is lithium disilicate glass ceramic was used because of its unique properties and it had been used most frequently in fabrication of veneers in recent years (22). vita enamic was selected for this study due to its hybrid structure which composed of interpenetrating two networks. these interpenetrating networks consist of ceramic which is porous and polymer which infiltrated within the ceramic, that make the material have the advantages of ceramic and composite (23, 24). the specimens thickness of 0.5 mm was selected to evaluate the effect of artificial accelerated aging on the color of cemented veneers because veneers are conservative restoration and the preparation should be within the enamel to ensure optimal bonding of the veneers to tooth structure, so the recommended preparation for veneers 0.5-0.7 mm (9, 25). in this study the color stability of resin cements that are covered by ceramic and isolated from the surrounding environment was evaluated to simulate the clinical condition(9). in order to simulate the condition in the oral cavity for a relatively long service time artificial accelerated aging was used. accelerated aging test permit the determination of color change that occurred in restorative materials over time (7). in accelerated aging device the restorative materials exposed to ultraviolet light, changes in temperature and humidity in an attempt to simulate the oral environment as closely as possible (26). according to the manufacturer of the accelerated aging device 300 hours is equal to one year inside the patient mouth and most of color change that occurred in restorative materials developed in the first 100 hours (27). at the baseline anova test revealed high significant difference in lightness (p=0.002) and axis a * of chroma (p<0.001) among the three resin cements when used with e max, while the same test showed highly significant difference among the three cements when used with vita enamic only in axis a* of chroma, these differences in (l* ,a*,b*) values among the three cements in both groups (e max and vita enamic) could be due to difference in the number and size of filler of resin cement as the color of composite materials affected by the filler particle size and number (8,28). at the baseline there was statistically significant difference in the mean of both axis of chromaticity (a* and b*) between vita enamic and e max in each cement and this could be due to that the materials from different brands may have the same shade but have differences in color parameters and this in agreement with chang et al (29) who found that resin cements from different companies which have the same shades show differences in l*, a*, b* values. after 150 hours of aging, all groups had shown statistically high significant differences in mean color changes. within group a, a1 showed the highest mean color change (3.017±1.053) while a3 showed the least color difference (1.997±0.503). however these difference in mean color change among the three cements was statistically non-significant and this in agreement with turgut and bagis (9) who had study the color stability of veneers made from different shades of e max and cemented with resin cements from different brands and different shades and they found that high translucent shade of e max with medium value of variolink veneer show more color change after aging than high translucent shade of e max with translucent shade of relyx veneer. these differences in color change among the three groups (a1, a2, a3) may be attributed to difference in composition of the three resin cements and the affinity of their resin matrix to absorb water since the resin matrix considered as the source of discoloration so the higher fraction of resin matrix per volume the higher color change will result (30, 31). within group b, the differences in mean color change among the three resin cements was not significant and b1 had shown the highest mean color change (14.8±1.873) and b3 had shown the least color change after aging (14.159±1.174). in both groups (a, b) the use of variolink veneer resin cement is associated with the highest mean of color change, while nx3 nexus show the least mean of color difference. variolink veneer showed the highest mean of color difference may be due to its filler load per volume is the least when compared with the other two cements (variolink 40%vol., rely x 47%vol., nx3 nexus 47.7%vol.). variolink have more resin matrix than the two other cements, so it associated with the greater j bagh college dentistry vol. 29(1), march 2017 the effect of artificial restorative dentistry 44 water sorption which is responsible for color change (32-34). vita enamic had shown higher color change than ips e max when used with the same cement. vita enamic had shown very high color change after exposure to artificial accelerated aging may be due to the presence of polymer which comprised 25% of its volume. this polymer composed of urethane dimethacrylate (udma) and triethylene glycol dimethacrylate (tegdma). udma have very low water sorption so it is associated with less color change. however, tegdma is very hydrophilic and increase the hydrophilicity of the surface that results in an increase in water sorption which leads to color change. tegdma increase water sorption due to ether linkages which is hydrophilic (35-38). vita enamic had shown color instability after 150 hours and require replacement and this disagree with the manufacturer claim that the material is color stable and with dirxen et al (24) who had tested vita enamic crowns in patient mouth for two weeks and found that the crowns weren't show any color change. the color change of ips e max may resulted from the metal oxide which added to ceramic to obtain the color shades and under the ultraviolet light these metal oxides are very easily break down and peroxides compound may developed and result in color change (27). the difference in the color between the color of the materials after 300 hours of aging and the color of the materials after 150 hours of aging had shown statistically significant difference, however these color changes were very small and clinically unnoticeable by human eye. when comparing the color difference in the first 150 hours and the second 150 hours of aging, most of color change occur in the first period and in the second period there was slight color change and this in agreement with cao et al (39) and ghavam et al (40) who were stated that most color difference occur in the first 100 hours of aging. cao et al have been studied the effect of accelerated aging on the color stability of alumina-based and leucite –based ceramics and found that the first 100 hours of aging produced the major color change, while ghavam et al had studied the effect of accelerated aging on color stability of resin cements and concluded that the majority of color change occur in the first 100 hours of aging. after the passage of the half of artificial aging periods (150 h ) and also at the end of aging period (300 h) the percentage of vita enamic specimens that show color change > 3.3 was 100%, while the percentage of e max specimens which had color change >3.3 after 150 h was 16.7% and their percentage after 300 h was 20%. in spite of that the color change within groups a1, a2, a3 was statistically significant after 150 hours and 300 hours of aging, but the color change within these groups remain within the acceptable color change clinically and this in agreement with turgut and bagis (9) who had study the color stability of veneers fabricated from different shades of ips e max press cemented with different shades of different resin cements. conclusions within the limitations of this in vitro study, the following conclusions were found: 1. both restorative materials (ips e max press and vita enamic) used in this study had shown significant color change after accelerated aging. 2. ips e max press showed color change after aging that can be considered acceptable clinically because color difference was below 3.3 units, so this material is suitable to be used for fabrication of restorations in esthetic zone. 3. vita enamic after aging showed color change that considered unacceptable clinically and this material should be avoided in fabrication of restorations in esthetic zone. 4. there was no significant difference in the effect of the three different resin cements used in the study on color change after aging process, but nx3 nexus may considered the best for luting veneers since it is associated with the least color change after aging. 5. the majority of color change after accelerated aging related to change in the color of veneering materials rather than luting cements. 6. most of the color change of veneering materials appears in the first 150 hours (6 months) of aging. refrences 1. dozic a, tsagkari m, khashayar g, aboushelib m. color management of porcelain veneers: influence of dentin and resin cement colors. quintessence international 2010; 41(7):567-573 2. vichi a, ferrari m, davidson cl. color and opacity variations in three different resin-based 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nano-hybrid resin based composite. eur j gen dent 2014; 3(3):190-193. 35. ferracane jl. hygroscopic and hydrolytic effects in dental polymer networks. dental materials 2006; 22: 211– 222. 36. topcu ft, sahinkesen g, erdemir u, oktay ea, ersahan s. influence of different drinks on the colour stability of dental resin composites. european journal of dentistry 2009; 3: 51-56. 37. abd alhadi n, jabbar am, kadhim aj. effect of 38% hydrogen peroxide agent on color change of composite resins stained with tea and coffee beverages (an in vitro study). mdj2012; 9(2):149-158. http://www.sciencedirect.com/science/article/pii/s0022391300512451 http://www.oralhealthgroup.com/news/the-science-behind-lithium-disilicate-today-s-surprisingly-versatile-esthetic--durable-metal-free-al/1000229938/?&er=na http://www.oralhealthgroup.com/news/the-science-behind-lithium-disilicate-today-s-surprisingly-versatile-esthetic--durable-metal-free-al/1000229938/?&er=na http://www.oralhealthgroup.com/news/the-science-behind-lithium-disilicate-today-s-surprisingly-versatile-esthetic--durable-metal-free-al/1000229938/?&er=na j bagh college dentistry vol. 29(1), march 2017 the effect of artificial restorative dentistry 46 38. kaleem m, khan as, rehman iu, wong fs. effect of beverages on viscoelastic properties of resin-based dental composites. materials 2015; 8(6):2863-2872. 39. cao j, he h, wang z. color stability against accelerated aging of aluminaand leucite –based ceramic materials.int chin j dent 2007;7:49-52. 40. ghavam m, amani-tehran m, saffarpour m. effect of accelerated aging on the color and opacity of resin cements. operative dentistry 2010; 35(6); 605-609. الخالصة ييم ومقارنة تأثير التعتيق تغير اللون الذي يمكن تمييزه من قبل العين البشرية يمكن ان يؤثر على المظهر الجمالي للقشور الخزفية. الغرض من هذه الدراسة كان لتق المجموعة أ((ثالثون قرص ملم, 5.0انواع مختلفة من االسمنت الراتنجي. تم اعداد ستون قرص ذات سمك الصناعي المعجل على لون القشور الخزفية المثبتة باستخدام (.(vita enamic ,vita zahnfabrikصنعت من )المجموعة ب( (والثالثون قرص االخرى ips e max press,ivoclar vivadent)صنعت من variolink veneer, ivoclar vivadent(,)relyx veneer, 3m espe(,)nx3)[ملم 5.0وبسمكثالثة انواع من االسمنت الراتنجي استخدمت nexus, kerr corporation )[ استخدم المطياف(easyshade advance) )بعد لقياس ابعاد اللون )سطوع اللون والمحور أ وب من كثافة اللون ساعة من التعتيق. تم تعريض العينات للتعتيق الصناعي المعجل في جهاز التجوية 355ساعة و005اضافة االسمنت الراتنجي لالقراص وبعد مرور (accelerated weathering tester) غير مقبول في هذه الدراسة. تم تحليل النتائج احصائيا 3.3تم اعتبار تغير اللون االكبر من ساعة. 355لمدة اظهرت .5.50( عند مستوى معنوي اصغر من bonferroni adjusted t-testو اختبار ) ( paired t-test) اختبار االقتران (,anovaباستخدام اختبار ) ر اللون بين الثالثة انواع من النتائج ان التعتيق الصناعي قد تسبب بتغير مهم للون كال نوعي السيراميك المستخدمين في الدراسة, ولكن لم يكن هناك فرق كبير في تغي ولكن االقراص والذي يعتبر تغير مقبول, 3.3( قد اظهرت تغير في اللون اقل من ips e max press) االقراص المصنوعة من ي المستخدمة.االسمنت الراتنج الغالبية العظمى من تغير اللون بعد التعتيق كان ( اظهرت تغير غير مقبول في اللون. وفقا لنتائج هذه الدراسة يمكن ان نستنتج بأنvita enamic) المصنوعة من تغير مقبول ips e max) اظهرت مادة ) .االسمنت الراتنجي بعد التعتيق لم يكن له اثر كبير على تغير اللون. بعد التعتيق بسبب مادة القشور الخزفية المستخدمة وان ( ال ينبغي ان تستخدم في ترميم االسنان ضمن المنطقة الجمالية ألنها vita enamic) ة في حين مادةفي اللون لذلك هي مناسبة لترميم االسنان ضمن المنطقة الجمالي اظهرت ضعف في ثبات اللون بعد التعتيق j bagh college dentistry vol. 30(4), december 2018 the accuracy of the accuracy of ridge mapping procedure in determining the alveolar ridge width athraa a ahmed b.d.s. (1) salwan y. bede b.d.s., f.i.b.m.s. (2) abstract background: post-extraction alveolar ridge resorption is unavoidable phenomenon ending with insufficient ridge width. measuring the physical dimensions of the available bone before implant surgery is an important aspect of diagnosis and treatment planning. bone height can be calculated from radiographs, while bucco-lingual ridge width can be measured by conventional tomography, ct scanning and ridge mapping. radiographic techniques have certain disadvantages. therefore the ridge mapping technique was used as an option for determining alveolar ridge width. the purpose of this study was to compare the validity of alveolar ridge width measurements obtained with ridge mapping technique before surgical flap reflection against direct caliper measurement following surgical exposure of the bone. materials and methods: this prospective observational clinical study included 21 patients; 9 males (42.9%) and 12 females (57.1%) with mean age of 40.8. a vacuum formed acrylic stent was fabricated for each subject. the stent provided two buccal/lingual pairs of consistent measurement points to provide a reference of measurement for each implant site located 3 and 6 mm from the crest of alveolar soft tissue. measurements (n=216) were made at 54 implant sites, the measurements obtained from the two techniques were compared and then accuracy of these methods was assessed. the mean, standard deviation, standard error of mean were calculated and subjected to statistical analysis using student’s unpaired ttest, values <0.05 were considered statistically significant. results: there was no statistically significant difference between ridge mapping technique and intra-operative measurement in determining alveolar ridge width. conclusion: the ridge mapping technique is a useful method in determining alveolar ridge width for its exactitude, low cost, the immediate result and no need of radiation. keywords: alveolar ridge width, ridge mapping. (received: 10/9/2018; accepted: 1/10/2018) introduction nowadays, dental implants (dis) are a reliable treatment to replace lost teeth. however, placing di is not an isolated event; it is the result of a cautious pre-surgical planning to fulfill the esthetic and functional expectations of patients. assessment of the bucco-lingual dimension of the osseous ridge is needed for proper treatment planning. (1) conventional and computerized tomographic imaging modalities have a significant advantage in that bucco-lingual imaging is possible. (2, 3) on the other hand, in a way to overcome conventional radiographic limitations, some clinical methods have been suggested to measure transversal alveolar bone like ridge mapping (rm) technique. this technique involves penetrating the buccal and lingual mucosa down to the alveolar bone (following the administration of local anesthetic) with calipers designed for this purpose. the pointed tips of the instrument penetrate the buccal and lingual soft tissue layers and measure the bucco-lingual width of the underlying bone. a series of measurements of the proposed implant site can be made prior to reflection of a mucoperiosteal flap. this technique has been advocated by wilson (4) and traxler et al. (5) as a convenient and reliable method for assessing the suitability of potential implant sites. this procedure is performed chair-side and provides instant information. the direct caliper measurement following surgical exposure of alveolar bone of the ridge gives the most accurate measurement. (6, 7) the aim of this study is to determine the accuracy of ridge mapping technique by comparing the measurements obtained by ridge mapping with direct caliper measurements of the alveolar ridge bone width after surgical exposure. 24 (1)al ramadi specialized dental center, al anbar province, iraq. (2)bds, fibms, assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. j bagh college dentistry vol. 30(4), december 2018 the accuracy of figure 1: pre-operative ridge mapping materials and methods this prospective observational study included 21 patients, who attended the department of oral and maxillofacial surgery at the college of dentistry, university of baghdad, for dental implant treatment to replace single or multiple missing teeth during the period extending from november 2017 to august 2018. the inclusion criteria were: 1) patients ≥ 18 years of age including both genders presenting with single or multiple missing teeth in the maxillary and mandibular arches for at least 6 months after extraction (delayed implant placement protocol) and good oral hygiene. 2) patients with no history of any systemic disease that could interfere with normal healing or inability to withstand surgery such as uncontrolled diabetes mellitus, bleeding disorders or history of chemotherapy or radiotherapy for the head and neck region. the exclusion criteria included: 1) presence of acute/chronic infection or local pathological condition in the proposed implant zone. 2) parafunctional habits such as severe bruxism and clenching. 3) patients with limited mouth opening to a degree that precludes easy handling and instrumentation. every patient was informed about the procedures and the nature of the research, and those who agreed to participate signed an informed consent. the process started with an impression taken using condensation silicone (heavy body) impression material to form the diagnostic cast. the proposed implant sites and distribution were carefully evaluated on the cast and marked as reference points on the crest of the ridge in reference to the adjacent teeth, then 2 points were marked on the labial and palatal/lingual aspects of the ridge; the first point (point 1) at 3 mm from the reference point and the second point (point 2) at 6 mm. the surgical stent was fabricated on the diagnostic cast using vacuum former and biostar acrylic sheet 2.0 mm thickness covering reference points, points 1, points 2 and a few adjacent teeth. the points 1 and 2 were visible via the stent through the transparent acrylic resin material, then they were transferred to the stent by drilling guide holes large enough to accommodate the bone caliper tips. after administration of local anesthesia the first clinical measurements were done by sterile bone caliper, the surgical stent was immersed in an antiseptic povidone-iodine solution and was placed in the area to be measured; the tips of the bone caliper were inserted into the guide holes, penetrating through the soft tissue until there was contact with bone and the measurements were recorded in millimeters, (fig.1) after ridge mapping the stent was removed from the patient's mouth and returned into antiseptic povidone-iodine solution, then a three-sided mucoperiosteal flap consisting of a mid-crestal incision in addition to two vertical releasing incisions reflected. after flap reflection and exposure of the alveolar bone, the stent was relocated and the ridge width was measured directly on the exposed bone at the guide holes using the ridge mapping caliper device as described previously. the surgical stent was removed and the implant site preparation and installation of dental implants proceeded as per the manufacturer instructions. all the reading of alveolar ridge width obtained from the ridge mapping and direct caliper measurement were then tabulated and compared. descriptive statistical analysis included calculation of mean, standard deviation and standard error of mean and inferential analysis included using student t-test for two independent means. results twenty-one patients with a mean age (± sd) of 40.8 (±16.7) years participated in this study and received 54 dental implants, they consisted of 9 males (42.9%) and 12 females (57.1%). according to the results obtained from 216 measurements that were made at the implant placement sites, the mean ± sd of the alveolar ridge width for point 1 that was obtained from ridge mapping technique (pre-operative measurement) and intra-operative measurement after alveolar bone exposure was 0.333±0.752 25 j bagh college dentistry vol. 30(4), december 2018 the accuracy of mm and 0.630±1.248 mm respectively and 3.833±0.927 mm and 4.019±1.107 mm respectively for point 2. the differences between the two measurements at both points were statistically not significant, as shown in table 1. table 1: descriptive and inferential analysis of ridge mapping (pre-operative) and direct caliper measurement (intra-operative) at point 1 and point 2 s.d. = standard deviation. s.e. = standard error. min. = minimum. max. = maximum. n.s. =not significant. discussion in all phases of clinical dentistry, careful planning and diagnosis result in a more predictable outcome. (8) the placement of dental implants requires meticulous planning and careful surgical procedures. the contour of the residual bone must be evaluated prior to implant placement in order to assure proper implant positioning. (9) the measuring of ridge width can be accomplished using ridge-mapping calipers. the ridge-mapping procedure has the advantage of being simple to use and avoids exposure of the patient to radiation. the results obtained from this study support the use of ridge-mapping procedure for the evaluation of alveolar ridge width, which is in keeping with wilson (4) in 1989 and traxler et al. (5) in 1992, who suggested that ridge mapping is a convenient and reliable method for assessing suitability of potential implant sites. ten bruggenkate et al. in 1994 (6) using another ridge-mapping instrument in 60 subjects and 176 maxillary implant sites, compared the preoperative measurements (ridge mapping) to measurements following mucoperiosteal flap reflection (direct caliper measurements) and demonstrated that there was no significant difference between the two methods, without the use of any stent to identify the measurement locations. chen et al., in their study in 2008 (10), made a similar observation. other studies, however, reported different results; perez et al. (11) found an average of 3.6 ± 1 mm less than that obtained by direct measurement, they explained this difference by the fact that the application of excessive pressure when caliper points passed through soft tissue and bone could lead to perforation of the cortical bone and underestimation of the actual ridge width. allen and smith (7) reported a significant difference between the two methods and they observed a notable tendency to overestimate the bone width, probably due to the fact that the caliper may not completely penetrate the overlying mucosa down to bone, such a problem can arise if the overlying mucosa is particularly thick. they also maintained that underestimation of bone width may be caused by squeezing the beaks of the caliper too tightly, as the bone in this area is markedly cancellous, excessive pressure on the caliper may cause the beaks to penetrate through the outer cortical layer of bone. some observations were made in this study that may limit the benefits of rm; the presence of a dehiscence in the alveolar ridge, which was observed following flap reflection, most measurements that were made at points 1 recorded 0 mm, some difficulty was encountered in fitting the palatal aspect of the stent following mucoperiosteal flap reflection and in measuring of the mandibular alveolar ridge because of straight shank of ridge mapping device. the main limitation of this study is its small sample size, however it can be concluded that ridge mapping technique proved to be reliable method to detect the alveolar ridge width. references 1. simon bi, von hagen s, deasy mj, faldu m, resnansky d. changes in alveolar bone height and width following ridge augmentation using bone graft and membranes. j periodontol 2000; 71: 1774-1791. 2. eckerdal, o. & kvint, s. presurgical planning for osseointegrated implants in the maxilla. int j oral maxillofac surg 1986; 15: 722-726. 3. schwarz, m., rothman, s.l., chafetz, n. & rhodes, m. computed tomography in dental implant surgery. dent. clin. north am. 1989; 33: 557-597. preoperat ive point 1 intraoperat ive point 1 preoperat ive point 2 intraoperat ive point 2 no. of measurem ents 54 54 54 54 mean 0.333 0.630 3.833 4.019 sd 0.752 1.248 0.927 1.107 se 0.102 0.170 0.126 0.151 min 0.000 0.000 2.000 1.000 max 4.000 4.000 5.000 6.000 t-test 1.494 0.943 p-value 0.138 (n.s) 0.348 (n.s) 26 j bagh college dentistry vol. 30(4), december 2018 the accuracy of 4. wilson, d.j. ridge mapping for determination of alveolar ridge width. int j oral maxillofac implants 1989; 4: 41-43. 5. traxler, m., ulm, c., solar, p. & lill, w. sonographic measurement versus mapping for determination of residual ridge width. j prosthet dent 1992; 67: 358-361. 6. ten bruggenkate cm, de rijcke tb, kraaijenhagen ha, oosterbeek hs. ridge mapping. implant dent 1994; 3: 179-82. 7. allen f, smith dg. an assessment of the accuracy of ridge mapping in planning implant therapy for the anterior maxilla. clin oral implants res 2000; 11: 34-8. 8. engelman mj, sorensen ja, moy p. optimum placement of osseointegrated implants. j prosthet dent 1988; 59: 467-73. 9. boudrias p. evaluation of the osseous edentulous ridge (i.e. ridge mapping): probing technique using a measuring guide. dent chron assoc prosthodontists quebec 2003; 40: 301-2. 10. chen lc, lundgren t, hallström h, cherel f. comparison of different methods of assessing alveolar ridge dimensions prior to dental implant placement. j periodontol 2008; 79: 401-5. 11. perez la, brooks sl, wang hl, eber rm. comparison of linear tomography and direct ridge mapping for the determination of edentulous ridge dimensions in human cadavers. oral surg oral med oral pathol oral radiol endod 2005; 99: 748-54. المستخلص يعد قياس األبعاد الفيزيائية للعظام المتاحة قبل إجراء فان ارتشاف الحرف هو ظاهرة ال مفر منها وتنتهي مع عدم كفاية الحافة السنخية. عملية قلع االسنانخلفية: بعد فيي حيين يمكين قيياس عيرة حافية الشيعاعية يمكين حسياا ارتفيال العظي مين ال يور التشخيص والتخطيي للعي. .جراحة زراعة األسنان جانبًا هاًما من جوانب الحافة. وموضعة ctالمقطعيالت وير التقليدي الت وير المقطعي اللساني بواسطة-الشدق كان الغرة من هذه الدراسة هو مقارنة كخيار لتحديد عرة الحافة السنخية. تخطي الحافةان تقنيات الت وير الشعاعي لديها بعض العيوا. لذلك ت استخدام تقنية قيياس الفرجيار المبا ير بعيد تعيرة للطية مقابلصحة قياسات عرة الحافة السنخية التي ت الح ول عليها باستخدام تقنية موضعة الحافة قبل االنعكاس الجراحي العظ للتداخل الجراحي. . ت ت نيع دعامة أكريليك مكونية 4..9( بمتوس عمر ٪2..1) إناث 21و( ٪91.9ذكور ) 9 مريضا. 12هذه الدراسة السريرية المرتقبة ملت المواد واألساليب: نة السنخية.م من قمة األنسجة اللي 6و 3متسقة لتوفير مرجع للقياس لكل موقع زرل يبعد ةاللساني يةالشدق النقاط وفرت الدعامة زوجين من من فراغ لكل حالة. ت حساا متوسي االنحيراف وتمت مقارنة القياسات التي ت الح ول عليها من هذين األسلوبين وت تقيي دقة هذه األساليب. موقع زرل 19ت إجراء القياسات في تعتبر ذات داللة إح ائية. 1...المفرد وكانت القي > student’s ttestالمعياري الخطأ المعياري للوس وتعرة لتحليل إح ائي باستخدام اختبار العملية في تحديد عرة الحافة السنخية.خ.ل الحافة و قياسات تخطي النتائج: ل يكن هناك فروق ذات داللة إح ائية بين تقنية ة والتكلفة المنخفضة والنتيجة الفورية دون الحاجة لإل عال.فة السنخية من أجل الدقاالحافة هي طريقة مفيدة في تحديد عرة الح تخطي : تقنية ستنتا اال الحافة. تخطي كلمات البحث: عرة الحافة السنخية 27 j bagh college dentistry vol. 30(3), september 2018 evaluation of 17 evaluation of anti-centromere antibodies, anti-ssa and anti-ssb in serum and saliva of patients with systemic sclerosis mohassad h al-mudhaffar b.d.s, m.sc. (1) taghreed f. zaidan b.d.s, m.sc., ph.d. (2) abstract background: systemic sclerosis (ssc) is a chronic autoimmune illness, which is consider by three main features: sclerotic changes in the skin and internal organs, vasculopathy of small blood vessels, particular autoantibodies (1). the most important autoantibodies appeared significantly in ssc patients are anti-topoisomerase i autoantibody (scl-70), anticentromere autoantibody (aca), and anti-rna polymerase iii autoantibody (rnap3) (2). anti-centromere antibodies (aca) are infrequent in rheumatic conditions and in healthy persons but occur commonly in limited systemic sclerosis (crest syndrome), and rarely appeared in the diffuse form of systemic sclerosis (3). anti-ro/ssa and antila/ssb, antibodies directed against ro/la ribonucleoprotein complexes, can serve as a diagnostic hallmark of autoimmune disease specially sjogren’s syndrome (4). materials and methods: this study was carried out during the period from the middle of november 2015 until the end of november 2016 in baghdad city. the sample of this study was divided into two groups : forty systemic sclerosis patients: those patients were treated at rheumatology department in baghdad teaching hospital in baghdad city as well as forty healthy control subjects, age matched with no signs and symptoms of any systemic diseases. results: the serum anti-ssa in ssc patient was significant increased as well as the salivary anti-ssa in ssc patient was highly significantly increased than in the control subjects by using t-test. the present study found that there no statically difference in salivary aca, anti-ssb and serum anti-ssb while serum aca was significantly increased. conclusions: autoantibodies play a role in pathogenesis of ssc patients represented by increased serum (aca and anti-ssa) that it considered reliable indicator for ssc patients while unpredicted marker in saliva except anti-ssa. antila/ssb is unreliable marker in both serum and saliva ssc patients. the presence of anti-ro/ssa antibodies in serum and saliva of ssc patient has been predictive marker for ssc overlapped sjogren’s syndrome. key word: systemic sclerosis. aca, anti-ssa and anti-ssb. . (j bagh coll dentistry 2018; 30(3): 17-20) introduction systemic sclerosis (ssc) is a chronic multiorgan complex autoimmune disease that causing the own tissue strike dawn by body’s immune system; ssc was classified into two main types, according to the extent of skin involvement (5). 1. limited cutaneous systemic sclerosis (lcssc) 2. diffuse cutaneous systemic sclerosis (dcssc) leroy et al., 1988 classified systemic sclerosis in subdivision as firstly limited type ssc –when the skin involved up to the elbow and knees with the face – and in diffuse form ssc – with skin envelopment also including the trunk as shown in table 1 (6). there are three main features of ssc, which have been integrated by 2013 ssc criteria but not all patient come with these features: autoantibodies, vascular injury, and finally with fibrotic changes. raynaud phenomenon (rp) is a feature included in ssc criteria if distinguished from other disease associated with rp, but because ssc without rp is so infrequent, therefore rp increased statistical value to these criteria (7). there are some features associated with ssc patients such as sclerodactly, anticentromere antibodies, scl-70, raynaud phenomena, dilated nailfold capillaries, dysphagia, and calcinosis. university of baghdad. however, a patient with only sclerodactyly, gastroesophageal reflux disease, dysphagia, rna polymerase iii and renal crisis would not encounter either usual of ssc criteria, but as soon as the scleroderma advanced beyond the fingers, the patient would fulfil both classifications (7). changes caused by progressive systemic sclerosis extent from mouth to anus. in the mouth, the changes are in the following (8). microstomia (decreased mouth opening). it is produced due to skin sclerosis on the face that stretches the look of “the bird’s face” which is one of the most characteristic features of patients with progressive systemic sclerosis. this may interfere considerably with eating, speaking, oral hygiene measures, and dental treatment, thus deteriorating the quality of life of these subjects (9). fibrosis of salivary glands may related to dryness in mouth of ssc patient (xerostomia). 1. telangiectasia. 2. trigeminal neuralgia. 3. histological alterations are due to fibrotic changes in lamina propria, layer of submucosa, and muscular layer. each portion of alimentary canal that containing smooth muscle can be attacked by progressive systemic sclerosis. 4. blanching of the mucosa involving buccal mucosa, soft and hard palate (10). (1) college of dentistry, university of kufa, iraq (2) professor, department oral diagnosis, college of dentistry, https://en.wikipedia.org/wiki/centromere https://en.wikipedia.org/wiki/crest_syndrome https://en.wikipedia.org/wiki/crest_syndrome j bagh college dentistry vol. 30(3), september 2018 evaluation of 18 5. tongue rigidity and limited movement of tongue as shown in figure (10). anti-ro/ssa and antila/ssb, antibodies directed against ro/la ribonucleoprotein complexes, can serve as a diagnostic hallmark of autoaimmune disease especially sjogren’s syndrome. depending on the method applied for their identification, anti-ro/ssa and anti-la/ssb antibodies detected in approximately 50 to 70% of pss patients (4). it is becoming increasingly apparent to investigators and clinicians in a variety of disciplines that saliva has many diagnostic uses and is especially valuable in the young, old and in large scale screening and epidemiologic studies. it has found that saliva was used as a diagnostic aid in an increasing number of systemic diseases that can affect salivary gland function and composition. therefore, a correct diagnosis will always require a full clinical and laboratory investigation. however, sialochemistry is a useful means of chronologically, monitoring qualitative and quantitative changes (11). table 1: classification of scleroderma (6). localized scleroderma (localized cutaneous fibrosis)  limited or generalized morphea: circumscribed patches of sclerosis  linear scleroderma: linear lesions seen in childhood  encoup de sabre: linear lesions of the scalp or face systemic scleroderma (cutaneous and noncutaneous involvement)  limited cutaneous systemic sclerosis (lcssc), formerly called crest syndrome (calcinosis of the digits, raynaud's phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasias)  diffuse cutaneous systemic sclerosis (dcssc): sclerosis of proximal extremities, trunk, and face  systemic sclerosis sine scleroderma (ssssc): organ fibrosis only; no skin thickening. materials and methods this study carried out during the period from the middle of november 2015 until the end of november 2016 in baghdad city, the sample of this study divided into two groups: 1forty systemic sclerosis patients: those patients treated at rheumatology department in bagdad teaching hospital in baghdad city. 2forty healthy control subjects, age matched with no signs and symptoms of any systemic diseases. all patients diagnosed by a rheumatology specialist as systemic sclerosis patients depending on the criteria of the acr, 2013. each subject was informed about the study purpose and her consent was obtained. case sheet contained the information about name, gender, age, medical history, family history, and some oral manifestation that occurs in systemic sclerosis patients and related investigation was filled. all patients with systemic sclerosis and control subjects were examined by using dental mirror and probe with artificial light. the examination would begin in systems according to w.h.o. that started from “upper and lower lip, upper and lower sulcus, retro-molar area, upper and lower labial mucosa, buccal mucosa, then hard and soft palate, dorsal margin and inferior surface of the tongue, floor of the mouth were also examined (12). detection of oral mucosal lesions and their features such as “duration, size, clinical description, location of lesion”, and lastly the clinical diagnosis was identified. the quantitative determination of human aca (anti-centromere), human anti-ssa/ro and anti-ssb/la elisa kits used from kono biotech co. ltd company. the proposed use was for content determination in serum, plasma, cell culture supernatant, tissue homogenate and any other biological fluid. the inclusion criteria were patients with diffuse cutaneous systemic sclerosis. the exclusion criteria included: 1. limited cutaneous systemic sclerosis 2. patients previously diagnosed overlap syndrome. 3. smoking patients 4. patients with renal failures. results serum and salivary aca level: the result in the present study showed that the median and mean rank level of serum aca in ssc patients (361.59 and 49.28 ng/ml) was highly significant increased (p<0.001) than that the control subjects. the median and mean rank level of salivary aca in ssc patients were 411.19 and 41.63 ng/ml which was no significant difference (p0.05) by using mann-whitney u test than that control subjects as shown in tables 2 and 3. serum and salivary anti-ssa level: the mean level of serum anti-ssa in ssc patients (140.4 ± 22.67 ng/ml) which was significant increased (p<0.05) using t-test than that control subjects (113.1 ± 18.01 ng/ml). j bagh college dentistry vol. 30(3), september 2018 evaluation of 19 the mean level of salivary anti-ssa in ssc patients (145.5 ± 19.98) which was significant increased (p<0.05) by using t-test than that control subjects (111.5 ± 15.47 ng/ml), as shown in tables 4 and 5. serum and salivary anti-ssb level: the median and mean rank level of serum anti-ssb in ssc patients (38.86 and 38.05 ng/ml) which showed no significant difference than that in the control subjects. the median and mean rank level of salivary anti-ssb in ssc patients (42.06 and 38.05 ng/ml), also showed no significant difference than that in the control subjects as in table (6 and 7). table 2: the median and mean rank difference of serum aca (ng/ml) in ssc patients. groups median mean rank p value patients 361.59 49.28 0.001 (hs) control 313.38 31.73 table 3: the median and mean rank difference of saliva aca (ng/ml) in ssc patients. groups median mean rank p value patients 411.19 41.63 0.665 (ns) control 411.31 39.38 table 4: the mean and sd of serum anti-ssa (ng/ml) in ssc patients. groups mean and sd t-test p-value patients 140.4 ± 22.67 2.569 0.011 (s) control 113.1 ± 18.01 table 5: the mean and sd of saliva anti-ssa in ssc (ng/ml) patients. groups mean and sd t-test p-value patients 145.5 ± 19.98 3.459 0.014 (s) control 111.5 ± 15.47 table 6: the median and mean rank difference of serum anti-ssb (ng/ml) in ssc patients. groups median mean rank p-value patients 38.86 38.05 0.346 (ns) control 40.79 42.95 table 7: the median and mean rank difference of saliva anti-ssb (ng/ml) in ssc patients. groups median mean rank p-value patients 42.06 38.05 0.364 (ns) control 42.85 42.95 discussion serum and salivary aca: the present study showed that the aca significantly increased in serum ssc patients than in the control subjects but salivary level remains not significant than in the control subjects. chung et al. stated that aca significantly increased in serum ssc patients (13). anti-centromere antibodies are highly specific for scleroderma with limited cutaneous type “crest syndrome”; therefore, the patients with primary raynaud’s phenomenon alone or with other connective tissue diseases can develop aca autoantibodies (14-15). there are no previous studies showed that the level of aca in saliva ssc patients. serum and salivary anti ro/ssa and anti la/ssb: in present study, serum and salivary antiro/ssa were significantly increased. in present study, serum anti-ro/ssa was significantly increased. this came into agreement (16-19). in previous great, multicenter cohort study, found that anti-ro52 antibodies detected in “20% of 963” in serum patients, making them the second most common autoantibodies in systemic sclerosis, as well as overlapped with other disease specific auto reactive antibodies (17). anti-ro antibodies found also in 3–11% of serum patients with ssc (18). brouwer et al. described the occurrence of anti-ro52 antibodies in “dermatomyositis /polymyositis and scleroderma” (16). anti-ro/ssa and anti-la/ssb antibodies are commonly in systemic lupus erythromatosis and sjögren’s syndrome patients and their presence is one of the criteria for the diagnosis and classification of sjögren’s syndrome. they are rare in the general population and in diseases other than sjögren’s syndrome and systemic lupus erythromatosis, although they can be detected in scleroderma, polymyositis, mixed connective tissue disease, and rheumatoid arthritis (19( in present study, serum and salivary antila/ssb antibodies were non-significant difference than in the control subjects. in present study, serum anti-la/ssb antibodies was non-significant difference than in the control subjects. disagree with a previous study (20). there are no previous studies showed that the level of anti-la/ssb antibodies in saliva patients with ssc but previous studies on other autoimmune disease as sjogren’s syndrome detected anti-la/ssb antibodies in saliva (21, 22). j bagh college dentistry vol. 30(3), september 2018 evaluation of 20 the presence of anti-la/ssb antibodies in saliva has been predictive marker for sjogren’s syndrome as well as in the control of disease progression. (22). the present study was suggested that sicca syndrome in ssc predictive that patients overlapped with sjogren's syndrome. this finding was in agreement with previous reported studies (23-25). conclusion 1. the levels of aca, and anti-ssa significant increased in serum of ssc patients. 2. the levels of anti-ssa significant increased in saliva of ssc patients and predicted to ssc overlap sjogren’s syndrome. references 1. ismet hb, kryeziu a, sherifi f. oral manifestations of systemic sclerosis and correlation with antitopoisomerase i antibodies (scl-70). med arh. 2015; 69(3): 153-6. 2. steen vd. autoantibodies in systemic sclerosis. semin arthritis rheum 2005; 35(1): 35-42. 3. imboden jb, hellmann db, stone jh. current rheumatology diagnosis and treatment. 2nd ed. new york: lange medical books/mcgraw-hill. 2007 4. routsias jg, tzioufas ag. sjogren’s syndrome—study of autoantigens and autoantibodies. clin revi allerg immunol 2007; 32(3): 238–51. 5. khanna d, denton cp. evidence-based management of rapidly progressing systemic sclerosis. best pract res clin rheumatol. 2010; 24(3): 387-400. 6. leroy ec, black c, fleischmajer r, et al. scleroderma (systemic sclerosis): classification, subsets and pathogenesis. j rheumatol 1988; 15(2): 202-5. 7. van den hoogen f, khanna d, fransen j, et al. classification criteria for systemic sclerosis: an american college of rheumatology/european league against rheumatism collaborative initiative. arthritis rheum 2013; 65(11): 2737-47. 8. bajraktari ih, kryeziu a, sherifi f, bajraktari h, lahu a, bajraktari g. oral manifestations of systemic sclerosis and correlation with anti-topoisomerase i antibodies (scl-70). med arh. 2015; 69(3): 153-6. 9. wada t, ram s. limited mouth opening secondary to diffuse systemic sclerosis. case reports dentist. 2013; 2013, 3 pages. 10. singh p, kapoor s, bither s. oral manifestations in progressive systemic sclerosis: case report. j dentist oral hyg 2011; 3(7): 89-94. 11. w.h.o. oral health survey, basic methods. 4th ed. world health organization, geneva, switzerland 1987. 12. sunil r, nupur p, kishore ma, alok a. sialochemistry – an emerging oral diagnostic tool. j dent sci oral rehab. 2013; 1-3. 13. chung l, lin j, furst de. systemic and localized scleroderma. clin dermatol 2006; 24:374-92. 14. schachna l, wigley fm, morris s, et al. recognition of granzyme b-generated autoantigen fragments in scleroderma patients with ischemic digital loss. arthritis rheum 2002; 46:1873-84. 15. careta mf, romiti r. localized scleroderma: clinical spectrum and therapeutic update. an bras dermatol. 2015; 90 (1):62-73. 16. brouwer r, hengstman gj, vree egberts w, ehrfeld h, bozic b, ghirardello a, et al. autoantibody profiles in the sera of european patients with myositis. ann rheum dis 2001; 60:116-23. 17. hudson m, pope j, mahler m, tatibouet s, et al. clinical significance of antibodies to ro52/trim21 in systemic sclerosis. arthr res therap. 2012; 14: 50. 18. yoshimi r, ueda a, ozato k, ishigatsubo y. clinical and pathological roles of ro/ssa autoantibody. clinical and developmental immunology 2012; 2012, 12 pages. 19. birtane m. diagnostic role of anti-nuclear antibodies in rheumatic diseases turk. j rheumatol 2012; 27(2): 79-89. 20. kobak s, oksel f, aksu k, kabasakal y. the frequency of sicca symptoms and sjogren’s syndrome in patients with systemic sclerosis. int j rheum dis. 2013; 16:88–92. 21. margaix-muñoz m, bagán jv, poveda r, jiménez y, sarrión g. sjögren’s syndrome of the oral cavity. review and update. med oral patol oral cir bucal. 2009; 14: 325-30. 22. deepa tn. saliva as a potential diagnostic tool. indian j med sci. 2010; 64(7): 293-306. 23. avouac j, sordet c, depinay c, ardizonne m, et al. systemic sclerosis–associated sjogren’s syndrome and relationship to the limited cutaneous subtype. arthrit rheum 2006; 54(7): 2243-9. 24. balbir-gurman a, braun-moscovici y. scleroderma overlap syndrome. imaj. 2011; 13: 14-20. 26. savarino e, furnari m, bortoli n. gastrointestinal involvement in systemic sclerosis. presse med. 2014; 43: 279-91. 25. baron m, hudson m, tatibouet s, et al. the canadian systemic sclerosis oral health study iii: relationship between disease characteristics and oro-facial manifestations in systemic sclerosis. arthritis care res 2015; 67(5): 681-90. http://www.ncbi.nlm.nih.gov/pubmed/?term=denton%20cp%5bauthor%5d&cauthor=true&cauthor_uid=20534372 http://www.ncbi.nlm.nih.gov/pubmed/?term=leroy%20ec%5bauthor%5d&cauthor=true&cauthor_uid=3361530 http://www.ncbi.nlm.nih.gov/pubmed/?term=black%20c%5bauthor%5d&cauthor=true&cauthor_uid=3361530 http://www.ncbi.nlm.nih.gov/pubmed/?term=fleischmajer%20r%5bauthor%5d&cauthor=true&cauthor_uid=3361530 dunia f.doc j bagh college dentistry vol. 25(4), december 2013 the effects of unilateral pedodontics, orthodontics and preventive dentistry95 the effects of unilateral premature loss of maxillary primary molars on the dental arch dimensions dunia a. al-dulayme, b.d.s., m.sc. (1) abstract background: the aim of the study was to evaluate the amount of changes in the horizontal and vertical maxillary arch dimensions measurements following the premature loss of primary molars. materials and methods: the sample consist of (50) children with unilateral prematurely extracted either first or second primary molars at the mixed dentition stage. results and conclusions: results shows that there was an increase in the vertical incisor to canine distance (a) with both premature loss of first & second primary molars due to distal movement of primary canines and at the same time there were a significant loss of space in the extraction space with premature loss of second primary molar due to a mesial movement of maxillary first permanent molars which at the same time tip lingually and this is clear obvious from the decrease in the inter-molars distances horizontally. keywords: maxillary arch dimensions, premature loss, space closure. (j bagh coll dentistry 2013; 25(4):95-99). introduction one of the important services that the general dentist and the pedodontist can render for young patient is that of maintaining the arch length prior to the eruption of permanent teeth (1), the various functions of primary dentition are to provide mastication as well as to maintain the occlusion and space for the permanent teeth ,exfoliation of primary teeth and eruption of permanent successors is a normal physiological process ,when this normal process disrupted due to premature extraction of deciduous teeth a series of changes observed in the dental arches (2,3). the majority of authors agree that in most cases the premature extraction of primary molars will cause crowding associated with either rotation, tipping or bodily movement of teeth (3-6). some authors reported a greater proportional space loss resulting from mesial migration of the posterior teeth (7). other researchers have reported somewhat different results, such as anterior teeth moving toward distal teeth with the extraction site separating them, and teeth adjacent to the extraction site moving in both directions toward the extraction space (6,8) ,others conducted a longitudinal review of 13 cases of premature loss of primary maxillary molars; the results showed a reduction in arch length and a mesial displacement of the permanent canine, which eventually became virtually blocked out (9).while another studies measured the amount of arch length changes following premature loss of primary molars unilaterally for both arches they found that a reduction in the dental arch length was observed both in the maxilla and mandible at the molar region and an increase in arch length in the canine region in the mandible (3) . (1)assistant lecturer. department of pedodontics, orthodontics and preventive dentistry. college of dentistry, almustansiria university. al-dulayme (10) measured the vertical and horizontal maxillary arch dimensions in a sample of iraqi children with full dentition without premature loss of primary teeth for the same age group of the present study at the mixed dentition stage ,the study concluded that the mean values of the maxillary arch widths are as follows (ic) which represent the inter-canine width were (33.98)mm and the (mb), (ml), (db) and (dl) distances ,which represent the inter –molars widths were (50.79)mm, (40.66)mm, (52.68)mm and (41.99)mm respectively ,these measurements (widths) estimate the relative position of maxillary primary canines and the maxillary first permanent molars horizontally. while the mean values of the maxillary arch lengths at a,b,c and d were found to be (9.13)mm, (19.31)mm,( 28.07)mm and (38.11)mm respectively, these measurements estimate the length of the maxillary arch antero-posteriorly ,where (a) represent the distance between the contact points of the maxillary permanent central incisors to the line tangent to the cusp tip of the maxillary primary canines, while (b,c,d) represent the distance from the midline of permanent central incisors to the line tangent of distal contact areas of primary first and second molars and the first permanent molars respectively.. the present study was carried out for iraqi children at (8-9) years of age to measure the amount of changes in the maxillary horizontal and vertical dental arch dimensions due to the premature unilateral extraction of first or second primary molars during the mixed dentition stage. materials and methods the sample of the present study consists of 50 iraqi healthy children ranging in age between 8-9 years, at the mixed dentition stage, belonging to a mixed socioeconomic status selected from j bagh college dentistry vol. 25(4), december 2013 the effects of unilateral pedodontics, orthodontics and preventive dentistry96 different primary schools from baghdad city. the children divided into two groups: group (1): it included 25 children (13 males and 12 females) have unilateral premature loss of maxillary first primary molars figure (1). group (2): it included 25 children (13 males and 12 females) have unilateral premature loss of maxillary second primary molars figure (2). both groups had the period of absence of prematurely extracted primary molars between 612 months. the remaining dentition was healthy with no extensive caries or malformation and had no history of space maintainer therapy or orthodontic treatment. dental study models were prepared by taking alginate hydrocolloid impressions for each child with perforated metal trays, pouring it with dental stone according to the manufacturing instructions, then for every dental cast a proper plaster base was made and trimmed then labeled with certain number (11). study models measurements figures (3) a and (4) a shows the maxillary dental arch widths" horizontal" measurements which included (10): 1ic: inter-canine distance which extends between the cusp tips of right and left canine (and / or the centers of the facets of the weared primary canines). 2im: inter-molars distances which are represented by 4 distances: i. mb: the distance between the mesiobuccal cusp tips of right and left maxillary first permanent molars. ii. ml: the distance between the mesiolingual cusp tips of right and left maxillary first permanent molars. iii. db: the distance between the distobuccal cusp tips of right and left maxillary first permanent molars. iv. dl: the distance between the distolingual cusp tips of right and left maxillary first permanent molars. while figures (3) b and (4) b shows the maxillary dental arch length" vertical" measurements include four distances (10) which are: 1a: the distance between the contact points of the maxillary permanent central incisors to the line tangent to the cusp tip of the maxillary primary canines (or when worn, to the centers of resulting facets). 2b: the distance between the contact points of the maxillary permanent central incisors to the line tangent to the distal surfaces of the maxillary primary first molars. 3c: the distance between the contact points of the maxillary permanent central incisors to the line tangent to the distal surfaces of the maxillary primary second molars. 4d: the distance between the contact points of the maxillary permanent central incisors to the line tangent to the distal surfaces of the maxillary first permanent molars. each of these landmarks were marked on the study casts by a sharp lead pencil to facilitate accurate recognition, then the occlusal surface of study casts were facing the glass window of the scanner directly, then accurate & exact image of the casts were saved and transferred to the auto sketch program on pentium 4 computer according to the instruction read from that software program, the auto sketch (germany ) software provides a complete set of cad tools for creating professional-quality precision drawing, such software program were accurately used in many other dental measurements (12). later on, the results obtained from the present study were compared with the results of previous iraqi study (10) because the age of the studied sample was the same and no other study has been done in iraq to measure such dimensions. results all the variables of the maxillary dental arch dimensions for the studied sample for both genders were subjected to the descriptive statistics (mean, minimum, maximum, range and standard deviation). table (1) demonstrates the maxillary dental arch dimensions for group (1), which shows that the mean values of the maxillary dental arch widths at ic were (33.67)mm and the mb, ml, db and dl distances were (51.33)mm, (40.72)mm, (53.44)mm and (42.99)mm respectively ,while the maxillary dental arch lengths measurements for group (1)shows that the mean values at a ,c and d were (10.23)mm, (28.46)mm and (38.86)mm respectively. the (b) distance has been excluded because of the loss first primary molars. two tailed t-test was applied to test the significance difference between the means of the groups, table (2) shows the mean values of the maxillary arch dimensions of the group (1) and its comparison with the control group (10). table (3) demonstrates the maxillary dental arch dimensions for group (2), which shows that the mean values of the maxillary dental arch widths at ic were (33.05)mm and the mb, ml, db and dl distances were (48.41)mm, (37.77)mm, (49.49)mm and (40.27)mm respectively. while the maxillary dental arch j bagh college dentistry vol. 25(4), december 2013 the effects of unilateral pedodontics, orthodontics and preventive dentistry97 lengths measurements for group (2) shows that the mean values at a,b and d were(10.29)mm, (20.59)mm, and (37.80) respectively, the (c) distance has been excluded because of the loss second primary molars . two tailed t-test was applied to test the significance difference between the means of the groups, table (4) shows the mean values of the maxillary arch dimensions of the group (2) and its comparison with the control group (10). discussion the actual mechanism of tooth drifting is not clearly understood .the factors which may produce this drifting are occlusal force, ligament contraction and soft tissue pressure (13). in the present study , a general look to tables (1) and (2) indicate that the arch lengths and widths of maxillary arches that undergoes unilateral premature loss of first primary molars ,is not so much different from the control group which has been elected by previous studies (10),nevertheless when we apply the t-test between them it shows no significant difference in all the parameters except at( a) length ,this give us a clue that the primary canines have been moved distally in anteroposterior direction only i.e. toward the space and this movement occur may be due to a pressure exerted from the permanent incisors (46,8,14,15), or the primary canines themselves tend to encroach the space distally without any change in the intercanine width and this disagree with other studies (3,16,17), our findings will lead us to many facts; 1-intercanine width sustained normal when first primary molar prematurely extracted and this information is so valid to pedodontist and orthodontist during their routine work. 2the significant difference in (a) length while there is no significant difference in the (c) length demonstrate that the second primary molars undergoes a very minimal tooth movement mesially when compared with the distal movement of the primary canines which mean that the extraction spaces has been lost by the distal migration of primary canines rather than the mesial movements of second primary molars. in case of premature loss of primary second molars, most studies agreed that the loss of primary second molars will result in great space loss closure than any primary tooth, this makes the maxillary primary second molars the poorest choice in the mouth for premature extraction (1722). from the results obtained in table (3) and (4) together shows that the maxillary arch dimensions after the unilateral premature loss of second primary molars, there was also an increase in a distance owing to the distal movement of primary canines in spite of they are adjacent to the first primary molars and this is because that the primary first molars also have moved distally and bucally due to an increase in b length from 19.32 to 20.59 , further more the( ic) distance was decreased although of non significant relation but still give us a fact that there was a loss or change in contact area between the primary canines and the first primary molars ,because each one of them have moved opposite to each other horizontally but at the same time they move distally together. these facts come in accordance with northway et al. (5). the main goal in this research is the relative position of the maxillary permanent first molars after the premature loss of each of the primary molars, in which we design to take 6 parameters, for this reason these parameter are illustrated in table (3) and they are (c) and (d) ;both are vertical dimensions that measure the relative position the maxillary permanent first molars antero-posteriorly (length) in the arch. while the (mb), (ml), (db) and (dl) all of them are horizontal dimensions that measure the relative position of the maxillary permanent first molars laterally or horizontally. again if we look carefully to table (1) & (2) we discover that there were no or very minimal decrease or increase in both vertical and horizontal distances that express the point to the relative position of the permanent first molars and such minimal changes actually has very little or no significant effect clinically ,since they were not exceeding the lee way space (6),this fact demonstrate that premature extraction of first primary molars are of less effect on the future position of the maxillary permanent first molars and this in accordance with many studies (5,8,16,18,19-22), and give us a fact that extraction of first primary molars when its compulsory done, needs a little concern as much as to construct a space maintainer at this age group 8-9 years. generally, but for each clinical case one should think in a different manner, so careful consideration of many factors is required when deciding whether space maintenance is indicated, radiographs and space analysis can be helpful. finally if we look at the results shown in table (3) & (4), the (a & b) vertical length are increased and significantly the a length where there is a premature loss of second primary molars which indicate that there was a distal movement of primary canines and first primary molars toward the extraction space at the same time there was a decrease in mb,db, & dl length significantly and highly significant j bagh college dentistry vol. 25(4), december 2013 the effects of unilateral pedodontics, orthodontics and preventive dentistry98 difference when ml length decrease , indicating that the maxillary permanent first molars have moved mesially toward the space and at the same time moved lingually (19,22), which give us a fact that regaining the lost space does not need a simple single direction of tooth movement but a multiple types of tooth movements to reestablish the original position of the tooth. thus the lingual movement in addition to mesial movement of the maxillary permanent first molars toward the extraction space is the new discovery of our research because our measurement were in a two dimensional figure. as conclusions, premature loss of primary molars results in a change in arch length as follows: 1premature loss of first primary molar lead to increase in canine incisor distance i.e. vertical (a) length and at the same time a minimal change in intermolar distances. 2premature loss of second primary molar there will be also increase in (a) and (b) distances. and at the same time the first permanent molars drift mesially and tipped lingually as observed from the change in the size of extraction site and the horizontal inter molar disturbances. references 1. david bl. space maintenance. j dentistry for children 1959; 37:130-44. 2. salzmann ja. a study of orthodontic & facial changes and effects on dentition attending the loss of first molars in 500 adolescent. j am dent assoc dental 1938; 25: 892-5. 3. rao ak, sarkar s. changes in the arch length premature loss of deciduous molars. j indian soc pedod prev dent 1999; 17(1): 28-32. 4. seward fs. natural closure of deciduous molar extraction spaces. angle orthod 1965; 35(1): 85-94. 5. northway wm, wainright rl, demirjian a. effect of premature loss of deciduous molars. angle orthod 1984; 54(4): 295-329. 6. yai tl, wen hl, yng jl. immediate and six-month space changes after premature loss of a primary maxillary first molar. jada 2007; 138: 362-86. 7. love wd, adams bl. tooth movement into edentulous areas. j prosthet dent 1971; 25(3): 2718. 8. tatjana t, zorica b, julia r. the effects of early loss of lateral teeth. medicine & biology 2008; 15(2): 68-73. 9. northway wm. the not-so-harmless maxillary primary first molar extraction. jada 2000; 131: 1711-20. 10. al-dulayme da. maxillary dental arch dimensions in a sample of iraqi children at the mixed dentition stage. mdj 2009; 6(4): 349-55. 11. woodward jd, morris jc, khanz r. accuracy of stone casts produced by perforated trays and nonperforated trays. j prosth dent 1985; 53: 347. 12. al-azzawi ra. assessment of dental arch crowding by the use of two methods in iraqi youngster sample. a master thesis, college of dentistry baghdad university, 2005 13. tencate ar. oral histology, development, structure & function. 3rd ed. c.v. mosby; 1989. 14. kronfeld s. the effects of premature loss of primary teeth and sequence of eruption of permanent teeth on malocclusion. j dentistry for children 1953; 3: 2-13. 15. hoffding j, kisling e. premature loss of primary teeth, part i: its overall effect on occlusion and space in the permanent dentition. asdc j dent child 1978; 45(4): 279-83. 16. clinch m, healy mj. a longitudinal study of the results of premature extraction of deciduous teeth between 3 and 4 and 13 and 14 years of age. dent pract1959; 9:109-27. 17. owen dg. the incidence and nature of space closure following the premature extraction of deciduous teeth .a literature survey. am j orthod 1971; 59(1): 37-49. 18. unger al. incidence and effect of premature loss of deciduous teeth. int j orthod 1938; 84: 613-21. 19. liu wa. a study of the closure of space following premature loss of deciduous teeth. a master thesis, university of toronto, 1949. 20. breakspear ek. sequelae of early loss of deciduous molars. dent rec 1951; 71(7):127-30. 21. breakspear ek. further observations on early loss of deciduous molars. dent practj1961; 11:233-52. 22. hinrichsen cfl. space maintenance in pedodontics. aust dent j 1962; 7: 451-6. table 1: mean values of maxillary dental arch dimensions in millimeters for group (1) no. mean ± sd ic 25 33.67 2.05 mb 25 51.33 3.18 ml 25 40.72 2.97 db 25 53.44 3.02 dl 25 42.99 3.01 a 25 10.23 1.03 c 25 28.46 1.85 d 25 38.86 2.47 table 2: comparison of the mean values of maxillary arch dimensions for group (1) with the control group al-dulayme (10) means of group (1) p-value ic 33.98 33.67 0.57* mb 50.79 51.33 0.50* ml 40.67 40.72 0.95* db 52.69 53.44 0.33* dl 42 42.99 0.30* a 9.14 10.23 0.0009** c 28.07 28.46 0.46* d 38.11 38.86 0.26* *not significant ** significant *** highly significant j bagh college dentistry vol. 25(4), december 2013 the effects of unilateral pedodontics, orthodontics and preventive dentistry99 table 3: mean values of maxillary dental arch dimensions in millimeters for group (2) no. mean ±sd ic 25 33.05 2.45 mb 25 48.41 2.87 ml 25 37.77 2.2 db 25 49.49 7.36 dl 25 40.27 2.12 a 25 10.29 1.18 b 25 20.59 2.02 d 25 37.8 2.18 table 4: comparison of the mean values of maxillary arch dimensions for group (2) with the control group al-dulayme (10) means of group (2) p-value ic 33.98 33.05 0.14** mb 50.79 48.41 0.0031** ml 40.67 37.77 0.000*** db 52.69 49.49 0.072* dl 42 40.27 0.042** a 9.14 10.29 0.0013** b 19.32 20.59 0.063* d 38.11 37.8 0.60* * not significant ** significant *** highly significant fig. 1: group (1) first primary molar loss fig. 2: group (2) second primary molar loss fig. 3 a: horizontal arch measurements fig. 3 b: vertical arch measurements for group (1) for group (1) fig. 4 a: horizontal arch measurements fig. 4 b: vertical arch measurements for group (2) for group (2) dropbox 13 farah 69-75.pdf simplify your life 7.thaer f.doc j bagh college dentistry vol. 25(1), march 2013 the effect of curvature restorative dentistry 38 the effect of curvature angle and rotational speed on the cyclic fatigue of three types of rotary instrument (in vitro): comparative study thaer a. mukhlif, b.d.s. (1) abdul-karim j. al-azzawi, b.d.s, m.sc. (2) abstract background: the fracture of instruments within root canal during endodontic treatment is a common incidence, fracture because of fatigue through flexure occurs due to metal fatigue, this study aimed to assess the effect of curvature angle and rotational speed on the cyclic fatigue of different type of endodontic niti rotary instruments and compare among them. materials and method: three types of rotary instruments with tip size 0.25: protaper f2 (densply, malifier) revo-s su( 0.06 taper, micromega) and race system (0.06 taper, fkg, dentaire), forty file of each instrument were used within two canals with angle of curvature (40 &60 )at two speed (250&400)rpm, twelve group were formed for all instruments(total number=120),ten file for each group. the testing canals customized within stainless steel block covered with glass face, the time to fracture recorded and the mean of cycles to fracture (mcf) detected for each instrument. data were analyzed statistically by anova, lsd and independent t-test at 5% significant level. result: there was a highly significant difference of curvature angle and significant difference of rotational speed on the fracture resistance of instruments. race revealed the best fracture resistance followed by protaper then revo-s that showed the less resistance. conclusion: the rotary instruments more prone to fracture when used at more curvature angle and higher rotational speed, as well as the rotary instruments differ from each other according to manufacturing process, taper, cross section and other factors. key words: cyclic fatigue, curvature angle, rotational speed. (j bagh coll dentistry 2013; 25(1):38-42). introduction rotary nickel-titanium (niti) instruments have become very popular during the last years because most of them seem to be safe when used according to the manufacturers’ guidelines; they had ability to enlarge root canals rapidly, and are well suited for preparing severely curved root canals (1). niti instruments have increased flexibility, wider elastic limits and superior resistance to bending and torsional failure compared to stainless steel (ss) instrument. they considered suitable for negotiating curved canals and reduce the risk of transportation, zipping, stripping or ledging the canal. the use of these instruments in rotary motion, offers the possibility for more effective and predictable root canal preparation (2). in1988 walia et al. developed and tested the first niti file by milling a nitinol wire blank into size 15file (3). walia et al. found these hand instruments possessed advantageous bending and torsional properties, which they attributed to low modulus of elasticity. further ingenuity led to hand-piecedriven rotary systems with superior canal centering ability and reduced preparation time, as compared with ss hand instruments. there are several rotary file systems with differing designs, techniques, and tapers present (3). (1)master student, conservative departments, college of dentistry, university of baghdad. (2)professor, conservative departments, college of dentistry, university of baghdad. flexural fatigue and torsional overload have been identified as the main reasons for rotary niti instrument failure, both of which might contribute to fracture depending on canal curvature, instrument design, and diameter. continuous rotation of instruments in curved root canals requires the instrument to flex during each rotation, resulting in cyclic compression and tension, which in turn produces material fatigue (4). materials and method three brands of rotary instruments with tip size 25were used: protaper (f2, variable taper), revo-s (su, .06 taper) and race (0.06 taper). forty instruments for each type were tested within two artificial canals with different curvature angle (40 and 60 ), at different rotational speed (250and 400) rpm. twelve groups were formed, ten instrument for each group. cyclic fatigue testing was conducted with the instrument rotating freely within an artificial canal defined by both the angle and radius of curvature according to pruett et al. (5). instrument were tested within two canals (60 and40 angle of curvature)with radius of curvature for both canals was 5 mm and the width of canal was 1.5 mm in a ss block covered with a swiveling glass cover allowed visualization the file rotating in the canal and the removal of broken instruments after fracture. a marker of permanent red ink placed at19mm on the glass j bagh college dentistry vol. 25(1), march 2013 the effect of curvature restorative dentistry 39 cover of metal block to standardize instrument placement (6). the dental hand-piece was mounted upon a surveyor that allowed for precise and simple placement of each instrument inside the artificial canal, ensuring three-dimensional alignment and positioning the instruments to the same depth for standardization (7). the stainless steel block also mounted and fixed by bench vise to prevent its movement and to obtain fixed relation between the block and the surveyor through hand-piece. each canal filled with glycerin completely to the coronal orifice of the canal, before introducing each instrument to the required length (19mm) inside a canal to reduce friction and heat release (8). the electric motor adjusted to the desired speed (250 or 400) rpm and fixed by surveyor to follow the curvature of the canal then operated. in order to make standard tests, no pecking motion was used, however the authors are aware that in normal clinical practice it is possible to use the pecking technique to increase fatigue resistance (9). the time to fracture recorded then the number of cycles to fracture (ncf) calculated by multiplying the time to fracture in minute by the speed used (rpm). the data were collected and analyzed using software program (spss18) for statistical analysis. one way analysis of variance (anova) and lsd test were used to determine whether there was statistical difference among the mean of cycles to fracture for rotary instruments used. independent t-test was used to evaluate the significant of variance between two speeds at the same curvature as well as between two curvatures at the same speed for each rotary instrument. results descriptive statistical analysis showed that the highest mean of cycles to fracture (mcf), more fracture resistant, represented by c1(race) 625.41cycle when the curvature angle used 40 at 250 rpm speed followed by a1(protaper) in the same curvature and speed had 526.18 cycles, while the lowest mean of cycles to fracture expressed by b4 (revo-s) 259.99 cycle when the angle of curvature was 60 at 400 rpm followed by a3(protaper) in the same curvature and speed which had 335.99 cycle, as in bar chart (fig.1.) between the two curvature (40 for each rotary instrument used at both speed (250 or 400) rpm statistically there was high significant difference (table 2), at the same time between the two speed used (250 and 400) rpm at constant curvature (40 or 60) the relation was significant for each rotary instrument used (table 3). the statistical difference among three instrument used at both speed and angle of curvature was highly significant table 4 , in lsd table 5 for all tests used the higher mcf showed by race followed by protaper then revo-s ( b). thus race (c) was the more fracture resistant followed by protaper (a) and then revo-s (b). discussion the artificial canals used were prepared from ss to resist wearing by friction. the instruments used in this study were: protaper, revo–s and race in this study it's clear that at both speed used the mcf decreased when the angle of curvature increased from 40 as in table 1and there was a highly significant differences between the two curvatures at both speed as in table 2. this result was in consistent with previous studies ankrum et al. (11), kitchens et al. (12), lee et al. (13). ankrum et al. (11) showed that the great care should be taken when instrumenting severely curved canals due to the higher breakage expected as a result of increased stresses placed on the file when curvature angle increased. kitchens et al. (12) revealed that the number of rotations before failure occurs depends on the angle at which the file was rotated; lee et al. (13) attributed that to the increase in the maximum stress level in the files. at both angle of curvature used (40 &60 ) when the speed increased from 250 to 400rpmthe mcf decreased, statistically between the two speed there was a significant difference as in table 3 that was in agreement with martin et al. (9), lopes et al. (8), de-deus et al. (14). martin et al. (9) conclude that increased rotational speeds augment the rubbing of file within the canal lead to file fracture more readily. lopes et al. (8) showed that in a cyclic fatigue the higher speeds produce more heat, thereby induce a faster increase in the instrument temperature, leads to a rapid increase in surface tension, causing fatigue fracture. this finding came in contrast with kitchens et al. (12) who found that the speed per second did not affect the number of rotations to fracture, because the critical number of rotations will occur sooner at higher speed. this contrast in result may be attributed to the high speeds used by kitchens et al. (12) (350-600) rpm or due to the difference in methodology because they used straight non covered groove within metal block and the change in curvature obtained from the change in direction of file used not change in curvature of groove. this result disagrees with gao et al.(15) may be to the abrupt angle of curvature (90 ) used in their study. j bagh college dentistry vol. 25(1), march 2013 the effect of curvature restorative dentistry 40 race showed more fracture resistance than protaper and revo-s and this was in consistent with kim et al. (16) and al-hadlaq et al. (17) who found that the more fracture resistant for race (c) was due to the lower flexural rigidity cross section (triangular) and the near absence of machining marks on the instrument after electropolishing that when an instrument is machined(being ground), plastic deformation occurs at the surface of the metal, resulting in residual stresses that remain at the surface and removed by electro-polishing, while barbosa et al. (18) reported that electro polishing did not increase fracture resistance of niti files. the more fracture resistant for race than protaper in present study was in agreement with zhang et al. (19), kim et al. (16) who showed that was related to the less diameter at the point of maximum curvature for race (at d 5 0.55mm, at d 40.49mm for 60° and 40° angle of curvature respectively) than that for protaper (at d5 0.60mm , at d4 0.54mm ), but this was disagree with xu et al. (20) who according to finite element found that the cross sections with sharp and fine points (race) may have poorer stress distribution than those with a convex(protaper)or triple-helix (revo-s).the triangular cross-section creates a flat transitional surface from the blade to the sectional area and inertia and thus less fracture resistance. in this study protaper was more fracture resistant than revo-s and this come in consistent with necchi et al. (21) who revealed that an instrument with convex triangular cross section (protaper) more fracture resistant than asymmetrical triples helix (revo-s). this may due to a cross-sectional design that distributes the torsional stress well (convex) possessing high flexibility with relatively low reaction stresses on bending would be more suitable for preparing the more severely curved canals. ullmann and peters (22) in contrast with this finding demonstrated that the resistance of an instrument to cyclic fatigue decreases as its diameter increases, because the diameter of protaper at d5(0.60 mm) and at d4 (0.54mm) was greater than that of revo-s at d5 (0.55mm) and at d4 (0.49mm) when the angle of curvature used was 60 and 40 respectively. increase in diameter causes excessive torsional stress that creates a critical amount of cyclic fatigue that cannot be tolerated by the alloy without rupturing (23). basrani et al. (24) revealed that to the asymmetric cross-sectional geometry of the revos su instrument is an innovative feature intended to decrease the stress during root canal preparation and reduce the stress on the instrument and increase fracture resistance. from table1, the mean length of fractured fragment of all rotary instrument used in present study was near 4 mm (at 40 ) and near 5mm (at 60 ) that the point of maximum curvature at the midpoint of arc determined by the angle of curvature and the radius of curvature (25,26). at this point, the stress on the instrument was conceivably greater) 8). there was some difference in length of fractured fragment between different speeds and different curvature. ullmann and peters (22) attributed this distribution of separated fragment lengths to the manufacturing flaws in some distance to the point of greatest deformation would undergo crack propagation sufficient to ultimately cause instrument separation. references 1. schafer e, oitzinger m. cutting efficiency of five different types of rotary nickel–titanium instruments. j endo 2008; 34:198-200. 2. alexandrou g, chrissafis k, vasiliadis l, pavlidou e, polychroniadis e. effect of heat sterilization on surface characteristics and microstructure of mani nrt rotary nickel–titanium instruments. int endo j 2006; 39: 770–8. 3. ray j, kirkpatrick t, rutledge r. cyclic fatigue of endosequence and k3 rotary files in a dynamic model. j endo 2007; 33:1469-72. 4. melo m, pereira e, viana a, fonseca a, buono v, bahia m. dimensional characterization and mechanical behaviour of k3 rotary instruments. int endo j 2008; 41: 329–38. 5. pruett jp, clement dj, carnes dl. cyclic fatigue testing of nickel-titanium endodontic instruments. j endo 1997; 32: 77-85. 6. larsen cm, watanabe i, glickman gn, jianing h. cyclic fatigue analysis of a new generation of nickel titanium rotary instruments. j endo 2009; 35: 401 7. plotino g, grande n, cordaro m, testarelli l, gambarini g. cyclic fatigue of niti rotary instruments in a simulated apical abrupt curvature. int endo j 2010; 43: 226–30. 8. lopes h, ferreira a, elias m, moreira e, oliveira j, siqueira j. influence of rotational speed on the cyclic fatigue of rotary nickel-titanium endodontic instruments. j endo 2009; 35:1013-6. 9. marten b, zelada g, varela p, bahillo jg, magaen f, ahn s, rodreguez c. factors influencing the fracture of nickel-titanium rotary instruments. int endo j 2003; 36: 262-6. 10. tripi tr, bonaccorso a, condorelli gg. cyclic fatigue of different nickel-titanium endodontic rotary instruments. oral surg oral med oral pathol oral radiol endod 2006; 102:106-14. 11. ankrum mt, hartwell gr, truitt je. k3 endo, protaper, and profile systems: breakage and distortion in severely curved roots of molars. j endod 2004; 30: 234-37. 12. kitchens gg, liewehr fr, moon p. the effect of operational speed on the fracture of nickel-titanium j bagh college dentistry vol. 25(1), march 2013 the effect of curvature restorative dentistry 41 rotary with different cross-sections. j endo 2006; 32: 372-5. 13. lee mh, kim av, lee c, hur b, kim h. correlation between experimental cyclic fatigue resistance and numerical stress analysis for nickel-titanium rotary files. j endo 2011; 37:1152-7. 14. de-deus g, moreira el, lopes hp, elias cn. extended cyclic fatigue life of f2 protaper instruments used in reciprocating movement. int endo j 2010; 43:1063–8. 15. gao y, shotton v, wilkinson k, phillips g, ben johnson w. effects of raw material and rotational speed on the cyclic fatigue of profile vortex rotary instruments. j endo 2010; 36:1205-9. 16. kim hc, yum j, hur b, cheung gs.cyclic fatigue and fracture characteristics of ground and twisted nickel-titanium rotary files. j endo 2010; 36:147-52. 17. al-hadlaq s. cyclic flexural fatigue resistance of the revo-s rotary nickel –titanium endodontic files. pakistan oral & dent j 2010; 30: 481-4. 18. barbosa fg, gomes jp, de araujo mp. influence of sodium hypochlorite on mechanical properties of k3 nickel-titanium rotary instruments. j endo 2007; 33: 982-5. 19. zhang ew, cheung gsp, zheng yf. influence of cross-sectional design and dimension on mechanical behavior of nickel-titanium instruments under torsion and bending: a numerical analysis. j endo 2010; 36:1394-8. 20. xu x, zheng y, eng m, en d. comparative study of torsional and bending properties for six models of nickel-titanium root canal instruments. j endo 2007; 33: 52-4. 21. necchi s, taschieri s, petrini l, migliavacca f. mechanical behavior of nickel-titanium rotary endodontic instruments in simulated clinical conditions: a computational study. int endo j 2008; 41: 939–49. 22. ullmann cj, peters oa. effect of cyclic fatigue on static fracture loads in protaper nickel-titanium rotary instruments. j endo 2005; 31:183-6. 23. hilferpb, bergeron be, mayerchak m j, roberts hw, jeanson bg. multiple autoclave cycle effects on cyclic fatigue of nickel-titanium rotary files produced by new manufacturing methods. j endo 2011; 37: 72-4. 24. basrani b, roth k, sas g, kishen a, peters oa. torsional profiles of new and used revo-s rotary instruments: an in vitro study. j endo 2011; 37: 98992 25. yao jh, schwartz sa, beeson tj. cyclic fatigue of three types of rotary nickel-titanium files in a dynamic model. j endo 2006; 32: 55-7. 26. plotino g, grande n, cordaro m, testarelli l, gambarini g. influence of the shape of artificial canals on the fatigue resistance of niti rotary instruments. int endo j 2010; 43: 69–75. figure 1: bar chart showing descriptive statistical analysis for cycles to fracture at both speed used (250&400) rpm within two angle of curvature (40 j bagh college dentistry vol. 25(1), march 2013 the effect of curvature restorative dentistry 42 table 2: independent t-test between two curvature (40 or 60 ) at constant speed (250 and 400) rpm for each rotary system table 3: independent t-test between two speed used (250 and 400) rpm at a constant curvature (40 or 60 ) for each rotary system table 4: anova test among rotary instruments: protaper (a1), revo-s (b1) and race (c1) at both speed 250&400 rpm and angle of curvature (40 &60 ) table 5: lsd table for multiple comparison among the rotary instrument used (a, b and c) in different speeds and angles of curvature. rana.doc j bagh college dentistry vol. 26(4), december 2014 shear bone strength restorative dentistry 86 shear bond strength of endodontic sealers to dentin with and without smear layer and gutta percha (an in vitro study) rana kadhim hasan, b.d.s. (1) majida k. al-hashimi, b.d.s., m.sc. (2) abstract background: the bond strength of root canal sealers to dentin and gutta-percha seems to be an important property for maintaining the stability of root canal filling, which potentially influences both leakage and root strength. the objective of this, in vitro, study was to evaluate the shear bond strength of three different endodontic sealers (guttaflow, ah plus, apexit plus) to dentin, in the presence and absence of the smear layer and gutta percha. material and methods: after slicing off the occlusal 2mm of 60 extracted human maxillary premolar teeth, the exposed dentin served as the tested surfaces; the teeth were fixed with cold cure acrylic, and were divided into two groups according to the smear layer presence, group a without smear layer, when dentin surfaces were irrigated with edta 17% followed by distilled water then subdivided into 3 subgroups according to the type of sealer used; group b when dentin surfaces were washed with distilled water only, then subdivided into 3 subgroups. thirty samples of gutta-percha were prepared and named as group c which was subdivided into 3 subgroups. five mm long section of polyethylene tubes were placed on the dentin or gutta percha surfaces and filled with freshly mixed sealer. after one week, all the samples were tested for shear bond strength by the instron universal testing machine at a cross head speed of 0.5 mm/min. the data was calculated in mpa and was statistically analyzed result: there was a highly significant difference in the shear bond strength (p < 0.05) in comparison among the tested groups, guttaflow showed non-significant difference in bond strength to dentin with and without smear layer, while ah plus and apexit plus showed a high significant difference. conclusions: ahplus showed the highest shear bond strength in all the tested samples, while guttaflow was the least. additionally, ah plus and apexit plus shear bond strengths were affected by the smear layer removal, while guttaflow was not. key words: shear bond strength, guttaflow, endodontic sealers. (j bagh coll dentistry 2014; 26(4):86-89). صةالخال .على ثبات حشوة قناة الجذر الذي بدوره یؤثرعلى تسرب و قوة الجذر خاصیة مھمة للحفاظgutta-percha أن لقوة الرابطة لسدادات قناة الجذرالى عاج السن و و عاج السن بوجود اوعدم ) ,ah plus, gutta-flowapexit plus(كان الغرض من ھذه الدراسة تقییم قوة الترابط القصي بین ثالثة انواع من السدادات اللبیة المختلفة تم تثبیت األسنان في مادة االكریلیك ، و قسمت ) . الضواحك العلیا(سن من أسنان اإلنسان 60تاج منملمیتر 2بعد قطع. gutta-perchaـ و ال smear layer وجود طبقة الـ .smear layerـالى مجموعتین وفقا لوجود طبقة ال -ap)(مجموعات فرعیة وفقا لنوع السدادة المستعملة 3یلیھ الماء المقطر وقسمت إلى edta 17% على سطح عاج السن مع غسل بمادة smear layer دون ب) أ(المجموعة d, ah-d, gf-d. . )(apd-s, ahd-s, gfd-sمجموعات فرعي 3غسل سطح عاج السن بالماء المقطر فقط ثم قسمت إلى ) ب(المجموعة ).(ap-g, ah-g, gf-gمجموعات فرعیة 3وقسمت إلى )ج (أعدت لتكون المجموعة gutta-percha)(ة من ثالثونعین .اختبار قوة الرابط القصي تم بعد اسبوع . gutta-perchaعاج السن أو الـ سطح ملم من البولي اثیلین بسداده مخلوطة حدیثا ووضع على 5استعمل انبوب بطول سجل فرق معنوي غیر ملحوظ في قوة الترابط مع عاج السن بوجود gutta-flow.أظھرت النتائج فرقا معنویا كبیرا. لمیغا باسكال و تم تحلیلھا إحصائیًا تم حساب البیانات بوحدة ا .سجلوا فرقًا معنویًا عالیًا apexit plusو ah plus بینما smear layerاوعدم وجود الـ تأثرت apexit plusو ah plus وقوة الربط القصي للـ . االقل بینھم gutta-flowقوة ربط قصي في جمیع العینات بینما كان اظھر اعلى ah plus: االستنتاج النھائي .فلم تتأثر gutta-flowالى االحسن اما smear layerبازالة طبقة introduction endodontic sealers are the essential components of root-filling materials used to fill the voids and gaps between the main root-filling material and root dentin. good adhesion to tooth material within the root canal is one of the ideal properties of a sealer cement which potentially influences both leakage and root strength (1). the adhesion of root canal filling to the dentinal walls is advantageous for two main reasons. in the static situation, it should eliminate any space that allows percolation of fluids between the obturating material and the dentin wall. in the dynamic situation, it is needed to resist dislodgement of the filling during subsequent manipulations (2). (1)master student. department of conservative dentistry. college of dentistry, university of baghdad. (2)professor. department of conservative dentistry. college of dentistry, university of baghdad. the smear layer as it relates to the root canal system is the layer of debris on the root canal wall and has been shown to be packed into the dentinal tubules. various methods have been used to remove the smear layer. conflict in guide as has been obtained regarding the significance of the presence or the removal of the smear layer (3). some studies concluded that removal of the smear layer prior to filling the root canal system may enhance the ability of filling material to enter the dentinal tubules. this increases the adhesive strength of sealer to dentin; others concluded that removal of the smear layer may impair sealer adhesion to dentin (4,5). different types of sealer have been introduced to endodontics. epoxy resin-type sealers have been used for many years. they showed higher bond strength to dentin than zinc oxide eugenol types and calcium hydroxide-based sealer (6). guttaflow®2 sealer is an alternative root filling j bagh college dentistry vol. 26(4), december 2014 shear bone strength restorative dentistry 87 material introduced into the endodontic practice. guttaflow®2 is a cold flowable filling system for root canals, combining sealer and gutta-percha in one product. the sealers used in this study were guttaflow®2 sealer (coltène/whaledent, germany), ah plus (detrey dentsply, germany), apexit plus (ivoclarvivadent, liechtenstien). the purpose of this study was to evaluate the shear bond strength of guttaflow (silicon based sealer), ah plus (epoxy resin based sealer), apexit plus (calcium hydroxide based sealer) to dentin before and after removal of smear layer and smear layer and gutta percha. materials and methods in this study, 60 extracted, non-carious, human, maxillary, premolars teeth were collected from the orthodontic department, college of dentistry, university of baghdad. standardized preparations of flat dentin surfaces were obtained. by the use of a digital caliper, 2 mm from the occlusal surface of the teeth, were sectioned by the use of a diamond disc in a straight handpiece with a water coolant. the exposed dentin surfaces were inspected with a stereomicroscope to ensure that no enamel remained (7). a custom-made two l-shaped brass molds were set at 24-20-16mm dimensions were used to construct the acrylic blocks, the section of tooth which included the root was embedded in the acrylic within the mold in a direction that standardized for all the samples with the use of dental surveyor. the two parts of mold were separated after the completion of the polymerization process. for dentin sample with smear layer, the dentin surface was washed by distilled water only.(8)for dentin sample without smear layer, the smear layer was removed by irrigation of the dentin surface with 1ml of edta 17% for 1 minute followed by 3ml of distilled water for 1 minute (9, 10). thermostat controlled (45±3oc) water bath was used for softening the standardized cones of gutta percha iso size 140 (11). then they were compacted into cupper rings of 10mm in diameter and 4mm high; the same mold that was used for dentin sample had been used to construct the acrylic blocks for gutta percha. polyethylene tubes were carefully placed with one open side contacting the dentin or gutta-percha, perpendicular to its surface then filled with the freshly mixed sealer (12). a custom made device consisted of a metal board with a fixed handle to hold the sample was used, also there was a handle supporting 400g weight for standardization of sealer weight application. all sealer cylinders were allowed to bench set for 2 hours and stored at 100% humidity at 37o c for 1 week (13). all the specimens were loaded until failure by the instron universal testing machine at across head speed of 0.5 mm/min, the load was parallel to the dentinal surface of the tooth, or gutta-percha surfaces and perpendicular to the long axis of sealer cylinder. the force was recorded in newton divided by the surface area to obtain the shear bond in mpa. the ninety samples were divided into three groupsand each groupwas subdivided into 3 subgroups according to the type of the sealer used: gutta-flow, ah plus, apexit plus;10 specimens for each sealer. group a: 30 dentin samples without smear layer (gf-d, ah-d, ap-d). group b: 30 dentin samples with smear layer (gfd-s, ahd-s, apd-s). group c: 30 gutta-percha samples (gf-g, ahg, ap-g). results figure 1 shows the mean shear bond strength, in mpa, of the tested sealers to dentin with and without smear layer and gutta-percha. figure 1: the mean shear bond strength (mpa). the descriptive statistic results of shear bond strength, in mpa, between the tested sealers and dentin without smear layer are seen in table 1. table 1: descriptive statistic results of shear bond strength, in mpa, between the sealers and dentin without smear layer. groups n mean s.d. min. max. gf-d 10 0.18 0.07 0.15 0.31 ah-d 10 1.30 0.21 0.95 1.59 ap-d 10 0.42 0.11 0.31 0.63 s.d.= standard deviation = min.=minimum max.=maximum j bagh college dentistry vol. 26(4), december 2014 shear bone strength restorative dentistry 88 statistical analysis of the data by using the analysis of variance (anova) was done. there was a highly significant difference in shear bond strength (p < 0.05) in comparison among all tested groups. to compare between groups, independent sample t-test was performed and the results are shown in table 2. table 2: independent sample t-test results comparison t-test p-value gf-d vs. ah-d -16.01 0.000 (hs)*** gf-d vs. ap-d -5.96 0.000 (hs) ah-d vs. ap-d 11.76 0.000 (hs) ***hs: highly significant. the descriptive statistic results of shear bond strength, in mpa, between the tested sealers and dentin with smear layer are compiled in table 3. table 3: descriptive statistic results of shear bond strength, in mpa, between the tested sealers and dentin with smear layer groups n mean s.d. min. max. gfd-s 10 0.17 0.05 0.15 0.31 ahd-s 10 0.31 0.11 0.15 0.47 apd-s 10 0.20 0.08 0.15 0.31 the analysis of variance (anova) showed a highly significant difference in shear bond strength (p < 0.05). table 4 shows the independent sample t-test results. table 4: independent sample t-test results compared groups t-test p-value gfd-s vs. ahd-s -3.86 0.001 (hs)*** gfd-s vs. apd-s -1.10 0.288 (ns)* ahd-s vs. apd-s 2.69 0.015 (s)** *ns: not significant. **s: significant. ***hs: highly significant. the descriptive statistic results of shear bond strength, in mpa, between the tested sealers and gutta-percha are seen in table 5; while table 6 showsthe independent sample ttest results comparing the paired groups regarding shear bond strength between the tested sealer and gutta percha. table 5: descriptive statistic results of shear bond strength, in mpa, between the tested sealers and gutta-percha groups n mean s.d. min. max. gf-g 10 0.25 0.08 0.15 0.31 ah-g 10 0.73 0.17 0.47 0.95 ap-g 10 0.28 0.13 0.15 0.47 table 6: independent sample t-test results compared groups t-test p-value gf-g vs. ah-g -7.95 0.000 (hs)*** gf-g vs. ap-g -0.67 0.511 (ns)* ah-g vs. ap-g 6.64 0.000 (hs) *ns: not significant. ***hs: highly significant. finally, paired groups were compared in order to find the effect of the removal of the smear layer on the shear bond strength, of the different sealers used, to both dentin and gutta percha. table 7: t-test to compare each two groups sealer type compared groups t-test sig. guttaflow gf-d vs. gfd-s 0.60 (ns)* gf-d vs. gf-g -1.90 (ns) gfd-s vs. gf-g -2.61 (s)** ah plus ah-d vs. ahd-s 13.29 (hs)*** ah-d vs. ah-g 6.70 (hs) ahd-s vs. ah-g -6.50 (hs) apexit plus ap-d vs. apd-s 5.33 (hs) ap-d vs. ap-g 2.74 (s) apd-s vs. ap-g -1.71 (ns) *ns: not significant. **s: significant. ***hs: highly significant. discussion shear bond test was used, in this study, because it is easier to be performed and allowed testing gutta percha and dentin specimens in a similar manner. also it provided homogenous results with considerably low variation of bond strength (11,12). the adhesion of endodontic sealers to the coronal dentin was used rather than root dentin, because root dentin is not uniform and the surface of the canal walls may differ widely. also there is a gradual decrease in the number of dentinal tubules from coronal to apical part of dentin, this agreed with kandaswamy et al. (2). ethylene diamine tetra acetic acid (edta) 17% solution was used, in this study, because from the shear bond aspect, edta was a good irrigant to be used as a final rinse for smear layer removal (2). ah plus showed a superior dentin bond strength than apexit plus, with and without smear layer; agreed with eldeniz et al. (7); gopi-krishna et al. (14); this may be due to its ability to react with any exposed amino groups in collagen to form covalent bonds. ah plus has a very low shrinkage rate while setting and its long-term dimensional stability. gutta-flow showed the least bond strength to dentin, this result is in j bagh college dentistry vol. 26(4), december 2014 shear bone strength restorative dentistry 89 agreement with saleh et al. (4) and coba-nkara et al. (15). this may be due to the poor wetting of guttaflow on the dentin surface because of the presence of silicon, which possibly produces high surface tension forces, making the spreading of these materials more difficult.ah plus scored the highest shear bond strength to gutta-percha, due to the presence of bisphenol a epoxy resin in its formulation that bond chemically with gutta percha agreed with mamdooh (16) and disagreed with stoll et al. (17); while the setting reaction of apexit plus form an amorphous calcium disalicylate, which does not bond to gutta-percha. finally to evaluate the effect of smear layer removal on each sealer, it was found that ah plus and apexit plus were highly affected by the removal of smear layer, this finding agreed with gopikrishna et al. (14). while guttaflow bond strength was not affected by the removal of the smear layer because edta may significantly decreases the wetting ability of dentinal wall. therefore; a suitable dentin substrate could be provided for the adhesion of materials with hydrophobic nature as ah plus.furthermore, the removal of the smear layer allowed the extension of the sealer tags into the opened dentinal tubules, creating an efficient microretention (5). the conclusions that can be drawn from this study are: 1. ah plus showed the highest shear bond strength in all the tested samples. 2. gutta-flow scored the least shear bond strength. 3. ah plus and apexit plus shear bond strengths to dentin were affected by the smear layer removal, while gutta-flow was not. references 1. grande nm, plotino g, lavorgna l. influence of different root canal filling material on the mechanical properities of root canal dentin. j endod 2007; 33: 859-63. 2. kandaswamy d, venkateshbabu n, arathi g, roohi r, anand s. effects of various final irrigants on the shear bond strength of resin-based sealer to dentin. j conserv dent 2011; 14(1): 40–2. 3. torabinejad m, handysides r, khademi aa, bakland lk. clinical implications of the smear layer in endodontics: a review. oral surg oral med oral pathol oral radiol endod 2002; 94(6): 658-66. 4. saleh im, ruyter ie, haapasalo m, orstavik d. the effect of dentine pretreatment on the adhesion of rootcanal sealers. int endod j 2002; 35: 859-66. 5. hashem aa, ghoniem ag, luttfy ra, fouda my. the effect of different irrigating solutions on bond strength of two root-canal filling systems. j endod 2009; 35: 537-40. 6. lee k, williams m, camps j, pashley d. adhesion of endodontic sealers to dentin and gutta-percha. j endod 2002; 28:684–8. 7. eldeniz au, erdemir a, belli s. shear bond strength of three resin based sealers to dentin with and without the smear layer. j endod 2005; 31(4): 293–6. 8. mamatha y, ballal s, gopikrishna v, kandaswamy d. comparison of sodium hypochlorite and edta irrigants with an indigenous solution as an alternative to mtad. j conserv dent 2006; 9(1): 48-52. 9. prabhu sg, rahim n, bhat ks, mathew j. comparison of removal of endodontic smear layer using naocl, edta, and different concentrations of maleic acid – a sem study. endodontol 2003; 15: 205. 10. prado m, gusman h, gomes bp, simão ra. scanning electron microscopic investigation of the effectiveness of phosphoric acid in smear layer removal when compared with edta and citric acid. j endod 2011; 37(2): 255-8. 11. tagger m, tagger e, tjan a, bakland l. shearing bond strength of endodontic sealers to gutta-percha. j endod 2003; 29(3): 191-3. 12. teixeira cs, alfredo e, thomé lh, gariba-silva r, silva-sousa yt, sousa-neto md. adhesion of an endodontic sealer to dentin and gutta-percha: shear and push-out bond strength measurements and sem analysis. j appl oral sci 2009; 17(2): 129-35. 13. wachlarowicz aj, joyce ap, roberts s, pashley dh. effect of endodontic irrigants on the shear bond strength of epiphany sealer to dentin. j endod 2007; 33(2):152-5. 14. gopikrishna v, venkateshbabu n, krithikadatta j, kandaswamy d. evaluation of the effect of mtad in comparison with edta when employed as the final rinse on the shear bond strength of three endodontic sealers to dentine. aust endod j 2011; 37(1): 12-7. 15. cobankarafk, oruoğlu h, belli s. adhesion of a newly developed sealer to dentin: an in vitro study. int endod j 2006; 30(1): 9-16. 16. mamdooh ak. shear bond strength measurement of different root canal sealers to gutta-percha. j bagh coll dentistry 2006; 18(3): 21-5. 17. stoll r, thull p hobeck c, yüksel s, jablonskimomeni a, roggendorf mj, frankenberger r. adhesion of self-adhesive root canal sealers on guttapercha and resilon. j endod 2010; 36(5): 890-3. hasanain.doc j bagh college dentistry vol. 26(4), december 2014 effect of poly propylene restorative dentistry 32 effect of poly propylene fibers incorporation and their oxygen plasma treatment on tensile strength, wettability and wear resistance of heat cure denture base acrylic resin hasanain k.a. alalwan, b.d.s. m.sc. (1) abstract background:recently, poly propylene fibers with and without plasma treatment have been used to reinforce heat cure denture base acrylic but, so far some of properties like tensile strength , wettability and wear resistance not evaluated yet, the aim of the study is to clarify the influence of incorporation of treated and untreated fibers on these properties. materials and methods: twenty one specimens were fabricated for every tested property(tensile strength, wear resistance and wettability) that classified into three groups(control, untreated poly propylene fibers reinforced specimens and oxygen plasma treated group)and for each test seven samples were used(n=7). tensile strength was tested using instron universal testing machine, wear resistance was evaluated by pin on disk wear measurement method while, a digital microscope supplied with high resolution camera was utilized to measure the contact angle reflecting wettability grade. one wayanova table and lsd were used to analyze the results. results: the tensile strength showed a paradoxical effect, plasma treated samples group demonstrated a negative influence in contrary, to the untreated group that revealed positive high significant impression. the plasma treated group had manifested apositive significant difference regarding wear resistance whilst, the beneficial effect of treated and untreated poly propylene fibers addition was obvious with high significant difference. conclusion: incorporation of o2 plasma treated and untreated poly propylene fibers to heat cure poly methyl methacrylate resin was beneficial regarding the tested properties except for addition of plasma treated poly propylene fibers on tensile strength. key words: poly propylene fibers, tensile strength, wettability, wear resistance, denture base. (j bagh coll dentistry 2014; 26(4):32-38). الخالصة لكن لحد االن لم یختبر تاثیرھا على قوة الشد وقابلیة لقاعدة الطقم قد استخدمت في تقویة الراتنج االكریلي الحراري االوكسجین حدیثا الیاف البولي بروبیلین مع و بدون معالجة بالزما:الخلفیة .طب ومقاومة البلىرالت بواقع سبعة نماذج اختباریةلكل من مجموعة السیطرةو مجموعة النماذج المدعمة بااللیاف المعالجة ببالزما دى و عشرین عینة قد اختبرت لكل صفة من الصفات الثالثةاح:المواد و االسالیب ة البلى بطریقة المسمار على كروسكوب رقمي وفحصت مقوماختبرت قوة الشد بجھاز االنسترون و اختبرت قابلیة الترطب بمای.االؤكسجین والمجموعة االخیرة لاللیاف غیر امعالجة رتین فقد اظھرتا تأثرا تباینا واضحا عند فحص قوة الشد لصالح اضافة االلیاف غیر المعالجة بینما بینت تاثیر سلبي لاللیاف المعالجة اما ما یخص الصفتین األخاظھرت النتائج :النتائج.القرص .رطیبایجابیا خصوصا في صفة قابلیة الت المعالجةمع محدودیة البحث یستنتج بأن اضافة االلیاف المعالجة و غیر المعالجة اثر ایجابیا بالصفات المدروسة في ما عدا قوة الشد مع االلیاف :االستنتاج introduction fiber reinforced polymer resin composites have sorted several types of fibers with diverse traits. carbon fibers revealed poor esthetics, glass fibers manifested hydrolytic degradation and corrosion leading to strength reduction and destruction of polymer fiber interface (1,2). poor esthetics and polishibility were apparent with aramid fibers (3).ultra high modulus poly ethylene fibers reinforcement have been researched for several years and these studies showed controversial reinforcing effects (4-6). while, poly propylene fibers (pp fiber) has been harnessed to reinforce denture base acrylic resin recently,polypropylene fiber is considered as one of the polyolefin synthetic fibers that characterized with strength, staining and abrasion resistance (7). impact strength was the most obvious improved property moreover, oxygen plasma treatment have beenrelied on to enhance fiber-matrix impregnation (8,9). the influence of pp fiber incorporation on tensile strength, wear resistance and wettability have not tested yet. a low-temperature glowdischarge oxygen plasma impact on the structure (1)assistant lecturer. department of prosthodontics, college of dentistry, university of baghdad and properties of exposed materials especially polymers results in etching and changes in a microstructure of the surface. as a consequence of the change in a surface layer structure, a number of functional properties, in particular, adhesion, sorption and tribology are changed (10). noort have attributed inclination of dentures to fracture to low tensile strength which is of no more than50 mpa, low elastic and flexural modulus and lack of fracture toughness (11). wear resulted from removal and relocation of materials via the contact of two or more materials leading to material loss. wear resistance is deemed as one of the properties that be judiciously developed by composite (12). in bite splint fabrication, heat cure acrylic is utilized where high wear resistant material is usually preferred to keep the new occlusal relation and withstand opposing natural or artificial dentition (13). denture base material wettability play an effective role in denture retention, complete wetting of denture surface increase the capillary force therefore, raising denture retention in static and dynamic situations (12). in this study, the reinforcing effect of poly propylene fibers incorporation to poly methyl methacrylate and their oxygen plasma j bagh college dentistry vol. 26(4), december 2014 effect of poly propylene restorative dentistry 33 treatment effect on tensile strength, wear resistance and wettability have evaluated. materials and methods incorporation of (6 mm length) 2.5 % (by weight) poly propylene fibers (pp fibers) (cracecemfiber®) (figure1) to poly methylmethacrylate heat curepowder (pmma)(superacryl® plus, czech republic-cross linked) in this study was according to recent studythat have showed an incorporation of that percentage had the best effect regarding impact and transverse strengths which might considered main properties in measuring the strength of materials (9). figure 1: poly propylene fibers the specimens were grouped to three groups for each one of the three tests (tensile strength, wear resistance and wettability test) of this study :control group, specimens with untreated pp fibers and the third group was specimens with oxygen plasma treated pp fibers whereas the number of specimens for each group was seven(n=7).pp fibers was treated with oxygen plasma usingdcglow discharge system device with 6 minutesexposure time(figure2),gas pressure was limited to 0.5 x10-1mlbar while the flow rate of gas was 10 ml/ min using flowmeter (ministry of science and technology-iraq, physics department). ftir (fourier transform infrared spectrophotometer, shimadzu, 8400sjapan) (figure3) was utilized to find out and identifyfunctional groups pp fibers surface involvement (figure4a,b). test specimens elaboration wasdone via making plastic patterns cut with highly precise laser turning machine. conventional flasking method has undertaken after mould preparation to form specimens.all the specimens for all the three tests were finished and polished. figure 2: plasma figure 3: ftir device chamber figure 4a: ftri of untreated pp fibers. o-h c=o figure 4b: ftir of treated pp fibers with (c=o, 1719) and (o-h, 3382) functional groups. j bagh college dentistry vol. 26(4), december 2014 effect of poly propylene restorative dentistry 34 incorporation of polypropylene fibers 2.5% by weight added to the subtracted weighed powder. the required weight of the fiber and powder was measured by electronic balance (with accuracy 0.0001g).the weight of fibers was secured by the following equation: fiber reinforcement percentage % = weight of fiber/weight of fiber+ weight of matrix. powder and pp fibers mixing wereachieved using mortar and pestle tilluniform mixture was obtained. mixing with monomer was done incrementally for throughout dispersion of the fibers. tensile strength test dumbbell shaped specimens were fabricated according to astm specification d-638m (1986) with dimensions asexplicitly illustrated in figure 5. figure 5: dimensions of tensile test pattern. afterwards, they were conditioned in distilled water for two days at room temperature25cº±2before testing according to ada specifications. the testing procedure was accomplished using instron universal testing machine (laryee, make test easy, china) with crosshead speed 0.5 mm/min and maximum loading of 20kg. tensile strenfth was calculated electronically via the software of the testing machine.(figure6) figure 6: tensile strength pp fiber reinforced specimen after submitting to the test. wear resistance test pin on disk wear testing device was used that recognized with high reproducibility of results (14, 15), designed at university of technology, material engineering department, resistance laboratory-iraq. the specimens were cylindrical in shape with dimensions of 20mm length and 10mm diameter according to the device requirement (figure7). the pin was the held specimen while the disk was stainless steel wheel which revolve 950 r/min, the specimen was weighed before and after the testing procedure, after securing the specimen to the holder and putting of 10n load on the horizontal arm, the device switched on for 10 minutes (wear testing time)(16 ). the distance between the center of the disk and center of the specimen was 65mm.the wear resistance was calculated with the following equation: wear resistance (gr/mm) =change in weight/slide distance (slide distance=2π×radius distance between centers of disk and specimen×number of cycles ×time of test) (16). the disk was cleaned with abrasive grit paper after each test (figure8).all specimens were immersed in distilled water for 48 hours before testing. figure 7: wear figure 8: pin on disk specimens mould with held specimen. wettability contact angle measurement was harnessed to determine the wettability; the angle was between the base of the sessile drop and the tangent line contacting the solid, liquid and air simultaneously. dispersing of distilled water 10µlatthe center of the fabricated sample using pipette.dimensions of the sample 8×30×2mm width, length and thickness respectively (17).static sessile drop method was utilized in this study. as the water dispersed wait for 5 minutes to allow the drop to be in status of equilibrium. measurement of the contact angle was accomplished employing a digital microscope (dino-lite digital microscope pro -taiwan) at magnification 45× supplied with camera (high resolution 1024×768 pixel) and software (dino capture2.0 version 1.3.3.) granted j bagh college dentistry vol. 26(4), december 2014 effect of poly propylene restorative dentistry 35 a completeand precision analysis to the contact angle.(figure9) figure 9: digital microscope with specimen. descriptive statistical analysis involving: arithmetic mean, standard deviation and standard error in addition to inferential statistical analysis including: ftest by analysis of variance andleast significant difference (lsd) was conducted for further verification. p > 0.05 nonsignificant (ns), p≤ 0.05significant(s) and p≤0.001 high significant (hs). results tensile strength untreated polypropylene fiber reinforced samples showed the higher mean (58.2571)while the treated revealed the lowest (53.6857) as illustrated in table1.anova tablein table 2 displayed a statistical significant difference (p=0.003) among the studied groups. table 3 demonstrated a positive significant effect of the untreated pp fiber reinforced samples over the control, in opposite to non-significant relation of control to treated pp fiber reinforced samples, while a high significant difference ( p=0.001) between treated and untreated pp fiber samples in favor of untreated one. table1: descriptive statistics of tensile strengthtest mpa among the studied groups. table2: anova table of tensile strength testamong the studied groups. table 3: lsd of tensile strength test groups plasma treated pp fiber reinforced specimens exhibited the highest wear resistance because they showed the lowest weight loss per millimeter (0.000010),whilst the control manifested the lowest wear resistance(0.000012) moreover, anova table presented a significant difference among tested groups(p=0.030) as shown in table4 and table 5.multiple comparison with lsd(table6) revealed a non-significant difference between groups except between control and plasma treated pp fiber reinforced specimens(p=0.009). table 4. descriptive statistics of wear resistance (gm/mm) test among the studied groups. table 5: anova table of wear resistance test among the studied groups. group n mean s. d. s. e. control 7 54.458 2.2063 0.8339 untreated pp f 7 58.257 2.9102 1.0999 plasma treated pp f 7 53.685 1.4690 0.5552 total 21 sig. p-value f s 0.003 8.114 sig. p-value mean difference study group study group s .006 -3.79857 untreated ppfiber control ns .533 0.77286 treated ppfiber control hs .001 4.57143 plasma treated ppfiber untreated pp fiber group n mean s. d. s. e. control 7 0.000012 .0000008 .0000003 untreated pp f 7 0.000011 .0000013 .0000005 plasma treated pp f 7 0.000010 .0000018 .0000007 total 21 sig. p-value f s 0.030 4.311 j bagh college dentistry vol. 26(4), december 2014 effect of poly propylene restorative dentistry 36 table 6: lsd of wear resistance test among studied groups wettability table 7 offers the effect of incorporation on the mean contact angle among studied groups, the highest mean was in control group so, represented the lowest wettability however, the oxygen plasma treated pp fiber reinforced specimens showed the contrary. the evidence on the strong effect of pp fibers incorporation and their plasma treatment on wettability of pmma has proved by anova table and further affirmed statistically with lsd, where a high significant difference between each two different groups as illustrated in table 8 and table 9. table7: descriptive statistics of wettability test among the studied groups. table 8: anova table of wettability test among the studied groups. table 9: lsd of wettability test among studied groups discussion the negative effect of plasma treatment to pp on the tensile strength was strong enough to clearly reduce it, it could be inferred to the water absorption of pp fibers was improved by plasma treatment. this fact was caused by the creation of polar c=o ando-h groups on the surface after plasma treatment.it happen due to plasma probably breaks the c–h and/or c–c bonds creating free radicals, which can react with the activated oxygen species in the discharge leading to the formation of these moieties, this is in agreement with skacelova et al and morent et al (18, 19). absorption of water by pmma accomplished slowly over a period of time, essentially because of the polar properties of the resin molecules. high water uptake equilibrium can soften an acrylic resin because the absorbed water acts as a plasticizer and reduce the strength of the material (20). the incidence of water uptake into pmma networks are substantially controlled by resin polarity, affected by the concentration of polar groups available to form hydrogen bonds with water and network topology (21), therefore, incorporation of oxygen plasma treated poly propylene fibers to pmma had increased the water absorption significantly (9) and pmma tensile strength is negatively affected by water absorption and ambient moisture, this is in agreement with ishiyama et al (22), in addition to the acrylic used in this study was of cross linked type that might exaggerate the water absorption (23). furthermore, a previous study conducted to review all the articles related to fiber reinforced denture base materials had noticed that plasma treatment for uhmpe fiber had not increased pmma strength in comparison to untreated (2). generally, plasma treatment for fibers can lessen the tensile strength of the fibers themselves due to their loss of weight and diameter reduction (24,25). on the other hand, two essential properties of pp fiber are moisture absorption very low capability and good toughness (26) thus, the incorporation of untreated pp fiber has increased the tensile strength while, the plasma treated was equivalent to control group where the benefit of pp fiber addition had cancelled after changing the surface of the fibers and making them more hydrophilic, that encouraged water absorption and weakened the material. poor impregnation of the untreated fibers did not precipitate a negative sig. pvalue mean difference study group study group ns .097 .0000013 untreated ppfiber control s .009 .0000021 treated ppfiber control ns .259 .0000009 plasma treated ppfiber untreated pp fiber group n mean s.d. s.e. control 7 45.6039 2.701025 1.020892 untreated pp f 7 35.7269 3.355893 1.268408 plasma treated pp f 7 27.8051 2.753189 1.040608 total 21 sig. p-value f hs .000 63.887 sig. p-value mean difference study group study group hs .000 9.877000 untreated pp fiber control hs .000 17.798714 plasma treated pp fiber control hs .000 7.921714 plasma treated pp fiber untreated pp fiber j bagh college dentistry vol. 26(4), december 2014 effect of poly propylene restorative dentistry 37 influence, it could be attributed to solicitude during fiber-powder blending and homogenous mixing with monomer that distribute the fibers and prevent their accumulation. wettability of acrylic reinforced with untreated and oxygen plasma treated pp fiber was highly magnified, regarding the treated pp, it might be elucidated by increasing the water affinity of the pp fiber itself via plasma treatment this is in agreement with several researchers (27-29), that overshadowed on pmma-pp fiber composite wettability and occurrence of new functional groups as annotated above guiding the change in a surface layer structure. wettability of the untreated pp fibers incorporated samples was increased considerably because the addition of randomly oriented pp fibers elevates the surface roughness even non-significant statistically (9), the surface roughness and wettability are directly proportional (30), consequently, the untreated pp fiber samples wettability had raised. high abrasion resistance of pp fiber (26) had increased the untreated pp fiber reinforced samples wear resistance yet, that not significant statistically however, after plasma treatment it significantly improved in comparison to control group and this may be attributed to formation of functional groups on the pendant methyl group of the isotactic pp fiber leading to increased crosslinking that decreased plastic flow which in turn increased the wear resistance and that was consistent with kyomoto et al and drobny (31, 32). resin composite capability to withstand wear relies on filler–matrix interactions and highly sensitive for spacing between them, the oxygen plasma treatment had played that role and increased the wear resistance (33). finally, it can be concluded that incorporation of o2 plasma treated and untreated pp fibers to heat cure pmma was beneficial regarding the tested properties except for addition of treated pp fiber on tensile strength. references 1. vallittu pk. compositional and weave pattern analyses of glass fiber in dental polymer fiber composites. j prosthod 1998; 7: 170-6. 2. vallittu pk. a review of fiber-reinforced denture base resin . j prosthod 1996; 5(4): 270-6. 3. jagger dc, harrison a, jandt k. the reinforcement of denture. j oral rehabil 1999; 26:185-94. (ivsl). 4. geerts gavm, overturf jh, oberholzer tg. the effect of different reinforcements on the fracture toughness of material for interim restoration. j prosthet dent 2008; 99: 461-7. 5. uzun g, hersek n, tincer t. effect of five woven fiber reinforcement on the impact and transverse strength of a denture base resin. j prosthet dent 1999; 81: 616-20. 6. williamson dl, boyer db, aquilino sa, leary jm. effect of polyethylene fiber reinforcement on the strength of denture base resins polymerized by microwave energy. j prosthet dent 1994; 72(6):635-8. 7. sarja jk, anna ll. textile. 9th ed. new jersey: upper saddle river; 2002. p. 109-13 8. mowade tk, dange shp, thakre mb, kamble vd. effect of fiber reinforcement on impact strength of heat polymerized polymethyl methacrylate denture base resin: in vitro study and sem analysis. j adv prosthodont 2012; 4(1): 30-6. 9. waffaa i. m. the effect of addition of untreated and oxygen plasma treated polypropylene fibers on some properties of heat cured acrylic resin (a comparative study). a master thesis, department of prosthodontics, university of baghdad, 2013. 10. maximov a, gorberg b, titov v. possibilities and problems of plasma treatment of fabrics and polymer materials. in: textile chemistry – theory, technology, equipment (ed. a.p.moryganov). – new york: nova sci. publishers, inc., commack; 1997. p. 225 –45. 11. noort rv. introduction to dental materials. 2nd ed. else view science limited, mosby; 2002. p.216. 12. powers jm, sakaguchi rl. craig's restorative dental materials. 12th ed. st. louis: mosby co.; 2006. p.78. 13. widmalm se. use and abuse of bite splints. university of michigan; 2004. p.1-14. www.yumpu.com/en/document/view/5110164/useand-abuse-of-bite-splints ( retrieved in 12-april-2014). 14. prieto g, faulkner m, alcock jr. the influence of specimen misalignment on wear in conforming pin on disk tests. wear 2004; 257(1-2): 157-66. 15. saikkov, calonius o, keranen j. effect of counterface roughness on the wear of conventional and crosslinked ultrahigh molecular weight polyethylene studied with a multi-directional motion pin-on-disk device. j biomedical mater res 2001; 57(4): 506-12. 16. mustafa fm. assessment of some mechanical properties of imprelon and duran thermoplastic biostar machine sheets in comparison with some types of acrylic resin. a master thesis, department of prosthodontics, university of baghdad, 2012. 17. shaymaa ha. the effect of plasma treatment on the bonding of soft denture liners to heat cured acrylic resin denture base material and on some surface properties of acrylic resin polymer. a master thesis, department of prosthodontics, university of baghdad, 2012. 18. skacelova d, fialova m, stahel p, cemak m. improvement of surface properties of reinforcing polypropylene fibers by atmospheric pressure plasma treatment. icpig (conference), augt 28th sep 2nd, 2011; belfast, uk, topic no. d13. 19. morent r, de geyter n, leys c, gengembre l, payen e. comparison between xpsand ftir-analysis of plasma-treated polypropylene film surfaces. surface and interface analysis 2008; 40: 597–600. 20. barsby mj. a denture base resin with low water absorption. j dent 1992; 20: 240–4. 21. malacarne j, carvalho rm, de goes mf, svizero n, pashley dh, tay fr, yiu ck, carrilho mr. water sorption/solubility of dental adhesive resins. dent mater 2006; 22: 973–80. 22. ishiyama c, yamamotoy, higoy. effects of humidity history on the tensile deformation behaviour of poly (methyl –methacrylate) (pmma) films. 2005 mrs spring meeting. http://journals.cambridge.org/action/displayabstract http://www.yumpu.com/en/document/view/5110164/use http://journals.cambridge.org/action/displayabstract j bagh college dentistry vol. 26(4), december 2014 effect of poly propylene restorative dentistry 38 mrs online proceedings library (retrieved 5/april/2014). 23. armia t, murata h., and hamada t. the effect of cross-linking agent on the water sorption and solubility characteristic of denture base resin.j prosth. dent 1996; 23: 476-80. 24. yasuda t, gazicki m, yasuda h. plasma polymerization and plasma treatment. j applied polymer science. applied polymer symposium 1984; 38: 201-14. 25. kabajev m, prosycevas i, kazakeviciute g, valienev. plasma modification of structure and some properties of polyethylene therepthalate films and fibers. material science 2004;10(2):173-6. 26. mandal j. polypropylene fiber and its manufacturing process, properties, advantages, disadvantages and applications of polypropylene fiber.http://textilelearner.blogspot.com/2013/01/polypro pylene-fiber-and-its.html.( retrieved 10-april-2014). 27. morent r, de geyter n, gengembre l, leys c, payen e, van vlierberghe s, schacht e. thin films processing and surface engineering surface treatment of a polypropylene film with a nitrogen dbd at medium pressure. the european physical journal of applied physics 2008; 43(3): 289-94. (ivsl). 28. wei q, qi li, wang x, huang f, gao w. dynamic water adsorption behaviour of plasma-treated polypropylene nonwovens. polymer testing 2006; 25(5): 717–22. (ivsl). 29. kang j, sarmadi m. plasma treatment of textilessynthetic polymer-based textiles. aatcc review 2004; 4 (11):29-33. (ivsl). 30. kubiak kj, wilson m, mathia tg, carval ph. wettability versus roughness of engineering surfaces. wear 2011; 271: 523–8. 31. kyomoto m, moro t, konno t, takadama h, yamawaki n, kawaguchi h, takatori y, nakamura k, ishihara k. enhanced wear resistance of modified cross-linked polyethylene by grafting with poly(2methacryloyloxyethyl phosphorylcholine).j biomed mater res a 2007; 82(1):10-7. 32. drobny jg. ionizing radiation and polymers, principles, technology and applications. 1st ed. 225 wyman st. waltham am.02541.usa; 2013. p. 104-5. 33. zhou zr, zheng j. tribology of dental materials: a review. j physics applied physics 2008; 41:1-22. http://textilelearner.blogspot.com/2013/01/polypro dalia f.docx j bagh college dentistry vol. 28(2), june 2016 periodontitis among pedodontics, orthodontics and preventive dentistry 115 periodontitis among a group of type twodiabetic patientsin relation to risk of vascular disease dalia kudier abbas, b.d.s, m.sc. (1) sulafa k. el-samarrai, b.d.s., m.sc., ph.d.(2) abstract background: type two diabetic patients have higher risk of cardiovascular and periodontal disease. furthermore, patients with more severe periodontal disease have higher incidence of cardiovascular disease. this study aimed to assess the association between periodontal health status and the risk of vascular disease in type 2 diabetic patients. materials and methods: one hundred type 2 diabetes mellitus patients and fifty apparently healthy males were enrolled in this study. oral examinations conducted were; plaque index, calculus index, gingival index, probing pocket depth, and clinical attachment level. for the assessment of vascular risk, arterial stiffness index was used. results: according to arterial stiffness index, type 2 diabetic patients were categorized into two groups: group a: type 2 diabetic patients without vascular disease risk. group b: type 2 diabetic patients with vascular disease risk. the periodontal disease parameters including gingival index, probing pocket depth, and clinical attachment level were higher in healthy controls in comparison to diabetics and in group b in comparison to group a. the difference between group a vs. group b for probing pocket depth is of highly significant (p<0.01) and for clinical attachment level is statistically significant (p<0.05). conclusion: the increase in severity of periodontal disease can be used as an indicator for the increase of risk for vascular disease in type 2 diabetes patients. key words: periodontal disease, type 2 diabetes mellitus, vascular risk. (j bagh coll dentistry 2016; 28(2):115-118). introduction periodontitis is a common chronic inflammatory disease characterized by destruction of the supporting structures of the teeth (the periodontal ligament and alveolar bone). it is one of the most considerable health problems because periodontitis leads if not treated, in its terminal stages to loss of teeth (1,2). many studies have suggested a link between type 2 diabetes mellitus and increased risk of progressive periodontal destruction (3-6). on the other hand, other studies reported an association between periodontal disease and cardiovascular disease and found a significant higher incidence of cardiovascular disease in subjects with periodontal disease compared to subjects without periodontal disease, or in subjects with more severe periodontitis compared to subjects with less severe periodontitis (7-9). type 2 diabetes patients have higher risk of cardiovascular disease compared with those without diabetes (10). arterial stiffness index (asi) is a non-invasive and effective method for early detection of vascular disease. it is a test used to indicate the stiffness of the arteries and it describes a key aspect of cardiovascular health (11,12). this study aims to provide knowledge about the risk of vascular disease in type 2 diabetic patients through studying periodontal health status as an indicator of risk for vascular disease. (1)ph.d. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)professor. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. materials and methods one hundred type2 diabetes mellitus and fifty apparently healthy males were enrolled in this study recruited from national diabetes center, university of al-mustnasiriya, from january 2014 to february 2015. type2 dm patients were on oral hypoglycemic drugs. their age range was 45–55 years and duration of diabetes mellitus was 2-15years. the exclusion criteria for the type 2 diabetic patients included: smokers, patients treated with insulin, patients with a concurrent acute illness or with a major liver, thyroid or other endocrine diseases, patients suffered an illness likely to prevent their involvement in the study such as the following clinical endpoints of vascular disease: angina pectoris, myocardial infarction, transient ischemic attack, stroke. the weight and height were taken to calculate body mass index (bmi) according to the following equation: bmi = weight (kg) ÷ [height (m)]². the asi was measured after training and supervision by a specialist physician in the national diabetes center, university of almustnasiriya by using an automated digital oscillometric device that is called commercially as (vital vision) and which provides an indicator, the h-value (arterial hardness indicator) (figure 1), that quantifies the degree of arterial hardness depending on the variations in pulse wave amplitude obtained while measuring blood pressure(13). oral examinations included in this study were: plaque index of silness and loe (14), calculus j bagh college dentistry vol. 28(2), june 2016 periodontitis among pedodontics, orthodontics and preventive dentistry 116 index (according to calculus component of periodontal disease index (pdi) which was introduced by ramfjord(15), gingival index of loe and silness (16), periodontal status was determined using measurements of probing pocket depth (ppd), gingival recession and clinical attachment level measurements (cal) from six sites on each tooth (mesiobuccal, mid-buccal, disto-buccal, mesiolingual, midlingual, disto lingual). student's ttest used for the significance of differences of the quantitative data between two means and anova test for more than two independent means and lsd was used to measure the precision of a variety of means between two mean values. a probability value (p<0.05) was considered to be statistically significant and (p<0.01) was considered to be statistically highly significant. pattern 1: 1 to 3 bars appear when the cardiovascular system is normal pattern 2: 4 to 6 bars suggest a condition of progressing arterial hardness figure 1: h-value measurement result on the lcd display of asi measuring device results according to arterial stiffness index, type 2 diabetic patients were categorized into two groups: group a: type 2 diabetic patients with normal asi (without vascular disease risk) group b: type 2 diabetic patients with abnormal asi (with vascular disease risk) the mean ages of group b patients were significantly greater than both group a and controls (p<0.05). the mean values of bmi in study groups showed no statistical significant difference. the mean durations of diabetes in group a and group b appeared to have no statistical significant difference (p>0.05) (table 1). concerning oral cleanliness, this study showed that the mean values of plaque index and calculus index among groups and between each two groups were statistically non-significant (p>0.05) (table 2). the mean values of gingival index showed that the differences between group a and group b vs. controls were significant (p<0.05) and highly significant (p<0.01) respectively. on the other hand, gingival index mean values showed no statistical significant difference (p>0.05) concerning the comparison of group a vs. group b (table 2).the mean values of probing pocket depth showed that the differences between group a and group b vs. controls were statistically highly significant (p<0.01).in regard to cal the mean values showed that the differences between group a and group b vs. controls were statistically highly significant (p<0.01) and the difference between group a vs. group b was statistically significant (p<0.05) (table 2). discussion in this study, type 2 diabetic patients have significantly higher periodontal disease parameters including: gingival index, probing pocket depth, and clinical attachment level than healthy controls. this finding is in line with other studies which proved and confirmed that type 2 diabetes mellitus has been unequivocally considered as a major risk factor for periodontitis and the risk of progressive periodontal destruction in subjects with diabetes has been demonstrated in many studies in comparison with controls (3-6). in contrast to above findings only few reports showed either no relation or weak significant relation between periodontal disease and type 2 diabetes (17,18). in type 2 diabetics, it was found that the risk of cardiovascular disease mortality more than double compared with that in age-matched subjects (10), this makes the identification of type 2 diabetic patients with a higher risk to vascular disease is a priority need. in this study, type 2 diabetes j bagh college dentistry vol. 28(2), june 2016 periodontitis among pedodontics, orthodontics and preventive dentistry 117 mellitus patients who were diagnosed by arterial stiffness index with higher vascular disease risk proved to have higher periodontal disease parameters including: gingival index, probing pocket depth, and clinical attachment level. these results are in compatible with various studies reported a relation between prevalence and severity of non-oral diabetes-related complications, including cardiovascular disease complications with the severity of periodontitis (19,20). in conclusion, the increase in severity of periodontitis in type 2 dm patients is an indicator of risk for vascular disease, and these patients will be priority target for any preventive program conducted to protect them from vascular disease outcome leading to a decrease in morbidity and mortality of type 2 dm patients. table 1: clinical characteristics of type 2 diabetic patients according to arterial stiffness index (asi) in comparison with controls variables study groups anova-test lsd-test p-value control mean ±sd n=50 group a mean ±sd n=50 group b mean ±sd n=50 fvalue pvalue control vs. group a control vs. group b group a vs. group b age (year) 50.6±3.50 50.42±3.70 51.88±3.72 3.50 0.033 0.62 0.014 0.047 bmi 27.97±4.59 28.81±5.23 28.59±2.25 0.52 0.593 0.326 0.465 0.800 t-test p-value duration of dm (year) 6.90±4.45 8.58±4.14 0.274 table 2: clinical periodontal parameters of type 2 diabetic patients according to arterial stiffness index (asi) in comparison with controls variables study groups anova-test lsd-test p-value control mean ±sd n=50 group a mean ±sd n=50 group b mean ±sd n=50 f-value p-value control vs. group a control vs. group b group a vs. group b pli 1.45±0.82 1.32±0.79 1.40±0.61 0.36 0.697 0.399 0.728 0.619 ci 0.87±0.54 0.99±0.61 1.02±0.43 1.18 0.310 0.262 0.144 0.732 gi 1.18±0.78 1.51±0.53 1.62±0.67 5.81 0.003 0.014 0.001 0.419 ppd 2.18±0.53 2.63±0.54 3.10±1.11 17.38 0.000 0.004 0.000 0.003 cal 2.57±1.27 3.44±1.29 4.05±1.68 13.73 0.000 0.003 0.000 0.033 references 1. preshaw pm, alba al, herrera d, jepsen s, konstantinidis a, makrilakis k, taylor r. periodontitis and diabetes: a two-way relationship.diabetologia 2012; 55:21–31. 2. kornman ks. mapping the pathogenesis of periodontitis: a new look. j periodontol2008; 79:15608. 3. mansour aa, abd-al-sada n. periodontal disease among diabetics in iraq. medscape general medicine 2005; 7:2. pmid: 16369228. 4. abass vt, omer sa. oral findings and microflora in type ii diabetes mellitus in sulaimani city.jsmc 2011; 1(1):13-28. 5. kumar a, pandey mk, singh a, mittra p, kumar p.prevalence and severity of periodontal diseases in type 2 diabetes mellitus of bareilly region (india). international journal of medical science and public health 2013; l 2 (1): 77-83. 6. apoorva s m, sridhar n, suchetha a. prevalence and severity of periodontal disease in type 2 diabetes mellitus (non–insulindependent diabetes mellitus) patients in bangalore city: an epidemiological study. j indian socperiodontol2013; 17(1): 25-9. 7. jimenez m, krall ea, garcia r i, vokonas p s, dietrich t. periodontitis and incidence of cerebrovascular disease in men. annals neurol 2009; 66: 505–12. 8. xu f y, lu b. prospective association of periodontal disease with cardiovascular and all-cause mortality: nhanes iii follow-up study. atherosclerosis 2011; 218: 536–542. 9. chrysanthakopoulos na, chrysanthakopoulos pa. clinically classified periodontitis and its association in j bagh college dentistry vol. 28(2), june 2016 periodontitis among pedodontics, orthodontics and preventive dentistry 118 patients with preexisting coronary heart disease. hindawi publishing corporation; j oral dis 2013, article id 243736. 10. laakso m, lehto s. epidemiology of macrovascular disease in diabetes. diabetes rev 1997;5:294–315. 11. kaibe m, ohishi m, komai n, ito n, katsuya t, rakugi h, ogihara t. arterial stiffness index: a new evaluation for arterial stiffness in elderly patients with essential hypertension. geriatrics and gerontology international 2002; 2: 199–205. 12. altunkan s, oztas k, seref b. arterial stiffness index as a screening test for cardiovascular risk: a comparative study between coronary artery calcification determined by electron beam tomography and arterial stiffness index determined by a vitalvision device in asymptomatic subjects. eur j internal medicine 2005; 16: 580 – 4. 13. mars medical products co.,ltd. vital vision user’s guide, 2009. http://www. mars.com.tw. 14. silness j, loe h. periodontal disease in pregnancy. correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22: 121-35. 15. ramfjord sp. indices for prevalence and incidence of periodontal disease. j periodontol 1959; 30:51-9. 16. loe h, silness j. periodontal disease in pregnancy. acta odontol scand 1963; 21:533-51. 17. zielinski mb, fedele d, forman lj, pomerantz sc. oral health in the elderly with noninsulindependent diabetes mellitus. spec care dentist 2002; 22(3):9498. 18. borges-yanez sa, irigoyen-camacho me, maupomé g. risk factors and prevalence of periodontitis in community-dwelling elders in mexico. j clin periodontal 2006;33:184-94. 19. saremi a, nelson rg, tulloch-reid m. periodontal disease and mortality in type 2 diabetes. diabetes care 2005; 28:27–32. 20. li q, chalmers j, czernichow s, neal b, taylor b, zoungas s, poulter n, woodward m, patel a, galan b, batty d.oral disease and cardiovascular disease in people with type 2 diabetes: prospective cohort study based on the advance trial. diabetologia2010; 53: 2320–7. zainab final.doc j bagh college dentistry vol. 26(3), september 2014 nugget mechanical orthodontics, pedodontics and preventive dentistry 169 nugget mechanical properties of combination (rectangular and round) welded and soldered stainless steel wires zainab m. hasan, b.d.s. (1) fakhri a. ali, b.d.s., m.sc. (2) abstract background: this study aimed to compare the mechanical properties between four groups of newly fabricated combination wires according to their method of union, according to the gauges of wires and a comparison were made between them and their originals. materials and method: a total of 60 stainless steel combination wires were fabricated , divided into four groups according to gauge of wires and their method of union, each of them with 15 samples, the groups were welded (0.016x0.022-0.016 and 0.016x0.022-0.018) and soldered (0.016x0.022-0.016 and 0.016x0.022-0.018), samples were made according to certain parameters which were : for the welded samples: length,weight, duration of pulsation and size of copper electrode tips used; for the soldered samples: length, weight, distaince from the heat source and duration of heat application results: the descriptive statistics showed that the maximum value for ultimate force and ultimate tensile strength was for the soldered 0.016x0.022+0.018 inches combination wires, while the minimum was for the welded 0.016x0.022+0.016inches wires. elastic modulus showed higher values for the soldered 0.016x0.022+0.016 and resiliency values for the welded 0.016x0.022+0.016 were the highest. comparison between combination wires and their originals showed a decrease in the mechanical properties after soldering and welding. conclusion: higher gauge wires and soldering method of union showed better mechanical properties than the other groups and both soldering and welding method showed changes in the mechanical properties of the newly fabricated wires when comparing them with their originals. keywords: archwire, stainless steel, combination wires, soldering and welding. (j bagh coll dentistry 2014; 26(3):169173). الخالصھ األسالك وتم إجراء مقارنة بینھا لقیاساتاالتحاد،وفقا في وفقا لطریقتھم المركبھ تھدف ھذه الدراسة إلى المقارنة بین الخواص المیكانیكیة بین أربع مجموعات من األسالك : المقدمة .االسالك االصلیھوبین عینة، 15 یتكون من، كل واحد منھم ةاللحاماألسالك وطریق لقیاساتالى أربع مجموعات وفقا قسمت قاوم للصدأ ، الفوالذ المسلك مصنوع من مادة 60 من مجموعھ: والطریقھالمواد االقطابنبض وحجم نحاس االمدة والطول، الوزن،: والتي كانت الضوابطوفقا لبعض ) 0.022x0.016+0.018و 0.022x0.016+ 0.016(لحم االسالك ذات القیاسات التالیھ تم ).للعینات الملحومھ عن طریق الحراره( ومدة عملیة اللحام والبعد من مصدر الحراره )بلنسبھ للعینات الملحومھ عن طریق التیار الكھربائي(تخدمة المس عالیة بالمقارنة مع العینات االخرى االقل قیم ) 0.018-0.022× 0.016( أظھرت النتائج للقوه القصوى المحتملھ ولقوة الشد القصوى للعینات الملحومھ عن طریق الحراره :النتائج قیم عالیھ بلمقارنھ مع العینات االخرى ) 0.016-0.022× 0.016( للعینات الملحومھ عن طریق الحراره و اظھرت نتائج معامل المرونھ, حجما والملحومة عن طریق التیار الكھربائي ) 0.0160.022× 0.016( ائج معامل الطاقھ المخزونھ فقد اظھرت قیم عالیھ للعینات الملحومھ عن طریق التیار الكھربائي اما نت, االكبر حجما الملحومھ عن طریق التیار الكھربائي .وقد لوحظ انخفاضا في الخواص المیكانیكیھ عند مقارنة االسالك المركبھ مع االسالك االصلیة قبل اللحیم الخالصة مع النسخ األصلیة االسالك الجدیده ةمقارنمیكانیكیة أفضل من المجموعات األخرى وعلى حد سواء عند اخواص عن طریق الحراره حامأسلوب لو علىاألقیاس ذات ال أظھرت األسالك .الجدیدهبلنسبھ لالسالك المركبھ اظھرت النتائج انخفاضا في الخواص المیكانیكیھ الخاصة بھم .لحام بطریقتینأسالك الجمع، ، الفوالذ المقاوم للصدأ، سلك تقویم: الكلمات الرئیسیة introduction one of the most common methods oftranslating a tooth orthodontically is by the use of sliding mechanics. inthis technique, mesiodistal tooth movement is accomplished by guidinga tooth along a continuous archwire with the use of an orthodontic bracket. adisadvantage of this technique is thatfriction is generated between the bracketand the archwire, which tends to resist themovement of the bracket and tooth in thedesired direction (1).one of the primary focuses of the ideal conditions for orthodontic tooth movement (otm) is the reduction of friction at the bracket-wire-ligature interface in certain stages of treatment (2). (1) master student. department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. the friction present during orthodontic sliding mechanics represents a clinical challenge to the orthodontists because high levels of friction may reduce the effectiveness of the mechanics, decrease tooth movement efficiency and further complicate anchorage control(3). therefore, lower but still sufficient to promote otm forces could be used (3) when the wire dimension was increased from "0.016×0.022" stainless steel to "0.017×0.025" stainless steel, friction increased. frictional force was directly proportional to the wire size (4). to solve this problem a combination archwire composed from anterior segment rectangular to prevent tipping and posterior segment round to allow anterio posterior bodily movement & tipping in bucco-palatal dimension and facilitate the canine retraction were needed. joining different diameter wires is used to obtain the desired moment differential rather than utilizing j bagh college dentistry vol. 26(3), september 2014 nugget mechanical orthodontics, pedodontics and preventive dentistry 170 spring positioning (5). stainless steel can be fused together by welding but this generally required reinforcement with solder (6,7) soldering defined as the joining of metals by the fusion of intermediary alloys which are of a lower melting point. the lower fusing metals or solder, is fused to the parts to be joined. welding: the welding process employed by the orthodontist is known as resistance welding or spot welding. the two pieces to be welded are held under pressure and an electric current is applied for a given period of time. the electrical resistance of the juncture of the two parts causes a rise in temperature and a localized fusion of the metal parts occurs (8). materials and methods a total of sixty stainless steel combination wires were prepared, thirty of them united by soldering group and the other thirty united by welding method group, in each group samples were equally divided into two sub-groups according to the sizes of wires used which were: (0.016×0.022+0.016) inches,(0.016×0.022+0.018) inches, the ultimate force, ultimate tensile strength of nugget area (joints) were tested by universal testing machine, elastic modulus and resiliency were calculated by special equations. samples were prepared according to specific parameters which were: length, weight and for (soldered samples) the distance from heat source and time of heat application. for the welding method fifteen samples were prepared for each gauge of straight stainless steel wires, a combination of 0.016 inch with 0.016×0.022 inch and combination of 0.018 inch with 0.016×0.022 inch, which means that the number of the welded sample were 30 (thirty),each piece of wire (4 inch in length) is bended at right angle for (0.4 inches) to increase welded surface area, joints made in this way are stronger than those made with wires laid parallel according to (9), and then fixed by hand with the other piece in the welding machine, then four electrical pulsations were made (the duration of each pulsation was 1/25 second). for the soldering method, fifteen samples were fabricated for each gauge of straight stainless steel wires, a combination of 0.016 inch with (0.016×0.022) inches and combination of (0.018) inches with (0.016×0.022) inches, before starting the soldering procedure each sample were welded with two electrical pulsations (the duration of each pulsation was 1/25 second) only to ensure fixation of the sample during soldering, then a plaster of pairs were mixed and applied to the combination wire around the nugget area to prevent transfer of heat to the rest of the wire, wires were fixed on a customized cartoon board stand to grasp the wire during soldering procedure. orthotechnology silver solder and flux were used for soldering all joints. the joint site was adequately heated with the reducing zone of the flame (piezo gas burner2000, japanese) and as soon as the site reached solder flow temperature, 6 mm of the solder was held in a tweezer and introduced at the joint site. the work were held 3mm beyond the tip of the blue cone in the reducing zone of the flame, soldering were observed in a shadow, against a black back ground, so that the temperature can be judged by the color of the work. the color should never exceed a dull red. solder were added and heating were continued until metal flows around the joint. the flame was withdrawn when the solder had flown over the joint site in a feather edge configuration. all specimens were immediately quenched in cold water as recommended by (10).the flame were applied nearer to the rectangular wire than the round wire because rectangular wire tolerance to heat is greater than the round wire (to avoid unwanted annealing effect to the wire). the universal testing machine (tinius olsen/ model 50km with a capacity of 50kn) was standardized to grasp the combination wire firmly in a vertical way by mounting wires into capstan grips with a nip-to-nip distance of 4 inches for fixation of the samples. the test include: ultimate force and ultimate tensile strength, both of these values were calculated by testing machine, special software which calculate the ultimate force first, then by entering the diameter of the round wire it would calculate the ultimate tensile strength of the wires, during the test of welded wires the cutting were made in the nugget area (area of contact), for the soldered wires sample the cutting were made in the round wire part. elastic modulus values were obtained by dividing a stress value equal to or less than the proportional limit by its corresponding strain value. e modulus =stress/strain. (11) units of elastic modulus is gigapascal (gpa) modulus of resilience was obtained from the following equation: r=p2/2e (12). statistical analysis descriptive statistics, including the mean, standard deviation, minimum and maximum values were calculated for each group of combination wires. inferential statistics include independent sample t-test to compare the j bagh college dentistry vol. 26(3), september 2014 nugget mechanical orthodontics, pedodontics and preventive dentistry 171 mechanical properties (ultimate force, ultimate tensile strength, elastic modulus, resiliency) between the wires in each method of union and between the methods of union for each wire, one sample t-test to compare the mechanical properties of the combination wires with their originals, paired sample t-test for intra and interexaminer calibration. the statistical analyses were carried out using pentium iv computer and the statistical package of social science spss program version 19, running under microsoft windows. data were analyzed by using, version 19). the following levels of significance were used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 * significant 0.01 ≥ p > 0.001 ** highly significant p= probability value. results the descriptive statistics showed that soldered (0.016×0.022+0.018) wires gave rise to highest values of force and ultimate tensile strength when compared with welded (0.016×0.022+0.016) inches wires which gave rise to the lowest values, while for the elastic modulus descriptive statistics showed highest values for soldered (0.016×0.022+0.016) inches, resiliency showed highest values for the welded (0.016×0.022+0.016) inches. comparison of significance by using independent sample t-test between sizes of wires and methods of union for the ultimate force measure showed a highly significant difference p<0.01 for (0.016×0.022-0.018) inches wires when compared with (0.016×0.022+0.016) inches,nonsignificant difference for the ultimate tensile strength, highly significant for the elastic modulus and highly significant for the resiliency. comparison was done using independent sample t-test between methods of union showed highly significant between soldering and welding methods of union for all mechanical properties. comparison of significance between combination wires and their originals by using one sample ttest showed highly significant difference between them for all mechanical properties. table 1: descriptive statistics demonstrate ultimate force values of different orthodontic wires combinations method of union wires descriptive statistics wires comparison df=28 mean s.d. s.e. min. max. t-test p-value soldering 16×22-16 138.70 27.01 6.97 106.70 186.50 -3.31 0.003 (hs) 16×22-18 181.49 42.13 10.88 126.50 276.50 welding 16×22-16 94.91 17.41 4.49 53.30 118.50 -2.52 0.018 (s) 16×22-18 110.78 17.08 4.41 80 135 table 2: descriptive statistics demonstrate ultimate tensile strength values of different orthodontic wires combinations method of union wires descriptive statistics wires comparison df=28 mean s.d. s.e. min. max. t-test p-value soldering 16×22-16 1104.08 215.30 55.59 849 1484 -0.42 0.677(ns) 16×22-18 1141.20 265.00 68.42 795 1739 welding 16×22-16 755.33 138.51 35.76 424 943 1.29 0.205(ns) 16×22-18 696.60 107.47 27.75 503 849 table 3: descriptive statistics demonstrate elastic modulus values of different orthodontic wires combinations (gpa) method of union wires descriptive statistics wires comparison df=28 mean s.d. s.e. min. max. t-test p-value soldering 16×22-16 143.54 19.48 5.03 110.50 182.60 2.87 0.008 (hs) 16×22-18 117.32 29.55 7.63 66.70 173 welding 16×22-16 122.47 17.04 4.40 90 149 0.39 0.694 (ns) 16×22-18 119.27 26.04 6.72 88.30 193 j bagh college dentistry vol. 26(3), september 2014 nugget mechanical orthodontics, pedodontics and preventive dentistry 172 table 4: descriptive statistics demonstrate resilience values of different orthodontic wires combinations method of union wires descriptive statistics wires comparison df=28 mean s.d. s.e. min. max. t-test p-value soldering 16×22-16 1 0.38 0.10 0.44 1.79 0.45 0.66 (ns) 16×22-18 0.94 0.33 0.09 0.51 1.58 welding 16×22-16 1.31 0.28 0.07 0.69 2 3.83 0.001 (hs) 16×22-18 0.89 0.32 0.08 0.47 1.65 discussion in this current study which involved heat application (soldering) and electrical current (welding), involved melting of the parts to be welded, it is unfortunate that a stainless steel orthodontic wire can become annealed, in different percentages, resulting in a recrystallized microstructure in a few seconds at temperatures from 700 c˚ to 800°c, which lie within the soldering and welding temperature range. this disadvantage can be minimized by using lowfusing solders, and by confining the time for soldering and welding procedures to a minimum. it is important that the stainless steel wire not be heated to too high a temperature, in order to minimize carbide precipitation, and to prevent an excessive softening of the wire so that its usefulness is lost. wires of same thickness present no problem in soldering but if one wire is much thinner than the other, care must be taken not to overheat the finer wire. thinner wire may be wound round a thicker wire before soldering as this makes a very strong joint (13). the higher and more prolonged the welding temperatures, the greater will be the carbide precipitation, even though there was no carbide precipitation, a tendency to tarnish and corrode would be present because of the differences in grain structure brought about by the welding(8). independent sample t test showd highly significant difference between the two gauges of combination wires for the ultimate force with highest values for the large gauge because heat treatment is a quantitative factor, wires of smaller diameter will absorb heat more quickly than will a larger wire, non-significant for the ultimate tensile strength measure because ultimate tensile strength gave rise to higher values when the force divided on the less surface area and less value when force divided on higher surface area this may cause a non-significance between the two gauges. elastic modulus and resiliency were higher for the smaller gauge wiresthis could be explained by the fact that the lower gauge wires could be elastically deformed more than the higher gauge wires, the smaller the wire, the more it can be deflected without permanent deformation (14), and the area under the stressstrain curve for the elastic modulus was greater for the lower gauge wires. comparison of significance between methods of union showed highly significant difference between soldering and welding with better properties for the soldering method because electrical resistance or spot welding of stainless steel causes melting and solidification of the alloy with localized loss of the wrought microstructure and increased stress in the surrounding heataffected zone where joint failure is most likely to occur. (15), spot welding is carried out without the aid of flux or any other protecting material so that as the temperature of the work pieces is raised, oxidization and breakdown of the composition of materials which are alloys can occur, which will produce weakness in the weld. (9). when comparing the significance between combination wires and their originals by using one sample t-test showed highly significant difference between them because when the solder is overheated to a temperature of 815 c˚. (1500 f˚). the diffusion of the solder into the grain boundaries becomes evident from the wire to the solder and from the solder to the wire, the composition of both the solder and the alloy has been changed with the result that mechanical properties of the joint are no longer under the control of the operator, in addition to the changes which accompanied the welding procedure which were mentioned previously. as conclusions: 1. higher gauge wires produced better mechanical properties than lower gauge. 2. soldering method produced fewer changes in the mechanical properties than welding (produce stronger joints than welded nugget). 3. there is a significant difference in mechanical properties between original wires before soldering and welding and the combination wires after soldering and welding. 4. both soldering and welding method of union produce changes in the microstructure of wires in different way (the welding produce more changes and weaken the joints), which will j bagh college dentistry vol. 26(3), september 2014 nugget mechanical orthodontics, pedodontics and preventive dentistry 173 give rise into changes in their mechanical properties. 5. combination wires produced by soldering method could be employed clinically for retraction cases because of their better mechanical properties than those produced by welding method. references 1. bednar jr, gruendeman gw, sandrik jl. a comparative study of frictional forces between orthodontic brackets and archwires. am j orthod dentofac orthop 1991; 100(6): 513-22. 2. pizzoni l, ravnholt g, melsen b. frictional forces related to self-ligating brackets. eur j orthod 1998; 20(3): 283-91. 3. rossouw ep. friction: an overview. semin orthod 2003; 9(4):218-22. (ivsl) 4. husain n, kumar a. frictional resistance between orthodontic brackets and archwire: an in vitro study. j contemp dent pract; 2011:12(2):91-99. 5. nanda r, kuhlberga. biomechanics in clinical orthodontics. 1st ed. st. louis: w.b. saunders company; 1997. 6. kapila s, sachdeva r. mechanical properties and clinical application of orthodontic wires. am j orthod dentofac orthop 1989; 96(2): 100-9. 7. krishnan v, kumar kj. weld characteristics of orthodontic archwire materials. angle orthod 2004; 74(4):533-8. 8. skinner we, phillips wr .the science of dental material. 5th ed. america. w.b. saunder's company press; 1960. 9. adams cp. the design, construction and use of removable orthodontic appliances. 5th edition. england: wright; 1984. 10. philips rw. physical properties of dental materials: skinners science of dental materials. 9th ed. philadelphia. w.b. saunders company; 1991. 11. ronald ls, john mp. craig's restorative dental materials, 3rd ed. philadelphia: mosby; 2012. 12. van noort r. introduction to dental materials. 2nd ed. hong kong: mosby; 2002. 13. sharmila h. textbook of dental materials. 1st ed. india: gopsons paper ltd noida; 2004. 14. graber tm, xubair, vig, vanarsdall rl. orthodontics current principles and techniques. 5th ed. st. louis: mosby; 2012. 15. willems gk, clocheretjp, celis g, verbeke, chatzicharalampous e, carels c. frictional behavior of stainless steel bracketwire combinations subjected to small oscillating displacements. am j orthod dentofac orthop 2001; 120(4): 371-7. j bagh college dentistry vol. 25(1), march 2013 effect of post-pressing restorative dentistry 1 effect of post-pressing times on adaptation of maxillary heat cured acrylic denture base at posterior palatal seal area firas a. farhan, b.d.s., m.sc. (1) abstract background: the purpose of this study was to verify the influence of postpressing time of acrylic resin (immediate, 6, 12 and 24 hour) on the dimensional accuracy of denture base whish is a critical factor in the retention and stability of the complete denture that may occur during polymerization shrinkage. materials and methods: forty maxillary stone casts were poured in plastic mold (columbia dentoform corp. new york, type iii dental stone (geastone, zeus sri loc.tamburine roccastrada, gr, italy). the stone casts were randomly assigned into 4 groups of 10 specimens each according to the post-pressing times into (immediate, 6, 12 and 24 h.). heat cure acrylic resin denture base was constructed according to the previously mentioned pressing time, the resin base-stone cast sets were transversally sectioned with a manual saw device at the distal aspect of the molar area, anterior to the posterior palatal seal area. the gap between the resin base and stone cast was measured at five points in the right (point b) and left (point d) ridge crests, at the midline (point c), and at the right (point a) and left (point e) marginal limits (a), using a leitz linear optical comparator microscope with a travelling stage capable of measuring 0.001 mm. each measurement was repeated three times and the average was used as the linear gap distance for that point. the data were submitted to anova. result: there was statistically significant difference between the pressing time in which the mean values of gap space in point e for 24h shows lowest value then point a, point b, and point d than the other post pressing time. the mean value in point c shows highest values which mean the greater gap space in palatal area. keywords: dimensional change, denture base, post-pressing time. (j bagh coll dentistry 2013; 25(1):1-4). introduction the dimensional changes that may occur in denture base influence on the retention and stability of complete denture this change may be partially compensated by water absorption (1), by the resilience of the gingival mucosa (2), and the saliva film formed between the resin base and the soft support tissue (3,4). in addition, the base is also responsible for artificial teeth fixation and distribution of chewing forces over the tissuebearing area, and other factors may influence the base dimensional stability, such as the resinflasking method and the time-temperature correlation during the curing methods (5). the combination of several factors such as polymerization shrinkage, thermal contraction by flask cooling, and strain caused by stress release during deflasking causes diminished adaptation of the denture to the tissue. the inaccuracy in the flange area may also cause instability and pressure points on the soft tissues, and the greatest effect of linear shrinkage is usually on the posterior palatal region of the maxillary denture, resulting in a gap between this area and the denture (6-7). therefore, the discrepancy between the base and supporting tissues is an important factor in the control of the amount of force necessary to dislodge the dentures (8,11,). (1)assistant lecturer. department of prosthodontics. college of dentistry. university of baghdad. material and methods forty maxillary edentulous stone casts were prepared from an edentulous silicon mold (columbia dentoform corp. new york,). the mold was poured with type iii dental stone (geastone, zeus sri loc.tamburine roccastrada, gr, italy) using a ratio of 30 ml water to 100 g powder according to manufacturer instruction. the stone casts were randomly assigned into 4 groups of 10 specimens each according to the post-pressing times into immediate, 6, 12 and 24 h. a uniform denture base plate was prepared by using biostar machine (3). the biostr plate (2mm thickness) then sealed with wax on the cast, this procedure was repeated for all the cast samples (1). the cast with corresponding denture base was flasked in the lower half of a traditional brass flask with (1:1) plaster: stone mixture as investing material (2). the first allowed to dry, then separating medium was painted for all the exposed stone surfaces. the upper half of flask was fitted on the lower half and second plaster: stone mixture was poured. the wax elimination procedure was proceeding and the denture base removed. separating medium was applied on the surface of investing material and stone samples. classic poly methyl methacrylate pmma was used with monomer: polymer ratio of 1:3 (by volume) according to manufacturer instructions. the prepared dough was packed according to one of the post-pressing times. the flask were transferred to a flask carrier or clamp and immersed in water according to the post-pressing times. after the curing cycle, the flasks were j bagh college dentistry vol. 25(1), march 2013 effect of post-pressing restorative dentistry 2 removed and allowed to bench cool then, the mold investment was removed while the cast with its denture base where the deflasked after 24 hr to be trimmed and fixed to their corresponding casts with instantaneous adhesive (2 drops on the premolar area) in order to prevent any movement during cutting procedure. determination of the cutting line which was (39 mm) from anterior aspect of the base of the cast (where the whole length of the cast was 52mm) (3, 12). the resin base-stone cast sets were transversally sectioned with a manual saw device at the distal aspect of the molar area, anterior to the posterior palatal seal area (3 ) . the gap between the resin base and stone cast was measured at five points in the right (point b) and left (point d) ridge crests, at the midline (point c), and at the right (point a) and left (point e) marginal border (figure 1). using a leitz linear optical comparator microscope with a travelling stage capable of measuring 0.001 mm. each measurement was repeated three times and the average was used as the linear gap distance for that point. the measurements were made at 5 points for each one (4). figure 1. points in the transverse section used to determine the dimensional changes in the base-stone set. results the mean values gap space was classified according to the point of transversally sectioned of each resin base-stone cast for each post pressing time (point a for right marginal border, point b for right ridge crest, point c for mid palatal point, point d for left ridge crest, point e for left marginal ridge). table 1: descriptive statistics of the mean gap space in point {a} and p-value for groups of immediate, 6 hour, 12 hour, and 24 hour. post pressing time mean mm s.d f-test pvalue immediate 0.208 0.0487 12.406 0.039 6 hour 0.188 0.0266 12 hour 0.165 0.0227 24hour 0.141 0.0202 table 2: descriptive statistics of the mean gap space in point {b} and p-value for groups of immediate, 6 hour, 12 hour, and 24 hour. post pressing time mean mm s.d t-test pvalue immediate 0.207 0.0327 12.508 0.038 6 hour 0.175 0.0378 12 hour 0.172 0.022 24hour 0.146 0.0291 table 3: descriptive statistics of the mean gap space in point {c} and p-value for groups of immediate, 6 hour, 12 hour, and 24 hour. post pressing time mean mm s.d ftest pvalue immediate 0.535 0.028 9.193 0.049 6 hour 0.525 0.0341 12 hour 0.507 0.0395 24hour 0.494 0.0401 table 4: descriptive statistics of the mean gap space in point {d} and p-value for groups of immediate, 6 hour, 12 hour, and 24 hour. post pressing time mean mm s.d f-test pvalue immediate 0.203 0.0236 12.463 0.039 6 hour 0.195 0.0357 12 hour 0.181 0.026 24hour 0.149 0.0277 table 5: descriptive statistics of the mean gap space in point {e} and p-value for groups of immediate, 6 hour, 12 hour, and 24 hour. post pressing time mean mm s.d f-test pvalue immediate 0.214 0.0502 12.289 0.029 6 hour 0.197 0.0258 12 hour 0.174 0.0246 24hour 0.139 0.0274 table 6: lsd of multiple comparison tests between immediate & 6 hours tested groups at all point. point of sectioned t-test p-value sig a 1.168 0.229 ns b 1.599 0.145 ns c 0.318 0.588 ns d 0.314 0.513 ns e 0.144 0.243 ns j bagh college dentistry vol. 25(1), march 2013 effect of post-pressing restorative dentistry 3 table 7: lsd of multiple comparison tests between immediate & 12 hours tested groups at all point. point of sectioned t-test p-value sig a 6.611 0.033 s b 6.248 0.035 s c 4.186 0.041 s d 3.176 0.041 s e 5.139 0.042 s table 8: lsd of multiple comparison tests between immediate & 24 hours tested groups at all point. point of sectioned t-test p-value sig a 31.04 p<0.01 hs b 21.07 p<0.01 hs c 18.957 0.005 hs d 15.584 0.001 hs e 15.109 0.001 hs table 9: lsd of multiple comparison tests between 12 hours & 24 hours tested groups at all point. point of sectioned t-test p-value sig a 8.881 0.012 s b 4.043 0.043 s c 0.103 0.451 ns d 6.891 0.018 s e 7.295 0.023 s discussion post-pressing time seems to be effective in promoting resin mass relaxation, and probably a possible technical condition to be applied to the laboratory routine. the suggested reason for allowing the flask to stand for some hours before polymerizing is to allow the resin mass to flow into all regions of the mold (5, 10). in the present study, the immediate and 6-hour delayed time showed no statistically significant difference in gap space as shown in (table 6) when compared with the 12h and 24h which showed significant differences as shown in (table 7). this result indicated that when the post pressing time increase the gap space decrease, especially when compared between the immediate and 24 hours which showed highly significant difference as shown in (table 8). due to resin mass to stay for a longer delayed time before polymerization this procedure probably also reduces the amount of residual monomer present in the resin dough by evaporation (15,16). the largest base dimensional changes are observed in the denture posterior palatal seal because the edentulous maxilla consists of a relatively flat portion in the middle of the hard palate and an inclined slope toward residual ridge. due to this geometric feature of the palatal concavity configuration the shrinkage occurring toward the residual ridge leads to lifting of the denture base in mid-palatal region (9, 13). the differential in thermal contraction between the mold and the acrylic resin is believed to be the cause of residual strain in the processed denture and also considered to be the main contributor in strain release which occurs when the denture is separated from the cast (7, 14). testing the fit changes at the marginal borders significant differences where noticed among tested groups at both a and e points respectively, which may be attributed to the large horizontal force component resulting from force analysis at the ridge crest, so larger amounts of stresses may be generated at the marginal borders rather than the ridge crests leading to larger strains after denture deflasking. these valuable amounts of stresses may create general differences among tested groups (8, 17). reference 1. negreiros wa, consani rlx, mesquita mf, sinhoreti mac, faria ir. effect of flask closure method and post-pressing time on the displacement of maxillary denture teeth. the open dentistry j 2009; 3: 21-5. 2. consani rlx, domitti ss, mesquita mf, consani s. effect of packing types on the dimensional accuracy of denture base resin cured by the conventional cycle in relation to post-pressing times. braz dent j 2004; 15(1): 63-7. 3. abdul-khalik hk. effect of different packing methods, silinated glass fiber incorporation and cocr framework involvement on the fit of acrylic denture base at the posterior palatal region. a master thesis, department of prosthodontics. university of baghdad, 2009. 4. yeung kc, chow tw, clark rkf. temperature and dimensional changes in the two-stage processing technique for complete dentures. j dent 1995; 23: 245-53. 5. anusavice kj. phillips’science of dental materials. 10th ed. philadelphia: wb saunders; 1996. pp.243. 6. sykora o, sutow ej. improved fit of maxillary complete denture processed on high tension stone casts. j prosth dent 1997; 34:11-15. 7. chen jc, lacefield wr, cattberry dj. effect of denture thickness and curing cycle on the dimensional of acrylic resin denture bases. dent mater 1988; 4: 20-4. 8. komiyama o, kawara m. stress relaxation of heat activated acrylic denture base resin in the mold after processing. j prosth dent 1998; 79: 175-81 9. teraoka f, nakagawa m, takahashi j. adaptation of acrylic dentures reinforced with metal wire. j oral rehab 2001; 28: 937-42. 10. consani r lx, mesquita m f, sobrinho lc, sinhoreti mac. effect of metallic flask closure and investment materials on the stability of the denture base resin. j appl polymer sci 2010; 116: 1467-74. j bagh college dentistry vol. 25(1), march 2013 effect of post-pressing restorative dentistry 4 11. darvell bw, clark rkf. the physical mechanism of complete denture retention. br den j 2000; 189: 248-52. 12. hussein ya, al-ameer ss. the influence of different ph of saliva and thermal cycling on the adaptation of different denture base materials. j bagh college dentistry 2012; 24(3): 47-53. 13. al-tarakemah y. effect of ridge shape on the fit of denture base. a master thesis, department of prosthodontics. university of florida, 2007. 14. pasam n, hallikerimath rb, arora a, gilra s. effect of different curing temperature on the distortion at the posterior peripheral seal. ind j den sea 2012; 23(3): 301-4. 15. moussa ara, zaki dyi, elgabry hs, ahmed tm. comparative adaptation accuracy of heat cured and injection molded resin denture base materials. j appl sci res 2012; 8(8): 4691-6. 16. consani rlx, domitti ss, rizzattibarbosa cm, consani s. effect of commercial acrylic resin on dimensional accuracy of the maxillary denture base. braz dent j 2002; 13(1): 57-60. 17. arora s, sangur r, dayakra hr. comparative evaluation of the fit of maxillary complete denture bases at the posterior palatal border made by heat cure acrylic resin processed on high expansion stone. jida 2011; 5: 12-14. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p): 1817-1869, issn (e): 2311-5270 52 research article molecular detection of porphyromonas gingivalis in covid-19 patients haifa hmood kareem1, batool hassan al-ghurabi1, cinaria albadri 2 1 department of basic science, college of dentistry, university of baghdad, iraq. 2 department of clinical medicine, trinity college dublin university, ireland. * correspondence: batoolamms@yahoo.com abstract: background:sars-cov-2 infection has caused a global pandemic that continues to negatively impact human health. a large group of microbial domains including bacteria co-evolved and interacted in complex molecular pathogenesis along with sars-cov-2. evidence suggests that periodontal disease bacteria are involved in covid-19, and are associated with chronic inflammatory systemic diseases. this study was performed to investigate the association between bacterial loads of porphyromonas gingivalis and pathogenesis of sarscov-2 infection. fifty patients with confirmed covid-19 by reverse transcriptase-polymerase chain reaction, their age ranges between 20-76 years, and 35 healthy volunteers (matched accordingly with age and sex to the patients) participated in this case control study. oral hygiene status was determined by the simplified oral hygiene index. blood and saliva samples were obtained from patients and controls, porphyromonas gingivalis quantification from extracted dna of blood and saliva samples performed by means of real-time polymerase chain reaction. the present result revealed that the quantity of salivary porphyromonas gingivalis was significantly higher (p=0.003) in the patients’ group than in the controls group, while there was no significant difference in the number of bacteria in the blood samples between the two groups. moreover, the number of bacteria in severe cases was higher than that in moderate and mild with no significant differences, and there was a significant increase in the number of bacteria among patients with poor oral hygiene compared to patients with good oral hygiene. this study demonstrated that the high level of salivary porphyromonas gingivalis in patients increases in number with disease severity, which may indicate that bacterial infections contribute to the spread of the disease. keywords: covid-19, porphyromonas gingivalis, co-infection. introduction covid-19 caused by sars-cov-2, has affected most countries all over the world since its first case in end of 2019. the genomic characteristics of sars-cov-2 was initially reported by lu and colleagues, suggesting this coronavirus had enveloped rna, resembling severe acute respiratory syndrome coronavirus (sars-cov) in both structural and homological ways1. during this covid-19 attack, besides the primary infection of sars-cov-2, many other complications are emerging, contributing greatly to the mortality. among these, co-infection plays a crucial role, threatening many covid-19 patients’ lives 2. as reported by researchers, the prevalence of co-infection was variable, being found occurred in half of the non-survivors3. the pathogens of respiratory co-infection could be many, either common or rare, including bacteria, virus, fungus, etc. bacteria were reckoned to be one of the most commonly isolated4. poor oral hygiene is considered to be a major ecological shift that steers complex microbial communities in the mouth to dysbiosis. ecological shifts in a dysbiotic ecosystem favour an increased prevalence of pathogenic oral bacteria. daily activities such as mastication, flossing and tooth brushing can induce bacteraemia, which facilitate haematogenous dissemination of oral bacteria and inflammatory mediators inducing received date: 15-1-2022 accepted date: 22-3-2022 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/) https://doi.org/10.26477/jbcd .v34i2.3145 mailto:batoolamms@yahoo.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i2.3145 https://doi.org/10.26477/jbcd.v34i2.3145 j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 53 systemic inflammation in some patients. individuals with periodontal disease show micro-ulcerated sulcular epithelia and damaged periodontal tissues, and thus seem more susceptible to bacteraemia5. metagenomic analyses of patients infected with covid-19 have frequently reported high reads of cariogenic and periodontopathic bacteria such as porphyromonas gingivalis, fusobacterium nucleatum, prevotella intermedia6, endorsing the notion of a connection between the oral microbiome and covid-19 complications. evidence suggests that periodontopathic bacteria are involved in the pathogenesis of respiratory diseases and are associated with chronic inflammatory systemic diseases including type-2 diabetes, hypertension and cardiovascular disease. these diseases are frequently reported comorbidities associated with an increased risk of severe complications and death from covid-197. therefore, the current study aims to establish a link between the presence of oral bacteria porphyromonas gingivalis and sarscov-2 infection. some studies have suggested that patient sex my help to predict the patient cooperation during the treatment as females appears to be more adaptable to the treatment than males. nevertheless, the satisfaction level with the appearance is lower in females than males, thus this feature could negatively affect the use of special appliances needed during the treatment 1. additionally, the socio-economic status may have an effect on patient’s cooperation. it has been suggested that patients with high socio-economic level cooperate better than patients with low socio-economic level 2. the aim of the study was to evaluate the compliance of patients with class iii malocclusion to orthodontic treatment using different types of orthopaedic appliances. materials and methods subjects: fifty patients with covid-19 were enrolled in this study, (23 males and 27 females), their age ranges between 20-76 years. all cases were collected from hospitalized patients at ibn al-khateeb and al-ataa hospital in baghdad governorate. control group included 35 healthy volunteers, where age and sex matched to those in the study group, they tested negative rt-pcr for covid-19, and didn’t have medical history or clinic evidence of any chronic or acute diseases. inclusion and exclusion criteria: inclusion criteria included; patients with signs and symptoms of covid-19 infection (fever, generalized malaise, cough and shortness of breath) and positive rt-pcr for covid-19. exclusion criteria included; pediatric and pregnant patients, patients with chronic viral infection and systemic diseases, allergic rhinitis and chronic sinusitis and patients who could not give informed consent. oral hygiene index: was determined by the simplified oral hygiene index "oral hygiene index = debris index + calculus index"8. sample size calculation: to calculate sample size, porphyromonas gingivalis was used as primary outcome of the study, which was used to calculate sample size using online tool epitools (https://epitools.ausvet.com.au/casecontrolss) at 95% confidence interval, 5% error margin j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 54 samples collection: after obtaining ethical approval from college of dentistry, university of baghdad committee ( id no. 203), two ml of venous blood was drawn from each subject under aseptic technique. blood added in edta tube (1.5mg/ml), then kept at -70 ºc until use for the genetic bacterial detection. three ml of unstimulated saliva was collected from forty subjects in a sterile container. then it was transferred to eppendorf tubes and separated by an eppendorf centrifuge at 3000 rpm for 10 min, then the supernatant was discarded and the pellet was kept at -70 ºc until use for the genetic bacterial detection. quantification of p. gingivalis rtpcr idna extraction (blood and saliva samples) genomic dna was isolated from blood or saliva samples according to the protocol reliaprep™ blood gdna miniprep system, promega. iireaction setup and thermal cycling protocol optimization for specific detection and quantification of p. gingivalis bacteria, primers were designed for the species-specific region on the 16s rrna. the primers used for detection of p. gingivalis 16s rrna gene were designed by software program and approved by primer quest from integrated dna technology, table 1. table 1: primers of p. gingivalis. these primers were supplied by the macrogen company in a lyophilized form. lyophilized primers were dissolved in a nuclease free water to give a final concentration of 100pmol/μl as a stock solution. a working solution of these primers was prepared by adding 10μl of primer stock solution (stored at freezer -20 c) to 90μl of nuclease free water to obtain a working primer solution of 10pmol/μl. rt-pcr amplifications were performed by magnetic induction cycler real time pcr (mic rt-qpcr), with 10μl volumes containing 5 μl gotaq green master mix (2x); 0.5 μl for each primer (10 μm); 0 μl nuclease free water; and 4µl of template dna. rt-qpcr system cycling was performed with the following temperature program: denatured at 95°c for 5 minutes followed by 40 cycles of denaturation at 95°c for 20 seconds; annealing at 55°c for 20 seconds; and extension at 72°c for 30 seconds, table 2. seq. annealing temp. (°c) prouct size (bp) p. gingivalis 16srrna-f 5`-agaataagcatcggctaactcc-3` 55 99 p.gingivalis 16srrna-r 5`-gaacaacctacgcacccttta-3` j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 55 table 2: real time pcr program steps °c m: s cycles initial denaturation 95 10:00 1 denaturation 95 00:20 40 annealing 55 00:20 extension 72 00:30 absolute quantification by the standard curve the standard curve method employs a dilution series of known template copy numbers in the qpcr assay (figure 1). linear regression of log concentration (copy µl-1) versus ct gives the standard curve, and this is then used to calculate the template concentration (copy µl-1) of the sample. eight of 0.2 ml tubes were prepared, 90 µl of nuclease free water was added to each tube then 10 µl from a sample of 129*109 copy µl-1 was added to the first tube and a serial dilution was made by transferring 10 µl from the first tube to the second tube and so on. the standard curve reaction started from the tube of 129*107 copy µl-1 to the tube of 129 copy µl-1. figure 1: amplification plot of serial dilutions of genomic dna from p. gingivalis were used as templates for real-time pcr. statistical analysis: data description, analysis and presentation have been performed using a computerized software statistical package for social science (spss version 21). the shapiro wilk test was used to test the normality distribution of the quantitative variable. both descriptive and inferential statistics were used, analysis of variance student t-test, mann-whitney test and chi-square test. the statistical significance of the difference of mean between 2 groups was calculated by t-test, mann-whitney test and chi-square test. correlation among different parameters was calculated by the spearman and pearson correlation coefficient test. p<0.05 was considered significant. j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 56 results the demographic characteristics of the patients group and controls group included in this study are presented in table 3. the mean age of patients was (51.04 ± 13.25) years and (47.08 ± 11.45) years for the controls’ group. the most age group frequency was (40+ years) which comprised 80% of the patients, whereas the age group (<40 years), constituted 20% of the patients. moreover, this study showed that 54% of covid-19 patients were females, while 46% were males. there were no significant differences (p>0.05) in age and gender between the two study groups. table 3: case-control differences in gender and age. gender and age study groups p-value patients group n=50 controls group n=35 n % n % 0.774ns gender female 27 54 20 57 male 23 46 15 43 age group (years) 0.103ns <40 10 20 9 25.7 40+ 40 80 26 74.3 range (20 76) (24 72) mean ± sd 51.04±13.25 47.08±11.45 ns: non–significant, sd: standard deviation, no.: number, %: percentage. based on the severity of covid-19, the current study showed that 11 (22%) of patients have mild disease, 29 (58%) have a moderate disease and 10 (20%) have severe disease, as illustrated in figure 1. it is presented that out of 50 patients participating in this study 18 (36%) had good oral health status and 32 (64%) of patients had poor oral health status, table 4. the results showed that there were significant differences (p<0.05) in the state of oral health among three groups of patients. 7 (70%) in severe cases, 18 (62%) in moderate and 7 (64%) of mild cases had poor oral hygiene. whereas 3 (30%) of severe cases, 11 (38%) for moderate and 4 (36%) of mild cases had good oral health status, table 5. j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 57 figure 1: frequency distribution of patients according to disease severity. table 4: frequency distribution of patients according to oral hygiene. oral health status number percentage good 18 36% poor 32 64% table 5: distribution of oral hygiene according to severity of covid19. oral hygiene severity of covid19 severe moderate mild p-value good n 3 11 4 0.000 (hs) % 30% 38% 36% poor n 7 18 7 % 70% 62% 64% the current results revealed a highly significant difference (p˂0.05) in the copy number of salivary p. gingivalis between patients and controls. table 6 shows that the median number of bacteria in the patient group was higher (11954) than the median number of bacteria in the healthy control group (211). regarding the bacterial dna present in the blood of patients and controls, the findings of this study conclude that there are only five cases with bacteria in the blood and all of them were severe and that there was no significant difference in the median number of bacteria in patients and controls, as shown in table 7. j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 58 table 6: descriptive and analytical statistics of median level of p. gingivalis in saliva of patients and controls. bacterial dna patients group n=30 controls group n=10 mann-whitney p-value minimum 45 17 2.888 0.003** maximum 9576841 7774 median 11954 211 table-7: descriptive and analytical statistics of median level of p. gingivalis in blood of patients and controls. p. gingivalis patients group n=30 controls group n=10 mann-whitney p-value minimum 0 0 0.633 0.528ns maximum 128 151 median 0 0 the findings of this study state that there is no significant difference (p> 0.05) in the salivary median number of bacteria in the patients group according to severity of disease among three groups of patients. however, the median number of bacteria in severe cases was higher (20278) than that in moderate (18330) and mild (3384) cases table 8. furthermore, the median number level of p. gingivalis in poor oral hygiene was (25086), compared to that in patients with good oral hygiene (3546), as shown in table 9. table 8: salivary levels of p. gingivalis in patients according to disease severity. p. gingivalis patients group severe n=5 moderate n=18 mild n=7 p-value min 1209 848 45 0.737ns max 2799807 974105 9576841 median 20278 18330 3384 mean rank 7 6.14 12.89 severe group vs. moderate group 0.631ns severe group vs. mild group 0.417ns moderate group vs. mild group 0.787ns j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 59 table 9: salivary levels of p. gingivalis in patients according to oral hygiene. p. gingivalis good n=15 poor n=15 min 45 848 max 2799807 9576841 median 3546 25086 mean rank 13.20 17.80 p-value 0.158 ns discussion the co-infection of the sars-cov-2 with other microorganisms is a very important factor in covid19 pathogenesis that may complicate the accurate diagnosis, treatment, and prognosis of covid-19 and even increase the mortality rates9. previous studies report that p. gingivalis can facilitate the reactivation of latent epstein-barr and human immunodeficiency virus-110, 11. so a synergistic relationship between sars-cov-2 and periodontal bacteria cannot be excluded. in the present study, rt-pcr method was successfully used to detect and count p. gingivalis in saliva and blood samples. the results demonstrated that p. gingivalis was detected in both covid-19 patients and healthy subjects with a significantly higher detection rate in the saliva of patients. co-infection may be caused by decreased lymphocytes and host immune function as it is well known that sars-cov-2 infection can damage lymphocytes, especially b cells, t cells and nk cells, which will lead to the immune system’s impairment during illness12,13. these findings are consistent with a recent study14, which found that many periodontopathogenic bacterial genera (porphyromonas, prevotella and aggregatibacter) were significantly elevated in covid-19 patients as compared to control subjects. likewise, chakraborty (2020) reported that metagenomic analyzes of patients infected with sars-cov-2 have frequently reported high reads of cariogenic and periodontopathic bacteria in line with the concept of a connection between the oral microbiome and covid-19 complications6. in addition, a previous study conducted by herrera et al, (2020), elucidates that there is an association between oral diseases like periodontitis and a higher risk of increased gravity of covid-19 patients15. the co-presence of sars-cov-2 with periodontal bacteria may exacerbate periodontal tissue damage, however, the nature, extent and consequences of this interaction are currently unknown. in periodontitis patients, it can be speculated that i) a viral-bacterial synergy might facilitate penetration of sars-cov-2 through the pocket epithelium, ii) such an interaction can help viruses evade the immune response, thus enabling its entrance to gingival capillaries and endovascular transmission directly to the pulmonary vessels16, which coincides with the current finding of the presence of p. gingivalis in the blood of covid-19 patients. on the other hand, autopsy studies show a surprising lack of bacterial super-infection in those who have died from covid-1917. moreover, another study of critical care patients found no evidence of bacterial co-infection in blood, sputum or bronchoscopy sampling upon admission to intensive care18. j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 60 this study furthermore showed that the number of bacteria in severe cases were higher than that in moderate and mild with no significant differences, and that there was a significant increase in the number of bacteria among patients with poor oral hygiene compared to patients with good oral hygiene. this may attribute to the limited number of patients investigated in this study, and also the low number of patients after subdivision may result in the absence of such an association. unfortunately, no previous studies with such comparisons were found. anyhow, chakraborty et al. (2020) showed that improper oral hygiene increases the risk of inter-bacterial exchange between mouth and lungs, thus increasing the incidence of respiratory infections and post-viral bacterial complication6. this study concluded that the high level of salivary porphyromonas gingivalis in patients increases in number with disease severity, which may indicate that bacterial infections contribute to the spread of the disease. conflict of interest: none. references 1. lu r, zhao x, li j, niu p, yang b, wu h, et al. genomic characterisation and epidemiology of 2019 novel coronavirus: implications for virus origins and receptor binding. lancet 2020, 395:565–574. 2. wu cp, adhi f, highland k. recognition and management of respiratory coinfection and secondary bacterial pneumonia in patients with covid-19. cleve clin j med 2020; 2;87(11):659-663. 3. lai cc, wang cy, hsueh pr. co-infections among patients with covid-19: the need for combination therapy with non-antisars-cov-2 agents?. j microbiol immunol infect 2020. j microbiol immunol infect 2020;53(4):505-512. 4. li zt, chen zm, chen ld, zhan yq, li sq, cheng j, et al. coinfection with sars-cov-2 and other respiratory pathogens in patients with covid-19 in guangzhou, china. j med virol. 2020;92(11):2381-2383. 5. kilian, m., chapple, i., and hannig, m., et al.. the oral microbiome – an update for oral healthcare professionals. br dent j 2016; 221: 657–66. 6. chakraborty s. metagenome of sars-cov2 patients in shenzhen with travel to wuhan shows a wide range of species-lautropia, cutibacterium, haemophilus being most abundant-and campylobacter explaining diarrhea.online 24 march 2020. cited by patel j. et al. the role of oral bacteria in covid-19. lancet microbe 2020;1(3):e105. 7. patel, j. and sampson, v. the role of oral bacteria in covid-19. the lancet microbe 2020; 1(3):105. 8. greene jg, vermillion jr. the simplified oral hygiene index. the journal of the american dental association 1964;68(1):7-13. 9. hoque mn., rahman ms., ahmed r, hossain ms., islam ms., crandall ka. diversity and genomic determinants of the microbiomes associated with covid-19 and non-covid respiratory diseases. gene rep 2021;23:101200. 10. imai k, ochiai k, okamoto t. reactivation of latent hiv-1 infection by the periodontopathic bacterium porphyromonas gingivalis involves histone modification. j immunol 2009;182(6):3688-95. 11. imai, k., inoue, h., tamura, m., cueno, me., inoue, h., takeichi, o, et al. the periodontal pathogen porphyromonas gingivalis induces the epstein–barr virus lytic switch transactivator zebra by histone modification. biochimie 2012.;94(3):839-846. 12. luo y, xie y, zhang w, lin q, tang g, wu s, et al. combination of lymphocyte number and function in evaluating host immunity. aging (albany ny) 2019;11(24):12685–12707. 13. wang m, luo l, bu h, xia h. case report: one case of coronavirus desease 2019 (covid-19) in patient co-nfected by hiv with a low cd4+ t cell count. int j infect dis. 2020;96:148–150. j. bagh. coll. dent. vol. 34, no. 2. 2022 kareem et al 61 14. soffritti, i, d'accolti, m, fabbri, c, passaro, a, manfredini, r, zuliani, g, et al. oral microbiome dysbiosis is associated with symptoms severity and local immune/inflammatory response in covid-19 patients: a cross-sectional study. frontiers in microbiology 2021; 12:1397. 15. herrera, d, serrano, j, roldán, s, sanz, m. is the oral cavity relevant in sars-cov-2 pandemic? clin. oral investig. 2020; 24: 2925–2930. 16. lloyd-jones g, molayem s, pontes cc, chapple i. the covid-19 pathway: a proposed oral-vascular-pulmonary route of sarscov-2 infection and the importance of oral healthcare measures. j oral med dent res. 2021;2(1):s1. 17. fox se, akmatbekov a, harbert jl, li g, brown jq, vander heide, rs. pulmonary and cardiac pathology in african american patients with covid-19: an autopsy series from new orleans. the lancet respiratory medicine 2020;8(7):681-686. 18. bhatraju pk, ghassemieh bj, nichols m, kim r, jerome kr, et al. covid-19 in critically ill patients in the seattle regioncase series. n engl j med 2020;382(21):2012-22. 2019-الكشف الجزيئي عن البورفيروموناس اللثوية في مرضى فايروس كورونا هيفاء حمود كريم, د. بتول حسن الغرابي, د. سناريا البدريالباحثون: المستخلص المتالزمة التنفسية الحادة الوخيمة في حدوث جائحة عالمية تستمر في التأثير سلبًا على صحة اإلنسان. المجاالت ٢-ية: تسببت عدوى فايروس كورونا الخلف .تشارك ٢-فايروس كورونا الميكروبية بما في ذلك البكتيريا تفاعلت في التسبب الجزيئي المعقد جنبًا إلى جنب مع متالزمة الجهاز التنفسي الحادة الوخيمة ، وترتبط باألمراض الجهازية االلتهابية المزمنة. تم أجراء هذه الدراسة لبحث وتحديد نسبة البورفيروموناس ٢٠١٩بكتريا اللثة في مرض فايروس كورونا نظافة الفم. شارك خمسون مريًضا مصابًا واالصحاء ، وكذلك لتحري ارتباط الحمل البكتيري مع شدة المرض و ٢٠١٩اللثوية في مرضى فايروس كورونا ( عاًما, و خمسة ٧٦-٢٠تفاعل البلمرة المتسلسل ، تتراوح أعمارهم بين ) -المؤكد عن طريق تقنية أنزيم النسخ العكسي ٢٠١٩بمرض فايروس كورونا سة. تم تحديد حالة نظافة الفم من خالل مؤشر نظافة وثالثون متطوًعا ممن يتمتعون بصحة جيدة تمت مطابقة أعمارهم وجنسهم مع المرضى في هذه درا الدم واللعاب الفم المبسط. تم الحصول على عينات الدم واللعاب من المشاركين ، وتقدير البورفيروموناس اللثوية من الحمض النووي المستخرج من عينات كانت طريق تفاعل البلمرة المتسلسل في الوقت الحقيقي. تم إجراؤها عن )التي معنويا ( في p = 0.003كمية البورفيروموناس اللثوية في اللعاب أعلى البكتريا في المرضى مقارنة بمجموعة االصحاء، بينما لم يكن هناك فرق معنوي في عدد البكتيريا في عينة الدم بين المجموعتين.عالوة على ذلك كان عدد ( أظهرت هذه الدراسة أن مستوى البكتيريا اللعابية p> 0.05مع عدم وجود فروقات احصائية ) الحاالت الشديدة اعلى منه في الحاالت المتوسطة والخفيفة لدى المرضى يزداد في العدد مع شدة المرض ، مما قد يشير إلى أن االلتهابات البكتيرية تساهم في انتشار المرض. sara f.doc j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry145 beta angle in a sample of iraqi adults with class i skeletal and dental relations and its correlation with other craniofacial measurements mohammed nahidh, b.d.s., m.sc. (1) sara m. j. al-mashhadany, b.d.s., m.sc. (2) abstract background: this study aimed to determine the value of beta angle for a sample of iraqi adults with class i skeletal and dental relations and to verify the existence of sexual dimorphism and to find out the relation between this angle and other craniofacial measurements. materials and methods: sixty dental students (23 males and 37 females) with an age ranged between 20-31 years old and having class i skeletal and dental relations were chosen for this study. each student was subjected to clinical examination and digital true lateral cephalometric radiograph. the radiographs were analyzed using autocad 2007 computer program to measure the angular and linear variables. descriptive statistics were obtained for the measurements for both genders and total sample; independent samples t-test was performed to evaluate the gender difference and pearson's correlation coefficient test used to detect the relation between the beta angle and other measurements. results and conclusions: the value of beta angle in this study was 32.63°± 2.57°. when the beta angle is less than 27°, the case is class ii and when it is more than 38°, the case is class iii. there is no genders difference regarding the beta angle and this angle correlated significantly and positively with the mandibular length and articular angle and negatively with anb and saddle angles. key words: sagittal jaw relation, beta angle. (j bagh coll dentistry 2013; 25(4):145-150). introduction freeman (1) stated that, even before edward h. angle introduced his classification of malocclusion to the profession in the early 1900's, the anteroposterior relation of mandible to maxilla was a most important diagnostic criterion. this relationship can be determined from clinical observation to some degree, but it can be much more accurately evaluated from a lateral radiograph. broadbent's (2) introduction of his cephalometer in 1931 made such films available, although they were used primarily for research and growth studies until the late 1940's. from 1947 till 2009, many methods (3-39) had been developed to assess the anteroposterior (sagittal) jaw relationship. for every method, there are many advantages and disadvantages, but still the anb angle (7) is the most popular one. in 2004, baik and ververidou (37) established a new cephalometric measurement, named the beta angle, to assess the sagittal jaw relationship with accuracy and reproducibility. in this angle, three skeletal landmarkspoint a, point b, and the apparent axis of the condylewere used to measure an angle that indicated the severity and the type of skeletal dysplasia in the sagittal dimension. they found that subjects with a beta angle between 27° and 35° had a class i skeletal pattern, a beta angle less than 27° indicated a class ii skeletal pattern, a beta angle greater than 35° indicated a class iii skeletal pattern and there (1) lecturer. department of orthodontics, college of dentistry, university of baghdad. (2) assistant lecturer. department of orthodontics, college of dentistry, university of baghdad was no statistically significant difference between mean beta angle values of males and females. kamalamma (40) carried out a lateral cephalometric study in the natural head position on indian adults to determine the norms for beta angle and wits appraisal and also to correlate beta angle with the wits appraisal and anb angle. the results indicated that there was no significant difference in the norms for males and females. beta angle showed a negative linear correlation with anb angle and wits appraisal. this study aimed to determine the value of beta angle for a sample of iraqi adults with class i skeletal and dental relations and to verify the existence of sexual dimorphism and to find out the relation between this angle and other craniofacial measurements. materials and methods sample out of 80 clinically examined under and postgraduate students in the college of dentistry, university of baghdad with an age ranged between 20-31 years, 60 students (23 males and 37 females) were selected having normal occlusion, full permanent dentition regardless the third molars, and anb angle equals to 2°±2° and mp-sn angle equals to 32°±5° (7). methods each individual was examined clinically and subjected to the digital true lateral cephalometric radiograph using the planmeca promax x-ray unit. the individual was positioned within the j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry146 cephalostat with the sagittal plane of the head vertical, the frankfort plane horizontal, and the teeth were in centric occlusion. every lateral cephalometric radiograph was analyzed by autocad program 2007 to calculate the angular and linear measurements. once the picture was imported to the autocad program, it will appear in the master sheet on which the points and planes were determined, and then the measurements were obtained. the angles were measured directly as they were not affected by magnification while the linear measurements were divided by scale (the ruler in the nasal rod) for each picture to overcome the magnification. cephalometric landmarks, lines, and measurements cephalometric landmarks 1. point s (sella): the midpoint of the hypophysial fossa (41). 2. point n (nasion): the most anterior point on the nasofrontal suture in the median plane (41). 3. point a (subspinale): the deepest midline point on the premaxilla between the anterior nasal spine and prosthion (6). 4. point b (supramentale): the deepest midline point on the mandible between infradentale and pogonion (6). 5. point me (menton): the lowest point on the symphyseal shadow of the mandible seen on a lateral cephalogram (42). 6. point go (gonion): a point on the curvature of the angle of the mandible located by bisecting the angle formed by the lines tangent to the posterior ramus and inferior border of the mandible (42). 7. point c: the center of the condyle (37). 8. point ans (anterior nasal spine): it is the tip of the bony anterior nasal spine in the median plane (41). 9. point pns (posterior nasal spine): this is a constructed radiological point, the intersection of a continuation of the anterior wall of the pterygopalatine fossa and the floor of the nose. it marks the dorsal limit of the maxilla (41). 10. point ar (articulare): the point of intersection of the external dorsal contour of the mandibular condyle and the temporal bone (4). cephalometric lines 1. sella-nasion (sn) line: it is the anteroposterior extent of anterior cranial base (41). 2. mandibular plane (mp): formed by a line joining gonion and menton (42). 3. na line: formed by a line joining nasion and point a (6). 4. nb line: formed by a line joining nasion and point b (6). 5. c-b line: a line connecting the center of the condyle c with b point (37). 6. a-b line: a line connecting a and b points (6). 7. a line from point a perpendicular to the c-b line (37). 8. sellaarticulare (s-ar) line: a line from sella to articulare (41). 9. palatal plane (pp): a line joining between anterior nasal spine and posterior nasal spine (41). 10. articularegonion (argo) line: a line joining between articulare and gonion (41). cephalometric measurements 1. anb angle: the angle between lines n-a and n-b. it represents the difference between sna and snb angles or it may be measured directly as the angle anb (7). 2. beta angle: it is the angle between the line from point a perpendicular to the c-b line and the a-b line (37). 3. sn planemandibular plane angle (sn-mp): the angle between the s-n plane and the mandibular plane (41). 4. gonial angle (ar-go-me): the angle between the posterior border of the ramus and the mandibular plane (41). 5. saddle angle (n-s-ar): the angle between the anterior and the posterior cranial base. this angle formed at the point of intersection of the s-n plane and the s-ar plane (41). 6. articular angle (s-ar-go): this angle formed at the point of intersection of the s-ar plane and the ar-go plane (41). 7. basal plane angle (pp-mp): this defines the angle of inclination of the mandible to the maxillary base (41) 8. s-n: a distance from sella to nasion (41). 9. s-ar: a distance from sella to articulare (41). 10. maxillary length: it represents the distance from anterior nasal spine to posterior nasal spine (43). 11. mandibular length: it represents the distance from gonion to menton (43). 12. ramus length: the distance between ar and go (41). 13. total anterior facial height (afh): it’s measured from n to me (41). 14. upper anterior facial height (ufh): it’s measured from n to ans (42). 15. lower anterior facial height (lfh): it’s measured from ans to me (42). 16. posterior facial height (pfh): it’s measured from s to go (41). j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry147 statistical analyses all the data of the sample were subjected to computerized statistical analysis using spss version 15 (2006) computer program. the statistical analysis included: 1. descriptive statistics: means, standard deviations, standard errors, minimum, maximum and statistical tables. 2. inferential statistics: independent-samples ttest for the comparison between both genders and pearson's correlation coefficient test to detect the relation between the beta angle and other measurements. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 * significant 0.01 ≥ p > 0.001 ** highly significant p ≤ 0.001 *** very highly significant results and discussion in this study, the normal value of the beta angle had been determined for a sample of iraqi adults with class i dental and skeletal relations with its relation to different craniofacial measurements. in iraq, two studies had been done using this angle as a measurement that determine the features of class ii and iii (44,45) depending on the value of baik and ververidou (37). the variables will be discussed under two headings: 1descriptive statistics and gender difference a. angular measurements the results showed that all of the angular measurements except mp-sn angle and saddle angle were larger in males than females with a non-significant difference. saddle angle was larger significantly in females than males; this comes in agreement with yassir (46) and this was considered normal as the saddle angle increased with the decreased of anb angle (47). the mean value of sn-mp was smaller significantly in males than females indicating that the males had a tendency towards forward rotation. the value of beta angle was slightly higher than baik and ververidou (37) and kamalamma (40) due to the age factor in the first as they conducted their study on subjects had age between 9 and 15 years old and the head position during taking the radiograph in the second. there was 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36(9): 676-700. j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry149 table 1: descriptive statistics and genders difference males =23, females =37, total sample =60, d.f. = 58 variables genders descriptive statistics genders difference mean s.d. s.e. min. max. t-test p-value anb° males 2.61 1.47 0.31 0 4 0.70 0.48 (ns) females 2.35 1.32 0.22 0 4 total 2.45 1.37 0.18 0 4 n-s-ar° males 122.04 4.30 0.90 112 134 -2.90 0.01 ** females 126.14 5.84 0.96 114 137 total 124.57 5.63 0.73 112 137 s-ar-go° males 143.13 5.45 1.14 133 156 0.40 0.69 (ns) females 142.49 6.52 1.07 126 156 total 142.73 6.09 0.79 126 156 gonial angle° males 125.22 5.61 1.17 116 140 0.89 0.38 (ns) females 124.11 4.04 0.66 117 138 total 124.53 4.69 0.61 116 140 sn-mp° males 30.65 2.74 0.57 27 37 -2.62 0.01 ** females 32.62 2.89 0.48 27 37 total 31.87 2.97 0.38 27 37 pp-mp° males 23.35 3.45 0.72 17 30 0.14 0.89 (ns) females 23.22 3.50 0.57 15 29 total 23.27 3.45 0.45 15 30 beta° males 33.17 2.71 0.56 27 38 1.29 0.20 (ns) females 32.30 2.46 0.40 28 38 total 32.63 2.57 0.33 27 38 s-n (mm) males 70.45 2.52 0.52 65.7 77.05 6.27 0.000 *** females 66.83 1.94 0.32 62.3 70.2 total 68.22 2.79 0.36 62.3 77.05 s-ar (mm) males 36.35 2.52 0.53 31.2 42.02 5.74 0.000 *** females 32.16 2.88 0.47 23.9 38.84 total 33.77 3.41 0.44 23.9 42.02 ar-go (mm) males 50.74 4.73 0.99 38.71 57.22 5.63 0.000 *** females 44.69 3.57 0.59 38.8 54.09 total 47.01 4.99 0.64 38.71 57.22 ans-pns (mm) males 57.01 4.06 0.85 50.74 68.86 6.02 0.000 *** females 52.28 2.01 0.33 45.4 55.2 total 54.09 3.74 0.48 45.4 68.86 go-me (mm) males 74.03 3.68 0.77 65.6 80.02 4.68 0.000 *** females 69.28 3.90 0.64 57.2 77.9 total 71.10 4.45 0.57 57.2 80.02 uafh (mm) males 53.19 2.80 0.58 45.31 59.02 3.69 0.000 *** females 50.62 2.52 0.41 44.9 55.5 total 51.60 2.89 0.37 44.9 59.02 lafh (mm) males 69.61 4.07 0.85 60.11 78.18 7.53 0.000 *** females 62.05 3.59 0.59 54.1 69.03 total 64.95 5.27 0.68 54.1 78.18 tafh (mm) males 121.10 4.58 0.95 114.48 132.02 8.93 0.000 *** females 111.11 3.97 0.65 101.4 118.7 total 114.94 6.44 0.83 101.4 132.02 pfh (mm) males 82.74 4.94 1.03 74.9 92 8.75 0.000 *** females 72.79 3.83 0.63 64.5 80.8 total 76.61 6.47 0.84 64.5 92 j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry150 table 2: relation between beta angle and other variables variables relation beta° total anb° r -0.44 p-value 0.000 *** n-s-ar° r -0.34 p-value 0.01 ** s-ar-go° r 0.30 p-value 0.02 * gonial angle° r -0.04 p-value 0.77 (ns) sn-mp° r -0.05 p-value 0.71 (ns) pp-mp° r 0.01 p-value 0.93 (ns) s-n (mm) r -0.06 p-value 0.63 (ns) s-ar (mm) r -0.15 p-value 0.26 (ns) ar-go (mm) r 0.20 p-value 0.13 (ns) ans-pns (mm) r 0.06 p-value 0.63 (ns) go-me (mm) r 0.26 p-value 0.04 * uafh (mm) r 0.02 p-value 0.91 (ns) lafh (mm) r 0.14 p-value 0.29 (ns) tafh (mm) r 0.14 p-value 0.28 (ns) pfh (mm) r 0.14 p-value 0.30 (ns) table 3. the values of beta angle in different studies. author(s) baik and ververidou (37) kamalamma (40) present study year 2004 2009 2013 age (yr) 9-15 18-25 20-31 sex male female total male female total male female total mean 30.9 31.1 31.1 32.33 31.41 31.8 33.17 32.30 32.63 s.d. 2 3.73 3.46 3.57 2.71 2.46 2.57 min. 27 28 27 28 27 max. 35 35 38 38 38 11athra'a f.docx j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 69 the effect of thymosin beta 4 on developing dental tissue (experimental study on rats) noor natiq, b.d.s. (1) athra'a y. al-hijazi, b.d.s., m.sc. ph.d. (2) abstract background: odontogenisis is a complex process controlled by dynamic and reciprocal interactions that regulated by various molecules. thymosin β4 is a small bioactive peptide with wide spectrum biological effects on much cell types. the present study was designed to highlight the effect of synthetic exogenous tβ4 on developing dental tissue of the upper central teeth of rats, by histological examination and immunohistochemical evaluation of tgfβ1. materials and method: thirty six albino wister pregnant rat 18control group received intraperitoneal injection of normal saline and the others are experimental group received 50µg/300µl of tβ4 injection. the animals were sacrificed at periods 16th and 18th day i.u.l and one day post natal, as six animals for each period. histological and immunohistochemical evaluation for expression of tgf β1 in dental tissue of upper central teeth of the rat were done results: in-vivo results showed that experimental group had accelerated stages of tooth development with acceleration in deposition of dental hard tissue (enamel and dentin) with high positive expression of tgf β1by enamel organ, dental papilla and dental sac cells. conclusion: these data suggest synthetic exogenous tβ4 act as bioactive initiator enhances tooth development by stimulating proliferation and differentiation of both epithelial and mesenchymalcells. keywords: tooth development, thymosintβ4 and tgf β. (j bagh coll dentistry 2016; 28(3):69-74). introduction tooth development is a complex physiological process includes different stages bud, cap and bell stage (1), it is characterized by a series of reiterative molecular interactions occur between odontogenic epithelium and ectomesenchymal which in neural crest in origin. signaling molecules of several conserved families mediated the communications between cells also they mediate the communications within the same tissue layer most of these molecules belong to tgfβ superfamily and other families (2). tgf β1 is amember of tgfβ superfamily of cytokines,it plays an important role in regulating crucial biological processes such as cell proliferation, differentiation, apoptosis, and extracellular matrix deposition and remodeling so it acts as a positive and negative regulator of cellular growth(3). thymosin beta4 is a small bioactive peptide consist of 43 amino acids residue and has multiple biological functions during embryonic development as it has prominent role in sequestration of g-actin monomers and actin cytoskeletal organization that necessary for cell motility and survival (4,5). tβ4 is highly associated with tooth morphogenesis as it related with differentiation of dental epithelium through up-regulation of number of biological effectors such as laminin5, vascular endothelial growth factor and tgfβ (6 8). (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. other important biological properties of tβ4 including recruitment and differentiation of stem cells, angiogenesis (9), and antiapoptic activity (10). materials and methods thirty six albino wister pregnant female rats aged (2-3months) and weighting (0.25-0.3 kg). all animals kept under controlled conditions of temperature, drinking and food consumption and all experimental procedures were carried out according to ethical principles of animal experimentation. the study groups include: 1. control group (18 pregnant rats which received normal saline as i.p injections for ten days starting at time zero of gestation). 2. experimental group (18 pregnant rats received t β4 as i.p injections for the same period as control group. materials 1. thymosin beta 4 synthetic peptide from abcam company uk (ab42265). 2. immunohistochemical polyclonal antibody transforming growth factor beta1 (tgfβ1) from abcam company uk (ab66043). methods histological evaluation after scarifying the animals at periods 16th and 18th day i.u.l and one day post natal. the specimens include upper jaw with two central incisors are fixed in 10% buffered formalin for 73 hours then the samples dehydrated and embedded in paraffin. 5µm section was stained j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 70 with heamatoxylin and eosin (h&e). other sections for immunohistochemical identification of tgf β1for all periods and in all studied groups. determination of immunohistochemical results for tgfβ1 for each specimen, the number of positive expression of tgf β1 was determined by evaluating 100 cells for eachslide in five high power fields (hpf) counting the positive one, then the mean of count for eight slides for each sample(11). statistical analysis a. descriptive data analysis. b. inferential data analysis. results histological results at 16th day i.u.l the experimental group show cap stage of tooth development with proliferating packed cells occupying the hole enamel organ while control group show bud stage(fig 1, 2) at 18th day i.u.l experimental group shows enamel organ at bell stage with multiple tooth germs in some samples(fig 1, 2) one day post natal shows advanced bell stage with accelerated deposition of dental enamel and dentin with primitive bone (fig 1, 2) immunohistochemical results of tgfβ1 for all studied periods: positivity for expression of tgfβ1illustrated by dental epithelial and mesenchymal cells (fig 3, 4) experimental group including all three periods records a strong positive expression for tgfβ1.(fig 4). statistical analysis revealed that the experimental group including all studied periods illustrated highly significant value in comparisons to control group (table 1). table 1: statistic analysis of different type of positive cells expressed tgf b1 in the studied groups distributed in each period with comparisons significant periods cells groups no. m sd se 95% c.i. for mean min. max. anova f-test l.b. u.b. 16 d ay s enamel organ control 6 9 0.52 0.21 8.8 9.9 9 10 f=31.937 p=0.000 hs exp. 6 11 0.98 0.40 9.8 11.9 10 12 dental papilla control 6 7 1.21 0.49 6.1 8.6 6 9 exp. 6 12 0.84 0.34 10.6 12.4 10 12 dental sac control 6 11 2.73 1.12 8.5 14.2 8 16 exp. 6 17 1.17 0.48 15.9 18.4 15 18 18 d ay s enamel organ control 6 12 0.84 0.34 10.6 12.4 10 12 f=31.409 p=0.000 hs exp. 6 11 0.98 0.40 9.8 11.9 10 12 dental papilla control 6 15 2.43 0.99 12.0 17.1 11 18 exp. 6 18 1.33 0.54 16.8 19.6 16 20 dental sac control 6 10 0.75 0.31 9.0 10.6 9 11 exp. 6 17 2.07 0.84 15.2 19.5 14 20 1 da y ol d enamel organ control 6 15 0.75 0.31 14.4 16.0 14 16 f=44.329 p=0.000 hs exp. 6 17 0.75 0.31 16.4 18.0 16 18 dental papilla control 6 14 1.87 0.76 11.5 15.5 11 16 exp. 6 20 1.37 0.56 18.2 21.1 18 22 dental sac control 6 18 1.33 0.54 16.4 19.2 16 20 exp. 6 23 1.21 0.49 22.1 24.6 22 25 j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 71 (a) (b) (c) figure 1: control group (h&e stain). (a) view of upper jaw of rat 16thday i.u.l,tooth germ at bud stage, oral ectoderm(pink arrow),basement membrane(green arrow),enamel organ(eo),dental papilla(dp),dental sac(ds) (x20). (b) at 18th day iul, tooth germ shows outer enamel epithelium.(arrow),inner enamel epithelium.(arrow heads),dental papilla(dp), stellate reticulum(sr),dental lamina(dl) (x20).(c) one day postnatal, tooth germ at bell stage (x10). (a) (b) (c) (d) figure 2:experimentalgroup (h&e stain). (a) upper jaw of rat at 16th day iul shows. inner enamel epithelium (green arrow head),outer enamel epithelium(green arrow), proliferating packed cells(red arrow) (x10). (b) at 18th day i.u.l tooth germ at bell stage (arrow) (x4). (c) multiple tooth germs (x40). (d) one day post natal, tooth germ shows, dentine (d),predentine(pd) pulp(p), enamel(e), odontoblast(od) (x40). j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 72 (a) (b) (c) figure 3: control group with immunohistochemical expression of tgf beta1 (a) at 16th day i.u.l upper jaw shows positivity by basal cell of tooth germ (arrow), mesenchymal cell (arrow heads) (x20). (b) at 18th day iul shows positivity by .inner enamel epithelial (arrows), outer enamel epithelial (arrow head) in cervical loop (x20).(c) one day old, shows positivity by odontoblast (od),ameloblast(am) (x40). (a) (b) (c) figure 4: experimental group with immunohistochemical expression of tgfβ1 (a). at 16th day iul shows positivity by.inner enamel epithelial (arrow), outer enamel epithelial (arrow head) (x20).(b) at 18th day iul shows positivity by inner enamel epithelial (ieep), outer enamel epithelial (oeep), stellate reticulum (sr),stratum intermedium (red arrow heads), mesenchymal cell(green arrows) in dental sac(ds) (x100). (c) one day old, shows positivity by ameloblast (arrows) (x100). j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 73 discussion the present study shows enhancement of tooth germ development, in embryo of 16thday i.u.l of experimental group, tooth germ presents cap stage with proliferating packed cells occupying the whole enamel organ. dental papilla and dental sac show proliferation of mesenchymal cells control group shows tooth germ at bud stage with difference in the histological feature in comparisons to experimental group. 1. the employed synthetic exogenous thymosin beta (4) composed of sequence of amino acids from 1to 11 of total 43 of tβ4 molecule, this part has an important role in the organization of cytoskeleton by binding to and sequesters actin monomer (g-actin) so it inhibits actin polymerization. as actin is an abundant protein present in all cells and it is important in maintaining cell structure and regulating cell motility (5). 2. laminin-5 is extracellular glycoprotein mediates attachment, migration and organization of cells to tissues during embryonic development, tβ4 increases the production of laminin5 resulted in promotion of cell migration and cell to cell and cell _ matrix (12). 3. thymsin β4 may induce stem cell differentiation (13). developed tooth germ of experimental group at18thday i.u.l shows bell stage, with a records of multiple tooth germs in two different stages in some specimens .the primitive pulp identifies formation of numerous new blood vessels .at one day post natal embryo a successful apposition of hard dental tissues (dentin and enamel) was detected in experimental group, and can be attributed to the followings: 1. thymosin beta 4 may promote stem cell migration and differentiation of mesenchymal tissue into odontoblast, osteoblast (14). 2. thymosin beta 4 has multiple biological activities includes, upregulation endothelial cell differention and stimulate angiogenesis by differentiation and directional migration of endothelial cells (15). 3.thymosin β4 regulates the expression of runtrelated transcription factor2 runx2 mrna that plays important role in production of ameloblastin, amelogenin, dentin matrix protein and dentin sialophosphoprotein all of these are important component of enamel and dentin matrices respectively (16, 17). runx2 plays impotant role in development and calcification of tooth germ (18) and it regulates odontogenesis related genes (8). for tgfb1 expression 1. thymosin β4 increased expression of many genes associated with angiogenesis, cell proliferation, and migration such as: vascular endothelial growth factor vegf b, vegf c, vegf d, vegf receptor1, matrix metalloproteinases2(mmp2) and tgf beta1(19). 2. in secreting ameloblast, it was found that signaling from ameloblast increase autocrine effect of local tgf β1 on development of enamel organ and provide the basis for synthesis of enamel proteins (20),and in the present study ,it seems that treated with tβ4enhanced proliferation of ameloblast and then increased expression of tgf β1. in conclusions: ¸ thymosin beta4 of 50 µl dose injected to pregnant rat at zero time of gestation found to be initiator for the developing tooth germ as the present results showed advanced stages of tooth development in comparisons with control group and as follow: ¸ advanced stage for tooth germ in each studied periods. ¸ records of multiple tooth germs. ¸ acceleration apposition of dental hard tissues enamel and dentin especially (enamel). ¸ identification of packed cells in enamel organ. ¸ numerous newly blood vessels were seen in mesenchymal tissue for dental papillae and dental sac. ¸ high expression of tgfb1 by epithelial and mesenchymal stem cells and by specialized cells includeameloblast and odontoblast and osteoblast. references 1. huang xf, chai y. tgf-β signaling and tooth development. chin j dent res 2010;13: 7–13. 2. jernvall j, thesleff i. tooth shape formation and tooth renewal: evolving with the same signals. development 2012;139(19):3487-97. 3. massague j. tgf-βsignaling in context. nat rev mol cell boil 2012;13:616-630. 4. goldstein al, hannappel e, kleinman hk.thymosin beta 4: actin_sequestrating protein moonlights to repair injured tissues. trends mol med 2005;11: 4219. 5. sonse g, qin p, goldstien al, wheater m. biological activities of thymosin beta 4 defined by active sites in short peptide sequence. faseb j 2010; 24: 2144-51. 6. safer d, elzinga m, nachmias vt. thymosin beta 4 and fx an actin sequestering peptide, are indistinguishable.jbiolchem 1991; 266:4029-32. 7. ookuma y, kiyoshima t, kobayashi i. multifunctional involvement of thymosin beta 4 in tooth germ development. histochem cell biol2013;139: 355-70. 8. kiyoshima t, fujiwara h, nagato k, etal. induction dental epithelial cell differentiationmarker gene j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 74 expression in non human keratinocyte by transfection with thymosin beta 4. stem cell res 2014; 12: 309-22. 9. grant ds, rose w, yaen c,etal.thymosin beta 4 enhances endothelial cell differentiation and angiogenesis. angiogenisis 1999; 3: 125-35. 10. choi sy, kim dk, eun b, etal. antiapoptic function of thymosin beta in developing chick spinal motoneurons.biochembiophys res commun 2006; 346: 872-8. 11. piatelli a, rubini c, fioroni m, tripodid, strocchi r. transforming growth factorbeta 1 expression in normal healthy pulps and in those with irreversible pulpitis intendod j 2004; 37:114-9. 12. sonse g, xu l, parch l etal. thymosin beta 4 stimulates laminin-5 production independent of tgfbeta exp. cell res2004; 293:165-83. 13. smart n, risebro ca, melville aa, moses k, schwartz rj, chien kr, riley pr. thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization. nature 2007; 445:177-82. 14. lee s-i, kim ds,etal. the role of thymosin beta 4 on odontogenic differentiation in human dental pulp cells. plos one2013;8(4):e61960. 15. malinda km, goldstein al,kleinman hk. thymosin beta 4 stimulates directional migration of human umbilical vein endothelial cells. faseb j 1997;11: 474-81. 16. chen s, rani s, etal. differential regulation of dentin sialophosphoprotein expression by runx2 during odontoblastcytodifferentiation. j biolchem2005; 280: 29717-27. 17. xie m, koyoshima t, yamazah,etal. functional implication of nucleolin in the mouse first molar development. j biolchem 2007;282: 23275-83. 18. chen s, heinrich j, wang yh, etal. runx2, osx, and dspp in tooth development. j dent res 2009;88: 904-9. 19. matsuo k, kasaki y, adachi k, etal. promoting effect of thymosin β4on granulation tissue and new bone formation after tooth extraction in rats oral surg oral med oral pathol oral radiol endo 2012;114: 17-26. 20. nagano y, oidas s, suzaki s, etal. pocrine enamel protein fractions contain transfporming growth factor beta 1. j periodontal 2006;77: 1688-94. j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 69 the effect of thymosin beta 4 on developing dental tissue (experimental study on rats) noor natiq, b.d.s. (1) athra'a y. al-hijazi, b.d.s., m.sc. ph.d. (2) abstract background: odontogenisis is a complex process controlled by dynamic and reciprocal interactions that regulated by various molecules. thymosin β4 is a small bioactive peptide with wide spectrum biological effects on much cell types. the present study was designed to highlight the effect of synthetic exogenous tβ4 on developing dental tissue of the upper central teeth of rats, by histological examination and immunohistochemical evaluation of tgfβ1. materials and method: thirty six albino wister pregnant rat 18control group received intraperitoneal injection of normal saline and the others are experimental group received 50µg/300µl of tβ4 injection. the animals were sacrificed at periods 16th and 18th day i.u.l and one day post natal, as six animals for each period. histological and immunohistochemical evaluation for expression of tgf β1 in dental tissue of upper central teeth of the rat were done results: in-vivo results showed that experimental group had accelerated stages of tooth development with acceleration in deposition of dental hard tissue (enamel and dentin) with high positive expression of tgf β1by enamel organ, dental papilla and dental sac cells. conclusion: these data suggest synthetic exogenous tβ4 act as bioactive initiator enhances tooth development by stimulating proliferation and differentiation of both epithelial and mesenchymal cells. keywords: tooth development, thymosintβ4 and tgf β. (j bagh coll dentistry 2016; 28(3):69-74). introduction tooth development is a complex physiological process includes different stages bud, cap and bell stage (1), it is characterized by a series of reiterative molecular interactions occur between odontogenic epithelium and ectomesenchymal which in neural crest in origin. signaling molecules of several conserved families mediated the communications between cells also they mediate the communications within the same tissue layer most of these molecules belong to tgfβ superfamily and other families (2). tgf β1 is amember of tgfβ superfamily of cytokines,it plays an important role in regulating crucial biological processes such as cell proliferation, differentiation, apoptosis, and extracellular matrix deposition and remodeling so it acts as a positive and negative regulator of cellular growth(3). thymosin beta4 is a small bioactive peptide consist of 43 amino acids residue and has multiple biological functions during embryonic development as it has prominent role in sequestration of g-actin monomers and actin cytoskeletal organization that necessary for cell motility and survival (4,5). tβ4 is highly associated with tooth morphogenesis as it related with differentiation of dental epithelium through up-regulation of number of biological effectors such as laminin5, vascular endothelial growth factor and tgfβ (6 8). (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. other important biological properties of tβ4 including recruitment and differentiation of stem cells, angiogenesis (9), and antiapoptic activity (10). materials and methods thirty six albino wister pregnant female rats aged (2-3months) and weighting (0.25-0.3 kg). all animals kept under controlled conditions of temperature, drinking and food consumption and all experimental procedures were carried out according to ethical principles of animal experimentation. the study groups include: 1. control group (18 pregnant rats which received normal saline as i.p injections for ten days starting at time zero of gestation). 2. experimental group (18 pregnant rats received t β4 as i.p injections for the same period as control group. materials 1. thymosin beta 4 synthetic peptide from abcam company uk (ab42265). 2. immunohistochemical polyclonal antibody transforming growth factor beta1 (tgfβ1) from abcam company uk (ab66043). methods histological evaluation after scarifying the animals at periods 16th and 18th day i.u.l and one day post natal. the specimens include upper jaw with two central incisors are fixed in 10% buffered formalin for 73 hours then the samples dehydrated and embedded in paraffin. 5µm section was stained j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 70 with heamatoxylin and eosin (h&e). other sections for immunohistochemical identification of tgf β1for all periods and in all studied groups. determination of immunohistochemical results for tgfβ1 for each specimen, the number of positive expression of tgf β1 was determined by evaluating 100 cells for eachslide in five high power fields (hpf) counting the positive one, then the mean of count for eight slides for each sample(11). statistical analysis a. descriptive data analysis. b. inferential data analysis. results histological results at 16th day i.u.l the experimental group show cap stage of tooth development with proliferating packed cells occupying the hole enamel organ while control group show bud stage(fig 1, 2) at 18th day i.u.l experimental group shows enamel organ at bell stage with multiple tooth germs in some samples(fig 1, 2) one day post natal shows advanced bell stage with accelerated deposition of dental enamel and dentin with primitive bone (fig 1, 2) immunohistochemical results of tgfβ1 for all studied periods: positivity for expression of tgfβ1illustrated by dental epithelial and mesenchymal cells (fig 3, 4) experimental group including all three periods records a strong positive expression for tgfβ1.(fig 4). statistical analysis revealed that the experimental group including all studied periods illustrated highly significant value in comparisons to control group (table 1). table 1: statistic analysis of different type of positive cells expressed tgf b1 in the studied groups distributed in each period with comparisons significant periods cells groups no. m sd se 95% c.i. for mean min. max. anova f-test l.b. u.b. 16 d ay s enamel organ control 6 9 0.52 0.21 8.8 9.9 9 10 f=31.937 p=0.000 hs exp. 6 11 0.98 0.40 9.8 11.9 10 12 dental papilla control 6 7 1.21 0.49 6.1 8.6 6 9 exp. 6 12 0.84 0.34 10.6 12.4 10 12 dental sac control 6 11 2.73 1.12 8.5 14.2 8 16 exp. 6 17 1.17 0.48 15.9 18.4 15 18 18 d ay s enamel organ control 6 12 0.84 0.34 10.6 12.4 10 12 f=31.409 p=0.000 hs exp. 6 11 0.98 0.40 9.8 11.9 10 12 dental papilla control 6 15 2.43 0.99 12.0 17.1 11 18 exp. 6 18 1.33 0.54 16.8 19.6 16 20 dental sac control 6 10 0.75 0.31 9.0 10.6 9 11 exp. 6 17 2.07 0.84 15.2 19.5 14 20 1 da y ol d enamel organ control 6 15 0.75 0.31 14.4 16.0 14 16 f=44.329 p=0.000 hs exp. 6 17 0.75 0.31 16.4 18.0 16 18 dental papilla control 6 14 1.87 0.76 11.5 15.5 11 16 exp. 6 20 1.37 0.56 18.2 21.1 18 22 dental sac control 6 18 1.33 0.54 16.4 19.2 16 20 exp. 6 23 1.21 0.49 22.1 24.6 22 25 j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 71 (a) (b) (c) figure 1: control group (h&e stain). (a) view of upper jaw of rat 16thday i.u.l,tooth germ at bud stage, oral ectoderm(pink arrow),basement membrane(green arrow),enamel organ(eo),dental papilla(dp),dental sac(ds) (x20). (b) at 18th day iul, tooth germ shows outer enamel epithelium.(arrow),inner enamel epithelium.(arrow heads),dental papilla(dp), stellate reticulum(sr),dental lamina(dl) (x20).(c) one day postnatal, tooth germ at bell stage (x10). (a) (b) (c) (d) figure 2:experimentalgroup (h&e stain). (a) upper jaw of rat at 16th day iul shows. inner enamel epithelium (green arrow head),outer enamel epithelium(green arrow), proliferating packed cells(red arrow) (x10). (b) at 18th day i.u.l tooth germ at bell stage (arrow) (x4). (c) multiple tooth germs (x40). (d) one day post natal, tooth germ shows, dentine (d),predentine(pd) pulp(p), enamel(e), odontoblast(od) (x40). j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 72 (a) (b) (c) figure 3: control group with immunohistochemical expression of tgf beta1 (a) at 16th day i.u.l upper jaw shows positivity by basal cell of tooth germ (arrow), mesenchymal cell (arrow heads) (x20). (b) at 18th day iul shows positivity by .inner enamel epithelial (arrows), outer enamel epithelial (arrow head) in cervical loop (x20).(c) one day old, shows positivity by odontoblast (od),ameloblast(am) (x40). (a) (b) (c) figure 4: experimental group with immunohistochemical expression of tgfβ1 (a). at 16th day iul shows positivity by.inner enamel epithelial (arrow), outer enamel epithelial (arrow head) (x20).(b) at 18th day iul shows positivity by inner enamel epithelial (ieep), outer enamel epithelial (oeep), stellate reticulum (sr),stratum intermedium (red arrow heads), mesenchymal cell(green arrows) in dental sac(ds) (x100). (c) one day old, shows positivity by ameloblast (arrows) (x100). j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 73 discussion the present study shows enhancement of tooth germ development, in embryo of 16thday i.u.l of experimental group, tooth germ presents cap stage with proliferating packed cells occupying the whole enamel organ. dental papilla and dental sac show proliferation of mesenchymal cells control group shows tooth germ at bud stage with difference in the histological feature in comparisons to experimental group. 1. the employed synthetic exogenous thymosin beta (4) composed of sequence of amino acids from 1to 11 of total 43 of tβ4 molecule, this part has an important role in the organization of cytoskeleton by binding to and sequesters actin monomer (g-actin) so it inhibits actin polymerization. as actin is an abundant protein present in all cells and it is important in maintaining cell structure and regulating cell motility (5). 2. laminin-5 is extracellular glycoprotein mediates attachment, migration and organization of cells to tissues during embryonic development, tβ4 increases the production of laminin5 resulted in promotion of cell migration and cell to cell and cell _ matrix (12). 3. thymsin β4 may induce stem cell differentiation (13). developed tooth germ of experimental group at18thday i.u.l shows bell stage, with a records of multiple tooth germs in two different stages in some specimens .the primitive pulp identifies formation of numerous new blood vessels .at one day post natal embryo a successful apposition of hard dental tissues (dentin and enamel) was detected in experimental group, and can be attributed to the followings: 1. thymosin beta 4 may promote stem cell migration and differentiation of mesenchymal tissue into odontoblast, osteoblast (14). 2. thymosin beta 4 has multiple biological activities includes, upregulation endothelial cell differention and stimulate angiogenesis by differentiation and directional migration of endothelial cells (15). 3.thymosin β4 regulates the expression of runtrelated transcription factor2 runx2 mrna that plays important role in production of ameloblastin, amelogenin, dentin matrix protein and dentin sialophosphoprotein all of these are important component of enamel and dentin matrices respectively (16, 17). runx2 plays impotant role in development and calcification of tooth germ (18) and it regulates odontogenesis related genes (8). for tgfb1 expression 1. thymosin β4 increased expression of many genes associated with angiogenesis, cell proliferation, and migration such as: vascular endothelial growth factor vegf b, vegf c, vegf d, vegf receptor1, matrix metalloproteinases2(mmp2) and tgf beta1(19). 2. in secreting ameloblast, it was found that signaling from ameloblast increase autocrine effect of local tgf β1 on development of enamel organ and provide the basis for synthesis of enamel proteins (20),and in the present study ,it seems that treated with tβ4enhanced proliferation of ameloblast and then increased expression of tgf β1. in conclusions: ¸ thymosin beta4 of 50 µl dose injected to pregnant rat at zero time of gestation found to be initiator for the developing tooth germ as the present results showed advanced stages of tooth development in comparisons with control group and as follow: ¸ advanced stage for tooth germ in each studied periods. ¸ records of multiple tooth germs. ¸ acceleration apposition of dental hard tissues enamel and dentin especially (enamel). ¸ identification of packed cells in enamel organ. ¸ numerous newly blood vessels were seen in mesenchymal tissue for dental papillae and dental sac. ¸ high expression of tgfb1 by epithelial and mesenchymal stem cells and by specialized cells includeameloblast and odontoblast and osteoblast. references 1. huang xf, chai y. tgf-β signaling and tooth development. chin j dent res 2010;13: 7–13. 2. jernvall j, thesleff i. tooth shape formation and tooth renewal: evolving with the same signals. development 2012;139(19):3487-97. 3. massague j. tgf-βsignaling in context. nat rev mol cell boil 2012;13:616-630. 4. goldstein al, hannappel e, kleinman hk.thymosin beta 4: actin_sequestrating protein moonlights to repair injured tissues. trends mol med 2005;11: 4219. 5. sonse g, qin p, goldstien al, wheater m. biological activities of thymosin beta 4 defined by active sites in short peptide sequence. faseb j 2010; 24: 2144-51. 6. safer d, elzinga m, nachmias vt. thymosin beta 4 and fx an actin sequestering peptide, are indistinguishable.jbiolchem 1991; 266:4029-32. 7. ookuma y, kiyoshima t, kobayashi i. multifunctional involvement of thymosin beta 4 in tooth germ development. histochem cell biol2013;139: 355-70. 8. kiyoshima t, fujiwara h, nagato k, etal. induction dental epithelial cell differentiationmarker gene j bagh college dentistry vol. 28(3), september 2016 the effect of thymosin oral diagnosis 74 expression in non human keratinocyte by transfection with thymosin beta 4. stem cell res 2014; 12: 309-22. 9. grant ds, rose w, yaen c,etal.thymosin beta 4 enhances endothelial cell differentiation and angiogenesis. angiogenisis 1999; 3: 125-35. 10. choi sy, kim dk, eun b, etal. antiapoptic function of thymosin beta in developing chick spinal motoneurons.biochembiophys res commun 2006; 346: 872-8. 11. piatelli a, rubini c, fioroni m, tripodid, strocchi r. transforming growth factorbeta 1 expression in normal healthy pulps and in those with irreversible pulpitis intendod j 2004; 37:114-9. 12. sonse g, xu l, parch l etal. thymosin beta 4 stimulates laminin-5 production independent of tgfbeta exp. cell res2004; 293:165-83. 13. smart n, risebro ca, melville aa, moses k, schwartz rj, chien kr, riley pr. thymosin beta4 induces adult epicardial progenitor mobilization and neovascularization. nature 2007; 445:177-82. 14. lee s-i, kim ds,etal. the role of thymosin beta 4 on odontogenic differentiation in human dental pulp cells. plos one2013;8(4):e61960. 15. malinda km, goldstein al,kleinman hk. thymosin beta 4 stimulates directional migration of human umbilical vein endothelial cells. faseb j 1997;11: 474-81. 16. chen s, rani s, etal. differential regulation of dentin sialophosphoprotein expression by runx2 during odontoblastcytodifferentiation. j biolchem2005; 280: 29717-27. 17. xie m, koyoshima t, yamazah,etal. functional implication of nucleolin in the mouse first molar development. j biolchem 2007;282: 23275-83. 18. chen s, heinrich j, wang yh, etal. runx2, osx, and dspp in tooth development. j dent res 2009;88: 904-9. 19. matsuo k, kasaki y, adachi k, etal. promoting effect of thymosin β4on granulation tissue and new bone formation after tooth extraction in rats oral surg oral med oral pathol oral radiol endo 2012;114: 17-26. 20. nagano y, oidas s, suzaki s, etal. pocrine enamel protein fractions contain transfporming growth factor beta 1. j periodontal 2006;77: 1688-94. dropbox 8 saif 41-46.pdf simplify your life 21. ra'ed f.doc j bagh college dentistry vol. 25(1), march 2013 factors associated oral and maxillofacial surgery and periodontics 122 factors associated with facial swelling severity following impacted lower third molar surgery: a prospective study ra'ed mohammed ayoub al-delayme, b.d.s, s.omfs.s, c.a.b.omfs, m.f.d. r.c.s., m.o.m.s., r.c.p.s (1) waleed kh. ismael, b.d.s, f.i.c.m., omfs (2) mona abdulhadee alsafi, b.d.s. m.sc. (3) abstract background: the ultimate purpose of this prospective study is to estimate and measure swelling associated with surgical extraction of impacted mandibular third molars in different four post-operative times and to identify the risk factors associated with determination of their risk degree. material and methods: in this prospective cohort study 159 consecutive cases in which removal of impacted lower third molars in 107outpatients were evaluated. five groups of variables have been studied which are regarded as a potential factor for swelling after mandibular third removal which will enable the surgeon to predict and counsel high risk patients in order to offer a preventive strategy. results: facial measurements were carried out on 1st, 2nd days, 1st and 2nd week postoperatively to measure the swelling area in each time respectively the peak level of swelling was noted on the second post-operative day and subside by seven days but in some cases the swelling was still in minor degree while in most patients it was zero by day 14. conclusions: the degree of difficulty of the surgical extraction was the main indicators of risk factors for the swelling in all post-operative days because it involves all the other risk factors together. key words: surgical extraction impacted mandibular third molar, swelling. (j bagh coll dentistry 2013; 25(1):122-128). introduction the mandibular third molars are the most frequently impacted teeth in man which makes their extraction one of the most frequent surgical procedures carried out in the world with the common approach of treatment is the surgical removal which may be considered as one of the routine aspects of oral and maxillofacial surgery performed on young adults and adolescents (1) .as such, numerous studies have been devoted to evaluate all their aspects, and major group of these studies deal with the post-operative complications by rate and type(1,2) .as expected with any surgical operation, there are a number of intraand post-operative complications which has significant post-surgical sequelae that may have both a biological and social impact3 some authors (3-5) confirmed that the postoperative swelling as expected sequelae is usually associated with the surgical removal of lower third molars. (1)senior lecturer at oral and maxillofacial surgery dept., dentistry dept., al-yarmuk university college. senior specialist at oral and maxillofacial surgery dept., al-yarmuk teaching hospital, baghdad, iraq (2)senior specialist, head of oral and maxillofacial surgery dept., al-yarmuk teaching hospital. (3)assistant prof., dean of faculty of dentistry, al-yarmuk university college. this swelling is direct and immediate postoperative tissue reactions as a consequences of the surgical procedure or can be a normal part of the healing process swelling are the most common postoperative complaints that influence the patients’ quality of life in the days following surgery (6) therefore, numerous studies in literature (6-9) illustrated several factors that influence the occurrence of swelling including age; gender; medications; smoking; previous infection;poor oral hygiene;difficulty of extraction; length of extraction; surgical time ; technique and surgeon experience in this prospective study, the postoperative swelling associated with surgical extraction of impacted mandibular third molars will be measured and evaluated in different times and the predictive risk factors with estimation of their risk degree will be determined which will enable the surgeon to predict and counsel high risk patients in order to offers a preventive strategy. matrials and methods data sampling and criteria the present prospective cohort study which is investigated 159 consecutive cases of removal of impacted lower third molars in 107 outpatients with the mean age of (25.54 ± 3.75) years and range of (16-31) years was performed by two members of the dental department of alyarmouk university college between october 1, 2009 and december 31, 2010. the ethics committee of university had approved the study protocol. the j bagh college dentistry vol. 25(1), march 2013 factors associated oral and maxillofacial surgery and periodontics 123 inclusion criteria included healthy individuals with no systemic diseases; patients are not given preoperative antimicrobial drugs or other medications that might influence healing, only one impacted tooth extracted each visit and for all procedures and local anesthesia alone is used. the exclusion criteria included the lingual splits technique and female patients who are pregnant or lactating study variables the variables of the study are sets of variables suspected to be related to complications. these sets of predictor variables are divided into five groups as shown in (table 1): 1patient variables included sex, age and the side (right/left).age is classified into three groups(19-22 ), (23-26 ) and (27-31) years 2indication for removal included pain, prophylactic, resorption of adjacent distal root of second molar, orthodontic purpose, associated pathological lesion and atypical facial pain. 3preoperative conditions variables included smoking, oral contraceptive and pericoronitis. 4radiographical variables in which the pell and gregory (10) and winter (11) radiographical classifications are used to document the position of the impacted mandibular third molars. the numbers of roots are assessed then these classifications are used to predict the surgical difficulty and classified into: simple, moderate and difficult. 5operative-specific variables included type of flap (envelop or triangular), lingual flap retraction, bone removal, tooth sectioning, visibility of inferior alveolar nerve after extraction, intraoperative bleeding, the surgeon (both right-handed operators ) and the operation time, which is with the mean of 27.41±12.44 minutes and range of 8-53 minutes and is classified into three groups (<21 ) ,( 21-40 )and(>40) minutes. surgical technique all surgical procedures were performed in the same clinic with similar equipment by one of two surgeons. both surgeons had the same experience and worked with the same principles; the surgical field and all the surgical materials are sterile, the 5th year dental student were used as a surgical assistant in all the cases. one lower third molar extracted in each operation with the protocol that include local anesthesia, all teeth were removed from a buccal approach using either triangular or envelop flap. when it necessary to raise a lingual flap, a howarth periosteal elevator is used to protect the lingual periosteum and the lingual tissues .bone removal is done with burs in the conventional manner and, if necessary, the tooth is divided with burs before elevation. the flaps are sutured with a 4-0 silk suture. postoperative instructions and prescribed drugs are explained to the patient. for the first 5 postoperative days all patients have given antibiotics (amoxicillin 750 mg every 8 hours), drugs for patient with peptic ulcer (ranitidine 300 mg three times daily) and an anti-inflammatory drug (ibuprofen 600 mg every 8 hours for 4-5 days). and a mouth rinse (0.2% chlorhexidine digluconate) is performed every 12 hours for 15 days. postoperative assessment patients were told to contact the clinic for any postoperative problem or if certain symptoms occur, such as pain that could not be relieved by the prescribed analgesics or post-operative bleeding. all patients were reviewed on the 1st and 2nd days and 1st and 2nd week postoperatively. the suture material was removed after one week. swelling assessment and measurements a baseline measurement was carried out just before the surgery and similar measurements were carried out on 1st, 2nd days, 1st and 2nd week postoperatively. a single professional operator, repeating the procedure three times on each patient, made the measurements. the average of measurements was then taken (in cm) and recorded. two distances were considered to assess facial measurements, that is the distance from the corner of the mouth to the ear lobe and the outer canthus of the eye to the angle of the mandible measured by a thread which was then transferred to a ruler, so facial area (cm2) in each studied time for each case = (vertical measurement (cm) multiply by horizontal measurement) divided by two. the difference between the postoperative and preoperative measurements was calculated to measure the swelling area (cm2) in four different times. statistical analysis the data obtained are statistically analyzed by spss (spss for windows, version 13, spss inc., chicago, il, usa) the one-way analysis of variance (anova) tests allow to determine if one given variable has a significant effect on postoperative swelling. the level of significance is set at (p) less than .01or .05.partial eta-squared is used to measure strength of association and the effect of size of variables on postoperative j bagh college dentistry vol. 25(1), march 2013 factors associated oral and maxillofacial surgery and periodontics 124 swelling. an lsd pairwise comparisons test was applied for each of the independent variables which have a significant effect on postoperative swelling. the results were presented as the mean ± standard deviation and standard error of mean. results post-operative swelling evaluations facial measurements were carried out on 1st, 2nd days, 1st and 2nd week postoperatively to measure the swelling area in each time respectively as shown in (table 2 and figure1). post-operative swelling reaches its peak level in the first 48 hours and the swelling continues in rare cases till the end of second post-operative week. risk factors there is no statistical significant difference between patient variables; indication for removal variables and preoperative conditions except the contraceptive which has a significant effect on the postoperativeswelling on the first and second postoperative days as shown in (table 3) the most statistical significant radiographical variables and operative-specific variables on multivariate analysis on increasing the postoperative swelling are shown in (table 3). the other factors have not any statistical significant differences on the postoperative complications. eta squared values indicate that effect sizes of difficulties in the 1stpostoperative week on postoperative swelling was medium while all other estimated effect size were relatively weak as shown in (table 3). comparisons test was applied for each of the independent variables which have a significant effect on postoperative swelling as shown in (table 4) to see the most statistical significant variables between sub groups. so the most highly significant risk factors with high strengths of correlation in all the post-operative times as shown in (table 3) are: 1. angulations: distoangular impaction 2. width: ii and iii 3. depth: all levels 4. difficulty: moderate difficulty and very difficult 5. operation time: 21-40 and >40 minutes discussion surgical removal of an impacted third molar often involves a lot of complications during the postoperative period, one of which is the swelling which contribute to major cause of postoperative discomfort experienced by most of the patients after third molar removal. these symptoms are not observed immediately after surgery but rather begin gradually (12) there are many factors that contributes to these situations which described as complex, but they originate from an inflammatory process initiated by surgical trauma (12,13). set off factors have been suggested as contributing to postoperative swelling. this paper deals with this welling as objective parameters for measurement. an investigation has been made to identify factors that influence the occurrence of severity of swelling. during our observation the peak level of swelling was noted on the second post-operative day and subside by seven days but in some cases the swelling still in minor degree while in most of patients it was zero by day 14 which come in line with other studies (9, 14) the authors (3,5,15) confirm that patient factors are regarded as one of the factors affecting postoperative swelling, but in our studies we found that gender and age in addition to the tooth location variables don’t have any significant effect. regarding to indications of removal it has been suggested that the presence symptoms at the time of removal must be considered to be a risk factor for postoperative complications (16) in the present study, however, we have failed to confirm this hypothesis. in a study made by grossi et al (6) there was no correlation between postoperative swelling and the smoker patients and he also confirms that there is a statistically significant correlation between postoperative swelling and the oral contraceptives, but our surprising result was completely opposite. this study fails to confirm the hypothesis that smoker use is a risk factor for severe postoperative swelling, and it confirms that oral contraceptives have a significant effect as risk factor in first and second day postoperatively. distoangular and vertical type of impaction when compared with horizontal and mesioangular type of impactions in this study have been shown to be associated with higher degree of swelling in all post portative days (p=0,000). the distoangular always has a significant effect as risk factor but the mesioangular type has no effect in other studies (17) while the other types are the point of controversies (6). the type of impaction gives a prediction of the difficulty of extraction and hence the severity of postoperative reactions. a statistically significant difference in swelling was noted regarding the level and depth of impaction in all post portative days with high level of significant (p=0,000) in the class ii and iii position and in level b and c in addition to the visibility of inferior alveolar nerve, these results j bagh college dentistry vol. 25(1), march 2013 factors associated oral and maxillofacial surgery and periodontics 125 have statistically significant difference that go with all other studies (3, 6). significant influence over the magnitude of postoperative swelling was detected with respect to the degree of difficulty of the surgical extraction in all post-operative days specially in the first pot operative days (p=0,000, -p.e.s.0.341).this due to the amount of mucoperiosteum that has to be reflected and the amount of bone that supposed to be removed (6, 16). in point of soft tissues view, we have notice that the degree of swelling has high significant associations only in the second post-operative days with triangular buccal flap and this agrees with other studies while lingual flap retraction has high significant associations only in the first postoperative week (16, 19). there was a high significant correlation (p=0,000) between postoperative swelling and bone removal in all the postoperative periods because it produces a significant degree of trauma to the bony structures, potentially resulting in a significant inflammatory reaction (12,13). on the other hand, the tooth sectioning is also a risk factor in the swelling but only in the second day and first week postoperatively and this came in agreement with others (3-5). a lot of articles have been published on the relationship between the duration of the operation and postoperative swelling (5,13,16). it has been confirmed by the present study that the longer the operation takes, the more magnitudes of swelling significance are in all the post-operative period(p=0,000).authors believe that increasing surgical complexity is often a valuable predictor of inflammationrelated sequelae (5,16,20). the results have showed that the expertise of the surgeon does not seem to have a significant influence on the progress of swelling; some authors (20, 21) also notice that the degree of postoperative swelling seems to be influenced exclusively by the degree of difficulty and length of the surgical procedure regardless of the expertise of the surgeon. in conclusion the peak level of swelling was registered on the second post-operative day .a patient’s age, gender and indications of removal were not significantly correlated to the postoperative swelling .the tooth angulations, level and depth of impaction in addition to bone removal and tooth sectioning which will increase the duration of the operation showed a significant impact on the swelling in all the days postoperatively. the degree of difficulty of the surgical extraction was the main indicators of risk factors for the swelling in all post-operative days because it involves all the other risk factors together. our statistical analysis identified no significant differences related to the expertise of the surgeon. references 1contar cm, de oliveira p, kanegusuku k, berticellird, azevedo-alanis lr, machado ma. complications in third molar removal: a retrospective study of 588 patients. med oral patol oral cir bucal 2010; 15:74-8. 2kunkel m et al. third molar complications requiring hospitalization oral surg oral med oral pathol oral radiol endod 2006; 102:300. 3 kim jc et al. minor complications after mandibular third molar surgery: type, incidence, and possible prevention. oral surg oral med oral pathol oral radiol endod 2006; 102: 4. 4calvo am et al. analgesic and anti-inflammatory doseresponse relationship of 7.5 and 15mg meloxicam after lower third molar removal: a double .blind, randomized, cross over study j oral maxillofac surg 2007; 36: 26-31. 5sato fr et al. short-term outcome of postoperative patient recovery perception after surgical removal of third molars j oral maxillofac surg 2009; 5:1083. 6grossi gb, maiorana c, garramone ra, borgonovo a, creminelli l, santoro f. assessing postoperative discomfort after third molar surgery. a prospective study. j oral maxillofac surg 2007; 65:901. 7satilmis¸ t, garip h, arpaci e. assessment of combined local anesthesia and ketamine for pain, swelling, and trismus after surgical extraction of third molarsj oral maxillofacsurg 2009; 67:1206. 8chi h bui, edward b, seldin, thomas b. dodson, types, frequencies, and risk factors for complications after third molar extraction. j oral maxillofac surg 2003;61:1379-138. 9aras mh, güngörmüs m. placebo-controlled randomized clinical trial of the effect two different low-level laser therapies (lllt)—intraoral and extraoral—on trismus and facial swelling following surgical extraction of the lower third molarlasers med sci 2010; 25: 641. 10pell gj, gregory gt. impacted mandibular third molars: classification and modified technique for removal. dent dig 1933; 39:330–8.10. 11winter gb. principles of exodontias as applied to the impacted mandibular third molar. st louis (mo). american medical book. co; 1926. 12hasangarip, tülinsatılmıs, gühandergin ,faysalug˘urlu ,an dkamil göker .effects of midazolam/low-dose ketamine conscious intravenous sedation on pain ,swelling, and trismus after surgical extraction of third molars j oral maxillofac surg 2011;69:1023-1030. 13blondeau f, daniel ng. extraction of impacted mandibular third molars: postoperative complications and their risk factors. j canad dent assoc 2007; 73: 325–9. 14esen e, tasar f, akhan o. determination of the antiinflammatory effects of methylprednisolone on the sequelae of third molar surgery j oral maxillofac surg 1999; 57:1201– 6. 15hidemichi yuasa, masayuki sugiura. clinical postoperative findings after removal of impacted j bagh college dentistry vol. 25(1), march 2013 factors associated oral and maxillofacial surgery and periodontics 126 mandibular third molars: prediction of postoperative facial swelling and pain based on preoperative variables british journal of oral and maxillofacial surgery 2004; 42: 209-14. 16hasan g,tülin s,gühan d, faysal ug, kamil g. effects of midazolam/low-dose ketamine conscious intravenous sedation on pain, swelling, and trismus after surgical extraction of third molars. j oral maxillofac surg 2011; 69:1023-30. 17seidu a bello, wasiu l adeyemo, babatunde o bamgbose, emeka v obi and ademola a deyinka. effect of age, impaction types and operative time on inflammatory tissue reactions following lower third molar surgery. head & face medicine 2011; 7: 8 18chukwuneke f, onyejiaka n. management of postoperative morbidity after third molar surgery: a review of the literature niger j med 2007; 16:107-12. 19kirk dg, liston pn, tong dc, et al: influence of two different flap designs on incidence of pain, swelling, trismus, and alveolar osteitis in the week following third molar surgery. oral surg oral med oral pathol oral radiol endod 2007; 4: 1. 20seidu adebayo bello, abayomi a. olaitan, akinola l. ladeinde. a randomized comparison of the effect of partial and total wound closure techniques on postoperative morbidity after mandibular third molar surgery american association of oral and maxillofacial surgeons. j oral maxillofac surg 2011; 69: e24-e30. 21baqain z, abu karaky a, sawair f, khaisat a, rajab l. frequency estimates and risk factors for postoperative morbidity after third removal molar removal: a prospective cohort study. j oral maxillofac surg 2008; 66: 2276-83. table 1: study variables abbreviations: ian, inferior alveolar nerve; no., total number; %, percentage. variable no. % variable no. % patient variables gender male 73 68.2 teeth in male 103 64.8 female 34 31.8 teeth in female 56 35.2 age 19-22 years 46 28.9 teeth in right 84 52.8 23-26 years 76 47.8 teeth in left 75 47.2 27-31 years 37 23.3 age range (16-31) age mean(24.54±3.26) indication for removal preoperative conditions variables pain 53 33.3 smoking habit yes 91 57.2 prophylactic 44 27.7 no 68 42.8 resorption of adjacent distal root of 2nd molar 22 13.8 contraceptives yes 13 8.2 no 146 91.8 orthodontic purpose 17 10.7 pericoronitis yes 38 23.9 associated pathological lesion 14 8.8 no 121 76.1 atypical facial pain 9 5.7 radiographical variables angulations mesioangular 71 44.7 vertical 29 18.2 horizontal 36 22.6 distoangular 23 14.5 width i 57 35.8 iii 28 17.6 ii 74 46.5 depth a 57 35.8 c 19 11.9 b 83 52.2 number of roots multiple 87 54.7 uncompleted 15 9.4 single 57 35.8 difficulties difficult 24 15.1 simple 37 23.3 moderate 98 61.6 operative-specific variables flap type triangular 138 86.8 lingual flap retraction yes 21 13.2 envelop 21 13.2 no 138 86.8 bone removal with 124 78 tooth sectioning with 117 73.6 without 35 22 without 42 26.4 i.a.n. visibility yes 14 8.8 intra-operative bleeding yes 7 4.4 no 145 91.2 no 152 95.6 operation time <21 (minutes) 41 25.8 range (8-53minutes) mean (27.41±12.44) 21-40 (minutes) 87 54.7 >40 (minutes) 31 19.5 surgeons surgeon 1 84 52.8 surgeon 2 75 47.2 j bagh college dentistry vol. 25(1), march 2013 factors associated oral and maxillofacial surgery and periodontics 127 table 2: swelling area (cm2) in different post-operative times 1 st post-operative day 2ndpost-operative day 1st post-operative week 2nd post-operative week mean 10.06 39.41 3.33 0.83 standard deviation ±12.94 ±29.20 ±7.09 ±2.72 stander error 1.03 2.32 0.56 0.22 minimum 00 00 00 00 maximum 48.50 115.88 29.44 23.44 table 3: the relation between most statistics significant variables with the postoperative swelling variable 1st p.o. day 2nd p.o. day 1stp.o.week 2ndp.o.week sig. p.e.s sig. p.e.s. sig. p.e.s. sig. p.e.s. contraceptives 0.004 ** 0.051 w 0.030 * 0.030 w 0.077 0.252 angulations 0.000 ** 0.118 w 0.000 ** 0.163 w 0.000** 0.311 w 0.000** 0.222 w width 0.000 ** 0.297 w 0.000 ** 0.271 w 0.000** 0.418 w 0.000** 0.198 w depth 0.000 ** 0.244 w 0.000 ** 0.208 w 0.000** 0.336 w 0.000** 0.148 w difficulty 0.000 ** 0.341 m 0.000 ** 0.401 w 0.000** 0.646 w 0.000** 0.316 w flap type 0.232 0.009 ** 0.043 w 0.020* 0.034 w 0.134 lingual flap retraction 0.252 0.117 0.000** 0.090 w 0.079 bone removal 0.021 * 0.033 w 0.000 ** 0.080 w 0.001 ** 0.063 w 0.041 * 0.026 w tooth sectioning 0.158 0.044 * 0.026 w 0.030 * 0.030 w 0.065 visibility of i.a.n 0.000 ** 0.158 w 0.000 ** 0.200 w 0.000 ** 0.448 w 0.000 ** 0.295 w intraoprative bleeding 0.015 * 0.037 w 0.000 ** 0.076 w 0.001 ** 0.074 w 0.003 ** 0.055 w operation time 0.000 ** 0.218 w 0.000 ** 0.379 w 0.000 ** 0.485 w 0.000 ** 0.285 w abbreviations: p.o., postoperative; sig., significant; p.e.s., partial eta squared; w., weak; m., medium; *: significant at (p-value < 0.05), **: significant at (p-value< 0.01) j bagh college dentistry vol. 25(1), march 2013 factors associated oral and maxillofacial surgery and periodontics 128 table 4: comparisons test was applied to each of the independent variables which have a significant effect on postoperative swelling variable 1 st p.o. day 2nd p.o. day 1st p.o. week 2nd p.o. week angulations mesioangular horizontal 0.677 0.539 0.620 0.880 vertical 0.234 0.061 0.006** 0.062 distoangular 0.000** 0.000** 0.000** 0.000** horizontal vertical 0.162 0.241 0.039* 0.123 distoangular 0.000** 0.000** 0.000** 0.000** vertical distoangular 0.009** 0.002** 0.000** 0.000** width i ii 0.072 0.029* 0.094 0.577 iii 0.000** 0.000** 0.000** 0.000** ii iii 0.000** 0.000** 0.000** 0.000** depth a b 0.000** 0.000** 0.000** 0.005** c 0.000** 0.000** 0.000** 0.000** b c 0.001** 0.002** 0.000** 0.004** difficulty very difficult moderate difficulty 0.000** 0.000** 0.000** 0.000** minimum difficulty 0.000** 0.000** 0.000** 0.000** moderate difficulty minimum difficulty 0.013* 0.000** 0.000** 0.097 operation time <21 21-40 0.248 0.000** 0.053 0.453 >40 0.000** 0.000** 0.000** 0.000** 21-40 >40 0.000** 0.000** 0.000** 0.000** abbreviations: p.o., postoperative; *: significant at (p-value < 0.05); **. , significant at (p-value <0.01). figure 1: mean values of swelling area (cm 2) according to studied time 10.06 39.41 3.33 0.83 0 10 20 30 40 m ea n 1st day 2nd day 1st week 2nd week studied time mean values of swelling area (cm2) according to studied time aseel final.doc j bagh college dentistry vol. 26(3), september 2014 apexification and orthodontics, pedodontics and preventive dentistry 108 apexification and periapical healing of immature teeth using mineral trioxide aggregate zainab a.a. al-dahan, b.d.s, m.sc. (1) muna s. khalaf, b.d.s, m.sc. (2) aseel haidar al-assadi, b.d.s, m.sc. (2) abstract background: apexification is a method to induce a calcified barrier in a root with an open apex or the continued apical development of an incomplete root in teeth with necrotic pulp. mta apexification has several advantages such as it neither gets resorbed, nor weakens the root canal dentin, and also sets in the wet environment. the aim of this study is to evaluate the effectiveness of the use of mta in apexification and periapical healing of teeth with incomplete root formation and periapical infection. materials and method: apexification was carried out on fourteen permanent immature teeth of eleven children aged 7-12 years attended the teaching hospital of college of dentistry, baghdad university using mineral trioxide aggregate followed by obturation of the root canal using gutta percha. the teeth were monitored at 3, 6 and 12 months intervals by clinical examination and radiographical evaluation of root development and healing of periapical lesion. results: after a 12 months interval, all the teeth appeared to be asymptomatic so that the rate of clinical success in all of the cases was (100%). radiographically, the success rate was 100% for thirteen teeth while that tooth which was started the treatment with large periapical lesion, showed regression of the periapical destruction suggestive of bone healing and regeneration of the root apex around the mta material, end with small one so that it started unhealthy but finished with improved healing process. conclusion: mineral trioxide aggregate showed both clinical and radiographical success as a material used to induce root-end closure in permanent teeth with immature root formation. this material had the primary advantage of reduction in the number of appointments, development of proper apical seal and healing of periapical lesions. key words: apexification, immature teeth, mineral trioxide aggregate. (j bagh coll dentistry 2014; 26(3):108-112). الخالصة نموالقم ة نمو قم ة ج ذر األس نان المنخ ورة الل ب غی ر مكتمل ة اس تمرار ھو أسلوب للحث على تكوین حاجز كلسي في قمة الجذر غیر مكتمل النم و أو ھ و تحفی ز apexification: خلفیة الھدف من ھذه الدراس ة ھ و تقی یم . ، وال یضعف عاج قناة الجذر ، و یتصلب أیضا في بیئة رطبة لھ ذوبان او تاكللھ العدید من المزایا كونھ ال یحصل mta apexification. الجذریة .نموقم ة الج ذر لالس نان ف ي حال ة وج ود التھ اب مص احب للقم ة الجذری ة ف ي تك وین القم ة الجذری ة لألس نان ودوره ف ي تش كیل و apexificationف ي mtaفعالی ة اس تخدام س نة وف دوا ال ى المستش فى التعلیم ي لكلی ة ط ب األس نان، جامع ة 12-7أجریت الدراسة على أربعة عشرة سن دائمیة غیر مكتملة نمو القمة الجذریة من أحد عشر طف ال تت راوح أعم ارھم ش ھرا م ن خ الل الفح ص 12و 6و 3وقد تم رصد ومتابعة حالة األسنان عل ى فت رات gutta percah د القناة الجذریة باستخدام مادة حشوة الجذریلیھ س mtaباستخدام مادة ال ,بغداد جمی ع األس نان كان ت ب دون اي أع راض ش ھرا، ان 12كانت النتائج بعد م رور . لحالة القمة الجذریة ومالحظة شفاء القمة الجذریة من اي التھاب مصاحب لھا الشعاعيالسریري والتقییم ٪ ل ثالث عش رة س ن ف ي ح ین أن الس ن الت ي ب دأت الع الج 100وفیما یخص األشعة السینیة ، كان معدل النجاح ) ٪ 100( سریریة بحیث كان معدل النجاح السریري في جمیع الحاالت ، اي ان الس ن انتھ ى بالتھ اب ص غیر ج دا م ع أنھ ا ب دأت mtaظم ي و تجدی د ذروة الج ذر ح ول م ادة ال مع آفة ذرویة كبیرة ، أظھرت انحسارا كبیرا موحیة بشفاء مصحوب بتك ون ع . ن م ع االنتھ اء م ن المتابع ة ل وحظ التحس ن الكبی ر ف ي عملی ة الش فاء تخدم للحث على إغالق الجذر في نھایة األسنان الدائمة مع تشكیل قم ة الج ذور على حد سواء كمادة تس mta أظھرت الدراسة نجاح سریري واشعاعي في استخدام مادة ال: االستنتاج آلف ات الذروی ة كان لھ ذه الم ادة می زة رئیس یة ف ي اختص ار ع دد زی ارات الم ریض للمستش فى ، ووض ع خ تم او ح اجز قم ي س لیم و ك ذلك المس اعدة عل ى الش فاء م ن ا . غیرمكتملة النمو .كتملة النموالمصاحبة للقمة الجذریة غیر م introduction devitalization of the pulp is one of the sequelae of traumatic injuries to the young permanent teeth. it leads to concomitant arrest in the future development of the immature roots of the involved tooth. in such cases blunderbuss canals are viewed radiographically. the canals make obturation and obtaining hermetic seal of the root canal system not possible (1). therefore, different materials have been tried to create a physical barrier that enables obturation of the root canal (2). the traditional radicular-closure procedure employs calcium hydroxide (ca(oh)2). this technique was followed for the management of immature apices for over half a decade and has shown to give excellent results regardless of the periapical pathology. root development or apical calcification in addition to apical healing was obse (1)professor. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad. (2)lecturer. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad. rved within three months postoperatively and may continue for more than a year (3,4). the hydroxyl group is considered the most important component of calcium hydroxide because of the alkaline environment it provides which is required for encouraging repair and active calcification. the disadvantage of calcium hydroxide is time consuming and may require up to 7-8 months or even a year for the apical barrier to form (4). apexification using mineral trioxide aggregate (mta) provides an alternative treatment modality in immature pulpless teeth. mta did not have calcium hydroxide in its composition but it had calcium oxide that could react with tissue fluid to form calcium hydroxide (5). both mta and calcium hydroxide led to the formation of calcite crystals, these crystals which were originating from reaction of calcium ions from mta and calcium hydroxide with carbon dioxide from the tissue had a role as an initiating step in the formation of hard tissue barrier except mta requires significantly less time(6). the j bagh college dentistry vol. 26(3), september 2014 apexification and orthodontics, pedodontics and preventive dentistry 109 treatment time between the patient’s first appointment and the final restoration is lessened in addition to the regeneration achieved by this material (5-7). mta in apexification has become a popular material due to its superior biocompatibility, excellent marginal adaptability and good sealing ability. satisfactory compaction of obturating material is achievable as mta on setting provides a sound and hard apical barrier (8). the aim of this study is to evaluate the effectiveness of the use of mta in apexification and periapical healing of teeth with incomplete root formation and periapical infection. materials and methods the sample included in this study was obtained from the children attending the teaching hospital of the college of dentistry, baghdad university. the collection of the sample, treatment and follow-up started in october 2010 and ended in may 2013(each tooth was monitored for up to one year). twenty traumatized partially developed permanent maxillary incisors of seventeen (10 males and 7 females) patients were included. patients that did not return for follow up on call were excluded from the study. the number of the treated teeth with their follow up was therefore reduced to 14 teeth of eleven patients. full detailed treatment plans were explained to the children’s parents and written consents for treatment were obtained prior to the clinical procedures. an information record for each child was filled with information concerning the general health of the child including the medical history in addition to the chief complain and reason for attending the hospital. information about the history of the traumatized tooth/teeth and clinical oral findings were also recorded during an intraoral examination to determine the condition of the teeth and soft tissues. the amount of coronal fracture (according to ellis classification of tooth fracture (9)), discoloration, mobility, tenderness to percussion and pulp vitality were recorded also. vitality of the tooth was tested with ethyl chloride. a diagnostic periapical radiograph was taken to examine the presence of root fractures, the amount of root development and the condition of the periapical region. all the teeth selected for this study had coronal fracture with pulp exposure or necrotic pulp with a history of trauma ranging from ten days to two years and a previous swelling or recurrent swellings. following the administration of local anesthesia (when treating tender teeth) and after isolation of the traumatized tooth, establishment of proper unrestricted access was done to ensure complete access to the canal walls in order to acquire adequate debridement. the length of the root canal was estimated shorter than the apex 2-3 mm. after complete removal of the necrotic pulp tissue, irrigation of the canal was performed using copious amounts of 5% sodium hypochloride. the canal was then dried with premeasured absorbent paper points to the working length followed by application of root canal medicament (cmcp) and the tooth was closed with a temporary filling. irrigation of the root canal was repeated at a week interval until a completely clean and dry canal was reached. instrumentation of the canal was carried out to debride and shape the root canal walls (8). at this time mta (pro root mta, dentsply tulsa dental, u.s.a) was applied apically. mta powder was mixed with distilled water in a ratio 3:1 for about 30 seconds until it became homogenous and its consistency became thick similar to wet sand (10,11). then it was immediately carried into the root canal by the use of an endodontic messing gun (figure 1) and by hand condensation (4,11-13). figure 1: the endodontic messing gun the working length of the messing gun was adjusted 3-4 mm shorter than the estimated working length so that a 4-5mm plug was formed. the plug was checked radiographically. if creation of an ideal plug failed from the first attempt, it was rinsed with sterile water and the procedure was repeated. a sterile cotton pellet moistened with sterile water was placed over the canal and the access cavity was sealed with a temporary filling. the moistened cotton pellet allowed the mta plug to completely set. the time required for its setting is 4 hours after which the root canal could be obturated with gutta percha. in this study the pellet was left until the next day (24 hours) (14, 15). lateral compaction technique was used to obturate the canal with gutta-percha and zinc oxide eugenol sealer (2,12). periapical radiographs were taken after applying the plug and after obturating the root canal to be sure a proper seal was obtained. the patient was recalled at monthly intervals for radiographic evaluation of the apical barrier formation and periapical healing. when this was j bagh college dentistry vol. 26(3), september 2014 apexification and orthodontics, pedodontics and preventive dentistry 110 achieved the final restoration of the fractured crown was done to restore esthetic (figures 2, 3). all the patients were recalled after 3 months, 6 months and 12 months respectively and evaluated clinically and radiographically. the success or failure was determined according to the following criteria: 1. clinical evaluation: the presence of any signs such as swelling, pain, tenderness to percussion or palpation and pathological mobility was definitely indicative of clinical failure. 2. radiographical evaluation: the radiographs were examined carefully and compared with the preoperative radiographs. observation of any partial loss of the lamina dura, widening of the periodontal ligament, any sign of pathological external or internal root resorption as well as periapical or inter-radicular radiolucency was considered as radiographic failure. in case that the tooth already present with periapical radiolucency, the following calculations were made depending on periapical index (pai) (16):(1) tooth that started unhealthy (pai 3–5) and finished healthy (pai 1, 2); (2) tooth started unhealthy (pai 3–5) and finished improved but still unhealthy(healing process) (pai 3–5); (3) the tooth that started unhealthy (pai 3–5) and ended the same or worse(17). the clinical and radiographic examination of the teeth treated, throughout the study period, was carried out by the three authors. the data was described in numbers and percentage values. results the number of patients was 11 (7 males, females). the number of the teeth treated was 14. table (1) describes the sample according to age, gender, number of traumatized teeth and classification of the coronal fracture. fractures of the teeth were mostly of type iii (n= 9) followed by type iv (n= 5). table 1: distribution of sample and type of fracture classification of coronal tooth fracture* no. of teeth no. of patients age (years) v iv iii ii i female male 3 3 1 1 7 1 2 3 2 8 2 2 2 9 3 3 2 10 2 2 1 1 11 1 1 1 12 5 9 14 4 7 total * classification of tooth fracture was according to eliss. figure 2: case 1:periapical radiographs of two teeth treated with mta. a-working length estimation b-mta apexification for two incisors c-obturation of one root canal d-obturation of the other root canal e-follow-up at 3 month interval ffollow-up at 6 month interval gfollow-up at 12 month interval. a b c d e f g figure 3: case 2:periapical radiographs tooth treated with mta. adiagnostic radiograph, b-working length estimation c-mta applied at the apex d-obturation of root canal e-follow-up at 3 month interval ffollow-up at 6 month interval gfollow-up at 12 month interval. a g c d b f e j bagh college dentistry vol. 26(3), september 2014 apexification and orthodontics, pedodontics and preventive dentistry 111 the clinical findings of the treated teeth were recorded at 3, 6 and 12 months (table 2). at the three post treatment intervals there was no sign or symptom of clinical failure (clinical success was 100%). the radiographic findings of the treated teeth are shown in table (3). the periodontal ligaments were normal for all of the cases and external resorption was not found in any of them. however one case had a periapical lesion that did not heal completely even after 12 months, but it seemed to be improved progressively from the 3rd month (fig. 4), so that the findings of pai analysis revealed that this case started unhealthy and finished improved but still unhealthy (healing process). table 2: clinical findings of the treated teeth pre treatment findings clinical findings clinical success pain swelling tp* st** pm*** discoloration of tooth 2 7 2 3 0 1 no. % post treatment intervals 3months 0 0 0 0 0 0 14 100 6 months 0 0 0 0 0 0 14 100 12months 0 0 0 0 0 0 14 100 *tenderness to percussion **sinus tract ***pathological mobility table 3: radiographical findings of the treated teeth post treatment interval radiographical findings radiographical success normal pdl periapical radiolucency external resorption no. % 3 months 14 1 0 13 92.9 6 months 14 1 0 13 92.9 12 months 14 1 0 13 92.9 discussion traumatic dental injury is a common accident during childhood. the age group included in this study lied in between 7 and 12 years which is characterized by vigorous playing. although immediate treatment of a traumatized tooth raises its prognosis, most of treatments were delayed because parents can’t ascertain the seriousness of the injury or are unsure where to seek treatment. this lead to the high frequency of pulp necrosis especially evident in delayed treatment of type iii and iv fractures (1,2,14). fractures involving enamel and dentin with pulp exposure allowed the entry of bacteria into the pulp as well as chemical and thermal irritation of the pulp canal which eventually, with delay of treatment, lead to pulp necrosis (17). apexification treatment is supposed to create an environment to permit deposition of cementum, bone and periodontal ligament to continue its function of root development. the goal of this treatment was to obtain an apical barrier to prevent the passage of toxins and bacteria into periapical tissues from the root canal. technically this barrier is necessary to allow compaction of root filling material (19). mineral trioxide aggregate as an apexification material represents a primary monoblock (8). appetite like interfacial deposits formed during the maturation of mta result in filling the gap induced during material shrinkage phase and improves the frictional resistance of mta to root canal walls. the formation of nonbonding and gap filling appetite crystals also accounts for seal of mta (20). the novel approach of apexification using mta lessens the patient’s treatment time between first appointment and final restoration. during a long apexification period, the root canal is susceptible to reinfection if the coronal seal fails, and to root fracture (as seen with calcium hydroxide apexification). with the use of mta there is less chance of root fracture in immature teeth with thin roots because the material immediately bonds with the roots and strengthens it (1,21,22). radiographically the healing of the periapical radiolucencies was gained in all but one case (figure 4). although the size of the lesion decreased with time and there were no clinical symptoms of failure in this case, it was still there after a year recall. the unresolved periapical radiolucency may be due to the lesion healing with fibrous tissue, and not necessarily a sign of endodontic failure (23). periapical scar tissue originates from connective tissue-forming cells that colonize the periapical area before the cells responsible for generating the different periodontal components do so (24). as conclusion; mineral trioxide aggregate showed both clinical and radiographical success as a material used to induce root-end closure in permanent teeth with immature roots. this material had the primary advantage of reduction in the j bagh college dentistry vol. 26(3), september 2014 apexification and orthodontics, pedodontics and preventive dentistry 112 number of appointments, development of proper apical seal and healing of periapical lesions. figure 4: case 3: periapical radiographs of tooth treated with mta showing periapical radiolucency. a-diagnostic radiograph b-working length estimation c-mta applied at the apex d-obturation of root canal e-follow-up at 3 month interval ffollow-up at 6 month interval gfollow-up at 12 month interval. references 1. koyuncuoglu g, gorken fn, ikikarakayali g, zorlu s, erdem ap, sepet e, aren g. management of open apices in thirteen traumatized permanent incisors using mineral trioxide aggregate: case series. pedo dent j 2013; 23(1): 51-6. (ivsl). 2. nuvvula s, melkote th, mohapatra a, nirmala svsg. management of immature teeth with apical infections using mineral trioxide aggregate. contemporary clinical dentistry 2010; 1(1): 51-3. 3. ghose lj, baghdady vs, hikmat ym. apexification of immature apices of pulpless permanent anterior teeth with calcium hydroxide. j endod 1987; 13(6): 285-90. 4. al-dahan zaa. apexification of immature apices with calcium hydroxide. j bagh college dentistry 2002; 13: 31-41. 5. pradhan dp, chawla hs, gauba k, goyal a. comparative evaluation of endodontic management of teeth with unformed apices with mineral trioxide aggregate and calcium hydroxide. j dent child 2006; 73: 79-85. 6. holland r, souza v, nery mj, otoboni filho ja, bernabe pfe, dezan fj. reaction of rat connective tissue to implanted dentin tubes filled with mta or calcium hydroxide. j endod 1999; 25(3): 161-6. 7. chhabra n, singbal kp, kamat s. successful apexification with resolution of the periapical lesion using mineral trioxide aggregate and demineralized freeze-dried bone allograft. j conserv dent 2010; 13(2): 106-9. 8. raji vs, karunakar p, madhavi n. mineral trioxide aggregates in management of immature teeth with open apicesa report of clinical cases. j of pierre fauchard academy (india section) 2013; 27: 2-8. 9. ellis rg, davey ew. classification and treatment of injuries to the teeth of children. 5th ed. chicago: year book medical publishers; 1970. pp.1-213. 10. steinig th, regan jd, gutmann ji. the use and predictable placement of mineral trioxide aggregate in one-visit apexification cases. aust endod j 2003; 29(1): 34-42. 11. eşian d, monea a. the use of mineral trioxide aggregate versus calcium hydroxide in the treatment of necrotic immature teeth. amt 2010; 2(1): 225-58. 12. abdul-kadir st. evaluation of calcium and hydroxyl ions release from non-setting calcium hydroxide paste and mineral trioxide aggregate through three different apical aperture sizes during apexification procedure (in vitro study). a master thesis, department of pedodontics, college of dentistry, university of baghdad, 2006. 13. kumar ag, kavitha a. single visit apexification with mineral trioxide aggregate. ijda 2010; 2(1): 122-4 (ivsl). 14. gaitonde p, bishop k. apexification with mineral trioxide aggregate: an overview of the material and technique. eur j prosthodont rest dent 2007; 15(1): 415. 15. torabinejad m, hong cu, mcdonald f, et al. physical and chemical properties ofa new root-end filling material. j endod 1995; 21: 349–53. 16. conner da, caplan dj, teixeira fb. clinical outcome of teeth treated endodontically with a nonstandardized protocol and root filled with resilon. joe 2007; 33(11): 1290-2. 17. mohammed lj. evaluation of the complications due to delayed management of trauma to anterior teeth. j college dentistry 2005; 17(2): 93-6. 18. al-nazhan s, andreasen jo, al-bawardi s, al-rouq s. evaluation of the effect of delayed management of traumatized permanent teeth. j endod 1995; 21(7):391-3. 19. komabayashi t, spångberg ls. comparative analysis of the particle size and shape of commercially available mineral trioxide aggregates and portland cement. j endod 2008; 34: 94-7. 20. torabinejad m, chivian n. clinical applications of mineral trioxide aggregate. j endod 1999; 25:197-205. 21. kubasad gc, ghivari sb. apexification with apical plug of mtareport of cases. aosr 2011; 1(2):104-7. 22. el-meligy oas, avery dr. comparison of apexification with mineral trioxide aggregate and calcium hydroxide. pediatric dentistry 2006; 28(3): 248-53. 23. nair pn. on the causes of persistent apical periodontitis: a review. int endod j 2006; 39(4): 24981. 24. garcía cc, sempere fv, diago mp, bowen em. the post-endodontic periapical lesion: histologic and etiopathogenic aspects. med oral patol oral cir bucal 2007; 12 (8): 585-90. j bagh college dentistry vol. 29(1), march 2017 the effects of enamel pedodontics, orthodontics and preventive dentistry 170 the effects of enamel protective agents on shear bond strength after rebonding of stainless steel orthodontic bracket (an in vitro study) ruaa ali k. al-sarkhi, b.d.s. (1) dheaa h. al-groosh, b.d.s., m sc., ph. d. (2) abstract background: bracket rebonding is a common problem in orthodontics which may result in many drawbacks. the aims of this study were to evaluate the effects of application of two enamel protective agents “icon” and “proseal” on shear bond strength before and after rebonding of stainless steel orthodontic brackets using conventional orthodontic adhesive and to assess the site of bond failure. materials and methods: fifty sound extracted human upper first premolar teeth were selected and randomly divided into two equal groups; the first time bonding and the rebonding groups (n=30). each group was subdivided into control, icon and proseal subgroups. the enamel protective agents were applied after etching (preconditioners). shear bond strength before and after rebonding of stainless steel brackets were assessed using the universal testing machine and the adhesive remnant index was used to find out the bond failure site using a stereomicroscope. then the results were statistically analyzed using one-way anova analysis test and t-test. results: there were no significant differences in the shear bond strength mean values in either group or their corresponding subgroups. forty percentage of the bond failure in proseal groups occurred away from the enamel where 75% of those were at the enamel protective agents/adhesive interface. conclusions: the application of icon and proseal did not compromise the shear bond strength and the application of the proseal may protect the enamel surface from trauma (cracks, chipping or detachment). keywords: enamel protective agents; shear bond strength; rebonding.(j bagh coll dentistry 2017; 29(1):170-176) introduction one of the greatest problems that occasionally faces the orthodontists during and at the end of the treatment with fixed braces is the appearance of white spot lesions (wsls) and enamel demineralization which may occur due to plaque accumulation that enhanced by the fixed appliances.(1) bracket rebonding, on the other hand, is a frequently occurring problem during orthodontic treatment. (2) mechanical removal of adhesive can cause scarring and alteration of the enamel surface with the removal of the outer enamel layer which contains high minerals compared to the deeper layer. this may eventually lead to an increase in the risk of enamel demineralization. (3) different methods have been studied to prevent or reduce the occurrence of wsls during the course of orthodontic treatment such as the use of fluoridated mouth rinse, gel and fluoride containing tooth paste. (1) however, studies have shown that there was a direct association between the patient compliance to oral hygiene programme and the reduction in the development of wsls. (4) (1)m.sc student, department of orthodontic, college of dentistry, university of baghdad, iraq (2)assistant professor, department of orthodontics, college of dentistry, university of baghdad, iraq the use of preventive agents that do not depend on the patient’s cooperation has been increased to control the development of wsls. these preventive agents include topical applications of casein phosphor-peptideamorphous calcium phosphate or fluoride, (5) glass ionomer cement (6) and adhesive resin with antibacterial agents. (7) during the past decade, the use of fluoridated sealant, which acts as fluoride reservoir that releases fluoride over a long period of time, was proposed. (8) one of these sealants was proseal (reliance orthodontics). it has been shown that proseal provided maximum protection against enamel demineralization and wsls formation. additionally proseal released fluoride ions in a sustainable way over a period of 17 weeks. furthermore it can withstand the tooth brush abrasion and acid challenge. (9-11) on the other hand, the effects of lowviscosity resins infiltrant "icon" on enamel demineralization have been increasingly studied. it has been shown that icon infiltrant prevented enamel surface demineralization. (12) the icon infiltrant could be applied after bonding of orthodontic bracket; however, there are some drawbacks which include the difficulties in application procedure in dental crowding cases. additionally, in order to achieve its effective protective effect, multiple applications are necessary, which is a patient compliance dependent practice. (13) j bagh college dentistry vol. 29(1), march 2017 the effects of enamel pedodontics, orthodontics and preventive dentistry 171 therefore, applying this material before bonding may exert a better effect. it was found that the low viscosity resin infiltrant provided better sealing ability when combined with the conventional bonding agent than alone.(14) there is inconclusive information whether these agents increase or decrease the shear bond strength (sbs).therefore the use of enamel protective agents may have a great advantageous effect during bracket rebonding situations. the aims of the current study were to evaluate the effects of the application of enamel protective agents (epa) on the bond strength and the adhesive failure site after rebonding of orthodontic bracket. materials and methods fifty samples of freshly extracted sound human upper first premolars teeth were selected after being examined with 10x magnifying lens. (15) teeth were grossly intact with no restoration or caries; no cracks or any surface irregularities and marked structural or developmental anomalies such as enamel hypoplasia or decalcification. teeth were stored in a closed container at room temperature in normal saline solution (panther, uk) containing 0.1% thymol (sigma, poole, dorset, uk) to prevent dehydration and microbial growth. retentive cuts were made along the sides of the roots of each tooth to increase the retention inside the acrylic. (16) teeth were then fixed onto a glass slide (star) in a vertical position using a sticky wax at the apex of the root using a dental surveyor (dentaurum, paraline, germany) so that the force is applied at a right angle to the enamel bracket interface.(17,18) teeth were mounted in auto polymerised acrylic resin (bms dental, buonarroti, cappannoli, italy) in a vertical position with the root embedded in the acrylic block made from a specially designed molds where the crowns of the teeth protruding outside. the powder and liquid of the auto polymerised acrylic resin were then mixed, in a ratio of 2:1 according to the manufacturer’s instructions, and poured around the teeth to the level of cementoenamel junction. (8,19) after setting has been completed, the samples were stored in a patch containing normal saline solution (panther) with 0.1% thymol (sigma) which is regularly changed until bonding procedure.(20) the samples were randomly divided into two groups: the first time bonding group (g1) and the rebonding group (g2). each group was subdivided into three subgroups: the control, icon (dmg, hamburg, germany), proseal (reliance orthodontic products, itasca, il, usa) and the control group which received heliosit orthodontic adhesive (ivoclar, vivadent, schaan, liechtenstein) only without protective agents. each subgroup consists of ten samples apart from the control of g1 which contain 30 teeth. stainless steel orthodontic brackets for upper first premolars (0.022 × 0.030 inch slot standard edge wise, dentaurum, inspringen, germany) were used. the buccal surface of the enamel was cleaned with a rubber cup and non-fluoridated pumice for 10 seconds using a low speed headpiece (nsk, ec, japan). (21, 22) the enamel surface was then washed for 10 seconds and dried with oil-free steam of air for another 10 seconds. (8, 23, 24) after that, an etching gel 37% phosphoric acid (ivoclar, vivadent, schaan, liechtenstein) was applied using a disposable brush on the buccal surface of the teeth for 30 seconds according to the manufacturer’s instructions, and then washed with air/water spray and dried with oil-free steam of air until the buccal surface of the etched teeth appeared chalky white. (25) in the control subgroups, the brackets were bonded to the enamel surface of the teeth by applying a thin layer of heliosit adhesive (ivoclar) on the middle of the middle third of the buccal surface.(25) then, a constant load of 200 gm was applied on the bracket for 10 seconds. (26-29) the adhesive material was cured for 40 second (10 seconds curing time was set for each of the four directions; mesial, distal, occlusal and cervical) using vivadent light cure unit with wave length range 400-500 nm and light intensity more than 500mw/cm2. (16,30) regarding the icon subgroups, one coat layer of the low viscosity icon-dry (dmg) was applied and left to set for 180 seconds, and then light cured for 60 second. a second layer was applied, left to set for 60 seconds and then light cured for 40 seconds according to the manufacturers' instructions. 31 after that, heliosit adhesive (ivoclar) was applied similar to the control subgroup. regarding proseal subgroups, the proseal varnish (reliance orthodontic) was applied with a micro-brush on the etched tooth surface and light cured for 20 seconds. 32 after that, the adhesive was applied as described in the control subgroup. the samples were then immersed in 0.1% thymol solution and stored in an incubator (fisher scientific, usa) at 37°c for 24 hours prior to testing procedure. 8, 17, 33 shear bond strength test was done 24 hours after bonding procedure (8, 17, 33) in a universal testing machine (h50kt, tinius olsen co., england). each specimen was placed in the j bagh college dentistry vol. 29(1), march 2017 the effects of enamel pedodontics, orthodontics and preventive dentistry 172 machine base parallel to the horizontal plane. a custom made chisel-end rod was fitted inside the upper arm of the testing machine parallel to the middle third of the buccal surface of the tooth and perpendicular to the enamel bracket interface. this was done to provide a force in an occlusogingival direction. (12, 27, 34) the crosshead speed was 0.5mm/minute (35) and the highest magnitude of the load values were recorded as the load of the bond failure. the failure load (in newton) was divided by the base bonding area (13mm2 in the current study) to calculate the shear bond strength in mpa (n/mm2). the adhesive remnant index (ari) was assessed immediately using stereomicroscope (hamilton, italy) with a magnification of 20 x.(3639) the ari was scored according to artun and bergland (40) with its modified version (arim) which includes scores for enamel protective agents (epa)/ adhesive bond interface failure and enamel detachment. the scores are as followed: score 0 indicates no adhesive was left on the enamel surface of the tooth, score i indicates less than half of the adhesive was left on the tooth surface, score ii indicates more than half of the adhesive was remain on the tooth surface, score iii indicates all the adhesive was left on the tooth surface, with an impression of the bracket mesh, score iv indicates epa /adhesive bond failure, and score v indicates enamel detachment. after complete assessment, teeth from the control group (n=30) were prepared for rebonding procedure using 12-blade tungsten carbide bur (#7642, jet carbide burs, beavers dental, morrisburg, canada) at low speed (30,000 rpm) with copious water cooling system.(42) the samples were then subdivided randomly into the three subgroups as mentioned previously using similar way of epa /adhesive application. statistical analysis descriptive statistics, which includes the means, standard deviation, standard errors, minimum and maximum values of sbs were calculated for each subgroup in the g1 and g2 groups. analysis of variance (anova) was used to test the differences among the shear bond strength mean values of the subgroups in each group. t test was used to test the differences in the shear bond strength mean values between g1 and g2. chi-square was used to assess the differences between the groups and within the subgroups regarding the bonding failure site (ari). results descriptive statistics of the sbs of the control, icon and proseal subgroups in g1 and g2 groups are presented in figure 1. the results obtained from the current study showed that the mean shear bond strength values of the tested materials were higher than the optimal limits suggested by reynolds (41) which is 6-8mpa, and thus, sufficient for clinical use. for the first time bonding group (g1), the mean sbs of the control group has the highest mean value (16.3±3.9mpa) followed by that of the proseal (14.5±3.3mpa); whereas the icon has the lowest value (14.5±4.4mpa). whereas proseal subgroup in rebonding group (g2) exhibited the highest values (15.8±4.1mpa) followed by that of the control and the icon groups which showed almost similar sbs mean values (15.2±4.5mpa,14.8±3.4mpa respectively) (table 1). however, the current study showed that there was statistically non-significant (p˃0.05) difference in sbs between g1 and g2 groups (table 2) or the subgroups of each group (table 3) table 1: descriptive statistics of the shear bond strength (mpa) of the bonding and rebonding groups state groups n mean s.d. s.e. min. max. bonding group control 10 16.338 3.977 1.258 10.13 23.08 icon 10 14.507 4.483 1.418 8.08 23.33 proseal 10 14.580 3.318 1.049 8.08 18.46 rebonding group control 10 15.238 4.516 1.428 8.45 23.59 icon 10 14.847 3.480 1.100 10 21.54 proseal 10 15.807 4.156 1.314 8.72 23.33 j bagh college dentistry vol. 29(1), march 2017 the effects of enamel pedodontics, orthodontics and preventive dentistry 173 table 2: comparison of the shear bond strength in the bonding and rebonding groups. state anova sum of squares d.f. mean square f-test pvalue bonding g between groups 21.495 2 10.747 0.687 0.512 (ns) within groups 422.294 27 15.641 total 443.789 29 rebonding g between groups 4.661 2 2.330 0.140 0.870 (ns) within groups 447.977 27 16.592 total 452.638 29 table 3: comparison of the shear bond strength between the correspondence subgroups of the bonding and rebonding group. groups state descriptive statistics state difference (d.f.=18) n mean s.d. s.e. mean difference t-test p-value control bonding 10 16.338 3.977 1.258 1.100 0.578 0.570 (ns) rebonging 10 15.238 4.516 1.428 icon bonding 10 14.507 4.483 1.418 -0.340 -0.189 0.852 (ns) rebonging 10 14.847 3.480 1.100 proseal bonding 10 14.580 3.318 1.049 -1.227 -0.730 0.475 (ns) rebonding 10 15.807 4.156 1.314 figure 1: shear bond strength of the bonding and rebonding groups. the error bars represent the standard deviation. regarding the adhesive remnant index (ari), the predominant failure site of the control and icon groups were near the enamel surface (scores 0 and i) regardless of the bonding sequence. on the other hand, the proseal groups showed that 40% of the samples exhibited a failure sites away from the enamel i.e. scores ii and iv. about 75% of those were between the epa and the adhesive. however, the differences were statistically non-significant (p˃0.05) between g1 and g2 groups and their subgroups (figures 2 and 3). figure 2: bond failure site of the bonding group. 0 3 6 9 12 15 18 21 c-ve icon proseal bon… reb… j bagh college dentistry vol. 29(1), march 2017 the effects of enamel pedodontics, orthodontics and preventive dentistry 174 figure 3: bond failure sites of the rebonding group discussion during the course of orthodontic treatment with fixed braces, enamel decalcification, caries and gingivitis could occur in 2-96% of the patients depending on the complexity of the complications.(43) although some demineralized enamel resolved after the removal of the appliance i.e. fixed braces, most remained causing white spot lesions (wsls) which undermine the treatment outcomes after the treatment has completed.(44) furthermore, enamel demineralization could occur when the high mineral layer of enamel is lost during bracket rebonding.(3) different methods have been proposed to reduce enamel demineralization during orthodontic treatment. (1, 7) the use of enamel protective agents and sealants are one of those measures. to the best of our knowledge, the use of icon as a preconditioner to orthodontic adhesives during rebonding situations has not been investigated with regard to shear bond strength. data obtained from the current study showed that, in the bonding group, the control subgroup showed the highest sbs mean value compared to icon and proseal subgroups; however, the difference was not significant. similarly, in rebonding group, the results showed a non-significant difference among the groups and the correspondent subgroups although proseal samples showed the highest sbs values. it has been shown that the surface irregularities created during adhesive removal may cause increase in the physical area and provide microscopic holes. (45) this may result in multiple dead spaces that entrap oxygen especially in the deeper pits. it has been suggested that oxygen may has a plasticizer effect and result in a decline in the physical properties of the polymer. furthermore, oxygen is known to interfere with the polymerization reaction and, results in an incomplete polymerization of the adhesive (46); this has an adverse effect on the adhesion characteristics and, eventually, results in a reduction in the mechanical properties of the resin. this is especially true in the control group where the adhesive applied without preconditioners. however, when icon infiltrant and proseal applied, the sbs values were enhanced. the low viscosity of icon resin infiltrant together with the hydrophilic property of icon encourages a rapid capillary penetration into the pores and irregularities (47), provides a diffusion barrier within the enamel surface created by the rebonding procedure, filled the dead spaces and tags with the microscopic holes created by the adhesive removal procedure (48) and increases the sbs. on the other hand, it has been claimed that proseal showed high degree of polymerization (49) which, together with the increase in surface area and the formation of grooves and facets that alter the surface free energy and surface adhesion characteristics, enhance the adhesion.(50) regarding the ari scores, there were not marked effect of the application of the proseal and icon on the site of bond failure in either group. however, in proseal groups, 40% of the failure sites were away from the enamel surface where 75% of those were at the epa/adhesive interface. this has the advantage of preventing enamel trauma during debonding procedure as conclusion the application of icon or proseal during rebonding procedure did not compromise the sbs of the adhesive and may provide better protection to the enamel surface. reference 1. oesterle lj, shellhart wc. effect of aging on the shear bond strength of orthodontic brackets. am j orthod dentofacial orthop 2008; 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10(4): 236-40. 46. dall'oca s, papacchini f, chieffi n, goracci c, sadek ft, et al. composite to composite mictotensile bond strength in the repair of a microfilled hybrid resin: effect of surface treatment and oxygen inhibition. j adhes dent 2007; 9: 25-31. 47. chow ck, w cd, evans ca. in vitro properties of orthodontic adhesive with fluoride or amorphous calcium phosphate. int dent 2011; 583521. 48. paris s, hopfenmuller w, meyer-lueckel h. resin infiltration of caries lesions: an efficacy randomized trial. journal of dental research 2010; 89(8): 823-826. 49. eliades gc, caputo aa. the strength of layering technique in visible light cured composite. j prosthet. dent 1989; 61: 31. 50. radford dr, sweet sp, challacombe sj , walter j d. adherence of candida albicans to denture-base materials with different surface finishes. j dent 1998; 26: 577-83. الخالصه تكون البقع البيضاء حول حاصراتتقويم االسنان الثابت اثناء وبعد المعالجه التقويميه.انفصال احدى المشاكل الشائعه التي تواجه اخصائي تقويم االسنان هي الخلفية: جراءات عملية ه. خالل االحاصرات التقويميه هي المشكله االخرى التي كثيرا ماتحدث خالل فترة المعالجه التقويميه والتي تستوجب اعادة تثبيت الحاصرة التقويمي لى عيات كبيره من مينا االسنان ممكن ان تفقد بسبب االزاله الميكانيكيه للماده الالصقه مما يؤدي الى خشونة سطح مينا السن و الذي يساعد اعادة تثبيت الحاصره كم البكتريا. تجمع نية بعد عملية اعادة اللصق باستخدام الصقة على القوة القاصة لحاصرات التقويم المعد icon),(proseal)هو تقييم تأثير واقيات مينا االسنان ) الهدف من هذه الدراسة (heliosit)التقويم التقليدية ( الجراء اختبار القص 03مجموعتين متساويتين )العدد= تم جمع خمسين من الضواحك العلوية االولى من االسنان البشرية وتوزيعها عشوائيا الى الطرق والمواد: ( وهي فرع السيطرة السلبية )والتي استخدمت فيه الماده الالصقه 03قسمت كل مجموعة عشوائيا الى ثالث مجاميع فرعيه )العدد= قبل وبعد اعادة تثبيت الحاصرات. iconو فرع واقي المينا prosealفقط(, فرع واقي المينا 42لقياس القوة القاصه لالرتباط وذلك بعد مرور tinius olsenتم فك ارتباط الحاصرات التقويمية للمجموعة االولى )مجموعة الربط( باستخدام الة الفحص ال -tungesten ن نوع ساعة على عملية الربط. بعد فك االرتباط تم تحضير العينات لعملية اعادة الربط وذلك بازالة الالصق المتبقي باستخدام محفر التجهيز م carbide( مع نظام 03333باستخدام سرعة منخفضة)التبريد بالماء. بعد عملية اعادة الربط تم اختبار فك االرتباط باستخدام نفس الماكنة وذلك لقياس دورة بالدقيقة قيق خدام مجهر مجسم دالقوة القاصة لالرتباط للمجموعة الثانية )مجموعة اعادة الربط(. بعد فك االرتباط تم فحص كل من قاعدة الحاصر وسطح السن المناظر باست لتصاق المتبقي.وتم تسجيل مشعر اال في كال المجموعتين بالرغم من ان prosealو,iconاظهرت النتائج انه ليس هنالك فرق معنوي في القوة القاصة لفك االرتباط بين كل من السيطرة السلبية النتائج: يد مواقع االنفصال بعد عملية الربط واعادة الربط. بعد عمليةبعد اعادة الربط اظهرت زيادة)غير معنوية( قليلة في القوة القاصة لالرتباط. تم تحدprosealمجموعة ال ل سائد على مينا ن االنفصال بشكالربط وجد انه االنفصال كان بشكل سائد بين مينا السن والمادة الالصقة في المجاميع الفرعية الثالث. بينما بعد عملية اعادة الربط كا بين المادة الواقية والمادة الالصقة. 03ان االنفصال بنسبة %ك prosealالسن. في مجموعة المادة الواقية ال ممكن ان تحمي المينا من االصابة prosealالتؤثر على القوة القاصة لالرتباط باالضافة الى انه ال iconوالproseal وضع المواد الواقية لمينا السن ال :االستنتاج بعد فك االرتباط 16zainab f.docx j bagh college dentistry vol. 28(3), september 2016 radiological assessment oral diagnosis 99 radiological assessment of mandibular retromolar canal (mrmc) using cbct-radiographs in a sample of iraqi patients jamal abid mohammed, b.d.s., m.sc. (1) zainab h. al-ghurabi, b.d.s., m.sc. (2) abstract background: because of its clinical and surgical importance and lack of precise information about this rare and important anatomical landmark, this study was designed to detect the presence, configurations and length of mandibular retromolar canal (mrmc) with aid of cbct visualization. materials and methods: in this retrospective study the data was obtained from specialist health center in al-sadder city in baghdad for (100) patients with 200 inferior dental canal, all of them referred to cbct scan (kodak 9500, french origin). the scanning was done with tube voltage 90 kvp, tube current with 10ma and exposure time was 10 s., the field of view was measured with 5cm x 3.7cmwith 0.03mm voxel size results: in the present study the prevalence of mrmc was 12% , 2 patients have ( two ) bilateral mrmc and 10 patients have a unilateral canal, there was asignificant difference between two sides (left and right), the right side was 64.29% and left 35.71%, regarding to gender also there was a significant difference , female 33.3% and male 66.7%. in this study there were three types of mrmc and there was a significant difference between them, the mean length (hight) was 11.78 mm and mean horizontaldistance from canal to distal surface of the second molar was 18.5 mm. conclusions: mrmc also detectedin this study within the global percentage and configurations and should be taken with consideration in oral surgical procedures and radiological interpretations. key words: retromandibular canal, anatomical variation, cone beam computed tomography. (j bagh coll dentistry 2016; 28(3):99-103). introduction details and fine knowledge of anatomical structures and anatomical variations are important for surgeon and radiologist and since there are important surgical procedures in the posterior region of the mandible such as insertion of dental implant, sagittal split osteotomy, bone harvesting procedures, and removal of impacted third molar (1,2), so identification of the anatomical variations which may present in this area should be precisely studied. however mandibular retromolar canal (mrmc) is a rare anatomic variation in the posterior mandibular region (3,4). this canal is believed to contain neurovascular bundle which supply additional innervations to the mandibular molars, the probability of injury to these vessels could be happen during surgery is present (1,5,6), so clinicians should be depend on radiographic examination to identify mrmc before surgical procedures involving the posterior mandibular area. although panoramic radiograph is acceptable in general scanning and evaluation of the jaw, but it still give us two dimension, overlap and poor resolution image (7,8). identification and localization of mrmc on panoramic radiograph may be difficult or not accurate because of the mandible ramus region would overlap with the opposite side and superimposition of the soft tissue, magnification (1) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2) lecturer, department of oral diagnosis, college of dentistry, university of baghdad geometric distortion can led to limitation in identification of this structure recently cone beam computed tomography (cbct) is well established as an alternative technology in the imaging of oral and maxillo facial region (9), cbct supply three dimension (3d), undistorted image for teeth and surrounding structure with high accuracy, so it give very well visualization of the anatomical structure of bone that enable us to visualize the inferior dental canal and any variation with it (10). because of its clinical and surgical importance and lack of information about this rare and important anatomical structure, this study was designed to detect the presence, types and prevalence of mrmc with aid of cbct visualization. materials and methods patients in this retrospective study the data was obtained from specialist health center in alsadder city in baghdad for (100) patients scan37 male and 63 female with 200 hemi-mandible, all of them referred to cbct for different diagnostic purpose, radiographic were examined to identify the presence or absence of mrmc and its configuration according to patil et a (24). this study begins at february 2014 to december 2015. this study had been approved by college of dentistry\ university of baghdad, every patient informed about research and they sign for this. j bagh college dentistry vol. 28(3), september 2016 radiological assessment oral diagnosis 100 imaging the scanning was done with (kodak 9500, france) tube voltage 90 kvp, tube current with 10ma and exposure time was 10 s., the field of view was measured with 5cm x 3.7 cm with 0.03mm voxel size. . mrmcs were scanned or diagnosed with three multiplanar views, coronal, sagitta,and axial, in addition to reconstructed panoramic view. the cbct radiograph (sagittal, panoramic views) of the mandible were viewed for the presence or abscence, configuration and types according to the direction of the canal. linear measurements (mm) were taken by using the sagittal view of the cbct images ,for the canal length (height ) the distance from the orifice to its origin from the upper border of the canal,and for horizontal distance from the mesial surface of the retromolar canal to the distal surface of the lower second molar (figure-1,b). bilateral sides of the mandibleradiographs (cbct)were evaluated to determine presence, abscence,cofiguration and position of the mrmc. image evaluation all radiographs were evaluated toensure the presence, absence of mrmc and its type (cofiguration) obtained by agreement between oral surgeon and oral and maxillofacial radiologist for consensus agreement. statistical analyses the identification, measurements (means, range) and standard deviation supjected to statistical analysis using spss 16 for statistical analysis and use excel under windows xp: -desicrptive statistic: mean, sd, range, minimum and maximum. -inferential statistcs: pearson's chi-square test and z-score test. results in this study, according the accuracy of cbct the mrmc was found in 12 of 100 patients (12%), of which 5 on the left side (35.71%), 9 on the right side (64.29%) (table 1), two of them have (two) bilateral mrmc and 10 have a unilateral mrmc (table 2) and (table 4). there was a significant difference between left and right sides, the right side was (9) 64.29% and left (5) 35.71% (table 4). regarding to gender also there was a significant difference between female (4) 33.3% and male (8) 66.7%. in this study there were three types of mrmc and there was a significant difference between them, the mean length (hight) was 11.78 mm and the mean horizontaldistance from canal to distal surface of the second molar was 18.5 mm. after scanning it was found that, there were three configuration of mrmcs which involve: type one,the mrmc was emerge from the inferior dental canal and return to retromolararea fig 8 (c), type two, itemerges from inferior dental canal and direct upword (verticaly) fig 8 (b) and type three emerge from the inferior dental canal and directed medially toward the teeth (figure-8 a). table 1: number and percentage of patients patients no. % male 63 63% female 37 37% total 100 100 table 2: distribution of patients with unilateral/bilateral occurrence of mrmc patients no. % bilateral 2 16.67 unilateral 10 83.33 total 12 100 table 3: distribution of affected sample according the gender patients no. % male 8 66.7 female 4 33.3 total 12 100 table 4: distribution of mrmc canals according to side side no. % left 5 35.71 right 9 64.29 total 14 100 *chi-square =9.983 p=0.002 p<0.05 significant table 5: distribution according to canal type types males females comparison no. % no. % z-test p-value type 1 1 14.29 4 57.14 -1.67 0.095 type 2 4 57.14 2 28.57 1.08 0.28 type 3 2 28.57 1 14.29 0.65 0.516 total 7 100 7 100 z score test j bagh college dentistry vol. 28(3), september 2016 radiological assessment oral diagnosis 101 table 6: length (vertical) of mrmc, and horizontal distance (mm) linear measurements length horizontal mean 11.78 18.5 sd 5.58 7.38 min 7 9 max 28 30 range 21 21 fig. 1: cbct, reconstructed panoramic view show type3 of mrmc which emerge from the inferior dental canal and directed medially toward the teeth fig. 2: cbct, reconstructed panoramic view show type2 of mrmc which emerge from the inferior dental canal and directed upward fig. 3: cbct sagittal view show type1 of mrmc which emerge from the inferior dental canal and directed to retromolar area fig. 4: cbct coronal view show the inferior canal and mrmc fig. 5: cbct cross section show the inferior canal and mrmc discussion the present study documented the presence of mrmc in this iraqi population sample, and the present percentage (12%) of this canal(mrmc) somewhere within the range reported in other studies related to many different populations like, turkish (21), italian (4), indian (22), brazilian (23) and japanese (24). the incidence of mrmcs in osseous and cbct studies has been found to range from 6.1%-72% among different populations (11-17) and this difference can be related to types of the studies for detection of the canal ,different samples used, hereditary and environmental reasons. regarding the gender, this result (table 1, 3) showed that mrmc more common (significant) in males than females, the male percentage (66.7%) which was higher than female percentage (33.3%) as clear in table 3, there was a significant difference (p value <0.005), and this result is come in accordance with meera (19) and in disagreement with arx et al. (15,20,24) in which they found there was no significant difference in gender although the female number was more j bagh college dentistry vol. 28(3), september 2016 radiological assessment oral diagnosis 102 than male, and this may be because race difference or sample distribution between the two studies, reflecting that no agreement on gender prevalence because of the different results of many reports regarding this canal. regarding the side( left and right),in this study, it was found a significant difference between the two sides, the left side was 35.71% while right side percentage was 64.29% (tables 2 and 4). 2 patients (16.67%) have bilateral (two) mrmcs and the remaining 10 (83.33%) have a unilateral (one) (table 2 ) , this result was neer to many studies (15-17), all these studies found that, the unilateral side involvement with mrmc was higher than bilateral sides, this come in accordance with arx et al. (15). in the current study, three types of mrmcs were observed according to their configuration and direction: type 1 emerges from inferior dental canal and return to retromolar area fig 3, type 2 directed vertically from inferior dental canal fig. 2 and type 3 directed medially toward the teeth after emrging from inferior dental canal (fig 1). in coronal view and cross section, mrmc type couldnt recognized only the orifices of the canals (fig 4 and 5) respectly. reviewing of many of the recent studies (15,2426) using cbct for mrmc evaluation regarding the types of those canals reveal thatthere were no agreement about the description of the mrmc patteren, recording a varieties ranging from three to nine types and subtypes ,so from the findings of these studies and the current study we can conclude that there was no consensus descriptive dominant pattern applied to describe this anatomical landmark using the radiographic imaging, reflecting that there was a lot of different configurationsrelated to this anatomical landmark which need further investigations . this study shows that, type 1 found in 5 (35.7%) patients, type 2 found in 6 (42%) patients and type 3 (21.4%) found in 3 patients as clear in (table 5) with a significant difference in the prevalence among these three types (table 5) in a very recent study (26) with large sample using cbct they found nine types of mrmc ,but more than half of these canals in their study was in accordance with the current study regarding the predominance of type one and type two. regarding to the measurements of the canals, the length was measured from the origin of the mrmc from inferior dental canal to the end of it at crest of the bone, the mean length was11.78mm with range (7 to 28) mm, while the horizontal distance was measured from the mesial surface of the canal to the distal side of the second molar, the mean distance measurement was 18.5mm with rang (9 to 30)mm, as clear in (table 6), these measurements was higher than other studies (11,14, 15,20). the cause of these difference may be explained on that, these studies measure the reteomolar foramen rather than mrmc and someauthors measure the horizontal distance to the third molar or to the anterior border of the ramus of the mandible. references 1. naitoh m, hiraiwa y, aimiya h, ariji e. observation of bifid mandibular canal using cone-beam computerized tomography. int j oral maxillofac implants 2009; 24: 155-9. 2. bilecenoglu b, tuncer n. clinical and anatomical study of retromolar foramen and canal. j oral maxillofac surg 2006; 64: 1493-7. 3. gadbail ar, mankargadbail mp, hande a, chaudhary ms, gondivkar sm, korde s, et al. tumor angiogenesis: role in locally aggressive biological behavior of ameloblastoma and keratocystic odontogenic tumor. head neck 2013; 35: 329-34. 4. lizio g, pelliccioni ga, ghigl g, fanelli a and marchetti c. radiographic assessment of the mandibular retromolar canal using cone-beam computed tomography. acta 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retromolar foramen of the human mandible. am j physanthropol 1987; 73: 119-28. 12. ikeda k, ho kc, nowicki bh, haughton vm. multiplanar mrand anatomic study of the mandibular canal. ajnr am j neuroradiol 1996; 17: 579-84. 13. pyle ma, jasinevicius tr, lalumandier ja, kohrs kj, sawyer dr. prevalence and implications of accessory retromolar foramina in clinical dentistry. gen dent. 1999; 47: 500-3. 14. von arx t, hanni a, sandi p, buses d, bornstein mm. radiographic study of the retro mandibular canal: an anatomic structure with clinical importance. joe 2011: 37(12). 15. bilecenoglu b, tuncer n. clinical and anatomical study of retromolar foramen and canal. j oral maxillofac surg 2006; 64:1493–7. j bagh college dentistry vol. 28(3), september 2016 radiological assessment oral diagnosis 103 16. priya r, manjunath ky. retromolar foramen. indian j dent res 2005; 16:15–6. 17. bilecenoglu b, tuncer n. clinical and anatomical study of retromolar foramen and canal. j oral maxillofac surg 2006; 64:1493–7. 18. meera j, ranankrishma a, bindhu s, rani n, meril a. prevalence of retromolar foramen in human mandible and its clinical significance. int j anat res 2014; 2(3): 553. 19. akhtar j, parveen s, madhkar p, fatima a, kumar a, kumar b, sinha r. morphological study of retromolar foramen and canal in indian dried mandible. j evolution of medical and dental sci 2014; 3(58): 13142-51. 20. orhan k, orhan s, aksoy, et al. evaluation of perimandibular neurovascularization with accessory mental foramina using cone-beam computed tomography in children. j craniofac surg 2013; 24: e365–e369. 21. priya, manjunath ky. retromolar foramen. indian j dental res 2005; 16: 15–16. 22. zavando sm, cant´ın l. retromolar canal and foramen prevalence in dried mandibles and clinical implications. intern j odontostomatol 2008; 2: 183–7. 23. patil s, matsuda y, nakajima k, araki k, okano t. retromolar canals as observed on cone-beam computed tomography: their incidence, course, and characteristics. oral surg oral med oral pathol oral radiol 2013; 115: 692-9 24. han ss, hwang ys. cone beam ct findings of retromolar canals in a korean population. surg radiol anat 2014: 36: 871-9 25. sisman y, ercan-sekerci, payveren-arıkan m, sahman h. diagnostic accuracy of cone-beam ct compared with panoramic images in predicting retromolar canal during extraction of impacted mandibular third molars. medicina oral, patologia oral cirugia bucal 2015; 20: e74–e81. journal of baghdad college of dentistry, vol. 34, no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 51 research article effect of melatonin supplementation on the gingival health and lipid profiles in obese periodontitis patients hussam sami ismail 1, maha sh. mahmood 2,* 1 master student, b.d.s, department of periodontics, college of dentistry, university of baghdad 2 professor, b.d.s., m.sc. department of periodontics, college of dentistry, university of baghdad. * correspondence: maha.shukri@yahoo.com abstract: background: obesity increases the host’s susceptibility by modulating the immune and inflammatory systems in a manner that predisposes to inflammatory tissue destruction and leaves an individual at greater risk of periodontitis. melatonin is a pineal secretory product involved in numerous actions, such as regulation of internal biological clocks and energy metabolism, and it functions as an antioxidant and antiinflammatory agent. there exists a substantial amount of evidence supporting the beneficial effect of melatonin supplementation on obesity and its complications. aim of the study: to investigate the effects of systemic melatonin intake on periodontal health status and lipid profiles in obese periodontitis patients. subjects and methods: subjects included in the study were distributed into the following groups: group i, 20 subjects with normal weight and healthy periodontium (controls) not subjected to any treatment. group ii: 30 obese periodontitis patients subjected to scaling and root planing (srp) only. group iii: 30 obese periodontitis patients subjected to srp and supplemented with 5mg melatonin tablets for 1 month. study groups subjected to estimation of plaque index (pli), bleeding on probing (bop), cholesterol (chol), triglycerides (tg), high-density lipoprotein (hdl) and low-density lipoprotein (ldl) at baseline and after 4 weeks recall visit. results: regarding the clinical parameters, the second visit exhibited decreasing in all parameters in both study groups except bop score 0 were it increased significantly. regarding lipid profiles, the second visit showed decreasing in all profiles except hdl where it increased in both study groups with a significant difference. all correlations between lipid profiles in recall visit in both study groups exhibited a positive significant correlation between chol and tg, chol and ldl, ldl and tg in group iii. in group ii all results exhibited a positive significant correlation, whereas the only strong negative correlation was found between chol and hdl, hdl and ldl. conclusion: daily supplementation with 5mg melatonin tab significantly improved periodontal health and reduced chol, tg, ldl with increasing hdl. keywords: melatonin, lipid profile, obese periodontitis patients. introduction periodontitis is defined as an inflammatory disease of the supporting tissues of the teeth. the inflammatory condition is induced by microbial dysbiosis, resulting in progressive destruction of the periodontal ligament and alveolar bone (1). obesity increases the host’s susceptibility by modulating the immune and inflammatory systems in a manner that predisposes to inflammatory tissue destruction and leaves an individual at greater risk of periodontitis (2). obesity has been postulated to reduce blood flow to the periodontal tissues and promoting the development of periodontal disease (3). periodontal blood vessels received date :1-11-2021 accepted date :7-12-2021 published date: 15-3-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/ by/4.0/). https://doi.org/10.26477/jbcd. v34i1.3092 mailto:maha.shukri@yahoo.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3092 https://doi.org/10.26477/jbcd.v34i1.3092 j. bagh. coll. dent. vol. 34, no. 1. 2022 ismail and mahmood 52 in obese persons show a thickening in their innermost membrane, which indicates diminished blood flow in the periodontium (4). one of the reasons for the association between obesity and periodontal disease include the social stigma associated with obesity in younger adults. a greater source of chronic stress found in obese young individuals than in older adults is considered more acceptable. stress and how an individual copes with stress have been shown to increase a person's risk for periodontal disease (5). using the classification and regression tree (cart) method, it has been suggested that obesity is second only to smoking as the strongest risk factor for inflammatory periodontal tissue destruction (6). a study of the fourth korean national health and nutrition examination survey found that abdominal obesity is significantly correlated with periodontitis (7). despite these common inflammatory-mediated mechanisms, the specific underlying biological pathways linking both diseases are not well characterized. some authors have suggested the possible influence of alterations in the circadian cycle since significant reductions in the melatonin hormone levels were reported in experimental studies in both, obesity and periodontitis (8). in fact, when melatonin was administered in obese subjects, significant reductions in systemic pro-inflammatory biomarkers together with reductions in body weight and adipose tissue deposits were reported (9). melatonin participated in homeostasis and metabolism of energy through activation of brown adipose tissue and enhance energy expenditure (10). multiple studies reported that melatonin significantly increases hdl level and decrease tg and hdl level in addition to increased cholesterol catabolism (11). materials and methods this study was conducted in al-diwanyah dental specialized center at the department of periodontics, all subjects were collected from december 2019 to march 2020. this study approved by the ethical committee at the college of dentistry, university of baghdad, follow the roles of tokyo and helsinki for human (reference no.128619 in 28/11/2019). the study sample consisted of 80 males and females individuals with age ranged between 24-55 years, all subjects enrolled voluntarily to the study after signing an informed consent sheet to participate in research. all subjects were submitted to a questionnaire including their name, age, total medical history, dental history, their bmi, if they were subjected to any diet regimen, sleep nature, smoking, drinking alcohol, followed by a complete examination of clinical periodontal parameters (pli, bop). the sample was divided into 3 groups according to their bmi, periodontal health status, and melatonin supplementation. group i (20 subjects) (controls) was the normal weight group and healthy periodontium, their bmi was (18.50 24.99) this group presents at the baseline only for examination of clinical periodontal parameters (pli, bop), lipid profile (chol, tg, hdl, ldl), don’t exposed to any periodontal therapy., group ii (30 patients) have obesity, (bmi was ≥30.00) (12) designed to have latest sleep, generalized stage iii periodontitis don’t follow any diet regimen. this group presents at baseline and after a one-month recall visit for determination of clinical periodontal parameters (pli, bop), lipid profiles (chol, tg, hdl, and ldl) in pre and post periodontal treatment with scaling and root planing only without melatonin supplementation. the third group (30 patients) have obesity (bmi was ≥30.00) designed to have latest sleep, generalized stage iii periodontitis don’t follow any diet regimen. this group presents at baseline and after a one-month recall visit for determination of clinical periodontal parameters (pli, bop), lipid profiles (chol, tg, hdl, ldl) in pre and post periodontal treatment with scaling and root planing with melatonin supplementation 5mg tablet for 1 month (now, usa). all individuals were instructed not to eat for at least 12 hr. before taking the sample. blood samples (8ml) were drowned from antecubital vein by using disposable syringe size 10mm and pushed directly into the gel tube. the tube was centrifuged at 3000 rpm for 10min to obtain serum. the extracted serum was divided by using micropipette into plain tubes and put in colling box to send into the laboratory were stored in 80c in a deep freeze in al-diwanyah general medical laboratory. following one month, all individuals (except controls) were returned to perform the same manner of collection. the second visit was determined after one month and involved only group ii and group iii. clinical periodontal parameters involving (pli, bop,) was recorded and the same manner for blood collection and storing was performed for all patients. after completion of the sample, the frozen serum was thawed at room temperature before analysis for determination of lipid profiles by using a spectrophotometer (cecil instrument limited ce 7200, england). the participants were examined intraorally to determine the plaque index (pli) and (13) bleeding on probing (bop) (14). j. bagh. coll. dent. vol. 34, no. 1. 2022 ismail and mahmood 53 results all variables including clinical periodontal parameters (pli, bop) were tested for normality using the shapiro-wilk test at p value greater than 0.05 and they were normally distributed table 1: intraand inter-comparisons of pli among groups and visits using one way analysis of variance anova, paired sample t-test and independent sample t-test. pli groups base line 1 visit recall visit paired test p value es control mean 0.455 ±sd 0.048 group ii mean 2.491 1.777 25.890 0.000** 3.342 ±sd 0.237 0.229 group iii mean 2.556 1.564 30.233 0.000** 3.903 ±sd 0.171 0.173 statistics ( f or t) 978.536 4.074 df 2 58 p value 0.000 hs 0.000 hs es 0.962 1.050 table 2: multiple comparisons of pli in the baseline visits between groups using games-howell. dependent variable (i) groups (j) groups mean difference (i-j) sig. pli control without melatonin -2.036 .000 ** with melatonin -2.101 .000 ** without melatonin with melatonin -.065 0.449 the findings in tables 1 and 2 illustrated that pli was found to be higher in group iii than other groups followed by group ii with least in the control one. further analysis of multiple comparisons indicated that there is no significant difference between the two study groups while when compared each one with control, results were found to be a highly significant difference. regarding the second visit, pli appeared to be higher in group ii than that of group iii. there was a decrease in pli (1.564±0.1) and (1.777±0.2) in group iii and in group ii respectively with a highly significant difference with more effect size and variability in group iii than that of group ii. table 3: statistical test of bop among groups and in each visit using independent sample t. groups bop1, baseline bop1, recall visit bop1 pre-bop1 post , paired t-test df es without melatonin mean 63.267 41.60 12.619 29 1.629 ±sd 6.443 8.27 with melatonin mean 65.467 28.267 30.564 29 3.946 ±sd 6.822 5.564 t 1.284 7.327 p value 0.204 0.000 hs findings in table 3 illustrated that in baseline visits bop was found to be higher in group iii than that of group ii with no significant difference. regarding the second visit, all results demonstrated highly significant differences between the two groups. the changes of bop from baseline to recall visits indicated that there was decrease for bop score 1 with more effect size and variability for group iii (bop1: 3.946) than that group ii (bop1: 1.629). j. bagh. coll. dent. vol. 34, no. 1. 2022 ismail and mahmood 54 table 4: statistical test of lipid profile among groups and visits (inter and intra comparisons) using one way anova, independent and dependent sample t-test. the results in table 4 demonstrated that in baseline visit, all lipid profiles were found to be highest in group iii followed by group ii with the least value in the control group. hdl level showed an exception of that, in which the control group has the highest value other than other groups followed by group iii and the least value found in group ii. in the second visit, the cholesterol and hdl levels were found to be lower in group ii than in group iii. the opposite findings in triglyceride and ldl levels were found to be higher in group ii (302.973) than in group iii (297.617). all lipid profiles were found to be lowered between visits in each group with significant differences except for hdl were it showed to be higher with significant differences in each group with greater effect size and variability for group iii. table 5 clarified further analysis in the multiple comparisons of lipid profile in the baseline between groups. there was no significant difference in lipid profile between group iii and ii while when compared each one with the control group, the results were highly significant difference. hdl paired t-test p value ldl paired t-test p value pre post pre post 70.475 113.055 8.095 6.833 22.000 24.0 6.440 0.000 es= 0.831 135.0 132.4 6.142 0.000 es= 0.793 35.000 36.0 162.0 162.0 29.127 30.167 142.64 140.930 4.320 4.134 6.525 6.863 20.500 35.2 28.008 0.000 hs es= 3.616 133.2 111.6 21.976 0.000 hs es= 2.837 36.000 57.6 167.0 146.2 29.547 43.94 145.72 126.96 4.219 5.364 9.372 7.41 2 58 2 58 0.000 0.000 0.000 0.000 hs hs hs hs 0.917 2.88 0.551 1.956 groups cholesterol paired t-test p value triglyceride paired t-test p value pre post control mean 165.935 166.520 ±sd 14.553 11.486 without melatonin 0.751 0.459 es=0.097 245.0 240.0 4.946 .000 es= 0.639 377.0 375.0 mean 280.923 280.44 305.63 302.973 ±sd 36.623 36.761 36.775 37.042 with melatonin 7.804 0.000 hs es= 1.007 254.0 243.8 15.140 0.000 hs es= 1.955 399.0 381.0 mean 293.843 287.777 314.82 297.617 ±sd 39.961 40.115 38.718 37.372 df 2 58 2 58 p value 0.000 0.463 0.000 0.579 hs ns hs ns es 0.715 0.785 j. bagh. coll. dent. vol. 34, no. 1. 2022 ismail and mahmood 55 table 5: multiple comparisons of lipid profile in the baseline between groups by using games-howell test dependent variable groups groups mean difference p value cholesterol games-howell control without melatonin -114.988 0.000** with melatonin -127.908 0.000** without melatonin with melatonin -12.920 0.398 triglyceride games-howell control without melatonin -139.110 0.000** with melatonin -148.300 0.000** without melatonin with melatonin -9.190 0.616 hdl games-howell control without melatonin 41.348 0.000** with melatonin 40.928 0.000** without melatonin with melatonin -.420 0.923 ldl games-howell control without melatonin -29.585 0.000** with melatonin -32.665 0.000** without melatonin with melatonin -3.080 0.338 table 6: correlation between lipid profiles in recall visit in each group groups trig hdl ldl without melatonin cholesterol r .925 -.274 .668 p value .000 .143 .000 trig r -.150 .702 p value .430 .000 hdl r -.253 p value .177 with melatonin cholesterol r .972 -.696 .765 p value .000 .000.000 trig r -.700 .757 p value -.000 .000 hdl r -.478 p value -.008 results of table 6 showed that correlations between lipid profiles in group ii are the same as for baseline visits in the same group. there were significant correlations between cholesterol/triglyceride, cholesterol/ldl and between triglyceride and ldl while others had no correlations. the same results were found in group iii, in which all results were significantly correlated with each other. negative correlations were found between cholesterol/hdl, hdl/ldl, and triglyceride/ hdl. discussion regarding periodontal parameters, baseline visit showed a significant difference between control and study groups due to the fact that control subjects had healthy periodontium and good plaque control, which may attribute to their performance of good oral hygiene measures, and also by the fact of selection criteria of subjects in all groups. there was a highly significant difference of pli between the study groups at recall visit when compared with a baseline visit (p value ≤0.05) with more variability and effect size in group iii than group ii. instructions and motivation with the aid of scaling with root planing may results in a significant reduction in the means of pli in both study groups. in addition, when melatonin was used, it showed greater variability and significance when compared with the groups that were treated with scaling and root planning only. these findings agreed with the study confirmed by cutando et. al (15). similar finding agreed with these results confirmed by almughrabi et. al 2013 which showed that consumption of melatonin reduces the formation of bacterial biofilm, but this reduction was not significant compared with the control j. bagh. coll. dent. vol. 34, no. 1. 2022 ismail and mahmood 56 group. similarly, syrinath et. al showed that melatonin had the activity against streptococcus mutans, prevotella intermedia and porphyromonus gingivalis, which play a key role for biofilm formation and progression of periodontal diseases (16). bop score 1 was decreased from baseline to the recall visit. srp alone (without melatonin group) was effective in decreasing bop score 1, which agreed with previous studies (17, 18). while melatonin group exhibited more increasing in bop 0, indicating there was an increase in the percentage of gingival health. similar findings were reported by cutando et.al that topical application of melatonin in diabetic patients will significantly reduce bleeding and probing in active periodontitis through the down-regulation in pro-inflammatory mediators, and decreasing the rate of bone loss (19). another study by montero et.al (20) where agreed with the present study, they found that topically applied melatonin (1% orabase cream formula) for 20 days will significantly reduce clinical periodontal parameters involving bop score 1. the free radicals scavenging action of melatonin decrease gingival inflammation by its antioxidant effect. in addition, its efficacy on reduction of lipid uptake of microorganisms, regulation of duplication of bacteria and its effect to bind with iron, may explain this effect. regarding lipid profiles; at baseline visit there was highly significant differences between the control and study groups, which may attributed to their chosen criteria as obese subjects compared to systemically healthy control counterpart. according to f family test of statistical test (anova. repeated measures, between factors) of the gpower program, the complete sample size determined to be taken was 78 at 0.80 power on α error probability 0.05. so, 100 subjects decided to be included in this study to compensate for any anticipated dropout that described study sample that consisted of 80 males and females individuals with age ranged between 24-55 years, all subjects enrolled voluntarily to the study after signed informed consent sheet to participate in research. regarding the comparison between both study groups from baseline visit to recall visit, it demonstrated that there was a highly significant difference and variability about changes in lipid profiles in melatonin group than without melatonin group. the findings of the present study results were agreed with the previous study that showed administration of 5mg of melatonin for two months significantly decrease the ldl level in patient don’t exposed for a hypolipidemic diet for 3 months (11). another study reported that supplementation of melatonin significantly increase hdl level in peri-and postmenopausal women (27). the mechanism of promoting the effect of melatonin on lipid profile is attributed by stimulating brown adipose tissue activity (28). another mechanisms of melatonin on obesity are the enhancement of cholesterol catabolism by bile acids and increase the receptors of ldl to inhibit cholesterol synthesis (29, 30). regarding the correlation of recall visit, demonstrated that group iii showed a significant correlation between cholesterol/hdl, triglyceride/hdl and ldl/hdl, in which it agreed with the results of sun h et. al (32) (33), that reported the significant association of melatonin on reducing the level of cholesterol, triglyceride and ldl and increasing the level of hdl. however, our results have disagreed with others that showed no significant correlation of melatonin with hdl (28) (29). this discrepancy may be due to the diversity of dose and duration of melatonin therapy and the study population. therefore, more research is needed on larger study groups to investigate the precise effect of melatonin on anthropometric indices. according to the current research design, certain limitations have been addressed which need to be determined and recommended for future work. these may include: using different doses and duration of intake of melatonin supplements, larger sample size for statistical values to avoid the outlier effect, depending on more objective and reliable method for melatonin detection close to periodontal tissue other than serum such as gingival crevicular fluid, and using other designs such as parallel blinding or crossover clinical trial with local delivery to overcome the bias concerns. j. bagh. coll. dent. vol. 34, no. 1. 2022 ismail and mahmood 57 conclusion daily supplementation with 5mg melatonin tab may significantly improve periodontal health and reduced chol, tg, ldl with increasing hdl. this may be designed to use as an adjunctive in the treatment of periodontal 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(1) muna s. merza, b.d.s., m.sc., ph.d. (2) abstract background: oral lichen planus (olp) is a chronic inflammatory mucosal disease, presenting in various clinical forms who had regarded olp as a precancerous conditions in 1978 because of its potential with cancer. both antigenspecific and nonspecific mechanisms involved in the pathogenesis of olp. oral squamous cell carcinoma (oscc) is the most common malignant neoplasm of the oral cavity representing more than 94% of oral cancer. it occurs in different sites and has many etiological factors. cyclin dl is a proto-oncogene which consider as the key protein in the regulation of cell proliferation and its overexpression led to the occurrence and progression of malignant tumors.nf-kb p65 is a member ofnf-kb family of transcription factors that widely used by eukaryotic cells as a regulator of genes that control cell proliferation and cell survival, also plays a major role in inflammation. the aims of this study were to evaluate the immunohistochemical expression of cyclin d1 & nf-kb p65 in olp & oscc & to correlate the expression of the studied markers with the clinicopathological findings and with each other. materials and methods: fifty (50) formalin – fixed, paraffin – embedded blocks of both oral lichen planus (25 cases) & oral squamous cell carcinoma (25 cases) were collected proand retrospectively were included in this study. hematoxylin & eosin stain was performed for each block for reassessment of histopathological examination. an immunohistochemical staining was performed using anti cyclin d1 and anti nf-kb p65 monoclonal antibodies. results: of twenty five olpstudied cases , positive cyclin d1 & nf-kb p65 expression was found in (84%) and (88%)of the cases respectively. for oscc ,out of 25 studied cases ,positive cyclin d1 & nf-kb p65 expression was observe in (88%) and (96%) of cases respectively. statistically significant correlation between cyclin d1immunoreactivity and clinical presentation of olp was found. statistically significant correlation of cyclin d1 immunoreactivity with tumor grade andnf-kbp65 immunoreactivity with tumor stage in oscc cases was found. statistically a highly significant correlation between the expression of two studied markers in olp and oscc was found. conclusion: a highly significant correlation was seen regarding the expression of both markers with each other, suggesting their cooperative role in the pathogenesis of olp and oscc. keywords: olp, oscc, cyclin d1, nf-kb p65, immunohistochemistry. (j bagh coll dentistry 2014; 26(1):80-87). introduction oral lichen planus is a relatively common chronic inflammatory disease of oral mucosa with a prevalence rate of 0.5% 2.2% of the population. clinically, olp may assume a variety of morphological changes (1). the premalignant potential of olp is still debatable. malignant transformation has been estimated to occur in 0.5 – 2.9% of the olp patients. currently, there are no prognostic markers to identify which chronic olp lesions are at a higher risk for progression. thus, every olp patient should be monitored carefully to detect early cancer development (2). oral squamous cell carcinoma is the most commonly diagnosed oral cancer(3).it is the malignancy of stratified squamous epithelium. it remains a lethal disease in over 50% of the cases diagnosed annually, due mostly to late detection of advanced cancer (4). studying its molecular pathway may help in searching for molecular markers that might predict the clinical behavior of the tumor, which may not strictly related to tnm staging or histological grade (5). (1) m.sc. student, department of oral and maxillofacial pathology, college of dentistry, university of baghdad (2) assistant professor, department of oral and maxillofacial pathology, college of dentistry, university of baghdad cyclin d1, a 45 kd (kilo dalton) protein encoded by cyclin d1 gene (ccnd1) located on chromosome 11q13, is a part of the molecular system that regulates the cell cycle g1 to s transition (6). overexpression of cyclin d1 leads to shortening of g1 phase and less dependency on growth factors resulting in abnormal cell proliferation which in turn might favour the occurrence of additional genetic lesions (7). cyclin d1 expression has been studied in various carcinomas including oral squamous cell carcinomas. some studies have been carried out to correlate the expression of cyclin d1 with histological grading of this neoplasm (8).nuclear factor-kappa b is a transcription factor that induces the expression of various genes, leading to inflammatory reactions, embryonic morphogenesis, and anti apoptosis. in recent years studies suggested that nf-κb has been implicated in the regulation of cell proliferation, transformation, and tumor development. nf-κb was found to stimulate transcription of cyclin d1, a key regulator of g1 checkpoint control. nf-κb binding site in the human cyclin d1 promoter conferred activation by nf-κb as well as by growth factors. both levels and kinetics of cyclind1 expression during g1 phase were j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 81 controlled by nf-κb. recent advances in biological research have revealed that nf-κb can stimulate neovascularization(9). more ever continuous nf-kb activity protects cancer cells from apoptosis and in some cases stimulates their growth. therefore, many current anti tumor therapies seek to block nf-kb activity as a means to inhibit tumor growth or to sensitize the tumor cells to more conventional therapies, such as chemotherapy(10). this study aimed to:  evaluate immunohistochemical expression of (cyclin d1) and (nfkbp65) monoclonal antibodies in oral lichen planus and oral squamous cell carcinoma.  correlate the expression of the studied markers with the clinicopathological findings of olp and oscc.  correlate the expression of the studied markers with each other. materials and methods twenty-five cases , histologically diagnosed as oral lichen planus and other twenty –five cases, histologically diagnosed as oral squamous cell carcinoma were collected proand retrospectively from the archives of oral pathology department , college of dentistry, baghdad university, al-shaheed ghazi hospital and teaching laboratories department , medical city/ baghdad from (2004 – 2011). the clinicopathological information regarding age, sex, tumor site, clinical presentation, tumor grading and staging was obtained from the case sheets presented with the specimens. the clinicopathological characteristics of olp and oscc patients from which the specimens were taken are illustrated in table 1 and 2 respectively. four µm thick sections were cut and hematoxylin and eosin slides were prepared for histopathological reassessment. another 4 µm thick sections were cut for immunoshitochemcial staining with anti cyclin d1 and anti nfkbp65 monoclonal (abcam uk)). negative and positive controls were included in each ihc run.tissue blocks of small intestine were used for cyclin d1 and breast adenocarcinoma blocks were used for nfkbp65 (according to antibodies manufacturer). for immunohistochemistry, the sections were mounted on positively charged slides. slides were baked in hot air oven at 65°c overnight. sections were sequentially dewaxed through a series of xylene, graded alcohol and water immersion steps. table 1: clinicopathological findings of olp cases age frequency % 20-40 9 36 41-60 14 56 age>60 2 8 total 25 100 sex frequency % male 9 36 female 16 64 total 25 100 site frequency % buccal mucosa 23 92 lower lip 2 8 total 25 100 presentation frequency % white lesion 18 72 red lesion 4 16 white &red lesion 3 12 total 25 100 table 2:clinicopathological findings of oscc cases age frequency % 20-40 3 12 41-60 12 48 age>60 10 40 total 25 100 sex frequency % male 15 60 female 10 40 total 25 100 site frequency % tongue 11 44 buccal mucosa 7 28 lower lip 2 8 alveolar ridge 5 20 total 25 100 presentation frequency % white lesion 2 8 mass 9 36 ulcer 14 56 total 25 100 grade frequency % well 8 32 mod 14 56 poor 3 12 total 25 100 stage frequency % i 6 24 ii 3 12 iii 7 28 iv 9 36 total 25 100 antigen (ag) retrieving was done for both markers as recommended by the manufacturer. then endogenous peroxidase activity was blocked followed by blocking the nonspecific staining. primary abs (100 ml) were applied for each section. cyclin d1 and nf kappa b p65 were diluted into 1/1000 & 1/250 respectively. j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 82 after an overnight incubation and washing with phosphate buffered solution (pbs), secondary abs were applied, incubated and rinsed with a stream of pbs. primary abs were visualized with 3,3-diaminobenzidine (dab) chromogen, then counterstained with mayer's hematoxyline, dehydrated and mounted. evaluation of immunohistochemistry results: in both olp and oscc, the cells with clear brown nuclear staining were considered positive for cyclin d1 immunostaining whereas cells with clear brown cytoplasmic staining were considered positive for nf kappa bp65 immunostaining within a violet-blue tissue section background of hematoxyline staining. the immunoreactivity in tumor cells was classified and scored as follows: cyclind1, negative (-),( 1+) < 1% , (2+) 1-25% , 2650%, (3+) 50-75% and (3+) >75% (11). for nf kappa bp65, negative (-) no detectable immunostaining or basal immunostaining in<10%, (1+) mild immunostaining 10-30%.(2+) moderate immunostaining 30-50%. (3+) strong immunostaining >50%.(12). statistical analysis numerical values were used in this study for describing the variables which includes: no. mean, sd for age, cyclin d1 and nf kappa b p65. categorical variable which includes: sites, grade, gender and clinical presentation were described using no. and percentage. pearson correlation coefficient of correlation (r) was used to find the relation between two markers. anova test (analysis of variance) was used to detect differences for age and two markers .chi-square test the relationship between categorical variables. statistical analysis was done using spss (statistical package for social sciences) v17 (2008). results immunostaining of cyclin d1 was detected as a brown staining in the nucleus of target antigen cells, in olp cases positive ihc cyclin d1expression was found in 21 cases (84%),of which, 9cases (36%) showed score 2 immunostaining, 6 cases (24%) with score 3 , 4 cases (16%) score1 and 2cases (8%) score 4. figures (1,2). in oscc positive cyclin d1 ihc expression was found in 22 cases (88%), of which, 7cases (28%) with score 2 immunostaining, followed by 6 cases (24%) score 3, 5 cases (20%) score 4and 4cases (16%) with score1 .figures (3, 4, 5) correlating the positive expression of cyclin d1 with the clinicopathological findings of olp revealed statistically significant correlation with clinical presentation (p value= 0.025) , whereas non significant correlation was observed with other clinicopathological parameters. table(3). in oscc, results revealed statistically significant correlation regarding cyclin d1 expression in relation to tumor grade (p value =0.021),table(4).while, nonsignificant correlation was observed with other clinico pathological parameters. figure 1: positive brown nuclear immunostaining of cyclin d1 in olp (400x) figure 2: percentage frequency distribution of cyclin d1 expression in olp cases j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 83 figure 3: positive brown nuclear immunostaining of cyclin d1 in well differentiated oscc (100x) figure 4: positive brown nuclear immunostaining of cyclin d1 in poorly differentiated oscc (400x) figure 5: percentage frequency distribution of cyclin d1 expression in oscc cases immunostaining of nf-kbp65 was detected as a brown staining in the cytoplasm of target antigen cells. in olp cases, positive ihc expression was found in 22 cases (88%), of which, 6 cases (24%) showed strong immunostaining followed by 9 cases (36%) showed moderate immunostaining and 7cases (28%) with mild immunostaining figures(6 ,7). in oscc, positive nf-kbp65 ihc expression was found in 24 cases (96%), of which, 6 cases (24%) showed strong immunostaining followed by10cases (40%) with mild immunostaining and 8 cases (32%) showed moderate immunostaining . figures (8, 9, 10) figure 6: positive brown cytoplasmic immunostaining of nf-kbp65 in olp (100x) figure 7: percentage frequency distribution of nf-kbp65 expression in olp cases j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 84 figure 8: positive brown cytoplasmic immunostaining of nf-kbp65 in well differentiated oscc (400x) figure 9: positive brown cytoplasmic immunostaining of nf-kbp65 in moderately differentiated oscc (400x) figure 10: percentage frequency distribution of nf-kbp65 expression in oscc cases correlating nf-kbp65positive expression with the clinicopathological findings of olp cases revealed statistically non significant correlation. while in oscc there was statistically significant correlation with tumor stage (p value =0.037). table (5). on other hand, non significant correlation was observed with other clinicopathological parameters. table 3: correlation of cyclin d1 with clinical of oscc cases presentati on whit e lesio n red lesio n whit e and red total cd1 scoring 0 4 0 0 4 1 4 0 0 4 2 7 0 2 9 3 3 2 1 6 4 0 2 0 2 total 18 4 3 25 pearson chi-square valu e df asym p. sig. (2sided) 17.51 5 8 0.025 table 4: correlation of cyclin d1 with tumor grade of oscc cases grade well mod poor total cd1 scoring 0 3 0 0 3 1 3 1 0 4 2 1 6 0 7 3 1 4 1 6 4 0 3 2 5 total 8 14 3 25 pearson chisquare value df asymp. sig. (2sided) 18.035 8 0.021 table 5: correlation of nf-kbp65 with tumor stage of oscc cases stage i ii iii iv total nf scoring 0 1 0 0 0 1 1+ 5 1 2 2 10 2+ 0 2 4 2 8 3+ 0 0 1 5 6 total 6 3 7 9 25 pearson chisquare value df asymp. sig. (2-sided) 17.824 9 0.037 concerning the correlation of cyclin d1 and nf-kbp65 with each other, results of present study observed statistically a highly significant correlation between the expression of two markers in both olp (p value =0.007) and oscc (p value =0.003 ).tables ( 6 ,7). j bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 85 table 6: correlation of cyclin d1 withnfkbp65 expressions in olp nf-kb cyclind1 pearson correlation .526** sig. (2-tailed) 0.007 n 25 **. correlation is significant at the 0.01 level (2-tailed). table 7: correlation of cyclin d1 withnfkbp65 expressions in oscc nf-kb cyclind1 pearson correlation .563** sig. (2-tailed) 0.003 n 25 **. correlation is significant at the 0.01 level (2-tailed). discussion concerning the epidemiological parameters, including age, sex, site, clinical presentation, studies showed variable results; these inconsistent findings among different studies could be credit with the fact that the current study and some of the others are not an epidemiological type of studies, therefore the limited number and the random selection of the cases according to what is available preclude for definitive clinical findings. assessment of cyclind1 immunohistochemistry cyclin d1 is a positive regulator of cell cycle, and it exerts its effects on the rb pathway, lead to release the e2f transcription factors thereby allowing the cells to enter the s phase. overexpression of cyclin d1 may lead to shortening of g1 phase, increased cell proliferation and reduced dependency on growth factors. this may contribute to disturbance in the normal cell cycle control and mitogenic signaling pathways enhancing the cell transformation and tumorogenecity. thus, overexpression of cyclin d1 is thought to provide the tumor cells with a selective growth advantage (13). in oral lichen planus ,results of present study showed positive cyclin d1expression in 21 cases (84%) of olp studied cases.this finding was agree with (13,14) who found cyclin d1 positive expression in (71.67%) and (82%) respectively . this finding suggests that cyclin d1 may play important role in the occurrence , progression and carcinogenic process of olp (14). in oscc, 22 of 25 cases (88%) showed positive immunoreactivity to cyclin d1. this finding was in concordance with previous studies (15,16) who reported positive expression of cyclin d1 in (85.7%) and (95%) respectively. these studies support the role of cyclin d1 as a potential marker of proliferation and oncogenesis. assessment ofnf-kbimmunohistochemistry nf-kb is a signal transcription factor found to play an important role in aberrant gene expression and the malignant phenotype of scc, other studies revealed that expression of a very large number of genes is stimulated by nf-kb. these genes encode members of various classes of proteins that are involved in the inflammatory response such as cytokines, hla molecules, tumor necrosis factor, cellular adhesion molecules, acute phase proteins, and growth factors (17). in oral lichen planus, 22 (88%) of olp studied cases showed positive immunoreactivity to nf-kbp65.this finding was agree with (13,18) who found nf-kbp65 positive expression in (85%) and (93%) of olp cases respectively. similarly, (19) found positive nf-kbp65expression in (68%) of oral premalignant cases. in previous iraqi study, positive nf-kappa bp65 expression was found in 83.8% of the studied oral dysplastic lesions with low expression score observed in normal oral mucosa indicating the role of this factor in transition from normal oral mucosa to premalignant lesions mostly through prevention of apoptosis (20). in oral squamous cell carcinoma, the results of present study showed positive immunoreactivity to nf-kbp65in 24 of 25 cases (96%). this finding come in accordance with(20,21), who found that nf-kbp65was expressed in (100%) and (80%) of oscc cases respectively. moreover, (19,22) also found that nf kbp65was expressed (68%) & (78.38%) of oscc cases respectively. increased activation of nf-kb has been shown to occur in premalignant dysplastic lesions and approximately 85% of hnsccs, indicating it is an early event in carcinogenesis and the association of strong immunostaining with increased rate of malignant progression of dysplasia might shed light on molecular basis of gene therapy of oral cancer (23,24).the variations observed in the immmunopositivity rate among different studies could be due to the antibodies used and the processing techniques performed, as well as the heterogeneity of olp&oscc which could be attributed to the epidemiological or biological differences between countries and population. assessment of the correlation between cyclin d1and nf-kbp65 ihc expression in olp and oscc nf-κbp65 was found to stimulate transcription of cyclin d1, a key regulator of g checkpoint control. two nf-κb binding sites in the human cyclin d1 promoter conferred activation by nfj bagh college dentistry vol. 26(1), march 2014 immunohistochemical oral diagnosis 86 κb as well as by growth factors. both levels and kinetics of cyclin d1 expression during g phase were controlled by nf-κb. moreover, inhibition of nf-κb caused a pronounced reduction of serum-induced cyclin d1-associated kinase activity and resulted in delayed phosphorylation of the retinoblastoma protein (25). it has been reported that on one hand cyclin d1can inhibits nf-κb transcriptional activity through a co repressor function (26 ),and on the other hand , nf-κb is activate the transcription of cyclin d1gene,which then increase the expression of cyclin d1 protein (27). furthermore, (28) found that the regulation of cyclin d1 transcription by ral gtpases is dependent on nf-κb activation and is mediated through an nf-κb binding site in the cyclin d1 promoter.despite variances in mechanism, it is well established that nf-κb are strong inducers of cyclin d1 gene expression (29-31). the present study showed statistically significant correlation between cyclin d1 and nf-κb in olp & oscc cases. similarly, (22) also found a correlation between cyclin d1 and nf-κb in oral leukoplakia and oral squamous cell carcinoma, moreover he reported that there was a significant correlation between the expression of nf-κb/p65 and cyclin d1 in the cancerization of oral leukoplakia, which played a cooperative role in cell proliferation and took part in the carcinogenesis of oscc. finally, the statistically significant correlation between cyclin d1 and nf-κb in olp & oscc cases observed in this study suggests their close and synergistic, cooperation and coactivation in premalignant & malignant lesions, therefore, they could be 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(1) lehadh m. alazzawi, b.d.s., m.sc., ph.d. (2) abstract background: epithelial salivary gland tumours are relatively uncommon and constitute a wide spectrum of variable morphologic and biologic entities. the cell proliferation / death balance is most important in the development of salivary gland tumours. the aim of this study was to examine the expression of pcna protein immunohistochemically and bax mrna gene using in situ hybridization techniques and to correlate between the clinicopathological features of salivary gland tumours with the expressions of pcna protein and bax mrna. materials and methods: forty nine formalin fixed paraffin embedded tissue blocks of epithelial salivary gland tumours were used in this study. haematoxylin and eosin stain was used for reassessment of the histopathologic diagnosis. the cell proliferation activity was examined by proliferating cell nuclear antigen (pcna) immunohistochemistry and proapoptotic cell death bax mrna gene was analysed by in situ hybridization techniques. results: immunohistochemical analysis show high expression of pcna and was noted in 8 of 12 pleomorphic adenoma cases (66.67%), 15 of 19 adenoid cystic carcinoma cases (78.95 %), 6 of 7 mucoepidermoid carcinoma cases (85.71%), and 3 of 5 adenocarcinoma case (60 %). significant difference was found between labeling index of benign and malignant salivary gland tumours, while no significant relationship was noted in labeling index between adenoid cystic carcinoma and mucoepidermoid carcinoma neither between mucoepidermoid carcinoma and adenocarcinoma. in situ hybridization detection show low expression of bax and was noted in only 3 cases of pleomorphic adenoma cases (25%), 10 cases in adenoid cystic carcinoma cases (52.63 %), however, mucoepidermoid carcinoma showed high expression of these markers than other salivary gland tumours, whereas adenocarcinoma show equal number of cases expressed both pcna protein and bax mrna. no significant relationship was demonstrated between the immunostaining pcna or bax and the morphological growth pattern or patient clinical profile. positive significant correlation was found between pcna and bax mrna in pleomorphic adenoma, adenoid cystic carcinoma, mucoepidermoid carcinoma and adenocarcinoma cases. conclusion: the high proliferative rate could explain the natural course of these tumours and the decreased expression of bax in salivary gland tumours indicate that loss of bax expression might give the tumour cells a double growth advantage because uncontrolled proliferation is combined with reduce cell death rate. the interaction may trigger a multistep process which is able to promote and may play a role in salivary gland tumour genesis, possibly by inhibiting the apoptosis mediated by bax. keywords: mucoepidermoid carcinoma, adenoid cystic carcinoma, pleomorphic adenoma, pcna, bax mrna. (j bagh coll dentistry 2014; 26(1):112-120). introduction the complexity of pcna functions are reflected by the history of its discovery and subsequent investigation. this protein was identified over 30 years ago as an antigen for an autoimmune disease in the serum of patients with systemic lupus erythematosus. two years later, another group found a 36-kda protein that was differentially expressed during the cell cycle and named it ‘cyclin’. later, it was shown that expression levels of pcna are associated with proliferation or neoplastic transformation (1-4). the control of dna replication is a key element in the proper functioning of a cell, and it may influence genome stability. dna replication is regulated mainly at the initiation step as a result of cooperation between different signalling pathways controlling the cell cycle (5,6). pcna a potential anticancer target forms a homotrimer (1) m.sc. student, department of oral maxillofacial pathology, collage of dentistry, university of baghdad. (2) assistant professor, department of oral maxillofacial pathology, collage of dentistry, university of baghdad. and is required for dna replication and numerous other cellular processes. pcna is synthesized in all stages of the cell cycle with a half-life of approximately 20 h and is elevated in early s phase to support cell cycle progression (5, 7). tumour cells, regardless of their origins, express higher levels of pcna. expression levels of pcna correlate positively and can serve as an independent prognosis marker (8). the bcl-2 gene family seems to act as a regulator of the apoptotic pathway. the two most important apoptosis regulating proteins of this family are most likely bcl-2 and bax (bax is a member of the proapototic family). loss of function mutations have been identified in the bax gene of human tumours. the expression of mutated bax protein may fail to release cytochrome c and increase the bax-bcl-2 ratio resulting in the escape from programmed cell death (9 11) because the programmed cell death function of bax is important to counteract tumour growth, they hypothesized that changed bax expression j bagh college dentistry vol. 26(1), march 2014 bax in situ cancer oral diagnosis 113 from normal tissue to primary tumours and metastases may provide additional information rather than only considering bax expression in primary tumours (12). thus, they addressed the biologic and clinical significance of changed expression from normal mucosa to primary tumours and metastases related to patients’ sex, age, tumour location, histologic stage, growth pattern, differentiation, and prognosis (13,14). a consistent feature in many studies is the positive correlation or association between apoptosis and proliferation, suggesting that they are mechanistically linked. one link relates to the fact that although apoptosis may be initiated in any phase of the cell cycle, the majority of cells undergo apoptosis primarily in the g1 phase of cycling cells (15,16). to our knowledge the present study is the first the first describing the expression of bax mrna in situ hybridization in epithelial salivary gland tumours. pcna protein and bax mrna gene expressions in relation to the clinicopathological profile in epithelial benign and malignant salivary gland tumours have not been reported previously. this study aimed to determine expression of proliferating cell nuclear antigen protein (pcna) immunohistochemically and the expression of the proapoptotic bcl – 2 – associated x protein (bax mrna) using in situ hybridization technique and to correlate between the clinicopathological features of salivary gland tumours with the expressions of pcna protein and bax mrna. materials and methods archival formalin – fixed, paraffin – embedded tissue blocks of 49 cases of salivary gland tumors diagnosed as (12) pleomorphic adenoma (pa), (7) mucoepidermoid carcinoma (mec) and (19) adenoid cystic carcinoma (acc), (5) cases of adenocarcinoma and two cases of each of acinic cell carcinoma, carcinoma ex pleomorphic adenoma (cxpa) and squamous cell carcinoma (scc) were obtained from the department of oral and maxillofacial pathology, oollege of dentistry – university of baghdad and other centers in baghdad dated from (1998 – 2006). sections of 5 µm thick of the paraffin embedded tissue were cut and stained with hematoxylin and eosin for histopathological examination. the mecs were graded according to auclair et al., 1992 (17). the histological types of acc diagnosed and an estimate was made of the percentage of each tumour depend on growth pattern into three types: cribriform, tubular and solid patterns (the case categorized by their predominant growth patterns, although two or more patterns can coexist in a single tumour) according to scheme of szanto et al. (18). adenocarcinomas were graded to scheme of auclair et al. (19). the other malignant types of salivary gland were excluded their grading because of minimal number of cases available during the time of collect the study sample. another 5 µm paraffin sections were cut and mounted on coated glass slides for in situ hybridization and immunohistochemical analysis. in situ hybridization staining method: the tissue slides were pretreatment solution (citric buffer) was heated in a beaker on a hot plate at 98c. to prevent buffer from evaporating, the beaker was covered with a glass cover. slides then transferred immediately to deionized water at room temperature and wash three times, 2 minutes each. to each tissue section, 2-3 drops of freshly diluted 1x protinase k solution were applied. then slides were incubated at 37c for 10-15 minutes. slides were dehydrated and dried by incubating them at 37c for 5 minutes then hybridization and detection by one drop of the working dna probe/hybridization solution was added on the tissue section. place a cover slip over each slide. be careful to avoid trapping any air bubbles and the slides were placed in an oven at 70c for 10 minutes to denature the secondary structure of rna. the slides were removed in a humid chamber and incubated at 37c for 24 hours to allow hybridization of the probe with the target nucleic acid, and then soaked in 1x detergent wash at 37c until the cover slips fall off. one to two drops of rnaase (15 ng/ml) were placed on tissue section. then slides were placed in a humid chamber and incubated at 37c for 30 minutes. slides were washed with protein block (prewarmed) at 37c for 3 minutes; three times. excess buffer from around the tissue section was wiped off carefully. then 1-2 drops of conjugate were added to tissue section and slides were kept in a humid chamber at 37c for 20 minutes final slides were incubated at room temperature (2537cº) for about 10 minutes, or until color development was complete. color development was monitored by viewing the slides under the microscope. a blue colored precipitate formed at the site of the probe in positive cells. color appeared after 3-5 minutes, usually reached sufficient development after 10 minutes. slides were counterstained using nuclear fast red. ish staining analysis of bax mrna color and distribution of stain: blue colored precipitate at the site of the probe in positive cells and the back ground of red stain belong to the counter stain (nuclear fast red) were noticed. j bagh college dentistry vol. 26(1), march 2014 bax in situ cancer oral diagnosis 114 four high power fields (hpf) 400x were evaluated for localization percentage of positive cells by counting 1000 cells (0% to 100% in 5% steps), the percentage of positively stained cells distributed as follows; 0 (-), <25% (+), 25% 75% (++), and >75% (+++), by using double blind scoring method (13). immunohistochemical method: antigen retrieval was done using citrate buffer (ph 6.0) by microwave digestion .endogenous peroxidase was blocked with 0.05% hydrogen peroxide for 30 min. after incubation with a 1:20 dilution of normal horse serum to reduce nonspecific binding, the slides were incubated overnight at 48c with primary antibodies against pcna (dako-patts, pc-10, 1: 50). secondary antibodies associated with a streptavidin–biotin– peroxidase method was used (dako a/s, strept ab complex duet, mouse/rabbit), complemented with diaminobenzidine as the cromogen. all slides were counterstained with hematoxylin. after each step the sections were washed with phosphate buffered saline. negative controls sections were obtained using non-immune serum instead of the primary antibody. samples of squamous cell carcinoma were used as positive control. immunoreactivity was classified as: (-) negative ≤5%, (+) low 6–25%, (++) moderate 26– 50% and (+++) high >50% of positive tumour cells, counting at least 1000 cells at high magnification (40x objective and 10x eyepiece) (20). intensity of staining was not considered for evaluation. the quantitative analysis of pcna positive cells were counted by two independent examiners. the pcna labeling index, value was reported as the percentage of the tumour cells staining per 1000 cells counted. the incidence of positive cells against the antibody was expressed as the labeling index which is a percentage of the positive tumour cells in the total number of tumour cells counted (21). statistical analysis data were analyzed by spss software for window 10. frequency and percentage was calculated for each parameter. the relationship among pcna, bax expression and clinicopathological types and histologic grade were assessed using chi – square x 2 test. mean ± s.d. was calculated for age and labeling index of pcna protein. statistical significance of differences was analyzed by using one – way analysis of variance (anova). the spearman correlation coefficient (r) was used between pcna protein and bax mrna gene among salivary gland tumours. the p ≤ 0.05 was considered statistically significant. results the positive reaction of pcna protein expression was observed in 8 cases (66.67%) of benign epithelial salivary gland tumours (pa) and 29 cases (78.38%) of malignant tumours. twelve cases of benign pa, the mean labeling index of pcna protein expression was 26.46±10.76 and range (15−48%) and 37 cases of malignant salivary gland tumour was 37.82 ± 20.12 and range (6.2−80). there was a significant difference between li of benign and malignant tumours. bax mrna expression give an intense blue – black color at the specific sites of the hybridized probe in positive test tissues and positive control and the background of red stain belong to the counter stain (nuclear fast red) was noticed. the specificity of the ish signal is reflected by the absence of positive ish signal in the negative control slides. the positive reaction of bax mrna expression was observed in 3 cases (25%) of benign salivary gland and 21 cases (56.76%) of malignant salivary gland. there is a significant difference statistically between benign and malignant cases for positive and negative expression of bax mrna. table (1 and 2) shows the positive cases of pcna protein and bax mrna expression in malignant salivary gland tumours in relation to their histological grading with the clinical findings of these cases. figures 1-3 show positive nuclear staining of pcna protein and figures 4-6 show localization of bax mrna gene. the positive case of acinic cell carcinoma with pcna protein was located in the palate, and the 2 cases of acinic cell carcinoma were positive (++ for each case) of bax mrna expression. the two positive cases of squamous cell carcinoma with pcna protein located in the tongue and submandibular gland, and one case of the two of squamous cell carcinoma showed positive expression of bax mrna. the 2 cases of carcinoma ex pleomorphic adenoma were positive for pcna protein expression and negative expression of bax mrna and located in the soft palate. the strong positive correlation was found between the pcna protein and bax mrna of pa (r = 0.999), where a positive correlation (r = 0.693) regarding the scoring of positively pcna protein and bax mrna expressed cases. the relation of tumour location (the major and minor salivary gland sites) between immunopositivity of pcna and bax mrna expression in the epithelial salivary gland tumours were shown in table 3. the li (mean value ± sd.) of positive expression of pcna versus bax staining rate in the epithelial salivary gland j bagh college dentistry vol. 26(1), march 2014 bax in situ cancer oral diagnosis 115 tumour were demonstrated in table 4. a tendency to increase the proliferative li was observed in cases of pa and acc with positive cases of bax expression whereas in mec the negative cases of bax expression showed high rate of li than those with positive expression and the same result was found in adenocarcinoma cases. discussion the epithelial salivary gland tumours are relatively uncommon lesions and salivary gland carcinomas are a heterogeneous group of lesions; represent a great number of diverse entities with histological patterns overlapping between different tumour pathologies complicating their diagnosis. pcna protein and bax mrna gene expressions in relation to the clinicopathological profile in epithelial benign and malignant salivary gland tumours have not been reported previously. the large number of histological types of salivary gland tumours makes them a very heterogeneous group of neoplasias, most of them rare. the relative frequency of malignant tumours has changed over years, due to the changes in diagnostic criteria and classification. the results of this study had been cited the palate were the most common site for minor salivary gland tumours, of which (20 "40.8 %" from 49 cases) occur in the palatal mucosa, through the figure was lower than that in the literature (22 -26). some anatomic sites were prone to the development of certain types of salivary gland tumours. the results of this study showed the parotid gland was the commonest site for benign salivary gland tumours, while the malignant tumours the commonest site were both the parotid and submandibular for major gland and palate for the minor glands. histological classification of malignant salivary gland tumours is well established as an important prognostic factor for both acc and mec. the three recognized histopathologic patterns of acc are cribriform, tubular and solid which determine the prognosis with cribriform being the most common and easily recognized pattern and solid the least common histopathologic subtype, the results of this study as well as others reports showed that the cribriform growth pattern variant is the most common type representing 80% of the cases (25, 27). mec is considered the most common malignant salivary gland tumours accounting for approximately one third of all salivary malignancies (28,29). in this study mec of submandibular glands were cited and being associated more frequently with lymph node. this though is not a constant finding but was shown in this study and this is in accordance with others (20, 22,26,27). most cases of mec conducted in this study were low grade lesions; in accordance with the results of literatures were high percentage (85 %) with low grade mec, favoring a good prognosis (28). the cell proliferation / death balance is of the important in the development of salivary gland tumour. in pcna – positive long – lived cells, the probability of accumulation of genetic abnormalities necessary for malignant transformation is increased and plays an important role in epithelial tumour development. the ihc demonstration of pcna allows an estimation of the growth fraction in tumour tissue and pcna can be detected in cells that have recently left the cell cycle which is caused by the prolonged half – life of this protein (5, 6). pcna has been used as a proliferation marker in different neoplasms in relation to clinical behaviour (8). li of benign epithelial salivary gland tumours had (26.46 ± 10.76) and increase in the malignant epithelial salivary gland tumours had (37.82 ± 20.1) and reach the level of significant statistically. indeed, li of the heterogeneous group of malignant epithelial salivary gland tumours had nearly the same value indicate the consistent aggressive behaviour of all epithelial salivary gland tumours, but mec showed highest pcna li (48.3 ± 26.5). interestingly, the results of this study showed that pcna expression increased as tissues progressed from cribriform to tubular and solid growth pattern of acc and from moderate to poorly differentiated adenocarcinoma indicate that pcna immunostaining can help to estimate the histological grade of malignant morphological growth pattern. the two cases of acc with neural invasion were positive to pcna expression and this result similar to others (29-33). the bcl – 2 family has been shown to play an important role in the regulation of apoptosis and modulation of cell cycle regulating proteins illustrating the crosstalk in mechanisms controlling cell death and proliferation (11). it has been shown that reduced bax mrna expression correlates with tumour progression in head and neck cancer (9). the expression of this study was observed in malignant salivary gland tumours irrespective of histological subtypes or morphological growth pattern and suggests that loss of bax expression may play a role in the development of epithelial salivary gland tumours. the overexpression of bax protein as a marker of induce apoptosis had been reported in limited studies to initiate tumour cell to apoptosis in salivary gland tumours using immunohistochemical methods for expression of j bagh college dentistry vol. 26(1), march 2014 bax in situ cancer oral diagnosis 116 bax protein in mec of salivary gland, therefore, in this study mec had a higher frequency of strong bax expression than acc and adenocarcinoma of salivary glands, but there was no significant difference and this is accordance with yin (34) and this colleagues that found bax protein expression in mec (97 %) were positive and this is not relate to that bax expression associate with better survival in mec because the negative cases were too few to be compared with positive group. in acinic cell carcinoma, the two cases expressed bax positive while the cases of cxpa expressed negative bax indicate that the former is a low – grade of malignancy behaviour and the latter is high – grade and aggressiveness behaviour with high proliferative rate (33). scc of salivary gland expressed one negative and another positive bax indicate this tumour had metaplasia of glandular cell to squamous cell, aggressive behaviour and differ from oral mucosal squamous cell carcinoma which was used as housekeeping, expressed bax positive, this is due to similarity in histological appearance and differentiation of squamous cell to form cell nest and produce keratin but differ in the etiology and pathogenesis of salivary gland that is prove a heterogeneous group of the salivary gland lesions. the enhancement of cell proliferation and promotion of cell survival via the inhibition of apoptosis is thought to be the key to the initiation and progression of cancers. either inactivation of pro – apoptotic pathway or activation of antiapoptotic pathway results in failure of apoptosis. this study found a positive strong association between pcna protein and bax expression in positive cases, scoring and intensity of expression in both benign and malignant salivary gland tumours and this is due to slowly growing of pa benign tumour (31) and a low – grade malignancy of epithelial malignant salivary gland tumours that conducted in this study. mec showed higher expression of these two markers than those of other salivary glands. this could be in part explained by the fact that most of mec were high grade tumours. while in acinic cell carcinoma had a minimal proliferative activity and active inhibitor activity of bax was detected in both cases and is convincing evidence with its low grade – malignancy of salivary glands (27) and in cxpa, the immunoreactivity of pcna protein with negative expression of bax among tumour cells of cx pa indicated that tumour cells are under their active division cycles. the pcna positivity rate was high in strongly bax positive group, in pa and acc, indicating a possible positive correlation between proliferation and death balance of the cell and the high pcna positive rate in the two bax negative cases of mec and adenocarcinoma may suggest that proliferative rate increase in absence of apoptotic pathway activation. . in conclusion: the high proliferative rate could explain the natural course of these tumours and the decreased expression of bax in salivary gland tumours indicate that loss of bax expression might give the tumour cells a double growth advantage because uncontrolled proliferation is combined with 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(ivsl). 28. rapidis ad, givalos n, gakiopoulou h, stavrianos sd, faratzis g, lagogiannis ga, katsilieris l, patsouris e. mucoepidermoid carcinoma of the salivary glands. review of the literature and clinicopathological analysis of 18 patients. oral oncology 2007; 43: 130-6.(ivsl) 29. wolfish e, nelson b, thompson l. sinonasal tract mucoepidermoid carcinoma: a clinicopathologic and immunophenotypic study of 19 cases combined with a comprehensive review of the literature. head and neck pathol 2012; 6:191–207. 30. nagao t, sato e , inoue r, oshiro h, takahashi rh, nagai t, yoshida m, suzuki f, obikane h, yamashina m and matsubayashi j. immunohistochemical analysis of salivary gland tumors: application for surgical pathology practice. acta histo chem cytochem 2012; 45: 269-82. 31. gorden-nunez ma, godoy gp, soares rc, souza lb, freitaz ra, queiroz lmg. immunohistochemical expression of pcna, p53 and bcl-2 in pleomorphic adenoma. int j morphol 2008; 26: 567-72. 32. lee s, kwon m, lee y, choi s, kim sy, cho k and nam sy. prognostic value of expression of molecular markers in adenoid cystic cancer of the salivary glands compared with lymph node metastasis: a retrospective study. world j surgical oncology 2012; 10: 266 -74. 33. saghravania n, nooshin m, jafarzadeh h. comparison of immunohistochemical markers between adenoid cystic carcinoma and polymorphous low grade adenoma. j oral sci 2009; 51: 509-14. (ivsl). 34. yin hf, okada n, takagi m. apoptosis and apoptotic-related factors in mucoepidermoid carcinoma of the oral minor salivary glands. pathology international 2000; 50: 603 – 9. j bagh college dentistry vol. 26(1), march 2014 bax in situ cancer oral diagnosis 118 figure 1: pleomorphic adenoma demonstrating nuclear immunostaining for pcna. original magnification 400x. figure 2: mucoepidermoid carcinoma. high grade the positive pcna staining in the tumour cell. original magnification 400x. figure 3: carcinoma ex pleomorphic adenoma demonstrating nuclear brown immunostaining for pcna. original magnification 400x figure 4: acinic cell carcinoma, black blue spots the localization of bax mrna gene. original magnification 400x. figure 5: adeniod cystic carcinoma cribriform growth pattern, black blue spots the localization of bax mrna gene. original magnification 400x. figure 6: adenocarcinoma, black blue spots the localization of bax mrna gene. original magnification 400x. j bagh college dentistry vol. 26(1), march 2014 bax in situ cancer oral diagnosis 119 table 1: the frequency and percentage of positively pcna protein ihc analysis according to histologic grading of malignant epithelial salivary gland tumours table 2: bax mrna gene ish analysis of positive cases according to histologic grading of malignant epithelial salivary gland tumours variable acc no. (%) 15 mec no. (%) 6 adenocarcinoma no. (%) 3 cribriform ( 6) tubular (6) solid (3) low (4) intermediate (1) high (1) well moderate(1) poor diff.* (2) age m ± s.d. 45.66+ 18.45 41.0+11.4 58 +13.11 42+20.2 51+0.00 65+0.00 36 + 0.0 41 + 4.242 sex male female 1(16.7) 5(83.3) 2(66.7) 5(83.3) 1(16.7) 1(33.3) 1(25) 1(100) 1(100) 3(75) 1(100) 1(50) 1(50) site major parotid submandibular sublingual minor palate hard soft tongue upper lip buccal mucosa 4(66.67) 1(33.3) 2(33.3) 3(50) 2(66.7) 2(33.3) 1(16.67) 1(25) 1(100) -1(25) 1(100) 1(25) 1(25) 1(100) 1(50) 1(50) tumour size 1t 2t 3t 4t 2(33.3) 2(33.3) 1(16.7) 2(66.7) 4(66.7) 2(33.3) 1(16.7) 1(33.3) 1(25) 1(100) 2(50) 1(25) 1(100) 1(100) 2(100) lymph node ve + ve 5(83.3) 6(100) 2(75) 1(16.7) 1(25) 4(80) 1(100) 1(20) 1(100) 1(100) 2(100) clinical stage i ii iii iv 2(33.3) 2(33.3) 1(16.7) 2(66.7) 4(66.7) 2(33.3) 1(16.7) 1(33.3) 1(25) 1(100) 2(50) 1(25) 1(100) 1(100) 2(100) variable acc no. (%) 10 mec no. (%) 5 adenocarcinoma no. (%) 3 cribriform (6) tubular (3) solid (1) low (3) intermediate (1) high (1) well moderate (2) poor diff.*(1) age m ± s.d. 42+12.07 48.33+12.58 44+0.0 51+16.52 51+0.0 65+0.0 52+22.63 28+0.0 sex male female 2(33.3) 2(66.7) 1(100) 4(66.7) 1(33.3) 1(33.3) 1(100) 1(100) 2(66.7) 2(100) 1(100) majorsite parotid submandibular sublingual minor palate hard soft tongue upper lip buccal mucosa 4(66.7) 1(33.3) 1(16.7) 1(33.3) 1(16.7) 1(33.3) 1(33.3) 1(33.3) 1(100) 1(100) 1(33.3) 1(33.3) 2(100) 1(100) j bagh college dentistry vol. 26(1), march 2014 bax in situ cancer oral diagnosis 120 table 3: coefficient of association correlation (r) between positive pcna protein and positive bax mrna cases of epithelial salivary gland tumours in relation to site. table 4: labeling index of positive pcna protein versus positive bax mrna cases of epithelial salivary gland tumours tumour size 1t 2t 3t 4t 1(16.7) 2(66.7) 2(33.3) 1(100) 3(50) 1(33.3) 1(33.3) 1(100) 2(66.7) 1(100) 1(100) 1(50) 1(50) lymph node ve + ve 5(83.3) 3(100) 1(100) 1(16.7) 3(100) 1(100) 1(100) 2(100) 1(100) clinical stage i ii iii iv 1(16.7) 2(66.7) 2(33.3) 1(100) 3(50) 1(33.3) 1(33.3) 1(100) 2(66.7) 1(100) 1(100) 1(50) 1(50) variables site mean of + ve pcna cases mean of + ve bax cases r pa major minor 23.625 29.3 16 28 0.368 acc major minor 45.2 34.61 37.66 17 0.258 mec major minor 80 32.5 71 51.333 0.28 adenocarcinoma major minor 23.6 57 9.3 3 0.76 acinic cell ca major minor 6.2 73 70 cx pa major minor 37.5 squamous cell ca major minor 24.3 25 20 variables no. of cases bax mrna no. of cases pcna labeling index (mean ± sd.) pa 12 ve (9) + ve (3) 22.28 ± 6.8 39 ± 12.7 acc 19 ve (9) + ve (10) 32.48 ± 19.9 41.9 ± 18.2 mec 7 ve (2) + ve (5) 57 ± 32. 6 44 ± 27.2 adenocarcinoma 5 ve (2) + ve (3) 43 ± 19. 8 18.2 acinic cell ca 2 ve – + ve(2) 6.2 cx pa 2 ve(2) + ve 37.5 ± 3.535 squamous cell ca 2 ve(1) + ve(1) 24.3 25 dropbox 14 rula 76-79.pdf simplify your life j bagh college dentistry vol. 29(1), march 2017 selected salivary pedodontics, orthodontics and preventive dentistry 125 selected salivary biomarkers in relation to work-related musculoskeletal disorders among a group of dentists in baghdad city wassan jamal obaid, b.d.s. (1) baydaa ahmed yas, b.d.s., m.sc., ph.d. (2) abstract background: work-related musculoskeletal disorders represent an important occupational health issues among dentists especially neck and low back complaints. biomarkers of tissue damage as results of occupational physical demands could be used for detection of work related musculoskeletal disorders. aim: the aim of this study was to assess workrelated musculoskeletal disorders, physical work load index, selected salivary biomarkers (creatine kinase and c reactive protein) and to find the relation among them. subjects and methods: study participants are consisted of 112 dentists. they were selected from college of dentistry /baghdad university, health care center in bagdad city. they were of both gender and aged between 40-45 years .they should fit the study criteria. self-administered standardized nordic questionnaires were used to evaluate musculoskeletal complaints. physical work load was evaluated by used physical work load index. stimulated saliva were collected from subsample (87) dentists drawn randomly from the total sample, for whom biochemical analysis (measurement of creatine kinase and c reactive protein) were done. results: results showed that low back and neck complaints is the most complaint experienced by the dentists with percentages of ( 69.6% and 66.1% ), followed by the shoulder complaint (49.1% ) while the hip complaint showed the lowest percentage (13.4%).according to severity scores ,both low back and neck musculoskeletal complaints were of score 3 severity (score 3 constituted the highest percentages in both area (27.7% ,23.2%respectively) as compared to other severity scors.for shoulder complaint it was of score 2 severity (score 2 constituted the highest percentage 23.2% as compared to other severity scores, the musculoskeletal complaints(proximal ,neck, shoulder and low back) had higher mean rank values in the highest quartile of physical work load index with non – significant differences (p<0.05). regarding salivary creatine kinase the proximal ,total and low back complaints had higher mean rank values among dentists with highest creatine kinase quartile , while distal manifestations ,neck and shoulder complaints had higher mean rank value in the average interquartile range of creatine kinase with non – significant differences( p<0.05). for creactive protein almost all the complaints(proximal , total ,neck and shoulder) had higher mean rank values in the first lowest quartile with non – significant differences( p<0.05). conclusions: physical work load increase the risk of musculoskeletal disorders occurrence. salivary creatine kinase could serve as a biomarker that reflects the underlying of musculoskeletal complaints more than c reactive protein. further studies that used more objective tools for assessing musculoskeletal disorders is needed. keywords: musculoskeletal disorder, physical work load index, creatine kinase, c reactive protein. (j bagh coll dentistry 2017; 29(1):125-131) introduction musculoskeletal disorders (msds) include a wide range of inflammatory and degenerative conditions affecting the body's joints, muscles, nerves, and tendon and structures that support limbs, neck and back (1,2). many factors are responsible for msd, like occupational factors, medical factors, physical disorders, genetic predisposition, age, life style factors and psychological factors. usually two or more factors will cause msd (3, 4). work-related musculoskeletal disorders (wmsds) refer to msds that are made worse or longer lasting by work conditions (5). in dentistry the prevalence of musculoskeletal disorder among dentists and dental hygienists was reported to be high (6). many longitudinal studies had been carried out over a period of 1 to 5 years and found that over half (60%, 72%, 81%, 65% and 78%) of the participating dentists experienced musculoskeletal pain (7, 8, 9, 10, 11). (1) master student, department of preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of preventive dentistry, college of dentistry, university of baghdad. in iraq two studies could be found in which wmsds were assessed by using selfadministrated questionnaire. al-tai found that 785 of the examined dentists reported musculoskeletal pain and 86% of them had low back pain(12). in another iraqi study recorded that 77% of the examined dentists had complaints of back and neck problem (13). early diagnosis of musculoskeletal disorder is essential for their prevention and treatment (14). the use of biomarkers in body fluid had attracted attention of many investigators (15). one of these biomarkers is creatine kinase enzyme; it is the most commonly studied intramuscular protein in relation to skeletal muscle damage induced by physical work (16, 17). only very few studies have examined serum levels of creatine kinase in relation to industrial tasks, these studies recorded an increase in serum creatine kinase levels after 4 days of industrial work and that serum creatine kinase level was significantly correlated with daily workload (18, 19, 20). the second biomarker was c reactive protein that had received attention as a marker of chronic j bagh college dentistry vol. 29(1), march 2017 selected salivary pedodontics, orthodontics and preventive dentistry 126 inflammation in musculoskeletal conditions (21). also few studies could be found regarding creactive protein level in relation to musculoskeletal complaints (22, 23). these studies revealed an association between musculoskeletal complaints and level of c –reactive protein. saliva as a diagnostic tool has attracted the attention of numerous investigators because of the noninvasive nature and relative simplicity of collection (24).however no studies could be found regarding the level of these biomarkers in saliva in relation to musculoskeletal disorders. therefor this study was carried out in order to evaluate work-related musculoskeletal disorder and physical work load. also to measure the level of creatin kinas and c reactive protein in saliva and relating them with work-related musculoskeletal disorder and physical work load among a group of dentists in baghdad city. subjects, material and methods the sample for this study was consisted of 112 dentists of both gender aged 40-45 years. they were selected from specialized dental centers, heath care centers and collage of dentistry/ baghdad university. informed consent and ethical approval was obtained for their examination. they should fulfill the selected criteria, they should be healthy and free of selfreported (anemia, diabetes, heart disease and inflammatory conditions include arthritis),non smoker ,should not been injured in the last six years, should not have bloodborne disease, should not be on excessive use(>81mg /daily) of non-steroidal anti-inflammatory drugs, should not be on lipid lowering medications, should not have heavy exercises in the last two days, prior to the study or other physical activities beyond those required to perform their normal daily activities , should be without any medical history that compromise salivary secretary mechanisms, should not take any medications with xerostomic effect, should not wear any fixed or removable dental prosthesis and pregnant and women with significant gynecological problems or those during menstruation cycle should be excluded (25). this study was carried out during the period between december 2015 and march 2016 in baghdad. each subject fills out two questionnaire format (self-administered questionnaires). the first one is standardized nordic musculoskeletal questionnaire (smsq) (26) in order to assess nature and severity of self-related musculoskeletal symptoms, the questionnaire include items regarding the experience of musculoskeletal problems in nine body areas over the past week and over the past year. the second questionnaire format is related to physical workload by hollmann et al. to find physical work load index (27). body weight status was determined by using body mass index (bmi) which can be obtained by dividing weight in kilogram by height in meter squared kg/m2, the body mass index was divided into four category included underweight<18.5, normal weight (18.5-24.9), overweight (25-29.9), and obese + 30 (28). then stimulated saliva were collected from subsample drown randomly from the total sample that was consisted of 87 dentists of both gender. saliva collection was performed according to the instruction cited by tenovuo and lagerlof (29).then biochemical analysis were performed to measure salivary creatine kinase and c reactive protein by using enzyme –linked sorbent assay (elisa). all the laboratory works were done in poisoning consultation center, gazi al-hariry hospital. statistical analyses were done by using ibmspss version 23 computer software (statistical package for social sciences) in association with microsoft excel 2016. most of the outcome (response) variables were nonnormally distributed variables. such variables can be described by median and interquartile range. statistical tests used were (mannwhitney) and kruskal-wallis test in addition to spearman’s rank linear correlation coefficient. an estimate was considered statistically significant if its p value was less than a  level of significance of 0.05. results distribution of the dentists according to gender and body mass index is shown in table (1), the total sample consist of 112 dentist females form two third of the total sample with 70.5% while males constituted 29.5%. concerning the body mass index the higher percentage of the dentists were overweight 44.6% while those who are normal and obese revealed an equal percentages (28.6%, 26.8%).while underweight was zero. results in table (2) showed that low back and the neck complaints were the most complaints experienced by the dentists with percentages of (69.6% and 66.1%) respectively, followed by the shoulder (49.1%) and upper back (27.7) while the hip complaint showed the lowest percentages (13.4%). musculoskeletal complaints severity score according to body parts is shown in table (3). results revealed that for both neck and low back j bagh college dentistry vol. 29(1), march 2017 selected salivary pedodontics, orthodontics and preventive dentistry 127 complaints, severity scores were of score 3 (symptoms in both the last 12 months and the last 7 days and, in addition, restrictions).score 3 constituted the highest percentages (23.2% and 27.7%) for neck and low back complaints respectively than other scores. also for shoulder complaint it was of score 2 severity (symptoms in the last 12 months and neither symptoms in the last 7 days or restrictions) that constitute the highest percentage (23.2%) than other scores. physical work load index was classified into three quartiles as described in table (4), results revealed that musculoskeletal complaints (proximal, neck, shoulder and low back) had higher mean rank value in the highest quartiles ,except for total and distal complaints had higher mean rank value in the average interquartile with non – significant differences (p<0.05). relation of musculoskeletal complaints with salivary creatine kinase quartiles is showed in table (5) results showed that mean rank values for musculoskeletal complaints were higher in highest quartiles regarding proximal ,total and low back complaints , while distal manifestations ,neck and shoulder complaints had higher mean rank values in the average interquartile range but with non – significant differences( p<0.05). regarding creactive protein it was classified into three quartiles as shown in table (6) results showed that almost all the musculoskeletal manifestations (proximal , total ,neck and shoulder) had higher mean rank values in the first lowest quartile but with non – significant differences ( p<0.05). table 1: distribution of the dentists according to gender and body mass index. parameter gender bmi female male total normal (<25) overweight (25-29.9) obese (30+) total no. 79 33 112 32 50 30 112 % 70.5 29.5 100.0 28.6 44.6 26.8 100.0 table 2: distribution of dentists according to presence or absence of musculoskeletal complaints by body parts. body parts musculoskeletal complaints absent present no. % no. % neck complaints score 38 33.9 74 66.1 shoulder complaints score 57 50.9 55 49.1 elbow complaints score 96 85.7 16 14.3 wrist/hands complaints score 85 75.9 27 24.1 upper back complaints score 81 72.3 31 27.7 low back complaints score 34 30.4 78 69.6 hip complaints score 97 86.6 15 13.4 knee complaints score 70 62.5 42 37.5 ankle/feet complaints score 91 81.3 21 18.7 table 3: distribution of the dentists according to musculoskeletal complaints severity score by body parts. severity scores body part score 0 (neither symptoms nor restrictions) score 1 (symptoms in the last 12 months but not in the last 7 days and no restrictions) score 2 symptoms in the last 12 months and neither symptoms in the last 7 days or restrictions) score 3 symptoms in both the last 12 months and the last 7 days and, in addition, restrictions body part no. % no. % no. % no. % neck 38 33.9 23 20.5 25 22.3 26 23.2 shoulder 57 50.9 17 15.2 26 23.2 12 10.7 elbow 96 85.7 10 8.9 3 2.7 3 2.7 wrist hand 85 75.9 14 12.5 9 8 4 3.6 upper back 81 72.3 0 0 23 20.5 8 7.1 low back 34 30.4 21 18.8 26 23.2 31 27.7 hip 97 86.6 8 7.1 6 5.4 1 0.9 knee 70 62.5 22 19.6 13 11.6 7 6.3 ankle feet 91 81.3 9 8.0 9 8.0 3 2.7 j bagh college dentistry vol. 29(1), march 2017 selected salivary pedodontics, orthodontics and preventive dentistry 128 table 4: musculoskeletal complaints according to physical work load index quartiles. physical load index quartiles musculoskeletal complaints first (lowest) quartile <= 4.2 average (interquartile range) 4.3 12.0 fourth (highest) quartile 12.1+ pvalue proximal musculoskeletal complaints score (/100) no. 28 57 27 0.95 median 26.7 26.7 33.3 mean rank 56 55.9 58.3 distal musculoskeletal complaints score (/100) no. 28 57 27 0.16 median 0 8.3 8.3 mean rank 48 61.3 55.2 total musculoskeletal complaints score (/100) no. 28 57 27 0.82 median 22.2 22.2 22.2 mean rank 53.2 57.7 57.4 musculoskeletal manifestations score for neck complaint (/100) no. 28 57 27 0.98 median 28.6 28.6 28.6 mean rank 55.8 56.3 57.5 musculoskeletal manifestations score for shoulder complaint (/100) no. 28 57 27 0.54 median 0 7.1 14.3 mean rank 51.7 56.9 60.6 musculoskeltal manifestations score for low back complaint (/100) no. 28 57 27 0.32 median 42.9 28.6 35.7 mean rank 60.8 52 61.5 table 5: musculoskeletal complaints according to salivary creatine kinase quartiles: creatine kinase quartiles musculoskeletal complaints first (lowest) quartile <= 381.1 average (interquartile range) 381.2 549.5 fourth (highest) quartile 549.6+ pvalue proximal musculoskeletal complaints score (/100) no. 22 44 21 0.45 median 20 33.3 26.7 mean rank 38.4 45.1 47.5 distal musculoskeletal complaints score (/100) no. 22 44 21 0.86 median 4.2 8.3 0 mean rank 42.1 45.3 43.4 total musculoskeletal complaints score (/100) no. 22 44 21 0.57 median 18.5 22.2 14.8 mean rank 39.1 45.4 46.2 musculoskeletal manifestations score for neck complaint (/100) no. 22 44 21 0.18 median 14.3 35.7 28.6 mean rank 35.9 47.8 44.6 musculoskeletal manifestations score for shoulder complaint (/100) no. 22 44 21 0.1 median 0 10.7 7.1 mean rank 34.9 47.7 45.9 musculoskeletal manifestations score for low back complaint (/100) no. 22 44 21 0.89 median 21.4 28.6 42.9 mean rank 43 43.4 46.2 j bagh college dentistry vol. 29(1), march 2017 selected salivary pedodontics, orthodontics and preventive dentistry 129 table 6: musculoskeletal complaints according to salivary c-rp quartiles. c reactive protein quartiles musculoskeletal complaints first (lowest) quartile <= 1.55 average (interquartile range) 1.56 2.16 fourth (highest) quartile 2.17+ pvalue proximal musculoskeletal complaints score (/100 no. 23 43 21 0.6 median 26.7 26.7 26.7 mean rank 48.5 42.2 42.7 distal musculoskeletal complaints score (/100 no. 23 43 21 0.32 median 8.3 0 8.3 mean rank 46.5 40.2 49 total musculoskeletal complaints score (/100 no. 23 43 21 0.66 median 22.2 22.2 14.8 mean rank 47.7 41.8 44.3 musculoskeletal manifestations score for neck complaint (/100) no. 23 43 21 0.65 median 28.6 28.6 28.6 mean rank 48 42.9 41.9 musculoskeletal manifestations score for shoulder complaint (/100) no. 23 43 21 0.19 median 21.4 0 0 mean rank 51.2 40.2 44 musculoskeletal manifestations score for low back complaint (/100) no. 23 43 21 0.96 median 14.3 42.9 28.6 mean rank 42.8 44.7 43.8 discussion dentistry represents an important and critical occupation since dentists are subjected to many hazards; one of the most important of these hazards is musculoskeletal disorder probably because of the nature of this occupation (30). musculoskeletal complaint were evaluated by using standardized nordic questionnaire, self – administered questionnaire was used ,this type of questionnaire is suitable for cross sectional studies, easy, clear, less time consuming and can provide an additional diagnostic tool for the analysis of work environments and work conditions (26). results of the current study revealed that highest percentages of the dentists were suffer from low back , neck and shoulder complaints their percentages were 69.6% , 66.1% and 13.4% respectively. according to severity score of musculoskeletal complaints both low back and neck complaints were of score 3 severity (symptoms in both the last 12 months and the last 7 days and, in addition, restrictions). for shoulder complaint it was of score 2 severity (symptoms in the last 12 months and neither symptoms in the last 7 days or restrictions).the same finding was also reported by other studies that showed higher prevalence rate of low back, neck and shoulder musculoskeletal complaints (31, 32, 33, 34). the possible explanation of higher low back, neck and shoulder musculoskeletal complaints among dentists is probably related to their poor posture ,repetitive movements, elevated and unsupported arm, bent and twisted back position, use of vibrating tools and prolonged sitting or standing posture (35). this is further supported by the study finding that dentists with highest physical work load quartile and those with average physical work index quartiles revealed higher musculoskeletal complaints mean rank (proximal, neck, low back and shoulder) for highest physical work load index quartile and distal and total musculoskeletal complaints for those with average physical work load index quartile. this was consistent with many studies which found a relationship between physical load and musculoskeletal complaints in dentistry (36, 37).since physical work load index is related to body posture and lifting weight, activities that need heavy loads can result in acute injury to the musculoskeletal system. this mean as the physical load increase the musculoskeletal complaints increase, therefor physical workload itself was considered as a risk factor for musculoskeletal complaints (38, 39, 40). results from several clinical and experimental studies indicate that pathological and adaptive tissue changes could occur as a results of performing repetitive and forceful tasks, these tissue changes could revealed by biomarker of inflammation like creactive protein and biomarker of cell injury like creatine kinase j bagh college dentistry vol. 29(1), march 2017 selected salivary pedodontics, orthodontics and preventive dentistry 130 (16,21,38). results of the current study showed that according to creatine kinase quartiles dentists with average (interquartile range) and those with highest creatine kinase quartiles had higher muscskeltal complaints mean rank value regarding distal, neck and shoulder for the average (interquartile range) and proximal and low back complaints for the highest quartiles although statistical differences were non – significant. regarding c-reactive protein results showed that dentists with lowest quartile had highest musculoskeletal complaints mean rank values except for distal and low back complaints however statistical differences were non – significant. this mean that creatine kinase is more related to musculoskeletal complaints than c-reactive protein probably due to the fact that creactive protein enzyme is considered a biomarker of inflammation that mean there is a state of inflammation associated with musculoskeletal disorder but muscle cell injury still not occur (39). while creatine kinase is more related to musculoskeltal complaints probably because it is a biomarker of cell injury that mean there is cell damage, muscle cell disruption, or disease. these cellular disturbances can cause ck to leak from cells into blood stream (17) and its level will increase in saliva, since saliva is considered as mirror that reflect normal internal characteristics and disease (24). the study finding goes with that of many studies (18, 19, 20). this might open the way for the possible use of salivary creatine kinase and c-reactive protein as a biomarkers of musculoskeletal disorder (15). it is important to mention that in the current study musculoskeletal complaints were evaluated by using the standardized nordic questionnaire that measure the symptoms only (subjective method),while more objective methods like clinical examination ,radiograph, magnetic resonance image (mri) etc. did not use in the current study because of technical difficulties. this might explain the non-significant differences in musculoskeletal complaints according to creatine kinase and creactive protein quartiles. there for further study that used more objective methods for measuring musculoskeletal complaints is required. references 1. kumar s. theories of musculoskeletal injury causation. ergonomics 2001; 44(1): 17-47. 2. punnett. l, and wegman dh. work-related musculoskeletal disorders: the epidemiologic evidence and the debate. journal of 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تتراوح أعمارهم بين المشاركين كانوفي مدينة بغداد. والتخصصية مؤشر حجم العمل خالل استخدامتقييم عبء العمل الجسدي من المتعلقة باالضطرابات العضلية الهيكلية و الشكاوى لتقيم التي تدار ذاتيا استخدمت االستبيانات الكيمياء بالتحاليل من اجل القيام من مجموع العينة بصورة عشوائية استخالصها تم طبيب اسنان (78) من البدني. تم جمع اللعاب المحفز من عينة فرعية .بروتين(ريكتف –رياتين كاينيز و سي ك )قياسلالحيوية (، تليها شكوى الكتف ٪66.1و ٪6..6األكثر شكوى من ذوي الخبرة من قبل أطباء األسنان مع نسبة ) ي:وأظهرت النتائج أن االلم أسفل الظهر والرقبة ه النتائج الظهر و االلم كانت كل منالظطرابات العضلية الهيكلية شدةلدرجة ال(.ووفقا ٪0..1أدنى نسبة )تمثل الورك النتائج ان شكوى الم اظهرت (، في حين 1٪..0) بالمقارنة مع شدة شكوى الكتف على التوالي( ٪1..1، ٪18.8)اسفل الظهر والرقبة تشكل أعلى النسب في كل من منطقة .درجة شدة شدة ) .درجة لهاالرقبة في العضلية الهيكاية بالبنسبة لمناطق القريبة والعنق والكتف واسفل الظهر لها قيم عليا وكانت الشكاوى . ٪1..1شكل أعلى نسبة ت 1شدة )يسجل درجة 1 ت كان ( p <4.44فروق ذات داللة إحصائية ) -الربع االعلى من مؤشر حجم العمل البدني مع غير الكرياتين كيناز ، في حين أن من علىالربع األ مظاهر القريبة و الكلية واسفل الظهر تسجل اعلى قيم في الالكرياتين كيناز اللعابي والداني، كان لموشر بالنسبة . pفروق ذات داللة إحصائية ) -مع غير كاينز الكرياتين من الرتبة في المدى المتوسط متوسط تسجل اعلى قيم في الربع الالمظاهر البعيدة والرقبة والكتف ريكاتف –تسجل اعلى قيم في الربع االسفل االدنى من سي والعنق والكتف( الكلية الشكاوى تقريبا كل )القريبة، اغلب –ريكاتف بروتين –بالنسبة لسي (. 4.44> (.p <4.44فروق ذات داللة إحصائية ) -مع غير بروتين العالمات من الكرياتين كيناز يمكن أن تكونبالنسبة اللعابية المقايس .الهيكليةية ضطرابات العضلاال حدوث : حجم العمل البدني يزيد من خطراالستنتاجات أدوات و استخدام هناك حاجة إلى إجراء المزيد من الدراسات .ريكاتف بروتين –سي أكثر من ية الهيكلية الكامنة وراء الشكاوى العضل الصورة البيولوجية التي تعكس .العضلية الهيكلية ضطراباتاالأكثر موضوعية لتقييم 3maha f.doc j bagh college dentistry vol. 28(3), september 2016 a comparative evaluation restorative dentistry 15 a comparative evaluation of apical seal associated with ultrasonic retrograde cavities filled with bioactive material (in vitro study) raghad a. al-hashimi, b.d.s., m.sc., ph.d. (1) maha a. habeeb, b.d.s., m.sc. (2) athil a. al-kinani, b.d.s., m.sc. (3) abstract background: the aim of this study was to evaluate and compare the apical microleakage around retrograde cavities prepared with ultrasonic technique and filled with (biodentine™) materials and methods: 40 extracted single rooted human permanent maxillary teeth with mature apices were selected. the roots were prepared chemo-mechanically using k-files with crown-down technique and then obturated with lateral condensation gutta-percha technique. teeth were divided into four main groups according to the cavity preparation method either manual or ultrasonic technique: group a (n=10): a class i retrograde cavity at root end was prepared with traditional handpeice equipped and placement of biodentine with manual condensation. group b (n=10): a class i retrograde cavity at root end was prepared with piezoelectric ultrasonic device equipped with ultrasonic tip with only manual compaction of the material. group c (n=10): traditional handpeice and placement of biodentine using both manual compaction and 5 second ultrasonic activation. group d (n=10): piezoelectric ultrasonic device and placement of biodentine with both manual compaction and 5 second ultrasonic compaction. the teeth were immersed in 1% aqueous methylene blue dye for 72 hr. then they were sectioned longitudinally with a diamond disc and the depth of dye penetration was examined under high magnification 20x. results: statistical analysis showed a highly significant difference in microleakage among the tested groups in which piezoelectric technique has proved superiority in retrograde cavity preparation and compaction of biodentin when dye penetration scores were compared. so microleakage was highest with cavities prepared with handpeice and manual application of retrograde material group a (2.73±0.39) followed by microprepared cavities group c (1.86±0.16), and it was lowest with ultrasonically-prepared cavities group b (1.09±0.28) and group d (0.26±0.19). conclusion: ultrasonic preparation produced significantly less microleakage than conventional method. also less microleakage was observed with ultrasonic compaction of biodentin when compared with conventional method of compaction. keywords: endodontic surgery, microleakage, biodentine, piezoelectric ultrasonic device, retrograde cavities. (j bagh coll dentistry 2016; 28(3):15-21). introduction surgical root canal therapy is an alternative treatment of apical periodontitis of endodontic origin when nonsurgical root canal treatment or retreatment fails or when nonsurgical retreatment is impossible (1). the surgical procedure is preceded by resecting an infected portion of the root apex to eradicate the periapical lesion which is the source of infection and preparing a cavity at the root end (2). a permanent root-end filling is then placed to provide an adequate apical seal that prevents passage of bacteria or their products from leaking root canal space into the periapical tissues (3). over many years ago, a numerous number of materials have been suggested for use as root-end fillings, including amalgam, gutta-percha, zinc (1)assist. professor. department of conservative dentistry, college of dentistry, university of baghdad. (2) lecturer. department of conservative dentistry, college of dentistry, university of baghdad. (3) oral and maxillofacial surgeon. ministry of health, iraq. oxide eugenol cements, composite resins, glass ionomer, polycarboxylate cements, ethoxybenzoic acid (eba) cement, and mineral trioxide aggregate (mta). the main prerequisites of ideal root end filling material are as follows: biocompatibility, promotion of tissue regeneration without causing inflammation, ease of handling, low solubility in tissue fluids, bonding to dental tissue, nonabsorbable, dimensional stability, radio-opacity and no staining of surrounding tissues (4). recently, a new bioactive retrofilling material namely biodentinetm (septodont, france) has been developed as dentine replacement material with the aim of improving the clinical use and overcoming mta limitations. it is primarily composed of tricalcium silicate, whereas zirconium oxide is added as a radiopacifier. biodentine powder also contains calcium carbonate, while the liquid consists of calcium chloride, and a hydrosoluble polymer. it has been reported that biodentine shows a reduced time setting with promising physical and biological j bagh college dentistry vol. 28(3), september 2016 a comparative evaluation restorative dentistry 16 properties as a dentine restorative material and was recently suggested as a pulp-capping material. besides that, biodentine has the potential to release calcium hydroxide when it comes in contact with physical tissue fluid enhancing the sealing ability of the material itself (5). the traditional technique used to cut the root apex was usually performed with using a lowspeed turbine and round bur. however, the application of piezo electric ultrasonic for root end preparations showed promising results in terms of optimal cleaning of apical tissue debris and minimally invasive technique with high efficiency. piezoelectric device contains a crystal, when an electrical charge is applied, this crystal undergoes deformation that is converted into mechanical oscillation without producing heat (6, 7). there are limited studies on using ultrasonic technique for root end cavity preparation and their effects on marginal adaptation of new calcium based cement material, biodentine (septodont, france). the null hypothesis was tested in the current study is that the sealing ability of biodentine on ultrasonic root end cavities is not comparable to that one prepared with traditional bur technique. this in vitro study aimed to assess and compare the sealing ability of calcium silicate based materials filled retrograde cavities prepared with two techniques of traditional bur and ultrasonic. materials and methods teeth selection forty human freshly extracted human singlerooted teeth with mature apices and straight roots were selected and teeth selection from patients aged (18-45) years. the apical 3rd of each root was examined to make sure it is free from any fracture, calcifications, resorption or cracks (8). teeth were cleaned with ultrasonics and stored in distilled water at room temperature (fig. 1). fig. 1: the selected teeth preparation of specimens crowns were sectioned above the cementoenamel junction to standardize the working length of the specimens of about 16 mm. the access cavities were prepared using endo round access bur #2 (dentsply, maillefer), the root canal patency was confirmed by passing a 10-k file (maillefer, ballaigues, switzerland), the irrigant solution was 20 ml of 0.5% naocl for each tooth. after being cleaned and shaped, canals were dried with paper points, working length was determined. barbed broaches were used for pulp extirpation. then root canals were prepared with hand kfiles together with irrigation with 5 ml of freshly prepared 5.25% sodium hypochlorite (naocl) solution and rinsed with 3 ml of 17% ethylenediaminetetraacetic acid (edta) for 5 min to remove the smear layer using crown down technique, enlarging up to apical size #60 instrument and paper points were used for dryness and master cone was placed, the selected cone was fitted to ensure a snug fit apically. lateral condensation obturation method, using finger spreaders was carried out for filling root canals (9). the apical 3mm of each root was removed using high speed handpiece (w&h, austria) and a diamond parallel sided fissure bur (komet dental, austria) perpendicular to the long axis of the root under water and air spray to ensure standardization and facilitate root end cavity preparation (10). retrograde cavity preparation a round root end cavity was prepared with 3mm depth in which its shape and dimensions are standardized according to the shape of bur which was used in our study (carbide round bur #2, komet dental, austria) (7). for ultrasonicly prepared cavities, a surgical round retro tip (surgysonic i, es03a) with 2mm head was used for standardization of cavity. 3mm depth is considered the minimum depth of retrograde filling to establish good seal. sample grouping: a total of 40 teeth were randomly divided into four main groups (n = 10 each) according to method of root end cavity preparation either with bur or piezoelectric ultrasonic device (esacrom, italy) equipped with ultrasonic retro tip, fig2: group a (10 teeth): a class i round retro cavity at root end with 3mm depth was prepared with rightangled low speed handpiece (w&h, austria) equipped with carbide round bur #2 (komet dental, austria) and biodentine, fig(2) j bagh college dentistry vol. 28(3), september 2016 a comparative evaluation restorative dentistry 17 (septodont, france) was placed inside retro cavity manually using small hand condenser. group b (10 teeth): a class i round retro cavity at root end with 3mm depth was prepared using piezoelectric ultrasonic device (esacrom, italy), fig(3) equipped with diamond coated stainless steel ultrasonic surgical retro tip , fig(4) (surgysonic i, es03a) at (30-khz) frequency and biodentine (septodont, france) was placed inside retro cavity manually using small condenser. group c (10 teeth): a class i round retro cavity at root end with 3mm depth was prepared with rightangled low speed handpiece (w&h, austria) equipped with carbide round bur round bur #2 (komet dental, austria) and biodentine (septodont, france) was placed inside retro cavity using both manual compaction and 5 second ultrasonic activation using ultrasonic condenser tip, fig (5) (surgysonic i, es08a). group d (10 teeth): a class i round retro cavity at root end with 3mm depth was prepared using piezoelectric ultrasonic device (esacrom, italy) equipped with diamond coated stainless steel ultrasonic surgical retro tip (surgysonic i, es03a) at (30-khz) frequency and biodentine (septodont, france) was placed inside retro cavity with both manual compaction and 5 second ultrasonic compaction using ultrasonic condenser tip (surgysonic i, es08a). microleakage study immediately after application of retrograde filling and setting of biodentine which required 12 min., all the specimens were coated with two coats of nail varnish except for the apical 3mm and were allowed to dry for 24hrs. after dryness, the teeth were suspended so that only 2-3mm of the root was immersed in 1% aqueous methylene blue dye in an incubator at 37oc for 72 hr. (11). then roots were washed and sectioned longitudinally with a diamond disc using a water coolant. the depth of dye penetration was examined under a stereomicroscope with magnification of 20x using a calibrated scale within the lens of optical microscope to evaluate the roots for leakage. the greatest depth of dye penetration along one of the cavity walls was taken. the depth of dye penetration was measured in millimeters (12). statistical analysis mean and standard deviation were estimated from the sample for each study groups. mean values were compared by one-way anova / lsd test. spss statistical software version 18 (ibm. spss inc.usa) was employed to analyze the tested groups. results dye penetration method was used to compare sealing ability of material (biodentin). table 1 summarizes the mean values, standard deviation, standard error, minimum and maximum values for all groups: fig. 2: biodentine (septodont, france) capsule fig. 4: ultrasonic surgical retro tips (surgysonic i) fig. 3: piezoelectric ultrasonic device fig. 5: ultrasonic condenser tip es08a j bagh college dentistry vol. 28(3), september 2016 a comparative evaluation restorative dentistry 18 table 1: descriptive statistics of microleakage of retrograde cavities in (mm) groups n mean s.d. s.e. min. max. a 10 2.37 0.39 0.12 1.8 3 b 10 1.09 0.28 0.09 0.7 1.4 c 10 1.86 0.16 0.05 1.5 2 d 10 0.26 0.19 0.06 0 0.5 figure 6: mean values of apical microleakage in (mm) of the tested groups all techniques used for root end preparation had shown a degree of microleakage. the overall comparison of the mean gap at the dentin retrograde filling material inter-face values of the four tested groups has shown that ultrasonicallyprepared cavities had less microleakage than micro prepared cavities, so microleakage was highest with apical cavities prepared with handpeice and manual application of retrograde material group a (2.73±0.39) followed by microprepared cavities but with both manual and ultrasonic compaction of (biodentin) group c (1.86±0.16), and it was lowest with ultrasonicallyprepared cavities with or without ultrasonic compaction group b (1.09±0.28) and group d (0.26±0.19). in order to identify the presence of statistical significant difference among groups, one way anova test was carried on. table 2: one way anova test to show the statistical difference of dye penetration between groups .highly significant at level p<0.001 ٭ the revealed anova results had shown highly significant influence (p< 0.001) of method of apical cavity preparation and compaction method of retrograde filling on the amount of microleakage or dye penetration. because a significant difference was found, least significant difference (lsd) test was done to analyze the data to show the difference in microleakage between different groups (table 3). table 3: lsd test to compare the microleakage between each pair of tested groups .highly significant at level p<0.001٭ anova sum of squares d.f. mean square f-test p-value between groups 25.481 3 8.494 115.038 0.000 (hs) ٭ within groups 2.658 36 0.074 total 28.139 39 groups mean difference p-value a b 1.28 0.000 (hs)٭ c 0.51 0.002 (hs)٭ d 2.11 0.000 (hs)٭ b c -0.77 0.000 (hs)٭ d 0.83 0.000 (hs)٭ c d 1.60 0.000 (hs)٭ j bagh college dentistry vol. 28(3), september 2016 a comparative evaluation restorative dentistry 19 these investigations had shown that there was a highly significant difference (p<0.001) between each pair of tested groups when dye penetration values were compared. discussion microleakage has been defined as the passage of bacteria, ions, molecules, fluids or chemical substances between the root structure and the applied restorative material and is one of the major factors influencing the longevity of the dental restoration and it has been reported to cause failure of endodontic treatment (13, 14). surgical approach is commonly indicated in situations such as persistence of periapical pathology, overfilled canals, ledges, canal obstructions, separated instruments, apical transportations and perforations. the goals of periradicular surgery are to gain access to the affected area by root end resection, followed by insertion of a root end filling material which aims to create a biocompatible seal that stimulates regeneration of the periodontium. it is an important conservative treatment and an extension of endodontic therapy whose purpose is to preserve the tooth (15). several techniques have been used for assessment of apical seal, however, dye penetration techniques still remain one of the commonest methods to test sealing ability of restorative materials which is simple and safe (methylene blue, fuchsin, rhodamine b, fluorescent dyes) . these materials are able to prevent the leakage of small molecules (tracer solutions) equals 1.2nm² which equals 120 aº², this particle size is less than that of the bacterial one (16). one of the pre-requisites for the success of surgical endodontics relies on selection of root end filing material. in recent years many materials have been used for root-end fillings in endodontic surgery. biodentine has received crescent interest as a retrograde material with promising results in which it is a new material based on calcium silicate technology and water chemistry. the powder contains dicalcium silicate, tricalcium silicate, calcium carbonate, iron oxide, and zirconium oxide filler. liquid consists of calcium chloride which is acting as accelerator and a polymer which is acting as a water reducing agent (5). pawar et al (17) successfully treated a large periapical lesion using biodentine as retrofilled material in their 18 months follow-up case study. when biodentine comes in contact with dentine it leads to the formation of tag-like structures alongside an interfacial layer called the “mineral infiltration zone,” where the alkaline caustic effect of calcium silicate cements hydration products degrades the collagenous component of interfacial dentine. han and okiji et al (18) showed that calcium and silicon ion uptake into dentin leading the formation of tag-like structures in biodentine. an interesting feature of biodentine is the product packaging in a new pre-dosed capsule formulation for use in a mixing device largely improve the physical properties and better handling including sealing ability of the material also the modified powder composition and the addition of setting accelerators and softeners has an advantage of fast setting time (12 min) thereby sealing the interface earlier to avoid further leakage to take place so there is a lower risk of bacterial contamination (8). the development of ultrasonic retrotips has revolutionized root end therapy, improving the surgical procedure with better access to the root end (19). piezoelectric units have some advantages compared with earlier magnetostrictive units because they offer more cycles per second, 40 versus 24 khz. the tips of these units work in a linear, “piston-like” motion, which is ideal for surgical endodontics when creating a preparation for a retrograde filling. also it produces less heat when compared to magnetostrictive unit. the introduction of the ultrasonic tips has many advantages over the conventional bur preparation. the cavities prepared are conservative and precise because the cavity will be along the long axis of the root thus causing minimal destruction to the morphology of the canal also lessens the risk of lateral perforation. furthermore, the geometry of the retrotip design does not require a beveled root-end resection for surgical access, thus decreasing the number of exposed dentinal tubules and minimizing apical leakage while cavities prepared with the conventional slow speed handpiece result in more exposure of dentinal tubules and formation of considerable amount of debris and smear layer which are permeable to fluids and toxins thus preventing the intimate contact of the material to the cavity walls (6). this may be the reason for less microleakage observed in our study with cavities prepared with ultrasonic retrotips when we compared it with those prepared with conventional bur. this result is also accordance to study by harikaran et al (12) who explained the result to the different surface irregularities produced by the two methods in which surfaces prepared with carbide burs are known to be less rough than those prepared with diamond-coated ultrasonic tips. a rougher and j bagh college dentistry vol. 28(3), september 2016 a comparative evaluation restorative dentistry 20 hence more irregular surface offers a greater contact surface area, improving the retention and stability of the filling material reducing the risk of interface gaps and the resulting microleakage. pragna et al (20) found no significant difference between ultrasonic and conventional method, while results by salwan et al (16) disagrees with our study wherein they found better performance of slow speed handpeice compared to ultrasonics and attributed that result to the assumption of possible microfractures, cracks and surface changes of the cavity walls after ultrasonic preparation which were seen by many authors to be significantly more than those seen in cavities prepared by burs (21,22). the retrofilling materials are inserted into the retrograde cavity aiming to provide apical sealing and to prevent microorganism penetration, decreasing the leakage of irritating agents in the material/canal’s wall interface and contributing to periapical repair and preventing surgical treatment failure (5). condenser tip ultrasonically activated can be utilized for placement of retrograde filling materials. the results of our study demonstrated that the use of ultrasound for biodentin compaction inside retrograde cavity resulted in significantly less microleakage when compared with manual compaction. this is in agreement with roberta et al (23) in which they attributed it to the assumption that the ultrasonic vibration made a higher performance of the condenser during the compaction procedure because it helped in better distribution and density of the material inside the retrograde cavity improving the flow, settling and compaction of the material to root end dentinal walls with fewer voids. according to the results of this study, the null hypothesis rejected as biodentine placed on ultrasonic root end cavities is comparable to that one prepared by traditional bur technique. within the limitations of this study, the following conclusions were drawn: 1. statistically highly significant differences were found comparing the results of ultrasonic retrotip preparation versus conventional bur preparation in which ultrasonics produced significantly less leakage and better seal. 2. ultrasonic compaction of biodentine was superior to manual compaction in terms of microleakage and apical seal, in the overall comparisons. references 1marcia c, carlos h, alessandra s, eduardo r. in vitro evaluation of apical microleakage using different rootend filling materials. j appl oral sci 2006; 14(1): 4952. 2martin r, monticelli f, brackett w, loushine r, rockman r, ferrari m. sealing properties of mineral trioxide aggregate orthograde apical plugs and root fillings in an in vitro apexification model. j endod 2007; 33(3): 272-5. 3gutmann j, pitt f. management of the resected root end: a clinical review. int endod j 1993; 26: 273– 83. 4torabinejad m, watson t, pitt f. sealing ability of a mineral trioxide aggregate when used as a root end filling material. j endod 1993; 19(12): 591-5. 5elka r, tsonko u, dimitar k. microleakage associated with retrofilling after root-end resection (in vitro study). j imab 2014; 20(3): 578-83. 6gianluca p, cornelis h, pameijer, nicola m, francesco s. ultrasonics in endodontics: a review of the literature. joe 2007; 33(2): 81-93. 7harican j, kavitha d, narayanan l. sem evaluation of two different root-end preparations and a comparative microleakage evaluation of three different retrofilling materials using two different root-end preparations by dye penetration methodan in vitrostudy. j ind aca dent spec 2010; 1(3):1-6. 8ravichandra p, harikumar v, deepthi k, jayaprada r, ramkiran d, jaya n, krishna m, gita m. comparative evaluation of marginal adaptation of biodentinetm and other commonly used root end filling materials-an in vitro study. j clinical and diagnostic res 2014; 8(3): 243-5. 9kokate s, pawar a. an in vitro comparative stereomicroscopic evaluation of marginal seal between mta, glassionomer cement & biodentine as root end filling materials using 1% methylene blue as tracer. endod 2012; 24(2): 36-42. 10xavier c, weismann r, deoliveira m, demarco f, pozza d. root-end filling materials: apical microleakage and marginal adaptation. j endod 2005; 31(7): 539-542. 11caron g, azerad j, faure mo, machtou p, boucher y. use a new retrograde filling material (biodentine) for endodontic surgery: two case reports. int j oral sci 2014; 6(4): 250-3. 12harikaran, kavitha, narayanan l. sem evaluation of two different root-end preparations and a comparative microleakage evaluation of three different retrofilling materials using two different root-end preparations by dye penetration method an in vitro study. jiads 2010; 1(3). 13ayush r, arun v, k dixit. comparison of microleakage of root-end filling materials an in vitro study. endodontol 2011; 45(3): 22-9. 14cristina b, ruben w, marı´lia g, fla´vio f, daniel h. root-end filling materials: apical microleakage and marginal adaptation. joe 2005; 31(7). 15saeed r, shahriar s, mehrdad l, hamid r. comparision of microleakage with three different thickness of mineral trioxide aggregate as root-end filling material. j oral sci 2008; 50(3): 273-7. 16salwan y, mohammed sa, alaubaydi af. comparison of microleakage in three different retrograde cavity preparations with mineral trioxide aggregate as filling material. j bagh college dentistry 2010; 22(3): 34-8. 17pawar a, kokate s, shahr a. management of a large periapicallesion using biodentine (™) as retro-grade j bagh college dentistry vol. 28(3), september 2016 a comparative evaluation restorative dentistry 21 restoration with eighteen months evident follow-up. j conserv dent 2013; 16(6): 573-5. 18han l, okiji t. uptake of calcium and silicon released from calcium silicate-based endodontic materials into root canal dentine. int endod j 2011; 44:1081-7. 19juan-i, victoria o, manuel v. influence of cavity preparation technique (rotary vs. ultrasonic) on microleakage and marginal fit of six end-root filling materials med oral patol oral cir bucal 2011; 16(2):e185-9. 20pragna m, nagesh b, jayaprakash t. microleakage evaluation around retrograde filling materials prepared using conventional and ultrasonic techniques. j clinical and diagnostic res 2015; 9(2): 43-6. 21ballex h, al-nazhan s. scanning electron microscope evaluation of the cut root surface and root end preparation using various techniques. saudi dent j 1997; 9(2): 78-82. 22calzonetti k, iwanowski t, komorowski r, friedman s. ultrasonic root-end cavity preparation assessed by an in situ impression technique. oral surg oral med oral pathol oral radiol endod 1998; 85: 210-5. 23roberta a, arruda, rodrigo s, cunha, kenner b. miguita and carlos e. sealing ability of mineral trioxide aggregate (mta) combined with distilled water, chlorhexidine, and doxycycline. j oral sci 2012; 54(3): 233-9. dropbox 9 shiamaa 47-50 .pdf simplify your life zainab f.doc j bagh college dentistry vol. 25(2), june 2013 antimicrobial activity basic sciences 185 antimicrobial activity of different types of mouthwashes against streptococcus mutans, staphylococcus aureus and candida albicans (in vitro study) zainab a. aldhaher, b.sc., m.sc. (1) abstarct background: recently increasing number of people are using mouthwashes for general and oral care while the primary appeal of a mouthwash is an aid to breath freshness and cleansing the mouth, the majority of mouthwashes also claim to have antiseptic properties. the aim of this study is to determine the antimicrobial effectiveness of eight types of mouthwashes against streptococcus mutans, staphylococcus aureus and candida albicans in vitro. materials and methods: agar diffusion technique was used to evaluate the antimicrobial activity of eight types of mouthwashes against streptococcus mutans, staphylococcus aureus and candida albicans isolated from the oral cavities of patients attending dental clinics at college of dentistry baghdad university. results: al-mansour mouthwash emerged as the most effective mouthwash giving the maximum mean diameter of inhibition zones against staphylococcus aureus (26 mm), candida albicans (25 mm) and streptococcus mutans (20 mm) followed by corsodyl mouthwash, emoform mouthwash and zac mouthwash all of them had excellent levels of antimicrobial activity also breath, close up, sensodyne and aquafresh had good antimicrobial activity conclusion: all the mouthwashes used revealed antimicrobial activity against the three microorganisms used even when these mouthwashes were diluted but the concentrated mouthwash had the strongest antimicrobial activity. al-mansour mouthwash an iraqi mouthwash was the best one according to the results of this study. key words: mouthwash, antimicrobial activity, streptococcus mutans, staphylococcus aureus, candida albicans. (j bagh coll dentistry 2013; 25(2):185-191). introduction many bacterial species have been identified from the human mouth. these microorganisms are easily grown and produce dental plaque in the mouth environment, due to the constant influx of nutrients through; saliva, food intake, warm temperatures and moisture. (1) plaque associated oral disease affects a considerable portion of the population and is considered one of the major causes of tooth loss. in most cases, the chronic accumulation of dental plaque often leads to caries and periodontal disease (in genetically susceptible individuals), that may not only affect the patient’s oral health, but may also contribute to a number of chronic systemic diseases (2). despite great improvements in the global oral health status, dental caries still remains one of the most prevalent diseases (3).the early stage of dental caries is characterized by a destruction of superficial dental structures caused by acids which are by-products of carbohydrate metabolism by streptococcus mutans, a cariogenic bacterium. colonization of teeth by cariogenic bacteria is one of the most important risk factors in the development of dental diseases (4). streptococcus mutans and candida albicans are the two microbes often implicated in oral diseases, candida albicans is the most common yeast isolated from the oral cavity and a common cause of oral thrush, endocarditis, septicemia, vaginitis and infection of skin, nails and lungs (5). (1)lecturer. department of basic sciences. college of dentistry. university of baghdad. it is by far the fungal species most commonly isolated from infected root canals, showing resistance to intercanal medication (6). staphylococcus aureus is a major human pathogen, responsible for a number of hospitalacquired infections, initially colonizes several locations in the human body, but the mouth and hands are the main reservoirs for propagation of this pathogen in the hospital environment (7). recent studies demonstrate that staphylococcus aureus is isolated from pre-implant lesions and from the site of surgical implants (8), hence eradication of these microorganisms is important for dental treatment. prevention of oral diseases is easier than a cure. the widespread use of mouthwashes as an aid to oral hygiene is a relatively recent phenomenon in the developing countries of the world (9). the mechanical removal of plaque through frequent and efficacious brushing and flossing is the principal means of preventing periodontal diseases and diminishing the risk of caries however, some individuals lack the dexterity, skill or motivation for mechanical plaque removal. mouth-rinsing is easier to perform and may aid in controlling supragingival plaque and gingivitis, but it should always be used in conjunction with mechanical hygiene. (10) several studies focusing on the efficacy of mouthwashes with diverse chemical composition demonstrated that these mouthwashes are able to j bagh college dentistry vol. 25(2), june 2013 antimicrobial activity basic sciences 186 diminish the metabolic activity of microorganisms present in the oral cavity (11). the aim of this study was to determine the antimicrobial properties of eight commonly available mouthwashes against three oral pathogens related to caries and to oral infections materials and methods thirty patients attending dental clinics at college of dentistry baghdad university with various oral infections such as dental caries, periodontal diseases, thrush, oral abscesses and oral lesions associated with artificial denture were included in this study and samples were taken from these patients to obtain streptococcus mutans, staphylococcus aureus and candida albicans • streptococcus mutans isolation: stimulated saliva samples were collected under standard condition from patients with dental caries. the collected saliva was homogenized by vortex mixer for two minutes. ten-fold serial dilutions were prepared using sterile normal saline. two dilutions were selected for each microbial type and inoculated on mitissalivarius bacitracin agar (msb agar), a selective media for streptococcus mutans: 0.1ml was withdrawn from dilutions 10-2 and 10-3 using adjustable micropipette with disposable tips and then spread in duplicate by using sterile microbiological glass spreader on the plates of msb agar, the plates were then incubated anaerobically by using a gas pack supplied in an anaerobic jar for 48 hours at 37°c followed by aerobic incubation for 24hours at 37°c(12,13). • staphylococcus aureus were isolated from oral cavity of patients with oral abscesses, periodontal disease, gingivitis or other related oral infections. swab samples taken from abscesses and gum of these patients were first inoculated in nutrient broth for 18 hours at 37°c then the broth was cultured on mannitol salt agar which is a selective medium with 7-9% nacl and phenol red as ph indicator.(14) • candida albicans were isolated from patients with denture swab has been taken from the palatal mucosa of the patient and the dorsal surface of the tongue then swab had been cultured on sabaraud dextrose (sd) agar and incubated at 37°c for 72 hours. a selective media for cultivation and isolation of candida albicans. • identification: a) colony morphology: the colony on msb agar, mannitol salt agar and sd agar were examined directly under dissecting microscope (magnification ×15). b) morphology of the microbial cells: a colony was picked up from msb agar, mannitol salt agar and sd agar plates separately under sterilized conditions and subjected to gram`s stain. c) biochemical tests: bacterial colonies of different morphology were picked up from msb agar, mannitol salt agar separately under sterilized conditions using inoculating loop and then inoculated in 10 ml of sterilized brain heart infusion agar and incubated aerobically at 37°c for 18 hrs. the following tests were conducted: 1. catalase production test on both type of streptococcus mutans and staphylococcus aureus separately. 2. coagulase this test was conducted on staphylococcus aureus d) identification system of api (analytical profile index) strep: api 20 strep was a standardized system used in the identification of s. mutans.api staphwas used in the identification of staphylococcus aureus, api – yeast-ident candida system was used for the identification of candida albicans the tests done in these api need inoculation with a dense suspension of organisms from a pure culture v mouthwashes collection eight mouthwashes products (table 1) from baghdad (iraq) pharmacies were used in this study j bagh college dentistry vol. 25(2), june 2013 antimicrobial activity basic sciences 187 table 1: types, compositions and manufacturer of the mouthwashes used in this study name composition manufacture breath rx sorbitol, propylene glycol, xylitol, zinc glyconate, aroma (mint, thymol, eucalyptus oil) , sodium saccharin, cetylpyridinum chloride united state of america sensodyne pro enamel sodium fluoride (450 ppmf) germany close up sodium benzoate, xylitol , glycerine, flavor, sodium saccharin, cetylpyridinum chloride, zinc glyconate, citric acid, calcium lactate united kingdom corsodyl chlorhexidine gluconate 0.2% united kingdom aquafresh sodium fluoride 0.5%, cetylpyridinum chloride 0.05% united kingdom emoform-f water-propyleneglyclo, glycerin, potassium nitrate 5%, sls sodium chloride 4%, levomentholum, menthoe pip, gneolum, anetholum, sodium fluoride (1400 ppm f), potassium sulfate 0.25%, disodium phosphate, sodium sulfate, sodium saccharin egypt zac chlorhexidine gluconate 0.12%, sodium fluoride 0.05% syria al-mansour chlorhexidine gluconate 0.2% iraq screening for antimicrobial activity antimicrobial activity or effectiveness of the eight mouthwashes was assessed by using agar diffusion technique. the mouthwashes were tested at 6 concentrations 1:1, 1:2, 1:4, 1:8, 1:10 and full strength (100%) taking sterile distilled water as the diluent. staphylococcus aureus, streptococcus mutans cultures of 18 hours at 37°c in brain heart broth and candida albicans culture of 18 hours at 37°c in sabaraud broth were used. the cultures were adjusted to approximately 105 cfu/ml with sterile saline solution then each one of the three inoculum was inoculated on brain heart in fusion agar separately and plugs were removed from each agar plate producing holes. to each hole 100 µl of each concentration of mouthwash was added directly on the inoculated media agar plates for each test organisms. the plates were allowed to stand for 10 minutes for diffusion of the mouthwash to take place and incubated at 37°cfor 24 hours. the antimicrobial activity is indicated by an inhibition zone surrounding the holes containing the mouthwash. the experiments were performed in triplicates (8 isolates were used for each test microorganisms) and the mean values of inhibition zones were calculated. results 1. identification of streptococcus mutans, staphylococcus aureus and candida albicans was carried out by: a) colony morphology. (1) on the selective msb agar plates, streptococcus mutans colonies appeared light blue in color about 1-2mm in diameter as spherical or ovoid in shape with raised or convex surface. (2) on mannitol salt agar plates staphylococcus aureus colonies appeared small and surrounded by a yellow zone. (3) colonies of candida albicans appeared smooth, creamy in color with a yeast odor and typically medium sized 1.5-2mm diameter which later develop into high convex, off-white larger colonies after 2 days. b) morphological test of bacterial cells. (1) streptococcus mutans cells were gram positive, spherical or ovoid in shape, arranged in short or medium length non spore forming chains. (2) staphylococcus aureus cells were gram positive cocci arranged in clusters. (3) candida albicans under light microscope are rounded or oval yeast cells which stained gram positive. c) biochemical test: all colonies of streptococcus mutans were catalase negative all colonies of staphylococcus aureus were catalase positive, coagulase positive. d) identification system of api strep: the reaction read according to the reading table and the identification was obtained by referring to the analytical profile index. the antimicrobial activity of the mouthwashes were evaluated against streptococcus mutans, staphylococcus aureus and candida albicans and the results were recorded as the mean diameter of inhibition zones and this was summarized in the following tables: as shown in table (2) all the mouthwashes used inhibit the growth of streptococcus mutans at all the concentration used but the concentrated mouthwash (full strength without dilution 100%) give the highest inhibition zones and the diameter of inhibition zones decreased slightly in all the j bagh college dentistry vol. 25(2), june 2013 antimicrobial activity basic sciences 188 mouthwashes were moving from 100% (full strength) to 1:10. statistical analysis using t-test demonstrated that there are significant differences when the effect of each one of the concentration used was compared separately to the effect of the full strength 100% and this was for all the mouthwashes. table 2: effect of various mouthwashes on the growth of streptococcus mutans mouthwashes mean diameter of inhibition zone (mm) of different concentrations of mouthwashes 100% 1:1 1:2 1:4 1:8 1:10 breath rx 15 13* 12* 11* 10** 9** sensodyne proenamel 17 15* 15* 13* 10** 8** close up 10 8.5* 8* 7* 0** 0** corsodyl 18 15* 14* 12** 9** 9** aquafresh 11 9* 9* 8* 0** 0** emoform-f 17 15* 15* 12.5** 10** 9** zac 16 14* 12.5* 10** 8** 7** al-mansour 20 17* 16* 14.5** 12** 10** *: significant at p<0.05, ** : highly significant at p<0.01 table 3 revealed that all the mouthwashes used have antimicrobial activities against staphylococcus aureus at all the concentrations used but the concentrated mouthwashes (without any dilution 100%) give the highest inhibition zone. statistical analysis using t-test demonstrated that there are significant differences when every concentration (dilution) is compared separately with the concentrated mouthwash (100%) table 3: effect of various mouthwashes on the growth of staphylococcus aureus mouthwashes mean diameter of inhibition zone (mm) of different concentrations of mouthwashes 100% 1:1 1:2 1:4 1:8 1:10 breath rx 16 14* 13* 13* 12* 10.5** sensodyne proenamel 13 11* 10* 9* 8** 8** close up 15 13* 12* 12* 11* 10** corsodyl 26 23* 22* 20** 18** 16** aquafresh 12 9.5* 9.5* 8* 0** 0** emoform-f 24 21* 20* 15** 12** 11** zac 23 21* 20* 17** 15** 14** al-mansour 26 24* 22* 20** 17** 16** *: significant at p<0.05, ** : highly significant at p<0.01 as shown in table 4, all the mouthwash used have anti-fungal activities against candida albicans in all the concentration (dilution) used and the diameter of inhibition zones decreased when these mouthwashes were diluted with distilled water. statistical analysis using t-test demonstrated that significant differences are shown when every one of the concentration (dilution) used is compared separately with 100% full strength. table 4: effect of various mouthwashes on the growth of candida albicans mouthwashes mean diameter of inhibition zone (mm) of different concentrations of mouthwashes 100% 1:1 1:2 1:4 1:8 1:10 breath rx 13.5 11.5* 10* 9* 8.5** 8** sensodyne proenamel 12.5 11* 11* 10* 9.5* 8* close up 15 11.5* 11.5* 9.5** 8** 7** corsodyl 20 17* 15** 12** 10** 9** aquafresh 12 10* 10* 9.5* 9* 8* emoform-f 19 16.5* 15* 14** 10** 8** zac 16 13* 13* 11** 9** 8** al-mansour 25 22* 20.5** 18** 15** 13** *: significant at p<0.05, ** : highly significant at p<0.01 j bagh college dentistry vol. 25(2), june 2013 antimicrobial activity basic sciences 189 figure 1: mean diameter of zones of microbial inhibition exhibited by eight mouthwashes after 24hours at full strength (100%concentration) against three microorganisms figure 1 illustrated the antimicrobial activity of eight mouthwashes (100 %) without dilution against streptococcus mutans, staphylococcus aureus and candida albicans and it is clear that all the mouthwashes used in this study have antimicrobial activity against the three selected organisms with wide variation and al-mansour mouthwash was the most effective giving the maximum inhibition zones against the three studied microorganisms followed by corsodyl, emoform, zac, breath, close up, sensodyne and aquafresh. results were analyzed by using spss 15 statistical package (spss ltd working uk).t-test showed differences between the concentrations when each concentration is compared with concentrated mouthwash 100%. discussion the results of this study revealed that all the mouthwashes used give antimicrobial activities against the three tested microorganisms with wide variation in their effectiveness, and these results also demonstrate that the concentrated mouthwashes (100%) full strength gives the strongest antimicrobial activities and when the mouthwashes are diluted they don’t lost their antimicrobial activities but their effects decrease with dilution. several studies have demonstrated the effectiveness of rinsing with an antimicrobial mouth rinse in significantly reducing both salivary and mucosal levels of bacteria (15). the result of present study shown that al-mansour mouthwash was the best one or the most effective one against the three microorganisms tested based on the mean diameter of the zone of microbial inhibition produced by the mouthwashes in agar diffusion technique followed by corsodyl, emofarmand zac all of which showed excellent level of antimicrobial activities following by breath, close up, sensodyne and aquafresh that exhibit good antimicrobial activities. three of the four mouthwashes that exhibit excellent antimicrobial activities have chlorhexidine gluconate as the active ingredient. chlorhexidine gluconate is a cationic biguanide with broad spectrum antimicrobial action, whose effectiveness in decreasing the formation of dental plaque and gingivitis has been demonstrated in several clinical studies (16). its mechanisms of action are that the cationic molecule binds to the negatively-charged cell walls of the microbes, destabilising their osmotic balance. its substantivity, the ability of an agent to be retained in particular surroundings, is due to its ability to bind to the carboxyl groups of the mucin that covers the oral mucus and be steadily released from these areas in an active form, displaced by the calcium ions segregated by the salivary glands. chlorhexidine formulations are considered to be the “gold standard” antiplaque mouth rinses due to their prolonged broad spectrum antimicrobial activity and plaque inhibitory potential (17). emofarm is the only one from the four mouthwashes that give excellent antimicrobial activity that didn’t have chlorhexidine but it has sodium fluoride on its composition as the active ingredient. fluoride mouthwashes have been used for many years to prevent caries by promoting remineralisation with fluorapatite and fluoroj bagh college dentistry vol. 25(2), june 2013 antimicrobial activity basic sciences 190 hydroxyapatite, thereby increasing enamel resistance to acid attack (18). fluoride is available in different concentrations as either acidulated phosphate fluoride or sodium fluoride. fluoride mouthwashes reduce dental caries and they are recommended for patients at high risk of dental caries including those with xerostomia after irradiation and chemotherapy, those who have difficulty with oral hygiene procedures and those undergoing fixed orthodontic treatment. it’s a well-known fact that fluoride rinses will product the permanent dentition against caries. many antibacterial rinses now contain fluoride (19). breath mouthwash contains essential oil like eucalyptus oil, thymol and mint mouthwashes containing essential oils (thymol, eucalyptol, menthol) claim to penetrate the plaque biofilm and thus kill micro-organisms that cause gingivitis also these mouthwashes display broad spectrum antimicrobial activity, prevent bacterial aggregation, slow bacterial multiplication, retard plaque maturation and decrease plaque mass and pathogenicity. their mechanism of action is thought to involve bacterial cell destruction, bacterial enzyme inhibition. they also have antiinflammatory and prostaglandin synthetase inhibitory activity and act as antioxidants by scavenging free oxygen radicals. clinical studies have concluded that essential oils are effective in reducing plaque, gingivitis and halitosis due to their bactericidal and plaque-permeating abilities (20). breath also contains cetylpyridinium chloride is a quaternary ammonium compound with antiseptic and antimicrobial properties. it is cationic and thus binds to bacterial surfaces causing disruption of the cell membrane, leakage of intracellular components and disruption of metabolism. mouthwashes containing cetylpyridinium chloride inhibit and reduce plaque build-up. (21) close up and aquafresh also contain cetylpyridinium chloride as active ingredient in their composition, while sensodyne contain only sodium fluoride. all the mouthwashes used revealed antimicrobial activity against the three microorganisms used even when these mouthwashes were diluted but the concentrated mouthwash had the strongest antimicrobial activity. al-mansour mouthwash an iraqi mouthwash was the best one according to the results of this study. a mouthwash may be recommended to treat infection, reduce inflammation, relieve pain, and reduce halitosis or to deliver fluoride locally for caries prevention. mouth-rinsing is easier to perform and may aid in controlling supragingival plaque and gingivitis, but it should always be used in conjunction with mechanical hygiene references 1. prashant gm, chandu gn, murulikrishnaks, shafiulla md. the effect of mango and neem extract on four organisms causing dental caries: streptococcus mutans, streptococcus salivavius, streptococcus mitis, and streptococcus sanguis: an in vitro study. indian j dent res 2007; 18(4): 148-151. (ivsl). 2. mogammad tp, charlene wj, lawrence xg, johan m, abdul majeed n. an in-vitro analysis of the antimicrobial efficacy of herbal toothpastes on selected primary plaque colonizers. int j clini dent sci 2011; 2(3): 28-32. 3. van gemert-schricks mcm, van amerongen we, ten cate jm, aartman iha. the effect of different treatment strategies on the oral health of children: a longitudinal randomized controlled trial. clin oral invest 2008; 12: 361-8. 4. loesche wj. role of streptococcus mutans in human dental decay. microbiol rev 1986; 50: 353-80. 5. agbelusi ga, odukoya oa, otegbeye af. in vitro screening of chewing stick extracts and sap on oral pathogens: immune compromised infections. biotechnology 2007; 6(1): 97-100. 6. oztan md, kiyan m, gerceker d. antimicrobial effect, in vitro, of gutta-percha points containing root canal medications against yeasts and enterococcus faecalis. oral surg oral med oral pathol oral radio endod 2006; 102: 410-6. 7. lowy fd. staphylococcus aureus infections. n engl j med 1998; 339(8): 520-32. 8. zmantar t, kouidhi b, hentati h, bakhrouf a. detection of disinfectant and antibiotic resistance genes in staphylococcus aureus isolated from the oral cavity of tunisian children. annals of microbiology 2012; 62(1): 123-8. 9. rodis om, shimono t, matsumura s, hatomoto k, matsuo k, kariya n. cariogenic bacteria and caries risk in elderly japanese aged 80 and older with at least 20 teeth. j am geriatr soc 2006; 54: 1573-7. 10. camile sf, lidija mi, michael jm. mouthwashes aust prescr 2009; 32:162–4. 11. taciano rc, alexandre sc, marcelo e b, marcelo h n and geraldo t j. metabolic activity of streptococcus mutans biofilms after treatment with different mouthwash formulations. braz j oral sci 10(1): 74-78. 12. dasanyake ap, rosemaa jm, caufield pw. distribution and determinants of mutans streptococci among african american children and association with selected variables. pediatr dent 1995; 17(3): 1926. 13. qanbar fh, al-mizraqchi as. the antimicrobial effect of aqueous and alcoholic extracts of eucalyptus leaves on oral mutans streptococci, lactobacilli and candida albicans (an in vitro study). j bagh college dentistry 2009; 21(4): 109-112. 14. ohara-nemoto y, haraga h, kimura s, kemoto tk. occurrence of staphylococci in the oral cavities of healthy adults and nasal–oral trafficking of the bacteria. j med microbiol 2008; 57: 95–99 (ivsl). j bagh college dentistry vol. 25(2), june 2013 antimicrobial activity basic sciences 191 15. mat ludin cm, mdradzi j. the antimicrobial activity of different mouthwashes in malaysia. malay j med sci 2001; 8: 14-8. 16. lorenz k, bruhn g, heumann c, netuschil l, brecx m, hoffmann t. effect of two new chlorhexidine mouth rinses on the development of dental plaque, gingivitis and discoloration. a randomized, investigator-blind, placebo-controlled, 3week experimental gingivitis study. j clin periodontol 2006; 33: 561-7. 17. amornchat c, kraivaphan p, dhanabhumi c, tandhachoon k, trirattana t, choonhareongdej s. effect of cha-em thai mouthwash on salivary levels of mutans streptococci and total iga. southeast asian j trop med pub hlth 2006; 37: 528-31. 18. marinho vcc, higgins jpt, logan s, sheiham a. fluoride mouth rinses for preventing dental caries in children and adolescents. cochrane database syst rev 2003; 3: cd002284. 19. jeevarathan j, deepti a, muthu ms, rathnaprabhu v, chamundeeswari gs. effect of fluoride varnish on streptococcus mutans counts in plaque of cariesfree children using dentocult sm strip mutans test: a randomizedcontrolled triple blind study. j indian soci pedodontics preventive dent 2007; 25(4): 157-163 (ivsl). 20. fine dh, furgang d, sinatra k, charles c, mcguire a, kumar ld. in vivo antimicrobial effectiveness of an essential oil-containing mouth rinse 12 h after a single use and 14 days' use. j clin periodontol 2005; 32: 335-40. 21. witt j, ramji n, gibb r, dunavent j, flood j, barnes j. antibacterial and antiplaque effects of a novel, alcohol-free oral rinse with cetylpyridinium chloride. j contemp dent pract 2005; 6: 1-9. j bagh college dentistry vol. 30(3), september 2018 impact of glycated 54 impact of glycated haemoglobin on salivary glucose among type 1 diabetic mellitus patients aged 18-22 years juman d. alkhayoun b.d.s., h.d.d., m.sc. (1) ban s. diab b.d.s., m.sc., ph.d. (2) abstract background: diabetes mellitus consists of a group of diseases characterized by abnormally high blood glucose levels. glycated haemoglobin (hba1c) is a form of haemoglobin used to identify the average concentration of plasma glucose over prolonged periods of time. it is formed in a non-enzymatic pathway by normal exposure of hemoglobin to high levels of plasma glucose, the main alterations observed in the saliva of type 1 diabetic patients are hyposalivation and alteration in its composition, particularly those related to the levels of glucose. the aim of the present study was to assess the effect of glycated haemoglobin level on the level of salivary glucose which may have an effect on oral health condition. materials and methods: the total sample composed of 50 adults aged 18-22 years. divided into two groups: 25 uncontrolled diabetes mellitus (hba1c > 7), 25 controlled diabetes mellitus (hba1c ≤ 7). stimulated salivary samples were collected under standardized condition according to the criteria of tenovuo and lagerlöf (1994). salivary glucose was estimated by using spectrophotometric analysis. the data were analyzed by using spss version 18 (statistical package for social sciences) to specify the statistical differences between the two groups. results: the data of the present study assessed the correlation coefficients of hba1c and salivary glucose and found that among uncontrolled diabetic group the relation between hba1c and salivary glucose was significantly in positive direction (r = 0.483 p<0.05). while among controlled diabetic group, there was no relation between hba1c and salivary glucose as the correlation coefficient was found to be equal to zero. conclusion: the measurement of glycosylated hemoglobin, that is one of the well-established means of monitoring glycemic control in patients with diabetes mellitus, had a positive effect on the level of salivary glucose as its level increase with increasing the severity of diabetic disease. (j bagh coll dentistry 2018; 30(3): 54-58) introduction elevated blood sugar levels and numerous systemic manifestations are the most characteristic features of diabetes mellitus (dm)(1). in the physiological state, pancreatic β-cells respond to hyperglycemia by producing insulin which will acts via receptors at various end organs to reduce the elevated glucose levels by converting glucose to glycogen, fats and other storage forms. in patients with dm, this normal response to elevated glucose level will be interrupted. this may be secondary due to an inability of the pancreas to produce the adequate amount of insulin. it is also possible that the produced insulin is not functioning properly as a consequence of receptor malfunction or intrinsic protein alteration. additionally, it may result from autoimmune process or antibodies being directed against the pancreatic β-cells receptors or both (2,3). four main types of diabetes mellitus have been defined: type 1 or insulin-dependent diabetes mellitus (iddm), type 2 or non-insulin dependent diabetes mellitus (niddm), gestational diabetes and diabetes related to other conditions. the forms of diabetes mellitus other than type 1 or type 2 are comparatively rare (4). type 1 diabetes is β-cell destruction, usually leading to absolute insulin deficiency. the cause of this type is either due to immune mediated or idiopathic (5). the term ‘glycosylated’ (nomenclature) was used initially, but it had been pointed out that ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ (1) assistant lecture, department of pedodontic and preventive dentistry, college of dentistry, university of baghdad. (2) professor, department of pedodontic and preventive dentistry, college of dentistry, university of baghdad. this term strictly refers to glycosides. therefore, the joint commission on biochemical nomenclature had proposed that the term ‘glycation’ was appropriate for any reaction that links a sugar to a protein, or in the particular case of a reaction with haemoglobin, the term "glycated hemoglobin" can be used (6). in the american diabetes association, hba1c had been referred to as a1c (5). it is a good indicator of average glycemic concentrations during the previous 90 to 120 days (7,8). american diabetes association recommend that a1c should be performed at least twice a year in patients who are meeting their treatment goals (and who have stable glycaemic control), and quarterly in patients whose therapy has changed or who are not meeting their glycaemic goals (5). erythrocytes are freely permeable to glucose. in cells, glucose attaches to the free amino ends of haemoglobin molecules, and this process, called non-enzymatic glycosylation that causes glycosylated haemoglobin to be formed directly in proportional to the blood glucose concentration. as the average erythrocyte life span is about 120 days, glycated haemoglobin levels give information on the mean average of blood glucose levels over the past 2 to 3 months (9). the normal hba1c level among individuals without diabetes falls between 4 and 6 percent, so for adults with diabetes, the target is to maintain hba1c levels of 7 percent or lower. hba1c levels above 9 percent reflect poorly controlled diabetes, which will need more aggressive management(10). hba1c values between 6% and 7% j bagh college dentistry vol. 30(3), september 2018 impact of glycated 55 were considered as assign of good control of the diabetes, hba1c values between 7.1% and 8% indicated moderated control, and hba1c value >8% were designated as poor control of diabetes(11). the use of glycated hemoglobin levels (hba1c) as a screening and diagnostic criteria for diabetes mellitus has been recommended because it is convenient, reflect long-term hyperglycemia, and reliable when standardized(12). however hba1c results will be misleading in certain situations (change in rbc life span) for example in haematological conditions where there is abnormal red cell turnover, or abnormal haemoglobin, or in renal or liver disease and in hemolytic anemias or in nutritional anemias such as iron deficiency anemia. in pregnancy, hba1c may be slightly lower. in the presence of abnormal haemoglobin or in conditions with altered red cell survival rates, hba1c results may not be reliable (9). glucose is the main product of dietary carbohydrate. it is found in traces (0.5-1 mg/100 ml) as free form in fasting saliva (13), while the level of glucose in whole mixed saliva is 1.5-1.9 mg/100 ml(14 ). individuals with type 1 diabetes mellitus and poor glycemic control (fbs 180mg/dl; hba1c >8) have elevated salivary glucose concentration as a result of hyperglycemia, reduction of the salivary glucose clearance, disturbance of the neuroregulatory mechanism of the salivary glands and increased permeability of the basal membrane of the parotid glands(15,16). the oral cavity is considered a mirror of the nutritional status of the body. karjalainen et al.(17) and belazi et al.(18) found that in type i diabetic mellitus patients (children and adolescents), there was an increase in salivary glucose levels which was significantly correlated with that of blood, suggesting that high blood glucose could increase the salivary glucose levels. amer, et al.(19) conducted a study on diabetic patients and found a significant association between the glucose levels in blood and saliva. the findings thereby indicated that salivary glucose evaluation might be a potential tool to monitor diabetics. alrawi(2009)(20) showed that the highest glucose value was represented in the saliva of the long duration diabetic group, followed by the newly diagnosed group then the control, but there was no statistical significant association between the glucose levels in serum and saliva(20). the present study was conducted among patients with type1 diabetic mellitus (controlled and uncontrolled) aged 18-22 years to assess the effect of the level of glycated haemoglobin on salivary glucose level that may have an effect on the oral health condition. the aim of the present study was to assess the effect of glycated haemoglobin level on the level of salivary glucose which may have an effect on oral health condition materials and methods in the present investigation, the study group included 50 diabetic adults, their age ranged from 1822 years of. they were examined at the diabetic and endocrinology center, al-kindy teaching hospital in baghdad city during the period from the 1st of november 2011 till the end of april 2012. they were all with confirmed diagnosis of type iddm with minimum duration of diabetes of at least 5 years (510years). the samples were divided into two groups based on the hba1c (5): 25 uncontrolled type 1 diabetes mellitus patients (hba1c > 7), and the other 25 patients were controlled type 1 diabetes mellitus (hba1c ≤ 7). saliva was collected for the diabetic patients at the same day of the blood sample aspiration for hba1c assessment by measuring the absorbance of the glycohemoglobin and the total hemoglobin fraction at 415 nm in comparison with a standard glycohemoglobin preparation carried through the test procedure (human-biochemical, 2011, germany). the collection of stimulated salivary samples was performed under standard condition according to tenovuo and lagerlöf(21). then biochemical analyses of salivary samples were done using spectrophotometric analysis. salivary glucose level was measured by enzymatic method glucose-oxidase method, according to srinivasan et al 2003)(22). glucose level concentrations of saliva were expressed in mg/dl. glucose conc.(mg/dl)= 𝐀𝐛𝐬𝐨𝐫𝐛𝐚𝐧𝐜𝐞 𝐨𝐟 𝐬𝐚𝐦𝐩𝐥𝐞 𝐀𝐛𝐬𝐨𝐫𝐛𝐚𝐧𝐜𝐞 𝐨𝐟 𝐬𝐭𝐚𝐧𝐝𝐚𝐫𝐞𝐝 ×100(standard conc.) statistical analysis and processing of the data were carried out using spss version 18. student's t-test and pearson correlation coefficients were used. the level of significance was accepted at p< 0.05, and considered highly significance when p< 0.01. results in the present study, table (1) illustrates that 25 uncontrolled patients with mean value for hba1c % (8.61±1.20) and minimum (7.30) and maximum (11.00), and from controlled diabetes mellitus included 25 patients with mean value (6.09±0.57) with minimum (4.50) and maximum (7.00). the correlation coefficient of hba1c and salivary glucose can be seen in table (2). this table shows that among uncontrolled diabetic group the relation between hba1c and salivary glucose was significant in a positive direction (r = 0.483 p<0.05). while among the controlled diabetic group, there was no correlation between hba1c and salivary glucose. j bagh college dentistry vol. 30(3), september 2018 impact of glycated 56 table (1): hba1c (%( (mean and standard deviation) among uncontrolled and controlled diabetic groups. biochemical tests uncontrolled diabetic controlled diabetic mean ±sd mini maxi mean ±sd mini maxi hba1c 8.61 1.20 7.30 11.0 6.09 0.57 4.50 7.0 table (2): correlations coefficients between hba1c and salivary glucose among uncontrolled and controlled diabetic groups discussion diabetes and oral diseases often look as the two sides of a coin, a lot of attention was paid to the level of metabolic control, as poor metabolic control had been shown to be related to diabetes-associated alterations in tissues and it was a key factor in the development of diabetic organ complications(23-25). therefore, it was assumed that poor glucose control would affect the occurrence of oral complications as well. changes in the salivary physiochemical proprieties had been reported among the diabetic group and it was considered as a risk factor affecting severity and occurrence of dental caries and periodontal diseases (26). hba1c reflects average plasma glucose over the previous 2–3 months in a single measure, which can be performed at any time of the day and does not require any special preparation such as fasting. these properties have made it the gold standard for assessing glycaemic control in people with diabetes and have resulted in its consideration as an option for assessing glucose tolerance in people without diagnosed diabetes. on the other hand, the hba1c result was influenced by several factors including anemia, abnormalities of hemoglobin, pregnancy and uremia(27). in addition, hba1c is insensitive in the low range and a normal hba1c cannot exclude the presence of diabetes(28). the present work was carried out to elucidate the relationship between the characteristics of type1 diabetes among some people in baghdad city in iraq. its aim was to obtain more precise information by selecting the subjects carefully and controlling the data analysis. the goal was to use homogenic study populations to be able to control for various confounding factors. type 1 and type 2 diabetes have differences in their genetic background, etiology, treatment strategies and the presence of complications. therefore, only subjects with type 1 diabetes were included in this work. two different study populations (previously diagnosed type 1diabetes) were used, divided them into two groups according the level of hba1c: uncontrolled type 1 diabetes mellitus (hba1c > 7) and controlled type 1 diabetes mellitus (hba1c ≤ 7) (9). tervonen and oliver(29) were the first to use multiple hba1c values to determine long-term metabolic control of diabetes. dividing patients into poorly controlled and controlled type 1 diabetes groups was used in safkanseppälä(30), where grouping was based on patients’ medical status in addition to glycated haemoglobin values. the study groups selected aged 18-22 years, as at these ages the type 1 diabetes mellitus are predominate. typically, type 1 diabetes mellitus occurs in young subjects with acute-onset with typical symptoms of diabetes together with weight loss and propensity to ketosis(28). the role of metabolic control in relation to oral health was considered a feasible target of investigation in young subjects, in whom metabolic control is the best, and often the only, indicator of the diabetic status, because complications are rare in these age groups, as the long-term effects of the disease are not yet obvious(31). accordingly, variation in the duration of diabetes is also more limited than in olds populations, in the present study only 5-10 years durations of diabetes were involved. in spite of that the high value of hba1c can indicate that the patient had hyperglycaemic periods during the past 2–3 months; these values do not give information about the actual situation at the time when the salivary test was performed. data of the present study gave information about the significant positive correlation between salivary glucose and salivary constituents uncontrolled diabetic controlled diabetic hba1c hba1c r p r p glucose 0.483* 0.015 0.000 1.000 *p<0.05 j bagh college dentistry vol. 30(3), september 2018 impact of glycated 57 hba1c among uncontrolled diabetes group, but not among controlled diabetes group, one can suggest that such significant relation appear only when high hba1c values (>7%) is present, these results were in agreement with costa et al.(32) study. while the present results were in disagreement with the study of darwazeh et al. (33) ,who reported that glucose levels in unstimulated mixed saliva was correlated with actual blood glucose levels but not with the hba1c values. this could be attributed to the differences in saliva collection techniques, glucose metabolic control methods, degrees of patient dehydration, and the wide age span. however, some researchers showed in their report that the measurement of salivary glucose concentration may also represent a simple, quick, and inexpensive method for screening of diabetic autonomic neuropathy(34). on the other hand, tenovuo et al.(35) found that high blood glucose did not result in any notable elevation of salivary glucose of some subjects. in conclusion, dental professionals need to have comprehensive knowledge of their diabetic patients, knowledge that the patient has diabetes is not sufficient to assess the effects of diabetes with respect to oral diseases and dental treatment. finally, co-operation and consultation between all the members of the team responsible for the treatment of patients with diabetes is highly recommended. references 1. skyler, j.s. insulin therapy in type1diabetes mellitus. in defronzo, r.a. (ed): current therapy of diabetes mellitus. st.louis, mosbyyear book. 8991; pp: 36. 2. phillips, w. manifestations of diabetes mellitus. j. of ophthalmic nursing and technology. 8991 ; 13(6): 255-261. 3. devendra d, liu e, eisenbarth gs. type 1 diabetes: recent developments. br. med. j. 2004; 328: 750-4. 4. harris mi .classification, diagnostic criteria, and screening for diabetes. in: diabetes in america. 2nd edition. national diabetes data group, national institute of health, national institute of diabetes and digestive and kidney diseases. nih publication no. 95–1468, p 15–36, 1995. 5. american diabetes association (ada). diagnosis and classification of diabetes mellitus. diabetes care.2007; 30:s42-s47. 6. roth m. “glycated hemoglobin,” not “glycosylated” or “glucosylated”.clin chem. 1983; 29:1991. 7. sacks db. global harmonization of hemoglobin a1c. clin chem. 2005; 51(4):681-683. 8. sultanpur cm, deepa k, kumar sv. comprehensive review on hba1c in diagnosis of diabetes mellitus. internat. pharmace scien rev& res.2010; 3(issue 2):119-124. 9. nitin s. hba1c and factors other than diabetes mellitus affecting it. singapore med j. 2010; 51(8): 616-622. 10. mccance dr, hanson rl, charles ma, jacobsson lt, pettitt dj, bennett ph. comparison of tests for glycated haemoglobin and fasting and two hour plasma glucose concentrations as diagnostic methods for diabetes.bmj.1994; 308(6940):13231328. 11. marshall sm. standardization of hba1c: good or bad? nat. rev. endocrinol. 2010; 6: 408–411. 12. saudek cd, herman wh, sacks db, bergenstal rm, edelman d, davidson mb. a new look at screening and diagnosing diabetes mellitus. j clin endocrinol metab. 2008; 93(7):2447-253. 13. sanjeev m, bansal v, garg s, atrejag, bansal s. the diagnostic role of saliva-a review. j clin exp dent. 2011; 3(4):314-320. 14. hashemipour m, nekuii f, amini m, aminalroaya a, rezyanian kachoii a, abdoli ar. a study of the relationship between blood and saliva glucose levels in healthy population as a noninvasive method for glucose measurement. j endocornal metab. 2001; 2: `4-10. 15. siudikiene j, machiulskiene v, nyvad b. dental caries increments and related factors in children with type 1 diabetes mellitus. caries res. 2008; 42: 354 -362. 16. jurysta c, bulur n, oguzhan b. salivary glucose concentration and excretion in normal and diabetic subjects. j. biomed. biotechnol. 2009; 209: 426 430. 17. karjalainen km, knuuttila ml, kaar ml. salivary factors in children and adolescents with insulindependent diabetes mellitus. pediatr dent. 1996; 18 (4): 306-311. 18. belazi ma, galli-tsinopoulou a, drakoulakos d, fleva a, papanayiotou ph. salivary alterations in insulin-dependent diabetes mellitus. int j paediatr dent. 1998; 8: 29-33. 19. amer s, yousuf m, siddqiui pq, alam j. salivary glucose concentrations in patients with diabetes mellitus–a minimally invasive technique for monitoring blood glucose levels. pak j pharm sci. 2001; 14(1): 33-37. 20. al-rawi nf. salivary constituents in relation to oral health status among a group of (type 1) diabetic children. a ph.d. thesis. college of dentistry, university of baghdad, 2009. 21. tenovuo j, lagerlöf f. saliva. in: textbook of clinical cardiology. thylstrup a and fejerskov o. 2nd ed. munksgaard, copenhagen. 1994, 17-43. 22. srinivasan a, maaly e, willy d. determination of glucose in blood using glucose oxidase. am. clin. biochem. 2003; 6:24-29. 23. diabetes control and complications trial research group. the effect of intensive treatment of diabetes on the development and progression of long-term complications in insulin-dependent diabetes mellitus. n engl j med. 1993; 329: 977–986. 24. reichard p, nilsson b-y and rosenqvist u. the effect of long-term intensified treatment on the development of microvascular complications of diabetes mellitus. n engl j med. 1993; 329: 304– 309. 25. wang ph, lau j and chalmers tc. meta-analysis of effects of intensive blood glucose control on late complications of type i diabetes. lancet. 1993; 341: 1306–1309. 26. edgar m, higham s. saliva and the control of plaque ph. in: edgar m, dawes c, o’mullane d, j bagh college dentistry vol. 30(3), september 2018 impact of glycated 58 eds. saliva and oral health. 3rd ed. london: british dental association; 2004: 86–102. 27. world health organization (who): definition, diagnosis and classification of diabetes mellitus and its complication. part 1: world health organization, geneva; 1999. 28. ryde´n l, standl e, bartnik m, et al. guidelines on diabetes, pre-diabetes, and cardiovascular diseases: full text. european heart journal.2007; 10:10931165. 29. tervonen j, oliver rc: long-term control of diabetes mellitus and periodontitis. j clin periodontol.1993; 20:431-435. 30. safkan-seppälä b. periodontal disease in insulindependent diabetics. ph.d thesis, university of helsinki, 2001. 31. karjalainen k. periodontal diseases, dental caries, and saliva in pre-diabetes, and cardiovascular diseases: full text. european heart journal.2007; 10:1093-1165. 32. costa cc, resende gb, souza jmet al. estudo das manifestaçoes bucais em crianças com diabetes e suas variáveis de correlaçao. arq. bras. endocrinol. metab. 2004; 48: 374—378. 33. darwazeh amg, macfarlane tw, mccuish a , lamey p-j . mixed salivary glucose levels and candidal carriage in patients with diabetes mellitus. j oral pathol med. 1991; 20: 280–283. 34. martí álamo s, jiménez soriano y, sarrión pérez mg. dental considerations for the patient with diabetes. j clin exp dent. 2011; 3(1): 25-30. 35. tenovuo j, alanen p, larjava h, vilikari j, lehtonen op. oral health of patients with insulindependent diabetes mellitus. scand j dent res. 1986; 94:338–346. الخالصة هو شكل من اشكال الهيموغلوبين أن اختبار الكاليكتيد هيموغلوبين الدم.بباالرتفاع الغير طبيعي لمستوى السكر من االمراض التي تتصف يمرض السكر عالية من خالل التعرض الطبيعي للهيموغلوبين لتراكيز ةانزيميغير يتكون بطرق وهو .زمنيةفترات خاللبالزما معدل تركيز كلوكوز الذي يستخدم لتحديد تلك وباالخصاللعاب, ات في محتوىتغييرانخفاض معدل تدفق اللعاب والسكري النوع االول هي رضلعاب مل تحدثان التغيرات الرئيسية التي .الكلوكوز الكلوكوز باللعاب و الذي مستوى تأثير مستوى الكاليكتيد هيموغلوبين على تقديرمدىهو الحالية الدراسة هدفان .باللعابالمتعلقة في مستويات الكلوكوز صحة الفم. يعكس حالة مصاب مريض 20و ( 1chba>7 (غير المنضبط يبداء السكرمصاب مريض 20 مجموعتين الى قسمواسنة 2281بعمر بالغ 05شملت الدراسة على حدد . (tenovuo and lagerlöf) 8991اعتمادا على طريقة قياسية ظروف عينات اللعاب المحفز ضمنجمعت .(1chba≤7 (المنضبط يبداء السكر .spssالضوئي وحللت النتائج احصائيا باستخدام مستوى الكلوكوز باللعاب بأستخدام المطياف غير المصابين بداء السكري كان معنويا وايجابيا عند المرضىاللعاب بكلوكوز المستوى مع 1chbaحالية بينت ان معامل االرتباط الدراسة ال نتائج أن ومستوى الكلوكوز باللعاب وان معامل االرتباط 1chba لم تتضح هكذا عالقة بينالمنضبط يالسكر داء مرضى( اما في r = 0.483 p< 0.05) المنضبط كان مساويا للصفر. على مستوى ي وله تاثير موجبالسكر داء السكري لدى مرضىلمتابعة مدى السيطرة على مرض المهمة احد الطرق وهون قياس الكاليكيتيد هيموغلوبين أ . يبزيادة شدة مرض داء السكرمستواه يزداد الكلوكوز باللعاب الذي 25shaymaa f.doc j bagh college dentistry vol. 28(3), september 2016 assessment of salivary pedodontics, orthodontics and preventive dentistry 155 assessment of salivary secretory immunoglobulin a (sig a) level during fixed orthodontic treatment shaymaa sh. taha, b.d.s., m.sc. (1) abstract background: the immune system of the oral cavity suffers alterations due to fixed orthodontic treatment which act as potent stimulus for oral secretory immunity. the aims of this study are to estimate the effect of fixed orthodontic appliance on the level of salivary siga at different time intervals, and to verify the gender difference. materials and method: the patient's history, clinical examination, and fixed orthodontic appliances were placed for 30 iraqi orthodontic adult patients had class ii division 1 and/ or class i malocclusion (15 males and 15 females) aged 18-25 years old. the unstimulated whole saliva was collected from each sample immediately before wearing fixed appliance (control group t0 as base line), and after 2 weeks (t1),1 month (t2), and 1year (t3) of wearing fixed orthodontic appliance. the levels of salivary siga were measured by enzyme linked immunosorbant assay kit (elisa). results: the mean value of salivary siga was elevated at t1 and reached the peak at t2 followed by declined at t3 to reach near the normal value at t0 (base line). repeated measure anova test showed statistically highly significant difference among four time intervals. the bonferroni test after repeated measure anova test showed highly statistical significant difference between each two time intervals except between t0 and t3 show significant difference. in addition there were no significant gender differences. conclusion: in this study one can conclude that fixed orthodontic appliance acts as an immunological stimulant in the oral cavity that changes the level of salivary siga which evaluate the immunity status in the oral cavity. key wards: saliva, salivary siga, fixed orthodontic treatment. (j bagh coll dentistry 2016; 28(3):149-154). introduction saliva is important body fluid and exceptional compound which composed of a number of systems which work for a wide spectrum of physiological needs to guard the oral mucosa and the entire body from infection (1,2). immunoglobulin a (iga) is an antibody that has a critical role in mucosal immunity. the production of iga in mucosal lining is more than all other kinds of antibody together, 3-5 gm iga are secreted into the intestinal lumen per day (3). mucosal secretory immunoglobulin a (siga) is formed through two distinctive pathways, namely t cell dependent and independent pathway (4). the siga can withstand the cruel environment of gastrointestinal tract and be responsible for defense against microbes that reproduce in body secretions because the secretory component of siga keeps the immunoglobulin from being fragmented by proteolytic enzymes (5). also siga can inhibit inflammatory effects of other immunoglobulins and it is a poor activator of the complement system and opsonizes just weakly (6). the siga antibodies avoid adherence and penetration of antigens and high level of siga could avoid allergen absorption, while low levels of siga and transient iga deficiency have been associated with an improved possibility for allergy and bronchial hyper-reactivity (7). secretory iga is a secretory factor for acquired immunity in the oral cavity. antibodies of this type play a part in the maintenance of the integrity (1) lecturer. department of orthodontics, college of dentistry, university of baghdad of the oral surfaces (enamel and mucous membrane) and become part of first line of defense through limiting the microbial adhesion. the siga antibodies independently, or in complexes, take part in antigen-antibody reactions on the mucous membrane (and partly on the enamel too), thus restrict the penetration of bacteria and toxins (8-10). the largest amount (90%) of siga is synthesized by the parotid and submandibular salivary glands .the plasma cell of these glands secrete dimeric immunoglobulin a, that relates with a secretory particle to proteolysis, and secreted by the epithelial cells of the acini (11). recognition of siga antibodies in saliva may aid to identify liable patients before development of orthodontically induced root resorption (12). the tipping movements is the easiest type of orthodontic tooth movement (otm) which are formed when single force is employed toward the crown of the tooth, for the duration of this movement the pdl are compressed (bone resorption) adjacent to the root apex on the similar side of the applied force and the crest of alveolar bone on the opposed side. in bodily movement, bone resorption takes place along side the whole alveolar surface on the pressure side, while bone deposition takes place along side the alveolar surface on the tension side (13). the state of calcium metabolism in alveolar bone affects the tooth movement that is directly applicable to orthodontics. in addition the bone metabolism occurs in the alveolar process and basilar bone of law (14). the calcium hemostasis is a procedure which preserves the mineral equilibrium, which is j bagh college dentistry vol. 28(3), september 2016 assessment of salivary pedodontics, orthodontics and preventive dentistry 156 associated by their temporarily related mechanisms 1. quick flow of calcium from bone (within few seconds) 2. little term response of osteoclast and osteoblast (from minutes to days) (14). at starting of orthodontic tooth movement, the mechanical stimulus lead to an acute inflammatory response inside the periodontal tissues, subsequently initiates the biologic processes which result in bone resorption to provide accommodations of the tooth movement (15). compression sites are categorized by tissue and cell destruction, and partial blood vessels disintegration causes hypoxia and ischemia, these changes initiate an acute inflammatory response (16). this process is started when local hypoxia increases the expression of il-1ß, il-6, il-8, and tnf-α in pdl fibroblast (17). in addition, orthodontic treatment is very often related to gingival inflammation, as a consequence of the local alteration in microbial ecosystem and in the content of the bacterial plaque. during orthodontic treatment, patients with good oral hygiene may develop gingival inflammation. when fixed orthodontic appliances are used, mild to moderate gingivitis with gingival enlargement and bleeding on probing is obvious (18-21). the inflammatory cell infiltration on periodontal tissues occurs due to forces of orthodontic movement, formed signals and cytokines for differentiation and activation of clast cells (22,23). the chronic inflammatory process can promote the production of autoantigens to the immune system and break the immunological tolerance (24). the salivary glands secreted large amounts of secretory iga (siga) into saliva, which is the main line of defense of the oral cavity and upper respiratory tract surfaces (24). the aims of the current study are estimation the effect of fixed orthodontic appliance on the level of salivary secretory iga (siga) at different time intervals and to verify the gender difference. materials and methods the sample: a total of 30 iraqi adult orthodontic patients (15 males and 15 females) aged 18-25 years old with angle’s class ii division 1 and/or class i malocclusion cases were selected from patients attended the orthodontic clinic in the orthodontic department at the college of dentistry, university of baghdad. patients' history was taken and clinical examination was done, then fixed orthodontic appliances were bonded. exclusion criteria the exclusion criteria are none of the patients reported acute or chronic inflammatory or autoimmune diseases, systemic disease, previous facial and orthodontic surgical treatment, previous trauma of the primary or permanent teeth, smoking, or the usage of steroidal and nonsteroidal anti-inflammatory medications for at least a month before sampling, pregnancy and lactating patients, clinical signs of periodontal disease, periapical lesions, or root resorption, and oral mucosa lesions or active caries before bonding. orthodontic materials (figure 1-a) stainless steel orthodontic brackets roth 0.022 (orthotechnology), molar tubes (orthotechnology), ligature wire (preformed ligture ties shorty 0.10 inch ortho technology), light cure orthodontic adhesive (orthotechnology), nickel titanium arch wire 0.014 inch round (ortho technology) for t1 and t2, and 0.021x0.025 inch rectangular stainless steel wire (orthotechnology) for t3. saliva collection and storage the saliva sample in this study was collected at fixed time between 9 a.m.-12 p.m. the collection period was 10 minutes and the patients were instructed not to drink or eat or chew gum (except water) at least 1 hour before saliva collection. each patient rinsed his mouth several times with water and waited 1-2 minutes for clearance of water, then sat in a restful position on the chair and instructed to open his lips slightly. the patients asked to drool passively unstimulated saliva over the lower lip into sterile plane plastic test tube. the patients instructed not to spit into test tube and not to swallow during saliva collection (25). the plane test tube(figure 1-b) with 5 ml unstimulated saliva samples were collected, coded, organized in the rack, and stored in cooling box containing ice containers after collection to stop growth of bacteria, then the samples were carried out to immunologic laboratory in the teaching laboratories of baghdad medical city, at the same day the coded test tube with saliva sample centrifuged at 3000 rpm for 10 minutes(figure 1-c) and then immediately the clear supernatants layer was collected by adjustable pipette(figure1-d) into labeled eppendrof tubes which were set in eppendroffs rack (figure 1-e )and stored at -20º c in a deep freeze until analysis (26). j bagh college dentistry vol. 28(3), september 2016 assessment of salivary pedodontics, orthodontics and preventive dentistry 157 saliva was collected from each patient at base line t0 (immediately before fixed orthodontic appliance wearing), t1 (after 2 weeks of fixed orthodontic appliance wearing), t2 (after 1 month of fixed orthodontic appliance wearing), and t3 (after 1 year of fixed orthodontic appliance wearing). the level of salivary secretory siga was measured by enzyme linked immunosorbant assay kit (elisa) (27) demeditec secretory iga elisa kit (dexk276) germany (figure 1-f), microplate elisa washer (figure 1-g), biorad microplate elisa reader australia (figure 1-h) and printer of elisa reader (figure 1-i). the elisa test procedures were reagent preparation and assay procedure according to elisa kit instructions. the optical density measured at 450 nm, the photometer blank was set on the first calibrator then point by point method was used for data reduction using calculating factor (1.0) to calculate analyte factor for saliva as mentioned in instructions for use of siga elisa kit. calculation of results (table 1) as mentioned in siga elisa kit instructions, the siga concentration (µg/ml) in saliva samples was obtained by: 1. calculate the mean absorbance values (od450) for each pair of calibrators and samples 2. plot a calibration curve od on the y-axis versus secretory iga concentration on the xaxis. 3. determine the corresponding concentration of siga (µg/ml) in unknown samples from the calibration curve, and then computerized data reduction was applicable. pointbypoint or linear data reduction is recommended. table 1: calculation of the result (demeditec siga elisa kit instructions) absorbance units (450nm) concentration value (µg/ml) calibrators 0.10 0 cal1 0.14 2 cal2 0.33 20 cal3 0.57 40 cal4 1.03 100 cal5 2.17 400 cal6 statistical analysis data were collected and statistically analyzed by a software computer program spss (statistical package of social science) software version 15 for windows xp chicago, usa. the following statistics were used: a. descriptive statistics: means, standard deviations, minimum and maximum values. b. inferential statistics: including the following test: 1. independent t-test: to compare statistically the mean value of siga level for each time interval between both genders. 2. repeated measure anova test: to test any statistically significant difference among time intervals for the mean value of siga level. 3. bonferroni test: to compare between each two time intervals of siga level when anova test showed a statistically significant difference. in the statistical evaluation, the following levels of significance are used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results and discussion salivary siga can be considered as a marker for evaluation of immune status in the oral cavity during fixed orthodontic treatment. the descriptive statistics of each gender and gender difference using independent t-test for the mean values of salivary siga level (µg/ml) at different time intervals t0, t1, t2, and t3 showed in table (2). the descriptive statistics of total sample for the mean value of salivary siga level (µg/ml) at different time intervals showed in table (3). the comparison of the salivary siga level (µg/ml) among t0, t1, t2, and t3 was done using repeated measure anova test as shown in table (4), followed by bonferroni test for the measurements that showed significant difference as shown in table (5). as revealed in table (2), the independent t-test showed non-significant gender difference, this agreed with eliasson et al. (28) and youness et al. (29), so sample was pooled in table (3). table (3) and figure (2) showed descriptive statistics of total sample for the mean value of salivary siga level (µg/ml) at different time intervals. the mean value of siga level elevated following fixed orthodontic appliance in total sample at t1 and reached the peak at t2 followed by a decline at t3 to reach near the normal value at t0, these elevations of the mean value of siga level (µg/ml) at t1 and t2 might be caused by the innate immune response after fixed orthodontic appliance wearing which had some cytokines that affect the siga production and delivery on the mucosal surface. the orthodontic force induced interleukin-1 (il-1) and tumor necrosis factoralpha (tnf-α) which are inflammatory cytokines j bagh college dentistry vol. 28(3), september 2016 assessment of salivary pedodontics, orthodontics and preventive dentistry 158 of the innate immune response (22,30-32), both cytokines can motivate siga delivery from mucosal surface and exchange throughout the epithelial barriers and induce clast differentiation and activation (33,34). cytokines, such as 1l-4, il5, il-10, and tgf-ß favouring antibody production and inhibiting clast activation (24,33,35). salivary siga could control local clast activation. however, a local inflammatory response could induce an imbalance in the autoimmune response and could tend to activation of clast cell (12). during orthodontic tooth movement compression areas and hyaline necrosis in the periodontium may damage the cementum layer and expose the dentin matrix (23), the damaged periodontal tissue causes inflammation which can result in reorganization of antigen-presenting cells and can lead to the expression of co-stimulatory molecules that tend more to lymphocytes activation (36,37). the orthodontic appliance materials were exposed to microbial adhesion that decrease oral hygiene and produce new retentive areas for plaque and debris and possibility of subsequent infection. fixed orthodontic appliance stimulates continuous accumulation and retention of microbial growth. recent reports suggest that is difficult to eliminate the microbial growth or maintain the hygienic status of the fixed orthodontic appliances at the critical zones (38). the metal of orthodontic appliance inside the oral cavity can cause increase in concentration of metal ions which cause increase in biofilm biomass (39). the orthodontic biomaterial components release potential allergens such as metal ions from the base metal alloys in orthodontic fixed appliances, and resin based bonding materials, the intra-oral orthodontic materials may lead to pathomorphological variations in the mouth and antigen stimulation (40). fixed orthodontic appliances composed from many metallic ions as chromium, cobalt, and nickel. these metallic ions and monomers released from orthodontic adhesive materials have a strong effect on oral secretory immunity (41), nickel is a strong immunologic sensitizer, and nickel sensitivity is lower in subjects with orthodontic treatment (42). table (4) was repeated measure anova test for comparing the salivary siga level (µg/ml) among t0, t1, t2, and t3. the results showed highly significant difference among time intervals. table (5) was bonferroni test which showed highly significant difference between each two time intervals (t0 and t1, t0 and t2, t1and t2, t1 and t3, t2 and t3) except between t0 and t3 where it was significant difference. the salivary siga level declined at t3 to reach near the normal value at t0, so there is significant difference between t0 and t3, this result may be due to that patients with long duration fixed orthodontic treatment perhaps they develop immunological tolerance (42). so in this study one can conclude that fixed orthodontic appliance acts as immunological stimulant in the oral cavity which change the level of salivary siga at different time intervals that evaluate the immunity status of the oral cavity, because fixed orthodontic appliances after two weeks and four weeks of wearing cause highly significant difference in the level of salivary siga in both genders during active orthodontic treatment, while after 1 year the level of salivary siga return nearly to the normal value. the current study is a unique study for determination the siga level (µg/ml) at these time intervals t0, t1, t2, and t3 during fixed orthodontic treatment. figure 1: equipment and materials used in this study: a. orthodontic instruments and materials b. test tubes c. centrifuge machine d. adjustable pipette e. eppendrof tubes in rack f. secretory iga elisa kit g. micro plate elisa washer h. micro plate elisa reader i. printer of elisa reader j bagh college dentistry vol. 28(3), september 2016 assessment of salivary pedodontics, orthodontics and preventive dentistry 159 table 2: descriptive statistics of each gender and gender difference for salivary siga (µg/ml) level duration gender descriptive statistics genders' difference n mean s.d. t-test d.f. p-value t0 males 15 137.84 3.72 -0.681 28 0.501 (ns) females 15 138.80 4.03 t1 males 15 373.39 3.77 -0.309 28 0.759 (ns) females 15 373.82 3.84 t2 males 15 478.41 4.43 -0.057 28 0.955 (ns) females 15 478.50 3.85 t3 males 15 140.15 3.36 -1.023 28 0.315 (ns) females 15 141.43 3.50 table 3: descriptive statistics of total sample for salivary siga (µg/ml) level duration n min max mean s.d. t0 30 133.04 144.87 138.32 3.84 t1 30 367.91 379.75 373.61 3.75 t2 30 472.07 484.69 478.46 4.08 t3 30 135.14 146.45 140.79 3.43 table 4: repeated measure anova test for siga level at different time intervals source type iii sum of squares d.f. mean square f-test sig. partial eta squared duration sphericity assumed 2627026.757 3 875675.586 80897.115 0.000** 1.000 greenhouse-geisser 2627026.757 2.833 927408.305 80897.115 0.000** 1.000 huynh-feldt 2627026.757 3 875675.586 80897.115 0.000** 1.000 lower-bound 2627026.757 1 2627026.757 80897.115 0.000** 1.000 error (factor1) sphericity 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walport m. immunobiologia. artmed, porto alegre; 2007. 36. vandevska-radunovic v,kvinnsland i h,kvinnsland s, jonsson r. immunocompetent cells in rat periodontal ligament and their recruitment incident to experimental orthodontic tooth movement. european j oral sci 1997; 105: 36-44. 37. alhashimi n, frithiof l, brudvik p, bakhiet m. cd40-cd40l expression during orthodontic tooth movement in rats. angle orthod 2004; 74:100-5. 38. pandurangan h, thillali s s, varadharajan k, arumugam g. microbial adhesion on orthodontic ligating materials: an in vitro assessment. sci res publ 2013; 3:108-14. 39. muggiano f, quaranta a, previati m. candida albicans: colonization, role and effect of this opportunistic pathogen on orthodontics. web med central orthodontic appliances 2014; 5(1): wm coo4489. 40. schuster g, reichle r, ranei bauer r, schopf pm. allergies induced by orthodontic alloys: incidence and impact on treatment. j orofacial orthop 2004; 65: 4859. 41. cigden g, ebubekir t, firat o, dilek g, aysun bk, onder o. evaluation of salivary total oxidantantioxidant status and dna damage of children undergoing fixed orthodontic therapy. angle orthod 2015; 85: 239-44. 42. dilip dq, kishna n, suchetha fn, prashant p, vijay r, ajay d. in vivo analysis of lipid peroxidation and total antioxidant status in subjects treated with stainless steel orthodontic appliances. nitti university j health science 2013; 3(3): 83-6. j bagh college dentistry vol. 29(1), march 2017 periodontal health oral and maxillofacial surgery and periodontics 89 periodontal health status and assessment of osteocalcin levels in saliva of diabetic patients and systemically healthy persons (comparative study) zina ali daily, b.d.s. (1) ayser najah mohammed, b.d.s., m.sc. (2) abstract background: diabetes and periodontitis are complicated prolonged disorders through a recognized two-way association. there is elongated-conventional mark that hyperglycaemia in diabetes is affected on immuneinflammatory response and disturb the action of osteoclast and in balance bone turnover, which might rise the person vulnerability to the progress of prolonged periodontitis. osteocalcin is one of the greatest plentiful matrix proteins originate in bones and produced absolutely there. small osteocalcin crumbles are noticed in regions of bone remodeling and are in fact degradation products of the bone matrix, that is released outside cells into the gingival crevicular fluid (gcf) and saliva after destruction of periodontal tissue during periodontitis materials and methods: eighty patients with type2diabetes maleates (t2dm), males and females, were recruited for the study, with an age range of (30-50) years were divided into four groups, (20 subjects each): poorly controlled type 2diabetes mellitus with chronic periodontitis group (cp+pt2dm ) and well controlled type 2diabetes mellitus with chronic periodontitis group(cp+wt2m) , group of patients with only chronic periodontitis (cp )and control group with healthy periodontium and systemically healthy. from all subjects five ml of unstimulated whole salivary samples were collected, then, the samples were centrifuged and the supernatants were collected and kept frozen until the biochemical analysis to measure oc concentrations then clinical periodontal parameters (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment loss) were recorded for all subjects at four sites per tooth except for the third molars. results: the results of this study revealed highly significant differences among all study and control groups for all the clinical periodontal parameters (plaque index, probing pocket depth, clinical attachment loss) ,and oc concentrations. additionally patients had chronic periodontitis with poorly controlled type 2diabetes mellitus(cp+pt2dm )demonstrated the highest median values of all clinical periodontal parameters and highest increase in levels of salivary oc followed by cp+wt2m group then cp and control groups. the current study demonstrates the correlation between oc concentrations with each one of the clinical parameters.it revealed highly significant strong positive correlations with pli, gi and bop score 1, while highly significant strong negative correlations with ppd. also, non-significant weak positive correlation existed with cal in cp+pt2dm group. also, high significant strong positive correlation with pli, gi, bop and cal; while, non-significant weak positive correlation with ppd in cp+wt2m group . high-significant strong positive correlation with bop and cal, as well as, high significant moderate positive correlation with ppd and significant weak positive correlation with pli, while non-significant weak positive correlation with gi existed in cp group .finally, high significant moderate positive correlation with pli and gi existed in the control group. conclusion: patients with poor glycemic control had more severe periodontal tissue break down with increase in levels of oc than well controlled type 2 diabetic patients and non-diabetic patients all of them with chronic periodontitis. so, this biochemical marker may be useful of periodontal tissue destruction and allowed practitioners for early diagnosis, prognosis and efficient management of periodontal diseases and type 2 diabetes mellitus keywords: periodontitis, type 2diabetes mellitus, salivary osteocalcin..(j bagh coll dentistry 2017; 29(1):89-95). introduction 2diabetes mellitus (dm) is a multisystem disorder considered as a relatively or absolutely inadequacy of insulin secretion and/or associated resistance to the metabolic action of insulin on target tissues(1, 2).the dm is regarded as a hyperglycemia and t2dm is susceptible to oral complications such as periodontal disease (pd), dry mouth and abscesses (3, 4). periodontitis is an inflammatory lesion that is attended by soft tissue impairment and bone resorption in the tooth supportive structures. (1) master student. department of periodontics, college of dentistry, university of baghdad. (2) assistant professor, department of periodontics, college of dentistry, university of baghdad it has a multifactorial etiology and the distinguishing tissue destruction is mediated essentially by the aberrant immune response of different inflammatory periodontal diseases (5). the greatest communal form of periodontitis is the chronic periodontitis (cp) that characteristically disturbs adults between 40 to 50 years old and is branded by its slowly progressing nature, but at particular point suffers exacerbation(6). osteocalcin is a calcium-connecting protein of bone and is the greatest plentiful non collagenous protein in mineralized tissues. osteocalcin is synthetic mostly by osteoblasts, odontoblasts and hypertrophic chondrocytes and it has an imperative role in bone formation and turnover. it has also been exposed to promote bone j bagh college dentistry vol. 29(1), march 2017 periodontal health oral and maxillofacial surgery and periodontics 90 resorption, and stimulate differentiation of osteoclast progenitor cells, that may be involved in employing osteoclasts to positions of recently formed bone and as a result may role as a negative regulator. osteocalcin is currently an effective marker of bone turnover when resorption and formation are coupled and is a particular marker of bone formation when formation and resorption are uncoupled (7, 8). osteocalcin is the hormonally active isoform and stimulates insulin discharge and increases insulin sensitivity in adipose tissue and muscle. the places of the skeleton act as a true endocrine organ in a traditional feedback mechanism (9). there has been association between t2dm, pd and numerous indicators in saliva (10). these have interested us to make the present study, so as to assess the salivary oc levels in t2 diabetic patients with cp to establish the result of the glycemic regulator on their stages and the extent of the periodontal damage. materials and methods the human sample consists of 80 patients with t2dm, males and females, with age range of (3050) years. the collection of the subjects recruited for the study were patients attending the diabetic department of imam alhussein medical city, as well as, patients from specialized dental center in karbala city. the subjects were divided into four groups: a. cp with poorly controlled t2dm (cp+pt2dm): consisted of 20 males and femaies with cp and hba1c > 9%. b. cp with well controlled t2dm (cp+wt2dm): consisted of 20 males and femals with cp and hba1c < 7%. c. systemically healthy with chronic periodontitis (cp): consisted of 20 males and females with cp. chronic periodontitis in patients was defined as the presence of minimally four sites with ppd ≥ 4 mm and clinical attachment loss of (1-2) mm or greater(11). d. systemically healthy with healthy periodontium (control): consisted of 20 males and females apparently systemically healthy and with clinically healthy periodontium, this was defined by gingival index (gi) scores <0.5 (12) and without periodontal pockets or clinical attachment loss. this group represents a base line data for the levels of salivary oc. inclusion criteria: males and females with t2dm (diabetic for 5 years) on oral hypoglycemic therapy only, at least 20 teeth present (13). while, the exclusion criteria included:, t1dm and t2dm administering insulin, smoking and alcohol consumption, presence of systemic diseases other than t2dm, presence of nephropathy, retinopathy and diabetic foot, patients who've undergone periodontal treatment or administrated medications (antiinflammatory, anti-microbial and antidepressants) in the three months prior to the study and pregnant, lactating and menstruation cycle . from all subjects five ml of unstimulated whole salivary samples were collected from all of the groups at 9-12 a.m. (14). then the samples were centrifuged at 4000 rpm for 15 min. and frozen at 20 ͦ c. clinical periodontal parameters examination was performed after collecting the salivary samples by using the michigan o periodontal probe on four surfaces (mesial, buccal/ labial, distal and lingual/palatal) of all teeth except the third molar. these included: 1. assessment of soft deposits by the plaqueindex system (pli) (15). 2. assessment of gingival inflammation by thegingival index system (gi) (12). 3. assessment of gingival bleeding on probing (bop) (16). 4. assessment of probing pocket depth (ppd). 5. assessment of clinical attachment level (cal). for the purpose of biochemical analysis of salivary oc, this was done by enzyme linked immunosorbent assay (elisa) technique by using kit manufactured by (shanghai yehua, china). the study variables were statistically analyzed using statistical process for social science (spss version 19) by using median, minimum, maximam, percentage and inferential statistics in the form of kruskal-wallis h test, mann-whitney u test and pearson correlation were used in this study. the levels of significant (s) was accepted at p-value < 0.05, highly significant (hs) at p value < 0.01 and nonsignificant (ns) at p-value > 0.05. results the results of this study revealed highly significant differences among all study and control groups for all the clinical periodontal parameters (plaque index, probing pocket depth, clinical attachment loss) that demonstrated in the results of kruskal-wallis h test (x2 ), as shown in (table -1). the highest median value of pli (2.76) was in the cp+pt2dm, followed by cp+wt2dm was (2.27) then cp was (1.15) and finally the control group demonstrated the lowest median value was (0.42).while the highest median value of gi (2.27) was in the cp+pt2dm, followed by cp+wt2dm was (1.99) then cp was (1.08) and the control group demonstrated the lowest median value was (0.55). likewise, the highest median percentage value of j bagh college dentistry vol. 29(1), march 2017 periodontal health oral and maxillofacial surgery and periodontics 91 bop sites found in cp+pt2dm was (37.7), followed median percentage was found in cp+wt2dm (28.7), while lowest median percentage of bop for cp (27.3).additionally, cp+pt2dm showed the highest median value of "ppd" was (6.35) among the study groups followed by cp+wt2dm which was (5.31) and cp group was (4.43). regarding cp+pt2dm showed the highest median value of "cal" was (4.66) among the study groups followed by cp+wt2dm was (3.73) and cp group was (2.6). inter study groups comparisons regarding all clinical periodontal parameters revealed, hs differences between cp + pt2dm with both cp + wt2dm, cp groups and control groups (table 2). the biochemical analysis (table-3) in the levels of salivary oc of the study group cp+pt2dm showed the highest median value of oc among the four groups, the median value was (55.60), followed by cp+wt2dm with median value of (38.90) then cp group with median value of (25.99), finally the lowest median value was (8.46) which demonstrated by control group, that showed in figure(1) for median values of osteocalcin concentrations (ng/ml) for the study and control groups. the results of the comparisons for all pairs of the study and control groups in (table-4) about biochemical parameters levels revealed: highly significant differences between control group and all of the study groups. the current study demonstrates the correlation between oc concentrations with each one of the clinical parameters.it revealed highly significant strong positive correlations with pli, gi and bop score 1, while highly significant strong negative correlations with ppd also, non-significant weak positive correlation existed with cal in cp+pt2dm group.also, high significant strong positive correlation with pli, gi, bop and cal, while non-significant weak positive correlation with ppd in cp+wt2m group.high-significant strong positive correlation with bop and cal, as well as, high significant moderate positive correlation with ppd and significant weak positive correlation with pli, while nonsignificant weak positive correlation with gi existed in cp group.finally, high significant moderate positive correlation with pli and gi existed in the control group. table 1: analytic statistics in clinical parameters for the study and control groups variables groups n median x2 p-value pi control 20 0.42 72.216 0.000 chronic periodontitis 20 1.15 well control d.m.+cp 20 2.27 poor control d.m.+cp 20 2.76 gi control 20 0.55 67.757 0.000 chronic periodontitis 20 1.08 well control d.m.+cp 20 1.99 poor control d.m.+cp 20 2.27 bop chronic periodontitis 20 27.3 21.731 0.000 well control d.m.+cp 20 28.7 poor control d.m.+cp 20 37.7 ppd chronic periodontitis 20 4.43 43.095 0.000 well control d.m. +cp 20 5.31 poor control d.m. +cp 20 6.35 cal chronic periodontitis 20 2.6 50.060 0.000 well control d.m. +cp 20 3.73 poor control d.m. +cp 20 4.66 j bagh college dentistry vol. 29(1), march 2017 periodontal health oral and maxillofacial surgery and periodontics 92 table 2: comparison between each two groups in clinical parameters groups test pi gi bop ppd cal control vs. periodontitis mann-whitney u 0 14.5 p-value 0.000 0.000 control vs. well control d.m. mann-whitney u 0 0 p-value 0.000 0.000 control vs. poor control d.m. mann-whitney u 0 0 p-value 0.000 0.000 periodontitis vs. well control d.m. mann-whitney u 0 5 109.5 41 17 p-value 0.000 0.000 0.014 0.000 0.000 periodontitis vs. poor control d.m. mann-whitney u 0 0 53 4 0 p-value 0.000 0.000 0.000 0.000 0.000 well control d.m. vs. poor control d.m. mann-whitney u 27 82 73.5 26.5 2 p-value 0.000 0.001 0.001 0.000 0.000 table 3: analytic statistics of osteocalcin concentrations (ng/ml) for the study and control groups variables groups n median x2 p-value osteocalcin control 20 8.46 74.074 0.000 chronicperiodontitis 20 25.99 well control d.m. +cp 20 38.90 poor control d.m. +cp 20 55.60 figure 1: bar chart for median values of osteocalcin concentrations (ng/ml) for the study and control groups table 4: comparison between each two groups of osteocalcin concentrations (ng/ml) for the study and control groups groups mann-whitney u test p-value sig cp+pt2dm cp+wt2dm 0 0.000 (hs) cp 0 0.000 (hs) control 0 0.000 (hs) cp+wt2dm cp 0 0.000 (hs) control 0 0.000 (hs) cp control 0 0.000 (hs) 8.46 25.99 38.9 55.6 0 10 20 30 40 50 60 control periodontitis well control d.m.poor control d.m. o st e o ca lc in groups j bagh college dentistry vol. 29(1), march 2017 periodontal health oral and maxillofacial surgery and periodontics 93 table 5: correlations between the levels of osteocalcin with the clinical parameters of each study and control groups parameters statistical analysis cp+pt2dm cp+wt2dm cp control pli r 0.900 0.911 0.430 0.663 p-value 0.000 0.000 0.058 0.001 sig hs hs s hs gi r 0.901 0.999 0.317 0.687 p-value 0.000 0.000 0.174 0.001 sig hs hs ns hs bop r 0.919 0.998 0.636 p-value 0.000 0.000 0.003 sig hs hs hs ppd r -0.761 0.299 0.539 p-value 0.000 0.201 0.014 sig hs ns hs cal r 0.032 0.645 0.754 p-value 0.895 0.002 0.000 sig ns hs hs discussion in diabetic patients, the decrease in the volume of saliva and buffering capacity in addition to the variation in bacterial flora. altogether, these factors produce greater accumulation of plaque (17). furthermore, the harmful effects of advanced glycation end products and receptor for advanced glycation end products (ages-rages) interactions in the periodontium of diabetic patients that comprise: increase vascular permeability, impaired wound healing and vascular variations contribute to further periodontal destruction (18).diabetic is related with complications, such as inflammation, (ages) (19), microangiopathy (20), macroangiopathy (21). the combination of these abnormalities makes diabetic patients vulnerable to bacterial infection in the periodontal tissue (22).the dm alters periodontitis by deregulating the immune and inflammatory responses in the periodontium, further cytokines are accumulated in the gingival tissues which will give rise to further periodontal destruction (23, 24). also, dm effects diminished function of the neutrophils and hyperactivity of macrophages and monocytes which will result in further devastation of the periodontium, thus diabetic patients have greater prevalence and extent of periodontal pockets (25, 26). poor glycemic control, with the associated rising in ages (27), these certainly play a significant role in the susceptibility of diabetic patients to infections and damaging pd. there were augmented bop, augmented tooth mobility and more loss of attachment as the individuals with diabetes are twice as possible to exhibit attachment loss as nondiabetic individuals (28). in the present study, the salivary oc concentrations were higher in the chronic periodontitis with pt2dm group than the chronic periodontitis with wt2dm group, chronic periodontitis group and control groups. this increase may designate an increase in the cellular actions of osteoblasts to reparation the broken alveolar bone (29).in addition, unusual blood glucose control was a risk factor for bone loss. reduced bone mass and augmented fracture rate were communal in diabetes, that attributable to reduce late-stage differentiation of osteoblasts and a decrease in osteoblast function. also, advanced glycated end products (ages) had been associated to abnormal development of osteoblasts, that believed to enhance bone resorption and induce apoptosis .as well as, enzymatic cross-linkage of collagen fibers provided strength to bone, nevertheless ageinduced non-enzymatic collagen cross-linkage caused increasing fracture risk(30). moreover, osteocalcine was a potential marker of abnormal bone turnover in periodontal disease progression. the connotation between diabetes and periodontal diseases was demonstrated. diabetes was a risk factor for periodontal disease, so as the diabetic patients showing an augmented prevalence, extent and severity of gingivitis and periodontitis compared to healthy adults (31).the oc is produced by osteoblasts and is widely accepted as a marker of bone osteoblastic activity. oc, incorporated into the bone matrix, is released into the circulation from the matrix during bone resorption and, hence, is considered a marker of bone turnover, rather than a specific j bagh college dentistry vol. 29(1), march 2017 periodontal health oral and maxillofacial surgery and periodontics 94 marker of bone formation (32).when the values of clinical periodontal parameters increase, this mean increase in the severity of pd, more destruction of alveolar bone, more activity of osteoblast and increase in the oc concentration to repair the damaged alveolar bone(29).as well as, the results gained from this study identified positive significant correlation with the bop, ppd and cal parameters, which may be attributable to presence of further periodontal tissue destruction in diabetic groups that resultant in augmented enzymatic activity with increasing severity of periodontitis. these outcomes can be 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responders to hormone replacement therapy in postmenopausal women. j bone miner res, 1996 nov; 11(11):1784-1792. :الخالصة في العديد من الدراسات .ارتفاع نسبة الكلوكوز لدى المرضى وذات مضاعفات ومثبتة بعالقة ذات اتجاهينداء السكري والتهابات اللثة امراض مزمنة الخلفية: عدم الموازنة في اعادة تنظيم العظم ، التي تزيد قابلية و المناعية االلتهابية والمؤثر في فعالية االوستيوكالست لألمراضالمصابين بداء السكري هو العامل المحفز .االوستيوكالسين هو واحد من بروتينات المصفوفة العظمية االكثر وفرة في العظام والمصنوعة حصرا هناك .تم العثور على قطع التقدم اللتهاب اللثة المزمن في الواقع نواتج التحلل من مصفوفة العظام، الذي يتحرر خارج الخاليا في السائل اللثوي صغيرة من تكسر االوستيوكالسين في مناطق اعادة تشكيل العظام وهي واللعاب بعد تحطيم االنسجة اللثوية خالل االلتهاب اللثوي. لى اربعة مجاميع ( تم تقسيم االشخاص ا35-53) تم اختيار ثمانين شخصا لغرض الدراسة من الذكور واالناث من اصحاب الفئة العمرية الموادوالطرق: مريضا بالسكري من 05مريضا بالسكري من النوع الثاني الغير مسيطر, المجموعة الثانية:تتكون من 05شخص لكل مجموعة( المجموعة االولى :تتكون من 05) اللثة المزمن, المجموعة الرابعة:تتكون مريضا غير المصاب بالسكري, كل منهم لدية مرض ألتهاب 05النوع الثاني المسيطر علية, المجموعة الثالثة:تتكون من مل من عينات اللعاب غير المحفزمن جميع المشاركين في الدراسة ومن ثم وضع العينات في 3شخصا اصحاءواللثة لديهم صحية كمجموعة ضابطة.تم جمع 05من الكيميائي الحيوي لالوستيوكالسين ،ألفا أميليس وتوتل بروتين جهاز الطرد المركزي حيث تم بعدها جمع الخالصة الصافية للعينة وتجميدها الى وقت التحليل عمق جيوب اللثة اللعابية ثم قياس مؤشرات ماحول االسنان السريرية بما في ذلك مؤشر الصفيحة الجرثومية, مؤشر التهاب اللثة, مؤشر النزف عند التسبير, ربعة اسطح في كل سن بأستثناء الرحى الثالثة.ومستوى االنسجة الرابطة سريريا سجلت لكل شخص في الدراسة وال لتسجل باإلضافة.الحيوية الكيميائية والتحليالت للثة السريرية المؤشرات في الضابطة والمجموعة الدراسية المجاميع بين عالية معنوية فروقات وجدت النتائج: مسيطر الغير الثاني النوع السكري بمرض المصابين لدى المزمن اللثة التهاب مجموعة في السريرية االسنان حول لمؤشرات الحسابي للمتوسط قيم اعلى الثاني النوع السكري بمرض المصابين لدى المزمن اللثة التهاب مجموعة في وجد تركيز اعلى بان اظهر اللعابي لالوستيوكالسين الحيوي الكيميائي التحليل.علية والمجموعة المزمن اللثة التهاب مجموعة ثم علية المسيطر الثاني النوع السكري بمرض المصابين لدى المزمن اللثة التهاب مجموعة يليها علية مسيطر الغير االوستيوكالسين مستويات بين الربط عند وموجبة عالية معنوية عالقة اظهر للثة السريرية المؤشرات مع اللعابي االوستيوكالسين مستويات بين الربط. الضابطة جيوب عمق قياس مع سالبة معنوية عالقة وجدت بينما, التسيير عند النزف مؤشر وقياس اللثة التهاب مؤشر وقياس الجرثومية الصفيحة مؤشر قياس مع اللعابي السكري بمرض المصابين لدى المزمن اللثة التهاب مجموعة في سريريا الرابطة االنسجة مستوى قياس مع وموجبة ضعيفة معنوية عالقة توجد ال ،كذلك اللثة الجرثومية الصفيحة مؤشر قياس مع اللعابي االوستيوكالسين مستويات بين الربط عند وموجبة عالية معنوية عالقة اظهر ايضا. علية مسيطر الغير الثاني النوع جيوب عمق قياس مع الربط عند معنوية عالقة توجد ال بينما سريريا، الرابطة االنسجة مستوى قياس و التسيير عند النزف مؤشر وقياس اللثة التهاب مؤشر وقياس مؤشر قياس مع الربط عند وموجبة عالية معنوية عالقة وجدت ، علية المسيطر الثاني النوع السكري بمرض المصابين لدى المزمن اللثة التهاب مجموعة في اللثة اظهر و اللثة جيوب عمق قياس مع الربط عند موجبة متوسطة معنوية عالقة وجود الى ،باإلضافة سريريا الرابطة االنسجة مستوى قياس و التسيير عند النزف المزمن اللثة التهاب مجموعة في اللثة التهاب مؤشر قياس مع الربط عند معنوية عالقة توجد ال بينما, الجرثومية الصفيحة مؤشر قياس مع ضعيفة معنوية عالقة في اللثة التهاب مؤشر وقياس الجرثومية الصفيحة مؤشر قياس مع الربط عند موجبة متوسطة معنوية عالقة وجدت, واخيرا. السكري بداء المصابين لغير الضابطة . المجموعة نسجة اللثة مع ازدياد مستويات االوستيوكالسين من الممكن استنتاج ان المصابين بالسكري من النوع الثاني والغير مسيطر علية يعانون من تدمير اكثر ال االستنتاج: لمؤشر الكيميائي الحياتي اللعابي من المصابين بالسكري من النوع الثاني والمسيطر علية و الغير مصابين بالسكري كل منهم لدية مرض ألتهاب اللثة المزمن و هذا ا ة افضل ومعالجة فعالة المراض اللثة وكذلك معالجة مرض السكري من النوع الثاني.يستخدم لقياس درجة تدمير اللثة, توفر فرصا للتشخيص المبكر ومراقب j bagh college dentistry vol. 29(1), march 2017 periodontal health oral and maxillofacial surgery and periodontics 96 type of the paper (article journal of baghdad college of dentistry vol 34 no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 36 research article natural preparation of rice husk-derived silica and eggshell-derived calcium carbonate composite as a coating material for dental implant rehab aamer kareem 1, ghassan abdul-hamid naji 2,* 1 phd. student, department of prosthodontics, college of dentistry, university of dijlah, baghdad, iraq 2 department of prosthodontics, college of dentistry, university of baghdad, bab-almoadham, p.o. box 1417, baghdad, iraq * correspondence: dr_ghassan74@yahoo.com abstract: background: the world is in front of two emerging problems being scarceness of virgin resources for bioactive materials and the gathering of waste production. employment of the surplus waste in the mainstream production can resolve these problems. the current study aimed to prepare and characterize a natural composite cao-sio2 based bioactive material derived from naturally sustained raw materials. then deposit this innovative novel bioactive coating composite materials overlying yttria-stabilized tetragonal zirconia substrate. materials and method; hen eggshell-derived calcium carbonate and rice husk-derived silica were extracted from natural resources to prepare the composite coating material. the manufactured powder was characterized via fourier-transform infrared spectroscopy (ftir), field emission scanning electron microscope (fesem), x-ray fluorescence (xrf), x-ray diffraction (xrd) and particle size analyzer. the bioactive composite was deposited through radiofrequency (rf) reactive magnetron sputtering overlying disc-shaped samples with a dimension of 10 mm diameter were prepared from partially sintered yttria-stabilized tetragonal zirconia polycrystal (y-tzp). results: the particle size of the rice husk-derived ranged between (480.4 – 606.1) nm with a mean particle diameter of 541 nm. the eggshell derived calcium carbonate powder presented a particle size between (266.4-336) nm and a mean particle diameter of 299.9 nm. the xrd data revealed the crystalline nature and phase composition of the natural prepared calcium carbonate powder and demonstrate the monocrystalline nature of natural sio2. ftir spectrometer showed the emergence of novel spectra separated from the two innovative components. xrf analysis revealed that 99.4% of the rice husk is sio2 while eggshell-derived powder is mainly composed of calcium oxide. fe-sem images of the coated zirconia exhibited average thickness of the natural caco3/sio2 coat layer may reach to12.84 µ. conclusion: the prepared composite derived from natural resource waste is suitable to be utilized as a coating material for ceramic dental implants with promising biological and mechanical properties. keywords: rice husk; silica; eggshell; calcium carbonate; zirconia; coating material. introduction dental implants have been extensively utilized as a supporter for prosthodontic restorations; removable and fixed as well as the maxillofacial restorations, with a high degree of success (1). different types of material were used as an implant; the most common is titanium and its alloy, later zirconia acquired robust interest due to many desirable properties (2). the aforementioned materials; titanium and zirconia regarded as a bioinert biomaterials which necessitate the use of bioactive biomaterial as a coating overlying the bioinert substrate; titanium and zirconia (3). the selection of the bioactive coat depends on physicochemical characteristics in addition to the availability and affordability of the material (4). in recent years, natural biocomposites received widespread attention as an active coating covering metallic implants; due to its bioactivity, availability and affordability (4). micro-nano organizational modification of the surface received date: 2021-10-1 accepted date: 2021-11-3 published date: 15-3-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbcd .v34i1.3090 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3086 https://doi.org/10.26477/jbcd.v34i1.3086 j. bagh. coll. dent. vol. 34, no. 1. 2022 kareem and naji 37 of the implant may improve bone conductivity and hydrophilicity in addition to decreasing the conducted stress (5). calcium oxide/ silicon dioxide built bioceramics have been considered as a probable alternative for artificial bone owing to their excellent biocompatibility and osseoinductivity (6). among these biomaterials, autogenous bone is often employment of by-products or leftover of agricultural operations received a wide consideration in the emerging technologies, scientific pursues and biological scopes in recent years (7). rice husk is an agricultural residue material plentifully available in iraq and all rice-producing countries. rice husk ash is rich in silica and can be used as a source for the manufacturing of silica powder (8). various authors proved that the rice husk ash was an exceptional resource for amorphous silica (9, 10). chicken eggshell agricultural junks represent the environmental pollution problem. the chemical composition of eggshells is composed mainly of calcium carbonate caco3 (10). eggshell is regarded as massive pollution for the environment, at the same time rich source for caco3 and cao, making the opportunity to utilize eggshell as an alternative sustainable source for bioactive osseoconductive material (11). the current study aims to prepare and characterize of a novel naturally prepared calcium carbonate (caco3)/ silica sio2 composite based bioactive implant-coating material. materials and methods preparation of biological silica subsequent to the milling process, the rice husk was sieved by using stainless steel mesh no. 230 and thoroughly washed with deionized water with the aid of mechanical stirring for 1 h then dehydrated by dry heat oven at 70°c. the rice husk was treated with a leaching agent (1 m hydrochloric acid) for 2 h at 90°c to minimize metallic contamination and rinsed with distilled water until reach neutral ph. the achieved mixture was then positioned in a furnace (vita zyrcomat 6000 ms, germany) at 700°c for 2 h in order to accomplish the calcination process. calcinated rice husk ash around 1000 mg was added into 20 ml of 1.5 m sodium hydroxide in a glass beaker for 1 h at 90°c to produce sodium silicate solution (12). sodium silicate was then dissolved in pure ethanol 250 ml, then diluted with 1 l of distilled water for 10 min. the resultant solution was softly titrated with 3 m orthophosphoric acid until the formation of yellowish gel at neutral ph. this gel was washed with warm distilled water in order to remove any remnants of sodium silicate or sodium phosphate followed by centrifugation at speed of 4000 r/min for 15 min. the manufactured gel was then dehydrated at 90 °c for 2 h and calcinated in a furnace (vita zyrcomat 6000 ms, germany) at 550 °c for 30 min to produce silica powder (13). preparation of eggshell-derived caco3 powder fresh chicken eggshells with accompanied internal membranes were firstly crushed in a mortar and pestle to a suitable particle size powder. powder of eggshell with quantity around 100 grams was filtered by sieve no. 35. a ball milling machine was used for milling of the filtered powder with water producing slurry mixture, which was desiccated for 24 h at 105°c to attain fine powder. the dried powder was filtered using no. 230 sieve. quantity powder of 10 grams was soaked in 50% bleaching agent (sodium hypochlorite) for 10 minutes. followed by rinsing the powder with deionized water for 5 times in order to eliminate any bleach deposits. the powder was placed in a hot oven at 105°c for 24 h for drying. the dried powder was more ground by the means of an electrical grinding machine and filtered with no. 230 astm sieve to achieve caco3 (14). j. bagh. coll. dent. vol. 34, no. 1. 2022 kareem and naji 38 characterization of prepared powders the prepared powders; rice husk-derived silica and eggshell-derived calcium carbonate were characterized with fourier-transform infrared spectroscopy (ftir), x-ray diffraction (xrd), x-ray fluorescence (xrf) and particle size analyzer. after the characterization of the silica and calcium carbonate, the two powders were mixed with a mechanical stirrer at an ambient temperature according to the intended ratios (90% caco3 with 10% sio2). the resultant mixture was investigated by powder particle size analyzer x-ray diffraction (xrd), fourier-transform infrared spectroscopy (ftir) and x-ray fluorescence (xrf) in order to determine the composition and concentration of elements preparation of the specimens disc-shaped samples with a dimension of 10 mm. diameter and 2 mm. thickness were prepared from partially sintered yttria-stabilized tetragonal zirconia polycrystal (y-tzp) vita yzht substrate by the means of exocad dental computer aid design/computer aid manufacture (cad/cam), imes icore coritec 250i [12]. the specimens were sintered with vita zyrcomat 6000 ms sintering furnace, 30 specimens with 10 mm diameter (10 specimens for each test) were recruited for x-ray diffraction (xrd) (lab x, xrd 6000, shimadzu, japan), field emission scanning electron microscope (fesem) (inspect f50 fe-sem; netherland), and x-ray fluorescence (xrf) (pan analytical laboratories, tehran, iran). coating procedure weight of 20g of mixture calcium carbonate/silica (90/10 % w) powder was pressed in cylindrical stainless-steel mold using applied force around 30 kg. with (dimension of 51mm diameter and 7mm height. pressing is mechanical process used to reduce the porosity and vacancies between the particles and to produce a disc at 5cm diameter and a 4mm thickness, then the discs were sintered at 900 °c in order to reach sufficient toughness to resist fracture during sputtering (17). the bioactive composite was deposited through radiofrequency (rf) reactive magnetron sputtering utilizing sio2/caco3 as a sputtering target which have a (50 mm) diameter and (4 mm) thickness. the composition of reactive gas is composed of argon as sputtering gas. the base pressure in the vacuum chamber is 1×10−5 torr and the working pressure has been 6×10-3. the distance between the target and substrate was 10 cm and the time of deposition was 20 h at 150°c temperature and at frequency equal to 13.56 mhz (18). physical tests and structural characterization field emission scanning electron microscope (fe-sem) is an important microstructural analysis technique used for observing the characteristics of the compounds (19). in the present work, fe-sem (inspect f50 fe-sem; netherland) with an accelerating voltage of 10–20 kv was used to reveal the microstructure of the experimental biological coat include naturally prepared rice husk-derived silica and eggshell-derived calcium carbonate composite. fe-sem was used to diagnose the phases, distribution of particles as well as to characterize the morphology of the prepared specimens (20). x-ray fluorescence (xrf) data was analyzed to characterize the elemental composition of the coated zirconia substrate (22, 23). the j. bagh. coll. dent. vol. 34, no. 1. 2022 kareem and naji 39 xrf analysis of the coating composition was accomplished at arya electron optic ltd for advanced scientific and industrial equipment, north shiraz ave, tehran, iran. x-ray diffraction (lab x, xrd 6000, shimadzu, japan) had been used to inspect the coated specimens to examine the crystallographic orientation of the coating layer. results the particles size of the manufactured powders was examined by means of laser particle size analyzer. the particle size of the rice husk-derived silica shown in fig. 1(a) ranged between (480.4 – 606.1) nm with mean particle diameter of 541 nm as. the eggshell derived calcium carbonate powder presented a particle size between (266.4 336) nm and a mean particle diameter of 299.9 nm (fig. 1(b)). figure 1: size distribution of (a) rh-sil ica; (b) eggshell-ca cium carbonate the x-ray diffraction pattern of the calcium carbonate reveals sharp and well-defined peaks at 2𝜃 values of 23.2º, 24.9º, 36.1º, 39.6º, 43.2º, 47.6º and 48.6º. however, peaks are also perceived at 2𝜃 values of 31.6º, 57.8º, 61.5º, 65.4º and 73.3º. the xrd pattern in fig.2 demonstrates the monocrystalline nature of natural sio2 which contests with reference no. (01-076-0941). an amorphous peak was recorded at 23º which is in agreement with a study conducted by martinez et al. in 2006 (26). figure 2: xrd of the three powders fig. 2 revealed the diffractograms of the three powders; silica, calcium carbonate and composite (mixed extracted powders). the diffractogram of the composite material exhibits compromised spectra between the silica and calcium carbonate powders. fig. 3(a) illustrate ftir spectra of the rice huskderived silica. the band about ~ 806 cm-1 corresponds to si-o bending vibration (26). while fig. 3(b) shows the ftir spectra of the eggshell-derived calcium carbonate particles. the samples display an extensive absorption peak of co3 ions at ~1795 cm−1, ~1458 cm−1 ~1084 cm−1, ~854 cm−1, and~713 cm−1 which have been itemized to be the common demonstrative features and the crucial styles of vibration of the carbonate ions present in calcium carbonate (25,27). the composite powder spectrometer was established the emergence of novel spectra separated from the two innovative components (caco3 and sio2) as presented in fig. 3(c). j. bagh. coll. dent. vol. 34, no. 1. 2022 kareem and naji 40 a figure 3: ftir analysis of the b (a) rice husk-derived silica; (b) eggshell-derived calcium carbonate; and (c) the composite caco3/sio2 table 1 exhibits the chemical composition of the rice husk-derived powder by means of xrf analysis. results revealed that 99.4% of the prepared powder is sio2 in addition to small amounts of calcium oxide and ferric ions (28). the xrf data of eggshell-derived powder revealed that the main composition is calcium oxide. the composite powder xrd proved that it consists of 90.2% calcium carbonate derived from caco3 with 9.7% of silica. table 1. elemental analysis of the rh-derived, eggshellderived and composite powders the finding of xrf analysis of coated specimen was demonstrated in table 2. the results indicated a great quantity of cao which referred to the presence of caco3, which is the main component of the composite coat (22). the cross-section fe-sem images of the coated zirconia exhibited average thickness of the natural caco3/sio2 coat layer may reach to12.84 µ as shown in fig. 4(c). prepared powder elements concentration (wt.%) sio2 cao mgo p2o5 s k fe n a rh-derived 99.4 0.59 t t eggshellderived 98.2 1.33 0.45 t t t t composite 9.7 88.2 1.0 t* t t j. bagh. coll. dent. vol. 34, no. 1. 2022 kareem and naji 41 table 2: xrf elemental analysis of coated zirconia substrate: discussion the xrd data revealed the crystalline nature and phase composition of the natural prepared calcium carbonate powder. the sharp peaks of the diffractogram indicating high crystallinity of the prepared powder (25) . the xrd analysis of the coated zirconia substrate illustrated in fig. 5. the data acquired from the xrd pattern is identical with the diffractogram of the natural rice husk-derived silica/eggshell-derived caco3 composite powder. ftir spectra exhibited that the band neighboring 1089 cm-1 indicates si-o-si lopsided stretching vibration when the connecting oxygen atom transfers corresponding to the si-si lines directed contrary to their si adjacent lines (27). while ftir spectra of eggshell powder demonstrate features and the crucial styles of vibration of the carbonate ions present in calcium carbonate (25,27). the composite powder spectrometer was established the emergence of novel spectra separated from the two innovative components. xrf data explore the excessive amount of calcium oxide indicating the high percentage of calcium carbonate, which is the main constituent of the eggshell (29). the increased thickness of natural element wt % element ppm sio2 4.255 s 1276 al2o3 0.198 cl 509 fe2o3 n ba 32 cao 45.5 co n na2o 0.121 cr n k2o n cu 17 mgo 0.213 mo n mno 0.013 nb 115 tio2 0.018 ni 14 p2o5 >40% pb 107 loi 3.18 rb 46 so3 3.0972 sr 116 figure 4: fesem images of surface topography of a) uncoated zirconia; b) natural caco3/sio2. and c) fesem cross-section images of natural caco3/sio2 coat layer figure 5: x-ray diffraction spectra of coated zirconia j. bagh. coll. dent. vol. 34, no. 1. 2022 kareem and naji 42 composite may be attributed to the high cohesion bonding between its particles (10). the coating surface microstructure of natural caco3/sio2 on zirconia substrate appear porous as illustrated in the fesem images in fig. 4 a&b. these porosities may have a vital role for enhancing bone regeneration as well as increasing the surface area of the implant surface leading to decreasing the generated stress inside the contiguous bone (3). conclusion recently, byproduct and waste management for the development of new products has gained immense interest. within the limitations of the current study, a biological caco3/sio2 composite was prepared from avian eggshell and rice husk via simple methods to be used as a coating material to the zirconia substrate. therefore, it can be utilized effectively as a coating material for zirconia implants with predictable promising biological and mechanical properties. conflict of interest: none. references 1. micsh c. dental implant prosthetics, elsevier; 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fastner s.; rehman m. a. u.; ferraris s.; perero s.; di confiengo g. & boccaccini r. a. multifunctional stratified composite coatings by electrophoretic deposition and rf co-sputtering for orthopaedic implants.” j. mater. sci., 2021; 56: 7920-7935. 32. maver t.; mastnak t.; mihelič m.; maver u.; finšgar m. clindamycin-based 3d-printed and electrospun coatings for treatment of implant-related infections. mater.. 2021; 14, 54-64. 33. peng c.; izawa t.; zhu l.; kuroda k.; okido m. tailoring surface hydrophilicity property for biomedical 316l and 304 stainless steels: a special perspective on studying osteoconductivity and biocompatibility. acs appl. mater. interfaces, 2019; 11: 45489– 45497. السنيه للزرعات كطالء البيض قشور من المشتقة الكالسيوم وكاربونات , الرز قشور من المشتقة السيليكا مادتي من الطبيعي الخليط تحضيرالعنوان: غسان عبد الحميد ناجي , كريم عامر رحاب الباحثون: المستخلص: اكم المخلفات الطبيعية ذات االضرار البيئية مثال على ذلك الخلفية: مشكلتان عالميتان تلوح في االفق ,االولى تتمثل بشحة مصادر المواد البايولوجية ذات االستخدام الطبي االمن. اما الثانية تر تيجة تولد غازات ثقيلة. مثال اخر يتمثل بقشور البيض مصدر تلوث بيئي كبير وصعوبة التخلص منها. تراكم قشور الشلب الغير صالحة للعلف الحيواني مسببتاً تلوف بيئي عند احتراقها ن لعملية تجديد منهما لعمل مادة طالئية محفزة مواد وطرق العمل: ان هذه الدراسة تهدف الستخالص السيليكا وكاربونات الكالسيوم من قشور الشلب وقشور البيض على التوالي. وتحضير خليط زرعات الزكونيا بطريقة الترذيذ بولسطة المعجل العظم حول الزرعة لتفادي نقص العظم المحيط بالزرعة وفشلها. ومن ثم بعد تحضير المادة واجراء الفحوصات الالزمة يتم استخدامها الكساء الحمراء, الماسح االلكتروني, فلورة االشعة السينية , و مشتت االشعة السينية. تم فحص عشرة عينات لكل المغنطي. تم خالل هذه الدراسة االستعانة بالفحوصات التالية: اشعة فيورير تحت ملم. كذلك تم قياس حجم ذرات كل من المسحوقين المستخلصين. 10فحص من الفحوصات المذكورة آنفاً. كل عينة بشكل قرص بقطر صة من المخلفات الطبيعية يمكن االستفادة منها الكساء غرسات االسنان المصنوعة من مادة الزركونيا بنتائج واعدة االستنتاجات: ان هذه المواد المستخل suhaib f.doc j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry164 photogrammetric analysis of facial soft tissue profile of iraqi adults sample with class i normal occlusion: (a cross sectional study) suhaib m. al-janabi, b.d.s. (1) fakhri a. ali, b.d.s., m.sc. (2) abstarct background: the purposes of this study were to determine the photogrammetric soft tissue facial profile measurements for iraqi adults sample with class i normal occlusion using standardized photographic techniques and to verify the existence of possible gender differences. materials and methods: eighty iraqi adult subjects (40 males and 40 females) with an age ranged between 18-25 years having class i normal occlusion were chosen for this study. each individual was subjected to clinical examination and digital standardized right side photographic records were taken in the natural head position which is mirror position which the patient looking straight into his eyes into the mirror mounted on the stand. the photographs were analyzed using autocad program 2011 to measure the distances and angles used in the soft tissue photogrammetric analysis. descriptive statistics was obtained for the measured variables for both genders and independentsamples t-test was performed to evaluate the genders difference. results and conclusions: the results indicated that: males had greater facial heights and lengths as well as greater prominences. the mean values of all angular variables were higher in males than females except in the following angular measurements: nasofrontal, mentolabial, angle of the middle facial third; and angle of the head position, with larger male dimensions in all linear measurements of the facial, labial, nasal, and chin areas except canut’s nasal prominence in nasal area. the nasofrontal, vertical nasal, nasal dorsum, cervicomental, middle facial third and facial convexity angles showed statistically significant gender differences, in which the male dimensions were larger than females while the nasolabial, the mentolabial, nasal, the inferior facial third, the head position and total facial convexity angles showed statistically non significant gender differences. key words: photogrammetric analysis, soft tissue, class i normal occlusion. (j bagh coll dentistry 2013; 25(2):164-172). introduction soft tissues refer to tissues that connect, support or surround other structures and organs of the body not being bones. soft tissues of the face together with the underlying skeleton define the facial trait of an individual. facial traits are major features in physical appearance, which is well related to social acceptance, psychological well being and self esteem of an individual [1]; therefore, the analysis of the human face is a science and an art, utilizing both aesthetic and anthropologic tools. the shape of the human face depends on both the structure of the hard tissue (bone) and the soft tissue that covers it. the quantitative assessments of the size and the shape of facial soft tissue are widely used in several medical fields such as orthodontics, clinical genetics, and maxillofacial and plastic surgery for diagnosis, effective treatment planning, and postoperative assessment [2] (1) msc student, orthodontic department, college of dentistry, baghdad university. (2) professor, orthodontic department, college of dentistry, baghdad university the appearance of the face, the most variable part of the human body, is influenced by age, sex, race, and ethnicity. obtaining measurements of the soft tissues of the face is important in terms of achieving aesthetic criteria.[3] according to muge et al. [4] , orthodontics has generally led the way in quantitative analysis of the soft tissue facial architecture, developing norms and longitudinal data, important equally to maxillofacial surgeons, plastic surgeons and to clinicians in prosthetic dentistry. all medical specialties interested in improving facial appearance need to measure the face to quantify the desired facial changes [5] it is now apparent that what has been considered beautiful and acceptable as the norm for one culture may be different for another. furthermore, facial measurements are also an integral part of the evaluation of dimorphism. therefore, measurements of facial soft tissue have been made to determine the normal reference values in different populations [1]. facial soft tissue analysis has been conducted using several methods: direct anthropometry, (2d) photogrammetry, and newer three-dimensional (3d) record of methods such as laser surface and, more recently, scanning digital j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry165 3d photogrammetry. photogrammetry has been introduced as an alternative to direct measurements to obtain distances between facial landmarks using both twodimensional and three-dimensional methods. obtaining measurements from photographs is less intrusive to the patient and more cost-effective; it provides a permanent record for the face that can be accessed at a later time [5] two-dimensional photogrammetry has been used for evaluating the soft tissues in orthodontic treatment. the method was shown to be sufficiently reproducible since it was simple to achieve in a conventional setting, without the need for special equipment [4]. nowadays there are many conflicts about the hazard of radiology that is why the present study focused on use of photometry over cephalometry by means of objective methods studying the facial analysis. in addition, the soft tissue assessment gets priority over hard tissue assessment in that a photograph accurately posturizes how a face actually looks, which is superior to a cephalogram which gives only facial outline. thus it was felt necessary to do photographic analysis. materials and methods the sample out of 200 clinically examined subjects, only 80 subjects (40 females and 40 males fulfilled the inclusion criteria the sample include undergraduate students from the college of dentistry, university of baghdad. all of them were iraqis arabs with an age range between (18-25) years. according to arnett et al., kalhaet al. [6], usalet al. [7], lalitha and kumer [8], kadhom [9]; the following criteria were used in the selection of the total sample: 1. full permanent dentition regardless the third molars. 2. no history of previous orthodontic treatment. 3. no history of facial trauma or craniofacial disorder, such as cleft palate. 4. class i occlusion with normal overjet and overbite (2-4 mm). 5. bilateral class i buccal segments "molar and canine" [10]. 6. skeletal class i relationship determined clinically by the two fingers method [11]. 7. minor or no spacing or crowding [12]. 8. class i incisor classification [13]. the method each individual was seated on a dental chair and asked information about name, age, origin, history of facial trauma and previous orthodontic treatment. clinical examination 1. assessment of the anteroposterior skeletal relationships 2. assessment of the dental relationship 3. measurement of the overjet 4. measurement of the overbite. standardization of the photograph photographic set-up: the photographic setup consisted of a tripod supporting a digital camera with a primary flash and a 100 mm macro lens. the 100 mm macro lens was chosen to avoid facial deformations [15]. the tripod controlled the stability and the correct height of the camera according to the subject’s body height, so that adjustment of the tripod height allowed the optical axis of the lens to be maintained in a horizontal position during the recording; this was adapted to each subject’s body height. the blue background, 0.95 m width and 1.10 m length was made of a piece of cloth [16]. a primary flash was attached to the tripod by a lateral arm, at a distance of 27 cm from the optical axis of the camera and 75 degrees from the upper right angle to avoid the red eye effect on the photographs. another element of the set-up was a secondary flash placed behind the subject and its function was to light the background and eliminate undesirable shadows from the contours of the facial profile [15].a slave cell allowed synchronization with the main flash [14] record-taking the camera was used in its manual position; the shutter speed was 1/125 per second, and the opening of the aperture f/2.8 [15]. in a standing position, each subject was asked to relax, with both arms hanging freely beside the trunk. the subject was positioned on a line marked on the floor and a vertical measurement scale divided into millimeters allowed measurements at life size (1:1) was placed behind the subject[14]a plumb line, suspending a 0.5 kg weight hung from the scale, held by a thick black thread to define the vertical plane, true vertical line (tvl), on the photographs and 120 cm in front of the subject, on the opposite side of the scale was a mirror, the center of the camera lens was kept at approximately110 cm away from the j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry166 subject, this distance was standardized to obtain sharp image [15]. in order to take records in natural head posture, the subjects were positioned on a line marked on the floor and were asked to stand in relaxed position and to look straight into the mirror at the eye level, with teeth occluded and lips relaxed [5]. standardized right side profile records were taken with the patient in the nhp according to moorrees and kean [17], vaizis[18], and lundström and lundström[19]. previously, glasses were removed and operator ensured that subjects’ forehead, neck and ears were clearly visible during recording. definition of soft tissue landmarks: -fernández: according to a. facial landmarks riveiro et al.[15]. 1. point prn (pronasale or nasal tip): the most prominent point of the tip of the nose. 2. point g' (glabella): the most anterior point of the middle line of the forehead. 3. point n' (nasion soft tissue): the point of deepest concavity of the soft tissue contour of the root of the nose 4. point sn (subnasale): the point where the lower border of the nose meets the outer contour of the upper lip 5. point cm (columella): the most anterior point on the columella of the nose. 6. point pog' (soft tissue pogonion): the most prominent point on the soft tissue contour of the chin. 7. point li (labiale inferior): the point that indicates the mucocutaneous limit of the lower lip 8. point ls (labiale superior): the point that indicates the mucocutaneous limit of the upper lip 9. point me'(menton soft tissue): the most inferior point of the inferior edge of the chin. 10. point c' (cervical): the intersection of lines tangent to neck and throat. 11. point tri (trichion): the sagittal midpoint of the forehead that borders the hairline. 12. point mn' (mid nasal): a pronounced convexity of the dorsal profile of the nose 13. pointtrg (tragus): the most posterior point of the auricular tragus. 14. point sm (supramentale): the point of greatest concavity in the midline of the lower lip between labraleinferius and menton. 15. pointstomion superior (sts), the most inferior point of the upper lip. 16. pointstomion inferior (sti), the most superior point of the lower lip. 17. superior point of the tvl (stv). 18. inferior point of the tvl (i tv). b. facial planes and lines: according to fernández-riveiroet al.[15]. 1. true vertical line (tvl): the line was placed through soft tissue nasion and was perpendicular to the true horizontal line. 2. true horizontal line (thl): the line was placed through soft tissue tragus and was perpendicular to the true vertical line. 3. g'sn line: the line between points glabella and subnasale 4. sn-columella line: the line between points subnasale and the most anterior point on the columella of the nose. 5. snls line: the line between points subnasale and the median point in the upper margin of the upper membranous lip. 6. snpog' line: the line between points subnasale and soft tissue pogonion 7. g'-n' line: the line between points glabella and soft tissue nasion. 8. n'-prn line: the line between points soft tissue nasion and the tip of the nose. 9. n'-mn line: the line between points soft tissue nasion and mid nasal. 10. li-sm line: the line between point labiale inferior and supramentale. 11. sm-pog' line: the line between points supramentale and soft tissue pogonion. 12. c-me' line: the line between points cervical and soft tissue menton. 13. g'-pog'line: the line between points glabella and soft tissue pogonion. 14. n'-trag line: the line between points soft tissue nasion and tragus. 15. trag-sn line: the line between points tragus and subnasale. 16. trag-me' line: the line between points tragus and soft tissue menton. 17. sn-sm line (canut’s line): the line between points subnasale and supramentale. 18. g'-prn line: the line between points glabella and tip of the nose. 19. prn-pog' line: the line between points tip of the nose and soft tissue pogonion. j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry167 20. n'-pog' line:the line between points soft tissue nasion and soft tissue pogonion. 21. mn-prn line: the line between points mid nasal and the tip of the nose. facial measurements: a. angular measurements: according to fernández-riveiroet al.[5]; milosevic et al.[2]; malkoçet al.[14]. 1. g'–n'–prn-: the angle between g'-n' line and n'-prn line. 2. cm–sn/n'–prn: the angle between cm-sn line and n'-prn line 3. n'–prn/tv (n): the angle between n'-prn line and true vertical line at soft tissue nasion. 4. n'–mn–prn: the angle between n'-mn line and mn-prn line 5. cm–sn–ls: the angle between cm-sn line and sn-ls line 6. li–sm–pog': the angle between li-sm line and sm-pog' line 7. c–me'/g'–pog': the angle between c-me' line and g'-pog'line 8. n'–trag–sn: the angle between n'-trag line and trag-sn line 9. sn–trag–me': the angle between trag-sn line and trag-me' line 10. sn–sm/th: the angle between sn-sm line and true horizontal line. 11. g'–sn–pog': the angle between g'-sn line and sn-pog' line. 12. g'–prn–pog': the angle between g'-prn line and prn-pog'line. b. linear measurements: according to fernández-riveiroet al.[15].the reference lines were: 1) tv through n. 2) th through trg. 1.vertical linear measurements (parallel to tv line): 1. upper facial third, tri-g' 2. middle facial third, g'-sn 3. lower facial third, sn-me' 4. nasal length, n'-sn 5. length of upper lip, sn-sts 6. length of lower lip, sti-sm 7. height of chin, sm-me' 8. height of nasal tip, sn-prn 2. linear horizontal measurements (parallel to th line): 1. facial depth, trg-sn 2. nasal prominence, prn /tv (n) 3. subnasal depth, sn /tv (n) 4. mentolabial depth, sm /tv (n) 5. prominence of upper lip, ls /tv (n) 6. prominence of lower lip, li /tv (n) 7. prominence of chin, pg /tv (n). 3. canut’s linear measurements (perpendicular to sn-sm line). 1. canut’s nasal prominence, prn/ sn-sm. 2. canut’s prominence of pogonion, pg/sn-sm. results descriptive statistics and gender differences of facial analysis: the mean values of all measured variables are higher in males than females. independent sample ttest indicated that there is a very highly significant gender difference (fig.1). descriptive statistics and gender differences of nose analysis generally, the mean values of all measured variables are higher in males than females with a very highly significant difference between genders in nasal length, n-sn; nasal prominence, prn /tv (n) and subnasal depth, sn /tv (n). but there is highly significant difference between genders inheight of nasal tip; sn-prn. on the other hand, the canut’s nasal prominence; prn/sn-sm shows nonsignificant difference between genders (fig.2). descriptive statistics and gender differences of the lip analysis the males show higher mean values than females with a very highly significant difference between genders in all measured variables, whereas there is highly significant difference between genders in prominence of upper lip, (fig.3). descriptive statistics and gender differences of the chin area the mean values of all measured variables are higher in males than females with a very highly significant difference between genders in the height of chin sm-meand canut’s prominence of pogonion; pg/sn-sm. while there is a highly significant difference regarding the prominence of j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry168 chin; pg /tv (n). on the other hand, there is a significant difference between genders in the mentolabial depth; sm/tv(n) (fig.4) descriptive statistics and gender differences of angular measurements the mean values of all measured variables are higher in males than females except for the following angular measurements: g–n–prn, nasofrontal angle; li–sm–pg, mentolabial angle; n–t–sn, angle of the medium facial third; and sn– sm/th, angle of the head position, so that females are higher than males in these variables. (fig.5) descriptive statistics and gender differences of the facial convexity the mean values for the measured variables are higher in males than females and according to independent sample t-test there is highly significant difference between genders in g–sn–pg, angle of facial convexity, while g–prn–pg, angle of total facial convexity shows non significant difference between genders. (fig.6) discussion one of the primary goals of orthodontic treatment is to attain and preserve optimal facial attractiveness. beautiful faces are largely a subconscious, unstructured decision. however, for professional orthodontists, esthetic decision making should involve a conscious, well structured thought process. for this reason, a scientific and quantitative study of craniofacial morphology is pre-eminently important to orthodontists, the general observation in the present study was to search about facts of facial esthetics. this study was the first study established in iraq as a photogrammetric study in natural head position method and this analysis was the first time used; so there was no comparison with other previous iraqi studies except a little comparison in soft tissue analysis and little researches in the world were compared with this study. the sample in this study was selected at age between (18-25) years because the individuals maintain the same facial pattern till 25 years [20] and to minimize the effect of any remaining skeletal growth since the majority of facial growth is usually completed by 16-17 years of age [21]. the sexual differences are due to the influence of the sex hormones on the facial contour, which becomes a very evident by adolescence. the male bony structure is bolder, more prominent, with dominance of the forehead, nose, and chin and stronger contour of the mandible [22]. this comes with the general trend of males having greater measurements than females, this is because males have longer growth period than females.[23,24]. the present study evaluated the photogrammetric linear and angular variables that define the soft tissue facial profile of iraqi arab adult sample with standardized photogrammetric records taken in nhp. several authors have also used nhp in their studies fernández-riveiro et al.[15, 5]; milosevic et al.,[2];malkoç et al.[14]. photogrammetric analysis of the soft tissue facial profile an understanding of the facial soft tissues and their normal ranges enables a treatment plan to be formulated to normalize the facial traits for a given individual. photogrammetric analysis of linear measurements the findings of photogrammetric analysis of linear measurements are discussed under the four headings of the facial soft tissue analysis. in each group, comparisons are drawn and analyzed between the male and female samples and in comparison with the other studies. all the linear measurements of young adult males were higher than that of young adult females. this comes in line with nasir [25] who found out that females have smaller measurements than males in all dimensions. in general, males have larger faces, with greater facial heights; longer nasal, labial, and chin lengths; larger nasal, labial, and chin prominences; and a greater nasal and facial depth in the tragus point; this comes in line with fernándezriveiro et al.[15]. the mean values of (upper facial third; tri-g, middle facial third; g-sn, lower facial third; snme) measured are higher in males than females. independent sample t-test indicated that there is very highly significant difference between genders of facial analysis; this reflects that the males tend to have greater facial dimensions than females, this comes in agreement with fernández-riveiro et al. [15], except in the upper facial third; tri-g, who found statistically non significant gender differences for upper facial third, this may be either due to difference in ethnic factor or difference in sample size. j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry169 photogrammetric analysis of angular measurements the nasofrontal angle (g – n – prn): demonstrates very highly significant gender difference with wider angle in females than males, this may indicate a more flattening of females forehead than males ; this may be due to the more posterior position of point n' in males than females or due to more anterior position of prn point and /or g' point in males than females; this comes in agreement with fernández-riveiro et al.[5] :milosevic et al [2]; malkoç et al. [14] ,who found gender differences in this angle. vertical nasal (nprn/tv) angle showed statistically significant gender differences; it was wider in males than in females; this may be due to the more anterior position of prn point and this comes in agreement with fernández-riveiro et al.[5]; malkoç et al.[14] ; this may reflect larger or prominent noses of the iraqi group. nasal dorsum (n – mn – prn) angle also showed statistically significant gender differences with wider angles in males than in females. this may be due to the more anterior position of mn point or may be due to the more posterior position of point n' in males than females and this comes in agreement with fernández-riveiroet al.[5]; malkoç et al.[14] who found that there was statistically significant gender differences. cervicomental angle (c-me/gpg) was more acute in females than in males and showed highly significant difference between genders; this may be due to the more prominence of glabella point in males than females. angles of the facial third: the middle and lower facial thirds were evaluated by the (n – trg – sn) and (sn – trg – me) angles respectively. the nasolabial angle (cm – sn – ls): showed statistically non significant gender differences, but the mean values were higher in males than females (more acute in females) that may be due to a slight more proclination of the upper anterior teeth in females than males as kadhom [9] pointed out. the mentolabial angle (lismpg') was wider in females than in males which means a more rounded border of females chin area and more acute in males, but showed statistically non significant gender differences. generally, the males have forward position of (point pg') and (pointli) in comparison with females, so this may be the major cause to the more acute angle in males than females; this finding comes in agreement with fernández-riveiro et al. [5] while disagrees with milosevic et al [2]; malkoç et al.[14]. who found highly significant gender differences in this angle. the nasal angle (cm – sn/n – prn): showed statistically non significant gender differences, the mean value was higher in males than females (wider in males than females) that may be due to more nasal length, n-sn in males; this comes in agreement with malkoç et al.[14]and disagrees with fernández-riveiroet al.[5]; milosevic et al.[2], who reported considerable gender differences in this angle; this may be attributed to the ethnic factor or sample size. angle of the head position: the lower profile orientation was analyzed by the line sn – sm with the true horizontal line or angle of the head position (sn – sm/th) with slightly larger angle in females than males that may be due to a more posterior position of sn point in females than males, but gender differences were non significant. the angle of facial convexity (g–sn–pg) and the angle of total facial convexity (g–prn–pg) showed that the mean values were higher in males than females; this may indicate that males have less convex soft tissue facial profile than females; this could be related to the larger chin in males that may be due to a more anterior position of soft tissue pogonion resulting in less convex (more concave) facial profile in males than the females and also may be due to the mandibular growth rotation (direction of mandibular growth in males). independent sample t-test indicated that there is highly significant difference between genders in g– sn–pg, angle of facial convexity; this finding disagrees with fernández-riveiro et al.[5],milosevic et al.[2]; malkoç et al.[14]. on the other hand, g–prn–pg, angle of total facial convexity showed non significant difference between genders, this comes in agreement with fernández-riveiro et al.[5]; milosevic et al.[2]; malkoç et al.[14]. facial depth (trg-sn) was also shown to be significantly larger in males than in females. independent sample t-test indicated that there is a very highly significant difference between genders of facial depth; this may be due to a more posterior position of trg point or may be the more anteriorly position of sn point; this comes in agreement with fernández-riveiroet al.[15], but in the present study the facial depth is greater in comparison with fernández-riveiroet al[15].this may be due to ethnic factor or may be due to size of the sample. j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry170 on analyzing the nose, it was observed that males had greater nasal length (n-sn), nasal prominence (prn/tv) and subnasal depth sn /tv (n) than females with statistically very highly significant differences. the height of the nasal tip (sn-prn) also was the nasal measurement that showed highly significant difference between genders. the cantu’s nasal prominence prn/sn-sm was the only nasal measurement that showed non significant gender difference, this result differs from that of fernández-riveiro et al.[5],who found that prn/sn-sm has statistically significant difference between genders; this may be either attributed to difference in ethnic factors or the size of the sample; these may reflect larger noses of the iraqi group that may reflect the inherent need of the iraqi subject for wider nasal passages to accommodate the hot climate(for better evaporation and cooling of nasal air passages). the sn point with regard to the tv in n' (sn/tv through n') was more prominent in males; this may be due to a more anterior position of sn point in males than in females; this comes in agreement with fernández-riveiro et al. [15],in nasal length, prominence and subnasal point with regard to the tv in n' (sn/tv through n') who found statistically significant differences between genders and disagrees with fernández-riveiro et al.[15] in height of the nasal tip (sn-prn) the males showed higher mean values than females with a very highly significant difference between genders regarding length of upper and lower lips (sn-sts and sti-sm) in addition to prominence of lower lip and there is a highly significant difference between genders in prominence of upper lip, this may indicate that the males have thicker and longer lips than females that may reflect the feminine and masculine characteristic features, this comes in agreement with fernández-riveiro et al [15]. in this study, all measurements of the analysis in the area of the chin showed gender differences characterized by greater length and greater prominence in males than in females. this comes in agreement with fernández-riveiro et al.[15] who found that there was a significant difference between genders; this comes with the general trend that the males have larger dimension than females. references 1. senem to, daniz ds, ilker e, cankur ns. soft tissue analysis of healthy turkish young adults: anthropometric measurement. aesthetic plast surg 2009; 33(2):175-84. 2. milosevic sa, varga ml, šlaj m. analysis of the soft tissue facial profile by means of angular measurements. eur j orthod 2008; 30(2):135-40 3. sforza c, dimaggio fr, dellavia c, grandi g, ferrario vf. two-dimensional vs three-dimensional assessment of soft tissue facial profile: a non invasive study in 6year-old healthy children. minerva stomatol 2007; 56(5): 253–65. 4. muge a, demet k, ilken k. reliability of reference distances used in photogrammetry. angle orthod 2010; 80(4):670-7. 5. fernández-riveiro p, smyth-chamosa e, suárezquintanilla d, suárezcunqueiro m. angular photogrammetric analysis of the soft tissue facial profile. eur j orthod 2003; 25(3): 393-9. 6. kalha as, latif a, govardhanc sn. soft tissue cephalometric norms in a south indian ethnic population. am j orthod dentofac orthop 2008; 133(6): 876-81. 7. uysal t, yagci a, basciftci fa, sisman y. standards of soft tissue arnett analysis for surgical planning in turkish adults. eur j orthod 2009; 31(4): 449-56. 8. lalitha ch, kumar kgg. assessment of arnett soft tissue cephalometric norms in indian (andhra) population. the orthod cyber j 2010. 9. kadhom zm. soft tissue cephalometric norms for a sample of iraqi adults with class i normal occlusion in natural head position. master thesis. college of dentistry, university of baghdad, 2010. 10. houston wj. the analysis of errors in orthodontic measurements. am j orthod 1983; 83(5): 382-90. 11. foster td. a textbook of orthodontics. 2nd ed. oxford: blackwell scientific publications; 1985. 12. ishikawa h, nakamura s, iwasaki h, kitazawa s, tsukada h, sato y. dentoalveolar compensation related to variations in sagittal jaw relationships. angle orthod 1999; 69(6): 534-8 13. british standard institution. glossary of dental term (bs4492). london: bsi, 1983. [cited by: jones ml, oliver rg. w&h orthodontic notes. 6th ed. oxford: wright; 2000. p.62 14. milosevic sa, varga ml, šlaj m. analysis of the soft tissue facial profile by means of angular measurements. eur j of orthod 2008; 30(2):135-40 15. fernández-riveiro p, quintanilla ds, chamosa es, cunqueiro mf. analysis of soft tissue facial profile am j orthod dentofac orthop 2002; 122(1): 59-66. 16. meneghini f. clinical facial analysis. 1st ed. springerverlag berlin heidelberg; 2005. p.16-17. 17. moorrees cf, kean mr. natural head position, a basic consideration in the interpretation of cephalometric radiographs. am j phys anthropol 1958; 16(2): 213-34. 18. vaizis ad. a cephalometric analysis based on natural head position. j clin orthod 1991: 3; 172-81. 19. lundström a, lundström f. natural head position as a basis for cephalometric analysis. am j orthod dentofac orthop 1992; 101(3): 244-7. j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry171 20. bishara se, jakobsen jr, hession tj, treder je. soft tissue profile changes from 5 to 45 years of age. am j orthod 1998; 114(6): 698-706. 21. jones ml, oliver rg. w&h orthodontic notes. 6th ed. oxford: wright; 2000. 22. powell n, humphreys b. proportion of esthetic face. thieme: new york; 1984. p.38. 23. trenouth mj, davies ph, johnson js. a statistical comparison of three sets of normative data from which to derive standard for craniofacial measurements. eur j orthod 1985; 7(3): 193-200. 24. genecov js, sinclair pm, dechow pc. development of the nose and soft tissue profile. angle orthod 1990; 60(3): 191-8. 25. nasir dj. facial proportions and harmony of young adult sample. master thesis. college of dentistry, university of baghdad, 1996. figure 1: descriptive statistics and gender differences of facial analysis figure 2: descriptive statistics and gender differences of nose analysis figure 3: descriptive statistics and gender differences of the lip analysis figure 4: descriptive statistics and gender differences of the chin area j bagh college dentistry vol. 25(2), june 2013 photogrammetric analysis orthodontics, pedodontics and preventive dentistry172 figure 5: descriptive statistics and gender differences of angular measurements figure 6: descriptive statistics and gender differences of the facial convexity eman f.doc j bagh college dentistry vol. 25(4), december 2013 oral health status 100pedodontics, orthodontics and preventive dentistry oral health status, dental knowledge and behaviors among children and adolescents (8-15) years old in the cities of baghdad and thamar eman k. chaloob, b.d.s., m.sc. (1) abstract background: investigating dental health knowledge among children is important. knowing what behaviors are right in relation to dental health does not guarantee that children will practice those behaviors. however, lack of knowledge and misconceptions about dental health may lead to behaviors that are harmful to teeth and gum. baseline data on knowledge levels are required to determine which particular areas of dental health education are in need of improvement for high-risk children living in different geographical areas. this research was conducted to study the oral health status, dental knowledge and behavior in relation to two different cities, among children in baghdad and thamar (republic of yemen) governorate. materials and methods: the sample collected was composed of two geographically different groups, first group from baghdad city: composed of 144 children and adolescents and the second group collected from the city of thamar (republic of yemen) composed of 108 of an age range 8-15 years old children. dental plaque and gingival health condition was assessed by using plaque index of silness and loe (1964),and gingival index of loe and silness (1963), ramfjord index teeth were examined to represent the whole dentition. oral examination was performed by a single examiner using mouth mirror and dental explorer for each child. ten questions were fabricated to evaluate the dental health knowledge and behavior of the two groups. results: this study was recorded that the age group 12-15 years old the significant difference was found in relation to gingival health condition, the dental knowledge and behaviors was the highly significant difference was found between baghdad and thamar group. as well as highly scores of dental knowledge and behavior was significantly related to the dental plaque for both baghdad and thamar group. conclusion: the difference in the geographical location could affect on oral hygiene, dental health knowledge and behavior of the children and adolescent. keywords: oral health status, geographical location, dental knowledge. (j bagh coll dentistry 2013; 25(4):100-103). introduction oral health is a significant problem, which is the most common disease of childhood, it is one of the most prevalent infectious diseases, it begins soon after teeth erupt, and affected by age, culture, genetic and biological factors, social and physical environment, health behaviors, dental and medical care all these factors can help to change or improve oral health (1, 2, 3). oral health is an integral part of overall health status as well as the oral diseases are the most prevalent of all health problems, as efforts continue to improve the health of all citizens, oral health could not be overlooked (4).the level of dental knowledge, ethnicity, deprivation, and education, and the lifestyle and diet choices, all together could affect the oral health (5, 6).so that to provide guidance for a public health intervention we should deal with understanding cultural issues surrounding children's oral health (7). race/ethnicity is a marker for oral health status underlying cultural beliefs and practices influence the condition of the teeth and mouth, through diet, care-seeking behaviors, or use of home remedies, it is important to note that among and within all racial/ethnic groups there are substantial differ (1)lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. ences in beliefs and behaviors, which can lead to varying health status. such differences are often associated with demographic characteristics (8, 9). populations have different health experiences and patterns of service use due to socio-cultural differences. research on poor health outcomes generally examines deterrents such as high cost, lack of insurance and availability of services, often aspects of cultural ideas and health practices are suggested as additional deterrents (10). health is a basic human right and oral health is a significant component of general health, as well as the oral health problems are mostly not life threatening, but they are important because of effect on the quality of life. these will make the attention to oral health care (11). knowledge, beliefs and attitudes that students acquire during school can influence their behavior towards not just their own health, but also towards health in their immediate environment (12) dental health problems could be related to many other factors like social, cultural and environment, from this point of view this study was conducted in order to identify if there is a difference in the oral health status and dental knowledge and behaviors according to two different arabic cities. j bagh college dentistry vol. 25(4), december 2013 oral health status 101pedodontics, orthodontics and preventive dentistry materials and methods the sample of this study was composed of two groups, the first group was conducted in baghdad governorate in republic of iraq, and second group was collected in the city of thamar governorate in republic of yemen, the first group composed of 144, second group composed of 108 with an age range 8-15 years old children and adolescents for both group. these two groups were selected from different schools in different area in the baghdad city as well as the sample of yemen was selected from different schools in different area of thamar city. oral examination was performed by a single examiner using mouth mirror and dental explorer for each subject. dental plaque was assessed by using plaque index (pli) (13). gingival health condition was assessed by gingival index (gi) (14). the teeth were examined to represent the whole dentition by using ramfjord index teeth (15). the examination of the children in the sitting and light position was done according to the criteria of who (16). finally ten questions fabricated for the evaluation of dental knowledge and behaviors of the children, questions that related to dental knowledge and behavior was: 1. do you use tooth brush with tooth paste? 2. should we brush teeth at least twice per day? 3. what is the number of deciduous teeth? 4. what is the number of permanent teeth? 5. should we drink milk to reduce dental caries? 6. sweet will or will not cause dental caries? 7. do you visit the dentist regularly? 8. is caries progression leads to losing teeth? 9. is early loosing teeth lead to disharmony of teeth arrangement? 10. do you think that good oral hygiene can lead to healthy teeth and gum? the answer of these questions either yes or i don’t know .the correct answer was yes and take score 1 for each question, for questions 3 and 4 the answer was giving correct number of deciduous or permanent teeth. so that the total maximum score was 10, it means that the entire question was correctly answered. zero score was recorded when the answer was i don’t know. statistical analysis was done using spss computer software (statistical package for social sciences) using t-test, z-proportion. results the sample of this study was composed of two groups divided according to the geographical area b represents baghdad city and th represent thamar governorate in the city of yemen, the sample are subdivided according to age and gender. according to age the sample distributed in to two age groups 8-11 and 12-15, distribution illustrates in table (1). table (2) demonstrates the mean and standard deviation of pli and gi in relation to area location and age group. the significant at age group 12-15 years old according to gi was significant to the area location (p<0.05), as we can see the significant was found at all age group according to the gi. table (3) illustrates the number of children that the answers was positive according to question type in relation to area of baghdad and thamar, the significant was found in question seven and nine (p<0.05),and the highly significant was found (p <0.01) in question 1,2,3,4,5,6,8 and 10. table (4) shows that the children take ten scores was highly significant in relation to geographical area, while the children take zero was significant in relation to geographical area. discussion in this study the significant in the age group 12-15 was found could be related to that this age group was the pubertal so that the several hormonal changes could occur. several epidemiological studies revealed that the periodontal disease is wide spread in children and may vary from community to another (16). other studies have been reached different result by other investigator (15-18).it is important to say that this study found that the calculus was absent in these two group of children present in baghdad and thamar area this result agree with other studies (17,19), and disagree with al-azawi (20). the data of the present study revealed that the dental knowledge and behavior of the children was highly significant related to the geographical area, this could be due to the different believes and habit in their country. several past study compare that the dental knowledge and behavior could differ according to geographical or socially level of the area (1723). in the present study the result shows that the zero score of dental knowledge shows the significant relation according to area location, as well as in the degree of highly scores of dental knowledge the significant was high according to area location. this result could be related to the knowledge about dentistry cannot collected easily, so the children for example doesn't know the number of deciduous teeth and this may be related to other factors like the different social level in the same geographical area. while according to mean plaque, the significant was not found, but in case of score ten the significant was found, this may be due to that j bagh college dentistry vol. 25(4), december 2013 oral health status 102pedodontics, orthodontics and preventive dentistry the children with the zero score doesn't have any interest or knowledge about cleaning their teeth in contrast to the children of score ten were they could have a dental knowledge to take care to their teeth and oral hygiene. several previous studies found that dental knowledge effected on the oral hygiene (19, 20), and some other study found that the dental knowledge and behavior does not affected the oral hygiene (24, 25). references 1. davidsont. fluoridation of drinking water to prevent dental caries. j am 2000; 23(10):12. 2. susan a. fisher-wens, influences on children's oral health: pediatrics 2007; 120(3): 510-20. 3. broder h, reisine s, johnson r. role of africanamerican fathers in child-rearing and oral health practices in an inner city environment-a brief communication. j public health dent 2006; 66(2):138-43. 4. green bl, person s, crowther m, frison s, shipp m, lee p, martin m. demographic and geographic variations of oral health among african americans based on nhanes iii. community dent health 2003; 20(2):117-22. 5. mattson l, goldberg p. gingival inflammatory reaction in children at different ages. j clin periodontol 1995; 12: 98-101. 6. niki f, andrew j. oral hygiene and systemic diseases, health professionals. j dental res 2012; 12: 5. 7. riedy ca, weinstein p, milgrom p, bruss m. an ethnographic study for understanding children's oral health in a multicultural community. department of dental public health sciences, university of washington, seattle 98195-7475, usa. int dent j 200; 51(4): 305-12. 8. flores g, vega lr: barriers to health care access for latino children: a review. fam med 1998; 30(3):196205. 9. aguiree-molina mmc, zambraa re. health issues in the latino community, 2001. 10. kiyak ha. age and culture: influences on oral health behaviour. int dent j 1993; 43(1): 9-16. 11. mautsch w, sheiham a. promoting oral health in deprived communities. 1995. pp.68-73. 12. bojana d, svjetlana j, dragan i, ivana g. oral health assessment among dental students. stomatološki glasnik srbije 2012; 59(3): 1417.(ivsl) 13. silness j. loe h. periodontal disease in pregnancy ii correlation between oral hygiene and pd condition. acta odontol scand 1964; 22: 121-5. 14. loe h, silness j. periodontal disease in pregnancy i prevalence and severity. acta odontol scand 1963; 21: 533-51 15. ramfjord sp. indices for prevalence and incidence of periodontal disease. j periodontal 1959: 30: 51-9 16. world health organization. oral health surveys, basic methods.3rd. geneva: who; 1997 17. al-sayyab m. oral health status among 15 years old school children in the central region of iraq. a master thesis, college of dentistry university of baghdad, 1989. 18. al-alousi w, al-sayyab m. plaque, gingival condition and brushing behavior in 15 year old iraqi school children in central region of iraq. iraqi dent j 1996; 8(1):127-37. 19. al-eissa dty. oral health status of preschool children aged 3-5 years old and its relation to their socioeconomic status and parental dental knowledge, behavior and attitude in two different social areas in baghdad city. a master thesis, college of dentistry, university of baghdad, 2004. 20. al-azawi l. oral health status and treatment needs among iraqi 5 years old kindergarten children and 15 years old students (national survey). phd. thesis. college of dentistry, university of baghdad, 2000. 21. al-sayyab m. periodontal treatment needs among iraqi children living in two iraqi villages (sheha and al-buetha). college of dentistry, 1998; 2: 219-224. 22. kamsarco ty, al-naimi rj, al-muktar bs. the effect of social class on periodontal condition and treatment needs of 13-15 year old students in mosul city –ninevah: iraq. al-rafidain dent j 2001; 1: 7885. 23. yogita b, jane w, judith b. oral health-related cultural beliefs for four racial/ethnic groups: assessment of the literature. bmc oral health, 2008; 8(1): 26. (ivsl) 24. rayant ga. relationship between dental knowledge and tooth cleaning behavior. community dent oral epidemiol 1979; 7:191-4. 25. chu ch, fung dsh, lo ecm. dental caries status of preschool children in hong kong. br dent j 2000; 187(11): 1-10. table 1: the distribution of the two sample according to age and gender age area male female both no. % no. % no. % 8-11 b 40 44.4 50 55.6 90 62.5 th 37 54.4 31 45.6 68 62.9 12-15 b 25 46.3 29 53.7 54 37.5 th 18 45.0 22 55.0 40 37.0 total b 65 45.1 79 54.9 144 100 th 55 50.9 53 49.1 108 100 j bagh college dentistry vol. 25(4), december 2013 oral health status 103pedodontics, orthodontics and preventive dentistry table 2: the mean and standard deviation of the pli and gi in relation to area location according to age age area pli t-test gi t-test mean ±sd mean ± sd 8-11 b 1.286 0.160 0.596 ns p=0.34 0.755 0.559 0.011 ns p=0.99 th 1.405 0.590 0.823 0.548 12-15 b 1.453 0.414 0.501 ns p=0.617 3.470 1.203 2.244 s p=0.031 th 1.453 0.516 0.895 0.498 total b 1.322 0.401 0.016 ns p=0.998 1.562 0.333 2.233 s p=0.039 th 1.321 0.522 0.732 0.922 s=significant, ns=not significant. table 3: the distribution of total sample according to the dental knowledge and behavior (positive answers) in relation to geographical area s=significant, hs=highly significant. table 4: the distribution of children and adolescents according to zero and ten scores of dental knowledge and behaviors among two geographical areas knowledge / behavior a no. % z-propr. 0 b 20 9.4 4.68 s p<0.05 th 8 5.5 10 b 16 7.5 6.82 hs p<0.01 th 9 6.3 s=significant, hs=highly significant. question number area no. of positive z-prop no. % q1 b 102 70.8 14.6 hs p<0.01 th 43 39.8 q2 b 97 67.4 1.66 hs p<0.01 th 80 74.1 q3 b 54 37.5 9.66 hs p<0.01 th 19 17.6 q4 b 66 45.8 47.3 hs p<0.01 th 10 9.3 q5 b 107 74.3 44.7 hs p<0.01 th 32 29.6 q6 b 114 79.2 45.8 hs p<0.01 th 27 25.0 q7 b 58 40.3 1.114 s p<0.05 th 48 44.4 q8 b 108 75.0 66.8 hs p<0.01 th 67 62.0 q9 b 32 22.2 2.66 s p<0.05 th 51 47.2 q10 b 97 67.4 12.3 hs p<0.01 th 49 45.4 salam f.doc j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry134 photogrammetric analysis of facial soft tissue profile of iraqi adults sample with class ii div.1 and class iii malocclusion: (a comparative study) salam r. abd-alwhab, b.d.s. (1) dhiaa j. nasir, b.d.s., m.sc. (2) abstarct background: the purposes of this study were to determine the photogrammetric soft tissue facial profile measurements for iraqi adults sample with class ii div.1 and class iii malocclusion using standardized photographic techniques and to verify the existence of possible gender differences. materials & methods: seventy five iraqi adult subjects, 50 class ii div.1 malocclusion (24 males and 26 females), 25 class iii malocclusion (14 males and 11 females), with an age range from 18-25 years. each individual was subjected to clinical examination and digital standardized right side photographic records were taken in the natural head position. the photographs were analyzed using autocad program 2007 to measure the distances and angles used in the soft tissue photogrammetric analysis. descriptive statistics was obtained for (29) measured variables for both genders and independentsamples t-test was performed to evaluate the genders difference. results &conclusions: the results indicated that: males had greater facial heights and lengths as well as greater prominences of facial dimensions in class ii div.1 and class iii malocclusion. the mean values of all angular variables were higher in females than males in the class ii div.1 exceptin the following angular measurements: vertical nasal angle,angle of the nasal dorsum,cervicomental angle andangle of the lower facial third,with larger male dimensions in all linear measurements of the nasal, lips, chin area and facial analysis except upper facial third.independent ttestshowed statistically significant gender differences in the vertical nasal angle, nasal angle, nasofrontal angle; angle of the nasal dorsum; nasolabial angle, cervicomental angle, lower facial third, facial depth subnasal depth, nasal prominence, length of upper lip, length of lower lip of pogonion and height of chin,while in the class iii malocclusionthe mean values of all angular variables were higher in males than females except in the following: nasofrontal angle, nasal angle,nasolabial angle,mentolabial angleandangle of the middle facial third with larger male dimensions in all linear measurements of the facial, lips, chin area and nose analysisexcept the height of nasal tip, nasofrontal angle, nasal angle, nasolabial angle, angle of total convexity, lower facial third, upper lip, upper lip, prominence of lower lip, prominence of chin and height of chin. independent t-test showed statistically significant gender differences. key words: photogrammetric analysis, soft tissue, class ii div.1 or class iii malocclusion. (j bagh coll dentistry 2013; 25(4):134-144). introduction orthodontics has generally led the way in quantitative analysis of the soft tissue facial architecture, developing norms and longitudinal data, important equally to maxillofacial surgeons, plastic surgeons and to clinicians in prosthetic dentistry. apart from the continuing attention received from clinical medicine, the face is now attracting serious study from diverse professions and is even becoming "big business" [1]. the faces were classified into straight, convex, and concave. this can be done with the patient either sitting upright or standing, but not reclining in a dental chair, and looking at the horizontal or a distant object, with the head in this position, note the relationship between two lines, one dropped from the bridge of the nose to the base of the upper lip, and a second one extending from that point downward to the chin. these line segments should form a nearly straight line. an angle between them indicates either profile convexity (upper jaw prominent relative to chin) or profile (1)m.sc. student. department of orthodontics, college of dentistry, baghdad university. (2)assistant professor. department of orthodontics, college of dentistry, baghdad university. concavity (upper jaw behind chin). a convex profile therefore indicates a skeletal class ii jaw relationship, whereas a concave profile indicates a skeletal class iii jaws relationship [2]. photogrammetry has existed within the profession of civil engineering, photogrammetry is a discipline devoted almost entirely for solving the problems of making accurate three-dimensional measurements from a pair of two-dimensional projected images [3]. photographic analyses are inexpensive, yet do not expose the patient to potentially harmful radiation, and could provide better evaluation of the harmonic relationship among external craniofacial structures [4]. facial photography is considered as a guide to the position of the teeth, and establishing of dimensions of two jaws relationship in three dimensions of vertical, antero-posterior and mediolateral [5]. however, the lack of morphologic balance among different skeletal components can be masked by compensatory soft tissue contribution [6]. other advantages of camera imaging can be used to assess the symmetry of the face, profile j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry135 and facial types, serves as a record of the patient and to assess the progress of a case by comparing the preoperative and postoperative photographs [7]. the photographic analysis advantages are economic, safe because patient kept from radiation [8], but not considered as a specific diagnostic parameter but to evaluate facial appearance [9]. materials and methods sample the sample of this study was iraqi adult people collected from orthodontic department, college of dentistry, university of baghdad, 50 class ii div.1 malocclusion (24 males and 26 females), 25 class iii malocclusion (14 males and 11 females), with an age range from 18-25 years [10]. the sample was selected according to the following criteria: 1. skeletal relation: skeletal class ii and class iii relationship determined clinically by two fingers method [11]. 2. dental relation: a) for class ii subjects: class ii div 1 malocclusion with overjet more than 4mm with bilateral class ii buccal segment (molar or canine)[11.14]. b) for class iii subjects: class iii malocclusion with reverse overjet with bilateral class iii buccal segment (molar or canine)[12]. 3. presence of full permanent dentition regardless the third molars. 4. no history of previous orthodontic treatment or orthognathic surgery. 5. no history of facial trauma or craniofacial disorder, such as cleft lips and palate. instruments and equipment: 1. sterilizer (memmert, germany). 2. millimeter graded vernier (dentaurum, germany). 3. measuring tape, used to measure the distance between subject and camera lens. 4. dental mouth mirrors and kidney dish 5. gloves for clinical examination. 6. sharpened pencil. 7. professional digital camera (canon eos rebel t3i, 18 mega pixels, dslr camera, japan). 8. memory flashes (transcend, 16 gb, japan). 9. analyzing equipment: a. pentium iv portable computer (fujitsu). b. analyzing software (autocad 2007). 10. plump line with (0.5 kg) weight hung. 11. mirror held on stand. 12. a blue background panel, 0.95 m width and 1.10 m length. 13. connection cable between camera and primary flash. 14. macro lens 100 mm, canon japan. a 100 mm focal lens was selected in order to maintain the natural proportions [13]. 15. a height adjustable tripod, used for fixing the camera in position. 16. scale fixed by movable stand. 17. primary flash and secondary flash respectively. methods each individual was seated on a dental chair and asked information about name, age, origin, history of facial trauma and previous orthodontic treatment. then the subject was clinically examined (extra-orally and intra-orally). clinical examination 1. assessment of the anteroposterior skeletal relationships. 2. assessment of the dental relationship. 3. measurement of the overjet. 4. measurement of the overbite. photographic set-up the photographic set-up consisted of a tripod that held a digital camera, optical axis of the lens (macro lens 100 mm) and a primary flash. the tripod controlled the stability and the correct height of the camera according to the subject’s body height and ensured the correct horizontal position of the optical axis of the lens. a 100 mm focal lens was selected in order to maintain the natural proportions. a primary flash was attached to the tripod by a lateral arm, at a distance of 27 cm from the optical axis of the camera and 75 degrees from the upper right angle. another element of the set-up was a secondary flash, the secondary flash placed behind the subject. its function was to light the background and eliminate undesirable shadows from the contours of the facial profile. a slave cell allowed synchronization with the main flash [14]. photographic records the camera was used in its manual position; the shutter speed was 1/125 per second, and the opening of the aperture f/2.8. the subject was positioned on a line marked on the floor, and a vertical scale divided into millimeters was placed behind the subject, infront of the scale a plumb line; suspending a 0.5 kg weight was held by a thick black thread that indicated the true vertical (tv) plane ,on the photographs and 120 cm j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry136 infront of the subject and on the opposite side of the scale outside the frame there was a vertical mirror, the center of the camera lens was kept at approximately110 cm away from the subject, this distance was standardized to obtain sharp image [15]. in order to take the records for right side of subject in nhp, the subjects were asked to walk a few steps, stand at rest facing the mirror, in front of the scale and look into their eyes in the mirror, and place their arms at their side. the lips should also be relaxed, adopting the position as they normally show during the day, before starting the recording procedure, the patients were instructed to remove the eye glasses and the operator ensured that the patient’s forehead, neck, and ears were clearly visible during the recording [14](fig.1). figure 1: standardized right side profile in nhp photogrammetric analysis the pictures after recoding were imported to the autocad program, and appeared in the master sheet, on which the points and planes were determined, and then the linear and angular soft tissue landmarks were marked andphotogrammetric analysis was carried out. the expected magnification in the linear measurements was corrected by using a scale for each picture with appropriate equation (fig 2). figure 2: photogrammetric analyses by autocad program soft tissue landmarks a) facial landmarks: according to fernandez riveiro, [15] (fig.3). 1. point n' (nasion soft tissue): the point of deepest concavity of the soft tissue contour of the root of the nose. 2. point sn (subnasale): the point where the lower border of the nose meets the outer contour of the upper lip 3. point cm (columella): the most anterior point on the columella of the nose. 4. point pog' (soft tissue pogonion): the most prominent point on the soft tissue contour of the chin. 5. point li (labiale inferior): the point that indicates the mucocutaneous limit of the lower lip 6. point ls (labiale superior): the point that indicates the mucocutaneous limit of the upper lip 7. point me' (menton soft tissue): the most inferior point of the inferior edge of the chin. 8. point c (cervical): the intersection of lines tangent to neck and throat. 9. point tri (trichion): the sagittal midpoint of the forehead that borders the hairline. 10. point mn (mid nasal): a pronounced convexity of the dorsal profile of the nose 11. point trg (tragus): the most posterior point of the auricular tragus. 12. point sm (supramentale): the point of greatest concavity in the midline of the lower lip between labraleinferius and menton. 13. pointstomion superior (sts), the most inferior point of the upper lip. 14. pointstomion inferior (sti), the most superior point of the lower lip. 15. point prn (pronasale or nasal tip): the most prominent point of the tip of the nose. 16. point g' (glabella): the most anterior point of the middle line of the forehead figure 3: landmarks used in this investigation. g', glabella; n', nasion; mn', mid nasal; prn, pronasal; cm, columella; sn, subnasal; ls, labial superior; li, labial inferior; sm, supramental; pog' , pogonion; me', menton; c', cervical; trg, tragus; stomion superior (sts),stomion inferior (sti). j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry137 b) facial planes and lines: according to fernandez riveiro [15] (fig.4). 1. true vertical line (tvl): the line was placed through soft tissue nasion and was perpendicular to the true horizontal line. 2. true horizontal line (thl): the line was placed through soft tissue tragus and was perpendicular to the true vertical line. 3. g'sn line: the line between points glabella and subnasale 4. sn-columella line: the line between points subnasale and the most anterior point on the columella of the nose. 5. snls line: the line between points subnasale and the median point in the upper margin of the upper membranous lip. 6. snpog' line: the line between points subnasale and soft tissue pogonion 7. g'-n' line: the line between points glabella and soft tissue nasion. 8. n'-prn line: the line between points soft tissue nasion and the tip of the nose. 9. n'-mn line: the line between points soft tissue nasion and mid nasal. 10. li-sm line: the line between point labiale inferior and supramentale. 11. sm-pog' line: the line between points supramentale and soft tissue pogonion. 12. c-me' line: the line between points cervical and soft tissue menton. 13. g'-pog'line: the line between points glabella and soft tissue pogonion. 14. n'-trag line: the line between points soft tissue nasionand tragus. 15. trag-sn line: the line between points tragusand subnasale. 16. trag-me' line: the line between points tragus and soft tissue menton. 17. sn-sm line (canut’s line): the line between points subnasale and supramentale. 18. g'-prn line: the line between points glabella and tip of the nose. 19. prn-pog' line: the line between points tip of the nose and soft tissue pogonion. 20. n'-pog' line: the line between pointssoft tissue nasion and soft tissue pogonion. 21. mn-prn line: the line between points mid nasal and the tip of the nose. figure 4: facial planes and lines used in the study facial measurements a) angular measurements: according to fernandez riveiro [14] (fig.5) and (fig.6). 1. g'–n'–prn-: nasofrontal angle. 2. cm–sn/n'–prn: nasal angle. 3. n'–prn/tv (n): vertical nasal angle. 4. n'–mn–prn: angle of the nasal dorsum. 5. cm–sn–ls: nasolabial angle. 6. li–sm–pog': mentolabial angle. 7. c–me'/g'–pog': cervicomental angle. 8. n'–trg–sn: angle of the middle facial third. 9. sn–trg–me': angle of the lower facial third. 10. sn–sm/th: angle of the head position. 11. g'–sn–pog': angle of the facial convexity. 12. g'–prn–pog': angle of the total facial convexity. figure 5: angular measurements of the analysis figure 6: angular parameters of the facial convexity. a) angle of facial convexity. b) angle of total facial convexity. j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry138 b) linear measurements: according to fernandez riveiro [15]. the reference lines were: (fig.7). 1) tv through n. 2) th through trg. 1) vertical linear measurements (parallel to tv line): (fig.8). 1. upper facial third, tri-g'. 2. middle facial third, g'-sn. 3. lower facial third, sn-me'. 4. nasal length, n'-sn. 5. length of upper lip, sn-sts. 6. length of lower lip, sti-sm. 7. height of chin, sm-me'. 8. height of nasal tip, sn-prn. figure 7: the reference lines used in this study. figure 8: vertical measurements (parallel to tv line). 2) horizontal linear measurements (parallel to th line): (fig.9). 1. facial depth, trg-sn 2. nasal prominence,prn /tv (n') 3. subnasal depth, sn /tv (n') 4. mentolabial depth, sm /tv (n') 5. prominence of upper lip, ls /tv (n') 6. prominence of lower lip, li /tv (n') 7. prominence of chin, pog /tv (n') figure 9: horizontal measurements (parallel to th line). 3) canut’s linear measurements (perpendicular to sn-sm line): (fig.10). 1. canut’s nasal prominence. 2. canut’s prominence of pogonion. figure 10: measurements related to sn-sm line. results 1. photogrammetric analysis of angular measurements in degree (°) descriptive statistics and gender differences of angular measurements for clii division 1: the mean values for the measured angular measurements were: 1. higher in males than females for: vertical nasal angle; angle of the nasal dorsum; cervicomental angleand angle of the lower facial third. 2. higher in females than males for: nasofrontal angle; nasal angle; nasolabial angle; mentolabial angle; angle of the head; angle of the middle facial third; angle of facial convexity and angle of total facial convexity. independent t-test was done to find the gender differences regarding the measured angles as following: (table. 1). a significant difference between genders regarding vertical nasal angle, nasal angle nasofrontal angle; angle of the nasal dorsum; nasolabial angle and cervicomental angle. j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry139 table 1: descriptive statistics and gender differences of angular measurements for cl ii division 1 (in degree o) variables male (n=24) female (n=26) gender difference (d.f.=48) mean s.d. mean s.d. t-test p-value g-n/prn 141.54 4.95 145.15 3.86 -2.89 0.006 ** cm-sn/n-prn 73.67 4.26 82.04 5.77 -5.79 0.000 *** n'-prn/tv(n) 32.88 3.53 30.46 3.33 2.49 0.016 * n-mn/prn 173.63 4.64 168.77 6.56 3 0.004 ** cm-sn-ls 94.71 9.41 102.42 5.99 -3.49 0.001 *** li-sm-pog 116.33 11.42 122.12 14.51 -1.56 0.126 (ns) c-me/g'-pog 104.96 6.34 98.42 8.93 2.96 0.005 ** n'-trg/sn 29.58 2.24 30.69 2.26 -1.74 0.088 (ns) sn-trg-me 38.08 3.35 36.77 3.12 1.44 0.157 (ns) sn-sm/th 73.54 5.55 74.77 4.6 -0.85 0.397 (ns) g'-sn-pog 158.29 3.64 159.15 3.84 -0.81 0.42 (ns) g-prn-pog 133.96 4.75 135.5 4.9 -1.13 0.265 (ns) descriptive statistics and gender differences of angular measurements for cliii the mean values for the following angular measurement variables were as the following: (table.2) 1higher in females than males for nasofrontal angle; nasal angle; nasolabial angle; mentolabial angle and angle of the middle facial third. 2higher in males than females forvertical nasal angle; angle of the nasal dorsum;cervicomental angel; angle of the lower facial third; angle of the headand angle of facial convexity; angle of total convexity. independent t-test was done to find the gender differences regarding the measured angles and as following: a significant difference between genders in measured variables in: nasofrontal angle, nasal angle, nasolabial angle and angle of total convexity. table 2: descriptive statistics and gender differences of angular measurements for cliii (in degree) variables male (n=14) female (n=11) gender difference (d.f.=23) mean s.d. mean s.d. t-test p-value g-n/prn 141.5 6.28 147.09 6.07 -2.24 0.035 * cm-sn/n-prn 78.07 6.57 83.36 5.1 -2.2 0.038 * n'-prn/tv(n) 29.57 4.69 28.09 2.81 0.92 0.365 (ns) n-mn/prn 172.29 5.48 171.91 5.39 0.17 0.865 (ns) cm-sn-ls 96.07 6.29 105.45 11.09 -2.67 0.014* li-sm-pog 144.29 9.75 144.64 5.2 -0.11 0.915 (ns) c-me/g'-pog 98.64 3.93 97.45 6.44 0.57 0.574 (ns) n'-trg/sn 30.43 2.53 30.73 1.27 -0.36 0.725 (ns) sn-trg-me 37.57 3.63 35 2.28 2.05 0.052 (ns) sn-sm/th 86.07 3 84 5.37 1.23 0.233 (ns) g'-sn-pog 174.64 4.31 172.64 3.96 1.2 0.243 (ns) g-prn-pog 146.43 4.29 141.45 5.22 2.62 0.015 ** 2) photogrammetric analysis of linear measurements (in mm). descriptive statistics and gender differences of facial dimensions descriptive statistics and gender differences of facial dimensions for cl ii division1 the mean values for the linear measurement variables are as the following: (table.3) 1higher in males than females formiddle facial thirdg'-sn, lower facial thirdsn-me and facial depthtrg-sn. 2higher in females than males forupper facial third tri-g' . independent t-test was done to find the gender differences regarding the measured dimensions and as following: aa very highly significant j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry140 difference regarding lower facial third sn-me and facial depthtrg-sn. table 3: descriptive statistics and gender differences of facial dimensions analysis for clii div 1(in mm) variables descriptive statistics gender difference (d.f.=48) total (n=50) male (n=24) female (n=26) mean s.d. mean s.d. mean s.d. t-test p-value tri-g' 47.49 5.39 47.41 4.9 47.57 5.9 -0.1 0.919 (ns) g'-sn 65.91 4.07 66.51 4.26 65.35 3.89 1.01 0.319 (ns) sn-me 68.69 6.35 72.15 5.11 65.49 5.74 4.32 0.000 *** trg-sn 104.53 6.92 108.31 6.12 101.03 5.75 4.34 0.000 *** descriptive statistics and gender differences of facial dimensions for cliii: (table.4) in general, the mean values of all measured variables were higher in males than females. independent t-test showed a highly significant difference regardinglower facial thirdsn-me. table 4: descriptive statistics and gender differences of facial dimensions analysis for cliii (in mm) variables descriptive statistics gender difference (d.f.=23) total (n=25) male (n=14) female (n=11) mean s.d. mean s.d. mean s.d. t-test p-value tri-g' 48.26 5.14 48.31 5.86 48.19 4.33 0.06 0.953 (ns) g'-sn 66.47 5.27 67.79 5.73 64.8 4.3 1.44 0.164 (ns) sn-me 71.04 5.31 74.57 3.74 66.55 3.15 5.69 0.000 *** trg-sn 101.57 7.03 103.55 7.96 99.06 4.89 1.64 0.116 (ns) descriptive statistics and gender differences of nose analysis:descriptive statistics and gender differences of nose analysisfor clii division 1: (table.5) in general, the mean values of all measured variables are higher in males than females. independent t-test was showed a significant difference regarding subnasal depth sn /tv (n) and nasal prominence prn /tv (n). table 5: descriptive statistics and gender differences of nose analysis for clii div. 1 (in mm). variables descriptive statistics gender difference (d.f.=23) total (n=25) male (n=14) female (n=11) mean s.d. mean s.d. mean s.d. t-test p-value tri-g' 48.26 5.14 48.31 5.86 48.19 4.33 0.06 0.953 (ns) g'-sn 66.47 5.27 67.79 5.73 64.8 4.3 1.44 0.164 (ns) sn-me 71.04 5.31 74.57 3.74 66.55 3.15 5.69 0.000 *** trg-sn 101.57 7.03 103.55 7.96 99.06 4.89 1.64 0.116 (ns) descriptive statistics and gender differences of nose analysis for cliii: the mean values for the following linear measurement variables are as the following: all measured variables higher in males except sn-prn (table.6), there is non-significant genders difference for all measured variables. table 6: descriptive statistics and gender differences of nose analysis for cliii (in mm) variables male (n=14) female (n=11) gender difference (d.f.=23) mean s.d. mean s.d. t-test p-value n'-sn 54.53 2.71 52.77 3.43 1.44 0.164(ns) prn/sn-sm 14.65 1.59 14.19 1.28 0.78 0.45(ns) prn/tv(n) 22.79 3.82 21.91 1.86 0.7 0.493(ns) sn-prn 12.53 1.79 12.87 1.52 -0.51 0.618(ns) sn/tv 7.3 3.87 5.95 2.74 0.98 0.339(ns) j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry141 descriptive statistics and gender differences of the lips analysis: descriptive statistics and gender differences of the lips analysis for clii division 1: (table.7) the mean values of all measured variables were higher in males than females. independent ttest was showed a highly significant difference regarding length of upper lip sn-sts and length of lower lip sti-sm. table 7: descriptive statistics and gender differences of the lip analysis for clii div. 1(in mm) variables descriptive statistics gender difference (d.f.=48) total (n=50) male (n=24) female (n=26) mean s.d. mean s.d. mean s.d. t-test p-value sn-sts 22.6 3.48 24.07 3.16 21.25 3.25 3.1 0.003 ** sti-sm 17.06 2.33 18.14 2.16 16.07 2.06 3.47 0.001 ** ls / tv 13.33 3.58 14.33 3.64 12.42 3.33 1.94 0.059(ns) li / tv 7.8 4.88 7.82 5.26 7.77 4.6 0.03 0.974(ns) descriptive statistics and gender differences of the lip analysis for cliii: (table.8). in general, all males show larger mean values than females. independent t-test was showed a significant difference regardingupper lip ls / tv, upper lipsn-stsand prominence of lowerlip li / tv. table 8: descriptive statistics and gender differences of the lip analysis for cliii variables descriptive statistics gender difference (d.f.=23) total (n=25) male (n=14) female (n=11) mean s.d. mean s.d. mean s.d. t-test p-value sn-sts 21.99 2.44 23.35 2.03 20.26 1.74 4.01 0.001 *** sti-sm 20.13 2.21 20.52 2.01 19.63 2.45 1 0.328 (ns) ls / tv 8.67 3.8 10.23 3.56 6.69 3.23 2.57 0.017 * li / tv 9.9 4.82 11.71 4.38 7.59 4.5 2.31 0.03 * descriptive statistics and gender differences of the chin area: descriptive statistics and gender differences of the chin area for clii div.1:(table.9). the mean values of all measured variables are higherin males than females. independent t-test showed a significant difference regarding canut’s prominence of pogonion pog/sn-sm and height of chin sm-me. table 9: descriptive statistics and gender differences of the chin area for clii div.1 (in mm) variables male (n=24) female (n=26) gender difference (d.f.=48) mean s.d. mean s.d. t-test p-value sm-me 28.04 2.6 25.94 2.48 2.92 0.005 ** sm / tv -0.60# 4.71 -0.99# 4.61 0.3 0.767 (ns) pog /tv 1.31 5.66 -0.09# 4.97 0.93 0.355 (ns) pog/sn-sm 4.67 2.34 3.26 1.91 2.35 0.023 * # the negative sign will indicate backward position in relation to tv descriptive statistics and gender differences of the chin area for cliii:(table10). the mean values of all measured variables are higherin males than females. independent t-test showed asignificant difference regarding prominence of chin pog /tv (n) and height of chinsm-me. table 10: descriptive statistics and gender differences of the chin area for cliii (in mm) variables descriptive statistics gender difference (d.f.=23) total (n=25) male (n=14) female (n=11) mean s.d. mean s.d. mean s.d. t-test p-value sm-me 28.77 3.56 30.72 2.77 26.27 2.88 3.92 0.001 ** sm / tv 5.2 4.25 6.22 4.67 3.91 3.43 1.37 0.183 (ns) pog /tv 5.56 5.39 8.29 5.71 2.09 1.92 3.43 0.002 ** pog/sn-sm 2.57 2.33 2.88 2.85 2.17 1.47 0.75 0.46 (ns) j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry142 discussion an improvement in soft tissue facial esthetics in orthodontics is one of the most important goals of treatment. as a consequence, many studies have been performed to understand the different characteristics of soft tissue; these include the different architecture of soft tissue in different individuals, soft tissue profile for populations, the response of the soft tissue to orthodontic treatment, and the inter-relationship of the nose, chin, and lips in achieving harmonious soft tissue profiles. it is important to mention that, this study is considered as the first and only photogrammetric research in iraq that dealt with class ii and iii patterns and there were even very little information all over the world regarding them, so the comparisons mostly were done depending on previous studies that were done in normal occlusion, the purpose of this research to establish average parameters that define the soft tissue facial profile of class ii div.1 and class iii of iraqi orthodontic patients and compared them with other previous researches. two-dimensional photogrammetry has been used for evaluating the soft tissues in orthodontic treatment. the method was shown to be sufficiently reproducible since it was simple to achieve in a conventional setting, without the need for special equipment [16]. gender differences for class ii div. 1: photogrammetric analysis of angular measurements (°). 1. the nasofrontal angle (g – n – prn): this angle showed statistically highly significant gender differences; with wider angle in females than males. this may indicate a more flattening of females forehead than males, this came to be in agreement with fernandez riveiro [14]; aljanaby [17]; malkoç et al,[13], and in contrast to the findings ofepker[18]. 2. the nasal angle (cm – sn/n – prn): showed statistically very highly significant gender differences, the mean value was larger in females than males. this came in agreement with fernandez riveiro [17] and disagreed with aljanaby[17] and malkoç et al, [13]. 3. vertical nasal (nprn/tv) angle: demonstrated significant gender difference, it was wider in males than in females, this came in agreement with fernández-riveiro et al,[14]; malkoç et al,[13]and aljanaby[17]. 4. nasal dorsum (n – mn – prn) angle: showed statistically significant gender difference with wider angles in males than in females, this came in agreement with fernández-riveiro et al, [14];aljanaby [17]and malkoç et al, [13]. 5. the cervicomental angle (c-me/gpog): was larger in males than in females and showed highly significant differences between genders, this came to be in agreement with the findings of aljanaby [17] and malkoç et al,[13] however this came to be in contrast with the findings of fernández-riveiro et al,[14]. 6. the nasolabial angle(cm – sn – ls): was significantly higher in females which coincided with the findings of milosevic et al, [19]andmalkoç et al, [13], while disagreed with fernández-riveiro et al, [14]and aljanaby [17]. photogrammetric analysis of linear measurements (in mm.): 1. facial analysis: a. facial heights: the lower facial third (sn-me) was larger in males than females and showed statistically highly significant and this came to be in agreement fernández-riveiro et al,[15]; aljanaby [17]. b. facial depth: facial depth (trg-sn) was also larger in males than females and showed very highly significant this came to be in agreement with fernández-riveiro et al,[15]; aljanaby,[17]. 2. nose analysis: when statistically analyzing the nose, the following were observed: a) nasal prominence (prn/tv): was larger in males than females, showed highly significant difference between them, this came to be in agreement withfernández-riveiro et al, [15]; aljanaby [17]. b) subnasal depth (sn/tv through n'): was significantly larger in males than females, this may be due to a more anterior position of (sn) point in males than in females, this came to be in agreement with fernández-riveiro et al, [15]; aljanaby [17]. 3. lip analysis: the mean values of (sn-sts and sti-sm) were significantly larger in males than in females, this came to be in agreement with (fernándezriveiro et al, [15]; aljanaby [17]. both the upper lip (ls-tv) and the lower lip (li-tv) through (n') showed statistically gender difference, and came to be in contrast to fernández-riveiro et al,[15]; aljanaby [17]. 4. chin area analysis: all the measurements of the chin area showed greater length and greater prominence in males than in females. (sm-me) and (pog/sn-sm) showed significant difference, this came to be in agreement withfernández-riveiro et al, [15]; aljanaby[17]. j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry143 gender differences for cl iii samples: photogrammetric analysis of angular measurements (°). 1. the nasofrontal angle (g – n – prn): was significantly larger in females than males, this came to be in agreement with fernándezriveiro et al,[14]; malkoç et al,[13]; aljanaby[17]. 2. the nasal angle (cm – sn/n – prn): was significantly larger in females than males, this came to be in agreement with fernándezriveiro et al,[14]; milosevic et al,[19] and disagreed with malkoç et al[13]; aljanaby[17]. 3. the nasolabial angle(cm – sn – ls): was larger in females than males (more acute in males) showed statistically significant gender differences and agreed with finding of milosevic et al, [19]; malkoç et al, [13], while disagreed withfernández-riveiro et al,[14]; aljanaby, [17]. 4. total facial convexity (g–prn–pog): angle of total facial convexity showed statistically siginificant this finding disagreed with fernández-riveiro et al, [13]; milosevic et al,[19]; malkoç et al,[13]; aljanaby, [17]. photogrammetric analysis of linear measurements (in mm.) 1. facial analysis: a)facial heights (upper facial third; trig,middle facial third; g-sn,lower facial third; sn-me): larger in males than in females, the lower facial third (sn-me) was statistically very highly siginificant and this came to be in agreement with fernández-riveiro et al,[15]; aljanaby, [17]. b)facial depth(trg-sn): was larger in males than in females, showed non-significant difference between genders, this came in contrast to fernández-riveiro et al,[15]; aljanaby, [17]. 2. nose analysis: prn/sn-sm was larger in males than in females, showed statistically non-significant difference, this came to be in agreement withaljanaby, [17]while disagreed withfernández-riveiro et al, [15]. 3. lips analysis: the length of upper lip (sn-sts) in males was larger than in females with a highly significant difference between genders, came to be in agreement with fernández-riveiro et al, [15]; aljanaby, [17]. both the upper lip (ls-tv) and the lower lip (li-tv) through (n') were larger in males than in females, showed statistically significant difference, and this came to be in agreement with fernández-riveiro et al,[15]; aljanaby, [17]. 4. chin area analysis: all the measurements of the chin area showed greater length and greater prominence in males than in females, sm-me and pog /tv showedsignificant difference, this came to be in agreement with fernández-riveiro et al, [15]; aljanaby, [17]. comparison between clii and cli angular measurements: 1. n-prn/tv: was significantly larger in clii than cliii in both genders, this came to be in agreement with malkoç et al, [13]. 2. li-sm/pog:was significantly smaller in clii than cliii in both genders which came to be in agreement with spalding, [20]. 3. g-sn/pog, g-prn/pog and sn-sm/th: were significantly larger in cliii in both genders, came to be in agreement withproffit et al, [2]. linear measurement: 1. prn/sn-sm: was significantly larger in cliii, came to be in agreement with proffit et al, [2]. 2. sn/tv: was significantly larger in clii, came to be in agreement with kumar and tamizharasi, [21]. 3. sti-sm: was significantly larger in cliii in both genders, came to be in agreement with ricketts et al, [22]. 4. ls-tv: was significantly larger in clii in both genders proffit et al [2]. 5. sm-tv: was significantly larger in cliii than in clii, came to be in agreement withpowell and humphrys [23]. references 1. alcade re, jinno ti, orsini me, susakia, sugiyarm, matsumura t. soft tissue cephalometric 1968 norms in japanese adults. am j dentofac orthop, 2000; 118: 84-9. 2. proffit wr, fields hw, sarver dm. contemporary orthodontics.4th ed. st.louis: mosby elsevier; 2007. 3. baumrind s, moffitt fh, curry s. three dimensional x-ray stereometry from paired coplanar images: a progress report. am j orthod 1983; 84(4): 292-312. 4. cox nh, vander linden fpgm. facial harmony. am j orthod 1971; 60:175-83. 5. charles m, heartwell jr, arthur or. syllabus of complete dentures. 2nd ed. lea and febiger; 1975. 6. yogasawa f. predicting soft tissue profile changes of concurrent with orthodontic treatment. angle orthod 1990; 60(3):199-206. (ivsl). 7. al-mulla aa. orthodontic the challenge. iraq; 2009. 8. ferorrio vf, sforza c, miani a, pizzini g. craniofacial morphology by photographic evolution. am j orthod 1993; 104 (4): 327-36. 9. bishara se. a textbook of orthodontics. 1st ed. philadelphia: w.b. saunders company; 2001. 10. kalha as, latif a, govardhane sn. soft tissue cephalometric norms in a south indian ethnic population. am j orthod dentofac orthop 2008; 133(6): 876-81. j bagh college dentistry vol. 25(4), december 2013 photogrammetric analysis of pedodontics, orthodontics and preventive dentistry144 11. foster td. a textbook of orthodontics. 2nd ed. oxford: blackwell scientific publications; 1985. 12. houston wjb. the analysis of errors in orthodontic measurements. am j orthod 1983; 83(5): 382-90. 13. malkoc s, demir a, uysal t, canbuldu n. angular photogrammetric analysis of the soft tissue facial profile of turkish adults. eur j orthod 2009; 31(2): 174-9. (ivsl). 14. fernandez-riveiro p, smyth-chamosa e, suarezquintanilla d, suarez-cunqueiro m. angular photogrammetric analysis of the soft tissue facial profile. eur j orthod 2003; 25(3): 393-9. 15. fernandez riveiro p, quintanilla ds, chamosa es, cunqueiro mf. analysis of soft tissue facial profile am j orthod dentofac orthop 2002; 122(l): 59-66. 16. muge a, demet k, ilken k. reliability of reference distances used in photogrammetry. angle orthod 2010; 80 (4):670-7. 17. aljanabi s. photogrammetric analysis of facial soft tissue profile of iraqi adults sample with class i normal occlusion. a master thesis, department of orthodontics, college of dentistry, university of baghdad, 2011. 18. epker bn. adjunctive esthetic surgery in the orthognathic surgery patient. in: mcnamara ja, carlson ds, ferrara a, editors. esthetic and the treatment of facial form. vol 28.craniofacial growth series. ann arbor: center for human growth and development; university of michigan; 1992. p. 187216. 19. milosevic sa, varga ml, slaj m. analysis of the soft tissue facial profile by means of angular measurements. eur j orthod 2008; 30(2) 135-40. 20. spalding pm. treatment of class ii malocclusion. [cited by: bishara se. a textbook of orthodontics. 1st ed. philadelphia: w.b. saunders company; 2001. pp. 324375]. 21. kumar s, tamizharasi. reliability of photographicanalysis in determining the malocclusion using different facial profiles and facial types among college students in the age group of 19-24 yearsa pilot study.jiads. 2010; 1(3): 7-10. 22. ricketts rm, berch rw, gugino cf, hilgers jj, schulhof rj. bioprogressive therapy. book 1. rocky mountain orthodontics; 1980. 23. powell n, humphreys b. proportion of esthetic face. new york: thieme; 1984. p. 38. shnay.doc j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 90 effect of different palatal vault shapes and woven glass fiber reinforcement on dimensional stability of high impact acrylic denture base [part i] shnay m. atiyah, b.d.s., h.d.d. (1) thekra i. hamad, b.d.s., m.sc., ph.d. (2) abstract background: change in palatal vault shape and reinforcement of high impact acrylic denture base resin may in turn affect the dimensional accuracy of acrylic resin and affecting the fitness of the denture.this study evaluated tostudy the effect of fiber reinforcement for high-impact acrylic resin denture base with different palatal vault shapes on adaptation or gap space between the denture base and the stone cast and compare with non-fiber reinforcement and effect of palatal vault shapes on adaptation of non-reinforced and fiber reinforced high impact denture base acrylic resin material and method: three different palatal vault shapes were prepared on standard casts using cnc (computer numerical control) machine. 60 samples of heat polymerized high impact acrylic resin maxillary denture base were fabricated onto each definitive cast according to manufacturer instruction. samples divided into three main experimental groups represented the three different palatal vault shapes (20 samples for each main group); 1st rounded 2nd u-shaped and the 3rd groups v-shaped. each main group divided into two subgroups (10 samples for each subgroup) representing non fiber reinforced high impact acrylic group as a control and the fiber reinforced high impact acrylic. the measurements of gap-space changes of denture bases done at two stages, 1st 24 hour after polymerization and 2nd measurement done after one month storage in distilled water at room temperature. results and conclusion: dimensional changes of high impact acrylic denture base not affected by glass fiber reinforcement p-value for all reference pointes ≥ 0.05, while topographical change in maxillary vault shapes effects on the gap-space in non-fiber reinforced high impact acrylic denture base p-value < 0.05 in point one, four, and seven. key words: high impact acrylic resin, topographical change in vault, woven glass fiber reinforcement. (j bagh coll dentistry 2014; 26(4):90-94). الخالصھ الكلریك ویؤثر بالتالي على ثبوتیھ الطقمدعم االكلریلك عالي الصدمات المستخدم في قاعده الطقم ممكن ان یؤثر على االستقرار البعدي للراتنج ا:المقدمھ صدماتھو بحث تاثیر الیاف االزجاج الداعمھ وتاثیر تغییر شكل القحف على االستقرار البعدي للطقم العلوي المصنوع من راتنج االكلریك عالي ال :الھدف من الدراسھ ثم یستنسخ القالب الحجري باستعمال ماده السلیكون الخاص للحصول , تعمال جھاز النحتبالكومبیوتر الرقميتم تحضیرثالثھ اشكال من القحف للفك العلوي باس:المواد والطرق المستعملھ ): عینھ لكل طریقھ 60(لقیاس التغییر باالبعاد . عینھ قاعده طقم علوي من ماده االكلریك عالي الصدمات تحضر لكل قالب صخري حسب تعلیمات المنشاء . 60 قالب صخر 06على 20ولكل مجموعھ , -uوحرف v-وشكل حرف,ثم العینات تقسم الى ثالث مجموعات رئیسیھ حسب شكل القحف وھي الدائري . یس مسافھ الفراغ بین القالب الحجري وقاعده الطقم تق كریلك عالي الصدمات غیر المدعم والمجموعھ الفرعیھ مجموعھ فرعیھاالولى تستخدم اال): عینات لكل مجموعھ فرعیھ 10(ثم كل مجموعھ رئیسیھ تقسم لمجموعتین فرعیتین, عینھ ساعھ من 24المرحلھ االولى بعد :كل القیاسات لمسافھ الفراغ بین القالب الحجري وقاعده الطقم تقاس لمرحلتین . الثانیھ تستخدم االكلریلك عالي الصدمات المدعم بااللیاف الزجاجیھ .یوم من حفظ العینات بالماء المقطر بدرجھ حراره الغرفھ 30الطبخ والمرحلھ الثانیھ للقیاس تتم بعد وتغییر شكل القحف یؤثر على مسافھ الفراغ الموجود بین , مسافھ الفراغ بین القالب الحجري وقاعده الطقم في االكریلك عالي الصدمات التتأثر بالدعم من االلیاف الزجاجیھ :النتائج ات تغییر شكل القحف یؤثرعلى مسافھ الفراغ في الراتنج االكریلك عالي الصدمات الغیر مدعم بینما الیؤثر على الراتنج االكریلك عالي الصدمباالضافھ . القالب الصخري وقاعده الطخم المدعم بااللیاف الزجاجیھ لكن تغییر شكل القحف یؤثر في مسافھ الفراغ في االكریلك عالي , متغییرومسافھ الفراغ الموجود بین القالب الحجري وقاعده الطقم الیتاثرباستعمال الیاف الزجاج الداع :االستنتاج الصدمات introduction most fractures of maxillary dentures are caused by a combination of fatigue and impact which is reported more in case where maxillary denture base oppose the mandibular natural teeth. the fracture of denture bases when dropped is due to impact force and authors have suggested that repeated flexing from chewing ultimately fatigues the denture in the mouth, in most situations, fractures occur in the midline of the maxillary dentures (1, 2). considering only the strength though the incorporation of fillers like rubber and fibers to heat-cured poly methyl methacrylate resin improves the impact strength and fatigue resistance(3),improvement may in turn affect some (1)master student. department of prosthodontics. college of dentistry, university of baghdad. (2)assistant professor . department of prosthodontics. college of dentistry, university of baghdad. of the properties of heat-cured poly methyl methacrylate resin such as dimensional accuracy, dimensional stability, water sorption, and affecting the fitness of the denture (4). highimpact acrylic denture base is made by the heatcured dough method; impact resistance arises from the incorporation of rubber phase into the beads during their suspension polymerization (5), an alternative of the direct addition of elastomers is the use of acrylic/elastomer copolymers. these are, typically, methyl methacrylate-butadiene or methyl methacrylate-butadiene styrene copolymers which are now available in certain commercial products (6). dimensional changes caused by water uptake are influenced by the storage period and may compensate the polymerization shrinkage to a certain extent (7). however, after 3 weeks of storage in water, no further significant dimensional changes were observed (8). j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 91 material and methods the study involves preparation of 60 samples of heat polymerized high impact acrylic resin maxillary denture base without artificial teeth onto definitive casts according to the recommendations of manufacturer, the samples divided into three main experimental groups represented the three different palatal vaults shapes (20 samples for each main group); 1st rounded, 2nd u-shaped and the 3rd groups vshaped. each main group divided into two subgroups (10 samples for each subgroup) representing the non-fiber reinforced high impact acrylic group (nf group) and the fiber reinforced high impact acrylic (wf group) (table 1). according to crossarch forms three casts with different palatal vault shapes were prepared by carving palatal vault of standard cast using cnc machine (computer numerical control). table 1: research methodology and grouping of the samples denture base without reinforcement preparation for denture base preparation in three different palatal vault shapes in non-fiber reinforced groups (nfo, nfu, and nfv) heat polymerized high impact acrylic powder and liquid was placed in clean, dry porcelain jar and mixed according to manufacturer instruction 10ml/21gm w/p ratio, mixing time 30 second until the monomer and polymer were thoroughly companied, the jar sealed and the mixture left for 5min at room temperature 22c° (±2) until reaching the dough stage. the resin removed from the jar, rolled and packed into the mold of each flask. denture bases with glass fiber reinforcement preparation reinforced high impact acrylic include groups wfo, wfu and wfv, woven type glass fibers were shaped to provide 2mm shorter border than the boundaries of acrylic resin bases (9). also a study recommended that woven glass fiber reinforcement should be placed on the tensile side of the specimens under loading resulted in considerably higher flexural strength and flexural modulus values (10). as result, in clinical situations the fiber reinforcement in complete maxillary denture base should be close to the oral surface of the denture and perpendicular to the midline. so, two layers of high impact acrylic resin precisely prepared to encase the woven glass fibers by using 2 and 3mm thickness record bases. finally for or all specimens (fiber reinforced and non-fiber reinforced high impact denture base) pressed in the hydraulic press under the load of 100 bar for 5 min. the flasks were placed in clamp and immersed in water bath 70°c for 90 min then the temperature raised to100°c for 30 min according to manufacturer instruction. after curing the flask was left to cool on bench for three hours (11). fig. 1: maxillary cast with denture base sectioned through two imaginary lines with a precision rotary microtome the samples deflasked with their corresponding stone cast and sectioned in two positions, first the specimens were sagittal sectioned with a precision rotary microtome in an anteroposterior direction along the imaginary line passing through the midline. a second frontal cross section prepared and its perpendicular to the sagittal section (12,113) (fig 1). the cutting was made on a fixer table under constant water cooling.four reference points were marked along the resin base/stone cast interface in sagittal section which corresponded to [anterior maxillary ridge (1), anterior part of vault area (2), middle of the vault area (3), posterior termination of vault area (4) ] (4) and three reference points were marked at frontal cross section which represent the posterior palatal border gap area measurement which corresponded to[ slop of posterior ridge (5), posterior maxillary ridge (6), middle of buccal vestibule (7) ](fig 2) (13-16). then the prepared acrylic specimens were kept in plastic containers containing distilled water.to determine the adaptation or interfacial gap between high impact acrylic resin bases and the stone casts after water storage a digital microscope used under magnification power of 200x. the total seven reference points at each specimen were j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 92 measuredat two periods first 24 hours after polymerization process and storage in distilled water. a second measurement was performed after the storage in distilled water for 30 days (17). fig. 2: total seven reference points for adaptation measurement results mean difference between two measuring interval calculated (24 hours and 30 daysimmersion in distilled water) for all reference points, standard deviation was examined for mean difference and subjected to statistical analysis (ttest, and anova test).t-test for gap space dimensional changes estimatedbetween nonreinforced and reinforced high impact acrylic in rounded, u-shaped, and v-shape maxillary vault shapes for seven reference points. the t-test result reveals non-significant difference in all reference points anova test for gap space dimensional changes affected by change in maxillary vaultshape for all reference points in reinforced and non-reinforced high impact acrylic denture base.when the difference wasfound to be statistically significant lsd test (least significant difference test) was used for examining differences between each 2 groups table 2: gap space (adaptation) of non-reinforced and fiber reinforced high impact acrylic denture base in different palatal vault shapes studied groups no-fiber with-fiber comparison no. mean difference (mm) ±sd no. mean difference (mm) ±sd t-test p-value sig. o -s ha pe 1 10 0.01 0 10 0.01 0 0.08 0.93 ns 2 10 0.012 0 10 0.013 0 0.55 0.58 ns 3 10 0.015 0 10 0.017 0 0.57 0.57 ns 4 10 0.01 0 10 0.016 0 0.32 0.74 ns 5 10 0.014 0 10 0.015 0 0.24 0.8 ns 6 10 0.009 0 10 0.012 0 0.28 0.82 ns 7 10 0.01 0 10 0.01 0 1.33 0.19 ns u -s ha pe 1 10 0.015 0 10 0.015 0.01 0.06 0.94 ns 2 10 0.014 0 10 0.016 0.01 0.99 0.33 ns 3 10 0.016 0 10 0.017 0.01 0.24 0.81 ns 4 10 0.012 0 10 0.016 0 1.55 0.14 ns 5 10 0.015 0 10 0.015 0 0.14 0.88 ns 6 10 0.009 0 10 0.012 0 1.23 0.23 ns 7 10 0.01 0 10 0.012 0 0.22 0.82 ns v -s ha pe 1 10 0.006 0 10 0.008 0 1.41 0.17 ns 2 10 0.01 0 10 0.016 0 2.1 0.05 ns 3 10 0.017 0 10 0.016 0 0.39 0.69 ns 4 10 0.018 0 10 0.018 0 0.02 0.98 ns 5 10 0.018 0 10 0.019 0 0.45 0.65 ns 6 10 0.009 0 10 0.012 0 1.62 0.12 ns 7 10 0.01 0 10 0.011 0 0.16 0.87 ns j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 93 table 3: gap space change in reference points in three different palatal vaults shapes (rounded, u-shaped and v-shaped) in nonreinforced and fiber reinforced high impact acrylic denture base studied groups anova no fiber with fiber no. mean difference (mm) f-test p-value no. mean difference (mm) f-test p-value point 1 o-shape 10 0.01 3.41 0.048 sig p<0.05 10 0.01 2.67 0.087 non sig p≥0.05 u-shape 10 0.015 10 0.015 v-shape 10 0.015 10 0.008 point 2 o-shape 10 0.012 0.89 0.42 non sig p>0.05 10 0.013 1.48 0.24 non sig p≥0.05 u-shape 10 0.014 10 0.016 v-shape 10 0.01 10 0.016 point 3 o-shape 10 0.015 0.31 0.73 non sig. p>0.05 10 0.017 1.48 0.98 non sig. p≥0.05 u-shape 10 0.016 10 0.017 v-shape 10 0.017 10 0.016 point4 o-shape 10 0.01 6.05 0 highly sig. p≤0.00 10 0.016 0.01 0.99 non sig. p≥0.05. u-shape 10 0.013 10 0.016 v-shape 10 0.018 10 0.018 point 5 o-shape 10 0.014 1.65 0.21 non sig. p≥0.05. 10 0.015 0.99 0.385 non sig. p≥0.05. u-shape 10 0.015 10 0.015 v-shape 10 0.019 10 0.02 point 6 o-shape 10 0.009 0.006 0.994 non-sig. 10 0.012 0.031 0.97 non-sig. p≥0.05. u-shape 10 0.009 10 0.012 v-shape 10 0.009 10 0.012 point 7 o-shape 10 0.019 9.13 0.001 highly sig. p≤0.00 10 0.015 1.69 0.202 non sig. p≥0.05. u-shape 10 0.01 10 0.011 v-shape 10 0.01 10 0.011 discussion the result demonstrated that fiber impregnation into high impact acrylic resin bases does not affect the magnitude of interfacial gap between the base and the stone cast surface, after 30 days of water storage (table 1). this finding is similar with the statement of polat et al. (18) who reported that the dimensional stability of conventional acrylic resin denture base material not affected with fiber reinforcement.the study also revealed that the smallest dimensional discrepancies were found in the regions corresponding to the crests of the alveolar ridges (point 1 and point 6), these two points have smaller mean difference value than the values found in the median region of the palate (point 1, 3, and 4), and this result agreed with rizzattibarbosa et al. (19), who found that the smallest dimensional discrepancies were found in the regions corresponding to the crests of thealveolar ridges immediately after resin base removal, this result may be due to that palatal region more affected by stress release and from processing pressure on these area. the results of gap-space changes in different palatal vault shape in non-reinforced high impact acrylic denture base revealed significant difference in points (1, 4, and 7) (table 2). it seemed that change in palatal vault shape and difference of the type of tissues in the posterior area near post-dam area may cause a large discrepancy in gap space in high impact acrylic denture base resin this is in agreement with the results of chen et al. (20), who found that an increase in dimensional changes in the posterior area of the palate for most dentures analyzed after 30 days of water storage. the conclusions that can be drawn from this study are: 1. gap-space change of high impact acrylic denture base stored for 30 days in distal water not affected by woven glass fiber reinforcement. 2. topographical changes in maxillary vault shape effect on gap-space dimensional changes of high impact acrylic denture base. 3. topographical changes in maxillary vault shape not effect on gap-space dimensional change of woven glass fiber reinforcement of high impact acrylic denture base. j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 94 references 1. johnston ep, nicholls, smith pe. flexural fatigue of 10 commonly used denture base resin. j prostho dent 1981; 46(5): 478-83. 2. sung-hun k, david cw. the effect of reinforcement with woven e-glass fibers on the impact strength of complete dentures fabricated with high-impact acrylic resin. j prosthetic dent 2004; 91: 274-80. 3. uma mb, patil kg, nagaraj kr, shweth k. comparitive analysis of flexural strength of conventional polymethyl methacrylate resin, high impact resin and glass fiber reinforced resin-an in vitro study. indian j dental sci 2013; 5(4): 77-9. 4. ranganath lm, ganguly r, shet k, rajesh ag. the effect of fiber reinforcement on the dimensional changes of poly methyl methacrylate resin after processing and after immersion in water: an in vitro study. j contemporary dental practice 2011;12(4): 305-17 5. o brain wj. dental materials and their selections. 3rd ed. quintessence publishing co.; 2002 6. mccabe jf, walls awg. applied dental materials. 9th ed. oxford: blackwell publishing; 2008. 7. miessi ac, goiato mc, dos santos dm, dekonsf, okida rc. influence of storage period and effect of different brands of acrylic resin on the dimensional accuracy of the maxillary denture base. braz dental j 2008; 19: 204–8. 8. peroz i, manke p, zimermann e. polymerization shrinking of prosthetic plastic materials in a variety of manufacturing processes. [in german] zwr. 1990; 99: 292-6 9. vallittu pk. flexural strength of acrylic resin polymers reinforced with unidirectional and woven glass fiber. j pros dent 1999; 81(3): 318-26. 10. katja kn, lippo vl, pekka kv. the static strength and modulus of fiber reinforced denture base polymer. dental mater 2005; 21:421-8 11. al-khafaji am. the effect of four different cooling procedures on the dimensional stability of microwaveactivated acrylic resin at different time interval. j bagh coll dentistry 2011; 23(2): 1-5. 12. sykora o, sutow ej. posterior palatal seal adaptation: influence of processing technique, palate shape and immersion. j oral rehabil 1993; 20:19-31. 13. yasir a. influence of different ph of saliva and thermal cycling on the adaptation of different denture base materials. a master thesis, college of dentistry, university of baghdad, 2012. 14. wong dm, cheng ly, chow tw, clark rk. effect of processing method on the dimensional accuracy and water sorption of acrylic resin dentures. j prosthet dent 1999; 81: 300-4 15. rafael l.x, marcelo fm, mario ac, simonides c. influence of the deflasking delay time on the displacements of maxillary denture teeth. j appl oral sci 2003;11(4): 332-6 16. chung-jl, sung-bb, ji-young b and hae-h l. comparative adaptation accuracy of acrylic denture bases evaluated by two different methods. dental mater j 2010; 29(4): 411–7. 17. shadi elb, klaus l, abdulaziz s, sandra fl, matthias k. linear and volumetric dimensional changes of injection-molded pmma denture base resins. dental mater 2013; 29: 1091-7 18. polat tn, karacaer o, tezvergil a, lassila lv, vallittu pk. water sorption, solubility and dimensional changes of denture base polymers reinforced with short glass fibers. j biomater appl 2003; 17: 321-35. 19. rizzatti-barbosa cm, machado c, joia fa, dos santos srl. a method to reduce tooth movement of complete dentures during microwave irradiation processing. j prosth dent 2005; 94: 301-2. 20. chen jc, lacefield wr, castle berry dj. effect of denture thickness and curing cycle on the dimensional stability of acrylic resin denture bases. dental mater 1988; 4: 20-4. maisaa final.doc j bagh college dentistry vol. 26(3), september 2014 salivary c-reactive orthodontics, pedodontics and preventive dentistry 138 salivary creactive protein in relation to periodontal health among a group of patients with rheumatoid arthritis in iraq maisaa i. abdul qadir, b.d.s, h.d.d. (1) athraa m. al-waheb, b.d.s., m.sc. (2) abstract background: rheumatoid arthritis is a chronic destructive inflammatory disease associated with destruction of joint connective tissues and bones, affecting 0.5%–1% of the population worldwide reporting higher prevalence of periodontitis among rheumatoid arthritis patients. the purpose of this study is to estimate level of salivary c-reactive protein in relation to the occurrence and severity of the periodontal disease and other oral parameters among group of patients with rheumatoid arthritis material and methods: fifty women patients with rheumatoid arthritis; twenty five on methotrexate treatment and twenty five on combination treatment of methotrexate and etanercept selected as study groups with an age range (30-40) years old and twenty five gender, age and body mass index matched healthy looking persons were selected as control. the diagnosis and recording of periodontal condition recorded through the application of community periodontal index according to who1997.collection of unstimulated salivary samples was carried out under standard conditions, in addition to estimation of salivary c-reactive protein. results: regarding count of sextants with community periodontal index, median count of sextant with cpi-score 0 was highest among controls (2) and lowest among both rheumatoid arthritis cases (0).the median count of sextant with cpi-score 3 was lowest among controls (0) and highest among both ra cases (2) and the difference observed in median count of sextant with cpi-score 3 between three groups was statistically significant (p< 0.01).the mean rank of salivary c-reactive protein was highest among controls 39.7mg/l however, the difference was not significant between three groups (p>0.05). conclusion: the results of the current research revealed that periodontal diseases were higher among rheumatoid arthritis patients without impact of both treatments on periodontal health without significant role of salivary creactive protein clinically in assessment of disease activity. key words: rheumatoid arthritis, salivary c-reactive protein, community periodontal index. (j bagh coll dentistry 2014; 26(3):138-143). introduction rheumatoid arthritis (ra) is a chronic systemic autoimmune inflammatory disease that affects all ethnic groups throughout the world. females are 2.5 times more likely to be affected than males because men may be protected by hormonal factors and require a stronger genetic component to develop disease (1,2). a prevalence survey for rheumatoid arthritis in iraq was carried out during the summer of 1975 and definite rheumatoid arthritis was observed in 1 % of the 6999 individuals studied (3). periodontal diseases (pd) are the second most common oral diseases next to dental caries, they are considered to be inflammatory disorder that damages tissue through the complex interaction between perio-pathogens and the host defense systems (4,5). periodontitis is one of common oral manifestation of ra, evidence that individuals suffering from ra are more likely to experience periodontitis was found by several studies (6-8). periodontitis and ra are both chronic destructive inflammatory disorders and result from deregulation of the host inflammatory response (9). (1)m.sc. student department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. corgel et al. (10) reported thatinflammatory periodontal diseases exhibit an association with ra andthe effective treatment of periodontal infections is important to achieve oral health goals, as well as to reduce the systemic risks of chronic local inflammation and bacteremias. c reactive protein (crp) is a liver-produced, acutephase reactant; that serves as a systemic marker of inflammation; the name is derived due to the ability of the crp to react with c-polysaccharide isolated from pneumococcal cell walls (11); its levels can be used to monitor patients with overwhelming infections, and elevated crp levels have been demonstrated in persons with ischemia and myocardial infarction (12). alsopersistent elevations in crp are seen in chronic inflammatory states such as active ra, pulmonary tuberculosis, or extensive malignant disease (13). periodontal disease, being a low grade inflammatory disease of the tooth supporting structures, may increase blood levels of inflammatory markers including il-6 and crp (14). al-ghurabei found a significant elevation of mean serum level of high sensitive crp (hscrp) with periodontitis and hs-crp was showed significant positive correlation with each of probing pocket depth (ppd), clinical attachment j bagh college dentistry vol. 26(3), september 2014 salivary c-reactive orthodontics, pedodontics and preventive dentistry 139 loss (cal) and bleeding on probing (bop) among group of iraqi patients (15). slade et al. found an association between extensive periodontal disease and bmi with increased crp levels in otherwise healthy, middle-aged adults, suggesting the need for medical and dental diagnoses when evaluating sources of acute-phase response in some patients (12). saliva is a body fluid, its role as a diagnostic tool has advanced exponentially over the past decade assaliva sampling is safe for both operator and patient, making saliva possible to monitor several biomarkers when blood sampling is not available (16,17). components within saliva may provide additional clues on systemic health conditions. besides, the development of new technologies may promote a wider use of salivary assays in the near future (18). yet, no previous iraqi study could be found that investigates the salivary levels c-reactive protein and its relation to periodontal health among rheumatoid arthritis patients, for this research designed. materials and methods approval was achieved from the ministry of health in iraq for examining the patients with rheumatoid arthritis and collecting samples, in addition to that, the objectives of the study was explained for each participant. the study group composed of fifty ra women patients, with an age range (30-40) years. they were diagnosed clinically, by rheumatology specialist as rheumatoid arthritis depending on the seven criteria of the american rheumatism association with assessment of disease activity depending on disease activity score 28 (das28), they were divided in to two subdivisions groups: the first group (twenty five) under conventional treatment disease-modifying anti-rheumatic drugs dmard (methotrexate mtx) and the second group (twenty five) under combination treatment with anti-tnf-α (etanercept) and dmards (mtx). they were attending baghdad teaching hospital for their treatment. the control group composed of twenty five subjects and they wereapparently healthy according to their medical history matching with age, gender and body mass index bmi of the study group.the disease activity score 28 was calculated with the following equation using esr: das 28 = (0.56 × √tjc) + (0.28 × √sjc) + (0.70 × logn esr) + (0.014 × pga).esr = erythrocyte sedimentation rate.gas = global arthritis score, logn = log-normal, sjc = swollen joint count of 28 joints, tjc = tender joint count of 28 jointspga= patient global assessment. height and weight were determined with the subjects wearing light clothing without shoes using height and weight measurement mechanical scale. the body mass index (bmi) was calculated as (body weight/height 2) (kg/m2). the periodontal status was assessed by using specially designed light weight community periodontal index probe. the community periodontal indexdivide mouth into sextants defined by tooth numbers: (18-14), (13-23), (2428), (38-34), (33-43) and (44-48)with 10 index teeth(17,16,11,26,27,47,46,31,36,37), examination of four surfaces ofthe index teeth, and/or all remaining teeth in a sextant where there are no index teeth, was probed and the highest score was recordedfollowing the criteria of community periodontal index 1997.aspecific measure for periodontitis; plaque index was assessed (silness and loe 1964).the whole unstimulated salivary samples was collected for five minutes from the study and control groups and was performed under standardized conditions according to the instructions cited by tenovuo and lagerlöf (19).the salivary samples were then taken to the laboratory for biochemical analysis and centrifuged at 3000 r.p.m. for 10 minutes. the clear supernatant was separated by micropipette and was stored at (20°c) in a deep freeze and further detection of the crp presence in saliva was done by (huma tex crp). crp determination is based on the immunological reaction between human c-reactive protein of a patient specimen and the corresponding antihuman crp antibodies bound to latex particles, the positive reaction is indicated by a distinctly visible agglutination of the latex particles; positive reaction meaning that a content of crp in the sample equal to or greater than 6 mg/1. samples with positive results in the screening test were retested in the titration test. samples diluted with glycine-nacl buffer (gbs) ((ref 40037)) according to manufacture criteria of the kit, the titer read in the last dilution step with visible agglutination and multiplied the titer with the conversion factor 6 getting the result in mg/l. inter and intra examiner calibrations were performed to obtain the most critical consistency of diagnostic criteria.the results were analyzed using paired t-test and there were no significant differences (p<0.05) between the first and second observation of inter examiner calibration. statistical analysis data were translated into a computerized database structure. the database was examined for errors using range and logical data cleaning methods, and inconsistencies were remedied. an expert statistical advice was sought for. statistical analyses were done using spss j bagh college dentistry vol. 26(3), september 2014 salivary c-reactive orthodontics, pedodontics and preventive dentistry 140 version 20 computer software (statistical package for social sciences). compliance of quantitative random variables with gaussian curve (normal distribution) was analyzed using the kolmogorov-smirnov test. the correlation coefficient tests between the variables were done by using spearman’s rank linear correlation coefficient.p value less than 0.05 and 0.01 was considered statistically significant. results the study and control groups were comparable in age and body structure (table1).the mean values in addition to standard deviation and p values measured by the least significant difference (lsd) in mean of plaque index among study and control groups demonstrated in table (2).the mean plaque index was highest among ra cases on mtx treatment (1.9) and lowest among controls (1.1). the difference observed in mean plaque index between three groups was statistically significant. the mean plaque index was significantly lower (1.1) in controls compared to both ra on etanercept and ra on mtx (1.7 and 1.9 respectively).table (3) illustrates the median, mean rank and p (mann-whitney) for difference of sextants with cpi scores (0, 1, 2, 3 and 4) among study and control groups.the median count of sextant with cpi-score 0 was highest among controls (2) and lowest among both ra cases (0). the difference observed in median count of sextant with cpi-score 0 between three groups was statistically significant. the median count of sextant with cpi-score 0 was significantly higher (2) among controls compared to both ra on etanercept and ra on mtx (0 and 0 respectively).mean rank of sextants with cpi score 1 was obviously highest among ra cases on mtx (40.7) followed by ra cases on etanercept (37.8) and lowest among controls (35.5). the differences observed however, failed to reach the level of statistical significance.mean rank of sextants with cpiscore 2 was obviously highest among ra cases on etanercept (40.6) followed by ra cases on mtx (36.8) and lowest among controls (36.6). the differences observed however, failed to reach the level of statistical significance.the median count of sextant with cpi-score 3 was lowest among controls (0) and highest among both ra cases (2). the difference observed in median count of sextant with cpi-score 3 between three groups was statistically significant. the median count of sextant with cpi-score 3 was significantly higher among both ra on etanercept and ra on mtx (2 and 2 respectively) compared to controls (0). mean rank of sextants with cpiscore 4 was obviously highest among ra cases on etanercept (39.5) followed by controls (38.0) and lowest ra on mtx (36.5). the differences observed however, failed to reach the level of statistical significance.table (4) illustrates the difference in median and mean rank of salivary crp and between the two ra cases groups and control.mean rank of salivary crp was obviously highest among controls (39.7 mg/1) followed by ra cases on mtx (38.6 mg/1) and lowest ra cases on etanercept (35.7 mg/1). the differences observed however, failed to reach the level of statistical significance.table (5) clarifies the difference in median and mean rank of salivary crp between ra cases with high disease activity (das=5.1+) and those with low disease activity. there was statistically not significant difference between positive and negative of high disease activity in salivary crp.table (6) demonstrates the correlations coefficient between count of sextants with cpiscores and salivary crp for ra cases. there was weak and not significant linear correlation among count of sextants with cpi-scores and salivary crp for ra cases and in all direction of relation. table 1: age and body mass index among study groups. age in years apparently healthy controls n=25 rheumatoid arthritis treated with methotrexate n=25 rheumatoid arthritis treated with etanercept n=25 p value range (30-40) (30-40) (30-40) (ns) mean 33.8 34.1 35.8 sd 3.2 3.78 3.57 bmi (kg/m2) (ns) range (18.3-38.6) (16.9-44.4) (17.3-45) mean 28.4 30.1 28.5 sd 5.66 7.7 5.73 * d.f (between groups/within groups) = 2/72. j bagh college dentistry vol. 26(3), september 2014 salivary c-reactive orthodontics, pedodontics and preventive dentistry 141 table 2: comparison of mean plaque index among three groups (control, ra on mtx and ra on etanercept) variable control group (mean ±sd) n=25 methorexate group (mean ±sd) n=25 etanercept group (mean ±sd) n=25 p1 control + methotrxate p2 control + etanercept p3 methotrxate + etanercept f value p value for difference between 3 groups plaque index 1.1±0.81 1.9±0.78 1.7±0.73 < 0.001 0.007 0.46(ns) 6.919 0.002 * d.f (between groups/within groups) = 2/72. table 3: the difference in: median and mean rank of sextants with cpi-scores (0, 1, 2, 3 and 4) between the two ra cases groups and control group. count of sextant with cpi control group median (mean rank). n=25 methotrexate group median (mean rank). n=25 etanercept group median (mean rank). n=25 p1 (mannwtiney) control + mtx p2 (mannwtiney) control + etanercept p3 (mannwtiney) mtx + etanercept p value for difference between 3 groups score 0 2 (53.4) 0 (31.8) 0(28.8) <0.001 <0.001 (ns) <0.001 score 1 2 (35.5) 2 (40.7) 2(37.8) ** ** ** (ns) score 2 1 (36.6) 1 (36.8) 1(40.6) ** ** ** (ns) score 3 0 (23.6) 2 (43.1) 2(47.2) <0.001 <0.001 (ns) <0.001 score 4 0 (38.0) 0 (36.5) 0(39.5) ** ** ** (ns) ** not calculated, because the overall p values for difference between the three groups not reach the level of statistically significance. table 4: the difference in median and mean rank of salivary crp between two ra cases groups and control salivary crp (mg/1) apparently healthy controls n=25 ra treated with methotrexate n=25 ra treated etanercept n=25 p value range (0-48) (0-192) (0-48) (ns) median 0 0 0 mean rank 39.7 38.6 35.7 inter-quartile range (0-0) (0-0) (0-0) table 5: correlation coefficient between count of sextants with cpi-scores and salivary crp for ra cases variable linear correlation coefficient salivary crp (mg/l) count of sextants with cpi-score 0 r 0.083 p (ns) count of sextants with cpi-score 1 r 0.075 p (ns) count of sextants with cpi-score 2 r 0.161 p (ns) count of sextants with cpi-score 3 r 0.06 p (ns) count of sextants with cpi-score 4 r 0.089 p (ns) table 6: correlation coefficient between salivary crp with disease activity score among ra cases variables linear correlation coefficient salivary leptin(ng/ml) salivary crp(mg/l) disease activity score salivary crp (mg/l) r 0.242 0.004 p (ns) (ns) j bagh college dentistry vol. 26(3), september 2014 salivary c-reactive orthodontics, pedodontics and preventive dentistry 142 discussion rheumatoid arthritis (ra) is a common chronic systemic, inflammatory disease affecting the adult population; affected individuals experience significant morbidity, including loss of function, joint destruction, and permanent deformity, and have higher mortality than the general population (20). in recent years, studies reported remarkable epidemiological and pathological relationships between periodontal diseases and rheumatic diseases, especially rheumatoid arthritis (7,8). in present study the mean plaque index was significantly lower in controls compared to both ra on etanercept and ra on mtx. the results of current study come in agreement with findings obtained by recent iraqi study carried out by mahmood et al. in 2012, as plaque index differed significantly between ra (higher) patients and control (lower). the stiffness of hands muscles to achieve good oral hygiene among ra patients and changing in the life style of ra patients, as hands muscle function reduces leading to improper oral hygiene mechanism may explain elevation in plaque index among ra cases, also psychological well-being of patients with ra; they are more likely to suffer from anxiety, depression and low self-esteem which may affect their proper oral hygiene. in terms of periodontal diseases among the study and control groups, the community periodontal index used in which the median count for each score count the number of sextants containing that score only and then present the median for the group. the present study was found that the median count of sextant with cpi-score 0 was significantly higher among controls compared to both ra on etanercept and ra on mtx. gingival inflammation was obviously highest among ra cases on mtx (40.7) followed by ra cases on etanercept (37.8) and lowest among controls (35.5), but statistically not significant. although the prevalence of dental plaque was higher among study groups, gingival bleeding was not different between study and control groups. these results come in agreement with results obtained from previous studies (22, 23). the accepted explanation for these results that the chronic use (prolonged and continuous) of antiinflammatory drugs; non steroid antiinflammatory drugs (nsaids) and steroidal anti-inflammatory drugs (saids) which are used by majority of ra patients and cannot be excluded individuals who use these drugs may modulate plaque-associated gingivitis, however, results of present study are contradict findings of other studies regarding gingival bleeding and gingival inflammation which reported elevation among ra patients and explained by higher plaque index as a causative factor for gingival inflammation (24), this variation in the results may related to difference in age, type of treatment and index use for evaluation of gingival condition. the periodontal pocket is one of the most important clinical features of periodontal disease (25). pocket depth (4-5 mm) was evaluated in this study to be statistically significant higher among ra cases (both on mtx and etanercept) compared with healthy controls, these results come to confirm findings obtained from several studies; where most patients with ra study showed moderate-to-severe periodontitis (26) and also support the concept that patients with longstanding rheumatoid arthritis have substantially increased periodontal disease compared to healthy subjects. in the current study effect of both treatments (methotrexate and etanercept) on periodontal health was evaluated revealing no significant difference between two treatments regarding effect on periodontal health, this is consistent with findings of a previous study in ra subjects that anti-tnf-α therapy without periodontal treatment has no significant effect on the periodontal condition (27). in the same study the methotrexate effect on periodontal health was evaluated and also has no effect on periodontal condition without periodontal treatment confirming the inter-relationship between ra and pd. estimation levels of salivary biomarker crp among ra patients was one of aims of current study, as quantitative changes of specific salivary biomarkers could have significance in the diagnosis and management of both oral and systemic diseases; levels of salivary crp in present study reveals no significant difference was observed between the two ra study groups (mtx and etanercept) and controls (38.6 mg/l, 35.7 mg/l and 39.7 mg/l) respectively. serum crp in rheumatoid arthritis patients has been evaluated extensively but unfortunately, there was no study able to be found estimates its level in saliva. this non-significant difference between study and control groups may relate to effect of treatment, since hochberg et al.in 2011 reported that mtx rapidly decrease serum crp with the minimum value being noted on day 3 after onceweekly dosing and su et al. in 2009 demonstrated significant improvements in serum crp values at the end of the first 3 months treatment with etanercept and as saliva is mirror of the body reflects its concentration in serum, this may be an acceptable explanation. this study reveals weak correlation of salivary crp with das 28 among j bagh college dentistry vol. 26(3), september 2014 salivary c-reactive orthodontics, pedodontics and preventive dentistry 143 both groups of ra patients, this agree with keenan et al. (28) who concluded from his study regarding esrand crp values in ra andwhether or not they were correlated with outcomes in raby measures of disease activity;the study revealed that they were weakly correlated with disease activity measures.in conclusion periodontal destruction represented in pocket depth was statistically significant higher among both ra cases (on mtx and combination of mtx and etanercept) compared with healthy controls concluded severity of periodontal disease and that both treatments have no impact on periodontal destruction without periodontaltreatment among patients with ra, suggesting especial periodontal treatment and preventive programs, alsoanother outcome of current study that salivary crp using this assay is of low importance and not meaningfulclinically to assess the activity of the disease suggesting more specific and sensitive assays such as salivary high sensitivity crp assay. references 1. ollier w, harrison b, symmons d. what is the natural history of rheumatoid arthritis? best practclinrheumatol 2001; 15(1): 27-48. 2. klippel j, stone j, crofford l, white p. primer on the rheumatic disease. 13th ed. new york: springer; 2008. 3. al-rawi z, al-azzawi a, al-ajilli f, al-wakil r. rheumatoid arthritis in population samples in iraq. annals of the rheumatic diseases 1978; 37: 73-5. 4. detert j, pischon n, burmester g, buttgereit f. pathogenesis of periodontitis in rheumatic disease. z rheumatol 2010; 69:109-12. 5. khashu h, baiju c, bansal s, chhillar a. salivary biomarkers: a periodontal overview. j oral health comm dent 2012; 6(1): 28-33. 6. joseph r, rajappan s, nath s, paul b. association between chronic periodontitis and rheumatoid arthritis. rheumatol int 2013; 33:103–9. (ivsl). 7. detert j, pischon n, burmester g, buttgereit f. the association between rheumatoid arthritis and periodontal disease. arthritis research & therapy. 2010; 12: 218. 8. abdelsalam s, hashim n, elsalamabi e, gismalla b. periodontal status of rheumatoid arthritis patients in khartoum state. bmc research notes 2011; 4: 460. 9. berthelot j and le goff b.rheumatoid arthritis and periodontal disease. joint bone spine 2010; 77: 53741. 10. corgel j, pucher j, rethman m, reynolds m. state of the science: chronic periodontitis and systemic health. j evid base dent pract 2012; 1: 20-8. 11. pepys m, gideon m. hirschfield c-reactive protein: a critical update. j clin invest 2003; 111: 1805-12. 12. slade g, ghezz e, heiss g, beck j, riche e, offenbacher s. relationship between periodontal disease and creactive protein among adults in the atherosclerosis risk in communities study. arch intern med 2003; 163(10):1172-9. 13. firestein g, budd r, gabriel r, mcinnes i, o’dell j. kelley’s textbook of rheumatology. 9th ed. elsevier: 2013. 14. vidal f, figueredo c, cordovil i. periodontal therapy reduces plasma levels of interleukin-6, c-reactive protein, and fibrinogen in patients with severe periodontitis and refractory arterial hypertension. j periodontol 2009; 80(5): 786-91. 15. al-ghurabei b. evaluation of serum anti-cardiolipin antibody, hs-crp and il-6 levels in chronic periodontitis as possible risk factors for cardiovascular diseases. j bagh coll dent 2012; 24(2):161-5. 16. streckfus c, bigler l. saliva as a diagnostic fluid. oral dis 2002; 8: 69-76. 17. castagnola m, picciotti t, messana i, fanali c, fiorita a, cabras t, calò l, pisano e, passali g, iavarone f, paludetti g, scarano e. potential applications of human saliva as diagnostic fluid. acta otorhinolaryngologica italica 2011; 31: 34757. 18. tremblay m, loucif y, methot j, brisson d, gaudet d. salivary ph as a marker of plasma adiponectin concentration in women. d and ms 2012; 4: 4. 19. tenovou j, legerlöf f. saliva in: thylstup a, fejerskov o (eds). text book of clinical cariology. 2nd ed. copenhagen: munksgaard; 1996. pp.17-43. 20. heijde d, klareskog l, valverde v, codreanu c, bolosiu h, gomes j, molina j, wajdula j, pedersen r, fatenejad s. comparison of etanercept and methotrexate, alone and combined, in the treatment of rheumatoid arthritis. arthritis & rheumatism 2006; 54(4): 1063–74. 21. blaizot a, monsarrat p, constantin a, vergnes n, de grado f, nabet c, cantagrel a, sixou m. oral health-related quality of life among outpatients with rheumatoid arthritis. int dent j 2013; 63(3):145-53. 22. ishi p, bertolo b, rossa j, kirkwood l, onofre a. periodontal condition in patients with rheumatoid arthritis. braz oral res 2008; 22(1): 72-7. 23. abinaya p, kumar r. prevalence of periodontal disease among individuals with rheumatoid arthritis. jiads 2010; 1(4): 16-23. 24. mahmood a, shukri m. assessment of salivary elements (zinc, copper and magnesium) among groups of patients with rheumatoid arthritis and chronic periodontitis and its correlation to periodontal health status. j bagh coll dent 2012; 24(3): 87-92. 25. newman m, takei h, klokkevold p, carranza f. carranza’s clinical periodontology.10th ed. elsevier; 2010. 26. ziebolz d, pabel s, lange k, krohn-grimberghe b, hornecker e, mausberg r.clinical periodontal and microbiologic parameters in patients with rheumatoid arthritis. j periodontol 2011; 82(10): 1424-32. 27. ortiz p, bissada n, askari a. periodontal therapy reduces the severity of active rheumatoid arthritis in patients treated with or without tumor necrosis factor inhibitors. j periodontal 2009; 80(4): 535-40. 28. keenan r, swearingen c, yazici y. erythrocyte sedimentation rate and c-reactive protein levels are poorly correlated with clinical measures of disease activityin rheumatoid arthritis, systemic lupus erythematosus and osteoarthritis patients. clinical and experimental rheumatol 2008; 26: 814-9. dropbox 15 jihan 80-85.pdf simplify your life rasha.doc j bagh college dentistry vol. 26(4), december 2014 assessment of bone oral diagnosis 126 assessment of bone density after six months from dental implants placement using computed tomography resha j. al-sudani, b.d.s., m.sc. (1) abstract background: determination of local bone mineral density (bmd) immediately after implant insertion play an important role in implant success rate, may offer comprehensive description of the bone, and give enough information to the surgeon prior to implant insertion and at follow up status. the aim of the present study is to evaluate the changes of local bone density in the dental implant recipient sites by using computerized tomography. material and method: the sample consisted of (20) dental implants recipient sites, bone density assessment was done twice, immediately after implants insertion and after six months. results: the mean hu of the bone around the implant insertion site, immediately after implant placement was 552.28 hu, and increased to761.33hu after six months. according to gender, with females, it was 539,54hu, and increased to 765.65hu after six months from implant insertion while with males, it was 565.02hu, and increased to 757.02hu after six months from implant insertion. conclusion: there was an increased in bone density around dental implant by time with non-significant differences according to the gender. keywords: computed tomography, dental implants, hounsfield unit. (j bagh coll dentistry 2014; 26(4):126-128). الملخص إن الھدف من ھذه الدراسة السریریة الحالیة ھو تحدید .من االمور المھمة جدا في نجاح زراعة االسنان غرزالزرعات السنیةتحدید كثافة العظام قبل وبعد: الخلفیة .كثافة العظام بعد عملیة زراعة االسنان لمنطقة ما حول الزرعھفي مختلف مناطق الفكین العلوي سفیلدباستخدام األشعة المقطعیة ، ازرعة بوحدة الھاون 20كثافة العظام ل تم قیاس متوسط : طرق البحث . اشھر من زراعة االسنان 6بعد الزراعة مباشرة وبعد مرور .والسفلي وحدة 761.33نھا ازدادت لتصل الى حیث ا, ثافةوحدة قیاس الك552.28متوسط كثافة العظم حول الزرعة السنیة مباشرة بعد غرز الزرعة كان ما یعادل :النتائج وحدة اما 757.02وحدة وبعد مرورستة اشھر ازدادت لتصل 565.02معدل كثافة العظم بعد غرز الزرعة مباشرة عند الرجال , بعد ستة اشھر من غرز الزرعة .وحدة 765.65وحدة مباشرة بعد الغرز وبعد ستة اشھر ازدادت لتصل 539.54عند النساء .بفارق غیر محسوس احصائیا اشھر من زراعة االسنان وتكون نسبة الزیادة متساویة عند الرجال والنساء 6كثافة العظم تزداد بعد مرور : ستنتاجاال introduction it is important to evaluate the statement of jaw bone at the potential implant site, several methods to measure the bone dimension and density, determination of bone density may offer comprehensive description of the bone, its beneficial to give enough information to the surgeon prior to implant insertion and at follow up status. quantitative computed tomography is used to determine bone density (1). the internal structure of bone is described in terms of quality or density, which reflects a number of biomechanical properties, such as strength and modulus of elasticity. the external and internal architecture of bone controls virtually every facet of the practice of implant dentistry. the density of available bone in an edentulous site is a determining factor in treatment planning, implant design, surgical approach, healing time, and initial progressive bone loading during prosthetic reconstruction. this study presents the aspects of bone density related to overall planning of implant prosthesis (2). an appreciation of bone density and its relation to oral implantology has existed for more than 25 years. bone density was classified into three categories: class i bone structure: this ideal (1)assisstant lecturer. department of oral diagnosis, college of dentistry, university of baghdad bone type consists of evenly spaced trabeculae with small cancellated spaces. class ii bone structure: the bone has slightly larger cancellated spaces with less uniformity of the osseous pattern. class iii bone structure: large marrow-filled spaces exist between bone trabeculae (3). the amount of crestal bone loss also has been related to bone density, and further supports a different protocol for soft bone. several researches proposed four bone density groups independent of the regions of the jaws, based on macroscopic cortical and trabecular bone characteristics. the regions of the jaws with similar densities were often consistent. suggested treatment plans, implant design, surgical protocol, healing, and progressive loading time spans have been described for each bone density type. these four macroscopic structures of bone may be arranged from the least dense to the densest, these four increasing macroscopic densities constitute four bone categories described by misch (d1, d2, d3, and d4) located in the edentulous areas of the maxilla and mandible (4). hu value was used to assess the bone density on the implants site, and the standard value of jaw bone density varies from one individual to other (5). j bagh college dentistry vol. 26(4), december 2014 assessment of bone oral diagnosis 127 table 1: bone density classification scheme (8) bone density description typical anatomical location d1 dense cortical anterior mandible d2 porous cortical and coarse trabecular anterior mandible posterior mandible anterior maxilla d3 porous cortical (thin) and fine trabecular anterior maxilla posterior mandible d4 fine trabecular posterior maxilla materials and methods this study was performed in baghdad from december 2012 to february 2014, the patients were selected from different centers of implantology in baghdad. the sample consisted of twelve patients with twenty implants, ten in male and ten in female in premolar and molar region of upper and lower jaws. ct scan was taken immediately after implant insertion to measure the bone density by using hu around dental implant, after six months after dental implant placement, another ct scan was performed, and bone density in hu unit was measured around the implant site to detect the osseointegration. results as shown in table 2, the mean hu of the bone around the implant insertion site, the mean hu of jaw bone at immediate implant placement was 552.28 hu, and increased to 761.33hu after six months from implant insertion, and they showed statically significant differences (p≤0.05). in table 3, the mean of hu according to the gender, was 539,54hu in females, and increased to 765.65hu after six months from implant insertion, which is statistically significant (p≤0.05). while in males it was 565.02hu, and increased 757.02hu after six months from implant insertion, which is also statistically significant (p≤0.05). table 2: bone density in hounsfield unit around the area of implant placement at immediate implant placement and after six months mean ±sd at immediate implant placement 552.28±104.5 six months from implant insertion 761.33±156.7 table 3: bone density in hounsfield unit according to the gender on the area of implant placement at immediate implant placement and after six months female male immediate implant placement and 539.54±137.2 565.02±97.5 six months from implant insertion 765.65±198.7 757.02±153.6 discussion this study revealed that the density of jaw bone around dental implant increased with osseointegration, with the same rate in males and females using hu that measured by msct which is important in the measurement of bone density. table2 shows the differences of bone density around the implant immediately after insertion and after six months from the surgery. mean hu value was increased significantly after implant placement. this result reveals that the density of the jaw bone around the dental implant increased, this is in agreement with han and park (6) when approved that there calcified tissue around implant surface by time. table 3 shows the differences of bone density according to the gender on the area of implant placement immediately and after six months from the surgery. mean hu value show non-significant increasing between male and female, this study revealed that the density of bone increased in both male and female in the same rate. this study also agreed with barunawarty, in his study approved that bone density increased around dental implant after placement of dental implants (7). in conclusion; ct-scan could be used to assess the changes of bone density around dental implants. the bone density increased with osseointegration, the increasing rate of bone density could be determined by quality of jaw bone before, and after implant insertion. reffernces 1. homolka p, beer a, birkfellner w, nowotny r, tschabitscher m, et al. bone mineral density measurement with dental quantitative ct prior to dental implant placement in cadaver mandibles: pilot study. radiol 2002; 224: 247-52. 2. misch ce, qu z, bidez mw. mechanical properties of trabecular bone in the human mandible implications of dental implant treatment planning and surgical placement. j oral maxillofac surg 1999: 57:700-6. 3. linkow li, chercheve r. theories and techniques of oral implantology. vol.1. st. louis: mosby: 1970. 4. misch ce, bidez mw, sharawy m. a bioengineered implant for a predetermined bone cellular response to j bagh college dentistry vol. 26(4), december 2014 assessment of bone oral diagnosis 128 loading forces: a literature review and case report, j periodontol 2001; 72:1276-86. 5. rho jy, hobathomc, ashman rb. relation of mechanical properties to density and ct number in human bone. med eng phys 1995; 17: 347-55. 6. hn tj, park kb. surgical aspect of dental implants. in: newman mg, takei hh, carranza fa (eds). carranza's clinical periodontology. 9th ed. philadelphia: wb saunders; 2002. p.898 7. barunawarty y. assessment of the increased calcification of jaw bone with ct-scan after dental implant placement. imaging sci dent 2011; 41(2): 5962. 8. micsh ce. contemporary implant dentistry. 3rd ed. mosby: 2008. 8.sattar f.doc j bagh college dentistry vol. 25(1), march 2013 an in vitro evaluation restorative dentistry 43 an in vitro evaluation of fit of the crowns fabricated by zirconium oxide-based ceramic cad/cam systems, before and after porcelain firing cycles and after glaze cycles sattar j. a. hmedat, b.d.s. (1) adel f. ibraheem, b.d.s., m.sc. (2) abstarct background: the objective of this in vitro study was to evaluate the vertical marginal fit of crowns fabricated with zro2 cad/cam, before and after porcelain firing cycles and after glaze cycles. materials and methods: an acrylic resin model of a left maxillary first molar was prepared and duplicated to have nickel-chromium master die. ten die stone dies were sent to the cad/cam (amann girrbach) for crowns fabrication. marginal gaps along vertical planes were measured at four indentations at the (mid mesial, mid distal, mid buccal, mid palatal) before (time 0) and after porcelain firing cycles (time 1) and after glaze cycles (time 2) using a light microscope at a magnification of ×100. one way anova lsd tests were performed to determine whether the mean and standard deviation of sub group time 2. results: the mean values of the zro2 cad/cam time 0 were (6.77μm), time 1(8.75μm) and time 2(10.62 μm). one way anova test revealed highly statistical significance(p<0.01). lsd test results showed that there is highly significant difference between time (0) and time (2), while there is no any significant difference between time (0) and time (1), and between time (1) and time (2). conclusions: within the limitations of this study, it was concluded that the zro2 cad/cam demonstrated acceptable marginal fit; the porcelain firing and the glaze firing cycles affected the marginal gap. key words: vertical marginal fit, cad/cam, and zirconium oxide. (j bagh coll dentistry 2013; 25(1):43-48). introduction with a growing awareness of esthetics and biocompatibility, patients increasingly request metal-free solutions(1). due to the successful use of all-ceramic crowns both in the anterior and posterior segments (2), and with the introduction of advanced dental technology and high-strength ceramic materials, all-ceramic systems may become a viable treatment option even for extended fixed partial dentures (fpds). such restorative all-ceramic systems must fulfil biomechanical requirements and provide longevity similar to metal-ceramic restorations (3) while providing enhanced esthetics (4). zirconia, which is a polycrystalline material without a glassy matrix and is partly stabilized by yttrium oxide (approximately3 mol%), is an alternative for multiunit frameworks. the use of zirconia ceramics for multiunit fpds has been facilitated by the advent of computer aided design/computer aided manufacturing (cad/cam) systems(5). these allceramic restorations must meet requirements for strength,color stability, and precision of fit for clinical success(6). due to the solubility of luting agents(7), minimizing marginal opening is paramount in decreasing prosthetic failure resulting from caries, plaque and food accumulation, and inflammation of the periodontal tissues (8). (1)m.sc. student in department of conservative, college of dentistry, university of baghdad. (2) professor/chairmen of department of conservative, college of dentistry, university of baghdad, baghdad, iraq. mclean and von fraunhofer in 1971(9) examined more than 1000 crowns after a 5-year period and concluded that a marginal opening of ≤120 μm was clinically acceptable. copy milling and cad-cam systems have gained popularity due to their ease of fabrication, good mechanical properties, and decreased porosity(10). the cad-cam technologies introduced to the dental profession in 1971(11). the most common method to fabricate a zirconia substructure is by cad/cam milling from a solid block. the fully sintered zirconia is milled at a 1:1 ratio, while the partially sintered zirconia is milled 20% to 25% larger than the desired final size due to shrinkage caused by the sintering process. the development of cad/cam technology has focused on precise and consistent manufacturing of zirconia ceramics. cad/ cam technology relies on exact dimensional predictions to compensate for sintering shrinkage, is an economical and reproducible method and in addition, has demonstrated improved marginal fit(12). materials and methods preparation of master die: a dentoform left maxillary first molar was prepared to receive all ceramic crown using a high speed hand piece with air-water coolant, that was adapted to the suspending arm of the modified surveyor in such a way so that the long axis of the bur was paralleled to the long axis of the ivorine tooth, the horizontal arm of the surveyor j bagh college dentistry vol. 25(1), march 2013 an in vitro evaluation restorative dentistry 44 permitted vertical as well as rotational movement around the tooth. the left maxillary first molar was prepared to receive a complete ceramic crown, with the following preparation features; a 90° radial shoulder finish line all around the tooth with (1 mm) depth determined by a digital vernier, a total circumferential axial reduction was about 1.5 mm, and axial taper of 6° using a diamond bur no.(g846r). this bur was selected because it provides a shoulder finishing line; occlusal reduction of about 2mm was performed using a diamond disk bur no.(g818)(13). the prepared dentoform tooth was used as a pattern for construction of the metal master die. the dentoform tooth was then sprued, invested, burned out and casted using nickel-chromium alloy (figure 1). figure 1: finished master die with its acrylic base having seating groove at each corner a block of acrylic resin was then constructed to hold the master die in such a way so that the long axis of the master die lied vertical to the horizontal plane of the acrylic block, and a dental surveyor was used for this purpose. four seating grooves (5mm depth and 3mm base) at each corner of the upper surface of the block were made to be used later as a guide and stopper for the special tray during impression making. a surveyor was used to construct the special tray for the master die. impression procedures: a surveyor was used during the process of impression taking, the master die was fixed to the horizontal table of the surveyor in such a way so that the long axis of the tooth was kept parallel to the long axis of the analyzing rod of the surveyor, the special tray was fixed to the suspending arm of the surveyor through the analyzing rod (previously attached to the tray during its construction) so that a standardized path of insertion and removal of the special tray was obtained. the special tray was coated with poly (vinyl siloxane) adhesive for one hour prior to impression making. the impression was done using heavy and light viscosity poly vinyl siloxane. the special tray was used to obtain 30 impressions. both the heavy and light body impression materials and catalysts were mixed using auto mixing gun. type iv die stone was mixed in a vacuum auto mixer, the impression was poured on the vibrator in accordance with the manufacturer’s instructions, thirty die stones were constructed from thirty impressions. all laboratory procedures were performed by the same operator. zirconia core manufacturing by cad/cam system(group iii): ten zerconia crowns were constructed in the following manner: scanning of the die: scannable liquid (compatible with the scanning device of ceramill inlab), was applied to the die stone to obtain precise scanning picture (figure 2). figure 2: the scaning machine (ceramill,amangirbach,germany). the optical scanner scanned the die models with the help of the ceramill 3d inlab software; three-dimensional images were displayed on the computer monitor, so that all the surfaces and finishing lines were shown clearly (figure 3). j bagh college dentistry vol. 25(1), march 2013 an in vitro evaluation restorative dentistry 45 figure 3: scanning die in the monitor core design: core designing procedure through the software was done with the following features, a minimum wall thickness of the core (1mm), and cement gap should have 0.05 mm thickness, starting at 0.25mm from the margin(14) (figure 4). figure 4: selection of treatment for tooth the copy seen in the final design in the monitor (figure 5). figure 5: completing the core design. after applying the information for the design to the milling centre in software (figure 6), a suitable blank (height and size) was selected from the blank loaded library of the cad-cam system. figure 6: set and adjust the core in the y-tzp blank. the y-tzp blank (zirconium block) was placed in the blank holder and fixed with the screws by the screw key, and the milling process was then started. all those steps were done following the manufacturer instructions of ceramill inlab cad/cam system (amanngirrbach dental systems, germany) (figure 7). figure 7: the blank in the milling machine after the milling procedure had ended the blank was removed from the milling machine and the copy frame separated from the blank by a labrotary hand peice with a fissure bur (figure 8). figure 8: complete milling and the copy removed it from the blank j bagh college dentistry vol. 25(1), march 2013 an in vitro evaluation restorative dentistry 46 colouring and sintering: the copy was given its individual colour by immersing it in the dye solution. sintering was carried out in the ceramill therm hightemperature furnace 1500°c for 9 hours to complete sintering. porcelain veneering cycling: for all three groups, the closing margins were made with a core structure. the veneer started (0.5 mm) thickness at the margin, occlusally 1mm and at middle third about 0.75mm. measurement of the marginal gap: marginal gaps along vertical planes were measured at four indentations on the margin at the midpoint of mesial, distal, buccal and palatal surfaces of the die using a light microscope. the measurements were done at three interval times: 1-(time 0): before porcelain firing. 2-(time 1): after porcelain firing. 3-(time 2): after glazing cycle. a screw loaded holding device following thiab and zakaria, 2007(15) was used during measurements in order to maintain a seating pressure of (13.4n) (16) between the all-ceramic crown and the master metal die during measurements calculation for this purpose. the microscope was calibrated to 0.001mm (1μm) at magnification 100x. and the measurements were done by placing the sample on the microscope stage, which was adjusted until the image of the marginal area was display clearly on the computer monitor, and the digital image of the gaps were then captured. the image was treated with program (image j) which was used to measure the vertical marginal gap between the copy and master die, the program (image j) was used to measure the value in a pixels mark by drawing a line between the finishing line on the die and the copy margin line (figure 9). all digital readings were recorded and converted to (μm) by a magnification factor. figure 9: digital images were captured during the measurement results a total of 480 measurements from cad/cam were recorded at three intervals, time 0 (before) and time 1 (after) porcelain firing cycles and time 2 (after glaze cycles) with 16 measurements per crown at each interval time. on the other hand comparing the results recorded in table (1) showed that the lowest mean value was recorded 6.775 μm in (time 0) subgroup followed by 8.750 μm (time 1) and with height vertical marginal gap value recorded 10.625 μm(time 2). table 1: descriptive statistics of the three groups or three times. sub group n min max mean sd time (0) 10 4.25 10.75 6.775 1.8388 time (1) 10 6.25 11.75 8.750 1.9257 time (2) 10 7.25 14.25 10.625 2.6621 the anova test results showed highly significant differences among the different time subgroups (as shown in table 3). table 2: one wayanova for cad-cam group (time 0, time 1 and time 2) sum of squares mean square f sig. between groups 74.129 37.065 7.844 0.002 within groups 127.588 4.725 h.s. total 201.717 hs:p<0.01(highly significant) the lsd test of results showed that there is highly significant difference between time (0) and time (2), while there is no any significant difference between time (0) and time (1), and between time (1) and time (2) (as shown in table 3). table 3: lsd test between the time subgroups of the cad-cam. (i) var0000 (j) var0000 mean difference (ij) std. error sig. time (0) time (1) -1.90000.97032 .061 time (0) time (2) -3.82500-* .97032 .001 time (1) time (2) -1.92500.97032 .058 discussion in this in vitro study, the zirconium oxidebased ceramic cad/cam systems mean marginal gap (10.62μm) was demonstrated acceptable marginal gaps according to christensen (17); mclean and von fraunhofer (9); suarez et al (18); wolfart et al (19),; quintas et al (20); bindl and j bagh college dentistry vol. 25(1), march 2013 an in vitro evaluation restorative dentistry 47 mörmann,(21); sailer et al (22); iwai et al (23) who suggested that 120 µm should be the highest limit for clinically acceptable marginal discrepancies. the results showed that glazing produced greater marginal gap differences that are statistically highly significant. these results are in agreement with the results of balkaya et al (24) and pak et al (25). marginal gap values reported in the present study also in agreement with those of gonzalo et al (14) who reported that the cad-cam zirconia restoration showed the lowest marginal gap (912 μm). however, these results disagree with the results of pera et al(26); probster et al(27); shearer et al(28); song et al(29); vigolo and fonzi (30) which could be attributed to: the increase in the marginal gap in veneered coping after the body porcelain firing cycles may also be a result of porcelain contamination on the inner surfaces of copings, and reduction in the resilience of the core material and rigidity of the porcelain(31). the difference in thermal expansion coefficient (tec) of the veneering ceramic and the core material leads to pressure tensions during cooling at room temperature which lead to enhancement in bonding strength between the two materials. this bonding strength might affect the marginal fitness, so the marginal fit changes in the veneering stages of the firing cycle could be attributed to (tec) incompatibility of the veneering ceramic used and the core material which lead to stress effect on the marginal fit(32). another explanation of the difference in marginal gap may be explained by the fact that during the porcelain veneering procedure, particles of porcelain melt and gather to fill up voids and the resulting contraction of the porcelain mass causes a compressive force on the coping(33). the deformation of the coping under the stress of contracting porcelain is spread around the whole circumference of the margin. so the literature has suggested certain causes that may be responsible for the distortion such as: porcelain contraction, design and thickness of the core substructure and inadequate support of the core framework during firing(34). the small value of vertical marginal gap attributed to: the creating of an enlarged during designing of the framework before sintering y-tzp blank and milling, to compensate the account shrinkage that associated with sintering to achieve the definitive fit of restoration with its final strength(35). the presintered y-tzp blank have a number that was set in the software during designing of the core that represent the volume of sintering shrinkage, so that the balance between the enlarged machining of the pre sintered y-tzp block and the shrinkage occurring during the sintering process is highly precise, thus creating frameworks with an overall improved marginal gap and high significantly smaller than other system. the cad-cam ceramill system is the supra fine milling of the inner surface that will improve the seating of the coping to the die. effect of die spacer: some authors (grajower, lewinstein(36); hunter, hunter(37), and adriana et al(38)) stated that “adequate die spacing is a more important factor than margin configuration for the accuracy of crown margins”. the greater the internal relief, the less time interval is required for definitive seating, leading to less force required and potentially less strain to all-ceramic margins(39). the other causes of lowest marginal gap of the cad-cam ceramill system was attributed to fewer laboratory steps and predetermined die spacer designed in the software (50 μm thickness) according to some studies, if die spacer was applied to the entire prepared surface except a region of 0.25 μm above the finish line might cause improved marginal fitting of the core (38,40,41). references 1reich s, wichmann m, nkenke e, proeschel p. clinical fit of all-ceramic three-unit fixed partial dentures, generated with three different cad/cam systems. eur j oral sci 2005;113:174-9. 2fradeani m, d'amelio m, redemagni m, corrado m. five-year follow-up with procera all-ceramic crowns. quintes int 2005;36(2):105-13. 3denry il, holloway ja, rosenstiel sf. enhanced chemical strengthening of feldspathic dental porcelain, j dent res 1998; 77: 583. 4raigrodski aj, chiche gj. the safety and efficacy of anterior ceramic fixed partial dentures: a review of the literature. j prosthet dent 2001;86:520-5. 5raigrodski aj, chiche gj, potiket n et al. the efficacy of posterior three-unit zirconium-oxide–based ceramic fixed partial dental prostheses: a prospective clinical pilot study. j prosthet dent 2006; 96: 237-44. 6schwartz nl, whitsett ld, berry tg et al. unserviceable crowns and fixed partial dentures: life span and causes for loss of serviceability. j am dent assoc 1970;81:1395-401. 7schwartz is. a review of methods and techniques to improve the fit of cast restorations. j prosthet dent 1986; 56: 279-83. 8bergenholtz g, cox cf, loesche wj et al. bacterial leakage around dental restorations: its effect on the pulp. j oral path1982; 11:439-50 j bagh college dentistry vol. 25(1), march 2013 an in vitro evaluation restorative dentistry 48 9mclean jw, von fraunhofer ja. the estimation of cement film thickness by an in vivo technique. br dent j 1971;131:107-11. 10gorman cm, mcdevitt we, hill rg. comparison of two heat-pressed all-ceramic dental materials. dent mater 2000;16(6):389-95. 11duret f, jean i, bernard d. cad-cam in dentistry. j amer dent assoc 1988; 117:715-20. 12tinschert j, natt g, hassenpflug s, spiekermann h. status of current cad/cam technology in dental medicine. int j comput dent 2004;92:25-45. 13penwadee l, edwin k, gerard jch, markus bb. comparison of marginal fit between all-porcelain margin versus alumina-supported margin on procera r-alumina crowns, j prosthodont 2009; 18: 162-6. 14gonzalo e, sulrez m.g, serrano b, lozano jl. a comparison of the marginal vertical discrepancies of zirconium and metal ceramic posterior fixed dental prostheses before and after cementation. j prosthet dent 2009;102:378-84. 15subhy ag, zakaria mr. evaluation of the effects of an iraqi phosphate bonded investment and two commercial types on the marginal fitness of porcelainfused-to-metal copings. mostansiria dent j 2005;2(2):183-93. 16thiab ss, zakaria mr. the evaluation of vertical marginal discrepancy induced by using as cast and as received base metal alloys with different mixing ratios for the construction of porcelain fused to metal copings. al-rafidain dent j 2004; 4(1): 10-19. 17christensen gj. marginal fit of gold inlay castings. j prosthet dent 1966; 16(2):297-305. 18suarez mj, gonzalez de villaumbrosia p, pradies gl, lozano jf. comparison of the marginal fit of procera allceram crowns with two finish lines. int j prosthodont 2003;16:229-32. 19wolfart s, wegner sm, al-halabi a, kern m. clinical evaluation of marginal fit of a new experimental allceramic system before and after cementation. int j prosthodont 2003;16:587-92. 20quintas af, oliveira f, bottino ma. vertical marginal discrepancy of ceramic copings with different ceramic materials, finish lines, and luting agents: an in vitro evaluation. j prosthet dent 2004;92:250-7. 21bindl a, mormann wh. an up to 5-year clinical evaluation of posterior in-ceram cad/cam core crowns. int j prosthodont 2002;15(5):451-6. 22sailer i, feher a, filser g, gauckler lj, luthy h, hammerle ch. five-year clinical results of zirconia frameworks for posterior fixed partial dentures. int j prosthodont 2007;20:383-8. 23iwai t, komine f, kobayashi k, saito a, matsumura h. influence of convergence angle and cement space on adaptation of zirconium dioxide ceramic copings. acta odontol scand 2008,66:214-8. 24balkaya mc, cinar a, pamuk s. influence of firing cycles on the margin distortion of 3 all-ceramic crown systems. j prosthet dent 2005;93:346-55. 25pak h s, hanj s,lee j b,kim s h,yangj h. influence of porcelain veneering on the marginal fit of degudent and lava cad/cam zirconia ceramic crowns, j adv prosthodont 2010;2:33-8. 26pera p, gilodi s, bassi f, carossa s. in vitro marginal adaptation of alumina porcelain ceramic crowns. j prosthet dent 1994;72:585-90. 27probster l, geis-gerstorfer j, kirchner e, kanjantra p. in vitro evaluation of a glass-ceramic restorative material. j oral rehabil 1997;24:636-45. 28shearer b, gough mb, setchell dj. influence of marginal configuration and porcelain addition on the fit of in-ceram crowns. biomaterials 1996;17:1891-5. 29song tj. marginal fit of the auro galvano crown system made using the electroforming technique. master thesis, seoul, korea: seoul national university, 2004. 30vigolo p and fonzi f. an in vitro evaluation of fit of zirconium-oxide-based ceramic four-unit fixed partial dentures, generated with three different cad/cam systems, before and after porcelain firing cycles and after glaze cycles j prosthodont 2008;17: 621–6. 31faucher r m, & nicholls j i: distortion related to marginal design in porcelain-fused to-metal restoration. j prosthet dent 1980; 43 (2): 149-55. 32luthardt rg, sandkuhl o, reitz b. zirconia-tzp and alumina-advanced technologies for the manufacturing of single crowns. eur j prosthodont restor dent 1999; 7: 113-9. 33weaver jd, johnson gh, bales dj. marginal adaptation of castable ceramic crowns. j prosthet dent 1991;66:747-53. 34van rensburg f, strating h. evaluation of the marginal integrity of ceramometal restorations: part ii. j prosthet dent, 1984;52(2):210-4. 35strub jr, rekow ed, witkowski s. computer-aided design and fabrication of dental restorations: current systems and future possibilities. j am dent assoc 2006;137:1289-96. 36grajower r, lewinstein i. a mathematical treatise on the fit of crown castings. j prosthet dent 1983;49:66374. 37hunter aj, hunter ar. gingival margins for crowns: a review and discussion. part ii: discrepancies and configurations. j prosthet dent 1990;64:636-42. 38adriana fq, fabiano oliveira, marco ab. vertical marginal discrepancy of ceramic copings with different ceramic materials, finish lines, and luting agents: an in vitro evaluation j prosthet dent 2004;92:250-7. 39wilson pr, goodkind rj, delong r, sakaguchi r. deformation of crowns during cementation. j prosthet dent 1990;64:601-9. 40campagni wv, preston jd, reisbick mh. measurement of paint-on die spacers used for casting relief. j prosthet dent 1982;47:606-11. 41campbell sd. comparison of conventional paint-on die spacers and those used with the all-ceramic restorations. j prosthet dent 1990;63:151-5. leka'a f.doc j bagh college dentistry vol. 25(4), december 2013 effect of the examination oral and maxillofacial surgery and periodontics 72 effect of the examination stress on periodontal health status and salivary il-1β among iraqi dental students athraa a. mahmood, b.d.s. (1) leka'a m. ibrahim, b.d.s., m.sc. (2) abstract background: periodontal diseases (pd) are common chronic inflammatory diseases caused by pathogenic microorganisms colonizing the gingival area and inducing local and systemic elevations of pro-inflammatory cytokines resulting in tissue destruction by a destructive inflammatory process. stress was considered as one of the important risk factors that cause many inflammatory diseases including pd. the purpose of this study wasto determines and compares clinical periodontal parameters (pli, gi and bop), stress level and salivary il-1β level among dental students before, during and after mid-year exam, also to find the correlation among stress, il-1β and clinical periodontal parameters. materials and methods: the sample was consisted of 24 dental students; 12 male and 12 female aged (21-23) years, theywere examined in this follow up study at three main periods; first period at least one month before mid-year exam (period i), second period during mid-year exam (period ii) and third period at least one month after mid-year exam (period iii). dass-21 was used to measure stress level in all periods. saliva samples were collected to determine the salivary il-1β level by elisa. clinical periodontal parameters were recorded at four sites per tooth. results: the means of all clinical periodontal parameters were higher in the period ii than in the periods i and iii with highly significant differencesat (p ≤ 0.01). as well as, the means concentrations of salivary il-1β were higher in the period ii than in the periods i and iii with highly significant differencesat (p ≤ 0.01). also, by using pearson's correlation coefficient, stress shows highly significant strong correlation with il-1β and clinical periodontal parametersat (p ≤ 0.01). conclusions: the results of this study provided strong evidence of association between examination stress and pd, where dental students during mid-year exam have higher levels of stress, clinical periodontal parameters and salivary il-1β as compared with before and after mid-year exam periods. key words: examination stress, il-1β, saliva, dass-21, periodontal health. (j bagh coll dentistry 2013; 25(4):72-78). الخالصة موضعیة وعامة في المدورات الخلویة المؤدیة ارتفاعاتمزمنة تسببھا كائنات حیة دقیقھ ممرضھ تستعمر منطقھ اللثةوتحفز على التھابیھحول األسنان ھي أمراض أمراض ما:الخلفیة بما في ذلك أمراض االلتھابیةة التي تسبب العدید من األمراض اإلجھاد یعتبر كواحد من العوامل المھمة الخطر. المدمر االلتھابلاللتھابات مما یؤدي إلى تدمیر األنسجة بواسطة عملیة بیتا اللعابي بین طالب طب األسنان قبل، خالل وبعد 1مستوى األجھاد ومستوى البین ابیضاضي األسنان،لتحدید ومقارنة مؤشرات ما حول الغرض من ھذه الدراسة . األسنانما حول . بیتا اللعابي والمؤشرات السریریة لما حول األسنان 1ك، إلیجاد العالقة بین اإلجھاد، البین ابیضاضيوباإلضافة إلى ذل. نصف السنة امتحانفترة في ثالث فترات المتتابعةعاما، الذین تم فحصھم في ھذه الدراسة ) 2321(أنثى تتراوح أعمارھم بین 12ذكرا و 12; طالبا لطب األسنان 24العینة تكونت من :المواد والطرق امتحانالثالثة بشھر واحد على األقل بعد ، الفترة)iiالفترة (نصف السنة امتحانالثانیة خالل ، الفترةi)الفترة (نصف السنة امتحانالفترة األولى بشھر واحد على األقل قبل :سیةرئی . elisaبیتا اللعابي بواسطة 1اللعاب لتحدید مستوى البین ابیضاضي تم جمع عینات من.لقیاس مستوى اإلجھاد في كل المجموعات dass-21استخدم). iiiالفترة (نصف السنة p)مع وجود اختالفات معنویة عالیة عند المتوسطات الحسابیة لجمیع مؤشرات ما حول األسنان السریریة كانت أعلى في الفترة الثانیة مما كانت علیھ في الفترات األولى والثالثة :النتائج بیتا اللعابي كانت أعلى في الفترة الثانیة مما كانت علیھ في الفترات األولى والثالثة مع وجود اختالفات معنویة عالیة عند 1الحسابي لتركیز البین ابیضاضيوكذلك، االوساط .(0.01 ≥ (p ≤ 0.01). عندوالمؤشرات لما حول األسنان ) عابيبیتا الل 1البین ابیضاضي(كذلك، باستخدام معامل ارتباط بیرسون، یثھر اإلجھاد وجود عالقة معنویة قویة مع. (p ≤ 0.01) صف السنة امتلكوا مستویات قدمت نتائج ھذه الدراسة دلیال قویا على االرتباط بین إجھاد االمتحان وأمراض ما حول األسنان، حیث أن طالب طب األسنان خالل امتحان ن:االستنتاج .بیتا اللعابي بالمقارنة مع فترات قبل وبعد امتحان نصف السنة 1ضيابیضاالبین أعلى لإلجھاد ومؤشرات ما حول األسنان و .ما حول االسنان، وصحة dass-21، اللعاب، il-1β، اجھاد االمتحان:الكلمات الرئیسیة introduction periodontal diseases are multifactorial infection characterized by destructive inflammatory process affecting tooth-supporting tissues caused by pathogenic microorganisms, which induce elevations of pro-inflammatory cytokines resulting in tissue destruction. evolution of pd is influenced by many local or systemic risk factors (1). dental plaque, which harbours specific periodontal pathogens, is a primary etiologic factor. where host tissue damage in pd is mainly due to the action of oral microbes and associated host immuneinflammatory responses (2). in addition, several risks and susceptibilities have been associated with pd, like systemic diseases, smoking and psychological stress. several clinical studies have investigated the possible relationship between psychological stress and pd and have suggested that stress may play a role in development of pd (3,4). stress is defined as the reactions of the body to forces of a deleterious nature, infections and various abnormal states that tend to disturb its normal physiological equilibrium (5). it's nevertheless a confirmed and important factor in the etiology and maintenance of many inflammatory diseases, including pd (6). it's said to influence the host defenses, exerting an immunosuppressive effect, increasing one's vulnerability to disease. cytokines and other humoral mediators of inflammation are potent activators of the central stress response, and the glucocorticoids released via this mechanism might regulate the recruitment of immune cells (1) master student, department of periodontics, college of dentistry, university of baghdad. (2) professor, department of periodontics, college of dentistry, university of baghdad. j bagh college dentistry vol. 25(4), december 2013 effect of the examination oral and maxillofacial surgery and periodontics 73 into inflamed tissues, in order to cope with the psychological stress and depression (7). when the inflammatory action is sufficiently long and profound, the systemic manifestations of the disease may become evident, as could happen with pd.many physiopathological processes are involved in periodontal destruction in terms of the inflammatory and immune host response, especially proinflammatory cytokines (8,9). il-1β is a highly pro-inflammatory cytokine strongly associated with periodontal breakdown (10). also, il-1, produced following exposure to immunological and psychological challenges, plays an important role in the neuroendocrine and neurobehavioral stress responses (11).saliva is a mirror to the general health condition that reflects various systemic changes in the body (12).where the composition of saliva immediately reflects the sympathetic and parasympathetic nervous systems, hypothalamic-pituitary-adrenal (hpa) axis and immune system response to stress (13). in addition, salivary levels of various biochemical parameters have been measured in infectious diseases and psychiatric disorders (14). materials and methods the original sample was consisted of 54 dental students, 23 male and 31 female aged (21-23) years were randomly recruited in this follow up study. they were fifth class students from the collage dentistry in university of baghdad and al-mustansiriyah; 11 males and 19 females were excluded from this study in the second and third periods because they were not fit for the criteria of study. therefore, the final sample was 24 students; 12 males and 12 females continue to follow in this study at three main periods. the students enrolled voluntarily in the study after a well explanation of purpose of the investigation and consented to its protocol in period from november 2012 to march 2013. all students in this study were systemically healthy, cooperative, nonsmoker and not taking any antibiotics during the last three months (15).any pregnant and in menstrual cycle women, student had history of chronic systemic diseases with known associations with pd (e.g. diabetes mellitus), student taking psychotropic medication (e.g. prednisone) and any student with retentive factor of dental plaque (e.g. orthodontic appliance) were excluded from this study.clinical periodontal parameters were measured and stress questionnaire were recorded at three main periods: 1. period i (at least 1 month before mid-year exam): students were in the normal range of stress scale of dass criteria and all students given motivation and instructions about brushing technique and the use of dental aids to reduce accumulation of dental plaque and gingival inflammation.itused as a base line. 2. period ii (during mid-year exam): students subjected to stress, again all students given motivation and instructions about brushing technique and the use of dental aids. 3. period iii (at least 1 month after mid-year exam): students were in the normal range of stress scaleof dass criteria. dass-21 was used to measure stress level in all periods. students were answered about stress questionnaires during the three periods before the examination of clinical periodontal parameters; respondents were asked to use 4-points of severity scales to rate the extent to which they have experienced each state over the past week. scores of stress calculated by summing the scores for the relevant items. then, the sum for stress scores evaluated by the severity-rating index (16). saliva sample collection and preparation the students were instructed not eat or drink (except water) for at least 60 minutes before collection of the samples,acidic or high sugar foods can compromise assay performance by lowering saliva ph and influencing bacterial growth. to minimize the effect of these factors, the student was rinsed his/her mouth thoroughly with water then waited 2 minutes for water clearance then subject was sat in a relax position then the whole unstimulated mixed saliva was collected into the polyethylene tubeuntil 2ml was collected. saliva was collected between 8-12 a.m.after sample collection, it was put in a cooling box within 30 minutes and freezing at (70ºc) within 4 hours of collection until assayed, in order to prevent bacterial growth and minimize loss of il-1β in the sample.freezing saliva samples were precipitate mucins. on day of assay, thaw completely then centrifuge at 3000 rpm for 15 minutes. for determination of il-1β in saliva, commercially available elisa was used and performed as recommended in leaflet with kit (salimatrics company, usa). results the mean of pli was elevated in period ii in comparison with other periods, table (1).for comparisons among periods, anova test was used; the results showed that there were hs difference at p-value ≤ 0.01 among and within periods, table (2). lsd was performed for multiple comparisons between each two periods; the results showed that there were hs differences at p-value ≤ 0.01, table (3). also; the mean of gi j bagh college dentistry vol. 25(4), december 2013 effect of the examination oral and maxillofacial surgery and periodontics 74 was elevated in the period ii in comparison with other periods (4).anova test was showed that there were hs difference at p-value ≤ 0.01 among and within periods, table (5). lsd test was showed that there were hs differences at p-value ≤ 0.01 between periods i and ii; ii and iii, while there was ns difference at p-value ≥ 0.05 between periods i and iii as shown in table (6).the number and percentage of bleeding sites in the period ii was higher than the periods i and iii. for comparison among periods, chi-square test was showed that there was hs difference at p-value ≤ 0.01 among periods as shown in table (7). all students in the period ii were within mild to severe range of stress, while in the period i and iii were within normal range of stress. chi-square test was showed that there was hs difference at p-value ≤ 0.01 among periods as shown in table (8).the mean of il1β was elevated in the period ii in comparison with the periods i and iii as shown in table (9).anova test was showed that there was hs difference at p-value ≤ 0.01 among and within periods, table (10). lsd was showed that there were hs differences at p-value ≤ 0.01, table (11). pearson's correlation coefficient (r) of salivary il-1β with clinical periodontal parameters (pli, gi and bop) and stress were strong correlations and hs differences at p-value ≤ 0.01 in all parameters, except bop score (0) the correlation was inverse (negative) correlation and ns difference at p-value ≥ 0.05 as shown in table(12) and pearson's correlation coefficient of stress with salivary il-1β and clinical periodontal parameters were strong correlations and hs differences at p-value ≤0.01 in all parameters, except bop score (0) the correlation was inverse and ns difference at p-value ≥ 0.05 as shown in table (13). discussion the results of this study involving dental students because recent studies have reported high levels of stress among dental and medical students (15,17,18), aged 21-23 years of the fifth class, we selected this class because final class represent more stress class.over the past decade, it has become more apparent that stress can negatively influence oral health status, which can lead to increased amounts of dental plaque, gingival inflammation and more severe periodontitis(19, 20). in the present study, the mean value of pli and gi of period ii was significantly higher than that of periods i and iii, students were found to have more plaque accumulation and gingival inflammation during an exam period, suggesting that examination stress might influence periodontal health status. this result is in conformity with many previous studies (15, 21, 22, 24), who found increased dental plaque and gingival inflammation in students who experienced examination stress. the increased levels of dental plaque and gingival inflammation in the present study may be explained either by influence of increase plaque accumulation during the exam period leading to gingival inflammation, as the plaque is the causative factor of gingival inflammation (behavioral model), behavioral changes in the stressed students, for example, inattention leads to oral hygiene mechanism might be less effective and ⁄ or reduced in frequency during this time of stress, this changes occurring in behavioral have been considered as a reason for association between stress and gingivitis, orby the direct influence of stress on immune system (biologic model), both resulting in increased susceptibility to pd (25).after the exam period, a reduced amount of dental plaque was found and this may partly be explained by the hawthorne effect (23), meaning that panelists involved in clinical trials might be affected because of attention and interest.the percentage of sites with bop was significantly higher in period ii than periods i and iii. the potential altered abilities of period ii to perform effective oral hygiene could result in an increased bop that exacerbates the risk for enhanced tissue destruction in pd. moreover, interesting observations regarding the complexity of the oral and systemic challenge provide unique mechanisms by which deregulation of host responses could occur due to immunologic and behavioral changes, related to examination stress may be lead to pd. where examination stress appears to affect periodontal health status, shown by more plaque accumulation, gingival inflammation and increased amounts of proinflammatory cytokine salivary il-1β therefore examination stress appears as a possible risk factor for gingivitis. this result is in agreement with many previous studies (15,21,24).the students registered their perceived stress on dass-21. the dass is a simple-to-administer, reliable and a valid measurement tool for evaluating stress (17). the dass summarized magnitude of psychological derangement by summing the scores obtained from stress domain only from this scale. where students were asked how stressed they felt on a 4points scale for all periods to compare between them. according to the results of this study, the percentage of stress was significantly higher in period ii than period i and iii. where the dass scores were significantly higher during the exam period compared with other periods. this result is j bagh college dentistry vol. 25(4), december 2013 effect of the examination oral and maxillofacial surgery and periodontics 75 agrees with johannsen et al. (15) which used a visual analogue scale to register the perceived stress of students during an exam period compared with after the exams, michael et al.(26), which used dass to psychological distress in diurnal variations, singh et al.(27), which used dass in measuring stress and its effect on cortisol level in medical student and premkumar et al.(28), which used dass in measuring changes in mood. the proper explanation for this result was dental students who participated in an exam had significantly more stress compared with students who didn't participate in any exam.salivary il-1β was used in this study instead of serum il-1β because saliva has been used as a diagnostic biofluid to measure host responses to a variety of triggering factors in systemic and oral diseases (29). saliva analyses have advantages of quick and easy sample collection not requiring specialized equipment or personnel. moreover, its sampling is painless and noninvasive, therefore, saliva sampling doesn’t cause stress to students. it's one of the most promising mediums for its diagnostic potential for various diseases including stress-related diseases, and it's readily available any time and for repeated samplings (30).also, il-1β levels are generally higher in saliva than in plasma or serum, and serum/plasma levels are often below the limit of detection (31, 32).il-1 is important proinflammatory cytokine in the pathogenesis of pd (10). it induces widespread gene expression of cyclooxygenase-2, inducible nitric oxide synthesis and mmp, which results in activation of osteoclasts, bone resorption and down regulation of type i collagen expression in bone (33). although both isoforms of il-1 (1l-1α and il1β) have similar biological activities and appear to be contributory, but il-lβ is more potent in stimulating bone resorption and is the form more frequently occurring in periodontitis (34). in addition il-1β is a critical mediator of adaptive stress responses as well as stress-associated neuropathology and psychopathology (11). for all these reasons, salivary il-1β was used in this study and the current study is the first of its kind in iraq, that reflect the association between stress, salivary il-1β and periodontal health status;the mean value of il-1β of period ii was significantly higher than that of the period i and iii. where il1β stimulates the hpa axis activity and associated with immune system and inflammation response during stress (11). this result is agrees with many previous studies (24, 35), who found higher amounts of il-1β in gcf during academic examination stress and brydon et al.(36), who found higher amounts of il-1β in human mononuclear cells during psychological stress and disagrees with marques-deak et al.(37), who reported similarities of il-1β level in both stressed and non-stressed individuals and johannsen et al. (16), who reported non-significant difference of il-1β level between during and after exam. one problem in stress studies in general could be the difficulty to know when the influence on the biomarkers by a stress period is over. an explanation to why marques-deak et al.(38) and johannsen et al.(15) didn't find high il-1β levels in gcf, despite a high degree of inflammation could be that hormonal stress inhibits il-1β response to stress (feedback regulation of il-1β) (38, 39).also, some studies have shown that level of pro-inflammatory cytokine, il-1β, are increased in patients with depression (20, 40); however, contradictory results have also been described (41).il-1β level is a sensitive and reliable marker of chronic inflammatory disease activity and il1β elevation may demonstrate tissue destruction (42). thus, in this study the detection of elevated levels of il-1β in saliva of subjects with stress was consistent with the cytokine's role in inflammation and suggests that salivary ll-1β may be a good marker of periodontal inflammation.there was a strong positive correlations between stress, il-1β and clinical periodontal parameters.these results were in agreement with maes et al. and waschul et al. (43, 44), where stress alters immune function, hence increase production ofpro-inflammatory cytokine (humoral immunity) and decrease cellular immunity that lead to periodontal inflammation.in addition, stress was related to pd because psychological stress can directly affect periodontal health status by various biological (physiological) mechanisms; also, it can have indirect effects through the behavioral (psychological) changes in lifestyle such as ignoring oral-hygiene measures that lead to increased levels of dental plaque and consuming more sugar in diet (45). pd develops during stressful condition by tissue destroying factors as il-1β activated by the direct effects of pathogenic bacteria in dental plaque. in addition, many physiopathological processes are involved in periodontal destruction in terms of the inflammatory and immune host response, especially proinflammatory cytokines or mmps (8, 9). all these factors lead to strong correlation among il-1β, plaque, gingival inflammation, bop and stress. this result is in agreement with many previous studies (24, 35). as a conclusion, the examination stress was affected on periodontal health status by more plaque accumulation, gingival inflammation and j bagh college dentistry vol. 25(4), december 2013 effect of the examination oral and maxillofacial surgery and periodontics 76 increased amounts of il-1β in saliva, so there was strong correlations between themand examination stress was appeared as a possible risk factor for gingivitis. references 1. malathi k, sabale d. stress and periodontitis: a review. dms 2013; 9(4): 54-7. 2. van dyke te. cellular and molecular susceptibility determinants for periodontitis. periodontol 2000 2007; 45(1):10-3. 3. elter jr, beck jd, slade gd, offenbacher s. etiologic models for incident periodontal attachment loss in older adults. j clin periodontol 1999; 26(2):113-23. 4. akcali a, huck o, tenenbaum h, davideau jl, buduneli n. periodontal diseases and stress: a brief review. j oral rehabil 2013; 40(1): 60-8. 5. lathrop, thomas. stedman's medical dictionary. 28th ed. philadelphia: hubsta ltd; 2008. 6. keshava pk, sangeeta nu.stressing the stress in periodontal disease. j pharm biomed sci 2013; 26(26): 345-8. 7. breivik t, thrane ps. psychoneuroimmune interaction in periodontal disease. in: psychoneuroimmunology. in: ader r, fetten dl, cohen n. 3rd ed. san diego: academic press; 2001; 627-44. 8. kiecolt-glaser jk, preacher kj, maccallum rc, atkinson c, malarkey wb, glaser r. chronic stress and age-related increases in the proinflammatory cytokine il-6. proc natl acad sci usa. 2003; 100(15): 9090-5. 9. van dyke te, kornman ks. inflammation and factors that may regulate inflammatory response. review. j clin periodontol 2008; 79(8):1503-7. 10. dayan s, stashenko p, niederman r, kupander t. oral epithelial overexpression of il-1 alpha causes periodontal disease. j dent res 2004; 83(10): 786-90. 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(ivsl). 45. leresche l, dworkin sf. the role of stress in inflammatory diseases, including periodontal disease: review of concepts and current findings. periodontol 2000 2002; 30(1): 91-103. j bagh college dentistry vol. 25(4), december 2013 effect of the examination oral and maxillofacial surgery and periodontics 78 19suhail f.doc j bagh college dentistry vol. 28(3), september 2016 the efficacy of oral and maxillofacial surgery and periodontics 116 the efficacy of polidocanol foam sclerotherapy in treatment of infantile hemangioma and slow-flow vascular malformation suhail ibraheem kadhum, b.d.s. (1) thair abdul lateef, b.d.s., h.d.d., f.i.b.m.s. (2) abstract background: sclerotherapy is a simple treatment modality for treatment of infantile hemangioma and slow-flow vascular malformations; polidocanol is a mild sclerosing agent that is traditionally used in treatment of varicose veins. this study aims to evaluate the effectiveness, treatment outcome, and complications of polidocanol foam sclerotherapy for infantile hemangioma and slow-flow vascular malformations. materials and methods: between march 2013 and december 2014, seventeen patients with infantile hemangioma and slow-flow vascular malformations treated with polidocanol 1% foam sclerotherapy. foam was prepared by tessari’s method. injection performed under general or local anesthesia, injections were repeated (if necessary) on monthly basis, assessment of lesion size and response to treatment was performed by ultrasonography. effectiveness of polidocanol foam sclerotherapy was evaluated according to reduction in lesion size. results: a total of 17 patients were enrolled, 15 of them (88.23%) were females and 2 (11.76%) were males, with age range from 10 months to 57 years old (mean age 21.69). eleven patents (64.7%) had venous malformations while 6 patients (35.29%) had infantile hemangioma. mean number of treatment sessions was 2.76. nine patients had excellent outcome, 3 with good outcome, 3 with fair outcome and 2 had poor outcome in relation to lesion size. complications were transient. conclusions: polidocanol foam sclerotherapy is an easy to perform procedure, safe, and repeatable, provide excellent outcome for venous malformations and good outcome for infantile hemangioma. keywords: sclerotherapy, polidocanol, infantile hemangioma, vascular malformations. (j bagh coll dentistry 2016; 28(3):116-120). introduction vascular anomalies are congenital errors of vascular development causing identifiable birthmarks of the skin and mucosa and a variable degree of underlying soft tissue abnormalities (1,2). vascular lesions most often first present in pediatric patients and are among the most common congenital and neonatal abnormalities with a reported incidence of 10—12% in caucasian infants and approximately 60% of them occurring in the head and neck region (3). vascular anomalies are now divided into two main categories: vascular tumors and vascular malformations. infantile hemangiomas comprise the majority of vascular anomalies and are considered the predominant vascular tumor type composed of rapidly proliferating endothelial cells (1). unlike hemangiomas, vascular malformations are uncommon, rarely regress, and continue to expand, and have high rates of recurrence following (4-6). infantile hemangiomas proliferate during the first 9–12 months of life and subsequently involute at a variable course over many years (7,8). vascular malformations are composed of ectatic venous channels that will continue to grow throughout the patient’s lifetime. the overall incidence of venous malformation is about 1 in 10 000 (9). (1)student in iraqi board of maxillofacial surgery. (2)assist. professor. department of oral and maxillofacial surgery. college of dentistry, university of baghdad. mulliken and glowacki suggested that the term vascular malformation be used to describe anomalies of vasculature that are present at birth, grow proportionally with the child, have normal endothelial turnover, and do not spontaneously regress (10). sclerotherapy sclerotherapy was described as a treatment of varicosities as early as the 1830s.andrew and kelly were the first to describe its role in infantile hemangioma. the aim of sclerotherapy is the fibrous occlusion of the vessel lumen rather than merely thrombosing a vessel that may be amenable to recanalization, sclerosing a vessel transforms it into a fibrous cord, which cannot be recanalized (11). contra-indications for sclerotherapy there are relative and absolute contra indications for sclerotherapy (margaret w. mann, 2011), relative contra-indications include: • marked allergic diathesis/severe bronchial asthma • poor general health/severe concomitant disease (malignancy and cardiovascular and respiratory tract diseases) • immobility • known thrombophilia or hypercoagulable state • needle phobia j bagh college dentistry vol. 28(3), september 2016 the efficacy of oral and maxillofacial surgery and periodontics 117 • known asymptomatic patent foramen ovale (pfo) (especially with foam sclerotherapy) • arteriovenous malformation (more difficult to treat and higher risk of necrosis). while absolute contra-indication are • known allergy to the sclerosant • history of extensive deep venous thrombosis dvt • acute superficial or deep vein thrombosis • local infection in the area of sclerotherapy, cellulitis, or severe systemic infection • pregnancy (polidocanol crosses the placental barrier) • advanced peripheral arterial occlusive disease • advanced collagen vascular disease. foam sclerotherapy foam sclerotherapy is more efficacious in seclerosing larger-diameter vessels because the bubbles mechanically displace blood, thereby 1maximizing the contact time 2maximizing surface area between the sclerosant and the vein endothelium. 3lower concentration and volume are needed to effectively sclerose veins using foam in comparison to liquid sclerotherapy (12). polidocanol polidocanol (aethoxysclerol, kreussler, wiesbaden, germany) is a widely used nonionic detergent sclerosant that was first developed as an anesthetic and acts through endothelial over hydration, vascular injury, and closure (13). polidocanol is a more moderate form of ethanol. it is an effective sclerosing agent that consists of 95% hydroxypolyethoxydodecane and 5% ethyl alcohol and is known to have a low risk of complications. the maximum recommended dose varies in the literature (the range varies from 10 to 20 ml of 3% solution) but to the european guidelines it is of 2 mg/kg (10 ml 1% solution for a 50-kg individual). at near maximum dosage, patients have reported perioral paresthesia or strange taste sensation, which may be related to the anesthetic property of polidocanol. toxic levels can produce cardiotoxicity, much like lidocaine toxicity, resulting in bradycardia and hypotension (12). materials and methods this study involved 17 consecutive patients (15 females, 2 males), who are sustained with vascular lesions in the head and neck region, those patients have attended the consultation clinic of maxillofacial surgery department in ghazi al hariri specialized surgical center, baghdad, from march 2013 to december 2014, and was included and followed for 6 months. patients included in this study were 1patients with infantile or congenital hemangioma 2patients with slow flow vascular malformation (capillary, venous, or lymphatic) 3patients with vascular lesions who had poor treatment results by other types of sclerosing agents while patient excluded are those with: 1known sensitivity to polidocanol 2patients with poor general health or medically compromised, like diabetes mellitus, hypertension, history of dvt, malignancy, ischemic heart diseases, pregnancy, etc. 3arteriovenous vascular malformations 4cellulitis with local infection in area intended for sclerosant injection doppler ultrasonography was used for the purpose of assessment of size, site, extension, and flow pattern, the device used in this study was phillips hd11xe, manufactured by philips electronics 2008, netherlands. polidocanol (aethoxysclerol) was used as a seclerosing agent, it is supplied as 2 ml ampules, a package of 5 ampules, the required amount was from 0.5 ml to 5 ml sclerotherapy tray a sclerotherapy tray is set up and it included: cotton swabs, iodine povidine solution, dental syringe with xylocain local anesthesia, 2 syringes 5ml each, 1 syringe 1ml, 3 way stop cock, 1% polidocanol ampules, gauze, and adhesive tapes. sclerotherapy is shown in (fig 1). the procedure is generally performed in the out-patient clinic setting unless there is a need for general anesthesia, the patient is comfortably seated. intended site for injection is scrapped with cotton swabs and povidone-iodine solution in circular movement starting from accused site outward. in case requiring general anesthesia, the scrapping is done after the patient is anesthetized, but when with local anesthesia scrapping is done first. administration of local anesthesia by infiltration technique around the lesion, the amount injected was one ampule (i.e. 2.2 ml), waiting till patients is well anaesthetized, and then preparation of foam is carried out. in this study, liquid sclerosant is turned into foam by tessari’s method or so called “double syringe technique” in which room air is mixed with the liquid via a 3-way stop cock and agitated j bagh college dentistry vol. 28(3), september 2016 the efficacy of oral and maxillofacial surgery and periodontics 118 back and forth for about 10 times. the foam produced is stable to about a minute then it turns into a liquid again. foam production is shown in fig 1 the mixing ratio is 3:1 room air to sclerosant, amount of foam injected equals to the volume of the lesion, and this means that the patient will receive ¼ liquidconcentrations by volume. fig 1: syringes containing foam connected via 3-way stop cock, the first syringe contains 1 ml of liquid polidocanol and the other contains 3 ml or room air. the needle introduced into the lesion from adjacent normal tissue directed toward the most vascular part (if visible) until blood can be aspirated, the injection is performed slowly with light pressure from the more vascular area then distributed to the periphery, during this time foam is seen to displace blood from the lesion and a form of temporary blanching prevails, injection is continued until the measured amount was administered, then drawn out. gauze dressing applied for about 10 minutes. evaluation of treatment effectiveness included 4 scales: scale 1: poor (0 to 25 percent) scale 2: fair (26 to 50 percent) scale 3: good (51 to 75 percent) scale 4: excellent (76 to 100 percent) results patients enrolled in the study were 17 patients, 15 of them were females (88.23%) and 2 males (11.76 %) as shown in table 1. table 1: gender distribution statistics genders no. of patients percentage males 2 11.76 females 15 88.23 total 17 100 patients diagnosed as having infantile hemangioma were six patients (35.2%), 5 of which were females and 1 male, while patients who had venous malformations were 11 (64.7%), 10 of them were females and 1 male. relations are shown in table 2. table 2: relation the lesion type and gender female male total percentage venous malformation 10 1 11 64.7% infantile hemangioma 5 1 6 35.29% twelve patients underwent sclerotherapy sessions under local anesthesia with vasoconstrictor and five under general anesthesia. nine patients (75%) of the patients treated under local anesthesia had excellent results and the rest had good and fair results, while patients treated under general anesthesia had response range of poor to fair. treatment sessions two patients received single injection session, 6 patients received 2 injections, 5 patients received 3 injections, and 3 patients received 4 injections while 1patient had received 6 injection sessions ,injections were performed on monthly basis resulting in a mean value of 2.76. twelve patients underwent sclerotherapy sessions under local anesthesia with vasoconstrictor and five under general anesthesia. nine patients (75%) of the patients treated under local anesthesia had excellent result and the rest had good and fair results, while patients treated with general anesthesia had response range from poor to fair. treatment outcome nine patients has excellent outcome (decrease of size of lesion range from 76-100%), 3 patients had good outcome (reduction in size range from 51-75%), 3 patients had fair outcome (decrease in lesion size range from (26-50%), while 2 patients had poor outcome (reduction in size was less than 25%), results are shown in fig. 2. the response varied between infantile hemangioma and venous malformation as shown in table 3. table 3: relation between lesion type and response lesion type response 76 100% excellent 5175% good 2650% fair 025% poor infantile hemangioma 0 2 3 1 venous malformations 9 1 0 1 j bagh college dentistry vol. 28(3), september 2016 the efficacy of oral and maxillofacial surgery and periodontics 119 relation of patient’s age to the amount of reduction in lesion size is shown in fig. 3. 48.5 99.5 89 100 100 70 100 100 100 57 91.6 58 27.7 39.5 4.35 0 20 40 60 80 100 120 0-10 10-20 20-30 30-40 40 swelling and necrosis were the only complications observed throughout this study, they were transients and as shown in table 4. table 4: relation between no. of patients, no. of sessions, and complications type of complication no. of patients percentage no. of sessions percentage swelling 14 82% 33 70% necrosis 1 5.8% 1 2.1% fig. 4: patient with venous malformation treated by polidocanol foam sclerotherapy, a before treatment, b after 3 injection sessions. discussion in this study, the female: male ratio was 9:1 which coincide with haggstrom et al who studied a group of 1058 patients, 750 of them (71%) were females while the other 308 patients (29%) were males (2), but this ratio is far from kryger & sisco 2010 results that stated that female: male ratio was 3:1 (14). this difference in ratio may be related to the fact that this study only included infantile hemangiomas and venous malformations, also related to the small number of patients enrolled. the study also showed that venous malformations occurred 2 times more than infantile hemangioma in females (10 females with ih, and5 with vm) while it is the same in male patients (1 male with ih and 1 male with vm), this might be related to the effect of estrogen in the pathogenesis of vascular lesions which is supported by mulliken and glowacki (10). haggstrom et al found that infantile hemangiomas affect 10% of population with a greater incidence in caucasian, female gender, and premature low-weight birth children (2). a b fig. 2: the number of patients in relation to the amount of decrease in lesion size. fig 3: relation between age and response j bagh college dentistry vol. 28(3), september 2016 the efficacy of oral and maxillofacial surgery and periodontics 120 patients treated under local anesthesia had poor to excellent response (12.85-100%) in comparison to those treated under general anesthesia that had poor to good results (4.35 57%), this might be due to the effect of vasoconstrictor present in the anesthetic agent, which increases the contact time between the sclerosing agent and endothelium thus increasing its effect in relation to dose. this is supported by dietzek interpretation that epinephrine helps with vessel vasoconstriction producing a longer dwell times and helps with sclerosing agent effect (15). infantile hemangioma showed poor to good response (4.3570.22%) to sclerotherapy while venous malformations had poor to excellent response (12.85 -100%). this might be related to the pathogenesis of each lesion, infantile hemangioma as a benign tumor involve vessels that have hyperplastic endothelial cells, the ones that vessels of venous malformations don’t have and instead they have normal but hypertrophied endothelium which leads to reduced effect of sclerosing agent. the response to polidocanol sclerotherapy in children (1st decade of life) ranged from 4.35% to 70% which was relatively less than that of adolescents and adults (12.8 to 100%), and this might be related to healing and regeneration ability which is relatively higher in children, as well asthe ongoing growth phase that counter acts the effect of endothelial fibrosis and damage induced by the sclerosant, thus leading to less response. swelling is evident due to the inflammatory response induced by polidocanol, this agree with e. gorrizgommez et al (16) study on 15 patients and stated that direct puncture 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jabeen m. infantile hemangioma: an update. indian j dermatol leprol 2010; 76: 469-75. 14kryger zb, sisco m. practical plastic surgery, landes bioscience texas u.s.a.: vademecum, austin; 2007. 15dietzek cl. sclerotherapy: introduction to solutions and techniques, perspectives in vascular surgery and endovascular therapy 2007; 19: 317-24. 16górriz-gómez e, vicente-barrero m, loras-caballero ml, bocanegra-pérez s, castellano-navarro jm, pérez-plasencia d, ramos-macías a. sclerotherapy of face and oral cavity low flow vascular malformations: our experience. bri j oral and maxillofac surg 2013; 52: 43–7. 12noor f.doc j bagh college dentistry vol. 28(3), september 2016 histological evaluation oral diagnosis 75 histological evaluation of effect of beta-tricalcium phosphate on bone healing in alloxan-induced diabetes noor abdulkareem razouki, b.d.s., h.d.d. (1) ban a. ghani, b.d.s., m.sc., ph.d. (2) abstract background: improved glucose level control with insulin injections have allowed for the diabetic population to live longer and healthier lives. unfortunately diabetes remains a worldwide epidemic disease with multiple health implications. specifically, its effects upon fracture healing are compromised in diabetics with as high as 87% recovery delay relative to “healthy” counterparts. current medical treatments for bone injuries have been largely focused on replacing the lost bone with allogenic or autogenous bone grafts, beta-tricalcium phosphate (β -tcp), a ceramic alloplast, has interconnected system of micropores, has been widely used as a biologically safe osteoconductive bone substitute. the aim of this study was histological evaluation of effect of topical application of β –tcp on bone healing of diabetic rabbit. materials and methods: sixty new zealand rabbits used in this study were divided into three groups for four healing intervals the experimental groups were: 1-control group(c).2-diabetic rabbits received insulin treatment regarded as controlled diabetes mellitus (cdm)group.3-diabetic rabbits did not receive any treatment regarded as uncontrolled diabetes mellitus (udm)group. all animals subjected to surgical operation in right tibia, creating bone defect 3mm in depth and 4mm in diameter filled with β-tricalcium phosphate. animals' scarifications were done in 5 day, 2, 4 and 6 weeks durations. routine processing and sectioning technique was performed for histological evaluation. results: histological findings indicated that bone defects in control(c) and controlled diabetes mellitus (cdm) groups showed early bone formation, mineralization and maturation in comparison to healing of uncontrolled diabetes mellitus (udm) group. histomorphometric analysis for all bone parameters examined in this study, showed variation in significance among all groups in different durations. conclusion: the study revealed that application of β-tcp was more effective in enhancement of bone regeneration and in acceleration of bone healing process in controlled diabetes as compared to the uncontrolled one. key words: osteoconduction, diabetes mellitus, beta-tricalcium phosphate. (j bagh coll dentistry 2016; 28(3):75-81). introduction research on bioactive material on bone healing is one of the thrust scientific fields to developing of a novel bioactive material, which have wide application in dentistry and biomedical fields (1). bone healing is a dynamic process that is a result of smooth progression from one healing stage to another, the phases of bone healing: hemostasis, angiogenesis, and bone formation are all present in the drill-hole defect model (2). β-tricalcium phosphate (β-tcp) is widely applied material in clinical orthopedic and due to its high osteoconductivity, lack of histotoxicity (3). several mechanisms have been reported to explain the greater delay of healing and non-union of fractures in diabetes. these include reduction in blood supply and angiogenesis (4). severe increased inflammatory response levels of systemic inflammatory markers serum levels of both tumor necrosis factor-a and interleukin-6, a decrease in collagen synthesis, a disturbance in the mineralization process, and an imbalance between bone resorption by osteoclasts and bone deposition by osteoblasts thought affect bone healing in diabetes (5). (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2)assist. professor, department of oral diagnosis, college of dentistry, university of baghdad the aim of this study was histological evaluation of effect of topical application of β – tcp on bone healing of diabetic rabbit. materials and methods the materials used in the present study were beta tricalcium phosphate(septodont/france), alloxan (100 mg, england), anesthetic solution: ketamine hydrochloride 50 mg and xylazine 2%, formalin 10%,ethanol alcohol 96%,xylol, paraffin wax, and hematoxylin and eosin (h&e) stain. sixty new zealand rabbits of weight 1.5 –2kg were used in this study, they were divided into 20 rabbits as control group(c) and 40 rabbits were weighted to calculate the dose of alloxan given to them. the rabbits were injected by a single dose (150 mg/kg b.w.) intravenously. five to seven days after injection; severity of the induced diabetic state was assessed by daily monitoring of blood glucose levels. after elevation of blood glucose level, the rabbits randomly divided into: controlled diabetes mellitus (cdm) group received subcutaneous injection of insulin as a treatment in a dose of 0.1mg/kg b.w. to control the hyperglycemia, with daily monitoring of blood glucose level and uncontrolled diabetic mellitus (udm) group they didn’t receive any treatment(6). j bagh college dentistry vol. 28(3), september 2016 histological evaluation oral diagnosis 76 surgical procedure a hole of about 4 mm in diameter and 3mm in depth was made in the proximal tibia metaphysis of the right limb of all animals by intermittent drilling and irrigation with saline, after that the operation site was washed with a sterile normal saline to remove debris and then the dried hole was filled with β-tricalcium phosphate, suturing of soft tissues was done and prophylactic antibiotic was given to animals. animals were scarified by an overdose of anesthetic solution at (5 days, 2, 4 and 6 weeks) healing intervals. removal of skin, facia and muscles at the operation site was performed; afterwards bone specimens were prepared by cutting the bone about 5 mm away from operation site with continuous irrigation with saline to avoid bone damage. the specimens were fixed in 10% buffered formalin for 48h,decalcified with solution of formic acid and sodium citrate, then bone tissue dehydrated with alcohol and embedded in paraffin. sections of 5μm were prepared in the usual fashion, and stained with hematoxylin and eosin stain. histological evaluation was performed using light microscope to measure the number of bone cells (osteoblasts, osteocytes, and osteoclasts), trabecular area (mm2), bone marrow area (mm2) and trabecular number. measurements were performed by image processing software program (imagej.exe). two microphotographs were taken by a camera attached to the microscope at power x4, one in upper part and other picture in lower part to cover approximately all defect area. results histological evaluation five days duration control group (c): histological findings of defect area in control group after 5 days shows deposition of bone matrix rimmed by osteoblasts (figure1). figure 1: view of defect area in control group after 5days shows immature bone matrix and osteoblasts (ob) (arrow) at periphery. h & e x40. control diabetes mellitus group (cdm): microphotograph of defect site shows osteoblasts and osteocytes (figure 2). figure 2: view of cdm group at 5days shows osteoblasts (ob), and osteocytes (oc). h & e x40. uncontrolled diabetes mellitus group (udm): histological view of defect site at 5 days healing period, shows recruitment of inflammatory cells around blood islets (figure 3). figure 3: view of 5days duration in udm group shows blood islets surrounded by inflammatory cells (arrows). h&e x40. two weeks duration control group(c): view of 2weeks at defect site show osteoblasts rimming bone trabeculae, and osteocytes within it (figure 4). figure 4: view in control group of 2weeks duration shows, bone trabeculae osteoblasts (ob) and osteocytes (oc). h& e x40. controlled diabetes mellitus group (cdm): histological view shows bone trabeculae numerous osteocytes trapped inside matrix and reversal line (figure 5). j bagh college dentistry vol. 28(3), september 2016 histological evaluation oral diagnosis 77 figure 5: view of 2weeks duration in cdm group shows reversal line (arrow). h&e x20. uncontrolled diabetes mellitus group (udm): histological view shows defect area filled with β-tcp material surrounded by numerous bone trabeculae, osteoblasts seen at their periphery, and osteocytes in bone matrix (figure 6). figure 6: view of defect site in udm group after 2 weeks shows osteoblasts (ob), rimming newly formed trabeculae. h & e x20. four weeks duration: control group (c): view of defect area in control group shows bone trabeculae, new and old bone are separated by reversal line, osteoblasts and numerous irregularly arranged osteocytes, and osteoclasts indicate bone remodeling (figure 7) . figure 7: view of 4weeks shows bone trabeculae, osteoblast, osteocyte and osteoclast, (ocl) and reversal line (arrow). h&e x40. controlled diabetes mellitus group (cdm): histological view illustrates bone trabeculae at defect area, osteocytes trapped in the bone matrix, reversal line between new and old bone (figure 8). figure 8: view of 4weeks duration in cdm group shows numerous irregular osteocytes (oc) trapped in bone trabeculae (bt), and reversal line (arrow). h &e x20. uncontrolled diabetes mellitus group (udm): histological view shows β-tcp material is surrounded by newly formed bone, osteoblast at the periphery, numerous scattered osteocytes in the bone matrix (figure 9). figure 9: view of defect site after 4weeks in udm group shows β-tcp material, surrounded by new bone trabeculae (arrows). h & e x20. six weeks duration control group(c): the histological view in control group at 6 weeks duration at defect site shows bone trabeculae, osteocytes and osteoblasts (figure 10). figure 10: view of control group after 6 weeks shows bone trabeculae enclosing j bagh college dentistry vol. 28(3), september 2016 histological evaluation oral diagnosis 78 haversian canals (hc) lined by osteoblasts, surrounded by osteocytes (oc) h&e x20. controlled diabetes mellitus group (cdm): after 6 weeks view of defect site shows mature dense bone trabeculae and osteocytes appear regularly arranged around haversian canals which are lined by osteoblasts (figure11). figure 11: microphotograph view at defect site of 6weeks duration in cdm group shows haversian canals lined by osteoblasts (ob) and surrounded by osteocytes (oc). h & ex 20. uncontrolled diabetes mellitus group (udm): histological view shows defect site filled with trabeculae, with numerous scattered osteocytes inside bone matrix, osteoblasts seen at areas occupied by β-tcp material (figure12) figure 12: view in udm group after 6weeks shows bone trabeculae (bt), with scattered osteocytes (oc), osteoblasts) and areas of remnants of β-tcp material. h & ex 40. inflammatory cells parameter the results of the present study showed that mean values of inflammatory cell count were decreasing with time in each studied group (c, cdm, udm),and the highest mean values recorded were in udm group at 5days healing period (figure 13). figure 13: comparison of mean values of inflammatory cells among studied groups in different durations. histomorphometrical analysis of bone architecture parameters all measured parameters had increased mean value with time except bone marrow area was decreased in all groups, the highest mean value of all measured parameters were recorded in(c) group except bone marrow area and osteoclast in (udm)group. the mean values of bone marrow area, trabecular area, osteoblasts and osteocytes showed high significant difference in all groups with different duration except bone marrow area showed significant difference at 6weeks, while trabecular no. mean value showed non significant difference at 2 and 4weeks but at 6weeks duration showed significant difference only (table 1). table 1: descriptive statistics and group differences in each duration of bone parameters duration variables groups descriptive statistics group difference (d.f.=14) n mean s.d. s.e. min. max. f-test p-value 2 weeks trabecular no. control 5 6.20 1.92 0.86 4 9 2.396 0.133 (ns) cdm 5 5.20 1.92 0.86 3 8 udm 5 3.80 1.30 0.58 2 5 trabecular area control 5 0.96 0.17 0.08 0.759 1.22 23.137 0.000 (hs) cdm 5 0.75 0.05 0.02 0.697 0.793 udm 5 0.52 0.02 0.01 0.497 0.553 bone marrow area control 5 1.16 0.11 0.05 1.01 1.3 29.446 0.000 (hs) cdm 5 1.32 0.07 0.03 1.251 1.412 udm 5 2.01 0.30 0.13 1.674 2.391 osteoblasts control 5 6.00 1.54 0.69 4.5 8.5 11.499 0.002 (hs) cdm 5 5.45 1.18 0.53 3.5 6.5 udm 5 2.10 1.43 0.64 0.5 4 osteoclasts control 5 0.50 0.35 0.16 0 1 3.263 0.074 (ns) cdm 5 0.60 0.22 0.10 0.5 1 j bagh college dentistry vol. 28(3), september 2016 histological evaluation oral diagnosis 79 udm 5 1.10 0.55 0.24 0.5 2 osteocytes control 5 9.25 1.44 0.64 7.25 11 12.584 0.001 (hs) cdm 5 7.75 2.32 1.04 5.5 11.5 udm 5 4.10 0.96 0.43 3 5.5 4 weeks trabecular no. control 5 7.80 1.48 0.66 6 10 0.902 0.431 (ns) cdm 5 7.20 1.30 0.58 6 9 udm 5 6.40 2.07 0.93 4 9 trabecular area control 5 1.82 0.10 0.05 1.689 1.915 57.723 0.000 (hs) cdm 5 1.46 0.06 0.03 1.386 1.534 udm 5 1.07 0.15 0.07 0.867 1.233 bone marrow area control 5 0.73 0.08 0.03 0.626 0.81 23.865 0.000 (hs) cdm 5 0.83 0.04 0.02 0.781 0.887 udm 5 1.07 0.11 0.05 0.939 1.212 osteoblasts control 5 8.50 2.06 0.92 6 11 8.455 0.005 (hs) cdm 5 6.15 1.50 0.67 4.75 8 udm 5 4.00 1.58 0.71 2 6 osteoclasts control 5 0.40 0.55 0.24 0 1 0.563 0.584 (ns) cdm 5 0.40 0.55 0.24 0 1 udm 5 0.70 0.45 0.20 0 1 osteocytes control 5 12.30 1.48 0.66 10 14 20.047 0.000 (hs) cdm 5 11.10 2.46 1.10 9 15 udm 5 5.60 1.14 0.51 4 7 6 weeks trabecular no. control 5 12.20 3.11 1.39 9 16 6.454 0.013 (s) cdm 5 10 2.74 1.22 7 14 udm 5 6.60 1.14 0.51 5 8 trabecular area control 5 2.38 0.19 0.09 2.143 2.65 28.472 0.000 (hs) cdm 5 2.12 0.17 0.08 1.887 2.316 udm 5 1.46 0.23 0.10 1.114 1.66 bone marrow area control 5 0.54 0.07 0.03 0.469 0.636 4.174 0.042 (s) cdm 5 0.66 0.05 0.02 0.591 0.724 udm 5 0.86 0.29 0.13 0.54 1.21 osteoblasts control 5 6.30 0.82 0.37 5.25 7.5 21.573 0.000 (hs) cdm 5 5.15 0.96 0.43 4 6.25 udm 5 2.75 0.83 0.37 2 3.75 osteoclasts control 5 0.30 0.45 0.20 0 1 0.438 0.656 (ns) cdm 5 0.40 0.55 0.24 0 1 udm 5 0.60 0.55 0.24 0 1 osteocytes control 5 16.50 2.50 1.12 13 20 18.166 0.000 (hs) cdm 5 15.85 1.75 0.78 13.5 18 udm 5 7.50 3.39 1.52 4 12 discussion histological evaluation according to the present findings deposition of organic matrix of bone was detected at 5days in (c) and (cdm) groups , as reported by previous studies, (7,8) that could be due to role of β-tcp in accelerating healing more effectively by promoting vascularization and ossification, due to it’s similarity in composition to the mineral component of bone and presence of micropores which have been proven important in the bone induction process. micropores enlarge the surface area, which facilitates ion exchange and bone-like apatite formation, and/or accompanied binding of endogenous bone inducing proteins to the surface, all of which may positively affect the adhesion, proliferation, and differentiation of the bone forming cells thus can precipitate new bone growth onto the cement surface as reported by zhang et al. (9). the findings of the present study indicated accelerate healing process after controlling of hyperglycemia by insulin, where the highest mean values of inflammatory cells that infiltrated into bone defect sites were recorded at 5 days and especially in udm group, it was obviously decreased during the 2, 4 and 6weeks periods in agreement with the findings of cardaropoli et al. (10). highest mean values of inflammatory cells were seen in udm group which could be due to severe inflammatory response levels of systemic inflammatory markers both tumor necrosis factor-a and interleukin-6 as j bagh college dentistry vol. 28(3), september 2016 histological evaluation oral diagnosis 80 reported by suzuki et al. (5). at 4 weeks duration, immature bone trabeculae surrounding β-tcp were seen with signs of bone remodeling, in accordance with the findings reported by ogose et al. who evaluated the histologic characteristics of β-tcp in the human femur and observed a considerable amount of newly formed bone on βtcp particles and found osteoclast-like giant cells surrounding β-tcp particles (11). the remodeling process lasts for 3 to 6 months in humans and 6 weeks in rabbits (12). a marked reduction in mean number of osteoblasts, osteocytes, and trabecular area and increased in bone marrow area was noticed in the present results in the animals of udm group than that of animals of other groups. this result agreed with luu et al. (13), regarding udm, the findings of this study, they could be explained according to: 1botolin et al. who revealed that decreased numbers of osteocytes and osteoblasts, serum alkaline phosphatase and osteocalcin levels suggesting reduced bone formation (14). 2diabetes decreases osteoclastogenesis reduces bone formation and enhances apoptosis of osteoblastic cells in bacteria stimulated bone loss (15,16). they affirmed that diabetes may cause a net loss of bone because the suppression of bone formation is greater than the suppression of bone resorption. 3confirmed by other studies that evaluated fracture healing at 2, 4, and 6 weeks suggesting that diabetes decreases the anabolic aspect of fracture healing by affecting osteoblasts in terms of formation, function, and bone deposition (17). at 4 and 6weeks of healing periods more osteoblasts and osteocytes were detected in (c) and (cdm) groups and marked increased in trabecular area, indicating progression of bone deposition and maturation and being denser with narrowing of marrow tissue regions. when compared with udm group, in agreement with results of an experimental study conducted by soares et al. who revealed that at 4 weeks the specimens showed the defect either partially or completed filled by newly formed interconnecting trabecular bone of varied thicknesses (18). results obtained concerning cdm groups could be explained according to the fact that insulin has been postulated to elicit an anabolic role in bone, it has been suggested that insulin signaling pathways may mediate communication between metabolic control and appropriate bone remodeling as demonstrated by fulzele et al. by means of an in vitro model that insulin administration suppresses an inhibitor of osteoblast development (19). as conclusion; the study revealed that application of β-tcp was more effective in enhancement and in acceleration of healing process of bone defects in healthy animals and in controlled diabetic as compared to the uncontrolled ones. references 1. mauth c, huwig a, graf-hausner u, roulet j. topics in tissue engineering 2007; 3: 1-30. 2. mueller m, schilling t, minne hw, ziegler r. a systemic acceleratory phenomenon (sap) accompanies the regional acceleratory phenomenon (rap) during healing of a bone defect in the rat. j. bone miner res 1991; 6(4): 401-10. 3. kobayashi k, shimoyama k, nakamura k, murata k. percutaneous vertebroplasty immediately relieves pain of osteoporotic vertebral compression fractures and prevents prolonged immobilization of patients. eur radiol 2005; 15: 360-7. 4. dib sa, russo emk, chacra ar. tratado de endocrinologia clínica. são paulo: editora rocca; 1992. 5. suzuki k, kurose t, takizawa m, maruyama m, ushikawa k, kikuyama m, et al. osteoclastic function is accelerated in male patients with type 2 diabetes mellitus: the preventive role of osteoclastogenesis inhibitory factor/osteoprotegerin (ocif/opg) on the decrease of bone mineral density. diabetesres clin pract 2005; 68: 117-25. 6. wang j, wan r, mo y, zhang q, sherwood lc, chien s. creating a long-term diabetic rabbit model. experimental diabetes research 2010; article id 289614, 10 pages 7. ghareeb r. the role of topical application of bone morphogenetic protein 7 (bmp7) as a biomaterial on bone healing. a master thesis. college of dentistry, university of baghdad, 2014. 8. fadhil e. histological and immunohistochemical evaluation of the effect of local exogenous application of vegf on bone healing. a master thesis. college of dentistry, university of baghdad, 2014. 9. zhang w, li g, deng r, deng l, qiu s. new bone formation in a true bone ceramic scaffold loaded with desferrioxamine in the treatment of segmental bone defect: a preliminary study. j orthopaedic sci 2012;17(3): 289–98. 10. cardaropoli g, araujo m, lindhe j. dynamics of bone tissue formation in tooth extraction sites. an experimental study in dogs. j clinical periodontol 2003; 30(9):809-818. 11. ogose a, hotta t, hatano h, kawashima h, tokunaga k, endo n, et al. histological examination of beta-tricalcium phosphate graft in human femur. j biomed mater res 2002; 63(5): 601–4. 12. rokn ar, moslemi n, abadi hk. histologic evaluation of bone healing following application of anorganic bovine bone and β-tricalcium phosphate in rabbit calvaria. j dentistry, tehran university of medical sciences, tehran, iran 2012; 9(1): 35-40). 13. luu h, kraut d, graves d, gerstenfled l. diabetes interferes with the bone formation by affecting the expression of transcription factors that regulate the j bagh college dentistry vol. 28(3), september 2016 histological evaluation oral diagnosis 81 osteoblasts differentiation. endocrinol 2003; 144: 35264. 14. botolin s, mccabe lr. chronic hyperglycemia modulates osteoblast gene expression through osmotic and non-osmotic pathways. j cell biochem 2006; 99: 411–24. 15. he h, liu r, desta t, leone c, gerstenfeld lc, graves dt. diabetes causes decreased osteoclastogenesis, reduced bone formation, and enhanced apoptosis of osteoblastic cells in bacteria stimulated bone loss. endocrinol 2004; 145(1): 44752. 16. diniz sf, amorim fplg, bocca al, batista ac, simm gepm, silva ta. alloxan-induced diabetes delays repair in a rat model of closed tibial fracture. braz j med biol res 2008; 41(5): 373-9 17. graves dt, paglia dn, lin s .impact of diabetes on fracture healing. j exp clin med 2011; 3(1): 3-8. 18. soares lg, marques am, guarda mg, aciole jm, pinheiro al, dos santos jn. repair of surgical bone defects grafted with hydroxylapatite + β-tcp and irradiated with λ=850 nm led light. braz dent j 2015; 26(1): 19-25. 19. fulzele k, riddle rc, digirolamo dj, cao x, wan c, chen d, faugere mc. insulin receptor signaling in osteoblasts regulates postnatal bone acquisition and body composition. cell 2010; 142(2): 309-19. j bagh college dentistry vol. 30(3), september 2018 prosthetic status 21 prosthetic status in relation to weight status and occupation among parkinson's disease patients in baghdad-iraq ali farouk al-taweel, b.d.s., h.d.d. (1) alhan ahmed qasim, b.d.s., m.sc. (2) abstract background: the symptoms of parkinson's disease (pd) can lead to problems in movement and coordination that lead to difficulty in maintaining well oral cleaning which can then negatively affect dental status of those patients. the aim of present study: to evaluate prosthetic status in relation to weight status and occupation by age and gender among parkinson's disease patients in baghdad-iraq. methods: the sample consisted of 104 patients with parkinson disease attended to the neurosciences hospital in baghdad city / iraq, aged 60-79 years prosthetic status was recorded according to who(1997). weight status was recorded according to trowbridge 1988 and occupation was recorded according to erikson and goldthorpe (1992) and ganzeboom et al (1989). results: the subjects without prosthesis tend to be more from any prosthesis type followed by partial denture and bridge, all types of prosthesis found to be decreased with increasing of age in both arches except combination of bridge and partial denture and complete denture were found to be increased with increasing of age with statistically highly significant association between age and prosthesis in upper arch. males were found to have more prosthesis than females but with statistically no significant association. the subjects without any prosthesis, both bridge and partial denture types in upper arch found more in normal weight than the over and obese ones, while the combination of bridge and partial denture with complete denture tend to have slightly more in over weight with highly significant association. in lower arch other two prosthesis categories tend to be more in overweight subjects than other their counterparts with equally distributed of partial denture between normal and obese ones whose this prosthesis tend to be more than the overweight ones with statistically significant association. the with+ without+ selfemployees category tends to have no prosthesis, partial denture and bridge prostheses more than other their counterparts with approximately equally distributed of other prosthesis categories but with statistically no significant association in upper arch while in lower arch the percentage of subjects with free prosthesis was found in with+ without+ self-employees category, while the partial denture and bridge found to be more in with+ without+ selfemployees and upper grade professional but these findings tend to be statistically no significant association. conclusion: age, gender, occupation and weight have an effect on prevalent of prosthetic status of parkinson’s disease patients. this may be due to difference in previous oral hygiene, health awareness, severity of parkinson’s disease and difference in income status between them. keywords: parkinson disease, weight status, prosthetic status, occupation. (j bagh coll dentistry 2018; 30(3): 21-27) introduction parkinson’s disease (pd) is the second most common neurodegenerative disorder after alzheimer disease and it's the first most common movement disorder (1-3). it is a chronic progressive neurodegenerative disorder with a multifactorial etiology, and it's a chronic and progressive movement disorder, meaning that symptoms continue and worsen over time (4). pd involves the death of vital nerve cells in the brain called neurons, primarily affects neurons in an area of the brain called the substantia nigra. some of these dying neurons produce dopamine, a chemical that sends messages to the part of the brain that control movement and coordination; whenever, parkinson's disease progresses, the amount of dopamine produced in the brain decreases, leaving a person unable to control movement normally (5-6). (1) m.sc. student, department of pedodontics and preventive dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, university of baghdad. the mean age of pd onset is about 60 years (7). the frequency of pd increases with aging, and based on projected population demographics as it is estimated that the prevalence will dramatically increase in future decades (7). the cause of pd is generally unknown, but believed to involve both genetic and environmental factors (5-8). data from several studies suggest that environmental factors may be more important than genetic factors in risk of pd (9). moreover, environmental exposures are often potentially modifiable and can be especially useful in disease prevention. numerous epidemiological studies have reported associations of parkinson's disease with mid or late-life factors such as smoking, coffee drinking, and exposures to pesticides (5). however, few studies have evaluated potential roles of early life factors in pd development primarily due to the difficulty in exposure assessment (10). on the other hand, the hypothesis that early life factors may contribute to pd late in life is appealing. the pre and postnatal periods are vital time spans for brain development, during which the generation, migration and proliferation of neurons is https://en.wikipedia.org/wiki/neurodegeneration https://en.wikipedia.org/wiki/idiopathy https://en.wikipedia.org/wiki/heredity j bagh college dentistry vol. 30(3), september 2018 prosthetic status 22 completed, and the fundamental structure of the brain is established (11). in support of this hypothesis, endotoxin injection into gravid rats induced dopamine neuron loss among new births, indicating that prenatal infection might contribute to pd development (12-13). several studies have concordantly shown that patients with pd have lower body weights (bw) in comparison with age-matched subjects (14-15). their lower body weight may affect patients’ overall functional ability and their daily activities (16-17). a longitudinal study found loss of body weight despite increased energy intake among pd patients, indicating that loss of body weights is caused by increased energy expenditure (18-19), and also contradicted or increased body weights (20). the possible natural history of body weight in pd may include both periods with gain of weight and loss of weight (21). one study reported that the number of dysautonomic disturbances, but not single disturbances (dysphagia, sialorrhea, constipation), was associated with nutritional deterioration along with the disease status assessed by hoehn and yahr stage and levodopa dose (22). not all studies report a low body mass index (bmi)(15). change in bmi is an important clinical feature that should be followed even in early pd (23). thus, it is unsurprising that numerous aspects of the environment have already been investigated with evidence accumulating that occupation-related exposures may be important (24-26). notably, while alzheimer’s disease research unequivocally indicates occupations reflecting low socioeconomic status (27), or low complexity of work (28), as risk factors, the picture is less clear, if not reversed, in research with pd. specifically, higher education (24-29) and higher-status occupations(24-26) have been associated with a higher risk of pd or the results were null (9). these findings are not well understood. both education and occupational status may differentiate individuals based on intellectual engagement in various aspects of life. occupational complexity is another, more refined way to measure intellectual engagement at work (30). as the success of dentures depends, to a large extent, on the wearer's ability to control them with their oral musculature and the presence of an adequate quantity and quality of saliva, the muscle incoordination, rigid facial muscles and xerostomia of pd conspire to jeopardise denture retention and control (31-35). denture problems can influence nutritional intake, dietary enjoyment, self-esteem, social interaction and social acceptability, as well as causing embarrassment to the individual. they are likely to compound the existing difficulties that people with pd have when eating and swallowing (36-34). to date no previous study had been conducted to determine the prosthetic status and prosthetic need among pd patients in iraq. for all the above it was decided to conduct this study concerning prosthetic status of this special group of population. materials and methods the sample cases involved adults with pd patients consisted of 104 (80 males and 24 females) aged between 60-79 years old according to the last birthday (37). collection sample (cases includes all pd patients), firstly, diagnosed by the specialist as having different type of movement disorder attended to the neurosciences hospital in baghdad city in iraq for diagnosis, treatment and follow up. the study was approved by the research committee of dentistry collage, baghdad university and a written consent statement was signed by all subjects before any examination. examination and assessments of prosthetic status were performed according to the basic method of oral survey of world health organization 37; the presence of prostheses should be recorded for each jaw if no prosthesis, bridge, more than one bridge, partial denture, both bridge and partial denture(s) and full removable denture (37). measurement of patients weight and height performed according to trowbridge (38). bmi is a number calculated from pd weight and height. according to this formula (38): body weight / (height)2 = b m i kg/m2 (kg) (m)2 for adults 20 years old and older, bmi are the same for men and women of all body types and ages (38). classification of occupation information performed according to the erikson, goldthorpe and portocarero occupational class scheme from erikson and goldthorpe and ganzeboom et al (41). fisher exact test (f.e.t) was done by using statistical package for the social sciences (spss) version 21. results upper arch: in the present study table 1 illustrates that for the total sample the highest percentage of prosthetic status is the subjects free from any type of prosthesis in their mouth followed by partial denture and bridge respectively while the lowest was the combination of bridge and partial denture and complete denture respectively. regarding age, all types of prosthesis for the total sample found j bagh college dentistry vol. 30(3), september 2018 prosthetic status 23 to be decreased with increasing of age except combination of bridge and partial denture and complete denture were found to be increased with increasing of age with statistically significant association between age and prosthesis in upper arch using fisher exact test, about gender, number of males for the total sample were found to have more prosthesis than those of females but with statistically no significant association. table 1: distribution of prosthetic status in upper arch by total and in age and gender. age (years) 60-69 70-79 f.e.t pvalue total no. % % t no. % % t 20.014 0.000 hs no. % t no prostheses 41 74.55 39.42 14 25.45 13.46 55 52.88 bridge 16 100.0 15.38 0 0.00 0.00 16 15.38 partial denture 17 68.00 16.35 8 32.00 7.69 25 24.04 bridge + partial denture 1 20.00 .96 4 80.00 3.85 5 4.81 complete denture 0 .00 .00 3 100.00 2.88 3 2.88 gender males females no. % % t no. % % t 0.855 0.990 ns no prostheses 42 76.36 40.38 13 23.64 12.50 bridge 13 81.25 12.50 3 18.75 2.88 partial denture 19 76.00 18.27 6 24.00 5.77 bridge + partial denture 4 80.00 3.85 1 20.00 0.96 complete denture 2 66.67 1.92 1 33.33 0.96 t=total, hs=highly significant at p<0.01, ns=not significant p>0.05, f.e.t= fisher exact test. about nutritional status and occupation finding table 2 shows for the total sample that subjects without any prosthesis found more in normal weight subjects with equally distributed in both over and obese ones, both bridge and partial denture types found also in normal more than the other two categories, while the combination of bridge and partial denture with complete denture tend to have more in over weight than other two categories. the with+ without+ self-employees category for the total sample tends to have no prosthesis, partial denture and bridge prostheses more than other their counterparts with approximately equally distributed of other prosthesis categories but with statistically no significant association. table 2: distribution of prosthetic status in upper arch by nutritional status and occupation. nutritional status normal overweight obese no. % % t no. % % t no. % % t no prostheses 19 34.55 18.27 18 32.73 17.31 18 32.73 17.31 bridge 8 50.00 7.69 3 18.75 2.88 5 31.25 4.81 partial denture 16 64.00 15.38 0 .00 .00 9 36.00 8.65 bridge+ partial denture 2 40.00 1.92 3 60.00 2.88 0 .00 .00 complete denture 0 .00 .00 2 66.67 1.92 1 33.33 .96 f.e.t=21.065, p-value=0.001 hs. occupation upper grade professionals lower grade professionals non-manual employees with+ without+ self-employees no. % % t no. % % t no. % % t no. % % t no prostheses 7 12.73 6.73 16 29.09 15.38 11 20.00 10.58 21 38.18 20.19 bridge 5 31.25 4.81 2 12.50 1.92 2 12.50 1.92 7 43.75 6.73 partial denture 8 32.00 7.69 5 20.00 4.81 2 8.00 1.92 10 40.00 9.62 bridge+ partial denture 0 .00 .00 2 40.00 1.92 2 40.00 1.92 1 20.00 .96 complete denture 1 33.33 .96 0 .00 .00 1 33.33 .96 1 33.33 .96 f.e.t=12.560, p-value=0.313ns. t=total, hs=highly significant at p<0.01, ns=not significant p>0.05, f.e.t= fisher exact test. j bagh college dentistry vol. 30(3), september 2018 prosthetic status 24 lower arch: concerning to age and gender, table 3 demonstrates for the total sample that subjects without prostheses tend to be more any prosthesis type followed by partial denture and bridge respectively with equally distributed of combination of bridge and partial denture with complete denture respectively and these results were same as previous when compared prosthesis distributions between two age groups, found to be decreased with increasing of age except combination of bridge and partial denture and complete denture were found to be increased slightly with increasing of age with statistically significant association, the percentage of males with partial denture was more than that of females with statistically no significant association. table 3: distribution of prosthetic status in lower arch by total and in age and gender. age (years) 60-69 70-79 f.e.t p-value total no. % % t no. % % t 7.352 0.047 sig. no. % t no prostheses 68 73.91 65.38 24 26.09 23.08 92 88.46 bridge 4 100.0 3.85 0 .00 .00 4 3.85 partial denture 3 50.00 2.88 3 50.00 2.88 6 5.77 bridge + partial denture 0 .00 .00 1 100.00 .96 1 .96 complete denture 0 .00 .00 1 100.00 .96 1 .96 gender males females no. % % t no. % % t 6.319 0.127 ns no prostheses 71 77.17 68.27 21 22.83 20.19 bridge 2 50.00 1.92 2 50.00 1.92 partial denture 6 100.0 5.77 0 .00 .00 bridge + partial denture 1 100.0 .96 0 .00 .00 complete denture 0 .00 .00 1 100.00 .96 t=total, sig. =significant at p<0.05, ns=not significant at p>0.05. while nutritional status and occupation are shown in table 4 finding for the total sample that percentage of subjects with no prostheses is more in normal weight ones than other two categories, while the other prosthesis categories tend to be more in overweight subjects than other their counterparts with equally distributed of partial denture between normal and obese ones whose this prosthesis tend to be more than the overweight ones with statistically significant association, also the percentage of subjects with free prosthesis was found in with+ without+ selfemployees category , while the partial denture and bridge found to be more in with+ without+ selfemployees and upper grade professional but these findings tend to be statistically no significant association. table 4: distribution of prosthetic status in lower arch by nutritional status and occupation. nutritional status normal overweight obese no. % % t no. % % t no. % % t no prostheses 42 45.65 40.38 21 22.83 20.19 29 31.52 27.88 bridge 0 .00 .00 3 75.00 2.88 1 25.00 .96 partial denture 3 50.00 2.88 0 .00 .00 3 50.00 2.88 bridge+ partial denture 0 .00 .00 1 100 .96 0 .00 .00 complete denture 0 .00 .00 1 100 .96 0 .00 .00 f.e.t=11.994, p-value=0.035 sig. occupation upper grade professionals lower grade professionals non-manual employees with+ without+ self employees no. % % t no. % % t no. % % t no. % % t no prostheses 17 18.48 16.35 23 25.00 22.12 16 17.39 15.38 36 39.13 34.62 bridge 1 25.00 .96 1 25.00 .96 0 .00 .00 2 50.00 1.92 partial denture 3 50.00 2.88 0 .00 .00 1 16.67 .96 2 33.33 1.92 bridge+ partial denture 0 .00 .00 1 100.0 .96 0 .00 .00 0 .00 .00 complete denture 0 .00 .00 0 .00 .00 1 100. .96 0 .00 .00 f.e.t=11.514,p-value=0.403 ns t=total, sig.= significant at p<0.05, ns=not significant at p>0.05, f.e.t= fisher exact test. j bagh college dentistry vol. 30(3), september 2018 prosthetic status 25 discussion higher proportion of examined pd patients in this study had no prosthesis in upper and lower arches. the common prosthetic types in upper arch of pd patients in this study were partial denture, bridge and a combination partial denture and bridge and complete denture with lesser extent in lower arch. these findings are close to results of previous study carried out in bangladesh which stated that complete denture patients and due to their continuous tremors cannot keep their previous prosthesis for long time and the common found prosthesis were partial implant (42), and findings of previous chinese study which also encouraged application of a magnetic attachment system in an implantsupported mandibular overdenture for an edentulous patient with pd (43). no significant differences were observed in prosthesis of pd patients regarding gender, however, the prosthesis types were more occurred among male pd patients. an indian study carried out in geriatric home on healthy elderly population, found that most of elderly peoples had no prosthesis and the males had more prosthetic bridges and partial dentures than females (44). the prosthetic bridge, partial denture and complete denture in the present study were significantly higher among overweight and obese pd patients in both arches. a wide variety of studies noted the relationship between poor chewing ability and obesity in healthy elderly population (45). as a result; elderly obese peoples tend to rehabilitate their missed teeth with prosthesis (46). concerning occupation the prosthetics in the present study were more predominant among self-employees than professional pd patients in both arches with no significant differences. these finding were inconsistent with results of previous study examining the socioeconomic effect on number of prosthetics used also baran et al documented that educational level and socioeconomic status of population in turkey had a significant effect 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of removable dentures. eur j dent. 2007; 1(2):104-10. ةالخالص مرض الشلل الرعاشي ممكن ان تؤدي اعراضه الى مشاكل بالحركه االراديه والالاراديه وتناغم وتناسق الحركات العضليه والعصبيه مقدمه: للفم لالطراف العلويه والسفليه التي ممكن ان تسبب صعوبه بالمحافظه على نظافه الفم واالسنان وممكن ان تؤثر بشكل سلبي على الحاله الصحيه .لهذه الفئه من المرضىواالسنان لمعرفه حاله التعويضات االصطناعيه السنان المرضى وعالقتها بالوزن والمهنه نسبه الى العمر والجنس لمرضى الشلل الرعاشي اهداف البحث: العراق-في مدينه بغداد العراق, تتراوح -شخص مصاب بمرض الشلل الرعاشي يراجعون مستشفى العلوم العصبيه في مدينه بغداد 401العينه تتكون من طريقه العمل: والوزن سجل 4779سنه, حاله تعويضات االصطناعيه لالسنان سجلت حسب تعليمات منظمه الصحه العالميه لسنه 97الى 00اعمارهم من .ganzeboom 4717 erikson, goldthorpe 4771 تقسيم فئات العمل حسب تعليماتو trowbridge 4711حسب تعليمات مجموعه المرضى الذين اليوجد لديهم تعويضات صناعيه يميلون لكونهم المجموعه االعلى من بين الحاالت متبوعه بتعويض االسنان النتائج: بأزدياد العمر بالفكين العلوي والسفلي ماعدا في حاله التعويضات الصناعيه الجزئي والجسور التعويضيه, كل الحاالت التعويضيه الموجوده تقل ه في الجزئيه والجسوربينما التعويضات الصناعيه الكامله تزداد بازدياد العمر مع ترابط احصائي عالي الوضوح بين العمر والتعويضات الصناعي j bagh college dentistry vol. 30(3), september 2018 prosthetic status 27 والمرضى بدون تعويضات صناعيه وكل من الناث مع عدم وجود ترابط احصائيكما وجد تعويضات صناعيه عند الذكور اكثر من ا .الفك العلوي ا مجموع الجسور والتعويضات الصناعيه الجزئيه في الفك العلوي اعلى في حاله الوزن الطبيعي مقارنه بزياده الوزن الخفيفه والسمنه المفرطه بينم كامله تميل لتكون المجموعه اعلى بقليل من مجموعه زياده الوزن الخفيفه التعويضات الصناعيه الجزئيه والجسور والتعويضات الصناعيه ال في الفك السفلي التعويضات الصناعيه الجزئيه والجسور تميل لتكون المجموعه االكثر بزياده الوزن الخفيفه عن .وبترابط احصائي عالي الوضوح الوزن الطبيعي والسمنه المفرطه وهذان اكثر من زياده الوزن الخفيفه مع وجود بقيه االوزان مع توزيع متساوي للتعويضات الصناعيه الجزئيه بين تميل لعدم استخدام التعويضات الصناعيه والتعويضات الصناعيه ( الخاصه االعمال واصحاب والعاطلين العمال)ترابط احصائي. فئه العمل الرابعه د ترابط احصائي في الفك االعلى بينما في الفك االسفل نسبه المرضى لعدم وجود الجزئيه والجسور اكثر مع توزيع تقريبا متساوي لكن اليوج كثر في التعويضات الصناعيه اكثر في فئه العمل الرابعه )العمال والعاطلين واصحاب االعمال الخاصه( بينما التعويضات الصناعيه الجزئيه توجد ا والفئه االعمال العاليه مع عدم وجود ترابط احصائي. ( الخاصه االعمال واصحاب والعاطلين العمال)فئه العمل الرابعه ان حاله التعويضات الصناعيه تزيد بازدياد العمرلمرضى الشلل الرعاشي وعدد التعويضات المستخدمه في هذه الدراسه وجد االستنتاجات: االعمال الخاصه وكذلك عند زياده الوزن الخفيفه والسمنه لمرضى الشلل الرعاشي شائعه عند الذكور اكثر من االناث والموظفين اكثر من اصحاب المفرطه للمرضى في كال الفكين العلوي والسفلي. j bagh college dentistry vol. 29(2), june 2017 effect of modified restorative dentistry 49 effect of modified nanohydroxyapatite fillers addition on some properties of heat cured acrylic denture base materials ruaa hameed karadi, b.d.s, m.sc. (1) basima m.a. hussein, b.d.s., m.sc., ph.d. (2) abstract background: poly (methylmethacrylate) is not ideal in every aspect and has disadvantages such as insufficient surface hardness, increase water sorption and poor impact resistance and the latter being the primary cause of fracture of denture base resins. the aim of this study was to evaluate the effect of addition of silanized nano hydroxyapatite (ha) on some properties of heat cured acrylic denture base material. materials and methods: ha nano particles were first silanized with mps (tri methacryloxypropyletrimethoxy silane coupling agent) then ultrasonicated with methylmethacrylate (monomer) to disperse agglomerated nano particles and mixed with polymer. 2% by wt of ha nano particles was selected as the best concentration that added to the denture base material according to the pilot study.(100) specimens were prepared by conventional water bath processing technique and divided to two groups: 50 specimens for control group or 0% ha and 50 for experimental group or 2% ha then each group was subdivided to five groups with 10 specimens for each test: impact strength, transverse strength, surface hardness, surface roughness, water sorption and water solubility. results: highly significant increase in impact strength and surface hardness after addition of 2% ha nano particles but not significant decrease in water sorption whereas solubility was significantly decreased. surface roughness was significantly increased as compared with control group but remained within the acceptable limit less than 2m. ha nanoparticles addition highly decreased the transverse strength value. conclusion the addition of 2% ha nano particles considerably improved the impact strength, surface hardness and had positive effect on water sorption and solubility. whereas the same concentration tend to highly decreased transverse strength and increase surface roughness. keywords: poly methylmethacrylate, ha nanoparticles, mps (tri methacryloxypropyletrimethoxy. (j bagh coll dentistry 2017; 29(2):49-54) introduction since first polymerized by walter bauer in 1936, acrylic resin denture base gradually took the place of traditional metal base and became most commonly used denture base material in clinical fabrication (1). it is a combination of advantages rather than one excellent aspect that accounts for its wide usage, including its popularity in satisfying aesthetic demands and clearly defined processing method in dentistry application. this material is not ideal in every aspect, especially when meeting with mechanical requirements of prosthesis (2). the primary problem of pmma is its poor strength characteristics, low impact strength and fatigue resistance (3). thus, there is a need to improve the performance of pmma in denture base application. several methods have been used to modify the properties of pmma denture base materials. among these methods is strengthening the acrylic resin prosthesis by modifying or reinforcing the resin with fiber, and graft copolymerization with high-impact resins (4,5). however, fabrication of properly oriented fibers added in the resin is technically difficult and random dispersion would even result some defects (6). (1) ministry of health, baghdad/ al-rusafa health office (2)assist. prof. dep.of prosthodontics, college of dentistry, university of baghdad. the introduction of nano dentistry in the last years as well as the great advantages of nanofiller in reinforcing the mechanical properties of denture base materials led to introduction of polymer nanocomposites, which are materials contain nanoscopic inorganic particles, typically 10-100 nanometer in at least one dimension, are dispersed in an organic polymer matrix in order to dramatically improve the performance properties of the polymer (7). also clinical application of denture base not only requires excellent mechanical performance, but also expects good biocompatibility and biosafety, while some inorganic materials may cause irritation or even damage to gingival tissue and mouth mucosa (8,9). it was reported that hydroxyapatite nanopowder had been used in dental material as an effective biocompatible filler to reinforce self-cured polymer matrix (10). ha is natural biosafety material and widely used in ceramic for its excellent biocompatibility with tissues and skin (9). as any inorganic filler the mechanical properties of pmma/ha composites could be limited by the incompatibility between the pmma and ha. it was found that the silane coupling agent [3-methacryloxypropyltrimethoxy silane (γ-mps)] can improve the mechanical and physical properties of pmma/nano ha significantly owing to the better adhesion (11). a novel kind of acrylic resin studied in this research by incorporating of hydroxyapatite (ha) j bagh college dentistry vol. 29(2), june 2017 effect of modified restorative dentistry 50 ca10(po4)6(oh)2 to improve the mechanical properties of heat cured denture base materials. materials and methods materials the most important component used in this study were heat cured acrylic powder and liquid (vertex, netherlands).hydroxy apatite nanoparticles with 20nm for diameter and 97% purity (mk nano ,canada) , mps , methanol and glacial acetic acid (sigma aldrich germany) method -silanation of hydroxyapatite nano particles ha nanoparticles were silanized using 3methacryloxypropyltrimethoxy silane (γ-mps) in 90/10 methanol/distilled water solution .(11,12) about 30 gm of ha nano particles were mixed by prob sonicator (soniprep-150, england) for 2 hours. ph of the result solution was adjusted with glacial acetic acid until ph meter( eutech instrument, germany) recorded 3.5-4 then 3 ml of mps was added under vigorous magnetic stirring (hanna instrument hi300, china) for 12 hours. methanol and distilled water were evaporated by air and heat drying then the silanized ha powder was tested by fourier transformes infrared machine (shimadzue,ftir-8400s,japan) to check for functional groups. preparation of acrylic specimens three different plastic patterns were constructed by cutting plastic plate in desired shape and dimension by using laser cutting machine according to the required test. to test the impact strength :abar shaped specimen with dimensions of (80 mm x10 mm x 4 mm) length, width and thickness respectively(13) (iso.179-1, 2000 for un notched specimens). a bar shaped specimen with dimensions of (65mm x 10 mm x 2.5 ± 0.1 mm) length, width, thickness respectively was used to test transverse strength(14) (ada no. 12, 1999). same specimen's measurements were used to prepare samples to test surface roughness and hardness of the tested materials. water sorption and solubility tests: disc with dimensions of 50 mm in diameter and 0.5 mm in thickness (14) (ada no. 12, 1999) was prepared. -mold preparation conventional water bath flasking technique for complete dentures construction was followed during the mold preparation and processing -proportioning and mixing a pilot study was conducted to estimate the most suitable ha nanoparticles concentration .2% showed the best results regarding impact and transverse strength test. addition of hydroxyapatite nano particles 2% of modified ha nano filler powder was added by weight to monomer to prepare the experimental group specimens. an electronic balance with accuracy of 0.0001g (sartorius. germany) was used to determine the exact pmma and ha nano powder weight. the appropriate weight of ha nano filler was added to the selected monomer volume following manufacturer instruction regarding p/l ratio, the filler was dispersed very well in the monomer by probe sonicater apparatus (120w, 60khz) for three minutes(15). the suspension of monomer with ha nano filler was immediately mixed with acrylic powder to reduce the possibility of particle agglomeration and phase separation. the mixing was carried out in a clean and dry mixing vessel by a clean wax knife for 30 second. the mixture was then covered and left to stand until a dough stage was reached approximately 30 min according to manufacturer’s instruction. mechanical and physical tests impact strength test impact strength test was conducted following the procedure recommended by the iso 179 with charpy type impact testing instrument (n 43-1, new york, usa). ten specimens were constructed for control and experimental groups. each one was supported horizontally at its ends and struck by a free swinging pendulum of 2 joules testing capacity was used). the charpy impact strength of unnotched specimen was calculated in kj/mm2 according to this equation impact strength = . x103 (16)(anusavice, 2008) e: is the impact absorbed energy in joules. b: is the width in millimeters of the specimens. d: is the thickness in millimeters of the specimens. transverse strength test ten specimens were constructed for each group and tested for transverse strength by the use of instron testing machine (instron corporation, 1122, canton mass). the specimen was horizontally positioned on bending fixture, consisting of 2 parallel supports (50) mm apart, load was applied with cross head speed of 1mm/min by rod placed centrally between the supports making deflection until fracture occurred. calculation of transverse strength in n/mm² according to this equation . transverse strength = 3 /2 ² ,where p: is the peak load. l: is the span length in millimeter. b: is the sample width in millimeter. d: is the sample thickness in millimeter.(16) surface hardness test j bagh college dentistry vol. 29(2), june 2017 effect of modified restorative dentistry 51 the shore d hardness (210 time group italy)was used in this test which consists of spring loaded metal indenter point (0.8mm diameter) with a screen from which the hardness value was read directly on a digital scale. each one of the ten specimens was divided in to five equal area and five measurements were recorded from the center of each area. the average of five reading was calculated representing the hardness value of the specimens. surface roughness test a portable surface roughness tester or profilometer(srt-6210 ,england) were used to test ten specimen for both control and experimental groups .this device has a diamond stylus which moves in contact with surface for 11 mm. three measurements were done at 3 positions across each specimen surface which was divided in to 3 equal thirds and the mean of the 3 reading were recorded, as a roughness measurement. water sorption and solubility test ten specimens were prepared for each group and dried by placing them in a desiccator containing silica gel. the desiccator stored in an incubator at 37°c ± 2 for 24 hours, and then the specimens were removed from the incubator and remained at room temperature for 1 hour after that the specimens weighed with digital balance. this procedure was repeated until a constant mass "conditioned mass”(m1) was reached.then all discs of two groups were immersed separately in distilled water inside incubator for 7 days at 37°c ± 2°c (14). then, the discs were removed from the water and weighed one minute after removal from the water; this mass was recorded as (m2) (the mass of the disc after conditioning). water sorption was calculated in mg/cm² and calculated according to this equation. wsp = m2 –m1 /s wsp: water sorption in (mg/cm2) m2: the mass of the disc after immersion in distilled water (mg) m1: the mass before immersion in distilled water (conditioned mass) (mg) s: surface area of the disc (cm2) in order to measure solubility of the material, the specimens were placed in the desiccators containing silica gel incubated at 37°c ±2 °c. the specimens were weighed every 24 hours until a constant weight (m3) was reached. water solubility was calculated in mg/cm² according to this equation. wsl = m1—m3 s wsl: solubility (mg/cm2) m1: the conditioned mass (mg) m3: the reconditioned mass (mg) s: the surface area of the disc (cm2) results ftir spectrum for sample of nano hydroxyapatite before silanization presented in fig (1) bands at 560,640,963 and 1028 to 1110cmˉˡ correspond to phosphate group and band at 3572cmˉˡ to structural ohˉ. modified hydroxyapatite has the same spectrum but with the presence of extra peaks of vinyl c=c, carbonyl c=o and methyl group detected at 1638cmˉˡ , 1718cmˉˡand 1455 cmˉˡ which are the required functional groups as shown in fig (2) figure 1: ftir of pure ha figure 2: ftir of silanized ha the results were analyzed using spss. version 19and ttest was used to determine the difference at a level of significance 0.05 in which p-value more than 0.05 considered as statistically non-significant, less than 0.05 accepted as significant and less than 0.01 accepted as highly significant. mean values, standard deviation, standard error and independent t tests results for all the tests conducted in this study are presented in tables 1-5. regarding impact strength the higher mean value appeared in experimental group as compared with control group. high significant difference resulted at p value of 0.000 as shown in table (1) j bagh college dentistry vol. 29(2), june 2017 effect of modified restorative dentistry 52 table 1: impact strength in (kj/mm²). control group (0% nano filler) experimental group2% nanofiller no.of specimens 10 10 mean 8.1723 11.1419 sd 0.47119 0.62091 se 0.14900 0.19635 t value -12.048 p value 0.000 significance hs for transverse strength test mean value of control and experimental groups are 105.3738 and 94.02 n/mm2 respectively. independent t test showed high significant difference between them as shown in table (2) table 2: transverse strength test results in (n/mm2) control group) 0% nano filler (experimental group)2% nanofiller no.of specimens 10 10 mean 105.3738 94.0200 sd 5.75066 8.76685 se 1.81852 2.77232 t value 3.424 p value 0.003 significance hs the experimental group of surface hardness test showed higher mean value as compared with control group. highly significant improvement in surface hardness was seen with p value 0.000 as shown in table (3) table 3: surface hardness test results control group 0% nano filler experimental group 2% nanofiller no.of specimens 10 10 mean 83.3840 86.8310 sd 0.49214 0.95823 se 0.15563 0.30302 t value -10.199 p value 0.000 significance hs as shown in table (4) surface roughness increased in experimental group. independent t test shows highly significant difference with p value 0.002 table 4: surface roughness test results control group 0% nano filler experimental group 2% nanofiller no.of specimens 10 10 mean 1.8300 1.8360 sd 0.0000 0.00516 se 0.0000 0.00163 t value -3.674 p value 0.002 significance hs anon significant reduction in water sorption was seen between control and experimental groups, table (5) table 5: water sorption test results in (mg/cm2) ( control group) 0% nano filler (experimental group) 2% nanofiller no.of specimens 10 10 mean 0.35632 0.34483 sd 0.065351 0.021334 se 0.02067 0.00675 t value 0.529 p value 0.060 significance ns water solubility mean value decreased in experimental group as compared with control group. independent t test with a p value of 0.000 show high significant reduction between them as shown in table (6) table 6: water solubility test results in (mg/cm2) control group 0% nano filler experimental group 2% nanofiller no.of specimens 10 10 mean 0.0657 0.0492 sd 0.00815 0.00729 se 0.00258 0.00230 t value 4.656 p value 0.000 significance hs discussion 3-methacryloxy propyltrimethoxy silane (mps) was used to silanized hydroxyapatite nano particles in which methoxy group in si-o-ch3 readily hydrolyze and react with hydroxy apatite nano j bagh college dentistry vol. 29(2), june 2017 effect of modified restorative dentistry 53 particles to form stable si-o-ha. on the other side vinyl group c=c can react with vinyl group of pmma during polymerization reaction and this allow better dispersion of ha and high interfacial bonding with pmma as demonstrated in fig (3). figure 3: inter action of hydroxyapatite  mps and pmma. (11) the addition of 2% nano hydroxyapatite to pmma resulted in highly significant increase in impact strength and this may be due to treating particles with coupling agents which improve inter facial bonding between them. on the other hand the small size and low concentration of ha nanoparticles helped in well dispersion and embedding in polymer matrix and this positively affected the impact strength. in this study transverse strength was adversely effected by the addition of ha nanoparticles and this may be due to the plasticizing effect of (mps) coupling agent (17) (18) .shore d hardness tester was used to test hardness properties in this study and showed significant increase in surface hardness of 2% acrylic specimens and this may be explained on the basis of two reasons: one of them might be high inter facial bonding between nano particles with polymer matrix, good dispersion, equal distribution of particles in the polymer matrix and these improved by silanation of ha particles and the other reason might be the incorporation of ha which represent the main mineral component of hard dental tissues that responsible for their hardness and other mechanical properties (19). highly significant increase in surface roughness of unpolished surface after addition of 2% nano hydroxyapatite to pmma as compared with 0% or unfilled pmma was observed.this change can be considered uninfluential since significant surface bacterial colonization occurs when the roughness is more than 2m(20).any how regular cleaning and disinfecting the denture can solve the problem. therefore the significant increase in surface roughness may be statistical and clinically uninfluential. it was found that water sorption of experimental group decreased but statistically not significant at the same time there was highly significant decrease in water solubility after addition of 2% of ha which is the result of mps modified ha nanoparticles and the ability of mps to react with hydroxyl groups in the ha filler converting it from hydrophilic to hydrophobic molecule (21). conclusion  mps treated hydroxyapatite nanoparticles successfully enhanced dispersion and interfacial bonding with polymer matrix. the addition of 2% hydroxyapatite nano particles considerably improved the impact strength, surface hardness and had positive effect on water sorption and solubility. whereas the same concentration tend to highly decreased transverse strength and increase surface roughness references 1 kim yk., grandini s,ames jm et al.critical review on methacrylate resin-based root canal sealers journal of endodontics. 2010, 36, pp. 383–399 2 nejatian t,johnson a, noort rv. ”reinforcement for denture base resin “ advanced sciences and technologies2006, 4: pp. 124–129. 3 kim sh, watts dc. the effect of reinforcement with woven e-glass fibers on the impact strength of complete dentures fabricated with high-impact acrylic resin the journal of prosthetic dentistry 2004, 91, 274– 280. 4 john j, gangadhar a, shah ., “flexural strength of heat-polymerized polymethyl methacrylate denture resin reinforced with glass, aramid, or nylon fibers.”the journal of prosthetic dentistry 2001, 86:424-7 5 moreno-maldonado ls, acosta-torres fh,barcelosantana et al. “fiber-reinforced nanopigmented poly(methyl methacrylate) as improved denture base” journal of applied polymer science 2012, 126, pp. 289–296. 6 carlos n.b and harrison a.the effect of untreated uhmwpe beads on some properties of acrylic resin denture base materialjournal of dental material 1996, 25, pp. 59–64. 7 lagashetty a,venkataraman a. polymer nanocomposites resonance 2005,10(6). 8 ambrosio l, peluso g,davis pa. biocompatibility of hydroxyapatite ceramic-response of chondrocytes in a test system using low-temperature scanning electron-microscopy journal of dental materials1989, 17, pp. 21–27 9 bose ,banerjee “synthesis, processing, mechanical, and biological property characterization of hydroxyapatite whisker-reinforced hydroxyapatite composites” journal of the american ceramic society 2009, 92, pp. 323–330. 10 zebarjad sm, sajjadi sa, sdrabadi te, yaghmaei a, naderi b. a study on mechanical properties of pmma/hydroxyapatite nanocomposite engineering 2011, (3)795-801. j bagh college dentistry vol. 29(2), june 2017 effect of modified restorative dentistry 54 11 tham wl, chow ws, mohd ishak za.“simulated body fluid and water absorption effects on poly(methyl methacrylate)/hydroxyapatite denture base composites” express polymer letters 2010, 4(9):517–528. 12 wang sh,wen sh, shen m, guo r,cao x.,wang j, sh x. aminopropyltriethoxysilane-mediated surface functionalization of hydroxyapatite nanoparticles: synthesis, characterization ,and in vitro toxicity assay international j nanocomposite 2011 6: 3449– 3459. 13 iso 179-1:2000: plastics -determination of charpy impact properties -part 1: non-instrumented impact test 14 american dental association specification no. 12 (1999) for denture base polymers. chicago. : council on dental materials and devices 15 mohammed a, solhil, nodehi a, mirabedini sa, kasraei s, akbari k, babanzadeh s. "pmmagrafted nano clay as novel filler for dental adhesives". dent. mater 2009, 25:339-347. 16 anusavice kj "philips science of dental material". 11th ed, middle east and african edition 2008, ch7, ch22, p: 143-166,721-756. 17 nazhat sn, smith r, deb s, wang m, tanner ke, bonfield w. "dynamic mechanical behavior of modified hydroxyapatite reinforced polyethylene composites" trans. 5th. world biomaterials congress, toronto1996, pp.ii-83. 18 deb s, wang m,tanner ke, bonfield w "hydroxyapatite-polyethylene composites: effect of grafting and surface treatment of hydroxyapatite," j. mater. sci. : mater. in med 1996. 7, 191-193 19 junqueira, carlos l, carneiro j. eds. basic histology, text & atlas (10th ed.). mcgraw-hill companies 2003. p. 144 20 quirynen m, marechal m, busscher hj, weerkamp ah., dariusp,steerberghe d.”the influence of surface free energy and surface roughness on early plaque formation : an in vivo study in man”.j clin periodontal 1990 ,17:138-144. 21 santos c, luklinska z b, clarke r l, davy kw hydroxyapatite as a filler for dental composite materials: mechanical properties and in vitro bioactivity of composites journal of materials: materials in science 2001, 12, 565–573. . المستخلص النواحي ولھا میزات غیر مرغوبھ مثل قلة الصالده وكثرة امتصاص الماء باالضافھ مادة البولي مثیل میثااكریلیت لیست متكاملھ من كل الخفاقھا في تحمل الصدمھ وھي السبب الرئیسي لكسر قواعد االطقم . یلیت على بعض الھدف من ھذه الدراسھ ھو تقییم تأثیر اضافة الھایدروكسي اباتایت النانویھ والمعاملھ كیمیائیا الى مادة البولي مثیل میثاكر الخواص مثل قوة الصدمھ ،القوة المستعرضھ،الصالده، خشونة السطح، قابلیة االمتصاص والذوبان في الماء . یر المواد وطریقة البحث:تمت معاملة جزیئات الھایدروكسي اباتایت النانویھ بالمادة الرابطھ ثم تحریكھا مع المثیل میثاكریلیت او المونوم وق الصوتیھ لغرض تفریق الجزیئات المتالصقھ ثم خلطھا مع البولي مثیل میثاكریلیت او البولیمر.وفقا لنتائج الدراسھ باستخدام الموجات ف من الھیدروكسي اباتایت النانویھ الضافتھا الى العینات التجریبیھ .تم تحضیر مئة عینھ قسمت الى مجموعتین %2االولیھ تم اختیار نسبة عھ التجریبیھ كل منھما تحوي خمسین عینھ تم تقسیمھا الى خمس مجامیع كل منھا تحوي عشر عینات موزعھ مجموعة السیطره والمجمو حسب االختبارات المستخدمھ وھي قوة الصدمھ، القوه المستعرضھ، الصالده، خشونة السطح، قابلیة االمتصاص والذوبان في الماء . معنویھ في قوة الصدمھ والصالده بعد اضافة الھایدروكسي اباتایت النانویھ . كذلك نقصان النتائج : نتائج التحلیل االحصائي اظھرت زیاده في امتصاص الماء في نفس الوقت انخفاض معنوي في قابلیة الذوبان في الماء وارتفاع معنوي في خشونة السطح ولكن ضمن الحد المقبول ضافھ سببت نقصان معنوي بالقوه المستعرضھ. مایكرومیتر. من ناحیھ اخرى ھذه اال 2للخشونھ وھو اقل من من الھایدروكسي اباتایت النانویھ الى البولي مثیل میثاكریلیت ادى الى زیاده بقوة الصدمھ والصالده باالضافھ %2المحصلھ :ان اضافة قابلیة االمتصاص والذوبان بنفس الوقت اضافة ھذه الماده ادى الى زیادة الخشونھ وانخفاض القوه المستعرضھ . الى التاثیر االیجابي على hussein.doc j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 39 effect of different polishing systems on the surface roughness of full-contour zirconia hussein muhammed wajih, b.d.s. (1) adel f. ibraheem, b.d.s., m.sc. (2) abstract background: adjustment of any premature occlusal contact of any zirconia restoration requires its polishing or glazing in order to restore the smoothness of the restoration. the objective of this in vitro study was to evaluate the effects of different polishing systems and glazing on the surface roughness of full-contour zirconia. material and methods: forty disks (diameter: 8 mm, thickness: 6.4 mm) were prepared from pre-sintered fullcontoured zirconia block; they were colored and sintered in a high-temperature furnace at 1500˚c for 8 hours. the specimens were then leveled and finished using grinding and polishing machine and adjusted using diamond disk. the specimens were then randomly divided into four groups (n=10), group i involves samples that were polished using (karat diamond polishing set, vita zahnfabrik, germany), group ii involves samples that were polished with (zirconia polishing kit, smedent, shanghai, china), group iii involves samples that were polished with (optrafine® diamond polishing system, ivoclar vivadent, germany), while group iv involves samples that were glazed using glazing medium (vita akzent glaze akz 25, vita zahnfabrik, germany). surface roughness values (ra) (in µm) of all the specimens were recorded at each stage of surface treatment of zirconia disks (leveling and finishing, adjustment of the samples and polishing / glazing) using surface roughness tester. statistical analysis was carried out using one-way anova and lsd tests. results: the results showed that the glazing group recorded the lowest surface roughness mean value, followed by (optrafine® polishing system), then (zirconia polishing kit) and finally (karat polishing set) which showed the highest mean of surface roughness. for all groups, there was a statistically very high significant difference of (ra) value before and after adjustment of the samples. moreover, there was a statistically very high significant difference in (ra) value when comparing the adjusted samples with the polished and glazed ones. karat polishing set group showed a statistically highly significant difference with zirconia polishing kit group (p<0.01). both, karat polishing set and zirconia polishing kit groups showed a statistically very highly significant difference (p<0.001) with (optrafine® polishing system) and glazing groups. on the other hand, no statistically significant difference was found between glazing and (optrafine® polishing system) groups (p>0.05). conclusions: adjusting full-contour zirconia with diamond bur or disk resulted in a significant increase in (ra) that necessitates its polishing or glazing to restore the surface smoothness. furthermore, both glazing and optrafine® polishing system provided the best surface smoothness, so glazing can be substituted with chairside polishing using optrafine® polishing system. keywords: surface roughness, zirconia, glazing, polishing. (j bagh coll dentistry 2014; 26(4):39-45). الخالصة إن الھدف من ھذه الدراسة المختبریة ھو لتقییم . یتطلب تلمیعھا أو إعادة تزجیجھا من أجل استعادة النعومة المطلوبة, إن تعدیل أي إطباق مبكر سواء لتركیبات السیرامیك أو الزركون .آثار نظم التلمیع المختلفة و التزجیج على خشونة سطح الزركون المعدل بعد ذلك تم تسویة اسطح العینات و صقلھا بواسطة جھاز ).ساعات 8درجة مئویة لمدة 1500(عینة من الزركون، تم تلوینھا و طبخھا في فرن ذو درجة حرارة عالیة تم تحضیر أربعین المجموعة االولى تم تلمیع أسطح .تحوي عشرة عینات تم تقسیم العینات بعدھا عشوائیا إلى أربع مجموعات كل مجموعة. و بعدھا تم تعدیل أسطح العینات بواسطة قرص ماسي, الصقل المجموعة الثالثة تم تلمیع أسطح عیناتھا , )طقم التلمیع الخاص بالزركون(في المجموعة الثانیة تم تلمیع أسطح العینات بواسطة , ) karatطقم التلمیع الماسي(العینات فیھا بواسطة لجمیع العینات في المراحل ) بالمیكرو متر(تم تسجیل قیم خشونة األسطح .جموعة الرابعة تم تزجیج العینات فیھا بمادة تزجیج مناسبةالم, )®optrafineطقم التلمیع الماسي (بواسطة anova اختبار إلحصائي بتطبیقوقد أجري التحلیل ا). البروفیلومیتر(بإستخدام جھاز قیاس خشونة السطح ) تزجیجھا/ تلمیع العینات,التسویة والصقل، تعدیل سطح العینات (الثالثة .lsdاالتجاه و إختبار احادي طقم (وأخیرا مجموعة , )طقم التلمیع الخاص بالزركون(، ثم مجموعة )®optrafineطقم التلمیع الماسي (أظھرت مجموعة التزجیج أقل متوسط خشونة ألسطح العینات، تلیھا مجموعة الخشونة قبل تعدیل العینات و متوسط للمجموعات األربع، كان ھناك فروق ذات داللة إحصائیة عالیة جدا بین متوسط .خشونةط والتي أظھرت أعلى متوس) karatالتلمیع الماسي طقم (أظھرت مجموعة .العینات تزجیج -الخشونة بعد تعدیل العینات و متوسط الخشونة بعد تلمیعأیضا كان ھناك فروق ذات داللة إحصائیة عالیة جدا في متوسط . الخشونة بعد تعدیلھا طقم التلمیع الخاص (و ) karatطقم التلمیع الماسي(وأظھر كل من ). p <0.01) (طقم التلمیع الخاص بالزركون(فرق معنوي عالي إحصائیا مع مجموعة ) karatالتلمیع الماسي بینما لم یظھر ھناك اي فرق معنوي ذات داللة إحصائیة ). p <0.001) (التزجیج(و ) ®optrafineطقم التلمیع الماسي (فرق ذات داللة إحصائیة عالیة جدا مع مجموعتي ) بالزركون ).p=0.774) (التزجیج(و ) ®optrafineطقم التلمیع الماسي (بین مجموعتي مما یوجب ضرورة تلمیع سطح , یرة في متوسط الخشونةالى أن تعدیل سطح الزركون بواسطة قرص او مثقب ماسي أدى إلى زیادة كب اشارت البحث نتائج فانفإن , و كإستنتاج أفضل نعومة لسطح الزركون مع عدم وجود اي فرق احصائي بین ) التزجیج(و ) ®optrafineطقم التلمیع الماسي (قدم كل من . الزركون أو تزجیجھ إلستعادة نعومة السطح معوضا عن الحاجة لتزجیج تركیب الزركون مع الحصول على ) ®optrafineطقم التلمیع الماسي (ركون بواسطة من الممكن ان یكون تلمیع سطح تركیب الز, و بالتالي , المجموعتین .نعومة سطح مشابھة introduction zirconia has been considered to have great potential as substitutes for traditional materials in many biomedical applications. since the end of the 1990s, the form of partially stabilized zirconia has been promoted as suitable for dental use due (1) master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor. department of conservative dentistry, college of dentistry, university of baghdad. to its enhanced biocompatibility, low radioactivity, interesting optical properties, excellent strength and superior fracture resistance as result of an inherent transformation toughening mechanism (1). dental use is trending toward fullcontour zirconia, which is a solid zirconia restoration with no porcelain overlay that promises an end of fractured esthetic porcelain on crowns and bridges especially in posterior teeth (2). j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 40 although zirconia restorations have excellent properties that meet requirements of a prosthetic material, they have several drawbacks, one of them is: irreversible wear of opposing tooth structure. the most extreme wear damage occurs when a restoration with a rough surface contacts tooth enamel or underlying dentin (3). a smooth restoration surface is important to avoid dental complications such as plaque formation, gingivitis, periodontitis, and wear of the opposing dentition. it is also important for patient comfort (4). for many years, standard clinical and laboratory techniques indicated that any adjusted restoration (dental ceramic or zirconia) should be re-glazed to restore the surface smoothness; however, reglazing is not always convenient or possible. the surface roughness of polished and glazed dental ceramic have been compared by many investigators(5-14), some of them found that the mechanical polishing have provided a better surface smoothness than glazing, while the others have found the opposite. however, it is necessary that any occlusal adjustment to the dental restoration (ceramic or zirconia) be followed with either mechanical polishing or re-glazing. materials and methods fabrication of the samples: pre-sintered full-contour zirconia block disk of (9.5x1.4 cm) was cut into small prisms using electrical cutting saw. each prism was then glued into a fitting pin that was eventually placed into a milling machine to be milled to the desired size and shape (diameter: 10 mm, thickness: 8 mm). each specimen was colored using a specific type of colouring liquid that was applied using a metal free brush. the specimens were then placed under a heat radiating infrared lamp (for 45 minutes) according to the manufacturer instructions to dry the coloured zirconia specimens that prevent damage to the furnace heating elements by acid contained in the color liquids. the specimens were then sintered in a hightemperature furnace at (1500˚c for 8 hours including cooling) according to the manufacturer instructions. after sintering, the dimensions of each specimen were (diameter: 8 mm, thickness: 6.4 mm) due to the shrinkage during sintering (about 20% shrinkage). stone block construction each specimen was then embedded in a rectangular-shaped block of stone (1.5x2.3x1.3 cm) in such a way that about 2 mm of the zirconia specimen is being outside the stone block and the long axis of the zirconia specimen being parallel to the long axis of the stone block using a surveyor. finishing of the specimens surfaces the surface of each zirconia specimen was then leveled and finished with grinding and polishing machine using rotating aluminum-oxide papers at 600 rpm. each specimen was flattened and leveled using (220, 320, 400, 600-grit papers) respectively. each paper was used for five specimens and discarded. the grinding process was done under water cooling and for 30 seconds for each paper. finally, the specimens were polished using aluminum oxide coated disks (800 then 1000-grit) mounted on a straight handpiece (5000 rpm) under water coolant. in order to have standardization, a surveyor was used: the stone block was attached to the movable table of the surveyor, while the straight handpiece was attached to the upper member of the surveyor in such a way that the long axis of the handpiece being parallel to the long axis of the zirconia sample, and the aluminum oxide disk being parallel to the surface of the specimen. the arm of the surveyor that holds the straight handpiece was moved down in such a way that the aluminum oxide disk was kept in contact with the surface of specimen for 30 seconds. each sample was polished with (800and 1000grit disk) for 30 seconds respectively. the specimens were then thoroughly washed and dried for subsequent surface roughness assessment. the surface roughness (ra) (in µm) for each specimen was then calculated using a surface roughness tester (profilometer). adjustment of the specimens' surfaces the adjustments of the surfaces of the specimens were done using a diamond disk mounted on a straight handpiece. a surveyor was used with the same standardization that was applied during finishing of the samples. the diamond disk was kept in contact with the surface of each specimen for 10 seconds, the surface roughness (ra) (in µm) for each specimen was then calculated using a surface roughness tester (profilometer). sample grouping the specimens were then randomly divided into four groups (n=10) according to the type of surface treatment that was applied, in group i, the specimens were polished with (karat diamond polishing set). in group ii, the specimens were polished with diamond polishing set for zirconia (smedent medical instrument co., shanghai, j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 41 china). in group iii, the specimens were polished with (optrafine® diamond polishing system, ivoclar vivadent, germany). while in group iv, the specimens were glazed using (akzent glaze akz 25) glazing material (vita zahnfabrik, germany). polishing and surface treatment of zirconia samples standardization of zirconia polishing and surface adjustment was controlled using straight and contra-angled handpiece mounted on a surveyor carrying the polishing burs and disks. in order to have standardization while using contraangled handpiece, the stone block was attached to the movable table of the surveyor, while the contra-angled handpiece was attached to the upper member of the surveyor in such a way that the long axis of the handpiece being perpendicular to the long axis of the zirconia sample, and the polishing surface of burs or disks being parallel to the surface of the specimen. the arm of the surveyor that holds the contra-angled handpiece was moved down in such a way that the polishing bur or disk came in contact with the surface of specimen. during polishing, the vertical arm of the surveyor was moved in estimated continuous circular movement (7 cycles for about 10 seconds) to polish each sample (15,16). for group i, karat diamond polishing set was used to polish the specimens, using diamond felt wheels impregnated with diamond polishing paste mounted on a straight handpiece at a speed of 7,000 rpm (7 cycles for 10 seconds). in group ii, zirconia polishing kit was used to polish the specimens, using (ceramic diamond grinder, rubber diamond finisher and rubber diamond polisher) respectively, mounted on a contra-angle handpiece at a speed of 10,000 rpm for both grinder and polisher, and at 15,000 rpm for finisher. each bur came into contact with the sample for 10 seconds according to the manufacturer instructions, this type of polishing set was used without the need of any polishing paste (according to manufacturer instructions). in group iii, optrafine® diamond polishing system was used to polish the specimens, using (finisher [optrafine f], polisher (optrafine p), brush with diamond polishing paste) respectively, mounted on a contra-angle handpiece at a speed of 10,000 rpm with water spray cooling for both finisher and polisher, and at a speed of 7000 rpm for brush with diamond polishing paste for high gloss polishing. each bur was used for 10 seconds according to the manufacturer’s instructions. group iv specimens were glazed using a glazing medium, glazing powder was mixed with glazing fluid to a thick consistency and applied by brush as thinly as possible to the zirconia specimens. the specimens were then sintered in high temperature furnace for about 17 minutes at 930˚c according to the manufacturer instructions. surface roughness measurement this test was performed using a surface roughness tester (profilometer) device that was used to verify the surface topography of the samples of all groups. for each specimen, three readings were recorded (first reading in vertical line, second reading in horizontal line and the third reading radial line)(16). the mean value for each sample was then calculated. results the descriptive statistics including the mean values and the standard deviation of surface roughness of the four groups (in µm) (after polishing) is shown in table (1) and figure (1). table 1: descriptive statistics including mean values and standard deviations (after polishing) groups mean sd group i (karat polishing set) 1.755 0.341 group ii (zirconia polishing kit) 1.379 0.296 group iii (optrafine® polishing system) 0.704 0.199 group iv (glazing) 0.670 0.203 figure 1: bar chart showing the mean values of surface roughness of the four groups (in µm) (before adjustment, after adjustment and after polishing). the results showed that the glazing group recorded the lowest surface roughness mean value (0.670 µm), followed by optrafine® diamond polishing system (0.704 µm), then zirconia j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 42 polishing kit (1.379 µm) and finally karat polishing set (1.755 µm) which showed the highest mean of surface roughness (ra).for all the four groups, there was a very high statistically significant difference of (ra) value before adjustment and after adjustment of samples. there was also a very high statistically significant difference in (ra) value when comparing the adjusted samples with polished and glazed ones. in order to see whether there is a statistically significant difference among the four groups after polishing; analysis of variance (anova) test was applied as shown in table (2). table 2: one-way analysis of variance (anova) test among the four groups (after polishing) anova sum of squares degree of freedom mean of squares f sig. between groups 8.459 3 2.820 39.48 0.000 (vhs) within groups 2.571 36 0.071 total 11.03 39 (vhs): very high statistically significant difference. from table (2), anova test revealed a very highly statistically significant difference among the four groups (after polishing). in order to locate the difference between groups, further analysis of the data was performed using least significant difference test (lsd), as shown in table (3). table 3: least significant difference test (lsd) between the different groups (after polishing) (ns): statistically non significant difference. (hs): statistically high significant difference. (vhs):very high statistically significant difference. from table (3), karat polishing set group showed a statistically high significant difference with zirconia polishing kit group (0.01> p ≥ 0.001). both, karat polishing set and zirconia polishing kit groups showed a very high statistically significant difference (p<0.001) with (optrafine® polishing system) and glazing groups. glazing and (optrafine® polishing system) groups showed statistically non significant difference between them (p=0.774). discussion zirconia restorations are generally considered an ideal solution for a variety of clinical applications, due to their durability, biocompatibility and natural esthetics. dental use is trending toward full-contour zirconia, which is a solid zirconia restoration with no porcelain overlay. ongoing material advancements have produced the strongest and most reliable allceramic restoration to date, making zirconia an ideal alternative solution wherever traditional metal or porcelain fused to metal (pfm) restorations might be prescribed (2). although zirconia restorations have excellent properties that meet requirements of a prosthetic material, they have several problems, one of them is: irreversible wear of opposing tooth structure under certain conditions, mainly due to high occlusal forces, which may occur because of parafunctional habits (i.e., clenching, bruxing), and premature occlusal contacts. the most extreme wear damage occurs when a restoration with a rough surface contacts tooth enamel or underlying dentin (3). a smooth restoration surface is important in three terms: function, esthetics, and biologic compatibility, that avoids dental complications such as plaque formation, gingivitis, periodontitis, and wear of the opposing dentition. it is also important for patient comfort (4). there are numerous instances in clinical practice when it is necessary to adjust a restorative surface by grinding. such adjustments break the glazed or polished surface, resulting in a rougher surface and inferior surface properties of the restoration(17). early researchers agreed that re-glazing was necessary after restoration adjustment in the clinical setting (18). many dentists therefore, prefer the surface of a restoration to be re-glazed prior to cementation (19). the introduction of intraoral polishing instruments or kits may be of great clinical importance, since they may substitute the laboratory re-glazing procedure (20, 21). bollen et al. (22) considered the critical surface roughness (ra) means for bacterial colonization of several dental materials to be 0.2 μm. surface roughness means higher than 0.2 μm are likely to j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 43 increase significantly bacterial adhesion, dental plaque maturation and acidity, which act on materials surface, thus increasing caries risk (23). an increase in surface roughness can also be responsible for alterations in light reflection that can turn material surface opaque. it has been shown that a surface is considered reflective when imperfections are well below 1 μm (24). regarding the surface roughness measurement, the profilometer appeared to be the ideal device for studying surface roughness of restorative materials. this device gives quantitative measurements that can be calculated and compared statistically. many researchers used this device to study the effect of polishing and glazing on the surface roughness of dental ceramics (6,9,11,25,26). in this study, full contour zirconia samples were prepared and sintered; they were leveled and finished in order to flatten the samples surfaces so that the profilometer would be able to measure the surface roughness and to be ascertained that all the samples having approximately the same roughness values (before adjustment) that ensure the standardization of the work and to have a standardized base line data for all the samples. this was approved by the profilometric measurement of the samples. the surfaces of the samples were then adjusted using diamond disk, due to the ability of diamond to adjust the extreme hard surface of zirconia restoration (crown or bridge); depending on moh's hardness scale, the diamond has a score of 10 which is the highest among the abrasive materials, while yttria-stabilized zirconia score ranges from 9 to 10 (27). to simulate the clinical situation, every sample was adjusted with diamond disk for 10 seconds under water cooling. within the single group (roughness between different stages) for all groups, there was a statistically very highly significant difference between (ra) value before adjustment and (ra) value after adjustment stage of samples, due to the roughening effect of the diamond disk on the samples surfaces. in group i (karat polishing kit), statistically, there was a very high significant difference between (ra) value after adjustment and (ra) value after polishing of samples, meaning that there is a significant improvement in the surface smoothness of the samples compared to that after adjustment with diamond disk, a finding that concurs with the work of camacho et al. (28) who concluded that robinson bristle brush, felt wheel and buff disk were efficient vehicles to be used in association with a diamond polishing paste in polishing of feldspathic ceramic. statistical analysis of the data within each tested group, revealed statistically very highly significant difference in (ra) roughness value between adjusted samples and after zirconia polishing and glazing, which proves the necessity of glazing and polishing of rough zirconia surfaces. this finding agrees with many previous studies (29-34, 14-16). for all groups, despite the improvement in the surface smoothness, still the zirconia samples did not retain their original surface smoothness (after leveling and finishing), so that the polished and glazed samples were smoother than post-adjusted samples and at the same time rougher than preadjusted ones, and this was approved by very high statistically significant difference between (ra) value before adjustment and (ra) after polishing. effect of polishing systems in group i, karat diamond polishing set was used to polish the zirconia samples; diamond felt wheels impregnated with diamond polishing paste were used. this group showed the highest mean value of surface roughness (ra) in comparison to the other groups of polishing and glazing. furthermore, there was a statistically very high significant difference with optrafine polishing set group and glazing group, and statistically high significant difference with zirconia polishing kit group. this means that the polishing with karat polishing set reduced the surface roughness produced the adjustment step but not to the level of smoothness as before adjustment. this could be attributed to lack of pre-polishing finishing of the zirconia samples (that was used in the other polishing groups) that would remove the minute scratches from the surface. this explanation agrees with freedman (34) who stated "it is advisable to introduce intermediate finishing and pre-polishing devices (coated disks; rubber-like, bonded abrasives) between high-speed contouring-finishing burs and diamonds before applying polishing pastes for both composite and porcelain restorative materials". in group ii, zirconia polishing kit was used for polishing of the samples. this group showed the second highest mean value of surface roughness (ra) measurement among the groups. this group showed a statistically very highly significant difference with optrafine polishing set group and glazing group, and a statistically highly significant difference with karat polishing set group. in this group, using the sequence of (grinder, rubber polisher, then a finer rubber polisher for final polishing) might contribute in j bagh college dentistry vol. 26(4), december 2014 effect of different restorative dentistry 44 some way for getting a better result than karat polishing set group, despite lacking the use of diamond paste in this system. in group iii, optrafine® diamond polishing system was used to polish the zirconia samples. this group showed lower (ra) mean value than group i and group ii (polishing groups), and slightly higher (ra) mean value than glazing group. statistically, group iii has very highly significant differences with group i and group ii, and in contrast, it had non significant difference with group iv (glazing). the smoothness of this group could be attributed to: first, the use of finishing and polishing burs in a sequential order that aided in eliminating the minute scratches found on the surface, second, the use of diamond paste in the final step. this explanation is totally in agreement with jefferies (35) who stated "a three-body abrasive wear situation exists when loose particles move in the interface between the specimen surface and the polishing application device". in group iv, the zirconia samples were glazed using a glazing medium that helped in obliterating any scratches that have been produced during surface adjustment. this group showed lower (ra) mean value than karat polishing set group and zirconia polishing kit group, and slightly lower (ra) mean value than optrafine® polishing system group. glazing group showed the smoothest surface, this group showed a statistically very high statistical significant difference with karat polishing set group and zirconia polishing kit group. this finding agrees with fuzzi et al.(17) who concluded that profilometry and sem (scanning electron microscopy) for different surface treatments of ceramic showed that glazed surface was the smoothest one. there is also an agreement with the work of al-wahadni (5) and the work of almarzok and al-azzawi(8) who found that the glazed ceramic was smoother than the polished one. there is agreement with yilmaz and ozkan(12) who concluded that the best method of restoring the surface smoothness is the glazing. there is an agreement with karayazgan et al.(11) who reported that a polished surface of feldspathic porcelain was rougher than an overglazed surface. there is also an agreement with brentel et al.(13) who found that the glazed feldspar ceramic has lower surface roughness than the polished one. on the other hand, the glazing group revealed a non significant difference with optrafine® polishing system group, a finding that is in agreement with the work of tholt et al.(7), bottino et al.(6), yuzugullu et al.(10) and wang et al.(9) who concluded that the mechanical polishing produced similar superficial roughness to that of surface glazing. the disagreement came with sabrah (14) who found a statistically significant difference between polishing full-contoured zirconia with (optrafine® polishing system) and glazing them, where glazing scored lower (ra) than polishing with (optrafine® polishing system) in his study. references 1. vagkopoulou t, koutayas so, koidis p, strub jr. zirconia in dentistry: part 1. discovering the nature of an upcoming bioceramic. eur j esthet dent 2009; 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17(3): 191-4. 29. barghi n, king cj, draughn ra. a study of porcelain surfaces as utilized in fixed prosthodontics. j prosthet dent, 1975; 34: 314-9. 30. mclean jw. the science and art of dental ceramic and their clinical use. quint pub co.; 1979; 1: 71. 31. cook pa, griswold wh, post ac. the effect of superficial colorant and glaze on the surface texture of vacuum-fired porcelain. j prosthet dent 1984; 51: 476-84. 32. cornelis hp, tousuke kc. enhancing esthetics in porcelain fused to metal through technique modification. dent clin north am 1985; 29(4): 753-9. 33. rosenstiel sf. linear firing shrinkage of metal ceramic restorations, brit dent j. 1987; 162:390-392. 34. freedman g. contemporary esthetic dentistry. st. louis: mosby inc.; 2012. p. 267-79. 35. jefferies sr. abrasive finishing and polishing in restorative dentistry: a state-of-the-art review. dent clin north am 2007; 51: 379-97. gonça4 j bagh college dentistry vol. 29(1), march 2017 white spot lesions pedodontics, orthodontics and preventive dentistry 177 white spot lesions among patients treated with fixed orthodontic appliance at different time intervals elaf abdul kareem alidan b.d.s.(1) nadia a. alrawi b.d.s, m.sc., phd.(2) abstract background:white spot lesions are common esthetic problem that compromise the success of orthodontic treatment. this study aimed to assess white spot lesions in patients with fixed orthodontic appliance at different time intervals. materials & methods:thirty two patients (24 females and 8 males) were included in this study and they underwent clinical examination for white spot lesions using enamel decalcification index at four time intervals: (2-3 weeks after appliance insertion, 2, 4 and 6 months). results:the patients were free of white spot lesions at the appliance insertion visit. the mean of white spot lesions was 2.22 which were increased significantly during six months to reach 24.59 at the end of study. there was a significant difference between the maxillary and the mandibular arches, however, there was no significant difference found between the right and the left sides in both arches. the total numbers of teeth affected by white spot lesions were 74.61% after six months of treatment. maxillary second premolar and mandibular canine were the most affected teeth; whereas the gingival area around the orthodontic brackets was the most affected area. conclusion:-orthodontic patients had a high risk for development of white spot lesions. key words:white spot lesions, orthodontic patients, fixed orthodontic appliance. (j bagh coll dentistry 2017; 29(1):177-281) introduction white spot lesion (wsl) known as iatrogenic side effect observed in patients undergoing orthodontic treatment especially those who treated with fixed appliances and associated with poor oral hygiene (1,2) or when no preventive programs were used (3). the white spot lesions had been defined as “subsurface enamel porosity that presents itself as a milky white opacity which is most commonly seen on the visible facial surfaces of teeth, but it also occurred on the occlusal and proximal surfaces'' (2,4). the white spot lesions are also defined as “the first sign of caries formation on enamel that can be recognized by naked eye. it can occur on any tooth crown surface in both primary and permanent teeth" (4,5). the appearance of white spot lesions on the enamel surface is due to a multiplicity of factors (6). conjunction of the four factors: plaque, fermentable carbohydrates, host factor (susceptible tooth surface and saliva) and sufficient time period are essential for white spot lesions to develop (6,7). white spot lesions represent enamel demineralization which is the process of dissolution of calcium and phosphate ions from dental hydroxyapatite crystal into plaque and saliva. this process is stopped by remineralization which is the process of restoring minerals from saliva to the hydroxyl apatite's latticework structure. (1) m.sc. student, department of preventive dentistry. college of dentistry. university of baghdad (2) assistant professor, department preventive dentistry, college of dentistry, university of baghdad. these processes occur simultaneously, but lesion formation occurs when the rate of demineralization exceeds the rate of remineralization (8). the most common areas that liable to demineralization are: cervical areas, areas located under the bands and enamel near cemented brackets (9). the prevalence of white spot lesion associated with orthodontic treatment showed various reports ranging from 2% to 97% (10-12). the extent of white spot lesions varied from 4.9 to 84% of the tooth surface, depending on the examination technique used (11, 13). many studies reported that white spot lesions can become visible around the orthodontic appliance within 1 month of bonding (13-15). most studies focused on development of white spot lesions at the end of orthodontic treatment, but the presence of these lesions at different times during orthodontic treatment had taken little consideration from researchers. as a result, this longitudinal study was conducted to evaluate white spot lesions occurrence among patients underwent fixed orthodontic treatment at different time intervals during orthodontic treatment. materials andmethod study sample: a longitudinal study was done in the specialist health centre for orthodontics and prosthodontics in bab al-muadham/baghdad city for 8 months period. the sample was selected from patients j bagh college dentistry vol. 29(1), march 2017 white spot lesions pedodontics, orthodontics and preventive dentistry 178 who underwent orthodontic treatment with fixed orthodontic appliances. thirty two patients (24 females, 8 males) with age range between (18-25 years) diagnosed with skeletal class i relation, class i malocclusion (mild to moderate crowding). patients with previous orthodontic treatment and/or already had white spot lesions before orthodontic treatment were excluded from study. patients were followed for six months and underwent a systematic clinical evaluation of white spot lesions related with fixed orthodontic appliance using enamel decalcification index (16) as following: 1st visit:(2-3) weeks after orthodontic appliance insertion. 2nd visit:(2 months ±2weeks) after orthodontic appliance insertion. 3rd visit:(4 months ±2weeks) after orthodontic appliance insertion. 4th visit:(6 months ±2weeks) after orthodontic appliance insertion. for standardization, each patient received a package consists of tooth paste (colgate, china) and manual two headed tooth brush (ortho technelogy, china) especially designed for orthodontic patients: one head is used for brushing around the brackets and the other head is an interdental tooth brush for brushing arch wires and between teeth. they received general oral hygiene instruction in addition to advisements about dietary habits and other oral hygiene measures. white spot lesions examination: enamel decalcification index proposed by banks and richmond in 1994 (16) was used to determine the white spot lesions around the orthodontic brackets. this index based on the facial surfaces examination that measure white spot lesions presence or absence, extent, severity and distribution of white spot lesions around orthodontic brackets. the facial surface of the tooth was divided into four areas: gingival, mesial, distal and incisal\occlusal areas around the bracket. a score was allocated for each area as followed: 0, no decalcification; 1, decalcification covering less than 50% of the area; 2, decalcification covering more than 50% of the area; 3, decalcification covering 100% of the area, or severe decalcification with cavitation. total scores per tooth were calculated by summation of the individual areas scores for each tooth, total scores ranges from 0-12. the teeth considered for examination were second premolar to second premolar in both maxillary and mandibular arches. molars were excluded from the study as they were banded obviating the visibility of white spot lesions. the teeth were visually examined on the facial surface after removing plaque with the help of instruments (hk supra\ china), removal of wires and auxiliaries' attachments and air drying. ttest was used to assess the significance of observation bias in inter and intra –calibration, general linear model repeated measures procedure affords determination of variance when same measurement is invented several times on each case or subject. the glm repeated measures procedure provides both univariate and multivariate analyses for the repeated measures data. results the results revealed that there was a wide variation of the mean value of white spot lesions at the end of study 24.59 increased more than ten times compared to the first visit after appliance insertion 2.22. additionally, the differences were statistically highly significant between orthodontic visits, table 1. table 1: mean and standard deviation values of white spot lesions during four time intervals cumulative white spot lesions mean se f sig. 1st visit 2.22 0.67 82.00 0.00 ** 2nd visit 14.84 1.88 3rd visit 19.91 2.14 4th visit 24.59 2.36 ** high significant when p˂0.01 table 2 demonstrated that white spot lesions increased with a high significant difference during time. furthermore, there was a high significant difference of white spot lesions occurrence between arches with time, but there were no significant difference in white spot lesions between the right and left sides of maxillary and mandibular arches during visits. j bagh college dentistry vol. 29(1), march 2017 white spot lesions pedodontics, orthodontics and preventive dentistry 179 table2: effect of time, arch and sides of arch on cumulative white spot lesions effect multivariate tests value f sig. time pillai's trace 0.69 91.93 0.00 h.s. time * arch pillai's trace 0.13 6.18 0.00 h.s. time * side pillai's trace 0.02 0.97 0.41 n.s. time * arch * side pillai's trace 0.02 0.74 0.53 n.s high significant at p<0.01, no significant at p˃0.05 figure1 demonstrated the cumulative white spot lesions per teeth during four time intervals. the results revealed that teeth with cumulative scores equal to zero (free of white spot lesions) were high in the first visit 88.87%. this declined during six months of treatment to reach 25.39%. additionally the data revealed that the most predominant cumulative white spot lesions scores were equal one (cs1) that reached 38.1% and cs2 that reached 17.97%. figure 1: distribution of cumulative white spot lesions per teeth during four time intervals figure2 illustrated the distribution of white spot lesions among teeth in maxillary and mandibular arches during four time intervals. the most affected teeth in maxillary arch were the second premolar 82.81% followed by the canine 81.25% and the lateral incisors 75%; while the least affected teeth were the central incisors teeth 68.75%. in mandibular arch, the most affected teeth were the canine 84.83% followed by the lateral incisor 73.44% and the second premolar 71.88%; while the least affected teeth were central incisors teeth 62.5%. figure2: the distribution of white spot lesions among teeth in the maxillary and mandibular arches during four time intervals figure 3 demonstrated the distribution of white spot lesion around the brackets in maxillary and mandibular arches during four time intervals. the gingival area was the most affected area in the maxillary and the mandibular 0% 20% 40% 60% 80% 100% cs0 cs1 cs2 cs3 cs4 cs5 cs6 cs7 cs8 cs9 cs10 cs11 cs12 4th visit 25.39 38.1 17.97 8.59 4.88 0.78 2.34 1.17 0.78 0 0 0 0 3rd visit 31.64 40.45 13.67 7.42 3.52 0.98 1.37 0.56 0.39 0 0 0 0 2nd visit 43.16 39.1 8.89 3.71 2.93 0.56 0.98 0.39 0.19 0 0 0 0 1st visit 88.87 8.59 2.34 0.2 0 0 0 0 0 0 0 0 0 0% 20% 40% 60% 80% 100% up uc uli uci lp lc lli lci 4th visit 82.81 81.25 75 68.75 71.88 84.83 73.44 62.5 3rd visit 75 75 65.63 59.38 67.19 79.69 70.31 54.69 2nd visit 65.63 62.5 57.81 45.31 57.81 67.19 56.25 42.19 1st visit 15.63 14.06 9.38 14.06 10.94 7.81 9.38 7.81 % of teeth j bagh college dentistry vol. 29(1), march 2017 white spot lesions pedodontics, orthodontics and preventive dentistry 180 arches (61.33, 66.41% respectively) during six months of study. figure 3: distribution of white spot lesions around the brackets in maxillary and mandibular arches during four time intervals [ug= gingival area in upper teeth, uo/i= occlusal or incisal area in upper teeth, um= mesial area in upper teeth, ud= dostal area in upper teeth, lg= gingival area in lower teeth, lo/i= occlusal or incisal area in lower teeth, lm= mesial area in lower teeth, ld= distal area in lower teeth] discussion statistical analysis was done by using statistical package for social sciences (spss version 18). according central limit theorem and law of large numbers which are fundamental theorems of probability that stated the distribution of sum of a large number (˃30 or 40) of independent variables will be approximately normal, regardless of the shape of data and the underlying distribution, thus many statistical procedure work according to this theorem (17). white spot lesions during orthodontic visits most of the studies that searched for white spot lesions during and after orthodontic treatment used the white spot lesion index by gorlick et al. (18), but few studies used the enamel decalcification index by banks and richmond (17) however, these studies used the latter index to compare the effect of prevented programs on white spot lesions. detecting white spot lesions during active orthodontic treatment can be challenging for the clinician. the clinical crown must be free from plaque and debris, and the presence of excess gingival tissue can make visualization of white spot lesions difficult. gingival surfaces in premolar teeth were generally covered by inflamed gingiva. this was probably due to gingival hyperplasia and inflammation that resulted from the difficulty in accessing this region and poor oral hygiene. the results obtained from the present study indicated that white spot lesions were a considerable problem during fixed orthodontic treatment. this agreed with hadler-olsen et al. (19) who reported that orthodontic patients had significant higher risk for development of white spot lesions compared to non-orthodontic patients and this attributed to the fixed appliances which served as plaque retention sites. the increase in the accumulation of dental plaque and in the absence of good oral hygiene marked demineralization occurred. white spot lesions preventive system was dependent primarily on patient compliance and oral hygiene instructions. it was very difficult to control variables such as dietary habits, oral hygiene practices, and exposure to fluorides in this clinical study. effect of treatment duration on white spot lesions: this study revealed an increase in white spot formation around orthodontic brackets when the duration of treatment increased. this result comes in agreement with abdulmawjood et al. and shrestha and shrestha (20, 21) who found that duration of treatment had a significant effect on the occurrence of white spots, but lovrov et al. (22) were unable to find association between the treatment length and the white spot lesions development. 0% 20% 40% 60% 80% 100% ug uo/i um ud lg lo/i lm ld 4th visit 61.33 45.31 23.44 17.58 66.41 25 10.16 5.86 3rd visit 53.91 33.59 16.41 10.55 60.55 23.44 7.81 4.69 2nd visit 42.56 28.52 10.16 7.03 50.78 14.45 4.29 3.52 1st visit 7.81 9.38 0.39 0 5.86 3.91 3.13 0 http://www.math.uah.edu/stat/sample/lln.html j bagh college dentistry vol. 29(1), march 2017 white spot lesions pedodontics, orthodontics and preventive dentistry 181 in the current study, white spot lesions developed as early as 2-3 weeks after the beginning of orthodontic treatment, this was in accordance to øgaard (23) who found white spot lesions became noticeable around the brackets within one month after bonding. white spot lesions in arches and sides of arch: it was found that there was a high significant difference in white spot lesions development between upper and lower jaws during the first six months of treatment and this was in accordance to abdulmawjood et al. (20). this could be due to the maxillary teeth (especially the anterior teeth) are exposed to carbohydrate more than other teeth and they less vulnerable to saliva (24), while the lower teeth are less susceptible to enamel deminerlization because of salivary flow is adequate signifying mineralization is common (6). distribution of white spot lesions among teeth: the results revealed that maxillary second premolars and mandibular canines showed the higher percentage regarding white spots formation followed by the maxillary canines and the mandibular lateral incisors, this may be due to the presence of hook at canine which made the brushing maneuver very difficult and lead to insufficient tooth brushing. this agreed with the results reported by abdulmawjood et al. (20) lovrov et al. (22) who found that the most common affected teeth were the upper premolars. however, shrestha and shrestha (21) reported that lower canines were the most affected teeth by white spot lesions. in contrast, tufekci et al. (25) found no significant differences in the distribution of white spot lesions among different types of teeth, indicating that all types of teeth were equally subjected to demineralization. on the othe hand, chapman et al. and hadler-olsen et al. (13, 19) found that the upper anterior teeth were more susceptible to white spot lesions than other teeth. this might be attributed to the use of different bracket size in the current study as the larger the bracket the short the distance between the bracket and the gingiva, especially on the lateral incisors, which makes controlling the oral hygiene difficult. moreover, lucchese and gherlone (26) found that the maxillary lateral incisor and the mandibular second premolar were the most affected teeth. the least affected teeth with white spot lesions were the central incisors in both arches. this could be due to that the patients are more conscious in keeping the esthetic zone cleaner compared to the posterior region. additionally, the lower anterior region is more protected due to presence of mandibular salivary glands and the saliva which had a cario-protective role as it regulated the exposure of tooth surface to carbohydrate substrate, plaque acidity and microbial composition of plaque (6) through salivary factors such as flow rate, ph and buffer capacity (27). this finding agreed with the finding of many studies (13, 21, 26). in this investigation and according to the distribution of white spot lesions around brackets, the gingival area developed white spot lesions more than other areas around brackets, this could be attributed to the difficulty of tooth brush accessibility gingivally to the brackets due to short clinical crown, excessive adhesives and incorrect positioning of the brackets. this result was in accordance to shrestha and shrestha (21). conclusion there is a high risk of white spot lesion formation in patient undergoing orthodontic treatment with fixed appliance. the role of oral hygienist should be knowledge and more attention should be paid for selecting patients with good compliance. references 1. øgaard b, bishara s, duschner h. enamel effects during bonding-debonding and treatment with fixed appliances. in: graber t, eliades t, athanasiou a, eds: risk management in orthodontics. experts’ guide to malpractice. quintessence publishing company, michigan, 2004: 19-46. 2. sangamesh b, amitabh k. iatrogenic effects of orthodontic treatment –review on white spot lesions. int j scieng res 2011; 2: 16. 3. jakob a, helseth st. comparison between electric toothbrush and manual toothbrush in patients with fixed orthodontic appliances. j dent 2002; 26: 655-9. 4. summitt jb, robbins jw, schwartz rs. fundamentals of operative dentistry: a contemporary approach. 3rd ed. hanover park, il: quintessence publishing company, michigan; 2006: 2–4. 5. fejerskov o, nyvad b, kidd em. clinical and histological manifestations of dental caries. in: fejerskov o, kidd em, ed. dental caries: the disease and its clinical management. blackwell munksgaard, copenhagen, denmark, 2003: 71-99. 6. jena ak. reviews in orthodontics. jaypee brothers medical publishers, new delhi, 2007: 289-301. 7. charland r, voyer r, cudzinowski l, salavail p, abelardo l. dental caries: etiology, diagnosis and treatment: still much to discover. j dent quebec 2001; 38: 409-16. 8. harris no, garcia-godoy f, nathe cn. primary preventive dentistry. 8th ed. connecticut, appleton & lange, 2013. 9. jordan c, leblance dj. influence of orthodontic appliances on oral populations of mutans streptococci. oral micro immun 2002; 17(2): 65. 10. fornell ac, skold-larsson k, hallgren a, bergstrand f, twetman s. effect of a hydrophobic tooth coating https://www.google.iq/search?tbo=p&tbm=bks&q=inauthor:%22christine+nielsen+nathe%22&source=gbs_metadata_r&cad=2 j bagh college dentistry vol. 29(1), march 2017 white spot lesions pedodontics, orthodontics and preventive dentistry 182 on gingival health, mutans streptococci, and enamel demineralization in adolescents with fixed orthodontic appliances. acta odontol scand 2002; 60: 37-41. 11. boersma jg, van der veen mh, lagerweij md, bokhout b. caries prevalence measured with qlf after treatment with fixed orthodontic appliances: influencing factors. caries res 2005; 39: 41–47. 12. richter ae, arruda ao, peters mc, sohn w. incidence of caries lesions for patients treated with comprehensive orthodontics. am j orthod dentofac orthop 2011; 139(5): 657-64. 13. chapman ja, roberts we, eckert gj, kula ks, gonzález-cabezas c. risk factors for incidence and severity of white spot lesions during treatment with fixed orthodontic appliances. am j of orthod and dentofac orthop 2010; 138: 188–194. 14. gorton j, featherstone b. in vivo inhibition of demineralization around orthodontic brackets. am j orthod dentofac orthop 2003; 123:10-14. 15. kidd em, fejerskov o. what constitutes dental caries? histopathology of carious enamel and dentin related to the action of cariogenic biofilms. j dent res 2004; 83(spec iss c):c35-c38. 16. banks p, richmond s. enamel sealants: a clinical evaluation of their value during fixed appliance therapy. eur j orthod 1994; 16:19–25. 17. elliott ac, woodward wa. statistical analysis quick reference guidebook with spss examples. 1st ed. london: sage publications, 2007. 18. gorelick l, geiger am, gwinnett aj. incidence of white spot formation after bonding and banding. am j orthoddentofacorthop 1982; 81:93-98. 19. hadler-olsen s, sandvik k, el-agroudi ma, øgaard b. incidence of caries and white spot lesions in orthodontically treated adolescents with a comprehensive caries prophylactic regimen – a prespective study. euro j orthod 2011; 12: 1-7. 20. abdulmawjood aa, ahmed h, al-saleem nr. prevalence of "white spots" around orthodontic brackets: a clinical study. al–raf dent j 2012; 12(2): 371-377. 21. shrestha s, shrestha r. prevalence of white spot lesion in nepalese patients with fixed orthodontic appliance. ortho j of nepal 2013; 3(2): 7-10. 22. lovrov s, hertrich k, hirschfelder u. enamel demineralization during fixed orthodontic treatment-incidence and correlation to various oralhygiene parameters. j orofac orthop 2007; 68: 35363. 23. øgaard b. white spot lesions during orthodontic treatment: mechanisms and fluoride preventive aspects. semin orthod 2008; 14: 183-193. 24. alaki m, locsche wj, feigal rj, dfonesca ma, welch k. prevent the transfer of streptococcus mutans from primary molar to permanent first molar by using chlorhexidine. pediater dent 2002; 24: 103-108. 25. tufekci e, dixon js, gunsolley jc, lindauer sj. prevalence of white spot lesions during orthodontic treatment with fixed appliances. angle orthod 2011; 81: 206–10. 26. lucchese a, gherlone e. prevalence of white-spot lesions before and during orthodontic treatment with fixed appliances. eur j orthod 2012; 8. 27. srivastava k, tikku t, khanna r, sachan k. risk factors and management of white spot lesions in orthodontics. j orthodsci 2013; 2(2): 43–49. الخالصة الجهاز التقويمي الثابت على فترات يضعونبيضاء في المرضى الذين ال البقعتقييم هو نجاح المعالجة التقويمية. الهدف من الدراسة تحدد منالبقع البيضاء هي مشكلة جمالية -الخلفية: زمنية مختلفة. 2-3في أربع فترات زمنية: سزوال الكل آلمينابيضاء باستخدام مؤشر ال للبقع ألسريريفحص ل، خضعوا ل(ذكور 8أنثى و 32مريضا ) 23 شملت الدراسة -:البحث مواد وطرقال أشهر. 6أشهر، 2شهور، 3، .وضع الجهازأسابيع بعد في نهاية الدراسة. كان هناك اختالف كبير بين الفك 32242كبير خالل ستة أشهر لتصل إلى معنوي والتي زادت مع فارق 3233بيضاء ال بقعال متوسطأظهرت الدراسة إن -النتائج: بعد ستة أشهر من العالج. كان ٪12267بيضاء ال بالبقع. بلغ إجمالي األسنان المتضررة من الفكينبين الجانبين اليمين واليسار في كل معنوي فرق وال يوجدالفك السفلي والعلوي المنطقة األكثر تضررا. هي تقويم األسنان قوس، وكانت منطقة اللثة حول بين األسنان الفك السفلي األكثر تضرراالناب في الفك العلوي و في نيالضاحك الثا بيضاء.ال لحدوث البقعمخاطر عالية في مرضى تقويم األسنان ان-االستنتاج: .تقويم األسنان الثابتجهاز بيضاء، مرضى تقويم األسنان، ال البقع-الكلمات الرئيسية: http://www.ncbi.nlm.nih.gov/pubmed/?term=srivastava%20k%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=tikku%20t%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=khanna%20r%5bauth%5d http://www.ncbi.nlm.nih.gov/pubmed/?term=sachan%20k%5bauth%5d 2. hikmat f.doc j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 5 effect of surface treatments and thermocycling on shear bond strength of various artificial teeth with different denture base materials hikmat j. aljudy, b.d.s., m.sc., ph.d. (1) ali n. a. hussein, b.d.s., m.sc. (2) ihab n. safi, b.d.s., m.sc. (2) abstract background: separation and deboning of artificial teeth from denture bases present a major clinical and labortory problem which affect both the patient and the dentist. the optimal bond strength of artificial teeth with denture base reinforced with nanofillers and flexible denture bases and the effect of thermo cycling should be evaluated. this study was conducted to evaluate and compare the shear bond strength of artificial teeth (acrylic and porcelain) with denture bases reinforced by 5% zirconium oxide nanofillers and flexible bases under the effect of different surface treatments and thermo cycling and comparing the results with conventional water bath cured denture bases. material and methods: two types of artificial teeth; acrylic and porcelain were used and prepared for this study. five specimens of each tooth type were processed to each denture base materials after the application of different surface treatments; these teeth were bonded to heat polymerized, nano composite resin and flexible denture bases. specimens were thermo cycled and tested for bond strength until fracture with an instron universal testing machine. data were analyzed with analysis of variance and student t-test. photomicrographic examinations were used to identify adhesive and cohesive failures within debonded specimens. results: the mean force required to fracture the specimens were obviously larger for nanocomposite specimens compared with the heat cured and flexible specimens. the most common failure was cohesive within the tooth or the denture base. with each base material, the artificial teeth which were treated with thinner exhibited highest shear bond strength. thermocycling had deleterious effect on the flexible denture base specimens. in general, nanocomposite and heat cured groups failed cohesively within the artificial tooth. while the valplastic groups failed adhesively at the tooth denture base interface. conclusions: within the limitations of this study, the type of denture base materials and surface treatments of the tooth selected for use may influence the shear bond strength of the tooth to the base. selection of more compatible combinations of base and artificial teeth may reduce the number of prosthesis fractures and resultant repairs. key words: acrylic teeth, porcelain teeth, nano composite denture base, thermo cycling, flexible denture, thinner, hydrofluoric acid, shear bond strength, photo-microscope. (j bagh coll dentistry 2013; 25(1):5-13). introduction one of the benefits of using acrylic teeth instead of porcelain teeth is their ability to chemically bonding to denture base.(1) two processes affect the achievement of such a chemical bond. first, the polymerizing denture base must come into intimate contact with the denture tooth. second, the polymer network of the denture base must react chemically with the acrylic tooth polymer to form an interwoven polymer network. equalized solubility or compatibility of the two polymers is essential for the interwoven polymer and thus for the strength of the bond. (2) foreign materials which interfere with the contact between the polymerizing denture base and the tooth, thereby adversely affecting the bond strength. (1) lecturer, university of baghdad, college of dentistry, prosthodontics department. (2) assistant lecturer, university of baghdad , college of dentistry, prosthodontics department. presence of tinfoil substitute used as a mold separating agent on the artificial tooth significantly lowers the tooth denture base bond. (3) chemical or mechanical preparation of the artificial teeth ridge lap before the processing had multiple effects on the bond strength. (4) mechanical retention is required when acrylic resin is bonded with acrylic teeth. the teeth with vertical grooves showed significantly superior bond strength in all tooth types and resin combinations and that was due to the increase in the surface area.(5) porcelain teeth that were air abraded with aluminum oxide particles showed significantly lower bond strength after thermo cycling.(6) solvent wetting of the teeth enhance the bond between teeth and denture bases. on academic basis, the monomer softened the surface of the teeth and diffuses into the tooth polymer. on polymerization, an interdigitation network of polymer units bonds the denture base to the tooth. (7) the absence of the influence of the solvent on the j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 6 bond strength was related to the high degree of cross linking of the acrylic teeth. cross linking were done to improve the properties of the tooth such as fracture, abrasion and staining resistance. but, on the basis of bonding strength the cross linked teeth don’t provide good bonding strength. (8) strongest bond was obtained between heat cured resin and plastic teeth. the bond between flexible resin and both types of teeth were entirely relies on the mechanical retention to retain the teeth, so that if there were no room to place retention holes in the teeth, they can be displaced over time. (9) on the other hand, heat cured resin reinforced with nanofillers had the highest interfacial shear bond strength between the resin matrix and nanofillers when compared with the conventional resin matrix. this super molecular bonding which fond to cover or shield the nanofillers and creates thick interfaces that enhances the bond between the resin molecules. (10) thermo cycling is essential in studies of microleakage because it exposes the restoration to simulated situations that normally stress the marginal seal. this is particularly important when the coefficient of thermal expansion of the restorative material is different from that of tooth structure. thermo cycling was used to more closely simulate the oral conditions. the range of temperature used had an upper limit being 45-60 c° and lower limit 4-15c°, which were based on changes in temperature that are within normal extremes in the oral cavity and induce an opening between the tooth and restoration. (11) this theoretically allowed for repeated expansion and contraction of the tooth and denture base components thereby stressing the bond. the secondary benefit of thermo cycling was hydration of the specimens, which further simulated the clinical conditions. (12) this study was conducted to evaluate the shear bond strength of artificial teeth (acrylic and porcelain) bonded to the following denture bases: conventional water bath, resin reinforced with 5% zro2 nanofillers and flexible (nylon) denture bases after application of different surface treatment materials: thinner (turpentine) for acrylic teeth and acid etching (hydrofluoric acid) for porcelain teeth and the effect of thermo cycling (aging) on that bond. materials and method a total of 120 specimens of maxillary central incisors were selected. for each denture base type; 60 acrylic teeth (florident, china) and 60 porcelain teeth (ivoclar, vivadent) were waxed onto the beveled surface of a rectangular wax block according to the japanese standard for artificial teeth (jist 6506, 1989) as shown in figure 1. (a) (b) figure 1: a; the specimen configuration, b; the specimen’s dimensions. the slope of the beveled surface aligned each artificial tooth long axis 45 degrees to the base of the wax block as shown in figure 2. figure 2: acrylic and porcelain teeth attached to waxed blocks. surface treatments the ridge lap surfaces of the artificial teeth were treated with chemical solvent thinner (dynacoat thinner standard, product of netherlands) for acrylic teeth and hydrofluoric acid (thomas baker india hf analyzer) for porcelain teeth by using cotton bullets for 3 minutes. photomicroscope pictures were taken to the surface of the teeth prior to and after the application of surface treatments and also after failures by using photomicroscope (h.b.h.olympus, japan). mould preparation for the test specimens: the waxed patterns were coated with a separating medium and allowed to dry. a 120 gm dental stone type iii (elite model, italy) slurry was poured into the lower half of the flask, then the j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 7 a. b. c. waxed patterns were inserted into the stone slurry to one-half of their depth and left to set. after the stone was set, it was coated with separating medium and allowed to dry. for the flexible specimens wax sprues were prepared; major sprues with 6-8 mm in diameter and minor sprues of 2-4 mm in diameter and attached to selected areas from one side of the waxed patterns.(13) then the upper portion of the metal flask was positioned on the top of the lower portion and filled with 300 gm stone. vibration was done to get rid of the air bubbles. stone was allowed to harden before the metal flask was opened. wax elimination was performed using boiling water then metal flask was opened, the teeth were attached to the upper half of the flask while mold halos were left to the lower half. the mould was then carefully cleaned with detergent and washed thoroughly with boiling water to make sure all residues were eliminated. the flasks were allowed for cooling at room temperature as shown in figure 3. figure 3: the upper and lower halves of the flask after wax elimination and flask opening preparation of denture bases: a. acrylic reinforced with 5% silanated zro2 nanofillers: silanation of (zro2) fillers: the introduction of reactive groups onto fillers surface was achieved by reaction of the 3trimethoxysilylpropylmethacrylate, tmspm, (sigma aldrich, germany) with zirconium oxide nano-fillers (sigma-aldrich germany). addition procedure was done as follows: 30g of nano-fillers and 200 ml pure toluene solvent were placed into a glass flask then sonicated at ambient temperature of (37cº) for 20min. after that, the nano-filler and toluene were placed into a flask equipped with a magnetic stirrer (labinco, bv model l-81) at room temperature. then, 1.5 gm of silane (5% wt to nano-filler) was added drop wisely by sterile syringe under rapid stirrer. the flask was covered by para-film and the slurry was left standing in the flask for 2 days. the toluene solvent was removed by rotary evaporator (re 510, yamato, japan) under vacuum at 60°c and rotation of 150 rpm for 30 min. then the silenated nano-filler was dried in vacuum oven (gallen bamp, england) at 60cº for 20 hours. after that nano filler were stored at room temperature before use. (14) proportioning and mixing of the acrylic: addition of nano-fillers: the incorporation of modified zirconium oxide nano-filler powder to monomer was done by 5% weight which is equal to 0.600 g silanated zro2. an electronic balance (sartorius bp 30155, germany) with accuracy of (0.0001gm) was used. after the addition of zro2 nano-filler to 6 ml monomer, the fillers were well dispersed in the monomer by ultra sonication, using a probe sonication apparatus (soniprep-150, england) at 120 w, 60 khz for 3 minutes to break them into individual nano-crystals (15) as shown in the figure 4. figure 4: nano-fillers were well dispersed in the monomer by ultrasonication as shown in a: before, b: during and c: after sonication. the suspension of the monomer with zro2 nano-filler was immediately mixed with 11.400 g of acrylic powder (spofa dental czechoslovakia) to reduce the possibility of particle aggregation and phase separation. the proportion for mixing of acrylic resin was (12 gm: 6 ml) p/l ratio. all materials were mixed and manipulated according to manufacturer's instructions. the mixing was carried out at once, in a clean and dry mixing vessel and mixed by a clean wax knife for 30 second. the mixture was then covered and left to stand until a dough stage was reached and then placed inside the mould. (15) the flasks were immersed in water bath at 73cº for 90 minutes, raising the temperature to 100ºc and maintaining the boiling for 30 minute. once the polymerization cycle was completed, the flasks were allowed to slow cooling in a water bath at room temperature before deflasking. (15) j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 8 bflexible (nylon) denture base material the procedure started with the heating cylinder inserted into the slot present inside the electrical furnace and the furnace was allowed to warm up till it reaches the preset heating which was 287°c, then the heating cylinder removed from the furnace. the flexible cartridge (flexible nylon granules valplast international corporation, usa) metal disc and the short solid metal cylinder inserted into the heating cylinder and left inside the furnace for 11 minutes to allow the granules inside the cartridge to melt. during that time the flask, which previously preheated inside an oven set at 65°c for 30 minutes, removed from the oven and placed inside the injection unit (plastic injection system, kcx-09b, china) in horizontal correct position with the aid of the projection present at the base of the injection unit. in this position the injection opening was at the top surface of the flask (16) as shown in figure 5. figure 5: the configuration of the injection system. the material was injected inside the flask by the use of the manual injection unit; the handle of the injection unit was tightened until both springs on the top side of the unit were closed to give a pressure of 5 bars. after 5 minutes the pressure was released and the flask is removed from the injection unit and allowed for cooling at room temperature. then the flask was opened and the specimens were removed from the mold. (16) finishing, polishing and conditioning of the specimens the sprues were cut off from the specimens with a cut off disc at a low pressure with continuous water cooling to avoid overheating the material. the edge of the specimen was trimmed with a grinding wheel (1500 rpm). all the specimens were hand finished using finer grades of silicon carbide paper (grades 120 to 500) with continuous water cooling. overheating the specimens was avoided during finishing. the specimens were smoothed prior to polishing with the smooth blue rubber wheels on the mandrills. for polishing, tripoli compound with a dry rag wheel was used to produce smoothness. oil residues from the tripoli compound were removed by washing with soap and water (17). all specimens were stored at 37c° for 7 days in distilled water before the shear test. then half of the specimens were tested by using instron machine (instron corporation, canton mass). the other half of the specimens were thermo cycled by thermocycling device (haackt, germany) between 5c° and 55c° in 60-second cycle for 3 days which means approximately 1000 cycles, and then they were tested immediately in the tenth day by the same machine. shear load was applied at 45 degrees from the long axis of each denture tooth on the palatal surface at a cross head speed of 1.5 mm/min until fracture as illustrated in figure 6. figure 6: specimen attached to metal fixture fixed on the instron machine. for all specimens, the interface where failure occurred was inspected. the failure was classified as either adhesive or cohesive in nature as in figure 6. figure 7: fractured specimens under visual examination. specimens were loaded until fracture and the load of fracture was recorded from the instron graph reader in newton. (18) the shear bond strength were calculated based on the force (f) in (n) at fracture and adhesive surface area (s) in (mm2) and converted to (mpa). where b.s = f / s and b.s = j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 9 bond strength (n/mm2) or (mpa), s= (π / 4) × d2; µ=22/7 or 3.14. d (diameter) = 5mm, s = 19.64 mm2. (19) the data were analyzed statistically using 3 way analysis of variance (anova). the variables were surface treatments, denture base resin and thermo cycling. student t-test for comparison and failure percentage was also applied. results results of shear bond strength means in mpa were given in table1 for acrylic teeth and table 2 for porcelain teeth bonded to heat, flexible and nano-composite denture bases. the three way anova revealed high significant difference in the bond strengths among the surface treatments, denture base resin and thermo cycling (p<0.001). there were also high significant differences in the artificial teeth surface treatments and denture base interactions (p<0.001) as shown in table 3. effect of surface treatments t-test of surface treatments of artificial teeth showed that both the acrylic and porcelain teeth possessed higher bond strength than the control denture teeth (p<0.001) except for the flexible denture base. the application of thinner for acrylic teeth and hydrofluoric acid for porcelain teeth significantly improved the bond strength for all types of denture bases before and after thermo cycling as shown in tables 4 and 5. effect of type of denture base materials t-test for comparison showed that the nano composite and heat cured denture base generally possessed significantly higher bond strength than the flexible cured denture base except for groups bonded to porcelain teeth were data revealed no significant differences as shown in tables 6,7,8,9. effect of thermo cycling t-test of the comparison showed that the thermo cycling had no significant effects on the bond of acrylic teeth to heat cured denture base especially in the control group (p>0.05). while it possessed high significant effect on the shear bond strength of the flexible denture base bonded to both acrylic and porcelain teeth (p<0.001). on the other hand, results showed that thermo cycling had no significant effects on the bond of acrylic and porcelain teeth bonded to nanocomposite denture base (p>0.05) as shown in tables 10,11,12 and figures 7 and 8. the photo microscopic examination of the un treated acrylic and porcelain teeth showed a homogenous surface devoid of irregularities. the treatment thinner creates pores and channels while with hydrofluoric acid porcelain teeth revealed loss of surface glaze. the cohesive failure mode of the artificial teeth bonded to denture bases were shown in figures 9. discussion all the data from the experiment were separated according to the artificial teeth type, the denture base type and before and after thermo cycling. effect of surface treatments the use of thinner for acrylic teeth and hydrofluoric acid for porcelain teeth achieving high shear bond strength. thinner is a strong solvent composed from multiple solvents. dissolve away the micro debris and smooth out the surface and produced sponge like structure thereby increasing the number of active sites which facilitates the swelling of the denture tooth polymers and there by enhances the diffusion of the polymerizable materials, notably mma, from the denture base resin. the strength of the bond depends on the degree of penetration of the solvent and the strength of the interwoven polymer network formed thereafter. (20) hydrofluoric acid or other acids creates retentive channels which optimize the micromechanical bond between the ceramic and the resin. (21, 27) effect of denture bases type flexible resin does not appear to be capable of diffusing effectively into the tooth surface to ensure a satisfactory bond due to poor wetability as a result of higher viscosity and lack of polymerization reaction because these materials being heat pressed in to a denture form.(22) also, the mismatch of polymerization reaction between artificial tooth and denture base when flexible is used does not provide the same free monomer transfer as is found in heat cured resins.(23) in addition, the higher temperature of polymerization of heat cured resin leads to higher and faster diffusion rates of the free monomer to the swelled beads of acrylic teeth leading to a stronger shear bonding strength.(24) also, the long curing cycle of heat cured acrylic resin compared with the short curing cycle of flexible resin lead to produce a material with high molecular weight and strong bonds between the polymer chains.(24) on the other hand, nanocomposite denture base had the highest interfacial shear bond strength between the resin j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 10 matrix and nanofillers when compared with the conventional resin matrix. this super molecular bonding which was found to cover or shield the nanofillers and creates thick interfaces that enhances the bond between the resin molecules and creates higher molecular weight polymers. (10) effect of thermo cycling acrylic teeth and the acrylic resin denture base have nearly the same coefficient of thermal expansion (80-81 x 106 /c°) therefore, this similarity reduced the chance for the creation of thermal stress, so the bond strength was not affected by such thermal fluctuation. (25) also, the smooth surface (untreated) facilitated a closer adaptation of denture base to the tooth surface during adaptation of resin to the tooth ridge lap during packing, thus minimizing voids creation(25). solvent treatments (thinner) of the acrylic teeth leads to the creation of channels and pores and also voids formed during solvent evaporation as revealed by microscopic examination which prevents a close adaptation of the tooth to the denture base resin during packing. (20) moreover, since thermo cycling cause hydration of the specimens, so the material absorbed water and this had a damaging effect on the bonding. the water may peculate directly into the bond site, accumulates in the voids at the interface leading to swelling and consequently stresses build up at the denture base interface. (12) flexible resin was possibly more susceptible to partial cracks during finishing and polishing procedures on the lathe machine and then the additional stress of thermo cycling may had propagated the cracks to total fractures seen in most of flexible specimens. (22) on the other hand nanocomposite denture bases were no affected by thermo cycling due to the shielding effects on the silanated nonofillers. (10) thermo cycling had no effect on bond strength of porcelain teeth to nonocomposite denture base suggests that porcelain teeth relied primarily on the metal pins for retention in the denture base. the adhesion of the denture base to porcelain surface probably contributed so negligibly to the bond strength that further thermal assault made no difference in the bond strength. (26) the differences in the coefficients of thermal expansion between porcelain teeth and denture base were higher than that between acrylic teeth and denture base. it has been estimated that the coefficient of the denture base resin and aluminous porcelain were approximately (80x106/c°) and (6.6 x106/c°) respectively. significant thermal stresses were anticipated to be induced at the porcelain teeth denture base junction during thermo cycling. therefore, repeated expansion and contraction at the bonding sites play vital role in lowering the bond strength of porcelain teeth to denture base. (25) references 1. zukerman gk. a reliable method for securing anterior denture teeth in denture bases. j prosthet dent 2003; 89: 603-7. 2. vallittu pk and ruyter ie. swelling of pmma resin at the repair joint. int j prosthodont 1997; 10 (3): 254-58. 3. cunningham jl and benington ic. a survey of the prebonding preparation of denture teeth and the efficiency for de-waxing methods. j prosthet dent 1997; 25(2): 125-128. 4. takahashi y and chai j. assessment of shear bond strength between three denture reline materials and a denture base acrylic resin. int j prosthodont 2001; 14: 531-5. 5. nishigawa g, maruo y, okamoto m et al. effect of adhesive primer developed exclusively for heat curing resin on adhesive strength between plastic artificial tooth and acrylic denture base resin . dent mater j 2006; 25:75-80. 6. el–sheikh mm and powers jm. tensile bond strength of porcelain teeth to denture resin before and after aging. int j prosthodont 1998; 11(1): 16-20. 7. rached rn; del-bel cury aa. heat cured resin repaired with microwave cured one: bond strength and surface texture j oral rehabil 2001; 28: 370-375. 8. consani rlx, mesquita mf, zampieri mh, mendeswb, consani s. effect of simulated disinfection by microwave energy on the impact strength of the tooth/acrylic resin adhesion. open dent j 2008; 2:13-7. 9. chung kh, chung cy, chung cy, chan dcn. effect of preprocessing surface treatments of acrylic teeth and bonding to the denture base. j oral rehabil. 2008; 35: 268-75. (ivsl) 10. saavedra g, valandro lf, leite fpp etal. bond strength of acrylic teeth to denture base resin after various surface conditioning methods before and after thermocycling int j prosthet 2007; 20: 199-201. 11. adeyemi aa, lyons mf, cameron da. the acrylic tooth-denture base bond: effect of mechanical preparation and surface treatment. eur j prosthodont res dent 2007; 15: 108-14. 12. schneider ri; curtis er and clancy jms. tensile bond strength of acrylic resin denture teeth to a microwave or heat processed denture base. j prosthet dent 2002; 88(2): 145-150. 13. arima t, nikawa h, murata h, hamada t, harsini. composition and effect of denture base resin surface primer for reline acrylic resin. j prosthet dent 1996; 75(4):457-462. 14. ayad nm, badawi mf, fatah aa .effect of reinforcement of high impact acrylic resin with microzirconia on some physical and mechanical properties.rev clin pesq odontol 2008; 4(3):145-151. 15. mohammed a, solhi l, nodehi a, mirabedini sa, akbari k, babanzadeh s .pmma-grafted nano clay as j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 11 novel filler for dental adhesives. dent mater 2009; 25:339-47. 16. rizgar ma. the effect of addition of radiopaque materials on some mechanical and physical properties of flexible denture. ph.d. thesis. 2009. p.34. 17. al–ani mj. the effect of different surface treatment on the transverse strength and deflection of repaired acrylic specimens. m.sc. thesis. college of dentistry, university of baghdad 2000. p: 9 18. theane hp, cuew cl, goh ki. shear bond strength of denture teeth to base: a comparative study. quintessence. 1996; 27(6): 425-428. 19. vergani ce, machaclo al, giampaolo et, pavarina ac. effect of surface treatment on bond strength between composite resin and acrylic resin denture teeth. int j prosthodontic 2000: 13(5): 383-386. 20. delbert trew. coat oil was useful all-purpose home remedy. texas escapes. blue prints for travel, llc 2007; ch4; p: 65. 21. anusavice kj. phillip's science of dental materials. 10th ed. philadelphia: w.b, saunders co; 2008, pp. 211, 220, 235, 237-271. 22. negrutiu m, sinescu c, romanu m, pop d, laktos s. thermoplastic resins for flexible framework removable partial dentures. temisoara med j.2005; 55: 295-299. 23. consani rlx, mesquita mf, manesco im, corrersobrinho l. sinhoreti mac, effect of microwave treatment on the shear bond strength of the denture tooth/acrylic resin. j adhesion 2008; 84:937-48. 24. cunningham jl. shear bond strength of resin teeth to heat cured and light cured denture base resin. j oral rehabl 2000; 27: 312-316. (ivsl) 25. garcia rcmr, leon blt, oliveira vmb, cury aadb. effect of denture cleanser on weight, surface roughness and tensile bond strength of two resilient denture liners. j prosthet dent 2003; 89(5): 489-494. 26. chai j, takahashi y, takahashi t, habu t. bonding durability of conventional resinous teeth and highly cross-linked denture teeth to a pour type denture base resin. int j prosthet 2000; 13(2): 112-116. 27. meng gk, chung kh, fletcher-stark ml, zhang h. effect of surface treatments and cyclic loading on the bond strength of acrylic resin denture teeth with autopolymerized repair acrylic resin. j prosthetic dent 2010; 103(4): 245-252. (ivsl) table 1: descriptive analysis of shear bond strength in (mpa) for acrylic teeth bonded to heat, flexible and nanocomposite denture bases table 2: descriptive analysis of shear bond strength in (mpa) for porcelain teeth bonded to heat, flexible and nanocomposite denture bases control thinner heat cured before thermocycling after thermocycling before thermocycling after thermocycling mean 2.342 2.308 9.623 9.673 sd 0.6 0.595 0.509 0.586 flexible mean 0.323 0.187 0.255 0.136 sd 0.078 0.059 0.051 0.029 nanocomposite mean 2.393 2.308 9.759 9.114 sd 0.051 0.078 0.433 0.051 control hydrofluoric acid heat cured before thermocycling after thermocycling before thermocycling after thermocycling mean 3.7 3.632 4.26 3.462 sd 0.118 0.147 0.176 0.051 flexible mean 3.802 2.342 4.209 3.004 sd 0.51 0.539 0.579 0.222 nanocomposite mean 3.887 3.717 4.43 3.955 sd 0.128 0.051 0.184 0.339 j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 12 table 3: anova table of differences of groups and between groups for acrylic and porcelain teeth bonded to heat, flexible and nanocomposite denture bases table 4: t-test between control group and surface treatments groups for all denture bases bonded to acrylic teeth before and after thermo cycling table 5: t-test between control group and surface treatments groups for all denture bases bonded to porcelain teeth before and after thermocycling heat cured denture base control & hydrofluoric acid t test p value significance before thermocycling 4.27 0.051 ns after thermocycling 1.899 0.0198 ns flexible denture base control & hydrofluoric acid t test p value significance before thermocycling 0.544 0.595 ns after thermocycling 0.516 0.269 ns nanocomposite denture base control & hydrofluoric acid t test p value significance before thermocycling 12.32 0.007 hs after thermocycling 1.359 0.307 ns table 6: t-test between heat, flexible and nano composite denture bases bonded to acrylic teeth before and after thermocycling in the control group experimental groups f-test p-value sig. heat, flexible and nano denture bases bonded with acrylic teeth control group 32.99 0.003 s heat, flexible and nano denture bases bonded with acrylic teeth thinner group 61.32 0.001 hs heat, flexible and nano denture bases bonded with porcelain teeth control group 23.9 0.006 hs heat, flexible and nano denture bases bonded with porcelain teeth hydrofluoric acid group 9.763 0.029 s heat cured denture base control & thinner t test p value significance before thermocycling 14.07 0.003 hs after thermocycling 11.315 0.008 hs flexible denture base control & thinner t test p value significance before thermocycling 0.896 0.465 ns after thermocycling 1.009 0.423 ns nanocomposite denture base control & thinner t test p value significance before thermocycling 26.96 0.001 hs after thermocycling 113.21 0.001 hs control before thermocycling control after thermocycling denture bases t test p value significance t test p value significance heat and flexible denture bases 5.47 0.032 s 5.75 0.029 s heat and nano denture bases 0.134 0.906 ns 0.001 11.00 ns flexible and nano denture bases 56.36 0.001 hs 127.4 0.001 hs j bagh college dentistry vol. 25(1), march 2013 effect of surface treatments restorative dentistry 13 table 7: t-test between heat, flexible and nano composite denture bases bonded to acrylic teeth before and after thermocycling in the thinner treatment group table 8: t-test between heat, flexible and nano composite denture bases bonded to porcelain teeth before and after thermocycling in the control group table 9: t-test between heat, flexible and nano composite denture bases bonded to porcelain teeth before and after thermocycling in the hydrofluoric acid treatment group hydrofluoric acid before thermocycling hydrofluoric acid after thermocycling denture bases t test p value significance t test p value significance heat and flexible denture bases 0.130 0.908 ns 4.225 0.049 s heat and nano denture bases 0.986 0.908 ns 2.442 0.135 ns flexible and nano denture bases 0.564 0.629 ns 3.166 0.049 s a b thinner before thermocycling thinner after thermocycling denture bases t test p value significance t test p value significance heat and flexible denture bases 28.71 0.001 hs 24.25 0.002 hs heat and nano denture bases 0.274 0.81 ns 1.229 0.344 ns flexible and nano denture bases 41.9 0.001 hs 26.93 0.001 hs control before thermocycling control after thermocycling denture bases t test p value significance t test p value significance heat and flexible denture bases 0.432 0.708 ns 4.935 0.039 s heat and nano denture bases 4.106 0.048 s 1.306 0.305 ns flexible and nano denture bases 0.229 0.793 ns 4.863 0.041 s figure 7: bar chart of the mean value of shear bond strength in (mpa) for all types of denture bases bonded to acrylic teeth before and after thermocycling. figure 8: bar chart of the mean value of shear bond strength in (mpa) for all types of denture bases bonded to porcelain teeth before and after thermocycling. figure 9: a, cohesive failure mode showing acrylic teeth remnants on base side. b. cohesive failure mode showing porcelain remnants on base side. j bagh college dentistry vol. 28(4), december 2016 detection of granulocyte oral and maxillofacial surgery and periodontics 122 detection of granulocyte chemotactic protein 2 in serum of periodontitis patients saja gh. hussien, b.d.s. (a) basima gh. ali, b.d.s., m.sc. (b) abstract background: chronic periodontitis defined as “an infectious inflammatory disease within supporting tissues of the teeth, progressive attachment loss and bone loss". aggressive periodontitis is rare which in most cases manifest themselves clinically during youth. it characterized by rapid rate of disease progression .pro-inflammatory chemokines organized inflammatory responses. granulocyte chemotactic protein 2 is involved in neutrophil gathering and movement. the purpose of the study is to detect serum of granulocyte chemotactic protein 2 and correlate to periodontal condition in patients with chronic periodontitis, aggressive periodontitis and healthy control subjects and measurement the count of neutrophils for the studied groups. subjects and methods: eighty four male and female were enrolled in this study .they were divided into three groups (18) patients with aggressive periodontitis with age range (20-45) years, (33) chronic periodontitis patients and (33) healthy control with an age range (30-50). clinical periodontal parameters were recorded for each group. the concentration of granulocyte chemotactic protein2 in serum was quantified by a high-sensitivity enzyme linked immunosorbent assay. blood neutrophils count were detect for five subjects from each group using light microscope result: anova analysis revealed high significant differences in granulocyte chemotactic protein 2 means between aggressive, chronic and controls. neutrophils count in aggressive periodontitis is higher than chronic and controls .no significant difference in neutrophils count between aggressive and chronic periodontitis, while significant difference when correlate them with controls conclusion the concentration of granulocyte chemotactic protein 2 increased with the increase in severity of periodontitis. higher neutrophils count was found in aggressive periodontitis than chronic and controls. as higher granulocyte chemotactic protein 2 that chemoattract more neutrophils recruitment to the site of inflammation keywords: granulocyte chemotactic protein 2, aggressive periodontitis, chronic periodontitis, neutrophils. (j bagh coll dentistry 2016; 28(4):122-127) introduction periodontitis can be defined as a range of clinical entities that are characterized by immunological destruction of the supporting tooth structures in response to chronic challenge by specific bacteria in sub gingival biofilm (1). periodontitis presents in two forms chronic and aggressive, with the possibility for both to involve a localized area or generalized involvement. this form of periodontal disease undergo defect in their immune response to dental biofilms .one of these immune defects is related to activity of neutrophils which is form the main component of human innate immune system first line defense that kill pathogens and lead to tissue healing by promoting inflammatory resolution (2). chemokines are produced in response to bacterial components. chemokines are a class of chemotactic cytokines that stimulate recruitment of relatively specific leukocyte subset (3). granulocyte chemotactic protein 2 (gcp-2) of 6kda (75 amino acids) is a chemokine cxc as a neutrophil chemoattractant. it produced by stimulated human osteosarcoma cells (mg-63) (4). (a) master student, department of periodontics, college of dentistry, university of baghdad. (b) professor, department of periodontics, college of dentistry, university of baghdad. materials and methods sample selection the subjects enrolled in the present study composed of (84) subjects. they were divided into three main groups (33) patients have cp, (18) ag p, and (33) subject wit clinically healthy periodontium as control. the age ranged from (30-50) years for chronic and control and (20-45) years for aggressive group. all clinical parameters pi (5), gi (6), bop (7), ppd (8) and cal were recorded for each group. under a strict aseptic condition a 5ml venous blood was withdrawn from each subject. blood sample was collected into edta tubes .after centrifugation for 10 minutes at 4000 rpm to separate serum from blood and collected in eppendrof and kept in the deep freeze at 20 ˚c till used. results were calculated using the standard curves created in each assay. a concentration of the granulocyte chemotactic protein 2 was corrected for serum defined as (pg/ml). for measuring neutrophils count a 3ml of venous blood was withdrawn from 5 subjects of each group. blood sample was collected into edta tubes. the count done (cells/ μl.) using light microscope. j bagh college dentistry vol. 28(4), december 2016 detection of granulocyte oral and maxillofacial surgery and periodontics 123 assay procedure/ human serum gcp2 elisa kit, china equilibrate all materials and prepared reagents to room temperature (18 25°c) prior to use. it is recommended to assay all standards, controls and samples in duplicate 1. add 100 μl of each standard and sample into appropriate wells. cover well and incubate for 2.5 hours at room temperature or over night at 4°c with gentle shaking . 2. discard the solution and wash 4 times with 1x wash solution. by filling each well wash with wash buffer solution (300 ml) using a multichannel pipette or autowasher. 3. add 100 μl of 1x prepared biotinylated antibody to each well. incubate for hour at room temperature with gentle shaking 4. discard the solution. repeat the wash as in step2 5. add 100 μl of tmb one-step substrate reagent to each well. incubate for 30 minute at room temperature in the dark with gentle shaking. 6. add 50 μl of stop solution to each well. read at 450 nm immediately (figure 1). figure1: elisa (human-germany) procedure of neutrophils count after 3ml blood collection into edta tubes , put blood into slide and make a smear .let it to dry for 10 minutes then lishmans stain add to it and let to dry for ( 1.5 ) minute, after that diluted with distilled water for 6 minutes then leave it for study under light microscope. statistical analyses all patients' data entered using computerized statistical software; statistical package for social sciences (spss) version 17 was used. adescriptive statistics presented as (mean ± standard deviation), bfrequencies and percentages. multiple contingency tables conducted and appropriate statistical tests performed, c chi square test was used to compare frequencies and percentage between any two groups dfishers exact test was used if more than 20% expected variables were less than 5. p value of more than 0.05 was regarded as statistically insignificant as follows: p>0.05 ns non-significant 0.05≥p>0.01 * significant 0.01≥p>0.001 ** highly significant results descriptive analysis the result of this study based on the analysis for the sample of (84) male and female patients, (18) with aggressive periodontitis, (33) with chronic periodontitis and (33) subjects with clinically healthy periodontium as control .the age of the patients ranged between (20-40) years for aggressive periodontitis, (30-50) years for cp group and control group. the mean age of the participants was (37±8) years. the percent of participant male was 53.6 % and 46.4 % female. as shown in table (1). aggressive periodontitis patients were significantly associated with younger ages and chronic periodontitis patients were significantly associated with older age (p<0.001). no significant differences were observed between periodontitis patients and controls regarding their gender (p=0.6), table (1). table 1: demographic characteristics and distribution of the study participants variable aggressive chronic control statistical test p sig. age mean 28.8±7.3 41.9±7.3 35.3±5 f=24.2 df=2 <0.001 hs age mean ± sd (37±8 years) for all groups gender variable no. % female 45 53.6 male 39 46.4 total 84 100.0 gender aggressive chronic control statistical test p sig. no. % no. % no. % male 8 17.8 19 42.2 18 40.0 χ²=0.8 0.6 ns female 10 25.6 14 35.9 15 38.5 *fishers exact test. j bagh college dentistry vol. 28(4), december 2016 detection of granulocyte oral and maxillofacial surgery and periodontics 124 clinical periodontal parameters plaque index (pli) the mean of pli in chronic periodontitis group (mean±sd) was (1.3±0.3), while in aggressive periodontitis (mean±sd) was (1±0.18). statistically a highly significant difference appeared between these two means. plaque index for controls was (0.5± 0.3). as shown in table (2). gingival index (gi) the mean values of gi were higher in chronic periodontitis group (1.37±0.48) than aggressive periodontitis (1.25±0.53). this difference in gi for cp and agp statistically nonsignificant .gi for controls was (0.24± 0.21) .as shown in table (2). probing pocket depth (ppd) the mean values of ppd were higher in aggressive periodontitis group (4.59±0.52) than chronic periodontitis group (4.38±0.48). as shown in table (2).statistically this difference is of anon-significant. clinical attachment level (cal) in table (2) reveal that the mean values of cal was higher in aggressive periodontitis group (3.3±0.87) than chronic periodontitis group (3.06±0.97).this difference statistically nonsignificant value. table 2: distribution and statistical difference of clinical parameters in study groups groups (mean±sd) pl. i (mean±sd) gi (mean±sd) ppd (mean±sd) min. pocket max. pocket cal (mean±sd) aggressive 1±0.18 1.25±0.53 4.59±0.52 4 8 3.3± 0.87 chronic 1.3±0.3 1.37±0.48 4.38±0.48 3.06±0.97 control 0.5±0.3 0.42±0.21 statistical test t-test=3.5 p=0.001 t-test =0.8 p=0.4 t-test=1.4 p=0.1 t-test=0.9 p=0.3 bleeding on probing (bop) in descriptive statistics for bop the number of sites examined for aggressive periodontitis (1764), in chronic periodontitis group were (3292). the sites that bleed were described as score 1 while non bleeding sites were described as score 0 as shown in table (3). for both groups the % of bleeding sites were much lower than the non-bleeding sites. it was (13.435%) for aggressive periodontitis and (11.817%) for chronic periodontitis. chi square test revealed a non-significant difference between them. table 3: the statistical difference in the percentage of sites bop between aggressive and chronic periodontitis sittotal site number percentages b bopbop chi p-p-value sig. score 0 score 1 0.9 0.7 ns aggressive periodontitis no.=1764 no. 1527 237 % 86.565 13.435 chronic periodontitis no.=3292 no. 2903 389 % 88.183 11.817 immunological parameter descriptive and statistical analysis of gcp2 among all studied groups the concentration of gcp2 (pg./ml) higher in serum of aggressive periodontitis group(919.14±217.3) than in chronic periodontitis group (571.9±172.6) and in control group (419.5±249.9). anova analysis revealed high significant difference in gcp2 means between aggressive, chronic periodontitis and controls (table 4). table 4: inter group comparison of gcp2 conc. (pg/ml) among all studied groups groups gcp2 (mean±sd) df f p sig. aggressive 919.14±217.3 2 47.5 <0.001 hs chronic 571.9±172.6 control 419.5±249.9 j bagh college dentistry vol. 28(4), december 2016 detection of granulocyte oral and maxillofacial surgery and periodontics 125 difference in gcp2 conc. according to gender among aggressive and chronic periodontitis patients, there was no significant difference in gcp2 means between males and females (p>0.05), on other hand, significant difference in gcp2 means between males and females among healthy controls, gcp2 mean was higher among female controls (p=0.04) (table 5). table 5: intra group differences of gcp2 conc. according to gender for all studied groups groups male (mean±sd) female (mean±sd) male (mean±sd) female (mean±sd) male (mean±sd) female (mean±sd) gcp2 900.6±283.3 915.9±163.4 586±123.6 552.9±226.8 374.9±144.7 473.1±117.1 statistical test t-test=0.1 p=0.8 t-test=0.6 p=0.5 t-test=2.1 p=0.04 inter groups statistical difference in gcp2 in both male and female anova analysis revealed high significant differences in gcp2 means between aggressive, chronic periodontitis and controls in both males and females (p<0.001) (table 6). table 6: inter-groups statistical difference of gcp2 conc. according to gender for all studied groups groups male (mean±sd) female (mean±sd) aggressive 900.6±288.3 915.9±163.4 chronic 586±123.6 552.9±226.8 control 374.9±144.7 473.1±117.1 anova d.f=2, f=27.4, p=<0.001 d.f=2, f=20.6, p=<0.001 correlation between clinical parameters and immunological parameter correlation between clinical parameters of aggressive periodontitis and gcp2 conc a significant moderate negative correlation was observed among aggressive periodontitis patients between mean plaque index and gcp2 mean (p=0.01). there was weak positive significant correlation between probing pocket depth, clinical attachment loss and bleeding on probing means with gcp2 mean (p<0.05). no significant correlation was observed between gingival index and gcp2 means (p=0.4) (table 7). table 7: pearson correlation between gcp2 conc. and clinical parameters for aggressive periodontitis patients variable gcp2 sig. r d.f p pl. i -0.6 15 0.01 s gi 0.1 15 0.4 ns ppd 0.3 15 0.04 s cal 0.3 15 0.01 s bop 0.2 15 0.02 s correlation between clinical parameters of chronic periodontitis and gcp2conc a significant weak positive correlation was observed among chronic periodontitis patients between mean gi and gcp2 mean (p=0.05). no significant correlation was observed between plaque index, probing pocket depth, clinical attachment loss and bleeding on probing means with gcp2 means (p=>0.05), (table 8). table 8: pearson's correlation between gcp2 and clinical parameters for chronic periodontitis patients. variables r d.f p sig. pl. i -0.02 30 0.8 ns gi 0.3 30 0.05 s ppd -0.07 30 0.6 ns cal 0.02 30 0.8 ns bop 0.03 30 0.6 ns correlation between clinical parameters of controls and gcp2 conc. no significant correlation was observed among healthy controls between plaque index and gingival index means with gcp2 means (p=>0.05) (table 9). table 9: pearson correlation between gcp2 conc. and clinical parameters for healthy controls variables r d.f p sig. pl. i 0.03 30 0.8 ns gi -0.07 30 0.7 ns j bagh college dentistry vol. 28(4), december 2016 detection of granulocyte oral and maxillofacial surgery and periodontics 126 inter group difference in neutrophils count (cells/μl) between aggressive periodontitis and controls statistically a significant difference between the means of neutrophil count between agp and cp groups (p=0.61). although the higher mean was within agp group. on the other hand statistically a significant difference between the means of neutrophil count of agp and controls groups and between cp and controls (table 10). table 10: mean of neutrophils count (cells/μl) among studied groups neutrophils count (mean± sd) groups 3876.0 ± 454.18 aggressive 3724.0 ± 410.95 chronic 2926.0 ± 374.005 control inter group difference in neutrophils count (cells/μl) between aggressive periodontitis and controls statistically a significant difference between the means of neutrophil count between agp and cp groups (p=0.61). although the higher mean was within agp group. on the other hand statistically a significant difference between the means of neutrophil count of agp and controls groups and between cp and controls (table 11). table 11: distribution and statistical difference in neutrophils count (cells/μl) between studied groups sig. statistical test neutrophils count (mean ±sd) groups ns ttest=0.55 p=0.61 3876.0 ± 454.18 aggressive 3724.0 ± 410.95 chronic s ttest=3.13 p=0.03 3876.0 ± 454.18 aggressive 2926± 374.005 control s ttest=4.07 p=0.01 3724.0 ± 410.95 chronic 2926± 374.005 control discussion the aim of this study is to evaluate the serum level of gcp2 in patients with agp, cp and healthy controls. the study is the first of its kind and there are no previous studies comparing the serum level of gcp2 between the three mentioned groups, therefore comparing the results not possible. the most exposed to agp were young age and that agreed to the (9) and as in past classification of periodontitis (10,11),although elimination the age criteria is possibly one of the most important innovations of aap 1999 consensus classification of periodontal disease published by armitage (12(. also in our study cp affect people of all ages and with age increase and this agreed with albandar and rams (13). chronic periodontitis group comprised of significantly elder patients compared to agp and healthy controls groups and that agreed with cifcibasi et al. (14). genetic or systemic factor are associated with cp, while the predisposing factor for agp is the families history of periodontal disease. according to fourel (15), one of the constant parameters in eop currently classified as agp is the existence of a familial factor . pi scores were significantly higher in cp than agp and healthy controls and that agreed with cifcibasi et al. (14) and disagreed with anisehnaderan et al. (16). no significant difference in mean of gi, ppd, cal between chronic and aggressive periodontitis and that agreed with cifcibasi et al. (14) and disagreed with benoist et al. (17). the level of serum gcp2 is higher in periodontitis patients than controls as in result of kebsckull et al. (18) who showed a high expression of gcp2 in disease gingival tissue than healthy gingival tissue and the level of gcp2 in the study of kebsckull et al. (18) correlate positively with ppd and not with cal that reflects current periodontal inflammatory status and not history of periodontitis. while the gcp2 level in the present study correlate positively even it is a weak correlation with ppd and cal a significant difference was found in neutrophils count between periodontal diseases and controls. low count in controls and high count in diseases and that is agreed with bender et al. (19). high count of neutrophils in aggressive periodontitis agreed with buchmann et al. (20) and disagreed with genco (21). also elevated neutrophils count in chronic periodontitis agreed with hidalgo et al. (22). as high gcp2 in aggressive periodontitis that increased chemotactant of neutrophils to the inflamed sites that increase the destruction of tissues in agp and that is agreed with kantarci and van dyke (23). references 1. darveau rp. periodontitis: a polymicrobial disruption of host homeostasis. nat rev microbiol 2010; 8(7): 481-90. j bagh college dentistry vol. 28(4), december 2016 detection of granulocyte oral and maxillofacial surgery and periodontics 127 2. scott da, krauss j. nutrophils in periodontal inflammation. front oral biol 2012; 15: 56-83 3. oppenheim j, zachariae c, mukaida n, matsushima k. properties of the novel proinflammatory supergene ‘‘intercrine’’ cytokine family. ann rev immunol 1991; 9: 617 – 48. 4. proost p, de wolf-peeters c, conings r, et al. identification of a novel granulocyte chemotactic protein (gcp-2) from human tumor cells. in vitro and in vivo comparison with natural forms of gro, ip-10, and il-8 . j immunol 1993; 150:1000-10. 5. silness p, löe h. 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and the monitoring of chronic periodontal disease. j periodontal res 2006; 41: 214-20 20. buchmann r, hasilik a,van dyke te, lang de. amplified crevicular leukocyte activity in aggressive periodontal disease. j dent res 2002; 81: 716-21 21. genco rj. current view of risk factors for periodontal diseases. j periodontol 1996; 67:1041–9 22. hidalgo mm, avila-campos mj, trevisan w, jr, mocelin tt, itano en. neutrophil chemotaxis and serum factor modulation in brazilian periodontitis patients. arch med res. 1997; 28: 531–5. 23. kantarci a, van dyke te. lipoxin signaling in neutrophils and their role in periodontal disease. prostaglandins leukot essent fatty acids 2005; 73: 289-99. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 1 (2022), issn (p): 1817-1869, issn (e): 2311-5270 60 research article in vitro cytotoxic effect of annona squamosa pulp extract as a mouthwash for children on human normal cell line sumaia hussein ali 1,*, zainab juma jafar 2 1 master student, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. 2 assistant professor, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. bab-almoadham, p.o. box 1417, baghdad, iraq * correspondence: sumiahao24@gmail.com abstract: background: fruits and their by-products are the primary sources of bioactive chemicals in plants. because of its phytochemical richness, annona squamosa fruits have gained the alertness of people willing in health-promoting diets. the purpose of this in vitro study was to evaluate the cytocompatibility effect of ethanolic crude extract of annona squamosa pulp against a human normal cell line as a mouthwash for children. material and method: the ethanolic extract of annona squamosa pulp was extracted using the ultrasonic method and then lyophilized to make it powder. the mtt (3-(4,5-dimethylthiazol-2-yl)-2,5diphenyl-2h-tetrazolium bromide) test was performed to investigate the cytotoxic activity of the pulp extract on a human normal cell line derived from human dermal fibroblast, neonatal (hdfn). plates were then incubated with 5% co2 at 37°c for the following concentrations (400, 200, 100, 50, 25, 12.5, 6.25 g/ml). each concentration, as well as the positive control chlorhexidine, and the negative control cells without tested material, were tested in triplicate. results: no significant difference was found between the cytotoxicity of the ethanol crude extract of annona squamosa and a chlorhexidine (p = >0.05) against human dermal fibroblast of neonate cells, with ic50 (50% growth inhibition of cells) values of 235.4 μg/ml while chlorhexidine had an ic50 of 97.8 μg/ml. conclusion: annona squamosa extract is more safe and has less cytotoxicity than chlorhexidine. so, to overcome the problems of chlorhexidine, herbal mouthwash formulations could be utilized as an alternative mouthwash. keywords: mosmann’s tetrazolium toxicity assay (mtt assay), cytotoxicity, annona squamosa, chlorhexidine, human dermal fibroblast of neonate (hdfn) cell line. introduction the main etiological component contributing to periodontal diseases and dental caries is dental plaque (microbial biofilm). as a result, to avoid plaque production and accumulation on the tooth surface, effective plaque control techniques such as toothbrushes and dental floss, as well as mouthwashes as an adjunctive to these mechanical methods due to a lack of manual skill and motivation, particularly in children (1). chlorhexidine is regarded as the gold standard mouthwash and is the most widely recommended antibacterial and antiseptic agent. but unfortunately, tooth discoloration, burning sensations, oral ulcer and a change in taste after prolonged usage, all of which are reported side effects of chlorhexidine which limit patients’ compliance and cause research about natural products to be safe with minimal adverse effects (2). despite the fact that the use of medicinal plants is an ancient tradition, it is still the major method for treating a lot of diseases in a diverse population and communities in many nations (3). herbal medicines are becoming more popular due to their fewer side effects on the biological environment and on nontargeted human cells (4). as a result, plant extracts and their separated components have received a lot of attention in the study for newer medicinal agents (5). according to the world health organization (who), traditional medicines are used by more than 80% population of the world to meet their needs for primary health care. alkaloids, flavonoids, tannins, and phenolic compounds were thought to be the most important bioactive substances in plants (6). annona squamosa l. is a species of annona (annonaceae family) that is known by several names in various languages: sweetsop, sugar apple, sweet apple, and gishta (7). it received date: 15-11-2021 accepted date: 28-12-2021 published date: 15-3-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbcd .v34i1.3093 mailto:sumiahao24@gmail.com https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3093 https://doi.org/10.26477/jbcd.v34i1.3093 j. bagh. coll. dent. vol. 34, no. 1. 2022 ali and jafar 61 is a small tropical tree with up to 8 meters height, with round or heart-shaped greenish-yellow fruit. the pulp is edible and beautifully aromatic, with a white-tinged yellow color. every carpel has an oval, shining, smooth, and dark colored seed within (8). therefore, it is a popular plant that is mostly cultivated in gardens for its tasty fruit and high scenically appeal. all parts of this plant, including the leaves, barks, seeds, and fruits, possess medicinal chemicals and have thus been used to treat a variety of ailments because it contains a variety of phytochemicals such as alkaloids, acetogenins, flavonoids, saponins, phenols, sterols, carbohydrate and tannins (9). the fruits are a high source of calcium, phosphorus and iron and are usually consumed fresh or used to produce sorbet or juice beverages. flavonoids, alkaloids, and acetogenins are chemical compounds have all been derived from the seeds and other parts of these plants, therefore; antibacterial effects of flavonoids and alkaloids have led to their use in the treatment of medical conditions such as skin disease, intestinal worms, and eye inflammation (6,10). the ethno botanical study on annona squamosa's selective cytotoxic effect has increased its popularity and application in the treatment of numerous ailments (11). gubta et al. (12) showed by their study for one month on animals, that it is an edible fruit with great nutritional content and it shows protective activity at a specific dosage without any harmful effect on the heart and liver of rats. antimicrobial activity refers to the process of destroying or inhibiting disease-causing bacteria. several antimicrobial agents, such as antibacterial, antiviral, and antifungal substances, are employed for this purpose. for each of them, there are several modalities of action for infection suppression (13, 14). the aerial portions of the plant have antibacterial, anti-diabetic, anti-hyperlipidemic, anti-microbial, antioxidant, anti-head lice effect, anti-tumour, hepatoprotective, insecticidal, anti-lipidperoxidative, mosquitocidal, anti-thyroidic (10). the mtt assay can be used to test prospective medications in vitro and to investigate drug resistance in cell lines. it also aids in the determination of medication effects in vitro and clinical usage prognosis (15). the test is the most sensitive, precise and widely used method for detecting cytotoxicity and cell viability following toxic chemical exposure (16, 17). as a result, this assay is an extremely valuable tool for testing materials’ cytotoxicity or discriminating between several cell lines because it generates considerable data in a short amount of time, has excellent sensitivity and reproducibility, and is affordable in cost (18, 19). the present research focuses on the effect of annona squamosa fruit pulp on cell growth viability after estimation of its antimicrobial effect as a mouthwash for children in another research. organic extracts of annona squamosa fruit pulp were tested on a normal cell line of human origin for antimicrobial effect, which could make it a source for generating innovative antimicrobial therapeutic products from nature. materials and methods annona fruits collection the annona squamosa fruit (lebanon) was collected from baghdad's local market (baghdad/iraq). it was gently washed with distilled water to remove dust, then dried and peeled. the fruit pulp was cleared from the seeds and bark by hand, and the pulp was chopped into little pieces. after that, the samples were placed in a plastic container and shipped to a lab for extraction. alcoholic extraction of annona fruit the extract was prepared by the ministry of science and technology in baghdad, iraq. the prepared fresh pulp was sonicated with ethanol at 60°c for 30 minutes. after that, the extract was evaporated by a rotary evaporator under a vacuum (20). the alcoholic extract was kept in glass containers and frozen before being lyophilized to get powder extracts, dimethyl sulfoxide (dmso) was used to dissolve the extracted powder to prepare various dilutions at varying concentrations (400, 200, 100, 50, 25, 12.5, and 6.25) g/ml according to a pilot study. cell line culture and maintenance j. bagh. coll. dent. vol. 34, no. 1. 2022 ali and jafar 62 the human normal cell line from hdfn (human dermal fibroblasts of neonate) were cultured in roswell park memorial institute medium (rpmi 1640; sigma usa). mtt assay was conducted in the centre of natural product research & drug discovery, university of malaya, malaysia. after the cells in the flask established a confluent monolayer, the cell sheet was rinsed in phosphate buffer saline after the growth medium was emptied. the cells were then treated with a 2 to 3 ml solution of trypsin. the cells were allowed to incubate for 1 minute at 37°c until they were dislodged from the container and became isolated cells instead of a single-celled layer. then fresh, complete rosewell park memorial institute (rpmi) media was applied. cells are then distributed at the desired concentration into culture flasks if required and maintained for 24 hours at 37°c in a 5 percent co2 incubator (21). cell viability assay (mtt assay) in vitro evaluation of the cytotoxicity of annona squamosa extract by the most common, rapid, and simpler mosmann’s tetrazolium toxicity assay (mtt) uses a yellow dye (3-[4,5-dimethyllthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) that transforms into purple formazan. this reaction occurs by the splitting of the tetrazolium ring by the mitochondrial enzyme (succinate dehydrogenase) of living cells, and this enzyme is found only in healthy, viable cells (22). in 96 plane base wells of micro-plates, normal cells (1x104 – 1x106 cells/ml) were grown in 200 l as final volume per well of complete culture media. the plates were then incubated for 24 hours in a co2 incubator at 37°c. the medium was withdrawn after the incubation period, and the wells were filled with the prepared concentrations of annona squamosa extract and the positive control chlorhexidine 0.12% (6.25, 12.5, 25, 50, 100, 200, 400) µg/ml and incubated with 5% co2 at 37°c for 24 hours. in the same plates, cells control without extract were included as a negative control. every well-received 10 μl of mtt solution and then incubated for another 4 hours with 5% co2. after that, the media were removed, and each well-received 100 μl of solubilization solution in order to dissolve crystals of formazan. the cytotoxic effect of the tested extract and the positive control were presented as an ic50 value, which means that (50% inhibitory concentration of normal cells). at a wavelength of 570 nm, the absorbance was measured using an elisa reader (22). triplicates of every concentration, and even the positive controls, were employed. the effect was measured according to the equation: viability (%) = optical density of sample ×100% / optical density control statistical analysis data description and analysis were performed using a one-way analysis of variance anova to determine the level of significance at a p value of (0.05). results were displayed as mean, standard deviation and statistical significances were executed by graph pad prism version 8 (graph pad software inc., la jolla, ca). results the production of formazan crystals related to decrease mtt tetrazolium by living cells was measured to determine cell viability. the dose-response viability of human dermal fibroblast cells treated with the annona squamosa extracts and the positive control chlorhexidine of different concentrations to determine the ic50 (50% growth inhibition of cells) by mtt assay are presented in table 1 and 2 as the data were expressed by means, standard deviation. annona squamosa concentrations of 100, 50, 25, 12.5 and 6.25 caused less toxic effects to the cells. while higher cytotoxicity to the hdfn cells was observed as the annona squamosa concentration increased. moreover, the concentrations (50, 25, 12.5, and 6.15) g/ml of both test and control have high cell viability than the concentrations (100,200,400) g/ml, which means it is a dose-dependent cytotoxic effect of the substance. in addition, the ic value of this assay for annona squamosa for all concentrations was higher than chlorhexidine (0.12%) (235.4 μg/ml and 97.8 μg/ml respectively) as shown in figure 1 (a and b). j. bagh. coll. dent. vol. 34, no. 1. 2022 ali and jafar 63 table 1: cell viability of the annona squamosa extract and the positive control chlorhexidine at different concentrations by mtt assay. concentration annona squamosa mean std. deviation chlorhexidine mean std. deviation 400 66.71 3.275 74.27 4.757 200 73.26 4.130 76.70 2.609 100 81.98 2.561 84.34 2.663 50 89.58 1.478 86.07 1.917 25 94.17 0.6581 95.22 0.8209 12.5 94.48 1.794 95.95 1.028 6.25 94.41 0.4818 95.95 0.2003 mtt= mosmann’s tetrazolium toxicity figure 1: half-maximal inhibitory concentration of cells on human dermal fibroblast of neonate cell line of (a) annona squamosa pulp extract (b) the positive control chlorhexidine gloconate 0.12% independent samples t-test was performed as demonstrated by table 3 and figure 2 to determine the significance of differences in cells viability mean values between the tested materials in different concentrations. the test showed no significant differences on hdfn cells between groups in all concentrations but only in concentration 400 g/ml there was a significant difference between the annona squamosa and the chlorhexidine. table 3: independent samples t-test to compare the significance of differences in cells viability mean values between the annona squamosa in comparison to chlorhexidine gloconate 0.12%. a. squamosa chlorhexidine gloconate adjusted p value significance 400 0.0048 s 200 0.4988 ns 100 0.8598 ns 50 0.4719 ns 25 0.9984 ns 12.5 0.9875 ns 6.25 0.9832 ns ns= not significant at p>0.05, s=significant at p<0.05. j. bagh. coll. dent. vol. 34, no. 1. 2022 ali and jafar 64 figure 2: graph showing the means of cells viability (%) of annona squamosa and the positive control chlorhexidine 0.12% and negative control at different concentrations. discussion the mtt is the most commonly used test to identify the cytotoxic effect of various substances under various conditions or concentrations. human dermal fibroblasts from neonates were applied in this study because their main properties were nearly equivalent to human gingival fibroblasts (23). by comparing the survivability of the control and drug-treated groups, the ic50 value (50 percent half inhibitory concentration) of applicable medications may also be determined (24). consequently, this in vitro experiment was carried out to assess the cytotoxicity of annona squamosa at various doses compared with chlorhexidine gloconate 0.12%. it was noted that the effect of annona squamosa on hdfn after 24 hours was dose-dependent, meaning that low doses of annona squamosa have minimal effect on cell viability, implying that exposure to annona squamosa at the ic50 dosage resulted in considerable viability of human cells which is higher than that of chlorhexidine gloconate 0.12%, that’s mean; halve of the concentration of viable cells are more when the annona squamosa used (ic50 were 235.4 μg/ml and 97.8 μg/ml for annona squamosa and chlorhexidine gloconate 0.12% respectively). the finding demonstrates that the higher the cell concentrations of annona squamosa, the more toxic of the herbal agent above 400 g/ml concentration, which is similar to the results obtained by another study regarding the safety and cytotoxicity of fruit’s pulp in vivo and in vitro experiments (11). additionally, annona squamosa was approved by fda (food and drug administration) (25) and it is safe fruit for eating. in regard to the comparison with chlorhexidine gloconate 0.12%, because this is a series of research that introduces the annona squamosa pulp extract as a mouthwash for children which implicates the antibacterial effect of annona squamosa compared with chlorhexidine, we search for this cytotoxic effect as compared with chlorhexidine, which is suitably used for children (if necessary) and considered the gold standard mouthwash at this concentration. the use of medicinal plants in treating and preventing oral problems can have occasional advantages for rural populations or those in poor socioeconomic conditions due to the low cost and accessibility of j. bagh. coll. dent. vol. 34, no. 1. 2022 ali and jafar 65 herbs in various portions of the country. as a result, medicinal herbs may be a viable substitute for traditional antimicrobials (26), as well as to avoid the side effects associated with chemical agents found in some medications used now. conclusion the present study of ethanolic crude extract of annona squamosa pulp and the positive control chlorhexidine gloconate 0.12% displayed different degrees of cell viability according to concentrations used, and the cell viability toward hdfn cells increased with decreased concentrations, so it is dose-dependent toxic effect. annona squamosa has no or minimal cytotoxicity on human fibroblast cells and can be utilized in dentistry applications as a safe substitute to chlorhexidine gloconate 0.12% for prevention and treatment of oral bacterial-induced diseases. conflict of interest: none. references 1. deshpande, a., deshpande, n., raol, r, et al. effect of green tea, ginger plus green tea, and chlorhexidine mouthwash on plaqueinduced gingivitis: a randomized clinical trial. j indian soc periodontol. 2021; 25(4):307. 2. vinod, ks., sunil, ks., sethi, p., et al. a novel herbal formulation versus chlorhexidine mouthwash in efficacy against oral microflora. j int soc prev community dent. 2018; 8(2):184. 3. sharma, h., kumar, a. ethnobotanical studies on medicinal plants of rajasthan (india): a review. j med plants res. 2011;5(7):1107-1112. 4. wang, ds., rizwani, gh., guo, h., et al. annona squamosa linn: cytotoxic activity found in leaf extract against human tumor cell lines. pak j pharm sci. 2014; 27(5):1559-1563. 5. gurib-fakim, a. medicinal plants: traditions of yesterday and drugs of tomorrow. mol aspects med. 2006; 27(1):1-93. 6. gajalakshmi, s., vijayalakshmi, s., devi, rv. phytochemical and pharmacological properties of annona muricata: a review. int j pharm pharm sci. 2012; 4(2):3-6. 7. wunderlin, r., hansen, b. synonyms of annona squamosa. atlas of florida vascular plants. 2008:24-27. 8. das, s., bhattacharya, a., ghosh, b., et al. analytical and phytochemical exploration of the seeds of annona squamosa. j anal pharm res 2016; 3(4):00065-00070. 9. vyas, k., manda, h., sharma, rk., et al. an update review on annona squamosa. int j pharm therapeut. 2012; 3(2):107-118. 10. pandey, n., barve, d. phytochemical and pharmacological review on annona squamosa linn. int j res pharm biomed sci. 2011; 2(4):1404-1412. 11. chimbevo, lm. efficacy and safety, nutritional and antioxidant activity of kenyan annona muricata (l.) and annona squamosa (l.) fruits extracts in balb/c mice model of l. major leshmaniasis (doctoral dissertation, jkuat-cohes), 2020. 12. gupta, rk., kesari, an., watal, g., et al. nutritional and hypoglycemic effect of fruit pulp of annona squamosa in normal healthy and alloxan-induced diabetic rabbits. ann nutr metab. 2005; 49(6):407-413. 13. tong, sy., davis, js., eichenberger, e., et al. staphylococcus aureus infections: epidemiology, pathophysiology, clinical manifestations, and management. clin microbiol rev. 2015; 28(3):603-661 14. ahmad, h., ali, n., ahmad, b., et al. screening of solanum surrattense for antibacterial, antifungal, phytotoxic and haemagglutination. j tradit chin med. 2012; 32(4):616-620. 15. adan, a., kiraz, y., baran, y. cell proliferation and cytotoxicity assays. curr pharm biotechnol. 2016; 17(14):1213-1221. 16. decker, t., lohmann-matthes, ml. a quick and simple method for the quantitation of lactate dehydrogenase release in measurements of cellular cytotoxicity and tumor necrosis factor (tnf) activity. j immunol methods. 1988; 115(1):61-69. j. bagh. coll. dent. vol. 34, no. 1. 2022 ali and jafar 66 17. fotakis, g., timbrell, ja. in vitro cytotoxicity assays: comparison of ldh, neutral red, mtt and protein assay in hepatoma cell lines following exposure to cadmium chloride. toxicol lett. 2006; 160(2):171-177. 18. rogero, so., lugão, ab., ikeda, ti., et al. teste in vitro de citotoxicidade: estudo comparativo entre duas metodologias. mater res.. 2003; 6(3): 317-320. 19. trintinaglia, l., bianchi, e., silva, lb., et al. cytotoxicity assays as tools to assess water quality in the sinos river basin. braz j biol. 2015; 75(2):75-80. 20. trindade, ml., radünz, m., ramos, ah., et al. chemical characterization, antimicrobial and antioxidant activity of sugar-apple (annona squamosa l.) pulp extract. rev chil nutr. 2020; 47(2):281-285. 21. freshney, ri. 'culture of animal cells, a manual of basic technique and specialized applications, sixth ed., wileyblackwell, 2010. 22. mosmann, t. rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assay. j immunol methods. 1983; 65: 55–63. 23. ebisawa, k., kato, r., okada, m., et al. gingival and dermal fibroblasts: their similarities and differences revealed from gene expression. j biosci bioeng. 2011; 111(3): 255-258. 24. berridge, mv., herst, pm., tan, as. tetrazolium dyes as tools in cell biology: new insights into their cellular reduction. biotechnol annu rev. 2005; 11: 127-152. 25. fda: pesticide analytical manual volume i (pam) 3rd edition find in https://www.fda.gov/food/laboratory-methods-food/pesticide-analytical-manual-volume-i-pam-3rd-edition. 26. karbach, j., ebenezer, s., warnke, ph., et al. antimicrobial effect of australian antibacterial essential oils as alternative to common antiseptic solutions against clinically relevant oral pathogens. clin lab.2015;61(1-2):61-68. البشري الطبيعي الخاليا خط على لألطفال للفم كغسول المختبري لمستخلص فاكهة القشطة للخاليا السام التأثير العنوان: 2 , زينب جمعة جعفر 1سمية حسين علي الباحثون: المستخلص: النباتي، اكتسبت ثمار انونا سكواموزا مؤخًرا انتباه األشخاص الخلفية: الفاكهة ومنتجاتها الثانوية هي المصادر األساسية للمواد الكيميائية النشطة بيولوجيا في النباتات. بسبب ثرائها الكيميائي ثانولي من لب أنونا سكواموزا ضد خط الخلية اغبين في اتباع أنظمة غذائية تعزز الصحة. كان الغرض من هذه الدراسة المختبرية هو تقييم تأثير التوافق الخلوي للمستخلص الخام اإليالر الطبيعي البشري كغسول فموي لألطفال. -mtt (3(4،5 ختبارالمواد وطرق العمل: حّضر المستخلص اإليثانولي من لب انونا سكواموزا بطريقة الموجات فوق الصوتية ثم جّمد لعمل المسحوق. تم إجراء ا dimethylthiazol-2-yl) -2،5-diphenyl-2h-tetrazolium bromide) للتحقق من النشاط السام للخاليا لمستخلص اللب على خط الخاليا الطبيعي البشري المشتق من الخاليا مجم / مل(. 6.25 ،12.5 ،25 ،50 ،100 ،200، 400يزات التالية )درجة مئوية للترك 37في co2٪ 5تم تحضين األلواح بعد ذلك بـ .(hdfn) الليفية الجلدية البشرية لحديثي الوالدة .وبعدها اختبار كل تركيز باإلضافة إلى العينات الموجبة والسالبة للمقارنة في ثالث نسخ تخلص اإليثانول الخام من انونا سكواموزا القليل من السمية أظهر مس .(p => 0.05) النتائج: لم يُعثر على فرق معنوي بين السمية الخلوية لمستخلصات انونا سكواموزا والكلورهيكسيدين .ميكروغرام / مل 97.8من ic50 ميكروغرام / مل بينما كان الكلورهيكسيدين يحتوي على ic 235.4 ، مع قيمhdfn الخلوية ضد خاليا يمكن الكلورهيكسيدين،أعلى من الكلورهيكسيدين. لذلك للتغلب على مشكالت ic50الطبيعية لإلنسان مع االستنتاج: يُظهر مستخلص أنونا سكواموزا تأثيًرا طفيفًا على قابلية بقاء خط الخاليا واستخدام تركيب غسول الفم من أنونا سكواموزا كغسول فم بديل dhiaa f.doc j bagh college dentistry vol. 28(2), june 2016 the influence of pedodontics, orthodontics and preventive dentistry 119 the influence of caries infiltrant combined with and without conventional adhesives on sealing of sound enamel (in vitro study) marwa balasim, b.d.s. (1) dhiaa j. n. al-dabagh, b.d.s., m.sc. (2) abstract background: the formation of white spot lesions around fixed orthodontic attachments is a common complication during and after fixed orthodontic treatment, which hinders the result of a successfully completed orthodontic treatment. the aim of the study was to assess the effectiveness of the caries infiltrant (icon®) on prevention of caries on the smooth enamel surface when applied alone or combined with conventional adhesives. materials and methods: seventy eight human premolar enamel discs were randomly assigned to six groups (n=13). the discs were etched and treated with resins of different monomer content forming the following groups: (1)untreated etched samples served as the negative control, (2) icon® (dmg), (3) adper™ sb 2 (3m espe), (4) heliobond (ivoclarvivadent), (5) icon®+ adper™ sb 2 and (6) icon®+ heliobond. specimens were subjected to demineralization by immersion in hydrochloric acid (ph 2.6) for 18 days. calcium dissolution into the acid was assessed by photometric test via spectrophotometer at 24 hour intervals. results: the results revealed that, there was a highly significant difference between the sealed groups and the unsealed (untreated) one (p≤0.00) indicating that the unsealed specimens showed the highest amount of ca ion loss among all other groups. additionally, there was no significant difference between untreated specimens and the icon® sealed ones. while, heliobond decreased the ca ion loss significantly compared to the untreated specimens and adper™ sb 2 performed significantly better than both icon® and heliobond. furthermore, the combination of icon® with either adper™ sb 2 or heliobond served as the best protective measures and maintained the protective effect during the whole experiment period. therefore, within the limitations of this in vitro study, it could be concluded that the use of caries infiltrant prior to the application of the tested conventional adhesives increases their protective effect against demineralization. key words: white spot lesions, sealants, infiltrants, icon®. (j bagh coll dentistry 2016; 28(2):119-125). introduction the fixation of orthodontic brackets enhances plaque retention and this favors the development of demineralization and initial caries around the brackets when the oral hygiene of the patient is poor (1). studies have shown that, compared with nonorthodontic patients, orthodontic patients are much more vulnerable to the demineralization of enamel with a rate of 4.9% to 84% (2). as carbohydrates consumed daily, they are fermented by the bacteria that colonized in the plaque and lead to decrease the intraoral ph. the low ph results in dissociation of calcium and phosphate ions from enamel in an attempt to reach chemical equilibrium in the oral environment (3,4). it was found (5,6) that 24% and 11%patients, respectively, with existing wsls at the time of bracket fixation. in addition to that,(7)the prevalence of these acquired surface lesions due to orthodontic treatment is relatively high, affecting more than 40% to 60% of patients. also, these lesions can appear very rapidly, as fast as in a couple of weeks after the placement of brackets (8). therefore, different attempts have been made (1)m.sc. student. department of orthodontics. college of dentistry, university of baghdad. (2)professor. department of orthodontics. college of dentistry, university of baghdad. to increase the caries resistance of enamel prior to and during fixed orthodontic treatment (e.g. application of fluoride or casein-phosphateamorphous). other preventive measures are chlorhexidine mouth rinses, ozone applications, probiotics, xylitol, and sealants (9,10). another suggestion was about the use of an adhesive patch as an intermediate layer under metal brackets to prevent demineralization under and around the bracket to relocate the bracketpatch margins to areas that are easier to access for oral hygiene (9). additionally, many studies (10,11) discussed the use of different (fluoridated) bonding agents and sealants as a means to protect the surrounding enamel from demineralization. previously, many authors (4,12) stated: "preventive measures that do not require patient compliance are considered more predictable since only 13% of the patients were reported to achieve excellent cooperation with the use of mouth rinses and tooth brushing". while (13,14) remineralization of (wsls) do not disappear unless they are removed mechanically by abrasion, etching, or masking by resin infiltration or treated in a restorative fashion. therefore, (9,15) sealing the susceptible enamel prior to bracket bonding in order to form a cariesprotective shield has been the focus of interest in j bagh college dentistry vol. 28(2), june 2016 the influence of pedodontics, orthodontics and preventive dentistry 120 previous studies that primarily intend to eliminate patient compliance. in principle, sealants cover the whole buccal surface adjacent to brackets, forming a physical barrier. this protective shield is subjected to physical challenges such as acid attacks from bacterial plaque and acidic soft drinks as well as daily tooth brushing, which might impair the seal (4,8,9,15). in recent years, many clinical trials (16,17) showed that, the caries progression of lesions infiltrated with a low-viscosity resins that have a high capability for penetrating initial carious lesion is significantly reduced. but, it was (18,19) found that, although resin infiltrants were originally developed for penetration into carious lesions and occlusion of diffusion pathways, they also prevented enamel surface demineralization to some extent. in contrast, to conventional sealants, where the physical barrier remains on the enamel surface as a covering coat, this infiltrant presents rapid capillary penetration into the pores creating a diffusion barrier within the enamel with very low-viscosity and superior surface wetting abilities. in addition to that, new retention areas for plaque accumulation at the sealed margins are being avoided. however, in spite of the deeper penetration of carious lesions where is a porous structure for the resin to infiltrate, it has not been shown if this resin can infiltrate phosphoric acid etched sound enamel where only limited capillary diffusion is imaginable (20). very little information have been gained regarding the effect of caries infiltrants on human teeth when they subjected to orthodontic treatment. therefore, it is intended to implement this study in this field of dentistry. materials and methods sound human premolars, two conventional adhesive resins (adper ™ single bond 2 and heliobond) and lowviscosity caries infiltrant icon® were employed in this in vitro study. the adhesives used were conventional bonding agents with different ratios of bis-phenol-a-glycidyl methacrylate (bis-gma) and triethylene glycol dimethacrylate (tegdma) content. the lowviscosity caries infiltrant was tegdma-based. the chemical compositions of the materials are summarized in table 1. study design: seventy eight enamel discs cut from the buccal aspect of each collected premolar just below the buccal cusp tip to get a valid thickness of enamel. the discs randomly assigned into 6 groups (n=13) to be sealed with different bonding agents. these agents were conventional bonding agents and infiltrant with different ratios of (bis-gma) and (tegdma). unsealed control, caries infiltrant, conventional orthodontic bonding agent (adper ™ single bond 2), unfilled bonding agent (heliobond), caries infiltrant+ conventional orthodontic bonding agent, and caries infiltrant+ unfilled bonding agent.all the discs were subjected to 18 days acidic challenge for demineralization and ca ion conc. was measured every 24 hrs using photometric test for ca ion via spectrophotometer. sample preparation: collected teeth were cleaned from blood and gross debris by rinsing with tap water (21). then, they were polished with oil free pumice and prophylactic rubber cup (five teeth per one cup) adjusted to a lowspeed hand-piece. they were dried and tested by magnifying lens and light cure illumination for detection of cracks and preexisting defects (22,23).then, stored in 0.9 % nacl, for no longer than two months to prevent dehydration and cross contamination. the stored and cleaned premolars milled and shaped to have a (3mm diameter and 2mm thickness) by using torna and micro-engine under water cooling.the buccal surface ground flat with full diamond disc. all the cutting procedure involved water cooling. then discs embedded in a costume made silicone cylindrical mold (6mm in diameter and 6mm in depth). the embedded polished with rubber cups and oil free pumice, cleaned with air/ water syringe and stored in double recycled distilled water thereafter. sealing procedure: after dying (15 sec. for each specimen), all specimens were etched with 38% phosphoric acid gelfor 20 sec. and then rinsed with copious amount of water for 30 sec. the bonding procedure for all of the specimens (except the unsealed group) as in the following manner: 1caries infiltrant: ethanol (icon-dry) was applied by using the manufacturer syringe for 30 sec. and dried for 10 sec. then, the low viscosity caries infiltrant (icon® infiltrant) was emptied in dippen dish. it was applied in one coat with a micro-brush and let set for 3min., then light cured for 60 sec.; a second layer was applied, let set for 1 min., and light cured for 40 secaccording to manufacturer information. 2conventional bonding agent: adper™ single bond 2. two coats of bonding agent were applied with a fully saturated micro-brush, j bagh college dentistry vol. 28(2), june 2016 the influence of pedodontics, orthodontics and preventive dentistry 121 while massaging in over the entire surface for 15 sec. air thinning for 5 sec. to evaporate the solvent and light cured for 10 secaccording to manufacturer information. 3unfilled bonding agent: heliobond was applied in one coat with a micro brush and light application of an air jet for 5 sec. then light cured for 10 secaccording to manufacturer information. 4caries infiltrant + conventional bonding agent: steps 1 and 2 were repeated subsequently. 5caries infiltrant + unfilled bonding agent: steps 1 and 3 were repeated subsequently. all procedures involving air/water jet and light curing unit were performed using a custommade devices assuring standard distance to the specimens from the application tips of triple syringe and light curing unit. the distance was 2 cm from air/water syringe tipstoeach specimen. the intensity of the light was 1600 mw/cm² at light guide tip; 1110 mw/cm² at 4 mm distance from the specimen. the irradiance of light was checked by a radiometer (digirate – radiometer, lm-100, monitex, taiwan). the light-curing unit was checked at the beginning and after five applications for constant output. following these pretreatments, the specimens were stored in distilled water for 24 hours at 37 °c for complete polymerization. acidic challenge and evaluation of sealing ability: all specimens were immersed in hydrochloric acid (ph 2.6) for 18 days. sealing ability was quantified by the amount of ca released from the specimens into the acid solution using photometric test for ca via spectrophotometer. twenty µl of the acid solution was added to the test tubes and mixed with 1 ml of the color reagent (ca ion liquicolor 200ml complete test kits, human gmbh max-planck-ring 21, 65205 wiesbaden – germany). absorbance was read at 570 nm in the spectrophotometer reader. the measurements were performed at a room temperature of 25° c according to manufacturer information of ca ion kit. table 1: composition of the low-viscosity caries infiltrant and the conventional bonding resins according to the manufacturers’ information. results data were collected and analyzed using spss (statistical package of social science) software version 15 for windows xp chicago, usa.the unsealed samples showed higher mean values of ca ion conc. than all other tested samples during every day of the estimated period (18 days). anova showed a significant difference (p < 0.000) among the mean values of ca ion conc. of the test's groups in each tested day and during the whole tests period.lsd showed that there was a highly significant difference between the sealed groups and the unsealed one (p≤0.00) except between (g1: unsealed group and g2: icon® infiltrant sealed group) there was no significant difference. while, there was a significant difference between (g2: icon® infiltrant sealed group) and the other sealed groups except for the (g4: heliobond sealed group), with no significant difference was present between them. furthermore, there was no significant difference between (g3: adper™ single bond 2 sealed group) and the other sealed group. but, a significant difference found between the (g4: heliobond sealed group) and the combined group (g5: adper™ single bond 2 + icon® sealed group), while there was no significant difference between g4 and (g6: heliobond + icon® sealed group). also, between the two combined groups there was no significant difference (table 2), (figure 1). product chemical compositions manufacturer 1) icon® (infiltrant) 0.45 ml 2) icon® (dry) tegdma-based resin matrix, initiators – additives. ethanol. dmg, hamburg, germany; batch 220402 adper™ single bond2 6g bisgma 10%-20% ,hema 5% , nanofillers 10%-20%, dimeth-acrylates, water, a novel photo-initiator system and a methacrylate functional copolymer of polyacrylic and polyitaconic acids, ethanol 25%-35%. 3m espe, st. paul, mn u.s.a; batch n435767 heliobond 6g bis-gma 50% 100% tegdma 25%50% initiators – stabilizers. ivoclarvivadent, schaan, liechtenstein; batch p82828 j bagh college dentistry vol. 28(2), june 2016 the influence of pedodontics, orthodontics and preventive dentistry 122 table 2: descriptive statistics and groups comparison of the daily ca ion conc. during the whole study period (18 days). groups mean s.d. min. max. f-test p-value g1 2.08 0.65 0.95 2.92 7.745 0.000 (hs) g2 1.73 0.66 0.71 2.67 g3 1.16 0.72 0.28 2.34 g4 1.39 0.74 0.33 2.53 g5 0.93 0.64 0.08 1.96 g6 1.03 0.67 0.17 2.19 figure 1: cumulative ca ion conc. in mmol/l over 18 days of acidic challenge revealed that unsealed specimens (g1) released the highest amount of ca ion while, the other specimens released the less specially the combined ones (g5 and g6). discussion enamel decalcifications affect many orthodontic patients. these decalcifications named as wsls; they are caused by inadequate oral hygiene that leads to plaque accumulation around orthodontic appliances. other factors that predispose a patient to wsls are appliance design, cement lute failure, poor salivary flow and composition, enamel susceptibility, and dietary practices (24). in the past, many attempts aimed to minimize or prevent the appearance of these wsls throughout or after finishing orthodontic treatment, one of those attempts was the invention of low-viscosity resins that called infiltrants. regarding the current study, this infiltrant represented by icon® which is an innovative product for the micro-invasive treatment of early cariogenic lesions in the proximaland vestibular regions. it can be used to treat caries in a timely manner without drilling. the proximal version of the product is specifically developed for preserving treatment of incipient proximal caries while, the vestibular version is particularly suited for orthodontic patients after braces removal.many in vitro studies chose bovine teeth to test the icon® material but, very little studies dealt with extracted human teeth. human and bovine enamel have similar radio densities.however, their enamel structure may still differ significantly (25). therefore, in the current in vitro study, freshly extracted human premolars had been selected for evaluation of the adhesive systems and their enamel sealing ability against demineralization to provide a comparable environment to human oral cavity during orthodontic treatment and to increase the reliability of the study results. additionally, a lot of teeth were selected to overcome the limited ability of getting more than one specimen with enough sound enamel (thickness and diameter) from each selected tooth. the current study demonstrated that, the application of the conventional adhesives alone or combined with the infiltrant material were more effective than the application of caries infiltrant alone in protection sound enamel from further demineralization. while, there was no significant difference between the infiltrant sealing alone and no sealing at all. the adper™ single bond 2 bonding agent was superior in reduction of enamel demineralization compared to the aforementioned groups (icon®+ unsealed groups) and to the heliobond bonding agent, when applied alone. in addition to that, its protective potential against enamel demineralization was improved when combined with the caries infiltrant. furthermore, this combination was more effective than the combination with the heliobond bonding agent and both of them when applied alone or combined with the infiltrant provided better protection against acidic attack than the unsealed specimens and the infiltrant sealed ones. this might be due to the chemical compositions of the adhesive systems that determine their clinical success (26). the presence of nanofillers in 10% weight of the relatively low viscosity adhesive (adper™ single bond 2) promoted the development of a uniform adhesive film and “stabilized” the hybrid layer (27). their smaller size, improves the adhesive wet-ability (28). while, heliobond represented the unfilled enamel bonding agent as it exhibits potential to penetrate at least early enamel lesions (29,30). and, the high bis-gma content gave the viscose nature of the adhesive and decreases the surface wet ability property, which might result in weakened plugging of the porosities (31-33). however, this property might be participated in lesser sealing ability than the adper ™ single bond 2 bonding agent when applied alone or combined with the infiltrant material. regarding the icon® it was a tegdmabased. the high tegdma content and ethanol in adhesives were shown to increase the capillary penetration and wetting ability of the j bagh college dentistry vol. 28(2), june 2016 the influence of pedodontics, orthodontics and preventive dentistry 123 resins, facilitating better micromechanical unity with the enamel. and that’sone of the important prerequisite in enamel sealing (21). another suggestion that the superficial penetration and surface coating of the adhesive might be more effective in protecting enamel dissolution than the penetration of the infiltrant. furthermore, many studies (21, 31, 34,35) showed that there is a side effect of the high tegdma content in the resin matrix because it leads to increases polymerization shrinkage and stress, resulting in lower physical properties. similarly, more oxygen inhibition and polymerization shrinkage of the low viscosity caries infiltrant were reported to create heterogeneous areas within the penetrated material, resulting in insufficiently filled porosities of the surface. in that respect, icon® with the highest tegdma content among the tested resins was expected to provide better penetration into the enamel with higher contact area. in addition, voids in sealant surface due to the oxygen inhibition and polymerization shrinkage were anticipated. wetting of enamel with icon® prior to heliobond or adper™ single bond 2 primers performed better sealing than all of the single applications, may be due to the incapability of capillary penetration of the two more viscous resins was compensated by icon®, resulting in a highly protective layer against demineralization. it was found (36) that, the infiltration of the demineralized subsurface layer and the sealing of the surface might have an additive effect on the dissolution protection. and the bonding of the adhesive is not impaired on infiltrated enamel surfaces. moreover, covering infiltrated lesions with an adhesive layer might be beneficial in terms of surface properties, as surface roughness of infiltrated lesions is comparatively high (32). very few studies evaluated the effect of icon® on enamel sealing following phosphoric acid etching. one of those studies (20) who compared between the sealing ability of deferent adhesives and icon®, but they selected bovine teeth to test the enamel protection under acidic challenge. their findings were similar to the current study in that the use of low-viscosity caries infiltrant prior to application of the tested conventional adhesives increases their protective effect against demineralization. however, a similar reduction effect on apatite dissolution following hydrochloric acid etching on both sound and demineralized enamel postulated recently (19). in particular, heliobond alone and its combination with icon® performed superior than the infiltrant application alone as found in the current study. but, in contrast to the present findings, combining icon® with heliobond did not provide better protection than heliobond alone. the reason for this declared that, it might be attributed to the extensive etching effect of 120 seconds of hydrochloric acid application, as assumed according to manufacturer kit, which was primarily intended to create a permeable outer layer in the presence of wsls (37). in the present study, the application of caries infiltrant following 38% phosphoric acid etching on sound enamel prior to orthodontic bonding procedure could be an alternative preventive measure against wsls formation, since acid etchant demineralizes the hydroxyapatite crystals of enamel rods, and exposes micro pores on the enamel allowing the adhesive material to interlock and seal the mineralized tissue underneath against acidic challenges resulting from dietary intake of carbohydrates and soft drinks (8,38, 39). according to the present findings, treated specimens with the caries infiltrant system followed by the adhesive exhibited significantly lower ca ion release than the adhesive or the infiltrant alone and which lead to the following conclusion that the combining procedure provided better sealing against acidic attack (19,20). penetration time is another important factor to determine the rate of resin impregnation and plugging the gaps formed by etching. icon® was the only resin with prolonged penetration time, whereas heliobond and adper™ single bond 2 bonding agents were photo-polymerized right after their application on the etched surface. this factor might play another role in increasing the sealing property. clinically, a 180-second application time of icon® might not be easy to obtain, especially on the buccal surfaces of posterior teeth when the patient is in a supine position, because of saliva contamination. therefore, allowing the resin to penetrate as long as possible prior to photo-polymerization should be acknowledged as an improving factor (40). in the present study, the acid attack was applied continuously, mimicking an estimated time period of 9 months with 18 days of continuous ph exposure that resemble to at least 20min/day of acidic challenge. the ph of the acid used was significantly lower than that of the organic acids produced by bacteria. this lower ph was used to increase the quantity of ca ion dissolved to generate detectable amounts in short time periods and to assure the duration of acidic challenge to represent at least the estimated time period (20). on the other hand, it's important to mention that the daily acidic ph attack (frequency and j bagh college dentistry vol. 28(2), june 2016 the influence of pedodontics, orthodontics and preventive dentistry 124 magnitude) depend on many variables, such as frequency of sugar intake, percentage of sugar in the food, and properties of saliva and intraoral flora, which show a great diversity among individuals. however, it should be noticed that the current in vitro studyenvironmentdiffered from the in vivo situation in that there was no protective salivary pellicle and enamel surfaces were in continuous contact with the acidic challenge (19). another important issue declared in another study that, the sealants performing well under these highly demineralizing conditions would also be able to show the same relative protective effects against demineralization caused by weaker acids. one limitation regarding the demineralization cycle might be that, no remineralization by saliva or other regular protective measures such as the use of fluoridecontaining toothpaste has been applied (20). the rationales behind this approach were to increase the precision of the measurement method by eliminating possible ca ion contamination from the toothpaste and avoid possible interactions between measurements. a secondary objective was to simulate the worst case scenario for demineralization without the presence of preventive measures. with these aspects in mind, the endurance of the protective effect provided by icon® + adper™ single bond 2 and icon® + heliobond was anticipated to last throughout the whole course of orthodontic treatment since their seal present the least amount of ca ion release among all groups through the 18 days acidic challenge, representing approximately 9 months in vivo. it's worth to mention that, the data for enamel demineralization found in the current in vitro study have to be carefully transferred to the clinical situation except for the used acid. the pellicle formation on the enamel surface resulting in a diffusion barrier might have an effect on mineral loss within the softened enamel according to the findings of deferent studies (41,42). a series of studies have demonstrated in situ the efficacy of the pellicle in reducing demineralization. thus, it can be speculated that demineralization of softened enamel in vivo is smaller than found in the present in vitro study due to the buffering capacity of saliva that might decrease the demineralization potential of acidic drinks (43, 44). besides the variable tested, other variables must be taken into account in future studies for developing strategies to minimize dental demineralization around the orthodontic brackets. as conclusions 1the low viscosity caries infiltrant did not protect enamel from demineralization when applied alone. 2the low viscosity caries infiltrant (icon®) and the 2 conventional bonding agents (adper™ single bond 2 and heliobond) reduced enamel demineralization when applied alone. 3the conventional bonding agent (adper ™ single bond 2) with its low viscosity and nanofillers contents provided a higher protection compared to the (heliobond) with its higher viscosity 4both conventional bonding agents provided better sealing when combined with the low viscosity infiltrant. 5the combination caries infiltrant with adper™ single bond 2 provided better enamel sealing than the combination with heliobond. references 1. naidu e, stawarczyk b, tawakoli pn, attin r, attin t, wiegand a. shear bond strength of orthodontic resins after caries infiltrant preconditioning. angle orthod 2013; 83 (2): 306–12. 2. mizrahi e. enamel 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acid incorporated with acidulated phosphate fluoride gel etchant effects on bracket bonding. angle orthod 2005; 75: 678–84. 41. barbour me, finke m, parker dm, hughes ja, allen gc, addy m. therelationship between enamel softening and erosion caused by soft drinkat a range of temperatures. j dent 2006; 34: 207–13. 42. hara at, ando m, gonzález-cabezas c, serra mc, zero dt. protectiveeffect of the dental pellicle against erosive challenges in situ. j dent res2006; 85(7): 6126. 43. wiegand a, bliggenstorfer s, magalhães ac, sener b, attin t. impact ofthe in situ formed salivary pellicle on enamel and dentine erosion induced bydifferent acids. acta odontol scand 2008; 66(4): 225–30. j bagh college dentistry vol. 30(4), december 2018 the relation of 28 the relation of maxillary root apices and the maxillary sinus floor among patients with different skeletal patterns in iraqi samples karrar hameed al-sultany, b. d. s (1) iman i. al_sheakli, b. d. s., m. sc. (2) abstract background: understanding the morphological characteristics between the floor of the maxillary sinus and the tips of the maxillary posterior roots is crucial in orthodontics involving diagnosis and treatment planning. the aim of this study was to evaluate the distances from the maxillary posterior root apices to the inferior wall of the maxillary sinus, thickness and density of maxillary sinus floor using cone-beam computed tomography images and the relationships between roots and maxillary sinus according to gonial angle and skeletal pattern. materials and methods: three-dimensional images of each root were checked, and the distances were measured along the true vertical axis from the apex of the root to the sinus floor, and the thickness and density of maxillary sinus floor in 60 patients (30 males, 30 female) aged 18 to 25 years. evaluation of the differences between groups which classified to gonial angle and skeletal pattern which were done according to the comparsion between the mean statistic tests. results: results showed that the density of floor of maxillary sinus at the first molar roots region in class iii were significantly lower than class i and ii, also the distance between the floor of maxillary sinus and both distobuccal and palatal roots of first molar were significantly lower in class i than other classes, while the thickness of maxillary sinus floor at the distobuccal root of first molar were significantly higher in class iii than other classes. in gonial angle difference, the maxillary sinus floor density and distance to the maxillary posterior roots had no significant difference in all groups, while the thickness of maxillary sinus floor at distobuccal and palatal of second molar roots region were significantly higher in large gonial angle than small and normal angles. conclusion: subjects with class i skeletal pattern have small distance between the maxillary sinus floor and the maxillary posterior roots due to the pneumatisation of maxillary sinus causing more difficult and time consuming orthodontic treatment. keywords: distance, thickness, and density of maxillary sinus floor, cone beam computed tomography. (received: 12/9/2018; accepted: 12/11/2018) introduction in adults, the maxillary sinus differs in its projection due to the presence of ‘hillocks’ which are elevations in the surface of sinus floor that occur in 50 % of population when the floor projects among adjacent teeth or roots (1). in these cases, the sinus floor thickness is clearly diminished. when the roots project into the sinus floor many complications occur involving oroantral fistulae or displacement of root into the sinus or cavity that usually happen after extractions of maxillary molars (2). the sinus floor is made by the alveolar process of maxilla and locate about 12.5 mm beneath the floor of the nasal cavity. casually a delicate layer of mucous lining is the only detachment of the roots of teeth from the maxillary sinus (3). the occlusion is influenced by vertical relationship of the upper and lower jaws. the effect is more obvious at the gonial angle when there is difference in the shape of the lower jaw. whenever the gonial angle is high, the mandible prone to increase vertical dimension of the face, and in severe cases causes an anterior open bite. in contrast, the mandible with a low gonial angle prone to decrease vertical dimension of the face. during movement of tooth in orthodontic field and placement of implant, some problems may occur caused by maxillary sinus. intrusion of maxillary posterior teeth into the maxillary sinus may cause tipping and periapical root resorption histologically and even radiographically (4,5). furthermore, the angled placement of microimplants has high risk of destroying the maxillary sinus (6). therefore, problems like sinus perforation, and the resorption of root during the intrusion of molar can be stopped by the recognition about the distance between the roots of maxillary posterior teeth to the floor of maxillary sinus. the thickness of the bone layer of the sinus floor is reduced significantly due to the presence of the roots of the posterior maxillary teeth within the (1) ministry of health, al-kufa, iraq (2) professor, department of orthodontics, college of dentistry, university of baghdad. j bagh college dentistry vol. 30(4), december 2018 the relation of 29 maxillary sinus floor(msf). however, most roots that project into the sinus are normally covered by a delicate cortical layer on histologic sections, and the rates of real perforation are not more than 14% to 28% (7). bone density is defined as the amount of bone tissue in a specific volume of bone (8). many studies illustrate the importance of cone beam computerized tomography cbct scans in the recognition of the topography of the maxillary sinus and its correlation with the tips of the maxillary posterior roots (9-11). the advantages of cbct are low radiation dose and easier technology than the other technologies (12). the aim of this study was to assess the relationships between maxillary posterior roots and maxillary sinus floor according to skeletal pattern, and gonial angle by using cone beam computed tomography images which include measuring the distances between maxillary posterior root apices and inferior wall of maxillary sinus, the cortical bone thickness and density of maxillary sinus floor in the region closest to the root apices and in the furcation areas. materials and methods this study composed of cbct images has been taken in the specialized health centre in alsadr city / 3d radiographic department using kodak 9500 cone beam 3d system machine that made in france (serial number: 420354afxl057) with carestream (cs) 3d imaging software for patients who were attending from december 2017 till may 2018. from the 671 patients that included 436 females and 235 male aged from 15 years to 28 years that was sent for cbct for the diagnosis of impacted third molars, impacted canine, and for orthodontic purposes, 60 iraqi samples (30 males: 10 class i, 10 class ii, 10 class iii; and 30 females: 10 class i, 10 class ii, 10 class iii) ranged between 18-25 years chosen according to the stratified random sampling probability. an informed consent must be made for the subject to be part of the study of different skeletal pattern (class i, class ii, and class iii) that have been determined clinically by palpation with two-fingers method (13). all patients were included except with these exclusion criteria which include: history of previous orthodontic treatment, missing posterior teeth (excluding the third molars), pathologic lesions or abnormalities of the maxillary sinus, radiographic signs of periapical disease, medical history. according to foster (13) extra-orally, the assessment of the skeletal pattern clinically. on the cbct images, the distances from the upper posterior teeth root tips to the inferior wall of the floor of maxillary sinus were measured. the 3-dimensional (3d) measurements were done with carestream (cs) 3d imaging system software (kodak dental imaging 9500 3d, france). positive values were given to the distances that measured when there was no contact between the root and floor of the sinus (figure 1), while negative values were given to the distances measured when the side of the root had contact with the sinus floor or the root penetrated into the maxillary sinus (14,15). figure 1: when the root had no contact with sinus floor, the distance was recorded as a positive value if the root apex is in contact or penetrate the maxillary sinus, the thickness is given value of 0.00 mm (14). measuring msf cortical bone thickness in the region closest to the upper posterior root apices and in the furcation areas (figure 2). figure 2: the cortical thickness of the inferior wall of the maxillary sinus the density of the inferior wall of msf was measured above the maxillary posterior root apices in both sides above the root tip of second premolar, and above the furcation area for both first and second molars, the density of inferior wall of the sinus was measured by placing the mouse on three locations in msf, and obtaining the mean of three readings that had been appeared on the lower right corner of screen (figure 3). j bagh college dentistry vol. 30(4), december 2018 the relation of 30 figure 3: measurement of density the gonial angle can be measured from panoramic view and the location was determined from drawing two lines, a perpendicular line that touches the posterior border of ramus, and a horizontal line touches the mandibular inferior border. in order to impede rotation of the line, two points were determined contact each line. the angle was achieved from the meeting of the horizontal and vertical lines (16,17) (figure 4). okşayan et al. (17) confirmed that the values of gonial angle obtained from lateral cephalometry and orthopantomogram had no significant differences between class i, ii, and iii malocclusion group. after measurements were done 3 groups obtained: large (≥ 132), normal (119-131), and small (≤ 118) gonial angle groups. figure 4: measurement of gonial angle on left and right side results the sample include 60 subjects (30 males, and 30 females) was divided into 3 groups according to gonial angle:14 samples with large (≥ 132), 33 samples with normal (119-131), and 13 samples with small (≤ 118) gonial angle groups. also the sample divided according to skeletal pattern into 20 samples with class i, 20 samples with class ii and 20 samples with class iii groups. descriptive statistics and class difference of the distance between floor of maxillary sinus and root apex of maxillary posterior teeth: the longest distance between the sinus floor and root apices seen in class i with no protrusion at the second premolars (mean value, 0.580), and the more protruded roots into the sinus were the palatal roots of the first molars that found in class i (mean value, -4.075). regarding the sagittal jaw relationship, the study showed a statistical significance at the distobuccal, and palatal roots of the first molars by using anova test, then the difference in distances between class i and iii in both roots found by using tukey’s test (table 1) descriptive statistics and class difference of the cortical bone thickness: the mean thickness of the sinus floor above root apices according to classes. the greatest thickness of inferior wall seen in class iii above the furcation area of the first molar roots (mean value, 1.058), while the lowest thickness found in class i at the mesiobuccal root of the second molar teeth (mean value, 0). the kruskal wallis h test showed statistical significance found at the distobuccal root of the first molar, and by using mann whitney test, the difference in thickness found between class i and iii as in (table 2). j bagh college dentistry vol. 30(4), december 2018 the relation of 31 table 1: distances between the sinus floor and root tips on cbct according to classes roots classes descriptive statistics classes difference anova mean s.d. f-test p-value 5 i 0.533 4.300 0.437 0.647 ii 0.580 4.295 iii 1.305 3.809 6mb i -2.605 2.535 1.307 0.275 ii -2.520 2.739 tukey's hsd iii -1.648 3.443 classes p-value 6db i -3.678 2.843 4.503 0.013* i-ii 0.233 ii -2.558 2.683 i-iii 0.009** iii -1.633 3.558 ii-iii 0.368 6p i -4.075 2.645 5.301 0.006** i-ii 0.083 ii -2.575 3.232 i-iii 0.005** iii -1.858 3.398 ii-iii 0.558 7mb i -3.623 2.361 2.843 0.062 ii -2.598 2.828 iii -2.308 2.564 7db i -2.625 2.516 2.543 0.083 ii -1.785 2.638 iii -1.393 2.328 7p i -1.780 2.006 1.302 0.276 ii -1.210 3.004 iii -0.885 2.423 note: * significant, ** highly significant; 5, second premolar; 6, first molar; 7, second molar; db, distobuccal; mb, mesiobuccal; p, palatal; d.f: 59. table 2: thickness (mm) of the sinus floor above root apices on cbct according to classes roots classes descriptive statistics class difference median mean s.d. kruskal wallis h test p-value 5 i 0.55 0.660 0.716 0.625 0.731 ii 0.55 0.598 0.601 iii 0.9 0.723 0.643 6mb i 0 0.200 0.450 0.893 0.640 ii 0 0.148 0.382 iii 0 0.255 0.503 classes mann-whitney u test p-value 6db i 0 0.045 0.204 6.221 0.045* i-ii 720.5 0.142 ii 0 0.133 0.322 i-iii 639.5 0.013* iii 0 0.233 0.439 ii-iii 718.5 0.262 6p i 0 0.035 0.221 5.147 0.076 ii 0 0.148 0.342 iii 0 0.168 0.387 6 furcation i 0.9 0.933 0.356 0.209 0.901 ii 0.9 0.943 0.298 iii 0.9 1.058 1.009 7mb i 0 0 0 5.396 0.067 ii 0 0.128 0.381 iii 0 0.110 0.304 7db i 0 0.135 0.454 2.085 0.353 ii 0 0.123 0.323 iii 0 0.225 0.486 7p i 0 0.135 0.379 2.573 0.276 ii 0 0.255 0.442 iii 0 0.278 0.514 7 furcation i 0.9 0.940 0.320 1.012 0.603 ii 0.9 0.943 0.311 iii 0.9 1.003 0.290 note: * significant; 5, second premolar; 6, first molar; 7, second molar; db, distobuccal; mb, mesiobuccal; p, palatal. descriptive statistics and class difference of the cortical bone density: the mean density of the sinus floor above root apices according to classes. the highest density of the sinus floor found in class i above the second j bagh college dentistry vol. 30(4), december 2018 the relation of 32 premolar root (mean value, 671.700), while the lowest density found in class iii above the second molar root (mean value, 660.050). the anova test showed statistical significant difference in density found at the first molar root, and by using tukey’s hsd test, the difference in density found between class i and iii, as well as between class ii and iii as in (table 3). table 3: density of the sinus floor above root apices on cbct according to classes roots classes descriptive statistics classes difference anova mean s.d. f-test p-value 5 i 671.700 144.715 0.072 0.931 ii 668.250 120.810 tukey's hsd iii 660.050 155.381 classes p-value 6 i 570.450 91.608 3.206 0.044* i-ii 0.993 ii 567.425 107.997 i-iii 0.047* iii 511.850 143.839 ii-iii 0.049* 7 i 520.950 117.687 1.824 0.166 ii 547.500 110.302 iii 492.475 154.242 note: * significant; 5, second premolar; 6, first molar; 7, second molar; db, distobuccal; mb, mesiobuccal; p, palatal; d.f: 59 descriptive statistics and gonial angle difference of the distance between floor of maxillary sinus and root apex of maxillary posterior teeth: the longest distance between sinus floor and root apices found in normal gonial angle patients with no protrusion at second premolar roots (mean value, 1.172), while the more protruded roots into the sinus were the mesiobuccal roots of second molar that found in small gonial angle patients (mean value, -3.328). in general, no statistical significace difference in distance among different groups of gonial angle as in (table 4). table 4: distances (mm) between root apices and the sinus floor on cbct in different gonial angle groups `roots gonial angle descriptive statistics comparison n mean s.d. f-test p-value 5 low 18 -0.156 5.422 1.052 0.352 normal 82 1.172 3.850 high 20 0.170 3.873 6mb low 18 -2.956 2.963 1.155 0.319 normal 82 -1.983 2.755 high 20 -2.755 3.585 6db low 18 -3.167 3.183 0.634 0.532 normal 82 -2.404 2.908 high 20 -3.030 4.001 6p low 18 -3.022 3.533 0.107 0.898 normal 82 -2.743 2.936 high 20 -3.050 4.105 7mb low 18 -3.328 2.606 0.401 0.671 normal 82 -2.718 2.524 high 20 -2.915 3.136 7db low 18 -3.011 2.060 2.346 0.100 normal 82 -1.851 2.390 high 20 -1.305 3.223 7p low 18 -1.544 2.534 1.267 0.285 normal 82 -1.434 2.227 high 20 -0.480 3.460 note: 5, second premolar; 6, first molar; 7, second molar; db, distobuccal; mb, mesiobuccal; p, palatal; d.f: 59 j bagh college dentistry vol. 30(4), december 2018 the relation of 33 descriptive statistics and gonial angle difference of the cortical bone thickness: the mean thickness (mm) of the sinus floor above root apices according to gonial angle. the greatest thickness of inferior wall seen in large gonial angle at the furcation area of the second molar roots (mean value, 1.085), while the lowest thickness found in normal gonial angle at the mesiobuccal root of the second molar teeth (mean value, 0.065). the kruskal wallis h test showed a significance found at the distobuccal, and palatal root of the second molars. through using mann whitney test, the difference in thickness in the distobuccal root of second molar found between small and large gonial angle, while in the palatal root of second molar, the difference found between normal and large gonial angle as in (table 5). table 5: thickness of the sinus floor above root on cbct according to gonial angle roots ga descriptive statistics class difference median mean s.d. kruskal wallis h test pvalue 5 low 0 0.578 0.753 3.086 0.214 normal 0.9 0.722 0.632 high 0 0.480 0.625 6mb low 0 0.156 0.458 1.067 0.587 normal 0 0.222 0.457 high 0 0.155 0.401 6db low 0 0.228 0.447 1.074 0.584 normal 0 0.124 0.334 high 0 0.105 0.263 6p low 0 0.156 0.368 1.651 0.438 normal 0 0.098 0.313 high 0 0.160 0.352 6 furcation low 1 1.022 0.349 2.161 0.340 normal 0.85 0.985 0.746 high 0.85 0.905 0.258 7mb low 0 0.100 0.424 1.297 0.523 normal 0 0.065 0.243 high 0 0.120 0.305 ga mannwhitney u p-value 7db low 0 0 0 8.105 0.017* lownormal 630 0.086 normal 0 0.166 0.460 lowhigh 117 0.006** high 0 0.285 0.438 normalhigh 668 0.059 7p low 0 0.189 0.403 9.131 0.010* lownormal 703 0.639 normal 0 0.177 0.440 lowhigh 129.5 0.088 high 0.25 0.440 0.482 normalhigh 555.5 0.003** 7 furcation low 0.8 0.922 0.308 2.592 0.274 normal 0.9 0.940 0.282 high 1.05 1.085 0.379 note: * significant, ** highly significant; 5, second premolar; 6, first molar; 7, second molar; db, distobuccal; mb, mesiobuccal; p, palatal. j bagh college dentistry vol. 30(4), december 2018 the relation of 34 descriptive statistics and gonial angle difference of the cortical bone density: the mean density of the sinus floor above root apices according to gonial angle. the highest density of the sinus floor found in normal gonial angle above the second premolar root (mean value, 673.793), while the lowest density found in small gonial angle above the second molar root (mean value, 476.222) show in (table 6). table 6: density of the sinus floor above root apices on cbct according to gonial angle roots gonial angle descriptive statistics comparison n mean s.d. f-test p-value 5 low 18 661.889 163.913 0.430 0.652 normal 82 673.793 142.845 high 20 641.750 103.593 6 low 18 567.333 86.562 0.283 0.754 normal 82 548.805 120.949 high 20 538.750 136.841 7 low 18 476.222 141.452 1.622 0.202 normal 82 522.537 119.271 high 20 550.850 155.020 note: 5, second premolar; 6, first molar; 7, second molar; db, distobuccal; mb, mesiobuccal; p, palatal; d.f: 59 discussion the cbct supplies accurate images with no distortion and overlapping of the nearby structures of the bone that surround root apices, so that cbct has been used in diagnosis and treatment planning widely (15). distance: this study showed a significant difference regarding the sagittal jaw relationship at the distobuccal, and palatal roots of the first molars. all roots of patients with a small gonial angle showed a more protrusion into the sinus than normal and large gonial angle. this was not agreed with ahn and park (15), who revealed that all roots of patients with a large gonial angle showed a significantly closer relationship to the sinus floor or more protrusion of the roots into the sinus than the roots of patients in the normal and small gonial angle groups. during the treatment of open-bite cases, intrusion of the maxillary molar teeth is required which is difficult, because of the close distance between the maxillary posterior root tips and the sinus floor (18). patients that have small gonial angle need light intrusion force in order to decrease resorption of root. clinicians must pay attention when determining the amount and direction of the orthodontic forces during treatment (15). thickness: according to class differences the smallest and greatest thickness of the msf that had been found over the mesiobuccal root of second molar, and over the furcation of first molar apex, respectively. this study agreed with estrela et al (14), in which the smallest thickness had been found over the mesiobuccal root of second molar, but disagreed with yoshmine (19) in both greatest and smallest thickness. harrison (20) reported that the minimum thickness of inferior wall of the maxillary sinus found over the second molar root which was consistent with the present study, while in the study of kwak et al. (21) the cortical thickness over the distobuccal root of the second molar was the thinnest which disagreed with the results of this study obtained from class difference. the differences between these studies were because of the high thickness of msf in this study found over the furcation area of both first and second molars in addition to other reasons as difference in methodology, number of subjects, and ethnicity. a statistical significance had been found in second molar roots in gonial angle differences only. it is interesting to observe that the area of greatest distance between the root tips of maxillary posterior teeth and the msf coincided with the area of the greatest thickness near to the apex (second premolars), and the area of lowest distance steeth and the msf coincided with the lowest thickness near to the apex (second molars). density: the density of sinus floor was measured by placing the mouse on the msf over the roots of second premolar, and above the furcation areas of j bagh college dentistry vol. 30(4), december 2018 the relation of 35 both first and second molar roots, the value of the density appeared on the lower right corner of screen a statistical significance found in density over the furcation of first molar in which subject with class iii had the lowest density of all classes. when observing the gonial angle difference, the greatest density of the floor of maxillary sinus was observed above the root apex of second premolar in subject with normal gonial angle with (mean value, 673.793). no statistical significance had been found in density over all the roots. there are no previous studies conducted the measurement of density of the msf, so that, the results of this study cannot be compared with other studies. conclusion the more protruded root into the sinus floor were the mesiobuccal root apices of the second molars and the palatal root apices of first molars, and the farthest from the floor of sinus were second premolar root apices. the greatest thickness of maxillary sinus floor found over the bifurcation area of both first and second molar roots, while the smallest thickness appeared over the mesiobuccal and distobuccal root apices of second molars. the greatest density of maxillary sinus floor found over the second premolar root apices and the smallest appeared over the furcation of second molar root apices. in class difference, the density of maxillary first molar in class iii were significantly lower than class i and ii, while the distance of both distobuccal and palatal roots of maxillary first molar and the thickness of distobuccal roots of maxillary first molar were significantly higher in class i, and class iii, respectively than other classes. in gonial angle difference, the density and distance had no significant difference in all groups, while the thickness of distobuccal and palatal roots of maxillary second molar were significantly higher in large gonial angle than small and normal angles. references 1. kosumarl w, patanaporn v, jotikasthira d, janhom a. distances from the root apices of posterior teeth to the maxillary sinus and mandibular canal in patients with skeletal open bite: a cone-beam computed tomography study. imaging sci dent 2017 sep; 47(3): 157-64. 2. mattar e, hammad l, faden a, khalil h. relation of maxillary teeth to the maxillary sinus in normal saudi individuals living in riyadh. biosciences, biotechnology research asia 2010; 7(2): 695-700. 3. singh v. textbook of anatomy: head, neck and brain. 2nd ed. elsevier: new delhi; 2014. p. 259-64. 4. wehrbein h, bauer w, schneider b, diedrich p. experimental bodily tooth movement through the bony floor of the nose-a pilot study. fortschr kieferorthop 1990; 51: 271-6. 5. heravi f, bayani s, madani as, radvar m, anbiaee n. intrusion of supra-erupted molars using miniscrews: clinical success and root resorption. am j orthod dentofacial orthop 2011; 139(4): 170-5. 6. laursen mg, melsen b, cattaneo pm. an evaluation of insertion sites for mini-implants: a micro-ct study of human autopsy material. angle orthod 2013; 83: 222-9. 7. wehrbein h, diedrich p. the initial morphological state in the basally pneumatized maxillary sinus–a radiologicalhistological study in man. fortschr kieferorthop 1992; 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1990. p. 76-84. 14. estrela c, nunes ca, guedes oa, alencar ah, estrela cr, silva rg, pécora jd, sousa-neto md. study of anatomical relationship between posterior teeth and maxillary sinus floor in a subpopulation of the brazilian central region using cone-beam computed tomography part 2. braz dent j 2016; 27(1): 9-15. 15. ahn nl, park hs. differences in distances between maxillary posterior root apices and the sinus floor according to skeletal pattern. am j orthod dentofacial orthop 2017; 152(6): 811-9. 16. mahl crw, licks r, fontanella vrc. comparison of morphometric indices obtained from dental panoramic radiography for identifying individuals with osteoporosis/osteopenia. radiol bras. 2008; 41(3): 183-7. 17. okşayan r, aktan am, sökücü o, haştar e, ciftci me. does the panoramic radiography have the j bagh college dentistry vol. 30(4), december 2018 the relation of 36 power to identify the gonial angle in orthodontics? the scientific world journal 2012; 2012:219708. 18. hart tr, cousley rr, fishman ls, tallents rh. dentoskeletal changes following mini-implant molar intrusion in anterior open bite patients. angle orthod 2015; 85: 941-8. 19. yoshimine, s; nishihara, k; nozoe, e; yoshimine, m; nakamura, n. topographic analysis of maxillary premolars and molars and maxillary sinus using cone beam computed tomography. implant dentistry 2012; 21: 528-35. 20. harrison dfn. surgical anatomy of maxillary and ethmoidal sinuses—a reappraisal. laryngoscope 1971: 81: 165864. 21. kwak hh, park hd, yoon hr, kang mk, koh ks, kim hj. topographic anatomy of the inferior wall of the maxillary sinus in koreans. int j oral maxillofac surg 2004; 33: 382-8. المستخلص وتخطيط يص لتي تشمل التشخأهمية بالغة في تقويم األسنان ا هالجذور الخلفية العلوية ل قممإن فهم الخصائص المورفولوجية بين أرضية الجيب الفكي والخلفية: وب الفكية وكثافة أرضية الجي كسمجدار السفلي لجيب الفك العلوي والجذر الخلفي للفك العلوي إلى ال قممكان الهدف من هذه الدراسة هو تقييم المسافات من العالج. زاوية الفك األسفل ونمط الهيكل العظمي. الفك العلوي وفقا لالفك العلوي وجيب رمخروطي والعالقات بين جذوباستخدام صور التصوير المقطعي ال كة الجذر إلى أرضية الجيوب، وسمتم فحص صور ثالثية األبعاد لكل جذر، وتم قياس المسافات على طول المحور الرأسي الحقيقي من قم مواد وطرق البحث: حسبتم إجراء تقييم لالختالفات بين المجموعات التي صنفت سنة. 52و 81أنثى( تتراوح اعمارهم بين 06، رذكو 06مريًضا ) 06الفكي في الجيب أرضيةوكثافة ونمط الهيكل العظمي وفقا للترابط بين االختبارات اإلحصائية المتوسطة. الفك األسفل زاوية البعيدة ي، في حين كانت المسافة في كال الجذوروالثاناألول لنمط الهيكليالثالث أقل بكثير من ا النمط الهيكليكثافة الضرس األول في ان أظهرت النتائج النتائج: الجذور البعيدة الوجنية من الضرس األول أعلى بشكل ملحوظ في األنماط الهيكلية األولى والثانية على طن الفم من األضراس األولى وسمكالوجنية وجذور أعلى با ية الجذور البعيدة الوجنية وجذور أعلى باطن الفم لألضراس الثان في كل المجموعات. بينما سمكحوظ الكثافة والمسافة لم تختلف بشكل مل األخرى. نماطالتوالي من األ .والعادية كانت أعلى بشكل ملحوظ في زاوية الفك األسفل الكبيرة من الزوايا الصغيرة يمكن أن يكون صعباً وبطيئاً بسبب تغلغل الجيوب األنفيةية الجيب الجذور وأرض قمممسافات صغيرة بين في حالة وجود ضراس الفك العلوي ا أدخال االستنتاج: الفكية. abeer.doc j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 1 fracture strength of laminate veneers using different restorative materials and techniques (a comparative in vitro study) abeer gh. abdul khaliq, b.d.s. (1) inas i. al-rawi, b.d.s., m.sc. (2) abstract background: esthetic correction represents one of the clinical conditions that required the use of laminate veneers in premolars region. aim of the study: the purpose of this study was to evaluate the fracture strength of the laminate veneers in maxillary first premolars, fabricated from either composite (direct and indirect techniques) or ceramic cad/cam blocks. materials and methods: fifty sound human maxillary premolar teeth were used in this in vitro study. teeth were divided randomly into one control group and four experimental groups of ten teeth each; group a: restored with direct composite veneer (filtek z250 xt), group b: restored with indirect composite veneers (filtek z250 xt), group c: restored with lithium disilicate ceramic cad/cam blocks (ips e. max cad) and group d: restored with resin nano ceramic cad/cam blocks (lava ultimate restorative). standard preparations were done using ceramic veneer set (komet). indirect laminate veneers were cemented with the relyx veneer cement (3m espe) and all specimens were stored in distilled water at 37°c for 2 weeks. the load was applied on the occlusal part of the veneer at 45˚ to long axis of the tooth using universal testing machine. results were analyzed with one-way anova and lsd tests. specimens were examined by stereomicroscope at a magnification of 20x to evaluate the mode of failure. results: control group showed higher mean of fracture strength with highly significant difference in comparison to the experimental groups (p<0.01). (group a) showed higher mean of fracture strength with statistically significant difference in comparison to (group b and group d). on the other hand the difference between (group a and group c) was statistically highly significant. statistically non-significant difference was found among the three indirectly restored groups. conclusions: all veneers used in this study can be considered as acceptable treatment in the premolars region for patients with normal biting force. direct composite veneer is the most favorable technique in term of fracture strength, while ips e. max cad laminate veneers were least likely to fracture and most likely to completely debond. keywords: laminate veneers, direct composite, indirect composite, lithium disilicate ceramic, resin nano ceramic, fracture strength. (j bagh coll dentistry 2014; 26(4):1-8). الخالصة القشور كسر الغرض من ھذه الدراسة كان لتقییم قوة. واحدة من الحاالت السریریة التي تتطلب استخدام القشور التجمیلیة في المنطقة الضواحك العلویة تجمیليتصحیح الالمثل ی .cad / camالغیر المباشرة و باستخدام تقنیة ال , المباشرة: ة طرق مختلفةمن المواد المركبة أو من قوالب السیرامیك باستخدام ثالث ةمصنوع, التجمیلیة في أسنان الضواحك عشرة أسنان لكل (و أربع مجموعات تجریبیة قیاسیةتم اختیار خمسین سنا من الضواحك العلویة الشخاص بالغین ، تم تقسیم األسنان بشكل عشوائي في خمس مجامیع؛ مجموعة رممت ): ب(المجموعة , (filtek z250 xt, 3m espe)مصنوع من المادة المركبة بصورة مباشرة على االسنان القشور التجمیلیةم رممت باستخدا) :أ(؛ المجموعة )منھم القشور رممت باستخدام): ج(المجموعة )filtek z250 xt, 3m espe( المادة المركبةباستخدام مصنوع بطریقة غیر مباشرة على قالب الحجر القشور التجمیلیة باستخدام قوالب قشور تجمیلیة مصنوعة من رممت باستخدام): د(و المجموعة )ips e. max cad, ivoclar vivadent(قوالب سیرامیك اللیثیوم ثنائي السیلیكات التجمیلیة المصنوعة من cerec inlab( cad / camالتجمیلیة باستخدام تقنیة التم صناعة القشور , )ج و د(في المجموعتین . )lava ultimate restorative, 3m espe(راتنج نانو سیرامیك 4.02, milling system, sirona.(. تم عمل التحضیرات القیاسیة وقد )لكل االسنان في المجامیع التجریبیة باستخدام) داخل المینا(ceramic veneer set) . تعویضات تم تثبیت لمدة اسبوعین ˚37المتصلب باالشعة الضوئیة وخزنھا بالماء المقطر بدرجة حرارة ) relyx veneer cement(المركب الرانتیجي باستخدام السمنت القشور التجمیلیة الغیر مباشرة lsd(نوي واختبار اقل فرق مع) anova(تم تحلیل النتائج احصائیا باستخدام اختبار ). universal testing machine(قبل اجراء فحص قوة الكسر باستخدام جھاز االختبار test .(ولكن القشور التجمیلیة لالسنان الضواحك العلویة یمكن استخدام ,استنتادا الى نتائج ھذه الدراسة الختام في. وقد تم فحص العینات الفاشلة تحت المجھر لتحدید نمط الفشل ھو األسلوب األكثر مالءمة من حیث قوة لیة المصنوعة من المركب الراتنیجي بالطریقة المباشرةالقشور التجمی. ینبغي تقییمھبعنایة االطباقیة أداء الوظیفة أ فياستخدامھ للمریض مع خط .الكسر في الضواحك introduction esthetic or cosmetic dentistry has become one of the main areas of dental practice emphasis and growth for several years. recently, the main reason for applying restorative dental materials is not only to restore dental tissues lost because of caries or trauma, but also to correct the form and color of teeth for social acceptance (1). as smile design not only means designing teeth, but also creating a smile that truly complements the patient’s face and personality. following this philosophy, recreating a smile need not be limited (1) master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) professor. department of conservative dentistry, college of dentistry, university of baghdad. to the anterior teeth, but may extend to include the posterior teeth (2). crown preparation involves significant removal of tooth structure and may cause pulpal irritation and irreversible pulpitis. while laminate veneers are more conservative than crowns and maintain the biomechanics of the original tooth with a similar stress distribution and a success rate of approximately 93% over 15 years of clinical use (3,4). according to literature the most frequent failure modes associated with laminate veneers are fracture and debonding. fractures of laminate veneers represented 67% of the total failures of such restorations over a period of 15 years of clinical performance (3,4). j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 2 little information is available in the literature on the survival rates of different laminate materials. there was no evidence as to whether indirect laminates are better than direct ones and whether it suitable to withstand biting force in premolars region. materials and methods fifty sound human maxillary first premolars extracted for orthodontic treatment with comparable dimensions were selected for this invitro study. the occluso-cervical and mesio-distal dimensions were measured. to determine that the enamel was free from cracks, all teeth were visually examined under blue light transillumination. teeth were cleaned by scaling and stored in distilled water at room temperature (5, 6). teeth were then randomly divided into five groups of 10 specimens each: • control group: intact teeth. • group a: restored with direct composite veneers\filtek z250 xt. • group b: restored with indirect composite veneers\filtek z250 xt. • group c: restored with cad/cam veneers\ips e.max cad blocks. • group d: restored with cad/cam veneers\lava ultimate restorative blocks. the teeth were mounted individually in specially designed, locally-manufactured rubber mold (30 mm height × 30 mm diameter) with cold cure acrylic (vertex, netherlands) with the long axis of the tooth parallel to center of the mold. each tooth was suspended in the middle of the mold using a ney surveyor (bego, germany) to ensure vertical positioning of the tooth inside the mold. all specimens were embedded up to 2 mm apical to the cej to simulate the natural biologic width (7) as seen in (fig.1). figure 1: tooth mounted in acrylic block 2 mm apical to cej. primary impression and primary model was prepared for all experimental teeth which was used to fabricate copyplast template for group a and group b, while for group c and group d, the primary model was used to take a biocopy for creating laminate veneers of the original size and shape of the teeth (8,9). a copyplast template was fabricated for each tooth in group a and group b using 0.5 mm thick vacuum pressed polyethylene plastic template in a vacuum forming machine. then a sectional index was produced using a putty polyvinylsiloxane material (zhermack, italy) before the preparation to evaluate the consistency of tooth reduction. before starting, the outline of the preparation was painted with a waterproof color marker. magnification loupes (2.5x) were used during the whole tooth preparation procedure which was done under constant water irrigation. standardized preparations were done for all the teeth using ceramic veneer system preparation bur set (cvs for porcelain veneers, komet, germany). the facial reduction was 0.4 mm at the cervical third and 0.5 mm at the middle and oclussal thirds (10). the preparation ended 1 mm occlusal to the cement-enamel junction (5,11). the buccal cusp was reduced 1.5 mm occluso-cervically and 1 mm bucco-palatally placing the margin away from the occlusal contact and grooves (12,13). proximally, the preparation was extended without destroying the contact area which represents the area of highest contour. where possible, all the preparations were confined within the enamel. however, the exposure of some dentin often occurred, especially in the cervical tooth region. this not only produces a highly predictable and stable bond, but also the enamel provides stiffness to the tooth. in the absence of surface enamel, the tooth may be more prone to flexure during loading which may cause fatigue and eventual fracture of laminate (3,14). after that, all the line angles were rounded with white stone using slow speed handpiece. hand chisel (hu-friedy) was used for margin finishing. finally the preparation was checked with the previously prepared silicone index from the lateral view to ensure that the necessary reduction of the facial surface was done properly (6,15)as shown in (fig. 2). j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 3 figure 2: silicone index to ensure consistent facial and occlusal reduction. final impression was taken for all teeth in group b, c and d with addition silicone impression material using two-stage putty-wash technique. each impression was boxed using sheet wax and poured with type iii dental stone (zhermack, italy). after setting, the die was trimmed and numbered according to its respective tooth. group a: restored with direct composite veneers using filtek z250 xt. the prepared tooth was cleaned with fluoride-free pumice using polishing cup and then etched with 35% phosphoric acid (scotchbond™ etchant, 3m espe, usa) for 15 seconds, rinse for 10 seconds and air dried gently for 5 seconds according to manufacturer’s instructions. immediately after drying, two consecutive coats of adhesive (adper™ scotchbond™ 1 xt, 3m espe, usa) were applied with gentle agitation for 15 seconds using a fully saturated brush, the adhesive then was gently air thin for 5 seconds to evaporate solvent and light-cure with led curing light (woodpecker, china) for 10 seconds according to manufacturer’s instructions. the buccal third (bucco-palataly) of the template was then packed with the composite material and the template was seated on the tooth. the excess composite extruded from the hole was removed and the composite was light-cured using led curing light positioned closed to the tooth for 20 seconds according to manufacturer’s instructions. after removing the template, the veneer was finished and polished using optidiscs finishing and polishing system (kerr, switzerland). group b: retored with indirect composite veneers with filtek z250 xt. after fabrication of the stone die, two coat of die spacer was applied with a brush on the prepared part of the die (1 mm) away from the margins (5). standard thickness of the laminates in the original form of the teeth was achieved using the previously prepared copyplast template in the same manner used for direct composite and light cured for 10 seconds. after that, the veneer was removed from the tooth and light cured for another 10 second according to manufacturer’s instructions. the thickness was checked with measuring device. finally the veneer was placed on the prepared tooth and the margins were checked with dental explorer. after optimal fitness had been verified, the veneers were finished and polished with optidiscs and prepared for cementation (fig. 3). figure 3: checking the fitness of the indirect composite veneer on the tooth. group c and group d: restored with cad/cam veneers (ips e.max cad and lava ultimate restorative blocks respectively). the veneers were completed in four phases. firstly, in “administration” phase, veneer was selected as restoration type from single restoration options. maxillary first premolar tooth was selected as abutment tooth, “bigeneric copy” was chosen as the mode of design and the type of materials and manufacture (ips e. max cad or lava ultimate restorative) was defined. secondly, in the “scan” phase three dimensional images were obtained by scanning the models by ineos blue scanner (sirona dental systems, bensheim, germany). biocopy was taken first by scanning the primary model from buccal, mesial, and distal side to obtain three image for each model, then the scanning of the die was accomplished by rotational scan in which the die was fixed on the rotation mouse at 60˚, which automatically takes 8 snap shot for each die model, then only 3 image were chosen. after that, both scans were automatically analyzed and correlated with each other by the system which allows alignment of the 3-dimensional image of the primary models on top of the 3-dimensional image of dies correctly. the designing of veneer was then started in “model” phase with preparation trimming by hiding image regions outside the preparation, the margin of preparation was automatically detected by the system (fig. 4) and in copyline section, and the area to be copied from the biocopy was delineated in order to design a laminate veneer identical to the original tooth form. j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 4 figure 4: automatic preparation margin detection. after that, other veneer parameter was defined in “design” phase such as minimum veneer thickness (0.4 mm) and spacer (8 μm) which were determined according to manufacturer’s instructions. the milling process of the samples started as follows: a) the selected ceramic block (ips e.max cad or lava ultimate restorative) was inserted in the spindle of the milling chamber of the cerec in-lab machine and fastened with the set screw. b) the milling process was fully automated without any interference with the two diamond cutting instrument acting together simultaneously in the shaping process, with copious water cooling sprayed from both directions. c) after completion of the milling process, the restoration was separated automatically. according to manufacturer’s instructions, the lava ultimate restorative veneers didn’t require any further firing or glazing, while the ips e-max cad ceramic laminates, appear to be in their pre crystallized format after milling where they have the bluish-gray color. they were fired in a short 30 minutes firing cycle in a ceramic sintering furnace (ivoclar/vivadent/technical, germany) according to manufacturer’s instructions. the internal bonding surface of indirect veneers was treated according to their manufacturers’ instructions as follow: a) indirect composite veneers (group b) were sandblasted with 50μm al2o3 particles for 10 second at maximum pressure of 2 bars (30 psi), and then cleaned by ultrasonic cleaner with distilled water for 5 minutes. b) ips e.max cad veneers (group c) was acid etch with 5 % hydrofluoric acid gel (ips ceramic refill) for 20 seconds washed and thoroughly with air/water spray for 30 seconds according to the manufacturer instructions (7). the veneers then silanated with relyx ceramic primer (3m espe, usa) which was brushed onto the internal surface of the veneer and lightly air-dried for 5 seconds to evaporate the solvent. d) lava ultimate cad/cam restorative veneers (group d) were cleaned in an ultrasonic cleaner with distilled water for 5 minute using distilled water. then sandblasting was done following the same protocol used with indirect composite. the veneers were then cleaned with alcohol and dried with air according to manufacturers’ instructions. the relyx ceramic primer was applied in the same manner as described previously for ips e.max cad. all indirect veneers were cemented by the 3m relyx veneer cement using two-steps etch and rinse technique and the translucent shade cement. for easier handling, the veneers were held by optrastick during cementation procedure. the same procedure was followed for all indirect veneer according to the manufacturer’s instructions of the cement. the veneers were then stored in distilled water at 37˚ for 2 weeks before testing. the fracture strength test performed using a universal testing machine (laryee universal testing machine, china). load was applied at a crosshead speed 0.5 mm/min (5) with a customized plunger (steel rod with a flat end 3.6 mm diameter) attached to the upper movable compartment of the machine (7), placed at the occlusal part of the laminate veneer (16). the load was applied at 45˚ to the long axis of the tooth (17). this orientation was standardized with a specially designed, locally manufactured, mounting jig (fig. 5). the maximum load to produce fracture for each sample was automatically recorded in newton (n) using computer software. modes of failure were assessed with stereomicroscope at 20x magnification. the results of this study were analyzed with one-way anova and lsd test. figure 5: load application at 45˚ to the long axis of the tooth. results the means and standard deviations of fracture strength were calculated for each group shown in (table 1). j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 5 table 1: descriptive statistics: mean and standard deviation of fracture strength in newton. groups no. mean sd control 10 420.80 53.549 group a 10 336.80 71.194 group b 10 272.80 35.279 group c 10 226.60 60.588 group d 10 271.80 68.796 the results of this study showed that the highest mean of fracture strength was recorded for the control group (420 n), followed by group a (336.8 n), next group b and group d (272.8 and 271.8 n) respectively, while the lowest mean value of fracture strength was recorded by group c as shown in (fig. 6). anova test revealed statistically highly significant differences among the five groups (table 2). table 2: comparison among the groups using one-way anova test source of variance sum of squares df mean square f sig. between groups 227036.32 4 56759.08 16.139 .000 within groups 158260.80 45 3516.907 table 3: multiple comparisons lsd test groups mean difference sig. control group group a 84.00* .003 group b 148.00* .000 group c 194.20* .000 group d 149.00* .000 group a group b 64.00* .020 group c 110.20* .000 group d 65.00* .018 group b group c 46.20 .088 group d 1.00 .970 group c group d -45.20 .095 *. the mean difference is significant at the 0.05 level. the results of lsd test showed that there were statistically highly significant differences (p < 0.01) in the fracture strength of control group as compared with the all experimental groups (a, b, c and d), also statistically highly significant difference was found between group a and group. additionally, there were statistically significant differences in fracture strength between group a and group b and between group a and group d. on the other hand, no statistically significant differences were found among all indirect veneers groups (group b, c and d). discussion according to the results of this study, the control group presented the highest mean fracture load among the groups, these results come in agreement with the results of prasanth (18) and akoğlu and gemalmaz (5), and the differences between control group and other test groups were found to be statistically highly significant. the next higher mean of fracture strength was recorded by group a, this may be due to the formation of a continuum between tooth surfaces, adhesive, and restorative material, which is accomplished by the demineralization and penetration of resin in enamel and the formation of a unique body between restoration and tooth structure (19). in comparison between the mean of the directly restored group and the indirectly restored groups, the mean of fracture strength of direct composite veneer (group a) was statistically significantly higher than that of groups restored with indirect technique (groups b, c, and d), this could be explained by the elimination of cement layer in the direct composite veneer as cement is considered the weak restorative link (20). composite luting materials are vulnerable to water sorption, polymerization shrinkage, and microleakage (14). this finding comes in agreement with duzyol et al. (21) results. in spite of the fact that the same composite resin material was used for direct and indirect laminate veneers fabrication and exhibits similar flexure strength, flexure modulus and hardness, the fracture strength of group b was found to be significantly lower than that of group a. this result may be attributed to the effect of surface conditioning (sandblasting and ultrasonic cleaning) of the indirect composite veneer prior to cementation in addition to the presence of the weak cement interface. this result comes in agreement with borba et al. (22) and duzyol et al.(21) who found statistically highly significant different between fracture strength of directly and indirectly fabricated composite veneers. while disagree with gresnigt and özcan(11)who found that direct and indirect resin composite laminate veneers showed comparable mean of fracture strength, owing to the difference in materials used for the construction of direct and indirect composite veneers. according to lsd test there was a statistically highly significant difference between group a and group c, as composite materials have shown a greater capacity to absorb compressive loading forces and reduce the impact forces by 57% more than porcelain (23). however, this result disagree with the results batalocco et al. (9) study in which j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 6 they found that there was no significant difference in fracture strength between composite resin veneers and porcelain veneers. this may be due to the difference in the test condition as they performed testing of the restorative materials under the wet condition. on the other hand, the statistically significant difference found between groups a and d may be, in addition to the weak cement interface, due to the method of construction of lava ultimate restorative blocks as it was processed multiple hours in a special heat treatment process which result in a high degree of conversion and this in turn causes improvement in mechanical strength and hardness. however, this procedure increases the cross-linking of the resin to a high extent but consequently leads to a more brittle material with higher flexural strength of (204 mpa) (24). these results disagree with the results of duzyol et al. (21) who found statistically non-significant difference in fracture strength between lava ultimate restorative and direct composite veneers, which may be attributed to different luting cement (dual-cured luting cement duolink universal, bisco) used for cementation of lava ultimate restoratives veneers. moreover, statistically non-significant difference in the mean of fracture strength obtained form group b and group d that have been recorded approximate means of fracture strength of (272.8 n) and (271.8 n) respectively. this could be attributed to the comparable properties of both materials; filtek z250 xt has compressive strength of (380 mpa) and modulus of elasticity of (12.5 gpa), lava ultimate restorative has a compressive strength of (383 mpa) and a modulus of elasticity of (12.7 gpa). this may be explained by the fact that both materials have same percentage of filler loading about (80% wt), which composed mainly of zirconia/silica nanoclusters. also both materials were subjected to comparable surface treatments. this is come in agreement with duzyol et al.(21). the lowest mean of fracture strength presented by group c (226.6 n), this could be attributed to the combination of high strength (360 mpa) combined with high modulus of elasticity (95.5 gpa) (25) which translates to lower resiliency, which is the capability of the material to absorb energy when it is deformed (26). so this might result in load transition to the weak link of the restoration (the cement layer) (4). this result agrees with khatib et al. (7) who recorded a mean of fracture strength (255 n) for ips e.max cad. the fracture strength values obtained for teeth restored with indirect composite and nano resin ceramic veneers confirm the theory that polymer materials have greater capacity to distribute tensions in a more homogeneous way than ceramics as they present greater resiliency resulting in a larger capacity to suffer plastic deformations, preserving the adhesive interface. another important aspect that explains this point is the synergism of behavior among the indirect resins, resin cement and adhesive system, which have similar compositions and high bond capacity among themselves (27). however, according to lsd test, the difference in fracture strength between all indirect groups (group c, b and d) was statically nonsignificant, which comes in agreement with the results of carneiro et al. (28) who found comparable fracture strength for both ips e.max cad and lava ultimate restorative. this is also come in agreement with duzyol et al. (21) who found non-significant difference between indirect composite and lava ultimate restorative veneers. however, this finding disagrees with the results of de goes (29) who compared the fracture strength of disc shape specimens of 0.5 mm thickness fabricated from ips e.max cad and lava ultimate restorative and conventional composite materials and found that lithium disilicate glassceramic for cad demonstrated the highest strength. failure analysis of the fractured laminates in this study showed mainly fracture of the veneer restoration followed by veneers debonding which coincides with the finding of gresnigt and ozcan (11). clinically, these types of failure could be considered more favorable, since it allows intraoral repair options. fracture of veneers was observed in 100% in groups (a, b, d) as the dominant type of fracture. fracture of the laminate veneer was attributed first to the good adhesion of the laminate veneer to either dental tissue or the cement layer (8). another explanation for this could be the relatively lower flexure strength of the materials, based on the fact that if the flexural strength of the veneer cannot protect the tooth, the veneer will fracture before the loading force is transferred to the tooth (14). on the other hand a lower modulus of elasticity correlates to increased deformation under load, suggesting that lava ultimate restorative and filtek z250xt were more likely to absorb the stress than silica based-ceramics (30). debonding of laminate veneers, on the other hand, showed the weak link between the cement/tooth and the laminate veneer and was observed only in ips e.max cad group with 100 % as the only mode of failure. this could be attributed to the lower resiliency of the material which results in high stresses that develop directly j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 7 below the loaded area at the cement interface. interfacial stresses arise because ceramic has a higher elastic modulus than the tooth or cement (14). a higher incidence of bond failure was observed at cement/veneer interface 70% and the remaining 30% of debonding was at tooth/cement interface due to compromised bonding between the resin cement and the intaglio surface of the veneers. in other words most failures are caused by complete debonding at the porcelain/cement interface. even though the highest bond strength for lithium disilicate ips e. max cad is achieved when it was hydrofluoric acid-etched after being machined, compared to being machined only or machined/grit blasted. however, hydrofluoric acid-etched silica-based ceramic has a highly retentive high-energy surface which is highly susceptible to contamination (31). this makes the pretreated ceramic bonds negatively influenced by external factors such as water absorption, changes in temperature, and contamination by latex gloves, saliva, and the fit checker (30). also it has been found that hydrofluoric etching generates a significant amount of crystalline debris that contaminates the porcelain surface and may reduce bond strength by 50% and this may be considered as another explanation for the lower bond strength at cement/ veneer interface (32). the results of the current study exhibited mean values for the experimental groups ranging between (226.6 n) for ips e.max cad veneers and (336.8 n) for the direct composite veneers, while the natural tooth biting force was about (250 n) for the first premolar as a single tooth bite force measured in healthy young adults (33). on the other hand others investigators assumed (170 n) as the chewing force for premolars and 500 n was assumed as the heavy parafunctional load of bruxism and traumatic occlusion (34). this indicates that both techniques direct and indirect and all the three different materials used for fabrication of laminate veneers could be considered strong enough to withstand normal biting forces in the premolar region, but for patients with parafunctional habit other treatment modality should be considered. further investigation is required to study bonding of ips e.max cad veneers, which were least likely to fracture but the most likely to completely debond. these results may provide the clinicians a guideline for the selection of restorative treatment modality when they provide an esthetic veneer restoration for premolar. it appeared that the mechanical strength of the material would not be a determining factor, but other factors such as predictable and durable esthetics, reliability of the bonding and\or the cost of treatment could be determining factors to select the specific restoration. references 1. gresnigt m. clinical and laboratory evaluation of laminate veneers, chapter one: introduction. thesis, department of fixed and removable prosthodontics, university of groningen, netherlands, 2011. 2. mistry s. principle of smile design. j cosmetic dentistry 2012; 28(2): 116-24. 3. friedman mj. a 15-year review of porcelain veneer failure: a clinician’s observations. compendium of continuing education in dentistry 1998; 19(6): 625-8. 4. alghazzawi tf1, lemons j, liu pr, essig me, janowski gm. the failure load of cad/cam generated zirconia and glass-ceramic laminate veneers with different preparation designs. j prosthet dent 2012; 108(6): 386-93. 5. akoğlu b, gemalmaz d. fracture resistance of ceramic veneers with different preparation designs. j prostho dent 2011; 20(5): 380-4. 6. turkaslan s, tezvergil-mutluay a, bagis b, vallittu pk, lassila lv. effect of fiber-reinforced composites on the failure load and failure mode of composite veneers. dent mater j 2009; 28(5): 530-6. 7. khatib d, katamish h, ibrahim as. fracture load of two cad/cam ceramic veneers with different preparation designs. cairo dent j 2009; 25(3): 425-32. 8. özcan m, meşe a. effect of ultrasonic versus manual cementation on the fracture strength of resin composite laminates. oper dent 2009; 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40(3): 202-9. 15. d'arcangelo c, de angelis f, vadini m, d'amario m. clinical evaluation on porcelain laminate veneers bonded with light-cured composite: results up to 7 years. clin oral investig 2012; 16(4):1071-9. 16. gresnigt m, özcan m, kalk w, galhano g. effect of static and cyclic loading on ceramic laminate veneers adhered to teeth with and without aged composite restorations. j adhes dent 2011; 13(6): 569-77. 17. archangelo cm, rocha ep, anchieta rb, martin m, freitas ac, ko c, cattaneo pm. influence of buccal j bagh college dentistry vol. 26(4), december 2014 fracture strength of restorative dentistry 8 cusp reduction when using porcelain laminate veneers in premolars. a comparative study using 3-d finite element analysis. j prosthod res 2011; 55: 221-7. 18. prasanth v, harshakumar k, lylajam s, chandrasekharan nair k1, sreelal t. relation between fracture load and tooth preparation of ceramic veneers an in vitro study. health sci 2013; 2(3):1-11. 19. rezvani mb, basir mm, mollaverdi f, moradi a, sobout a. comparison of the effect of direct and indirect composite resin restorations on the fracture resistance of maxillary premolars: an in vitro study. j dent school 2012; 29(5): 299-305. 20. gresnigt m, özcan m, kalk w. randomized controlled split-mouth clinical trial of direct laminate veneers with two micro-hybrid resin composites. j dentistry 2012; 40: 766-75. 21. duzyol m, seven n, akgul n. fracture resistance of direct and indirect laminate veneers. international adhesive dentistry–iad: beauty and science, 2013. 22. borba m, della bona a, cecchetti d. flexural strength and hardness of direct and indirect composites. braz oral res 2009; 23(1): 5-10. 23. ereifej n, silikas n, watts dc. edge strength of indirect restorative materials. j dent 2009; 37: 799806. 24. 3m espe. lava™ ultimate cad/cam restorative. technical product profile; 2011. 25. ivoclar vivadent. ips e.max cad scientific documentation, lichtenstein; 2011. 26. sakaguchi rl, powers jm. craig’s restorative dental materials, thirteenth edition, chapter four: fundamental of materials science. usa: mosby, inc.\ elsevier inc, 2012:33-83. 27. soares cj, martins lr, pfeifer jm, giannini m. fracture resistance of teeth restored with indirectcomposite and ceramic inlay systems. quintessence int 2004; 35(4): 281-6. 28. carneiro lc,varpavaara p, heikinheimo t, lassila l, muhimbili. evaluation of onlay fracture load; resin nano ceramic and ips e.max. j dent res 2012; 91 (spec iss c). 29. de goes mf. biaxial strength/weibull moduli of nanocomposite and glass-ceramic cad/cam materials. international association for dental research (iadr), 2013. 30. magne p, paranhos mp, burnett lh jr, magne m, belser uc. fatigue resistance and failure mode of novel-design anterior single-tooth implant restorations: influence of material selection for type iii veneers bonded to zirconia abutments. clin oral impl res 2011; 22 (2): 195-200. 31. pollington s, fabianelli a, noort rv. microtensile bond strength of resin cement to a novel fluorcanasite glass-ceramic following different surface treatments. dent mater 2010; 26: 864-72. 32. mizrahi b. porcelain veneers: techniques and precautions. international dentistry sa 2007; 9(6):616. 33. ferrario vf, sforza c, serrao g, dellavia c, tartaglia gm. single tooth bite forces in healthy young adults. j oral rehabil 2004; 31(1):18-22. 34. nakamura t, imanishi a, kashima h, ohyama t, ishigaki s. stress analysis of metal-free polymer crowns using the three-dimensional finite element method. int j prosthodont 2001; 14: 401-5. j bagh college dentistry vol. 26(1), march 2014 salivary gland oral diagnosis 88 salivary gland tumors: a review of 171 cases, with particular reference to histological types, site, age and gender distribution faris i. al-khiro, m.b.ch.b., f.i.c.m.s., e.b.p. (1) abstract background: salivary tumors are uncommon, being of low incidence worldwide. this study aimed to assess cases collected in this series of salivary gland tumors in regard to histopathological typing, in relation to age, site and gender. materials and methods: this is a retrospective study; cases were collected from public and private laboratories. a total number of 171 cases were collected. the slides were reviewed and reclassified for histopathological typing according to who classification 2005. results: benign tumors were more common than malignant tumors. the most common histological type was benign mixed tumor, followed by warthin’s tumor. the most common malignant tumor was adenoid cystic carcinoma. one hundred twenty three cases out of 171 cases developed in the parotid, the most common site for salivary tumors, with a low risk for malignancy, while minor salivary glands show higher risk for malignancy. salivary tumors developed in females more than males with a ration 1.4:1, the peak incidence in the sixth and seventh decades for both benign and malignant tumors. there was no significant difference between right and left tumors, bilateral tumors were uncommon. conclusions: the results of this study reveal similarity to the findings of other studies on salivary tumors done in iraq and the neighboring countries. keywords: salivary gland tumors. (j bagh coll dentistry 2014; 26(1):88-91). introduction salivary gland tumors are uncommon, accounting for about 3-6% of head and neck neoplasms1. most of tumors develop in major salivary glands, so 43-90% occurs in the parotid gland, 8-19.5% in submandibular gland, uncommon in sublingual glands and only 14-22% occurs in minor salivary glands 2. salivary tumors show marked variation and morphological overlap, which resulted in repeated new classifications 3-6, the first classification was done by foote et al in 19543. currently, the most widely used classification is the world health organization (who) classification, which primarily stresses distinction into benign and malignant tumors7. in most studies, salivary tumors are generally more common in females in their 3rd to 5th decades of life8,9 . they are rare in pediatric age group, the most common tumors seen are benign mixed tumors, but the ratio of malignancy is higher than in adults10. most of salivary gland tumors are unilateral, with no significant difference between right and left. bilateral tumors are uncommonly seen, and occur mostly with warthin’s tumors 11. benign salivary gland tumors are more common than malignant tumors; the most common type is the benign mixed tumor or pleomorphic adenoma. these vary greatly in morphologic features, composed basically of epithelial and mesenchymal elements, they have a potential to recur 12, because they are partially (1) pathology department, al yarmouk teaching hospital. encapsulated and difficult to excise completely in many cases. malignant transformation is uncommon. however, it has been reported to occur more in submandibular gland tumors13,14. warthin’s tumor, also called cystadenoma lymphomatosum papilliferum, seen almost exclusively in major glands 15. the tumor has a higher risk for bilateralality16, and it's incidence is higher in smokers17.other benign salivary adenomas are collectively much less common; the least uncommon are canalicular adenomas and basal cell adenomas. it has been reported in most studies that mucoepidermoid carcinomas are the most common malignant tumor in the parotid gland18. acinic cell carcinomas and adenocarcinoma are less common, while adenoidcystic carcinomas are the most common malignancy in the minor salivary glands11. malignant lymphoma can be seen as part of a systemic disease, or more commonly a primary neoplasm. most of the cases are b cell type, often seen on a background of miculisz disease or other autoimmune diseases 19. immunohistochemistry can be useful as an ancillary aid in diagnosis of specific histologic types of salivary gland tumors 20,21, particularly in uncommon adenomas and in malignant tumors: these tumors are uncommon in general pathology practice, and because these tumors frequently show morphological overlap. therefore, this retrospective study is aimed to assess collected series of cases of salivary gland tumors, in regard to histological typing, site, age and gender. j bagh college dentistry vol. 26(1), march 2014 salivary gland oral diagnosis 89 materials and methods cases were collected from private and public laboratories. the total number of cases collected was 171 cases. for all cases, the slides were collected and reviewed. the cases were histologically classified according to the who classification7 . the following parameters were evaluated and analyzed: age incidence and distribution versus histological type, histological type versus various salivary gland anatomical sites, and the reverse relationship of anatomical sites versus histological typing laterality. ultimately, results were compared to other national and abroad studies. results the total number of collected cases was 171. benign tumors made up 141 cases, or 82.5% of total number of cases, while malignant cases were 30 cases, constituted 17.5 % of cases. age incidence is shown in (table 1), where age was higher in females over males with a ratio of 1.4:1, both benign and malignant tumors, with a ratio of 1.3:1 and 2.3:1 respectively. the peak incidence for benign tumors was in the sixth decade and for malignant tumors in the seventh decades for both males and females. no case in this series developed in the pediatric age group, age range was 15-91 years. there was no significant difference in the incidence of right versus left salivary gland tumors. two cases were bilateral, both were warthin’s tumor. in regard to benign tumors, benign mixed tumor was the most common tumor type, with 102 cases, making up 59.7% of cases, the mean age was 49.4 years (table 2).age range was between 15 and 90 years. eighty one cases developed in the parotid, 13 in the submandibular and 8 in minor salivary glands. warthin’s tumor was the second most common benign salivary tumor, with 27 cases (15.8%), mean age 67.2 years, age range 49-91. all other benign tumor types were 12 cases (7%), the mean age 64.8 years and age range 44-77. seven cases were in the parotid gland and 5 in minor salivary glands. the most common was basal cell adenoma with 8 cases; all were females, with a mean age of 66 years. five cases were in the parotid and 3 in the minor salivary glands. other benign tumors included 3 cases of oncocytoma and 1 case of canalicular adenoma. the most common malignant tumor was adenoidcystic carcinoma 7 cases (table 3), 5 of them were in the minor salivary glands, while 2 cases were submandibular. no cases were seen in the parotid gland. five cases of acinic cell carcinoma were seen, 4 of them in the parotid. also five cases of pleomorphic low grade adenocarcinoma, all were in the minor salivary glands. three cases of mucoepidermoid carcinoma and 4 cases of malignant lymphoma were seen. other types of malignancy collectively accounted for 6 cases. the parotid gland was the most common site of salivary tumors, with 123 cases (table 4). however, only 9 cases (7%) in this series were malignant. according to table-4, benign tumors were 114 cases, or 93%, the most common type was pleomorphic adenoma, 81 cases (66%), followed by warthin’s tumor 26 cases (21%). other benign tumors were rare. submandibular gland tumors were 20 cases in this series, 13 benign, all pleomorphic adenomas, and 7 malignant, so malignant risks is higher than the parotid gland. sublingual gland tumors were rare, 2 cases were diagnosed, both malignant. while minor salivary gland tumors were 26 cases, malignancy 12 cases, most commonly adenoidcystic carcinoma and pleomorphic low grade adenocarcinoma. table 1: age and gender distribution and percentage of salivary gland neoplasm age(years) benign malignant males females total males females total 11-20 3 4 7(5.0%) 0 0 0 21-30 5 4 9(6.4%) 0 2 2(6.7%) 31-40 7 7 14(9.9%) 0 1 1(3.3%) 41-50 10 11 21(14.9%) 2 1 3(10%) 51-60 14 20 34(24.1%) 3 5 8(26.7%) 61-70 11 19 30(21.3%) 4 7 11(36.6%) 71-80 9 10 19(13.4%) 0 5 5(16.7%) 81-90 3 3 6(4.3%) 0 0 0(0%) 91-100 0 1 1(0.7%) 0 0 0(0%) total 62(44.0%) 79(56.0%) 141(100%) 9(30%) 21(70%) 30(100%) j bagh college dentistry vol. 26(1), march 2014 salivary gland oral diagnosis 90 table 2: tumor types mean age, standard deviation and age range, with anatomical site distribution sal. gland anatomical site age range mean age±s.d. number tumor types minor sublingual submand parotid 81 13 -- 8 15-90 49.4±17.3 102(59.7%) pl.ad. 26 -- -- 1 49-91 67.2±7.7 27(15.8%) warthin's 7 -- -- 5 44-77 64.8±8.4 12 (7.0%) benign 9 7 2 12 24-80 59.9±13.2 30(17.5%) malignant 123 20 2 26 15-91 55.1±14.4 171(100%) total table 3: malignant salivary gland tumors: histological types vs. age, sex and anatomical site minor sublingual submand site parotid sex f:m mean age case number tumor type 5 --2 ---5:2 60 7(23.3%) adenoidcystic 1 4 4:1 55 5(16.7%) acinic 1 2 1:2 70 3(10.0%) mucopeidermoid 5 4:1 53 5(16.7%) plga 2 0:2 58 2(6.7%) pl. adenoca. 1 0:1 59 1(3.3%) basal cell ad. 1 1:0 69 1(3.3%) epi.myoep. ca. 1 1:0 26 1(3.3%) adenoca.nos 2 2 4:0 74 4(13.4%) lymphoma 1 1:0 60 1(3.3%) metastastatic 12 2 7 9 21:9 30(100%) total table 4: salivary gland tumor case distribution according to gland site total tumor types and % per site salivary gland malignant benign warthin pl.adenoma 123(100%) 9(7.3%) 7(5.7%) 26(21.1%) 81(65.9%) parotid 20(100 %) 7(35%) --------13(65%) submandibular 2(100%) 2(100%) -----------sublingual 26(100%) 12(46.2%) 5(19.2%) 1(3.8%) 8(30.8%) minor 171(100%) 30(17.5%) 12(7.0%) 27(15.8%) 102(59.7%) total discussion salivary gland tumors are interesting, because of their uncommon incidence in the routine pathology practice and their varied histology. this variation resulted in their complex and constantly changing classifications. currently, the who classification is most widely used, which stresses mainly on the distinction between benign and malignant tumors7. age incidence showed peak value in the sixth and seventh decades (table 1), which is slightly higher than other studies, with no significant difference. incidence was higher in females than males in most of salivary tumor types. the exception was warthin’s tumor, more common in males. this is in concordance with other studies9. histological typing of this series revealed that benign tumors were much more common, the most common type in our series was pleomorphic adenoma, 102 cases of total 171 cases collected(or 59.7%), most of the cases are in the parotid gland. the second most common tumor was warthin’s tumor with 15.8% (27 cases); cases were seen almost exclusively in the parotid gland. the same result was seen in other studies 3,5,15. other benign tumors were much less common, so a total of 12 cases (7%) were collected, 8 cases were basal cell adenoma. there is some variation between studies in regard to the incidence of benign salivary tumors, and which of the types are more common, whether canalicular11 or basal cell adenomas22. a probable cause for this discrepancy is the low incidence rate of these tumors resulting in small number of cases in many of the studies, including ours. malignant tumors were 17.5%(30 cases), most commonly adenoidcystic carcinoma, matching some studies 8, and pleomorphic low grade carcinoma. cases of mucoepidermoid carcinoma were seen less in this series. the parotid gland was the most common site of salivary gland tumors, with 123 cases, which outweigh the mere size and weight difference11. most of the tumors were benign, as most other studies 4,9. pleomorphic adenoma was the most j bagh college dentistry vol. 26(1), march 2014 salivary gland oral diagnosis 91 common tumor type, then warthin’s tumor and other benign tumors. malignant tumors were seen in 9 cases, slightly less than other studies. the most common parotid malignant tumors in our series were acinic cell carcinoma, mucoepidermoid carcinoma and adenocarcinoma, matching other studies. submandibular gland tumors were less common, mostly benign. minor salivary gland tumors were also less common, but with 46% malignancy. immunohistochemical markers were used in most of the malignant tumors and some of the less common benign tumors, to help in the differential diagnosis and to confirm diagnosis. the most commonly used markers were ae1/ae3, actin, s-100, ck-5/6, ck -7, cd-117 and ki-67. other uses of markers in cases of specific diagnoses as in suspected lymphoma or metastatic tumors. review of previous studies on salivary gland tumor from iraq23-26 and from neighboring countries 27-29 show resemblance in most of the results in regard to histological types and incidence of malignancy. minor differences were noted as slight male preponderance in some of these studies 27, and no difference in others 8. the conclusions that can be drawn from this study were that most of the studied parameters regarding salivary gland tumors match those published in the scientific journals. references 1. leegard t, lindman h. salivary gland tumors, clinical picture and treatment. acta otolaryngol 1970; 263:155-9. 2. eveson jw, cawson ra. tumours of minor (oropharyngeal) salivary glands: a demographic study of 336 cases. j oral pathol 1985; 14: 500–9. 3. foote fw jr, frazell el. tumors of the major salivary glands. cancer 1953; 6: 1065-135. 4. batakis jg. tumors of the head and neck: clinical and pathologic considerations, 2nd ed. baltimore: williams and wilkins co.; 1979. 5. thackney ac, sobin lh. histological typing of salivary gland tumors. geneva: who; 1972. 6. simpson rhw. classification of tumors of the salivary glands. histopathology 1994; 24:187-91. 7. barnes l, eveson j w, reichart p, sidransky d (eds). world health organization classification of tumors: pathology and genetics of the head and neck tumors. iarc press; lyon, france: 2005. 8. sirohi d, sharma r, sinha r, menon s. salivary gland tumors: an analysis of 74 cases. j maxillofac oral surg 2009; 8(2):164-6. 9. claudia-patricia mejía-velázquez c,durán-padilla m, gómez-apo e, quezadarivera d, gaitán-cepeda l. tumors of the salivary gland in mexicans. a retrospective study of 360 cases. med oral patol oral cir bucal 2012; 17 (2):e183-9. 10. krolls so, trodahl jn, boyers rc. salivary gland lesions in children.a survey of 430 cases. cancer 1972; 30: 459-69. 11. rosai j, ackerman l. surgical pathology. 10th ed. mosby; 2011. pp. 817-55. 12. patey dh, thackray ac: the treatment of parotid tumours in the light of a pathological study of parotidectomy material. br j surg 1958; 45:477-87. 13. muller s, vigneswaran n, gansler t, gramlich t, derose pb, cohen c. c-erbb-2 oncoprotein expression and amplification in pleomorphic adenoma and carcinoma ex pleomorphic adenoma: relationship to prognosis. mod pathol 1994; 7: 628-32. 14. auclair pl, ellis gl. atypical features in salivary gland tumors: their relationship to malignant transformation. mod pathol 1996; 9: 652-7. 15. eveson jw, cawson ra: warthin's tumor (cystadeno lymphoma) of salivary glands. a clinicopathologic investigation of 278 cases. oral surg oral med oral pathol 1986; 61: 256-62. 16. turnbull ad, frazell el: multiple tumors of the major salivary glands. am j surg 1969; 118: 787-9. 17. kotwall ca: smoking as an etiologic factor in the development of warthin's tumor of the parotid gland. am j surg 1992; 164: 646-7. 18. nascimento ag, amaral alp, prado laf, kligerma j , silveira trp: mucoepidermoid carcinoma of salivary glands. a clinicopathologic study of 46 cases. head neck surg 1986; 8: 409-17. 19. kojima m, shimizu k, nishikawa m, tamaki y, ito h , tsukamoto n, masawa n: primary salivary gland lymphoma among japanese: a clinicopathological study of 30 cases. leuk lymphoma 2007; 48:1793-8. 20. nagao t, sato e, inoue r, oshiro h, takahashi rh, nagai t, et al. immunohistochemical analysis of salivary gland tumors: application for surgical pathology practice. acta histochem cytochem 2012; 45(5): 269-82. 21. de araujo vc, de sousa so, carvalho yr, de araujo ns. application of immunohistochemistry to the diagnosis of salivary gland tumors. appl immunohistochem mol morphol 2000; 8:195–202. 22. ibrahim bello, tuula salo, marilena vered. epithelial salivary gland tumors in two distant geographical locations:a 10-year retrospective comparative study of 2218 cases. head and neck pathol 2012; 6(2):224-231. 23. ahmed st. salivary neoplasms (analysis of 108 cases from mosul). iraq med j 2002; 51:27-30. 24. alash nl, al-saleem t. tumors of the minor and major salivary glands (analysis of 225 cases). j fac med baghdad 1987; 29:103-9. 25. badri gh, al-nakshabandi sa, al-wisasy mk. salivary gland neoplasm: analysis of 89 cases from basra. med j basrah un 2004; 22(192): 12-4. 26. zekinaji a. salivary gland lesion in babil: clinicopathological study. med j babylon 2012; 9(2): 427-32. 27. ma'aita jk, al-kaisin, al – tamimi s, salivary gland tumors in jordan: a retrospective study of 221 patients. croat med j 1999; 40(4):539-42. 28. al-naami my, guraya sy, arofab mm, et al. clinicopathological pattern of malignant parotid tumor in saudia arabia. saudi med j 2008; 29(3): 413-7. 29. kara mi, göze f, ezirganl ş, et al. neoplasms of the salivary glands in a turkish adult population. med oral patol oral cir bucal 2010; 15(6): e880-5. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p): 1817-1869, issn (e): 2311-5270 62 research article assessment of salivary immunoglobulin a interleukin-6 and c-reactive protein in chronic kidney disease patients on hemodialysis and on conservative treatment ithar k. salim 1,*, ameena ryhan diajil 2 1 master student, department of oral diagnosis, college of dentistry, university of baghdad. 2 assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. bab-almoadham, p.o. box 1417, baghdad, iraq correspondence: albadric@tcd.ie abstract: background: chronic kidney disease is a gradual loss of kidney function with diabetes and hypertension as the leading cause. chronic kidney disease is one of these systemic diseases that can affect salivary contents. aims: this study aimed to assess salivary immunoglobulin a, interleukin-6 and creactive protein in chronic kidney disease patients on hemodialysis and those on conservative treatment in comparison with control subjects. materials and methods: ninety subjects were included in this study divided into three groups: 30 patients with chronic kidney disease on hemodialysis for at least 6 months ago; 30 patients with chronic kidney disease on conservative treatment and 30 healthy control subjects. secretory immunoglobulin a, interleukin-6 and creactive protein in saliva samples were measured by enzyme-linked immunosorbent assay elisa. results: no significant difference in salivary immunoglobulin a level among study groups was seen. a significant increase in salivary interleukin-6 and creactive protein in both chronic kidney disease patients on hemodialysis and those on conservative treatment compared to the control group. while, no significant salivary il-6 and crp differences were seen between both patient groups, on hemodialysis and conservative treatment. conclusions: there was no significant difference among chronic kidney disease patients on hemodialysis, on conservative treatment and control healthy subjects regarding to salivary iga while salivary interleukin -6 and creactive protein was significantly higher in chronic kidney disease patients on hemodialysis and those on conservative treatment compared to healthy subjects. keywords: chronic kidney disease, hemodialysis, salivary iga, salivary il-6 and salivary crp. introduction chronic kidney disease (ckd) is a progressive reduction in kidney function (1), with the prevalence and incidence growing worldwide with diabetes and hypertension as the leading cause (2). chronic kidney disease is classified into five stages according to the level of proteinuria and kidney function which is measured by the estimated glomerular filtration rate (egfr) which is derived from age, gender, race and serum creatinine concentration (3). patients develop end-stage renal disease (esrd) once bilateral deterioration of nephrons pass the point of compensation therefore; dialysis therapy and renal transplantation are life-saving procedures in these patients (4). although renal transplantation is the preferred method of treatment for patients with esrd, the majority of patients are placed on dialysis either while awaiting transplantation or as their only treatment (5). in hemodialysis, urea and other low molecular weight substances diffuse during interchange from the patient’s blood across an extra-corporal filtering /dialysis membrane into an electrolyte and received date: 15-1-2022 accepted date: 1-3-2022 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v34i2.3146 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i2.3146 https://doi.org/10.26477/jbcd.v34i2.3146 j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 63 ph-balanced dialysis solution (6). the frequency and duration of dialysis are related to residual kidney function, protein intake, body size and tolerance to fluid elimination. typically, the patient undergoes hemodialysis three times per week, with each treatment session about three to four hours on standard dialysis units and slightly less time on high efficiency or high-flux dialysis units (7). studies showed that up to 90% of patients with kidney disease were found to have oral findings of uremia. some of the presenting signs in renal patients were an ammonia-like taste and smell, gingivitis, stomatitis, reduced salivary flow, xerostomia, and parotitis (7). the resultant anemia due to diminished erythropoietin leads to the paleness of the oral mucosa. impairment of platelet function occurs during uremia (8). this situation combined with the heparin use and other anticoagulants in hemodialysis leads patients to become prone to ecchymosis, petechiae, and hemorrhages in the oral cavity (9). saliva is a filtrate of the blood where different molecules pass through transcellular or paracellular routes (passive intracellular diffusion and active transport or extracellular ultrafiltration respectively) into saliva. as a result, saliva is equivalent to serum, therefore reflecting the physiological state of the body (10). numerous systemic diseases have been reported to cause marked and identifiable alterations in salivary secretion. ckd is one of these systemic diseases that can affect the contents of salivary secretion (11). immunoglobulin a (iga), is a serum immunoglobulin and the dominant antibody class in the external secretions that bathe mucosal surfaces, which plays key roles in immunological protection. while serum iga is predominantly monomeric in nature, the iga in secretions (secretory iga, s‐iga) is chiefly polymeric, comprising mainly dimeric forms (12). it has been reported that immunoglobulin levels, serum igg isotypes, and both iga and igm production are normal in patients on dialysis (13). the cytokines that are produced during inflammatory episodes, and that participate in them, are stimulators to produce acute-phase proteins. these inflammation-related cytokines include il-1β, il-6, tumor necrosis factor-α (tnf-α), interferon-γ, and transforming growth factor-β, with the most im‐ portant ones are macrophages and monocytes at sites of inflammation. il-6 is the main stimulator of the most acute phase of proteins production (14). c-reactive protein is an acute-phase protein synthesized in the liver and secreted into the bloodstream during an inflammatory process, mostly in response to il-6 signaling and, to a lesser extent, il-1β and other pro-inflammatory cytokines (15). the inflammatory response can reflect an underlying systemic disease. chronic kidney disease patients demonstrate inflammatory pathways activation, which is accompanied by increased inflammatory markers like cytokines. the increased cytokines levels such as interleukin-6 (il-6) and tumor necrosis factor-alpha (tnf-α) have been shown in esrd. moreover, these inflammatory markers act as toxins that predict deterioration of kidney function (16). in oral cavity, these cytokines play an important role in the inflammatory response in the periodontium (17). materials and methods ninety subjects were included in this study, divided into three groups: thirty patients with chronic kidney disease on hemodialysis for at least 6 months ago; thirty patients with chronic kidney disease on conservative treatment without hemodialysis and thirty healthy control participants with no signs and symptoms of any systemic disease, as a control group. patients were taken from al-kindey teaching hospital in al-kindey dialysis center in baghdad during the period from december 2017 to the end of february 2018. patients under chemotherapy or/and radiotherapy, patients undergoing hemodialysis due to acute kidney failure or accident and hepatitis patients, were excluded from this study. for each participant in this study, a case sheet that included patients' demography, risk factors, family history, medical j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 64 history, history of present illness, investigations, oral manifestations and salivary parameters (salivary flow rate, ph) was filled. an oral examination was performed d for each participant using a dental mirror with artificial light with the oral manifestations recorded. after the oral examination, saliva was collected from all individuals under the same conditions and each participant was instructed to rinse and wash his/her mouth with distilled water before saliva collection. saliva was collected before a meal or at least one hour after a meal by spitting method for about 5-minutes. sampling sessions are limited to the hours between 9:00 and 11:00 am to minimize the effect of diurnal variations. the samples were identified by a code number during the time of sample collection and processing. after the disappearance of the salivary froth, the salivary flow rate was calculated in milliliters per minute and ph was measured by a digital ph meter. after the collection of saliva samples, they were placed in a small cooler box and then, centrifuged at 3000 rpm for 10 minutes (lasisi et al., 2015). the clear supernatant was taken and stored at -20°c until the time of analysis. secretory iga, il-6 and crp in saliva sample were measured by microplate reader mindray mr-96a using elisa kit for iga, il-6 and crp, respectively. statistical analysis: statistical analysis was performed with spss (statistical package for social sciences; version 21). descriptive statistical analysis, contingency coefficient, fisher exact, chi-square, analysis of variance (anova), post-hoc (lsd and dunnett t3) tests and person correlation coefficient (r) were used in this study. p ˂ 0.05 significant; p ˂ 0.01 highly significant; p ˃ 0.05 non-significant. results demographic finding demography the age range at the first presentation was 25-75 years with an overall mean age of 49.6 years. forty-six of them were males with a mean age of 47.8 and 44 of them were females with a mean age of 51.4. thirty patients were with ckd on hemodialysis with an age range of 37-75 years and a mean age of 55.3. seventeen of them were males and 13 were females, other thirty patients were with ckd on conservative treatment with an age range of 25-75 years and a mean of 49.3. sixteen of them were males and 14 were females and thirty healthy subjects with an age range of 27-63 years and a mean of 44.2. thirteen of them were males and 17 were females. the participants were classified into two age categories: (≤ 50) and (more than 50 years of age). a statistical analysis using contingency coefficient showed no significant difference in relation to age (p= 0.06) or gender (p= 0.056) among the study groups; table (1). j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 65 table 1: distribution of ckd patients and control groups according to age and gender. p-value c.c groups control ckd ckd (hd) 0.060 ns 0.243 20 (66.6) 17 (56.6) 11 (36.6) no. (%) ≤ 50 age 10 (33.3) 13 (43.3) 19 (63.3) no. (%) more than 50 0.561 ns 0.113 13 (43.3) 16 (53.3) 17 (56.6) no. (%) male gender 17 (56.6) 14 (46.6) 13 (43.3) no. (%) female c.c: contingency coefficient ckd (hd): chronic kidney disease on hemodialysis ckd: chronic kidney disease on conservative treatment regarding occupation, thirty-one (34.4%) of the participants were retired followed by 24 (26.67%) who were unemployed then 22 (24.4%) were workers and 13 (14.4%) were officers. in ckd patients on hemodialysis, the majority were unemployed 13 (43.3%) followed by 9 (30%) were retired, 4 (13.3%) were workers and 4 (13.3%) were officers. of those on conservative treatment most of them were retired 14 (46.6%) followed by 10 (33.3%) were workers, 3 (10%) were unemployed and 3 (10%) were officers. in the control group, 8 (26.6%) were retired, 8 (26.6%) were unemployed, 8 (26.6%) were workers and 6 (20%) were officers. a statistical analysis using the contingency coefficient showed that there was no significant difference among study groups regarding occupation (p= 0.06). considering marital status, married participants were the most common (67) followed by single (16), widowed (5) and divorced (2). in ckd patients on hemodialysis, the majority were married 27 (90%) and 3 (10%) were single. in those on conservative treatment, 19 (63.3%) were married followed by 6 (20%) were single, 3 (10%) were widowed and 2(6.6%) were divorced. in the control group, 21 (70) were married followed by 7 (23.3%) who were single and 2 (6.6%) were widowed. also, there was no significant difference among study groups considering marital status (p= 0.21). smoking status the majority of the participants were non-smokers (71, 78.89%) followed by the current smoker (14, 15.56%) and ex-smoker (5, 5.56%). in ckd patients on hemodialysis, 26 (86.6%) were non-smokers, 3 (10%) were ex-smokers and 1 (3.3%) were current smokers. of those on conservative treatment, 22 (73.3%) were non-smokers, 2 (6.6%) were ex-smokers and 6 (20%) were current smokers. while in the control group, 23 (76.6%) were non-smokers and 7 (23.3) were current smokers. by using fisher's exact test, the result showed that there was no significant difference among study groups in relation to smoking status (p= 0.058). current smokers were divided into three groups according to the number of cigarettes smoked per day: light (˂ 10), intermediate (10-20), and heavy smokers (˃ 20). overall, intermediate smokers were the most common (11). in ckd patients on hemodialysis, 1 (7.1%) was an intermediate smoker. in those on conservative treatment, 5 (35.7%) were intermediate smokers and 1 (7.1%) was a heavy smoker. in the control group, 1 (7.1%) was a light smoker, 5 (35.7%) were intermediate smokers and 1 (7.1%) was a heavy smoker. also, by using fisher's exact test, the result showed that there was no significant difference among study groups regarding to number of cigarettes (p= 1.00). medical history in relation to patients' medical history, 35 (58.33%) of ckd patients were with diabetic mellitus followed by 34 (56.67%) with hypertension. of patients on hemodialysis, (14, 46.67%) were diabetic and j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 66 (19, 63.33%) were hypertensive. while in those on conservative treatment, (21, 70%) were diabetic and 15 (50%) were hypertensive. by using the chi-square test, the result showed that there was no significant difference between patient groups regarding diabetic and hypertension (p= 0.06, p= 0.29); table (2). table 2: medical history of chronic kidney disease patients. p value chi-square groups ckd ckd (hd) 0.067 (ns) 3.36 21 (70) 14 (46.6) no. (%) diabetic 0.29 (ns) 1.08 15 (50) 19 (63.3) no. (%) hypertension ckd (hd): chronic kidney disease on hemodialysis ckd: chronic kidney disease on conservative treatment family history: considering family history, 12 (20%) ckd patients were with a 1st relative degree history of ckd and 2 (3.3%) were with 2nd relative degree. in hemodialysis patients, 5 (16.6%) were with 1st relative degree and 1 (3.3%) was with 2nd relative degree family history of ckd. while in patients on conservative treatment, 7 (23.3%) were with 1st relative degree and 1 (3.3%) were with 2nd relative degree family history. using the chi-square test, the result revealed that there was no significant difference between patients groups in relation to family history (p= 0.51, p= 1.00); table (3). table 3: family history of chronic kidney disease patients. p-value chi-square groups ckd ckd (hd) 0.51 (ns) 0.41 7 (23.3) 5 (16.6) no. (%) 1st degree 1.00 (ns) 0.00 1 (3.3) 1 (3.3) no. (%) 2nd degree ckd (hd): chronic kidney disease on hemodialysis ckd: chronic kidney disease on conservative treatment salivary immunoglobulin a: using anova test, there was no significant difference in salivary iga level among ckd patients on hemodialysis, those on conservative treatment and control group (p= 0.3); table (4). table 4: mean salivary iga level in studied groups with anova test. p value f range se mean ± sd groups 0.301 ns 1.219 33.63426.24 22.72 232.68 ± 124.42 ckd (hd) iga µg/ml 70.90415.50 17.76 234.76 ± 97.28 ckd 50.67431.46 16.99 196.82 ± 93.05 control f: anova ckd (hd): chronic kidney disease on hemodialysis ckd: chronic kidney disease on conservative treatment j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 67 salivary interleukin6: using anova test, there was a significant difference in salivary interleukin6 in ckd patients on hemodialysis, those on conservative treatment and control group as shown in table (5). table 5: mean salivary interleukin6 of study groups with anova test. f: anova ckd (hd): chronic kidney disease on hemodialysis ckd: chronic kidney disease on conservative treatment using post hoc (lsd) test, the result shows that there was a significant increase in salivary interleukin6 in ckd patients on hemodialysis and those on conservative treatment compared to the control group (p= 0.00, p= 0.03). while there was no significant difference in salivary il-6 was seen between ckd patients on hemodialysis and those on conservative treatment (p= 0.33). salivary creactive protein table (6) shows that there was a significant difference in salivary crp in ckd patients on hemodialysis, those on conservative treatment and control group. table 6: mean salivary crp of study groups with anova test. sig. f range se mean ± sd group 0.014 s 4.49 0.704.58 0.16 2.18 ± 0.86 ckd (hd) crp (mg/l) 0.873.87 0.16 2.20 ± 0.86 ckd 0.605.97 0.24 1.50 ± 1.32 control f: anova ckd (hd): chronic kidney disease on hemodialysis ckd: chronic kidney disease on conservative treatment using post hoc (lsd) test, the result showed that there was a significant increase in salivary crp in ckd patients on hemodialysis and those on conservative treatment compared to the control group (p= 0.01, p= 0.01). while there was no significant difference was found between salivary crp in ckd patients on hemodialysis and those on conservative treatment (p= 0.93). correlation coefficient a significant positive correlation was found between salivary il-6 and crp in ckd patients on hemodialysis (r= 0.781, p=0.00), those on conservative treatment (r= 0.840, p= 0.00) and in control group (r= 0.816, p= 0.00) as shown in table (7). p value f range se mean ± sd group 0.005 s 5.53 70.41-349.54 12.98 161.41 ± 71.11 ckd (hd) il-6 (ng/l) 76.98265.76 8.94 146.17 ± 48.98 ckd 68.67307.87 10.94 110.64 ± 59.94 control j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 68 table 7: correlation between salivary il-6 and crp in ckd patients and control group. crp group 0.781 r il-6 ckd on hemodialysis 0.000 p 0.840 r il-6 ckd on conservative treatment 0.000 p 0.816 r il-6 control 0.000 p discussion this study showed that the mean age of ckd patients on hemodialysis was 55.3 years while the mean age of ckd with conservative treatment was 49.3 years. this agrees with denic et al., (2016)(18) who explained that kidney function decline with age. considering gender, males were more than females in both patient groups. in ckd patients on hemodialysis, 17 were males and 13 were females while in ckd patients with conservative treatment, 16 were males and 14 were females. this result is in agreement with goldberg and krause (2016)(19) who found that a higher progression rate and mortality risk was seen in ckd males patients compared to females, while this result inconsistent with ahmed et al. study (2015) (20) who reported that females patients were more than males patients. sex hormones are thought to play an important role in the biological mechanisms associated with variability in ckd prevalence and characteristics between males and females. animal studies have demonstrated the harmful effect of testosterone and the protective effect of estrogen on several biological processes that are involved in renal damage. however, the role of sex hormones in clarifying gender-related differences in ckd in humans has not yet been established (19). in this study, there were no significant differences among the studied groups regarding age and gender. this result is parallel with other study done by khozeymeh et al. (2016) (16). there was no significant difference among study groups considering to occupation and marital status. this result coincides with a study done by huda et al., (2012)(21) for occupation, while it disagrees with the same study in relation to marital status. another study was done by pinho et al., (2015) (22) found that there was a significant association between ckd and marital status, which disagrees with the current study regarding marital status. living with a partner has been considered a family support indicator, which would be associated with better treatment commitment by ckd patients and better health outcomes (23). this positive effect of living with a partner was not observed in the current study, which may be due to different population circumstances. regarding smoking and the number of cigarettes per day, no significant difference among study groups which is inconsistent with a study done by yacoub et al., (2010) (24) who found that current smokers were under an increased risk of having ckd compared to nonsmokers. many studies explained that smoking is a risk factor for the progression of ckd (25, 26) in this study, the majority of patients were either diabetic or hypertensive. in ckd patients on hemodialysis, the majority were with hypertension, while for those on conservative treatment, diabetic mellitus was the most common, however, chi square test was non-significant. this is in agreement j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 69 with other studies were done by lea and nicholas (2002) (27) and suleymanlar et al. (2011) who reported that diabetes mellitus and hypertension were common among ckd patients. however, this disagrees with another study done by kabir et al., (2012) (28) who found that there was a significant difference between cases and control regarding diabetic mellitus and hypertension. diabetes mellitus and hypertension may be considered important causes of ckd; therefore, the international guidelines recommend yearly screening for ckd in diabetic or hypertensive patients (29). uncontrolled diabetes and/or hypertension can easily and quickly progress to end stage renal disease (30). the majority of patients in both patients groups; on hemodialysis and on conservative treatment were with 1st degree relative family history of ckd. no significant difference among studied groups in relation to 1st and 2nd family history. this is parallel with a study done by kabir et al., (2012) (28) who found no significant difference regarding risk factor like family history. but, inconsistent with another study done by orantes et al., (2011) (31) who found that developing ckd is significantly influenced by family history of ckd. a family history of kidney disease is one of the crucial risk factors for ckd. therefore, it is advisable to screen high-risk family members of ckd patients to prevent the disease (30). in the present study, no significant difference in salivary iga level among study groups was found. this is inconsistent with other studies which reported a significantly higher level of salivary iga in ckd patients compared to healthy subjects (32, 33). discrepancies among these results could be attributed to the differences in the sample size, patient factors and absence of infections. regarding salivary il-6, a significant difference in salivary il-6 levels among study groups was found. however, no significant salivary il-6 difference between the two patient groups. a significantly higher level of salivary il-6 in ckd patients on hemodialysis compared to the control group was seen. this finding is consistent with a study done by khozeymeh et al. (2016) (16) who reported a significant increase in salivary il-6 levels in hemodialysis patients compared to control subjects. also, a significant increase in salivary il-6 in ckd patients on conservative treatment compared to the control group was found. this is consistent with ersson et al. (2011) (34) who reported a higher level of salivary il-6 in ckd patients compared to control subjects, but unfortunately it was measured in a limited number of patients which was non statistically significant. increased inflammatory biomarkers levels in ckd can promote atherosclerosis and thrombosis (35). these mechanisms may explain the high prevalence of the cardiovascular disease among ckd patients. therefore, the measurement of cytokine levels in saliva may be considered a noninvasive test for cardiac risk stratification in hemodialysis patients (16). many oral diseases including oral cancer, lichen planus and periodontal diseases have been reported to be associated with il-6 deregulation (17). periodontal diseases are prevalent in patients on hemodialysis who showed bad oral care and their prevalence increases with the chronicity of the disease (hamissi et al., 2009). the important role of il-6 in the loss of periodontal ligament and alveolar bone through tissue degradation effects of il-6 on connective tissue and bone, mediated by metalloproteinase and osteoclasts activity (17). to our knowledge, few studies were performed to investigate the salivary il-6 level in ckd patients, so further studies may be needed to confirm the pathological role of il-6 in ckd patients. regard j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 70 ing salivary crp, there was a significant difference among the study group. however, there was no significant difference in salivary crp levels between the two patient groups. a significantly higher salivary crp level in hemodialysis patients and those on conservative treatment compared to the control group was seen. pallos et al. (2015) (36) found that there was a significantly higher level of salivary crp in patients on hemodialysis compared to normal subjects while no significant difference between those on conservative treatment and normal subjects. this finding agrees with the current study regarding hemodialysis patients but disagrees with the findings of conservative treated patients. a few studies regarding crp in the saliva of patients with ckd. however, several studies measured it in the serum of ckd patients and found a significant increase in crp levels in the serum of patients with ckd (34, 37). importantly, periodontal disease can worsen ckd. a systemic review and meta-analysis reported an increased prevalence of ckd in patients with periodontitis (38). many studies have proved a positive association between the presence of chronic periodontitis and a high level of serum crp (39, 40). inflammatory cytokines (il-6, il-1 and tnf-α) are released in a response to periodontal infection and stimulate hepatocytes to produce crp. therefore, in the presence of chronic periodontitis, higher serum crp levels would be found (41). a significant positive correlation between salivary il-6 and crp in ckd patients and the control group. il-6 is known to induce the production of crp in the liver (42). therefore, as expected, the levels of il-6 and crp were positively correlated in this study. conclusion there was no significant difference between ckd patients and control healthy subjects regarding to salivary iga. salivary il-6 and crp were significantly higher in ckd patients on hemodialysis and those on conservative treatment compared to control healthy subjects. there was a significant positive correlation between salivary il-6 and crp in ckd patients and also in control healthy subjects. patients with ckd need comprehensive professional oral care and self-care instructions. conflict of interest: none. references 1. venkatapathy, r., govindarajan, v., oza, n., parameswaran, s., pennagaram dhanasekaran, b., & prashad, k. v. salivary creatinine estimation as an alternative to serum creatinine in chronic kidney disease patients. int. j.nephrol.2014. 2. levey, a.s., eckardt, k.u., tsukamoto, y., levin, a., coresh, j., rossert, j., zeeuw, d.d., hostetter, t.h., lameire, n. and eknoyan, g. definition and classification of chronic kidney disease: a position statement from kidney disease: improving global outcomes (kdigo). ki. 2005; 67(6): .2089-2100. 3. levin, a., stevens, p.e., bilous, r.w., coresh, j., de francisco, a.l., de jong, p.e., griffith, k.e., hemmelgarn, b.r., iseki, k., lamb, e.j. and levey, a.s. kidney disease: improving global outcomes (kdigo) ckd work group. kdigo 2012 clinical practice guideline for the evaluation and management of chronic kidney disease. ki supplements. 2013; 3(1): 1-150. j. bagh. coll. dent. vol. 34, no. 1. 2022 salim and diajil 71 4. dağ, a., fırat, e.t., kadiroğlu, a.k., kale, e. and yılmaz, m.e. significance of elevated gingival crevicular fluid tumor necrosis factor‐α and interleukin‐8 levels in chronic hemodialysis patients with periodontal disease. j. periodontal res. 2010; 45(4): 445-450. 5. fenton, s.s., schaubel, d.e., desmeules, m., morrison, h.i., mao, y., copleston, p., jeffery, j.r. and kjellstrand, c.m. hemodialysis versus peritoneal dialysis: a comparison of adjusted mortality rates. am, j. kidney dis. 1997; 30(3): 334-342. 6. craig, r.g. interactions between chronic renal disease and periodontal disease. oral dis. 2008; 14(1): 1-7. 7. glick m. and feagans wm. burket's oral medicine, ed 12. shelton, people's medical publishing house-usa, 2015. 8. mcmillan, r., skiadopoulos, l., hoppensteadt, d., guler, n., bansal, v., parasuraman, r. and fareed, j. biomarkers of endothelial, renal, and platelet dysfunction in stage 5 chronic kidney disease hemodialysis patients with heart failure. cath. 2018; 24(2): 235-240. 9. seraj, b., ahmadi, r., ramezani, n., mashayekhi, a. and ahmadi, m. oro-dental health status and salivary characteristics in children with chronic renal failure. j. dent. 2011; (tehran, iran), 8(3): 146. 10. bagalad, b.s., mohankumar, k.p., madhushankari, g.s., donoghue, m. and kuberappa, p.h. diagnostic accuracy of salivary creatinine, urea, and potassium levels to assess dialysis need in renal failure patients. drj. 2017; 14(1): 13. 11. lasisi, t.j., raji, y.r. and salako, b.l. salivary creatinine and urea analysis in patients with chronic kidney disease: a case control study. bmc nephrol. 2016; 17(1): 10. 12. hand, t.w. and reboldi, a. production and function of immunoglobulin a. annual review of immunology. 2021; 39: 695-718. 13. eleftheriadis, t., antoniadi, g., liakopoulos, v., kartsios, c. and stefanidis, i. basic science and dialysis: disturbances of acquired immunity in hemodialysis patients. in semin. dial. 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(1) mithaq radhi mohammed, b.d.s., m.sc. (2) abstract background: dental stone casts come into contact with impression materials and becomes susceptible to cross contamination from saliva and blood. this study was done to evaluate the physical and mechanical properties of dental stone type iv after treatments with various disinfecting agents and regimes (methods). materials and methods: type iv dental stone and different types of disinfecting agents were used and divided into seven groups: g1: dental stone without disinfection (control group), g2: dental stone mixed with silver nitrate powder 0.5% , g3: dental stone mixed with silver nitrate powder 1%, g4: dental stone mixed with copper sulfate powder 0.5%, g5: dental stone mixed with copper sulfate powder 1% ,g6: dental stone immersed in propanol 70% and g7: dental stone immersed in ethanol 70%.setting time, linear setting expansion, surface detail reproduction, compressive strength of type iv dental stone as well as compatibility with auto mixing addition silicone impression material were evaluated. the statistical analysis were conducted by anova test followed by lsd test (p<0.05), also chi square test was used. results: the compressive strength, linear setting expansion, surface detail reproduction and compatibility of stone specimens was affected to a higher extent by mixing with silver nitrate powder 1%, copper sulfate powder 1% while treating the stone specimens with the disinfecting powders at low concentrations as well as immersion of stone specimens in either ethanol or propanol for 15 minutes produce less effect on the previous tested properties. conclusion: silver nitrate 0.5%, copper sulfate 0.5% powders as well as 15 minutes immersion in 70% ethanol or 70% propanol did not promote adverse alterations in most of evaluated properties of type iv dental stone. key words: gypsum products, metallic disinfectants, ethanol, propanol. (j bagh coll dentistry 2014; 26(1):24-31). introduction the need for an infection control program is felt because a number of bacteria, fungi, and viruses present in the dental environment have been linked to debilitating and life-threatening diseases. every effort, therefore, must be made to avoid cross contamination of these microorganisms and to prevent the potential transfer of disease in the dental setting. one common dental procedure that may cause cross contamination, especially between patients and dental laboratory personnel, is transfer of infectious agents from blood and saliva to the casts through impressions, record bases, occlusion rims, and trial dentures (1,2). gypsum products have been considered to be among the most widely used model and die materials. modifications of these materials by adding chemicals or salts result in a change in their structure (2,3).. american dental association (ada) and the center for disease control and prevention (cdc) have suggested methods for the disinfection of dental casts including immersion in or spraying with a disinfectant (3) .several studies have been attempted to come up with an improved system for models and die constructions (4), other studies attempted to improve the mechanical properties of gypsum products and oriented mainly towards the decrease of water requirement (5). (1)assistant professor. department of prosthodontics, college of dentistry, university of baghdad (2)lecturer. department of prosthodontics, college of dentistry, university of baghdad in order to improve gypsum materials many attempts have been made by the use of various additives to gain several modification related to the chemical, mechanicals, physical and other properties of gypsum material (6,7) . chemical disinfectants can also be added directly to the dental stone (8,9). however, adding disinfectant in dental stone, have been reported to compromise critical properties of the cast such as compressive strength, setting time and dimensional accuracy (10,11). this study was done to develop a dental stone with disinfecting properties and still has adequate physical and mechanical properties. materials and methods in this study type iv dental stone (elite stone, navy blue. rovigoitaly) was used. ten specimens were prepared for each tested property following the water powder ratio recommended by the manufacturer instructions (powder water ratio 100gm/25ml). the dental stone was immediately poured in the molds with the aid of a mechanical vibrator, the stone specimens were separated from the molds 45 minutes after the starting of the mix and left to dry for 24 hours at (23±2)ºc before testing. two different disinfection methods (incorporation and 15 minutes immersion for the set gypsum specimens) were applied and four disinfectant agents were used 0.5% , 1% silver nitrate (scrc, china: sinopharm chemical reagent company) ,0.5% , 1% copper sulphate (barcelona, espana), 70%propanol and j bagh college dentistry vol. 26(1), march 2014 effect of disinfectant restorative dentistry 25 70% ethanol .the following physical and mechanical properties were evaluated for the prepared stone specimens: 1. setting time according to ada specification no.25, metal ring (2.5 cm inside diameter and 2.5 cm high) was used to test the setting time of the disinfected stone specimens using apparatus with 1 ± 0.05 mm needle diameter and 240 g weight (b.s.12: part 2:1971). standard mix of 200g powder and 50 ml distilled water according to manufacturers instruction was prepared and immediately transferred to the cylindrical mold painted with separating medium (shanghai new century dental material co.ltd) then the needle tip brings in contact with the surface of the tested material locking it in position with the thumb screw, the needle was released and allowed to penetrate the sample at 15 second intervals. after each penetration the needle was cleaned and the mold moved to allow another penetration in a new area, the average value for two tests was measured as initial setting time, figure (1). 2. linear setting expansion to evaluate and compare linear setting expansion of conventional type iv dental stone (control group) and the experimental groups (disinfected specimens), 10 stone specimens were prepared for the control and the experimental groups. metallic model with of seven slots with widths ranging from 0.025 to 0.300 mm and 2.5 mm of distance between the grooves according to ada specification no. 25 for dental gypsum products was used (22) , figure (2). rubber ring 30 mm in diameter and 15 mm high was placed on the test block so that the intersection of a cross line and a groove 0.050 mm depth is in the center of the ring , the stone powder was weighed on an electronic balance (±0.2%) and mixed with distilled water that measured by using a graduated cylinder according to the ratios recommended by the manufacturer. after mixing the stone mix was poured inside rubber ring under vibration then the ring and the gypsum material was separated from the test block at 45 minutes according to manufacturer's instructions, ab distance (which represent the distance between groove 0.050 mm and groove 0.150 mm) was measured by using computerized soft ware program (corel draw x4), figure (3). figure 1: vicat device for measuring fig. 2: metal block for linear expansion test the setting time of gypsum products b fig. 3: gypsum sample prepared for linear expansion test (ab: represent the distance between four lines carved on the metal block) j bagh college dentistry vol. 26(1), march 2014 effect of disinfectant restorative dentistry 26 3. surface detail reproduction to evaluate and compare surface detail reproduction of conventional type iv dental stone (control group) with the disinfected gypsum specimens (experimental groups), 10 specimens for each gypsum group were prepared on the test block previously used for linear setting expansion test. rubber ring (15 mm high and 30 mm in diameter) was used and the stone specimens were separated from the test block at 45 minutes according to manufacturer's instructions , the stone specimens were tested under x5 magnification microscope (olympus bx51m with digital camera mounted on the microscope and connected to the computer) with low angle lighting, figure (4) .the surface detail reproduction will be satisfactory if the 0.050 mm depth groove is continuous for the length inside diameter of the plastic ring, figure (5). fig.4: low lighting microscope fig.5: optical microscope illustrates the used for surface roughness evaluation continuity of 0.050 mm line regarding surface detail reproduction test the following scoring system with rating values from one to four was used as follows (2): rating 1: well defined, sharp detail and continuous line. rating 2: continuous line but with some loss of sharpness. rating 3: poor detail or loss of continuity of line. rating 4: marginally or completely discernible line. 4. compatibility with addition silicone impression material compatibility of type iv dental stone with the elastomeric impression material was conducted according to ada specification no.19, 10 stone samples were prepared for the same metallic block that used for the linear setting expansion test, a plastic ring (30 mm diameter and 15 mm high) was placed on the test block so that the groove 0.025 mm wide was reproduced on the gypsum surface, 10 vinyl polysiloxane (syringe type) elastic impressions were taken for the test block, figure (6) .boxing was done for these impressions and the stone was poured inside the waxed impressions then after 45 minutes (according to manufacturer's instructions) stone samples were removed from the waxed impressions and the surface area was examined by using optical microscope with x5 magnification power. the gypsum compatibility is considered satisfactory if the 0.025 mm width groove is continuous for the length inside diameter of the plastic ring. fig. 6: auto mix elastic impression material 5. compressive strength for compressive strength test 10 stone samples were prepared using split mold 20 mm in diameter and 40 mm high according to ada specification no.25, the split mold was placed on a glass plate so that the ends of the samples remained flattened and vibrated gently while the stone mix was poured inside the mold then the overfilled mold was covered with a second glass plate and pressed firmly. the specimens were removed from the split mold at 45 minutes (according to manufacturer's instructions) from the start of the mix, stored for 24 hours, then the stone samples figure (7) were crushed at a loading of 7.5 kn. the test was performed with hydraulic press testing machine, figure (8), the compressive strength was calculated according to the following formula: compressive strength = load (n) / surface area (mm2). the average value of the 10 readings was dependent for the compressive strength test. j bagh college dentistry vol. 26(1), march 2014 effect of disinfectant restorative dentistry 27 fig. 7: gypsum samples for compressive fig 8: hydraulic press machine strength test results the addition of agno3 and cuso4 disinfectant powders to the type iv dental stone showed a clear reduction in the initial setting time in comparison to the control group. table 1: setting time for the control and experimental groups groups setting time minutes seconds control 11 00 ag no30.5 % 10 10 agno3 1 % 8 30 cuso4 0.5 % 4 33 cuso4 1 % 6 50 the results of this study showed that the disinfectant agents produced a significant reduction in the mean value of the linear setting expansion in comparison to the control group, this result was found by anova test but lsd test revealed a non significant difference between g1& g2, g1&g4 also between g1&g7 regarding the linear expansion mean values as shown in table (2)& table (3). table 2: descriptive statistical analysis and anova test of setting expansion for the control and experimental groups table 3: lsd analysis test of setting expansion for the control and experimental groups **p<0.01 highly significant. groups setting expansion (mm) groups’ comparison n mean sd df f-test p value sig. (g1) control 10 7.9285 0.0111 29 6.591 0.005 **hs (g2) agno3 0.5 % 10 7.8776 0.0067 (g3) agno3 1 % 10 7.7619 0.1808 (g1) control 10 7.9285 0.0111 29 31.749 0.000 **hs (g4) cuso4 0.5 % 10 7.8700 0.0718 (g5) cuso4 1 % 10 7.7760 0.0158 (g1) control 10 7.9285 0.0111 29 7.312 0.003 **hs (g6) ethanol 70 % 10 7.8520 0.0759 (g7) propanol 70 % 10 7.9250 0.0406 studied groups pvalue sig. g1 & g2 0.171 ns g1 & g3 0.000 hs g2 & g3 0.002 hs g1 & g4 0.115 ns g1 & g5 0.000 hs g4 & g5 0.010 hs g1 & g6 0.040 s g1 & g7 0.971 ns g6 & g7 0.043 s j bagh college dentistry vol. 26(1), march 2014 effect of disinfectant restorative dentistry 28 the addition of agno3 and cuso4 to the type iv dental stone resulted in a statistically significant reduction in the mean values of compressive strength in comparison to the control group while a statistically in significant difference in the mean values of compressive strength was observed for the stone specimens after immersion in alcohols for 15 minutes (ethanol or propanol) in comparison to the control group, table (4). table 4: descriptive statistical analysis and anova test of compressive strength (mpa) for the control and experimental groups ** p<0.01 highly significant. further analysis using lsd test revealed that no significant differences were found between the control group and the experimental groups (g2, g6, g7), also a non significant difference was observed between g4 and g5 groups regarding the compressive strength of dental stone used in this study, table (5). table 5: lsd analysis test of compressive strength (mpa) for the control and experimental groups table (6) showed that mixing high concentrations of agno3 and cuso4 adversely affected the surface detail reproduction of type iv dental stone. none of the examined casts showed grade 4 surface quality. table 6: presents the results of chi-square analysis (the percentage values) of the surface detail reproduction of the control and the experimental groups. x2= 38.719, df =12, p-value = 0.000(hs), likelihood ratio=46.135, df = 12, p-value=0.000(hs) groups compressive strength n/m2 (mpa) groups’ comparison n mean sd df f value p value sig. (g1) control 10 19.8465 0.8877 29 334.740 0.000 **hs (g2) agno3 0.5 % 10 19.6485 0.4263 (g3) agno3 1 % 10 13.4964 0.4454 (g1) control 10 19.8465 0.8877 29 24.430 0.000 **hs (g4) cuso4 0.5 % 10 17.0330 1.0860 (g5) cuso4 1 % 10 16.9170 1.1882 (g1) control 10 19.8465 0.8877 29 1.112 0.344 ns (g6) ethanol 70 % 10 18.6670 2.4183 (g7) propanol 70 % 10 17.5655 4.9473 studied groups pvalue sig. g1 & g2 0.484 ns g1 & g3 0.000 hs g2 & g3 00000 hs g1 & g4 0.000 hs g1 & g5 0.000 hs g4 & g5 0.908 ns groups rankings i ii iii total control 8 (80%) 2 (20%) 0 (0%) 10 (100%) agno3 0.5% 8 (80%) 2 (20%) 0 (0%) 10 (100%) agno3 1% 0 (0%) 6 (60%) 4 (40%) 10 (100%) cuso4 0.5% 2 (20%) 6 (60%) 2 (20%) 10 (100%) cuso4 1% 1 (10%) 7 (70%) 2 (20%) 10 (100%) ethanol 70% 8 (80%) 2 (20%) 0 (0%) 10 (100%) propanol 70% 8 (80%) 2 (20%) 0 (0%) 10 (100%) total 35(50%) 27(38.6%) 8(%11.4) (100%)00 j bagh college dentistry vol. 26(1), march 2014 effect of disinfectant restorative dentistry 29 table 7 showed that mixing high concentrations of disinfectant agents (agno3, cuso4) with gypsum powder adversely affected the compatibility of type iv dental stone. none of the examined casts showed grade 4 surface quality. table 7: presents the results of chi-square analysis (the percentage values) of the surface detail reproduction of the control and the experimental groups. x2= 45.718, df=12, p-value = 0.000(hs), likelihood ratio= 54.179, df= 12, p-value= 0.000(hs) discussion in prosthodontics, objects potentially contaminated with pathogenic microorganisms are transported between dental laboratory and dental clinic. it has been claimed that to avoid cross contamination, specific disinfection measures should be followed. in the literature, the usual solution to this problem has been to chemically disinfect either the impressions or gypsum casts (1). in this study, gypsum specimens disinfected with either incorporation or immersion in disinfectant agents revealed the following results regarding the evaluated properties: setting time the time elapsing from the beginning of mixing until the material hardens is called the setting time; certain penetrometers are dependant for measuring setting time of gypsum products like gilmore needle and vicat needle (11). following ada specification no.25, the setting time was obtained using standardized vicat apparatus. regarding the result of this study it could be found that the disinfectant powders in the evaluated concentrations promoted a clear reduction in the vicat setting time in comparison to the control group, this can be explained that agno3 in high concentration increased the rate of dissolution of hemihydrates and subsequently made the hemihydrates more soluble. the setting reaction of gypsum products is affected by the type and the concentration of the chemical modifiers which are added within the gypsum materials, this finding is in agreement with hatim et al. (12) while the addition of cuso4 in low concentration (0.5%) has shown a greater reduction the setting time of dental stone in comparison to 1%, this could be explained that some modifiers in high concentrations may precipitate and poison the nuclei of crystallization either by reducing the rate of solubility of hemihydrates or by inhibiting the growth of dihydrate crystals (11). linear setting expansion the setting expansion of the dental stones is an important factor for many dental applications. the casts must have slightly larger dimensions to offset the impression material shrinkage and then ensure that the dental pieces are adequately manufactured, under ordinary conditions high strength dental stone has 0.08% to 0.10 % linear setting expansion (6,17). many factors may affect the setting expansion of gypsum products among them the technique of spatulation, condition of water (deionozed or not), the composition of the gypsum product (6). in this study, the addition of disinfectant powders in low concentrations to the dental stone or immersion of stone specimens in 70% propanol did not adversely affect the dimensional stability of dental stone, regarding the addition of disinfectant powders in high concentrations to the dental stone, the reduction in the linear setting expansion could be due to the changes in the morphology of the resulted gypsum crystals as a result to the disinfectant treatment and subsequently produce changes in the crystals thrust and tendency for expansion, this finding is in agreement with the finding of hatim et al. (12).while for stone specimens immersed in 70% ethanol for 15 minutes, the change in the linear setting expansion could be due to interaction between the solution and dental stone (22) also this finding is in agreement with sarma et al. (24) who found that immersion of groups rankings i ii iii total control 8 (80%) 2 (20%) 0 (0%) 10(100%) agno3 0.5% 7 (70%) 3 (30%) 0 (0%) 10(100%) agno3 1% 0 (0%) 4 (40%) 6 (60%) 10(100%) cuso4 0.5% 3 (30%) 6 (60%) 1 (10%) 10(100%) cuso4 1% 0 (0%) 6 (60%) 4 (40%) 10(100%) ethanol 70% 8 (80%) 2 (20%) 0 (0%) 10(100%) propanol 70% 8 (80%) 2 (20%) 0 (0%) 10(100%) total 34(48.6%) 25(35.7%) 11(15.7%) 70(100%) j bagh college dentistry vol. 26(1), march 2014 effect of disinfectant restorative dentistry 30 stone specimens 2% gluteraldehyde for 10-30 minutes showed negative shrinkage and relate the change to the erosion of the reproduced lines, surface erosion is perhaps the best measure of the reaction of the stone. immersion of stone specimens in 70% propanol for 15 minutes showed no statistical significant difference in comparison to the control group, this is similar to the study of abdelaziz et al. (15). compressive strength the strength of gypsum – based products is usually expressed in terms of compressive strength, which is directly related to the material's ability to fracture resistance when subjected to compressive tensions. thus the dental stone compressive strength is an important factor in the rehabilitation work in dentistry (13). in the set gypsum material, the number of crystals formed during setting and their inter-meshing and enlargement determines the strength. of the set material (14), the prepared dental stone specimens with the additives have shown a reduction in compressive strength in comparison to the control specimens, this could be either related to the presence of additional excess water in the mixture or to the decrease interaction (inter crystallization cohesion) between the gypsum crystals related to decreased amount of gypsum crystals as a result of increased concentration of additives in a given volume of gypsum material. 1% agno3 and 1% cuso4 produce great reduction in compressive strength than the control group and other experimental groups, this may be related to the increase in the rate of reaction so that some of the hemihydrates crystals does not get hydrated to form dihydrate crystals, this increase the un reacted hemihydrates contents in the materials and thereby produces a weaker product (13). detail reproduction the incorporation of disinfectant powders (agno3, cuso4) in high concentrations adversely affected the detail reproduction of stone cast, this could be due to several alteration in the crystals formed during the stone setting reaction or could be attributed to the change in the water requirement of dental stone as a result of incorporation of the disinfectant powders leading to change in the recommended consistency for satisfactory detail reproduction (13,16). the immersion of stone samples in 70% ethanol or 70% propanol for 15 minutes did not affect their surface detail reproduction; this finding is in contrast with sarma et al. (24) who found that immersion of stone specimens in 2% gluteraldehyde for 10-30 minutes showed alteration. gypsum compatibility with silicone impression materials mixing the dental stone with high concentrations of disinfectant powders did harm the compatibility of dental stone while 15 minute immersion of stone specimens in either 70% ethanol or 70% propanol did not affect the compatibility of dental stone ,this finding is in agreement with abbas and ibrahim (16) and marcos et al. (17) , it could be due to some kind of interaction of disinfectant powders with that of impression material leading to reduction in the sharpness of the line reproduced also could be due to low wetting behaviors of the disinfected dental stone against the surface of silicone impression material. as conclusion; within the limitations of this study, the newly introduced mixing method revealed that 0.5% silver nitrate powder as well as 15 minutes immersion of the set stone specimens in 70% ethanol or 70% propanol did not appear to have an adverse effect on the tested physical and mechanical properties references 1. hall bd, muñoz-viveros ca, naylor wp, jenny sy. effects of a chemical disinfectant on the physical properties of dental stones. int j prosthodont 2004; 17: 65–71. 2. amin wm, al-ali mh, al-tarawneh s, taha st, saleh mw, ereifij n. the effects of disinfectants on dimensional accuracy and surface quality of impression materials and gypsum cast. j clin med res 2009; 1(2): 81-9. 3. ada council on scientific affairs and ada council on dental practice. infection control recommendations for the dental office and the dental laboratory. j am dent assoc1996; 127: 672-80. 4. sanad me, combe ec, grant aa. the use of additives to improve the mechanical properties of gypsum products. j dent res 1982; 61: 808-10. 5. kotsiomiti e, pissiotis a, kalotannides a, diakoyiannimi. effects of the addition of ammonium salts on improved dental stones surface hardness. hellenic dent j 1995; 5: 45-50. 6. craig rg, power jm. restorative dental materials. 11th ed. mosby co.; 2002. p. 635-675, 392-404. 7. twomey jo. abdelaziz km, combe ec, anderson dl. calcium hypochlorite as a disinfecting additive for dental stone. j prosthet dent 2003; 90: 282-8. 8. donovan t, chee wwl. preliminary investigation of a disinfected gypsum die stone. j prosthodont 1989; 2 : 245-8. 9. ivanovskl s, savage nw, brockhurst ps, bird ps. disinfection of dental stone costs: anti microbial effects and physical property alteration dent mater1995; 11: 19-33. 10. infection control recommendations for the dental office and the dental laboratory. ada council on scientific affairs and ada council on dental practice. j am dent assoc 1996; 127: 672-80. 11. john j. manappallil. basic dental materials; 2007. p. 82-97. j bagh college dentistry vol. 26(1), march 2014 effect of disinfectant restorative dentistry 31 12. hatim na, al-khayat ik, abdullah ma. modification of gypsum products (part1): physical and mechanical properties of adding some additives on different types of gypsum products. al-rafidain dent j 2007; 7(2): 206-12. 13. matheus gl,sergio sn, rodrigo dp. effect of incorporation of disinfectant solutions on setting time, linear dimensional stability and detail reproduction in dental stone casts. j prosthodont 2009; 18: 521-6. (ivsl). 14. rajeshv, moftah ai, badr ai, mohammed he. compressive strength of gypsum product with various sulfates .cairo dent j 2008; 24(2):199-203. 15. abdelaziz km, combe ec, hodges js. the effect of disinfectant additives on the properties of the dental gypsum 1. mechanical properties. j prosthodont 2002; 11:161-7. 16. abbas sm, ibrahim ik. the effect of addition of calcium hypochlorite disinfectant on some physical and mechanical properties of dental stone. j bagh coll dentistry 2012; 24(sp.issue): 36-43. 17. marcos adb, rafael pv, simonides c, mario ac, marcelo fm, rafael lx. linear dimensional change, compressive strength and detail reproduction in type iv dental stone dried at room temperature and in a microwave oven. j app oral sci 2012; 20(5):1-7. 18. berko ry. effect of madacide disinfectant solution on some physical and mechanical properties of dental stone. a master thesis. college of dentistry, university of baghdad, 2001. 19. krishan m, chiramana s, swetha hb, anne g, prakash m, ravi rd. an evaluation of the effect of mixing disinfectant solutions on physical properties of die stone material. an in vitro study. indian j dent sci 2012; 4(5): 31-3. 20. jwad m, amer mkh. compressive strength and surface roughness of die stone cast after repeated disinfection with sodium hypochlorite solution. j bagh coll dentistry 2012; 22(3): 27-33. 21. suprano ms, kattadiyil mt, goodacree j, winer ms. effect of disinfection on irreversible hydrocolloid and alternative impression materials on the resultant gypsum casts. j prosthetic dentistry 2012; 108: 250-8. (ivsl). 22. abdullah ma. surface detail, compressive strength and dimensional accuracy of gypsum casts after repeated immersion in hypochlorite solution. j prosthet dent 2006; 95: 462-8 23. american dental association specification no.25 for dental gypsum products, 1973. p. 255-60. 24. sarma ac, neiman r. a study on the effect of disinfectant chemicals on physical properties of die stone. quintessence int1990; 21: 53-9. 26heba f.doc j bagh college dentistry vol. 28(3), september 2016 comparison of pedodontics, orthodontics and preventive dentistry 155 comparison of immunoglobulin iga level in the stimulated saliva of caries-free and caries-active children aged 7-10 years heba n. yassin, b.d.s., m.sc. (1) abstract background: salivary immunoglobulin iga plays an essential role in the immune response against dental caries. this studywas conducted to compare the salivary iga levels and flow rate of stimulated saliva in caries active and caries free children. materials and methods: the present study included sixty healthy children age 7-10 yearswho were divided into two groups. they were caries free and caries active children (30 children in each group). assessment and recording of caries – experience were through the application of decayed, missing and filled tooth index (dmft) and (dmft) index, for permanent and deciduous teeth respectively. after dental examination, stimulated saliva samples were collected from the subjects and performed under standard condition following instruction cited by tenovuo and lagerlof, and chemically analyzed for the detection of salivary immunoglobulin (iga).in addition, salivary flow rate for the children were evaluated. data was then statistically analyzed using spssversion 18. results: salivary iga levels were significantly higher in caries free children than caries active children and the flow rate were lower in caries active children in both gender as compared to caries free children. conclusions: within the limitation of this study, it can be concluded that that the flow rate and salivary iga levels of the whole stimulated saliva have some role in protection against dental caries. key words: caries active, caries free, salivary iga. (j bagh coll dentistry 2016; 28(3):155-158). introduction immunoglobulin a (iga) is predominantly released by common mucosal immune system in human body secretions including saliva. naturally occurring salivary iga antibodies against different streptococcal antigens are present in saliva and constitute major defensive actions against dental caries (1,2). the role of salivary immunoglobulin in the protection against dental caries has been investigated in several studies (3,4), but making this association would be complicated since there are different sampling methods, different criteria for patient group and different laboratory tests between the studies (5) and their control is impossible in any study. it has been claimed that the imbalances in levels of salivary immunoglobulinand physicochemical properties, may play an important role in the onset and development of dental caries (6, 7). there for, this studywas conducted with an aim to evaluation of the stimulated human whole salivary flow rate, and salivary iga levels in relation to dental caries among children with age group of 7-10 years. materials and methods this study was conducted in the department of pedodontics and preventive dentistry, college of dentistry, university of baghdad.sample collection was started at beginning of april 2015 till beginning of june 2015. (1) assist. lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad the study group includes 30 subjects (group i), matching with control group (group ii) by age. diagnosis and recording of dental caries were carried out according to the criteria of who (8). a total of 60 subjects were divided equally into two groups: group i – caries-active children having at least five clinical dmft/ dmft(4). group ii – caries-free children having no caries, dmft/ dmft = 0. exclusion criteria • patients who are physically and medically compromised and having history of antibiotics intake since past 1 month. • patients who have arrested carious lesions dental examination of tooth surfaces was carried out by using dental explorer and plane mouth mirror.after oral examination for children, stimulated saliva samples were collected from the children, and performedunder standard condition following instruction cited by tenovuo and lagerlof (9). immediately after collection of saliva, through five minutes and disappearance of the salivary foam, the salivary flow rate was expressed as ml/min. the salivary sample was centrifuged then the clear supernatants will be separated by micropipette and stored in a deep freeze till the time of salivary analysis for the detection of salivary iga levels for both groups. the salivary iga levels were determinedby radial immunodiffusion (10) method using immunodiffusion plate (rea milano, italy) .five j bagh college dentistry vol. 28(3), september 2016 comparison of pedodontics, orthodontics and preventive dentistry 156 microliter of sample was placed in each well of immune diffusion plates. these plates were incubated at room temperature for 72 hours. the salivary iga levels were calculated by using reference table given in the diffu-plate kit in which each diameter of the halo is associated a concentration. results the percentage of caries – free and caries active children by gender are manifested in table (1), this table demonstrates that girlsdisplayed the high percentage of caries – freeand caries active compared to boys. table (2) represents the comparison of salivary iga level measured in mg/dl and salivary flow rate measured in ml\min, among gender in both caries group, the results showthe mean salivary iga level in girls in caries-free group was more than caries-active groups with statically not significant difference (p> 0.05) also mean salivary iga levelin boys among caries-free group was more than caries-active groups but difference was statically significant (p<0.05). concerning salivary flow rate the result demonstrates thatcaries-free group was higher than caries-active groups in both gender and difference was statically highly significant (p= 0.00). the level of salivary iga in the caries free group was in higher mean value than the caries active group with statistical significant differences at p<0.05. in regarding salivary flow rate the result shows that statistically highly significant differences (p<0.01)between caries active and caries free with higher mean value for caries free group compared to caries active groupas showed in table (3). table 1: distribution of caries free and caries active children by gender table 2: salivary iga levels (mg/dl)and flow rate(ml/min)ofcaries free andcaries active childrenby gender gendervariables caries group n mean ±sd t-test p-value girls^ salivary iga caries free 18127.2928.14 1.54 0.13# caries active 19112.2231.33 salivary flow rate caries free 18 2.71 0.46 4.23 0.00** caries active 19 2.02 0.53 boys^^ salivary iga caries free 12130.5229.17 2.38 0.03* caries active 11103.7724.20 salivary flow rate caries free 12 2.95 0.54 4.93 0.00** caries active 11 1.83 0.55 ^=df=35, ^^=df=21, #=not significant at p>0.05, *=significant at p<0.05, **=highly significant at p<0.01. table 3: comparison for total sample ofsalivary iga mg/dl, salivary flow rate ml/min between caries active and caries free groups variables caries group n mean ±sd t-test^ p-value salivary iga caries free 30128.5828.10 2.65 0.01* caries active 30109.1228.78 salivary flow rate caries free 30 2.81 0.50 6.41 0.00** caries active 30 1.95 0.54 ^=df=58, *=significant at p<0.05, **=highly significant at p<0.01 discussion dental caries is infectious disease and accepts the hypothesis that some form of host immunity can regulate caries activity. if immunity can regulate caries activity then salivary iga might provide a clear correlation (11). in this study stimulated whole saliva was collected to determine the role of salivary iga in protection from dental caries. caries group genderno. % caries free boys 12 40.0 girls 18 60.0 total 30 100.0 caries active boys 11 36.7 girls 19 63.3 total 30 100.0 j bagh college dentistry vol. 28(3), september 2016 comparison of pedodontics, orthodontics and preventive dentistry 157 this study revealed thatsalivary iga levels were significantly higher in caries free children as compared to caries active children which is in agreement with study of cogul et al (12). this difference may be because greater number of cariogenic bacteria in whole saliva of caries active children which may due to low immune response among those children.the caries free children produced a greater amount of salivary iga antibodies to cariogenic bacteria in minor, submandibular, or sublingual salivary glands than caries active children(13).thus, it can be suggested that the secretory immune system provides local immune protection against cariogenic organisms in the oral environment and ultimately prevents dental caries (11). in contrast to our study, thaweboon et al. (14) found that the presence of dental caries was associated with an increase of total salivary iga. however, shifa et al. (4) found no correlation between dental caries and salivary iga levels. thisopposing results may be due to different criteria for patient selection, different sampling methods, and differentlaboratory tests used between the studies. also genetic cause may related with these different result. moreover, the level of salivary immunoglobulin may change depending upon the salivary flow rate, hormonal factors, emotional states, and physical activity, etc. (5). saliva effects caries attack mainly by its rate of flow. in this study, significant difference between caries activity and salivary flow rate were established. the salivary flow rate was decreased in caries-active children compared to caries-free children and statistically highly significant difference. a significant cariespreventive function of saliva is to dilute bacterial substrate (15).normal salivary flow rate (hydration status and stimulated saliva flow rate) imparts a strong protective influence against dental caries (16). similar results was seen in the study conducted by al-zahawi (17) and sakeenabi and hiremath (18).the result of this study is in contrast to studies conducted previously by sulliuan (19) and russel et al. (20) which showed no significant difference between the salivary flow rate and caries activity. the obtained results of this study show that salivary iga and flow ratehas a convinced relation with caries activity in children and act as markers of caries activity.physical activity of saliva (as flow rate) play an important role in oral health maintenance. also this study shows that any change in salivary iga level may affect in change in oral ecosystem which may lead to dental caries development. references 1. hu s, xie y, ramachandran p, ogorzalek loo rr, li y, loo ja, et al. large scale identification of proteins in human salivary proteome. proteomics 2005; 5:1714–28. 2. brandtzaeg p. do salivary antibodies reliably reflect both mucosal and systemic immunity? ann n y acad sci 2007; 1098: 288-311. 3. radhi nj, el-samarrai sk, alkhafaji jt. dental caries in relation to salivary parameters and immunoglobulins among down's syndrome children in comparison to normal children. j bagh coll dentistry 2009; 21(3):118-24. 4. shifa s, muthu ms, amarlal d, ratna p, prabhu v. quantitative assessment of iga levels in the unstimulated whole saliva of caries-free and cariesactive children. j indian soc pedod prevent dent 2008; 26:158-61. 5. michalek sm, katz j, childers nk, martin m, ballovetz df. microbial / host interaction: mechanism involved in host response to microbial antigens. immunologic res 2002; 26(1-3): 223-34. 6. parslow t, staties d, terr a, imboden j. medical immunology. 10th ed. lange medical book/ mcgrawhill medical publishing division; 2001. 7. holmgren j, czerkinsky c. mucosal immunity and vaccines. nature med 2005; 11(4 suppl): s45-53. 8. world health organization (who). basic methods of the oral health survey.3rd ed. geneva, 1987. 9. tenovuo j, legerlof f. saliva in: thylstup a, fejerskov o (eds). textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1996. 10. mancini g, carbonara ao, heremans jf. immunochemical quantitation of antigens by single radial immunodiffusion. immunochemistry 1965; 2: 235-39. 11. chawda jg, chaduvula n, patel hr, jain ss,lala ak. salivary siga and dental caries activity. indian pediatr 2011; 48(9): 719-21. 12. cogulu d, sabah e, kutukculer n, ozkinay f. evaluation of the relationship between caries indices and salivary secretory iga, salivary ph, buffering capacity and flow rate in children with down’s syndrome. arch oral biol 2006; 51: 23-8 13. doifode d, damle sg.comparison of salivary iga levels in caries free and caries active children. ijcds 2011; 2(1): 10-14. 14. thaweboon s, thaweboon b, nakornchai s, jitmaitree s. salivary secretory iga, ph, flow rates, mutansstreptococci and candida in children with rampant caries.southeast asian j trop med public health 2008; 39(5): 893-9. 15. lagerlof f, oliveby a, ekstrand j. physiological factors influencing salivary clearance of sugar and fluoride. j dent res 1987; 66:430-5. 16. chaudhary cp, pandey p, rao v, reddy nv, saxena a. estimation of salivary flow rate, ph, buffer capacity, calcium, total protein content and total antioxidant capacity in relation to dental caries severity, age and gender. contemporary clin dentistry 2015; 6(5): 65-71. 17. al-zahawi shm. the association between some salivary factors and dental caries in group of school children and adolescents in erbil city. zanco j med sci 2011; 15(2): 64-70. 18. sakeenabi b, hiremath ss. dental caries experience and salivary streptococcus mutans, lactobacilli scores, j bagh college dentistry vol. 28(3), september 2016 comparison of pedodontics, orthodontics and preventive dentistry 158 salivary flow rate and salivary buffering capacity among 6-year old indian school children.j intsoc prev community dent 2011; 1(2): 45-51. 19. sulliuan a. correlation between caries incidence and secretion rate, buffer capacity of stimulated whole saliva in 5-7 years old children matched for lactobacillus count and gingival state. swed dent j 1990; 14:131-5. 20. russel ji. macfarlance tw, aitchison tc, stephen kw, burchell ck. caries prevalence and microbiological and salivary caries activity test in scottish adolescent. community dent oral epidemiol 1990; 18:120-5. j bagh college dentistry vol. 26(1), march 2014 effect of certain restorative dentistry 53 effect of certain chemical surface treatments on repair bond strength of some denture base materials reem ahmed shihab, b.d.s. (1) basima m. a. hussein, b.d.s., m.sc., ph.d. (2) abstract background: fracture of different types of acrylic denture base is a common problem associated with dental prosthesis. studies suggested that the repair strength may be improved by several means including surface treatment with chemical agents. the aim of the study was to evaluate the effect of surface treatment with acrybond-bonding agent and monomer on fractured denture base in respect to transverse, tensile and shear bond strength and evaluation of the mode of failure by light microscope. materials and methods: two hundred seventy specimens were prepared and divided into 3 groups according to the material used (regular conventional, rapid simplified and high impact) heat cure acrylic. the specimen in each groups were prepared specifically according to testing (tensile, transverse and shear bond strength). all the specimens were stored in 37°c for 28days before fracture then the specimens in each test were divided into 3 groups according to surface treatment (control-without surface treatment, monomer(mma) group and acrybond (mma with acetone ))group. the specimens repaired with cold cure acrylic using ivomet; then stored in distill water at 37°c for 2days before testing. gefra universal testing machine was used and final load at fracture was recorded. results: monomer and acrybond group exhibited higher bond strength than control group. conclusion: the type of denture base affect the value of bond strength and the use of monomer or acrybond resulted in higher bond strength than untreated surface. key words: acrybond, mode of failure, denture repair. (j bagh coll dentistry 2014; 26(1):53-58). introduction the fracture of acrylic resin denture base material is a common clinical occurrence. fracture are more in the midline of maxillary complete denture (1,2). the fabrication of new denture is an expensive and time consuming procedure for this reason repair a denture is a common one (3) the ultimate goal of any acrylic denture repair is to restore the original strength of the fractured denture and avoid further fracture (1). various methods have been proposed for repairing fractured denture base, the use of autopolymerizing acrylic resin, allowing for simple and quick repair, is the most popular. successful denture repair relies on the phenomenon of adhesion. strong bonding of the repaired unit and reduce stress concentration. adhesion between denture base and repair materials can be improved by applying appropriate chemicals to the acrylic resin surfaces. these chemicals etch the surface by changing morphology and chemical properties of these materials (4). normally this change is obtained by wetting the surfaces with (mma). organic solvents such as acetone had also been used for this purpose. the present study was designed to evaluate the effect of 2 chemical solvents methyl methacrylate monomer and acrybond/ bonding agent which composed from (mma and acetone) on the (transverse, tensile and shear) bond strength of the repaired denture base material (regular conventional, rapid simplified and high impact) and using the light microscope to evaluate the mode of failure whether adhesive, cohesive or mixed. materials and methods 1metal pattern preparation: three different metal patterns were constructed according to the required tests as follow: a-for transverse bond strength test; rectangular specimen (65mm x 10mm x 2.5mm) (5). b-for tensile bond strength test; dumbbell specimen (60mm x 12mm x 3mm). c-for shear bond strength test which consist of 2 blocks each block were prepared with a dimension (70mm x 12mm x 12mm)(7) length, width and thickness respectively. 2silicon stone mould preparation: a-silicon mould preparation: to facilitate processing of testing, silicon mould was prepared by using a metal tray (figure l). (1)m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2)assistant professor. department of prosthodontics, college of dentistry, university of baghdad. j bagh college dentistry vol. 26(1), march 2014 effect of certain restorative dentistry 54 figure 1: metal tray b-investing procedure: silicon mould was poured with stone by using dental flask (figure 2). figure 2: silicone-stone mould all materials were manipulated and mixed according to manufacture instructions, then packing, curing, finishing and polishing according to the manufacture instructions and conditioned for 28days at 37°c(5). repair procedure for transverse and tensile bond strength test: with the aid of metal holding device the specimens were fractured with 45° bevel joint with a 3mm gap between fractured parts. the two parts of acrylic was repaired by (rapid repair/ densply) used as a repair material; mixed according to manufacture instructions then packing and curing by using (ivomet) for 15min. at 37°c and at pressure 301b/ inch2(8). after finishing and polishing the specimens were kept in the incubator and stored in distilled water at 37°c for 2 days. repair procedure for shear test: two specimens were adjusted together to test shear bond strength, this left a space between them filled with repair material. first specimen was adjusted the in a silicon mould then the lower half of giant flask filled with stone, before complete setting of the stone; the specimen with silicon mould were placed in the flask. then complete investing procedure for packing and curing in (ivomet) at 37°c and pressure 20ib/inch2 for 30 minutes (9), (figure 3). figure 3: specimen ready for testing preparation of the repaired acrylic specimens with surface treatment was applied on the repair joint before packing with cold cure acrylic, solvents were either: aa cry bond-bonding agent (vertex) which composed from (mma and acetone) was applied with cotton swap recommended by manufacturer instructions for 180 seconds before packing of cold cure acrylic (l0). bmonomer (mma) was applied with fine brush no. zero for 180seconds before packing cold cure acrylic (8). mechanical tests a-transverse bond strength test: a total of 90 specimens were prepared from the three types of heat cure acrylic materials with different surface treatment, the transverse strength was measured by universal testing machine, (figure 4) figure 4: universal testing machine by 3 points bending at cross head speed of (0.5mm/min), the value was computed by the following equation: s= 3pl/2bd5 s= transverse strength (n/mm2) p=peak load exerted on specimens (n) l=distance between supporting rollers (mm) b=width of the specimen (mm) d=depth of the specimens (mm) btensile bond strength test: the tensile bond strength of repaired specimen was measured by gefra universal testing machine at cross head speed (0.5mm/min) (figure 5). the value was computed by the following equation: t.s=f/a t.s=tensile strength (n/mm) f=force at failure (n) a=cross sectional area at failure (mm))11( cshear bond strength test: test was done by using gefra universal testing (figure 5) at cross speed (1 mm/min) j bagh college dentistry vol. 26(1), march 2014 effect of certain restorative dentistry 55 figure 5: gefra universal machine the value was computed by the following equation: b.s. = f/s b.s. = shear bond strength (n/mm2) f = force of failure (n) s = surface area of cross section (mm2) (ll) effect of surface treatments specimens were examined under light microscope (olympus) to study the effects of application of monomer and acrybond in comparison with non treated surfaces. mode of failure all the specimens were examined visually; this was repeated for all the tested materials under the three types of loading with and without surface treatments. results mean values, standard deviation and standard error of transverse test are presented in table(l). anova test was used to compare between the surface treatments for every test material. results of statistical analysis also presented in table 1 also presented in the tables. table l: descriptive data and statistical analysis of transverse bond strength test for the tested materials and surface treatment surface treatment descriptive statistics regular conventional rapid simplified high impact control group mean 63.60 86.40 73.44 sd 10.88 10.24 10.63 se 3.44 3.24 3.36 monomer group mean 90.96 94.32 102.00 sd 5.21 15.23 9.63 se 1.65 4.82 3.05 acrj'bond group mean 97.68 95.52 103.92 sd 12.43 12.15 7.74 se 3.93 3.84 2.45 f-test 32.57 1.52 32.91 p-value 0.000 0.237 0.000 significance h.s n.s h.s duncan’s test was used for further analysis to identify the significant surface treatment type in each denture base material regarding transverse bond strength. table 2: duncan test results for regular conventional and high impact heat cure acrylic of transverse bond strength test. type of surface treatments regular conventional heat cure acrylic high impact heat cure acrylic sig p-value sis p-value control & monomer s po.05 s. p<0.05 control & acrvbond n.s p>0.05 s. p<0.05 monomer & acrvbond n.s. p>0.05 n.s. p>0.05 table 3: descriptive data and statistical analysis between types of surface treatment regarding every denture base evaluating tensile bond strength test. surface treatment descriptive statistics regular conventional heat cure rapid simplified heat cure high impact heat cure control mean 11.11 18.38 21.00 sd 1.16 2.72 1.83 se 0.369 0.862 0.579 monomer mean 16.96 28.67 25.45 sd 1.24 2.20 1.24 se 0.393 0.696 0.393 acrybond mean 13.53 22.22 21.41 sd 2.57 2.42 3.71 se 0.814 0.768 1.17 f-test 27.30 27.30 27.30 p-value 0.000 0.000 0.000 significance h.s. h.s. h.s. duncan’s test was used for further analysis to identify the significant surface treatment type in each denture base material regarding tensile bond strength. table 4: duncan' s test result for the tested denture base materials of tensile bond strength test after surface treatments. types of surface treatments regular conventional heat cure acrylic rapid simplified heat cure acrylic high impact heat cure acrylic sig p-value sig p-value sig p-value control & monomer n.s p>0.05 s po.05 s po.05 control & acrvbond s po.05 s po.05 n.s p>0.05 monomer & acrvbond s po.05 s po.05 s po.05 j bagh college dentistry vol. 26(1), march 2014 effect of certain restorative dentistry 56 table 5: descriptive data of shear bond strength and anova test between surface treatments. surface treatment descriptive statistics regular conventional heat cure rapid simplified heat cure high impact heat cure control mean 3.258 3.02 1.762 sd 0.574 0.466 0.534 se 0.182 0.147 0.169 monomer mean 3.460 5.118 3.722 sd 0.462 . 0.474 0.382 se 0.146 0.150 0.121 acrybond mean 4.048 3.942 5.360 sd 0.713 0.723 0.421 se 0.225 0.229 0.133 f-test 4.81 34.37 160.04 p-value 0.016 0.000 0.000 significance s h.s h.s table 6: duncan test result for tested materials regarding shear bond strength with and without surface treatment. types of surface treatments regular conventional heat cure acrj'iic rapid simplified heat cure acrylic high impact heat cure acrylic sig p-value sig p-value sig pvalue control & monomer n.s px).05 s po.05 s po.05 control & acrybond s po.05 s po.05 s po.05 monomer &acrybond s po.05 s po.05 s po.05 effect of surface treatment: under light microscope the joint of the fractured surfaces after treatment with monomer for (180) seconds appear porous compared with untreated joint which almost smooth with no channels (figure 6,7). the joint that treated with acrybond showed more porous than monomer surface treatment (figure 8). figure 6: control (x4). figure 7: monomer surface treatment (x4). figure 8: acrybond surface treatment(x4). mode of failure: the specimens were examined under light microscope to determine the mode of failure. most of untreated specimens exhibited adhesive type of failure. after treatment with monomer and acrybond the mode of failure was changed to cohesive and mixed type in all the tested denture base materials under different types of loading. discussion transverse bond strength test in this study the high impact denture base acrylic resin exhibited the highest mean value then followed by rapid simplified and the lowest was regular conventional . this result were due to too rapid arise in the processing temperature produces a large numbers of radicals and result many growing polymer chains, producing an increase in branching and cross linking of the interstitial polymer. the result are in agreement with meng and latte (12) who found that there were high significant difference in the flexural strength observed between high impact polymer and conventional heat cure denture base. for surface treatment the application of monomer for 180 seconds improved the transverse bond strength test and this agree with abu-anzeh and abdul hadi (8) who stated that wetting the fracture site with monomer before repair will increase transverse bond strength test. while acrybond which dissolve away most of the micro debris and smooth out the adhesive surface and create a sponge like structure and increase bond strength. our result agree with vojdani et al (,3) who studied the effect of chemical etchants mma and acetone on repaired' denture base and found that the transverse bond strength test of repair material to denture base resin increased significantly with chemicals but there no statistically difference between mma and acetone. j bagh college dentistry vol. 26(1), march 2014 effect of certain restorative dentistry 57 tensile bond strength test: in this study the highest mean value was recorded by rapid simplified then high impact and the lowest was for conventional type. these finding suggest that the methods of polymerization recommended by the manufacture of these acrylic resins resulted in a more stable bond. our finding agree with vallitu (14) who concluded that the bond of heat polymerizing as well as auto polymerizing base resins to acrylic teeth is satisfactory. for surface treatment the application of monomer for 180 seconds improved the tensile bond strength test by dissolving the outer layer of pmma. it also improved the adhesion between repaired material and denture base by formation of interwoven polymer network. this was supported by stoia et al (,5). for acrybond application also was improved tensile bond strength which supported with result of sulaiman (10) who found that there was significant improvement in bond strength when using these materials. indicating that the acrybond is active bonding agent at repaired denture base and these chemicals etch the surface by changing the morphology and chemical properties of the materials. shear bond strength test: in this study the result demonstrated that high impact heat cure denture base showed the highest mean value followed by rapid simplified and the lowest was regular conventional heat cure denture base. this result may be due to the higher polymerization temperature resins enhances the diffusion of monomer of denture base resin into the acrylic resin polymer and further monomer to polymer conversion (16). our results agree with saaverda et al (17) whom observed similar result. for surface treatment the application of monomer for 180 seconds improved the bond strength in all types of acrylic resin. this can be discussed as the chemical surface treatments cause superficial crack propagation as well as the formation of numerous pits approximately 2 um in diameter (18) acrybond application improved bond strength, it dissolve away and smooth out the adhesive surface and produce sponge like structure which enhance the mobility of monomer units mixed with acetone and form denture base leading to an increase in the number of active sites and then there will be physical interaction (vander waal force). this explanation agrees with sulaiman (l0). result from visual examination under light microscope showed high percentage of adhesive failure for untreated repaired specimen indicating the bond failed at the interface of the fractured surface and repaired material. this was agreement with abdul hadi (8). after surface treatment of the fractured ends showed high percentage of cohesive and mixed failure indicating that a strong bond was formed between repaired joint and repaired material thus rendering the fracture to be either through original acrylic specimens or repaired material. our finding was agreement with the result of rached and del-bel cury (4) and abdul-hadi (8). references 1stipho hd. repair of acrylic resin denture base reinforced with glass fiber. j prosthet dent 1998; 80: 540-50. 2stipho hd, stipho as. effectiveness and durability of repaired acrylic resin joints. j prosthet dent 1987; 58: 249-53. 3sarac sy, sarac d, kulunk t, kulunk s. the effect of chemical surface treatments of different denture base resins on the shear bond strength of denture repair. j prosthet dent 2005; 94(3): 259-66. 4rached rn, del bel cury a a. heat-cured acrylic resin repaired with microwave one: bond strength and surface texture. j oral rehabil 2001; 28: 370-5. 5ada: american national standers institute/ american dental association specification no. 12 for denture base polymer. 1999; 10th ed.; chicago: council on dental material and devices. 6iso 527. international organization for standardization. plastic determination of tensile properties. 1993. 7al-azawi rw. evaluation of some mechanical properties of soft liner. college of dentistry. university of baghdad, 2008. 8abdul-hadi n.f. the effect of fiber reinforced and surface treatment on some of the mechanical properties of the repaired acrylic denture base materials (a comparative study) college of dentistry. university of baghdad, 2007. 9memarian m, shayestehmajd m. the effect of chemical and mechanical treatment of the denture base resin surface on the shear bond strength of denture repairs. rev clin pesq odontol; 2009; 5(1):11-7. 10sulaiman sa. bonding strength between acrylic teeth and different types of acrylic denture base material. college of dentistry. university of baghdad, 2012. 11craig rg, powers jm. restorative dental materials. 11th ed. st. louis: mosby co.; 2002. p.195. 12meng tr, latte m.a. physical properties of four acrylic denture base resin. j cont dental pract 2005; 6(4): l-5. 13vojdani m, rezaei s, zareeian l. the effect of chemical surface treatment and repair material on transverse strength of repaired acrylic denture resin. indian j dent res 2008; 19(l): 2-5. 14vallitu pk. fracture surface characteristics of damaged acrylic-resin based dentures as analyzed by sem replica technique. j oral rehabil 1996; 23: 5249. 15stoia ae, sinescu c, pielmusi m, enescu m, tudor a, rominu ro, rominu m. tensile testing a method used to demonstrate the effect of organic solvents on acrylic teeth denture base resin bond strength. int j bio and biom eng 2011; 1(5): 9-17. 16lamb dj, ellis b, priestley d. the effects of process variables on levels of residual monomer in j bagh college dentistry vol. 26(1), march 2014 effect of certain restorative dentistry 58 autopolymerizing dental acrylic resin. j dent 1983; 11(1): 80-8. 17saaverda g, valadro lf, amaral r, ozcan m, bottino ma. bond strength of acrylic teeth to denture base resin after various surface conditioning methods before and after thermocycling. int j prosthet 2007; 20:199-201. 18anusavice kj. philip’s science of dental materials. 11th ed. saunders/elsevier; 2008. p.163-165. ghada f.doc j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry104 effect of small cardamom extracts on mutans streptococci and candida albicans in comparison to chlorhexidine gluconate and de-ionized water (in vivo study ) ghada a. ibrahim, b.d.s. (1) wesal a. al – obaidi, b.d.s., m.sc. (2) abstract background: small cardamom or green cardamom is the dried fruit of the tall perennial herbaceous plant, elettaria cardamomum maton belonging to the family zingiberaceae. the major use of small cardamom on world wide is for domestic culinary purpose and in medicine. this study was conducted to test the effect of small cardamom extracts on mutans streptococci and candida albicans in comparison to 0.2% chlorhexidine gluconate and de-ionized water in vivo. materials and methods: mutans streptococci and candid albicans were isolated, purified and diagnosed according to morphological characteristic and biochemical test. in this experiments, the effect of control agents and small cardamom extracts as a mouth rinses was tested on the saliva of group of volunteers to determine the level of mutans streptococci and candida albicans in vivo. also the salivary flow rate and ph were measured in vivo. result: 10 % aqueous cardamom extracts had a highly significant antimicrobial activity against mutans streptococci after 15 min after rinsing and following times. 30 % aqueous cardamom extracts had a significant antifungal activity in vivo against candida albican after 30 min after rinsing and following times. but still chx is more effective than the other agents in reduction the counts of mutans streptococci and candida albicans. chx 0.2% mouth rinse had the highest stimulation of salivary flow rates and ph followed by hot water cardamom mouth rinse 30% followed by cold cardamom mouth rinse 10% then de-ionized water mouth rinse. conclusion: cardamom extracts were effective against mutans streptococci and candida albicans, but still less than chx. keywords: mutans streptococci, candida albicans, small cardamom, chlorhexidine, de-ionized water. (j bagh coll dentistry 2013; 25(4):104-108). الخالصة إن االستخدام الرئیسي للھیل على النطاق العالمي ھو .یعود إلى العائلة الزنجبیلیةالھال ماتون , مةالھیل الصغیر او االخضر ھو ثمرة مجففة لنبات عشبي معمر طویل القا: المقدمة كلوروھكسیدین % 0.2أجریت ھذه الدراسة الختبار تأثیر مستخلص الھیل األخضر على نمو بكتریا المیوتانز وفطر المبیضات بالمقارنة مع .لإلغراض الطھي المحلیة وفي الطب .نیت والماء الغیر ایونيكلوكو في ھذة التجربة تم اختبار تأثیر المواد .تم تنقیة و تشخیص بكتریا المكورات المسبحیة المیوتانز و فطر المبیضات حسب الصفات الشكلیة و اختبارات الكیمیاء الحیاتیة :المواد والعمل كذلك تم قیاس إفراز وقاعدیة اللعاب, ن لتحدید مستویات بكتریا المكورات العقدیة المیوتانز وفطر المبیضاتالضابطة و مستخلص الھیل األخضر كغسول فم على مجموعة من المتبرعی .سریریا لمضمضة بھ واألوقات دقیقة من ا 15سریریا لھ فرق إحصائي عالي في تقلیل النمو الحیوي للبكتریا مقارنة بالماء الغیر االیوني بعد % 10مستخلص الھیل المائي بتركیز .: النتائج دقیقة من المضمضة بھ واألوقات 30سریریا لھ فرق إحصائي في تقلیل النمو الحیوي لفطر المبیضات مقارنة بالماء الغیر االیوني بعد % 30مستخلص الھیل المائي بتركیز . التالیة .كتریا المكورات المسبحیة وفطر المبیضاتكلورھكسدین كلوكونیت اكتر فعالیة في تقلیل النمو الحیوي لب% . 0.2 .التالیة .كلورھكسدین كلوكونیت% 0.2ان مستخلص الھیل كان فعاال ضد بكتریا المیوتانز وفطر المبیضات ولكن اقل تأثیرا من: االستنتاج ء الغیر ایونيالما, الكلورھكسدین كلوكنیت, الھیل االخضر, فطر المبیضات, المكورات المسبحیة المیوتانز :كلمات مفتاحیھ introduction dental caries is a dynamic process of demineralization of the dental hard tissues by products of bacterial metabolisms, alternating with periods of remineralization (1). mutans streptococci were found to be the predominant bacteria in caries process (2-4). different epidemiological and experimental studies showed a positive association between mutans streptococci with initiation of carious lesion (2,4-6). c. albicans is the most common fungal pathogen in humans. c. albicans can also act as an opportunistic pathogen with the ability to cause a variety of infections (7). some studies even have shown a significant association between c. albicans and dental caries in children and young (8,9). colonization of the oral cavity by c. albicans involves adherence of yeast cells to oral surfaces (10). (1) msc student, department of pedodontics and preventive dentistry, college of dentistry, baghdad university (2) professor, department of pedodontics and preventive dentistry, college of dentistry, baghdad university treatment of dental caries and periodontal diseases need a lot of as cost as well manpower. prevention, including use of chemical therapies, is more cost effective as patient shifts from high risk to low-risk level (11). chlorhexidine is very potent chemo-prophylatic agent (12). it has abroad spectrum action especially against mutans streptococci group and candida albicans (12,13). but it has many side effects (12). small cardamom or green cardamom, popularly known as ‘queen of spices’, is the dried fruit of the tall perennial herbaceous plant, elettaria cardamomum maton belonging to the family zingiberaceae. the major use of small cardamom on world wide is for domestic culinary purpose and in medicine. the aroma and medicinal properties of cardamom are due to the volatile oil present in it (14).there are very little exclusive studies about small cardamom antibacterial effect on mutans streptococci and candida albicans. for all of the above this study was conducted. j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry105 materials and methods small cardamom fruits were obtained from al-shoorga market. for mutans streptococci we used cold water extract by disolve100 grams of fruit powder of cardamom in 1000ml cold sterile distilled water and left undisturbed for 24 then filtered (15).the filtered extract was concentrated under vacuum below 40oc using a rotaevaporator. the weight of the solid residue was recorded and taken as the yield of crude extract (16). for candida albicans, we use hot water extract by dissolve 100grams of fruit powder of cardamom in 1000ml of sterile hot distilled water. the extract left for 48hr at room temperature then centrifuged at 2000 rpm for 10 min, then filtered. the extract was incubated at 37c until it became dry and stored in sterile screw capped vials in the refrigerator until needed (17). stimulated saliva was collected from ten healthy looking students from university of al-mustansiriya aged (18-22) from which mutans streptococci and candida albicans were isolated, purified, and diagnosis according to morphological, microscopical, biochemical test and by vitek2 test. the total number of volunteers were 24 and they were divided into 4 groups (each group was made up of 6 volunteers), the first group is the experimental group they used the water cardamom extract mouth rinse 10%, the second group is the experimental group they used the water cardamom extract mouth rinse 30 %, the third group used chx 0.2% mouth rinse as control positive and the fourth group used de-ionized water mouth rinses as control negative. procedure: 1.10 ml of 10%, 30% water cardamom extract, deionized water, and chlorhexidine gluconate 0.2% mouth wash were prepared. 2.stimulated saliva was collected by chewing a piece of arabic gum (0.5 gm) for 1 minute and then expectorate to remove all saliva then chewing a piece of gum (0.5 gm) for 1 minute and collecting the saliva in screw capped bottles(18). each participant was asked to rinse with aqueous solution for 1 minute, and then expectorate, stimulated salivary samples were recollected after 1 minute, 15minutes, 30 minutes, and 1 hour, during this time volunteers were asked not to eat or drink anything except water. within less than 15 minutes, the ph of saliva was measured by the digital ph meter; also the volume of saliva was measured also. sample of saliva were processed immediately, they were dispersed for 1 minute by vortex mixer, then 0.1 ml of saliva transferred to 0.9 ml of pbs, tenfold dilutions were performed. from the dilution 10-3, 0.1 ml was taken and spread in duplicate on the surface of msb and sda agar plates, then incubated anaerobically for 48 hr at 37 oc, and aerobically for 24 hr at room temperature. results mean counts of bacteria was estimated before and after rinsing with water extract 10%, chx gluconate, de-ionized water. chx had the maximum reduction in the bacterial viable counts followed by water cardamom extracts 10% while de-ionized water had the least reduction of bacterial counts among the agents as in table (1). anova test was used to examine the difference among the mutans streptococci viable counts for the three mouth rinses at 5 time intervals. there no significant difference was found before rinsing while a significant difference after one minute of rinsing and a highly significant differences was found for the rest time point (table1).mean counts of c. albicans was estimated before and after rinsing with water extract 30%, chx gluconate, and de-ionized water. chx had the maximum reduction in the candida counts followed by water cardamom extracts 30% while de-ionized water had the least reduction of candida counts among the agents as in table (2). anova test was applied to examine the difference among the candida albicans for the three mouth rinses at 5 time intervals. there were no significant differences before rinsing and after one minute and 15 minutes of rinsing while highly significant differences were found for the rest time point (table 2). salivary flow rate was increased immediately after rinsing for the four mouth rinses, rinsing with chx and both cardamom extracts results in marked increased in the mean values of flow rates immediately after rinsing which continue for half an hour then started reduction (table 3). salivary ph was increased immediately after rinsing for the four mouth rinses, rinsing with both cardamom extracts result in marked increased in the mean values of salivary ph immediately after rinsing which continue for half an hour then started reduction (table 4). chx 0.2% mouth rinse had the highest stimulation of salivary flow rates and ph followed by hot water cardamom mouth rinse 30% followed by cold cardamom mouth rinse 10% then de-ionized water mouth rinse. alcoholic extract cause burning and discomfort of the mouth and the volunteers couldn't tolerate it. therefore only water extract were used in vivo study. j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry106 discussion aqueous extract of cardamom 10% was tested for its effects on mutans streptococci colony forming unit counts among group of volunteers in comparison to de-ionized water and chx. cardamom extract had highly significant antimicrobial activity against mutans streptococci as it can reduce the viable count of the bacteria profoundly in comparison to de-ionized water after 15 min after rinsing and following times. the reduction in the counts of the bacteria after 15 minutes after rinsing may be explained by the assumption that mutans streptococci were sensitive to the antibacterial compounds present in cardamom extracts which continue to release in mouth after rinsing. while still chx is more effective than the other agents in reduction the mutans streptococci, this could be due to chx having a prolonged bacteriostatic action and ability to adsorb into pellicle coated enamel surface and dental plaque during rinsing (19).aqueous extract of cardamom 30% was tested for its effects on c. albicans colony forming unit counts among group of volunteers in comparison to de-ionized water and chx. cardamom extracts had a significant antifungal activity against c. albicans as it can reduce the viable count of the candida profoundly in comparison to de-ionized water after 30 min after rinsing and following times. many studies confirmed antifungal efficacy of small cardamom on c.albicans (20-22). the antifungal activity of small cardamom on c. albicans is due to volatile oils whose main constituents are cineole, terpinol, and limonene (21). but still chx is significantly more effective than the other agents in reduction the counts of candida albicans. salivary flow rates and ph increased immediately after rinsing for two cardamom mouth rinses which continue to increase for half an hour then gradually decreased to approximate the baseline after one hour. chx 0.2% mouth rinse had the highest stimulation of salivary flow rates and ph followed by hot water cardamom mouth rinse 30% followed by cold cardamom mouth rinse 10% then de-ionized water mouth rinse. references 1. harris o, christen g. primary preventive dentistry. 4th ed. appleton and lange; 1995. pp.40-54. 2. al-mizrakchi a. adherence of mutans streptococci on the teeth surfaces: microbiological and biochemical studies ph.d. thesis, university of al-mustansiriya, 1998. 3. balakrishnan m, simmonds r, taggt t. dental caries is a preventable infectious disease. aust dent j 2000; 45(4): 235-45. 4. sulaiman a. quantitative measurement of urea content in saliva, acquired pellicle and dental plaque in relation to dental caries susceptibility in human adults. ph.d. thesis, college of dentistry, university of baghdad, 2000. 5. al-ubaidia a. the prevalence of streptococcus mutans biotypes among preschool children. master thesis, college of dentistry, baghdad university, 1993. 6. el-samarrai s. major and trace elements contents of permanent teeth and saliva, among a group of adolescents, in relation to dental caries, gingivitis and mutans streptococci (in vitro and in vivo study). ph.d. thesis, college of dentistry, baghdad university, 2001. 7. pappas pg, rex jh, sobel jd, filler sg, dismukes we, walsh tj, edwards je. guidelines for treatment of candidiasis. clin infect dis 2004; 38(2):161-89. 8. beighton d, ludford r, clark d, brailsford r, pankhurst c, tinsley g, fiske j, lewis d, daly b, khalifa n, marren v, lynch e. use of chromagar candida medium for isolation of yeast from dental samples. j clin microbiol 1995; 33(11): 3025-7. 9. de carvalho fg, silva ds, hebling j, spolidorio lc, spolidorio dm. presence of mutans streptococci and candida spp.in dental plaque/dentine of carious teeth and early childhood caries. arch oral biol 2006; 51(11): 10248. 10. cannon rd, nand ak, jenkinson hf. adherence of candida albicans to human salivary components adsorbed to hydroxylapatite. microbiol 1995; 141 (1): 213–9. 11. tandon s, gupta k, rao s, malagi k. effect of triphala mouth wash on the caries status. int j ayurveda res 2010; 1(2): 93–9. 12. pourabbas r, delazar a, chistsaz m. the effect of german chamonile mouthwash on dental plaque and gingival inflammation. iranian j pharm res 2005; 2:105-9. 13. fedele d, niessan l. periodental treatment for older adult. in: newman m, takei h, carranza f (eds.) carranza's clinical periodontology. 2nd ed. philadelphia, w. saunders, 2002. 14. marongiu b, piras a, porcedda s. comparative analysis of the oil and supercritical co2 extract of elettaria cardamomum (l.) maton (cardamom). j agric food chem 2004; 52(20): 6278-82. 15. ogundiya m, okunade m, kolapo a. antimicrobial activities of some nigerian chewing sticks. ethnobotanical leaflets 2006; 10: 265-71. 16. bag a, bhattacharya s, bharati p, pal n, chattopadhyay r. evaluation of antibacterial properties of chebulic myrobalan (fruit of terminalia chebula retz.) extracts against methicillin resistant staphylococcus aureus and trimethoprimsuphamethoxazole resistant uropathogenic escherichia coli. afr j plant sciences 2009; 3(2): 25-9. 17. chevalier a. the encyclopedia of medicinal plants. london: dorling kindersley limited; 2003. pp.290. 18. thylstrup a, fejerskov o. clinical and pathological features of dental caries. in: thylstrup a, fejerskov o (ed.) textbook of clinical cariology. 2nd ed. copenhaen: munksgaard; 1996. pp. 111-48. 19. aznita w, abidin z, aznan e, razi m. the effectiveness of chlorhexidine, hexetidine and eugenia caryophyllus extracts in commercialized oral rinses to j bagh college dentistry vol. 25(4), december 2013 effect of small cardamom pedodontics, orthodontics and preventive dentistry107 reduce dental plaque microbes. res j bio sci 2009; 4(6):716-9. 20. aneja k, radhika j. antimicrobial activity of amomum subulatum and elettaria cardamomum against dental caries causing microorganisms. j ethnobotanical 2009; 13:840–9. 21. al-hussaini j, al-mohana m. an evaluation of the antifungal activity of some local medicinal plants against growth of candida albicans in vitro. alqadisiya j vet med sci 2011; 9 (2): 60-8. 22. rezooqe s, kadhum s, al sadik s. antifungal efficiency of miswak and cardamom extract on some virulence factors of candida albicans as oral pathogen. biology j al kufa university 2011; 3(2): 297-303. table 1: mean and standard deviation of msx104 of three mouth washes in vivo. time agents no. mean ± sd f p description base chx 6 268.5 19.68 3.059 0.077 ns d.w. 6 268.0 24.65 w.e. 10% 6 234.0 36.13 1 min chx 6 204.83 29.56 4.778 0.025 s d.w. 6 254.17 21.48 w.e. 10% 6 213.66 35.65 15 min chx 6 154.83 26.69 18.902 0.000 hs d.w. 6 245.0 15.42 w.e. 10% 6 196.33 31.44 30 min chx 6 116.33 22.09 49.363 0.000 hs d.w. 6 253.83 25.65 w.e. 10% 6 179.0 24.11 1 hr chx 6 95.67 11.29 89.017 0.000 hs d.w. 6 259.17 27.49 w.e. 10% 6 192.83 21.99 d.f=2 table 2: mean and standard deviation of c. albicansx102 of three mouth washes in vivo. time agents no. mean ± sd f p description base chx 6 14.33 5.12 0.658 0.532 ns d.w. 6 11.16 3.71 w.e.30% 6 13.16 5.49 1 min chx 6 8.16 4.16 0.299 0.746 ns d.w. 6 9.66 3.50 w.e.30% 6 9.66 3.93 15 min chx 6 4.66 2.73 2.344 0.130 ns d.w. 6 8.16 3.12 w.e.30% 6 6.50 2.50 30 min chx 6 2.83 2.31 9.121 0.003 hs d.w. 6 9.00 3.16 w.e.30% 6 4.83 2.04 1 hr chx 6 1.83 2.04 12.980 0.001 hs d.w. 6 9.83 3.18 w.e.30% 6 5.66 2.80 d.f=2 pedodontics, orthodontics and preventive dentistry 108 table 3: mean and standard deviation of salivary flow rate before and after small cardamom, chx and d.w mouthwashes. time agents no. mean ± sd f p description base chx 6 3.43 0.34 0.504 0.684 ns d.w. 6 3.30 0.33 w.e. 10% 6 3.45 0.50 w.e 30% 6 3.21 0.33 1 min chx 6 3.71 0.27 1.552 0.232 ns d.w. 6 3.38 0.31 w.e. 10% 6 3.60 0.43 w.e. 30% 6 3.38 0.24 15 min chx 6 3.90 0.23 3.147 0.048 s d.w. 6 3.43 0.28 w.e. 10% 6 3.71 0.38 w.e. 30% 6 3.51 0.21 30 min chx 6 4.16 0.28 9.301 0.000 hs d.w. 6 3.40 0.21 w.e. 10% 6 3.83 0.27 w.e. 30% 6 3.68 0.24 1 hr chx 6 4.11 0.27 9.051 0.001 hs d.w. 6 3.36 0.23 w.e. 10% 6 3.73 0.21 w.e. 30% 6 3.58 0.29 d.f=3 table 4: mean and standard deviation of salivary ph before and after cardamom extracts, chx and d.w mouth washes. ph agents no. mean ± sd f p description base chx 6 7.14 0.10 1.114 0.367 ns d.w. 6 7.12 0.10 w.e. 10% 6 7.05 0.07 w.e. 30% 6 7.13 0.09 1 min chx 6 7.30 0. 09 4.599 0.013 s d.w. 6 7.17 0.08 w.e. 10% 6 7.13 0.05 w.e. 30% 6 7.25 0.10 15 min chx 6 7.42 0.09 9.252 0.000 hs d.w. 6 7.22 0.08 w.e. 10% 6 7.20 0.06 w.e. 30% 6 7.35 0.09 30 min chx 6 7.60 0.07 34.633 0.000 hs d.w. 6 7.20 0.09 w.e. 10% 6 7.25 0.04 w.e. 30% 6 7.44 0.08 1 hr chx 6 7.66 0.07 47.053 0.000 hs d.w. 6 7.16 0.09 w.e. 10% 6 7.21 0.05 w.e. 30% 6 7.39 0.09 d.f=3 ibrahim final.doc j bagh college dentistry vol. 26(2), june 2014 radiographic follow up up restorative dentistry 7 radiographic follow up for clinical cases of mandibular implant retained overdenture mir-od raghdaa k. jassim, b.d.s., m.sc., ph.d. (1) ibrahim k. ibrahim, b.d.s., c.e.s., d.s.o. (2) abstract background: the use of osseointegrated fixtures in dentistry has been demonstrated both histologically and clinically to be beneficial in providing long term oral rehabilitation in completely edentulous individual. most patients suffer from denture instability; particularly with mandibular prosthesis, the use of dental implant will be benefit significantly from even a slight increase in retention. the concept of implanting two to four fixtures in a bony ridge to retain a complete denture prosthesis appealing therefore, as retention, stability and acceptable economic compromise to the expanse incurred with the multiple fixture supported fixed prosthesis . materials and methods in this study the sample were eight patients selected from a hospital of specialized surgery, these patient were wearing a mandibular implant retained over denture for two years these patients having mir-od with bar-clip, ball-cup and oring attachments. preparative radiography was obtained for this patient from the center .these radiograph was taken to the patient at time of insertion. the second radiograph image was taken to the patient after two years of function with prosthesis. .the scanned images were transfer to special folder in a computer then analysis of bone loss done using dimax software. after that an accurate calibrations of crestal bone measurement were analyzed for both groups of radiography . results it was appeared that the amount of bone loss in ball and bar designs (of mandibular implant retained overdenture) were within the criteria of successful rate of bone loss during the period of examination, and there was statistically significant difference between both types of anchorage system. conclusions the amount of bone loss was 0.1 mm after two years follow up, and it was within the acceptable limits of bone lose. a significant difference appeared between both designs of mir-od, ball and bar designs. key words: radiograph, implant, overdenture, dimax. (j bagh coll dentistry 2014; 26(2): 7-11). introduction mandibular implant-retained overdentures are generally anchored by at least two implants placed in canine or slightly medial to it (1,2).the most commonest forms of anchorage system are ball attachment (3) and two clips on bar connecting the implants (4). early crestal bone loss around dental implant supporting mandibular implant retained overdenture is a common finding .radiographic evaluation has been made especially after a period of function with prostheses, this will provide useful information in providing dental implant and treatment. several studies conducted to study the amount of bone loss around dental implant mesially and distally (58). this study aimed to radiographically evaluated bone loss after two years of function with mandibular implant retained overdenture. materials and methods sample the sample was collected from the maxillofacial surgery unit at specialized surgeries hospital. there is about twenty five patient who received mir-od treatment from the first time starting dental implant treatment at this center (2000 till -2005). (1)assistant professor (ph.d. student during the research) department of prosthodontics. college of dentistry, university of baghdad. (2)retired professor. since the patients did not follow their treatment only in case of pain or fracture of the attachment and with circumstance of country and difficulty of contact at that time in 2005 so our sample were eight patient only who they were wearing and functioning with mir-od for a period of two years. the patients were received mir-od with bar-clip, ball-cup and oring attachments. preparative radiography was obtained for this patient from the center; this radiograph was taken to the patient at time of insertion. the present study was designed to take another radiographic image after two year functioning with mir-od. then accurate calibrations of crestal bone loss measurement were analyzed for both groups of radiography. methods radiographic procedure in this step standardized procedure were followed in order that a high level of standardization of the radiograph will be obtained. panoramic radiographic digitization each radiograph was subjected to image scanning and setting using the (-ve) scanner″ these scanned radiographs were stored in a special folder in a computer for making the measurements. dimax software version 2000 was set up in the computer for starting measurement. j bagh college dentistry vol. 26(2), june 2014 radiographic follow up up restorative dentistry 8 measurements standardization procedures are essential in any research work .an intra and inter calibration was done priors starting the measurement procedure. the results obtained from intra and interexamination calibration study indicated acceptable measurement error, the standard deviation for radiographic examiner was nonsignificant. for panoramic radiograph which had an enlarged image so it is necessary to calibrate the bone loss in actual condition from that at the radiographic measurement specially when the radiographic image have an enlarged image of landmarks particularly bone and dental implant so during measurements there must be a guide of known size of implant in actual condition to have idea about the magnification in the radiograph, then measurements of the bone loss adjacent to the dental implant at the mesial and distal sites of four dental implants supporting mirod were done. the first step was measurement of dental implant from the apex of dental implant to the point of bone implant interface is calibrated using the known actual dental implant length ,then measurements of bone loss was performed. vertical measurements of bone level adjacent to the implant were made at time of insertion of mir-od as a base line measurements were established so that any changes in bone level at next appointment can be accounted (3) as shown in figure 1. statistical analysis statistical analysis of data were employed through the use of mann-whitney test which is a sensitive test in detecting true differences between especially small samples; it is mainly used for independent measures (9). figure 1: picture of radiograph in dimax program results analysis of data was done using mannwhitney test. this test depends on listing of the measurement in an ascending order and then the median value of these measurements was selected. descriptive statistic of patients' number and median values of bone loss measurements in mm for both ball and bar designed mir-od at time of insertion and functioning time was listed in table (1) and (2). in table (1), it was appeared that the higher median value of bone loss lies at the distal side of mesial implant supporting bar designed mir-od at time of insertion. the results in table (2) appeared that the higher median value of bone loss (2.5mm), this value was appeared at the distal side of the mesial implant statistical analysis of median bone loss value was applied, comparison between two designed of attachments ball and bar was observed in table (3) and (4). in table (3) mann-whitney test result appeared that there was statistically nonsignificant difference between ball and bar design at time of insertion, while a significant difference affected after two years of using mir-od at the level (p<0.05) between ball and bar designs as shown in table (4). mann-whitney test was applied for comparison between two times of measurements (time of insertion and function time) for both mir-od designs. in table (5), it was appeared that there was a statistically significant difference in median value of two time of measurement. the differences between the result of bone loss at time of insertion and functions time appeared in table (6), in this table it was appeared that the higher value of bone loss in ball designed was 0.1mm.for bar design. j bagh college dentistry vol. 26(2), june 2014 radiographic follow up up restorative dentistry 9 table 1: descriptive of patients’ numbers and median of bone loss measurements in mm for ball and bar designs mir-od at time of insertion table 2: descriptive of patients’ numbers and median of bone loss measurements in mm for ball and bar designs mir-od after two year functions table 3: mann-whitney test for the comparison between ball & bar designs of mir-od at time of insertion *p>0.05 non significant table 4: mann-whitney test for the comparison between ball & bar designs of mir-od after two years functions *p<0.05 significant table 5: mann-whitney test for the comparison between two times of measurements (time of insertion and functions times) for ball & bar designs of mir-od *p>0.05 non significant table 6: bone loss (mm) differences between time of insertion and two years functions for both designs of mir-od arch sides design distal implant mesial implant distal side mesial side distal side mesial side n median n median n median n median right ball 3 0.49 3 0.1 3 0.07 3 0.08 bar 5 2.25 5 1.9 5 1.02 5 1.38 left ball 3 0.80 3 0.38 3 0.24 3 0.17 bar 5 1.85 5 2.00 5 1.75 5 2.32 arch sides designs distal implant mesial implant distal side mesial side distal side mesial side n median n median n median n median right ball 3 0.59 3 0.26 3 0.13 3 0.11 bar 5 2.40 5 2.20 5 2.5 5 2.40 left ball 3 0.90 3 0.48 3 0.23 3 0.18 bar 5 2.31 5 2.05 5 2.00 5 2.40 sites right left distal mesial distal mesial p-value sig p-value sig p-value sig p-value sig distal 0.662 ns 0.381 ns 0.664 ns 0.660 ns mesial 0.382 ns 0.384 ns 0.662 ns 0.661 ns sites right left distal mesial distal mesial p-value sig p-value sig p-value sig p-value sig distal 0.047 s 0.046 s 0.042 s 0.047 s mesial 0.036 s 0.034 s 0.035 s 0.039 s designs distal implant mesial implant distal side mesial side distal side mesial side p-value sig p-value sig p-value sig p-value sig ball 0.296 ns 0.601 ns 0.296 ns 0.110 ns bar 0.530 ns 0.100 ns 0.110 ns 0.111 ns designs right left distal mesial distal mesial distal side mesial side distal side mesial side distal side mesial side distal side mesial side ball 0.10 0.03 0.04 0.03 0.01 0.01 0.01 0.01 bar 0.10 0.08 0.10 0.10 0.10 0.10 0.10 0.05 j bagh college dentistry vol. 26(2), june 2014 radiographic follow up up restorative dentistry 10 discussion x-rays have been used to investigate or measure the amount of bone support around osseointegrated dental implant i.e. verifying osseointegration of oral implant after installation and the longitudinal control in their function and it can also be used for the identification of implant types is unknown in patient (10). the predictability and high success rate of implant treatment have averted attention for factors affecting fixtures loss and bone loss around implant. the successful maintenance of crestal bone surrounding dental implant is imperative for long-term implant success. the patients should be recalled every three months for evaluation of the prostheses and home care, with radiographs obtained every six months to detect any osseous changes. the survival rate for implant placed into loaded ridge and fresh extraction socket were 90.4 % (11). radiographic bone levels measured mesially and distally to short implant at 5 years were comparable to that around long implant (12). in the present study radiographs were taken to patients wearing mir-od for two years, since those most important changes, and the effects of dental plaque with other factors appeared after one year. (13,14) the median values of bone loss in two different intervals are displayed. the value displayed are the calibrated median value using the known implant length to measured implant length, bone measurement was done from the apex of dental implant to the radiography visualized bone. the result of the present study revealed that the difference in median value of both designs mir –od at time of insertion and functions time was 0.1 mm this was coincident the result obtained by good acre et al and wismeijer et al (15,16), this results of bone loss gives indication of successful dental implant treatments as alberketson et al and smith and zarb reported that the annual bone loss was less than 0.2 mm considered a successful criteria of dental implantology (17,18). since the results appeared that there was statistically non-significant difference between median values of bone loss at the time of insertion and after two year functions, so the results appeared to be coincide with fartash et al results of follow up examination from the first year, second year up to twelve years of follow up (19). the result of comparison between two designs of mir-od appeared that there was a significant difference between two designs of anchorage system. on the other hand, the results obtained by karadabuda appeared that there was no significant difference between the two anchorage system used for mir-od with respect to the soft tissue health status or patient satisfaction (20). references 1. engquist b, bergendal t, kallus t, linden u. a retrospective multicenter evaluation of osseointegrated implant supporting overdenture. int j oral maxillofac implant 1988; 3:129-34. 2. donatsky o. osseointegrated dental implants with ball attachments supporting overdentures in patients with mandibular alveolar ridge atrophy. int j oral maxillofac implant 1993; 8:162-66. 3. jeffcoat mk, reddy ms, van borg hr. quantitative digital subtractions radiography for the assessment of peri-implant bone change. clin oral impl res 1992; 3: 22-7. 4. stevens pi, fredrickson ej, gress ml, et al. implant prosthodontics clinical and laboratory procedures. 2nd. ed. mosby; 2000. 5. goodacre cj, bernal g, rungcharassaeny k, kan jk. clinical complications with implants and implants prostheses. j prosth dent 2003; 90: 121-32. 6. rasouli ghahroudi aar, talaeepour ar, rokn ar, akorsand a, mesgarzadel nn, kharazifard mj. radiographic vertical bone loss evaluation around dental implants following one year of functional loading. j dent tehran university medical sci 2010; 7: 289-97. 7. karousis lk, bragger u, salvi ge, burgin w, lang np. the effect of implant design on survival and success rates of titanium oral implants a10 year prospective studies of the iti dental implant system. clin oral implants res 2004; 15(1):847. 8. naert i, dky j, hanky f, quirynen m, vansteenbergher d. free standing and tooth implant connected prosthesis in the treatment of partially edentulous patient part ii. an up to 15 years radiographic evaluation. clin impl res 2001; 12: 245-51. 9. guilford jp. fundamental statistics in psychology and education. 5th ed. usa: 1973. 10. sewerin ip. comparison of radiographic image characteristics of branmark and imz implant. clin oral impl res 1991; 2: 151-5. 11. cavallaro js jr. implant survival and radiographic analysis of proximal bone levels surrounding a contemporary implant. impl dent 2011; 20(2):146152. (ivsl) 12. tqwil g, mawla m, gottlow j. clinical and radiographic evaluation of the 5mm diameter regular plateform branmark fixture: 2 to 5 years follow up. clin imp dent rel res 2002; 4(1):16-26. 13. becker w, becker ee, newman mg, nyman s. clinical and microbial finding that may contribute to dental implant failure. int j oral maxillofacial impl 1990; 5: 31-8. 14. meijer hgj, raghobar gm, van't hof ma,visser aa. controlled clinical trial of implant –retained mandibular overdenture:10 years clinical aspects and aftercare of imz implants and branmark implant. clin oral impl 2004; 15: 427-31. 15. venuleo c, chuang sk,weed m, dibart s. long term bone level stability on short implants a radiographic follow up study. j maxillofac & oral surg 2008; 7(3): 340-5. (ivsl). j bagh college dentistry vol. 26(2), june 2014 radiographic follow up up restorative dentistry 11 16. wismeijer d, vanwass maj, vermeeren kw. clinical and radiographical results of patients treated with three treatment modalities for overdentures or implant of the iti dental implant system. a randomized controlled clinical trial. j clin oral impl res 1999; 10: 297-306. 17. alberktsson t, zarb g, worthington r, eriksson ar. the long term efficacy of currently used dental implant; a review and proposed criteria of success, int j oral maxillofac implants 1986; 1: 11-25. 18. smith d, zard g. criteria for success of osseointegrated endosseauos implants. j prosthet dent 1989; 62: 567-72. 19. fartash b, tangrrud t, silness j, arvidson k. rehabilitation of mandibular edentulism by single crystal sapphire implants and overdentures: 3-12 year results in 86 patients a dual centre international study. clin oral impl res 1996; 7: 220-9. 20. karabuda c, tosun t, ermis e, ozdemir t. comparison of 2 retentive systems for implantsupported overdenures: soft tissue management and evaluation of patient satisfaction. j periodont 2002; 73: 1067-70. j bagh college dentistry vol. 32(4), december 2020 gingival health condition 25 gingival health condition among children of inbreeding parents compared to children of outbreeding parents in babylon governorate / iraq zahraa m wais(1), nadia aftan al rawi(2) https://doi.org/10.26477/jbcd.v32i4.2915 abstract background: consanguineous marriage is a relationship between biologically related individuals. genetic factors have a role in gene environment interactions that takes the center stage. the evidence of oral disease (gingivitis and periodontitis) may depend on genetic syndromes, inherited diseases, familial studies etc. the present study aims at assessing dental plaque and gingival health condition in children of inbreeding parents compared with children of outbreeding parents among primary schools in al-qasem city/ babylon governorate in iraq. materials and methods: this comparative study included three hundred ninety eight (398) students, 6-12 years old, from 4 primary schools; 199 children had their parents of inbreeding marriage with first level of inbreeding, and the other 199 children had parents of outbreeding marriage. plaque status was assessed according to index of silness and loe (1964), gingival health status according to index of loe and silness (1963). results: children of inbreeding parents showed significantly higher plaque index and gingival index mean values than children of outbreeding parents. mild gingivitis was found as the most prevalent type among both groups. a highly significant positive correlation was found between gingival and plaque indices. conclusion: inbreeding rates have an effect on oral health, as the children of outbreeding parents had significantly better oral hygiene and gingival health condition than children of inbreeding parents. key words: consanguineous marriage, inbreeding, oral health. (received: 10/8/2019; accepted: 1/9/2019) introduction inbreeding is defined as a union between two individuals who related as second cousins or other relation. inbreeding rates differ in communities depending on religion, culture, and geography. (1) as a consequence of inheriting the identical chromosomal segment through both parents, who inherited it from ancestor, the individuals born of consanguineous marriage have a number of pieces of their chromosomes which are homozygous. for this reason, inbreeding increases the homozygosity and, then, recessive alleles masked by heterozygosity with predominant alleles will be assert through inbreeding. therefore, it is conventional that recessive traits such as most human genetic disorders which occur when frequency increase in the progeny of inbreeding couples. as in more, many recessive alleles found in natural populations that have adverse effects on organism, usually inbreeding make decrease in size, reproductive fitness and vigor. however, it is (1) m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad .. (2) assistant professor, department of pedodontics and preventive dentistry , college of dentistry, university of baghdad . corresponding author, missdentist1990@yahoo.com necessary to consider that consanguineous marriage can happen through two different biological positions. (2) the degree of relationship between the individuals in a population depends on the size of that population which is more closely related one to other in limited population than in broad one. so, inbreeding is a phenomenon usually combines with small populations. in different circumstances, inbreeding can happen in a large population as a form of nonrandom marriage when the frequency of consanguineous marriage is more than that anticipated by chance. (1,2) consanguineous marriage is common in many countries, first-cousin marriage and other types of consanguineous marriage are common in a number of general populations from different places of the world. (3,4) research on the relationship between consanguinity and many parameters of oral and periodontal health status is limited, both in quality and quantity. (5,6) periodontal disease is genetically inherited and appears to follow an autosomal recessive pattern, even though parents were phenotypically healthy but carried the recessive gene for the syndrome so can appear in their children. an increased prevalence of parental consanguinity around 2040% has been reported in papillon-lefevre syndrome patients. (7) dental plaque can be defined as “the soft non mineralized bacterial deposit which form and adhere firmly to the tooth, clinically can https://doi.org/10.26477/jbcd.v32i4.2915 j bagh college dentistry vol. 32(4), december 2020 gingival health condition 26 be realized when it reaches certain thickness as a whitish or a yellowish layer along gingival margin”. (8) plaque accumulation is greatest in the sheltered interdental region hence gingival inflammation tend to start in the interdental papilla and spreads from there around the neck of the tooth lead to gingivitis. (9) in a study by çalışır(10) about relation of inbreeding and oral health between consanguineous and the non-consanguineous groups, the gingival index was higher in the siblings of the consanguineous marriage than non-consanguineous group. in addition, he found displayed the siblings of the consanguineous marriage about eight times more prevalence of aggressive periodontitis than the siblings of the non-consanguineous marriage. moreover, the mode of transmission of disease was recorded to fit greater to the autosomal recessive inheritance design. kindler syndrome, represented as uncommon subtype of inherited epidermolysis bullosa, is characterized by oral symptoms like periodontitis, gingivitis, and loss of teeth. however, a common feature in populations with high rates of inbreeding marriage was kindler syndrome. (11) chronic granulomatous disease (cgd) is inherited disease of the innate immune system that is characterized by impaired phagocyte microbicidal activity. it is caused by genetic defects, inherited as an autosomal recessive pattern, and characterized by severe neutropenia. patients suffer from recurrent gingivitis and even severe periodontitis. to have a family history of consanguineous parenthood may be a predisposing factor for genetic agranulocytosis. (12) in 1995, dental examination of 120 pupils aged (619) years old with high prevalence of inbreeding 69% were studied and compared to tunisian pediatric dentistry society (tpds) that outbreeding marriage. the results showed similar caries experience, and that carious process is infectious and not inherited. (13) this study was conducted in order to assess the impact of inbreeding on oral hygiene and gingival health condition in comparison to children of outbreeding parents. materials and methods three hundred ninety eight (398) students, 6-12 years old, were collected from 4 primary schools, they were divided into 199 children that their parents of first level of inbreeding marriage (study group), and other 199 children their parents outbreeding marriage (control group), in al-qasem city/ babylon governorate, in iraq. this comparative study sample was calculated by the formula: n=zp2(1-p)/d2. (14) this study was done during the period from december 2018 to february 2019. a pre-study ethical approval was assigned, also the children's parent consent form was taken before starting the study. family history of type of marriage was taken. information on the type of marriage of the parents was obtained; whether the inbreeding marriage or outbreeding marriages by answering the papers presented to them as seen in descriptive statistics of consanguineous marriage for both the pakistan and the bangladesh. (15) inclusion criteria; students with: •no history of medication, (antimicrobial treatment or antiinflammatory) within last three months . •no history of orthodontic treatment. diagnostic criteria included the gender, age and history of family if inbreeding parents or not . oral examination was performed on chairs, under good illumination by using dental mirror, probe and dental tweezers following the main approach of the oral health survey recommended by (who, 1997). oral cleanliness was assessed according to the criteria of plaque index by silness and loe (1964) (16) by examining the thickness of plaque at the cervical margin of the tooth. four areas were examined, distal, facial or buccal, mesial, and lingual. the 6 index teeth were examined to represent entire dentition. gingival condition was assessed using loe and silness (1963) (17), the gi assesses the severity of gingivitis based on consistency, color and bleeding on probing. it describes the severity of gingival inflammation and its location. mesial, lingual, distal, and facial (or buccal) surface of teeth were examined . data description, analysis and presentation were performed using the statistical package for social sciences (spss, version 21). statistical analysis included: 1-descriptive analysis: mean and se. 2-inferential analysis: t test, spearman correlation (r), (p-value<0.05 considered significant). results table 1 demonstrates the distribution of total sample by age. a high percentage of students was found at age group 6-10 years old among both groups. the distribution of total sample according to gender is seen in table 2. this table shows a j bagh college dentistry vol. 32(4), december 2020 gingival health condition 27 higher percentage of females was recorded among both groups . table (1): distribution of the total sample by age among inbreeding and outbreeding. groups age (years) 6-10 +10-12 inbreeding n 130 69 % 65.3 34.6 outbreeding n 140 59 % 70.3 29.6 table (2): distribution of total sample by gender among inbreeding and outbreeding. groups gender male female inbreeding n 98 101 % 49.25 50.75 outbreeding n 96 103 % 48.24 51.76 table 3 demonstrates the mean value and se of plaque index according to age, gender and breeding rate among children. regarding age group, the result showed a higher mean value of plaque index at age 6–10 years old than children at age 10.1–12 years among in breeding group, while for outbreeding group, the result was opposite showed the children at age 10.1–12 years had higher plaque index mean than children at age 6–10 years. for the total sample this table shows that the mean value of dental plaque index was 2.05±0.05 in inbreeding group and 1.16±0.06 among outbreeding group, statically highly significant differences were existed between two groups with p=0.00 . table (3): mean and standard error of plaque among inbreeding and outbreeding by age and gender . age (y) groups t inbreeding outbreeding n mea n n mean <= 10 63 2.06 61 1.02 7.07 67 2.16 79 1.20 7.23 130 2.12 140 1.12 10.0 10 + 35 1.86 35 1.31 2.76 34 1.97 24 1.19 3.45 69 1.91 59 1.26 4.42 total 199 2.05 199 1.16 10.6 p value 0.00 *significant p< 0.05 mean value of gingival index tended to be higher in inbreeding group than in outbreeding group, differences were statistically highly significant existed between both groups (p =0.00). in addition, gingival index tended to be higher in age group (6– 10) compared with age group (10.1–12) among both inbreeding and outbreeding groups (table 4). table (4): mean and standard error of gingival index among inbreeding and outbreeding by age and gender. age (y) g groups t p value inbreeding outbreeding n mean n mean <=10 m 63 2.06 61 1.02 7.07* .00 f 67 2.16 79 1.20 7.23* .00 t 130 2.12 140 1.12 10.0* .00 10+ m 35 1.86 35 1.31 2.76* .00 f 34 1.97 24 1.19 3.45* .00 t 69 1.91 59 1.26 4.42* .00 total 199 2.05 199 1.16 10.6* .00 *significant p< 0.05 a highly significant strong positive correlation coefficient was recorded between plaque and gingival index among inbreeding group, while highly significant weak positive was found in outbreeding group (table 5). results showed mild gingivitis was the most common type of gingival severity among children, followed by a moderate and severe type (table 6) . table (5): correlation coefficient between plaque index and gingival index among inbreeding and outbreeding . groups gingival index inbreeding plaque index r .542* p .000 outbreeding plaque index r .451* p .000 j bagh college dentistry vol. 32(4), december 2020 gingival health condition 28 table (6): distribution of children according to gingival health condition among inbreeding and outbreeding . discussion to our knowledge, there was no previous iraqi study to compare the findings of this study with. therefore, the data of current study can be compared with other studies in other countries in the world regarding impact of inbreeding on oral health of their children. dental plaque thickness and gingival health status were assessed in the present study among children of inbreeding parents and children of outbreeding parents using plaque index of silness and loe(16) and gingival index of loe and silness.(17) these indices are widely used in the controlled and epidemiological studies because of their flexibility which provides the possibility of measuring the severity of the disease and to get more precise result to overcome any inaccuracy due to missing teeth. another advantage is the ease of application. (18) in this study, the plaque index showed highly significant differences between children of inbreeding marriage and children of outbreeding marriage. this may be related to genetic factors, (19) lifestyle and work, and environment. (20) in addition, the evidence of periodontitis is dependent on the genetic syndromes, inherited diseases, familial studies etc.(21) susceptibility of periodontal diseases is inherited as an x-linked dominant trait. evidence of plaque index has been confirmed by studies of fraternal twins and identical twins which reared together and identical twins reared apart. (22) results of current study revealed that gingival index showed highly significant differences between children of inbreeding marriage and children of outbreeding marriage, which could be due to that periodontal disease is genetically inherited and appears to follow an autosomal recessive pattern, even though parents were phenotypically healthy but carried the recessive gene for the syndrome, so can appear in their children. (7) as mean of plaque index, mean of gingival index increase, this due to positive highly significant correlation between plaque and gingival indices in this study, and this in agreement with study done by layth and al-rawi who reported positive highly significant relation between gingival index and plaque index.(23) this may be attributed to that when dental plaque increases, bacteria increase in number and increase in bacterial toxins which lead to increase in gingival disease (24) conclusion the gingival disease was significantly higher in inbreeding group than in outbreeding group, with a worst oral hygiene . references 1. bittles ah. consanguinity and its relevance to clinical genetics. clinical genetics. 2001 aug;60(2):89-98 . 2. alvarez g, quinteiro c, ceballos fc. inbreeding and genetic disorder. in advances in the study of genetic disorders 2011 nov 21. 3. lauc t, rudan p, rudan i, campbell h. effect of inbreeding and endogamy on occlusal traits in human isolates. journal of orthodontics. 2003 dec 1;30(4):301-8 4. bener a, hussain r. consanguineous unions and child health in the state of qatar. paediatric and perinatal epidemiology. 2006;20: 372‐378 5. bittles ah, black ml. consanguinity, human evolution, and complex diseases. proceedings of the national academy of sciences. 2010 jan 26; 107 (suppl 1):1779-86 . 6. tadmouri go, nair p, obeid t, al ali mt, al khaja n, hamamy ha. consanguinity and reproductive health among arabs. reproductive health. 2009; 6 (1):17 . 7. ragupathy, k., prlyadharsini, i. and pasupathy, s. parental consanguinity as risk factor in papillonlefevre syndrome: ac ase report. int j dent med res. 2015 1(6), p.68 . 8. dumitrescu al, kawamura m. etiology of periodontal disease: dental plaque and calculus. in etiology and pathogenesis of periodontal disease 2010 jan 1 (pp. 138). springer berlin heidelberg . 9. marya cm. a textbook of public health dentistry. jp medical ltd; 2011 mar 14 . 10. çalışır m. consanguinity increases the risk for aggressive periodontitis. j period res. 2018 oct; 53 (5):902-9 . 11. youssefian l, vahidnezhad h, saeidian ah, ahmadizadeh k, has c, uitto j. kindler syndrome, an age (y) groups gi severity 0.1-1 mild 1.1-2 moderate 2.1severe % % no. % 6–10 inbree ding 42.3 39.23 15 11.5 outbree ding 25.0 17.14 0 .00 total 33.3 27.78 15 5.56 10+ inbree ding 34.7 33.33 10 14.4 outbree ding 38.9 8.47 0 .00 total 36.7 21.88 10 7.81 total inbree ding 39.7 37.19 25 12.5 outbree ding 29.1 14.57 0 .00 total 34.4 25.8 25 6.2 j bagh college dentistry vol. 32(4), december 2020 gingival health condition 29 orphan disease of cell/matrix adhesion in the skin– molecular genetics and therapeutic opportunities. expert opinion on orphan drugs. 2016 aug 2;4(8):845-54 . 12. zeidler c, germeshausen m, klein c, welte k. clinical implications of ela2‐, hax1‐, and g‐csf‐receptor (csf3r) mutations in severe congenital neutropenia. bj of haematology. 2009 feb;144(4):459-67 . 13. maatouk f, laamiri d, argoubi k, ghedira h. dental manifestations of inbreeding. j clin pediatr dent. 1995;19(4),pp.305-6 . 14. daniel ww. biostatistics: a foundation for analysis in the health science. 7th edn. new york: john wiley and sons. 1999 . 15. mobarak am, chaudhry t, brown j, zelenska t, khan mn, chaudry s, wajid ra, bittles ah, li s. estimating the health and socioeconomic effects of cousin marriage in south asia. j of biosocial science. 2019 may;51(3):418-35 16. silness j, löe h. periodontal disease in pregnancy ii. correlation between oral hygiene and periodontal condition. actaodontologicascandinavica. 1964 jan 1;22 (1):121-35 . 17. löe h, silness j. periodontal disease in pregnancy i. prevalence and severity. actaodontologica scandinavica. 1963 jan 1; 21 (6):533-51 . 18. senevirate cj, zhang cf, samaranayake lp. dental plaque biofilm in oral health and disease. chin. j of dent. research. 2011 jan 1; 14 (2):87 19. murray j, nunn j, steel j. (2003): the prevention of oral disease. 4th ed.96-121. oxford, new york . 20. petersen pe, bourgeois d, ogawa h, estupinan-day s, ndiaye c. the global burden of oral diseases and risks to oral health. bulletin of the world health organization. 2005; 83: 661-9 . 21. taba jr m, souza sl, mariguela vc. periodontal disease: a genetic perspective. brazilian oral research. 2012; 26 (spe1):32-8 . 22. tarannum f, faizuddin m. effect of gene polymorphisms on periodontal diseases. indian j. hum. genet. 2012 jan; 18 (1):9 . 23. layth nm. al-rawi na. oral health status in relation to nutritional status among a group of 13-15 years old intermediate school girls in al-najaf city/iraq master thesis, college of dentistry, university of baghda, ) 2017. 24. lang np, lindhe j, editors. clinical periodontology and implant dentistry, 2 volume set. john wiley & sons; 2015 mar 25 . الخالصة الصدارة. الخلفية: زواج األقارب هو عالقة بين األفراد ذوي الصلة بيولوجيا. العوامل الوراثية لها دور في التفاعالت البيئة الجينية تأخذ مركز العائلية يعتمد الدليل على أمراض الفم )التهاب اللثة والتهاب اللثة والعظم( على دراسة األمراض الوراثية والمتالزمات الوراثية والدراسات وما إلى ذلك متزوجينطفال من أولياءاهداف الدراسة: أجريت هذه الدراسة لتقييم حدوث وانتشار نظافة الفم )الحالة الصحية للثة اللويحة السنية( عند األ / محافظه بابل ، في العراق أقارب ، مقارنة بأطفال من اآلباء المتزوجين خارج اقارب في المدارس االبتدائية في مدينة القاسم طفاًل 199مدارس ابتدائية ، شارك 4عاًما ، من 126( طالبًا ، تتراوح أعمارهم بين 398المواد وطرق العمل: ثالثمائة وثمان وتسعون ) طفاًل آخر من آبائهم لم يتزوجوا زواًج اقارب (المجموعة الضابطة( 199والداهم في زواج األقارب ، و loe and silness(1963 ). تم تقييم صحه اللثة وفقا لقياس silness and loe( 1964حالة الصفيحه الجرثومية وفقًا ل قياس) تم تقييم النتائج: قيمة متوسطة عالية لمؤشر الصفيحة الجرثومية ومؤشر اللثة لدى أطفال الوالدين زواج األقارب مقارنه ب األطفال من اآلباء غير تالف كبير إحصائيا. تم العثور على التهاب اللثة الخفيف أكثر األنواع انتشاًرا بين المجموعتين ، يليه نوع معتدل وشديد. زواج األقارب مع اخ يوجد ارتباط إيجابي كبير للغاية بين مؤشرات اللثة والبالك والدين زواج األقارب مقارنه ب األطفال من االستنتاج: تم تسجيل ارتفاع في معدل انتشار الصفيحة الجرثومية ومؤشر اللثة ، عند أطفال ال .اآلباء زواج خارج األقارب j bagh college dentistry vol. 33(4), december 2021 evaluation of cytotoxicity 02 evaluation of cytotoxicity and biocompatibility of ti2alc in rabbits luma m. ibrahim (1), raghdaa k. jassim (2) ahmed al gabban(3) https://doi.org/10.26477/jbcd.v33i4.3015 abstract background: the titanium and its alloys are suitable for dental implant and medical applications. biocompatibility of the materials is a major factor in determining the success of the implant and has a great impact on their rate of osseointegration. the aim of this study was to evaluate the biocompatibility and cytotoxicity of ti2alc in comparison to cpti & ti6al7nb in rabbits. materials and methods: 10 male new zealand white rabbits, weighing (2-2.5 kg), aged (10-12 months) were used in this study. cylindrical implants were prepared from the study materials (cpti, ti6al7nb and ti2alc) with (8mm) height and (3mm) diameter for the evaluation of tissue response and disc specimens were prepared with (6 mm) diameter and (2 mm) thickness for evaluation of cytotoxicity mtt test. a histological study was performed at 2 & 6 weeks postsurgical implant insertion. results: histological findings show that ti2alc has enhanced proliferation of osteo-progenitor cell and reported mature bone formation at 6 weeks. moreover, ti2alc has recorded a higher percentage for viable cells by mtt test in comparison to cpti and ti6al7nb. conclusion: the new ti2alc dental implant is considered biocompatible and has showed a better bone formation than the cpti and ti6al7nb materials at 2 & 6 weeks. keywords: bone healing, cpti, ti6al7nb, ti2alc, osseointegration, dental implant, . (received: 22/9/2021, accepted: 13/10/2021) introduction titanium regards as a key factor for the establishment of implant tissue interaction and for the assessment of biocompatibility of its alloy [1]. titanium is applicate in many studies in prosthodontics, conservative and in orthodontics due to their resistance to corrosion and their good tolerance by tissue without causing harms or damage. [2,3,4] titanium and its alloys may release ions in saliva that contact the oral mucosa and may cause tissue reaction including toxicity or allergy reaction [5,6]. most researches record that titanium is the least metal material that induces allergy; therefore, it is regarded as material of choice for biological application. moreover, ti6al7nb alloy is light in weight, have very high tensile strength and well tolerated by bone tissue and reported to be used for biomedical purposes [7,8,9] (1) phd student, college of dentistry, al farahidi university, baghdad, iraq. (2) professor, department of prosthodontics, college of dentistry, university of baghdad, baghdad, iraq (3) professor ahmed al gabban, department of material engineering, university of technology, baghdad, iraq corresponding email, dr_lumakurbasi@yahoo.com the evaluation of cytotoxicity of implant materials along with its osseointegration and bone formation potential becomes important concerning the clinical application of these materials in service and their success in implantation. the relationship between viability of bone cell that contact implant surface and tissue reaction have been recorded in several studies [10,11,12]. the objective of this study was to evaluate the cytotoxicity and bone tissue response in rabbit for the new prepared ti2alc implant in comparison to commercially pure titanium cpti and ti6al7nb alloy by using histological examination and methyl thiazolyltetrazolium mtt assay at different periods. materials and methods animals a total of 10 male new zealand white rabbits, weighing (2-2.5 kg) and aged (10-12 months) were used in this study, and kept in the animal department of (national center of drug control and research /iraq) at a constant humidity and temperature of 23°c according to the national https://doi.org/10.26477/jbcd.v33i4.3015 j bagh college dentistry vol. 33(4), december 2021 evaluation of cytotoxicity 02 council’s guide for the care of laboratory animals. the following materials were used in this study: -cpti rods and ti6al7nb rods, 6 mm in diameter from straumann company, switzerland. -ti2alc powder astm e8m03 (famouschem technology shanghai) was used to prepare implant, by using (0.5g) of powder of ti2alc that was condensed by dental condenser of (0.5mm) size. the punch was allowed to seat over the solid steal rod and when the mold was filled with a condensed powder, compaction was started by using a punch guide. pressing with hydraulic press started using (100 mpa) for (10min). the specimen was ejected by using the long punch after that the base removed and left for drying 24 hours at room temperature. cylindrical implants were prepared from the study materials with (8mm) height and (3mm) diameter for evaluation of tissue response and disc specimens were prepared with (6 mm) diameter and (2 mm) thickness for evaluation of cytotoxicity assessment by mtt test. [13] in vivo study three implants were implanted in the proximal third of the lateral aspect of the femoral bone, the ti2alc and ti6al7nb implant were applicate in the right femur while cpti was implanted in the left femur. according to the healing interval, the experimental rabbits were divided into two groups (2, 6 weeks), each group consists of 5 animals sacrificed for histological study. in vitro study (cytotoxicity test) cultured for fibroblast cell line (murine nih 3t3 cell line 93061524 – sigma) in dulbecco's modified eagle medium. seed the cells in a 96-well microplate at a density of (1 x 104 with 100 µl) per well. cultures were incubated at 37°c in a humidified atmosphere of 5% co2 in air. in the present study, 6 cut samples from each rod of cpti, ti6al7nb and ti2alc were used for cytotoxicity evaluation with fibroblast cells. cells were treated with different doses of examined materials. then, these cells were estimated for their proliferation and viability by methyl thiazolyltetrazolium mtt colorimetric assay, using spectrophotometer record the absorbance at 570 nm as described by wang et al. [14]. percentage viability was calculated as follows: statistical analysis all records were entered into excel spread sheets for evaluation with the statistical package deal for social studies (spss) (chicago, il, united states of america). the data were analyzed using oneway anova test. results 1.histological findings: microscopic features for all specimens of implant for cpti group at 2 weeks post-operative duration, show a sparse of bone trabeculae surrounding by osteoblast with basal bone around implant bed. at 6 weeks postoperative duration, the specimens show basal bone coalesce with newly formed thin bone trabeculae at the bed implant region, with presence of fibrous tissue surrounding implant figure 1 (a&b). microscopic evaluation for all specimens of implant for ti6al7nb group at 2 weeks postoperative duration shows bone marrow with a sparse of bone trabeculae coalesce with basal bone, while at 6 weeks post-operative duration, the specimens show a thin rim of fibrous tissue surrounding the implant with bone trabeculae full most of implant bed, figure 1 (c&d). implant for ti2alc group at 2 weeks postoperative duration shows basal bone with attached newly formed bone trabeculae surrounded by active proliferating osteogenic cells. at 6 weeks all specimens show mature bone surrounding the implant, figure1 (e&f). 2.mtt results the results of cytotoxicity of cpti, ti6al7nb and ti2alc by detection and estimation of viable cells for the whole concentration that used for mtt test after 72 h are illustrated in figure (2) and table (1). the material (ti2alc) showed a higher percentage of cell viability (89.6461 ±7.6468) followed by ti6al7nb (80.6306 ±5.6362). a significant p value (.001) is recorded for cell viability within and between the examined materials by using anova test, table (2). j bagh college dentistry vol. 33(4), december 2021 evaluation of cytotoxicity 00 figure (1) microscopic view for different examined materials at (2 & 6 weeks) where basal bone (bb), few scattered bone trabeculae (bt), osteoid tissue (ost), osteoblast (arrows). a. cpti implant at 2-week duration b. cpti implant at 6-week duration c. ti6al7nb implant at 2-week duration d. ti6al7nb implant at 6week duration e. ti2alc implant at 2-week duration f. ti2alc implant at 6week duration figure (2) cell viability of cpt(ti), ti6al7nb (ti6) and ti2alc(max) after 72 h. table (1) descriptive statistic for mtt assay table (2) anova test for the all studied groups for mtt assay material n mean std. 95% confidence interval for mean lower bound upper bound cpti 6 64.19 12.95 50.596 77.796 nb7al6ti 6 80.63 5.63 74.715 86.545 alc2ti 6 89.64 7.46 81.621 97.670 test of homoginity levene statistic df1 df2 sig. 3.364 2 15 .062 sum of squares df mean square f sig. between groups 1998.141 2 999.070 11.609 .001 within groups 1290.920 15 86.061 total 3289.060 17 h&e x20 h&e x10 h&e x20 h&e x10 h&e x10 h&e x10 j bagh college dentistry vol. 33(4), december 2021 evaluation of cytotoxicity 02 discussion titanium and their alloys implant have been widely used in various branches of dentistry. as implant materials have direct contact with the bone tissue and may interact with cells of the body, therefore, their success not only require an acceptable physical and chemical properties but also must have good biocompatibility [15,16] .in vivo study hasbeen done by implantation of different materials (cpti, ti6al7nb and ti2alc) to investigate their ability in enhancement of osseo-integration and bone formation .our results for ti2alc implant report an obvious proliferation of osteoprogenitor cells at 2 weeks and a well mature bone formation at 6 weeks in comparison to cpti, ti6al7nb which recorded a rim of fibrous tissue around the implant with bone trabeculae filled more than half of implant bed, although ti6al7nb alloy showed more bone formation than cpti, immature bone was detected in most of their examined specimens . many studies revealed that titanium and ti6al7nb alloy were used in dental implant due to their excellent compatibility with surrounding tissues [17,18]. on the other hand, the present results focus on excellent findings related to tissue response by newly ti2alc implant material. in vitro studies have been performed by using of cytotoxicity test to evaluate the biological effects of the examined materials on growth and viability of fibroblast cell which is derived from the mesenchymal layer as having the same origin of the osteoblast cells. the cell viability was recorded by mtt test thatwas based on mitochondrial enzyme which reduced the yellow mtt dye into insoluble formazan, and the number of viable cells were calculated [19,20,21]. the results indicated that ti2alc material showed a higher percentage of viable cells in whole recorded concentration that coincided and supported the histological findings in better bone formation and maturation in comparison to cpti and ti6al7nb materials. conclusion the present study concludes that the new ti2alc implant material is considered a biocompatible and less toxic to cells by recording high percentage of cell viability and showing a better bone formation than the cpti and ti6al7nb materials at 2and 6week period. financial support and sponsorship: nil. conflict of interest: there are no conflicts of interests. references 1. wang rr, fenton a. titanium for prosthodontic applications: a review of the literature. quintessence int. 1996 jun; 27(6):401-408. 2. abdel-hady gepreel m, niinomi m. biocompatibility of ti-alloys for long-term implantation. j mech behav biomed mater. 2013 apr; 20:407-415. 3. hwang yj, choi ys, hwang yh, et al. biocompatibility and biological corrosion resistance of ti-39nb-6zr+0.45al implant alloy. j funct. biomater. 2020 dec 29;12(1):2. 4. okazaki y, rao s, ito y, et al. corrosion resistance, mechanical properties, corrosion fatigue strength and cytocompatibility of new ti alloys without al and v. biomaterials. 1998 jul; 19(13):1197-1215. 5. chandar s, kotian r, madhyastha p, et al. in vitro evaluation of cytotoxicity and corrosion behavior of commercially pure titanium and ti-6al-4v alloy for dental implants. j indian prosthodont soc. 2017 janmar;17(1):35-40. 6. jorge jr, barão va, delben ja, et al.titanium in dentistry: historical development, state of the art and future perspectives. j indian prosthodont soc. 2013 jun; 13(2):71-79. 7. kajzer a, grzeszczuk o, kajzer w, et al. properties of ti-6al-7nb titanium alloy nitrocarburized under glow discharge conditions. acta bioeng biomech. 2017;19(4):181-188. 8. de oliveira dp, toniato tv, ricci r, et al. biological response of chemically treated surface of the ultrafine-grained ti-6al-7nb alloy for biomedical applications. int j nanomedicine. 2019 mar 6;14: 1725-1736. 9. okulov iv, joo sh, okulov av, et al. surface functionalization of biomedical ti-6al-7nb alloy by liquid metal dealloying. nanomaterials (basel). 2020 jul 28;10(8):1479. 10. savadi rc, goyal c. study of biomechanics of porous coated root form implant using overdenture attachment: a 3d fea. j indian prosthodont soc. 2010;10: 168–175. 11. mcmahon re, ma j, verkhoturov sv, et al. a comparative study of the cytotoxicity and corrosion resistance of nickel-titanium and titanium-niobium shape memory alloys. acta biomater. 2012;8: 2863–2870. 12. soenen sj, manshian b, montenegro jm, et al. cytotoxic effects of gold nanoparticles: a multiparametric study. acs nano. 2012;6: 5767– 5783. 13. luma m., raghdaa k., ahmed al gabban. manufacturing and characterizing of tialc (max phase alloy) in comparison with cpti and ti6al7nb as a dental implant material. j res med dent science. 2021 jul; 9 (8) :2347-2367 14. wang qy, wang yb, lin jp, et al. development and properties of ti-in binary alloys as dental https://www.ncbi.nlm.nih.gov/pubmed/24431713/ https://www.ncbi.nlm.nih.gov/pubmed/24431713/ https://www.ncbi.nlm.nih.gov/pubmed/24431713/ j bagh college dentistry vol. 33(4), december 2021 evaluation of cytotoxicity 02 biomaterials. mater sci eng c mater biol appl. 2013; 33: 1601–1606. 15. siddiqi a, payne agt, de silva rk et al. titanium allergy: could it affect dental implant integration? clin oral implants res. 2011 jul;22(7):673-680. 16. lapin j, kamyshnykova k, klimova a. comparative study of microstructure and mechanical properties of two tial-based alloys reinforced with carbide particles molecules. 2020 jul 28;25(15):3423. 17. comino-garayoa r, cortés-bretón brinkmann j, peláez j, et al. allergies to titanium dental implants: what do we really know about them? a scoping review. biology (basel). 2020 nov 18;9(11):404. 18. hoornaert a, vidal l, besnier r, et al. biocompatibility and osseointegration of nanostructured titanium dental implants in minipigs. clin oral implants res. 2020 jun;31(6):526-535. 19. brunet g, cabioch th, chartier p et al. reaction synthesis of layered ternary ti2alc ceramic, j european ceramic society 2009; 29(1):187-194. 20. jin j, zhang l, shi m, et al. ti-go-ag nanocomposite: the effect of content level on the antimicrobial activity and cytotoxicity. int j nanomedicine. 2017 jun 7; 12:4209-4224. 21. zhenhuan w, yu d, junsi l et al. physio-chemical and biological evaluation of slm-manufactured ti10ta-2nb-2zr alloy for biomedical implant applications. biomed mater. 2020 jun 23;15 (4) 5004-5017. الخالصة ئيسياً في تحديد ر: يَُعدُّ التيتانيوم وسبائكه مناسباً لزراعة األسنان والتطبيقات الطبية، إذ يمثّل التوافق الحيوي )البيولوجي( للمواد عامالً الخلفية ةنجاح عملية الزرع وله تأثير كبير على معدل اندماجها العظمي. كان الهدف من هذه الدراسة هو تقييم التوافق الحيوي )البيولوجي( والسمي ( في األرانب.nb7al6ti)( وسبائك التيتانيوم الطبية cpti( مقارنة بـالتيتانيوم النقي تجارياً )alc2tiالخلوية لكربيد األلومنيوم التيتانيوم ) كغم( لكل منها، وتتراوح أعمارها 2.2-2من ذكور األرانب النيوزيلندية البيضاء في هذه الدراسة، بوزن ) 01مواد البحث وطرقه: تم استخدام ملم( 3قطر )ملم( وب 8( بارتفاع )alc2tiو cpti ،nb7al6tiشهراً(. وتم تحضير زرعات أسطوانية من مواد الدراسة ) 02-01بين ) . وأجريت الدراسة mttملم( لتقييم السمية الخلوية عن طريق اختبار 2ملم( وسمك ) 6لتقييم استجابة األنسجة، وإعداد عينات قرصية بقطر ) أسابيع من وضع الزرعة بعد الجراحة. 6النسيجية بعد أسبوعين و 6لخاليا السلفية )األولية( العظمية، والحظ تكوين عظام ناضجة في غضون عّزز من تكاثر ا alc2tiالنتائج: تظهر النتائج النسيجية أن الـ .nb7al6tiوالـ cptiمقارنةً بـالـ mttنسبة مئوية أعلى للخاليا الحيوية عن طريق اختبار alc2tiأسابيع. عالوة على ذلك، سجل الـ ة متوافقة حيوياً، وأظهرت تكوين أفضل للعظام مقارنة بمواد الـ الجديد alc2tiاالستنتاجات: تعتبر زرعات األسنان المحضرة من مادة الـ cpti والـnb7al6ti أسابيع. 6خالل أسبوعين و ، االندماج العظمي، زراعة األسنانicpt ،nb7al6ti ،alc2ti الكلمات الرئيسة: شفاء العظام ، articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. mohammed final.doc j bagh college dentistry vol. 26(3), september 2014 the effect of various orthodontics, pedodontics and preventive dentistry 144 the effects of various beverages on the shear bond strength of light-cured orthodontic composite (an in vitro comparative study) mohammed nahidh, b.d.s., m.sc. (1) abstarct background: this study was conducted to assess the effects of various beverages on the shear bond strength of lightcured orthodontic composite used to bond stainless steel orthodontic brackets on human teeth and to determine the site of bonding failure of this material. materials and methods: fifty extracted human premolars were selected and randomly divided into five equal groups each with 10 teeth according to the beverage type (control, one tiger, milk, green tea and coffee). after bonding, the teeth were immersed in specific beverages for 5 minutes twice daily with equal intervening intervals then washed and stored in distilled water at 37º c for the reminder of the day. the process was carried out for 30 days. the samples were then tested for shear bond strength using tinius-olsen testing machine with a crosshead speed of 0.5mm/minute. for adhesive remnant index, the enamel surface and bracket base of each tooth were inspected under magnifying lens (20x) of a stereomicroscope. results: milk, coffee and one tiger energy drink reduced the shear bond strength of the light-cured composite significantly unlike the green tea. the predominant site of bond failure was between the bracket base and the adhesive leaving the composite on the tooth rather on the brackets base. conclusions: orthodontic patients should be instructed to reduce the intake of acidic and fatty beverages to prevent debonding of the orthodontic brackets. keywords: shear bond strength, beverages, orthodontic adhesive. (j bagh coll dentistry 2014; 26(3):144-148). الخالصة .مع االسنانط ابترال، وتحدید موقع فشل ا یةالفوالذ نانلحاصرات تقویم االس ةصاقوة القالر المشروبات المختلفة على یثتأأجریت ھذه الدراسة لتقییم : خلفیة ال مشروب الطاقة ، ماء مقطر(اسنان وفقا لنوع الشراب 10قسمت عشوائیا إلى خمس مجموعات متساویة كل منھا التيضواحك البشریة ومن التم اختیار خمسون :المواد و األسالیب وقد º 37 في درجة حرارةغسلھا وتخزینھا في الماء المقطر تم دقائق مرتین یومیا ثم 5مشروبات لمدة الفي سنانغمر االتم .) قھوة، الحلیب ، الشاي األخضر وال االول النمر .خاصة و بمعاییر معینة باستخدام آلة اختبار لحاصرات تقویم االسنان ةصاقوة القالتم اختبار . یوما 30أجریت عملیة لمدة على عكس مما ھي علیھ في المجموعة الضابطة بشكل ملحوظاالول اقل النمرمشروب الطاقة الحلیب ، القھوة و یة فيالفوالذ اصرات تقویم االسنانلح ةصاقوة القكانت ال :النتائج .الشاي األخضر .نمرضى تقویم األسنالمن تناول المشروبات الحمضیة والدھنیة االقالل یجب: االستنتاجات .تقویم األسنان حاصرات، المشروبات، ةصاقوة القال: مفتاحیةكلمات الال introduction soft drink consumption has gradually increased in recent decades in both western and developing countries. the tendency is most apparent among children and adolescents. this rise in soft drink consumption has raised concerns among health care professionals including dental practitioners. dental problems, such as caries, enamel erosion and corrosion of dental materials, may be associated with soft drink utilization. because orthodontic appliances limit toothbrush access, patients undergoing orthodontic treatment need special oral care and counsel (1). bond failure of brackets during orthodontic treatment is a frequently encountered dilemma. the frequency of this has been found to fluctuate between 0.5 and 17.6 per cent (2-4). a mixture of factors can contribute to bond failure, including poor operator technique, variation in the enamel surface, saliva contamination, bracket properties, masticatory forces and patient behaviour (5-8). acidic and alcoholic foods and drinks in the diet of the patient can also be a causative factor for bond failure (9-11). many studies had evaluated the effect of various soft drinks on the bond strength, adhesive (1)assistant professor. department of orthodontics. college of dentistry. university of baghdad. remnant or the microleakage beneath orthodontic brackets. oncag et al. (10) investigated the effects of coca-cola, sprite and control (artificial saliva) on the resistance of metal brackets to shear forces in vitro and in vivo. they found that both acidic soft drink groups had a reduced debonding resistance in vivo and in vitro compared with their control subgroups. comparison of the debonding resistance between the in vivo and in vitro groups showed no statistical difference. on the other hand, their findings revealed that the areas of defect due to erosion were observed on the enamel surface around the brackets in both the in vitro and in vivo groups. they concluded that acidic soft drinks such as coca-cola and sprite had a negative effect on bracket retention against shearing forces and enamel erosion. ulusoy et al. (12) evaluated the effects of some types of herbal tea on the shear bond strength of orthodontic brackets to enamel surfaces. they found that rosehip fruit tea may be a causative factor in bracket – enamel bonding failure. navarro et al. (13) studied the effects of cocacola and schweppes limón and found that there was no significant difference in shear bond strength and adhesive remnant between the groups. the drinks produced enamel erosion, loss of adhesive and microleakage. j bagh college dentistry vol. 26(3), september 2014 the effect of various orthodontics, pedodontics and preventive dentistry 145 khoda et al. (14) evaluated the effects of pepsi, 7 up, carbonated and non-carbonated yoghurts on the shear bond strength of orthodontic brackets and found that these soft drinks did not decrease the bond strength of the brackets. this study is the first in iraq and conducted to assess the effects of some beverages on the shear bond strength of light-cured orthodontic bonding material (composite) that used to bond stainless steel orthodontic brackets on human teeth, and to verify the site of bonding failure of this material. materials and methods materials teeth fifty human premolars were collected and stored in a solution of 0.1% (weight/volume) thymol. the criteria for tooth selection included undamaged buccal enamel that had not been subjected to any pretreatment chemical agents, e.g. hydrogen peroxide, with no cracks due to the pressure of the extraction forceps and no caries. these teeth were fixed in self-cure acrylic blocks. brackets fifty 0.022” stainless-steel edgewise orthodontic brackets {bionic®} from orthotechnology co., usa with a base surface area 10.9 mm2 were used in this study. beverages five groups of beverages were used in this study. group 1: control (distilled water), group 2: one tiger energy drink, group 3: milk, group 4: green tea and group 5: coffee (table 1). table 1. information about the beverages beverages manufacturer country ph ingredients distilled water poisoning center iraq 7 water one tiger crystal cola co. turkey 6.7 carbonated water, sugar, citric acid, sodium citrate, benzoic acid, taurine, glucuronolactone, caffeine, inositol, caramel, acidity regulators, stabilizer, natural fruit flavors, vitamins b2, b5, b6 and b12. milk kdd co. kuwait 6.7 8.5% non-fat milk solids, 3% butterfat (full cream milk), vitamins d and a, butterfat, purified water, stabilizer and emulsifier. green tea ahmad tea ltd england 6.8 pure china green tea with mint flavoring granules. coffee al-ameed co. jordan 6.4 roasted ground coffee with cardamom methods bonding, immersion and storage the teeth were cleansed and then polished with pumice slurry and rubber prophylactic cups for 10 seconds then thoroughly washed and dried (15). according to the manufacturer’s instructions, 37% phosphoric acid gel was applied for 30 seconds, washed with air water spray for 20 seconds and then dried with oil/ moisture-free air until the buccal surface of the etched tooth appeared chalky white in color. thin uniform coat of resilience® sealant (ortho technology co., usa) was applied by a brush on each tooth surface to be bonded. small increment of resilience® adhesive paste (ortho technology co., usa) then applied onto the bracket back using flat ended instrument. immediately after applying the adhesive to the bracket base, the bracket was placed gently onto the centre of the labial surface using a clamping tweezers. a load of about 300g was attached to the vertical arm of the surveyor to standardize the pressure applied on the brackets during bonding to ensure seating under an equal force and to ensure a uniform thickness of the adhesive and prevent air entrapment which may affect bond strength (16). the excess then removed from around the bracket with sharp scaler. a super led; flash max 2 light cure unit (csm dental aps, denmark) with an optical output well above 4.000 mw/cm2 was used to cure the adhesive. six seconds; three seconds from mesial and three seconds from distal sides were used to cure the adhesive with a minimum separation distance (1-2) mm. (17). the initial ph of each liquid (table 1) was tested using an electronic ph meter (hanna ph 211 microprocessor ph, s.n. 752219, romania). the ph meter was calibrated using phosphate buffer powder prior to testing. to prepare the green tea, one tea bag was added to 250 ml. of boiling tap water and stirred for 5 minutes then the bag removed. the volume of 250 ml. was chosen as this represented the average volume of a typical tea mug. for the coffee, 4 full tea-spoons of coffee were added to j bagh college dentistry vol. 26(3), september 2014 the effect of various orthodontics, pedodontics and preventive dentistry 146 250 ml. of water (with little amount of sugar for both the tea and coffee) and stirred over the fire until boiling. the solution was allowed to cool until it reached 37°c before testing (18). one tiger and milk were used cold, directly from the refrigerator, at each session. the sample were immersed in specific beverages twice daily for 5 minutes with equal intervening intervals then washed and stored in distilled water at 37º c for the reminder of the day. the process continued for 30 days. de-bonding and examination of adhesives remnants the samples were tested for shear bond strength using tinius-olsen testing machine h50kt. a crosshead speed of 0.5mm/minute was used and readings were recorded in newtons. the force was divided by the surface area of the bracket base to obtain the stress value in mega pascal units. the de-bonded brackets and the enamel surface of each tooth were inspected under a stereomicroscope (magnification 20x) to determine the predominant site of bond failure. the site of bond failure was scored according to the classification of wang et al. (19) and as follows: score i: the site of bond failure was between the bracket base and the adhesive. score ii: cohesive failure within the adhesive itself, with some of the adhesive remained on the tooth surface and some remained on the bracket base. score iii: the site of bond failure was between the adhesive and the enamel. score iv: enamel detachment. statistical analyses data were analyzed using spss software version 19. in this study the following statistics were used: a) descriptive statistics: including means, standard deviations, minimum and maximum values, frequency, percentages and statistical tables. b) inferential statistics: including: independent samples ttest: to test any statistically significant difference in the shear bond strength between the control and study groups. in the statistical evaluation, the following levels of significance were used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results and discussion there is increasing community concern in the dental effects of soft drinks, sports drinks, energy drinks and flavored waters due to the escalating consumption by children and adolescents over the last period (20). it has been reported that acidic and alcoholic soft drink consumption during orthodontic treatment decreases the retention of brackets by enamel softening around the brackets (9,10) or adhesive resin/composite resin degradation or softening (11). therefore, patients with fixed orthodontic appliances are advised not to consume acidic soft drinks during treatment (10). in this study, the effect of different beverages on the shear bond strength of light-cured orthodontic composite used to bond stainless steel brackets on human teeth was assessed. the descriptive statistics were shown in table 2. generally the amount of shear bond strength (sbs) was less than proposed by reynolds (20) (6-8 mpa) in all study groups except in control and green tea groups. table 2. descriptive statistics of the shear bond strength (mpa) for the tested beverages beverages mean s.d. min. max. control 7.67 1.08 6.5 9.4 one tiger 5.30 0.69 4.59 6.42 milk 4.77 0.30 4.45 5.18 green tea 7.18 0.48 6.74 7.88 coffee 4.40 1.02 3.16 5.94 comparison the effect of tested beverages on the sbs with the control was demonstrated in table 3. the results showed highly significant difference for milk, coffee and one tiger whereas there was non-significant difference with green tea. table 3. comparison between the control and studied beverages beverages t-test d.f. p-value one tiger 4.521 18 0.001 (hs) milk 6.338 18 0.000 (hs) green tea 1.010 18 0.336 (ns) coffee 5.391 18 0.000 (hs) coffee showed the least mean value of sbs; this is because of its acidic nature (21). one tiger energy drink contains three types of acids namely citric acid, benzoic acid and taurine. these acids in addition to the caffeine and carbonated water (which contains carbonic acid as a result of the dissolved carbon dioxide) have negative effects on the bracketsenamel bonding j bagh college dentistry vol. 26(3), september 2014 the effect of various orthodontics, pedodontics and preventive dentistry 147 by causing enamel demineralization around the brackets (10). this could be explained by the presence of high concentration of refined carbohydrates will promote greater degrees of acid production, in addition to that, citric acid and citrate have the talent to bind to calcium in the tooth keeping the ph low for longer periods of time). oltjen (22) stated that researches supported that a beverage’s composition and total acid content, rather than beverage ph, determine the actual aggression toward enamel. the higher acidity may act as the best plasticizer that accelerates the rate of water sorption by reducing the polymer inter-chain interactions. acidic ph solution has already proved to influence the degradation of the composite which may result a decrease in the mechanical properties (23-27). the solution diffuses into a polymer network and separates the polymer chains creating an expansion that affects the dimensions of the bulk material. in addition, acidic solution may provide a sufficient concentration of protonated protons to induce the hydrolysis of ester portion presents in the resin matrix (28). the reaction may lead to a chain scission process in which polymer chains are cleaved to form oligomers and monomers. the process of plasticization and swelling of the matrix would take place and causes the formation of pores inside the material at the area of organic substances has been released (27). all these circumstances led to increase the rate of water diffusion and therefore higher diffusion coefficients were obtained. green tea was tested for the first time in orthodontics. it has a ph up to 6.8 i.e. it is nearly neutral. it did not cause any decrease in the amount of sbs, so in addition to its benefit to health as anti-oxidant, it has no effect of the sbs. ulusoy et al. (12) found that the shear bond strength had been lowered after exposure to rosehip fruit tea, while other types of herbal tea did not affect the sbs. rosehip fruit tea is rich in ascorbic acid and had the lowest ph in the tested herbal teas. milk used in this study contains fats (full cream). in spite of the bonded teeth were rinsed with profuse amount of water after immersion, the fats in milk would remain on the surface of the bonded teeth since it is insoluble in water. accumulation of fat causes softening of the resin which may weaken the material and reduced the shear bond strength. the most predominant failure site was located at bracket base and adhesive (score i) in milk, coffee and one tiger (table 4). this means that most of composite remained on the tooth after bracket debonding. from this finding, it was apparent that there was a affiliation between lower sbs means values and percentage failure between bracket base and adhesive. on the other hand, cohesive (score ii) and adhesive (score iii) failure could be seen more with increasing sbs mean values (control and green tea groups). this may be accredited to the enamel erosion around the brackets and softening/ degradation of the adhesive resin due to the immersion in the tested beverages; this means that resin penetrated into the undercuts of the bracket base was unable to resist the shear stress when weakened causing bond failure. in conclusion, the acidic and fatty beverages reduced the sbs of the light-cured composite while the green tea did not. orthodontic patients should be instructed to reduce the intake of acidic and fatty beverages to prevent debonding of the orthodontic brackets. further studies are needed to test the effects of the same or other beverages on the shear bond strength of ceramic and sapphire brackets bonded with orthodontic composite (nomix, light-cured or self-etched) and resin modified glass ionomer cement. table 4. frequency and percentage of the adhesive remnant index (ari) in the tested beverages scores beverages control one tiger milk green tea coffee i 5 (50%) 8 (80%) 10 (100%) 4 (40%) 7 (70%) ii 3 (30%) 2 (20%) 0 (0%) 5 (50%) 2 (20%) iii 2 (20%) 0 (0%) 0 (0%) 1 (10%) 1 (10%) iv 0 (0%) 0 (0%) 0 (0%) 0 (0%) 0 (0%) references 1. yip hhy, wong rwkr, hägg u. complications of orthodontic treatment: are soft drinks a risk factor? world j orthod 2009; 10(1): 33–40. 2. zachrisson bu. a posttreatment evaluation of direct bonding in orthodontics. am j orthod 1977; 71(2): 173-89. 3. sunna s, rock wp. clinical performance of orthodontic brackets and adhesive systems: a randomized clinical trial. br j orthod 1998; 25(4): 283-7. j bagh college dentistry vol. 26(3), september 2014 the effect of various orthodontics, pedodontics and preventive dentistry 148 4. reis a, dos santos je, loguercio ad, de oliveira bauer jr. eighteen-month bracket survival rate: conventional versus self-etch adhesive. eur j orthod 2008; 30(1): 94-9. 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(ivsl). 25. wongkhantee s, patanapiradej v, maneenut c, tantbirojn d. effect of acidic food and drinks on surface hardness of enamel, dentine, and toothcoloured filling materials. j dentistry 2006; 34(3): 214–20. 26. zhang y, xu j. effect of immersion in various media on the sorption, solubility, elution of unreacted monomers and flexural properties of two model dental composite compositions. j mater sci mater med 2008; 19(6): 2477–83. 27. örtengren u, wellendorf h, karlsson s, ruyter ie. water sorption and solubility of dental composites and identification of monomers released in an aqueous environment. j oral rehabil 2001; 28(12): 1106–15. 28. nishiyama n, suzuki k, yoshida h, teshima h, nemoto k. hydrolytic stability of methacrylamide in acidic aqueous solution. biomaterials 2004; 25(6): 965–9. (ivsl). http://www.coffeeresearch.org/science/sourmain.htm http://www.oltjenbraces.com/docs/soda-article.pdf 13. athraa f.doc j bagh college dentistry vol. 25(1), march 2013 expression of rankl oral diagnosis 76 expression of rankl by dental cells during eruption of mice teeth lubna k. jassim, b.d.s., m.sc. (1) athraa y. alhijazi, b.d.s., m.sc., ph.d. (2) abstract background : in order for a tooth to erupt, two obvious requirements are needed. first, there has to be alveolar bone resorption of the bone overlying the crown of the tooth such that an eruption pathway is formed. second, resorption of bony crypt and apposition of new one, third, there has to be a biological process that will result in the tooth moving through this eruption pathway.the amniotic sac contains a considerable quantity of stem cells. these amniotic stem cells are multipotent and able to differentiate into various tissues, which may be useful for human application. receptor activator of nuclear factor kappa b ligand (rankl) is concentrated on bone biology, more specifically bone metabolism. rankl plays a vital role in osteoclastogenesis for bone resorption. this study aimed to evaluate the expression of rankl marker by dental cells during eruption of the teeth. materials and methods: : forty eight albino swiss mice of one day old age injected with isolated amniotic stem cells in the anterior region of maxilla (incisors area) other 16 mice injected with saline represents control. sacrifice 4 mice for each period (4, 7, 10, and 13) day old age. the result were studied histologically and immunohistochemistry. results: the present results localized and identified rankl marker in 3 areas of developing tooth of the studied groups includes overlying, surrounding and apical bone. positive rankl with high significant value expressed by osteoclast of overlying bone in amnion group followed by control at day 4. in surrounding bone positive expression of rankl illustrated to be highest in control followed by amniotic fluid at day 10.apical bone shows positive expression of rankl in amniotic fluid group and it records to be the highest value in comparison to studied groups at day 10. conclusion expression marker rankl illustrates that amniotic fluid group has a high expression of rankl in osteoclast surrounding and apical bone areas while control expressed rankl in osteoclast of overlying bone. the present results opened clinical hopes in dental tissue engineering by application of autologous amniotic fluid and chorion cells. key words: rankl, tooth eruption. (j bagh coll dentistry 2013; 25(1):76-81). introduction the amniotic sac is the sac in which the fetus develops in amniotes. it is a tough but thin transparent pair of membranes, which hold a developing embryo (and later fetus) until shortly before birth, the inner membrane is the amnion, contains the amniotic fluid and the fetus and the outer membrane is the chorion that contains the amnion and is part of the placenta (1) .the amniotic sac is filled with amniotic fluid (clear, pale strawcolored fluid, which gives osmotic and physical protection to the embryo during the remainder of its fetal existence). amniotic fluid is a good source of stem cells, its intermediate between embryonic stem cells and adult stem cells; they are multipotent stem cells of mesenchymal origin. amniotic stem cells are able to differentiate into various tissue types such as skin, cartilage, cardiac tissue, nerves, muscle, and bone, and may have potential future medical applications(2) . tooth eruption is a localized process in the jaws which exhibits precise timing and bilateral symmetry. develop within the jaws and their eruption is a complex infancy process during which they move through bone to their functional positions within the oral cavity (3). (1)ph.d. student, department of oral diagnosis, college of dentistry, university of al-anbar. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. rankl is a member of the tumor necrosis factor (tnf) cytokine family which is a ligand for osteoprotegerin and functions as a key factor for osteoclast differentiation and activation(4). rankl also has a function in the immune system, where it is expressed by t helper cells and is thought to be involved in dendritic cell maturation. t cell activation was reported to induce expression of this gene and lead to an increase of osteoclastogenesis and bone loss (5). rankl/rank signaling regulates the formation of multinucleated osteoclasts from their precursors as well as their activation and survival in normal bone remodeling and in a variety of pathologic conditions (6). materials and methods seventy nine albino swiss female mice were used in the present study. those mice were divided into 3 main groups: 1. experimental group: consisted of 16 mice of one day old of age injected with isolated amniotic stem cells in the anterior region of maxilla (incisors area). sacrifice 4 mice for each period (4, 7, 10, and 13) day old age. those 16 mice injected with amnionic cells, 4mice for each scarifying periods. 2. control group: consists of 16 mice of one day old age, injected with normal saline in the anterior incisors region of maxilla. sacrifice 4 mice for each period (4, 7, 10, and 13) day. j bagh college dentistry vol. 25(1), march 2013 expression of rankl oral diagnosis 77 3. pregnant mice group: consists of 15 pregnant mice: 5 out of 15 were used to collect their autologous amniotic fluid at (13 day of gestation period), and stored to be used to their neonatal embryo. while other 10 pregnant mice were scarified to obtain amnionic and chorionic cells from their placenta at (17 day of gestation period). collection of amniotic fluid amniotic fluid was collected from each 5 pregnant mice at 13 day of gestation period (separately) , by using needle aspiration technique, cleaned their skin and wiped with alcohol, then aspirate the fluid using insulin syringe and preserved the amniotic fluid in sterile tube at -80°c until it used. isolation amniotic stem cells from the placenta samples were obtained from 10 pregnant mice at 17 day gestation period to isolate chorion and amnion, after sacrifice the pregnant mice by over dose anesthesia, the embryos inside amniotic membrane with their placenta will excluded immediately. then isolate the embryo from the placenta, and carrying the following procedures: 1. the placenta was cleaned from blood clot with a sterile phosphate-buffered saline solution. 2. removing of amniotic membrane from embryos and put in flask. 3. take a pair of sterile scissors and carefully cut the outside epithelial layer off. the more cut the more stem cells get. the amnion layer is mechanically peeled off the chorion. 4. washing the amnion in phosphate buffered saline solution (pbs) in several times (8-10x) to remove blood. 5. mince the tissue thoroughly with a pair of another sterile scissors. 6. to release amniotic epithelial cells, incubate the minced amnion membrane with trypsin (0.05%) for 10 minutes at 37°c. 7. treating the remaining tissue in another tube of trypsin (0.05%) for 20 minutes at 37 °. 8. pooling the cells from the digests. 9. fuge the filtered cell suspension for 8 minutes at 1200 rpm. 10. washing the cell pellet with pbs and fuge again. 11. counting the cells with a hemocytometer and it is advisable to determine the viability of the cells by exclusion of trypan blue dye, 12. resuspending the pellet in freezing medium by pipetting gently. 13. in order to freeze the cells gradually and safe, place the ampoules in -60°c or less and leave them there for 16-24 hours(7). (all operation was done under sterile condition, using a laminar flow monoclonal antibodies rankl and their detection kit monoclonal antibody (mouse antimouse) us biological rankl (opgl, odf,receptor activator of nuclear factor kappa ligand) immunohistochemistry with detection kit, hrp, mouse tissue, bioassaytm, us biological, ihc detection kit,hrp, mouse primaries (catalog no.17506-06) results ÿ histological and immunohistological tests for detection the expression of cd34 marker were performed on both experimental and control groups for all periods. microscopic evaluation of resorption area of overlying tooth germ of mouse 4 days old treated with amnion shows multiple osteoclast cells stained strong positive with dab of the marker rankl near resorbed bone. figure (1). area of resorbed bone overlying tooth germ of mouse 4 days treated with chorion illustrates expression of rankl on osteoclast cell .figure (2) figure (3) shows multinuclear giant cells in resorption bone area of tooth mouse 7 days old treated with chorion. multiple osteoclast brown color indicating positive histochemical reaction with rankl marker. the bone in the proximal area of the tooth shows rankl expression by strong positive stain in figure (4). view of positive dab stain for osteoclast indicated expression of rankl on apical resorbed area of tooth and proximal area of the tooth of mouse 7 days old treated with amnion. figures (5 and 6). figure(7) shows positive rankl expression in apical resorbed bone area of tooth mouse 10 days old treated with chorion. high power view of immunohistological stain for resorbed bone shows positive rankl expression. figure (8) apical area of tooth for mouse 10 days old treated with amnion shows positive rankl expressed on osteoclast in resorbed bone figure (9). figure (10) illustrates osteoclast cell expressed rankl marker in resorbed bone of tooth mouse 10 days old (control). multiple osteoclast cells in resorbed bone area shows positive rankl marker with positive mononuclear cells either free in adjacent area or in pay like cavity of apical and proximal resorbed bone of tooth mouse of 10 days old treated with amniotic fluid figures (11, and 12). j bagh college dentistry vol. 25(1), march 2013 expression of rankl oral diagnosis 78 ÿ coincidence of expression marker for rankl in studied groups illustrated that amniotic fluid shows high expression of rankl in surrounding and apical areas while overlying area expressed high rankl marker in control group discussion the present results localized and identified rankl marker in 3 areas of developing tooth of the studied groups includes overlying, surrounding and apical bone. the expression of rankl with high significant value by osteoclast of surrounding and apical bone at day 10 in amniotic group could be explained as fallow. 1.the mononuclear cells recruited to the dental sac must fuse to form osteoclasts for resorption of alveolar bone for the eruption pathway(8) . each time correlates with the maximal burst of osteoclastogenesis in each species. 2. a major burst of osteoclastogenesis occurs at day 3 and the molecular regulation of this by the dental sac is critical for eruption. in essence, two molecules known to promote osteoclastogenesis, csf-1 and rankl, are required for this major burst (9). although rankl also is expressed in the dental sac at day 3, its gene expression is not unregulated at this time (10). however, the downregulation of opg at day 3 would result in a ratio of rankl/opg that would favor osteoclastogenesis. the maximal expression of csf-1 at this time would also promote osteoclastogenesis, given that csf-1 upregulates the expression of rank in the osteoclast precursors to enhance cell-to-cell signaling of rankl and rank (11). 3.a minor burst of osteoclastogenesis at day 10 prior to eruption appears to require one or two new genes, as well as an alternation of expression of genes also expressed at day 3 (major burst). specifically, csf-1 expression is reduced at day 10 but its function, in part, appears to be replaced by vascular endothelial growth factor (vegf) which is maximally expressed in the dental sac at days 9–11(12,13) . references 1poloni a, maurizi g, babini l, serrani f, berardinelli e, mancini s, costantini b, discepoli g, leoni p. human mesenchymal stem cells from chorionic villi and amniotic fluid are not susceptible to transformation after extensive in vitro expansion. cell transplant 2011; 20(5): 643-54. 2siegel n, rosner m, hanneder m, freilinger a, hengstschlager m. human amniotic fluid stem cells: a new perspective. amino acids 2008; 35(2): 291-293. 3shuichi yoda, naoto suda, yutaka kitahara, toshihisa komori, kimie ohyama. delayed tooth eruption and suppressed osteoclast number in the eruption pathway of heterozygous runx2/cbfa1 knockout mice. archives of oral biology 2004; 49(6): 435–42. 4 kearns ann e, paul j. kostenuik sundeep khosla. endocrine reviews. receptor activator of nuclear factor κb ligand and osteoprotegerin. regulation of bone remodeling in health and disease 2008; 29 (2): 155-92. 5boyce bf, xing l. functions of rankl/rank/opg in bone modeling and remodeling. arch biochem biophys 2008; 473(2):139-46. 6hanada r, hanada t, sigl v, schramek d, penninger jm. rankl/rank-beyond bones. j mol med (berl). 2011; 89(7): 647-56. 7attilacsordas. tierneylab: new science blog hosted by the new york times. how to isolate amniotic stem cells from the placenta, at home! posted by on january 23, 2007, boing boing. 8luan x, ito y, dangaria s, diekwisch tgh. dental follicle progenitor cell heterogeneity in the developing mouse periodontium. stem cells dev 2006; 15: 595– 608. 9taubman ma, valverde p, han x, kawai t. immune response: the key to bone resorption in periodontal disease. j periodontol 2005; 76(11): 2033-41. 10yao s, liu d, pan f, wise ge. effect of vascular endothelial growth factor on rank gene expression in osteoclast precursors and on osteoclastogenesis. arch oral biol 2006; 51: 596–602. 11arai f, miyamoto t, ohneda o, inada t, sudo t, brasel k, et al. commitment and differentiation of osteoclast precursor cells by the sequential expression of c-fms and receptor activator of nuclear factor kappa b (rank) receptors. j exp med. 1999; 190:1741–54. 12wise ge, yao s. expression of vascular endothelial growth factor in the dental follicle. crit rev eukaryot gene expr 2003a; 13:173–80. 13morsczeck c, götz w, schierholz j, zeilhofer f, kuhn u, möhl c, et al. isolation of precursor cells (pcs) from human dental follicle of wisdom teeth. matrix biol 2005; 24:155–65. j bagh college dentistry vol. 25(1), march 2013 expression of rankl oral diagnosis 79 figure 1: rankl expressed on osteoclast cell (oc) in bone resorption area of overlying tooth germ of mouse 4 days old treated with amnion. dab stain with counter stain hematoxylin, x400. figure 2: rankl expressed on osteoclast cell (oc) in resorbed bone overlying tooth germ of mouse 4 days old treated with chorion. dab stain with counter stain hematoxylin. x400. figure 3: rankl expressed by osteoclast cell (oc) in resorption bone area of tooth mouse 7 days old treated with chorion. dab stain with counter stain hematoxylin, x400 figure 4: positive rankl expression by osteoclast (oc) seen in bone surround the tooth of previous figure (3) dab stain with counter stain hematoxylin,. x400 j bagh college dentistry vol. 25(1), march 2013 expression of rankl oral diagnosis 80 figure 5: rankl demonstrated on osteoclast cell (oc) in apical resorbed area of tooth mouse 7 days old treated with amnion. dab stain with counter stain hematoxylin, x40. figure 6: positive rankl expression seen in resorbed bone (arrow) of surrounding area in the tooth of previous figure (5). dab stain with counter stain hematoxylin, x400. figure 7: positive rankl expression (arrow) seen in apical resorbed bone area of tooth mouse 10 days old treated with chorion. dab stain with counter stain hematoxylin, x200. figure 8: high magnification view of previous figure (7) shows positive rankl marker by osteoclast cells in resorbed bone (arrow). dab stain with counter stain hematoxylin, x400. j bagh college dentistry vol. 25(1), march 2013 expression of rankl oral diagnosis 81 figure 9: positive rankl expressed on osteoclast in resorbed bone (apically) for tooth mouse 10 days old treated with amnion. dab stain with counter stain hematoxylin, x400. figure 10: osteoclast cell expressed rankl marker in resorbed bone of tooth mouse 10 days old (control). dab stain with counter stain hematoxylin, x400. figure 11: multiple osteoclast cell (oc) in apical resorbed bone area shows positive rankl marker with positive mononuclear cells (nearby) (arrow) section related to tooth mouse 10 days old treated with amniotic fluid. dab stain with counter stain hematoxylin, x400. figure 12: mononuclear cells (arrow) presented in pay like cavity of proximal resorbed bone of tooth mouse of 10 days old treated with amniotic fluid. dab stain with counter stain hematoxylin, x400. marwan f.doc j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 84 the clinical approach and treatment of benign and malignant parotid masses marwan g. saied, b.d.s., f.i.c.m.s. (1) abstract background: parotid gland tumors account for 80% of all salivary gland neoplasms, 20% of these are malignant, but in daily clinical practice most parotid masses are operated on before obtaining the final histological diagnosis. this clinical setting further complicates the critical point of parotid surgery, which is the management of the facial nerve. materials and methods: 45 patients underwent parotidectomy for benign and malignant neoplasms. a complete history is collected from the patients with the duration and the site of the tumor, the facial nerve examined and its associations, a medical consultation done for opinion and management. clinical examination with facial nerve was mandatory to avoid any mistakes that may occur. the most significant single parameter in this series of malignancies regarding disease specific survival was the clinical involvement of the facial nerve. also for this reason, as there is no evidence that the facial nerve sacrifice improves prognosis, when it is not clinically involved, every attempt is made to dissect and preserve it. a treatment plan was contemplated regarding nerve preservation for malignancy or with nerve sacrifice. result: this study showed that females (62%) are more affected than males (38%),tumors occur at left parotid gland (65%) more than right parotid gland (35%), a malignancy affected the left parotid gland more than the right one and a malignancy affected females more than males. pleomorphic adenomas are the most frequent benign tumors while the adenocarcinoma most frequent malignant tumors. conclusion: the most complicated situation concerning nerve preservation may be the recurrence of a benign tumor, in particular pleomorphic adenoma, which, in our series, has a higher incidence (62.5%) of permanent facial dysfunction, than surgery with nerve preservation for malignancy (37.5%) and to resects the nerve when is clinically involved and when is totally embedded in a clearly malignant neoplasm with attempt to preserve it in all other. key words: parotid tumors, prognostic factors, facial nerve, malignancy. (j bagh coll dentistry 2016; 28(2):84-91). introduction salivary gland cancers account for approximately 3% of all head and neck malignancies diagnosed in the united states each year; most of these are located in the parotid glands (1). approximately 80% of salivary gland tumors occur in the parotid gland. of these, approximately 7580% are benign. there is no consistent correlation between the rate of tumor growth and whether a tumor is benign or malignant. the majority of benign tumors of the parotid gland are epithelial tumors. most benign parotid tumors present as slow growing, painless masses often in the tail of the parotid gland. in the presence of a parotid mass, physical examination is the first diagnostic tool, since, in most cases it guides the clinician in the right direction (benign versus malignant). ultrasonography (us) is a low-cost modality with high sensitivity in detecting masses in the superficial lobe of the parotid gland. its inability to show part of the deeper parotid lobe is overcomed by computerized tomography (ct) and/or magnetic resonance imaging (mri) which can be particularly useful, as complementary studies, for correct surgical planning. fine-needle aspiration biopsy (fnab) is also indicated by some authors (2-4). (1)maxillofacial surgeon, department of maxillofacial surgery, al-wasity hospital, ministry of health nevertheless, none of these tools provide definitive information regarding the nature and the precise histology of a parotid mass and, furthermore open biopsy of a parotid mass is not recommended due to the risk of seeding of tumors cells in the case of solid malignancy. therefore, what usually occurs in clinical practice is that most parotid masses are operated upon in order to obtain the final histological diagnosis. obviously, lumpectomy must be avoided whenever possible and an oncologically safe surgical approach, involving at least the superficial lobe of the parotid should always be performed also in cases of a clinically benign lesion. surgery of the parotid gland is challenging because the vii cranial nerve, which emerges at the stylomastoid foramen, enters the gland and branches out inside the parotid, defining the superficial and the deep lobe, and must always be identified and dissected when performing parotidectomy. experience shows that most of the primary salivary tumors of the parotid are found directly adjacent to at least one branch of the facial nerve, and rarely, if ever, will the surgeon feel that dissection of the nerve has been useless, also in the case of a clearly benigh mass. furthermore, in the event of recurrence, the risk to the facial nerve increases exponentially, particularly in the relatively frequent event of a multi-nodular relapse of a pleomorphic adenoma (5). j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 85 enucleation alone is, therefore, inadequate for tumors of the parotid gland, on account both of the increased risk of facial nerve lesions and the increased risk of recurrence. some authors believe that the only exception to this rule could be warthin tumors especially when presenting posterior to the facial nerve (6). because there is no evidence that the facial nerve sacrifice improves prognosis at malignancy, when it is not clinically involved, the aim of this study every attempt is made to dissect and preserve facial nerve. materials and methods the data evaluated refer to approximately 45 consecutive patients who underwent parotidectomy for benign and malignant neoplasms between august 2008 and december 2014, at the al-wasity hospital for reconstructive surgery, baghdadiraq. for every patient, personal data were recorded, family history, with particular regard to tumors (salivary or not), and the clinical presentation of the parotid neoplasm. data were collected regarding surgery, complications, complementary and rehabilitative treatments, as well as respective follow-up, by means of revision of charts, direct clinical re-examination and imaging of surviving patients. before surgery, in all patients, staging had been defined by clinical examination and contrast enhanced ct scans of the head and neck, in the presence of a suspicion for malignancy this work-up was completed with imaging of the lungs, contrast enhanced mri of the head and neck and salivary us, fnab. in cases of malignancy, also collected were data regarding tnm classification. as far as concerns clinical presentation of parotid tumors, especially the malignant, the researcher evaluated the involvement of the facial nerve. the masses operated upon were classified, based upon the site of origin, as deep or superficial, and, when they were demonstrated to be malignant, namely primitive (when the parotid was the site of origin of the neoplasm) or metastatic (when parotid localization was a metastasis); based upon the clinical history, as primary or recurrent. as far as concerns surgery, the parotidectomies were classified as superficial or total parotdiectomy with nerve preservation or total parotdiectomy with nerve sacrifice (of the main trunk or branches) and when extension of the resection to other structures was necessary this was recorded. in cases presenting malignancy, follow-up data were collected from the records of the visits performed in the multidisciplinary outpatient unit with the involvement of otolaryngologists (the surgeons), radiation oncologists, and radiologists. in the first year, we recommend a ct scan of the parotid and neck every 4 months, and, in the second year every 6 months; we also suggested a chest ct scan, every year, during follow-up since lung metastases are not infrequent (7-9). results the overall study population comprised 17 males and 28 females (figure 1). overall 35 masses (77.7%) were found to be benign tumors, and 10 masses proved to be malignant tumors (22.2%). for male group 3 were malignant masses while 14 were benign, and for female group 7 masses were malignant while 21 proved to be benign (table 1). 16 masses in the right parotid gland and 29 in the left one (table 2), 9 of them were recurrent and 36 presented as a primary tumor. figure 1: sex distribution 17 males… 28 femle… j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 86 in the "benign" group (range 16-60 years); with the peak was in the 3rd decade and another in the 5th decade (figure 2). regarding the "malignant" group (range 35-63 years), with the peak was in the 6th decade (figure 3). in the case of benign disease, the clinical presentation was usually a swelling of the gland, slowly growing or apparently stable in dimensions. in cases of malignant disease, clinical presentation was as an asymptomatic parotid mass in 5 patients (50%), 3 patients presented with pain, 1 patient with sinus discharge and 1 patient came with facial nerve function deficit. among the benign lesions, the most frequent, by far, were pleomorphic adenomas (almost 91%) , warthin's tumors (almost 9%), 15 cases were in the superficial lobe, 13 cases in the superficial and deep lobes , 4 cases were localized in the deep lobe and 3 cases in the tail of the gland (table 3) and considering malignancies adenocarcinoma 7 cases, adenoid cystic carcinoma 2 cases and lymphoma 1 case, 6 cases of which arose in the superficial and deep lobe and 4 cases arose in superficial lobe (table 4). eight cases of pleomorphic adenomas were recur cases (mostly after enucleation) and one malignant case recur. malignant benign no. of patients sex 3 14 17 male 7 21 28 female 10 35 45 total side no. of tumors left right 29 16 45 65% 35% 100% table 1: numbers of patients with benign and malignant tumors table 2: distribution of parotid tumors figure (2): benign group age no. of patients decades decade 0 1 2 3 4 5 30-39 years 40-49 years 50-59 years 60 years and up no. of patients figure 3: malignant group age j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 87 as far as concerns surgery, in benign lesions, superficial parotidectomy was performed in 14 cases, total parotidectomy with facial nerve preservation in 13 cases (mostly recurrences and primaries of the deep lobe), total parotidectomy with viith nerve sacrificed in 4 cases and enculeation in 4 cases. a trans-mandibular approach was never needed (not even in malignancies), the deep lobe tumors always being resectable using a standard parotidectomy approach by modifying the neck incision when needed. in malignancies, a superficial parotidectomy was performed in 2 cases (20%), total parotidectomy with viith nerve preservation in 2 of cases (20%), and total parotidectomy with viith nerve sacrifice in 3 of cases (30%). in the latter group, only one patient was possible to preserve the superior (orbitofrontal) branch, in second case the operator reconstructed the nerve with a sural graft and a third case buccal branch sacrifice and reconstructed with cervical brunch, 3 patients (30%) not operated upon due to unfitness their medical conditions (table 5). due to the suspected or clinically evident involvement, resection was extended to other structures in 2 cases (overlying skin), submandibular gland: in one case. in 2 cases, in which a wide area of skin had to be resected, we reconstructed the defect with a local flap (figure 4). selective neck dissection in 5 cases, modified radical neck dissection type iii in 2 cases were done. adjuvant therapy was recommended and performed in all the metastatic masses: radiochemotherapy in (3 cases) (60 gy and three cycles of concurrent cddp 100 mg/m on days 1, 22, and 43. overall (4) of patients with a parotid primary tumor underwent adjuvant radiotherapy alone. early complications of surgery were the same both in the case of benign and malignant lesions, sialocele which is a complication of surgery in this series, occurring in 2 patients (4.7%), but was always a self-limiting problem within 2 weeks of local medications, aspiration and compressive dressing. as far as concerns facial nerve, in the cases with anatomical nerve preservation, postoperative facial weakness occurred in all cases (always more evident on the marginal mandibular branch), but only 5 presented a permanent dysfunction (2 malignancies and 3 recurrences of pleomorphic adenoma). two out of these 3 recurrences of pleomorphic adenoma with the permanent dysfunction, actually had a macroscopic lesion of the facial nerve during an extremely difficult dissection from multi-nodular lesions. the most frequent long-term sequel, in this series, was the sensory deficit, probably presented in all patients after parotidectomy (due to section of the great auricular nerve). overall, 15% of patients, in this series, complained of a residual sensory deficit 4 months after surgery. location no. of cases percentage superficial lobe of parotid gland 4 40% superficial and deep lobes of parotid gland 6 60% total 10 100% type no. of cases percentage superficial parotidectomy 16 35% total parotidectomy with preservation of facial nerve 15 33% total parotidectomy with sacrifice of facial nerve 7 16% enculeation 4 9% not operated 3 7% total 45 100% location no. of cases percentage superficial lobe of parotid gland 15 43% superficial and deep lobes of parotid gland 13 37% deep lobe of parotid gland 4 11% tail of parotid gland 3 9% total 35 100% table 3: distribution of benign parotid tumors table 4: distribution of malignant parotid tumors table 5: types of surgical operation j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 88 discussion the causes of salivary gland cancer have not been determined. primary malignant salivary gland histotypes have been classically subdivided into high grade and low grade, based mainly upon the criterion of clinical aggressiveness. some histotypes (such as mucoepidermoid carcinomas) can be either high grade or low grade, while for others the grade was always the same (adenoid cystic carcinoma was always considered high grade). before surgery, it is mandatory for the surgeon to assess the risk of malignancy, because it affects on prognosis and, most of the entire attitude towards the facial nerve, the sacrifice of which may be necessary in solid malignant neoplasms. a suspicion of malignancy, therefore, changes the informed consent, avoiding the legal controversies related to the so-called histological surprises. in researcher opinion, histological surprises should be extremely rare: malignancy can almost always be at least suspected, we experienced only 4 (about 12.5%) histological surprises, with no suspicion of malignancy before the operation, in 2 of these cases the surprise was intra-operative, with difficulties arising in dissecting the nerve (which was anyways preserved) (figure 4). avoiding surprises is achieved by adequate anamnesis, physical examination, imaging and fnab. with the exception of surgical exploration, physical examination remains the most important tool for the experienced diagnostician: a hard mass with fixation is likely to be malignant; nccn guidelines for the management of head and neck cancer suggest some suspicion criteria such as a mass > 4 cm, or arising from the deep lobe (7). the origin in the deep lobe is probably actually a suspicion criterion for malignancy, the frequency of deep lobe masses, in the series presented herewith, is definitely higher in malignant lesions than in benign masses, as confirmed also by another recent study (11). at the first clinical observation of a parotid mass, symptoms and signs such as compromise in nerve function (10-20% of malignant parotid tumors) and/ or facial pain (10-15%) greatly increase concern regarding malignancy (12-14). in this series, facial deficit was practically as frequent as data reported in the literature (14%), while facial pain is definitely more unusual (28%) (figure 5). imaging helps in defining the dimensions, the site of origin, the involvement in adjacent structures which can be difficult to evaluate by means of physical examination (such as the parapharyngeal space). radiotherapy and chemotherapy was performed in those cases of intermediate, high grade or adenoid cystic tumors, with close or positive margins, neural/perineural invasion. disease-specific survival decreases for many years, especially in patients with adenoid cystic carcinoma and malignant mixed tumor, because of distant metastases, which have been reported in approximately 20% of parotid malignancies, figure 4: patient with left parotid encapsulated mass involving buccal branch of facial nerve which was preserved. figure 5: patient with a big left parotid mass j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 89 mainly high grade, and are predictive of poor prognosis (12). in particular, 40% of patients with adenoid cystic carcinoma and 26-32% with malignant mixed tumors demonstrated this feature(8-9). in all these lesions, the site of distant metastases is most often the lung (s). several previous investigations showed that advanced stage, higher histological grade, and submandibular location were prognostic for poorer outcome (8,10,13,15-18) .vii th nerve involvement and positive/close margins in the histological sample are the only clinical parameters, at diagnosis, associated with significant differences in survival in this series. in particular, vii th nerve clinical involvement, at diagnosis, is the most significant prognostic marker in agreement with most of the data in the literature (19-20). the significance of positive/close margins might suggest extending the indications for nerve sacrifice, because the attempt to preserve the nerve sometimes leads the surgeon to leave microscopic (or even macroscopic) disease behind. nevertheless, such a "destructive" attitude with liberal resection of the facial nerve (and of other important structures) no longer dominates surgical philosophy. instead, the surgeon's reliance upon post-operative radiation therapy to manage histological disease and the likelihood of distant metastases make many surgeons reluctant to sacrifice a functioning facial nerve also in the event of a clear malignancy which is difficult to dissect. if the results analyzed more in-depth, we come to share this form of surgical minimalism which has been gaining consent over the last few years. in fact, facial nerve sacrifice, in this series, is associated with a less favorable survival, even if not of statistical significance, because the most significant prognostic parameter in this series, the clinical involvement on vii the nerve, always required resection of this structure, which clearly did not help in improving prognosis. at present, the worst problems in dissecting the nerve, especially in consideration of the benign histology, are encountered in multinodular recurrences of pleomorphic adenomas, in the present series, as in others in the literature (5,21,22). in fact, the incidence of permanent facial dysfunction is markedly higher in cases of recurrence of pleomorphic adenomas (62.5%) than in cases of surgery with nerve preservation for malignancy (37.5%). in researcher opinion, in these cases, the best defense for the surgeon is adequate informed consent of the patients, who must be informed regarding the concrete possibility of facial palsy following an operation for a benign disease. this event is the main argument in favor of extensive surgery (at least a superficial parotidectomy) in pleomorphic adenomas. on the other hand, we do not believe in the usefulness of irradiation in these cases, as it can make subsequent surgery even more complicated, without significant data regarding the clinical effectiveness (21,23) (figure. 6). in this study most of patients operated upon for a malignancy with positive margins had undergone total parotidectomy with nerve sacrifice, which is, therefore, not a solution for the issues of margins. in fact, when available on the histopathological report, the positive margins were found to be usually outside the parotid, due to the involvement of other structures, so probably a more aggressive attitude is warranted on extraglandular structures, possibly resorting more often to reconstructive techniques (figure 7). the opinion was, clinical nerve dysfunction and extra-parotid extension, often not associated with bulky tumors, in researcher experience (figure 8), are, in themselves, expressions of intrinsically more aggressive tumors and can be interpreted as independent prognostic factors. as conclusion; clinical involvement of the vii th nerve and positive margins after resection are the most significant parameters, as they are probably the expression of an intrinsic "biological" potential for malignancy. on the other hand, there is no evidence showing that liberal viith nerve sacrifice improves prognosis, thus our attitude remains to resect the nerve when it is clinically involved and when it is totally embedded in a clearly malignant neoplasm, but to, at least, attempt to dissect and figure 6: patient with a recurrence of multi-nodular pleomorphic adenoma of left parotid gland j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 90 preserve it in all other cases. this guidance is strengthened by the consideration that ultimate diagnosis of malignancy, and definition of histotype, immunohistochemistry) and that, at present, neither clinical and surgical feeling, nor frozen section, or fnab can provide reliable and legally acceptable indications for vii th nerve sacrifice. references 1. spiro r, spiro j. cancer of the salivary glands. in: meyers e, suen j, editors. cancer of the head and neck. new york: churchill livingstone; 1984. 2. zbaren p, schar c, hotz ma, et al. value of fineneedle aspiration cytology of parotid gland masses. laryngoscope 2001; 111: 1989–92. 3. sergi b, contucci am, corina l, et al. value of fineneedle aspiration cytology of parotid gland masses. laryngoscope 2004; 114: 789–98. 4. contucci am, corina l, sergi b, et al. correlation between fine needle aspiration biopsy and histologic findings in parotid masses. personal experience. acta otorhinolaryngol ital 2003; 23: 314–18. 5. redaelli de zinis lo, piccioni m, antonelli ar, et al. management and prognostic factors of recurrent pleomorphic adenoma of the parotid gland: personal experience and review of the literature. eur arch otorhinolaryngol 2008; 265: 447–52. 6. heller ks, attie jn, et al. treatment of warthin's tumor by enucleation. am j surg 1988; 156: 294–6. 7. forastiere aa, ang kk, brizel d, et al. national comprehensive cancer network (nccn). clinical practice guidelines in oncology. head and neck cancers. version 1.2009. 2009. ref type: serial (book, monograph) 8. spiro rh, huvos ag, strong ew. adenoid cystic carcinoma of salivary origin. a clinicopathologic study of 242 cases. am j surg 1974; 128: 512–20. 9. spiro rh, huvos ag, strong ew. malignant mixed tumor of salivary origin: a clinicopathologic study of 146 cases. cancer 1977; 39: 388–96. 10. hollander l, cunningham mp. management of cancer of the parotid gland. surg clin north am 1973; 53:113–19. 11. lin cc, tsai mh, huang cc, et al. parotid tumors: a 10year experience. am j otolaryngol 2008; 29: 94– 100. 12. spiro rh, huvos ag, strong ew. cancer of the parotid gland. a clinicopathologic study of 288 primary cases. am j surg. 1975; 130: 452–9. 13. spiro rh, huvos ag, berk r, et al. mucoepidermoid carcinoma of salivary gland origin. a clinicopathologic study of 367 cases. am j surg 1978; 136: 461–8. 14. frankenthaler ra, luna ma, lee ss, et al. prognostic variables in parotid gland cancer. arch otolaryngol head neck surg 1991; 117:1251–6. 15. spiro rh, huvos ag, strong ew, et al. adenocarcinoma of salivary origin. clinicopathologic study of 204 patients. am j surg 1982; 144: 423–31. 16. borthne a, kjellevold k, kaalhus o, et al. salivary gland malignant neoplasms: treatment and prognosis. int j radiat oncol biol phys 1986; 12: 747–54. 17. matsuba hm, simpson jr, mauney m, et al. adenoid cystic salivary gland carcinoma: a clinicopathologic correlation. head neck surg 1986; 8: 200–4. 18. lima ra, tavares mr, dias fl, et al. clinical prognostic factors in malignant parotid gland tumors. otolaryngol head neck surg 2005; 133: 702–8. figure 7: patient with left parotid encapsulated mass involving the overlying skin resected and reconstructed with local advancement flap. figure 8: a relatively small volume malignancy of the parotid gland in a 35 years old female with static and dynamic facial nerve dysfunction. total parotidectomy with facial nerve preservation was preformed. j bagh college dentistry vol. 28(2), june 2016 the clinical approach oral and maxillofacial surgery and periodontics 91 19. jouzdani e, yachouh j, costes v, et al. prognostic value of a three-grade classification in primary epithelial parotid carcinoma: result of a histological review from a 20-year experience of total parotidectomy with neck dissection in a single institution. eur j cancer 2010; 46: 323–31. 20. cederblad l, johansson s, enblad g, et al. cancer of the parotid gland; long-term follow-up. a single centre experience on recurrence and survival. acta oncol. 2009; 48: 549–55. 21. yugueros p, goellner jr, petty pm, et al. treating recurrence of parotid benign pleomorphic adenomas. ann plast surg 1998; 40: 573–6. 22. valentini v, fabiani f, perugini m, et al. surgical techniques in the treatment of pleomorphic adenoma of the parotid gland: our experience and review of literature. j craniofac surg 2001; 12: 565–568. 23. barton j, slevin nj, gleave en, et al. radiotherapy for pleomorphic adenoma of the parotid gland. int j radiat oncol biol phys 1992; 22: 925–8. bashdar f.doc j bagh college dentistry vol. 25(3), september 2013 effect of canal restorative dentistry 1 effect of canal dryness and flaring on the accuracy of two electronic apex locators bashdar m. hamed, b.d.s., m.sc. (1) ihsan n. kaka, b.d.s., m.sc. (2) abstract background: this in vitro study evaluated the effect of canal dryness and flaring on the accuracy of two electronic apex locators for working length (wl) determination. materials and methods: sixty extracted teeth were used, after access opening was done, the occlusal surface was flattened to create stable reference point. the teeth were randomly divided into two equal main groups of flared and unflared group each one of 30 teeth. the flaring was done with gates glidden drills. the two main groups were further subdivided into two subgroups: dry canal and wet canal using 5.25% sodium hypochlorite groups, electronic wl of each sample was determined using both root zx and i-root apex locator. consequently, histologic wl was determined by shaving the apical 4mm of the root longitudinally and the tip of # 15 k-file was adjusted to the apical constriction under stereomicroscope at a magnification 20x, then the file removed carefully and the length was recorded using digital caliper. the data had been collected from two independent examiners and statistically analyzed using student's t-test. results: the results showed differences between flared and unflared canal, wet and dry, root zx and i-root apex locators, however the differences between them were statistically not significant, in which (p ≥ 0.5) for all situations. conclusion: dryness of the canal, coronal flaring had little effect on the accuracy of electronic apex locators (eals). key words: apex locator, working length, dryness, flaring. (j bagh coll dentistry 2013; 25(3):1-7). introduction accurate determination of working length is essential factor for successful endodontic treatment1. the apical constriction, when viewed under histological cross-sectioning, is the narrowest part of the root canal, and preparation to this mark is thought to result in optimal healing conditions2. it is generally accepted that working length extends from the coronal reference point to the apical constriction. various anatomic studies have determined the apical constriction to fall 0.5 to 1.0 mm from the apical opening of the tooth, or major foramen 3. this measurement is necessary to ensure complete removal of all pulp tissue and necrotic material from within the root canal, but also to prevent extrusion of filling material into surrounding periapical tissue which can behave as an irritant factors2. the radiograph is one of the traditional method for the determination of the root canal length and seltzer et al4were the first to report greater success in terminating cleaning and obturating the root canal system just short 1mm of the radiographic apex, rather than overfilling or underfilling. it is difficult to achieve accuracy of canal length by radiograph, because the apical constriction (ac) cannot be identified in radiograph, and variables in technique, angulations and exposure distort this image and lead to errors 5 (1) senior in conservative dentistry, khanzad specialized center. (2) lecturer. department of conservative dentistry, college of dentistry, hawler medical university. the electronic method eliminates many of the problems associated with radiographic measurements. the most important advantage of apex locator over radiography is that it can measure the length of the root canal to the apical constriction, not to the radiographic apex 6. advances in technology have led to the development of eals that determine the minor diameter position using the “ratio method”. this method allows for simultaneous measurement of impedance at two or more frequencies, a quotient of impedance is then calculated which is expressed as a position of file in the canal 7. however, there are few researches on the effect of combined various clinical factors together on the accuracy of eals. the aims of the study was to evaluate the effect of flaring and dryness on the accuracy of two types of electronic apex locators materials and methods sample collection a total number of 60 extracted teeth were used in this study. distal canal of mandibular first and second molars, and single canal maxillary second premolar, mandibular premolars and palatal canal of maxillary first and second molars were included in the study from the collected teeth. the external tissue debris, calculus, soft tissue and the clotted blood were removed with scaler and tooth brush under running tap water; any metallic restoration was removed with the use of high speed turbine handpiece to avoid interferences with apex locator's reading. the teeth were then inspected for any sign of root fracture and j bagh college dentistry vol. 25(3), september 2013 effect of canal restorative dentistry 2 evidence of complete root formation under sereomicroscope (motic st-39 series) at a magnification of 20x. fractured or cracked roots and roots with immature apices were discarded. all of the roots were stored in a special container containing 0.9% normal saline solution until the required numbers of samples were collected. the normal saline was changed every day to keep the teeth fresh until use. teeth preparation the access opening was done for the collected teeth using a #2 round diamond bur and followed by tapered fissure diamond burs (dentsply maillefer, ballaigus, switzerland) in high-speed turbine hand-piece with water coolant. the occlusal surface of the teeth were also reduced and ground with a diamond grinding wheel (dentsply maillefer, ballaigus, switzerland) to create a flat surface for stable reference points. any remaining caries and metallic restoration were removed to avoid leakage of electrical current. the pulp tissue was extirpated using small size barbed broaches , one for each canal.the patency of the apical foramen was checked using the stainless steel k-file (size # 10) (maillefer instruments, ballaigues, switzerland), in such away that the file must reach the apical terminus and appear from the root apex slightly and tightly (just seen) in combination with 1 ml of normal saline solution via disposable syringe and a 27 gauge endo-eze irrigation needle (endoeze, ultradent products, inc., usa) . any root that did not fulfill this criterion (i.e. k-file not appears from the apex) had been discarded and not included in the study. the canal was irrigated again with normal saline (1 ml via disposable syringe) and dried with paper points. sample grouping the teeth were divided into four groups randomly: each group of fifteen teeth. the groups were consisted of the following: • group 1: electronic working length was determined for the teeth with flaring in dry canal (15 teeth). • group 2: electronic working length was determined for the teeth with flaring in wet canal by using sodium hypochlorite 5.25% (15 teeth). • group 3: electronic working length was determined for the teeth without flaring in dry canal. (15 teeth). • group 4: electronic working length was determined for the teeth without flaring in wet canal by using sodium hypochloride 5.25% (15 teeth). flaring was done for groups 1 and 2 by using gates glidden drills #2, #3, #4, and #5 (antaeos, germany) to the coronal two third of the root in low-speed conventional contra-angle hand piece (w&h, trend, austria). the junction between apical and middle third of the root was calculated by measuring the root from the cemento-enamel junction to the apex of the root and the value was divided by three. crown length (from the coronal reference point at the flattened occlusal surface to the cemento-enamel junction) also measured which was added to the coronal and middle third length of the root, the value which is represented the length from the coronal reference point to the junction of the middle and apical third of the root which is called flaring length. the length which was obtained by removal of crown length from the flaring length was divided by four, that each subsequent gates glidden drills was entered by crown length plus this value the same as for crown down technique. the canal was irrigated with 1 ml of normal saline between each gates glidden drill and after completion of flaring by a 27gauge endo-eze irrigation needle that inserted to the 1/3of the root length and then the canal was dried. stabilization of the teeth to measure the canal length with electronic apex locators, all the samples and lip clip of the apex locator were mounted in an alginate model especially developed to test apex locators, because alginate is a good medium for conducting electricity and its electrical impedance mimic that of human periodontium 8. alginate (blue-print, de trey, surrey, uk) was mixed according to the manufacturer’s instructions and packed in a mold of plastic box with dimensions 240x25x25mm (wxdxh) (custom-made by the researcher) which was marked at each 20 mm by number which correspond to the sample's number that was labeled on the test tube, immediately the corresponding teeth were embedded within the alginate to the level of cervical line, alginate was leaved for 5 minutes to set completely. the lip clip of the apex locater was inserted into the alginate and all measurements were made in an interval of 30 minutes 9. for the first group after flaring the teeth were irrigated with 3 ml of normal saline by irrigation needle that inserted to the 1/3 of the root length and the canal then was dried, and the electronic working length measurement was taken immediately after complete dryness. the dryness was done with size #35 paper points followed by smaller paper points until size # 20 paper point was reached and inserted 1 mm short to the tooth length (i.e. from the coronal reference point to the tip of the root), to determine j bagh college dentistry vol. 25(3), september 2013 effect of canal restorative dentistry 3 the presence of moisture in the canal, four subsequent paper points of size # 20 were used and then the tip of the fifth absorbent point was drawn along the surface of the rubber dam. if the point is moist, it will leave a mark as it removes the powder from the dam, and this procedure was repeated until paper points no longer streak the dam 10. electronic working length measurement was taken after complete dryness. for the second group after flaring was done the teeth were irrigated with 3 ml of sodium hypochlorite 5.25% by an irrigation needle that inserted to the 1/3 of the root length and overflowing sodium hypochlorite from the access opening that contact with the alginate and excess sodium hypochlorite in the pulp chamber was removed by the use of cotton pellet, then electronic working length measurement was taken.sodium hypochlorite was obtained by withdrawing the plunger of the syringe when the hub is immersed into freshly opened clorox bottle which contain 5.25% naocl without any dilution of the solution. for the third group, the canal was not flared, the teeth were only irrigated with 3 ml of normal saline by an irrigation needle that inserted to the 1/3 of the root length and the canal then was dried. the dryness was done as prescribed in first group, electronic working length measurement was taken after complete dryness 10. and finally for fourth (unflared) group after irrigation with 3 ml of sodium hypochlorite 5.25% by a 27gauge endo-eze irrigation needle that inserted to the 1/3 of the root length and overflowing sodium hypochlorite from the access opening that contact with the alginate and excess sodium hypochlorite in the pulp chamber was removed by the use of cotton pellet, then electronic working length measurement was taken. electronic working length determination after mounting the samples and the lip clip of the apex locator, the working length measurements was performed using both root zx (j. morita, japan) and the i-root (s-denti co., south korea) apex locators. both electronic apex locators were adjusted to 0.5 mm accuracy to the apical foramen, and they were used according to their manufacturer's recommendations. with each electronic apex locators, the file holder of the apex locator was attached to size 15 k-file (dentsply, malliefer) and inserted into the root canal that was prepared just before electronic working length measurements were taken which include dryness of the canal or irrigating it with naocl. the file was advanced slowly until the apex was reached and passed on the display of the apex locator, then the file withdrawn slowly until the display showed the apex or 0.5, then the rubber stopper adjusted to the reference point and the file removed, and measured with a digital caliper that have accuracy of 0.01 mm and the reading was recorded for each one of the apex locators. all measurements were repeated 3 times for each sample and the average was taken as the final measurement and recorded. histological working length (real working length) determination after electronic measurement of working length, histologic working length was determined by the following procedure, apical 4mm of the root was shaved using diamond taper fissure bur on high speed handpiece with water cooling, the shaving was done along the long axis of each root in the apical third until file could be seen through a very thin layer of dentin, the procedure was done very carefully, a very thin layer of dentine was removed each time and checked before another layer to be removed. as the file inside the root canal became visible through a thin residual dentine layer, this was manually removed with a sharp probe and the root canal was longitudinally exposed, any tooth that the lumen of the canal has been damaged during sectioning procedure was discarded and a new sample was taken 11. each canal was examined by a two observers under a stereomicroscope (motic st-39 series) at a magnification of 20x, using an iso 15 k-file (dentsply, malliefer) which was inserted into the canal until the tip of the file reached the apical constriction (figure 1), then the rubber stopper adjusted at the coronal reference point and the file was removed carefully in a way that the position of rubber stopper not changed until the length was recorded using digital caliper12. figure 1: file reaching the apical constriction under stereomicroscope data collection the working length has been recorded for each sample and the data colleted and entered into pc pentium 4 using microsoft office excel professional 2003 version 11.0, the mean for the j bagh college dentistry vol. 25(3), september 2013 effect of canal restorative dentistry 4 two operator's reading was determined for histologic wl then the accuracy ratio for each samples were determined by dividing the electronic wl by histologic wl and multiplied by hundred according to the following equation: accuracy ratio = (electronic wl / histologic wl) * 100 values less than 100 meaning that the electronic wl was shorter than the histologic wl (apical constriction), while values more than 100 meaning that electronic wl was longer than histologic wl (apical constriction). while if 100 was obtained meaning that electronic wl was exactly at the apical constriction (electronic wl and histologic wl were the same). statistical analysis the collected data was analyzed using spss version 15 for windows (spss, chicago, illinois, usa), using: 1: descriptive statistics which include means, standard deviations and tables and bar charts. 2: inferential statistics by using paired t-test to compare between each corresponding pair of groups for each treatment. results table (1) refers to the comparison of the accuracy ratio of the root zx and i-root in flared (wet and dry) canal and unflared (wet and dry) canal groups; each including 30 teeth (15 wet and 15 dry) . the mean accuracy ratio of root zx for flared canal and unflared canal groups was (99.75±0.87) and (99.53±3.23) respectively, and there was statistically no significant difference at p ≥ 0.05 between flared canal and unflared canal groups using root zx apex locator (p = 0.66). while the mean accuracy ratio of i-root for flared canal and unflared canal groups was (99.47±1.05) and (99.29±3.21) respectively, and there was statistically no significant difference at p ≥ 0.05 between flared canal and unflared canal groups using i-root apex locator (p = 0.72). table 1. mean accuracy ratio of root zx and i-root in flared (wet and dry) canals and unflared (wet and dry) canal groups devices procedures no. of samples mean accuracy ratio difference from histological wl sd pvalue root zx flared (wet and dry) canals 30 99.75 0.25 0.87 0.66 unflared (wet and dry) canals 30 99.53 0.47 3.23 i-root flared (wet and dry) canal s 30 99.47 0.53 1.05 0.72 unflared (wet and dry) canals 30 99.29 0.71 3.21 the effect of canal dryness on the accuracy of apex locators table (2) shows comparison of the mean accuracy ratio for both apex locators in dry (flared and unflared) canal and wet (flared and unflared) canal groups. for root zx apex locator the dry canal group consist of 30 teeth (15 flared and 15 unflared) with mean accuracy ratio of (100.07±0.81) and the wet canal group consists of 30 teeth (15flared and 15unflared) with mean accuracy ratio of (99.73±1.30). there was statistically no significant difference at p ≥ 0.05 between dry canal and wet canal groups regarding root zx apex locator (p = 0.20), and for i-root apex locator the dry canal group consist of 30 teeth (15flared and15 unflared) with mean accuracy ratio of (99.81±0.87) and the wet canal group consists of 30 teeth (15flared and15unflared) with mean accuracy ratio of (99.47±1.40). there was statistically no significant difference at p ≥ 0.05 between dry canal and wet canal groups regarding i-root apex locator (p = 0.23). j bagh college dentistry vol. 25(3), september 2013 effect of canal restorative dentistry 5 table 2. mean accuracy ratio root zx and i-root apex locators in dry (flared and unflared) canal and wet (flared and unflared) canal groups devices procedure accuracy with ±0.5 to the apical constriction mean accuracy ratio difference from histological wl sd pvalue root zx dry (flared and unflared) canals (30) 100% 100.07 0.07 0.81 0.20 wet (flared and unflared) canals (30) 91.66% 99.73 027 1.30 i-root dry (flared and unflared) canals (30) 96.66% 99.81 019 0.87 0.23 wet (flared and unflared) canals (30) 91.66% 99.47 0.53 1.40 table (3) shows the accuracy of both apex locators in comparison with histologic wl. in which 60 teeth tested by all methods, that the mean and the difference from histological wl for root zx were (19.94±2.05) mm, and (0.02) mm respectively, there was statistically no significant difference at p ≥ 0.05 between the accuracy of root zx apex locator and histologic wl (p = 0.92). in the same way the mean and the difference from histological wl for i-root were (19.88±2.05) mm, and (0.08) mm respectively, there was statistically no significant difference at p ≥ 0.05 between the accuracy of i-root apex locator and histologic wl (p = 0.79). table 3. accuracy of both apex locators compared with histologic wl methods no. mean (mm) difference from histological wl (mm) sd p-value root zx 60 19.94 0.02 2.05 0.92 histologic wl 60 19.96 2.00 i-root 60 19.88 0.08 2.05 0.79 histologic wl 60 19.96 2.00 discussion there are problems with studies for determining the accuracy of apex locators in vitro due to lack of standardization of samples and techniques. in this study, extracted human teeth were used to enhance the reliability of the investigation by duplicating the clinical situation. an attempt was made to make the samples of teeth comparable by selecting roots with single patent root canals, to minimize anatomical variation and allow standardization and to avoid the problems of multiple canals. despite these attempts, natural anatomical variation among the teeth was still a factor, but it was hoped that randomly assigning the teeth to experimental groups and examining each group as a whole rather than looking at individual teeth would give a fair comparison between the groups. in vitro studies on apex locators make use of electro-conductive materials in which the teeth are embedded, thus allowing closure of the electrical circuit, and simulate the clinical conditions13. different embedding media are used like agar solution or gel, suggested by czerw et al14, gelalginate presented by katz et al, 5 and kaufman and katz 15 also saline solution proposed by huang 16 or a sponge soaked with saline solution 17. when various embedding media were compared alginate provided the most coherent results 18.its easy achievement and preparation combined with its low cost make it the medium of choice for use in this situation, many studies used alginate as an electroconductive medium 15,19. the working length should be determined in relation to the apical constriction according to the guidelines of the european society of endodontics 20.the apical constriction could be determined with sufficient accuracy with the light microscope. some investigations have determined the accuracy of measurement of eals however, only a few investigations on the accuracy of eals compared the root canal measurement with the actual root canal length (histologic working length) 21. in present study evaluation of the reliability of the apex locators was done in relation to the ±0.5 mm to the apical restriction that is considered as the strictest acceptable range thus, measurements j bagh college dentistry vol. 25(3), september 2013 effect of canal restorative dentistry 6 attained within this tolerance are considered highly accurate 22. effect of flaring on the accuracy of elas the accuracy of root zx and i-root apex locators regarding the flaring procedure in present study indicates that despite a very little difference between the flared and unflared groups in ewl measurement, there was statistically no significant difference between them . this finding is also in agreement with the results achieved by tinaz et al, (2002) who found little difference in accuracy of root zx with flaring procedure. however, other similar studies reveaedl that flaring procedure increased the accuracy of electronic apex locator with statistically significant difference 23,24. because, flaring of the root canals as used in modern crown-down preparation techniques would increase the accuracy of readings which allow the working length file to reach the apical foramen more consistently as it was found to be true for tactile sensation 25. in contrast to these findings, some researchers stated that coronal flaring did not ensure better or more precise electronic working length measurement9 .interestingly, other researchers found that flaring slightly increased the accuracy of the root zx but at the same time decrease the accuracy of the apex finder afa model 7005 and the bingo 1020. 19 therefore, the canal patency appears to be more important, as dentine debris may disrupt the electrical resistance between the inside of the canal and the periodontal ligament. constant recapitulation and irrigation ensures accurate electronic length readings during instrumentation 25. the effect of canal dryness on the accuracy of apex locators the accuracy of root zx and i-root apex locators regarding dryness of the canal in current study indicates that despite a little difference between the dry and wet groups in ewl measurement there was statistically no significant difference between them. this result is confirmed by the results attained by kang and kim, 26 who used seven different apex locators under various conditions using different irrigation solutions, with the greatest tendency to under record the canal length. they were more accurate in the absence of irrigants (i.e. in the dry condition). this may be due to that the dryness provide lower conductive condition in the apical region which leads to more accurate wl determination by eals (i.e. presence of wetness will lead to increase in electrical conductivity), although, the difference in the accuracies of these electronic apex locators caused by different canal condition were not statistically significant. in spite of that, other researchers found that the difference between wet and dry canals was statistically significant 9,21. furthermore, two other researchers examined the difference in sensitivity between wet and dry canals and found no significant difference between wet and dry canal for wl determination27 .on the contrary, other studies showed that statistically significant differences were found among different canal contents. in the presence of saline (wet) measurements were closer to the apical constriction. while, those carried out in dry canals were shorter 15. it was concluded that the accuracy of eals were negatively influenced by presence of wetness inside the canal, because dryness provide low conductive condition in the apical region although the difference was statistically not significant within the limitations of this in vitro study, the following conclusion can be withdrawn; coronal flaring, dryness of the canal has little effect on the accuracy of eals and their effects were not significant. references 1. welk ar, baumgartner jc, marshall jg. an in vivo comparison of two frequency-based electronic apex locators. joe 2003; 29: 497-500. 2. ricucci d, langeland k. apical limit of root canal instrumentation and obturation, part 2. intl endod j 1988; 31: 394-409. 3. kuttler y. microscopic investigation of root apexes. jada 1955; 50: 544-52. cited by: ebrahim a, wadachi r, suda h. electronic apex locatorsa review. j med dent sci 2007; 54:125-36. 4. seltzer s, soltanoff w, sinai i, biologic aspects of endodontics. iii. periapical tissue reactions to root canal instrumentation. part ii. oral surg oral med oral pathol oral radiol endod 1968; 26: 694-705. 5. katz a, tamse a, kaufman ay. tooth length determination: a review. oral surg oral med oral pathol 1991; 72: 238-42. 6. kobayashi c. electronic canal length measurement. oral surg oral med oral pathol oral radiol endod 1995; 79: 226-31. 7. kobayashi c, suda h. new electronic canal length measuring device based on the ratio method. joe 1994; 20: 111-6. 8. topuz ö, uzun ö, tinaz a, sadik b. accuracy of the apex locating function of tcm endo v in simulated conditions: a comparison study. oral surg oral med oral pathol oral radiol endod 2007; 103: e73-e76. 9. moor rj, hommez gm, martens lc, de boever jg. accuracy of four electronic apex locators: an in vitro evaluation. endod dent traumatlo 1999; 15: 77–82 10. ingle j, bakland l, baumgartner j. endodontics. 6th ed. hamilton: bc decker inc.; 2008. 11. dunlap c, remeikis n, begole e, rauschenberger c. an in vivo evaluation of an electronic apex locator that uses the ratio method in vital and necrotic canals. joe 1998; 24(1): 48-50. 12. haffner c, folwaczny m, galler k, hickel r. accuracy of electronic apex locators in comparison to j bagh college dentistry vol. 25(3), september 2013 effect of canal restorative dentistry 7 actual length an in vivo study. j dent 2005; 33: 61925. 13. lucena-martin c, robles v, ferrer-luque cm, de mondelo jm. in vitro evaluation of the accuracy of three electronic apex locators. joe 2004; 30: 231. 14. czerw rj, fulkerson ms, donnelly jc, walmann jo. in vitro evaluation of the accuracy of several electronic apex locators. joe 1995; 21: 572–5. 15. kaufman ay, keila s, yoshpe m. accuracy of a new apex locator: an in vitro study. int endod j 2002; 35:186-92. 16. huang l. an experimental study of the principle of electronic root canal measurement. joe 1987; 13: 604. 17. goldberg f, marroquin bb, frajlich s, dreyer c. in vitro evaluation of the ability of three apex locators to determine the working length during retreatment. joe 2005; 31: 676-8. 18. baldi jv, victorino fr, bertrandes vr, moraes ig, bramante cm, garcia rb, bernardineli n. influence of embedding media on the assessment of electronic apex locators. joe 2007; 33: 476-9. 19. tinaz ac, maden m, aydin c, turkoz e. the accuracy of three different electronic root canal measuring devices: an in vitro evaluation. j oral sci 2002; 44: 91–5. 20. european society of endodontics. quality guidelines of endodontic treatment. int endod j 1994; 27:115–24. 21. haffner c, folwaczny m, galler k, hickel r. accuracy of electronic apex locators in comparison to actual length an in vivo study. j dent 2005; 33: 61925. 22. ounsi hf, naaman a. in vitro evaluation of the reliability of the root zx electronic apex locator. int endod j 1999; 32:120-3. 23. camargo éj, zapata ro, mederios pl, bramante cm, bernardineli n, garcia rb, moraes ig, duarte ma. influence of preflaring on the accuracy of length determination with four electronic apex locators. joe 2009; 35:1300-2. 24. ebrahim a, wadachi r, suda h. electronic apex locatorsa review. j med dent sci 2007; 54:125-36. 25. gordon m, chandler n. electronic apex locators. int endod j 2004; 37: 425-37. 26. kang ja, kim sk. accuracies of seven different apex locators oral surg oral med oral pathol oral radiol endod 2008; 106: e57-e62 27. nekoofer mh, ghandi mm, hayes sj, dummer pm. the fundamental operating principles of electronic root canal length measurement devices. int endod j 2006; 39: 595-609. j bagh college dentistry vol. 29(1), march 2017 gingival health condition pedodontics, orthodontics and preventive dentistry 132 gingival health condition and salivary physical properties among a group of patients with intermaxillary fixation in tow times intervals (follow up study) entiqal n. jasim al-wazni, b.d s., h.d., m.sc.(1) nadia a. alrawi, b.d.s., m.sc., ph.d.(2) abstract background: one of the methods used in the treatment of maxillofacial fracture is intermaxillary fixation(imf), the most common type is the erich arch bar with interdental wiring. this study was conducted to investigate the impact of intermaxillary fixation on gingival health condition among a group of patients with facial fracture in relation to salivary physical properties. materials and methods: thirty patients with an age range of (17-37) years old with facial fractures and indicated for imf. plaque index and gingival index (loe, 1967) were used to assess both of them before application and after removal of imf. unstimulated saliva sample collection was carried out under standardized conditions according to navazesh and kumer (2008) before imf application and after removal to measure salivary flow rate and viscosity. analysis of data was carried out using spss (version 18). results: a higher mean values of plaque and gingival index were recorded after imf removal than that before imf application, with highly significant changes (p<0.01). in regarding to salivary physical properties, salivary flow rate mean values was lower after imf removal than before imf application with statistically highly significant changes ( p<0.01). concerning salivary viscosity, it has been found that a higher mean values after imf removal than before imf application with highly significant changes (p<0.01). conclusion: the results of current investigation revealed that intermaxillary fixation (arch bar) have a significant effects on gingival health in addition to disturb normal level of certain salivary physical properties. key words: intermaxillary fixation, facial fracture, gingival health condition, salivary physical properties. (j bagh coll dentistry 2017; 29(1):132-138) introduction intermaxillary fixation is a technique used to stabilize a fractured jaw involving maxilla, mandibular complex both for closed reduction and adjuvant to open reduction (1). various types of tooth mounted devices like arch bar, dental and interdental wiring, metallic and non metallic splints are used to achieve intermaxillary fixation (2). the time of intermaxillary fixation which may last for 6 weeks, may be associated with general and oral problems like: weight loss, intense emotional stress, poor oral hygiene, periodontal health problem, loss of tooth vitality, extrusion of teeth, in addition to traumatic ulcer of buccal mucosa ( 3, 4, 5). saliva is the principal defense mechanism and maintaining the health of the oral tissue. adequate salivary physical properties are critical to the maintenance of the health of the oral tissues (6). flow rate play very important function in flushing, dilute substance and neutralizing effect which referred as salivary clearance so higher flow rate faster clearance (7). )1( m.sc. student department of pedodonticsand preventive dentistry, university of baghdad. )2( assistant professor, department of pedodonticsand preventive dentistry, university of baghdad. measuring salivary viscosity is of paramount important since an elevated salivary viscosity was found to be associated with an increased occurrence of oral disease (8). there are no iraqi studies relating salivary composition with oral problems among patients with imf so this study was conducted to investigate the correlation of certain salivary variables among imf patients with oral hygiene condition. materials and methods the study sample included 30 patients , with an age range of 1737years, they were all with confirmed diagnosis of facial fracture and indicated for imf application, the sample was divided according to the age into three age groups: (17-23) years, (24-30) years and (31-37) years. they were examined at the imam alhussein medical hospital in karbala city, department of maxillofacial surgery for their treatment. oral examination was done at the day of imf application. unstimulated salivary samples were collected for assessment of physical properties (flow rate and viscosity). dental plaque and gingival inflammation were assessed at the time of imf application by using loe index (9).the collection of unstimulated saliva sample was performed following the instruction cited by navazsh and kumer (10) . measurement of salivary viscosity by ostwald j bagh college dentistry vol. 29(1), march 2017 gingival health condition pedodontics, orthodontics and preventive dentistry 133 viscometer (11). after six weeks of imf application, and at day of imf removal oral examination and unstimulated salivary sample collection were repeated for study sample. analysis of data was carried out using spss (version 18), and the statistical tests that were used in this study, paired t-test and pearson correlation. results result revealed that a high percentage of patients with facial fracture recorded among (1723) years age group compared to the other two groups as seen in table (1). table (2) represents a higher mean values of plaque index and gingival index among a group of patients with facial fracture after imf removal than before imf application with highly significant changes (p< 0.01). figure (1) illustrates the nominal scales of plaque index among the patients with facial fracture before imf application and after removal. this study revealed that, the higher percentage was cited under the fair plaque scale followed by good plaque scale and poor plaque scale. figure (2) illustrates the nominal scales of gingival index among the patients with facial fracture before imf application and after removal. this study revealed that, the higher percentage was cited under the moderate gingivitis scale followed by mild and sever gingivitis. table (3) presents rates of secretion of unstimulated saliva and viscosity among patients with facial fracture. lower mean values of salivary flow rate after imf removal than before application with highly significant changes (p<0.01). regarding salivary viscosity, higher mean values of salivary viscosity after imf removal than before application with highly significant changes (p<0.01). table (4) referred to the correlation coefficient of plaque index with gingival index in the patients with facial fracture before imf application and after removal. a strong and positive statistically highly significant correlation were existed between plaque index with gingival index in the both times, before imf application and after removal. regarding correlation between dental plaque index with salivary physical properties table (5) illustrates the correlation coefficient between plaque index with salivary flow rate (sfr) and viscosity among patient with facial fracture before imf application and after removal. in general a week negative significant correlation were recorded between salivary flow rate and dental plaque before application and after imf removal. regarding salivary viscosity a positive significant correlation recorded with dental plaque before application of imf and after removal. table (6) demonstrates the correlation coefficient between gingival index with salivary physical properties. the statistical results revealed that there is a negative significant relation between salivary flow rate and gingival inflammation. also there is a negative non significant relation between salivary viscosity and gingival inflammation before imf application and a positive non significant relation after imf removal. table (1): distribution of patients with facial fracture by age table (2): plaque and gingival index (mean and standard deviation) for total sample age (year) no. % 17-23 11 36.666 24-30 9 30.000 31-37 10 33.333 variable before imf application after imf removal statistical test mean±sd mean±sd t-value df p-value (pli) 1.22±0.41 1.72±0.48 -7.483 29 0.000** gi 1.24±0.37 1.78±0.33 -11.071 29 0.000** j bagh college dentistry vol. 29(1), march 2017 gingival health condition pedodontics, orthodontics and preventive dentistry 134 figure (1): plaque severity among patients with facial fracture before application of imf and after removal. * time 1: before application of imf, time 2: after removal of imf figure (2): gingival severity among patient with facial fracture before imf application and after removal. table (3): salivary flow rate and viscosity (mean and standard deviation) for total sample variables before imf application after imf removal statistical test mean±sd mean±sd t-value df p-value salivary flow rate (ml/min) 0.41±0.21 0.32±0.12 3.436 29 0.001** salivary viscosity (poise) 0.04±0.2 0.06±0.02 -11.35 29 0.001** j bagh college dentistry vol. 29(1), march 2017 gingival health condition pedodontics, orthodontics and preventive dentistry 135 table (4): correlation coefficient between plaque index with gingival index for total sample table (5): correlation coefficient between plaque index with salivary flow rate and viscosity for total sample table (6): correlation coefficient between gingival index with salivary flow rate and viscosity for total sample imf application and removal variable salivary flow rate salivary viscosity r p-value r p-value before imf application gi -0.375 0.040* -0.066 0.729 after imf removal gi -0.112 0.555 0.121 0.523 discussion various methods have been used for imf in management of mandibular fracture, one of the most common method in treatment of mandibular fracture is the application of erich arch bar for imf with circumdental wiring, erich arch bars have been used in management of maxilla mandibular fracture since world war 1 (2). however this type of management has been linked with increased risk for oral diseases. the present study (follow up study) was conduct to evaluate the effect of intermaxillary fixation (erich arch bar) on gingival health condition in relation to salivary physical properties. the patient's selected age were between (1737) years old, because most of the patients with motor-vehicle accident with facial fracture with an average age of 20-35 years old (4), in addition to that the most patients were attending to hospital with facial fractures and treating with imf (erich arch bar) with these range. in order to provide evidence between the amount of plaque accumulation and gingival inflammation, gingival index (9), was used to assess gingival health condition, with plaque index (9), these are widely used in epidemiological studies due to their ease, feasibility and validity, in addition to allow the assessment of the state by severity (12). in present study, the higher mean values of gingival index after imf removal may be attributed to the higher mean values of plaque index, with highly significant changes compared to the same group of patients before imf application, these finding was in agreement with other study that increased gingivitis in patients with imf after removal (13). also high significant correlation between plaque index and gingival index among a group of patients with facial fracture before application of imf and after removal, this result was agreed with that record by lone et al (13), reddy (14). unfortunately, there are no previous iraqi studies concerning effect of imf application on gingival health condition to compare with it. however; the present follow up study revealed that higher pli and gi among patients after imf removal than in patients before imf application, imf application and removal variable gi r p before imf application pli 0.730 0.000** after imf removal pli 0.761 0.000** imf application and removal variable salivary flow rate salivary viscosity r p-value r p-value before imf application pli -0.468 0.009** 0.414 0.023* after imf removal pli -0.261 0.164# 0.454 0.012* j bagh college dentistry vol. 29(1), march 2017 gingival health condition pedodontics, orthodontics and preventive dentistry 136 one of explanation may be due to erich arch bar that used for treatment of facial fractures with circumdental wiring, the wire pass below the gingival margin and has disadvantages: injury to gingival tissues, compromised the health of periodontium, rounded wire edges collect food debris cause gingival inflammation and difficulty in maintaining oral hygiene (2). another explanation, patients with facial fracture under emotional stress, which effects on gingival inflammation either by direct influence of stress on immune system (biologic model), through release of stress hormones or by an influence of increase plaque accumulation during stressful experiences period leading to gingival inflammation, as the plaque is the causative factor of gingival inflammation (behavioral model), through the change in life-style such as ignoring self-oral health measures and impropriate cariogenic diet, both models resulting in increasing susceptibility to periodontal diseases (15, 16). in the present study increase gingivitis in addition to plaque accumulation may be due to trauma from wiring which may lead to increase in gingival inflammation, this factor demonstrate the direct impact of imf on gingival condition (17). stooky in 2008 reported that saliva through its flow rate and constituents may play an essential role in maintaining the integrity of the hard and soft oral tissues, and reflecting a physiological status of the oral cavity (18). this study revealed that patients with imf after removal, had a lower mean value of salivary flow rate compare to the same patients before application of imf, these finding may be attributed to several cause, one of them is that salivary flow rate affect by several factor (medication, position of individual, hydration, nutrition) (5, 19). patients with facial fracture usually under analgesic to relief the pain, so these medication play a role in decreasing the flow rate of saliva. also patients with facial trauma most of time with laying position and salivary flow rate is more in standing position than in under laying position (6, 19). patients with trauma had a difficulty in drinking and improper eating this will lead to dehydration, the degree of individual hydration is the most important factor that affect salivary secretion. when the body water content is reduced by 8%, salivary flow rate virtually diminishes to zero, whereas hyper hydration causes an increase in salivary flow rate (19). during dehydration salivary gland cease secretion to conserve water. additionally, other explanation for these findings, patients with facial fracture treated with imf under emotional disturbances (anxiety, stress, and depression) this condition produce transient reduction in salivary flow and change in salivary components (20). another explanation for decrease of salivary flow rate in patients with facial fracture treated with erich arch bar after imf removal is that application of arch bar, patients can not open the mouth this condition resemble to the patients when sleeping so no secretion of saliva and lead to decrease in saliva flow rate (21). lower salivary flow rate among a group of patients after imf removal with highly significant, the result can be explained by that the flow rate of saliva may play important role in relation to plaque accumulation, so decrease in flow rate of saliva lead to decrease of washing action of saliva which lead to oral dryness as well as decrease of protective constituents (21). salivary flow rate in this study was negatively correlated with dental plaque and gingival indices. this result was in agreement with iraqi studies found an inverse relation between salivary flow rate and gingival index (2224), this could be attributed to the fact that saliva exerts a major influence on plaque initiation and maturation (25). salivary viscosity is a quality or state of being viscous, relates to the glycoprotein content of saliva (26, 27). viscoelastic properties are essential for humidification and lubrication which providing mucosal integrity (28). an increased salivary viscosity increased oral health problem (8, 29). in the present, investigation salivary viscosity is higher after imf removal compare with the mean values before imf application, an explanation of increase in salivary viscosity in addition to the factor related with decrease salivary flow rate, is that patients with facial fracture suffer from emotional disturbance (anxiety, stress) so, sympathetic stimulation produces little saliva but of high protein concentration (30-32). however, this elevation in the total protein could be attributed to sympathetic activation during stress as the sympathetic innervations of the salivary glands controls protein secretion (33, 34). however no significant correlation has been recorded between salivary viscosity ad gingival inflammation. this result in agreement with al-awadi and yas (23,35). data of present study show a positive correlation between plaque index and salivary viscosity. j bagh college dentistry vol. 29(1), march 2017 gingival health condition pedodontics, orthodontics and preventive dentistry 137 references 1. coletti d, salama a, caccamese j. application of intermaxillary fixation screws in maxillofacial trauma. j oral maxillofac surg 2007; 56(9): 1746 -1750. 2. chandan s, ramanojam s, comparative evaluation of the resin bonded arch bar versus conventional erich arch bar for intermaxillary fixation. j maxillofac oral surg 2010; 9: 231 5. 3. booth p, schendel s, hausamen j. maxillofacial surgery. 2nd ed. churchill livingston, 2007. 4. hupp j, ellis e, tucker m. contemporary oral and maxillofacial surgery. 5th ed. mosby, elsevier, 2008. 5. sheet w, hassouni m. changes in the body weight, serum (sodium, potassium and serum albumin) after intermaxillary fixation in traumatized and obese patients ( a comparative study). alrafidain den j. 2012; 12(1): 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مجموعة من ا الفكين على الحالة الصحية لللثة تهدف الدراسة إلى بيان تأثير تثبيت أهداف الدراسة: اللعابية. الفيزيائية الفك السفلي والفكين, تم عالجهم عن طريق تثبيت سنة, يعانون من كسور في الوجه 71-71العينة ثالثون مريض للفئة العمرية المواد وطرق العمل: تتضمن ظل ( قبل التثبيت وبعد رفع التثبيت. تم جمع عينات اللعاب غير المحفز فيloe, 1967بالفك العلوي. تم قياس الصفيحة الجرثومية والتهاب اللثة باستخدام ) اجري تحليل البيانات اللعاب واللزوجة.قياس معدل تدفق لتثبيت, تم( قبل التثبيت وبعد رفع ا (navazesh and kumer, 2008ظروف موحدة وطريقة .71االصدار spssنظام باستخدام مع تغيرات معنوية منه قبل وضع التثبيت التثبيتى بعد إزالة اظهرت نتائج الدراسة الحالية ان متوسط قيمة الصفيحة الجرثومية كان اعلى بين المرض النتائج: . p<0.01)معنوية عالية ) مع تغيرات تثبيتمنه قبل وضع ال التثبيتبعد إزالة . متوسط قيمة التهاب اللثة كان اعلى بين المرضىp<0.01)عالية ) , اظهرت الدراسة عدم وجود اي ارتباط بين p<0.01)مع تغيرات معنوية عالية )التثبيت قبل وضع منه لتثبيتا معدل تدفق اللعاب غير المحفز كان اقل بعد ازالة بالنسبة للعالقة بين التهاب اللثة و معدل تدفق اللعاب لتثبيت . مع وجود عالقة سلبية عالية قبل وضع اتثبيت الصفيحة الجرثومية ومعدل تدفق اللعاب بعد إزالة ال ربط وبعده.هناك ارتباط سلبي قبل وضع ال أظهرت الدراسة وجود عالقة بين لزوجة اللعاب و .p<0.01)مع تغيرات معنوية عالية ) منه قبل وضع التثبيت تثبيتمعدل اللزوجة كان أعلى بعد إزالة ال بعد رفعه.و التهاب اللثة قبل التثبيت لعاب ومع عدم وجود عالقة بين لزوجة الوبعد رفعه تثبيت ة الجرثومية قبل الالصفيح .ائيةباالضافه إلى اإلخالل بالمستوى الطبيعي لمكونات اللعاب الفيزي اثار جانبية على صحة اللثةبحث الحالي إن لتثبيت الفكين االستنتاجات: أثبتت نتيجة ال 20basma f.docx j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 121 correlation between visfatin and creatine kinase levels with periodontal health status of patients with coronary atherosclerosis and chronic periodontitis basma r. omer, b.d.s. (1) maha sh. mahmood, b.d.s., m.sc. (2) abstract background: visfatin is a novel adipokine that mainly secreted by visceral adipose tissue, had an important role in inflammation and immune system. creatine kinase (ck) which is an enzyme that is involved in energy metabolism, found in large amounts in myocardium, brain and skeletal tissues. this study is carried out to evaluate the periodontal health status of the study groups (chronic periodontitis and chronic periodontitis with coronary atherosclerosis) and control groups, to measure the salivary levels of visfatin and creatine kinase in these groups and compare between them, and to determine the correlations between salivary visfatin and creatine kinase levels with the periodontal parameters in the three groups. materials and methods: eighty participants, males and females were recruited in this study with age ranged from (3060) years, they were divided into three groups: the first study group was the chronic periodontitis group (n=30), the second study group was chronic periodontitis and coronary atherosclerosis (n=30) and the control group(n=20) which was healthy systemically with healthy periodontium. periodontal health status was determined by measuring plaque index(pli),gingival index (gi), probing pocket depth(ppd), bleeding on probing (bop) and clinical attachment level (cal),salivary samples were taken from each participants, salivary visfatin levels were determined by enzyme-linked immune-sorbent assay(elisa) while the activity of salivary creatine kinase was determined spectrometrically by using the international federation of the clinical chemistry (ifcc) method on hitachi 911 automatic analyzer. results: the results of the study showed that the mean values of pli, gi, visfatin, creatine kinase and the percentages of sites according to ppd scores, cal scores, bop were higher in the second study group with chronic periodontitis and coronary atherosclerosis than in the other groups with highly significant differences between the groups at (p≤0.01). also by using pearson correlation coefficient, salivary visfatin levels were correlated positively with all clinical periodontal parameters with a strong and positive correlation between salivary visfatin levels and cal scores and ppd scores. salivary creatine kinase levels were correlated positively with all clinical periodontal parameters with a strong and positive correlation between its levels and mean values of gi and percentages of bop. conclusion: the present study showed that salivary visfatin can be used as a marker for the development of coronary atherosclerosis and its levels are associated with the degree of periodontal destruction and showed that creatine kinase may be used as a marker for coronary atherosclerosis and chronic periodontitis. keywords: visfatin, creatine kinase, periodontitis, atherosclerosis. (j bagh coll dentistry 2016; 28(3):121-125). introduction chronic periodontitis is one of the most commonly occurring disease in human which had profound effect on person health (1). it is considered as a major health problem that if left untreated may become a risk factor for many systemic diseases such as cardiovascular disease (2). although the development of periodontitis require the presence of bacteria, it also require the presence of susceptible host, host response is usually mediated by neutrophil cells, lymphocyte and macrophage (3). these cells were stimulated to produce many cytokines and enzymes that contribute to further tissue destruction (4).coronary artery disease is the most common type of heart diseases, coronary atherosclerosis which occur as a result of narrow (1)master student. department of periodontics, college of dentistry, university of baghdad. (2)professor, department of periodontics, college of dentistry, university of baghdad. ing and hardening of the arteries that supply the heart as a result of build of atherosclerotic plaque (5). it is characterized by local and systemic host responses as cells such as b and t lymphocyte and macrophage which had an important role in the pathogenesis of this disease by secretion of cytokines and enzymes (6). the presence of inflammatory source in the oral cavity may worsen the atherosclerotic process by stimulation of cellular and humoral mediated immune response (7). the possible linking mechanisms between periodontitis and coronary atherosclerosis are by sharing the same risk factors, role of immune cells, increase in wbc counts, inflammatory mediators and the role of bacterial lipopolysaccharides (8). adipose tissue is the main site for lipid storage, there are two types of adipose tissue, white and brown adipose tissue. the adipose tissue release many biologic active proteins with low molecular weight, these were named as j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 122 adipokines (9). these adipokines are important in lipid and glucosehoemostasis and many other functions (10). one of the newly discovered adipokines is visfatin (visceral fat cytokine), which is 52 kilodalton (kda) protein. visfatin was first describedaspre-b cell colony enhancing factor and nicotinamide phosphoribosyl transferase (nampt) because it is involved in nicotinamide adeninedinucleotide synthesis from nicotinamide (11), it has insulin-mimetic properties(12). visfatin role in immunity was explained as its gene was expressed in lymphocyte cells and it also induced the production of interlukins such as il-1b,il-6 and tumor necrosis factor which are pro-inflammatory cytokines and il-1α and il-10 which are anti-inflammatory cytokines(13) ,and it had an important roles in metabolism, aging and inflammation(14). there is a direct association between visfatin levels and increased cardiovascular disease(15) and it had a role in many pathophysiological processes that eventually lead to cardiovascular disease such as hypertension and atherosclerosis. however, whether visfatin is a friend or not in these diseases remain unclear (16). visfatin concentrations increased with the severity of periodontal diseases from healthy periodontium to gingivitis to periodontitis (17). creatine kinase (ck) is 82 kda enzyme that found mainly in tissue with high energy demands especially skeletal muscle, brain and myocardium (18). the increased levels of serum ck were associated with muscle disruption, cell damage and necrosis (19). it was considered as a marker of cardiovascular disease (20), it was also used to detect periodontal diseases and determine the success of periodontal treatment (21). because there is no information about visfatin levels in saliva of patients with coronary atherosclerosis and its association with its levels in chronic periodontitis, therefore, it was decided to conduct this study. materials and methods the study sample was consisted of eighty participants with age range of (30-60) years from both genders. the participants recruited for the study were patients who attended to baghdad teaching hospital, iraqi centre for heart diseases in ghazyal-harery hospital for catheterization as well as patients from the department of periodontics in the teaching hospital of college of dentistry, university of baghdad. all participants were informed about the aims of the study orally and by written as a written informed consent was assigned by all participants. the participants were divided into three groups: 1. study group i (cp):consisted of thirty participants with chronic periodontitis only without history of any systemic diseases.( patients with chronic periodontitis should have at least 4 sites with pocket depths ≥4mm with clinical attachment loss of(1-2)mm or greater ,this was measured according to lang et al(22). 2. study group ii (cp+ca):-consisted of thirty patients with chronic periodontitis and coronary atherosclerosis (c.a) who had heart attack since no more than six months and diagnosed for c.a by catheterization and they were on (plavix drug 75 mg)they should have at least 4 sites with pocket depths ≥4mm with clinical attachment loss of(1-2)mm or greater, this was measured according to lang et al (22)admitted to iraqi center for heart diseases for treatment. 3. control group: consisted of twenty patients who were healthy systemically and periodontally. sample of 5ml of whole unstimulated saliva was taken from each patient. following this full examination of clinical periodontal parameters (pli, gi, bop, ppd and cal) was done by 1. assessment of soft deposits by plaque index system by silness and loe (23). 2. assessment of gingival inflammation by gingival index system by loe (24) 3. assessment of bleeding on probing according to salvi (25). 4. assessment of probing pocket depth by salvi (25). a scale was designed for ease of estimation. score 0: 1-3 mm score1: 4-5mm score 2: 6mm and greater 5. assessment of clinical attachment level by (26) cal readings were divided into 3 scores (27). score 1: 1-2 mm score2: 3-4 mm score 3: 5mm and greater saliva was centrifuged at 2000 r.p.m for ten minutes, the resultant supernatant was aspirated and, then put into two eppendorff tubes (one for visfatin elisa kit and the other for creatine kinase kit)and kept frozenat -20ºc until analyzed. salivary visfatin level was determined by the enzyme-linked immune-sorbent assay(elisa) in the teaching laboratory of medical city in baghdad while the activity of salivary ck was determined spectrometrically by using the international federation of the clinical chemistry (ifcc) method on hitachi 911 automatic analyzerin the laboratory of poison centre of the specialized surgeries hospital. j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 123 statistical analysis was done using mean, sd, percentages, anova test, chi-square test, and correlation coefficient (r). results the present study showed that the study cp+ca group had the highest mean value of pli and gi among the three groups (as shown in table 1), the mean and sd were (2.48±0.17), (2.2±0.15) then followed by cp group, the mean and sd were (2.08±0.52), (1.6±0.38),and finally the control group showed the lowest mean and sd (0.1±0.04), (0.07±0.03). also in table 1, percentages of bleeding on probing sites were higher in cp+ca group than in cp group which were 83.56% and 52.7 % respectively. regarding ppd scores, it was clearly shown in table 2 that the numbers and percentages of sites with score 1 and score 2 were higher in cp+ca group than in cp group while the number and percentages of sites with score 0 were higher in cp group than in cp+ca with highly significant differences at p<0.01 when chi-square test was applied for comparison (as shown in table 3). table 2 also showed that the numbers and percentages ofsites with score 2 of cal and score 3 were higher in cp+ca group than in cp group while the number and percentages of sites with score 1 were higher in cp group than in cp+ca with highly significant differences at p<0.01 when chi-square test was applied for comparison as shown in table 3. the analysis of visfatin and ck in table 4 showed that the study cp+ca group with the highest mean value among the groups of the study, the mean and sd were (1052.4±132.4) for visfatin and (11.55±1.3) for ck and then followed by cp group (457.8±208.7) and (4.94380±1.4), and finally the control group with the mean and sd (0.62±0.2), (1.6±0.2)which had the lowest mean value. salivary visfatin and creatine kinase levels were correlated positively with the mean values of gi and percentages of bop as shown in table 5. also salivary visfatin levels were correlated positively and strongly with all ppd scores (as shown in table 6) and cal scores as shown in table 7. table 1:the mean values and standard deviation of pli and gi and the percentages of sites with bop among the groups groups pli gi bop mean sd mean sd score 0 score 1 cp 2.0827 0.5 1.62800 0.3 47.3% 52.7% cp+ca 2.4833 0.1 2.22000 0.1 16.44% 83.56% control 0.1094 0.04 0.07010 0.03 table 2:number and percentages of sites according to ppd and cal for the study groups group ppd cal score 1 score2 score3 score 1 score 2 score 3 no % no % no % no % no % no % cp 439 15 2337 79.9 146 4.9 1169 40 1461 50 292 10 cp+ca 30 1 2767 94 147 5 294 9.9 2356 80.2 294 9.9 table 3:comparison between study groups according to ppd and cal scores group chi-square test p-value sig ppd cal ppd cal ppd cal cp 392.83 733.12 <0.0001 <0.0001 hs hs cp+ca table 4: the mean values of salivary visfatin and ck among the groups of the study groups visfatin ck mean sd mean sd cp 457.8 208.7 4.94380 1.4 cp+ca 1052.4 132.4 11.55 1.3 control 0.62 0.2 1.6 0.2 j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 124 table 5: pearson's correlation coefficient (r) between visfatin and ck with periodontal parameters (pli,gi,bop). visfatin pli gi bop r p-value sig r p-value sig r p-value sig cp 0.4 0.01 hs 0.1 0.49 ns 0.002 0.9 ns cp+ca 0.7 0.000 hs 0.5 0.003 hs 0.14 0.4 ns control 0.9 0.000 hs 0.7 0.000 hs ck cp 0.4 0.009 hs 0.9 0.000 hs 0.7 0.000 hs cp+ca 0.6 0.000 hs 0.9 0.000 hs 0.5 0.004 hs control 0.2 0.38 ns 0.2 0.3 table 6: pearson's correlation coefficient (r) between ppd scores and the levels of salivary ck enzyme and visfatin for each study group parameter groups scores r p-value sig ppd cp score 0 visfatin 0.793 0.000 hs ck 0.04 0.8 ns score 1 visfatin 0.9 0.000 hs ck 0.137 0.471 ns score 2 visfatin 0.754 0.000 hs ck 0.03 0.85 ns cp+ca score 0 visfatin 0.12 0.52 ns ck 0.26 0.15 ns score 1 visfatin 0.73 0.000 hs ck 0.01 0.95 ns score 2 visfatin 0.74 0.000 hs ck 0.397 0.03 ns table 7: pearson's correlation coefficient (r) between cal and the levels of salivary ck enzyme and visfatin for each study group parameter groups scores r p-value sig cal cp score 1 visfatin 0.56 0.001 hs ck 0.09 0.6 ns score 2 visfatin 0.79 0.000 hs ck 0.09 0.6 ns score 3 visfatin 0.602 0.000 hs ck 0.11 0.5 ns cp+ca score 1 visfatin 0.893 0.000 hs ck 0.17 0.35 ns score 2 visfatin 0.92 0.000 hs ck 0.28 0.12 ns score 3 visfatin 0.89 0.000 hs ck 0.2 0.3 ns discussion periodontitis and coronary atherosclerosis are multi-factorial diseases with an onset in early childhood while their manifestation may appear in adulthood (28).these two entities affect each other as cardiovascular diseases is one of the most important diseases caused or exacerbated as a result of periodontal disease .both of these diseases lead to the release of inflammatory mediators from the damaged tissue into saliva and other biological fluid (29). the mean values of pli, gi, visfatin, creatine kinase and the percentages of sites according to ppd scores, cal scores, bop were higher in the second study group with chronic periodontitis and coronary atherosclerosis than in the other groups with highly significant differences between the groups at (p≤0.01). visfatin play a role in increasing the expression of pro-inflammatory cytokines such as tnf α and mmp and other biomarkers in response to the presence of inflammation (30). ck is an intracellular enzyme that participates in many metabolic processes in the cells of tissue j bagh college dentistry vol. 28(3), september 2016 correlation between oral and maxillofacial surgery and periodontics 125 and it was released in large amount from the damaged cells of periodontal tissue in response to inflammation and it is considered as a reflection of metabolic changes in the gingiva and periodontium during inflammation (31). the results of this study showed that there was an increase in salivary visfatin and ck levels with the presence of periodontitis and coronary atherosclerosis. it was also established a strong positive correlation between ck activity and the mean values of gi and percentages of bop and a strong and a positive correlation between visfatin levels and ppd and cal scores. in a conclusion, ck and visfatin can be used as a marker of periodontitis and c.a so it may contribute in identification of higher risk individuals as well as lead to new therapeutic approach. references 1. pihlstrum bl, michalowic z, jonson nw. periodontal disease. the lancet 2005; 94: 1809-20. 2. bhardawaj a, bhardwaj sv. periodontitis as a risk factor for cardiovascular disease with its treatment modalities. j mol pathophsiol 2012; 1(1):77-83. 3. manuela r, ronaldo l, ricardo gf, carlos marcelo da silva figeredo. braz dent j 2015; 25:1-5. 4. silva ta, garlet gp, fukada sy, saliva js, cunha fq. chemokines in oral inflammatory diseases: apical periodontitis and periodontal disease. j dent res 2007; 86: 306-19. 5. mearns bm. non invasive imaging 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resisiten and visfatin: regulators of insulin sensitivity, inflammation and immunity. endocr regul 2010; 44: 25-36. 13. moschen ar, gerner rr,tilg h. pre-b cell colony enhancing factor in inflammation and obesity –related disorders. curr pharm des 2010; 16(17):1913-20. 14. wang ls, yan jj, tang np, zhu j, wang ys, wang qm, tang jj, wang mw, jia ez, yang zj, hang j. a polymorphism in the visfatin gene promoter is related to decreased plasma levels of inflammatory markers in patients with coronary artery disease. mol biol rep 2011; 38(2): 819-25. 15. filippatos td, tsimihodimos v, derdemezis cs, tselepis ad, elisaf ms. increased plasma visfatin concentration is a marker of an atherogenic metabolic profile. nutr metab cardiovasc dis 2013; 23(4): 3306. 16. wang cp, leereny, yu th, wei chin hung, cheng an chiu,li fen lu,hui ling hsu .increased epicardial adipose tissue volume in coronary artery calcium and coronary atherosclerosis. acta cardiol sin 2012; 28:19. 17. pradeep ar, raghavendra nm, sharma sp, raju a, kathariya r, rao ns, naik sb. association of serum and crevicular visfatin levels in periodontal health and with type 2 diabetes mellitus. j periodontal 2012; 83(5): 629-34. 18. marianne f, scott m, julien s, bickerstaff gf. creatine kinase and exercise related muscle damage implication for muscle performance and recovery. j nutrition and metabolism 2012; 3:26--5. 19. maffuli pbn, limongelli fm. creatine kinase monitoring in sport medicine. br medical bulletin 2007; 81: 209-30. 20. nehran r, dangas g, gary s, mintz, alexandra j, augusto d. atherosclerotic plaque burden and ckmbenzyme elevation after coronary interventions. med 2006; 144: 249-56. 21. paknjad m, rezaei a. salivary biochemical markers of periodontitis. rom j biochem 2013; 50: 129-46. 22. lang np, bartold pm,cullinam m, et al. international classification workshop. consensus report: chronic periodontitis. annals of periodontol 1999; 34: 3-6. 23. silness p, loe h. periodontal disease in pregnancy. acta odontol scand1964; 22:121. 24. loeh. the gingival index, the plaque index and the retention index system. j periodontal 1967; 38(6): 610-6. 25. salvi ge, lindhe j, lang np. examination of patients with periodontal diseases. clinical periodontology and implant dentistry. 5thed. copenhagen: munksggaard; 2008. pp. 67-89. 26. american academy of periodontology. tobacco use and the periodontal patient. j periodontal 1999; 70:1419-27. 27. american academy of periodontology (aap).parameter on comprehensive periodontal examination. j periodontol 2000; 71(5): 847-8. 28. bartova j, sommerova p, lyuya-mi y, mysak j, prochazkova j, duskova j, janatova t, podzimek s. periodontitis as a risk factor of atherosclerosis 2014; 6:70-89. 29. trivedi d, chhaya t. salivary proteome in periodontal diagnosis. international j pharma and biosci 2012; 2: 5-9. 30. olszanecka g, linianowicz m, kocelak p, janowska j, skorupa a, nylec m, zahorska m. plasma visfatin and tumor necrosis factor –alpha level in metabolic syndrome. kardiol pol 2011; 69(8):802-7. 31. maadani m, ghazae s, mirri ea, ghadrdoost b, heidaralia m. diagnostic accuracy of post procedural creatine kinase, mb form can predict long term outcomes in patients undergoing selective percutaneous coronary intervention. res cardiovasc med 2014; 3(1):e11738. j bagh college dentistry vol. 30(3), september 2018 evaluation of 59 evaluation of the efficacy of ultrasound in the diagnosis of cervical lymphadenopathy shahad d. ali b.d.s. (1) taghreed f. zaidan b.d.s, m.sc., ph.d. (2) mohammed a. mahdi m.b.ch.b;f.i.b.m.s. (3) abstract background: cervical lymph nodes are prone to involved by a number of pathologic processes. they are common sites for lymphoma, metastasis, and reactive enlargement in a number of conditions. aims of the study:-clinical evaluation of patients with cervical lymphadenopathy. differentiation between benign and malignant lymph nodes by means of ultra sounds (us) and correlate the us findings with cytological and/or histopathological findings of cervical lymph nodes. subjects, materials and methods:-the present study was carried out over a period of 6 months and included 81 patients of different age groups presenting with cervical lymphadenopathy. each patient was examined clinically, then comprehensive sonographic examination of the neck for cervical lymph nodes (l.ns) was performed using ultrasound machine (ge wipro proseries). the scanning was performed with the patient in the supine position, and with the neck hyperextended using a pad or pillow under the shoulders in order to provide optimum exposure of the neck. the parameters considered in this study include: site, long axis (l), short axis (s), shape index (s/l), echotexture, margins, ancillary features like calcification, necrosis, matting and surrounding tissue changes. these findings were correlated with fine-needle aspiration cytology, core and excisional biopsy. the nodes were classified as benign (reactive) and malignant (lymphomatous and metastatic). results: the age of patients ranged from five to seventy five years, they were 45 male and 36 females, there was association between family history and development of malignant lesions. regarding clinical evaluation, and according to consistency, (13) hard l.ns were malignant and (1) was benign, (27) rubbery l.ns were malignant and 40 soft l.ns were benign. according to fixation to underlying structure, forty one l.ns were fixed, (40) were malignant and (1) was benign. forty l. ns were not fixed, on histopathological evaluation all were benign. on us, the results showed that malignant lymph nodes are mostly appeared as round shape, homogenous echotexture, nodal shape (s/l ratio) accurate for differentiating benign from malignant lymph nodes. most of the malignant nodes had welldefined borders. calcifications, necrosis, matting, were characteristically found in benign lymph node. a combined ultrasound-guided and fine-needle aspiration (fna) diagnosis had a high accuracy as compared with situations in which they were used alone. conclusions: sonographic findings have a high accuracy in differentiating benign from malignant cervical lymph nodes. an ultrasound scan can be used as the first-line imaging tool in the diagnostic evaluation of cervical lymphadenopathy. using gray scale features are particularly useful to identify the causes of cervical lymphadenopathy. (j bagh coll dentistry 2018; 30(3): 59-67) introduction: cervical lymphadenopathy (lap) is a common presenting sign and symptom for various array of diseases, ranging from mild infections to life threatening head and neck malignancies[1]. the clinical examination alone cannot be considered as a diagnostic tool to determine the involvement of cervical lymph nodes especially deep or small nodes. many diseases involve lymph nodes, so that detection of lymph node has great therapeutic and prognostic implications. it is in this context that imaging modalities such as magnetic resonance imaging (mri), computed tomography (ct) scan and ultrasonogram have an important role in examination of clinically undetectable lymph nodes. though ct scan and mri are very helpful in detection of cervical lymph node pathology, ultrasound, particularly by using high resolution probes (7.5 to 15 mhz) has always been considered as a powerful tool for assessment of head and neck lymphadenopathy[2]. although mri and ct scan are useful diagnostic aids, both are expensive and not universally available. moreover ct scan exposes the patient to relatively high dose of radiation, and mri is expensive, time consuming and not suitable for each patient[3] .cervical lymph nodes are involved by a number of pathologic processes. they are common sites for lymphoma, metastasis, and reactive enlargement in different diseases including tuberculosis (tb)[4] .therefore, evaluation of lymph nodes is of very important in order to differentiate between these conditions, selection of treatment modalities, and assessment of prognosis. materials and methods the present study was carried out over a period of 6 months and included 81 patients of different age (2) professor, college of dentistry, university of baghdad, baghdad, iraq (3) consultant radiologist, teaching hospital, medicine city of baghdad (1) ministry of health, baghdad, iraq j bagh college dentistry vol. 30(3), september 2018 evaluation of 60 groups in al-sadder teaching hospital, al-najaf, iraq; with a clinical diagnosis of cervical lymphadenopathy(lap). a detailed clinical assessment was done, and informed consent was obtained. sonographic examination was done by sonologists using (ge wipro proseries), fna, and a biopsy of the l.ns was taken from all the patients. first, ultrasonography was done, and then the patients were sent for fna and a biopsy. ultrasound machine was with multi-frequency (57 mhz) linear phased-array transducers. the scanning was performed with the patient in the supine position, with the neck of the patient hyperextended with a pad or pillow under the shoulders to provide optimum exposure of the neck .the parameters which were considered in this study and their definition are as follows: 1. site: lymph nodes were classified according to the cervical nodal chain into different groups (submental, submandibular, parotid, upper cervical, middle cervical, lower cervical, supraclavicular, posterior triangle) 2. long axis (l): the largest dimension of the lymph node. 3. short axis (s): the greatest dimension perpendicular to l. 4. shape index (s/l): the ratio of s and l. the nodes were divided into 2 groups as s/l <0.5 (oval) and s/l >0.5 (round) 5. echotexture: lymph nodes were divided as hypoechoic, isoechoic, or hyperechoic. 6. margins: based on the margins, lymph nodes were divided into 2 groups, those with welldefined/ sharp margins and those with illdefined/unsharp margins. 7. ancillary features: presence or absence of calcification, intranodal necrosis, and matting and status of the surrounding tissue as normal or abnormal. based on all these features, cervical lymphadenopathies were classified as benign/reactive and malignant/lymphomatous/metastatic. fna was performed in 23 patients, and biopsies were performed in 58 patients. the ultrasound-guided findings could be correlated with those of fna and the biopsy findings. the results were subjected to statistical analysis using spss software. a pvalue of <0.5 was considered to be significant. results all the patients presented with cervical swelling were either unilateral or bilateral with different duration ranging from (1-12) months. some of them had night sweating, fever, pain and loss of appetite. forty patients from (81) were clinically suspected to have malignant cervical lymphadenopathy, whereas, the remaining (41) patients were suspected to have benign cervical lymphadenopathy. comparison between clinical findings and histopathological results eighty one (81) subjects underwent histopathological examination; 23 fna and 58 true cut or excisional biopsy of the l.ns. the results of histopathological examination showed that, the diagnosis of forty patient out of (81) patients with cervical lymphadenopathy was malignant (11 were of non-hodgkin lymphoma, 17 of hodgkin disease and 12 were metastatic), one of the metastatic nodes were from papillary carcinoma of the thyroid. the diagnosis of the other (41) patients with cervical lymphadenopathy was benign were of reactive lymphadenitis, only one node was with tuberculosis lymphadenitis. 1age: the age of patients ranged from 5 to 75 years. there were significant difference in age , the mean age of patients with malignant lymph node was (44.17±2.65) years, while that for patients with benign lymph node was (22.21±1.92) years. patients with malignant l.ns were high significantly older (p<0.001) than patients with benign cervical l.ns (table 1). table (1): comparison of age of patients with malignant and benign lymphadenopathy 2-gender distribution: this study showed that the number and percentage of male patients with malignant lymph nodes was 23(57.5%), while female patients were 17(42.5%). in patients with benign lymph nodes the number and percentage of male patients were 22(53.7%) and 19(46.3%) were females as shown in table (2). although, it was higher in male, but it doesn’t reach the significant level (p>0.05) (table 2). parameter histopathology pvalue malignant benign mean±se mean±se age/years 44.17±2.65 22.21±1.92 <0.001 j bagh college dentistry vol. 30(3), september 2018 evaluation of 61 table (2): the number and percentage of male and female patients according to histopathology histopathology total p value malignant benign gender f 17 19 36 0.728 42.5% 46.3% 44.4% m 23 22 45 57.5% 53.7% 55.6% total 40 41 81 100.0% 100.0% 100.0% 3-family history: statistical analysis showed significant association between family history and development of malignant lesions (table 3). table (3):association between family history and histopathological findings. histopathology total pvalue malignant benign family history no 33 41 74 0.005 82.5% 100.0% 91.4% yes 7 0 7 17.5% 0.0% 8.6% total 40 41 81 100.0% 100.0% 100.0% 4-consistency of l.ns: in 81 patients, (13) hard l.ns were malignant and (1) was benign, (27) rubbery l.ns were malignant and 40 soft l.ns were benign. there is significant association between consistency of the l.ns and malignancy, where all malignant lesions either hard or rubbery, while benign lesions were soft. there was a statistically significant difference between the consistency of lymph nodes and histopathological findings (p < 0.001) (table 4). table (4): association between consistency of l.ns and histopathological findings histopathology total p value malignant benign consistency hard 13 1 14 <0.001 32.5% 2.4% 17.3% rubbery 27 0 27 67.5% 0.0% 33.3% soft 0 40 40 0.0% 97.6% 49.4% total 40 41 81 100.0% 100.0% 100.0% 5-fixation to underlying structure: forty one l.ns were fixed, (40) were malignant and (1) was benign. forty l.ns were not fixed, on histopathological evaluation all were benign. there was a statistically significant difference between fixation of the lymph nodes and histopathological findings (p < 0.001) (table 5). j bagh college dentistry vol. 30(3), september 2018 evaluation of 62 table (5): association between fixation of l.ns and histopathological findings. histopathology total p value malignant benign fixation no 0 40 40 <0.001 0.0% 97.6% 49.4% yes 40 1 41 100.0% 2.4% 50.6% total 40 41 81 100.0% 100.0% 100.0% 6-site: there was significant association between site of lymphadenopathy and malignancy, where most of malignant l.ns were either in supraclavicular area or in posterior triangle, while benign l.ns seen mostly in upper cervical region. a statistically significant difference in the distribution of lymph nodes was found. p value was 0.002 (table 6). table (6): ssociation between histopathological findings and site of l.n. comparison between ultrasonographic examination and histopathological results: all the 81 subjects examined by ultrasound and color doppler criteria were evaluated to reveal that only 41 subjects were with benign l.ns and 40 were with malignant. the validity of each sonographic criteria in the diagnosis of cervical lymphadenopathy. 1-size of the l.ns : all the patients showed an enlargement of the involved l.ns both in short and long axis. the enlarged l.ns can be detected and measured by us. the mean of short axis diameters of malignant and benign nodes in centimeters were (1.86 ± 0.08cm) and (0.83 ± 0.05cm), respectively, and the mean of long axis diameters of malignant nodes and benign nodes were (2.47 ± 0.11 cm ) and (2.01 ± 0.11cm) respectively. it was found that the malignant nodes were significantly greater in short axis and long diameter than benign lymph nodes. there was a statistically significant difference between the mean values of the short axis (p < 0.001) and statistically significant difference between the long axis (p < 0.005) among the benign and malignant cervical lymph nodes (table 7). histopathology total p value malignant benign site submental 0 7 7 0.002 0.0% 17.1% 8.6% submandibular 8 8 16 20.0% 19.5% 19.8% parotid 0 4 4 0.0% 9.8% 4.9% upper cervical 8 9 17 20.0% 22.0% 21.0% middle cervical 2 5 7 5.0% 12.2% 8.6% lower cervical 2 0 2 5.0% 0.0% 2.5% supra clavicular 11 1 12 27.5% 2.4% 14.8% posterior triangle 9 7 16 22.5% 17.1% 19.8% total 40 41 81 100.0% 100.0% 100.0% j bagh college dentistry vol. 30(3), september 2018 evaluation of 63 table (7) : size of the involved l.ns measured by us 2shape of the l.ns : the shape of l.ns was detected by calculating the s/l ratio when the ratio is > 0.5 l.ns considered round (figure 1), (38 of 81) subjects showed round shape representing (46.9%), when the ratio is<0.5 l.ns consider oval (figure 2),(43 of 81) subjects showed oval shape representing (53.1%) the results revealed that 38 patients with malignant l.ns presents as round in us, while only 2 cases were oval. in benign all l.ns appear in us as oval in shape. so the shape may give a specific feature in cervical lap, the difference in shape was statistically significant with (p < 0.001) (table 8). table (8):association between shape of l.ns and histopathological findings histopathology total p value malignant benign s/l ratio 0.76±0.02 0.42±0.02 <0.001 shape oval 2 41 43 <0.001 5.0% 100.0% 53.1% round 38 0 38 95.0% 0.0% 46.9% total 40 41 81 100.0% 100.0% 100.0% figure (1):-gray scale ultrasound image of figure (2):-gray scale ultrasound image round-shaped malignant lymph node of oval-shaped reactive lymph node 3the number of l.ns: in this study the number of lymph nodes was classify to solitary (1-5) nodes, and diffuse (5-10) and the largest node was measured. solitary nodes seen in (38 malignant and 39 benign), while diffuse nodes seen in (2 malignant and 2 benign). statistical analysis showed that no significant differences between number of benign and malignant lymph nodes (p >0.05) (table 9). parameter malignant (n=40) benign (n=41) p value mean±se mean±se size cm2 2.15±0.098 1.44±0.099 <0.001 s. axis 1.86±0.08 0.83±0.05 <0.001 l. axis 2.47±0.11 2.01±0.11 0.005 j bagh college dentistry vol. 30(3), september 2018 evaluation of 64 table (9) :-association between number of l.ns and histopathological findings. histopathology total p value malignant benign no. of l.ns diffuse 2 2 4 0.980 5.0% 4.9% 4.9% solitary 38 39 77 95.0% 95.1% 95.1% total 40 41 81 100.0% 100.0% 100.0% 4echogenecity of the l.ns: all the involved l.ns in all patients were hypoechoic this make this feature to be nonspecific but sensitive, except for metastatic l.n from papillary carcinoma of thyroid were hyperechoic. 5the borders of l.ns : assessment of border in the study groups showed that 30 of malignant nodes had sharp border (figure 3), while 10 had unsharp borders. in benign l.n, 4 had sharp border, while, 37 of nodes had unsharp borders (figure 4).statistical analysis showed that it is statistical significant there is significant association between malignancy and sharp boeders (p<0.001) as shown in (table 10). table (10):association between histopathological findings and borders of l.ns histopathology total p value malignant benign margins unsharp 10 37 47 <0.001 25.0% 90.2% 58.0% sharp 30 4 34 75.0% 9.8% 42.0% total 40 41 81 100.0% 100.0% 100.0% figure(3):-lymph nodes with sharp borders. figure (4):-lymph nodes with unsharp borders. 6hilum of l.ns: hilum was present in 34 of 81 nodes whereas it was absent in 47 lymph nodes. of these 34 nodes with hilum presence, 33 nodes were histopathologically proven as benign nodes and 1 node was malignant. it has been observed that the presence of echogenic hilum within an enlarged lymph node can be considered a sign of its benign nature. of 47 nodes with absent hilum, 39 were histopathologically proven as malignant whereas 8 as benign nodes. the criterion was statistically significant with p < 0.0001(table 11). j bagh college dentistry vol. 30(3), september 2018 evaluation of 65 table (11):association between histopathological findings and hilum of l.n histopathology total p value malignant benign hilum no 39 8 47 <0.001 97.5% 19.5% 58.0% yes 1 33 34 2.5% 80.5% 42.0% total 40 41 81 100.0% 100.0% 100.0% 7ancillary features: assessment of calcification of lymph nodes showed that calcification was present in only one patient with metastatic lymph node from papillary carcinoma of thyroid. matting of lymph nodes was also shown in only one malignant l.ns . necrosis of lymph nodes was shown in 6 malignant and 8 benign lymph nodes. statistical analysis showed no significant differences. the p value was 0.23 (p > 0.05), which proves that it is statistical not significant (table12). table (12):association between ancillary features and histopathological findings histopathology total p value malignant benign ancillary features calcification 1 0 1 0.237 2.5% 0.0% 1.2% matting 1 0 1 2.5% 0.0% 1.2% necrosis& matting 3 0 3 7.5% 0.0% 3.7% necrosis 6 8 14 15.0% 19.5% 17.3% no necrosis& matting 29 33 62 72.5% 80.5% 76.5% total 40 41 81 100.0% 100.0% 100.0% discussion age and gender: this study showed that the age range of patients with cervical lymphadenopathy was 5 to 75 years. there was a significant difference in age, the mean age of patients with malignant lymph node was (44.17±2.65 years), while that for patients with benign lymph node was (22.21±1.92years). patients with malignant l.ns were significantly older than patients with benign cervical l.ns. this study is agree with richner and laifer,[5] and jayaraman et al. [6] .this study showed that the number of male patients with cervical lymphadenopathy were higher than the number of female patients and this agree with the study [7]. consistency: this study showed that there is significant association between consistency of l.ns and malignancy, where all malignant lesions either hard or rubbery, while benign lesions were soft. the results similar to bazemore and smuck,[8]. fixation to underlying structure: this study showed statistical difference between fixation of the malignant and benign lymph nodes. forty one l.ns were fixed, (40 were malignant and 1 was benign). forty l.ns were not fixed, all were benign, and approximately all benign l.ns were not fixed. which was agree with, leung and davies[9]. sit: in this study, there was significant association between site of lymph node and malignancy, where most of malignant lesions either supraclavicular or posterior triangle, while benign lesions seen mostly in upper cervical j bagh college dentistry vol. 30(3), september 2018 evaluation of 66 region. this study is agree with mohseni et al.[10]. size: this study showed statistically significant difference between mean values of short axis diameter and long axis diameter of the malignant and benign nodes. malignant nodes showed greater short axis diameter and long axis diameter than the benign nodes and similar observations were made by misra et al. [11] lymph nodes more than 10mm in the longest axial diameter are said to be enlarged. the upper limit in minimal axial diameter of normal node is 9mm for submandibular and upper cervical nodes and 8mm for other cervical nodes [12]. shape of l.ns: this study showed statistically significant difference between the shape of malignant and benign l.ns .the shape of l.ns was detected by calculating the s/l ratio when the ratio is > 0.5 l.ns considered round, 38 of 81 subjects showed round shape representing (46.9%), when the ratio is<0.5 l.ns consider oval, 43 of 81 subjects showed oval shape representing (53.1%). malignant nodes tend to be round due to rapid growth whereas benign nodes tend to be oval in shape[13]. this fact was clearly proven in this study. the mean s/l ratio for benign nodes was 0.42 ± 0.02cm and for malignant nodes it was 0.76± 0.02cm. this study is agree with lyshchik et al.[14]. borders of l.ns: assessment of border in this study groups showed that (30 nodes) of malignant nodes had sharp borders and (10) had unsharp borders. however, only (37 nodes) of benign nodes had unsharp border, while (4 nodes) had sharp border. the sensitivity were 75% of malignant l.ns with well-defined borders.this study agree with[15]. hilum: in this study, echogenic hilus was present in (33 nodes) of benign nodes and (one nodes) of malignant group. loss of echogenic hilus was noted in (39 nodes) of malignant nodes. the sensitivity was 97.5% and the specificity was 80.5%, these results were similar to leboullexe et al. [16]. echogenicity: in this study, all the involved l.ns in all patients were hypoechoic this make this feature to be nonspecific but sensitive, except for metastatic l.ns from papillary carcinoma of thyroid were hyperechoic. in a study done by mahazer et al. [17] showed that presence of internal echoes was highly specific for malignancy. this study is also agree with khanna et al. [18] study that showed most of lymph nodes were hypoechoic. ancillary feature: in this study, necrosis was found in 8 benign l.ns and in 6 malignant l.ns. presence of intranodal necrosis is pathological. cystic necrosis which appears as intranodal echolucent area can occur in metastatic nodes from squamous cell carcinoma, papillary carcinoma of thyroid as well as in tuberculosis [19]. so necrosis alone cannot be used as a criterion for diagnosing malignancy. in this study one tuberculosis patient had matting, while 4 patients with malignancy had matting. it was statistically not significant. matting of l.ns is due to inflammation and edema of perinodal soft tissue which is a common feature of tuberculosis and other bacterial infection[20-21]. conclusions sonographic findings have a high accuracy in differentiating benign from malignant cervical lymph nodes. an ultrasound scan can be used as the first-line imaging tool in the diagnostic evaluation of cervical lymphadenopathy. using gray scale features are particularly useful to identify the causes of cervical lymphadenopathy. references: 1. russell rcg, norman s, christopher,(2004) ‘bailey & love’s short practice of surgery’, 24th edition, hodder arnold, london, pp. 936-938. 2. mahazer h, sharifkashani sh, sharifian h, ( 2004) ‘triplex ultrasonographic assessment of cervical lymph nodes’, actamedicairanica,. 42, ( 6), pp. 441-444, jun.. 3. esengul, (2006 ) ‘ultrasound of superficial lymph nodes’, european journal of radiology, 58, pp. 345-349,. 4. baatenburg de jong rj, rongen rj, verwoerd cd, van overhagen h, lame´ris js, knegt p.(1991) ultrasound-guided fine-needle aspiration biopsy of neck nodes. arch otolaryngol head neck surg ;117:402–404. 5. richner s, laifer g.(2010) peripheral lymphadenopathy in immunocompetent adults. swiss med wkly. 140:98-104. pubmed pmid: 20069473 6. jayaraman v., austin r. d.and ramasamy r. (2013). the efficacy of colour doppler ultrasound in differentiating malignant and nonmalignant head and neck lymph node enlargement. international journal of dental science and research, 1, 8-15. 7. gupta, a., rahman, k., shahid, m., kumar, a., qaseem, s. d., hassan, s. a., & siddiqui, f. a. (2011). sonographic assessment of cervical lymphadenopathy: role of high resolution and color doppler imaging. head & neck, 33(3), 297302. 8. bazemore a. w.and smucker d. r. (2002). lymphadenopathy and malignancy. american family physician, 66, 2103-10. 9. leung a. k.and davies h. d. (2009). cervical lymphadenitis: etiology, diagnosis, and management. current infectious disease reports, 11, 183-89. 10. mohseni s., shojaiefard a., khorgami z., alinejad s., ghorbani a.and ghafouri a. (2014). peripheral j bagh college dentistry vol. 30(3), september 2018 evaluation of 67 lymphadenopathy: approach and diagnostic tools. iranian journal of medical sciences, 39, 158. 11. misra d., panjwani s., rai s., misra a., prabhat m., gupta p.and talukder s. k. (2016). diagnostic efficacy of color doppler ultrasound in evaluation of cervical lymphadenopathy. dental research journal, 13, 217. 12. nishith, s. (2013). role of sonography and colour doppler in evaluation of cervical lymphadenopathy (doctoral dissertation). 13. kuna s. k., bracic i., tesic v., kuna k., herceg g. h.and dodig d. (2006). ultrasonographic differentiation of benign from malignant neck lymphadenopathy in thyroid cancer. journal of ultrasound in medicine, 25, 1531-37. 14. lyshchik a., higashi t., asato r., tanaka s., ito j., hiraoka m., insana m. f., brill a. b., saga t.and togashi k. (2007). cervical lymph node metastases: diagnosis at sonoelastography—initial experience. radiology, 243, 258-67. 15. head, n. (2013). the efficacy of colour doppler ultrasound in differentiating malignant and nonmalignant head and neck lymph node enlargement. international journal, 1(1), 8-15. 16. leboulleux s., girard e., rose m., travagli j. p., sabbah n., caillou b., hartl d. m., lassau n., baudin e.and schlumberger m. (2007). ultrasound criteria of malignancy for cervical lymph nodes in patients followed up for differentiated thyroid cancer. the journal of clinical endocrinology & metabolism, 92, 3590-94. 17. mazaher h.and sharifian s. s. h. (2004). triplex ultrasonographic assessment of cervical lymph nodes. acta medica iranica, 42, 441-44. 18. khanna r., sharma a. d., khanna s., kumar m.and shukla r. c. (2011). usefulness of ultrasonography for the evaluation of cervical lymphadenopathy. world journal of surgical oncology, 9, 29. 19. ahuja a., ying m., king w.and metreweli c. (1997). a practical approach to ultrasound of cervical lymph nodes. the journal of laryngology & otology, 111, 245-56. 20. ahuja a., ying m., yuen y. h.and metreweli c. (2001b). power doppler sonography to differentiate tuberculous cervical lymphadenopathy from nasopharyngeal carcinoma. american journal of neuroradiology, 22, 735-40. 21. ying m., lee y., wong k., leung v.and ahuja a. (2009). personal practice ultrasonography of neck lymph nodes in children. hk j paediatr (new series), 14, 29-36. الخالصة وتتضخم نتيجة تأثير بعدد الخلفية: العقد اللمفية العنقية عرضة للتدخل من خالل عدد من االمراض. وهي مواقع شائعة لورم الغدد اللمفاوية ، واالورام الخبيثة ، .من الحاالت االخرى السونار التقييم السريري للمرضى الذين يعانون من تضخم العقد اللمفية العنقية، التفريق بين الغدد الليمفاوية الحميدة والخبيثة بواسطة جهاز -الدراسة: أهداف وربط نتائجه بالنتائج الخلوية و / أو النسيجية للغدد الليمفاوية العنقية مريضا من مختلف الفئات العمرية الذين يعانون من اعتالل العقد 18أشهر وشملت 6ة الحالية على مدى أجريت الدراس -االشخاص ،المواد وطرق العمل: تم إجراء . الصوتيةاللمفية العنقية. تم فحص كل مريض سريريًا ، ثم تم إجراء فحص تصويري شامل للرقبة للعقد اللمفية العنقية باستخدام جهاز الموجات فوق االستلقاء ، مع اظهار الرقبة باستخدام وسادة تحت الكتفين من أجل التعرض األمثل للرقبة. تتضمن المعلومات الواردة في هذه الفحص والمريض في وضع لمحيطة بالنسيج.الدراسة: الموقع ، المحور الطويل، المحور القصير، مؤشر الشكل, الحدود ، المالمح المساعدة مثل التكلس ، النخر ، التجمع والتغيرات ا ارتبطت هذه النتائج مع النتائج الخلوية و الخزعة األساسية . تم تصنيف العقد على أنها حميدة )تفاعلية( وخبيثة. أنثى ، وكان هناك ارتباط بين تاريخ العائلة وتطور اآلفات الخبيثة. فيما 66ذكرا و 54تراوح عمر المرضى بين خمس وخمس وسبعين سنة ، وكانوا -النتائج: المتبقية لينة كانت حميدة. وفقا 54من الغدد المطاطية كانت خبيثة و 72( حميدا ، 8صلب خبيثا و )منها 86بالتقييم السريري ، ووفقا لالتساق ، كان يتعلق ثابتة اظهر تقييم األنسجة المرضية انها ( كانت حميدة. االربعين المتبقية لم تكن 8كانت خبيثة و ) عقدة من الملتصقات 54للثبات وااللتصاق مع االنسجة التحتية ، المحور الصغير متجانسة ، وشكل العقدة )نسبة كانت حميدة, فحص السونار أظهر النتائج أن الغدد الليمفاوية الخبيثة تظهر في الغالب على شكل دائري ، و العقد الخبيثة لها حدود واضحة المعالم. تم العثور على تكلسات ، نخر ، حصيرة دقيق للتمييز بين الحميدة من الغدد الليمفاوية وبين الخبيثة. معظمللمحور الكبير( يتمتع بدقة عالية مقارنة بالعينات التي ، مميزة في العقدة الليمفاوية الحميدة. كان التشخيص الشامل بواسطة سحب العينات الخلوية تحت الموجات فوق الصوتية .سحبت وحدها وتية كأداة السونار لديها دقة عالية في التمييز بين الغدد اللمفية الحميدة من العقد الليمفاوية الخبيثة. يمكن استخدام الفحص بالموجات فوق الصنتائج -االستنتاجات: تصوير في الخط األول في التقييم التشخيصي لمرضي العقد اللمفية العنقية. j bagh college dentistry vol. 30(3), september 2018 assessment of 28 assessment of dental caries among internally displaced children in baghdad athraa m. alwaheb b.d.s., m.sc. (1) akram f. alhuwaizi b.d.s., m.sc., ph.d. (1) abstract background: the internally displaced children are vulnerable groups have less access to dental services, worse oral health, and bear a disproportionate burden of oral diseases. aim of the study: this study was conducted on group of internally displaced children living in baghdad governorate camps to measure their dental caries prevalence and experience and find out the association between dental caries and the duration of displacement in camps. subjects and methods: a sample of 1393 children were selected, 567 internally displaced children from camps in baghdad governorate and 826 school children as control matching in age and gender. the age of children ranged from 5-12 years old. oral examination was performed using who 2013 criteria, to measure dental caries using cpi probe. results: there were a significant difference of dmfs and dmft between internally displaced children and schoolchildren. caries free internally displaced children were 39.2% and 30% among school children. there was no statistically significant correlation between camp duration and dental caries experience in deciduous teeth while a significant relation was found in permanent teeth. conclusion: this study revealed an increase in dental caries experience with increase in duration of displacement. hence this survey highlighted the need of internally displaced children to dental health education programs and preventive measures and give information for monitoring the caries which is helpful for policy makers. key words: internally displaced children, dental caries, cpi. (j bagh coll dentistry 2018; 30(3): 28-31) introduction migration, both forced and voluntary. has long been. a major part. of iraqis’ lives. violence and wars which begun in december 2013, has displaced three million iraqis, which had precipitated a complex and urgent humanitarian situation (1,2). humanitarians estimated during 2017; a 1.1 million of displaced people were expected to be resident in emergency sites and camps (3) an estimation of 50,760 families, 304,560 internally displaced persons (idps) residing in baghdad governorate came from anbar governorate, ninewa and salahaldin and other governorates (4). internally displaced persons are considered as vulnerable groups have less access to dental services, poor oral health, and suffer from extreme burden of oral diseases (5). a study were done on syrian(6) refugee found out dental caries 1.6 ± 2.6 teeth. and internally displaced children in kosovo(7) and pakistan(8). the internally displaced children with low socioeconomical level and low parents educational level experienced poor oral hygiene and increase in dental caries(9). dental caries is a worldwide chronic disease affecting all age groups, both gender, races, and all geographic residency, causing pain, groups; caries free (0), 1-5 surfaces, 6-10 surfaces and more than 10 surfaces affected by dental local and systematic infection and progress into tooth pulp ending with dental abscess formation if (1) professor, college of dentistry, university of baghdad, baghdad, iraq untreated. also, it affects children’s general health, growth and development, nutrition and quality of life (10,11). iraq is one of the developing countries that showed an increase in caries prevalence and severity. many studies found that caries prevalence was low (12-16) while other studies showed high prevalence (17-22). this study was conducted on group of internally displaced children (idc) living in baghdad governorate camps to find out the association of dental caries with duration of displacement in comparison to schoolchildren living near camps. subjects and methods a sample of 567 internally displaced children were selected from different camps in baghdad governorate and 826 schoolchildren matching with age and gender as control aged 5-12 years old. the internally displaced children (idc) were originated from alanbar governorate salahaldin and ninewa. intra oral examination of dental caries status was recorded according to who 2013(23) using cpi probe. dental caries was measured by dmft/s for deciduous teeth and dmft/s for permanent teeth. dental caries indices: tooth (dmft, dmft) and surface levels (dmfs, dmfs). the dmfs/dmfs percentage divided into four groups; caries free (0), 1-5 surfaces, 6-10 surfaces and more than 10 surfaces affected by dental caries. the duration of displacement was divided into 3 j bagh college dentistry vol. 30(3), september 2018 assessment of 29 groups 1-12, 13-24, more than 24 months. the data were grouped by statistical quartile. the statistical data analysis was approached by using statistical package (spss) ver. (23.0) in order to analyze and assess the results of this study through application of descriptive data analysis, by frequencies, and percentages. inferential data analysis, these types of analysis were used to test hypotheses by accept or reject it, which included the following; contingency coefficients (c.c.) test: estimating of the association table for finding cause's relationshiptest and spearman rank correlation test. results: the children age range from 5-12 years with mean age of 8.70±sd 2.01 for idc and 8.72± sd1.95 with 278 (49%) boys idc and sc=404 (48.9), girls 289 (51%) idc and 422(51.1%)sc. the percentage of children who spend two years in camps was 81.1%, and 18.9% spent more than two years. prevalence of children with caries free deciduous teeth were 39.2% among idc and 30% among school children. number and percentage of decayed surfaces were higher in idc than sc. missing surfaces (ms) which means extracted teeth due to caries; and filled teeth are higher among sc than idc. there were highly significant association in caries prevalence between idc and sc as shown in table 1 with comparison significant (c.s.). table 2 demonstrates caries prevalence in permanent dentition, children with caries free permanent teeth were 74.8% among idc and 77.4% among school children. all the components of dmfs showed no significant differences between idc and school children. the percentage of children having 1-5 teeth affected with caries in idc (22.6%) are more than that of school children (18.9%). idc had significantly lower caries experience in the deciduous dentition (dmfs =6.16±0.32 and dmft=2.71±0.12) than school children (dmfs= 8.06±0.28 and dmft=3.22±0.10). however, in the permanent dentition caries experience showed no statistically significant differences between idc (dmfs =0.86±0.07 and =0.60±0.05) and school children (dmfs=0.94±0.08 and dmft= 0.64±0.04) (table 3). no statistically significant differences between idc (dmfs=0.86±0.07 and dmft=0.60±0.05) and school children (dmfs =0.94±0.08 and dmft=0.64±0.04) (table 3). the caries severity (dmfs) for girls and boys showed no significant association for both idc and school children (table 4). table 5 shows that there was no statically significant correlation between camp duration and caries experience dmfs and its components (table 5). while for permanent teeth there was a significant difference between the groups with caries experience increasing with camp duration (f=4.957, df=2, p=0.007) as shown in figure 1. table 1: distribution of the children according to dmfs and its components. dental caries idc sc c.s. (*) p-value no. % no. % ds 300 52.9 578 31.4 ms 41 7.2 142 17.2 fs 4 0.7 15 1.8 dmfs 0 222 39.1 248 30.0 c.c.=0.119 p=0.000 (hs) 1 – 5 137 24.2 189 22.9 6 – 10 101 17.8 158 19.1 > 10 107 18.9 231 28.0 total 567 100 826 100 hs: highly significant at p<0.01; based on a contingency coefficient (c.c.) tests table 2: distribution of the children according to dmfs and its components. dental caries idc sc c.s. (*) p-value no. % no. % ds 132 23.2 159 19.2 ms 5 0.9 15 1.7 fs 6 1.1 13 1.6 dmfs 0 424 74.8 639 77.4 c.c.=0.054 p=0.259 (ns) 1 – 5 128 22.6 156 18.9 6 – 10 13 2.3 25 3 > 10 2 0.3 6 0.7 total 567 100 826 100 ns=not significant p>0.05; based on a contingency coefficient (c.c.) tests. table 3: the mean and the standard error of dental caries experience of the children. variable sample mean std. error t c.s. (*) p-value dmfs idc 6.16 0.32 4.326 p=0.000 hs* sc 8.06 0.28 dmft idc 2.71 0.12 3.180 p=0.002 hs* sc 3.22 0.10 dmfs idc 0.86 0.07 0.602 p=0.548 ns sc 0.94 0.08 dmft idc 0.60 0.05 0.578 p=0.564 ns sc 0.64 0.04 *hs: highly sig. at p<0.01; ns: not sig.at p>0.05, based on t-test. j bagh college dentistry vol. 30(3), september 2018 assessment of 30 table 4: caries severity dmfs of children distributed according to gender. dmfs gender total c.s. (*) p-value boys girls n % n % n % idc 0 106 38.1 116 41.1 222 39.1 cc=0.081 p=0.293 ns 1–5 60 21.6 77 25.7 137 24.2 6–10 53 19.1 48 16.1 101 17.8 >10 59 21.2 48 16.1 107 18.9 total 278 100 289 100 567 100 sc 0 99 24.5 149 35.3 248 30.0 cc=0.196 p=0. 862 s 1–5 98 24.3 91 21.6 189 22.9 6–10 81 20.0 77 18.2 158 19.1 >10 126 31.2 105 24.9 231 28.0 total 404 100.0 422 100.0 826 100.0 s= sig. at p<0.05; ns: not sig.at p>0.05 based on a contingency coefficient (c.c.) tests. table 5: mean and standard error and the correlation of dental caries in deciduous teeth of internally displaced children according to duration of living in camps. displacement duration (months) n mean se c.s. (*) p-value ds 1 – 12 229 2.64 0.33 r=-0.082 p=0.051 13 -24 231 2.71 0.37 25+ 107 2.05 0.44 ms 1 – 12 229 0.63 0.14 r=-0.065 p=0.121 13 -24 231 0.54 0.15 25+ 107 0.37 0.18 fs 1 – 12 229 0.01 0.00 r=0.002 p=0.963 13 – 24 231 0.04 0.02 25+ 107 0.00 0.00 dmfs 1 – 12 229 5.46 0.44 r=-0.051 p=0.222 13 -24 231 5.94 0.49 25+ 107 4.30 0.61 ns: non sig. at p>0.05; testing based on spearman rank correlation test. figure 1: mean dental caries in permanent teeth of internally displaced children according to duration of living in camps. discussion the caries free idc was 93% of children which more than sc 30% and more than study done in jordan(24) and more than idc in kosovo (6).the dmft of idc was found to 2.7 ± 0.12 and which considered moderate according to who 2013(20) (moderate 2.7– 4.4) and less than school children dmft 3.23 ±0.10 and lower than (25),.the dmft of idc 0.60 ±0.05 which is very low in a accordance to who 2013 (very low <1.2),also lower than other studies done on idc in iran, kosovo and pakistan and syrian refugee teeth (6,7,9,26). this low caries experience is may be due to their displacement situation which made them far from cariogenic food like sweet candies and sugary drinks in addition to low socioeconomic in area of origin; most of children who lived in camps came from periurban areas(28) in this study girls had higher prevalence than boys but with no significant differences which is in disagree with previous studies (16,29) and agreement with others(13,14,17,30,31),this can be explained by earlier eruption of teeth in girls, hence longer exposure of girls' teeth to the cariogenic oral environment in addition to easier access to food supplies by women and frequent snacking during food preparation (31). the duration of living in camps had no significant association with dmfs and all its component, also mean dmfs increase with increasing duration (statistically significant p<0.05). this survey highlighted the need of internally displaced children to dental health education programs and preventive measures and give information for monitoring the caries trend which is helpful for policy makers. references 1zetter r. protection in crisis, forced migration and protection in a global era. washington dc: migration policy institute, 2015. 2higel l. iraq’s displacement crisis: security and protection ceasefire report centre for civilian rights and minority rights group international, 2016. 3unocha.org/iraq. needs humanitarian overview. jan, 2017. 4 iom. integrated location assessment partii. international organization for migration. iom-iraq mission. dtm-iraq mission, 2017. 5gilani i, tanwir f, afridi s. oral health assessment and barriers to seek care in internally displaced persons from bajaur agency, pakistan pakis oral dent j. 2012; 32(1):115-9. 6begzati a, meqa k, siegenthaler d, berisha m, mautsch w. dental health evaluation of children in kosovo. eur j dent. 2011, 5(1): 32–9. 7nazir r, hussain a, kaleem m. oral health status and malocclusion in flood affected and internally displaced children in pakistan, planning and future scenarios. pakis oral dent j. 2012; 32(1):110-4. 0.63 0.79 1 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1_12 13-24 25+ m e a n d m f s camp duration j bagh college dentistry vol. 30(3), september 2018 assessment of 31 8riatto s, montero j, pe´rez d, castaño-se´iquer a, abraham dib a. oral health status of syrian children in the refugee center of melilla, spain. inter j dent 2018; 2018 (9) :1-7. 9safaverdi a. oral health in iran. a comparison between tehran and pardis. master thesis. umea international school of public health, umea university; 2009. 10fejerskov o, kidd e. dental caries, the disease and its clinical management. 2nd ed. london, blackwell munksgaard; 2008. 11li m, zhou y, qiu rm, lin hc. impact of early childhood caries on oral health-related quality of life of preschool children. eur j paediatr dent. 2015; 16: 65–72. 12diab b. nutritional status in relation to oral health condition among 6-10 years primary school children in the middle region of iraq. ph,d thesis submitted to the college of dentistry, university of baghdad; 2003. 13khamarco t, mitres a. the effect of residential factor on dental caries prevalence and treatment needs among the primary school children in ninevah governorate/iraq. mustansiria dent j 2004; 1(1): 2138. 14ahmed na, astrøm an, skaug n, petersen pe. dental caries prevalence and risk factors among 12year old schoolchildren from baghdad, iraq: a postwar survey. inter dent j 2007; 57(1): 36–44. 15mohammed g. oral health status and treatment needs among 13-15 year-old students in sulaimani city. master thesis submitted to college of dentistry, suleimani university; 2008. 16abdul razzaq q. oral health status among 15 yearold school students in sulaimania city-iraq. master thesis submitted to college of dentistry, university of baghdad 2007. 17baram a. oral health status and treatment needs among primary school children in sulaimani city. master thesis submitted to college of dentistry, university of baghdad 2007. 18al-obaidi e. oral health status and treatment needs among 15 year old students in al-diwania governorate-iraq. master thesis submitted to college of dentistry, university of baghdad; 2008. 19al-jebouri h. oral health status among 15 years old in hilla governorate. master thesis submitted to college of dentistry, university of baghdad 2007 20al-galebi s. oral health status and treatment need in relation to nutritional status among 9-10 year-old school children in nassirya city/iraq. master thesis submitted to college of dentistry, university of baghdad;2011. 21al-sadam, n. oral health status in relation to nutritional and social status in kerbal'a governorate for primary school students aged 12 years old. master thesis submitted to the college of dentistry, university of baghdad; 2013. 22al-mujamaii kn. oral health status and dental treatment needs among intermediate school male students in al-khalis city/iraq. master thesis submitted to college of dentistry, university of baghdad 2017. 23who. world health organization. basic survey methods. 5th ed; 2013 24rajab ld, petersen pe, baqain z, bakaeen g. oral health status among 6and 12-year-old jordanian schoolchildren. oral health preven dentis 2014, 12(2): 99-107. 25slade gd, reisine st. the child oral health impact profile: current status and future directions. community dent oral epidemiol. 2017; 35(suppl 1): 50-3. 26riggs e, gibbs l, kilpatrick n, gussy m, gemert c, ali s, waters e. breaking down the barriers: a qualitative study to understand child oral health in refugee and migrant communities in australia, ethnicity health. 2014; 20(3): 241-57. 27ismael kh,yousif a, hammed. النزوح الكبير.مركز بالدي ,الطبعة االولى4للدراسات واالبحاث االستراتيجية اصدار رقم 2016 28mubarak d. oral health status and treatment need among eight years old school children in urban and rural areas in baghdad –iraq. master thesis submitted to college of dentistry, university of baghdad 2002. 29al-azawi l. oral health status and treatment needs among iraqi five-years old kindergarten children and fifteen-years old students (a national survey). ph.d. thesis submitted to college of dentistry, university of baghdad 2000. 30mcdonald re, avery da, dean ja. dentistry for child and adolescent; 8th ed. mosby: gingivitis and periodontal diseases: 2004, p. 413. 31lukacs jr, largaespada ll. explaining sex differences in dental caries prevalence: saliva, hormones, and life-history etiologies. am j hum biol. 2006;18(4):540-55. الخالصة األطفال النازحون هم من الفئات الضعيفة غير المحصنة الذين لديهم قدرة أقل على الحصول على خدمات العالجية االسنية : لخلفيةا : أجريت هذه الدراسة على مجموعة من األطفال الدراسةالهدف من صحة فموية سيئة ، ويتحملون عبئاً من االمراض الفموية النازحين داخلياً الذين يعيشون في مخيمات محافظة بغداد لقياس انتشار تسوس األسنان لديهم ومعرفة االرتباط بين تسوس األسنان لنازحين داخلياً من المخيمات في من األطفال ا 765, طفالً 3939: تم اختيار عينة من واألسصليب خشخص االومدة النزوح في المخيمات. سنة. تم 32-7في العمر والجنس. تراوحت أعمار األطفال بين متجانسة كعينة ضابطةمن أطفال المدارس 626محافظة بغداد و كان هناك النتصئج:.cpi، لقياس تسوس األسنان باستخدام مسبار 2139باستخدام معايير منظمة الصحة العالمية فمويإجراء فحص االطفال النازحين بدون تسوسداخلياً وبين تالميذ المدارس. بلغت نسبة النازحينبين األطفال dmftو dmfsبين ةق كبيروفر في األسنان التسوسالمخيم النزوح في بين أطفال المدارس.لم تكن هناك عالقة ارتباطية ذات داللة إحصائية بين مدة ٪91و 39.2٪ تسوس األسنان مع زيادة فيكشفت هذه الدراسة عن زيادة :االستنتصجاللبنية في حين تم العثور على عالقة كبيرة في األسنان الدائمة. داخلياً إلى برامج التثقيف في مجال صحة األسنان والتدابير النازحيناجة األطفال ت هذه الدراسة عن حمدة النزوح.ومن ثم أبرز ائية وإعطاء معلومات لرصد التسوس وهو أمر مفيد لصانعي السياسات.الوق https://www.ncbi.nlm.nih.gov/pubmed/?term=lukacs%20jr%5bauthor%5d&cauthor=true&cauthor_uid=16788889 https://www.ncbi.nlm.nih.gov/pubmed/?term=largaespada%20ll%5bauthor%5d&cauthor=true&cauthor_uid=16788889 https://www.ncbi.nlm.nih.gov/pubmed/16788889 https://www.ncbi.nlm.nih.gov/pubmed/16788889 ali.doc j bagh college dentistry vol. 26(4), december 2014 evaluation of the restorative dentistry 9 evaluation of the effect of sodium fluoride addition on some mechanical properties of heat cure acrylic denture base materials ali am, b.d.s., m.sc. (1) abstract background: the geriatric patients wearing removable partial dentures are increasing in proportion. at the same time, the root caries prevalence accompanied by gingival recession is increasing. a variety of vehicles can deliver fluoride into the oral cavity, including fluoride mouth-rinse, fluoride dentifrice, topical fluoride, and fluoride-releasing restorative materials, all of which effectively prevent root caries and suppress recurrent caries. this study aimed to evaluate the effect of sodium fluoride addition on some mechanical properties of heat cure acrylic denture base material. material and method: a total of 90 samples were prepared in this study, then divided into three main groups according to the type of test used (hardness, tensile and transverse strength tests). each main group was subdivided into three main subdivisions according to percentage of sodium fluoride addition to the heat cure acrylic denture base material (control no addition, 2%naf ,and 5%naf sodium fluoride groups) results: the sodium fluoride addition to acrylic denture base materials showed slight but non significant increase in transverse strength and tensile strength tests while the results showed significant and highly significant differences for 2%naf and for 5%naf shore d hardness groups respectively. conclusions: addition of 2% and 5% sodium fluoride to heat cure acrylic resin is considered advantageous as the mechanical properties of resin denture base materials in respect to hardness tensile and transverse strength were not adversely affected. key words: sodium fluoride, heat cure acrylic. (j bagh coll dentistry 2014; 26(4):9-13). الخالصة . نسبة تسوس الجذر المرافقة بفترة ركود لثوّیة في ازدیاد ایضأ, في الوقت نفسھ. نسبة المرضى المسنین الذین یرتدون اطقم أسنان متحركة في ازدیاد مستمر :خلفّیة الفلورید المضاف السطح ,معجون األسنان, بما في ذلك المضمضة الفمویة الحاویة على الفلورید, لى تجویف الفمعدة مصادر استخدمت لغرض نقل مادة الفلوراید ا تقییم تأثیر ھذه الدراسة تھدف إلى. كل من ھذه المصادر یمنع بشكل فّعال تسوس جذر االسنان ویوقف معاودة التسوس, و حشوات االسنان الباعثة للفلوراید, االسنان صودیوم فلورید على بعض الخواص المیكانیكیة والفیزیائیة الطقم االسنان المصنوعة من الراتنج االكریلي الحراريإضافة الشد و الشد ,الصالدة(بعد ذلك قسمت الى ثالثة مجامیع رئیسّیة وفقا لنوع اإلختبار المستعمل , عینة في ھذا الدراسة 90أعّدت مجموعة من : طرق ومواد ما من (ري ت كّل مجموعة رئیسّیة الى ثالث مجامیع جزئیة وفقا للنسبة المئوّیة من مادة صودیوم فلورید المضافة إلى مادة الراتنج االكریلي الحراقسم). العرضي )صودیوم فلورید بالمئة 5 و, بالمئة2, إضافة قات غیر ھامة إلختبارات الشد والشد العرضي بینما كانت الفروقات ھامة أبدت نتائج إضافة الصودیوم فلورید إلى مادة الراتنج االكریلي الحراري فرو :النتائج .بالمئة على الّتوالي 5ول بالمئة2وھاّمة جّدا الختبار الصالدة وللمجامیع الشد و الشد ,الصالدة( صودیوم فلورید إلى مادة الراتنج االكریلي الحراري اضافة مفیدة بما أّن الخواص المدروسة% 5و% 2اعتبرت إضافة من :استنتاج .لم تتأثر بشكل سلبي) العرضي introduction polymethylmethacrylate (pmma) is a derivative of acrylic acid, referred to us as acrylic resin, introduced for use in dentistry since 1930 and it became the most reliable material for denture construction (1). the geriatric patients wearing removable partial dentures were increased in proportion (2). at the same time, the root caries prevalence accompanied by gingival recession is increasing (3,4). the more likely to be affected by caries and periodontal disease are abutment teeth more than any other teeth (5). because abutment teeth anchoring removable partial dentures tend to be inadequately cleaned, preventing root caries in these teeth is crucial. fluoride is the treatment choice to prevent caries development. fluoride penetration in the enamel occurs through the replacement of relatively weak hydroxyl ions in the enamel mineral structure by more active fluor (1)assistant lecturer. department of prosthodontics, college of dentistry, university of baghdad ide ions thereby improving the chemical stability of enamel structure making it more resistant to acids (6). a variety of vehicles can deliver fluoride into the oral cavity, including fluoride mouth-rinse, fluoride dentifrice, topical fluoride, and fluoridereleasing restorative materials, all of which effectively prevent root caries and suppress recurrent caries (7-11). previous studies of resin composite containing a filler of surface pre-reacted glass-ionomer (sprg) has the valuable property of being fluoride rechargeable, have revealed some aspects of its clinical value (12-15). other study examined an experimental heat cure polymethyl methacrylate (pmma) resin containing s-prg filler in terms of both the initial fluoride release and the fluoride release after recharging with fluoride solution and concluded that increase in fluoride concentration led to more releasing of fluoride but with more deterioration of mechanical properties (16). j bagh college dentistry vol. 26(4), december 2014 evaluation of the restorative dentistry 10 the purpose of this study was to examine some mechanical properties of an experimental heat cure polymethyl methacrylate (pmma) resin containing sodium fluoride, suggesting that the development of a fluoridated denture base resin with proper mechanical properties will make a significant contribution to reduce root caries in the abutment teeth of people who wear partial dentures. materials and methods materials the materials that used in this research were summarized in table 1. table 1. some of the materials used in the study samples grouping total of 90 samples were prepared in this study, then divided into three main groups according to the type of test used (transverse test, tensile test and hardness test groups) each main group was subdivided into three main subdivisions (10 samples each) according to the percentage of sodium fluoride (naf) addition to the heat cure acrylic denture base material (controlled group (no addition), 2% naf and 5% naf sodium fluoride groups). preparation of specimens for transverse strength, tensile strength and hardness tests metal patterns were constructed by cutting the stainless steel plates with the dimensions of (65mm x 10mm x 2.5mm) length, width, thickness respectively for transverse strength test (9).while for tensile test dumble shaped metal pattern were constructed with the dimension of ( 75mm x 12.5mm x 2.5mm) length, width, thickness respectively (17) as shown in figure 1. figure 1: metal pattern for tensile strength test mould preparation the conventional flasking technique for complete dentures was followed in preparation of the mould. proportioning and mixing of the acrylic with naf white sodium fluoride powder was added to pmma powder at 2% and 5％ by weight and dispersed with a mixing machine for 15 minutes. the resin polymers containing well dispersed naf were mixed with monomer. the proportion of mixing of acrylic resin was (12gm: 6ml) p/l ratio. all materials were mixed according to the manufacturer’s instructions and as showed in table (2). table 2: percentages and amounts of polymer, monomer and sodium fluoride powder naf % amount of naf amount of polymer amount of monomer o% 0g 12g 6 ml 2% 0.240g 11.760g 6 ml 5% 0.600g 11.400g 6 ml packing and curing of heat cure resin the packing process was performed while the acrylic was in dough stage. curing was carried out by placing the clamped flask in a water bath and processed by short curing cycle 90min at 74c° then temperature was increased to the boiling point 100°c for 30 minutes. finishing, polishing and conditioning all the specimens were finished and polished by the same investigator as follows: silicon carbide grit papers starting with grade 120, 240, 320, 400 and 500 were used in sequence during finishing procedure with continuous water cooling. the accuracy of the dimensions was verified with a vernier at three locations of the specimen. polishing was accomplished by using tripoli compound with a dry rag wheel in a lathepolishing machine. water was used during polishing to avoid excessive heat, which may lead to distortion of the specimens. all the tested specimens were conditioned in distilled water at 37c° for 48 hours before they were tested (18). mechanical tests utilized to examine properties 1transverse strength test the transverse strength of specimens was measured in air by three points bending on an (micro computer controlled electronic universal material manufacturer 1 heat-cured resin for denture. powder and liquid. vertex, holland 2 sodium fluoride powder germany j bagh college dentistry vol. 26(4), december 2014 evaluation of the restorative dentistry 11 testing machine, model wdw 50 e class 1). the device was applied with a central loading plunger and two supports with polished cylindrical surface 3.2mm in diameter placed 50mm apart. the test was carried out with a constant cross head speed of 2mm/min, the load was measured by a compression load cell of maximum capacity of 50kn. the test specimens were held at each end of the two supports, and the loading plunger placed midway between the supports. the specimens were deflected until fracture occurred (19). figure 2: specimen under transverse strength test 2-surface hardness test surface hardness was determined using durometer hardness tester from type shore d, (hardness tester-th 210, time group inc. italy) which is suitable for acrylic resin material. the instrument consists of a cylinder 1.6mm in diameter that tapers into a blunt-pointed indenter 0.8mm in diameter. the indenter is attached to a digital scale that is graduated from 0 to 100 units; measurements were taken directly from the digital scale reading. ten measurements were done on different areas of each specimen (the same selected area of each specimen), and an average of ten readings was calculated (20). 3tensile strength test the specimens were tested for tensile bond strength using (micro computer controlled electronic universal testing machine, model wdw 50 e class 1) the specimens subjected to tensile load with cross head speed (2mm /min) using load cell capacity (50kn)(21). tensile strength was calculated according to the following formula:tensile bond strength= f(n)/a(mm2) (astm. specification d-638m, 1986). results mean values, standard deviation (sd), maximum (max) and minimum (min) values of the tests result are presented in tables (3, 4 and 5). one-way anova between groups of the same test and lsd test for hardness test are presented in tables (6 and 7). table 3: descriptive data of transverse strength (n/mm2) studied groups mean s.d. min. max. control 70.24 2.01 66.53 73.24 2%naf 71.14 1.58 68.49 73.45 5%naf 72.72 2.80 68.57 76.89 table 4: descriptive data of surface hardness test studied groups mean s.d. min. max. control 85.38 1.28 83.5 87.2 2%naf 86.84 1.27 85.1 89.1 5%naf 87.67 1.04 86.2 89.1 table 5: descriptive data of tensile strength test (n/mm2) studied groups mean s.d. min. max. control 42.41 2.53 38.5 46.4 2%naf 43.66 3.12 39.1 47.5 5%naf 44.93 2.75 40.2 48.7 table 6: one-way anova between groups of the same test variables groups groups' difference (d.f.= 29) f-test p-value hardness control 9.286 0.001 (hs) 2%naf 5%naf transverse strength (n/mm2) control 3.288 0.053 (ns) 2%naf 5%naf tensile strength (n/mm2) control 2.010 0.153 (ns) 2%naf 5%naf j bagh college dentistry vol. 26(4), december 2014 evaluation of the restorative dentistry 12 table 7: least significant difference (lsd) test between hardness test groups variable groups mean difference p-value hardness control 2% -1.46 0.011 (s) 5% -2.29 0.000 (hs) 2% 5% -0.83 0.134 (ns) in general, the results of the transverse strength, surface hardness and tensile strength tests for heat-cured acrylic (h.c.a.) specimens showed that control group specimens had the lowest mean values while 5%naf group specimens had the highest mean values. one-way (anova) test revealed a non significant (ns) difference (p>0.05) between the different groups of tensile and of transverse tests while one-way (anova) showed a highly significant (hs) difference (p<0.01) between the different groups of hardness test. the lsd test between hardness groups showed a significant difference between control and 2%naf groups and a highly significant difference between control and 5%naf groups while a non significant difference appeared between 2%naf and 5%naf. discussion previous study suggested that the percentage of fluoride addition to acrylic denture base resin preferred to be less than 10% to maintain proper mechanical properties of acrylic resin (16), thus the experimental denture base resins used in the present study, containing 2 and 5 wt % of naf. in the present study, the results revealed that a non significant difference between control, 2%naf and 5%naf groups for tensile and transverse test groups despite of slight increase in mean values with increase of naf % this may be due to the small amounts of naf were added to the acrylic resin which did not affect the chain arrangement of the polymer and thus did not affect the tensile and transverse strength. there might be no reaction between naf and polymer beads which should be evaluated in other studies. the results of hardness test showed that a significant and a highly significant difference between (control and 2% groups) and (control and 5%naf groups) respectively, that may be due to the increase of crystals per unit area as a result of increase in naf% in acrylic resin as naf crystals may be harder than acrylic polymer so more resistance to indenter penetration and more hardness values obtained. so addition of 2% and 5% sodium fluoride to heat cure acrylic resin is considered advantageous as the mechanical properties of resin denture base materials in respect to hardness tensile and transverse strength were not adversely affected. references 1. jasim bs, ismail ij. the effect of silanized alumina nano -fillers addition on some physical and mechanical properties of heat cured polymethyl methacrylate denture base material. j bagh coll dentistry 2014; 26(2): 18-32. 2. zitzmann nu, staehelin k, walls aw, menghini g, weiger r, zemp stutz e. changes in oral health over a 10-yr period in switzerland. eur j oral sci 2008; 116: 52-9. 3. imazato s, ikebe k, nokubi t, ebisu s, walls awg. prevalence of root caries in a selected population of older adults in japan. j oral rehab 2006; 33: 137-43. 4. mojon p, rentsch a, budtz-jørgensen e. relationship between prosthodontic status, caries, and periodontal disease in a geriatric population. int j prosthodont 1995; 8: 564-71. 5. drake cw, beck jd. the oral status of elderly dent removable partial denture wearers. j oral rehab1993; 20: 53-60. 6. al-hasnawi ki, al-obaidi wa. effect of nd-yag laser-irradiation on fluoride uptake by tooth enamel surface. j bagh coll dentistry 2014; 26(1): 154-8. 7. jensen me, kohout f. the effect of a fluoridated dentifrice on root and coronal caries in an older adult population. j am dent assoc 1988; 117: 82932. 8. ten cate jm, buijs mj, damen jjm. ph-cycling of enamel and dentin lesions in the presence of low concentrations of fluoride. eur j oral sci 1995; 103: 362-7. 9. delbem acb, carvalho lpr, morihisa rku, cury ja. effect of rinsing with water immediately after apf gel application on enamel demineralization insitu. caries res 2005; 39: 258-60. 10. heijnsbroek m, gerardu vam, buijs mj, van loveren c, ten cate jm, timmerman mf, van der weijden ga. increased salivary fluoride concentrations after post-brush fluoride rinsing not reflected in dental plaque. caries res 2006; 40: 444448. 11. han l, edward cv, li m, niwano k, neamat ab, okamoto a, honda n, iwaku m. effect of fluoride mouth rinse on fluoride releasing and recharging from aesthetic dental materials. dent mater j 2002; 21: 28595. 12. han l, edward cv, li m, niwano k, neamat ab, okamoto a, honda n, iwaku m. effect of fluoride mouth rinse on fluoride releasing and recharging from aesthetic dental materials. dent mater j 2002; 21: 28595. 13. itota t, carrick te, rusby s, al-naimi ot, yoshiyama m, mccabe jf. determination of fluoride ions released from resin-based dental materials using ion selective electrode and ion chromatograph. j dent 2004; 32: 117-22. 14. mukai y, tomiyama k, shiiya t, kamijo k, fujino f, teranaka t. formation of inhibition layers with a j bagh college dentistry vol. 26(4), december 2014 evaluation of the restorative dentistry 13 newly developed fluoride-releasing all-in-one adhesive. dent mater j 2005; 24: 172-7. 15. han l, okamoto a, fukushima m, okiji t. evaluation of a new fluoride-releasing one-step adhesive. dent mater j 2006; 25: 509-15. 16. kamijoi k, mukai y, tominaga t, iwaya i, fujino f, hirata y, teranaka t. fluoride release and recharge characteristics of denture base resins containing surface pre-reacted glass-ionomer filler. dent mater j 2009; 28(2): 227－33. 17. safi in, kahtan h, ahmed an. assessment of zirconium oxide nano-fillers incorporation and silanation on impact, tensile strength and color alteration of heat polymerized acrylic resin. j bagh coll dentistry 2012; 24(sp. issue 2): 36-42. 18. american dental association specification no.12.guide to dental materials and devices. 10th ed. chicago; 1999. p.32. 19. safi in, moudhaffar m. evaluation the effect of modified nano-fillers addition on some properties of heat cured acrylic denture base material. j bagh coll dentistry 2011; 23(3): 23-9. 20. hachim tm, abullah zs, al-ausi yt. evaluation of the effect of addition of polyester fiber on some mechanical properties of heat cure acrylic resin. j bagh coll dentistry 2013; 25(spec. issue 1): 23-9. 21. abdul-razaq rw, abdul-hadi nf, saied hm. the effect of surface treatment on tensile bond strength between soft liner and acrylic denture base and the effect of pepsi solution on this bond with and without surface treatment. j bagh coll dentistry 2011; 23(2): 17-21. j bagh college dentistry vol. 26(1), march 2014 computed tomography oral diagnosis 92 computed tomography bone density in hounsfield units at dental implant receiving sites in different regions of the jaw bone lamia h. al-nakib, b.d.s., m.sc. (1) abstract background: determination of local bone mineral density (bmd) with cortical thickness and bone height may offer a comprehensive description of the bone the surgeon will encounter when he or she actually sets the implant. quantitative computed tomography (ct) (i.e., quantitative interpretation of values derived from hounsfield units with a suitable calibration procedure) is the modality of choice to determine bmd. the aim of the present clinical study is to determine the local bone density in dental implant recipient sites using computerized tomography. material and method: the sample consisted of (72) iraqi patients whom referred to al-kharkh general hospital, spiral ct scan department for bone quality and quantity assessment after one week of dental implants insertion, the average of bone density was measured for 120 areas indifferent sectors of maxilla and mandible in hounsfield unite. results: as a mean, males show higher bone density than females, decreased with increased age significantly, mandible show significantly higher bone density than maxilla. maxilla revealed no significant difference between the three sectors, while in the mandible there was significant difference between posterior sector (613.1hu)and both anterior (821.3 hu) and premolar sectors (779.6 hu) with no significant difference between anterior and premolar sectors. conclusion: ct-scan may provide a valuable aid to predict bone quality at potential implant sites and could be used to assess the change of bone density around dental implants. key words: computed tomography, dental implants, hounsfield unit. (j bagh coll dentistry 2014; 26(1):92-97). خالصةال ( مع سماكة القشرة العظمية و ارتفاع العظم قد تقدم وصفا شامال للعظم للجراح ليحدد امكانية زراعة األسنان باالعتماد على قياس bmd: تحديد كثافة العظام ) معلومات أساسية السريرية الحالية هو تحديد كثافة العظام المحلية في بعد غرز الزرعات السنية (. إن الهدف من هذه الدراسة ctوحدة هاونسفيلد بواسطة التصوير المقطعي )بالكثافة العظمية .وحدةهاونسفيلد باستخدام التصوير المقطعيببأسبوع لمنطقة ما حول 071ل ة مريض بوحدة الهاونسفيلد باستخدام األشعة المقطعية في مستشفى الكرخ العام ، قسم االشعة المقطعي 27كثافة العظام ل : تم قياس متوسط طرق البحث . الزرعهفي مختلف مناطق الفكين العلوي والسفلي في الفك السفلي هناك فرق بين كثافة العظم تكون اكبر عند الرجال واألصغر سنا وفي الفك السفلي اكثر من لعلوي. وال توجد فروقات محسوسة بين مناطق الفك العلوي, لكنالنتائج: ألمامي والضواحك.المقطع الخلفي عن المقطعين ا .الزرعات السنية حول كثافةالعظم التغيرفي لتقييميمكن أن تستخدم المحتملة و زرع مواقع في العظام بجودة للتنبؤ قيمة توفرمساعدة قد األشعة المقطعية: الخالصة introduction computed tomography is the best method for the morphological, quantitative and qualitative assessment of the available bone on potential recipient site for implant placement (1,2). the most popular current method of bone quality assessment is that developed by lekholm and zarb, who introduced a scale of 1–4, based on both the radiographic assessment, and the sensation of resistance experienced by the surgeon when preparing the implant site (3). the grading refers to individual experience, and furthermore, it provides only a rough mean value of the entire jaw. therefore, their classification has recently been questioned due to poor objectivity and reproducibility (4,5). de oliveira et al (6) concluded that different qualities of bone can be found in any of the anatomical regions studied (anterior and posterior sites of maxilla and mandible), which confirms the importance of a site-specific bone tissue evaluation prior to implant installation. (1)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad the bone densities assessed by hu fell into the range of optimal bone densities associated with acquired primary implant stability proposed in the literature (7). the bone densities assessed by hu fell into the range of optimal bone densities associated with acquired primary implant stability proposed in the literature (7). the mean bone density in the maxilla was significantly lower than that in the mandible (p< 0.05); the mean bone densities in the 4 jaw regions decreased in the following order: anterior mandible > anterior maxilla > posterior mandible > posterior maxilla (8). previous studies that focus on the beneficial of measuring the bone density in hu showed its importance and accuracy. the trabecular structure, by means of density distribution, around the implant showed similarities to the ct images at many regions (9). ct-scan could be use to assess the cange of bone density around dental implants. bone density around dental implant was increased after placement. the increased rate of bone density could be determined by the quality of jaw bone before implant placement (10). j bagh college dentistry vol. 26(1), march 2014 computed tomography oral diagnosis 93 valiyaparambil et al (11) research showed that there was a strong correlation between cbct gray values and hu. cbct gray values increased linearly with increasing calcium hydroxyapatite or bone equivalent density material. although the bone densities varied markedly among individuals (12), more detailed assessments of bone density may be useful to enhance initial stability of implants in the posterior maxilla because the outcomes of ozan et al. study (13), indicate that bone drilling is not an effective technique for improving implant stability when lower bone density values have resulted in the greater angular deviations in the group was noticed, in whom the implants were placed after the surgical guides were removed. this deviation might have been derived from the freehand placement of the implants and the poor quality of the bone. so bone quality must be assessed well to indicate the solutions before surgical dental implant insertion like pure-phase multiporous beta-tcp that may enhance the bone density when inserted into the bone gaps around immediate dental implants (14). material and methods the sample consisted of (72) iraqi patients indicated for dental implant (males and female), age range between (20-70) years old. they were examined during a time period started from december 2012 to april 2013. . the total sample was attended to different center of implantology in baghdad subjected to clinical examination, pre-surgical panoramic radiographical evaluation. all the patients indicated for implant treatment were referred to al-kharkh general hospital, spiral ct scan department for bone quality and quantity assessment to receive dental implants by using multi-detector computed tomography after one week from dental implant insertion after checking for primary stability. average of bone density was measured in hounsfield unite around 120 fixture's receiving areas. the sites included were divided to the following sectors (10 males and 10 females for each sector): 1. upper anterior area (canine to canine area). 2. upper premolar area. 3. upper posterior area 4. lower anterior area (canine to canine area). 5. lower premolar area. 6. lower posterior area results distribution of the sample (60 male and 60 females) according to age and gender was illustrated in table (1). regarding age, the sample were divided to three groups : <35, 35-49, and 50+. the bone density measured in hounsfield unites by the aid of ct scan according to gender and age, as a mean, males show higher bone density than females (680.2 for males and 581.5 for females). bone density decreased with increased age significantly, with mean of 716.1, 623.9, 514.7 for <35, 35-49, and 50+ respectively and mandible show significantly higher bone density than maxilla (738.0 and 523.6 respectively) as shown in table (2) when bone density classified according to jaw sectors , measurements related to maxilla revealed no significant difference between the three sectors , while in the mandible there was significant difference between posterior sector (613.1hu)and both anterior (821.3 hu)and premolar sectors (779.6 hu) with no significant difference between anterior and premolar sectors as shown by table (3). according to jaw sector in relation to gender as shown in table 4, the accepted range of normal value (5th-95th percentile) was for females, as a total it was (268-947) hu for the mandible, the highest bone density for premolar sector (659987) hu then (376-892) hu for molar and (238873) hu for anterior sector. while for the maxilla it was (345-658) hu, (382-687) hu, (246-658) hu for anterior sector, premolar sector, and molar sector respectively with total (345-658) hu. for males, in the mandible the bone density was (876-1135) hu for anterior sector, premolar sector (646-876) hu, and molar sector (340-1082) hu with total (407-1135) hu. while in the maxilla (408-743) hu for the anterior sector, (436-784) hu for premolar sector, (398-657) hu for molar sector, and for total bone density was (408-779) hu. (table 4) as shown in table 5, the net and independent effect of gender, jaw type , jaw sector , and age on bone density was evaluated by a multiple linear regression model was statistically significant and able to explain 52% of observed variation in the dependent variable (bone density). being a male is expected to significantly increase in bone density by a mean of 101.6 hu compared to females (table 5), after adjusting for the remaining explanatory factors included in the model (jaw type, jaw sector, and age). upper jaw is associated with a statistically significant decrease in bone density by a mean of 208.6 hu compared to lower jaw (table 5), after http://lib.bioinfo.pl/auth:valiyaparambil,jv http://lib.bioinfo.pl/auth:ozan,o j bagh college dentistry vol. 26(1), march 2014 computed tomography oral diagnosis 94 adjusting for the remaining explanatory factors included in the model (gender, jaw sector, and age). there was no important or statistically significant difference in mean of bone density between premolar and anterior sector (table 5), while molar sector showed a statistically significant decrease in bone density by a mean of – 93.5 hu compared with anterior sector after adjusting for the remaining explanatory factors included in the model (gender, jaw type, and age). age had a statistically significant negative impact on bone density. being an older age group (35-49) is expected to decrease bone density by a mean of 85.8 hu compared to very young adults (˂35 years of age). being older age (50+ years) is expected to decrease bone density by 171.6 hu compared to youngest age (˂35 years of age) after adjusting for the remaining explanatory factors included in the model (gender, jaw type, and jaw sector) (table 5). discussion this study was done for its importance in implantology because significant correlations found between bone quality and implant stability parameters indicate that clinicians may predict primary stability before implant insertion, and they may modify their treatment plans (i.e., implant locations, longer healing periods) before implant surgery, where the bone quality is poor (15), although hu values alone could be a misleading diagnostic tool for the determination of bone density (16). most of previous studies suggested that bone density is more in males than females (17), young than old age people (18) and in mandible than maxilla (19) and this was proved in this study. in the present study, the anterior mandible sector presents higher bone density than the premolar and molar sectors in the mandible, followed by bone densities in the sectors of maxilla and this data is in agreement with farrécvijetićavdagić et al (17). this data is in agreement also with norton and gamble (18). however, in their study, they identified a higher mean bone density in the anterior region of the maxilla than in the posterior region of the mandible, 696hu and 669hu respectively. whereas, we observed higher density values in the posterior of the mandible than in the anterior of the maxilla, 613.1 hu and 541.7 hu respectively. moreover, in this study, it was detected a mean density value of 821.3 hu in the anterior mandibular region, lower than that described by norton and gamble (21) (970hu), and even lower than that described by turkyilmaz et al. (22), who described a bone density value in said region of 994.9hu. values are also lower than those described by these authors in the posterior maxilla. this may be due to the patient age of the sample, and with percentage of patients older than the sample average. given that the older the patient, the greater the decrease of bone density. different qualities of bone can be found in any of the anatomical regions studied (anterior and posterior sites of maxilla and mandible), which confirms the importance of a site-specific bone tissue evaluation prior to implant installation (6). in the present study, both jaws were divided in three sectors anterior, premolar, and molar sectors and from the measurements done it is important to have such divisions specially for the mandible because there was significant difference between posterior sector (613.1hu) and both anterior (821.3 hu) and premolar sectors (779.6 hu) with no significant difference between anterior and premolar sectors but unfortunately no previous could be found using same measurements. this may lead to variations in the results with other studies when compared. as a conclusion; ct-scan may provide a valuable aid to predict bone quality at potential implant sites and could be used to assess the change of bone density around dental implants. jaw type (maxilla vs. mandible) and age were the strongest predictors of bone density followed by gender and lastly the jaw sector. references 1. goncalves sb, correia jh, costa ac. evaluation of dental implants using computed tomography. abstract from bioengineering (enbeng), 2013 ieee 3rd portuguese meeting. 2. turkyilmaz i, mcglumphy ea. influence of bone density on implant stability parameters and implant success: a retrospective clinical study. bmc oral health 2008, 8:32 3. lekholm u, zarb ga. patient selection and preparation. in branemark pi, zarb ga, albrektsson t (eds). tissue integrated prostheses: osseointegration in clinical dentistry. chicago: 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http://www.researchgate.net/journal/0004-1254_archives_of_industrial_hygiene_and_toxicology http://www.ncbi.nlm.nih.gov/pubmed?term=hiasa%20k%5bauthor%5d&cauthor=true&cauthor_uid=22203910 http://www.ncbi.nlm.nih.gov/pubmed?term=abe%20y%5bauthor%5d&cauthor=true&cauthor_uid=22203910 http://www.ncbi.nlm.nih.gov/pubmed?term=okazaki%20y%5bauthor%5d&cauthor=true&cauthor_uid=22203910 http://www.ncbi.nlm.nih.gov/pubmed?term=nogami%20k%5bauthor%5d&cauthor=true&cauthor_uid=22203910 http://www.ncbi.nlm.nih.gov/pubmed?term=mizumachi%20w%5bauthor%5d&cauthor=true&cauthor_uid=22203910 http://www.ncbi.nlm.nih.gov/pubmed?term=mizumachi%20w%5bauthor%5d&cauthor=true&cauthor_uid=22203910 http://www.ncbi.nlm.nih.gov/pubmed?term=akagawa%20y%5bauthor%5d&cauthor=true&cauthor_uid=22203910 http://www.ncbi.nlm.nih.gov/pubmed/22203910 j bagh college dentistry vol. 26(1), march 2014 computed tomography oral diagnosis 96 table 1: distribution of the study sample table 2: bone density assessed by ct in hounsfield unite table 3: bone density assessed by ct in hounsfield unit according to jaw type % n age group (years) 34.2 41 <35 43.3 52 35-49 22.5 27 50+ 100.0 120 total gender 50.0 60 female 50.0 60 male 100.0 120 total p n se sd mean range 0.006 gender 60 24.06 186.3 581.5 238-987 female 60 26.18 202.8 680.2 340-1135 male 0.001 age group(years) 41 31.47 201.5 716.1 238-1135 <35 52 25.81 186.2 623.9 268-1135 35-49 27 31.82 514.7 514.7 246-998 50+ 0.001 upper jaw vs. lower jaw 60 27.25 738.0 738.0 238-1135 mandible 60 14.65 523.6 523.6 246-784 maxilla 0.006 gender 60 24.06 186.3 581.5 238-987 female 60 26.18 202.8 680.2 340-1135 male 0.001 age group(years) 41 31.47 201.5 716.1 238-1135 <35 52 25.81 186.2 623.9 268-1135 35-49 27 31.82 514.7 514.7 246-998 50+ 0.001 upper jaw vs. lower jaw 60 27.25 738.0 738.0 238-1135 mandible 60 14.65 523.6 523.6 246-784 maxilla p n se sd mean range 0.006 gender 60 24.06 186.3 581.5 238-987 female 60 26.18 202.8 680.2 340-1135 male 0.001 age group(years) 41 31.47 201.5 716.1 238-1135 <35 52 25.81 186.2 623.9 268-1135 35-49 27 31.82 514.7 514.7 246-998 50+ 0.001 upper jaw vs. lower jaw 60 27.25 738.0 738.0 238-1135 mandible 60 14.65 523.6 523.6 246-784 maxilla j bagh college dentistry vol. 26(1), march 2014 computed tomography oral diagnosis 97 table 4: bone density assessed by ct in hounsfield unit according to jaw sectorin each gender using 5th-95th percentile table 5: multiple regressions with bone density as the dependent (outcome) range mean sd se n 5th-95th percentile female mandible anterior sector 238-873 629.9 233.6 73.87 10 238-873 premolar sector 659-987 808.8 118.2 37.37 10 659-987 molar sector 376-892 586.4 185.8 58.75 10 376-892 total 238-987 675.0 203.9 37.22 30 268-947 maxilla anterior sector 345-658 502.4 101.4 32.07 10 345-658 premolar sector 382-687 510.0 100.7 31.85 10 382-687 molar sector 246-658 451.2 112.3 35.52 10 246-658 total 246-687 487.9 104.7 19.11 30 345-658 male mandible anterior sector 876-1135 1012.7 78.7 24.89 10 876-1135 premolar sector 646-876 750.4 68.5 21.65 10 646-876 molar sector 340-1082 639.7 198.4 62.75 10 340-1082 total 340-1135 800.9 202.3 36.93 30 407-1135 maxilla anterior sector 408-743 581.0 117.0 37.01 10 408-743 premolar sector 436-784 559.9 136.0 43.02 10 436-784 molar sector 398-657 537.3 85.4 27.00 10 398-657 total 398-784 559.4 112.2 20.48 30 408-779 partial regression coefficient p standardized coefficient (constant) 876.7 <0.001 male gender to females 101.6 <0.001 0.255 upper jaw to lower jaw -208.6 <0.001 -0.523 premolar to anterior sector 1.5 0.96 [ns] 0.004 molar to anterior sector -93.5 0.005 -0.221 age group(years) -0.320 35-49 to < 35 -85.8 <0.001 50+ -171.6 <0.001 type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p): 1817-1869, issn (e): 2311-5270 1 research article effect of artificial aging test on peek cad/cam fabricated orthodontic fixed lingual retainer riyadh abdulhamza ruwiaee1, akram faisal alhuwaizi2 1 ph.d. student, orthodontic department, college of dentistry, university of baghdad, baghdad, iraq. 2 professor, orthodontics, orthodontic department, college of dentistry, university of baghdad, baghdad, iraq. *correspondence: riyadhalseebawi@yahoo.com abstract: background: the purpose of this study was to evaluate the effect of in vitro long-term simulation of oral conditions on the bond strength of peek cad/cam lingual retainers. material and methods: the sample consisted of 12 peek cad/cam retainers each composed of 2 centrally perforated 3x4mm pads joined by a connector. they were treated by 98% sulfuric acid for 1 minute and then conditioned with single bond universal and bonded to the lingual surface of premolar teeth by 3m transbond tm system. half of the retainers were artificially aged using a 30-day water storage and 5000 thermocycling protocol before bond strength testing to compare with the non-aged specimens. results: the artificially aged retainers showed a marginally lower bond strength than the non-aged retainers. however, independent sample t-test indicated that this difference was statistically not significant. conclusion: the durability of the peek lingual retainer adhesive system has been confirmed using the well-known oral simulating artificial aging protocol of water storage and thermocycling. keywords: peek, fixed lingual retainer, single bond universal, artificial aging introduction after orthodontic appliance removal, a significant amount of work is yet to be done (1). the retention phase is a vital part after active orthodontic treatments and in most cases, long-term retention is recommended (2). since fixed retainers have better esthetics and patient acceptance, they are highly recommended by orthodontists (3). however, poor adaptation and weak durability play an important role in failure of conventional fixed retainers (4). depending on the wire materials and manufacturing processes, various types of fixed retainers have been described (5). in recent years, cad–cam systems has been used for providing of fixed retainers. however, the studies in this area are limited. when compared to the traditional method, the cad/cam technology is more efficient in producing fixed retainers (6). two recent articles reported the fabrication of a round cad–cam nickel-titanium and rigid zirconium bar as a bonded fixed retainer (7,8). alternatively, advanced peek (poly-ether-ether-ketone) cad cam retainer can be anatomically adapted onto teeth to create a strong, durable, tooth-colored, biocompatible retainer; and its flexibility provides physiological teeth movement (9). received date: 10-10-2021 accepted date: 10-12-2021 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/license s/by/4.0/). https://doi.org/10.26477/jbcd .v34i2.3147 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3086 https://doi.org/10.26477/jbcd.v34i1.3086 j. bagh. coll. dent. vol. 34, no. 2. 2022 ruwiaee and alhuwaizi 2 this organic thermopressed peek polymer is a unique material and now widely used in engineering, medical and dental applications (10). peek has excellent chemical and mechanical resistance even at higher temperatures (11). the optimal design of a peek cad/cam lingual retainer had centrally perforated pads to allow the escape of excess composite and allow efficient light cure penetration. these pads are joined by a connector with occlusal support for better adaption. (12) one minute of 98% sulfuric acid etching before conditioning with single bond universal was shown to be the strongest adhesive protocol for bonding of peek retainers (13). the objective of this study was to investigate the effect of artificial aging of peek retainers using long-term water storage and thermocycling as an alternative to oral conditions. materials and methods the proximal surfaces of premolar teeth were reduced to reach a tooth width of 6mm to approximate the width of a lower incisor. each two teeth were paired in intimate contact and fixed in the plastic mold so that the long axis of the teeth was perpendicular to the mold's base. then cold cure acrylic was poured into the mold. the teeth model was scanned and transferred to the lab using the smart optic digital scanner. the file was opened in exocad software to create a virtual peek retainer with a thickness of 0.8mm (9). the final design had two pads (3mm wide and 4mm high) joined by connector (2mm in height) with occlusal supports for simpler seating and better precision (12). the virtual design was then transferred to the coritec 250i cad/cam system milling engine (imes-icore gmbh, leibozgraben, germany) which was loaded with a blank of dental peek (juvora™ dental disc; juvora ltd, wyre, lancashire, uk) to produce a smooth and passive peek retainer. in the center of each pad, a 1mm hole was drilled. the retainers were then treated for 60 seconds with 98% sulfuric acid, washed with distilled water, and dried using oil-free compressed air. the pads were then conditioned with single bond universal (3m espe, deutschland gmbh, germany) by rubbing for 20 seconds, moderate air blowing for 10 seconds, and led light curing for 10 seconds with 1700 mw/cm2 intensity in intimated contact. the lingual surfaces of the premolars were polished with pumice, washed with water, air dried, etched with 35% phosphoric acid, washed with water, and dried for 20 seconds. transbond xt primer was then applied carefully, air-blown, and light cured for 20 seconds. following that, transbondtm lr adhesive was applied to the peek pad and adhered to the enamel with occlusal support guide for better fitness. after removing the extra adhesive, the teeth were light-cured for a total of 40 seconds, 20 seconds each on the mesial and distal sides. then the occlusal rests were separated with a turbine and removed. before the bond strength test, the specimens were kept in distilled water for 24 hours at 37°c (13). j. bagh. coll. dent. vol. 34, no. 2. 2022 ruwiaee and alhuwaizi 3 half of the specimens were artificially aged for 30 days in distilled water before being exposed to 5000 heat cycles between 5°c and 55°c with a 15-second dwell duration on a customized automated digital thermocycling system (21). then bond strength was measured with a universal testing machine (instron 5965, instron, pfungstadt, germany) at a crosshead speed of 1 mm/min. the specimens were held in place using a specific fixture, and the applied force was directed along the occluso-apical axis of teeth to simulate the initial bite force. the edge of the shearing rod was positioned in the middle of the connector. the load on the wire was raised until debonding occurred and bond strength was recorded in newton (n) (figure 1). figure 1: bond strength test of peek retainer. statistical analysis the spss statistical software (spss version 22, ibm, armonk, ny, usa) was used. bond strength results were statistically analyzed with independent sample t-test with a significance level of 5%. results the artificially aged retainers gave slightly less bond strength (265.8 n) than the non-aged samples (270 n) as shown in figure 2. however, independent sample t-test indicated that this difference was statistically not significant as shown in table 1. figure 2: bond strength of peek retainer with and without aging. j. bagh. coll. dent. vol. 34, no. 2. 2022 ruwiaee and alhuwaizi 4 table 1: t-test of the sbs of peek retainer with and without aging. groups group difference t-test d.f. p value with aging -1.228 11 0.247 without aging discussion after confirming of the optimal design and adhesive system (12-13), the in vitro bond strength of retainer after long-term simulation of oral conditions seems necessary before clinical uses in accordance with kern et al. (14). since the bonded peek retainer is exposed to the salivary fluid and thermal changes of oral environment at the same time, water storage and thermal cycling were explored in this study as artificial aging protocol for in vitro testing of bond strength as previously recommended (15). according to the iso standard, artificial aging was 500 cycles at 5 and 55°c. however, for efficient aging, this number of cycles is very low (16). because oral temperature is difficult to estimate, 5000 thermal cycles resemble oral conditions from 6 months (17) to 4-5 years of service (18). in orthodontic researches, a variety of thermocycles have been used; 6000 cycles at 5–55°c (19), 10000 thermocycles (20). our specimens were thermally cycled for 5000 cycles at 5 to 55oc after 30 days of water storage (21). the impact of oral thermal changes on the orthodontic adhesives should be determined (17). this thermal fluctuation can reduce the bond due to the hydrolytic effect on the interface components (22); or following aging, increase in bonding as result of post polymerization process (23). however, peek retainer showed non-significant differences of bond strength after aging test. an optimal degree of curing (dc) required sufficient light power and curing time. incomplete dc means increase unreacted monomers resulting in increased water input and softening of the adhesive matrix (24). the small surface area and thin adhesive layer peek retainer may enhance the preand post-polymerization process. the central hole allows the curing light to penetrate deeper in the resin resulting in increasing the dc. furthermore, the bonded peek pads cover nearly all the resin and act as protective barrier from the oral environment. this may enhance the durability of the peek retainer. in this study, artificial aging slightly decreased bond strength than the non-aged samples. stawarczyk et al. (16) attributed the decreased bond strength to rupture of the covalent bonds by water molecules following artificial aging. the comparison of peek adhesion with other studies should be done with caution and the following factors should be considered; type of peek, surface treatment, adhesive, number of thermocycles, duration of water storage, adhesion to dentin or enamel, and the type of test used (24). for example, caglar et al. (25) used 5000 thermocycles with no water storage, çulhaoğlu et al. (20) used 10000 thermocycles with different adhesive systems. j. bagh. coll. dent. vol. 34, no. 2. 2022 ruwiaee and alhuwaizi 5 finally, the findings of this experiment revealed that after using long duration water storage and thermal cycling as a method of artificial aging, there were no significant variations in bond strength of peek retainer to enamel. conflict of interest: none. references 1. proffit wr, fields hw, larson be, et al. contemporary orthodontics. 6th ed. philadelphia: elsevier; 2019. 2. little rm, riedel ra, artun j. an evaluation of changes in mandibular anterior alignment from 10 to 20 years postretention. am j orthod dentofacial orthod. 1988; 93(5): 423–428. 3. pratt mc, kluemper gt, hartsfield jk jr, et al. evaluation of retention protocols among members of the american association of orthodontists in the united states. am j orthod dentofacial orthop. 2011; 140(4): 520–526. 4. kartal y,kaya b. fixed orthodontic retainers: a review. turk j orthod. 2019; 32(2):110-114. 5. ma r, tang t. current strategies to improve the bioactivity of peek. int j mol sci. 2014; 15: 5426-45. 6. xiaolei hu, jingya linga, xiaomian wu. the cad/cam method is more efficient and stable in fabricating of lingual retainer compared with the conventional method. biomed j sci & tech res 18(3)-2019. 7. zreaqat m, hassan r, hanoun af. a cad/cam zirconium bar as a bonded mandibular fixed retainer: a novel approach with two-year follow-up. case rep dent.2017 jul 27;2017. 8. kravitz nd, grauer d, schumacher p, et al. memotain: a cad/cam nickel titanium lingual retainer. am j orthod dentofac orthop. 2017;151(4):812-5. 9. zachrisson p. a new type of fixed retainer. orthod practice-us 2018, https://orthopracticeus.com/a-new-type-of-fixed-retainer. 10. bathala l, majeti v, rachuri n, et al. the role of polyether ether ketone (peek) in dentistry a review. j med life. 2019;12(1):5–9. 11. kurtz sm, devine jn. peek biomaterials in trauma, orthopedic, and spinal implants. biomaterials. 2007;28(32): 4845–4869. 12. ruwiaee ra, alhuwaizi af. optimization of cad/cam fabricated peek orthodontic fixed lingual retainer adhesion to enamel. int med j 2021; 28, suppl. 1: 69-73. 13. ruwiaee ra, alhuwaizi af. optimal design of peek cad/cam fabricated orthodontic fixed lingual retainer. turk j physiother rehabil; 32(3): 1373443. 14. kern m, barloi a, yang b. surface conditioning influences zirconia ceramic bonding. j dent res 2009; 88:817–22. 15. wegner sm, gerdes w, kern m. effect of different artificial aging conditions on ceramic/composite bond strength. int j prosthodont. 2002;15:(3). j. bagh. coll. dent. vol. 34, no. 2. 2022 ruwiaee and alhuwaizi 6 16. stawarczyk b, jordan p, schmidlin pr, et al. peek surface treatment effects on tensile bond strength to veneering resins. j prosthet dent. 2014;112(5):1278-88. 17. gale ms, darvell bw. thermal cycling procedures for laboratory testing of dental restorations. j dent. 1999;27(2):89–99. 18. younis m, unkovskiy a, elayouti a, et al. the effect of various plasma gases on the shear bond strength between unfilled polyetheretherketone (peek) and veneering composite following artificial aging. materials (basel). 2019; 12(9): 1447. 19. faltermeier a, rosentritt m, faltermeier r, et al. influence of filler level on the bond strength of orthodontic adhesives. angle orthod 2007; 77:494e8. 20. çulhaoğlu ak, özkır se, şahin v, et al. effect of various treatment modalities on surface characteristics and shear bond strengths of polyetheretherketone-based core materials. j prosthodont. 2017;39:1–6. 21. stawarczyk b, bähr n, beuer f, et al. influence of plasma pretreatment on shear bond strength of self-adhesive resin cements to polyetheretherketone. clin oral invest 2013;18:163–70. 22. de munck j, mine a, poitevin a, et al. metaanalytic review of parameters involved in dentin bonding. j dent res. 2012; 91:351-357. 23. bähr n, keul c, edelhoff d, et al. effect of different adhesives combined with two resin composite cements on shear bond strength to polymeric cad/cam materials. dent mater j 2013; 32: 492–501 24. khalil sk, allam ma, tawfik wa. use of ft-raman spectroscopy to determine the degree of polymerization of dental composite resin cured with a new light source. eur j dent. 2007; 1: 72-79. 25. caglar i, ates sm, duymus zy. an in vitro evaluation of the effect of various adhesives and surface treatments on bond strength of resin cement to polyetheretherketone. j prosthodont. 2018;28(1):e342–e349. peek cad / cam من المصنوع األسنان لتقويم الثابت اللغوي التجنيب على االصطناعية الشيخوخة اختبار تأثير العنوان: 2 الحويزي فيصل أكرم 1 الرويعي الحمزة عبد رياض الباحثون: المستخلص: .الحاسوب بمساعدة والمصنع المصصم كيتون اثير اثير البولي مادة من المصنوع اللساني االسنان مثبت رابطة قوة على المختبر في الفموية للظروف المدى طويلة المحاكاة تأثير تقييم : الهدف مقاس مركزيًا مثقبتين وسادتين من مثبت كل يتكون .الحاسوب بمساعدة والمصنع المصصم كيتون اثير اثير البولي مادة من المصنوع لساني اسنان مثبت 12 من العينة تتكون: والطرق المواد ألسنان اللساني بالسطح ولصقها single bond (universal)الالصق باستخدام ترطيبها تم ثم واحدة دقيقة لمدة ٪98 بنسبة الكبريتيك بحمض معالجتها تمت بموصل متصلتين ملم 4× 3 القوة اختبار قبل 5000 الحراري التدوير وبروتوكول يوًما 30 لمدة المياه تخزين باستخدام اصطناعيا شيخوختها تم قد العينه نصف (3m transbond tm). نظام بواسطة الضواحك .االمشيخه غير العينات مع ومقارنتها الرابطة . اإلحصائية الناحية من مهًما يكن لم االختالف هذا أن إلى للعينة المستقل t اختبار أشار ، ذلك ومع. المشيخ غير الخدم من هامشي بشكل أقل رابطة قوة اصطناعيا المشيخه العينه أظهرت: النتائج طريق عن االصطناعية الشيخوخة محاكاة بروتوكول باستخدام الحاسوب بمساعدة والمصنع المصصم كيتون اثير اثير البولي مادة من المصنوع اللساني االسنان مثبت متانة تأكيد تم: الخالصة . الحراري والتدوير بالمياه التخزين اعيةاالصطن الشيخوخة ، اللساني االسنان مثبت ، كيتون اثير اثير البولي: الرئيسية الكلمات yaseen.doc j bagh college dentistry vol. 26(4), december 2014 the initial stability restorative dentistry 95 the initial stability of dental implant with horizontal plate (an in vitro study) yaseen h. motea, b.d.s. (1) basima m.a. hussein, b.d.s., m.sc., ph.d. (2) abstract background: the initial (primary) stability is one of the factors that play an important role in the success of the dental implants. the purpose of this study was to evaluate the initial stability of dental implant with horizontal plate by using five analytical tests: insertion torque, removal torque, resonance frequency analysis, push-in test and pull-out test. materials and methods: two different lengths of dental implants (5mm and 10mm) were tested in this study; each dental implant was 4mm in diameter with a square threads shape of 1mm pitch and 0.5mm depth. the crestal area was 4.2mm diameter contained a right angle margin circumferential ring while the apical area was tapered with two self-tapping grooves. in this study, the initial stability of dental implants’ design was compared with initial stability of dental implants of the same dimensions and design that engage horizontal plates of 1.5mm thickness at the apical part. all dental implants were implanted into a solid rigid polyurethane foam blocks (artificial bone) of 0.48g/cm3 density and tested by the five initial stability tests. each test was done with forty samples (twenty samples of 5mm length and twenty samples of 10mm length). results: the statistical analysis was performed and the result showed that there was very highly significant difference between dental implants with the horizontal plates and dental implants without the horizontal plates of both 5mm and 10 mm lengths in four initial stability tests which were insertion torque, removal torque, push-in test and pull-out test. the statistical analysis of the resonance frequency analysis showed that there was non-significant difference between dental implants with the horizontal plates and dental implants without the horizontal plates of both lengths. conclusion: these results implied that the dental implants with the horizontal plates had better primary stability compared with the dental implants without the horizontal plates confirming that the horizontal plates enhanced the primary stability of the dental implants. key words: initial stability, dental implant, horizontal plate. (j bagh coll dentistry 2014; 26(4):95-101). introduction despite the progress in the materials and designs of dental implants, the potential for clinical failure is a significant concern for both dentists and patients. the initial stability is an important factor affecting the success rate of implant treatments (1). initial (primary) stability is the mechanical coherence between bone and dental implant fixture immediately after implantation. it is well known that primary stability plays an essential role in successful osseointegration (2). the lack of primary stability had been assumed to be the causative factor for early implant failure (3). achieving stability depends on the bone density, the surgical technique, and the microscopic and macroscopic morphology of the implant used (4). the final clinical success of oral implants is determined by various implant and non-implant related parameters. implant-related parameters are implant shape, implant surface configuration and implant surface composition. non-implant-related parameters are mainly dealing with the skills of the surgeon, health condition of the patient and final loading protocol of the implant supported prosthetic construction (5). the solid rigid polyurethane foam blocks were widely used as an alternative for human jaw bones (6). in order to simulate jaw bone the density of the polyurethane block should be almost similar to the natural jaw bone density. (1) assistant lecturer. faculty of dentistry, dijlah university college. master student at the time of study conduction. (2) assistant professor. department of prosthodontics, college of dentistry, university of baghdad. materials and methods cylindrical dental implants used in this study were mechanically machined from 4.2mm commercially pure titanium rods by using lathe machine. each implant had 4mm body diameter and 4.2mm crestal diameter, the shape of the threads were square with 1mm pitch and 0.5mm thread depth. the crest modules were 0.2mm wider than the body diameter and contained a circumferential ring with right angled margins followed by a crestal smooth 0.5mm length collar. the apical portion was tapered, flat ended and contained two self-tapping grooves (7). two lengths of dental implants were used in this study 10mm length and 5mm length (fig.:1) both were compared with the same design and length of dental implants but with horizontal plates. fig. 1: dental implants fixtures j bagh college dentistry vol. 26(4), december 2014 the initial stability restorative dentistry 96 the horizontal plates were made from commercially pure titanium disks. each plate was 9mm length, 9mm width and 1.5mm thickness. the shape of the horizontal plate was square with one curve side; the other three sides contained inner slots for the mounting of the insertion guide. the plate had five holes one at the center with 4mm diameter and contained inner threads similar to the implant threads and the other four located at each corner of the plate with 1mm diameter (8) (fig.: 2). the horizontal plate engages the dental implant at the apical area (0.5 mm above the apical end). solid rigid polyurethane foam blocks with a bone density of 0.48 g/cm3 were chosen (9). this type of artificial bone had definite mechanical properties of 18mpa compressive strength, 12mpa tensile strength and 7.6mpa shear strength (6). the artificial bone specimens’ dimensions that selected in this study were 3cm length, 4cm height and 1.1cm thickness. drilling procedures each artificial bone block specimens were attached to the vice of the drilling engine stand (fig.:3) (that help to standardize drilling angulation and depth of the implant site). the depth of the drilling was determined by the side gauge that present on the drilling engine stand. implant site preparation was done at drilling speed of 2500 rpm (10) with distilled water cooling by using disposable syringes. fig. 3: drilling engine stand for the dental implants without the horizontal plates, the drilling procedure was started by attaching the bone block to the vice of the drilling engine stand then the drilling started by using 2.8mm stainless-steel straight drill with distilled water cooling until it reach 5mm depth in case of 5mm dental implant and 10mm depth for 10mm dental implant. then the drilling continued by gradually increasing the straight drills sizes (3.3mm then 3.8mm diameter) (7) ,this procedure also done under distilled water cooling. the drilling procedure for the dental implants (5mm) with the horizontal plates was started by attaching the bone block to the vice of the drilling engine stand and a 5mm dental implant drilling guide was held on the top of the block then the implant site preparation started with 2.8mm stainless-steel straight drill passing through the guide to a 5mm depth in the bone block (fig.: 4) in the presence of a distilled water cooling. fig. 4: drilling guide and 2.8mm drill after that the drilling guide was fixed to the block by using a screw of 2.9mm diameter (fig.:5) then with copious amount of water cooling the horizontal plate site preparation started by using 1.4mm thickness disk drill (8) that run along the drilling guide’s slot toward the bone block until 10mm (inside the bone) had been reached (until the sliding area touched the bone block) (fig.: 6). the drilling guide could be replaced by a stereolithographic surgical template. fig. 5: drilling guide fixed by screw fig. 6: horizontal plate site preparation fig. 2: the horizontal plate j bagh college dentistry vol. 26(4), december 2014 the initial stability restorative dentistry 97 after horizontal plate site preparation was done the drilling guide should be removed and under distilled water cooling a sequence of gradual straight drills must be used to finish the 5mm implant site preparation. the position of the horizontal plate determined by the drilling guide and the thickness of the sliding area (1mm) and it was 3mm from the top of the bone in case of the 5mm dental implant. fig. 7: bone block after preparation same steps was followed to the 10mm dental implant with horizontal plate site preparation but with only one difference by changing the horizontal plate drilling guide that leaving the horizontal plate in a position of 8mm from the top of the artificial bone block. implants placement and insertion torque measurements: dental implant insertion was done by using manual torque meter (fig.: 8) to measure the maximum torque that was required for complete fixture insertion. for the dental implants without horizontal plate, the fixtures were inserted into the prepared sites and the torque meter’s maximum readings were recorded. fig. 8: torque meter while in case of dental implant with the horizontal plate and after implant site preparation had been finished the next step was the insertion of the horizontal plate. this procedure was done with the aid of the (commercially pure titanium) horizontal plate insertion guide (fig.: 9). fig. 9: horizontal plate insertion guide the horizontal plate insertion guide had been made to engage the three sides’ inner slots of the horizontal plate, the horizontal plate insertion guide must have the same round circumference as the part of the disk drill that enters the bone during horizontal plate site preparation (fig.: 10). fig. 10: horizontal plate insertion guide and disk drill the function of the horizontal plate insertion guide was to hold the horizontal plate to its appropriate position and prevents it from rotation during dental implant insertion (fig.: 11). fig. 11: the horizontal plate and the insertion guide inside bone block after the horizontal plate had been positioned in the bone block, the insertion of the dental implant started (with torque meter) and by using hand the horizontal plate insertion guide would prevent the horizontal plate from movement and rotation. the maximum torque meter’s readings had been recorded for each dental implant. j bagh college dentistry vol. 26(4), december 2014 the initial stability restorative dentistry 98 fig. 12: dental implant in final position resonance frequency analysis: resonance frequencies analysis was performed by using the osstell isq meter (sweden) (fig.: 13). fig. 13: osstell isq meter the specimen of the artificial bone and the implant was mounted to the vice then the smartpeg was attached to the dental implant fixture by using the smartpeg tightening cap then the measurement probe was held close to the top of the smartpeg without touching it (fig.: 14). when the instrument sensed the smartpeg an audible sound emitted giving the isq (implant stability quotient) value on the display. fig. 14: isq value measurements four different directions readings for each dental implant were taken, which were mesial, distal, buccal and lingual sides then the implant stability quotient value (isq value) were averaged. removal torque measurements: the torque meter was used for unscrewing the dental implant fixtures to measure the removal torque values. the removal torque values were measured by taking the maximum reading on the torque meter until the fixtures removed. the unit that used in measuring both insertion torque and removal torque was (n.cm). push-in force measurements: the push-in and pull-out tests were carried out by using a universal testing machine (tinius olsen, u.s.a.). the universal testing machine contained two clamps one on the upper part and one on the lower part. in the push-in test the upper clamp held a metal push-in piece and the lower clamp held bone and implant specimen. after the clamps had been tightened the machine was set to move the upper clamp vertically downward toward the lower clamp at 1mm/min displacement rate (11). the computer that connected to the machine was programed to stop the machine after 5mm displacement and the push-in force value in n would appear on the computer screen. pull-out force measurements: the pull-out test was started by attaching the pullout metal piece to the upper clamp and the boneimplant specimen to the lower clamp after that both machine clamps were tightened. the universal testing machine started by moving the upper clamp vertically upward (away from the lower clamp) at 1mm/min displacement rate until the implant completely pulled out of the artificial bone block (11). the pull-out force (n) would appear on the computer screen. the number of the specimens were forty for each test, twenty samples were of 5mm length (ten without the horizontal plates and ten with the horizontal plates) while the other twenty samples were of 10mm length (ten without the horizontal plates and ten with the horizontal plates). results insertion torque: the minimum and maximum mean values for the insertion torque test of the 5mm and 10 mm dental implants (with and without the horizontal plates) were respectively 27.627 n*cm and 50.538 n*cm. resonance frequency analysis: the minimum mean values for the resonance frequency analysis of the 5mm and 10mm dental implants (with & without the horizontal plates) was 43.125 isq, while the maximum mean value was 46.200 isq. push-in force test: the minimum and maximum mean values for the push-in force test of the 5mm & 10mm dental implants (with and without the horizontal plates) were 865.9 n and 1870.3 n. j bagh college dentistry vol. 26(4), december 2014 the initial stability restorative dentistry 99 table 1: mean values & standard deviations of the insertion torques for dental implants without & with the horizontal plates of both the 5mm and the 10mm implants sd mean (n*cm) n studied groups dental implants 2.425 27.627 10 without the horizontal plates 5mm implants 2.681 36.752 10 with the horizontal plates 1.717 32.502 10 without the horizontal plates 10mm implants 2.257 50.538 10 with the horizontal plates table 2: mean values & standard deviations of the resonance frequency analysis for the 5mm and the 10mm dental implants (without and with the horizontal plates) sd mean (isq) n studied groups dental implants 1.029 43.125 10 without the horizontal plates 5mm implants 1.015 43.850 10 with the horizontal plates 1.224 45.200 10 without the horizontal plates 10mm implants 1.593 46.200 10 with the horizontal plates removal torque: the minimum and maximum mean values for the removal torque test of the 5mm and 10mm dental implants (with and without the horizontal plates) were respectively 22.316 n*cm and 37.627 n*cm. pull-out force test: the minimum and maximum mean values for the pull-out force test of the 5mm and 10mm dental implants (with & without the horizontal plates) were respectively 107.050 n and 874.600 n. table 3: mean values & standard deviation of the removal torques for dental implants without and with the horizontal plates at the two different lengths (5mm and 10mm) sd mean (n*cm) n studied groups dental implants 1.886 22.316 10 without the horizontal plates 5mm implants 1.753 29.439 10 with the horizontal plates 2.155 28.691 10 without the horizontal plates 10mm implants 2.633 37.627 10 with the horizontal plates table 4: mean values & standard deviation of the push-in force tests for dental implants without and with the horizontal plates of 5mm and 10mm lengths sd mean (n) n studied groups dental implants 58.819 865.9 10 without the horizontal plates 5mm implants 58.918 1835.7 10 with the horizontal plates 79.631 1028.5 10 without the horizontal plates 10mm implants 54.583 1870.3 10 with the horizontal plates to compare between means in each test an independent sample t-test was performed between dental implants without the horizontal plates and dental implants with the horizontal plates for both 5mm and 10mm lengths. the result showed that there was very highly significant difference (p-value ≤ 0.001) between dental implants with the horizontal plates and dental implants without the horizontal plates of both 5mm and 10 mm lengths in four initial stability tests which were insertion torque, removal torque, push-in test and pull-out test, while the statistical analysis of the resonance frequency analysis showed that there was non-significant difference (p-value ≥ 0.05) between dental implants with the horizontal plates and dental implants without the horizontal plates of both lengths. j bagh college dentistry vol. 26(4), december 2014 the initial stability restorative dentistry 100 table 5: mean values & standard deviations of the pull-out force tests for 5mm and 10mm (dental implants without the horizontal plates and dental implants with the horizontal plates) sd mean n studied groups dental implants 7.041 107.050 10 without the horizontal plates 5mm implants 29.868 485.000 10 with the horizontal plates 30.548 326.450 10 without the horizontal plates 10mm implants 85.676 874.600 10 with the horizontal plates discussion in this study, the design of dental implant had been chosen according to the parameters that help to increase dental implants’ success rate. these parameters enhance many aspects like increasing initial stability, providing favorable surface area to allow optimum stress distribution and others. the shape of the threads was square which agreed with chun et al. (12), who concluded that the square thread design has a beneficial shape for occlusal loading compared with other thread designs. in agreement with strong et al. (13), the thread pitch and thread depth had been chosen to provide maximum surface area without affecting the fixture mechanical properties. the wider crestal area had benefits of increasing initial stability and reducing stresses by increasing surface area which agreed with misch (14). the taper self-tapping apical area had been made to facilitate fixture insertion through the bone and the horizontal plate that agreed with misch (7). the design of the horizontal plate with four holes was made to allow sufficient blood supply across it in case of using the plate for an in vivo studies (8). the solid rigid polyurethane foam blocks’ (artificial bone blocks) density had been chosen to simulate the natural trabecular bone density which agreed with tabassum et al. (9). many methods had been used to measure dental implant stability and detect stability problems. several attempts, such as those which were done by akkocaoglu et al. (15) and sakoh et al. (16), used insertion and removal torque to determine the conditions of the implant–bone interface. however, these methods could only be used during or after implant placement; they could not be used for a longterm assessment. therefore, there clinical use in implant stability assessment is limited. primary stability could be measured after implant placement and for long term assessment using the resonance frequency analysis (rfa). the rfa technique had numerous advantages in implant stability assessment including non-invasiveness, nondestructiveness and instant determination of results (17). the assessment of shear force of the bone–implant interface using the pull-out test which was done by pfeiffer et al. (18) and the push-in test that was done by wu et al. (19), had been widely used to determine the mechanical strength of the bone–implant integration. in this study, the evaluation of the initial stability for dental implants was done by using five mechanical assessments that were commonly used in biomedical research for primary stability. the results of this study indicated that implants with horizontal plates showed significantly higher values in four biomechanical assessments, but the rfa did not show this difference. these results implied that dental implants with horizontal plates had better primary stability compared with implants without horizontal plates in this type of bone density. in artificial bone models implants with horizontal plates showed statistically higher mean insertion and removal torque values compared with implants without horizontal plates. the difference in the contact areas, which were associated with dental implant design, horizontal plate design and bone type could explain these results. the optimum torque value is influenced by the geometry of the screw, the contact relationships between the screw and its (bore and threads), the friction coefficient and the properties of the materials used (20). as mentioned above the maximum torque depended on the properties of the materials that are joined together. in this study, the dental implants without the horizontal plates fixtures were made of commercially pure titanium and joined artificial bone made of solid rigid polyurethane foam while in case of the dental implants with the horizontal plates; the commercially pure titanium fixtures joined the solid rigid polyurethane foam of artificial bone and also joined the commercially pure titanium horizontal plates, so the difference in the properties of the materials that joined together in the above two groups explain the change in the insertion and removal torque values (increased in dental implants with the horizontal plates). in this study, statistics of the resonance frequency analysis showed that there was non-significant difference between dental implants with the horizontal plates and dental implants without the horizontal plates, these results might be due to the position of the horizontal plates in a deep part from the marginal bone-implant contact area which agreed with kim and lim (11) who compared the primary j bagh college dentistry vol. 26(4), december 2014 the initial stability restorative dentistry 101 stability between dental implants with self-tapping blades and dental implants without self-tapping blades. they concluded that the isq values do not mirror the bone–implant contact at deeper parts, but rather at the marginal bone region. these results also agreed with akkocaoglu et al. (15), who made a radiographic evaluation study and suggested that bone contact, particularly at the marginal region, plays a decisive role in the isq value obtained. a pull-out test is another indirect test of an implant’s anchorage potential. it usually measures the tensional force (applied vertically to the surface of bone into which an implant has been inserted) necessary to pull the implant out of bone. the force is applied parallel to the long-axis of the implant (21). since the pull-out force directed parallel to the longaxis of the dental implant while the horizontal plates positioned perpendicular to the long-axis of dental implant then the implants with horizontal plates required more force to be pulled-out than implants without horizontal plates. this theory could be also applied to the push-in test since the force of push-in also directed parallel to the long-axis of dental implant but in the opposite direction of the pull-out force. that was why dental implants with horizontal plates showed highly statistically significance increase in both pull-out and push-in force than dental implants without horizontal plates. the conclusions that can be drawn from this study are: 1. the dental implants with the horizontal plates had better primary stability compared with the dental implants without the horizontal plates in this type of bone density confirming that the horizontal plates enhanced the primary stability of the dental implants. 2. the resonance frequency analysis could not indicate the initial stability of dental implants at deeper parts of bone-implant interface (horizontal plates’ position) which mean that only the marginal (crestal) region of bone-implant interface affect the isq values. references 1. lioubavina-hack n, lang np, karring t. significance of primary stability for osseointegration of dental implants. clin. oral impl res 2006; 17: 244–250. 2. friberg b, jemt t, lekholm u. early failures in 4,641 consecutively placed branemark dental implants: a study from stage 1 surgery to the connection of completed prostheses. int j oral maxillofac implants. 1991; 6:142– 146. 3. esposito m, hirsch jm, lekholm u, thomsen p. biological factors contributing to failures of osseointegrated oral implants. (ii). etiopathogenesis. eur j oral sci 1998; 106(3): 721-64. 4. toyoshima t, wagner w, klein mo, stender e, wieland m. al-nawas b. primary stability of a hybrid self-tapping implant compared to a cylindrical non-self-tapping implant with respect to drilling protocols in an ex vivo model. clinical implant dentistry & related research 2009. 5. albrektsson t., branemark p.i., hansson h.a., lindstrom j. osseointegrated titanium implants. requirements for ensuring a long-lasting, direct bone-to-implant anchorage in man. acta orthop scand 1981; 52: 79-155. 6. astm f-1839-08: standard specification for rigid polyurethane foam for use as a standard material for testing orthopedic devices and instruments. philadelphia, american society for testing and materials, 2012. 7. misch c.e. contemporary implant dentistry. 3rd ed. st. louis: mosby inc.; 2008. p.200-225. 8. ihde s. principle of boi. germany: springer-verlag; 2005. p.11-25. 9. tabassum a, meijer gj, wolke jgc, jansen ja. influence of surgical technique and surface roughness on the primary stability of an implant in artificial bone with different cortical thickness: a laboratory study. clin oral impl res 2010; 21: 213–20. 10. sharawy m, misch ce, weller n. heat generation during implant drilling: the significance of motor speed, oral and maxillofac surg. 2002; 60:1160-9. 11. kim y, lim y. primary stability and self-tapping blades: biomechanical assessment of dental implants in mediumdensity bone. clin oral impl res 2011; 22:1179–1184. 12. chun h, cheong s, han j, heo s, chung j, rhyu i, choi y, baik h, ku y, kim m. evaluation of design parameters of osseointegrated dental implants using finite element analysis. j oral rehabil 2002; 29: 565–74. 13. strong it, misch ce, bidez mw, et al. functional surface area: thread form parameter optimization for implant body design. compend contin educ dent 1998; 19: 4-9. 14. misch c.e. contemporary implant dentistry. 1st edition, st louis: mosby inc.; 1993. p.194-218. 15. akkocaoglu m, uysal s, tekdemir i, akca k,cehreli mc. implant design and intraosseous stability of immediately placed implants: a human cadaver study. clinical oral implants research 2005; 16: 202–9. 16. sakoh j, wahlmann u, stender e, nat r, alnawas b, wagner w. primary stability of a conical implant and a hybrid, cylindric screw-type implant in vitro. inter j oral & maxillofacial implants 2006; 21: 560–6. 17. west j, oates t. identification of stability changes for immediately placed dental implants. int j oral maxillofac implants 2007; 22: 623-30. 18. pfeiffer m, gilbertson l, goel v, griss p, keller j, ryken t. effect of specimen fixation method on pullout tests of pedicle screws. spine j 1996; 21:1037-44. 19. wu s, lee c, fu p, lin s. the effects of flute shape and thread profile on the insertion torque and primary stability of dental implants. medical engineering & physics 2012; 34: 797– 805. 20. shigley je. mechanical engineering design. kogakusha tokyo: mcgrawhill; 1977. 21. katsavrias g. reliability and validity of measuring implant stability with resonance frequency analysis. a master thesis, saint louis university. 2009. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p): 1817-1869, issn (e): 2311-5270 7 research article effect of optiglaze coating on the staphylococcus aurous and porosity of heat cured acrylic material amal abdul latif rashid 1 1assistant professor, college of health and medical technology, middle technical university baghdad, iraq * correspondence: amal_dentist58@yahoo.com abstract: background: polishing technique for acrylic resin material have great effect on properties of acrylic material and bacterial colonization such as staphylococcus aurous, which are responsible for many acrylic prosthetic infections such as the commonly ocular infections. ineffective polishing technique could affect roughness and subsequently porosity of acrylic materials.so, a new effective method for polishing acrylic was used depending on the use of optiglaze coating material. so, this study aimed to evaluate the effect of optiglaze polishing on porosity of acrylic resin material and staphylococcus aurous activity in comparison to conventional polishing technique. materials and methods: specimen(n=120) were prepared :20 specimens constructed as circle shaped diameter 30mm with 1 mm thickness for porosity test (10 control polishing by conventional technique and 10 polishing by optiglaze technique). other 82 specimens were prepared as circle specimen (6mm diameter and 1mm thickness) for sensitivity and adherences test ( each test have 20 specimens10 control and 10 optiglaze) and 42 specimens for viability test for three dilution,21 specimens for control and 21 for optiglaze (7 specimens for each dilution). porosity were tested by light microscopic while agar well technique, adherence test and viability count test were tested for antibacterial activity of optiglaze against staphylococcus aurous. result: the high mean value for porosity test was recorded by control while low mean value was recorded by optiglaze group with significant differences between them. sensitivity and adherence test high mean value recorded by optiglaze with highly significant differences in comparison to control. viability count test all dilution 10-7 ,10-6, 10-5 showed highly significant reduction in viability count of staphylococcus aurous by optiglaze group in comparison to control. conclusion polishing technique by optiglaze significantly decrease porosity of acrylic resin and this method inhibited growth of staphylococcus aurous, and decrease its viable count (have antibacterial effect) but had less effect in adherence of this bacterial in comparison to control. keywords: : optiglaze coating, staphylococcus aurous, porosity, resin material. introduction acrylic resin for many years, strongly used in prosthesis fabrication due to many reasons such as easy to manipulate, not expensive, good (physical and mechanical) properties, practically, biocompatibility, and more naturally appearance (1,2) but these materials gain overtime, unfavourable properties such as low elasticity, colouring change and even porosity (3,4,5). properties of resin were command associated to materials longevity, such as water sorption, porosity and hardness. these properties could be affected by time because of constant temperature adaptation also due to contact with oral tissue and fluid (6,7). porosity was one of the meaningful clinical properties in dental materials, and bacteria adhesion might be as an index for this property (6,8,9) .since the aesthetic aspect of prosthesis was a significant feature recommended by patients so should compensate their confidence (10). received date: 12-2-2022 accepted date: 22-3-2022 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/jbcd .v34i2.3141 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i1.3087 https://doi.org/10.26477/jbcd.v34i1.3087 j. bagh. coll. dent. vol. 34, no. 2. 2022 rashid 8 adhesion of bacteria on dental prosthesis was followed by aggregation of dental plaque and the porosity, roughness and free energy surface have a major role during this process (11).studies showed the rough surfaces of acrylic was more prone to microbial aggregation and plaque adhesion in comparison to smooth surface (12,13) in all age groups staphylococcus aureus (s. aureus) was acrobat human bacteria in skin and oral cavity can cause hard and soft tissue infections. s. aureus considered a common pathogen of the eye, and could infect external tissues (14). these bacteria attached to any practicable surface causing biofilm attachment (15). biofilms were the characteristic features for the staphylococci strain. staphylococcus aureus could survive viable for long periods in a desiccated phase and had ability to form biofilm (16). divergent polishing techniques was used in to improving acrylic properties, the polish was either mechanical, provided with virous polishing pastes and virous brushes, or chemical (17,18). new method was reported with a photo-polymerized glaze (optiglaze) as surface coating that improve acrylic properties and not contributed on bacterial attachment (19,20). aim of study; to assess the effect of selective polishing technique optiglaze coat (photo-polymerized) on porosity of heat-polymerized poly methyl methacrylate (pmma)resin and on the staphylococcus aurous activity in comparison to conventional mechanical polishing materials and methods preparation of specimens 102 specimens from metal pattern were prepared.20 specimens for testing porosity constructed as circle shaped diameter 30mm and thickness 1mm (21),while 82 specimens for microbiological study (sensitivity, adherences test and viability test) were prepared as circle specimen 6mm diameter and 1mm thickness(22,23) the preparation of specimens done by conventional methods and the wax elimination done by use boiling water, then flask was opened for cooling (at room temperature). heat cure pmma was mixed according to manufacture instruction (stander powder /liquid ratio) packing and curing process was performed by conventional methods (fast procedure) (24). after the curing was completed, the flask left at the bench, allowing to cool gradually until reached room temperature then the flask opened and sample of acrylic was removed out the molds . distribution of sample 102 specimens divided into 4 groups, group 1 for porosity test, group 2 for sensitivity test, group 3 for adherences test (60 specimens each test have 20 specimens10 control polished with conventional technique and 10 polishing by optiglaze technique), group 4 for viability test 42 specimens for three dilution; 21 specimens for control and 21 for optiglaze group (7 specimens for each dilution) finishing and polishing control acrylic samples were finished and polished by conventional technique, after deflasking of samples the flashes were trimmed away from the margins using finishing burs followed by verification j. bagh. coll. dent. vol. 34, no. 2. 2022 rashid 9 the dimensions with a vernier. then polishing procedure accomplished by ruge wheel using pumice with water (1) . the optiglaze group finished according to instruction of manufactural by received a uniform layer of vertex™ lc gloss, glaze (vertex) (fig 1-a) on the surface of the samples (apply a thin layer of with a brush), and photopolymerize about180s using light cure unit (brazil, edg equipment,) (fig1-b) after that no polishing required the surface shines high gloss. porosity test: methods for porosity evaluation: thickness of specimens (before examination) were reducing from each side in order to be examine under microscope. specimens were gritting by use carbide bur and subsequently water cooling, after that smoothing surface done by grit paper of silicon carbide (240) pursued by size (400) then (600) as thin as possible portion was obtained 0.40.5mm, then the control group were polished with pumice and rag wheel and experimental group polished with glaze polishing, then immersion take place in black ink (permanent solution) for 30 minutes, then washing for 10 seconds and using absorbing paper to dry. draw area of (1cm2) width and length as square draw in the center of the specimen and examine under(40x) using light microscope type olympus, japan. number of pores / areas were resolute to each specimens , then the average values calculated to each one (21). isolation and diagnosis of staphylococcus aureus: strain of diagnosed isolated staphylococcus aureus was take from laboratory analysis. initial suspensions of isolated staphylococcus aureus were mixed up and incubated for 24 h. at 37 ◦c, then initial suspensions striped on mannitol salt agar (msa) plates (uk). and incubated for (35 ◦c 48 h), s. aureus colonies with yellowish zones was selecte and re streaked on the trypticase soy agar plates (tsa) to confirm the purity. pure cultures gained on tsa plate subject to biochemical diagnosis by staph id system (uk), and the isolates were processed for the determination of gram’s stain, motility, cell morphology, oxidase and catalase tests also diagnosis confirm by using vitek2compact system(25). agar disk diffusion method: disk diffusion test was completed with mueller hinton agar (mueller-hinton, france) (fig 2) plates, colonies of s. aureus from pure culture hike up by loop. colonies were pendent in five ml of sterilized saline. a bacterial suspension in 0.9% (nacl) solution with its density equal to 0.5 mcfarland barium sulfate standard (1*105 cfu/ml) of the s. aureus isolates. mueller-hinton agar plates were inoculated with a suspension, disks placed by using forceps on the agar then pressed down. after incubation plates for 20 h. at 37°c, diameter of inhibition zone appeared around the disk were measure by ruler (22) figure 1: optiglaze and light cure unit figure 2: mueller-hinton agar j. bagh. coll. dent. vol. 34, no. 2. 2022 rashid 10 adherence test (biofilm formation): adherence test using assay of crystal violet staining, cultures of colonies in trypticase soy broth were dilute in tsb with glucose {2% (w/v)}.96 well polystyrene microplate, italy, were full of with 100 l of dilute culture. then incubated at 37 ◦c for24 h, wells content were pour down turning the plates over and shaking out liquid, washing wells three times by phosphate-buffered saline to take out not adherent cells, wells were washed then dried by air and levels of biomass of biofilm on well surfaces were determined with staining assay by crystal violet (cv). the cells of bacterial in biofilm settled by ethanol then stain by crystal violet {1% (merck)} for 15 min, washing well 3 times by sterile distill water after staining and dried by air, cv bound redaction by added ethanol (95%) and the cv level in ethanol was calculated by means of the optical density (od) with wavelength 360 nm by spectrophotometer (usa), the biofilm assay was determined in triplicate for the all isolates (25). viability test :viable count: staphylococcus aureus diluted in nacl (0.9%), 107cfu/ml (0.5) mcfarland standards suspension was formed by mcfarland densitometer. both specimens (control and glaze polishing) were placed within a tube containing sabouraud dextrose broth (9.9 ml), into which 100 μl of the bacteria suspension was dispensed. final concentration of cells was 105cfu/ml. then incubated at 37◦c for 24 hours, 100 µl of both mixtures were transmitted to 9.9ml nacl (0.9%), then performed tenfold dilution fig (3). 100 µl was taken from the second dilution, spread on tsb plates and incubate aerobically at 37ºc for 24 hours, this dilution taken because it shows a countable range of cfu (30-300) (26,27), in all plates the viable counts were calculated then statistically analysed (28). figure 3: tenfold dilution results table (1) represents descriptive statistics of studied readings in glaze group and control group, such as [mean, s.d, s.e, minimum, and maximum values]. results show that high mean value for porosity was recorded by control group and low mean value was recorded by optiglaze group.. table 1: descriptive of porosity test n min. max. mean s.e s.d optiglaze 10 .00 2.00 .7000 .21344 .67495 control 10 .00 9.00 3.4000 .80554 2.54733 j. bagh. coll. dent. vol. 34, no. 2. 2022 rashid 11 table 2 represents descriptive statistics of studied readings in glaze and control group, such as; minimum, maximum, mean, standard deviation, standard error. results show that high mean value for sensitivity test was recorded by optiglaze group and low mean value was recorded by control group table 2: descriptive of sensitivity test table 3 represents descriptive statistics of studied readings in glaze group and controlled group. such as mean, s.d, s.e, minimum, and maximum values. results show that high mean value for adherence test was recorded by optiglaze group and low mean value was recorded by control group. table 3: descriptive of adherence test figure 4: bar chart for" mean values" of control and optiglaze group for porosity, sensitivity and adherences test table 4 showed minimum and maximum value, mean, standard deviation, standard error of control and optiglaze group for three dilutions that used in viability test, all dilution 10-7 ,10-6 and 10-5 showed the value of mean of viable count of staphylococcus aureus were lower in glaze group than in control group. n min. max. mean s.e s.d optiglaze 10 12.80 13.20 13.0000 .05375 .16997 control 10 11.80 12.20 12.0000 .04714 .14907 n min. max. mean s.e s.d optiglaze 10 .09 .10 .0950 .00021 .00067 control 10 .04 .04 .0400 .00037 .00115 j. bagh. coll. dent. vol. 34, no. 2. 2022 rashid 12 table 4: descriptive of viability count figure 5: bar chart for mean value of three dilutions for viability test as shown in table 5, the ttest between control group and optiglaze group, for porosity test demonstrated significant differences p>0.05 while for sensitivity and adherences test there were highly significant differences p<0.001between them table 5: t-test of porosity, sensitivity and adherence test between control and optiglaze group -p<0.05 significant -p<0.001 high significant table 6 showed the ttest between control group and optiglaze group for viability test, for all dilution there were highly significant differences p<0.001between control and optiglaze group. dilution groups n min. max. mean s.e s.d dilute 10-7 glaze 7 2.8 ͯ 1010 3.2 ͯ 1010 3 ͯ 1010 .04880 .12910 control 7 7.8 ͯ 1010 8.2 ͯ 1010 8 ͯ 1010 .04880 .12910 dilute 10-6 glaze 7 5.9 ͯ 109 6.3 ͯ 109 6.1 ͯ 109 .04880 .12910 control 7 8.9 ͯ 109 9.3 ͯ 109 9.1 ͯ 109 .04880 .12910 dilute 10-5 glaze 7 7.3 ͯ 108 7.7 ͯ 108 7.5 ͯ 108 .04880 .12910 control 7 9.7 ͯ 108 9.9 ͯ 108 9.8 ͯ 108 .03086 .08165 test groups t-test p-value sig porosity test control optiglaze 3.151 .012 s sensitivity test control optiglaze 13.156 .000 hs adherence test control optiglaze 130.444 .000 hs j. bagh. coll. dent. vol. 34, no. 2. 2022 rashid 13 table 6: t-test between control and optiglaze group for viability test figure 6: effect of optiglaze on the viability count of staphylococcus aureus in different dilution (cfu=colony forming unit) discussion the acrylic resin has been used for many years ago for synthesis of dental and ocular prosthesis. porosity result in reduction of mechanical properties of acrylic resin, the surface of acrylic prosthesis must be as less porous as possible ,furthermore to avoid contamination of bacteria and injuries to the tissues, porous facilitate retention of bacteria (10,13) ,acrylic surface smoothing depend on many factors such as storage and methods of cleaning the prosthesis if else any damage can cause scratches that lead to facilitate colonization of bacteria and effect the longevity of the denture(12) . staphylococcus aureus considered most pathogens that associated with increase the possibility of infection especially ocular infection also increase probability of biofilm formation (bacteria adhesion) (20,29) in this study glaze coating for polishing acrylic resin was tested in comparison to conventional mechanical polishing technique on the porosity of acrylic resin material and on staphylococcus aureus activity, since porosity of prosthesis was extremely important, porosity indicates higher abrasives and bacterial colonization. optiglaze coating showed reduction in the porosity of acrylic with signification differences (p<0.05 ) with control group that polished by conventional mechanical technique this might be due to the layer of coat that applied to the acrylic could cause precipitation of nano coat particle on the acrylic surface that protect the acrylic surface leading to reduce surface porous so causing an improved in porosity test this study agree with other study done by goiatoa , et al)2017)(19) that showed optiglaze improved roughness dilutions groups t-test p-value sig diluents 10-7 control – optiglaze 81.009 .000 hs diluents 10-6 control – optiglaze 38.129 .000 hs diluents 10-5 control – optiglaze 105.399 .000 hs j. bagh. coll. dent. vol. 34, no. 2. 2022 rashid 14 and hardness in groups polished by glaze than group polished with mechanical technique even after disinfection regime were subjected. also agree with rutkunas et al 2010(30) that showed acrylic polished with optiglaze has smoother surface. optiglaze coating had greater inhibition zone in comparison to control group the significant differences were highly between them (p<0.01), this indicated that glaze have antibacterial effect that cause inhibition the growth of aureus equal to (13mm ± 0.16997) this antibacterial effect attributed to the nano particle composition of glaze because most nano particle had antibacterial and antifungal effect (31,32). for adherence test the optiglaze group had less effect in adherence (bio film formation) of s. aureus in comparison to control group the significant differences was highly between them ( p<0.01) , this study disagree with nagay etal,2018 (20) who demonstrated that glaze causing decrease in microbial ( staphylococcus aureus ) adhesion to acrylic , the contra versa in result in effect of optiglaze on the adherence of s. aureus may be due to different methods that used to analysis the biofilm formation . effect of optiglaze on the viable count of s. aureus measured by viability count which was an important and subordinate test to asses bacterial activity, viability count test showed in all dilution the optiglaze group showed decrease mean value than in control group with highly significant differences(p<0.01),this indicate that optiglaze coat have antibacterial effect against s. aureus that cause inhibition and decrease the number of viable count of this bacterial it is possible due to nano particle that contain in this product that had effect in inhibition of bacterial growth (31,32) ,there were no previous studies concerned the effect of optiglaze on viability of s. aurous in order to compare with them. conclusion polishing technique by optiglaze significantly decrease porosity of acrylic resin and this method (have antibacterial effect ) inhibited growth of staphylococcus aurous, and decrease its viable count but had less effect in adherence of this bacterial in comparison to control conflict of interest: none. references 1. craig rg., powers jm., john cw. dental material properties and manipulation. eight edition, 2004; p.270-280. 2. mccabe j f. , walls aw. applied dental material. john wiley & sons. 9th edition. 2013; p312. 3. noort, rv. introduction to dental materials, 1st ed. london:mosby. 1994. 4. goiato mc., santos dm., baptista gt., et al. effect of 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rene gc, germán vs., et al.antimicrobial poly (methyl methacrylate) with silver nanoparticles for dentistry: a systematic review. appl. sci. 2020; 10, 4007. بالحرارة المعالجة األكريليك مادة ومسامية الذهبية العنقودية المكورات على optiglaze طالء تأثير العنوان: رشيد امال عبد اللطيف الباحث: المستخلص: وؤلة عن كثير من عدوى تعويضات االكريلك عملية تلميع راتنج االكريلك تمتلك تاثير كبير على خواص االكريلك ومستعمرات البكتيريا مثل بكتيريا المكورات العنقودية الذهبية المسالخلفية: االكريل مادة مسامية على وبالتالي خشونة على تؤثر كافية الغير التلميع عملية العينية. العدوى بالضوء مثل المعالج طالء مادة هي االكريلك لتلميع وفعالة جديدة طريقة جهزت ك,حديثا optiglaze .ب الدراسة هذه من الهدف تاثير التلميع تقنية التلميع optiglaze اعدت الدراسة لتقييم مع بالمقارنة بكتيريا المكورات العنقودية الذهبية مادة االكريلك وفعالية مسامية على يةاالعتياد 10عينات لمجموعة التحكم تم تلميعها بالطريقة االعتيادية و 10ملم لقياس المسامية )1ملم وسمكها 30عينة حضرت على شكل دائرة قطرها20عينة, 102حضرتالمواد والطرق العمل : بواسطة تلميع دائرة 82و optiglazeعينة شكل على حضرت و6عينة القطر الحساسية 1ملم لقياس السمك اختبار ملم )لكل , 20وااللتصاق و 10عينة التحكم مجموعة 10مجموعة optiglazeلل 21عينة لمجموعة السيطرة و 21عينة لقياس قابلية الحياة والنمو لثالث تخافيف, 42(و )optiglaze7 عينات لكل تخفيف (. قيست المسامية بواسطة المجهر الضوئي بينما ضد بكتيريا المكورات العنقودية optiglaze االلتصاق واختبار قابلية الحياة والنمو قيست لمعرفة فعالية الضد البكتيري للتقنية حفر االكار واختبار ما بالنسبة لقياس الحساسية مع وجود فروقات معنوية بينه optiglazeاضهرت اعلى قيمة للوسط الحسابي الختبار المسامية سجلت بواسطة مجموعة التحكم بينما اقل قيمة سجلت بواسطة النتائج بواسطة الحسابي قيمة للوسط الختبار الحياة والنموسجلت جميع التخافيف optiglazeوااللتصاق سجلت اعلى مجموعة التحكم,بالنسبة مع معنوبة عالية فروقات -10 ,6-10, 7-10مع الراتنج مادة مسامية تقلل optiglazeتقنية التلميع ب االستنتاجاتمقارنة مع مجموعة التحكم optiglazeانخفاض معنوي كبيرفي عدد البكتيريا الحية للمكورات العنقودية في مجموعة 5 االعتيادية التلميع تقنية مع مقارنة اقل االلتصاق تاثير ولكن منها الحي البكتيريا عدد وتقلل نموها تثبط حيث, الذهبية العنقودية البكتيريا ضد تاثير ولها االكريلك j bagh college dentistry vol. 29(2), june 2017 the value of oral diagnosis 55 the value of 3 tesla magnetic resonance imaging in assessment of clinically diagnosed temporomandibular joint disorders zeinab ghadhanfer hammod b.d.s., h.d.d. (1) lamia al – nakib b.d.s.,m.sc. (2) abstract background: temporomandibular joint disorder (tmd) is a general term that describe a wide variety of conditions that include myogenic pain, internalderangement, arthritic problem, ankylosis of the joint and growth disorders. the aims of study was to evaluate the value of 3 tesla magnetic resonance imaging in assessment of articular disc position and configuration in patients with temporomandibular joint disorders and to evaluate the correlations of these mri findings with the clinical signs and symptoms. materials and methods: a total forty six (30 study and 16 control) participants aged between18 and 49 years, were examined according to helkimo anamnestic index (questionnaire for anamnesis) and clinical dysfunction index scoring criteria which include clinical examinations of the range of mandibular mobility, impaired tmj function, muscle pain ,tmj pain and pain during mandibular movement. results: there is statistically high significant difference between helkimo anamnestic and clinical dysfunction indices in the cases group (with temporomandibular joint disorders) and controls group with mri findings of disc position and disc configuration, that as the severity of indices increased, there were progression of disc displacement and disc deformity score and shows positive association expressed by significant probability (p) value. conclusion: there is a significant correlation between helkimos’ anamnestic and clinical dysfunction indices and mri findings in patients with internal derangement of temporomandibular joint. key words: tmj, helkimo indices ,3 t mri. (j bagh coll dentistry 2017; 29(2):55-60) introduction temporomandibular joint (tmj) dysfunction is a common condition that, according to some studies, affects up to 28% of the population (1).the most frequent structural (as opposed to muscular) cause of tmd are internal derangement , which involves progressive slipping a displacement of component of temporomandibular joint called the articular disc (2) . internal derangement is defined as a mechanical fault of the joint that interferes with smooth joint function. this is attributed to abnormal interaction of the articular disc, condyle and articular eminence. associated clinical features include articular pain and articular noises (3). the disc displacement is categorized based on the relation of the disc displacement with mandibular condyle. the displacement can be anterior, anterolateral, anteromedial, lateral, medial and posterior (4). absence of ionizing radiation as well as excellent depiction and visualization of soft tissue, disc position and morphology, bone marrow changes, and joint effusions are among the advantages of mri (5,6,7). (1) m.sc. student, oral diagnosis department, college of dentistry, university of baghdad. (2) assistant professor, oral diagnosis department, college of dentistry, university of baghdad. the 3t unit delivers images of better quality as regards evaluability of disc position and shape as compared to 1.5 t mr and thus provides added diagnostic assurance that is critical for therapeutic decisions (8). in this study 3 tesla mri machine was used to evaluate tomporomandibular joint in patients with internal derangement of tmj. materials and methods a prospective study was conducted on 46 patients were attended oral and maxillofacial surgery department in alyarmouk teaching hospital that were refereed to clinic of radiology for mri from over the period of 5 months (september 2014 february,2015). the patients were selected and divided into two groups : 1. case group thirty patients (18-49) years old (22 females and 8 males) were clinically diagnosed as having internal derangements of temporomandibular joint. all patients complain from pain in preauricular area and muscles of mastication ,clicking or crepitation of tmj ,a limitation or deviation in mandibular range of motion, they were again grouped according to severity. j bagh college dentistry vol. 29(2), june 2017 the value of oral diagnosis 56 2. control group sixteen participants (18-46) years old (10 females and six males) with normal tmjs. the patients examined according to helkimo anamnestic index and clinical dysfunction index scoring criteria of temporomandibular disorders which consists of standardized series of diagnostic tests based on clinical signs and symptoms.the clinical examination was done extra and intra orally aextra oral examination. 1.determination of the mouth opening without pain and the mouth opening with pain (un-assisted mouth opening). this accomplished by measuring the inter-incisal distance plus the overbite when the patient open his mouth as wide as he could. a general guide for minimum normal mouth opening is 45mm including the overbite. 2-auscultation the tmj during opening and closing three times at least to detect the joint sound. clicking, cripitation, luxattion or deviation of tmj. 3-determination of masticatory muscles and tmj pain during excursive movement of mandible. determination of the tender points of muscles by palpating muscles bilaterally the temporalis muscle, masseter muscle, medial pterygoid muscle, lateral pterygoid muscle, posterior digastric muscle and sternocleidomastoid muscle. 4examination of tmj pain and tenderness was done by digital palpating of the joint performed from both lateral and posterior aspect, the finger tips were placed over the lateral aspect of both joints simultaneously while the posterior aspect was reached via the external auditory meatus by small finger forced anteriorly. the patient was instructed to do movement of opening, closing, laterotrusion to the right and left and protrusion, then asked if he experienced pain in one movement or more. bintraoral examination the first was done by checking the occlusion of teeth, if there was any premature contact, overlapping of upper anterior teeth, deep over bite, also occlusal midline was checked. mri was carried out with mri 3.0 tesla, achieva philips medical system nederland b.v. with standard head coil ,the patient in a supine position. bite block were used during open mouth position. the data were collected on 256 × 256 matrix giving a pixel size of 0.60 × 0.57 mm. proton density (pd) pblique sagittal (closed and opened mouth). (tr) =528 miliseconds , (te) =13 ms , (fov)=150 mm, flip angle =90° , number of slices =22 slice and slice thickness=2.0 mm. results a significant differences in correlation between helkimo anamnestic index (ai) and mri findings of tmj disc displacement types and morphology.it was found that when the result of helkimo anamnestic highest value 84. 2 % at ai0 (no symptoms from the masticatory index), while lowest value 5.3% the at ai2 (tmj sounds/tiredness in jaws/stiffness in the morning/stiffness on mandibular movements) .at anterior disc displacement with reduction, the highest value 87.1% at ai1 ,while the lowest value 12.9% at ai2. at anterior disc displacement without reduction, the highest value 50.0% at ai1, ai2, while the lowest value0.0% at ai0 (table 1). there was a very high significant differences in correlation between helkimo anamnestic index and mri findings of tmj disc morphology ( p<0.001),with the normal tmj disc (biconcave), the highest value 72.7% at ai0, while the lowest value 6.8% at ai2.in abnormal (elongated /folded /posterior thick band) the highest value 68.8% at ai1, while the lowest value 0.0% at ai0 (table 1). a significant differences in correlation between helkimo dysfunction index and mri findings of tmj disc displacement types and morphology.it was found that when the result of helkimo clinical dysfunction index (di) and the normal tmj disc, the highest value 84.2 % at di0 (clinically asymptomatic), while lowest value 2.6% at di2 (middle dysfunction) and di3(strong dysfunction). at anterior disc displacement with reduction, the highest value 74.2% at di2 , while the lowest value 9.7% at di1(small dysfunction). at anterior disc displacement without reduction the highest value72.7% at di3,while the lowest value 4.5% at di1 (figure1). there was a very high significant differences in correlation between helkimo clinical dysfunction index and mri findings of tmj disc morphology (p<0.001).with the normal tmj disc (biconcave), the highest value 72.7% at di0, while the lowest value 4.5% at di3.in abnormal (elongated/ folded/ posterior thick band) the highest value 50.0% at di2, while the lowest value 0.0% at di0 (figure2). j bagh college dentistry vol. 29(2), june 2017 the value of oral diagnosis 57 table 1: correlation between helkimo anamnestic index and mri findings of tmj disc displacement types and disc morphology. helkimo anamnestic index ai0 ai1 ai2 total mean rank n % n % n % n % median p type of disc displacement <0.001 normal 32 84.2 4 10.5 2 5.3 38 100.0 ai0 23.9 anterior disc displacement with reduction 0 0.0 27 87.1 4 12.9 31 100.0 ai1 57.3 anterior disc displacement without reduction 0 0.0 11 50.0 11 50.0 22 100.0 ai1 68.3 abnormal disc morphology <0.001 normal (biconcave) 32 72.7 9 20.5 3 6.8 44 100.0 ai0 28.6 abnormal (elongated/folded/posterior thick band) 0 0.0 33 68.8 15 31.3 48 100.0 ai1 62.9 figure 1: correlation between helkimo clinical dysfunction index and mri findings of type of disc displacement. figure 2: correlation between helkimo clinical dysfunction index and mri findings of disc morphology. 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% normal anterior disc displacement with reduction anterior disc displacement without reduction 84.2 0 0 10.5 9.7 4.5 2.6 74.2 22.7 2.6 16.1 72.7 r el at iv e fr eq ue nc y (% ) di3 (severe dysfunction) di2 (moderate dysfunction) di1 (mild dysfunction) di0 (clinically asymptomatic) 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% 72.7 0 9.1 8.3 13.6 50 r el at iv e fr eq ue nc y (% ) di3 (severe dysfunction) di2 (moderate dysfunction) di1 (mild dysfunction) j bagh college dentistry vol. 29(2), june 2017 the value of oral diagnosis 58 discussion in present study the correlation analysis between helkimo anamnestic index and mri findings of tmj disc displacement types and morphology showed positive association expressed by significant difference, these findings were in agreement with that reported by hasan and abdelrahman,(9). a very high significant difference in correlation between helkimo anamnestic index and the normal tmj disc( p<0.001), these findings were in agreement with that reported by sano and westesson,(10); emshoff et al.,(11); tognini et al.,(12). these findings were in disagreement with that reported by ribeiro et al., (13) because they said ‘disc displacement is relatively common in asymptomatic individuals’. moreover, arthroscopy and mri have shown that tmjs with anteriorly disc displacement have the capacity to form remodelled retrodiscal tissue that resembles cartilage (i.e., pseudo-disc formation) (14). furthermore, the retrodiscal tissues have adaptive capacity and often respond appropriately to the functional loads placed on the tissues (15). these findings were in disagreement with that reported by muhtarogullari et al. (16) because they said ‘the clinical diagnosis of no temporomandibular disorder is linked to the high rates of internal derangement detection using mri’. maizlin et al.,(15) assessed that only findings of internal derangement in the tmj; and did not evaluate other findings of articular pathology that might have explained symptoms in joints that lacked internal derangement. however, this focused assessment was in keeping with the objective to focus on the correlation between clinical findings and disc displacement.a prospective controlled study will be required for more detailed evaluation of the correlation between mri findings and clinical symptoms (15).joint noises are not sufficient evidence of dysfunction when there are no other corroborating symptoms, although they may be found in patients with tmj disc displacement detected using mri (17). disc displacements in tmj are considered to be factors which may lead to disc deformities, osseous changes and clinical symptoms of temporomandibular disorders (18, 19, 20, 21, 22).a statistically significant correlation between an increased signal on t2-weighted images in the posterior disc attachment and the presence of pain(10).a very high significant difference in correlation between helkimo anamnestic index and mri findings of tmj disc morphology ( p<0.001), these findings were in agreement with that reported by emshoff et al. (11) , kobs et al. (23).these findings were in disagreement with that reported by arayasantiparb et al. (24) because they found no significant relationship between the onset of tmj symptoms and the disc configuration at either closed or open mouth position as well as the transformation of disc shape from closed to open position. this may be due to the lack of complete data on onset of symptoms for this study.kobs et al. (23) agreed with westesson opinion, that if a patient presents with symptoms that can be correlated to the morphologic abnormality diagnosed on imaging studies, the abnormalities are probably responsible for these symptoms. in present study the correlation analysis between helkimo clinical dysfunction index and mri findings of tmj disc displacement types and morphology showed positive association expressed by significant difference, these findings were in agreement with that reported by saeed (25), hasan and abdelrahman(9),imanimoghaddam et al. (26).these findings were in disagreement with that reported by aidar et al. (27) because of they were assessed ‘there is a low correlation between mri disc displacement detections and the extent of tmj pain and dysfunction’. anterior disc displacement is a common finding in tmj internal derangement. the results show a direct relationship between the degree of anterior disc displacement and mri findings of other tmj soft tissues and bone abnormalities as well as the severity of clinical manifestations, so early mri detection and reporting of anterior disc displacement degree and other mri findings might help clinicians in full assessment and determining the strategy of management of tmj dysfunction (9).avery high significant difference in correlation between helkimo clinical dysfunction index and the normal tmj disc (p<0.001).the mri is a modality of choice for diagnosis of tmj disc displacement as warranted and supplementary method to clinical examination for confirming the presence or absence of tmj disc displacement (28).a very high significant difference in correlation between helkimo clinical dysfunction index and mri findings of tmj disc morphology, these findings were in agreement with that reported by sato et al. (29) ,saeed (25), hirata et al. (30), imanimoghaddam et al. (26). hirata et al (2007) stated that “we agree with sato et al. (29), who examined the disc position and its configuration changes. they demonstrated that, in cases of disc displacement, mandible head mobility increased with time, although its configuration did not change; consequently, there j bagh college dentistry vol. 29(2), june 2017 the value of oral diagnosis 59 would be a more anterior displacement according to its larger deformity. in our study, the more anterior position of the posterior band was associated with greater alteration of disc configuration, when compared with a more superior position of the mandible head. we suggest that the capacity to reduce is more directly related to alterations in disc shape”. references 1. rawlani shivlal, rawlanl shobha, molwani mukta, degwekar shiris, bhowle rahul, baheti rakhi. imaging modality for temporomandibular joint disorder.jdmimsu. 2013;vol.5 no.2. 2.devaraj sharmila devi,pradeep d. internal derangement of temporomandibular joint. journal of dental and medical sciences. mar. 2014; volume 13, issue 3 ver. ii. 3.rudisch a, innerhofer k, bertram s, emshoff r .magnetic resonance imaging findings of internal derangement and effusion in patients with unilateral temporomandibular joint pain. oral surg oral med oral pathol oral radiol endod. nov 2001; 92(5):566-71. 4.tasaki mm, westesson p-l, isberg,am, yan-fang r, tallents rh.classification and prevalence of temporomandibular joint disk displacement in patients and symptom-free volunteers. am j orthod dentofac orthop. 1996; 109:249. 5. piehslinger e, schimmerl s, celar a,crowley c, imhof h comparison of magnetic resonance tomography with computerized axiography in diagnosis of temporomandibular joint disorders. j oral maxillofac surg .1995; 24:13–19. 6.sonnabend e, benz c .röntgentechnik in der zahnheilkunde. urban & schwarzenberg. münchen. 1997. 7.puelacher w .funktionelle kiefergelenkschirurgie. in: schroll k, watzek g (eds) zahnärztliche chirurgie, band iii. verlag wilhelm maudrich, wien, 1998; pp 167–207. 8.schmid-schwap martina , drahanowsky wolfgang, bristela margit, kundi michael, piehslinger eva and robinson soraya. diagnosis of temporomandibular dysfunction syndrome—image quality at 1.5 and 3.0 tesla magnetic resonance imaging. eur radiol .2009; 19: 1239–1245. 9.hasan nahla mohamed ali , abdelrahman tarek elsayed ftohy. mri evaluation of tmj internal derangement: degree of anterior disc displacement correlated with other tmj soft tissue and osseous abnormalities. the egyptian journal of radiology and nuclear medicine .2014; 45, 735–744. 10.sano t, westesson pl .internal derangement related to osteoarthrosis in temporomandibular joint: increased t2 signal in the retrodiskal tissue in painful joints. oral surg oral med oral pathol oral radiol endod.1995; 79:511–516. 11.emshoff r, brandlmaier i, gerhard s, et al. magnetic resonance imaging predictors of temporomandibular joint pain. j am dent assoc. 2003;134:705-714. 12.tognini f et al. is clinical assessment valid for the diagnosis of tmj disc displacement? 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(1) ahlam t. mohammed b.d.s., m.sc. (2) abstract background: asthma is a pulmonary disorder characterized by reversible stenosis of the peripheral bronchi. this disease could affect the oral health; as a result asthmatic patients may have a higher risk of developing dental diseases. this study was conducted to evaluate the caries experience and salivary elements among asthmatic patients using ventoline inhaler. materials and methods: the study group consisted of 30 male asthmatic patients with an age range 20-24years (under ventoline inhaler). the control group includes 30 subjects matching with study group in age and gender. plaque and dmfs index were used for recording caries experience. stimulated salivary samples were collected and then salivary flow rate, s-iga and salivary elements concentrations (ca, na, k and po4) were determined. results: the mean value of dental caries (dmfs) and plaque index (pl i) were found to be higher among study group compared to control group with statistically significant difference for pl i (p<0.05), while not significant difference was observed for dmfs (p>0.05). the mean value of salivary flow rate, ca, po4 , na and k ions concentrations were found to be lower among study group compared to the control group with no statistically significant difference (p>0.05), except for ca and k ions the differences were statistically significant (p<0.05). s-iga in the study group was higher than the control group and the difference was not significant (p>0.05). conclusions: individuals with asthma have a higher caries prevalence, worse oral cleanliness and lower salivary elements compared to the control group, so a special preventive programs need to be designed for those patients. key words: caries experience, salivary immunoglobulin a, asthma. (j bagh coll dentistry 2013; 25(4):86-90). introduction asthma is one of the most common chronic diseases throughout the world and is a serious global health problem that affect people of all ages (more than three hundred million people worldwide) and accounts for 1 of every 250 deaths worldwide, when uncontrolled, asthma can affect daily life and is sometimes fatal (1). saliva has been described as the mirror of the body. in a world of soaring healthcare costs and an environment where rapid diagnosis may be critical to a positive patient outcome, saliva is emerging as a viable alternative to blood sampling (2). allergic patients were found to have a higher caries-experience in comparison to their controls (3), which may be due to the reduction in salivary flow rate among those patients (4,5). yet no pervious iraqi study was found regarding the relation between s-iga with oral diseases among asthmatic patients. so this study was carried out to investigate the effects of asthma on the caries experience and results obtained may call the physician’s attention to the possibility of dental side effects associated with asthma and medication used in treatment as well as the dentist's attention to develop intensified preventive measures for those patients. (1) m. sc. student. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. materials and methods the sample included a study group of 30 male asthmatic patients with an age range (20-24) years under ventolin inhaler and a control group of 30 healthy looking subjects matching in age and gender. each participant was submitted to an oral examination at the dental clinic under standardized conditions according to the basic methods of oral health surveys of the who, 1997(6). general information's were recorded prior the examination included name, age, area of residency and duration of inhaler use. diagnoses of dental caries by dmfs index according to the criteria of who (6) and plaque index of silness and loe (7) were performed. stimulated salivary samples were collected under standard condition and following instruction cited by tenovuo and lagerlof (8). each salivary sample was centrifuged at 3500 r.p.m for 15 minutes. the clear supernatant was separated by micropipette and placed in sterile plastic eppendorff tubes (1 ml), then stored and frozen at -20 ºc. the salivary flow rate calculated (to be expressed by ml/min) as the volume of the collected sample divided by the time required for collection. s-iga was determined by elisa (9) and salivary elements concentrations ca, na and k and were determined by flame photometry (10), while po4 was determined by spectrophotometer (11). data processing and analysis were carried out using spss package version 17, student's t-test and pearson correlation coefficients were applied. j bagh college dentistry vol. 25(4), december 2013 caries experience pedodontics, orthodontics and preventive dentistry87 the confidence limit was accepted at 95% (p<0.05). results table 1 demonstrates that the mean value of dental caries (dmfs) and plaque index (pl i) were found to be higher among study group compared to control group with statistically significant difference for pl i while not significant difference was observed for dmfs. as shown in table 2 the salivary flow rate, ca, po4 , na and k ions concentrations were found to be lower among asthmatic patients, with no statistically significant difference, except for ca and k ions the differences were statistically significant. while siga in the study group was higher than the control group and the difference was not significant. in the study group, weak negative non significant correlations between dmfs and (flow rate, po4 , na and k ions) and weak positive non significant correlations with ca, while for s-iga there was a weak positive significant correlations. in the control group, weak positive non significant correlations were found between dmfs and (ca and s-iga), and weak negative non significant correlations with (flow rate, po4 , na and k ions) (table 3). for pl index a weak negative non significant correlations were observed with (flow rate, ca, na, k and s-iga) while weak positive non significant correlations was observed with po4 in study group. regarding the control group ,weak negative non significant correlations were observed with (flow rate, po4, na, k and s-iga) while a significant weak positive correlation was present with ca (table 4). table 5 demonstrates a significant weak negative correlation between the duration of drug intake and (na, ca and k ions) and significant weak positive correlation with po4,while non significant weak positive correlations were observed with (s-iga, pl i and dmfs) and non significant weak negative correlation was observed with flow rate. discussion the present study was found a higher dmfs values among asthmatic patients compared to control group, although the difference was statistically not significant. this difference in caries prevalence was in agreement with several studies (3,12-15). while opposite results were found by other studies (16-18). mcderra et al (12) explains the increased caries incidence among asthmatic patients with the negative influence of the inhaled drugs on salivary quantity and functions, and with increased plaque quantity. in addition, the reduction in flow rate among asthmatic patients has been linked to the higher frequency of mouth breathing, this could explain the result of this study as weak negative correlation coefficient between salivary flow rate and caries experience was found among both groups although it was not significant. this study also revealed the presence of a weak positive non significant correlation coefficient between calcium and caries experience among both groups, also revealed presence of weak negative non significant correlation between phosphate and caries experience. electrolytes in saliva especially calcium and phosphorus are necessary to maintain the integrity of teeth and considered to be an important variables explaining the difference in caries-experience, also phosphate is the main buffer in unstimulated saliva (19,20). so the negative correlation of phosphate with caries experience may be the reason of higher dmfs among asthmatic patients, also weak negative non significant correlation coefficient was found between potassium and caries experience among both groups. this in lines with other studies (21-23), but disagree with the others (24,25). a weak negative correlation was found between sodium and caries experience among both groups, although these correlations were not significant, this result coincide with previous studies (20,22,23). the role of sodium and potassium in relation to dental caries is not well substantiated as some studies recorded either a presence of a negative, positive or no correlation with dental caries at all (27-29). the present study was the first study in iraq that concerned with the measurement of s-iga in asthmatic patients. the role of s-iga in the development of dental caries is determined by the ability of such antibodies to impede plaque microorganisms’ colonization on the enamel surface by selective connection. thus they oppose all other mechanisms of microbe adhesion and interfere during formation of plaque biofilm (30). the present study revealed that there was a weak positive significant correlation between s-iga and caries experience in the study group, while weak positive non significant correlations in the control group between s-iga and caries experience. this result disagrees with rashkova et al (31) who found no dependence between the secretory immunity and dental caries in asthmatic children. the pl was higher in asthmatic than control group. there is a significant difference observed for the pl i between asthmatics and control group. dental plaque is considered the main etiological factors for gingivitis (32). the present study also showed a weak negative non significant correlation between pl i and salivary flow rate j bagh college dentistry vol. 25(4), december 2013 caries experience pedodontics, orthodontics and preventive dentistry88 among both groups. the higher frequency of mouth breathing, as well as various immunological factors in asthmatics has been linked to more plaque in both children and adults with asthma (21,33). however, weak negative non significant correlations were found between pl i with sodium and potassium among both groups. statistically, a significant weak positive correlation was present only with calcium in the control group, while a weak negative non significant correlation between pl i and calcium in study group, this is in line with ryberg et al (34) who reported decreased levels of calcium in stimulated saliva. s-iga in the present study showed a weak negative non significant correlation with pl i in asthmatic group, this in disagreement with other investigation which found that secretory immunity does not influence plaque accumulation and periodontal health (31). saliva through its flow rate and constituents play an essential role in maintaining the integrity of soft and hard tissues in the oral cavity (35). salivary flow rate may be affected by asthmatic medication (ventolin inhaler) and this may be attributed to the adrenergic effect of this drug that stimulates the sympathetic nervous system causing a reduction in salivary flow rate (34). the present study revealed a reduction in flow rate among study groups compared to the control one, however the difference was statistically not significant. studies found statistically significant difference in saliva secretion between asthmatics and controls (13,15,35), while ghulam (17) found no significant difference in saliva secretion between individuals with asthma and healthy individuals. salivary constituents concentration (na, po4, ca and k) were found to be lower in asthmatic compared to the control one but with no statistical significant difference, except for ca and k ions the difference were statistically significant. as reduced salivary flow is accompanied by concomitant decreased in salivary constituents, it is not unlikely that this particular change among asthmatic people may be one of the major contributing factors in the noted increased dental caries (34).previous iraqi study (17) found a slightly lower salivary calcium but with higher phosphate ions concentration among asthmatic patients. it is clear that s-iga plays an important role in oral homeostasis and it is an important indicator of the defensive status of the oral cavity, where the oral microbiota has antigenic potential and can stimulate secretory antibodies (36). in the present study s-iga in study group was higher than control group but with no significant difference, this result agree with rashkova et al (31) and disagree with study by seemann et al (37) that showed a reduction of s-iga level in saliva of asthmatic patients. significant weak negative correlations were observed between the duration of drug intake and (na, ca and k), while significant weak positive correlation was observed with po4. weak negative non-significant correlations were observed between the duration of drug intake and s-iga. this result is in agreement with study by ryberg et al (34) as they found an impaired level of total protein, lysozyme, s-iga and potassium after inhalation with b2-agonists in the saliva of asthmatic individuals. while weak positive non significant correlations was observed between the duration of drug intake with pl i. ghulam(17) also reported a positive correlation between the duration of drug intake and gingival index but it was not significant. however, the chronic treatment with b2-agonist may increase dental plaque, as it cause alteration in salivary protein of amylase and lower the output/min of the antibacterial components, these favors both colonization and plaque growth (36). weak positive non significant correlation was observed between the duration of drug intake and dmfs. this is in the line with milano et al (38) where they found a significant relationship between increased frequency of asthma medication and incidence of dental caries. weak negative non significant correlation was observed between the duration of drug intake and salivary flow rate. this is in line with ersin et al (4) was they found negative correlation between increased frequency of asthma medication and flow rate. references 1. mcdaniel m, paxson c, waldfogel j. racial disparities in childhood asthma in the united states: evidence from the national health interview survey, 1997 to 2003, pediatrics, 2006. 2. farnaud s, kosti o, getting j, renshaw d. saliva: physiology and diagnostic potential in health and disease. the scientific world j 2010; 10:434-56. 3. matti is. oral health status among patients with respiratory tract allergies. master thesis, college of dentistry, university of baghdad, 2000. 4. ersin n, gu¨ len f, eronat n, et al. oral and dental manifestations of young asthmatics related to medication, severity and duration of condition. pediatr int 2006; 48:549-54. 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(eds). textbook of clinical cariology. 2nd ed, copenhagen: munksgaard; 1994. 9. heiddis b, arthur a. psychosocial factors and secretory immunoglobulin a. critical reviews in oral biology and medicine 1997; 8: 461-74. 10. annino js, giese rw. flame photometry. in: clinical chemistry. principles and procedures. 4th ed. little brown and company boston press; 1976: 61. 11. hohenwallner w, wimmer e. determinants of phosphorus. clin chem acta 1973; 45: 169. 12. mcderra ej, pollard ma, curzon me. the dental status of asthmatic british school children. pediatr dent 1998; 20: 2817. 13. laurikainen k. asthma and oral health, a clinical and epidemiological studies. school of public health, university of tempere, finland, 2002. 14. farsi n. dental caries in relation to salivary factors in saudi population groups. j contemp dent pract 2008; 9(3):16-23. 15. stensson m. oral health in young people with asthma. ph.d. thesis department of cariology, institute of odontology at sahlgrenska academy, university of gothenburg, 2010. 16. meldrum a, thomson w, drummond b, sears m. is asthma a risk factor for dental caries? finding from a cohort study. caries res 2001; 35: 235-9. 17. ghulam i. oral health status in relation to salivary variables among a group of asthmatic patients. master thesis, college of dentistry, university of baghdad, 2007. 18. al-saud r. dental caries among asthmatic children aged 5-10 years old in riyadh, saudi arabia. a master thesis, college of dentistry, university of king saud, 2010. 19. edgar m, higham s. saliva and control of plaque ph. in saliva and oral health. london: british dental association, 1996. 20. de almeida p, gregio a m, machado m, de lima a, azevedo l. j contemp dent prac 2008; 9(3): 72-80. 21. shashikiran n, reddy v, raju p. effect of antiasthmatic medication on dental disease: dental caries and periodontal disease. j indian soc pedod prev dent 2007; 25:65-8. 22. abou el-yazeed m, taha s, elshehaby f, salem g. relationship between salivary composition and dental caries among a group of egyptian down syndrome children. aust j basic and appl sci 2009; 3(2):720730. 23. benghasheer h, hussein a, abu hassan m. salivary sodium and potassium in relation to dental caries in a group of multiracial school children. e-journal dent 2013; 3(1): 307-13. 24. dodds m, johnson d, mobley c, hattaway k. parotid saliva protein profiles in caries-free and caries active adults. oral surg oral med oral pathol oral radiol endod j 1997; 83(2): 244-51. 25. karagul b, yarat a, tanbonga i. a study of some salivary elements with respect to sex, age and caries in children. saud dent j 1998; 8:191-8. 26. zahir s, sarkar s. study of trace elements in mixed saliva of caries free and caries active children. j indian soc ped prev dent 2006; 24(1): 27-9. 27. el-samarrai s. major and trace elements contents of permanent teeth and saliva among a group of adolescents in relation to dental caries, gingivitis and mutans streptococci (in vitro and in vivo study). ph. d. thesis, college of dentistry, university of baghdad, 2001. 28. hiraishi n, tanaka m, takagi y. the relationship between inorganic ion composition of saliva and dental caries prevalence in children. kokubyo gakkai zasshi 2006; 66(3): 249-53. 29. radhi n. oral health status in relation to nutritional analysis and salivary constituents among a group of children with down syndrome in comparison to normal children. ph.d. thesis, college of dentistry, university of baghdad, 2009. 30. marcotte h, lavoie c. oral microbial ecology and the role of salivary immunoglobulin a. microbiol mol biol rev 1998; 62(1): 71-109. 31. rashkova m, baleva m, peneva m, toneva n, jegova g. s-iga and dental caries of children with different diseases and conditions influencing oral medium. j of imab annual proceeding 2009. 32. shulman j, nunn m, taylor s, rivera f. the prevalence of periodontal-related changes in adolescents with asthma: results of the third annual national health and nutrition examination survey. pediatric dentistry 2003; 25(3): 279-84. 33. bejkeborn, dahllof g, hedin g, lindell m, modeer t. effect of disease severity and pharmacotherapy of asthma on oral health in asthmatic children. scand j dent res 1987; 95:159-64. 34. ryberg m, moller c, ericson t. saliva composition and caries development in asthmatic patients treated with b2adrenoceptor agonists: a 4-year follow-up study. scand j dent res 1991; 99(3): 212-8. 35. puy c. the role of saliva in maintaining oral health and as an aid to diagnosis. med oral patol oral cir bucal 2006; 11: 449-55. 36. bernimoulin j. recent concepts in plaque formation. j clinical periodontol 2003; 30(5): 7-9. 37. seemann r, hagewald s, sztankay v, drews j, bizhang m, kage a. levels of parotid and submandibular and sublingual salivary iga in response to experimental gingivitis in humans. clinical oral investigations 2004; 8: 233-37. 38. milano m, lee jy, donovan k, chen jw. a crosssectional study of medication-related factors and caries experience in asthmatic children. pediatr dent 2006; 28(5): 415-9. (ivsl) table 1: dmfs and pl i indices among study and control groups. indices study group control group t-value p-value mean ±sd mean ±sd dmfs 6.10 5.72 5.93 4.54 0.12 0.89 pl i 1.08 0.20 0.95 0.26 2.12* 0.03 * significant (p<0.05) j bagh college dentistry vol. 25(4), december 2013 caries experience pedodontics, orthodontics and preventive dentistry90 table 2: salivary variables among study and control groups. salivary variables study group control group t-value p-value mean ±sd mean ±sd flow rate (ml\min) 0.90 0.12 0.95 0.14 1.37 0.17 calcium (mmol/l) 1.70 0.48 1.93 0.36 -2.10* 0.03 phosphate (mmol/l) 4.94 1.83 5.27 1.19 -0.82 0.41 sodium (mmol/l) 11.46 3.16 12.49 3.94 -1.11 0.26 potassium (mmol/l) 14.55 2.23 15.77 1.72 -2.38* 0.02 s-iga (mg/ml) 63.82 28.63 62.37 21.78 0.06 0.94 * significant (p<0.05) table 3: correlation coefficient between caries experience and salivary variables among study and control groups. salivary variable study group control group r p r p flow rate (ml\min) -0.24 0.19 -0.07 0.68 calcium (mmol/l) 0.22 0.22 0.03 0.83 phosphate (mmol/l) -0.11 0.53 -0.19 0.29 sodium (mmol/l) -0.19 0.29 -0.15 0.42 potassium (mmol/l) -0.16 0.38 -0.01 0.95 s-iga (mg/ml) 0.37* 0.03 0.08 0.67 * significant (p<0.05) table 4: correlation coefficient between pl i and salivary variables. salivary variable study group control group r p r p flow rate (ml\min) -0.13 0.48 -0.10 0.57 ca (mmol/l) -0.04 0.81 0.42* 0.01 po4 (mmol/l) 0.14 0.43 -0.11 0.54 na (mmol/l) -0.04 0.81 -0.24 0.19 k (mmol/l) -0.002 0.99 -0.25 0.17 s-iga (mg/ml) -0.08 0.67 -0.07 0.67 * significant (p<0.05) table 5: correlation coefficient between duration of inhaler intake and other variables. variable r p flow rate -0.23 0.22 ca -0.44* 0.01 po4 0.36* 0.04 na -0.37* 0.03 k -0.39* 0.03 s-iga 0.21 0.24 dmfs 0.17 0.35 pl i 0.05 0.78 * significant (p<0.05) microsoft word 1manal 1-6 f.doc j bagh college dentistry vol. 29(2) june 2016 effects of two different restorative dentistry 1 effects of two different colorant solutions on the color stability of bleached enamel in association with cppacpf: an in vitro study manal hussain abd-alla, b.d.s., m.sc., ph.d. (1) abstract background: one of the drawbacks of vital teeth bleaching is color stability. the aim of the present study was to evaluate the effects of tea and tomato sauce on the color stability of bleached enamel in association with the application of mi paste plus (cpp-acpf). materials and methods: sixty enamel samples were bleached with 10% carbamide peroxide for two weeks then divided into three groups (a, b and c) of 20 samples each. after bleaching, the samples of each group were subdivided into two subgroups (n=10). while subgroups a1, b1 and c1 were kept in distilled water, a2, b2, and c2 were treated with mi paste plus. then, the samples were immersed in different solutions as follow: a1 and a2 in distilled water (control); b1 and b2 in black tea; and c1 and c2 in tomato sauce for half an hour/day for seven days. using a colorimeter, teeth color measurements were recorded at baseline, after bleaching, staining, and polishing. color changes were recorded according to the vita shade guide and the cie lab system. student's t-test was used to analyze differences between the subgroups at p<0.05. results: significant color changes were recorded for the tea group after staining, but not after polishing (p<0.05). no significant differences in color measurements were recorded between the subgroups of each group at all periods (p>0.05). conclusion: only tea produced clinically perceivable color change of bleached enamel after staining as well as after polishing. mi paste plus did not affect enamel color change for all the groups. key wards: carbamide peroxide, staining affinity, mi paste plus, colorimeter. . (j bagh coll dentistry 2017; 29(2):1-6) introduction at-home vital tooth bleaching technique has become widely under focus as it has proven to be effective in improving the color of discolored teeth. using 10% carbamide peroxide (cp) bleaching agent in a mouth guard for two weeks has been addressed to be more effective in whitening vital teeth compared with other bleaching techniques (1). however, teeth bleaching has shown some drawbacks and one of which is the regression of teeth whitening after bleaching (1,2). this color regression has not been fully understood. patients have been advised to follow some precaution measures in order to minimize this phenomenon. clinicians have suggested that during and after the bleaching regimen, patients need not to consume darkly colored foods and drinks. several researchers have evaluated the effect of different colored food materials such as: coffee, tea, cola, red wine, and dark colored fruits on the staining susceptibility of bleached teeth during and after the bleaching procedure (3-5). cortes et al. in 2013 (3) and matis et al. in 2015 (4) showed that during the bleaching treatment, consuming dark drinks such as coffee, tea, cola and red wine could not minimize the effect of teeth bleaching. (1) lecturer, department of conservative dentistry, college of dentistry, al-mustansiriya university. e-mail: manaer11@yahoo.com however, karadas and seven in 2014 addressed that after bleaching, tooth color restaining is significantly increased with red wine, cola, and tea solutions (5). cortes et al. concluded that after bleaching red wine can produce more color changes than coffee (3). several researchers have reported the association of bleaching agents with changes in the properties of enamel such as; surface porosity and irregularities, decreasing microhardness, and demineralization (6-9). these changes have been suspected to cause increasing in dye accumulation into bleached tooth surface. clinicians have advised their patients to resume normal habits of consuming colored foods and drinks after the first 24-48 hours of bleaching. they have assumed that after bleaching the absorption and precipitation of calcium and phosphate from saliva can compensate some of those micro structure defects, and hence reducing the staining absorption of bleached teeth (10). on the other hand, several in vitro studies have supported the positive effects of fluoride and/or casein phosphopeptide-amorphous calcium phosphate (cpp-acp) on eroded and demineralized teeth surfaces (11,12). treatment of bleached tooth surface with such agents can be also promising in decreasing bleaching agents' related adverse changes (7-9,13). until recently, few researchers have studied the effect of cpp-acp (tooth mousse) or cppacpf (mi paste plus, which contains 10% cppj bagh college dentistry vol. 29(2) june 2016 effects of two different restorative dentistry 2 acp and 0.2% naf) on enamel staining susceptibility after bleaching (10,14). while singh et al. evaluated the effects of cpp-acp or fluoride on tea stain absorption after 24 hours of at-home bleaching (10), imamura et al. used cpp-acpf after in-office bleaching (14). however, evidence based facts on the staining susceptibility of bleached enamel after bleaching are still insufficient. therefore, the purpose of the present study was to investigate the effects of two different colorant dietary solutions (black tea and tomato sauce) on the enamel staining susceptibility after bleaching with 10% cp athome bleaching agent. in addition, evaluate the effect of mi paste plus (cpp-acpf) on enamel staining susceptibility after bleaching. thus, the null hypotheses tested in the present study were: 1) no color change can be seen when bleached enamel is immersed in black tea or tomato sauce and 2) surface treatment of bleached enamel with cppacpf can produce no effect on its staining affinity to black tea or tomato sauce. materials and methods this study was approved by the ethics committee of the related university. upon approval, 30 human premolars, extracted for orthodontic reasons, were collected. the teeth were cleaned of gross debris and polished with pumice. the teeth were divided into three groups (a, b and c) of ten teeth each. the roots of all the selected teeth were cut about 1mm below the cemento-enamel junction. then, the crowns of the teeth were sectioned mesiodistally into 2 halves to produce 20 buccal and lingual enamel samples for each group. the samples were mounted in plastic moulds with chemically cured acrylic resin, with the enamel surface facing upward. all the samples were bleached with a 10 % cp at-home bleaching agent (opalescence pf, ultradent products, usa). the bleaching gel was applied on each sample for 8 hours/day. after daily bleaching, each sample was rinsed under running water for 10 seconds and stored in distilled water at room temperature for the rest of the day. this procedure was repeated for 14 consecutive days. after 24 hours of the bleaching treatment, the samples of all the three groups were subdivided into two subgroups (n=10). subgroups a1, b1 and c1 were stored in distilled water at room temperature. subgroups a2, b2 and c2 were treated with casein phosphopeptide-amorphous calcium phosphate fluoride (cpp-acpf; gc mi paste plus, ultradent products inc.). about 1 mm thick of the paste was applied with a microbrush on the enamel surface and left for half an hour. then, the paste was wiped off with damped gauze and the samples were stored in distilled water for the rest of the day. the application of the paste was repeated for three consecutive days. staining procedure during the staining period, the samples of group a (a1 and a2) were stored in distilled water as control. the staining procedure was performed for group b and c after 24 hours from the last surface treatment with cpp-acpf. two types of colorant solutions were used to stain the samples of group b and c; black tea and tomato sauce as follow: b1 and b2 were immersed in black tea and c1 and c2 were socked in tomato sauce. tea solution was prepared by boiling 2 g of black tea (ceylon tea, akbar brothers, colombo 10, sri lanka) in 100 ml of distilled water for five minutes. the solution was then filtered to remove the tea from the infusion. tomato sauce solution was prepared by boiling one full table spoon of tomato paste (altunsa, altunkaya ins, beylerbeyi-gaziantep, turkey) in 100 ml of distilled water for five minutes. the ph of the tea and tomato sauce solutions was 5.95 and 4.98, respectively. the samples in each group were immersed in their corresponding solutions for half an hour/day. after the staining period, the samples were washed under running water for 10 seconds and kept in distilled water at room temperature for the rest of the day. this procedure was repeated with fresh staining solutions for seven consecutive days. after 24 hours, all samples were polished for 10 seconds each with a rubber cup in a lowspeed hand piece and pumice to remove any extrinsic stains. teeth color measurements the color measurements were adopted objectively using a colorimeter (vita easy shade, zahnfabrik; h. rauter gmbh and co, kg, bad sackingen, germany). the measurements were performed for all the subgroups at four periods: at the baseline (t0), by the end of the 2 weeks bleaching period (t1), after 24 hours of the staining procedure (t2) and after polishing (t3). to ensure a standard sample spot measurement by the colorimeter, a custom-fabricated positioning template was fabricated for all the samples with a polyvinyl silicone putty material (zetaplus, zhermack, rovigo, italy). each template had a 6 mm diameter spot facing the center of each sample for positioning the colorimeter tip. the color measurements were evaluated according to the vita classical shade guide j bagh college dentistry vol. 29(2) june 2016 effects of two different restorative dentistry 3 provided by the colorimeter and in reference to the cie l*a*b* parameters established by the commission international de l´eclairage in 1976 (15). according to vita shade guide tabs, the tabs are arranged from the lightest with their corresponding values starting from (b1=1) to the darkest (c4=16) as represented in table 1. table 1: numerical values of vita classic shade guide tabs (sgt) based on the cie l*a*b* color system, the color of an object is located in a threedimensional color space. the coordinate l*, representing the lightness; a*, represents shade and saturation in the green-red axis; and b*, represents saturation in the blue-yellow axis. color differences (δl*, δa*, and δb*) were calculated between the records after polishing (t3) and after bleaching (t1). total color difference (δe*) was calculated at two different periods using the following equation (15): δe*1 was calculated between the records after bleaching (t1) and after staining (t2), while δe*2 between after bleaching measurements (t1) and after polishing (t3). the results were analyzed using spss program (spss 19.0 for windows). one-way anova and post hoc tests were used to evaluate differences among the groups. student's t-test was used to analyze differences between the subgroups at p<0.05. results mean values of vita shade guide at the four measuring periods were represented in figure 1. no significant differences were recorded among the mean values of the shade guide at t0, t1 or t3 (p>0.05). however, at t2 significant differences were seen between both subgroups of group b compared with the other four subgroups (p<0.05). no significant differences were recorded between the subgroups of each of the three groups (p>0.05). figure 1: mean values of vita shade guide for all subgroups at baseline (t0), after bleaching (t1) after staining (t2) and after polishing (t3). table 2 presents the means (sd) of δl*, δa*, and δb* for all groups. significant differences in δa* were seen between the subgroups of the control and those of group c. table 2: means (sd) of δl*, δa*, and δb* for all groups groups mean(sd) δl* mean(sd) δa* mean(sd) δb* a1 -1.74 (1.95) 1.09 (0.95) -0.52 (2.50) a2 -1.31 (2.36) 0.23 ab (0.91) -1.53 (2.02) b1 -2.07 (2.33) 0.22 cd (0.91) -2.90 ab (3.28) b2 -1.15 (2.40) 0.62 (1.28) -1.47 (3.66) c1 -0.76 (1.78) 1.01 ac (0.63) -0.20 a (2.17) c2 -0.57 (1.41) 1.13 bd (0.66) -0.45 b (1.64) values with the same letters are significantly different at p<0.05 table 3 presents the means (sd) of δe*1 and δe*2 for all subgroups. mean values of δe*1 showed significant differences between the subgroups of group b with the subgroups of group a and c (p<0.05). however, no significant differences were recorded between the subgroups of group c and those of group a (p>0.05). mean values of δe*2 for both group b and c showed no significant differences compared with the control group (p>0.05). neither δe*1 nor δe*2 showed any significant differences between the subgroups of all of the three groups (p>0.05). sgt value sgt value b1 1 a3 9 a1 2 d3 10 b2 3 b3 11 d1 4 a3.5 12 a2 5 b4 13 c1 6 c3 14 c2 7 a4 15 d2 8 c4 16 j bagh college dentistry vol. 29(2) june 2016 effects of two different restorative dentistry 4 table 3: means (sd) of δe*1 and δe*2 for all subgroups groups mean (sd) δe*1 mean(sd) δe*2 a1 3.30 (1.49)ab 3.36(1.84) a2 3.40(1.90) cd 3.26(1.81) b1 7.71(2.47)acef 4.92(2.08) ab b2 7.78(2.97 )bdgh 4.21(2.34)c c1 2.12(2.21) eg 2.70(1.41)a c2 2.60(2.60) fh 2.35(.99)bc values with the same letters are significantly different at p<0.05 discussion at-home bleaching technique with 10% cp has been accepted by the american dental association (ada) assuring its safety and effectiveness (16). however, teeth whitening stability after bleaching treatment is still a concern. researchers have evaluated the effect of different colorant drinks such as; tea, coffee, cola, etc., on bleached enamel during and after bleaching. it has been reported that after bleaching, different colored diets may cause significant color changes (3,5,9). the two staining solutions used in the present study were selected as they are most commonly consumed in the middle east countries. while black tea is a very popular beverage consumed on a daily basis, tomato sauce is regularly used as an indispensable food ingredient in each cuisine. and the staining time used (half an hour a day) was to simulate the time and frequency of consumption of these materials during the day. in the present study, the recorded color differences in δl*, δa*, and δb* after polishing, showed significant difference in δa* between the subgroups of the control and only for those of tomato sauce. however, no significant changes for δl* nor δb* were recorded between all groups. it has been reported that color change produced by bleaching procedure is more related to δl* and δb* parameters than δa*. besides, δa* is very small compared with δl* and δb* which could be the reason for the different results of the studies performed under different protocols (17). interpretation of color change between different groups using δe* gives a more meaningful value than the other three color parameters (18). according to the results of the present study, after staining with tea both δe*1 and vita shade guide values for both subgroups were significantly higher than those of the control. however, after polishing both δe*2 and vita shade guide values for the tea group were not significantly different from the control group. thus, the first hypothesis provided in this study should be rejected for the tea group before polishing and accepted after polishing. tea produced significant external tooth surface staining which was not significant after mechanical staining removal. on the other hand, tomato sauce group showed no significant differences neither in δe* nor in vita shade guide values before and after polishing compared with the control. therefore, for the tomato sauce group, the first null hypothesis should be accepted at both measuring periods. it is well accepted that the value of δe* is important to determine teeth color changes clinically. it has been concluded that when the value of δe* is < 1, the difference is considered to be not perceivable clinically, while when δe* is > 3.7, color change is considered as easily visible, but when δe* is between 3.7 and 1, color difference is considered clinically acceptable (19). in the present study, the values for δe* for the tea group were the highest before and after polishing (δe*>3.7). however, both the control and tomato sauce groups recorded δe*<3.7. in the present study, although tea did not produce significant difference in δe* compared with the control after polishing, its δe* value is considered clinically perceivable. such a result is in accordance with other studies reported significant color changes of bleached enamel produced by tea (5,14). in the later studies and after bleaching, increasing color change was obvious by increasing the staining periods. continued and frequent consumption of colored drinks can increase the staining susceptibility of bleached enamel (20). several studies have reported that tea has shown to have a high capacity to stain not only teeth (21) but also tooth-colored restorative materials (22) and denture base acrylic resins (23). staining has a multi-factorial etiology with chromogens derived from dietary sources. teeth color imparted is determined by the natural color of the chromogen (24). it has been reported that teeth discoloration is influenced by low ph and food color rather than the dietary pigment alone (25). in the current study, although tomato sauce was more acidic than tea (4.98 vs. 5.95), its staining affinity was less. thus, staining affinity of a staining solution is correlated to its essence chromogens rather than to its acidity. several studies have reported that after bleaching, both fluoride and cpp-acp can remineralize eroded enamel (6), and enhance tooth roughness and microhardness (8,9). on the other hand, using cpp-acpf (mi paste plus) could produce smoother enamel surface and higher level of remineralization (11,12). according to the j bagh college dentistry vol. 29(2) june 2016 effects of two different restorative dentistry 5 manufacturer, mi paste plus has not only the same benefits of regular mi paste, but also enhanced with 0.2% sodium fluoride (900 ppm) to further diminish demineralization. in the present study, surface application of cpp-acpf was intended to accommodate the assumed bleaching agents' related changes immediately after bleaching. the results of the present study showed that, no significant differences were seen between the subgroups of all of the three groups. such a result requires the acceptance of the second null hypothesis that cpp-acpf could not affect the staining absorption susceptibility for the stained groups. this result is in consistence with ley et al. (26) who recorded no significant change in δe* after severe red wine staining of bleached enamel with or without fluoride application. the results are not in accordance with those reported by singh et al. (10). this could be related to two reasons; shorter immersion period into the tea solution and the storage media used during the procedure. in the later study, they have used tea solution for only ten minutes in only two different timings (after one hour and 24 hours of bleaching). in the current study, the staining procedure was carried out for half an hour/day for seven days. imamura et al. reported that increasing the immersion time in tea, bleached enamel treated with cpp-acp can gradually re-stained (14). matis et al. (4) reported that even during bleaching, a positive but weak association between tooth whitening and diet may be produced when consuming large amounts of coffee/tea. for the storage media, researchers have used artificial saliva in in vitro studies to simulate the natural salivary function, thus less evident detrimental effects of bleaching agents may be induced during and after bleaching regimen (3,27). in the present study, the use of normal saline as a storage media was intended in order to restrict any potential effect other than that proposed to the use of cpp-acpf. cortes et al. (3) reported that during and after bleaching, enamel staining is effectively prevented by remineralization of the enamel with artificial saliva. in the present study, no significant color change difference was recorded between the subgroups of the control group. after bleaching, enamel color regression for the control group was not affected by the application of cpp-acpf. this color regression after at-home bleaching with 10% cp was also recorded by clinical studies as well as in in vitro studies (2,28). li et al. (29) reported that color regression of bleached enamel can be recorded even in mineral containing environment. further investigations are still needed to identify the influence of prolong use of other colorant food materials on teeth whitening stability. in conclusion and within the limitations of the present study, it can be concluded that: 1. black tea can produce clinically perceivable color change of bleached enamel after staining as well as after polishing. 2. tomato sauce did not affect the teeth whitening neither after staining nor after polishing. 3. mi paste plus did not influence neither teeth whitening regression nor staining susceptibility of the used colorant solutions. referrences 1. basson ra, grobler sr, kotze tj, osman y. guidelines for the selection of tooth whitening products amongst those available on the market. sadj 2013; 68(3): 122-9. 2. matis ba, cochran ma, eckert g. review of the effectiveness of various tooth whitening systems. oper dent 2009; 34(2): 230-5. 3. côrtes g, pini np, lima da, liporoni pc, munin e, ambrosano gm, aguiar fh, lovadino jr. influence of coffee and red wine on tooth color during and after bleaching. acta odontol scand 2013; 71(6): 1475-80. 4. matis ba, wang g, matis ji, cook nb, eckert gj. white diet: is it necessary during tooth whitening? oper dent 2015; 40(3): 235-40. 5. karadas m, seven n. the effect of different drinks on tooth color after home bleaching. eur j dent 2014; 8(2): 249-53. 6. yeh st, su y, lu yc, lee sy. surface changes and acid dissolution of enamel after carbamide peroxide bleach treatment. oper dent 2005; 30(4): 507-15. 7. borges bc, borges js, de melo cd, pinheiro iv, santos aj, braz r, montes ma. efficacy of a novel at-home bleaching technique with carbamide peroxide modified by cpp-acp and its effect on the microhardness of bleached enamel. oper dent 2011; 36(5): 521-8. 8. bayrak s, tunc es, sonmez is, egilmez t, ozmen b. effects of casein phosphopeptide-amorphous calcium phosphate (cpp-acp) application on enamel microhardness after bleaching. am j dent 2009; 22(6): 393-6. 9. cunha ag, de dasconcelos aa, borges bc, vitoriano jde o, alyes-junior c, machado ct, dos santos aj. efficacy of in-office bleaching techniques combined with the application of a casein phosphopeptide-amorphous calcium phosphate paste at different moments and its influence on enamel surface properties. microsc res tech 2012; 75(8): 1019-25. 10. singh rd, ram sm, shetty o, chand p, yadav r. efficacy of casein phosphopeptide-amorphous calcium phosphate to prevent stain absorption on freshly bleached enamel: an in vitro study. j conserv dent 2010; 13(2): 76-9. j bagh college dentistry vol. 29(2) june 2016 effects of two different restorative dentistry 6 11. hamba h, nikaido t, inoue g, sadr a, tagami j. effects of cpp-acp with sodium fluoride on inhibition of bovine enamel demineralization: a quantitative assessment using micro-computed tomography. j dent 2011; 39(6): 405-13. 12. srinivasan n, kavitha m, loganathan sc. comparison of the remineralization potential of cppacp and cpp-acp with 900 ppm fluoride on eroded human enamel: an in situ study. arch oral biol 2010; 55(7): 541-4. 13. de vasconcelos aa, cunha ag, borges bc, vitoriano jde o, alyes-junior c, machado ct, dos santos aj. enamel properties after tooth bleaching with hydrogen/ carbamide peroxides in association with a cpp-acp paste. acta odontol scand 2012; 70(4): 337-43. 14. imamura y, otsuki m, sadr a, tagami j. effect of cpp-acp and sodium fluoride on prevention of restaining after bleaching. asian pac j dent 2013; 13(2): 47-55. 15. commission internationale de l’eclairage. colorimetry. publication no.15 1976, supplement no.15. 16. council on scientific affairs 2006. acceptance program guidelines: dentist dispensed home-use tooth bleaching products. chicago il american dental association. 17. polydorou o, hellwig e, hahn p.the efficacy of three different in-office bleaching systems and their effect on enamel microhardness. oper dent 2008; 33(5): 579-86. 18. yannikakis sa, zissis aj, polyzois gl, caroni c. color stability of provisional resin restorative materials. j prosthet dent 1998; 80(5): 533-9. 19. johnston wm, kao ec. assessment of appearance match by visual observation and clinical colorimetry. j dent res 1989; 68(5): 819-22. 20. bazzi jz, bindo mj, rached rn, mazur rf, vieira s, de souza em. the effect of at-home bleaching and toothbrushing on removal of coffee and cigarette smoke stains and color stability of enamel. j am dent assoc 2012; 143(5):1-7. 21. attin t, manolakis a, buchalla w, hannig c. influence of tea on intrinsic colour of previously bleached enamel. j oral rehabil 2003; 30(5): 488-94. 22. tekce n, tuncer s, demirci m, serim me, baydemir c. the effect of different drinks on the color stability of different restorative materials after one month. restor dent endod 2015; 40(4): 255-61. 23. imirzalioglu p, karacaer o, yilmaz b, ozmen msc. color stability of denture acrylic resins and a soft lining material against tea, coffee, and nicotine. j prosthodont 2010; 19(2): 118-24. 24. watts a, addy m. tooth discoloration and staining: a review of the literature. br dent j 2001; 190(6): 30916. 25. azer ss, hague al, johnston wm. effect of ph on tooth discoloration from food colorant in vitro. j dent 2010; 38(2): 106-9. 26. ley m, wagner t, bizhang m. the effect of different fluoridation methods on the red wine staining potential on intensively bleached enamel in vitro. am j dent 2006; 19(2): 80-4. 27. de freitas pm, basting rt, rodrigues ja, serra mc. effects of two 10% peroxide carbamide bleaching agents on dentin microhardness at different time intervals. quintessence int 2002; 33(5): 370-5. 28. burrows s. a review of the efficacy of tooth bleaching. dent update 2009; 36(9):537-8. 29. li q, xu bt, li r, yu h, wang yn. quantitative evaluation of colour regression and mineral content change of bleached teeth. j dent 2010; 38(3): 253-60. المستخلص یتي لالسنان الحیة ھي واحدة من معوقات ھذا النوع من العالج. الھدف من الدراسة الحالیة ھو تقییم تاثیر الشاي اھداف البحث: عدم استقرار تبییض مینا االسنان بعد استخدام التبییض الب .mi paste plusنان بالترافق مع استخدام مادة وصلصة الطماطم على ثبات التبییض لمینا االس نان تم تبییضھا لمدة اسبوعین باستخدام تون عینة من مینا االس ,a مجموعات من عشرین عینھ لكل مجموعھ (ِ 3كاربومید البیروكساید ثم تم تقسییم العینات الى %10طریقة العمل: س b and c حیث تم خزن ). بعد التبییض, كل مجموعة قسمت الى جزئین(a1, b1 and c1) في الماء المقطراما الجزء االخر (a2, b2, and c2) تم معاملتھا بمادة mi paste plus) ثم وضعت عینات المجموعة االولى .a) ثانیة في محلول صلصة الطماطم لنصف ساعة (c)في الشاي والمجموعھ الثالثة b)) في الماء المقطر والمجموعھ ال یاس التغیر باللون للعینات باستخدام مقیاس االلوان وذلك قبل التبییض, بعد التبییض, بعد التلوی تالیة. تم ق یرا بعد التلمیع. التغیر باللون تم یومیا ولمدة سبعة ایام مت ن بالسوائل الملونھ, واخ یا بین المجموعات الثالث بقسمیھا باعتماد قیمة cie lab system وایضا vita shade guideقیاسھ اعتمادا على . p<0.05. تم تحلیل االختالفات احصائ یع (p<0.05)النتائج: تم تسجیل اختالف مؤثر بین العینات التي عوملت بالشاي ولكن لیس بعد عملیة تلمیعھا . لم یسجل اي فرق بین قسمي اي مجموعة من المجموعات الثالث في جم القراءات. لم تؤثر على عملیة التلون لجمیع المجموعات. mi paste plusاالستنتاجات: محلول الشاي سبب تائیرا ملحوظا على لون مینا االسنان المبیضة بعد التلون بالسائل. مادة , جھازقیاس االلوان.mi paste plus: كاربومید البیروكساید, المیل للتلون, المفتاحیة لكلماتا j bagh college dentistry vol. 33(3), september 2021 effect of plasma 9 effect of plasma treatment on the bond of soft denture liner to conventional and high impact acrylic denture materials lubna m. qanber (1), thekra i. hamad (2) https://doi.org/10.26477/jbcd.v33i3.2948 abstract background: the main drawback of soft lining materials was that they debonded from the denture base after a certain period of usage. therefore, the purpose of this research was to determine the impact of oxygen and argon plasma treatment on the shear bonding strength of soft liners to two different kinds of denture base materials: conventional acrylic resin and high impact acrylic resin. materials and methods: heat cure conventional and high impact acrylic blocks (40 for each group) were prepared. a soft liner connected the final test specimen of two blocks of each acrylic material. shear bond strength (sbs) was assessed using universal testing machine. additional blocks were also prepared for analyzing vickers microhardness, contact angle, ftir and afm. the results were statistically analyzed using paired-sample t-test and independent-samples t-test (α=0.05). results: the results showed a highly significant increase in sbs following plasma treatment with the highest mean value observed in plasma treated high impact acrylic specimen. along with a significant rise in wettability, while microhardness was preserved. conclusion: in conclusion, oxygen and argon plasma treatment was significantly effective in enhancing the sbs between soft liner and acrylic materials. keywords: plasma treatment, high impact acrylic, shear bond strength, microhardness, soft liner. (received: 1/6/2021, accepted: 4/7/2021) introduction acrylic resins are the most popular choice for fabricating denture bases due to their ease of processing, low cost, and aesthetic appeal.(1) the high frequency of fractures necessitated the need of methods for enhancing fracture resistance of denture bases. high impact strength acrylic was developed for this purpose.(2) chemical modification of acrylic resin by incorporating rubber in the form of butadiene styrene has been proved effective in terms of enhancing fracture resistance and impact strength of the denture bases against unexpected high forces.(3) while retention is critical for a good denture over time, dentures can become ill-fitting due to residual ridge resorption causing discomfort and pain to the patient.(4) this issue can be addressed by the use of resilient denture liners. soft liners provide cushioning effect assisting in the distribution and reduction of the functional forces, as well as helping the tissue in recovering from trauma giving comfort to the patient.(5) (1) master student, health department of najaf al mishkab section, iraq. (2) professor, department of prosthodontics, college of dentistry, university of baghdad. corresponding author, lubnaqanber@gmail.com soft liners serve in restoring the fit of the denture base in a variety of other clinical situations, including dentures that oppose natural dentition, xerostomia, and bony undercuts.(6) however, they suffer from a serious shortcoming, which is their debonding from the denture base following prolonged use, which may create a favorable environment for the growth of bacteria, thereby speeding up the decomposition of the material. (7,8) various methods of surface modification have been tested out to overcome the problem of debonding between acrylic resins and soft liners. one of these methods is treating the surface with plasma.(9) plasma is made up of electrons and ions as well as neutrals, atomic and molecular species that behave collectively in the presence of an electromagnetic field.(10) it has been discovered that plasma treatment with oxygen increases the hydrophilicity of polymer surfaces, thus increasing their surface energy.(11) on the other hand, it has been reported that plasma treatment of polymers with argon gas induces polymer cross linking properties.(12) there are a variety of generally accepted measures for determining the soft liner’s mechanical properties, including tensile, peel, and shear bond strength. al-athel & jagger (1996) claimed that shear bond strength (sbs) test had the best approximation of the situation that is present in the oral cavity in terms of the direction of forces which result in debonding of soft liner.(13) https://doi.org/10.26477/jbcd.v33i3.2948 j bagh college dentistry vol. 33(3), september 2021 effect of plasma 10 therefore, the objective of this research was to study the effect of oxygen and argon plasma treatment on shear bond strength of soft liner to two types of denture base materials; conventional heat cure and high impact acrylic. the null hypothesis suggested that plasma treatment would have no positive impact on the shear bond strength. materials and methods preparation of specimens the same procedure was used to prepare test specimens for both of the acrylic materials: conventional acrylic (n=20, for each test) and high impact acrylic (n=20, for each test). twenty specimens for testing shear bond strength were prepared. each specimen consisted of two blocks with dimensions of (75 × 13 × 13 mm) length, width, thickness, respectively, with a 3 mm depth stopper.(14) one block is fixed on top of the other, leaving a gap in between for the application of the soft liner material. plastic blocks were constructed with the dimensions mentioned earlier; to be duplicated into acrylic. laboratory silicone putty (zetalabor, zhermack, italy) was used to aid in the duplication process (figure 1). the putty was prepared by mixing its base and catalyst (according to the manufacturer’s instructions, it was kneaded until it became homogenous, the plastic blocks were then invested in the silicone. after setting of the putty, the excess was sliced off a sharp knife. the final piece of putty was then inserted in stone in a regular flask. following setting of stone, the plastic block was removed leaving a space for molding acrylic material. conventional acrylic (spofadental, czech) was mixed as directed by the manufacturers; in a ratio of 2.2 g:1 ml. while high impact acrylic (vertex, netherlands) was mixed with a ratio of 2.1 g:1 ml. each acrylic was then packed in dough stage into the silicone molds, the upper and lower parts of the flask were re-assembled until edge-to-edge contact was achieved, and placed under pressure using hydraulic press (100 kpa) to ensure even distribution of the material, and left there under pressure for 5 minutes. the flask was mounted into a clamp and submerged in boiling water in a digital water-bath, the heat was maintained at 70°c for an hour and a half, then the temperature was raised to 100°c for half an hour. after bench cooling of the flask for 30 minutes, the acrylic specimens were collected, finished and polished in the regular way. to create a smooth, flat surface, the targeted treatment surface was polished using gradually finer grades (600-1200) of silicon carbide paper. a digital vernier was used to verify the size of the acrylic blocks. the blocks were then stored in plastic containers with distilled water. specimens for testing microhardness were prepared in the same way (12 × 12 × 3 mm). (15) specimens for testing wettability were also prepared (20 × 15 × 2 mm).(16) all specimens were thereafter cleaned using a 1% detergent solution (liquid soap and water) and then with distilled water in an ultrasonic cleaner for 15 minutes. after that, they were dried in the air, and immediately fixed in the sample holder inside the plasma chamber.(17) plasma treatment plasma was applied to ten specimens for each test of each group. plasma treatment was carried out with the aid of a dc-glow discharge plasma system (locally manufactured at ministry of science and technology, iraq); the apparatus was equipped with a direct current (dc). the gas utilized was a combination of oxygen and argon at a ratio of 1:1. bonding surfaces of the sbs specimens and the other test specimens were mounted on the center of the cathode surface at a right angle to the gas flow with a 4 cm distance. gas pressure was kept constant at 4 × 10-2 mbar. the plasma was excited using a dc voltage supply operating up to 650 v and a maximum dc of 30 ma. a uniform glow could be seen directed to the samples. all of the specimens were exposed to plasma for 5 minutes. at the end of plasma exposure period, the chamber was kept locked for an additional 15 minutes to allow the gas to be evacuated; the specimens were then retrieved and isolated using a cling film. preparing final sbs samples two acrylic specimens were placed facing each other for each sbs test sample, creating a gap between them measuring (13 × 13 × 3 mm) width, length, and depth, respectively. the two specimens were taped together and then fully submerged in laboratory putty (zetalabor, zhermack, italy) and left to set completely. to facilitate flasking, a flask custommade to the size of the samples was constructed. j bagh college dentistry vol. 33(3), september 2021 effect of plasma 11 the silicone containing the sample was then invested in stone inside the custom-made flask and allowed to set. following that, the samples were extracted from the silicone to remove the tape and reinserted into the silicone. heat-cure soft liner (vertex-soft, netherlands) was prepared with a mixing ratio of 1.2 g: 1 ml. once the material has reached its dough stage, with a metal mixing spatula, it was gently placed and condensed into the gap between each two blocks; the space was overfilled, the flask was then covered under pressure (1kg) and firmly screwed until edge-to-edge contact was achieved. the curing cycle was performed by heating water in a digital water bath up to 70°c for an hour and a half, then elevated up to 100°c for half an hour. following curing, the flask was removed from the water bath and was left on the bench for 30 minutes to cool down, followed by 15 minutes of cooling under running tap water to ensure complete cooling.(18) the flask was opened and the samples were extracted and finished using a sharp blade to cut any excess and then stored in a container filled with distilled water. shear bond strength test a universal testing machine (laryree technology co.ltd, china) with a load cell capacity of 100 kg and a cross head speed of 0.5 mm/min was used to perform the shear bond strength test. readings obtained from the machine represent the maximum load of failure. the machine's readings show the maximum load of failure. bond strength was calculated by dividing the greatest load of failure by the cross-section area of each sample (13 × 13 mm = 169 mm2), as recommended by astm specification d-638 (1986).(19) vickers microhardness testing a vickers microhardness tester (brinell rockwell time group inc., china) was used to carry out the vickers microhardness test. the square-base indenter was used to press a diamond indenter into the specimen surface and optically measure the diagonal length by a built-in scaled microscope. to determine the microhardness of all of the acrylic samples, they were loaded with a 30 g weight for 30 figure 1: preparing sbs acrylic specimens: a, plastic block; b, plastic blocks invested in silicone putty then in stone; c: retrieving the blocks; d, following curing of acrylic material; e, 20 pairs of conventional acrylic specimens; f, 20 pairs of high impact acrylic specimens. j bagh college dentistry vol. 33(3), september 2021 effect of plasma 12 seconds. the final number was taken as the average microhardness of the indentation measured at four points for each sample. wettability testing contact angle of the treated and untreated acrylic surfaces was measured using an optical tensiometer (tl 1000, theta lite, oneattension, biolin scientific, lichfield, uk). at room temperature, a drop of distilled water was used. in this procedure, a graduated syringe with hydrophobic needle deposits a drop; after 5 seconds the contact angle is captured with 60 images per second over 10 seconds. the images captured were analyzed using the special software of the microscope. this software drew a tangent automatically; the angle located at the threephase-lines air/solid/liquid was calculated to give the contact angle value. chemical surface analysis (ftir analysis) to gain a better understanding of the chemical surface changes that occurred on acrylic denture base materials following plasma treatment, the specimens’ surfaces were investigated using ftir analyzer (fourier transform infra-red spectrophotometer, bruker, germany). specimens with the exact measurements of wettability test specimens were prepared (20 × 15 × 2 mm). atomic force microscopy (afm) analysis atomic force microscopy was used to study the surface topography/morphology of untreated and plasma-treated acrylic polymer specimens. specimens with the same measurements of wettability test specimens (20 × 15 × 2 mm) were prepared. statistical analysis to conduct statistical analyses, statistical analysis software (ibm spss statistics 26) was used. the pair-sample t-test and independent-samples t-test were used to analyze and compare the mean values. statistical significance was considered for all comparisons when the p-value was less than 0.05. results sbs, microhardness, and contact angle findings were analyzed for the untreated and treated samples, for conventional acrylic, and high impact acrylic (table 1). comparative analysis for each group was individually performed using paired-samples t-test to determine the significance of plasma treatment effect. the results showed that sbs was significantly increased following plasma treatment (p<0.001) for acrylic of both types when compared to their respective control groups. the mean values of microhardness of regular and high impact acrylic had a non-significant change following plasma treatment (p>0.05). table 1 also shows a significant decrease of contact angle mean values after plasma table 1: comparative analyses of the mean values of sbs, microhardness and contact angle tests for conventional and high impact acrylic test group n mean standard deviation min. max. t-test df sig. conventional acrylic sbs (n/mm2) control 10 0.825 0.0891036 0.722 0.976 -28.807 9 0.000 treated 10 1.540 0.0450955 1.459 1.600 microhardness (hv) control 10 22.239 1.082707 20.46 24.18 0.075 9 0.942 treated 10 22.202 1.185962 20.44 24.26 contact angle (°) control 10 74.264 1.59953 71.23 76.65 10.547 9 0.000 treated 10 66.363 1.76196 63.46 68.36 high impact acrylic sbs (n/mm2) control 10 1.359 0.0989452 1.191 1.475 -17.799 9 0.000 treated 10 2.180 0.1142171 1.982 2.335 microhardness (hv) control 10 21.018 1.113701 19.37 23.30 1.099 9 0.300 treated 10 20.719 1.012384 19.43 22.97 contact angle (°) control 10 69.765 1.90348 66.33 72.37 17.135 9 0.000 treated 10 58.151 1.75363 55.46 60.59 j bagh college dentistry vol. 33(3), september 2021 effect of plasma 13 treatment (p<0.001), indicating a significant increase in the wettability. independent-samples t-test was used for the comparison between the readings of sbs, microhardness and wettability of the two acrylic materials, conventional and high impact acrylics (table 2). analyses of the chemical composition of the surfaces of each of the control and treated groups were performed using an ftir analyzer (figure 2). the twoand three-dimensional images obtained by the afm analysis are shown in figure 3. afm analysis of plasma treated conventional and high impact acrylic surface has shown a more uniformly distributed granular film when compared to that of their untreated surface (figure 4). average surface roughness was increased following plasma treatment for both of the acrylic materials. discussion in practical usage, soft liner materials are often subject to tearing and shear stresses, resulting in their debonding from the denture base after a period of use.(4) numerous ways of surface modification have been investigated in the literature; plasma treatment was found to greatly increase surface hydrophilicity without impairing the surface chemical characteristics.(12) as such, in the current research, the impact of oxygen and argon plasma treatment on sbs of soft liner to denture bases of two different materials was evaluated. table 2: comparison of mean values of sbs, microhardness and contact angle tests between the two groups of acrylic materials test group acrylic material t-test df sig. sbs (n/mm2) control conventional -12.685 18 0.000 high impact treated conventional -16.477 18 0.000 high impact microhardness (hv) control conventional 2.486 18 0.023 high impact treated conventional 3.008 18 0.008 high impact contact angle (°) control conventional 5.722 18 0.000 high impact treated conventional 10.446 18 0.000 high impact and ar plasma treatment: a, conventional acrylic; b, high impact acrylic. 2figure 2: ftir spectra before and after o j bagh college dentistry vol. 33(3), september 2021 effect of plasma 14 figure 3: afm twoand three-dimensional images of conventional and highs impact acrylic j bagh college dentistry vol. 33(3), september 2021 effect of plasma 15 the null hypothesis that plasma treatment does not enhance sbs was rejected, as sbs was significantly improved following plasma treatment of both conventional heat-cure acrylic and high impact acrylic. this improvement may be attributed to the fact that oxygen gas in plasma treatment promotes an etching process by chemically removing particles from the surface material. additionally, new functional groups such as o-h, c-o, and c=o are generated on the surface through the chemical oxidation reaction. it also enhances the surface energy, thereby allowing the soft liner to penetrate deeper into the irregularities,strengthening the bond between the two materials.(20) even though argon is an inert gas and inert gas plasma treatments cannot generate any new reactive functional groups onto the polymer surface, treatment of polymers with inert gases could induce formation of free radicals on the acrylic surface via ultraviolet radiation and ion bombardment.(12) furthermore, an inert gas, argon is combinedwith an active gas, such as oxygen in plasma, boosts oxygen functionality.(21) this was supported by measurements of contact angles, which showed that the contact angle of the treatment groups was substantially lower than that of the control groups. the additional polar functional groups that have been grafted onto the surface may have contributed to this reduction in contact angle. functional groups break bonds on the surface, boosting surface energy and, as a result, wettability.(22) high impact acrylic showed significantly higher sbs than conventional acrylic in the control and treated groups. this may be due to the fact that high impact acrylic initially exhibits greater surface wettability, along with the presence of rubber particles in high impact acrylic. these particles are grafted into methyl methacrylate so as to bind them well to the acrylic heat polymerizing matrix. this coincides with the findings of mittal et al. (2016), who found that the tensile bonding strength was greater between silicone-based soft liner and high impact acrylic than that with conventional acrylic.(6) for both acrylic materials, plasma treatment showed a non-significant change on microhardness, which coincides with the conclusion of dos santos et al. (2016), that there was no effect on microhardness of acrylic denture resin when treated with plasma, making it an acceptable method for surface modification when compared to other treatments.(23) the results of ftir analysis may provide an explanation for preservation of microhardness. no variation in peak positions was observed using ftir surface chemical analysis, indicating that the hybridization state and electron distribution within figure 4: bar charts illustrating granularity cumulation distribution of nanograins of the control and study groups of conventional and high impact acrylic j bagh college dentistry vol. 33(3), september 2021 effect of plasma 16 the molecular bond have remained stable. this means that plasma treatment did not affect the chemical structure of these acrylic materials, which coincides with the ftir results of mustafa’s study.(14) however, the peak intensities of the functional groups c=o, c-h, and c-o have increased, implying an increase in the amount (per unit volume) of these functional groups.(24) afm analysis of the control groups of both materials revealed that the surface granular film was distributed unevenly, when compared to that of the treated groups which showed a more even distribution along with a reduction in the average grain diameter and a rise in the number of grains. these observations indicate that plasma treatment removes the materials with lower attachment energy to the surface and diminishes the irregularities of the surface to bear polar groups.(25) these changes in surface morphology are suggested to be primarily produced by the surface being bombarded by highenergy ions present in the plasma, indicating that the phenomena of cross-linking has become enhanced.(26) the test settings may not be representative of the actual clinical situation, as the test specimens comprised many adhesive surfaces, whereas dentures have just one adhesive surface in clinical practice. thus, in vivo trials should be conducted as well. meanwhile, the findings of this study may serve as a starting point for future research into novel materials and other factors affecting bond strength. conclusion within the confines of this study, the following conclusions were reached : 15 -minutes oxygen and argon plasma treatment was successful in enhancing the shear bond strength of soft liner material to both of conventional acrylic and high impact acrylic denture materials. 2high impact acrylic showed higher sbs initially and following plasma treatment when compared to conventional acrylic. 3plasma treatment had no significant effect on microhardness and chemical structure of the tested acrylic materials. conflict of interest: none. references 1. noort r v. introduction to dental materials. fourth. elsevier ltd.; 2013. 2. agha h, flinton r, vaidyanathan t. optimization of fracture resistance and stiffness of heatpolymerized high impact acrylic resin with localized e-glass fiber force® reinforcement at different stress points. j prosthodont. 2016; 25(8): 647–55. 3. jagger dc, jagger rg, allen sm, et al. an investigation into the transverse and impact strength of “high strength” denture base acrylic resins. j oral rehabil. 2002; 29(3): 263–7. 4. yildirim az, unver s, mese a, et al. effect of argon plasma and er:yag laser on tensile bond strength between denture liner and acrylic resin. j prosthet dent. 2020; 124(6): 799. 5. tayebi l. applications of biomedical engineering in dentistry. first edit. springer; 2020. 6. mittal m, anil kumar s, sandhu hs, et al. comparative evaluation of the tensile bond strength of two silicone-based denture liners with denture base resins. med j armed forces india. 2016; 72(3): 258–64. 7. chladek g, zmudzki j, kasperski j. long-term soft denture lining materials. materials (basel). 2014; 7(8): 5816–42. 8. xiaoqing m, qiao c, zhang x, et al. improvement of the adhesive strength between silicone-based soft liner and thermocycled denture base with plasma treatment. 2015; (12). 9. motaal he, shakal ea, elkafrawy he, et al. effect of glow discharge and dielectric barrier discharge plasma as surface treatment on repaired acrylic denture base resin. 2017; 14: 68–75. 10. gherardi m, tonini r, colombo v. plasma in dentistry: brief history and current status. trends biotechnol. 2018; 36(6): 583–5. 11. aljudy hj. effect of plasma treatment of acrylic denture teeth and thermocycling on the bonding strength to heat cured acrylic denture base material. 2013; 25(1): 6–11. 12. bicer azy, dogan a, keskin s, et al. effect of argon plasma pretreatment on tensile bond strength of a silicone soft liner to denture base polymers. j adhes. 2013; 89(7): 594–610. 13. al-athel ms, jagger rg. effect of test method on the bond strength of a silicone resilient denture lining material. j prosthet dent. 1996; 76(5): 535– 40. 14. mustafa sb, hamad ti. the effect of plasma treatment on shear bond strength of high impact acrylic resin denture base lined with two types of soft lining materials after immersion in distilled water and denture cleanser. journal of baghdad college of dentistry. 2015; 27(4): 44-51. 15. machado al, breeding lc, vergani ce, et al. hardness and surface roughness of reline and denture base acrylic resins after repeated disinfection procedures. j prosthet dent. 2009; 102(2): 115–22. 16. ramanna pk. wettability of three denture base materials to human saliva, saliva substitute, and distilled water: a comparative in vitro study. j indian prosthodont soc. 2018; 18(3): 248–56. 17. zamperini ca, carneiro hdl, rangel ec, et al. in vitro adhesion of candida glabrata to denture j bagh college dentistry vol. 33(3), september 2021 effect of plasma 17 base acrylic resin modified by glow-discharge plasma treatment. blackwell verlag gmbh. 2012. 18. alamen, b. m. a., naji g. a. the effect of adding coconut oil on candida albicans activity and shear bond strength of acrylic based denture soft lining material. journal of research in medical and dental science. 2019; 6(5), 310-8. 19. american society for testing and materials. west conshohocken, pa, usa, d-638. 1986. 20. zhang h, fang j, hu z, et al. effect of oxygen plasma treatment on the bonding of a soft liner to an acrylic resin denture material. 2010; 29(4). 21. sparavigna a. plasma treatment advantages for textiles. man-made text. 2006; 49(3): 85–9. 22. lee mh, min bk, son js, et al. influence of different post-plasma treatment storage conditions on the shear bond strength of veneering porcelain to zirconia. materials (basel). 2016; 9(1). 23. dos santos dm, vechiato-filho aj, pesqueira aa, et al. effect of nonthermal plasma treatment on the surface of dental resins immersed in artificial saliva. j polym eng. 2016; 36(8): 785– 93. 24. munajad a, subroto c, suwarno. fourier transform infrared (ftir) spectroscopy analysis of transformer paper in mineral oil-paper composite insulation under accelerated thermal aging. energies. 2018; 11(2). 25. dorranian d, abedini z, hojabri a, et al. structural and optical characterization of pmma surface treated in low power nitrogen and oxygen rf plasmas. 2009; 1(3): 217–29. 26. hassouba m, dawood n. comparison of surface modification of cr-39 polymer film using rf and dc glow discharges plasma. j mod phys. 2017; 8: 2021–2033. المستخلص كاد الغرض لذلك،هد أنها تنفصييع ا عا ط م ا اناييناد فع طرط ةعينة ةا اداييطخ ا . لينةالعيب الرئيسييل لاداا الطينيا ال: الخلفية لكسيييجيا وانن دد لو عدط وانفالزةا تأثير ةعالجة يياةا هذا اليحث هد ت اللينة لند يا ةخطلفيا ةا ايننات لل ادلطصيييال ال صييي .انكريليك الل الص ةاتوانكريليك الط لي ي الاعالج حرانياً، ا اناناد: أم ةداا عا ط دخطييان عدط الصيييي ةيات،لكيع ةا ادكريلييك الط ليي ي وادكريلييك يالل ةا العينيات عنعية انفعياتا تحضييييير : مرائق العايع والاداا ل اعائق. فع ذلك، تات إضييا ة 5ةعالجة شييرط أزوام ةا العينات ةا كع ةجاد ة أكريليك فاليالزةا لا ط تتا . ثاادلطصييال ال صيي اا تا تحليع عدط ادلطصيال ال صيل فاايطخ ا لة اخطيان الاية. ك فع ها،ةااط الطينيا اللي نة الاعالجة فالحرانط إلو كع زوم ةا العينات. الازاو ة وللعينات للعينات t-testتا تحليع الييانات إحصائيًا فااطخ ا .afmو ftirتا تحليع صالفة يكرز ال عي ة وعافلية اليلع و (.α = 0.05) ،الاسط لة ل ل ةلحدظة النطائج: أظهرت النطائج زيااط ( 2نيدتا / ةا 2.3355عياة )فع العالم فاليالزةا فأ لو ةطداييي عدط ادلطصيييال ال صييي لا تطأثر الصيييالفة ال عي ة و اليلع،الاعالجة فاليالزةا. إلو انب ادنتفاع الكيير ل عافلية الصييي ةات انكريليك اللات لدحظ ل ين ففرٍل ةلحدظ فع الاعالجة فاليالزةا. الايننات فيا عدط ادلطصيال ال صيل كسيجيا وانن دد عالة فشيكع كيير ل تعزيزوانفيالزةا لجة اعاالكانت الخطا ،: ل ايطنطاماد وةداا انكريليك. اللينة creative articles published by journal of baghdad college of dentistry is licensed under a .commons attribution 4.0 international license https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ 4neda'a f.docx j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 22 a survey of prosthodontics techniques applied by dental practitioners in sulaimani city neda al-kaisy, b.d.s., m.sc., ph.d. (1) abstract background: prosthodontic services have changed markedly due to an introduction of new materials, techniques and treatment options. the aim of this study were to identify the type of materials and the methods used by dental practitioners in their clinics to construct conventional complete dentures and to specify the type and design for removable partial dentures (rpds); and to then compare them with those taught in dental schools. materials and methods: a total of 153 dental practitioners in sulaimani city completed a written questionnaire. the questionnaire included 19 questions regarding complete and rpds fabrication. results: most of the practitioners provide complete dentures (81.6%) and rpds (95.3%) in their clinics. polyvinyl siloxane 38.4% and irreversible hydrocolloid 37.6% impression materials were most commonly used to make the preliminary and zinc oxide eugenol 52% for final impressions. the majority of participants did not disinfect their impressions (73.9%). in order to establish the vertical and centric relations, different methods were used. many practitioners depend on dental technicians to determine the post-dum area (42.4%) and all of them faced different problems during fabrication of the complete denture. acrylic rpds were the main type of rpds provided (89.7%), followed by flexible partial dentures (70.5%). the minority constructed cast metal rpds (18.4%). conclusions: private practitioners did not perform most of the techniques nor use the procedures or materials that are being taught in dental schools. there is a need for continuing dental education programs for improving their clinical skills. moreover reassessing of the prosthodontic curriculum of the related dental schools is required. keywords: complete denture, rpds, impression, prosthodontics techniques, curriculum. (j bagh coll dentistry 2016; 28(3):22-29). introduction despite advances in preventive dentistry, edentulism is still a major public health problem worldwide (1).the prevalence of edentulism varies widely across regions and countries (2), as well as over time and with respect to age differences (3). age, educational level and socioeconomic status playing a vital role in toothlessness and denture demand (4). tooth loss constitutes a final common pathway for most dental diseases and conditions. it can lead to substantial impact on quality of life (3). naturally, to prevent some of these decrements in oral health-related quality of life, dentists frequently recommend removable or fixed prosthetic treatment (5). complete edentulism is mainly treated by conventional complete dentures. however, for a partially edentulous patient most clinicians choose removable partial dentures (rpds) to restore lost residual ridge. thus dentists are able to achieve appropriate esthetics, increase masticatory efficiency, and improve phonetics, which would not be possible to achieve with dental implants or fixed partial dentures (6). over the past few years, prosthodontic services have changed markedly due to an introduction of new materials, techniques and treatment options (7). (1)lecturer. department of prosthodontics, college of dentistry, university of sulaimani, iraq. the delivery of prosthodontics services by dental institutions is influenced by many factors: social and demographic characters, perceived need for care by patients, symptoms and esthetic concerns (8). most dental schools include complete and rpds in their curriculum, however they required a minimum number of cases in order to enable graduates to develop certain clinical skills (9-11). each dental school has its own educational philosophy regarding prosthodontics techniques. that said, dental school graduates may at times not fully comply with the techniques taught at university and instead attempt to pursue shortcut procedures (12,13). according to the prosthodontics curriculum of sulaimani school of dentistry, prosthodontics modules start early in the second year, concentrated on theoretical and laboratory teaching of a complete denture. during the third year, cast metal rpds-teaching takes place. clinical prosthodontic work is put into practicein the fourthand fifth academic years, alongside theoretical instruction for rehabilitation alternative prosthesis and dental implants. complete dentures and acrylic rpds are clinical requirements for graduation, reline and rebase in addition to repair cases. cast metal rpd, immediate and over denture are not included in students' final grade. dental implant treatments are not within the clinical practice of undergraduates. regarding the materials and methods used in sulaimani school of dentistry, the traditional j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 23 final impression technique that includes preliminary and final impression is the technique recommended for constructing a set of complete dentures. the impression compound is used for the preliminary impression and zinc oxide (in a border-molded close fit custom acrylic tray) used for the final impression. no face bow is used to transfer the position of the maxillary arch and jaws relation is recorded with wax occlusion rims. semi adjustable articulators, without registration of any eccentric records, are used for casts’ articulation. polyvinyl siloxane (pvs) impression materials are used in indicated cases like the presence of severe undercut. this study was undertaken to gather data on current prosthodontic practice activities (types of materials and techniques) performed by dentists in sulaimani; thus providing an opportunity to identify some of the existing trends used in complete and rpd services. in addition, it attempts to recognise the problems encountered by dental practitioners in various prosthodontics treatments. moreover, this study aims to compare dental school curriculums and techniques with the clinical practices of their students. the data could direct and support tutors in designing effective education courses and prosthodontic curriculums. materials and methods a questionnaire pro forma was planned to determine the type of prosthodontic techniques and materials used in dental practice in sulaimani city, iraq. the questionnaire included 15 questions concerning complete dentures and 4 questions related to partial dentures. the proformas were delivered and collected through personal visits to 153 dental practitioners. the study was approved by the medical ethics committee, school of dentistry, university of sulaimani. for complete denture treatment, respondents were asked to specify the following: the materials used for preliminary and final impressions, custom tray spacer and materials, vertical and centric relation records, disinfection of impression, main problems in fabrication of complete dentures, and post care instructions. while for partial denture treatment, respondents were asked to declare the following: types of partial denture provided, an instruction to the technician regarding surveying, framework design, and clasps position. raw data was tabulated in microsoft excel and descriptive analysis (frequency and percentages) was estimated. results the current status for prosthodontic practice in various dental clinics in sulaimani city indicates that most of the participating dentists were working in private clinics (75.1%), while (16.3%) are working in private centres and (8.5%) are working in government health centres (specialised and non-specialised) (table 1). details about graduating classes and specialties of respondents are listed in table 2. most practitioners (81.6%) provide complete dentures in their clinics (22.2% of them did not routinely provide this service), while (18.4%) of practitioners did not provide this service at all. for rpds construction, 84.9% frequently provide the service and the minority of practitioners (4.5%) did not perform this service in their clinics (table 3). regarding the impression materials used to fabricate preliminary and final impressions for complete dentures, 33 of 125 dentists (26.4%) who constructed complete dentures in their clinics used more than one type of material. dentists preference for preliminary impression material was for a combination of heavy body and light body of pvs, irreversible hydrocolloid and impression compound (38.4%, 37.6% and 32.8% respectively), followed by heavy body material which was used only by 20.8% of dentists. a minority of participants used impression compound with irreversible hydrocolloid wash for making a preliminary impression (8.8%) (table 4). while forfinal impression materials, the majority of dentists (52%) used zinc oxide impression materials (40% with tracing and 12% without tracing border molding). the second most common material used was a combination of heavy body and light body of pvs (24%). the use of light body material alone constituted (25.6 %) (with and without border molding). a minority of practitioners used irreversible hydrocolloid as final impression material (9.6%) (with and without border molding). finally, of the 125 practitioners who fabricated complete dentures, 12% considered their preliminary impression as final (table 4). regarding impression trays, most respondents preferred close fit custom tray. the results indicate that 110 participants (88%) routinely used custom trays for complete denture cases. 84% of them used custom tray constructed from auto polymerizing acrylic resin, the remaining practitioners (11.8%) used light-curing resin, and only 0.9% used shellac (table 5). unexpectedly, 62.4% of those who constructed complete dentures did not use fox bite to determine occlusal plan. j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 24 table 1: practice type among sulaimani dentists (n=153). practice type number % private clinic 115 75.1 private center 25 16.33 health centre specialized 8 5.22 non-specialized 5 3.26 table 2: graduation years and specialty of participants graduation years number % bachelor of dental surgery specialty prosthodontist others 1970-1979 7 4.5 ----------1 (0.6%) 6 (3.9%) 1980-1989 17 11.1 2 (1.3%) 7 (4.5%) 8 (5.2%) 1990-1999 45 29.4 9 (5.8%) 15 (9.8%) 21 (13.7%) 2000-2009 69 45.09 30 (19.6%) 5 (3.2%) 34 (20.2%) 2010-2014 15 9.8 14 (9.1%) -----------1 (0.6%) table 3: conventional complete and partial denture construction among participants providing the service non providing the service total frequently providing the service uncommonly providing the service complete denture 125 (81.6%) 91 (59.4%) 34 (22.2%) 28 (18.4%) partial denture 146 (95.3%) 130 (84.9%) 16 (10.4%) 7 (4.5%) table 4: types of preliminary and final impression materials used for complete denture number % preliminary impression impression compound 41 32.8 irreversible hydrocolloid 47 37.6 impression compound+ irreversible hydrocolloid 11 8.8 polyvinyl siloxane heavy body 26 20.8 polyvinyl siloxane heavy body+ light body 48 38.4 final impression zinc oxide eugenol with tracing 50 40 without tracing 15 12 irreversible hydrocolloid with tracing 9 7.2 without tracing 3 2.4 impression compound with irreversible hydrocolloid wash 1 0.8 polyvinyl siloxane light body with tracing 17 13.6 without tracing 15 12 polyvinyl siloxane heavy body+ light body 30 24 no final impression, depend on the preliminary 15 12 table 5: types and materials of custom tray used to register final impression for complete denture. close fit custom tray 110 (88%) material of custom tray acrylic 84.5% light cure 11.8% custom tray with spacer 27 (24.5%) shellac 0.9% the response to questions concerning impression water rinsing and disinfection revealed that 72 dentists (49.4%) wash the impressions with water, 43 of them (59.7%) followed this with disinfectant. the most frequent disinfectant material used was alcohol (73.6%). conversely, 73.9% of the participants did not disinfect their impression before dispatching to their technicians (table 6). j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 25 table 6: impression water rinsing and disinfection no yes water rinsing 74 (50.6%) 72 (49.4) water rinsing alone 29 (40.2%) water rinsing followed by disinfection 43 (59.7%) disinfectant 108 (73.9) 38 (26.1) type of disinfectant bleaching 4 (10.5%) alcohol 28 (73.6%) glutimid 5 (13.1%) others * 1 (2.6)% * amonia compound disinfectant. in order to establish the occlusal vertical dimension, 42 respondents (33.6%) used two methods to determined occlusal vertical dimension, while 27 (21.6%) used more than two methods (3-4 methods). the extra-oral measurements constituted (73.9%), followed by aesthetic (51.2%), phonetic (40%) and swallowing (27.2%). one prosthodontist reported that when available, he used patients' previous records (table 7). the centric relation registration by positioning techniques performed by clinicians (bimanual and figure-thumb chin manipulation) showed the lowest percentage (16%), followed by positioning techniques performed by the patients (tongue raised and placed in the posterior part of the palate) 24%. the majority of respondents depended on both techniques (60%) (table 7). for post-dum position determination, the majority of dentists (53.6%) used a combination method (ah method, a blow from the nose, fovea palatine method). while 42.4% of them relied on their technicians to determine the post-dum area. only 4 % of them used physiologic method (fluid wax technique) (table 7). the percentages reported for the problems faced during and after the construction of complete dentures were as follows; repeated post insertion adjustment visits (43.2%), poor laboratory work (34.4%) and poor retention (37.6%). 30.4% of dental practitioners faced problems in registering jaw relation records. 22.4% of dentists found complete denture construction to be a time-consuming clinical procedure. a minority of the participants (2.4%) related the problems to patients’ attitudes and difficulty in determining the post-dum area (table 7). table 7: methods of registration vertical dimension, centric relation records and post-dum area in addition to the main problems in fabrication of complete dentures number % registering vertical dimension extra oral measurements 87 69.6 aesthetic 64 51.2 phonetics 50 40 swallowing 34 27.2 previous patient’s records 1 0.8 registering centric relation clinician 20 16 patients 30 24 both 75 60 registering post-dum area combination 67 53.6 technician 53 42.4 physiologic method 5 4 problems in fabrication of complete dentures jaw relation 38 30.4 retention 47 37.6 time consuming 28 22.4 poor laboratory work 43 34.4 frequent post insertion adjustment 54 43.2 others* 3 2.4 * patient’s attitude and difficulty in determining the post-dum area. j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 26 for rpds construction, 131 respondents (89.7%) provided acrylic partial dentures for their patients in their clinics, followed by flexible partial dentures (103, 70.5%). the minority constructed cast metal partial dentures (27, 18.4%) (table 8). from the data, it seems that dentists give instructions to their technicians about the design of partial dentures rather than surveying instructions. 74.6% gave instruction to their technicians regarding partial denture design and clasps position, while only 36.9% gave instruction for cast surveying (table 8). finally, the majority of dental practitioners give post care instruction of removable appliances verbally (96.5%). table 8: types of removable partial dentures constructed and the dentist’s instruction regarding rpds design given to the technicians. number (%) types of rpd* acrylic rpd 131 (89.7%) flexible rpd 103 (70.5%) metal rpd 27 (18.4%) dentists instruction regarding: design of rpd 109 (74.6%) cast surveying 54 (36.9%) *rpd: removable partial denture discussion although the sample size in this study is limited, the variant structure (different graduation year, different specialties, and different clinical sectors) of participants seems to adequately represent sulaimani’s dentists. sulaimani dentists continue to provide considerable numbers of conventional complete and rpds within their clinical practice. most respondents constructed rpds, however the formal is less frequent. the preference in construction of rpds may be due to patient satisfaction with rpd retention and comfort over than those wearing complete denture, particularly the mandibular denture (14). many studies indicate that impression compound is the material of choice for making a preliminary impression (12,15). others found that irreversible hydrocolloid was the preferred preliminary impressions material (9,12). however, the findings of this study show that a third of the practitioners used impression compound for their preliminary impressions; which is similar to the results reported by gambhir et al (13). on the other hand, irreversible hydrocolloid and a combination of heavy and light bodies of pvs impression materials were most commonly used as preliminary impression materials among sulaimani dentists, over a third respectively. the majority of prosthodontics organisations believe that for a successful complete denture outcome to be achieved, it is necessary to make two impressions; preliminary and final (16,17). furthermore, it is difficult to find reliable data on the prevalence of a one-step impression procedure (16). although in a study done by kawai et al (18) it was found that the traditional final impression technique (a two-step procedure) resulted in the same patient satisfaction and denture quality as the simplified impression technique (one step procedure). in this study, the majority of participants preferred both preliminary and final impressions as part of complete denture therapy. furthermore, only 12% of the practitioners followed single impression technique compared to 15% of a previous study done by gambhir et al (13). regarding the materials used for final impression, zinc oxide and pvs impression materials were the preferred final impression materials, withirreversible hydrocolloid constituting a small percentage. this is markedly different from those used in a previous study, in which they reported irreversible hydrocolloid to be the preferred final impression material, followed by zinc oxide and pvs (12). the current results indicated that more than a third of participants still follow what they were taught in their undergraduate study regarding the final impression material of choice (zinc oxide impression materials with border molding). however, there is a movement toward the use of pvs as final impression materials. the majority of participants make the final impression using a custom tray and this matches the results obtained from a survey conducted in the uk (19). most participants adopted a closed custom fit tray. although, several studies have suggested for better impression results, the use of adequate spacer over the entire denture bearing area with vertical tissue stops (17, 20). the new materials of constructing custom trays are still not commonly available for sulaimani dentists. the material of choice was auto polymerizing acrylic resin. the minority used a light-curing resin. this finding is dissimilar to that published in a study done in the usa (21), j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 27 in which the majority of practitioners used light polymerized resin (60%). determining the occlusal plane using fox bite is important for ideal teeth arrangement in order to achieve esthetics and phonetics (22). but the majority of participants in this study did not use fox bite. this in turn may adversely affect patients satisfaction regarding their complete denture esthetic and occlusion. so further surveying of sulaimani dental institutions may provide a more accurate picture of complete denture patient’s satisfaction. the fact that the majority of respondent did not routinely disinfect impressions before pouring the cast or dispatching to a dental laboratory was a cause for concern. of greater concern was the apparent failure of many respondents to identify the appropriate method of disinfection, with more than third opting only to rinse impressions in water. this is fewer than the number found by hyde and mccord (12) in a survey conducted in the uk to identify current clinical practices followed by general dental practitioners. the assessment of occlusal vertical dimension will become more reliable if several methods are used simultaneously (23). more than half of participants depend on 2 to 4 different methods to register vertical dimension. extra oral and esthetic were the most common methods. various registration methods for centric relation have been described in the literature, but there is no consensus on which is the best (24). a large percentage of participants used two methods; positioning techniques performed by both the clinicians and patients, which is similar to other dental schools (11). sulaimani dentists tried to follow the right procedures for registering the vertical and centric relations as they realised that most complete denture problems arise from errors in these measurements. it has been reported by various authors that the best way to record the posterior palatal seal area is by using a combination of methods (25,26). just over half of participants followed more than one method in determining the post-dum area. the remaining participants completely relied on the dental technician to localize and prepare the postdam. however, this is still fewer than the numbers found in another study conducted in the uk (27). again unlike other previous studies (28,29), the minority of participants followed the physiologic method. there were many problems quoted by the practitioners during and after the fabrication of complete dentures. most of the problems directly related to the prosthodontics technique used, for example problems regarding retention and jaw relation records. issues were raised regarding the proficiency of practitioners at certain techniques which resulted in complaining at frequent post insertion adjustments, considered complete denture service a time-consuming procedure, as well as feeling technicians work was inadequate (13). several factors could help determine whether a cast metal framework or acrylic resin rpd is constructed. the expense of the service, capabilities of dental laboratory support, location and extent of missing teeth in addition to prosthodontics education may play a role in selection the type of rpds (30). although dental students spend a significant amount of time studying the cast metal rpds, this type of treatment was not in the participants repertoire. it has been demonstrated that the majority of participants provide acrylic and flexible partial dentures far more regularly than cast metal framework. this finding matched previous studies (31, 32). acrylic rpds continue to be used with great frequency (33). moreover, newer types of flexible acrylic or vinyl rpds have received much attention from sulaimani practitioners. this type of rpds began to be used in clinical services over the past decade (30). although much research has been conducted to test the properties of these materials (34,35) there has been no recent peerreviewed comparison of the prevalence of these different rpd framework materials. thus, further studies are needed to fill this gap. it isreported that surveying of the diagnostic cast is mandatory for fabricating cast metal partial dentures (36). but only one third of the practitioners in this study instructed their technicians to do this surveying, similar to the findings of gambhir et al (13). those dentists who instructed their technicians in surveying and construction of rpds other than cast metal, may need to localise teeth undercuts and retentive areas that help in designing the rpds framework. however, the majority of respondents were giving instruction on rpds design to technicians. verbal instructions given to the patient by the dentist is a crucial step post denture insertion. however written information has been shown to improve patient knowledge, adherence and therapeutic outcomes. it is also highly effective in achieving improved clinical outcomes and compliance (37,38). unfortunately, the minority of participants supplied their patients with written as well as verbal post care instructions. it is important to conduct general surveys analysing and comparing the current prosthodontics curriculum of different dental schools in the country, in order to gauge the j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 28 general trend in the teaching techniques of prosthodontics. these studies could also specify the prosthodontics materials and techniques followed by dentists graduating from different dental schools. there is some disconnection between the undergraduate prosthodontic curriculum and the general prosthodontics practice in different dental clinics. the majority of the practitioners try to follow short cut procedures, and many of them lack the knowledge regarding prosthodontic materials and techniques. thus, it is crucial to establish continuing dental education programs, teaching and training courses in complete and rpds prosthodontics and to clarify the importance of basic techniques and new materials. in addition, the undergraduate teaching curriculum may need to be revised and improved to include tracking the continuous development in prosthodontics techniques and materials. this revision could overcome any weakness or deficiency in prosthodontics knowledge demonstrated in the results of studies like this. references 1. emami e, de souza rf, kabawat m, feine js. the impact of edentulism on oral and general health. int j dent 2013; 498305. 2. petersen pe, bourgeois d, ogawa h, estupinan-day s, ndiaye c. the global burden of oral diseases and risks to oral health. bull world health organ 2005; 83: 661–9. 3. mojon p. the world without teeth: demographic trends. in: feine js cg, editor. implant overdentures: the standard of care for edentulous patients. chicago: quintessence; 2003. p.3–14. 4. al hamdan e, fahmy mm. socioeconomic factors and complete edentulism for female patients at king saud university, riyadh, saudi arabia. tanta dent j 2014; 11:169–73. 5. öwall, bengt, arnd f. käyser, and gunnar e. carlsson. prosthodontics: principles and management strategies. london: mosby-wolf; 1996. p.35-48. 6. bohnenkamp dm. removable partial dentures: clinical concepts. dent clin north am 2014; 58: 69– 89. 7. manski rj, goodman hs, reid bc, macek md. dental insurance visits and expenditures among older adults. am j public health 2004; 94:759–64. 8. gilbert gh, duncan rp, vogel wb. determinants of dental care use in dentate 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wearers.j dent 2003; 31: 445–51. 15. bachhav vc, aras ma. a simple method for fabricating custom sectional impression trays for making definitive impressions in patients with microstomia. eur j dent 2012; 6: 244–7. 16. carlsson ge, örtorp a, omar r. what is the evidence base for the efficacies of different complete denture impression procedures? a critical review. j dent 2013; 41: 17–23. 17. mccord jf, grant aa. impression making. br dent j 2000; 188: 484–92. 18. kawai y, murakami h, shariati b, klemetti e, blomfield jv, billette l, et al. do traditional techniques produce better conventional complete dentures than simplified techniques? j dent 2005; 33: 659–68. 19. al-ahmar ao, lynch cd, locke m, youngson cc. quality of master impressions and related materials for fabrication of complete dentures in the uk. j oral rehabil.2008; 35: 111–5. 20. bindhoo ya, thirumurthy vr, kurien a. complete mucostatic impression: a new attempt. j prosthodont 2012; 21: 209–14. 21. mehra m, vahidi f, berg rw. a complete denture impression technique survey of postdoctoral prosthodontic programs in the united states. j prosthodont 2014; 23: 320–7. 22. monteith bd. a cephalometric method to determine the angulation of the occlusal plane in edentulous patients. j prosthet dent 1985; 54: 81–7. 23. den haan r, witter dj. occlusal vertical dimension in removable complete dentures.ned tijdschr tandheelkd 2011; 118: 640–5. 24. utz kh, müller f, lückerath w, fuss e, koeck b. accuracy of check-bite registration and centric condylar position. j oral rehabil 2002; 29: 458–66. 25. fernandes va, chitre v, aras m. a study to determine whether the anterior and posterior vibrating lines can be distinguished as two separate lines of flexion by unbiased observers: a pilot study. indian j dent res 2008; 19: 335–9. 26. lye, t.l. the significance of the fovea palantini in complete denture prosthodontics. j prosthet dent 1975; 33: 504–10. 27. basker rm, ogden ar, ralph jp. complete denture prescription--an audit of performance. br dent j 1993; 174: 278–84. 28. chen ms. reliability of the fovea palatini for determining the posterior border of the maxillary denture. j prosthet dent 1980; 43: 133–7. 29. rashedi b, petropoulos vc. current concepts for determining the postpalatal seal in complete dentures. j prosthodont 2003; 12: 265–70. j bagh college dentistry vol. 28(3), september 2016 a survey of prosthodontics restorative dentistry 29 30. pun dk. incidence of removable partial denture types in eastern wisconsin. a master thesis. marquette university, 2010. 31. lewandowska a, speichowicz e, owall b. removable partial denture treatment in poland. quintessence int 1989; 20: 353–8. 32. radhi a, lynch cd, hannigan a. quality of written communication and master impressions for fabrication of removable partial prostheses in the kingdom of bahrain. j oral rehabil 2007; 34: 153–7. 33. allen pf, jepson nj, doughty j, bond s. attitudes and practice in the provision of removable partial dentures. br dent j 2008; 204(1): e2. 34. shah j, bulbule n, kulkarni s, shah r, kakade d. comparative evaluation of sorption, solubility and microhardness of heat cure polymethylmethacrylate denture base resin & flexible denture base resin. j clin diagn res 2014; 8: zf01–4. 35. takahashi y, hamanaka i, shimizu h. effect of thermal shock on mechanical properties of injectionmolded thermoplastic denture base resins. acta odontol scand 2012; 70: 297–302. 36. lechner sk, thomas ga. removable partial denture design: importance of clinical variables. eur j prosthodont restor dent 1994; 2: 127–9. 37. segador j, gil-guillen vf, orozco d, quirce f, carratalá mc, fernández-parker a, et al. the effect of written information on adherence to antibiotic treatment in acute sore throat. int j antimicrobiol agents 2005; 26: 56–61. 38. weinman j. providing written information for patients: psychological consideration. j r soc med 1990; 83: 303–5. j bagh college dentistry vol. 29(1), march 2017 evaluation of osseointegration oral and maxillofacial surgery and periodontics 96 evaluation of osseointegration of dental implants prepared by piezosurgery (clinical study) younus jabbar jiheel, b.d.s. (1) jamal abid mohammed, b.d.s., m.sc. (2) abstract background: piezosurgery device is a system developed recently to overcome the limitation of the traditional surgical technique in implant site preparation, which use the principle of ultrasonic microvibrations to create precise & selective cut in bone in harmony with the surrounding tissues. the aim of this study was to evaluate the outcomes of implants inserted by ultrasonic implant site preparation protocol (uisp) using piezosurgery device, regarding the survival rate, stability and other related factors, at 16 weeks postoperative follow up period. materials and methods: a total of (24) patients, (6) males and (18) females, aged between (19-51) years old, contributed in this study receiving a total of (42) implants, all of these implants bed were prepared by means of special tips mounted in piezosurgery device. for each patient thorough clinical and radiographical preoperative assessment was applied. implant stability quotient (isq) values were measured at baseline, 8 weeks and at 16 weeks. postoperative clinical and radiographic evaluation was applied for each patient for 16 weeks postoperatively. results: (24) patients received (42) implants accomplished the follow-up period, after 16 weeks all implants (42) were osseointegrated and the overall implants survival rate was 100% with no failure and no complication was observed. the mean isq value at baseline was (74.32±6.42), the mean isq value at 8 weeks was (72.62±9.05) and at 16 weeks the mean isq (±sd) value was (76.68±7.35) the changes in the mean stability during the healing period showed significant increase in the implant stability (p≤0.05). at the 16th week the number of implants that achieved isq≥70 was 35 (83.3%), and 7 implants attained isq> 70 (16.7%). conclusions: high and significant survival rate, significant secondary stability, early positive shifting of the mean isq value, no remarkable complications in implants inserted by ultrasonic implant site preparation indicated that piezosurgery is a reliable alternative and safe method used in dental implant osteotomy. key words: piezosurgery dental implant, survival rate, rfa. .(j bagh coll dentistry 2017; 29(1):96-103). introduction to overcome the limitations of traditional techniques (a lot of heat production during bone cutting and the high amount of external copious irrigation required, application of significant pressure in osseous surgeries so endangered management of fractured and delicate bones) (1) (2) (3) scientists introduce an advanced therapeutic devices which use the principle of ultrasonic microvibrations to create precise and selective cut on the bone in harmony with the surrounding tissues, (2) (3) so the innovation of piezosurgery creates new possibilities in accomplishment of osteotomies using piezoelectric device. the effect of piezosurgery device has been widely investigated in many fields of orthopedics, periodontology, oral & maxillofacial surgery and implantology. clinical studies have suggested that piezosurgery used in implant site preparation resulted in high initial (primary) stability and earlier shifting from primary to secondary stability. (1) master student, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. (2) assistant professor, department of oral and maxillofacial surgery, college of dentistry, university of baghdad. also histological and biomolecular studies on bone healing in areas where the osteotomy is performed using piezosurgery® demonstrated many more advantages to healing than using bone burs. (4)dental implants success rate and survival depend primarily on osseointegration which was defined by branemark as the “direct structural and functional connection between the ordered living bone and the surface of load carrying implant”. (5) osseointegration is affected by many factors such as implant material and its biocompatibility, loading protocols (delayed or immediate), patient factors, implant design, primary stability and the surgical technique. implant stability is one of the important factors for achieving successful osseointegration, and the overall implant stability can be evaluated and monitored by many clinical methods (invasive) and (noninvasive) and osstell mentor represents a clinical noninvasive device used to delineate stability of implant via magnetic frequencies between a magnetic peg (smart peg) adapted to the top of the implant and a resonance frequency analyzer. (6) (7) the aim of the study was to evaluate the outcomes of implants inserted by ultrasonic implant site preparation protocol (uisp) using piezosurgery device, regarding the survival rate, stability and other j bagh college dentistry vol. 29(1), march 2017 localization of maxillary oral and maxillofacial surgery and periodontics 97 related factors, at 16 weeks postoperative follow up period. materials and methods this clinical study was conducted at the department of oral and maxillofacial surgery, college of dentistry, university of baghdad during the period from november 2014 to october 2015.the sample included patients indicated for implant treatment to replace single or multiple maxillary and mandibular lost teeth, implant sites were prepared using (uisp) protocol using piezosurgery device, fixtures installed into the prepared site, by means of twostage implant surgery protocol. the inclusion criteria were healed edentulous area for at least 6 months after extraction, age above 18 years, good oral hygiene, bone volume must be at least 6 mm in width, enough available bone height and at least 6mm mesiodistally and d2 and/or d3 bone density.(misch, 1988)(8) the patients excluded from this study were those with any known systemic diseases that affect dental implants, radiotherapy of the head and the neck within the past 24 months, bisphosphonate history, heavy smokers (>20 cigarettes/day), uncontrolled diabetics, and patient with parafunctional habits, pregnant or lactating women, immunocompromised patients, patients unable to return back for follow up and study recall, medical condition that preclude any surgical intervention such as patient with bleeding disorders or recent myocardial infarction, psychiatric problem, and patients with pacemaker, close proximity of vital structure such as maxillary sinus and mental foramen and inferior alveolar nerve that make impossible to reach the required implants length, insufficient bone volume, width, length and mesio-distal dimension to insert implants, sites that need augmentation or regenerative treatment (dehiscence or fenestration of the residual bony wall), active advanced uncontrolled periodontal disease and bad oral hygiene. preoperative assessment for each patient a preoperative assessment starting with detailed personal information, previous medical and dental history, and reviewing all inclusion and exclusion criteria mentioned before. clinical examination included the oral hygiene condition, the absence or presence of active periodontal disease, the edentulous area condition, estimation of the dimensions of the edentulous space, the intra-arch distance. radiographic assessment preoperative (opg) to assist in the selection of the correct length of the fixture, determination of available bone height, estimation of the root inclination of the adjacent teeth, presence of any pathological condition and the proximity to the vital structures (fig.1). figure1:diagnostic preoperative panoramic radiograph (opg). surgical procedure prior to surgery perioral skin was scrubbed with povidone-iodine solution and every patient was instructed to rinse his/her mouth with chlorhexidine mouthwash (lacalut co. ltd) for one minute before surgery. infiltration technique were used for all surgical procedures, (lidocaine 2%, adrenalin 1:100000, 2.2 ml cartridge, septodont, france), as a local anesthesia. full thickness three sided mucoperiosteal flaps were raised and the underlying bone was exposed with palatal bias of the crestal incision in the maxilla and slightly lingually in the mandible, in order to provide a good coverage of the fixture with keratinized soft tissues and prevent the presence of the fixture beneath the suture line. calibrated periodontal probe was used for direct bone measurement to make sure that the width of the bone (bucco-lingual & mesio-distal) is not less than 6mm. (fig. 2a) & (fig. 2 b). figure 2: athree sided mucoperiosteal flap with palatal bias (black arrow). b ridge width measurement by periodontal probe. piezosurgery device ( mectron co, italy) (fig.3) & special tips mounted on the device (implant site preparation kit) especially designed & used for the preparation of the implant sites) ( fig.4). using (uisp) protocol by vercellotti. a b j bagh college dentistry vol. 29(1), march 2017 localization of maxillary oral and maxillofacial surgery and periodontics 98 figure 3: piezosurgery device (mectron co., italy). figure 4: implant site preparation tips (mectron co., italy). the preparation started with im1s insert which is used for the initial osteotomy (fig. 5) then the 2nd insert (im2a, im2p2mm in diameter) used as the pilot osteotomy reached to the planned working length (fig. 5). then the implant site preparation continued with (p2-3) insert which is used for enlargement of the of the osteotomy site to accommodate the next implant site preparation tip (fig. 5). the next insert used in the preparation is the (im3a and im3p) inserts to enlarge or to finalize the implant site preparation to accommodate the dental implant with 3 mm diameter. in the posterior area the implant site preparations continued by using the p3-4 insert which used to optimize concentricity of implant site preparation between ø 3 and ø4 mm. after that insert im4p was used in implant site preparation to accommodate the implant fixture size 4.3 and 4.8 mm (fig.5). directional pins supplied with the operator kit were used step by step to check the preparation axis and corrections were made when needed. using these inserts need special techniques, all inserts should rotate in clock and anti-clock wise except im1 insert movement in upward and down ward direction. for all inserts minimum pressure should be applied on the inserts (not exceeding 300 gram) according to the manufacturer instructions. the implant fixture (dentium co.,s.l.a korea) inserted at or just below the crestal bone level. figure 5: complete surgical procedure of implant site preparation using piezosurgery (in sequence from a-i). the implant stability evaluation was accomplished by osstell™ isq (goteborg, sweden, 4th generation). smart peg (type six), screwed at the top of implant fixture by using smart peg mount. the transducer probe was directed perpendicular to the top of the smart peg with a distance of approximately 2mm and held stable until the device beeped and displayed the isq value. the measurements were taken twice in bucco-lingual and mesio-distal directions (fig.6 a), the mean of the two measurements represents the primary stability value (isq) baseline. then a cover screw was inserted over the implant fixture (fig.6 b). figure 6: a-isq measurement, b-cover screw placement. the surgical wound closed by simple interrupted suture using 3/0 non-resorbable black silk suture (dynek, australia). patients were instructed to apply cold packs on the side of the surgery adjacent to the involved area for the rest of the surgery day and the patients also instructed to avoid chewing or applying any pressure on the site of the surgery, b a b c d e f g h i a j bagh college dentistry vol. 29(1), march 2017 localization of maxillary oral and maxillofacial surgery and periodontics 99 avoid wearing a denture, eating warm diet and rinsing the mouth at the day of surgery. the patients medicated by amoxicillin capsules 500mg three times daily for five days post-operatively, and for patients who were allergic to penicillin, azithromycin tablets (500 mg one time per day for three days), and metronidazole tab. (500mg three times daily).the antibiotic treatment continued for 5 days. mefenamic acid tablets 500mg taken as analgesic on need. the patients were instructed to use a chlorhexidine mouth wash 0.12% (for one minute, twice daily for two weeks). sutures were removed at 10-14 days after the surgical procedure. follow up and data collection the patients were recalled in 2, 8, 16 weeks for follow up and stability recording. after 2 weeks the sutures were removed and all the patients were evaluated for pain, discomfort, suppuration, cover screw exposure and any sign of infection. after 8 weeks all implants were exposed using soft tissue punch (dentium co., korea) the smart peg fixed to the implant top and isq value calculated by osstell (goteborg, sweden, 4th generation) with buccoligual and mesiodistal direction, the record documented as secondary implant stability at 8 weeks' time interval. at this appointment a suitable healing abutment (gingival former) was placed at the implant top (fig. 8a). at 16 weeks all the patients had an opg radiograph to assess the relation of implanted fixture with the other dentition and vital structures and for the final documentation (fig.7). figure 7: postoperative opg of the same patient in figure 1 taken at 16 weeks. at 16 weeks second reading of stability was measured by osstell with buccoligual and mesiodistal direction, the record documented as secondary implant stability at 16 weeks. at this time an impression was taken for prosthesis construction (fig.8b). figure 8: agingival formers in its place inside fixture body during the 2nd stage surgery. bfinal prosthesis. statistical analysis data description, analysis and presentation were performed using statistical package for social sciences (spss version 18) and microsoft office excel 2007). frequency, percentage for qualitative variables, minimum, maximum, range, mean, sd and se for numeric variables (quantitative).two independent sample t-test, and pearson correlation (r), non-parametric chi-squared (x2), friedman test were the statistical methods used to analyze the data. the level of significance tested according to the p-value, were: p>0.05 (not significant), p<0.05 (significant), p<0.01 (highly significant). results a total of (24) patients with (42) dental implants were inserted by ultrasonic implant site preparation (uisp) protocol (piezosurgery) and were recalled at 8 and 16 weeks for follow up and data recording. thirty one (73.8%) of implants for female and 11 (26.2%) of implants for male patients. twenty four (57.1%) of implants were inserted in the maxilla and 18 (42.9%) implants were inserted in the mandible. the implants lengths were used in this study: 8mm length (8 fixtures), 10mm (10 fixtures and 12mm (24 fixtures). the diameter of the implants used in this study was: 3.4(14 fixtures), 3.8 (13 fixtures), 4.3 (15 fixtures). all the implants (42) were osseointegrated and overall of implants survival rate 100% of implants with no failure and no complication during the follow-up period. the mean isq value and standard deviation at base line was (74.32isq±6.42) with a range (55.50-85.00 isq), the mean isq value and standard deviation at 8 weeks was (72.62isq±9.05) with a range (54.00-86.50 isq) (fig.9). the mean isq value a b j bagh college dentistry vol. 29(1), march 2017 localization of maxillary oral and maxillofacial surgery and periodontics 100 and standard deviation at 16 weeks was (76.68±7.35), t-test showed high significant increase in the isq value from the primary stability at baseline to the secondary stability at 16 weeks (p<0.01). figure 9: line diagram showing the changes of mean isq (implant stability) at the time of surgery and after 2 successive intervals. the mean isq at baseline was distributed as follow: high stability ≥70 (32 implants, 76.19%) low <60 isq were 2 (4.76%), medium >60 and <70 isq were8 (19.05%). the mean isq at 8 weeks distributed as follow: high stability ≥70 isq 26 (61.90%) implants, low <60 isq 5 (11.90%) medium >60 and <70 isq 11 (26.19%).at 16 weeks the mean isq distributed as follow: high stability ≥70 isq were 35 (83.33%) implants, medium >60 and <70 isq were 6 (14.29%) implants, low <60 isq were 1 (2.38%) implant (fig.10). figure 10: the rate of implants attained high stability (isq≥70) & (isq>70) at surgery and after 2 successive intervals (8, 16 weeks respectively) (isq threshold level isq>60 low stability, isq 60-70 medium stability, isq< 70 high stability). discussion the results of this clinical study show an excellent short term survival rate. all implants were successfully osseintegrated and the survival rate achieved in this study was (100%) without any evidence of failure and no remarkable complications for 16 weeks (about 4 months) follow up period, which meet the criteria of success of dental implant presented by misch et al (9) and this is in the line with many recently published clinical studies. (10) (11) (12) (13) the high excellent survival percentage (100%) in this study could be explained by, the application of this new surgical technique (ultrasonic implant site preparation) protocol using mectron-piezosurgery device which is characterized by precise selective cutting, less traumatic, internal cooling, micro-vibration, selective cutting, cavitation’s action, proper case selection, local oral health measure, oral and general health, proper selection of the implants site regarding the bone volume (3d) without any bony defect (dehiscence or fenestration), strict rules of aseptic technique, preoperative preparation, postoperative instructions and follow up, all these factors may explain this high percentage of survival (success) rate in this study. da silvaneto, et al (12) in their clinical study comparing the stability of dental implants by conventional or piezosurgery showed that all implants survived and were well osseointegrated. vercellotti, et al (13) in their extensive multicenter clinical study using ultrasonic device analyzing 3,579 implants with a 1-3 years follow up showed 97.74% overall survival rate without remarkable surgical complications. the lowest mean value (isq) of stability recorded at the 8th week after implant placement is (72.62) isq, compared to the mean value (isq) of primary stability recorded at the time of surgery (74.32) isq, then at the 16th week post implant placement in which the mean value increased to (76.68) isq, these findings represent a normal change that occurred during the healing period and the ongoing osseointegration process at the bone-implant interface, and this process could reflect the transition from the primary mechanical stability to the secondary biological stability as a result of osteoclastic activity during the early postoperative healing period cause decrease in the initial mechanical stability.(14)(15)(16) the decrease and following increase in the mean isq values in this study are in accordance with many clinical and experimental studies using piezoelectric devices in implant site preparation osteotomy(11)(12)(16)(17)(18)(19) , which confirm the dipping curve of early healing period after implant placement noticed in most of the clinical studies by using this device or the conventional drilling ways. the results of this study showed 65.32 69.78 0 20 40 60 80 is q v a lu e isq at baseline isq at 16 weeks 0 10 20 30 40 50 60 70 80 90 100 baseline (primary stability at surgery) 8 weeks 16 weeks 76.19 61.9 83.3 19.05 26.19 14.29 4.76 11.9 2.38 chart title high isq medium isq low isq j bagh college dentistry vol. 29(1), march 2017 localization of maxillary oral and maxillofacial surgery and periodontics 101 that all the inserted implants at the time of surgery achieved a good primary (initial) stability with a mean value (74.32) isq. and if we set the high threshold value at (70) isq, 32 (76.19%) of the inserted implants achieved high primary stability isq values with a range of (7085) isq, and 8 (19.05%) achieved a medium (6069) isq values with a range of (67-69) isq with a mean (68.25) isq, and these results are comparable with other clinical studies using piezoelectric device for implant site preparation.(11)(18)(12)(19) this high primary stability values can be explained by the fact that piezoelectric device is more delicate instrument and less traumatic to the bone, with less pressure and less vibration during the osteotomy of the implant beds, and the achievement of this high value may explaine the excellent survival rate (100%) in this study. many studies support this explanation and suggest that primary stability may be useful predictor for osseointegration and the surgical technique is one of the important factors that have influence on the primary stability.(20)(21)(22) comparing the isq values related to the primary stability in this study and the stability after the two following successive intervals with two recent studies on a sample of iraqi patients using conventional drilling osteotomy (23) with a slight difference follow-up time, showed that all the isq values were superior (higher) than that recorded by those aforementioned recent iraqi study which can denote that the use of piezoelectric device (ultrasonic implant site preparation) as an alternative and useful method for the instillation of dental implants. after 8 weeks although the number of implants still achieving high (70 isq) decreased and although the differences were non-significant but the number of implants with medium isq values increased to eleven (p≤0.005) but the isq values for those implants with medium values remained with a relatively high isq with a mean value of (65.27) isqs, and this value according to many clinical studies is regarded as an indicator for immediate or early immediate loading protocols.(24)(25)(26)(27) at 16 weeks (at the end of the observation period) comparing the results of this study with other clinical studies using the piezoelectric device and rfa for the recording of isq, the final implants stability showed different patterns and results (values). parts of these studies (11)(12)(18)(19) show progressive increase in the isq values canullo et al (19) which in contrast with our study and with other studies(11)(12)(17) follows the ordinary regular increase of the isq values during the healing process period in dental implants and this pattern was consistent with the first part (during the 8 weeks) of this study and in disagreement with the final part when there was a sharp elevation (p= 0.000) in the mean isq values reading from 72.62 to 76.68 isq. on the other hand the final isq values of the stability in accordance with many clinical studies (11)(12)(19) in which the recorded final isq values, (almost with the same post-operative follow-up period) surpassed (higher) the initial primary stability, and this result may be related to the increase of neo-osteogenesis, increase in bone stiffness, density and to better osseous response in the bone around implants using piezoelectric bone surgery according to many radiological, histomrphological and experimental studies (8)(10)(29) and in disagreement with blaszczyszy et al (18) wherein they recorded inferior value in the mean isq value of the initial stability to the overall final mean isq value readings in other studies, and this could be explained by the fact there was obvious differences between these studies regarding, the patients samples, the follow up period, the piezoelectric device tips used, the statistical analysis methods and the variables included, so further clinical studies with large sample, better standardization, close monitoring of the isq values postoperatively seem to be crucial. within the limitation of this study, regarding the small sample size and the short post-surgical follow up period, piezosurgery is a safe and predictable tool in implant sites preparation and could be used as alternative method to traditional techniques. 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preparation techniques: twist drills versuspiezosurgery. asingle‐blinded, randomized, controlled clinical trial. clin implant dent relat res. 2013 apr 1;15(2):188-97. 12. da silva neto ut, joly jc, gehrke sa. clinical analysis of the stability of dental implants after preparation of the site by conventional drilling or piezosurgery. br j oral maxillofac surg. 2014 feb 28; 52(2):149-53. 13. vercellotti t, stacchi c, russo c, rebaudi a, vincenzi g, pratella u, baldi d, mozzati m, monagheddu c, sentineri r, cuneo t. ultrasonic implant site preparation using piezosurgery: a multicenter case series study analyzing 3,579 implants with a 1-to 3-year follow-up. int j periodontics restorative dent. 2014 34 (1), 11-18 14. berglundh t, abrahamsson i, lang np, lindhe j. de novo alveolar bone formation adjacent to endosseous implants. clinic oral implants res. 2003 may 1; 14(3):251-62. 15. sençimen m, gülses a, özen j, dergin c, okçu km, ayyildiz s, altug ha. early detection of alterations in the resonance frequency assessment of oral implant stability on various bone types: a clinical study. j oral implantol. 2011 aug; 37(4):411-9. 16. sennerby l. resonance frequency analysis for implant stability measurmernt. a review 2015; 1:111 17. baker ja, vora s, bairam l, kim hi, davis el, andreana s. piezoelectric vs. conventional implant site preparation: ex vivo implant primary stability. clin oral implants res. 2012 apr 1; 23(4):433-7. 18. blaszczyszyn a, heinemann f, gedrange t, kawala b, gerber h, dominiak m. immediate loading of an implant with fine threaded neck–bone resorption and clinical outcome of single tooth restorations in the maxilla. biomed tech (berl). 2012 feb 1; 57(1):3-9. 19. canullo l, peñarrocha d, peñarrocha m, rocio ag, penarrocha‐diago m. piezoelectric vs. conventional drilling in implant site preparation: pilot controlled randomized clinical trial with crossover design. clin oral implants res. 2014 dec 1; 25(12):1336-43. 20. meredith n. assessment of implant stability as a prognostic determinant. int j prosthodont.1998 dec; 11(5):491-501. 21. friberg b. surgical approach and implant selection (brånemark system) in bone of various densities. appl osseointegration res. 2002;3:9-16. 22. crespi r, capparè p, gherlone e, romanos ge. immediate occlusal loading of implants placed in fresh sockets after tooth extraction. int j oral maxillofac implants. 2006 dec; 22(6):955-62. 23. ibraheem ns, al-adili ss. assessment of dental implant stability during healing period and determination of the factors that affect implant stability by means of resonance frequency analysis (clinical study). journal of baghdad college of dentistry. 2015; 27(3):109-15. 24. ostman po, hellman m, wendelhag i, sennerby l. resonance frequency analysis measurements of implants at placement surgery. . int j prosthodont. 2005 dec; 19(1):77-83. 25. bornstein mm, heynen g, bosshardt dd, buser d. effect of two bioabsorbable barrier membranes on bone regeneration of standardized defects in calvarial bone: a comparative histomorphometric study in pigs. j periodontal. 2009 aug; 80(8):128999. 26. östman po, wennerberg a, albrektsson t. immediate occlusal loading of nanotite™ prevail® implants: a prospective 1‐year clinical and radiographic study. clin implant dent relat res. 2010 mar 1; 12(1):39-47. 27. bogaerde lv, pedretti g, sennerby l, meredith n. immediate/early function of neoss implants placed in maxillas and posterior mandibles: an 18‐month prospective case series study. clin implant dent relat res. 2010 may 1; 12(s1):e83-94. 28. harel n, moses o, palti a, ormianer z. long-term results of implants immediately placed into extraction sockets grafted with β-tricalcium phosphate: a retrospective study. j oral maxillofac surg. 2013 feb 28; 71(2):e63-8. 29. preti g, martinasso g, peirone b, navone r, manzella c, muzio g, russo c, canuto ra, schierano g. cytokines and growth factors involved in the osseointegration of oral titanium implants positioned using piezoelectric bone surgery versus a drill technique: a pilot study in minipigs. j periodontol. 2007 apr; 78(4):716-22. 30. stübinger s, stricker a, berg bi. piezosurgery in implant dentistry. clin cosmet investig dent. 2015; 7:115. j bagh college dentistry vol. 29(1), march 2017 localization of maxillary oral and maxillofacial surgery and periodontics 103 الخالصة حديث الصنع يستخدم للتغلب و هو نظامpiezosurgery تعتبر طريقة العملية الجراحية احد العوامل المؤثرة على عملية االندماج العظمي. ان استخدام جهازخلفية: للعظم تتسم قطععملية لخلق الصوتية فوق بالموجات الصغيرة االهتزازاتوهذا الجهاز يستخدم يدية في عملية الزراعةلعلى المعوقات التي تواجه الطريقة التق بها المحيطة األنسجةبالدقة واالنتقائية في القطع بدون قطع تلقى المشتركون . وقد سنة،( 18-81) بين أعمارهم تتراوح إناث،( 81) و الذكور من( 6) مريضا،( 42) مجموعه ما الدراسة هذه في ساهم :طريقة البحث والمواد بما مريض لكل الجراحة قبل التقييم تطبيق تم. .piezosurgery جهازب استخدام االدوات الخاصة طريق عن الغرسات هذه من كل أعدت ،غرسة( 24) مجموعه ما بعد والشعاعي السريري التقييم تطبيق تم. أسبوعا 86 وفي أسابيع، 1 ،يوم الجراحة في للغرسات isq قياس تم. شاملالشعاعي ال السريري الفحص ذلك في تحضيرها.ل piezosurgeryالغرض من هذه الدراسة هو تقييم نسب النجاح و التغير الحاصل لثبات الزرعه والتي استخدم جهاز .مريض لكل الجراحية العملية البقاء ومعدل قد اندمجت عظميا( 24) الغرسات جميع ان لوحظ أسبوعا 86 وبعد المتابعة، فترة اكملت جميعها غرسة( 24) تلقى المرضى من( 42: )النتائج أسابيع 1 في isq قيمة متوسط كان ،(6.24± 22.44) األساس في isq المتوسطة القيمة وكانت(. ٪1) مضاعفات الو فشل، أي بدون ٪811للغرسات والنجاح الشفاء فترة خالل ثبات الزرعات معدل في التغييرات. ان isq (76.68 ± 7.35) ثبات الزرعات قيمة متوسط كان أسبوعا 86 وبنسبة( ±1.11 24.64) isq> 70 حققت الغرسات التي ،(٪14.4) 41 كان isq≥70 حققتعدد الغرسات التي 86ال األسبوع في .(p≤0.05) ثبات الغرسة في كبيرة زيادة أظهرت (٪86.2) 2 كان في ثبات الغرسات عند مبكر تحول إلى ويؤدي الشفاء وقت من وتقللاظهرت نتائج ثبات عالية piezosurgery الزراعة باستخدام جهاز نتائجان : االستنتاجات ..مستعدة piezosurgery بواسطة تحضير موقع الغرسات .، تحليل الترددات الرنينية, الغرسات السنية، معدل النجاح piezosurgeryالكلمات الرئيسية: j bagh college dentistry vol. 26(1), march 2014 periodontal health oral and maxillofacial surgery and periodontics 128 periodontal health status and salivary parameters in pregnancy leka'a s., b.d.s. (1) leka'a m. ibrahim, b.d.s., m.sc. (2) abstract background: pregnancy is considered a major risk factor for development and progression of periodontal disease. there are hormonal changes in both estrogen and progesterone hormones in addition to bacterial effect and poor oral hygiene that will enhance development of periodontal disease in pregnant women. materials and methods: seventy subjects were enrolled in the study, the subjects with an age range (20-35) years old without any history of systemic disease. the subjects were divided into 20 non-pregnant women they represent the control group (g i), 30 pregnant women with gingivitis (gii) and 20 pregnant women with periodontitis (giii).all periodontal parameters (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level) were recorded and 5ml of unstimulated saliva was collected for each subject. the collected saliva was centrifuged and clear supernatant was collected and kept frozen until biochemical analysis of salivary enzymes which included alp, ldh and salivary calcium. results: no significant difference in the mean value of salivary alp between gi and g ii, while there is high significant difference between gi and giii. there was significant difference in the salivary ldh and ca levels between control group and group ii, while there is highly significant difference of salivary ldh and ca between group i and group iii.there was significant difference in the number of bleeding sites, and probing pocket depth (ppd) among all groups. there was increase in the total number of all scores of ppd (score 1,2 and 3) gii and giii compared to gi. conclusions: thepregnant women revealed more periodontal disease conditions (gingivitis and periodontitis) due to hormonal changes superimposed with microbial infection. salivary enzymes (alp, ldh) and salivary calcium are considered as good biochemical markers of periodontal tissue destruction and can be used to evaluate the effect of pregnancy on periodontal health status. keywords: pregnancy; saliva; alkaline phosphatase; lactate dehydrogenase; calcium; periodontal disease. (j bagh coll dentistry 2014; 26(1):128-133). الخالصة تأثير البكتيريا وعدم امل خطر رئيسي لتنمية وتقدم اإلصابة بأمراض اللثة نتيجة التغيرات الهرمونية في كل من االستروجين والبروجسترون هرمون باإلضافة إلى : يعتبر الحمل عخلفية االهتمام بصحة الفم و األسنان عند معظم النساء الحوامل مما يؤدي إلى تعزيز تنمية أمراض اللثة في النساء الحوامل. ( سنة من دون أي تاريخلإلصابةباإلمراضالجهازية. تم تقسيم النساء إلى مجموعتي الدراسة ) 53-02سبعون امرأة تم إدخالهم في الدراسة تتراوح أعمارهم بين ) المواد والطرق: حاملوهي تمثل المجموعة الضابطة(.وسجلت جميع المعلمات للثة )مؤشر امرأة غير 02امرأة حامل مع التهاب دواعم السن( ومجموعة المراقبة ) 02أمرأة حامل مع التهاب اللثة، 52 عينة اللعاب للطرد المركزي وجمع اللعاب البالك، مؤشر اللثة، نزيف في اللثة، سبر عمق الجيب وفقدان المرفقات السريرية( وتم جمع عينة اللعاب غير المحفز لكل امرأة. تم تعريض وقت التحليل لكل من اإلنزيمات اللعابية والكالسيوم.الطافي الواضح وتم تجميدها إلى بطة ومجموعة انزيم في اللعاب بين المجموعة الضابطة والحوامل مع التهاب اللثةذو فرق غير معنوي، بينما هناك فروق معنوية عالية بين المجموعة الضا alp متوسط : أنالنتائج والكالسيوم بين المجموعة الضابطة ومجموعة الحوامل مع التهاب اللثة، بينما هناك فرق كبير ldhر في مستويات اللعابية في انزيمهناك اختالف كبي ,الحوامل مع التهاب دواعم الس المجموعة الضابطة بين pliاللعابية وامالح الكالسيوم بين المجموعة الضابطة ومجموعة الحوامل مع التهاب دواعم السن.وجد فروق ذات داللة عالية في مؤشر لوحة ldhمن ان هناك ,كبير للغاية في مؤشر لثويومجموعة الحوامل مع التهاب اللثة، بينما هناك فرق كبير عالي بين المجموعة الضابطة ومجموعة الحوامل مع التهاب دواعم السن.هناك فرق ( بين جميع الفئات. كان هناك زيادة في العدد اإلجمالي من كل ppdتم العثور علىاختالف كبير في عدد من مواقع النزيف، وكان هناك أيضا اختالف كبير في سبر عمق الجيب ( مقارنة مع 5و 2،0النتيجة ) ppd( في الحوامل مع التهاب اللثة مقارنة مع المجموعة الضابطة. الحوامل مع مجموعة اللثة تظهر أيضا زيادة 5و 2،0)درجة ppdالدرجات من المجموعة الضابطة. التأثيراتالميكروبية التي من كشفت مجموعة الحوامل تدميرانسجة اللثة وفقدان العظم السنخيأكثر من مجموعة النساء غير الحوامل بسبب التغيرات الهرمونية باإلضافةإلى اجات:االستنت alp ،ldhشأنها تعزيز التنمية والتقدم في تدمير األنسجة اللثوية لذلك تعتبر اإلنزيمات اللعابية introduction periodontal disease, including gingivitis and periodontitis, is considered to be one of the most common diseases among population and, if left untreated, can lead to tooth loss. the main cause of periodontal disease is bacterial plaque although many other factors such as hormonal changes, diabetes, poor nutrition, smoking, and stress may affect the initiation and progression of gingival and periodontal diseases. the development of the common periodontal diseases depends mainly on human behavior, and the control of these diseases is greatly supported by the fact that the etiological factors are well documented (1). (1) master student, department of periodontics, college of dentistry, university of baghdad. (2) professor, department of periodontics, college of dentistry, university of baghdad. pregnancy is accompanied by an increase in the levels of both progesterone and estrogen which, by the third trimester, reaches levels 10-30 times than seen during the typical menstrual cycle. changes in the gingiva include an increase inflammation that usually starts during the second to third month of pregnancy and increases in severity through the eighth month, where it decreases along with the abrupt decrease in hormone secretion (2). study has been suggested that women who experience periodontal disease during pregnancy may be at risk of having a premature or low birth weight baby. the periodontal disease affects pregnancy outcomes. and he suggested that treating periodontitis during pregnancy may reduce the risks of a preterm birth. preventing gingival problems from developing during the j bagh college dentistry vol. 26(1), march 2014 periodontal health oral and maxillofacial surgery and periodontics 129 stresses of pregnancy also appears to be important in improving the health of mother and baby (3). saliva, an important physiologic fluid, containing a highly complex mixture of substances, is rapidly gaining popularity as a diagnostic tool. in the field of periodontology, traditional clinical criteria are often insufficient for determining sites of active disease, for monitoring the response to therapy, or for measuring the degree of susceptibility to future disease progression. saliva, as a mirror of oral and systemic health, is a valuable source for clinically relevant information because it contains biomarkers specific for the unique physiologic aspects of periodontal diseases (4). host responses to periodontal disease include the production of different enzymes that are released by stromal, epithelial or inflammatory cells. there are important enzymes associated with cell injury and cell death like aspartate and alanine aminotransferase (ast, alt), lactate dehydrogenase (ldh), creatinekinase (ck), alkaline and acidic phosphatase (alp, acp), gamaglutamiltransferase (ggt). changes in enzymatic activity reflect metabolic changes in the periodontium in inflammation (5). alkaline phosphates intracellular enzyme present in most of the tissues and organs, particularly in bones. their increased activity is probably the consequence of the destructive processes in the alveolar bone, in the advanced stages of the development of periodontal disease remarkable increased activity of alp in, and after periodontal therapy, the activity of enzyme was restored to the value found in healthy persons. alp is enriched in the membranes of mineralizing tissue cells (e.g., osteoblasts) and is also present in polymorphonuclear leukocyte (pmn) granules. alp is produced by some oral bacteria, including gram-negative microorganisms found in the sub gingival plaque,(6). lactate dehydrogenase enzyme is indicator of a high level of cellular damage and it is increased activity in saliva is a consequence of their increased release from the damaged cells of soft tissues of periodontium and a reflection of metabolic changes in the inflamed gingival (7). calcium (ca) is the ion that has been most intensely studied as a potential marker for periodontal disease in saliva. a higher concentration of ca detected in unstimulated saliva from the periodontitis patients. the authors concluded that increase ca concentration in saliva was characteristic of patients with periodontitis. nevertheless, the importance of the salivary ca concentration in relationship to progression of periodontal disease is not defined. considering the distribution of ca, this ion appears to hold promise as a marker for periodontal disease (8). materials and methods subjects included in the study were selected from patients attending to al-mustafa primary health center and to al-batool hospital. seventy subjects were enrolled in the study, the subjects with an age range 20-35 years old. they were carefully informed about the aim of the investigation and they were free to accept or refuse to be examined. each participant received complete medical and dental history to determine their suitability to the study and all of them had no history of systemic disease all subjects had at least 20 teeth. the sample include control group (gi) which included twenty non-pregnant women. study group which included 50 pregnant women in second trimester and subdivided into: group ii which included thirty pregnant women in second trimester with gingivitis.group iii which included twenty pregnant women in second trimester with periodontitis.unstimulated (resting) whole saliva was collected before the clinical examination. a sample was collected after an individual was asked to rinse her mouth thoroughly with water. to insure the removal of any possible debris or contaminating materials we waited for 1-2 min for water clearance. the collected saliva was centrifuged at 3500 rpm for 20 minutes and then the centrifuged clear supernatant saliva was collected by micropipette into eppendroftubes and kept frozen and store at20`c until biochemical analysis. samples containing blood were discarded. aii periodontal variables were recorded on four sites (mesial, buccal, distal and lingual or palatal for all teeth except the third molar which was excluded. interproximal areas were probed from buccal part of the tooth with probe tip parallel to long axis of tooth and positioned inter proximally as close as possible to the contact point; measuring was made to the nearest millimeters. the assessment of dental plaque was made according to the plaque index (9). the gingival condition was assessed using the criteria of gingival index system. bleeding on probing done by using a blunt periodontal probe was inserted to the "bottom" of the periodontal pocket and is moved gently along the tooth (root) surface. if bleeding occurs within 30 second after probing the site was given as positive score (1), and a negative score (0) for the non-bleeding site (10). probing pocket depth were estimated by using william probe and use a scale for ease of estimation, it involve the following criteria. j bagh college dentistry vol. 26(1), march 2014 periodontal health oral and maxillofacial surgery and periodontics 130 score 0: those include depth from 1-3 mm. score 1: those include depth >3-5mm. score 2: those include depth >5-7 mm. score 3: those include depth >7 mm. clinical attachment level (cal): this was assessed by measuring the distance from comentoenamel junction (cej) to the base of the pocket. attachment level was passed by using williams’s periodontal probe (11) to measure the distance in mm from free gingival margin (fgm) to the cej and measure the distance from fgm to the base of the pocket at each site. the attachment level was obtained by subtracting the first measurement from the second one (12). biochemical assay for enzyme analysis used kits manufactured by biolabo which is one of the french leaders of reagents for medical biochemistry of alp. atomic absorption spectrophotometer for medical biochemistry of ca was used human germany kit for ldh. statistical analysis. the data were processed and analysis using the statistics package social sciences (spss.is.under window xp and excel 2003). both descriptive and inferential statistics were used. results plaque index (pli): the descriptive statistics for plaque index was shown in table (1) it was clearly shown that the means of plaque index were elevated in group iii compared with group i and ii.the mean and sd were 2.34±0.192 in group iii , while in group i and ii they were 1.275±0.228, 2.123±0.291 respectively. inter-group comparison of plaque index using student t-test revealed a high significant difference between group i and group ii and between group i and iii where the p-value was < 0.05,while there was no significant difference between ii and groupiii at p-value < 0.01as shown in table (2). gingival index (gi): the mean and sd of gingival index was described in table (3),the mean of gingival index in group iii were higher compared with group i and ii.it was 2.092± 0.370 in group iii, 1.763±0.4 in group ii and 0.355±0.176 in group i inter –group comparison of gingival index using t-test shown in table (4). comparison between group i and group ii and between group i and iii was high significant, while the comparison between group ii and group iii was significant. bleeding on probing (bop): the number and percentage of bleeding on probing for all groups were shown in table (5). the percentage of bleeding sites in group ii was (63.592%), while in group iii was (76.865%). statistical analysis using chi-square test revealed significant difference of b.o.p scores among all groups as shown in table (6). probing pocket depth (ppd): the number and percentage of probing pocket depth for all groups shown in table (7). the group i shown 100% score 0 percentage of probing pocket depth , while group ii shown (50.645%) score o and (46.033%) score 1 and (3.322%) score 2 percentage of pocket depth,whille group iii shown (37.810%) score 0 , (60.086%) score 1 , (1.195%) score 2 and (0.909% ) score 3 percentage of probing pocket depth chi–square test was applied on the ppd scores (0, 1, 2, and 3) for all groups and the result revealed significant difference as shown in table (8). clinical attachment level (cal): the table (9) illustrates the number and percentage of clinical attachment level for group iii, in group iii the percentage of score 1 was (24.906%).the percentage of score 2 was (47.466%), the percentage of sites score 3 was (26.720%), while the percentage of score 4 was (0.908%) biochemical analysis: analysis of alkaline phosphates level (alp): the descriptive statistic of alp for all groups was shown in table (10). the mean of alp (iu/l) was higher in group iii compared to groups i and ii .the highest mean of alp was found in group iii (60.725± 1.929) and the lowest mean was in group i (24.451± 2.472),while the mean of alp in group ii was (25.7±1.835). inter-group comparison of the mean alp shown in table (11). comparison of the mean alp showed that there was a non significant difference between group i and ii, and high significant difference between group i and iii, and between group ii and iii. analysis of lactate dehydrogenase level (ldh): the descriptive statistics of ldh for all groups were shown in table (12). the mean of ldh (iu/l) was higher in group iii compared to groups i and ii. the highest mean of ldh was found in group iii (86.279± 2.970) and the lowest mean was in group i (33.319±1.688),while the mean of ldh in group ii was (43.207± 1.388). inter-group comparison for the mean of ldh was shown in table(13).comparison of the mean ldh showed a significant difference between group i and ii, while a highly significant difference found between group i and iii , and group ii and iii. j bagh college dentistry vol. 26(1), march 2014 periodontal health oral and maxillofacial surgery and periodontics 131 analysis of calcium level (ca): the descriptive statistics of ca for all groups were shown in table (14),. the mean of ca (iu/l) was higher in group i and ii compared to group iii. the highest mean of ca was found in group i (4.505± 0.356) and the lowest mean was in group iii (1.68± 0.436), while the mean of ca in group ii was (3.334± 0.540). inter-group comparison for the mean of ca was shown in table (15). comparison of the mean ca showed a significant difference between group i and ii. on the other hand there was a highly significant difference between group i and iii, and between group ii and iii. discussion this study demonstrates the effect of pregnancy on periodontal health status and on the level of these enzymes in saliva as these enzymes is increasingly released from the damaged cells of periodontal tissues into the gingival crevicular fluid and saliva. (13)suggested that the period between weeks 12 and 28 of pregnancy can be characterized by increased susceptibility to plaque bacteria and an inflammatory response in the gingival.estrogen firstly decreases collagen production and keratinization of gingival epithelium and secondly induces proliferation of fibroblasts and decreases the collagen and no collagen proteins, blocks the turnover of the gingival tissue, thereby reducing the capacity of gingival tissue to repair (14).that leads to increase in the permeability of the epithelial barrier and an increased response to plaque bacteria (15). gingivitis due to accumulation of plaque was the most characteristic periodontal condition in this sample and was related to professional level, level of education, and previous periodontal maintenance. these results illustrate the importance of establishing periodontal preventive measures for pregnant women, even though their demographic and clinical characteristics do not differ from those of the general population (16).during pregnancy, progesterone levels increase 10-fold and estrogen levels 30-fold compared to those observed on menstrual cycle due to their continuous production, physiological changes in metabolism include oral microbial species, immune response and cell metabolism. the increase in progesterone results in greater vascular permeability, gingival edema, crevicular fluid levels and prostaglandin production, which may lead to gingival inflammation (17). the clinical indicators evaluated in this study were bleeding on probing and pocket depth without loss attachment, which indicated that this may be due to a more pronounced gingival overgrowth in the proximal surfaces of anterior teeth (18).the effect of these changes on the periodontal tissues results in increased gingival swelling. increased bleeding on probing may be seen in clinical examinations during pregnancy (19).this general increase in cal in pregnant with periodontitis group was in agreement with (20). the developing baby draws calcium from the mother's bones. the baby's calcium needs are provided by the mother's diet. when the mother's diet is not sufficient in calcium her body may try to compensate for this lack by drawing some calcium from her bones; however, her teeth will not be affected. while oral health can be affected during pregnancy, it is often because of poor oral hygiene. (21).in present study it was found that salivary alkaline phosphates level increases with increase in periodontal destruction. total amount of alkaline phosphates levels were significantly higher in periodontitis as compared to healthy and gingivitis sites, similar observations were made by (22). in this study there was significant difference between the control group and pregnant with gingivitis and highly significant difference present between the control group and pregnant with periodontitis group and this is in agreement with (23). intracellular enzyme such as ldh was increasingly released from the damaged cells of periodontal tissue into the gcf and saliva, ldh enzyme can help to monitor the progression of periodontal disease and they appear to be useful to test the activity of periodontal disease (24). thepregnant women revealed more periodontal disease conditions (gingivitis and periodontitis) due to hormonal changes superimposed with microbial infection. salivary enzymes (alp, ldh) and salivary calcium are considered as good biochemical markers of periodontal tissue destruction and can be used to evaluate the effect of pregnancy on periodontal health status. references 1albandar jm. global risk factors and risk indicators for periodontal diseases. j periodontol 2000 2002; 29: 177-206. 2al-talib z. the effects of pregnancy on the periodontal condition of young adult saudi population. j egypt dent.2008; 54: 1-11. 3american academy of periodontology (aap). epidemiology of periodontal disease (aap positonpaper). j periodontol 2005; 76: 1406-19. 4bergstrom j. pregnancy and periodontal bone loss. j periodontal 1991; 62: 242-6. 5battino m. pregnancy and sub gingival dental calculus. j clin periodontal 2005; 32: 81-8. 6calsina g, roman jm, echeverria jj. effect of pregnancy on periodontal tissues. j clin periodontol 2002; 29(8): 771-6. j bagh college dentistry vol. 26(1), march 2014 periodontal health oral and maxillofacial surgery and periodontics 132 7dawes c. how much saliva is enough for avoidance of xerostomia? j caries res 2004; 38: 236-40. 8falco ma. the life time impact of sugar excess and nutrient depletion on oral health. j gen dent 2001; 49(6): 591-5. 9loe h, silness j. periodontal disease in pregnancy. i. prevalence and severity. j acta odontol scand 1963; 21: 533-51. 10carranza fa, newman mg. clinical periodontology. 8th ed. w.b. saunders; 1996. 11george l, granath f , johansson al, anneren g, cnattingius s. pregnancy and risk of spontaneous abortion. j epidemiol 2006; 17(5): 500-5. 12griffiths gs. formation, collection and significans of gingival crevice fluid. periodontal 2000 2003; 31: 3245. 13hidalog rv. pregnancy and periodontal disease. j periodontol 2000 2003; 3: 50-8. 14holtfreter b, schwahn c, biffar r, kocher t. epidemiology of periodontal disease in the health in pomerania. j clin periodntol 2009; 36(2): 114-23. 15kaufman e, lamster ib. the diagnostic applications of salivaa review. j crit rev oral bio med 2002; 13(12): 197-212. 16kinane df, radvar m. the effect of pregnancy on mechanical and antimicrobial periodontal therapy. j periodontal 1997; 68(5): 467-72. 17kingman a, susin c, albandar jm. effect of partial recording protocols on severity estimates of periodontal disease. j clin periodontol 2008; 35(8):659-67. 18kugahara t, shosenji y, ohashi k. screening for periodontitis in pregnant women with salivary enzymes. j obstet gynaecol res 2008; 34(1): 40-6 19lee jm, garon e, wong dt. salivary diagnostic. j orthod craniofac res 2009; 21(4): 672-6. 20mese h, matsuo r. salivary secretion, taste and hypo salivation. j oral rehabil 2007; 34(10): 711-23. (ivsl). 21numabe y, hisano a, kamoi k, yoshie h,ito k, kurihara h. analysis of saliva for periodontal diagnosis and monitoring. j periodontology 2004; 40: 115-9. 22ozmeric n. advances in periodontal disease markers. j clin chim acta 2004; 343(1-2): 1-16. 23page rc, beck jd.risk assessment for periodontal disease. int dent j 1997; 47(2): 61-87. 24zhou y, wang c, yao w, et al. copd in pregnant chinese. eur respir j 2009; 33: 509-18. table 1: mean of plaque index in each group pl i g1 gii giii mean 1.275 1.275 2.34 sd ± 0.228 0.291 0.192 table 2: inter-group comparison by using t-test for mean plaque index. significance p-value t-test groups hs 0.002 1.923 group i and group ii hs 0.003 3.013 group i and group iii ns 0.133 1.306 group ii and group iii table 3: descriptive statistics of gingival index in each group. group iii group ii group i gi 2.092 1.763 0.355 mean 0.370 0.4 0.176 sd± table 4: inter group comparison of mean gingival index significant p-value t-test groups hs 0.002 1.987 group i and group ii hs 0.004 2.937 group i and group iii s 0.022 1.513 group ii and group iii table 5: number and percentage of bleeding on probing for all groups group iii group ii group i score % no % no % no 23.135 484 36.408 1184 100 2292 0 76.865 1608 63.592 2068 0 0 1 table 6: the chisquare test of bleeding on probing for all groups. significance p-value df chisquare groups s 0.021 2 29.090 group i group ii group iii j bagh college dentistry vol. 26(1), march 2014 periodontal health oral and maxillofacial surgery and periodontics 133 table 7: number and percentage of pocket depth for the groups. score 3 score 2 score 1 score 0 groups % no % no % no % no 100 2292 group i 3.322 108 46.033 1497 50.645 1647 group ii 0.909 19 1.195 25 60.086 1257 37.810 791 group iii table 8: the chisquare test of pocket depth for all groups. significance p-value df chisquare groups s 0.013 6 78.081 group i group ii group iii table 9: number and percentage of clinical attachment level of chronic periodontitis group. group iii score % no 24.906 521 1 47.466 993 2 26.720 559 3 0.908 19 4 table 10: mean and sd of salivary alp for all groups group iii group ii group i statistics 60.725 25.7 24.451 mean 1.929 1.835 2.472 sd ± table 11: inter-group comparison by using t-test for mean alp for all groups. significance p-value t-test groups ns 0.707 2.192 group i and group ii hs 0.000 5.193 group i and group iii hs 0.000 3.136 group ii and group iii table 12: mean and sd of salivary ldh for all groups group iii group ii group i statistics 86.279 43.207 33.319 mean 2.970 1.388 1.688 sd± table 13:inter-group comparison by using t-test for mean ldh significance p-value t-test groups s 0.028 2.332 group i and group ii hs 0.000 9.042 group i and group iii hs 0.000 7.072 group ii and group iii table 14: mean and sd of salivary ca for all groups. group iii group ii group i statistics 1.68 3.334 4.505 mean 0.436 0.540 0.356 sd± table 15: inter-group comparison by using t-test for mean calcium significant p-value t-test groups s 0.032 1.504 group i and group ii hs 0.000 2.338 group i and group iii hs 0.000 1.875 group ii and group iii 9.tay f.doc j bagh college dentistry vol. 25(1), march 2013 a study to compare 49 a study to compare the efficiency of different instrumentation systems for cleaning oval-shaped root canals (an in vitro study) tay h. kadhom, b.d.s. (1) walid n. al-hashimi, b.d.s., m.sc. (2) abstract background: proper cleaning and shaping of the whole root canal space have been recognized as a real challenge, particularly in oval-shaped canals.this in vitro study was conducted to evaluate and compare the efficiency of different instrumentation systems in removing of dentin debris at three thirds of oval-shaped root canals and to compare the percentage of remaining dentin debris among the three thirds for each instrumentation system. materials and methods: fifty freshly extracted human mandibular molars with single straight oval-shaped distal root canals were randomly divided into five groups of ten teeth each. group one: instrumentation with protaper universal hand instruments, group two: instrumentation with protaper universal rotary instruments, group three: instrumentation with revo-srotary instruments, group four: instrumentation withtwisted rotary files and group five: instrumentation with self-adjusting files (saf). sodium hypochlorite (3%) was used as an irrigant for all groups. after canals preparation, the roots were split longitudinally and photographed with a professional digital camera. the images of root sections were then magnified to 100x and the percentage of remaining dentin debris calculated for the apical, middle and coronal thirds by dividing the pixels occupied by debris at each third by the total pixels representing the entire area of the canal using adobe photoshop cs6. data were analyzed statistically by anova and lsd at 1% and 5% significant levels. results: both protaper hand and protaper rotary files resulted in significantly cleaner canals than revo-s and twisted rotary files at the middle and coronal thirds. the self-adjusting files produced significantly cleaner canals at the three thirds than all the other groups. the coronal and middle thirds showed a greater amount of remaining dentin debris than the apical third for all groups except a non-significant difference found between the apical and middle thirds in saf group. conclusion: the self-adjusting files allowed more efficient cleaning of oval-shaped root canals than hand and rotary instruments. key words: dentin debris, oval-shaped root canals, self-adjusting file. (j bagh coll dentistry 2013; 25(1):49-55). introduction one of the major procedural steps in endodontic treatment is to thoroughly removedebris, pulp tissue, and microorganisms from the root canal system by means of chemomechanical preparation (1). a funnel-shaped canal with a circular base is not the common configuration inrootcanal anatomy. recently, cross-sectional root canal configurations havebeen classified as round, oval, long oval, flattened, or irregular. a high prevalence of oval and long oval root canals even in the apical root canal portion has been reported. according to wu et al.(2), the prevalence of oval root canals in the apical third of human teeth is generally about 25%; in some groups of teeth such as mandibular incisors and maxillary second premolars the prevalence is greater than 50%, and in distal roots of mandibular molars the prevalence is 25%– 30%(3). (1) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. in canals with these anatomical conditions, hand and rotary instruments working in reaming motionhave been reported to leave untouched fins or recesses. in addition to harboring remnants of pulp tissue or bacterial biofilms, such recesses might also be packed with dentin chips generated and pushed therein by rotating instruments. packed debris can interfere with the quality of obturationand, in infected root canals, can harbor bacteria to serve as a potential source of persistent infection (4). the self-adjusting file (saf) (redentnova, ra’anana, israel) has been devised with the purpose of sidestepping some of the limitations of nickel-titanium (niti) rotary instruments. during its operation, the file is designed to adapt itself to the shape of the root canal, both longitudinally and cross-sectionally, providing a three-dimensional adaptation. rather than machining a central portion of the root canal into a round cross section, the saf is claimed to maintain an oval canal as an oval canal with slightly larger dimensions. hence, saf system has the potential to be particularly advantageous in promoting cleaning and shaping of ovalshaped canals (5). j bagh college dentistry vol. 25(1), march 2013 a study to compare restorative dentistry 50 in this in vitro study, different instrumentation systems were used and the cleaning efficiency was evaluated and compared to find which system is more preferable for instrumentation of oval-shaped canals. materials and methods fifty freshly extracted human mandibular molar teeth with single straight oval-shaped distal root canals collected from different specialized dental centers were used in this study. immediately after extraction, bone, calculus, stains and soft tissues on the tooth surface were removed manually with cumine scaler(6). the teeth were then stored in 10% formalin solution to provide disinfection until use and in saline solution during the experiment (7). carious tissues (when present) were removed with a low speed carbide round bur and preparation of standard access cavities performed with a high speed cylindrical diamond bur using ample water cooling(8).the distal root canals controlled visually for oval shape at the canal orifice.with aid of a digital vernier and permanent black marker, tooth length was standardized to 18 mm from the anatomic apex by cutting off part of the crown (decoronation) perpendicular to the long axis of the tooth using double-faced diamond disc with straight handpiece under water-cooling to eliminate coronal interferences and to prevent the introduction of confounding variables that might contribute to variations in the preparation procedures (9-13) and to establish a flat surface that served as a stable reference position to facilitate length measurement of the canal,instrumentation and penetration of irrigant needles(13-16).using a marker and double-faced diamond disc with straight handpiece under water-cooling, the mesial roots of all teeth were separated at the furcation area perpendicular to the long axis of the root in order to prevent superpositions in the mesio-distal direction and to facilitate manipulation of the samples (14, 17). buccolingual and mesiodistal diagnostic radiographs of each tooth were taken to confirm the presence of a single oval canal with type i morphology (13), fully formed mature apex and no signs of internal resorption, or calcification. the working length was calculated by subtracting 1 mm from the length at which a #10 k-file was just visible with 20x magnification in the apical foramen (12, 13).with aid of tray adhesive, the teeth were mounted in surgical tubes filled with silicon impression material to within 1mm apical to the cemento-enamel junction (9, 10 18). the teeth were randomly divided into five groups according to the instrumentation system used with ten teeth each. the root canal preparation was performed according to the manufacturer’s instructions of the instrumentation system used in each group. group one: manual instrumentation with protaper universal hand system (dentsplymaillefer, ballaigues, switzerland), sx was inserted to pre-enlarge the coronal two-thirds of the canals, after which they were prepared with s1, s2, f1, f2, f3 and f4 at the full working length (19, 20). these instruments were used according to the manual protaper handle motion. group two: rotary instrumentation with protaper universal rotary system (dentsplymaillefer, ballaigues, switzerland), sx was fed into the canal with a brushing outstroke motion away from the furcation area for two thirds of its blade length. s1 and s2 were used with a brushing outstroke action until the full working length was reached. f1, f2, f3 and f4 were used in sequence with pecking motions (non-brushing motions) until reaching the full working length. all protaper universal rotary files were inserted into root canals in a continuous in-and-out movement with a suitable force; they were never forced apically. files were used in a torquecontrolled electric micromotor (endo-mate dt, nsk, japan) with a 16:1 reduction contra-angle handpiece using recommended torque of (2.0 n/cm) and rotation speed of (300 rpm) (10, 17, 21, 22). group three: rotary instrumentation with revo-s classic rotary system (micro-mega, besançon, france), sc1 file was used to about two-thirds of the working length of the canal with slow and unique downward movement in a free progression and without pressure. sc2 file was used to the full working length of the canal with a progressive 3 wave movement (up and down movement). su file was used to the full working length of the canal with a slow and unique downward movement in a free progression and without pressure. as30, as35, as40, files were used to the full working length of the canal. the as instruments were used with slow and unique downward movement and without apical pressure, after using the su. the files were rotated at a constant recommended rotation speed of (300 rpm) and recommended torque of (0.8 n/cm) using a 16:1 reduction contra-angle handpiece powered by a torquecontrolled electric micromotor(endo-mate dt). j bagh college dentistry vol. 25(1), march 2013 a study to compare restorative dentistry 51 group four: rotary instrumentation with twisted files rotary system (sybronendo, orange, ca, usa), tf .08/25 was taken into the canal until it engaged dentin and then withdrew immediately. the step was repeated with the same tf file until the full working length was achieved. tf .06/30 was taken into the canal until it engaged dentin and then withdrew immediately. the step was repeated with the same tf file until the full working length was achieved. tf .06/35 and tf .04/40 were then taken to the full working length. the twisted files were rotated freely as entered the canal, advanced with a single continuous and controlled motion until the files engaged dentin, and then withdrew; they were never forced apically. the files were rotated at a constant recommended rotation speed of (500 rpm) and recommended torque of (2.0 n/cm) using a 16:1 reduction contra-angle handpiece powered by a torquecontrolled electric micromotor(endo-mate dt). during root canal instrumentation, irrigation was performed using a 5 ml luer lock disposable plastic syringe with a 28-gauge max-i-probe side-vented endodontic irrigation needle placed passively into the canal, to 2 mm from the working length without bindingafter initial instrumentation to allow easy back flow of the irrigating solution. a two ml of 3% freshly prepared sodium hypochlorite (naocl) solution was used after each instrument size, leaving the canal filled with irrigant between each instrument. canals then received a final irrigation of eight ml of the same solution after root canal instrumentation. finally, the canals were dried with protaper absorbent paper points size #f4and the access opening was sealed with a moist cotton pellet and temporary filling to block the entry of debris during sectioningand prevent contamination of the root canal space(16, 18, 23). group five: root canal instrumentation with the self-adjusting file system (figure 1), a saf 1.5 mm was inserted into the canal while vibrating and was delicately advanced apically with an intermittent in-and-out hand movement of about 3-5 mm amplitude until it reached the predetermined working length. a pecking motion of 3-5 mm allowing rotation of the file when not in contact with the canal walls; this permitted the file to slide into the canal until resistance was met. this technique allowed various paths of insertion when the asymmetrically tipped file was introduced into the canal. each saf was operated for 4 minutes per canal with continuous irrigation.the saf was operated by using a 1:1 reduction contraangle low-speed handpiece(gentle-power lux 20lp; kavo, biberach, germany)adapted with a reciprocating trans-line (in-and-out) vibrating handpiece head(rdt3, redent-nova) at a frequency of 83.3 hz. the electric micromotor (x-smart, dentsply, tulsa dental) rotation speed was set at (5,000 rpm), and a recommended torque of (1.0 n/cm) which resulted in an in-andout operation of 5,000 vibrations per minute with an amplitude of 0.4 mm. the head produces a rotational motion at 80 rpm when the file is unrestricted, and it transforms the rotational motion generated by the motor into an apicocoronal motion of 0.4 mm. this movement combined with intimate contact along the entire circumference and length of the canal and the slightly rough surface of the file removed a layer of dentin with a filing motion (abrasion action). continuous irrigation with 3% sodium hypochlorite (naocl) was applied throughout the procedure at a flow rate of 5 ml/min using a special irrigation device (vatea peristaltic pump, redent-nova) that was connected to a free-rotating irrigation hub on the file via a silicone tube. the canals were dried with protaper absorbent paper points size #f4 and the access opening was sealed with a moist cotton pellet and temporary filling to block the entry of splattering cutting debris during sectioning and prevent contamination of the canal walls (3, 12, 13). before sectioning, a permanent black marker was used to draw guiding lines horizontally at the cemento-enamel junction and longitudinally along the buccal and lingual surfaces of the distal roots. a double-faced diamond disc with straight handpiece then used for preparation of horizontal and longitudinal grooves under water cooling at the marks previously determined, preserving the inner shelf of dentine surrounding the canal. the crowns and roots were split by placing a surgical chisel in thegrooves and with slight pressure striking the chisel with a smallmallet. the longitudinal section of each root with ≤ 180° of the canal circumference was selected for study. the sections with > 180° of canal circumference would possibly interfere with total canal visualization during photography(24, 25). the chosen sections of the split roots were photographed by using a 7-megapixelnikon d40 professional digital camera (nikon corp., tokyo, japan) at a 1:1 setting and saved in a computer as tiff images with maximum resolution of 20003000 pixels. the images were then imported into adobe photoshop cs6(adobe systems incorporated,san jose, california, usa) and enlarged to 100x the original size. the root canal j bagh college dentistry vol. 25(1), march 2013 a study to compare restorative dentistry 52 area was divided into three equal thirds (apical, middle and coronal) from the apical constriction to the canal orifice with aid of superimposing lines. the remaining debris in each canal was traced and the total number of pixels occupied by the debris was reported by using the histogram function in the software program. the outline of the canal was then traced and the same feature of the software reported the total pixels occupied by the canal. percentage of the remaining debris was calculated by dividing the pixels of debris by the total pixels representing the entire area of the canal. percentage of remaining debris was calculated for the apical, middle and coronal thirds for each canal (24, 25). the data were collected and analyzed using spss (version 18) for statistical analysis. oneway analysis of variance (anova) test and least significant difference (lsd) test were used to determine whether there is a statistical difference among the groups and within group at different thirds with a significance level of p ≤ 0.05. figure 1: selfadjusting file (saf) system components. results the mean values (±sd) for the percentage of dentin debris remaining in the apical, middle and coronal thirds of root canals for five instrumentation systems are shown in table1 and figure 2. the comparison between the five instrumentation systems in removing of dentin debris at each third one-way anova test showed that there was a highly significant difference among all groups at all thirds (p< 0.01). by performing the least significant difference (lsd)test, at the apical third, no significant differences were found among protaper hand instruments, protaper rotary instruments, revo-s rotary instruments and twisted rotary files and highly significant differences were found between self-adjusting files and all the other four groups. at the middle and coronal thirds, no significant difference was found between protaper hand and protaper rotary instruments, highly significant differences were found between protaper hand instruments and both revo-s instruments and twisted files, also highly significant differences were found between protaper rotary instruments and both revo-s instruments and twisted files, no significant difference was found between revo-s instruments and twisted files and highly significant differences were found between selfadjusting files and all the other four groups. the percentage of dentin debris remaining at three difference thirds for each instrumentation system at protaper hand, protaper rotary, revo-s and twisted file groups, highly significant differences were found between apical third and both middle and coronal thirds and highly significant difference was found between middle and coronal thirds. at self-adjusting file group, no significant difference was found betweenapical and middle thirds and highly significant differences were found between both apical and middle thirds and coronal third. table 1: descriptive statistical analysis for the percentage of dentin debris remaining at three thirds (apical, middle and coronal) for five instrumentation systems thirds tested groups n mean ±sd apical protaper hand 10 1.1260 0.08178 protaper rotary 10 1.0749 0.08488 revo-s 10 1.1274 0.09961 twisted file 10 1.1395 0.10538 saf 10 0.5333 0.07305 middle protaper hand 10 2.0326 0.09900 protaper rotary 10 2.0405 0.09226 revo-s 10 2.3086 0.27426 twisted file 10 2.2915 0.13740 saf 10 0.5985 0.10834 coronal protaper hand 10 2.6805 0.19229 protaper rotary 10 2.6672 0.28932 revo-s 10 3.2187 0.09755 twisted file 10 3.1457 0.10042 saf 10 0.8298 0.08058 j bagh college dentistry vol. 25(1), march 2013 a study to compare restorative dentistry 53 figure 2: bar chart showing means percentage of dentin debris remaining. discussion the main objective of chemomechanical instrumentation is the total elimination of infected pulp tissue from the root canal. thus, proper cleansing of the canal space is considered essential for success in endodontics. to achieve these objectives, pulpal remnants as well as debris and the smear layer produced by instrumentation procedures must be removed from the root canal walls. mechanical instrumentation establishes an adequate canal shape, allowing easy access of irrigating solutions to the entire canal space and adequate obturation(26). anatomic complexities might represent physical constraints that pose a serious challenge to adequate root canal instrumentation and disinfection. an example includes the cross sectional root canal configuration, which has been classified as oval (4). the efficiency of the five instrumentation systems at apical third: the superior cleaning efficiency of saf in this study are in agreement with de-deus et al. (11), who found that there was significantly greater residual pulp tissue left after protaper system instrumentation versus saf instrumentation (21.4% vs. 9.3%, p < 0.05) at the 1-5 mm apical levels of oval-shaped root canals, the saf-treated canals had a more evident preparation of the buccal and/or lingual recesses due to: (1) the saf ability toadapt itself to the crosssection of the canal and (2) the continuous irrigation. the results of this study disagreed with paranjpe et al.(12), who found no significant difference between protaper rotary and saf in the amount of dentin debris at 1mm apical level of oval shaped root canals as well as protaper showed statistically less debris than saf at 3 mm apical level, this might be related to differences in the method of measurement, the authors used sem method in which the measurements were limited to 1 and 3 mm apical levels only, whereas in the present study, the evaluation was made for the entire apical third by using digital image morphometric analysis method. the efficiency of the five instrumentation systems at middle and coronal thirds: the results of this study showed that protaper instruments resulted in cleaner canals at the middle and coronal thirds than revo-s and twisted file. the explanations for these results could probably be attributed to (1)the sharp cutting edges of the convex triangular crosssectional design of protaper instruments and a flute design that combines multiple tapers within the shaft up to 19%, whereas revo-s and tf instruments used in this study had a constant taper of a maximum 6% and 8%, respectively. therefore, revo-s and tf removed smaller amounts of dentin in both middle and coronal thirds of the canals compared with protaper, and this may compromise the irrigation control and upward debris removal. fayyad and elgendy(27) found that protaper showed a greater amount of removed dentin than tf, especially for the middle and coronal thirds in the mesiodistal direction and for the middle third in the buccolingual direction. (2) protaper rotary shaping files (sx, s1, and s2) were used with brushing action against the buccal and lingual walls, so that a greater amount of instrumented areas created, which allowed better penetration of the irrigant and superior upward debris elimination, whereas revo-s and twisted file were used with pecking motion (non-brushing motion) according to the individual manufacturer instructions of each system. zmener et al. (28) stated that in ovalshaped canals, nickel-titanium instruments used only in a rotary motion and without lingual and buccal pressure tend to partially remove tooth structure leaving untouched areas on the opposite walls. the cutting efficiency and the ability to clean root canal walls are dependent on the inherent design of the instrument and the dynamics used during instrumentation. metzger et al.(29) showed that the saf resulted in cleaner canals walls than protaper rotary files for the coronal and midroot portions of the root canal. the difference was also pronounced in the apical third, in which rotary files failed to adequately clean the canal. these findings are in accordance with the results of this study. also j bagh college dentistry vol. 25(1), march 2013 a study to compare restorative dentistry 54 the results of the present study are in agreement with paqué et al. (30) and de-deus et al. (22), who stated that the use of saf in canals adjacent to isthmuses and oval canals resulted in much less hard-tissue debris accumulation and uninstrumented recesses cleaner of tissue debris, respectively than when protaper rotary files were used. the authors attributed these results either to avoiding rotary motion in the canals, which most probably caused debris packing when rotary files were used, or because of the continuous irrigation that was applied through the hollow file throughout the procedure or both. the mode of action of the saf may also have contributed to the results. rotary files have a rotating cutting edge that cuts off dentine particles that may be packed into the isthmus or uninstrumented recesses of oval canals. the saf on the other hand works like sandpaper: its delicately rough surface comes in close contact with the canal walls with a light pressure produced by the compressed lattice attempting to regain its original form. the in-and-out vibration that is generated by the special handpiece head serves as the motion required to remove material from the canal walls. dentine is removed as a thin powder that is continuously suspended and carried out by the flow of the irrigant. the percentage of dentin debris remaining at three difference thirds for each instrumentation system: the results of comparison the apical, middle and coronal thirds for rotary systems in this study coincide with taha et al.(7), who found that in the apical third of oval canals, rotary niti gave the best results with regard to canal cleanliness, also the apical third showed the least uninstrumented canal surfaces followed by middle and coronal thirds, respectively. the explanations of these results might be attributed to that (1) the oval shape of the canal is mostly present in the coronal and middle parts of the root, and this shape taper toward a rounder shape apically(2, 6, 7).paqué et al. (30) reported that when rotary files are used in canal with a round cross section, the dentine particles that are cut from the canal wall are carried coronally by the flutes of the file, in a manner similar to that of a common mechanical spiral drill. this removal is apparently less effective when the file has no dentine wall on one side, as is the case of a canal adjacent to an isthmus or oval canals. rather than being carried coronally or being contained and packed in the file’s flute space, the debris was most probably actively packed into the area with the least resistance, namely into the isthmuses or similar recesses in case of oval canals. it is conceivable to hypothesize that dentine particles were actively packed into softtissue remnants in these isthmuses and recesses, thus resulting in composite debris of dentine particles embedded in soft-tissue remnants, which was resistant to the common syringe-andneedle irrigation. (2) the rotating movement of niti instruments, their superelasticity, and their self-centering properties result in a nonselective cutting action along the walls of the root canal. in other words, the rotating movement of these instruments tends to maintain the instrument in the center of the canal, with the result that not all areas are being instrumented (31). rödig et al. (23)found that the flexibility of the niti instruments did not allow the operator to force them into the buccal and lingual extensions of the middle and coronal sections of oval root canals. the instruments frequently produced a circular bulge in the canal whilst the buccal and lingual extensions remained unprepared. root canal cleanliness was not good with much remaining debris and smear layer in the unprepared extensions. the results of this study are in conflict with zmener et al.(28), who observed that no significant differences in remaining debris were found between 1, 5, 10 mm levels from the working length of oval-shaped canals for the niti rotary instrumentation, this might be attributed to differences in the type of rotary instruments and the method of measurement; the author used rotary instruments with radial lands and sem method for analysis of instrumented walls only and uninstrumented areas were excluded from evaluation, also areas selected for measurements were limited to 1, 5 and 10 mm levels. in the saf group, the apical and middle thirds showed statistically better canal cleanliness than the coronal third, this could be related to the canal anatomy in which the oval shape become more pronounced in the coronal third and the use of 1.5 mm file size. reference 1. paqué f, balmer m, attin t, peters oa. preparation of oval-shaped root canals in mandibular molars using nickel titanium rotary instruments: a microcomputed tomography study. j endod 2010; 36:7037. 2. wu mk, r’oris a, barkis d, wesselink pr. prevalence and extent of long oval canals in the apical third. oral surg oral med oral pathol oral radiolendod 2000; 89:739-43. 3. paqué f, peters oa. micro-computed tomography evaluation of the preparation of long oval root canals in mandibular molars with the self-adjusting file. j endod 2011; 37:517-21. j bagh college dentistry vol. 25(1), march 2013 a study to compare restorative dentistry 55 4. siqueirajr, alves frf, almeida bm, de oliveira jcm, rôças in. ability of chemomechanical preparation with either rotary instruments or selfadjusting file to disinfect oval-shaped root canals. j endod 2010; 36:1860-5. 5. metzger z, teperovich e, zary r, cohen r, hof r. the self-adjusting file (saf). part 1: respecting the root canal anatomy; a new concept of endodontic files and its implementation. j endod 2010a; 36:67990. 6. malur mh, goud m. a preliminary analysis in the preparation and obturation of oval canals. j clinexp dent 2011; 3(3):189-92. 7. taha na, ozawa t, messer hh. comparison of three techniques for preparing oval-shaped root canals. j endod 2010; 36:532-5. 8. bernardes ra, rocha ea, duarte mah, vivan rr, de moraes ig, bramante as, de azevedo jr. root canal area increase promoted by the endosequence and protaper systems: comparison by computed tomography. j endod 2010; 36:1179-82. 9. de-deus g, garcia-filho p. influence of the niti rotary system on the debridement quality of the root canal space. oral surg oral med oral pathol oral radiolendod 2009; 108:71-6. 10. de-deus g, barino b, zamolyi rq, souza e, fonseca a, fidel s, fidel ras. suboptimal debridement quality produced by the single-file f2 protaper technique in oval-shaped canals. j endod 2010; 36:1897-900. 11. de-deus g, souza em, barino b, maia j, zamolyi rq, reis c, kfir a. the self-adjusting file optimizes debridement quality in oval-shaped root canals. j endod 2011; 37:701-5. 12. paranjpe a, gregorio de c, gonzalez am, gomez a, herzog ds, pina aa, cohenca n. efficacy of the self-adjusting file system on cleaning and shaping oval canals: a microbiological and microscopic evaluation. j endod 2012; 38(2):226-31. 13. de gregorio c , paranjpe a, garcia a, navarrete n, estevez r, esplugues eo, cohenca n. efficacy of irrigation systems on penetration of sodium hypochlorite to working length and to simulated uninstrumented areas in oval shaped root canals. intendod j 2012; 45(5):475-81. 14. plotino g, grande nm, falanga a, giuseppe ild, lamorgese v, somma f. dentine removal in the coronal portion of root canals following two preparation techniques. int endod j 2007; 40: 852-8. 15. fornari vj, silva-sousa ytc, vanni jr, pécora jd, versiani ma, sousa-neto md. histological evaluation of the effectiveness of increased apical enlargement for cleaning the apical third of curved canals. intendod j 2010; 43:988-94. 16. howard rk, kirkpatrick tc, rutledge re, yaccino jm. comparison of debris removal with three different irrigation techniques. j endod 2011; 37(9):1301-5. 17. çelikünal g, maden m, savgat a, orhan eo. comparative investigation of 2 rotary nickel-titanium instruments: protaper universal versus protaper. pathol oral radiol endod 2009; 107:886-92. 18. nielsen ba, baumgartner jc. comparison of the endovac system to needle irrigation of root canals. j endod 2007; 33:6115. 19. huang ql, zhang xq, deng gz, huang sg. sem evaluation of canal cleanliness following use of protaper hand-operated rotary instruments and stainless steel k-files. the chinese j dent res 2009; 12 (1):45-9. 20. li kz, gao y, zhang r, hu t, guo b. the effect of a manual instrumentation technique on five types of premolar root canal geometry assessed by microcomputed tomography and three-dimensional reconstruction. bmc medical imaging 2011, 11:14. 21. wu j, lei g, ming y, yu y, yu j, zhang g. instrument separation analysis of multi-used protaper universal rotary system during root canal therapy. j endod 2011; 37:758-63. 22. de-deus g, barino b, marins j, magalhães k, thuanne e, kfir a. self-adjusting file cleaningshaping-irrigation system optimizes the filling of oval-shaped canals with thermoplasticized guttapercha. j endod 2012; 38(6):846-9. 23. rödig t, hülsmann m, muhge m, schafers f. quality of preparation of oval distal root canals in mandibular molars using nickel-titanium instruments. intendod j 2002; 35:919-28. 24. sabins ra, johnson jd, hellstein jw. a comparison of the cleaning efficacy of short-term sonic and ultrasonic passive irrigation after hand instrumentation in molar root canals. j endod 2003; 29:674-8. 25. munley pj, goodell gg. comparison of passive ultrasonic debridement between fluted and nonfluted instruments in root canals. j endod 2007; 33:578-80. 26. zmener o, pameijer ch, serrano sa, hernandez sr. cleaning efficacy using two engine-driven systems versus manual instrumentation in curved root canals: a scanning electron microscopic study. j endod 2011; 37:1279-82. 27. fayyad dm, elgendy aae. cutting efficiency of twisted versus machined nickel-titanium endodontic files. j endod 2011; 37:1143-6. 28. zmener o, pameijer ch, banegas g. effectiveness in cleaning oval-shaped root canals using anatomic endodontic technology, profile and manual instrumentation: a scanning electron microscopic study. intendod j 2005; 38:356-63. 29. metzger z, teperovich e, cohen r, zary r, paque f, hulsmann m. the self-adjusting file (saf). part 3: removal of debris and smear layer – a scanning electron microscope study. j endod 2010; 36:697702. 30. paqué f, al-jadaa a, kfir a. hard-tissue debris accumulation created by conventional rotary versus self-adjusting file instrumentation in mesial root canal systems of mandibular molars. intendod j 2012; 45(5):413-8. 31. plotino g, grande nm, sorci e, malagnino va, somma f. influence of a brushing working motion on the fatigue life of niti rotary instruments. intendod j 2007; 40:45-51. j bagh college dentistry vol. 29(1), march 2017 testing different restorative dentistry 47 testing different properties of a light-cured denture base material after addition of silicon oxide nanofiller (an in vitro study) mohammed moudhaffer m ali, b.d.s., m.sc.(1) abstract background: improving the properties of heatcured and self-cured acrylic resin have been studied by many researchers. however, little studies concerned with visible light cured resin (vlcr) improved through addition of nanofiller are available. the purpose of this study was to evaluate some properties of (vlcr) after addition of sio2 nanofiller. materials and methods: sio2 nanofiller were added to (vlcr) tray material after being dissolved in tetrahydrofuran (thf) solvent. according to the pilot study 2% sio2 nanofiller addition exhibited better properties than the other percentages (1%, 3%). the main study conducted involved (100) specimens divided into 5 groups according to the test included. (20) specimens were selected for each test (10 samples for the control group and 10 samples for the experimental 2% sio2 nanofiller group). the properties investigated were transverse strength, impact strength, surface hardness, surface roughness, water sorption and solubility. scanning electron microscope (sem) and energy dispersive spectroscopy (eds) were used to assess nanofiller distribution and identification of elements. the data were subjected to descriptive statistical analysis and independent sample t-test. results: the mean value of transverse strength of experimental group increased significantly, while the impact strength of experimental group decreased significantly when compared to control group. a significant increase in surface hardness was noticed in the experimental group, while non-significant increase in surface roughness was observed. the water sorption values were decreased significantly, while a non-significant decrease in water solubility was observed in the experimental group. conclusion: addition of sio2 nanofiller to (vlcr), slightly improve the transverse strength and surface hardness, while water sorption and solubility slightly decreased. the impact strength was significantly deteriorated, while the surface roughness shows non-significant increment. key words: visible light cured resin, sio2 nanofiller, nanocomposite. (j bagh coll dentistry 2017; 29(1):47-54) introduction generally poly (methylmethacrylate) (pmma), either heat cured or self-cured is the basic material in complete or partial denture removable prosthesis. little amount of residual monomer always remains relying upon curing technique(1). a residual monomer content about 1.81-1.85% in heat polymerized pmma has been reported by hiromori(2). on the other hand, a higher amount of residual monomer left in self-cured pmma, about 2-6% has been reported. despite the fact that pmma indicate low solubility in water, remaining monomer may spread into the oral mucosa(1,3). the little amount of solubility is a consequence of non-polymerized monomer and water-dissolvable added ingredients. considerable number of patients with hypersensitivity reaction to pmma have been reported(3-5). visible light cured resins (vlcr), based on urethane dimethacrylate emerge as one of the optional material in removable prosthesis rather than the conventional pmma because of their synthetic nature are devoted from monomethacrylates(4,6). (1) assistant professor. department of prosthodontics. college of dentistry, university of baghdad. light polymerization technique do not need complicated laboratorian methods and the possibility of hypersensitivity reaction is much reduced because methylmethacrylate monomer is not present in (vlcr) (7-11). one of the pioneer in manufacturing of vlcr was known as triad based on urethane dimethacrylate (udma). it was introduced because of simple laboratory procedure, decreased bacterial colonization ,biocompatible material , patients preference , possibility to bond to another resin and obviously do not need mixing and proportioning techniques(10,11). nevertheless, its practical uses was restricted due to inherent brittleness and reduced impact strength(12). an advanced generation of methylmethacrylate free monomer was manufactured by densply trubye.n.y, known as (eclipse). this light polymerized product comprises 3 types of materials; denture base plate resin, teeth arrangement resin and teeth contouring resin. the first one will become the final denture base after light curing, the second will be utilized for setting of teeth and will be bonded to the denture base by light curing. finally, the contouring resin will be adapted on the denture base resin, arrangement resin and cervical portion of artificial teeth, afterward will be polymerized by light(6). al-mulla et al(12) conduct a study concerning some physical and mechanical properties of j bagh college dentistry vol. 29(1), march 2017 testing different restorative dentistry 48 vlcr. they found that triad (vlcr) was harder and more rigid than the conventional heat and self-cured pmma, but the impact and transverse strength exhibit less values. ali et al found that the surface hardness, flexural strength and flexural modulus of udma (eclipse) light and heat cured resins were more significant than (meliodent) heat cured and self-cured (probase cold) denture base materials(6). altaie and khamas found that the transverse strength of repaired vlcr were inferior when compared to ivomat pressured cold cured resin and conventional heat cured resin(13). akin et al concluded that vlcr possess comparable cytotoxicity to the conventional pmma, nevertheless vlcr shows less water sorption when kept in water for long time(14). in the modern biomaterial, nanotechnology has gained a considerable importance due to their characteristics properties and structures. the nano materials technology shown to be valid in 1980, '' indicating to zero-dimension, one-dimension, two-dimension, three dimension materials with a size less than 100nm''. there are usually four types of nano materials; nanofiber, nanopowder, nanoblock and nanomembrane. the nanopowder research is more extensive and its production is more advanced(15,16). the high surface energy, huge surface area, minute size and a large magnitude of surface atoms are the main characteristics features of nano materials. moreover, nano materials possess four unique and superb effects '' quantum size effect, quantum tunneling effect, surface effect and minute size effect'' (17). the addition of nano particles such as silica, clay, calcium carbonate , zirconium oxide to polymers are of interest for the researcher because of remarkable changes in physical properties (18-22). silicone oxide nanoparticles (sio2 ), otherwise called nano silica or silica nanoparticles are highly recommended in biomaterial research because of their low cost, stability, low toxicity, and the capability to be grafted with a lot of polymers (23,24).micro or nanofiller addition can significantly improve the absorption of energy and associated properties of hybrid or composite materials. nanofiller like casio3, al2o3, tio2, sio2 , zro2, clay nano particles, single walled or multi walled carbon nanotubes are of interest in nano composite engineering (24). although the improvement in the properties of vlcr are in progress, yet limited studies in the literature are available concerning the mechanical or physical performance of vlcr through addition of nanofiller. a study conducted by qasim et al (25), reported a significant increase in the impact and flexural strength of vlcr reinforced with carbon nanotubes. specimen's discoloration as the percentages increase was the main drawback of this study. the goal of the present study is to examine different properties of vlcr such as transverse strength, impact strength, surface hardness, surface roughness, water sorption and solubility after addition of sio2 nanofiller. materials and methods a pilot study was conducted to estimate the proper amount of nanofiller to be added to vlcr. silicon dioxide (sio2) nanofiller coated with epoxy (american element co. usa) was added to tray vlcr (hoffmann's germany). at first 37gm of vlcr was dissolved in 25ml of tetrahydrofuran (thf) solvent (biosolvechemicals, the netherlands) in 250ml glass beaker placed on magnetic stirrer(boeco, germany) with hot plate for 60 min (25). a digital electronic balance (kern, germany) was used to weigh the material before mixing. then, the sio2 nanofiller were added in (1%, 2%, 3%) by weight respectively, while 0% represents control group. after mixing was completed, the mixture was loaded into heat resistant plastic mold specially made for this study to make a sheet of 4mm thickness and preserved in laboratory hood away from light for one day. then the mold transferred to a dissecator for 2 days and after that dried in vacuum oven ((hysc, korea) at 60 °c for 3 hours to complete evaporation and dryness of the material. later on, the sheet was removed, kneaded well with fingers and cut into small pieces to be adapted into specially made transparent plastic mold which has 4 holes, one on each corner. two types of mold were made, the first one has 3 rectangular cavities (80mmx10mmx4mm); length, width and thickness respectively, prepared by cnc machine (computer numerical control) for impact strength. the second mold has also 3 rectangular cavities (65mmx10mmx2.5mm), for transverse strength, surface hardness and roughness. after coating the mold with vaseline, the lower transparent cover was also coated with vaseline and reassembled with the middle part, then the material was adapted carefully in the mold and excess material removed by sharp knife; then the upper cover placed on the mold and tightened with screw and nuts so that the middle part is sandwiched between the two transparent covers. the mold was transferred into the light cure chamber(kt888, china , wavelength of 400.um) so that the upper surface left for 7.5 min, then the mold was inverted and cured again for another 7.5 min(total curing time 15min). when curing was completed j bagh college dentistry vol. 29(1), march 2017 testing different restorative dentistry 49 the pattern were removed carefully, then finished and polished except samples of surface roughness was not polished. the samples of water sorption and solubility was prepared by cutting metal discs with dimensions of (50mm and 0.5mm), diameter and thickness respectively. two discs were placed on transparent plastic plate after being coated with vaseline. after that a stone was poured around the discs and on the borders with vibration, then a second transparent plate was seated upon the stone, thus the discs and stone were sandwiched between two transparent plastic plates. the two plates were tightened gently with screw and nuts. after setting of the stone, the screws were opened and the upper plastic plate removed, then the metal discs removed carefully and the resulted mold cavity surrounded by stone was coated with separating medium. after that, a little sheet of vlcr was adapted into the stone mold, then the second plastic plate was applied and tightened with screw and nuts and transferred into curing chamber and the same procedure was repeated as mention previously. according to the pilot study in which 24 samples were made, 12 for the transverse strength and the other 12 for surface hardness. three samples were made for each percentage (0%, 1%, 2%, 3%). the results shows that the 2% nanofiller has greater values than the other percentages, so the decision was to carry on the main study with 2% sio2 nanofiller. main study specimens grouping: (100) specimens were prepared for this study. the specimens were divided into (5) groups according to the test utilized in the present study. twenty samples were selected for each test (10 samples for the control and the other 10 for the 2% sio2 nanofiller. testing procedure: 1. transverse strength test: the specimens fabricated were with dimensions of (65mmx10mmx2.5mm), length, width and thickness respectively. after conditioning in water at 37°c for 48 hrs. (26), the samples were subjected to a 3 point bending test using an instron machine(laryee co., ltd. china). the stress were recorded and determination of the transverse strength follows this formula: transverse strength= 3pi/2bd2 (27), where p: is the peak load i: is the span length b: is the sample width d: is the sample thickness. 2. impact strength: specimens were kept in distilled water for 48 hrs. at 37°c before being tested. rectangular samples of dimension (80mmx10mmx4mm), were fabricated. the test was performed using izod impact testing machine (time testing machine, china) (28). the energy absorbed by the unnotched specimens was calculated using this equation: impact strength= (e/bd)x103 (27) , where e: is the impact energy absorbed in joules. b: is the width of the sample. d: is the thickness of the sample the surface of a fractured portion of randomly selected sample of the experimental group was sputter coated with gold, and tested with a scanning electron microscope (sem, ais2300c, usa). 3. surface hardness: the samples were prepared with dimension of (65mmx10mmx2.5mm), and stored in distilled water for 48hrs. at 37°c (26). shore d hardness tester (elcometer, germany) with a calibrated scale from (0-100 units) was used. the final value of this test was obtained by calculating the average value of 5 readings performed for each sample. all measurements were done by one person. 4. surface roughness: the surface roughness of (vlcr) samples were measured by profilometer device (tr200, time co. china). the sample utilized in this test were prepared with dimension of (65mmx10mmx2.5mm). later on, the samples kept in distilled water for 48hrs. at 37°c, then the test was performed by profilometer apparatus that capture surface irregularities. three readings for each sample were determined and the average value of these readings represents the final value. 5. water sorption and solubility: the vlcr samples for water sorption and solubility were fabricated as discs having a dimension (5omm ± 1mm and 0.5mm ±0.1mm), diameter and thickness respectively (26). a dissecator containing dried silica gel was utilized to dry the samples that were kept in an incubator at 37°c ± 2°c for 24hrs. after that the samples were transferred from incubator and kept at room temperature for 1h. , then weighed within accuracy of (0.0001g) using digital electronic balance. the same procedure continued daily in order to reach a constant mass ''conditioned mass'' (m1), which indicates that the loss in weight from each sample was not exceeding 0.2mg in 24hrs. subsequently, immersion of the specimens in distilled water at 37°c ± 2°c remained for one j bagh college dentistry vol. 29(1), march 2017 testing different restorative dentistry 50 week. after that, each sample was taken out from water with tweezers and blotted with clean towel for 30 seconds, remained in air for 15 seconds and weighed again, the obtained value represents m2. in order to measure the amount of water solubility, the samples were dried again in the dissecator at 37°c ±2 °c and the same procedure continues as mention before in sorption test, and the obtained value represents the reconditioned mass m3. water sorption and solubility were determined by the following formula: wsp= (m2-m1)/s (wsp=water sorption, m1= conditioned mass, m2= mass of specimen after 7 days immersion in water) wsl= (m1-m3)/s (wsl=water solubility, m1= conditioned mass, m3= reconditioned mass, s= surface area of the disc) (26). the values of the control and experimental groups were subjected to descriptive statistics and inferential statistics using independent t test with probability level at (p< 0.05). the (spss) statistical package for social sciences, v 19 was used to perform the results. results ftir, sem, eds examinations: figure.1, shows ftir spectrum of sio2 . the sio-si peak is observed at 1066 cm -1. figure.2-3, shows the ftir spectral results of vlcr before and after addition of nano sio2 . the appearance of new peak at 1049 cm-1 due to si-0-si. the (sem) examination of the fractured impact portion are shown in figure 4-5. fair homogeneity of nano silica, spherical like matrix and some pores were detected. the presence of sio2 component in the experimental sample was emphasized by (eds).si, c, o peaks were revealed on the surface of the sample as shown in figure 6. figure 1: ftir spectrum of sio2 nanofiller. figure 2: ftir spectrum of vlcr. figure 3: ftir spectrum of vlcr/ sio2 nanofiller. figure 4: sem of the fractured impact surface reinforced by 2% sio2 (50um). a, sio2 nanofiller. b, pore. figure 5: sem of the fractured impact surface re-inforced by 2% sio2 (100um). arrows show nanofiller. j bagh college dentistry vol. 29(1), march 2017 testing different restorative dentistry 51 figure 6: eds spectra showing si, c, o elements on the surface of reinforced sample by sio2 nanofiller. transverse strength, impact strength, surface hardness, surface roughness, water sorption and solubility: the means, standard deviation, minimum, maximum values of the above parameters are summarized in tables 1-6. the transverse strength of the experimental group was higher than the control group. t-test revealed a significant difference between the two groups (p< 0.05) as displayed in table 1. the impact strength of the experimental group reduced significantly when compared to controlled group as listed in table 2. for surface hardness, the experimental group recorded higher mean value than the controlled group. this increment was significant (p<0.05) as shown in table 3. table 4. , shows a non-significant increase in surface roughness of the experimental group when compared to controlled group (p>0.05). a significant decrease in water sorption was observed when 2% sio2 nanofiller added to vlcr as shown in table 5. the incorporation of 2% nano silica resulted in a non-significant decrease in water solubility as presented in table 6. table 1: descriptive summary and t-test for transverse strength (n/mm2) t-test for equality of means (d.f.=18) descriptive statistics groups p-value t-test mean difference max. min. s.e. s.d. mean n control 0% 74 57.60 1.521 4.815 64.58 10 0.032 (s) -2.515 -4.950 74.4 58.3 1.491 4.715 69.53 10 experimental 2% sio2 s: significant at p< 0.05 table 2: descriptive summary and t-test for impact strength (kj/m2) t-test for equality of means (d.f.=18) descriptive statistics groups p-value t-test mean difference max. min. s.e. s.d. mean n control 0% 7.5 5.25 0.235 0.743 6.05 10 0.014 (s) 2.731 0.8 6.25 4.25 0.174 0.552 5.25 10 experimental 2% sio2 s: significant at p< 0.05 table 3: descriptive summary and t-test for surface hardness t-test for equality of means (d.f.=18) descriptive statistics groups p-value t-test mean difference max. min. s.e. s.d. mean n control 0% 87 81.8 0.539 1.70 84.38 10 0.038 (s) -2.237 -1.70 89.6 84 0.535 1.692 86.08 10 experimental 2% sio2 s: significant at p< 0.05 table 4: descriptive summary and t-test for surface roughness t-test for equality of means (d.f.=18) descriptive statistics groups p-value t-test mean difference max. min. s.e. s.d. mean n control 0% 4.25 2.55 0.19 0.602 3.3637 10 0.770 (ns) 0.296-0.079 4.28 2.58 0.189 0.597 3.4432 10 experimental 2% sio2 ns: not significant at p> 0.05 j bagh college dentistry vol. 29(1), march 2017 testing different restorative dentistry 52 table 5: descriptive summary and t-test for water sorption (mg/cm2) t-test for equality of means (d.f.=18) descriptive statistics groups p-value t-test mean difference max. min. s.e. s.d. mean n control 0% 0.730 0.460 0.0281 0.0890 0.600 10 0.016 (s) 2.647 0.105 0.630 o.370 0.0279 0.0884 0.4949 10 experimental 2% sio2 s: significant at p< 0.05 table 6: descriptive summary and t-test for water solubility (mg/cm2) t-test for equality of means (d.f.=18) descriptive statistics groups p-value t-test mean difference max. min. s.e. s.d. mean n control 0% 0.050 0.010 0.0035 0.0110 0.0281 10 0.063 (ns) 1.980 0.00969 0.040 0.010 0.0034 0.0108 0.0184 10 experimental 2%sio2 ns: not significant at p> 0.05 discussion vlcr are accepted for many uses in restorative dentistry. however this material exhibit weak mechanical properties, especially flexural and impact strength. an attempt was made to improve some properties of this material through addition of sio2 nanofiller because previous studies mention positive changes in the physical and mechanical properties of substrates when nanofiller were added (18, 19). the resistance to breakage and stiffness can be measured by transverse strength. flexural (transverse) strength was selected in this study because it resemble the masticatory or loading forces in the oral cavity. the results of the present study shows a slight improvement in transverse strength of vlcr reinforced with 2% sio2. this might be due to nanofiller aids in the continuity of the resin matrix by filling interstitial spaces and dispersion into the polymer matrix. therefore, the shear strength between nanofiller and (udma) polymer chain will be enhanced (20, 24). another possible explanation since the modulus of elasticity of sio2 nanofiller is high, greater resistance to the applied load is expected without deformation leads to increment in flexural strength (29). moreover, sio2 nanofiller may interferes with hydrogen bonding between adjacent urethane polymer chains minimizing sliding between one chains to another as illustrated in fig.3, since additional peak appears at 1049 cm-1 due to si-o-si and disappearance of n-h at 3336.96 cm-1 .the results of this study are in agreement with the finding of qasim et al (25), who found that the mean of flexural strength of vlcr was improved when carbon nanotubes were added. for impact strength, specimens without notches were selected rather than notched one, since it was time consuming, difficult, impractical and weakened the sample. in addition to that, the brittleness of the material makes notch preparation difficult to be made( 30,31). the addition of 2% nanosilica to vlcr significantly decrease the impact strength. possibly because the (udma) stiffness attained by nanofiller addition unfortunately results in more stresses inside the resin matrix especially adjacent to the sharp and irregular borders of sio2 nanofiller which might enhance fracture by sudden impact (32), also crack propagation might be enhanced by weak bonding between polymer matrix and nanofiller treated with epoxy coupling agent. in fact, the brittle nature of the material and aggregation of sio2 nanofiller inside some pores or voids, which might resulted from polymerization or evaporation of the solvent, could facilitate the formation of micro-cracks within the urethane matrix had weakened the impact strength as revealed by( sem). in practice, a good balance between impact and flexural strength is desirable because rigid nanocomposite with improved impact strength is needed. although such a balance is important but positive correlation between such parameter is not always possible in practice. sometimes one enhanced and the other is deteriorated (33). the finding of this study disagrees with that of qasim et al (25), who found a significant increase in impact of vlcr when carbon nanotubes were added. this could be due to different material, nanofiller and measuring device. the surface hardness of the experimental samples were slightly more significant than control groups. this is possibly because of intrinsic j bagh college dentistry vol. 29(1), march 2017 testing different restorative dentistry 53 features of sio2 nanofiller such as surface hardness beside that, modulus of elasticity and polymerization shrinkage were improved when nano particles were added (34). moreover, such improvement might be due to fair distribution of sio2 nanofiller in polymer matrix which limit deformation under load. also a strong ionic inter atomic bonding gained by hard sio2 nanofiller incorporated into the matrix may enhance some needed properties such as strength and hardness (35). the non-significant increase in surface roughness of the experimental specimens may be due to slight accumulation of not symmetrical sharp nano particles on sample surface. in addition to that surface roughness was measured by profilometer which is capable to detect roughness within small micron, thus sio2 filler within nano scales might have little effect on this property. one of the significant properties of acrylic polymer is absorption of water. the polar characteristics of acrylic resin molecules may encourage water sorption slowly through period of time. high amount of water sorption leads to softening of polymer as a result of plasticizing effect that deteriorate the polymer strength (36). in the present study, sio2 nanofiller addition significantly decreases the water sorption of the experimental group. the reason could be due to micro voids or pores that encourage water to pass through and out of the polymer resin. sio2 nanofiller added might decrease the total volume of water uptakes by acrylic resin because they are insoluble in water (37). the solubility depend on the amount of soluble ingredients from acrylic resin. the initiators, plasticizer, free monomer and some pigments represents the soluble ingredients in acrylic resin (38). the results of the current study shows a non-significant decrease in the values of water solubility of the experimental groups. this is possibly because the addition of insoluble sio2 nanofiller to the polymer reduces the total amount of polymer solubility. according to the author knowledge there are no previous studies regarding water sorption and solubility of vlcr reinforced with nanofiller to compare with this study. this in vitro study showed that vlcr reinforced with 2% sio2 nanofiller significantly improve the transverse strength, surface hardness and water sorption. however, this addition lowered the impact strength significantly, suggests further laboratory studies with other nanofiller or modification in mixing technique to achieve higher improvement and better balance between flexural and impact strength. conclusion within the limitation of this study the following conclusions were drawn: 1. the transverse strength and surface hardness were increased, while the impact strength was decreased when 2% sio2 nanofiller was added to vlcr. 2. the addition of 2% sio2 nanofiller to vlcr led to a reduction in water sorption and solubility, while non-significant increment in surface roughness was noticed. references 1. wehrbe hlg, kraft kg, wostman b. clinical performance of a light –cured denture base material compared to polymethylmethacrylate – a randomized clinical study. clin oral invest 2012; 16(3):969-75. 2. hiromori k, fuji k, inoue k. viscoelastic properties of denture base resins obtained by underwater test. j oral rehabil 2000; 27:522-31. 3. tanoue n, naganok, mastumura h. use of a lightpolymerized composite removable partial 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38. debby ms, leo yy, robert kf. effect of processing method on the dimensional accuracy and water sorption of acrylic resin. j prosthet dent 1999; 81: 300-4. luma.doc j bagh college dentistry vol. 26(4), december 2014 the effect of light restorative dentistry 46 the effect of light curing tip distance on the curing depth of bulk fill resin based composites ali hussain malik, b.d.s. (1) luma m. baban, b.d.s., m.sc. (2) abstract background: this in vitro study measure and compare the effect of light curing tip distance on the depth of cure by measuring vickers microhardness value on two recently launched bulk fill resin based composites tetric evoceram bulk fill and surefil sdr flow with 4 mm thickness in comparison to filtek z250 universal restorative with 2 mm thickness. in addition, measure and compare the bottom to top microhardness ratio with different light curing tip distances. materials and method: one hundred fifty composite specimens were obtained from two cylindrical plastic molds the first one for bulk fill composites (tetric evoceram bulk fill and surefil sdr flow) with 4 mm diameter and 4 mm depth, the second one for filtek z250 universal restorative with 4 mm diameter and 2 mm depth. each spcimen was light-cured using woodpecker led curing light for 20 sec. polymerization was performed with the light tip positioned in direct contact, 2 mm, 4 mm, 6 mm and 8 mm distant from the top surface of the sample. after one day of storage in distilled water in a light proof container at 37˚c, the hardness on the bottom and top surfaces of each specimen was tested using the digital micro vickers hardness tester. then the data were analyzed statistically by anova test, lsd test and t-test. results: all experimental groups show top microhardness higher than bottom microhardness with high significant difference with all light tip distances. at 0 mm light tip distance all groups give the highest microhardness value. filtek z250 universal restorative shows accepted bottom to top microhardness ratio at all light tip distances. surefil sdr flow shows accepted bottom to top ratio only at 0, 2 and 4mm light tip distances while tetric evoceram bulk fill shows the bottom to top microhardness ratio less than the accepted value with all light tip distances. conclusion: from the results of this study we can conclude that the polymerization of bulk fill composite depends greatly on the distance from light curing tip, tetric evoceram bulk fill composite not recommended to be used as bulk fill restoration in deep cavities and need further studies, while surefil sdr flow not recommended to be used in deep cavity when curing tip distance (6-8 mm), in addition we can conclude that the thickness of the increments is more important than light curing tip distance. key words: light cure tip distance, depth of cure, tetric evoceram bulk fill composite, surefil sdr flow. (j bagh coll dentistry 2014; 26(4):46-53). introduction curing depth often considered a primary factor for clinical success of composite resin restorations, since it directly affects the physical properties of materials and longevity of restorations. the factors that may affect the curing of resin materials include those related to the restorative material, including the resin shade, amount of photo initiators, organic and inorganic matrix; the operator, including the distance and orientation of light beams and restorative technique and types of light curing units, concerning the emission spectrum and association between light intensity, period of exposure and general status of the equipment (1). energy of the light emitted from a lightcuring unit decreases drastically when transmitted through resin composite (2), leading to a gradual decrease in degree of co (1)master student. department conservative dentistry, college of dentistry, university of baghdad. (2)professor, department conservative dentistry, college of dentistry, university of baghdad. nversion of the resin composite material at increasing distance from the irradiated surface. decreases in degree of conversion compromise physical properties and increase elution of monomer and thus may lead to premature failure of a restoration or may negatively affect the pulp tissue (3). when restoring cavities with light-curing resin composites, it has therefore been regarded as the gold standard to apply and cure the resin composite in increments of limited thickness. the maximal increment thickness has been generally defined as 2 mm (4). however, restoring cavities, especially deep ones, with resin composite increments of 2 mm thickness is time-consuming and implies a risk of incorporating air bubbles or contaminations between the increments. thus, various manufacturers have recently introduced new types of resin composites, so-called “bulk fill” materials that are claimed to be curable to a maximal increment thickness of 4 mm (5, 6). j bagh college dentistry vol. 26(4), december 2014 the effect of light restorative dentistry 47 an adequate polymerization of resin composites is crucial for the ultimate success and longevity of the restoration (7). it depends not only on the irradiance of the curing light and irradiation time but also on the distance of the light tip from the tooth-restorative material (8,9). because the light intensity diminishes as the tip of the source light moves away from the resin composite’s surface, the light-curing tip unit should be in direct contact with the restoration’s surface. however, sometimes cavity design does not allow the polymerization within this distance (10). the degree of monomer conversion of resin composites can be measured using different testing techniques, either directly or indirectly. among the indirect methods, surface hardness testing has been used in many studies because it has been shown to be a good indicator of the degree of conversion (11). materials and method sample grouping: the total composite specimens were 150, divided into three groups, 50 specimens for each group named according to the type of composite used in this study. the first was tetric evoceram bulk fill, the second was surefil sdr flow and the third was filtek z250 universal restorative. then each group subdivided into five subgroups according to the light curing tip distance (0, 2, 4, 6, and 8 mm). preparation of composite resin specimens: total number of 150 specimens was obtained from two cylindrical plastic molds. the first one for bulk fill composites, tetric evoceram bulk fill, surefil sdr flow with 4 mm diameter and 4 mm depth, the second one for filtek z250 universal restorative with 4 mm diameter and 2 mm depth allowing the evaluation of the microhardness for the composite resin specimens at both top and bottom surfaces. all the composites were filled in the mold according to manufacturer instructions. each mold placed over the microscopic glass slide (1 mm thickness) and dental transparent strip, then the composite resin was loaded by injecting it directly from the tube into the mold cavity in order to reduce air voids (12). the material was packed into the mold until the cavity was overfilled. thereafter, the surface of the material was covered with another dental transparent strip and microscopic glass slide in order to produce a flat smooth surface and to prevent the formation of oxygen-inhibited layer on the surface of the samples. a (200 gm) pressure has been applied for 1 minute to expel excess material from the mold and to reduce voids (13). the glass slide was removed and the composite resin was irradiated from the top through the celluloid strip in away that the distal end of the light curing machine tip was held without pressure in contact to the celluloid strip and the center was coincident with the specimen’s long axis (14). specimens' photo-polymerization: then, each specimen was light-cured using woodpecker led curing light with light intensity 850-1000 mw/cm² which was verified every 30 specimens before polymerization by using optilux radiometer. each type of composite resin polymerized for 20 sec. according to the manufacturer instructions. polymerization was performed with the light tip positioned in direct contact, 2 mm, 4 mm, 6 mm and 8 mm distant from the top surface of the sample, the distance were standardized using plastic rings that acted as spacers (10). sample storage: immediately after curing of composite resin specimen, the celluloid strip was removed, the composite resin specimen was obtained then stored for 24 hours in a light proof container with distilled water at 37˚c to complete polymerization and inhibit any further polymerization from transient light (14). testing procedure after one day of storage in distilled water in a light proof container at 37˚c , the hardness on the bottom and top surfaces of each specimen was tested using the digital micro vickers hardness tester th714 (beijing time high technology ltd.). the specimens positioned beneath the indenter of the microhardness tester and the surface hardness of the specimens was measured with the microhardness tester using a load of 200 g load for 15 seconds to measure the vickers hardness numbers (vhn) (15). j bagh college dentistry vol. 26(4), december 2014 the effect of light restorative dentistry 48 each surface of the specimen was divided into 4 equal quadrants, on each surface, the top (turned to the light source) and the bottom (opposite of the light source) surfaces, one indentation took place for each quadrant and eight indentations were taken from each specimen. the hardness mean values were calculated for each surface (16). results the microhardness of tetric evoceram bulk fill group: means and standard deviation of the top and bottom microhardness of tetric evoceram bulk fill group at different light tip distances are summarized in (table 1). a comparison of the microhardness of tetric evoceram bulk fill group at different light tip distances by anova test (f-test and pvalue) are summarized in (table 2). table 1: descriptive statistics of the top and bottom microhardness of tetric evoceram bulk fill group at different light tip distances distance (mm) top bottom mean s.d. mean s.d. 0 51.30 2.69 38.74 4.70 2 47.21 5.90 34.99 5.77 4 46.84 3.43 30.55 5.22 6 46.22 3.39 26.89 3.43 8 45.81 4.20 21.62 4.38 table 2: comparison of the top and bottom microhardness of tetric evoceram bulk fill group at different light tip distances (anova test) surface sum of squares df mean square f-test p-value between groups top 194.30 4 48.57 2.93 0.031 (s) within groups 745.77 45 16.57 total 940.07 49 between groups bottom 1799.40 4 449.85 19.80 0.000 (hs) within groups 1022.20 45 22.72 total 2821.60 49 the top and bottom microhardness of tetric evoceram bulk fill group showed that the highest microhardness value were at 0 mm light tip distance followed by 2 mm, 4 mm, 6 mm and 8mm light tip distances respectively. statistical analysis of the data by using one-way anova test showed that there is a significant differences in the top and bottom microhardness of tetric evoceram bulk fill group at different light tip distances (p=0.031). the lsd test of the top and bottom microhardness of tetric evoceram bulk fill group at different light tip distances summarized in (table 3). table 3: lsd test shows the mean differences and the p-value of the top and bottom microhardness among tetric evoceram bulk fill groups. distance (mm) top bottom mean difference p-value mean difference p-value 0 2 4.088 0.085 (ns) 3.750 0.030 (s) 4 4.454 0.000 (hs) 8.193 0.018 (s) 6 5.079 0.000 (hs) 11.844 0.008 (hs) 8 5.487 0.000 (hs) 17.123 0.004 (hs) 2 4 0.366 0.043 (s) 4.443 0.842 (ns) 6 0.991 0.000 (hs) 8.094 0.589 (ns) 8 1.399 0.000 (hs) 13.373 0.446 (ns) 4 6 0.625 0.094 (ns) 3.651 0.733 (ns) 8 1.033 0.000 (hs) 8.930 0.573 (ns) 6 8 0.408 0.017 (s) 5.279 0.824 (ns) j bagh college dentistry vol. 26(4), december 2014 the effect of light restorative dentistry 49 the microhardness of surefil sdr flow group means, standard deviation, minimum and maximum values of the top microhardness of surefil sdr flow group at different light tip distances are summarized in (table 4). a comparison of the top and bottom microhardness of surefil sdr flow group at different light tip distances by anova test (f-test and p-value) are summarized in (table 5). table 4: descriptive statistics of the top and bottom microhardness of surefil sdr flow group at different light tip distances. distance (mm) top bottom mean s.d. mean s.d. 0 34.59 2.74 30.25 2.74 2 29.96 2.44 24.96 2.38 4 29.16 2.21 24.06 1.74 6 28.55 1.79 22.55 1.83 8 28.18 2.27 20.16 3.41 table 5: comparison of the top and bottom microhardness of surefil sdr flow group at different light tip distances (anova). surface sum of squares df mean square f-test p-value between groups top 271.18 4 67.79 12.70 0.000 (hs) within groups 240.23 45 5.34 total 511.40 49 between groups bottom 559.86 4 139.97 22.45 0.000 (hs) within groups 280.57 45 6.23 total 840.43 49 the top and bottom microhardness of surefil sdr flow group showed that the highest microhardness value were at 0 mm light tip distance followed by 2 mm, 4 mm, 6 mm and 8 mm light tip distances respectively. statistical analysis of the data by using one-way anova test showed that there is a highly significant differences in the top and bottom microhardness of surefil sdr flow group at different light tip distances (p=0.000). the lsd test of the top and bottom microhardness of surefil sdr flow group at different light tip distances summarized in (table 6). table 6: lsd test shows the mean differences and the p-value of the top and bottom microhardness among surefil sdr flow groups. light tip distances top bottom mean difference p-value mean difference p-value 0 2 4.628 0.000 (hs) 5.288 0.000 (hs) 4 5.424 0.000 (hs) 6.183 0.000 (hs) 6 6.034 0.000 (hs) 7.699 0.000 (hs) 8 6.409 0.000 (hs) 10.083 0.000 (hs) 2 4 0.796 0.427 (ns) 0.895 0.445 (ns) 6 1.406 0.036 (s) 2.411 0.180 (ns) 8 1.781 0.000 (hs) 4.795 0.092 (ns) 4 6 0.610 0.181 (ns) 1.516 0.558 (ns) 8 0.985 0.001 (hs) 3.900 0.346 (ns) 6 8 0.375 0.038 (s) 2.384 0.718 (ns) the microhardness of filtek z250 universal restorative group: means, standard deviation, minimum and maximum values of the top and bottom j bagh college dentistry vol. 26(4), december 2014 the effect of light restorative dentistry 50 microhardness of filtek z250 universal restorative group at different light tip distances are summarized in (table 7). a comparison of the top microhardness of filtek z250 universal restorative group at different light tip distances by anova test (f-test and p-value) are summarized in (table 8). table 7: descriptive statistics of the top and bottom microhardness of filtek z250 universal restorative group at different light tip distances. distance (mm) top bottom mean s.d. mean s.d. 0 112.02 10.86 94.06 9.98 2 108.89 21.59 91.20 18.38 4 105.71 12.34 87.07 10.56 6 104.49 20.91 85.29 2.75 8 84.75 4.50 68.26 5.53 table 8: comparison of the top and bottom microhardness of filtek z250 universal restorative group at different light tip distances (anova test). surface sum of squares df mean square f-test p-value between groups top 4586.85 4 1146.71 4.80 0.003 (hs) within groups 10746.02 45 238.80 total 15332.87 49 between groups bottom 4048.50 4 1012.13 8.62 0.000 (hs) within groups 5284.98 45 117.44 total 9333.48 49 the top and bottom microhardness of filtek z250 universal restorative group showed that the highest microhardness value were at 0 mm light tip distance followed by 2 mm, 4 mm, 6 mm and 8 mm light tip distances respectively. statistical analysis of the data by using one-way anova test showed that there is a highly significant differences in the top and bottom microhardness of filtek z250 universal restorative group at different light tip distances (p=0.003). the lsd test of the top and bottom microhardness of filtek z250 universal restorative group at different light tip distances summarized in (table 9). table 9: lsd test shows the mean differences and the p-value of the top and bottom microhardness among filtek z250 universal restorative groups. top bottom distance (mm) mean p-value mean p-value 0 2 3.125 0.653 (ns) 2.867 0.557 (ns) 4 6.306 0.366 (ns) 6.989 0.156 (ns) 6 7.529 0.282 (ns) 8.774 0.077 (ns) 8 27.272 0.000 (hs) 25.799 0.000 (hs) 2 4 3.181 0.648 (ns) 4.122 0.400 (ns) 6 4.404 0.527 (ns) 5.907 0.229 (ns) 8 24.147 0.001 (hs) 22.932 0.000 (hs) 4 6 1.223 0.860 (ns) 1.785 0.714 (ns) 8 20.966 0.004 (hs) 18.810 0.000 (hs) 6 8 19.743 0.006 (hs) 17.025 0.001 (hs) the bottom – top ratio the bottom-top ratio of the three groups (tetric evoceram bulk fill, surefil sdr flow and filtek z250 universal restorative) at different light tip distances are summarized in (table 10). j bagh college dentistry vol. 26(4), december 2014 the effect of light restorative dentistry 51 table 10: bottom-top ratio of different groups at different light tip distances. distance (mm) evobulk sdr z250 0 0.76 0.87 0.84 2 0.74 0.83 0.83 4 0.65 0.82 0.82 6 0.58 0.79 0.81 8 0.47 0.72 0.80 table shows that: 1. the bottom-top microhardness ratio of tetric evoceram bulk fill group was less than the accepted value (0.8) at all light tip distances (0, 2, 4, 6, and 8mm). 2. the bottom-top microhardness ratio of surefil sdr flow group was more than the accepted value (0.8) at 0, 2, and 4 mm light tip distances and less than the accepted value (0.8) at 6 and 8 light tip distances. 3. the bottom-top microhardness raio of filtek z250 group was more than the accepted value (0.8) at all light tip distances (0, 2, 4, 6, and 8mm). discussion the results of this study revealed that top and bottom microhardness at 0 mm light tip distance for all groups show the highest mean value. this may be because the distance between the light tip and the resin composite can affect the light intensity that reaches the material and that 1 mm of air reduces light intensity by approximately 10% thus interferes in the polymerization depth and degree of conversion (17-19). these findings come in agreement with the studies of sobrinho and others (20), caldas and others (21), lindberg and others (22), rakowski and others (23), ergun and others (24) who stated that the resin composite polymerization and hardness depend greatly on the distance from the curing tip. the results of this study show that the top microhardness more than the bottom microhardness at all light tip distances for all experimental groups with high significant differences. this may attributed to that at the top surface sufficient light energy reach the photoinitiator, thus starting the polymerization reaction. on the bottom surface the microhardness decreased because the resin composite has the property of dispersing the light of the light curing unit, thus when the light passes through the bulk of the composite, light intensity is reduced due to the light being scattered by filler particles and the resin matrix. it is found that 2 mm of composite are sufficient to reduce the light-inensity to 6% of its initial value (17, 20,25,26). these findings come in agreement with the studies of aguiar and others (27), nogueira and others (28) who evaluate the influence of curing tip distance on the microhardness of the resin composite and they found that the top surface showed higher hardness values than the bottom surface. while, these findings disagree with the study of miranda and others (19). in which they did not observe a statistical difference between the top surface and the base for any of the composites tested, it is believed that the results obtained in this study are justified by the thickness of the specimen made (1mm). tetric evoceram bulk fill group in this study, it clearly seen that, at 0 mm light tip distance there is significant difference in the top microhardness in comparison to 2 and 4 mm light tip distances and with high significant difference in comparison to 6 and 8 mm light tip distances. in addition, it can be seen that, at 0 mm light tip distance there is non-significant difference in the bottom microhardness in comparison to 2 mm light tip distance but with high significant difference in comparison to 4, 6, and 8 mm light tip distances. this study shows that with all light tip distances the bottom-top microhardness ratio was less than the accepted value (80%). this may be attributed to its high percentage of filler by weight which may increase the light attenuation as it pass through the bulk of the material due to light scattering, this will reduce the degree of polymerization of composite resins. another possible explanation that, the lower ratio was affected by both the resin composite increment and the high distance from the resin composite to the light source (27). as mentioned previously the light intensity reduced by approximately (6%) of its initial value when pass through the composite with 2 mm thickness, furthermore 1 mm of air reduces the light intensity by approximately (10%), thus j bagh college dentistry vol. 26(4), december 2014 the effect of light restorative dentistry 52 decreasing the polymerization effectiveness. this may explain why the bottom to top microhardness ratio was less than the accepted value. these finding come in agreement with the studies of thomé and others (10), bagnato and others (16), they found that the nanofilled composite resin did not present satisfactory microhardness at the bottom due to great light attenuation. they found that this attenuation could be explained by the high percentage of filler. an important finding of this study was that tetric evoceram bulk fill should not be polymerized with 4 mm depth in deep cavities even when the light curing tip distance was 0 mm. these finding come in agreement with study of flury and others (29), who concluded that tetric evoceram bulk fill showed no vhn value above 80% of vhn max. surefil sdr flow group from this study it can be seen that, at 0 mm light tip distance there is high significant difference in the top and bottom microhardness in comparison to 2, 4, 6 and 8 mm light tip distances. moreover, it clearly seen that only at 0, 2, and 4 mm light tip distances the bottom-top microhardness ratio was more than the accepted value (80%). this could be attributed to that the depth of cure is directly related to filler particle size in dental composite resins, the larger particle composite had the greatest depth of cure, since it was less affected by light scattering (20). in addition the presence of tegdma in the resin, which reduces the resin viscosity and increase the reactivity of the monomers (30). another possible explanation is due to that the photoactivation at 6 mm light tip distance led to a decrease of about 50% in the amount of irradiance reaching the material’s surface. coincidentally, for the 6 mm distance, the irradiance about half of the irradiance for the 0 mm distance, this light dispersion yielded to a loss of energy dose and probably promoted a lower camphorquinone excitation) and a polymer chain formation with lower crosslinks (31, 32, 33) thus, there will be more space for solvent molecules to diffuse inside the polymer network, making the polymer more susceptible to the plasticization effect of solvent (34). these findings come in agreement with the study of miranda and others (19) who concluded that the curing tip distance affect the degree of conversion of composite resin only when cured to 6mm. an important finding of this study was that surefil sdr flow should not be polymerized with 4 mm depth when the light curing tip distance was 6 mm or more. filtek z250 universal restorative group in this study, it clearly seen that, at 0 mm light tip distance there is non significant difference in the top microhardness in comparison to 2, 4, and 6 mm light tip distances but with high significant difference in comparison to 8 mm light tip distance. while at 2 mm light tip distance there is non significant difference in comparison to 4, and 6 mm light tip distances but with high significant difference in comparison to 8 mm light tip distance. in addition it can be seen that with all light tip distances the bottomtop microhardness ratio was equal or more than the accepted value (80%). this could be attributed to its high filler content and the thickness of the increment (2mm) which allows the polymerization light to reach the bottom surface better than the bulk increments (4mm) (28,35). these findings come in agreement with chung (36), nogueira and others (28), han and others (37) they found that increased concentration of filler particles improves hardness and depth of cure of lightcured composites. an important finding of this study was that filtek z250 universal restorative could be polymerized with 2 mm depth even when the light curing tip distance was 8 mm. therefore, the thickness of composite filling material is more important than the light curing tip distance. references 1. baharav h, brosh t, pilo r, cardash h. effect of irradiation timeon tensile properties of stiffness and strength of composites. j prosthet dent 1997; 77: 471-4. 2. murphy dg, price rb, dérand t. light energy transmission through cured resin composite and human dentin. quintessence int 2000; 31: 659– 67. 3. achilias ds and sideridou id. elution study of unreacted bis-gma, tegdma, udma, and bis-ema from light-cured dental resins and resin composites using hplc. j biomed mater res b appl biomater 2005; 74: 617–26. 4. cardash hs, pilo r, oelgiesser d. a survey of output intensity and potential for depth of cure among light-curing units in clinical use. j dent 1999; 27:235–41. 5. dentsply product specification. surefil sdr flow. dentsply caulk, milford, de, usa; 2011. 6. ivoclar vivadent scientific documentation. tetric evoceram bulk 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contemp dent pract 2008; 9: 43-50. 34. ferracane jl. pfeifer cs, braga rr. pulse-delay curing: influence of initial irradiance and delay time on shrinkage stress and microhardness of restorative composites. oper dent 2006; 31: 6105. 35. lee ib, kwon y, ferracane j. effect of layering methods, composite type, and flowable liner on the polymerization shrinkage stress of light cured composites. dent mater 2012; 28: 801-9. 36. chung kh. the relationship between composition and properties of posterior resin composites. j dent res 1990; 69:852-6. 37. han jl, lin sp, shen jh, lee yj, liao kh, yeh jt. volume shrinkages and mechanical properties of various fiber-reinforced hydroxyethyl methacrylatepolyurethane/ unsaturated polyester composites. compos sci technol 2008; 68: 709-717. type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 20 research article the effects of maternal environmental tobacco smoke exposure on periodontal health and mother-infant bonding in relation to salivary cotinine level nada ziyad salim 1*, ban sahib diab 2 1. master student. department of preventive dentistry, college of dentistry, university of baghdad, baghdad, iraq. 2. professor. department of pedodontic and preventive dentistry, college of dentistry, university of baghdad, baghdad, iraq. bab-almoadham, p.o. box 1417, baghdad, iraq * correspondence email; ziyadnada8@gmail.com abstract: background: environmental tobacco smoking is produced by active smokers burning the tip of a cigarette and breathed by nonsmokers and measured by cotinine level. it has the potential to raise the risk of periodontal disease. one of the most frequent chronic diseases in adults is periodontal disease. the lower maternal-fetal attachment has been found to predict smoking status in previous studies, but no research has examined whether maternal-fetal attachment predicts environmental tobacco smoking. this study assessed the effects of maternal environmental tobacco smoke exposure on periodontal health and mother-infant bonding concerning salivary cotinine levels. materials and methods: this is a comparative cross-sectional study comparing environmental tobacco smoke on exposed and non-exposed mothers aged between 20-35 years with their infants aged up to one year who attended primary health care centers in rural areas of al-karkh sector/baghdad. along with the essential socio-demographic data, a secondhand smoke exposure scale and postpartum bonding questionnaire were employed. collection of unstimulated saliva from mothers was done according to navazesh and kumer in 2008. after that, the clinical assessment of gingival bleeding and periodontal pockets was performed by using community periodontal index according to the world health organization in 1997. results: out of 150 subjects,67(44.66%) were exposed to environmental tobacco whereas the non-exposed mothers were composed of 83 (55.33%). the highest mean number of cpi0(healthy gingiva) and cpi1(gingival bleeding) were among the non-exposed mothers while the highest mean number of cpi2(dental calculus), cpi3 (shallow pocket 4-5mm) and cpi4(deep pocket 6mm or more) were among the exposed mothers. the mean value of cotinine level among the non-exposed mothers was lower than exposed mothers with significant results. a higher salivary cotinine level was linked to a lower maternal-fetal bonding score. conclusions: mother’s exposure to environmental tobacco smoke significantly negatively impacts periodontal disease. furthermore, mothers who have a stronger sense of attachment and affiliation to their fetus have lower salivary cotinine concentrations than mothers who have a less sense of fetal attachment. keywords: cotinine, environmental tobacco smoke, mother-infant bonding, periodontal disease. introduction smoking is inhaling the smoke of burning tobacco encased in cigarettes, pipes and cigars. nicotine, tar, and gases like carbon dioxide and carbon monoxide are the main components of tobacco smoke. toxic tobacco smoke components can be detected not only in the smoke breathed by the smoker but also in environmental tobacco smoke (ets), also referred to as secondhand smoke (shs)—that is, the smoke received date: 08-05-2022 accepted date: 10-06-2022 published date: 15-06-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/lice nses/by/4.0/). https://doi.org/10.26477/jb cd.v35i2.3396 mailto:ziyadnada8@gmail.com https://orcid.org/0009-0000-9402-5767 https://orcid.org/0000-0002-9310-9210 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3396 https://doi.org/10.26477/jbcd.v35i2.3396 j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 21 that a smoker exhales (mainstream smoke) (ms)and the smoke that rises straight from burning tobacco (sidestream smoke) (ss) (1). environmental tobacco smoke (ets) exposure (also known as "passive smoking") is known to have negative health effects, including an increased risk of cardiovascular disease, lung cancer, and respiratory illness (2). one of the most frequent chronic diseases in adults is periodontal disease (3). it is commonly established that tobacco smokers have worse periodontal inflammatory diseases than people who do not use tobacco (4-5). an iraqi study concluded that smoking subjects showed worse periodontal conditions than non-smoking subjects (6). also, another iraqi study done among children suggested that the mean value of plaque index and gingival index were higher among passive smokers than in the control group with a statistically significant difference (7). furthermore, nonsmokers with secondhand smoking solely at home or both at home and elsewhere had a considerably greater frequency of periodontal disease than the nonsmokers without secondhand smoking and secondhand smoker had the same risk of developing periodontal disease as the current smokers; even smokers are at a higher risk for periodontal disease if they are exposed to secondhand smoke (8). sanders et al. (9) revealed that secondhand smoking exposure increased periodontal disease dose-dependently. meanwhile, benowitz et al. (10) state that periodontal disease may be influenced by both active and passive smoking via similar mechanisms. compared to current smokers, nonsmokers exposed to secondhand smoke absorb approximately one-third of the nicotine per cigarette (8). cotinine is a tobacco alkaloid and the primary nicotine metabolite. it has been utilized as a reliable biomarker for tobacco exposure in the literature because of its prolonged half-life (10–30 h) compared to nicotine (30 min) (10). cotinine is measured in nanograms per milliliter (ng/ml). passive smokers had values of less than five ng/ml; heavy passive smokers had values of 10 ng/ml or slightly higher; infrequent regular smokers had levels of 10 to 100 ng/ml; and regular active smokers had levels of 100 ng/ml or higher (11) . in general, nonsmokers exposed to secondhand smoke absorb nicotine and other components at the same rate as smokers, and the more passive cigarette smoke they are exposed to, the higher the amount of these components in their systems becomes (12). because saliva is a simple and non-invasive collection procedure, it is an appealing alternative to traditional biological matrices (such as blood and urine) for measuring cotinine concentrations (13). determination of cotinine levels in unstimulated whole saliva is often performed by using enzyme-linked immunosorbent assay [elisa] (14-16). interaction that is both emotional and reciprocating between a mother and her baby is referred to as bonding. its goal is to keep the baby attached to their carers while keeping the parents close by (17). it has been discovered that maternal-fetal attachment and salivary cotinine one day after birth have a negative relationship, with the lower reported maternal-fetal attachment being linked to greater salivary cotinine at one day after delivery (18). as far as there is no previous studyln iraq concerning the effects of maternal environmental tobacco smoke exposure on periodontal health and mother-infant bonding concerning the salivary cotinine level, this study was conducted. it suggested the null hypothesis that there is no relation between ets and periodontal disease and mother-infant bonding. j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 22 materials and methods the study was conducted using a cross-sectional comparative design among mothers attending the primary health care centers in rural areas of al-karkh sector/baghdad government for child’s scheduled immunization starting from december 2021; till march 2022. they were with the age ranged from 20-35 years with their infants aged up to one year. using g power 3.1.9.7 (program written by franz-faul, universitatit kiel, germany) with the power of study=80%, alpha error of probability=0.05 two-sided. a pilot study was done on ten women for each group and the cpi score was measured for them and the mean cpi score 2 ± sd for environmental tobacco smoke exposure and non-exposed smokers were (1.00±0.12) and (0.9± 0.26) making the cohen's d effect size about 0.5 (medium) between the two groups with all these conditions the sample size was 132 adding 10 % as an error rate (19). thus the sample size was about 145, so 150 subjects was enough and more calculatable than g power. cohen d were: small =0.3, medium=0.5, large>=0.8 (20). this study compares mothers who were exposed to environmental tobacco smoke and mothers who were not exposed to environmental tobacco smoke. before starting the study, approval was achieved from the ministry of health for women's examinations. verbal consent were obtained from all women and the ethical committee had accepted the study's protocol in the college of dentistry, university of baghdad. the research comprised healthy mothers without a medical problems and any medication also pregnant mothers will not be included in the study. a proforma was given to each participant to collect socio-demographic information such as age, educational level, employment, manner of delivery, feeding pattern, and baby's age and gender. the duration of the exposure (years or months), the smoking person (husband or another person), and the type of exposure (cigarettes, cigarettes, and hookah) were all factors in determining the mothers' exposure status. the number of cigarettes smoked per day was then calculated using a secondhand smoke exposure scale (shses) (21) following that, the postpartum bonding questionnaire (pbq) was distributed to all of the sample (mothers) who attended the health center. the pbq is a self-report tool that evaluates a mother's feelings and attitudes toward her infant. it has 25 items scored on a six-point scale (0 to 5) (22). higher scores suggested that the mother has a poor attachment to the infant and she is under more psychological stress as a mother. issa (23) had already obtained the arabic version and translation validity of pbq in the ministry of higher education and scientific research; two translators translated the test items from their original language to the target language (arabic). subgroups of 40 mothers were taken arbitrarily from the two groups to compare the salivary cotinine level. unstimulated salivary samples were collected by drooling into the test tube according to the university of southern california school of dentistry guidelines for saliva collection (24). one hour before the test session, the mothers were told to avoid eating or drinking anything (except water). the mothers were instructed to rinse their mouths with distilled water multiple times before relaxing for five minutes. during the collection, mothers should make as few movements as possible, especially mouth movements, and lean the head forward with their lips slightly open to let saliva flow into the tube. after collecting saliva, each salivary sample was centrifuged (at 2000-3000 rpm) for approximately 20 minutes. after centrifugation, the clear samples were collected by a micropipette and stored in eppendorf tubes at (-20 c) in a deep freeze until biochemical analysis. j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 23 after the collection of saliva, the community periodontal index (cpi) was used to assess the gingival bleeding and periodontal pockets clinically as it is recommended by the who (25) as an indicator of early periodontal disease. clinical examinations were carried out using a plane mouth dental mirror and cpi probe. the concentration of salivary cotinine level was detected by an enzyme-linked immune-sorbent assay (elisa) using a salivary cotinine kit. the reagent preparation concept, technique assay, and result computation were all conducted according to the manufacturer's procedure instructions. statistical analysis the statistical package for social science was used to conduct the statistical analysis (spss version -22, chicago, illionis, usa). the frequency, percentage, mean and standard error were calculated using descriptive analysis with simple and cluster chart bars. the difference between the two groups was tested using inferential analysis as an independent sample t-test parametric test. for the linear correlation between two quantitative variables, the pearson correlation parametric test was used. receiver operating characteristic curve (roc) for optimal cutoff point for differentiation between the two groups. results the sample of this study consisted of 150 mothers with their infants. they were subdivided into two groups according to the ets exposure: mothers who were exposed to ets with their infants, which composed 67 (44.66%) mothers, and non-exposed mothers with their infants, which composed 83 (55.33%) mothers. according to shses, all the exposed mothers were exposed to ets at home 67 (100%). in addition to home exposure, 23 (34.32%) and 22 (32.83%) of them were exposed to vehicles and public places respectively, while the least exposure was at work 8 (11.94%). the results showed that the percentage of mothers in the age range 20-27 was lower than the older age group among passive smokers, while the opposite result was found concerning the non-exposed mothers, as shown in table 1. table 1: the distribution of the sample according to age and environmental tobacco smoke exposure groups age (years) exposed mothers non-exposed mothers 20-27 32 39.51% 49 60.49% 28-35 35 50.72% 34 49.28% table (2) demonstrates that the husband was the primary source of smoking at home, accounting for 55 (82.08 %), with the remaining 12 (17. 92%) coming from persons other than the husband. concerning the exposure duration, 58 (86.57 %) had been exposed for years, whereas 9 (13.43 %) had been exposed for months. j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 24 table 2: smoking exposure characteristics of environmental tobacco smoke-exposed mothers variable category n=67 smoking person husband 55(82.08%) others than husband 12(17.92%) duration of exposure years 58(86.57%) months 9(13.43%) type of the exposed smoking cigarette only 51(76.11%) cigarette and hookah 16(23.89%) the results showed that the non-exposed mothers had healthy periodontium more than those who were exposed. however, the difference was not statistically significant. while the exposed mothers were found to have significantly lower gingival bleeding (score1), and more calculus (score2) in addition to having a more shallow pocket (score3) than the non-exposed mother, however, the same result was found concerning deep pockets (score4), but the difference was not statistically significant as shown in table (3). table 3: descriptive analysis and statistical difference of periodontal health status among the environmental tobacco smoke exposed and non-exposed mothers vars. environmental tobacco smoke exposure exposed mothers non-exposed mothers mean ±se mean ±se ttest pvalue cpi0 0.821 0.147 1.217 0.142 1.918 0.057 cpi1 2.224 0.166 4.096 0.143 8.588 0.000* cpi2 2.239 0.131 0.566 0.094 10.60 0.000* cpi3 0.627 0.104 0.145 0.052 4.400 0.000* cpi4 0.030 0.030 0.000 0.000 1.114 0.267 df=148 *=significant at p≤ 0.05 figure 1 demonstrates that the percentage of mothers with the highest cpi 0 (healthy gingiva) and cpi 1 (gingival bleeding) were among the non-exposed group. regarding cpi 2 (dental calculus), cpi 3 (shallow pocket 4-5mm) and cpi 4 (deep pocket 6mm or more), the highest number was found among the exposed mothers. j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 25 figure 1: distribution of mothers according to the highest score of community periodontal index regarding salivary cotinine level, the findings revealed that the mean values and standard error of cotinine level among the non-exposed mothers were lower than the exposed mothers and the data showed significant results as shown in figure 2. figure 2: descriptive and statistical tests of salivary cotinine levels among the environmental tobacco smoke exposed and non-exposed mothers table (4) shows that salivary cotinine was excellent in differentiation ets exposed from non-exposed mothers with significant results and sensitivity of 95% and specificity of 85% among participants. j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 26 table 4: cotinine cutoff level area under the curve optimal cutoff point %sensitivity %specificity area p-value 4.69350 95 85 0.946 excellent 0.000 * *=significant at p≤ 0.05 the correlation between salivary cotinine level the periodontal health concerning environmental tobacco smoke exposure is displayed in table (5). salivary cotinine level had a negative correlation with cpi0 (healthy gingiva) and cpi1(gingival bleeding) among the exposed and the non-exposed mothers and the results were significant statistically (p≤0.05) concerning cpi1 among the two groups. at the same time, there were positive correlations with other cpi scores with significant correlation regarding cpi2 among the non-exposed mothers. table 5: correlation coefficient of salivary cotinine level with periodontal parameters environmental tobacco smoke exposure total cotinine r p exposed mothers cpi0 -0.084 0.606 cpi1 -0.446 0.004* cpi2 0.524 0.001* cpi3 0.056 0.731 cpi4 0.108 0.508 non-exposed mothers cpi0 -0.298 0.062 cpi1 -0.638 0.000* cpi2 0.564 0.000* cpi3 0.082 0.617 *=significant at p≤ 0.05 the correlation between salivary cotinine and bonding score by groups was displayed in table (6). the results reported that bonding score significantly correlated with cotinine levels among the exposed and the non-exposed mothers (p≤0.05). table 6: correlation of salivary cotinine with bonding score by exposure groups. groups bonding score r p exposed mothers cotinine 0.544 0.000* non-exposed mothers 0.388 0.013* *=significant at p≤ 0.05 j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 27 discussion this study was the first that evaluate the effects of maternal environmental tobacco smoke exposure on periodontal health status and mother-infant bonding based on salivary cotinine levels in iraq. the mothers who participated in the study were housewives from rural areas, and the most prevalent location of exposure was at home, with the husband being the primary source of exposure. these results were consistent with a study by saleh et al. in 2021 in egypt (26). simple explanations for these findings include the presence of various social and cultural norms in rural communities that make them vulnerable to male dominance; additionally, living in a rural area with a lower level of education increases the risk of ets exposure at home, as well as long periods of parental stay at home due to early day hours work and a lack of recreational activities in rural areas compared to urban areas. another research found that nicotine and other tobacco smoke particles contaminated 88% of surfaces in living rooms and newborn bedrooms (27). this study found that cpi 1 (gingival bleeding) was higher among non-exposed mothers with statistically significant differences, which can be explained by the fact that active and secondhand smoking may have similar mechanisms of action on periodontal disease (12). this result agreed with gautam et al. (28), who found statistically significant differences between cigarette smokers and nonsmokers for cpi score of 1 (nonsmokers are more likely to have gingival bleeding). they explained this result by the finding that nicotine, one of several tobacco smoke byproducts, causes local vasoconstriction, which reduces blood flow and edema, as well as inhibiting the early indications of periodontal disease by lowering gingival inflammation, redness, and bleeding. also, this result followed that of tjahajawati et al. (29) study who indicated that nicotine in cigarettes could cause adrenal hormones to be stimulated. it causes the vasoconstriction of peripheral blood vessels, reducing blood flow and oxygen to the gingiva. as a result, passive smokers' inflammatory and bleeding reactions to probing would be reduced. regarding cpi 2 (dental calculus), cpi 3 (shallow pocket 4-5mm) and cpi 4 (deep pocket 6mm or more), the highest number was among the exposed mothers. this result was in agreement with that of ueno et al. (9) who found that ets exposed group showed a significantly higher prevalence of periodontal disease compared to the non-exposed group and concluded that passive smokers showed a similar risk of having the periodontal disease to that of the current smokers. also, the result agreed with the previous iraqi study, which suggests that nicotine changes the immunological response, which may contribute to smokers' higher risk of periodontal disease (6). palmer et al. (30) illustrated the correlation between tobacco and periodontal disease by the effect of tobacco in decreasing the oxygen and other blood constituents to reach the gingiva and reducing the capacity to remove the tissue waste products leading to compromising the immune response and periodontal tissue destruction. another explanation may be attributed to the ability of tobacco smoke and its components to change the bacterial surface and increase biofilm formation in various periodontal pathogens, including porphyromonas gingivalis and aggregatibacter actinomycetemcomitans (31). moreover, inflammatory indicators such as interleukin-1, lactoferrin, albumin, and aspartate aminotransferase have been found to elevate in the saliva of those who had been exposed to cigarette smoke (32). another j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 28 possible explanation is that cotinine increases the potency of toxins generated by periodontopathogenic bacteria such as prevotella intermedia, prevotella nigrescens, treponema denticola, and porphyromonas gingivalis, which may speed up the periodontal disease progression (33). however, these results disagreed with the studies that reported no significant association between ets exposure and periodontal disease (34-35). the current study revealed a higher cotinine level (the reliable biomarker for environmental tobacco smoke exposure) (16) among ets-exposed mothers. the results came in agreement with hassanzad et al. (36) study who concluded that cotinine in saliva was significantly higher among the passive smoker group than the control group. the result also aligned with the other studies which found that the salivary cotinine level in the passive smoker subjects was higher than in the control group (37-38). theoretically, nonsmokers who were exposed to secondhand smoke absorb nicotine and other components in the same way as smokers did, and the more passive cigarette smoke they were exposed to, the higher the level of these components in their bodies (12). also, the results of the current study reported that cotinine level had a positive correlation with the bonding score. this result was in accordance with that of magee et al. (18), who stated that women with fewer sentiments of connection to their fetus had higher salivary cotinine levels during pregnancy and postpartum. the possible explanations for this positive correlation of cotinine with bonding score were that the increase in bonding score indicated the pathology (mother-infant bonding disorder) (39) and there was a well-established connection between nicotine and depression (40). nicotine binds to, activates, and desensitizes nicotinic acetylcholine receptors (nachrs), which might be a key element in nicotine's depressive symptoms effects (41) and since radoš et al. (42) proved that impaired bonding was related to postpartum stress and depression symptoms. hence, the highest cotinine level led to increasing in bonding score. a meta-analysis done by chen et al. (43) indicated that prenatal smoking had been linked to postpartum depression. while women might have postpartum depression, smokers were at a greater risk than nonsmokers (44). another possible explanation linked to maternal exposure to tobacco smoke in pregnancy was a risk factor for preterm birth (birth before 37 weeks gestation) (45) and preterm birth influence negatively on the bonding relationship (46). furthermore, there was a clear link between maternal and paternal smoking and the inability to start breastfeeding a child. a person's smoking habits reflect their attitude toward health. as a result, smoking mothers are likely to be less educated and passionate about breastfeeding than nonsmoking mothers. similarly, fathers who smoke may be a proxy for a poorer degree of health consciousness in the home, which may influence their wives' breastfeeding decisions (47) and since breastfeeding promotes an intimate touch between the mother and infant and so creates a better relationship than bottle-feeding mothers in the early period following childbirth (48). j. bagh. coll. dent. vol. 35, no. 2. 2023 salim and diab 29 conclusion the present study's findings concluded that a mother’s exposure to environmental tobacco smoke harms periodontal disease. it was found that environmental tobacco smoke exposure was associated with lesser gingival bleeding and deeper pockets as compared to the non-exposed mothers. furthermore, the lower maternal-fetal attachment was associated with the greater exposure to environmental tobacco smoke and those who had a stronger sense of attachment to their fetus had lower salivary cotinine concentrations than the mothers who had a less sense of fetal attachment. acknowledgments: we are grateful to everyone who took part in the study. conflict of interest: none. references 1. leone a, landini l , leone a. what is tobacco smoke? sociocultural dimensions of the association with cardiovascular risk. curr pharm des. 2010;16:2510-2517. 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(crossref) ي العنوان: آثار التعرض لدخان التبغ البيئي لألمهات على أمراض اللثة والترابط بين األم والرضيع فيما يتعلق بمستوى الكوتينين اللعاب بان صاحب ذياب ا د الباحثون: ندى زياد سالم , المستخلص: آثار لتقييم الدراسة هذه أجريت. اللثة بأمراض اإلصابة خطر زيادة إلى ويؤدي التدخين، بحالة يتاثر والجنين األم بين التعلق ان السابقة الدراسات اثبت: الخلفية .اللعابي الكوتينين بمستوى يتعلق فيما والرضيع األم بين والترابط الفم صحة على لألمهات البيئي التبغ لدخان التعرض المعرضات غير واألمهات خاص مقياس باستخدام البيئي التبغ لدخان تعرضن اللواتي األمهات بين تقارن مقطعية مقارنة دراسة هذه: العمل وطرق المواد إجراء تم ثم اللعاب جمع تم. الوالدة بعد للترابط استبيان الى باالضافة واحدة سنة إلى أعمارهم تصل الرضع وأطفالهن سنة 35-20 بين أعمارهن تتراوح .العالمية الصحة لمنظمة وفقا المجتمعي اللثة مؤشر باستخدام اللثة وجيوب لنزيف السريري التقييم وكان. عميق جيب و ضحل وجيب االسنان تكلسات لديهم عدد أكبر منهم و البيئي التبغ لدخان تعرضوا العينة من% 44.66 ان النتائج وجدت: النتائج درجات انخفاض ارتبط مهمةحيث نتائج البيانات وتظهر للتدخين المعرضات األمهات من أقل المعرضات غير األمهات بين الكوتينين مستوى قيمة متوسط .اللعابي الكوتينين مستوى بارتفاع والجنين األم بين التعلق العميقة بالجيوب مرتبطا كان البيئي التبغ لدخان التعرض أن وجد وقد. اللثة أمراض على مؤثر ضار تأثير له البيئي التبغ لدخان األم تعرض إن: االستنتاج اللعابي الكوتينين من أقل تركيزات لديهم بجنينهم والتعلق االنتماء من أكثر مشاعر لديهم الذين أولئك فإن ، كذلك و المعرضات غير باألمهات مقارنة https://doi.org/10.4103/jfmpc.jfmpc_369_19 https://doi.org/10.1007/s00737-006-0132-1 https://doi.org/10.1016/j.tips.2010.09.004 https://doi.org/10.1007/s00213-010-1932-6 https://doi.org/10.1016/j.jad.2020.03.006 https://doi.org/10.1080/0167482x.2017.1415881 https://doi.org/10.1080/14622200802412895 https://doi.org/10.1371/journal.pmed.1003386 https://doi.org/10.1111/j.1365-2702.2007.02125.x https://doi.org/10.1111/j.1469-7610.2011.02406.x https://doi.org/10.1016/s0029-7844(02)01940-3 j bagh college dentistry vol. 33(2), june 2021 the effect of composite 1 the effect of composite bonding spot size and location on the performance of poly-ether-ether-ketone (peek) retainer wires ammar salim kadhum(1), akram faisal alhuwaizi(2) https://doi.org/10.26477/jbcd.v33i2.2932 abstract background: poly-ether-ether-ketone(peek) has been introduced to many dental fields. recently it was tested as a retainer wire following orthodontic treatment. this study aimed to investigate the effect of changing the bonding spot size and location on the performance of peek retainer wires. methods: a biomechanical study involving four three-dimensional finite element models was performed. the basic model was with a 0.8 mm cylindrical cross-section peek wire, bonded at the center of the lingual surface of the mandibular incisors with 4 mm in diameter composite spots. two other models were designed with 3 mm and 5 mm composite sizes. the last model was created with the composite bonding spot of the canine away from the center of the crown, closer to the lateral incisor. the linear displacement of the teeth, strains of the periodontal ligament, and stresses in peek wire and composite were evaluated. the data was numerically produced with color coded display by the software. selected values were tabulated and compared among models. results: the amount of linear displacement and strain was very low. stresses in the wire and composite were affected by the size and position of the composite bonding spot. the safe limits were identified at 235 mpa for peek and 100 mpa for composite. the basic model had a von mises stress in the peek wire of 122.09 mpa, and a maximum principal stress in the composite of 99.779 mpa. both stresses were within the safe limits, which means a lower risk of failure in peek and composite. all other models had stresses that exceeded the safe limit of the composite. the 3 mm composite model was the only one that developed stresses in the wire more than the safe limits of peek. conclusions: within the limitations of this study, bonding peek wires with 4 mm bonding spots to the clinical crown center provided the best mechanical performance of the wires and spots; otherwise, the mechanical properties of the wire and composite would be affected and, therefore, might affect the retention process. keywords: retention, peek, finite element analysis (received: 28/2/2021, accepted: 29/3/2021) introduction the teeth have a tendency to return to their initial position following orthodontic treatment; all efforts are attempted to keep them in their corrected position [1]. when the teeth move, the alveolar bone and the periodontal ligament undergo changes. it would take a considerable time for a complete reorganization to finish [2]. life-long or indefinite retention is a routine practice among orthodontists [1, 3]. when instability is anticipated, fixed retention is considered [4, 5]. most patients require a fixed retainer to keep their lower anterior teeth stable after treatment [6]. knierim [7] was the first to introduce fixed retention using a solid 0.028” stainless-steel wire in 1973. since then, many materials were utilized as fixed lingual retainers, including but not limited to: multi-stranded stainless-steel wires, elgiloy blue, glass fiber-reinforced, copper-nickeltitanium, polyethylene ribbon-reinforced, and active nickel-titanium wires [8-10]. each retainer has its downsides, like wire failure, unraveling, bond breakage, allergy, etc. [10, 11]. retainers should have qualities like being esthetic, biocompatible, adaptable with ease to the lingual surface [1], capable of resisting deformation, passive at the time of placement [12], having adequate flexibility to allow physiologic movement of the teeth, which helps to reduce stress concentration within the composite. lastly, it should have good bonding to resin adhesives [8]. the peek is being considered as a substitute for metal alloys in dental practice [13]. it is known for its outstanding mechanical properties. when processed by computer-aided design/computer-aided manufacturing (cad/cam), it shows lower deformations and higher fracture loads than can be achieved by other processing techniques. its field of use is expanding in light of its excellent milling and grinding properties, which highlights its potential in dentistry [14]. in orthodontics, peek was suggested as an alternative archwire to nickel-titanium wires with self-ligating brackets, and it was also tested as a fixed space maintainer [13, 15]. in a laboratory study, peek was compared to a group of metallic retainer wires; it performed as good as the conventional metal wires; hence it was suggested to be tried clinically [16]. (1) assistant professor, department of orthodontics,college of dentistry, university of baghdad, iraq. (2) professor, department of orthodontics, college of dentistry, university of baghdad, iraq corresponding author: ammar.ortho@codental.uobaghdad.edu.iq https://doi.org/10.26477/jbcd.v33i2.2932 mailto:ammar.ortho@codental.uobaghdad.edu.iq j bagh college dentistry vol. 33(2), june 2021 the effect of composite 2 finite element analysis (fea) is a computational method that can assess in a non-destructive and repeatable way the complex biomechanical behavior of heterogeneous materials and structures with complex geometries [17]. in the field of orthodontics, it had been used in many aspects like tooth movement, treatment techniques, temporary anchorage devices, and assessing orthodontic materials [18-22]. this study aimed to investigate the effects of using different composite bonding spot sizes and changing the distance between the bonding spots of the lateral incisor and the canine by assessing threedimensional (3d) finite element models. materials and methods materials the material under investigation is the white blocks dd-peek-med (dentaldirekt, spenge, germany), composed of peek ≥ 80%, and titanium dioxide <20%, according to the manufacturer’s website [23]. methods the three-dimensional design of the model using the fusion 360 software (autodesk, california, usa), the lower anterior teeth were modeled as per the individual description stated in wheeler’s dental anatomy textbook [24]. the teeth model was imported to solidworks 2018 software (dassault systèmes, vélizy, france). the y-axis represented the vertical plane, the x-axis represented the transverse plane, and the z-axis represented the sagittal plane. the roots were covered with pdl represented by a 0.2 mm uniform layer, then spongy bone, and finally, cortical bone. the retainer wire was modeled in a cylindrical form with a 0.8 mm diameter extending along the lingual surface of the lower anterior teeth without contact. the wire was modeled in two halves so that the upper one would be exposed to the forces from the oral direction; these halves were later merged. the resin bonding spots were modeled, covering the peek wire on the center of the clinical crowns (figure 1). figure 1 a cross-section showing the different structures of the model. modified models a. composite diameter: two models were created using two bonding spot sizes, 3 and 5 mm. b. composite location: the location of the bonding spot on the canine was modified so that it was not at the center of the clinical crown; to reduce the distance between the bonding spots. obtaining elastic modulus and yield strength of peek the flexural properties of peek were obtained by following the american society for testing and materials (astm ) standards f2026-17 and d79003. a three-point bending test was performed on eight test specimens, using a universal compression and tension machine (tinius-olsen, pa., usa) with a 1 kilo-newton load cell. the test specimen dimensions were 1.6 mm in thickness, 30 mm in length, and 12.7 mm in width. the support span was 25 mm, and the cross-head diameter 5 mm. the calculated cross-head speed was 0.65 mm/min. finite element analysis material properties the models were imported into ansys workbench 18.2 (ansys, canonsburg, pa). the static structure simulation was selected for the 3d model. all materials were assumed linearly elastic, homogenous, and isometric for simplification purposes. table 1 shows the properties of the materials that were determined from previous work [25-27] and the three-point bending test on peek. j bagh college dentistry vol. 33(2), june 2021 the effect of composite 3 table 1 material properties structure young’s modulus (mpa) poisson’s ratio tooth 20300 0.26 pdl 0.667 0.49 spongy bone 13400 0.38 cortical bone 34000 0.26 composite 16600 0.24 peek 5130 0.39 boundary condition and loading the bone segment was fixed at the posterior surface of both ends in all directions. the contacts between teeth and pdl, pdl and spongy bone, spongy bone to compact bone, and composite to teeth and pdl were set to “bonded.” according to the work of serra and manns [28], a 295.3 n (that equals the maximum biting force on the anterior teeth) was applied to the upper half of the wire at a 45° angle to the horizontal plane (figure 2) [25]. this angle corresponds to the direction of force being applied in a vertical direction while the mouth is widely opened for biting. two force components were used to achieve this, a vertical component of -201.75 n and a horizontal component of 201.75 n. convergence tests the convergence tests were performed to identify the smallest mesh size that will yield acceptable results without jeopardizing the results. the mesh size was gradually reduced from 0.4 mm to 0.1 mm, while all other variables were unchanged. the results were evaluated at three vertices on the peek, pdl, and tooth. multiple parameters were considered, including total deformation, equivalent von mises stress in the pdl, and finally, the equivalent von mises stresses for peek. a 5% variation was considered acceptable, as it was assumed to have no clinical significance. due to the nature of the finite element analysis, which produces a single value for each parameter per model, statistical analysis was not possible. the data was numerically produced with color coded display by the software. selected values were tabulated and compared among models. figure 2 boundary conditions and loading, a, lingual view showing the fixed lingual surfaces of bone (colored blue), b, a close-up occlusal view. results the yield strength and modulus of elasticity the three-point bending test results of peek were averaged to a yield strength of 235 mpa, and modulus of elasticity of 5130 mpa. this data was used to feed the fea. the convergence tests the 0.2 mm mesh size provided acceptable accuracy, with changes less than 5%. a finer mesh would have no added value, but it would significantly increase computation time and model size (table 2). therefore, the 0.2 mm mesh size was used for all models. the examined parameters were as follows (figure.3): total deformation of the whole model (tdm), total deformation of peek wire (tdp), elastic strain of the whole model (es), maximum principal stress in the composite bonding spots (mxps-c), maximum principal stress in the peek wire (mxps-p), minimum principal stress in the peek wire (mnps-p), maximum von mises stress in the peek wire (mxvm-p), and safety factor (sf). for all models, both the tdm and tdp were minimal; they were around 0.2 mm. the findings of the four models are shown in table 3 and figure 4. j bagh college dentistry vol. 33(2), june 2021 the effect of composite 4 table 2 the results of convergence test m e sh s iz e ( m m ) t o ta l d e fo rm a ti o n o f to o th v e rt e x (m m ) c h a n g e ( % ) v o n m is e s st re ss p d l v e rt e x ( m p a ) c h a n g e ( % ) v o n m is e s st re ss o f p e e k v e rt e x ( m p a ) c h a n g e ( % ) n o d e s e le m e n t 0.4 0.188 n/a 0.997 n/a 24.285 n/a 413,601 227,927 0.3 0.189 0.5 0.076 -92.4 8.465 -65.1 693,815 386,680 0.2 0.190 0.5 0.082 7.9 12.646 49.4 1,760,868 1,000,075 0.1 0.187 -1.6 0.084 2.4 12.782 1.1 8,014,078 4,617,393 figure 3 the parameters investigated in this study. (a) total deformation of the whole model(occlusal view), (b) total deformation of the whole model (cross-sectional view), (c) total deformation of the peek wire, (d) maximum elastic strain of the pdl (frontal view), (e) maximum elastic strain of the pdl (lingual view showing pdl only), (f) maximum principal stress in composite, (g) maximum principal stress in peek wire, (h) minimum principal stress in the peek wire, (i) equivalent von mises stress in the peek wire. j bagh college dentistry vol. 33(2), june 2021 the effect of composite 5 table 3 stresses, strain, and deformations associated with different models the greatest tdm was at the tip of the central incisor, while the greatest tdp was at the upper margin of the wire. the difference in es was also minimal. it occurred at the upper distolabial margin of the lower central incisor pdl. as shown in figure 5, the basic model and the 5 mm composite models shared a common stress concentration area at the distal margin of the composite of the lateral incisor. the failure region for the 3 mm composite model was at the mesial margin of the bonding spot of the lateral incisor. finally, the model with the modified composite position had a failure point more anteriorly, at the lateral side of the lower central incisor. all models had their failure regions associated with compressive stress. parameters 3mm 4mm 5mm modified position 1. total deformation of the whole model(mm) 0.198 0.194 0.19 0.202 2. total deformation of the peek wire (mm) 0.175 0.167 0.162 0.175 3. elastic strain 1.849 1.817 1.78 1.893 4. maximum principal stress in the composite bonding spots (mpa) 267.82 99.779 134.03 153.12 5. maximum principal stress in the peek wire (mpa) 220.7 79.219 48.161 39.762 6. minimum principal stress in the peek wire (mpa) -288.0 -204.70 -89.786 -144.4 7. maximum von mises stress in the peek wire (mpa) 241.3 122.09 54.73 94.201 8. safety factor 0.974 1.925 4.294 2.495 figure 4 the effect of the size and position of composite bonding spots on maximum principal stress in composite and peek, and maximum von mises stress in peek (up), and minimum principal stress in peek (down). the blue and grey lines represent the safety limits for composite spots and peek wires respectively. j bagh college dentistry vol. 33(2), june 2021 the effect of composite 6 all models, except the 3 mm composite model, had a safety factor greater than one. the 3 mm composite model showed significant deterioration in the performance of the peek wire. it had greater stresses than all other models. the most remarkable change was in the mxps-p. on the other hand, the 5 mm composite model showed lower stress values for the peek than the basic model. the mnps-p and mxvm-p were well below half that of the basic model. nonetheless, the mxps-c was increased by greater than 30%. the sf was the greatest among all models; it was more than double that of the basic model at 4.294. the modified composite position model showed an improved performance of the peek wire, with reduced stresses compared to the basic model. the greatest reduction was in the mxps-p, which was almost half that of the basic model. while the sf for the peek was increased by around 30%.the mxpsc was increased by more than 50%. discussion multi-stranded wires had been the most common type of fixed retainers for decades [11]. the peek is a member of the family poly-aryl-ether-ketone, which is known for good strength, high mechanical fatigue strength, and having a very good chemical resistance [29]. it has several advantagesover stainless-steel wires; these include providing better fitness as it is fabricated by cad\cam, chemical resistance to all oral fluids, can be used in patients with nickel hypersensitivity, improved esthetics, and finally, lacking latent activation forces, which means reduced post retention tooth movement. recently, peek was tested as a retainer wire using wire segments bonded to the lingual surface of bovine incisors [16]; the results were promising for using peek as a retainer wire. this laboratory study had two basic aspects: first, using molds to standardize the quantity of the applied composite resin adhesives; second, a two-millimeter distance. furthermore, the two-millimeter distance may represent the distance between the bonding spots of the central and lateral incisors, but the distance between the lower canine and lateral is different. therefore, it was assumed that some clinicians might apply a smaller or larger amount of composite (supposedly 3 and 5mm in diameter, respectively). bonding to the center of the clinical crown is the figure 5: the safety factor of peek in four models, the blue indicator shows the lowest safety factor value i.e, failure site. (a) basic model, (b) modified composite position, (c) 3 mm composite bonding spot, (d) 5 mm composite bonding spot. j bagh college dentistry vol. 33(2), june 2021 the effect of composite 7 position used by clinicians and is the one used in the basic model. a more mesial modified position was created to approximate the two millimeters distance between the bonding spots, which was used in the laboratory study. modeling the wire in two halves was performed to better simulate the oral conditions, where the superior-posterior surface is the one exposed to forces resulting from oral functions. this methodology was not adopted before in the limited number of similar articles [27, 30, 31]. the force was applied to the wire surface only to simulate the direct transmission of biting forces to the fixed retainer wire, representing a commonly seen mode of failure of mandibular retainers [32]. stresses can be described as principal stresses, shear stresses, and von mises stresses. the first type denotes those taking place along the principal axes: z, y, and x. these can have a positive value indicating tensile stress or a negative value indicating compressive stress. the second type describes stresses occurring around each two planes z/x, x/y, and z/y. the last type represents a theoretical value resulting from a formula that combines the principal and shear stresses into single non-directional equivalent stress. therefore, its value is always positive and is often referred to as equivalent stress[33]. a material fails when the von mises stress equals or exceeds the yield strength. this is best used for ductile materials. on the contrary, principal stresses are used for the prediction of brittle materials failure [17, 33]. the safety factor is used to describe the relationship between the von mises stress and the yield strength. therefore, if the sf was smaller than one, this indicates a possible mechanical failure for the material at this point; conversely, if it was larger than one, this indicates a safe condition with that level of stress [34]. the effects of altering the size and position of the bonding spots on the amount of displacement (total deformation of the model and the peek wire) and the pdl straining were of minimal value, which seemed to be limited to the pdl thickness, as the rigid bone structure prevented further displacement. no model had a failure at the central region between the central incisors. this may be attributed to that both central incisors move to the same degree, which keeps stresses at the mesial side of the bonding spots lower than stresses at other regions. the failure region (i.e., with the lowest sf) for the basic and the 5 mm composite bonding spot models was distal to the lateral incisors. this could be related to that this region is the longest span within the mandibular anterior teeth. additionally, the other spans are very short with the latter model, making the wire more rigid. the more mesial position of the bonding spot relative to the center of the canine reduced the span between the lateral and the canine, making the wire more rigid. the failure point shifted more anteriorly to be distal to the central incisors. in the last model, reducing the spot size to 3 mm increased the span length, which increased the flexibility of the wire. the failure point was mesial to the lateral incisor. except for the 3 mm model, the peek retainer wires would withstand the maximum biting force, but the composite may not. the orthodontic adhesive used by kadhum and alhuwaizi [16] was transbond xt light cure orthodontic adhesive (3m unitek, monrovia, ca, usa). this bonding material has 77 wt% silica filler particles; its flexural strength was reported by ryou et al. [35] as 113 (14.3) mpa, while gama et al. [36] reported it to be 152.7 (31.4) mpa. these findings propose that we should be looking for maximum principal stress close to 100 mpa to avoid failure of the composite. this value can only be found in the basic model. all other models had an mxps-c that was greater than 100 mpa (figure. 4). since there are no studies with a similar scope and outcomes, comparisons were limited. clinical impact the results of this study highlight the effects of changing the size and position of composite on the retainer wire. it would be a better practice to standardize the amount of composite by using molds and ensuring that the bonding site is to the center of the lingual surface of the teeth. otherwise, the mechanical behavior of retainer wires might be altered, which will affect composite and eventually might impact the whole retention process. limitations the fea is only an approximation of the actual situation. caution must be practiced when interpreting the findings of this study in terms of clinical practice due to the following facts: 1. the teeth were modeled with an idealized shape and position. j bagh college dentistry vol. 33(2), june 2021 the effect of composite 8 2. the pdl was assumed to have equal thickness all around the roots and have linear behavior, which is not the real condition. 3. the shape of the bone was an approximation of the basic cross-sectional shape of the mandible. 4. the wire was modeled with ideal geometry and dimension; in real life, there may be inaccuracies in milling the retainer wire, or the retainer wire may have some notches or scratches that will affect its mechanical performance. conclusions within the limitations of this study, bonding peek wires with 4 mm bonding spots to the clinical crown center provided the best mechanical performance of the wires and spots; otherwise, the mechanical properties of the wire and composite would be affected and, therefore, the retention process. acknowledgments the authors thank the team in the mechanical engineering department of the university of technology for their advice and support in the 3d design and finite element analysis. conflicts of interest the authors has nothing to disclose. references 1. littlewood, s.j., d.t. millett, b. doubleday, d.r. bearn, h.v. worthington. retention procedures for stabilising tooth position after treatment with orthodontic braces, in the cochrane database of systematic reviews. 2016. 2. reitan, k. clinical and histologic observations on tooth movement during and after orthodontic treatment. am j orthod. 1967;53: 721-745. 3. valiathan, m., e. hughes. results of a survey-based study to identify common retention practices in the united states. am j orthod dentofacial orthop. 2010;137: 170-177. 4. rody, w.j., t.t. wheeler. retention management decisions: a review of current evidence and emerging trends. semin orthod. 2017;23: 221-228. 5. proffit, w.r., h.w. fields, b.e. larson, d.m. sarver. contemporary orthodontics. 6th ed. 2019, philadelphia: elsevier 6. renkema, a.m., s. al-assad, e. bronkhorst, s. weindel, c. katsaros, j.a. lisson. effectiveness of lingual retainers bonded to the canines in preventing mandibular incisor relapse. am j orthod dentofacial orthop. 2008;134: 179.e1-8. https://doi.org/10.1016/j.ajodo.2008.06.003. 7. knierim, r.w. invisible lower cuspid to cuspid retainer. the angle orthodontist. 1973;43: 218-219. 8. zachrisson, b.u. multistranded wire bonded retainers: from start to success. am j orthod dentofacial orthop. 2015;148: 724-727. 9. kloukos, d., i. sifakakis, t. eliades, w. brantley. 15 bonding of fixed lingual retainers in orthodontics, in orthodontic applications of biomaterials, t. eliades and w.a. brantley, editors. 2017, woodhead publishing. p. 241-252. 10. kravitz, n.d., d. grauer, p. schumacher, y.-m. jo. memotain: a cad/cam nickel-titanium lingual retainer. am j orthod dentofacial orthop. 2017;151: 812-815. 11. sfondrini, m.f., p.k. vallittu, l.v.j. lassila, a. viola, p. gandini, a. scribante. glass fiber reinforced composite orthodontic retainer: in vitro effect of tooth brushing on the surface wear and mechanical properties. materials. 2020;13: https://doi.org/10.3390/ma13051028. 12. annousaki, o., s. zinelis, g. eliades, t. eliades. comparative analysis of the mechanical properties of fiber and stainless steel multistranded wires used for lingual fixed retention. dent mater j. 2017;33: e205e211 https://doi.org/10.1016/j.dental.2017.01.006. 13. tada, y., t. hayakawa, y. nakamura. load-deflection and friction properties of peek wires as alternative orthodontic wires. materials. 2017;10: 914 https://doi.org/10.3390/ma10080914. 14. stawarczyk, b., m. eichberger, j. uhrenbacher, t. wimmer, d. edelhoff, p.r. schmidlin. three-unit reinforced polyetheretherketone composite fdps: influence of fabrication method on load-bearing capacity and failure types. dent mater j. 2015;34: 7-12. 15. ierardo, g., v. luzzi, m. lesti, et al. peek polymer in orthodontics: a pilot study on children. j clin exp dent. 2017;9: e1271-e1275 https://doi.org/10.4317/jced.54010. 16. kadhum, a.s., a.f. alhuwaizi. the efficacy of polyether-ether-ketone wire as a retainer following orthodontic treatment. clin exp dent res. 2020: https://doi.org/10.1002/cre2.377. 17. thompson, m.c., c.j. field, m.v. swain. the allceramic, inlay supported fixed partial denture. part 2. fixed partial denture design: a finite element analysis. aust dent j. 2011;56: 302-311. 18. wang, d., y. yan, c. wang, y. qian. 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dentistry vol. 33(2), june 2021 the effect of composite 9 orthodontic forces. am j orthod dentofacial orthop. 2019;155: 543-551. 22. gupta, m., k. madhok, r. kulshrestha, s. chain, h. kaur, a. yadav. determination of stress distribution on periodontal ligament and alveolar bone by various tooth movements a 3d fem study. journal of oral biology and craniofacial research. 2020;10: 758-763. 23. dentaldirekt. dd peek med blanks of polyether ether ketone. 2018 [cited 2019 15/05/2019]; available from: https://www.dentaldirekt.de/en/products/materials/pol ymers/dd-peek-med. 24. nelson, s.j. wheeler's dental anatomy, physiology and occlusion. 10th ed. 2015, china: elsevier 25. geramy, a., s. faghihi. secondary trauma from occlusion: three-dimensional analysis using the finite element method. quintessence int. 2004;35: 835-843. 26. 26. geramy, a., s.m. morgano. finite element analysis of three designs of an implant-supported molar crown. j prosthet dent. 2004;92: 434-440. 27. gerami, a., s. dadgar, v. rakhshan, p. jannati, f. sobouti. displacement and force distribution of splinted and tilted mandibular anterior teeth under occlusal loads: an in silico 3d finite element analysis. prog orthod. 2016;17: 16. 28. serra, c.m., a.e. manns. bite force measurements with hard and soft bite surfaces. j oral rehabil. 2013;40: 563-568. 29. mckeen, l.w. 12high temperature/high performance polymers, in permeability properties of plastics and elastomers l.w. mckeen, editor. 2019, william andrew publishing: pa, usa. p. 289-303. 30. geramy, a., j.m. retrouvey, f. sobuti, h. salehi. anterior teeth splinting after orthodontic treatment: 3d analysis using finite element method. j dent. 2012;9: 90-98. 31. jahanbin, a., m. abtahi, f. heravi, m. hoseini, h. shafaee. analysis of different positions of fiberreinforced composite retainers versus multistrand wire retainers using the finite element method. international journal of biomaterials. 2014;2014: 581029. 32. stout, m.m., b.k. cook, d.d. arola, h. fong, a.j. raigrodski, a.-m. bollen. assessing the feasibility of yttria-stabilized zirconia in novel designs as mandibular anterior fixed lingual retention after orthodontic treatment. am j orthod dentofacial orthop. 2017;151: 63-73. 33. lang, l.a., r.f. wang, b. kang, s.n. white. validation of finite element analysis in dental ceramics research. j prosthet dent. 2001;86: 650-654. 34. pérez-gonzález, a., j.l. iserte-vilar, c. gonzálezlluch. interpreting finite element results for brittle materials in endodontic restorations. biomed eng online. 2011;10: 44 https://doi.org/10.1186/1475925x-10-44. 35. ryou, d.-b., h.-s. park, k.-h. kim, t.-y. kwon. use of flowable composites for orthodontic bracket bonding. the angle orthodontist. 2008;78: 1105-1109. 36. gama, a.c.s., a.g.d.v. moraes, l.c. yamasaki, a.d. loguercio, c.n. carvalho, j. bauer. properties of composite materials used for bracket bonding. braz dent j. 2013;24: 279-283. الخالصة كيتون )البيك( في العديد من مجاالت طب األسنان. وقد تم مؤخرا اختبارها مثبتاً لألسنان بعد اكمال عالج -ايثر-ايثر-تم استعمال مادة البولي: الخلفية تهدف هذه الدراسة إلى تقييم تأثير تغيير حجم وموقع الروابط الراتنجية على أداء أسالك التثبيت من البيك. .تقويم األسنان التصميم األساس تضمن سلكا من .حيوية تضمنت أربع تصاميم ثالثية األبعاد للعناصر المحددة-تم إجراء دراسة ميكانيكية: العمل وطرق المواد ملم. تم تصميم 4ملم، مثبت إلى وسط السطح اللساني لتاج األسنان األمامية السفلى باستعمال روابط راتنجية بقطر 0.8دائري بقطر البيك ذو مقطع ملم. في حين تم تصميم النموذج األخير بتغيير موقع الرابط الراتنجي على الناب بعيدا عن وسط السن باتجاه 5و 3نموذجين بحجم روابط راتنجية جية.من اطع الجانبي. تم تقييم االنحرافات الخطية في االسنان، والشد في النسيج الرابط حول السني، واالجهادات في سلك البيك والروابط الراتن للق خالل برنامج التحليل، تم توليد البيانات وعرضها بترميز لوني. تم جدولة قيم بيانات مختارة ومقارنتها بين التصاميم المختلفة. تم تحديد حدود كان مقدار االنحرافات الخطية صغيرا جدا. تأثرت االجهادات في السلك والروابط الراتنجية بتغيير حجم وموقع هذه الروابط.:ئجالنتا ميكا باسكال لمادة الالصق الراتنجي. في التصميم االساس، كانت قيم إجهاد فون ميسز في سلك البيك 100ميكا باسكال لمادة البيك و 235األمان بـ لـ الراتنجية 122.09مساوية اللواصق في الرئيسي االقصى واالجهاد باسكال، كالهما 99.779ميكا ويقع باسكال، األمان ميكا حدود ضمن حدود للمادتين، مما يعني انخفاض مستوى خطورة فشل السلك والرابط الراتنجي في هذا التصميم. تجاوزت مستويات االجهاد في التصاميم المتبقية ألسالك البيك.* مليمات كان الوحيد الذي تجاوزت فيه قيم االجهادات حدود األمان 3األمان للروابط الراتنجية. التصميم ذو حجم روابط ملم 4تثبيت أسالك البيك إلى وسط السن باستعمال روابط راتنجية بقطر مع االخذ بنظر االعتبار العوامل المحددة لهذه الدراسة فإن : االستنتاجات مما يعني التأثير على عملية يوفر االداء الميكانيكي األفضل لألسالك وللروابط، بخالفه فإن الخصائص الميكانيكية لألسالك والروابط سوف تتأثر التثبيت برمتها. .الكلمات المفتاحية: التثبيت، البيك، تحليل العناصر المحددة articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. https://www.dentaldirekt.de/en/products/materials/polymers/dd-peek-med https://www.dentaldirekt.de/en/products/materials/polymers/dd-peek-med https://doi.org/10.1186/1475-925x-10-44 https://doi.org/10.1186/1475-925x-10-44 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ esraa f.docx j bagh college dentistry vol. 28(2), june 2016 comparative assessment pedodontics, orthodontics and preventive dentistry 126 comparative assessment of in vitro effect of three fluoride releasing agents on enamel demineralization around orthodontic brackets esraa s. jasim, b.d.s., m.sc. (1) noor m.h. garma, b.d.s., m.sc. (1) samer aun thyab, b.d.s., m.sc. (2) abstract background: white spot lesion considered as irreversible tooth demineralization presenting challenge to orthodontists during treatment schedules, fluoride was the most successfully used measure to overcome this challenge. materials and method: a total of forty sound human permanent premolars were used in the present study and categorized into four groups, in one group the teeth were bonded with stainless steel brackets using resin-modified glass ionomer cement (rmgic) and the other three groups the teeth were bonded with light cured composite resilience® (ortho technology co., usa). group a; acidulated phosphate fluoride (apf) topical gel (mfg by deepak products, inc, usa), fluoride ion 1.23% applied on examine area for four minute. group b; rmgic (gc fuji ortho lc, gc corporation/japan) used as bracket adhesive. group c; stannous and sodium phosphate fluoride gel yielding 0.72% fluoride ion (mfg. for: dental resources ds-8) (0.4% stannous fluoride, 1% sodium fluoride), was applied daily through the experimental study. d; the control group represents the conventional bonding procedure with no preventive method. the entire labial surfaces except 2 mm gingival to the bracket were isolated by acid resistance varnish. all the teeth were subjected individually during 30 days in to acid challenge cycle. after longitudinal sectioning of the teeth by using a hard-tissue microtome, the depth of the artificial lesion was estimated by taking the average of three penetration depths at the lesion centre under stereomicroscope. also the enamel surface was classified according to acid etch pattern. comparisons of the average caries penetration of the groups were submitted to anova and lsd tests. the statistical significance level was set at p ≤ 0.05. results: the results revealed that there were statistically significant differences among the tested groups. with different caries reduction abilities, apf group showed 14%, rmgic group 49%, group stannous and sodium phosphate fluoride 39% depth reduction compared to the control group. conclusions: while all the groups showed caries reduction by different fluoride agents used in this study, the less average lesion depth was found at group b making the rmgig the best caries fighting fluoride measure. key words: demineralization, rmgic, apf, stannous fluoride. (j bagh coll dentistry 2016; 28(2):126-133). introduction despite the revolutionary events in dental and orthodontic materials, instruments and techniques yet, the white spot lesion (wsl) still presents a major drastic effect associated with orthodontic treatment. previous studies showed that orthodontic attachments increase the plaque accumulation and adherence in oral cavity. (1) streptococcus mutans and lactobacillus aggregate in high concentrations in the mouth in the presence of orthodontic fixed appliances. (2) these and other cariogenic bacteria ferment carbohydrates to produce organic acids. these acids can lead with time to the dissolution of calcium and phosphate ions from the enamel surfaces. this process of demineralization may lead to wsl and even cavitation as little as 4 weeks. (3) this irreversible state of the tooth surfaces loss jeopardizing the successful outcome of orthodontic treatment. (1) lecturer. department of orthodontics. college of dentistry, university of baghdad. (2) lecturer. department of conservative dentistry college of dentistry, university of baghdad. fluoride is stated to be the most important agent to prevent demineralization and inhibit lesion progression. (4) fluoride ion prevents plaque activity and adhesion by blocking enzyme system. also fluoride ions in dental plaque replace the hydroxide ion in the crystalline lattice of enamel surface to form a more acid resistant structure called fluorapatite. the remineralization of a preexisting wsl requires ten calcium ions and six phosphate ions with every two fluoride ions to form one fluorapatite unit. (5) fluoride can be used topically (fluoridated tooth paste, gel, mouth rinse, and varnish) or incorporated into cements, elastomeric ligature, or chains. (6) although the preventive measures like toothpastes and mouth rinses are effective, they had not been entirely successful since they need patient cooperation. (7) therefore, during the last years studies are being made to develop methods that do not require patient compliance (8), fluoridated varnishes, gels, bracket bonding materials can be utilized. many studies have stated that fluoride gels during orthodontic treatment can provide additional preventive actions when brackets have been bonded with composite resin cement. (6) j bagh college dentistry vol. 28(2), june 2016 comparative assessment pedodontics, orthodontics and preventive dentistry 127 uysal et al (9) tried sodium fluoride containing topical gel that were applied for five minutes only once on the enamel surfaces and was significantly able to raise the enamel microhardness and prevention of dissolution. professionally applied 1.23% apf gel was introduced in the 1960s; it contains fluoride (12,300 ppm fluoride) in the form of sodium fluoride at ph 3. (10) this preventive agent was developed in response to elaborated investigations to accelerate enamel fluorapatite formation, inhibit decalcification, and increase fluoride incorporation to the enamel surface. fluoride uptake by enamel surface can be increased by ph decreasing less than 4, this can achieved by acidulating fluoride solution, however, acidic solutions prepared from hydrochloric or acetic acid produced enamel demineralization. therefore, they were replaced by phosphoric acid because it did not cause demineralization. (11) stannous fluoride gels 0.4% could be described as home non-prescription drugs, it will react with enamel to form tin fluoro phosphate complex that coat enamel surface and dentinal tubules, they provide some bacteriostatic activity, making them preferable in patients needing caries control, plaque reduction and sensitivity reduction. (12,13) boyd (14) recommended snf gel as a more effective preventive agent than naf rinse or fluoridated tooth paste alone because of its dual action on decalcification and gingivitis prevention, he found 29% decalcification reduction in adolescent orthodontic patient using 0.4% snf gel compared to 0.05% naf rinse. stannous fluoride can be used alone or in combination with other flouride containing solution as antierosive agent. (15,16) tin would precipitate in the outermost enamel layers and become more acid resistant surface , a complex of demineralization and reprecipitation process modifies the uppermost layers of enamel and increasing its defense ability against acid. the scanning electron microscope (sem) images support the theory that snf2, like tif4, may work through the formation of a protective surface layer, limiting or delaying the direct contact of the acid with the enamel mineral. (16) fluoride-releasing orthodontic adhesives were developed to exhibit an additional source of fluoride near the brackets and permit a regular release of topical fluoride. in the late 1980s, gic were proposed as a substitute to the more popular used composite material for bracket bonding (17), they can offer regular exposure of fluoride over several months, and the possible development of a modified, less cariogenic microflora. (18) fluoridereleasing gic and rmgic have been shown to exert some cariostatic effects in both prospective and longitudinal clinical trials. (19 20) also; gic has the ability to absorb fluoride from topical fluoride applications. this feature allows it to act as a long-term fluoride releasing agent. (21) because of recent improvements in the fluoridereleasing capabilities and the shear bond strength (sbs) of rmgic, it has been suggested that these bonding material should play a greater role in attachment bonding in the future. (22) the preventive effect of adhesives adjacent to brackets has been investigated in vitro (7, 23) and in vivo (19, 24) by quantifying the demineralization depths and the mineral losses with various evaluation methods. this study was conducted to compare the acid resistance potential of three fluoride releasing measures being used against demineralization around orthodontic brackets, rmgic as bracket bonding material, acidulated phosphate fluoride gel and stannous and sodium phosphate fluoride gel. material and methods teeth collection: a total of forty sound human premolars were collected and stored in water containing 0.2% thymol. the collected teeth examined with magnifying lens, the buccal enamel surface of the teeth had no developmental defects, cracks, caries, or white spots. the teeth had not been exposured to any pretreatment with chemical agents such as hydrogen peroxide; the remaining visible soft tissue was debrided with razor blade. the teeth were cleaned and cleaned with a pumising paste for 10 seconds. each tooth was then rinsed with tap water for 30 seconds and dried with oil free air for 10 seconds. teeth grouping: the teeth were divided randomly into four groups containing 10 teeth each according to the caries prevention method: group a; acidulated phosphate fluoride (apf) topical gel (deepak products, inc, usa), concentration of fluoride ion 1.23%. group b; resin-modified glass ionomer cement rmgic (gc fuji ortho lc, gc corporation/japan) used as bracket adhesive. group c; stannous and sodium phosphate fluoride gel yielding 0.72% fluoride ion (dental resources ds-8)(0.4% stannous fluoride,1% sodium fluoride. group d; the control group represents the conventional bonding procedure with no preventive measure. j bagh college dentistry vol. 28(2), june 2016 comparative assessment pedodontics, orthodontics and preventive dentistry 128 bonding procedure: all the teeth were bonded with edgewise premolar metal stainless-steel (bionic) brackets (ortho technology co., usa). the bonding procedure was done using light cured composite resilience®(ortho technology co., usa) for all groups except group ii was bonded using resinmodified glass ionomer cement rmgic (gc fuji ortho lc, gc corporation/japan). after polishing and dryness of the buccal surface of the teeth, adhesive tape was placed on buccal surface of tooth at a level of base of bracket to leave only the exposed enamel received the acid etching and adhesive material and prevent any excess of the bonding agent and composite from invading the reading area. conventional etching was performed with 37% phosphoric acid for 30 seconds followed by rinsing for 30 seconds and drying for 10 seconds and bonding layer were applied and air dried. immediately after applying the adhesive (composite or rmgic) to the bracket base, excess was removed with a probe. flash max 2 light cure unit (csm dental aps, denmark) was used to cure the two types of adhesives. this super led has an optical out-put well above 4.000 mw/cm2. six seconds; three seconds from mesial and three seconds from distal sides illuminated the adhesives with a minimum separation distance of 1-2 mm. demineralization procedure: each crown surface of all groups was painted with acid-resistant varnish, leaving an exposed 2 mm space along the gingival side of the bracket base which already was covered with adhesive tape so that only the exposed enamel would be attacked by acid, after the removal of the tape the varnish was left to set overnight , to induce caries like lesion on enamel surface of all the examined teeth a daily procedure of ph cycling was followed including a demineralization period of 7 hours and a remineralization period of 17 hours. each crown was immersed individually in 10 ml of demineralization solution consisted of (0.075m/l acetic acid,1.0 m m/l calcium chloride, 2.0 m/l m potassium phosphate) at ph 4.3 for 7 hours at 37°c. specimens were then removed from the demineralization solution, rinsed with deionized water, and immersed individually in 10 ml of the remineralization solution at 37°c overnight (17 hours) to simulate the remineralizing stage of the caries process.(7) the remineralizing solution consist of (150 m m/l potassium chloride, 1.5 m m/l calcium nitrate 0.9m m/l potassium phosphate) buffer at ph 7.0. each solution was changed and cycling system was repeated daily during the 30-day process. teeth in group a and c were fluoridated according to the manufacturing instruction, for group a acidulated phosphate fluoride gel was applied with disposable brush for 4 minutes only once before the demineralizing-remineralizing cycling regimen while for group c teeth were dried after rinsing with air for 10 second then stannous and sodium phosphate fluoride gel was applied with a disposable brush for one minute in between the demineralization and remineralization procedures every day, both fluoridated gel were removed after the application time with a piece of cotton and absorbent towel then wait for 30 minutes before return to demineralization-remineralization sequence. demineralization resistance test after completing the demineralization procedure, each tooth was washed with distal water for 10 minutes and then the root embedded in acrylic resin block with exposed crown at a level of cement-enamel junction. the brackets were removed with bracket removal plier, then each tooth was immersed in 0.5 % methylene blue solution (25) for a whole day separately in plastic container, then the teeth were washed under running water for a 10 min, air dried and prepared for ground sectioning. to test the acid resistance of the treated specimens, ground sections of approximately 100 µm of thickness were made in a coronal-apical direction perpendicular to the cusp edge so that each tooth was sectioned longitudinally by using low speed saw with of a hard-tissue microtome with water coolant. the sections carefully washed and isolated in labeled petri dishes then placed on glass slab. all ground longitudinal sections were examined under stereomicroscope with maximum illumination. the enamel surface was classified by an experienced investigator, according to ibrahim et al into: (26) type i preferential dissolution of the prism cores resulting in a honey-comb-like appearance; type ii preferential dissolution of the prism peripheries creating a cobblestone-like appearance; type iii a mixture of type i and type ii patterns; type iv pitted enamel surfaces as well as structures that look like unfinished puzzles, maps or networks; type v flat, smooth surfaces. measurement of lesion depth in testing groups was performed by calculating the average of three depths (d1, d2, d3) values of 100 µm apart located at the centre of artificial caries lesion with the aid of graduated ruler, as shown in fig1. j bagh college dentistry vol. 28(2), june 2016 comparative assessment pedodontics, orthodontics and preventive dentistry 129 anova test was performed to identify the presence of statistically significant differences for all group of this study. lsd test was performed to identify the differences between each paired group. results caries penetration depth: the results showed that the lowest caries penetration depth mean value of the groups of this study was for the group b while the highest caries depth mean value of the groups of this study was for the group d (table 1). the result of anova test showed that there was high statistical significant difference among these groups. lsd test also revealed statistically significant differences between each two groups (table 2) , all the treated groups have significant less caries penetration depth in comparison with the control group when p value ≤ 0.05. table 1: the descriptive statistics of the experimental groups group n mean ± sd min. max. a 10 16 2.2 15 17 b 10 9.4 0.84 8 10 c 10 11.4 1.07 10 13 d 10 18.7 1.93 16 22 table 2: lsd between each paired group histopathological study: the histopathological finding of the examined groups demonstrated a carious lesion size graduating from large to small in correspondence with the fluoride defense measures abilities against demineralization utilized in this study being the largest in the control group followed by group a (apf) then by group c (stannous and sodium phosphate fluoride) and finally the smallest lesion was found in the rmgic group b. group a exhibited an identified carious lesion between the enamel and dentine, for group b the area was represented by fine lines of demineralization diffused in remineralization layers that penetrated by the rmgic whereas in group c a small isolated area of dark lesion overlaid by fluoridated mineralized area can be seen. group d showed dark demineralization zone extends to dentine enamel junction, as can be seen in the figures 2,3,4,5. enamel surface pattern in the tested groups: variations in enamel surface pattern were shown in the results of this study. group a has 40% of type iv of enamel surface , 40% of type v of enamel surface and 20% of type i of enamel surface while the group b has 60% of type iv of enamel surface , 40% of type v of enamel surface , while the group c has 80% of type v of enamel surface , 20% of type iv of enamel surface also the results showed that the group d has 60% of type iv of enamel surface , 20% of type iii of enamel surface and 20% of type v of enamel surface. discussion fluoride and fluoridated agents was the corner stone of defense mechanism against this decalcification surrounding the brackets that could be of irreversible type and threaten the esthetic success achieved with orthodontic treatment necessating additional operative work. the use of fluoride is one of the most studied, known and effective methods to prevent dental caries. the anti carious activity of topical fluoride has been attributed to its greater effect in the prevention of enamel decalcification rather than the remineralization of existing lesions due to its considerable capacity to reduce the minerals solubility in the enamel crystal lattice during acid challenge. (27) to the best of our knowledge, this study is the first comparison of these topical agents against enamel demineralization around orthodontic brackets in vitro condition by measuring lesion depth. in the present study; by comparing to the control group all fluoride treated groups revealed statistically significant differences for artificial caries depth. the tested materials showed less mean lesion depth values that indicated less mineral loss than the control group. however, these significant differences vary among the first group second group sig. group a group b .000 group a group c .000 group a group d .010 group b group c .046 group b group d .000 group c group d .000 figure 1: a; view of tooth profile illustrate areas of artificial lesion on buccal surface. b; enlarged artificial lesion demonstrating the three depth measurement at the centre j bagh college dentistry vol. 28(2), june 2016 comparative assessment pedodontics, orthodontics and preventive dentistry 130 analyzed elements according to the preventive measure during the experimental phases, being the less subsurface lesion depth in group b followed by group c, then group a and finally the figure 4: group c. a..view for enamel surface (e) shows opaque area of minerlization and a lesion (arrow) shows blue stains ground x4. b.. magnifying view for figure b shows enamel (e) and deminerlized lesion (dml).x10 c..surface morphology of tooth enamel treated with stannous flouride shows smooth zone (sz), fine porosities (arrow head, and occasional fine fissuring (arrows).x4 a t b t c t figure 3: group b.. a. a.. rectangle demarked area of deminerlized lesion of blue stains .x 4, b.. magnifying view for previous figure a shows localized (blue) unminerlized lesion (arrow head), over layed with sparses thin hybrid-like ufine layer of infiltrated applied material (arrows).x10 c.. longitudinal ground section for enamel tooth pretreatment with rmgic shows dark deminerlized lines interdigited with reminerlized layers of translucent shiny lines (arrows) .x4 a cb figure 2: group a. a.. photomicrograph view for enamel pretreated with apf shows lesion (arrow) in between enamel (e) and dentine (d). x4 b. pitted, porous enamel surface (arrow). x4 c.. other view shows glabular apposition of remineralizing matrix (arrows) with in between a deminerlized dark area (arrows heads). x10 a cb figure 5: group d. a.. photomicrograph view for surface enamel of control group, showed dark demineralization zone extends to dentine enamel junction (arrow head). b.. longitudinal ground section shows extension of lesion (arrow) with rough pitted enamel. x4 a b j bagh college dentistry vol. 28(2), june 2016 comparative assessment pedodontics, orthodontics and preventive dentistry 131 control group, making the best lesion fighting measure is rmgic 49% lesion depth reduction, as it well approved that this material can deliver regular amount of fluoride over months which provide excellent anti-caries activity during the prolong acidic exposure of examined enamel during this study. this superior antidemineralizing activity of rmgic to other tested groups was agreed with several studies. (23, 28, 29) the rmgic effect against decalcification was evaluated in researches with various methods, schmit et al (28) found 50% smaller mean lesion depths at rmgi bonded groups when compared with the composite resin group in a comparable acid attack period to this study. uysal et al (29) used a pen-type laser fluorescence device (diagno-dent pen) for demineralization evaluations, the rmgic released fluoride changed the ratio between demineralization and remineralization reducing the lesions progression significantly more than the fluoride from the materials used in the other groups. polychromatic cone-beam microtomographic system and depth measurement were utilized by paschos et al (23) and also fuji ortho lc (rmgic) was found to have significantly smaller lesion depth and less mineral loss in comparison with the other materials that comes in agreement with this study. the result of group a showed 14% reduction in lesion depth in agreement with esteves oliveira et al (30) who assessed the apf effect on caries lesion progression inhibition and recorded 44% depth reduction, also a study by mathew et al (31) reported 43% reduction in acid solubility in comparison to the control group by comparing the quantity of calcium dissolution into the demineralization solution using atomic emission spectrometry, the acidic challenge was for 24 h after 4 min of 1.23 also villena et al(32) found apf gel application for one and four minute reduced mineral loss by 13% after 28 day of cariogenic challenge. fluoride anticaries effect related to the reaction products formed on enamel during the professional treatment and their retention over time after the application, fluoride concentration released from 4 min apf application was reduced by 34% after 28 day of caries challenge, this reduction has been found in vitro (33,34) and in vivo (35) and is due to the release of loosely bound f formed on enamel by apf treatment to the oral environment (36) this would give good explanation to the lower anti caries capacity of apf compared to the sustained f release of rmgic mentioned above, and frequent application of f in group c. a 0.4% stannous fluoride gels scored 39% reduction in enamel demineralization. a study by boyd (14) compared the use of a 1100 ppm fluoride tooth paste alone or together with either a daily 0.05% naf rinse or 0.4% snf2 gel applied twice daily. he found 29% reduction in the demineralization of 0.4 % snf2 children brushed teeth compared to the 0.05 naf, and both solutions provided additional protection against demineralization when compared to toothpaste. recently, many investigations studied extensively solutions containing different concentrations of snf2 or combinations of different fluorides with sncl2. hjortsjö et al (37) tested the effect of one minute exposure to a 0.78% w/v snf2 solution in a vivo model and found 67% enamel dissolution reduction after one min exposure to citric acid. however, the effect did not last for more than 1 day. (38) in an in vitro study using sncl2 as the source of tin with amine fluoride and/or naf as the source of fluoride., such solutions reduced tissue loss significantly, even when using a severe erosion cycle (15). in an in situ model, used sncl2 mouth rinse yield 1,900 mg/kg sn, naf and amine fluoride yield 1,000 mg/kg f used once a day reduced erosive wear of enamel by 73%. (39) tin is thought to work through the incorporation into the surface enamel and/or the formation of a tin containing uppermost layers of the enamel (16, 40), the 39% artificial caries depth reduction presented by group c in this study would be supported by the above discussed studies investigated the snf2 effect on enamel acid resistance yet they can't mirror this study because either the experimental solution and/or the measuring procedures quite differ. also the caries depth reduction significantly less than group b might be related to that f ion released from rmgic is higher per day, whereas group c were significantly less caries depth penetration than apf group might be related to the frequent application and additional preventive effect yielded by tin precipitated layer provide by (0.4% stannous fluoride, 1% sodium fluoride) gel in group c. an over view of the histopathological examination clearly revealed that the less caries depth groups the more mineralization deposit, on the other hand the histopathological scores showed that only group c has the majority of smooth flat uniform surface while the rest of the experimental groups have pitting surface score iv of a considerable percentage, indicating that there was a poor relation between the mean caries depth and amount of surface roughness, this study revealed that the three tried fluoridated measures were successfully able to reduce enamel dissolution. j bagh college dentistry vol. 28(2), june 2016 comparative assessment pedodontics, orthodontics and preventive dentistry 132 references 1. basdra ek, huber h, komposch. fluoride released from orthodontic bonding agents alters the enamel surface and inhibits enamel demineralization in vitro. am j orthod dentofac orthop 1996;109:466-72. 2. rosenbloom rg, tinanoff n. salivary streptococcus mutanslevels in patients before, during, and after orthodontic treatment.a m j orthod dentofacial orthop 1991; 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87:1032-6. 37. hjortsjö c, jonski g, thrane ps, saxegaard e, young a. the effects of acidic fluoride solutions on early enamel erosion in vivo. caries res 2009; 43: 126–31. 38. hjortsjö c, jonski g, thrane ps, saxegaard e, young a. effect of stannous fluoride and dilute hydrochloric acid on early enamel ero-sion over time in vivo. caries res 2009; 43: 449–54. 39. schlueter n, klimek j, ganss c. efficacy of an experimental tin-f-containing solution in erosive tissue loss in enamel and dentine in situ. caries res 2009; 43: 415–21. 40. yu h, attin t, wiegand a, buchalla w. effects of various fluoride solutions on enamel erosion in vitro. caries res 2010; 44: 390–401. j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 59 retentive forces, tensile strength and deflection fatigue of acetal thermoplastic clasp material in comparison with cobalt-chromium alloy samar s. alwan, b.d.s. (1) intisar j. ismail, b.d.s., m.sc., ph.d. (2) abstract background: nowadays there is an increasing of the emphasis on aesthetic, dentist have been concerned about providing aesthetics and functional removable partial dentures to their patients and this was make the mission more difficult because of the goal now is achieving optimal aesthetic of the denture while maintaining retentive, stable, and conservative to the health of supporting tooth and supporting tissue. the traditional use of metal clasp like cobalt-chromium, gold, stainless-steel and titanium hampers esthetics because of its obvious display conflicts with patient’s prosthetic confidentiality. acetal resin (poly oxy methylene) may be used as alternative denture clasp material. this material was promoted primarily on the basis of its superior esthetic. material and method: in this study, acetal resin of flexite and co-cr alloy of wirocast companies were used. four metal models of two premolars and two molars were surveyed to have 0.25mm and 0.5mm undercut depth for each one of the materials. eighty clasps were prepared and tested by testing machine to measure the load required to dislodge acetal and co-cr clasps of 2mm. thickness (for premolar and molar). tensile test were utilized for both acetal resin and co-cr. tensile values will be used in special formula to calculate the amount of deflection. results: the results of this study revealed that acetal resin clasp of molar with 0.5mm undercut depth have the higher retentive force, and premolar with 0.25 mm undercut depth have the lowest retentive force as compared to co-cr. also acetal had lower values of the tensile strength as compared to co-cr alloy but it had higher deflection value than co-cr and it can withstand higher deflections than those of co-cr before having permanent deformation or fracture conclusions: acetal resin can be used with limitation as an alternative to co-cr alloy clasps in removable partial dentures. key words: acetal resins, aesthetic, fatigue, tensile strength. (j bagh coll dentistry 2014; 26(1):59-66). introduction patient demands a removable partial denture for health, anatomic, psychological or financial reasons. patients often cite lack of retention and poor esthetics as a reason for not wearing their partial dentures. metal display on anterior teeth was often unacceptable (1). aesthetically pleasing removable partial denture (rpd) is a partial denture that blends in with the natural dentition and the one that does not show any indications of being a removable partial denture. removable partial dentures made without a metal substructure are more aesthetically pleasing. the use of metal clasp on anterior teeth may cause esthetic problem. many methods to overcome this dilemma include the painting of clasps with tooth colored resins (2,3), use of lingual positioned clasp (4,5),engaging of mesial rather than distal undercut (6) ,and use of gingival approaching clasp. the most common alloys used for clasp are chrome-cobalt alloy, gold and titanium alloy, although these may be retentive but not esthetic (7). so the need of alternatives nowadays to overcome esthetic problems was increased. many alternatives had been introduced. (1) m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor. department of prosthodontics, college of dentistry, university of baghdad. acetal (pom) is one of the materials that used to replace metal clasps. this material had superior aesthetic and biocompatible which make it considered in the treatment of patients who are allergic to co-cr alloys or acrylic (8), but also it should provide appropriate retention when it used as alternative clasp to many others like co-cr, gold, acrylic removable prostheses. also it should have enough mechanical properties to withstand forces and environment of oral cavity and have appropriate life time within this environment because clasp of any removable prosthesis will subjected to many forces and cyclic bending during insertion, removal and during mastication which make the retentive clasp arm the most part to be damaged (9). materials and methods four wax models were prepared by taking silicon impression to premolar and molar models. then the impression was poured with crown and bridge wax, four wax models of two premolars and two molars were surveyed to have 0.25mm and 0.5mm undercut depth for each one of them. these wax models was casted to metal. then these models was duplicated with poly vinyl siloxsane duplicating material and then poured with type iv stone for waxing and injecting of acetal clasps, while it was invested with j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 60 phosphatebonded investment material, for waxing and casting of co-cr. figure 1: wax models and surveying on the dental surveyor for undercut adjustment. figure 2: wax models after casting by crown and bridge metal. b. duplication of the metal models by poly vinyl siloxane duplicating material. ready-made clasps of 2 mm thickness were waxed on the stone and investment models. stone models with readymade clasp have been flasked with the special flask of the device and boiled in hot water for about 30 minute injected with acetal by thermoplastic injection machine. (flexite, u.s.a., gn 30 pneupress). figure 3: acetal flexite injection machine. a b j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 61 the phosphate bonded investment models have been flasked and casted with co-cr metal type wirocast-germany. eighty clasps were prepared, forty clasps of acetal and forty for co-cr clasps. the clasps were tested with tinius-olsen universal testing machine to measure the load required to dislodge acetal clasps and co-cr clasps of 2 mm. thickness (for premolar and molar) and two different undercut depths (0.25 and 0.5mm) from the metal models. the values for both materials were compared. beside the retentive force, a comparison of the tensile test and the amount of deflection needed to deform acetal resin and co-cr samples was done. tensile dumbbell shape samples were prepared for both acetal resin and co-cr according to astm 638/type v/2. the samples were prepared in the same technique of clasps preparation. ten samples have been prepared five for acetal group and five for co-cr. figure 4: testing procedure of acetal and co-cr clasps, figure 5: testing procedure of acetal and co-cr tensile samples. results the results revealed that cr-co alloy clasp had higher retentive force values in comparison with acetal thermoplastic clasp. for co-cr group, results showed that retentive force mean were 13.05n and 17.61n for premolar teeth with 0.25mm and 0.5mm respectively. while for molar teeth it was 16.96n and 24.79n for 0.25mm and 0.5 mm undercut respectively. the premolar group showed that 0.25mm undercut premolar had the lowest value of (13.05n) of the retentive force. j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 62 figure 6: histogram show subgroup difference of premolar teeth with different undercut in co-cr type. figure 7: histogram of subgroup difference of molar teeth with different undercut in co-cr type. for acetal group specimen, also molar with 0.5 mm undercut showed the higher retentive force while premolar with 0.25 mm undercut showed the least one. careful analysis by t-test was used also to compare the retentive force. the statistical analysis showed also a very highly significant difference in the retentive force of acetal clasp between 0.25mm and 0.5mm under cut depth for both premolar and molar groups. figure 8: histogram of show subgroup difference of premolar teeth with different undercut in acetal type. j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 63 figure 9: histogram show subgroup difference of molar teeth with different undercut in acetal type. figure 10: tensile strength difference between co-cr and acetal. tensile strength of cr-co and acetal samples co-cr samples was showed higher tensile strength mean (659.2 mpa) while acetal samples showed lesser values of (55.232 mpa). deflection of co-cr and acetal the resulted data showed that metal co-cr have lesser mean deflection (0.65mm) as compared to acetal that had higher mean deflection (4.22mm). figure 11: histogram showed deflection difference between acetal and co-cr. j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 64 discussion retentive force acetal resin is marketed for direct retainers attached to co-cr r.p.d.f ramework, as well as supportive frame in r.p.d. acetal resin has a relatively high proportional limit with little viscous flow, enabling it to behave elastically over a large enough range to be used as a material for clasp fabrication (10) . according to fitton et al who stated that to gain adequate retention from acetal clasps, the clasp should have a greater crosssectional area than metal clasp and this study was confirm these findings. therefor a 2mm thickness of clasp was used for comparison in this study. the thicknesses of clasps were used with the same length of clasp for both acetal and co-cr due to several reasons: a, to standardize the study group .b, to give acetal clasps diameter greater than 1.4mm in diameter. c, this diameter was used for both acetal and co-cr because there was a theory of that a greater retention would be expected for acetal resin clasps in the proposed models since reciprocal arms were made in cocr alloy. it would be a new way to use acetal resin to make r.p.d. clasp (11) according to bates (16) who stated that the assessment of stress in the retentive clasp arm would depend on the degree of undercut used together with the form of the clasps, and the mechanical properties of the alloy used. therefore two gauges of the undercut have been used 0.25 mm and 0.5 mm in molar and premolar. in concerning the retentive force of acetal resin clasps in the present study, it was found that molar with 0.5 mm. undercut of acetal clasp had the higher mean retentive force (1. 99n.) and this value was not very higher than retentive force in premolar with 0.5mm. (1.87n.) and it was higher than premolar with 0.25mm. (0.88n.). so this study was partially agreed with turner et al (8) who suggested that in clinical use, acetal resin clasps should have shorter length, a relatively larger cross-sectional area and engage deeper undercut to have adequate retention. that mean premolar clasp should have greater retention force according to turner et al theory, but the results of this study showed that decreasing of the length in premolar than that of molar has constricted effect not very highly effect and values of the retentive force for both premolar and molar which were still within the same range. also this study was not agreed with arda and arikan (11) who suggested that the retentive force of premolar with 0.5 and 0.25mm is higher than molar teeth because of the shorter length of clasp. conversely there was non-significant difference between molar and premolar acetal clasps in both groups of undercut depth 0.5 and 0.25mm. for the effect of different tooth types molar or premolar, in molar teeth, acetal clasp had higher retentive force than those in premolar teeth in both depth of undercuts 0.25 and 0.5mm that mean the longer the clasp was the more retentive force, but turner et al (8) and arda and arikan (11) and stated that because of the flexibility of acetal resin clasp, it should be shorter than co-cr conventional clasp and higher cross-sectional area. they stated that in premolar teeth, acetal had higher retentive force than molar teeth, so this study was not agreed with the theory of turner et al (8) and arda and arikan (11) who focus on the flexibility of acetal which constrict the shortening effect of the clasp and agreed with this study. according to these theory multiple acetal clasp can be used in r.p.d. design to reach the needed amount of retention and this was agreed with lekha et al (12) conclusions statement that acetal resin provide less retention compared to cr-co. so further studying have to be done regarding various thickness and designs of clasps and frame work for its successful dental application (13). tensile strength in concerning the result showed that the mean tensile force of acetal was lower than that of crco samples. according to craig’s and power, the microstructure of any substance is the basic factor that its control properties. a change in physical properties of a material is a strong indication that there must have been some alteration in its microstructure. acetal resin as a polymer had a behavior fundamentally different from both ceramics and metals, so when chains of polyoxymethylene are aligned parallel to one another are subjected to tensile stress along their long axis. the stress required to stretch the atoms in the chains was surprising high. but if the stress perpendicular to the long axis of the chain it would be very low. the higher stress in the first case was caused by strong bonds between atoms within polymer chain, but the low stress in the second case because of the weak bonds between adjacent chains (14). while cr-co in the cast condition is inhomogeneous, consisting of matrix composed of a solid solution of cobalt and chromium in a cored dendritic structure. (15). cobalt and chromium are body –centered cubic unit cells which have densely packed planes of atoms in their lattice to allow plastic deformation at yield stress, thus a greater resistance to slippage is created. when this complex process was imagined, there was impression of the higher stresses needed to elongated and fracture cr-co samples (14). j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 65 deflection of crco and acetal the amount of undercut used must be less than the deflection of the clasp at which the proportional limit will not exceeded and then permanent deformation would result. this is suggested by bates who found that the minimum workable undercut is 0.25mm.an optimal degree of undercut that should be engaged by any particular clasp depend specially on the material of the clasp, other wise there will be ability to traumatize tooth upon insertion and removal and permanent deformation of the clasp (16). according to the definition, the clasp would be deflected multiple times each day and there is a large relation between the amount of deflection and number of deflections on the fatigue of the clasp because the amount of deflection and number of cycles affect the propagation of fatigue process and fatigue process is an acumulative process. clinically repeated deflection of the clasp is occur during insertion and removal of the clasp from the tooth. this may cause clasps fatigue and fracture (7,17). results showed that the mean deflection of acetal resin (4.22 mm.) was higher than those of co-cr samples (0.65mm). in this study, the results were revealed that if a crco clasps was subjected to cyclic bending in minimum deflection, fatigue and fructure failure is not likely to occur which is in agreement with previous clinical observations of harocourt and brock and other fatigue testing like earn show, asgar and peton, morris et al, bridgeman et al (21,22,9,19). but adeflection of 0.5-0.6 could cause permenant deformation in the clasp especially with increasing number of stress during insertion and removal of the denture and this will give another disadvantages of using co-cr in deep undercut according to bates (16) not only because of increase stress of the abutment tooth. but it would cause permenant deformation of the clasp because the amount of deflections during insertion and removal will exceed the proportional limit of the material (16,18,19). on the other hand acetal resin clasps have higher flexibility and higher deflections which represent greater resistance to fatigue of clasps during daily insertion and removal; because of its wide range of deflection below acetal proportional limit when compared to cr-co ones which allow the retentive clasp arm to be placed in deeper undercuts on abutment. these results were agreed with sykes et al (1) and arda –arikan (11). also, this greatest deflection without stress on the abutment of acetal resin could be good property to indicate its ability to be used on periodontally compromised teeth and this is agrement with sykes et al and vondenbrink et al (1,20) as conclusions 1. acetal resin can be used with limitation as an alternative to co-cr alloy clasps in removable partial dentures. 2. the mean retentive force required to remove acetal resin clasp was found to be significantly lower than those required to remove co-cr clasp. 3. acetal resin can be used as an alternative for co-cr clasp in periodontally compromised patients because acetal has lesser stress on the abutment tooth. 4. acetal resin clasps can be used as an alternative for co-cr clasp in molar tooth with 0.5mm. depth of undercut where the use of co-cr clasp may lead to unwanted tooth movement. 5. acetal resin samples had less tensile strength as compared to co-cr samples. 6. acetal resin samples had higher values of deflection ranges as compared to co-cr samples which enable acetal to withstand higher deflections in clinical uses without changes or permanent deformations or fracture. references 1. sykes lm, dullabh hd, chandler hd, bunn b. flexibility of techno polymer clasps compared with cobalt-chromium and titanium clasps. sadj 2002; 57: 166-71. 2. moreno dm, garcia ld, rudda kd. camouflaging partial denture clasp. j prosthet dent 1986; 55:65660. 3. ozcan m. the use of chair side silica coating for different dental applications: a clinical report. j prosthet dent 2002; 87:469-72. 4. highton r, caputo a, matyas jf transmission and retentive capabilities utilizing labial and partial i-bar partial dentures. j oral rehabil 1987; 14: 489-99. 5. pardo –mindan s, ruiz-villandlego jc. a flexible lingual clasp as an aesthetic alternative: a clinical report j prosthet dent 1993; 69:245-6. 6. chow tw, clark rk, clarke da, ho gf. a rotational path of insertion for kennedyclass iv removable partial dentures. br dent j 1988; 164:1803. 7. vallittu pk, kokkonen m. deflection fatigue of cobalt-chromium, titanium and gold alloy cast denture clasp. j prosthet dent 1995; 74: 412-21. 8. turner jw, radford dr, sherriff m. flexural properties and surface finishing of acetal resin denture clasps. j prosthodont 1999; 8:188-95. 9. morris hf. asgar k, tillitson e. stress relaxation testing. part 1: a new approach to the testing of r.p.d alloys, wrought wires and clasp behavior. j prosthetic dent 1981; 46(2): 133-41. 10. fitton ls, davies eh, howlett ja, pearson gj. the physical properties of poly acetal denture resin. 1994; 17:125-9. 11. arda t, arikan a. an in vitro comparison of retentive force and deformation of acetal resin and j bagh college dentistry vol. 26(1), march 2014 retentive forces restorative dentistry 66 cobalt chromium clasps. j prosthet dent 2005; 94; 267-74. 12. lekha k, savitha np, roseline m, nadiger rk. acetal resin as an esthetic clasp material. j interdisciplinary dentistry 2012; 2: 11-14 13. gettaleman l, nathanson d, nyerson rl: effect of rapid curing procedure on polymer implant material. j prosthet dent 1977; 37: 47-82. 14. o’brien wj. dental material and their selection. 3rd ed. quintessence publishing co., inc.; 2002. 15. powers jm, sakaguchi rl. craig’s restorative dental materials. 12th ed. st. louis: mosby elsevier; 2006. 16. bates jf. the mechanical properties of cobaltchromium alloys and their relation to partial denture design. br dent j 1965; 119(9): 389-96. 17. mahmood a, wakabayashi n, taka hh, ohyama t. deflection fatigue of ti-6al-7nb, co-cr and alloy cast clasps. j prosthet dent 2005; 93:183-8. 18. ghani f, mahmood ma. laboratory examination of the behavior of cast cobaltchromium clasps. j oral rehabil 1990; 17: 229-37. 19. bridgeman jt, marker va, hummel sk, benson bw, pace ll. comparison of titanium and cobalt chromium removable partial denture clasps. j prosthet dent 1997; 78:187-93. 20. vandin brink jp, wolfaardt jf, faulkper mg. a comparison of various removable partial denture clasp materials and fabrication procedures for placing clasp on canine and premolar teeth. j prosthet dent 1993; 70: 180-8 21. earnshow r. fatigue test on dental cobalt-chromium alloy. br dent j 1961: 110(10): 341-5. 22. asgar k, peyton fa. the effect of casting conditions on some mechanical properties of cobalt base alloys. j dent res 1961; 40: 73-86. inas final.doc j bagh college dentistry vol. 26(2), june 2014 the influence of follow up up restorative dentistry 12 the influence of recent adhesive onlay fabrication techniques on the fracture resistance of endodontically treated premolars (an in vitro study) zainab shaker al-taii, b.d.s., h.d.d. (1) inas i. al-rawi, b.d.s, m.sc. (2) abstract background: endodontically treated teeth have low resistance to fracture against occlusal forces. the strengthening effect of bonded esthetic onlay restoration on weakened tooth has been reported. this study aimed to assess the fracture resistance of endodontically treated premolars restored with composite with and without cuspal coverage by using direct and indirect techniques. indirect technique done by cad/cam system (computer aided design – computer aided manufacturer) and laboratory processing. material and methods: forty human extracted maxillary premolars of approximately comparable sizes were divided into four groups: group (a): ten endodontically treated teeth directly filled with filtek z250xt without cuspal coverage. group (b): ten endodontically treated teeth prepared with onlay cavities and restored directly with filtek z250 xt. group(c): ten endodontically treated teeth prepared with onlay cavities and restored indirectly with filtek z250 xt. group (d): ten endodontically treated teeth prepared with onlay cavities and restored indirectly with paradigm mz100 cad/cam blocks. fracture strength of the samples was measured by using universal testing machine (an axial compression test). data were analyzed statistically by one way anova test and least significant difference test, results showed that group a has the lowest fracture resistance value than all experimental groups and the difference are highly significant. while group b has a high significant fracture resistant value than the indirectly restored groups. group c and group d showed an approximate fracture resistant result (1.13kn and 1.07kn respectively) and the difference is statistically not significant. conclusion all cad/cam composite onlay, indirect filtek z250 xt and direct cuspal coverage survived maximum biting force for posterior single tooth, so these types of onlays provide good reinforcement in an extensive mod cavities in premolars the mode of fracture for group d was 90% restorable which is higher than group c (80%) restorable and group b (30%) restorable type of fracture. key words: fracture resistance, filtek z250 xt, cad/cam composite, cuspal coverage. (j bagh coll dentistry 2014; 26(2): 12-17). introduction endodontically treated teeth may have a considerably reduced capacity to resist functional forces, and this may be a attributed to the loss tooth structure beside loss of inherent dentinal fluid which may affect in tooth properties making it weaker 1 the classical treatment is to build up the tooth with a post and core but, these teeth are generally weaker and would increase the risk of fracture due to more dentine removed (1, 2). cuspal coverage in endodontically treated tooth have a good prognosis with preference toward the partial coverage (onlay) rather than full coverage (crown), the direct adhesive composite resin used to restore teeth is the potential for a more conservative cavity preparation with less reliance on mechanical retention (3) but with shortcoming of polymerization shrinkage that leads to marginal defect and gaps problems like microleakage and wear, the indirect composite resin restoration reduce the shortcoming of direct restoration that it control occlusal and proximal contact points, minimal polymerization shrinkage due to cement agents, good polishing and finishing possibilities (4). (1)master student. department of conservative dentistry. college of dentistry, university of baghdad. (2)professor. department of conservative dentistry. college of dentistry, university of baghdad the introduction of digital dentistry and, with that, of computer aided design/computer assisted manufacturing, enable additional application. materials and methods teeth selection criteria forty sound human maxillary first premolars with two separated roots extracted for orthodontic reasons were used. teeth were cleaned, stored in thymol solution at 0.1% teeth dimensions were between (9.0-10.0mm)for buccolingual and (7.07.9mm) for mesiodistal and (8.5-9.5mm) for occlusoapical. every tooth was examined under a 10x for cracks or fractures and embedded into acrylic 2.0 mm below the cementoenamel junction. samples grouping the experimental teeth were divided into 4 groups, ten teeth each as follow group (a): ten endodontically treated teeth filled with filtek z250 xt without cuspal coverage. group (b): ten endodontically treated teeth prepared with onlay cavity and restored directly with filtek z250 xt. j bagh college dentistry vol. 26(2), june 2014 the influence of follow up up restorative dentistry 13 group (c): ten endodontically treated teeth prepared with onlay cavity and restored indirectly with filtek z250 xt. group (d): ten endodontically treated teeth prepared with onlay cavity and restored with paradigm mz 100 blocks impression for the teeth before preparation for group b and c was to fabricate the model that were subjected to crown coping with a copyplast and biostar machine to get silicon matrix (template) which is identical to the cusps of each individual tooth all the teeth in all groups were endodontically treated with protaper system up to size f2, after obturation completed, glass ionomer cement was used as barrier to the ingress of fluid (5-7). cusp reduction (cutting) each tooth in groups b, c and d was subjected to cusp cutting (reduction) to 3.0 from the buccal cusp (8) with slow speed diamond machine under cooling water cavity preparation for group a the glass liner was removed from the access opening to about (6mm) measured from the cusp tip to the depth of the cavity creating flat floor (9). each tooth in group b, c and d was subjected to a preparation of onlay cavity, with a water cooled high speed hand piece, with round ended tapered diamond bur (no.8845kr.314.018) that were replaced every five preparations (10). mod cavities were prepared in (3mm) depth, (3mm) width with diverged wall in (10º) occlusally, all walls were without undercut and were flared, the cavosurface line angles were (90º) and all the internal line angles were rounded (11). as shown figure (1) cavity preparations were standardized using a modified dental surveyor and all the cavity dimensions were measured using digital caliper. master model fabrication impressions of the prepared teeth in group c and group d was done in an individual plastic tray (12) and poured with distone to fabricate the master cast in which the filling will be fabricated. filling the samples group (a): applying a single bond universal adhesive (scotch bond) (3m) and the filling material (filtek z250 xt) was placed till the whole access opening was completely filled (three layers). group (b): filled directly with composite material (filtek z250 xt) by first single bond universal adhesive (scotch bond) and the restoration was fabricated in a layering mode of with the final layer was made with the aid of the template (copyplast) to reconstruct the original occlusal anatomy of the tooth(9). group (c): layer of separating medium was applied to the cast before margination. then the filling material (filtek z250 xt) was added horizontally on the tooth with aid of template then the final restoration was cemented to the samples with the self adhesive resin cement (rely x unicem 2) after being smoothed and polished. group (d): a cad/cam device (cerec3; cerec inlab mc xl sirona dental systems gmbh, germany) scanning and milling machine (figure 2) and software (version 3.10) was used to fabricate the onlays. figure 2: inlab mc-xl milling machine. after fabrication of the model, each specimen was scanned with ineos scanner; ips contrast spray lab side (cerecoptsispray) was sprayed on the model and scanned as in figure 3. the whole margins of the cavity was marked accurately on the model of the three dimensional picture (margination of the cavity) as in (figure4). then restoration was filled the scanned tooth cavity and the virtual restoration was displayed in the monitor and viewed from all surfaces (figure 5). figure 1: dimensions of the preparation j bagh college dentistry vol. 26(2), june 2014 the influence of follow up up restorative dentistry 14 the paradigm mz100 block was inserted in the milling device, milling started by clicking mill button for fabrication of the onlay from composite blocks in the milling device, after the milling procedure was completed and the onlay was fabricated, the restoration spur was removed, all onlays were checked for fitting on the samples and cemented with (rely x unicem2) as in group c. results fracture resistance values of all experimental groups the descriptive statistics which represent the mean, standard deviation (±sd) with the maximum (max) and minimum (min) values of the fracture resistance in (kn) are shown in (table 1). table 1: descriptive statistics of the fracture resistance of each group in kn groups mean ± sd max min group a 0.67 0.13 0.9 0.5 group b 1.65 0.27 2.01 1.236 group c 1.13 0.15 1.35 0.91 group d 1.07 0.18 1.29 0.78 endodontically treated teeth with only access opening filled presented the lowest mean value (0.67), while endodontically treated teeth with indirect cuspal coverage showed the highest resistance to fracture (1.65). one way anova test detected statistically high significant differences among experimental groups (table2). table 2: one way anova test of fracture resistance among all groups comparison sum of squares df mean square f-test p-value between groups 4.79 3 1.6 44.61 0.000 within groups 1.29 36 0.04 total 6.07 39 comparison between each two groups least significant difference (lsd)test was performed , it is clear from (figure 6) that teeth restored with direct restoration (filtek z250 xt) (group b) had more fracture resistance than all experimental groups and the results are highly significant. endodontically treated teeth without cuspal coverage(group a) showed the least fracture resistance value than group (c and d) and the results are highly significant, teeth restored indirectly with filtek z250 xt presented more resistance to fracture than teeth restored with paradigm mz100block cad/cam but the values are not significant. figure 6: lsd test between each two groups mode of fracture group (a) (60%) of the fracture involving half of the tooth above the c.e.j (type iii) while in group (b) (70%) of the fracture was below the c.e.j. (type iv) which is non restorable and (30%) restorable, (10%) isolated fracture of the restoration (type i) and (20%) of the fracture involving half of the tooth above the c.e.j (type iii), group (c) (80%) restorable fracture, (60%) isolated fracture of the restoration and (20%) of the fractures of the samples above c.e.j (type iii) and (20%) of the fractures below the c.e.j (type iv) which are non restorable and lastly in group (d) (90%) is restorable fracture, ((80%) isolated figure 3: scanning the model figure 4: margination of the cavity figure 5: filling and shaping the restoration j bagh college dentistry vol. 26(2), june 2014 the influence of follow up up restorative dentistry 15 fracture of the restoration (type i) and (10%) fracture involving half of the tooth above c.e.j). (type iii) and (10%) non restorable fracture involving half of the tooth below c.e.j.(type iv) as in table 3. table 3: mode of fracture in each group groups isolated fracture of restoration (type i) fracture involving a small tooth portion (type ii) fracture involving half of tooth above the c e j (type iii) fracture below the c e j (type iv) group a 0 4 6 0 group b 1 0 2 7 group c 6 0 2 2 group d 8 0 1 1 discussion fracture resistance among all experimental groups there was a highly significant difference among all experimental groups (table2). group a (endodontically treated teeth without cuspal coverage restoration) has the lowest fracture resistance mean value which is (0.67 kn); this come in agree with many researches (9, 8, 13-15) the statistical analysis using anova test (table 2) showed highly significant difference with other three groups, due to that the teeth with endodontic treatment are severely weakened due to the loss of reinforcing structures during access opening and instrumentation. the fracture is directly related to the amount of dentine lost and the continuity of the enamel which is broken and decrease in the moisture of the tooth after endodontic treatment. group b has the highest fracture resistance mean value than group c and group d and the difference is highly significant. this agrees with many findings (11,15,17). that the difference in fracture resistant between group b and group c may be related to the difference in the adhesive materials and the difference in c factor between the two groups. in group b (scotch bond adhesive material) have shear bond strength which is about (30mpa) with dentine and (24mpa) with enamel with the formation of a continuum between tooth surfaces and adhesive material (1720). while the shear bond strength of the cement (relyx unicem 2) with dentine is about (19mpa) and with enamel is about (26mpa), it is less than that of the scotch bond. whereas group b fractures strength is higher than that of group d may be due to the physical properties of the two materials that the filtek z250 xt which have fracture toughness (2.2k1c) that means it has higher load absorber as compared with paradigm mz100 composite block which have fracture toughness of about (1.4k1c). the result disagrees with giordano (21) who stated that paradigm mz100 is a resin based composite with micrometer and submicrometer zirconiasilica fillers, its block form has mechanical properties superior to those of the conventional z100 restorative direct resin-based composite, as well as to other direct resin-based composites. the fracture strength of group c is higher than group d but the values are statistically not significant, this agree with other findings (22-24), this is because of the use of the same luting cement (rely x unicem2) in bonding both restorations which reinforce the composite in both groups to the same degree (25) but disagree with giordano and jansen (21,26) who stated that the cerec system uses materials that have several benefits with respect to wear kindness, longevity and reinforcement of the tooth. it was found clinically that maximum biting force was approximately (725n) for posterior single tooth, the fracture loads in this study exceeded maximal biting forces, but it can represent some overloading situations for example bruxism or traumatic occlusion (27), in this investigation the direct composite restoration with cuspal coverage and indirect composite onlay and cad/cam onlays with (20%) of endodonticaly treated teeth without cuspal coverage survived this force so that these three types of restorations considered to be reinforcing an extensive cavities in endodontically treated premolars (9). the minimum force that cause fracture to sound premolar tooth in vitro (0.903kn-1.31kn) (28, 29) had been reached in this study for about (10%) of the samples of group a, (100%) of the samples of group b, (100%) of the samples of group c and (90%) of group d modes of fracture the analysis of failure patterns demonstrated that if failure occurred in the restorations is better in the clinical situation, because the restoration could be replaced, while tooth failure may impair the prognosis (30, 31). in group a (40%) of fracture is of type ii and (60%) of type iii this is due to the applied load j bagh college dentistry vol. 26(2), june 2014 the influence of follow up up restorative dentistry 16 will stress the tooth structure directly and the anatomy of the tooth tend to separate the buccal and palatal cusps under occlusal load (9). while in group b (70%) of type iv and the other 30% type i and type iii which are restorable type of fracture, this could be explained that the bonding mechanism of self etch adhesive is based on the simultaneous etching and priming of enamel and dentin without rinsing, forming a continuum in the substrate and incorporating smear plugs into the resin (18). indirect filtek z250 xt composite onlay (group c) have (60%) type i and (20%) type iii so (80%) of fracture is restorable and only (20%) is type iv that is non restorable. this is due to that the cement upon curing will lead to shrinkage) (20) that are detrimental for the bonded interfaces or even the cohesive strength of the cement. so when the fracture began in the restoration will ended in the cement region due to the dispersal of the fracture energy in it and might reduce the potential for crack propagation (32); this situation minimize the tooth fracture in group c (20%) compared with group b (70%). in group d (80%) type i and (10%) type iii so (90%) of the fracture are restorable fracture and only (10%) non restorable type iv. that means this group is the most favorable among other groups in preserving tooth structure. this is because fracture happened in the paradigm mz100 composite block rather than the tooth and with less value of load as compared with filtek z250 xt this could be related to the difference in the physical properties of the two materials that the paradigm mz100 composite block have fracture toughness of about (1.4 k1c) that means it is less load absorber as compared with filtek z250 xt which have fracture toughness (2.2k1c) references 1. baratieri ln, de andrada ma, arcari gm, ritter av. influence of post placement in the fracture resistance of endodontically treated incisors veneered with direct composite. j prosthet dent 2000; 84(2):180-4. 2. hussain sk, mcdonald a, moles dr. in vitro study investigating the mass of tooth structure removed following endodontic and restorative procedures. j prosthet dent 2007; 98(4):260-9. 3. baratieri ln, ritter av, predigao j, flippe la, direct posterior composite resin restoration :current concept of the technique. pract periodontic asthet dent 1998; 10(7):875-86. 4. indira md, nandlal b. comparative evaluation of the effect of cavity disinfectants on the fracture resistance of primary molars restored with indirect composite inlays: an in vitro study. j indian soc pedod prev dent 2010; 28(4):258-63. 5. bharathi g, chacko y, lakshminarayanan l. an in vitro analysis of gutta-percha removal using three different techniques. endodontol 2002; 14: 41-5. 6. lee sw, tan st, che ab aziz, za. is profile alone sufficient to remove gutta percha during endodontic re-treatment? annal dent univ malaya 2005; 1-8. 7. bueno ceds, delboni mg, araujo rad, carrara hj, cunha rs. effectiveness of rotary and hand files in gutta-percha and sealer removal using chloroform or chlorhexidine gel. braz dent j 2006; 17(2):13943. 8. magne p, knezevic a. simulated fatigue resistance of composite resin versus porcelain cad/cam overlay restorations on endodontically treated molars. quintessence int 2009; 40(2):125-33. 9. mondelli r, ishikiriama s, filho o, mondelli j. fracture resistance of weakened teeth restored with condensable resin with and without cusp coverage. j appl oral sci 2009; 17(3):161-5. 10. st-georges aj, sturdevant jr, swift ej, thompson jy. fracture resistance of prepared teeth restored with bonded inlay restoration. j prosthet dent 2003; 89(6):551-557. 11. morimoto s, vieira g f, agra c m, sesma n, gil c. fracture strength of teeth restored with ceramic inlays and overlays. braz dent j 2009; 20(2):143-8. 12. öztürk a n, i̇nan o, i̇nan e , öztürk b. microtensile bond strength of cad-cam and pressed-ceramic inlays to dentin. eur j dent 2007; 1(2): 91–6. 13. zarow m, devoto w, saracinelli m. reconstruction of endodontically treated posterior teeth--with or without post? guidelines for the dental practitioner. eur j esthet dent 2009; 4(4): 312-27 14. jiang w, bo h, yongchun g, longxing n. stress distribution in molars restored with inlays or onlays with or without endodontic treatment: a threedimensional finite element analysis. j prosthet dent 2010; 103(1):6-12. 15. kikuti w, chaves f, hipólito v, rodrigues f, d'alpino p. fracture resistance of teeth restored with different resin-based restorative systems. braz oral res 2012; 26 (3):1806-8324. 16. deliperi s, bardwell d. clinical evaluation of direct cuspal coverage with posterior composite resin restorations. j esthet restor dent 2006; 18: 256–67. 17. schneider lf, cavalcante lm, silikas n. shrinkage stresses generated during resin-composite applications: a review. j dent biomech 2010; 2010:131-630. 18. perdiga˜o j., dentin bonding as a function of dentin structure. dent clin n am 2002; 46: 277–301. 19. soares cj. martins l r m.j m g. giannini m. fracture resistance of teeth restored with indirect – composite and ceramic inlay systems. quintes intern 2004; 35 (4): 281-6. 20. eliades g, watts dc, eliades eds. dental hard tissues and bonding. germany: springer; 2005. p. 103-104. 21. giordano r. material for chairside cad/cam – produced restorations. j am dent assoc 2006; 137:14s-2s. 22. swift ej jr. processed composites. j esthet restor dent 2001; 13: 284. 23. kuijis rh, fennis wmm, kraulen cm, roeter fjm. acomparism of fatigue resistance of three materials for cusp replacing adhesive restoration. j dent 2006; 34(1):19-25. j bagh college dentistry vol. 26(2), june 2014 the influence of follow up up restorative dentistry 17 24. pallesen u, qvist v. composite resin fillings and inlays. an 11-year evaluation clin oral investig 2003; 7: 71–9. 25. radovic i, monticelli f, goracci c, vulicevic zr, ferrari m. self-adhesive resin cements: a literature review. j adhes dent 2008; 10(4):251-8. 26. jansen c. welcome to blocks party (cad/cam). daily digital dentistry 2011; 10-13. 27. ragauska a, apse p, kasjanovs v, berzina-cimdina l. influence of ceramic inlays and composite filling on fracture resistance of premolars in vitro. stomatolojia, baltic dental and maxillofacial j 2008; 10(4):121-6. 28. moezizadeh m, mokhtari n. fracture resistance of endodontically treated premolars with direct composite restorations. j conserv dent 2011; 14(3): 277-81. 29. abdullah ha, al-rawi ii. the influence of cad/cam ceramic and heat processed composite inlays on the fracture resistance of premolars. j baghdad coll dent 2012; 24(4):14-8. 30. watts dc, wilson nh, bruke fj. indirect composite preparation width and depth and tooth fracture resistance. am j dent 1995; 8(1):15-9. 31. mondelli rf, barbosa wf, mondelli j, franco eb, carvalho r. fracture strength of weakened human premolars restored with amalgam and with and without cusp coverage. am j dent 1998; 11(4):1814. 32. craig r, power j. restorative dental material. 11th ed. missouri: mosby; 2002. p. 68-109. mohammed f.doc j bagh college dentistry vol. 25(4), december 2013 the role of maxillary canines pedodontics, orthodontics and preventive dentistry109 the role of maxillary canines in forensic odontology mohammed nahidh, b.d.s., m.sc. (1) haider mohammed ali ahmed, b.d.s., m.sc. (2) abeer basim mahmoud, b.d.s., m.sc. (1) sawsan mohammad murad, b.d.s., m.sc. (3) braa' saheb mehdi, b.d.s., m.sc. (3) abstract background: this study aimed to determine the gender of a sample of iraqi adults utilizing the mesio-distal width of maxillary canines, inter-canine width and standard maxillary canine index, and to determine the percentage of dimorphism as an aid in forensic odontology. materials and methods: the sample included 200 sets of study models belong to 200 subjects (100 males and 100 females) with an age ranged between 17-23 years. the mesio-distal crown dimension was measured manually, from the contact points for the maxillary canines (both sides), in addition to the inter-canine width using digital vernier. descriptive statistics were obtained for the measurements for both genders; independent samples t-test was performed to evaluate the gender difference, percentage of dimorphism was obtained and discriminant function statistics were used for gender identification in addition to the percentages of gender identification accuracy. results: generally, the mesio-distal width of the maxillary canine and the inter-canine width were larger in males than females with a high significant difference. the accuracy of genders determination using standard maxillary canine index was 44% for males, 74% for females and 59% for the combined sample, while it was 70% for males, 76% for females and 73% for the combined sample using discriminant function statistics depending upon the canines, intercanine widths and maxillary canine index. the percentages of dimorphism were 6.13% for the canine mesio-distal width and 4.66% for the inter-canine width. conclusions: maxillary canines can be used in genders identification as an aid for forensic odontology. keywords: canine width, inter-canine width, canine index, forensic odontology. (j bagh coll dentistry 2013; 25(4):109-113). introduction teeth are the hardest and chemically most stable tissues in the body and exhibit least turnover of natural structure. they are well preserved after death. further, they show significant sexual dimorphism and are readily accessible for examination. thus, they provide excellent materials for forensic studies involving identification of genders (1). many authors have done measurements of crowns in the teeth of both men and women and found certain variations. bosset and marks (2) and krogh (3) stated that the study of the permanent mandibular and maxillary canine teeth offers certain advantages. these advantages emanate from the fact that they are the least frequently extracted teeth and being less affected by periodontal disease. the canines are commonly referred to as the ‘cornerstones‘of the dental arches as four canines are placed at the ‘corners’ of the oral cavity. the shape of the crowns, with their single pointed cusps, their locations in the mouth and the extra-anchorage furnished by the long, strongly developed roots make these canines (1)lecturer. department of orthodontics. college of dentistry, university of baghdad. (2)assistant lecturer. department of orthodontics. college of dentistry, university of baghdad. (3) orthodontist. ministry of health. resemble those of the carnivore. this resemblance to the prehensile teeth of the carnivore gives rise to the term ‘canine’. many studies (4-9) used the maxillary canines in genders identification; some depended on the mesio-distal width or the inter-canine width and the other combined both measurements to develop the canine index and standard canine index. in iraq, many studies were carried out as an aid in forensic odontology. al-nakib and alsaadi (10) estimated the chronological age of an iraqi sample by the application of kvaal’s technique on digital panoramic image and comparing between the real age and the estimated age. rashid and ali (11) used the linear measurements related to the mental and mandibular foramina vertical positions on digital panoramic images in genders determination. ali and al-nakib (12) evaluated the accuracy of digital cephalometric system in genders determination in iraqi samples with different age range using certain linear and angular craniofacial measurements. taha and al-nakib (13) differentiated between class i and class ii malrelationship using helical computed tomography. habeeb and fattah (14) estimated the chronological age among iraqi adult subjects based on various morphological variables of canine teeth using digital panoramic radiograph. these methods are x-ray dependant which is hazardous and not j bagh college dentistry vol. 25(4), december 2013 the role of maxillary canines pedodontics, orthodontics and preventive dentistry110 cheap. on the other hand, al-fahdawi (15) identified the genders of an iraqi sample from alanbar governorate using the mesio-distal crown diameter of the permanent teeth. he found that half of the teeth in the maxilla and more than half of the teeth in the mandible were significantly different with respect to genders, while nahidh (16) determined the gender of a sample of iraqi adults utilizing the mesio-distal width of maxillary central incisors and canines and determined the percentage of dimorphism as an aid in forensic dentistry. the aim of this study was to determine the gender of a sample of iraqi adults utilizing the mesio-distal width of maxillary canines, intercanine width and standard maxillary canine index, and to determine the percentage of dimorphism as an aid in forensic odontology. materials and methods sample the sample of this study consisted of 200 students with an age ranged between 17-23 years old (100 males and 100 females). those were selected from the students of the college of dentistry, university of baghdad and some secondary schools. they had full complement of permanent teeth with normal occlusion and no spacing, crowding, attrition, caries, dental fillings or periodontal problems in the anterior teeth. all of them had no history of orthodontic treatment, orthognathic or cranio-facial surgery. methods each subject was examined clinically to fulfill the inclusion criteria. then upper and lower impressions with alginate impression material were taken to construct the study models. the mesio-distal crown dimensions of the maxillary right and left canines were measured from the anatomical contact points (17) using digital sliding caliper gauge with the pointed beaks inserted in a plane parallel to the long axis of the tooth. the measurements were made to the nearest 0.01 mm. the inter-canine width or distance was measured from the canine tip to the canine tip on the other side with same caliper gauge (4-6). maxillary canine index (mci) was used for the first time for maxillary canines by sherfudhin et al. (4) when depended upon the method of rao et al. (18) who applied it on the mandibular canines. mci was calculated by dividing the mesio-distal width of the maxillary canine by the inter-canine distance (4,6). based on these values, the standard mci was derived as follows (4,6): standard mci = (mean males mci sd) + (mean females mci + sd) 2 statistical analyses all the data of the sample were subjected to a computerized analysis using spss program version 19. the statistical analyses included: • descriptive statistics: means, standard deviations, frequency, percentages and statistical tables. • inferential statistics: independent sample t-test to evaluate the genders difference. percentage of dimorphism which is the percentage by which the tooth size of males exceeds that of females {it equals to = [(xm/xf)-1x100] where xm is the mean tooth dimension of males and xf is the mean tooth dimension of females} (19). discriminant function statistics were used in gender identification in addition to the percentage of gender identification accuracy. in the statistical evaluation, the following levels of significance were used: p > 0.05 ns non-significant 0.05 ≥ p > 0.01 s significant p ≤ 0.01 hs highly significant results and discussion in this study, maxillary canines were chosen because hashim and murshid (20) found that the canines were the only teeth that exhibit dimorphism. subjects with age ranged from 17 to 23 years were selected since attrition is minimal in this age group and the eruption of canines and growth in width of both the jaws, including the width of the dental arches, are completed (21). sillman (22) stated that after 2 years of age, the inter-canine width continued to increase in the maxilla until 13 years of age, after this time, canine width remained stable. the results in table 1 indicated that the mesiodistal width of maxillary canines were higher in males than females with a highly significant difference; this comes in agreement with sherfudhin et al. (4), kalia (6), parekh et al. (8) and bakkannavar et al. (9), while al-rifaiy et al. (5) and boaz and guota (7) found non-significant genders difference. it is suggested that the way of influence of the y chromosome on the amelogenesis is regulatory, and that the difference in tooth size between males and females is explained by a differential growth-promoting effect of the y chromosome compared to the x chromosome. the general j bagh college dentistry vol. 25(4), december 2013 the role of maxillary canines pedodontics, orthodontics and preventive dentistry111 finding that tooth crown sizes in males exceeded, on average, those in females resulted from a greater thickness of dentin in male teeth. the difference is explained by the promoting effect of the y chromosome on dentin growth, probably through cell proliferation. it is conceivable that due to the y chromosome, mitotic potential is increased, which at different stages of development leads to the increase in cell division and may also account for other differences in the dentition (23,24). other cause for the difference in tooth size between males and females is the greater thickness of enamel in males due to the long period of amelogenesis compared to females (25). the mean value of inter-canine width was higher in males than females with a highly significant difference (table 1). this agrees with sherfudhin et al. (4), al-rifaiy et al. (5) and parekh et al. (8). kalia (6) found non-significant genders difference. the differences between the results of the present study and other studies may be attributable to the sample size, different ethnic groups or the accuracy of the instruments used in the tooth and inter-canine width measurement. the maxillary canine index was nearly similar in both genders depending on the mean canine width as there was no significant side difference in both genders. kalia (6) found highly significant genders difference with higher mean in males. the percentage of dimorphism was 6.13% for the mean canines’ widths, 4.66% for the intercanine width and 1.38% for the maxillary canine index (table 1). this finding is nearly equal to that of gran et al. (26) which was 5.9% and greater than bakkannavar et al. (9) which were 3.31% for right canine and 3.29% for left canine but less than parekh et al. (8) which were above 7% for the canines and 5.15% for the inter-canine width. table 1. descriptive statistics, genders’ differences and percentage of dimorphism for the measured variables (mm.) variables genders descriptive statistics genders difference percentage of dimorphism mean s.d. t-test p-value right canine (rc) males 7.99 0.43 7.683 0.000 (hs) 6.11 females 7.53 0.44 left canine (lc) males 7.94 0.49 6.938 0.000 (hs) 6.01 females 7.49 0.40 mean of both canines males 7.97 0.44 7.690 0.000 (hs) 6.13 females 7.51 0.39 inter-canine width (icw) males 36.38 2.84 4.501 0.000 (hs) 4.66 females 34.76 2.21 maxillary canine index (mci) males 0.220 0.02 1.433 0.150 (ns) 1.38 females 0.217 0.01 the frequencies and percentages of correctly classified and misclassified cases using the standard maxillary canine index were presented in table 2. the value of this index was 0.22 which was nearly equal to that of kalia (6). value of maxillary canine index above 0.22 was classified as male and equal to and less than 0.22 was classified as female. in this study, the percentages of gender identification accuracy using standard maxillary canine index were 44% for males, 74% for females and 59% for the combined sample. kalia (6) found them 77.38 % in males, 74.21 % in females and 75.79 % in combined sample which were higher than the present study. this may be attributed to the larger sample size utilized in kalia’s (6) study which was (252 males and 252 females). table 2. frequencies and percentages of correctly and misclassified cases using standard maxillary canine index genders frequencies and percentages of correctly classified cases frequencies and percentages of misclassified cases males 44 (44%) 56 (56%) females 74 (74%) 26 (26%) total 118 (59%) 82 (41%) j bagh college dentistry vol. 25(4), december 2013 the role of maxillary canines pedodontics, orthodontics and preventive dentistry112 discriminant analysis involves the determination of a linear equation like regression that will predict which group the case belongs to. the aim of the statistical analysis in discriminate analysis is to combine (weight) the variable scores in some way so that a single new composite variable, the discriminant score, is produced. discriminant analysis creates an equation which will minimize the possibility of misclassifying cases into their respective groups or categories. the form of the equation or function is: d = a + b1x1 + b2x2 +…+ bnxn d is predicted score (discriminant score: this is a weighted linear combination (sum) of the discriminating variables.) a is constant x is predictor and b is discriminant coefficient. in this study, the formula was: d= -29.512 + 0.930 (rc) – 0.014 (lc) + 0.380 (icw) + 40.643 (mci). where: rc= right canine lc= left canine icw= inter-canine width mci= maxillary canine index a further way of interpreting discriminant analysis results is to describe each group in terms of its profile, using the group means of the predictor variables. these group means are called centroids. in this study, males had a mean of 0.595 while females produce a mean of –0.595. the cut-off point for discrimination between the gender is ½ (0.595 + (-0.595)) = 0. if the calculated discriminant score is less than zero the case is classified as “female” and if the score is greater than or equal zero, the case is classified as “male” the frequencies and percentages of correctly classified and misclassified cases were shown in table 3. the percentage of correctly classified male cases was 70% and of females was 76% while of the total sample it was 73%. these percentages were higher than that of al-rifaiy et al. (5) which were 66.67% for males, 64.29% for females and 65.48% for the total sample although the standard mci was not used in that study. on the other hand, the percentages of accuracy in the present study were less than that of sherfudhin et al. (4) which were 88% for males, 86.8% for females and 87.38% for the total sample. this difference may be attributed to the larger sample size of sherfudhin et al. (4) which was 150 males and 151 females in addition to the difference in the mesio-distal width of the maxillary canines, i.e. 8.2 mm. for males and 6.7 mm. for females in comparison with the present study. table 3. frequencies and percentages of correctly and misclassified cases using discriminate analysis genders frequencies and percentages of correctly classified cases frequencies and percentages of misclassified cases males 70 (70%) 30 (30%) females 76 (76%) 24 (24%) total 146 (73%) 54 (27%) in conclusion; this is the third study that takes the standard maxillary canine index in gender determination after sherfudhin et al. 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(ivsl). 20. hashim ma, murshid za. mesiodistal tooth width: a comparison between saudi males and females, part 1. egypt dent j 1993; 39(1): 343-6. 21. proffit wr, fields hw jr, sarver dm, ackerman jl. contemporary orthodontics. 5th ed. st. louis: elsevier mosby; 2013. 22. sillman jh. dimensional changes of the dental arches: longitudinal study from birth to 25 years. am j orthod 1964; 50(11): 824-42. 23. alvesalo l, tammisalo e, hakola p. enamel thickness in 47, xyy males’ permanent teeth. ann hum biol 1985; 12(5): 421-7. 24. alvesalo l, tammisalo e, therman e. 47 xxx females, sex chromosomes and tooth crown structure. hum genet 1987; 77(4): 345-8. 25. moss ml, moss-salentijn l. analysis of developmental processes possibly related to human dental sexual dimorphism in permanent and deciduous canines. am j phys anthropol 1977; 46(3): 407-13. 26. garn sm, lewis ab, swindler dr, kerewsky rs. genetic control of sexual dimorphism in tooth size. j dent res 1967; 46(5): 963-72. alaa final.doc j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 50 assessment of mandibular radiomorphometric indices as predictors of osteoporosis in postmenopausal women (cephalometric reconstructed computed tomographical study) alaa s. mahdi, b.d.s. (1) lamia al-nakib, b.d.s., m.sc. (2) abstract background: osteoporosis affects almost all of the bones in the female body; the most important one in the facial bone is mandible. menopause is defined as an absence of the menses for one year. during this time, estrongen, progesterone and ovarian androgens production are diminished due to adult onset ovarian failure which leads to osteoporosis. this study aimed to evaluate the use of computed tomography mandibular morphometric indices for the assessment of pre and postmenopausal osteoporotic women. subjects and material: this study conducted on 50 iraqi females divided into 2 groups 20 -30years old as a control group and over50 years old as a study group attending al-karkh hospital, department of computed tomography.(each group25 female). information from each female was recorded and mentioned on a case sheet specially prepared. data collected, when analysed, using spss version 13 program loaded on a computer machine. results: all the measurements in this study( gonial angle in degree, antigonial angle in degree and depth in millimetre, mandibular and mental thickness in millimetre, bone mineral density in hu and mandibular cortex index),there were no statically significant differences between right and left side p-value <0.001. gonial angle had statistically positive linear correlation with age in the study group p-value <0.001. bone mineral density and mandibular and mental thickness had statically negative linear correlation with age. antigonial angle increased as age increased till reach 180 degree in some cases and the depth decreased correlated to the age till reach zero mm in some cases p-value <0.001. mandibular cortex index increased in bone irregularity related to increase in age. conclusion: it was concluded that osteoporosis and osteoporosis risk in postmenopausal females could be detected by using ct scan through measuring certain mandibular radiomorphometric indices. (j bagh coll dentistry 2014; 26(2): 50-57). الخالصة .من ضمن العظام عظام الوجھ والفكین خاصة عظمة الفك االسفل , تنخر العظام یؤثر على كل عظام االنثى ما بعد انقطاع الطمث , عدم انتظام الصفیحات العظمیھ التي تؤدي الى خشونة العظم وعدم انتظامھ في االشعھ, ترقرق الطبقھ السفلى الذقنیھوالخدیھ , رات تشمل اضمحالل العظم یتأثر ھذا العظم وضمن متغی .باعا درجھ تقریبا ومسافة اسفل الذقن تتغیر ت 180زیادة زاویة اسفل الذقن لتصل الى , تغیر زاویة عظمة الفك االسفل وزیادة درجتھا .سنھ النموذج البحثي 50سنھ والنموذج القیااسي فوق ال ) 30_20(امرأه عراقیھ وقسمت الى قسمین 50تمت ھذه الدراسھ على .والسریریھ من المریضھ وسجلت في ورقة تشخیص خاصھ خصصت لكل مریض قصدوا مستشفى الكرخ التعلیمي قسم االشعھوالمفراس الحلزوني اخذت المعلومات الطبیھ 13النسخھspss)(سوم بیانیھ باستعمال برنامج ربجمعت النتائج وحللت احصائیا بانھ ) وكثافة العظم والمقیاس السمكي الخدي, والخدیھ سمك العظم في المنطقة الذقنیھ,العمق الخدي , الزاویة الخدیھ , زاویة الفك االسفل(اوضحت النتائج لكل المتغیرات التي جمعت .لكل مریض لزاویة الفك االسفل تغیر بصورة طردیھ وعالقة موجبھ مع العمرلكل مریض) الیمنى والیسرى(الجھتین الیوجد اختالف بین .الذقني یتغیر بصوره عكسیھ وسالبھ مع زیادة العمر كثافة العظم والسمك الخدي .درجھ 180الخدیھ ل تقریبا مستوى الصفر في بعض الحاالت التي یصل فیھا الزاویھ درجھ في بعض الحالت اما العمق فیصل 180الخدیھ تتغیر بزیادة العمر لتصل تقریبا الزاویھ .بزیادة العمر الصنف الثاني والصنف الثالث) للعظم( المقیاس السمكي الخدي یزداد عدم انتظامھ لعمر ویمكن ان یشخص عن طریق مقایس معینة في الفك االسفل بسھولھ باستعمال اخیرا نتوصل بان ھشاشة العظام وخطر االصابھ بھا عند االناث ما بعد انقطاع الطمث یزداد بزیادة ا .المفراس الحلزوني introduction osteoporosis affects all bones, including those of the facial skeleton. to date the facial bones have not drawn much attention due to the minimal probability of morbid fractures (1). there is scientific evidence that the decrease in bone mass due to osteoporosis also affect the mandible. because of high costs and limited availability of dxa equipment it is worthwhile to look for alternative diagnostic techniques for osteoporosis (2,3). (1) m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. not everyone will get osteopenia or osteoporosis. however there are certain risk factors that can increase the likelihood that a person will have moderate to severe loss of bone mass, including the following (1, 2): • gender: women are a higher risk because they have less bone mass than men. women also often experience a loss of bone mass after menopause. • race: asian and caucasian women, especially those who are small-boned, are at highest risk. • family history: patients with a family history of low bone mass have a 50%-85% increased risk of developing osteoporosis. j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 51 • age: most people (men and women) lose about .5% of bone mass every year after the age of 50. • lifestyle choices: a poor diet with a lack of calcium and vitamin d, smoking, excessive use of alcohol or caffeine, and lack of exercise contribute to a loss of bone mass. • other medical conditions: hyperthyroidism, hyperparathyroidism, and cushing's syndrome, can contribute to bone loss. certain medications (such as prednisone or phenytoin) are known to cause bone loss as well (1). considering that odontological patients are frequently referred for being submitted to panoramic radiography a widely available, lowcost method capable of demonstrating agingrelated morphological alterations of the mandible, several indices, techniques for analysis and images processing have been researched in order to evaluate the applicability of this type of radiography for detecting bone mass loss. however, the results of these studies have been contradictory (4-6) in 2010 huumonen, et al (5) found that the indices evaluated were reproducible; panoramic mandibular and mental indices presented the highest sensitivity in the detection of osteopenia/osteoporosis, however the panoramic mandibular index specificity was low. although all the indices evaluated could identify low bone density, only the panoramic mandibular and mental indices could differentiate patients affected by osteopenia/osteoporosis. in the present study, normal reference measurements were used as the standard for the assessment of possible means of early detection of osteoporosis by radiographic examination, which is simple, and affordable by patients and methods the sample included fifty (50) iraqi female patients attending al-karkh hospital department of ct for different purposes from 6 dec. 2012 till 1 jul. 2013. the sample divided into two groups according to their age as following: 1st group: 25 subject with 20-30y as control group 2nd group: 25 subject with more than 50 ys as study group exclusion criteria 1-metabolic bone disease 2-cancer with bone metastasis 3-diabetes 4-major renal impairment 5-medication that affected bone metabolism other than estrogen 6-smoker mandibular cortical thickness from ct viewer icons get sagittal view and scrolling the mouse to get the point that intersection of inferior border of mandible with line pass through the anterior border of the mandible. the thickness of the mandibular cortex was measured on the line perpendicular to the inferior border of the mandibular cortex at the intersection with the tangent line. the measurement was done for both sides. mental cortex thickness from the icons ct viewer sagittal view could be obtained the reading taken in slices passing through mental foramen the thickness of the cortex at mental area will be measured on the line perpendicular to the parallel lines drown in upper and lower borders of inferior border of the mandible at the middle of the mental foramen (full cortex thickness) scrolling the mouse to get opposite side and same technique was repeated to measure the mental cortex thickness of other side. figure 1: mental cortical thickness gonial angle from sagittal view this angle readied by drown two lines the 1st with the inferior border of the mandible the 2nd from the outer border of the ramus. j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 52 figure 2: gonial angle antigonial depth and angle from sagittal view : a. two lines parallel to the antigonial region that interseted at the deepest point of the antigonial notch. b. antigonial depth was measured as the distance along perpendicular line from the deepest point of the notch concavity to a tangent through the inferior border of the mandible. bone minerial density value bmd were recorded in the mental and gonial areas at full thickness of the cortical bone in hounsfield unit figure 3: bone density in mental area in hu mandibular cortex index klemettis classification for osteoporosis: class i: smooth & even endosteal margin in inferior cortex on one or both sides class ii: semilunar defect on one or both sides class iii: heavy resorptive or porosity sign on one or both sides this result obtained by change the windowing contrast from modified to bony shadow to see any defect in cortical bone that may appear in one or both sides. results assessment of menopausal effect the mean of gonial angle was significantly higher among post-menopausal cases (121.9) degree comparing with control (114.4) degree in (table.1) menopausal on average increases gonial angle by mean of 7.5 degree than antigonial angle that was 3 degrees which indicated for moderate strong effect more than antigonial angle about twice time in revealing the menopausal effect (cohen’s d=0.55). the result was obviously but the differences failed to reach the level of statistically significance. mandibular cortex index (mci) the median mci was significantly higher percentage among post-menopausal cases (class ii) was 44%compare to control sample as shown in (table 2) the linear correlation between outcome measurements among cases only according to the table 3, one can determine the relation between the variables strong weak or moderate 0-0.2 =very weak 0.21-0.4=weak 0.41-0.7=moderate strong 0.71-0.9=strong 0.91-1=very strong the bone mineral density in gonial area had statistically significant strong positive (direct) linear correlation with bone density in mental area. r=728 (p<0.001) from table (3) mandibular and mental cortex thickness had moderate strong positive linear correlation r=0.6 p<0.001 gonial and antigonial angle had statistically non significant very weak correlation r=0.269 p=0.06ns j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 53 figure 4: relation between bone mineral density-gonia and mental area association between mci and other variable among cases the mean gonial angle was lowest in class i mci (117 degree) increasing to 122.1 degree in class ii mci cases to reach its highest mean 126.5 degree among class iii mci cases. (table 4) r=0.516 p<0.001 the difference among mean in goinal angle were statistically significant and moderate strong positive linear correlation between ga and mci. from table5 the relation between mci and bone mineral density in both mental and gonial area the mean decreased with class increased (1729.1 to 1426.2 to 947.1) that were mental area while in gonial (1511.1 to 1421.6 to 930.4) so there was moderate strong correlation between bone density and mci effect of age on outcome measurement among cases after classifying the study group into three groups with ten class interval 50-59and 60-69 and 70-73. gonial angle and antigonial angle and depth: the mean of gonial angle increase with ages increased 117.2 to 124.7 to 131.5 there was strong correlation between gonial angle and increasing age, gonial angle had a statistically significant strong linear correlation with age p<0.001 as shown in (table 6). mental and mandibular thickness the mean of mental thickness was decreased with age increased from 3.7mm in 1st age class to 3.1mm in the second class, to 2.1mm in 3rd age class and strong correlation r=0.71 p<0.001 as shown in (table 7). the mandibular thickness also decreased with aged class from2.4mm to 2.1mm to 1.6mm the mandibular thickness had weak correlation with age r=0.43 p<0.001. so the mental thickness had stronger correlation with age than mandibular thickness depending on r value. mandibular cortex index: the median in 1stclass (50-59y) was class i. in the 2nd class (60-69y) was class ii, while in the 3rd class (70-73y) was class iii. that indication for increasing bone change with age and strong correlation r=0.672 p<0.001in (table 8) table1: difference between cases and control group for gonial angle and antigonial angle size and depth variables controls (young adult females) cases (post-menopausal age female) p mean difference cohen's d gonial angle 0.007 7.5 0.55 range (112 140) (110 136) mean 114.4 121.9 sd 17.89 7.23 se 2.53 1.02 n 50 50 anti-gonial angle size 0.09[ns] 3.0 0.34 range (153 180) (152 180) mean 169.9 172.9 sd 9.92 7.51 se 1.4 1.06 n 50 50 anti-gonial depth 0.26[ns] -0.1 -0.22 range (0 1.2) (0 1.2) mean 0.6 0.5 sd 0.46 0.43 se 0.07 0.06 n 50 50 j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 54 table 2: mandibular cortex index (mci) in control group and cases study group controls (young adult females) cases (post-menopausal age female) mandibular cortical index n % n % class-1 50 100.0 14 28.0 class-2 0 0.0 22 44.0 class-3 0 0.0 14 28.0 total 50 100.0 50 100.0 p (mann-whitney) < 0.001 table 3: relation between variables in cases (postmenopausal) only. gonial angle anti-gonial angle anti-gonial depth bone mineral densitymental bone mineral densitygonia mental cortical thickness anti-gonial angle r=0.269 p=0.06[ns] anti-gonial depth r=-0.164 p=0.26[ns] r=-0.872 p<0.001 bone mineral density-mental r=-0.642 p<0.001 r=-0.303 p=0.033 r=0.165 p=0.25[ns] bone mineral density-gonia r=-0.537 p<0.001 r=-0.287 p=0.043 r=0.308 p=0.03 r=0.728 p<0.001 mental cortical thickness r=-0.519 p<0.001 r=-0.039 p=0.79[ns] r=-0.058 p=0.69[ns] r=0.692 p<0.001 r=0.486 p<0.001 mandibular cortical thickness r=-0.368 p=0.008 r=-0.403 p=0.004 r=0.403 p=0.004 r=0.523 p<0.001 r=0.476 p<0.001 r=0.626 p<0.001 table 4: relation of mci in postmenopausal to gonial angle and antigonial angle and depth. variables mandibular cortical index class i class ii class iii p gonial angle 0.001 range (110 126) (110 130) (114 136) mean 117 122.1 126.5 sd 4.84 7.33 6.2 se 1.29 1.56 1.66 n 14 22 14 r=0.516 p<0.001 anti-gonial angle 0.01 range (160 180) (152 180) (163 180) mean 174.7 169.5 176.5 sd 7.96 7.2 5.26 se 2.13 1.54 1.41 n 14 22 14 r=0.043 p=0.77[ns] anti-gonial depth 0.014 range (0 1.2) (0 1.2) (0 0.8) mean 0.3 0.7 0.4 sd 0.52 0.35 0.35 se 0.14 0.07 0.09 n 14 22 14 r=0.018 p=0.9[ns] j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 55 table 5: relation between mci and bone mineral density in postmenopausal females in mental and gonial area cases (post-menopausal age female) variables mandibular cortical index class-1 class-2 class-3 p bone mineral density-mental <0.001 range (1320 1986) (1024 1860) (509 1699) mean 1729.1 1426.2 947.1 sd 224.91 289.7 356.36 se 60.11 61.76 95.24 n 14 22 14 r=-0.758 p<0.001 bone mineral density-gonial area <0.001 range (1005 1946) (1054 1880) (505 1786) mean 1511.1 1421.6 930.4 sd 363.23 288.35 390.91 se 97.08 61.48 104.47 n 14 22 14 r=-0.544 p<0.001 table 6: relation of age with gonial angle, antigonial angle and depth. variables age (years) 50-59 60-69 70-73 p gonial angle-right <0.001 range (110 127) (110 130) (128 136) mean 117.2 124.7 131.5 sd 5.42 5.65 2.66 se 1.11 1.26 1.09 n 24 20 6 r=0.747 p<0.001 anti-gonial angle 0.03 range (160 180) (152 180) (176 180) mean 173.8 170.1 178.7 sd 7.36 7.67 1.63 se 1.5 1.72 0.67 n 24 20 6 r=0.035 p=0.81[ns] anti-gonial depth 0.017 range (0 1.2) (0 1.2) (0 0.6) mean 0.4 0.7 0.3 sd 0.49 0.31 0.29 se 0.1 0.07 0.12 n 24 20 6 r=0.105 p=0.47[ns] j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 56 table 7: relation between age and mandibular and mental thickness in postmenopausal female variables age (years) 50-59 60-69 70-73 p mental cortical thickness (mm) <0.001 range (3 4.3) (2 3.9) (1.9 2.2) mean 3.7 3.1 2.1 sd 0.36 0.51 0.1 se 0.07 0.11 0.04 n 24 20 6 r=-0.71 p<0.001 mandibular cortical thickness (mm) <0.001 range (1.8 3.5) (1.8 2.6) (1.5 1.9) mean 2.4 2.1 1.6 sd 0.46 0.22 0.16 se 0.09 0.05 0.07 n 24 20 6 r=-0.435 p=0.002 table 8: relation between age and mci in post menaposaul female variables age (years) 50-59 60-69 70-73 mandibular cortical index n % n % n % class i 14 58.3 0 0.0 0 0.0 class ii 8 33.3 14 70.0 0 0.0 class iii 2 8.3 6 30.0 6 100.0 total 24 100.0 20 100.0 6 100.0 p (kruskal-wallis) <0.001, r=0.672 p<0.001. discussion in this study the mandibular and mental cortex thickness was significantly lower among postmenopause when compared to premenopause study group and there was a statically highly significant inverse relation between menopausal and the mandibular and mental thickness with (p value <0.001) and this result indicate that the elderly age groups (postmenopausal has significantly lower thicknesses when compared to the younger age group(premenopausal)which emphasized the fact that it was an age related phenomena this finding is in agreement that found by others (12,13). as the human increased in age this angle will increased so the notch disappeared till reached near 180 degree due to many factors depended either male or female (14). in post menapousal female in this study this angle will reached large divergent level of angle to reached 180 degree that mean no notch or angle that agree with shahabi et al. (15). morphology of the mandible changes with age consequence of tooth loss which can be expressed as widening of the gonial angle shorting of the ramus and condylar height (16). taguchi et al (17) found that multiple linear regression showed that the bmd was significantly decreased with age (16,17) which is similar to the present study. the association between the mandibular cortical thickness and bone mineral density was statistically significant even after adjustment for hormonal treatment, smoking, age at menopause, and body mass index (p = 0.04). in 2001, shepherd (16) stated that bone loss is a closely age related phenomenon. radio morphological change in the mandible either in cortical or trabecular bone is inversely correlation with age that agrees with our study and the result (18). von wowern (19) stated that human bones decrease in density and increase in porosity beginning at about decade of life after the age of 40, the bmd of the skeleton decreases, so that by the age of 65, about one third of the bone minerals has been lost. decreased physical activity, lower secretion of estrogen, diet, race, and heredity may all play a role in age-related bone loss. references 1. ardakani fe, naifar n. evaluation of changes in the mandibular angular cortex using panoramic imaging. j contemp dent pract 2004; 5(3): 1-15. 2. abhyankar s. long-term effect of cigarette smoking smoking in women. am j obstetrics and gynecology 2010; 162: 502-14. 3. dutra v, devlin h, susin c, yang j, horner k, fernandes ar. mandibular morphological changes in low bone mass edentulous females: evaluation of j bagh college dentistry vol. 26(2), june 2014 assessment of mandibular oral diagnosis 57 panoramic radiographs. oral med oral pathol oral radiol endod 2011; 102(5): 663-8 4. genant hk, jergas m, palermo l, et al. comparison of semiquantitave visual and quantitive morphometric assessment of prevalent and incident vertebral fractures in osteoporosis. j bone miner res 1998; 11: 984-96. 5. huumonen s, sipila k, haikola b, tapio m, soderholm al, remes-lyly t, oikarinen k, raustia a.m :influence of edentulousness on gonial angle, ramus and condylar height. j oral rehabil 2010; 37: 34-8. 6. klemetti e, vainio p, lassila v et al. cortical bone mineral density in the mandible and osteoporosis status in postmenopausal women. scand j dent res 2009; 101(4): 219-23. 7. thrasivoulos k, tzello g. the facial skeleton in patient with osteoporosis; field of sign and treatment complications. j osteoporosis 2011; article id 147689. 8. miliiuniene e, alekna v, peciuliene v, tamulaitiene m, maneliene r. relationship between mandibular cortical bone height and bone mineral density of lumbar spine. stomatologija, baltic dental and maxillofacial j 2008; 10: 72-5. 9. national institutes of health: osteoporosis prevention, diagnosis and therapy: nih consensus statement. online 2000 march 27-29. 10. oda h, matsuzaki el, tokuhashi y, wakabayashi k, uematsu, iwahashi m. degeneration of intervertebral discs due to smoking: experimental assessment in a rat-smoking model. j orthopedic sci 2004; 9: 135-41. 11. polat p, ceylan g, suma s, yanikogln n. the effect of tooth extraction on cortical thickness and bone mineral density of the mandible: evaluation with computerized tomography. turk j med sci 2001; 31: 271-4. 12. reddy s, karthikeyan r, sherlin hj. oral signs and salivary parameters as indicators of possible osteoporosis and osteopenia in postmenopausal women. a study of 45 subjects. braz j oral sci 2008; 7(24):1502-6. 13. richard dj, subramaniam m, spelsberg tc. molecular and cellular mechanisms of estrogen action on the skeleton. j cell biochem 1999; suppl 32-33: 123-32. 14. santini a, land m. a comparison of the position of the mental foramen in chinese and british mandibles. j acta anat 1990; 137(3): 208-12. 15. shahabi m, ramazanzadeh ba, mokhber n. comparison between the external gonial angle in panoramic radiograph and lateral cephalograms of adult patients with class i malocclusion. j oral sci 2009; 51:425-9. 16. shepherd je. effects of estrogen on cognition, mood and degenerative brain diseases, j am pharm asso mar-apr2001; 41(2): 221-8. 17. taguchi a, sanada m, krall e, et al. relationship between dental panoramic radiograph finings and biochemical markers of bone turnover. j bone miner res 2003; 18: 1689-94. 18. uthman at. radiomorphometric indices of the mandible in 40-60 years old adults. iraqi dental j 2003; 33: 258-71. 19. von wowern n. microradiographic and histomorphometric indices of mandibles for diagnosis of osteopenia. scand j dent res 1982; 90(1): 47-63. dara f.doc j bagh college dentistry vol. 25(3), september 2013 evaluation of propolis restorative dentistry 8 evaluation of propolis from kurdistan region as a new resinous sealer in root canal obturation-part i biocompatibility study dara hama, b.d.s., m.sc., ph.d. (1) hussain al-huwaizi, b.d.s., m.sc., ph.d. (2) salim el-samarri, b.d.s., ph.d. (3) abstract background: many materials were proposed as root canal obturating materials but the biocompatibility issue remains to be a critical one. propolis has been used as a therapeutic agent since the time of hippocrates. it is known that propolis exhibits some pharmacological activities, such as antibacterial, antiviral, antifungal and anti inflammatory activity. materials and methods: eighteen albino rats were used in the study and divided randomly into three groups of 6 animals for each group. each group was scheduled to be sacrificed at different time periods, which were three days, one week and three weeks. propolis and zoe sealer implants of 4mm in diameter and 0.5 gm in weight were implanted in the dorsal side of the rats. at the end of the implantation, the rats were scarified and the histopathological picture was made to the implantation site. results: zinc oxide eugenol sealer showed severe inflammation after 3 days of implantation whci subsided after 7 days. after 21 days, moderate inflammatory reaction was evident. propolis presented moderate reaction after 3 and 7 days but with presence of signs of collagen fiber formation. after 21 days, connective tissue capsule was present. conclusion: propolis presented better biocompatibility than zinc oxide eugenol sealer. key words: propolis, biocompatibility. (j bagh coll dentistry 2013; 25(3):8-13). introduction root canal treatment aims to eliminate infection of the root canal and to completely fill the canal space in order to prevent apical and coronal penetration of liquids and microorganisms. various methods have been proposed for root canal filling. the most frequently used methods use semisolid materials such as gutta-percha in combination with a root canal sealer or paste (1). biological compatibility of root canal sealers is of importance as these materials come into contact with periapical tissues including fibroblasts. the tissue response to these materials may influence the final outcome of root canal treatment (2). several different methods have been described for assessing tissue toxicity. one of them evaluates the biocompatibility of endodontic sealers in subcutaneous tissue of rats using by implantation of polyethylene tubes filled with the material to be tested. this method is simple and easy to be reproduced and standardized (3, 4). propolis, or 'bee glue', is a complex resinous mixture of plant-derived products gathered, modified and used by bees as a general purpose sealer, draught excluder and antibiotic in their hives. (1) lecturer, college of dentistry, hawler medical university. (2) professor, college of dentistry, university of baghdad. (3) retired propolis typically consists of waxes, resins, water, inorganics, phenolics and essential oils (5). propolis has been used as a therapeutic agent by the world population since the time of hippocrates. it is known that the ethanol extract of propolis (eep) exhibits some pharmacological activities, such as antibacterial, antiviral, antifungal, anti inflammatory, anesthetic and cytostatic properties (6,7). few studies have been conducted, mainly on animals and to a lesser extent on humans, to investigate the use of propolis in different dental fields (8-10). the aim of this study was to estimate biocompatibility of ethanolic extract of propolis collected from iraqi kurdistan region to be used as endodontic sealer. materials and methods in this study 18 male, six week old albino rats were used to evaluate subcutaneous biocompatibility of propolis as endodontic sealer compared with commercially available zoe sealer. their weights ranged from 150-200 grams. they were kept in the animal house of college of medicine / hawler medical university. the room temperature was maintained at 25oc. a 12 hr light/dark cycle was set. rodent food rich in nutrient and tap water were used as bedding. the animals were divided randomly into three groups of 6 animals for each group. each group was scheduled to be sacrificed at different time j bagh college dentistry vol. 25(3), september 2013 evaluation of propolis restorative dentistry 9 periods, which were three days, one week and three weeks. anesthesia and surgical procedure the surgical procedure was done under general anesthetic drug by intraperitoneal injection of 50mg/kg (b.w.) ketamine hydrochloride. autoclave was used to sterilize all instruments with a pressure of 15 lb/sq in above atmospheric pressure to obtain a temperature of 121°c for 15 minutes. the dorsal skin was shaved, disinfected with 5% tincture of iodine, and small incisions, approximately 15 mm long, were made with a number ten blade, in both sides of the dorsum. two separate pockets were created by blunt dissection to implant the test materials in subcutaneous tissue to a depth of 15 mm to avoid interference of suture and the healing process of the skin wound. propolis and zoe sealer implants 4mm in diameter and 0.5 gm in weight were prepared and sterilized by ultraviolet radiation (over night). the propolis was implanted in the left pocket while the zoe sealer was implanted in right pocket of each rat (figure 1). figure 1: implantation of the test material. after implantation, margins of the wound were joined and closed with interrupted suture (4-0 black silk sutures) distant from the material for a perfect cooptation. after suturing, asepsis was performed again. post-operatively, the animal was kept under observation till recovery from anesthesia. later on, no re-operations were required and no wound dehiscence occurred. sutures on the dorsal surface of the third group which were to be scarified after three weeks were lifted after seven days. 2. termination at the end of the experimental periods (3, 7 and 21 days), the animals were sacrificed by anesthetic overdose (chloroform) in glass jar. the skin overlaying the implants was shaved and a standard quadrangular incision was performed 10 mm away from the suture line and down to the subcutaneous tissue. then, an incision was made parallel to the skin surface. the implants with surrounding tissue were removed from the rats, immersed in 10 % formalin solution and fixed for 24 hours (figure 2). figure 2: fixation of the implants in 10% formalin. 3. histotechnical procedures after fixation, the tissues were processed by paraffin embedding and then longitudinally sectioned through the implants. serial sections approximately 5µm thick were obtained from each specimen. the specimens were placed on microscopic slides. after proper attachment, the paraffin was removed by means of xylene and the sections were dehydrated with decreasing concentrations of ethanol and deionized water. finally the sections were stained with hematoxylin and eosin (figure 3). figure 3: the prepared slides of the implanted tissues. the histological sections were analyzed at different magnifications (40x and 400x) under a digital biological microscope, noting tissue reactions on the sealer–connective tissue interface. all specimens underwent blinded examination by a single examiner who did not know which sealer or which period was being examined. the criteria of inflammation were estimated by counting the number of inflammatory cells using eye piece graticule. inflammatory cells were counted in thirteen squares on the grid in an n letter pattern (figure 4). the severity of j bagh college dentistry vol. 25(3), september 2013 evaluation of propolis restorative dentistry 10 inflammation was scored into the following grades according to the highest number which may be counted into the following grades: • no inflammation 0-20 (normally found inflammatory cells). • mild 21-111 (increasing by 90). • moderate 112-202 • sever 203-292 * * * * * * * * * * * * * figure 4: eye piece graticule. results results of zinc oxide eugenol sealer implantation three days after implantation, panoramic view of the experimental area shows a hole that represents the exact position of the tested material which has been degraded during slide preparation. remnants of tested material can be seen on the periphery of the hole which is followed by region of sever tissue deformation, losing of normal architectures of the connective tissue and heavy infiltration of inflammatory cells (figure 5,6). the higher magnification shows sever inflammatory reaction (no. of 286 cells) with complete invasion of collagen fibers with inflammatory cells and many dilated blood vessels that contain rbc and inflammatory cells (figure 7). figure 5: panoramic view of three day zoe implantation hole representing the exact position of the tested material. (h&ex25) figure 6: three days zoe implant showing sever inflammatory cell infiltration and dilated blood vessels. (h&e x 40). figure 7: three days of zoe implanted with sever inflammatory cell infiltration and dilated blood vessels. (h&e x 100). seven days after implantation, although the hole created by the insertion of the test material was reduced but the area still shows sever inflammation with the heavy inflammatory cells, focus of necrosis and complete hylanization with complete loss of the tissue architectures (figure 8). the degree of inflammation gradually reduced as we move away from tested position; many dilated blood vessels are seen and the region filled with multinuclear macrophages. figure 8: seven days zoe implant showing the area still shows sever inflammation with the heavy inflammatory cells (h&e x 100). j bagh college dentistry vol. 25(3), september 2013 evaluation of propolis restorative dentistry 11 the hole created by the tested material was still present twenty one days following the implantation indicating the material still not resorbed. the inflammatory reaction became moderate (number of inflammatory cells 195). the periphery of the region shows highest intensity inflammatory reaction which diminishes as we move away together with high number of fibroblast and many newly formed collagen fibers. angioblast can also be seen with budding of new blood vessels that indicates the repair and healing process. (figure 9,10). figure 9: twenty one days after implanting zoe (h&e x 40). figure 10: twenty one days after implanting zoe showing moderate inflammatory reaction. (h&e x 100) results of propolis implantation the panoramic view of the area of material insertion shows some trace amount of inserted material which was encircled by fibrous capsule that isolated the tested material from the affected area which is infiltrated by inflammatory cells and shows many congested blood vessels (figure 11) increasing the power of magnification and by counting the number of inflammatory cells, the affected region exhibits moderate inflammatory reaction and the region mostly infiltrated by polymorphonucleocytes (pmnl) which also infiltrate the congested blood vessels in the region. although the inflammatory reaction is still present next to the capsule, the area shows some regions of normal architectures with presence of collagen fiber (figure 12 ). figure 11: three days propolis implant encircled with fibrous capsule. (h&e x 40). figure 12: three days propolis implant. ( h&e x 100). examining the section of seven day implant of propolis revealed that the fibrous capsule encircling the tested material becomes more obvious with many collagen fibers that arranged in radial direction and isolating the tested material from affected region. in spite of moderate inflammatory reaction still seen with the infiltration of many macrophages, many fibroblasts are seen together with lot of normal bundles of collagen fibers (figure 13, 14). histological findings after twenty one day implantation of propolis shows that connective tissue capsule is still present and seems to be consist of many thin layers of connective tissue. j bagh college dentistry vol. 25(3), september 2013 evaluation of propolis restorative dentistry 12 figure 13: seven days propolis implant more obvious fibrous capsule. (h&e x 40). figure 14: seven days propolis implant with moderate inflammatory reaction (h&e x 100). the region next to the capsule shows moderate inflammatory reaction although it’s obviously less than previous group. thicker normal collagen fiber can be seen in the region as a result of fibroblastic proliferation together with angioblastic proliferation that results in the budding of new blood vessels (figure 15). figure 15: twenty one days after implanting propolis showing budding of new blood vessels (h&e x 100). discussion results of this study revealed the three days control specimens (zinc oxide eugenol) with sever inflammatory reaction with complete invasion of collagen fibers with inflammatory cells and dilated blood vessels. on the other hand, the experimental specimens (propolis) revealed fibrous capsule that encircled and isolated the tested material with moderate inflammatory reaction mostly infiltration by polymorphonuceocytes (pmnc) with congested blood vessels. the area next to the capsule showed also some regions of normal architectures with presence of collagen fibers. the reaction observed to the three days specimens may be more likely due to the surgical trauma rather than caused by the materials’ toxicity. however, it allowed evaluating the behavior of the materials along the experimental time and during the natural skin healing process as the initial period. at this time, the tissue was disorganized and infiltrated with neutrophils, which is consistent with the findings of the study by gomes-filho et al (11). on the seventh day, the areas of zinc oxide eugenol implantation still showed sever inflammation although the hole created by the insertion of the tested material was reduced. but the degree of inflammation was gradually reduced moving away from the tested position with presence of many dilated blood vessels and multinuclear macrophages. when the propolis specimens scrutinize after seven days, the fibrous capsule was more obvious with moderate inflammatory reaction with infiltration of many macrophages and lot of fibroblasts. observing both specimens after three weeks revealed mild inflammatory reaction (number of inflammatory cells=195), although the periphery of the region implanted by zinc oxide eugenol showed higher intensity inflammatory reaction with high number of fibroblast and newly formed collagen fibers and new blood vessels away from periphery which indicates healing process. the connective tissue capsule around propolis was still present with moderate inflammatory reaction in the region next to it although it was obviously less than the previous group with fibroblast proliferation together with budding of new blood vessels showing phenomena of healing. results obtained from this study regarding zinc oxide eugenol coincide with gomes-filho et al (11); economides et al (12) and zafalon et al (13). the reasonable explanation for this result may be that tubliseal is a typical zinc oxide-eugenol sealer. its' irritative ability could be attributed primarily to eugenol and secondarily to the zinc j bagh college dentistry vol. 25(3), september 2013 evaluation of propolis restorative dentistry 13 ions that it contains. it should be noted that free eugenol is still present even after the sealer has been set and is available for release over an extended period. end results regarding propolis implantation comes in agreement with many studies as castaldo and capasso (14); farrĕ et al (15); orsi et al (16) and alnema et al (10) since these studies have the same opinion that the activity of propolis is dependant upon the chemical composition of propolis samples collected in different geographical areas as well as the method of extraction. some of these components may act synergistically. the exact mechanism underlying the positive effects of propolis and its components is not fully understood and requires further experimental studies (14, 17). according to the conditions of this study the propolis extract that was tested may be considered as biocompatible. references 1. khashaba rm, chutkan nb, borke jl. comparative study of biocompatibility of newly developed calcium phosphate-based root canal sealers on fibroblasts derived from primary human gingiva and a mouse l929 cell line. int endod j 2009; 42: 711–8. 2. waltimo tm, boiesen j, eriksen hm, ørstavik d. clinical performance of three endodontic sealers. j oral surg oral med oral pathol oral radiol & endod 2001; 92: 89–92. 3. olsson b, sliwkowski a, kaare l. subcutaneous implantation for the biological evaluation of endodontic materials. j endod 1981; 7:355-69. 4. orstavic kd, mijör ia. histopatoloy and x-ray microanalysis of the subcutaneous tissue response to endodontic sealers. j endod 1988;14:13-23. 5. bonvehi js, coll fv, jorda re. the composition, active components and bacteriostatic activity of propolis. j am oil chem soc 1984; 71: 529–32. 6. martins rs, pereira esj, senna mib, mesquita ra, santos vr. effect of commercial ethanol propolis extract on the in vitro growth of candida albicans collected from hiv seropositive and hiv-seronegative br patients with oral candidiasis. j oral sci 2002; 44: 41–48. 7. cicala c, morelle s, iorio c, capasso r, borelli c, mascolo. vascular effects of caffeic acid phenethyl ester (cape) on isolated rat thoracic aorta. life sci 2003; 73: 80–4. 8. ozan f, polat za, er k, ozan u, deg˘er o. effect of propolis on survival of periodontal ligament cells: new storage media for avulsed teeth. j endod 2007; 33: 570–3. 9. hayacibara mf, koo h, rosalen pl et al. in vitro and in vivo effects of isolated fractions of brazilian propolis on caries development. j ethnopharmacol 2005; 101: 110–15. 10. alnema m. an analytical and histological study of a new root canal filling material composed of iraqi propolis, bee wax and vanillin. phd thesis, college of dentistry, university of baghdad 2006. 11. gomes-filho j, gomes b, zala a, ferraz c, souzafilho f. evaluation of biocompatability of root canal sealers using subcutaneous implants. j appl oral sci 2007; 15(3):186-94. 12. economides n, kotsaki-kovatsi v, athanassios poulopoulos a,kolokuris i, georgios rozos g, shore r. experimental study of the biocompatibility of four root canal sealers and their influence on the zinc and calcium content of several tissues. j endod 1995; 12(3): 122-7. 13. zafalon e, versiani m, alves de souza c, moura c, dechichi p. in vivo comparison of the biocompatibility of two root canal sealers implanted into the subcutaneous connective tissue of rats. oral surg oral med oral pathol oral radiol endod 2007; 103:e88-e94. 14. castaldo s, capasso f. propolis, an old remedy used in modern medicine. fitoterapia 2002; 73 (l): s1–s6. 15. farrĕ r, frasquet i, sánchez a. propolis and human health. ars pharmaceutica 2004; 45(1):21-43. 16. orsi ro, sforcin jm, funari s, bankova v. effects of brazilian and bulgarian propolis on bactericidal activity of macrophages against salmonella tryphimurium. int immunppharmacol 2005; 5: 35968. 17. de almeda ec, menezes h. anti inflammatory activity of propolis extracts. review. j venom anim toxins 2002; 8(2): 100-17. hind.doc j bagh college dentistry vol. 27(2), june 2015 load-deflection pedodontics, orthodontics and preventive dentistry154 load-deflection characteristics and force levels of coated nickel titanium orthodontic archwires hind dawood abaas, b.d.s. (1) akram faisal al-huwaizi, b.d.s., m.sc., ph.d. (2) abstract background: coated archwires have been introduced to improve esthetics during orthodontic treatment. theaim of the present study was to evaluate and compare the load–deflection characteristics and force levels of six brands of coated nickel titanium orthodontic archwires using palatal and gingival deflection. materials and methods: ten round wires (0.016 inch) and ten rectangular wires (0.019x0.025 inch) were obtained from each of six brands (g&h, opal, ortho technology, dany, hubit and astar companies). the load-deflection properties of these archwires were evaluated by the modified bending test usinga readymade dental arch model in both palatal and gingival directions at 37°c temperature using a universal material testing machine. forces generated at maximum loading of 2mm and at unloading of 1.5mm were measured. results: all the wires showed hysteresis and significant differences in their load deflection curves, but these differences were more evident in round wires than in rectangular wires where g&h wires showed the widest loading unloading deflection curves. the maximum loading force of round wires in gingival deflection were higher than by palatal deflection. the force decline during unloading (plateau gap) ranged between 18 to 34% for round wires and 17 to 37% for rectangular wires. conclusion: coated epoxy wires (g&h, opal, astar and ortho technology) produced lower forces compared to polymer (dany) and teflon (hubit) coated round and rectangular archwire. key words: load-deflection; esthetic; orthodontic archwire. (j bagh coll dentistry 2015; 27(2):154-157). introduction the demand for esthetic orthodontic appliances is increasing, and the development of materials that present acceptable esthetics for the patients and an adequate clinical performance for clinicians is needed.1 there has been continuing interest in the development and use of esthetic and effective orthodontic archwires. the evolution of wire manufacturing technology and the development of new orthodontic techniques have led to the search for better quality alloys, more biologically effective for the teeth and supporting tissues. aesthetics has become an important and integral part of the orthodontic treatment. with the invention of revolutionary aesthetic brackets, the need for the aesthetic wires became very strong. 2 most fixed appliances components are metallic in nature.this problem was partially solved with introduction of esthetic orthodontic brackets and archwires. however conventionally used orthodontic archwires which are made up of metal such as stainless steel, nickel titanium etc. have excellent mechanical properties but are poor esthetically. 3 such archwires are replaced by aesthetic coated archwires. 4 materials used in coating are polymers such as synthetic fluorine-containing resin or epoxy resin composed mainly of polytetrafluoroethylyene, which is used to simulate tooth color. 5 (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. the growing demand for invisible orthodontic treatment has led to remarkable advancements in aesthetic archwire technology, from ptfe and vapor-parylene coating to nonmetallic arches. these wires will continue to improve with regard to appearance, durability, and biomechanical control. nonmetallic arches such as fiberreinforced and self-reinforced polymers are likely the future of aesthetic orthodontic wires, and they may someday replace traditional nickel-titanium and stainless steel wires in patients receiving ceramic braces.6 recently, coating technology for metallic biomedical materials based on ionimplantation technique has been developed. 7 materials and methods six brands of orthodontic archwires were investigated: astar (epoxy coated, china), dany (polymercoated, korea), hubit (teflon coated, korea), g&h, opal and ortho technology (epoxy coated, usa) with sizes of 0.016 inch and 0.019x0.025 inch.maxillary 0.022x0.028 inch slot self-ligating brackets were bonded to the teeth surfaces of the dental arch model except for the first molars to which molar tubes were attached. secure attachment was achieved forthe brackets and buccal molar tubes by bonding the base of them to the crown. accurate slot alignment was achieved by using a plain 0.021x0.025 inch stainless steel archwire as a former while the bonding was light cured.the test was carried out by deflecting the wire at15mm between the midpoints of the brackets. j bagh college dentistry vol. 27(2), june 2015 load-deflection pedodontics, orthodontics and preventive dentistry155 this interbracket distance was derived from typical tooth dimensions.8 the bending test was carried outin both palatal and gingival deflectionsin a water bath at temperature 37°c ±0.5°c with digital thermometer controlusing a universal material tester.each bending test was done 10 times, with a new piece of wire for each repetition (fig.1). load at maximum deflection of 2mm and unloading phase at 1.5mm deflection were registered. figure 1: a modified bending test procedure was carried out on the tested archwire by the pressure of the metal blade in (a) palatally and (b) gingivally directions. results the load-deflection curves for the two niti wires from six brandsusing gingival and palatal deflections are shown in fig. 2 when the wires were loaded to 2.0mm deflection and then unloaded. in each wire the hysteresis loop was observed. as the deflection reduced from the maximum 2.0mm, the load decreased then the curve showed a plateau where the deflection decreased finally and went back to zero. the results of the anova and lsd show that the forces generated by the six brands of the two niti wire gauges at loading and unloading showed highly significant difference at the p<0.001 level. in general, for round wire, hubit showed high loading and unloading forces while g&h gave the lowest forces. whereas for rectangular wire, dany displayed high loading and unloading forces while g&h gave the lowest forces. discussion many of the load deflection curves of niti orthodontic wires have so far been derived from the freeend, simple three point bending tests but in the present study, the bending test was performed on a dental arch model with the wire being restrained in self ligating brackets simulating the orthodontic treatment of the malaligned upper right canine by palatal and gingival deflection. the modified bending test produced loaddeflection diagrams consisting of an upper loading curve and a lower unloading curve. the loading curve represents the force needed to engage the wire in the bracket of the displaced canine, whereas the unloading curve represents the forces delivered to the teeth during treatment stages.9in this study self-ligating brackets were used because of their lower friction than that of conventional brackets with elastomeric ligatures.10, 11 for 0.016 inch archwires, g&h presented with lower forcewhile the hubit wires presented with higher force in both loading and unloading. this could be due to the facts that the teflon (hubit) layer adds a minimal thickness (.0008 to .001 inch) to the archwire, while the epoxy (g&h) coating adds more significant thickness (.002 inch) to the archwire, 6 so the coating of epoxy is thicker than that of the ptfe layer and may result in a smaller niti inner core inside them. for 0.019x0.025 inch wires, the highest force values were for dany wires while the lowest were for g&h and opal wires in both loading and unloading. this could be due to the thickness of the coating of polymer wire (dany) is approximately 0.001 inch less than that of epoxy wire (g&h, opal ) .4 the curvesfor the two niti wires from six brandspalatally deflected at the same deflection and of the same size, demonstrated a small and narrow hysteresis loop, while gingivally deflected a b j bagh college dentistry vol. 27(2), june 2015 load-deflection pedodontics, orthodontics and preventive dentistry156 wires had similar behavioural characteristics (wide hysteresis curves) with wider range of forces during the loading and unloading phases and lower working forces.this may be due to that the palatally deflected wires did not express their superelasticity due to the insufficient force for inducing the martensitic transformation during loading and the increased force for reverse transformation during unloading it means that more austenite can be transformed during the formation of sim. 12, 13 the majority of the round wires at 2mm loading deflection showed higher force values during gingivally deflection test while at 1.5mm unloading, all the round wires showed higher force values duringpalatally deflection. this may be due to that the archwires were more constrained in the bracket slots gingivally that lead to more frictional resistance whichgave higher force values to exceeds the overall increase in the frictional resistance. 14 for rectangular wires in loading and unloading, the highest force values were shown during palatal deflection than gingival deflection. this may be due to the rectangular wires being thicker in palatal aspect than gingival aspect plateau values were measured in the present study because theseare frequently used to express a measure of super elasticity and force stability of niti wires.the wires with small plateau gap values were the more superelastic and force stability than the wires with large plateau gap values. 0.016 inch and 0.019x0.025 inch hubit,0.019x0.025 inch dany wires showed the least super elasticity values, while 0.016 inch opal, 0.019x0.025 inch g&h, astar wires showed the highest super elasticity values. this indicates that although wires may have comparable plateau gradients, consideration should also be given to the load levels associated with these plateau measurements. 15 because hubit and dany wires provided the highest unloading values for the 1.5 mm and 1.0 mm load-deflection tests, this plateau gap represented a particularly small proportional change in force level. percentage of hysteresis in the round wire was smaller than in rectangular wires. this agrees with garrecand jordan16 who stated that for the same maximum deformation, the volume of sim increases with the cross-sectional dimension. therefore, the area of the mechanical hysteresis increases. the stored elastic energy increases with the same proportion and will facilitate the reverse transformation. in this study almost wires showed higher hysteresis in gingival deflection test than in palatal deflection test, which may be due to the increased binding and higher loading forces than in palatal deflection test. these higher loading forces induce more martensitic transformation during loading and the decreased force for reverse transformation during unloading. 17 figure 2: load deflection curves for the two niti wires from six brands (a) for 0.016 inch using gingival deflection test (b) ) for 0.016 inch using palatal deflection test (c) for 0.019x0.025 inch using gingival deflection test (d) for 0.019x0.025 inch using palatal deflection test. j bagh college dentistry vol. 27(2), june 2015 load-deflection pedodontics, orthodontics and preventive dentistry157 as conclusion; 1. generally coated epoxy wires (g&h, opal, astar and ortho techonology) produced lower forces compared to polymer (dany) and teflon (hubit) coated round and rectangular archwire. 2. all the wires showed hysteresis in their load deflection curves where g&h wires showed the widest loadingunloading deflection curves. 3. all the wires showed significant differences in their load deflection curves, but these differences were more evident in round wires than in rectangular wires. 4. the maximum loading force of round wires in gingival deflection were higher than by palatal deflection but it gave wider hysteresis curves resulting in lower unloading forces. 5. the force decline during unloading (plateau gap) ranged between (18 to 34%) for round wires and (17 to 37%) for rectangular wires. references 1. elayyan f, silikas n, bearn d. mechanical properties of coated orthodontic brackets. am j orthod dentofacial orthop 2010; 137(2): 213–17. 2. agwarwal a, agarwal dk, bhattacharya p. newer orthodontic wires: a revolution in orthodontics.http://orthocj.com/ in april 2011. 3. elayyan f, silikas n, bearn d. ex vivo surface and mechanical properties of coated orthodontic archwires. eur j orthod 2008; 30(6): 661-7. 4. alavi s, hosseini n. load-deflection and surface properties of coated and conventional superelastic orthodontic archwires in conventional and metalinsert ceramic brackets. iran j den res 2012; 9(2):133-8. 5. ramadan aa. removing hepatitis c virus from polytetrafluoroethylene coated orthodontic archwires and other dental instruments. east mediterr health j 2003; 9(3): 274-8. 6. kravitz nd. aesthetic archwire. http://www.orthodonticproductsonline.com on 29/5/2013. 7. sridharan k, anders s, nastasi m, walter kc, anders a, monterio or, ensinger w. nonsemiconductor application of piii&d. in: anders a (ed). handbook of plasma immersion ion implantation and deposition. weinheim, germany: wiley-vch; 2004: 553-637. 8. mallory dc, english jd, powersjm, brantley wa, bussa hi. force-deflection comparison of superelastic nickel-titanium archwires. am j orthod dentofacial orthop 2004; 126(1): 110-2. 9. segner d, ibe d. properties of superelastic wires and their relevance to orthodontic treatment. eur j orthod 1995; 17: 395-402. 10. voudouris jc. interactive edgewise mechanisms: form and function comparison with conventional edgewise brackets. am j orthod dentofacial orthop 1997; 111 (2): 11940. 11. sfondrini mf, fraticelli f, rosti f, scribante a, gandini p. frictional properties of self-ligating brackets and low-friction ligatures.curr res dent 2012; 3(1): 1-6. 12. gatto e, mateares g, di bella g, nucera r, cordasco g. load deflection characteristics of super and thermal ni-ti wires. eur j orthod 2011; 10: 1-9. 13. liaw yc, su yy, lai yl, lee sy. stiffness and frictional resistance of a superelastic nickel-titanium orthodontic wire with low-stress hysteresis. am j orthod dentofacial orthop 2007; 131(5): 578.e12-8. 14. fruge jb. forces from superelastic cu-ni-ti orthodontic leveling wires, deactivated in two directions through active and passive self-ligated bracket sets. master thesis collage of dentistry, university of saint louis, 2008. 15. wilkinson pd, dysart ps, hood ja, herbison gp. load-deflection characteristics of superelastic nickeltitanium orthodontic wires. am j orthod dentofacial orthop 2002; 121(5): 483-95. 16. garrec p, jordan l. stiffness in bending of a superelastic ni-ti orthodontic wire as a function of cross sectional dimension. angle orthod 2004; 74(5): 691-6. 17. meling tr, ødegaard j. short term temperature changes influence the force exerted by superelastic nickel titanium archwires activated in orthodontic bending. am j orthod dentofacial orthop 1998; 114(5): 503-9. http://orthocj.com/ http://www.orthodonticproductsonline.com j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 16 an evaluation of canal transportation and centering ability at different levels of root canals prepared by self-adjusting file using computed tomography (a comparative study) hikmet a. sh. al-gharrawi, b.d.s., m.sc. (1) farah salahalden abbas, b.d.s., m.sc. (2) abstract background: the new concepts and technologies continue to change the dynamics of endodontic practices in the world. rapid and significant changes in techniques, instrument design, and the type of metals used to manufacture endodontic instruments which have been made during the last few years in an attempt to overcome canal preparation errors. the purpose of this study is to measure and compare canal transportation and centering ability of self adjusting file with two rotary nickel-titanium (ni-ti) systems, protaper and biorace at different levels. material and methods: forty five distal roots of mandibular first molars with moderate curvature were selected using schneider method. roots were divided randomly into 3 groups of 15 each and were scanned using computed tomography (initial scan). after canal preparation with protaper (group a), biorace (group b), and self adjusting file (group c) the roots were rescanned (final scan), the degree of canal transportation and centering ability were assessed at apical (4 mm), middle (6 mm), coronal (9 mm) sections using computed tomography. the collected data were statistically analyzed using anova and least significant difference tests. results: there were no statistically significant differences among the groups at level 4 mm and level 9 mm (p ˃ 0.05). however, at level 6 mm there was a highly significant difference between (a) and (b) groups (p ˂ 0.01) and there was a significant difference between (a) and (c) groups (p ˂ 0.05). there were no statistically significant differences among different levels of (a) and (c) groups (p ˃ 0.05), while (b) group showed a highly significant difference between 4 mm and 9 mm levels and between 6 mm and 9 mm levels (p ˂ 0.01). regarding canal centering ability, there was no statistically significant difference among the three groups at different levels (p ˃ 0.05)., while (b) group showed a significant difference between 4 mm and 9 mm levels (p ˂ 0.05), and a very highly significant difference between 6 mm and 9 mm levels (p ˂ 0.001). conclusion: the study demonstrated that canal preparation with the three designs of ni-ti instruments produced canal transportation. self adjusting file group showed less canal transportation than protaper group. there was a comparable value of canal centering ability among different levels in each group except in biorace group. keywords: canal transportation, self adjusting file system, computed tomography. (j bagh coll dentistry 2014; 26(1):16-23). introduction the primary aim of any preparation of root canal system is to enlarge the root canal space to facilitate either disinfection by antibacterial agents or to prevent reinfection through the placement of a fluid-tight root canal filling in combination with a sufficient coronal restoration. despite recent advances in the field of endodontic instruments and devices, the mechanical preparation of a curved root canal is still a challenge even for very skilled and experienced clinicians (1). different, well-described preparation errors may result during the shaping of these curved root canals, such as canal transportation, straightening, or deviation (2). as most root canals are curved (3), a high prevalence of preparation errors or canal aberrations has been reported (4). the new concept and technologies continues to change the dynamics of endodontic practices in the world. (1)assistant professor. department of conservative dentistry. college of dentistry, al-mustansiria university. (2)assistant lecturer. department of conservative dentistry. college of dentistry, al-mustansiria university. rapid and significant changes in techniques, instrument design, and the type of metals used to manufacture endodontic instruments have been made during the last few years in an attempt to overcome canal preparation errors (5). the convex triangular cross section of protaper instruments reduces the contact areas between the file and the dentin. the greater cutting efficiency inherent in this design has been safely improved by balancing the pitch and helix angle, preventing the instruments from inadvertently screwing into the canal (6). the major goal of biorace is to achieve apical preparation sizes efficiently and safely that with the addition of antimicrobial irrigation will effectively disinfect the canal. the unique aspect of this sequence is that the apical sizes of most of the teeth can be achieved with only five to seven instruments depending on the root canal anatomy (7). file shows flutes and reverse flutes alternating with straight areas; this design reduces the tendency to thread the file into the root canal (8). the self adjusting file (saf) which is a new concept in cleaning and shaping was developed to overcome the inherent remaining problems of the nickel-titanium instruments. the saf has no j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 17 blades and no rigid predetermined form; therefore, it does not impose its shape on the canal but rather complies with the canal’s original shape. this is true both circumferentially and longitudinally (9). different methodologies have been used to assess the effects of different endodontic instruments on canal transportation. classical in vitro methods of studying the morphologic characteristics of root canal systems either produce an irreversible change in the specimen or provide only a 2-dimensional projected image (10,11). computerized tomography (ct) has been shown to be useful in endodontic evaluations, because it nondestructively measures the amount of dentin removed from root canal walls (12-14). this study was designed to use ct to evaluate the canal transportation of saf in comparison with protaper and biorace. material and methods sample forty five permanent freshly extracted human mandibular first molars were selected for this study. the gender, pulpal status and reason for extraction not considered, and criteria for teeth selection included the following (15): 1. age (18-35). 2. roots with mature, centrally located apical foramen. 3. roots devoid of any resorption, cracks, caries. 4. the distal roots have length of 11 mm from the apex up to furcation area. 5. curvature at mesial-distal plane with (15) degrees. 6. patent apical foramen. sample preparation after extraction, the collected teeth were thoroughly washed and cleaned of all debris by immersion in sodium hypochlorite (naocl) for 30 minutes , calculus were removed by curette, then they were stored in distilled water with thymol crystals 0.1% at room temperature . the roots were examined for crack using the halogen light curing unit. teeth were radiographed in straight buccolingual direction (fixed on radiographic wood plate. the images so recorded were taken into vector drawing and edited using coral draw 9.0 software and an outline in vector form were drawn around the tooth and also the root canal. the angle of canal curvature was calculated by the method described by schneider in 1971, and two straight lines were drawn, the first line from the canal orifice parallel to the axis of the canal and the second line passes through the apical foramen until its intersection with the first line where the curvature starts to occur (fig.1). teeth with distal root that have curvature other than 15 degree of curvature and have multiple canals were excluded. 15 deg rees fig.1: soft ware (corel draw 9) used to measure the angle of root curvature. using a diamond disk with straight hand piece at a speed of 25000 rpm and water coolant, the distal roots of teeth were marked at 11.5 mm and sectioned perpendicular to the long axis of root at the furcation area to facilitate straight line access for canal instrumentation procedure, to get a flat reference point for measurement, and to eliminate the variables in the access opening, since if the crown is present each tooth would have its own access design (16). remnant of pulp tissue in each root was removed by barbed broach, then a size 20 k-file was placed into the canal until it was visible at the apical foramen to verify the location of apical foramen and patency of the canal, and the correct working length (wl) was established 1 mm short of the root length. mold construction the roots were embedded in clear cold cure acrylic (13). ten ml disposable plastic syringe was used as a mold. the syringe was prepared by removing the barrel and cutting the plunger at the base to obtain a flat cutting surface. the barrel of syringe was cut off into 1.5 cm length with cutter. then the coronal end of the sectioned root was fixed by heating the pink sheet wax on the flame and adapted to the flat surface of syringe plunger and the parallism of root (straight coronal part of the root) was checked with the aid of analyzing rod of dental surveyor. the acrylic was prepared by mixing transparent cold cure acrylic powder and liquid according to the manufacturer’s instructions in porcelain jar, and was left till the acrylic reached the dough stage, at this stage the mixture was j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 18 ready for loading into the barrel of syringe, the plunger of syringe with root fixed on its flat cut surface were pushed into acrylic paste with gentle pressure to allow the complete embedding of the root into the acrylic. the material was allowed to cure under cooled water which is necessary to compensate for the anticipated rise in the temperature of the samples subsequent to the exothermic curing reaction of the cold cure resin. the acrylic molds were allowed to cure completely for at least 30 min as recommended by the manufacturers. then acrylic blocks were stored in a plastic containers filled with distilled water. sample grouping the roots were divided randomly into three groups of fifteen roots each. group a: 15 samples were prepared by rotary protaper files. group b: 15 samples were prepared by rotary biorace files. group c: 15 samples were prepared by saf. ct scanning the samples a special radiographic wood plate was locally prepared for the purpose of this study with three halls at the same line and at an even distance from the boundary of the plate, and then six metal clips were used as a marker for the number of the specimen in the plate during computed tomography scanning procedure. the samples were mounted on the radiographic plate to allow reproducible results of the initial and final ct scan. roots were fixed on a special wood plate and aligned so that the long axis of the roots were perpendicular to the beam (the beam passes from the mesial side of the root for each sample which determined by red line).they were scanned at 80 kv and 30 ma with an isotropic resolution of 0.22mm, to determine root canal cross section at 4 mm, 6 mm, 9 mm from root apex. the images were displayed on philips personal computer screen from the option ct viewer. then when selecting the slab mode cross hair lines appear to determine the specimen under the study and the axis that passes through the root canal, from the slab mode the images were viewed both in the axial and coronal views as shown in (fig.2). fig. 2: root canal shapes under the ct scanning unit (initial scan) first, from the axial view the canal was measured at 4 mm, 6mm, 9mm from the apex, to save the distance at specific location from the apex, the rotation center was selected. then the coronal view was selected to view the canal cross section at the same location. after that, the distance from the edge of un-instrumented canal to the periphery of the root (mesial and distal) was measured at each level for each sample. root canal instrumentation (group a): instrumentation was performed with a crown down technique using rotary protaper system (dentsply, maillefer, switzerland), sequence used (sx-f4) operated by x-smart micromotor according to manufacturer instructions. the speed of the hand piece was fixed on 250 rpm, torque 5 ncm, gear ratio 16:1. (group b): instrumentation was performed with a crown down technique using biorace system (chaux-de-fonds, switzerland), sequence used (br0-br5) operated by xsmart micromotor according to manufacturer instructions. the speed of the hand piece was adjusted to 500rpm, torque 1ncm gear ratio 16:1. (group c): instrumentation was performed with self adjusting file system (re dent nova) that is operated with transline (in and out) vibrating handpieces with 3,000 vibrations per minute and an amplitude of 0.4 mm, torque set to maximum, gear ratio 1:1. the (1.5 mm) saf was inserted into the canal while vibrating and was delicately pushed in until it reaches the predetermined working length, then operated with in-andout manual motion and with continuous irrigation using two cycles of 2 minutes each for a total of 4 minutes per canal. for the three groups the canals were irrigated between each instrument and other with 3 ml of 3% (naocl) using a 27 gauge needle (insertion depth of needle one third of the canal), then 1 ml of 17 % edta were used after instrumentation and left in the canal for 1 minute to remove the smear layer then rinse with 3 ml of 3% naocl. finally the canals were rinsed with 5 ml distilled water to avoid development of naocl crystals. rescanning after instrumentation; the samples of each group were re-scanned to determine the distance from the edge of instrumented canal to the j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 19 periphery of the root (mesial and distal) and then comparing this with the same measurements obtained from the un-instrumented images to be used in the determination of the canal transportation and the centering ability of the instruments. the following formula was used for the calculation of transportation: (a1 – a2) (b1 – b2) where:a1: is the shortest distance from the mesial edge of the root to the mesialedge of the uninstrumented canal, b1: is the shortest distance from distal edge of the root to the distal edge ofthe uninstrumented canal, a2: is the shortest distance from the mesial edge of the root to the mesial edge of the instrumented canal and b2: is the shortest distance from distaledge of the root to the distal edge of the instrumented canal.according to this formula, a result other than 0 indicates that transportation has occurred in the canal (17). the mean centering ratio indicates the ability of the instrument to stay centered in the canal (17). it was calculated for each section using the following ratio: (a1 – a2)/ (b1 – b2). if these numbers are not equal, the lower figure is considered as the numerator of the ratio. according to this formula, a result of 1 indicates perfect centering, more than 1 canal deviation inward and less than 1 canal deviation outward (17). results the results of the descriptive statistics which include the minimum, maximum, mean and standard deviation of canal transportation for all groups at different levels are shown in (table 1) and (fig. 3). it has shown that protaper group has the highest mean values of canal transportation at all levels, while biorace has the lowest mean values at the apical and middle levels. table 1: descriptive statistics of canal transportation for all groups groups level of section mean sd min. max. a 4 mm 0.206 0.116 0 0.40 6 mm 0.207 0.127 0 0.50 9 mm 0.233 0.176 0 0.60 b 4 mm 0.113 0.064 0 0.20 6 mm 0.113 0.064 0 0.20 9 mm 0.220 0.152 0 0.50 c 4 mm 0.173 0.149 0 0.50 6 mm 0.133 0.072 0 0.20 9 mm 0.167 0.089 0 0.30 fig. 3: bar chart of mean canal transportation for all groups analysis of variance (anova) test was performed to identify the presence of any statistically significant difference among the means of canal transportation of all groups, at each level (table 2) anova test revealed that there were no statistically significant differences among the groups at level 4 mm and level 9 mm and there was a significant difference among the groups at 6mm level. table 2: anova test for canal transportation among groups at each level cross section a b c comparison mean mean mean p value sig. 4 mm 0.206 0.113 0.173 0.091 ns 6 mm 0.207 0.113 0.133 0.021 s 9 mm 0.233 0.220 0.167 0.414 ns ns: non significant at level p ˃ 0.05, s: significant at level p ≤ 0.05. least significant difference test (lsd): was performed for multiple comparisons between groups, (table 3). the results of (lsd) test showed that at level 6 mm there was a highly significant difference between (a) and (b) groups and there was a significant difference between (a) and (c) groups. table 3: lsd for mean transportation among the groups at level 6 mm. level of section groups pvalue sig. 6 mm a b 0.009 hs c 0.036 s b c 0.557 ns ns: non significant at level p ˃ 0.05, s: significant at level p ≤ 0.05, hs: highly significant at level p ≤ 0.01. one way analysis of variance (anova) test revealed that there were no statistically significant differences among different levels of (a) and (c) j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 20 groups and there was a highly significant difference among the different levels of b group as shown in (table 4). table 4: anova test for canal transportation among the different levels within each group groups level of section mean pvalue sig. a 4 mm 0.206 0.840 ns 6 mm 0.207 9 mm 0.233 b 4 mm 0.113 0.008 hs 6 mm 0.133 9 mm 0.220 c 4 mm 0.173 0.562 ns 6 mm 0.133 9 mm 0.167 ns: non significant at level p ˃ 0.05, hs: highly significant at level p ≤ 0.01. lsd test revealed that (b) group showed a highly significant difference between 4 mm and 9 mm levels and between 6 mm and 9 mm levels as shown in (table 5). table 5: lsd for mean transportation among levels of biorace group group level of section p-value sig. b 4 mm 6 mm 1.000 ns 9 mm 0.007 hs 6 mm 9 mm 0.777 hs ns: non significant at level p ˃ 0.05, hs: highly significant at level p ≤ 0.01. the results of the descriptive statistics which include the minimum, maximum, mean and standard deviation of canal centering ability for all groups at different levels are shown in (table 6) and (fig. 4). it has shown that protaper and self adjusting file have comparable values of canal centering ability at apical and coronal levels; also there were comparable values among levels in each group except in biorace group. table 6: descriptive statistics of canal centering ability for all groups groups level of section mean sd min. max. a 4 mm 1.025 0.681 0.33 3.0 6 mm 1.194 0.641 0.40 2.66 9 mm 1.056 0.535 0.25 2.0 b 4 mm 1.083 0.340 0.60 1.50 6 mm 1.321 0.399 0.66 2.0 9 mm 0.778 0.456 0.28 2.25 c 4 mm 0.925 0.375 0.33 1.66 6 mm 1.167 0.422 0.60 2.0 9 mm 0.915 0.321 0.50 1.70 fig. 4: bar chart of mean canal centering ability for all groups one way analysis of variance test (anova) revealed that there were no statistically significant differences among the groups at different levels as shown in (table 7). table 7: anova test for canal centering ability among the groups section a b c comparison mean mean mean p-value s 4 mm 1.025 1.083 0.925 0.673 n 6 mm 1.194 1.321 1.167 0.666 n 9 mm 1.056 0.778 0.915 0.245 n ns: non significant at level p ˃ 0.05 one way analysis of variance test (anova) revealed that there were no statistically significant differences among different levels within each group as shown in (table 8). table 8: anova test for canal centering ability among different levels within each group groups level of section mean p-value sig. a 4 mm 1.025 0.733 ns 6 mm 1.194 9 mm 1.056 b 4 mm 1.083 0.003 hs 6 mm 1.321 9 mm 0.778 c 4 mm 0.925 0.128 ns 6 mm 1.167 9 mm 0.915 ns: non significant at level p ˃ 0.05, hs: highly significant at level p ≤ 0.01. lsd test revealed that (b) group showed a significant difference between 4 mm and 9 mm levels and a very highly significant difference between 6 mm and 9 mm levels as shown in (table 9). j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 21 table 9: lsd for mean centering ability among different levels of biorace group group level of section pvalue sig. b 4 mm 6 mm 0,111 ns 9 mm 0.044 s 6 mm 9 mm 0.001 vhs discussion during instrumentation of the root canal, the development of a continuously tapered form and the maintenance of the original shape and position of the apical foramen are important objectives. the final results of the instrumentation of curved root canals may be influenced by several factors: flexibility and diameter of the endodontic instruments, instrumentation techniques, location of the foraminal opening, and the hardness of dentin (18). in this study torque limited electric motor (x smart motor) was used for instrumentation that can be programmed for different types of rotary instruments and is able to rotate the file in reverse direction when the file is locked in canal in order to prevent file separation. an advantage of the present study was the fact that it did utilize roots of natural extracted teeth, as physical and chemical characteristics of the acrylic canals differ from natural tooth. in addition, a moderate root canal curvature of 15 degree was selected for the sample of this study to evaluate the ability of the instruments to preserve the canal with moderate degree of curvature and with the purpose of achieving precise measurements. in this study ct imaging techniques have been evaluated as non invasive methods for the analysis of canal geometry and efficiency of shaping techniques. with this technique it is possible to compare the anatomic structure of root canal (cross section) before and after instrumentation which is not possible with conventional radiography (19). the occurrence of up to 0.15 mm of canal transportation has been considered to be acceptable. conversely, canal transportation reaching above 0.30 mm may have a negative impact on apical seal after obturations (1). under the condition of this study none of the specimens presented transportation levels ˃ 0.23 mm. the mean transportation at all levels was the greatest for protaper. this is probably because of the greater amount of dentin removal in all levels of the root canal prepared by protaper. this is due to the increased taper of protaper shaping files of up to 19%, whereas biorace are available only with tapers of maximum 8% and saf 4%. there was no statistically significant difference among the groups at level 4 mm and level 9 mm. however there was a statistically significant difference among the groups at level 6 mm. probably these differences could be detected because, at this point of the curvature there is a higher stress on the instrument owing to the critical changes on the relationship of diameter and flexibility. the biorace showed less canal transportation than protaper with a highly significant difference at level 6 mm, this is due probably to biorace design with altering straight and twisted areas along the instrument shank and simple triangular cross section may eliminate screwing effect. this is due probably to the design feature of protaper whose cutting edges do not have radial lands and at the same time display more positive rake angle this feature predisposes the canal to greater transportation. the result of this study agreed with result of study done by schafer and vlassis (20) whose showed that race created no canal aberration and maintained working length well in curved canals, and disagree with other authors whose showed more canal transportation with race files, compared with heroshaper and protaper. the saf showed less canal transportation than protaper with a significant difference at level 6 mm, this is due probably to the design difference of saf whose metal meshwork and absence of metal core make the file compressible and does not impose its shape on the canal but rather complies with the canal’s original shape. the result of this study agreed with the study of paque et al (21) about the preparation of oval shaped root canals in mandibular molars using niti instruments, they found that there was a significant difference between protaper and saf. the results of this study agreed with the study of paque and peters (22) whose found larger canal transportation for rotary protaper instruments than for the saf in maxillary molar canals. there was no statistically significant difference among different levels in protaper and saf groups, while biorace showed a highly significant difference between 4mm and 9 mm levels and between 6 mm and 9 mm levels this is due probably to the design of instruments br 0, br 1, br 3 with tapers 0.08, 0.05, 0.06 respectively, in which tips do not touch the canal walls when the instrument are at full working length which allow larger transportation at coronal level. this study agreed with the study of aldameh (23) in which she found that there was a significant difference between 4 mm and 9 mm levels and between 6 mm and 9 mm levels. j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 22 regarding canal centering ability, there was no statistically significant difference among the three groups at different levels. the results of this study agreed with the study of narayanan et al (24) in which they compared the centering ability of three rotary niti instruments profile, race and protaper, and they found that there was no statistically significant difference among three groups at different levels under computed tomography. while biorace showed a significant difference between 4 mm and 9 mm levels and a very highly significant difference between 6 mm and 9 mm levels, this is probably lie in preliminary enlargement of canals to size 20 kfile. the results of this study agreed with the study of al-dameh (23), in which she found a significant difference between biorace different levels. the results of this study agreed with the study of javaheri and javaheri (25), in which they compared the three rotary niti systems hero 642, protaper and race, they found that race showed less canal deviation than others.also agreed with the study of bonaccorso et al (26) in which they compared the centering ability of three rotary niti files protaper, biorace and mtwo in resin blocks and they found that biorace showed a superior centering ability. as conclusions; 1. this study demonstrated that canal preparation with the three designs of ni-ti instruments produced canal transportation. 2. biorace group showed less canal transportation than protaper and saf groups. 3. saf group showed less canal transportation than protaper group. 4. protaper and saf groups have comparable values of canal centering ability at apical and coronal levels. 5. there were comparable values of canal centering ability among different levels in each group except in biorace group. references 1. peters oa. current challenges and concepts in the preparation of root canal systems: a review. j endod 2004; 30:559-67. 2. weine f, kelly r, lio p. the effect of preparation procedures on original canal shape and on apical foramen shape. j endod 1975; 1: 262–6. 3. scha¨fer e, diez c, hoppe w, tepel j. roentgenographic investigation of frequency and degree of canal curvatures in human permanent teeth. j endod 2002; 28: 211–6. 4. hu¨lsmann m, peters o, dummer p. mechanical preparation of root canals: shaping goals, techniques and means. endod topics 2005: 10: 30–76. 5. tronstad l. clinical endodontics. a textbook. 2nd ed. new york: thieme; 2003. 6. hargreaves k, cohen s. cohen pathway of the pulp 10th ed. china; 2011. 7. debelian g, trope m. biorace – efficient, safe, and biological based sequence files. endotribune us. 2008; 3(3):1-7. 8. koch k, brave d. design features of rotary files and how they affect clinical performance. oral health j 2002. 9. metzger z, teperovich e, zary r, cohen r, hof r. the self-adjusting file (saf). part 1: respecting the root canal anatomy-a new concept of endodontic files and its implementation. j endod 2010; 36: 679-90. 10. gonzalez-rodríguez mp, ferrer-luque cm. a comparison of profile, hero 642, and k3 instrumentation systems in teeth using digital imaging analysis. oral surg oral med oral pathol oral radiolendod 2004; 97: 112-5. 11. mikrogeorgis g, molyvdas i, lyroudia k, nikolaidis n, pitas i. a new methodology for the comparative study of the root canal instrumentation techniques based on digital radiographic image processing and analysis. oral surg oral med oral pathol oral radiol endod 2006; 101: 125-31. 12. versiani ma, pascon ea, de sousa cj, borges ma, sousa-neto md. influence of shaft design on the shaping ability of 3 nickel titanium rotary systems by means of spiral computerized tomography. oral surg oral med oral pathol oral radiol endod 2008; 105: 807-13. 13. gergi r, abourjeily j, sader j, naaman a. comparison of canal transportation and centering ability of twisted files, pathfile-protaper system, and stainless steel hand k-files by using computed tomography. j endod 2010; 36: 904–7. 14. özer sy. comparison of root canal transportation induced by three rotary systems with non-cutting tips using computed tomography. oral surg oral med oral pathol oral radiol endod 2011; 111: 244-50. 15. gandhi a, gandhi t. comparison of canal transportation and centering ability of hand protaper files and rotary protaper files by using micro computed tomography. rsbo-2011; 8(4): 375-80. 16. pitts dl, natkin e. diagnosis and treatment of vertical root fracture. j endod1983; 8:338-46. 17. gambill jm, alder m, delrio ce. comparison of niti and stainless steel hand files using computed tomography. j endod 1996; 22: 369–75. 18. lopes h, elias c, estrela c, siqueira j. assessment of the apical transportation of root canals using the method of the curvature radius. braz dent j 1998; 9(1): 39-45. 19. mahesh m. difference between conventional x-ray and computed tomography. ct physics; chapter 1, 2001. 20. scha¨fer e, vlassis m. comparative investigation of two rotary nickel–titanium instruments: protaper versus race. part 1. shaping ability in simulated curved canals. int endod j 2004; 37: 229–38. 21. paque f, balmer m, attin t, peters oa. preparation of oval-shaped root canals in mandibular molars using nickel-titanium rotary instruments: a micro-computed tomography study. j endod 2010; 36: 703–7. 22. paque f, peters oa. micro-computed tomography evaluation of the preparation of long oval root canals in mandibular molars with the self-adjusting file. j endod 2011; 37: 517–21. j bagh college dentistry vol. 26(1), march 2014 an evaluation of restorative dentistry 23 23. al-dameh a. root canal preparation with two different rotary systems: comparative study assessed by micro-computed tomography. ph.d. thesis, university of otago, dunedin, new zealand, 2011. 24. narayanan l, revathi m, rao cvn. ct analysis of transportation and centering ratio using three rotary ni-ti files in curved root canalsan in vitro study. endodontol 2005; 3: 1-7. 25. javaheri hh, javaheri gh. a comparison of three niti rotary instruments in apical transportation. j endod 207; 33: 284-6. 26. bonaccorso a, cantatore g, condorelli gg, schafer e, tripi tr. shaping ability of four nickel-titanium rotary instruments in simulated s-shaped canals. j endod 2009; 35: 883-6. j bagh college dentistry vol. 29(2), june 2017 assesment of vascular oral diagnosis 61 assessment of vascular and lymphatic vessels density in benign vascular lesions using cd34 and d2-40 immunohistochemical markers jawaher m. tater, b.d.s. (1) bashar h. abdullah, b.d.s., m.sc., ph.d. (2) abstract background: vascular tumors and malformations, comprising a broad category of lesions often referred to as vascular anomalies. hemangioma, represents a variety of vascular lesions (both malformations and tumor), while lobular capillary hemangioma is a common vascular lesion of the skin and mucous membranes that occurs mainly in children and young adults. lymphangiomas are malformations of the lymphatic system. at the level of light microscopy the small lymphatics vessels may be similar to capillaries and sometimes are only tentatively identified by the nature of their contents or by immunohistochemical staining procedure. this study aimed to assess the vascular and lymphatic vessels density in benign vascular lesions using cd34 and d2-40 immunohistochemical markers. materials and methods: twenty two formalin-fixed paraffin-embedded tissue blocks of hemangioma/vascular malformation, thirty of lobular capillary hemangioma and another twenty of lymphangioma. results: lymphatic vessel density expressed by d2-40 immunomarker was found in all cases with mean (24.01±14.74) in lymphangioma ,for lobular capillary hemangioma it was (12.67±6.66) and for hemangioma was (9.77±6.82) where as the mean of microvessel density count measured by cd34 immunomarker was (49.87±31.97) for lobular capillary hemangioma , in hemangioma it was (37.42±23.40) and (25.90±12.23 ) for lymphangioma. conclusions: all vascular lesions are a mixture of blood and lymphatic vessels with different proportions, hemangioma shows high percentage of blood vessels and lymphangioma shows high percentage of lymphatic vessels. key words: vascular tumor, immunohistochemistry, d2-40, cd34. (j bagh coll dentistry 2017; 29(2):61-64) introduction vascular anomalies are heterogeneous group of congenital lesions of abnormal vascular development and may take place anywhere in the body. there is a main distinction between a vascular tumor, which grows by cellular proliferation and a vascular malformation, which represents a restricted defect in vascular morphogenesis. some of the lesions are a source of esthetic problems, while some of them are malignant; thus, the therapeutic approach is variable (1). the pathophysiology of vascular malformation, hemangioma and lymphangioma are interconnected (2). hemangioma is a term that encompasses a heterogeneous group of clinical benign vascular lesions, which is a proliferating mass of blood vessels that do not undergo malignant transformation (3). lobular capillary hemangiomas are rapidly growing, mostly exophytic lesions which may ulcerate. most lesions develop at sites of superficial trauma; when seen early, it is a solitary, bright red mass, some authors use the (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (b) professor. depart ment of oral and maxillofacial diagnosis, college of dentistry, university of baghdad. term ‘pyogenic granuloma’ to describe this lesion. lymphangiomas are rare congenital tumors, with up to 70% reported in the head and neck. they are alienated into three types: cystic (cystic hygroma), capillary, and cavernous. lymphangiomas report for approximately 25% of all vascular neoplasms in children and adolescents. about 25% of cervical cysts are lymphangiomas. differences between vascular and lymphatic capillary endothelium can be established by means of immunohistochemistry with antibodies targeted against lineage-specific substances, basal lamina, and pericytes. d2–40 is a selective monoclonal immunohistochemical marker of lymphatic endothelium in adult human tissue; it does not stain vascular endothelium (4,5). cd34, a sensitive marker for vascular epithelium was used to evaluate microvessel density in numerous tissues and intra-tumoral microvessel density (6). materials and methods the sample is consisted of twenty two formalin-fixed paraffin-embedded tissue blocks of hemangioma/vascular malformation, twenty of lymphangioma and another thirty of lobular capillary hemangioma. j bagh college dentistry vol. 29(2), june 2017 assesment of vascular oral diagnosis 62 figure 1: positive lymphatic endothelium expression of d2-40 in hemangioma (400x) figure 2: positive lymphatic endothelium expression of d2-40 in lymphangioma (400x) figure 3: positive lymphatic endothelium expression of d2-40 in lobular capillary hemangioma (400x). the samples were obtained from the archives of the department of oral and maxillofacial pathology/college of dentistry/ university of baghdad and al-shaheed ghazi hospital/ medical city / baghdad dated from (1979 till 2015). after histopathological reassessment of haematoxylin and eosin stained sections for each block, an immunohisto-chemical staining was performed using anti d2-40 monoclonal antibody and anti cd34 monoclonal antibody, assessment of lvd and mvd based on the criteria of weidner (7). results d2-40 expression the immunostaning method of d2-40 was applied to lymphangioma, hemangioma and pyogenic granuloma, where the lymphatic vessels were stained with brown coloration as seen in (figures 1, 2 and 3). in table 1, the mean±sd of lvd evaluated by d2-40 immunomarker expression, according to anova test imploded between samples groups. there was a high statistical significant difference in the mean of expression of d240 in lymphangioma in comparison to pyogenic granuloma and hemangioma (p=0.000). table 1: description of statistics obtained by immunohistochemistry of d2-40 d2-40 n mean (lvd) sd sig. lymphangioma 20 24.01 17.74 0.000 pyogenic granuloma 30 12.67 6.66 hemangioma 22 9.77 6.82 total 72 14.93 12.23 cd34 expression table 2 shows the mean ±sd of mvd evaluated by cd34 expression as brown stained blood vessels endothelial cells as seen in (figures 4, 5 and 6), according to anova test imploded between groups found a statistical significant difference (p=0.006). table 2: description of statistics obtained by immunohistochemistry of cd34 cd34 n mean (lvd) sd sig. pyogenic granuloma 20 49.87 31.97 0.006 hemangioma 30 37.42 23.40 lymphangioma 22 25.90 12.23 total 72 39.41 26.80 figure 4: positive blood vessels expression of cd34 in hemangioma (400x) figure 5: positive blood vessels expression of cd34 in lymphangioma (200x) figure 6: positive blood vessels expression of cd34 in lobular capillary hemangioma (400x) j bagh college dentistry vol. 29(2), june 2017 assesment of vascular oral diagnosis 63 table 3 shows the mean difference of lymphatic vessels density ( lvd ) measured by expression of d2-40 immunohistochemical marker subtracted from microvessels density (mvd) measured by expression of cd34 immunohistochemical marker. it also shows the percentage of lymphatic and blood vessels in hemangioma, pyogenic granuloma and lymphangioma. as lymphangioma is predominantly composed of lymphatic vessels (92.7%) while hemangioma predominantly composed of blood vessels (73.8%). according to post hoc test, whereas multiple comparisons was made between hemangioma, lymphangioma and pyogenic granuloma with different markers, a highly significant difference was found between d2-40 expression in hemangioma and in lymphangioma (0.000), and the same result found between pyogenic granuloma and lymphangioma (0.001). while a significant difference is found between cd34 marker expression in lymphangioma and hemangioma (0.002).details explained in (table 4). table 3: mean difference of lvd from mvd and the percentage of lymphatic and blood vessels in hemangioma, pyogenic granuloma and lymphangioma groups mean difference lvd from mvd percentage of blood vessels percentage of lymphatic vessels pyogenic granuloma (49.87)-(12.67) =37.2 74.6% 25.4% hemangioma (37.42)-(9.77) =27.65 73.8% 26.2% lymphangioma (25.90)-(24.01) =1.89 7.3% 92.7% table 4: multiple statistical comparisons by post hoc test dependent variable mean difference s.e. sig. d240 hemangioma lymphangioma pyogenic -14.23 3.38 .000** -2.89 3.07 .349nd lymphangioma pyogenic 11.34 3.15 .001** cd34 hemangioma lymphangioma pyogenic 11.52 7.80 .144nd -12.44 7.09 .084nd lymphangioma pyogenic -23.96 7.29 .002* nd=non significant, **highly significant (p ≤ 0.001), *significant difference (p ≤ 0.05) discussion vascular tumors are heterogeneous groups of disease with biological behavior which ranging from a hamartomatous growth to frank malignant. this study aims to define the type of vascular tissue in three benign tumors: hemangioma, lymphangioma, lobular capillary hemangioma and assessment of those tumors by using d2-40, cd34, immunohistochemical markers to identify the proportions of lymphatic and vascular vessels in those tumors. in this study, two important parameters were considered concerning with behavior of vascular tumor namely (lvd, mvd) the assessment was done by using d2-40, cd34 immunomarkers respectively. this study assessed the expression of d2-40 in benign vascular lesion, the results revealed positive d2-40 expression in all lymphangioma cases. our result agree with fukunaga (8) and galambos and nodit (9) whose found 100% positivity of d2-40 expression in lymphangioma, however it disagree with fukunaga (8) finding of d2-40 in other vascular lesion. while our result disagrees with bhawan et al. (10) whose observed a variable staining of lymphangiomas to d2-40. the source of this discrepancy according to them may be that some of the cases that were diagnosed as lymphangiomas were actually hemangiomas. this may not be uncommon, as several studies have indicated that it is difficult to distinguish lymphatic channels from venules or capillaries histomorphologically. also, the results revealed strong positive cd34 expression in lobular capillary hemangioma and hemangioma that agree with north (11) who stated that the endothelial cells of hemangioma immunoreact positively for normal j bagh college dentistry vol. 29(2), june 2017 assesment of vascular oral diagnosis 64 endothelial markers of the blood vasculature, such as cd34, and disagree with kang et al. (12) whom explained that in the pyogenic granuloma portion, cd34 was almost negatively detected, according to them this is due to heterogeneous characteristics of the lesion. also in this study we have observed cd34 positive expression in lymphangioma similar results obtained in previous studies which were explaining endothelial markers (factor viii, cd31, cd34, and ulex) expression by endothelial cells in both hemangiomas and lymphangiomas (13). the obvious capillary growth (hyper plastic granulation tissue) in lobular capillary hemangioma suggests that there should be a strong activity of angiogenic potential (14). this agreed with the finding of our study which found that cd34 expression being higher in lobular capillary hemangioma explaining the proliferative nature of that lesion. d2-40 immunomarker expression was detected in lymphangioma, hemangioma and in lobular capillary hemangioma in different percentage and density. although lymphangioma predominantly composed of lymphatic vessels detected by d2-40, however lymphangioma also containing vascular vessels. similarly, hemangioma although predominantly showed blood vessels however it was also containing lymphatic vessels. this proved that all vascular lesions are a mixture of blood and lymphatic vessels with different proportions hemangioma show high percentage of blood vessels while lymphangioma shows high percentage of lymphatic vessels. references 1. richter gt, friedman ab. hemangiomas and vascular malformations: current theory and management. international j pediatrics 2012. 2. kumar ks, jha pk, sinha rk, kumar p. oral lymphangioma: a review. 2012 3. dilsiz a, aydin t, gursan n. capillary hemangioma as a rare benign tumor of the oral cavity: a case report. cases j 2009; 9: 8622. 4. arigami t, natsugoe s, uenosono y, arima h, makati y, ehi k, yanagida s, ishigami s, hokita s, aikou t. lymphatic invasion using d2-40 monoclonal antibody and its relationship to lymph node micrometastasis in pn gastric cancer. british j cancer 2005; 93: 688-93. 5. miller rt. utility of immunostains for d2-40 in diagnostic pathology. the focus immunohistochemistry 2005: 1-2. 6. folkman j. fighting cancer by attacking its blood supply. scientific american 1996; 275(3):150-6. 7. weidner n, semple jp, welch wr, folkman j. tumor angiogenesis and metastasis—correlation in invasive breast carcinoma. new england j med 1991; 324(1):1-8. 8. fukunaga m. expression of d2-40 in lymphatic endothelium of normal tissues and in vascular tumours. histopathol 2005; 46(4): 396-402. 9. galambos c, nodit l. identification of lymphatic endothelium in pediatric vascular tumors and malformations. pediatric and developmental pathol 2005; 8(2):181-9. 10. bhawan j, silva c, taungjaruwinai wm. inconsistent immunohistochemical expression of lymphatic and blood endothelial cell markers in cutaneous lymphangiomas. j cutaneous pathol 2013; 40(9): 801-6. 11. north pe. pediatric vascular tumors and malformations. surgical pathology clinics 2010; 3(3): 455-94. 12. kang yh, byun jh, choi mj, lee js, jang jh, kim yi, park bw. co-development of pyogenic granuloma and capillary hemangioma on the alveolar ridge associated with a dental implant: a case report. j med case rep 2014; 8: 192. 13. gnepp dr. diagnostic surgical pathology of the head and neck. 2nd ed. philadelphia: elsevier health sciences; 2009. 14. yuan k, jin yt, lin mt. the detection and comparison of angiogenesis-associated factors in pyogenic granuloma by immunohistochemistry. j periodontol 2000; 71(5): 701-9. المستخلص یشار الیھا باألوعیة الدمویة الشاذة .أن مصطلح األورام الوعائیة تمثل مجموعات واسعة من الآلفات غالبا والتشوھات الوعائیة ماألورا : الخلفیة االوعیة الدمویة أورام األورام الوعائیة الشعریة المفصصة ھي تستخدم عادة لشرح مجموعة متنوعة من اورام االوعیة الدمویة والتشوھات الخلقیة. .عند مستوى الفحص التي تصیب أألغشیة المخاطیة والجلدیة عند االطفال والشباب.اما األورام اللمفیة فھي التشوھات التي تحدث في النظام اللمفي میزھا فقط بواسطة طبیعة محتواھا او بالمجھر الضوئي فأن االوعیة اللمفیة الدقیقة تكون مشابھھ لألوعیة الدمویة الدقیقة وفي بعض االحیان یمكن ت بواسطة استخدام الفحص المناعي النسیجي الكیمیائي. المناعیة النسیجیة الفحوصات ذللك بإجراء تم اللمفاویة في اورام االوعیة الحمیدة وقد األوعیة الدمویة و كثافة : تھدف ھذه الدراسة لتقییماألھداف cd34 ,d2-40 الكیمیائیة عینة للورم الوعائي الشعریة 30عینة للورم الوعائي معالج بالفورمالین والمغمور بالبارافین و 22:في ھذه الدراسة العمل ئقوطرا المواد .عینة اخرى للورم اللمفي جمعت من ارشیف المختبرات تضمنت خالل ھذه الدراسة 20المفصص و ) بالنسبة (14.74±24.01قد وجدت في كافھ الحاالت وبمعدل d2-40ان كثافة االوعیة اللمفاویة والموضحة من خالل االجسام المناعیة :النتائج .وكان كثافة (6.82±9.77) ) لألورام الوعائیة الشعریة المفصصة وبالنسبة لألورام الوعائیة فكان المعدل(6.66±12.67لألورام اللمفیة بمعدل لألورام الوعائیة الشعریة (31.97±49.87)قد وجدت في جمیع الحاالت وبمعدل cd34ة الدمویة الموضحة من خالل االجسام المناعیة االوعی ) بالنسبة لألورام اللمفیة .12.23±25.90) لألورام الوعائیة((23.40±37.42المفصصة الدمویة واللمفیة بنسب متفاوتة ,االورام الدمویة تظھر نسبة عالیة من االوعیة جمیع االورام الوعائیة ھي عبارة عن خلیط من االوعیة :االستنتاجات سبة عالیة من االوعیة اللمفاویة.الدمویة بینما تظھراالورام اللمفاویة ن j bagh college dentistry vol. 29(2), june 2017 assesment of vascular oral diagnosis 65 type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p): 1817-1869, issn (e): 2311-5270 74 review article potentials of salivary matrix metalloproteinase 9 to discriminate periodontal health and disease ahmed ramzi atarchi1 1 bright now dental, cleveland, ohio, usa. * correspondence: ahmedatarchi77@gmail.com abstract: periodontitis is a chronic inflammatory disease resulted from aggravated immune response to a dysbiotic subgingival microbiota of a susceptible host. consequences of periodontitis are not only limited to the devastating effect on the oral cavity but extends to affect general health of the individual and also exerts economic burdens on the health systems worldwide. despite these serious outcomes of periodontitis; however, they are avoidable by early diagnosis with proper preventive measures or non-invasive interventions at earlier stages of the disease. clinically, diagnosis of periodontitis could be overlooked due to certain limitations of the conventional diagnostic methods such as periodontal charting and radiographs. utilization of readily available biomarkers in the oral biofluids represents a potential opportunity to overcome these issues. this topic received great attention in the last decades and one of these biomarkers is matrix metalloproteinase 9 which is highlighted in this review as one of the candidates that can be used for diagnosis of periodontal diseases. keywords: matrix metalloproteinases, periodontal disease, periodontitis, diagnosis. introduction periodontitis is a multi-factorial chronic inflammatory disease characterized by destructive events to the supporting structures of the teeth. at the terminal stages of this disease, tooth loss is inevitable result with subsequent deterioration in function, esthetic, and quality of life (1, 2). the main etiological factor responsible for the initiation and progression of periodontitis is the dysbiotic biofilm leading to chain immune-inflammatory reactions which are further modified by genetic and environmental risk factors (3). periodontitis is one of the most prevalent chronic disease affecting humankind. statistics indicate that periodontitis of different severities affect up to 50% of the populations worldwide (4). this is associated with negative outcomes on different aspects of individual’s oral and systemic health and also exerting an economic burden in developed and developing countries (2). shifting of subgingival microbiota from symbiotic to dysbiotic biofilm is the keystone factor for triggering an intense immune response and inflammatory reaction responsible for the development and progression of periodontitis (5, 6). periodontitis-associated destructive events are characterized by upregulation of proand inflammatory cytokines and proteolytic enzymes responsible for damaging the periodontal tissues. for instance, mmp responsible for extracellular matrix remodeling during health; however, when their levels exceed the normal concentrations is an alarming sign of progressive periodontitis (7, 8). in addition, during health state, lytic action of mmps is normally regulated and neutralized by the tissue inhibitors of matrix metalloproteinases (timp) (9). on contrary, during periodontitis, available timp in the tissue is not enough to counteract excessively-produced mmps (10). received date: 15-3-2022 accepted date: 14-5-2022 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/jbcd .v34i2.3148 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i2.3148 https://doi.org/10.26477/jbcd.v34i2.3148 j. bagh. coll. dent. vol. 34, no. 2. 2022 atarchi 75 one of the main issues related to periodontitis is its early diagnosis by the general practitioners. this is related to certain drawbacks of the conventional diagnostic methods especially when the disease is in its early stages. over last decades, many researchers investigated the diagnostic potential of many biomarkers available in oral biofluids to use them as surrogates for diagnosis and prediction of periodontal diseases. this review aimed to highlight available evidence about the diagnostic power of matrix metalloproteinase (mmp)-9 to differentiate periodontal health and disease. diagnosis of periodontal disease, dilemma of periodontal parameters towards the end of 2017, joint workshops of american academy of periodontology and european federation of periodontology led to the announcement of the latest classification system for periodontal diseases and conditions. this novel scheme differs greatly from the older classification system issued in 1999 (11). although many issues related to the older system were solved by the new one, issues related to the conventional diagnostic methods still exist. among these problems is that clinical parameters measurements are highly dependent on the operator’s skills and experience. in addition, recording of periodontal parameters could be affected by periodontal probe dimensions, force of application, and direction of the probe (12-14). furthermore, full-mouth periodontal charting is a time-consuming and equally tedious process for the operator and the patient. moreover, radiographs are 2-dimensional images of 3-dimensional objects in which certain structures could be obscured or dimensionally distorted (12-14). however, despite these limitations, periapical radiograph is indispensable tool to detect interproximal bone loss particularly in early stages of periodontitis which is potentially missed during periodontal probing. indeed, correct diagnosis is essential step for tailoring solid treatment plan and predicting progression of periodontitis (15, 16). the aforementioned drawbacks of the clinical diagnostic methods necessities the seek for alternative, time-saving, cost-effective, and accurate diagnostic methods. salivary biomarkers are readily available and can be collected non-invasively could be the solution for reliable and quick screening of the patients using chairside techniques. matrix metalloproteinase 9 as a diagnostic tool for periodontal disease the mmp9 is one of the key proteolytic enzymes responsible for degrading collagen and gelatin in the extracellular matrix proteins during periodontal health and disease (17, 18). type iv collagen is the main target of mmp9, thereby, the action of this enzyme leads to disintegration of the basal membrane (19). in addition, mmp9 is also responsible for attracting osteoclasts to the site of bone resorption (20, 21, 22). indeed, these actions are more obvious during periodontitis when the concentrations of mmp9 increased beyond neutralizing action of timp (23). j. bagh. coll. dent. vol. 34, no. 2. 2022 atarchi 76 the fact that mmp9 alongside other inflammatory mediators/cytokines are significantly increased during periodontal disease as compared to health attracted the interest of investigators to use them as diagnostic biomarkers. available literature proposed that salivary mmp9 exhibits high accuracy to discriminate periodontal health from disease (24-27). search of literature showed limited number of publications which investigated mmp9, in different oral biofluids including saliva, as a diagnostic tool for periodontal disease (table 1). however, all these studies were observational and were conducted on a limited sample size. in addition, impact of real-life situations such as smoking and systemic diseases were not considered and their effect on the diagnostic potential of mmp9 still not clear. table 1: the diagnostic accuracy of salivary matrix metalloproteinase 9 as a biomarker for periodontal diseases. reference study population sample conclusions bostanci et al., 2021 (28) periodontitis, gingivitis, and healthy periodontium (n=127) wus combination of mmp9 with other biomarkers demonstrated high accuracy (up to 100%) to differentiate health from disease. kim et al., 2020 (29) periodontitis and healthy periodontium (n=137) wus mmp9 showed an accuracy of 82% to differentiate periodontitis from healthy periodntium kim et al., 2020 (30) periodontitis and healthy periodontium (n=149) wus salivary s100a8 and mmp9 showed high diagnostic/prognostic value for periodontitis. alassiri et al., 2018 (31) periodontitis, periimplantitis, healthy periodontium (n=80) oral rinse, pisf, gcf the tests are valid to differentiate periodontal and peri-implant health from disease whole unstimulated saliva (wus), peri-implant sulcular fluid (pisf), gingival crevicular fluid (gcf) conclusions available studies showed encouraging and promising results for using mmp9 to differentiate periodontal health from disease. however, the level of evidence cannot support the use of this enzyme as a diagnostic chairside tool as further controlled studies with higher standards are required before translating the results into clinical practice. conflict of interest: none. references 1. kinane df, stathopoulou pg and papapanou pn. periodontal diseases. nat rev dis primers. 2017;3:17038. j. bagh. coll. dent. vol. 34, no. 2. 2022 atarchi 77 2. botelho j, machado v, leira y, proença l, chambrone l and mendes jj. economic burden of periodontitis in the united states and europe: an updated estimation. j periodontol. 2022;93:373-379. 3. kornman ks. mapping the pathogenesis of periodontitis: a new look. j periodontol. 2008;79:1560-8. 4. nazir m, al-ansari a, al-khalifa k, alhareky m, gaffar b and almas k. global prevalence of periodontal disease and lack of its surveillance. scientificworldjournal. 2020;2020:2146160. 5. darveau rp. periodontitis: a polymicrobial disruption of host homeostasis. nat rev microbiol. 2010;8:481-90. 6. offenbacher s. periodontal diseases: pathogenesis. ann periodontol. 1996;1:821-78. 7. weng h, yan y, jin yh, meng xy, mo yy and zeng xt. matrix metalloproteinase gene polymorphisms and periodontitis susceptibility: a meta-analysis involving 6,162 individuals. sci rep. 2016;6:24812. 8. romanos ge and bernimoulin jp. [collagen as a basic element of the periodontium: immunohistochemical aspects in the human and animal. 1. gingiva and alveolar bone]. parodontol. 1990;1:363-75. 9. murphy g. tissue inhibitors of metalloproteinases. genome biol. 2011;12:233. 10. checchi v, maravic t, bellini p, generali l, consolo u, breschi l and mazzoni a. the role of matrix metalloproteinases in periodontal disease. int j environ res public health. 2020;17. 11. caton jg, armitage g, berglundh t, chapple ilc, jepsen s, kornman ks, mealey bl, papapanou pn, sanz m and tonetti ms. a new classification scheme for periodontal and peri-implant diseases and conditions introduction and key changes from the 1999 classification. j periodontol. 2018;89 suppl 1:s1-s8. 12. slots j. periodontitis: facts, fallacies and the future. periodontol 2000. 2017;75:7-23. 13. andrade r, espinoza m, gómez em, espinoza jr and cruz e. intraand inter-examiner reproducibility of manual probing depth. braz oral res. 2012;26:57-63. 14. lafzi a, mohammadi as, eskandari a and pourkhamneh s. assessment of intraand inter-examiner reproducibility of probing depth measurements with a manual periodontal probe. j dent res dent clin dent prospects. 2007;1:19-25. 15. papapanou pn, sanz m, buduneli n, dietrich t, feres m, fine dh, flemmig tf, garcia r, giannobile wv, graziani f, greenwell h, herrera d, kao rt, kebschull m, kinane df, kirkwood kl, kocher t, kornman ks, kumar ps, loos bg, machtei e, meng h, mombelli a, needleman i, offenbacher s, seymour gj, teles r and tonetti ms. periodontitis: consensus report of workgroup 2 of the 2017 world workshop on the classification of periodontal and peri-implant diseases and conditions. j periodontol. 2018;89 suppl 1:s173-s182. 16. shaddox lm and walker cb. treating chronic periodontitis: current status, challenges, and future directions. clin cosmet investig dent. 2010;2:79-91. 17. kim hd, sukhbaatar m, shin m, ahn yb and yoo ws. validation of periodontitis screening model using sociodemographic, systemic, and molecular information in a korean population. j periodontol. 2014;85:1676-83. j. bagh. coll. dent. vol. 34, no. 2. 2022 atarchi 78 18. chen q, jin m, yang f, zhu j, xiao q and zhang l. matrix metalloproteinases: inflammatory regulators of cell behaviors in vascular formation and remodeling. mediators inflamm. 2013;2013:928315. 19. jotwani r, eswaran sv, moonga s and cutler cw. mmp-9/timp-1 imbalance induced in human dendritic cells by porphyromonas gingivalis. fems immunol med microbiol. 2010;58:314-21. 20. xie r, kuijpers-jagtman am and maltha jc. osteoclast differentiation and recruitment during early stages of experimental tooth movement in rats. eur j oral sci. 2009;117:43-50. 21. somerville rp, oblander sa and apte ss. matrix metalloproteinases: old dogs with new tricks. genome biol. 2003;4:216. 22. delaissé jm, andersen tl, engsig mt, henriksen k, troen t and blavier l. matrix metalloproteinases (mmp) and cathepsin k contribute differently to osteoclastic activities. microsc res tech. 2003;61:504-13. 23. şurlin p, oprea b, solomon sm, popa sg, moţa m, mateescu go, rauten am, popescu dm, dragomir lp, puiu i, bogdan m and popescu mr. matrix metalloproteinase -7, -8, -9 and -13 in gingival tissue of patients with type 1 diabetes and periodontitis. rom j morphol embryol. 2014;55:1137-41. 24. kc s, wang xz and gallagher je. diagnostic sensitivity and specificity of host-derived salivary biomarkers in periodontal disease amongst adults: systematic review. j clin periodontol. 2020;47:289-308. 25. de morais ef, pinheiro jc, leite rb, santos ppa, barboza cag and freitas ra. matrix metalloproteinase-8 levels in periodontal disease patients: a systematic review. j periodontal res. 2018;53:156-163. 26. victor dj, subramanian s, gnana pp and kolagani sp. assessment of matrix metalloproteinases-8 and -9 in gingival crevicular fluid of smokers and non-smokers with chronic periodontitis using elisa. j int oral health. 2014;6:67-71. 27. saglam m, kantarci a, dundar n and hakki ss. clinical and biochemical effects of diode laser as an adjunct to nonsurgical treatment of chronic periodontitis: a randomized, controlled clinical trial. lasers med sci. 2014;29:37-46. 28. bostanci n, mitsakakis k, afacan b, bao k, johannsen b, baumgartner d, müller l, kotolová h, emingil g and karpíšek m. validation and verification of predictive salivary biomarkers for oral health. sci rep. 2021;11:6406. 29. kim h-d, lee c-s, cho h-j, jeon s, choi y-n, kim s, kim d, jin lee h, vu h, jeong h-j and kim b. diagnostic ability of salivary matrix metalloproteinase-9 lateral flow test point-of-care test for periodontitis. j clin periodontol. 2020;47:1354-1361. 30. kim. hd, kim s, jeon s, kim sj, cho hj and choi yn. diagnostic and prognostic ability of salivary mmp-9 and s100a8 for periodontitis. j clin periodontol. 2020;47:1191-1200. 31. alassiri s, parnanen p, rathnayake n, johannsen g, heikkinen am, lazzara r, van der schoor p, van der schoor jg, tervahartiala t, gieselmann d and sorsa t. the ability of quantitative, specific, and sensitive point-of-care/chairside oral fluid immunotests for ammp-8 to detect periodontal and peri-implant diseases. dis markers. 2018;2018:1306396. j. bagh. coll. dent. vol. 34, no. 2. 2022 atarchi 79 وأمراضها اللثة صحة بين للتمييز اللعابية matrix metalloproteinase 9 استخدام إمكانات رجي عط رمزي أحمد المستخلص السن دواعم التهاب عواقب تقتصر ال. حساس لمضيف اللثة تحت لميكروبات المناعية االستجابة تفاقم عن ينتج مزمن التهابي مرض هو السن دواعم التهاب أنحاء جميع في الصحية النظم على اقتصادية أعباء تفرض وأيًضا للفرد العامة الصحة على لتؤثر تمتد بل ، فحسب الفم تجويف على المدمر التأثير على أو المناسبة الوقائية التدابير مع المبكر التشخيص طريق عن تجنبها يمكن ، ذلك ومع ؛ السن دواعم اللتهاب الخطيرة النتائج هذه من الرغم على. العالم التشخيص العيوب المرتبطة بطرق بعض بسبب السن دواعم التهاب تشخيص ان يهمل يمكن ، سريريًا . المرض من مبكرة مراحل في الغازية غير التدخالت على للتغلب محتملة فرصة الفموية الحيوية السوائل في بسهولة المتاحة الحيوية المؤشرات استخدام يمثل. الشعاعي والتصوير اللثة مخططات مثل التقليدية تم والتي matrix metalloproteinase 9 هو الحيوية المؤشرات هذه وأحد الماضية العقود في كبير باهتمام الموضوع هذا حظي. المشكالت هذه .اللثة أمراض لتشخيص استخدامها يمكن الذين المرشحين كأحد المراجعة هذه في عليها الضوء تسليط 21hussain f.docx j bagh college dentistry vol. 28(3), september 2016 assessment of alkaline oral and maxillofacial surgery and periodontics 125 assessment of alkaline phosphatase, salivary flow rate and salivary potential of hydrogen in relation to severity of chronic periodontitis hussein a. mousa, b.d.s. (1) saif s. saliem, b.d.s., m.sc. (2) abstract background: the cells of periodontium contain many intracellular enzymes like (alkaline phosphatase alp) that are released outside into the saliva and gingival crevicular fluid (gcf) after destruction of periodontal tissue. the aim of study was to determine the activity of this enzyme in saliva and its relation to the salivary flow rate, ph and clinical periodontal parameters in patients with chronic periodontitis. subject, materials and methods: sample population consist of 75 individuals ;divided into four groups , the first group (15):control subject, the second group (20):mild chronic periodontitis, the third group(20) moderate chronic periodontitis and the fourth group (20) sever chronic periodontitis, measurements of plaque index (pli), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal), only male were included and saliva was collected from them and subjected to biochemical analysis of the alkaline phosphatase enzyme (alp), and also measurement of salivary flow rate(fr) and ph. results: statistical analysis of the results revealed the presence of a highly significant difference in the enzymatic activity between healthy and chronic periodontitis subjects (mild, moderate, severe) with positive correlation between the activity of this enzyme and the clinical periodontal parameters, and negative correlation between this enzyme and salivary flow rate and ph. conclusion: from this study it can be concluded that a number of markers show promise as sensitive measures of disease and the effectiveness of therapy. at this time enzymes such as alkaline phosphatase alp, is good biochemical markers of screening chronic periodontitis. also alp can be used as a monitor for healthy individuals and patients with different periodontal diseases. furthermore, analysis of saliva may offer a cost effective approach to assessment in controlling progression of chronic periodontitis in large populations. keyword: chronic periodontitis, saliva, flow rate, alkaline phosphatase. (j bagh coll dentistry 2016; 28(3):125-131). introduction periodontal disease (pd) is one of the common inflammatory diseases within complex etiology and multifactorial in origin. diagnosis of periodontal disease depended on clinical and radiographic measures of periodontal tissue destruction. these parameters provide measures of past destruction and are of limited use in early diagnosis (1).genetics and molecular biology in advances stage lead to a better knowledge of the pathways and mechanisms through which microorganism maintain the host immune/inflammatory response (2). chronic periodontitis (cp) is very common disease (3)and it is a slowly progressing form of pd, but may have periods of rapid progression (4). saliva is an important biological material that got in new diagnostic tests which may contribute in the diagnosis and explaining the pathogenesis of some diseases (5). saliva plays an important role in discovery of periodontal disease because it is easily collected and allows analysis of several biological markers such as proteins, enzymes, host cells, hormones, and bacterial products; therefore, no specific laboratory devices are necessary and this approach may be suitable for public health use(6). (1) master student. department of periodontics, college of dentistry, university of baghdad (2) assistant professor, department of periodontics, college of dentistry, university of baghdad. the amount of saliva naturally produced by the salivary glands is called salivary flow rate. production of saliva is increased by the presence of food or irritating substances, such as vomit, in the oral cavity (7). mean daily saliva production for healthy person ranges from 1 to 1.5l (8).the salivary flow index is a parameter allowing stimulated and unstimulated saliva flow to be classified as normal, low, or very low (hyposalivation) (9). normal total stimulated salivary flow rate (fr) ranges from up to 3 ml/ min. a measure of the acidity or alkalinity of a solution, is defined salivary ph, the normal ph range for saliva is considered to be 5.6 to 7.9, depend on international journal of drug testing's above 7 scale usually indicate alkalinity and when below 7 scale indicate acidity (10). alkaline phosphatase (alp) is hydrolase enzyme responsible for removing phosphate groups from many of types of molecules, including nucleotides, proteins, and alkaloids. the process of removing phosphate group is called dephosphorlation, alp is effective in an alkaline environment(11). this enzyme is an important indicator of bone formation and considered as marker for osteoblast cells. alp was detected inthe parotid, submandibular and minor salivary glands (12). j bagh college dentistry vol. 28(3), september 2016 assessment of alkaline oral and maxillofacial surgery and periodontics 126 materials and methods the sample consisted of 75 patients, subjects' collection from the department of periodontics, at teaching hospital, college of dentistry, university of baghdad as well as from blood bank. all subject enrolled voluntarily in the study after a well explanation about the aim and purposes of the study and gave informed consent to participate in the study. the subjects were divided into four groups according to american academy of periodontology 1999(13). 1control group i (healthy periodontium): consisted of fifteen (15) apparently systemically healthy without history of any systemic disease and with healthy periodontium, this was defined by gi scores <0.5 (14).and without periodontal pockets or clinical attachment loss. 2-study group ii (mild chronic periodontitis): consisted of twenty (20)patients, in which mild clinical attachment loss of (1-2 mm). 3-study groupiii(moderate chronic periodontitis):consistedof twenty (20)patients, in which attachment loss up to (3-4 mm). 4study groupiv(severe chronic periodontitis): consisted of twenty (20)patients, in which attachment loss (5 mm) or more. exclusion criteria: 1patients who have undergone periodontal treatment in the 3 month period prior to the study. 2a course of anti-inflammatory or antimicrobial therapy during the last (3 months). 3smoking or alcohol drinking clinical periodontal parameter examination: 1-assessment of plaque index system (pli): this was done by using plaque index system which was introduced by silness (15). 2-assessment of gingival inflammation by the gingival index system (gi): this was assessed using the criteria of the gingival index system that modified by löe(14). 3assessment of gingival bleeding on probing (bop): if bleeding occurs within 30 seconds the site was given a positive score (1) and a negative score (0) for the non –bleeding site(16). 4-assessment of probing pocket depth (ppd): this is defined as the distance from gingival margin to the most apical penetration of the periodontal probe inserted into the gingival crevice or pocket without force or pressure 5-assessment of clinical attachment level (cal): it is defined as the distance from the cementoenamel junction (cej) to the location of the inserted probe tip (bottom of gingival crevice or pocket). measurement of salivary flow rate and ph: the volume of unstimulated saliva that collected firstly from each subject at 5 min was recorded; through using graduated syringes, the saliva collected firstly was aspirated from the collection receptacle with a disposable 5 ml sterile syringe avoiding contact with the epithelium. the amount of saliva in ml, divided by the time of duration of the collection was recorded as the mean salivary flow rate. only the liquid component of the saliva, not the foam, was measured. where estimation of flow rate (ml/min) was made according to this equation: flow rate (fr): volume (ml) / time (min)﴿ . samples containing blood were discarded. the samples were put in a small cooling box after collection to stop bacterial growth. the tube was labeled with the number of the subject corresponding to that written previously on the case sheet. the salivary ph was measured by using the (dp universal test paper) by immersing the strip into the saliva for about 2 seconds, then waited for color changes for 15 seconds and compared to the color chart present on the plastic case of the product. biochemical analysis: alkaline phosphatase (alp) enzyme: for alp enzyme analysis we used kit manufactured by (biomereiux ®sa) which is one of the french leaders of reagents (r) for medical biochemistry, all the kits used for enzymes analysis subjected to modification by a specialist (biochemist) in the laboratories of the poisons center to measure the activity of these enzymes in saliva. principle: according to biomérieux kit for alkaline phosphatase enzyme. colorimetric determination of alp activity according to the following reaction: phenyl phosphate alp phenol + phosphate the liberated phenol is measured in the presence of 4-aminoantipyrine and potassium ferricyanide. the presence of sodium arsenate in the reagent stops the enzymatic reaction. stastistical analyses a) one-way anova test: to compare the measured variables among the groups. b) lsd test: to test any statistically significant difference between each two groups. c) pearson's correlation coefficient test (r): to test the relation between alp and other j bagh college dentistry vol. 28(3), september 2016 assessment of alkaline oral and maxillofacial surgery and periodontics 127 clinical periodontal parameter and the measured variables in each group. results the current results revealed that mean values of (pli, gi, bop, ppd and cal)were higher in severe group than other groups, while the mean values of the (fr, ph)were higher in control than other groups and the mean value of (alp) was higher in sever group than other groups, these results show in table1and 2. table 1: descriptive and inferential statistics of pli, gi, bop, ppd and cal parameter for allstudy groups table 2:descriptive and inferential statistics of fr, ph and alp parameter for control and study groups variables groups descriptive statistics comparison (d.f. =74) n mean s.d. min. max. f-test p-value fr control 15 1.38 0.11 1.2 1.5 429.54 0.000 (hs) mild 20 0.87 0.04 0.8 0.9 moderate 20 0.67 0.04 0.6 0.7 severe 20 0.38 0.12 0.2 0.5 ph control 15 7 0 7 7 318.996 0.000 (hs) mild 20 5.6 0.5 5 6 moderate 20 4.30 0.47 4 5 severe 20 2.65 0.49 2 3 alp control 15 23.57 1.28 21.22 25.05 695.31 0.000 (hs) mild 20 74.40 9.50 60.25 89.38 moderate 20 98.32 5.32 91.20 107.04 severe 20 119.23 5.76 109.41 131.62 inter-groups comparisons by least significant difference (lsd) test for testing equality of variances illustrated in the table (3, 4), the statistical analysis using the lsdtest to compare mean values of (pi, gi, bop, ppd, cal),(alp, fr, ph) between study groups, revealed highly significant differences at p<0.01 . variables groups descriptive statistics comparison (d.f. =74) n mean s.d. min. max. f-test p-value pli control 15 0.46 0.07 0.312 0.592 2532.23 0.000 (hs) mild 20 1.79 0.05 1.7 1.875 moderate 20 2.05 0.08 1.89 2.19 severe 20 2.59 0.08 2.44 2.699 gi control 15 0.35 0.06 0.25 0.454 2804.19 0.000 (hs) mild 20 1.70 0.05 1.61 1.77 moderate 20 1.97 0.07 1.873 2.091 severe 20 2.49 0.09 2.3 2.592 bop mild 20 34.17 4.23 25 37.5 1657.135 0.000 (hs) moderate 20 59.95 2.65 56.25 63 severe 20 87.28 0.80 85.9 88 ppd mild 20 0.60 0.07 0.5 0.75 7633.961 0.000 (hs) moderate 20 2.42 0.13 2.25 2.735 severe 20 5.10 0.13 4.875 5.318 cal mild 20 1.60 0.09 1.362 1.76 5985.466 0.000 (hs) moderate 20 3.41 0.15 3.11 3.771 severe 20 6.50 0.17 6.096 6.767 j bagh college dentistry vol. 28(3), september 2016 assessment of alkaline oral and maxillofacial surgery and periodontics 128 table 3: inter-groups comparisons of mean value of pli, gi, bop, ppd and cal parameter between study groups variables groups mean difference p-value pl mild moderate -0.26 0.000 (hs) severe -0.80 0.000 (hs) moderate severe -0.54 0.000 (hs) gi mild moderate -0.27 0.000 (hs) severe -0.79 0.000 (hs) moderate severe -0.51 0.000 (hs) bop mild moderate -25.79 0.000 (hs) severe -53.12 0.000 (hs) moderate severe -27.33 0.000 (hs) ppd mild moderate -1.82 0.000 (hs) severe -4.50 0.000 (hs) moderate severe -2.68 0.000 (hs) cal mild moderate -1.81 0.000 (hs) severe -4.90 0.000 (hs) moderate severe -3.09 0.000 (hs) table 4: inter-groups comparisons of mean value of ph, fr, and alp parameter between all four groups variables groups mean difference p-value ph control mild 1.4 0.000 (hs) moderate 2.7 0.000 (hs) severe 4.35 0.000 (hs) mild moderate 1.3 0.000 (hs) severe 2.95 0.000 (hs) moderate severe 1.65 0.000 (hs) fr control mild 0.51 0.000 (hs) moderate 0.71 0.000 (hs) severe 1 0.000 (hs) mild moderate 0.20 0.000 (hs) severe 0.49 0.000 (hs) moderate severe 0.29 0.000 (hs) alp control mild -50.83 0.000 (hs) moderate -74.75 0.000 (hs) severe -95.66 0.000 (hs) mild moderate -23.92 0.000 (hs) severe -44.83 0.000 (hs) moderate severe -20.90 0.000 (hs) regarding the correlation coefficient between level of alp enzyme and pli, gi parameters for control group strong highly-significant positive correlation was found, while with salivary fr, it showed a strong highly -significant negative correlation, these results were demonstrated in table (5). table 5: pearson’s correlation coefficient (r) between alp and pl, gi, fr and ph of the control group variables pi gi fr ph alp r 0.903 0.930 -0.970 p-value 0.000 0.000 0.000 the results of correlation coefficient between pli, gi, bop, ppd, cal parameters and level of the alp enzyme for mild group, revealed a strong highly-significant positive correlation.the results between fr, ph parameters and alp, revealed a strong highly-significant negative correlation. these results were demonstrated in table (6). j bagh college dentistry vol. 28(3), september 2016 assessment of alkaline oral and maxillofacial surgery and periodontics 129 table 6:pearson’s correlation coefficient (r) between clinical periodontal parameters (pli, gi, bop, ppd, cal) and biochemical parameters(alp) with frandphof themild group. variables pi gi bop ppd cal fr ph alp r 0.682 0.694 0.774 0.704 0.708 -0.814 -0.779 p-value 0.001 0.001 0.000 0.001 0.001 0.000 0.000 regarding the correlation coefficient between pli, gi, bop, ppd, cal parameters and level of the alp for moderate group, the results revealed a strong highly-significant positive correlation. the results of correlation coefficient between fr, ph parameter and alp, revealed a strong highlysignificant negative correlation, these results were demonstrated in table (7). table 7: pearson’s correlation coefficient (r) between clinical periodontal parameters (pli, gi, bop, ppd, cal) and biochemical parameters (alp) with salivary flow rate of the moderate group. variables pi gi bop ppd cal fr ph alp r 0.956 0.892 0.981 0.951 0.928 -0.846 -0.784 p-value 0.000 0.000 0.000 0.000 0.000 0.000 0.000 the results of correlation coefficient between pli, gi, bop, ppd, cal parameters and level of the alp for severe group, revealed a strong highly-significant positive correlation. the result between fr, ph parameters and alp, showed a strong highly-significant negative correlation, these results were demonstrated in table (8). table 8: pearson’s correlation coefficient (r) between clinical periodontal parameters (pli, gi, bop, ppd, cal) and biochemical parameters (alp) with salivary flow rate of thesevere group. variables pi gi bop ppd cal fr ph alp r 0.965 0.937 0.780 0.969 0.957 -0.838 -0.701 p-value 0.000 0.000 0.000 0.000 0.000 0.000 0.001 discussion the findings of the study that a highly significant difference in pli, gi,bop, ppd, cal between the study and control groups, these findings were due to increase in the bacterial invasion and the amount of plaque that caused destruction of the sulcular and junctional epithelium and surrounding alveolar bone. this findings revealed that the level of alkaline phosphatase alp in the study group higher than control groups these results were in agreement with nakamura(17).also accordance with many studies (18,19). the explanation for this difference in the enzyme activity between the two groups may be due to the fact that alp is present at or near the cell membrane of alveolar bone osteoblasts and fibroblasts of the periodontal ligaments (2022).during the active stages of periodontitis, there will be destruction of alveolar bone osteoblasts and fibroblasts and their cell membrane will be ruptured releasing their intracellular contents outside. so alp will be released into saliva and gcf and the level of alp will increase in saliva (6,23,24). in the present study there was statistically high-significant differences in unstimulated salivary flow rate among either groups(25) indicate that periodontitis induces an increase in the output of proteins, thereby enhancing the protective potential of saliva, but this is accompanied by a decrease in flow rate. but disagree with fiyaz(26) who found that individuals who have increased salivary inorganic calcium, phosphate, ph, fr and maintain poor oral hygiene could be at ahigher risk for developing periodontitis and may have less dental caries and more number of intact teeth. the findings of the study showed that there was a highly-significant difference in term of salivary ph, between study and control groups, baliga (27) observed that there is a correlation between ph of saliva and periodontal diseases when compared with healthy groups. salivary ph in patients with chronic generalized periodontitis is more acidic than the control group, increase acidity (ph below 7) as the increasing severity of periodontal condition. this results revealed that a strong highlysignificant positive correlation between alp and pl, gi index in control group, also between alp j bagh college dentistry vol. 28(3), september 2016 assessment of alkaline oral and maxillofacial surgery and periodontics 130 and pl, gi, bop, ppd, cal indices in mild, moderate and severe groups respectively. the explanation for this result is that alp produced by many cells such as pmnls during inflammation, from osteoblasts (28) and pdl fibroblasts (29)during bone formation and periodontal regeneration respectively, the usual immunological response to dental plaque pathogens and alveolar bone destruction makes the alp concentration correlated positively with clinical periodontal parameters. this result agreed with other studies, the findings of todorovic (30) showed a high coefficient of correlation between the values of gi and the activities of these enzymes. number of previous studies disagreed with our results, these findings in herasaki (31). as they found that there was no correlation between alp and pli, gi parameter. the findings of the study were faced by ray (32). who stated that there was no correlation between the enzymatic activity of alp and bop. this result stated that there was correlation between the activities of these enzymes and ppd and cal, these findings were not supported by herasaki (31).on the other side, the study of ray (32) concluded that alp had a significant correlation with ppd and cal. also our results revealed that a strong highlysignificant negative correlation between alp with fr in control, mild, moderate, severe groups (25) indicate that periodontitis induces an increase in the output of proteins, thereby enhancing the protective potential of saliva, but this is accompanied by a decrease in flow rate (increasing severity the inflammation lead to highly protein concentration lead to decrease salivary flow rate). also this result revealed that a strong highlysignificant negative correlation between alp with ph in mild, moderate, severe groups (27) observed that there is a correlation between ph of saliva and periodontal diseases when compared with healthy groups. salivary ph in patients with chronic generalized periodontitis is more acidic than the control group, increase acidity (ph below 7) as the increasing severity periodontal condition. references 1. haffajee ad, secransky ss, goodson jm. clinical parameters of predictors of destructive periodontal disease activity. j clin periodontal 1983;10: 257-65. 2. socransky ss, haffajee ad. dental biofilms: difficult 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bagh college dentistry vol. 28(3), september 2016 assessment of alkaline oral and maxillofacial surgery and periodontics 131 phosphate, ph and flow rate on oral health: a study on 90 subjects. j indian socperiodontol2013; 17:454-60. 27. baliga s, muglikar s, kale r. salivary ph: a diagnostic biomarker. j indian socperiodontol2013; 17: 461-5. 28. christenson, rh. biochemical markers of bone metabolism: an overview. clinical biochem1997; 30: 573–93. 29. groeneveld mc, van den bos t, everts v, beertsen w. cell-bound and extracellular matrix associated alkaline phosphatase activity in rat periodontal ligament. experimental oral biology group. j periodontal res1996; 31: 73-9. 30. todorovic t, dozic i, vicente-barrero m, ljuskovic b, pejovic j, marjanovic m, knezevic m. salivary enzymes and periodontal disease. med oral patol oral cir bucal2005; 11: 115-9. 31. herasaki s, yamazaki t, shipa k. changes in salivary components by drug administration in patients with heart diseases. j med sci 2005; 52: 183-8. 32. ray b, kharb s, anand sc. salivary enzymes and thiocynate: salivary markers of periodontitis among smokers and non-smokers; a pilot study. advances in medical and dental sci2007; 1(1): 1-4. j bagh college dentistry vol. 29(1), march 2017 buccal cortical bone pedodontics, orthodontics and preventive dentistry 183 buccal cortical bone thickness in iraqi arab adults by cone beam computed tomography for orthodontic mini-implants saad a. abbas, b.d.s., m.sc. (1) akram f. alhuwaizi, b.d.s., m.sc., ph.d. (2) abstract background: cortical bone thickness is important for the stability of mini implants. placing mini implants in sites of favorable cortical bone thickness would guarantee better initial stability and long-term success. the aim of this study was to investigate gender, side and jaw differences of the buccal cortical bone thickness as a guide for orthodontic mini screw placement. materials and methods: the sample was selected from the patients attending the specialized health center in alsadr city / 3d department. thirty patients (15 males and 15 females) were selected and cone beam computerized tomographic images were done. then the buccal cortical bone thickness was measured at thirteen inter radicular sites in the maxilla and mandible from the mesial side of the second molar to the mesial side of the second molar on the other side. the resulting data were statistically analyzed using independent t-test on spss program. results: the buccal cortical bone thickness of the males was more than the females for both jaws. the mandibular buccal cortical bone thickness was thicker than in the maxillary and in the anterior region was thinner than in the posterior region for each jaw. the thickness of the buccal cortical bone was generally greater on the left side. keywords: mini-implant, cortical bone thickness, bone quality. (j bagh coll dentistry 2017; 29(1):183-187) introduction provision of anchorage is one of the most challenging aspects of orthodontic treatment planning. routine and conventional anchorage techniques are generally dependent on patient compliance and usually result in untoward reciprocal tooth movements. to overcome such a problem, orthodontic mini-implants have been incorporated into orthodontic treatment techniques. adequate bone at mini-implant placement site can affect the success or failure of anchorage; therefore, a large number of studies have been carried out to determine appropriate locations for and stability of mini-implants. it is necessary to have knowledge about the thickness of bone to select a proper length for mini-implants to avoid perforation of the nasal cavity. in addition, knowledge about bone thickness is useful for the determination of the length of miniimplants and the height of mini-implant neck.(1-9) recent studies showed that factors related to the stability of mini-implant included: the cortical bone quality and quantity, soft tissue inflammation around the mini-implant, interradicular space, the design of the mini-implant as well as surgical insertion techniques. (10-14) motoyoshi recommended that a cortical bone thickness of 1.0 mm or more was the critical value of cortical bone thickness for the success of miniimplants implantation (15,16). therefore, the (1) orthodontist, sumar specialized dental center, ministry of health. (2) professor. department of orthodontics. college of dentistry, university of baghdad. cortical bone thickness is very important for the stability of mini-implants (15-19) in recent years, cbct technique has been used to place mini-implants accurately because the technique provides high-resolution images with less patient radiation or comparable to that of the ct technique. (20-23) materials and methods the sample in the specialized health center of al-sadr city, 351 patients referred to the 3d department for the diagnosis of various dental problems from december 2014 till may 2015 were examined. thirty iraqi arab adults (15 males and 15 females) were selected being 18-25 years of age with a full set of permanent teeth regardless of third molar, bilateral class i molar and canine relationships, normal overjet and overbite (24), well-aligned arches or mild crowding or spacing less than 3mm, periodontally healthy dentition and no history of orthodontic treatment. the method the subjects and their parents were informed about the study and consent to participate in it. preparing and positioning the patient was done according to the operator manual of the cbct machine (kodak 9500 3d). images were taken at 90 kv and 10 ma with a scanning time of 10.8s and voxel size 300. the data then was imported and saved on the main computer after acquisition. j bagh college dentistry vol. 29(1), march 2017 buccal cortical bone pedodontics, orthodontics and preventive dentistry 184 the acquisitioned images are axial or transverse images (coronal and sagittal images) in addition to 3d image. all these images are reconstructed by the 'kodak dental imaging software' with different types of slicing techniques (orthogonal, curved, custom and oblique slicing). for each point to be measured, the area of interest is assessed by using the same software. then “curved slicing” is chosen from the menu bar of the software window and four views appear in the screen (panoramic, axial, cross-sectional and 3d views). then the panoramic view was maximized and by using the vertical blue line the site is determined (fig. 1). before measuring the alveolar cortical bone thickness, each site was oriented in all view windows. the panoramic and axial views were used to locate the interradicular area of interest while the cross-section image (perpendicular to the panoramic curve) was used to select four areas at 2, 4, 6 and 8 mm from the alveolar crest by using the tools menu of the software to do the measurement. then the buccal cortical bone thickness was measured in the maxilla and mandible at thirteen interradicular sites from the mesial side of right second molar to the mesial side of left second molar.(25) statistical analysis the statistical package for social science (spss) was used for statistical analysis. independent t-test was used for comparing buccal cortical bone thickness between males and females, right and left sides and between the maxilla and mandible. p values of less than 0.05 were considered as statistically significant. results the mean buccal cortical bone thickness ranged between 1.247mm in the female maxillary anterior region at 4mm from the alveolar crest to 3.087mm in the male mandibular posterior region at 8mm from the alveolar crest. the buccal cortical bone thickness in males was significantly greater than in females in both jaws at 4, 6 and 8mm from the alveolar crest, but not significant at 2mm form the alveolar crest (fig. 2). mandibular measurements were statistically significantly (p<0.01) higher than those of the maxilla for both males and females, on both right and left sides at 2, 4, 6 and 8mm from the alveolar crest. the thickness of the buccal cortical bone was greater on the left side of male and female mandibles and female maxillae, but there was no clear pattern in male maxillae. however, all these differences were statistically non-significance (fig. 3). discussion the thicker buccal cortical bone thickness found in males was consistent with the findings of ono et al. (26), but contrary to those of deguchi et al. (27). this may be due to differences in sampling and measurement methods taken by deguchi et al. (27) who had a sample consisting of only five males and five females with different malocclusions and the thickness of cortical bone was evaluated at two levels only (3-4mm and 67mm from the alveolar crest) and in the posterior region only. figure 1: site assessment technique. j bagh college dentistry vol. 29(1), march 2017 buccal cortical bone pedodontics, orthodontics and preventive dentistry 185 figure 1: the buccal cortical bone thickness of the maxilla and mandible for males and females at 2, 4, 6 and 8mm from the alveolar crest. figure 2: the height of the buccal cortical bone thickness in the maxilla and mandible for males and females at different sites from the alveolar crest. the thicker cortical bone in the mandible was consistent with the results of many studies (26-30). the mandibular cortical bone thickness tends to increase with increasing distance away from the alveolar crest which also agrees with the findings of several studies (26,28-30). in the maxilla, the buccal cortical bone thickness mesial to the first premolars was found to increase with increasing distance from the alveolar crest. this was consistent with the finding reported by hong et al. (30) and baumgaertel and hans (28). the buccal cortical bone was thin in the anterior regions of both jaws and increased gradually toward the posterior region. these results agree with those found by baumgaertel and hans (28). it is found that not only the thickness of buccal cortical bone was thin in the anterior region but also the attached gingiva was short and insufficient interradicular distance, so j bagh college dentistry vol. 29(1), march 2017 buccal cortical bone pedodontics, orthodontics and preventive dentistry 186 for these reasons implanted miniscrews at the anterior part of both jaws should be cautioned (27,29,31). the mandibular cortical bone was thicker on the left sides than on the right sides but these differences did not reach statistical significance. this was consistent with the findings of the studies reported by ono et al. (26) and hong et al. (30) this result confirms the clinical study which stated that mini implants in the right side of the lower arch reveal a higher failure rate than those in the left side, may be because most people chew more frequently on the right side than the left side, which result in more force applied to the implant and that people brush better on the left side (32). in the maxilla, the present study showed no significant differences between the right and left sides of cortical bone thickness in males and females which was consistent with findings of the studies reported by lim et al. (31) and ono et al. (26) but inconsistent with the findings of another study reported by hong et al. (30) who found a significant difference between the right and left sides of maxilla at 4 and 8 mm from the alveolar crest only. this may be attributed to ethnic differences as hong et al. (30) examined 32 chinese subjects with age between 21-44 years. clinical considerations based on findings of this study, the following clinical considerations can be drawn: 1. the buccal cortical bone in the anterior region is thin in both jaws, so the use of mini-implant with large diameter is preferred to insure better primary stability and long term success. 2. the thickest buccal cortical bone was at 4 and 6mm from the alveolar crest in the maxilla and at 6 and 8mm in the mandible, so these sites are more suitable for mini-implant placement. 3. the mandibular posterior buccal cortical bone was the thickest site, so the use of short miniimplant may give sufficient stability. references 1. bernhart t, freudenthaler j, dortbudak o, bantleon hp, watzek g. short epithetic implants for orthodontic anchorage in the paramedian region of the palate. a clinical study. clin oral implants res 2001; 12: 624-31. 2. melsen b. palatal growth studied on human autopsy material. a histologic microradiographic study. am j orthod 1975; 68: 42-54. 3. revelo b, fishman ls. maturational evaluation of ossification of the midpalatal suture. am j orthod dentofacial orthop 1994; 105: 288-92. 4. schlegel ka, kinner f, schlegel kd. the anatomic basis for palatal implants in orthodontics. int j adult orthod orthognath surg 2002; 17: 133-9. 5. wehrbein h, merz br, diedrich p, glatzmaier j. the use of palatal implants for orthodontic anchorage. design and clinical application of the orthosystem. clin oral implants res 1996; 7: 410-6. 6. kang s, lee sj, ahn sj, heo ms, kim tw. bone thickness of the palate for orthodontic mini-implant anchorage in adults. am j orthod dentofacial orthop 2007; 131(suppl): s74-81. 7. gracco a, lombardo l, cozzani m, siciliani g. quantitative cone beam computed tomography evaluation of palatal bone thickness for orthodontic mini-implant placement. am j orthod dentofacial orthop 2008; 134: 361-9. 8. gracco a, lombardo l, cozzani m, siciliani g. quantitative evaluation with cbct of palatal bone thickness in growing patients. prog orthod 2006; 7: 164-74. 9. tosun t, keles a, erverdi n. method for the placement of palatal implants. int j oral maxillofac implants 2002; 17: 95-100. 10. meredith n. assessment of implant stability as a prognostic determinant. int j prosthodont 1998; 11: 491-501. 11. szmukler-moncler s, salamam h, reingewirtz y, dubruille jh. timing of loading and effect of micromotion on bone-implant interface: review of experimental literature. j biomed mater res 1998; 43: 192-203. 12. friberg b, sennerby l, meredith n, lekholm u. a comparison between cutting torque and resonance frequency measurements of maxillary implants: a 20month clinical study. int j oral maxillofac surg 1999; 28: 297-303. 13. ottoni jm, oliveira zf, mansini r, overgaard s, bu¨nger c. correlation between placement torque and survival of single-tooth implants. int j oral maxillofac implants 2005; 20: 769–76. 14. zhao l, xu z, yang z, wei x, tang t, zhao z. orthodontic mini-implant stability in different healing times before loading: a microscopic computerized tomographic and biomechanical analysis. oral surg oral med oral pathol oral radiol endod 2009; 108: 196–202. 15. motoyoshi m, inaba m, ono s, ueno s, shimizu n. the effect of cortical bone thickness on the stability of orthodontic mini-implants and on the stress distribution in surrounding bone. int j oral maxillofac surg 2009; 38(1): 13-8. 16. motoyoshi m, yoshida t, ono a, shimizu n. effect of cortical bone thickness and implant placement torque on stability of orthodontic mini-implants. int j oral maxillofac implants 2007; 22(5): 779-846. 17. motoyoshi m, ueno s, okazaki k, shimizu n. bone stress for a mini-implant close to the roots of adjacent teeth--3d finite element analysis. int j oral maxillofac surg 2009; 38(4): 363-8. 18. wilmes b, rademacher c, olthoff g, drescher d. parameters affecting primary stability of orthodontic mini-implants. j orofac orthop 2006; 67(3):162-74. 19. poggio pm, incorvati c, velo s, carano a. "safe zones": a guide for miniscrew positioning in the maxillary and mandibular arch. angle orthod 2006; 76:191-7. j bagh college dentistry vol. 29(1), march 2017 buccal cortical bone pedodontics, orthodontics and preventive dentistry 187 20. mah j, hatcher d. current status and future needs in craniofacial imaging. orthod craniofac res 2003; 6 suppl 1: 10-6. 21. mah jk, danforth ra, bumann a, hatcher d. radiation absorbed in maxillofacial imaging with a new dental computed tomography device. oral surg oral med oral pathol oral radiol endod 2003; 96: 508-13. 22. ludlow jb, davies-ludlow le, brooks sl. dosimetry of two extraoral direct digital imaging devices: new tom cone beam ct and orthophos plus ds panoramic unit. dentomaxillofac radiol 2003; 32: 229-34. 23. song je, um yj, kim cs, choi sh, cho ks, kim ck, chai jk, jung uw. thickness of posterior palatal masticatory mucosa: the use of computerized tomography. j periodontol 2008; 79: 406-12. 24. akram f. alhuwaizi. normal iraqi values of overjet and overbite. j bagh coll dentistry 2005; 17(3): 903. 25. cassetta m, sofan aaa, altieri f, barbato e. evaluation of alveolar cortical bone thickness and density for orthodontic mini-implant placement. j clin exp dent 2013; 5(5): e245-52. 26. ono a, motoyoshi m, shimizu n. cortical bone thickness in the buccal posterior region for orthodontic mini-implants. int j oral maxillofac surg 2008; 37(4): 334-40. 27. deguchi t, nasu m, murakami k, yabuuchi t, kamioka h, takano-yamamoto t. quantitative evaluation of cortical bone thickness with computed tomographic scanning for orthodontic implants. am j orthod dentofacial orthop 2006; 129(6): 721. e7-12. 28. baumgaertel s, hans mg. buccal cortical bone thickness for mini-implant placement. am j orthod dentofacial orthop 2009; 136(2): 230-5. 29. lee lk, joo e, kim kd, lee js, park yc, yu hs. computed tomographic analysis of tooth-bearing alveolar bone for orthodontic miniscrew placement. am j orthod dentofacial orthop 2009; 135(4): 48694. 30. hong zhao, xiao-ming gu, hong-chen liu, wang zw, xun cl. measurement of cortical bone thickness in adults by cone-beam computerized tomography for orthodontic mini screws placement 2013; 33(2): 303-8. 31. lim je, lim wh, chun ys. quantitative evaluation of cortical bone thickness and root proximity at maxillary interradicular sites for orthodontic miniimplant placement. clin anat 2008; 21(6): 486-91. 32. park hs, jeong sh, kwon ow. factors affecting the clinical success of screw implants used as orthodontic anchorage. am j orthod dentofacial orthop 2006; 130(1): 18-25. الخالصة ضل ونجاح سمك العظم الشدقي القشري مهم من اجل ثبات الزرعات التقويمية. تثبيت الزرعات التقويمية في أماكن ذات عظم سميك يؤمن ثبات ابتدائي أف :الخلفية من اجل وضع وعلى الجانبين األيمن واأليسر سنان في الفكين العلوي والسفلياأل ما بينيم سمك العظم الشدقي القشري وهو تق الدراسةالهدف من هذه بعيد األمد. .التقويميةالزرعات لثالثون مراجع ةشعاعي ةصورتم اخذ شعبة األشعة ثالثية األبعاد. –تم اختيار العينة من مراجعي المركز الصحي التخصصي في مدينة الصدر المواد والطرق: موقع بين 51في وبعد ذلك تم قياس سمك العظم القشري للفكين بالغيين يمتلكون اطباق طبيعي الشخاصالتصوير المقطعي المخروطي بجهازانثى( 51ذكرا و 51) .ومن ثم تم تحليل النتائج احصائيااألسنان في هما وكذلك اسمكالعلوي وفي مؤخرة الفكين العلوي والسفلي من مقدمتالسفلي من في الفك من االناث وفي الذكور سمكأالعظم الشدقي القشري كانالنتائج: .يمنيسر من الجانب األالجانب األ muntasir final.doc j bagh college dentistry vol. 26(3), september 2014 effect of three orthodontics, pedodontics and preventive dentistry 149 effects of three different types of intracoronal bleaching agents on shear bond strength of stainless steel and sapphire brackets bonded to endodontically treated teeth (an in vitro study) muntasser r. abdulkareem b.d.s. (1) ausama a. al-mulla b.d.s., dr.d.sc. (2) abstract background: evaluate the effects of three different intracoronal bleaching agents on the shear bond strengths (sbs) and failure site of stainless steel and monocrystalline (sapphire) orthodontic brackets bonded to endodontically treated teeth using light cured orthodontic adhesive in vitro. materials and methods: eighty extracted sound human upper first premolars were selected, endondontically treated and randomly divided equally (according to the type of the brackets used) into two main groups (n = 40 per group). each main group were subdivided (according to the bleaching agent used) into four subgroups 10 teeth each; as following : control (un bleached) group, hydrogen peroxide group (hp) 35%, carbamide peroxide group (cp) 37% group and sodium perborate (sp) group . the bleaching process was applied three times (4 days intervals) sequentially and the bleached teeth were stored in artificial saliva four weeks before bonding. orthodontic brackets were bonded with a light cure composite resin and cured with led light. after passing 24 hours of bonding procedure, the brackets were debonded by a tinius-olsen universal testing machine, to measure the shear bond strength. after debonding, each bracket base and the corresponding tooth surface were examined using a stereomicroscope and their adhesive remnant index (ari) was recorded. results: the anova test showed that the sbs of stainless brackets was significantly reduced by intracorornal bleaching agents. furthermore, lsd showed no significant difference in sbs between the three types of bleaching agents used in stainless steel group. whilst for sapphire group, the results the anova test showed no significant difference in sbs between the bleached groups and the control group. chi-square comparison no significant difference in failure site between bleached and control groups in both brackets types used. conclusion: the effect of intracoronal bleaching on sbs was reduced sbs of stainless steel and not for sapphire. however, the intracoronal bleaching had no effect on the failure site of orthodontic brackets used. (j bagh coll dentistry 2014; 26(3):149-155). introduction radiant smile is the most beautiful ornament of facial esthetics. the most common reason for seeking the services of the “smile specialist -the orthodontist” is to improve the appearance of the teeth and face. thus, esthetics has emerged as one of the prime goals of orthodontics and dentofacial orthopaedic (1). discoloration of teeth is one of the biggest esthetic concerns of dental patients. tooth discoloration may be classified as intrinsic, extrinsic, or a combination of both. scaling and polishing of the teeth remove many extrinsic stains. (2) harder/deeper extrinsic discoloration and intrinsic staining require various bleaching techniques (3). bleaching defined as the treatment, usually involving an oxidative chemical that alters the light absorbing and/or light reflecting nature of the material /structure thereby increasing its value (whiteness) (4).with increasing demand for adult orthodontics, orthodontists often encounter patients who are unsatisfied not only with the (1)master student, department of orthodontics, college of dentistry, university of baghdad. (2)prof., department of orthodontics, college of dentistry, university of baghdad alignment but also with the colour of their teeth and looking for comprehensive esthetic treatment. vital and non vital bleaching with various whitening agents has now gained worldwide acceptance among clinicians and patients for lightening teeth. (5). bleaching techniques have improved dramatically in an increasing range of products for both vital and non vital bleaching. progress has been made also in orthodontic brackets with the development of attractive materials and functional design. nonvital esthetic treatments such as crowning or the placement of veneers on discoloured teeth (6). walking” bleach technique, is very efficient method to get desired results quickly, easily and economically acceptable (7). today, the most commonly used tooth-bleaching agents contain hydrogen peroxide as the active ingredient. hydrogen peroxide may be applied directly or produced by a chemical reaction from sodium perborate or carbamide peroxide (5). hydrogen peroxide acts as a strong oxidizing agent through the formation of reactive oxygen molecules; these reactive molecules attack longchained, dark coloured chromophore molecules and split them into smaller, less coloured, and more diffusible molecules (6). j bagh college dentistry vol. 26(3), september 2014 effect of three orthodontics, pedodontics and preventive dentistry 150 however, the changes in enamel structure and composition induced by these bleaching agents may decrease the shear bond strength (sbs) of orthodontic brackets (8). bond strength can be defined as force per unite area required to break a bonded assembly with failure occurring in or near the adhesive/adherened interface, it is commonly reported in units of megapascals (mpa) (9, 10). almost all bond strength tests are categorized as tensile or shear bond strength. (11) this study aimed to investigate the effects of three intracoronal bleching agent (hydrogen peroxide 35%, carbamide peroxide 37% and sodium perborate) on bond strength of two type of orthodontic brackets stainless: steel and ceramic (sapphire) brackets, and to determine the predominant site of bond failure shear bond strength test was chosen in this study because it is the common procedure used for the evaluation the bonding efficacy of dental materials (12). material and method 120 freshly extracted human maxillary first premolars were collected which has been extracted from 18-25 years old iraqi patients seeking orthodontic treatment examining the teeth with 10x magnifying lens), and transilluminating light (13), 80 teeth were selected according to the following criteria 1. no cracks or gross irregularities of the enamel structure from the extraction forceps 2. intact buccal enamel surface 3. not treated with a chemical agent such as alcohol, formalin, or hydrogen peroxide or any other form of bleaching (by giving instruction how to collect the teeth and asking the patients if they had teeth bleaching or not) (14-16). preparation of the sample after extraction, the teeth were washed in tap water to remove any traces of blood (17) .then each tooth was thoroughly rinsed to remove any soft tissue remnants and debris (13,17). the collected teeth were stored in a solution of 0.9 % nacl (normal saline) containing thymol crystals 0.1% (wt/vol), and the solution has been renewed systematically each week to prevent bacterial growth and dehydration till required (18-20). endodontic treatment of the teeth standard endodontic treatment for each tooth was done. after that 2 mm of gutta-percha were removed determined by a periodontal probe and removed by gates drill / pesso reamers dental rotary instruments then a layer of resin modified glass ionomer cement (gic) (glass liner/ germany) of 2mm thickness was applied .the sealing material should reach the level of the epithelial attachment or the cej, respectively, to avoid leakage of bleaching agents cervically (21) mounting the teeth each tooth was fixed on a metal slide in a vertical position using soft sticky wax at the root apex so that the middle third of the buccal surface was oriented to be parallel to the analyzing rod of the surveyor (22, 23). this kept the buccal surface of tooth parallel to the applied force during the shear test (24, 20, 25, 26). another two teeth were fixed on the metal slide about 2 cm away from the first tooth and oriented in the same manner in order to have three premolar teeth fixed on the glass slide 2 cm apart the occlusal surface of each tooth oriented to same height by using a stone disc bur (27) (fig 1). after fixing of the teeth, two l-shaped metal plates, were painted with a thin layer of separating medium (vaseline) and placed opposite to each other in such way to form a box around the vertically positioned teeth with the crowns protruding .after setting of the self cured acrylic resin, the two l-shaped metal plates were removed, the sticky wax used for fixation of teeth in the proper orientation removed too and the resulting holes were filled with self cure acrylic. after mounting, the specimens were marked and stored in a saline solution of 0.1% (weight/volume) thymol to prevent dehydration (28, 29,30). a b c figure 1: mounting of teeth, a: fixation of the teeth n the metal plate using sticky wax, b: buccal parallelism of the teeth with the vertical rod of the surveyor, c: occlusal parallelism of the teeth using a stone disc bur j bagh college dentistry vol. 26(3), september 2014 effect of three orthodontics, pedodontics and preventive dentistry 151 bleaching procedure in this experimental study, hydrogen peroxide (35%) intracoronal bleaching (opalacence endo, ultradent products inc, south jordan, utah), carbamide peroxide (37%) intracoronl bleaching (whiteness super endo, dentscare) and sodium perborate (tetrahydrate) intracoronal bleaching (sultan healthcare, englewood, nj 07631). after endodontic treatmet, the teeth randomly divided equally (according to the type of the brackets used) into two main groups (n = 40 per group). each main group then subdivided (according to the bleaching agent used) into four subgroups 10 teeth each; as following : control (un bleached) group, hydrogen peroxide group (hp) 35%, carbamide peroxide group (cp) 37% group and sodium perborate (sp) group . for the control groups, the access cavity was rinsed with distilled water and dried, and the final composite restorations were applied. the bleaching procedure of each sub group was done similarly according to the manufacturer instructions. for the first group, intracoronal bleaching was performed with walking technique using 35% hydrogen peroxide as following (fig 2.a): 1. the restorative temporary filling material were removed by round bur using a slow speed hand piece, to allow bleaching agent to contact the internal tooth structure 2. rinsing the access cavity opening of the teeth was done with distill water and dried by dental air triple syringe. 3. then the bleaching gel was applied by the delivery tip into the pulp champer of each tooth 4. tiny cotton pellet was placed into gel, leaving 1.0 to 1.5mm of space to accommodate the provisional restoration. for the second group, the same steps of walking bleaching technique used in group one were used but by using carabamide peroxide 37% instead of hydrogen peroxide 35% (fig 2.b). for the third group, the same steps of walking bleaching technique used in group one were used but by using sodium perboroate bleaching agent which prepared by the mixing of sodium perborate (tetrahydrate) and water in a 2:1 ratio (g/ml) giving the alkaline ph, then the bleaching agent was applied with an amalgam carrier into the pulp chamber (31) (fig 2, c). this procedure was repeated a further two times (once every four days). after 12 days, the temporary filling material was removed, the access cavity was rinsed with distilled water, and the final composite restoration was applied. the teeth were immersed in daily replaced artificial saliva and allowed to stand for 4 weeks before bracket bonding a b c figure 2: bleaching application, a: hydrogen peroxide, b: sodium perborate, c: carbamide peroxide bonding of the brackets the buccal surface of each tooth was polished using non-fluoridated pumice/water slurry in a rubber cup (for standardization one rubber cup used for each subgroup) attached to a low speed hand piece for 10 seconds (13, 25, 32), then each tooth was washed with water spray for 10 seconds, and dried with oil-free air for 10 seconds (32, 33, 34). the etching agent (37% phosphoric acid gel) then applied to the buccal surface of each tooth for 30 seconds (according to the manufacturer instructions), and then washed with air water spray for 20 seconds, then dried with oil-free air for 20 seconds, the buccal surface of the etched tooth appeared chalky white in colour (35, 21). the bonding was done by applying a very thin coat of sealant/bond enhancer (ortho solo™/ ormco/italy) on the etched enamel surface using a disposable brush in gingivo-occlusal direction and equal amount of the adhesive paste (enlight lv/ormco/italy): was applied on the bracket base according to the manufacturer instructions. two types of roth orthodontic brackets were used in this study; stainless steel brackets, discovery®,(dentaurum company/germany with 8.71 mm² surface area and (sapphire) brackets, perfect clear, (hubit co., ltd / south korea) with 12.2 mm² surface area .each bracket is positioned on the proper site on the middle third of the buccal surface of each tooth parallel to the j bagh college dentistry vol. 26(3), september 2014 effect of three orthodontics, pedodontics and preventive dentistry 152 long axis of the tooth by using a clamping tweezers , then, constant load of 300 gm was placed on the bracket for 10 seconds (36) applied by the vertical arm of the surveyor (which weigh 300 gm) after measuring it by a hand scale by fixing a hard rubber polishing bur in the lower part of the vertical arm of the surveyor and put it in contact with the bonded bracket, to ensure that each bracket was seated under an equal force and to ensure a uniform thickness of the adhesive and prevent air entrapment which may affect bond strength (37). any excess adhesive material was gently removed from around the bracket base with a sharp probe without disturbing the seated bracket (38). for both sapphire and stainless steel brackets the light guide of the curing unit ‘led’ was placed approximately 1 mm away from the bracket (23). the light shined through the brackets for 40 second (10 seconds on each side: mesial, distal, occlusal and gingival) (39). the intensity of the curing light was measured and fixed at 1000mw/c㎡ before each curing cycle (for standardization) by using a curing light meter (40). after completion of the bonding procedure the specimens were immersed in artificial saliva in a glass containers and stored in the incubator at 37º c for 24 hours prior to brackets debonding (41, 42, 38) shear bond strength test each specimen was loaded into a universal testing machine (tinius-olsen universal testing machine) with a 5 kn load cell and a crosshead speed of 0.5 mm/minute and a custom made chisel rod (43, 5). the test was carried out in laboratory of the ministry of science and technology of iraq, with the long axis of the specimen kept perpendicular to the direction of the applied force. the standard knife edge was positioned in the occlusogingival direction and in contact with the bonded specimen.. the values of failure loads (n) were recorded and converted into megapascals (mpa) by dividing the failure load (n) by the surface area of the bracket base. estimation of adhesive remnant index (ari) once the brackets had been debonded, the enamel surface of each tooth was examined under 20x magnification with the stereomicroscope to determine the amount of residual adhesive remaining on each tooth (42). the ari scale used to determine the bond failure sites has a score range between i and iv as described below according to wang et al (44): • score i: between the bracket base and the adhesive. • score ii: cohesive failure within the adhesive itself, with some of the adhesive remained on the tooth surface and some remained on the bracket base. •score iii: between the adhesive and the enamel. • score iv: enamel detachment. statistical analysis data were collected and analyzed using spss (statistical package of social science) software version 15 for windows xp chicago, usa. in this study the following statistics were used: a. descriptive statistics: including means, standard deviations, minimum, maximum, and percentages. b. inferential statistics: including: 1. one way analysis of variance (anova) to test any statistically significant difference among the shear bond strength of three different types of intracoronal bleaching materials. 2. least significant difference (lsd) this is used to test any statistically significant differences between each two sub groups when the anova a statistical difference within the same group or type of bracket. 3. chi-square to test any statistically significant differences between the groups for the failure site examination results. p (probability value) level of more than 0.05 was regarded as statistically non-significant. while a p-level of 0.05 or less was accepted as significant as follows: 0.05≥ p > 0.01 * significant. 0.01≥ p > 0.001**highly significant. results descriptive statistics for the sbs (mpa) of stainless and sapphire groups are showed in tables(1) and (2) respectively..for stainless steel group anova indicated a significant difference between sub groups (p<0.001).lsd showed s a highly significant difference in shear bond strength between each variable compared with the control group(p<0.001).while for sapphire group anova indicated n o significant difference between sub groups (p>0.05). the frequency distribution of the ari scores for the two groups presented in tables (3) and (4). chi-square comparison revealed no significant difference between in the site of bond failure between the control group and the three variables (hp, cp and sp) in both stainless steel and sapphire groups. j bagh college dentistry vol. 26(3), september 2014 effect of three orthodontics, pedodontics and preventive dentistry 153 table 1: descriptive data for shear bond strength test (mpa) of stainless steel group groups mean sd min. max. control 67.474 13.835 48.97 86.91 hp 41.424 14.843 10.33 66.02 cp 45.241 17.560 19.52 72.9 sp 42.838 20.737 11.31 69.12 table 2: descriptive data for the shear bond strength test (mpa) of sapphire group groups mean sd min. max. control 31.031 7.548 16.80 41.15 hp 28.654 7.580 13.48 40.02 cp 29.356 8.694 17.70 45.66 sp 31.703 8.882 25.70 55.49 table 3: distribution and percentage of adhesive remnant index (stainless steel group) table 4: distribution and percentage of adhesive remnant index (sapphire group) discussion orthodontists may encounter patients who are unsatisfied not only with the alignment but also with the colour of their teeth, therefore; it is important when orthodontist faces patient who needs intracoronal bleaching with orthodontic treatment to know is there any undesirable effects of intraconal bleaching on shear bond strength(sbs) of orthodontic brackets. it clearly obvious from the results of this study (table 1), that the teeth bonded with stainless steel brackets after intracoronal bleaching with all types of bleaching agents used showed lower mean value of shear bond strength than that of control group. effects of bleaching on shear bond strength of stainless steel brackets the significant reduction in sbs could be due to changes in enamel and dentine structure that produced because of the low molecular weight of hydrogen peroxide (the active ingredient in all bleaching agents used in this study) that enable it to move through the tooth structure and so denature proteins; this increases tissue permeability and allows ions to move through the tooth (45). the increased time of bleaching application increase porosity or reduce the micro hardness of dentin and enamel by the loss of calcium. these results fully agree with those of most previous studies (46, 47, 38). the decreased adhesive potential of the resinous material to the bleached teeth, and the reduced average values for shear bond strength may be related to free oxygen radicals that released from peroxide based bleaching agents, which are known to have the potential to cause cellular change (48).in addition, sealing the pulp chamber and access cavities where the bleaching was applied before immersion in artificial saliva might retard the elimination the residuals of oxygen from the tooth structure (47), and these residual products suggested to interfere with resin infiltration into the bleached teeth or inhibits resin polymerization and thus reducing the bond strength (49, 50). consistent with these suggested explanations, sbs values were significantly lower in all of the bleached groups than in the control group. on the other hand, these results were disagreed with two previous studies that suggested that bleaching with 10% carbamide peroxide or 35% hydrogen peroxide did not adversely affect sbs of brackets (18, 51), these results may be due different bleaching techniques used. effects of bleaching on shear bond strength of sapphire brackets the results of this study showed no significant difference in bond strength values of sapphire brackets bonded to bleached groups with that bonded to control group (p >0.05) . since there is no study evaluating the effects of inracoronal bleaching on sbs of sapphire brackets according to our knowledge we found the following suggested explanations of the results: 1. the presence of zirconia particles coating the bracket base creates millions of undercuts that groups scores i ii iii iv control no. 6 2 2 0 % 60% 20% 20% 0% cp no. 1 5 4 0 % 10% 50% 40% 0% hp no. 2 4 4 0 % 20% 40% 40% 0% sp no. 1 5 4 0 % 10% 50% 40% 0% groups scores i ii iii iv control no. 0 5 4 1 % 0% 50% 40% 10% cp no. 0 4 6 0 % 0% 40% 60% 0% hp no. 0 2 8 0 % 0% 20% 80% 0% sp no. 0 5 5 0 % 0% 50% 50% 0% j bagh college dentistry vol. 26(3), september 2014 effect of three orthodontics, pedodontics and preventive dentistry 154 secure the bracket in place, by micro mechanical retention means. 2. the translucency that sapphire brackets have, gives a better chance for complete polymerization of the adhesive with light curing. 3. sapphire brackets are single-crystalline brackets so they are hard and offer great strength that prevents or reduces the peeling effects that may occur during brackets debonding thus give them high sbs values. failure site the ari score depend on many factors, which included the attachment base design and the adhesive type, and not only the bond strength at the interfaces. (52) ari scores are used to define the site of bond failure between the enamel, adhesive, and the attachment base through the remaining adhesive on the enamel surface (53). in this study, the results of ari score comparisons indicated no significant difference in failure site between bleached and control groups in both brackets types used. these findings was in agreement with that of gungor et al.(38) and it perhaps due to the use of the same bracket type in each group according to al-naqash (54) that make no difference in the failure sites between bleached and non bleached groups. references 1. chandrashekar mh, parekh j, shendre s. effect of office bleaching agents on the shear bond strength of metallic brackets bonded using self-etching primer system at different time intervals –an in-vitro study. int. j clinical dental sci 2011; 2(2): 84-72. 2. hattab fn, qudeimat ma, al-rimawi hs. dental discoloration: an overview. j esthet dent 1999; 11: 291–310. 3. khan t, ahad b, tahir khan a, nasser a. the effect of bleaching on shear bond strength of orthodontic brackets. pakistan oral & dental j 2012; 32(1): 99103. 4. american association of endodontists. glossary of contemporary terminology for endodontists. 6th ed. chicago; 1998. 5. gungor ay, ozcan e, alkis h, turkkahraman h. effects of different intracoronal bleaching methods on shear bond strengths of orthodontic brackets. angle orthod 2012; (5): 942–6. 6. dahl je, pallesen u. tooth bleaching-a critical review of the biological aspects. crit rev oral biol med 2003; 14: 292–304. 7. stanković t, popović m, karadžić b. the efficacy of “walking” bleach technique in endodontically treated teeth – case report. srbije. 2011; 58(3):1637. 8. turkkahraman h, adanir n, gungor ay. bleaching and desensitizer application effects on shear bond strengths of orthodontic brackets. angle orthod 2007; 77(3):489–93. 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20: 37984. 46. uysal t, er o, sagsen b, ustdal a, akdogan g. can intracoronally bleached teeth be bonded safely? am j orthod dentofacial orthop. 2009; 136(5): 689–94. 47. uysal t, ertas h, sagsen b, bulut h. ozgur er and ustdal a. can intra-coronally bleached teeth be bonded safely after antioxidant treatment? dent mater j 2010; 29(1): 47–52. 48. weitzman sa, weitberg ab, stossel tp, schwartz j , shklar g. effects of hydrogen peroxide on oral carcinogenesis in hamsters. j periodontol 1986; 57: 685-8. 49. miles pg, pontier jp, bahiraei d, close j. the effect of carbamide peroxide bleach on the tensile bond strength of ceramic brackets: an in vitro study. am j orthod dentofacial orthop. 1994; 106(4): 371–5. 50. titley kc, torneck cd & ruse nd.the effect of carbamide-peroxide gel on the shear bond strength of a microfil resin to bovine enamel. j dent res 71(1): 20-24, 1992. 51. uysal t, basciftci fa, usumez s, sari z, buyukerkmen a. can previously bleached teeth be bonded safely? am j orthod dentofacial orthop. 2003; 123(6): 628–32. 52. o′brien kd, watts dc, read mjf. residual debris and bond strengthis there a relationship? am j orthod dentofac orthop 1988; 94(3): 22230 53. santos bm, pithon mm, ruellas aco, sant’anna ef. shear bond strength of brackets bonded with hydrophilic and hydrophobic bond system under contamination. angle orthod 2010; 80: 963-7. 54. al-naqash gs. the effect of temperature variation of composite orthodontic adhesive on shear bond strength. a master thesis, college of dentistry, university of baghdad 2011. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p): 1817-1869, issn (e): 2311-5270 17 research article clinicopathological analysis of 80 cases of oral lobular and non lobular capillary hemangioma (pyogenic granuloma): a retrospective study karrar n.shareef(1), bashar h. abdullah(2) 1 ph.d. student, department of oral and maxillofacial pathology, college of dentistry, university of baghdad. 2 professor, department of oral and maxillofacial pathology, college of dentistry, university of baghdad. *correspondence: karrarnajeh33@gmail.com abstract: background: oral pyogenic granuloma (pg) is a clinicopathological entity that could develop due to the reaction to a variety of stimuli, such as low-grade local irritation, traumatic damage, and hormonal stimulation. there are two histopathological types of pyogenic granuloma; lobular type -capillary hemangioma (lch) and non-lobular type; with pg,lch has highly vascular, diffuse capillary growth while nonlobular variant mimicking granulation tissue with heavily inflammated stroma. the study aims were to review the clinical and histopathological spectrum of an oral pyogenic granuloma from different intraoral sites in order to avoid diagnostic pitfalls associated with similar morphological lesions and to determine whether lobular and non-lobular histopathological subtypes being distinct entities. materials and methods: a retrospective review of eighty formalin-fixed paraffin-embedded tissue blocks (40 cases each of males and females) were retrieved from the archives of oral & maxillofacial pathology at the university of baghdad, from 1979 to 2017. according to mills et al., criteria for lobular capillary hemangioma description, the diagnosis of each case was confirmed by the examination of hematoxylin and eosin stained sections by an expert pathologists. results:the present result revealed that patients with oral pyogenic granuloma were with age range from 12 to 59 years, with a mean of 30.57 years. fourty nine cases (61.25%) out of eighty were of lobular pattern and 31 cases (38.7%) of non-lobular pattern type pg. the most common site of lch was in the buccal mucosa, 12 cases (75%), while higher case numbers were observed in the 21-30 year age group. there were non-significant differences between lobular and non-lobular pattern prevalence regarding age groups and between other studied variables. conclusio: it has been proposed that lch and non-lch subtypes reflect distinct phases in the development of a single lesion, which exhibits variable degrees of proliferative, angiogenic, and inflammatory activities. keywords: lobular capillary hemangioma, pyogenic granuloma, oral cavity,histopathological differences. introduction pyogenic granuloma (pg) is a relatively frequent type of vascular growth on the mucosal surface epithelium and skin. for the first time in 1904, hartzell used the word “pyogenic granuloma” which is a misleading phrase since the lesion does not contain pus, as the name suggests (1,2). the oral pyogenic granuloma is a clinicopathological entity that could result from the tissues reaction to a variety of stimuli such as low-grade local irritation, traumatic damage, and sex hormones. it is a painless growth comonly occurs in maxillary gingival area, particularly on the gingiva's labial side as well as; the prefe ence incidence for the pregnant female, tumor that sometimes grows at an accelerating rate. lesions are more prevalent intra-orally in the anterior and younger age groups, are believed to be due to a hormonal impact on the vasculature. however, a few infections, such as bartonella henselae, have been linked to recurring pyogenic granuloma(3). oral pg is described clinically as a solitary soft mass that may be smooth or lobulated, sessile or nodule-like, or it can be a pedunculated growth. the color of the lesion varies from received date: 9-9-2021 accepted date: 10-11-2021 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v34i2.3142 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i2.3142 https://doi.org/10.26477/jbcd.v34i2.3142 j. bagh. coll. dent. vol. 34, no. 2. 2022 shareef and abdullah 18 pink to red that changes according to its vascularity and tumor progression. there may be some blood flowing spontaneously or as a result of a trauma(2,4). two common histopathological variants of pg were reported in previous studies. the first variant consists of lobular architecture including several small-sized capillaries lined by plump endothelial separated by fibrous septa with a paucity of the inflammatory stromal cells called lobular-capillary hemangioma (lch). non-lobular type pg (non-lch) is the second histopathologic type characterized by highly vascular, diffusely arranged capillary proliferation resembling granulation tissue with heavy inflammatory stroma(5,6). numerous studies have previously investigated the clinicopathologic and immunohistochemical characteristics of pg, but distinctions between pg's two histological variants are uncommon. to avoid diagnostic pitfalls associated with similar morphological lesions and to determine whether lobular and non-lobular histopathological subtypes are two distinct entities, the study aims were to review the clinical histopathological spectrum of an oral pyogenic granuloma from different intraoral sites. materials and methods a retrospective review of eighty formalin-fixed, paraffin-embedded tissue blocks reported as pyogenic granuloma of the oral cavity were retrieved from the archives of the department of oral & maxillofacial pathology/college of the dentistry/university of baghdad; from 1979 to 2017. clinical and demographic data, including the patient's age, gender, and intraoral site of occurrence of pg, were obtained from the relevant histopathological reports that were available with the tissue specimens. according to mills, et al., 1980 criteria for lobular capillary hemangioma description, the diagnosis of each case was confirmed by the examination of h & e sections by an expert pathologists. the statistical analysis was performed as follows: spss version 23 was used to perform statistical analysis. a chi-squared test was applied to test statistical differences. differences between studied variables were set as not significant p>0.05,significant p≤0.05, or highly significant (p≤0.01). results a total of eighty cases (40 cases of males and 40 cases of females) of oral pyogenic granuloma were evaluated. the age ranges of patients with oral pg were from 12 to 59 years, with a mean age of 30.57year. there were no significant differences in the mean age of patients with pg between males (29.77 years) and females (31.37); figure (1). regarding the site, in the present study, equal numbers were collected in both males and females (16 cases from each: gingiva, buccal mucosa, tongue, palate, lips). histopathological study of oral pyogenic granuloma cases revealed that 49 cases (61.25%) out of 80 were of lobular pattern, and 31 cases (38.7%) out of the 80 were of non-lobular pattern type pg. the higher number of cases and percentage of lobular pyogenic granuloma cases were detected in females, 25 cases (62.25%), at a young age (less than 15 years old and age (30-40) receptively, 10 cases (83.33%), and the most common cases were in the buccal mucosa12 cases (75%) while the number and of cases percentage of non-lobular pyogenic granuloma cases showed higher case numbers in the 21-30 years of age group, 12 cases (66.67%), and higher cases of non-lch occurred in the palate, 9 cases (56.25%) j. bagh. coll. dent. vol. 34, no. 2. 2022 shareef and abdullah 19 there were non-significant differences between lobular and non-lobular pattern prevalence regarding age groups, gender; table (1). microscopically, both groups had two distinct components: an ulcerated surface and a deep section. in both groups, the ulcerated surface was equivalent, consisting of inflammatory granulation tissue covered by a fibrinopurulent membrane. the deep part of the lch group had lobular zones of tiny capillaries lined by plump endothelial cells separated by fibrous stroma with little or no inflammatory cell infiltration; figures (2,3). the non-lch type pyogenic granuloma in the deep part showed many dilated capillaries with a dispersed pattern comparable to that of the granulation tissue, which was more infiltrated by chronic inflammatory cells than the lch type figures (4, 5). table (1): demographic description of studied cases (lobular and non-lobular pyogenic granulomas)concerining gender,age,and intraoral sites . parameters lobular non-lobular total p-value gender 24(60%) 25(62.5%) 16(40%) 15(37.5%) 40 40 0.818 ns males females age groups ≤15 16-20 21-30 31-40 41-50 >50 10(83.33%) 10(66.67%) 6(33.33%) 10(71.43%) 7(58.33%) 6(66.67%) 2(16.67%) 5(33.33%) 12(66.67%) 4(28.57%) 5(41.67%) 3(33.33) 12 15 18 14 12 9 0.097ns site gingiva palate lip tongue buccal muccosa 9(56.25%) 7(43.75%) 11(68.75%) 10(62.5) 12(75%) 7(43.75%) 9(56.25%) 5(31.25%) 6(37.5%) 4(25%) 16 16 16 16 16 0.477ns total 49(61.25) 31(38.75) 80 χ 2 test, p<0.05 was selected to improve significant differences j. bagh. coll. dent. vol. 34, no. 2. 2022 shareef and abdullah 20 figure (1): mean age of studied patients independent t-test, ns =non-significant figure (3-b): photomicrograph lobular pg 40x b figure (2-a): photomicrograph lobular pg 10x a figure (3-a): photomicrograph lobular pg 40x figure (2-b): photomicrograph lobular pg 10x b a j. bagh. coll. dent. vol. 34, no. 2. 2022 shareef and abdullah 21 discussion because the oral mucosa is continuously being influenced by external and internal factors, which could be lead to developmental disorders, irritants, inflammatory responses, as well as benign and\or malignancies. these lesions mimic benign and /or malignant clinically. early identification and treatment of such lesions by clinicians may minimize dentoalveolar consequences. this better understanding could help practitioners improve diagnoses and provide appropriate management (7). pyogenic granuloma is a vascular growth that occurs quite often on the mucosal surface epithelium and subcutaneous tissue. the term granuloma pyogenicum (pyogenic granuloma) was coined by hartzell in 1904; while in 1980, the name "lobular capillary hemangioma" (lch) was published as the synonym for pyogenic granuloma according to histological characteristics (5,8). the prevalence of oral pg varied across investigations, ranging from 1.85 percent to 37 percent of reported oral lesions in previous research (9). the clinicopathological findings of the present study revealed that the mean age for the occurrence of pyogenic granuloma was 30.57 years, and a higher number of cases and percentage of lobular pyogenic granuloma cases were detected in females, 25 cases (62.25%). these findings concur with previous studies (10,11). this may reflect a hormonal impact on mucosal lesions (10,12,13). the gingiva was found to be the most often seen intraoral site of pg incidence. following common sites intraorally were the lips, tongue, buccal mucosa, and palate (13). a figure (4-a): photomicrograph non-lobular pg 10x figure (5-a): photomicrograph non-lobular pg 40x a b figure (4-b): photomicrograph non-lobular pg 10x b figure (5-b): photomicrograph non-lobular pg 40x j. bagh. coll. dent. vol. 34, no. 2. 2022 shareef and abdullah 22 although our study involved 16 cases from the gingiva, buccal mucosa, lips, tongue, and palate equally. as well as for both genders. the most striking histopathological feature was detected in all examined oral pg cases was the presence of significant capillary development inside the hyperplastic granulation tissue, indicating the presence of robust angiogenic activity in both histological subtypes (lobular and non-lobular). the histological types of pg have been studied in many prior clinicopathological investigations, some of which included both lch and non-lch histopathological subtypes. some of these studies have shown clinical, histological, and immunohistochemical distinctions between lch and non-lch pg. (2,6); which agrees partially with our study findings that showed statistically clinicopathological differences between lobular and non-lobular subtypes. however, this study did not include immunohistochemical (ihc) makers to support our results. even though immunohistochemistry may help exclude some alternative diagnoses and identify growth features, no immunohistochemical marker was specific for lch, and diagnosis is often made using morphologic criteria. (14). in addition, it is still not obvious how the many etiological factors contribute to the various histological types of pg. accordingly, the oral pg may appear differently, creating a diagnostic challenge for the treating surgeon. as a consequence of an overactive tissue repair reaction, it's a begin vascular tumor. the diagnosis is confirmed by a histopathological assessment, which also excludes out other soft tissue lesions that seem similar. the most significant differential diagnoses are as follows: hemangioma, peripheral giant cell granuloma, peripheral ossifying fibroma, hodgkin’s lymphoma, and conventional granulation as well as, for capillary-type vascular tumors. the presence of giant cells or scattered ossifications inside the tumor stroma assists in ruling out peripheral giant cell granuloma, peripheral ossifying fibroma, or both to rule out are kaposi sarcoma and low-grade angiosarcoma. lobular capillary hemangioma endothelial cells may be somewhat spindled. however, in kaposi sarcoma, the spindle cells are elongated and organized in a slit-like pattern, forming pseudo-vascular blood-filled areas. unlike capillary hemangioma and its variations, kaposi sarcoma lacks conspicuous endothelial cells. human herpesvirus type 8 (hhv8) has been detected in kaposi sarcoma and, if present, may help confirm the diagnosis, additionally, nuclear atypia and pleomorphism are required for the diagnosis of angiosarcoma. while mitotic figures may be observed throughout the proliferative phase of lobular-capillary hemangioma in children and adults, the mitotic index is much increased in angiosarcoma, and the mitoses often take on unusual configurations. neither angiosarcoma nor kaposi sarcoma has an overall lobular architecture; rather, they develop infiltrating. the preferred method of cure is surgical excision. after surgical excision, recurrence is very uncommon (11,15,16). according to the results, this study proposed that lch and non-lch subtypes reflect distinct phases in the development of a single lesion (pg), which exhibits variable degrees of proliferative, angiogenic, and inflammatory activities. our suggestion is the usage of the descriptive term "lobular capillary hemangioma" as a suitable alternative term (pg) in the oral cavity. further research with larger sample size and molecular methods is suggested to confirm or refute this study assumption. conflict of interest: none. j. bagh. coll. dent. vol. 34, no. 2. 2022 shareef and abdullah 23 references 1. kapadia sb, heffner dk. pitfalls in the histopathologic diagnosis of pyogenic granuloma. eur arch oto-rhino-laryngology. 1992;249(4):195–200. 2. epivatianos a, antoniades d, zaraboukas t, et al. pyogenic granuloma of the oral cavity: comparative study of its clinicopathological and immunohistochemical features. pathol int. 2005;55(7):391–7. 3. krishnapillai r, punnoose k, angadi p v, et al. oral pyogenic granuloma-a review of 215 cases in a south indian teaching hospital, karnataka, 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2020;47(2):149–52. 10. toida m, hasegawa t, watanabe f, et al. lobular capillary hemangioma of the oral mucosa: clinicopathological study of 43 cases with a special reference to the immunohistochemical characterization of the vascular elements. pathol int. 2003;53(1):1–7. 11. al-noaman as. pyogenic granuloma: clinicopathological and treatment scenario. j indian soc periodontol. 2020;24(3):233. 12. harris mn, desai r, chuang ty, et al. lobular capillary hemangiomas: an epidemiologic report, with emphasis on cutaneous lesions. j am acad dermatol. 2000;42(6):1012–6. 13. isaza-guzmán dm, teller-carrero cb, laberry-bermúdez mp,et al. assessment of clinicopathological characteristics and immunoexpression of cox-2 and il-10 in oral pyogenic granuloma. arch oral biol [internet]. 2012 may;57(5):503–12. available from: https://linkinghub.elsevier.com/retrieve/pii/s0003996911003827 14. fortna rr, junkins-hopkins jm. a case of lobular capillary hemangioma (pyogenic granuloma), localized to the subcutaneous tissue, and a review of the literature. am j dermatopathol. 2007;29(4):408–11. 15. stagner am, jakobiec fa. a critical analysis of eleven periocular lobular capillary hemangiomas in adults. am j ophthalmol [internet]. 2016;165:164–73. available from: http://dx.doi.org/10.1016/j.ajo.2016.03.010 16. parajuli r, maharjan s. unusual presentation of oral pyogenic granulomas: a review of two cases. clin case reports. 2018;6(4):690–3. j. bagh. coll. dent. vol. 34, no. 2. 2022 shareef and abdullah 24 لـ المرضي السريري ال 80التحليل الفموية الدموية الشعيرات من الصفصمحالة وغير حبيبي ةصصفمة )ورم وعائي ورم رجعيقيحي(: دراسة بأثر (2) عبدهللا حامد، بشار (1) شريف ناجح كرار المستخلص: حالة من الورم الوعائي الحبيبي الشعري المفصص في الفم )ورم حبيبي قيحي(: دراسة بأثر 80التحليل النسيجي المرضي اإلكلينيكي لـ يتطور بسبب تفاعل األنسجة مع مجموعة متنوعة من المحفزات مثل التهيج ( هو كيان إكلينيكي يمكن أن pgالخلفية: الورم الحبيبي القيحي الفموي ) رجعي الورم الوعائي -النوع الفصيصي -الموضعي منخفض الدرجة والضرر الناتج عن الصدمات وتحفيز الهرمونات. هناك نوعان من الورم الحبيبي القيحي نتشر للغاية بينما يحاكي البديل غير الفصيص األنسجة الحبيبية ذات السدى لديه نمو شعري وعائي م pg.lch( والنوع غير الفصيصي lchالشعري ) حالة لكل من الذكور واإلناث( من 40االلتهابي الثقيل.المواد وطرق العمل : تمت مراجعة ثمانين عينة نسيجية مثبتة بالفورمالين و مضمنة بالبارافين ) . بالنسبة لمعايير ميلز وآخرون لوصف الورم الوعائي الشعري 2017إلى 1979اد. مؤرخة في الفترة من أرشيف أمراض الفم والوجه والفكين في جامعة بغد راض. الفصيصي ، تم تأكيد تشخيص كل حالة من خالل فحص المقاطع المصبوغة بالهيماتوكسيلين واأليوزين من قبل اثنين من المتخصصين في علم األم ٪( من أصل 61.25حالة ) 49سنة. 30.57سنة ، بمتوسط 59إلى 12( تراوحت أعمارهم من p.gورم الحبيبي القيحي )النتائج: المرضى الذين يعانون من ال حالة 12في الغشاء المخاطي الشدق ، lch. كان الموقع األكثر شيوًعا لـ p.g٪( من النمط غير الفصيصي 38.7حالة ) 31كانت من النمط الفصيصي و 80 عاًما. ال توجد فروق ذات داللة إحصائية بين انتشار النمط الفصيصي وغير الفصيصي 30-21رتفاع أعداد الحاالت في الفئة العمرية ٪( ، بينما لوحظ ا75) فيما يتعلق بالفئات العمرية باالضافة الى عدم وجود فروق احصائية المتغيرات المدروسة األخرى. تعكس مراحل متميزة في تطور آفة واحدة ، والتي تظهر درجات متغيرة lchوغير lchألنواع الفرعية االستنتاجات: يستنتج من البحث اعاله هو أن ا من األنشطة التكاثرية ، وتولد األوعية ، وانتشار كثيف للخاليا االلتهابية في الورم. amal.doc j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 14 effect of sodium fluoride on the properties of acrylic resin denture base material subjected to long-term water immersion amal abdul-latif rashid, b.d.s., m.sc. (1) abstract background: fluoridated acrylic resin material can present more stable properties when compared with conventional one.the most widely used fluoride –containing substance added to dental resin materials is sodium fluoride (naf). this study evaluated the effect of naf in different concentration to the acrylic resin denture base material and its effect on tensile strength ,modules of elasticity with long –term water immersion (after 4 months immersion in de-ionized water) materials and methods: eighty specimens from dumbbells shaped metal pattern for tensile strength test were preparedaccording to iso 527: 1993 plastic –determination tensile properties ,in dimensions(60mm, 12mm, 3 ± 0.2mm) length, width and depth respectively were allocated to two groups according to water immersion there were 40 specimens before immersion and 40 specimens after water immersion for 4 months in de-ionized water(the de-ionized water was changed every day),these two groups were sub divided in to four groups according to the concentration of naf,naf powder were added to monomer of acrylic in concentrations of 1%,2%and 5% naf .0% naf(control group) ,then mixing were done with polymer according to manufacture instructions ,the conventional flasking ,packing procedure were used following that (fast cycle). for tensile strength test the measuring was done by instron machine, the values of modulus of elasticity were obtained from tensile test. results: results showed that the addition of sodium fluoride to acrylic resin material werelower the tensile strength and modules of elasticity with highly significant differences p<0.01 when compared to control group regardless the concentration of naf,but after immersion (for 4 month ) the tensile strength and modules of elasticity increased in comparison to groups before immersion (with highly significance differences p <0.01 ), highly significance differences (p <0.0)were found between groups after and before immersion in all concentrations except for tensile strength between 1%naf and 2%naf after immersion there was no significant differences(p>0.05), and for modules of elasticity between control and 1%naf, 1% naf and 2%naf( after immersion ),there was only significant differences between them(p<0.05). conclusions: addition of fluoride to acrylic resin material lower the tensile strength and modules of elasticity when compared to control group regardless the concentration of naf, but after immersion (for 4 months ) the tensile strength and modules of elasticity increased in comparison to groups before immersion (with highly significance differences p <0.01) key words: fluoride, acrylic, properties, water immersion. (j bagh coll dentistry 2014; 26(4):14-21). الخالصة الفلوراید المضافة الى األكثر استخداما على نطاق واسع مواد. لالكریلیكمادة الراتنج االكریلیك المفلوره یمكن أن تقدم خصائص أكثر استقرارا بالمقارنة مع المادة التقلیدیة :المقدمة .اتنجیة ھو فلورید الصودیومالموادالر في الماء االیوني لمدى طویل غمر الالمرونة مع معاملومعرفة تأثیره على قوة الشد ، الراتنج الكریلیكلمختلفة من صودیوم الفلوراید اضافھ تراكیز دراسة تأثیر:الھدف من الدراسة ) يغمر في الماء األیونأشھر 4بعد ( قسمت الى قسمین حسب .عرض طول و عمق) 3 ±60,12,0,2(ألختبار قوة الشد وحسب االبعاد حضرت على نمط معدني شكل عظمة الكلب من ةعین80:ملالمواد وطریقة الع إلى أربعة قسمت ھاتین المجموعتین الى عینة بعد الغمر بلماء االیوني لمدة اربعة اشھر مع تغییر الماء االیوني المغمورة فیھ یومیاو 40عینة قبل الغمر و40,الغمر بلماء االیوني صودیوم عدم احتوائھا على سیطرةمجموعة ال(٪0 ,٪5٪ ، 2٪ ، 1 بنسبة االكریلیك سائلتركیز ماده صودیوم الفلوراید ، أضیفت مسحوق صودیوم الفلوراید لفرعیة وفقا ل مجموعات .نعلتعلیمات الص وفقا)البولیمر(بودر االكریلك ثم خلط مع ,)فلوراید . المرونة تم قیاسھا من نتائج اختبار قوة الشد معاملأما .ألختبار قوة الشد تمت بواسطة جھاز االنسترون ة السیطرة مجموعمقارنة مع ) (p <0.01 عالیة فروق معنویةمع وجود , المرونة معاملتظھر النتائج أن إضافة الفلورید إلى مادة الراتنج االكریلیك قد خفض قوة الشد و : النتائج مع مقارنة مع المجموعة قبل الغمرومعامل المرونة تظھر النتائج بزیادة قوة الشد) لمدة اربعة اشھر(يماء االیونلأما بلنسبة للقیاس بعد الغمر ب, بغض النظر عن تركیز صودیوم فلوراید ٪ صودیوم 2٪ ، 1المجامیع والتراكیز قبل الغمر وبعده ماعدا في قیاس قوة الشد بین تركیز بین جمیع ) (p <0.01 ھناك فروق معنویة عالیة).p <0.01 (وجود فروق معنویة عالیة ) بعد الغمر( ٪صودیوم فلوراید 1و مجموعة السیطرةو,٪ صودیوم فلوراید 2٪ و 1تركیز :بین معامل المرونة وبلنسبة لقیاس(p>0.05)فالیوجد فروق معنویة )بعد الغمر(فلوراید .p<0.05)(ق معنویةتوجد فقط فرو , قوة الشد و معامل المرونةمقارنة مع مجموعة السیطرة بغض النظر عن تركیز صودیوم فلورایدالى مواد االكریلك الراتنج یؤدي الى انخفاض نستنتج بأن اضافة الفلوراید:االستنتاجات )p <0.01 (ونة مقارنة مع المجموعة قبل الغمر مع وجود فروق معنویة عالیةتزداد قوة الشد ومعامل المر) لمدة اربعة اشھر(لكن بعد الغمر بلماء االیوني introduction patients have to wear appliance made by acrylic resin all day (orthodontic retainer or removable appliance), so controlling oral hygiene is very important especially for dental caries which the bacteria is the pathological factor for it (1). acrylic resins have been used for the fabrication of denture bases for over 50 years. (1)lecturer. department of dental technologies, college of health and medical technologies. despite the advantages of acrylic, most notably the ease of fabrication with very simple equipment, some limitations have been documented in previous studies such as, high water sorption and solubility of denture base acrylic resins can alter their mechanical properties (2) such as reducing their flexural strength and fatigue limit (3,4). moreover, discoloration and consequently with the esthetic acceptability of dental prostheses (5) in addition to these limitations, their potential to support and promote microbial adherence (6) j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 15 because conventional denture cleaning methods are unable to completely eliminate microorganisms from dentures. specific materials when used in the manufacture of dentures such as the use of fluoridated acrylic can overcome some of these limitations of conventional denture base resins in addition to their potential resistance to microbial adherence (7). these fluoridated denture base resins have shown more stable properties such as decrease water sorption, good resistance to stain and solubility when compared with conventional one (8).the aim of this study was to investigate the influence of sodium fluoride addition on some properties (tensile strength, modulus of elasticity) of heat acrylic denture base material, and its effect with long term water immersion (after4 months immersion). materials and methods preparation of mould -tensile strength preparation of mould: eighty specimens from dumbbells shaped metal pattern were prepared, specimens from heat acrylicdenture base material (type: clear hotcure acrylic resin. germany) were prepared according to iso 527: 1993 plastic –determination tensile properties (9) as shown in figure (1). the measuring of the tensile strength was done in the university of technology by using instron machine (instron, corporation195 canton, mass-u.s.a). a1: overall length 60±2mm. a2: length of narrow parallel – sided portion 16 ± 1mm. b1: width at end 12 ± 1mm. b2: width of narrow parallel – sided portion 3 ± 0.2mm c: thickness 2 ± 0.2 mm. r: large radius 12 ± 1mm figure 1: dimensions of the specimens of tensile strength test concentration of naf in acrylic samples sodium fluoride powder (bhd chemicals ltd .poole england) was weighed by electronic balance(and. co., japan) and added to the monomer (10) according to the concentration in this study :1%, 2%, 5%, for 1% concentration 1gram of naf powder was dissolved in 100 ml monomer, for 2% concentration 2 gram of naf powder was dissolved in 100 ml monomer and for 5% concentration 5 gram of naf powder was dissolved in 100 ml monomer ,then mixed with monomer ,the mixed was done bystirrer (magnetic stirrer janke and kunkel, germany).the suspension of monomer with naf was immediately mixed with acrylic powder according to manufacture instructions to reduce the possibility of particle aggregation and phase separation. distribution of the sample eighty samples from heat acrylic resin denture base material were prepared for tensile strength testanddivided according to water immersion into two groups: first group; 40 sample (before immersion in deionized water) and second group: 40 sample (after immersion in deionized water for 4 months the deionized water which was changed every day)each groups(before and after immersion)was subdivided into four groups according to naf concentration(10 samples for each concentration) :-1% concentration of naf ,2% concentration of naf , 5% concentration of naf and0% concentration of naf which is control group (with out adding naf) proportioning and mixing of the acrylic resin the proportion for mixing of acrylic resin was (2.5/1 by weight) (p/l). the mixing and manipulation was according to manufacturer's instructions. table (1) shows the percentages and amounts of polymer, monomer, and naf powder used in the study (11), for control group:40ml monomer mixed with 100g powder, for 1%naf: 1gm of naf powder dissolved in 100ml monomer, take 40ml from these 100ml and mixed with 99g polymer, for 2% naf: 2gm of naf powder dissolved in 100ml monomer, take 40ml from these 100ml and mixed with 98g polymer and for 5%naf: 5gm of naf powder dissolved in 100ml monomer, take 40ml from these 100ml and mixed with 95g polymer. j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 16 table 1: mixing ratio of acrylic resin naf percentage amount of naf amount of polymer amount of monomer 0% 0 100g 40ml 1% 1g 99g 40ml 2% 2g 98g 40ml 5% 5g 95g 40ml methods the conventional flasking, packing procedures were followed in the preparation of the specimens (12). polymerization all specimens from heat cured acrylicwere polymerized by water bath (fast procedure), polymerization was carried out in case of water bath by placing the clamped flask in water bath and processed by heating at 74 ˚c for 1, 1/2 an hour and the temperature was then increased to the boiling point for half an hour according to adas, no. 12 (13). after completion and curing the acrylic specimens were removed carefully from the stone mold. all the acrylic resin specimens were finished and polished according to conventional procedure till glossy surface was obtained. the final measurements were obtained using the micrometer and vernier. methods of evaluation -tensile strength the tensile strength was tested using instron testing machine equipped with grips suitable for holding the test specimen. set at across head speed of 0.5mm/min, with a chart speed 20mm/min. the load was measured by a tensile load cell with a maximum capacity (200 kg).the recorded force at failure was measured (kg) which were converted into (n) (14). the values of tensile strength were calculated by the following formula (12): where: t.s. = tensile strength (n/mm). f. = force at failure (n). a = area of cross section at failure (mm). -modulus of elasticity: the values of modulus of elasticity were obtained from a chart get from the tensile testing machine. the resultant graphs of stress versus strain from the tensile strength test were used. therefore, the modulus of elasticitywas calculated from the slope of the tangent drawn to the steepest initialstraight line portion of the stress strain curve. the following equationwas used to measure the modulus of elasticity (15) e. = stress / strain e. = modulus of elasticity (n/mm2). stress= force (n). /cross sectional of specimen (mm). strain=original length (mm)/ change in the length (mm). results table 2 and figure 2 showed the descriptive of groups: mean, sd, se, min., max.values of the tensile strength test of all groups. the mean value of tensile strength test were varied according to the concentration of naf ,the tensile strength decreased when concentration of naf were increased, the maximum mean value of tensile strength test recorded by control group before immersion 53.3mpa,while the minimum mean value of tensile strength test recorded by 5% naf before immersion which was equal to26.22mpa, in all groups the mean value of tensile strength were higher in groups after immersion than groups before immersion except for control the mean value of tensile strength test were higher in groups before immersion in comparison to groups after immersion. table 2 descriptive of tensile strength (mpa) test 5% naf 2% naf 1% naf control after before after before after before after before 41.26 26.22 44.52 33.04 44.92 38.28 51.72 53.3 mean 1.163 4.834 0.418 1.679 0.875 3.025 0.545 1.602 sd 0.368 1.529 0.132 0.531 0.277 0.957 0.172 0.506 se 40.1 18.9 44.1 31.3 43.5 35.5 51.3 51 min 43 32 45 36 46.1 43 52.5 54.5 max a f st .. j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 17 figure 2: the mean value of tensile strength test table 3 showed t-test of tensile strength test between groups (control, 1%naf, 2%naf, 5%naf) before and after immersion, there were highly significant differences of tensile strength test (p<0.01) between naf groups (1%naf, 2%naf, 5%naf) before and after immersion except for control there was only significant differences (p<0.05). table 3: t-test between groups before and after immersion of tensile strength test 5% naf 2% naf 1% naf control p-value t-test p-value t-test p-value t-test p-value t-test hs p<0.01 8.386 hs p<0.01 19.2 hs p<0.01 6.682 s p<0.05 2.327 anova test of tensile strength test among groups before immersion and groups after immersion show in table (4), for both groups there highly significant differences (p<0.01). table 4: anova of tensile strength test sig p-value f-test hs p<0.01 139.681 before hs p<0.01 297.885 after table 5 showed the lsd of of tensile strength test between groups ,there were highly significant differences (p<0.01) between all groups (control, 1%naf, 2%naf, 5%naf) after immersion and before immersion except between 1% naf and 2%naf after immersion there was no significant differences (p>0.05). table 5: lsd of tensile strength test sig p-value mean difference groups hs p<0.01 15.020 control&1%naf before hs p<0.01 20.260 control&2%naf hs p<0.01 27.080 control&5%naf hs p<0.01 5.2400 1%naf&2%naf hs p<0.01 12.060 1%naf&5%naf hs p<0.01 6.8200 2%naf&5%naf hs p<0.01 6.8000 control&1%naf after hs p<0.01 7.2000 control&2%naf hs p<0.01 10.460 control&5%naf ns 0.274 0.4000 1%naf&2%naf hs p<0.01 3.6600 1%naf&5%naf hs p<0.01 3.2600 2%naf&5%naf pearson's correlation of tensile strength test show in table (6) there were positive relation between all groups(control, 1%naf, 2%naf, 5%naf), but after immersion there were negative relation between all groups except between (1% naf and 5%naf), (control and 5%naf). j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 18 table 6:pearson's correlation of tensile strength test 5%naf 2%naf 1%naf control groups 0.102 0.348 0.477 control before 0.377 0.390 0.477 1%naf 0.034 0.390 0.348 2%naf 0.034 0.377 0.102 5%naf -0.128 0.310 -0.103 control after 0.154 -0.123 -0.103 1%naf -0.610 -0.123 0.310 2%naf -0.610 0.154 -0.128 5%naf table 7 and figure 3 showed the descriptive of groups: mean, sd, se, min., max. values of modulus of elasticity (n/mm2) test, in all concentration(1%naf, 2%naf, 5%naf), the mean value of modulus of elasticity test were higher in groups after immersion than groups before immersion the mean value of modulus of elasticity test were varied according to the concentration of naf the modulus of elasticitywas decreased when concentrations of naf were increased, also table show the maximum mean value of modulus of elasticity test was recorded by control group before immersion 1.65 n/mm2,while the minimum mean value of modulus of elasticity test was recorded by 5% naf before immersion which was equal to0.7 n/mm2. table 7: descriptive of modulus of elasticity (n/mm2) test 5% naf 2% naf 1% naf control after before after before after before after before 0.98 0.7 1.38 1.16 1.5 1.38 1.62 1.65 mean 0.154 0.094 0.078 0.157 0.066 0.168 0.131 0.135 sd 0.049 0.029 0.024 0.049 0.021 0.053 0.041 0.042 se 0.8 0.6 1.3 0.9 1.4 1.2 1.5 1.5 min 1.2 0.8 1.5 1.3 1.6 1.6 1.8 1.8 max figure 3: the mean value of modulus of elasticity test table 8 showed t-test of modulus of elasticity test between groups (control, 1%naf, 2%naf, 5%naf) before and afterimmersion there were highly significant differences of modulus of elasticitytest (p<0.01) between all groups (1%naf, 2%naf, 5%naf)before and after immersion except for control there was no significant differences (p>0.05). table 8: t-test between groups before and after immersionof modulus of elasticity test 5% naf 2% naf 1% naf control p-value t-test p-value t-test p-value t-test p-value t-test hs p<0.01 4.332 hs p<0.01 4.957 hs p<0.01 3.087 ns p>0.05 0.758 j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 19 anova test of modulus of elasticity test among groups before immersion and groups after immersion is shown in table (9), for both groups there werehighly significant differences (p<0.01). table 9: anova of modulus of elasticity test sig p-value f-test hs p<0.01 80.189 before hs p<0.01 59.359 after table 10 showed the lsd of modulus of elasticity test between groups there were highly significant differences (p<0.01) between all groups (control, 1%naf, 2%naf, 5%naf) after immersion and before immersion, except between control and 1%naf, 1% naf and 2%naf (after immersion), there was only significant differences between them (p>0.05). table 10: lsd of of modulus of elasticity test sig p-value mean difference groups hs p<0.01 0.27000 control&1%naf before hs p<0.01 0.49000 control&2%naf hs p<0.01 0.96000 control&5%naf hs p<0.01 0.22000 1%naf&2%naf hs p<0.01 0.66000 1%naf&5%naf hs p<0.01 0.46000 2%naf&5%naf s p<0.05 0.12000 control&1%naf after hs p<0.01 0.24000 control&2%naf hs p<0.01 0.64000 control&5%naf s p<0.05 0.12000 1%naf&2%naf hs p<0.01 0.52000 1%naf&5%naf hs p<0.01 0.4000 2%naf&5%naf pearson's correlation of modulus of elasticitytest show in table (11) there were positive relation between all groups (control, 1%naf, 2%naf, 5%naf) before immersion except between control and 1%nafthere was negative relation, but after immersion there were negative relation between all groups except between (1%naf and 2%naf), (1%naf and 5%naf) and (2%naf and 5%naf) there were positive relation between them. table 11: pearson's correlation of modulus of elasticity test 5%naf 2%naf 1%naf control groups 0.000 0.208 -0.195 control before 0.699 0.468 -0.195 1%naf 0.747 0.468 0.208 2%naf 0.747 0.699 0.000 5%naf -0.087 -0.171 -0.127 control after 0.430 0.845 -0.127 1%naf 0.509 0.845 -0.171 2%naf 0.509 0.430 -0.087 5%naf discussion specific materials when used in the manufacture of denture care enhance the elimination of micro-organisms to promote oral hygiene (16), fluoride is widely used for caries controland in same way to improve the properties of acrylic resin (9,17). in the present study the tensile strength and modulus of elasticity tests of acrylic denture base material were evaluated after the addition of sodium fluoride with different concentrations which may supposed to improve the properties of acrylic resin, butthe tensile strength and modulus of elasticity of all samples containing fluoride is lower than tensile strength in comparison to the control with highly significant differences (p<0.01) the possible explanation for lower mean tensile strength and modules of elasticity reside in the intermolecular interaction .the presence of fluoride in methacrylat polymers results on j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 20 different intermolecular distances (18), fluoride acrylic usually have lower mechanical strength than conventional materials due to decrease cohesive energy that reduce the effect of polymer chain entanglement (7); however part of this decline can be explain by the dilution of other components of the liquid , such as the cross linking agent (19) there is association between increasing concentrations of cross linking agent and increased tensile strength and modules of elasticity (20), so addition of naf will dilute this component(that responsible for increasing tensile strength) which lead to lowering the tensile strength, this results agreement with others studies (9,17,18). another explanation for decreasing the tensile strength was related to the primary problem with incorporation of inorganic fluoride into dental resins is an inherent incompatibility caused by a large difference in polarity between the ionic fluoride and the low-polarity dental resin, the latter being an organic material. incompatibility usually causes phase separation with the resin, loss of mechanical integrity of the resin and rapid fluoride ion release within the first few hours of use. incorporation of low molecular weight organic fluoride species has a plasticizing effect which leads to similar undesirable results (7) after immersion for four months in de-ionized water the tensile strength and modules of elasticity was increased ,this may be due to release of fluoride and decreased its effect ,in previous studies (9,21) show the fluoride release was observed with first 2 day then decrease fluoride level after 2 day and the release of fluoride become in small concentration and it is duration of release depend on the types of fluoride used,example for caf2, fluoride release up to six months ,but for naf the release continue up to four months, so in this study the immersion time was 4 months depend on previous results after fluoride release its effect become negligible ,so the tensile strength and modules of elasticity was increased this result was disagreement with srithongsuk et al. (17) study that show the tensile strength decreased over time during fluoride release. concentrations of fluoride used in this study was 1 %, 2%, 5%, according to previous studies (9,16,20) that study different concentrations of naf fluoride. high concentrations of fluoride were studied (9,17) 10%, 20% but the maximum concentrate for naf was 20% ,because dough stage was not reached for 25% or more. the concentration release in the in vitro experiment may be presumed to occur in vivo at some higher level due to larger size of dental appliances, using naf because it is the most elevated release of fluoride compounds than other types of fluoride following by caf 2then amine fluoride this may be related to the solubility's of the compounds (21). other limitations should be stated, the scarce literature on this subject, since no iraqi study was found describing the incorporation of naf in acrylic resin proprietary materials, with only a small number assessing the use of fluoridated polymers for dental applications. references 1. kidd e. and jouyston – bechal s: essentials of dental caries. the disease and its managements 2ed ed. hong kong: oxford; 2002. p.1-20. 2. braden m. some aspects of the chemistry and physics of dental resins. adv dent res 1988; 2: 93-7. 3. dixon dl, ekstrand kg, breeding lc. the transverse strengths of three denture base resins. j prosthet dent. 1991; 66: 510-3. 4. fujii k. fatigue properties of acrylic denture base resins. dent mater j 1989; 8: 243-59. 5. guler au, yilmaz f, kulunk t, guler e, kurt s. effects of different drinks on stainability of resin composite provisional restorative materials. j prosthet dent 2005; 94:118-24. 6. radford dr, sweet sp, challacombe sj, walter jd. adherence of candida albicans to denture-base materials with different surface finishes. j dent. 1998; 26: 577-83. 7. stansbury jw, antonucci jm. dimethacrylate monomers with varied fluorine contents and distributions. j dent mater 1999; 15: 166-73. 8. hayakawa i, akiba n, keh e, kasuga y. physical properties of a new denture lining material containing a fluoroalkyl methacrylate polymer. j prosthet dent 2006; 96: 53-8. 9. iso 527. international organization for standardization. plastic-determination of tensile properties. 1993 10. cunha tr, regis rr, bonatti mr, de souza rf. influence of incorporation of fluoroalkyl methacrylates on roughness and flexural strength of a denture base acrylic resin. j appl oral sci 2009; 17(2): 103-7. 11. suryanarayana c. non-equilibrium processing of materials. 1st ed. oxford: elsevier science ltd; 1999. p. 307. 12. craig rg, powers jm. restorative dental materials. 11th ed. st. louis: mosby co.; 2002. p. 150-200. 13. ada: american dental associated specification no.12 for denture base polymers. chicago; council on dental materials and devices. 1999. 14. abu-anzeh mi. evaluation of tensile bond strength of toothdenturebase resin as a function of different surface treatments and processing regimes. a master thesis, college of dentistry, university of baghdad, 2003. 15. anusavice kj. phillips science of dental materials. 10th ed. philadelphia: w.b. sanders co.; 1996. pp. 211-35, 237-71. j bagh college dentistry vol. 26(4), december 2014 effect of sodium restorative dentistry 21 16. larsen mj, bruun c. caries chemistry and fluoride mechanisms of action. in textbook of clinical cariology. 2nd ed. copenhagen: munksgaard; 1994. p. 231-57. 17. srithongsuk s, anuwongnikroh n, dechkunakom s,srikhirin t, tua-ngam p. investigation of fluoride release from orthodontic acrylic plate. advanced material res 2012; 37: 681-7. 18. kurata s, yamazaki n. mechanical properties of poly (alkyl alpha-fluoroacrylate) as denture-base materials. j dent res 1989; 68: 481-3. 19. dhir g, berzins dw, dhuru vb, periathamby ar, dentino a. physical properties of denture base resins potentially resistant to candida adhesion. j prosthodont 2007; 16: 465-72. 20. arima t, hamada t, mccabe jf. the effects of crosslinking agents on some properties of hemabased resins. j dent res 1995; 74: 1597-601. 21. zitz a, gedalia i, grajower raddition of fluoride compounds to acrylic resin plates: bending strength and fluoride release.j oral rehabil 1981; 8(1): 37-41. type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 36 research article effect of adding titanium dioxide nanoparticles on antimicrobial activity and surface detail reproduction of dental alginate ranj a. omer 1*, hoshang kh. abdel-rahman 2, mahabad m. saleh 2 , sazgar s.q. al-hawezi 3, fahd s. ikram5 1 gasha technical institute, department of dental technology, iraq. 2 department of prosthodontics, college of dentistry, hawler medical university, iraq. 3 department of conservative dentistry, college of dentistry, hawler medical university, iraq. 4 department of prosthodontics, college of dentistry, hawler medical university, iraq. * correspondence: dentist_46@yahoo.com abstract: most dental works require a diagnostic impression; alginate is contemplated as the most popular material used for this purpose. titanium dioxide nanoparticles show evidence of antimicrobial activity in the recent era, for this purpose, this study aimed to evaluate the effect of adding titanium dioxide nanoparticles on antimicrobial activity and surface detail reproduction of alginate impression material. materials and methods: titanium dioxide nanoparticles (purity = 99%, size= 20nm) was added to alginate at three different concentrations (2%, 3% and 5%). 84 samples were prepared in total. samples were tested for antimicrobial activity using a disc diffusion test, and surface detail reproduction was done using (iso 21563:2021). one-way anova and independent sample t-test were used for data analysis through spss software. results: for the antimicrobial test, inhibition zones for streptococcus mutans and candida albicans showed significant changes concerning the alteration in titanium dioxide nanoparticle concentrations. the inhibition zone significantly increased with an increase in the percentage of titanium dioxide nanoparticles. the mean of the inhibition zone for s. mutans was superior to c. albicans and the difference was statistically significant. regarding surface detail reproduction, the control group, 2% and 3% groups manifested very similar results, only the group to which 5% of titanium dioxide nanoparticles were added showed a decline in detail reproduction when compared to the other three groups. conclusion: within the limitation of this study, we can conclude that the antimicrobial activity against s mutans and c. albicans were significantly increased in modified groups, and this escalation was directly linked to the increase in titanium dioxide nanoparticles concentration. in contrast, the surface detail reproduction was decreased when adding 5% titanium dioxide nanoparticles to alginate. keywords: alginate, surface detail, nanoparticle, candida albicans. introduction dental impression is a negative replication of hard and soft tissues in the mouth from which a positive reproduction (dental cast) can be formed1. alginate is a biomaterial from a family of irreversible hydrocolloid that has served dental practice for almost century2.they were the first elastic impression material to be used in dentistry that provided high detail even under the presence of undercuts3. being economical, easy to manipulate, and better tolerance received date: 09-05-2022 accepted date: 10-06-2022 published date: 15-03-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v35i1.3313 mailto:dentist_46@yahoo.com https://orcid.org/0009-0004-8106-7887 https://orcid.org/0000-0001-9025-3754 https://orcid.org/0000-0002-9913-6084 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3313 https://doi.org/10.26477/jbcd.v35i1.3313 j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 37 by the patient has put alginate in the utmost utilized material in the field of dentistry in contrast to other impression materials such as silicon4. all types of irreversible hydrocolloids have a hydrophilic nature making them susceptible to microbial retention5. it is a well-known fact that the human oral cavity is a favourable host to many microbial agents, during the impression-making procedure the oral cavity fluid could adhere to the impression materials6. therefore, they may increase the susceptibility of cross infection7. to overcome this point, many disinfection methods have been used such as spraying and immersing. unfortunately, both methods are time-consuming and may compromise some of the mechanical properties of the alginate8. during the last decade, the use of nanoparticles has become prevalent in the design and development of many dental materials since they can provide a unique combination of properties9. due to the small size of the nanoparticles, they can provide a high surface area to volume ratio compared to particles of the same material10. this property gives them great attention in the present century as they possess defined mechanical, chemical, and optical properties crafting them into a suitable candidate for various applications11. many studies proved that nanoparticles could control the formation of biofilms as they possess biocidal and anti-adhesive properties. for this purpose, silver, copper, zinc, magnesium, titanium, and their oxides have been used as antimicrobial agents in many dental materials12. it was proven that tio2 nps possess good antibacterial activity against s. mutans13, without deteriorating the mechanical and physical properties13-15. due to their imperfect properties, alginate remains an active material for research. the purpose of this study is therefore to evaluate the antimicrobial property of dental alginate incorporated with tio2nps against s. mutans and c. albicans, in addition to the surface detail reproduction after this modification. materials and methods to confirm the identity of the planned tio2nps for use in this study, x-ray diffraction (xrd) analysis was performed before starting sample preparations. x-ray diffraction is a powerful non-destructive analytical method that is used to determine the structure and composition of unknown nanomaterials16,17. xrd test was performed using panalytical x’pert powder (figure 1.a) with cu-kα x-ray source, a wavelength of =1.54060�̇� was used. the tio2nps were deposited on to the specimen holder (figure 1. b) and packed using a glass slide. the nps inside the sample holder were loaded into the xrd machine and diffraction data was recorded at 2 range from 10 to 79.9950 with step size 0.0100 per 0.5s. low scan speed was elected to provide higher sensitivity for the recognition of impurities18. j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 38 figure 1: a) panalytical x’pert powder b) specimen holder the panalytical software was used to compare x-ray xrd patterns to identify the nps. the result of the analysis identified the sample as tio2 and its diffraction pattern are shown in figure (2): figure 2: xrd pattern for titanium oxide nanoparticles after confirming the identity of the chosen tio2nps, a pilot study was done by ftir analysis to reveal any possible chemical structure changes (alteration of functional groups) after adding (2%, 3% and 5%) of tio2nps to the alginate, control and modified groups were analysed by the ftir spectroscopy (shi j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 39 madzu 8400, japan). the result (figure 3) provided a clear clue that the in cooperation of tio2nps at all concentrations doesn’t induce any significant change in the main functional groups' structure for the (si-o-si group, c-o-c group, o-h group and c-h group) which was present in the unmodified alginate as the stretching and bending of the peaks did not alter after the addition of tio2nps. the only detected change was the increase in the percentage of ir transmittance which was detected only in the 5% tio2nps group, indicating the weakening of the bonds between the alginate molecules. similar to the control group, sharp, strong peaks at 619.21 cm-1, 669.83 cm-1 and 793.54 cm-1 for si-o-si bands, also the peak at 1078.81 cm-1 for c-o-c bands were observed in all modified groups indicating that the added tio2nps does not interact with the available structural bonds in the alginate, this finding agrees with skocaj et al 19 who stated that tio2nps considered as a chemically inert material. the weak sharp bending peak of the o-h group at 1621.88 cm-1 was very similar in control, 2% tio2nps and 3% tio2nps as the ir transmittance located at the same levels, but for the 5% group although the bands located at the same wavelength level but, the ir transmittance increased which is an indication that the higher tio2nps concentration might cause weakening of these bands due to the agglomeration of the tio2nps20. the weak stretch peak of the c-h group at 2924.61 cm-1, also the strong stretch peak of the o-h group at 3421.89 cm-1 and 3527.51 cm-1 for the control, 2% tio2nps and 3% tio2nps groups was almost identical but again there was a difference in the ir transmittance rate in which for the 5% tio2nps group was 80%, while for the former three groups at about 50%, this might be due to formation of small gaps between these molecular groups band which ultimately caused the bonds to become weaker20 thus the ir easily penetrated the samples contained a higher percentage of 5%tio2 nps. figure 3: ftir analysis of alginate (blue =control, pink=2%, green =3%, black= 5%) j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 40 study design and sample preparation in the present study, 84 samples were prepared from alginplus (majoriso 21563. italy) extra high precision alginate impression material. antimicrobial activity against s. mutans (n=28) and c. albicans (n=28) in addition to surface detail reproduction (n=28) were tested. one control group and three modified groups to which (2%, 3% and 5%) spheric shaped tio2nps were added respectively to the alginate have been studied, each group consisting of seven samples. digital electronic balance (ohaus gmbhswitzerland) with precise accuracy of 0.0001 mg was used to weigh the alginate powder and the amount of tio2nps powder. the samples were prepared by mixing the blend of both powders (alginate and tio2nps) with a premeasured volume of distilled water as recommended by the manufacturer by using an automatic alginate mixer (cavexnetherlands) for 10 seconds. antimicrobial test a disc diffusion test was used to investigate the antimicrobial activity released from the tested alginate specimens. for this purpose, two main oral pathogens namely s. mutans atcc 25175 and c. albicans atcc 10231 yeasts were chosen. the s. mutans bacteria were cultivated on blood agar media. the culture media was prepared according to the recommended protocol for s. mutans. seven petri dishes were used, and in each petri dish, four specimens were placed at equal distances from each other, marked with numbers 1, 2, 3 and 4 representing the control, 2%, 3% and 5% groups respectively and incubated aerobically at 37°c for 24 hours. for the c. albicans atcc 10231, sabouraud dextrose agar was used for growing and cultivation21. the protocols from antifungal susceptibility testing of the national committee for clinical laboratory standards (nccls) and manual of antimicrobial susceptibility testing were followed22,23. the seven petri dishes containing samples were incubated for 24 hours. the measurement of inhibition zones for both pathogens was performed using scientific image analysis known as image j software24. after completion of 24 hours incubation, the petri dishes were taken out from the incubator, and images were taken at 90º with a reference of a ruler for calibration of image j software. inhibition zones were measured around the ingots at six different positions. for the entire procedure, the working environment was conditioned under bio air top safe with continuous air ventilation and a bunsen burner that was turned on near the working field to prevent contamination of the testing components by airborne pollutants25.26. surface detail reproduction a stainless-steel die with three scribed parallel lines iso 21563: 202127 is used for surface detail reproduction. the widths of these lines were 20-μm, 50-μm and 75-μm respectively. a stainless-steel ring was j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 41 0.2008 0.1901 1.2207 1.89042.2194 3.11352.7262 4.4552 0 2 4 6 c.albicans s.mutans m e a n i n h i b i t i o n z o n e ( m m ) control 2% 3% 5% placed on top of the steel die; the mixed alginate was poured inside the ring over the testing mould. a glass slab was then placed on top of the ring and a one-kilogram weight was positioned upon the slab for 10 minutes. then, the samples were carefully removed from the mould and immediately examined with a digital microscope um012c (5m 300x with 8 ledschina). prior to the measurement procedure, the microscope eyepieces lens was calibrated for precise measurements of the samples. specimens were reported to either pass (1) or fail (0) the test based on their ability to capture the entire length of the scribed 20-um line over the full length of 25mm distance between the cross line27,28. the surfaces were assessed according to the ranking system established by owen29 which are: score 1: line reproduced clearly and sharply over the entire length between the marks. score 2: line clear over more than 50% of length, or line indistinct over less than 50% of length, the line appears to be reproduced well over the entire length, but not sharply. score 3: line clear over less than 50% of length, line indistinct over more than 50% of length, or line visible over entire length but blemished not sharp. score 4: line is not reproduced over the entire length; rough, blemished, pitted. statistical analysis statistical package for social sciences (spss, version 23.0) and microsoft office excel were used for statistical analysis. descriptive statistics for frequency, mean, and standard deviation. student t-test was used for comparisons between two independent groups, in addition to one-way anova and post hoc test for multiple comparisons. the p<0.05 value was considered statistically significant. results the obtained results from the antimicrobial test showed that the control group exhibited the least antimicrobial activity; furthermore, it was observed that the inhibitory effect against both pathogens was directly linked to the increase in the concentration of tio2nps as shown in figure (4) the inhibitory effect of the modified alginate against s. mutans was more dominant compared to c. albicans which revealed higher resistance to the added tio2nps at the same concentrations. figure 4: mean inhibition zone for s. mutans and c.albicans j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 42 for s. mutans, the results of one-way anova revealed a statistically significant difference (p < 0.05) in the inhibition zone measurements as shown in table (1). table 1: one-way anova test for s.mutans group n mean+sd 95% ci for mean lower band upper band f sig p-value control 7 0.19014 (0.00661) 0.18402 0.19626 534.957 0.000 2%tio2nps 7 1.89043 (0.12906) 1.77106 2.00979 3%tio2nps 7 3.11357 (0.37468) 2.76704 3.46010 5%tio2nps 7 4.45529 (0.12333) 4.34122 4.56935 total 28 2.41236 (1.61205) 1.78727 3.03745 post hoc (lsd) test for multiple comparisons depicted a statistically significantly different between the groups in such a way that the added tio2nps improved the antibacterial activity of the used alginate in all used concentrations as shown in table (2). table 2: post hoc test (lsdmultiple comparisons) for s. mutans group i group j mean difference (i-j) 95% ci for mean lower band upper band sig p-value control 2% tio2nps -1.700286* -1.92925 -1.47132 0.000 3% tio2nps -2.923429* -3.15239 -2.69446 0.000 5% tio2nps -4.265143* -4.49411 -4.03618 0.000 2% tio2nps 3% tio2nps -1.223143* -1.45211 -0.99418 0.000 5% tio2nps -2.564857* -2.79382 -2.33589 0.000 3% tio2nps 5% tio2nps -1.341714* -1.57068 -1.11275 0.000 regarding c. albicans, the obtained results were identical to the results of s. mutans as there was a statistically highly significant increase in the antifungal activity of the alginate in the modified groups. the inhibition zone was more dominant at the highest percentage (5%) of used tio2nps compared to the 2% and 3% groups. the control group possessed a minimum inhibition zone as shown in table (3). table 3: one-way anova test for c. albicans group n mean+sd 95% ci for mean lower band upper band f sig p-value control 7 0.20086 (0.00470) 0.19651 0.20521 926.760 0.000 2% tio2nps 7 1.22071 (0.06380) 1.16170 1.27973 3% tio2nps 7 2.21943(0.14397) 2.08627 2.35258 5% tio2nps 7 2.72629 (0.11391) 2.62093 2.83164 total 28 1.59182 (0.99070) 1.20766 1.97598 j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 43 post hoc test for multiple comparisons between the groups showed the presence of highly significant difference (p < 0.001) between the control group and the other groups as well as between the groups themselves as shown in table (4). table 4: post hoc test (lsdmultiple comparisons) for s.mutans c.albicans group i group j mean difference (i-j) 95% ci for mean lower band upper band sig p-value control 2% tio2nps -1.019857* -1.12710 -0.91261 0.000 3% tio2nps -2.018571* -2.12582 -1.91133 0.000 5% tio2nps -2.525429* -2.63267 -2.41818 0.000 2% tio2nps 3% tio2nps -0.998714* -1.10596 -0.89147 0.000 5% tio2nps -1.505571* -1.61282 -1.39833 0.000 3% tio2nps 5% tio2nps -0.506857* -0.61410 -0.39961 0.000 an independent sample t-test was used to evaluate whether s. mutans and c. albicans differ significantly in their inhibition zone. the result specified that the mean of the inhibition zone for s. mutans and c. albicans was statistically significant as shown in table (5). the means indicated that s. mutans (m = 2.41236, sd = 1.61205) showed significantly more inhibition zone than c. albicans (m=1.5917, sd=0.99070). table 5: independed student t-test for s. mutans and c. albicans. levene's test for equality of variances t-test for equality of means f sig. t df sig.(2 tailed) mean difference std. error difference equal variances assumed. equal variances not assumed 8.204 0.006 2.295 54 0.026 0.820536 0.357582 2.295 44.849 0.026 0.820536 0.357582 surface detail reproduction the alginate used in this study is branded as an irreversible hydrocolloid material that satisfies iso 21563. all the tested groups efficiently and sharply recorded the 75-µm line in the entire length thus satisfying owen’s score 1. regarding 50-µm line, the control group, 2% and 3% groups reproduced that line on the alginate samples surface with owens score 2 except for 5% tio2nps group that fall into owens score 3. as mentioned previously, due to extra high quality of the used alginate in this study, the reproduction of the 20-um line was selected and considered as the base line for comparison between the groups. the group that was altered by addition of 5% of tio2nps failed to record the 20-µm line (figure 5), while the remaining three groups reproduced 20-µm line and this ability is considered as an equivalent to the detail reproduction of the addition silicones according to iso specifications 482330. j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 44 figure 5: surface detail reproduction discussion infection control is a fundamental procedure in dental practice. it is documented that there are about 750 million microorganisms in only 1 ml of the saliva of a healthy person31. according to many researchers, spherical-shaped nanoparticles with sizes 15-50nm exhibit maximum antimicrobial properties32. due to this, spheric-shaped 20 nm tio2nps were chosen for this study. the result of the inhibition zone for s. mutans showed a significant increase when the percentage of tio2nps increased, a similar finding was obtained in a study by al-hawezi13 when tio2nps were in cooperated into a flowable dental composite resin and agreed with the result obtained in studies done for testing the effect of silver nanoparticles on s. mutans33,34. the antibacterial activity of tio2nps is practically due to a reaction of the high surface energy tio2nps with water. tio2nps release free radicals which are considered a potent oxidizing agent (reactive oxygen species) that ultimately destroy the cell membrane35 or alternatively, in the absence of light, direct contact and adsorption of cells onto tio2nps may cause a loss of bacterial cell membrane36. additionally, reports in the literature have shown that electrostatic attraction plays a great role in the bactericidal effect of the material37. this attraction probably overcomes other factors, such as the size and shape of nps which can influence bacterial cell death38. the antifungal effect of tio2nps against c. albicnas was obvious in the modified groups when compared to control group, this finding agrees with results of a study39 who found that up to 65% of the c. albicans were killed after exposure to 100 μg/ml of tio2nps. a similar results was concluded with of kermani et al40 who found that higher percentage of the titanium and zinc oxide nanoparticles increased their toxicity. control 2 tio2nps 3% tio2nps 5% tio2nps owens 1 1 0 0 0 owens 2 1 3 2 0 owens 3 5 4 5 0 owens 4 0 0 0 0 1 0 0 0 1 3 2 0 5 4 5 00 0 0 0 0 1 2 3 4 5 6 sa m p le n u m b e rs surface detail reproduction 20-um owens 1 owens 2 owens 3 owens 4 j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 45 it was documented that tio2nps cause c. albicans yeast cell death by producing intracellular reactive oxygen species (ros), this in turn causes oxidation of the coenzyme-a and peroxidation of lipids which subsequently decreases respiratory activity and ultimately causes cell death41. another explanation for the antifungal activity of tio2nps, is the tear of the fungi cell membrane that disturb its integrity, causing loss of intracellular substances 42. impression-making is a routine in the dental practice, for this purpose, a variety of impression materials are available to capture oral cavity structures, the final decision for the selection of these products is usually based on the required type of dental treatment and clinician’s preference43. surface detail reproduction is considered fundamental criteria for any irreversible hydrocolloid material, the latest iso 21563 and ada specification 18 is used as a standard protocol for measuring this property. the results of the present study were similar to another study 44 when they found no adverse effect of incorporating up to 1000 ppm of silver nanoparticle on the surface detail reproduction of alginate. this could be the result that the tio2nps were small (20nm) thus the particles were evenly distributed within the alginate matrix and did not influence the intermolecular bond. in addition, these nanoparticles are considered an inert material and do not induce any chemical structure alteration, this fact was supported by the ftir analysis results. at 5% tio2nps, caused deterioration of the surface detail reproduction and it was impossible to record the 20-m line, this may be due to agglomeration of the used tio2nps inside the alginate matrix because of their high surface energy 45, this in turn triggered a poor intermolecular bond. according to obtained data, the requirements were met for irreversible hydrocolloid material as the tested groups reproduced the 75-µm and 50-µm groove which is considered satisfactory for alginate impression materials,46. conclusion within the limitation of this study, we can conclude that the addition of tio2nps to alginate improved the antimicrobial activity significantly. tio2nps are more powerful against s. mutans at the same used concentration. the addition of tio2nps doesn’t compromise the iso 21563 requirement for surface detail reproduction. conflict of interest: none. references 1. hamalian, t. a., nasr, e., chidiac, j.j. impression materials in fixed prosthodontics: influence of choice on clinical procedure. j prosthodont. 2011; 20(2):153-60. 2. hansson, o., eklund, j. a historical review of hydrocolloids and an investigation of the dimensional accuracy of the new alginates for crown and bridge impressions when using stock trays. swed dent j. 1984; 8(2): 81-95. 3. cervino, g., fiorillo, l., herford, a., et al. alginate materials and dental impression technique: a current state of the art and application to dental practice. mar drugs. 2018; 17(1): 18. j. bagh. coll. dent. vol. 35, 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antifungal activity against oral candida species using a denture base coated with silver nanoparticles. j nanomater. 2014; 2014: 48. 43. manar, j. alginate as impression material. j appl oral sci. 2018; 4(3): 300-3. 44. omidkhoda, m., hasanzadeh, n., soleimani, f. antimicrobial and physical properties of alginate impression material incorporated with silver nanoparticles. dent res j. 2019; 16(6): 372-376. 45. watson s, beydoun d, scott j, et al. preparation of nanosized crystalline tio 2 particles at low temperature for photocatalysis. j. nanopart res. 2004 jun;6:193-207. 46. american dental association specification no. 18. dental alginate impression materials. 1992. األلجينات السنية لمادة تفاصيل السطح لتيتانيوم النانوية على نشاط مضادات الميكروبات ونسختأثير إضافة جزيئات ثاني أكسيدا https://onlinelibrary.wiley.com/action/dosearch?contribauthorraw=hu%2c+hailong https://onlinelibrary.wiley.com/action/dosearch?contribauthorraw=fan%2c+xingpei https://onlinelibrary.wiley.com/action/dosearch?contribauthorraw=yin%2c+yao j. bagh. coll. dent. vol. 35, no. 1. 2023 omer et al 48 اكرام سداد فهد, صالح محمود مهاباد , الحويزي قاسم سربست سازكار ,عبدالرحمن خالد هوشنك ,عمر ازاد رنج :الباحثون المستخلص: األكثر شيوعًا لهذا الغرض. تظهر الجسيمات النانوية لثاني أكسيد التيتانيوم دليالً على أعمال طب األسنان تتطلب انطباعًا تشخيصيًا ،الجينات هي المادة المستخدمة معظم: الخلفية ى النشاط المضاد للميكروبات ونسخ تفاصيل السطح عل tio2npsنشاط مضادات الميكروبات في العصر الحديث ، ولهذا الغرض تهدف هذه الدراسة إلى تقييم تأثير إضافة الجينات. لمادة االنطباع عينة في المجموع. تم اختبار عينات 84٪(. تم تحضير 5٪ و 3٪ ، 2نانومتر( إلى الجينات بثالث تركيزات مختلفة ) 20٪ ، الحجم = 99)نقاء = tio2npsتمت إضافة . iso 21563: 2021انتشار القرص ، وتم اختباراستنساخ تفاصيل السطح باستخدامالنشاط المضاد للميكروبات باستخدام اختبار .spssالمستقل من خالل برنامج tأحادي االتجاه واختبار anovaلتحليل البيانات تم استخدام ،وزادت منطقة tio2npsالميكروبات ،أظهرت مناطق التثبيط للمكورات العقدية الطافرة والمبيضات تغيرات معنوية ذا عالقة بالتغير في تركيزات بالنسبة الختبار مضادات ة. فيما يتعلق باستنساخ وكان االختالف ذا داللة إحصائي c. albicansأعلى من s. mutansمنطقة التثبيط لـ . كان متوسط tio2npsالتثبيط معنويا مع زيادة نسبة إضافة 3٪ و 2تفاصيل السطح ، أظهرت المجموعة الضابطة، إليها أظهرت انخفاًضا في استنساخ tio2nps٪ من 5٪ نتائج متشابهة جدًا ، فقط المجموعة التي تمت التفاصيل عند مقارنتها بالمجموعات الثالث األخرى. قد زاد بشكل كبير في المجموعات المعدلة ، وكانت c. albicansو s mutansستنتج أن نشاط مضادات الميكروبات ضد الخالصة: ضمن حدود هذه الدراسة ، يمكننا أن ن . إلى الجينات tio2nps٪ 5. في المقابل ، تم تقليل استنساخ تفاصيل السطح عند إضافة tio2npsهذه الزيادة مرتبطة بشكل مباشر بزيادة تركيز j bagh college dentistry vol. 26(1), march 2014 the association of oral and maxillofacial surgery and periodontics 134 the association of crevicular albumin level with the severity of periodontal destruction in chronic periodontitis patients after initial periodontal treatment raghad fadhil, b.d.s., m.sc. (1) abstract background: gingival crevice fluid (gcf) is a mixture of substances derived from serum, leukocytes, and structural cells of periodontium and oral bacteria. these substances possess a great potential for serving as indicators of periodontal disease and healing after therapy the main purpose of this study was to find if there is a difference in albumin concentration between healthy and diseased periodontal tissues and to compare between diseased group according to pocket depth materials and methods: total sample composed of 60 pockets found in 35 patients all of them had no history of any systemic disease, the samples were divided in to three main group that include two diseased groups divided according to the depth of the periodontal pocket (group i were the pocket depth less than 6mm and group ii were the pocket depth is equal or more than 6mm) and one healthy group (group iii). sampling of gcf were taken from patients in the second visits of periodontal treatment a previously weighed strips of filter paper size 30 were gently inserted in to the selected pocket depth until resistance was felt the filter paper left in place for 30 seconds and after removal they were weighed on a chemical balance. the difference between the weights of filter paper before and after absorption of exudates was calculated and each filter strips was placed in a tube containing o.3ml of normal saline then transferred and stored at -20c.on the day of analysis the samples were centrifuged at 10.000rpm for 20 minutes .the supernatant was used for assessment of albunim colorimetrically similar to that of blood. results: comparison for gingival fluid weight were shown a non significant difference in the weight between group i&ii at a p values >0.05 while there were a highly significant difference between group i&iii and between group ii&iii at p values <0.000 while comparison for albumin concentration in gingival fluid by using t-test and f test show a non significant difference for all groups at p values >0.05 intra groups correlation between albumin content in gingival fluid and periodontal parameter there were a significant negative correlation between plaque index and albumin in group i and ii while anon significant correlation in group iii also a significant and highly significant correlation were found between albumin and weight of gingival fluid in group i and ii while anon significant differences in group iii as shown in the table while there were anon significant differences between albumin content of gingival fluid and the gingival index, probing pocket depth and clinical attachment loss. conclusion: the gingival crevicular fluid is an aqueous component in which is true trasudate and inflammatory exudates after the initial periodontal treatment in which it increased in weight as the inflammation present but the concentration of albumin may became a no significantly different compared with clinically healthy gingiva. as the initial periodontal treatment took place for each patients. keywords: albumin and periodontal disease, gingival fluid, chronic periodontitis, albumin level in gingival fluid. (j bagh coll dentistry 2014; 26(1):134-137). الخالصة: ختالف بين تركيز االلبومين الموجود في السلئل اللثوي بين االصحاء والمرضى المصابين بالتهاب اللثة وماحول االسنان لقد جمعت ه الدراسة كان اليجاد االالهدف الرئيسي الجراء هذ جميع متغيرات ماحول االسنن سجلت للمقرنة بين المجاميع الثالثة ‘ عشرين عينةمراجع قسموا الى ثالث مجاميع كل مجموعة تكونت من 53جيب لثوي وجدت لدى 06العينات من للثوي كانت توضع العينة في الماء المقطر ولغرض اخذ العينة من السائل اللثوي استخدمنا شرائح من ورق الترشيح ووضعت بشكل هادئ في االخدود اللثوي وبعد اخذ العينة من السائل ا ى من موعة المرضمين الموجود في كل عينة .لقد تم ااستخدام االحصاء الوصفي والتحليلي الظهار النتائج وقد كان هناك فرق معنوي بين مجموعة االصحاء ومجالحتساب كمية االلبو كما وجد ان هنالك عالقة سلبية و االصحاءيع المرضىبين مجام من ناحية تركيز االلبومين المجموع ولكن لم يكن هنالك اي فرق المجموعة ناحية الوزن المحتسب لكمية السائل اللثوي ربما هذه النتائج تعزو الى استخدام العالج االولي والوقائي المرض اللثة قبل البدء بعملية جمع السائل اللثويقوية بين متغيرات ماحول االسنان وتلركير االلبومين في السائل اللثوي introduction gingival crevice fluid (gcf) is a mixture of substances derived from serum, leukocytes, and structural cells of periodontium and oral bacteria. these substances possess a great potential for serving as indicators of periodontal disease and healing after therapy (1). the use of gcf volume as an aid in the diagnosis of periodontal status was proposed many years ago by golub and kleinberg in 1976(2). (1)lecturer. department of periodontics, college of dentistry, baghdad university. they have demonstrated a significant relationship between gcf volume and the severity of periodontal inflammation associated with gingivitis or periodontitis. in particular, positive correlations between gcf volume and clinical parameters, such as probing pocket depth, and successful periodontal treatment have been reported (3). gingival crevicular fluid capacity to carry high moleclular weight compounds such as proteins has confirmed and that the gingival fluid is an inflammatory exudates as a result of increased capillary permeability (4) . studies have suggested that determining the level of inflammatory mediators in biologic fluids indicates inflammatory activity (10). numerous studies have j bagh college dentistry vol. 26(1), march 2014 the association of oral and maxillofacial surgery and periodontics 135 shown that biomarkers of inflammatory response are elevated in people with periodontitis compared with healthy controls (12,13) . kardeşler et al proved that clinical improvements are less apparent in diabetic chronic periodontitis patients as reflected by disease markers in gcf and by an increase in concentrations of inflammatory proteins il-6 and albumin in gcf of this patient group following initial periodontal treatment (11). mann and stofler in 1964 reported the presence of albumin in gingival fluid (7). in1985 a study was done by collection of unstimulated, resting crevicular fluid from healthy crevicular spaces (i.e. in the absence of clinically detectable inflammation) of dogs and humans was collected for 3 minutes, either in microcapillary glass tubes or with the aid of filter paper strips. quantification of proteins was done by radial immunodiffusion without the pooling of samples or by immunoelectrophoresis, without eluting from the papers. the concentrations of albumin and fibrinogen in crevicular fluid so determined proved to be significantly lower than plasma concentrations. these results strengthen the concept that capillary dynamics in healthy gingivae are similar to those in general tissue capillary beds and that gingival fluid is a plasma transudate. however, due to ever present subclinical inflammation and other factors, it is improbable that fluid from even healthy sulci is a true transudate (5,6). the main purpose of this study was to find if there is a difference in albumin concentration between healthy and diseased periodontal tissues and to compare between diseased groups according to pocket depth. materials and methods sample total sample composed of 60 pockets found in 35 patients all of them had no history of any systemic disease, they were well informed about the aim of investigation and they were free to accept or refuse to be examined all of them were selected from subjects attending periodontal department in the college of dentistry at baghdad university. the samples were divided in to three main groups that include two diseased groups divided according to the depth of the periodontal pocket (group i were the pocket depth less than 6mm and group ii were the pocket depth is equal or more than 6mm) and one healthy group(group iii) periodontal assessments the periodontal examination were performed on a dental chair, the periodontal variables were recorded on four sites (mesial, distal, buccal and lingual)for all teeth these parameters include: plaque index (pi) (silness and leo 1964), gingival index (gi) (loe 1967), probing pocket depth(ppd):is defined as the distance from the gingival margin to the most apical penetration of periodontal probe inserted in to the gingival crevice. clinical attachment loss (cal): is defined as the distance from cement enamel junction to the location of the inserted probe tip. sampling of gingival fluid for albumin analysis sampling of gcf were taken from patients in the second visits of periodontal treatment (after the patient had received supra gingival scaling and polishing and received good oral hygiene instructions in the first visit) to avoid bleeding occurrence during the collection of gingival fluid. in the first and second groups (group i and group ii) the teeth had a pocket depth more or equal to 4mm while in the third group (group iii) the gingival tissues were clinically healthy and no pocket or loss of attachment were present. prior to the sampling the teeth were thoroughly cleaned from plaque without causing damage to the gingivae. then the teeth and gingivae were carefully dried before the collection of the exudates started. a previously weighed strips of filter paper size 30 were gently inserted in to the selected pocket depth until resistance was felt the filter paper left in place for 30 seconds and after removal they were weighed on a chemical balance , the difference between the weights of filter paper before and after absorption of exudates was calculated and each filter strips was placed in a tube containing o.3ml of normal saline then transferred and stored at -20c.on the day of analysis the samples were centrifuged at 10.000rpm for 20 minutes .the supernatant was used for assessment of albunim colorimetrically similar to that of blood. statistical analysis both descriptive and inferential statistics were used. the descriptive statistics include: mean, standard deviation (sd), minimum and maximum while inferential statistics include t-test, and pearson’s (r) for correlation. results sixty (60) sites were included in the study (40 sites were had periodontal pockets equal or more than 4mm and 20 sites were clinically healthy gingiva). the descriptive statistics for periodontal parameters were as follow in tables 1,2,3,4,5,6::table (1) show the highest level of mean plaque index was found in group i as it was 1.22 http://europepmc.org/search?page=1&query=auth:%22karde%c5%9fler+l%22 http://europepmc.org/abstract/med/20845058/?whatizit_url=http://europepmc.org/search/?page=1&query=%22chronic%20periodontitis%22 http://europepmc.org/abstract/med/20845058/?whatizit_url_gene_protein=http://www.uniprot.org/uniprot/?query=il-6&sort=score j bagh college dentistry vol. 26(1), march 2014 the association of oral and maxillofacial surgery and periodontics 136 table 1: descriptive statistics for plaque index groups min max mean sd group i 0.8 1.8 1.22 0.40± group ii 0.5 1.7 0.96 0.44± group iii 0.3 0.8 0.46 0.13± in table (2), the mean of gingival index were 1.21, 1.51 and 0.47 for groups i,ii and iii respectively as shown below. table 2: descriptive statistics for gingival index groups min max mean sd group i 1. 1.6 1.21 0.21± group ii 1. 1.5 1.15 0.31± group iii 0.3 0.6 0.47 0.12± the minimum and maximum level for clinical attachment loss and probing pocket depth were in group ii as shown in table (3and 4). table3: descriptive statistics for clinical attachment loss in all groups groups min max mean sd group i 4 8 6.4 1.40± group ii 6 9 7.12 1.06± group iii 0 0 0 0 table4: descriptive statistics for probing pocket depth in all groups groups min max mean sd group i 4 5 4.4 0.51± group ii 6 9 6.15 0.81± group iii 0 0 0 0 the concentration of albumin was at maximum level in group i as it was 502µg\mg while the minimum concentration was found in group iii as it was 150 µg\mg as shown in table 5 table 5: descriptive statistics for albumin in gingival fluid mg\mg in all groups groups min max mean sd group i 168 502 402 100.73± group ii 180 382 285.13 63.44± group iii 150 320 230 50.7± the highest mean of gingival fluid was found in group i as it was 1µg\mg while the lowest mean was 0.4 µg in group ii table 6: descriptive statistics for weight of gingival fluid in µg\ mg for all groups groups min max mean sd group i 0.5 1 0.592 0.175± group ii 0.4 0.7 0.588 0.142± group iii 0.1 0.4 0.211 0.083± comparison for gingival fluid weight were shown in table (7) and there were a non significant difference in the weight between group i&ii at a p values >0.05 while there were a highly significant difference between group i&iii and between group ii&iii at p values <0.000 as shown in table (7) table 7: the difference in the gingival fluid weight for all group by using t-test groups ttest sig group i & group ii 0.807 ns group i& group iii 0.000 hs group ii & group iii 0.000 hs comparison for albumin concentration in gingival fluid by using t-test shows a non significant difference for all groups at p values >0.05as shown in table (8&9) table 8: ttest between groups for albumin content in gingival fluid table 9 shows intra groups correlation between albumin content in gingival fluid and periodontal parameter there were a significant negative correlation between plaque index and albumin in group i and ii while anon significant correlation in group iii also a significant and highly significant correlation were found between albumin and weight of gingival fluid in group i and ii while anon significant differences in group iii as shown in the table while there were anon significant differences between albumin content of gingival fluid and the gingival index, probing pocket depth and clinical attachment loss. table 9: correlation of albumin with plaque index, gingival index and weight. pearson correlation pi&al gi&al al&w al&ppd al&cal group i -0.672 (s) -0.320 (ns) -0.688 (s) 0.084 (ns) 0.673 (s) group ii -0.562 (s) 0.088 (ns) -0.739 (hs) 0.052 (ns) 0.49 (s) group iii -0.068 (ns) -0.066 (ns) -0.263 (ns) groups ttest sig group i & group ii 0.624 ns group i& group iii 0.537 ns group ii & group iii 0.785 ns j bagh college dentistry vol. 26(1), march 2014 the association of oral and maxillofacial surgery and periodontics 137 discussion the descriptive statistics for the albumin show the concentration of albumin in all groups it was lowest in the group iii (healthy group) and highest in group ii (sever pocket depth group )as the probing pocket depth was present in group ii and group i while group iii was clinically healthy but the inter group comparison for albumin content of gingival fluid by using ttest show a non significant difference between healthy group (group iii) and diseased group (group ii&i) as well as anon significant differences between group i and group ii this was may be due to initial periodontal treatment which was done before the collection of gingival fluid for all patients in group i and group ii they were had scaling and polishing and oral hygiene instructions for good plaque control one week before the collection time each site included in the study should show a gingival index score 1 and no bleeding on probing to avoid bleeding occurrence at the time of collection all this may lead to changing the constituent concentrations of gingival fluid as treatment took place for the patients since the inflammation was reduced mostly at the site of collection although there was a significant differences in the weight of gingival fluid between healthy group and other groups this is supported by shaprio et al whose found that the amount of gcf is greater when inflammation is present (9) and some times proportional to the severity of inflammation (8) which mean that the amount of fluid did not reduced after initial periodontal treatment but the concentration of albumin in group i and group ii became similar to group iii as shown in the results these results support the hypothesis that, in an early inflammatory response, the fluid is not a typical inflammatory exudates and is probably modulated by an osmotic gradient(6)the correlation between albumin in gingival crevicular fluid and periodontal parameter show a significant and a highly significant correlation with plaque index and a clinical attachment loss in group i and ii while anon significant correlation in group iii as well as there was a significant correlation of albumin with the weight of gingival fluid in group i and group ii while anon significant correlation for gingival index and probing pocket depth in all groups this was in agreement with bang and cimasoni (4) who found a non significant correlation between the concentration of proteins in gingival crevicular fluid and the severity of gingivitis, pocket depth in a conclusion the gingival crevicular fluid is an aqueous component in which is true trasudate and inflammatory exudates after the initial periodontal treatment in which it increased in weight as the inflammation present but the concentration of albumin may became a no significantly different compared with clinically healthy gingiva. as the initial periodontal treatment took place for each patients. references 1. eley bm, cox sw. proteolytic and hydrolytic enzymes from putative periodontal pathogens: characterization, molecular genetics, effects on host defenses and tissues and detections in gingival crevice fluid. periodontal 2000, 2003; 31: 105-24. (ivsl) 2. golub lm, kleinberg i. gingival crevicular fluid: a new diagnostic aid in managing the periodontal patients. oral sci rev 1976; 8: 49-54 3. talonpokia jt. changes in amount of gingival crevicular fluid after a single episode of periodontal treatment. scand j dent res1992; 100: 211-5 4. bang j, cimasoni g. total protein in human crevicular fluid. j dent res 1971; 50: 1683. 5. marcus er, jooste cp, driver hs. the quantification of individual proteins in crevicular gingival fluid. j periodontal res 1985; 20(5): 444–9 6. bickel m, cimasoni g, andersen e. flow and albumin content of early (pre-inflammatory) gingival crevicular fluid from human subjects. arch oral biol 1985; 30(8): 599-602. 7. mann wv and stoffer hr. the identification of protein components in fluid from the gingival pockets. periodontics 1964; 2: 263-6. 8. shaprio l, goldman h, bloom a. sulcular exudates flow in gingival inflammation. j periodontal 1979; 50305 9. orban je, sallard re. gingival crevicular fluid. a reliable predictor of gingival health. j periodontal 1969; 40: 231. 10. giannobile wv, beikler t, kinney j, et al. saliva as a diagnostic tool for periodontal disease: current state and future directions. periodontology 2000 2009; 50: 52–64 11. kardeşler n,çetinkalp, lappin d, kinane df. gingival crevicular fluid il-6, tpa, pai-2, albumin levels following initial periodontal treatment in chronic periodontitis patients with or without type 2 diabetes. inflammation research: official journal of the european histamine research society 2011; 60(2):143-151 12. zhong y, slade gd, beck jd, offenbacher s. gingival crevicular fluid interleukin-1beta, prostaglandin e2 and periodontal status in a community population. j clin periodontol 2007; 34: 285–93. 13. bostanci n, ilgenli t, emingil g, afacan b, han b, toz h, atilla g, hughes fj, belibasakis gn. gingival crevicular fluid levels of rankl and opg in periodontal diseases: implications of their relative ratio. j clin periodontol 2007; 34: 370–6. http://onlinelibrary.wiley.com/doi/10.1111/jre.1985.20.issue-5/issuetoc http://www.ncbi.nlm.nih.gov/pubmed?term=bickel%20m%5bauthor%5d&cauthor=true&cauthor_uid=3901983 http://www.ncbi.nlm.nih.gov/pubmed?term=cimasoni%20g%5bauthor%5d&cauthor=true&cauthor_uid=3901983 http://www.ncbi.nlm.nih.gov/pubmed?term=andersen%20e%5bauthor%5d&cauthor=true&cauthor_uid=3901983 http://www.ncbi.nlm.nih.gov/pubmed/3901983 http://europepmc.org/search?page=1&query=auth:%22buduneli+n%22 http://europepmc.org/search?page=1&query=auth:%22lappin+d%22 http://europepmc.org/search?page=1&query=auth:%22kinane+df%22 http://europepmc.org/search?page=1&query=issn:%221023-3830%22 http://europepmc.org/search?page=1&query=issn:%221023-3830%22 j bagh college dentistry vol. 33(3), september 2021 the effect of contact 18 the effect of contact time between alginate impression material and type iii dental stone on the surface properties of stone casts )3( najwah yousuf hameed ,)(2 atyaf maser alnaser ,(1)suha fadhil dulaimi https://doi.org/10.26477/jbcd.v33i3.2949 abstract background: alginate impression material is the irreversible hydrocolloid material that is widely used in dentistry. the contact time between alginate and gypsum cast could have a detrimental effect on the properties of the gypsum cast. the objective of this study is to evaluate the impact of various contact time intervals of alginate impressions & type iii dental stone on surface properties of stone cast. materials and methods: time intervals tested were 1hour, 6 hours and 9 hours. surface properties of stone cast evaluated were surface detail reproduction, hardness and roughness. surface detail reproduction was determined using cylindrical brass test block in accordance with iso 1563. surface roughness was measured by profilometer and hardness was measured by durometer (shore d). results: the detail reproduction showed significant difference (p<0.05), at 6 hr., and 9 hr. showed better results, while surface roughness significantly decreased (p<0.01) with prolonged contact time. however, surface hardness increased significantly (p<0.01) with increased contact time. conclusions: surface detail reproduction increased with increasing the contact time and this was noticed at (6, 9 hours). however, 1hour time interval showed decreased surface detailed reproduction. roughness decreased when the contact time was increased between type iii dental stone and alginate impression, whereas hardness was improved significantly with increasing contact time. keywords: alginates, surface properties, dentistry, hardness, calcium sulfate. (received: 2/6/2021, accepted: 4/7/2021) introduction in dentistry, methods of oral disease diagnosis and treatment are complemented by replicas of hard and soft tissue. those replicas are known as study models, casts or dies they are used for studying some cases in dentistry; and all of these replicas are used in the dental practice. (1) although there are several impression materials and procedures available for accurate impression making, irreversible hydrocolloids are among several impression materials that are commonly utilized in dental offices to produce stone casts (2). an alginate impression is often made during the first visit as its outcomes are necessary to form a primary diagnosis about the patients' oral health condition (4). for several years, alginate impression has become an essential material for most dental, clinical and laboratory dental techniques. the low cost and the ease of manipulation, integrated with good clinical and physical properties make alginate a popular choice among different dental practices (3). (1) assistant professor, department of prosthodontics technology, college of health and medical technology. middle technical university (mtu) baghdad – iraq (2) (3) assistant lecturer, department of prosthodontics technology, college of health and medical technology. middle technical university (mtu) baghdad – iraq suha.f.dulaimi@gmail.comesponding author: corr accurate diagnostic casts are essential to perform a multitude of functions throughout diagnosis, treatment planning and preparation for prosthodontics care (4). thus, it is of importance to understand the properties of those materials following some basic instructions so as to achieve predictable and flawless impressions and therefore avoiding repeated impression/restorations (4). alginate is composed of a powder that contains potassium or calcium sulfate and fillers as primary constituents. the commercial alginate contains some additive materials to calcium salts to improve its properties like diatomaceous earth fillers to raise its rigidity and ease mixing, tetra sodium pyrophosphate (retarder), magnesium oxide (ph modifier) as well as the setting aids like sodium fluorosilicate (5). delay pouring of alginate impression results in serious distortion due to shrinkage caused by syneresis and evaporation of water. a previous study recommended storing alginate impression up to 1 hr. in humid environment (6). another factor that affects properties of final gypsum cast is the contact time between alginate and gypsum cast during its setting, the appropriate approach to prevent or decrease abrasion of gypsum cast during removal is by separating the cast from impression before hydrocolloid dehydration that occurs due to dried alginate (7). in some occasions in clinical and https://doi.org/10.26477/jbcd.v33i3.2949 mailto:suha.f.dulaimi@gmail.com j bagh college dentistry vol. 33(3), september 2021 the effect of contact 19 laboratory dental practice delay separation of gypsum cast from alginate impression after complete setting could happened. gypsum cast and die that are used in the production of dental restorations should give strength, resistance to scratch and accurate dimensional stability. the cast model's dimensional stability is influenced by the alginate water absorption and release as well as method of handling the impression by the clinician, in addition to contact time between alginate impressions and the gypsum's product (5). the gypsum setting time (the contact time between alginate impression and poured gypsum mix) should be observed to ensure the ideal properties of final cast model. compatibility between alginate impression and gypsum product are also important for quality of cast model (7). a previous study investigated alginate impression storage time and recommended that impression must be poured immediately (8). few information about the effect of contact time between alginate and gypsum , others recommended separating cast from alginate impression before dehydration of alginate started that have detrimental effect on cast quality (9, 5). the aim of the present study was to evaluate the effect of different contact time (1hr., 6hr. 9hr.) between alginate impression material and type iii dental stone on surface details reproduction, surface roughness and hardness of stone cast. materials and methods alginate impressions (zhermack badia polesine, italy) were evaluated with dental stone type iii (zhermack badia polesine, italy) at different contact time intervals (1hr., 6hr. 9hr.) surface details reproduction: a brass cylindrical block (figure1) was fabricated with three reference lines on surface 20 μm,50 μm & 75μm in (width and depth). they were 2.5mm apart from each other according to iso 1563 (10) , the circular block had dimensions of 25mm in width and15 mm in length. figure 1: the brass cylindrical block constructed according to iso 1563 the 30 special trays were fabricated from chemical cure acrylic resin (superacreyl plus, spofa dental, markova, czech republic). two wax sheets (2.8 mm) in width were orderly lined a round the cylinder, then acrylic dough was applied above wax sheets to create special tray to carry alginate impression. the special trays were completed and perforated after setting of materials to prepare the samples. the manufacturer instructions were followed when alginate was mixed manually for 45 sec. and applied carefully in a special tray. then, the top of the cylindrical brass was covered by a glass plate (weight 1 kg) (11). setting of the impression material took 5 minutes before its removal from the cylindrical brass test. a cotton gauze moisten with ethanol was used to wipe the surface of the cylindrical test block, then washed with distilled water and kindly dried with compressed air before fabrication of each sample. mixing of dental stones was done in accordance with guidelines of the manufacturer. after that, stone mix was poured in alginate impression for cast model production. the models were separated from impression after experimental time intervals (1 hour, 6 hours , 9 hours) figure 2. figure 2: custom made perforated tray and separated cast model j bagh college dentistry vol. 33(3), september 2021 the effect of contact 20 group a, the control group, which contained (30 casts) were separated after an hour, group b, the study group, which contained (30 casts): were separated after 6 hours, and group c, which contained (30 casts) were removed following 9 hours. each group was then scanned at 1200 dpi resolution using a flatbed scanner (genix, china), using a template as a guide on the surface of the scanner. the scanned images have been saved in jpg format. evaluation of the surface detail reproduction was done by an operator who examined the images of specimens on computer monitor after x10 magnification and graded them according to scoring system from (1 to 4). the definition of the ratings was determined as follows: 1) sharp detail continuous lines 2) continuous lines, but with sharpness loss 3) line details deterioration 4) rough appearance, with loss of line continuity (12, 13). surface roughness testing of the surface roughness was done by using a profilometer (10) (talysurf 4 profilometer, taylor hobson, usa).the surface of ten specimens for each time interval was measured in 3 different locations for each specimen then the average of mean roughness was calculated to each time interval. surface hardness the surface hardness was assessed by making indentation using shore d hardness digital tester (digital hardness tester ht_6510c shore c shenzhea handsome technology g. ltd. china) which is suitable for stone type iii material. each specimen surface was exposed to three indentations in various positions, and the average hardness number of each specimen was calculated in separate manner, and the same process was performed for the other samples for each time interval. surface hardness and roughness results were analyzed with descriptive statistic, one way anova and games-howell post hoc test. results of surface detailed reproduction were converted into percentage and compared using chi-square test. results the descriptive statistics and chi-square test for surface detail reproduction of the 30 specimens was shown in table (1). the results showed that 1 hour time interval had 80% score 2 and 20% score 3. however, cast separated at 6 hours and 9 hours' time intervals showed 50% score 1 and 50% score 2 and eventually gave the best result. chi-square test showed significant differences among the groups examined (p<0.05). table 1: distributions of surface details reproduction test among time groups with chi-square test surface details reproduction (scores) time groups chisquare test one hour six hours nine hours one n 5 5 0.041 s % 50% 50% two n 8 5 5 % 80% 50% 50% three n 2 % 20% total n 10 10 10 % 100% 100% 100% table 2 showed the descriptive statistics and one way anova tests of surface roughness. the results showed that the lowest mean for surface roughness was registered at 9 hours which was (2.544), while the highest mean value was related to the 6 hours (3.209). the one way anova test between the studied groups found highly significant differences (p<0.01). games-howell test table 3 showed highly significant (p<0.01) comparing one hour with six hours and nine hours, also highly significant (p<0.01) comparing six hours with nine hours. table 2: mean distributions of surface roughness test among time groups with anova test table 3: games-howell test for surface roughness table 4 showed the descriptive statistics and one way anova test of surface hardness. the results showed that the highest mean value for hardness was registered at 9 hours which was (61.83), while the lowest mean value was related to the 6 hour time groups n mean std. d std. e range anova test min. max. one hour 10 3.209 0.001 0.0003 3.207 3.210 0.00 hs six hours 10 3.858 0.098 0.031 3.731 3.951 nine hours 10 2.544 0.096 0.030 2.430 2.651 time groups games-howell test (p-value) one hour six hours p=0.00 highly sign. (p<0.01) nine hours p=0.00 highly sign. (p<0.01) six hours nine hours p=0.00 highly sign. (p<0.01) j bagh college dentistry vol. 33(3), september 2021 the effect of contact 21 (49.27). one way anova test between the studied groups demonstrated highly significance differences (p<0.01). table 4: mean distributions of surface hardness test among time groups with anova test table 5: gameshowell test for surface hardness time groups games-howell test (p-value) one hour six hours p=0.00 highly sign. (p<0.01) nine hours p=0.00 highly sign. (p<0.01) six hours nine hours p=0.00 highly sign. (p<0.01) games-howell test table (5) showed highly significant (p<0.01) comparing one hour with six hours and nine hours, also highly significant (p<0.01) comparing six hours with nine hours. discussion the immediate pouring of alginate impressions could not always be achieved in everyday dental practices. therefore, impressions are stored in sealed bags or wrapped in paper towels with suitable humidity. without achieving such requirements, properties of the materials will be affected (14). however, if the separation of a cast from an impression is delayed, it will cause some model cast properties to be deteriorated (5). this study was conducted to determine the probable changes in cast model properties following the varying contact time between dental stone type iii and alginate impressions. the selected time intervals for the present study (1, 6, 9hr.) justified because previous study by matqezan et al. 2012 (7) not recommended 12hr. time period of contact between alginate and gypsum cast because it influences the quality of gypsum cast. the null hypothesis was rejected, the results of different periods for surface details reproduction, surface roughness and hardness showed differences among the three experimental time intervals. the surface details reproduction as in table (1) increased with the increase in contact time and this was observed at 6 and 9 hours' time interval which gave 50% at score 1 and score 2. however, 1 hour time interval resulted in 80% score 2 and 20% score 3. improvement in detail reproduction with prolonged contact time may be related to elevation in surface hardness and improved smoothness with prolonged contact time that is concluded in present study. these results were in agreement with….. (15) but disagreed with…. (5) who stated that surface details decreased with the increase in contact time and also disagreed with (11) …….who revealed that paste type alginate impression materials and type iii dental stone materials are compatible with each other and can reproduce surfaces details efficiently much better than powder type alginate with type iii dental stone material. however, surface roughness decreased when contact time increased to 9 hours and raised in 1 hour and 6 hours contact time as shown in table (2). the causative factor for this finding may be due to dehydration of stone due to prolonged contact time between the alginate impressions and the stone cast (7). a significant elevation in the surface hardness with increased contact time was recorded may be due to excess water evaporation from stone cast, in addition to smoothness of stone cast caused by decreased surface roughness with prolonged contact time found in present study . results demonstrated that there was a decrease in the scratches depth when there was an increase in the contact time as in table (4). these results were similar to the findings of ibrahim et al. 2015 (5). conclusion delay separation of stone cast from alginate impression affect surface properties variably: 1-surface detailed reproduction significantly improved at 6hr. and 9hr. time interval. 2surface roughness reduced with increased contact time up to 9hr. 3-however surface hardness increased significantly up to 9hr. conflict of interest: none. references 1. powers, j.m. and j.c. wataha, dental materials-e-book: properties and manipulation. 2014: elsevier health sciences 10th edition . 2. nandini vv, venkatesh kv, nair kc. alginate impressions: a practical perspective. j conserv dent.2008jan;11(1):37-41. time groups n mean std. d std. e range anova test mini. max one hour 10 54.96 1.076 0.340 53.3 56.3 0.00 hs six hours 10 49.27 1.274 0.403 46.6 50.6 nine hours 10 61.83 3.009 0.952 57.3 65.3 j bagh college dentistry vol. 33(3), september 2021 the effect of contact 22 3. sayed me, gangad harappa p. threedimensional evaluation of extended pour alginate impression materials following variable storage time intervals and conditions. indian j dent res. 2018 jul-aug;29(4):477486. 4. cervino, g., fiorillo, l., herford, a. s., et al. alginate materials and dental impression technique: a current state of the art and application to dental practice. marine drugs 2018 dec; 17(1):18. 5. ibrahim, a.a., m.n. alhajj, m.w. gilada, effect of contact time between alginate impression and type iii dental stone on cast model properties. rsbo revista sul-brasileira de odontologia, 2015. 12(3):239-244. 6. wadhwa ss, mehta r, duggal n, et al. the effect of pouring time on the dimensional accuracy of casts made from different irreversible hydrocolloid impression materials. contemp clin dent. 2013 jul;4(3):313-8. 7. marquezan m, jurach em, guimarães vd, et al. does the contact time of alginate with plaster cast influence its properties? braz oral res. 2012 may-jun;26(3):197-201. 8. penfold rrs, brandt wc, miranda me, et al. evaluation of dimensional stability and details reproduction of alginate molds storage in different times and temperature. braz dent sci 2018 jan/mar;21(1):37-43. 9. chen sy, liang wm, chen fn. factors affecting theaccuracy of elastometric impression materials. j dent 2004; 32:603-609. 10. international organization for standardization. dental alginate impression material. n° 1563:1990. 11. murata h, kawamura m, hamada t, et al. physical properties and compatibility with dental stones of current alginate impression materials. j oral rehabil. 2004 nov;31(11):1115-22. 12. dulaimi, s.f. and z.n. al-wahab. the effect of disinfectants on the surface quality of irreversible hydrocolloid impression material and gypsum cast. iraqi national journal of nursing specility. 2012; 25(1): 95-100. 13. taylor rl, wright ps, maryan c. disinfection procedures: their effect on the dimensional accuracy and surface quality of irreversible hydrocolloid impression materials and gypsum casts. dent mater 2002; 18:103-110. 14. nassar, u., aziz, t., flores-mir, c. dimensional stability of irreversible hydrocolloid impression materials as a function of pouring time: a systematic review. j prosthet dent , 2011; 106(2): 126-133. 15. ibrahim aa, alhajj mn, khalifa n, et al. does 6 hours of contact with alginate impression material affect dental cast properties? compend contin educ dent. 2017 jun;38(6):e1-e4. المستخلص قابلة للعكس تستخدم على نطاق واسع في طب األسنان. يمكن أن يكون لوقت الخلفية: مادة االنطباع الجيني هي مادة غرواني مائي غير المختلفة التالمس فترات تأثير تقييم هو الدراسة هذه من الهدف الجبس. قالب خصائص على ضار تأثير والجبس الجينات بين التالمس ت وحجر األسنان من النوع الثالث على الخصائص السطحية للحجر المصبوب.المواد والطرق: كانت الفترات الزمنية النطباعات األلجينا ساعات. تم تقييم الخصائص السطحية للصب الحجري وهي إعادة إنتاج تفاصيل السطح والصالبة 9ساعات و 6المختبرة ساعة واحدة و . تم قياس خشونة iso 1563باستخدام كتلة اختبار أسطوانية من النحاس األصفر وفقًا لمعيار والخشونة. تم تحديد استنساخ تفاصيل السطح (.shore dالسطح بمقياس بروفيلومتر وتم قياس الصالبة بواسطة مقياس التحمل ) نما تقل خشونة السطح معنوياً ساعات. أظهر نتائج أفضل. بي 9ساعات و 6( ، عند p <0.05النتائج: أظهر التكاثر التفصيلي فرقاً معنوياً ) (p <0.01( مع زيادة زمن التالمس. ومع ذلك ، زادت صالبة السطح بشكل كبير )p <0.01 مع زيادة وقت التالمس.االستنتاجات: زيادة ) ومع ذلك ، . 2والنتيجة 1٪ في الدرجة 50ساعات( مما يعطي 9، 6استنساخ تفاصيل السطح مع زيادة وقت التالمس وقد لوحظ ذلك في ) . خشونة انخفض عند زيادة وقت التالمس بين حجر األسنان من النوع الثالث 3٪ درجة 20و 2٪ درجة 80أظهر الفاصل الزمني لمدة ساعة .وانطباع األلجينات بينما تحسنت الصالبة بشكل ملحوظ مع زيادة وقت التالمس articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. 27mena f.doc j bagh college dentistry vol. 28(3), september 2016 asthma and inhaled pedodontics, orthodontics and preventive dentistry 159 asthma and inhaled corticosteroid effect on the dental arch morphology in children meena o. abdul wadood, b.d.s., m.sc. (1) zainab a.a. al-dahan, b.d.s., m.sc. (2) abstract background: asthma has an influence on craniofacial development. recently evidences show that there is an association between oral health problems and chronic lung disease. the present study was designed to estimate the changes in arch dimension measurements among asthmatic children aged 12 years old who were collected from alzahra center advisory for allergy and asthma and compare them with the non-asthmatic children of the same age and gender. material and methods: fifty children (25 asthmatic and 25 nonasthmatic children) were included for the odontometric measurement. for both upper and lower study models, photographs were taken using special photographic apparatus for each child, and the statistical analysis were done by using spss version 19. for permanent dentition, two liner measurements were utilized for each dental arch including width and length. results: the results of the current research revealed that the mean values of dental arch dimensions, width and length; for both maxillary and mandibular dental arches among asthmatic children were lower as compared to non asthmatic children in both genders. conclusions: the findings of the present study showed that asthma and inhalation treatment in asthmatic children played an important role to minimize odontometric measurement including dental arch dimensions. keywords: asthma, dental arch dimensions, inhaled corticosteroid. (j bagh coll dentistry 2016; 28(3):159-166). introduction the association between airways obstruction and dental malocclusion and abnormal development of the cranial-facial complex is still a matter of concern from about a century; asthma and allergic rhinitis are most common diseases which obstruct airways (1). the airway patency is regarded as essential factor for the normal growth and development of the craniofacial and nasomaxillary structures (2). many studies had been done on the asthma effects on dentoalveolar arches; however the results of these studies were diverse to each other (3-9). bresolin et al. (3) found high prevelance of retrognathism of both upper and lower jaws among allergic children. principato (4) reported that smaller and narrower maxilla were found among oral respiration. kairaitis et al. (5) peltomaki (8) illustrated that asthmatic patients had narrowing of both upper and lower arches at the level of canines and first molars with a higher prevalence of posterior cross-bite. solow and sandham (6) observed that patients with chronic asthma symptoms could present with dysregulation in the growth and development of the orofacial structures, including narrowing of the maxilla and lower development of the mandible. faria et al. (7) represented in their study the presence of association between dentofacial anomalies and asthma. (1)assist. lecturer. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad. (2)professor. department of pedodontics and preventive dentistry. college of dentistry, university of baghdad kumar and nandlal (9) reported that asthmatic children under regular medication of inhaled corticosteroid (ics) were observed to have narrower arches, deeper palate and higher frequency of cross bite as compared to those under irregular medication and also they found the same findings as compared the asthmatic to the non‑asthmatics in 10 to 12 years old. gungor and turkkahraman (10), found statistically significant differences between patients with airway problems and control groups in maxillary skeletal morphology that including shorter maxillary length in sagittal plane and narrower maxillary arch and higher palatal vault in transversal plane. on the other hand, contrary to this explanation, longer arches accompanied broader arches were the cases in the study conducted by hojensgaard and wenzel (11), shanker et al (12), as they found there was no relationship between palatal arch width and respiratory function in asthmatic children. the effects of the respiratory tract allergies on the dental occlusion in patients who diagnosed as having allergic rhinitis and /or asthma was studied by bezzo (13), the results of this study revealed non-significant differences between the study and control groups in over jet and overbite, but higher percentages of anterior cross-bite (6.8%) as well as posterior cross-bite (9.5%) as compared to the control group (2.7%) and (4.4%) respectively. the width of dental arch is determined by measuring distance between corresponding contra lateral teeth (14), which includes: j bagh college dentistry vol. 28(3), september 2016 asthma and inhaled pedodontics, orthodontics and preventive dentistry 160 1-inter-canine distance: it is the distance between cusp tips of the right to the left permanent canines in transverse dimension (15). generally, many researchers used cusp tip of canine as a landmark to measure the inter-canine distance (16-22). many studies observed that inter-canine distance did not change after age 13 and 16 years in both females and males respectively with a considerable individual variation (23-24). 2-inter-molar distance of permanent first molar: it is the distance between mesio-buccal cusp tips of the right permanent first molars to the left one in transverse direction, many researchers used inter-molar distance to determine growth as well as effects of genetic and environmental factor on dental arch dimension, it is also used for gender differentiation (25). different landmarks had been used to measure inter-molar distance; some studies used the distobuccal cusp tip (26-27), while central fossa was employed by mohammad (25). some researchers used the mesio-lingual cusp tip (28-29). other investigators utilized the mesio-buccal cusp tip (3032), and other investigators utilized central fossa in upper arch and disto-buccal cusp tip in the lower arch (33). 3-inter-molar distance of permanent second molar: it is the distance between the right and the left permanent second molars in transverse direction, different landmarks used to determine this distance, some studies used mesio-lingual cusp tip (34), while others used mesio-buccal cusp tip (16). many researchers used disto-buccal cusp tip (18, 19, 31). lindstron (35) reported minimal increases in the permanent inter-molar width occur between ages 9-19 years. on the other hand, ward et al. (36), reported that the inter-molar widths decreased between 11 and 14 years old among united king dom children. the dental arch length includes: 1. anterior arch length: the definitions of this distance vary between different studies depending on different landmarks. some investigators defined it as a vertical distance from the foremost point of the central incisor to the straight line between the distal surfaces of the canine (17). other investigators define it as a distance from mid way between the incisal edges of central incisors to the inter-canine distance at the cusp tip (37-39). 2. molar vertical distance: merz et al. (40), defined it as the shortest distance from a line connecting the distal surfaces of the first permanent molars to the labial surfaces of the most anterior teeth in the arch, different anatomical landmarks had been used for anterior teeth, many researchers used midpoint of line joining the mesial edges of central incisors or midpoint between the two central incisors (17, 32, 38, 41). for posterior teeth landmarks, some researchers used the distal surface of first permanent molar (42), and some other studies utilized the mesio-buccal cusp tip of first permanent molar (19, 43). 3. total arch length: it is defined as a distance between the mid-incisal edges to the midpoint of a line joining the disto-buccal cusps of the second molars (17-18), while other researchers defined it as a distance between the inter–incisal point to the mid distance of the maxillary and mandibular inter–second molar width at the mesio-buccal cusps (16,39). louly et al. (44), found a significant increase in the maxillary anterior segment length from 10-12 years, while an insignificant increase in maxillary arch total length from 9 to 12 years and a little decrease in mandibular arch total length. measurement methods of dental arch dimensions: direct method; indirect method; travel microscope; wax print; photosteriometry; occlusogram; the reflex metrograph optical plotter; steriolethography; dental cast; radiographs; holography; laser scanner and photography of study models (21). materials and methods this study was conducted among asthmatic children in comparison to nonasthmatic children matching with age and gender in baghdad city, examination started at the 20 of december 2013 till the end of march 2014. the sample of this study involved one age groups 12 years). the samples were collected from al-zahra center advisory for allergy and asthma, while the non asthmatic children were randomly selected from different baghdad’s school. the criteria for selecting the samples for the odontometric measurements included (45): all the permanent teeth might erupt, with exception of the third molar. the odontometric measurements include: 1-production of the dental casts: the upper and lower impressions were taken to every child (46). 2-pouring the cast: a suitable amount of dental stone was used immediately to pour the impressions to avoid any dimensional changes (47). j bagh college dentistry vol. 28(3), september 2016 asthma and inhaled pedodontics, orthodontics and preventive dentistry 161 3-standardization of dental casts photographs: photographic apparatus was used for standardization; this photographic apparatus was designed by hasan (21). 4-dental cast photographic technique certain selected tooth-related points in an occlusal view were carefully marked bilaterally with a pen in the maxillary and mandibular study casts to facilitate the identification of the landmarks that would be used for measuring dental arch dimensions (21). dental cast landmarks according to hasan (21), ali (22), the dental cast landmarks include: 1. incisal point: the point in the midway between the incisal edges of the two central incisors. 2. canine point: the cusp tips of the right and left permanent canines. 3. mesio-buccal cusp tips of the permanent first molars point: the mesio-buccal cusp tips of the right and left permanent first molars. 4. disto-buccal cusp tips of the permanent second molars point: the disto-buccal cusp tips of the right and left permanent second molars. cast orientation this procedure was performed by putting the dental cast in surveyor base then the cast put on a movable horizontal plate of the apparatus and adjusted to attach the translucent plastic plate in a way through which the incisal or occlusal surface segment plane attached to translucent plastic plate and parallel to the arm of the camera container. taking dental cast captures: after identifying landmarks and orientation of each dental cast, the photographic capture views of cast were produced as follow: occlusal surfaces of whole arch view was standardized by overlapping of the two cross lines; lines a and b, whereas line a should overlap along the median palatal raphe of cast; median palatal line {mpl} for the maxilla. in addition, the mirror image of mpl was transferred to the mandibular cast and line b should overlap to transverse line that was tangent to the distal edges of the two second molars for maxilla and mandible respectively (21). before taking a picture, it was necessary to set a reference millimetric scale in correspondence to the occlusal surface of the tooth (for each capture), by means of this metric scale, the calibration of each image dimension could be prepared (21). figure (4) measurements on the photographs were performed with the autocad software to calculate linear measurements; the linear measurements were divided by scale to overcome the magnification (22). dental cast photograph analysis: measurements of dental cast according to al hadithy (19), hasan (21) were involved: figure (1). 1-dental arch width: the dental arch width includes: inter-canine distance ( i c d ) . inter-first molar distance (ifmd). -inter-second molar distance (ismd) . 2-dental arch length: the dental arch length includes: anterior arch length (aal). -molar-vertical distance (mvl). -total arch length (tal). figure 1: linear measurements of dental arch width and length. the statistical analysis was performed by using spss version 19. the descriptive statistics was used including mean and sd (standard deviation). the independent samples t-test was performed to analyze and determine the differences of the measurement values between the study and control groups. results the maxillary dental arch width for asthmatic and nonasthmatic children is illustrated in table (1). concerning icd and ifmd, data showed that the mean values were found to be highly significantly lower among asthmatic than nonasthmatic children (p<0.01). concerning ismd, results revealed that the mean value among asthmatic children was found j bagh college dentistry vol. 28(3), september 2016 asthma and inhaled pedodontics, orthodontics and preventive dentistry 162 to be lower than non-asthmatic children with statistically significant difference (p<0.05). concerning gender differences in asthmatic group, data analysis of the mean values of all icd, ifmd and ismd were found to be higher among boys than girls, with statistically not significant difference for icd (p>0.05), while for ifmd the difference was significant (p<0.05) and for ismd the difference was highly significant (p<0.01). similar results were noticed concerning gender differences in non-asthmatic group except for ifmd the difference was not significant (p>0.05). the mandibular dental arch width for asthmatic and non-asthmatic children is illustrated in table (2). concerning icd and ifmd, data showed that the mean values were found to be highly significantly lower among asthmatic than nonasthmatic children (p<0.01). concerning ismd, results revealed that the mean values among asthmatic children were found to be lower than non-asthmatic children with statistically significant difference (p< 0.05). concerning gender differences in asthmatic children, data analysis reported that the mean values of all icd, ifmd and ismd were found to be higher among boys than girls with statistically highly significant difference for icd and ifmd (p<0.01), while for ismd the difference was not significant (p>0.05). similar results were noticed concerning gender differences in non-asthmatic children except for ifmd the difference was not significant (p>0.05) and for ismd the difference was statistically significant (p<0.05). the maxillary dental arch length for asthmatic and non-asthmatic children is illustrated in table (3). concerning aal, results reported that the mean value was found to be highly significantly lower among asthmatic than nonasthmatic children (p<0.01). for mvd, data revealed that the mean value among asthmatic children was found to be lower than non-asthmatic children group with statistically non-significant difference (p>0.05). concerning tal, results revealed that the mean value among asthmatic children was found to be lower than non-asthmatic children with statistically highly significant difference (p<0.01). concerning gender differences in asthmatic and non-asthmatic children, data analysis reported that the mean value of all aal, mvd and tal were found to be higher among boys than girls, with statistically highly significant difference (p<0.01), except mvd in asthmatic children, the difference was not significant (p>0.05). the mandibular dental arch length for asthmatic and non-asthmatic children is illustrated in table (4). the results of aal showed that the mean value was found to be lower among asthmatic than nonasthmatic children with statistically non -significant difference (p>0.05). for mvd data revealed that the mean value among asthmatic children was found to be lower than nonasthmatic children with statistically highly significant difference (p<0.01). the results of tal, results revealed that the mean value among asthmatic children was found to be lower than non-asthmatic children with statistically highly significant difference (p< 0.01). comparison between genders, the results illustrated that the mean values for all aal, mvd and tal were found to be higher among boys than girls among asthmatic children with statistically highly significant difference (p<0.01). while among non-asthmatic children the results reported statistically non-significant difference (p>0.05). table 1 maxillary arch width (mm) among asthmatic and non-asthmatic children by genders. variables genders asthmatic non-asthmatic statistical difference n mean s.d. n mean s.d. t-test df p-value icd boys 12 32.34 1.06 12 34.73 1.13 5.32 22 0.000 ** girls 13 31.99 0.63 13 34.44 1.44 5.57 24 0.000** total 25 32.16 0.86 25 34.58 1.29 7.78 48 0.000 ** ifmd boys 12 49.32 ▲ 1.98 12 51.37 1.44 2.91 22 0.008** girls 13 47.67 1.68 13 51.32 1.86 5.25 24 0.000** total 25 48.46 1.98 25 51.35 1.64 5.62 48 0.000** ismd boys 12 53.92 ▲▲ 1.78 12 55.40 ▲▲ 0.65 2.70 22 0.013** girls 13 51.26 0.46 13 51.93 0.91 2.37 24 0.026 * total 25 52.54 1.84 25 53.39 1.93 1.98 48 0.050 * (non sig. at p>0.05;*s: sig. at p<0.05; ** hs: highly sig. at p<0.01 between asthmatic and nonasthmatic children), (▲p<0.05 between boys and girls; ▲▲p<0.01 between boys and girls), n =number. j bagh college dentistry vol. 28(3), september 2016 asthma and inhaled pedodontics, orthodontics and preventive dentistry 163 table 2: mandibular arch width (mm) among asthmatic and non-asthmatic children by genders variables genders asthmatic non-asthmatic statistical difference n mean s.d. n mean s.d. t-test df p-value icd boys 12 25.75 ▲▲ 1.47 12 27.58 ▲▲ 1.51 3.01 22 0.006 ** girls 13 24.17 1.08 13 25.70 0.77 4.17 24 0.000 ** total 25 24.93 1.49 25 26.60 1.50 3.95 48 0.000 ** ifmd boys 12 42.69 ▲▲ 1.82 12 46.28 1.83 4.81 22 0.000 ** girls 13 40.54 0.56 13 45.74 1.05 15.80 24 0.000 ** total 25 41.57 1.70 25 46.00 1.47 9.85 48 0.000 ** ismd boys 12 50.01 2.75 12 51.32 ▲ 1.80 1.38 22 0.182 girls 13 49.20 1.58 13 50.13 0.97 1.80 24 0.084 total 25 49.59 2.21 25 50.70 1.53 2.06 48 0.044 * (non sig. at p>0.05;*s: sig. at p<0.05; ** hs: highly sig. at p<0.01 between asthmatic and nonasthmatic children). table 3: maxillary arch length (mm) among asthmatic and non-asthmatic children by genders variables genders asthmatic non-asthmatic statistical difference n mean s.d. n mean s.d. t-test df p-value aal boys 12 8.50 ▲▲ 0.99 12 9.29 ▲▲ 0.45 2.50 22 0.020 * girls 13 6.85 0.53 13 8.55 0.47 8.69 24 0.000 ** total 25 7.65 1.14 25 8.91 0.59 4.93 48 0.000 ** mvd boys 12 27.01 1.73 12 28.88 ▲▲ 2.02 2.44 22 0.023 * girls 13 26.07 1.24 13 26.12 0.95 0.12 24 0.907 total 25 26.52 1.54 25 27.45 2.08 1.79 48 0.080 tal boys 12 43.42 ▲▲ 2.41 12 44.32 ▲▲ 1.32 1.13 22 0.272 girls 13 40.88 0.71 13 43.25 0.33 10.98 24 0.000 ** total 25 42.10 2.15 25 43.76 1.07 3.47 48 0.001 ** (non sig. at p>0.05;*s: sig. at p<0.05; ** hs: highly sig. at p<0.01 between asthmatic and nonasthmatic children. table 4: mandibular arch length (mm) among asthmatic and non-asthmatic children by genders variables genders asthmatic non-asthmatic statistical difference n mean s.d. n mean s.d. t-test df p-value aal boys 12 6.30 ▲▲ 0.66 12 6.32 1.08 0.07 22 0.946 girls 13 5.28 0.49 13 6.11 0.71 -3.46 24 0.002 ** total 25 5.76 0.76 25 6.21 0.89 -1.88 48 0.081 mvd boys 12 23.40 ▲▲ 1.49 12 24.59 1.22 2.14 22 0.044 * girls 13 21.20 0.75 13 24.26 0.64 11.15 24 0.000 ** total 25 22.26 1.60 25 24.42 0.96 5.81 48 0.000 ** tal boys 12 39.17 ▲▲ 1.88 12 40.38 1.33 1.83 22 0.081 girls 13 37.08 1.39 13 39.83 1.19 5.42 24 0.000 ** total 25 38.08 1.93 25 40.10 1.26 4.37 48 0.000** (non sig. at p>0.05; *s: sig. at p<0.05; ** hs: highly sig. at p<0.01 between asthmatic and nonasthmatic children). discussion the index age twelve years was selected in the present study as it is still a proper time for prediction of arch dimension and they are also considered as a static stages as the width in the region of the permanent first molars gradually increase and attain a stable condition about 12 years of age (48), and the width in the inter canine region of both arches gradually decrease between the ages of 10 and 12 with no change after that (49). the current study didn't depended in the odontometric analysis on the traditional casts by j bagh college dentistry vol. 28(3), september 2016 asthma and inhaled pedodontics, orthodontics and preventive dentistry 164 using dental vernier particularly due to problems of casts storage in terms of space and cost, and the risks of damage. thus instead of, an alternative method to record the study models in a digital format was needed as an integral part of the modern dentistry practice through which data could be saved on a personal computer (43). therefore digital photography was used in this study, because the resolution of the software program in this study could reach up to more than 0.001mm as compared to the measurement of the manual and digital calliper that reaches up to only to 0.1 mm and 0.01mm respectively, additionally the particular software program facilitates the ability to enlarge the digital models without changing the real size of teeth. furthermore, the measurements on the digital casts are also expected to be generally reliable and more precise, especially when reaching each point on the digital casts seemed to be easier to do (21). the clinical findings of the current study concluded that the mean values of dental arches width and length for both maxillary and mandibular dental arches among asthmatic children were lower as compared to non asthmatic children in both genders. these results were in agreement with principato (4), kairaitis et al. (5), solow and sandham (6), faria et al. (7), peltomaki (8), kumar and nandlal (9), gungor and turkkahraman (10), and in disagreement with hojensgaard and wenzel (11), shanker et al. (12). these findings could be explained by the fact that patients with chronic asthma symptoms could appear with resistance elevation of the airways lower part with gas-trapping in the chest (50) , the different mechanism of breathing which correlated with these changes could lead to cervical respiratory muscles shortening which might change head and cervical spine posture (51, 52), as a result this relationship between head posture and breathing difficulties might cause dysregulation in the growth and development of the orofacial structures, including narrowing of the maxilla and lower development of the mandible (6, 53), this abnormal development had been explained by changes in head and tongue position and muscular balance (6), because the extended head posture, soft tissue stretching and the tongue lowered from contact with the palate and protruded to provide a greater oral airway as seen in response to an obstructive resistant airway, all of these factors might cause slight backward and downward forces exerted by the soft tissue layer on the facial skeleton thereby restraining the forward and increasing the downward component of the maxillary and mandibular growth relative to the cranial base (54), so asthma cause functional changes of the oralmaxillary muscles that can alter the normal development of dental occlusion (55). the change in the dentoalveolar morphology which seen in asthmatic children can be summarized as result of a complex combination of the disease, medication and associated mouth breathing (56). mouth breathing in allergic individuals is believed to be the primary factor in development of class 2 division 1 malocclusion. however, in this study all asthmatics were observed to have class 1 molar relation, this result was in agreement with kumar and nandlal (9), that could be explained by the fact that the mouth breathing might associated with all classes of malocclusion, however the occurrence of various types of malocclusion in allergic and mouth breathing subjects does not indicate mouth breathing itself as a primary cause (3, 9). the outcome of the present study showed that the maxillary dental arch is larger in all dimensions of the width and length than the mandibular dental arch in both gender among asthmatic and non-asthmatic children which confirm the accepted view that the maxillary dental arch is larger in all dimensions than the mandibular counterpart and this is consistent with the principle that the maxillary dental arch overlaps the mandibular dental arch (19, 22, 57). the results in the present study reported larger mean values of both maxillary and mandibular arches width at ifmd, ismd in addition to mandibular icd in boys than in girls, these findings are in line with those obtained in other studies (21, 24, 58, 59).furthermore this study revealed that the length of maxillary and mandibular dental arches among boys were larger in all dimensions mean values than girls, this in accordance with other studies (17, 60). this might be attributed to the smaller and smoother bony ridge and alveolar processes in girls than in boys and due to physical characteristics and strongest musculature in males which play role in facial development (19,60). while the findings of the current study were in disagreement with other studies which concluded that there were no such differences between genders in the dental arches (36,61), this disagreement could be due to ethnic differences, sample size and /or selection criteria. in conclusion, the findings of this research demonstrated the clear need to establish health programs for early diagnosis and management of airway obstructive disorders in order to avoid certain complications such as the changes in the development of the dentoalveolar morphology. j bagh college dentistry vol. 28(3), september 2016 asthma and inhaled pedodontics, orthodontics and preventive dentistry 165 refrences 1. lopatiené k, babarskas a. malocclusion and upper airway obstruction. medicine 2002; 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8(2): 926. 59. al-khawaja nfk. alveolar base and dental arch widths with segmental arch measurements in different classes of malocclusions (a comparative study). a master thesis, college of dentistry. baghdad university, baghdad-iraq, 2010. 60. al-zubair nm. dental arch asymmetry. eur j dent 2014; 8(2): 224-8. 61. nojima k, mclaughlin r, isshiki y, sinclair p. a comparative study of caucasian and japanese mandibular clinical arch form. angle orthod 2001; 71:195-200. dhaffar.doc j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 102 immunohistochemical evaluation of fhit and wwox expression in normal oral mucosa, oral epithelial dysplasia and oral squamous cell carcinoma dhaffar alwan majbil, b.d.s. (1) muna s. merza, b.d.s., m.sc., ph.d. (2) abstract background: oral squamous cell carcinoma is the most prevalent malignant neoplasm of the oral cavity which results from accumulated genetic and epigenetic alterations. it is not always inexorable and may be reversible if early intervention in the process can occur to prevent further genetic mutation and disease progression. the fhit gene is a tumor suppressor gene located in fra3b region which is the most active common fragile site, where dna damage leading to aberrant transcripts and translocations frequently occur. the wwox is a tumor suppressor gene that plays a central role in tumor suppression through transcriptional repression and apoptosis, with its apoptotic function the more prominent of the two. this study aimed to evaluate and compare the immunohistochemical expression of fhit and wwox in normal oral mucosa, oral epithelial dysplasia and oral squamous cell carcinoma and to correlate the expression of the mentioned markers with the clinicopathological features and to show the expression of studied markers with each other. materials and methods: fifty formalin-fixed, paraffin embedded tissue blocks (10 cases of normal oral mucosa, 19 cases of oral epithelial dysplasia, and 21 cases of oral squamous cell carcinoma) were included in this study. immunohistochemical staining was performed using anti fhit polyclonal antibody, and anti wwox polyclonal antibody. results: positive ihc of fhit was detected with high score in all cases of nom, 16 cases (84%) of oed and 18 cases (86%) of oscc. for wwox expression positive ihc detected with high score in all cases (100%) of nom, 14 cases (74%) of oed and 15 cases (71%) of oscc. there was statistically highly significant correlation of both markers in oed and non significant correlation in oscc, with significant differences among studied groups. conclusions: these results signifying both markers cooperative tumor suppressive role and potential pathological transition from normal oral mucosa to dysplastic epithelium and subsequently cause malignant oral lesions. keywords: nom, oed, oscc, fhit, wwox. (j bagh coll dentistry 2014; 26(4):102-107). الخالصھ ھذا التحول لیس بالعملیة . ةنتج من تراكم التغیرات الوراثیة والتغیرات المتعاقبة العارضیسرطان الفم الحرشفي ھو اكثر انواع االورام الخبیثة حدوثا في التجویف الفمي : الخلفیھ التي تعتبر ) fra3b(ھو جین مثبط للورم ویقع في منطقة ) fhit(ان جین .تقدم المرض الصعبة حیث یمكن استرجاعھ اذا تم التدخل مبكرا لمنع الطفرات الوراثیة المتكررة ومنع ھو جین مثبط ) wwox(ان جین .والتي یحصل فیھا اصابة الحامض النووي المؤدیة الى استنساخ وتبدل مواقع جینیة متكررة الحدوث ةاكثر منطقة في الجین معروفة بالھشاش .اخماد الورم عن طریق تفعیل عملیة النسخ الجیني وتنظیم عملیة موت الخالیا المنظم والتي تعتبر الطریقة االھم لتثبیط الورم للورم و یلعب دورا مركزیا في , سرطان الفم الحرشفي في الغشاء الفموي الطبیعي والحثل النموي الطالئي الفموي و) wwox(و ) fhit(یم ومقارنة االظھار المناعي النسیجي الكیمیائي لـ یتق :اھداف الدراسھ .االخر ربط االظھار الخاص بھذه المؤشرات الحیاتیة مع الصفات السریریة المرضیة وكذلك االظھار الخاص بالمؤشرات الحیاتیة المدروسة مع بعضھاو للحثل النموي الطالئي اقالب 19, قوالب للغشاء الفموي الطبیعي 10.(في شمع البارافین ابالفورمالین ومطمور امثبت انسیجی اشملت ھذه الدراسة خمسین قالب :المواد وطرق العمل )wwox(وكذلك ) fhit(صبغ المقاطع بصبغة المناعة النسیجیة الكیمیائیة باستخدام المضادات الحیویة لل تم .)لسرطان الخالیا الحرشفیة اقالب 21الفموي وكذلك للحثل النموي الطالئي %) 84(حالة ) 16(وفي , %) 100(ن ایجابیا وبتصنیف عال في جمیع حاالت الغشاء الفموي الطبیعي كا) fhit(ان االظھار المناعي الصبغي لل : النتائج ) 14(ي وفي جمیع حاالت الغشاء الفموي الطبیع اایجابیا والتصنیف عالی) wwox(بینما كان االظھار المناعي الصبغي لل .للسرطان الحرشفي الفموي %) 86(حالة ) 18(الفموي و احصائیا لكال المؤشرین الحیویین في الحثل عالیة كانت ھنالك عالقة معنویة من السرطان الفموي الحرشفي%) 71(حالة ) 15(من الحثل النموي الطالئي الفموي و%) 74(حالة .لھما بین المجامیع المدروسةمع اختالفات معنویة ,النموي الطالئي الفموي وعالقة غیر معنویة في سرطان الخالیا الحرشفیة الفموي بالنتیجة یؤدي الى و على دورھما الممیز والمتالزم في تثبیط التحول الورمي من غشاء فموي طبیعي الى حثل نموي طالئي النتائج المذكوره لكال المؤشرین الحیویین دلت :االستنتاجات .اورام فمویة خبیثة introduction the most common oral cancer of epithelial origin is oral squamous cell carcinoma (oscc), corresponding to almost 95% of all lesions and to about 38% of malignant tumors of the head and neck (1). it remains a lethal disease in over 50% of the cases diagnosed annually, due mostly to late detection of advanced stage cancer (2). the transition from normal oral epithelium to oral dysplasia and cancer results from accumulated genetic and epigenetic alterations (3). (1) master student. department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. the best-known precursor lesion is epithelial dysplasia, which is histologically detectable and often presents clinically as white or red mucosal patches called leukoplakia and erythroplakia (4). oral squamous carcinogenesis is a multistep process in which multiple genetic events occur that alter the normal functions of oncogenes and tumor suppressor genes. this can result in increased production of growth factors or numbers of cell surface receptors, enhanced intracellular messenger signalling, and/or increased production of transcription factors. in combination with the loss of tumor suppressor activity, this leads to a cell phenotype capable of increased cell proliferation, with loss j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 103 of cell cohesion, and the ability to infiltrate local tissue and spread to distant sites (5). common fragile sites are chromosome regions which observed in metaphase chromosomes. those genes in these regions are more susceptible to breakage, rearrangements and deletions than other genes and played an important role in the carcinogenesis (6-7). the fragile histidine triad (fhit) and the ww-domain oxidoreductase gene (wwox) are tumor suppressor genes that encompass the fra3b and fra16d fragile sites at chromosomes 3p14.2 and 16q23.3, respectively (8). fragile histidine triad protein is knowing to play a role in the process of neoplastic transformation. it has been demonstrated that fhit gene inactivation is manifested by a lack or very low concentration of fhit protein in tissues collected from tumours in many organs, including head, neck, breast, lungs, stomach or large intestine (9). it was indicated that loss of fhit protein not only correlated with tumour aggressiveness but also was detected in pre-cancerous lesions, pointing out the possible importance of the fhit gene in the initiation of cancer (10). wwdomain-containing oxidoreductase is an enzyme that in humans is encoded by the wwox gene. ww domain-containing proteins are found in all eukaryotes and play an important role in the regulation of a wide variety of cellular functions such as protein degradation, transcription, and rna splicing. this gene encodes a protein which contains 2 ww domains and a short-chain dehydrogenase/reductase domain (srd) ( 11). the nature of the various proteins that the wwox protein can interact with, such as c-jun, tnf, p53, p73, ap2gamma, and e2f-1, suggests that wwox plays a central role in tumor suppression through transcriptional repression and apoptosis, with its apoptotic function the more prominent of the two( 12). poor prognosis or unfavorable clinical outcome in patients is associated with low or absent expression of ww domain-containing oxidoreductase (wwox) protein in cancer specimens (13). this study aimed to evaluate and compare immunohistochemical expression of fhit and wwox in normal oral mucosa, oral epithelial dysplasia and oral squamous cell carcinoma, correlate the expression of the mentioned markers with the clinicopathological features and to show the expression of studied markers with each other. materials and methods fifty formalin-fixed, paraffin embedded tissue blocks (10 cases of normal oral mucosa, 19 cases of oral epithelial dysplasia, and 21 cases of oral squamous cell carcinoma) were included in this study dated from (1980 till 2013), were obtained from the archives of the department of oral & maxillofacial pathology/ college of dentistry/ university of baghdad; al-shaheed ghazi hospital/ medical city / baghdad; and al kadhimiya teaching hospital. after histopathological reassessment of haematoxylin and eosin stained sections for each block, an immunohistochemical staining was performed using anti fhit polyclonal antibody, and anti wwox polyclonal antibody. results positive fhit immunostaining was detected as brown cytoplasmic expression. diffuse positive immunostaining of fhit was detected with high score in all cases (100%) of nom. for oed result showed that score iv (diffuse positive staining) was found in 16 cases (84.12%), while remaining cases distributed among score i (negative), ii(sporadic positive staining ) and iii(focal positive staining) with one case (5.26%) for each score. concerning the degree of fhit expression in oscc, result showed that score iv was found in 18 cases (85.71%) , followed by score i(negative) in 2 cases (9.52%) and one case (4.76%) with score ii. fig (1,2,3). figure 1: positive cytoplasmic expression of fhit in nom(400x). j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 104 figure2: positive cytoplasmic expression of fhit in mild oed (400x). figure 3: positive cytoplasmic expression of fhit in moderate differentiated oscc (400x). positive wwox immunostaining was detected as brown cytoplasmic or cytoplasmic with nuclear expression. according to the degree of expression all cases (100%) of nom showed score iii (strong positive staining).for oed the result showed that score i ( negative) was found in 2 cases (10.53%) ,score ii (weak positive) 3 cases (15.79%) and score iii (strong positive) 14 cases (73.68%). concerning degree of expression of wwox in oscc, result revealed that majority of cases were score iii 15 cases (71.43%) followed by score i and ii both found in 3cases (14.29%). fig (4,5,6). figure 4: positive cytoplasmic expression of wwox in nom (400x). figure 5: positive cytoplasmic and nuclear expression of wwox in sever oed (400x). figure 6: positive cytoplasmic and nuclear expression of wwox in well differentiated oscc (400x). regarding the correlation between both markers and clinicopathological parameters of oral epithelial dysplasia and oral squamous cell carcinoma there was non significant correlation except for the correlation between wwox and clinical presentation of oral epithelial dysplasia which was statistically significant. j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 105 the correlation between fhit and wwox expression in oed cases, the results of the present study revealed statistically a highly significant correlation between the two studied markers (pvalue= 0.000) according to spearman's correlation table 1. in oscc cases, the results revealed statistically a non significant correlation between the two markers (p-value= 0.59). table 2 table 1: correlation between fhit and wwox markers in oed markers wwox fhit r 0.86 p-value 0.000 (hs)* table 2: correlation between fhit and wwox markers in oscc markers wwox fhit r 0.12 p-value 0.59 (ns) differences of fhit and wwox markers between each two groups regarding the correlation of fhit and wwox between each two groups and according to mann-whitney u test, the results of this study revealed statistically highly significant difference between nom and oscc for fhit expression (p-value=0.002), while for wwox expression results showed highly significant difference between nom and oed and between nom with oscc (p-value=0.000). non-significant difference was found between oed and oscc for both markers. table 3 table 3: mann-whitney u test between each two groups markers groups mannwhitney u test p-value fhit nom oed 53.5 0.054 (ns) scc 34.5 0.002 (hs) oed scc 176.5 0.529 (ns) wwox nom oed 13 0.000 (hs) scc 9.5 0.000 (hs) oed scc 184.5 0.683 (ns) discussion clinicopathological findings of oed regarding the epidemiological parameters, including age, gender, site, and clinical presentation, studies showed variable results; in the present study most of oed cases were in patients over 40 years of age, such finding showed that the incidence of dysplastic changes increase with age, and this finding is in agreement with the finding of previous studies (14,15). regarding clinical presentation of oed, white lesion (leukoplakia) represent the most predominant clinical presentation (47.37%), which came in accordance with the findings of (14, 15). clinicopathological findings of oscc: concerning site distribution of oscc, the tongue represented the most predominant site in this study, this is in agreement with the results of (15, 16) and disagree with (17, 18). intraoral squamous cell carcinoma predominates in the ventrolateral tongue, floor of mouth and mandibular alveolus regions. these areas have been postulated to form a ‘gutter zone’ into which soluble carcinogens may pool and exert their neoplastic influence (19). concerning clinical presentation the most predominant presentation recorded in this study was a mass presented in 12 cases (57.14 %), followed by ulcerative lesion 8 cases (38.10%). assessment of fhitimmunohistochemistry as we expected, all cases of nom (100%) showed score iv (diffuse positive staining),this finding was in agreement with previous studies by(20-21) who showed strong positive immunoreactivity for fhit in normal oral epithelium. the fhit gene is expressed at low levels in most tissues of the body but interestingly the highest expression was detected in epithelial cells and tissues. fragile histidine triad gene is inactivated in epithelial tumors and specifically those exposed to environmental carcinogens . this loss of expression seems to occur early in the development of these cancers while, in other cancers, it may be a later event corresponding to progression and aggressiveness (22). concerning oed cases, the results of this study showed that score iv(diffuse positive staining) of fhit was observed in 16 cases (84%), and one case (5%) for each negative (score i),score ii and score iii. regarding correlation between fhit and clinicopathological features, there was statistically non significant correlation of fhit with age, gender, site and clinical presentation. it j bagh college dentistry vol. 26(4), december 2014 immunohistochemical oral diagnosis 106 was indicated that loss of fhit protein not only correlated with tumor aggressiveness but also was detected in pre-cancerous lesions, pointing out the possible importance of the fhit gene in the initiation of cancer (10). in oral squamous cell carcinoma,the results of this study showed that the highest score of fhit was observed in 18/21 cases (85%), negative or low expression was found in 15%, this come in agreement with the data of (20). previous studies showed a range of 4% to 68% absent or markedly reduced fhit expression in oscc (23, 25). this discrepancy may depend on the specificity and sensitivity related to different fhit antibodies, staining protocol, scoring system, and tissue collection (21). assessment of wwox immunohistochemistry in nom, all cases (100%) showed score iii (strong positive staining), agreed with the result of (26) by using rt-pcr. concerning oed cases, the results of this study showed that score iii of wwox was observed in 14 cases (73.68%), reduced expression was found in 5 cases (26.32%). regarding correlation between wwox and clinicopathological features, there was statistically non significant correlation of wwox with age, gender and site, while there was significant correlation with the clinical presentation of oed (white lesion), which was the most clinical presentation in this study. concerning oscc cases the results of this study showed that score iii of wwox was observed in 15 cases from 21with loss of expression in about 30%,this finding come in agreement with (26). many studies have also shown that wwox protein expression is reduced or lost in tumor cells compared with normal cells and that finding could be associated with certain clinical or pathological parameters (27, 28). correlation between fhit and wwox ihc expression in oed and oscc: fragile histidine triad gene exhibits many features similar to wwox. both of them are most active fragile genes and they are large genes with the length of more than 1 mb. both genes are located in common fragile sites and lie in a region of homozygous deletions and present a high frequency of aberrant rt-pcr products in tumors (29). the result of the present study showed a high expression rate of both markers in nom, with parallel reduction of the expression in oed and oscc. it was difficult to find previous studies correlate fhit and wwox immunohistochemical expression in oed and oscc, however we compared our results with other close results. regarding the correlation between fhit and wwox expression in each group, the result revealed a statistically highly significant correlation in oed and non significant correlation in oscc. in accordance with previous reports, lost or reduced fhit and wwox expression has been shown to be an important step in the initiation of tumorigenesis in a variety of tumors, including breast, lung, esophagus, kidney, cervix and other organs (30, 31). studied groups’ comparison between fhit and wwox the result of the present study showed highly significant difference between nom and oscc concerning fhit expression, for wwox expression, results showed highly significant difference between nom and oed and between nom and oscc. in nasopharyngeal carcinoma (npc) study by (32) showed that significant difference was found in fhit and wwox mrna expression levels between (npc) tissues and non cancerous tissues, and fhit mrna expression was strongly correlated with wwox (npc) patient. these results support the concept that both markers are tumor suppressor and reduce in premalignant or malignant lesions. therefore, we speculate that statistically significant difference between fhit and wwox among groups of nom, oed and oscc cases observed in this study suggest their close and synergistic, cooperation and coactivation in the malignant potential of oral lesion and can be use as early diagnostic markers for evaluating these lesions. finally, fhit and wwox could be use as target for gene therapy in patients with malignant oral lesions through its tumor suppressive role. 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et al. inactivation of the wwox gene accelerates forestomach tumor progression in vivo. cancer res 2007; 67: 5606-10. 32. chen xu ,ping li, zheng yang, wu-ning mo, expression of fragile histidine triad (fhit) and ww-domain oxidoreductase gene (wwox) in nasopharyngeal carcinoma. asian pacific j cancer prev 2013; 14(1): 165-71. j bagh college dentistry vol. 29(2), june 2017 marginal discrepancy restorative dentistry 7 marginal discrepancy and fracture resistance of cad/cam ceramill sintron metal copings with different porcelain materials ammar a. al-sa'ady, b.d.s., m.sc., ph.d. (a) mustafa n. abdulghani, b.d.s., m.sc. (b) eanas i. jellil, b.d.s., m.sc. (b) abstract background: this study was performed to compare the marginal fit changes and facture resistance of metal ceramic crowns constructed from ceramill sintron metal coping veneered with three different porcelain veneering materials (vita master koromikos vmk, willi geller creation cc and gc initial mc), also to evaluate the influence of thermocycling on load at fracture. materials and methods: master brass die was scanned ,then metal coping was designed and milled from ceramill sintron blank to get 60 metal copings, then divided randomly into three groups(20 sample), then veneered with porcelain: vita, creation or gc. the marginal gaps were measured before and after porcelain veneering then marginal fit changes was calculated. fracture resistance test was done by instron®, the master die was duplicated to sixty analogs then each analog was fixed into acrylic base. after that each crown was cemented onto the corresponding die analog. ten samples of each group were subjected to compressive loading to fracture and other ten subjected to thermocycling followed by compressive loading to fracture. result and conclusion: the result of marginal fit changes showed that gc group had the lowest marginal gap follow by vita and creation. while vita group showed the highest fracture resistance follows by gc then creation. thermocycling process did not significantly reduce the load at fracture for all groups. key words: ceramill sintron, fracture resistance, marginalgap, metal ceramic crown. (j bagh coll dentistry 2017; 29(2): 12-7 ) introduction in the advent of the all-ceramic crown with its improved aesthetics and cad/ cam technology which may considerably speed up the process of restoration delivery, the porcelain-fused-to-metal restoration still has superior fracture strength due to its rigid metal core (1), and still considered as the gold standard because of their excellent biocompatibility, consistent esthetics, superior strength, and marginal adaptation (2). co-cr for dental purposes was manufactured using three different production technologies: the lost wax technique, cad/cam milling and direct metal laser sintering (3). one major advantage of using milling technology is that some disadvantages of casting, such as casting-induced flaws and porosities which can degrade the quality of the reconstructions, can be avoided as the blanks are manufactured under highly standardized industrial conditions (4). a new chrome-cobalt material (ceramill sintron, amann girrbach) in combination with a new processing strategy now enables this alloy to be milled in the pre-inserted state quickly and cost-effectively using the subtractive technique. (1) professor, department of conservative dentistry, college of dentistry, al-mustansiriyah university. (2) assistant lecturer, department of conservative dentistry, college of dentistry, al-mustansiriyah university. like the most widely established processing strategy for dental zirconia, the blanks also consist of a material in a preliminary state technically (5). ceramill sintron is relatively new introduction to construction metal coping for metal ceramic restoration. to date, no previous studies evaluated the effect of different porcelain veneering materials on marginal gap and fracture resistance of metal ceramic crown construction from ceramill sintron metal coping. the aims of this in vitro study were: 1. to evaluate the influence of using three different veneering materials build up (vita master koromikos, willi geller creation cc and gc initial mc) on marginal fit changes of ceramill sintron metal copings. 2. to compare fracture resistance of different ceramic materials. 3. study the effect of thermocycling on fracture resistance. materials and methods die preparation a brass die model has the shape of central incisor was mounted to metal ring using dental stone to be stable during the preparation, and then the assembly was mounted to the base unit of the surveyor. a dental surveyor was used for the preparation which was done by a high-speed turbine that was attached to the vertical arm of the surveyor with a specially designed cross-like pipe holder to keep j bagh college dentistry vol. 29(2), june 2017 marginal discrepancy restorative dentistry 8 the bur vertical to the finishing line and parallel to the longitudinal axis of the die figure (1). the completed die was 7 mm in length from incisal edge to finishing line, the width was 5mm incisally and 6 mm gingivally and 8 degree of convergence, with chamfer finishing line all around with a depth of 1 mm. fabrication of the copings the prepared brass die was removed from metal ring then mounted in base former using wax to hold the die in position during stone pouring, after the stone set, the stone base with die was removed from the base former and it was ready to be placed in cad-cam scanner. scanable powder was applied to the die to obtain precise scanning picture. ceramill 3d inlab software was used to design the coping with the following information, thickness of wall was 0.5mm, and thickness of cement gap was 25 micrometer, starting from 0 mm at the deep chamfer finishing line, vertical crown margin (metal collar) was 1 mm. mounting the ceramill sintron® co-cr block to the ceramill motion (milling unit) for dry milling, after complete milling of the copings , the copings was removed from ceramill sintron® co-cr block using bur attach to laboratory engine .the green state metal copings had been sintered using ceramill therm (sintering furnace) . sample grouping: each group consisted of twenty metal copings (n=20), then veneered with porcelain: vita for group a, creation for group b and gc for group c. ceram bond® was applied to metal coping using brush, however, ceram bond and all steps of ceramic build up must not cover the metal collar figure (2). the porcelain application using layering technique, according to manufacturer instruction firing chart. figure 1: die preparation. figure 2: ceram bond measurement of the marginal discrepancy difference measurements were made for metal coping before and after porcelain veneering. changes in the marginal fit of the coping after porcelain application were calculated for each coping. during measurement each metal coping and then finished metal ceramic crown had been seated on the master metal die that was fixed to a clear acrylic block with parallel surfaces (6). a reference point was placed on each of four aspects of the base of the die below the margin of the preparation, as a mark. measurements were made at the same point on each aspect. a “spring” loaded holding device (7) was used during measurements figure (3). specimens were examined under a measuring light traveling microscope calibrated to 0.001 mm (1 µm) at magnification x 100. the marginal adaptation of each metal coping and finished metal ceramic crown were determined by measuring the vertical marginal discrepancy between the margin of the preparation and the gingival margin of the coping or crown (7,8). figure 3: “spring” loaded holding device j bagh college dentistry vol. 29(2), june 2017 marginal discrepancy restorative dentistry 9 fracture resistance test i. master die was duplicated to sixty metal analogs : the master die was removed from the previous block and fixed to another large clear acrylic block. the die was duplicated using mold of the prepared master die that was made with polyvinylsiloxane putty impression material. the mold was used to make 60 wax patterns; later these wax patterns invested and caste, to get 60 die analogs. ii. die analogs mounting in acrylic base: a base former coated with aluminum foil and place into table of surveyor, the die analog was fixed into a piece of sheet wax inside the base former , then adjustment for die analog position was done to ensure that its long axis was perpendicular to horizontal plane figure (4) .cold cure acrylic was mixed then poured immediately to base former. after complete setting of cold cure acrylic, the base was taken off from base former, this procedure was repeated to get 60 die analogs in acrylic base. iii. cementation of crown to die analog zinc phosphate cement was used for crown cementation, and it was mixed, then applied to the internal surface of the crowns. finger pressure was applied to initially seat each crown on its respective die analog then remain under static pressure of 2.5 kg for 10 minutes using custom made device. iv. measurement of load at fracture: each group was randomly divided into two subgroups (10 crowns). the crowns of one subgroup was loaded in the instron machine at an angle of 45 degrees to the long axis of the die analog-crown assembly using custom made table figure (5). this angle of loading was chosen to simulate a contact angle between maxillary and mandibular anterior teeth found in angle’s class i occlusal relationship (9). a stainless steel rod with a 2-mm wide flat end, mounted on a universal testing machine (instron), was used to apply controlled loads to the crown, at a crosshead speed of 2.5 mm/min, until fracture. the compressive load was applied palatally, 3 mm lower than the incisal edges of the specimens (10) fig (6). the load at fracture was recorded. the crown of the other subgroup of the samples was subjected to thermocycling. the samples were submitted to 500 thermo-cycles in distilled water between 5°c and 55°c. the exposure to each bath was 30s and the transfer time was 10 second (11). after thermocycling (aging), all samples were subjected to load until fracture using the same procedure that used for crowns that did not subjected to thermocycling. the maximum force to produce fracture was recorded in newtons. figure 4: die analogs mounting figure 5: angle of load application figure 6: load application in acrylic base results for marginal fit changes parameter the result of this study showed that the gc group have the lowest mean of marginal gap changes which was 5.5µm, while 6.1 µm for both vita and creation group (table-1). anova test showed that there is significant differences among group (table-2), while lsd test showed that there was a no significant difference between the vita group and the creation group (p > 0.05), also there was highly significant difference for both comparison (creation group vs. the gc group) and (gc group vs. vita) group at p < 0.01 (table-3). the result related to the effect of ceramic veneering material on the fracture resistance showed that the vita group was have the highest mean of load at fracture which was 1127 n, followed by the mean of gc group which 825.3 n , and the lowest mean was 529.7 n for the creation group (table-4). j bagh college dentistry vol. 29(2), june 2017 marginal discrepancy restorative dentistry 10 table 1: descriptive statistics of marginal fit changes* (µm) of all groups * marginal fit changes = marginal gap after porcelain veneering – marginal gap before table 2: anova test for mean marginal gaps among the groups s.v.o. s.s. df ms f p-value sig. between groups 4.693 2 2.347 5.161 .009 hs within groups 25.916 57 .455 total 30.609 59 table 3: lsd test for mean marginal gap changes between groups table 4: descriptive statistics of mean load at fracture (n) of all group: without aging and with thermal aging anova test showed that there was high significant differences at p < 0.01(table-5), while lsd test showed that there was a highly significant difference among all groups (vita, creation and gc group) p< 0.01 (table-6). result related to effect of thermocycling (aging) on the load at fracture of each group showed that the mean of load at fracture for vita subgroups were1127 n for without aging subgroup and 1121.3n for aging subgroup. also creation subgroups mean were 529.7 n, 525.2 n for with aging and without aging respectively, while the mean of without aging subgroup of gc was 825.3 n and 821n for with aging subgroup (table-4). however student's t-test show that aging (thermocycling) not significantly deteriorate the fracture resistance of subgroups independent on the type of porcelain veneering at p >0.05 (table-7). table 5: anova test for mean of load at fracture among the groups s.s. df m.s. f p-value sig between groups 1783898.467 2 891949.233 68.302 .000 hs within groups 352592.200 27 13058.970 total 2136490.667 29 table 6: lsd test for the mean of load at fracture between groups table 7: comparison of load at fracture (n) between subgroup (no aging) and (with aging) of each group using student's t-test. comparison between subgroups p-value sig. vita without – with aging .931 ns creation without – with aging .799 ns gc without – with aging .939 ns group n mean s.d min. max. vita 20 6.1 0.731 5.0 7.3 creation 20 6.1 0.599 5.0 7.0 gc 20 5.5 0.685 4.2 6.8 groups p-value sig. vita creation .870 ns creation gc .006 hs gc vita .009 hs subgroup n mean sd min. max. vita without aging 10 1127 146.57 870 1350 with aging 10 1121.3 144.67 865 1330 creation without aging 10 529.7 39.77 490 592 with aging 10 525.2 38.1 489 600 gc without aging 10 825.3 126.93 580 1088 with aging 10 821 122.68 610 1100 groups p-value sig. vita creation .000 hs creation gc .000 hs gc vita .000 hs j bagh college dentistry vol. 29(2), june 2017 marginal discrepancy restorative dentistry 11 discussion marginal gap value was measured for each metal coping before and after porcelain veneering in order to obtain marginal fit changes value (12) to ensure that effect of metal coping manufacturing variable on marginal gap was excluded. the lowest mean of marginal fit changes values of coping was 5.5 µm for gc group , while the mean of changes of the other groups (vita , creation ) was 6.1 µm. statistical analysis showed a highly statistical significant difference in marginal fit changes when compare gc by vita and gc by creation, while there was no significant difference between vita and creation group. there were no previous similar studies to compare with. however, veneering process and its associated heat-treatment are known to affect the marginal fit of metal or ceramic core materials (13-15). in present study, three different porcelain veneering materials were used with three different firing protocols. this may account for the difference in the mean of marginal fit changes between groups. another explanation was the thermal incompatibility between metal and veneering porcelain. however, this facts cannot interpret the result of this study because all types of porcelain veneering used had approximately the same cte (25–500°c), in addition ceram bond that was used in present study which acts as an efficient cte buffer between porcelain and metal alloy (16). another factor that may cause marginal discrepancy was external grinding and internal abrasive blasting of crowns (17). statistical analysis related to the result of fracture resistance showed that there was a highly significant difference among all groups (vita, creation and gc group) p< 0.01. the factors that lead to the fracture of metal-ceramic restorationscan classified into: technical factors, dentist-related factors, inherent material properties, direction, magnitude and frequency of applied loads, environmental factors. technical factors include:surface treatment and design of the metal coping, compatibility between the coefficient of thermal expansion of the metal and porcelain, ceramic build-up and firing technique, thickness of porcelain, thickness and elastic modulus of the metal substructure and location of porcelain-metal finish lines (18). in the present study, technical factors and applied load variables cannot explain the result of this study since all of these variables were excluded by standardization technique except the firing technique which differed among the groups which may affect the fracture resistance. also dentist-related factors and environmental factors were excluded since the study was in vitro not in vivo. inherent material strength and different microstructure of porcelain can explain the result of present study since different types of porcelain veneering materials were used (19-21) which had different grain sizes. the statistical analysis result show that thermocycling (aging process) show no significant difference in fracture resistance in all group, this may be due to fewer thermocycling number.this agreed with fiket et al. (22) and makramani et al., (11) while disagreed with aboumadina and abdelaziz (23). within the limitation of this study, the following conclusions could be drawn: 1. gc group had significantly lower marginal fit changes among the tested groups. 2. there was no significant difference between vita and creation groups in marginal fit changes. 3. fracture resistance was highest for vita follow by that of gc then creation. 4. thermocycling did not significantly reduce the amount of force up to fracture of all groups. references 1. schweitzer dm, goldstein gr, ricci jl, silva nr, hittelman el. comparison of bond strength of a pressed ceramic fused to metal versus feldspathic porcelain fused to metal. j prosthodont 2005; 14: 23947. 2. walton tr. an up to 15-year longitudinal study of 515 metal-ceramic fpds: part 1. outcome. int j prosthodont 2002; 15: 439-45. 3. ortorp a, jonsson d, mouhsen a, vult von steyern p. the fit of cobalt-chromium three-unit fixed dental prostheses fabricated with four different techniques: a comparative in-vitro study. dent mater 2010; 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8(3): 239-46. 21. carty wm, pinto bm. effect of filler size on the strength of porcelain bodies. materials & equipment/whitewares: ceramic engineering and science proceedings 2008; 23(2). 22. fiket d, ćatović a, franz m, and seifert d. comparative investigation of the fracture strengths of crowns of three different non-metal materials. acta stomatol croat 2005; 39(3): 301-5. 23. abou-madina mm, abdelaziz km. influence of different cementation materials and thermocycling on the fracture resistance of ips e.max press posterior crowns. the internet j dent sci 2009; 6(2): 1-15. المستخلص ویضات األصطناعیة دقة الحواف و القوة ، ألي ترمیم معوض لألسنان ھي صفة مھمة . ویمكن أعتبارعدم تطابق للحواف أو قلة القوة سبب مھم یؤدي الى فشل التع المعدنیة مكسو ceramill sintronتم أجراء ھذا البحث لغرض تقییم أختالف ظبط حافات و مقاومة الكسر لتیجان السیرامیك المصنعة من أغلفة ال لذلك لألسنان. .، أضافة الى تقییم تأثیر التدویر الحراري على قیمة الحمل المطلوب للكسر gc , creation , vita)بثالث مواد خزفیة مختلفة والتي ھي ( مصنوع من مادة البراص و یمثل القاطع العلوي األمامي المحضر لتصنیع ستین غالف معدني بطریقة الخراطة (die)طریقة العمل فقد تضمنت أستعمال نموذج ئھا بقشرة خزفیة نوع .ثم تم تقسیمھا عشوائیا الى ثالث مجموعات ، كل مجموعة تتكون من عشرین غالفا وقد تم أكسا ceramill sintonبأستخدام قالب ال vita للمجموعة ( أ ) ، خزف نوعcreation للمجموعة (ب) و خزف نوعgc للمجموعة (ج).و قد تم قیاس دقة الحواف قبل و بعد أضافة القشرة الخزفیة والطریقة instronلكل مجموعة بأستخدام المجھر الضوئي المتنقل،لغرض حساب مقدار التغیر في دقة الحواف.بعد ذلك تم أختبار مقاومة الكسر بواسطة جھاز ال ). بعد ذلك كل تاج سیرامیك یثبت الى نظیرھا (acrylicتین نظیر ، ومن ثم كل نظیر یثبت بقاعدة من ال) الى سdieكانت كاألتي : مضاعفة النموذج المحضر( راري ومن ثم بأستخدام الزنك فوسفیت سمنت.وقد تعرض عشرة من كل مجموعة الى ضغط مستمر لغایة الكسر و العشرة األخرین تعرضوا الى عملیة التدویر الح ة الكسر.تعرضوا الى ضغط مستمر لغای كانت تختلف أختالف واضح عن المجموعتین األخرتین في قیمة تغیردقة الحواف ، في حین ال یجود gcأظھرت النتائج أن مجموعة التیجان المكسوة بخزف نوع مة الكسر، في حین أن عملیة التدویر . بینما كان ھناك أختالفا جلیا بین المجموعات بمقدار مقاوcreationو vitaأختالف واضح ما بین المجموعة المكسوة ب الحراري لم تقلل قمیة الحمل عند الكسر الى حد كبیر. قد أظھرت أقل تغیرا في دقة الحواف.في حین كانت مقاومة الكسر ھي األعلى gcو یمكن أن نستنج من ھذه الدرسة : أن مجموعة التیجان المكسوة بخزف نوع أضافة الى ذلك عملیة التدویر الحراري تقلل الحمل عند الكسر و لكن لیس الى حد كبیر . gc.ثم المجموعة creationیلیھ مجموعة vita للمجموعة lubaba.doc j bagh college dentistry vol. 27(2), june 2015 effects of light oral and maxillofacial surgery and periodontics 110 effects of light smoking on salivary levels of alkaline phosphatase and osteocalcin in chronic periodontitis patients lubaba a. abdul ameer, b.d.s. (1) basima gh. ali, b.d.s., m.sc. (2) abstract background: chronic periodontitis is an inflammatory disease that affects the supporting tissues of the teeth and it’s common among adults. smoking is an important risk factor for periodontitis induces alveolar bone loss. alkaline phosphatase enzyme is involved in the destruction of the human periodontium. it is produced by many cells such as polymorphonuclear leukocytes, osteoblasts, macrophages and fibroblasts within the area of the periodontium and gingival crevice. osteocalcin is one of the most abundant matrix proteins found in bones and the only matrix protein synthesized exclusively there. smaller osteocalcin fragments are found in areas of bone remodeling and are actually degradation products of the bone matrix.the purpose of this study was to evaluatethe effect of smoking on the salivary alkaline phosphatase and osteocalcin in subjects with chronic periodontitis compared to control subjects. materials and methods: five ml of unstimulated whole saliva samples and full-mouth clinical periodontal recordings (plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level) were obtained from study groups (25 light smokers and 33 non-smokerssubjects, both with chronic periodontitis) and control groups (8 light smokers and 13 non-smokers subjects, both with healthy periodontium). all subjects were systemically healthy males, with age range (30-50) years. salivary alkaline phosphatase and osteocalcin levels were determined by colorimetric and enzyme-linked immunosorbent assays, respectively. results: smoker chronic periodontitis patients revealed non-significant differences in clinical periodontal parameters with non-smoker counterparts (p o.o5) in terms of plaque index, probing pocket depth and clinical attachment loss, with slight increase in plaque index value in smoker chronic periodontitis group(1.42±0.46) than non-smoker chronic periodontitis group, while there were highly significant differences in terms of gingival index and bleeding on probing(p ≤ 0.01).osteocalcin levels were lower in smoker chronic periodontitis group (0.13±0.20) than non-smoker chronic periodontitis group (1.09±2.26) with significant difference (0.05 ≥ p > 0.01). mean of alkaline phosphatase level was lower in smoker chronic periodontitis (11.14±4.53) than non-smoker chronic periodontitis (11.45±4.17) with a non-significant difference, while there was a significant difference inalkaline phosphatase concentrations between smoker and non-smoker control groups.there were non-significant differences between smoker chronic periodontitis and smoker control groups in terms of osteocalcin and alkaline phosphatase concentrations. there were nonsignificant differences between non-smoker chronic periodontitis and non-smoker control groups in terms of osteocalcin and alkaline phosphatase concentrations. conclusion: within the limits of this study, it may be suggested that suppression of salivary osteocalcin levels by smoking and slight increase in alkaline phosphatase in smokers groups, may explain the deleterious effects of smoking on periodontal health status. key words: chronic periodontitis, smoking, osteocalcin and alkaline phosphatase. (j bagh coll dentistry 2015; 27(2):110-114). introduction the chronic periodontitis (cp) has been defined as “an infectious disease resulting in inflammation within the supporting tissues of the teeth, progressive attachment loss, and bone loss” (1). although the microbial components of the subgingival plaque biofilm are the aetiological factors, the pathogenesis of periodontitis is a complex interaction between the microbiota and host tissues modified by environmental factors in particular smoking, age, systemic disease, and genetic susceptibility (2). alkaline phosphatase (alp) is intracellular enzyme produced by many cells such as polymorphonuclear leukocytes (pmnls), osteoblasts, macrophages, and fibroblasts within the area of the periodontium and gingival crevice (3). (1)master student, department of periodontics, college of dentistry, university of baghdad. (2)assistant professor, department of periodontics, college of dentistry, university of baghdad. when a periodontal tissue becomes diseased or its cells become damaged due to edema or destruction of a cellular membrane, i.e. of a cell as a whole, this intracellular enzyme is increasingly released into the gcf and saliva where its activity can be measured (4). osteocalcin (oc) is the most abundant noncollagenous protein in bone, comprising almost 2% of total protein in the human body. it is important in bone metabolism and is used as a clinical marker for bone turnover(5).it is a product of differentiated osteoblasts(6). its main physiological functions are calcium ion homeostasis, maintain the normal bone mineralization rate, inhibit the abnormal formation of hydroxy appetites crystal, and to be involved in bone remodeling through a negative feedback mechanism(7). khiste et al (8) found that oc levels in oral fluids increased during an increased pd activity. j bagh college dentistry vol. 27(2), june 2015 effects of light oral and maxillofacial surgery and periodontics 111 on the other hand, özçaka öet al (9) found that the smoker periodontitis patients revealed lower salivary oc levels than non-smoker counterparts. thus the aim of the present study was to evaluate the level of osteocalcin and alkaline phosphatase in saliva of patients with chronic periodontitis smokers compared to non-smokers. light smoking was chosen in this study. there is no consensus on how to best define “light smoking”. light smokers have been classified as smoking <1 pack per day, <15 cigarettes per day, <10 cigarettes per day, and 1 to 39 cigarettes per week (10). subjects and methods subjects sample population consisted of seventy nine individuals; systemically healthy maleswith an age ranged between 30 to 50 years were involved in this study. they were from attendants seeking periodontal treatment in the department of periodontics at teaching hospital of baghdad college of dentistry. the sample population was divided into two main groups study and control. the study groups consistedof fifty eight subjects with chronic periodontitis, twenty five of them were light smokers (g1), thirty three were nonsmoker (g2), based on clinical examination. chronic periodontitis was defined according to the periodontal disease classification systemof the american academy of periodontology (11). the control groups consisted of twenty one subjects with healthy periodontium, eight of them were light smokers subjects (g3), thirteen were nonsmokers (g4), based on clinical examination. clinically healthy gingiva was defined by gingival index scores (gi)(12). this group represent as a base line data for the level of salivary oc and alp. method saliva collection the samples were collected between 10 a.m. and 1 p.m., at least 1 hour after the last meal. each subject was asked to rinse his mouth thoroughly with water to insure the removal of any debris, then waiting for 1-2 min for water clearance. five ml of unstimulated whole saliva (resting) was collected from each subject before clinical examination.then the collected saliva was divided into 2 parts: first part was subjected to cold centrifuge at 4000 rpm for 30 minutes in the teaching laboratories of baghdad medical city, and then the clear supernatant saliva was collected by micropipette into eppendrof tubes and store at 80˚c (deep freeze) until biochemical analysis of oc, which was done by enzyme linked immunosorbent assay (elisa) technique by using kit manufactured by (cusabio, china). the second part was subjected to centrifuge at 3000 rpm for 10 minutes in the poisoning center in ghazy alharery hospital, and then the clear supernatant saliva was collected by micropipette into eppendrof tubes and store at -20 ˚c until biochemical analysis of alp, which was done by colorimetric method by using kit manufactured by (biomare, france).samples containing blood were discarded. all samples were allowed to stand at room temperature before their analysis. clinical assessment then clinical examination was done for each subject on a dental chair; by using michigan o periodontal probe, all periodontal variables were recorded on four surfaces for all teeth except third molars. the clinical periodontal parameters for study groups include: (pli, gi, bop, ppd and cal), for control groups: (pli & gi). the assessment of dental plaque was made according to the plaque index (pli) by sillness and loe (13). the gingival condition was assessed by using the criteria of gingival index (gi) by loe (12). assessment of bop was made by inserted periodontal probe to the bottom of the gingival pocket and is moved gently along the tooth (root) surface. if bleeding occurs within 30 seconds after probing, the site was given a positive score or (1), and a negative score or (0) for the non-bleeding site (14). probing pocket depth (ppd) defined as the distance between the base of the pocket and the gingival margin. cal the distance from the cej to the location of the inserted probe tip (bottom of gingival crevice or periodontal pocket). (1) statistical analysis the study variables were statistically analyzed usingstatistical process for social science (spss version 19) by using mean, median, standard deviation (sd), percentage, mannwhitney u test. results table (1) shows the mean ± sd (standard deviation) for the clinical parameters, while table (2) shows the mean ± sd (standard deviation) for the biochemical parameters which have been measured in this study. table (3) demonstratesstatistically significance differences among the groups. the mean of plaque index was slightly higher in g1 (1.42±0.46) than g2 (1.38±0.50), while j bagh college dentistry vol. 27(2), june 2015 effects of light oral and maxillofacial surgery and periodontics 112 there were decreases in means of gi, bop, ppd and cal in g1 than g2. mean of oc was lower in g1 (0.13±0.20) than g2 (1.09±2.26), and lower in g3 (0.09±0.05) than g4 (0.11±0.05).mean of alp was lower in g1 (11.14±4.53) than g2 (11.45±4.17), while mean of alp was higher in g3 (10.31±2.51) than g4 (8.70±2.75). there were no significant differences between g1 and g2 in terms of pli, ppd and cal, but there was a highly significant difference in gi and bop (p ≤ 0.01).there was a significant difference in the concentration of salivary oc between g1 and g2 (0.05 ≥ p > 0.01), while smoking had a non-significant effect on oc concentration compared tonon-smokers in control group. there was a non-significant difference in alp concentrations between g1 and g2 (p 0.05). there was a significant difference in alp concentrations between g3 and g4 (0.05 ≥ p > 0.01).there was a non-significant difference between g1 and g3 in terms of oc and alp concentration.there was a non-significant difference between g2 and g4 in terms of oc and alp concentration. table 1: descriptive statistics (mean±sd) of the clinical parameters in all groups variables g1 g2 g3 g4 pli 1.42±0.46 1.38±0.50 0.54±0.25 0.64±0.17 gi 0.92±0.33 1.12±0.14 0.31±0.13 0.51±0.06 bop% 3.92±5.65 10.88±11.02 ppd 3.90±1.78 4.27±1.98 cal 3.22±0.93 3.74±0.85 table 2: descriptive statistics (mean±sd) of the biochemical parameters in all groups variables g1 g2 g3 g4 oc (ng/ml) 0.13±0.20 1.09±2.26 0.09±0.05 0.11±0.05 alp (iu/l) 11.14±4.53 11.45±4.17 10.31±2.51 8.70±2.75 table 3: inter group comparison for the clinical & biochemical parameters with significant difference variables g1-g2 g1-g3 g2-g4 g3-g4 pli 0.556 0.238 gi 0.000** 0.000** bop% 0.000** ppd 0.151 cal 0.064 oc 0.019* 0.704 0.359 0.210 alp 0.700 0.737 0.051 0.050* *significant difference 0.05 ≥ p > 0.01, **highly significant difference p ≤ 0.01 discussion in the present study, it appear that smoking have a non-significant effect on the level of pli, ppd and cal, although pli seems to be slightly higher in smoker chronic periodontitis than nonsmoker counterpart, this finding is in agreement with the other previous studies haffajee and socransky (15); maddipati et al (16). this increased level of plaque which has been observed in smokers' chronic periodontitis subjects have been tentatively attributed to personality traits as the educational level, leading to decreased oral hygiene habits in smokers. also could be due to heat and accumulated product of combustion that result in tobacco stain as well as calculus are particular undesirable local irritants that increased with smoking (17). one study concluded that poorer cleanliness found in smokers both before and after tooth brushing may be explained, in part at least, by their shorter tooth brushing time (18). results of the gi and bop in the present study showed highly significant differences between smoker and non-smoker chronic periodontitis. these results are in the agreement with the other previous study ali and ali (19). this may be due to tobacco smoke products interfering with the vascular inflammatory response. it is generally accepted that smoking causes vasoconstriction of peripheral vessels. it is therefore conceivable that such a constrictive action on gingival vessels would result in the suppression of vascular properties of inflammation such as bleeding, redness, and j bagh college dentistry vol. 27(2), june 2015 effects of light oral and maxillofacial surgery and periodontics 113 exudation. it is possible that substances in tobacco smoke can reduce the capacity of microorganisms in plaque to produce irritants (20). maddipati et al (16), showed decrease in blood vessels density in smokers cp group. regarding the ppd and cal, the present study clarified that the values of these parameters were slightly lower in smoker chronic periodontitisthan in non-smoker counterpartand results illustrated non-significant differences between them. number of previous studies agreed with the present results haniokaet al (21); zcaka et al (9). the present study results disagreed with haffajee and socransky (15) whom found there was general increase in ppd and cal in smoker than non-smoker chronic periodontitis groups.the possible cause of this result is reduced in sample size. in the present study, the saliva oc concentrations were higher in the chronic periodontitis groups than in control groups; this result is in agreement with zcaka et al (9) this increase may indicate an increase in the cellular activities of osteoblasts to repair the damaged alveolar bone. moreover, the present study indicated significantly lower salivary oc concentrations in the smoker chronic periodontitis than non-smoker counterpart; this result is in agreement with önder et al (22); zcaka et al (9). a non-significant difference of oc concentrations between control smoker and nonsmoker counterpart with slight decrease in oc concentration in control smoker than non-smoker counterpart, this result is disagree with zcaka et al (9) who found a significantly lower oc concentrations in smoker than the non-smoker control groups. this difference in the results belongs to the differences in the number of subjects between two studies and differences in the statistical methods that were applied.these results suggest that smoking may induce osteoblast depression, either directly or via hormonal changes. in this study the comparison between smoker chronic periodontitis and smoker control group, revealed a non-significant difference in oc concentration, also there was a non-significant differences between non-smoker chronic periodontitis and non-smoker control group with slight increase in the concentration of oc in nonsmoker chronic periodontitis which disagree with zcaka et al (9), who found a significant differences in their results.the differences in patient numbers and ⁄ or the possible differences in the disease activity states may explain the differences in findings of the present study and the previous ones. the findings of this study revealed a nonsignificant difference in the salivary alp concentrations between smoker and non-smoker chronic periodontitis groups with slightly increase in the concentration of alp in non-smoker than smoker chronic periodontitis groups; this result was in disagreement with ban &leka'a(23),who found that the level of alp in the smoker group was significantly higher than the non-smoker group.the general explanation is the different sample size between the two groups. in this study, there was a significant difference in alp concentration between smokerand nonsmoker control groups.the presence of alp in the saliva is usually indicating the pathological changes occurring in the underlying periodontal tissues. in this study, there were non-significant differences between smoker chronic periodontitis and smoker control groups, and between nonsmoker chronic periodontitis and non-smoker control groups in terms of alp concentration, with slight increase in the alp concentration in cp groups compared to control groups, the increased activity of alp indicates that the pathological destructive process has affected the alveolar bone, which means that the periodontal disease has significantly advanced. furthermore, among the various periodontopathogenic bacteria p.intermediaand p. gingivalisare known to have high alp activity (24) and in this study the smoker group was shown to have higher pli which mean higher number of bacteria and this also adding to the total alp level. references 1. newman mg, takei h, klokkevold pr, carranza fa. carranza’s clinical periodontology. 11th ed. philadelphia: saunders; 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71: 1846-52. 22. gürlek o, lappin df, buduneli n. effects of smoking on salivary c-telopeptide pyridinoline crosslinks of type i collagen and osteocalcin levels. arch oral biol 2009; 54(12): 1099–104. 23. karem b, ibrahim lm. periodontal health status and salivary enzymes level in smokers and non-smokers (comparative, cross sectional study). j bagh coll dentistry 2013; 25(3): 91-96. 24. sanikopsh, bhattacharjee s, patil s. a comparative analysis of serum alkaline phosphatase in smokers and non-smokers with chronic periodontitis. srm uni j dent sci 2011; 2(4): 290-5. الخالصة المزمن اللثة التدخین ھو عامل خطر ومھم لتقدم وتطور ألتھاب . المزمن ھو مرض التھابي یصیب األنسجة الداعمة لألسنان وھي حالة أكثر شیوعا لدى البالغینألتھاب اللثة الخلفیة ویتم إنتاجھ من قبل العدید من الخالیا مثل الكریات البیض . تھاب األنسجة المحیطة باألسنانینفرز إنزیم الفوسفاتیز القلوي في حالة أل. ویعمل على تحفیز فقدان العظم المحیط باألسنان األوستیوكالسین ھو واحد من بروتینات المصفوفة العظمیة األكثر وفرة في . متعددة النوى، الخالیا البانیة للعظم، والخالیا اللیفیة الضامة في منطقة األربطة الداعمة للسن وشق اللثة الھدف من . متم العثور على قطع صغیرة من تكسر األوستیوكالسین في مناطق إعادة تشكیل العظام و ھي في الواقع نواتج التحلل من مصفوفة العظا. لعظام ویصنع حصرا ھناكا مختلفة من أنزیم الفوسفاتیز القلوي اللعابي واألوستیوكالسین ومقارنة النتائج كیز راالمزمن یظھرون ت ألتھاب اللثةذوي تدخینا خفیفا من الدراسة للتحقیق في ما إذا كان المرضى المدخنین .مع مجموعة السیطرة مؤشر الصفیحة الجرثومیة، مؤشر : (الحصول على خمسة مل من عینات اللعاب غیر المحفز، وأجراء قیاسات المؤشرات ماحول األسنان السریریة وتتضمن المواد وطرائق العمل من غیر 33 ,تدخینا خفیفا من المدخنین 25( من مجموعتي الدراسة ) ة، مؤشر النزف عند التسبیر، مؤشر عمق الجیوب باألضافة الى فقدان األنسجة الرابطة سریریاألتھاب اللث وجمیع المشتركین ). صحیة ن یملكون أنسجة ماحول األسنانمن غیر المدخنین اللذی 13و تدخینا خفیفا من المدخنین 8(ومجموعتي السیطرة ) المزمن ألتھاب اللثةالمدخنین ذوي مرض تم تحدید أنزیم الفوسفاتیزالقلوي بواسطة مقیاس الطیف الضوئي ومستویات األوستیوكالسین . سنة) 5030(في الدراسة كانوا من الذكور،أصحاء سریریا، و الفئة العمریة تتراوح مابین . اللعابیة بأستخدام تقنیة مقایسة األنزیم المرتبط الممتز المناعي مؤشر الصفیحة الجرثومیة ، مؤشر عمق الجیوب (المزمن لدیھم نتائج مماثلة لمؤشرات ماحول األسنان السریریة ألتھاب اللثةذوي تدخینا خفیفا من أظھرت النتائج أن المدخنین تائجالن ألتھاب اللثةمن ذوي تدخینا خفیفاة مؤشر الصفیحة الجرثومیة لدى المدخنین مع ارتفاع طفیف في قیم, مع نظرائھم من غیر المدخنین) باألضافة الى فقدان األنسجة الرابطة سریریا من تدخینا خفیفا وكانت المستویات الدنیا لألوستیوكالسین لدى المدخنین. بینما كانت ھناك فروقات معنویة كبیرة للغایة من حیث مؤشر ألتھاب اللثة ومؤشر النزف عند التسبیر, المزمن كان ھناك فرق غیر ملحوظ في تركیزه بین , بالنسبة لتركیز أنزیم الفوسفاتیز القلوي.المزمن مقارنة مع نظیرھم من غیر المدخنین مع وجود فروقات معنویة ألتھاب اللثة مرضى مجموعة من وغیر المدخنین تدخینا خفیفاي بین المدخنین المزمن، في حین كان ھناك اختالف كبیر في تركیز الفوسفاتیز القلو ألتھاب اللثةوغیر المدخنین لمرضى تدخینا خفیفاالمدخنین من مجموعة السیطرة من حیثتراكیز تدخینا خفیفا المزمن والمدخنین ألتھاب اللثةمن مرضى تدخینا خفیفا أظھرت النتائج عدم وجود فروقات معنویة كبیرة بین المدخنین. السیطرة المزمن و غیر المدخنین من مجموعة السیطرة من حیث ألتھاب اللثةكذلك عدم وجود فروقات معنویة كبیرة بین غیرالمدخنین من مرضى و. األوستیوكالسین و أنزیم الفوسفاتیز القلوي .تراكیز األوستیوكالسین و أنزیم الفوسفاتیز القلوي نتیجة التدخین قد یفسر اآلثار الضارة للتدخین على یادة الضعیفة ألنزیم الفوسفاتیز القلوي والز في حدود ھذه الدراسة، فإنھ یمكن أستنتاج أن قلة مستوى األوستیوكالسین اللعابي ستنتاجاأل .وضع األنسجة المحیطة باألسنان haitham f.doc j bagh college dentistry vol. 25(3), september 2013 comparison of regional restorative dentistry 19 comparison of regional bond strength of post space of fiber-reinforced post luted with two types of cements at different testing times haitham j. al-azzawi, b.d.s., m.sc. (1) m.n.h., b.d.s, m.sc. (2) abstract back ground: this in vitro study was carried out to investigate the effect of post space regions (coronal, middle and apical), time and the mode of polymerization (dual, self-cured) of the cements used on the bond strength between translucent fiber post and root dentin by using push-out test. materials and methods: forty eight extracted mandibular first premolars (single root) were instrumented with protaper universal system files (for hand use) and obturated with gutta percha for protaper and ah26® root canal sealer following the manufacturer instructions, after 24 hours post space was prepared using frc postec® plus drills no.3 creating 8 mm depth post space. the prepared samples were randomly divided into two main groups (24 samples each) according to the used cement (group m, self-cure, multilink n) and (group r, dual cure, relyx u100). then each group was subdivided into three groups (each group contains 8 samples) according to the testing time after cementation. (g m1: push out test after 24 hour of cementation with multilink n), (g m2: push out test after one week of cementation with multilink n),(g m3: push out test after two weeks of cementation with multilink n), (g r1: push out test after 24 hours of cementation with relyxu100), (g r2: push-out test after one week of cementation with relyxu100), (g r3: push out test after two weeks of cementation with relyxu100). after cementation and incubation each root was sectioned horizontally into 3 slices (2 mm in thickness) represent the coronal, middle and apical regions of the post space. push out bond strength test was performed and measured using a universal testing machine (tinius-olsen) at across head speed of 0.5 mm/min. results: showed that regarding the root region, the bond strength values increased significantly apical to coronal region in both tested cements. for the effect of time, the bond strength values also significantly increased with time for both tested cements. for mode of polymerization, the self-cured resin cement multilink n showed higher bond strength values. conclusion: the retention of fiber post was affected by root region, mode of polymerization of the cements used and time elapsed after cementation of the post. key words: fiber post, multilink resin cement, relyxu100, push-out test, root region. (j bagh coll dentistry 2013; 25(3):19-23). introduction in 1990 duret et al (1) described a non-metallic material for the fabrication of posts based on the carbon-fiber reinforcement principle. laboratorybased studies have shown that these posts have a high tensile strength and modulus of elasticity, similar to dentine. previously, rigid metal posts resisted lateral forces without distortion and this resulted in stress transfer to the less rigid dentine causing potential root cracking and fracture. recently, fiber-reinforced composite (frc) post-and core systems have come to be widely used in the restoration of endodontically treated teeth. frc posts offer a number of advantages over metal posts due to their modulus of elasticity being closer to that of dentin and superior esthetic quality (2). adhesive composite cement, whose elastic modulus in the same range of that of both of the post and dentin, are routinely used to adhesively lute the post into the root (3). recently developed self-adhesive resin cements do not require pretreatment of the dentin. (1)professor, department of conservative dentistry, college of dentistry, university of baghdad. (2) m.sc student, department of conservative dentistry, college of dentistry, university of baghdad. because these cements do not use an adhesive system, they drastically reduce the number of application steps, shortening clinical treatment time and decreasing technique sensitivity since it minimizes procedural errors throughout the treatment phases (4). bond strength can be determined by several techniques, but the push out bond strength test is believed to provide a better estimation of the actual bonding effectiveness than conventional shear bond strength test (5). materials and methods sample selection forty eight extracted single rooted teeth (mandibular premolars), collected from different health centers were used in this study. the age, gender, pulpal status and reason for extraction were not considered, and the criteria for teeth selection including the followings: single straight root, no visible root caries, no fractures, cracks or external resorption on examination with x10 magnifying eye lens and light cure device, diagnostic x-ray was taken to confirm the existence of a single straight canal, fully formed apex and no signs of internal resorption, j bagh college dentistry vol. 25(3), september 2013 comparison of regional restorative dentistry 20 calcification or previous endodontic therapy, patent apical foramen. samples preparation length of the root was determined by a digital vernier and marker. the tooth hold with moist gauze to avoid dehydration and the crown of the tooth was sectioned with a diamond discs mounted on straight hand piece, under water coolant. the length of the root was adjusted to 14 mm from a flat reference point to the root apex. the mold was obtained by using a plastic test tube (2.5ml). the condensation silicon impression material base and catalyst were mixed according to manufacturer’s instructions; the putty was folded and kneaded gently for about 30 sec. until the color was even, without any stripes. the putty material was placed inside the plastic tubes and the coronal end was adjusted with the coronal end of the tube. after that the teeth were placed in the center of the putty material with the aid of dental surveyor to position the long axis of the roots parallel to that of the plastic tubes (6). endodontic treatment root canal instrumentation was performed using protaper hand files (dentsply, switzerland) in crown down technique. irrigation performed using of 2.5% naocl after every change of file size throughout the cleaning and shaping of the root canals, dried with paper points and filled with gutta-percha for protaper f4 (dentsply, switzerland) and ah26 root canal sealar (dentsply, germany). the excess gutta-percha at the canal orifice was removed. the access opening were sealed with temporary filling material, and stored at 37ºc, 100 % humidity in an incubator (memmert, germany) for 24h post space preparation after 24 hrs, filling material of the cervical and middle thirds was removed with pesso drills no.1, and the canal walls of each specimen were enlarged with low speed frc postec® plus drills no.3 under copious water cooling, following the manufacturer’s instructions, creating (8mm) deep post space measured from the coronal end of the root (6), keeping at least 5mm of guttapercha apically (7). the length of the post drill was measured by the endomeasuring block and marked with rubber stopper; post space preparation was done with a low –speed straight handpiece attached to a dental surveyor to obtain vertical preparation with standard diameter and dentinal walls parallel to the long axis of the roots. sample grouping the heavy body mounted roots were randomly assigned into two groups (n=24 each), depending on the type of the resin cement used multilink (n) or relyx™ u100 (r) and then each group is sub-divided into three groups (n=8 each) group r1, tested 1day after cementation. group r2, tested1week after cementation. group r3, tested 2weeks after cementation group m1, tested 1day after cementation. group m2, tested 1week after cementation. group m3, tested 2weeks after cementation post cementation prior to post cementation, the post space was irrigated with 2.5% naocl and then final irrigation was accomplished with (5ml) of distilled water and the post space was dried with paper point. before cementation procedures, each post was marked at a distance of (8mm) from the apical end corresponding to the post space preparation. in this way complete seating of the post could be verified (8). the coronal part of the post (above the marked area) was attached to the dental surveyor (mandrel clamp was fitted to the upper arm to hold the prefabricated post to which the prepared specimens was then fitted) according to manufacturer’s instructions. the cement was mixed and applied on the post, after that the heavy body mounted plastic tube placed on the base of the dental surveyor and the upper arm holding the fiber post was lowered down until the post is fully seated inside the post space. excess of luting agent was immediately removed with a small brush. a constant load of 2.5 kg was applied for 60 sec. using the custom-made loading apparatus to stabilize the fiber posts in position. the specimens were sealed with temporary restoration, all stored in distilled water, for groups r1, m1 the samples were stored in the incubator for 24 hours, for groups r2, m2 the samples were stored for 1 week and for groups r3,m3 the samples were stored for 2weeks, all the samples were stored at 37º c temperature and 100% humidity in the incubator preparation of the specimens for push-out test disposable plastic syringes were used as molds into which the freshly prepared acrylic paste was loaded. before loading the syringes with acrylic, the apical end of the roots were fixed on the face of the plastic piston of the syringes with a resin adhesive as recommended by the manufacturers, so that the roots would be almost centrally located within the acrylic blocks and to ensure that the sectioning would be almost perpendicular to the long axis of the roots. after loading the syringe with the freshly prepared workable acrylic paste the piston of the syringe with the root fixed on its apex was pushed into the j bagh college dentistry vol. 25(3), september 2013 comparison of regional restorative dentistry 21 acrylic paste with gentle pressure to allow the complete embedding of the root into the acrylic, and to allow the escape of the excess material through the opened syringe tip. the material was allowed to cure under cooled water, cooled water was necessary to compensate for the anticipated rise in the temperature of the samples subsequent to the exothermic curing reaction of the cold cure resin. the acrylic molds were allowed to cure completely for at least 30min as recommended by the manufacturers (9). root sectioning the sectioning of the root was made by using diamond wheel bur mounted on straight hand piece and engine with a rotation speed regulator, the hand piece was assembled in a cutting device. the cuts were made under heavy flow of cold water (19-25°c) to minimize smearing (9). from each specimen, 3 post/dentin sections (coronal, middle, and apical) were obtained, each 2 mm thick. thus, each study group of 8 roots provided a total of 24 test specimens, consisting of 8 specimens from each of the 3 different post space regions. the exact length of fiber post segments in each section was measured using a digital vernier (10). then each slice was marked on its apical side with marker pen to make sure that the load will be applied in apico-coronal direction due to the conical shape of the frc post used in the study. then the slices from each root region was stored in a plastic container and labeled push-out bond strength test push-out tests were performed by applying a compressive load to the apical aspect of each slice via a cylindrical plunger mounted on tinius-olsen universal testing machine managed by computer software. because of the tapered design of the post, two different sizes of punch pin: 1.0 mm diameter for the coronal, 0.6 mm for the middle and apical slices, were used for the push-out testing. the punch pin was positioned to contact only the post, without stressing the surrounding root canal walls (11). the specimens were placed inside the mold with its apical direction upward and the coronal direction downwards because the load should be applied to the apical aspect of the root slice and in an apical–coronal direction, so as to push the post towards the larger part of the root slice, thus avoiding any limitation to the post movement. loading was performed at a crosshead speed of 0.5 mm/ min until the post segment was dislodged from the root slice (12). a maximum failure load value was recorded (n) and converted into mpa, considering the bonding area (mm²) of the post segments. the apical and cervical diameters of the root canal post of each slice were measured using an optical microscope managed by computer software. three slices from different levels of the same tooth were placed and examined under the optical microscope (magnification 50x) to measure the diameter of the coronal and the apical surfaces, two readings (diameter) were obtained from each surface; after that the average of the readings was used as a post surface diameter, from which the radius was calculated. the bonding surface was calculated using the formula of a conical frustum (13). π (r1+r2) )(r1-r2)π2 +h2 where r1 represents the coronal post radius, r2 represents the apical post radius and h is the thickness of the slice results all statistical analysis was performed using commercially available software (spss for windows) version 15. the level of significance was 0.05 push out test the mean push-out bond strength of resin cements in different root regions are shown in (figures 1, 2 and 3). it’s obvious that the mean push-out bond strength (mpbs) of the multilink n is higher than that of relyx u100 in all three regions at all intervals . it’s also clear that the coronal region in both resin cements have higher mpbs values, followed by middle and apical regions. the highest mpbs seen at the coronal region of multilink n after 2 weeks while the lowest value seen at the apical region of the relyx u100 resin cement after 24 h. statistical analysis of data by using the anova test revealed that there was a significant difference (p<0.05) among different regions within each resin cement except for the coronal region of multilink n between group 1, 2 and 3 there was no statistical difference. discussion the results of this in vitro study require the rejection of the null hypothesis that cement type and the testing time have no effect on the interfacial strength of the luted fiber posts. the bond strength of fiber post in cervical, middle and apical region both adhesive cements tested demonstrated measurable adhesion to root dentin, with the highest values for the coronal region and lowest for the apical region the explanation for this result could be attributed to different factors such as the gradual decease in the number of the dentinal tubules from the coronal to the apical part of the root thus the reduced infiltration of the adhesive into the tubules and less formation of the resin tags in the apical parts, and because the adhesion j bagh college dentistry vol. 25(3), september 2013 comparison of regional restorative dentistry 22 is enhanced by penetration of the resin into the tubules, its values is low at the apical third. this coincides with zorba et al. (7) who stated that the difference in the number of tubules may explain why the strongest adhesion occurred in the most coronal sections where there is a greater number of tubules per square mm, but the result findings conflict with foxton et al. (14) who stated that the apical bond strength was significantly higher in the apical region because the bond strength is related more to the area of solid dentin than to the tubule density and when the post space were created, the rotary drill created a smear layer on the dentin surface, the use of a brush or irrigant to clean the debris from the post space may have removed some, but not all, of the superficial layer in the cervical and middle third, but it didn’t reach the apical third and this smear layer formation during the post space preparation that could not be removed by naocl irrigation. in 2005, foxton et al. (14) prepared the post space without previous endodontic treatment; also they didn’t use any irrigation solution (naocl). in 2001, morris et al. (15) reported the biomechanical behavior of root canal dentin would have been different if it had been endodontically treated or treated with naocl. other factor is that the coronal portion of the canal is the most accessible part of the canal space making it easier to etch and more thoroughly apply the adhesive agent than in deeper area of the canal the effect of time on the bond strength of fiber post the study findings revealed a significant increase in bond strength values when the specimens are tested 1 week and 2 weeks after post space preparation and post cementation, this behavior is probably caused by the water sorption and subsequent hygroscopic expansion of the cements and/or by continuation of its setting reaction. hygroscopic expansion occurs within water-based cements, two distinct phases of reaction occur in these water-based materials, the initial phase utilizes water that is present originally within the mixed cement. once this water is consumed, the second phase can only occur when water is available from either the underlying dentin (16) or the external environment. additionally, evidence has been collected that the availability of water during the maturation phase of the cement materials leads to the formation of a distinct silica rich phase that contributes to a gradual increase in mechanical properties with time (17). such a phenomenon might have increased the frictional resistance of the cements against the root canal walls and, subsequently, improved fiber post retention. this is in agreement with reis et al. (18) who stated that the effective retention mechanism for fiber posts to the root canals is largely derived from sliding friction of the cement against the internal walls of root canals instead of true adhesion to intraradicular dentin. comparison of push test values between the self-cure and dual cure resin cement this study revealed that the bonding strength values of the self-curing resin material is higher than the dual cure resin material, this might be attributed to several factors, one of them is that the type of post employed, the frc post used in this study is produced by the same manufactures of the self-cure resin cement (multilink n) which make it a full system pack and more compatible. and because the dual cure resin cement (relyx u 100) is alight polymerized adhesive its bonding strength values is compromised at the apical and middle regions of the root where the curing light might not reach, while the self-cure cement (multilink n) is a self-cure resin with a light curing option in which the main reaction is chemical and its polymerization can be further enhanced achieved by the light cure. the findings of this study coincides with study by behr et al. (19) which revealed the self-activating system showed a more uniform resin tag and resin-dentin inter-diffusion zone formation along root canal walls than dual-curing systems, while other conflict with this study such as da silva et al. (4) that revealed in her study that the bonding strength values of dual cure resin is higher than of self-cure resin cement. this might be due to methodological variation. additionally, the multilink n (self-cure) require salinization of the post with mono bond s which serves as a bonding agent and create a durable chemical bond between the frc post and the resin cement, this is in agreement with goracci et al. (11) who stated that the bond strength between the frc post and the resin cement is significantly improved when using a silane ,while disagree with bitter et al. (20) who stated that in push-out tests the bond strength of the resin cement to the frc posts were not significantly affected by silanization. references 1. duret b, reynaud m, duret f. a new concept of corono-radicular reconstruction: the composipost (2). chir dent fr 1990; 60(542):69-77. 2. hattori m, takemoto s, yoshinari m, et al. durability of fiber-post and resin core build-up systems. dent mater j 2010; 29(2): 224–228. 3. reid lc, kazemi rb, meiers jc. effect of fatigue testing on core integrity and post microleakage of j bagh college dentistry vol. 25(3), september 2013 comparison of regional restorative dentistry 23 teeth restored with different post systems. j endod 2003; 29:125-31. 4. da silva rat, cotinho m, cardozo pi, da silva la, zorzatto jr. conventional dual-cure versus selfadhesive resin cements in dentin bond integrity. j appl oral sci 2010; 11:1-8. 5. goracci c, tavares au, fabianelli a, monticelli f, raffaelli o, cardoso pc, tay f, ferrari m. the adhesion between fiber posts and root canal walls: comparison between microtensile and push-out bond strength measurements. eur j oral sci 2004; 112(4):353-61. 6. mauricio pj,lopez sg, mendoza ja,felix s, gonzalez-rodrıguez mp. comparison of regional bond strength in root thirds among fiberreinforced posts luted with different cements. j biomed mater res b appl biomater 2007; 23(2):36472. 7. zorba yo, erdemi a, turkyilma a, eldeniz au. effects of different curing units and luting agents on push-out bond strength of translucent posts. am associ endod 2010; 36(9):1521-5. 8. d'arcangelo c, zazzeroni s, d'amario m, vadini m, de angelis f, trubiani o, caputi s. bond strengths of three types of fibre-reinforced post systems in various regions of root canals. j endod 2008; 41(4):322-8. 9. gencoglu n, garip y, bas m, samani s. comparison of different gutta-percha root filling techniques: thermafil, quick-fill, system b, and lateral condensation. oral sur oral med oral pathol oral radiol endod 2002; 92(3): 333-6. 10. akgungor g, akkayan b. influence of dentin bonding agents and polymerization modes on the bond strength between translucent fiber posts and three dentine regions within a post-space. j prosthet dent 2006; 95(5): 368–78. 11. goracci c, raffaelli o, monticelli f, balleri b, bertelli e, ferrari m. the adhesion between prefabricated frc posts and composite resin cores: microtensile bond strength with and without postsilanization. dent mater 2005; 21(5): 437-44. 12. vano m, cury ah, goracci c, chieffi n, gabriele m, tay fr, ferrari m. the effect of immediate versus delayed cementation on the retention of different types of fiber post in canals obturated using a eugenol sealer. j endod 2006; 32(9): 882–5. 13. bitter k, priehn k, martus p, kialbassa am. in vitro evaluation of push out bond strength of various luting agents to tooth-colored posts. j prosth dent 2006; 95(4): 302–10 14. foxton rm, nakajima m, tagami j, miura h. adhesion to root canal dentin using one and two-step adhesives with dual-cure composite core materials. j oral rehabil 2005; 32(2): 97-104. 15. morris md, lee kw, agee ka, et al. effects of sodium hypochlorite and rc-prep on bond strength of resin cement to endodontic surfaces. j endod 2001; 27(12):753-7. 16. cury ah, goracci c, navarro mfl, sadek ft, tay fr, ferrari m. effect of hygroscopic expansion on the push-out resistance of glass ionomer-based cements used for the luting of glass fiber posts. j endod 2006; 32(6): 537–40. 17. yiu ck, tay fr, king nm, pashley dh, et al. interaction of glass ionomer cements with moist dentin. j dent res 2004; 83: 283-9. 18. reis k, spyrides gm, de oliveira ja, et al. effect of cement type and water storage time on the push out bond strength of a glass fiber post. braz dent 2011;22(5):359364 19. behr m, rosentritt m, regent t, et al. marginal adaptation in dentin of a self-adhesive universal resin cement compared with a well tried systems. dent mater 2004;20:191-7 20. bitter k, meyer-lückel h, priehn k, martus p, kielbassa am. bond strengths of resin cements to fiber-reinforced composite posts. am j dent 2006; 19(3):138-42 fig. 1. mean push-out bond strength of resin cements after 24 h. fig. 2. mean push-out bond strength of resin cements after a week. fig. 3. mean push-out bond strength of resin cements after two weeks j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 32 molar buccal tubes front and back openings dimensions and torsional play hiyam j. al-zubaidi b.d.s. (1) akram f. alhuwaizi b.d.s., m.sc., ph.d. (2) abstract background/: buccal tubes are orthodontic attachments used on the posterior teeth instead of bands, so it is important to focus on the effect of their properties on orthodontic treatment. the aims of the present in vitro study are to evaluate and compare the buccal tube front and back openings dimensions and the torsional play angle of six different brands. materials and methods: the samples consisted of single bondable, non-convertible first molar buccal tubes from six brands supplied from six companies (dentaurum, forestadent, ormco, 3m, american orthodontic, a-star). regarding tube opening dimension, ten buccal tubes of each brand were examined by an optical microscope. each tube was fixed during examination using synthetic mud and oriented for observation of the front and back slot openings. a picture was taken for both tube openings and the result appeared on the computer's screen where width and height measurements were made. while regarding torsional play angle, ten buccal tubes of each brand were used. each tube was fixed on a metal block attached to a surveyor base. then an l-shaped wire was inserted inside the front opening of the tube. two photographs were taken, one with the wire in free fall position and the other wit h the wire elevated by a 10g weight with the same angle of shooting as the first photograph. later, the two images were superimposed in adobe photoshop program, and an electronic mb-ruler software was used to calculate the angle which represents the torsional play within each tube. the data were then statistically analyzed using anova and lsd tests. results: there are marked differences between measured tube dimensions and the manufacturer stated dimensions with the front tube openings being generally larger than the back opening dimensions. furthermore, the torsional play angle was highest in a-star and smallest in ormco's tubes. this angle was significantly correlated to the height of the tube front opening. conclusion: it can be concluded that tube dimension varies among different companies and effect greatly torsional play angle. keywords: buccal tube, tube dimension, torsional play. (j bagh coll dentistry 2018; 30(3): 32-39) introduction the buccal tube is a metal tube fixed to the facial (buccal) surface of an orthodontic molar band or directly to the surface of the tooth which allows the arch wire to pass through while applying either a torqueing force or allowing the wire to slide as tooth movement occurs (1). there are four basic types of buccal tubes available: 1. mandrel formed the tube is pressed and machine-folded to the required size. 2. drilled formed the tube is machine-formed and drilled to the size. 3. mim (metal injection mold) formed the tube with its slot created by milling machine, which consider as an accurate manufacturing process. 4. the cnc machine using computer numerical control machining (2,3). in orthodontics, the effect on a tooth of the force delivered by a twisted (torqued) wire represents the "torque". torsion is the actual twisting that results from torque (4). 1ministry of health, baghdad, iraq 2 professor, department of orthodontics, college of dentistry, university of baghdad, baghdad, iraq oversized slots lead to a clinically relevant torque loss. if torque control with rectangular wire is needed, the wire should have a close engagement with the tube lumen (5). proffit et al. (6) stated that “oversize slots undermine the whole basis of pre-adjusted edgewise, which is intended to minimize wire bending”. he further stated that there should be a reasonable anticipation that the appliance accuracy should be exactly as appealed in advertising brochures. while theoretical tooth positions or prescription values may be debated, few have questioned whether a specific bracket or bracket series is even capable of moving the tooth to the desired position. orthodontic bracket slot profile variances have an impact on torque play and third-order torque expression (7,8). meling et al. (5) used torque play to measure slot height indirectly in an attempt to overcome the difficulties of measuring non rectangular profiles. cash et al. (9) measured bottom and top slot height and suggested that different bracket types have different slot shapes. when a smaller dimension wire is used in a slot there would be a gap between the slot walls and the j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 33 wire. this gap will cause certain rotation or free play of the wire in the slot. because of this play or free space, not all the torque built within the bracket is expressed on passing the wire. to express the required amount of torque either we have to introduce torque or torsion in the wire by pliers or have to use a bracket with extra torque built within to accommodate the amount of play of the wire. the amount of torsion in the wire or extra torque built within the bracket should be equal to the amount of play of the wire with in the slot. torque or wire play is affected by manufacture tolerance of slot and wire, edge bevel of slot and wire, mechanotherapy, type of ligation, defects in brackets slot, and aging of brackets (10). materials and methods this in vitro study focused on upper first molar buccal tube made by six different international companies in which samples were tested to measure slot dimension and torsional play within the slot. one hundred and ten single bondable, nonconvertible first molar buccal tubes from six companies, ten tubes form each company were used in this study. all the tubes had an mbt 0.022 prescription and from the following companies: 1dentaurum (dentaurum, ispringen, germany). 2forestadent (forestadent, pforzheim, germany). 3ormco (ormco, california, usa). 43m (3m unitek, monrovia, california, usa). 5ao (american orthodontics, washington avenue, sheboygan, usa). 6a-star (a-star orthodontics inc., shanghai, china). slot dimension measurement: sixty buccal tubes of upper first molar from six different companies were used for this test (ten from each company). each tube was fixed during examination using synthetic mud and oriented for observation of the front and back slot openings using a metallurgic optical microscope (olympus, japan) (fig. 1). a picture was taken for the front and back openings of the tube and the result appeared on the computer's screen where width and height measurements were made (fig. 2). figure 1: method of tube's fixation during slot dimension examination. figure 2: the optical microscope. torsional play test: a cnc machine (cnc freza, japan) which is a computer controlled machine was used to make 30 steel blocks (6 x 1.2 x 1.2 cm in dimension). eighteen blocked were used for the torsional play test on which the molar tubes were fixed and the torsional play was measured. ten sections of 0.021'' x 0.025'' straight stainless steel archwires (dentaurum, ispringe, germany) were cut. each wire was 3 inches long and the 0.5-inch end was bent at 90 degrees to be inserted in tube's opening in accordance with bennett and mclaughlin (3) (fig. 3). a half circle was made at the end of long side of the wire. fifty buccal tubes of upper first molar were collected from five companies (10 tubes for each j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 34 company). they were fixed on the prepared blocks and the blocks were attached to the surveyor base which was kept parallel to the floor. then the prepared wire was inserted inside the front opening of the tube and permitted to fall freely and a photograph was taken in this position (fig. 4a). after that a 10g weight was tied to a thread placed around the horizontal arm of the surveyor. the other end of the thread was tied to the end of the wire (fig. 4b). as a result, the wire was elevated till it engaged with the tube slot and another photograph was taken with the same angle of shooting as the first photograph. later, each two images were superimposed in adobe photoshop program and transformed into one photograph, and then an electronic mb-ruler (markus bader) software was used to calculate the angle which represents the torsional play within each slot (fig. 5). figure 3: the wire used in the torsional play test. (a) (b) figure 4: the wire in two positions: (a) in free fall and (b) after application of 10g weight. figure 5: the two photographs after being edited in adobe photoshop and the angle measured by mbruler. statistical analysis: data were collected and analyzed using spss (statistical package of social science) software version 24 for windows 10 (chicago, usa). least significant difference (lsd) was used to test any statistically significant differences between each two subgroups when anova test (one-way analysis of variance) showed a statistical significant difference within the same group. a p-level of more than 0.05 was regarded as statistically non-significant. while a p-level of 0.05 or less was accepted as significant. results the data obtained from the present experimental study were managed statistically to compare and explain the tube dimension and the torsional play differences between six different brands of upper first molar tubes. these statistics included mean, standard deviation, standard error, minimum, and maximum values. normality of data distribution: it was found that all data of this experimental study including the tube dimension and torsional play tests were normally distributed because the pvalue of shapiro-wilk test is greater than 0.05 which mean non-significant. tube dimensions for front opening: table 1 illustrate the mean and standard deviation of the measured molar tube front opening dimensions (height and width) for the six tested brands. a-star molar tubes showed front opening dimensions markedly larger than the standard dimensions (22 mil height and 30 mil width) by 1.8-2.6 mil. also, 3m molar tubes showed front tube opening dimensions larger than the standard dimensions by 1-1.6 mil. while, american orthodontics molar tubes had front opening dimensions is larger in height by 1.2 mil but with a normal width. j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 35 dentaurum molar tubes showed front openings slightly larger in height (1 mil) but smaller in width (0.7mil) which is similar to the same results of forestadent molar tubes that showed front openings that are higher than standard one by 1.4 mil and narrower by 1.5 mil. finally, ormco molar tubes showed slightly larger dimensions than standard by 0.7-0.9 mil. regarding consistency, all the tested molar tubes from the 6 brands had front openings with a height more than the 22 mil standard. moreover, height was more consistent than width with range values of 0.6 to 0.9 and 0.6 to 2.1 respectively. the highest variation was observed in a-star and dentaurum and forestadent width measurement of about 2 mils. table 1: dimensions of the molar tubes front opening. height width mean s.d. mean s.d. 3m 23.640 0.196 31.030 0.221 as 23.780 0.326 32.590 0.638 ao 23.210 0.197 30.020 0.187 de 23.077 0.230 29.270 0.730 fr 23.430 0.320 28.470 0.263 or 22.890 0.242 30.690 0.318 * all measurements are in mil. tube dimensions for back opening: table 2 illustrate the mean and standard deviation of the measured molar tube back opening dimensions (height and width) for the six tested brands. regarding a-star molar tube, the back opening dimensions were markedly larger than the standard dimensions (0.9-2.4 mil). ormco and 3m molar tubes both showed back tube opening dimensions similar to the standard dimensions differing by only 0.2 to 0.4 mil. on the other hand, american orthodontics, dentaurum and forestadent molar tubes all showed back opening which are considerably narrower than the standard width 30 mil. however, in them differ height. forestadent tubes have a larger height dimensions, dentaurum tubes have similar heights to the standard 22 mil, while american orthodontics tubes have smaller height dimensions making them much smaller in both height and width than the standard dimensions (1.1 to 2.1 mil) as shown in figure 6. difference in the dimensions of the molar tubes front and back opening: table 3 and figure 7 illustrate the mean and standard deviation of the difference in the dimensions of the molar tubes front and back openings for the six brands tested in the study. american orthodontics, showed the highest differences between back and front tube openings in range 2.1-2.3 mil. while, 3m molar tubes showed slight differences between front and back dimensions in comparison with the stated dimensions about 0.7-1.4 mil. a-star, ormco and dentaurum molar tubes showed nearly the same range of differences between back and front tube dimensions in comparison with the stated dimensions (0.2-0.9 mil). forestadent molar tubes showed the least differences in back and front dimensions as compared to the stated dimensions (0.2-0.5 mil). table 2: dimensions of the molar tubes back opening. height width mean s.d. mean s.d. 3m 22.210 0.401 30.360 0.190 as 22.875 0.487 32.400 0.594 ao 20.880 0.270 27.920 0.270 de 22.160 0.227 28.650 0.268 fr 22.930 0.221 28.270 0.271 or 21.990 0.303 30.250 0.327 * all measurements are in mil. figure 6: scattered diagram of the mean height and width of the molar tube front (●) and back (■) openings. table 3: the difference in the dimensions of the molar tubes front and back openings. height width mean s.d. mean s.d. 3m 1.430 0.481 0.670 0.353 as 0.905 0.614 0.190 1.019 ao 2.330 0.337 2.100 0.226 de 0.917 0.298 0.620 0.678 fr 0.500 0.249 0.200 0.275 or 0.900 0.298 0.440 0.515 * all measurements are in mil. 3m a-star dentaurum forestadent ormco j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 36 figure 7: mean difference between the molar tube front and back openings dimensions. difference between molar tube brands for front and back openings dimensions: anova test for both tube dimensions showed a highly significant differences among buccal tubes of the six brands (table 4). lsd test was performed for comparison between each two brands for height and width of the molar tube front and back tube openings and the results are displayed in table 5. the differences between the brands were all statistically significant with only some exception, most notable are between ormco tubes on one hand and 3m tubes and dentaurum tubes on the other. table 4: statistical difference between the six brands for height and width of the molar tube front and back openings by anova test. f sig. front width 104.467 0.000*** height 17.531 0.000*** back width 240.544 0.000*** height 50.116 0.000*** *** p<0.001 table 5: statistical difference between each two brands for height and width of the molar tube front and back openings by lsd test. front back width height width height 3m as 0.000*** 0.229 0.000*** 0.000*** ao 0.000*** 0.000*** 0.000*** 0.000*** de 0.000*** 0.000*** 0.000*** 0.738 fr 0.000*** 0.074 0.000*** 0.000*** or 0.094 0.000*** 0.479 0.145 as ao 0.000*** 0.000*** 0.000*** 0.000*** de 0.000*** 0.000*** 0.000*** 0.000*** fr 0.000*** 0.004** 0.000*** 0.713 or 0.000*** 0.000*** 0.000*** 0.000*** ao de 0.000*** 0.253 0.000*** 0.000*** fr 0.000*** 0.061 0.027* 0.000*** or 0.001** 0.007** 0.000*** 0.000*** de fr 0.000*** 0.003** 0.017* 0.000*** or 0.000*** 0.110 0.000*** 0.258 fr or 0.000*** 0.000*** 0.000*** 0.000*** * p<0.05, ** p<0.01, *** p<0.001 torsional play of the molar tubes: table 6 revealed the mean and standard deviation values of torsional play test of molar tubes for five companies excluding ao molar tubes. ao tubes were not measured because the 21 x 25 mil wire did not exit from the back opening of the tube. the means for torsional play test of all molar tubes ranged from 14.5° for a-star (highest torsional play) to 8.927° for ormco (lowest torsional play). table 6: molar tubes torsional play. mean s.d. 3m 13.625° 0.655° as 14.536° 0.268° de 10.634° 0.245° fr 14.328° 0.651° or 8.927° 0.053° statistical difference for torsional play test: anova test was performed to demonstrate the statistical difference between the five brands for torsional play of the molar tubes and showed a highly significant difference among molar tubes (f=315.754, p=0.000). lsd test was performed for comparison between each two types of molar tubes and the results are displayed in table 7. torsional play showed significant differences between the brands except between forestadent and a-star. table 7: statistical difference between each two brands for the torsional play of the molar tubes by lsd test. p level 3m as 0.000*** de 0.000*** fr 0.001** or 0.000*** as de 0.000*** fr 0.301 or 0.000*** de fr 0.000*** or 0.000*** fr or 0.000*** * p<0.05, ** p<0.01, *** p<0.001. correlation between variables: all the variables were correlated with each other and displayed non-significant correlations except between torsional play and the molar tube front opening height which showed a significant correlation (fig. 8). the data lie of all six brands of molar tube lie near a straight line which indicate a positive correlation. 3m a-star dentaurum forestadent ormco j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 37 pearson correlation= 0.924, p = 0.025 (p<0.05) figure 8: scattered diagram of the torsional play with the tube height of the molar tube. discussion due to the scarcity of researches on molar tubes some comparisons will be made with researches done on passive self-ligating brackets. according to seo, passive self-ligating bracket used has a flat and rigid buccal slide made of stainless steel, which makes the slot configuration as a rectangular tube and maintains slot dimension even in an active configuration (11). as the tubes resemble passive self-ligating bracket so the studies on slb can be compared to this current study. tube dimensions: in this study, the tube dimension was measured by using metallurgic optical microscope in which the tube was fixed by using synthetic mud with the slot oriented vertically so that the line of view with the measuring microscope was parallel to the slot axis and this method have been previously reported by (12) in which the brackets were placed on a microscope slide using rope wax with the slots oriented vertically so that the line of view with the measuring microscope was parallel to the slot axis. the slide was then placed on the microscope table and the slot and light adjusted until a sharp, well-focused image was viewed on the screen and digitally captured and then two screenshots from the automatic reading system showing a bracket with rounded internal line angles and another with a divergent slot. the digitally imaged bracket is automatically scaled and loaded into the measuring software. tube opening dimensions: none of the tested tubes matched the stated dimensions given by the manufacturer with a trend showing larger dimensions for all front openings of tested tubes. this inconsistency in tube and bracket dimensions and inability of manufacturer to produce the slots precisely have been previously reported by (13-16). in general, the molar tube's front opening height was found to be larger than the stated dimensions but more regular than the width. according to previous studies which measured the actual slot configuration of pslb (passive self ligating bracket) is known to have narrower width, longer height, deeper depth and consequently larger critical contact angle (θc) when compared to aslb (active self ligating bracket) (1719). this study showed that there is a difference between back and front opening dimension for the same tube. these findings supported by many other studies on bracket slot dimensions which revealed nearly the same results including the differences in bracket slot width between top and base and differences in slot dimensions for the brackets from the same company (9). finally, american orthodontics tubes founded to be smaller in both height and width of back opening in comparison with the other companies because of that it showed the highest differences between the front and back opening ant this result may be related to the method of manufacturing since it was mentioned previously in the ao buccal tube catalog that low profile buccal tubes are reduced in size by 25% over standard sized tubes. lp® tubes feature smooth contours for patient comfort, a funneled mesial opening for easy wire insertion, and occlusal/gingival positioning guides designed to make bonding easier at the posterior. torsional play test: when an undersized wire is inserted, the wire can rotate in slot of attachment. this angle of freedom is called play and it would increase as the differences in size between the slot and wire (20). in this study, a-star had higher torsional angle and ormco had the least torsional angle. these results can be related to the differences in tube dimension among the tested brands. a-star tubes showed higher dimension which can be considered the cause for higher torsional angle. while, ormco tubes showed the smallest dimensions and least torsional angle. many studies demonstrated that in reality, torque loss is higher because the dimensions of the slot aren't 100% precise. as measured by several authors, the dimension of the slots tends to be mostly larger than stated (7,8,9,15,21). according to several authors, the mean engagement angle measured was greater than the theoretical engagement angle because the bracket slot dimensions were larger than stated dimensions (7.22,23). in a 0.022-inch bracket slot, the nominal values for play are 1.74 degree according to dellinger (24) and 3.9 degree according to creekmore (25) for a 0.021 * 0.025 inch archwire. while in the current study, the torsional play of all molar tubes ranged from 14.5° for a-star to 8.927° for ormco so these result can be explained by the larger dimensions of a-star tubes than stated dimensions and ormco showed a slightly larger dimensions of front opening but the same dimensions of back opening when compared with the stated ones. 3m a-star dentaurum forestadent ormco j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 38 tube height is more important in relation to the torsional play since the height is smaller than width so any simple change in height will greatly show an effect on the torsional play degree. limitation of the study 1. there is limited information from the manufacturers regarding the manufacturing process of making molar tubes especially the nature of the slot inner surfaces. 2. molar tubes from american orthodontics were not tested for torsional play because it was not possible to insert a 0.021” x 0.025’ wire which used for testing because of the small back opening. clinical consideration: 1. the orthodontist must be aware about the inaccuracy of the stated slot dimensions of the molar tubes mentioned by the manufacturer. 2. using a 0.021” x 0.025” stainless wire is a simple technique to examine the precision of the size of the tube openings. conclusions: 1. the measured tube dimensions do not match those stated by the manufacturer. 2. there are large differences between front and back openings dimension. 3. torsional play angle is significantly related to tube opening height. references 1. jones jr jh, kantor g, stevens md, watt de. convertible buccal tube. us patent 6 2002; 428-314 b1. 2. raphael e. angular rotation of rectangular wire in rectangular buccal tubes. loyola university chicago, master thesis, 1978. 3. bennett j and mclaughlin. fundamentals of orthodontic treatment mechanics. london, uk: legrande publishing 2014; 1st ed, 4. thurow cr. edgewise orthodontics. mosby, st. louis 3rd ed, 1972; p.35-7, 160-70, 181-7. 5. melling tr, odegaard j, seqner d. on bracket slot height: a methodologic study. am j orthod dentofacial orthp 1998; 113(4): 387-93. 6. proffit wr, fields hw jr, sarver dm. contemporary orthodontics. 5th ed. st. louis: elsevier health sciences, 2014. 7. fischer-brandies h, orthuber w, es-souni m, meyer s. torque transmission between square wire and bracket as a function of measurement, form and hardness parameters. j orofacial orthop 2000;.61(4): 258-65. 8. gioka c, eliades t. materials-induced variation in the torque expression of preadjusted appliances. am j orthod dentofacial orthop 2004; 125(3): 323-8. 9. cash c, good sa, curtis rv, mcdonald f. an evaluation of slot size in orthodontic brackets are standards as expected? angle orthod 2004; 74(4): 4503. 10. khan h. orthodontic brackets selection, placement and debonding. orthodontic book, 1st ed, 2016. 11. seo yu-jin, bum-soon lim, young guk park, ilhyung yang, seok-joon ahn, tae-woo kim, seunghak baek. effect of self-ligating bracket type and vibration on frictional force and stick-slip phenomenon in diverse tooth displacement conditions: an in vitro mechanical analysis. eur j orthod 2015; 37(5): 474-80. 12. brown p, warren wagner, hyden choi. orthodontic bracket slot dimensions as measured from entire bracket series. angle orthod 2015; 85(4): 678-82. 13. kusy rp, whitley jq. assessment of second-order clearances between orthodontic archwires and bracket slots via the critical contact angle for binding. angle orthod 1999; 69(1):71-80. 14. bhalla nb, good sa, mcdonald f, sherriff m, cash ac. assessment of slot sizes in self-ligating brackets using electron microscopy. aust orthod j 2010; 26(1): 38-41. 15. major tw, carey jp, nobes ds, major pw. orthodontic bracket manufacturing tolerances and dimensional differences between select self-ligating brackets. j dent biomech. 2010; 2010: 781321. 16. daratsianos n, bourauel c, fimmers r, jäger a, schwestka-polly r. in vitro biomechanical analysis of torque capabilities of various 0.018″ lingual bracket– wire systems: total torque play and slot size. eur j orthod 2016; 38(5): 459-69. 17. thorstenson ga, kusy rp. effect of archwire size and material on the resistance to sliding of self-ligating brackets with second-order angulation in the dry state. am j orthod dentofacial orthop 2001; 122(3): 295305. 18. chang cj, lee tm, liu jk. effect of bracket bevel design and oral environmental factors on frictional resistance. angle orthod 2013; 83(6): 956-65. 19. nucera r, lo giudice a, matarese g, artemisia a, bramanti e, crupi p, cordasco g. analysis of the characteristics of slot design affecting resistance to sliding during active archwire configurations. prog orthod 2013; 14:35. 20. meling tr, ødegaard j. the effect of cross-sectional dimensional variations of square and rectangular chrome-cobalt archwires on torsion. angle orthod 1998; 68(3): 239-48. 21. siatkowski r. loss of anterior torque control due to variations in bracket slot and archwire dimensions. journal of clinical orthodontics: j clin orthod 1999; 33(9): 508-10. 22. sebanc j, brantley wa, pincsak jj, conover jp. variability of effective root torque as a function of edge bevel on orthodontic arch wires. am j orthod 1984; 86(1): 43-51. 23. meling tr, odegaard j, meling eo. on mechanical properties of square and rectangular stainless steel wires tested in torsion. am j orthod dentofacial orthop 1997; 111(3): 310-20. 24. dellinger el. a scientific assessment of the straightwire appliance. am j orthod. 1978; 73:290–299. 25. creekmore td. dr. thomas d. creekmore on torque. j clin orthod. 1979; 13:305–310. :ةالخالص j bagh college dentistry vol. 30(3), september 2018 molar buccal tubes 39 لى تأثير التركيز ع لذا من المهم ةبدال من الحلقات المعدني ةتستعمل في االسنان الخلفي ةكمرتكزات تقويمي ةاألنابيب الشدقي الدراسة:الغرض من ةأللتوائيا ةهي تقييم ومقارنة قوة األحتكاك الثابت وحجم االنبوب ودرجة الحرك ةالمختبري ةأهداف هذه الدراس. خصائصها في مجال العالج التقويمي .ة( شركات مختلف6لألنبوب التقويمي االول العلوي من ) بالنسبه لقياس حجم فتحة األنبوب، .شركات 6للضرس األول من ةللصق، غير متحول ةقابل ةمفرد ةأنابيب شدقي ةأستعملت في هذه الدراس :الطريقة خالل الفحص بأستخدام الطين األصطناعي ونٌظمت من أجل تثبيت كل أنبوبتم وئي.ثمبواسطة المجهر الض ةمن كل شرك ةأنابيب شدقي 01تم فحص لفتحتي األنبوب وظهرت النتائج على شاشة الكومبيوترحيث تم قياس العرض ةلألنبوب. وقد ألتقطت صور ةوالخلفي ةمالحظة الفتحات االمامي بعد ذلك تم ادخال سلك ((surveyor بقاعدة جهاز ةُمثبت ةمعدني ةعلى قطع حيث تم تثبيت كل أنبوب ،ةاأللتوائي ةلزاوية الحرك ةبالنسب واالرتفاع. لألنبوب بعدها تم التقاط صورتين، احداها مع سلك بوضع السقوط الحر واالخرى مع سلك مرفوع بواسطة ةاألمامي ةداخل الفتح ( (lعلى شكل حرف وتم استخدام (adobe photoshop program) االولى. بعد ذلك تم دمج الصورتين بواسطة ةغم مع نفس زاوية التصوير للصور01وزن مقداره .lsd و anovaتحليل النتائج احصائيا بأستخدام أختبار تم. داخل كل أنبوب ةاأللتوائي ةالتي تمثل الحرك ةلحساب الزاوي mb-rulerبرنامج نابيب المقاسه والحجم المتعارف عليه من قبل المصنع مع كون الفتحه األماميه لألنبوب اظهرت النتائج بوجود اختالف واضح بين حجم االالنتائج: واألقل مع شركة ((a-starهي األعلى مع شركة ةااللتوائي ةأكبر بشكل عام من ابعاد الفتحه الخلفيه. باألضافه الى ذلك، كانت زاوية الحرك ormco)). لألنبوب. ةاألمامي ةبشكل اساسي بأرتفاع الفتح ةكانت مرتبط ةهذه الزاوي داخل األنبوب. ةيااللتوائ ةوهناك تاثير كبير على درجة الحرك ةالشركات المختلف يمكن األستنتاج بان ابعاد االنبوب تتغير ضمن قياسات :األستنتاج j bagh college dentistry vol. 29(1), march 2017 serum level of tnfα oral and maxillofacial surgery and periodontics 104 serum level of tnf-α and il-17 in patient have chronic periodontitis associated rheumatoid arthritis munir nasr hamed, b.d.s.(1) basimagh. ali, b.d.s., m.sc.(2) abstract background: chronic periodontitis and rheumatoid arthritis are widely prevalent diseases and are characterized by tissue destruction due to chronic inflammation. recently, there is growing evidence that the two diseases share many pathological features the aims of the study to determine the periodontal health status in patient have chronic periodontitis with rheumatoid arthritis and compare it with those having chronic periodontitis without rheumatoid arthritis and determine the serum levels of interleukin -17(il-17), tumor necrosis factoralpha (tnf-α ) in both groups and compare with the control group (subject samples neither have periodontitis nor arthritis ) and correlate these immunological markers with the periodontal parameters plaque index , gingival index , bleeding on probing, probing depth, clinical attachment level and number of missing teeth. materials and methods: eighty (80) males and females subjects with age range (30-45) years were recruited in this study they were divided into three main groups the chronic periodontitis with rheumatoid arthritis group consist of thirty (30) subjects and second group consist of thirty (30) subjects have chronic periodontitis and third group consist of twenty (20) subject case control group. all subjects had normal weight and height range according to bmi (body mass index) that it value is (18.5-25), clinical periodontal parameters used in this study were plaque index, gingival index, bleeding on probing, clinical attachment level index, probing pocket depth and number of missing teeth was measured in all groups at four surfaces of all presented teeth blood samples were collected from all individuals and examined to determined serum level of interleukin -17 and tumor necrosis factor-a by mean of enzyme-linked immune–sorbent assay. results: the present study showed patients with chronic periodontitis and rheumatoid arthritis had higher prevalence of sites presenting dental plaque, a higher rate of gingival inflammation and bleeding on probing greater probing depth, greater attachment loss and high number of missing teeth compared to those had chronic periodontitis only and control subjects . also highly significant differences between studied group regarding serum level of il-17 and tnf-α atp < 0.001, as well as, it revealed that mean serum levels of il-17 were statistically higher in chronic periodontitis with rheumatoid arthritis group (607.9 ± 79.9) than chronic periodontitis group (421.4 ± 5.9) and control groups (15.9 ± 2.7) similarly serum level of tnf-α (402.2 ± 41.2 319.4 ± 526 85.3 ± 4.9) respectively at p < 0.001. regarding correlation, the current study observed strong positive correlation between serum levels of il-17 andtnf-α with pl.i, gi, bop, ppd cal and the number of missing teeth in the pra at p<0.001. also this study reveal significant correlation between the two immunological markers (tnf-α and il-17) in chronic periodontitis with rheumatoid arthritis group and in chronic periodontitis group. conclusion: it was concluded that there was higher potentiality to chronic periodontitis involvement among rheumatoid arthritis patients, that correlated positively with increase the level of serum levels of il-17 and tnf-α accordingly with high score of clinical parameters that had recorded. that mean tnf –a and il-17 may play an important role in increase the severity of periodontitis as well as rheumatoid arthritis. keywords: chronic periodontitis, rheumatoid arthritis, serum level ,tnf-α , il-17.(j bagh coll dentistry 2017; 29(1):104110) introduction the periodontal diseases range from the relatively simple form of gingivitis to more destructive form of periodontitis, periodontal disease are not only effect the dentition, but may also be a threat to general health(1) . periodontitis, the most common oral disease, is destructive inflammatory disease of the supporting tissues of the teeth and is caused by alveolar bone destruction due to a chronic inflammation (1). (1) master student, department ofperiodontics, college of dentistry, university of baghdad. (2) assistant professor, department ofperiodontics, college of dentistry, university of baghdad. group of specific microorganisms (2).so it was characterized by both connective tissue and rheumatoid arthritis (ra) was another form of a chronic destructive inflammatory disease which is characterized by the accumulation and persistence of an inflammatory infiltrate in the synovial membrane that leads to synovitis and the destruction of the joint architecture resulting in impaired function.it were also associated with inflammatory destruction of joint connective tissue and bone destruction (3). in particular, ra as a chronic inflammatory joint disease carries many characteristics and pathogenetic processes that have similarities to periodontitis. the relationship between rheumatoid arthritis and periodontitis were controversial (4). j bagh college dentistry vol. 29(1), march 2017 serum level oral and maxillofacial surgery and periodontics 105 periodontitis and ra represent an imbalance between pro-inflammatory cytokines and antiinflammatory cytokines, which considered the cause for tissue damage.(5) cytokines were the mean of communication between immune and non-immune cells. hence these cytokines are essential to the pathogenesis of several diseases, including periodontal disease and rheumatoid arthritis. (6) periodontitis had obviously cytokine profiles as that of ra, disease progression is due to continuous and persistence accumulation of proinflammatory cytokines as il-1β and tnf-α together with low levels of il-10 and transforming growth factor β (tgf-β). all might give a good picture for the active stages of both ra and pd (6). the role of pro-inflammatory cytokine, tnf-α, is of special interest for the understanding of immune responses in both ra and pd (7).because of the treatment with antitnf-α medication was commonly used to control the inflammatory process in ra; such therapy may also be relevant for the management of pd (8). the production of il-17 by th17 subset of cd4 t-cell identified in 2003 .it has been associated with the pathogenesis of numerous autoimmune and inflammatory diseases, including rheumatoid arthritis, inflammatory bowel diseases, psoriasis and periodontitis (9). the present study was carry out to study the serum cytokine profile (il-17 and tnf-α) in chronic periodontitis subjects with ra compared to those without ra disease and the influence of the serum levels of these cytokines on clinical periodontal parameters in studied groups. materials and methods the sample in this study consisted of eighty (80) males and females subjects with age range (3545) years. the sample was divided into three groups (chronic periodontitis/rheumatoid arthritis) group(pra) thirty patients (30) diagnosed to have chronic periodontitis disease, and have rheumatoid arthritis. they were from attendants seeking treatment in the rheumatology clinic in baghdad teaching hospital. the rheumatoid arthritis state was diagnosed according to the revised criteria for the classification of rheumatoid arthritis of the american college of rheumatology (10) and also according to the laboratory investigation(esr,latex test). (chronic periodontitis / nonrheumatoid arthritis) group (cp) thirty patients (30) were recruited from the attendants to the clinic of the department of periodontics /college of dentistry /baghdad university.chronic periodontitis in patients was defined as the presence of at least four sites with probing pocket depth ≥4mm with clinical attachment level ≥1-2mm, this made according to the international classification system for periodontal disease (11). (control / systemically healthy) group (c) twenty patients (20) with clinically healthy periodontium and healthy systemic status. this group represents controls. clinical examination: clinical periodontal parameters include {plaque index (pli) silness&loe(12), gingivalindex (gi) loe&silness(13), bleeding on probing (bop), probing pocket depth (ppd), clinical attachment level (cal) and number of missing teeth}. also all subjects had normal range of bmi (body mass index) that it value is (18.5-25)(26). blood collection and biochemical analysis the blood was collected between (9 am-12 pm), the blood samples were taking from their arms from cubital fossa (cubital vein), and put it in a evacuated [ethylene diamine tetra acetic acid (edta)] tubes as anticoagulant tubes, after centrifuging plasma samples preserved immediately into other plain tubes and preserved in freeze (-15cº) until they have been assayed for il-17 and tnf-αby elisa according to manufacturer's protocol of instruction at the raybio il-17 elisa (enzyme-linked immunosorbent assay) kit and tnf-α (human) elisa kit protocol. results clinical analysis high significant differences were found between the mean (pli, ppd and cal) of pra group and cp group by using t-test at p < 0.001 and highly significant (gi) differences found between the same groups table (1). inter group comparison by median of the sites with positive bop presented in table (2) with each group there was high significant difference between sites with positive bop compare to non-bleeding sites. the number of missing teeth between pra group and cp group, using mann– whitney u test at-alpha p <0.05 reveal highly significant difference as shown in table (2). j bagh college dentistry vol. 29(1), march 2017 serum level oral and maxillofacial surgery and periodontics 106 table 1: statistical differences of the periodontal parameters (pli. gi, ppd and cal) among all studied groups. parameters chronic periodontitis rheumatoid arthritis (n=30) chronic periodontitis (n=30) control (n=20) p-value gingival index mean ± sd 1.9 ± 0.3 1.8 ± 0.4 0.5 ± 0.2 <0.001*,ª plaque index mean ± sd 2.1 ± 0.2 1.9 ± 0.3 0.6 ± 0.2 <0.001*,ª probing pocket index mean ± sd 5.2 ± 0.3 4.3 ± 0.5 <0.001*,t clinical attachment level mean ± sd 6.2 ± 0.7 4.1 ± 0.5 <0.001*,t ª anova test, t independent t-test, * significant at alpha level <0.05 table 2: median and significant differences of bleeding on probing and missing teeth for the studied groups. parameters pra group (n=30) cp group (n=30) cgruop (n=20) p-value bleeding on probing median (range) 63 (38-73) 53 (11-71) 8 (6-11) <0.001*, w number of missing teeth median (range) 5 (0 10) 1 (0 4) <0.001*,w kruskal-wallis nonparametric test, w mann-whitney u test * significant at alpha level <0.05 immunological findings the higher values of il-17 were in pra group (607.9 ± 79.9 pg/ml) compare to cp group (421.4 ± 5.9 pg/ml) and c group (15.9 ± 2.7 pg/ml). the current study pointed out that tnf-α reported higher increase in concentration in pra group (402.2 ± 41.2 pg/ml) as compared with cp group (319.4 ± 52.6 pg/ml) and c group (85.3 ± 4.9 pg/ml). using anova test to show significant of statistical difference. it appear that there was a high significant difference for both (il-17 and tnf-α ) among studied groups table (3). lsd test values between each two groups reveal a high significant difference in the level of il-17 and tnf-α p< 0.01 as shown in table (4). table 3: mean and significant differences of the levels of interleukin-17and tumor necrosis factor-alpha among included patients according to their group, n=80. parameters pra (n=30) mean ± sd cp (n=30) mean ± sd c (n=20) mean ± sd p-value level of interleukin17 (pg/ml) 607.9 ± 79.9 421.4 ± 5.9 15.9 ± 2.7 <0.001* tumor necrosis factor-alpha (pg/ml) 402.2 ± 41.2 319.4 ± 52.6 85.3 ± 4.9 <0.001* anova test, * significant at alpha level <0.05 j bagh college dentistry vol. 29(1), march 2017 serum level oral and maxillofacial surgery and periodontics 107 table 4: last significant differences of the levels of interleukin-17and tumor necrosis factoralpha between the included groups accordingly. groups level of interleukin17 (pg/ml) mean ± sd tumor necrosis factor-alpha (pg/ml) mean ± sd pra 607.9 ± 79.9 402.2 ± 41.2 cp 421.4 ± 5.9 319.4 ± 52.6 p-value <0.001* <0.001* pra 607.9 ± 79.9 402.2 ± 41.2 c 15.9 ± 2.7 85.3 ± 4.9 p-value <0.001* <0.001* cp 421.4 ± 5.9 319.4 ± 52.6 c 15.9 ± 2.7 85.3 ± 4.9 p-value <0.001* <0.001* lsd test, *significant at alpha level <0.01 correlations between the immunological parameters and clinical periodontal parameters to each group. the periodontal clinical parameters (pli, gi.ppd, cal) of pra group shown in table (5) have a high positive correlation with immunological parameters (il-17 and tnf-α ) using pearson’s correlation test significant at p <0.01 while the periodontal clinical parameters (bop and the number of missing teeth of pra interleukin -17 have high positive correlation to tnf-α within each of the studied group as shown in the table (6) group have a high positive correlation with immunological parameters (il-17 and tnf-α ) using spearman correlation test significant at p <0.01. accordingly the correlation that shown in cp group exhibit the same correlation between periodontal parameters and immunological parameters as in the pra group. for c group, (gi and pli) get a high positive correlation with serum level of il-17 and tnf-α . table 5: correlation of the levels of interleukin-17and tnf-α with periodontal health parameters according to each group. chronic periodontitis rheumatoid arthritis (pra)(n=30) (gi) p (pli) p (ppd) p (cal) p (bop) s (missing teeth) s il-17 (pg/ml) r 0.880** 0.853** 0.837** 0.922** 0.926** 0.876** p-value <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 tnf-α (pg/ml) r 0.768** 0.711** 0.672** 0.801** 0.847** 0.797** p-value <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 chronic periodontitis (cp) (n=30) (gi) p (pli) p (ppd) p (cal) p (bop) s (missing teeth) s il-17 (pg/ml) r 0.973** 0.958** 0.918** 0.868** 0.895** 0.942** p-value <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 tnf-α (pg/ml) r 0.879** 0.906** 0.928** 0.885** 0.847** 0.906** p-value <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 controls ( c ) (n=20) (gi) p (pli) p (ppd) p (cal) p (bop) s (missing teeth) s il-17 (pg/ml) r 0.889** 0.875** 0.845** p-value <0.001 <0.001 <0.001 tnf-α (pg/ml) r 0.922** 0.939** 0.897** p-value <0.001 <0.001 <0.001 p pearson’s correlation, s spearman’s rho correlation, ** correlation is significant at the 0.01 level (2-tailed). j bagh college dentistry vol. 29(1), march 2017 serum level oral and maxillofacial surgery and periodontics 108 table 6: correlation of between the levels of interleukin-17 and tnf-α within each of the study groups accordingly. groups il-17 (pg/ml) pra (n=30) tnf-α (pg/ml) r 0.844** p-value <0.001 cp (n=30) tnf-α (pg/ml) r 0.900** p-value <0.001 c (n=20) tnf-α (pg/ml) r 0.775** p-value <0.001 pearson’s correlation, ** correlation is significant at the 0.01 level (2-tailed). discussion chronic periodontal disease can be considered a potential focus of infection, which worsens the metabolic control of patients with ra. (14).the pathobiology of periodontal disease) and rheumatoid arthritis is similar, both are inflammatory chronic diseases, with activation of complement, production of cytokines and release of other inflammatory cell products (15, 16).the relationship between periodontal disease and rheumatoid arthritis still controversial (17, 18). current study revealed highly significant differences among the studied groups regarding pl.i; p.p.d; cal and b.o.p, significant level of gi and pli that is probably because patients with ra might be more likely to obtain temporomandibular joint involvement, severe hand dysfunction (caused by arthritis) which hinder the patient’s oral hygiene practices due to restriction of movements, at the same time, decreased saliva from secondary sjögren’s syndrome all enhances plaque accumulation as well as, ra patients may be emotionally depressed about their illness causing the deterioration of the attention to the personal hygiene (19,20). the elevated level of gi and pli reflects a higher inflammation in the pra group than the cp group and could be related to the increase in the plaque as the plaque is the causative factor of gingival inflammation. this result is agreed with (kässer) (20). the percentage of sites with bop was significantly higher in pra group than cp group. the potential altered abilities of ra patients to perform effective oral hygiene could result in an increased bop that exacerbates the risk for enhanced tissue destruction in periodontitis. moreover, interesting observations regarding the complexity of the oral and systemic challenge provide unique mechanisms by which dysregulation of host responses could occur (21). the mean value of ppd and cal in pra group was significantly higher compared to cp alone. this could be related to local and systemic factors. the local factor is the plaque which was significantly higher in the pra group and this has influenced ppd in this group. the systemic factor in the pra patients is the defect in the immune system which could result in inflammatorymediated destruction predisposing to periodontitis due to an unbalanced cytokine expression profile (22) clinical attachment level refers to the distance from the cementoenamel junction (cej) to the location of the inserted probe tip. thus, loss of fibers attachment expressed at the clinical level was due to the cumulative effect of destructive pathological processes in periodontal together with the protective and destructive effect of the immunological processes. the present study reported highly significant differences in mean il-17 values among the studied groups at p <0.001 also il-17 in pra group is highly elevated than clinically healthygroup. interleukin-17 plays a role in osteoclastogenesis via activation of rankl, causing bone destruction in inflamed joints the severity of ra increase by increase the serum level of il-17 in cp patient and significant increase of serum level of il-17 than healthy group and that showed in (23). il-17 induces cytokine and chemokine expression and may play a role in skeletal tissue destruction and inflammatory processes. patients with pra have markedly elevated in tumor necrosis factor-α levels compared with subjects of cp alone and healthy group at p <0.001. these findings suggest that anti-tnf-α may influence the destruction processes (as j bagh college dentistry vol. 29(1), march 2017 serum level oral and maxillofacial surgery and periodontics 109 reflected by the greater ppd and cal) these observations suggest that periodontal inflammation may be related to high levels of systemic and local tnf-α in patient with ra(24). tnf-α plays a central role in the host inflammatory reaction, which is related to the breakdown of alveolar bone as well as loss of connective tissue attachment that related to highly significant association between serum level of tnf-α and number of teeth lost in pra group and cp group (24). consequently, in chronic periodontal infection, bacteria and/or their components disseminate from the inflamed areas into the circulation to challenge the immune system, the circulating and resident immune cells of the body indicate that peripheral blood monocytes challenged by bacterial lps produce inflammatory mediators like il-1β and tnfα (25). references 1. destefano f, anda r.f, kahn h.s, williamson d.f, russell cm. dental disease and risk of coronary heart disease and mortality. br med j 1993; 306:688-691. 2. sainir,marawarpp,shete s, et al. periodontitis a true infection. j globalinfectdis.2009; 2:149-50. 3. weyand cm. new insights into the pathogenesis of rheumatoid arthritis.rheumatology 2000;39(1):3-8. 4. mercado, fb; marshall,ri; klestov, ac; et al. relationship between rheumatoid arthritis and periodontitis. j periodontol. 2001; 72(6):779-87. 5. eduardo de paula, carlos rossa, keith lough kirkwood,mirianaparecida: periodontal condition in patients with rheumatoid arthritis. (braz oral res 2008; 22(1):72-7. 6. cochran, d l. inflammation and bone loss in periodontal disease. j. periodontol. 2008;79: 15691576 7. preshaw pm, taylor jj. how has research into cytokine interactions and their role in driving immune responses impacted our understanding of periodontitis? j clin periodontol.2011; 38: 60–84. 8. orita s, koshi t, mitsuka t, et al. association between proinflammatory cytokines in the synovial fluid and radiographic grading and pain-related scores in 47 consecutive patients with osteoarthritis of the knee. bmc musculoskelet disord.2011; 12: 144. 9. silva n, dutzan n, hernandez m, dezerega a, rivera o, aguillon jc, aravena o, lastres p, pozo p, vernal r, gamonal j. characterization of progressive periodontal lesions in chronic periodontitis patients: levels of chemokines, cytokines, matrix metalloproteinase-13, periodontal pathogens and inflammatory cells. j clinperiodontol 2008; 35: 206– 214. 10. arnett fc, edworthy sm, bloch da, mcshane dj,fries jf, cooper ns. the american rheumatism association 1987 revised criteria for theclassification of rheumatoid arthritis. arthritis rheum 1988; 31(3): 315 24. 11. lang np, bartold pm, cullinam. internationalclassification workshop: chronic periodontitis.annals of periodontology 1999; 4: 53. 12. silness j, löe h. periodontal disease in pregnancy ιι.actaodontolscand 1964; 24: 747-59. 13. löe h. the gingival index, the plaque index and theretention index system. j periodontol 1967;38: 610– 6. 14. slots j: casual or causal relationship between periodontal infection and non-oral disease? j dent res 1998; 77:1764-1765. 15. petty r.e, southwood t.r, manners p, baum j, glass dn, goldenberg j, et al. international league of associations for rheumatology classification of juvenile idiopathic arthritis: second revision, edmonton, 2001. j rheumatol 2004; 31:390-392. 16. smolik i, robinson d, el-gabalawy h.s. periodontitis and rheumatoid arthritis: epidemiologic, clinical, and immunologic associations.compendcontineduc dent 2009;30:188-190. 17. mercado f, marshall r.i, klestov a.c, bartold p.m: is there a relationship between rheumatoid arthritis and periodontal disease? j clinperiodontol. 2000;27(4):267-72. 18. mercado f.b, marshall r.i, klestov a.c, bartold pm: relationship between rheumatoid arthritis and periodontitis. j periodontol 2001;72:779-787 . 19. feldmann m, brennan f. and maini r: role of cytokines in rheumatoid arthritis. annual review of immunology 1996; 14, 397–440. 20. kässer u.r, gleissner c, dehne f, michel a, bolten ww. risk for periodontal disease in patients with longstandingm rheumatoid arthritis. arthritis rheum 1997; dec;40(12):2248-51 21. wegner n, wait r, sroka a, eick s, nguyen k. a, lundberg k, kinloch a. and venables p. j: peptidylarginine deiminase from porphyromonasgingivaliscitrullinates human fibrinogen and alpha-enolase: implications for autoimmunity in rheumatoid arthritis. arthritis and rheumatism (0202.) 22. bartold p.m, marshall r.i, haynes d.r. periodontitis and rheumatoid arthritis: a review. j periodontol 2005; 76:2066-2074. 23. gümüş p, buduneli e, bıyıkoğlu b, aksu k, saraç f, nile c et al. gingival crevicular fluid, serum levels of receptor activator of nuclear factor-kappa b ligand, osteoprotegerin, interleukin-17 in rheumatoid arthritis and osteoporosis patients with periodontal disease. journal of periodontology. 2013;1-13. 24. kobayashi t, yoshie h. host responses in the link between periodontitis and rheumatoid arthritis. current oral health reports. 2014; 2(1):1-8. 25. zahraa k, batool, h. study the role of proinflammatory and antiinflammatory cytokines in iraqi chronic periodontitis patients [internet]. repository.uobaghdad.edu.iq. 2012 [cited 7 may 2014]. 26. who expert consultation. appropriate body-mass index for asian populations and its implications for policy and intervention strategies. the lancet, 2004; 157-163. j bagh college dentistry vol. 29(1), march 2017 serum level oral and maxillofacial surgery and periodontics 110 الخالصة ى وجود امراض اللثة والروماتيزم الرثوي امراض شائعة في المجتمع وهي تتميز بتحطيم االنسجه بسبب االلتهاب المزمن ,الدراسات الحديثة تشير الالخلفية : صفات مرضيه مشتركه بين المرضين. المزمن لتحديد حالة اللثة الصحية لدى مرضى التهاب اللثة المزمن والمصابين بالروماتيزم الرثوي ومقارنتهم بالمرضى المصابين بالتهاب اللثة اهداف الدراسة : و تي ان اف الفا( في كال المجموعيتن ومقارنتهم مع المجموعه الغير المصابه 01ر لوكين وليس لديهم روماتيزم رثوي وايضا تحديد مستوى السيرم لكل من )انت عمق جيوب بأي من االمراض وربط عالقه بين الدالئل المناعيه مع دالئل التهاب اللثه السريري )مؤشر الصفيحة الجرثومية ,مؤشر التهاب اللثة,مؤشر سنان المفقود ( اللثة,مؤشرفقدان االنسجة الرابطة وعدد اال ( المعنين في هذه الدراسه ولقد تم تقسيمهم الي ثالث مجاميع .مجموعة 54-32اثنى وذكر يتراوح اعمارهم بين )تم اخذ عينات ثمانين شخص من المواد والطرق: شخص مصابين بألتهاب اللثة المزمن المجموعه الثالثه 32شخص. المجموعه الثانيه تتألف من 32م الرثوي تتألف من التهاب اللثة المزمن والمصابين بالروماتيز ياس في) بي تتألف من عشرين شخص والتي تعتبر المجموعه الغير مصابه بأي مرض . كل االشخاص يمتلكون معدل وزن وطول طبيعيان استنادا الى احكام الق ( ايضا لقد تم قياس مؤشر) الصفيحة الجرثومية,مؤشر التهاب اللثة,مؤشرعمق جيوب اللثة,مؤشرفقدان االنسجة الرابطة وعدد 04-4..0ه )ام اي( الذي قيمت يرم لكل من مستوى الساالسنان المفقوده( لكل المجاميع على االسطح االربعه لكل االسنان الموجود , عينات الدم التي جمعت من كل االفراد تم فحصها لمعرفة وتي ان اف الفا( بواسطه االنزيم الرابط بالمناعه. . 01 -)انتر لوكين ي االسنان هذه الدراسة اظهرت المرضى المصابون بالتهاب اللثة المزمن والمصابين بالروماتيزم الرثوي لديهم ميل اكبر لوجود الصفيحة الجرثومية ف النتائج: د مقارنتآ مع المصابين بالتهاب ومعدل اعلى اللتهاب اللثة,زياد كبيره في عمق جيوب اللثة وزياد كبيره في فقدان االنسجة الرابطة.وعدد عالي من االسنان المفقو اللثة المزمن فقط والمجموعه الغير مصابه. وتي ان اف الفا ( كذلك تكشف ان معدالت مستوى السيرم لل 01-ايضا هناك زياد واضحه وفرق في التركيز لكل المجاميع في مستوى السيرم) انترلوكين ( من مجموعه 16.6± 921.6مجموعه المرضى المصابون بالتهاب اللثة المزمن مع المصابين بالروماتيزم الرثوي ) ( احصائيا عاليه في 01-)انترلوكين (. وهذا يشابه مستوى السيرم لل )تي ان اف الفا( في بقية المجاميع 0.1± 04.6( والمجموعه الغير المصابه )4.6± 500.5المصابين بالتهاب اللثه المزمن ) ( و )تي 01-( . وبخصوص الترابط, الدراسه الحاليه تظهر ترابط قوي ايجابي بين مستويات السيرم لل )انترلوكين ±5.6 4.3. ±409 306.5 ±50.0 520.0) ( في مجموعه د ان اف الفا (مع )مؤشر الصفيحة الجرثومية ,مؤشر التهاب اللثة,مؤشر عمق جيوب اللثة,مؤشرفقدان االنسجة الرابطة وعدد االسنان المفقو المصابون بالتهاب اللثة المزمن مع المصابين بالروماتيزم الرثوي . ن اف الفا ( في مجموعة المرضى المصابون بالتهاب اللثة المزمن مع و تي ا 01-كذلك هذه الدراسه تكشف ترابط واضح بين الدالئل المناعيه االثنين ) انترلوكين المصابين بالروماتيزم الرثوي وفي مجموعة التهاب اللثة المزمن. . رم لل ان النتائج تشير الى ارتفاع معدل امراض اللثة لدى المرضى المصابين بالروماتيزم الرثوي والتي ترتبط ايجابيا مع زياده في مستوى السيالخالصة: ( تلعب دور 01-ان )تي ان اف الفا واالنترلوكين و تي ان اف الفا ( بالتتابع مع ارتفاع عالي في النتائج اللثويه السريره التي قد سجلت والذي يعني 01-)انترلوكين مهم في زياد شد امراض اللثة و كذلك في زياد امراض الرماتيزم الرثوي . . j bagh college dentistry vol. 33(2), june 2021 traumatic dental injuries 10 traumatic dental injuries in relation to quality of life among school children in baghdad /iraq shahad jamal (1), nada jafer mh radhi(2) https://doi.org/10.26477/jbcd.v33i2.2933 abstract background: one of the significant public health problems is the traumatic dental injury to the anterior teeth, it has a great impact on children’s daily. physical and psychological disturbance, pain and other negative impacts, such as tendency to avoid laughing or smiling may be associated with traumatic dental injuries, that may affect the social relationships. to determine the occurrence of traumatic dental injuries in relation to quality of life, this study was established among children of primary schools. material and methods: a cross-sectional study was conducted among private (574) and governmental (1026) primary school children in baghdad city. dental trauma was assessed according to ellis and davey classification in1970 and quality of life concerning a child perceptions questionnaire (cpq) was used which consisted according to jokovic et al.in 2006. statistical analysis was done using ibmspass version (21). results: among the permanent anterior dentitions; the most widespread injured teeth were the maxillary central incisors. the boys were more affected with traumatic teeth than girls, as well as a higher percentage noticed in governmental schools than in private schools. among all quality of life questionnaire, a higher percentage were observed in boys rather than in girls, as well as in governmental schools a higher percentage were listed more than in private schools, all differences were statistically highly significant. conclusion: a higher association was noticed between traumatic anterior teeth and quality of life for children. keywords traumatic dental injuries, quality of life and oral condition. (received: 27/2/2021, accepted: 8/4/2021) introduction traumatic dental injuries to the permanent incisors are remarkably common among children and often result in partial or total loss of dental hard tissues along with the underlying esthetic, physical, social, psychological , functional and therapeutic adverse effects on the individual’s quality of life (1,2). it is accepted that the appearance and the position of the anterior teeth have both psychological and social impacts on children by which the appearance of the face plays an important psychosocial role in human life and relationships (3). maxillary central incisors are the most common injured teeth of the permanent dentitions (4,5). quality of life is the general well-being of individuals and societies, outlining negative and positive features of life. it observes life satisfaction, including everything from oral symptoms, functional limitations, emotional wellbeing, and social well-being, and the environment. (1) assistant lecturer , pedodontics and preventive dentistry department, college of dentistry, university of al-farahidi. (2) assistant prof., pedodontics and preventive dentistry department, college of dentistry, university of baghdad. corresponding email, shahad.j.alfalahi@gmail.com quality of life (qol) measures are not a substitute of measuring outcomes associated with the disease, but are adjunct to them (6). many iraqi studies had been done concerning the trauma to the anterior teeth (7-11) however, this study was conducted in baghdad city to estimate the occurrence of traumatic dental injuries in relation to quality of life in elementary schoolchildren, this study is considered the first one in iraq to search association of quality of life and traumatic dental injuries. the null hypotheses was that there is no relation between traumatic dental injuries and quality of life material and methods this cross-sectional study was carried out in baghdad city among the private ( boys 310 and girls 264) and public (boys 580 and girls 446) primary schools, aged 1112 years old.as the sample size was measured by specific statistical equation. depending on the basic method of oral health surveys of the world health organization the oral examination was conducted under integrated situation (12) dental mirrors and probes were used. traumatic dental injury was assessed according to ellis and davey classification (13). the child perceptions questionnaire (cpq) consisted of 16 questionnaire that measure quality https://doi.org/10.26477/jbcd.v33i2.2933 j bagh college dentistry vol. 33(2), june 2021 traumatic dental injuries 11 of life (qol) (1), a number of close-ended questions contain a self-administrated questioner format. a statistical package for social sciences (spss version 21 for windows) was used for both statistical analysis and data entry. chi-square was used to conduct the association between the dependent variable with independent variables. a level of p-value equal to or less than 0.05 was considered as a significant value. results the total sample in the present study were consist of 1600 schoolchildren from boys and girls, aged 1112 years old. they were 574 from private schools and 1026 from governmental schools (table1). table (2) shows the distribution of schoolchildren with traumatic teeth injuries according to the type of schools and gender. the high percentage of schoolchildren with traumatized teeth was found in governmental schools than private schools. regarding gender, boys were affected by dental trauma more than girls. the mean value of traumatic dental injuries were higher among schoolchildren in private schools than in governmental schools, however, this was statistically not significant as it shown in table(3). table (1): distribution of t he sample by gender and school type. type of schools gender total boys girls no. % no. % no. % private 310 54.01 264 45.99 574 100 public 580 56.53 446 43.47 1026 100 table (2): distribution of children with traumatic dental injuries by gender and school type. traumatic injuries of teeth school type private governmental boys girls total boys girls total no % no % no. % no % no % no. % present 27 4.70 9 1.57 36 6.27 89 8.67 47 4.58 136 13.25 table (3): the mean values and standard error of teeth with traumatic dental injuries among private and public schoolchildren. school type no. mean se t-test p-value private 36 2.25 0.24 -1.39 0.19 governmental 136 1.89 0.10 tables (4a), (4b), (4c) and (4d) illustrate the association of traumatic dental injuries and quality of life by schools type. regarding all the associations of traumatic dental injuries and quality of life, among private schools except for “tdi/ trouble in sleeping, tdi/ teased or called names and tdi/not wanted to speak or read loud in class” were statically significant (p<0.05). while concerning all the association of traumatic dental injuries and quality of life in governmental schools they were statistically highly significant (p<0.01). in table (4a), the association of traumatic dental injuries and oral symptoms, it was found that the highest percentage of association in private schools was recorded in bad breath. the same picture was observed in governmental schools, while in table (4b), the association between traumatic dental injuries and functional limitation showed the highest percentage of association was recorded in difficulty in (eating/drinking) hot/cold things in both schools type. table (4c) shows the association of traumatic dental injuries and emotional wellbeing, the highest percentage of association in private schools was observed in concerned what people think about your teeth/mouth, while in j bagh college dentistry vol. 33(2), june 2021 traumatic dental injuries 12 governmental schools it was observed in felt irritable/frustrated). regarding the association of traumatic dental injuries and social well-being the highest percentage of association recorded in avoided smiling/laughing in both schools type, ( table 4d ). table (4a): the association of traumatic dental injuries and quality of life regarding oral symptom by school types. variables severity trauma school private governmental n. % p[hs] n. % p[hs] pain in teeth/mouth 0 22 61.11 0.000 53 38.97 0.000 1 6 16.67 23 16.91 2 7 19.44 22 16.18 3 0 0.00 27 19.85 4 1 2.78 11 8.09 bad breath 0 20 55.56 0.000 48 35.29 0.000 1 10 27.78 9 6.62 2 2 5.56 31 22.79 3 3 8.33 30 22.06 4 1 2.78 18 13.24 mouth sore 0 30 83.33 0.034 73 53.68 0.000 1 3 8.33 29 21.32 2 3 8.33 23 16.91 3 0 0.00 11 8.09 food catching between teeth 0 25 69.44 0.000 49 36.03 0.000 1 5 13.89 17 12.50 2 4 11.11 28 20.59 3 2 5.56 34 25.00 4 0 0.00 8 5.88 table (4b): the association of traumatic dental injuries and quality of life regarding functional limitation by school types. variables severity trauma school private governmental n. % p[hs] n. % p[hs] difficulty in (eating/drinking) hot/cold things 0 19 52.78 0.000 59 43.38 0.000 1 4 11.11 10 7.35 2 7 19.44 27 19.85 3 5 13.89 30 22.06 4 1 2.78 10 7.35 difficulty in eating firm food 0 22 61.11 0.000 70 51.47 0.000 1 3 8.33 15 11.03 2 8 22.22 27 19.85 3 2 5.56 18 13.24 4 1 2.78 6 4.41 difficulty in saying words 0 28 77.78 0.000 94 69.12 0.000 1 6 16.67 19 13.97 2 1 2.78 16 11.76 3 1 2.78 6 4.41 4 0 0.00 1 0.74 trouble in sleeping 0 26 72.22 0.126 70 51.47 0.000 1 2 5.56 2 1.47 2 1 2.78 5 3.68 3 3 8.33 20 14.71 j bagh college dentistry vol. 33(2), june 2021 traumatic dental injuries 13 table (4c): the association of traumatic dental injuries and quality of life regarding emotional wellbeing by school types. variables severity trauma school private governmental n. % p[hs] n. % p[hs] upset 0 26 72.22 0.021 56 41.18 0.000 1 5 13.89 25 18.38 2 5 13.89 32 23.53 3 0 0.00 16 11.76 4 0 0.00 7 5.15 felt irritable/frustrated 0 23 63.89 0.000 51 37.50 0.000 1 4 11.11 11 8.09 2 8 22.22 39 28.68 3 1 2.78 23 16.91 4 0 0.00 12 8.82 felt shy 0 25 69.44 0.000 101 74.26 0.000 1 7 19.44 11 8.09 2 3 8.33 15 11.03 3 1 2.78 7 5.15 4 0 0.00 2 1.47 concerned what people think about your teeth/mouth 0 20 55.56 0.000 58 42.65 0.000 1 10 27.78 31 22.79 2 5 13.89 31 22.79 3 1 2.78 16 11.76 table (4d): the association of traumatic dental injuries and quality of life regarding social wellbeing by school types. variables severity trauma school private governmental n. % p[hs] n. % p[hs] teased/called names 0 31 86.11 0.126 83 61.03 0.000 1 3 8.33 4 2.94 2 1 2.78 21 15.44 3 1 2.78 24 17.65 4 0 0.00 4 2.94 avoided smiling/laughing 0 18 50.00 0.000 53 38.97 0.000 1 5 13.89 30 22.06 2 9 25.00 38 27.94 3 4 11.11 15 11.03 not wanted to speak/read loud in class 0 35 97.22 1.000 104 76.47 0.000 1 1 2.78 12 8.82 2 0 0.00 13 9.56 3 0 0.00 7 5.15 argued with children/family 0 23 63.89 0.000 66 48.53 0.000 1 4 11.11 11 8.09 2 1 2.78 13 9.56 3 6 16.67 24 17.65 4 2 5.56 22 16.18 j bagh college dentistry vol. 33(2), june 2021 traumatic dental injuries 14 discussion a problems in the oral health were recognized as important factors in causing a negative impact on daily performance and qol (2); the problem in oral the oral health were more in private than in governmental schools. perhaps trauma is one of the dental disturbances that cause much of distress and psychological adverse effect to both children and their parents. moreover, the anterior teeth are more susceptible to traumatic dental injuries due to their morphology and location (14). the prevalence of traumatic dental injuries to the permanent anterior teeth in both private and governmental children of primary schools; permanent anterior teeth where from (6.27% 13.25%), while other studies reported it (1.36% 29.6%) (10; 15-18). increase the risk for accidents in schoolchildren may be due to frequently engaged in intense/competitive activities which will increase the risk for accidents (19 ,20).the negative impact of traumatic dental injuries on the children’s life includes difficulty in eating, loss appetite, cannot sleep well, losing weight, irritability in their behavior and low selfconfidence and decrease in school performance (21). this study showed a significant impact of tdi on qol among primary schoolchildren. reduced smiling, laughing, and socializing with others may due to the inconclusive appearance of untreated fractured incisors. this is in agreement with results that suggested that children with fractured teeth were major concerns for esthetics rather than function (22). the present study revealed that there was a high association between traumatic dental injuries and the functional and emotional well-being. santos et al.(20) also supported these results related to “difficulty in eating” “felt shy” and “caring about what others were thinking of appearance.” opposite picture was observed in other study (21-24). good oral health is essential to improve individual overall health and well being as oral health also affects quality of life in children. the present study recommended an educational program for children regarding information about the importance of dental trauma, ways of how to prevent dental trauma, the advantages of immediate attendance and conservation of avulsed and fractured teeth. this would not only reduce the overall rate of dental injuries, but also minimize the sequelae of traumatic injuries, and it is also recommended that increase knowledge and improvement of quality of life among schoolchildren will enhance their oral health condition. conflicts of interest the authors has nothing to disclose. references 1. jokovic a, locker d, stephens m, kenny d, tompson b, guyatt g. measuring parental perceptions of child oral-health-related quality of life. j public health dent. 2006;63:67–72. 2. abanto j, carvalho ts, mendes fm, wanderley mt, bo¨necker m, raggio dp. impact of oral diseases anddisorders on oral health-related quality of life of preschool children. community dentistry oral epidemiology 2011; 39: 105–114. 3. david j, strøm ana, wang nj. factors associated with traumatic dental injuries among 12-year-old schoolchildren in south india. dental traumatology 2009; 25:500–505. 4. al-obaidi w, al-mashadani a. traumatic injuries among 5-30 years in sheha village. iraqi dent j. 2002; 29:299-304. 5. hassan f. farhan. traumatized anterior teeth among 13-15 year old intermediate school students in hilla city, babylon government/ iraq. master thesis submitted to college of dentistry, university of baghdad, 2008. 6. barcaccia, barbara (4 september 2013). "quality of life: everyone wants it, but what is it?". forbes/ education. retrieved 10 may 2016. 7. al-hayali a. traumatized anterior teeth among 4-15 years old in the central region of iraq. master thesis submitted to the college of dentistry, university of baghdad; 1998. 8. al-obaidi wa, al-geburi ik. pattern of traumatic dentalinjuries in a sample formal-buetha village, baghdad. iraqi dentj 2002;30:207–14. 9. al-kassab a. evaluation of primary school student with traumatized anterior permanent incisors in relation to different variables in mosul city. master thesis submitted to the college of dentistry, university of baghdad; 2005. 10. noori a. prevalence and pattern of traumatic dental injuries among primary school in sulaimani city. master thesis submitted to college of dentistry, university of sulaimani; 2007. 11. azhar ammash hussien. traumatic dental injuries among 6 – 13 – year old school children in tikrit city. mdj 13 (1) 2016. 12. world health organization. (1997). oral health surveys : basic methods, 4th ed. world health organization. 13. shobha tandon. text book of pedodontics. 2nd edition, india: paras,2009. 14. soriano ep, caldas jr af, carvalho mvd, amorimfilho ha. prevalence and risk factors related to traumatic dental injuries in brazilian j bagh college dentistry vol. 33(2), june 2021 traumatic dental injuries 15 schoolchildren. dental traumatology 2007; 23:232– 240. 15. al-azawi l. oral health status and treatment needs among iraq 5 years old kindergarten children and 15 years old student (a national survey). ph.d. thesis submitted to the college of dentistry, university of baghdad, 2000. 16. baghdady vs et al. traumatized anterior teeth as related to their causes and place. community dent oral epidemiol. 1981,9 : 91. 17. el-samarrai s. oral health status and treatment need among preschool children in baghdad. msc thesis. baghdad: college of dentistry, university of baghdad; 1989. 18. hassan f. farhan, ahlam t. mohammed. traumatized anterior teeth among 13-15 years old intermediate school students in hilla city, babylon governorate iraq. 2014, idj,36 (1). 19. traebert j,lacerda jtd,page laf,thomson wm,bortoluzzi mc. impact of traumatic dental injuries on the quality of life of schoolchildren. dental traumatology 2012; 28: 423–428. 20. santos a, faria d, spitz b, volpe a. impact of traumatic dental injury on the quality-of-life of children and adolescents: a case-control study. acta odontol scand. 2013. 71:1123–8. 21. bendo cb, paiva sm, torres cs, oliveira ac, goursand d, pordeus ia.. association between treated / untreated traumatic dental injuries and impact on quality of life of brazilian schoolchildren. health qual life outcomes. 2010, 8:114. 22. traebert j,lacerda jtd,page laf,thomson wm,bortoluzzi mc. impact of traumatic dental injuries on the quality of life of schoolchildren. dental traumatology 2012; 28: 423–428. 23. irene julie higginson, alison j carr. easuring quality of life: using quality of life measures in the clinical setting, 322(7297):1297-300 · june 2001. 24. abanto j, carvalho ts, mendes fm, wanderley mt, bo¨necker m, raggio dp. impact of oral diseases anddisorders on oral health-related quality of life of preschool children. community dentistry oral epidemiology 2011; 39: 105–114. المستخلص حدة من مشاكل الصحة العامة الكبيرة هي إصابة األسنان األمامية لألسنان ، ولها تأثير كبير على حياة األطفال اليومية. االضطرابات واالخلفية: االبتسام قد تترافق مع إصابات األسنان الرضية التي قد تؤثر الجسدية والنفسية واأللم واآلثار السلبية األخرى ، مثل الميل إلى تجنب الضحك أو بين أطفال المد هذه الدراسة إنشاء تم ، الحياة بنوعية يتعلق فيما األسنان الرضية إصابات حدوث مدى لتحديد االجتماعية. ارس على العالقات . االبتدائية ( من تالميذ المدارس االبتدائية في مدينة بغداد. 1026قطاع الخاص والحكومي )( تلميذ من ال574تم إجراء دراسة مقطعية على )المادة والطرق: ( cpqوتم استخدام نوعية الحياة المتعلقة باستبيان تصورات الطفل ) 1970في عام daveyو ellisتم تقييم إصابات األسنان وفقًا لتصنيف .ibmspass( 21اإلحصائي باستخدام نسخة ) . تم إجراء التحليل jokovic et al. 2006والذي يتكون وفقًا لـ األسنان صاباتمن خالل األسنان األمامية الدائمة. كانت األسنان األكثر إصابة هي القواطع المركزية العلوية. كان األوالد أكثر تأثراً باالنتائج: جودة الحياة استبيانات جميع بين الخاصة. من في المدارس منها لوحظت في المدارس الحكومية أعلى أن النسبة التي كما ، بالفتيات ، مقارنة نت جميع لوحظت نسبة أعلى في األوالد وليس لدى الفتيات ، وكذلك في المدارس الحكومية تم تسجيل نسبة أعلى منها في المدارس الخاصة ، وكا الفروق ذات داللة إحصائية عالية. . لوحظ ارتباط أعلى بين األسنان األمامية المتعرضة للصدمة ونوعية الحياة لألطفالالخالصة: articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ basima f.doc j bagh college dentistry vol. 27(3), september 2015 effect of addition restorative dentistry 15 effect of addition zro2-al2o3 nanoparticles mixture on some properties and denture base adaptation of heat cured acrylic resin denture base material ali ma aljafery, b.d.s. (1) basima mah, b.d.s., m.sc., ph.d. (2) abstract background: the pmma polymer denture base materials are low mechanical properties, adaptation of the denture base to underlying tissue is important for retention and stability of denture. the aim of the study was toevaluate the effect of mixturezro2-al2o3 nanoparticles on impact strength, transverse strength, hardness, roughness, denture base adaptation of heat cured acrylic resin denture base material. materials and methods: one hundred (100) specimens were prepared, the specimens were divided into five groups (20 specimens to each) according to the test type, each group was subdivided in to two subgroups (control and experimental) each subgroup consist of 10 specimens, the experimental group included mixture of 2% (zro2al2o3ratio2:1) by weight. theimpact strength was measured by charpy's impact testing machine, the transverse strength was measured by instron testing machine while the hardness was measured byshore d durometer and roughness was measured by profilometer. denture base adaptation was measured by digital microscope and evaluated by computerized tomography (ct). results: highly significant increaseofimpact and transverse strength, non-significant increase ofhardness, significant increase ofroughness andreduction of denture base adaptation (measured at 3 point a, b and c) occurred in experimental groupwhen compared to control group. ct evaluation, gap between the denture base and master cast (control and experimental groups) increased from the anterior to posterior side of palate and from the alveolar ridge to the mid palatal line. conclusion: the polymer nanocomposites had mechanical properties higher than neat pmma at same time less denture base adaptation. keywords: acrylic denture base, nano fillers, mechanical properties, denture base adaptation. (j bagh coll dentistry 2015; 27(3):15-21). introduction acrylic resin polymethyl methacrylate (pmma) is the most extensively used material in fabrication of dentures. although it is very popular, this material is still insufficient in fulfilling the ideal mechanical requirements of such appliances (1). clinicians still encounter fracture of this material due to low resistance to impact, flexural, or fatigue stresses (2). in order to prevent fracture of the dentures, the thickness of acrylic resin in susceptible regions, such as the palatal midline, and the mandibular lingual and labial frenal attachments has been increased(3). in addition, improvement on mechanical properties of denture base materials were tried to be achieved either by adding a polyfunctional cross-linking agent such as polyethylene glycol dimethacrylate (4) or by incorporating a rubber phase (5), metal oxides, metal wire (6,7) or fiber (8). the reinforcement of polymers used in dentistry with metal-composite systems has been a prime interest. addition various amounts of powdered cu, ag and al into the pmma resin and reported increased compressive strength but decreased tensile strength (9). (1)m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2)assistant professor. department of prosthodontics, college of dentistry, university of baghdad. evaluation the changes in the mechanical properties of pmma, polyethyl methacrylate (pema) and poly isobutyl methacrylate (pima) resin matrices by reinforcingwith oxides of al, mg, zr and pulverized e-glass particles (10). they suggested that 2% admixtures by volume in pmma resin matrix resulted in better mechanical properties. much attention has been directed toward the incorporation inorganic nanoparticles in to pmma to improve its properties. the properties of polymer nanocomposites depend on the type of incorporating nanoparticles, their size and shape, as well as the concentration and interaction with the polymer matrix (11). nanoparticles were undergone surface treatment with silane coupling agent and embedded in to pmma (12). alumina nanoparticles were treated with trimethoxysilylpropylmethacrylate (tmspm) to get pmma/alumina nano composite with improved properties over pure pmma (13). also, using modified zro2 with trimethoxysilylpropylmethacrylate to get pmma/ zro2 nano composite to improve properties of pmma (14). furthermore, studying an experimental investigation of mixture ha/al2o3 nanoparticles on mechanical properties of restoration materials (15). also, evaluation of influence of mixture of zro2-tio2 on mechanical and physical properties j bagh college dentistry vol. 27(3), september 2015 effect of addition restorative dentistry 16 of heat-cured polymethyl methacrylate denture base resins (16).though the incorporation of fillers like rubber and fibers to heat-cured poly methyl methacrylate resin improves the impact strength and fatigue resistance, it may affect some of the properties of heat-cured poly methyl methacrylate resin such as fitness accuracy (denture adaptation), dimensional stability and the effect of water sorption (17). various investigators have compared the dimensional changes between different denture base materials (17,18), palatal vault configurations (19), methods of packing (18), modes of polymerization (20) and curing cycles (21). this study was conducted to use inorganic mixture of zro2-al2o3 nano fillers that were added to heat cure pmma and test the effect of this addition on the some mechanical properties and denture base adaptation of heat cured acrylic denture base material. materials and methods some of the materials used in this study are summarized in table (1). table 1: list of the materials that were used material zro2 nanofiller al2o3 nanofiller trimethoxysilylpropyl methacrylate(tmspm) heat-curing acrylic resin manufacturer hwnano china ns6130 01-123 germany 2530-85-8 germany vertex netherlands test specimens preparation two different plastic patterns were constructed according to the required test. the pattern that was constructed for impact strength a bar shaped specimen (80mm x 10mm x 4mm) length, width, thickness respectively (22). for transverse strength test: a bar shaped specimen was constructed (65mm x 10mm x 2.5mm) length, width, thickness respectively (23) (figure 1). same specimen measurement was used to prepare hardness test and roughness test. for denture base adaptation test: prepare acrylic resin denture bases with their corresponding master casts byconventional denture flasking technique using a biostar sheet as record base (2mm thickness) without teeth. figure 1: plastic patterns; a for transverse strength, b for impact strength surface modification of nanofillers (zro2, al2o3) the introduction of reactive groups to the fillers surface was achieved by reaction of 3trimethoxy silylpropyl methacrylate (tmspm) with zirconium oxide and aluminum oxide nano fillersthrough salinization procedure (24). for zro2, tmspm was used in 5% wt. of nanofiller, toluene was used as a solvent to zro2 (12,14,24), while al2o3,tmspm was used in 75% wt. of al2o3, ethanol was used as a solvent toal2o3 (13). mould preparation addition of fillers this only for experimental groupincluded mixture of 2% (zro2-al2o3 ratio 2:1) by weight, electronic balance (sartorius, germany)with sensitivity of (0.0001g)was used to weigh then nanofillers powder weight in 2%wt. of the pmma powder weight. the filler was added to the monomer of pmma mixed by the probe sonifier apparatus (danbury, u.s.a.) for 3 minutes (13,14) to disperse the nanoparticles in the monomerand reduce the possibility of particle aggregation. mixing of the acrylic acrylic materialwas mixed and manipulated according to manufacturer's instructions using a conventional water bath denture flasking technique for both groups (control and experimental). for experimental group the suspension of the monomer with nanofiller was immediately mixed with acrylic powder. mechanical and denture base adaptation tests 1-impact strength test. aall theprepared specimens (20 specimens, 10 for each control and experimental groups) stored in distilled water inside incubator at 37°c for 48 hours before testing (23). btesting procedure: the impact strength test was carried out following the procedure recommended by the iso 179 usingimpact testing device (tmi, testing machine inc. amity ville, new york, usa) (22) (figure 2).the specimen was supported horizontally at each end and strucked by free swinging pendulum of 2 joules. a b j bagh college dentistry vol. 27(3), september 2015 effect of addition restorative dentistry 17 the scale readings give the impact energy in joules. the charpy impact strength of un-notched specimen was calculated in kilo-joules per square meter using the following formula: impact strength (kj/m2) 103 where e: the impact energy in joules, b: is the width of the specimens in millimeters, d: is the depth of the specimens in millimeters. 2-transverse strength test. a. all the prepared specimens (20 specimens, 10 for each control and experimental groups) stored in distilled water inside incubator at 37°c for 48 hours before being tested (23). b. testing procedure: the test was performed using instron universal testing machine (wdw200 e, uk) (figure 3), each specimen was positioned on the bending fixture which consist of two parallel supports (50 mm apart). the load was applied by a rod placed centrally between the supports with across head speed of 1mm/min applied making deflection until fracture occurs. the transverse strength was calculated using the following formula: transverse strength (n/mm2) where p: is the peak load, l: is the span length, b: is the sample width, d: is the sample thickness (25). figure 2: impact strength testing device figure 3: instron testing device 3measuring hardness property aall the prepared specimens (20 specimens, 10 for each control and experimental groups) stored in distilled water inside incubator at 37°c for 48 hours before being tested (23). btesting procedure: test was performed using durometer hardness tester (shore d hardness, th210, italy)which is suitable for acrylic material (23). the instrument consists of a blunt pointed indenter (0.8 mm in diameter) that present in a cylinder (1.6mm in diameter) .the indenter was attached to a digital scale that is graduated from 0 to 100 unit. the usual method was to press down firmlyand quickly on the indenter, a measurements were taken directly from the digital scale reading. five measurementswere recorded on different areas of each specimen and an average of these five readings was recorded. 4-measuring surface roughness. aall the prepared specimens (20 specimens, 10 for each control and experimental groups) stored in distilled water inside incubator at 37°c for 48 hours before being tested (23). btesting procedure: the profilometer device surface roughness tester (th 210, china) was used to test the micro geometryof the surface for experimental and control group.the device has surface analyzer (sharp stylus made from diamond) to trace the profile of the surface irregularities. it moves for maximum distance of 11 mm. the profilometer records by its scale all the peaks and recesses which characterized the surface of the specimen under testing. the analyzer pass along the specimen surface for 11 mm distance. three locations were selected in every specimen making 3 readings then the mean of these readings were recorded as a surface roughness value for each specimen. 5denture base adaptation testing amicroscopic measurement:the castdenture base sets (20 specimens, 10 for each control and experimental groups)was sectionedto a horizontal line 5 mm away from theposterior end of the cast using a cutting saw device under water cooling (26,27). three points were marked on the cast on transverse line at the posterior border of the cast specimens (deepest point of the left vestibule, left ridge crest andmidline point which is marked according to the line bisecting the incisive papilla and extending posterior on the cast) as (a, b and c) respectively (figure 4) (26). figure 4: denture base with its castshow position of 3 points: (1) point a, (2) point b and (3) point c 2 1 3 j bagh college dentistry vol. 27(3), september 2015 effect of addition restorative dentistry 18 the gap between the cast and the denture base margin at these 3 points was measured with the use of digital microscope (dinolite, taiwan) of magnification 200x capability and accuracy of 0.001 mm. two measurements were made, first one made immediately after deflasking and sectioning for all the samples. second measurement was done after incubation in distilled water at 37°c for 14 daysfor all the samples (27), then each denture base was seated on its corresponding cast and measurement of the gab was done while a weight of 1kg was placed over the denture base to ensure a proper seating of the denture base over the cast (26). bto observe the overall gap formation of the denture base, all denture bases placed on theirrespective master cast for each group was scanned by computerized tomography(light speed, philips, netherland), (figure 5). the frontally-sectioned images of the denture-cast set and sagittal images obtained at the palatal midline were taken from the ct data (27). a b figure 5: acomputerized tomography device, bthe casts with their corresponding denture bases under scanning results mean values, standard deviation, t-test, pvalue and significances of mechanical properties presented in table (2). table 2: descriptive and statistics of mechanical properties property tested groups n mean s.d. t-test p. value sig. impact strength (kj/m2) control group 10 7.94 0.25 -16.02 0.000 hs experimental group 10 9.63 0.22 transverse strength (n/mm2) control group 10 88.50 0.77 -11.85 0.000 hs experimental group 10 93.48 1.08 surface hardness control group 10 84.64 1.12 -1.316 0.205 ns experimental group 10 85.35 1.27 surface roughness (μm) control group 10 1.29 0.08 -2.309 0.033 s experimental group 10 1.37 0.07 mean values, standard deviation, t-test, p-value and significances of the gap at three selected points (a, b and c) to measure denture base adaptation presented in table (3). table 2: descriptive and statistics of the gap(mm)at three point point time tested groups n mean s.d. t-test p-value sig. point a immediately after deflsking control group 10 0.122 0.018 -2.160 0.045 s experimental group 10 0.160 0.054 after incubation 14 day control group 10 0.143 0.038 -2.266 0.036 s experimental group 10 0.195 0.063 point b immediately after deflsking control group 10 0.065 0.016 -2.61 0.018 s experimental group 10 0.081 0.013 after incubation 14 day control group 10 0.088 0.035 -1.64 0.111 ns experimental group 10 0.113 0.036 point c immediately after deflsking control group 10 0.244 0.040 -0.711 0.486 ns experimental group 10 0.257 0.033 after incubation 14 day control group 10 0.284 0.053 -0.524 0.607 ns experimental group 10 0.301 0.087 j bagh college dentistry vol. 27(3), september 2015 effect of addition restorative dentistry 19 evaluation of denture base adaptation made by ct images (figure 6) was at the mid sagittal line of denture bases on the respective master cast for all tested specimen (control and experimental groups), gap formation between the tissue surface of the denture base and master cast increased from the anterior to posterior side of palate and also from the alveolar ridge to the mid palatal line. however, the gap distance or volume could not be measured from the ct images due to the low resolution. a b figure 6: computerized tomography images for denture-cast sets: a. control group, b. experimental group discussion the present study was conducted to evaluate and compare the effect of addition (zro2:al2o3nano-fillers mixture) to pmma on some mechanical properties and denture base adaptation of heat cured acrylic denture base.the introduction of nanofillers into pmma produced highly significant increase in the value of impact strengthwhen compared with control group. the increase in the impact strength could be due to thehigh interfacial shear strength between nanofiller and matrix resulted from the formation of cross-links or supra molecular bonding which cover or shield the nano fillers which in turn prevent propagation of cracks. also the crack propagation may be changed by good bonding between nanofiller and resin matrixresulted from interaction between the functional groups introduced by salinization process (28). the small size and high surface area and relatively low concentration may helped in a good distribution of these fillers that may cause a restricted motion of macromolecule chains and enhance mechanical properties (29), that means the pmma nanocomposite has mechanical stability more than neat pmma. also, the transverse strength test result showed highly significant increase with nanocomposite when compared with control group.this increase in transverse strength may be explained on the basis of transformation toughening, when sufficient stress develops and crack begins to propagate, a transformation of zro2 and al2o3 which depletes the energy of crack propagation, also, in this process expansion of zro2 and al2o3 crystals occurs and places the crack under a state of compressive stress and crack propagation is arrested (25). increase in transverse strength also could be due to transfer of stress from more flexible polymer to the higher modulus, more rigid and stiffer filler particles (25). the addition of nanofillers at 2wt.% to pmma led to increase of surface hardness beyond that of pure pmma, statistically was not-significant,this could be due to the relatively low concentration of the nanofillers used in the study, although, this improvement may be attributed to the inherent characteristics of the nanoparticles. nanoparticles possess strong ionic interatomic bonding, giving rise to its desirable material characteristics, that is, hardness and strength. on these bases it may be expected when nanoparticles disperse in a matrix, they increase its hardness and strength (30). the surface roughness of modified pmma with nanofiller was significantly increased when compared with control group.this is may be due to the differencein roughness of nano particles and acrylic denture base matrix and also probably attributed to the difference in micro structural characteristics of the materials and the form of the particles (31). with regard to this study, the significantly increase insurface roughness can be considered uninfluential since microorganism colonization occurs when the roughness more than 0.2µm (32).the gap between denture base and cast was measured at 3 point (a, b, c) in two time to j bagh college dentistry vol. 27(3), september 2015 effect of addition restorative dentistry 20 evaluate denture base adaptation, where it mostly depend on polymerization shrinkage and water sorption of pmma (33,34). so, in first measurement made immediately after deflasking showed a significant increase of gap in experimental groupwhen compared to control groupat point a and b, and nonsignificant increase of gap in experimental group at point c. this increase explained may be due to addition of nanoparticle lead to increase in thermal conductivity of acrylic resin (13,30), and degree of polymerization effected considerably by heat dissipation and thermal conductivity (35), lead to contraction of denture base due to further polymerization shrinkage that occur due to exposure to high temperature with reduction in the spaces between the chain of the polymer this result in agreement with ogawaand and hasegawa (36). in second time after incubation 14 day showed in a significant increase of gap in experimental group when compared to control groupat point a, and non-significant increase of gap in experimental group at point b and c. this result may be due to that the addition of nanoparticles to pmma may decreased in water sorption when compared with unmodified pmma (13,16), so decrease expansion of acrylic denture base which considered antagonist effect to polymerization shrinkage that occur in experimental group more than control group as discussed previously (37). the ct images of denture base-cast sets did show this tendency of gap formation in mediallateral and anterior-posterior areas (figure 6). these findings are also predictable with the results reported by consani et al. (38), who compared the posterior border gap of the denture base-cast sets sectioned transversally at each area of the canine, molar and posterior ends. moreover, the magnitude of the posterior border gap generally increased medially along the palatal vault reaching a maximum at the midline of the palate (39,40). references 1. darbar ur, huggett r, harrison a. denture fracture-a survey. br dent j 1994; 176: 342-5. 2. jagger dc, harrison a, jandt kd. review: the reinforcement of dentures. j oral rehabil 1999; 26:185-94. 3. meng tr jr, latta ma. physical properties of four acrylic denture base resins. j contemp dent pract 2005; 6: 93-100. 4. kanie t, fujii k, arikawa h, inoue k. flexural properties and impact strength of denture base polymer reinforced with woven glass fibers. dental materials 2000; 16: 150–8. 5. knott nj. the durability of acrylic complete denture bases in practice. quintessence int 1989; 20: 341-3. 6. ruffino ar. effect of steel strengtheners on fracture resistance of the acrylic resin complete denture base. j prosthet dent 1985; 54: 75-8. 7. teraoka f, nakagawa m, takahashi j. adaptation of acrylic dentures reinforced with metal wire. j oral rehabil 2001 28; 937-42. 8. goldberg aj, burstone cj. the use of continuous fiber reinforcement in dentistry. dent mater 1992; 8: 197-202. 9. sehajpal sb, sood vk. effect of metal fillers on some physical properties of acrylic resin. j prosthet dent 1989; 61: 746-51. 10. zuccari ag, oshida y, moore bk. reinforcement of acrylic resins for provisional fixed restorations. part i: mechanical properties. biomed mater eng 1997; 7: 327-43. 11. jordan j, jacob kl, tannenbaum r, shart ma, jasiuk i. experimental trends in polymer nan composites-a review. mater sci eng 2005; 393(1) 1-11. 12. shi j, bao y, huang z, weng z. preparation of pmma-nanomater calcium carbonate composites by in-situ emulsion polymerization. j zhejiang university sci 2004; 5(6) 709-13. 13. jasim bs. the effect of silanized alumina nano fillers addition on some physical and mechanical properties of heat cured polymethyl methacrylate denture base material. m.sc. thesis, college of dentistry/university of baghdad, 2013. 14. safi in. evaluation the effect of modified nano filler addition on some properties of the heat cure acrylic risen denture base material. m.sc. thesis, college of dentistry, university of baghdad, 2011. 15. majid s, nabi mk, abbas r. an experimental investigation of ha/al2o3 nanoparticles on mechanical properties of restoration materials. engineering solid mechanics 2014; 2:173-82. 16. asar nv, hamdi a, turan k, ilser t. influence of various metal oxides on mechanical and physical properties of heat-cured polymethylmethacrylate denture base resins. j adv prosthodont 2013; 5: 241-7. 17. becker cm, smith de, nicholls j. the comparisons of denture –base processing technique. ii. dimensional changes due to processing. j prosthet dent 1977; 37: 450-90. 18. anusavice kj. philip's science of dental material.10th ed. philadelphia: w.b, saunders co.; 1996. p. 211, 220, 235, 237-271. 19. craig rg, o'brien wj, powers jm. dental-materials properties and manipulation. 4th ed. st. louis: cv mosby co.; 1990. p. 272-96. 20. anderson gc, schulte jk, arnold tg. dimensional stability of injection and conventional processing of denture base acrylic resin. j prosthet dent 1988; 60(3): 394-8. 21. chen jc, lacefield wr and castleberry dj. effect of denture thickness and curing cycle on the dimensional stability of acrylic resin denture bases. dent mater j 1988; 4: 20-4. 22. iso 179-1 international organization for standardization. determination of charpy impact properties: part 1, 2000. 23. american dental association specification no.12. guide to dental materials and devices. 10th ed. chicago, 1999; p: 32. 24. ayad nm, badawi m, abdou a fatah. effect of reinforcement of high-impact acrylic resin with j bagh college dentistry vol. 27(3), september 2015 effect of addition restorative dentistry 21 zirconia on some physical and mechanical properties. rev clinical dental 2008; 4(3): 145-51. 25. anusavice kj. philips science of dental material. 11th ed. middle east and african ed., ch7, ch22, 2008; p: 143-166,721-756. 26. hussein ya. influence of different ph of saliva and thermal cycling on the adaptation of different denture base materials. m.sc. thesis, college of dentistry/ university of baghdad, 2012. 27. lee c, bok s, bae j, hae-hyoung lee. comparative adaptation accuracy of acrylic denture bases evaluated by two different methods. dent mater j 2010; 29(4): 411-7. 28. sun l, gibson rf, gordaninejad f, suhr j. energy absorption capability of nanocomposites: a review. composites science and technology 2009; 69(14): 2392-409. 29. gupta n, brar bs, woldesenbet e. effect of filler addition on the compressive and impact properties of glass fiber reinforced epoxy. bull mater sci 2001; 24:219-23. 30. ellakwa ae, morsy ma, el-sheikh am.effect of aluminum oxide addition on the flexural strength and thermal diffusivity of heat-polymerized acrylic resin. j prosthodont 2008; 17: 439-44. 31. alnamel ha. the effect of silicon dioxide nano-fillers reinforcement on some properties of heat cure poly methymethacrylate denture base material. m.sc. thesis, college of dentistry, university of baghdad, 2013. 32. quirynen m, marechal m, busscher hj, weerkamp ah, darius pl, steerberghe d. the influence of surface free energy and surfsce roughness on early plaque formation: an in vivo study in man. j clin periodontol 1990; 17:138-44. 33. wolfoardt j, cleaton-jones p, fatti p. the influence of processing variables on dimensional changes of heat cured poly methyl methacrylate. j prosth dent 1986; 55: 518-25. 34. salim s, sadamori s, hamada t. the dimensional accuracy of rectangular acrylic resin specimens cured by three denture base processing methods. j prosthet dent 1992; 67: 879-81. 35. dhuru vb. contemporary dental materials. oxford university uk, 2003. 36. ogawa t, hasegawa a. effect of curing environment on mechanical properties and polymerizing behavior of methylmethacrylate auto polymerizing resin. j oral rehabil 2005; 32: 221-6. 37. andrew j. polymer chemistry properties and application. carlverlag publisher, 2006; ch. 23 p. 33945. 38. consani rl, domitti ss, consani s. effect of a new tension system, used in acrylic resin flasking, on the dimensional stability of denture bases. j prosthet dent 2002; 88: 285-9. 39. laughlin a, david eick j, alan g, leslie y, dorsy j. a comparison of palatal adaptation in acrylic denture bases using conventional and anchored polymerization techniques. j prosthodont 2001; 10(4): 204-11. 40. takamata t, setcos jc, phillips rw, boone me. adaptation of acrylic resin dentures as influenced by the activation mode of polymerization. j am dent assoc 1989; 119: 2716. الخالصة البولیمر ذات خواص میكانیكیة منخفضة، وتكیف قاعدة الطقم إلى األنسجة الكامنة مھم الستبقاء )الراتنجاألكریلك(میثاكریلیتلمادة قاعدة الطقم البولیمثی:خلفیة على قوة الصدمة والقوة وكسید االلمنیوم وأوكسید الزركونیوموكان الھدف من ھذه الدراسة ھو تقییم تأثیر خلیط الحبیبات النانویة أل. قرار قاعدة الطقمواست .لمادة قاعده طقم الراتنجاألكریلك الحراريقاعدة الطقم العرضیة، صالبة و خشونة السطح، وتكیف وفقا لنوع االختبار، ومن ثم تم تقسیم كل مجموعة إلى ) عشرونعینة لكل مجموعة(نة، تم تقسیم ھذه العینات إلى خمسمجموعات أعدت مائةعی: المواد والطرق أوكسیدالزركونیوم (٪ وزنا ل2عینات، وتضمنت المجموعة التجریبیة خلیط من ة كل مجموعة فرعیة تتكون من عشر)السیطرة والتجریبیة(مجموعتینفرعیتینھي ، تم قیاس ) charpy(تم قیاس قوة الصدمة بواسطة آلة اختبار الصدمة). zro2:al2o3 2:1(، وبنسبةمیثاكریلیتلالبولیمثی من مسحوق)اللمنیوموأوكسیدا وتم قیاس خشونة , (shoreddurometer) بواسطة مقیاس بینما تم قیاس صالبة السطح instron)(القوة العرضیة بواسطة آلة اختبار انسترون ). ct(بواسطة المجھر الرقمي وتقییمھا من قبل جھاز التصویر المقطعي المحوسب قاعدة الطقم تم قیاس تكیف . profilometerالسطح من قبل الذي تم قاعدة الطقم صانفیتكیف زیادة كبیرة للغایة في قوة الصدمة والقوة العرضیة، وزیادة غیر كبیرة في الصالبة، وزیادة كبیرة في الخشونة ونق: النتائج أما تقییم جھاز التصویر المقطعي المحوسب ، الفجوة . حصلت في المجموعة التجریبیة مقارنة بالمجموعة السیطرة) cو a ،b(نقاط ھي)3(قیاسھ عند ثالث ومن قمة عظم الفكنب األمامي إلى الخلفي من سقف الحلق یظھر فیھ زیادة من الجا) السیطرة والتجریبیة(بین قاعدة الطقموالقالب الرئیسي لكال المجموعتین . إلى خط منتصف الحنك وفي نفس الوقت نقصان في تكیف الحراري النقي البولیمر الراتنجاألكریلكلدیھا خواص میكانیكیة أعلى من مادة النانو المركبة على أساس البولیمر:االستنتاج . قاعدة الطقم .قاعدة الطقمم االكریلیك ، حشوة النانو، الخواص المیكانیكیة، وتكیف قاعدة طق: الكلمات الرئیسیة 5majed f.docx j bagh college dentistry vol. 28(3), september 2016 evaluation of mechanical restorative dentistry 30 evaluation of mechanical and histological significance of nano hydroxyapatite and nano zirconium oxide coating on the osseointegration of cp ti implants majed mohamed refaat, b.d.s. (1) thekra ismael hamad, b.d.s., m.sc., ph.d. (2) abstract background: dental implant considers a unique treatment option for the replacement of missing dentition. the new trend of implants is looking for materials which accelerate bone formation in bone implant interface and enhance osseointegration to provide immediate loading directly after placement and decrease the time period which is disturbs patients and uncomfortable. the aim of the study was to evaluate the effect of nano zirconium oxide (zro2) and nano hydroxyapatite (hap) mixture coating of screw shaped commercially pure titanium (cpti) implants on bond strength at the bone implant interface with torque removal test and histological analysis in comparison with non coated implants. materials and methods: forty screws were machined from cpti rods using a lathe machine. then 20 screws coated by electrophoretic deposition method by a mixture of nano hydroxyl apatite and nano zirconium oxide, while the other 20 screws remain uncoated. the tibia of 10 adult white new zealand experimental rabbits was chosen as implantation site, each rabbit tibia received 2 screws, one coated and the other uncoated. torque removal test was performed to measure the torque required to remove the screw and histological analysis was performed to observe the new bone formation, after 2 and 4 weeks healing intervals. results: implant coated with a mixture of nano zirconium oxide and nano hydroxyl apatite showed a significantly higher removal torque values compared to uncoated one. there was more new bone formation with coated implants for both healing periods. conclusions: coating by electrophoresis considers a valuable process to coat metallic implants with a ceramic material and to form a uniform composite layer of coating. osseointegration improved at bone-implant interface associated with the coated implants, which was illustrated by higher bone formation at the two intervals of time 2 weeks and 4 weeks. keywords: implant materials, bone-implant interface, nano surface coating. (j bagh coll dentistry 2016; 28(3):30-37). introduction bone can be morphologically classified to cortical and cancellous. the cortical bone structure called compact and it responsible for mechanical support. cancellous bone is responsible for the bone metabolic functions, it surrounded by compact bones (1). the ultimate goal of using implant is the prosthetic rehabilitation of patient with missing dentition for both the functional and esthetic level (2). generally, dental implants can be classified into endosseous implants, subperiosteal implants and transosseous implants (3). dental implants differ in a lot of aspects like implant material, implant dimensions, surface properties of implants and interface geometry (4). it is important to note that osseointegration defined as the apparent direct attachment or connection of osseous tissue to an inert, alloplastic material without intervening connective tissue (5). in practice its mean that in osseointegration there was an anchorage mechanism that persists under all normal loading conditions in which non vital components can be incorporated into living bone tissue (6). (1) master student, department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of prosthodontics, college of dentistry, university of baghdad. furthermore osseointegration never occurs on 100% of the implant surface. successful cases will have range of osseointegration between 30% and 95% of dental implant surface is contact with bone tissue, as measured by light microscope (7). the technology of ceramic materials in dental applications was steadily introduced. the improvement in ceramic toughness and strength make it possible to increase the range of dental applications to dental implants and abutments (8). it has been shown that preparation techniques of titanium implant significantly affect the surface properties and also the biologic response of bone tissue that occur at the surface (9). electrophoretic process used during coating of ceramic particles on titanium substrates are of particular interest because they increase the bone healing around titanium implant. electrophoretic deposition result in homogenous deposit layer and provide easy controlling on the thickness of coated layer over a different structures (10). the purpose of this study was to evaluate the effect of mixture from nano zirconium oxide and nano hydroxy apatite as ceramic coating materials on the strength of bone-implant interface after implantation in rabbit tibia bone by means of torque test and histological analysis. j bagh college dentistry vol. 28(3), september 2016 evaluation of mechanical restorative dentistry 31 materials and methods sample preparation the substrate of coating used in the study was from titanium plate, which was cut by sharp scissor from titanium sheet to square shape specimens of (15 × 15 ×0.25mm) width, length and thickness. these ti specimens have a polished mirror surface placed in ultrasonic bath of ethanol in order to get rid of contamination and debris in 15 minutes, then for 10 minutes in distilled water bath, after that the specimens left to dry at room temperature. the platescoated with a mixture of nano zirconium oxide and nano hydroxyapatite for 3 minutes and 60 volts according to the pilot study results. pilot study in pilot study titanium plates coated with a mixture of nano zirconium oxide and nano hydroxy apatite under 60v for 1, 3, 5, 7 and 9 min (11). the plates placed in a beaker containing a mixture ofcoating particles, the anode used for particles charging. the ti specimen was attached to the cathode and a ti sheet with the same size and dimension was attached to the anode.after electrophoretic coating theplates sintered at 820°c for densification to be ready for testing by optical microscope as shown infigure 1. (12) 1min. 3min. 5min. 7min. 9min. figure 1:ti plate after coating examination of surfaces: a. microscopical examination the optical microscope (nikon type 120, japan optical microscope) with a digital camera type dxm 1200 f, used to examine the appearance of each sample of coating. from this examination specimen coated at 3min. seen with homogenous smooth surface, this specimen further analyzed by x ray diffractometer and atomic force microscope tests. b. x-ray phase analysis phase analysis was employed on the sample after coating at 3min and 60v using shimadzu lab xrd 6000 powder x ray diffractometer using cu kα radiation. c. surface roughness measurement ti plates coated at 3min and 60v were examined for surface roughness using scanning probe microscope which give information about the average roughness of the coating layer. implants preparation forty screws were machined from commercial pure titanium rods using a lathe machine with cutting head coated with titanium carbide the length of the screw was 8mm (5mm was threaded and 3mm was flat) and the diameter was 3mm.they have a slit in the head of 1.5mm depth and 1mmwidth to fit the screw driver and torque meter. these screws washed in ethanol in an ultrasonic cleaner for 15 minutes to remove the debris and contamination and then dried at room temperature as shown in figure 2. figure 2: screws shaped implants out of the 40 screws, 20 screws were left as machined implants and the remaining 20 screws were coated by electrophoretic deposition process with a mixture of nano zirconium oxide and nano hydroxyapatite (3min., 60v). coated screws sintered by using carbolite furnace for 820 ºc under inert argon gas to prevent oxidation. then the screws were sterilized with gamma radiation and kept in airtight sheets till the operation day. surgical procedure ten adult white new zealand experimental rabbits were usedtheir weight range between 1.5 to2 kg. the age of the animals was from 10-12 months. they were left for 14 days in the same environment before surgical operation. subcutaneous one dose of 10 mg ivermectin injection was given to ensure parasite free animals. each animal was weighed before operation to determine the required dose of anesthesia and antibiotic. the animals were anaesthetized with a combination of ketamine (25mg/kg) and xylazine (17.5mg/kg) intramuscularly. the legs were shaved by shaving spray, washed and decontaminated with a mixture of iodine and 70% ethanol. the tibia metaphysics was exposed by incision through skin, fascia and periosteum then the skin and fascia flap was reflected to expose the bone. bone penetration j bagh college dentistry vol. 28(3), september 2016 evaluation of mechanical restorative dentistry 32 was performed with a round guide drill to make two holes with 10 mm distance between them, continuous normal saline cooling associated with intermitted pressure at a rotary speed of 1500 rpm and reduction ratio 16:1 were used during surgery. the implant bed enlargement obtained gradually with spiral drills until size 2.8 mm. the coated screw was removed from air tight sheet, placed in the first hole (proximal one) using small screw driver which fit the implant slit until the first 5 mm of titanium implant totally inserted inside the tibia bone. the non coated screw placed in the second hole (distal one). the final screwing was done with torque meter (approximately 10 n.cm). then catgut suture 3/0 used for suturing the rabbit muscle followed by using silk suture 3/0 for skin suturing, local antibiotic applied over the operation site, followed by systemic antibiotic injection. the operation site was radiographed three times using conventional x-ray machine and per apical technique. the first one was taken prior to the surgery to ensure sufficient bone for implants and the second x-ray was taken immediately after surgery to investigate a proper position of implants, finally the third x-ray was taken before sacrificing the animal to evaluate the effect of these implants on the surrounding bone. mechanical test the same surgical instruments and anesthetic solution used in the implantation procedure. four animals were used for mechanical testing from each healing period 2 and 4 weeks using torque meter. the rabbits were anesthetized with the same dose used in the surgical phase. incision was made at the lateral tibia side then muscles and fascia were reflected and removed to expose the entire animal bone. a torque removal test applied by engaging the screw driver of the torque meter into the implant slit to measure the maximum torque necessary to unscrew the titanium implant. histological test for each healing interval 2 and 4 weeks one animal were used for histological test with optical microscope. the rabbit was injected with an overdose of anesthetic solution. cutting of the bone around the implant was performed using a disc in low rotating speed handpiece with normal saline cooling. bone-implant blocks were immediately stored in 10% freshly prepared formalin and left for 3 days for fixation. after fixation, the specimens were then left in a solution of sodium citrate and 10% formic acid in order to decalcify the bone. after 2-3 weeks the specimen was checked for complete decalcification by penetration of a narrow needle to the deepest part of the bone implant block,when decalcification complete the boneimplant block was divided into two parts using a sharp scalpel one of them containing the implant, then the implant was gently removed from its bony bed. (13) bone tissue was gradually dehydrated by being passed through a series of increasing percentage of alcohol (70%, 80%, 90% and absolute alcohol) remaining in each one for 1 hour. specimens then passed through two changes of xylene for 15-20 min and placed in a dish of melted paraffin. the dish was placed into a constant-temperature oven regulated to about 60˚c. finally, the specimens were molded in the center of paraffin block, andadjusted to a microtome where serial sections of 5-μm thickness for each part of the bone was performed one of every 10 sections was taken and placed on a slide. the slide was placed in a container having haematoxylin and eosin stain for 10 minutes to stain the tissue,then it was removed from the staining container, rinsed with deionized water and a glass cover was fixed on the stained tissue with canada balsam.photograph of each section taken by light microscope and samsung camera at x4 power magnification. results optical microscopical observations a series of micrographs illustrate the coating titanium surfaces for different times and 60 voltages. there is a homogeneous thickness layer over the titanium substrate during coating with 60v and 3 min. as shown in figure 3. figure 3: optical micrograph view of cpti coated with mixture of nano hap and nano zro2 for 3min. and 60v (100x) x-ray diffraction of coating sample after electrophoretic deposition, it is evident from figure 4 that the titanium specimen was covered by a mixture of nano zirconium oxide and j bagh college dentistry vol. 28(3), september 2016 evaluation of mechanical restorative dentistry 33 nano hydroxyapatite surface because there was diffraction peaks could be indexed to zirconium oxide and hydroxyapatite phases. figure 4: x-ray diffraction patterns of nano zro2 and nano hapcoated cpti specimen atomic force microscope of coating sample coated specimen appear with small homogenous embedded nodules with average roughness 1.95 nm which are important for the osseointegration as illustrated in figure 5.(14) figure 5: afm topographies of the coated surface in vivo experiments: clinical observations all experimental rabbits tolerated the surgical procedure and moved normally within one weekafter operation. there was no any sign of tissue reaction or bone infection seen around the overall screw bed in any rabbit. all implants were found stable in the bone, they could not be moved with manual force and there were no defect coronally around any implant after 2 and 4 weeks of healing periods. radiological observations the results of radiographic evaluation showed that there was no radiolucent zone between the cortical bone tissue and the implanted screw with all examined screws as shown in figure 6. coated non coated figure 6: radiograph of cpti implants after 4 weeks of implantation mechanical test descriptive statistics of removal torque values of uncoated implant and coated implant by electrophoretic deposition after 2 and 4 weeks of implantation are shown in table 1. the higher torque value was needed to remove the coated screws with mean value of 13.411n.cm and the lowest torque value was needed to remove the non coated screws with mean value of 8.999n.cm in the 2 weeks interval. also in the 4 weeks interval the higher torque value was needed to remove the coated screws with mean value of 20.033n.cm and the lowest torque value was needed to remove the non coated screws with mean value of 14.295n.cm as shown in figure 7. table 1: comparison of mean of torque value of coated and non coated group between 2 and 4 weeks intervals state duration n mean s.d. s.e. min. max. non-coated 2 weeks 8 8.999 1.052 0.372 7.76 10.59 4 weeks 8 14.295 2.288 0.809 11.29 17.65 coated 2 weeks 8 13.411 1.811 0.640 11.29 15.53 4 weeks 8 20.033 2.294 0.811 16.94 23.3 j bagj bagh college dentistry restorative dentistry figure 7: the differences in the torque mean t – test of the equality of torque values means between uncoated and coated screws at 2 weeks healing period showed a highly significant difference, also at 4 weeks as demonstrated in table 2, 3 table 2: t table 3: t histological the histological view of non coated titanium implants after two weeks of implantation apposition of osteoid tissue of implantimpression without detection of disti figure 8. types non coated × coated implants types non coated × coated implants h college dentistry restorative dentistry figure 7: the differences in the torque mean values between all groups test of the equality of torque values means between uncoated and coated screws at 2 weeks healing period showed a highly significant difference, also at 4 weeks as demonstrated in 2, 3. table 2: t-test for coated and uncoated implants at 2 weeks table 3: t-test for coated and uncoated implants at 4 weeks interval histological features the histological view of non coated titanium implants after two weeks of implantation apposition of osteoid tissue of implantimpression without detection of disti mean difference coated × implants -4.413 mean difference coated × implants -5.738 h college dentistry restorative dentistry figure 7: the differences in the torque mean values between all groups test of the equality of torque values means between uncoated and coated screws at 2 weeks healing period showed a highly significant difference, also at 4 weeks as demonstrated in test for coated and uncoated implants at 2 weeks interval test for coated and uncoated implants at 4 weeks interval features the histological view of non coated titanium implants after two weeks of implantation apposition of osteoid tissue of implantimpression without detection of distinct threads as shown in difference tequality of means t df -5.960 14 difference t equality t df -5.01 14 h college dentistry vol. 2 figure 7: the differences in the torque mean values between all groups test of the equality of torque values means between uncoated and coated screws at 2 weeks healing period showed a highly significant difference, also at 4 weeks as demonstrated in test for coated and uncoated interval test for coated and uncoated implants at 4 weeks interval the histological view of non coated titanium implants after two weeks of implantation illustrate apposition of osteoid tissue of implantimpression nct threads as shown in -test for equality of means df p-value sig. 14 0.000 t-test for equality of means df p-value sig. 14 0.000 vol. 28(3), september 34 figure 7: the differences in the torque mean test of the equality of torque values means between uncoated and coated screws at 2 weeks healing period showed a highly significant difference, also at 4 weeks as demonstrated in the histological view of non coated titanium illustrate apposition of osteoid tissue of implantimpression nct threads as shown in figure group at 2 weeks duration shows apposition coated with a mixture of nano zirconiu and nano hydroxyl apatite after two weeks of implantation illustrate thread of implant impression and osteoid tissue occupies apex of the thread. also bone trabeculae occupies base of implant bed close to basal bone, osteoblast rimming bone and ost shown in figure occupies base of implant bed close to basal bone (bb), osteoblast (arrow heads) rimming bone and osteocyte (arrows) can be detected. implants after four weeks of implantation illustrates threads of implant impression. immature bone can be detected at the base of the impression bed and osteocytes scattered randomly within equality of means sig. hs of means sig. hs september 2016 figure 8: microphotograph view for control group at 2 weeks duration shows apposition of osteoid tissue (arrow) histological findings of implanted screws coated with a mixture of nano zirconiu and nano hydroxyl apatite after two weeks of implantation illustrate thread of implant impression and osteoid tissue occupies apex of the thread. also bone trabeculae occupies base of implant bed close to basal bone, osteoblast rimming bone and ost shown in figure figure 9: view for bone trabeculae (bt) occupies base of implant bed close to basal bone (bb), osteoblast (arrow heads) rimming bone and osteocyte (arrows) can be detected. the histological view of non coated titanium implants after four weeks of implantation illustrates threads of implant impression. immature bone can be detected at the base of the impression bed and osteocytes scattered randomly within bone matrix as shown 2016 evaluation of mechanical : microphotograph view for control group at 2 weeks duration shows apposition of osteoid tissue (arrow) histological findings of implanted screws coated with a mixture of nano zirconiu and nano hydroxyl apatite after two weeks of implantation illustrate thread of implant impression and osteoid tissue occupies apex of the thread. also bone trabeculae occupies base of implant bed close to basal bone, osteoblast rimming bone and osteocyte can be detected as shown in figure9. : view for bone trabeculae (bt) occupies base of implant bed close to basal bone (bb), osteoblast (arrow heads) rimming bone and osteocyte (arrows) can be detected. h&e×20 the histological view of non coated titanium implants after four weeks of implantation illustrates threads of implant impression. immature bone can be detected at the base of the impression bed and osteocytes scattered randomly bone matrix as shown evaluation of mechanical : microphotograph view for control group at 2 weeks duration shows apposition of osteoid tissue (arrow) histological findings of implanted screws coated with a mixture of nano zirconiu and nano hydroxyl apatite after two weeks of implantation illustrate thread of implant impression and osteoid tissue occupies apex of the thread. also bone trabeculae occupies base of implant bed close to basal bone, osteoblast eocyte can be detected as : view for bone trabeculae (bt) occupies base of implant bed close to basal bone (bb), osteoblast (arrow heads) rimming bone and osteocyte (arrows) can be detected. h&e×20 the histological view of non coated titanium implants after four weeks of implantation illustrates threads of implant impression. immature bone can be detected at the base of the impression bed and osteocytes scattered randomly bone matrix as shown in figure 10 evaluation of mechanical : microphotograph view for control group at 2 weeks duration shows apposition histological findings of implanted screws coated with a mixture of nano zirconium oxide and nano hydroxyl apatite after two weeks of implantation illustrate thread of implant impression and osteoid tissue occupies apex of the thread. also bone trabeculae occupies base of implant bed close to basal bone, osteoblast eocyte can be detected as : view for bone trabeculae (bt) occupies base of implant bed close to basal bone (bb), osteoblast (arrow heads) rimming bone and osteocyte (arrows) can be detected. the histological view of non coated titanium implants after four weeks of implantation illustrates threads of implant impression. immature bone can be detected at the base of the impression bed and osteocytes scattered randomly 10. evaluation of mechanical j bagh college dentistry vol. 28(3), september 2016 evaluation of mechanical restorative dentistry 35 figure 10: immature bone (imb) at the base of the impression bed, osteocytes (arrow heads) scattered randomly within bone matrix.h&e×20 the coated implants at 4 weeks show interdigitation of opposing threads of implant impression and the bone surface surrounded by osteoblast. the base of implant impression close to basal bone filled by bone trabeculae and the osteocyte easily detected as shown in figure 11. figure 11: bone trabeculae (bt) coalesce with basal bone (bb). h&e×10 discussion in vitro experiments the electrophoretic deposition commercially pure titanium was satisfactorily coated with a mixture of nano zirconium oxide and nano hydroxyapatite. the electrophoretic deposition of biocompatible ceramic materials on titanium substrates considered as a step in the way of implants improvement because of the adhesion between the ceramic coating and the titanium substrate and therefore increase the implant-bone osseointegration and the lifetime of dental implant in the living tissue.(15) the electrophoretic deposition method shows a continuous thin, uniform thickness coating layer, this method form a homogenous coating thickness on the titanium implant independent on the shape or surface as illustrated by zhitomirsky (11). the study agreed with bersa and liu who confirmed the using of nanoscale particle size has a great influence on crack control of the deposit layer (16). xrd phase analysis it is obvious from the figure of the xrd (figure 4) that the specimen surface covered with the ceramic mixture because there were diffraction peaks could be indexed to zirconium oxide and hydroxyapatite phases. these phases are a stable phases at room temperature as confirmed by zhang et al. (17). the presence of ti peaks in the xrd pattern after coating process is due to the penetration of x-rays beyond the coating layer. atomic force microscope (afm) the coating method used in this study gives nano roughness which appeared from the grain size that was in nano diameter. this is also supported by the results of optical microscope. after deposition of coated layer the surface roughness increased which can be estimated from the peaks that appeared on the surface and also the diameter of grains. results measurement provided from the scanning probe microscope revealed that the coating method increases the roughness of the surface lead to increasing surface area on the implant and promote the opposition of bone which agrees with albrektsson and wennerberg (13). in vivo experiments implant preparation prior to surgery the screw type considered the most implant designs used in rabbit models. regardless of screw design, it should have an appropriate size for the bone tissue site and for the animal used. the key for implants clinical success is the primary stability in bone. it is depend on bone tissue density, the implant design and the technique of surgery.(18) the implant stable in the tibia bone after implantation and this can attributed to the screw type implant used and also to a thick cortical bone and this agreed with pearce et al. who found that the screw type implants have the advantage of producing good initial stability (19). while miyamoto et al. consider the initial stability at the implant insertion time is influenced more by cortical bone thickness than by implant length. (20) j bagh college dentistry vol. 28(3), september 2016 evaluation of mechanical restorative dentistry 36 experimental animal description rabbits used as a study model having many advantages include the ease of manipulation, rapid bone healing response compared to other models, also the metabolic activity of animal bone tissue similar to that of one third of human. (21) the age of rabbits used was about 10 months as a minimum age to ensure growth stop of the proximal rabbit tibia and more similar to bone physiology of adult human bone tissue. (22) the tibiae sites in the rabbit were chosen to mimic the clinical situation and since the dimensions of this bone correspond well with human alveolar space. also this tibia bone model has low morbidity and easy access by titanium implant, dahlin et al. stated that the rabbit tibia bone morphology allow the titanium screw to engage bone cortex at coronal area and marrow apically (23). in this study the size of the holes created in the bone was smaller than the diameter of the implant which results in a surgical fit. the holes were made 2.8 mm while the implants were 3 mm diameter, this agrees with skalak and zhao (24). radiographical examination the radiographic examination in this study demonstrated a bone to implant direct contact, there was no radiolucent zones or any abnormal reaction to the implant. however, the absent of radiolucent area is not evidence for implant-bone osseointegration, since it is impractical for a person to diagnose bone loss by x-ray at 0.1 mm resolution and the soft tissue cell size in the range of 0.01 mm for that a very narrow fibrous tissue zone undetectable by x-ray as illustrated by atsumi et al. (25). mechanical test removal torque was used in this study as an indicator for the presence of osseointegration. torque defined as the movement applied by twisting force on the body at a distance that was equal to the perpendicular distance between the force action line and the rotation center multiplied by the force magnitude.(26) this technique was used in several clinical and experimental investigations which suggest that removal torque is a useful parameter when studying and comparing screw shaped implants (27,28). effect of time on removal torque value the results illustrate that there was an increase in the removal torque value with time which may be due to progressive bone formation in bonemetal contact with time and remodeling around the implant during healing period that consequently improve the mechanical capacity, and this agreed with a removable torque studies in rabbit carried out by cho and jung (29). effect of coating surface on removal torque value the porous surface of the coating layer stimulated bone formation more than non coated surface. this finding was confirmed by suzuki et al. who reveal that porous particles in the coating layer can directly adhere to bone tissue in vivo that induce early bone ingrowth (30). clokie and bell found that the more cortical bone tissue which contacts dental implant required higher removal forces, and the surface of the coated implant increase bone to implant contact (31). in conclusion; the rabbits can normally tolerate the coating materials and the implants and that illustrated by the absent of infection. higher torque removal mean values for the coated implants compared to non coated one at two implantation periods andthis values increased with time for both coating and non coating screws. references 1. muhonen n. bonebiomaterials interface. the effects of surface modified niti shape memory alloy on bone cells and tissue. acta univ oul d 974, oulu finland 2008; 100-250. 2. henry pi. tooth loss and implant replacement. aust dent j 2000; 45: 150-72. 3. weiss cm, weiss a. principles and practice of implant dentistry. st. louis: mosby. inc; 2001. p. 3241. 4. jokstad a, braegger u, brunski jb, carr ab, naert l, wennerber a. quality of dental implants. int j prosth 2004; 17: 607-41. 5. gpt glossary of prosthodontic terms. j pros dent 2005; 94 (1): 10-92. 6. branemark p i. the branemark novum protocol for same-day teeth. a global perspective. chicago: quintessence; 2001. p. 9-29. 7. linder l, albrektsson t, branemark pi et al. electron-microscope analysis of bonetitanium interface. acta orthop scand 1983; 54: 45. 8. denry i and holloway ja. ceramics for dental applications: a review. materials 2010; 3: 351-68. 9. keller jc, draughn ra, wrightman jp, dougherty wj, meletiou sd. characterization of sterilized cp titanium implant surfaces. int j oral maxillofac implants1990; 5: 360-9. 10. besra l, liu m. a review on fundamentals and applications of electrophoretic deposition (epd).prog mater sci 2007; 52: 1–61. 11. zhitomirsky i. ceramic films using cathodic electrodeposition. j minerals, metals and materials society 2000; 52(1): 1-11. j bagh college dentistry vol. 28(3), september 2016 evaluation of mechanical restorative dentistry 37 12. meng x, kwon t, kim k. hydroxyapatite coating by electrophoretic deposition at dynamic voltage. dent mater 2008;27(5): 666-671. 13. linder l. high-resolution microscopy of the implant tissue interface. acta ortho scand 1985; 56: 269-72. 14. albrektsson t, wennerberg a. oral implant surfaces: part1–review focusing on topographic and chemical properties of different surfaces and in vivo responses to them. int j prosthodont 2004; 17(5): 536-43. 15. hamad ti. histological and mechanical evaluation of electrophoretic bioceramic deposition on ti6 al 7nb dental implants, a phd thesis, college of dentistry, university of baghdad, 2007. 16. besra l, liu m. a review on fundamentals and applications of electrophoretic deposition (epd). prog mater sci 2007; 52: 1–61. 17. zhang f, chupas pj, lui sla, jonathan c, hanson jc , caliebe wa, lee opl and chan s-w. in situ study of the crystallization from amorphous to cubic zirconium oxide: rietveld and reverse monte carlo analyses. chem mater 2007; 19: 3118-26. 18. sennerby l, meredith n. resonance frequency analysis: measuring implant stability and osseointegration. compend contin educ dent1998; 19: 493-8. 19. pearce a, richards arg, milz s, schneider e, and pearce sg. animals models for implantation biomaterial research in bone: a review. european cells and materials 2007; 13: 1-10. 20. miyamoto i, tsuboi y, wada e, suwa h, and iizukat. influence of cortical bone thickness and implant length on implant stability at the time of surgery—clinical, prospective, biomechanical, and imaging study bone 2005; 37(6): 776-80. 21. kim e, park e, choung p. platelet concentration and its effect on bone formation in calvorial defects: j prosthet dent 2001; 86: 428-33. 22. michaels gc, carr ab, larsen pe. effect of prosthetic superstructure accuracy on the osseointegrated implant bone interface.oral surg oral med oral pathol 1997; 83(2):198-205. 23. dahlin c, sennerby l, lenkholm u, linde a, nyman s. generation of new bone around titanium implant using membrane technique: an experimental study in rabbits. int j oral maxillofac implant 1989; 4 (1): 1925. 24. skalak r, and zhao y. interaction of force-fitting and surface roughness of implants.clin implant dent rel res 2000; 2: 219-24. 25. atsumi m, park s, wang h. methods used to assess implant stability:current status. int j oral maxillofac implant 2007; 22: 743-54. 26. hoda y, allyn l, jack r, saul w. analysis of changes in implant screws subject to occlusal loading: a preliminaryanalysis. implant dentistry 2005; 14: 378-85. 27. gotfredson k, nimb l, hjorting he, jensen js. a histomorphometric and removal torque analysis for tio2.blasted titanium implants.an experimental study on dogs. clin impl dent res 2001; 3: 77-84. 28. al-mudarris ba. the significance of biomimetic calcium phosphate coating on commercially pure titanium and ti-6al-7nb alloy. a phd thesis, college of dentistry, university of baghdad, 2006. 29. cho sm, and, jung s-k. a removal torque of the laser-treated titanium implants in rabbit tibia. biomaterials 2003; 24: 4859–63. 30. suzuki t, fujibayashi s, nakagawa y, noda i, nakamura t. ability of zirconia double coated with titanium and hydroxyapatite to bond to bone under load-bearing conditions. biomaterials 2006; 27: 9961002. 31. clokie cm, bell rc. recombinant human transforming growth factor beta-1 and its effects on osseointegration. j craniofac surg 2003; 14(3): 268 77. j bagh college dentistry vol. 29(1), march 2017 effect of tea tree restorative dentistry 55 effect of tea tree, thymus vulgaris and nigella sativa oils on the elimination of enterococcus faecalis (in vitro study) rafid j. al-badr, b.d.s. (1) hussain f. al-huwaizi, b.d.s., m.sc., ph.d.(2) abstract background: the main goal of chemomechanical endodontic treatment is the reduction or elimination of microorganisms from root canal system. the intracanal medicaments were used to enhance the disinfection process. this study was conducted to evaluate the antibacterial effect of thymus vulgaris, tea tree essential oils and cold pressed black seed oil (bso) against e.faecalis. materials and methods: e.faecalis was isolated from ten patients in need for endodontic treatment. the sensitivity of e.faecalis to the tested oils was evaluated in different concentrations in agar well diffusion method and compared with calcium hydroxide. the sensitivity of e.faecalis to vapor of the tested oils was also evaluated, in disk vaporization method using inverted agar plate and compared to tricresol formalin (tc) and camphorated monochlorophenol (cmcp). the micro broth dilution method was used to evaluate the minimum inhibitory concentration (mic) and the minimum bactericidal concentration (mbc) of the tested oils against e.faecalis. the presence of biologically active volatile components of two samples of bso with different origins was evaluated by the use of high performance liquid chromatography (hplc). results: all the tested oils exhibited antibacterial activity against e.faecalis in different concentrations with different levels in agar well diffusion and disk vaporization methods. the mbc was 2µl/ml, for thymus vulgaris oil and 32µl/ml for tea tree and black seed oils. the vapor forming medicaments (tc and cmcp) induced effective antibacterial action but calcium hydroxide showed a low antibacterial action against e.faecalis. the active volatile components were present in one sample of bso only (the iraqi one). conclusion:the three oil extracts were active against e.faecalis, and the origin, condition of storage and method of extraction may affect the components of cold pressed black seed oil. keywords:essential oils, e.faecalis, intracanal medicaments, calcium hydroxide. (j bagh coll dentistry 2017; 29(1):55-62) introduction the main goal of chemomechanical endodontic treatment is the removal or severe reduction of microorganisms present in the root canal system. the complex anatomy of root canal system and the remaining bacteria in some areas like ramifications, accessory canals and dentinal tubules may prevent this goal to be achieved completely. therefore, the use of intracanal medicaments was advocated to promote the elimination of remaining bacteria and their byproducts from the root canal system (1,2). e.faecalis is the bacterial species related mostly to persistent endodontic infection causing failure endodontic treatment due to its resistance to some known intracanal medicaments e.faecalis is capable to live within the root canal and resist difficult conditions like starvation and high ph.(3). ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ (1)master student, conservative department, college of dentistry, university of baghdad. (2)professor, conservative department, college of dentistry, university of baghdad. because no intracanal medicaments traditionally used as dressing have all the required properties like inhibition and prevent recolonization of all bacteria in the root canal system, and some of medicaments irritate the periradicular area or with cytotoxic effects (4), so there is a trends toward finding new agents with good antibacterial activity and less or not irritate to the periapical area (5). herbal or natural derivatives have been used in dental and medical practice for long time and became even more popular today due to their antimicrobial activity, biocompatibility, lack of microbial resistance, anti-oxidant, antiinflammatory, easy availability and low cost properties (6,) materials and methods patient selection and isolation of bacteria: ten patients diagnosed with pulpal necrosis with periapical changes indicated for endodontic treatment were included in this study. all the selected teeth were single rooted teeth. the age of the patient ranged from 25-45 years. the teeth were symptomatic and the diagnosis confirmed by radiographic examination that was done in j bagh college dentistry vol. 29(1), march 2017 effect of tea tree restorative dentistry 56 diagnostic unit in a specialized dental center(karbala). the patients under antibiotic treatment and the teeth with severely destructive crown that interfere with placement of rubber dam were excluded. the field was isolated by using rubber dam in a septic procedure was done by 10 % povidone iodine solution to the tooth and the field around it. the access cavity was prepared in two steps the first was the removal of all carious lesions and/or coronal restorations by a sterile carbide fissure bur, then disinfecting the field again. the second step was opening access cavity to the pulp chamber by using a low speed round carbide bur. new sterile files were introduced into the root canals to the end of the working length (confirmed by x-ray) to remove the content of root canals, followed by enlargement of the canals with minimal instrumentation to the size 20# without use of any irrigants. the canal was flooded with sterile saline solution and agitation vertically with file was done in order to form a suspension of bacteria from all the parts of the root canal(7). then two paper points were inserted to the full working length and kept for 60 seconds until the canal was dry. they were transferred directly and immediately to a tube of sterile transport media (amies)(8).the samples were transported to the laboratory within two hours for isolation and identification. (9) identification of micro-organism: 1morphological characteristic:examination was done directly on blood and pfizer agar plates, and according to the description cited by public health england (2014).(10) 2-gram’s stain:slide of suspected bacteria was prepared and gram’s stain method was performed to identify the gram’s positive property of e.faecalis.(10) 3-catalase production test: drop of 3% hydrogen peroxide immediately placed on microorganismson a sterile slide. the evolution of bubbles of gas indicated a positive test, no reaction (no bubbles) indicate catalase negative test.(10) 4-analytic profile index (api): this test was done according to manufacturer’s instructions using api 20 strep identification kits a standardized system combining 20 biochemical tests. it enables species identification of most streptococci and enterococci, and those most common related organism.(11) 5-mast strep test;procedure was doneaccording to manufacturer’s instructions by picking up 2-6 colonies of suspected e.faecalis from freshly growing overnight culture and suspended in 0.4 ml extraction enzyme then added one drop ofsuspension to one drop of latex reagent previously placed on the test card.(12) test the sensitivity of e.faecalis to different concentrations of thyme oil (to), tea tree oil (tto), and black seed oil(bso): agar well diffusion method: five different concentrations (75%-50%-25%12.5%) beside 100% were prepared of the three experimental oils (to, tto oils4life/uk. and bsoal-emad co. iraq) by diluting the oils with dimethyl sulfoxide (dmso) (cdh co., ltd.india).the procedure was done by mixing 10% dmso solution to experimental oils in 3:1, 1:1, 1:3 and 1:7(oil: 10%dmso)(13).mha(himedia/india) media in petri dish was inoculated with 100µl of e.faecalis suspension that was prepared as 0.5 mcfarland (turbidity standard).the inoculum was spread in all directions by mean of sterilized cotton swap. four wells of equal size (6 mm in diameter) and 4 mm depth were prepared in each agar plate; two wells were filled with 100 µl of two different concentrations of the test oil. one well was filled with 10%dmso solution as negative control, the last well filled with ca (oh)2. plates incubated aerobically for 18-24 hours at 37oc. zone of inhibitions which is clear zone of no growth of the bacteria were measured across the diameter of each well by using a digital vernier caliper, no zone indicated a complete resistance of bacteria to the agents (14). test the sensitivity of e.faecalis to a vapor of tto, to, and bso: the inoculated petri dishes was sterilized and inverted, filter paper disk of 5 mm diameter was impregnated with 15 µl of each experimental oil concentrations, tricresol formalin and cmcp, then placed on the inner surface of the lid of the petri dish (one disk for each plate). the petri dish was wrapped by a laboratory parafilm to keep the vapor of the medicament inside. plates were incubated aerobically for 18-24 hour at 37oc. zone of inhibition which is clear zone of no growth of the bacteria was measured by digital vernier caliper (15). determination of mic of the tested oils: bacterial inoculation was prepared by direct colony suspension method to reach 0.5 mcfarland that equal to 1*108 bacterial cell/mlwith mueller j bagh college dentistry vol. 29(1), march 2017 effect of tea tree restorative dentistry 57 hinton broth (mhb)(himedia/india).in the first well of microtiter (96-wells plate) 12.8 µl of the tested oil was placed and mixed with 184 µl mhb broth and 3.2 µl dmso, so the final volume in the first well is 200µl.then eight concentrations of oils was ranged 32-0.25µl/ml was prepared in next seven wells. final concentration of dmso ≤0.8% v/v (16).then one well was added with 200µl of uninoculated media serve as negative control and other one with inoculated media serve as positive control.the last concentration that lacks visual turbidity matching the (-ve) control was considered as mic,and the result confirmed with subculture of 10 µl from each well to determine if the inhibition was reversible or permanent. determination of mbc of the tested oils: the final sub culture were done by taking 10 µl from each (well mixed) well and cultured on agar plates to identify the mbc.the mbc was the first concentration higher or equal to mic with no growth on agar media. (17) hplc analysis of two types of bso one of them made in iraq and the other made in the united kingdom for determination of active volatile components (thymoquinone): samples from the two bso was analyzed by hplc. the separation occurred on liquid chromatography shimadzu lc-20ad, the eluted peaks were monitored by spd-20a uv/vis detector spectrophotometry. the active compounds of bso separated on flc (fast liquid chromatographic) column (100-10 c18), mobile phase utilized was composed of water: methanol: 2-propanol (50:45:5% v: v), uv monitoring was carried out at 254 nm for thymoquinone, dithymoquinone. flow rate was 2 ml/min. the result was compared with standard figure (18). results: identification of e.faecalis: the tested colonies were identified as gram positive, catalase negative, grow well on blood agar as circular smooth elevated entire edged and the size of colony about 1-2mm, with no hemolysis. e.faecalis grow well on pfizer agar with blackening around the colony. the result was confirmed by api 20 and mastastrep latex coagglutination test when visible aggregation of the latex particles, within few seconds of mixing of the bacteria with the specified reagent appeared. sensitivity of e.faecalis to different concentrations of tto, to, and bso: agar well diffusion method: the diameter of inhibition zone was found to increase as the concentrations of the oils increases. ten percent dmso showed no zone of inhibition while ca(oh)2 showed small to moderate zones of inhibition compared to all the tested oils concentrations as shown in table (1). one way anova was performedamong different concentrations of each oil as in table (1). least significant difference (lsd) test was used between different concentrations of tested oils and ca(oh)2, as in table (2). it was found that a highly significant difference between ca(oh)2 and all agents except between ca(oh)2, to 12.5% and tto 12.5% there isno significant difference. test the sensitivity of e.faecalis to a vapor action of tto, to, and bso: the diameter of inhibition zonewas found to increase as the concentrations of the oils increases. ten percent dmso showed no zone of inhibition, t.c showed a large zone of inhibition larger than cmcp, to, tto except for bso, t.c nearly equal to 50% bso, and less than bso 100% and bso75%. cmcp showed a zone of inhibition more than tto 100% and to 75%, and less than t.c, to100%, and bso 100%, 75%, 50%. not all tested concentrations give inhibition zone in vapor action method as in table (3). one way anova was performed among different concentrations of each oil as in table (3), and (lsd) test used between different concentrations of tested oils, t.c, and cmcp as in table (4). it showed a highly significant difference between t.c and all agents except between t.c and bso 50% ,75% , were no significant difference, and for cmcp the table showed a highly significant difference with all tested concentrations except tto100% there was no significant difference. determination of mic and mbc of to, tto, bso: the mic of to was 1µl/ml, and mic for bso and tto were 16 µl/ml. the mbc was 2 µl/ml for to and 32 µl/ml for tto, bso. hplc analysis of two types of bso one of them made in iraq and the other made in united kingdom for determination of active volatile components (thymoquinone): the result showed exact match in retention time of thymoquinone between bso iraq and the reference chart also the result chart showed presence of thymol and dithymoquinone in bso iraq as in figure (1).the resulted chart of bso uk show no j bagh college dentistry vol. 29(1), march 2017 effect of tea tree restorative dentistry 58 matching with any retention time of the reference one. discussion biocompatibility, low toxicity, lack of microbial resistance, easy availability and low cost are the major advantages of using herbal alternatives in endodontic dentistry (19). in this study the results of sensitivity test showed that towas able to inhibit the growth of e.faecalis at different concentrations. this finding was in coincidence with silva et al.,(2013).(20) the diameter of inhibition zones increased as the concentration of thymus vulgaris essential oils increased from 12.5% to 100%. this result come in agreement with mith et al., (2013)(21) who studied the antimicrobial properties of to using agar diffusion method against different types of microorganisms and the results supported the hypothesis that increasing concentration of to would increase the inhibition of bacterial growth and to possesses antimicrobial activity on different microorganisms. to of 25%, 50%, 75% and 100% concentrations showed larger inhibition zones than ca(oh)2, and statistically all these concentrations presented highly significant difference, which suggests that they have higher antimicrobial activity than ca(oh)2. there was no significant difference between to 12.5% and ca (oh)2 and this finding presents a great promise to use to as an alternative to ca (oh) 2. in this study to showed powerful antibacterial activity with larger inhibition zone than tto with statistically significance difference in all concentrations except 12.5% there was no significance difference. this result is in coincidence with another study on these two essential oils tested on another type of bacteria like erythromycin-resistant group a streptococci (22). in this study to showed inhibition zone comparable to bso, with larger zone in concentration 100% than bso, but the inhibition zones of to was smaller than the zone formed by bso for other tested concentrations. this activity of to may be due to its biological active constituents thymol and carvacrol, such compounds were reported to have an active effect on the bacterial cells membrane, which might destroy these microorganisms (22). in the present study the results of sensitivity test showed that tto was able to inhibit the growth of e.faecalis at different concentrations. this finding was in agreement with (23). the antimicrobial activity of tto on different microorganisms at different concentrations with increased activity when the concentrations increased were verified by many studies (24, 25). in the present study tto at 25%, 50%, 75% and 100% concentrations showed larger inhibition zones than ca (oh)2, and smaller inhibition zone than to. statistically all these concentrations showed highly significant difference, which suggests that they have higher antibacterial activity than ca(oh)2 and lower antibacterial activity than to but there was no significant difference between to 12.5%, tto 12.5 and ca(oh)2. tto showed smaller inhibition zone than bso in all tested concentrations with highly significant difference. the antibacterial activity of tto may be due to its active constituent terpinen-4-ol, and /or other constituents like alpha terpinene, such components were reported as antibacterial agents when used alone or as constituents of tto. the suggested mechanisms of action of tto were inhibition of respiration of bacterial cell, loss of intracellular material and /or loss of membrane integrity and function (26). cold pressed black seed oil was tested in this study in different concentrations and the result showed a promising antibacterial activity with large inhibition zones with statistically high significance difference when compared to ca (oh) 2,tto, 25% and 12.5% concentrations of to, and there was no significance difference between bso and 50% ,75%,100% to. these results were in coincidence with youssef et al., (2013)(27) who tested pure bso in different concentrations on microorganisms isolated from surgical wounds infections and they found sensitivity of e.faecalis to bso. majeed, (2006)(28) tested the activity of cold press black seed oil on common pathogenic bacteria related to root canal infection and the result showed good and comparable antibacterial activity to krezoform. the antibacterial activity of bso is related directly to its active constituent thymoquinone and its related compounds thymohydroquinone and thymol. these active volatile constituents are present in low percent in cold pressed oil and itshighly sensitive to light, heat, depends onsource of seed and extraction method (29). in this study calcium hydroxide (ca (oh)2 was found to have a minimal antibacterial activity in agar diffusion method which coincides with alj bagh college dentistry vol. 29(1), march 2017 effect of tea tree restorative dentistry 59 huwaizi (2000)(30) and ballal et al., (2007)(31) who found that ca (oh)2 combined with distilled water had minimal antibacterial activity in the agar diffusion model. the result of the present study disagrees with mehrvarzfar et al., (2011)(32) who found calcium hydroxide have superior antibacterial effect on e.faecalis than bioglass 45s5 in direct exposure test. test the sensitivity of e.faecalis to a vapor action of tto, to, and bso: the antibacterial activity of cmcp was found to be inferior to tc and this result agrees with alhuwaizi (2000)(30), who stated that the vapor action of tc was more effective than cmcp in eradication of microflora in necrotic root canals. the results of this study also agrees with silva etal., (2012)(33), who found tc vapor effectively inhibited e.faecalis in vitro. in the present study e.faecalis was sensitive to vapor action of 100%, 75% to and 100% tto and the result of inhibition zone was comparable to cmcp and smaller than tc and bso. the result of to vapor action of this study was in agreement with khadir et al., (2013)(34) who stated that e.faecalis was sensitive to vapor of one type of thymus genus. the result is also in agreement with dobre et al., (2011)(15) who found that the vapor of to has a good antimicrobial action against some types of gram positive and negative bacteria beside different types of fungi. the antibacterial and antifungal activity of tto vapor against many types of bacteria and fungi was examined also (inouye et al.,2006).(35) in the present study the bso vapor action was promising. the inhibition zones of bso 100%, 75% concentrations were greater than the biggest zone in this study that formed by tc, and the 50% concentration of bso was comparable to tc with 30 mm zone of inhibition. this result complies with majeed, (2006)(28) who stated that vapor of cold pressed black seed oil exhibit antibacterial action comparable to krezoform against different aerobic and anaerobic necrotic root canal bacteria. determination of mic and mbc of to, tto and bso: the mic of to was found to be 1 µl/ml and the mbc of to was 2 µl /ml. the result of mic complies with sienkiewicz etal., (2012)(36), who found the mic of to against e.faecalis was 0.5 µl /ml for bacteria isolated from urine, 0.75 µl /ml for bacteria isolated from wound and 1.25 µl /ml for bacteria was isolated from bed sore. the mic of tto was found to be 16 µl /ml and the mbc was 32 µl/ml and this result is in agreement with rusenova and parvanov, (2009)(37)who found the mic of tto for standard e.faecalis was 1.0 % v/v. this result disagree with some studies that may be due to different types and sources of bacteria, method used in the study of mic, type of broth used and source of essential oil (17,38). the mic of bso was 16 µl /ml and the mbc was 32 µl /ml. there is no available research concerned with mic and mbc of the cold pressed black seed oil extract against e.faecalis. hplc analysis of two types of bso one of them made in iraq and the other made in united kingdom for determination of active volatile components (thymoquinone): in the present study the hplc analysis of cold pressed black seed oil from iraq showed matching in the area of retention time of volatile components (thymoquinone. dithymoquinone and thymol) with the reference chart. the sample from cold pressed black seed oil manufactured in uk when analyzed showed no matching with any of the active volatile components in the reference chart. the result of differences in biologically 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hf. the use of acetic acid as a new intracanal medicament, a bacteriological, histopathological, and clinical study. ph.d.thesis, college of dentistry. baghdad .2000. 31-ballal v, m kundabala, s acharya, m ballal.antimicrobial action of calcium hydroxide, chlorhexidine and their combination on endodontic pathogens.aus dental j 2007; 52: (2):118-21. 32-mehrvarzfar payman, hengamehakhavan, hosseinrastgarian, nahidmohammadzadeakhlagi, reza soleymanpour, anahidahmadi.an in vitro comparative study on the antimicrobial effects of bioglass 45s5 vs. calcium hydroxide on enterococcus faecalis. ira end j 2011; (1)6: 29-33. 33-silva emmanuel jnl, evelyn goldberg, natasha cc ajuz, claudio m. ferreira. antimicrobial evaluation of vapors of paramonochlorophenol and tricresol formalin using a new methodology. revistabrasileira de odontologia 2012; (69)2: 255-57. 34-khadir a, bendahou m, benbelaid f, abdoune ma, abdelouahid de. pouvoirantimicrobien de thymus lanceolatusdesf. récolté en algérie. phytothérapie 2013; 11:353-8. 35-inouye s, nishiyama y, uchida k, hasumi y, yamaguchi h, abe s. the vapor activity of oregano, perilla, tea tree, lavender, clove, and geranium oils against a trichophytonmentagrophytes in a closed box. j inf che 2006; 12:349-54. 36-sienkiewicz m, lysakowska m, denys p, kowalczyk e. the antimicrobial activity of thyme essential oil against j bagh college dentistry vol. 29(1), march 2017 effect of tea tree restorative dentistry 61 multidrug resistant clinical bacterial strains. mic drug res 2012; 18: 137-48. 37-rusenova n., parvanov p.antimicrobial activities of twelve essential oils against microorganisms of veterinary importance. tra j sci 2009; (7)1: 37-43. 38-ahmad a, van vuuren s, viljoen a. unravelling the complex antimicrobial interactions of essential oils--the case of thymus vulgaris (thyme). molecules 2014; 19: 2896-910. table 1: anova, mean, s.d of inhibition zone in millimeter of e.faecalis to different concentrations and different agents (agar well diffusion methods). agents no. mean s.d anova to 100% 10 31.507 0.784 f=228.290 d.f=15 p=.000 75% 10 27.971 1.203 50% 10 26.27 2.092 25% 10 19.594 1.003 12.5% 10 12.105 1.378 tto 100% 10 24.122 3.093 75% 10 22.288 2.047 50% 10 19.156 1.553 25% 10 18.288 0.841 12.5% 10 11.071 1.111 bso 100% 10 30.577 0.907 75% 10 28.118 1.027 50% 10 27.305 0.947 25% 10 25.492 0.651 12.5% 10 17.57 1.017 ca(oh)2 10 10.975 0.607 10%dmso 10 0 0 table 2: lsd between ca(oh)2 and each concentration of each oil. agents concentrations% mean difference p-value description to 100 -20.53 .000 hs 75 -16.99 .000 hs 50 -15.29 .000 hs 25 -8.61 .000 hs 12.5 -1.13 .076 ns tto 100 -13.14 .000 hs 75 -11.31 .000 hs 50 -8.18 .000 hs 25 -7.31 .000 hs 12.5 -0.09 .880 ns bso 100 -19.60 .000 hs 75 -17.14 .000 hs 50 -16.33 .000 hs 25 -14.51 .000 hs 12.5 -6.59 .000 hs j bagh college dentistry vol. 29(1), march 2017 effect of tea tree restorative dentistry 62 table 3: anova, mean, s.d of e.faecalis inhibition zone in millimeter of different concentrations and different agents (vaporization method). agents no. mean s.d anova t.c 10 30.867 0.584 f=514.863 d.f=7 p=.000 cmcp 10 13.779 1.248 to 100% 10 18.529 0.904 75% 10 11.319 1.009 tto 100% 10 13.172 1.019 bso 100% 10 34.598 2.248 75% 10 32.038 1.644 50% 10 30.104 1.503 10%dmso 10 0 0 table 4: lsd among t.c, cmcp and each concentration of tested oils(vaporization) control agents mean difference p-value description t.c to100% 12.33 .000 hs 75% 19.54 .000 hs tto 100% 17.69 .000 hs bso 100% -3.73 .000 hs 75% -1.17 .058 ns 50% .76 .214 ns cmcp to100% -4.75 .000 hs 75% 2.46 .000 hs tto 100% .60 .322 ns bso100% -20.81 .000 hs 75% -18.25 .000 hs 50% -16.32 .000 hs j bagh college dentistry vol. 29(1), march 2017 stressful life events pedodontics, orthodontics and preventive dentistry 139 stressful life events in relation to dental caries and selected salivary constituents among secondary school students in baghdad city ahmed k. abdul-ameer, b.d.s.(1) nada j. radhi, b.d.s., m.sc., ph.d.(2) huda j. abdul-ghani, b. psychology, m.sc., ph.d.(3) abstract background: stress is the reactions of the body to forces of a deleterious nature, infections and various abnormal states that tend to disturb its normal physiological equilibrium; it is described as adverse emotions or reactions to unpleasant experiences; thus, any real or perceived physical, social, or psychological event or stimulus that causes bodies to react or respond have deleterious effects on the general and oral health. the aims of this study were to assess the severity of dental caries among the students with different categories of stressful life events in relation to physicochemical characteristics of whole stimulated saliva. materials and methods: the total sample is composed of 300 students (males only) aged 17-18 years old, who are randomly selected from 10 school in the first al-karkh/baghdad. the total sample classified into three categories (less stress, more stress, accumulative stress) according to stressful life events scale (sle); the sub sample consist of 60 students who are randomly selected from the total sample each category composed of 20 students. diagnosis and recording of dental caries was assessed according to decay, missed, filled surface index (d1-4mfs) of muhlemann (1976). stimulated salivary samples were collected from the 60 students then measuring salivary flow rate; and chemically analyzed to determine salivary interlukin-6 (il-6), cortisol, and total protein. all data were analyzed using spss version 21. results: results recorded the highest mean rank value of (dmfs) was among the accumulative stress category of stressful life events scale followed by more stress category, the lowest mean rank value was among less stress category with statistically high significant difference (p< 0.001). for the severity of dental caries (ds) fraction was higher among the accumulative stress category than more stress and less stress categories respectively (p< 0.001). according to the grades of lesion severity, for all fractions the higher mean rank values was among accumulative stress category with no statically differences except for (d2) was significant (p< 0.05). the data from salivary analysis showed that, the highest values of salivary total protein and (il-6) were among the accumulative stress category, followed by more stress then the lowest value among less stress category, while the cortisol showed the opposite picture, however all these differences were not significant. dmfs correlated positively with flow rate among less stress and accumulative stress categories and negatively with more stress category, while for (ds) correlated negatively with flow rate with highly significant for more stress category and accumulative category and positively related with significant for low stress category. the salivary constituents showed negative correlation with (dmfs) for all categories of stressful life events scale except for il-6 and cortisol were positively correlated for accumulative category with nonsignificant difference. conclusion: the study revealed that, stressful life events have a significant deleterious impact on the oral and dental health including caries experience as well as the effect on the normal levels of salivary constituents. keywords: stressful life events, stress, dental caries, cortisol, total protein, il-6.(j bagh coll dentistry 2017; 29(1):139147) introduction stress is the most important concept that underlines all the attempts to understand the influences of social experience, events and physiological factors on the general health and oral health (1). stress was originally derived from the latin word “stringi” which means, “to be drawn tight”. it is “an inharmonious fit between the person and the environment, one in which the person’s resources are taxed or exceeded, forcing the person to struggle, usually in complex ways, to cope” (2). one of the theories that try to explain influence of stress on health revealed that, if people perceive an event as more than they could (1)m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assist. professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (3)assist. professor, director of psychological laboratory, psychological research center, ministry of higher education and scientific research. deal with and exceed the resources available to them, then only at this point do they perceive stress that could lead to disease (3). a subject exhibits stress response or not depends upon the factors, including coping behaviors, genetic predisposition, concomitant stressors, level of social support and their lifestyle factors (4). there are two kinds of stress: acute and chronic: acute stress (short-term stress) is typically intense, flares quickly, and disappears quickly such us stress response that prepare the immune system for challenges like infection imposed by stressor. although chronic stress may not feel as intense, it can linger indefinitely and wreak silent havoc on body’s systems (5). in fact, stressful life events across multiple domains have been shown to increase over the course of adolescence (6). this has been associated with increases in depression, anxiety, low self-esteem, and behavioral j bagh college dentistry vol. 29(1), march 2017 stressful life events pedodontics, orthodontics and preventive dentistry 140 problems (7). stressful life events detract from self-care behavior, consequently, the existence leads to the neglect of the duties of the medical care, including oral health (8). some health psychologists have studied the effects of significant life events, people who have had major life changes (loss of spouse or other close relative, loss of job) have a higher incidence of cardiovascular diseases and early death than those who do not (9). other researcher had evaluated the effects of clusters of life events and their possible influence on mental and physical health (10). because of the circumstances experienced by the people in the iraqi environment, particularly adolescents it was necessary to adopt an accurate scale to measure the relationship of these non-natural events with oral health; so the researcher adopted stressful life events scale (sle), which is specific scale designed to measure the stress of life events by using questioneers which consisted of (30) items distributed to four categories (loss, social rejection, poverty, loss of safety), for each event two alternatives (passed, not passed), so the students have to answer for each event pass or not (11). adolescents face various transitions and challenges, including puberty, poverty, schools changes, investment in peer, and changes in relationships with family (12). however, each of these events has the potential to become sources of stress; in general, adolescence is considered important for oral health, because majority of individuals during this period have tendency to gain independence in making personal and diet related choices. moreover, iraqi children had been exposed to fighting in the streets, passing dead bodies on the way to school, seeing relatives and friends killed or severely injured, and other actions of war and occupation (13). psychological health is recognized as a key public health issue for conflictaffected population (14). dental caries is one of the most prevalent oral diseases of public health concern affecting all ages including adolescents (15). oral health behaviors are established and habits are formed during adolescence, heavily influenced by the social environment related to peers (16). the relation between stress and increased susceptibility of dental caries was demonstrated in a several studies (1,3,17,18). the protective functions of saliva and the association between oral disease and psychological factors is considered. it is surprising how psychological stress can alter the defense systems in saliva. psychological stress produce change in salivary flow and components (19). the relation between stress and salivary flow rate was controversy, some studies showed that the salivary flow rate does not change during stress responses (20); while other found that reduce salivary flow rate in relation to psychological conditions (21). on the other hand many studies suggested that salivary total protein level increase in response to psychological stress by number of mechanisms (22,23,24). saliva is a mirror to the general health condition that reflects various systemic changes in the body (25).where the composition of saliva immediately reflects the sympathetic and parasympathetic nervous systems, hypothalamicpituitary-adrenal (hpa) axis and immune system response to stress (26); levels of salivary il-6 and other proinflammatory cytokines can be directly stimulated by stressful experiences and depression other negative emotions. indeed, both physical such as exercises and psychological stressors can provoke increases in proinflammatory cytokines (27). cytokines are closely associated with the pathogenesis of inflammation in oral soft tissues (28,29), and evidence indicates that they contribute to the initiation and progression of dental caries (30). saliva contains free, biologically active cortisol as opposed to total cortisol present in serum or plasma and the concentration of cortisol in saliva is independent of the salivary flow rate (31,32). salivary cortisol is capable of affecting local, mucosal immunity and oral microbial flora, and that mucosal immune competence affects bacterial colonization and growth (33). it affects the performance of some immune system cells (34). basal salivary cortisol and cariogenic bacteria were the strongest predictors of dental caries, and from a theoretical perspective, salivary cortisol could plausibly suppress mucosal immunity against cariogenic bacteria (35,36). in iraq, several studies were conducted regarding the relation between dental disease with salivary total protein, cortisol and interleukine-6. yet, no previous iraqi study conducted to search stressful life events in relation to dental caries, salivary total protein, cortisol and interleukin 6 among 17-18 years old secondary school students in baghdad city/iraq. for all these explanations, this study was designed. materials and methods the sample consist of 300 students (males only) aged 17-18 years old, who are randomly selected from 10 secondary school in the first al-karkh/baghdad. oral examination and stressful life events were recorded for all students by mean of self recorded questionnaire j bagh college dentistry vol. 29(1), march 2017 stressful life events pedodontics, orthodontics and preventive dentistry 141 using stressful life events scale (sle) which designed for this purpose, this scale characterized by validity and be appropriate for the iraqi environment and able to measure different and various types of stress (11). for salivary analysis, sub sample of 60 students (20 students selected randomly from each category). caries severity was diagnosed by decay, missing, filling surface index (d1-4mfs) according to criteria suggested by muhlemann (37). plane mouth mirror and dental explorer were used. the collection of stimulated saliva from the total sample (300 students) were performed before the students answering questionnaire of (sle) scale and under standard condition following instruction cited by tenovuo and lagerl (38). each participant was asked to sit in comfortable position and chew a piece of arabic gum (0.5-0.7 gm) for one minute then all saliva was removed from mouth by expectoration , after that chewing was continued for 10 minute with same piece of gum and the salivary samples was collected in sterile screw capped tubes. salivary flow rate was determined before centrifuged the samples after the foam was faded by dividing the total volume of collected saliva (stimulated) in milliliter on the total time of saliva collection in minute (ml/min) (39). the samples of saliva were taken to the laboratory for centrifuge at 3000 rpm for 15 min; then the clear supernatant was separated by micropipette and was divided to 3 portions , stored at (-25 c) in a deep freeze until the time of biochemical analysis in the teaching laboratories in the medical city hospital and poisoning center. total protein (mg/dl) determined by colorimetric method, syrbio kit was used according to the manufactured instructions (40). for determination of il-6 in saliva, commercially available elisa was used and performed as recommended in leaflet with kit (salimatrics company, usa) (41). measurement of salivary cortisol was done by means of high sensitivity, salivary cortisol enzyme-linked immunosorbent assay (elisa), based on the principle of competitive binding (demeditec company, germany) (42). non-normally distributed variables were conveniently presented by median and mean rank. the kruskal-wallis test was used to assess the statistical significance of difference between more than 2 groups. the spearman linear correlation was used to assess the direction, strength and statistical significance of linear correlation between 2 quantitative variables, one of which being non-normally distributed. data analysis was conducted by application of spss program version 21. results table (1) represents caries experience (d1-4mfs) according to categories of stressful life events. the highest mean rank value was among accumulative stress category followed by more stress category and less mean rank value was among less stress category with statistically highly significant difference (p< 0.001); the same picture was obtained for (ds) fraction. mean rank values of ms component not significantly differs among the three groups of scale with lower mean rank among less stress group of students and higher for more stress group. for fs component, the accumulative stress group has mean rank value higher than other two groups followed by less stress group then the more stress group value. however, all these differences were not significant (p> 0.05). table (2) illustrates the grades of caries severity (d1-4) among study groups. the mean rank of all grades of lesion severity were higher among students with accumulative stress category of scale with no significant difference (p> 0.05) except the result of d2 since it shows higher mean rank among the students with more stress with statistically significant difference. table (3) demonstrated mean rank values of salivary constituents among students according to stressful life events scale (sle). mean values of total protein were more among the students in accumulative stress category, followed by more stress category and least values for less category. moreover, the same result was found for il-6, while for salivary cortisol the opposite result was noticed; regarding salivary flow rate, mean rank values differ slightly among the students in all categories of (sle) scale, with higher mean rank values among the students with accumulative stress category, followed by more stress and less stress respectively, however, all these differences were statistically not significant (p> 0.05). table (4) demonstrated the correlation coefficient between salivary flow rate and caries experience according to the categories of (sle) scale. dmfs in addition to caries severity (ds) represented by grades of lesion severity (d1,d2,d3,d4) were weak and positive correlated with flow rate among the students of less stress category, however all these correlations were not significant (p> 0.05) except for (dmfs, ds), it was significant; while among the more stress category negative correlations were noticed between flow rate and d1, d2, ds, and dmfs with statistically significant. the opposite result was noticed concerning d3 and d4 as a weak j bagh college dentistry vol. 29(1), march 2017 stressful life events pedodontics, orthodontics and preventive dentistry 142 positive not significant correlation with flow rate (p> 0.05). concerning the accumulative stress category, weak negative and not significant correlations for d2, d3 and ds with flow rate except it was significant for d1, while for d4 and dmfs, positive weak correlations were found. however all these correlations were found be not significant (p> 0.05). table (5) illustrates the correlation coefficient between caries experience (ds, dmfs) and salivary constituents according to categories of (sle) scale. results revealed weak negative not significant correlation between salivary total protein and (dmfs) for all categories, while for (ds), the opposite results was found, all these correlations were not significant (p> 0.05). concerning salivary il-6, the correlations were negative not significant except for accumulative stress category it was weak positive, for (ds), the correlations were weak positive not significant except for less stress it was negatively correlated. regarding salivary cortisol, for all the correlations were in negative direction and significant only for (dmfs) among less stress, while for accumulative stress category it was weak positive. table (6) demonstrates the correlation coefficient between total protein and salivary constituents according to categories of (sle) scale. for less stress, correlations were weak and in positive direction except a negative correlations with il-6 was noticed with statistically not significant (p> 0.05). concerning more stress category, the direction was positive except for flow rate was in negative direction, with only highly significant correlation with il6. for accumulative stress category, the direction of correlations were positive except for cortisol it was negative, with statistically not significant (p> 0.05). discussion stress may tend to have a negative effect on immunological response of body, which represents an important example of mind body interaction that leading to an imbalance between host and microorganism which influence oral environments and subsequent development oral diseases (8,43). in this study, the experience of dental caries among accumulative stress category was significantly higher than other categories of (sle) and the increased dental caries among stressful individuals agrees with other study (3,18). this could be attributed to different bacterial levels were found under stress and relaxation conditions, which supports the concept that stress may contribute to dental caries and relaxation may have an anticariogenic effect by affecting the immune system and compromising host resistance to cariogenic bacteria by increasing salivary catecholamines and corticosteroids (23); also unhealthy emotional eating habits usually associated with stressful individual leading to frequent snacking and more intake of sugar containing diet (17,44). by impaired performance of self-care habits and neglect oral hygiene measure leading to poor oral hygiene creating favorable environment mainly for cariogenic bacteria (45). also reducing salivary secretion may greatly influence the ability of saliva to flush microorganisms (cariogenic bacteria), substrates and maintain oral cleanliness which leads to subjective oral dryness (46); even if the results of cortisol and salivary flow rate were almost equal between three categories, the decrease in salivary flow rate and increase in the cortisol level among the students of accumulative category have been occurred and return to normal level, because of this study measured chronic effects of stress events and situations before six months ago, also the effect of psychological stress on salivary cortisol concentrations was transient and gradually decreases after stressor, same results found by (47); since dental caries is a chronic disease, it is likely that there was a role for salivary constituents change in progression of disease. although the mean rank of salivary flow were found in the present study to be not significantly differ among different categories but still salivary flow rate was in significant negative correlation with (d1 and d2) and highly significant with (ds) among students with more stress, this results in line with other studies (48,49). this could be attributed to that higher the flow rate, faster the clearance, higher the buffer capacity and prevention of oral infection and dental caries (50). while among less stress category, flow rate was significant positive correlation with (ds and dmfs), this could be attributing to normal caries experience among students with less stress and adolescents in general with relatively unchanged flow rate , in addition, flow rate may have little bearing on caries activity at a specific point in time and one-time determination of salivary flow rate may not be a comprehensive evaluation of salivary flow functions (51). salivary total protein was found positively related to caries severity (ds), the same results were found in other studies (52); while other study found that total protein related negatively with dental caries experience (dmfs) (48). however, total salivary proteins may have both protective and detrimental properties. thus, salivary proteins j bagh college dentistry vol. 29(1), march 2017 stressful life events pedodontics, orthodontics and preventive dentistry 143 can be known as “double edged” swords, adhesins and agglutinins play a detrimental role by increasing the colonization of microorganisms (53). moreover, when total protein level of saliva elevated, which leads to elevated saliva viscosity and reduced saliva quantities which in turn lead to decrease salivary cleansing action of saliva (54). other explanation for the increase in caries experience with increase sle could be due to increase in salivary interlukin-6 (il-6) among students with accumulative stress category, this result in line with other study (30). cytokines are important in immunity and inflammation (55), however, it is known that proinflammatory cytokines play role in molecular mechanism connected to dental caries, but the details remain unexplained. however, il-6 correlated positively with dental caries experience (dmfs) and caries severity (ds) in accumulative and more stress category, this result was parallel with other studies (30,56). on the other hand, chronic stressful life events are risk factors for contracting depression, the pathophysiology of which is strongly associated with impairments in serotonergic (5-ht) neurotransmission (57), which is later linked to the high carbohydrate intake. salivary cortisol reported to be negatively correlated with (ds and dmfs), this result agree with other studies (58,59), while among accumulative stress (dmfs) was positive correlation, which agree with other studies (36,60); however, all these differences were not significant. the current study revealed a highly significant positive correlation between salivary total protein and il-6 among more stress and accumulative stress categories this result in line with other study (61). il-6 initiates and upregulates inflammation, triggers the release of acute phase proteins (62), however, the exact mechanism by which total salivary protein level increase in relation to il-6 in saliva was not clear, but this relation may be attributed firstly, to that salivary total protein level increase in response to psychological stress by numbers of mechanism (22,23,24). however, concerning the relations between salivary constituents, il-6 was reported to be negatively correlated with cortisol, this results in line with other study (63), which may be attributed to repeated episodes of acute or chronic stress can cause a state of allostatic load (64). while the result of present study showed that a weak negative relation between salivary cortisol and total protein this in line with other studies (23,58), this could be attributed to high catecholamine levels are associated with stress, which can be induced from psychological reactions or environmental stressors, which is in turn effects on saliva secretion by significantly reduces the total protein and α-amylase concentration (65). moreover, salivary cortisol and total protein α-amylase changes are independent to each other. references 1honkala, david, sergei. dental caries and stress among south africans political refugees. quintessence international academic journal aug1992; 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20:40-48. 64mcewen s. allostasis and allostatic load: implications for nuerpsychopharmacology. nueropsychopharmachology 2000; 22:108-124. 65nederfors t, dahlof c. effects of the betaadrenoceptor antagonists atenolol and propranolol on human whole saliva flow rate and composition. arch oral biol 1992; 37:579-584. j bagh college dentistry vol. 29(1), march 2017 stressful life events pedodontics, orthodontics and preventive dentistry 146 table (1): caries experience (dmfs) and its components (ds, ms, fs) (median, mean rank) according to categories of stressful life events scale. ** highly significant p≤ 0.01 table (2): caries experience represented by grades of lesion severity (d1-d4) (median, mean rank) according to categories of stressful life events scale . *significant p ≤ 0.05 table (3): salivary constituents and flow rate (median, mean rank) according to categories of stressful life events scale. stressful life events scale categories statistical differences low level stress more stress accumulative stress no median mean rank no median mean rank no median mean rank chivalue p total protein (mg/dl) 20 52.84 27.6 20 55.29 29.8 20 64.6 34.5 1.640 0.44 il-6 (pg/ml) 4.635 29.3 4.45 29.6 5.18 33.8 1.048 0.59 cortisol (ng/ml) 2.880 31.6 2.74 30.5 2.74 29.2 0.202 0.90 flow rate (ml/min) 0.84 30.2 0.9 30.5 0.83 30.8 0.013 0.99 stressful life events scale categories statistical differences low level stress more stress accumulative stress no median mean rank no median mean rank no median mean rank chivalue p ds 87 8 118.9 143 10 158.3 70 11 173.8 17.85 p<0.001** ms 0 146.0 0 153.0 0 150.9 1.353 0.51 fs 0 155.6 0 144.4 0 156.5 2.021 0.36 dmfs 10 123.4 12 155.6 13 173.7 14.03 p<0.001** stressful life events scale categories statistical differences low level stress more stress accumulative stress no median mean rank no median mean rank no median mean rank chivalue p d1 87 3 144.8 143 3 152.8 70 3.5 153.0 0.536 0.76 d2 3 132.4 4 160.5 3 152.5 5.832 0.05* d3 1 140.4 1 152.9 1 158.2 1.959 0.38 d4 0 141.0 0 150.7 0 161.8 2.741 0.25 j bagh college dentistry vol. 29(1), march 2017 stressful life events pedodontics, orthodontics and preventive dentistry 147 table (4): correlation coefficient of salivary flow rate with caries experience (dmfs and ds) and grades of lesion severity according to categories of stressful life events scale . **highly significant p ≤ 0.01 *significant p ≤ 0.05 table (5): correlation coefficient between caries experience (dmfs, ds) and salivary constituents according to categories of stressful life events scale. *significant p ≤ 0.05 table (6): correlation coefficient between salivary total protein and salivary constituents according to categories of stressful life events scale . **highly significant p ≤ 0.01 (1) m.sc. student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assist. professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (3) assist. professor, director of psychological laboratory, psychological research center, ministry of higher education and scientific research. الخالصه بب خلل وعدم انتظام في التوازن ألخلفية : تعرف الضغوط على انها تفاعل وردود فعل الجسم للقوى ذات طبيعة مؤذية واإلصابات وأي حاله غير طبيعيه شاذة تميل الى ان تس بها الشخص. وهكذا, فان هذه الضغوطات هي عبارة عن اي الفسيولوجي الطبيعي للجسم, وتوصف هذه الضغوط على انها شعور اوعواطف سلبيه و ردود فعل لتجارب غير سارة مر الى االن التوجد دراسة عراقية سابقة بحثت احداث جسديه او اجتماعيه او نفسيه او المحفزات التي تسبب تفاعل واستجابة الجسم, والتي لها اثار ضاره على الصحه العامه وصحة الفم. ان في اللعاب لدى طلبة المدارس الثانوية، ولهذا السبب صممت هذه الدراسة. 6ي لبروتين الكلي و الكورتيزول و البين ابيضاضنان وابتسوس االس احداث الحياة الضاغطة وعالقتها وكيمائيه للعاب.ائص الفيزياهداف هذه الدراسة كانت لتقييم شدة تسوس االسنان بين الطالب الذين ينتمون الى فئات مختلفة من احداث الحياة الضاغطة وعالقتها بالخص صنفت مدرسة في الكرخ األولى / بغداد. 73عام، الذين تم اختيارهم عشوائيا من 71-71طالب من الذكور فقط الذين تتراوح أعمارهم بين 033طرق : تتكون العينة الكلية من المواد الطالب وفق مقياس احداث الحياة الضاغطة )ضغوط قليلة ضغوط متزايدة، الضغوط التراكمية(. تم إجمالي العينة إلى ثالث فئات اعتمادا على عدد احداث الحياة الضاغطة التي مر بها طالبا استنادا الى فئات مقياس االحداث الضاغطة. تم تشخيص وتسجيل تسوس االسنان باستخدام 03طالب وصنفت الى ثالث فئات كل فئه من 63اخذ عينه فرعيه عشوائيا تتألف من طالبا, ثم تحليلها لقياس معدل 63. تم جمع عينات من اللعاب المحفز من muhlemann, 1976)) معياروفقا ل mfs4-1(dسنان المفقودة والمعالجة والمتسوسه )مؤشر سطوح اال . 07النسخه spssحليل جميع البيانات باستخدام برنامج و الكورتيزول و البروتين الكلي(. وتم ت 6جريان اللعاب و وكيمائيا ايضا لتحديد التراكيز اللعابيه لكل من )البين ابيضاضي كانت بين الطالب من فئة الضغوط المتراكمة من مقياس احداث الحياة الضاغطة, ويليها الطالب من فئة الضغوط المتزايدة, dmfs)النتائج : سجلت النتائج اعلى قيمه للرتب الوسطيه ) لى بين طالب فئة عاما في ما يخص شدة تسوس األسنان كانت ا (p< 0.01).فئة الضغوط القليله مع وجود اختالفات معنوية عالي وكانت ادنى قيمه للرتب الوسطيه للطالب من اما بالنسبة لدرجات شدة تسوس األسنان لجميع درجات (p< 0.01).الضغوط المتراكمة ثم الضغوط المتزايدة ثم الضغوط القليله على التوالي مع وجود اختالفات معنوية عاليه . وأظهرت (p< 0.05)فقط ظهرت بوجود اختالف معنوي d2)التسوس كانت اعلى قيم للرتب الوسطيه لفئة الضغوط المتراكمة مع عدم وجود اختالفات معنوية ماعدا فيما يتعلق ) كانت بين طالب من فئة الضغوط المتراكمة, يليها طالب فئة الضغوط المتزايدة, وأخيرا فئة الضغوط القليله. اما 6ن ابيضاضي بيانات التحاليل اللعابيه اعلى قيم للبروتين الكلي و البي ( لجميع فئات dmfsن التراكمي )الكورتيزول اللعابي فقط اظهر صوره مغايرة لذالك مع عدم وجود اختالفات معنوية. وظهرت المكونات اللعابيه عالقة عكسية مع تسوس االسنا والكورتيزول كانت عالقة موجبه لفئة الضغوط المتراكمة مع عدم وجود اختالفات معنوية. 6مقياس االحداث الضاغطة باستثناء البين ابيضاضي باإلضافة إلى االخالل في المستويات الطبيعيه ومن ضمنها تسوس االسنانأن احداث الحياة الضاغطة لها تأثير ضار كبير على صحة الفم واألسنان دراسةنتائج كشفت االستنتاج : للمكونات اللعابيه. stressful life events scale categories low level stress more stress accumulative stress r p r p r p 1d 0.30 0.170 -0.43 0.050* -0.48 0.03* 2d 0.08 0.70 -0.54 0.016* -0.009 0.97 3d 0.28 0.210 0.005 0.980 -0.13 0.58 4d 0.26 0.240 0.12 0.620 0.04 0.87 ds 0.51 0.015* -0.67 0.001** -0.39 0.10 dmfs 0.49 0.019* -0.19 0.420 0.25 0.30 stressful life events scale categories low level stress more stress accumulative stress r p r p r p total protein ds 0.02 0.92 0.11 0.65 0.03 0.90 dmfs -0.12 0.58 -0.17 0.47 -0.12 0.61 il-6 ds -0.05 0.81 0.20 0.39 0.06 0.79 dmfs -0.09 0.68 -0.19 0.43 0.05 0.83 cortisol ds -0.21 0.33 -0.06 0.80 -0.30 0.21 dmfs -0.40 0.05* -0.05 0.82 0.08 0.73 stressful life events scale categories less stress more stress accumulative stress r p r p r p il-6 (pg/ml) -0.13 0.55 0.64 0.003** 0.30 0.21 cortisol (ng/ml) 0.08 0.71 0.31 0.19 -0.05 0.81 flow rate (ml/min) 0.15 0.49 -0.24 0.31 0.30 0.21 ma'an.doc j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 54 estimation of the bennett mandibular immediate side shift in iraqi full mouth rehabilitation patients (an in vivo study) ma'an rasheed zakaria, b.d.s., m.s., ph.d. (1) abstract background: controversy exists concerning the presence and amount of the bennett mandibular immediate side shift among patients and whether it is necessary to accommodate for it in adjustable articulators. the aim of this study was to register and calculate the amount of any immediate side shift (iss) present in patients requiring full mouth rehabilitation. materials and methods: 3dimensional condylar movements of 50 iraqi tmd-free patients were recorded using a stereographic fully adjustable articulator system during protrusion, left and right eccentric mandibular movements. protrusive angles of each patient were verified to figure out the suitable fossa analog for each case. the thickness of each right and left premade fossa analog selected was measured with a vernier caliper and was tightly secured in the articulator fossa compartment. functionally-generated path recordings were performed using custom-made intraoral clutches. bennett isss, verified by the stereographic system in the molded fossae, were measured using the vernier caliper. the final right and left isss were estimated by subtracting the thickness of the blank fossa analog from that of the molded one. the final isss were recorded and statistically compared. results: stereographic recordings of eccentric mandibular movements revealed isss within all patients involved in this study. the isss varied among the patients and bilaterally within them. their average values ranged between 0.80 mm for females and 1.68 mm for males, showing significant statistical differences between them but with no relevancy to age advancement. mean values of isss of males' and females' mandibular left joints were more than those recorded by their right joints. conclusion: verifying the mandibular iss in the molded fossae is an essential step to efficiently rehabilitate full mouth cases; thus it would be helpful to use a fully adjustable articulator system to restore complicated cases since very minor intraoral occlusal adjustments might be required for the finished restorations prior to the final cementation. key words: bennett immediate side shift, fossa analog, rehabilitation. (j bagh coll dentistry 2014; 26(4):54-62). introduction the bennett immediate side shift (iss), or transtrusion of the mandible, is defined as "a thrust of the mandible in a generally horizontal direction"; it is regulated by the anatomic configuration of the glenoid fossa or capsular ligament on the nonworking side of the skull and it is activated by muscle action during mandibular lateral excursive movements (1). the iss has been considered the most important factor in determining pos-terior fossa depth and width and the contour of the palatal cavities of the maxillary anterior teeth. the greater the extent of the iss, the more palatal concavity should be provided in the anterior teeth to permit their harmonious functioning without locking in the posterior occlusion (2,3). about 80% of the adult population exhibits iss to some degree. it can occur unilaterally or bilaterally, and may differ in the amount and degree of angulation from one side of the skull to the other. when present, iss occurs when the nonworking condyle moves from its centric position in the fossa during a lateral excursive movement of the mandible. the condyle moves medially against the medial and superior walls of (1)retired professor. department of conservative dentistry. college of dentistry, university of baghdad the fossa (mediotrusion of the non-working condyle). the degree and amount of the movement is determined by the shape of the fossa, the looseness of the capsular liga-ment, and contraction of the muscles, primarily the pterygoids (4). for this reason, it's extremely important that the articulating surfaces be in strict harmony with this side shift. any discrepancy in this harmony could result in the most destructive lateral forces encountered in a mal-articulation (5). side shift can vary in the amount of the total horizontal movement anywhere from 0.2 mm to more than 2.5 mm. beyond this point the condyle moves forward, downward, and inward against the medial and superior walls of the fossa (1). because the iss influences the horizontal and vertical elements of occlusion, it must be recognized and taken care of during the diagnosis and treatment planning stage of patients having major restorative procedures performed, and sometimes for occlusal corrections by selective grinding. if the side shift is ignored, the restorations may end up with an occlusal pattern that does not function with that movement, and may result in built-in occlusal interferences leading to occlusal disharmony (6). the shape of the condyle would directly affect the nature of the bennett shift of the mandible. j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 55 investigating the shapes of the frontal projection of thousands of mandibular condyles revealed that a subject with an angular condyle functioning in an angular fossa would move his mandible inferiorly to a noticeable degree when making a lateral shift, whereas a person with a flat condyle would not necessarily drop inferiorly at all during the lateral side shift (7). using a pantograph, the iss is measured on the horizontal plane orbiting path record and is expressed in units of tenths of a millimeter. this value is almost always less than 2 mm (8). it was reported that although the pantograph has been extensively used in research and clinical practice, the value of the programmed articulator would only be realized if the transfer of graphic information to the articulator was accurate. in a study, it was found that with experienced dentists, the error in iss following on pantographic tracing was 0.16 mm while it reached 0.40 mm with the inexperienced dentists. such errors were rated significant in top wall articulator settings which would greatly affect the occlusal configuration of fixed restorations. the authors' explanation for that difference was attributed to the relative magnification of the graphic tracings in which the scribed lines of the iss are usually short and appear sensitive to the dentists' experience (9). stereographic techniques have a decided advantage in the use of the 3-dimensional recordings (functionally gene-rated path). all border pathways can be programmed into the condylar guidance, including protrusive-lateral movements. the instrument can be used in combination with customized anterior guidance procedures (10). controversy exists concerning the complexity of the articulator to accurately simulate mandibular movements. it was estimated that restorations constructed with fully adjustable articulators require 5% intraoral adjustment whereas those made using semi-adjustable articulators would require 50% and restorations made with simple hinge articulators would require 95% since using them had led to occlusal discrepancies in the final restorations which have to be corrected in the mouth in addition to being a time-consuming procedure (11). it was concluded that it should be realized that iss cannot be simulated by slot track semiadjustable articulators and significant errors in cusp positions and groove orientation of posterior teeth may result (12). most semi-adjustable articulators lack adjustments for the iss and inter-condylar distance (icd) besides that no provision for motion analog curved path-ways is present. limitations are inherent in these articulators because of the inability to accurately duplicate the posterior determinants of occlusion. it has been reported that in order to minimize the errors of straight-line semi-adjustable articulators in the horizontal plane, additional clearance should be made distal to the occlusal groove on mandibular molar teeth (13). the use of complete gnathological instruments (fully adjustable articulators) for patients having bucco-lingual wear facets on the posterior teeth with rounded central fossae has been stressed on since most adult participants possessed them. lateral eccentric prematurities were rated as one basis for occlusal pathoses (14). patients with excessive bennett movement and little or no anterior guidance present the greatest challenge in occlusal rehabilitation procedures because the cusp movement pathways of their posterior teeth are very shallow and the elimination of eccentric interferences can be very difficult. the completely adjustable articulators would be most helpful for these patients (15). the importance of estimating the iss during dental restorative therapy especially in extensive occlusal rehabilitation cases has been stressed since the incorrect iss measurement can cause occlusal error which occurs because the iss takes place early in mandibular laterotrusion, producing lateral movement of the posterior teeth before disocclusion has occurred. if the fossae width of teeth don't accommodate for the lateral motion of opposing cusps, occlusal deflective contacts on facio-lingual cusp inclines will result (3). the tmj deluxe fully adjustable articulator system provides for fossa molding of the patient's fossae, unlike the slot-track, straight-line path semiadjustable articulators (15). a stereographic articulator has been considered one of the simplest "fully adjustable" instruments to use for full mouth rehabilitation cases and has been also ranked an excellent articulator for fabricating dentures. the intraoral clutches are stabilized by the central bearing point and all recordings are made intraorally within the central area of the bases which is an advantage over pantographic devices that frequently have a tendency to tilt the denture base with the weight of the external appendages in addition to the difficulty and time-consumed in attempting to set the fully adjustable articulator according to the pantographic tracings (16). in addition, it has been noted that electronic pantographs and electronic axio-graphs are not within the reach of the general practitioners besides that they are of high price values and are limited to teaching and research institutes (17). j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 56 it is worthy to mention that careful diagnosis, thorough treatment plans, and meticulous buildup of full mouth rehabilitation cases can avoid creating tmds specially when legal claims concerning tmds have been increased over the years, a fact which necessitates that evidencebased knowledge in the field of tmd diagnosis and treatment must be fulfilled (18). materials and methods fifty adult patients (25 females and 25 males) aged 30 to 65 years participated in this study. they required extensive occlusal rehabilitation treatment due to either generalized loss of incisal and occlusal morphology due to attrition and faceting of teeth, extensive defective restorations, or multiple missing teeth, associated with moderate or severe ovd collapse.the patients were free from any tmds and tmj problems and were recruited from those seeking fixed prosthodontic work at the department of conservative dentistry, college of dentistry, university of baghdad. the criteria for patients' selection concentrated on the status of being healthy with no oral pathology or history of tmj pain or dysfunction according to the multiaxial research diagnostic criteria for tmds (rdc/tmd) (19). full series of periapical x-rays and a panoramic radiograph were taken for each patient. clinical examination for each patient included masticatory muscles' palpation, maximal opening of the mouth measured from the incisal surfaces of the anterior teeth using the vernier caliper (less than 40 mm indicated muscle spasm), mandible deviation upon opening represented as a sudden jerk to one side, condyles' pain or crepitus verification during mouth opening and closing by applying anterior and superior pressure against both condyles with tips of index fingers inserted in the auditory meatus. for each patient, two sets of maxillary and mandibular irreversible hydro-colloid impressions (tropicalgin chromatic, zhermackspa, italy) were made and converted into stone casts. centric jaw relationship was made using aluwax (aluwax dental products co, michigan, usa) following dawson's technique.(16) terminal mandibular hinge axis location was performed using the tmj kinematic face-bow(tmj instrument co, inc, usa) (20). the face-bow record was transferred to the tmj deluxe model t-7 fully adjustable articulator (tmj instrument co, inc, usa), and the icd of each patient was determined and the condyle posts of the articulator were locked at the determined measurements (21). the maxillary cast of the patient was mounted on the maxillary member of the articulator then the mandibular cast was mounted on the mandibular member of the articulator according to the patient's centric jaw relationship record. extra-oral clutches construction was done following the manufacturer's instructions. the maxillary clutch was returned intraorally followed by the mandibular clutch. the clutches were checked for the studs' clearance located in the maxillary clutch when the mouth was closed. adjustments in the vertical opening were made by the central bearing screw located in the mandibular clutch. each clutch was secured on the patient's teeth with light body silicone impression material (indurent gel, zhermack spa, italy) placed inside the clutch which was transferred to the patient's mouth who was asked to bite on the mandibular clutch so that the two clutches were firmly seated. intraoral stereographic recording of mandibular border movements for each patient was carried out in the following manner. with the patient sitting in a recline position, a trial recording was made to ensure that the patient could make reproducible border movements. under the operator's guidance, three right lateral, three left lateral, and one protrusive movements were performed to constitute a recording starting from the centric position with the central bearing screw of the mandibular clutch riding on the disk at the center of the maxillary clutch, and its studs at least 1.5 mm from the mandibular clutch surface. the mandibular clutch was removed from the mouth; a mix of tmj acrylic resin (tmj instrument co, inc, usa) was placed in four patties facing each stud of the maxillary clutch (fig.1). when the resin reached its dough stage, the mandibular clutch was placed inside the mouth and the patient was directed to move the mandible into the various border movements by holding the mandible with the operator's thumb and index fingers, starting with small circles of movement from the retruded position (fig.2). figure 1: acrylic resin patties placed on mandibular clutch platform. j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 57 figure 2: intraoral stereographic recording of mandibular border movements. when the acrylic resin was set, the clutches were removed from the mouth. on the lathe wheel, one third of the border resin material of the patties was trimmed by stone wheel in a way that the cuts would be tapered away from the recorded area to avoid any contact with the maxillary clutch except its studs and central bearing screw in any intraoral movement during refining the studs' pathways. when the acrylic resin was set and the patient had completed the movements, the recording should have app-eared with four completely cleared gothic arch forms. the recorded pathways were lubricated with petroleum jelly and the clutches were reinserted in the mouth. the patient was asked to refine the recording with the cutting studs until comfortably smooth protrusive, right, and left lateral movements were made (fig.3). figure 3. stereographic clutches after completion of the 3-dimensional recording. examining the recorded gothic arch tracings on the mandibular clutch platform, pointed tracings indicated no sign of any iss (fig.4). on the other hand, the gothic arch would have a flat shape instead of pointed indicating the presence of an iss (fig.5). figure 4 and 5: the recorded gothic arch tracings on the mandibular clutch platform. with both clutches inside the patient's mouth, the patient was guided to bite in terminal hinge position, i.e. in the points of each gothic arch tracing, then a piece of soft impression compound was placed in the clutch notches and in between them. the clutches were then mounted on the tmj articulator (fig.6). figure 6: upper and lower clutches mounted on the tmj articulatorfor fossa molding. the tmj instrument manufacturing co. has created five color-coded fossa ana-logs with curved paths in 5-degree protrusive variations (28, 35, 40, 45, 50°), (fig. 7). figure 7: premade color-coded fossa analogs. in order to verify the fossa analog degree suitable for fossa molding of each full occlusal rehabilitation case, a protrusive inter-occlusal record was registered for each patient using aluwax. the mandibular cast was mounted to the maxillary cast, which was previously mounted on the upper articulator member according to the kinematic face-bow registration, using the terminal hinge centric inter-occlusal record. in order to verify the protrusive angle of each patient to figure out the exact fossa analog degree which should be used for fossa molding for that case, two square shaped transparent hard plastic protractors having a scale ranging from (0-60°) were attached to the articulator outside each of its fossa compartment in such a way that the protractor was close to the condyle stylus. the condyle pin was located at the center of the protractor in the terminal hinge position (fig.8). j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 58 figure 8: the condyle pin located at the protractor center. placing the protrusive inter-occlusal record in position between the maxillary and mandibular casts, the angle of eminentia was observed by sighting the center of the condyle pin through the transparent protractor and the protrusive angle for each patient was recorded so that the exact fossa analog suitable for that case could be selected for fossa molding. the thickness of each right and left selected premade fossa analog was measured with the vernier caliper (buffalo dental mfg co, usa) at the most posterior side of its temporal plate near its intersection with its rear wall (fig.9). figure 9: measuring the premade fossa analog. two prefabricated plastic fossa analogs selected by the above described technique were tightly secured in the tmj articulator fossa compartment. the height of contour of the condyle ball was checked to fit into the fossa box. with the incisal pin of the articulator being removed, the recording studs were checked to follow their respective paths specially the anterior studs which shouldn't leave the recorded surface. tmj resin was mixed and let to set up to dough stage then a small portion of it was placed inside each fossa box. the condyle balls were sprayed with the silicone release agent. in order to mold the articulator fossae, the index finger of each operator's hand was placed on the posterior corner of the maxillary clutch and the thumbs on its lower anterior aspect. the other fingers grasped the mandibular attached clutch on the posterior border. without touching the top member of the articulator, sufficient downward pressure was applied with the thumb and forefingers to assure continuous contact of the studs with the recording. the studs were drawn over the recordings in protrusive, right and left lateral border movements to form the fossae. several passes over the recordings were made until the resin was set (fig.10). figure 10: fossa molding on the tmj articulator. the upper member of the articulator was detached in order to examine each fossa path (fig.11). figure 11: molded fossa analog formed the stereographic technique. excess acrylic resin was trimmed especially that which extended beyond the posterior wall of the fossa so that the upper member could arc back completely. the final refined fossae were ready for immediate side shift calculation (fig.12). figure 12: pointing at the immediate side shift. . the molded fossa analogs were classified according to each patient. the bennett isss verified by the stereographic system in the molded fossae were measured using the vernier caliper with an accuracy of + 0.01 mm (fig.13). the final right and left isss were verified by j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 59 subtracting the thickness of the blank fossa analog from that of the molded one. the arithmetic mean values of all different records were computed and subjected to statistical analyses. figure 13: measuring of mandibular immediate side shift. results regarding the immediate side shift (iss), table (1) represents a higher mean average for males (1.68 mm) compared to the females (0.80 mm). table 1: descriptive statistics of the (iss) of females & males in mm. average iss groups mean sd min. max. female 0.80 0.32380 0.18 1.43 male 1.68 0.56275 0.90 2.75 total 1.24 0.63520 0.18 2.75 the anova test and student's t-test (tables2&3) revealed statistically high significant differences between the isss of malepatients compared to those of females. table 2: anova test results of the (iss). table 3: group statistics (student's t-test) results of the average (iss). the left tmjs of females (0.84 mm) and males (1.76 mm) iss group mean values were greater than the right ones (0.75 mm & 1.59 mm), while the means of males (1.68 mm) were higher than the females (0.80 mm) in general scoring a difference of 0.88 mm (table 4). mean issvalues of both sexes of left tmjs equaled to 1.30 mm while those of the right tmjs were 1.17 mm. table 4: descriptive group mean values of right & left joints iss (mm) female male right left mean right left mean 0.75 0.84 0.80 1.59 1.76 1.68 discussion in this study, the amount of iss has been found to vary among patients and bilaterally within them. the anova and student's t-tests revealed highly significant differences between the mean iss of male patients compared to those of the female patients. factors responsible for such variance in the mandibular iss could be related to the hypertension of masticatory muscles and the strain of the tmj area (22) in addition to the markedly variation of the sizes and shapes of regional muscle attachments among subjects and the different displacement patterns in specific muscles where the movements of each muscle part differs according to variations in the size and shape of insertion areas (23). average iss sos df m.s. f sig. between groups 9.654 1 9.654 45.802 0.000 hs within groups 10.117 48 0.211 total 19.770 49 average iss mean sd t-test p-value sig. female 0.80 0.32 -6.768 0.000 hs male 1.68 0.56 j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 60 the presence of the iss in all studied patients requiring full mouth rehabilitation has supported previous beliefs that the iss is a result of adaptive morpho-functional changes in the fossae due to occlusal interferences and/or other forces applied to the joints.(1) another responsible factor for the variation of iss between patients could be the stretch in the ligaments of the articular capsule of the rotating (working) condyle being a consequence of the contraction of the medial pterygoid muscle on the orbiting side resulting in medial movement of the orbiting condyle, causing the rotating condyle to move out until the slack in its articular capsule is consumed.(8) the results of this current study revealed that the mean iss value of the female patients was 0.80 mm and was 1.68mm for the males which didn't coincide with those of gibbs et al. (24) (0.40 mm) and beardet al.(25) (0.36 mm) who found no differences between the female and male subjects with an increase in the iss with age; such findings were different from the current study in which iss differences existed between the sexes and no relevancy of iss was correlated with the increase of age of the patients. on the other hand, it coincided with roads et al. (8) conclusions that the iss value is almost always less than 2.0 mm and with solnit and curnutte (1) observations that the side shift may vary from 0.2 mm to 2.5 mm condyle. bellanti and martin (26) reported that only 13% of the examined subjects demonstrated voluntary iss of more than 0.20 mm while in this study, 100% of the patients scored voluntary iss values greater than 0.20 mm.this study results also didn't go along with their findings since only 30% of the subjects demonstrated an iss of the mandible in their study. in addition, their subjects' ages ranged between 15 years to above 30 years (authors didn't mention the maximum age). on the contrary, the man-dibular iss was present in all patients included in this study. this increase in the range of iss in this study compared to other studies could be explained that possibly through the years of mastication and parafunctional habits, a remodeling of condylar form, a stretching of temporomandibular ligaments or an incoordination of muscles could have accounted for it.(25) in this study, the means of the left iss of both female and male patients (0.84 & 1.76 mm) were greater than the means of the right iss (0.75 & 1.59 mm). this finding supports the observations of turp et al. (27) who related the observed discrepancy to a functional difference of the left and right inferior heads of the lateral pterygoid muscle. other potential reasons for the observed discrepancy in the maximum lateral excur-sion are differences in the tmj anatomy, the preferred side of mastication, and occlusal (mediotrusive) interferences. (27) in this study, the mean iss values of both sexes of the left condylar side (1.30 mm) were close to dos santos and ash (28) study values (1.08 mm) but the right side iss mean values (1.17 mm) were significantly more than theirs (0.25 mm). the increased iss (due to lack of occlusion) can't be assumed which may indicate that the iss is more constant throughout life than previously believed and therefore, loss of occlusion as a suspected cause of variance in iss was not substantiated (29). applying the functionally genera-ted path technique indicated that no intraoral occlusal adjustment would be necessary for the finished restorations since a precise reproduction of the dynamic jaw motion had led this system to possess the potential to improve the accuracy of the prosthetic teeth occlusion.(30) it was concluded that for patients with less than 0.75 mm iss, chair side correction of the errors in the horizontal plane is possible, but for patients with an iss greater than 2 mm, the error is clinically unacceptable and difficult to correct. for such reasons, articulators should have mech-anical equivalents to represent border movements because patients function to border positions during mastication and the need for incorporating iss into articulator move-ments is essential (30). bellanti and martin (26) concluded that some consideration must be given to the necessity of using an articulator system that would reproduce the occurrence of iss within patients. they further reported that the presence of mandibular iss increases the potential for working and nonworking side tooth contacts which poses a problem for the restorative dentist because of the difficulty of controlling occlusal contacts in dental restorations. the findings of this study strongly agree with such remarks. finally, the results of this study strongly support the importance of using a fully adjustable articulator system which can precisely record different mandibular border movements in restoring full mouth rehabilitation cases, especially when all the four quadrants are involved with or without abnormal deviation of the mandible so that crowns which a dentist has to grind excessively on, teeth that feel high, bridges that don't fit, can be avoided (31). this became obvious in the finished full mouth rehabilitation cases of the involved patients in this study, since very minor intraoral occlusal adjustments were needed for the finished restorations. j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 61 the conclusions that cab be drawn from this study are: 1. bennett mandibular iss varied among patients and bilaterally within them and significant differences were present between the mean values of males and those of females with no relevancy to the increase in age. 2. since all patients requiring full mouth rehabilitation treatment exhibited isss in this study, the necessity of an articulator which incorporates mechanical equivalents to represent mandibular border movements specially the iss is one that can serve clinical purposes satisfactorily specially that minor intraoral occlusal adjustments were required for the finished restorations. 3. verifying the mandibular iss in the molded fossae is an important step to efficiently construct complicated prosthodontic cases. references 1. solnit a, curnutte dc. occlusal correction, principles and practice. 2nd ed. chicago: quintessence pub co.; 1988. pp. 67-8. 2. lundeen tf, mendoza f. comparison of two methods for measurement of immediate benn-ett shift. j prosthet dent 1984; 51:243-6. 3. brose mo, tanquist ra. the influence of ant-erior coupling on mandibular movements. j prosthet dent 1987; 67(3): 345-53. 4. okano n, baba k, akishige s, ohyama t. the influence of altered occlusal guidance on condylar displacement. j oral rehabil 2002; 29(11):1091-8. 5. lucia vo. modern gnathological concepts-updated, 2nd ed. chicago: quintessence pub co.; 1983. p. 262. 6. celar ag, tamaki k. accuracy of recording horizontal condylar inclination and bennett angle with the cadiax compact. j oral rehabil 2002; 29(11):1076-81. 7. yale sh, allison bd, hauptfuehrer jd. an epidemiological assessment of mandibular condyle morphology. oral surg 1966; 21:169-77. 8. rhoads je, rudd kd, morrow rm. dental laboratory procedures. fixed partial dentures, vol.two. st. louis: the cv mosby co.; 1986. p.147. 9. curtis da, sorensen ja. errors incurved in programming a fully adjustable articulator with a pantograph. jprosthet dent 1986; 55(4):427-9. 10. starcke en. the history of articulators. scribing articulators. those with functionally generated custom guide controls. part iii. j prosthodont 2005; 14(3):198-207. 11. clayton ja, kotowicz we, meyers ga. graphic recording of mandibular movements.research criteria. j prosthet dent 1971; 25:28798. 12. taylor td, huber lr, aquilino sa. analysis of the lateral condylar adjustment of nonarcon semiadjustable articulators. j prosthet dent 1985; 54(1):140-3. 13. wachtel hc, curtis da. limitations of semiadjustable articulators. part i: straight line articulators without setting for immediate side shift. j prosthet dent 1987; 58(4): 438-42. 14. hart jk, sakumura js. mandibular lateral side-shift and the need for gnathologic instrumenttation. j prosthet dent 1985; 54(3):415-20. 15. rosenstiel sf, land mf, fujimoto j. contem-porary fixed prosthodontics, 4th ed. st. louis: the cv mosby co.; 2006. pp. 31,42,50. 16. dawson pe. evaluation, diagnosis and treatment of occlusal problems. 2nd ed. st. louis: mosby co.; 1989, pp. 42-43, 224, 226. 17. caro aj, peraire m, martinez-gomez j, anglada jm, samso j. reproducibility of lateral excursive tooth contact in a semi-adjustable articulator depending on the type of lateral guidance.j oral rehabil 2005; 32(3):174-9. 18. manfredini d, bucci mb, montagna f, guardanardini l.temporomandibular disorders assessment: medicolegal considerations in the evidence-based era. j oral rehabil 2011; 38(2):101–19. 19. garofalo jp, gatchel rj, wesley al, ellis e iii. predicting chronicity in acute temporo-mandibular joint disorders using the research diagnostic criteria. j am dent assoc 1998; 129(4):438-47. 20. zakaria mr, al-huwaizi hf, alnakkash wa.a comparison between arbitrary and kinematic mandibular hinge axis location in full mouth rehabilitation patients (an in vivo study). j baghcoll dentistry 2011; 23(4):20-3. 21. zakaria mr, al-huwaizi hf, alnakkash wa. a comparison between the arbitrary and kinematic intercondylar distances of full mouth rehabilitation patients (an in vivo study). j baghcoll dentistry 2012; 24(sp. issue 1):11-7. 22. kiyoshi k. the meaning of the occlusal splint in the infraclusion the part supporting the occlusal reconstruction. j acade gnatho occ 2004; 24(2/3): 320-6. 23. goto tk, langenbach get, korioth twp, hagiwara m, tonndorf ml, hannam ag. functional movements of putative jaw muscle insertions. anatomical record 1995; 242(2):278-88. 24. gibbs ch, suit s, benz s. masticatory movements of the jaw measured at angles of approach to the occlusal plane. j prosthet dent 1973; 30: 283-7. 25. beard cc, donaldson k, clayton ja. compa-rison of an electronic and mechanical panto-graph. part i: consistency of an electronic computerized pantograph to record anterior settings. j prosthet dent 1986; 55:570-4. 26. bellanti nd and martin kr.the significances of articulator capability. part ii: the prevalence of immediate side shift. j prosthet dent 1979; 42(3): 2556. 27. türp jc, alpaslan c, gerads t. is there a greater mandibular movement capacity towards the left? verification of an observation from 1921. j oral rehabil 2005; 32(4):242-7. 28. dos santos j, ash mm. a comparison of the equivalence of jaw and articulator movements. j prosthet dent 1988; 59(1):36-41. 29. goldenberg bs, hart jk, sakumura js. the loss of occlusion and its effect on mandibular immediate side shift. j prosthet dent 1990; 63(2):163-6. 30. nishigawa k, satsuma t, shigemoto s, bando e, nakano m, ishida o. development of a novel articulator that reproduced jaw movement with six j bagh college dentistry vol. 26(4), december 2014 estimation of the restorative dentistry 62 degree of freedom. medical engineering & physics 2007; 29(5): 615-9. 31. racich mj. orofacial pain and occlusion: is there a link? an overview of the current concepts and the clinical implications. j prosthet dent 2005; 93(2):18996. j bagh college dentistry vol. 26(1), march 2014 elevation in surface restorative dentistry 67 elevation in surface temperature of root canals obturated with different thermoplasticized gutta-percha obturation techniques-an in vitro study samer aun thyab al-shimari, b.d.s., m.sc. (1) nassr ezzulddin al-nuaimi, b.d.s., m.sc. (1) abstract background: many studies have been conducted to evaluate the effect of using a hot material in the root canal and its potential for causing damage to the tooth supporting structure. materials and methods: thirty permanent premolars were obturated with thermoplasticized gutta-percha using three different obturation techniques: soft core, thermafil, and obtura to evaluate the rise in temperature on the root surface using a multipurpose digital thermometer. results: temperature increases was significantly greater for obtura versus soft core (p<0.003), not significant for thermafil versus soft core (p<0.087), and thermafil versus obtura (p<0.125). conclusions: temperatures rise on the root surface were below the critical level and, therefore, should not cause damage to the periodontal ligament. key words: root surface temperature, thermoplasticized gutta-percha. (j bagh coll dentistry 2014; 26(1):67-70). introduction endodontic therapy aims for complete debridement of pulpal tissues, total obturation of the root canal space, resulting in an inflammatoryfree state. 1 the complexity of the root canal system is well documented with fins, lateral and accessory canals, apical deltas, and isthmuses. 2-4 for these reasons, it is difficult to shape the canals to a form that can easily be filled in all dimensions. one of the materials commonly used for root canal obturation is gutta-percha. its physical properties have made several different root-filling techniques possible. 5 many techniques have been developed for placing dental gutta-percha as an obturation material. thermoplasticized obturation techniques were introduced to improve the homogeneity and surface adaptation of guttapercha. thermafil which was introduced by johnson 6 in 1978 was one of these techniques, it involved the use of a carrier coated with a layer of gutta-percha, which, when heated, permits thermoplasticized canal obturation. this system is commercially available as thermafil endodontic obturators (tulsa dental products, tulsa, ok). thermafil obturators, with their carriers are coated with α-phase gutta-percha and become part of the final obturation. the manufacturer recommends that the carriers be heated in a special oven, the thermaprep oven (tulsa dental products), before being inserted in a canal previously lined with sealer. 7 (1) assistant lecturer, department of conservative dentistry, college of dentistry, university of baghdad. there is a similar technique of root canal obturation known as soft-core (cms-dental aps, denmark). as in the thermafil system, soft-core obturators are heated in a special heater called a softcore oven (cms-dental aps) and then introduced into the root canal to the working length. unlike the thermafil obturator, a single unit, the soft-core obturator consists of two parts: a plastic handle with a metal insertion pin, and a plastic core with gutta-percha. the metal pin is not permanently attached to the plastic core; when the obturator is introduced into the canal, the handle is twisted and then removed together with the metal pin. 8 high-temperature thermoplasticized injectable gutta-percha system (obtura ii, obtura spartan, fenton, mo) was another thermoplasticized gutta-percha obturation method in which the gutta-percha was heated to a temperature of a minimum of (160°c), once plasticized, the gutta-percha is injected through the silver needles into the prepared root canal. 9 even though tooth root tissues are poor thermal conductors 10,11 , the canal filling with heated gutta-percha may be responsible for the rise of the root outer surface temperature. 12-16 eriksson and albrektsson 17 conducted a vitalmicroscopic study on temperature threshold levels for heat-induced bone tissue injury on rabbit. they found that bone tissue heating to 47°c for 1 min caused bone remodeling and fat cell necrosis. other in vivo study by gutmann et al. 18 in a mongrel dog showed no apparent periodontal tissues destruction after the injection of hightemperature thermoplasticized gutta-percha (obtura, 160°c) into the root canal. in the study j bagh college dentistry vol. 26(1), march 2014 elevation in surface restorative dentistry 68 cited, the changes in the temperature of the external surface of the bone overlying the roots obturated with thermoplasticized gutta-percha were also recorded and the maximum temperature elevation over 60s was found to be 1.1°c. in another in vivo study, molywdas et al. 19 used two beagle dogs to assess periodontal reactions after root canal filling with the same system. the obturation with gutta-percha heated to 160°c caused an inflammatory reaction and destruction of collagen fibers in the area around the apical foramen. the alveolar founding bone, the roots of the teeth and the periodontal ligament at the side of the root surfaces remained normal. during the obturation procedure no temperature measurements were taken in the periodontal ligament or on the bone overlying the roots. the aim of this in vitro study was to measure with infrared thermography temperature changes on the outer root surfaces of maxillary and mandibular single rooted permanent premolars when obturated with thermoplasticized guttapercha (thermafil, soft core and obtura ii). materials and methods teeth collection thirty permanent premolars which were extracted for orthodontic reasons were used in this study; each tooth should have a straight single root of 10-12mm length from the cement-enamel junction to the clinical apex. the collected teeth were stored in 5% thymol solution. 20 instrumentation the crown of each tooth was sectioned at the level of the cemento-enamel junction so that the length of each root was about 10-12mm. the working length was estimated by using size 10 reamer which was inserted into each canal until it project from the apical foramen then 0.5mm was subtracted from the estimated length. after the working length estimation of each root, instrumentation was performed using protaper hand instruments, according to the manufacturer´s recommendations; instrumentation was started with size (sx) to widen the coronal orifice of the canal followed by size (s1), (s2), (f1), (f2), (f3), (f4), up to size (f5). the canals were irrigated with distil water solution before shifting from one size to another. 21 obturation the thirty prepared canals were divided randomly into three groups; the first group obturated with injectable thermoplasticized gutta-percha (obtura). obtura unit was set to the maximum temperature and the guttapercha was heated up to 199oc. a 23guage injection needle tip was inserted into the canal 3-5mm shorter than the working length as recommended by the manufacturers, then the softened material was injected into the canal until slight back pressure is felt then the needle was withdrawn slowly until the whole canal was obturated. 9 the second group obturated with thermafil obturators; a size 50 verifier was used to check the size of the canal prior to the use of the corresponding obturator. the selected cone was heated in thermaprep oven (tulsa dental products), the time required and the temperature to which the cones were heated was predetermined in the oven by the manufacturers. the warmed obturators were slowly inserted into the canals up to the working length. 7 the third group obturated using soft core obturation technique; the canals were obturated in the same manner as described in the second group except that the obturators were thermoplasticized in the soft core special oven (cms-dental aps). each one of the three groups obturated according to manufacturer’s recommendations of each system. no sealer was used during obturation of the three groups to eliminate the possible discrepancies associated with the use of different sealer coating methods with each obturation techniques. 8 in order to record the rise in temperature over the surface of the thirty root canals a multipurpose digital thermometer that uses infra-red point for measuring the changes in the temperature over the surface of any object that faces its eye. the thermometer was mounted so that the infra-red lens was perpendicular on the mesial aspect of each root 5mm higher than the root apex and at 5mm away from the root surface as recommended by the manufacturers. the rise in temperature over the root surface during and after obturation was measured; readings were taken at six different time intervals (5, 20, 30, 60,120, and 180 seconds). 22 the collected data were analyzed with nova test then lsd test. a difference was accepted as significant for p < 0.05. results the mean temperature rises, and sd recorded on the outer root surfaces during and after root canal obturation using all studied techniques are shown in figure 1.and table 1. the anova and lsd analyses indicated significantly greater temperature increases for obtura versus soft core (p<0.003), non significant temperature rise for thermafil versus soft core (p<0.087), and thermafil versus obtura (p<0.125). http://hinari-gw.who.int/whalecomwww.sciencedirect.com/whalecom0/science/article/pii/s0099239905602129#tbl1 j bagh college dentistry vol. 26(1), march 2014 elevation in surface restorative dentistry 69 figure 1. the mean temperature rises on the outer root surfaces during and after root canal obturation discussion under the circumstances of this study, obturation with thermafil (115°c) produced the maximum elevation in surface temperature (3.6°c) this rise in temperature took place after 60 seconds from the time of obturators insertion into the canal, this rise in temperature come in agreement with the findings of lipski et al 23 , they used an infrared camera to found in vitro that thermafil obturation technique produced temperature rises ranging from 2.1°c to 6.1°c with the highest rise take place within the first 10 seconds after cone insertion. on the opposite of the findings of lipski et al, in this study soft core (115°c) produced the lowest rise in surface temperature as compared to the other two obturation techniques. high temperature injectable gutta-percha (200°c) produced more rapid but lower increase of root surface temperature than thermafil obturation technique (3.2°c within 5 seconds). unlike the results of this study weller and koch who investigated, in vitro, the radicular temperatures produced by injectable thermoplasticized gutta-percha found that the injectable thermoplasticized gutta-percha when injected at 200°c produced higher increase of temperature at the radicular root surface (3.67°c). 24 it is generally accepted that a 10°c rise in temperature on the root surface, to approximately 47°c, is considered damaging . 17 at this temperature, damage to the attachment apparatus of the tooth may occur. the present investigation shows that none of the three obturation techniques produced surface temperatures up to the critical level. several factors may account for this result. first, dentine is a poor thermal conductor and its conductivity varies with its thickness at the different areas of the tooth. 25 there was an almost instantaneous decrease in the temperature of the gutta-percha as it contacted the canal wall and very little heat dissipated across the dentine to the root surface. this temperature decrease may be even more pronounced in vivo because of the fluid present in the dentinal tubules and the circulation present in the periodontal ligament. finally, there was no prolonged heating of the root by any of the obturation techniques. the study by eriksson & albrektsson in 1983 reported that it was necessary to maintain the elevated temperature of 47°c for an extended period for damage to occur. additional factors may also affect the root surface temperature. the diameter of the root canal itself or the thickness of the remaining dentine may be important. a root canal sealer was not used when obturating the tooth in this investigation. barkhordar et al in 1990 and hardie in 1987 reported that the use of a root canal sealer lowered the surface temperature approximately 1-2°c compared with obturations without a sealer. the sealer layer may act as an insulator on the dentinal wall and may help protect the surrounding tissues. the results indicate that within the design of this investigation table 1: the mean temperature rises on the outer root surfaces during and after root canal obturation. starting temp. during obturation 10sec. 20sec 30sec. 60sec. 120sec. 180sec. obtura n=10 25.46 27.72 28.71 28.61 28.51 28.11 27.56 27.13 0.66 1.02 1.15 1.11 1.02 0.77 0.66 0.90 thermafil n=10 24.48 25.30 27.15 27.52 27.78 28.10 27.70 26.92 0.74 1.25 1.83 1.87 1.88 1.49 0.91 0.85 soft core n=10 24.50 25.20 26.35 26.55 26.65 26.65 25.97 25.37 0.86 0.77 1.15 1.30 1.31 1.18 0.88 0.73 j bagh college dentistry vol. 26(1), march 2014 elevation in surface restorative dentistry 70 the temperatures on the root surface were below the critical level and therefore should not cause damage to the periodontal ligament. references 1. ingle ji, bakland lk, editors. endodontics. 5th ed. london: bc decker inc; 2002.p.109-10. 2. kirkham db. the location and incidence of accessory canals in periodontal pockets. j am dent assoc 1975; 91: 353-6. 3. dedeus qd, horizonte b. frequency, location and direction of the lateral, secondary, and accessory canals. j endod 1975; 1: 361-6. 4. rubach wc, mitchell df. periodontal disease accessory canals and pulp pathosis. j periodontol 965; 36: 34-8. 5. brayton sm, davis sr, goldman m. gutta-percha root canal fillings. oral surg oral med oral pathol 1973; 35: 226–231. 6. johnson wb. a new gutta-percha technique. j endod 1978; 4:184–8 7. tulsa dental products. thermafil endodontic obturators: detailed instructions for the use of thermafil endodontic obturators. tulsa: dental products 1991. 8. natural gp soft-core. a 3rd generation endodontic obturator: manual. dental production aps, copenhagen; 2001. 9. obtura ii. obtura u heated gutta-percha system, operator's manual costa mesa, ca, usa: texceed corporation, 1993. p. 1-22. 10. hardie e. further studies on heat generation during obturation techniques involving thermally softened gutta-percha. int endod j 1987; 20:122–127. 11. weller n, koch ka. in vitro radicular temperatures produced by injectable thermoplasticized gutta-percha. int endod j 1995; 28:86–90. 12. lee fl, van cura je, begole e. a comparison of root surface temperatures using different obturation heat sources. j endod 1998; 24:617–620. 13. anićv i, matsumoto k. dentinal heat transmission induced by a laser-softened gutta-percha obturation technique. j endod 1995; 21: 470–4. 14. lipski m. root surface temperature rises in vitro during root canal obturation with thermo-plasticized gutta-percha on a carrier or by injection. j endod 2004; 30:441–3. 15. lipski m. root surface temperature rises in vitro during root canal obturation by the continuous wave of condensation technique using system b heat source. oral surg oral med oral pathol oral radiol & endod 2005; 99: 505–10. 16. lipski m. root surface temperature rises in vitro during root canal obturation using hybrid and microseal techniques. j endod 2005; 31: 297–300. 17. eriksson ar, albrektsson t. temperature threshold levels for heat-induced bone tissue injury vitalmicroscopic study in the rabbit. j prost dent 1983; 50:101–7. 18. gutmann jl, rakusin h, powe r, bowles wh. evaluation of heat transfer during root canal obturation with thermoplasticized gutta-percha. part ii. in vivo response to heat levels generated. j endod 1987; 13: 441–8. 19. molyvdas i, zervas p, lambrianidis t, veis a. periodontal tissue reactions following root canal obturation with an injection-thermoplasticized guttapercha technique. endod dent traumatol 1989; 13: 32–7. 20. al shimari a, al-hwaizi h. in vitro study to evaluate the adaptability of three different gutta-percha obturation techniques: thermafil, system-b/obtura, and lateral condensation. a master thesis, department of conservative dentistry, collage of dentistry, university of baghdad, 2007. 21. muhsen hd, baban ls. comparison between hand and rotary protaper instrument with hand k-flexofile in preparation of curved simulated root canals. a master thesis, department of conservative dentistry, collage of dentistry, university of baghdad, 2008. 22. lipski m. root surface temperature rises during root canal obturation, in vitro, by the continuous wave of condensation technique using system b heat source. oral surg oral med oral pathol oral radiol endod 2005; 99: 505-10. 23. lipski m, deboa d, lichota d. thermal imaging for measuring the temperature of dental hard tissues. thermol int 1999; 9:160. 24. weller rn, koch ka. in vitro radicular temperatures produced by injectable thermoplasticized gutta-percha int endod j 1995; 28:86–90. 25. dollard wf, sabala cl, pelleu gb. root canal temperature during obturation with the mcspadden compactor technique. jounml of dental research. 1983; 62: 216-19. 26. barkhordar ra, goodis he, watanabe l, koumdjian j. evaluation of temperature rise on the outer surface of teeth during root canal obturation techniques. quint int 1990; 12:585–588. ban final.doc j bagh college dentistry vol. 26(2), june 2014 in vivo immunohistochemical oral diagnosis 58 in vivo immunohistochemical investigation of the effect of the topical application of growth hormone on the osseointegration of cpti implant abdul naser h. warwar, b.d.s., m. sc. (1) ban a. ghani, b.d.s., m.sc., ph.d. (2) abstract background: dental implants are a suitable option for the replacement of some or all missing teeth. the successful insertion of a biocompatible material into living tissue with little to no evidence of rejection has revolutionized medicine and dentistry. an increase in bone response was observed with local administration of growth hormone around dental implants. growth hormone may act as a bone stimulant in the placement of endosseous dental implants and enhances osseointegration. the aim of the study was to evaluate immunohistochemically the effect of the topical application of growth hormone on the osseointegration of cpti implant. materials and methods: eighty titanium screw implants were inserted in the tibia of the forty adult rabbits. growth hormone was applied on experimental implants. immunohistochemical tests were performed on the implants of both control and experimental groups for (3 days1, 2, and 6 weeks) healing intervals. results: titanium implants coated with growth hormone revealed an early bone formation, minerlization and maturation in comparison to control. immunohistochemical findings revealed positive expression for vegf in experimental implant in comparison to control one. conclusion: topical application of growth hormone may act as a bone stimulant in the placement of endosseous dental implants and enhances osseointegration. key words: growth hormone, dental implant, biochemical bone marker. (j bagh coll dentistry 2014; 26(2): 58-63). الخالصة عدم حدوث رفض لھذه الم واد ق د اح دث مع الحیة األنسجةداخل الغرس الناجح للمواد المطابقة للجسم في إن. المفقودة األسنانالغرسة السنیة ھي الطریقة المثلى لتعویض إن :المقدمة ھرم ون النم و ربم ا یعم ل كمحف ز للعظ م ف ي عملی ة إن. ھرم ون النم و ح ول الغرس ة الس نیة إض افة خاصة وق د ل وحظ زی ادة ف ي اس تجابة العظ م عن د األسنانثورة في الطب عامة وطب الھ داف الدراس ة التقی یم النس یجي والنس یجي المن اعي الكیمی ائي لت أثیر االس تخدام الموض عي لھرم ون النم و عل ى االن دماج العظم ي .ظماستبدال الغرسان السنیة وك ذلك یحف ز تكام ل ال تع .باستخدام غرسة التیتانیوم نس یجیة مناعی ة اس تخدمت فحوص ات . رس ات التجرب ة لنم و لغ ھرم ون ا إضافةتم . ناضج أرنب ألربعین) الساق(ثمانون غرسة من التیتانیوم في عظمة القصبة إدخالتم :العملالمواد و ).اسابیع 6، 2، 1ایام ، 3(ولكال المجموعتین التحكم والتجربة ، ولكل مراحل االلتئام تكیمیائیة اجریت لكافة الغرسا إظھ ارا النت ائج النس یجیة المناعی ة الكیمیائی ة أعط ت مقارن ة بمجموع ة ال تحكم تم ام ون وج التك وین العظم ي ف ي مراح ل مبك رة أظھرتالتیتانیوم المغطاة بھرمون النمو رسة غ :النتائج .في غرسات التجربة بالمقارنة لغرسات التحكم) vegf(ایجابیا عالیا لھرمونات النمو وخصوصا لعامل النمو الوعائي البطاني .ویحفز عملیة تكامل التعظم األسنانالنمو یعمل كمحفز للعظم في عملیة غرسات االستنتاج بان االستخدام الموضعي لھرمون إلىھذه الدراسة تخلص :االستنتاج .ھرمون النمو ، الغرسة السنیة ، عالمات العظم الكیمیائیة -:مفتاحیھكلمات introduction dental implants provide a unique treatment modality for the replacement lost dentition. this is accomplished by the insertion of relatively inert material (a biomaterial) into the soft and hard tissue of the jaws; thereby providing support and retention for dental prostheses, there have to be effective biological adaptability between the implant material and the tissues of the jaws (1). despite the ongoing improvement in implant characteristics, bone intrinsic potential for regeneration may be stimulated with adjuvant therapies to standard surgical procedures, as it is important to achieve the best possible implant osseointegration into the adjacent bone and to ensure therefore long-term implant stability. for this purpose various pharmacological, biological or biophysical modalities have been developed, such as bone grafting materials, pharmacological agents, growth factors and bone morphogenetic proteins (2). (1) m.sc. student. department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad growth hormone (gh) belongs to the group of growth factors. these substances have been proposed to improve and accelerate osseous healing using topical applications (3). vascular endothelial growth factor (vegf) is a signal protein produced by cells that stimulates vasculogenesis and angiogenesis. it is part of the system that restores the oxygen supply to tissues when blood circulation is inadequate (4). vascular endothelial growth factor (vegf), which is secreted by many cells including osteoblasts and osteoblast-like cells, may be intimately related to bone development and fracture healing because both intramembranous and endochondral ossifications are associated with capillary development (5). materials and methods materials commercially pure titanium (cpti) rods 3.5mm diameter, growth hormone(somatotropine 10mg/1.5ml moh/iraq). j bagh college dentistry vol. 26(2), june 2014 in vivo immunohistochemical oral diagnosis 59 vascular endothelial growth factor antibody (vegf) from abcam company usa (ab28775) mouse specific hrp/dab detection ihc kit (abcam company england (ab80436). hydrogen peroxide block. protein block. biotinylated goat anti-mouse igg. streptavidin peroxidase. dab chromogen. methods forty adult new zealand white rabbits aged (10-12 months) were used in this study. they were divided into two groups for (3 days, 1, 2, and 6weeks) healing intervals, 10 animals for each period. atraumatic surgical technique was performed to prepare one hole in each tibia, the rt side considered as experimental group (with topical application of growth hormone) and lt side as control group. animal were scarified after 3 days, 1, 2 and 6 weeks. immunohistochemical staining procedure for detection of vegf: all tissue specimens, samples and controls, were fixed in 10% neutral formalin and processed in a routine paraffin blocks. each formalin-fixed paraffin-embedded specimen had serial sections were prepared as follows: 5µm thickness sections were mounted on clean glass slides for routine haematoxylin and eosin staining (h&e), from each block of the studied sample and the control group for histo-pathological re-examination. other 4 sections of 4µm thickness were mounted on positively charged microscopic slides to obtain a greater tissue adherence for immunohistochemistry. the procedure of the ihc assay adapted by this study was carried out in accordance with the manufacturer instructions (abcam uk). results immunohistochemical finding of the of 3 days control rabbit show positive expression of vegf in marrow tissue and fat cells embedded in ground substance (figure 1). immunohistochemical localization of vegf is indicated by the brown color of marrow tissue as positive dab stain. the view shows positive staining of fat cells embedded in ground substance of the marrow tissue (experimental group) (figure2) microscopic evaluation of the bone section related to uncoated implant after one week of implantation, shows positive immunohistochemical stain for vegf localization, in osteoid tissue (figure 3). figure 2: view of implant site coated with gh in rabbit tibia shows positive dab stain for vegf include only bone marrow tissue. dab stain with counter stain hematoxylin x200. figure 1: microphotograph view shows positive expression for vegf in ground substance, b.v., bone marrow and fat cell. dab stain with counter stain hematoxylin. fc bv ob figure 3: view for positive vegf expression in osteoid tissue of one week duration, see positive osteoblast (ob). dab stain with hematoxylin counter stain, x200. j bagh college dentistry vol. 26(2), june 2014 in vivo immunohistochemical oral diagnosis 60 a view of positive immunohistochemical localization of vegf in osteoid tissue and osteoblast cells in experimental rabbit after one week (figure 4). two weeks after implantation in control rabbits, positively stained osteoblasts, and immature bone formation is detected after 2 weeks of implantation. microphotograph view of bone section in rabbit tibia shows formation of bone trabeculae with numerous scattered osteocytes and areas of marrow tissue of different sizes showing positive stain are seen (figure 5). experimental group show view of immature bone trabeculae with numerous irregularly arranged osteocytes that are positively stained. other view of implant site shows osteoid tissue, bone trabeculae in which osteocytes are embedded, osteoblasts, are positively stained (figure 6). six weeks after implantation microphotograph view in control rabbit tibia of 6weeks duration, shows large number of positively stained osteocytes that are irregularly scattered in calcified bone trabeculae (figure 7). microphotograph view of bone section in experimental rabbit tibia, in thread area of 6 weeks duration, shows mature bone with numerous osteocytes surrounding haversian canal inside bone trabeculae which are positively stained (figure 8). the results of the present study show that there was an obvious decrease in bmsc score mean values of positively stained cells for vegf, during the 3 days, 1 and 2 weeks healing intervals concerning control group, while concerning the experimental group a slight increase in vegf score at 6 weeks period, whereas the mean values of scores of vegf showed slight increase during 3days 1 and 2 weeks periods, as shown in (figure 9). ost figure 4: view for positive dab immunohistochemical stain of osteoid tissue (ost), and osteoblasts (arrows) dab stain with counter stain hematoxylin, x400. figure 5: view of positive dab stain in marrow tissue. dab stain with counter stain hematoxylin, x200. figure 6: positive staining of osteoid tissue and blood vessel endothelium(end). dab stain with counter stain hematoxylin, x400. b end os figure 7: view of implant site, shows positive staining of osteocytes (oc), and marrow tissue. (mt).dab stain with counter stain hemat-oxylin,x200. m j bagh college dentistry vol. 26(2), june 2014 in vivo immunohistochemical oral diagnosis 61 table 1 presents the conventional statistics estimators for studying and analyzing the studied (bmsc) parameter, due to different sources of variations in compact form (i.e. in general), as well as figure 10 illustrated graphically marginal mean values of the studied parameter which were distributed among different sources of variations in compact form. table 1: summary statistics of the bone cells outcomes according to different sources of variation (s.o.v.) in compact form. parameters groups mean s.e. 95% confidence interval lower bound upper bound groups control 16.22 0.47 15.27 17.17 experiment 19.66 0.47 18.71 20.60 periods 3 d. 31.81 0.67 30.47 33.15 1 wk. 24.44 0.67 23.10 25.78 2 wk. 8.50 0.67 7.16 9.84 6 wk. 7.00 0.67 5.66 8.34 markers tgf 16.81 0.47 15.86 17.76 vegf 19.06 0.47 18.11 20.01 groups experimentcontrol 40.0 30.0 20.0 10.0 0.0 19.7 16.2 periods 6 w k.2 w k.1 w k.3 d. 40.0 30.0 20.0 10.0 0.0 7.0 8.5 24.4 31.8 figure 10: bar charts of bmsc parameter's mean values distributed according to different s.o.v. in compact form oc ob figure 8: immunohistochemical localization of vegf, observed in osteoblasts (ob) at periphery of bone matrix, and in osteocytes (oc). dab stain with counter stain hematoxylin, x200 figure 9: line chart of bmsc parameter's means of score values distributed according to different s.o.v. at vegf marker 0.00 1.00 2.00 3.00 4.00 3 days 1 week 3 weeks 6 weeks vegf con. exp. 2 weeks j bagh college dentistry vol. 26(2), june 2014 in vivo immunohistochemical oral diagnosis 62 r-square coefficient indicated that the studied sources of variation are interpreted about 85.8% for the actual variations of the " bone cells parameter outcomes" changes, the assignable factor (the bone cells) had reported a highly significant effectiveness at p<0.01.in addition to that, results showed that a highly significant difference are accounted at p<0.01 due to the effective of positively stained bone cells (ob,oc,oscl),(table2). table 2: multiple comparisons by (lsd method) among all pairs of different bone cells types for (bmsc) parameter effectiveness in compact form discussion growth factors released during the inflammatory phase have the potential of attracting undifferentiated mesenchymal stem cells to the injured site; these factors are released in the injured sites by cells involved in tissue healing (6). expression of growth factors, such as tgf and vegf suggest that these may be of importance to the bone healing process (7). the vegf system has been investigated for several years, but a standardized interpretation of the immunohistochemistry (ihc) staining of the ligands and receptors has not yet been validated) 8). in the present results, vegf was positively expressed in both control and experimental groups and in different intervals periods and in different levels according to osteoblast activity in osteoid formation. at 3 days after implantation shows bone marrow tissue with stromal cells as a large number of active progenitor cells. in one week after implantation vegf shows positive expression in experimental implants. vegf is expressed in the osteoid tissue which indicated rapid woven bone formation and deposition of osteoid matrix include osteoblast and extracellular matrix this finding in agreement with mora et al (9). jung et al (10) found that, vegf was expressed more strongly within the vascular endothelial cells of the extracellular matrix, in agreement with our results, where positive localization of vegf by endothelial cells, was detected at 2 weeks. in 2 weeks after implantation vegf shows positive expression by osteoblast cells that are located at the periphery of calcified bone tissue and in osteocyte cell located within trabacule of active bone. vegf is known to promote bone turnover by stimulating chemotaxis and activity of osteoclasts and osteoblasts, cartilage remodeling and enchondralossification and thus should help to remodel the bonesubstitute into native bone (11). at 6 weeks duration, negative immunehistochemical localization for vegf marker was detected in bone, but positive expression was sho wn by osteoblast lining its surface. at six weeks period the control implant reported immature bone with implant surface while experimental implant show mature bone (12). we conclude that vegf, growth factor may contribute to the progression of osseo-integration by increasing angiogenesis, thus leading to the formation of new blood vessels from the preexisting vasculature. immunohistochemical findings revealed positive localization of vegf, by bmsc and bc with higher detected scores of mean values in experimental group (with gh, indicating that the cellular mechanisms involved improved osseointegration throughout healing intervals). references 1. triplett r, frohberg u, sykaras n, woody r. implant materials, design and surface topographies: their influence on osseointegration of dental implants. j long term eff med implants 2003; 13(6): 485-501. 2. dimitriou r, babis g. biomaterial osseointegration enhancement with biophysical stimulation. j musculoskelet neuronal interact 2007; 7(3): 253-65. 3. muñoz f, lópez-peña m, miño n, gómez-moreno g, guardia j, cutando a. topical application of melatonin and growth hormone accelerates bone healing around dental implants in dogs. clin implant dent relat res 2012; 14(2): 226-35. 4. claesson-welsh l. vegf-b taken to our hearts: specific effect of vegf-b in myocardial ischemia. arteriosclerosis, thrombosis and vascular biology 2008; 28 (9): 1575–6. 5. vico l. european cells and materials, bone formation: new perspectives 2007; 14(1): 32. 6. avila g, misch k, galindo-moreno p, wang h. implant surface treatment using biomimetic agents. implant dentistry 2009; 18: 17-26. 7. hederstierna k. methods for evaluation of early bone healing at titanium implants. institute of biomedicine department of medical biochemistry and cell biology. the sahlgrenska academy university of göteborg, sweden 2008. p. 25. 8. maae e, nielsen m, steffensen kd, jakobsen eh, jakobsen a, sørensen fb. estimation of immunohistochemical expression of vegf in ductal carcinomas of the breast. j histochem cytochem 2011; 59(8): 750-60. 9. morra m, cassinelli c, meda l, fini m, giavaresi g, giardino r. surface analysis and effects on interfacial (i) group (j) group mean diff. sig. (*) c.s ob oc -0.225 0.008 hs oscl 0.988 0.000 hs oc oscl 1.213 0.000 hs (*) hs: highly sig. at p< 0.01; s: sig. at p< 0.05; ns: non sig. at p> 0.05 j bagh college dentistry vol. 26(2), june 2014 in vivo immunohistochemical oral diagnosis 63 bone microhardness of collagen-coated titanium implants: a rabbit model. int j oral maxillofac implants 2005; 20(1): 23-30. 10. jung st, moon es, seo h-y, kim j-s, kim y-k, kim g-j. expression and significance of tgf-β isoform and vegf in osteosarcoma. orthopedic 2005; 28(8): 755-60. 11. geiger f, lorenz h, xuc w, szalay k, kasten p, claes l, augat p, richter w. vegfproducing bone marrow stromal cells (bmsc) enhance vascularization and resorption of a natural coral bone substitute. bone 2007; 41: 516–22. 12. sennerby l, thomsen p, ericson le. early tissue response to titanium inserted in rabbit cortical bone. j mat science: mat in med 1993; 4: 240 –50. dropbox 2 alf 8-14.pdf simplify your life farah final.doc j bagh college dentistry vol. 26(3), september 2014 frictional resistance orthodontics, pedodontics and preventive dentistry 118 frictional resistance of aesthetic brackets farah gh. agha, b.d.s. (1) mushriq f. al-janabi, b.d.s., m.sc. (2) abstract background: the aim of this study was to evaluate and compare the static frictional forces produced by monocrystalline ceramic (sapphire) bracket and polycrystalline ceramic bracket. materials and methods: one hindered twenty brackets/segment of archwire combinations were used, each bracket/segment of archwire combination was tested 10 times. the tests were performed in a universal testing instron machine. the data was submitted to in depended t-test. results: the independent sample t-tests showed a highly significant difference in the static frictional forces between monocrystalline ceramic (sapphire) bracket and polycrystalline ceramic bracket. conclusion: according to the biomechanical result gained from the present study, the monocrystalline ceramic (sapphire) brackets produced lower static friction level than polycrystalline ceramic bracket. keywords: frictional resistance, aesthetic brackets. (j bagh coll dentistry 2014; 26(3):118-121). introduction the demand for esthetic orthodontic appliances is increasing, and the development of materials that present acceptable esthetics for the patients and an adequate clinical performance for clinicians is needed (1). this problem has been partially solved by the introduction of esthetic brackets made of ceramic or composite, which are becoming more popular (2). the ceramic brackets available nowadays are made of alumina either in polycrystalline or monocrystalline forms (3). ceramic brackets currently represent an esthetic alternative, although their use is limited. they abrade the enamel, and fracture more easily, and they have a higher coefficient of friction, increasing resistance to sliding (4). the manufacturing process of monocrystalline brackets results in a purer structure, a smoother surface, and a considerably harder substance than the fabrication of polycrystalline brackets (5). during mechano-therapy involving movement of the bracket relative to the wire, friction at the bracket-wire interface may prevent the attainment of optimal force levels in the supporting tissues (6). therefore, a decrease in frictional resistance tends to benefit the hard and soft tissue response (7). it has been proposed that approximately 50% of the force applied to slide a tooth is used to overcome friction (8). up to 60% of the force applied for dental movement can be lost as the result of ceramic bracket resistance to sliding, leading to a longer treatment period (9,10). materials and methods for this study the materials listed in table 1 were used a 120 bracket were used divided to 60 monocrystalline ceramic brackets and 60 poly (1) m.sc. student. department of orthodontics, college of dentistry, university of baghdad (2) assistant professor. department of orthodontics, college of dentistry, university of baghdad crystalline brackets each bracket was ligated to two size of aesthetic coated archwires with three types of coating (teflon, epoxy and polymer). experimental models were especially designed for this study to assess the friction in the instron testing machine. the experimental model consisted of: 1. the bracket bonded to an acrylic block. 2. the orthodontic wire, along which the bracket could slide, fixed to the load cell of the testing machine. 3. the ligation method, consisting of coated ligature wire. preparation of the acrylic blocks by using cold-cured acrylic size of acrylic block: 1.8cm height x 1.8cm width x 3cm length. retentive holes of 2mm diameter and 2mm depth were drilled corresponding to the positions of the brackets (11). a total of 120 sections of aesthetic coated wires were prepared with length 35mm. friction generated by the experimental model consisting of upper right 1st premolar bracket fixed on the acrylic block (12,13) 0.5mm away from the end of the block, the archwire and the bracket was tested on the instron h50kt tinius olsen testing machinewith a loadcell of 10 n, and speed of 6 mm/minute (14, 15). each testing archwire was seated in the slot of the bracketand ligated with the coated ligature wire twisted until taut then untwisted a quarter turn until become slackened and to allow the archwire to slide freely, and then cut the access leaving a small part of it (15, 16).then the free end ofthe coated aesthetic tested archwire(0.014″ niti , 0.019″ x 0.025″ ss) was clamped by the load cell of instron machine and the same then the bottom of the acrylic block was clamped by the lower fixed crosshead of the instron machine (12),a computer connected to the testing machine displayed a graph showing peak force variation and recording the frictional resistance force generated on every 0.01mm distance of the tested wire in addition to the maximum frictional j bagh college dentistry vol. 26(3), september 2014 frictional resistance orthodontics, pedodontics and preventive dentistry 119 resistance force generated in newton, which then converted to grams, each of the 12 bracket/wire combinations, was tested 10 times, with new tested archwire, bracket and ligation method on each trial. for every traction test over a distance of 12mm at a speed of 6 mm/min, the maximum force needed to move the wire along the bracket (static friction) were recorded. results the independent sample t-test was used for comparison among monocrystalline ceramic brackets and polycrystalline ceramic brackets with 14”niti teflon coated archwire, and showed significant differencesp-level of < 0.05, as shown in table 2, and shown a highly significant differencesp-level of < 0.01, when coupled with 14”niti epoxy coated archwire as shown in table 3, and shown a highly significant differencesplevel of < 0.01, when coupled with 14”niti polymer coated archwire as shown in table 4,and shown a highly significant differencesp-level of < 0.01, when coupled with 19” x25” ss teflon coated archwire as shown in table 5,and shown a highly significant differencesp-level of < 0.01, when coupled with 19” x25” ss epoxy coated archwire as shown in table 6,and shown a highly significant differencesp-level of < 0.01, when coupled with 19” x25” ss epoxy coated archwire as shown in table 7. table1: materials used for this study no. materials manufacturer 1 polycrystalline ceramic bracket for the upper right 1st premolar ortho technology reflection, usa 2 monocrystallineceramic bracket for the upper right 1st premolar ortho technology reflection, usa 3 epoxy coated(14” niti,19”x 25” ss) archwire ortho technology reflection, usa 4 polymer coated(14” niti,19”x 25” ss) archwire g&h wire company, usa 5 teflon coated(14” niti,19”x 25” ss) archwire hubit, korea table 2: the independent t-test between monocrystalline and polycrystalline ceramic brackets used 14” niti teflon coated archwire groups sample size mean s.d t-test p-value monocrystalline,teflon 10 83.97 6.73 2.75 0.013* polycrystalline , teflon 10 94.98 10.75 **highly significant at level p < 0.01,* significant at level 0.05 ≥ p > 0.01 table 3: the independent t-test between monocrystalline and polycrystalline ceramic brackets used 14” niti epoxy coated archwire groups sample size mean s.d t-test p-value monocrystalline, epoxy 10 79.92 5.72 8.09 0.000** polycrystalline, epoxy 10 100.33 5.55 table 4: the independent t-test between monocrystalline and polycrystalline ceramic brackets used 14” niti polymer coated archwire table 5: the independent t-test between monocrystalline and polycrystalline ceramic brackets used 19” x25” ss teflon coated archwire groups sample size mean s.d t-test p-value monocrystalline, teflon 10 149.53 10.90 11.41 0.000** polycrystalline, teflon 10 191.81 4.32 table 6: the independent t-test between monocrystalline and polycrystalline ceramic brackets used 19” x25” ss epoxy coated archwire groups sample size mean s.d t-test p-value monocrystalline, epoxy 10 178.22 9.22 5.58 0.000** polycrystalline, epoxy 10 199.43 7.71 groups sample size mean s.d t-test p-value monocrystalline, polymer 10 64.65 8.78 6.13 0.000** polycrystalline, polymer 10 86.21 6.82 j bagh college dentistry vol. 26(3), september 2014 frictional resistance orthodontics, pedodontics and preventive dentistry 120 table 7: the independent t-test between monocrystalline and polycrystalline ceramic brackets used 19” x25” ss polymer coated archwire groups sample size mean s.d t-test p-value monocrystalline, polymer 10 132.51 7.15 6.13 0.000** polycrystalline, polymer 10 173.98 7.98 discussion the results of the present study revealed that, there was a wide range of variation in the mean values of static forces between sapphire and ceramic brackets when coupled with both 0.014″ niti and 0.019″ x 0.025″ ss coated (teflon, epoxy, polymer) aesthetic archwire, with the sapphire bracket (monocrystalline brackets) has the lowest mean value of static friction generated than ceramic brackets (polycrystalline brackets)this could be contributed to the fact that polycrystalline brackets have a higher coefficient of friction than monocrystalline ceramic brackets. this is due to their rougher and more porous surface (17).slot surfaces of polycrystalline brackets have a coarser surface texture and more prominent surface irregularities than slot surfaces of the stainless-steel or single-crystal brackets (18).higher frictional values of polycrystalline brackets could be produced by sharp and hard edges created at the intersection of the base and walls of the slot with the external surface of the bracket (19).these results fully agree with those of previous studies (2,20,21),but did not agree with (22,23), other study did not find any significant advantage of monocrystalline brackets over polycrystalline ceramic brackets with regards to their frictional characteristics (24). also this could be contributed to the round slot of monocrystalline ceramic bracket (sapphire) than sharp, rectangular slot of polycrystalline bracket (ceramic), development of ceramic brackets with round smoother slot surfaces and slot base will reduce frictional resistance (25). according to the biomechanical result gained from the present study, the monocrystalline ceramic bracket (sapphire) produced lower static friction level when coupled with all type of coated archwire (teflon, epoxy, polymer). references 1. elayyan f, silikas n, bearn d. mechanical properties of coated superelastic archwires in conventional and self-ligating orthodontic brackets. am j orthod dentofacial orthop 2010; 137(2): 213–7. 2. russell js. current products and practice aesthetic orthodontic brackets. j orthod 2005; 32(2): 146–63. 3. reicheneder ca, baumert u, gedrange t, proff p, faltermeier a, muessig d. frictional properties of aesthetic brackets. eur j orthod 2007; 29(4): 359-65. 4. ghafari j. problems associated with ceramic brackets suggest limiting use to selected teeth. angle orthod 1992; 62(2):145-52. 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(ivsl). 9. holt mh, nanda rs, duncanson mg. fracture resistance of ceramic brackets during archwire torsion. am j orthod dentofacial orthop 1991; 99(4): 287-93. 10. vaughan jl, duncanson mg, nanda rs, currier gf.relativekinetic frictional forces between sintered stainless steelbrackets and orthodontic wires.am j orthod dentofacial orthop 1995; 107(1): 20-7. 11. mohammed aa. evaluation and comparison of frictional forces generated by three different ligation methods (an in vitro study). a master thesis, college of dentistry, university of baghdad, 2010. 12. dilip s, krishnaraj r, rajasecar, duraisamy s, poornima r. a comparative study of frictional resistance of stainless steel, nickel titanium, tma, timolium and can archwire with stainless steel bracketsan in vitro study. srm university j dent sci 2010; 1(1): 63-7. 13. cunha ac, marquezan m, freitas aoa, nojima li. frictional resistance of orthodontic wires tied with 3 types of elastomeric ligatures. braz oral res 2011; 25(6): 526-30. 14. baccetti t, franchi l, camporesi m. forces in the presence of ceramic versus stainless steel brackets with unconventional vs. conventional ligatures. angle orthod 2008; 78(1): 120-4. (ivsl). 15. gandini p, orsi l, bertoncini c, massironi s, franchi l. in vitro frictional forces generated by three different ligation methods. angle orthod 2008; 78(5): 917-21. 16. jassim es. the effect of bracket ligation methods on canine retraction. a master thesis, college of dentistry, university of baghdad, 2006. 17. jena ak, duggal r, mehrotra ak. physical properties and clinical characteristics of ceramic brackets: a comprehensive review. trends biomater artif organs 2007; 20(2): 101-15. 18. gill jr. friction in sliding orthodontic mechanics in ceramic brackets, teflon-coated wires, and comparative resistances. a master thesis, college of dentistry, university of saint louis, 1989. j bagh college dentistry vol. 26(3), september 2014 frictional resistance orthodontics, pedodontics and preventive dentistry 121 19. saunders cr, kusy rp. surface topography and frictional characteristics of ceramic brackets. am j orthod dentofacial orthop 1994; 106(1):76-87. 20. franco d, spiller re, fraunhofer jav. frictional resistances using teflon-coated ligatures with various bracket-archwire combinations. angle orthod 1995; 65(1): 63-74. (ivsl). 21. khambay b, millett d, mchugh s. archwire seating forces produced by different ligation methods and their effect on frictional resistance. eur j orthod 2005; 27(3): 302-8. 22. guerrero ap, guarizafilho o, tanaka o, camargo es, vieira s. evaluation of frictional forces between ceramic brackets and archwires of different alloys compared with metal brackets. braz oral res 2010; 24(1): 40-5. 23. pimentel rf, oliveira rs, chaves mg, elias cn, gravina ma. evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics. dental press j orthod 2013; 18 (1): 121-7. 24. keith o, kusy rp, whitley jq. zirconia brackets: an evaluation of morphology and coefficients of friction. am j orthod dentofac orthop 1994; 106(6): 605-14. 25. gautam p, valiathana. ceramic brackets: in search of an ideal, trends biomater artif organs 2007; 120(2): 1-6. 1 j bagh college dentistry vol. 33(1), march 2021 efficacy of arthrocentesis efficacy of arthrocentesis with injection of hyaluronic acid in the treatment of inflammatory-degenerative disease of temporomandibular joint enas abdulsattar abdulmaged (1), thair abdul lateef (2) https://doi.org/10.26477/jbcd.v33i1.2920 abstract background:temporomandibular joint (tmj) problems refer to a group of heterogeneous pain and dysfunction conditions involving the mastication, reducing life quality of the patients. arthrocentesis is a simple and less invasive surgical method for the treatment of inflammatory-degenerative disease than other conservative procedures and better than arthroscope. this clinical study aimed at evaluating the benefit of arthrocentesis with injection of hyaluronic acid in the management of inflammatory-degenerative disease of the tmj. material and methods: eighty consecutive patients were enrolled in this study with pain symptoms of tmj, insufficient masticatory efficiency during function and limitation of mouth opening; they were assessed with clinical examination and approved with computed tomography scan. arthrocentesis was done by inserting 18 gauge needles in the upper joint compartment, lavage by normal saline solution and at the end of the procedure 1ml of hyaluronic acid (ha) was injected. intensity of the tmj pain and masticatory efficiency was analyzed by visual analog scale (vas), maximum mouth opening (mmo) was assessed by a ruler. all the assessed parameters were measured before the procedure then 1 and 4 months later. results: during 5 months follow-up, comparison of the obtained results showed reduction in pain at chewing and rest 87.5%, improvement in mouth opening 100% and significant improvement in masticatory efficiency 87.5% of patients. conclusion: the procedure of arthrocentesis with sodium hyaluronate injection, used in patients who suffered from inflammatorydegenerative disease (idd), showed therapeutic benefits, simplicity, safety, patient satisfaction, lack of significant side effects and complications. key words: arthrocentesis, inflammatory-degenerative disease, hyaluronic acid. (received: 2/1/2018, accepted: 11/2/2018) introduction temporomandibular joint disorders is an umberella term covering pain and dysfunction of tmj and represents therapeutic challenge in our maxillofacial department.(1) generally, the manegment of tmj dysfunction depends on the criteria of tmj condition and is based on the position and shape of the tmj disc which is described by dworkin and leresche. the debate among scientists continues surrounding accompanying factor in tmj.(2) all these disorders make several of suffering represented by jaw pain, mastication efficiency, limited jaw movement and tmj destruction.(3) traditional non invasive approaches were applied to manegment of tmj oa, physical therapy, occlusal splints acupuncture, pharmacological, injection of steroids and recently the injection of hyaluronic acid (ha) injection. (1) senior of oral and maxillofacial surgery in al-wasity teaching hospital. baghdad –iraq, ministry of health. (2) assistant professor in oral and maxillofacial surgery department, collage of dentistry, university of baghdad. corresponding email, drenas999@yahoo.com tmj arthrocentesis is a minimally invasive technique, less expensive and simple with low morbidity used for flushing out tmj that is done by double access to upper joint space.(4) its application enhances jaw function and achieves pain relief in patients with restricted mouth opening.(5,6). ha infiltration which is polysaccharide of the family of glycosaminoglycans becomes an attributed option for the management and reliefing symptoms in the clinical setting.(7) this leads to the progressive expansion of potential clinical indications for the use of combined technique arthrocentesis which provides expansion of joint space and washing out intra articular inflammatory mediator and carbolytes coupled by hyaluronic acid (ha) injection to enhance joint lubrication reducing joint friction and replacemrnt of synovial fluid in tmj.(8) namely, the effectiveness of joint lavage may be manifested by releasing the articular disc and breaking the adhesion and the adherence between disc surface and mandibular fossa thus increasing mouth opening.new era of utilization of hyaluronic acid in tmj disorders evolved. aim: this purpose of current study was to evaluate the outcomings of arthrocentesis combined with https://doi.org/10.26477/jbcd.v33i1.2920 mailto:drenas999@yahoo.com 2 j bagh college dentistry vol. 33(1), march 2021 efficacy of arthrocentesis injection of hyaluronic acid in the treatment of inflammatory degenerative disease of temporomandibular joint. materials and methods eighty patients were included in this study (30 males and 50 females), age ranged from 18-55 years. those patients were examined and treated in the clinic of oral and maxillofacial surgery in al-wasity teaching hospital. baghdad –iraq, ministry of health. (from november 2015 to october 2017). the inclusion criteria include: 1. the clinical signs. a. pain at rest and chewing. b. mastication efficiency. c. maximum mouth opening (mmo). 2. previous known conservative management failed to resolve symptoms. the exclusion criteria: a. patient received chemo or radiotherapy. b. patient with rheumatoid arthritis. procedure the patients seated in supine position with skin of preauricular area were prepared. a refrance line (holmlund-hellsing line) was marked, eighteen gauge needles were inserted at 45 degree angle to corresponding plane during injection until reaching point space by feeling drop in the resistance to inserted needle. at least 120 ml of 9% normal saline solution should be used to wash the joint out for optimum result during lavage. an ampoule of ha was connected to the needle in situ and 1 ml of ha (hyalgan, fida, albano, italy) was injected into space. soft diet regimin was recommended for the patient . nsaid (olfen* 100 mg, acino, swiss) once daily was prescribed for 3 days with prophylactic antibiotic augmentin 625 mg three times daily ,see figure1. follow up period predetermined variables were assessed to test the efficacy of the treatment protocol. 4 months was the period between the 1st follow-up visit (at 1 month from 1st injection procedure) and 2nd follow up visit, all the parameters for tmj functions measured with the same technique. the criteria for success was no pain vas equal to zero, mastication efficiency was eating solid hard food. *the evaluation between different follow up results was done by using mcnemar chi square test and (ftest) and the results were considered significant if p < 0.05. *the pain and mastication efficiency data assessed by vas from 0 to10. * mmo data assessed by normal mouth opening range from 35-45mm results eighty patients were included in this study, there were 50 females (62.5% and 30 males 37.5%), with a mean age 31.5 years. description and statistics of data 1. masticatory efficiency the data obtained from visual analog value scale show significant reduction in masticatory efficiency from (6.75 to 2.25) at 5month follow up with (p value < 0.01) with success rate (87.5%). pre-treatment and post-treatment data are shown in table (1). table 1 : masticatory efficiency (before and after treatment). anova post-treatment pre-treatment masticatory efficiency p-value 2nd follow-up visit (4 month) 1st follow-up visit (1 month) no. (%) no. (%) no. (%) p < 0.01 hs * total 40 (100%) improved 30 (75%) total 80 (100%) improved 40 (50%) 80(100%) mean 2.25 mean 4.45 mean 6.75 sd 0.056 sd 0.111 sd 0.168 *highly significant improvement in masticatory efficiency (p value < 0.01). 2. pain level the data optained from vas revealed significant reduction in pain at 5 months follow up. a. maximum pain at chewing in all patients maximum pain at chewing present and decrease in tendency. the pretreatment and post-treatment data are shown in table (2). 3 j bagh college dentistry vol. 33(1), march 2021 efficacy of arthrocentesis table 2: maximum pain at chewing (before and after treatment). anova post-treatment pre-treatment maximum pain at chewing p-value 2nd follow-up visit (4 month) 1st follow-up visit (1 month) no. (%) no. (%) no. (%) p<0.01 hs * total 40 (100%) improved 30 (75%) total 80 (100%) improved 40 (50%) 80(100%) mean 2.35 mean 3.53 mean 6.68 sd 0.058 sd 0.088 sd 0.167 *highly significant improvement in maximum pain at chewing ( p value <0.01 ). b. maximum pain at rest in all patients maximum pain at resting present and decrease in tendency. the data of pre-treatment and post-treatment are shown in table (3). table 3: maximum pain at rest (before and after treatment). anova post-treatment pre-treatment maximum pain at rest p-value 2nd follow-up visit (4 month) 1st follow-up visit (1 month) no. (%) no. (%) no. (%) p<0.01 hs * total 40 (100%) improved 30 (75%) total 80 (100%) improved 40 (50%) 80(100%) mean 1.99 mean 3.32 mean 5.50 sd 0.049 sd 0.083 sd 0.137 *highly significant improvement in maximum pain at rest ( p value <0.01 ). 3. maximal mouth opening initial measurement of maximum mouth opening detected 50 patients included in this study with a limited mouth opening. this study demonstrated success rate (100%) with ( p value < 0.01 ). as shown in table (4) table 4: maximum mouth opening (before and after) p-value follow up visit nd2 (3 month) follow up visit st1 (1 month) pre-treatment 0.003 p<0.01 hs* 50 50 50 no. mouth opening evaluation 40mm 36mm 32.5mm mean *highly significant improvement in mmo ( p < 0.01 value ). discussion the effectiveness of arthrocentesis procedure with ha injection in this study was based on 3 clinical parameters: masticatory efficiency, pain reduction during function and increase in mmo. many clinicians and researchers have reported uniformly positive results of patients treated with arthrocentesis. all patients in the study were suffering from limited masticatory efficiency and their score equal to 6.75 rang from 5 to 8. there is reduction in the mean of masticatory efficiency score to 4.45 ranged from 3 to 6 for all patients at 1st follow-up visit. forty patients 50% showed complete response following single injection only, while remaining 40 patients 50% need 2nd injection. the data illustrated highly significant reduction in masticatory efficiency from 6.75 to 2.25 with a p< 0.01 and a success rate of 87.5%. these results agree with studies by d. manfredini et al 8. all patients in the study were complaining from tmj pain, with a score of pain at mastication equal to 6.68 ranging from 5 to 8 and showed significant reduction in pain to 2.35 with a p< 0.01 with a success rate 87.5%. these results agree with studies done by d. manfredini et al (8). the data showed highly significant improvement in pain at rest from5.5 to1.99 with a p < 0.01 with a success rate 87.5%. these results agree with studies done by d. manfredini et al(8). the study data showed significant improvement in maximum mouth opening of patients p < 0.01, with success rate 100%. 4 j bagh college dentistry vol. 33(1), march 2021 efficacy of arthrocentesis these results agree with studies done by nitzan dw(9) with the average mean for maximum mouth opening 32.5to 40 mm with a p < 0.01. conclusion the procedure of arthrocentesis with sodium hyaluronate injection offers therapeutic benefits, simplicity, safety, patient satisfaction, lack of significant side effects and complications. references 1. american dental association: report of presidents conference on the examination, diagnosis and management of temporomandibular disorders .j am dent assoc 1988; 66:75. 2. quinn jh, bazan ng: identification of prostaglandin e2 and leukotriene b4 in the synovial fluid of painful, dysfunction temporomandibular joint. j oral maxillofac surg. 1990; 48:968. 3. guarda-nardini l, stifano m, brombin c et al. a one year series of arthrocentesis with hyaluronic acid injection for tmj osteoarthritis. oral surg med oral pathol oral radiol endod. 2007; 103:14-22. 4. santos gs, calado r, sousa ne et al. arthrocentesis procedure:using this therapeutic maneuver for tmj closed lock management: j craniofac surg. 2013; 24:1347-9. 5. nitzan dw, dolwick mf, martinez ga. temporomandibular joint arthrocentesis; a simplified method for severe, limited mouth opening. j oral maxillofac surg. 1991; 49:1163-1167. 6. nitzan dw, samson b, better h. long-term outcome of arthrocentesis for sudden-onset, persistent, severe closed lock of the temporomandibular joint. j oral maxillofac surg. 1997; 55:151-157. 7. peter a. brennan vellupillai ilankovan, arthrocentesis for tmj pain dysfunction syndrome. j oral maxillofac surg. 2006; 64:949-951. 8. manfredini d, rancitelli d, ferronato g, guarda-nardini l. arthrocentesis with or without additional drugs in temporomandibular joint inflammatory –degenerative disease: comparison of six protocol. j oral rehab. 2012; 39: 245–251. 9. nitzan dw. arthrocentesis for management of severe closed lock of the temporomandibular joint: current controversies in surgery for internal derangement of the temporomandibular joint. atlas oral maxillofac surg clin north am. 1994; 6: 245. figure 1: the manuver of arthrocentesis accompined by hyaluronic acid injection. (a) the drawn line from mid tragus of the ear to the lateral canthus of eye (holmlund-hellsing line), (b)the two needles procedure, (c)wash with normal saline with spurt of solution from the second needle during the lavage, (d)injection of 1 ml of ha. a c b d 5 j bagh college dentistry vol. 33(1), march 2021 efficacy of arthrocentesis المستخلص م واالختالل الوظيفي للنظام المضغي ,وذلك لمجموعة من االعراض المتمثلة باالامراض واضطرابات المفصل الصدغي تمثل الخلفية: بسيطة واقل عرضه لعالج مرض القرص التنسكي للمفصل الصدغي. معاناة الحياة.عملية بزل المفصل هي بتقليل لتقيم تاثير عملية بزل المفصل باستخدام مادة حامض الهيلورونيك في عالج مرض القرص التنسكي للمفصل : تستهدف هذه الدراسة الهدف الصدغي الجميع ا ثمانون مريض :والطريقة المادة يعاني حيث الدراسة خالل هذه تنظيمهم التنسكي تم واضطرابات مرض القرص اعراض من في الجزء االعلى 18,حيث تم تقيمهم سريريا وكذلك باستعمال االشعه المقطعيه وذلك باستخدام نيدل عدد اثنين قياس للمفصل الصدغي الصدغي المفصل بمقدار من الهيلورونيك حامض ,وحقن مادة النورمل سالين الع سس1,باستخدام مادة نهاية باختزال وذل ملية في ك تتم متابعتهم بعد شهر وكذلك بعد اربعة اشهر . لم واالختالل الوظيفي للنظام المضغي , جميع الحاالت االعراض المتمثله باال بنسبة : النتائج االلم اختزال مالحظة مع النتائج مقارنة تتم المتابعه من اشهر خمسة بنسبة 87,5خالل الفم فتحة في تطور %وكذلك %. 87,5%,وفي النظام المضغي بنسبة 100 مرض القرص التنكسي للمفصل عملية بزل المفصل الصدغي باستعمال حامض الهيلورونيك تستعمل لمرضى اضطرابات : ات االستنتاج الصدغي بمالحظة استفادة جميع المرضى ,وسهولة العملية ,مع غياب اي اعراض جانبية خالل العملية . بزل المفصل ,مرض القرص التنسكي للمفصل الصدغي ,مادة حامض الهيلورونيك. عمليه: الكلمات الدالة articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ intisar final.doc j bagh college dentistry vol. 26(2), june 2014 the effect of ssilanized up up restorative dentistry 18 the effect of silanized alumina nano -fillers addition on some physical and mechanical properties of heat cured polymethyl methacrylate denture base material ban saad jasim, b.d.s., m.sc. (1) intisar j. ismail, b.d.s., m.sc., ph.d. (2) abstract background: polymethyl methacrylate (pmma) is the most commonly used material in denture fabrication. the material is far from ideal in fulfilling the mechanical requirements. midline fracture; poor thermal conductivity and water sorption, are common problem in this material. the purpose of this study was to evaluate the effect of addition of surface treated aluminum oxide nano fillers on some properties of heat cured (pmma). materials and methods: in addition to controlled group of heat cured pmma the silanized (al2o3) nanoparticles was added to pmma powder by weight in three different percentages 1wt%, 2wt% and 3wt%, mixed by probe ultrasonication machine. 200 specimens were constructed and divided into 5 groups according to the test (each group consist of 40 specimens) and each group was subdivided into 4 sub-groups. the tests conducted were thermal conductivity, thermal diffusivity, transverse strength, indentation hardness (shore d), surface roughness, water sorption and solubility. the results were statistically analyzed using anova and dunntt t-test. results: a highly significant increase in transverse strength was observed with the addition of (al2o3) nanoparticles to (pmma) at the percentage of 1wt%, the value was 117.72 mpa and significant increase at 2wt%; while a significant reduction occurred in transverse strength at the percentage of 3% the value was 90.110 mpa. a significant increase in surface hardness and non significant differences in surface roughness were observed for all percentages. conclusion: the addition of al2o3 nanoparticles to acrylic resin improves the thermal properties and transverse strength of acrylic resin at the same time this addition decreases water sorption and solubility. key words: silane, alumina nanofillers, transvers strength. (j bagh coll dentistry 2014; 26(2): 18-23). introduction there have been many materials used for denture base such as polymethylmethacrylate (pmma) resin, modified pmma resin and nylon (1). the material most often used to fabricate denture base and denture teeth was pmma resin which is most commonly used material since 1930 (2). pmma is the most commonly used material due to its satisfactory mechanical and physical properties, compatibility with oral tissue, aesthetics, ease of repair and low cost (1). however, few but important disadvantages are inherent in this resin such as poor strength particularly under fatigue failure inside the mouth, high coefficient of thermal expansion that causes internal stresses to be released during the processing resulting in dimensional inaccuracy, some problems such as denture fracture and wear of the denture teeth still exist (3-6). pmma has low thermal conductivity approximately 0.2 w/m.c (7) compared with gold or cobalt alloy denture base material and this can present problems during denture processing as heat produced cannot escape , leading to a temperature rise and this may lead to porosity during fabrication . from the patient's point of view, the problem with low thermal conductivity is that the denture isolates the oral soft tissues from any sensation of temperature. this can lead to patient consuming hot drink without realizing it, which may lead to the back of the throat and possibly even the esophagus being scalded (8). in order to overcome these problems, several attempts were made to modify and improve the strength, thermal properties, and hardness of the pmma. these attempts included the addition of filler particles such as zirconia, glass fiber, alumina, tin, and copper or addition of whisker to resin (9). recently, much attention has been directed toward the incorporation inorganic nanoparticles into pmma to improve its properties. the properties of polymer nanocomposites depend on the type of incorporating nanoparticles, their size and shape, as well as the concentration and interaction with the polymer matrix (10). (1) m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor. department of prosthodontics, college of dentistry, university of baghdad. nanoparticles were undergone surface treatment with silane coupling agent and embedded into pmma (21). alumina nanoparticles were treated with 3-(methacryloyloxy) propyltrimethoxysilane (mps) to get pmma/alumina nanocomposite with improved properties over pure pmma. j bagh college dentistry vol. 26(2), june 2014 the effect of ssilanized up up restorative dentistry 19 materials and methods transverse strength test the specimens used were prepared with dimensions of (65mm x 10mm x 2.5mm) according to (11). ten specimens for each concentration plus the control will make total of (40) specimens for the measurement of transverse strength. all the specimens were immersed in distilled water on the incubator at 37°c for (48) hours before testing. test was performed using a universal instron testing machine, each specimen was positioned on the bending fixture which consists of two parallel supports (50)mm apart, the full scale was 50 kg ,and the load was applied with a cross head speed of 1mm/min by a rod placed centrally between the supports making deflection until fracture occurs. surface roughness test specimens with dimension of (65mm x 10 mm x 2.5 mm) were prepared to be used for surface roughness test. ten specimens for each group were taken to make total of (40) specimens for the measurement of surface roughness test. all specimens were immersed in distilled water at 37°c for 48 hours before being tested (11). the profilometer device (surface roughness tester) was used to study the effect of al2o3 nano fillers reinforcement on the micro geometry of the test surface . surface hardness test the specimens were prepared with dimensions of (65mm x 10mm x 2.5mm) according to the american dental association specification (11). ten specimens for each concentration plus the control will make a total of (40) specimen for the testing of surface hardness. all specimens were immersed in distilled water for (48) hours before testing (11). test was performed using durometer hardness tester (shore d hardness) according to the american dental association specification (11) which is suitable for acrylic material. the instrument consists of a blunt pointed indenter (0.8 mm in diameter) that present in a cylinder (1.6mm in diameter) .the indenter was attached to a digital scale that is graduated from 0 to 100 unit. the usual method was to press down firmly and quickly on the indenter and recorded the maximum reading as the shore d hardness, measurements were taken directly from the digital scale reading. five measurements were recorded on different areas of each specimen and an average of these five readings was recorded. thermal properties tests ten specimens were prepared for each group (total: 40 specimens). the discs were with dimensions of 40 mm in diameter and 2.5 mm in thickness and according to instrument specifications. the hot disk thermal constant analyzer can be used for measuring thermal transport properties of a large variety of materials with thermal conductivities ranging from 0.005w/m.c (evacuated powders) to 500 w/m.c (graphite). naturally the parameter heating power measuring time and radius of disk, by which experiment are controlled and must be selected with care in order to arrive at results within the given limits of accuracy. the hot disk sensor consist of an electrically conducting pattern in the shape of double spiral extend out of a thin sheet of nickel. the nickel foil was chosen because of its high and well known temperature coefficient of resistivity. the conducting pattern was supported on both sides with a thin electrically insulating material. the equipment connected to computer that is programmed for the test. by selection experiment type and setting for that type, the method will be selected automatically. the experiment was called tps (transient plane source). figure 1: instron testing machine figure 2: thermal conductivity test machine j bagh college dentistry vol. 26(2), june 2014 the effect of ssilanized up up restorative dentistry 20 water sorption and solubility test acrylic disc specimens were prepared by using plastic model with dimension of (50 mm ± 1 mm in diameter and 0.5 mm ± 0.1 mm in thickness) (11). ten specimens of each concentration make total of (40) specimens for measuring of water sorption and solubility. the specimens were dried in dissecator containing freshly dried silica gel. the discs was stored in an incubator at a 37°c ±2 °c for 24 hours after that the specimens were removed to room temperature for one hour then weighted with a digital balance within accuracy of (0.000lg). this cycle was repeated every day at the same time until a constant mass "conditioned mass” (m1) was reached which mean the weight loss from each disc not more than 0.2mg in 24 hours. the specimens then immersed in distilled water for 7 days at 37 0c ± 2 0c , after this period of time, each disc was removed from the water with tweezers and wiped for 30 seconds by clean dry hand towel, left in air for 15 second then weighted ,this value represent m2. in order to obtain the value of solubility, the discs were again reconditioned to a constant mass in the desiccators at 37°c ±2 °c as done in the first time for sorption test and the reconditioned mass was recorded as (m3). the whole group was reached to m3 within 5 days. results data were translated in to computerized database structure. statistical analyses were done by using spss version 16 (statistical package for social science). the statistical analysis includes the following: arithmetic mean and standard deviation and error, statistical tables and graphical presentations. transverse strength test table 1: transverse strength parameters mpa (n/mm2) sample mean s.d. s.e. min. max. control 97.30 3.6772 1.1628 91.2 100.8 1wt% 117. 9.2679 2.930 102 130. 2wt% 104. 7.6494 2.418 96. 115. 3wt% 90.1 6.1276 1.937 84. 98.4 from table 1 and figure 3 which plots the different means of transverse strengths across different concentrations of the added al2o3 nanoparticles show that the highest mean value appeared in 1wt% which was 117.72 mpa contrast to lowest value at 3wt% with mean of 90.110 mpa. figure 3: bar chart of means of transverse strengths thermal conductivity table 2: thermal conductivity parameters analysis (w/m.c) sample mean s.d. s.e min max control .2340 .00776 .002 .22 .24 1wt% .2398 .00522 .001 .23 .24 2wt% .2488 .00651 .002 .24 .26 3wt% .2640 .01308 .004 .24 .27 the highest mean value of thermal conductivity appeared in 3wt% group with a mean of .2640 (w/m.c) and the lowest mean was in 0wt% which was .2340(w/m.c). the four groups’ means were plotted as bar chart in figure 4. figure 4: bar chart of mean thermal conductivity thermal diffusivity test table 3: thermal diffusivity parameters analysis (mm2/sec) sample mean s.d. s.e. min max control .320 .0596 .0188 .24 .40 1wt% .336 .0833 .0263 .25 .48 2wt% .346 .1257 .0397 .03 .45 3wt% .378 .1199 .0379 .29 .58 the highest mean value appeared in 3wt% with a mean of .3784 mm2/sec and the lowest j bagh college dentistry vol. 26(2), june 2014 the effect of ssilanized up up restorative dentistry 21 mean was in 0 wt% which was .3206 mm2/sec. the four groups’ means were plotted as in figure 5. figure 5: bar chart of mean thermal diffusivity figure 6: bar charts of mean value of water sorption indentation hardness test means, standard deviations, standard error of mean value, minimum and maximum values of the hardness test of the acrylic resin were listed in table 4 for different groups of different concentrations of the silanized al2o3 nanoparticles that had been added. from table 4 the results of the test indicate that the highest mean value appeared in 3% group with a mean value of indentation resistance 87.3 and the lowest mean value was in 0% (control) which was 85.4. table 4: hardness parameters analysis sample mean s.d. s.e. min. max. control 85.400 1.26491 .40000 84.00 87. 1wt% 86.000 .66667 .21082 85.00 87. 2wt% 86.500 1.43372 .45338 85.00 89. 3wt% 87.300 .82327 .26034 86.00 88. surface roughness test table 5: descriptive data of surface roughness test result (µm) sample mean s.d. s.e. min. max. control 1.2288 .15395 .04868 1.01 1.49 1wt% 1.2289 .20661 .06533 1.01 1.64 2wt% 1.2289 .21664 .06851 .90 1.64 3wt% 1.2290 .29255 .09251 .70 1.60 the highest mean value appeared in 3wt% (mean = 1.229µm) and the lowest mean was in 0wt% (control group mean = 1.2288 µm). the four groups’ means were plotted. water sorption test table 5: descriptive data water sorption parameters (mg/cm2) sample mean s.d. s.e. min. max. control .4544 .05004 .01582 .36 .50 1wt% .3713 .05913 .01870 .30 .46 2wt% .3509 .05613 .01775 .30 .46 3wt% .2693 .05913 .01870 .20 .36 water sorption seems to decrease as the concentrations of the added al2o3 nanoparticles was increased, but for a limited extent. discussion transverse strength test the transverse strength test, one of the mechanical strength tests, is especially useful in comparing denture base materials in which a stress of this type is applied to the denture during mastication (12). the transverse (flexural) strength is a combination of compressive, tensile and shear strengths, all of which directly reflect the stiffness and resistance of a material to fracture (13,14). the addition of nonsilanized alumina nanoparticles to pmma revealed lowering the values of transverse strength. this result supported the previous reports that only adding alumina did not improve the mechanical properties of pmma (6). this could be due to the lack of interfacial bonding between the fillers and resin matrix that deteriorates mechanical properties. pisaisit et al (5) added silanized and nonsilanized alumina to j bagh college dentistry vol. 26(2), june 2014 the effect of ssilanized up up restorative dentistry 22 pmma, and by sem image they found there was a gap between nonsilanized alumina particles and resin matrix this could explain reduction in mechanical properties. the addition of silanized al2o3 nanoparticles in present study increased the values of transverse strength with 1wt% and 2% significantly compared to control groups, then the transverse strength began to decrease with 3wt% in which the value of transverse strength was less than control as in table 1 and figure 3. surface hardness test in this study, shore (d) hardness tester was used which is suitable for measuring the hardness of acrylic resin (15). hardness defined as the resistance of material to plastic deformation typically measured under an indentation load .it is a measure of the resistance to wear or scratching (14). it was found in this study that hardness value showed a non significant increase with 1wt % alumina nanoparticlesr and significant increase with 2wt%, and a highly significant increase with 3wt%.the increase in hardness was directly proportional with the increase in alumina nanoparticles content. this finding is in agreement with previous investigations (16) who concluded that reinforcing dental restorative resins and acrylic resin with ceramic particles (alumina) can produce some improvements in the surface hardness. this increase in hardness may due to inherent characteristics of the al2o3 nanoparticles. al2o3 possesses strong ionic interatomic bonding, giving rise to its desirable material characteristics, that is, hardness and strength. the most stable hexagonal alpha phase al2o3 is the strongest and stiffest of the oxide ceramics. therefore, it is expected that when al2o3 nanoparticles disperse in a matrix, they increase its hardness and strength. surface roughness test in this study profilometer device was used to estimate the effect of adding silanized alumina nanoparticles on the surface roughness of the specimens. the surface roughness of the acrylic denture base was not significantly change when different percentages of silanized nanoparticles were added. this result may be due to that the alumina nanoparticles have very small size and well dispersion, also surface roughness test is concerned with the outer surface and not the inner surface of the nanocomposite so when small percentage of nanoparticles were added to the acrylic resin only few particles involved on the surface of the specimens . the result of this study coincides with the result of abdul ameer (16) when titanium and zinc oxide powder added to the acrylic resin. water sorption test and water solubility test the absorption of water by acrylic resins is a phenomenon of considerable importance. acrylic resins absorb water slowly over a period of time, primarily because of the polar properties of the resin molecules. high equilibrium uptake of water can soften an acrylic resin because the absorbed water can act as a plasticizer of acrylic and reduce the strength of the material (17). the mechanisms which responsible for the water sorption was diffusion which was defined as the migration of one substance through a space or within a second substance in which water will penetrate acrylic resin mass and occupy a position between polymer chains (18). from the results there were highly significant decreased in the value of water sorption as the percentage of al2o3 nanoparticles increased. the reasons why al2o3 added groups exhibited significantly lower water sorption values than control group can be explained in several ways. during the polymerization process of acrylic resins, porosity or microvoids can occur among polymer chains. a high level of porosity or microvoids has been shown to facilitate fluid transport into and out of polymer by serving as sites for molecules to be sequestered and leading to enhanced solvent uptake and elution. al2o3 nanoparticles used are insoluble in water and could reduce the overall volume of the absorbing polymer. solubility represents the mass of the soluble materials from the polymers. the soluble materials present in denture base resins are initiators, plasticizers, free monomer and some pigmentation (19). there were significant decrease in the values of water solubility with the increase in percentage of silanized al2o3 nanoparticles, this decreases could be attributed to the fact that al2o3 is insoluble in water so that the addition of al2o3 to the mass of the specimens would act as additives and their presence will lead to reduction in the solubility of acrylic resin. however, the results were within the limitation of the american dental association specification (11). thermal conductivity test one of the important thermal properties of dental materials are thermal conductivity or ability to transmit heat which obtained from determining the rate at which heat can be transmitted through a given cross sectional area of the specimens of material during a given time interval (20). table 2 was showed that there were a highly significant increase in the values of thermal j bagh college dentistry vol. 26(2), june 2014 the effect of ssilanized up up restorative dentistry 23 conductivity with the addition of alumina nanoparticles . this may due to overlapping of thermal conductive nanoparticles inside the polymer matrix to bridge the insulating effect of pmma matrix. the increase in the amount of fillers make the nanoparticles approximate from each other and increase overlapping of thermal conductive particles that form pathway and permit transition of heat from one side of specimens to another side thus increasing thermal conductivity. thermal diffusivity test the thermal diffusivity describes the rate at which a body with a non uniform temperature approaches equilibrium. as in the thermal conductivity, thickness of the material is important. thermal diffusivity of acrylic resin was 0.123 mm2/sec. (20). table 4 showed that there was an increase in the value of thermal diffusivity with the increase in the percentage of alumina nanoparticles compared to the control group. an overall improvement of thermal diffusivity of pmma upon the addition the alumina nanoparticles can be attributed to the formation of thermally conducting pathway within polymer matrix. references 1. meng tr, latta ma. physical properties of four acrylic denture base resins. j contemp dent pract 2005; 6: 93-100. 2. manappallil jj. basic dental materials. 2nd ed. new delhi: 2007. p: 99-142, 346-377. 3. winkler s, monasky ge, kwok j. laboratory wear investigation of resin posterior denture teeth. j prosthet dent 1992; 67: 812-814. 4. darbar ur, huggett r, harrison a. denture fracture – a survey. br dent 1994; 176: 342-345. 5. chaijareenont p, takahashi h, nishiyama n, arcsorrnukit m. effect of different amounts of 3methacryloxypropyltrimethoxysilane on the flexural properties and wear resistance of alumina reinforced pmma. dental materials j 2012; 31(4): 623–8. 6. alhareb ao, ahmad za. effect of al2o3/zro2 reinforcement on the mechanical properties of pmma denture base. j reinf plast compos 2011; 30: 83-5. 7. mc cabe jf, walls awg: applied dental materials. 9th ed. mosby; 2008. 8. noort rv, murphy. introduction to dental material. 2nd ed. else view science limited: mosby; 2002. p. 2117. 9. messermith pb, giannelis ep. synthesis and characterization of layered silicate epoxy nanocomposites. chem mater 1994; 6: 1719-25. 10. jordan j, jacob kl, tannenbaum r, shart ma, jasiuk i. experimental trends in polymer nan composites-a review. mater sci eng 2005; 393(1) 1-11. 11. american dental association specification no. 57, 12 (1999) for denture base polymers. chicago. : council on dental materials and devices. ansi/ada. 12. craig rg. restorative dental materials. 11th ed. st louis mo: mosby; 2002. pp. 87-8. 13. jagger dc, jagger rg, allen sm, harrison a. an investigation into the transverse and impact strength of high strength denture base acrylic resins. j oral rehabil 2002; 29(3): 263-267. 14. anusavice kj. philips science of dental material. 11th ed. middle east and african ed. 2008. p. 143-166,721756. 15. unalan f, dikbas i. effects of mica and glass on surface hardness of acrylic tooth material. abstract. 16. abdul-ameer as. evaluation of changes in some properties of acrylic denture base material due to addition of radioopaque fillers. a master thesis, college of dentistry/ university of baghdad, 2006. 17. barsby mja. denture base resin with low water absorption. j dent 1992; 20: 240-44. 18. anusavice kj. philips science of dental materials. 10th ed. philadelphia: wb saunders co.; 1996. p. 211-35, 237-71. 19. craig rg, power jm. restorative dental material. 11th ed. st. louis: mosby; 2002. p.50, 185-195. 20. john pm, sakaguchi rl. craigs restorative dental materials. 13th ed. st. louis: mosby; 2012. p.16376,192-94. 21. shi j, bao y, huang z, weng z. preparation of pmma-nanomater calcium carbonate composites by in-situ emulsion polymerization. j zhejiang university sci 2004; 5(6): 709-713. type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 32 research article antibacterial and cytotoxic effect of a novel biological nano-silver fluoride synthesized from moringa oleifera leaf extract duaa jawad kadhem1, aseel haidar m.j. al haidar 2* 1. master student, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. 2. assistant professor, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. * correspondence email: dr.aseelhaider@codental.uobaghdad.edu.iq abstract: background: a great dental and biomedical interest had been paid to silver nanoparticles because of their antimicrobial activity. objective: to evaluate the antimicrobial and cytotoxic activity of a newly developed nano-silver fluoride that was synthesized from moringa oleifera leaf extract against s. mutants. material and method: the green synthesis method was used to prepare nano-silver fluoride from moringa oleifera leaf extract. the minimum inhibitory concentration and the minimum bactericidal concentration were evaluated using brain heart infusion plates, while the cytotoxicity was evaluated by the hemolytic activity. results: nanosilver fluoride had a bactericidal and bacteriostatic effect (mic was 60 ppm and mbc was 120 ppm) the diameter of the inhibition zone increased as the concentration increased. it was toxic at high concentrations and nontoxic at low concentrations. conclusion: nano-silver fluoride is a good material to be used in arresting and preventing dental caries and it is safe to be used on humans. keywords: antibacterial activity, cytotoxicity, fluoride, moringa oleifera, silver nanoparticle, streptococcus mutants. introduction while one of the most common chronic childhood diseases is dental caries, many decayed teeth remain untreated in underdeveloped countries (1). despite advances in dental care, surgical removal of the diseased dental tissue accompanied by the placement of appropriate restorative material remains the traditional method of treating dental caries. recently, traditional methods are replaced by minimally invasive methods (2,3). during the pandemic of covid-19 and as a protective measure, dental professionals prefer non-aerosol treatment, e.g. the use of topical fluoridated compositions (4). as silver has a bactericidal effect, it had been added as silver diamine fluoride (sdf) that can be used as a remineralizing agent in treating carious lesions. however, its black staining is considered a drawback that limits its use due to esthetic demand. with the development of nanotechnology, nanosilver fluoride (nsf) is proven to be effective in controlling dental caries (5). received date: 02-05-2022 accepted date: 14-06-2022 published date: 15-06-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/j bcd.v35i2.3397 https://orcid.org/0000-0002-4936-4927 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3397 https://doi.org/10.26477/jbcd.v35i2.3397 j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 33 three methods had been found for the synthesis of silver nanoparticles (agnps): physical, chemical and biological (4). synthesis using the biological method is rapid, low cost, and had less toxic effects than the other traditional methods. this method used different biological materials. green synthesis is among them that is used in the plants (6). green synthesis is defined as the production of nanoparticles using environmentally friendly materials such as bacteria, fungi, and plants (7). these appealing green strategies are free of the drawbacks that come with the traditional synthetic strategies, they are environmentally friendly (8). this new material is safe for humans to use and has excellent antimicrobial properties against mutans streptococci and lactobacilli, the main pathogens that cause dental caries. nsf is a yellow solution, this material is both environmentally friendly and inexpensive (9). the synergistic roles of both silver nanoparticles and fluoride are associated with nsf's efficacy in the prevention of dental caries (10). the antimicrobial activity of silver nanoparticles had been reported against both gram-negative and gram-positive bacteria. because of their ability to weaken the cell wall, silver nanoparticles accumulate in the bacterial membrane, causing a large increase in its permeability and cell death (10). low-concentration nps were found to be non-toxic, while high-concentration nps demonstrated more pronounced cytotoxicity (11), also some researchers discovered that the toxicity of nps was dose-dependent (12,13). in a previous study, the toxicity of antimicrobial nps was found to be strongly related to the time rather than the concentration of the antimicrobial nps (14). np toxicity is influenced by a variety of factors, including dosage, shape, particle size, distribution, time of action, interaction with other materials, and so on, according to other studies. furthermore, because of their small particle size, nps can easily enter the body and accumulate in organs, resulting in poisoning symptoms. no human cytotoxicity of nps studies has been performed to date (15,16). moringa oleifera lam (drumstick tree) belongs to the moringa genus and the moringaceae family (17). its value is related to its tender pods, flowers, and leaves, all of which are safe to consume by humans (18). the leaves, in particular, are well known for their natural healing properties and they are widely consumed (9). extracts prepared from the leaves had been found to have high natural antioxidant properties as well as some antibacterial activity against both gram-positive and gram-negative bacteria (19). a better understanding of the safety of silver nanoparticles is required to improve their therapeutic application. one of the most important procedures for determining a medication's safety is to assess its haemolytic potential when exposed to blood in vitro (20). if the red blood cell (rbc) membrane becomes compromised, haemolysis will occur. the resulting release of haemoglobin may cause adverse health events (21). this work aims to evaluate the antimicrobial activity of the nsf-mole, against s. mutans which is considered the primary pathogen involved in the development of dental caries, and their cytotoxic effect. materials and methods green synthesis of nano-silver fluoride from moringa oleifera leaf extracts j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 34 preparation of the leaf extract fresh m. oleifera plant material was collected from al-qasim green university/college of agriculture. leaf material was separated from the stems, washed with distilled water and then air-dried to remove the residual debris (22). the extract was prepared by using 5 g of a fresh leaf which was transferred to a 250 ml beaker and 100 ml of deionized water was added to the leaf. the mixture was boiled for 15 min. the extract was cooled at room temperature and then filtered using filter paper number 001(thomas baker, india) to obtain a clear extract that was used for the synthesis of silver nanoparticles (22,23). green synthesis of silver nanoparticles (ag nps) ten ml of the plant extract was added to 100 ml of 1mm agno3 (thomas baker, india). the mixture was stirred and heated using a hot plate magnetic stirrer (labinco, netherlands) for 20 min at 70 ºc. the color of the aqueous solution was changed from colorless to yellowish brown color which was an indication of the ag nps formation (23,24). at the end of the reaction, sodium fluoride (naf) (10.104 ppm) was added to improve the stability and the cariostatic efficacy of the solution and the stirring was continued overnight. the final solution nanosilver fluoride (nsf) was stored in a dark container until further use (25,5). characterization of nano-silver fluoride the silver nanoparticles were characterized by several techniques to examine their properties and to ensure the green synthesis of the nanomaterial of silver was produced: the x-ray diffraction was used for the characterization of the silver nanoparticle, uv-vis spectroscopy was performed for the nsf characterization and scanning electron microscope (sem) was used for the characterization of the morphology and the size of the nanoparticles. antimicrobial activity of nanosilver fluoride testing the sensitivity of streptococcus mutans to nanosilver fluoride to investigate the sensitivity of streptococcus mutans to nano-silver fluoride, the material was prepared in final concentrations of (25,50,75,100,125) ug/ml. chlorhexidine was a positive control and the distilled water was the negative control. agar well diffusion technique was used in this experiment on streptococcus mutans (26). procedure twenty-five ml of mueller hinton agar medium was poured into sterile petri dishes, left to cool, and solidified in sterile conditions at room temperature. then, incubated at 37◦c for 24 hrs. to get rid of the humidity and ensure the media sterility. the density of activated inoculums was adjusted to that of the standard turbidity (0.5 mcfarland standard turbidity to approximate cell density 1.5 x10^8 cfu/ml). activated streptococcus mutans inoculum was spread using a swab immersed in bacterial broth and left for 10 min at room temperature. seven wells of equal sizes and depths (6 mm) were prepared in the agar j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 35 using kork borer. each well was filled with 100μl of different concentrations prepared from nsf and the control agents. after leaving the plates at room temperature for 10 min, the plates were incubated in an incubator for 24 hrs. at 37◦c. the diameters of growth inhibition zones were measured by vernier while the absence of the inhibition zone indicated the resistance of the bacteria to the tested agent. determination of minimum bactericidal concentration (mbc) the method conducted was the preparation of the different concentrations (15,30,60,120,240) ug/ml of nsf incorporated with 10 ml bhi. a to find the minimum bactericidal concentration of the nsf (27). procedure activation of isolates. preparation of bhi.a(brain heart infusion agar) which was dispersed into screw capped bottles 10ml in each bottle and autoclaved. final concentrations of (15,30,60,120,240) ug/ml were prepared from stock and incorporated in the sterile bhi.a to get 10ml of agar and nsf. the experimental bottles were poured into sterile petri dishes and waited to become hard then inoculated by a streaking loop full of each activated bacteria. all these petri dishes were incubated for 24 hrs at 37°c including the control plate (positive control) which contained bhi.a with microbial inoculum without the addition of the nsf, and (negative control) plate which contained bhi.a with different concentrations of nfs without bacterial inoculum. the mbc was determined as the lowest concentration of nsf that killed the microorganisms. cytotoxicity of nano-silver fluoride: haemolytic activity in human erythrocytes according to the method of pinto et al. in 2012 28., human erythrocytes were obtained from blood discarded from hilla general teaching hospital. aliquots of human blood (type a, b and o) were mixed with 0.9 % (w/v) nacl at a ratio of 1:30. the samples were then centrifuged at 2,500 rpm for 5 min to obtain the erythrocytes. this procedure was repeated twice, and the sediment from the last centrifugation was re-suspended in 0.9 % nacl to a final concentration of 0.5 %. nsf was added to 3 ml of the erythrocyte suspension at various concentrations (400, 240, 120, 60, 20 and 8 ug/ml) for a final volume of 3 ml. the erythrocyte suspension was the negative control (0 % haemolysis), and the erythrocyte suspension plus 50 ul of 1 % triton x-100 (thomas baker) was a positive control (100 % haemolysis). the samples were incubated for 1 h at room temperature under slow (100 rpm) and constant agitation (incubadora shaker). the samples were then centrifuged at 2,500 rpm for 5 min, and hemolysis was quantified by spectrophotometry at 540 nm. the degree of haemolysis can be measured by spectrophotometry at a wavelength of 540 nm. the tests were performed in triplicate. the results are expressed as the arithmetic mean of three measurements, and the levels of hemolysis were determined as a percentage relative to the positive control (100 % hemolysis) statistical analysis data was recorded in excel sheets and statistical analysis was performed using spss for windows release 22 (spss inc., chicago, il, usa). anova test was used followed by games howell post hoc for the diameter of the inhibition zone among groups. for cytotoxicity, the anova test was used followed by dunnett t3 post hoc. j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 36 results characterization of silver nanoparticles synthesized by green synthesis: the xrd pattern clearly showed the main peaks at 38◦, 44◦, 64◦and 77◦, these angles belong to faced cubic center silver ion. the formation of silver nanoparticles can be visually detected after heating the aqueous solution of silver ions with moringa oleifera leaf extract. the primary solution was colorless and after the reaction of the silver ion with extract the color changed to yellowish-brown this color belonged to surface plasmon resonance (spr)of silver nanoparticle that can be detected by uvvisible spectroscopy that shows the peak centered around 430 nm and the material was synthesized by the green synthesis method which produced nanoparticles with a small diameter of less than (100 nm) (29). the result showed nanoparticles with spherical or semi-spherical forms and diameters between (19-50) nm. the particle appeared separated with slight agglomeration that occurred because of the presence of fluoride ions. antimicrobial activity of nano-silver fluoride testing the sensitivity of streptococcus mutans to nano-silver fluoride shapiro-wilk test showed normal distribution of the diameter of the inhibition zone among groups. the result showed that with the increase in the concentration of nsf-mole the diameter of the inhibition zone was increased to reach the maximum diameter (table 1). table 1: descriptive and statistical test of the diameter of inhibition zone among groups. *levene test=8.232, p value=0.000 sig concerning the nsf, results showed a statistically significant difference in the diameter of the inhibition zone for all the concentrations used except for the 75ppm with 100ppm and for 125ppm with chlorhexidine, which showed no significant difference (fig.1, table 2). groups n mean ±sd ±se minimum maximum f p value 25 10 .000 .000 .000 .000 .000 594.017 0.000 ** 50 10 .000 .000 .000 .000 .000 75 10 1.000 .115 .037 .800 1.200 100 10 1.130 .116 .037 .900 1.300 125 10 1.400 .133 .042 1.200 1.600 dw 10 .000 .000 .000 .000 .000 chx 5 1.4 0 0 1.4 1.400 j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 37 figure 1: mean diameter of inhibition zone among groups. b. determination of minimum bactericidal concentration (mbc) results of this study revealed that mbc was 120, this concentration showed no growth after reculturing on bhi –agar media, this means that (120) concentration had a bactericidal effect and killed the bacteria (figure 2). table 2: multiple comparisons of diameter (cm) among groups using games-howell *=significant at p<0.05, ^=not significant at p>0.05. (i) groups (j) groups mean difference (i-j) p value 25 50 .000 . 75 -1.000 0.000* 100 -1.130 0.000* 125 -1.400 0.000* dw .000 chx -1.4 0.000* 50 75 -1.000 0.000* 100 -1.130 0.000* 125 -1.400 0.000* dw .000 chx -1.4 0.000* 75 100 -.130 0.212^ 125 -.400 0.000* dw 1.000 0.000* chx -0.4 0.000* 100 125 -.270 0.002* dw 1.130 0.000* chx -0.27 0.001* 125 dw 1.400 0.000* chx 0.000 1.00^ dw chx -1.4 0.000* j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 38 figure 2: brain heart infusion shows the minimum inhibitory concentration and minimum bactericidal concentration. cytotoxicity of nano-silver fluoride: haemolytic activity in human erythrocytes the percentage of vital cells was normally distributed among the abo groups and concentration using the shapiro-wilk test (p>0.05). the vitality of cells among the eight groups of concentrations for each blood group is demonstrated in table 3. the greatest mean of the vital cells belonged to the first concentration followed by the second one, while it was the lowest in the last concentration with a statistically significant difference. meanwhile, the highest mean of the vital cells was found in blood group b followed by blood group a, while it was the lowest in blood group o. following the multiple pairwise comparisons, it was clear that when comparing the 2nd concentration with the 1st and 3rd and when comparing the 5th with the last one, these results were not significant statistically, while the other comparisons were significant (table 4). for the experiment, the material was considered to be toxic when it caused hemolysis to 50% of the red blood cell, so nsf-mole was considered toxic at the higher concentrations (240, 400) ppm, while it was considered nontoxic at the other concentrations (120, 60, 20), figure 2. j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 39 table 3: the cell vitality among the concentration groups by abo blood groups. abo blood groups groups minimum maximum mean ±sd ±se f p-value a 8 88.570 92.195 90.007 1.926 1.112 36.920 0.000* 20 85.122 88.310 86.277 1.766 1.020 60 69.697 76.360 73.238 3.351 1.935 120 28.375 56.620 42.966 14.146 8.167 240 33.884 42.340 36.790 4.808 2.776 400 .000 29.268 13.219 14.838 8.567 b 8 93.000 96.140 94.846 1.641 0.947 198.207 0.000* 20 92.820 95.062 93.914 1.122 0.648 60 88.246 89.690 89.118 .768 0.443 120 59.649 71.270 64.039 6.310 3.643 240 .000 15.789 8.614 7.992 4.614 400 .000 13.860 7.383 6.974 4.027 o 8 90.952 91.111 91.022 .081 0.047 47.876 0.000* 20 83.333 89.717 86.255 3.226 1.863 60 59.126 66.667 64.005 4.231 2.443 120 41.645 55.111 48.760 6.765 3.906 240 -1.028 28.889 12.461 15.173 8.760 400 -11.825 16.000 3.773 14.215 8.207 8 88.570 96.140 91.958 2.547 0.849 98.435 0.000* 20 83.333 95.062 88.815 4.280 1.427 60 59.126 89.690 75.454 11.333 3.778 120 28.375 71.270 51.922 12.662 4.221 240 -1.028 42.340 19.289 15.949 5.316 400 -11.825 29.268 8.125 11.609 3.870 *=significant at p<0.05, ^=not significant at p>0.05. figure 2: mean of vital cells among the eight concentrations. j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 40 table 4: multiple comparisons of vitality between groups using dunnett t3 (i) groups (j) groups mean difference (i-j) p value 8 20 3.143 0.612 ^ 60 16.505 0.026* 120 40.037 0.000* 240 72.670 0.000* 400 83.833 0.000* 20 60 13.362 0.086 ^ 120 36.894 0.000* 240 69.527 0.000* 400 80.690 0.000* 60 120 23.532 0.011* 240 56.165 0.000* 400 67.329 0.000* 120 240 32.633 0.003* 400 43.797 0.000* 240 400 11.164 0.740^ ^=not significant at p>0.05, *= significant at p<0.05 discussion new comprehensive caries preventive methods should include fluoride and other agents that influence the deand remineralization balance, as well as antibacterial strategies (9, 30). in recent years, many researchers had focused on developing modified or unique synthetic procedures for the silver nanoparticles rather than using the traditional methods, which had been linked to toxic environmental impacts (31). in the present study, nsf-mole was synthesized by a green method from leaf extract samples of the medicinal tree species m. oleifera, which was a cost-effective synthesis technique (4,8,22). to make the new nanoscale biological compound a more effective material affecting the balance between deand remineralization (32).and to enhance the antimicrobial strategy (33), fluoride was added to reduce biofilm formation and adhesion, as well as reduce acid production to prevent demineralization (34). this study reported the characterization and testing of the nsf-mole, which contained silver nanoparticle synthesized from moringa oleifera leaf extract and fluoride. the color of this material was yellowish-brown. this color belongs to the surface plasmon resonance (spr) of agnps, which is an intrinsic feature of agnps (oda et al., 2019) (29). meanwhile, silver nanoparticle produced from cauliflower extract has brownish-red color (oda et al., 2019) (29), while that produced from beta vulgaris extract has a yellow-orange color (hashim and oda, 2019) (23), silver nanoparticle produced from mace-arils of myristica fragrans has a pale, brownish solution (rizwana et al., 2021) (6). the antimicrobial activity of silver nanoparticles was tested and compared to chlorhexidine, which could reduce streptococcus mutans in saliva (35). j. bagh. coll. dent. vol. 35, no. 2. 2023 kadhem and al haidar 41 the nanoparticle produced from green synthesis was spherical and the particle size was in the range of 19 to 50 nm proving that the antibacterial activity of silver nanoparticles against s. mutans increases as the particle size decreases. this result met the findings of espinosa-cristobal et al. in 2009 (36), morones et al. in 2005 (37), and baker et al. in 2005 (38). chlorhexidine is a chemical substance, which is considered a bactericidal, antiseptic, and antifungal substance that is active against both gram-positive and gram-negative bacteria. it also possesses bacteriostatic properties, preventing bacterial proliferation by disrupting cell membranes rather than inactivating atpase, as previously thought (39). due to the differences in the characteristics of the various bacterial strains and the reduction in the size of silver nanoparticles (40), it was difficult to compare the mic values with those of other researchers. systematic reviews, on the other hand, concluded that chlorhexidine had limited scientific evidence to be used as a dental caries preventative agent (39). silver-containing compounds, such as sdf, had been used in dentistry with excellent clinical efficacy (41). thus, silver nanoparticle-containing compounds have a great deal of potential for preventing dental caries. the hemolytic test is an effective in vitro system that may be used to study the toxic and protective effects of a wide range of substances or conditions linked with oxidative stress (9). cytotoxicity of nsf-mole was tested and found that there is a significant concentration-related cytotoxicity of nsf-mole (the number of vital cell decrease as the concentration increase) (42). nsf-mole was nontoxic at low concentrations (120, 60,20, 8) ppm this finding was consistent with that of targino et al. in 2014 who tested the cytotoxicity of nano-silver fluoride on human erythrocyte and found that nano-silver fluoride was safe in all concentrations tested regardless of blood group type (9). while the high concentration (200, 400) ppm caused hemolysis to more than 50% of the cells, thus considered toxic. hernández-sierra et al. in 2011 found that agnps <20 nm increased cytotoxicity in human periodontal fibroblasts in a concentrationand time-dependent manner (42). conclusion the current study showed that nsf-mole had a good bacteriostatic and bactericidal effect on streptococcus mutans similar to chlorohexidine with no cytotoxic effect on living human erythrocytes at the low concentration, thus it is considered a good noninvasive technique for the 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(crossref) االعنوان: الفعالية المضادة للبكتريا والتأثير السام لمادة فلوريد الفضة النانوي المصنع من مستخلص أوراق شجرة المورينغ , اسيل حيدر محمد جواد الباحثون: دعاء جواد كاظم المستخلص: وم للخاليا لفلوريد األسنان والطب الحيوي اولي للجسيمات النانوية الفضية بسبب نشاطها المضاد للميكروبات. الهدف: تقييم النشاط المضاد للميكروبات والسمالخلفية: اهتمام كبير في طب ضد المكورات العقدية. الطريقة: تم مستخلص أوراق المورينجا أوليفيرا من تصنيعه تم ر حديثًا والذي فلوريد الفضة النانوية الفضة النانو المطوَّ استخدام طريقة التخليق األخضر لتحضير mbc120 ppm,mic)نما تم تقييم السمية الخلوية مستخلص أوراق المورينجا أوليفيرا. تم تقييم الحد األدنى للتركيز المثبط والحد األدنى من تركيز مبيد الجراثيم باستخدام االجار ، بي من 60 ppm)ومقاوم للبكتريا ، ويزداد قطر منطقة التثبيط مع زيادة التركيز. فلوريد الفضة النانوي كان سام من خالل النشاط االنحاللي. النتيجة: كان لفلوريد الفضة النانوي تأثير مبيد للبكتريا ن وهي آمنة لالستخدام على اإلنسان.عند التركيز العالي وغير سام عند التركيز المنخفض. الخالصة: فلوريد الفضة النانوي مادة جيدة الستخدامها في إيقاف ومنع تسوس األسنا https://doi.org/10.1159/000217860 https://doi.org/10.1177/154405910508400807 http://dx.doi.org/10.1016/j.matlet.2009.09.018 https://doi.org/10.1088/0957-4484/16/10/059 https://doi.org/10.1166/jnn.2005.034 https://doi.org/10.2341/08-3 https://doi.org/10.3109/17435390.2012.742935 https://doi.org/10.1177/0022034508329406 https://doi.org/10.17796/jcpd.36.1.d677647166398886 huda.doc j bagh college dentistry vol. 27(2), june 2015 depression status pedodontics, orthodontics and preventive dentistry158 depression status in relation to caries experience and salivary physiochemical characteristics among 15 years old students in al-swera city – wassit governorate-iraq huda s. khiala, b.d.s. (1) ban s. diab, b.d.s., m.sc., ph.d. (2) abstract background: depression is a common mental disorder that presents with depressed mood;it can become chronic or recurrent and affect dental health .thus this research aimed to assess the prevalence and severity of dental caries among students with different grade of depression in relation to physicochemical characteristics of stimulated whole saliva. materials and methods: the total sample involved for depression status assessment is composed of 800 students for both gender aged 15 years old that were selected randomly , this was performed using children depression inventory (cdi) index that divided the students into four groups of depression(low or average grade, high average grade, elevated grade and very elevated grade). the diagnosis and recording of dental caries was by using decay, missing, filled surface index (dmfs); and according to the criteria ofmanji et al (1989), salivary samples was collected from 30 student with very elevated grade of depression and 30 from low or average grade under standardized conditions, then analyzed for measuring salivary flow rate and viscosity, in addition to estimation salivary elements that includes total protein, zinc, copper, chromium and lithium. results: the data of the present study showed that the percentage of caries free students was higher among very elevated grade (8.60%) followed by low or average grade (8.52%), the less was among elevated grade of depression (5.04%).concerning caries experience, the highest result was among elevated grade of depression followed by low or average grade, the lower result was among high average grade. while the sever grade of dental caries (d4) was found to be highly significant differ among different grade of depression, the data analysis of salivary elements found that the protein was higher in very elevated grade than low or average grade while other elements show the opposite result with significant concerning copper and zinc among very elevated grade that show significant difference. dmfs correlated negatively with salivary flow rate among low or average grade and very elevated grade; while concerning salivary viscosity, the correlation was direct with dmfs. with highly significant in very elevated grade, salivary elements show positive relation with not significant except copper that show negative relation with significant. conclusion: the results of the current research revealed that depression status had an adverse effect on salivary physicochemical characteristics and dental status including caries experience key words: depression, dental caries, salivary elements. (j bagh coll dentistry 2015; 27(2):158-162). introduction depression is a common mental disorder that presents with depressed mood, loss of interest pleasure, decreased energy lead to substantial impairments in an individual’s ability to take care of his or her everyday responsibilities(1). depression is an important cause of morbidity, and the world health organization (who) has predicted that depression will be the second leading contributor to the global burden of disease (2). varity of studies indicated there is a relation between depression and concentration of different nutritional and toxic elements in human body (total protein, zinc, copper, chromium and lithium) (3-7). dental caries is one of the most common, communicable and intractable infectious disease in human (8). dental caries is strongly age–related, as there is an often an increase in severity and prevalence with increase age (9). (1)m.sc. student department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2)professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad adolescence can be defined as a major life stage in which a child matures physically into an adult (10). psychological changes begin during puberty and continue through adolescence directly affected nutritional status and nutritional needs (11). depression is always connected with a declined metabolism of serotonin, which is later linked to the high carbohydrate intake. this lays the foundation for favorable conditions for the development of acid uric bacteria. the existence of a high prevalence of these bacteria indicates the growth and progression of dental caries (12). many of protein molecules secreted by the salivary glands are of extreme importance in protecting the integrity of the teeth (13), they found a significant effect of zinc salts rinsing in decreasing streptococcus mutans counts (14). thus, several researches found inverse correlation of salivary zinc with dental caries (15,16), whereas the elements copper and lithium present in food or water protect the teeth and act as cariostatic (17), whereas cr ions may play a role in improving mineralization and crystallity of teeth (18). j bagh college dentistry vol. 27(2), june 2015 depression status pedodontics, orthodontics and preventive dentistry159 saliva is a biologic fluid in the oral cavity, composed of a mixture of secretary products from the major and minor salivary glands (19), reduced salivary flow rate and hyposalivation leading to oral dryness might be the effect of psychological processes (anxiety, stress, depression etc.) (20). there is a negative relation between the salivary flow rate and dental caries (21).viscosity means the resistance to flow or alteration of shape by any substance as a result of molecular cohesion (22), increased salivary viscosity plays a role in increasing caries incidence (23). materials and methods the sample size composed of 800 students male and female, that they were distributed in secondary schools of swera center which randomly selected from different areas and represented 90% of the number of intermediate schools of al-swera center. the whole male and females age 15 year old attending the selected secondary schools were examined depression status assessment by children inventory index (cdi2 (24) and oral examination; then subgroups of 30 students from both very elevated grade and low or average grade were randomly selected for salivary analysis. the caries experience was recorded by decay, missing, filling index (dmfs) and by using the criteria of manjie et al (25), which allow recording decayed lesion by severity. the collection ofstimulated salivary samples were performed under standard condition following instruction cited by tenovuo and lagerl (26). the salivary flow rate was measured as milliliter per minute (ml / min); while viscosity was assessed by using ostwald's viscometer. target salivary elements were analyzed at the poisoning consultation center / specialized surgeries hospital. salivary total protein, zinc, copper, chromium and lithium, analyzed, using absorption spectrophotometer (buck scientific, 210vgpusa) following standardized procedure, while the method used to determine the level of salivary total protein is colometric method by using of special kits according to the manufactured instructions. data analysis was conducted by application of spss program version 21. results the result of the present study showed that the percentage of caries free students was higher among very elevated grade (8.60%) followed by low or average grade (8.52%), the less was in elevated grade of depression (5.04%) and that showed in table (1). concerning cariesexperience, the highest result was among elevated grade of depression followed by low or average grade with not significant. concerning the severity of dental caries (d1-d4), the result was higher among very elevated grade with highly significant (p=0.01), followed by low oraverage grade and then high average grade and the lower one was elevated grade the data analysis of salivary elements found that the protein was higher in very elevated grade than low or average grade while other elements show the opposite result with significant concerning copper and zinc in very elevated grade that show significant difference, while others the differences were not significant. dmfs and its grades correlated negatively with salivary flow rate among low or average grade and very elevated grade; while concerning salivary viscosity, the correlation was direct with highly significant in very elevated grade. salivary elements show positive not significant relation except copper that show negative relation with significant. table 1: distribution of caries free students according to depression depression grades very elevated elevated high average low or average % no % no % no % no 27.63 221 14.88 119 17.88 143 39.63 317 total table 2: dental caries experience dmfs and its components (ds, ms, fs)(median, mean rank) according to depression grade by gender . chi depression grades vey elevated elevated high average low or average mean rank median mean rank median mean rank median mean rank median 4.19 407.75 6.00 426.14 7.00 368.57 5.00 400.5 6.00 ds 2.87 393.53 0.00 414.42 0.00 393.54 0.00 404.11 0.00 ms 0.20 402.03 0.00 402.53 0.00 398.79 0.00 400.52 0.00 fs 5.68 402.26 6.00 431.85 7.00 365.16 6.00 403.97 7.00 dmfs j bagh college dentistry vol. 27(2), june 2015 depression status pedodontics, orthodontics and preventive dentistry160 table 3: severity of dental caries represented by grades of (d1-d4) (median, mean rank) according to depression grades by gender chi depression grades very elevated elevated high average low or average mean rank median mean rank median mean rank median mean rank median 1.25 201.14 2.00 189.95 2.00 201.82 1,00 198.86 2.00 d1 1.01 405.67 0.00 396.12 0.00 384.97 1,00 405.49 1.00 d2 1.31 404.73 0.00 410.56 0.00 393.56 0,00 397.05 0.00 d3 11.28** 421.95 0.00 361.95 0.00 390.19 0.00 405.05 0.00 d4 ** highly significant p≤ 0.01 table 4: the salivary physicochemical characteristics among students with very elevated grade and low or average grade of depression u-test z depression grades very elevated low or average mean rank median mean rank median 436.500 -0.20 31.58 80.68 30.44 60.69 protein (mg ∕l) 392.000 -0.85 28.76 3.69 33.33 4.15 zinc (µg ∕l) 396.000 -0.80 34.06 2.60 27.94 2.70 copper (µg ∕l) 432.500 -0.25 29.2 0.11 32.8 0.11 chromium (µg∕l) 413.000 -0.54 29.77 1.07 32.23 1.12 flow rate (ml ∕min) table 5: salivary viscosity (poise) among students with very elevated grade and low or average grade of depression depression grades statistical difference low or average very elevated df t-value p mean ±sd mean ±sd total 0.0143 0.0075 0.0154 0.0087 58 -1.03 0.428 table 5: correlation coefficient between the salivary physicochemical characteristics and caries experience (ds and dmfs) dmfs ds very elevated low or average very elevated low or average p r p r p r p r 0.48 0.13 0.08 0.32 0.55 0.11 0.05* 0.35 protein 0.07* 0.32 0.86 0.03 0.09 0.31 0.27 0.20 zinc 0.07* 0.33 0.49 0.13 0.17 0.25 0.20 0.23 copper 0.83 0.04 0.12 0.28 0.31 0.18 0.20 0.23 chromium 0.41 0.22 0.41 -0.15 0.30 -0.22 0.44 -0.41 flow rate 0.005** 0.499 0.63 -0.09 0.004** 0.507 0.995 -0.001 saliva viscosity *significant p≤ 0.05 ** highly significant p≤0.01 discussion in this study, the prevalence and the experience of dental caries among elevated grade were nonsignificantly higher than other grades of depression, the increased dental caries in depressed individuals agrees with other study (27), could be attributed to that depression is always connected with a declined metabolism of serotonin, which is later linked to the high carbohydrate intake. other explanation could be the limitations in sunlight exposure that was reported among depressed person that leads to vitamin d deficiency (28), as individual patients may have symptoms of depression related to potentially deficient vitamin d levels (29) that reported to be associated with increased dental caries (30). moreover, other condition could be the decreased in salivary flow rate among students with very elevated grade of depression, thehigher the flow rate, faster the clearance, higher the buffer capacity(31),(32). this result also found in the present study by the inverse relation between the salivary flow rate and dental caries among both groups other factor could be increase in salivary viscosity among students with very elevated grade than low or average grade with not significant and that agree with other study (33).the higher viscosity the less capable of flowing freely to oral sites where its protective functions such as j bagh college dentistry vol. 27(2), june 2015 depression status pedodontics, orthodontics and preventive dentistry161 clearance would be affected (34,35). this also found in the present study as saliva viscosity show positive relation with dental caries in very elevated grade. all elements in this study related positively with dental caries with not significant in the two grade of depression, for total protein, the host salivary protein csp-1 binds to s. mutans cells and may influence the initial colonization of this pathogenic bacterium onto the tooth surface (36). additionally, salivary copper as other trace elements are essential for growth and metabolism of bacteria, but become injurious if presents in a high concentration (37). concerning salivary zinc enhanced remineralization especially in deeper part and exhibited detrimental effects on remineralization in a dose response manner (38). this study did not show any results for the concentration of lithium in saliva using spectrophotometer device, the likelihood that small concentration of lithium in the two grade that was not detected in the device and that need further studies, also the distribution of depression was 100% and lithium has been shown to reduce the oxidative stress that occurs with multiple episodes of mania and depression, lithium is the first drug used for depression (39). references 1rosner rm. text book of adolescent psychiatry. 1st ed. new york university; 2003. 2kessler r. the epidemiology of major depressive disorder: results from the national comorbidity survey replication (ncs-r) jama 2003; 289: 3095– 3105. 3hani m, esashi t. the effects of calcium, phosphorus, magnesium, sodium and zinc in improving the depression of gonadal development in growing male rats kept under disturbed daily rhythm –investigations based on the l(16)(2(15)-type orthogonal arry. j nutr sci 2007; 52(5): 368-75. 4hansen s, ashwell m, legleiter l, fry r, lioyd k, spears j. the addition of high manganese to a copper –deficient diet further depressed copper status and growth of cattle.br j nutr 2009; 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j, et al. the diurnal salivary cortisol pattern of adolescents from families with single, ill and healthy parents.journal of psychosomatic research. 2012; 72(4): 288–92. 34madléna m, farago r, lukacs p, fogorv sz. various aspects of dental prevention in the elderly 2007; 100 (6): 289-93. 35zussman e, yarin al, nagler rm. ageand flowdependency of salivary viscoelastisity. jdr 2007; 86 (3): 281-5. 36ambatipudi k, bingwen lu, hagen f, james e, et al. quantitative analysis of age specific variation in the abundance of human female parotid salivary proteins. j proteome res 2009; 8(11): 5093–102. 37hardwick j. trace element in dental plaque. in: curzon m. and cutress t. ed. trace. elements and dental disease. psg. inc. boston.1983, 117-148. 38lippert f. dose response effects of zinc and fluoride on caries lesion remineralization. caries res 2012; 46(1): 62-8. 39malhi gs, tanious m, das p, coulston cm et al. potential mechanisms of action of lithium in bipolar disorder. current understanding. cns drugs, 2013; 27(2):135-53. الخالصة وھذا یھدف ھذا البحث إلى تقییم مدى انتشار وشدة تسوس . االكتئاب ھو اضطراب عقلي لمشترك مع مزاج مكتئب، ویمكن أن تصبح مزمنة أو متكررة وتؤثر على صحة األسنان األسنان بین الطالب مع درجة مختلفة من االكتئاب بالنسبة للخصائص الفیزیائیة للعاب المحفز .المحفز یھدف ھذا البحث إلى تقییم مدى انتشار وشدة تسوس األسنان بین الطالب مع درجة مختلفة من االكتئاب بالنسبة للخصائص الفیزیائیة لللعاب:ھالدراس اھداف سنة التي تم اختیارھا عشوائیا، تم تنفیذ ذلك باستخدام 15طالب لكال الجنسین الذین تتراوح أعمارھم بین 800تكون العینة الكلیة المعنیة لتقییم الوضع االكتئاب من :المواد واالسالیب وكان ). ارتفاع ، و مرتفع ودرجة مرتفعة جداالدرجة المنخفضة أو المتوسط ، متوسط (وتم تقسیم الطالب إلى أربع مجموعات من االكتئاب ) cdi(مؤشر األطفال االكتئاب لالطفال من الدرجة المنخفضة أو 30طالب بتقدیر مرتفع جدا من االكتئاب و 30، تم جمع العینات اللعابیة من ,manji) 1989(وفقا لمعیار ).dmfs(التشخیص باستخدام مؤشر التسوس .ك والنحاس والكروم واللیثیومزنفي ظل ظروف موحدة، ثم تحلیلھا لقیاس معدل تدفق اللعاب واللزوجة، باإلضافة إلى تقدیر عناصر اللعابیة التي تتضمن البروتین الكلي والالمتوسط ، وكانت أقل بین )٪8.52(، یلیھ الدرجة المنخفضة أو المتوسطھ )٪8.60(أظھرت بیانات ھذه الدراسة أن نسبة تسوس الطالب كان أعلى بین درجة مرتفعة جدا من االكتئاب :النتائج ، كانت النتیجة أقل بین متوسط ة أعلى بین الدرجة المرتفعة من االكتئاب تلیھا الدرجة المنخفضة أو المتوسطفیما یتعلقبالتسوس ، كانت النتیج). ٪5.04(درجة مرتفعة من االكتئاب ن كان أعلى في ووجد تحلیل البیانات للعناصر اللعابیة أن البروتی. كانت كبیرة بین الدرجھ العالیھ من االكتئاب وبصوره واضحھ ) d4(في حین ان شده تسوس األسنان . الدرجة العالیة على dmfsوكان المؤشر .في حین تظھر عناصر أخرى العكس وكانت الصوره واضحھ في الزنك والنحاس, الصف مرتفعة جدا من االكتئاب من الدرجة المنخفضة أو المتوسطھ واضحھ في ,مع أھمیة . dmfsھ اللعاب كانت عالقتھا مباشره مع المؤشر، بینما لزوج. ودرجة مرتفعة جداعالقھ سلبیھ مع معدل تدفق اللعاب بین الدرجة المنخفضة أو المتوسط .. الصفوف المرتفعة جداز تظھر العناصر اللعابیة عالقة إیجابیة و غیر الھامة باستثناء النحاس التي تظھر عالقة سلبیة مع أھمیة .على الخصائص الفیزیائیة اللعابیة وحالة تسوس األسنان كشفت نتائج األبحاث الحالیة أن الوضع االكتئاب لھ تأثیر سلبي :االستنتاجات j bagh college dentistry vol. 26(1), march 2014 evaluation the effect restorative dentistry 37 evaluation the effect of nano-fillers (tio2, al2o3, sio2) addition on glass transition temperature, e-moudulus and coefficient of thermal expansion of acrylic denture base material ihab n. safi, b.d.s., m.sc. (1) abstract background: the pmma polymer denture base materials are low in thermal and strength properties. the aim of the study was to investigate the change in glass transition temperature, e-moudulus and coefficient of thermal expansion of acrylic denture base material by addition of al2o3, tio2 and sio2nano-fillers in 5% by weight. materials and methods: the type of polymerization is free radical bulk polymerization. one hundred twenty (120) specimens were prepared , the specimens were divided into four groups according to the material had been added (one control and three for al2o3, tio2 and sio2nanocomposite) each group was subdivided in to three groups according to the test had been done on it, the degree of transition (tg) was measured by the differential scanning calorimeter (dsc), e-modulus and coefficient of thermal expansion and contraction was measured by thermo mechanical analyzer (tma) .each sample was tested at different temperatures (30,40,50,60,70c°). results: highly significant decrease in coefficient thermal expansion and contraction and in e-modulus occurred in acrylic incorporated with al2o3, tio2 and sio2 nano-fillers in 5% by weight when compared to control group. for glass transition temperature a significant increase had occurred with the addition of nanofillers at 5% when compared to control group. conclusion: the results showed that the polymer nanocomposites possess material properties different from that of unmodified pmma, nanocomposite has thermal and mechanical stability more than heat neat pmma. keyword: acrylic denture base, nano fillers, thermal properties. (j bagh coll dentistry 2014; 26(1):37-41). الخالصة -eمنخفضة في الخصائص الحرارية والقوة .. وكان الهدف من الدراسة للتحقيق التغيير في درجة حرارة التحول الزجاجي ، pmmaخلفية : البوليمر بدلة المواد األساسية ال moudulus و معامل التمدد الحراري لل مادة االكريليك قاعدة أسنان بإضافةal2o3 ،tio2 وsio2 من وزنها . ٪ 5الحشو في نانو ( العينات ، تم تقسيم العينات إلى أربع مجموعات وفقا للمادة ) عنصر تحكم 021المواد و األساليب: نوع البلمرة مجانية البلمرة الراديكالية األكبر . قد أضيفت أعدت مائة وعشرين ) سيم كل مجموعة إلى ثالث مجموعات وفقا الختبار زيارتها تم القيام به على ذلك، تم قياس درجة التحول بمركب متناهي في الصغر ( تم تق sio2و al2o3 ،tio2واحد وثالثة ل ( . تم اختبار كل عينة في tmaمعامل و معامل التمدد الحراري واالنكماش و تقاس الحرارية محلل الميكانيكية ) -e، ( dsc) تيراغرام ( بواسطة المسعر المسح التفاضلي ) ° ( . c 01،01،51،01،01ت حرارة مختلفة ) درجا من الوزن مقارنة ٪ 5نانو الحشو في sio2و al2o3 ،tio2معامل وقعت في االكريليك تدمج مع -eالنتائج : انخفاض كبير للغاية في معامل التمدد الحراري واالنكماش و مقارنة بالمجموعة الضابطة . ٪ 5ثت مع إضافة المالئة النانومترية في بالمجموعة الضابطة . ل درجة حرارة التحول الزجاجي زيادة كبيرة حد معدلة ، بمركب متناهي في الصغر لديه االستقرار الحراري و pmmaو البوليمر تمتلك خصائص مواد مختلفة عن تلك التي nanocompositesاالستنتاج : أظهرت النتائج أن أنيق. pmmaالميكانيكي أكثر من الحرارة لكلمة الرئيسية: أكريليك قاعدة أسنان ، والحشو نانو، الخواص الحرارية .ا introduction polymer nanocomposite gained attention of researches because of their novel properties that are derived from the two components (1).the addition of very small amount less than 5%fillers to apolymeric matrix has significant impact on the thermal and mechanical properties of the polymer (2).the pmma polymer denture base materials are low in thermal and strength properties (3,4). when the temperature increases polymers show a large variation of mechanical and physical properties .the acrylic resin is hard and glass like at room temperature and with increase in the temperature to a critical temperature a transition occur to flexible and soft material, this transition occurs over a critical temperature termed glass transition temperature (tg)(5). at (tg) temperature a sharp increase in the thermal expansion coefficient occurs, indicating increased molecular mobility (6). (1) assistant lecturer. department of prosthodontics, college of dentistry, university of baghdad. the dimensional stability of acrylic denture base resin was related to this temperature, as the polymers goes from a hard state to a soft state. the coefficient of thermal expansion of the polymer changes, this change corresponds to tg (7) .the denture should be above the tg while it is in service during finishing and polishing by dentist and technician and during cleaning in hot water by the patient. now attention is directed toward addition of inorganic nanoparticles to pmma to improve its thermal stability and thermal mechanical behavior (8-10). the nanofillers particles are expected to disperse more homogeneously than large microfillers within a polymer host, this interaction between nanofiller and polymer lead to the properties of the composite materials. nanocomposites display glass transition temperature and thermal degradation that are higher 15 °c and 60 °c than pmma respectively (11). nanocomposites had higher storage modulus and higher glass transition temperature (tg) than j bagh college dentistry vol. 26(1), march 2014 evaluation the effect restorative dentistry 38 pure pmma which were measured by dynamic mechanical properties (12). there is improvement in glass transitiontemperature and in heat resistance of nanocomposite reached to 16 °c and 14 °c respectively (13). young modulus decreased by 20% after addition of nanofillers to pmma nanocomposite. the best result in physical and mechanical properties was observed in denture base reinforced with 5wt% of nano-zro2 (14). in this study three types of inorganic nanofillers were used that were added to heat cure pmma at 5wt% and evaluate the effect ofthis addition on physical (tg, coefficient of thermal expansion and contraction) and mechanical property (e-modulus) of heat cured acrylic denture base material. materials and methods table 1: list of the materials that were used material tio2nanofiller al2o3nano filler sio2 nanofiller heat-curing resin for denture manufacturer sigma-aldrich germ. sigma-aldrich germany. sigma-aldrich germ. superacr-yl plus czechoslovakia test specimens preparation two different metal patterns were constructed according to the required test. the pattern that was constructed for coefficient of thermal expansion and contraction test and e-modulus test was a cylindrical shaped specimen (15mm x 6mm) length, diameter respectively (5) .for glass transition temperature test: a bar shaped specimen was constructed (65mm x 10mm x 2.5mm) length, width, thickness respectively (15-17). mould preparation addition of fillers an electronic balance was used with accuracy of (0.0001g) (sartorius bp 30155, germany) for addition of nanofillers powder at weight 5% to monomer. after the addition of nano filler to monomer, the powder of fillersseparated into individual nano crystals which were dispersed in the monomer byusing sonication apparatus (soniprep-150, england) at 120 w, 60 khz for 3 minutes (14).to reduce the possibility of particle aggregation proportioning and mixing of the acrylic the suspension of the monomer with nano filler was immediately mixed with acrylic powder. all materials were mixed and manipulated according to manufacture’s instructions for acrylic resin at ratio of (2.5g:1g) p/l .the mixing was carried outby a clean wax knife in a clean and dry mixing vessel and mixed for 30 second. the mixture was then covered and left to stand until a dough stage was reached.using a conventional denture flasking technique. thermal analysis and mechanical tests 1-measuring of tg . a-specimen form: the specimen should be in powder form 10 mg powder is prepared so the acrylic specimens were shaved with a sharp knife (figure 1) . figure 1: prepared powder form b-the procedure: the differential scanning calorimeter (dsc-60 from shimadzu, japan) (figure 2) is an instrument that is used to determine the thermal transition (tg). the dsc device is connected to a control and program unit that show the data ,tg value is determined by computer .the acrylic powder of the specimen was put in an aluminum pan of dsc device, with an empty aluminum pan as a reference, tg value was determined on dsc thermogram. before starting measurement the heating rate used was (10 c/min) and chart speed of (20mm/min) was selected for all the heating operations. using a predefined temperature range from 20 c to 190 c in dynamic air atmosphere (flow rate 25 cm3/min). figure 2: dsc device 2-measuring of the coefficient of the thermal expansion and contraction ( ) . a-specimen form :the acrylic specimen should be in cylindrical form of dimension 15mm in length and 6 mm diameter to coincide the probe of j bagh college dentistry vol. 26(1), march 2014 evaluation the effect restorative dentistry 39 thermo-mechanical analyzer(tma) which is 5 -6 mm in diameter (figure 3). figure 3: cylindrical form. b-the procedure: thermo mechanical analyzer (tma, pt1000 from linseis, un) (figure4) is an instrument that is used to determine thecoefficient of thermal expansion and contraction ( ).the probe of tma device has 5-6 mm in diameter which rests on cylindrical specimen of 6mm in diameter and 15 mm in length .tma device was connected with programs units that show the data on computer . before measurement a heating rate of 10 c/min was selected (15). figure 4: tma device coefficient of thermal expansion and contraction ( ) was determined by measuring the change in length (l) per unit length for each c temperature change (t)or measuring the change in volume by increase the temperature at constant pressure per unit volume. in this study the following equation was used: ( )= 3measuring of modulus of elasticity (emodulus). aspecimen form: the acrylic specimen should be in cylindrical form of dimension 15mm in length and 6 mm diameter. b-the procedure: the same method as in tma was used,a heating rate of 10 c/min and load of 50 gm was selected (15). e-modulus was determined by computer by measuring the ratio of elastic stress to elastic strain. e=stress/strain results mean values, standard deviation, standard error, t-test and p-value forglass transiaion temperatureare presented in table (2). table 2: descriptive of glass transition temperature control tio2 sio2 al2o3 anova mean 85.6 118.6 102.4 113.2 ftest=60.852 p<0.01 hs sd 6.693 2.607 3.361 2.588 t-test 8.578 4.221 7.819 p-value 0.001 0.013 0.001 sig hs s hs coefficient of thermal expansion and contraction tests result are presented in table (3,4,5,6,7),one way anova test betweengroups at different temperatures (30,40,50,60,70c°) is presented in table(8) . table 3: descriptive data of coefficient of thermal expansion and contraction at 30 c° temp. 30 c° control tio2 sio2 al2o3 mean 72 57 68 63 sd 1.58113 1.5811 1.58113 1.58113 t-test 17.928 4.781 10.757 p-value p<0.01 p<0.01 p<0.01 sig hs hs hs table 4: descriptive data of coefficient of thermal at 40 c°. temp. 40 c° control tio2 sio2 al2o3 mean 85 75 81 77 sd 1.5811 1.5811 1.5811 1.5811 t-test 7.906 2.902 9.562 p-value 0.001 0.044 0.001 sig hs s hs table 5: descriptive data of coefficient of thermal at 50 c° temp. 50 c° control tio2 sio2 al2o3 mean 93 86 90 86 sd 1.58113 2.2360 2.549 2.549 t-test 7.376 5.447 12.780 p-value 0.002 0.005 p<0.01 sig hs hs hs j bagh college dentistry vol. 26(1), march 2014 evaluation the effect restorative dentistry 40 table 6: descriptive data of coefficient of thermal expansion and contraction at 60 c° temp. 60 c° control tio2 sio2 al2o3 mean 100 95 96 93 sd 1.58113 1.5811 1.58113 1.5811 t-test 9.129 2.981 5.916 p-value 0.001 0.041 0.004 sig hs s hs table 7: descriptive data of coefficient of thermal expansion and contraction at 70 c° temp. 70 c° control tio2 sio2 al2o3 mean 105 100 97 98 sd 2.5495 2.5495 3.3911 3.1622 t-test 0.00 7.628 2.746 p-value 1.000 0.002 0.049 sig ns hs s table 8: anova of coefficient of thermal expansion and contraction anova control tio2 sio2 al2o3 f-test 265.8 388.56 143.43 200.31 p-value p<0.01 p<0.01 p<0.01 p<0.01 sig hs hs hs hs mean values, standard deviation, standard error, t-test and p-value for e-modulus tests result are presented in table (9,10,11,12,13), one way anova test between groups at different temperatures (30,40,50,60,70c°) is presented in table (13) . table 9: descriptive data of e-modulus (n/mm2) at 30 c° temp. 30 c° control tio2 sio2 al2o3 mean 2119 451 1233 1738 sd 17.117 4.1231 26.580 24.738 t-test 286.06 63.627 105.657 p-value p<0.01 p<0.01 p<0.01 sig hs hs hs table 10: descriptive data of e-modulus (n/mm2) at 40 c° temp. 40 c° control tio2 sio2 al2o3 mean 2522 531.2 1405 2305.4 sd 11.510 22.653 21.908 25.880 t-test 215.502 112.54 14.554 p-value p<0.01 p<0.01 p<0.01 sig hs hs hs table 11: descriptive data of e-modulus (n/mm2) at 50 c° temp. 50 c° control tio2 sio2 al2o3 mean 2748.8 602.8 1772.6 2684.2 sd 74.30141 23.40299 25.48137 27.09613 t-test 48.786 42.05 2.932 p-value p<0.01 p<0.01 0.043 sig hs hs s table 12: descriptive data of e-modulus (n/mm2) at 60 c° temp. 60 c° control tio2 sio2 al2o3 mean 2785 682.2 2068.4 2023.4 sd 24.217 25.655 27.790 49.952 t-test 131.26 82.167 36.05 p-value p<0.01 p<0.01 p<0.01 sig hs hs hs table 13: descriptive data of e-modulus (n/mm2) at 70 c° temp. 70 c° control tio2 sio2 al2o3 mean 2824 772.6 2217 2201.8 sd 97.203 14.518 78.185 129.438 t-test 41.27 13.001 6.146 p-value p<0.01 p<0.01 0.004 sig hs hs hs table 14: anova of e-moudulus (n/mm2) anova control tio2 sio2 al2o3 f-test 134.52 202.8 505.7 143.9 p-value p<0.01 p<0.01 p<0.01 p<0.01 sig hs hs hs hs figure: 5 dsc curve discussion the present study was conducted to evaluate and compare the effect of addition (al2o3, tio2 and sio2nano-fillers) to pmma on thermal and mechanical properties of acrylic denture base. these types of nanofillers were used because of their thermal properties and also because of being white are less likely to alter esthetic. the thermal stability of the samples was examined by tma j bagh college dentistry vol. 26(1), march 2014 evaluation the effect restorative dentistry 41 and dsc (16). thermal properties and e-modulus are tested over a physiologic temperature range (30-70c°). the introduction of nanofillers into pmma caused decrease in the value of coefficient of expansion and contraction, statistically highly significant decrease in low temperature at 30 and became significant decrease at high temperatures (60,70c°). the decrease in the thermal expansion coefficient was due to the greater interfacial interaction between nanofillers and matrix which limited the molecular mobility of polymer (12,13). homogenous distribution of very fine size and high surface area of nanofiller enable them to restrict the motion of macromolecule chains and enhance thermal properties (6,18), that means the pmma nanocomposite has thermal stability more than neat pmma ,in addition to decrease in volume of pmma with present of nanofillerat 5%. in this study tg measured from the temperature of the peak maxima of dsc curves obtained for the pure pmma and pmma nanocomposite. the value of glass transition temperature increased for al2o3 and sio2nanocomposite at 5wt%, the dsc peak shifted toward higher temperature when compared to control group, it was found that the addition of tio2 nanofillers to pmma caused highly increased in tg , it is shows in figure (5),this may be due to the melting temperature of nanofillers are higher, the magnitude of the shift being dependant onthe type and amount of nanofillers. the addition of nanofillers at 5% to pmma led to decrease e-modulus beyond that of pure pmma, these changes are due to excessive interactions between pmma and the large surface area of nanofillers references 1. jorge jh, giampolo et, machado al, vergani ce. cytotoxicity of denture base acrylic resin. literature review. j prosthet dent 2003; 90(2): 190-230. 2. costache mc, wang d, heidecker mj, wilkie ca.the thermal degradation of poly methyl methacrylate nanocomposite with montmorillonite, layered double hydroxides and carbon nanotubes. polym adv technol 2006; 17: 272-80. 3. craig rg. restorative dental materials.11th ed. st. louis: mosby co.; 2002. 4. koroglu a, ozdemir t, sanmaz a.comparative study of the mechanical properties of fiber reinforced denture base resin. j app polym sci 2009; 113(2): 716-20. 5. jerolimor v, jagger rg, millward pl, carekv. effect of heating rate on glass transition of cross-linked denture base resin. acta stomatol croat 1996; 30(4): 249-54. 6. anusavice kj. phillips science of dental materials .11th. st. louis: 2008. 7. craig rg, powers jm, wataha jc. dental material properties and manipulation. 8th ed. st. louis: mosby co.; 2004. 8. arrighi v, kraft a, khlifa ma. thermal and dynamic mechanical properties of solution dispertion nanopartical filler-pmma composites acc national meeting, united states, 2010. 9. ahmed za, alhareb ao. effect of al2o3/zro2 reinforcement on the mechanical properties of pmma denture base. j reinforced plastics and composite. 2011; 30(1): 86-93. 10. escobar ca, zaragoza ea, lucero a.thermal and mechanical analysis of silver/carbon nanopartical– pmma obtained by mini-emulsion polymerization. polym j 2009; 41(10): 816-21. 11. zhang weian, shen x, li yu, fang y. synthesis and characterization of poly methyl methacrylate ommt nanocomposite by gamma-irradiation polymerization. radiation physics and chemistry 2003; 67: 651-6. 12. yan d, ling xu, chen c, tang j, xu ji. enhanced mechanical and thermal properties of rigid polyurethane foam composites containing graphenenanosheets and carbon nanotubes, 2012. 13. benjamin jm, jason s, diana fr, linda ss. investigation into thermal and mechanical behavior of pmma/alumina nanocomposites .materials research society, proceedings library. 661,http:/dxdoi org/2000.10-557. 14. safi in. evalution the effect of modified nanofillers addition on some properties of heat cured acrylic resin denture base material. m.sc. thesis. college of dentistry /university of baghdad, 2011. 15. al-taie ga. the effect of different curing methods and water absorption on glass transition temperature and coefficient of thermal expansion and contraction of acrylic denture base material. msc. thesis. college of dentistry /university of baghdad, 2002. 16. morsy ma, aldaous ma. mechanical properties evaluation of new aunp-pmma composite. international review of chemical engineering. 5:1. special section on 4 th ceam. 2012. 17. mccabe jf, wilson hj. the used of differential scanning calorimetry for evaluation of dental materials. j oral rehabil 1980; 1(7): 235-43. 18. katsikis n, franz z, anne h, vital a.thermal stability of pmma/silica nano and microcomposite as investigated by dynamic –mechanical experiments. polymer degradation and stability 2007; 92:1966-76. enas.doc j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 108 histological and immunohistochemical evaluation of the effect of local exogenous application of vegf on bone healing (experimental study in rat) enas fadhil, b.d.s., m.sc. (1) athraa y. alhijazi, b.d.s., m.sc., ph.d. (2) abstract background: the repair of bone defects remains a major clinical orthopaedic challenge. bone is a highly vascularised tissue reliant on the close spatial and temporal connection between blood vessels and bone cells to maintain skeletal integrity. angiogenesis thus plays a pivotal role in skeletal development and bone fracture repair. the role of angiogenic and osteogenic factors in the adaptive response and interaction of osteoblasts and endothelial cells during the multi step process of bone development and repair will be highlighted in this study. this study aimed to identify the role of local exogenous vascular endothelial growth factor in bone healing and to analyze the expression of vegf by immunohistochemistry in created bone defect after application with different biomaterials in a rat model. materials and methods: in this experimental study eighteen male albino rats, weighing (300-400) gram, aged (6-8) months were used and maintained under control conditions of temperature, drinking and food consumption. the animals were subjected for a surgical operation of medial sides of both tibiae bone ( right side was considered as experimental site ,while left be the control one), in control group the bone defect treated with local application of 1µm of normal saline, while experimental treated with local application of 1µm of vegf .the rats were sacrificed at 3,7,10 days after surgery(six rats for each period). bone healing was histologically examined with immunohistochemical localization of vegf results: bone defect treated with local application of vegf shows an early osteoid tissue deposition with high cell count for osteoblast, osteocyte and osteoclast. immunohistochemical evaluation for vegf by stromal cells, reported to be higher with significant difference in vegf group in comparison to control. conclusion: the study illustrated that low application of vegf could be an effective therapeutic expression for bone injuries; these data are promising for a possible future clinical usage. keywords: vascular endothelial growth factor, bone healing, osteogenic factors. (j bagh coll dentistry 2014; 26(4):108-115). introduction skeletal development and fracture repair includes the coordination of multiple events such as migration, differentiation, and activation of multiple cell types and tissues (1). the development of a microvasculature and microcirculation is critical for the homeostasis and regeneration of living bone, without which, the tissue would simply degenerate and die (2). the vasculature provides the necessary factors such as growth factors, hormones, cytokines, chemokines and metabolites needed by the surrounding tissue and acts, when needed, as a barrier to limit the movement of molecules and cells. signals and attractant factors expressed on the bone endothelium help recruit circulating cells, particularly haematopoietic cells to the bone marrow and coordinate with metastatic cells to target them to skeletal regions (3). the vegfs and their corresponding receptors are key regulators in a cascade of molecular and cellular events that ultimately lead to the development of the vascular system, either by vasculogenesis, angiogenesis or in the formation of the lymphatic vascular system (4-6). (1)ph.d. student. department of oral diagnosis, college of dentistry, university of baghdad. (2)professor, department of oral diagnosis, college of dentistry, university of baghdad. although vegfs’ main effects are on endothelial cells, they also bind to vegf receptors expressed on monocytes, neurons, chondrocytes and osteoblasts (7-9). recent studies have shown that the combination of angiogenic and osteogenic factors can stimulate bone healing and regeneration. (10)(11)therefore, the ability to deliver a combined delivery system of growth factors at different rate kinetics locally from biodegradable scaffolds could enhance the reparative mechanism of critical sized bone defects; thus, mimicking the in vivo bone repair conditions. both osteogenesis and angiogenesis are integrated parts of bone growth and regeneration. combined delivery of osteogenic and angiogenic factors is a novel approach in bone regenerative engineering. exogenous addition of vascular endothelial growth factor (vegf) and bone morphogenetic proteins (bmps) together with an osteoconductive scaffold is a very promising method to enhance bone repair (12).therefore the present study was designed to evaluate the local application of exogenous vegf on bone healing. j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 109 materials and methods all experimental procedures were carried out in accordance with the ethical principles of animal experimentation. in this research, eighteen male albino rats, weighing (300-400) gram, aged (6-8) months were used and maintained under control conditions of temperature, drinking and food consumption. materials • vegf165a protein (rat) (ab51967) lyophilised form from abcam company. • polyclonal antibodies of vascular endothelial growth factor antibody (vegf) from abcam company uk (ab46154). methods the animals were subjected for a surgical operation. the surgery was performed under a sterilized condition and gentle technique. every animal was weighted to calculate the dose of general anesthesia that was given to it. the general anesthesia was induced by intra muscular injection of xylazine 2% (0.4 mg/kg b.w.), plus ketamine hcl 50mg (40 mg/kgb.w.) also an antibiotic cover with oxytetracycline 20% (0.7 ml/kg) intramuscular injection was given. both tibiae were shaved and the skin was cleaned with a mixture of ethanol and iodine then a piece of cotton damped with alcohol. incision was made on the lateral side to expose the medial side of the tibia, the skin and fascia flap was reflected. by instrument drilling, and continuous cooling with irrigated saline, a hole of 1.8mm was made with small round bur at a rotary speed of 1500 rpm. following the hole preparation, the operation site was washed with saline solution to remove debris from the drilling site. bone defect was made on both medial sides of right and left tibia bone, as experimental and control sites, respectively. after operation, drying the area by air, then applied1µm vegf in experimental site, while normal saline 1 µm was used for control site. suturing of the muscles was done with absorbable catgut followed by skin suture .the operation site was sprayed with local antibiotic (tetracycline spray). the animals were scarified at intervals 3,7,10 days, using over dose anesthesia. six animals for each period, in each group. bone was removed, and the tibia bone was dissected and fixed in 10% buffered formalin. histological (h&e) and immunohistochemical evaluation was performed under light microscope. assessment of immunohistochemistry results positive reading was indicated when the cells display a brown cytoplasmic stain, while negative reading was indicated for absence of immunereactions depends on positive and negative control. immunohistochemical scoring for positive cells expressed vegf. quantification method of immuno-reactivity was semi-quantitatively estimated the immunestaining score that was calculated as the sum of a proportion score and an intensity score. the proportion score reflects the estimated fraction of positively stained infiltrating cells (score 0, none; score 1, <10%; score 2, 10-50%; score 3, 51-80%; score 4, >80%) (13). statistical analysis for bone cell count and for stromal cells that expressed vegf was estimated by mean, s.d, min., max., f-test, p-value. results a-histological findings 1-for control group at 3 day duration, the group shows bone marrow infiltrated by inflammatory cells with newly formed blood vessels; figure 1. bone healing site for control 7 day duration shows fibrous tissue, with progenitor cell and fibroblast cell; figure 2.at 10 day, trabeculated bone formed and coalesce with cutting bone. osteoblast, osteocyte and reticular cells were showed figure 3. 2for experimental group; bone treated with vegf osteoid tissue filled the bone defect with newly formed blood vessels was illustrated at 3 day ; figures(4&5). trabeculated bone ,coalesce with cutting bone in vegf group 7 days with highly vascular ostoid tissue;figure6. at 10 days new bone with multiple haverssian canal in nearby cutting bone; figure 7. j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 110 figure 1: microphotograph view for control group (3 days) shows progenitor cell (arrow head), inflammatory cell (arrow). h&ex20 figure 2: view for bone healing site (control7 days) shows fibrous tissue (ft) with progenitor cell (arrow head), fibroblast (arrow). h&ex20 figure 3: view for trabeculated bone (tb) coalese with cutting bone (cb) in control group 10 days. h&ex20 figure 4: view for osteoid tissue (ot) filled the bone defect in vegf group at 3 days. h&ex20 figure 5: new blood vessels (arrow heads) in developing osteoid tissue. h&ex40 j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 111 figure 6: trabeculated bone (tb), coalesce with cutting bone (cb) in vegf group 7 days. h&ex20 figure 7: new bone (nb) with multiple haversian canal (hc), in nearly cutting bone (cb) in vegf group 10 days. h&ex20 b-immunohistochemical findings 1-expression of vegf in control group immunohistochemical view for control group at 3 and 7 days period a positive expression of vegf by progenitor cell and endothelial cell were detected in figures 8 & 9.at 10 day duration, the fibroblast cell and active osteocyte cell show positive vegf expression, figure10. figure 8: immunohistochemical view for control group 3 days shows positive expression of vegf by progenitor cell (arrow heads), endothelial cell (arrows). dab stainx40 figure 9: progenitor cells (arrow heads) and endothelial cell (arrows) show positive vegf expression in control group 7 days. dab stainx20 j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 112 figure 10: fibroblast (arrow), active osteocyte (arrow heads) show positive vegf expression in control group 10 days. dab stain x40 2expression of vegf in vegf treated group view for vegf group 3 days shows positive vegf expression by progenitor cells and fibroblast ,figure11.osteoblast ,active osteocyte and osteoclast show positive vegf expression at 7 and 10 day periods, figures 12,13,14. figure 11: immunohistochemical view for vegf group 3 days shows positive vegf expression by progenitor cells (arrow heads) and fibroblast (arrows). dab stainx40 figure 12: osteoblast (arrows) and osteocyte (arrow heads) show positive vegf expression in vegf group 7 days. dab stainx40 j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 113 figure 13: osteoblast (arrow), osteocyte (arrow heads) show positive vegf expression in vegf group at 10 days. dab stainx40 figure 14: osteoclast cell (arrow) show positive vegf expression. dab stainx40 c. statistical analysis statistic analysis for the mean of count of bone cells includes osteoblast, osteocyte and osteoclast in the periods 7 and 10 days, shows that vegf group illustrates a high mean value with highly significant differences in comparison with control group, table (1). for the positive expression of vegf by stromal cells in study groups, statistic analysis demonstrated a high significant value for vegf group in comparison to control and in periods (3, 7 and 10 days) as shown in table 2. table 1: descriptive statistics of the bone cells count (h&e) and groups’ difference in each duration bone cells duration groups descriptive statistics groups’ difference mean s.d. min. max. f-test p-value osteoblast 7 days control 8.75 0.13 8.6 8.9 3140.64 0.000 (hs) vegf 17.23 0.17 17 17.4 10 days control 6.83 0.10 6.7 6.9 25.25 0.000 (hs) vegf 6.85 0.06 6.8 6.9 osteocyte 7 days control 10.80 0.08 10.7 10.9 3108.89 0.000 (hs) vegf 14.25 0.13 14.1 14.4 10 days control 8.68 0.10 8.6 8.8 6762.42 0.000 (hs) vegf 13.13 0.10 13 13.2 osteoclast 7 days control 1.75 0.96 1 3 9.02 0.002 (hs) vegf 1.88 0.10 1.8 2 10 days control 0.70 0.36 0.3 1 8.44 0.003 (hs) vegf 0.19 0.08 0.1 0.3 table 2: descriptive statistics and duration difference of the positive stromal cells expressed by vegf marker groups duration descriptive statistics duration difference mean s.d. min. max. f-test p-value control 3 days 20.43 0.10 20.3 20.5 69771.89 0.000 (hs) 7 days 51.63 0.10 51.5 51.7 10 days 80.45 0.37 80.1 80.9 vegf 3 days 64.43 0.38 64.1 64.8 8046.75 0.000 (hs) 7 days 64.08 0.10 64 64.2 10 days 85.33 0.26 85.1 85.7 j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 114 discussion the present study used exogenous vegf in defect bone related to its ability to couple angiogenesis with bone formation and remodeling. in addition, vegf may act as a central mediator for other factors in promoting bone healing the present study shows an early osteoid deposition in vegf group at 3 day period is related to osteoid tissue formation in bone defect site that includes, stem cells differentiate into osteoblasts that enhanced by vascular endothelial growth factor (vegf) which has been implicated in angiogenesis . as a result, bone deposits via intramembranous ossification 3–7 days after injury period, primarily as osteoid, a nonmineralized bone. goad et al. (14) illustrated that angiogenesis is essential to both normal and pathological bone physiology. at 7 day period vegf group shows bone trabeculae filled a proximately the whole defect in comparison to histologic view for control. this result can be attributed that vegf directly promotes the differentiation of primary osteoblast. (15,16) the present statistics analysis for the mean value of osteoblast, active osteocyte and osteoclast in vegf group were recorded to be a highly significant differences in comparisum to other groups .these findings may be discuss as followings: 1. mechanism of effect of exogenous vegf in bone healing during bone formation and fracture healing there is a cross-talk between endothelial cells and osteoblasts. previous study showed that vascular endothelial growth factor a (vegfa) might be an important factor in this crosstalk, as osteoblast-like cells produce this angiogenic factor in a differentiationdependent manner. moreover, exogenously added vegf-a enhances osteoblast differentiation. (17) 2. vegf also acts to recruit and activate osteoclasts as well as stimulate osteoblast chemotaxis, differentiation, and matrix mineralization. our results implicate vegf in intramembranous ossification. 3. it has suggests that exogenous vegf play an important role in the regulation of bone remodeling by attracting endothelial cells and osteoclasts and by stimulating osteoblast differentiation. 4. formation of new capillaries, a critical component of tissue growth and repair, is a recognized process in the development, formation, and remodeling of bone. vascular endothelial growth factor (vegf), a potent angiogenic factor with specific mitogenic actions on endothelial cells, is produced in a regulated manner by many cell types, including osteoblasts (18). the present result shows positive expression of vegf by bone marrow stromal cells, adipocytes, mesenchymal stem cells, precursor endothelial cells, and bone cells include osteoblasts and active osteocytes in different periods in all groups but in different score. therefore, our primarily data provide evidence that vegf activity is essential for appropriate bone formation and mineralization in response to injury. carano and filvaroff (19) reported that the intimate connection, both physical and biochemical, between blood vessels and bone cells has long been recognized. genetic, biochemical, and pharmacological studies have identified and characterized factors involved in the conversation between endothelial cells (ec) and osteoblasts (ob) during both bone formation and repair. references 1. colnot c, romero dm, huang s, helms ja. mechanisms of action of demineralized bone matrix in the repair of cortical bone defects. clin orthop relat res 2005; 435: 69-78. 2. schmid j, wallkamm b, hammerle ch, gogolewski s, lang np. the significance of angiogenesis in guided bone regeneration. a case report of a rabbit experiment. clin oral implants res 1997; 8: 244-8. 3. brandi ml, collin-osdoby p. vascular biology and the skeleton. j bone miner res 2006; 21: 183-92. 4. tammela t, enholm b, alitalo k, paavonen k. the biology of vascular endothelial growth factors. cardiovasc res 2005; 65: 550-63. 5. ferrara n, gerber hp. the role of vascular endothelial growth factor in angiogenesis. acta haematol 2001; 106: 148-56. 6. rossant j, howard l signaling pathways in vascular development. annu rev cell dev biol 2002; 18: 541 73. 7. 7-ferrara n, gerber hp, lecouter j. the biology of vegf and its receptors. nat med. 2003; 9: 669-76. 8. storkebaum e, carmeliet p vegf: a critical player in neurodegeneration. j clin invest 2004; 113: 14-18. 9. bluteau g, julien m, magne d, mallein-gerin f, weiss p, daculsi g, guicheux j vegf and vegf receptors are differentially expressed in chondrocytes.bone. 2007; 40: 568-76. 10. geiger f, bertram h, berger i, lorenz h, wall o, eckhardt c, simank hg, richter w vascular ndothelial growth factor gene-activated matrix (vegf165-gam) enhances osteogenesis and angiogenesis in large segmental bone defects. j bone miner res 2005; 20: 2028-35. 11. peng h, usas a, olshanski a, ho am, gearhart b, cooper gm, huard j vegf improves, whereas sflt1 inhibits, bmp2-induced bone formation and bone j bagh college dentistry vol. 26(4), december 2014 histological and oral diagnosis 115 healing through modulation of angiogenesis. j bone miner res. 2005; 20: 2017-27. 12. cui q, dighe as, irvine jn jr.combined angiogenic and osteogenic factor delivery for bone regenerative engineering. curr pharm des 2013; 19(19): 3374-83. 13. suzuki s, dobashi y, hatakeyama y, tajiri r, fujimura t, heldin ch, ooi a. clinicopathological significance of platelet-derived growth factor (pdgf)b and vascular endothelial growth factor-a expression, pdgf receptor-β phosphorylation, and microvessel density in gastric cancer. bmc cancer. 2010; 30(10): 659. 14. goad dl, rubin j, wang h, tashjian ah jr, patterson c.enhanced expression of vascular endothelial growth factor in human saos-2 osteoblast-like cells and murine osteoblasts induced by insulin-like growth factor i. endocrinol 1996;137(6): 2262-8. 15. deckers mm, van bezooijen rl, van der horst g, hoogendam j, van der bent c, papapoulos se, löwik cw.bone morphogenetic proteins stimulate angiogenesis through osteoblast-derived vascular endothelial growth factor a. endocrinol 2002; 143(4): 1545-53. 16. 16-saadeh pb, mehrara bj, steinbrech ds, dudziak me, greenwald ja, luchs js, spector ja, ueno h, gittes gk, longaker mt.transforming growth factor-beta1 modulates the expression of vascular endothelial growth factor by osteoblasts. am j physiol 1999; 277(4 pt1): c628-37. 17. 17-mandracchia vj, nelson sc, barp ea. current concepts of bone healing. clin podiatr med surg 2001; 18(1): 55–77. 18. athanasopoulos an, schneider d, keiper t, alt v, pendurthi ur, liegibel um, sommer u, et al. vascular endothelial growth factor (vegf)-induced up-regulation of ccn1 in osteoblasts mediates proangiogenic activities in endothelial cells and promotes fracture healing. j biol chem 2007; 282(37): 26746–53. 19. carano ra, filvaroff eh. angiogenesis and bone repair. drug discov today 2003: 8: 980-980. nada final.doc j bagh college dentistry vol. 26(3), september 2014 gingival health in orthodontics, pedodontics and preventive dentistry 156 gingival health in relation to salivary vitamin c and total protein among dental students nada j.m.h. radhi, b.d.s., m.sc., ph.d. (1) abstract background: the protective roles of vitamin c and total proteins in gingival inflammation were reported by several studies. the aim of this study was to measure the concentration of salivary vitamin c, total protein and their relation to gingival health among dental students. materials and methods: the sample consisted of 67 dental students (33 males and 34 females) from college of dentistry, university of baghdad. sillness and löe (1964) was used for recording of dental plaque, while the gingival index (gi) was measured according to löe and sillness criteria (1963). stimulated salivary samples were collected and chemically analyzed in poisoning center/surgical specialty hospital by using colorimetric method to measure the salivary vitamin c and total protein. spss version 18 was used for analyzing data. results: a higher percentage of dental students were found with mild type of gingivitis. higher mean value of salivary vitamin c was reported among dental students with mild type of gingival index compared to those with moderate type, while the opposite picture was noticed for total protein, differences were statistically significant (p< 0.05). conclusion: significant associations between salivary vitamin c, total protein and gingivitis were found in the present study. the protective rule of salivary vitamin c and total protein may offer a route to improve oral healthcare. key words: gingival disease, vitamin c, total protein, periodontal disease, healthy individuals. (j bagh coll dentistry 2014; 26(3):156-159). الخالصة الكل ي ف ي اللع اب وعالقتھم ا بص حة الھدف من ھذه الدراسة ھو لقی اس تركی ز فیت امین ج والب روتین . للفیتامین ج والبروتینات الكلیة في التھاب اللثةسجلت دراسات عدیدة الدور الوقائي .اللثة لدى طلبة طب االسنان دلی ل اللویح ة الجرثومی ة اس تخدم مؤش ر ). ثالث ة وثالث ون ذك ر واربع ة وثالث ون انث ى (جامع ة بغ داد /تكونت العین ة م ن س بعة وس تین طال ب م ن طلب ة كلی ة ط ب االس نان : المواد والطرق )sillness and löe, 1964( لتصنیف م مؤشر اللثة تبعا ، بینما استخد)3löe and sillness, 196 .( مستش فى /تم جمع عینات من اللعاب المحفز وحلل ت كیمیائی ا ف ي مختب ر الس موم .spss 18حللت البیانات احصائیا باستخدام .والبروتین الكلي) ج(لقیاس فیتامین ) colorimetric method(الجراحات التخصصیة باستخدام ف ي اللع اب مقارن ة ال ى ال ذین ل دیھم التھ اب اللث ة ) ج(ان النسبة العالیة من طلبة طب االسنان مصابین بالتھاب اللث ة الخفی ف، كم ا س جل ل دیھم ارتف اع قیم ة متوس ط فیت امین وجد: النتائج .بینما لوحظ العكس للبروتین الكلي، مع فروق معنویة احصائیا. المتوسط ال ى العنای ة الطری ق والب روتین الكل ي ربم ا یك ون ) ج(لفیت امین ان ال دور الوق ائي . ، البروتین الكلي والتھ اب اللث ة )ج(ت معنویة واضحة بین فیتامین وجدت ھذه الدراسة عالقا :الخالصة .بصحة الفم introduction periodontal disease is associated with increased oxidative modification of salivary dna, lipids, and proteins (1). gingivitis and periodontitis are oral diseases that are characterized by chronic inflammation. salivary protein and albumin concentrations were determined as markers for plasma protein leakage, occurring as a consequence of the inflammatory process (2). saliva possesses a wide range of antioxidants including uric acid, vitamin c, proteins, reduced glutathione, oxidized glutathione, and others (3). such antioxidants work in concert, and total antioxidant capacity may be the most relevant parameter for assessing the defense capabilities (4). periodontitis has been recognized as a risk factor for certain systemic diseases where low-grade inflammation within the peripheral circulation is associated with the etiology or progression of the disease. these manifestations of increased oxidative stress provide potential mechanisms whereby periodontal inflammation may impact upon systemic inflammatory status (5). vitamin c has long been a candidate for modulating perio (1)assistant professor, department of pediatric and preventive dentistry, college of dentistry, university of baghdad. dontal disease. studies of effects of vitamin c on extracellular matrix and immunologic and inflammatory responses provide a rationale for hypothesizing that vitamin c is a risk factor for periodontal disease (6). once the teeth are fully formed, vitamin deficiencies which cause gum damage, i.e. lack of vitamin c, will cause tooth loss (7). no iraqi study was noticed among dental students that searched the relation between salivary vitamin c, total proteins and gingival disease, therefore, this study was conducted. materials and methods the sample was chosen from college of dentistry, university of baghdad comprised of 67 dental students (33 males and 34 females) aged 22 years old. plane mouth mirror and periodontal probe were used. dental plaque (pi) recorded (8) by the criteria described by sillness and löe. the gingival index (gi) of löe and sillness used (9) for the assessment of gingival health, the whole teeth was examined and four surfaces of each tooth were scored. each student was asked to chew a piece of arabic gum (0.5-0.7 gm) for 5 minutes for collection of whole stimulated saliva in a sterile capped bottle using a standardized method (10). j bagh college dentistry vol. 26(3), september 2014 gingival health in orthodontics, pedodontics and preventive dentistry 157 level of vitamin c (mg/dl) in saliva was determined photometrically with 2, 4dinitrophenyl hydrazine (dnph) to form red bishydrazone (11). total protein (mg/dl) determined by colorimetric method. a ready kit was used by labkit, nau j. protein react in acid solution with pirogallol red and molybdate to form a colored complex. the intensity of the color formed is proportional to the protein concentration in the sample (12). the values of this study were subjected to statistical analysis by spss version 18 (statistical package for social sciences) to specify the statistical differences between the groups. mean and sd and the parametric statistical tests of significance were used. the independent samples t-test was used to test the statistical significance of difference in mean between groups of study. the linear correlation between two quantitative variables is measured by spearman's rank linear correlation coefficient, while multiple linear regression was used to assess independent effect of explanatory variables on dependent quantitative variable. the confidence limit was accepted at 95%. results table (1) shows the distribution of the total sample by gender. the sample was consisted of males and females as a higher percentage of females were noticed compared to males. table 1: the distribution of total sample (dental students) according to gender gender no. % male 33 49.25 female 34 50.75 total 67 100 table (2) demonstrates the mean values of plaque index, gingival index, salivary vitamin c and total protein (mg/dl) of total sample. the mild type of plaque and gingival indices was represented a minimum score while the maximum score was recorded of moderate type. table 2: oral indices and salivary variables (mean±sd) of the total sample (dental students). indices and variables no. min. max. mean ±sd pli 67 0.20 1.92 0.62 0.49 gi 67 0.14 1.90 0.59 0.49 vitamin c (mg/dl) 67 0.05 0.08 0.061 0.007 total protein (mg/dl) 67 0.18 0.29 0.261 0.018 table (3) represents the mean values of salivary vitamin c and total protein following the severity of gingival index among dental students. the severe type of gingival index was not found among dental students, only mild and moderate types were noticed. higher mean value of salivary vitamin c was recorded among dental students with mild type of gingival index compared with students with moderate gingivitis, differences were statistically significant (t= 2.342, df= 65, p< 0.05). while total protein was noticed in higher mean value among dental students with moderate gingivitis, differences were statistically significant (t= -2.192, df= 65, p< 0.05). table 3: the mean values of salivary vitamin c and total protein following the severity of gingival index among dental students gingival index severity no. % vitamin c total protein mean ±sd mean ±sd mild (0.1-1) 50 74.63 0.062 0.007 0.258 0.015 moderate (1.1-2) 17 25.37 0.058 0.003 0.270 0.024 table (4) demonstrates the correlation between pi, gi with salivary vitamin c and total protein among dental students. strong negative highly significant correlations were found between pi, gi with salivary vitamin c. while positive highly significant correlation with total protein. a strong positive highly significant correlation was recorded between pi with gi (r= 0.99, p< 0.001). table 4: correlation coefficient between plaque index, gingival index with salivary vitamin c and total protein among dental students variables pi gi r p r p vitamin c -0.509 <0.001** -0.522 <0.001** total protein 0.432 <0.001** 0.431 <0.001** ** highly significant j bagh college dentistry vol. 26(3), september 2014 gingival health in orthodontics, pedodontics and preventive dentistry 158 table (5) represents the multiple linear regressions of gi with plaque index and salivary variables. for each one unit increased in plaque index (pi), the gingival index (gi) increase significantly by 0.991. the model was statistically significant and being able to explain 99% of variation in the gingival index (gi). table 5: multiple linear regressions of gingival index (gi) with salivary variables and plaque index variables partial regression coefficient standardized coefficient p-value vitamin c -1.731 -0.025 0.051 total protein -0.290 -0.011 0.364 pi 0.991 0.989 0.000** p (model) < 0.001 r2= 0.99 **highly significant discussion in the present study mild and moderate type of gingivitis were affected dental students while severe type was not noticed this finding due to the careness of dental students for their oral health as well as the oral cleanliness by the use of oral hygiene measures. the study reported a positive strong highly significant correlation between gingival inflammation and plaque index. dental plaque is the main local factor related to the variation in the prevalence of periodontal disease (13). this finding was also reported by iraqi studies and other studies in the world (14-18). the study revealed a higher mean value of vitamin c among dental students with mild type of gingivitis compared to those with moderate type, as a negative highly significant correlation was recorded with plaque and gingival index. this finding was also reported by other studies (19-21). as the most effective physiological antioxidant, vitamin c may also generate a disadvantageous environment for the optimal growth and survival of p. gingivalis. accordingly, it is possible that an extremely low vitamin c concentration may increase colonization of p. gingivalis, but it is also conceivable that it disturbs the healing of the periodontal tissues. since the major function of ascorbic acid is its involvement in the synthesis of collagen fibers, a very low vitamin c status may prevent the regeneration of periodontal tissues. however, the attachment ligaments or alveolar bone lost due to the inflammation response will not be revived (22-25). salivary total protein is a vital component of saliva, with salivary proteins, predominantly comprising proline rich proteins, mucin, amylase, immunoglobulins, statherin and antibacterial factors, and these are responsible for most of the functions of saliva (26). the present study recorded a positive highly significant correlation between total protein with plaque and gingival index as a higher mean value was noticed among dental students with moderate type of gingivitis. the same findings were recorded by other studies (2,21,27,28). in general, the major factors affecting the protein concentration and composition of whole saliva are the salivary flow rate, protein contributions of the glandular saliva and crevicular fluid proteins. thus, the elevated protein levels are most likely due to enhanced synthesis and secretion by the individual glandular saliva. also, glandular-derived proteins, cystatin c and amylase showed significant rise in periodontitis subjects, proving the glandular origin of these proteins (29). reactive oxygen species (ros) are implicated in the destruction of the periodontium during periodontitis. the imbalance in oxidant activity may be a key factor and the elevated level of total proteins may provide a protective rule against reactive oxygen species (ros) (1,30,31). the present study concluded that the protective rule of salivary vitamin c and total protein may offer a route to improve oral healthcare. references 1. su h, gornitsky m, velly am, yu h, benarroch m, schipper hm. salivary dna, lipid, and protein oxidation in nonsmokers with periodontal disease. free radic biol med 2009; 46(7): 914-21. 2. shaila m, prakash pai g, and shetty p. salivary protein concentration, flow rate, buffer capacity and ph estimation: a comparative study among young and elderly subjects, both normal and with gingivitis and periodontitis. indian soc periodontol 2013; 17(1): 42– 6. 3. halliwell b. reactive oxygen species in living systems: source, biochemistry, and role in human disease. am j med 1991; 91:14s–22s. 4. brock gr, butterworth cj, matthews jb, chapple il. local and systemic total antioxidant capacity in periodontitis and health. j clin periodontol 2004; 31:515–21. 5. chapple il, brock g, eftimiadi c, matthews jb. glutathione in gingival crevicular fluid and its relation to local antioxidant capacity in periodontal health and disease. mol pathol 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(1) manhal abdul-rahman majeed, b.d.s., m.sc., ph.d. (2) abstract background: this study was conducted to assess the effect of sonic activation and bulk placement of resin composite in comparison to horizontal incremental placement on the fracture resistance of weakened premolar teeth. materials and method: sixty sound human single-rooted maxillary premolars extracted for orthodontic purposes were used in this study. teeth were divided into six groups of ten teeth each: group 1 (sound unprepared teeth as a control group), group 2 (teeth prepared with mod cavity and left unrestored), group 3 (restored with sonicfill™ composite), group 4 (restored with quixfil™ composite), group 5 (restored with tertic evoceram® bulk fill composite) and group 6 (restored with universal tetric evoceram® composite using horizontal incremental layering technique). standardized class ii mod cavity was prepared in all teeth except (group 1).after finishing the restorative procedure of each group according to the manufacturer's instructions, all teeth were stored in deionized distilled water in an incubator at 37°c for seven days.all specimens were subjected to compressive axial loading until fracturein a universal testingmachine.specimens were examined by a stereomicroscope at a magnification of (20x) to evaluate the mode of fracture . results: the results of this study revealed that the control group exhibited the highest fracture resistance compared to all prepared teeth groups (restored or unrestored) and the differences were statistically highly significant (p<0.01), except with group 3 (which was restored with sonicfill™ composite) where the difference was statistically significant only (p < 0.05).additionally the results of this study revealed that the prepared unrestored teeth (group 2) exhibited the lowest fracture resistance compared to all restored groups and the differences were statistically highly significant (p<0.01). meanwhile, among the restored teeth groups, teeth restored with sonicfill™ composite (group 3) exhibited the highest fracture resistance as compared with all other restored groups and the difference was statistically highly significant (p<0.01) .on the other hand, no statistically significant differences in fracture resistance were found among groups 4, 5 and 6, which were restored with quixfil™ composite, tetric evoceram® bulk fill composite and universal tetric evoceram® composite, respectively (p > 0.05). group 3and group 5 showed mostly mixed mode of failure, while group 4 showed mostly adhesive mode of failure. on the other hand group 6 teeth showed different modes of failure. conclusions: sonicfill™ composite can be considered as a viable treatment modality for the restoration of weakened maxillary premolar teeth. on the other hand, the time-consuming incremental layering technique can be substituted with bulk filling, using bulk fill materials (quixfil™ and tetric evoceram® bulk fill) for reinforcement ofweakened maxillary premolars. key words: fracture resistance, sonicfill™, bulk fill technique, incremental layering technique. (j bagh coll dentistry 2014; 26(4):22-27). introduction `````unresolved controversy exists concerning the preferred restorative materials and techniques used to restore weakened maxillary premolars to improve their resistance to fracture under occlusal load (1).the evolution of composite materials and adhesive techniques has considerably changed the approach to restorations in the posterior area. the advantages of adhesive restorations are not only of an aesthetic nature, but, above all, relate to the possibilities of conserving a greater amountofhealthy tissue and “reinforcing” the residual dental structure (2).it is obvious that dentists have always been looking for a fast and reliable filling technique allowing the reduction of layers, effort and time. (1) master student, department of conservative dentistry, college of dentistry, university of baghdad. (2)assist.prof., department of conservative dentistry, college of dentistry, university of baghdad. in an attempt to reduce some of the time and effort needed for layering and adaptation when placing posterior composites, new materials have been introduced and termed "bulk fill" materials (3). most of these products such as surefil™ sdr (dentsply caulk), x-trafil (voco, cuxhaven, germany), venus® bulk fill (heraeuskulzer) and filtek™ bulk fill flowable restorative (3m espe) are based on a low viscosity composite, and are applied in a bulk layer of 4mm thickness and light cured, then another composite is used to fill the rest of thecavity. this makes the restorative procedure longer and more complex; therefore, these materials should not be classified as true "bulk fill" materials (4). more recently, true "bulk fill" composite resin materials have been introduced such as quixfill™ posterior restorative (dentsply) and tetric evoceram® bulk fill j bagh college dentistry vol. 26(4), december 2014 fracture resistance restorative dentistry 23 (ivoclar vivadent). quixfill™ posterior restorative offers an extremely high filler load (66% by volume and 86% by weight) and it offers a complete 4mm cure in as little as 10 seconds, while still offering a prolonged working time to allow creation of pre-cure anatomy (5). on the other hand, tetric evoceram® bulk fill material is another bulk fill material which can also be placed in increments of up to 4 mm and can achieve high marginal adaptation to the floor and walls of cavity preparation, eliminating the need for a flowable liner as reported by the manufacturer (6). very recently, kerr and kavo, after three years of a common development project, launched the sonicfill™ system for posterior restorations. the system consists of a hand piece activated sonically and a special composite formulation, which contains about 83.5% of fillers by weight, mainly silica and barium aluminoborosilicate glass. upon activation, the sonic energy lowers the viscosity of the composite and extrudes the composite that has initially a thick consistency. the viscosity change of the composite will ensure a perfect adaptation to the cavity walls and avoids the stickiness of the composite to the instrument. it is not necessary to condense the composite because the high frequency vibration yields intimate adaptation to the cavity walls without voids inclusion. cavities up to 5 mm of depth are filled in one bulk increment. upon deactivation of the sonic energy, the viscosity of the composite increases and allows easy adaptation and accurate sculpting morphology of the composite. sonicfill system is indicated for posterior restorations in class i and ii and as a buildup material for cusp reconstruction as well as a base after root canal treatment (4). materials and methods sample selection sixty sound human single-rooted maxillary premolar teeth, extracted for orthodontic purposes from patients with agerange from 18-22 yearscollected from different health centers, were used in this study.teeth were stored in0.1%thymol solution for 48 hours (6), then in deionized distilled water at room temperature (7). only sound teeth free from cracks and with regular occlusal anatomy and approximately similar crown size were selected (8). for each tooth, the maximum bucco-lingual and mesiodistal dimensions and inter-cuspal distance were measured using a digital caliper (9). the measured dimensions varied with a maximum deviation of not more than 10% from the determined mean. these measurements were used in the distribution of the teeth among the different groups to provide uniformity of tooth size in each group (10). teeth mounting to simulate the periodontal ligament, root surfaces were marked 2 mm below the cementoenamel junction cej and covered with a 0.6 mm thick foil (adapta foil, bego, germany)(11). each tooth was embedded in a block of self-cured acrylic resin (veracril, colombia) in a rubber mold cylinder (2.5cm width-3cm height). the teeth were embedded along their long axes using a dental surveyor. after the first signs of polymerization, teeth were carefully removed manually from the resin blocks (12).the acrylic covered the roots to within 2 mm of the cej, to approximate the support of alveolar bone in a healthy tooth (13). in order to simulate the periodontal ligament, the adapta (foil) was removed from the root surface and light body addition silicone impression material (express™, 3m espe, usa) was injected into the acrylic resin blocks in the site that was previously occupied by the tooth root and adapta foil, and the tooth was reinserted into the resin block. a standardized silicone layer that simulated periodontal ligament was thus created taking the thickness of the foil (11). sample grouping the teeth were randomly divided into six groups of ten teeth each according to the type of restorative material used as follows: group1: this group comprised ten sound unprepared teeth that served as a control group. group 2: an extensive class ii mod cavity was prepared, but the cavity was left unrestored. group 3: the mod cavity was restored with sonicfill™ composite (kerr corp., usa). group 4: the mod cavity was restored with quixfil™ bulk fill composite restorative material (dentsply detrey gmbh, germany). group 5: the mod cavity was restored with tetric evoceram® bulk fill composite restorative material (ivoclarvivadent, liechtenstein). group 6: the mod cavity was restored with universal tetric evoceram®composite restorative material (ivoclarvivadent, liechtenstein), using horizontal incremental layering technique. after the random distribution of the teeth into the six experimental groups, statistical analysis using one-way anova test was done among the groups for the bucco-lingual and mesio-distal dimensions and for the inter-cuspal distance to assure that there were no statistically significant differences among the groups concerning crown dimensions. j bagh college dentistry vol. 26(4), december 2014 fracture resistance restorative dentistry 24 cavity preparation mesio-occluso-distal (mod) cavities were prepared in all specimens using a flat-ended diamond fissure bur (4mm cutting height, 1mm diameter) in a high speed turbine handpiece with water coolant that was fixed to a modified dental surveyor, except for group 1, which served as a control. the width of the cavity was standardized 3mm, which approximates one half of the intercuspal distance and one third of the bucco-palatal dimension. the depth of the cavity was 3mm at the pulpal floor level and 4mm at the gingival seat level measured from the palatal cavo-surface margin, with 1mm depth of the axial wall.the buccal and palatal walls of the cavity were prepared parallel to each other(14, 15, 16). the cavity dimensions used in this study are shown in figure1. figure 1: diagram showing the dimensions of the mod cavity preparation. before preparation of the teeth, an outline of the cavity was drawn with a super color marker (17). tooth preparation was carried out with aid of modified dental surveyor in order to standardize the cavity preparation.teeth showing pulpal exposure after preparation were discarded (10).the depth of the cavity was checked with a graduated periodontal probe and the width of the cavity was checked using a digital caliper (18). adhesive procedure supermat® adapt®supercap® matrix system (kerr corp.)was used in this study and changed for each restoration.single bond universal adhesive (3m espe) was usedfor groups 3 to 6 prior to composite resin placementwith the selfetch technique following the manufacturer's instructions and light cured with a led light curing unit with a light intensity of 600 mw/cm2 (woodpecker® led.c wireless curing light) for 10 seconds according to the manufacturer's instructions. restorative procedure the three bulk fill composite materials sonicfill™(kerr corporation, usa), quixfil™ compositematerial (dentsply detrey gmbh)and tetric evoceram® bulk fill composite material (ivoclarvivadent, liechtenstein) were applied to the cavity in a single bulk increment of 4mm according to the manufacturer’s instructions. comporoller™ was used to compress the material, adapting the margins; removing the excessand sculpting anatomy. each restoration was then light cured for 20 seconds according to the manufacturer's instructions. additional light curing from the buccal and palatal sides for 20 seconds was done according to the manufacturer's recommendation. group 6 was restored with universal tetric evoceram® composite using horizontal incremental technique. the cavity was filled with two increments of 2 mm each since the total depth of the cavity was 4 mmusing comporoller™ instrument, followed by light curing for 20 seconds from occlusal direction according manufacturer’s instructions.afterfinishing the restorative procedure, all teeth were stored in deionized distilled water in an incubator at 37°c for seven days before testing (31). mechanical testing all specimens were subjected to compressive axial loading until fracture in a computercontrolled universal testing machine (laryee, china) with a crosshead speed of the 0.5 mm/minute. the load was applied parallel to the long axis of the teeth using a steel bar 8 mm in diameter, touching the occlusal surface of the tooth at the slopes of the cusps rather than the restoration (15). all samples were loaded until fracture and the maximum breaking loads were recorded in kn. the mode of failure was evaluated under a stereomicroscope (altay biovision line, italy) at a magnification of (20 x).the mode of failure was recorded and classified as adhesive, cohesive and mixed modeof failure (13). results the descriptive statistics of fracture resistance of all groups with the percentage of increase in fracture resistance are shown in table 1. one-way anova test revealed a statistically highly significant difference among the groups as shown in table 2. further comparisons among groups were done using the least significant difference test (lsd test) to see where the significant difference occurred as shown in table 3. j bagh college dentistry vol. 26(4), december 2014 fracture resistance restorative dentistry 25 the results of this study revealed that the control group exhibited the highest fracture resistance compared to all prepared teeth groups (restored or unrestored) and the differences were statistically highly significant (p<0.01), except with group 3 (which was restored with sonicfill™ composite) were the difference was statistically significant only (p < 0.05 .) additionally the results of this study revealed that the prepared unrestored teeth (group 2) exhibited the lowest fracture resistance compared to all restored groups and the differences were statistically highly significant (p<0.01). among the restored teeth groups, teeth restored with sonicfill™ composite (group 3)exhibited the highest fracture resistance as compared with all other restored groups and the difference was statistically highly significant (p<0.01 .) on the other hand, no statistically significant differences in fracture resistance were found among groups 4, 5 and 6, which were restored with quixfil™ composite, tetric evoceram® bulk fill composite and universal tetric evoceram® composite, respectively (p>0.05). concerning the fracture mode, group 3 and group 5 showed mostly mixed mode of failure, while group 4 showed mostly adhesive mode of failure. on the other hand, group 6 showed different modes of failure. table 1: descriptive statistics of fracture resistance of each group in kn percentage of increase in fracture resistance sd mean groups 100% 0.094 1.18250 group1 53%* 0.029 0.55633 group 2 90.7% 0.110 1.0726 group 3 74.8% 0.079 0.88533 group 4 72.3% 0.046 0.855 group 5 75.85% 0.048 0.897 group 6 *percentage of decrease in fracture table 2: one-way anova test for comparison of significance among different groups sum of squares df mean square f sig. between groups 1.377 5 0.275 50.062 .000 (hs) within groups 0.165 30 0.006 total 1.543 35 table 3: lsd test between the different groups groups mean difference s.e. sig. g 1 g2 .626167* .042829 .000 (hs) g 3 .109833* .042829 .016 (s) g 4 .297167* .042829 .000 (hs) g 5 .327500* .042829 .000 (hs) g 6 .285500* .042829 .000 (hs) g 2 g 3 -.516333* .042829 000 (hs) g4 -.329000* .042829 .000 (hs) g5 -.298667* .042829 .000 (hs) g6 -.340667* .042829 .000 (hs) g 3 g4 .187333* .042829 .000 (hs) g 5 .217667* .042829 .000 (hs) g6 .175667* .042829 .000 (hs) g 4 g5 .030333 .042829 .484 (ns) g6 -.011667 .042829 .787 (ns) g 5 g 6 -.042000 .042829 .335 (ns) * the mean difference is significant at the 0.05 level. discussion````` the highest fracture resistance mean value presented by the intact teeth (group 1) could be attributed to the presence of intact palatal and buccal cusps with intact mesial and distal marginal ridges which form a continuous circle of dental structure, reinforcing the tooth and maintaining its integrity (19).this is in agreementwith santos and bezzera (20). in this study, the lowest fracture resistance mean value presented by the prepared unrestored teeth which was statistically highly significant when compared with all other groups could be attributed to thetype and quality of the remaining tooth structure after mod cavity preparationas teeth with large mod cavities are severely weakened due to the loss of the reinforcing tooth structures,specially the cuspsand marginal ridges, so become more susceptible to fracturethis is also in agreement with santos and bezzera (20). in this study, it is clearly seen that all composite resin restored teeth displayed higher fracture resistance than the prepared but unrestored teeth (group 2) regardless of the type of composite material used and with varying percentages of increase in fracture strength as shown in table 1.this could be due to the micromechanical bonding between the adhesive system and the tooth structure and hybrid layer formation which tend to bind the walls of the cusps together and strengthen the remaining tooth structure (21). among the restored groups, group 3 (which was restored with sonicfill™ composite) showed the highest fracture resistance mean value and the highest percentage of increase in fracture j bagh college dentistry vol. 26(4), december 2014 fracture resistance restorative dentistry 26 resistancewith statistically highly significant difference as compared with all other restored groups. this could be attributed to the followings: 1. better adaptation of sonicfill™ composite to the cavity walls owing to its fluctuating viscosity as a result of sonic activation delivered through the sonicfill™hand piece. sonic activation lowers the viscosity of the sonicfill™ composite dramatically, up to 87%, which is related to special rheological modifiers that react to sonic activation delivered through the sonicfill™ hand piece during its placement, increasing its flowability and providing superior adaptation to the cavity walls, and thus making the frequency and size of critical voids located at the margin and along line angles of the cavity less pronounced compared to conventional putty-like composites (22). 2. better mechanical properties of sonicfill™ composite as compared with the other compositematerials (quixfil™composite, tetric evoceram® bulk fill compositeand universal tetric evoceram®composite) including higher compressive strength, higher flexural strength and higher fracture toughness and fracture work, with an intermediate flexural modulus between quixfil™ and tetric evoceram® bulk fill(24,25,26).such differences in the mechanical properties among the three different bulk fill materials used in this study could be attributed to the differences in the type and size of fillers and the difference in filler loading. on the other hand, the statistically nonsignificant differencesinfracture resistance among group 4, group 5&group 6 even though quixfil™ composite has higher filler loading than the universal and bulk fill versions of tetric evoceram® composite could be due to that quixfil™ composite is a microhybrid composite, while the other two composite materials are nanohybrid composites, and hence nanotechnology might have compensated the effect of higher filler loading of quixfil™ resulting in statistically non-significant differences in fracture resistance. concerning the fracture mode, group 3 (sonicfill™group) showed mostly mixed type of failure (80%) (cohesive type in restoration within the upper part of the restoration and adhesive type in the remaining part).this could be attributed to the following: 1. proper adaptation of the material to cavity walls without void formation owing to its fluctuating viscosity combined with the low shrinkage and contraction stress upon curing of bonded sonicfill™ composite.low contraction stressreduced the possibility of the composite pulling away from the tooth surface during polymerization with subsequently low cuspal deflection. 2.high mechanical properties of sonicfill™ (especially its high fracture toughness and fracture work), which made the material able to absorb the applied load and preserve the toothrestorationinterface, up to the point at which the applied load exceeded the fracture toughness limit of the material, thus underwent cohesive failure in the upper part of the restoration and lost its ability to transmit the applied load and preserve the tooth-restoration interface, hence underwent adhesive type of failure. 3. another possible contributing factor for this finding might be the high bond strength of single bond universal adhesive to enamel (28). group 4 (quixfil™group) showed mostly adhesive type of failure (90%). this may be attributed tothe heavy viscosity of quixfil™ composite, which might hindered the appropriate adaptation of the material to the cavity walls, resulting in void formation at the tooth restoration interface (23). on other hand the high flexural modulus of quixfil™ composite as a result of its high filler loading might not allowed the material to absorb the applied load and undergo plastic deformation; instead, the increased stresses from theapplied load were transferred to the toothrestoration interface, resulting in adhesive type offailure before the material would fail mechanically (29). also the resin matrix of quixfil™ composite serves to give the resin mixture a high cohesion (30). group 5 (tertic evoceram® bulk fill group) showed mostly mixed mode of failure (80%). this could be attributed to the low shrinkage stress of tertic evoceram® bulk fill composite according to manufacturer's information.this is in agreement with van ende et al. (27), who found that for materials with low shrinkage stress, mixed failure was the predominant type of failure rather than de-bonding with subsequent adhesive failure. this is also in agreement with el gezawi et al. (29) who found that most failures of bulk fill composites were mixed. group 6 showed cohesive type of failure in 50%, adhesive type of failure in 30% and the other 20% showed mixed type of failure. this finding might be due to the incorporation of voids or contamination between composite layers. voids developed from resin porosity contain oxygen and form polymerization inhibiting zone resulting in bond failures between increments (31). sonicfill™ composite can be considered as a viable treatment modality for restoration of weakened teeth. it is obvious that dentists have j bagh college dentistry vol. 26(4), december 2014 fracture resistance restorative dentistry 27 always been looking for a fast and reliable filling technique allowing the reduction of layers, effort and time; therefore, the time-consuming incremental layering technique can be substituted with the bulk fill technique using bulk fill materials (quixfil™ and tetricevoceram® bulk fill) for reinforcement of weakened teeth. refrences 1. taha na, palamara je, messer hh. fracture strength and fracture patterns of root filled teeth restored with direct resin restorations. dent mater 2011; 39: 527-35. 2. giachetti l, scaminaci russo d, bambi c, grandini r. a review of polymerization shrinkage stress: current techniques for posterior direct resin restorations. j contemp dent pract 2006; 7(4): 79-88. 3. jackson r. efficient core build-up for endodontic teeth using a sonic activated composite resin. dent today 2013. 4. sabbagh j. sonicfill system: a clinical approach 2013. 5. dentsply detrey gmbh. quixfil™ direct posterior restoration: scientific documentation 2011. 6. ivoclar vivadent, tetricevoceram® bulk fill: the bulk composite without compromises. scientific documentation. schaan, liechtenstein 2013. 7. jacinta mm, santos v, barroso r. fracture resistance of maxillary premolars restored with direct and indirect adhesive techniques. j canad dent assoc 2005; 71(8):585. 8. mortazavi v, fathi m, katiraei n, shahnaseri s, badrian h, khalighinejad n. fracture resistance of structurally compromised and normal endodontically treated teeth restored with different post systems: an in vitro study. j dent res 2012; 9(2):185–91. 9. soares cj, matins lr, fonseca rb, corrersobrinho l, fernandes-neto aj. influence of cavity preparation design on fracture resistance of posterior leucitereinforced ceramic restorations. j prosthet dent 2006; 95:421-29. 10. shabayek nm, hassan fm, mobarak eh. effect of using silorane-based resin composite for restoring conservative cavities on the changes in cuspal deflection. oper dent 2013; 38(2):1-8. 11. pereira jr, de ornelas f, conti pc, do valle al. effect of a crown ferrule on the resistance of endodontically treated teeth restored with prefabricated posts. j prosthet dent 2006; 95: 50-4. 12. salameh z, sorrentino r, papacchini f, ounsi hf, tashkandi e, goracci c, ferrari m. fracture resistance and failure patterns of endodontically treated mandibular molars restored using resin composite with or without translucent glass fiber posts. j endod 2006; 32(8):752-55. 13. sorrentino r, salameh z, zarone f, tay f, ferrari m. effect of post–retained composite restoration of mod prepration on the fracture resistance of endodontically treated teeth. j adhes dent 2007; 9:49-56. 14. campos ea, andrade mf, porto-neto st, campos la, saad jr, deliberador tm, oliveira-júnior ob. cuspal movement related to different bonding techniques using etch-and-rinse and self-etch adhesive systems. eur j dent 2009; 3(3): 213-18. 15. kikuti wy, chaves fo, di hipólito v, rodrigues fp, d‘alpino php. fracture resistance of teeth restored with different resin based restorative systems. braz oral res 2012; 26(3): 275-81. 16. el-helali r, dowling ah, mcginley el, duncan hf, fleming gj. influence of resin-based composite restoration technique and endodontic access on cuspal deflection and cervical microleakage scores. j dent 2013; 41(3): 216-22. 17. kim me, park sh. comparison of premolar cuspal deflection in bulk or in incremental composite restoration methods. oper dent 2011; 36(3): 326-34. 18. hamouda im, shehata sh. fracture resistance of posterior teeth restored with modern restorative materials. j biomed res 2011; 25(6): 418-24. 19. soares cj, fonesca rb, gomid ha, correr-sobrinho l. cavity preparation machine for standardization of in vitro preparations. braz oral res 2008; 22(3): 28187. 20. santos mj, bezzera rb. fracture resistance of maxillary premolars restored with direct and indirect adhesive techniques. j can dent assoc 2005; 71(8): 585a-585c. 21. franca fg, worschech cc, paulillo am, martins lr, lovadino jr. fracture resistance of premolar teeth restored with different filling techniques. j contemp dent pract 2005; 3(6): 85-92. 22. muñoz-viveros c, campillo-funollet m. microleakage in class ii preparations restored with the sonicfill™ system. sonicfill™ portfolio of scientific research, kerr corporation 2012. 23. sakaguchi rl, powers jm. craig‘s restorative dental materials, 13th ed. st. louis: mosby inc.; 2012. pp. 84, 170, 329. 24. thompson y. sonicfill™ depth of cure. sonic fill™ portfolio of scientific research, kerr corporation 2011. 25. ibarra e, lien w, vandewalle k, casey j, dixon s. physical properties of a new sonically activated composite restorative material. inter assoc dent res 2013; (3). 26. tiba a, zeller gg, estrich c, hong a. a laboratory evaluation of bulk fills versus traditional multiincrement-fill resin-based composites. am dent assoc profess 2013; 3(8): 14-25. 27. van ende a, de munck j, van landuyt kl, poitevin a, peumans m, vanmeerbeek b. bulk-filling of high c-factor posterior cavities: effect on adhesion to cavity-bottom dentin. dent mater 2013; 29: 269–77. 28. fox l, harsono m, towers j, perry rd, kugel g. shear bond strength of selective-etch adhesives on cut/uncut enamel. abstract in aadr annual meeting 2012. 29. el gezawi, kaisarly d, al-harbi f, bader d. mtbsanalysis of class-ii bulk versus incremental fill resin composite restorations. inter assoc dent res 2013. 30. manhart j, chen hy, hickel r. clinical evaluation of the posterior composite quixfil in class i and ii cavities: 4-year follow-up of a randomized controlled trial. j adhes dent 2010; 12(3): 237-43. 31. suhail r, al-khafaji a. the effect of low shrinkage dental composite on the fracture strength of weakened premolar teeth. j bagh coll dent 2011; 23(3): 30-6. type of the paper (article journal of baghdad college of dentistry, vol. 34, no. 2 (2022), issn (p):, issn (e): 2311-5270 25 research article surface characterization of pekk modified by strontium –hydroxyapatite coating as implant material via the magnetron sputtering deposition technique ghasak h jani1 * , abdalbseet a fatalla2 1ph d student, college of dentistry, university of baghdad, iraq. 2 professor, department of prosthodontic, college of dentistry, university of baghdad, iraq. *corresponding author's e-mail: : dr.ghasak@avic.uobaghdad.edu.iq abstract background: the best material for dental implants is polyetherketoneketone (pekk). however, this substance is neither osteoinductive nor osteoconductive, preventing direct bone apposition. modifying the pekk with bioactive elements like strontium hydroxyapatite is one method to overcome this (sr-ha). due to the technique's capacity to provide better control over the coating's properties, rf magnetron sputtering has been found to be a particularly useful technique for deposition. materials and methods : with specific sputtering conditions, the rf magnetron technique was employed to provide a homogeneous and thin coating on polyetherketoneketone substrates.. the coatings were characterized by contact angle, adhesion test, x-ray diffraction (xrd), atomic force microscope and elemental analysis with energy dispersive x-ray (edx) results : indicated that strontium hydroxyapatite had successfully deposited onto the surface with significant improvement in the wettability value to provide a suitable environment for cell attachment, spreading, proliferation, and differentiation conclusion: coating pekk with rf magnetron sputtering can provide homogeneous surfaces laying the groundwork for improving pekk's potential bioactivity, such as surface wettability. wetting qualities are critical in implantable materials and are used to predict future osseointegration success. keywords: dental implants, strontium –hydroxyapatite , wettability, polyetherketoneketone, rf magnetron sputtering introduction general dentists and a variety of specialists are currently offering implants as a solution for partial and total edentulism. due to the higher success rate, dental care is turning more and more toward using implant based oral prosthetics. demand for dental implants has been fueling a rapid market expansion and development of new surgical and prosthodontic techniques implant dentistry continues to evolve and expand (1). because dental implants come in a variety of materials, dimensions, geometries, surface qualities, and interface geometry, today's dentist must choose from over 2,000 distinct dental implants and abutments for a given treatment setting (2). mechanizing, electropolishing, plasma spraying, coating, acid etching, surface oxidation, ionization, and phosphate deposit procedures are all used to modify the surface of dental implants. surface modification of dental implants is thought to be the best way to achieve rapid secondary stability, improve boneto-implant contact, and shorten the time it takes to restore missing teeth (3). received date: 12-1-2022 accepted date: 4-2-2022 published date: 15-6-2022 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/jbcd. v34i2.3143 mailto:dr.ghasak@avic.uobaghdad.edu.iq https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v34i2.3143 https://doi.org/10.26477/jbcd.v34i2.3143 j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 26 polyaryletherketones (paeks) are a type of high-performance semi-crystalline electronics thermoplastics with a rare combination of thermal resilience, chemical tolerance and outstanding mechanical properties across a wide range of temperatures. this polymer class also possesses higher heat resistance and excellent electrical efficiency(4-6). in medicine it has been an excellent substitute for titanium in orthopedic applications, and it has been used in dentistry as provisional implant abutment, removable dentures and implanted prostheses and applications continues to grow(7). bioactive bone cement, containing strontium hydroxyapatite (sr-ha), has been designed to have applicable desirable properties (8). previous tests found that sr-ha bone cement did not have cytotoxicity, and was able to support the collapsed spine sr-ha thin films deposited by pulsed laser deposition on titanium substrates, indicating that the existence of sr may not only improve the beneficial impact of ha coatings on osteointegration and bone regeneration, but also avoid undesirable bone resorption (9){jani, 2015 #621}. among the numerous processes, reactive pulsed dc magnetron sputtering surface coating of osseoconductive films has been shown to be successful in increasing the this method is widely used because it produces higher-quality films, has a higher deposition rate, and has excellent long-term process stability. furthermore, this method can deposit a wide range of compounds, especially thin films on polymers (10). the quality of the coated film is largely determined by the plasma settings during the sputtering process (11). the relationship between the features of the deposited film and the chemical compositions of plasma utilized in the sputtering technique should have been used as a criterion for choosing the best plasma conditions for the magnetron sputtering process (12). in this study, the optimum sputtering conditions for the deposition of sr-ha film on pekk using a magnetron sputtering system were accomplished, and the coating layer compositions and roughness were evaluated in relation to sputtering deposition time materials and methods the pilot study was done for selection the most suitable and appropriates coating technique parameter of the sr-ha to the pekk specimens with magnetron sputtering technique. preparation of target in order to perform the rf plasma sputtering of sr-ha powder, a circular target of 50mm in diameter and 3 mm in thickness was prepared .the target was made by mixing (30 g) of sr-ha powder, then loaded and pressed in cylindrical stainless steel mold with dimension of 50 mm in diameter and 3mm in height , the pressing was done under 8 tons pressure for 2 min. using electrical press, to obtain uniform target and to avoid target fracture. the samples were allowed to dry gradually at room temperature for 24 hours to avoid cracks. j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 27 rf magnetron sputtering radio frequency magnetron sputtering was performed in the system chamber which was made from stainless steel .the target was attached to the anode (positive charge) of system and the substrates were attached to cathode (negative charge) rotating disc. the pekk substrates and sr-ha target were introduced inside the sputtering chamber then the chamber window was closed tightly. the distance between substrates and target was fixed to 10 cm the break-in was performed at a rate of 5 watts (w) per minute up to 150 w operating power, with the source shutters closed, prior to deposition from the ha target. the base pressure was less than 5*10-2 pa with an argon gas flow rate of 15 to 20 sccm and a throw distance of 100 mm. during sputter deposition, the chamber pressure was maintained at 310-2 pa.. the substrates were heated gradually to reach balance temperature of 80° c. the deposition was done at 2 rpm in order to increase the uniformity of distribution. three sputtering intervals (runs) were performed. the working conditions were summarized in table,13 table 1: the working conditions of deposition sr-ha on the pekk substrates then coating prepared samples tested adhesion and wettability thus, the final results determined best condition for coated pekk by srha contact angle (wettability) since the wetting properties is very important in implantable material and considered as indicator for future good osseointegration, so surface wettability test (water contact angle test) was used to measure the amount of the pekk coated layer wettability for the four tested. the disk with low contact angle measurement (high wetting surface) was chosen for pekk coated with sr-ha specimens and the screws (experimental group). adhesion test the pull-off test is a more quantitative adhesion test in which an adhesive is used to adhere a loading device, typically known as a dolly or stub, to a coating. a load is gradually given until the dolly is pulled sample name deposition time (min) pressure (pa) power (w) distance between target & substrate (cm) substrate temperature (°c) group 1 30 3 × 10-2 150 10 80 group 2 60 3 × 10-2 150 10 80 group 3 90 3 × 10-2 150 10 80 group 4 120 3 × 10-2 150 10 80 j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 28 off using a portable pull-off adhesion tester, such as the positest atm. the tensile strength is measured in pounds per square inch (psi) or mega pascals, based on the force required to pull the dolly off or the force the dolly withstood (mpa) a standard method for the application and performance of the pull-off adhesion test is done according to astm d4541. three sample for each groups tested adhesive strength between coating and substrate. x-ray diffraction analysis phase analysis and structural evaluation was performed for control and experimental groups. phase analysis was studied using 3121 powders x-ray diffractometer using cu kα target radiation. the 2ө angles were swept from 2060° in step of one degree and voltage 40.0kv. the peak indexing was carried out based on the jcpds (joint committee on powder diffraction standards). atomic force microscopical analysis for surface topography: atomic force microscopy can provide 2d and 3d images of the deposited coat that exhibit average roughness (ra). this scanning mode was applied to evaluate surface topography of coating. the examined area was 30× 30 μm and 35× 35 μm for the 2 d and 3d micrographs respectively. in non-contact afm, a sharp probe is positioned close to the surface under study (order of angstroms), the probe is then raster scanned across the surface, and the image is built from the force interactions that occur during the scan. a resonator, commonly a silicon cantilever or a quartz crystal resonator, is attached to the probe. device specifications are dem (controller: dual scope c-21scanner: d3 95-50e. tip information are (tip curvature˂10 nm). force constant is 42 n/m. those images had been analyzed using software program to gain the common roughness (ra), peak-to-valley roughness (rz) (14). elemental analysis with energy dispersive x-ray (edx) it is an x-ray technique which is also referred to as (edx) (energy dispersive x-ray analysis) or (eds) (energy dispersive spectroscopic) used to identify the materials elemental composition, mapping of the elemental of the analyzed sample and image analysis. the main principle of spectroscopy is that each element has a unique atomic structure, allowing for a unique set of peaks on its electromagnetic emission spectrum. for elemental analysis or chemical characterization of a sample, it relies on the interaction of some source of x-ray excitation and a specimen. the consequence of exposing a sample to a high-intensity x-ray is the distinctive x-ray of the elements included in the sample, which was identified by the detector. the detector's signal was decoded and evaluated (15, 16). earlier than detection, samples were sputtered with a skinny layer of platinum (white gold) using a sputtering device to enhance surface conductivity. (17). https://www.astm.org/standards/d4541.htm j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 29 results wettability (contact angle) the result of measuring of the water contact angle for the samples was showed that the contact angle for the control pekk was (81.14) , 30 min. (2.49), 60 min. (2.19) , 90 min. (1.02), and decrease to 0.28 in the 120 min. group, each of these results was repeated three times for each sample and the number above was the average for the readings group. water contact angle images were taken for all study groups (descriptive statistics) were summarized in table (2). statistically f-test of one way anova test shown a highly significance difference in the water contact angle among the five groups, p≤ .01 at three degrees of freedoms as shown in table (3). table 2: descriptive statistic of water contact angle test test groups mean sd se maximum minimum water contact angle test control 81.1433 1.72639 .99673 82.16 79.15 30 min. 2.4910 .79450 .45870 3.39 1.90 60 min. 2.1973 .53113 .30665 2.65 1.61 90 min. 1.0260 .25436 .14686 1.30 .80 120 min. .2863 .40127 .23168 .75 .01 table 3: anova test of water contact angle test the results of the bond strength testing for each coating type. the maximum adhesion strength of sr ha layer deposited on a pekk was 2.59 mpa. (standard range 0.4 -3.3 mpa ) was found 120 min. deposition time for sr ha coatings group. tests within groups between groups sum of squares df mean square sum of squares df mean square f sig. water contact angle test. 8.239 10 .824 15232.780 4 3808.195 4622.171 0.000 [hs] j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 30 table 4 shows the stud pull bond strength of sr ha coatings on peek substrates from this study compared. (descriptive statistic of adhesion test) test groups mean sd se maximum minimum adhesion test 30 min. .620 .1389 .0802 .78 .53 60 min. .880 .2787 .1609 1.20 .69 90 min. 1.290 .5602 .3234 1.86 .74 120 min. 2.590 .7617 .4398 3.18 1.73 table 5: anova test of adhesion test tests within groups between groups sum of squares df mean square sum of squares df mean square f sig. adhesion test. 1.982 8 .248 6.885 3 2.295 9.261 .006 topographical analysis (afm ) surface roughness analysis interpreted by atomic force microscope for both pekk and pekk coating with sr ha specimen surface is shown in figure (1) to identify number of morphological changes on the surface which is roughness value (ra) measured by this technique is about 35.1 nm. and increase to 43.2 nm when coating with sr ha figure 1 : afm micrographs, 3 d and 2d graphs for the average roughness of specimen. a. afm micrographs for pekk, b. afm micrographs for pekk coating with sr ha specime j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 31 xray diffraction the phase analysis was carried out on 3121 powders using a cu k radiation x-ray diffractometer. the 2θ angles were swept in one degree increments from 20 to 60 degrees. the peak indexing was done using the international centre for diffraction data's jcpds (joint committee on powder diffraction standards), icdd file #25-0891 ,#33-1322 , # 9-432 for sr-ha and show the typical xrd patterns of the sr-ha coating on pekk implants. the pekk showing diffraction peaks at 18.7o, 20.8 o, 22.9o and 28.9o, and these corresponded to the diffraction planes of (110), (111), (200) and (211) as based on the previous literature 18 the strongest line of this phase are (602),(332),(105),(333),(615) and (722) at 2ѳ 22.6495 , 25.4855 , 34.1999 , 39.4931 , 40.3676 and 41.2593 respectively. the presence of pekk peaks in the xrd pattern after coating process is due to the penetration of x rays beyond the coated layer figure (2) : xrd pattern of pekk and pekk coating with sr-ha specimen an edx spectrum manifestation the atom peaks correlate with the greatest x-rays received energy levels of pekk and pekk coating with sr ha; the greater peak in a spectrum, the more element concentrated, so the greatest level can be as seen in fig ( 3). figure (3) : edx spectrum of pekk and pekk coating with sr ha specimen discussion radiofrequency (rf) magnetron sputtering as an alternate method for covering implants with ceramic coatings. we recently reported on rf sputtering as a viable method for covering a substrate with a biocompatible ceramic layer. c k o k kev 0 100 200 300 400 500 600 700 800 900 1000 5 10 0 5 10 15 20 25 30 35 40 45 50 55 60 0 200 400 600 800 1000 1200 1400 1600 in te n si ty ( co u n ts ) 2theat (degree) pekk/sr-ha pekk j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 32 the advantages of rf sputter-coating over conventional techniques, based on these preliminary findings, are superior adhesion, thickness homogeneity, and the capacity to coat implants with complex surface geometries. since the wetting properties is very important in implantable material and considered as indicator for future good osseointegration, so surface wettability test (water contact angle test) was used to measure the amount of the pekk coated with sr-ha layer wettability for the ten tested for different sputtering time (30, 60, 90 and 120 minutes) the disk with low contact angle measurement (high wetting surface) was chosen for sr-ha coating pekk as the final experimental specimens. regarding the result of measuring of the water contact angle for the samples is showed that the contact angle for the control pekk was (81.14) , 30 min. (2.49), 60 min. (2.19) , 90 min. (1.02), and decrease to 0.28 in the 120 min., the decrease in the contact angle value could be attributed or explained due to pekk is hydrophobic and bio-inert, which has limited its broad application (19, 20), its hydrophilic due to its hydroxyl groups and hydrophobic aromatic ring, while ha is hydrophilic due to its hydroxyl groups (21). a ha coating has been used in several research to transform hydrophobic substrates to hydrophilic surface materials (22). several studies have employed a ha coating to convert hydrophobic substrate to hydrophilic surface material furthermore, ha has the ability to recruit osteoblasts as well as enhance cell proliferation and osteogenic differentiation in osteoblast cells (23, 24). in this study, ha was used to modify the surface of pekk, resulting in a hydrophilic and bioactive surface that was ideal for cell adhesion, spreading, proliferation, and differentiation (25). coatings must adhere to the substrates they are applied to in order to perform successfully. to determine how well a coating is bound to the substrate, a variety of well-known procedures can be used. a pull-off adhesion tester is commonly used to perform common measuring techniques. the most significant aspect that defines the quality of the applied coating and its clinical application is the adhesive strength between hap coating and substrate (26). surface chemistry, microstructure, surface roughness of the substrate, and processing parameters of the applied technique all influence the bonding strength of hydroxyapatite and substrate. in general, mechanical interlocking and chemical bonding can cause adhesion between coating and substrate, which is consistent with the findings of this study, which show that adhesion increases with deposition time. also the biocomposite deposited film by rf magnetron sputtering under specific working parameters showed a higher roughness surface which consequently enhance bone growth and biological fixation , this finding is in agreement with (pietro et al.,2016)(27) and (prosolovab et al., 2017)(28) who proved that films precipitated by plasma sputtering are characterized by increased roughness of substrates, which can be seen in afm result as surface roughness increase with coating layer produce by rf magnetron sputtering as ra (roughness average) for coating sample is (43.2nm) and for control group (35.1nm). at specified working pressure (3x 10-2) , sputtered atoms or clusters reached the substrate with reduced kinetic energies , which caused the surface roughness to be increased (29). this can be explain increase wettability of pekk coated with sr-ha than uncoated, rough surface is a crucial property must be controlled in processing of implant due to it has superior adsorption of biomolecules from surrounding fluids, in addition affecting in stress distribution at the implant bone line contact, the surface roughness in nano level may be increase cell growth and osteoblastic differentiation, also inhibit colonization of bacteria lead to healing developing with short time before loading (30), as explained by (deng et al., 2015),31 this is agree with rong et al., 2009; eom et al., 2012 (32, 33) who seen that the surface roughness was significantly increase when coated by material with nano or micro particle size. j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 33 the edx analysis of the of pekk coated group shown that, calcium, phosphate, strontium , oxygen and carbon were the chief elements in their surface that indicated the successful coating sr-ha on pekk substrate. in group p, the oxygen and carbon elements referred to pekk material, while the calcium, strontium element referred to sr-ha. this findings are confirmed the formation of sr ha coating layer showed by xrd. the presence of strontium and hydroxyapatite was demonstrated by the x-ray diffraction pattern of a coated layer of strontium-hydroxyapatite. xrd revealed that narrow peaks indicated a layer with a high level of crystallinity, whereas broad peaks indicated a layer with a lower level of crystallinity (34). the amount of strontium-hydroxyapatite element in eds can also be noticed. pekk peaks appear in the xrd pattern following the coating procedure because x rays penetrate beyond the coated layer. conclusion coating pekk with rf magnetron sputtering can provide homogeneous surfaces laying the groundwork for improving pekk's potential bioactivity, such as surface wettability. wetting qualities are critical in implantable materials and are used to predict future osseointegration success. conflict of interest: none. references 1. gowd ms, shankar t, ranjan r and singh a. prosthetic consideration in implant-supported prosthesis: a review of literature. j int soc prev community dent. 2017;7:s1. 2. jokstad a, braegger u, brunski jb, carr ab, naert i and wennerberg a. quality of dental implants. int. dent. j. 2003;53:409443. 3. jung u-w, hwang j-w, choi d-y, hu k-s, kwon m-k, choi s-h and kim h-j. 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jiang j, wu z and chu pk. mechanical and biological characteristics of diamond-like carbon coated poly aryl-ether-ether-ketone. biomat. 2010;31:8181-8187. 20. briem d, strametz s, schröoder k, meenen n, lehmann w, linhart w, ohl a and rueger j. response of primary fibroblasts and osteoblasts to plasma treated polyetheretherketone (peek) surfaces. j. mater. sci.: mater. med. 2005;16:671-677. 21. noiset o, schneider y-j and marchand-brynaert j. fibronectin adsorption or/and covalent grafting on chemically modified peek film surfaces. j. biomat. sci., polymer edition. 1999;10:657-677. 22. bodhak s, bose s and bandyopadhyay a. role of surface charge and wettability on early stage mineralization and bone cell – materials interactions of polarized hydroxyapatite. acta biomat. 2009;5:2178-2188. 23. ruan j-m and helen gm. biocompatibility evaluation in vitro. part i: morphology expression and proliferation of human and rat osteoblasts on the biomaterials. j. cent. south univ. technol. 2001;8:1-8. 24. yuan h, kurashina k, de bruijn jd, li y, de groot k and zhang x. a preliminary study on osteoinduction of two kinds of calcium phosphate ceramics. biomat. 1999;20:1799-1806. 25. thamaraiselvi t and rajeswari s. biological evaluation of bioceramic materials-a review. carbon. 2004;24:172. j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 35 26. mohseni e, zalnezhad e and bushroa ar. comparative investigation on the adhesion of hydroxyapatite coating on ti–6al–4v implant: a review paper. int j adhes adhes. 2014;48:238-257. 27. mandracci p, mussano f, rivolo p and carossa s. surface treatments and functional coatings for biocompatibility improvement and bacterial adhesion reduction in dental implantology. coat.. 2016;6:7. 28. prosolov k, popova k, belyavskaya o, rau j, gross k, ubelis a and sharkeev yp. rf magnetron-sputtered coatings deposited from biphasic calcium phosphate targets for biomedical implant applications. bioact. mater. 2017;2:170-176. 29. majeed a, he j, jiao l, zhong x and sheng z. surface properties and biocompatibility of nanostructured tio 2 film deposited by rf magnetron sputtering. nanoscale res. lett 2015;10:1-9. 30. kligman s, ren z, chung c-h, perillo ma, chang y-c, koo h, zheng z and li c. the impact of dental implant surface modifications on osseointegration and biofilm formation. j j. clin. med. 2021;10:1641. 31. deng y, liu x, xu a, wang l, luo z, zheng y, deng f, wei j, tang z and wei s. effect of surface roughness on osteogenesis in vitro and osseointegration in vivo of carbon fiber-reinforced polyetheretherketone–nanohydroxyapatite composite. int. j. nanomedicine 2015;10:1425. 32. rong m, zhou l, gou z, zhu a and zhou d. the early osseointegration of the laser-treated and acid-etched dental implants surface: an experimental study in rabbits. j mater sci mater med 2009;20:1721-1728. 33. eom t-g, jeon g-r, jeong c-m, kim y-k, kim s-g, cho i-h, cho y-s and oh j-s. experimental study of bone response to hydroxyapatite coating implants: bone-implant contact and removal torque test. oral surg. oral med. oral pathol. oral radiol. 2012;114:411-418. 34. kweh s, khor k and cheang p. the production and characterization of hydroxyapatite (ha) powders. j. mater. process. technol. 1999;89:373-377. 35. abdulmunem mm and mohammed ja. immediate implant placement in fresh extraction socket. j. baghdad coll. dent . 2016;28:103-110 36. jani gh, al-ameer ss and jawad sn. histological and histomorphometric analysis of strontium chloride coated commercially pure titanium implant compared with hydroxyapatite coating. j. baghdad coll. dent 2015;27:26-31. j. bagh. coll. dent. vol. 34, no. 2. 2022 jani and fatalla 36 المغنطروني االخرق ترسيب تقنية عبر غرسية كمادة هيدروكسيباتيت -السترونشيوم طالء بواسطة المعدل كيتون كيتون إيثير لبولي السطحي التوصيف عبد الباسط احمد, 1غسق هشام جاني الباحثون: المستخلص . كيتون كيتون إيثير البولي تعديل. المباشر العظام توضيع يمنع مما ، للعظم موصلة وال عظمية حاثية ليست المادة هذه فإن ، ذلك ومع. كيتون كيتون إيثير البولي مادة هي األسنان لزراعة مادة فضل ، الطالء خصائص في أفضل تحكم توفير على التقنية لقدرة نظًرا. هيدروكسيباتيت السترونشيوم هذا على للتغلب الطرق إحدى هي هيدروكسيباتيت السترونتيوم مثل بيولوجيًا النشطة العناصر مع .للترسيب خاص بشكل مفيدًا أسلوبًا ليكون المغنطرون رش على العثور تم واختبار التالمس بزاوية الطالءات تميزت.. كيتون كيتون إثير بولي ركائز على ومتجانسة متجانس رقيق طالء لتوفير المغنطرون تقنية استخدام تم ، محددة رشاش ظروف في: والطرق المواد للطاقة المشتتة السينية األشعة مع العنصري والتحليل الذرية القوة ومجهر السينية األشعة وانحراف االلتصاق . وتمايزها وتكاثرها وانتشارها الخاليا لربط مناسبة بيئة لتوفير البلل قابلية قيمة في كبير تحسن مع السطح على بنجاح ترسب قد هيدروكسيباتيت السترونتيوم أن إلى أشارت: النتائج . للبلل السطح قابلية مثل كيتون ، كيتون إيثير لـ البولي المحتمل الحيوي النشاط لتحسين األساس تضع متجانسة أسطًحا يوفر أن يمكن المغنطرون رش مع. كيتون كيتون إيثير بولي طالء: الخالصة . المستقبل في العظمي الزراعة بنجاح للتنبؤ وتُستخدم للزرع القابلة المواد في حاسمة الترطيب صفات تعتبر j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 13 the effect of different light cure systems on microhardness of bulk fill composite materials linz a. shalan, b.d.s., m.sc. (1) samer awn thiab, b.d.s., m.sc. (2) abstract background: the aim of this study was to evaluate the effect of three types of light curing devices qth, led and flashmax on the surface microhardness of three types of bulkfill composite resins; filtek bulkfill posterior composite ( 3m), tetric evo ceram ( ivoclar vivadent) and sonicfill composite ( kerr) materials and methods: total number of 90 samples was prepared, 30 samples for each type of bulkfill composite, were divided into three main groups, group a: filtek posterior bulkfil (3m), group b: tetric evo ceram (ivoclar vivadent) and group c: contain sonicfill composite (kerr). which then divided into three subgroups (n= 10) (1) samples cured by qth system (2) samples cured by led system and (3) samples cured by flashmax system then all samples were subjected for microhardness test (by vickers hardness tester). the data were recorded and statistically analyzed, by the anova and the tukey test. results: the data was subjected to statistical analysis using one way anova and tukey test, the result revealed that there was a high significant difference among the tested units with led had high vhn values followed by qth while flashmax had lowest vhn values, also there was high significant difference among the tested materials in which sonicfill composite had higher vhn value followed by tetric evoceram while filtek bulkfill posterior composite had the lowest vhn. conclusions: microhardness of the composite resin materials depend upon energy of the curing device, time of exposure, composition of the composite material. key word: microhardness, bulkfill composite, flashmax, sonicfill. . (j bagh coll dentistry 2017; 29(2):13-20) introduction bulk-fill composites are popular restorative materials that have been in the market for several years, unlike traditional composites, which typically are placed in maximum increments of 2 mm, bulk-fill composites are designed to be placed in 4 mm, or sometimes greater increments. restoring a tooth in one step certainly appears to save time, there are some concerns. for example, manufacturers claim that bulk-fill materials have greater depth of cure and lower polymerizationinduced shrinkage stress. one proposed rationale for limiting composite increments to 2 mm is to allow the curing light to penetrate to the resin farthest away from the light source (1). a second reason for using 2-mm increments is to minimize the shrinkage and shrinkage-induced stress associated with composite polymerization. contraction stresses that exceed the adhesive strength of the composite may result in gaps between composite and cavity walls. it is widely believed that these marginal gaps may lead to microleakage, sensitivity and secondary caries, although there is little clinical evidence to support that secondary caries are caused by this gap formation (2). (1) assist. professor,. department of conservative dentistry, college of dentistry, university of baghdad. (2) lecturer. depart ment of conservative dentistry, college of dentistry, university of baghdad. polymerization of the core of the restoration is directly related to the material's chemical composition, the organic (type of matrix) or inorganic portion (type and morphology of filler contents). moreover, it is influenced by the thickness of the increment inserted into the cavity, intensity and irradiation time, light spectrum, and distance of the tip of the light curing unit to the material to be activated (3). factors affecting resin-based composites’ depth of cure have been identified mainly as curing source intensity and light exposure duration, filler size and content, interactions at the filler-matrix interface, shade and translucency (2). however, the polymerization reaction cannot be considered finished after exposure to light due to the presence of what is called "dark polymerization" (4). it can be explained by the presence of a temporary excess of free volume of monomers with enough mobility that allows molecules to still interact at lower rates. it has been reported that the values of resin conversion for most of the commercial dental composites vary from 40-75% (4). sonicfilltm composite (kerr corp., usa) is a nanohybrid, low-shrink, resin-based, radiopaque, sonic-activated, bulkfill composite material designed for direct placement for all cavity classes in posterior teeth without additional capping layer. it allows a depth of cure of 5mm, incorporates a highly-filled proprietary resin with special rheological modifiers that react to sonic energy. as sonic energy is applied through the hand piece, j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 14 the modifier causes the viscosity to drop (up to 87%), increasing the flow ability of the composite and enabling quick replacement and precise adaptation to the cavity walls. when the sonic energy is stopped, the composite returns to a more viscous, non-slumping state for curving and contouring (5). the light-curing unit plays a more influential role in the basic properties of resin-based composites. quartz-tungsten-halogen (qth) units have been widely used for polymerizing resinbased dental materials for decades. qth units exhibit several shortcomings, so, as an alternative, light-emitting diode (led) light curing units were introduced for polymerizing resin-based composites. however, conflicting results have often been observed in the literature as related to the effects of both light curing units (5). recently, resin-based composite curing lights have been developed that have higher intensities and shorter curing cycles which help speed the resin-based curing (4). one of these new high intensity light curing units is the flash max p3(cms co., denmark) whose light intensity ranges from 4000-5000 mw/cm2 and supposed to give 6 mm curing depth in only three seconds as claimed by the manufacturer (6). the relative importance of a microhardness test lies in the fact that it throws a light on the mechanical properties of a material. the higher the degree of conversion, the better the mechanical properties, hardness, biocompatibility, water sorption, color stability and wear resistance of the resin composite (7). microhardness is often traditionally used as indirect measurement of effectiveness of composite cure or the degree of conversion, so the aim of this study was to evaluate and compare the influence of different light curing system (conventional qth, soft start led and flashmax) on micro hardness of three types of bulkfill composite (filtek bulkfill posterior composite, tetric evo ceram bulkfill, sonic fill composite). materials and methods three types of bulkfill composite were used in this study 1. filtek bulkfill posterior composite (3m). 2. tetric evo ceram (ivoclar vivadent), 3. sonic fill composite (kerr). their composition and shade presented in table (1) three light curing device were used 1. qth, 2. led, 3. flashmax their intensity and exposure times presented in table (2), sonicfill composite and filtek bulkfill posterior composite comes in universal shade, while tertic evo ceram comes in three shades iva, ivb and ivw. in this study we use the lighter shade iva. grouping group a: contain 30 samples made from filtek bulkfill posterior composite (3m) subdivided into 3 subgroup group a1: contain 10 samples of filtek bulkfill posterior composite cured by qth. group a2: contain 10 samples of filtek bulkfill posterior composite cured by led. group a3: contain 10 samples of filtek bulkfill posterior composite cured by flashmax. group b: contain 30 samples made from tetric evo ceram composite (ivoclar vivadent) subdivided into 3 subgroup group b1: contain 10 samples of tetric evo ceram composite cured by qth. group b2: contain 10 samples of tetric evo ceram composite cured by led. group b3: contain 10 samples of tetric evo ceram composite cured by flashmax. group c: contain 30 samples made from sonicfill composite (kerr) subdivided into 3 subgroup group c1: contain 10 samples of sonicfill composite cured by qth. group c2: contain 10 samples of sonicfill composite cured by led. group c3: contain 10 samples of sonicfill composite cured by flashmax. sample preparation: two-piece aluminum mold with a diameter of 6mm and a height of 4mm (7) was used for the preparation of composite specimens for the evaluation of the depth of cure. a celluloid strip was placed on a flat glass slide on top of a white background. the aluminum mold was then placed on it and slightly over filled in one increment with one of the composite materials and a second celluloid strip was then placed on top of the mold and overlaid with another glass slide with the application of 100gm load to extrude excess material. the top slide was then removed and the composite resin light-cured with either of the following curing units: (1) quartz tungstenhalogen (qth) light curing unit (ivoclar), (2) led light curing unit (usa)(3) flashmax p3high intensity led curing unit (cms co., denmark). the tip of the light curing unit was placed in direct contact with the overlaid celluloid strip. the light guide of qth light curing unit has a diameter of 4mm, while the flashmaxp3 light curing unit is supplied with two light guides: a 4mm tip and an 8mm tip light guides. the 4mm j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 15 tip was used in this study for the purpose of standardization, after completing the light curing procedure, the over laid celluloid strip was removed and the aluminum mold was opened. then stored for 24hours in a light proof container with distilled water at 37˚c to complete polymerization and inhibit any further polymerization from transient light (7). relative microhardness was measured b y doing the surface microhardness test on both sides of the samples (top and bottom) to give indication about the depth of cure by calculating the ratio of bottom/top hardness. a minimum value of 0.80 have to be reached in order to consider the bottom microhardness of the samples was determined using vickers microhardness tester (micromet 6040 wilson microhardness; buehler, u.s.a.). table 1: composition of the tested composite materials product the resin matrix: the filler: filler size filler loading manufacture shade filtek bulk fill, posterior restorative audma, udma, and 1, 12dodecane-dma. silica filler, a zirconia fill and ytterbium trifluoride filler 4-20nm 76.5%wt 3m espe, st. paul, usa a2 tetric evoceram bulk fill bis-gma udma bis-ema ytterbium fluoride, barium aluminium silicate glass 550 nm (mean) 80% wt ivoclar vivadent a sonic fill bis-ema tegdma silicon dioxide glass, oxide, chemicals zirconium compound ytterbium triflouride 0.4µm30nm 83% wt kerr a2 table 2: curing systems used in this study device intensity exposure time wave length manufacturer qth 400 40 s 400-500 ivoclar, austeria led 460 40 s 440-480 usa flashmax 4000 3 s 4000-5000 denmark results statistical analysis among groups for the effect of light curing system on tested materials: descriptive analysis for both top and bottom surfaces: means, standard deviation for microhardness values vhn for the three tested curing systems on both top and bottom surfaces the result showed that led had the highest means followed by qth and lowest mean value for flashmax as shown in table (3). interfacial analysis anova test was made among tested groups for both top and bottom surfaces which revealed a high significant differences (p<0.001) in microhardness values hv among groups as shown in table (3). table 3: descriptive & anova for the effect of tested light curing systems on top and bottom surfaces of the tested materials m ean std. deviation f p-value sig m ean st d. deviation f p -value s ig a1 53.44 7.14 39.11 4.94 b1 56.94 4.41 49.08 3.56 c1 67.04 4.20 32.91 5.71 a2 58.93 5.01 46.79 5.34 b2 59.49 4.04 54.81 4.62 c2 70.36 3.04 43.34 3.53 a3 49.68 3.04 57.06 1.40 b3 52.99 2.71 65.36 4.97 c3 64.50 4.06 51.62 5.40 descriptive & anova for bottom s urface groups subgroups 25.736 .000 .000 .000 hs hs hs hs hs hs 16.993 0.001 24.557 0.001 54.921 0.001 28.667 16.664 flashmax qth led des criptive & anova for top s urface j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 16 the data revealed from anova test analyzed by tueky's test for all tested material for both top and bottom surfaces which showed that for (top surface) the materials which cured by qth there was a non-significant difference (p<0.05) between group a1 and b1, high-significant differences between group a1 and c1 (p< 0.001), highly significant differences between group b1 and c1 (p< 0.001) in microhardness value vhn. for led there was non-significant difference (p< 0.05) between group a2 and b2, a highsignificant difference (p< 0.001) between a2 and c2, high significant differences between b2 and c2. for flashmax there was non-significant difference between a3 and b3, also highsignificant differences between a3 and c3, high significant differences between b3 and c3 as shown in table (4) and figure (1). for the (bottom surfaces) tukey test revealed that for qth there was a high significant differences between group a1 and b1, a significant differences between group a1 and c1(p> 0.01), a high significant differences between group b1 and c1(p< 0.001). for led there were high significant differences between a2 and b2, significant differences between a2 and c2, high significant differences between groups b2 and c2. for flashmax there was a high significant difference between group a3 and b3, significant differences between a3 and c3, high significant differences between b3 and c3 as shown in table (4). table 4: tukey test for the effect of light curing systems on top and bottom surfaces of the tested materials tukey test for top surface tukey test for bottom surface groups sub-groups mean diff p-value sig mean diff p-value sig qth a1 b1 -3.50 .333 ns -9.97 .000 hs c1 -13.60 .000 hs 6.20 .021 s b1 c1 -10.10 .001 hs 16.17 .000 hs led a2 b2 -0.56 .950 ns -8.02 .001 hs c2 -11.43 .000 hs 3.45 .020 s b2 c2 -10.87 .000 hs 11.47 .000 hs flashmax a3 b3 -3.31 .084 ns -8.30 .001 hs c3 -14.82 .000 hs 5.44 .020 s b3 c3 -11.51 .000 hs 13.74 .000 hs figure 1: a chart show the effect of curing system on vhn for the top surfaces of the tested materials descriptive and interfacial analysis for microhardness according to the type of material: descriptive statistics for both top and bottom surfaces: means, standard deviation for microhardness values vhn for the three tested composite materials for both top and bottom surfaces are listed in table (3), the result showed that sonicfill composite had the highest means followed by 0 10 20 30 40 50 60 70 80 qth led flashmax filtek bulkfill tetric evo ceram sonicfill j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 17 tetric evo ceram and lowest mean value for filtek bulkfill composite as shown in table (5). table 5: descriptive and interfacial statistics for top and bottom surfaces for the tested materials group descriptive & anova for top surface descriptive & anova for bottom surface groups subgroup mean top surface sd f pvalue sig mean bottom surface sd f p-value sig filtek bulk fill posterior a1 53.44 7.13 7.612 0.002 hs 39.01 4.7 26.05 0.000 hs a2 58.93 5.01 48.08 3.73 a3 49.68 3.04 32.91 5.71 tetric evo ceram b1 56.94 4.41 7.46 0.003 hs 46.69 5.05 16.99 0.000 hs b2 59.49 4.04 53.81 3.92 b3 52.99 2.7 43.34 3.53 sonic fill c1 67.04 4.2 8.81 0.001 hs 57.03 2.31 24.14 0.000 hs c2 70.36 3.04 64.56 4.39 c3 64.5 4.05 51.62 5.4 inferential statistics statistical analysis of data by using anova test for all groups of tested composite revealed that there is a high significant differences (p< 0.001) in microhardness values vhn among the groups for each composite material after curing with different light curing systems in both top and bottom surfaces as shown in table (5). the data revealed from anova test analyzed by tueky test for all tested material for both top and bottom surfaces which showed that for (top surface) of filtek bulkfill posterior composite there was anon-significant difference (p< 0.05) between group a1 and a2, non-significant differences between group a1 and a3 (p< 0.05), highly significant differences between group a2 and a3 (p< 0.001) in microhardness value vhn. for tetric-evo ceram there was non-significant difference (p< 0.05) between group b1 and b2, a non-significant difference between b1 and b3, high significant differences between b2 and b3. for sonicfill composite there was nonsignificant difference between c1 and c2, also non-significant differences between c1 and c3, high significant differences between c2 and c3 as shown in table (6) and fig (2). table 6: tukey test for the groups of tested materials for both top and bottom surfaces. tukey test for top surface tukey test for bottom surface groups sub-groups mean diff p-value sig mean diff p-value sig filtek bulkfill a1 a2 -5.49 0.073 ns -10.07 0.000 hs a3 3.76 0.273 ns 5.10 0.01 s a2 a3 9.25 0.002 hs 15.17 0.000 hs tetric evo ceram b1 b2 -2.55 0.305 ns -8.12 0.001 hs b3 3.95 0.069 ns 2.35 0.037 s b2 b3 6.5 0.002 hs 10.47 0.000 hs sonic fill c1 c2 -3.32 0.104 ns -8.53 0.000 hs c3 3.24 0.114 ns 4.41 0.019 s c2 c3 6.56 0.001 hs 12.94 0.000 hs j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 18 figure 2: chart for the microhardness value for the three tested materials top surfaces figure 3: chart for the microhardness value for the three tested materials bottom surfaces tukey test for bottom surface showed that for filtek bulkfill posterior composite there was a high significant differences among group a1 and a2, significant differences among group a1 and a3, high significant differences among a2 and a3. for tetric evo ceram high significant differences between group b1 and b2, significant differences between b1 and b3, high significant differences between group b2 and b3. for sonicfill there was high significant differences between c1 and c2, significant differences between group c1 and c3, high significant differences between group c2 and c3 as shown in table (6) and fig(3) another analyses were made between top to bottom for each material following this equation bottom/top =ratio as shown in table (7). form table (7) all tested material reach the top/bottom ratio of 0.8 except for filtek bulk fill posterior composite cured with qth ( group a1) and cured with flashmax (group a3). table 7: bottom/ top ratio for all groups group subgroup top/bottom ratio top/bottom ratio filtek bulkfill a1 0.711 a2 0.815 a3 0.662 tetric evo ceram b1 0.802 b2 0.904 b3 0.817 sonic fill c1 0.835 c2 0.917 c3 0.8 discussion effect of light cure system on microhardness: if the resin composite does not receive sufficient total energy various problems may occur with the final restoration such as the reduction in the amount of monomer to polymer conversion an increased cytotoxicity of the restorative material, reduction in the hardness of 0 20 40 60 80 qth led flash max filtek bulk fill tetric evo ceram sonic fill j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 19 the restorative material. adequate polymerization of the light cured composite materials depend upon (1) light activation energy (2) wave length (3) curing time. in this study led show highest microhardness vhn value for all tested material followed by qth and the lowest vhn value for flashmax as shown in tables (3), fig (1) for both top and bottom (4 mm depth) for all tested groups. this can be explained by analyses of total amount energy density of the system which is an important parameter and it is the amount of energy of appropriate wavelength emitted during irradiation. this energy is calculated as the product of the output of the curing light unit and the time of irradiation which can be calculated from the equation: energy density= intensity x time (10) as a result qth have energy density 16 j/cm2, led has energy density 18.4 j/cm2 and flashmax have energy density 12 j/ cm2. this results agree with findings (11,12). also the depth of cure of composite resin is mainly dependent on exposure time of the light source to the composite resin (9) therefore, the short curing time for flashmax unit as recommended by manufacturer (table 2) led to low vhn value for the tested materials this can be explained as the duration of the exposure will allow the excited camphorquinon (typical photosensitive agent in light cured dental resin composites) molecules to diffuse and react with a mine and it is important to increase exposure duration and use appropriate light curing device to maximize the hardness of the resin materials(13). this result agree with previous studies (9,13,14) effect of the material on the microhardness: sonicfill composite had the highest microhardness value vhn among the tested composite material in all used curing system as shown tables (5,6) and figure (2,3), from both top and bottom curing value followed by tetric evo ceram composite and the lowest microhardness value vhs for filtek bulk fill posterior composite. this in agreement with previous studies (12,15). which claimed that sonicfill system had the highest score among the tested materials and can be used as an alternative to regular composite for posterior teeth (12) .this is related to several factors (1) the nano-filling technology which led to material have better mechanical properties than other types of composite (12) (2) the optical properties of resins (optical transmission coefficient) which vary with material composition (particle type, contents and size) (16), from table (1) sonicfill composite have higher filler loading (83%) followed by tetric evo ceram (80%) and filtek bulkfill posterior composite (76.5%) this result in agreement with previous study (15,16) , as an increase in filler content results in higher hardness means. as regard the size of the incorporated fillers, the filler particles in the resin based composites scatter light, this scattering effect is increased as the particle size of the fillers in the composite approaches the wavelength of the activating light and will reduce the amount of light that is transmitted through the composite (16). material with the smallest filler particles size (0.19-3.3µm) showed the highest values of overall light transmittance for all filler contents, where as those with larger size (0.04-10) µm showed lower light transmittance for all filler contents (17) from table (1) the sonicfill composite had the smaller size of filler particles and this result in agreement the previous studies (16). so as regards the particle type the zirconium is harder than heavy-metal glass and the crystalline form (zirconium silica) is harder than non-crystalline (glass) and it diffuse light as it penetrate (16). optical properties of sonicfill can explain the higher microhardness of sonicfill composite as compared with tertic evo ceram although both of them are nanohybrid composite this in agreement with previous studies (5). also tetric evo ceram bulk fill composite exhibits a statistical higher microhardness value than filtek bulk fill posterior composite may be attributed to the presence of polymerization booster (ivocerin) which it is highly reactive photoinitiator system allows a faster, deeper curing than other composites and it is allow application larger increments with greater depth of up 4mm in very short time and light sensitivity inhibitor which integrated into photoinitior system and act as a protective shield against ambient light like operating light (12). effect of depth of the material on microhardness the microhardness of resin composites are affected by the resin composite thickness (18), in the present study the same tendency of the microhardness decreasing as the resin thickness increased was observed as shown in table (3). previous studies reported that the resin hardness at the bottom was significantly different from that at the top when the specimens were 4 to 5 mm thickness this result in agreement with previous studies (18,19). this is due to the fact that at top surface sufficient light energy reach photoinitior, thus starting the polymerization reaction as light passes through the body of a composite, it is intensity is greatly decreased due to absorption and dispersion of light by filler particles and resin j bagh college dentistry vol. 29(2), june 2017 the effect of different restorative dentistry 20 matrix. this decrease results in a gradation of cure causing a decrease in hardness level from the top surface to inwards. this fact explain the difference between top surface and bottom surface hardness for all tested materials and tested curing unites this finding in agreement with previous studies (20) . the bottom/top hardness ratio above 80% has often been used as a minimum acceptable threshold which means in this study the material which bottom/top ratio of 80% and above can be placed and cured properly in the 4 mm bulk in clinical situations as shown in table (7). refreness 1. sarrett dc. a laboratory evaluation of bulk-fill versus traditional multiincrement– fill resin-based composites. ada 2013; 8: 13-26. 2. sarrett d. clinical challenges and the relevance of materials testing for posterior composite restorations. dent mater 2005; 21: 9-20. 3. alshali rz, salim na, satterthwaite jd, silikas n. post-irradiation hardness development, chemical softening, and thermal stability of bulk-fill and conventional resin-composites. j dent 2015; 43: 20918. 4. dukic w, delija b, derossi d, dadic i. radiopacity of composite dental materials using a digital ray system. dent mater j 2012; 31(1): 47-53. 5. ilie n, rencz a, hickel r. investigation towards nonohybrid resin-based composites. clin oral invest 2013; 17: 185-93. 6. lombardini m, chiesa m, scribante a. influence of polymerization time and depth of cure of resin composites determined by vickers hardness. dent res j 2012; 9(6): 735-40 7. ajaj ra. relative microhardness and flexural strength of different bulk fill resin composite restorative materials. j am sci 2015; 11(7):155-9. 8. alrahlah a, silikas n, watts dc. post-cure depth of cure of bulk fill dental resin composites. dent mater 2014; 30: 149-54. 9. flury s, hayos s. depth of cure of resin composite: is the iso 4049 method suitable for bulk fill materials? dent mater 2012; 28(5):521-528. 10. czasch p, ilie n. in vitro comparison of mechanical properties and degree of cure bulk fill composites. clinical oral investigations 2013; 17: 227–35. 11. ceballos l, fuentes mv, tafalla h, martínez á, flores j, rodríguez j. curing effectiveness of resin composites at different exposure times using led and halogen units. medicina oral, patologia oral y cirugiabucal. 2009;14: e51-6. 12. yousef mkh, ibrahim a. effect of different light curing units on microhardness of different bulkfill materials. life sci j 2015; 12(5): 24-30. 13. alpoz ar, ertugrual f. effect of light curing method and exposure time on mechanical properities of resin based composite. dent mate eur j dent 2008; 2: 3742. 14. lombardini m, chiesa m. influence of polymerization time and depth of cure of resin composite determined by vickers hardness. 2012; 9(6): 735-9. 15. didem a, gozedey. comparative mechanical properties of bulkfill resin. open j composite materials 2014; 4: 117-21. 16. kim kh, ong jl, okuno o. the effect of filler loading and morphology on the mechanical properties of contemporary composites. j prosthet dent 2002; 87: 642-9. 17. arikawa h, kanie t. effect of filler properties in composite resins on light transmittance characteristics and color. dent. mater j 2007; 26(1): 38-44. 18. moore bk, platt a, borgs g, chu tm. depth of cure of dental resin composites: iso 4049 depth and microhardness of types of materials and shades. oper dent 2008; 33: 408-12 19. kim e, jung h. effect of resin thickness on the microhardness and optical properties of bulkfill rein composites. restor dent endod 2015; 40:128-35. 20. nogueira jcc, borsatto mc, wanessa christine de souza-zaroni wc. microhardness of composite resin at different depths varying the post irradiation time. j. appl oral sci 2007; 15(4):1657-78. j bagh college dentistry vol. 33(2), june 2021 management of trauma 16 management of trauma to the anterior segment of the maxilla: alveolar fracture and primary incisors crown and root fracture muna s. khalaf (1), bayan s. khalaf (2), shorouq m. abass (2) https://doi.org/10.26477/jbcd.v33i2.2934 abstract background: an injury to both the primary and permanent teeth and the supporting structures is one of the most common dental problems seen in children. splinting is usually difficult or impossible to perform in the primary dentition (due to diminutive room size and lack of patient cooperation). healing must, therefore, occur despite mobility at the fracture line, usually resulting in interposition of connective tissue. in some instances, infection will occur in the coronal pulp. the present study reported a case of trauma to the anterior primary teeth and alveolar bone in a four year old child. the trauma has caused fracture to the crowns and roots of the primary anterior teeth. the following case was managed in a procedure that may provide primary teeth subjected to trauma a better chance than extraction with a better prognosis. case presentation: a 4 and a half year old child was subjected to trauma in anterior segment of maxilla. suturing of the torn soft tissue was the first step followed by pulpotomy for the left primary lateral incisor. fixation of the right primary central and lateral incisors was done by acid etch wire fixation. both clinical and radiographic follow up was carried out for 6.4 years. results: healing of the soft tissue was observed after one week and completed after two months. fixation of the teeth continued for ten months. the fracture lines in the roots remained in position. clinically there was no sign of any pulpal inflammation or necrosis. radiographically, no signs of infection to the surrounding tissues could be seen, no resorption in the alveolar bone, external or internal resorption of the root did not happen also. after ten months fixation ended and the wire was removed. at that time there was normal resorption of the roots of the primary incisors in relation with the normal development of the permanent incisors. after 3 years both permanent central incisors erupted in their normal position. after 6.4 years all four permanent incisors erupted into occlusion in their normal position. conclusion: primary teeth with root fractures and severely mobile coronal fragments can be treated by a conservative approach. the severity of the sequels is directly related to the degree of permanent tooth formation (child’s age), type of dental trauma and extent of the impact. key words: trauma, primary incisors, fractured crown and root. (received: 18/2/2021, accepted: 22/3/2021) introduction oral and dental trauma is common in infants, preschool and school aged children (1). the prevalence of traumatic injuries to primary incisors and canines was 24.4% in an iraqi study carried out in 1988 by kh yagot et al, being at its highest percentage in the 4 year old children (2). injuries to children’s teeth can be very distressing for children as well as their parents. the maxillary central incisors are most commonly involved because of their anterior position and protrusion caused by the eruptive process. the peak period for trauma to the primary teeth is 18 to 40 months of age, because this is a time of increased mobility for the relatively uncoordinated toddler. injuries to primary teeth usually result from falls and collisions as the child learns to walk and run (1). root fractures are uncommon in teeth with incomplete root development and those in various stages of eruption because of resilience of the alveolar bone. a traumatic injury in a deciduous tooth or in one with an incompletely formed root with less periodontal support will most likely result in a luxation or avulsion injury rather than a root fracture. etiology of root fractures can be classified into two groups as: group 1 comprising of fractures occurring in none endodontically treated teeth and group 2 as fractures occurring in endodontically treated teeth. group 1 fractures are rare and occur from accidental or occlusal trauma (3). few literature is available about trauma to primary dentition in iraq. most studies are on trauma to the permanent dentition the treatment principles for horizontally fractured teeth mainly involve immobilizing the coronal segment so as to maintain pulp vitality. there are four healing patterns that can affect the prognosis and tissue response to dental trauma. healing with the formation of calcified tissue, healing with the formation of interproximal connective tissue, healing with the formation of interproximal bone and connective tissue, and interproximal inflammatory tissue without healing (4). treatment alternatives for fractured roots in primary roots depend on the stability of the coronal fragment of the injured tooth. if the coronal part of the tooth is stable and does not (1) assistant professor, department of pedodontic and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of prosthetic dentistry, college of dentistry, university of baghdad. corresponding email, munasaleemkhalaf@gmail.com https://doi.org/10.26477/jbcd.v33i2.2934 j bagh college dentistry vol. 33(2), june 2021 management of trauma 17 cause discomfort to the patient the tooth should only be monitored by clinical and radiographic examination post trauma until the permanent tooth erupts. if the tooth is mobile and the patient causes discomfort the coronal fragment should be removed. if the apical fragment should be left to resorb so as not to disturb the developing permanent tooth (5). the following case was managed in a procedure that may provide primary teeth subjected to trauma a better chance than extraction with a better prognosis. case presentation a four and a half year old boy was subjected to trauma in the anterior segment of the maxilla late in the evening. the cause of the trauma was an accidental fall on another child's head in a chasing game. the child was seen by a dentist at home (author) within the first minute. the following was revealed: a) there was fracture of the alveolar socket wall of the maxilla in the labial cortical plate extending from the area of the primary right lateral incisor to that of the primary left central incisor. the gingiva covering this area was torn off and attached only in the flange area. b) the apices of the roots of the maxillary right primary central and lateral incisors were seen orally displaced labially while their crowns were displaced palataly. c) the maxillary left primary central incisor was fractured at the cervical area. the fracture was oblique extending labialy in the cervical third to the palatal side subgingivally. the fractured segment was attached palatally by few periodontal ligaments. the immediate response was wetting sterile square gauze (shahrazad gauze sponges, china) with normal saline and holding the fractured parts with repositioning them in their position and stabilization by hang grip until a clinic was reached. after reaching a dental clinic local infiltration anesthesia was administered labially and palataly. the whole treatment was modified according to what was available in the clinic of a non-specialized dentist in a rural region. the first step was suturing the torn gingiva using a transverse cutting suturing needle (made for suturing skin and thick tissues) which was the only available type. extreme care was taken during suturing since the soft tissue was already torn and approximating the edges was very difficult. after suturing bleeding was controlled. it was decided to maintain the left primary incisor (the remaining root) although it was not savable but the decision was made to make use of this incisor's root and surrounding bone for stabilizing the fractured parts otherwise its removal will create a hallow space in the alveolar process that will weaken the maxilla anteriorly and cause its collapse in this region. formocresol pulpotomy was carried out for the left central incisor. the third step was fixation of the traumatized teeth to the non-traumatized teeth and this procedure was also modified because stainless steel wire of any type or diameter was not available and at that time it was late at night and obtaining a wire was incapable. the dental needle (septoject xl, septodont, france) is made of stainless steel with a diameter of 0.4mm ( 27 g, 0.40 × 35 ") so two needles were extracted from their plastic base and twisted together in order to gain the strength of a 0.8mm stainless steel wire. it was then bended and adapted to the curvature of the dental arch of the maxilla. light cured composite filling was used to attach the twisted wire to the labial surfaces of the teeth extending from the right primary molar to the left primary canine (figure1). figure 1: suturing of soft tissue and fixation of teeth using two twisted dental needles. during the next day the oral hygiene was improved by continuous mouth washing and irrigating the traumatized region with normal saline. antibiotic therapy was started. the child was then taken to a specialized dental clinic and the procedure of fixation was repeated to replace the twisted wires with a braided retainer wire (ortho technology, usa) (figure 2). figure 2: replacement of twisted wire with a braided retainer wire j bagh college dentistry vol. 33(2), june 2021 management of trauma 18 the child was affected psychologically by the loss of the primary left incisor crown, therefore an impression was done for the fractured segment of this tooth and an identical crown was fabricated using composite (tetric evoceram, ivoclar vivadent, liechtenstein). it was then attached to the wire in the same way of attachment of the wire to the rest of the tooth. in this way the appearance of the anterior teeth was restored (figure 3). figure 3: replacement of the lost left central incisor crown with a fabricated replica. a periapical radiograph for the central and lateral incisors was taken (figure 4) and it revealed fracture of the roots of the right primary central and lateral incisors. two lines of fracture were seen in the central incisor (in the middle and apical thirds) and one fracture line in the middle third of the lateral incisor. figure 4: periapical radiograph showing lines of root fracture in the right primary central and lateral incisors. follow up clinical and radiographic examination was done. the clinical results (as illustrated in figure 5) were healing of the soft tissue and although there was deficiency in gingival extension and root cementum exposure they reduced with time and with the maintaining of good oral hygiene. the color of the teeth (right central and lateral incisors) remained normal which was a sign that the teeth didn’t develop necrosis. the wire was removed 10 months later. the mobility reduced to reach the normal physiological degree (figure 6). figure 5: clinical results of follow-up; aremoval of sutures one week after suturing b, c and d show soft tissue healing (b-2 weeks, c-3 weeks and d-3 months). note the color of the teeth has not changed. figure 6: removal of the wire. after the removal of the wire (10 months later) a final periapical radiograph was taken and it showed normal physiological resorption of the roots of the involved teeth and normal positioning of the developing permanent successors (figure 7). figure 7: follow up x-ray showing normal resorption of the roots (note; the age of the child at this x-ray was 5 years and 2 months) both figures 8 and 9 show the eruption of the permanent central incisors after the exfoliation of the primary incisors. the permanent lateral incisors have not erupted yet. their eruption occurred later on (as shown in figure 10). figure 8: follow up after 2 years clinical view showing eruption of both central incisors (note; the age of the child at this time was 6 years and 10 months) a b c d j bagh college dentistry vol. 33(2), june 2021 management of trauma 19 figure 9: follow up after 3 years clinical view showing eruption of both central incisors (note; the age of the child at this time was 7 years and 1 month) figure 10: follow up after 6.4 years clinical view showing eruption of both central incisors and lateral incisors into occlusion (note; the age of the child at this time was 10 years and 9 months) discussion in general, trauma to primary teeth is a neglected health problem. a meta-analysis on traumatic dental injuries reveals a world prevalence of 22.7% affecting the primary dentition (6). it should be noted that the emergency treatment of this case was by using materials not suitable to suture or to fix this type of trauma in an oral cavity of a young child. the immediate response to position and stabilize the fractured parts within a minute and the use of normal saline during this procedure may have been the reason for minimizing wound infection and intraosseous infection (in addition to the improvement of the oral hygiene). this may have played a role in maintaining the fracture line of the roots of the right central and lateral incisors intact. it may have also minimized the chance of root canal infection which was obvious by the normal color of those teeth that persisted throughout two years. radiographically, absence of internal, external and periapical radiolucency also confirmed the absence of infection in the roots and alveolar bone (5). the decision to not extract the primary teeth was made for many reasons. one of the reasons was to make use of these incisors roots and surrounding bone for stabilizing the fractured parts as described previously in the method. another reason is that premature loss of a primary tooth can lead to eruption problems in the permanent successor tooth, even if treatments are done to recover and maintain space, because there is no way to accelerate the formation of root or stop the eruption of a permanent tooth (having an immature root )(7). the degree of permanent tooth development (in general) does not differ after the extraction of its primary predecessor. an eruption impulse occurs after the extraction of the primary element, regardless of the development stage of the permanent germ or the age of the child. this has been observed when a primary molar is extracted due to infection that has spread to the periapical area followed by the eruption of an under developed premolar in the oral cavity with mobility that may cause the tooth to fall off during mastication (8). malmgren et al stated the importance of treating the traumatized primary dentition in a more conservative approach rather than to advocate routine tooth extraction (5). following a conservative approach may help to reduce the additional suffering for the child and reduce the risk of further damage to the permanent teeth (9). treatment of alveolar process fractures requires manually repositioning the segment of displaced teeth back into proper arch alignment. a very rigid splint would be required for two months. (1). a horizontal root fracture is classified based on the location of the fracture in relation to the root tip (apex) (1). horizontal root fractures may occur in the apical third, middle third, or cervical third of the root. the prognosis worsens the further cervically (towards the crown) the fracture has occurred. tooth fractures are often not apparent during a clinical examination, and can usually only be diagnosed using appropriate radiographs. sometimes radiographs with at least two views are required for making this diagnosis (1). the wire was removed 10 months later. this decision was made not depending on a previous reference. the mobility of the affected teeth reduced to reach the normal physiological degree and after about one year and eight months, two thirds of the roots showed resorption (noted on radiograph). this result was also seen in another study that treated mid-root and apical third horizontal root fracture in both primary central incisors by splinting using orthodontic brackets and stainless steel wire for three months. physiological mobility was obtained and normal root resorption occurred with the eruption of the permanent incisors (10). what appeared to occur due the force of trauma to the primary teeth was seen after the eruption of the permanent left central incisor in the form of turner's hypoplasia. turner's hypoplasia is found in the anterior area of the mouth, the most likely cause is a traumatic injury to a primary tooth. the traumatized tooth, which is usually a maxillary central incisor, is pushed into the developing tooth underneath it and consequently j bagh college dentistry vol. 33(2), june 2021 management of trauma 20 affects the formation of enamel. because of the location of the permanent tooth's developing tooth bud in relation to the primary tooth, the most likely affected area on the permanent tooth is the facial surface. the morphologic and/or mineralization effects of trauma on the permanent successor is highest at an age ranging from 0 to 4 years old and diminishes with aging (6, 11). as conclusion, within the limitations, this case illustrated the favorable prognosis of two primary teeth with root fractures and severely mobile coronal fragments in addition to alveolar bone fracture by a conservative approach. rootfractured primary teeth can be maintained by reduction of tooth mobility and immobilization with a semi-rigid splint. the severity of the sequels is directly related to the degree of permanent tooth formation (child’s age), type of dental trauma and extent of the impact. conflicts of interest the authors has nothing to disclose. references 1. nowak aj, slayton ri. trauma to primary teeth: setting a steady management course for the office. contemp ped arch 2002; 11:99-110. 2. yagot kh, nazhat ny, kuder sa. traumatic injuries in nursery school children from baghdad, iraq, community dent oral epidemiol 1988; 16(5): 292-3. 3. prithviraj, bhalla hk, vashisht r, regish km, prema. an overview of management of root fractures. kathmandu univ med j 2014; 47(3):21725. 4. hegde v, chandawalla e. exploration of various avenues in diagnostic and treatment modalities in the management of horizontal crown-root fractures: case reports. endodontology 2014; 26(1): 194-203. 5. malmgren b, andreasen jo, flores mt, robertson a, diangelis aj, andersson l, cavalleri g, cohenca n, day p, hicks ml, malmgren o, moule aj, onetto j, tsukiboshi m. international association of dental traumatology guidelines for the management of traumatic dental injuries: 3. injuries in the primary dentition. dental traumatology 2012; 28: 174-182. 6. glendor u. epidemiology of traumatic dental injuriesa 12 year review of the literature. dent traumatol 2008; 24: 603-11. 7. miranda c, luiz bkm, cordeiro mmr. consequences of dental trauma to the primary teeth on the permanent dentition rsbo. 2012 oct-dec; 9(4):457-62. 8. fanning ea. effect of extraction of deciduous molars on the formation and eruption of their successors. angle orthodont. 1962; 32:44-53. 9. day pf, duggal ms. a multicenter investigation into the role of structured histories for patients with tooth avulsion at their initial visit to a dental hospital. dent traumatol 2003; 19: 243-7. 10. liu x, huang j, bai y, wang x, baker a, chen f, wu la. conservation of root-fractured primary teeth--report of a case. dent traumatology 2012; 29(6):498-501. 11. broadbent jm, thomson wm, williams sm. does caries in primary teeth predict enamel defects in permanent teeth? a longitudinal study. j.dent res. 2005; 84: 260–4. المستخلص والدائمة المقدمة: األساسية األسنان إصابة المحيطةتعد أو واالنسجة الصعب من يكون ما عادة األطفال. عند شيوًعا األسنان مشكالت أكثر أحد عدم الصغير وقلة تعاون المريض(. لذلك يجب أن يحدث الشفاء على الرغم من الفمفي األسنان األولية )بسبب حجم التثبيتة المستحيل القيام بعملي . هذه الدراسة عبارة عن السن، مما يؤدي عادةً إلى تداخل األنسجة الضامة. في بعض الحاالت ، سوف تحدث العدوى في لب ثبات منطقة الكسر عند طفل عمره أربع سنوات. تسببت الصدمة في كسر في تيجان وجذور األسنان األمامية م الفك األمامية وعظ اللبنيةتقرير عن حالة صدمة لألسنان أفضل. نسبة توقع نجاح العالجمع قلعهالمعرضة للصدمة فرصة أفضل من اللبنية الحالة التالية في إجراء قد يوفر لألسنان الجةمع. تمت اللبنية كانت خياطة األنسجة الرخوة الممزقة هي تعرض طفل في الرابعة والنصف من العمر الصابة في المنطقة االمامية للفك العلوي. المواد والطريقة: تثبيت سلك معدني عن طريق االيمن اللبني والجانبي الوسطي. تم تثبيت القاطع االيسر اللبني تحنيط العصب للسن القاطعحشوة ولى تليها الخطوة األ .واربعة اشهر سنوات ست واإلشعاعية لمدة. تم إجراء المتابعة السريرية باستخدام مادة حشوة ضوئية بعد أسبوع واحد واستكمل بعد شهرين. استمر تثبيت األسنان لمدة عشرة أشهر. ظلت خطوط الكسر في الجذور النتائج: لوحظ شفاء األنسجة الرخوة . سريريا لم يكن هناك أي عالمة على أي التهاب اللب أو نخر. من الناحية اإلشعاعية ، ال يمكن رؤية أي عالمات لإلصابة باألنسجة موقعهافي ثابتة في العظم السنخي ، وال يحدث ارتشاف خارجي أو داخلي للجذر أيًضا. بعد عشرة أشهر انتهى التثبيت وتمت إزالة المحيطة ، وال يحدث ارتشاف القواطع بزغتسنوات 3السلك. في ذلك الوقت كان هناك ارتشاف طبيعي لجذور القواطع األولية فيما يتعلق بالتطور الطبيعي للقواطع الدائمة. بعد القواطع األربعة الدائمة في مكانها الطبيعي. اكتمل بزوغسنوات ، 5عها الطبيعي. بعد المركزية الدائمة في وض داعيات الخالصة: يمكن عالج األسنان األولية التي تعاني من كسور في الجذر وشظايا االكليلية شديدة الحركة من خالل نهج متحفظ. ترتبط شدة الت )عمر الطفل( ونوع صدمة األسنان ومدى التأثير.بشكل مباشر بدرجة تكوين األسنان الدائم .، التاج المكسور والجذر اللبنيةالكلمات المفتاحية: الصدمة ، القواطع articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. http://www.ncbi.nlm.nih.gov/pubmed/?term=liu%20x%5bauthor%5d&cauthor=true&cauthor_uid=23067514 http://www.ncbi.nlm.nih.gov/pubmed/?term=huang%20j%5bauthor%5d&cauthor=true&cauthor_uid=23067514 http://www.ncbi.nlm.nih.gov/pubmed/?term=bai%20y%5bauthor%5d&cauthor=true&cauthor_uid=23067514 http://www.ncbi.nlm.nih.gov/pubmed/?term=wang%20x%5bauthor%5d&cauthor=true&cauthor_uid=23067514 http://www.ncbi.nlm.nih.gov/pubmed/?term=baker%20a%5bauthor%5d&cauthor=true&cauthor_uid=23067514 http://www.ncbi.nlm.nih.gov/pubmed/?term=chen%20f%5bauthor%5d&cauthor=true&cauthor_uid=23067514 http://www.ncbi.nlm.nih.gov/pubmed/?term=wu%20la%5bauthor%5d&cauthor=true&cauthor_uid=23067514 http://www.ncbi.nlm.nih.gov/pubmed/23067514 ehsaan f.doc j bagh college dentistry vol. 25(3), september 2013 comparison of fit restorative dentistry 14 comparison of fit among different types of post restorations luted with conventional cement ehsaan s. al-mustwfi, b.d.s. (1) haitham j. al-azzawi, b.d.s., m.sc. (2) abstract background: with the advent of new postmaterial in dentistry, it has become important to measure fitness of post restoration along the horizontal plane of the root space.this study aimed to measure and compare, the cement film thickness of conventional zinc phosphate cement in micrometer between the post and root dentin along horizontal plane at different post space regions (coronal, middle and apical) of four types of posts, by using stereomicroscopy. material and methods: thirty-two extracted human maxillary canines, mandibular canines and maxillary central incisors (n=32) were instrumented with protaper system files (hand use) and obturated with gutta-percha for protaper and ah26® root canal sealer. after 24hrs of incubation at 37ºc, post space was prepared using frc postec® plus drills no.3 and er cera reamer size 70, creating 10 mm deep post space. the prepared samples were then randomly divided into four main groups (8 samples each) according to the type of post used (group a: fabricated cast metal post), (group b: fabricated zirconia post), (group c: prefabricated glass fiber reinforced composite post), (group d: prefabricated zirconia post). after cementation and incubation period of 24hrs, each root was sectioned horizontally into 3 discs (2mm in thickness) at the coronal, middle and apical regions of the root space. the cement thickness between post and root dentine was measured (in µm) by using a stereomicroscope. results: the results of this study showed that the lowest mean of cement thickness was in group c (35.28μm), followed by group a (78.12μm) and group d (81.9μm), and all three groups demonstrated acceptable cement thickness, while group b produced unacceptable cement thickness (127.34μm). one way anova test revealed a statistically highly significant difference for the cement thickness among four post types used within each region of the root. conclusions: the root region and type of post system have an effect on cement thickness along post space. keywords: cast metal post, zirconia post, fiber post, root region. (j bagh coll dentistry 2013; 25(3):14-18). introduction in most of endodontically treated teeth, the amount of coronal tooth structure remaining is often limited as a result of trauma, caries, prior restoration and endodontic access procedures.the choice of an appropriate restoration for endodontically treated anterior teeth is guided by the strength and esthetics (1). historically, cast posts were more commonly used than prefabricated posts, but over many decades, cast posts have become much less popular. when there is wide, noncircular (oval canal), or extremely tapered canals, cylindrical prefabricated posts may not achieve adequate adaptation (2).however, the fabricated cast metal posts have fit adaptation, high retention and thin cement layer, but the base metal alloy has corrosion and allergic reactions (3). moreover, the increasing demand for more esthetically and biocompatible restorations has led to the development of tooth-colored, translucent, metal-free postsystems (4). the type of zirconia used for dental post is composed of ytzp (yttrium tetragonal zirconium polycrystals).the physical and mechanical properties of zirconia posts could increase the strength of the tooth (5). an alternative to cast post and zirconia, fiber posts have been introduced in the early 1990s to restore endodontically treated (1) m.sc. student, department of conservative dentistry, college of dentistry, university of baghdad. (2) professor, department of conservative dentistry, college of dentistry, university of baghdad. teeth with an excessive loss of dentinal structure, because their elastic modulus is claimed to be similar to that of the dentin; therefore, displayed higher survival rates when compared with teeth restored with zirconia posts (6), have good mechanical and biocompatibility properties(7). like all prefabricated posts, prefabricatedfiber posts are designed so that a circular post is produced, and therefore an unnecessary amount of dentin has to be removed (2).the cement must have homogeneous biomechanical unit to allow more uniform stress distribution, better preserves the weakened tooth structure, reduces microleakage at the dentin–cement interface, and reduces secondary caries and re-infection of the periapical area (8). the thin layer will flow into the internal surface irregularities between post and tooth structure, resulting in greater retention (9). materials and methods sample selection: thirty-two freshly extracted human teeth (maxillary canines, mandibular canines and maxillary central incisors). the teeth were straight root, no caries, no fractures, cracks or external resorption by examination with 10x magnifying eye lens and light cure device. samples preparation: the length of the root was marker (15 mm) and sectioned parallel to the cemento-enamel junction. plastic test tube was used as a mold to hold ofspecimens. the rootswere placed with the aid of simple dental j bagh college dentistry vol. 25(3), september 2013 comparison of fit restorative dentistry 15 surveyor (j.m.ney, u.s.a.) the long axisof the roots parallel to that of plastic tubes. endodontic treatment: root canal instrumentation was performed using protaper hand files (dentsply, switzerland) in crown down technique. irrigation performed using of 2.5% naocl after every change of file size throughout thecleaning and shaping of the root canals, dried with paper points and filled with gutta-percha for protaper f3 (dentsply, switzerland) and ah26® root canal sealar (dentsply, germany). the excess gutta-percha at the canal orifice was removed.the accessopening were sealed with temporary fillingmaterial, and stored at 37ºc, 100% humidity in an incubator (memmert, germany) for 24hr. sample grouping: after that the roots were randomly assigned into four groups (n=8each), depending on the type of post used (group a: fabricated cast metal post(hi-chromsoft-7, japan), group b: fabricated zirconia post (zirconzahn, italy), group c: prefabricated glass fiber reinforced composite post (ivoclar vivadent, france), and group d: prefabricated zirconia post (komet, germany)), and then each group was subdivided into three groups (n=8 each), according to the root region (coronal, middle and apical). fig.1. digital images in middle region a) post b) cement c) root structure root space preparation: after 24hrs,the guttapercha was removed by pesso drills no.1, ingroups a, b, and cthe canal walls prepared with frc postec®plus drills no.3 (ivoclar vivadent, france).in group d the canal walls were prepared with cera post reamer size 70 (komet, germany).the preparation was performed under copious water coolingwith handpiece attached to modify dental surveyor (cendres & metaux, switzerland) to creating (10 mm) deep post space measured from the coronal end of the root.keeping 5 mm of gutta-percha apically. construction of fabricated cast metal post and core: it was casted from a direct wax pattern, blue inlay wax type ii (degussa, germany) fabricated in the root samples, phosphate bonded investment(yeti dental, germany)was vacuum mixed,then the wax patterns were coated with the investment material using the brush technique and allowing the investment to set for 1 hour. after that the ring was placed in a cold furnace (combilabor, germany) and the temperature was set for 480 °c soaked for 15 minutes. the temperature was then raised to 650 °c and held for another 15 minutes before raising it to 950 °c and holding for another 15 minutes.the ring was removed from furnace at the time of nickel based alloy melted in electrical centrifugal casting machine (dentaurum, germany). then the cast post was tried to fit by using a disclosing agent, if a pressure spot was detected it was adjusted with carbide bur to obtain a passive fit (10). construction of fabricated zirconia post and core: eight metal posts and core were constructed using the same procedure as in cast metal group and fixed in in the holding plate of the copy milling machine(zirconzahn, italy). the milled structure is 30% larger than the metal pattern as zirconia undergoes shrinkage of 30% after sintering of milled restorations. the copy was then sintered in furnace (zirkonofen 600, italy)prior to the sintering process (8-hours):from room temperature to 1500°c ë 4-hours,hold time at 1500°c for 2hours, andcooling-down phase up to room temperature 2-hours.after that it adjusted by using a disclosing agent. if a pressure spot was detected it was adjusted with diamond bur to obtain a passive fit (1). post cementation: the de tray zinc phosphate cement (dentsply, germeny) was mixed and a constant load of (4.5kg) was applied for (10 minutes), using a custom-made loading apparatus. after setting the roots were stored in distilled water for 24 hours at 37°c in an incubator. preparation of the specimens for sectioning: the roots were removed from moldand the apical end of the roots was fixed in the plastic piston of the syringe with a composite resin material by using a simple dental surveyor and loading the syringe with cold acrylic.the sectioning of the root was made by using a diamond disc (komet, germany) mounted on special custom cutting machine (12000 rpm).the cuts were made under heavy flow of water (19-25°c) to minimize the smearing (11). from each specimen, 3 discs (coronal, middle, and apical) were obtained, each (2 mm) in thickness. measurement of film thickness: the cement thickness measured at four indentations at the midpoint of buccal, mesial, lingual and distal surfaces by a stereomicroscope (hamilton, italy) a b group a b c a group b group c group d c b a b a c c j bagh college dentistry vol. 25(3), september 2013 comparison of fit restorative dentistry 16 are shown in (figure 1). the microscope was calibrated to 2.5 mm (2500µm) at magnification 40x. all readings were recorded and converted to (µm) by a magnification factor, depending on two readings of two persons and taking the mean of the two readings to assure accuracy. to overcome errors in readings, measurements repeated 4 times (12). statistical analysis: all statistical analysis was performed using commercially available software (spss for windows) version 15. results 1. the measurement of cement thickness of four groups at three regions: the mean of cement thickness at different root regions are shown in (figure 2), in both fabricated posts the apical regions have higher mean, followed by middle regions, while the lowest value seen at the coronal region and in both prefabricated posts the coronal regions have higher mean, while middle region of group c had the lowest than apical region, while the middle region of group d had highest mean than apical region. the highest mean could be seen at the apical region of group b, while the lowest value seen at the middle region of group c. in the first analysis, one-way anova test revealed that the cement thickness was significantly affected by the different regions of the post space, a very highly significant difference (p<0.001) within each regions of root at same type of the post used. in the second analysis, one-way anova test revealed that the cement thickness was significantly affected by the different regions of the post space, a very highly significant difference (p<0.001) among different regions of root within the four post types used. 2. the measurement of cement thickness of four groups: the mean of cement thickness at all root regions are shown in (figure 3), the highest mean was seen in group b, followed by group d and group a, while the lowest value was seen at group c. one-way anova test revealed that the cement thickness was significantly affected by the post types used, a very highly significant difference (p<0.001) in mean of cement thickness values among the four post types. discussion contemporary post types can be divided into two subgroups according to the technique approach used to prepare the root prior to cementation. the first group, prefabricated posts are usually used for the direct technique where the post insertion and core build-up are performed at the same appointment. in the second group, fabricated posts are usually used for the indirect technique, where the post space prepared, preserving as much dentin as possible and taking an impression of the prepared canal, the dental laboratory technician fabricates the post and core; these steps require at least two visits (10).there are two main reasons for the failure of teeth restored with post are firstly poor marginal adaptation between post and dentine of root structure which clinically leads to a higher incidence of coronal bacterial leakage or secondary caries and the second reason is fracture of the remaining dental hard tissue. adequate adaptation of restorations improves longevity and reduces the risk of restoration misfit associated with periodontal disease (13). one of the main criteria to evaluate the adequacy of a restoration is marginal fit. the success of post restorative procedures depends in part, on the thickness of the cement used to create a link between the post and root canal dentin. the fit is typically measured by the cement thickness between post and dentin of root structure. the method of horizontal cement thickness between fig. 2. bar-chart graph showing the mean values of cement thickness of different groups and subgroups 0 50 100 150 200 a b c dce m e n t th ic kn e ss in µ m post types coronal middle apical fig. 3. bar-chart group showing to the mean values of cement thicknessfor total values of four groups 0 50 100 150 a b c d c e m e n t th ic kn e ss µ m post types j bagh college dentistry vol. 25(3), september 2013 comparison of fit restorative dentistry 17 structures was used. in this study four types of posts were used: two fabricated posts and two prefabricated posts. the fitness was analyzed for different post systems in canals with oval shape of natural human maxillary central incisor, maxillary canine and mandibular canine roots. the maximum film thickness of zinc phosphate cement between two flat surfaces is 25 µm according to (ada specification no. 96), and the current iso 9917 standard requires a film thickness at the time of seating inferior to 25 µm for water-based luting cements. in this in vitro study, the prefabricated glass fiber reinforced composite system mean of cement thickness was (35.28μm), followed by the fabricated cast metal systems (78.12μm), and followed by the prefabricated zirconia system (81.9μm), and all three groups demonstrated acceptable cement thickness while the fabricated zirconia system produced unacceptable cement thickness (127.34μm) according to previous researches (1416) that suggested that 120 μm should be the highest limit for clinically acceptable cement thickness.the four systems showed a large variation in cement thickness values: fabricated cast metal post and fabricated zirconia post: a standardized construction technique could not be obtained because of the difference in their procedure, materials and equipment during post fabrication technique. the cement thickness demonstrated the higher values for the apical region and the lowest values for the coronal regions of the post space. the construction technique in apical region of post required adjustment because of on passive fitted of post and when adjusted may reduction dimension in the end related to the direction of view to the operative site. the fabricated cast metal post was a combination of two techniques, the lost-wax and casting techniques; therefore, it may undergo minor dimensional changes caused by the use of a separating medium before waxing of the post and the minor shrinkage during solidification of the wax, but the expansion of the investment and dimensional changes of the metal may be adequate to compensate for the metal casting shrinkage and obtaining a desirable cement thickness (78.12μm).the results disagree with yüksel and zaimoğlu (17) who suggested that the mean of cement thickness of casting copings (96.5 µm), this value was higher than those obtained in this study, and the difference may be related to the difference in material used. thefabricated zirconia post produced unacceptable cement thickness (127.34μm), which may be due to: 1. the cement thickness might be influenced by the separating medium that was used during the fabrication of copying metal post. 2. the copying metal post may undergo dimensional changes after melting and casting metal alloy. 3. the machining of zirconia blank may be inadequate to compensate for the shrinkage occurring after sintering of blank. 4. dependence on the skill of the laboratory technician. 5. the no passive fit of the milled zirconia posts. repeated adjustments were necessary, as was subsequent post sintering, to passive fit of the posts into the canal. the results agree with dietschi et al. (18), who investigated the marginal adaptation of different post types to root dentin, it was reported that the fabricated zirconia post presented the highest cement thickness proportion compared to other post types. the results disagree with adriana et al. (19) who suggested that the mean of cement thickness of restoration fabricated by using the copy milling machine of zirkonzahn was (22.8 μm) with using cement, and the difference may be related to type of cement and load apply for cementation. prefabricated glass fiber reinforced composite post and prefabricated zirconia post: in these groups, all steps that might have caused the dimensional changes are not found. the shape of drill used to prepare root space is coincident with the post design according to manufacturer's instructions to provide better canal adaptation and thus the lower values for (the middle region in prefabricated glass post and the apical region in prefabricated zirconia post), and the highest values for (the coronal regions of root space).the lower thickness in prefabricated glass fiber post (35.28μm) was probably because of technological development and new material, the taper shape and passive design of posts which conforming to the original shape of the root space and obtaining a good fit. the results agree with schmagea et al. (20) who suggested that the mean of cement thickness of greater taper prefabricated post was ranging between 33 and 48 mm with using zinc phosphate cement. the shape and passive design of prefabricated zirconia posts manufacture for canal adaptation and obtaining a desirable thickness (81.9μm).this coincides with stricker and göhring (21) who reported that prefabricated glass fiber and ceramic post had a positive effect on marginal adaptation. comparison between fabricated groups: the different in manufacturing processes may affect on the cement thickness results (22).the lower in j bagh college dentistry vol. 25(3), september 2013 comparison of fit restorative dentistry 18 the fabricatedcast metal system was due to fewer laboratory steps: (convert of wax to metal), while in fabricated zirconia system (convert of wax to metal and then convert of metal to zirconia). the expansion and contraction properties of the various materials used in the fabrication of coping metal post, combined with the complex fabrication steps of the milling process; the sintering process inadequate to compensated 30% shrinkage of pre-sintered zirconia pattern and difficult to obtain an acceptable fit of a fabricated zirconia system. comparison between prefabricated groups: the shape of drill used for preparation of root space different according to manufacture instruction, is greater taper in prefabricated glass fiber reinforced composite post to obtain thinner cement thickness at middle of root canal space and taper drills shape in prefabricated zirconia post to obtain thinner cement thickness at increasing root canal depth. references 1. nurit b, thomas h, anthony r. evaluation of a onepiece milled zirconia post and core with different postand core systems: an in vitro study. j prosthet dent 2010; 103: 369-79. 2. rönnlöic an. fiber-reinforced composite as root canal posts. a master thesis, prosthetic dentistry and biomaterials science, institute of dentistry, university of turku, finland, institute of dentistry, 2007. 3. meira jbc, espo´ sito com, quitero mfz, poiate iavp, pfeifer csc, tanaka cb. elastic modulus of posts and the risk of root fracture. dent traumatol 2009; 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22(4): 374-7. intisar f.doc j bagh college dentistry vol. 27(3), september 2015 studying the effect restorative dentistry 22 studying the effect of addition a composite of silanized nano-al2o3 and plasma treated polypropylene fibers on some physical and mechanical properties of heat cured pmma denture base material omar r. muklif, b.d.s. (1) intisar j. ismail, b.d.s., m.sc., ph.d. (2) abstract background: polymethyl methacrylate (pmma) is the most commonly used material in denture fabrication. the material is far from ideal in fulfilling the mechanical requirements, like low impact and transverse strength, poor thermal conductivity. the purpose of this study was to evaluate the effect of addition a composite of surface treated nano aluminum oxide (al2o3) filler and plasma treated polypropylene fiber (pp) on some properties of denture base material. materials and methods: one hundred fifty prepared specimens were divided into 5 groups according to the tests, each group consisted of 30 specimens and these were subdivided into 3 groups (unreinforced heat cured acrylic resin as control group),reinforced acrylic resin with( 0.5%wt nano al2o3 and2.5%wt plasma treated pp fibers) group and reinforced acrylic with(1%wt nano al2o3 and 2.5%wt plasma treated pp fibers group).the tests were impact strength, transverse strength, indentation hardness(shore d), surface roughness thermal conductivity. the results were statistically analyzed using anova test. results: a highly significant increase in impact strength, surface hardness, thermal conductivity with the addition of 0.5%wt. (al2o3) and 2.5%wt pp fiber to(pmma),also there is a significant increase in surface roughness and non significant increase in transverse strength. at the concentration of 1%wt nano (al2o3)and 2.5%wt pp fiber there is a highly significant increase in impact strength surface hardness and thermal conductivity. non-significant differences were shown in transverse strength and significant increase in surface roughness. conclusion: the addition of a composite of al2o3 nanoparticles and pp fiber to pmma improves the impact strength, surface hardness and thermal properties, surface roughness while non-significant difference in transverse strength. key words: acrylic resin, alumina nanofillers, polypropylene fibers, plasma treatment. (j bagh coll dentistry 2015; 27(3):22-27). introduction the goal of dentistry has been to replace or restore lost or damaged tooth structure satisfying esthetic and functional requirements. dentures remain the most popular choice of prosthetic devices. dentures made from resin based polymeric systems were popular because of their ability to be molded with ease with excellent esthetic appearance and suitable mechanical characteristics in most clinical conditions (1). this material is not ideal in every respect and it is the combination of virtues rather than one single desirable property that accounts for its popularity and usage. despite satisfying esthetic demands it is far from ideal in fulfilling the mechanical requirements of prosthesis. however, a polymer needs some modifications in its structure or physical properties to obtain a superior range of functions. one modification technique is adding fillers to a polymer to generate a composite with improved properties, such as enhancement in mechanical strength electrical conductivity or thermal stability (2). (1) m.sc. student, department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor, department of prosthodontics, college of dentistry, university of baghdad. the filler materials include organic, inorganic, and metallic particulate materials in both micro and nano sizes. various kinds of polymers and polymer-matrix composites reinforced with metal particles have a wide range of industrial applications (3). organic-inorganic hybrid nanocomposite materials have been studied in recent years, with the expectation that nanocomposite material will serves an important and evolutionary means of achieving properties that can not be realized with single material (4). nanocomposites have the potential to be implemented as a new high strength matrix in a composite (5). these composites are desired due to their low density, high corrosion resistance, ease of fabrication, and low cost (6). the inclusion of inorganic fillers like alumina into polymers is primarily aimed at the cost reduction and stiffness improvement (7). fiber reinforced polymer composites (frpcs) have generated wide interest in various engineering field because of high specific strength, high modulus, low density and better wear resistance (8).the concept of combining nanocomposites as matrix material with fiber reinforcement in a new three-phase composite reinforcement has been shown to be very successful. lighter, thinner, stronger, and cheaper structures are the goals of j bagh college dentistry vol. 27(3), september 2015 studying the effect restorative dentistry 23 materials science and engineering applications nowadays (9). materials and methods before starting the tests pp fiber and nano alumina should be under go surface treatment separately to improve the adhesion with pmma matrix. the alumina nanoparticles were surfacetreated with a silane coupling agent (10), while pp fiber undergo surface treatment by oxygen plasma (11). one hundred fifty acrylic specimens were constructed by conventional flasking technique using heat cure acrylic resin, the samples were divided into five groups according to the using tests and each group sub divided into three subgroups. mechanical and physical tests a. impact strength test the specimens were prepared with dimensions (80mm x 10mm x 4mm) (iso 179, 2000) for unnotched specimens. specimens were stored in distilled water at 370c for 48 hours before being tested (12).the impact strength test was evaluated following the procedure recommended by the iso 179 with impact testing device. the specimens were supported horizontally at each end and struck by free swinging pendulum of 2 joules. the scale readings give the impact energy in joules.the charpy impact strength of unnotched specimens was calculated in kilo joules per square meter by the following equation: impact strength = x103 (iso, 2000) e : the impact energy in joules, b: is the width of the specimens in millimeters, d : is the depth of the specimens in millimeters fig. 1: impact strength test b. transverse strength test specimens were prepared with dimensions (65mm x 10mm x 2.5 + 0.1mm). all specimens stored in distilled water at 37 0c for 48 hours before being tested (12).the test was performed using instron universal testing machine (wdw200 e), each specimen was positioned on the bending fixture which consist of two parallel supports (50 mm apart), the full scale was 50 kg and the load was applied with across head speed of1mm/min. by a rod placed centrally between the supports making deflection until fracture occurs. c. surface hardness test specimens of heat cure acrylic resin were prepared with a dimension (65mm x 10mm x 2.5 + 0.1mm). all specimens were stored in distilled water at 37ºc for 48 hours before being tested (12). surface hardness was determined by using (shore d) durometer hardness tester which is suitable for acrylic resin material .the instrument consist of spring loaded indenter (0.8mm in diameter), the indenter is attached to digital scale that is graduated from 0 to 100 units. the usual method is to press down firmly and quickly on the indenter and record the reading. three readings were done on each specimen (one in the center and other at each end) then the mean of three readings was calculated. d. surface roughness test specimens with dimensions (65mm x10mm x 2.5+ 0.1mm) were prepared to be used for surface roughness test. all the specimens were stored in distilled water at 370c for 48 hours before being tested(12).the profilometer device was used to study the effect of fiber reinforcement on the microgeometry of the test surface. this device is supplied with sharp stylus surface analyzer from a diamond to trace the profile of the surface irregularities by recording of all the peaks and recesses which characterized the surface by its scale. the acrylic specimen was placed on its stable stage and the location of the tested area was selected (the specimen was divided into three parts) then the analyzer was traversed along the tested area and the mean of three readings was calculated. e. thermal conductivity tests disc with dimension (40 mm in diameter and 2.5 mm in thickness) according to instrument specification. the hot disk thermal constant analyzer can be used for measuring thermal transport properties of a large variety of materials with thermal conductivities ranging from 0.005w/m.c (evacuated powders) to 500 w/m.c (graphite). naturally the parameter heating power measuring time and radius of disk, by which experiment are controlled and must be selected with care in order to arrive at results within the given limits of accuracy. the hot disk sensor j bagh college dentistry vol. 27(3), september 2015 studying the effect restorative dentistry 24 consist of an electrically conducting pattern in the shape of double spiral extend out of a thin sheet of nickel. the nickel foil was chosen because of its high and well known temperature coefficient of resistivity. the conducting pattern was supported on both sides with thin electrically insulating material. the equipment connected to computers that are programmed for the test. by selection experiment type and setting for that type, the method will be selected automatically. the experiment was called tps (transient plane source). fig. 2: thermal conductivity test machine results the results obtained from the measured data were computerized using spss system for statistical analysis and classified according to the followings experimental groups: group (a) control group group (b) acrylic resin+[al2o3(0.5)+pp(2.5)]wt% group (c) acrylic resin +[al2o3(1)+pp(2.5)]wt% impact strength test the mean, standard deviation (s.d) and standard error (s.e) of impact strength for the control and experimental groups of acrylic resin shown in table (1)for different groups of the different concentrations of the nano fillers that had been added(0.5wt% and 1wt%) while the pp fiber is (2.5%wt). transverse strength test: the mean, standard deviation (s.d) and standard error (s.e) of transverse strength for the control and experimental groups of acrylic resin shown in table (2). surface hardness test the surface hardness of 10 specimens for each group were examined. the mean, standard deviation (s.d) and standard error (s.e) of surface hardness for the control and experimental groups of acrylic resin shown in table (3). surface roughness the surface roughness of 10 specimens for each group were examined. the mean, standard deviation (s.d) and standard error (s.e) of surface roughness for control and experimental groups of acrylic resin shown in table (4). thermal conductivity table (5) shows the means, standard deviations, standard error of the means, minimum and maximum values of experimental specimens measuring thermal conductivity in different concentrations of al2o3 nanoparticles. table 1: descriptive data of impact strength test among studied groups studied groups n mean (kj/m2) s.d. s.e. minimummaximum control group (0.wt%) 10 8.2000 1.46210.46236 6.05 10.61 [al2o3(0.5)+pp(2.5)]wt% 1016.87102.37828.75208 11.62 19.69 [al2o3(1)+pp(2.5)]wt% 1017.94801.06345.33629 16.15 19.70 table 2: descriptive data of transverse strength test among studied groups studied group n mean (n/mm2) s.d. s.e. minimum maximum control group (0.wt%) 10 95.0510 6.65029 2.10301 87.21 106.30 [al2o3(0.5)+pp(2.5)]wt% 10 96.9380 7.34547 2.32284 87.25 106.36 [al2o3(1)+pp(2.5)]wt% 10 90.7800 3.78578 1.19717 84.81 97.43 j bagh college dentistry vol. 27(3), september 2015 studying the effect restorative dentistry 25 table 3: descriptive data of surface hardness test among studied groups studied groups n mean (no.) s.d. s.e. minimummaximum control group (0.wt%) 10 83.8150 1.31404 .41554 81.75 86.00 [al2o3(0.5)+pp(2.5)]wt% 10 86.1100 .54508 .17237 85.10 86.80 [al2o3(1)+pp(2.5)]wt% 10 87.3350 .46729 .14777 86.50 88.35 table 4: descriptive data of surface roughness test among studied groups. studied groups n mean (µm) s.d. s.e. minimummaximum control group (0.wt%) 101.3423.11410 .03608 1.19 1.48 [al2o3(0.5)+pp(2.5)]wt% 101.4986.12651 .04001 1.29 1.69 [al2o3(1)+pp(2.5)]wt% 101.5096.15986 .05055 1.23 1.69 table 5: descriptive data of thermal conductivity parameters analysis (w/m.c) studied groups n mean (w/m.c) s.d. s.e. minimummaximum control group (0.wt%) 10 .0950 .01882 .00595 .06 .11 [al2o3(0.5)+pp(2.5]wt% 10 .1454 .02941 .00930 .09 .17 al2o3(1)+pp(2.5)]wt% 10 .2244 .05524 .01747 .12 .26 discussion impact strength impact strength is a measure of the energy absorbed by unit area of a material when it is broken by a sudden blow (13). impact failure is a predominant mode of denture failure. the results of impact strength test as shown in table (1) revealed that the addition of silanized nano al2o3 and plasma treated polypropylene fiber increased the value of the impact strength compared to control group. the increase in impact strength due to the interfacial shear strength between nanofiller and matrix is high due to formation of cross-links or supra molecular bonding which cover or shield the nanofillers which in turn prevent propagation of crack. also the crack propagation can be changed by good bonding between nanofiller and resin matrix (14). on the other hand plasma treated polypropylene fiber play an important role in the increase in impact strength. this increase which could be related to the presence of fibers which prevent the crack propagation and change in direction of cracks resulting in smaller cracks between the fibers, this can be correlated to the increased impact strength of fiberreinforced specimens compared to the control group where there is unobstructed crack propagation. these results are in agreement with results obtained by mowade et al. (2). transverse strength although there was a slight increase transfers strength of pmma reinforced with nano al2o3 and pp fiber; but it was statistically not significant difference in transverse strength mean value compared with control group table (2). it clearly indicates that inclusion of alumina reduces the load carrying capacity of the composite specimen. this may be due to the stress concentration at the sharp corners of irregular alumina particles. possible explanations for this reduction in strength could be: stress concentration because of too many filler particles; changes in the modulus of elasticity of the resin and mode of crack propagation through the specimen due to an increased amount of fillers (15). such defects can catalyze the failure process and might be an area in which crack propagation is initiated. on the other hand, the results revealed that the addition of pp fibers produced non significant difference in transverse strength mean value compared with the control group, this may be related to the fact that the random orientation of fibers allows only small portion of the reinforcement to be directed perpendicular to the applied stress (16). jasim incorporating silanized alumina nanofillers into conventional heat-cured denture base resin results in an increase in transverse strength (17). mohammed found that there was a non significant difference in transverse strength after incorporation of plasma treated pp fiber (18). surface hardness it was found in this study that hardness value showed a highly significant increase with 0.5wt%, 1wt % alumina nanoparticles compared with control group. this increase in hardness may due to inherent characteristics of the al2o3 j bagh college dentistry vol. 27(3), september 2015 studying the effect restorative dentistry 26 nanoparticles. al2o3 possesses strong ionic interatomic bonding, giving rise to its desirable material characteristics, that is, hardness and strength (15). on the other hand, the addition of pp fibers produce an increase in surface hardness mean value compared with control group; this increase could be related to the presence of these fibers near or at the surface of the composite which extremely hard and stiff (19). jasim concluded that there was a highly significant increase in surface hardness when al2o3 was added to heat cure acrylic resin with different percentages (1wt%, 2wt% and 3wt%) (17). mohammed concluded that after reinforcement with oxygen plasma treated pp fibers there was a highly significant increase in surface hardness (18). surface roughness table(4) showed that the surface roughness of the acrylic denture base was significantly change when different percentages of silanized nanoparticles and poly propylene fiber were added , the effect of nanoparticles is less than that of fiber may be due to that the alumina nanoparticles have very small size and well dispersion (20).on the other hand, the significant increase in surface roughness mean value of specimens after incorporation of plasma treated pp fibers compared with control group, this increase could be attributed to fact that oxygen – plasma treatment increase the surface roughness of treated polymer(11). thermal conductivity test table (5) was showed that there was a highly significant increase in the values of thermal conductivity with the addition of alumina nanoparticles. this may due to overlapping of thermal conductive nanoparticles inside the polymer matrix to bridge the insulating effect of pmma matrix .the increase in the amount of fillers make the nanoparticles approximate from each other and increase overlapping of thermal conductive particles that form pathway and permit transition of heat from one side of specimens to another side thus increasing thermal conductivity. the result of this study coincide with the results of marie et al in 1994 when they added thermal conductive fillers (al2o3) to pmma and found increase in the thermal conductivity (21). jasim concluded that there was highly significant increase in thermal conductivity compared to control groups after incorporation of nano al2o3 (17). polymers typically have intrinsic thermal conductivity much lower than those for metals or ceramic materials, and therefore are good thermal insulators (22). so pp fibers have little or no effect on thermal conductivity in this study. references 1. meng tr, latta ma. physical properties of four acrylic denture base resins. j contemp dent pract 2005; 6: 93-100. 2. mowade t k, dange sh p, thakre m b, kamble v d effect of fiber reinforcement on impact strength of heat polymerized polymethyl methacrylate denture base resin: in vitro study and sem analysis. j adv prosthodont 2012; 4(1): 30-6. 3. jungil k, kang ph, yc nho. positive temperature coefficient behavior of polymer composites having a high melting temperature. j appl polym sci 2004; 92: 394–401. 4. novak bm. hybrid nanocomposite material between inorganic and organic polymer. adv mater 1993; 5 : 422-33. 5. gotro j. thermosets encyclopedia of polymer science and technology 2004; 12: 207-60. 6. zhu k, schmauder s. prediction of the failure properties of short fiber reinforced composites with metal and polymer matrix. comput mater sci 2003 28: 743–8. 7. rothon rn. mineral fillers in thermoplastics filler manufacture and characterization. adv polym sci 1999; 139: 67–107. 8. hutchings im. tribology: friction and wear of engineering materials. london: crc press; 1992. 9. leszczyn´ska a, njuguna j, pielichowski k, banerjee jr. polymer/montmorillonite nanocomposites with improved thermal properties: part 2 thermal stability of montmorillonite nanocomposites based on different polymeric matrixes. thermochim acta 2007; 454: 1– 22 10. arksornnukit m, takahashi h, nishiyama n. effects of silane coupling agent amount on mechanical properties and hydrolytic durability of composite resin after hot water storage. dent mater j 2004; 23: 31-6. 11. hocker h. plasma treatment of textile fiber. pure appl chem 2002; 74(3): 423-7. 12. american dental association specification no. 57, 12 (1999) for denture base polymers. chicago. : council on dental materials and devices. ansi/ada. 13. craig rg, power jm. restorative dental material. 11th ed. st. louis: mosby; 2002. p.185-95. 14. sun l, ronald fg, suhr j, grodanine jf. energy absorption capability of nano composites: a review. composites science and technology 2009; 69: 2392409. 15. ellakwa ae, morsy ma, el-sheikh am. effect of aluminum oxide addition on the flexural strength and thermal diffusivity of heat-polymerized acrylic resin. j prosthodont 2008; 17: 439-444. 16. vallittu pk, ruyter , kstrand i. effect of water storage on the flexural properties of eglass and silica fibers acrylic resin composite. int. j prosthodont 1998; 11: 340-50. 17. jasim bs. the effect of silanized alumina nano -fillers addition on some physical and mechanical properties of heat cured polymethyl methacrylate denture base material. m.sc. thesis, college of dentistry, university of baghdad, 2013. 18. mohammed wi. the effect of addition of untreated and oxygen plasma treated polypropylene fiber on j bagh college dentistry vol. 27(3), september 2015 studying the effect restorative dentistry 27 some properties of heat cure acrylic resin. m.sc. thesis, college of dentistry, university of baghdad, 2013. 19. sato h, ogawa h. review on development of polypropylene manufacturing process. sumitomo kagaky (2009); 2: 1-11. 20. almomen mm. effect of reinforcement on strength and radiopacity of acrylic denture base material. m.sc. thesis, college of dentistry, university of baghdad, 2000. 21. marei mk, el-sabrooty a, ahmed y, ragab, elqsaairy ma. a study of some physical and mechanical praperties of metal filled acrylic resin. saudi dental j 1994; 6 (2): 69-77. 22. frank hr, phillip ds. enhanced boron nitride composition and polymer based high thermal conductivity molding compound; 2002: 794 227. الخالصة % 0,5(المعالج بالمادة الرابطة بتركیز al2o3الغرض من ھذه الدراسة لتقییم تأثیر إضافة خلیط مكون من الحبیبات النانویھ لمسحوق اوكسید االلمنیوم ة، وخشونة د، والصالمستعرضھعلى قوة الصدمة والقوة ال) بالوزن%2,5(وألیاف البولي بروبلین المعالجة ببالزما األوكسجین ) بالوزن%1و,وزنبال ة عین)30(ثم صنفت الى خمسة مجامیع وفقا لألختبارات التي اجریت كل مجموعة تتكون من) 150(حضرت مائة وخمسین عینة. ، وألتوصیل الحراريالسطح بالحبیبات النانویھ الوكسید (، والمجموعھ الثانیھ مدعمة)مجموعھ بدون أضافات ھي مجموعة السیطره(وھذه المجموعة قسمت الى ثالث مجامیع اخرى كاالتي الثھ المدعمھ بالحبیبات المجموعھ الث, )بالوزن%2,5بالوزن وألیاف البولي بروبلین المعالجة ببالزما األوكسجین بتركیز %0,5االلمنیوم المعالجھ بتركیز وكانت التجارب التي أجریت ھي قوة .بالوزن%2,5بالوزن والیاف البولي بروبلین المعالجھ ببالزما االوكسجین بتركیز %1النانویھ الوكسید االلمنیوم بتركیز (anova)تم تحلیل النتائج إحصائیا باستخدام اختبار . ،خشونة السطح، والتوصیل الحراري )shore d(ة السطح د، وصال مستعرضھالصدمة والقوة ال وكذلك ارتفاعا غیر ملحوظ للقوه وزیادة ملحوظھ في خشونة السطح لوحظ وجود زیادة ملحوظھ للغایة في قوة الصدمة وصالبة السطح والتوصیل الحراري . بالوزن من حبیبات اوكسید %1وعند التركیز .بالوزن من الیاف البولي بروبلین%2,5وكسید االلمنیوم وبالوزن من حبیبات ا%0,5بنسبة المستعرضھ بالوزن من الیاف البولي بروبلین ھناك ارتفاع ملحوظ للغایھ في قوة الصدمھوصالبة السطح والتوصیل الحراري وارتفاع غیر ملحوظ %2,5االلمنیوم النانویھ و أن إضافة خلیط من حبیبات أوكسید االلمنیوم النانویة المعالجة سطحیا والیاف البولي بروبلین المعالجھ .ملحوظ في خشونة السطح بالقوه المستعرضھ وارتفاع ة السطح والتوصیل الحراري لالكریلك الحراري الراتنجي و في نفس الوقت ھناك دببالزما االوكسجین لالكریلك الحراري الراتنجي یحسن قوة الصدمة وصال .في القوه المستعرضھ وزیادة في خشونة السطح یاده غیر ملحوظھ احصائیا ز an ideal substitute for missing j bagh college dentistry vol. 29(1), march 2017 dental anomalies in pedodontics, orthodontics and preventive dentistry 148 dental anomalies in permanent teeth and the associated etiological factors among fifteen years-old students in basrah city\iraq nadia azzam al-sheraydah b.d.s.(1) zainb al-dahan b.d.s., m.sc.(2) abstract background: dental anomalies of teeth are major issue that contributes to dental problems encountered in general practice. the aim of this study is to measure the prevalence of dental anomalies and the associated etiological factors among 15 years old students in basrah city –iraq. materials and methods: the total sample composed of 1000 students (435 males and 565 females) from urban area selected randomly from different high schools in the city. diagnosis of dental anomalies were recorded by present or absent, diagnosis and recording of enamel defects were done according to the criteria of who (1997). results: the prevalence of hypodontia was 4.6%, females have higher prevalence than males (5.8% females and 3.0% males), talon cusp prevalence was 37.0% (males 38.6% and females 35.8%), the prevalence of microdontia was 1.4% (males were equal to females 1.4%), the prevalence of supernumerary teeth, fusion, macrodontia and gemination was 0.8%, 0.7%, 0.1% and 0.1% respectively. the prevalence of enamel defects was 30.5%, demarcated opacities prevalence was 23.8%, it is the most prevalent type of enamel defects (males 20.5% and females 26.4%) followed by diffuse opacities 9.1% then enamel hypoplasia 0.4%. conclusion: this study revealed that secondary school students have dental anomalies, some of them with high prevalence, while other has very low prevalence. keywords: dental anomalies, etiological factors, basrah city. (j bagh coll dentistry 2017; 29(1):148-152) introduction dental anomalies of teeth are not uncommon problem, anomalies of teeth number, shape and structure occur due to abnormal events in the embryological development of teeth that may be resulted from environmental and genetic factors during the morphodifferentiation or histodifferentiation stages of tooth development (1). anomalies of teeth shape include: fusion that can be defined as joining of two developing teeth germs, resulting in a single large tooth structure (2). gemination defined as the attempt of tooth bud to divide, that will resulted in the formation of tooth with a bifid crown and common root with root canal (3). talon cusp is a well-defined accessory cusp project from the cingulum or cemento-enamel junction to the incisal ridge of the upper or lower anterior teeth in both the deciduous and permanent dentitions (4). microdontia defined as a tooth that is much smaller than normal average size while macrodontia defined as a tooth that is much larger than normal average size (5). anomalies of the number of teeth include: hypodontia and supernumerary teeth, hypodontia defined as congenital lack of teeth that results from (1) master student. department of pediodontic, college of dentistry, university of baghdad (2) professor, department of pediodontic, college of dentistry, university of baghdad. disturbances during tooth development in early stages (6). supernumerary teeth can be defined as extra teeth occurring in dental arch, more than twenty in deciduous dentition or more than thirty-two in the permanent dentition (3). enamel defects can be defined as any alteration that results from wide disturbances during the process of odontogenesis, these defects include diffuse opacities, demarcated opacities and enamel hypoplasia (7). the etiological factors for the development of dental anomalies that had been studied include tooth trauma, deciduous tooth extraction, previous surgery in the jaw, low birth weight and systemic diseases (8) (9). the aim of this study was to measure the prevalence of dental anomalies and find an association with the etiological factors. materials and methods this study was conducted among high school students during the period from the middle of november 2014 till the beginning of april 2015 in basrah city, iraq. in this study the sample consist of 1000 students aged 15 years old, the schools were randomly selected, and they were distributed in different geographical location in basrah city. j bagh college dentistry vol. 29(1), march 2017 dental anomalies in pedodontics, orthodontics and preventive dentistry 149 diagnosis of dental anomalies were recorded by present or absent, diagnosis and recording of enamel anomalies were done according to criteria of who 1997, questionnaire papers were distributed to the students to answer questions related to the etiological factors, these questions include if the students had exposed previously to tooth trauma, deciduous tooth extraction, previous surgery in the jaw and also were asked to try to locate the tooth or if they had low birth weight and any systemic disease . data entering and analysis was performed using spss version 21 computer software (statistical package for social science) in association with microsoft excel. the tests that were used in this study include: 1. t-test. 2. chi-square test. 3. odds ratio. results table (1) illustrates the distribution of the sample by gender, the sample consist of 435 males (43.5%) and 565 females (56.5%). table (2) demonstrates the total prevalence of the selected anomalies among the sample. the prevalence of talon cusp was 37.0 %, demarcated opacities was 23.8 %, diffused opacities was 9.1 %, hypodontia was 4.6 %, microdontia was 1.4 %, supernumerary teeth was 0.8 %, fusion was 0.7 %, enamel hypoplasia was 0.4 %, macrodontia was 0.1 %, gemination was 0.1 % and any type of enamel defect was 30.5 %. table (3) shows the relationship between tooth trauma and dental anomalies which was non significant statistically. table (4) illustrates the relationship between deciduous tooth extraction and dental anomalies by using chi-square test, the results were non significant statistically except the relationship between deciduous tooth extraction with demarcated opacities and any type of enamel defects which was significant statistically (p <0.001, p =0.022). table (5) shows the relationship between previous oral surgery and dental anomalies which was non-significant statistically. table (6) demonstrates that there is no significant relationship between low birth weight and dental anomalies. table (7) demonstrates that there is no significant relationship between systemic disease and dental anomalies. table 1: the distribution of the sample by gender gender n % males 435 43.5 females 565 56.5 total 1000 100.0 table 2: the prevalence of the selected anomalies among the sample anomalies (total n=1000) n % 95% confidence interval at least one tooth with talon cusp 370 37.0 (34%to40.1%) at least one tooth with demarcated opacity 238 23.8 (21.2%to26.6%) at least one tooth with diffuse opacity 91 9.1 (7.4%to11.1%) at least one tooth with hypodontia 46 4.6 (3.4%to6.1%) at least one tooth with microdontia 14 1.4 (0.8%to2.4%) at least one tooth with supernumerary 8 0.8 (0.4%to1.6%) at least one tooth with fusion 7 0.7 (0.3%to1.4%) at least one tooth with enamel hypoplasia 4 0.4 (0.1%to1.0%) at least one tooth with macrodontia 1 0.1 (0.003%to0.6%) at least one tooth with gemination 1 0.1 (0.003%to0.6%) at least one tooth with any type of enamel defect 305 30.5 (27.7%to33.5) pedodontics, orthodontics and preventive dentistry 150 table 3: the relationship between tooth trauma and dental anomalies tooth trauma negative (n=963) positive (n=37) anomalies n % n % p or 95% ci for or at least one tooth with hypodontia 44 4.6 2 5.4 0.69[ns] 1.19 (0.28 to 5.12) at least one tooth with microdontia 14 1.5 0 0.0 1[ns] ** ** at least one tooth with talon cusp 354 36.8 16 43.2 0.42[ns] 1.31 (0.68 to 2.54) at least one tooth with diffuse opacity 86 8.9 5 13.5 0.37[ns] 1.59 (0.61 to 4.2) at least one tooth with demarcated opacity 229 23.8 9 24.3 0.94[ns] 1.03 (0.48 to 2.22) at least one tooth with any type of enamel defect 291 30.2 14 37.8 0.36[ns] 1.41 (0.71 to 2.77) note: the (**) means cannot be calculated. table 4: the relationship between deciduous tooth extraction and dental anomalies tooth extraction negative (n=829) positive (n=171) anomalies n % n % p or 95% ci for or at least one tooth with hypodontia 37 4.5 9 5.3 0.65[ns] 1.19 (0.56 to 2.51) at least one tooth with microdontia 12 1.4 2 1.2 1[ns] 0.81 (0.18 to 3.63) at least one tooth with talon cusp 306 36.9 64 37.4 0.9[ns] 1.02 (0.73 to 1.44) at least one tooth with diffuse opacity 77 9.3 14 8.2 0.65[ns] 0.87 (0.48 to 1.58) at least one tooth with demarcated opacity 180 21.7 58 33.9 0.001 1.85 (1.29 to 2.64) at least one tooth with any type of enamel defect 240 29.0 65 38.0 0.022 1.5 (1.07 to 2.12) table 5: the relationship between previous oral surgery and dental anomalies oral surgery negative (n=992) positive (n=8) anomalies n % n % p or 95% ci for or at least one tooth with hypodontia 46 4.6 0 0.0 1[ns] ** ** at least one tooth with microdontia 13 1.3 1 12.5 0.11[ns] 10.76 (1.23 to 93.81) at least one tooth with talon cusp 366 36.9 4 50.0 0.48[ns] 1.71 (0.43 to 6.88) at least one tooth with diffuse opacity 89 9.0 2 25.0 0.16[ns] 3.38 (0.67 to 17.01) at least one tooth with demarcated opacity 234 23.6 4 50.0 0.1[ns] 3.24 (0.8 to 13.05) at least one tooth with any type of enamel defect 300 30.2 5 62.5 0.06[ns] 3.84 (0.91 to 16.19) note: the (**) means cannot be calculated. table 6: the relationship between low birth weight and dental anomalies lowbirth weight(10) (<2kg) negative (n=608) positive (n=17) anomalies n % n % p or 95% ci for or at least one tooth with hypodontia 35 5.8 0 0.0 0.62[ns] ** ** at least one tooth with microdontia 8 1.3 0 0.0 1[ns] ** ** at least one tooth with talon cusp 222 36.5 4 23.5 0.27[ns] 0.53 (0.17 to 1.66) at least one tooth with diffuse opacity 50 8.2 1 5.9 1[ns] 0.7 (0.09 to 5.37) at least one tooth with demarcated opacity 145 23.8 3 17.6 0.77[ns] 0.68 (0.19 to 2.41) at least one tooth with any type of enamel defect 179 29.4 4 23.5 0.79[ns] 0.74 (0.24 to 2.29) note: the (**) means cannot be calculated. pedodontics, orthodontics and preventive dentistry 151 table 7: the relationship between systemic diseases and dental anomalies systemic disease negative (n=974) positive (n=26) anomalies n % n % p or 95% ci for or at least one tooth with hypodontia 46 4.7 0 0.0 0.63[ns] ** ** at least one tooth with microdontia 13 1.3 1 3.8 0.31 [ns] 2.96 (0.37 to 23.49) at least one tooth with talon cusp 364 37.4 6 23.1 0.14 [ns] 0.5 (0.2 to 1.26) at least one tooth with diffuse opacity 89 9.1 2 7.7 1[ns] 0.83 (0.19 to 3.56) at least one tooth with demarcated opacity 230 23.6 8 30.8 0.4[ns] 1.44 (0.62 to 3.35) at least one tooth with any type of enamel defect 295 30.3 10 38.5 0.39[ns] 1.44 (0.65 to 3.21) note: the (**) means cannot be calculated. discussion this study was designed to investigate the prevalence of dental anomalies among high school students aged 15 years old and study their relationship to the possible etiological factors. the prevalence of hypodontia was 4.6% and this is lower than al-jourane(11) and chung et al (12). there was no statistically significant difference between hypodontia and the studied factors, in order to find an association between hypodontia and the studied factors a larger sample size should be taken or a follow up study about the patients that have the etiological factors to determine the presence of this anomaly. talon cusp prevalence was 37.0% and this is higher than danker et al(13) .this difference in the prevalence of talon cusp may be due to the fact that diagnosis of this dental anomaly in other study was based on radiographs solely without clinical examination and this might produce a false positive or negative diagnosis because talon cusps are easily discovered on radiograph as they present as v-shaped structure superimposed on the tooth but there is an exception to that which is a type 3 trace talon cusp that cannot be detected during radiographic examination (14). in this study the prevalence of supernumerary teeth was 0.8% and this is lower than thilander et al(15), it was difficult to study the relationship between supernumerary teeth and the studied factors due to the small number of this anomaly detected in the study and this may be attributed to the fact that most supernumerary teeth are impacted, asymptomatic and diagnosed incidentally during radiographic examinations, so panoramic radiograph is essential for detection of supernumerary teeth (16). in this study the prevalence of fusion was 0.7% and this is higher than al-ani (17) and this is may be due to larger sample size that had been taken in this study than other studies. in this study the prevalence of gemination was 0.1% and this is equal to the results of neville et al(18). the etiology of double teeth may be attributed to trauma, hereditary and environmental factors, the cause may be attributed to the force of physical pressure that are generated during growth resulted in contact between adjacent teeth germs and union before calcification (19). in this study the prevalence of macrodontia and microdontia was 0.1% and 1.4% respectively, macrodontia and microdontia may be due to complex multifactorial interactions that include genetic and environmental factors occur during the long process of dental development (20). the prevalence of enamel defects was 30.5% and this finding was lower than (21) demarcated opacities which appear the most prevalent type of enamel defect 23.8% (males 20.5% and females 26.4%) followed by diffuse opacities 9.1% then by enamel hypoplasia 0.4%. there was no statistically significant relationship between enamel defects and the studied factors but there was significant relationship between tooth extraction, enamel defects and demarcated opacities, this is may be due to trauma that result from tooth extraction and cause disturbance in the process of matrix degradation which occur during matrix formation stage to provide suitable condition for the commencement of maturation (22). references 1. elizabeth a. multiple dental anomalies in young patients: a case report. int. j of paedia. dent. 2000; 10:63-66. pedodontics, orthodontics and preventive dentistry 152 2. velasco lf, de araujo fb, ferreira es, velasco le. esthetic and functional treatment of a fused permanent tooth: a case report. quintessence int 1997; 28: 677-680. 3. neville bw, damm dd, allen cm, bouquot je. oral and maxillofacial pathology, 2nd ed. saunders, elsevier 2002. 4. gündüz k, celenk p, zengin z, sümer p. mesiodens: a radiographic study in children. j oral sci. 2008; 50:287-91. 5. d ҆ souza rn, kapadia h, vieira ar, et al. human malformations and related anomalies. new york: oxford university press 2006. 446 p. 6. butler pm: ontogenetic aspects of dental evolution. int j dev biol; 1995, 39:25-34. 7. wong hm, mcgrath c, king nm. dental practitioners' views on the need to treat developmental defects of enamel. community dent oral epidemiol. 2007; 35: 130-139. 8. nunn jh, carter ne, gillgrass tj, hobson rs, jepson nj, meechan jg, et al. the interdisciplinary management of hypodontia: background and role of paediatric dentistry. br dent j 2003; 194:245-51. 9. seow wk. a study of the development of the permanent dentition in very low birthweight children. pediatr dent. 1996; 18: 379-384. 10. seow wk. a study of the development of the permanent dentition in very low birth weight children. pediatr dent. 1996; 18: 379-384. 11. aljourane ts. hypodontia of permanent teeth in a sample of student in baghdad city. a master thesis, college of dentistry, university of baghdad 2001.19:26. 12. chung cj, han jh, kim kh: the pattern and prevalence of hypodontia in koreans. oral dis 2008; 14:620-5. 13. danker e, harari d, rotstein i. dens evaginatus of anterior teeth. literature review and radiographic survey of 15,000 teeth. oral surg oral med oral pathol oral radiol endod. 1996; 81:472-5. 14. abed al-hadi, m hamasha and rima a safadi. prevalence of talon cusps in jordanian permenant teeth: a radiographic study. bmc oral health, 2010. 15. thilander b, pena l, infante c, parada ss, de mayorga c. prevalence of malocclusion and orthodontic treatment need in children and adolescents in bogota, colombia. an epidemiological study related to different stages of dental development. eur j orthod 2001; 23(2): 153167. 16. gábris k, fábián g, kaán m, rózsa n, tarján i. prevalence of hypodontia and hyperdontia in paedodontic and orthodontic patients in budapest. community dent health. 2006; 23:80–2. 17. al-ani n. oral health status, treatment needs and dental anomalies in relation to nutritional status among 12 years old school children in heet city\alanbar governorate\iraq. a master thesis, college of dentistry, university of baghdad, 2013. 18. neville bw, damm d, allen c, bouquot j. 2nd ed. new delhi: elsevier; 2004. oral and maxillofacial pathology; p. 78. 19. kjaer i. daugaard-jensen j. interrelation between fusions in the primary dentition and agencies in the succedaneous permanent dentition seen from an embryological point of view. j craniofac genet dev biol 2000, 20: 193-97. 20. brook ah (2009) multilevel complex interactions between genetic, epigenetic and environmental factors in the aetiology of anomalies of dental development. arch oral biol 54 suppl 1: s3-17. 21. al-nori a, al-talabani n. developmental anomalies of teeth and oral soft tissue among 14-15 years school children in baghdad city with refer to enamel defects. jorden .dent.j.1993, 8:5-14. 22. suga s. enamel hypomineralization viewed from the pattern of progressive mineralization of human and monkey developing enamel. adv dent res. 1989; 3: 188-198. الخالصة الهدف من هذه .تواجه خالل الممارسة العامة ان االشكال الشاذة التي تصیب االسنان تعتبر قضیة رئیسیة تساهم في حدوث مشاكل في األسنان والتي :الخلفیة .العراق-البصرة محافظة في سنة ١۵ في عمر الطالب بینهو معرفه نسبه انتشار االشكال الشاذة لألسنان وعالقتها بالعوامل المسببة لها الدراسة من عشوائیا العینة اختیرت وقدجمعت العینات من المناطق الحضرية )من اإلناث ۵٦۵من الذكور و ٤۵۵) طالب ١١١١ة من الكلی العینة تكونت :والطرق المواد . تم تسجیل التشخیص في شذوذ األسنان من خالل وجود أو عدم وجود هذه االشكال الشاذة, تم التشخیص وتسجیل محافظة البصرة في المختلفة الثانوية المدارس (.١٩٩١تشوهات المیناء وفقا لمعايیر منظمة الصحة العالمیة ) في ٪ ۵ ,في االناث و . ٪۸,١۵وان معدل االنتشار في االناث أعلى من الذكور ) ,٪ ٦,٤ان هذه الدراسة بینت ان انتشار نقص األسنان الدائمیة كان بنسبة :النتائج ١ ,٤كانت نسبه انتشار صغر حجم االسنان ان ),٪ ٦,۵۸ وفي الذكور ٪ ۸,۵۵اإلناث ) كانت النسبه في ٪ ۵١ان انتشار تالون أعتاب كان بنسبه , )الذكور ١,١ ,٪ ١,١ ,٪۸,١ضخامة األسنان وتضاعف االسنان كان ,االنصهار ,كما ان معدل انتشاراالسنان الزائده ,(١ ,٤)كانت النسبه في الذكور ذاتها في االناث لقد كانت العتمه البیضاء هي ,٪ ۸,۳۵ان نسبه انتشار العتمه البیضاء ,٪ ۵,۵١ء لقد اظهرت الدراسه ان معدل انتشار تشوهات المینا .بالتتابع ٪ ١,١ و ٪ نقص تصنع المیناء بنسبه تلیها ٪ ١,٩بنسبه العتمة المنتشرة ( تلیها٪٤,۳٦بینما في االناث ٪ ۵,۳١النوع االكثر انتشارا في تشوهات المیناء )نسبتها في الذكور ٤,١ ٪. في حین ان بعض ,وان بعض هذه الحاالت منتشرة بصوره واسعه ,ذه الدراسة أن الطالب في المدارس الثانوية لديهم شذوذ في األسناناظهرت ه :الخاتمة الحاالت الشاذة االخرى منتشرة بصورة منخفضة جدا. .البصرة مدينه ,العوامل المسببة ,االسنان شذوذ :الدلیلیة الكلمات 4 http://www.ncbi.nlm.nih.gov/pubmed/17331154 http://www.ncbi.nlm.nih.gov/pubmed/17331154 http://www.ncbi.nlm.nih.gov/pubmed/17331154 http://www.ncbi.nlm.nih.gov/pubmed/17331154 http://www.ncbi.nlm.nih.gov/pubmed/8897530 http://www.ncbi.nlm.nih.gov/pubmed/8897530 http://www.ncbi.nlm.nih.gov/pubmed/8897530 http://www.ncbi.nlm.nih.gov/pubmed/8897530 http://www.ncbi.nlm.nih.gov/pubmed/8897530 http://www.ncbi.nlm.nih.gov/pubmed/8897530 http://www.ncbi.nlm.nih.gov/pubmed/2640430 http://www.ncbi.nlm.nih.gov/pubmed/2640430 http://www.ncbi.nlm.nih.gov/pubmed/2640430 http://www.ncbi.nlm.nih.gov/pubmed/2640430 journal of baghdad college of dentistry, vol. 35, no. 1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 58 review article different methods of canine retractionpart 2 mohammed nahidh 1*, yassir a. yassir 2, grant t. mcintyre 3 1 ph.d. student, department of orthodontics, college of dentistry, university of baghdad, baghdad, iraq 2 assistant professor, department of orthodontics, college of dentistry, university of baghdad, baghdad, iraq. bab-almoadham, p.o. box 1417, baghdad, iraq. 3 honorary professor of orthodontics. school of dentistry, university of dundee, uk. * correspondence email: m_nahidh79@codental.uobaghdad.edu.iq abstract: background: this review aims to discuss various canine retraction techniques using frictionless mechanics. methods: between 1930 and february 2022, searches were conducted about various canine retraction techniques using fixed orthodontic appliances in various databases, including pubmed central, science direct, wiley online library, the cochrane library, textbooks, google scholar, research gate, and manual searching. results: after removing the duplicate articles, publications that described how to use archwires to perform canine retraction with the archwires were included. conclusions: the pros and cons of various canine retraction techniques using archwires were thoroughly discussed. t-loop is the preferred spring of all because of its characteristics. keywords: canine, retraction, fixed appliance, frictionless technique. introduction separate cuspid retraction is indicated in the cases of anterior teeth crowding, high canines, and midline discrepancy. alignment using continuous archwire may lead to incisor proclination that may cause labial bone defect, so separate canine retraction with frictionless mechanics is preferred over the continuous archwire technique to lessen these side effects (1). this review comprehensively describes all developed canine retraction methods using frictionless mechanics. canine retraction with the archwire (frictionless technique) in frictionless mechanics, a canine is moved individually with loops like "a train car being picked up and moved by a crane" (2). advantages 1. more esthetic since incisors bonding is often not essential (3). 2. alignment of incisors can happen rapidly, simultaneous with canine retraction (3). 3. there is no binding and friction, so there is no loss of applied forces (4). 4. the retraction mechanics is predictable as the number of forces and moments are quantifiable (1). 5. adequate' rebound time' for uprighting and arch leveling (2). disadvantages 1. it requires significant chair-side time (1). 2. loops are uncomfortable for the patient and may cause hygiene problems (2). received date: 18-02-2022 accepted date: 01-03-2022 published date: 15-03-2023 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/li censes/by/4.0/). https://doi.org/10.26477/ jbcd.v35i1.3314 https://orcid.org/0000-0003-0155-418x https://orcid.org/0000-0001-9577-8947 https://orcid.org/0000-0002-7224-4739 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3314 https://doi.org/10.26477/jbcd.v35i1.3314 j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 59 3. transverse control of the canines during retraction is reduced compared with sliding mechanics (1). 4. controlled root movement may not be easily accomplished as the loop incorporates more wire, decreasing the overall flexural rigidity (3). 5. anchorage reinforcement is required (3). 6. non-preferable rotation in the sagittal and transverse plane results from wrong mechanics will increase aligning stage (4). methods of canine retraction with the archwire canines are distalized using three primary methods: (1) full archwire without bonding the incisors (2) full archwire with bonding to the incisors (3) sectional arches: a) bull loop b) burstone cuspid retraction spring c) ricketts retraction spring d) burstone t-loop attraction spring e) reverse closing loop (helical loop) f) pg retraction spring g) hybrid retraction spring h) mushroom loop i) remaloy cuspid retraction spring j) nitanal spring k) wave spring l) marcotte spring m) modified marcotte spring n) three-dimensional canine loop o) simultaneous torquing, aligning, and retraction (s-tar) spring p) retraction loop (r-loop) (1) full archwire without bonding the incisors in this method, a continuous archwire with two loops on each side retracts the canines without bonding the incisors (5). the anterior loop is pear-shaped, in contact with the mesial surface of the canine brackets, and opened on activation. the posterior (distal) loop is a reverse u-loop (closing loop) located 2 mm behind the canine bracket, activated by closing the loop to approximate the two arms of the loop. the anterior section of the archwire is contoured to come in light contact with the incisors left without brackets. the activation of this design is performed by pulling the archwire through the molar tube and turning it down (up according to the arch) so as the anterior (mesial loop) will be opened about 1mm and the posterior (distal) loop will be closed by the same amount. in some occasions, light intraor inter-maxillary elastics may be used to exert a light force of 50-60 grams, hooked to the anterior loop so that it will pull the anterior section of the archwire resulting in compressing the anterior loop; thus, the canine is retracted by the pushing action of the anterior loop and the pulling action of the posterior loop. an archwire of 0.016 and 0.018inches is supposed to be suitable for tipping the canine distally (figure 1). j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 60 figure 1: canine retraction using full archwire without bonding the lower incisors advantages 1. canine control in the transverse plane is best done with a full archwire. 2. the incisors will be aligned spontaneously because they are left without an archwire. disadvantages 1. such a design needs an experienced orthodontist in wire bending as the distance between the canine brackets should be determined accurately to get correctly positioned mesial loops. 2. in some circumstances of over-activation by the loops and elastics, the incisors may be retroclined from the pressure of the archwire. 3. irritation of the lips may occur as the archwire is not ligated to the incisors' brackets, and to solve this problem, a plastic tube or sleeve is used to protect the lip and the archwire from deformation. 4. a limited number of activations can be performed with this design before the heavy contact of the archwire with the incisors. (2) full arch with the bonding of the incisors in this technique, the incisors will be bonded either for anchorage purposes or for aligning purposes (5): (a) incisors bonded for anchorage here, the same design of wire bending discussed in the previous section is used except for including the incisors by bending the archwires to lie passively in their brackets. this technique is not indicated in severely crowded or imbricated incisors because ligating them with an archwire is challenging. advantage 1. more comfortable for the patient as there is no chance of distortion for the anterior section of the archwire or trauma. disadvantages 1. some forward movement of the anterior teeth is anticipated when activating this design, although the distal movement of the canines will counteract it. 2. incisor alignment may not occur spontaneously as in the previous method. (b) incisors bonded to permit their alignment during canine retraction j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 61 a flexible round archwire of 0.014, 0.016, or 0.020-inch stainless steel is used according to the bracket slot size to bend the vertical multi-looped design between each incisor. moreover, two vertical loops mesial and 2mm distal to the brackets of the canines, just like the previous design, are bent too. in some cases, the distal loop can be omitted, and the wire left plain distal to the canine brackets, provided that the force exerted by the intra-maxillary elastics attached to the canine brackets will augment the distal movement of the canines. before ligating the archwire to the anterior teeth, all the anterior loops must be opened in a very small amount, then the arch is tied in, and activation is performed by pulling the ends of the wire through the molar tubes and turning them down (figure 2). figure 2: canine retraction using full archwire with bonding the incisors for their alignment advantage 1. prompt alignment of all the teeth can be attained at the early stages of treatment. disadvantages 1. proclination of the incisors can happen mostly with substantial crowding in the area of incisors, yet the counteraction effect of the intra-maxillary elastics, which results in closing the anterior loops, may retrocline the incisors providing adequate space is available. 2. the method requires more chair time and sound manipulation in wire bending as the inter-bracket distance is short. 3. this design is traumatic to the lips and gingivae. 4. this technique must be used cautiously in severe crowding, or anchorage control is critical. 5. binding of the archwire may be occurred upon using intra-maxillary traction elastics, preventing the free sliding of the wire through the second premolar brackets and molar tubes, leading to proclination of the whole labial segment. (3) sectional arch a section of the archwire extends from the first molar to the canine bracket without passing the anterior teeth. it consists of a vertical loop located distal to the canine bracket with different designs activated by pulling up the wire through the molar tube and cinching back. it has been shown that the activation of the sectional arch is better done by closing rather than opening the loop because the resistance of the wire to deformation will be increased as the wire is deformed in the original direction of bending. it can be made from a round flexible or rigid rectangular archwire. the complex design of the sectional arch will include more wire length that makes the loop more flexible and produces constant force over a longer distance. this design is preferred to retract mesially angulated canines by tipping, while a less flexible loop is desirable to retract a distally angulated canine that needs more movement control. unlike the sectional arch constructed from rectangular wire, the one constructed from round wire may rotate around the bracket, so a stop must be incorporated mesial to the canine bracket to form two points of contact to prevent that rotation. j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 62 the anchorage issue is essential to control by ligating the second premolar with the first molar, using the nance button, trans-palatal arch, and lingual arch, incorporating tie-back loop or v-bend just distal to the second premolar bracket to permit frequent reactivations. anti-tip and anti-rotation bends must be incorporated into the sectional arch to prevent the tipping and rotation of the canine during retraction (5). advantages 1. patients prefer a sectional arch as no wire will cross the incisors (esthetic). 2. automatic alignment of the anterior teeth (while remaining within the muscle balance zone) can be anticipated in many cases as the canine is retracted in the extraction space. 3. quick and easy reactivation. 4. a round sectional wire is easy to fabricate. disadvantages 1. trauma to the patient can be caused by the loop being buried in the mucosa or sticking out into the cheek, especially with round sectional wire, as it may rotate in the bracket. 2. the movement of the canine is tricky to control with a round wire. 3. severe distal tipping may have occurred if the orthodontist inadvertently did not counteract that with proper wire bending or used round sectional wire. 4. if constructed from a round wire, substantial buccal movement of the canines may occur if it does not lie passively in the canine bracket in the buccolingual plane. sixteen different types of sectional arches have been used in canine retraction: (a) bull loop this spring was introduced by dr. harry bull and took its name from the founder. it is made of 0.021×0.025 inch stainless steel wire with closed-loop (two closely approximating vertical arms) situated mid-way in the space of extracted first premolar and two legs (mesial and distal). the distal one contains a small tie-back loop forward to the second molar tube (figure 3). the activation entails bending the mesial leg gingivally about 45º-60º to engage the mesial surface of the canine's bracket and pulling the distal end behind the last molar tube and bending it down so open the closed-loop not more than 1mm, leading to canine retraction bodily (6,7). figure 3: canine retraction using bull spring (b) burstone cuspid retraction spring burstone (8) developed a cuspid sectional retraction spring by combining heavy and light wires to get maximum control. the distal force delivered to retract the canine was gained from an anterior segment fabricated of a light 0.008×0.020 inch 18-8 stainless steel wire. the other part of the spring, called also the base or depression segment fabricated of 0.015×0.028 inch steel wire (figure 4). up on activation, the spring delivered distal force and couples that prevent canine rotation, also maintaining the center of rotation at the apex. the force and moments tend to tip back the posterior segments and elevate them by a gingival bend incorporated within the depression segment. j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 63 as usually done in segmented arch mechanics, anchorage must be well prepared using a heavy 0.0215×0.028 inch archwire segment to stabilize the buccal segments and the trans-palatal arch. using this spring, cuspid retraction was performed within twelve weeks with a maximum force magnitude of approximately 175 gm. figure 4: burstone cuspid retraction spring (c) ricketts retraction spring ricketts and his associates (9) developed two types of retraction springs, one for retracting maxillary canines, called double vertical crossed t closing loop, and the other for the lower canine and called double vertical helical closing loop (figure 5). they are fabricated from 0.016×0.016 blue elgiloy and activated 2-3 mm by pulling the wire behind the first molar tube and cinching back to give about 50 gm for the maxillary spring and 75 gm for the mandibular one. anchorage is controlled using the nance appliance in the maxillary and lingual arch or the utility arch in the lower arch. elastic thread can be used from the lingual side to control the rotation of the canine during retraction. figure 5: ricketts cuspid retraction springs (d) burstone t-loop attraction spring this type of retraction loop was introduced and developed by dr. burstone in 1982. it is designed for canine retraction in the segmented arch technique. it is fabricated from 0.017×0.025 inch beta-titanium archwire. it consists of a horizontal loop of 10 mm in length and 2 mm high, a mesial leg of 5 mm in height, and a distal leg of 4 mm in height positioned equidistant between the molar band and the bracket of the canine (figure 6). t-loop is activated horizontally by 4 mm with six pre-activation points, each of 30º, making a total of 180º activation. in order to prevent the rotational tendency of the canine, anti-rotation bends of 120º are performed in the mesial leg of the loop (10). j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 64 figure 6: burstone t-loop spring advantages unlike the vertical loops, it is designed to make the moment-to-force ratio more constant, which can be achieved by decreasing the load-deflection rate and using the t loop design, which increases the activation moment by placing wire more apically. bourauel et al. (11) modified the original t-spring of burstone by developing the superelastic t-loop for a canine or en-masse retraction. it consisted of a niti t-segment and stainless steel arms connected via crimpable hooks to the niti segment. (e) reverse closing loop (closed helical vertical loop) this loop was developed by ulgen (12) and used by dinger and işcan (13) to retract the maxillary and mandibular canines. it consists of two vertical arms 2mm apart, a helix (to increase the flexibility of the wire and decrease the force produced), and a tie-back small loop just distal to the second premolar bracket (figure 7). activation is performed by tightening a steel ligature wire between the tie-back and the hook of the molar band so that when it is pulled tight, the arms of the loop come in contact. figure 7: reverse closing loop (f) pg retraction spring poul gjessing introduced this type of spring in 1985. it is fabricated from 0.016×0.022-inch stainless steel wire and designed for controlled retraction of canines and maxillary incisors. the main active wire component is the ovoid double helix loop that extends 10 mm apically to decrease the load/deflection of the spring. moreover, it is placed gingivally so that the activation will cause tipping of the short horizontal arm (attached to the canine) in a direction that will increase the couple acting on the tooth. the other part is a small loop located occlusal to close the loop on activation, while the third part is the mesial and distal extensions of the looped wire segment, which are angulated vertically and horizontally (figure 8). the spring activation is performed by pulling the distal leg through the molar tube and turning it so that the two sections of the double helix are separated by 1 mm. this will give approximately 140-160 gm of j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 65 force. the activation is repeated every four weeks, and the expected controlled canine movement is approximately 1.5 mm per activation (14). advantage 1. it produces more rapid retraction with less tipping of the canines. disadvantages 1. it is a bulky spring. 2. the variations in the depth of the buccal sulcus may limit the loop's height. figure 8: pg retraction spring (g) hybrid retraction spring this type of retraction means called so since various materials are used in construction. it consists of an encapsulated superelastic compression spring (force-producing part), a protective tube of 2.2 mm in diameter, a spacer, a superelastic piece of 0.018×0.018 wire (inserted at an angle in the vertical slot of the canine bracket from one side and the protective tube from the other side) and a piece of 0.017×0.025 inch rectangular stainless steel wire inserted into the auxiliary tube of the molar band (figure 9). before insertion in the slot, the superelastic piece is twisted about 45° to produce the anti-rotational moment. to ensure canine retraction along the alveolar process, a bend with 10 to 15° is introduced, and a further compensatory bend in accordance with the course of the dental arch is added to the steel portion to ensure that the canine is not moved buccally. the activation range of this spring is 5 mm (15). advantages 1. in comparison with other springs, actual bodily canine retraction can be performed. 2. the steel portion of the wire allows the introduction of second and third-order bends. 3. it can be used for en-masse retraction of incisors. disadvantages 1. a custom bracket with a vertical slot is required. figure 9: hybrid retraction spring j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 66 (h) mushroom loop from its name, it looks like a mushroom and is similar to the t-loop but with a curved apical area. it is used for individual canine retraction and en-masse retraction of all anterior teeth in a continuous archwire incorporating sufficient torque (figure 11). it can be fabricated from 0.017×0.025 inch bettitanium archwire, yet 0.016×0.022 inch may be of choice for adults needing low force to move their teeth (16). advantages 1. due to the archival configuration in the apical part of that spring, the force produced will be low and continuous while the generated moment will be increased on activation. this will increase the m/f ratio and allow greater root and anchorage control. 2. the force delivery is more constant as the loop is fabricated from a beta-titanium archwire with a much lower stiffness than stainless steel. figure 11: mushroom loop (i) remaloy cuspid retraction spring it is a type of ready-made sectional archwire for canine retraction developed by ladanyi (17) and made from 0.016×0.022 inch blue elgiloy wire to modify the closed helical vertical loop. it is activated by introducing anti-tip, and anti-rotation bends, gently pulling distal to the molar tube, and bending down, so the two legs approximate each other (figure 12). advantages 1. it delivers a light force of about 90 gm/mm per activation. 2. it is gentle and long-acting as it contains a loading spring. 3. it can produce canine bodily retraction. figure 12: remaloy cuspid retraction spring j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 67 (j) nitanal spring watanabe and miyamoto (18) developed a canine retraction spring of 0.016×0.022 inch nickel-titanium wire. it consists of a simple vertical closing loop with anti-tip, and anti-rotation bends placed using three-prong pliers. it is then embedded in a heat-resistant plaster to maintain its shape for 15 minutes at 550°c (figure 13). advantages 1. it can deliver continuous forces and moments over a wide range of activation. 2. it can retract the canines and level the posterior teeth concurrently. 3. it provides a continuous light force. 4. it can be activated as much as 10 mm; hence canine retraction can be achieved with only one activation, decreasing patient discomfort, chair time, and the frequency of appointments. figure 13: nitanal spring (k) wave spring it looks like a wave when extended (figure 14). it is fabricated from superelastic nickel-titanium alloy and has a 6mm length in resting state. it can deliver a comparatively large activation force, reaching 90 grams. this spring can return to its original shape without deformation even after activation to more than three times its resting length (18). figure 14: wave spring in resting and activation states advantages 1. unlike the closed coil spring, the spring is stretched linearly during activation, and when it returns to its resting position, it will not produce unwinding torque. 2. it is hygienic and comfortable as it does not contain coils, so it will not protrude into the buccal vestibule. 3. eyelets are integrated into the original design, eliminating the eyelets from loosening or falling off. 4. the spring can be doubled up without becoming bulky if more force is required. j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 68 (l) marcotte spring michael marcotte developed this spring in 1990 (20). it is fabricated from 0.016-inch stainless steel wire with a single closing vertical loop of 6 mm length and 2mm width. it extends from the auxiliary tube of the first molar tube to the canine bracket and can be activated by pulling the wire exit through the auxiliary tube and cinched back gingivally. advantages 1. the design of the spring is straightforward. 2. it can be fabricated at the chair side. disadvantages 1. the wire is small in diameter that is liable to deformation. 2. trauma to the soft tissue due to impingement may occur. 3. loss of torque and rotational control, so it is used for minor canine retraction (about 1-2 mm). (m) modified marcotte spring this spring consists of a 6–8 mm height and 3 mm width closing loop, with the distance between the two arms being about 2 mm (figure 15). it looks like the original marcotte spring but fabricated from 0.017 × 0.025 inch tma archwire to provide a superior fit in the auxiliary molar tube, with an internal dimension of 0.018 × 0.025 inches (21). before activation, just like the marcotte spring, an anti-rotational bend of about 10°–15° is placed on the mesial arm in addition to a mesial tip of 15°–20°. an anti-extrusion bend of 20°–30° is placed on the distal arm to prevent extrusion. advantages 1. the design of the spring is straightforward. 2. it can be fabricated at the chair side. 3. offers better rotational and directional control. figure 15: modified marcotte spring (n) three-dimensional canine loop mehrotra et al. (22) developed a three-dimensional loop (3d loop) for treating ectopically erupted canine using sectional tma 0.017× 0.025 inch archwire. it consists of a closing loop with a 6 mm length mesial vertical arm and a 13 mm in length distal vertical arm with a 2mm distance between them. the distal vertical arm is longer than the mesial one to facilitate canine extrusion and can be adjusted with regard to the need for extrusion by bending it 90º to form the active arm that will engage the slot of the palatally bonded bracket. usually, this distal vertical arm is bent toward the tissue surface for ease of placement (figure 16). j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 69 anchorage is maintained using the trans-palatal arch. to activate this loop, the active arm is bent 15º to give palatal root torque to maintain the canine root in the cancellous bone, avoiding the cortical anchorage and the chance of dehiscence throughout the treatment. a mesial up or down 15º bend can be added to the active arm to correct the canine angulation. the distal extension of the mesial arm will be inserted into the auxiliary tube of the molar band. figure 16: three-dimensional canine loop advantages 1. the canine will be moved in three space planes (tip, torque, and extrusion). 2. the patient feels less discomfort because the attachment will be bonded on the palatal surface of the malposed canine, so the possibility of mucosal ulceration of lips and cheeks will be less. (o) simultaneous torquing, aligning, and retraction (s-tar) spring jain et al. (23) developed s-tar spring to control the torque and extrusion during canine retraction into the extraction space. it extends from the auxiliary tube of the molar band to the canine (figure 17). it is fabricated from 0.017×0.025 inch tma archwire. it consists of a closing loop of 9 mm height with a 2mm distance between the legs (to aid in retraction), a v-bend located distal to the canine (to aid in localizing the torque to the anterior segment of the spring), and a box anterior to the v-bend with 3-4mm height (to aid in maintaining the torque and tip during the retraction of the canine). activation is performed by pulling the wire distal to the molar tube so that the legs of the vertical loops come in contact and then bent back in addition to the pre-activation lingual root torque anterior to the v-bend by about 15º. advantages 1. it is easy to fabricate and activate on the chair side. 2. it provides control during canine retraction in all three planes of space. disadvantage 1. soft tissue trauma might occur depending on the height of the buccal vestibule. figure 17: s-tar spring j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 70 (p) retraction loop (r-loop) this loop type is fabricated from 0.017×0.025 inch tma archwire and designed to correct the ectopic labially positioned canine (figure 18). it extends directly from the molar tube to the canine bracket or may pass through the second premolar bracket (24). the vertical loop can be added to increase the flexibility of the spring. advantages 1. it is simple to fabricate and takes less chair time. 2. it prevents the canine's root tip from overriding the incisors. 3. retracting ectopic canine by this spring will preserve the attached gingiva and the periodontal health of the tooth. figure 18: r-loop miscellaneous methods of canine retraction (1) sectional stainless steel archwire with elastomeric chain a piece of heavy gauge rectangular archwire extended directly from the canine bracket to the molar tube, engaging these teeth passively and ending with a stop mesial to the canine bracket. a hook (maybe soldered) or crimpable hook may be crimped directly to the archwire about 3 mm distal to the canine bracket to act as a point of force application for attaching an elastomeric chain to retract the canine by sliding (5). advantages 1. the chance of wire binding is meager as the archwire is extended from the canine bracket to the molar tube, so the sliding will be easy. 2. this technique can be used even if the second premolar is not erupting. 3. more comfortable and esthetic to the patient as fewer teeth are bonded. 4. quick technique as it does not require extensive wire bending (just the stop) and takes less chair time. disadvantages 1. the anchorage issue is the main disadvantage of this method as if the archwire incorporated anchorage bend; it will cause excessive friction in the molar tube, moreover; incorporating the second premolar cannot be done. the nance button will provide good anchorage in anteriorposterior and transverse dimensions with or without a trans-palatal arch. 2. this technique can be applied only if the canine and molar are upright and aligned in the arch. (2) sectional nickel-titanium archwire with elastomeric chain j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 71 this technique uses a straight section of 0.017×0.025 inch nitinol archwire with some first-order bends performed using triple-beaked pliers without needing the third-order bends. after three weeks of the first premolar extraction, this wire is bent to pass passively through the canine and second premolar slots directly to the first molar band tube. it is indicated in cases of class i relationships and never be used in the maxilla in other cases. the design of this wire involves introducing three bends; the first one is located distal to the second premolar to like as the offset for the first molar, providing vertical flexibility. the second bend is located mesial to the second premolar in a verbal direction to prevent buccal movement of the canine, while the third is a lingual curve mesial to the bracket of the canine to minimize the trauma to the patient (figure 19). light intra-arch elastic (elastomeric power chain) retracts the canine part bodily and part tipping (25). the anchorage can be gained from the headgear in the maxillary arch and banding the second molar in the lower arch. nance button with or without the trans-palatal arch in the upper jaw and lingual arch in the lower jaw may provide satisfactory anchorage. figure 19: sectional nickel-titanium archwire with elastomeric chain advantages 1. compared with other sectional techniques, soft tissue trauma is very minimal. 2. patients can accept such a design because it is easy to clean. 3. the construction, fitting, activation, and follow-up reactivation are simple and take less chair time. 4. the vertical distortion of the wire in the extraction site is little or absent. 5. movement of the canine root distally can be achieved with a simple technique without causing an iatrogenic deep bite. 6. many clinicians with different experience levels found it very effective and rapid in managing different clinical situations without time wasted in the alignment stage. (3) drum spring retractor the drum retractor is designed by darendeliler et al. (26) for individual canine retraction with one activation using constant light force (50 gm) without an archwire. it consists of four parts: a constant force spring with a hook principally designed and fabricated to apply 50 gm force, a drum, a spring box, and a central pin soldered to the molar band (figure 20). activation is performed by pulling the end of the spring. figure 20: drum spring retractor j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 72 advantages 1. it can apply constant and continuous force. 2. no archwire is used with this spring. 3. it needs just one activation to close the extraction space. 4. precise analysis of the force applied to move the canine can be performed. 5. comfortable to the patient as soft tissue trauma or irritation is minimal because the point of force application is 6 mm. apical to the canine bracket slot, which leads to less tipping at the same time. disadvantage 1. uncontrolled canine rotation is predicted with the absence of the guiding archwire. (4) canine retraction with rare earth magnets daskalogiannakis and mclachlan (27) utilized the magnet forces in retracting canines by exerting a prolonged constant force that produces effective tooth movement. they used a special retraction assembly consisting of a vertical loop of 0.017×0.025 inch tma wire, vestibular wire of 0.018×0.025 inch stainless steel wire that is inserted in the auxiliary tube of the molar band, and three parylene coated neodymium-iron-boron (nd2fe14p) block magnets of 2×3×5 mm in size. the vestibular wire houses two magnets, the mesial and the distal, whereas the sectional wire of the vertical loop contains a helix between the second premolar and first molar that receives a middle magnet. the mesial and middle magnets were in repelling mode, whereas the distal and middle were in attractive mode. this will deliver constant force that activates the loop throughout canine retraction (figure 21). figure 21: canine retraction with rare earth magnets advantage 1. no reactivation of the loop is required. disadvantages 1. complicated design that may irritate the cheek. 2. it needs special care and management by an expert clinician. (5) distraction of periodontal ligament liou and huang (28) utilized the concept of distraction osteogenesis to develop a method of rapid canine retraction called dental distraction using custom made intra-oral distraction device (containing one distraction screw, two guidance bars, and a special apparatus to activate the distractor by turning the screw clockwise) and three bone cuts. j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 73 bands of 0.06×1.80 inch are seated on the canines, and the first molars and an impression are taken with the bands in place. in the lab., the distractor is soldered to the bands of the canine and first molar on the dental cast. the location and angulation of the distractor are adjusted according to the position of the canine. the distractor is usually positioned as high as possible to reduce tipping (figure 22). the procedure of canine retraction entails extraction of the first premolar and undermining the interseptal bone distal to the canine by grooving two vertical cuts along the buccal and lingual sides with an oblique one toward the base of the inter-septal bone (in order to abate its resistance) using bone bur. the depth of these undermining grooves is determined by evaluating the thickness of the inter-septal bone using periapical x-ray film . then a tooth-borne, custom-made device is placed to retract the canines into the extraction space. the authors assumed a similarity between the process of osteogenesis in the periodontal ligament during orthodontic tooth movement and the distraction in the mid-palatine suture during rapid palatal expansion. figure 22: canine retraction using distractor of periodontal ligament advantages 1. rapid canine retraction within three weeks. 2. minimal loss of anchorage. 3. minimal effect on root resorption, the vitality of the pulp, and periodontal health. disadvantages 1. needs a unique device for retraction. 2. surgical intervention is required (traumatic). conclusions separate canine retraction with archwire is preferable in anterior teeth crowding and midline discrepancy as the action of trans-septal fibers observes remarkable improvement of anterior teeth crowding. various methods of canine retraction with the archwires were explained in detail regarding their advantages and disadvantages. t-loop is the preferred spring of all because of its characteristics. conflict of interest: none. j. bagh. coll. dent. vol. 35, no. 1. 2023 nahidh et al. 74 references 1. burstone, cj., choy, k. the biomechanical foundation of clinical orthodontics. 1sted. chicago: quintessence publishing co, inc.; 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7(2): 120-126. 26. darendeliler, ma., darendeliler, h., oktayüner, o. the drum spring (ds) retractor: a constant and continuous force for canine retraction. eur j orthod. 1997; 19(2): 115–130. 27. daskalogiannakis, j., mclachlan, kr. canine retraction with rare earth magnets: an investigation into the validity of the constant force hypothesis. am j orthod dentofacial orthop. 1996; 109(5): 489-495. 28. liou, ejw., huang, cs. rapid canine retraction through distraction of the periodontal ligament. am j orthod dentofacial orthop. 1998; 114(4): 372-381. الجزء الثاني -العنوان: الطرق المختلفة لسحب الناب الباحثون: محمد ناهض ، ياسر عبد الكاظم ياسر المستخلص عمليات بحث ، أجريت 2022وفبراير 1930ب المختلفة باستخدام ميكانيكا عدم الحتكاك. الطرق: بين عامي نياراجعة هو مناقشة تقنيات سحب ال الخلفية: الغرض من هذه الم science direct و pubmed central ب المختلفة باستخدام أجهزة تقويم األسنان الثابتة في مجموعة متنوعة من قواعد البيانات ، بما في ذلكنياحول تقنيات سحب ال و البحث اليدوي. النتائج: بعد إزالة المقالت المكررة ، تم تضمين research gate و google scholar و والكتب cochrane ومكتبة wiley online ومكتبة .ب المختلفة باستخدام األسالك المقوسةنيال ت وسلبيات تقنيات سحب ا إيجابيا . الستنتاجات: تمت مناقشةنيابسحب األ ل ية استخدام األسالك المقوسةالمنشورات التي وصفت كيف t-loop هو الزنبرك المفضل من الجميع بسبب خصائصه. farah final.doc j bagh college dentistry vol. 26(2), june 2014 accuracy of spiral oral diagnosis 64 accuracy of spiral computed tomography in evaluation of maxillary sinus septa among dentate and edentulous iraqi subjects (comparative study) farah abdul salam hadi, b.d.s. (1) ahlam a. fatah, b.d.s., m.sc. (2) abstract background: presence of maxillary sinus septa has been known to be a complicating factor for sinus elevation procedure and implant placement in posterior maxilla. the maxillary sinuses septa are thin walls of cortical bone inside the sinus. they vary in number, location, and height. this study aimed to discover the accuracy of spiral computed tomographic scan in evaluation the maxillary sinus septa (prevalence, location, height) in subjects with dentate, partially edentulous and completely edentulous maxilla. material and method: this study included (267) subjects ranged from (20-70 years), (132) male and (135) female divided into three groups, (97) fully dentate group, (102) partially edentulous group and (68) completely edentulous group who admitted to spiral computed tomography scan in al-karkh general hospital in baghdad to have computed tomography scan of the brain and paranasal sinuses for different diagnostic purposes from november 2012 to april 2013. the maxillary sinus septa were evaluated in the axial and sagittal views and the data were subjected to statistical analysis using statistical package for social sciences version 20. result: the prevalence rate of septa was 77.3% among fully dentate maxilla sample. almost the same prevalence rate was obtained in the other two study sample (partially edentulous maxilla 77.5% and completely edentulous maxilla 76.5%).no important or statistically significant difference in prevalence was observed between the three study groups. age and gender showed no important or statistically significant difference in prevalence rate in each study group, the mean septal height was slightly higher in fully dentate group (7mm) compared to partially edentulous maxilla group (6.2 mm) and completely edentulous maxilla group (6.5 mm). the difference in mean between the 3 groups however was not significant statistically. the rate of septa at floor position was significantly lowest in fully dentate maxilla group (36.1%) compared to partially edentulous maxilla group (52.1%) and completely edentulous maxilla group (53.3%). conclusion: spiral computed tomography is a precise diagnostic tool for the examination of this zone capable for investigating their location and height during different maxillary sinus surgical procedures. in the posterior maxilla, regardless of type of ridge (atrophy/edentulous or non-atrophy/dentate), the anatomical variation of sinus septa is diverse in its prevalence and location. keywords: maxillary sinus septa, spiral computed tomography, maxillary sinus surgery. (j bagh coll dentistry 2014; 26(2): 64-68). introduction the maxillary sinus (ms) in the adult consists of a pyramid shaped cavity in the facial skull with its base at the lateral nasal wall and its apex extending into the zygomatic process of the maxilla (1). the proximity of ms to the alveolar crest can be enhanced by sinus pneumatization, as well as resorption of the alveolar ridge due to tooth extraction, trauma or pathology. at the edentate stage of life, the size of ms increases further, often filling a large part of the alveolar process, leaving sometimes only a paper-thin bone wall on the lateral and occlusal sides. this process of pneumatization of the sinus varies greatly from person to person and even from side to side (2). various surgical operations involving the ms in the posterior maxillary region demand adequate knowledge about the possible anatomical variations. exact knowledge of the patient’s morphological condition allows accurate planning (1)m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. of invasive surgery and helps to prevent complications (3,4). the presence of anatomical variations such as maxillary sinus septa (mss) has been reported to hamper the preservation of the mucous membrane lining of ms during the surgical sinus elevation procedure (5-8). underwood (9) first described and analyzed mss as barriers of cortical bone or bony ridges that divide the ms floor into multiple compartments, known as recesses. krennmair et al (10) further classified the septa into primary and secondary septa; primary septa arised from the development of the maxilla, whereas the secondary septa were said to arise from the irregular pneumatization of the sinus floor following tooth loss. evaluation of the anatomical structures inherent to the ms is crucial for the success of sinus surgical procedures. therefore, an exact and definitive radiological assessment is necessary (11,12) . the ct scan is an imaging method that uses x-rays to create cross-sectional pictures of the j bagh college dentistry vol. 26(2), june 2014 accuracy of spiral oral diagnosis 65 body. a computer produces separate image of body area, called slices, were can be stored, viewed on monitor or printed on film. in its simplest form a ct scanner consists of an x-ray tube that emits a finely collimated, fan –shaped xray beam directed through a patient to a series of scintillation detectors or ionization chambers. these detectors measure the number of photons that exit the patient and create the cross-sectional image (13,14). in the present study determination of mss prevalence, location and height by spiral ct was indispensable to prevent possible complications during different sinus surgeries. materials and methods a prospective study consist of (267) iraqi subjects (132 males and 135 females) with age ranged from (20-70) years attended the maxillofacial department at al-karkh general hospital in baghdad city who admitted to have spiral ct scan of the brain and paranasal sinuses for different diagnostic purposes from november 2012 to april 2013. the study sample divided into the following 3 groups: 1) patients with fully dentate maxillae (97). 2) patients with partially edentulous maxillae (102). 3) patients with completely edentulous maxillae (68). criteria for patient’s inclusion and exclusion: the maxillary sinuses included in this study should be asymptomatic and clearly free of any pathology that might obscure the examined regions. exclusion criteria involved: 1. any patients with middle third fractures or maxillofacial deformities. 2. patients with extensive pathological lesions affecting the examined area. 3. patients with a history of previous dentures. identification of mss ct scans for (right & left) maxillary sinuses were taken for each patient. the information obtained was assessed in the (axial and sagittal) sections that may be further manipulated by rotation about any axis to display the septa of maxillary sinus from many angles. these ct scan images were used to identify the mss in order to obtain the following parameters: • the prevalence of mss [one or more septa per sinus] among the 3 study groups (fully dentate, partially edentulous and completely edentulous maxillae) (figure 1). • for the previous 3 study groups, determination of specific septal position at ms (roof, floor, anterior and posterior walls) and determination the type of septa at floor position whether primary or secondary in relation to dentate status. the location of mss in the floor of ms was divided into 3 regions: the anterior (1st and 2nd premolar), middle (1st and 2nd molar) and posterior (behind 2nd molar) regions. • measurement of septal height in millimeters (mm) from the base of septum to the most highest point and correlate it with the dentate status, age and gender of the study sample whether the septum was located in sinus floor, roof, anterior and posterior walls. figure 1: sagittal section shows mss in sinus floor (anterior location) with measurement of its length (15.4) mm. results the total studied samples composed of 267 subjects ranged from (20-70 years).the results were based on three study groups( of both genders). the first group composed of (97 subjects with fully dentate maxilla), the second group composed of (102 subjects with partially edentulous maxilla) and the third group composed of (68 subjects with completely edentulous maxilla). the prevalence rate of maxillary sinus septa by study sample subjects was measured as shown in the table (1). j bagh college dentistry vol. 26(2), june 2014 accuracy of spiral oral diagnosis 66 table 1: prevalence rate of maxillary sinus septa in 3 study groups total positive presence of septa n n % 95% confiden-ce interval (%) p dentate status 0.9 ns fully dentate maxilla 97 75 77.3 (69 to 85.7) partially edentulous maxilla 102 79 77.5 (69.3 to 85.6) completely edentulous maxilla 68 52 76.5 (66.4 to 86.6) the maxillary sinus was taken as the sampling unit, and subjects with positive septa (206) are included only. as shown in table (2), the count of septa per sinus ranged between a minimum 1 to a maximum 6 per a single sinus. table 2: relative frequency and cumulative relative frequency of different values for count of septa per single sinus count of septa n % cumulative % 6 1 0.5 0.5 5 3 1.4 1.9 4 20 9.7 11.6 3 31 15 26.6 2 65 31.4 58 1 86 42 100 total 206 100.0 subjects with positive mss were included in further analysis. the ms septum was taken as (the sampling unit). as shown in table (3), there are four age groups, the first age group which is less than 30 years represents about 28.5% from the whole septa that are found in the three study groups, while in the age group that is more than 60 years it represents 20% from the total septa. for the gender, the septa were found in almost equal distribution between males and females. (the septa were presented in 50.4% in males). table 3: frequency distribution of maxillary sinus septa sample by age and gender n % 1. age group (years) <30 117 28.5 30-44 113 27.5 45-59 99 24.1 60+ 82 20.0 total 411 100.0 2. gender female 204 49.6 male 207 50.4 total 411 100.0 for the dentate status, the septa were found in higher percentage in fully dentate maxilla group38.4% than the other two groups (in partially edentulous maxilla 35.5% and in completely edentulous maxilla 26%).table (4). table 4: frequency distribution of maxillary sinus septa sample by dentate status group n % dentate status fully dentate maxilla 158 38.4 partially edentulous maxilla 146 35.5 completely edentulous maxilla 107 26.0 total 411 100.0 maxillary sinus septa measurements as shown in table (5) the mean septal height was slightly higher in fully dentate group (7mm) compared to partially edentulous maxilla group (6.2 mm) and completely edentulous maxilla group (6.5 mm). the difference in mean between the 3 groups however was not significant statistically. to show the effect of each group of the study sample on the side and position of mss, the following table (6) will discuss the difference in side and position among the 3 groups according to their dentate status. discussion the accurate identification of mss location and height is important for both diagnostic and clinical procedures. as surgery involving the maxillary sinus segment (implant insertion in posterior maxilla, sinus lift procedure) is applied more frequently, radiological evaluation determining the heights and localizations of the septa has gained importance for oral and maxillofacial surgeons (15). shibli et al (16) made a retrospective study in the brazilian population by means of panoramic radiography, the prevalence rate is (21.58%) which is too much less than the prevalence rate in this study for all groups, this is may be due to influential effects like human variability and the type of radiography. logistic regression failed to detect any correlation between the presence of maxillary septa, age, and gender that agree with this study. in 2009 masoumeh et al (17) up on studying a total of 132 sinuses in 66 patients (39 male and 27 female), they found that the prevalence of one or j bagh college dentistry vol. 26(2), june 2014 accuracy of spiral oral diagnosis 67 more septa was 35.52% (27/76) for edentulous and 21.42% (12/56) for dentate patients. these results were largely lower than that of the current study and this may be due to the small sample size used in their study in addition to ethnic variations and alsofound that the mean heights of septa were 6.52 ± 3.87 mm, 7.58 ± 3.56 mm and 5.33 ± 4.23 mm in medial, lateral and middle regions of maxillary sinus, respectively. rosano et al (18)in their cadaveric study found that the septal height with a mean value of 8.72 mm which was slightly higher than the mean height in the present study and this might be related to the type of the study and anatomical variation. kaan et al (15) found that mean height of septa for males was 4.86 +_ 2.01 mm, for females 5.02 +_ 2.14 mm, and this slightly shorter than that in the current study and that might be due to human sample variability. table 5: the mean septal height by selected independent variables septal height (mm) range mean sd se n p dentate status 0.29 ns fully dentate maxilla (1.1 26.3) 7.0 4.6 .37 158 partially edentulous maxilla (1 25.8) 6.2 4.5 .38 146 completely edentulous maxilla (1.5 22.1) 6.5 4.0 .39 107 age group (years) 0.51 ns <30 (1 26.3) 6.3 4.6 .43 117 30-44 (1.3 25.8) 7.1 4.8 .45 113 45-59 (1.4 20.1) 6.5 4.1 .41 99 60+ (1.5 22.1) 6.3 4.0 .44 82 gender 0.05 ns female (1 25.8) 6.2 4.3 .30 204 male (1.5 26.3) 7.0 4.5 .31 207 side (right vs left) 0.95 ns left (1 26.3) 6.6 4.4 .31 208 right (1.1 22.7) 6.6 4.4 .31 203 table 6: the difference in septal side and position among the 3 study groups variables fully dentate maxilla partially edentulous maxilla completely edentulous maxilla sig. n % n % n % p side (right vs left) 0.2 ns left 74 46.8 82 56.2 52 48.6 right 84 53.2 64 43.8 55 51.4 total 158 100.0 146 100.0 107 100.0 septal position roof 76 48.1 60 41.1 31 29.0 0.008 floor 57 36.1 76 52.1 57 53.3 0.005 anterior wall 41 25.9 25 17.1 17 15.9 0.07ns posterior wall 15 9.5 7 4.8 7 6.5 0.27ns references 1. mcgowan da, baxter pw, james j. the maxillary sinus and its dental implications. oxford: wright, butter-worth-heinemann; 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22: 47–53. 16. shibli ja, faveri m, ferrari ds, melo l, garcia rv, d'avila s, figueiredo lc, feres m. prevalence of maxillary sinus septa in 1024 subjects with edentulous upper jaws: a retrospective study. j oral implantol 2007; 33(5): 293-6. 17. faramarzie m, babaloo ar, oskouei sg. prevalence, height, and location of antral septa in iranian patients undergoing maxillary sinus lift. j periodontol implant dent 2009; 1(1): 43-7. 18. gabriele r, taschieri s, gaudy j, lesmes d, del fabbro m. maxillary sinus septa: a cadaveric study. 2010 american association of oral and maxillofacial surgeons. j oral maxillofac surg 2010; 68: 1360-4. maha.doc j bagh college dentistry vol. 27(2), june 2015 time-related oral and maxillofacial surgery and periodontics 115 time-related salivary cathepsin b levels and periodontal status in different orthodontic force magnitudes maha abdul aziz ahmed, b.d.s, m.sc. (1) haraa s. mohammed-salih, b.d.s, m.sc. (2) yassir a. yassir, b.d.s, m.sc. (3) hikmat j. al-judy, b.d.s., m.sc., ph.d. (4) abstract background: biologically active substances, such as cathepsin b (cab) which is a lysosomalcystein protease may be involved in periodontal metabolism in the degradation of organic bone matrix containing collagen fibers in response to mechanical stress from orthodontic appliance. the aims of study were to determine and compare salivary levels of cab, ph as well as clinical periodontal parameters (plaque index pli and gingival index gi) with different orthodontic force magnitudes at different time intervals. materials and methods: a twenty-four patients (both gender) with age range (17-23) years had angle's class ii division 1 malocclusion with gi <0.5 enrolled in this study. the level of salivary cab and ph, in addition to the clinical periodontal parameters (pli and gi) were measured before (baseline), 1 hour (1h), 1 day (1d), 1week (1w), 2 weeks (2w) and 3 weeks (3w) after fixed orthodontic appliance placement with different forces applied to the teeth (f1 (40 gm), f2 (60 gm) and f3 (80 gm)). results: the highest mean concentration of salivary cab was (12.057) at f1 in 1d visit with highly significant differences among the visits as well as among the forces (p≤0.05). weak correlations were revealed between all pairs of forces as well as between each visit with the baseline visit about salivary cab except the strong negative correlations between f1 with f3 at 3w and baseline with 3w visits at f3. maintenance of good oral hygiene during the study period demonstrated that the highest mean values of pli and gi were (0.2) and (0.25) respectively, in addition to the non-significant differences regarding ph among the visits. conclusion: the concentration of salivary cab was increased following fixed orthodontic appliance insertion. the very light continuous orthodontic force could produce significant increase of this enzyme activity and give enough effectiveness to produce tooth movement as compared to the higher forces. key words: cathepsin b, saliva, orthodontic tooth movement, periodontal ligament. (j bagh coll dentistry 2015; 27(2):115-122). introduction host response to orthodontic force alters the vascularity and blood flow of periodontal ligament (pdl), resulting in local synthesis and release of different mediators involved in alveolar bone remodelling(1). these molecules can evoke many cellular responses by various cell types in and around teeth, providing a favorable microenvironment for bone resorption or apposition. although these effects are both physical and biochemical in nature and are frequently intertwined and interdependent (2), the evidence has shown large inter-individual differences in both human researches (3) and animal experiments (4). in other words, with standardized, constant, and equal forces, the rate of orthodontic tooth movement (otm) may vary substantially, while with considerably different forces, the rates of otm may be almost the same among and even within individuals (5). (1)assist. professor department of periodontics, college of dentistry, baghdad university (2)lecturer. department of orthodontics, college of dentistry, baghdad university. (3)assist. professor. department of orthodontic, college of dentistry, baghdad university. (4)assist. professor. department of prosthodontics, college of dentistry, baghdad university. the sequence of events following otm can be characterized using suitable biomarkers. a biomarker is a "substance that is measured and evaluated objectively as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention" (6). applying orthodontic forces to teeth will ultimately result in movement. the main phenomena, both before and after tooth movement, are alveolar bone remodelling, tissue inflammation, and root resorption. each of these events can potentially be detected using suitable markers (7). many of the human studies regarding the biology of otm have focused on the assessment of these biomarkers in gingival crevicular fluid (gcf) (8-10); however, it is difficult to draw firm conclusions because the number of studies concerning variations in the levels of bone remodelling biomarkers through the different phases of otm is sparse and has yielded contradictory results (9,11). cathepsin b (cab), an intracellular lysosomal cysteine proteinase, isolated from many mammalian species (12). it can decompose the extracellular components including collagen and lead to the protein turnover in the lysosomal system in vitro (13).a significant level of cab j bagh college dentistry vol. 27(2), june 2015 time-related oral and maxillofacial surgery and periodontics 116 existed in gcf from gingivitis patients in a study conducted by eisenhauer et al. (14); they concluded that it might play an important role in intercellular protein catabolism in periodontal tissue. although the clinical follow-up examination remains the basis for patient’s evaluation in addition analysis of saliva, which is a complex fluid that contains the systemically and locally derived markers, compelling reasons exist to use saliva as a diagnostic fluid. it meets the demands for in expensive, non invasive and easy to use and collect diagnostic method (15). since, currently, there are no reports on estimating the level of salivary cab during treatment with fixed orthodontic appliances, this study aimed to determine and compare the levels of salivary cab , ph and clinical periodontal parameters (plaque index pli and gingival index gi),before orthodontic appliance placement at baseline and then at different five-time intervals after application of different orthodontic force magnitudes (40gm, 60gm, 80gm) according to the study design, in order to know the ongoing process occur during orthodontic treatment which can result in an appropriate choice of the mechanical loading as well as shortening the treatment period and preventing the adverse effects associated with orthodontic treatment, such as resorption of root or loss of bone. materials and methods human sample a total of twenty-four orthodontic patients (age ranged 17-23 years) ; who were attending the postgraduate clinic of orthodontic department at college of dentistry/baghdad university, were selected to participate in this study according to the following criteria: • all patients had angle's class ii division 1 malocclusion with no crowding or with mild crowding about 2-3mm (16). they all required extraction of bilateral maxillary first premolar teeth as part of their orthodontic treatment. • smoker, drinker, pregnancy and women taking contraceptive pills were excluded from the study • no history of any systemic diseases. • no periodontal treatment and not use of any anti-inflammatory or antimicrobial medications 3 months prior the study period. • clinically healthy periodontium, mean without pocket nor attachment loss and no radiographic evidence of periodontal bone loss. • no missing teeth. we certify that this study involving human subjects is in accordance with the helsinki declaration of 1975 as revised in 2000 and that it has been approved by the relevant institutional ethical committee. study design two weeks before orthodontic appliance placement, all patients underwent a session of motivation, oral hygiene instructions and accurate supra and sub gingival ultrasonic scaling. oral hygiene status of the patients was determined before initiating the experimental procedures. thus only patients with gi<0.5 (17) were included in this study. the fixed orthodontic appliance design used in this study was according to a previous study conducted by abdul ameer (18) which consisted of sectional stainless steel straight wire (ortho technology, usa), a bracket (roth 0.022 slot, orthoclassic) on the maxillary first premolar which was indicated for extraction, and a molar tube (ortho technology, usa) on the maxillary first molar for each side. the arch wire was bent just mesial to the molar tube in a labial direction to apply a labial force on the maxillary first premolar. those patients were divided into three groups (8 patients for each group) according to different continuous orthodontic force magnitudes applied, group f1: subjected to 40 gm force, group f2: subjected to 60 gm force and group f3: subjected to 80 gm force. this force was measured by a strain gauge (0-500 grams, ortho technology, usa); and the arch wire was ligated to the maxillary first premolar bracket by a stainless steel ligature wire. saliva collection the patients should not drink or eat within at least one hour before collection of the saliva. the patient asked to sit in a comfortable position and spit 5 ml of unstimulated whole saliva into sterile plane plastic test tube within 10 minutes and put in cooling box to stop the growth of bacteria. the samples were taken from each patient and salivary ph was measured by using an electronic ph meter prior to fitting the orthodontic appliance at baseline and then 1 hour (1h), 1 day (1d), 1week (1w), 2 weeks (2w) and 3 weeks (3w) after force application to the teeth. after collection, the whole saliva was centrifuged at 3000 rpm for 20 min to remove insoluble material by using centrifuge machine. the supernatants saliva were collected by pipette into eppendrof tubes and frozen at -20o c until biochemical analysis. j bagh college dentistry vol. 27(2), june 2015 time-related oral and maxillofacial surgery and periodontics 117 clinical periodontal parameters examination clinical periodontal parameters examination was performed according to gi (17) and pli (19) systems after salivary sample collection at six time intervals by using michigan o periodontal probe on four surfaces (buccal/ labial, lingual/ palatal, mesial and distal) of all teeth except 3rd molar. assay of salivary cab level frozen saliva supernatant should be thawed at room temperature and salivary cab level (mg/ml) was detected by mean of enzyme linked immune sorbent assay (elisa) kit (shanghai crystal day biotech co., ltd, china) according to the manufacturer instructions. statistical analysis statistical analyses were made with the windows statistical software spss (version 15.0, spss inc., chicago, il, usa). descriptive statistics including means and standard deviations (sd), and inferential statistics for inter-group comparisons including one-way analysis of variance (anova) with least significant difference (lsd) and correlation coefficient were used. the level of significance was set at p≤0.05. results table (1) revealed that the highest mean value of pli was (0.2) present in patients subjected to f3 at 1w visit with highly significant differences among the visits at each force. while (0.25) was the highest mean value of gi presented by subjects with f1 and f2 at 1h and 1d visits respectively with highly significant differences among the visits at f2and f3, whereas anonsignificant difference at f1. the highest mean values of ph were (7.499) at f1, (7.223) at f2 and (7.299) at f3 demonstrated at 1h visits in all force groups with non-significant differences among the visits at each force. the highest mean concentrations of salivary cab were (12.057) and (10.445) at f1 and f2 demonstrated in 1d visit, while at f3 it was (11.788) in 2w visit, with highly significant differences among the visits at each force, as well as among the forces at each visit except the significant difference at 1w visit, as shown in (table 2, figure 1). from (table 3) highly significant differences of salivary cab levels were revealed between all pairs of forces at each visit except the significant differences between f2 with f3 and f1 at 1d and 1w visits respectively and non-significant differences between f1 with f2 at 1h and 3w visits, as well as, between f1 with f3 at 1w visit. furthermore,(table 4)illustrates the comparisons between all pairs of visits at each force regarding the levels of salivary cab, the results were highly significant differences except the non-significant differences between 1h with 1w at f1 and f2,baselinewith 2w at f2, as well as 1h with 3w and 1d with 1w at f3.hence a significant difference presented between baseline with 2w at f1. weak correlations were demonstrated between all pairs of forces at each visit about the mean concentrations of salivary cab except the strong negative correlation between f1 with f3at 3w visit, hence, moderate negative correlation between f1 with f2 at 2w visit was revealed, (table 5). however, the correlations between each visit with baseline visits at each force were weak except the strong negative correlation of 3w visit at f3, and the moderate correlation of 1d and 1h at f1and f2 respectively that were negative, while it was positive at 3w in f1, (table6). generally, weak correlations were revealed between all pairs of visits (excluded the baseline visits) at each force, but the results showed strong and moderate negative correlations between 1h with 3w and 2w visits respectively at f1, while at f2,strong positive correlation presented between 2w with 3wvisits, on the other hand, regarding f3, strong positive correlations demonstrated between 1d with 1h as well as, 2w with both 1d and 1w visits, while they were strong negative between 3w with 1w and 2w visits. j bagh college dentistry vol. 27(2), june 2015 time-related oral and maxillofacial surgery and periodontics 118 table 1: statistical analysis of pli, gi and ph for all visits at each force forces periodontal parameters statistical analysis visits anova baseline 1 h 1 d 1 w 2 w 3 w f-test pvalue f1 pli mean 0.000 0.125 0.175 0.138 0.113 0.088 6.575 0.000 *** sd 0.000 0.100 0.089 0.052 0.035 0.064 gi mean 0.000 0.250 0.150 0.112 0.237 0.137 2.372 0.055 sd 0.000 0.200 0.169 0.124 0.243 0.159 ph mean 7.184 7.499 7.386 7.124 6.959 7.129 0.565 0.727 sd 0.603 0.637 0.802 0.712 0.975 0.630 f2 pli mean 0.000 0.069 0.125 0.188 0.194 0.188 9.812 0.000 *** sd 0.000 0.088 0.071 0.083 0.062 0.083 gi mean 0.000 0.150 0.250 0.138 0.100 0.088 5.966 0.000 *** sd 0.000 0.120 0.139 0.092 0.093 0.064 ph mean 6.929 7.223 7.083 6.688 6.966 6.835 0.480 0.789 sd 0.460 0.654 0.609 1.068 0.802 0.835 f3 pli mean 0.000 0.125 0.175 0.200 0.188 0.163 8.872 0.000 *** sd 0.000 0.089 0.046 0.076 0.095 0.069 gi mean 0.000 0.175 0.125 0.100 0.110 0.075 4.631 0.002 *** sd 0.000 0.139 0.089 0.076 0.011 0.046 ph mean 6.916 7.299 7.078 6.986 6.730 6.970 1.661 0.165 sd 0.373 0.406 0.373 0.428 0.495 0.383 *** highly significant, **significant, significance was set at p≤0.05 table 2: statistical analysis of salivary cab concentration (mg/ml) for all visits at each force salivary cab visits f1 f2 f3 anova d.f. = 23 mean sd mean sd mean sd f-test p-value baseline 6.015 0.722 4.886 0.727 8.238 0.539 52.128 0.000*** 1 h 8.735 0.319 8.421 0.680 10.778 0.398 54.348 0.000*** 1 d 12.057 1.256 10.445 0.299 9.410 0.376 23.600 0.000*** 1 w 8.814 0.603 8.053 0.739 9.224 0.800 5.467 0.012** 2 w 6.758 0.418 5.112 0.996 11.788 0.821 157.643 0.000*** 3 w 4.156 0.489 3.854 0.679 10.769 0.704 306.513 0.000*** f-test 121.047 101.808 33.783 anova d.f. = 47 p-valeu 0.000*** 0.000*** 0.000*** figure 1: mean concentration of salivary cab (mg/ml) for the three forces at each visit. bars represent mean ± se: (set at 95% ci for mean). j bagh college dentistry vol. 27(2), june 2015 time-related oral and maxillofacial surgery and periodontics 119 table 3: inter-forces comparisons of the mean concentrations of salivary cab at each visit table 4: inter-visits comparisons of the mean concentrations of salivary cab at each force visits f1 f2 f3 p p p baseline 1 h 0.000*** 0.000*** 0.000*** baseline 1 d 0.000*** 0.000*** 0.001*** baseline 1 w 0.000*** 0.000*** 0.003*** baseline 2 w 0.041** 0.530 0.000*** baseline 3 w 0.000*** 0.006*** 0.000*** 1 h 1 d 0.000*** 0.000*** 0.000*** 1 h 1 w 0.825 0.310 0.000*** 1 h 2 w 0.000*** 0.000*** 0.003*** 1 h 3 w 0.000*** 0.000*** 0.979 1 d 1 w 0.000*** 0.000*** 0.558 1 d 2 w 0.000*** 0.000*** 0.000*** 1 d 3 w 0.000*** 0.000*** 0.000*** 1 w 2 w 0.000*** 0.000*** 0.000*** 1 w 3 w 0.000*** 0.000*** 0.000*** 2 w 3 w 0.000*** 0.001*** 0.002*** table 5: correlations of the mean concentrations of salivary cab between all pairs of forces at each visit visits f1-f2 f1-f3 f2-f3 r p r p r p 1 h -0.311 0.454 -0.227 0.589 0.183 0.665 1 d -0.256 0.540 0.403 0.323 -0.464 0.247 1 w 0.208 0.621 0.132 0.756 0.124 0.769 2 w -0.587 0.126 0.226 0.591 0.166 0.694 3 w 0.006 0.989 -0.822 0.012** -0.361 0.379 table 6: correlations of the mean concentrations of salivary cab between different visits with baseline visits at each force visits f1 f2 f3 baseline baseline baseline r p r p r p 1 h -0.191 0.650 -0.508 0.199 -0.150 0.723 1 d -0.562 0.147 0.294 0.480 0.124 0.770 1 w 0.045 0.915 0.303 0.466 0.190 0.652 2 w 0.124 0.770 0.407 0.317 0.197 0.640 3 w 0.643 0.085 0.226 0.591 -0.765 0.027** visits forces p-value 1 h f1 f2 0.215 f1 f3 0.000*** f2 f3 0.000*** 1 d f1 f2 0.000*** f1 f3 0.000*** f2 f3 0.015** 1 w f1 f2 0.046** f1 f3 0.267 f2 f3 0.004*** 2 w f1 f2 0.000*** f1 f3 0.000*** f2 f3 0.000*** 3 w f1 f2 0.349 f1 f3 0.000*** f2 f3 0.000*** j bagh college dentistry vol. 27(2), june 2015 time-related oral and maxillofacial surgery and periodontics 120 discussion in the present study, very minimal plaque accumulation with excellent gingival health were detected during the study period, this is due to the oral hygiene instructions and motivation given to each participant before and throughout the study. it has been reported in previous studies that oral hygiene and gingival health maintenance were possible during orthodontic treatment when good knowledge, attitude, practice of gingival health were applied (20,21). as well as, there were very low non-significant increase in salivary ph in all groups of forces throughout the study and reach its maximum level after 1h of appliance placement. this is may be attributed to the maintenance of good oral hygiene through the study period and due to the fact that there was an increase in salivary flow usually occur after placement of orthodontic appliance (22). people experience changes in salivary function over time, and these changes have a long-term of clinical significance (23-25). some studies have detected associations between fixed orthodontic appliances, microbial outcomes, and measures of salivary function; hence the results were not consistent. lara-carrillo et al. (23) concluded in their study that orthodontic treatment changes the oral environmental factors including promotes a major salivary stimulated flow rate and increases its buffer capacity and salivary ph, whereas alessandri bonetti et al. (26) found in their study that after 1 year of the placement of fixed orthodontic appliances the salivary ph, buffer capacity and flow rate were not change when compared with the baseline assessment. previous studies showed an increase in cab level in gcf of orthodontic patients with a higher relation to the periodontal diseases (2729). eley and cox (27) found a positive correlation between cab activities in gcf with clinical periodontal parameters of untreated chronic periodontitis. then those authors found a reduction in all these parameters after periodontal treatment (28). therefore, prevention of plaque-induced inflammation with excellent gingival health and normal salivary ph allowed this study to focus mainly on the process of mechanical stimulation of salivary cab in during orthodontic treatment at different force magnitudes. various investigations considered different orthodontic duration to examine the effect of several enzymes and biological mediators in their studies, whereas in this study the appropriate duration of an orthodontic cycle was 21 days had been considered, in order to identify and understand the enzymatic changes occur during early stages of orthodontic force application in coincidence with initial and lag phases of tooth movement, therefore, in our study salivary sample collection continued until the end of 3weeks after appliance placement. periodontal tissue vascularity and blood flow usually affected by mechanical loading, thus result in the formation and release of different mediators locally, such as cytokines e.g. interlukine-6, enzymes, growth factors and the neurotransmitters (7). the biological mechanisms controlling the change from the stimulus, consist of continuous force application, to the reaction, represented by the displacement of the tooth in the periodontal space, and could be estimated by measuring the lower or higher rate of such biomarkers in gcf or saliva. a study conducted by frodge et al. (30) showed that different mediators involved in alveolar bone remodelling are continuously washed into saliva from gcf , whole-saliva samples may constitute an easy alternative to individual gingival sulcular samples for determining analytes of bone turnover that are present within the periodontal environment, providing a sensitive and inexpensive detection technique. cathepsin b, play a role in the resolve of the organic matrix, the last step in resorption of bone. cab was elevated around the osteoclasts; it involved in the degradation of exposed collagen fibers and collagen degradation by products (31). the results from the present study regarding the overall quantitative changes of salivary cab concentration showed significant increase in its level at all the three force groups immediately after 1h of appliance placement, this is due to the fact that otm is purely described as an aseptical and transitory inflammatory process (1) and cab is recognized to play an important role in the starting and continuation of such processes as in previous studies (32-36) that showed higher accumulation of cab in gcf with otm and which could be directly reached into saliva. eventhough, in this study its highly significant increase in quantitative level reaches after 1d of appliance placement in f1 and f2 groups, these findings are similar to those by sugiyama et al. (35) where high significant increase in cab level occurs in gcf of the teeth at the treated sites as compared to those at the control sites after 1d of force application. however; comparison with this study is difficult due to many technical variations like study design, gcf collection and the initial force used was 250gm. these results indicate that this enzyme is a product of cells in alveolar bone and pdl like osteoblast, osteoclast, fibroblast and macrophages when they were exerted to any j bagh college dentistry vol. 27(2), june 2015 time-related oral and maxillofacial surgery and periodontics 121 factor exceeds the normal physiological limits such as pathological condition or mechanical deformation (32-36). sasaki and uenomatsuda (32) reported that cab is involved in the formation of resorption lacunae by means of intra and extracellular degradation of collagen and other noncollagenous matrix proteins of primary teeth. moreover, goseki et al. (37) found an in vitro relation between high cab activities with progression of pdl cellular aging. it has also been reported that interlukine-6 increases cab activity in human pdl cells (34). therefore, cab may be involved in periodontal metabolism through the degradation of organic bone matrix containing collagen fibers (33). immunocytochemical study by nogimura (36) demonstrated increased detection of cab in pdl fibroblasts and osteoclasts of rat molar following experimental tooth movement; this proves that cathepsins play an important role in starting otm by initiating bone resorption. however, there were few studies on the biological role of cab during otm hence all these investigations assessed its relation to otm as a mediator of inflammation and bone remodelling process which can be detected in gcf or in saliva. in the present study salivary cab level showed gradual and steady decrease in f1 and f2 groups (however in f1 more than in f2 group) till the end of the study. it has been thoroughly acknowledged that in the earlier phases of tooth movement, bone resorption is greater than bone apposition, but in a later phase, resorption and apposition can become synchronous (38). whereas, its level in f3 group showed fluctuant significant differences between every sampling visit, except for the pairs baseline visit with 1d and 1week visits. it is quite probable that the increasing and decreasing trend of salivary cab values may be due to collagen breakdown resulting from higher magnitude of mechanical loading (80gm), ischemia, and hypoxia, which appear immediately after force application and last throughout most of the initial and lag phase of otm (11).although the elevation observed in f1 and f2 groups at 1d visit in comparison to baseline examination, it might be associated with the initial shift of the teeth within the pdl space and early bone resorption observed during the initial phase of otm (38). moreover, in the lag phase (2w visit), salivary cab level at f3 showed a significant increase regarding baseline examination. these findings could be attributed to the effect of higher force magnitude on periodontium and bone remodelling process. altogether, these salivary findings might be a reflection of the actual enzymatic profile of gcf and consequently of the biologic activity within the periodontal environment during otm (39). in conclusion, cab can be used as a marker in otm. the light continuous orthodontic force could produce the significant and reliable increase of this enzyme activity and give enough effectiveness to produce steady tooth movement with less adverse effects on the surrounding structures as could be present in higher forces. references 1. garlet tp, coelho u, repeke ce, silva js, cunha fdq, garlet gp. differential expression of osteoblast and osteoclast chemmoatractants in compression and tension sides during orthodontic movement. cytokine 2008; 42(3): 330-5. 2. krishnan v, davidovitch z. on a path to unfolding the biological mechanisms of orthodontic tooth movement. j dent res 2009; 88(7): 597-608. 3. iwasaki lr, crouch ld, tutor a, gibson s, hukmani n, marx db. tooth movement and cytokines in gingival crevicular fluid and whole blood in growing and adult subjects. am j orthod dento facial orthop 2005; 128(4):483-91. 4. van leeuwen ej, maltha jc, kuijpers-jagtman am. tooth movement with light continuous and discontinuous forces in beagle dogs. eur j oral sci 1999; 107(6): 468-74. 5. ren y, maltha jc, van’t hof ma, kuijpers-jagtman am. optimum force magnitude for orthodontic tooth movement: a systematic literature review. angle orthod 2003; 73(1): 86-92. 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(2)b.d.s., m.sc., ph.d. , radhinada j. abstract background: water-pipe can be defined as a single or multi stemmed device that used to vaporize and smoke flavored tobacco whose smoke is passed via water vase before inhalation. water-pipe smokers are at risk of exposure to many toxic chemicals that are not filtered by water, as well as risk of infectious diseases when the mouth piece of the water-pipe is shared. this study was carried out to investigate the effect of water pipe on the oral health. materials and methods: sixty persons were included in this study aged between 22 and 23 years. forty persons were coffee shop workers for at least five years, half of them were water-pipe smokers (active smokers) and the other weren’t smokers (passive smoker), the last group was the control group which includes twenty non-smoker students matching the study group in the age, gender and geographical location. they had been diagnosed for plaque index of silness and leo in1964, calculus index according to calculus component of the periodontal disease index, (pdi) of ramfjord 1959 and gingival index of löe and sillness 1963 as well as loss of attachment according to criteria of who in1997. the values of the present study were subjected to statistical analysis by statistical package for social sciences version 20 to specify the statistical differences between the three groups. the kruskal-wallis test was used to determine the statistical significance of difference between the three groups. mann-whitney test was used to assess the statistical significance of difference between each 2 groups. results: the mean rank values of dental plaque were recorded to be the highest among the coffee shop workers who were active water-pipe smokers group followed by the workers who were passive water-pipe smokers then control with statistically highly significant difference. similar results were obtained concerning gingival and calculus indices with statistically highly significant difference. there is no significant difference concerning the attachment loss attachment loss among water-pipe smokers and the control group. conclusions: this study concluded that water-pipe smoking is negatively associated with the oral cleanness and gingival health. keywords: water-pipe, plaque, calculus and periodontal disease ز(received: 11/8/2018; accepted: 16/9/2018) introduction water-pipe considered as a device used by millions of people in order to smoke tobacco and other substances, such as molasses, flavoring agents and herbal medicament, it works by heating up the air by charcoal then it passes via perforated aluminum foil toward the tobacco and other constituents then the air is cooled by water in the bowel before it will be inhaled by the smokers to reach their lungs (1). it was found that one gathering of water-pipe can consume smoke volume reaches to one hundred times more than cigarette (2). water-pipe contains about 70 chemical compounds that can directly cause cancer, in addition to other constituents which considered as cancer promoters (3). periodontal disease is a chronic bacterial infection characterized by a complex inflammation of the tooth supporting tissues including gingiva, periodontal ligament, cementum and alveolar bone; it includes gingivitis and periodontitis (4). studies revealed that water-pipe smoking may adversely aggravate the gingival health and increase the occurrence as well as the severity of the periodontal disease (5,6). (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. on the other hand, dental plaque is a sticky soft nonmineralized bacterial deposit that can be recognized clinically when it reaches a certain thickness. it forms and firmly adhere to the hard surfaces in the oral cavity including the teeth, removable and fixed restorations (7,8), it considered as a primary causative factor of caries and periodontal disease (9). authors found that dental plaque was higher among water-pipe smokers than those who were nonsmokers (10,11), others studied the relationship between tobacco in cigarette to dental plaque and they reached to similar results (12-14). while bergström et al. (15) didn’t find any significant difference between the smokers and non-smokers (15). dental calculus is a hard deposit that forms by dental plaque mineralization, it has a rough surface and considered as an ideal medium for further plaque deposition that threatening the gingival health (8). javed et al (11) demonstrated that dental calculus index was higher among water-pipe smokers when compared with those who were non-smokers. the aim of this study was to investigate the oral health status including oral cleanness and gingival health among active and passive water-pipe smoking groups in comparison to the control group. as far as, no iraqi study was conducted to investigate the negative effects of water pipe smoking on oral health among coffee shops workers. (1) ministry of health, al-najaf, iraq. j bagh college dentistry vol. 30(4), december 2018 oral cleanness and 51 materials and methods this study was carried out during the period from the end of november, 2017 till the end of february, 2018. the consent was gained from ash-sheikh altousi university college to examine their students as a part of the sample without obligation, to ensure cooperation from college authority. the study included sixty male persons, aged between 22 and 23 years old who lived in najaf city/ iraq. they were divided into three equal groups: coffee shop workers for at least five years and considered as water-pipe smokers (active smokers), coffee shop workers for similar period but without being smoker to the water pipe (passive smokers), the last group was the control group who were without history of active nor passive smoking. clinical examination to the sample was performed by using plane mouth mirror and dental probe. in this study dental plaque was coded according to the criteria described by silness and leo 1964 (16) in which the examination included only six teeth of the permanent dentition which were 16, 12, 24, 36, 32 and 44. meanwhile, dental calculus was evaluated according to calculus component of the periodontal disease index, (pdi) of ramfjord 1959 (18). gingival inflammation was evaluated by the application of gingival index (gi) of löe and sillness 1963 (17) loss of attachment was measured by community periodontal index (cpi) (19) the values of the present study were subjected to statistical analysis by using spss version 20 (statistical package for social sciences) to specify the statistical differences between the three groups. non-normally distributed variables were conveniently described by median and mean rank. the kruskal-wallis test was used to determine the statistical significance of difference between the three groups. however, mann-whitney test was used to assess the statistical significance of difference between each two groups. p value of less than or equal the 0.05 level of significance was considered to be statistically significant. results table (1) shows the median and mean rank of plaque index among different water-pipe smoking categories, the mean rank of plaque index was higher among active waterpipe smoker category (p < 0.001), followed by passive water-pipe smoker category then the control category. mann-whitney test was used to compare between each two categories of water-pipe smoking. the result showed that the plaque index (pi), represented by mean rank, was lower among the control category than the active water-pipe smoking category with highly significancy (z=4.457, p= 0.000), and lower than the passive water-pipe smoking category with highly significant difference (z=3.180, p=0.004). while the mean rank among the active water-pipe smoking was higher than passive water-pipe smoking category. however, there was no statistical significance difference between the active water-pipe and the passive water-pipe smoking category (z=1.277, p=0.604). the mean rank of calculus index according to the categories of water-pipe smoking is shown in table (2). higher value of mean rank was observed among the active water-pipe smoking category, compared to the passive water-pipe smoking and control categories with statistically highly significant difference (p≤ 0.01). highly significant difference was found between the control and the active category and between the control with the passive water-pipe smoking categories separately (z=5.222, 3.481; p= 0.000, 0.001 respectively). although, the mean rank for active water-pipe smoking categories was more than passive water-pipe smoking category, there was no statistical significant differences (z=1.741, p= 0.245). table 1: plaque index (median, mean rank) among water-pipe smokers in comparison to control group. water-pipe smoking categories no median mean rank statistical differences pair wise comparison adjustment significance chivalue p active smokers 20 1.58 41.05 21.071 0.000** active smoker × control 0.000** passive smokers 20 1.40 34.00 passive smoker × control 0.004** control 20 0.35 16.45 active smoker × passive smoker 0.604 ** highly significant p ≤ 0.01 j bagh college dentistry vol. 30(4), december 2018 oral cleanness and 51 table 2: calculus index (median, mean rank) among water-pipe smokers in comparison to control group. water-pipe smoking categories no median mean rank statistical differences pair wise comparison adjustment significance chivalue p active smokers 20 0.25 43.00 28.278 0.000** *** active smoker × control 0.000** passive smokers 20 0.17 33.63 passive smoker × control 0.001** control 20 0.00 14.88 active smoker × passive smoker 0.245 ** highly significant p ≤ 0.01 severity of the gingival inflammation among the subjects according to different categories of waterpipe smoking, mild type gingivitis was higher among the control category than other categories. for moderate type gingivitis, it was more among active water-pipe smoking category. while sever gingivitis was observed among active water-pipe smokers only (table 4). concerning attachment loss, in the present study there was no attachment loss recorded among neither the control group nor the active water-pipe smokers. however, among the passive smokers attachment loss was observed among one person only at one tooth and it was recorded as a (degree 1) among one person only, at one tooth (four surfaces). the mean rank of gingival index for the water-pipe smoking categories is shown in table (3). higher value of mean rank was observed among the active water-pipe smokers category, compared to the other groups with statistically highly significant difference (p= 0.005). regarding the differences between each two groups, there was highly significant difference between the control with the active group and between the control with the passive water-pipe smokers categories (z= 3.984, 3.549; p=0.000, 0.001 respectively). in spite of the mean rank of the gingival index for the active water-pipe smoking category was more than that of the passive water-pipe smoking category, there was no statistical significant differences (z=0.435, p=1.000). concerning the table 3: gingival index (median, mean rank) among water-pipe smokers in comparison to control group with statistical difference. water-pipe smoking categories no median mean rank statistical differences pair wise comparison adjustment significance chi value p active smokers 20 1.54 38.63 19.103 0.000** active smoker × control 0.000** passive smokers 20 1.48 36.23 passive smoker × control 0.001** control 20 0.33 16.65 active smoker × passive smoker 1.000 ** highly significant p ≤ 0.01 table 4: distribution of water-pipe smokers and the control groups according to severity of gingivitis water –pipe smoking categories active smokers passive smokers control no % no % no % mild (0.1-1) 2 10.0 5 25.0 16 80.0 moderate (1.1-2) 16 80.0 15 75.0 4 20.0 sever (2.1-3) 2 10.0 j bagh college dentistry vol. 30(4), december 2018 oral cleanness and 51 discussion in the present study, plaque index was higher among the active water-pipe smokers followed by the passive smokers than the control with a statistically significant difference and this result was in consistent with other studies (10,11). this results is agrees with previous studies done on cigarette smoking (12,13), that explained this heterogeneity in plaque level by differences in presence of periodontal pathogens between tobacco smokers and non-smokers. also the result of present study was in agreement with darby et al. (16) who assumed that the smoking increases the periodontal pathogens. thus, increase plaque accumulation may be due to other reasons rather than smoking such as poor oral hygiene (20). on the other hand, other study didn’t find a significant difference in plaque level between tobacco smokers and nonsmokers (12). the present study revealed that the calculus index was higher among active and passive smokers than control group. this result was in agreement with bibars et al. (10) and javed et al. (11). while it disagreed with a study of jenkins et al. (20) who studied the association between tobacco at cigarette and calculus formation and they disproved any correlation and assuming that there were many factors affect dental calculus including the amount of dental plaque, and poor oral health. in order to provide precise evidence of the relationship between the amount of the gingival inflammation and dental plaque, the gingival index of loe and sillness(17) was used together with the plaque index of silness and loe(18). these indices were used because their application was easy in addition to their flexibility which provides the possibility of selection of certain teeth for examination rather than the whole dentition and the minimum duration of the examination (21). in this study gingival index was significantly higher among active and passive waterpipe smokers than the control group while there was no significant difference between active and passive smokers, this result was in agreement with many studies (6,22, 23). while it disagreed with others (11,24) who stated that smoking lead to reduced inflammatory response, this finding was in coincide with numerous epidemiological and clinical studies reported previously with regard to cigarette smoking (25-29). palmer et al. (29) illustrated the correlation between tobacco and periodontal disease by the effect of tobacco in decreasing oxygen and other blood constituents to reach gingiva which would reducing the capacity to remove tissue waste products leading to compromising the immune response and the periodontal tissue destruction. in addition, hanioka et al. (30) assumed that gingival health could be affected by smoking due to functional impairment in the gingival microcirculation, which might be associated with alteration of the subgingival micro-flora. while scott & singer (31) reached to similar results and they hypothesized that tobacco was responsible for restriction of periodontal angiogenesis responsiveness to dental plaque bacteria, they suggested that tobacco smoking components could restrict the periodontal angiogenesis in response to plaque bacteria. data of the current study showed that there was no impact of the water-pipe on the loss of attachment since there wasn’t a significant difference between water-pipe smokers and control group. this result disagreed with other studies (10,11) since they reached that tobacco smoking lead to up regulation of pro-inflammatory cytokine that lead to attachment loss and bone loss. the heterogeneity in prevalence of attachment loss among water-pipe smokers may be attributed to the age included in the sample that was not exceed 23 years. conclusion this study concluded that water-pipe smoking might contribute to increase the susceptibility to periodontal disease, in addition to its role in rising both plaque and calculus levels that negatively affect the oral health. references 1. world health organization: tobreg advisory note. water-pipe tobacco smoking: health effects, research needs and recommended actions by regulators geneva: world health organization. 2005. 2. aljarrah k, ababneh q, delaimy w. perceptions of hookah smoking harmfulness: predictors and characteristics among current hookah users. tobacco induced diseases. 2009; 5:16. 3. hashim, r., thomson, w.m. and pack, a.r. smoking in adolescence as a predictor of early loss of periodontal attachment. community dent oral epidemiol. 2001; 29(2), pp.130-135. 4. yamamoto, m., kobayashi, r., kono, t., bolerjack, b., gilbert, r. induction of il-10-producing cd4t-cells in chronic periodontitis. j dent res2011; 90(5): 653-658. 5. waziry r, jawad m, ballout ra, al akel m, akl ea. the effects of waterpipe tobacco smoking on health outcomes: an updated systematic review and meta-analysis. int j epidemiol. 2017. epub ahead of print. 6. ramoa cp, eissenberg t, sahingur se. increasing popularity of waterpipe tobacco smoking and electronic cigarette use: implications for oral healthcare. j periodontal res. 2017; 52:813-23. 7. dumitrescu al. etiology and pathogenesis of periodontal disease. new york: springer, 2010. 8. marya a. textbook of public health dentistry.1st ed. jaypee brothers, new delhi, 2011. 9. kumar s, patel s, tadakamadla t, tibdewal j, duraiswamy p, kulkarni s. effectiveness of a mouthrinse j bagh college dentistry vol. 30(4), december 2018 oral cleanness and 51 containing active ingredients in addition to chlorhexidine and triclosan compared with chlorhexidine and triclosan rinses on plaque, gingivitis, supragingival calculus and extrinsic staining. int j dent hygiene. 2013; 11: 3540.cited. 10. bibars ar, obeidat sr, khader y, mahasneh am, khabour of. the effect of waterpipe smoking on periodontal health. oral health prev dent 2015;13:253259. 11. javed f, al-kheraif aa, rahman i, millan-luongo lt, feng c, yunker m, malmstrom h, romanos ge comparison of clinical and radiographic periodontal status between habitual water-pipe smokers and cigarette smokers. j periodontol 2016;87:142-147. 12. stoltenberg jl, osborn jb, pihlstrom bl, herzberg mc, aeppli dm, wolff lf, et al. association between cigarette smoking, bacterial pathogens, and periodontal status. j periodontol. 1993; 64:1225-1230. 13. preber h., linder l., bergström j. periodontal healing and periopathogenic microflora in smokers and non-smokers. j clin periodontol. 1995; 22:946-952. 14. darby ib, hodge pj, riggio mp, kinane df. microbial comparison of smoker and non-smoker adult and earlyonset periodontitis patients by polymerase chain reaction. j clin periodontol. 2000; 27:417-424 15. bergström j. eliasson s., preber h. cigarette smoking and periodontal bone loss. j periodontol. 1991; 62:242-246. 16. silness j, loe h. periodontal disease in pregnancy. correlation between oral hygiene and periodontal condition. acta odont scand 1964; 22: 121-35. 17. loe h, silness j. periodontal disease in pregnancy i. acta odonto scand 1963; 21:533-551. 18. ramfjord s. indices for prevalence and incidence of periodontal disease. j. periodontal. 1959; 30: 51-9. 19. world health organization. oral health surveys. basic methods. 4th ed. geneva. 1997. 20. jenkins c, pham xd, do hn, et al (1997). tobacco use in vietnam. prevalence,predictor and the role of the transnational tobacco corporations. jama 277: 17261731. 21. ciancio sg. current status of indices of gingivitis. journal of clinical periodontology 1986; 13:5, 375-378. 22. albandar jm, streckfus cf, adesanya mr, winn dm. cigar, pipe, and cigarette smoking as risk factors for periodontal disease and tooth loss. journal of periodontology. 2000;71:1874–1881. 23. akl, e.a., gaddam, s., gunukula, s.k., honeine, r., abou jaoude, p., irani, j. the effects of waterpipe tobacco smoking health outcomes: a systematic review. international journal of epidemiology. 2010; 39, 834-857. 24. natto s, baljoon m, dahlen g, bergstrom j. tobacco smoking and periodontal microflora in a saudi arabian population. j clin periodontol 2005; 32:549-555. 25. bergstrom j, floderus-myrhed b. co-twin control study of the relationship between smoking and some periodontal disease factors. community dent oral epidemiol 1983; 11, 113-116. 26. preber h, bergström j (1985b). occurrence of gingival bleeding in smokers and nonsmokers patients. acta odontol scand 43: 315-320. 27. danielsen b, mannjif, nagelkerke n, fegerrrskov o, baelum v. effect of cigarette smoking on the transition dynamics in experimental gingivitis. j clin periodontol 1990; 17:159-164. 28. lie m, timmerman m, valden u, weijde n g. evaluation of two methods to assess gingival bleeding in smokers and non-smokers in natural and experimental gingivitis. j clin periodontol 1998; 25: 695-700. 29. palmer r, scott d, meekin t, poston r, odell e, wilson r. potential mechanisms of susceptibility to periodontitis in tobacco smokers. j periodontol tes 1999; 34: 363-369. 30. hanioka t, tanaka m, ojima m, takaya k, matsumori y, shizukuishi s. oxygen sufficiency in the gingiva of smokers and non-smokers with periodontal disease. j perodontol 2000; 71: 1846-1851. 31. scott d, singer d. suppression of vert gingival inflammation in tobacco smokers-clinical and mechanistic consederations. int j dent hygiene 2004; 2:104-110. المستخلص الى او متعدد يستعمل لتبخير وتدخين التبغ المنكه، حيث بتم تمرير الدخان خالل وعاء يحتوي على ماء قبل االستنشاق. يتعرض مدخنو االركيلة الخلفية: االركيلة هي عبارة عن اداة ذات جذع منفرد ي من االركيلة. موالعديد من المواد الكيميائية السامة التي ال يصفيها وعاء الماء باالضافة الى خطر انتقال االمراض المعدية في حال مشاركة الجزء الف هدف الدراسة: اجريت هذه الدراسة للتحري عن نظافة الفم وصحة اللثة بين مدخني االركلية. عامال من عمال المقاهي لمدة ال تقل عن خمس سنوات نصفهم من مدخني االركلية والنصف االخر غير 06عاما. تشمل 22و 22تتراوح اعمارهم بين شخص 06المواد والطرق: شملت الدراسة والمكان الجغرافي. تم قياس والجنس اسة في السنومطابقين لمجموعة الدر من غير المدخنينمدخنين )مدخنين سلبيين(. اما المجموعة االخيرة فهي المجموعة الضابطة والتي شملت عشرين طالبا حة العالمية وتم قياس صحة اللثة حسب مواصفات مؤشر اللثة ومؤشر الترسبات الكلسية الفموية كما وتم تقييم فقدان االلتصاق حسب مواصفات منظمة الص مؤشر الصفيحة الجرثومية لالسنان 1997. غير مدخنين )المدخنين السلبيين( ثم المجموعة الضابطة مع وجود العمال اليليها عمال المقاهي من المدخنين لالركيلةبين االعلى حات الجرثومية لالسنان لتكون النتائج: تم تسجيل القيم الوسطية للصفي يتعلق بفقدان اما فيما (p<0.001).مع وجود اختالفات معنوية عالية . كما تم الحصول على نتائج مماثلة فيما يتعلق بمؤشر اللثة ومؤشر الترسبات الكلسية(p<0.001)اختالفات معنوية عالية قيمة احصائية عالية بين مدخنين االركيلة والمجموعة الضابطة. ذوااللتصاق، لم يكن هناك اختالف االستنتاجات: خلصت هذه الدراسة الى ان تدخين االركيلة يرتبط سلبا مع صحة الفم وصحة اللثة http://www.joponline.org/author/ciancio%2c+sebastian+g mais.doc j bagh college dentistry vol. 26(4), december 2014 evaluation of marginal restorative dentistry 63 evaluation of marginal gap at the composite/enamel interface in class ii composite resin restoration by sem after thermal and mechanical load cycling (an in vitro comparative study) mais yaroub, b.d.s., m.sc. (1) mohammed r. hameed, b.d.s., m.sc., ph.d. (2) abstract background: this study compared in vitro the marginal adaptation of three different, low shrink, direct posterior composites filtek™ p60 (packable composite), filtek™ p90 (silorane-based composite) and sonic fill™ (nanohybrid composite) at three different composite/enamel interface regions (occlusal, proximal and gingival regions) of a standardized class ii mo cavity after thermal changes and mechanical load cycling by scanning electron microscopy. materials and methods:thirty six sound human maxillary first premolars of approximately comparable sizes were divided into three main groups of (12 teeth) in each according to the type of restorative material that was used: group (a) the teeth were restored with filtek™ p60 and single bond™ universal adhesive using horizontal incremental technique, group (b)the teeth were restored with filtek™ p90 and p90 system adhesive using horizontal incremental technique and group (c) the teeth were restored with sonic fill™ composite and single bond™ universal adhesive using bulk technique.after specimens were stored in distilled water at 37°c for 7 days, all specimens were subjected to thermocycling at (5° to 55 °c), then submitted to mechanical load cycling (intermittent axial force of 49n and a total of 50.000 cycles). the specimens were observed under scanning electron microscope at (2000 x) to measure marginal gap width (the distance between the dental wall and the restoration) at occlusal, proximal and gingival regions in micrometer using tescan software, version 3.5. data were analyzed statistically by one way anova test and least significant difference tests. results:the results showed that the silorane-based posterior composite (filtek™ p90) showed significantly the least marginal gap width at the occlusal, proximal and gingival regions after the application of thermal changes and mechanical load cycling in comparison to the two methacrylate-based posterior composite filtek™ p60 (packable) and the sonic fill™ (nano-hybrid). sonic fill™ bulk fill composite that relied on the vibration concept to lower the viscosity of high filler loaded composite material showed significantly lesser marginal gaps width at occlusal, proximal and gingival composite/enamel interface regions in comparison with filtek™ p60 (packable composite) using horizontal incremental technique. the silorane-based composite (filtek™ p90) showed non-significant difference in marginal gaps width at the three different regions. while, both methacrylate based filtek™ p60 and sonic fill™ composite showed significantly lesser marginal gap width at the occlusal region in comparison with gingival regions. conclusion: none of the low-shrinkage composite restorative materials tested in this study totally prevented microgap formation at composite/enamel interfaces of class ii mo cavity. key words: scanning electron microscope, marginal gap, filtek™p60, filtek™p90, sonic fill™. (j bagh coll dentistry 2014; 26(4):63-70). introduction the increasing demand for tooth colored restorations, cosmetic dental procedures, conservation of tooth structure together with dramatic advances in the field of adhesive technology has led to widespread placement of direct composite restorations(1). the application of composite resin to posterior teeth, especially in class ii restorations, may be compromised because of the inherent polymerization shrinkage and contraction stress that can cause de-bonding at the tooth-composite interface with an increased risk of gap formation, dentinal sensitivity and restoration failure (2). despite many new and innovative developments in the field of adhesives, a 100% perfect margin is not realistically achievable. (1) master student. department of conservative dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of conservative dentistry, college of dentistry, university of baghdad. composite materials undergo volumetric polymerization contraction of at least 2% which may result in gap formation as the composite pulls away from cavity margins during polymerization. a material's ability to seal a cavity preparation can be influenced by its composition, plastic deformation, flow, coefficient of thermal expansion, modulus of elasticity and the mechanical stresses caused by cavity shape (3).therefore a tight marginal seal still has to be the primary goal for the clinician, because once happened; gap formation cannot be counteracted with restorative materials that prevent demineralization along with cavity margins (4). in addition to stress shrinkage, the occlusal loads and alterations of the temperature of the oral behavior produce stress on the restoration and can also compromise the marginal sealing (5). in an attempt to solve problems related to polymerization shrinkage, a low-shrinkage j bagh college dentistry vol. 26(4), december 2014 evaluation of marginal restorative dentistry 64 composite material (filtek™ p90) based on a new resin chemistry with silorane monomers has been developed. filtek™ p60 packable composite introduced to market place as an alternative to amalgam. “packable” composites have higher filler loadings (> 80% by weight); therefore, they tend to feel stiffer than traditional composites and handle more like amalgam. the high filler content reduces the polymerization shrinkage. due to their packability, these composites help in restoring good contacts in posterior teeth. these stiffer materials may not adequately adapt to internal areas and cavosurface margins at the cervical joint (6). a novel resin composite system, sonic fill™ system (kerr/kavo), was recently introduced in the market. is indicated for use as a bulk fill posterior composite restorations and can be bulk filled in layers up to 5 mm in depth due to reduced polymerization shrinkage. sonic fill™ incorporates a highly-filled proprietary resin with special modifiers that react to sonic energy. as sonic energy is applied through the hand piece, the modifier causes the viscosity to drop (up to 87%), increasing the flow ability of the composite enabling quick placement and precise adaptation to the cavity walls. when the sonic energy is stopped, the composite returns to a more viscous, non-slumping state that is perfect for carving and contouring (7). the high quality of modern composite materials has made it more difficult to see changes in the quality of restoration margins, which in turn, has increased the need for more sensitive methods to assess the early changes of the marginal adaptation. scanning electron microscopy (sem) is a method that can be used for closer examination of the restoration margins because of its ability to magnify and reveal details (8). this study was conducted with aim of comparing in vitro the marginal adaptation performance of three different, low shrink, direct posterior composites. materials and methods teeth selection thirty six sound, human maxillary first premolar extracted as a part of an orthodontic treatment plan, were selected for use in this study. the teeth were cleaned with pumice and carefully rinsed with water to remove the residual debris. then the teeth were examined using a magnifying lens and by transilluminating fiber optic from a light curing unit for the presence of cracks. only intact teeth free of defects and of comparable size were selected and stored in distilled water at room temperature. cavity preparation to simulate the clinical situation during restoration placement, a dental manikin (maxilla) was used. maxillary canine and maxillary 2nd premolarwere included in a manikin, with a space between them to place the tested tooth. the three teeth were positioned with crowns in proximal contacts and long axis parallel to each other (9). all teeth received a standardized class ii mesio-occlusal (mo) cavity preparation. all cavities were prepared above cemento-enamel junction in order for all the cavity margins to be within enamel. the dimensions of the occlusal isthmus of the cavities were: bucco-palatally width (3 mm), occlusal depth (2 mm) measured from the cavosurface margin of the palatal cusp and (1.6 mm) thickness of remaining tooth structure was left during the extensions into distal marginal ridge. the dimensions of the proximal box were: buccao-palatally width (3 mm), height (2 mm) and (1.5 mm) depth axiallythe cavity preparation was made by using the parallel sided; flatended carbide fissure bur of 1 mm diameter with a high speed water-cooled hand piece that was fixed to the vertical arm of modified dental surveyor to standardize the cavity preparation.the width was checked using a point vernier caliper from different points of the prepared cavity while the depth was measured by graduated periodontal probe.a new bur was used for every four preparations to maintain cutting efficiency(10). samples grouping the teeth were randomly divided into three main groups (12 teeth in each group) according to the type of restorative material that was used. for all samples, three different composite/enamel interface regions were measured; occlusal region (assigned 1), proximal region (assigned 2) and gingival region (assigned 3). group a: the teeth were restored with filtek™ p60 (3m espe, usa) using horizontal incremental technique. group b: the teeth were restored with filtek™ p90 (3m espe, usa) using horizontal incremental technique. group c: the teeth were restored with sonic fill™ composite (kerr, usa) using bulk technique. restorative procedure each composite system was used according to the manufacturer's instructions with their j bagh college dentistry vol. 26(4), december 2014 evaluation of marginal restorative dentistry 65 corresponding adhesive systems. shade a3 was used for each composite type.after the cavity was prepared for each tooth, the cavity was dried using gentle air blast and a palodent sectional matrix system was placed.for group a and c a self-etch single bond™ universal adhesive (3m espe, germany) was used to bond the restorative material to the cavity walls. the bond was applied to the entire preparation’s walls using a disposable applicator and rubbed in for 20 seconds, followed by gentle air thinning over the liquid for about 5 seconds until it no longer moves, indicating complete vaporization of the solvent then light cured of the adhesive for 10 seconds using led light curing device. then filtek™ p60 composite resin was applied to the cavity of each tooth in group ausing horizontal incremental technique. two increments of 2 mm in thickness for each one were placed by the aid of plastic instrument for composite placement. each increment was light-cured for 20 seconds using a led light curing device. for group b, group, the teeth were restored with silorane-based (filtektm p90). filtek™p90 composite resin comes with a specially developed system adhesive (p90 system adhesive, 3m espe ag, germany) which consists of a self-etch primer and a bond. firstly, the self-etch primer was applied to the entire cavity for 15 seconds then dispersed with a stream of air and light-cured for 10 seconds by led light curing device. then, the bond was applied to the entire cavity, rubbed and lightcured for 10 seconds as for the primer. the restoration was built up using horizontal incremental technique with filtek™ p90 (3m espe, usa). two increments of 2 mm in thickness for each one were placed by the aid of plastic instrument for composite placement. each increment was light-cured for 40 seconds using a led light curing device. for group c,the sonic fill™ composite was placed using sonic fill™ handpiece (kavo, germany). the handpiece was attached to the multiflex coupling device (kavo, germany) that fit on air-water tube of dental chair. the sonic fill™ composite unidose capsule (kerr, usa) was screwed on the handpiece. the dispensing speed at the bottom of the handpiece was set at 3 (the medium speed). the unidose tip was placed at the deepest portion of the preparation to avoid trapping air. after the handpiece activation, sonic fill™ composite was placed in the cavity in a single, bulk increment then cured for 20 seconds from the occlusal surface by led light curing device. additional curing from the buccal and palatal aspects for 10 seconds each was done. thermocycling procedure thermocycling was done to simulate the temperature changes that take place in the oral cavity that might result in changes in the microspace between the tooth and the restoration.the procedure done by cycling the teeth between two water baths: one of the water baths maintained at 5°± 0.5°c and the other at 55°± 0.5°c, with a dwell time of 15 seconds. the number of cycles was 500 cycles according to the international organization for standardization (iso tr 11405) (11). teeth mounting to simulate periodontal ligament, the root surfaces were dipped into molten wax (dipping wax) up to 2.0 mm below the cemento-enamel junction using dipping wax machine. the tooth was dipped, resulting in a wax layer of 0.2 to 0.3 mm thickness (12). then all teeth were embedded along their long axis using a dental surveyor in mixed cold cure acrylic (at dough stage) 2.0 mm apical the cemento-enamel junction using a custom-made split metal mold (20 mm× 20 mm× 25 mm). after the first signs of polymerization, teeth were removed from the acrylic blocks and the wax was removed from root surfaces by using a surgical blade. a silicone-based light body impression material was injected into the acrylic resin blocks and the teeth were reinserted into the cubic acrylic blocks. a standardized silicone layer that simulated periodontal ligament was thus created taking the thickness of the wax layer (13). mechanical load cycling procedure a custom made apparatus was used for the cycling load. the design of the apparatus was consisted of stainless steel piston (25 mm diameter) with cylindrical arm and spherical end (2 mm diameter). the surface area of the piston equaled 4.9 cm2. a compressor delivered compressed air with pressure that was fixed at 1 bar. in order to achieve an axial force of 49 n, an air pressure of about 1 bar delivered to the piston through tubes every mechanical load cycle and according to the following equations: 1 bar = 1.01971 kg/cm2 (pressure unit) 1.01971 kg/cm2 × 4.9 cm2 (surface area of the piston) = 4.996579 kg ≅ 5 kg 1 kg = 9.8 n (newton unite) 5 kg × 9.8 m/s2= 49 n five kg was required to obtain an axial force of 49 n; also the axial force was verified by using an electronic load cell. the tip of the device (spherical end) was placed in contact with the center of the occlusal surface of the restoration. the loading device delivered an intermittent axial j bagh college dentistry vol. 26(4), december 2014 evaluation of marginal restorative dentistry 66 force of 49 n at a frequency of 2.5 hz. the samples were subjected to 50,000 cycles (corresponding to 5.5 hours in the machine) (14). specimens' preparation for sem investigation all the specimens were sectioned horizontally with the level of cemento-enamel junction with a water cooled diamond disc to separate the crowns from the roots and the crowns were kept for sem examination. the samples were placed on aluminum stubs with the help of an adhesive material and a carbon paste was placed on a side of the sample to be act as an electrical conductor then the stubs were fixed on sem standard specimen holder. the holder was placed on a stage in a sputtering coater device (spc-12 compact plasma sputtering coater, usa) for 10 sec. to coat the samples with gold. the holder was screwed on the specimen chamber mounting table of sem. evaluation of marginal adaptation all the samples were examined by tescan sem at 2000x magnification to detect marginal gaps along the composite/enamel interfaces at occlusal, proximal and gingival regions (13). the measurement of marginal gap width (the distance between the dental wall and the restoration) in each sample were taken at: three points in the gingival region, six points at the proximal region (3 points in buccal side and 3 points in palatal side) and nine points at the occlusal region (3 points in buccal side, 3 points in palatal side and 3 points in distal side) (figure 1).the largest marginal gap width from the three points in each side of the region was recorded in micrometers (μm) by tescan image processing software (atlas software, version 3.5, germany) (5). figure 1: the location of the points (●) in each region. results the data were collected and analyzed using spss (version 20) for statistical analysis. for the occlusal region, the mean of three points from the buccal, palatal and distal sides that represent the largest marginal gaps width of occlusal region was taken, for the proximal region, the mean of two points from the buccal and palatal sides that represent the largest marginal gaps width of proximal region was taken and the point that represent the largest marginal gap width at the gingival region was taken for each sample (figure 2). figure 2: the largest tooth (t)/restoration (r) marginal gaps width at gingival region's point of sample restored with afiltek™p60. bfiltek™p90. csonic fill™. the mean, standard deviation, minimum and maximum values (descriptive statistics) for marginal gaps width in (µm) at the occlusal, proximal and gingival regions for the three different composite materials are summarized in (table 1). the comparison between the three composite materials in marginal gaps width (µm) at each region by one-way anova test revealed a statistically highly significant differences among all groups of this study (p ≤ 0.01) as shown in (table 2). j bagh college dentistry vol. 26(4), december 2014 evaluation of marginal restorative dentistry 67 table 1: means, standard deviations, minimum and maximum values for marginal gaps width (µm) at the occlusal, proximal and gingival regions for all composite materials. materials groups regions descriptive statistics mean ±sd min. max. group (a) a1 12.34 1.06 10.75 13.89 a2 13.33 1.30 11.25 15.64 a3 14.18 1.58 12.44 17.93 group (b) b1 3.24 0.66 1.92 3.96 b2 3.01 0.68 1.99 3.98 b3 3.54 0.63 2.3 4.52 group (c) c1 4.88 0.95 3.46 6 c2 5.61 1.27 4.05 7.57 c3 6.69 1.18 5.05 8.6 table 2: anova test for the marginal gaps width (µm) among the three composite materials at each region regions anova sum of squares df mean square f-test p-value (occlusal) a1 between groups 564.539 2 282.270 345.409 0.000 hs b1 within groups 26.968 33 0.817 c1 total 591.507 35 (proximal) a2 between groups 691.547 2 345.774 275.289 0.000 hs b2 within groups 41.449 33 1.256 c2 total 732.996 35 (gingival) a3 between groups 715.750 2 357.875 249.300 0.000 hs b3 within groups 47.372 33 1.436 c3 total 763.122 35 further comparisons between groups by lsd test revealed a statistically highly significant difference in marginal gaps width when comparing group a with group b and c. while, group bshowed statistically significant less marginal gap width than group c at occlusal, proximal and gingival regions (table 3) table 3: lsd test for the marginal gaps width (µm) among the three composite materials at each region regions mean difference p-value occlusal a1 b1 9.098 0.000 hs c1 7.462 0.000 hs b1 c1 -1.637 0.000 hs proximal a2 b2 10.322 0.000 hs c2 7.718 0.000 hs b2 c2 -2.603 0.000 hs gingival a3 b3 10.632 0.000 hs c3 7.483 0.000 hs b3 c3 -3.149 0.000 hs the comparison of marginal gaps width (µm) at occlusal, proximal and gingival regions within each composite material by one-way anova test revealed a statistically highly significant difference for groupsa and c. while, for group b there was no significant difference for the marginal gaps width (µm) among the three tested regions (table 4). j bagh college dentistry vol. 26(4), december 2014 evaluation of marginal restorative dentistry 68 table 4: anova test for marginal gaps width (µm) at three different regions within each composite material further comparisons by lsd test was performed for the three different regions within each group a and group c and the result showed that, the group a1 has no statistical significant difference than group a2, while the group a1 has highly statistical significant difference as compared with group a3. also the result showed that, the group a2 has no statistical significant difference as compared with group a3.lsd test for comparison between group c1, c2 and c3 showed that, the group c1 has highly statistical significant difference as compared with group c3 and no statistical significant difference as compared with group c2, while the result showed that the group c2 has statistical less significant difference as compared with group c3 (table 5). table 5: lsd test for marginal gaps width (µm) at three different regions for group (a) and group (c) materials groups regions mean difference p-value group a a1 a2 -0.992 0.077 ns a3 -1.838 0.002 hs a2 a3 -0.847 0.128 ns group c c1 c2 -0.735 0.125 ns c3 -1.818 0.000 hs c2 c3 -1.083 0.027 s discussion the polymerization of composite resin results in a reduction in the intermolecular distance between the monomers and consequential shrinkage. bonding the composite resin to the cavity walls impairs the material deformation and generates shrinkage stress on the bonding interfaces. if stress exceeds the bond strength between the dental substrate and the adhesive system, a contraction gap will be formed, jeopardizing the restoration's longevity (15,16). in this study, filtek™ p90 composite material that tested exhibited statistically the highly significant decrease in marginal gaps width along the composite/enamel interface at the occlusal, proximal and gingival regions after thermomechanical load cycling as compared with sonicfill™ composite and filtek™ p60 composite resins. this could be attributed to: 1-the difference in chemical composition of the matrix system, the inherent ring-opening polymerization of oxirane moieties in the silorane monomer of filtek™ p90 composite resin starts with the cleavage and opening of the ring mechanism which helps in gaining space and counteracts the loss of volume which occurs in the subsequent step, when the chemical bonds are formed manifested as a reduction in polymerization shrinkage stress at the tooth/restoration interface as compared to the linear polymerization of the methacrylate-based sonicfill™ and filtek™ p60 composite resins(17). 2it is also hypothesized that since silorane technology provides lower polymerization shrinkage and related polymerization stress than methacrylate-based composite resins. it should be able to withstand thermo-mechanical cycling fatigue at the tooth/restoration interface better than the methacrylate-based composite resins. this finding agrees with studies of palin et al. (18); yamazaki et al. (19); bagis et al. 2009 (20) and borges et al. (10). they showed that the percentage of gaps in the siloranes samples did not increase significantly after thermal and mechanical cycling but in the methacrylates this difference was significant. materials groups anova sum of squares df mean square f-test p-value (a) a1 between groups 20.319 2 10.159 5.745 0.007 hs a2 within groups 58.362 33 1.769 a3 total 78.681 35 (b) b1 between groups 1.739 2 0.869 2.001 0.151 ns b2 within groups 14.341 33 0.435 b3 total 16.080 35 (c) c1 between groups 20.061 2 10.031 7.683 0.002 hs c2 within groups 43.086 33 1.306 c3 total 63.147 35 j bagh college dentistry vol. 26(4), december 2014 evaluation of marginal restorative dentistry 69 3-the type of adhesive system used plays an important role in reduction the shrinkage stress and avoiding initial marginal gaps. the two-step, self-etch filtek™ p90 system adhesive (6thgeneration) used with filtek™ p90 composite resin produce higher bond strengths to both enamel/dentin and exhibit better marginal sealing than one-step, self-etch single bond™ universal adhesive (7th generation) used with filtek™ p60 and sonic fill™ (21). on the other hand, the sonic fill™ composite resin exhibited the highly significant decrease in marginal gaps width along the composite/enamel interface at the occlusal, proximal and gingival regions as compared with filtek™ p60 composite. this could be attributed to the increase in the amount of filler particles and a consequent increasing in the viscosity of the filtek™ p60 composite resin, leading to an inadequate adaptation to the enamel walls. the packable composites have insufficient matrix available for wetting the cavity wall and melting of the subsequent layers leading to creation of voids within the restoration or at the cavo-surface margin (6,17). the sonic fill™ composite relied on the concept of sonic vibration which assumed that vibration lowers the viscosity of the composite resin, allowing the material to flow and possess a good wetting ability, which favors their adaptation to the cavity walls, and therefore expected to decrease the risk for air entrapment and void inclusion, in a similar way as a flowable composite, this finding agrees with study of (yap and powers in 2011)(22) who showed that although material consistency does not equal that of a flowable composite, vibration secures an adaptation to the cavity walls similar to that obtained with a composite flow. from the result of this study, the marginal adaptation of filtek™ p90 as tested by sem along the composite/tooth interface was found that no statistical significant differences between occlusal, proximal and gingival regions. this is possibly related to the low-shrinking behavior of silorane resin and the fact that at gingival margin, low polymerization contraction stress cannot overcome the bond strength (23). while, in both methacrylate-based filtek™ p60 and sonic fill™ composite resins a highly significant increase marginal gap width at the gingival region as compared with occlusal region. the inadequate marginal adaptation at the gingival margin of both methacrylate-based composite resins may be due to: 1-the shrinkage of resin composite towards the light source because the composite closer to the light hardens first. this, in turn, pulls the softer composite resin from the gingival areas creating a gap. contraction towards the light source causes the resin to shrink from margins of the preparation, even when resin is applied and cured in small increments (24). 2-another possible explanation may be due to lesser thickness of enamel at the cavo-surface margin of the proximal aspect which requires adhesion of the restorative materials to greater proportion of dentin; a less reliable, more complex substrate than enamel (25). 3-the distance of light source from the material which is higher at the proximal box base as compared to occlusal surfaces. the distance from the light curing tip alters the irradiance of the light-cure device which reaches the composite resin, reducing the percentage of degree of conversion.low degree of monomer conversion might cause unconverted double bonds, making the resin more susceptible to degradation by premature breakdown at the tooth-restoration interface (26). as conclusions; 1. the silorane-based posterior composite (filtek™ p90) showed the least marginal gap width at the occlusal, proximal and gingival regions in comparison to the two methacrylate-based posterior composite filtek™ p60 and the sonic fill™ . while, sonic fill™ bulk fill composite that relied on the vibration concept to lower the viscosity of high filler loaded composite material showed lesser marginal gaps widthin comparison with filtek™ p60 (packable composite) using horizontal incremental technique after the application of thermal changes and mechanical load cycling when the tooth/restoration interface is located in enamel. 2. the silorane-based composite (filtek™ p90) showed non-significant difference in marginal gaps width at the three different regions. while, both methacrylate based filtek™ p60 and sonic fill™ composite showed significantly lesser marginal gap width at the occlusal regions in comparison with gingival regions of class ii composite restorations. references 1. nadig rr, bugalia a, usha g, karthik j, rao r, vedhavathi b. effect of four different placement techniques on marginal microleakage in class ii composite restorations: an in vitro study. world j dent 2011; 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13: 9-15. 7. eunice c, margarida a, joão cl, filomena b, anabela p, pedro a, miguel mc, diana r, joana m, mário p, marques fm. 99mtc in the evaluation of microleakage of composite resin restorations with sonicfill™. an in vitro experimental model. oper dent 2012; 2: 340-7. 8. schmidt m, horsted-bindselv p, poulsen s, nyengaard jr. marginal adaptation of a low-shrinkage silorane-based composite: a sem-analysis. j braz oral res 2012; 116(10): 736-42. 9. sabah mk. marginal leakage of amalgam and modern composite materials related to restorative techniques in class ii cavity: a comparative study. a master thesis, college of dentistry, university of baghdad 2013. 10. borges as, santos jd, romos cm, ishikiriama sk, shinohara ms. effect of thermo-mechanical load cycling on silorane-based composite restorations. dent mater. 2012; 31(6): 1054-9. 11. loguercio ad, bauer jrd, reis a, grande rhm. in vitro microleakage of packable composites in class ii restorations. restor dent 2004; 35(1): 29-34. 12. soares cj, pizi ecg, fonseca rb, martins lrm. influence of root embedment material and periodontal ligament simulation on fracture resistance tests. braz oral res 2005; 19(1): 11-6. 13. zarrati s, mahboub f. marginal adaptation of indirect composite, glass-ceramic inlays and direct composite: an in vitro evaluation. tehran j dent 2010; 7(2): 7783. 14. paula ab, duque c, correr-sobrinho l, puppinrontani rm. effect of restorative technique and thermal/mechanical treatment on marginal adaptation and compressive strength of esthetic restorations. oper dent 2008; 33(4): 434-40. 15. papadogiannis d, kakaboura a, palaghias g, eliades g. setting characteristics and cavity adaptation of lowshrinking resin composites. dent mater 2009; 25:1509-16. 16. rodrigues sa jr, pin lf, machado g, della bona a, demarco ff. influence of different restorative techniques on the marginal seal of class ii composite restorations. j appl oral sci 2010; 18: 37-43. 17. majeed ma. microleakage evaluation of siloranebased and methacrylate-based packable and nanofill posterior composites (in vitro comparative). j tikrit dent sci 2012; 2(1): 19-26. 18. palin wm, fleming gj, nalhwani h, burke fj, randall rc. in vitro cuspal deflection and microleakage of maxillary premolars restored with novel low-shrink dental composites. dent mater 2005; 21: 324-35. 19. yamazaki pc, bedran-russo ak, pereira pn, wsift ej jr. microleakage evaluation of a new lowshrinkage composite restorative material. oper dent 2006; 31:670-6. 20. bagis yh, baltacioglu ih, kahyaogullari s. comparing microleakage and the layering methods of silorane-based resin composite in wide class ii mod cavities. oper dent 2009; 34(5): 578–85. 21. ulker m, ozcan m, sengun a. effect of artificial aging regimens on the performance of self-etching adhesives. j biomed mater res part b: appl biomater 2010; 93(1):175-84. 22. yap p, powers jm. depth of cure of several composite restorative materials. dent advis res report 2011; 33: 1. 23. ghulman ma. effect of cavity configuration (c factor) on the marginal adaptation of low-shrinking composite: a comparative vivo study. int j dent 2011; 61-6. 24. johar k. fundamentals of laser dentistry. 1st ed. india: jaypee brothers, 2011; ch5: 45-53. 25. bogra p, s gupta s, kumar s. comparative evaluation of microleakage in class ii cavities restored with ceram x and filtek p-90: an in vitro study. contemp clin dent 2012; 3(1): 9-14. 26. coutinho m, trevizam nc, takayassu rn, leme aa, soares gp. distance and protective barrier effects on the composite resin degree of conversion. j contempclin dent 2013; 4(2): 152–5. journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 45 research article evaluation of leukocytes cells types counts in blood from patients with different severities of periodontal diseases chinar jabbar ali 1, nada kadhim imran 2*, maha abdul aziz ahmed 3 1. ministry of health, kirkuk, iraq 2. department of periodontics, college of dentistry, university of baghdad 3. department of periodontics, college of dentistry, university of baghdad * correspondence email; nada.k.omran@codental.uobaghdad.edu.iq abstract: background: periodontal diseases are inflammatory disorders caused by the accumulation of oral biofilm and the host response to this accumulation which characterized by exaggerated leukocytes and neutrophils attraction to the sites of inflammation by chemoattractants which are a very important part of the pathogenesis of periodontal diseases. this study aimed to determine and compare the clinical periodontal parameters and the leukocyte cell types in the peripheral blood between patients with gingivitis and periodontitis with different severities compared to healthy controls. materials and methods: this study included 150 male subjects aged between 35-50 years. they were divided into three groups: gingivitis group (n=30), periodontitis patients (n=90) which subdivided into mild =30 patients, moderate =30 patients, severe =30 patients and a control group (n=30) with clinically healthy periodontium. clinical periodontal parameters were recorded ((plaque index (pli), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd) and clinical attachment level (cal)). blood samples were collected then an automated blood analyzer evaluated leukocyte cell types. results: significant differences in the counts of neutrophils and lymphocytes exhibited significant differences among the study groups and subgroups. on contrary, differences in monocytes, eosinophils, and basophils counts were not significant. additionally, severity of periosontitis was significantly correlated with the mean counts of the various leukocyte cell types; however, clinical periodontal characteristics did not show such correlation with these inflammatory cells. conclusion: this study demonstrated that periodontal disease with different severities is associated with possible episodes of bacteremia that originate from periodontal lesions which mediate inflammatory conditions that in turn causing changes in the systemic markers especially leukocytes cells types. keywords: leukocytes, neutrophils, periodontal diseases. introduction: the inflammation develops in the oral tissues as long as plaque accumulates along the gingival margin. the inflammation may lead to either gingivitis, which remains localized coronally to the junctional epithelium, or to periodontitis, which extends deeper leading to loss of connective tissue attachment and the supporting bone. this devastating destruction is either due to the direct toxic effect of gram-negative bacteria mainly porphyromonasgingivalis, aggregatibacter actinomycetemcomitans and tannerella forsythia or the host’s response to potent periodontopatogens mediated first by the polymorphonuclear leukocytes (pmns) and subsequently by the cells of the reticulo-endothelial system i.e., monocytes and macrophages. received date: 15-03-2022 accepted date: 04-05-2022 published date: 15-06-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/lic enses/by/4.0/). https://doi.org/10.26477/j bcd.v35i2.3402 https://orcid.org/0000-0003-2221-0546 https://orcid.org/0000-0002-5651-5084 https://orcid.org/0000-0002-1658-4210 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3402 https://doi.org/10.26477/jbcd.v35i2.3402 j. bagh. coll. dent. vol. 35, no. 2. 2023 chinar et al. 46 indeed, in periodontitis, excessive production of pro-inflammatory cytokines and acute-phase reactants such c-reactive protein in reponse to bacteria is the hallmark of the host’s immune system (1). leukocytes include five morphologically and functionally distinct types of nucleated blood cells: neutrophils, eosinophils, basophils, monocytes, and lymphocytes. the leukocytes are attracted to sites of inflammation, infection, or tissue injury by chemoattractant and leave the circulation using special adhesion molecules and ligands located on the leukocytes and endothelial cells of the vessel walls. leukocytes are the major systemic cells of phagocytosis and the first cells of the host defense mechanism against infective agents. during periodontitis, neutrophils are initially predominant cells of the host defense mechanism and have a significant role in inflammation and pathogenesis. it is supposed that there is an increase in the count of these cells in periodontitis of various severities due to the accumulation of the oral biofilm when compared to healthy subjects, loos et al. (2) and loos et al. (3) showed high levels of neutrophils and lymphocytes in patients with periodontitis as compared to subjects with healthy periodontium. periodontal inflammation can deteriorate systemic conditions through the pathology caused by leukocytes (4). this study aimed to assess the leukocyte cell type counts in the peripheral blood of patients suffering from different severities of periodontal diseases. materials and methods: this case-control study involved 150 males aged between 35 to 50 years who were recruited from the patients who attended to department of periodontics, college of dentistry, university of baghdad as well as from the blood bank in baghdad in the period from december 2016 to april 2017. the patients were divided into three groups: the 1st group consisted of 30 patients with generalized gingivitis and the 2nd group included 90 patients with periodontitis that subdivided according to the severity of clinical attachment loss where mild 1-2 mm, moderate 3-4 mm and severe ≥5 mm (5) (30 patients /group) and a control group (n=30) with clinically healthy periodontium. inclusion criteria: 1. systemically healthy subjects with ≥ 20 teeth present. 2. all teeth except third molars included in this study and according to the international classification system for periodontal disease (6) , the periodontitis group must have at least four sites with probing pocket depth of ≥4 mm and clinical attachment loss of 1-2 mm or more. 3. in gingivitis group, the patients are characterized by signs and symptoms of gingival inflammation (7), but without any true periodontal pockets or clinical attachment loss. in contrast, patients with clinically healthy periodontai tissues were characterized by the absence of any signs and symptoms of any inflammation, periodontal pockets and clinical attachment loss. exclusion criteria: 1. females 2. smokers 3. alcohol drinkers 4. patients underwent periodontal therapy and/or were consuming antiinflammatory/antibacterial drugs, or any other medications in the last 3 months prior to the study. 5. patients with history of any systemic diseases. j. bagh. coll. dent. vol. 35, no. 2. 2023 chinar et al. 47 full medical and dental histories were taken from all subjects and written consent was obtained. clinical periodontal parameters were assessed using marquis periodontal probe, which included: pli (8), gi (7), bop and ppd (9) and cal (5). four sites per tooth (mesial, buccal/ labial, distal and lingual/ palatal) were examined. after collecting 2.5 ml of blood into an ethylene diamine tetra acetic acid tube, leukocyte cell types (neutrophils, eosinophils, basophils, monocytes, and lymphocytes) were evaluated by an automated blood analyzer. this study was following the revised helsinki declaration and it has been approved by the relevant institutional ethical committee (10). statistical analysis the descriptive statistics used in this study to express clinical parameters and cell counts were the mean and standard deviation (s.d.). before conducting the inferential analyses, the distribution of data was checked by the shapiro-wiliks test. then multigroup comparisons were performed by analysis of variance (anova) test followed by least significant difference (lsd) posthoc test. pearson's correlation test determined the correlation between cell counts and clinical parameters. significant differences were determined when p value was less than 0.5. results: there were significant differences appeared among groups and subgroups in pli, gi, bop score 1, ppd and cal (table 1). the comparisons of the mean values of the clinical periodontal parameters between all pairs of the gingivitis group and periodontitis subgroups are shown in table (2). data shown table (3) indicated that neutrophils and lymphocytes displayed statistically significant variations among groups and subgroups, whereas basophils, eosinophils and monocytes did not. mild periodontitis had the greatest mean neutrophil value, while the control group had the lowest value. the gingivitis group had the lowest mean lymphocyte value, while the mild periodontitis group had the greatest count. additionally, severe versus moderate periodontitis groups showed the greatest mean value of monocytes as compared to other groups. for eosinophils, the control group had the lowest mean value of, whereas the mild periodontitis subgroup had the highest mean value. in contrast to the control group, which displayed the lowest mean value, severe periodontitis demonstrated the highest mean value of basophils. the neutrophil cells count mean values were non-significant except for the significant differences between the control group with the gingivitis group, mild and severe periodontitis subgroups together with mild with moderate periodontitis subgroups. lymphocyte cells' mean values demonstrated non-significant differences except for the significant differences between moderate periodontitis and control and gingivitis groups. monocyte cells' mean values showed non-significant differences except the significant difference between mild with severe periodontitis subgroups (table 4). the correlation between leukocyte cell types and the clinical periodontal parameters was non-significant (table 5). however, neutrophils correlations were significantly positive for gi in the gingivitis group, as well as highly significantly negative for bop score one and positive for cal with moderate periodontitis. in contrast, lymphocytes revealed a significant strong positive correlation with ppd in the severe periodontitis subgroup only. monocyte count demonstrated a significant moderate negative correlation with pli in the moderate periodontitis subgroup. eosinophils showed non-significant correlations with all clinical periodontal parameters in all gingivitis and periodontitis subgroups. the results of basophils revealed a significant moderate positive correlation with gi in the severe periodontitis subgroup. j. bagh. coll. dent. vol. 35, no. 2. 2023 chinar et al. 48 table 1: statistical analysis of clinical periodontal parameters for cp subgroups, gingivitis and control groups: table 2: comparisons of the mean values of the clinical periodontal parameters between all pairs of cp subgroups and the gingivitis group by using the lsd test: groups and subgroups pl i gi bop score 1 ppd cal mean ±s.d. mean ±s.d. mean ±s.d. mean ±s.d. mean ±s.d. control 0.21 0.09 0.106 0.035 gingivitis 1.51 0.57 1.116 0.179 8.90 3.30 mild cp 1.87 0.49 1.370 0.364 22.9 10.76 4.93 0.99 1.68 0.204 moderate cp 1.95 0.40 1.625 0.429 34.1 10.86 5.33 1.31 3.57 0.291 severe cp 2.10 0.24 1.872 0.383 49.1 10.42 5.66 1.24 6.36 0.641 f-test without control group 111.761 484.212 83.782 24.88 928.703 p-value 0.000 0.000 0.000 0.000 0.000 cal ppd bop score 1 gi pli p value mean difference p value mean difference p value mean difference p value mean difference p value mean difference group and subgroups 0.000 -14.00 0.000 -0.307 0.000 -0.367 mild p gingivitis 0.000 -25.23 0.000 -0.550 0.000 -0.438 moderate p 0.000 -40.28 0.000 -0.778 0.000 -0.590 severe p 0.000 -1.89 0.001 -0.40 0.000 -11.23 0.000 -0.242 0.495 -0.071 moderate p mild p 0.000 -4.68 0.000 -0.73 0.000 -26.27 0.000 -0.470 0.033 -0.222 severe p 0.000 -2.79 0.001 -0.33 0.000 -15.04 0.000 -0.228 0.146 -0.151 severe p moderate p j. bagh. coll. dent. vol. 35, no. 2. 2023 chinar et al. 49 table 3: statistical analysis of neutrophils, lymphocytes, monocytes, eosinophils and basophils cells count (no. of cells ×109/l) for cp subgroups, gingivitis and control groups by using analysis variance test: groups and subgroups neutrophils lymphocytes monocytes eosinophils basophils mean ±s. d. mean ±s.d. mean ±s.d . mean ±s.d. mea n ±s.d. control 3.67 0.98 2.26 0.584 0.423 0.152 0.197 0.016 0.056 0.025 gingivitis 4.56 1.58 2.22 0.592 0.471 0.175 0.201 0.013 0.065 0.029 mild cp 4.91 2.12 2.36 0.531 0.406 0.165 0.210 0.013 0.067 0.025 moderate cp 4.04 1.03 2.67 0.761 0.466 0.164 0.216 0.012 0.063 0.036 severe cp 4.50 1.23 2.50 0.691 0.495 0.191 0.205 0.011 0.068 0.023 f-test 2.978 2.580 1.533 0.136 0.620 p-value 0.021 0.040 0.196 0.969 0.649 table 4: comparisons of mean values of count parameter between all pairs of groups and subgroups neutrophil cells groups and subgroups mean difference p-value sig. control gingivitis -0.824 0.029 s mild cp -1.170 0.002 s moderate cp -0.304 0.422 ns severe cp -0.766 0.044 s gingivitis mild cp -0.345 0.359 ns moderate cp 0.520 0.168 ns severe cp 0.058 0.877 ns mild cp moderate cp 0.865 0.024 s severe cp 0.403 0.288 ns moderate cp severe cp -0.462 0.224 ns lymphocyte cells groups and subgroups mean difference p-value sig. control gingivitis 0.0470 0.774 ns mild cp -0.092 0.574 ns moderate cp -0.409 0.014 s severe cp -0.235 0.154 ns gingivitis mild cp -0.139 0.394 ns moderate cp -0.456 0.006 s severe cp -0.282 0.085 ns mild cp moderate cp -0.317 0.056 ns severe cp -0.143 0.386 ns moderate cp severe cp 0.174 0.292 ns j. bagh. coll. dent. vol. 35, no. 2. 2023 chinar et al. 50 table 5: correlation between (leukocytes cells count with the clinical periodontal parameters of the gingivitis group and cp subgroups (person’s correlation coefficient: neutrophils pli gi bop score 1 ppd cal r p r p r p r p r p gingivitis 0.097 0.604 0.376 0.037 -0.161 0.388 mild cp 0.038 0.841 0.155 0.412 0.151 0.427 -0.034 0.949 0.022 0.907 moderate cp -0.104 0.586 -0.137 0.471 -0.492 0.006 0.381 0.457 0.399 0.002 severe cp 0.140 0.460 0.054 0.777 0.041 0.829 -0.517 0.190 -0.166 0.382 lymphocytes pli gi bop score 1 ppd cal r p r p r p r p r p gingivitis 0.031 0.870 -0.295 0.107 0.197 0.287 mild cp 0.083 0.663 0.067 0.726 -0.118 0.535 0.256 0.625 -0.178 0.348 moderate cp -0.231 0.218 -0.083 0.661 -0.167 0.377 0.078 0.884 0.062 0.743 severe cp -0.184 0.330 -0.132 0.486 -0.225 0.232 0.690 0.058 0.005 0.977 monocytes pli gi bop score1 ppd cal r p r p r p r p r p gingivitis -0.031 0.868 0.024 0.898 0.008 0.964 mild cp 0.106 0.579 0.007 0.970 -0.003 0.986 -0.691 0.128 -0.002 0.992 moderate cp 0.416 0.022 0.023 0.904 -0.331 0.074 0.300 0.564 0.111 0.558 severe cp 0.130 0.494 0.140 0.460 0.056 0.768 -0.308 0.457 -0.150 0.429 eosinophils pli gi bop score1 ppd cal r p r p r p r p r p gingivitis -0.054 0.773 -0.186 0.316 0.187 0.313 mild cp 0.195 0.301 0.124 0.513 0.103 0.587 -0.505 0.307 -0.112 0.554 moderate cp -0.295 0.114 0.016 0.935 -0.213 0.258 -0.086 0.872 -0.014 0.943 severe cp 0.102 0.591 -0.039 0.839 0.067 0.725 0.001 0.998 -0.225 0.233 basophils pli gi bop score1 ppd cal r p r p r p r p r p gingivitis 0.301 0.100 -0.066 0.722 0.126 0.499 mild cp 0.002 0.992 -0.004 0.982 0.266 0.155 -0.428 0.397 -0.065 0.731 moderate cp -0.184 0.331 0.051 0.788 -0.102 0.590 0.033 0.951 0.117 0.539 severe cp 0.291 0.119 0.443 0.014 0.303 0.104 -0.384 0.348 -0.292 0.117 monocyte cells groups and subgroups mean difference p-value sig. control gingivitis -0.055 0.201 ns mild cp 0.009 0.823 ns moderate cp -0.050 0.249 ns severe cp -0.079 0.070 ns gingivitis mild cp 0.065 0.136 ns moderate cp 0.005 0.906 ns severe cp -0.023 0.585 ns mild cp moderate cp -0.060 0.173 ns severe cp -0.089 0.044 s moderate cp severe cp -0.029 0.510 ns j. bagh. coll. dent. vol. 35, no. 2. 2023 chinar et al. 51 discussion: according to the available literature (4,11) , the clinical periodontal indices (pli, gi, bop score 1, ppd, and cal) showed extremely significant variations between groups and periodontitis subgroups. when oral hygiene is neglected and dental plaque builds up, it causes periodontal disease. this condition is the end result of a host immune-inflammatory reaction that interacts with dental plaque bacteria to cause the destruction of periodontal ligament fibers, which causes clinical loss of attachment and resorption of the alveolar bone (9). significant variations in the neutrophils were seen between the various groups and subgroups of periodontitis. these results coincide with previous studies (1-2, 12-14). periods of bacteremia in periodontitis or lipopolysaccharide leakage to the systemic circulation result in greater amounts of neutrophil discharge since they are the first line of defense in the innate immune system (15). according to other investigations (2,3,12,14,16,17), lymphocytes demonstrated considerable variations between groups and periodontitis subgroups, but disagrees with other studies (4,13). when the severity of periodontal disease has been increased, there were increased numbers of neutrophils in the connective tissue and the appearance of macrophages, lymphocytes, plasma cells and mast cells. the metabolic products of bacteria trigger junctional epithelium cells to produce cytokines, causing vasodilatation of local blood vessels, and permitting the gradual migration of macrophages, plasma cells, and t and b lymphocytes from the capillaries that become the principal cells (18). consequently, activated inflammatory response and the continued presence of bacterial plaque, the destruction in the periodontal ligament and bone resorption can be noticed clinically (9). the count of monocytes, eosinophils, and basophils demonstrated non-significant differences among the groups and periodontitis subgroups. however, there was an increase in the mean cell counts with the severity of the periodontal disease. the elevated leukocyte numbers in periodontitis and experimental gingivitis have been proposed to be mainly due to the elevation in neutrophil numbers (15). since the normal percentage ranges of white blood cells types are; neutrophils: 54% to 62%, lymphocytes: 25% to 33%, monocytes: 3% to 9%, eosinophils:1% to 3% basophils: less than 1% (19). systemic infections or conditions must be severe to affect these cells but periodontal diseases are mild inflammatory conditions showed little impact on their counts (20,21). therefore, periodontal inflammation could be mild that not significantly affect the counts of cells that are present in small percentages. results of monocyte counts agree with other studies (12,13), but disagree with patil (1). the eosinophils results coincide with previous studies (12,1,13) while the results of basophils were consistent with other findings (12,13). local inflammatory response developed with the incidence of sub gingival pathogens which is characterized by a large number of leukocyte exudation and migration from the systemic circulation to the affected site that is involved in the first line of defense against bacterial pathogens. in addition, this inflammatory response is augmented as a result of pro-inflammatory cytokines and prostaglandins production which are formed by a variety of cells as a response to the microbial invasion such as monocytes/macrophages, neutrophils, lymphocytes, adipocytes and fibroblasts. recruitment of more proinflammatory mediators and leukocytes to the site of infection as a result of their release in the bloodstream (12). basophils numbers revealed moderate correlations with gi and ppd in periodontitis patients while eosinophils demonstrated a moderate negative correlation with ppd at mild periodontitis. during infection and inflammation, there is an increase in total leukocyte count which is crucial in this context (22). the periodontal lesions cause bacteremia that changes the systemic markers in the body as the disease progress and there will be an area of ulceration in the epithelial lining of the periodontal pocket that enables greater changes and stimulation of the host response to the bacterial product as manifested by an increased inflammatory response in the form of elevated total leukocyte counts (4). in general, there is a scarcity of j. bagh. coll. dent. vol. 35, no. 2. 2023 chinar et al. 52 researches that link the circulatory inflammatory cells with periodontitis which was emphasized in the current investigation. conclusions: sequalae of periodontal diseases with different severities are not restricted to the periodontal tissue only. still, they also cause inflammatory states systemically influencing the counts of leukocyte cell types specially neutrophils and lymphocytes. conflict of interest: none. references: 1. patil r. evaluation of haematological changes in patients with chronic periodontitis and gingivitis in comparison to healthy controls – a clinical study. j dent allied sci 2013;2(2):49-53. 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(crossref) 22. rudin sr, laboratory tests and their significance, in: walter h (eds.), critical decisions in periodontology, pmph usa, london, 2013: 4-6. شدة مختلفة من امراض اللثة منتقييم أنواع خاليا كريات الدم البيض في دم المرضى الذين يعانون : العنوان جنار جبار علي , ندى كاظم عمران, مها عبدالعزيز احمد الباحثون: : المستخلص ذا التراكم والتي تتميز بتضخم الكريات البيض والعدالت في مناطق االلتهاب هأضطرابات التهابية ناتجة عن تراكم االغشية الحيوية الفموية واستجابة العائل لهي أمراض اللثة أنواع خاليا وفي التسبب في امراض اللثة . كان الهدف من هذه الدراسة هو تحديد ومقارنة المتغيرات السريرية اللثوية جزًءا مهًما جدًا بواسطة المعالج الكيميائي والتي تعد ( من الذكور تتراوح 150شملت هذه الدراسة ) محيطي بين مرضى ألتهاب اللثة وألتهاب دواعم السن بدرجات مختلفة مقارنة بالضوابط الصحية. الكريات البيض في الدم ال 30لى معتدلة = ( والتي قسمت ا90 = )ن (, مرضى ألتهاب دواعم السن30 = )ن و تم تقسيمهم الى ثالث مجموعات: مجموعة ألتهاب اللثة ( سنة50-35أعمارهم بين ) ، ( gi) ، مؤشر اللثة ( pli)) مؤشر البالك ) ( . تم تسجيل معامالت اللثة السريرية30و مجموعة أساسية )ن = مريضاً 30= شديدة, مريضاً 30متوسطة = ,مريضاً طريق محلل الدم اآللي و أظهرت المقارنات بين المجموعات تم تقييمها عن و ((cal)ومستوى التعلق السريري ( ppd)، فحص عمق الجيب ( bop)النزيف عند السبر العدالت والخاليا الليمفاوية وفروق غير معنوية في الخاليا األحادية ، الحمضات ، الخاليا القاعدية وأرتفعت القيم المتوسطة الخاليا والمجموعات الفرعية فروق معنوية في أظهرت هذه الدراسة أن . البيض غير معنوي ض اللثة و كان االرتباط بين المعلمات السريرية اللثوية ألنواع خاليا الكرياتألنواع خاليا الكريات البيض مع زيادة شدة أمرا ي الواسمات الجهازية التي تنشأ من آفات دواعم األسنان التي تتوسط حالة التهابية تسبب بدورها تغييرات فوأمراض اللثة ذات الشدة المختلفة مرتبطة بنوبة تجرثم الدم المحتملة . وخاصة أنواع خاليا كريات الدم البيض https://doi.org/10.1046%2fj.1365-2249.2003.02070.x https://doi.org/10.1111/prd.12002 https://doi.org/10.4103%2f0972-124x.51887 https://doi.org/10.9790/0853-1147178 hiba final.doc j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 122 dental caries and salivary physiochemical characteristics among osteoporotic old adult women hiba f. al-sekab, b.d.s. (1) ban s. diab, b.d.s., m.sc., ph.d. (2) abstract background: osteoporosis is a systemic skeletal disorder affects general health in addition to effect on salivary physical and chemical composition which lead to an adverse effect on oral health status. this study was conducted to evaluate the concentration of glycoprotein (osteonectin) in saliva and its effect on dental caries in relation to salivary flow rate and viscosity among osteoporotic women and compared to control group. materials and methods: the total sample composed of 60 females aged 60-65 years attending al-yarmook teaching hospital, 30 females diagnosed with osteoporosis by measuring bone density at the spine and femur with a dualenergy x-ray absorptiometry at t-score of >2.5, and 30 women without osteoporosis with t-score of -1 (control group).the diagnosis and recording of dental caries was through the application of d1-4mfs index according to criteria of mühlemman (1976). stimulated salivary samples were collected under standardized condition, according to tenovuo and lagerlöf, (1994). the flow rate and viscosity were estimated and then the saliva was analyzed for estimation of glycoprotein (osteonectin) by using enzyme-linked immunosorbent assay (elisa). results: the percentage of dental caries occurrence was 100% among osteoporotic group and control group. results revealed that dmfs value was higher but statistically not significant among osteoporotic women, concerning dmfs components, the data of the present study showed that the ds was lower but statistically not significant among osteoporotic women, while ms value was significantly higher among them (t=2.044, p<0.05, df =58), on the other hand the opposite figure was found concerning filling component fs however the difference was not significant. correlation coefficients of caries experience with salivary flow rate revealed a weak negative not significant correlation with d1-4mfs and its component.on the other hand, the data of the present study showed that salivary viscosity correlate weakly not significant in negative direction with ds and its severity and in positive direction with ms, fs, dmfs.. the correlation coefficient between salivary osteonectin and dental caries were weak significant in positive directions concerning ds and its severity except d3 and fs component as the relation were in negative direction, the positive not significant relation were also found between salivary osteonectin and ms,dmfs. concerning the relation between salivary osteonectin and physical properties of saliva, the data of the present study revealed a non-significant relation in negative direction with salivary flow rate and in positive direction for salivary viscosity. conclusions: dental caries revealed lower percentage of occurrence among osteoporotic group. key words: osteoporosis, dental caries, enzyme-linked immunosorbent assay (elisa), flow rate, viscosity. (j bagh coll dentistry 2014; 26(3):122-128). introduction osteoporosis is a major public health concern that affects millions of women around the world. osteoporosis is generally discovered in older age, but it is the result of many factors—modifiable and nonmodifiable (1).bone quality is not readily quantifiable (2). the mechanism of osteoporosis is such that the delicate balance of bone formation and bone reabsorption is disrupted, which results in long-term and uninterrupted bone loss (3). older women experience the onset of menopause and increased vulnerability to osteoporosis, as sex hormone deficiency (estrogen in women, testosterone in men) is similarly associated with bone loss (4). oral tissues and other parts of the human body are affected by aging; age-related systemic diseases and functional changes predisposed elderly patients to oral conditions (5). (1) m.sc. student department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. osteoporosis affect general health also has an effect on oral health. the health of a woman's body and oral cavity are bidirectional. saliva plays an important role in the maintenance of a healthy oral environment through its physical properties, including secretion rate and viscosity (6). because saliva is a fluids easily collected and contain locally and systemically derived markers of many systemic disease, they may offer the basis for the assessment and several biomarkers were quantitated in saliva collected by immunoassay (7,8). salivary osteonectin is a matricellular protein regulating matrix assembly, osteoblast differentiation, and survival. the researchers indicated that osteonectin is essential for normal bone mass (9). osteonectin binds both collagen and hydroxyapatite and regulates collagen fibril assembly (10). it inhibits the growth of hydroxyapatite crystals leading to development of dental caries (11). dental caries is the process of dynamic interaction between the tooth surface and the plaque biofilm. the balance between mineral loss j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 123 and gain can shift to favor either re-or demineralization (12, 13). the aims of this study were to determine thedental caries experience and their relationwith the salivary physiochemical characteristic include salivary floe rate, viscosity and osteonectin concentration among osteoporotic group andcompared with control group. materials and methods the studied sample consisted of 60 adult women (aged 60_65 years) (30 females with osteoporosis and 30 with a presumably healthy bones). the age was recorded according to the last birthday (14). they were patients attending alyarmook teaching hospital. subjects demonstrating the medical disorders that were not included in the study and use of medications such as corticosteroids, thyroid hormone, insulin dependent therapy, anti-seizure drugs and other supplements (15,16). this study was approved by the scientific committee in the institute and a verbal consent form was obtained from each participant enrolled in this study. the patients diagnosed with osteoporosis by measuring bone density at the spine and femur with a dual-energy x-ray absorptiometry (17). the assessment of bone mineral density was obtained from dual energy x-ray absorptiometry (dexascan) by using t-score. osteoporosis was defined by classifying the t-score measurements according to world health organization (who) (18): t score: < -1 is considered normal, -1 to -2.5 is considered osteopenia, > -2.5 are considered osteoporosis. the referral cases to the dxa investigation by consultants were randomly allocated to admit in this study. specific information was obtained from each patients taking in consideration; the age, medical history and then, the saliva samples were obtained from patients for biochemical test. the assessment and recording of caries experiences were done through the application of decayed (d), missing (m) and filled (f) surface index. in this study, the decayed fraction of the index was recorded according to the lesion severity using the criteria described by mühlemann (19). the collection of the stimulated salivary samples from the children was performed under standardized conditions according to the instructions cited by tenovuo and lagerlöf (20). straightaway after saliva collection, salivary flow rate was measured freshly and without centrifuged (after foam had all disappeared) by dividing the volume of the collected stimulated saliva in milliliter (ml) on the collection time in minute (min) (21). salivary viscosity was determined by measuring the volume rate of flow through a tube of known dimensions. this was done by using ostwald's viscometer which is simple device for measuring the viscosity of liquid (22). in this study, salivary viscosity was measured at room temperature and before centrifuging of salivary samples (23). the ostwald method is a simple and available method for the measurement of viscosity, in which viscosity of liquid is measured by comparing the viscosity of an unknown liquid with that of liquid whose viscosity is flow times of two liquids of equal volumes using same viscometer, and the coefficient of the viscosity of the saliva is determined (24). the salivary samples were then taken to the laboratory for biochemical analysis and centrifuged at 10,000 g at 2-8° c for 15 minutes. the clear supernatant was separated by micropipette and was stored at ( 20°c) in a deep freeze and further assessment for osteonectin level in saliva was done by special osteonectin kit (cusabio) using elisa technique which is a quantitative sandwich enzyme immunoassay technique (enzyme-linked immunosorbent assay). at the end of the assay, results are automatically obtained by the reading machine and then calculated in relation to the calibration curve. these results were obtained in traditional unit (ng/ml). intra and inter calibration were performed to overcome any problem that could be faced during the research, and to ensure proper application of diagnostic criteria used in recording dental status through inter calibration. statistical analysis and processing of the data were carried out using spss version 18. after exploring the data, it had been found that they were not normally distributed. the nonparametric mann-whitney u test was utilized for the parameters of the data which were not normally distributed and in this test the median and mean rank were used to analyze and determine the differences between the study and control groups. the correlation coefficient tests between the variables were done by using spearman's correlation. the confidence level was accepted at the level of less than or equal to 5%. the highly confidence level was accepted at the level of less than or equal to 1%. results the percentage of dental caries occurrence was found to be 100% for both groups.results revealed that dmfs value was higher but statistically not significant among osteoporotic women, concerning the data of the present study showed that caries-experience represented by ds was lower but statistically not significant among j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 124 osteoporotic women (table 1), while for missing component, data analysis of the present study showed that the ms value was significantly higher among osteoporotic women (t=2.044, p<0.05, df =58), while the opposite figure was found concerning filling component fs however the difference was not significant. on the other hand the severity of dental caries represented by grades of decayed fraction among osteoporoticare seen in table (2), the higher mean rank value was d3 than other grades of ds, however the mean rank value of both d4, d3 grades were found to be higher among osteoporotic women than control group, while the opposite figure was found for both d1 and d2, however the differences were not significant. correlation coefficients of caries experience with salivary flow rate for both osteoporotic women and control groups are seen in table (3). analysis among osteoporotic groups revealed a weak negative not significant correlation between salivary flow rate and ds, dmfs and weak negative not significant with ms, fs. while among control groups, data analysis showed weak positive not significant correlation between salivary flow rate and ds, and weak positive not significant correlation with fs, while the correlation was weak negative not significant with ms, and weak negative not significant correlation with dmfs. correlation coefficients of caries severity with salivary flow rate are seen in (table 4). as the mean value of d1 is constant (all equal to 0), there is no statistical correlation between flow rate and d1 among osteoporotic groups, but very weak negative not significant correlation between salivary flow rate and d2, d3, d4, concerning control group, the data showed weak positive not significant correlation with all grades of ds (d1, d2, d3, d4). table (5) illustrates the correlation coefficient of caries-experience in relation to salivary viscosity among osteoporotic women and control groups. analysis among osteoporotic group revealed that the salivary viscosity correlate weakly not significantly in negative direction with ds and in positive direction with ms, fs, dmfs, while among control group salivary viscosity correlate weakly not significantly in positive direction concerning dmfs, ms and in negative direction concerning ds, fs. in addition correlation coefficients of caries severity with salivary viscosity are seen in table 6 that shows the mean value of d1 is constant (all equal to 0), there is no statistical correlation between viscosity and d1 among osteoporotic group, and weak negative not significant correlation with d2, d3, d4, while among control group both d1 and d3 revealed a weak positive not significant correlation with salivary viscosity as well as it correlate negatively weakly not significantly with d2 and very weakly with d4.the correlation coefficient between salivary osteonectin and dental caries represented by dmfs and its components ds, ms, fs are shown in table (7), this table illustrate that these relations among osteoporotic groups were weak significant in positive directions concerning ds (r=0.373, p<0.05, df=58), and weak not significant correlation in positive direction with ms, dmfs, while with fs the correlation was the same but in negative direction. while among the control groups, the figure is different as all correlation were weak negative not significant between salivary osteonectin and ds, ms, dmfs, but very weak with fs. while concerning the correlation of salivary osteonectin with grades of dental caries, table (8) shows that as the mean value of d1 is constant (all equal to 0), there is no statistical correlation between osteonectin and d1 among osteoporotic women and very weak positive not significant correlation with d2, but weak with d4, in concerning to d3 grade, data analysis showed that this relation was very weak negative not significant among both osteoporotic women and control groups. also all remaining grades (d1, d2, and d4) in control groups revealed the same weak negative not significant correlation. in the present study data analysis showed that the relation between salivary osteonectin and salivary flow rate were weak not significant in negative direction for osteoporotic and for control group, concerning the correlation between salivary osteonectin and viscosity, the data of present study showed a weak positive not significant correlation among both osteoporotic and control groups, as shown in table (9). table 1: dental caries experience (mean± s.d.) among osteoporotic women and control groups. statistical difference control group osteoporotic women dental caries experience (p-value) t. test +sd mean +sd mean 0.12 1.60 25.95 54.70 33.85 67.17 dmfs 0.04 2.04* 25.40 31.47 32.30 46.80 ms 0.39 0.87 21.10 18.97 20.68 14.20 fs ― ― 3.81 4.60 8.72 6.17 ds j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 125 table 2: dental caries experience (ds) and severity represented by grades of d1-d4 (median& mean rank) among osteoporotic women and control groups test statistics control group osteoporotic women dental caries experience and severity p-value z. test mann-whitney u mean rank median mean rank median 0.08 -1.76 405. 00 32.00 0.00 29.00 0.00 d1 0.65 -0.45 420.50 31.48 1.00 29.52 1.00 d2 0.25 -1.15 385.50 28.35 0.00 32.65 0.00 d3 0.50 -0.68 407.00 31.93 2.00 29.07 0.00 d4 0.85 -0.19 437.00 30.93 3.50 30.07 3.00 ds table 3: correlation coefficients of salivary flow rate with caries experience (ds, ms, fs, and dmfs) among osteoporotic women and control groups control group osteoporotic women dental caries experience salivary flow rate salivary flow rate sig. p r sig. p r ns 0.11 0.29 ns 0.08 -0.32 ds ns 0.13 -0.29 ns 0.52 -0.12 ms ns 0.43 0.15 ns 0.38 -0.17 fs ns 0.51 -0.12 ns 0.17 -0.26 dmfs table 4: correlation coefficients of salivary flow rate with severity of dental caries (d1_d4) among osteoporotic women and control groups control group osteoporotic women severity of dental caries salivary flow rate salivary flow rate sig. p r sig. p r ns 0.76 0.06 — — — d1 ns 0.20 0.24 ns 0.19 -0.25 d2 ns 0.77 0.06 ns 0.27 -0.21 d3 ns 0.66 0.08 ns 0.78 -0.05 d4 table 5: correlation coefficients of salivary viscosity with caries experience (ds, ms, fs, and dmfs) among osteoporotic women and control groups control group osteoporotic women dental caries experience viscosity viscosity sig. p r sig. p r ns 0.75 -0.06 ns 0.89 -0.03 ds ns 0.60 0.10 ns 0.85 0.04 ms ns 0.85 -0.04 ns 0.71 0.07 fs ns 0.79 0.05 ns 0.74 0.06 dmfs table 6: correlation coefficients of salivary viscosity with severity of dental caries (d1-d4) among osteoporotic women and control groups control group osteoporotic women severity of dental caries viscosity viscosity sig. p r sig. p r ns 0.48 0.14 — — — d1 ns 0.10 -0.31 ns 0.78 -0.05 d2 ns 0.83 0.04 ns 0.51 -0.13 d3 ns 0.82 -0.04 ns 0.74 -0.06 d4 j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 126 table 7: correlation coefficients of salivary osteonectin with caries experience (ds, ms, fs, and dmfs) among osteoporotic women and control groups control group osteoporotic women dental caries experience osteonectin osteonectin sig. p r sig. p r ns 0.24 -0.22 sig 0.04 0.37* ds ns 0.17 -0.26 ns 0.23 0.23 ms ns 0.80 -0.05 ns 0.48 -0.14 fs ns 0.08 -0.33 ns 0.28 0.21 dmfs table 8: correlation coefficients of salivary osteonectin with severity of dental caries (d1-d4) among osteoporotic women and control groups control group osteoporotic women severity of dental caries osteonectin osteonectin sig. p r sig. p r ns 0.69 -0.08 — — — d1 ns 0.47 -0.14 ns 0.79 0.05 d2 ns 0.66 -0.08 ns 0.60 -0.10 d3 ns 0.31 -0.19 ns 0.10 0.31 d4 table 9: correlation coefficients of salivary osteonectin with physicochemical characteristics among osteoporotic women and control groups control group osteoporotic women physicochemical characteristics osteonectin osteonectin sig. p r sig. p r ns 0.56 -0.11 ns 0.24 -0.22 salivary flow rate ns 0.19 0.25 ns 0.05 0.36 salivary viscosity discussion aging is the accumulation of changes in a person over time; it is an important part of all human societies reflecting the biological changes that occur (25,26). osteoporosis is a major public health problem all over the world; it remains the major epidemiological burdens of postmenopausal women (27), and could affect oral health. thus, the elderly could help live a healthier and more meaningful life with the prevention of these diseases (28). in terms of caries experience among osteoporotic women group, the present study revealed that in spite of no significant differences between both groups but the mean rank level of decade surfaces in osteoporotic groups is slightly lower than control one, also there is a weak negative not significant correlation between salivary flow rate and caries experience. the salivary flow rate plays an important role in relation to dental caries because the washing action of saliva as well as its protective constituents increased with increase flow rate. this result was in agreement with the results reported by many previous studies (29-30), and was in disagreement with the results that concluded by others (31-35).another explanation could be given to the salivary viscosity, as the result of present study showed an inverse but not significant relation between salivary viscosity and dental caries, this result agree with many studies that found a positive correlation between concentration of mucins and salivary viscosity that are known to have a protective role toward oral surfaces and their absence has been associated with an increased prevalence of dental caries in adults (36-41), but in contrast result shown by others (42,43) reported a weak non-significant positive correlation, in addition other explanation could be given to the salivary osteonectinthat showed positive correlation with statistical significance with ds, this is due to physiological role of osteonectin as a protein associated with the formation of collagen containing mineralizing tissues like human bone, as well as human dentin and cement, it inhibits the growth of hydroxyapatite crystals leading to development of dental caries. this result was in agreement with the results reported by many previous studies (4447), and was in disagreement with the results that concluded by others (48-50). concerning the correlation of the salivary osteonectin with flow rate, data analysis of the present study reported a weak not significant in negative direction for osteoporotic group. this is in agreement with some previous studies (35, 51).this may be explained by the fact that slight increase in j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 127 salivary flow rate among them leadto decrease protein concentration (osteonectin) (10, 52-54). the correlation of the salivary osteonectinwith viscosity was found to be a positive relation in both osteoporotic and control groups. the explanation for this can be attributed to the fact that the salivary osteonectin is one of the important protein components of human saliva, as the main contributor to salivary viscosity is the mucous glycoprotein (30,55,56). in addition the concentrations of proteins, increased in subjects with moderate and severe inflamatory disease while flow rate decreased, this is showed by others (57-59). 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1:17-22. 54. helmerhorst e, oppenheim f. saliva: a dynamic proteome. j dent res 2007; 86(8):680–693. 55. amerongen a, bolscher j, veerman e, et al. salivary proteins: protective and diagnostic value in cariology? caries res 2004; 38: 247-53. 56. sánchez g, miozza v, delgado a, et al. relationship between salivary mucinor amylase and the periodontal status. oral diseases 2013; 6(19): 585–591. (ivsl). 57. shaila m, pai g, shetty p, et al. salivary protein concentration, flow rate, buffer capacity and ph estimation: a comparative study among young and elderly subjects, both normal and with gingivitis and periodontitis. j indian soc periodontol 2013; 1(17): 42-6. 6 j bagh college dentistry vol. 33(1), march 2021 depression status depression status in relation to dental caries and salivary creactive protein among 17 years old secondary school female in baghdad city/iraq. noor a. al-bazaz(1) , nada jafer mh radhi (2) https://doi.org/10.26477/jbcd.v33i1.2921 abstract background: depression is a state of low mood and aversion to activity, it can affect a person's thoughts, behavior and sense of well-being. it can affect oral health and lead to an increased risk of dental caries. dental caries is the most common oral infectious diseases that stresses the immune system and causes changes in cellular and molecular components of peripheral blood and c-reactive protein is one of these components, considered a key biomarker of inflammation. this study was conducted to assess the effect of depression status on dental caries among 17 years old secondary school female students in relation to salivary c-reactive protein. materials and methods: a cross sectional study was carried and the whole sample composed of 500 female students selected from first alrasafa directorate schools in baghdad/ iraq. consent form was achieved from the ethical approval committee in college of dentistry/university of baghdad. all students were subjected to children depression inventory questionnaire by kovacs in 2011. dental caries was registered according to manji et al. 1989, decay (1-4) missing-filled surface index. subsamples were selected from high and low grade of depression to analyze c-reactive protein. results: the percentage of occurrence of depression was 100%. the mean value of caries experience and severity were found to be higher among female students with high depression grade in comparison with low depression grade. the mean value for creactive protein was higher in high depression grade. there is a diversity in the results of caries experience with c-reactive protein. the percentage of depression occurrence was 100% which means a high degree of depression, and this could be due to the life difficulties, tension and economic issues that all lead to mental problems. the severity of dental caries increased as a result of stress and anxiety that may cause poor dental health. psychological factors interact through complex pathophysiological and behavioral mechanisms that may cause elevated c-reactive protein. conclusion: depression has a negative impact on a person’s oral health including dental caries. elevated c-reactive protein levels have been associated with psychological depression. key words: depression, children depression inventory, dental caries, c-reactive protein. (received: 12/12/2020, accepted: 19/1/2021) introduction depression is a mood disorder that causes a persistent feeling of sadness and loss of interest or pleasure in most or all normal activities (1). it can be considered as one of the significant causes of mortality and morbidity and a contributor to the global burden of disease (2). it can affect oral health as a result of neglecting oral hygiene procedures, cariogenic nutrition, and avoidance of necessary dental care which leads to an increased risk of dental caries (3). children depression inventory (cdi) is one of various approaches that are available to measure depression for children and adolescent (4). it is self-report as the person being evaluated records his/ her answers on the test sheet, other than giving verbal answers to questions, then analyzed by the examiner (5). (1) master student, department of preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of preventive dentistry, college of dentistry, university of baghdad. corresponding author, salwanby@gmail.net reliability and validity of the depression inventory scale cdi2 -were guaranteed as this scale was used and tested for its reliability and validity earlier by salman, 2014 and muwafaq, in 2019 (5,6,7). depression like dental caries, both are chronic diseases. dental caries is a preventable disease, bacterially established and progressed when acid producing by bacteria utilizes dietary sugars, diffuses into the tooth and dissolves its minerals, causing demineralization (8,9). dental caries is the biggest threat to oral health and by far the most common oral infection disease. it has been well proven that the oral cavity contains some of the most varied and vast flora in the entire human body that cause infection which can also seriously stress the immune system and diminish its ability to deal with other infections and diseases. infection causes changes in cellular and molecular components of peripheral blood and c-reactive protein is one of these components, considered a key biomarker of inflammation (10). it is" an acute phase protein produced by liver and widely used as a marker of inflammation (11). elevated https://doi.org/10.26477/jbcd.v33i1.2921 mailto:salwanby@gmail.net 7 j bagh college dentistry vol. 33(1), march 2021 depression status levels of this protein hasbeen associated with psychological depression (12). since there is no previous iraqi study regarding the effect of depression on dental caries among 17 years old secondary school female students in baghdad / iraq in relation to salivary c-reactive protein, this study was conducted. the study hypothesis was that depression has no effects upon salivary creactive protein in relation to oral health status. materials and methods the current study was carried out in baghdad/iraq starting from november, 2019; till july, 2020. total sample involved 500 randomly selected females students aged 17 years from secondary schools in first alrasafa directorate in baghdad/ iraq in which their total number was 9567 students using specific statistical program called epi info 7 (is a public software package designed for the global public health community of practitioners and researchers) (13). official consent was received fromthe iraqi ministry of education and from schools authority to observe the students without obligation and to ensure help. the age was calculated according to last birthday according to world health organization, 1997 (14). a scale called children’s depression inventory (cdi2) was used to divide the sample into three groups according to the severity of depression (low, medium, high grade). arabic version and translation validity of cdi2 was obtained by salman in 2014 and muwafaq in 2019, by two translators who translated the items of the test from its original language to the target language (arabic) in ministry of higher education and scientific research (6,7). all sample was requested to fill all items of the scale questionnaire by themselves. subgroups of 45 students were taken arbitrarily from high grade and 45 students from low grade of depression to make comparisons regarding salivary c-reactive protein. oral health assessments were carried out according to the basic procedures of the oral health which surveys of the world health organization 1997 (14). dental caries was recorded according to manji et al. (1989) (15) index criteria; this criteria permit for recording caries lesion for permanent teeth by its severity. clinical examinations were carried out using plane mouth dental mirrors and probe. unstimulated salivary samples were collected in sterile screw capped tubes (16), then taken to the laboratory for centrifugation and analysis. in the saliva of 90 students, c-reactive protein concentration in mg/dl was measured by elisa kit using enzyme linked immuno-sorbent assay (elisa) machine. the principle of reagent preparation, technique assay and calculation of results were all completed according to manufactures procedure instructions. statistical package for social sciences (spss version 21) was used for data description, presentation and analysis. for quantitative variables, mean and standard error were used. one way analysis of variance (anova) was used to identify differences. pearson correlation test was used for correlation between quantitative variables (17). for the level of significance, it was not significant p>0.05, significant p≤0.05. results table 1 shows the distribution of sample according to depression grades . it was found that the higher occurrence (49%) was for low depression grade followed by medium grade (23.8%) then high grade (18.2%) was the lowest. table 1: distribution of the sample according to depression grade. groups number % low 245 49.00 medium 164 32.80 high 91 18.20 caries experience in each grade of depression is shown in table 2. for decay surface (ds), missing surfaces (ms) and dmfs, the higher value was among high grade of depression. the fillings component(fs) of dmfs index, higher value was among medium grade. table 3 demonstrates the mean values of caries severity represented by grades of lesion (d1-4). the mean of all grades of lesion severity was higher among high grade of depression. concerning table 4, it showed the result of salivary c-reactive protein according to depression grades, the mean value was higher in high grade with significant difference among groups. 8 j bagh college dentistry vol. 33(1), march 2021 depression status table 2: dental caries experience according to depression grade variables low medium high f probability value mean se mean se mean se ds 7.992 0.345 8.366 0.401 10.626 0.494 8.773 0.000* ms 0.469 0.127 0.415 0.168 0.769 0.258 0.875 0.418 fs 21.637 0.156 2.829 0.201 2.527 0.273 12.080 0.000* dmfs 10.098 0.352 11.610 0.416 13.923 0.589 16.638 0.000* degree of freedom=2, se: standard error, ds: decay surface, ms: missing surfaces, fs: fillings surface, *=significant at p≤0.05. table 3: caries severity represented by grades of lesion according to depression grade variables low medium high f probability value mean se mean se mean se d1 6.082 0.241 6.720 0.297 7.407 0.336 4.594 0.011* d2 1.869 0.101 1.732 0.121 3.044 0.179 22.537 0.000* d3 0.078 0.021 0.067 0.023 0.110 0.043 0.501 0.606 d4 0.010 0.011 0.000 0.000 0.011 0.011 1.293 0.275 se: standard error, decay (1-4) missing-filled surface index, *=significant at p≤0.05 table 4: salivary c-reactive protein in ml/min according to depression grade variables groups df probability value high low mean se mean se crp 2.625 0.143 1.399 0.068 88 0.000* se: standard error , df: degree of freedom, crp: creactive protein. in table 5, the correlation coefficient of caries experience with c-reactive protein according to grades of depression can be seen. for low depression grade, the relations goes in weak positive direction except for decay surface which goes in weak negative direction. regarding high depression grade, all relations go in weak negative direction. there was a significance in low depression grade for the relation between missing surfaces and c-reactive protein, while other relations shows no significance. 9 j bagh college dentistry vol. 33(1), march 2021 depression status table 5: correlation coefficient of caries experience with c-reactive protein according to grades of depression. groups c-reactive protein r p low depression ds -0.186 0.220 ms 0.406 0.006* fs 0.108 0.481 dmfs 0.027 0.860 high depression ds -0.116 0.447 ms -0.080 0.599 fs -0.266 0.077 dmfs -0.227 0.134 ds: decay surface, ms: missing surfaces, fs: fillings surface, *= significant at p≤0.05. correlation coefficient of caries severity was represented by d1-4 with c-reactive protein according to different grades of depression demonstrated in table 6. for all depression grades, the correlations were in weak negative nonsignificant direction except for d3 (grade 3) of high depression grade, it was weak positive, however the correlation of d4 (grade 4) of low grade depression shows a significant relation. table 6: correlation coefficient of caries severity with c-reactive protein according to different grade of depression groups c-reactive protein r p low depression d1 -0.174 0.253 d2 -0.225 0.137 d3 -0.083 0.586 d4 . 0.000* high depression d1 -0.152 0.318 d2 -0.038 0.806 d3 0.002 0.991 d4 -0.291 0.053 decay (1-4), *= significant at p≤0.05. discussion all female students included in the study have symptom of depression (percentage of depression occurrence is 100%), and this could be due to the difficult life conditions represented by stress and financial difficulties that all lead to severe psychological problems (18,19). the mean values of caries experience concerning decayed, missing surfaces and dmfs values were higher among high grade of depression. also caries severity represented by grades of lesion washigher in high depression grade, this result is in agree with other studies (6,20). the reasons for these results could be due to: ➢ behavioral effects of stress and anxiety in depressed patients may cause poor dental health. it can be difficult to have the discipline to follow a strict tooth care routine when battling a mental health condition. depressed people are also more likely to skip visits to the dentist due to dental fear especially in females (21). ➢ depression causes diminishing in immune system function causing activation and colonization of pathogenic and cariogenic bacteria (20). ➢ increased tendency to have sweet food to give happiness and pleasure to the brain, and this type of food is cariogenic and ends with the development of dental caries (22,23). ➢ increased carbohydrate intake as a result of decrease serotonin metabolism which occurs during depression, and this will provide a noble environment for the development of acidic uric bacteria (23). filled component of dmfs index (filled surface) was higher in medium and high grade than low grade of depression and this could be due to mysophobia (germophobia) which is “ a term used to describe a pathological fear of germs, bacteria, uncleanliness, contamination, and infection”. 10 j bagh college dentistry vol. 33(1), march 2021 depression status depressed people are at higher risk of developing phobias and may start focusing on germs, increased use of hygiene measures and triesto visit dentist whenever they have decay as a result of depressed mentality (24). the mean value for creactive protein was higher in high depression grade with significant difference. this result goes in line with some other studies (25,26). the underlying mechanism between inflammation and depression is not fully understood. systemic inflammation and psychological factors interact through complex pathophysiological and behavioral mechanisms. first, inflammation may lead to depression as proinflammatory cytokines might contribute to decreased production of serotonin and increased production of kynurenic and quinolinic acids (27) that leads to decreased production of trophic factors, including brainderived neurotrophic factor, a factor associated with depression. second, depression may also lead to inflammation. psychological stress activates the hypothalamic-pituitary-adrenocortical axis and sympathetic nervous system, which releases stress and depressive hormones. these hormones, together with cytokine release, initiate the acutephase response triggering inflammation. (28,29). the diversity in the results of caries experience with c-reactive protein has many explanations. for positive correlations, this may be attributed first to the immune response during caries progression, development and thus indicative of inflammation. similar results were concluded by the previous studies (30). negative correlations of caries experience with c-reactive protein can be explained by the fact that dental caries is a multifactorial disease, caused by complex interactions among acid-producing bacteria, fermentable carbohydrates and many host factors including saliva rather than to be related to single factor (31). also presence of abundant proteins in human saliva such as amylases, proline rich proteins, statherin, histatin, mucin and cystatins that have a “double edged swords” role, so any modification indicate various physiological and pathological fluctuations (32,33). they may play a protective role or may increase colonization of microorganism depending on their location and action (34). conclusion the percentage of depression occurrence was 100%. caries experience was found to be higher among high depression grade. the same result for caries severity grade 1 (d1) and grade 2 (d2) produced significant differences. the correlations of salivary c-reactive protein with caries experience and caries severity showed diversity in the results. referances 1. kotov r, gamez w, schmidt f, watson d. linking "big" personality traits to anxiety, depressive, and substance use disorders: a meta-analysis. psychological bulletin. 2010; 136 (5): 768–821. 2. kessler r.c., nelson c.b., mcgongale k.a., liu j., swartz m. and blazer dg., comorbidity of dsmiiir major depressive disorder in the general population, results from the us national comorbidity survey, br j psychiatry. 2006; 168: 17-30. 3. taskinen, h., kankalla, t., rajavaara, p., pesonen, p. self-reported causes for referral to dental treatment under general anaesthesia (dga): a cross-sectional survey. eur arch paediatr dent. 2014; 15(2):105-12. 4. kovacs, m. children depression inventory (cdi) manual toronto, canada: multi health systems, 1992. 5. kovacs, m. children depression inventory (cdi2) manual toronto, canada: multi-health systems, 2011. 6. al-salman h. depression status in relation to oral health condition and salivary physiochemical characteristics among 15 years old school students in al-swera city-wassit governorate-iraq. a master thesis submitted to the college of dentistry, university of baghdad. 2014. 7. muwafaq s. the impact of depression status on oral health condition and salivary growth hormone related to anthropometry among internally displaced adolescence in baghdad/iraq. a master thesis / college of dentistry / university of baghdad. 2019. 8. selwitz, r.h., ismail, a., pitts, nb. dental caries. lancet. 2007; 369(9555): 51-9. 9. iaas, j. a., griffen, al., dardis, sr., lee, am., olsen, i., dewhirst, fe., paster, bj. bacteria of dental caries in primary and permanent teeth in children and young adults. journal of clinical microbiology.2008; 46(4): 1407-17. 10. lopez r, baelum v, hedegaard cj, bendtzen k. serum levels of c-reactive protein in adolescents with periodontitis. j periodontol. 2011;82: 543–49. 11. pearson ta, mensah ga, alexander rw, anderson jl, hong y, myers gl, rifai n, smith sc, taubert k, tracy rp, vinicor f. markers of inflammation and cardiovascular disease. application to clinical and public health practice. circulation. 2003;107:499–511. 12. yunsheng ma, david e., sherry l, milagros c. rosal s. ockene. association between depression and creactive protein. cardiology research and practice. 2010; volume 2011 |article id 286509. 13. cdc (centers for disease control and prevention). 2009. "epi-info-community-edition/license. 14. who. world health organization. oral health surveys. basic methods, geneva.1997. 15. manji, f., fejerskov, o., baelum, v. pattern of dental caries in an adult rural population. caries research 1989; 23(1): 55-62. 11 j bagh college dentistry vol. 33(1), march 2021 depression status 16. navazesh m., kumar sks. measuring salivary flow: challenges and opportunities. j amer dent assoc 2008; 139 (2): 35-40. 17. jennifer dc. pearson's product-moment correlation: sample analysis. university of hawaii at mānoa. department of nursing. united kingdom. 2015. 18. lando, b. 4 years later: dump those ungrateful, vicious iraqis. the huffington post. j the blog 2007; 2(13) :22-28. 19. unicef. geneva. the unicef children's fund, 15th of march us preventive services task force. guide to clinical preventive services, 2013; 2nd ed, alexandria, va., international medical publishing. 20. rashid t and heider i. "life events and depression" (pdf). annals of punjab medical college.2008; 2(1):44-56. 21. taskinen, h., kankalla, t., rajavaara, p., pesonen, p. self-reported causes for referral to dental treatment under general anaesthesia (dga): a cross-sectional survey. eur arch paediatr dent. 2014; 15(2):105-12. 22. thongkumpala, yupin. cariogenic food consumption behaviors and associated factors in primary school students wat donwai school tambon bangkrateuk amphur sampran nakhonpathom province. region 4-5 medical journal-วารสาร แพทย ์เขต 4-5, 2010: 219229. 23. mennella, ja, pepino, my., lehmann-castor, sm., yourshaw, lm. sweet preferences and analgesia during childhood: effects of family history of alcoholism and depression. addiction, 2010; 105: 666–75. 24. grant je. "clinical practice: obsessive-compulsive disorder". the new england journal of medicine. 2014; 371 (7): 646–53. 25. liukkonen t, silvennoinen-kassinen s, jokelainen j, räsänen p, leinonen m, meyer-rochow vb, timonen m. the association between c-reactive protein levels and depression: results from the northern finland 1966 birth cohort study. biol psychiatry. 2006;60(8):825-830. 26. hamer m, batty gd, marmot mg, singh-manoux a, kivimäki m. anti-depressant medication use and creactive protein: results from two population-based studies. brain behav immun. 2011;25(1):168-173. 27. raison cl, miller ah. is depression an inflammatory disorder? curr psychiatry rep. 2011;13(6):467-475. 28. capuron l, miller ah. immune system to brain signaling: neuropsychopharmacological implications. pharmacol ther. 2011;130(2):226-238. 29. kyrou i, tsigos c. stress hormones: physiological stress and regulation of metabolism. curr opin pharmacol. 2009;9(6):787-79319758844 30. gawri s, shukla p, chandrakar a survey of micro flora present in dental caries and it’s relation to environmental factors. science and technology , 2012, 4: 09-12. 31. martins c, buczynski ak, maia lc, siqueira wl, castro gf. salivary proteins as a biomarker for dental caries--a systematic review. j dent 2013; 41:2-8. 32. loo ja, yan w, ramachandran p, wong dt. comparative human salivary and plasma proteomes. j dent res 2010; 89: 1016-1023. 33. kościelniak d, jurczak a, zygmunt a, krzyściak w. salivary proteins in health and disease. acta biochim pol 2012; 59: 451-457. 34. vibhakar pa, patankar sr, yadav mr, vibhakar pa. salivary total protein levels and their correlation to dental caries. inter j oral & maxillofac path 2013; 4: 1316. : المستخلص . يةالرفاهب : االكتئاب هو حالة من المزاج المنخفض والنفور من النشاط، ويمكن أن تؤثر على أفكار الشخص، والسلوك والشعور خلفيةال األسنان هوو تسوس تسوس األسنان. خطر ويؤدي إلى زيادة صحة الفم يؤثر على شيوعا رأكث يمكن أن التي في الفم األمراض المعدية هو سي –المتفاعل العالي البروتينان على الجهاز المناعي ويسبب تغييرات في المكونات الخلوية والجزيئية من الدم المحيطي و ضغطت وكان الهدف من هذه الدراسة لتقييم تأثير حالة االكتئاب على تسوس األسنان .عتبر عالمة حيوية رئيسية لاللتهابي واحد من هذه المكونات و .سي– المتفاعل العالي البروتينالمدارس الثانوية في ما يتعلق الباتة من طسن 17 في عمر األولى في رصافةطالبة تم اختيارهن من مدارس مديرية ال 500من تتكون العينة اإلجمالية تم اجراء دراسة مقطعية : العمل طرقالمواد و الطالب جميع وخضع بغداد. جامعة األسنان/ طب كلية في األخالقية الموافقة لجنة من الموافقة نموذج على الحصول تم بغداد/العراق. لمانجي decay 1-4 شدة التسوس لمؤشر . تم تسجيل تسوس األسنان وفقا2011الستبيان جرد اكتئاب األطفال من قبل كوفاكس في عام .سي– المتفاعل العالي البروتينمنخفضة من االكتئاب لتحليل العالية والدرجة المن مجموعات فرعية. تم اختيار 1989وآخرون الطالبات الالتي اتصفن باكتئاب مرتفع. وكان القيم الوسطية لشدة تسوس أعلى بين %. ووجد أن 100كانت نسبة حدوث االكتئاب النتائج: . سي– المتفاعل العالي البروتين أعلى في درجة االكتئاب العالية. هناك تنوع في نتائج تجربة تسوس مع التفاعلي cمتوسط قيمة بروتين االكتئاب حدوث نسبة وه100تبلغ والقضايا ذا%، والتوتر الحياتية الصعوبات بسبب ذلك يكون وقد االكتئاب من عالية درجة يعني تؤدي جميعها إلى مشاكل عقلية. األسنان. االقتصادية التي صحة سوء يسبب قد والقلق الذي نتيجة لإلجهاد تسوس األسنان شدة ازدادت .سي – المتفاعل العالي البروتين السلوكية المعقدة التي قد تسبب ارتفاعو ا المرضيةتتفاعل العوامل النفسية من خالل اليات الفسيولوجي – المتفاعل العالي البروتينان ارتفاع مستويات للشخص بما في ذلك تسوس األسنان.: االكتئاب له تأثير سلبي على صحة الفم اتستنتاجاال .االكتئاب قد ارتبط معسي articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ neamat final.doc j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 160 dental caries and treatment needs among 12 year-old school children in heet city/al-anbar governorate/iraq neamat m. al-ani, b.d.s. (1) sulafa k. el-samarrai, b.d.s, m.sc., ph.d. (2) abstract background: dental caries is one of the most prevalent chronic diseases of people worldwide that lead to the pain and disability across all age groups and still consider as a major cause of tooth loss. the aim of this study was to assess the prevalence and severity of dental caries and treatment needs among school children in heet city. materiales and methods: the sample included all school children at age of (12 years old) males and females from urban areas in heet city. diagnosis and recording of dental caries and treatment needs were done according to the criteria of who. results: the prevalence of dental caries was (90.2%). the dmfs/dmfs values were (5.85±0.168, 1.57±0.146) respectively for the total sample. females were found to have higher value as compared to males with statistically highly significant difference (p< 0.01) for dmfs, while the opposite picture was found for dmfs. the higher percentage of examined children were in need of preventive or fissure sealant (91.6%), followed by those in need of one surface filling (80.4%). conclusions: school children were found to have a high prevalence of dental caries, thus there is a need for preventive programs among those children. key words: dental caries, treatment needs, heet city. (j bagh coll dentistry 2014; 26(3):160-163). introduction several iraqi studies recorded a high prevalence and severity of dental caries among different age groups as well as in different geographical locations (1-9).the type of treatment required was found to be affected by several factors as age, area of residency, gender and socioeconomic variables (10). the type of treatment needed tend to become more complicated as well as need for treatment increased with age (2,4). this study was designed to evaluate the prevalence and severity of dental caries, also to measure dental treatment needs for dental caries among school children. materials and methods the sample included all school children at age of (12 years old) males and females from urban areas in heet city/anbar governorate. the sample consisted of (872), 454 males and 418 females. permission was obtained from the heet education institution in order to meet subjects with no obligation, the purpose of the study was explained to the school authority to ensure full cooperation, also special consents were distributed to parents to obtain permission for including their children in the study with full cooperation. children without permission from their parents, with serious systemic diseases and/or uncooperative were not examined, so the final total sample of (764) were examined. (1)m.sc. student department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2)professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. after completion of clinical examination, parents were informed about oral health condition and treatment needs for their children using special forms. examinations and oral health assessments were performed according to the basic methods of who (1987). analysis and processing of the data were carried out using spss version 19, statistical tests used are paired t-test, z-test, zproportion, chi-square and mann-whitney u test and kruskal wallis tests used instead of t-test and anova test respectively because data were found to be not normally distributed. p-values less than 0.05 were considered as statistically significant, while p-values less than 0.01 were recorded as a highly significant. results data analysis showed that only (9.8%) of the total sample were caries-free, malesdemonstrated a higher percentage of caries-free compared to females (12.7% for males and 6.5% for females), thus the prevalence of dental caries in the present study was (90.2% among total sample).females were found to have higher dmfs mean rank value than males, this difference was found to be statistically highly significant (p< 0.01), the ds value was found to be the higher fraction for the total sample, the difference for ds was found to be statistically highly significant between the two gender (p< 0.01), while differences for ms and fs was found to be statistically not significant (p> 0.05) (table 1). mean rank values of dmfs, ds, ms, and fs are illustrated in the table (2). in this study males j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 161 were found to have higher dmfs mean rank value as compared to females, this difference was statistically highly significant (p< 0.01). the extracted teeth by caries (ms) was found to be nearly similar to decayed surfaces (ds) of the teeth. the difference for ds/ms was found to be statistically highly significant between the two gender (p< 0.01), while for fs fraction, there was no statistically significant difference (p> 0.05). percentages of children with each category of dental treatment needs by gender are illustrated in figure (1). the higher percentage of children were found to be in need of preventive or fissure sealant, followed by those in need of one surface filling, two or more surface filling and those in need of crown for any reason constitute the lower percentage. table 1: caries-experience dmfs, ds, ms, fs among 12 year-old school children by gender. z-test mann-whitney u mean rank median ±se mean gender caries-experience -2.742** 64289.500 362.19 4.00 0.196 4.78 males ds 405.90 5.00 0.220 5.56 females 4.50 0.147 5.14 total -0.054 72518.500 382.31 0.00 0.093 0.52 males ms 382.72 0.00 0.096 0.51 females 0.00 0.067 0.52 total -1.823 70198.500 376.63 0.00 0.037 0.15 males fs 389.26 0.00 0.046 0.23 females 0.00 0.029 0.18 total -2.898** 63811.500 361.02 5.00 0.229 5.45 males dmfs 407.25 6.00 0.247 6.32 females 5.00 0.168 5.85 total **highly significant , p< 0.01 table 2: caries-experience dmfs, ds, ms, fs among 12 year-old school children by gender z-test mann-whitney u mean rank median ±se mean gender caries-experience -2.774** 66581.500 397.21 0.00 0.114 0.95 males ds 365.55 0.00 0.089 0.58 females 0.00 0.074 0.78 total -3.308** 67279.500 395.50 0.00 0.179 1.13 males ms 367.52 0.00 0.088 0.40 females 0.00 0.105 0.79 total -0.139 72544.500 382.37 0.00 0.007 0.01 males fs 382.65 0.00 0.006 0.01 females 0.00 0.005 0.01 total -3.732** 64015.000 403.48 0.00 0.237 2.08 males dmfs 358.32 0.00 0.150 0.99 females 0.00 0.146 1.57 total **highly significant, p< 0.01 figure 1: distribution of children according to the type of treatment needs j bagh college dentistry vol. 26(3), september 2014 dental caries and orthodontics, pedodontics and preventive dentistry 162 discussion there is no previous epidemiological study concerning population in heet city, so results of the present study can be considered as a base line data for comparison with other studies in iraqi governorates and different parts of the world. in this study the prevalence of dental caries was found to be (90.2%) for 12 year-old school children. this percentage was higher than that reported by mahmood (12), al-salman (3), ahmed et al (13), baram (14), and al-sadam (9) in iraq. while this percentage was lower than that reported by al-haddad (15) in yemen, ali (11) and al-ghalebi (8) for other ages in iraq. unfortunately only a few iraqi studies are present regarding the age index of 12-years to compare with data recorded by the current study. the high caries prevalence recorded by this study may partly be attributed to lower fluoride level in drinking water in iraq that was ranging between 0.12-0.22 (4). for the diagnosis and recording of cariesexperience, dmfs/dmfs indices were used in present study. the mean dmfs value was higher than that recorded by baram (14), al-sadam (9) for age of 12 years and diab (16), al-ghalebi (8) for other age groups, while dmfs value was lower than that recorded by diab (16), jabber (17), alghalebi (8) for other age groups and al-sadam (9) for 12 years-old age. variation in dietary habits, oral hygiene measurements as well as dental health services between governorates can explain the variation in caries-experience between the present study and others. it is worth to mention that values dmfs/dmfs may be underestimated as bitewing radiographs were not taken, for the detection of interproximal caries. females had statistically higher caries-experience than males for permanent teeth, this result is similar to that recorded by baram (14) for the same age group, diab (16) and al-ghalebi (8) for other age groups. this finding may be attributed to the earlier eruption of permanent teeth in females than males of the same age group, therefore female's teeth may be exposed to environmental factors more than males, thus increasing risk for dental caries (1,18,19). at the same time, females were found to have a lower dmfs values compared to males which was statistically highly significant, this is may be related to the earlier shedding of deciduous teeth in females compared to males as recorded by previous iraqi studies. this study shows that the ds fraction was higher than ms and fs components of dmfs index, an indication of a poor dental treatment. ms/ms fraction was higher than fs/fs fraction, this mean that even if treatment is present, it is toward extraction rather than restoration. this result is in agreement with other studies by baram(14), al-ghalebi (8). most of children in this study were in need of preventive or fissure sealant (91.6%), that is to say in need of recall for regular visits and the prophylactic application of fluoride therapy and fissure sealant to prevent initiation of dental caries. the second type of treatment needed was the one surface filling (80.4%), followed by two or more surface filling (63.6). the values reflecting the increase need for restorative treatments to prevent progression of dental caries. this result was in agreement with results found by al-ghalebi (8), and al-sadam (9) in iraq where the majority of children were in need of restoration. the increase in the prevalence of dental caries among school children in heet city with the increase in dental treatment need indicate the need for either a public or school preventive programs for those children, involving dental health education and improvement of dental knowledge and attitude towards both oral hygiene and proper nutrition. references 1. al-farhan s. aspects of dental health in iraq. a master thesis, college of dentistry, university of dundee, 1976. 2. el-samarrai s. oral health status and treatment needs among preschool children in baghdad, iraq. a master thesis, college of dentistry, university of baghdad, 1989. 3. al-salman fd. prevalence of dental 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of baghdad, 2008. 18. daood zh. chrono;ogy of permanent teeth emergence for iraqi children/baghdad city (a cross-sectional study). a master thesis, college of dentistry, baghdad university, 2001. 19. mcdonald re, avery dr, dean ja. dentistry for the child and adolescent. 8th ed. philadelphia: mosby; 2004. noor final.doc j bagh college dentistry vol. 26(2), june 2014 the effect of in ssup up restorative dentistry 24 the effect of in office bleaching on surface roughness and micro-hardness of newly developed composite materials (in vitro study) noor s. nadhum, b.d.s., h.d.d. (1) ali h. al-khafaji, b.d.s., m.sc. d. (2) abstract background: alterations in the microhardness and roughness are commonly used to analyze the possible negative effects of bleaching products on restorative materials. this in vitro study evaluated the effect of in-office bleaching (sdi pola office +) on the surface roughness and micro-hardness of four newly developed composite materials (z350xt –nano-filled, z250xt-nano-hybrid, z250-mico-hybrid and silorane-silorane based). materials and methods: eighty circular samples with a3 shading were prepared by using teflon mold 2mm thickness and 10mm in diameter. 20 samples for each material, 10 samples for base line measurement (surface roughness by using portable profillometer, and micro-hardness by usingdigital micro vickers hardness tester), and 10 samples for after bleaching measurement. the appropriate bleaching procedure was performed on the top surface of test groups for 90 minutes total bleaching period. then surface roughness and hardness were tested at the end of the duration. statistical analysis was carried out using anova, lsd and t-test. results: there was a highly significant increase in surface roughness of all tested groups after bleaching. there is a highly significant increase in micro-hardness for z250, there is decrease in micro-hardness for siloraneand z250xt and there is a non-significant increase in micro-hardness of z350xt. conclusion: bleaching has a negative effect on surface roughness of all the tested materials, as surface roughness increased after bleaching. micro-hardness is a material dependent, there is different reaction to bleaching depending on the resin, load and size of the fillers used in the materials. nano-filled composite is the material that has better performance than the other tested materials, as it is the material that has the least affection by bleaching. key words: surface roughness, micro-hardness, in-office bleaching, nano-filled, nano-hybrid, silorane. (j bagh coll dentistry 2014; 26(2): 24-29). introduction dental bleaching is one of the most commonly used dental esthetic clinical procedures. this treatment offers higher self-esteem to patients with minor consequences to teeth and gingival tissues when it is well indicated and performed (1). the aesthetic appearance of anterior teeth has become a major concern for patients. discolored vital anterior teeth have long been treated with different approaches, including crowns, direct and indirect veneers, composite resin restorations, and, most conservatively, bleaching. both takehome and in-office bleaching techniques have proven effective in whitening teeth, with the latter having the advantage of producing immediate results (2).the typical in-office bleaching regimen involves application of a high-percentage hydrogen peroxide formulation to the teeth surfaces, which is activated either chemically or by a light source. the theoretical advantage of using lights is their ability to heat hydrogen peroxide, thereby enhancing the rate of oxygen decomposition. the increased amount of oxygenfree radicals produced thus enhances the release of stain-containing molecules and, therefore, results in enhanced whitening (2). (1)master student. department of conservative dentistry. college of dentistry, university of baghdad. (2)professor. department of conservative dentistry. college of dentistry, university of baghdad tooth-colored restorative materials, especially composite resin, have become an important part of modern dentistry. use of this material has recently increased because of consumer demands for esthetic restorations (3). newly developed composites with different matrix types, such as siloranes and filler types such as nano composites are used in clinical practice more often than hybrids (3). the consequences of bleaching of resin-based materials can vary according to resin and bleaching gel compositions, frequency and duration of exposure (1). alterations in microhardness and roughness are commonly used to analyze the possible negative effects of bleaching products (4). an increase in superficial roughness is clinically relevant, and irrespective of etiological factor, increase in roughness results in accumulation of food residues and formation of biofilms, leading to periodontal tissue disease (1). materials and methods four different composite resins that differ in their filler and resin content were selected: filtek p90,3m espe, a silorane based composite, filtekz250,3m espe, microhybrid composite, z350xt, 3m espe, nanofilled (nanoclusters) composite and z250xt, 3m espe, nanohybrid composite. j bagh college dentistry vol. 26(2), june 2014 the effect of in ssup up restorative dentistry 25 eighty circular samples were prepared, 20 samples for each of the four materials , by using teflon molds with a circular hole, 2 mm in thickness and 10 mm in diameter, were fabricated(5,6). the color corresponding to shade a3 was used for each material (3). the teflon mold was positioned on a glass slide. after inserting the materials into the teflon mold, a transparent plastic matrix strip was put over them and a glass slide was secured as seen in (figuer1) in order to flatten the surface and to prevent the formation of oxygen-inhibited layer on the surface of the samples (7).a (200 gm) pressure has been applied for 1min. to expel excess material from the mold and to reduce voids (7). the resin composites were cured by using a light-curing unit (qd,uk) at an intensity of 450 mw/cm2 which was verified before polymerization by using a radiometer (8). every sample was light cured for 80s in 2 steps (40 for each side) (3). figure1: securing the mold with glass slide the samples were polished with medium, fine, and superfine disks (soflex, 3m espe, st. paul, mn, usa) on a slow hand piece, in accordance with the manufacturer’s instructions (3, 6). after polishing, the samples were cleaned with distilled water and then the samples were put in ultrasonic cleaner for 2 minutes to remove any surface debris (3). a mark was made on the side that will be untreated (unbleached) of each sample to identify the surface type (1). all samples were stored in distilled water at room temperature for 24h before the initiation of any procedure. all samples were then divided into 8 test groups (n=10). ten samples of each of the 4 different resin composite samples were selected for baseline surface roughness measurements (with the portable surface profilometer) and surface micro hardness tests (using digital vickers instrument) as control groups (3). and 10 samples of each of the 4 materials were subjected to superficial treatment (bleaching using sdi pola office + 37.5hydrogen peroxide) and then doing the surface roughness and micro hardness tests. bleaching procedure the appropriate bleaching procedures were performed on the top of the unmarked surfaces of the samples of the test groups (3). the bleaching agent was applied over the surface of each specimen or sample, the entire surface must be covered with adequate amount of bleach and that is 0.2cc for every sample (every 1cc is enough for 5 samples). figure 2: putting the bleaching on the sample. the groups were treated with bleaching agent (37.5% hydrogen peroxide sdi pola office +), and with the use of beyond halogen emitting light (beyond, usa). for 45minutes each time (every 15 minute the old material was removed with the use of distilled water and we put a new bleaching coat). (6), at intervals of one week 1st and 7th day for totally 90 minutes for all the treatment period (3). at the end of every bleaching procedure, the treated specimens were washed, under flowing distilled water and then the samples put in ultrasonic cleaner for 2 minutes (3) to remove any remnant of the bleaching material. then they were placed in fresh distilled water until the next application. the distilled water was replaced every day (3). figure 3: enhancing the bleaching with beyond device. surface roughness measurements for surface roughness measurements, the specimens were examined by portable roughness tester device (tr220 portable roughnesstester (beijing time high technology ltd.). for each sample of all the groups, three randomized readings were performed on the challenged j bagh college dentistry vol. 26(2), june 2014 the effect of in ssup up restorative dentistry 26 surfaces after and before bleaching protocol. margins and visible irregularities were avoided (1) .after the three readings, the mean surface roughness values were obtained for each sample (9) microhardness measurements for micro hardness measurement, the control and the bleached groups (after finishing of all and complete bleaching procedure), tested by the use the digital vht device (digital micro vickers hardness tester th714 (beijing time high technology ltd.). the specimens were blotted dry using clean gauze and positioned beneath the indenter of a microhardness tester (10). surface hardness of the specimens was measured with microhardness tester using a 100 g load and 15 s dwell time at room temperature (3).the diagonal length impressions were measured and the hardness number (h) was calculated immediately through the digital device. in each specimen, three indentations were made on the top surface, not closer than 1 mm to the adjacent indentations or the margins of the specimen(3), and an average value was determined as a single value for each specimen. microhardness was measured at 24 hours after polymerization (base line) and at the end of the bleaching regimens. results surface roughness the pre-bleaching surface roughness of the four composite materials results showed that group1 (a) has the highest surface roughness (ra), followed by group4 (a) and then group3 (a) and then group 2 (a) which has the lowest (ra) mean value so the lowest surface roughness before bleaching. statistical analysis of data by using anova test for materials before bleaching showed that there is a highly significant differences between the surface roughness (ra) of the four composite materials (p=0.000). post bleaching surface roughness (ra) results showed that group 3(b) has the highest surface roughness value followed by group4(b) and followed by group2 (b)and then finally group1(b) which has the lowest mean surface roughness value (ra). statistical analysis of data by using anova test for post bleaching surface roughness (ra) values for all types of tested composites in this study revealed that there is no significant differences(p >0.05) in surface roughness. table1: means, standard deviation, standard error of surface roughness (ra) values in µm, and comparison of all tested materials before and after bleaching. mats descriptive statistics comparison mean s.d. s.e. t-test p-value g1 (a) 1.09 0.08 0.03 -13.52 0.000 ** (b) 1.58 0.08 0.02 g2 (a) 0.61 0.03 0.01 -15.72 0.000 ** (b) 1.74 0.21 0.07 g3 (a) 0.70 0.10 0.03 -16.59 0.000 ** (b) 1.77 0.15 0.05 g4 (a) 1.02 0.52 0.16 -3.69 0.005 ** (b) 1.75 0.37 0.12 figure 4: bar chart shows the differences between the means of surface roughness (ra) of the four composite materials before and after bleaching. j bagh college dentistry vol. 26(2), june 2014 the effect of in ssup up restorative dentistry 27 there is a highly significant increase in the surface roughness (ra) of all the tested materials after bleaching, that mean all the tested materials have an increase in their surface roughness after bleaching as seen (in table 1). microhardness the pre bleaching vickers hardness number (vhn) results showed that group 3(a) revealed the highest (vhn) mean value, followed by group2(a), then group 1(a), and finally group4(a) with the lowest (vhn) mean value, the least micro hardness. statistical analysis of data by using anova test before bleaching showed that there is a highly significant differences (p<0.001) in micro hardness of the tested four composite materials. the data revealed from anova test were analyzed by lsd test for all types of tested composites before bleaching. lsd test revealed that there was a highly significant difference (p<0.001) in vhn between all types of tested composite used in this study. the post bleaching (vhn) results showed that group2 (b) revealed the highest (vhn) mean value, followed by group3 (b), then group1 (b), and finally group4 (b) with the lowest (vhn) mean value. statistical analysis of data by using anova test after bleaching showed that there is a highly significant differences(p<0.001)in micro hardness of the tested four composite materials. the data revealed from anova test were analyzed by lsd test. lsd test revealed that there was a highly significant difference (p<0.001) in vhn between all types of tested composite used in this study. from that table, we can see that there is no significant difference in micro hardness value between group1(a) and group1(b), that mean bleaching have no or very little effect on microhardness of this material. for group2, there is a highly significant increase in microhardness after bleaching. for group3 and group4, there is a highly significant decrease in micro hardness after bleaching table 2: means, standard deviation, standard error of microhardness (vhn) values, and comparison of all tested materials before and after bleaching mat. descriptive statistics comparison mean s.d. s.e. t-test p-value g1 (a) 68.71 0.92 0.29 -0.97 0.36 (ns) (b) 69.19 0.99 0.31 g2 (a) 91 0.9 0.29 -17.55 0.000 ** (b) 96.28 0.76 0.24 g3 (a) 96.71 0.87 0.28 14.93 0.000 ** (b) 90.25 0.98 0.31 g4 (a) 45.81 0.79 0.25 9.53 0.000 ** (b) 43.19 0.72 0.23 figure 5: bar chart shows the differences between the means microhardness (vhn) of the four composite materials before and after bleaching. j bagh college dentistry vol. 26(2), june 2014 the effect of in ssup up restorative dentistry 28 discussion surface roughness all the four tested materials showed an increase in surface roughness with a nonsignificant differences between them and that may be due tothe oxidation process that occur in the organic matrix which can facilitate water absorption and lead to loss of particles so roughness is more affected by bleaching than hardness this finding agree with (1) who said that roughness seems to be more affected than microhardness. the results showed that post bleaching surface roughness (ra) for z250 has the highest increase in surface roughness value followed by z250xt then followed by silorane and then finally followed by z350xt which has the lowest increase in mean surface roughness value (ra). these results may be due to the difference in the chemical composition of the tested materials and this hypothesis agree with (9) who suggest that the increase in roughness could be as a result of loss of resinous matrix rather than load particle. according to this hypothesis z250 and z250xt affected more than the other tested materials as both of them contain bis-gma, udma, bis-ema. the resin technology of z250xt is based on the filtek z250 restorative resin, replacing some of the tegdma with pegdma (3m espe),so both of them has the same resin composition, studies have reported that (udma) and (bis-ema),which are contained in filtek z250 and z250xt, form fewer double bond, which result in a slightly softer matrix (11), and this softer matrix will cause debonding of the filler from the resin resulting in high rough surface. z350xt its resin is also affected but the presence of clusters protect the resin from degradation so the bleaching agent has lower effect than the other three materials. the addition of engineered nanoparticles to formulations containing nanoclusters reduces the interstitial spacing of the filler particles leading to higher filler loadings. the filled matrix (resin plus engineered nanoparticles) is harder and more wear resistant than resin alone. it has been noted that the largest particles present in the composites (clusters) provides a protective shoulder to the remaining resin matrix this finding agree with authors (12). the silorane has an intermediate effect as it is affected more than z350 and less than z250 and z250xt, and that’s due to its different monomer (hydrophobic) that is affected less than the methacrylate resin monomer. the inorganic content of resin composites however, offers resistance to bleaching. form, amount and distribution of fillers are all aspects that determine the clinical performance of these restorative materials agree with (13). microhardness for z250 there is a significant increase in micro hardness. in addition to the same reason said previously in surface roughness, that may be attributed to that the resin matrix undergo softening and removal by bleaching leaving heavily loaded filler surface with less matrix. these findings agree with (14) who found increase in hardness of micro hybrid resin after bleaching so he claimed that the active ingredients of bleaching can remove the surface resin layer and leave a rich of filler particles so a harder surface. for silorane there a highly significant decrease in surface microhardness (vhn) this result may be due to many reasons one of them is may be attributed to the effect of hydrogen proxide on the silorane resin, and that peroxide may affect the resin filler interface and cause filler matrix debonding. this may cause microscopic cracks, resulting in increased surface roughness and decrease hardness of silorane. the other reason is the filler to matrix ratio which plays an important role in the effect of bleaching agent on the composite resin. the filler weight and volume ratio determines this effect,as silorane has the lower filler loading between the tested materials so its matrix is easily subjected to bleaching deterioration. the organic matrix of filtek p90 is composed mainly by silorane resin and the inorganic particles are quartz and yttrium fluoride, 0.1–2 μm average 0.47 μm, silanetreated silica filler, ytterbium fluoride, 76%wt. 55%vol., so this material has less filler loading tthan the other tested materials and this finding agree with many authors (3,16). for z250 xt there is highly significant decrease in surface microhardness and this may be attributedto resin monomer, as the resin of z250xt is composed of bis-gma, udma, bisema, pegdma, and tegdma. bis-gma and tegdma are both hydrophilic monomers so the reduction in vhn values may be attributed to the swelling and hydrolytic degradation of the matrix leading to filler /matrix cracking, also the incorporation of tegdma in the resin result in an increase water uptake in bis-gma this finding agree with authors (17). hydrophilic groups such as the ethoxy group in tegdma are thought to show affinity with water molecule by hydrogen bonding to oxygen. these results agree with the findings of authors who found that the j bagh college dentistry vol. 26(2), june 2014 the effect of in ssup up restorative dentistry 29 microhardness decrease related to the structure of the resin matrix (18). for z350 xt there was no significant alteration in its microhardness and this finding agree with (3) who said that nanobased composites were affected less than the hybrids and silorane and also agree with authors (10) who said that nanocomposite samples showed no significant alteration (color and microhardness) after bleaching. thus, no replacement of restorations is required after bleaching. the nanofilled composite was developed for use in all areas of the mouth with high initial polish and superior polish retention (typical of microfills), as well as excellent mechanical properties suitable for high stress–bearing restorations (typical of hybrid composites). changes in the structure or composition of this restorative material may have provided more resistant surface against bleaching treatments. the composite resin filtek z350xt (3m espe) has a nanofilled composite has a very small particle size. this may be another reason why nanofilled with smaller filler size has the highest polishing and consequently, smaller effect from bleaching agents, and disagree with wang et al (1) who said the bleaching gels affected nanofilled and microhybrid composite resins. it has been noted that the largest particles present in the composites(clusters) provides a protective shoulder to the remaining resin matrix (10) due to the shorter inter-particle spacing (19). according to heavily loaded jorensen (20) reported that when the distance between neighbor filler particles is around 0.1 µm, it protects against matrix wear. references 1. wang l, francisconia lf attaa mt, santosb jr, padreb nc, alcides g, karen bp. effect of bleaching gels on surface roughness of nanofilled composite resins. european j dentistry 2011; 5: 95-9. 2. hafez r, ahmed d, yousry m, el-badrawyd w, elmowafye o. effect of in-office bleaching on color and surface roughness of composite restorative. european j dentistry 2010; 4:170-7. 3. atali pw, topba fb. the effect of different bleaching methods on the surface roughness and hardness of resin composites. j dentistry and oral hygiene 2011; 3(2): 10-17. 4. al-salehi sk, hatton pv, miller ca, mcleod c, joiner a. the effect of carbamide peroxide treatment on metal ion release from dental amalgam. dent mater 2006; 22:948-953. 5. malkonduö, yurdagüven h, say ec, kazazoğlu e, soyman m. effect of bleaching on microhardness of esthetic restorative materials. per dent 2011; 36(2):177-86. 6. alqahtani m. the effect of a 10% carbamide peroxide bleaching agent on the microhardness of four types of direct resin-based restorative materials. oper dent 2012; 23:737-81. 7. cristina j, christine mbw, palma r. micro-hardness of posterior composite resin at varying post irradiation time. j oral sci 2007; 15(4):77-80. 8. chimello dt, dibb rgp, corona sam, lara ehg. assessing wear and surface roughness of different composite resins after tooth brushing. mater resto 2009; 4(22): 12-34. 9. mendes r, rattacasoa b, fonsecal, garciab r, aguilarc fg, consanid s, carvalho f, souzae pp. bleaching agent action on color stability, surface roughness and microhardness of composites submitted to accelerated artificial aging. europ j dent 2011; 5:121-130. 10. silva costa sx, becker ab, de souza rastelli an, de castro monteiro loffredo l, de andrade mf, bagnato vs. effect of four bleaching regimens on color changes and microhardness of dental nanofilled composite. int j dent 2009; 313845:7 11. takahashi r, jin, jian, nikaido, toru, tagami, junji, hickel, reinhard, kunzelmann, karl-heinz. surface characterization of current composites after toothbrush abrasion. dental m j 2013; 6: 2079-6412. 12. sensi lnc, roulet j, marson fc. surface roughness and gloss of four composite resins as a function of polishing time. 2013; 22: 29-37. 13. akram s, ali abidi sy, ahmed s, meo aa a, qazi fr. effect of different irradiation times on microhardness and depth of cure of nanocomposite. journal of the college of physicians and surgeons pakistan 2011; 21(7): 411-4. 14. sharafeddin f, jamalipour gr. effects of 35% carbamide peroxide gel on surface roughness and hardness of composite resins. j dentistry (tehran) 2010; 1(7): 211-6. 15. hannig c, duong s, becker k, brunner k, kahler e, atin t. effect of bleaching on subsurface microhardness of composite and a polyacid modified composite. dent mater 2007; 23: 198–203. 16. hannig c, duong s, becker k, brunner k, kahler e, atin t . effect of bleaching on subsurface microhardness of composite and a polyacid modified composite. dent mater 2007; 23: 198–203. 17. festuccia m sc, garcia lfr, cruvinel dr. color stability, surface roughness and microhardness of composites submitted to mouthrinsing action. j appl oral sci 2012; 20(2): 2005. 18. topcu ft, sahinkesen g, yamanel k, erdemir u, oktay ea, ersahana s. influence of different drinks on the colour stability of dental resin composites. eur j dent 2009; 3(1): 50–6. 19. schwartz ji, soderholm kjm. effects of filler size, water and alcohol on hardness and laboratory wear of dental composites. acta odontol scand 2004; 62:102106. 20. jorensen kd. restorative resins: abrasions, mechanical properties. scand j dent res 1980; 88: 557-68. j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 71 correlation between streptococci mutans and salivary iga in relation to some oral parameters in saliva of children lamia i. sood, b.d.s, m.sc. (1) minan y. h. al-ezzy, b.d.s., m.sc. (1) ameena r. diajil, b.d.s, m.sc., ph.d. (2) abstract background: saliva plays an important role in oral health. several salivary proteins are involved in the antimicrobial defence mechanism and are able to eliminate or inhibit bacterial growth in the oral cavity. secretory iga (siga) is one of the principal antibodies present in saliva, could help oral immunity by preventing microbial adherence, neutralizing enzymes and toxins. the aim of this study was to investigate the relationship between salivary streptococcus mutans (sm) count and s iga in stimulated whole saliva in children with primary dentition compared to those with permanent teeth in relation to some oral hygiene parameters. material and methods: stimulated whole saliva was collected from 50 children (25 with primary dentation and 25 with permanent teeth). salivary flow rate and ph was measured. oral hygiene index (ohi) and gingival inflammation was assessed using classical method. s iga level was measured using an immunoassay kit and sm count was determined by culture media. results: mean salivary flow rate, ph and s iga were significantly higher among children with permanent teeth compared to those with primary dentition. compared to primary dentition, permanent dentition was associated with a significantly reduced mean plaque index, increased mean gingival index and reduced mean salivary sm count. although plaque index showed a statistically significant positive correlation with sm count, gingival index showed a weak negative correlation with bacterial count. s iga, ph and flow rate showed a statistically significant moderately strong negative correlation with bacterial count. conclusion: this study showed a clear correlation between count of sm in stimulated whole saliva and both siga and plaque index. keywords: mutants streptococci, salivary iga, salivary flow rate. (j bagh coll dentistry 2014; 26(1):71-79). introduction whole saliva as an external biological fluid, is frequently used an easily accessible and obtainable secretion with an interesting scientific and clinical potential. stimulated salivary secretion may be preferable as a test sample (1-3); it is more easily collected and less adversely affected by storage than unstimulated salivary secretion (4). whole saliva contains several antimicrobial components that mediate selective adhesion and colonization of sm on the tooth surfaces. agglutinins include mucins, glycoproteins, fibronectin, lysozyme and salivary immunoglobulin a (siga) promote agglutination of sm and enhance bacteria removal. this may inhibit sm adherence to saliva-coated hydroxyapatite and epithelial surfaces and neutralize sm enzymes and virulence factors (5-7). siga is one of the principal antibodies present in saliva which predominates in most external secretions (8). siga in whole saliva is the contributions from the minor and various major glands vary greatly according to the flow rate (9). (1)lecturer. department of pop, college of dentistry, university of al-ramadi. (2) lecturer. department of oral diagnosisoral medicine college of dentistry, university of baghdad. siga is produced by local plasma cells in the stroma of salivary glands and is transported through secretory epithelia by the polymeric ig receptor (membrane secretory component) (10). at least 95% of the iga normally appearing in saliva is produced by local plasma cells in the various salivary glands and transported into salivary fluids as siga dimers or larger polymers (10). it is the first line of host defence against pathogens which invade mucosal surfaces. siga antibodies could help oral immunity by preventing microbial adherence, neutralizing enzymes, toxins, and viruses; or by acting in synergy with other factors such as lysozyme and lactoferrin (11-13). local immunity and antibodies may be of prime importance in defence mechanisms against infection to oral mucosa. interaction between oral microbial flora and host response may affect the periodontal health status; periodontal disease is assumed to be associated with immunological reactions against the action of microorganisms in dental plaque (14). the concentration of siga is directly and positively correlated with the severity of periodontal inflammation (15). research on plaque formation has shown that children with primary dentition, after professional tooth cleaning, form less plaque than older subjects over different periods of observation (1618).this demonstrates that plaque formation rate is j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 72 low and may have the amount of established plaque over time (19). bacterial profiles change with disease states and differ between primary and secondary dentitions (20). children with primary dentition respond to plaque accumulation with less gingivitis than adults (16-18). in children, immunological system may be acting in the presence of gingival inflammation since periodontal disease is assumed to start in childhood in the form of gingivitis, reaching a peak close to puberty and then progressing to the typical and overt of periodontitis in adults. thus it would be of great interest to investigate the immunological defence mechanism during childhood with the advantage of longer survival time of the teeth and improving of general health condition physically and psychologically (21). material and methods 1. study population the study was conducted in al-ramadi city in the western division of iraq. the sample comprised of 50 children divided into two groups according to their dentition. the first group consist of 25 children with primary (deciduous) dentition aged 6-7 years and had been selected randomly from dome of the rock primary school in al-ramadi city. the second group of 25 children were with only permanent dentition, aged 12-years. in this study, all children were with no history of systemic disease and did not take any antimicrobial agents during the last two weeks prior to the study. children who had suffered from upper respiratory tract infection in the past one week were excluded from the study due to development of iga and lysozyme. all parents/guardians signed consent forms to allow their children to enrol into this study. 2. collection and processing of salivary samples under standard temperature and humidity conditions, children were comfortably seated and, after a few minutes of relaxation, they were trained to avoid swallowing saliva, stimulated whole saliva using a piece of arabic gum was collected from each child by expectoration into a sterile graduated test tube. all saliva samples were collected in the morning between 8.30 to 9.30 a m for 5 minutes, then the salivary flow rate was measured as millilitre per minute (ml/min)(22). the salivary ph was measured immediately using electronic ph meter then samples were put in ice container until transport to the laboratory. before collection of salivary sample, oral hygiene status of the children was determined by recording the oral hygiene index (ohi) using the classical methodology (23). following salivary sampling, the gingival inflammation was assessed by using the criteria of gingival index system (24). in the laboratory of baghdad teaching hospital, the biochemical analysis of salivary samples has been done. before analysis, salivary samples were divided into two portions; one for salivary iga estimation and the second was for sm counting. 3. counting of salivary mutants streptococci the viable count of bacteriaafter serial 10-fold dilutions of salivary sampleswas monitored using sterile normal saline, and immediately agitated for 30 seconds on a vortex mixer. using adjustable micropipette with disposable tips,0.1 ml of the dilution was taken and then spread in duplicate using a sterile microbiological glass spreader on the plates of mitis salivarius bacitracin agar (msba);a selective media for ms.then the agar plates were incubated both anaerobically in an anaerobic jar for 48 hours and aerobically for 24 hours at 37°c. identification of ms includes: a) colony morphology: the colony on msb agar was examined directly and under dissecting microscope (magnification ×15); it appears as a light blue in colourwith 1-2mm in diameter. b) morphology of the microbial cells: a colony was picked up from msb agar separately under sterilized condition and subjected to gram`s stain.ms cellsare gram positive, spherical or ovoid in shapewith raised or convex surface arranged in short or medium length. c) biochemical tests: bacterial colonies were picked up from msb agar under sterilized conditions using inoculating loop, inoculated in 10 ml of sterilized brain heart infusion broth (bhi-b) and incubated aerobically at 37°c for 18 hrs. then the following tests were conducted:  catalase production test: hydrogen peroxide 3% (h2o2) had been used to detect the activity of catalase enzyme production.  carbohydrate fermentation test: mannitol media was used to test the ability ofms to ferment the mannitol which was added in a concentration of 1% to the cystinetrypticase agar (cta) mannitol media. in biochemical tests, all colonies of sm were catalase negative and had the ability to ferment mannitol. a positive reaction is indicated by changing in the indicator colour from red to yellow by the formation of acid. after identification, microbial counts of ms were recorded by colony counter taking in consideration the dilution factor and expressed as colony forming unit multiplied by the dilution factor per millilitre saliva (cfu/ml). j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 73 4. estimation of total secretory salivary iga salivary samples were centrifuged at 1000 x g (xg: is a relative centrifugal force) for 15 minutes; the clear supernatant was aspirated by disposable micropipette and was then frozen at -20°c until thawed for the antibody assay(25). salivary immunoglobulin was determined using radial immuno diffusion plate (rid), immunoglobulin concentration was expressed in mg/dl (26). this technique involves immuno precipitation in agarose, between an antigen and its homologous antibody. it was performed by incorporating one of two immune reactants (usually antibody) uniformly throughout a layer of agarose gel, and then the other reactant (antigen) was introduced into the wells punched in the gel. antigen diffused radially out of the well into the surrounding gel-antibody mixture, and the visible ring of precipitation was formed where the antigen and antibody had reacted. a quantitative relationship dose exists between ring diameter and antigen concentration, while the precipitate is explaining, the ratio between ring diameter and antigen concentration logarithm is approximately linear. the procedure involved:  the plate was opened and left for five minutes at room temperature to allow any possible condensation to evaporate.  the well was filled with 5µl of saliva and the plate was closed tightly.  the plate was allowed to stay flat at room temperature until the precipitation ring reach its maximum possible size, which often required 48-72 hours of diffusion with the end point ofdiffusion was identified by sharp precipitation ring at the end of the incubation time. the diameter of the ring was measured by a lens and then the results were calculated using the reference values. statistical analysis statistical analyses were done using spss version 19 computer software (statistical package for social sciences). statistical significance of differences in mean for normally distributed parameter between two groups was assessed using the student’s t-test. p value less than 0.05 was considered statistically significant. the statistical significance, direction and strength of linear correlation between two quantitative normally distributed variables were measured by pearson’s linear correlation coefficient. a multiple linear regression model was used to study the net and independent effect of a set of explanatory variable on a quantitative outcome (dependent) variable. the model provides the following parameters: p-value (model): in order to generalize the results obtained, the model should be statistically significant. unstandardized partial regression coefficient: measures the amount of change expected in the dependent variable for each unit increase in the independent variable after adjusting for other explanatory variables included in the model. standardized regression coefficient: measures the relative importance of each independent variable. p-value for regression coefficient: reflects the statistical significance of the calculated partial regression coefficient of each explanatory variable included in the model. r squared (r2) (determination coefficient): measures the overall performance of the model since it reflects the amount of variation in the dependent variable explained by the model. the closer its value to 100% the better the model fit. cohen's d is an effect size test used to indicate the standardised difference between two means. it can be used for t-test and would be an appropriate accompaniment to inferential testing. results the results presented in this study were based on the analysis of a random sample of 25 children with permanent dentition (age =12 years) and 25 children with primary dentition (age =6-7 years). gender distribution was equal in the two groups. 1. salivary parameters as shown in table 1, the mean salivary flow rate was significantly higher among cases with permanent dentition (0.83 ml/min) compared to those with primary dentition (0.7 ml/min). permanent dentition is associated with a mean increase in salivary flow rate of 0.13 compared to the primary dentition with cohen’s d was 0.93 which reflect an effect size used to indicate the standardized difference between two means. the mean salivary ph was significantly higher among cases with permanent teeth (7.3) compared to those with primary dentition (6.6). permanent dentition is associated with a mean increase in salivary ph of 0.7 compared to the primary dentition with cohen’s d. was 1.72. the mean salivary iga was significantly higher among cases with permanent teeth (21.2) compared to those with primary teeth (18.2). permanent dentition is associated with a mean increase in salivary iga of 3 compared to the primary dentition. the effect of permanent dentition on the previously mentioned indices compared to those j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 74 with primary dentition were all evaluated as high effect, since its cohen’s d was higher than 0.8. the effect of permanent teeth was higher on salivary ph followed by salivary iga (cohen’s d=1.72 and 1.62 respectively), while it was lowest on salivary flow rate (cohen’s d=0.93). 2. oral health status as can be seen in table 2, the mean plaque index was significantly lower among children with permanent teeth (1.4) compared to those with primary dentition (1.7). permanent dentition is associated with a mean reduction in plaque index of 0.3 compared to primary dentition. this effect was a strong one (cohen’s d =-1.33). the mean gingival index was significantly higher among cases with permanent teeth (1.7) compared to those with primary teeth (1.5). permanent dentition is associated with a mean increase in gingival index of 0.2 compared to the primary dentition. this effect was a moderately strong effect (cohen’s d = 0.7). 3. mutans streptococci count in whole saliva the mean salivary count of ms was significantly lower among cases with permanent teeth (5.6 ± 4.1) compared to those with primary teeth (14 ± 4.44). permanent dentition is associated with a mean reduction in salivary bacterial count of 8.4x100 compared to the primary dentition. this effect was a strong one (cohen’s d =1.97), figure 1. a linear correlation coefficient was calculated between the ms count and selected quantitative variables such as salivary iga, salivary ph and salivary flow rate, showed a statistically significant moderately strong negative (inverse) linear correlation with bacterial count (r=-0.46,0.40 and -0.40 respectivelyp< 0.05). plaque index showed a statistically significant moderately strong positive linear correlation with bacterial count (r=0.43, p< 0.05). gingival index on the other hand had a weak and statistically non-significant negative linear correlation with bacterial count (r=-0.12, p=0.42). to explain the reduction observed in count of cariogenic bacteria (ms)in cases with permanent dentition as compared to children with primary dentition, a multiple linear regression modeling was performed in the overall sample (n=50) with ms count was used as the dependent (response) variable. two models were used to account for the confounding effect of salivary flow rate on salivary iga. in the first model, three explanatory variables were adjusted for (salivary ph, plaque index and gingival index to show the net and independent protective effect of salivary iga on bacterial count. the model was statistically significant and able to explain 34% of variation in the response variable (bacterial count). after adjusting for the possible confounding effect of salivary ph, plaque index and gingival index, it was found that for each unit increase in salivary iga the bacterial count is expected to significantly decrease by 0.77 (x100). for each unit increase in salivary ph the bacterial count is expected to decrease by 1.6 (x100) after adjusting for the remaining explanatory (independent) variables included in the model. this effect was however not significant statistically. for each unit increase in plaque index the bacterial count is expected to significantly increase by 7.1 (x100) after adjusting for the remaining explanatory (independent) variables included in the model, table 3. in the same way for each unit increase in gingival index the bacterial count is expected to increase by 0.6 (x100) after adjusting for the remaining explanatory (independent) variables included in the model. this effect was however statistically nonsignificant. in this model plaque index had the strongest effect on bacterial count followed by salivary iga (as shown by the high value of standardized coefficients). salivary ph and gingival index had a much less important effect in deciding the observed ms count (p-value was non-significant for both; table 3). in the second model, salivary flow rate was introduced as the fifth independent variable to model-i. the resulting model was also statistically significant and able to explain 40% of the observed variation in the dependent variable (bacterial count). salivary flow rate took over the place of salivary iga in the model. it ranked second in its importance after plaque index (as shown by its standardized coefficient). for each unit increase in salivary flow rate the bacterial count is expected to significantly decrease by 12.7 (x100) after adjusting for the remaining explanatory variables included in the model. the role of salivary iga in deciding the bacterial count ranked third now and it lost its statistical significance. for each unit increase in salivary iga the bacterial count is expected to decrease by 0.37 (x100) after adjusting for the remaining explanatory variables included in the model, table 4. discussion in this study, investigation of salivary flow rate, ph, siga and ms count in the stimulated whole saliva, beside some oral health status parameters were performed in a group of children having primary teeth and a group with permanent teeth for assessment, evaluation and comparison purposes. j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 75 the present study showed that the mean salivary flow rate and ph was significantly higher among children with permanent teeth compared to those with primary dentition. this finding agrees with previous studies showed an increase in whole salivary flow rate with age (27-29). this may be attributed to the process of salivary gland maturation associated with age growing of child which may favour the higher values of salivary ph found in this group of children. the current study showed that permanent dentition is associated with reduction in the mean plaque index and higher mean gingival index compared to primary dentition. while primary dentition exhibited higher plaque index and lower gingival index compared to permanent teeth. according to mackler and crawford, the most acceptable explanation for the absence of clinical gingivitis in cases is the innate resistance and presence or absence of host response in this age group (30). permanent dentition is associated with lower salivary sm count compared to primary dentition. in this study, there is no relation between gingival inflammation, amount of plaque and sm count in the whole saliva of both groups of children. this is consistent with a study that investigated the correlation between salivary sm counts and both of plaque amount and gingival inflammation in school children; which found that there was no association between counts' of sm in saliva with plaque amount and gingival inflammation (31). the higher values of both plaque index and salivary sm in children with primary teeth in the present study may be due to lack of good personal practices of oral hygiene in this age group of children. oral hygiene in lower age children with primary teeth, by the time they should be more responsible for maintaining good oral hygiene status (32). this group of children compared to those with permanent teeth have different dietary habits include frequent sugar intake, fruit juices, sweet solids and drinks favours the growth of bacteria such ms (33). the high percentage of salivary ms in children with primary teeth in the current study may be related to the lower salivary flow rate and ph (34) in those children, affecting the accumulation and maturation of biofilm at the gingival margin (29). this may support the results of this study of lower salivary flow rate and ph in relation to high ms count. secretory iga is the main immunoglobulin in salivary fluid. data provided evidence that children have salivary iga antibodies shortly after birth, which might influence the establishment of the oral microbiota (35). biologically, salivary siga provides the first line of immune defence in the oral environment, responsible for inhibiting the bacterial adhesion on the enamel and epithelial cells and may be acting in synergy with other defence mechanisms to inactive bacterial enzymes/toxins and activating the complement; it is partially involved in cell-mediated immune responses (36-37). in the present study, permanent dentition is associated with an increase level of siga compared to primary dentition. this is consistent with the view of increasedsalivary iga concentrations with age which has been reported by previous study (38) and might reflect a developing immune response in the growing child (39). according to thaweboon et al., siga has a parabolic relationship with age; at birth siga levels are undetectable but with age there is a consistent increase in the levels (40). this finding supports the current study finding which emphasizes the relationship between age and siga concentration. previous studies have demonstrated that salivary iga, ph and flow rate play an important role in the oral mucosal defence mechanisms (41 and 42).this study showed an increased level of both flow rate and s iga concentration in children with permanent teeth. however, this is inconsistent with the findings of kugler et al (1992) who demonstrated a significant inverse relationship between salivary flow rate and salivary iga concentration (38). siga may inhibit the attachment of oral streptococci to teeth and can enhance lactoferrin, peroxidases and lysozyme activities in saliva, subsequently reducing sm colonization (43).this may confirm the findings of this study which showed a strong negative correlation between sm count and siga level. for the purpose of confirmation and more explanation of the current study findings, multiple linear regression analysis was performed using overall study samples; with sm count considered as dependant variable. in the first model, adjustment for the salivary ph, plaque and gingival index was generated to study the effect of siga on sm count. regression analysis showed that the most significant and strongest effect on sm count was for plaque index followed by siga level. for each unite increase in plaque index the sm count is expected to increase 7-time (7.1 x100), whilst a significant reduction in sm count to 77% (0.77 x100) was seen when there is a unite increase in siga concentration. the study finding of significantly positive correlation between plaque index and sm count is confirmed by above interpretation, which is also supported by other studies which found that siga may help maintain disease-free oral cavity by limiting microbial adherence to epithelial j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 76 tissue/tooth surfaces via neutralizing virulence factors and also by preventing the penetration of antigens into the oral mucosa (40). furthermore, higher levels of microbial antigenic loads present in the oral cavity of these children probably increases the immune reaction which leads to high levels of antibody production (40). in the second model, salivary flow rate was introduced as an independent variable and ranked second after plaque index to influence the bacterial count. for each unite increase in salivary flow rate, sm count is expected to increase by around 13 time (12.7 x100). there are many factors that can influence the concentration of siga(38). salivary flow rate is considered as an important factor in determining the concentration of siga(44) and it is controlled by several factors, such as food ingestion, sensory stimulation, drugs, smoking, body positioning, stress and degree of hydration. dietary factors, daily mood, and intense physical activity may also affect siga concentration (45,46). it is worth noting that comparison of all results with other studies was not possible. this may be due to disparity between results which could be attributed to either differences in study population related to dietary pattern, oral hygiene practice and genetic factors or to the technique of saliva collection and laboratorial tests used. in conclusion this study found that: • children with permanent dentition exhibited a higher salivary flow rate, ph and siga levels compared to those with primary teeth. • children with permanent dentition showed lower plaque index and higher gingival index compared to those with primary teeth. • sm count was lower in cases with permanent teeth compared to those with primary teeth. • a negative correlation was found between sm count and each of flow rate, ph and siga levels. 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(ivsl). 36. brandtzaeg p. synthesis and secretion of human salivary immunoglobulins. in: garrett jr, ekstrom j, anderson lc. glandular mechanisms of salivary secretion. london: karger 1998; 10: 167-99. 37. brandtzaeg p. the mucosal b cell and its functions. in: brostoff j, challacombe sj (eds). food allergy and intolerance. 2nd ed. london: saunders elsevier science; 2002. p. 127-71. 38. kugler j, hess m, haake d. secretion of salivary immunoglobulin a in relation to age, saliva flow, mood states, secretion of albumin, cortisol, and catecholamines in saliva. j clinimmunol 1992; 12(1): 45-9 39. sonesson m, hamberg k, wallengren ml, matsson l, ericson d. salivary iga in minor-gland saliva of children, adolescents, and young adults. eur j oral sci 2011; 119(1):15-20. 40. thaweboon s, thaweboon b, nakornchai s, jitmaitree s. salivary secretory iga, ph, flow rates, mutans streptococci and candida in children with rampant caries. southeast asian j trop med public health 2008; 39(5): 893-9. 41. barr-agholme m, dahllof g, modeer t, engstrom pe, engstrom gn. periodontal conditions and salivary immunoglobulins in individuals with down’s syndrome. j periodontol 1998; 69: 119-23. 42. benderli y, erdilek d, koray f, telci a, turan n. the relation between salivary iga and caries in renal transplant patients. oral surg oral med oral pathol oral radiol endod 2000; 89: 58893. 43. hajishengallis g, nikolova e, russell mw.inhibition of streptococcus mutans adherence to saliva-coated hydroxyapatite by human secretory immunoglobulin a (s-iga) antibodies to cell surface protein antigen i/ii: reversal by iga1 protease cleavage. infect immun 1992; 60: 5057–64. 44. dawes c. considerations in the development of diagnostic tests on saliva. ann ny acad sci 1993; 694: 265-9. 45. watson rr, mcmurray dn, martin p, reyes ma. effect of age, malnutrition and renutrition onfree secretory component and iga in secretions. am j clin nutr 1985; 42: 281-8. 46. stone aa, cox ds, valdimarsdottir h, jandorf l, neale jm. evidence that secretory iga antibody is associated with daily mood. j pers soc psychol 1987; 52: 988-93. j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 78 table 1: mean differences, range and size effect (cohen's d) of selected explanatory variables. children with primary dentition (age =6-7; n=25) children with permanent dentition (age =12; n=25) p value (t-test) 1. salivary flow rate 0.003 range (0.59 0.83) (0.68 1.46) mean 0.7 0.83 sd 0.061 0.189 se 0.012 0.038 difference in mean 0.13 cohen's d 0.93 2. salivary ph <0.001 range (5.5 7.3) (7 7.7) mean 6.6 7.3 sd 0.53 0.22 se 0.11 0.04 difference in mean 0.7 cohen's d 1.72 3. salivary iga <0.001 range (15.7 21) (16.7 25.1) mean 18.2 21.2 sd 1.6 2.08 se 0.32 0.42 difference in mean 3 cohen's d 1.62 table 2: the difference in the mean of two secondary outcome variables; plaque and gingival index. primary dentition permanent dentition p-value (t-test) 1. plaque index <0.001 range (1.4 2.2) (1 2) mean 1.7 1.4 sd 0.2 0.25 se 0.04 0.05 difference in mean 0.3 cohen's d -1.33 2. gingival index range (0.8 1.8) (1.2 2.3) 0.01 mean 1.5 1.7 sd 0.3 0.27 se 0.06 0.05 difference in mean 0.2 cohen's d 0.7 table 3: multiple linear regression model with ms bacterial count (x 100) as the dependent variable model-i partial regression coefficient p-value unstandardized standardized (constant) 24.3 0.05 [ns] salivary ph -1.6 -0.141 0.36 [ns] plaque index 7.1 0.328 0.014 gingival index 0.6 0.031 0.81 [ns] salivary iga -0.77 -0.307 0.045 ns=non-significant, r2=0.34 p-value (mode l) <0.001 j bagh college dentistry vol. 26(1), march 2014 correlation between oral diagnosis 79 table 4: multiple linear regression model with ms bacterial count (x 100) as the dependent variable. model-ii partial regression coefficient p-value unstandardized standardized (constant) 20.5 0.09 [ns] salivary ph -1.3 -0.115 0.44 [ns] plaque index 8.8 0.402 0.003 gingival index 1.3 0.066 0.59 [ns] salivary iga -0.37 -0.146 0.36 [ns] salivary flow rate -12.7 -0.325 0.024 r2=0.40 p-value (mode ii) <0.001 ns=non-significant figure 1: dot diagram with error bars showing the difference in mean (with its 95% confidence interval) primary outcome variable (salivary ms bacterial count). difference in mean = 8.4 cohen's d = -1.97 farah.doc j bagh college dentistry vol. 26(4), december 2014 evaluation of oral diagnosis 116 evaluation of maxillary sinus septal type and height in partially edentulous maxilla using spiral computed tomography farah a. hadi, b.d.s., m.sc. (1) areej a. najm, b.d.s., m.sc. (1) mohammed a. kadhum, b.d.s., m.sc. (1) abstract background: the presence of anatomic variations within the maxillary sinus such as septa has been reported to increase the risk of sinus membrane perforation during sinus elevation procedure for implant placement. this study aimed to measure the septal heights and correlate it with different types of septa. material and methods: thirty patients (15 males and 15 females) with partially edentulous maxillae and mean age (35) years were enrolled in this study. sixty sinuses scanned with spiral multislice computed tompgraphy, septal height measured after evaluation of septal type whether it was primary or secondary. results: the results showed that 72.5 % of the septa detected were primary and this is statistically significant when compared with the percentage of secondary type (27.5%). there was a statistically significant difference in the height of septa between the two types, and the primary septa were higher. there was no significant difference between septal type and sex. conclusions: a sound knowledge of maxillary sinus anatomy and anatomic variations such as septa is essential to prevent complication during surgical interventions involving this region. key words: maxillary sinus septa, ct, septal height, septal type. (j bagh coll dentistry 2014; 26(4):116-119). تھدف ھذه الدراسة إلى قیاس . ظھور االختالفات التشریحیة داخل الجیوب األنفیة مثل الحاجز تتسبب في زیادة خطورة ثقب غشاء الجیب االنفي خالل عملیة زرع االسنان :الخالصة .ارتفاع الحاجز داخل الجیوب االنفیة وربط ذلك المستوى مع االنواع المختلفة للحواجز تم , جیب انفي مسح وفحص باستخدام المفراس الحلزوني 60,سنة خضعوا للدراسة 35ذوي فك ادرد جزئیا ومتوسط عمر ) إناث 15ذكور و 15(ثالثون مریضا :المواد والطریقة .قیاس ارتفاع الحاجز داخل الجیب االنفي بعد تحدید نوع الحاجز ان كان اولي او ثانوي وجدت فروق ذات داللة احصائیة في %. . 27,5ت من النوع االولي وكان الفرق ذو داللة احصائیة عند مقارنتھ مع نسبة النوع الثانوي من الحواجز التي وجدت كان% 72,5: النتائج .سینلم یوجد فرق احصائي بین نوع الحاجز او ارتفاعھ بین الجن. ارتفاع الحاجز بین النوعین االولي والثانوي حیث كان االرتفاع اكبر في النوع االولي . الجراحیة في ھذه المنطقةالمعرفة السلیمة بتشریح الجیوب االنفیة واالختالفات التشریحة مثل حاجز الجیب االنفي یعد امر ضروري لمنع المضاعفات اثناء التدخالت : االستنتاج introduction dental implants have become very commonly used tools for the rehabilitation of partial and total lack of tooth. after the loss of molar and premolar teeth, a serious resorption affect the amount of vertical bone occurs with the increasedosteoclastic activity in schneiderian membrane, at the maxillary posterior region (1). maxillary sinuses (ms) are facial pyramidal cavities with thin walls corresponding to the orbital, alveolar, facial, and infratemporal aspects of the maxilla. the size, shape, and wall thickness of this anatomic structure vary from one individual to another (2, 3). some maxillary sinuses present septa; the septa of the maxillary sinuses are bony crests inside the sinus (4). they were first mentioned in a detailed description of maxillary sinus anatomy by underwood in 1910 (5) as a consequence, are referred to as underwood’s septa. the etiology of maxillary septa has been hypothesized by several authors. underwood (5) described septa as arising between areas of 2 adjacent teeth and located in 3 specific sections (anterior, middle, and posterior) of the sinus floor; these 3 sections correspond to 3 defined periods of tooth activity, which are separated from each other by intervals of time. (1)assistant lecturer, department of oral diagnosis, college of dentistry, university of baghdad neivert (6) proposed that septa were derived from the finger-like projections produced by the embryologic out-pouching of the ethmoid infundibulum. moreover, krenmair et al (7) classified septa into primary (which arise from the development of the maxilla) and secondary (which arise from irregular pneumatization of the maxillary sinus floor after tooth loss) and hypothesized that, as teeth are gradually lost, atrophy begins at different times in different regions.the same was stated by dakhli etal (8), etiologically, antral septa constitute congenital and acquired malformation. congenital septa also referred to as “primary septa”, can develop in all maxillary sinus regions and evolve during the growth of the middle part of the face, while the atrophy of the maxillary alveolar process proceeded irregularly in different regions, leaving bony “crests” on the maxillary sinus floor, also known as “secondary septa”, which can be considered the result of tooth loss and atrophy (4). radiographic identification of these structures is important, since the design of the lateral window during sinus lift procedures is based on the presence and size of maxillary sinus septa (9). studies indicate that ct scans are more reliable than panoramic radiographs in the preoperative analysis. today, ct can be j bagh college dentistry vol. 26(4), december 2014 evaluation of oral diagnosis 117 performed in axial and coronal planes with 3dimensional views for diagnosis and treatment of this region, the 3-dimensional ct avoids the superimposition and problems due to magnification and offers to visualize the craniofacial structures with more precision than the 2-dimensional conventional methods (10). the aims of the study was to measure maxillary sinus septal height and correlate it with different types of septa to offer the clinician, through an accurate investigation of the anatomy of the maxillary sinus septa, the tools to carry out sinus-lift procedures under safe conditions. materials and methods thirty patients (15 males and 15 females) with partially edentulous maxillae with age ranged from (20-50) years attended the maxillofacial department at al-karkh general hospital in baghdad city who admitted to have spiral ct scan for the brain and paranasal sinuses for different diagnostic purposes and for dental implant planning. sixty maxillary sinuses have been included in the study; any patients who had previously maxillary sinus surgery or having a pathological condition were not included in the study. spiral ct scans for (right & left) maxillary sinuses were taken for each patient. the information obtained was assessed in the (axial and sagittal) sections that may be further manipulated by rotation about any axis to display the septa of maxillary sinus from many angles. this multislice ct scan images were used to analysis of septa type at floor position whether primary or secondary. then measurement of septal height in millimeters (mm) was made from the base of septum to the highest point and correlates it with the two types of septa, as shown in figure 1. results in this tomographic study 30 patients (60 sinuses) were evaluated, 62 septa were detected (40 % single and bilateral, 36.6 % single and unilateral while 23.4 % were multiple septa). a closer examination revealed 72.5 % of septa located superior to a maxillary tooth (primary septa) and 27.5 % of septa located superior to an edentulous ridge (secondary septa) as shown in table 1. the relation between septal type and sex, the prevalence of primary septa was higher in female; while the secondary type was higher in male as shown in figure 2. the mean height of primary septa was 9.3 mm (sd 4.9; range 3.5-20.3 mm), where as the mean height of secondary type was 6.7 mm (sd 3.09; range 2-13.8 mm). the details were reported in table 2. table 1: number and percentage of maxillary sinus septal types in the study sample septal type male female total pvalue n % n % n % primary 15 57.6 30 83.3 45 72.5 0.04 s secondary 11 42.4 6 16.7 17 27.5 total 26 100 36 100 62 100 table 2: maxillary sinus septal height measurements (mm) compared to septal type septal type septal height pvalue mean sd se range up 95% conf.limit low 95% conf.limit primary 9.3 4.9 1.2 3.5 20.3 11.9 6.8 0.01 s secondary 6.7 3.09 0.4 2 13.8 7.6 5.8 total 8 3.9 0.8 2.75 17.0 9.7 6.3 figure 1: measurement of maxillary sinus septal height in sagittal section ct. j bagh college dentistry vol. 26(4), december 2014 evaluation of oral diagnosis 118 relation between septal type and gender 0 5 10 15 20 25 30 35 male gender s ep ta l t yp e primary secondary female figure 2: distribution of septal type in relation to sex discussion many authors have reported the presence of ms septa and their relevance to surgical procedures. this anatomic variation was first described by underwood in 1910 (5). the presence of ms septa can be detected in panoramic radiographs. however, ct and cbct are definitely the preferred imaging techniques for the assessment of this anatomic variation. septa appear to develop in either of 2 ways, either primary (developmental) or secondary as a result of tooth loss and remnant interseptal bone. tooth loss and pneumatization adjacent to either a primary or secondary septum may also exaggerate the height or size of a septum. it is impossible to label a septum located apical to an edentulous ridge as primary or secondary without a radiographic history of the sinus in question. thus, it can be stated that septa located apical to dentate regions are primary (developmental), and septa located apical to an edentulous region can be either primary or secondary. in 1910 underwood (5) examined 45 dried skulls and reported a mean height of septa between 6.4 and 12.7 mm. ulm et al. (11) considered the existence of septa if they measured more than 2.5 mm.; this criterion has been followed by several groups of authors (12,13,14). ulm et al. (11) conducted an observational study on 41 patients and reported a mean height of septa was 7.9 mm. plata et al (12) conducted ct scan analysis of 312 sinus (patients age range 24-86 y), and assessed each septa at three points: the mean height for the lateral aspect was 3.5 mm; 5.9 mm for the central aspect; and 7.6 mm for the medial one. kim et al. (13) used the same method as plata et al. (12), and reported mean heights of 1.6 mm in the lateral aspect, of 3.5 mm in the middle aspect and 5.5 in the medial one. some of the previously mentioned studies were agreed with the results of this study and the others were not, there were two possible explanations can be that all the septa were included, unlike kim et al. (13), who discounted septa below 2.5mm, and the precise nature of cts that enabled more accurate identification of septa. the reason why all septa were included was that even small septa can be a challenge for sinus floor elevation, especially for the inexperienced surgeon. plata et al. (12) and kim et al. (13) compared primary and secondary septa of partially edentulous patients, kim et al. (13) found significantly greater heights in primary septa, whereas plata et al. (12) found that primary septa were significantly shorter. the results of the current study agreed with kim et al.(13) , but differed from those reported by plata et al.(12) and this may be due to differences between methods of measurement, tools utilized to gather data, and variation among populations studied, in addition secondary septa formed after tooth loss and pneumatization of sinus floor that happened at various patients age depending on time of teeth lose and the age ranged included in plata study was greatly differd from those in the present study .gonzálezsantana et al. (14) used opg to study maxillary sinus septa and registered heights between 2.5 and 6 mm. this result was greatly differed from the result of the current study and this may be due to greater accuracy of ct and on the other hand opg was very limited and sometimes not reliable and failed to show septa and other anatomical landmarks, in addition to possibility of giving false negative results. in anatomic study conducted by rosano et al. (15), 20 antral septa examined and reported a mean height of 8.72 mm (sd, 4.26; range, 3.7-18.4 j bagh college dentistry vol. 26(4), december 2014 evaluation of oral diagnosis 119 mm). this result was confirmed with the result of the current study. as a conclusion, septa of various heights developed in all parts of maxillary sinus. primary septal was higher than secondary septa because it was developed early and continuous growth happened along the life time; therefore extensive evaluation with appropriate radiograph technique is required, ct scan imaging is today the preferred method for preoperative detection of septa and other anatomic variation in patients who are candidates for sinus surgery and implant procedure. references 1. damlar i, evlice b, kurt sn. dental volumetric tomographical evaluation of location and prevalence of maxillary sinus septa. cukurova medical j 2013; 38 (3): 467-74. 2. koymen r , gocmen-mas n, karacayli u, ortakoglu k, ozen t, yazici a. anatomic evaluation of maxillary sinus septa: surgery and radiology. clinical anatomy 2009; 22 (5): 563–70. 3. poleti m, fernandes l, oliveira-santos c, capelozza a, chinellato l, rubira-bullen l. case report: anatomical variation of the maxillary sinus in cone beam computed tomography. hindawi publishing co. case reports in dentistry 2014. 4. rosano g, taschieri s, gaudy j, lesmes d, del fabbro m. maxillary sinus septa: a cadaveric study. j oral maxillofac surg 2010; 6(8): 1360-4. 5. underwood as. an inquiry into the anatomy and pathology of the maxillary sinus. j anat physiol 1910; 4: 344-54. 6. neivert h. surgical anatomy of the maxillary sinus. laryngoscope1930; 40 (1):16-22. 7. krenmair g, ulm cw, lugmayr h. maxillary sinus septa: incidence, morphology and clinical implications. j craniomaxillofac surg 1997; 25: 261. 8. dakhli i, abdelsalam z, salem d, omar g. validity of tridimensional ct study of maxillary sinus reconstruction in potential implant site. cairo dental j 2009; 25(3): 329-36. 9. ferrín l, galán-gil s, rubio-serrano m, peñarrochadiago m, peñarrocha-oltra d. maxillary sinus septa: a systematic review. med oral patol oral cir bucal 2010; 15 (2): 383-6. 10. orhan k, seker b, aksoy s, bayindir h, berberoğlu a, seker e. cone beam ct evaluation of maxillary sinus septa prevalence, height, location and morphology in children and an adult population.med princ pract 2013; 22:47–53. 11. ulm cw, solar p, krennmiar g, matejka m, watzek g. incidence and suggested surgical management of septa in sinus lift procedures. int j oral maxillofac implants 1995; 10: 462-5. 12. plata d, hovey lr, peach cc, adler me. maxillary sinus septa: a 3dimensional computerized tomograhic scan analysis. j periodontol 2002; 17: 85460. 13. kim mj, jung uw, kim cs, kim kd, choi sh, kim ck. maxillary sinus septa: prevalence, height, location and morphology. a reformatted computed scan analysis. j periodontol 2006; 77: 903-8. 14. gonzalez h, penarrocha m, guarinos j, sorni m. a study of the septa in the maxillary sinuses and the subantral alveolar process in 30 patients. j oral implantol 2007; 33: 340-3. 15. rosano g, taschieri s, gaudy j, lesmes d, fabbro m. maxillary sinus septa: a cadaveric study. j oral maxillofac surg 2010; 4: 1360-4. j bagh college dentistry vol. 33(3), september 2021 the estimation of the 23 the estimation of the viable count of mutans streptococcus in waterpipe smokers and cigarette smokers ausama a fathallh (1), maha a mahmood (2) https://doi.org/10.26477/jbcd.v33i3.2950 abstract background: waterpipe and cigarette are two products of tobacco consumption; tobacco use has detrimental effects on the oral cavity. numerous studies around the world have reported a significant relationship between smoking and increase dental caries and viable count of cariogenic bacteria, materials and methods: unstimulated saliva was collected from 84 subjects and divided equally into three groups: waterpipe smokers, cigarette smokers, and non-smokers. all of the participants are adult male aged between 25-60 years; dental caries was measured by use dmft index, while s.mutans and s.sobrinus were isolated by using a selective medium sb 20m (sugar bacitracin-20 modified) agar results: the present study showed a significant (p≤0.01) higher dmft, dt, mt, and ft among cigarette smokers group than both waterpipe smokers and non-smokers groups. the viable count of s mutans was significantly (p≤0.01) higher in the cigarette smokers group followed by the waterpipe smokers group and then the non-smoker's group, while the viable count of s sobrinus showed no statistical differences (p>0.05) between groups. the correlation of dmft with s.mutans, and s sobrinus count were significantly positive (p ≤0.05) in the cigarette smokers group only. conclusion: dental caries increase in cigarette smokers, where the dmft and s mutans viable count are less affected by waterpipe than cigarette smoking. a positive correlation is found between dmft and mutans streptococcus count only in cigarette smokers keywords: waterpipe, tobacco, s.mutans, s sobrinus, sb 20m. (received: 9/7/2021, accepted: 8/8/2021) introduction tobacco is a product that grows commercially in many countries. studies suggest that tobacco's first use was by maya people in the center of america in the first centuries bc. with the migration of maya to the mississippi valley started spreading to the south of america. native americans afterward, portuguese and spanish navigators served to spread various kinds of tobacco to be used throughout the world, (1,2) another level of tobacco use started when cigarette had been invented; it fired this dramatic increase in tobacco using (3). there is a difference form of tobacco consuming either smoking like waterpipe, cigarette, non-smoking chewing tobacco like snuff /naswar (roasted and finely powdered for inhalation (1). one of the most common use and most favored product of tobacco is cigarette, more than six trillion cigarettes are produced annually and about one billion smokers consume these products in the world (4). (1) master student, department of dentistry, al-israa university college, baghdad, iraq. (2) professor, department of basic sciences, college of dentistry, university of baghdad. corresponding author's e-mail: drausamaalubaidi@gmail.com another type of tobacco consumption is waterpipe which has different designs according to regional and cultural reasons; it also has different names, narghile in east mediterranean countries like turkey and syria, shisha in egypt, and hookah in india (5). recently waterpipe tobacco usae is spreading rapidly worldwide, with reports of more youth being waterpipe users compared to adults. in many areas of the world (6), the highest prevalence of smoking waterpipe is in arab countries of africa, the eastern mediterranean plus southeast asia and rises in european countries. it appears higher among youth than adults (7,8). in the middle of the twenty century, widely read and admitted scientific reports decided that smoking is the major cause of lung cancer (9). evidence exhibits that the use of tobacco in all its types substantially raises the risk of premature death from many chronic diseases (10). smoking has many adverse effects on oral health in addition to the contribution in the development of lung cancer and cardiovascular disease. there is plenty of evidence that it has a strong impact on the mouth; it may develop some oral diseases such as periodontal disease, dental caries, oral candidosis, implant failure, oral precancer, and cancer (11). https://doi.org/10.26477/jbcd.v33i3.2950 j bagh college dentistry vol. 33(3), september 2021 the estimation of the 24 dental caries or decay can be defined as the most widely distributed infectious, chronic and multifactorial disease. it is the result of interactions over time between oral bacteria that produce acid, a substrate, that the bacteria can metabolize, and many host factors that include teeth and saliva (12). the mechanism of action of the caries process happens by the production of a weak acid by cariogenic bacteria such as streptococcus and lactobacillus, as a result of the fermentation process of carbohydrate which leads to a decrease in local ph below the critical value and demineralization of the tooth surface (13,14). studies have strong evidence that emphasizes this significant association between the degree of caries activity and the salivary levels of streptococcus mutans (15,16). s. mutans is considered as the main component of the oral microbiota and one of the key elements of the dental plaque. (17), although s.sobrinus is a minor component, s.mutans usually predominates; but both are causative pathogens of dental caries and strongly implicated in plaque or oral biofilm formation (18). mutans streptococci detection is typically dependent on selective media, growth on mitis salivarius agar (ms), colony morphology, and biochemical features (19). the sb-20m medium is also a selective medium that is efficient for the identification and direct morphological recognition of s mutans, s.sobrinus (20). in addition to their hazards to general health, tobacco use has detrimental effects on the oral cavity both soft and hard tissue, about half a million oral cancer recorded in 2002 around the world with tobacco as the main cause. a clear relationship was observed with periodontal disease, and also it is associated with the increase of dental caries and is considered as a risk factor (21). numerous epidemiological reports all around the world have recorded a near association between smoking and dental caries. in portugal, a study confirms smoking as a risk factor for tooth decay. further, avoiding exposure to smoking leads to a 7% reduction in caries occurrence. (22). research in scotland found that if a pregnant woman smokes cigarettes, her infant can have a higher prevalence of caries than a child born to a non-smoking mother (23). microbial analysis of saliva showed that there was a substantial increase in the microbial load of s.mutans among tobacco users which might increase the caries severity; however, the association between smoking and s.mutans growth is controversial. some research has revealed a positive relationship between smoking and s.mutans growth as nicotine in tobacco has been shown to enhance the adhesion of s.mutans to the acquired pellicle and increase biofilm formation and thus increase the incidence and severity of dental caries. (24,25). on the other hand, one recent study shows that tobacco consumers had fewer caries than healthy adults, which was contrary to several previous studies.(26) supposing that smoking tobacco helps to reduce caries, this was supported by the presence of a higher concentration of thiocyanate (scn). in the blood and saliva of the smoker, thiocyanate is a constituent of tobacco smoke which has caries inhibiting effect (27,28). materials and methods this comparative study consisted of 84 males aged between 25 to 60 years old. the study consisted of 56 smokers subjects divided into waterpipe smokers group (28), and cigarette smokers group (28), and 28 non-smoker subjects as a control group. the study included subjects who smoke more than five times weekly for waterpipe smokers, while more than 10 cigarettes daily for cigarette smokers, all those with systemic diseases, such as (diabetes mellitus, chronic heart disease), or taken antibiotics within the last 3 months; or had periodontal treatment during the last 6 months were excluded. oral examination of each subject was carried out following criteria recommended by world health organization, 2013 (29), the subjects were examined while seated on a dental chair. the clinical examination of dental caries was conducted using a dental explorer and mouth mirror. unstimulated saliva was collected from subjects in the early morning between 8-10 am. the subject was asked to avoid eating or drinking for three hours before the procedure of saliva collection, then asked to wash his mouth with distilled water for one minute and to relax for five minutes directly before starting saliva collection. subjects were also asked to spit saliva into the sterilized cups that possess graduations (30). j bagh college dentistry vol. 33(3), september 2021 the estimation of the 25 results table 1 :showed that the median values of dmft, dt, mt, and ft (8.0, 2.5, 1.0, 3.5 ) respectively were higher among cigarette smokers group than both waterpipe smokers and non-smokers groups; all these differences were statistically highly significant (p ≤ 0.01). although the median value of dt and mt were equal (1.5, 0.0) respectively in both the waterpipe smokers group and non-smokers group, the mean rank values of dt and mt were higher in the waterpipe group (38.018, 37.143), respectively than non-smokers group (35.78, 33.929) with a non-significant differences (p>0.05) between both groups as clarified by mann-whitney test. the median of dmft and ft were higher in the non-smoker's group (3.5, 1.0 respectively) than in waterpipe smokers group (3.0, 0.0), with a nonsignificant difference (p>0.05) in dmft, and statistically highly significant (p≤0.01) in ft. regarding the viable count of s.mutans results showed that median values of s.mutans calculated in (cfu/ml) were higher in the cigarette smokers group (23.00), followed by the waterpipe smokers group (12.50) and then non-smokers group (11.65). these differences were statistically highly significant (p≤0.01). mann-whitney test clarified that despite that the median value of colony count in the waterpipe group was higher than the nonsmoker's group, statistically there were no significant differences (p>0.05) between them. according to s.sobrinus viable count (cfu/ml), the results showed that mean rank values in the cigarette smokers group (47.732) have the higher value followed by the non-smoker's group (40.054) and waterpipe smokers group (39.714), but statistically, there were no significant differences (p>0.05). in table 2, results showed that the correlation of dmft with s.mutans and s.sobrinus viable count, was a weak positive correlation in the nonsmoker's group and the waterpipe smokers group, with a non-significant statistical difference (p>0.05), whereas in the cigarette smokers group the correlations was statistically significant. it was moderate positive with s.mutans count (p ≤0.01) and weak positive with s.sobrinus ( p ≤0.05). table 1: the differences between, waterpipe smokers, cigarette smokers and non-smokers groups considering dmft index and viable count of mutans streptococcus variables groups descriptive statistics group difference median mean rank kwh test p-value groups mann-whitney u test p-value dt control 1.5 35.786 9.362 0.009 control waterpipe 377 0.800 waterpipe 1.5 38.018 cigarette 219 0.004 cigarette 2.5 53.696 waterpipe cigarette 251.5 0.019 mt control 0 33.929 16.907 0.000 control waterpipe 364.5 0.587 waterpipe 0 37.143 cigarette 179.5 0.000 cigarette 1 56.429 waterpipe cigarette 214.5 0.002 ft control 1 39.964 32.945 0.000 control waterpipe 224.5 0.004 waterpipe 0 25.589 cigarette 153.5 0.000 cigarette 3.5 61.946 waterpipe cigarette 86 0.000 dmft control 3.5 32.750 33.633 0.000 control waterpipe 356 0.550 waterpipe 3 30.589 cigarette 83 0.000 cigarette 8 64.161 waterpipe cigarette 94.5 0.000 s.mutans count x 10 5 (cfu/ml) control 11.65 29.839 32.970 0.000 control waterpipe 355 0.543 waterpipe 12.50 33.696 cigarette 74.5 0.000 cigarette 23.00 63.964 waterpipe cigarette 108.5 0.000 s.sobrinus count x 10 5 (cfu/ml) control 4.00 40.054 1.954 0.376 control waterpipe 387 0.934 waterpipe 4,00 39.714 cigarette 318.5 0.226 cigarette 5.00 47.732 waterpipe cigarette 319 0.229 dmft= decay, missing, filling tooth, sfr= salivary flow rate, p ≤ 0.01 highly significant, p≤0.05 significant, p>0.05 non-significant j bagh college dentistry vol. 33(3), september 2021 the estimation of the 26 table 2: correlation of dmft index with s mutans, s sobrinus p≤ 0.01 highly significant, p≤0.05 significant, p>0.05 non-significant discussion although the oral cavity contains numerous types of microorganisms, the present study has chosen s.mutans and s.sobrinus as these two cariogenic bacteria are the most common dental pathogens responsible for the development of caries. in this study, sucrose-bacitracin, 20 modified (sb-20m) culture medium was used to culture the aforementioned bacteria, as a selective medium is reliable for detection and direct morphological differentiation of s.mutans and s.sobrinus. results showed that dental caries increased in cigarette smokers and that median values of dt, mt, ft and, dmft, were significantly higher among cigarette smokers than waterpipe smokers and non-smokers, these results were in agreement with the former studies (25, 31, 32) and could be due to smoking influences on saliva as it reduced the buffer capability, changing its chemical agent and bacterial components, as well as the existence of nicotine in tobacco which enhances the adhesion of s.mutans to the acquired pellicle and increases biofilm formation that increases the incidence of dental caries (33, 34). on the other hand, results also revealed that the median value of dt and mt were slightly higher in waterpipe group than the non-smokers but without significant differences. similarly, previous researches assumed that waterpipe smokers were more susceptible to the development of dental caries than non-smoker because of high scores of plaque and calculus indices (35,36), while ft was higher in control groups than waterpipe smokers in the present work. this result agrees with the results of sahib et al., (2018) (37). the present work showed that median of s mutans viable count (cfu/ml) in cigarette smokers group have the highest value followed by waterpipe smokers group and then non-smokers groups with significant differences and this may be explained by the effect of nicotine and tar which improves the growth and attachment of s. mutans (38,39). the result of the present study disagrees with another previous study that found that the number of s.mutans in the saliva is not related to the smoking status (40). furthermore, the current results showed that median values of s.sobrinus count in cigarette smokers group had the higher value followed by waterpipe smokers group and non-smokers groups but statistically there were no significant differences. this corresponds with the previous study which recorded higher counting levels of s.sobrinus in smokers than non-smokers (41). this slight increase in colony count of s sobrinus in cigarette smokers may be due to the same aforementioned reason that leads to an increase in s.mutans as both s.mutans and s. sobrinus share several traits and virulence factors (42). it can be concluded that waterpipe smokers are less affected by dental caries when compared with cigarette smokers. this could be due to the lower daily nicotine exposure which is equivalent to 10 cigarettes, for daily smoking and equal to 2 cigarettes per day in non-daily smoking (43). moreover, the addition of artificial flavoring; like honey, glycerin and other flavors in the preparation of moassel contributed to lowering the nicotine level of each gram of moassel (44). on the other hand, the correlation of dental caries with s.mutans and s.sobrinus revealed that the relationship of dmft with s.mutans count was positive non-significant in the non-smokers group and waterpipe smokers group, while it was significantly positive in the cigarette smokers group. this agrees with other previous studies which showed a positive association of caries scores with s.mutans (45-49), additionally, this study noted a positive nonsignificant relationship of dmft with s sobrinus count in non-smokers group and waterpipe smokers group, while it was positive significant in the cigarette smokers group, and this agree with a recent study (50). this positive correlation with s.mutans and s.sobrinus could be due to the role of mutans streptococcus in the initiation of dental caries as both of these bacteria are well-known primary cariogenic microorganisms associated with dental caries (51). variables dmft index control waterpipe cigarette s mutans 0.289 0.226 0.565 0.291 0.294 0.002 s sobrinus 0.094 0.054 0.385 0.633 0.783 0.043 j bagh college dentistry vol. 33(3), september 2021 the estimation of the 27 conclusion dental caries were affected by cigarette smoking more than waterpipe smoking, where dental caries and s.mutans viable count (cfu/ml) were significantly higher among cigarette smokers than waterpipe smokers or non-smokers. a cigarette smoker group revealed a significant positive association between dental caries with both s.mutans and s.sobrinus count. regarding the streptococcus sobrinus count, there were no significant differences between the three studied groups despite a slight increase in colony count of s.sobrinus in cigarette smokers. conflict of interest: none. references 1. slade j .. historical notes on tobacco. prog respir res ; 1997; 28 :1-11. 2. ren n, timko mp. aflp analysis of genetic polymorphism and evolutionary relationships among cultivated and wild nicotiana species. genome. 2001 aug 1;44(4):559-71. 3. tyrrell i. allan m. brandt. the cigarette century: the rise, fall, and deadly persistence of the product that defined america. new york: basic books. 2007 4. giovino ga, 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a review of the current evidence. nicotine tob res. 2007 oct 1;9(10):98794.. 44. chaouachi k. hookah (shisha, narghile) smoking and environmental tobacco smoke (ets). a critical review of the relevant literature and the public health consequences. int j environ res public health. 2009 feb;6(2):798-843. 45. loyola-rodriguez jp, martinez-martinez re, floresferreyra bi, et al. distribution of streptococcus mutans and streptococcus sobrinus in saliva of mexican preschool caries-free and caries-active children by microbial and molecular (pcr) assays. j clin pediatr dent. 2007 dec 1;32(2):121-6.. 46. pannu p, gambhir r, sujlana a. correlation between the salivary streptococcus mutans levels and dental caries experience in adult population of chandigarh, india. eur j dent. 2013 apr;7(02):191-5. 47. oda y, hayashi f, okada m. longitudinal study of dental caries incidence associated with streptococcus mutans and streptococcus sobrinus in patients with intellectual disabilities. bmc oral health. 2015 dec;15(1):1-5. 48. lee yj, kim ma, kim jg, et al. detection of streptococcus mutans in human saliva and plaque using selective media, polymerase chain reaction, and monoclonal antibodies. oral biol res 2019;43(2):121129 49. veena rl, nagarathna c.. correlation of streptococcus mutans and streptococcus sobrinus colonization with and without caries experience in preschool children. indian j dent res. 2020;31(1):7379 50. al-anbari a a, al-ani m a . the association between severity of dental caries and salivary immunoglobulins in asthmatic adult patients. indian journal of forensic medicine & toxicology. 2021; 15(1) :2446-2450 51. garcia ss, blackledge ms, michalek s, et al. targeting of streptococcus mutans biofilms by a novel small molecule prevents dental caries and preserves the oral microbiome. j dent res.. 2017 jul;96(7):807-14.. المستخلص والال النرجيلة ان خلفية: حيث ، التبغ استهالك من نوعان من سجائر العديد أفادت وقد ، الفم تجويف على ضارة آثار له التبغ تعاطي الدراسات حول العالم بوجود عالقة كبيرة بين التدخين وزيادة تسوس األسنان والعدد الحيوي للبكتيريا المسببة للتسوس ومدخني السجائر ركيلة ناال شخًصا وقسم بالتساوي إلى ثالث مجموعات من مدخني 84ب غير المحفز من المواد والطرق: تم جمع اللعا عاًما ، وتم قياس تسوس األسنان باستخدام 60-25وغير المدخنين ، جميع المشاركين هم من الذكور البالغين الذين تتراوح أعمارهم بين sb 20mباستخدام وسط انتقائي المكورات المسبحية الميوتنس و المكورات المسبحية السوبرينوس .تم عزل بينما ، dmftمؤشر j bagh college dentistry vol. 33(3), september 2021 the estimation of the 29 أظهرت النتي ارتفاعجة: الحالية مقارنة ft و mt و dt و dmft (p≤0.01).رامؤث االدراسة السجائر مدخني مجموعة بين أعلى في و (p≤0.01)كان العدد القابل للحياة من المكورات المسبحية الميوتنس مؤثر حيثركيلة وغير المدخنين.نبمجموعات مدخني اال المسبحية ثم مجموعة غير المدخنين ، بينما لم يظهر العدد الحيوي اللمكوراتركيلة ناال مجموعة مدخني السجائر تليها مجموعة مدخني ذات فروق و المكورات المسبحية الميوتنس و dmftكانت العالقة بين و (p>0.05) لة إحصائية بين المجموعاتدالالسوبرينوس في مجموعة مدخني السجائر فقط. (p ≤0.05) موجبة معنويا المكورات المسبحية السوبرينوس يلة من أقل تأثراً بالنرك المكورات المسبحية الميوتنسعدد و dmft الحيث : زيادة تسوس األسنان في مدخني السجائر ،االستنتاجات . وعدد العقديات الطافرة فقط في مدخني السجائر dmftعالقة إيجابية بين و يوجد تدخين السجائر ، creative articles published by journal of baghdad college of dentistry is licensed under a .commons attribution 4.0 international license https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ ghazwan.doc j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 28 evaluation of shear bond strength between thermosens as relining material and different denture base materials ghazwan adnan alkinani, b.d.s., m.sc. (1) abstract background: denture relining is the process of resurfacing of the tissue side of the ill fitting denture, the bond strength at the relining-denture base interface is most important for denture durability.the aim of present study was to evaluate the shear bond strength between the thermosens as relining material and different denture base materials that bonded by thermo fusing liquid. as this corrective procedureis the common chair side procedure in the dental clinic. material and method: sixty samples were prepared and divided into three main groups according to the type of denture base materials.group (a) referred to the heat cure acrylic samples which consisted of 20 samples. group (b) referred to the high impact acrylic samples which consisted of 20 samples. group (c) referred to the thermosens samples which consisted of 20 samples. all groups then subdivided into two groups; each one consists of 10 samples, according to the surface roughness: (a1, b1and c1 for groups with surface roughness and a2, b2 and c2for groups without surface roughness). each sample consisted of two similar parts represent the denture base material each part of the sample was designed with dimensions of (70mm x 12mm x 5mmlength, width and depth respectively) having a stopper of depth 3mm. one part of the sample was placed on the other in a manner thatleaving a space between them of dimensions (12mm x 12mm x 3mm length, width and depth respectively) to sandwich the relining material. results: the results showed that the thermosens samples had the highest value of shear bond strength followed by the high impact acrylic samples, then heat cure acrylic samples which had the lowest value of shear bond strength. the results of present study showed that rough samples had reducedshear bondstrength in comparison with the smooth samples of the same denture base material. key words: thermosens, thermo fusing liquid, shear bond strength. (j bagh coll dentistry 2014; 26(4):28-31). الخالصة كثر أھمیة بالنسبةلمتانة قاعدة الطقم ھي األتبطین طقم األسنان ھي عملیة اضافة طبقةالى سطح الطقم المواجھ النسجة الفم الساندة للطقم ، ان قوة االلتصاقبینمادة التبطین و مادة : خلفیة و ھذه العملیة التصحیحیة. ثیرمو فیوشنالھدف من الدراسة الحالیة ھو تقییم قوة االلتصاق بین مادة الثیرموسینس كمادة تبطین و مواد قاعدة طقم مختلةتم لصقھا بواسطة سائل ال. الطقم .الشائعة في عیادة األسنان ھي من العالجات بالحرارة التي تتكون تشیر الى عینات االكریلیك المعالج) a (المجموعة . تم إعداد ستین عینة و تنقسم إلى ثالث مجموعات رئیسیة وفقا لنوع مواد قاعدةالطقم : لالمواد و طریقة العم جمیع . عینة 20تشیر إلى عینات الثیرموسینس التي تتكون من ) c( المجموعة . عینة 20تشیر إلى عینات االكریلیك عالیة التاثیر التي تتكون من ) b( المجموعة . عینة 20من ، a2(تشیر الى مجموعات العینات ذات االسطح الخشنة و ) a1،c1 ,b1: (عینات ، وفقا لخشونة سطح العینة 10المجموعات تم تقسیمھا إلى مجموعتین ؛ تتكون كل مجموعة من b2 ,c2(تتكون كل عینة من جزأین متماثلین تمثل مادة قاعدة الطقم تم تصمیم كل جزء من العینة مع أبعاد . قیلةتشیر الى مجموعات العینات ذات االسطح الص)مم70x12 مم x5 مم xمم x12مم 12(یوضع جزء واحد من العینة على اآلخر بطریقة تترك مسافة بینھما لتملئ بمادة التبطینباألبعاد . مم 3مع وجود عتبة من ارتفاع)طول وعرض وارتفاع على التوالي ).مم طول وعرض وارتفاع على التوالي3 لج بالحرارة التي كانت أقل قیمة من قوة أظھرت النتائج أن عینات الثیرموسینس كانت أعلى قیمة لقوة االلتصاق تلیھا عینات االكریلیك عالیة التأثیر، ثم عینات االكریلیك المعا: النتائج .وة االلتصاق قلت فیالعینات ذات االسطح الخشنة بالمقارنة مع العینات ذات االسطح الصقیلة من نفس مادة قاعدة الطقم وأظھرت نتائج الدراسة أن ق. االلتصاق .وسائل الثیرموفیوشن و قوة االلتصاق الثیرموسینس:مفتاح الكلمات introduction the patients treated with removable dentures always suffer from ill fitting denture after period of denture service due to bone resorption that led to soft tissue contour change; this problem is treated by relining or rebasing the denture. a critical part of the complete denture service is maintenance of the adaptation of the denture bases to the mucosa covering the residual ridges (1). the tissue surfaces of intraoral prosthesis is necessary to be altered for proper fit and function due to change of soft tissue contours during prosthesis service, this may be achieved by relining (2). “relining is a process in which a film of plastic is added to the inside of the denture to obtain an improved fit with the denture bearing mucosa.”(3) the bonding between the denture base material and relining material is very sensitive technique that may led to microleakage at the denture base (1)assistant lecturer. department of prosthodontics, college of dentistry, university of baghdad relining interface then detachment of the relining material. the shear bond strength test is one of the most commonlyused methods to measure the bond strength at denture base-relining interface (4). the shear bond strength at the denture baserelining interface was improved by using triad bonding agents with triad relining materials (5). the present study was designed to evaluate the shear bond strength at denture base-relining interface by using the thermosens as relining material and (conventional heat cure acrylic, high impact heat cure acrylic and thermosens) as denture base materials with the use of thermofusing liquid as bonding agent then compare between them. materials and methods materials the materials that used in this research were summarized in table 1. j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 29 table 1. some of the materials used in the study samples grouping sixty samples were prepared and divided into three groups according to the type of denture base material. group (a) 20 samples were constructed from conventional heat cure acrylic.group (b) 20 samples were constructed from high impact heat cure acrylic. group (c) 20 samples were constructed from thermosens denture base material. then each group was subdivided according to the surface roughness into two groups: (1) 10 samples with surface roughness and (2) 10 samples without surface roughness. samples preparation each sample consisted of two similar parts ofdenture base material placed one on the other in a manner that kept the relining material sandwiched between the two parts of the sample. wax pattern design wax patterns were designed with dimensions of (70mm x 12mm x 5mm length, width and thickness respectively) having a stopper of depth 3mm.one part of the sample was placed on the other leaving a space between them of dimensions (12mm x 12mm x 3mm length, width and thickness respectively) to sandwich the relining material (6,7). preparation of heat cure and high impactacrylicsamples the wax pattern was coated with separating medium and allowed to dry then the lower portion of the metal flask was filled with dental stone that mixed according to the manufacturer’s instructions. the wax pattern was inserted into the dental stone slurry to one-half of pattern depth and left to set.after the stone was set, it was coated with separating medium and allowed to dry, then the upper portion of the metal flask was positioned on top of the lower portion and filled with stone, vibration was done to eliminate the air bubbles. stone was allowed to harden before wax elimination.wax elimination was performed using boiling water then the flask was opened. the flask was allowed for cooling at room temperature.then the stone moldwas coated with separating medium and allowed to dry. the polymer and monomer of heat cure acrylic was mixed according to the manufacturer’s instructions and when the mixing reached the dough stage, it was packed into the stone mold and then curedaccording to the manufacturer’s instructions. after curing deflasking was done and the samples were removed then finished and polished except the areas that would be attached to relining material which represent the tissue surface of the denture.after polishing the samples were conditioned in distilled water at 37oc for 48 hours (8). the samples were ready for relining. preparation of thermosens samples the same flasking techniques that werementioned previously were followed in preparation of the thermosens samples with some difference. a dental stone slurry was poured into the lower half of the vertex thermoflask (special flask for injection), then the wax pattern was inserted into the stone slurry to one-half of wax patterndepth and left to set.after the stone was set, it was coated with separating medium and allowed to dry, then wax sprues were used major sprues with 6-8mm in diameter, minor sprues 24mm in diameter were attached to selected areas of the wax pattern (9) (fig. 1). then the upper portion of the special flask was positioned on top of the lower portion and the screws of the flask were tightened then filled with stone, vibration was done to eliminate the air bubbles. stone was allowed to harden.wax elimination was materials manufacturer 1 thermosens denture base, relining material vertex – dental b.v. 3705 hj zeist, netherlands 2 heat cure acrylic denture base vertex – dental b.v. 3705 hj zeist, netherlands 3 high impact heat cure acrylic denture base vertex – dental b.v. 3705 hj zeist, netherlands 4 thermofusingbonding agent vertex – dental b.v. 3705 hj zeist, netherlands j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 30 performed using boiling water then the flask was opened. the flask was allowed for cooling at room temperature. after that the stone mold was coated with special separating medium which is called vertex thermo flow and allowed to dry then the two halves of flask were closed and fixed by screws of flask. fig. 1: wax sprues attached to wax patternsin vertex thermo flask procedure of injecting of the thermosens denture base material the procedure started with preheating ofthe cylinder of the thermoject machine to 290oc then the cartridge of the thermosens denture base material was inserted inside the cylinder and the flask was placed in its position in the machine, after that thermosens material started to be injected after heating time of 18minutes and a pressure of 6.5 barat 290oc according to the manufacturer’s instructions. after injecting the thermosens material the program ended with cooling for 1 minute, and then the flask was removed from the machine and allowed for cooling at room temperature. the flask was opened and the samples were removed from it then the sprues were cut and the samples were finished and polished except the areas that will receive the relining material. the samples were conditioned in distilled water at 37oc for 48 hours (8). then the samples were ready for relining. surface roughness of samples (group a1-b1c1) the samples were sand blasted by using laboratory air abrasive blaster with 100 µm aluminum oxide at air pressure of 4 bars for 1 minute.the samples were held with a specially designed fixture for standardization of the distance between the samples surface and the nozzle of the device to be 20mm (10). application of relining material to the samples the two parts of the samples were seated one on the other in such manner that leaving a space between them for the relining material, this space was filled with wax. then the sample was flasked in the vertex flask, the sample was invested with stone in the lower half of the flask then wax sprue was joined with the wax that was placed between two parts of the sample, then flasking and wax elimination was done as previously mentioned. before closing the flask the facing surfaces of sample was coated with thermofusing “bonding agent” at relining areas only according to the manufacturer’s instructions, then the injecting procedure was done, finishing, polishing and conditioning of samples were also done as mentioned in preparation of thermosens samples. after that the samples were ready for shear bond strength test. measuring procedure of shear bond strength the samples were subjected to shear load with cross head speed (1mm/min) using load cell capacity (1000n) of the instron machine (11).the force of bond failure was recorded in newton, which was divided by the area of the bonded surface to obtain the shear bond strength calculated in mpa. sbs=f/sa=mpa sbs=shear bond strength f=force sa=surface area of bonded site (mm2) results and discussion mean values, standard deviation (sd), minimum values and maximum values of the shear bond strength results are presented in table (2). table 2: descriptive statistics of the shear bond strength of different groups in mpa groups mean s.d. min. max. a1 1.94 0.10 1.79 2.13 a2 5.05 0.19 4.77 5.38 b1 2.11 0.13 1.93 2.29 b2 5.34 0.21 5.06 5.62 c1 10.81 0.82 9.88 11.88 c2 19.98 0.58 19.17 20.97 in general the shear bond strength of thermosens denture base material samples (group c) showedthe highest mean values and the lowest bond strength was in heat cure acrylic samples (group a) and the high impact acrylic samples were in between (group b).the results also showed that theshear bond strengthdecreased in samples with surface roughness when compared with samples without surface roughness of the samedenture base material (between groups 1 and 2 of each group of denture base materials). j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 31 the study revealed that the three types of denture base materials showed different shear bond strength, this bonding can be attributed to reaction of the ester end of the thermo fusing liquid (which contains butyl alcohol, acetone, isopropyl alcohol and silicic acid tetraethyl ester homopolymer h4slo4) with methyl methacrylate of the (heat cure acrylic or high impact acrylic) or with amide of the thermosens. the results showed that there was no significant difference in shear bond strength between samples of heat cure acrylic and high impact acrylic tables (3 and 4), this may be due to similarity of the monomer of both material which was methyl methacrylate, while the shear bond strength was increased significantly in samples of thermosens tables (3 and 4), this increasing in the bond might be attributed to the high rate of crosslink between similar resin materials (denture base and relining materials and bonding agent) (12,13). the results showed that the surface roughness reduced the shear bond strength significantly, table (5), and this might be attributed to: table 3: comparison between the groups using anova test surface treatment anova f-test p-value sig. with surface treatment a1 & b1 & c1 1103.542 0.000 hs without surface treatment a2 & b2 & c2 5207.785 0.000 hs d.f. = 29 table 4: lsd test after anova surface treatment groups mean difference p-value sig. with surface treatment a1 b1 -0.17 0.438 ns c1 -8.867 0.000 hs b1 c1 -8.697 0.000 hs without surface treatment a2 b2 -0.29 0.095 ns c2 -14.938 0.000 hs b2 c2 -14.648 0.000 hs table 5: effect of surface treatment on the shear bond strength comparison t-test p-value sig. a1 vs. a2 -44.952 0.000 hs b1vs. b2 -41.903 0.000 hs c1vs. c2 -28.830 0.000 hs the liquidized thermosens has high viscosity which provided a low flowability that prevented the total engagement of thermosens with the micro pitting. the micro pitting produced an elevation and depression at the surface of denture base material so the peaks of elevation act as a stress points to weaken the bond at the interface. the rough surface decreased the surface tension which consequently affects interface adhesion. references 1. bowman jf, javiad ns. relining and rebasing techniques. dental clinic of north america 1977; 21: 369-78. 2. anusavice kj. philip’s science of dental materials.11th ed. saunders/elsevier; 2008. 3. craig rg, powers jm. restorative dental materials.11th ed. st. louis: mosby co.; 2002. 4. al-athel ms, jagger rg. effect of test method on the bond strength of a silicone resilient denture lining material. j prosthet dent 1996; 76: 535-40. 5. takahashi y, chai j. shear bond strength of denture reline polymers to denture base polymers. int j prosthodont 2001; 14(3): 271-5. 6. al-azawi rw. evaluating of some mechanical properties of soft liner. a master thesis, department of prosthetic dentistry, college of dentistry, university of baghdad, 2008. 7. reem as. effect of certain chemical surface treatment on repaired bond strength of different heat cure denture base materials. a master thesis, department of prosthetic dentistry, college of dentistry, university of baghdad, 2013. 8. american dental association specification no.12.guide to dental materials and devices. 10th ed. chicago; 1999. p.32. 9. rizgar ma. the effect of addition of radiopaque materials on some mechanical and physical properties of flexible denture base. ph.d. thesis, department of prosthetic dentistry, hawler medical university; 2009. 10. firas aa. effect of different metal surface treatments on microleakage of two types of the acrylic resin: heat cure and light cure at co/cr interface. a master thesis, department of prosthetic dentistry, college of dentistry, university of baghdad, 2009. 11. memarian m, shayestehmajd m. the effect of chemical and mechanical treatment of the denture base resin surface on the shear bond strength of denture repairs, rev clinpesq odontol 2009; 5(1): 11-7. 12. stipho hd, talic yf. repair of denture base resin with visible light-polymerized reline material: effect on tensile and shear bond strengths. j prosthet dent 2001; 86: 143-8. 13. takahashi y. and chai j. assessment of shear bond strength of three denture reline materials and denture base acrylic resin. int j prosthodont 2001; 14(6): 5315. rafah f.doc j bagh college dentistry vol. 27(3), september 2015 the effect of adding restorative dentistry 28 the effect of adding single walled carbon nanotube with different concentrations on mechanical properties of heat cure acrylic denture base material rafah adil ibrahim, b.d.s., m.sc. (1) abstract background: the most widely used material for fabrication of denture base is poly methyl methacrylate, despite its popularity, the main problems associated with it as a denture base material are poor strength particularly under fatigue failure inside the patient mouth, impact failure outside the patient mouth, which are the main causes for fracture of denture, several studies was done to increase mechanical properties of denture base. the present study was conducted to evaluate and compare the effect of addition single walled carbon nanotubes in different concentrations to polymethyl methacrylate on some mechanical properties (surface hardness, surface roughness, impact strength and transverse strength). materials and methods: forty eight samples were prepared for pilot study divided into four groups according to the concentrations of singled walled carbon nanotubes ( 0%, 0.5%, 1% & 1.5%) added to heat cure acrylic resin , each group was divided into four subgroups according to the tests conducted (surface hardness , surface roughness, impact strength and transverse strength) and the results obtained were evaluated to determine the concentration of singled walled carbon nanotubes (swcnts) that improve the mechanical properties of heat cure acrylic resin to be used to complete our study, so another 80 samples were made divided into two main groups (0% swcnts as control group) and (1.5% swcnts test group) and all the tests were done again. results: impact strength and transverse strength were significantly increased after adding 1.5% swcnts while surface hardness was significantly decreased and surface roughness was non-significantly affected when compared with control group. conclusions: impact strength and transverse strength of hot cure acrylic resin reinforced with 1.5% swcnts were greatly increased. keywords: carbon nanotubes, transverse strength, impact strength. (j bagh coll dentistry 2015; 27(3):28-32). introduction the most widely used materials in dentistry due to its satisfactory mechanical and physical properties, aesthetics, biocompatibility with oral tissues, low coast, ease in production and reparability is polymethylmethacrylate (pmma), however these material are subjected to intraoral or extra oral stresses which may cause fracture in acrylic denture bases which is a time consuming and costly problem besides the fact that they are very inconvenient for the patient (1-3). the most common reasons of fracture of the denture is its low resistance to impact which may lead to fracture in any accidental dropping while cleaning or due to fatigue which will lead to cracking caused by high masticatory force (4,5) in order to overcome this problem, several attempts were made to modify and improve the strength and hardness of pmma. these attempts included the additions of filler particles such as zirconia, glass fiber, alumina (6,7). recent experimental studies have suggested that carbon nanotube which are10-100times higher than the strongest steal at a fraction of the weight when incorporated in pmma, which result in enhanced properties of the matrix remarkably. swcnts are extremely strong resilient and very (1)assist. lecturer. department of prosthodontics, college of dentistry, university of baghdad. light in weight, however their disadvantage are high cost and dark in color but it could be used in area that are frequently fractured like the midline of the upper denture when there is large labial notch (8,9) . there are two types of carbon nanotube singled wall that posses the fundamental cylindrical structure and multiwalled tubes that are made from two or more coaxial cylinders, both types of nanotubes can improve properties of polymer system (10). materials and methods sample preparation a mould of stone in dental flask was prepared by using a metal pattern with dimensions of (80mm, 10 mm and 4mm) length, width and thickness for impact test and (65mm, 10mm and 2.5 mm) for transverse strength, hardness and roughness according to ada specifications no. 12 (1999) then the mould was coated with separating medium and dry for 15 minutes. for preparing control group samples, according to the manufacturer’s instructions, a powder / liquid ratio for acrylic was 22 g/10 ml weighted by electronic balance with accuracy of (0.0001g) (sartorius bp 30155, germany), then the acrylic was mixed and packed in the dough stage in the mould and cured by heating the flask in water bath at 74cº for 1.5 hours after that j bagh college dentistry vol. 27(3), september 2015 the effect of adding restorative dentistry 29 increase the temperature to boiling for 30 minutes and then cool the flask for another 30 minutes at room temperature, finally for 15 minutes under tap water according to ada specifications no.12 (1999). test group samples were prepared by the addition of the single walled carbonanotubes from sigma aldrich 50-70% carbon basis, d ×l 1.21.5nm×2-5 nm, bundle dimensions were added to the monomer. the fillers were well dispersed in the monomer by ultra-sonication using sonication apparatus (soniprep -150, england) at 120 w, 60 khz for 3 minutes to break them into individual nanotubes. the monomer with the nanopowder was immediately mixed with acrylic powder to reduce the possibility of particle aggregation phase separation. the mixing was carried out by a clean wax knife in a clean and dry vessel and mixed for 30 seconds. the mixture was then covered and left to stand until a dough stage was reached, then the packing and flasking is the same as control group. a pilot study was done to estimate the proper amount of swcnts that will improve the mechanical properties of pmma by testing the surface hardness, roughness, impact strength and transverse strength. first, 48 samples were prepared and divided into four groups according to the concentrations of swcnts that was added to it: 0.0 % (served as control group), 0.5%, 0.1% and 1.5% . according to the result obtained from the pilot study as shown in table (1), the addition of 1.5% swcnts to pmma resulted in significant increase in impact strength and transverse strength with significant decrease in surface hardness, therefore; the decision was made to take this percentage (1.5%) to complete this research. new samples were prepared they were divided into 2 groups first group with no additives (control group), the other with 1.5 % carbon nanotubes, ten samples for each test were made as previously mentioned. surface hardness test: shore d hardness device was used for measuring the acrylic samples, three measurements were recorded on three areas (one on the middle of the specimen and the other two, 1cm away from each end of each specimen) and an average of these three reading was recorded. surface roughness test: a profilmeter device was used to study the surface roughness property of acrylic samples, three points were selected to be tested (one on the middle of the specimen and the others 1cm away from each end) and the mean of the three readings were recorded for each specimen. impact strength test: the samples were tested with charpy type impact testing device (impact tester, n.43-1, inc. usa) of 2 joules capacity, impact strength was calculated by this formula: impact strength = 3 in kj/m2 e=impact energy, b= width of sample, d = thickness of sample (11). transverse strength test: the samples were tested by flexural measuring device (jian, qiao, japan). the full scale load was (7.5 kn), the distance between 2 parallel supports was (50 mm) and transverse strength was calculated by this formula: transverse strength = in n/mm2 i= distance between 2 support, b= width of the samples, d= thickness of the samples (11). results in table (1) the pilot study revealed that hardness was significantly decreased with the increase in the percentage of swcnts added and its lowest value was (69.3) with 1.5% of swcnts while there were no significant difference in surface roughness with different concentrations of swcnts and the results of both impact strength and transverse strength were significantly increase to be (12.87 kj/m2 ,127.7 n/mm2 ) when the concentrations of swcnts were increase and show its greatest value with 1.5 % of swcnts. table (2) showed the mean, standard divisions, standard of error, minimum and maximum values of hardness, roughness, impact strength and transverse strength for the control group, while in table (3) it showed the results for 1.5% concentration of cnts added to the acrylic resin. the mean value of hardness was decreased (69.55) after adding the 1.5% of swcnts when compared with control group (80.78) while the mean value of roughness was nearly the same after adding 1.5% swcnts (1.43 mm) . meanwhile the mean value of impact strength and transverse strength was greatly increased to be (12.83 kj/m2) and (127.36n/mm2) after adding 1.5% swcnts as shown in tables (2) and (3). in table (4) and figure (1) t test between 1.5% swcnts and control group show that there is highly significant difference in hardness, impact strength and transverse strength while for roughness there were non-significant difference between them. j bagh college dentistry vol. 27(3), september 2015 the effect of adding restorative dentistry 30 table 1: the mean values of pilot study test groups hardness roughness μm impact strength kj/m2 transverse strength n/mm2 control 80.96 1.447 5.92 84.56 0.5% 77.43 1.427 7.04 96.03 1 % 71.83 1.447 8.92 107.9 1.5 % 69.3 1.455 12.87 127.7 table 2: descriptive statistics of control group transverse strength n/mm2 impact strength kj/m2 roughness μm hardness 84.84 5.978 1.4528 80.78 mean 1.641 0.446 0.057 1.132 sd 0.522 0.142 0.018 0.360 se 81.1 5.33 1.38 79.31 min 86.4 6.9 1.541 82.3 max table 3: descriptive statistics of 1.5 % of swcnts transverse strength n/mm2 impact strength kj/m2 roughness μm hardness 127.36 12.833 1.4349 69.55 mean 6.979 0.786 0.087 1.413 sd 2.222 0.251 0.027 0.450 se 120.2 11.97 1.311 67.3 min 145.1 14.5 1.535 72.1 max table 4: t-test between control and 1.5 % sw cnts transverse strength n/mm2 impact strength kj/m2 roughness μm hardness 18.533 23.491 0.528 20.075 t-test p<0.01 p<0.01 0.61 p<0.01 p-value hs hs ns hs sig. *p>0.05 (non-significant), p<0.01 (highly significant) figure 1: bar chart of the mean values for hardness, roughness, impact strength and transverse strength for both control group and 1.5 % swcnts discussion a lot of studies with different nanofillers were done to evaluate the effect of adding the fillers on the mechanical properties of pmma, in this study, the effect of adding swcnts was investigated. in the present study, this material because there is limited studies in compare with its j bagh college dentistry vol. 27(3), september 2015 the effect of adding restorative dentistry 31 advantages as one of the strongest material in nature, elastic and also light in weight (12) . the results of pilot study was used in order to select the proper concentration of swcnts to be added to pmma which it was (1.5% concentration),as it give use the lowest value of surface hardness with the greatest value of impact and transverse strength in comparing with other percentage of swcnts. surface hardness hardness is the resistance of a material to the plastic deformation typically measured under an indentation load. hardness is an important property of denture base material as it determines its flexibility, and it is desirable to have material with softness that is similar to the oral mucosa softness (13). in this study, the results indicated that there was a highly significant difference in hardness after adding 1.5 % of swcnts to pmma in comparing with control group, this decrease in hardness could be explained based on elastic property of cnts that the nanotubes are remarkably flexible, that they found that in addition to its strength, cnts are soft and elastic because cnts by geometry have different properties in axial and radial direction. it has been shown that the cnts are very strong in axial direction on the other hand there were evidence that in the radial direction they are rather soft (14,15). this agreed with mahmood (16) who investigated the effect of adding swcnts on high impact denture base material and found significant decrease in hardness, also agreed with al-qenae (17) who reported that addition of nano alumina ceramic fiber to silicone decrease the hardness value. however, the results did not agree with dahham (18) who added zinc oxide nanofiller to the acrylic denture base and reported significant increase in hardness; this could be due to the use of different nanofiller was added and different technique. roughness achieving a smooth surface with no scratches has always been important to the materials used in denture base; this is because it is related to the adherence of plaque, debris and stain that will affect the oral health of the soft tissue in direct contact with denture (19). in the present study, there were no significant difference in roughness between 1.5% cnts and control group this is may be due to that the swcnts have very small size and well dispersion, and profilometer device which was used is concerned the outer surface only and did not measure inner part of nanocomposite so when we add a small amount of cnts only few particles will be on the surface of the specimens (20). the result of this study was coincide with the result of jasim (21) who added alumina nanofiller to the acrylic and found that there were no significant difference in roughness, also coincide with nabil (22) who added zro2 nanoparticles to pmma and he found that there was no significant difference in roughness. impact strength impact strength is an important property for acrylic denture base which are commonly fractured when it accidentally dropped into hard object it is simply the amount of energy absorbed by the material when it is suddenly broken (4). in this study, significant increase in impact strength was shown with test group (1.5% swcnts ) in compare with control group this may be due to the interfacial shear strength between nanofiller and matrix was high due to formation of cross links or supra molecular bonding which cover or shield the nanofiller that in turn prevent propagation of crack (8,23). this results agreed with al kheraif (24) who investigated the effect of adding carbon nanotubes to increase impact strength of light cure denture base and also agree with al husayni (25) who found increase in impact strength compared to control after adding silver nitrate to the denture base, but disagreed with abdul razzaq 26) who found impact strength decrease with the use of glass flakes to reinforce denture base materials. transverse strength transverse strength defined as material ability to resist deformation under mastication load (4). in this study, transverse strength was significantly increase with 1.5 % swcnts in compare to control group; this is due to use of very fine size nanofillers enable them to enter and fill the space between the chains of polymer , so it restrict the motion of chains and lead to increase rigidity and this will increase the transverse strength (27). mahmood (16) also found significant increase in transverse strength after adding swcnts to high impact denture base material, and also agreed with jasim (22) who investigate the effect of adding 1% and 2% alumina nanofiller to pmma and found increase in the transverse strength. j bagh college dentistry vol. 27(3), september 2015 the effect of adding restorative dentistry 32 references 1. meng tr, walls awg. physical properties of four acrylic denture base resin. j contemporary dent practice 2005; 6: 110-23. 2. kammann zga, wachter w. comparison of fracture test of denture base materials. j prosthetic dentistry 2003; 90(6): 578-84. 3. franklin pd, bubb nl. reinforcement of polymethylmethacrylate denture base with glass flake. dental materials 2005; 21: 365-70. 4. darbar ur, huggett r, harriosn a. denture fracture survey. br dent j 1994; 176: 342-5. 5. abboud m, vol s, duguet e. pmma–based composite materials with reactive ceramic fibers, part ш: radiopacifying particle reinforced bond cement. j master sci 2000; 11: 295-300. 6. alhareb ao, ahmad za. effect of al2o3/zro2 reinforcement on the mechanical properties of pmma denture base. j reinf plast compos 2011; 30: 83-5. 7. chaijareenont p, takahashi h. effect of different amount of 3 methaacrylixypropyltrimethoxysilane on the flexural properties and wear resistance of alumina reinforced pmma. dental materials j 2012; 31(4): 623-8. 8. andrew mb, pienkowski d. multi wall carbon nanotubes enhance fatigue performance of physiological maintained methyl methacrylatestyrene. copolymer carbon 2007; 45: 2098-104. 9. wang r, billtu jt. characterization of multiwall carbon nanotubes polymethyl methacrylate composite resin as denture base material. jpd 2014; 3(4): 31826. 10. archana b, abhishek b. nanotechnology in dentistry: present and future. jioh 2014; 6(1): 121-6. 11. anusavice kj. philips science of dental materials .11th ed. louis: saunders elsevier; 2007: p. 143-66, 721-56. 12. chang t, gao h. size dependent elastic properties of a single walled carbon nanotube via a molecular mechanics model. j mechanical and physics solids 2003; 51(6): 1059-74. 13. anusavice kj. philips science of dental materials 11th ed. st. louis: mo. saunders; 2003. p.737. 14. rodriguez m, lopez g, serrano af, et al.. improvement of vickers hardness measurement on swnts /al2o3 composites consolidated by spark plasma sintering. j euro ceramic soci 2014; 34: 38019. 15. scotti k. mechanical properties evaluated of dental base pmma enhanced with singled walled carbon nanotubes. a master thesis, school of dentistry, indiana university, 2010. 16. mahmood ws. the effect of incorporating carbon nanotubes on impact, transverse strength, hardness and roughness to high impact denture base material. j bagh coll dentistry 2015; 27(7): 96-9. 17. al-qenae n. nano ceramic fiber reinforced silicone maxillofacial prosa master thesis. a master thesis, school of dentistry, indiana university, 2010. 18. dahham tb. the effects of modified zinc oxide nanofillers addition on some properties of heat cure acrylic resin denture base material. a master thesis, college of dentistry, university of baghdad, 2014. 19. machado al, breeding lc. hardness and surface roughness of reline and denture base acrylic resin after repeated disinfection procedures. j prosthetic dentistry 2009; 102(2):115-22. 20. al –momen mm. effect of reinforcement on strength radio opacity of acrylic denture base materials. a master thesis, college of dentistry, university of baghdad, 2009. 21. jasim bs. the effect of silanized alumina nano fillers addition on some physical and mechanical properties of heat cured polymethyl methacrylate denture base material. a master thesis, college of dentistry, university of baghdad, 2013. 22. nabile e. evaluation the effect of modified nanofillers addition on some properties of heat cure acrylic resin denture base materials. a master thesis, college of dentistry, university of baghdad, 2011. 23. goguta l, marsavina l. impact strength of acrylic heat curing denture base resin reinforced with e – glass fiber. timisora medical j 2006; 56: 88-92. 24. al-kheraif asb. an investigation into the impact and flexural strength of light cure denture resin reinforced with carbon nanotubes. world applied sci j 2012; 18(6): 808-12. 25. alhusayni ok. effect of silver nitrate incorporation into heat polymerized acrylic resin on bacterial activity and some mechanical properties. a master thesis, college of dentistry, university of baghdad, 2013. 26. abdulrazzaq ht. the effect of glass flakes reinforcement on some mechanical properties of heat cured poly methyl methacrylate denture base material. a master thesis, college of dentistry, university of baghdad, 2013. 27. katsikis n, franz z, anne h. thermal stability of pmma/silica nano and micro composites as investigated by dynamic – mechanical experiments. polymer degra and stability 2007; 22: 1966-76. marwan.doc j bagh college dentistry vol. 27(2), june 2015 management of oral and maxillofacial surgery and periodontics 123 management of facial fistulas and sinuses marwan g. saied, b.d.s., f.i.c.m.s. (1) ahmed a. al-kinani, m.b.ch.b., f.i.c.m.s. (2) abstract background: a major difference between the treatment of the skin lesions and the odontogenic and nonodontogenic sinuses. we aimed to analyze a substantial number of consecutive causes in order to clinical suspicion in the differential diagnoses may be correctly weighted. materials and methods: the material of this research consisted of 40 patients. a complete history is collected from the patients with the duration and the site of the sinus present, the patient was examined for factors of the fistulas and sinuses and its associations, and patient having any concomitant lesions, a medical consultation done for opinion and management. clinical examination with facial fistulas and sinuses was mandatory to avoid any mistakes that may occur. a treatment plan was contemplated regarding a conservative line will be followed or a surgical intervention was indicated results. results: the common etiological causes: congenital and acquired causes. fifteen patients have eighteen facial sinuses and fistulas (40.9%) developed because of non-odontogenic infections, fifteen patients had fifteen facial sinuses (34%) because of odontogenic infections, four congenital sinuses (9%) developed at three patients, two patients with two facial sinuses (4.5%) due to tumor growth, three patients with three facial fistulas (6.8%) due to traumatic causes and one patient with one facial sinus (2.2%) because of actinomycosis and unknown cause for each. conclusions: the maxillofacial surgeon should be aware of causes of whether developmental anomalies, deep seated infections, epithelization of the tract, insufficient or inadequate drainage, deep lining foreign bodies and certain types of infections. key words: facial fistulas and sinuses, management, odontogenic and non-odontogenic causes. (j bagh coll dentistry 2015; 27(2):123-129). introduction facial fistulas and sinuses comprise an important group of lesions which may present to specialists in numerous branches of medicine. the true fistula, an abnormal communication between the lumen of one viscous and the lumen of another body surface, is rare. the more common clinical presentation is the sinus, a blind tract lined with granulations leading from an epithelial surface into the surrounding tissues. the special consideration for facial fistulas and sinuses are because of their resemblance of its appearances to basal cell carcinoma, sebaceous cyst, and other skin lesions as a furuncle can be misdiagnosed as a sinus tract to the skin of the face (1) (table1). infective facial fistulas and sinuses dental cause the opening of the sinus may be found at far distance from the dental focus of infection, a sinus from a tooth infection opened on the chest and another on the upper third of the thigh (3). dental infections simulating skin lesions (4) . cutaneous sinuses tract of dental origin in children (5), a dental etiology as part of differential diagnosis should be kept in mind with oro-facial skin lesion (6). (1) maxillofacial surgeon, department of maxillofacial surgery, al-wasity hospital, ministry of health (2) plastic surgeon, department of plastic surgery, al-wasity hospital, ministry of health table1: etiology of facial fistulas and sinuses (2) actinomycosis actinomycosis is a chronic spreading suppurative and granulomatous lesion caused primarily by actinomyces israelii. draining sinuses are formed through which the characteristic “sulphur granules” are discharged. a persistent periapical disease with recurrent sinus tracts, histological diagnosis confirmed actinomycosis, the lesion was treated with antibiotics and periapical surgery (7). osteomyelitis a case of sinus discharge at infra orbital region after repair of orbital floor defect by a silastic sheet and another case of two sinuses 1 embryological preauricular sinus. labial region. 2 infective dental causes. specific infections e.g. t.b., actinomycosis. osteomyelitis. dental implant. bronj 3 trauma transected salivary ducts. infected fractures. bullet injury. 4 carcinoma result of carcinomatous growth. effect of radiation. 5 miscellaneous malnutrition (cancrum oris). j bagh college dentistry vol. 27(2), june 2015 management of oral and maxillofacial surgery and periodontics 124 discharging at submental region due to infected mandibular fracture (8) . an additional cause for oral cutaneous fistulas is bisphosphonate-related osteonecrosis of jaws (bronj) (9) , so any oral/ dental causes increasing bronj include abscesses, periodontal disease. the risk of development of bronj with oral bisphosphonate is very small but increase when therapy exceeds 3 years (10) . dental implant dental implants can develop infections, leading to intraoral and possibly extraoral sinus tract drainage (11) . carcinomatous cause of facial fistulae an orocutaneous fistula can occur after any operation on the oral cavity to remove a tumour and the most important causative factors are previous radiotherapy and inadequate control of nutritional status, diabetes and anaemia in the preoperative period, poor operative technique. often the fistula will be the result of surgical intervention for the neoplastic disease (12) . a case of an orocutaneous fistula reported with pathological fracture of the mandible in patient with osteoradionecrosis which followed orthovoltage radiation (13). also a case reported of an oropharyngocutaneous fistula in an irradiated patient (14). materials and methods the material of this study consisted of 40 patients with (44) facial fistulas and sinuses (26 males and 14 females and the average was 20years) suffering of a fistula or sinus in the facial region, between september 2009 and november 2013, at the al-wasity hospital for reconstructive surgery at al-resafa institute of ministry of health, baghdadiraq. they were either referred from other hospitals or outpatient clinic of the same hospital. the common an etiological cause were divided into two groups: congenital and acquired causes and the acquired causes divided into odontogenic infection, non-odontogenic infection, traumatic, tumor growth, actinomycosis and unknown causes (table 2). our definition of the face as the front part of the head which includes lips, cheeks, nose, eyes, forehead and one finger below lower border of the mandible. we excluded the fistulas and sinuses which occur in the neck or inside the mouth. on admission a complete history was collected from the patients concerning name, age, gender, residency, the duration and the site of the sinus present. clinical examinations of the patients is mandatory which include inspection, palpation and probing the sinus as well as radiographic examination which include conventional radiographical views like periapical, occlusal, panoramic views of the mandible and lower portions of maxilla and supplementary methods like sinography with stainless steel wire 0.5 mm in diameter or sinogram with injection of radiopaque dye (ipomer) through sinus tract. we examined cutaneous tissue of the face to look for any skin lesion or dental lesion or malignant tumor. also parotid region and submandibular with submental regions have examined to look for any salivary gland fistulas or dental lesion. teeth are checked and recorded (deciduous and permanent), recorded whether sound healthy or carious teeth, also looking for any swelling intraorally. also intraoral palpation of a cord-like structure connecting the skin lesion with the underlying alveolar ridge is helpful in establishing the diagnosis and according to the diagnosis, a treatment plan was contemplated, regarding a conservative line will be followed or a surgical intervention was indicated. results fourteen patients have seventeen facial sinuses at submandibular region, four patients with four facial sinuses at submental region, eleven patients with eleven facial sinuses at cheek region, three patients with three facial sinuses at preauricular region and canthal regions for each, one patient with two labial sinuses, one patient with facial sinus at temporal region, parotid region, chin region, zygomatic region for each, (table 3). four patients having facial fistula (either orocutaneous or salivary fistula), thirty-four patients having facial sinus, two patients having facial fistula and sinus, and two patients have bilateral facial sinuses (table 4). table 2: causes of facial fistulas and sinuses causes % non-odontogenic infection 40.9% odontogenic infection 34% congenital 9% traumatic 6.8% tumor 4.5% actinomycosis 2.2% un known 2.2% j bagh college dentistry vol. 27(2), june 2015 management of oral and maxillofacial surgery and periodontics 125 table 3: sites of facial fistulas and sinuses table 4: number and percentage of patients with fistulas and sinuses the facial sinuses were more in males prevalent than in females (65% versus 35%) (figure 1), and the (16-30) year's cohort made up the largest group (32.5%) (figure 2). surgical interruption was adopted in 31 patients with 35 facial sinuses or fistulas (figure 3). six of the patients with facial sinus associated with a mandibular fracture infection. sites patients number of fistulas and sinuses percentage submandibular region 14 17 38.6% cheek region 11 11 25% submental region 4 4 9% preauricular region 3 3 6.8% canthal regions 3 3 6.8% temporal region 1 1 2.2% labial region 1 2 4.4% zygomatic region 1 1 2.2% chin region 1 1 2.2% parotid region 1 1 2.2% type number of patients percentage facial fistula only 4 10% facial sinus only 34 85% facial fistula and sinus 2 5% facial sinus "bilaterally" 2 5% 0 5 10 15 20 25 30 35 0-15 16-30 31-45 46-60 60 onward figure 2: age distribution figure 3: mode of treatment males 60% females 40% figure 1: sex distribution 0 10 20 30 40 50 60 70 80 s urg ic al tre atme n t co nse rva tio n trea tme nt re fus e trea tme nt j bagh college dentistry vol. 27(2), june 2015 management of oral and maxillofacial surgery and periodontics 126 discussion a chronic facial lesion is occasionally the skin manifestation of a fistula of dental abscess origin. it will persist until the abscess nidus is obliterated. the distance of the lesion from the oral cavity and the patient freedom from tooth discomfort do not exclude the dental cause. this study showed that (32.5%) of the affected patients were in the age group (16-30) years old while (22.5%) were in the age group( 31-45) years of age, (20%) were in the age group of (0-15) years of age, (15%) were in the age group (46-60) years of age and (10%) were in the age group 60 onward. seventy-five percent of patients were under 45 years, this goes with malik and bailey series (2), perhaps because of shorter life expectancy. the predominant males to females ratio was supported by mortenson et al. (15) and malik and bailey series (2) were more than 60% of patients were males and about 40% were females. in this study non-odontogenic infections was the most common cause and this include for example patients with facial sinuses due to infected bone graft. also in this series tmj arthritis cause a facial sinus in one of our patients who was uncontrolled diabetic patient and other patient presented with orocutaneous fistula at submandibular region after excision of sequamous cell carcinoma of the tongue with pectoralis major flap for reconstructive due to infection with staphylococcus aureus and pseudomonas microorganisms .while in previous studies the distributions of cases based towards odontogenic origin and this is perhaps because many of patients may go to other departments or remain totally symptomless or the sinuses usually develop in connection with the developmental anomalies or because of presence of a deep seated infection or the presence of certain types of infection of the tract wall. odontogenic infections is a second of frequency in this study while in malik and bailey series (2) in two years period treated 100 consecutive cases of facial sinuses with a mean of 50 patients per year was the commonest cause of facial sinuses . one patient was diagnosed by general surgeon as a skin lesion so he treated three times by local excision of the sinus for one year duration while the diagnosis was infected keratocyst in the ramus of the mandible, other patient presented with a submandibular sinus for six months duration as skin lesion and the diagnosis was infected carious lower mandibular first molar tooth. a dental examination and radiographs recommended to rule out infection of dental origin (16) . one patient presented with a facial sinus discharging pus at lateral canthal region of left eye due to osteomyelitis of the left maxilla. we reported four sinuses discharging in four patients due to infected maxillary teeth while chernosky (1940) said maxillary sinuses discharging are rare and the gravity is accepted as the reason for the facility with which lower jaw abscess proceed to fistulization . so we think a cutaneous facial sinus tract of dental origin are often initially misdiagnosed and inappropriately treated. correct diagnosis and treatment will result in predictable and rapid healing of these lesions. the third cause of facial sinuses was congenital cause, which result in four facial sinuses in three patients (9%) and these includes preauricular sinuses in two patients. the fourth cause of facial sinuses and fistulas was a traumatic cause. the fifth cause of facial sinuses was a tumor growth which result in two facial sinuses in two patients (4.5%) while this finding recorded in malik and bailey series a third cause. the sixth cause of facial sinuses was actinomycosis infection which results in one facial sinus (2.2%) and this goes with malik and bailey series who they considered this finding one of uncommon causes (figure 4). figure 4: patient with multiple sinuses due to actinomycosis infection. j bagh college dentistry vol. 27(2), june 2015 management of oral and maxillofacial surgery and periodontics 127 the basic technique for management of facial fistula or sinus depends on the correct diagnosis which includes the awareness of the possibility of an odontogenic sinus by knowing that striking granulomatous lesion which may occurs about the gum, the face, and the neck and which may presents one end of a persistent sinus tract. the other end of this sinus usually originates in the apical abscess of a tooth but may take its origin in any osteomyelitis process of the jaw or foreign body infections. out of the forty four facial fistulas and sinuses, four sinuses and three facial fistulas were treated conservatively, the treatment involve the detection of the cause which lead to the sinus or fistula formation either infected tooth with periapical pathosis or salivary gland injury have been treated conservatively through dressing extraorally with iodoform packing intraorally. surgical treatment was considered in thirty two facial sinuses and three facial fistulas. fourteen sinuses due to odontogenic infection treated by extraction of the tooth and endodontic therapy of the tooth with curettage of the sinus tract with antibiotic or removal odontogenic cyst, four sinuses due to foreign body infection treated by removal of the bony sequestrum or the stainless steel wire (figure 5). a b c figure 5: a: patient with sinus discharge due to infected stainless steel wire for fixation of bone graft of right mandibular body reconstruction; b: radiograph shows infected stainless wire fixation; c: patient after the removal of the infected stainless steel wire and healed sinus discharge two sinuses due to infected mandibular fracture in some patients because of the presence of a tooth in the mandibular fracture lead to infected fracture and sinus formation treated by extraction of the tooth with curation of the socket of tooth, three sinuses and one orocutaneous fistula due to bone graft infection (autogenous outer table of iliac crest bone), four sinuses and one cutaneous fistula due to osteomyelitis of the jaws, one sinus due to arthritis of tmj who was a known case of iddm result in a temporal abscess with a cutaneous sinus discharge we treated him by controlling the blood sugar level with drainage of temporal abscess, one patient with orocutaneous fistula postoperatively to excision of carcinoma of tongue treated by a free flap (radial chinese flap) (figure 6) , two patients with four congenital sinuses an elliptical incisions were j bagh college dentistry vol. 27(2), june 2015 management of oral and maxillofacial surgery and periodontics 128 made and sinus tract were dissected out together with direct closures while for the facial sinuses for actinomycosis infection treated by debridement with a heavy antibiotics. the use of a negative pressure vacuum associated closure technique for orocutaneous fistulas was reported (17). a b c figure 6: patient with orocutaneous fistula, a: closure of orocutaneous fistula by forarm radial free flap (chinese flap), b: intraorally, c: extraorally. all patients except the patient treated for excision of a malignant tumor were operated upon under local anesthesia or conservatively. two patients refuse the treatment and one only one facial sinus unhealed. the majority of the patients kept on regular follow up for 2-3 weeks (table 5). j bagh college dentistry vol. 27(2), june 2015 management of oral and maxillofacial surgery and periodontics 129 table 5: treatment of 44 cases of facial sinuses references 1. cantatore jl, klein pa, lieblich lm. cutaneous dental sinus tract, a common misdiagnosis: a case report and review of the literature. cutis nov 2002; 70(5): 264-7 2. malik sa, bailey bmw. cervicofacial sinuses. british j oral maxillofac surg 1984; 22: 178-88. 3. endelman j. cutaneous sinus tract of odontogenic origin. a misdiagnosed lesion. indian j dental sci 2014; 1: 6. 4. abuabara a, schramm ca, zielak jc, baratto-fillo f. dental infection simulating skin lesion. an bars dermatol 2012; 87(4): 619-21. 5. bonder l, manor e, joshua bz, barabas j, szabo g. cutanous sinus tract of dental origin in children. pediatr dermatol 2012; 29(4): 421-5. 6. diagnosis and treatment of odontogenic cutaneous sinuses of endodontic origin and diagnosis of cutaneous facial fistulae of dental origin. oral surg oral med oral pathol 2011. 7. jeansonne bg. periapical actinomycosis: a review. quintessence int 2005; 36(2):149-53. 8. rowe nl, williams j. maxillofacial injuries. 1985 9. cassio p, et al. bisphosphonaterelated osteonecrosis of jaws in patient with multiple myloma. med oral pathol oral cir bucal 2008; 13(1): e52-7. 10. eklund mk. bisphosphonate-related osteonecrosis of the jaws (bronj). southwest oral surgery and implant blog; 2010. 11. tözüm tf, sençimen m, ortakoglu k, ozdemir a, aydin oc, keles m. diagnosis and treatment of a large periapical implant lesion associated with adjacent natural tooth: a case report. oral surg oral med oral pathol oral radiol endod 2006; 101(6): e132-8. 12. wood nk, goaz pw. differential diagnosis of oral lesions. 3ed ed. 1985. p. 193-203. 13. topazian rg, goldbery mh. oral and maxillofacial infections. 3rd ed. w.b. saunders co.; 1994. 14. olasz l, kawashie f, nemth a. closure of oropharyngocutaneous fistulae in an irradiated patient. int j oral maxillofac surg 1999; 28: 364-5. 15. mortencen h, winther je, birn h. periapical granulomas and cysts. an investigation of 1600 cases. scand j dent res 1970; 78: 241. 16. sheehan dj, potter bj, davis ls. cutaneous draining sinus tract of odontogenic origin: unusual presentation of a challenging diagnosis. south med j 2005; 98(2): 250-2. 17. andrews bt, smith rb. orocutaneous and pharyngocutaneous fistulae. ann oto/ rhino/ laryngol 2008: 117(4): 298-302. :الخالصة نحن تھدف إلى تحلیل عدد كبیر من األسباب متتالیة من أجل االشتباه السریري في . شأ وغیر سنیة المنشأھناك فرق كبیر بین معالجة اآلفات الجلدیة والنواسیر سنیة المن: المقدمة .التشخیص التفریقي یمكن المرجحة بشكل صحیح لنواسیر الحاضر، تم فحص المریض لعوامل من یتم تحصیل التاریخ الكامل من المرضى الذین یعانون من مدة وموقع ا. مریضا 40المواد من ھذا البحث وتألفت من : المواد و الطرائق كان الفحص السریري للناسور والتجاویف الوجھیة إلزامیة لتجنب أي أخطاء قد . الناسور والمتعلقات لھا، وجود أي اآلفات المصاحبة، واالستشارة الطبیة القیام بھ إلبداء الرأي واإلدارة .العالج تحفظیًا أو التداخل جراحیًا تم التفكیر في وضع خطة العالج فیما سیكون. تحدث بسبب العدوى غیر ,) ٪40.9(حیث خمسة عشر مریضًا یحتوون على ثمانیة عشر من النواسیر و التجاویف الوجھیة . األسباب الخلقیة والمكتسبة: إن االسباب العامة تتضمن: النتائج وضعت في ثالثة مرضى، ) ٪9(بسبب التھابات سنیة المنشأ، وأربع نواسیر الوجھیة الخلقیة ) ٪34(سنیة المنشأ، وكان خمسة عشر مریضا یحتوون على خمسة عشر النواسیر الوجھیة نتیجة ألسباب الصدمة ومریض ) ٪6.8(ورم، ثالثة مرضى مع ثالثة التجاویف الوجھیة وذلك بسبب نمو ال) ٪4.5(واثنین من المرضى الذین یعانون من اثنین من النواسیر الوجھیة .بسبب داء الشعیات والسبب غیر معروف لكل واحد) ٪2.2(واحد مع ناسور وجھي واحد میقة الجذور، أو االندمال بتشكل النسیج الظھاري من الجھاز، أو یجب أن یكون جراح الوجھ والفكین على علم باالسباب سواء ان تكون تشوھات تنمویة، أوااللتھابات الع: االستنتاجات .الصرف غیر كافیة، و االجسام األجنبیة العمیقة وأنواع معینة من االلتھابات treatment no. of cases % endodontic treatment of lower anterior teeth. 1 2.25% treatment of osteomyelitis of jaws. 5 11.4% treatment of salivary gland injury fistulas. 3 7% extraction and antibiotic treatment of maxillary teeth. 8 18.3% extraction, antibiotic and excision of sinus tract treatment of mandibular teeth. 4 9.1% surgical extraction and curettage of infected non-erupted mandibular tooth. 1 2.25% tumor treatment of mandibular ameloblastoma. 2 4.5% enculation of mandibular keratocyst cyst and antibiotic 1 2.25% removal of foreign body from the mandible, check and tmj. 4 9.1% treatment of mandibular fractures infection. 2 4.5% treatment of mandibular bone graft infection. 4 9.1% treatment of tmj arthritis in the temporal region. 1 2.25% treatment of orocutaneous fistula in submandibular region. 1 2.25% treatment of congenital sinuses in the lower lip and preauricular regions. 4 9.1% treatment of actinomycosis of submandibular region. 1 2.25% refuse treatment. 2 4.5% total 44 100% farqad final.doc j bagh college dentistry vol. 26(2), june 2014 evaluation of oral oral diagnosis 69 evaluation of oral health status in patients receiving antiepileptic medications farqad najm abed, b.d.s. (1) raja h. al –jubouri, b.d.s., m.sc., ph.d. (2) abstract background: epilepsy is a common neurological disorder of incidence rate 1-2%. genetic, congenital, developmental, tumors, head trauma and central nervous system infections maybe the cause of epilepsy. this study aimed to determine the prevalence of stomatitis, xerostomia and taste disorder among patients taking carbamazepine or sodium valproate and to make salivary analysis for iga, cystatin c and salivary flow rate. material and method:this study performed in alyarmuk teaching hospital in baghdad, samples consist of (70) epileptics half of them treated with carbamazepine and other half treated with sodium valproate, and (18) healthy control group of both genders and with different ages to detect the prevalence of oral manifestations, salivary iga and cystatin c changes. results: salivary iga is significantly higher in epileptics than healthy group. dmft is significantly lower in epileptics than in healthy control. gi is hardly affected by epilepsy. salivary flow rate was significantly lower in epileptics than the healthy control group. on the other hand, cystatin c was obviously higher in epileptics but failed to reach the level of statistical significance. mucositis in epileptics was significantly higher. candidal infection and dysguisia failed to reach the level of statistical difference. conclusion: the most affected oral measurement by epilepsy was salivary iga then salivary flow rate followed by dmft. cystatin c had a marginal contribution to the context of case –control discrimination.sodium valproate is safer than carbamazepine when compared by its effects on the oral health. mucositis, candida infection and dysguisia were lower in epileptics who were treated with sodium valproate. salivary flow rate was higher in sodium valproate treated group than in carbamazepine group. gi and dmft were lower in sodium valproate treated group than the carbamazepine group. keyword: salivary iga, cystatin c, antiepileptic medications (aems). (j bagh coll dentistry 2014; 26(2): 69-73). :الخالصة . عصبي المركزي ھي من اھم اسباب الصرعاألورام الوراثیة والخلقیة والتنمویة، الصدمات النفسیة والتھابات الجھاز ال%. 2-1الصرع اضطراب عصبي شائع معدل االصابة یونو غلوبیولین أ، سیستاتین ج لتحدید مدى انتشار اضطراب التھاب الفم، وجفاف الفم، والذوق بین المرضى الذین یتناولون كاربامازبین أو الصودیوم فالبرویت وتحلیل ام: ھدف دراسة . ومعدل تدفق اللعاب مریض مصاب بالصرع یتم عالج نصفھم مع كاربامازبین، والنصف اآلخر مع ) 70(ھذه الدراسة أجریت في مستشفى الیرموك في بغداد، تتكون العینات من : المواد والطریقة نغلوبیف عن انتشار التغییرات الشفویة، امیونو من كال الجنسین ومع اإلعمار المختلفة للكش) 18(فالبرویت الصودیوم، وفریق مراقبة صحیة . مقیاس التھاب اللثة ال یكاد یتأثر بالصرع. أقل بكثیر في الصرع مما في مجموعة المراقبة مقیاس التسوس. امیونو غلوبیولین أ أعلى بكثیر في الصرع من مجموعة المراقبة: النتائج . في حین ان السیستاتین ج كان أعلى في الصرع ولكنھ فشل في الوصول إلى مستوى الداللة اإلحصائیة. جموعة المراقبة الصحیةوكان معدل تدفق اللعاب أقل بكثیر في الصرع من م . اإلصابة بالفطریات وتغییرات التذوق فشلتا في التوصل إلى مستوى الفرق اإلحصائي. التھاب الغشاء المخاطي في الصرع كان أعلى بكثیر وكان سیستاتین ج ذو مساھمة ھامشیة في سیاق التمییزبین . مقیاس التسوسالشفوي األكثر تأثرا بالصرع كان االمیونوغلوبیولین أ ثم معدل تدفق اللعاب تلیھا المقساس :االستنتاج الفطریات واضطرابات التذوق وب الغشاء المخاطي التھا. فالبرویت الصودیوم أكثر أمانًا من كاربامازبین إذا ما قورنت بإثارة على صحة الفم واألسنان. المصابین واالصحاء مجموعة كانتأقلفیمقیاس التسوسومقیاس التھاب اللثھ . فالبرویتالصودیومممافیمجموعةكاربامازبینمجموعة وكانمعدلتدفقاللعابأعلىفی. فالبرویتالصودیومیتم عالجھمبكانتأقلفیالصرعالذین .مازبینكارباالمجموعةمما ھي علیھ في فالبرویتالصودیوم .االدویة المضادة للصرع, سیستاتین ج,امیونوغلوبیولین أ: مفاتیح البحث introduction epilepsy is defined as a neurological condition characterized by recurrent epileptic seizures unprovoked by any immediately identifiable cause. an epileptic seizure is the clinical manifestation of an abnormal and excessive discharge of a set of neurons in the brain (1). epilepsy should be viewed as a symptom of an underlying neurological disorder and not as a single disease entity. the clinical presentation of epilepsy depends on a number of factors, chiefly: the parts of the brain affected the pattern of spread of epileptic discharges through the brain, the cause of the epilepsy and the age of the individual (2). (1) m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. the classification of the epilepsies is controversial and has tended to focus on both the clinical presentation (type of epileptic seizure) and on the underlying neurological disorder (3). epilepsy is primarily a clinical diagnosis based on a detailed description of the events before, during and after a seizure given by the person and/or witness. electroencephalogram (eeg), magnetic resonance imaging (mri) and computed tomography (ct) are used to investigate individuals with known and suspected epilepsy (4). the uk national general practice study of epilepsy found that 60% of people with epilepsy have convulsive seizures, of which two thirds have focal epilepsies and secondarily generalized seizures and the other third have generalized tonic-clonic seizures. they also found that the majority (60%) of people with newly diagnosed or suspected epileptic seizures had epilepsy with no j bagh college dentistry vol. 26(2), june 2014 evaluation of oral oral diagnosis 70 identifiable etiology. vascular disease was the etiology in 15% and tumor in 6%. among older subjects the proportion with an identifiable cause was much higher: 49% were due to vascular disease and 11% to tumors (5). the mainstay of treatment for epilepsy is antiepileptic medications (aems) taken daily to prevent the recurrence of epileptic seizures. since the development of mri there has been an increase in the number of people identified with epilepsy who could benefit from surgery. there is also a need to ensure provision of appropriate information to people with epilepsy and their carries (6). it is a general impression that patients with epilepsy tend to have poorer oral health and receive less adequate dental treatment in comparison with the general (nonepilepsy) population (7). a survey of oral health and dental status of patients with epilepsy in comparison with the non-epilepsy population had been taken. only one such survey has been published (8), which was, however, uncontrolled. others concentrated on only the periodontal status in relation to antiepileptic medication (aems) (9).the aim was to test statistically whether these patients did indeed have poorer oral health compared with that of the nonepilepsy population, and if so, to cast light on the possible reasons and measures to be taken to avoid it. oral health is an important aspect of quality of life, and every effort should therefore be made to improve oral health, especially in a group of people already disadvantageously affected by their disease. since no extensive study was conducted in iraq on the effect of epilepsy and aems on the oral health (carbamazepine and sodium valproate), therefore this study was to detect the relationship between epilepsy and oral health status in relation to salivary iga, cystatin c and salivary flow rate were determined. materials and methods the study sample consisted of (70) patients complaining from epilepsy, 50 % of them (35) patients were taking carbamazepine; the other 50% (35) patients were taking sodium valproate (patients were on medication for minimal 6 months) and the control group is (18) apparently healthy individual of both genders; they were examined from the period (jan-2013 to may 2013) in al-yarmouk teaching hospital in baghdad, to detect the oral manifestations related to these antiepileptic medications and iga and cystatin c were measured in the saliva of both groups. approval was obtained from ministry of health for patient’s examination and collection of saliva and laboratory work. exclusion criteria: patients with other chronic diseases such as: metabolic, liver disease, severe inflammation, malignancy or children under the age of 6 or individuals above 60 years. instruments used for oral examination of patients diagnostic instruments disposable gloves. periodontal probes. antiseptic solution (hipitane 5%). dental chair oral examination all the patients examined by a single examiner, under standardized conditions; the oral cavity examined by diagnostic instrument. the procedure of examination of oral soft tissue was done in sequence according to directions suggested by the who(1987), the examination begun with the lip, upper and lower sulcus, retro-molar area, upper and lower labial mucosa, buccal mucosa, then the hard and soft palate, dorsal, margins and inferior surface of tongue, floor of the mouth were also examined. in case of oral mucosal lesion, the duration, size, clinical description, location of lesion, and finally the clinical diagnosis were stated. oral manifestations dry mouth (salivary flow rate) dry mouth is a common symptom most often caused by a decrease in the amount of saliva or a change in the quality of saliva. (10). in this study dry mouth and salivary flow rate were diagnosed according to the anamenesis below: does your mouth feel dry? do you experience any difficulties in chewing dry foods? do you experience any difficulties in swallowing dry foods? are you aware of any recent increase in the frequency of liquid intake? (11) salivary flow rate measurement the average salivary flow rate was obtained from the total volume collected in the study time (12) and salivary flow rate was calculated as ml/min. mucositis oral mucositis is inflammation of the mucosa of the mouth which ranges from redness to severe ulceration. symptoms of mucositis vary from pain j bagh college dentistry vol. 26(2), june 2014 evaluation of oral oral diagnosis 71 and discomfort to an inability to tolerate food or fluids candidal infection it was determined clinically. dysguisia taste alteration can be diagnosed in this study according to the criteria taken from the european organization for research and treatment of cancer (eortc): have you had problems with your sense of taste? and did food and drink taste different from usual? the abnormal taste may appear bizarre or limited to a part of the mouth. (13). caries presentation dmft index (14) : decayed-missing-filled index (dmf) which was introduced by klein, palmer and knutson in 1938 and modified by who: dmf teeth index (dmft) which measures the prevalence of dental caries/teeth. gingival overgrowth and bleeding(gingival index) (15). indices used for gingival disease assessment: *gingival index (gi).... which was introduced by loe and silness in 1963 immunological analysis saliva collection: the method of wu-wang was used for saliva collection (16). to avoid circadian variation, saliva samples were collected between 9 a.m. and 1 p.m. in order to obtain a sample of total saliva, the patients were instructed not to eat or drink (except water) for 1 hour (17). mouth washing with pure water was carried out right before sampling. all participants were instructed to collect saliva in their mouths for 5 minutes and to spit into a clean plastic container (plain tube). saliva samples were kept in ice during the collection. in order to reduce bubble and foam, samples were centrifuged, pipetted into two androff tubes one for iga and the other for cystatin c analysis and stored at 70 oc freezer until immunological analysis (18). finally levels of salivary iga and cystatin c were determined by elisa. immunological analysis (salivary iga) determination of salivary iga is done by enzyme link immunosorbent assay elisa (19). immunological analysis (cystatin c) this assay employs the quantitative sandwich enzyme immunoassay technique. antibody specific for cys-c has been pre-coated onto a micro plate. standards and samples are pipetted into the wells and any cys-c present is bound by the immobilized antibody. after removing any unbound substances, a biotin-conjugated antibody specific for cys-c is added to the wells. after washing, avidin conjugated horseradish peroxidase (hrp) is added to the wells. following a wash to remove any unbound avidinenzyme reagent, a substrate solution is added to the wells and color develops in proportion to the amount of cys-c bound in the initial step. the color development is stopped and the intensity of the color is measured. results the mean age range of sodium valproate group was significantly lower than carbamazepine group. as shown in table 1. table 1: the difference between carbamazepine and sodium valproate treatment for epilepsy on mean of age range carbamazepine sodium valproate p age (years) <0.001 range (6 60) (6 60) mean 31.5 20.4 sd 13.9 11 se 2.36 1.87 n 35 35 table 2: the difference between carbamazepine and sodium valproate treatment for epilepsy on mean of salivary iga, dmft and gi. carbamazepine sodium valproate p salivary iga 0.74[ns] range (59 369) (80 379) mean 237.8 244.5 sd 91.7 75.9 se 15.5 12.83 n 35 35 dmft 0.02 range (1 20) (0 20) mean 7.9 5.5 sd 3.9 4.4 se 0.65 0.74 n 35 35 gingival index 0.008 range (0.12 1.43) (0.04 1.25) mean 0.63 0.43 sd 0.31 0.29 se 0.052 0.049 n 35 35 j bagh college dentistry vol. 26(2), june 2014 evaluation of oral oral diagnosis 72 both dmft and gi were significantly lower in sodium valproate group than carbamazepine group. while iga was higher in valproate group but failed to reach the statistical significance (table 2). salivary flow rate was higher in sodium valproate group and cystatin c was lower in the same group than in carbamazepine group, even though both differences were not significant. (table 3). table 3: the difference between carbamazepine and sodium valproate treatment for epilepsy on median of salivary flow rate and cystatin c. carbamazepine sodium valproate p salivary flow rate 0.2 [ns] range (0.01 1.2) (0.02 1.3) median 0.2 0.33 interquartile range (0.05 0.56) (0.1 0.52) n 35 35 mean rank 32.4 38.6 salivary cystatin c 0.51 [ns] range (20.5 450) (17 320) median 80 72 interquartile range (60 135) (45 150) n 35 35 mean rank 37.1 33.9 in figure (1) it is shown that mucositis was significantly higher in carbamazepine group than valproate group. both candida infection and dysguisia were higher in carbamazepine group but fail to reach statistical significance. discussion salivary iga is the prominent immunoglobulin and is considered to be the main specific defense mechanism in oral cavity (8). the variations in the immunoglobulin level in different studies are related to the source, method of collection, measurement as well as number of other variable, the salivary secretion rates may inversely influence the iga concentration in saliva (20). iga was higher in valproate -group, this may be due to the effect of the drug on the immune system. dmft and gi were lower in valproate group as they have higher iga the present study shows that the mucositis is significantly lower in patient on sodium valproate treatment as compared to the carbamazepine group this may be due to higher salivary flow rate and higher iga. figure 1: bar chart showing carbamazepine sodium valproate difference in positivity rate of selected clinical features. tegretol and depakene are the trade names for carbamazepine and sodium valproate respectively. references 1. robert fisher s, leppik ilo. when does a seizure imply epilepsy? j epilepsia 2008; 49: 7–12. 2. duncan js, shorvon sd, fish dr. clinical epilepsy. new york: churchill livingstone; 1995. 3. jerome engel jr. ilae classification of epilepsy syndromes. epilepsy res j 2006; 70: 5–10. 4. engel jr. a proposed diagnostic scheme for people with epileptic seizures and with epilepsy: report of the ilae task force on classification and terminology. epilepsia 2001; 42(6): 796-803. 5. david mccandles w. epilepsy: epidemiology of epilepsy. epilepsia 2012; 98: 29-40. 6. macdonald bk, johnson al, goodridge dm. factors predicting prognosis of epilepsy after presentation with seizures. ann neurol 2000; 48(6): 833-41. 7. shaw mj, shaw l, foster td. the oral health in different groups of adults with mental handicaps attending birmingham (uk) adult training centers. community dent health 1990; 7: 135–41. 8. ogunbodede eo, adamolekun b, akintomide ao. oral health and dental treatment needs in nigerian patients with epilepsy. epilepsia 1998; 39: 590–4. 9. galas-zgorzalewicz b, borysewicz-lewicka m, zgorzalewicz m. the effect of chronic carbamazepine, valproic acid and phenytoin medication on the periodontal condition of epileptic children and adolescents. funct neurol 1996; 11:187-93. 10. sankar v, rhodus, n. the american academy of oral medicine. dry mouth (xerostomia) 2007; 425: 778-6162. 11. azambuja s, henrique p, jacobs r, nackaerts o, fischer ir, henrique f, jorge s, aparecido s, maitê j bagh college dentistry vol. 26(2), june 2014 evaluation of oral oral diagnosis 73 barroso da, lúcia a. clinical diagnosis of hyposalivation in hospitalized patients. j appl oral sci 2012; 20:157-61. 12. thaweboon s, thaweboon b, nakornchai s, jitmaitree s. salivary secretory iga, ph, flow rates mutans streptococci and candida in children with rampant caries. southeast asian j trop med public health 2008; 39:893-9. 13. cawson ra, odell ew. essentials of oral pathology and oral medicine. 8th ed. 2008. p.441. 14. burt ba, eklund sa. dentistry, dental practice and the community. 6th ed. philadelphia: wb saunders; 2005. 15. worthington hv, jan clarkson ew, bryan g, paul bv. routine scale and polish for periodontal health in adults. j clin periodontol 2013; 40:1016-24. 16. wu-wang cy, patel m, feng j, milles m, wang sl. decreased levels of salivary prostaglandin e2 and epidermal growth factor in recurrent aphthous stomatitis. arch oral biol 1995; 40:1093-8. 17. martinez, ko, mendes ll and alves jb. secretory a immunoglobulin, total proteins and salivary flow in recurrent aphthous ulceration. rev bras otorrinolaringol 2007; 73: 323-8. 18. externest db, meckelein ma, schmidt fa. correlations between antibody immune responses at different mucosal effectors sites are controlled by antigen type and dosage. elsevier sci 2000; 68: 38309. 19. valdimarsdottir hb, arthur a. stone-psychosocial factors and secretory iga. critical reviews in oral biology & medicine 1997; 8:461-474. 20. eliasson l, birkhed d, osterberg t, carlén a. minor salivary gland secretion rates and immunoglobulin a in adults and the elderly. eur j oral sci 2006 114(6): 494-9. type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 49 research article crystallization firing effect on the marginal discrepancy of the ips. emax cad crowns using two different cad/cam systems fatima kadhim ghadeer 1* , lateef essa alwan 2, abdul kareem j. al-azzawi 3 1 middle technical university (mtu), collage of health and medical techniques, department of prosthodontics techniques, baghdad , iraq. 2 middle technical university (mtu), institute of medical technology, baghdad , iraq. 3 al-turath university, collage of dentistry , baghdad , iraq. *correspondence: email, fatima.kadhim@mtu.edu.iq abstract: background: marginal adaptation is critical for long – term success of crown and bridge restoration. computer aided design / computer aided manufacture (cad/ cam) system is gaining more importance in the fabrication of dental restoration. objective: the aim of this study is to evaluate the effect of crystallization firing on the vertical marginal gap of ips. emax cad crowns which fabricated with two different cad/cam systems .materials and methods: twenty ips e.max cad crowns were fabricated. we had two major groups (a, b) (10 crowns for each group) according to the cad/cam system being used: group a: fabricated with imes icore cad/cam system; group b: fabricated with in lab sirona cad/cam system. each group was subdivided into two subgroups pre-crystallized (group a1, b1) and crystallized crowns (group a2, b2). at four points on each aspect of the crown, marginal gaps were assessed on the master metal die by using digital microscope at a magnification of (110x) and imagej program. the measurement was done twice for each crown; before and after crystallization process.results: the lowest mean of marginal gap before and after crystallization was (29.387±2.774μm) and (70.108±5.569μm) respectively for group a (imes icore system) and the highest mean value before and after crystallization was (51.728 ±3.774μm) and (84.071 ±4.567μm) respectively for group b (sirona system). paired sample t-test result showed a statistically highly significant difference in marginal gap between all groups.conclusions: the crystallization process increases the vertical marginal gap. imes icore system showed the lower marginal gap than sirona system. the two systems have an acceptable marginal gap .keywords: ips. emax cad, cad/cam system, marginal discrepancy, crystallization firing introduction the marginal gap is defined as the vertical distance between the preparation's finishing line and the cervical edge of the restoration (1). poor adaptation and an excessively large gap , which may result in cement dissolution, allowing saliva , food debris , and oral bacteria to seep along the gap between the restoration and the preparations walls , raising the risk of dental caries and periodontal disease (2). both clinicians and patients have shown interest in metal-free biocompatible restorations, prompting researchers to look for alternatives. all ceramic restorations with excellent biocompatibility, colour consistency, high wear resistance, and superior light transmissivity have been created to meet this need (3). there are numerous ceramic systems available, which may vary in composition or manufacturing technique. lithium disilicate and zirconia-based systems are two of the most widely used products in clinical practice. prefabricated blocks milled with a cad/cam device can be used to make the restoration (4). received date: 11-04-2022 accepted date: 21-05-2022 published date: 15-03-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licens es/by/4.0/). https://doi.org/10.26477/jbcd .v35i1.3316 mailto:fatima.kadhim@mtu.edu.iq https://orcid.org/0000-0002-1398-5713 https://orcid.org/0000-0001-5870-2628 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3316 https://doi.org/10.26477/jbcd.v35i1.3316 j. bagh. coll. dent. vol. 35, no. 1 2023 ghadeer et al 50 lithium disilicate blocks are easier to mill because they are initially partially sintered and relatively soft. this material requires crystallization after milling procedure , which is normally accompanied with a 0.2% shrinkage accounted for by the designing program (5). in 2005 ivoclar vivadent introduced ips e.max cad as an enhanced ceramic material optimized for cad/cam processing. it is made of lithium disilicatereinforced glass ceramic, but its physical characteristics and translucency are improved (6). in the field of fixed partial denture ,the progress of cad/cam provided to the dentist newer and faster treatment options . the cad-cam system used to scan , design and mill the restoration . two types of cad/cam systems were presented in the market ,the clinic ( in-office ) and ( in –lab ) systems (7). many factors can affect the precision and fit of dental ceramic restoration such as firing cycle, fabrication technique, scanning unit, milling device, size and type of milling instruments, and type milling procedure (8). the purpose of this study was to assessed the effect of crystallization firing on the marginal discrepancy of ipse.max cad crowns fabricated by two different cad/ cam systems. the null hypothesis was that crystallization firing and different cad/cam systems have no effect on the marginal discrepancy of ipse.max cad crowns. materials and methods die fabrication a prepared plastic mandibular right first molar (nissin dental products ,kyoto japan ) with rounded shoulder finishing line of uniform thickness of 1mm, axial and occlusal reduction of about1.5mm was used for the construction of a master metal die several cad/cam studies have used master metal dies (9-12). the master metal die resist the wear during fabrication procedures and measurements (10).the metal die was fabricated by using cad / cam system to simulate the shape of ideal prepared plastic tooth to receive the all ceramic crowns(12). the plastic prepared die was scanned with white light scanner (dof ,full hd , 2 m pixel /,korea),then the digital model of the die transferred to the cam software to start the milling process of the metal die by using the milling unit (vhf s1 ,k5 impression machine , germany) which was loaded with cobalt chromium disc (10 mm)(interdent,travagliato (bs) italy). the base of metal dies was made by placing the metal die in the plastic ring and pouring the dental stone type iv ( syna rock , italy) to 3 mm below the finishing line . metal die with stone base (figure1). figure 1: the final metal die with stone base j. bagh. coll. dent. vol. 35, no. 1 2023 ghadeer et al 51 twenty crowns were introduced in this study which is divided into two groups based on the cad/cam system used for crown fabrication ,group a: 10 crowns were fabricated with (imes icore cad/cam system),group b: 10 crowns were fabricated with (in lab sirona cad/cam system).each group then subdivided into two subgroups (precrystallized ipse.max cad crowns) and (crystallized ipse.max cad crowns). crowns fabrication glass ceramic block of lithium disilicate (ipse.max cad lt b2/c14,ivoclar vivadent, schaan, liechtenstein) was used to produce all ceramic crown. twenty ipse.max cad crowns were fabricated by using two different cad/cam systems, imesicore dental system (250i 5 axis ,gmbh, leibolzgraben, germany) , and inlab sirona dental system (4 axis ,gmbh, bensheim, germany).all construction steps including metal die scanning, designing of software and milling were accomplished according to the instruction of manufacturer for each ipse.max cad block and cad/cam systems. the crowns characteristics were equal and fixed to have cement space of 50µm and adhesive space of 100µm from the finishing line .crystallization firing was carried out at 850°c for 25 minutes in a porcelain furnace ( ep3010,ivoclar vivadent , schaan ,liechtenstein ) according to the manufacturer's instructions. exclusive trays and pins were utilized in conjunction with ips object fix putty ( ivoclar vivadent , schaan ,liechtenstein) (7) . each of the tested crowns was seated on the metal die and inspected for vertical marginal gap, using digital microscope ( dinolite , taiwan ) at magnification of 110x. four midline were drawn in the center of crown and metal die, and four point were marked on each surface of the metal die and crown (two points at the border of the center line while the other points were at a distance of 1mm from the points mentioned on both left and right sides (8). a custom designed specimen holding device , consisting of a screw holding portion with a load sensor, was utilized to keep the crowns in correct position on the metal die during measurement and to apply pressure (5 kg) , the margins' digital images were captured and evaluated using image processing program ( image j ). the marginal gap of the 20 crowns was measured before and after crystallization firing, 320 measurements for each system ,thus yielding 640 measurements in all. results the vertical marginal gap of crowns were measured twice; before and after crystallization .a1, b1, (before crystallization).a2, b2, (after crystallization).the lowest vertical marginal gap mean(29.387± 2.774μm) was scored by imes-icore system crown before crystallization (group a1) , while sirona system crown after crystallization(group b2) presented the highest mean value (84.071± 4.567 μm) (table.1) . the mean and standard deviation values of the marginal gap before and after the crystallization process showed that the marginal gap was larger after the crystallization firing and this difference was highly statistically significant (table.2). https://www.hindawi.com/journals/bmri/2016/8635483/tab1/ j. bagh. coll. dent. vol. 35, no. 1 2023 ghadeer et al 52 the analysis was performed using the paired sample t-test between each of the two subgroups of the two systems and the difference in vertical marginal gap between the two different cad/cam systems was highly statistically significant (p<0.01) ( table .3). table 1: descriptive statistics of the marginal gap (µm) in each group systems groups n mean s.d. min. max. imes-icore system a1 10 29.387 2.774 25.063 33.811 a2 10 70.108 5.569 62.637 77.263 sirona system b1 10 51.728 3.774 45.472 57.273 b2 10 84.071 4.567 77.211 89.580 table 2: descriptive statistics and effect of crystallization on the marginal gap groups before crystallization after crystallization effect of crystallization (d.f..=9) mean s.d. mean s.d. mean difference t-test p-value a1 vs. a2 29.387 2.774 70.108 5.569 -40.721 -23.087 0.000 (hs) b1 vs. b2 51.728 3.774 84.071 4.567 -32.343 -18.401 0.000 (hs) table 3: the paired sample ttest for effect of different cad/ cam on the marginal gap groups mean s.d. mean difference t-test p-value a1 29.387 2.774 -22.341 -23.087 0.000 (hs) b1 51.728 3.774 a2 70.108 5.569 -13.963 -18.401 0.000 (hs) b2 84.071 4.567 discussion marginal gap (mg) is defined as the measurement between finishing line of the preparation and margin of the crown (9). the minimization of marginal gap of crown is an important feature in prosthodontics dentistry that can contribute to clinically long term success of the restoration (10) . the cad / cam systems are used in the manipulation of ceramics, such as zirconia or glass ceramics , as well as, this technology have the ability to produce an accurate fit and individual design, simple handling characteristics, and time consuming production processes; in addition to that, the components of cad/cam system are extremely homogenous and biocompatible(11) . j. bagh. coll. dent. vol. 35, no. 1 2023 ghadeer et al 53 lithium disilicate ceramics are used for restoring anterior and posterior single crowns and because they have the advantage of minimum linear shrinkage , they have been employed for a variety of applications including single crowns for implants , inlays, onlays, and laminate veneer prosthesis (12). in this study, an ideal prepared plastic tooth#46 with rounded shoulder finishing line was selected which enable more accurate seating of the crown (13). several studies have shown that clinically acceptable margins can be achieved using either a chamfer or a shoulder finishing line (14) . the metal die was fabricated by using cad/cam to simulate the shape of an ideal prepared plastic tooth to receive the all ceramic crowns (15). in this study, a specimen holding device was specially designed to hold the ipse.maxcad crowns on the metal die on the microscope stage during measurement .furthermore, this device designed to have a load sensor connected to digital numerical device ,in order to ensure that a uniform standard load of (5 kg) was applied on each crown during measurement (16-18) . each crown had sixteen marginal gap assessment sites , the measurement of vertical marginal are made at four point on each crown sides (10, 19). in the current study digital microscope was used for marginal measurement , this measurement method did not include any procedures such as sectioning or replication of the cement space before measurement the marginal gap ,making it less expensive non-destructive , less time consuming than other techniques and reducing the risk of error accumulation that can occur when multiple procedures are used (19-21) . after a clinical assessment of more than 1000 crowns over a 5 years period, several authors estimated maximum marginal opening values and concluded that a marginal gap of no more than 120µm is clinically acceptable (22) .the acceptable marginal gap discrepancies for cad/cam crowns are reported between 50 to 100µm (14, 23-25) . the result of this study showed that it was a high significant increasing effect on the marginal gap of both groups ( a,b) after crystallization, this finding comes in agreement with kim,oh et al and azarbal a. et al (26, 27). this effect could be attributed to the fact that the material prior to crystallization is lithium metasilicate (partially crystallized) with particle's size range between 0.2 m and 1 m . after crystallization the size of particle become 5m. the crystallization process accompanies the prismmatic glass ceramics formation and dispersed over the glassy matrix (28) . furthermore, as the crystal spacing become more intense and the proportion of lithium disilicate microcrystals within the glassy matrix increases from 40% to 70% after complete crystallization, a 0.2% linear contraction occurs during crystallization process; this modification can increase marginal gaps (12) . the differences between the systems was highly significant this agree with att, komine et al and abduo , lyons et al (35, 36) whom concluded that the use of different systems for fabricating zirconia frameworks has an effect on the final marginal and internal fit. the fabrication method (technique of scanning, process of milling , milling burs size and condition of material during milling procedure) can have an effect on the adaptability of ceramic restorations (29) . j. bagh. coll. dent. vol. 35, no. 1 2023 ghadeer et al 54 imes icore cad/cam system ( group a ) provide less marginal gap as compared with in lab sirona cad/cam , this could be because that the imes icore cad/cam system has five axis milling machine while the in lab sirona cad/cam has a four axis milling machine(12) . the addition of axes to the machine has improved the accuracy and precision of ceramic restorations , these two additional guide axes permit for machining and milling of difficult parts that cannot be milled with three or four axis milling device. the cutting conditions of 5-axis milling device are superior to those of three or four axis milling device, which provide restoration with excellent texture , dimensional accuracy and surface finish .this could illuminate the more appropriate marginal fit of the restoration made with a five axis milling device. (30). this coincides with hamza and sherif (15) whom assessed the marginal gap of monolithic zirconia restoration fabricated on stainless steel die which scanned by one scanner and the crowns milled by different milling machine :mcxl milling machine (4axis) , ceramil motion 2 milling machine(5axis), wieland dental milling unit(5axis),zirkonzahn milling unit m1( 5axis), and vhfs1dental milling machine (5axis) ,the result showed that all tested cad /cam systems produce monolithic zirconia restoration with clinically acceptable marginal gap and cam machines with 5axes produce lower marginal gap. this is in contrast to the study done by beuer , korczynski et al (31) whom investigated the marginal and internal fit of zirconia based fixed dental prostheses fabricated by a cercon eye laser scanner then the prostheses fabricated with the laboratory (3-axis) cad/cam system (cercon brain) and the centralized cad/cam system compartis integrated systems (5axis) they reported that there is no significant difference for both system with mean values (56.0± 34.5μm) and (51.7± 45.2μm), respectively, both means value are below than the clinically acceptable value (120μm). and disagree with al-assadi and alazzawi (18) whom assessed the effect of veneering of porcelian on the marginal gap of zirconia coping compared to full contour zirconia crown fabricated with amman girbach cad/cam system (5axis dry milling) ,sirona cad/cam system (4axis wet milling) ,and zikonzahn cad/cam system ( 5axis dry milling) . they measured the marginal gap by stereo microscope. they reported that all mean values are below than the clinically acceptable value ,and the sirona system produce the lower mean value. the milling burs of these cad/cam systems vary in shape and these differences may affect the final result of ceramic prosthesis (32, 33). conclusion in the light of the result obtained, the study concluded the following: 1 .both cad/cam systems fabricated lithium disilicate crowns with clinically acceptable marginal gap mean value before and after crystallization. 2. marginal gap increased after crystallization due to ceramic contraction at the margin , which occur during densification of lithium disilicate crowns. 3. 5axes system showed statistically lower marginal gaps than the 4axes cad/cam system. conflict of interest: none. j. bagh. coll. dent. vol. 35, no. 1 2023 ghadeer et al 55 references 1. euán, r., figueras‐álvarez, o., cabratosa‐termes, j., et al comparison of the marginal adaptation of zirconium dioxide crowns in preparations with two different finish lines. j prosthodont impl esth recon dent. 2012; 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20(16): 623-30. 27. azarbal, a., azarbal, m., engelmeier, r.l., et al. marginal fit comparison of cad/cam crowns milled from two different materials. j prosthodont 2018; 27: 421-8. 28. giordano, r. materials for chairside cad/cam–produced restorations. jada 2006; 137: 14s-21s 29. comlekoglu, m., dundar, m., özcan, m., et al. influence of cervical finish line type on the marginal adaptation of zirconia ceramic crowns. oper dent. 2009; 34(5): 586-92. 30. delong, r., heinzen, m., hodges, j., et al. accuracy of a system for creating 3d computer models of dental arches. dent res j. 2003; 82(6): 438-42 . 31. beuer, f., korczynski, n., rezac, a., et al. marginal and internal fit of zirconia based fixed dental prostheses fabricated with different concepts. clin cosm investig dent. 2010; 2:(5): 485-93 . 32. bosch, g., ender, a., mehl, a. a 3-dimensional accuracy analysis of chairside cad/cam milling processes. j prosthet dent. 2014; 112(6):1425-31 . j. bagh. coll. dent. vol. 35, no. 1 2023 ghadeer et al 57 33. neves, f.d., prado, c.j., prudente, m.s., et al. micro-computed tomography evaluation of marginal fit of lithium disilicate crowns fabricated by using chairside cad/cam systems or the heat-pressing technique. j prosthet dent. 2014; 112(5): 1134-40. الحافات لتيجان االيماكس كاد باستخدام نوعين مختلفين من انظمة الكاد كام رقعلى فالعنوان: تاثير عملية التبلور لطيف عيسى علوان, عبد الكريم جاسم العزاوي , فاطمة كاظم غديرالباحثون: المستخلص: ( cad / camالتصنيع بمساعدة الكمبيوتر ) التكيف الهامشي أمًرا بالغ األهمية لتحقيق النجاح على المدى الطويل لترميم التاج والجسور. يكتسب نظام التصميم بمساعدة الكمبيوتر /يعد الخلفية: التبلور على فجوة الحافات العمودية للتيجان الخزف الزجاجي المصنعة بواسطة نظامين كاد /كام مختلفين. الهدف : الهدف من هذه الدراسة هو تقييم تأثير عملية أهمية أكبر في تصنيع ترميم األسنان. موعة أ: مصنعة تيجان لكل مجموعة( وفقًا لنظام الكاد كام المستخدم: المج 10: تم تصنيع عشرين تاًجا من نوع الخزف الزجاجي . كان لدينا مجموعتان رئيسيتان )أ ، ب( )المواد وطرق العمل: ( و تيجان 1, ب 1. وتنقسم كل مجموعة الى مجموعتين فرعيتين : تيجان الخزف الزجاجي قبل البلورة ) أ in lab sirona؛ المجموعة ب: مصنعة بنظام كاد كام imes icoreبنظام كاد كام 110x)لمعدني .تم اجراء القياس بواسطة المجهر الرقمي بتكبير )اؤشرة على كل وجه من اوجه النموذج (. لقد تم قياس فجوات الحافات ألربع عالمات م2, ب2الخزف الزجاجي المبلورة ) أ .( تم قياس العينات مرتين قبل وبعد عملية التبلورimage jوبرنامج معالج الصور ) كان النتائج: قبل وبعد التبلور فجوة الحافات معدل ك (5.569μm±70.108)و (2.774μm±29.387)اقل قبل وبعد التبلور فجوة الحافات معدل واعلى ان ـــــــــــعلى التوالي للمجموعة أ (51.728 ±3.774μm) و(4.567± 84.071 μm) على التوالي للمجموعة ب. اختبارpaired sample t-test اظهر اختالفا احصائيا عاليا بين المجاميع قبل وبعد التبلور . النظامان لهما فجوة حافات مقبولة.sironaفجوة الحافات اقل من نظام imes icoreزيد من فجوة الحافات . أظهر نظام ان عملية البلورة ت االستنتاج: zahraa.docx j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry163 hard palate bone density and thickness determination using ct scan and their relationships with body compositions measured by bioelectrical impedance analysis for iraqi adult sample zahraa m. alfadily, b.d.s. (1) hadeel a. alhashimi, b.d.s., m.sc. (2) abstract background: this study was conducted to evaluate the hard palate bone density and thickness during 3rd and 4th decades and their relationships with body mass index (bmi) and compositions, to allow more accurate mini-implant placement. materials and method: computed tomographic (ct) images were obtained for 60 patients (30 males and 30 females) with age range 20-39 years. the hard palate bone density and thickness were measured at 20 sites at the intersection of five anterioposterior and four mediolateral reference lines with 6 and 3 mm intervals from incisive foramen and mid-palatal suture respectively. diagnostic scale operates according to the bioelectric impedance analysis principle was used to measure body weight; percentages of body fat, water, and muscle; bone mass; and basal and active metabolic rates. results: no significant difference in overall bone density and thickness of hard palate during 3rd and 4th decades. the gender should be considered in regard to bone thickness. cortical bone density and thickness showed a tendency to decrease posteriorly, while the cancellous bone density showed a tendency to increase posteriorly. in the mediolateral areas, no specific patterns were observed. with increasing bmi, the cortical bone density was increased. the relationships of bone density and thickness with most scale measurements were not significant. conclusion: mini-implants for orthodontic anchorage can be effectively placed in most areas of hard palate regarding the bone density. while regarding bone thickness, care should be taken during the planning of their placement in hard palate. a new classification for bone thickness of hard palate has been developed. keywords: bone density, bone thickness, computerized tomography, hard palate, orthodontic mini implant. (j bagh coll dentistry 2015; 27(2):163-172). introduction anchorage is of fundamental importance in orthodontic treatment (1). orthodontic miniimplants have expanded the scope of traditional orthodontic treatment because they provide an excellent alternative to traditional compliancedependent, tooth-borne anchorage methods (2). the non-tooth bearing area of the hard palate has been used as a host site for orthodontic implant anchorage because of sufficient bone quality and less possibility of root damage or interference with tooth movement during treatment in addition to the easy access of placing mini-screws in this area (3). furthermore, thick and keratinized palatal mucosa is related to less inflammation (4) and guarantees biomechanical stability for placement of miniscrews (5). bioelectrical impedance analysis (bia) is used to estimate body composition using the difference of conductivity based on the biological characteristic of tissue. conductivity is proportional to water and electrolyte and it is decreased when cell shape is closer to a round form. (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) assist. professor, department of orthodontics, college of dentistry, university of baghdad. adipose tissue is composed of round shape cell and contains relatively less water than other tissues like muscle, so conductivity is decreased according to the increase of body fat (6). as the bone density and thickness are two critical factors for success of mini-implant, this study aimed to obtain data that will serve as a guiding map to select the most suitable sites for placement of mini-implants in the hard palate regarding bone density (cortical and cancellous) and thickness during 3rd and 4th decades, and to assess if there is any relationships with bmi and different body compositions. materials and methods sixty iraqi patients were selected from the patients attending mri and ct department of alsader medical city in al-najaf and divided equally into: group i (20-29 years); and group ii (30-39 years). inclusion criteria included: 1. skeletal class ι with normal occlusion. 2. full set of dentition in the upper and lower left and/or right side (excluding third molar). 3. no erupted supernumerary and/or any impacted teeth within the area of measurement. j bagh college dentistry j bagh college dentistry pedodontics, orthodontics and preventive dentistry 4. no history of a systemic disease and no previous could affect bone health. 5. no syndromes of cleft palate, and no pathological lesion in the palate 6. no history of orthodontic treatment and/or orthognathic surgery. 7. no regular tobacco smoking and/or alcohol consumption. this study was approved by the scientific committee of college of dentistry university of baghdad. for each patient, informed consent was obtained before the start of examination. body weight and diagnostic scale measurements (body fat, water, muscle percentages; bone mass; and basal (bmr) and active (amr) metabolic rates were recorded while the subject wearing light clothes (during summer season), bare feet and was in a stable standing on a diagnostic scale (beurer, germany) which operates according to bi bmi was calculated. ct images were obtained by 64 detector ct scanner (philips, holland, brilliancetm ct, v palate bone density in hounsfield unit (hu) and thickness in millimeter (mm). the refer were determined to be from 0 to 24 mm at 6 mm intervals posterior to the level of the posterior margin of the incisive foramen and from 0 to 9 mm at 3 mm intervals lateral to the mid suture with the aid of equally sized grid of 3 mm intervals (figure 1). the measurements were made at the intersection points of the reference lines over 20 sites covering 216 mm right side de that refer there were no statistical significant differences measurements. at each determined point (sagittal view); the midpoint of the cortical bone thickness was selected to represent the cortical bone density, the density of the cancellous bone was measured at the trabeculae, loc between the two cortical plates, and the hard palate bone thickness (sum of cortical bone facing the oral cavity, cancellous bone and cortical bone facing the nasal cavity) was measured perpendicular to the horizontal plane. som these me the measured values were averaged for each sample, keeping specific to the designated area. according to the reference lines, there were 3 designated anteroposterior areas: anterior (0,6 mm); middle ( mm). likewise, 4 designated mediolateral areas: j bagh college dentistry pedodontics, orthodontics and preventive dentistry no history of a systemic disease and no previous chronic use of any medication that could affect bone health. no syndromes of cleft palate, and no pathological lesion in the palate no history of orthodontic treatment and/or orthognathic surgery. no regular tobacco smoking and/or alcohol consumption. this study was approved by the scientific committee of college of dentistry university of baghdad. for each patient, informed consent was obtained before the start of examination. body weight and diagnostic scale measurements (body fat, water, muscle entages; bone mass; and basal (bmr) and active (amr) metabolic rates were recorded while the subject wearing light clothes (during summer season), bare feet and was in a stable standing on a diagnostic scale (beurer, germany) which operates according to bi bmi was calculated. ct images were obtained by 64 detector ct scanner (philips, holland, brilliancetm ct, v 4.0) and used to measure hard palate bone density in hounsfield unit (hu) and thickness in millimeter (mm). the refer were determined to be from 0 to 24 mm at 6 mm intervals posterior to the level of the posterior margin of the incisive foramen and from 0 to 9 mm at 3 mm intervals lateral to the mid suture with the aid of equally sized grid of 3 mm rvals (figure 1). the measurements were made at the intersection points of the reference lines over 20 sites covering 216 mm right side depending on the previous studies that refer there were no statistical significant differences between the left and right side measurements. at each determined point (sagittal view); the midpoint of the cortical bone thickness was selected to represent the cortical bone density, the density of the cancellous bone was measured at the trabeculae, located halfway incisoapically between the two cortical plates, and the hard palate bone thickness (sum of cortical bone facing the oral cavity, cancellous bone and cortical bone facing the nasal cavity) was measured perpendicular to the horizontal plane. som these measurements were illustrated in f the measured values were averaged for each sample, keeping specific to the designated area. according to the reference lines, there were 3 designated anteroposterior areas: anterior (0,6 mm); middle (12 mm); and the posterior (18,24 mm). likewise, 4 designated mediolateral areas: j bagh college dentistry pedodontics, orthodontics and preventive dentistry no history of a systemic disease and no chronic use of any medication that could affect bone health. no syndromes of cleft palate, and no pathological lesion in the palate no history of orthodontic treatment and/or orthognathic surgery. no regular tobacco smoking and/or alcohol this study was approved by the scientific committee of college of dentistry university of baghdad. for each patient, informed consent was obtained before the start of examination. body weight and diagnostic scale measurements (body fat, water, muscle entages; bone mass; and basal (bmr) and active (amr) metabolic rates were recorded while the subject wearing light clothes (during summer season), bare feet and was in a stable standing on a diagnostic scale (beurer, germany) which operates according to bia principle. then ct images were obtained by 64 detector ct scanner (philips, holland, 4.0) and used to measure hard palate bone density in hounsfield unit (hu) and thickness in millimeter (mm). the refer were determined to be from 0 to 24 mm at 6 mm intervals posterior to the level of the posterior margin of the incisive foramen and from 0 to 9 mm at 3 mm intervals lateral to the mid suture with the aid of equally sized grid of 3 mm rvals (figure 1). the measurements were made at the intersection points of the reference lines over 20 sites covering 216 mm pending on the previous studies that refer there were no statistical significant between the left and right side at each determined point (sagittal view); the midpoint of the cortical bone thickness was selected to represent the cortical bone density, the density of the cancellous bone was measured at ated halfway incisoapically between the two cortical plates, and the hard palate bone thickness (sum of cortical bone facing the oral cavity, cancellous bone and cortical bone facing the nasal cavity) was measured perpendicular to the horizontal plane. som asurements were illustrated in f the measured values were averaged for each sample, keeping specific to the designated area. according to the reference lines, there were 3 designated anteroposterior areas: anterior (0,6 12 mm); and the posterior (18,24 mm). likewise, 4 designated mediolateral areas: j bagh college dentistry vol. 2 pedodontics, orthodontics and preventive dentistry no history of a systemic disease and no chronic use of any medication that no syndromes of cleft palate, and no pathological lesion in the palate. no history of orthodontic treatment and/or no regular tobacco smoking and/or alcohol this study was approved by the scientific committee of college of dentistry university of baghdad. for each patient, informed consent was obtained before the start of examination. body weight and diagnostic scale measurements (body fat, water, muscle entages; bone mass; and basal (bmr) and active (amr) metabolic rates were recorded while the subject wearing light clothes (during summer season), bare feet and was in a stable standing on a diagnostic scale (beurer, germany) a principle. then ct images were obtained by 64-slice multi detector ct scanner (philips, holland, 4.0) and used to measure hard palate bone density in hounsfield unit (hu) and thickness in millimeter (mm). the reference lines were determined to be from 0 to 24 mm at 6 mm intervals posterior to the level of the posterior margin of the incisive foramen and from 0 to 9 mm at 3 mm intervals lateral to the mid-palatal suture with the aid of equally sized grid of 3 mm rvals (figure 1). the measurements were made at the intersection points of the reference lines over 20 sites covering 216 mm2 in the left or pending on the previous studies (4,7 that refer there were no statistical significant between the left and right side at each determined point (sagittal view); the midpoint of the cortical bone thickness was selected to represent the cortical bone density, the density of the cancellous bone was measured at ated halfway incisoapically between the two cortical plates, and the hard palate bone thickness (sum of cortical bone facing the oral cavity, cancellous bone and cortical bone facing the nasal cavity) was measured perpendicular to the horizontal plane. some of asurements were illustrated in figure (2). the measured values were averaged for each sample, keeping specific to the designated area. according to the reference lines, there were 3 designated anteroposterior areas: anterior (0,6 12 mm); and the posterior (18,24 mm). likewise, 4 designated mediolateral areas: vol. 27(2), june 2015 pedodontics, orthodontics and preventive dentistry164 no history of a systemic disease and no chronic use of any medication that no syndromes of cleft palate, and no no history of orthodontic treatment and/or no regular tobacco smoking and/or alcohol this study was approved by the scientific committee of college of dentistry university of baghdad. for each patient, informed consent was body weight and diagnostic scale measurements (body fat, water, muscle entages; bone mass; and basal (bmr) and active (amr) metabolic rates were recorded while the subject wearing light clothes (during summer season), bare feet and was in a stable standing on a diagnostic scale (beurer, germany) a principle. then slice multidetector ct scanner (philips, holland, 4.0) and used to measure hard palate bone density in hounsfield unit (hu) and ence lines were determined to be from 0 to 24 mm at 6 mm intervals posterior to the level of the posterior margin of the incisive foramen and from 0 to 9 palatal suture with the aid of equally sized grid of 3 mm rvals (figure 1). the measurements were made at the intersection points of the reference in the left or (4,7-9), that refer there were no statistical significant between the left and right side at each determined point (sagittal view); the midpoint of the cortical bone thickness was selected to represent the cortical bone density, the density of the cancellous bone was measured at ated halfway incisoapically between the two cortical plates, and the hard palate bone thickness (sum of cortical bone facing the oral cavity, cancellous bone and cortical bone facing the nasal cavity) was measured e of igure (2). the measured values were averaged for each sample, keeping specific to the designated area. according to the reference lines, there were 3 designated anteroposterior areas: anterior (0,6 12 mm); and the posterior (18,24 mm). likewise, 4 designated mediolateral areas: mid (6 mm); lateral (9 mm) (figure 1). figure 2: thickness at different points (sagittal view). the most common tooth or the area between two teeth that appeared in each reference line was recorded. it was observed: anteroposteriorly (ap); line 0 line 6 line 12 line 18 line 24 mediolate line 0 line 3 line 6 line 9 june 2015 164 mid-palatal area (0 mm); medial (3 mm); middle (6 mm); lateral (9 mm) (figure 1). figure 1: grid, reference lines, points of measurements in ct (axial view). figure 2: measurement of bone density and thickness at different points (sagittal view). in order to make the evaluation more clinical, the most common tooth or the area between two teeth that appeared in each reference line was recorded. it was observed: anteroposteriorly (ap); line 0 distal third of the canine. line 6 distal margin of the first premolar. line 12 distal margin of the second premolars. line 18 distal third of the first molar. line 24 mesial third of the second molars. mediolateraly (ml); line 0 the area between two central incisors. line 3 distal third of the central incisor. line 6 mesial margin of the lateral incisor. line 9 distal margin of the lateral incisor. june 2015 palatal area (0 mm); medial (3 mm); middle (6 mm); lateral (9 mm) (figure 1). figure 1: grid, reference lines, points of measurements in ct (axial view). measurement of bone density and thickness at different points (sagittal view). in order to make the evaluation more clinical, the most common tooth or the area between two teeth that appeared in each reference line was recorded. it was observed: anteroposteriorly (ap); distal third of the canine. distal margin of the first premolar. distal margin of the second premolars. distal third of the first molar. mesial third of the second molars. raly (ml); the area between two central incisors. distal third of the central incisor. mesial margin of the lateral incisor. distal margin of the lateral incisor. hard palate bone palatal area (0 mm); medial (3 mm); middle (6 mm); lateral (9 mm) (figure 1). figure 1: grid, reference lines, points of measurements in ct (axial view). measurement of bone density and thickness at different points (sagittal view). in order to make the evaluation more clinical, the most common tooth or the area between two teeth that appeared in each reference line was distal third of the canine. distal margin of the first premolar. distal margin of the second premolars. distal third of the first molar. mesial third of the second molars. the area between two central incisors. distal third of the central incisor. mesial margin of the lateral incisor. distal margin of the lateral incisor. hard palate bone palatal area (0 mm); medial (3 mm); middle figure 1: grid, reference lines, points of measurements in ct (axial view). measurement of bone density and thickness at different points (sagittal view). in order to make the evaluation more clinical, the most common tooth or the area between two teeth that appeared in each reference line was distal margin of the first premolar. distal margin of the second premolars. mesial third of the second molars. the area between two central incisors. distal third of the central incisor. mesial margin of the lateral incisor. distal margin of the lateral incisor. hard palate bone j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry165 results there were no statistically significant differences in the overall bone density and bone thickness between group ι and ιι (table 1). according to this result, the matching measurements from both groups were combined. there was no statistically significant difference between the males and females in the bone density measurements; while a statistically significant difference between them in the bone thickness measurements (table 2). based on this result, the bone density measurements of males and females were combined. the males tended to show greater mean value than females with a statistically significant difference between them in the anterior area and in all mediolateral areas (table 3). comparisons of bone density and bone thickness for male and female among the three anteroposterior areas and the four mediolateral areas were performed by repeated measure analysis. there were a highly statistically significant difference (p<0.001) in bone density among these areas. consequently, cohen's d and bonferonni adjusted paired tests were done for each paired comparisons of these areas as illustrated in tables 4 and 5. according to anova trend, the relationship of bmi with cortical bone density was statistically significant, as with increasing the bmi, the cortical bone density increased, while with cancellous bone density and bone thickness for males and females was not (table 6). the relationship of the cortical bone density with diagnostic scale measurements was not statistically significant. the results of the cancellous bone density were similar to those of the cortical bone density except with body water percentage which was statistically significant. while the relationship of the bone thickness with bone mass and with bmr and amr was statistically significant (table 7). in the present study, the bone density of the designated areas of the hard palate was distributed according to misch’s(10) classification; while the bone thickness, according to the new classification that has been developed by this study (table 8 and 9) which includes: ∗ t1 thick bone bone thickness greater than 13 mm. ∗ t2 proper bone bone thickness value greater than7 to13 mm. ∗ t3 risky bone was bone thickness value between 4-7 mm. ∗ t4 improper bone bone thickness less than 4 mm. discussion the age range of the sample was selected to be (20-39 years) because before this age, the peak bone mass still not achieved (11), and after this age subsequent age-related bone loss appears (12).this may explain the no age difference. this study found no significant gender differences in the bone density. since males and females eat essentially the same types of food, the strains produced during mastication might be expected to be similar, as would bone density. other studies showed that females had greater palatal cortical bone density than males did (7,13). on the other hand, the present study found significant gender differences of bone thickness in the anterior area and in all mediolateral areas. this can be explained as males acquire more bone mass than females (a bigger-not a denserskeleton) (14), and may be attributed to the fact that the females have a reduced tongue strength compared to males (15). according to wolff’s law that states "bone structure is altered depending on the loads that are placed on it" (16), and as the tongue plays an important role in speech, mastication and swallowing by its contact with the hard palate (17). furthermore, the magnitude and duration of the tongue pressure were found to be significantly larger in the anteriomedian and smaller in the posteriomedian parts of hard palate compared to the other parts (18). ryu et al. (9) and gracco et al. (19) found no statistically significant differences due to gender in bone thickness of the hard palate. these differences with others may be explained by factors of race, hormones, and life style and also may belong to the difference in the measuring sites and/or the difference in the ct scanning machine setting. the result of present study showed that the cortical bone density and bone thickness had a tendency to decrease significantly anteroposteriorly, while the cancellous bone density had a tendency to increase. the mean of cancellous bone density in the posterior area was higher than that in the middle area but statistically not significant.menegaz et al.(20)foundthe data that support a role of mechanical loading in the determination of palatal morphology and that elevated masticatory loading developed hard palate with significantly greater bone area, and thicker anterior palates. role, magnitude and duration of tongue pressure were significant in the anteromedian part of hard palate (17,18). furthermore and just as could be expected from the triangular sagittal cross section of the palate, the result of present study regarding cortical bone density and thickness can be explained as the anterior area is nearest to masticatory function of j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry166 the teeth and tongue pressure than middle and posterior areas. about the cancellous bone density, the anterior area had higher bone thickness than the middle and posterior areas, so the decrease in the thickness of bone is associated with more concentrated trabeculae. the result of present study is in agreement with han et al. (7) and moon et al. (13) regarding the cortical bone density, and in disagreement with han et al. (7) regarding the cancellous bone density who found it decreasing posteriorly. regarding the bone thickness, the result is in agreement with others (8,9,19,21-23). the bone density and thickness didn't take organized pattern mediolaterly, as mid-palatal area showed lowest cortical bone density and highest cancellous bone density and bone thickness. medial area showed highest cortical bone density and lowest cancellous bone density, while middle area showed lowest bone thickness. direct comparison with other studies is difficult since there was no previous study investigating the area of mid-palatal suture and there is difference in the way of designing mediolateral areas. concerning mid-palatal suture, in the immediate postnatal period, the fine cancellous bone of the palate was replaced by bone having a cortex and medullary spaces, and the medial ends of the palatal processes gradually thickened. during the first 2 years, the inferior cortical layer remained cancellous in nature due to the rapid deposition of bone on its oral surface; the intermaxillary suture increased markedly in height and became narrower (24). this fact can explain that the bone in the mid-palatal suture has specific characteristics differ from that in the others mediolateral areas. explanation of other results related to mediolateral areas may be attributed to the facts mentioned previously about the shape of hard palate bone in coronal section, effect of tongue pressure on the cortical bone density and bone thickness, and as cancellous bone in the lateral area lies adjacent to the roots of the maxillary teeth and is subjected to the stress of masticatory forces. the sample of present study included normal, overweight and obese categories of the international classification of bmi (25). it was found that obesity leads to upper airway narrowing due to enlargement of soft palate, lateral pharyngeal walls, para-pharyngeal fat pads, and tongue (26,27). furthermore, the weight of a muscle reflects the forces that it exerts on bones to which it is attached and that muscle weight is an important determinant of bone mass (28). accordingly, the result of this study may be explained as that increase in bmi is associated with an enlargement of tongue which implied more pressure on the cortical bone. there is no previous study examining this relationship. in this study, the hard palate bone density was not related to the body composition, except the cancellous bone density in relation to the body water percentage which may be belong to the fact that the water ratio is higher in trabecular than in cortical bones (29). the relationships of bone thickness with bone mass, bmr and amr were statistically significant. there is no previous study examining these relationships. this result may be explained as if all individuals had the same size of hard palate whatever their skeleton size, some would have hard palate that was inadequate for the task and others would be at a disadvantage through having hard palate that was significantly heavier than it needed to be. additionally, the bmr and amr are influenced by weight and height (30). so it is expected that the heavier individuals (including their hard palate) will have fastest bmr and amr. the bone density measurements of the present study were distributed according to misch’s (10) classification who classified the bones into 5 categories according to density. consequently, the mean of cortical bone density in the anteroposterior and mediolateral areas was d2 (850-1250hu), while the mean of cancellous bone density in the anteroposterior and mediolateral areas was d3 (350-850hu). there is no previous classification of bone thickness. in the palate, the big challenge is the length of miniscrews.23 so the present study classified the bone thickness into four categories depending on miniscrew length as there must be sufficient bone thickness to receive the functional part of the mini-screw, without perforating the nasal cavity plus a safety zone of 1 mm. t1 and t2 categoriesare classified as there will be sufficient bone thickness to receive the functional part of the mini-screw, ranging from 6 to 12 mm in length, without perforating the nasal cavity (4,8,19) and a safety margin of 1 mm is recommended (31). t3 category is classified asthe limited availability of palatal bone height which was the reason for the development of special short palatal implants for orthodontic anchorage (3 to 6 mm long) (32). t4 category is classified as the shortest endosseous part of short palatal implant is 3 mm long (31). also it has been reported that a risky region for palatal implant placement is one with a height of less than 4 mm (4,33). so t4 is considered as improper bone for placement of mini-screw. the present study found that anteroposteriorly, the j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry167 mean of bone thickness for males and females in the anterior area was t2, in the middle area was t3, while in the posterior area was t3 for males and was t4 for females. mediolaterally, the mean of bone thickness in the mid-palatal area was t2 for males and was t3 for females. in other mediolateral areas, the mean of bone thickness for both males and females was t3. it was concluded that bone thickness is more important than the bone density to be considered when planning to place mini-implant for orthodontic anchorage in the hard palate. a new classification for bone thickness of the hard palate has been developed and a preliminary guiding map to select the most suitable sites for placement of mini-implants in the hard palate was established. references 1. wu ty, kuang sh, wu ch. factors associated with the stability of mini-implants for orthodontic anchorage: a study of 414 samples in taiwan. j oral maxillofac surg 2009; 67(8): 1595-9. 2. favero l, brollo p, bressan e. orthodontic anchrage with specific fixtures: related study analysis. am j orthod dentofacial orthop 2002; 122: 84-94. 3. jung ba, kunkel m, gollner p, liechti t, wehrbein h. success rate of second-generation palatal implants. angle orthod 2009; 79: 85-90. 4. kang s, lee s, ahn s, heo m, kim t. bone thickness of the palate for orthodontic mini-implant anchorage in adults. am j orthod dentofacial orthop 2007; 131: s74-80. 5. kyung sh, hong sg, park yc. distalization of maxillary molars with a midpalatal miniscrew. j clin orthod 2003; 37: 22-6. 6. gang j. suitable method to body fat assessment and follow-up examination. the 10th workshop of kosso in 2005; 261-9. 7. han s, bayome m, lee j, lee yj, song hh, kook ya. evaluation of palatal bone density in adults and adolescents for application of skeletal anchorage devices. angle orthod 2012; 82: 625-31. 8. baumgaertel s. quantitative investigation of palatal bone depth and cortical bone thickness for miniimplant placement in adults. am j orthod dentofacial orthop 2009; 136: 104-108. 9. ryujh, park jh, thu tvt, bayome m, kim yj, ah kook y. palatal bone thickness compared with conebeam computed tomography in adolescents and adults for mini-implant placement. am j orthod dentofacial orthop 2012; 142: 207-12. 10. misch ce. density of bone: effect on treatment plans, surgical approach, healing, and progressive bone loading. int j oral implantol 1990; 6(2): 23-31. 11. gardner dg, shoback d. greensspan's basic and clinical endocrinology. 9th ed. mcgraw-hill, 2011. 12. riggs bl, melton ilj, robb ra, camp jj, atkinson ej, peterson jm, rouleau pa, mccollough ch, bouxsein ml, khosla s. a population-based study of age and sex differences in bone volumetric density, size, geometry and structure at different skeletal sites. j of bone mineral research 2004; 19(12): 1945-54. 13. moon ch, park hk, nam js, im js, baek sh. relationship between vertical skeletal pattern and success rate of orthodontic mini-implants. am j orthod dentofacial orthop 2010; 138(1): 51-7. 14. callewaert f, venken k, kopchick jj, torcasio a, lenthe ghv, boonen s, vanderschueren d. sexual dimorphism in cortical bone size and strength but not density is determined by independent and timespecific actions of sex steroids and igf-1: evidence from pubertal mouse models. american society for bone and mineral research 2010; 25(3): 617-26. 15. youmans sr, youmans gl, stierwalt jag. differences in tongue strength across age and gender: is there a diminished strength reserve? dysphagia 2009; 24 (1): 57-65. 16. wolff j. das gestetz der transformation der knocken .hirshewold, berlin 1892. 17. hori k, ono t, nokubi t. coordination of tongue pressure and jaw movement in mastication. j dent res 2006; 85(2): 187-91. 18. ono t, hori k, nokubi t. pattern of tongue pressure on hard palate during swallowing. dysphagia 2004; 19(4): 259-264. 19. gracco a, lombardo l, cozzani m, siciliani g. quantitative cone-beam computed tomography evaluation of palatal bone thickness for orthodontic miniscrew placement. am j orthod dentofacial orthop 2008; 134: 361-9. 20. menegaz ra, sublett sv, figueroa sd, hoffman tj, ravosa mj. phenotypic plasticity and function of the hard palate in growing rabbits. the anatomical record 2009; 292: 277-84. 21. jayakumar g, rajkumar, biju t, george ma, krishnaswamy nr. quantitative assessment of palatal bone thickness in an ethnic indian population: a computed tomography study. indian j dent res 2012; 23(1): 49-52. 22. farnsworth d, rossouw pe, ceen rf, buschang ph. cortical bone thickness at common miniscrew implant placement sites. am j orthod dentofacial orthop 2011; 139(4): 495-503. 23. marquezan m, nojima li, freitas aoa, baratieri c, júnior ma, nojima mcg, araújo mts. tomographic mapping of the hard palate and overlying mucosa. brazilian oral research 2012; 26(1): 36-42. 24. latham ra. the development, structure and growth pattern of the human mid-palatal suture. j anat 1971; 108(1): 31-41. 25. who. obesity: preventing and managing the global epidemic. report of a who consultation. who technical report series 894. geneva: world health organization, 2000. 26. horner rl, mohiaddin rh, lowell dg, lowell dg, shea s, burman ed. sites and sizes of fat deposits around the pharynx in obese patients with obstructive sleep apnoea and weight matched controls. european respiratory j 1989; 2(7): 613-22. 27. chi l, comyn fl, mitra n, reilly mp, wan f, maislin g, chmiewski l, thorne-fitzgerald md, victor un, pack ai, schwab j. identification of craniofacial risk factors for obstructive sleep apnoea using three-dimensional mri. european respiratory journal 2011; 38(2): 348-58. 28. doyle f, brown j, lachance c. relation between bone mass and muscle weight. the lancet 1970; 295(7643): 391-3. j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry168 29. gong jk, arnold js, cohn sh. composition of trabecular and cortical bone. the anatomical record 1964; 149(3): 325-331. 30. guyton ac, hall je. text book of medical physiology. 12th ed. elsevier 2010. 31. king ks, lam ew, faulkner mg, heo g, major pw. vertical bone volume in the paramedian palate of adolescents: a computed tomography study. am j orthod dentofacial orthop 2007; 132: 783-8. 32. wehrbein h, feifel h, diedrich p. palatal implant anchorage reinforcement of posterior teeth: a prospective study. am j orthod dentofacial orthop 1999; 116: 678-86. 33. bernhart t, vollgruber a, gahleitner a, dortbudak o, haas r. alternative to the median region of the palate for placement of an orthodontic implant. clin oral implants res 2000; 11: 595-601. .table 1: comparison between the two groups in bone density (hu) (cortical and cancellous) and bone thickness (mm) measurements. b on e d en si ty descriptive statistics male (n=30) age group difference female (n=30) age group difference group ι (n=15) group ιι (n=15) p-value group ι (n=15) group ιι (n=15) p-value c or ti ca l range 821.00 860.20 0.72 (ns) 936.10 953.00 0.6 (ns) 1287.4 1290.7 1299.5 1131.5 mean 1121.5 1103.7 1153.1 1131.5 sd 140.65 128.11 113.63 106.72 c an ce llo us range 546.30 463.30 0.29 (ns) 615.40 539.30 0.12 (ns) 994.40 913.10 1048.3 971.10 mean 751.70 700.10 782.20 711.20 sd 131.31 128.02 126.48 114.23 b on e th ic kn es s range 3.9000 5.0000 0.21 (ns) 4.0000 4.2000 0.73 (ns) 9.5000 9.6000 7.5000 7.3000 mean 6.400 7.1000 5.7000 5.8000 sd 1.4700 1.3700 1.1900 0.9900 table 2: gender difference in the bone density (hu) (cortical and cancellous) and bone thickness (mm) measurements of the hard palate. descriptive statistics male (n=30) female (n=30) gender difference (p-value) b on e d en si ty c or ti ca l range 821.00 936.10 0.35 (ns) 1290.7 1313.5 mean 1112.6 1142.3 sd 132.50 108.86 c an ce ll ou s range 463.30 539.30 0.53 (ns) 994.40 1048.3 mean 725.90 746.70 sd 130.09 123.79 b on e t hi ck ne ss range 3.9000 4.0000 0.005 (s) 9.6000 7.5000 mean 6.7000 5.8000 sd 1.4400 1.0800 j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry169 table 3: gender difference in the bone thickness (mm) of different areas of the hard palate. الخالصة بشكل التقویمیة الزرعات للسماح بوضع مكوناتھو كتلةالجسم دلیل معوعالقتھما العمر من والرابع العقدالثالث خاللالحنك الصلب كثافة وسمك عظملتقییم :الخلفیة .أكثر دقة الحنك الصلب وسمكھ كثافة عظم. سنة٢٩-٢٠تتراوحأعمارھمبین) ناثاأل من٣٠منالذكورو٣٠(شخص ٦٠المفراس الحلزوني لجمعت صور :المواد واألدوات من الثقب الحاد والدرز الحنكي الوسطي )ملیمیتر( ٣و ٦موقع عند تقاطع خمس خطوط إشارة أمامیة خلفیةمع أربع خطوط إشارة قریبة جانبیة بمسافة ٢٠قیست ل الماء والعضالت؛ كتلة العظم ،كھربائیة استخدم لقیاس وزن الجسم؛ النسبة المئویة لدھون الجسمالمیزان التشخیصیالذي یعمل بمبدء تحلیل الممانعة ال.على التوالي .النشیطة األساسیة والنسبةاألیضیة والنسبةاألیضیة ینبغیالنظرفیالجنسینفیمایتعلقبسماكةعظم . الحنك الصلب وسمكھ الكلیة خالل العقد الثالث والرابع من العمر كثافةعظم في إحصائیة داللة ذات التوجدفروق:النتائج بالنسبة للمناطق القریبة الجانبیة، . آبینت میول للتزاید خلفی اإلسفنجيبینما كثافة العظم ،آبینت كثافة العظم القشري وسمك العظم میول للتناقص خلفی. الحنك الصلب كثافة العظموسمك العظم أن العالقة بینلقد تبین .تحدث مع الزیادة في دلیل كتلة الجسم كثافة العظم القشريأن ھنالك تزاید في لقدلوحظ. لم یالحظ نموذج مخصص .إحصائیة داللة ذاتمع قیاسات المیزان التشخیصي معظمھا لیست لسمك العظم یجب توخي الحذر عند التخطیط آوفق بینما ،كثافة العظمل آالحنك الصلب وفقالزرعات التقویمیة من الممكن وضعھا في معظم مناطق عظم :االستنتاج تصنیف جدید لسمك عظم الحنك الصلب تم وضعھ. الحنك الصلبعظم الزرعات التقویمیة في لوضع b on e t hi ck ne ss areas descriptive statistics male (n=30) female (n=30) gender difference (p-value) a nt er op os te ri or a re as anterior area range 5.10 6.40 0.002 (hs) 15.2 12.3 mean 10.3 8.70 sd 2.15 1.65 middle area range 2.50 2.20 0.06 (ns) 8.10 7.00 mean 5.00 4.30 sd 1.49 1.20 posterior area range 2.30 2.10 0.11 (ns) 6.0 6.30 mean 4.00 3.50 sd 1.22 0.94 m ed io la te ra l a re as mid-palatal area range 6.10 5.10 0.013 (hs) 12.00 10.3 mean 8.60 7.70 sd 1.55 1.30 medial area range 3.60 3.10 0.028 (hs) 9.80 7.80 mean 6.30 5.40 sd 1.66 1.30 middle area range 2.80 2.70 0.003 (hs) 8.30 6.70 mean 5.70 4.60 sd 1.43 1.09 lateral area range 3.30 3.00 0.012 (hs) 9.10 8.80 mean 6.30 5.30 sd 1.63 1.38 j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry170 table 4: comparisons between the areas of the hard palate in bone density (hu). descriptive statistics areas mean difference cohen s d pvalue anterior middle a nt er op os te ri or a re a b on e d en si ty cortical mean 1246.4 1104.8 141.6 1.06 (le) 0.001 (hs) sd 113.55 150.40 cancellous mean 633.20 775.30 -142.1 -0.83 (le) 0.001 (hs) sd 124.50 207.44 anterior posterior b on e d en si ty cortical mean 1246.4 1019.8 226.6 1.63 (le) 0.001 (hs) sd 113.55 160.78 cancellous mean 633.20 819.80 -186.6 -1.25 (le) 0.001 (hs) sd 124.50 169.70 middle posterior b on e d en si ty cortical mean 1104.8 1019.8 85.00 0.55 (me) 0.001 (hs) sd 150.40 160.78 cancellous mean 775.30 819.80 -44.50 -0.23 (se) 0.2 (ns) sd 207.44 169.70 m ed io la te ra l a re as mid-palatal medial b on e d en si ty cortical mean 1099.6 1183.3 -83.7 -0.6 (me) 0.001 (hs) sd 116.70 160.78 cancellous mean 832.90 637.90 195 1.22 (le) 0.001 (hs) sd 112.38 195.51 mid-palatal middle b on e d en si ty cortical mean 1099.6 1113.2 -13.6 -0.09 (se) 1 (ns) sd 116.70 165.76 cancellous mean 832.90 757.30 75.6 0.47 (me) 0.028 (hs) sd 112.38 199.30 mid-palatal lateral b on e d en si ty cortical mean 1099.6 1113.6 -14.00 -0.11 (small effect) 1 (ns) sd 116.70 144.99 cancellous mean 832.90 717.00 115.9 0.79 (me) 0.001 (hs) sd 112.38 174.40 medial middle b on e d en si ty cortical mean 1183.3 1113.2 70.10 0.43 (me) 0.002 (hs) sd 160.78 165.76 cancellous mean 637.90 757.30 -119.4 -0.6 (me) 0.001 (hs) sd 195.51 199.30 medial lateral b on e d en si ty cortical mean 1183.3 1113.6 69.7 0.46 (me) 0.006 (hs) sd 160.78 144.99 cancellous mean 637.90 717.00 -79.1 -0.43 (me) 0.041 (hs) sd 195.51 174.40 middle lateral b on e d en si ty cortical mean 1113.2 1113.6 -0.40 0 (ne) 1 (ns) sd 165.76 144.99 cancellous mean 757.30 717.00 40.3 0.22 (se) 0.41 (ns) sd 199.30 174.40 j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry171 table 5: comparisons between the areas of the hard palate in bone thickness (mm) for male and female. descriptive statistics areas for male mean difference cohen s d pvalue areas for female mean difference cohen s d pvalue anterior middle anterior middle a nt er op os te ri or a re as mean 10.3 5.00 5.3 2.86 (le) 0.001 (hs) 8.70 4.30 4.4 3.o6 (le) 0.001 (hs) sd 2.15 1.49 1.65 1.20 anterior posterior anterior posterior mean 10.3 4.00 6.3 3.60 (le) 0.001 (hs) 8.70 3.50 5.2 3.88 (le) 0.001 (hs) sd 2.15 1.22 1.65 0.94 middle posterior middle posterior mean 5.00 4.00 1.0 0.74 (me) 0.001 (hs) 4.30 3.50 0.8 0.74 (me) 0.001 (hs) sd 1.49 1.22 1.20 0.94 mid-palatal medial midpalatal medial m ed io la te ra l a re as mean 8.60 6.30 2.3 1.43 (le) 0.001 (hs) 7.70 5.40 2.3 1.77 (le) 0.001 (hs) sd 1.55 1.66 1.30 1.30 mid-palatal middle midpalatal middle mean 8.60 5.70 2.9 1.95 (le) 0.001 (hs) 7.70 4.60 3.1 2.58 (le) 0.001 (hs) sd 1.55 1.43 1.30 1.09 mid-palatal lateral midpalatal lateral mean 8.60 6.30 2.3 1.45 (le) 0.001 (hs) 7.70 5.30 2.4 1.79 (le) 0.001 (hs) sd 1.55 1.63 1.30 1.38 medial middle medial middle mean 6.30 5.70 0.6 0.39 (me) 0.001 (hs) 5.40 4.60 0.8 0.67 (me) 0.001 (hs) sd 1.66 1.43 1.30 1.09 medial lateral medial lateral mean 6.30 6.30 0.0 0.0 (ne) 1 (ns) 5.40 5.30 0.1 0.07 (se) 1 (ns) sd 1.66 1.63 1.30 1.38 middle lateral middle lateral mean 5.70 6.30 -0.6 -0.39 (me) 0.001 (hs) 4.60 5.30 -0.7 0.56 (me) 0.001 (hs) sd 1.43 1.63 1.09 1.38 table 6: the relationship of the bone density (cortical and cancellous) and bone thickness (for male and female) with bmi. descriptive statistics bmi (kg/m2)-categories anova trendp-value normal (18.5-24.9) overweight (25-29.9) obese (≥30) b on e d en si ty c or ti ca l n=60 n=24 n=23 n=13 0.016 (s) range 821.00 860.20 1026.3 1313.5 1299.5 1290.7 mean 1091.1 1129.5 1190.8 sd 137.00 111.30 80.600 c an ce llo us n=60 n=24 n=23 n=13 0.22 (ns) range 463.30 586.40 605.00 994.40 1048.3 913.10 mean 708.50 750.20 763.00 sd 146.80 113.60 104.20 b on e t hi ck ne ss m al e n=30 n=16 n=7 n=7 0.76 (ns) range 3.9 5.8 5.2 9.5 9.6 8.2 mean 6.5 7.1 6.7 sd 1.6 1.4 1.3 f em al e n=30 n=8 n=16 n=6 0.78 (ns) range 4.9 4.0 4.1 7.5 7.5 7.3 mean 6.0 5.6 5.9 sd 1.0 1.1 1.1 j bagh college dentistry vol. 27(2), june 2015 hard palate bone pedodontics, orthodontics and preventive dentistry172 table 7: the relationship of the bone density (cortical and cancellous) and bone thickness with diagnostic scale measurements. descriptive statistics variables fat% water% muscle% bone mass bmr amr c or ti ca l b on e d en si ty lowest quartile (≤1042.5) n=15 mean 27.5 52.9 39.3 10.0 1709.3 2380.4 sd 5.70 4.16 4.54 2.46 243.79 379.23 interquartile range (1042.6 – 1209.7)n=30 mean 29.3 51.6 37.7 9.10 1649.9 2260.4 sd 8.11 5.92 6.09 2.30 253.14 376.68 highest quartile (1209.8 ) n=15 mean 29.3 52.2 37.7 9.20 1644.3 2276.8 sd 7.15 6.19 5.51 2.26 229.98 381.53 p-value (anova trend) 0.5 (ns) 0.73 (ns) 0.46 (ns) 0.37 (ns) 0.47 (ns) 0.46 (ns) c an ce llo us b on e d en si ty lowest quartile (≤638.1) n=15 mean 30.1 51.0 37.7 9.80 1699.7 2344.2 sd 7.08 5.17 5.65 2.95 334.08 487.39 interquartile range (638.2 – 833.4) n=30 mean 30.0 51.0 37.1 9.30 1654.6 2285.0 sd 6.58 5.17 5.04 2.17 214.86 333.72 highest quartile (833.5 ) n=15 mean 25.4 55.1 40.5 9.10 1644.5 2263.7 sd 8.10 6.51 6.07 1.98 197.23 349.18 p-value (anova trend) 0.07 (ns) 0.043 (s) 0.16 (ns) 0.39 (ns) 0.54 (ns) 0.56 (ns) b on e t hi ck ne ss lowest quartile (≤5.1)n=15 mean 29.0 52.4 37.0 8.30 1548.1 2104 sd 8.23 6.85 6.13 1.67 154.33 271.67 interquartile range (5.2 – 7.2) n=30 mean 28.8 52.0 38.2 9.40 1667.8 2309.4 sd 7.01 5.11 5.47 2.22 236.86 368.72 highest quartile (7.3 ) n=15 mean 28.8 52.0 39.1 10.5 1769.7 2455.1 sd 7.29 5.32 5.27 2.68 285.79 414.22 p-value (anova trend) 0.93 (ns) 0.84 (ns) 0.32 (ns) 0.009 (hs) 0.012 (s) 0.01 (s) table 8: classification of bone density and thickness of hard palate for the anteroposterior areas. anterioposterior areas descriptive statistics bone density bone thickness cortical cancellous male female anterior area range d2-d1 d3-d2 t3-t1 t3-t2 mean d2 d3 t2 t2 middle area range d3-d1 d3-d2 t4-t2 t4-t2 mean d2 d3 t3 t3 posterior area range d3-d2 d3-d2 t4-t3 t4-t3 mean d2 d3 t3 t4 table 9: classification of bone density and thickness of hard palate for the mediolateral areas. mediolateral areas descriptive statistics mid-palatal area medial area middle area lateral area b on e d en si ty cortical range d3-d1 d3-d1 d3-d1 d3-d1 mean d2 d2 d2 d2 cancellous range d3-d2 d4-d2 d3-d2 d4-d2 mean d3 d3 d3 d3 b on e t hi ck ne ss male range t3-t2 t4-t2 t4-t2 t4-t2 mean t2 t3 t3 t3 female range t3-t2 t4-t2 t4-t3 t4-t2 mean t3 t3 t3 t3 j bagh college dentistry vol. 33(4), december 2021 evaluation of the antifungal 1 evaluation of the antifungal activity of nasturtium officinale (watercress) oil with calcium hydroxide against candida albicans isolated from root canal mustafa w. abdul kareem (1), zainab a. al dhaher (2) https://doi.org/10.26477/jbcd.v33i4.3012 abstract background: the interest in herbal extracts as antimicrobial agents has increased over the past few years in endodontic therapy. nasturtium officinale (watercress) is a promising plant with great medicinal values. this study aimed to investigate the antifungal activity of watercress oil in combination with calcium hydroxide against candida albicans as intracanal medicament. materials and methods: candida albicans was isolated from patients with necrotic root canal or failed root canal treatment. the sensitivity of candida albicans to different concentrations of watercress oil extract was determined by using the agar well diffusion method in comparison with calcium hydroxide paste. the agar plate method was used to determine the minimum fungicidal concentration (mfc) of the tested oil against the fungus. the combination of the oil extract of nasturtium officinale with calcium hydroxide was evaluated and compared to calcium hydroxide paste with iodoform by using the agar well diffusion method. results: the oil extract exhibited antifungal activity against candida albicans, this activity was found to be increased as the concentration of extract increased. the tested combination of watercress oil extract with calcium hydroxide revealed larger inhibition zones than the ones formed by each tested agent individually. conclusion: the oil extract of nasturtium officinale is active against candida albicans suggesting its potential to be used as an intracanal medicament alone or in combination with calcium hydroxide. keywords: nasturtium officinale, oil extract, candida albicans, intracanal medicaments. (received: 22/7/2021, accepted: 29/8/2021) introduction successful root canal treatment is accomplished by complete disinfection of root canals and removal of debris by efficient delivery of antimicrobial agents. (1) the persistence of microorganisms and their resistance to the disinfection measures are the major cause of root canal treatment failure. (2) enterococcus faecalis is the most commonly associated bacterial species with periapical infection and failure of root canal treatment.(3) candida albicans is the most isolated fungus from root canal system which plays a major role in root canal treatment failure. (4) all this can occur as a result of inefficient shaping of the canals, absence of apical sealing, voids in the restoration of the clinical crown, missed canals. (5) (1) ma student, al hadi university college, dentistry department. baghdad, iraq (2). professor, department of basic sciences, college of dentistry, university of baghdad. corresponding author: mustafa_code108@yahoo.com intracanal medications with antimicrobial action are used with the intention of maximizing the disinfection of root canals.(6) calcium hydroxide is the most commonly used intracanal medicament ;researchers investigated its combination with a plethora of vehicles in order to enhance its antimicrobial properties significantly.(7) candida albicans has been repeatedly recovered from the canals of retreatment cases especially the ones with persistent infections.(8) it possesses several virulence factors such as adherence to many surfaces including dentin and root filling materials, produces hydrolytic enzymes, undergoes morphologic transition, form biofilms, evades and modulates the host defense.(9) a growing resistance of endodontic pathogens to the common antimicrobials has been noticed and led to an increasing efforts to the production of high-value phytochemicals that could be used as irrigants and intracanal medicaments. nasturtium officinale (watercress) plant is currently received a lot of attention and many studies reported its beneficial properties and confirmed it therapeutic https://doi.org/10.26477/jbcd.v33i4.3012 mailto:mustafa_code108@yahoo.com j bagh college dentistry vol. 33(4), december 2021 evaluation of the antifungal 2 potential for the treatment of many oral diseases.(10) materials and methods oil extract preparation nasturtium officinale (watercress) was purchased from the local market in baghdad city, iraq. after cleaning and washing, only the leaves were collected, air dried, grinded and stored in airtight containers and sent to extraction. the extraction was prepared according to the method described in the study of mahdavi et al. (11) patient selection and sample collection this study was ethically approved by the research ethics committee at college of dentistry/ university of baghdad . it included 30 patients aged (25-45 years) with necrotic or failed treated teeth. the sample was collected after complete isolation of the selected teeth with rubber dam, removal of carious lesions, access opening to the canals and initial instrumentation by iso type k-files and af rotary file #20/04 (fanta/ china) without any irrigants were made. sterile saline solution was further applied and agitated with the last file to form a microbial suspension. (12) isolation of candida albicans paper points were sterilized by autoclave and then introduced into the canal and kept for one minute until the canal was dry. thereafter, these paper points were transferred into a tube containing sterile transport media (amies) and sent to the laboratory for isolation and identification. (13,14) after been vortexed, the collected samples were streaked on sabouraud dextrose agar (sda) media and incubated aerobically at 37°c for 48 hours. identification of candida albicans c. albicans identification was based on microscopical examination (gram stain), colony morphology (on sabouraud dextrose agar) and germ tube formation test. in vitro experiments antifungal activity of different concentrations of nasturtium officinale oil extract against c. albicans: agar well diffusion method was employed to assess the antifungal activity of the extract. the tested oil was prepared in four concentrations of 5, 10, 15 and 20 mg/ml in 10% dimethyl sulfoxide (dmso). six wells were prepared in mueller hinton agar (mha) plates, four of them filled with 100μl of the different concentrations of the oil extract and the others with calcium hydroxide paste and dmso as positive and negative controls respectively. the plates were incubated aerobically for 24 hrs., at 37°c. determination of minimum fungicidal concentration (mfc) of the tested oil on c. albicans: final concentrations of 10, 5, 2.5, 1.25, 0.625 were prepared from nasturtium officinale oil and incorporated into a sterile bhi.a to get 10 ml of agar and the tested oil. the experimental bottles were poured into sterile petridishes for a period until they became hard then inoculated by streaking loop full from activated bacteria. the petridishes were incubated for 24 hrs. at 37°c including the control plate (negative control) which contained bhi.a with microbial inoculum without the addition of the tested oil, and (positive control) plate which contained bhi.a with different concentration of the tested oil without bacterial inoculum. the mfc was determined as the lowest concentration of the oil that killed the fungus. (15) test the combination effect of nasturtium officinale oil with calcium hydroxide on c. albicans in comparison to calcium hydroxide paste with iodoform: agar well diffusion method was employed to assess the antifungal activity of the combination of oil extract with calcium hydroxide paste. the experiment involved mixing equal volume 1:1 of the tested oil with calcium hydroxide paste. mfc of oil extract and calcium hydroxide paste with iodoform (readymade) were included in the wells. statistical analysis data were analyzed using spss (statistical package of social science) software version 25. a one-way anova test was used to compare the inhibition zone among different concentrations of the tested oil. tukey's hsd test was used to test any statistically significant difference between each two concentrations of the tested extract. independent sample t-test was used to compare the inhibition zone between the study and control group. results identification of c. albicans: c. albicans appeared as small oval gram-positive or budding yeast cells under microscope. on sda, it j bagh college dentistry vol. 33(4), december 2021 evaluation of the antifungal 3 was developed as creamy, white, smooth, pasty convex with yeast smell odor and finally it showed a positive result of germ tube formation. antifungal activity of different concentrations of nasturtium officinale oil extract against c. albicans: c. albicans was sensitive to all concentrations of nasturtium officinale oil extract and growth inhibition zones were formed. the diameter of the growth inhibition zone found to increase as the concentrations of the oil increased. in contrary to dmso, calcium hydroxide paste revealed antifungal activity against c. albicans. analysis of variance (anova) test was used and the results showed that there was a highly significant difference (p ≤ 0.01) among the studied concentrations of oil extract and calcium hydroxide paste (table 1 and figure 1). figure 1: antifungal activity of nasturtium officinale oil and calcium hydroxide paste (control) against candida albicans. table 1: comparison among the antifungal activity (inhibition zone diameter in mm) of nasturtium officinale oil and calcium hydroxide paste (control) against candida albicans. oil conc. mean s.d. min. max. f-test p-value 20 mg/ml 20.2 2.440 17 25 15 mg/ml 18 1.826 16 21 32.453 0.000* 10 mg/ml 17 2.160 14 20 5 mg/ml 14.9 2.025 12 18 control 11 0.816 10 12 [*] highly significant since the difference was highly significant among extract concentrations and the control, a statistical comparison had been done by using tukey's hsd test between each two concentrations of nasturtium officinale oil extract .the results demonstrated that there was a highly significant difference (p≤0.01) among oil extract concentrations except between 20 mg/ml and 15 mg/ml, 15 mg/ml and 10 mg/ml, 10 mg/ml and 5 mg/ml the difference was nonsignificant (p > 0.05) (table 2). table 2: comparison among the antifungal activity (inhibition zone diameter in mm) between each two concentration of nasturtium officinale oil and calcium hydroxide paste (control) against candida albicans. oil conc. compared with mean difference pvalue 20 mg/ml 15 mg/ml 2.2 0.099** 10 mg/ml 3.2 0.005* 5 mg/ml 5.3 0.000* control 9.2 0.000* 15 mg/ml 10 mg/ml 1 0.776** 5 mg/ml 3.1 0.007* control 7 0.000* 10 mg/ml 5 mg/ml 2.1 0.127** control 6 0.000* 5 mg/ml control 3.9 0.000* [*] highly significant [**] non significant determination of minimum fungicidal concentration (mfc) of the tested oil on c. albicans: the minimum fungicidal concentration of oil extract was 2.5 mg/ml. the combination effect of nasturtium officinale oil with calcium hydroxide on c. albicans in comparison to calcium hydroxide paste with iodoform: c. albicans was sensitive to the combination of minimum fungicidal concentration of the tested oil and calcium hydroxide paste and growth inhibition zones were formed. independent sample t-test was used to compare the inhibition zone between the studied combination and calcium hydroxide paste with iodoform as a control. the results revealed that there was a highly significant difference (p ≤ 0.01) between the study and the control group (table 3). j bagh college dentistry vol. 33(4), december 2021 evaluation of the antifungal 4 table 3: comparison between the antifungal activity of the study and control groups against candida albicans. inhibition zones against c. albicans study group control group t-test p-value mean s.d. mean s.d. [*] highly significant another statistical comparison was done by using independent sample t-test to study the effect of the studied combination and compare the inhibition zone of the tested oil at mfc value with and without calcium hydroxide. the tested oil with calcium hydroxide revealed antifungal activity against c. albicans higher than that of the tested oil alone (larger inhibition zones diameters formation) and the statistical difference was highly significant (p ≤ 0.01) (table 4). table 4: comparison between the antifungal activity of oil extract with and without calcium hydroxide against candida albicans. inhibition zones against c. albicans without calcium hydroxide with calcium hydroxide ttest pvalue mean s.d. mean s.d. oil extract 12 0.816 15 2.108 -4.196 0.001* [*] highly significant discussion many studies in the literature reported the application of herbal extracts in endodontics. they have been used as disinfectants of root canals, intracanal medications, sealers for obturating canals and as solvents of gutta percha of previously treated teeth.(16) plants oil has been reported to have significant fungicidal effects related to its inherent constituents. (17) the results of this study revealed the antifungal activity of nasturtium officinale oil extract against c. albicans and this activity increased as the concentration increased. this finding is supported bya previous study that declared the direct relation of antimicrobial activities to the extract concentration.(18) it could be explained that the higher concentrations of the extract have higher contents of dissolved active constituents.(19) the presence of antimicrobial properties of watercress has been investigated and related to its inherent phytochemicals such as flavonoids and tannins. flavonoids are naturally occurring antimicrobials capable of inhibition of nucleic acid synthesis, cytoplasmic membrane function and energy metabolism.(20) tannins are able to inhibit microbial extracellular enzymes, deprive the substrates necessary for microbial growth and interrupt the active transport and electron flow.(21) several studies reported the antimicrobial activity of nasturtium officinale extracts against different pathogens. (22,23,24) the combination of oil extract with calcium hydroxide paste showed a positive reaction by demonstrating a larger inhibition zones of c. albicans than the inhibition zones formed by each individual agent with a highly significant difference (p ≤ 0.01). this finding suggests that a synergistic or additive effect could be achieved if a higher concentration of oil extract combined with calcium hydroxide paste. further ex-vivo studies are required to test the diffusion ability of the oil into dentinal tubules. conclusion watercress oil extract exhibited a worth noticed antifungal activity and it could be an effective herbal alternative to the available synthetic antimicrobials used in root canal treatment. conflicts of interest the authors have nothing to disclose. references 1. urban, k., donnermeyer, d., schäfer, e., et al. canal cleanliness using different irrigation activation systems: a sem evaluation. clin. oral investig. 2017; 21(9), 2681-2687. 2. prada, i., micó-muñoz, p., giner-lluesma, t., et al, a. influence of microbiology on endodontic failure. literature review. med oral patol oral cir bucal. 2019; 24(3), e364. 3. colaco, a.s. extreme resistance of enterococcus faecalis and its role in endodontic treatment failure, prog med sci. 2018;2,1. 4. ashraf, h., samiee, m., eslami, g., et al. presence of candida albicans in root canal system of teeth requiring endodontic retreatment with and without periapical lesions. iran. endod. j. 2007;2(1), 24. 5. tabassum, s, khan, fr. failure of endodontic treatment: the usual suspects. eur j dent. 2016;10:144-7. combination of oil extract with calcium hydroxide 15 2.108 8.1 0.738 9.769 0.000* j bagh college dentistry vol. 33(4), december 2021 evaluation of the antifungal 5 6. murray, pe., farber, rm., namerow, kn., et al. evaluation of morinda citrifolia as an endodontic irrigant. j. endod.. 2008; 34(1), 66-70. 7. athanassiadis, b., abbott, pv., walsh, lj. the use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodontics. aust. dent. j. 2007; 52, s64-s82. 8. gopikrishna, av., kandaswamy, d.j eyavel, rk. comparative evaluation of the antimicrobial efficacy of five endodontic root canal sealers against enterococcusfaecalis and candida albicans. j conserv dent. 2006;9:2–12. 9. persoon, if., buijs, mj., özok, ar., et al. the mycobiome of root canal infections is correlated to the bacteriome. clin. oral investig. 2017; 21(5), 1871-1881. 10. chaudhary, s., hisham, h., doha, m. a review on phytochemical and pharmacological potential of watercress plant. asian j. pharm. clin. res. 2018; 11.12: 102-107. 11. mahdavi, s., kheyrollahi, m., sheikhloei, h., et al. antibacterial and antioxidant activities of essential oil on food borne bacteria. open microbiol. j. 2019; 13(1). 12. fouad af. endodontic microbiology 1st edition: culture based analysis of endodontic infection by gunnar dohlen, p 40-65. wiley; 2009. 13. al-hyali, na. inhibition of bacterial growth around gutta percha cones by different antimicrobial solutions using antibiotic sensitivity test (an in vitro study). jbcd. 2013; 25(4), 26-32. 14. skucaite, n., peciuliene, v., vitkauskiene, a., et al. susceptibility of endodontic pathogens to antibiotics in patients with symptomatic apical periodontitis. j. endod. 2010; 36(10), 1611-1616. 15. al-mizrakchi, a. adherence of mutans streptococci on teeth surfaces: microbiological and biochemical studies. diss. phd thesis, 1998. 16. arora, s., saquib, sa., algarni, ya., et al. synergistic effect of plant extracts on endodontic pathogens isolated from teeth with root canal treatment failure: an in vitro study. antibiotics. 2021; 10(5), 552. 17. chouhan, s., sharma, k., guleria, s. antimicrobial activity of some essential oils—present status and future perspectives. medicines. 2017;4(3), 58. 18. bhalodia, nr., shukla, vj. antibacterial and antifungal activities from leaf extracts of cassia fistula l.: an ethnomedicinal plant. j. adv. pharm. technol. res. 2011; 2(2), 104. 19. weli, ta., mohammed, a. effect of ginger extract on mutans streptococci and candida albicans in comparison to chlorhexidine gluconate. j. baghdad coll. dent. 2013; 25(2), 179-184. 20. cushnie, tt., lamb, aj. antimicrobial activity of flavonoids. int. j. antimicrob. agents. 2005; 26(5), 343-356. 21. scalbert, a. antimicrobial properties of tannins. phytochemistry.1991; 30(12), 3875-3883. 22. nikan, j., khavari, h. in vitro anti-fungal activity of watercress (nasturtium officinale) extract against fusarium solani, the causal agent of potato dry rot. j. herb drugs. 2014;5(1): 19-24, 23. sadeghi, b. synthesis of silver nanoparticles using leaves aqueous extract of nasturtium officinale (no) and its antibacterial activity. int. j. med. microbiol. 2014; 4(2), 428-434. 24. khan, h., jan, sa., javed, m., et al. nutritional composition, antioxidant and antimicrobial activities of selected wild edible plants. j. food biochem. 2016; 40(1), 61-70. الخالصة زداد االهتمام بالمستخلصات العشبية كعوامل مضااد للميروبباات لاال السا وات الةليلاة الماياية الا العاا اللبا . رعتباو ال و ياو باات ا الخلفية: للفطوراات ليراه ال و ياو بمي ا مار هيدةبكسايد الرالسايوم ياد باعد ذب قيم طبية عظيماة. هاداله هاال الدةاإاة الاح التفةيال الا ال شااط المضااد المبيضات البيضاء كدباء دالل ق ا ال اة. العمل: تم عيل المبيضات البيض من المويح الارن رعا ون من ق ا ال اة المتعف ة أب الشل الا عاا ق اا ال ااة. تام تفدراد ساإاية بطوق المواد مختلفة من مساتخل زراه ال و ياو باإاتخدام طورةاة شاو اا ااة بالمةاة اة مار مع اون هيدةبكسايد الرالسايوم. تام المبيضات البيضاء لتوكييات اإااتخدام طورةااة اطباااق اال اااة لتفدرااد التوكيااي الةاتاال اخد ااح لليرااه المختب ااو يااد الفطورااات. تاام التباااة للااي المسااتخل اليرتاا لل و يااو ماار مع ون هيدةبكسيد الرالسيوم مر اليودبالوةم. هيدةبكسيد الرالسيوم بمةاة تها مر كماا ال تائج: أظهو مستخل اليرت شاطًا مضاًدا للفطورات يد المبيضات البيضاء ، بقد ب د أن هاا ال شاط رايداد مار زرااد توكياي المساتخل . و من قدة كل عامل تم التباةل علح د .أظهو الخلي المختبو للمستخل اليرت لل و يو مر هيدةبكسيد الرالسيوم قدة تثبيطية أكب مار االإت تا ات: ان المستخل اليرت لل و يو العال يد المبيضات البيضاء مما رشيو الاح امرا ياة اإاتخدام كادباء دالال الة اا ب ادل أب بخلطا هيدةبكسيد الرالسيوم. articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. raghdaa final.doc j bagh college dentistry vol. 26(2), june 2014 finite element ssup up restorative dentistry 30 finite element stress analysis study for stresses around mandibular implant retained overdenture mir-od raghdaa k. jassim, b.d.s., m.sc., ph.d. (1) ibrahim k. ibrahim, b.d.s., c.e.s., d.s.o. (2) abstract background: it has been well known that the success of mandibular implantretained overdenture heavily depends on initial stability, retention and long term osseointegration this is might be due to optimal stresses distribution in surrounding bones. types of mandibular implantretained overdenture anchorage system and number of dental implants play an important role in stresses distribution at the implant-bone interface. it is necessary to keep the stresses below the physiologic tolerance level of the bone .since. and it is difficult to measure these stresses around bone in vivo. in the present study, finite element analysis used to study the stresses distribution around dental implant supporting mandible implant retained overdenture materials and methods: eight models were constructed including four designs of anchorage system (ball-cup, ball-o ring, bar without distal extension and bar with distal extension).the first group of models were supported by four dental implant and second group of models were supported by two dental implant only. models constructed from the data obtained directly from patient the contour of bone was obtained from c.t scan image of patient, then data transferred to ansys program for modeling then load applied and solve the equation by the program, specified nodes were selected at the rings of crestal bone (cortical bone) and cortical cancellous interface around each dental implant and fixed for all models to monitor the stress change in that regions of different design of mirod.. after load application, specified nodes were selected at the rings of crestal bone (cortical bone) and cortical cancellous interface around each dental implant and fixed for all models to monitor the stress change in that regions of different design of mir-od . results: in the present study the stress distribution and maximum stresses value around dental implant had a relationship to the number of dental implant. , the result appeared that the maximum stresses and means of stresses value was lower in the first group of models (which was supported through the use four dental implant) than the second group of models (which was supported through the use of two dental implant only). for the first group of models the maximum stresses value around mesial implant was11.67, 10.51, 10.98 and 10.72 mpa, while the maximum stresses around distal implant was 21.33, 18.51, 18.86, and17.56 mpa for models 1,2,3 and 4respectively ,and the stresses around implant supporting second group of models was 22.52, 22.16, 20.51 and 19.60 mpa for models 5,6,7and8 respectively .statistical analyses of means value appeared that there was statistically significant difference in stresses means value around implant of the second group with that’s values around mesial and distal implant supporting first group of model . regarding the result of both ball and bar system, it has been demonstrated that stress was greater with ball attachment and mir-od supported by the use of four dental implants and anchored by bar attachments with distal extension gives the minimum values of stresses than the rest models. also the results show that higher stresses value was appeared at the cortical bone ring surrounding dental implant especially the distal implant nearest to the free end extension area. also it was appeared that the best model was mandible implant retained overdenture that’s anchored by bar with distal extension and support by four dental implant . conclusions: bar-clips with distal extension mode of attachment considered the best type in producing the least stresses around dental implant regardless number of dental implant used. key wards: implant, overdenture, stresses, bar, ball. (j bagh coll dentistry 2014; 26(2): 30-36). introduction the use of osseointegrated fixtures in dentistry has been demonstrated both histologically and clinically to be beneficial in providing long term oral rehabilitation in completely edentulous individual. the concept of implanting two to four fixtures in a bony ridge to retain a complete denture prosthesis appealing therefore, as retention, stability and acceptable economic compromise to the expanse incurred with the multiple fixture supported fixed prosthesis (1). mandibular implant-retained overdentures are generally anchored by at least two implants placed in canine or slightly medial to it (2-7). the most common forms of anchorage ball attachment (5) (1)assistant professor (ph.d. student during the research) department of prosthodontics. college of dentistry, university of baghdad. (2)retired professor. and two clips on bar connecting the implants (7). a tissue borne overdenture relies primarily on the residual alveolar ridge for support, the widely held assumption that the load is shared between implants and mucosa (5,6). biomechanical influence plays an important role in the longevity of bone around implant (8). forces on prosthesis e.g. during chewing will transfer to bone surrounding the implant so the long term of function of dental implant system will depend on the biomechanical interaction between bone and implant. several methods used to evaluate stresses around dental implant; one of the most important is the fea. this methods offer advantages of accurate representation of complex geometries easy model modification and representation of internal stresses and other mechanical quantification (9). beside that knowledge stresses distribution can provide j bagh college dentistry vol. 26(2), june 2014 finite element ssup up restorative dentistry 31 important information in the treatment planning phase of clinical case implant placement and by minimizing adverse loading and the number of clinical studies. , so fem can be considered as first step before clinical application. materials andmethods design of fea part of study the present study was design to study different eight models of mir-od which divided into two groups: in the first group, the first fourth models of mir-od supported by four dental implants, while in second group the rest fourth models supported by the use of two dental implants. also each group of model was attached with different mir-od attachments. modeling the most important point on which fea depends on was the accurate representation of model in order to get a realistic fea model, so that in this study the data obtained directly from patient according to the following steps : dimensions of bone model the model of mandibular bone has two parts the inner parts called the cancellous bone and the outer parts called the cortical bone. the whole dimensions of the mandibular bone were obtained directly from the patient depending from c.t scan image of patient (10-12). c.t scan radiograph image of mandibular bone was taking while the patient was wearing complete denture (13). the c.t scan radiograph images were scanned with negative scanner to be stored in a special folder in computer. this scanned mandible radiographic images of c.t scan radiography have not very well border to be outlined, to get the outer total volume of the mandible the images of each slice were processed in a manner as shown in figure. (1) and then a line drown at the outer border of each slice so that each slice transferred to ansys program, then the line between slices filled with area then with volume so the cortical bone volume of mandible was finished to give the total volume of mandible as shown in figure (1) on the following procedure: final volume of mandible bone the measurement of cortical bone from radiographic image showed that the cortical bone was 2 mm thickness (14, 15) so there was an order in ansys program to isolate 2 mm volume from the outer surface of mandible towered inside to have mandible bone with two volume outer volume cortical bones and the inner volume cancellousbone. the dimensions of final volume of mandibular bone were 25mm from the upper surface of mandible to the lower border of it; 2mm thickness of cortical bone and the thickness of cancellous bone 8mm as shown in figure (1). design and modeling of dental implant nobelpharm 60◦ thread dental implant was selected with 10 mm length and 4 mm width .the implant was used in this study taken from nobelpharm implant system. the geometrical shape of thread and final shape of dental implant (16) as shown in figure (2) with the ball super structure 2.25 mm diameter of ball attachment, cups attachment also modeled according to the measurements (17) shown in figure (2). modeling of mucosa all thickness of mucosa covering the cortical bone was 2 mm thickness except section of retro molar pad area 3 mm (18,19) as shown in figure (3).sectioning of the lower complete denture was done at the midline area in bucco-lingual direction and at the areas of canine – premolar, premolar – molar, molars-retro molar pad areas. dental vernia was used for measurement of sections of lower complete denture the measurement as follow: figure 1: ct radiographic image processed and final mandibular bone j bagh college dentistry vol. 26(2), june 2014 finite element ssup up restorative dentistry 32 figure 2: dental implant threads dimensions and design with titanium cup molar section from the tip of buccal cusp to the lower border of the buccal flange, tip of the lingual cusp to the lower border of lingual flange. boolean stage this stage includes collection of all parts of the model which include mandible bone, mucosa, dental implant, overdenture attachments, and complete denture. the first step of this stage was subtraction step; this was performed for mandible bone at the site 8 mm from midline for the placement of 1st implant and 2nd site 3mm from 1st implant for each half of mandible. subtraction was performed at the inner surface of complete denture at the site of retention cups. as shown in figure (3) mandible bone of cortical bone and cancellous bone b) mucosa c) dental implant d) overdenture of ball cup attachment as shown in figure (3). subtraction stage and site of dental implant with measurements glue relation applied for the relation between deferent parts of model. at the end of this stage the1stmodel was finished which compose of tooth with denture base buccally to the same point lingual. from these measurements the final geometrical shape of complete denture was modeled as shown in figure (3). complete denture section measurements and final geometrical shape of complete denture convexity buccal convexity at the buccal surface of tooth to the maximum convexity at the lingual side, from the point at the junction central fossa to the impression surface of lower complete denture, maximum buccal. complete fist model with ballcup attachments. for the next three model which include mir-od supported by four dental implant in mandible and different design of mir –od attachment so the changes would be in upper part of implant super structure and inner surface of mir-od. starting with 2nd model o-ring attachments used. in case of 3rd model bar – clip between dental implant was used (20). while in case of 4th model it had bar-clip with distal extension 3mm length. the second group of models has the same mode of attachments as the first group but the mir-od supported by two dental implants. defining of materials properties in most of fea studies the properties of all materials used were isotropic homogeneous and liner elastic (9,21). the properties of materials used in this study (dental implant, cortical bone, cancellouse bone. titanium, resin, mucosa. as shown in table (1). table 1: properties of materials material young's modulus mpa poissonُs ratio cortical bone 13.700 0.3 cancellouse bone 1.37 0.3 titanium 103.400 0.3 plastic rubber 0.01-0.1 0.37 resin 3.000 0.3 mucosa 1 0.39 j bagh college dentistry vol. 26(2), june 2014 finite element ssup up restorative dentistry 33 figure 3: mandibular with dental implant and complete denture models boundary condition the volume at the slice of the upper part of ramus was assumed to be fixed in axial anteriorposterior, medio –lateral directions to avoid the whole model from sinking when applying load to the implant while the reminder of the model was left free. meshing generations in order to obtain an accurate results fine mesh of the three dimensional element model will be generated as shown in figure (4) figure 4: half section of meshed model load application the load used in this study was 35 n directed axially down ward applied on a three position selected at the central surface of mir-od at three sites 1st area between premolar and first molar, 2nd at firstmolar central fossa and 3rd area at the area between first and second molar. solving of the equations the program now calculates the displacement and then the stresses at each node presenting .the software solve from one million and two thousand to nine hindered thousand equations for each model. the run time was about 7 hours. listing of the results based on von misses theory which state that failure occurs when evaluation stresses for the actual case is equal the yield strength of the material at selected nodes (22). specified nodes were selected at the rings of crestal bone (cortical bone) and cortical cancellouse interface around each dental .in vivo load on mir-od in two direction vertical and horizontal which either bucco -lingually or mesio distally appeared that the horizontal force are approximately 50% of the vertical forces is important to consider a combination of axial and horizontal load on the assumption that the implant and fixed for all models to monitor the stress change in that regions of different design of mir-od. the result for all nodes at each ring were huge so to be more specified the ring of bone represented as ring of 360° angle and the result selected at a node located at every 10° of angle. results most of the researchers’ results were listed the equivalent stresses in their result, since it represent the principle stresses around the dental implant. because of there were shear stresses generated around dental implant and this type of stresses very dangerous type of stresses and to have idea about the shear stresses generated around dental implant their distribution maximum values. in the present study octahedral shear stresses which represent the total equivalent shear stresses were listed. in table (2) the highest mean values of stresses is (12.215)mpa around distal implant of models in 1st group of models. also the highest mean values j bagh college dentistry vol. 26(2), june 2014 finite element ssup up restorative dentistry 34 around implant of 2nd group of models (14.35) as shown in table (3) . the behavior of stresses distribution around mesial and distal implant of the 1st group of models group of models during vertical load is highly significance differences as shown in table -4 .statistical analyses of means value appeared that there was statistically significant difference in stresses means value around implant of the second group with that’s values around mesial and distal implant supporting first group of models as shown in table 5 and 6. table 2: means and stresses values of stresses in bone ring surrounding mesial and distal implant of the first group of models during vertical load applications table 3: means and maximum values of stresses in bone ring surrounding implant of the second group of models during vertical load applications models 2nd implant shear stress at cortical/ cancellous ring stresses at cortical bone ring mean sd mean sd models 1 1.204 1.204 14.35 0.914 models 2 1.15 1.15 13.84 0.869 models 3 1.013 1.1008 13.11 0.885 models 4 0.9 0.903 12.14 0.813 table 4: paired t-test for the comparison of stresses around mesial and distal implant of the 1st group of models group of models during vertical load models mesial implant distal implant shear stresses at cortical cancellous bone ring equivalent stresses at cortical bone ring equivalent stresses at cortical bone ring shear stresses at cortical cancellous bone ring sig sig sig sig models 1&2 ns s s s models 1&3 s hs s hs models 1&4 hs hs s s models 2&3 s s ns hs models 2&4 hs hs ns s models 3&4 hs hs ns hs p<0.05 s, p>0.05ns, p<0.0001hs table 5: paired t-test for the comparison of stresses around mesial implant of the 1st group of models with that around implant of the second group of models during vertical load models 1st group mesial implant 1st group distal implant shear stress at cortical/cancellous ring stresses at cortical bone ring shear stress at cortical/cancellous ring stresses at cortical bone ring mean sd mean sd mean sd mean sd models 1 0.581 0.05 6.566 0.43 1.171 0.05 12.213 0.88 models 2 0.531 0.05 6.262 0.39 1.1429 0.05 11.724 0.78 models 3 0.463 0.04 5.870 0.41 1.068 0.06 10.93 0.81 models 4 0.475 0.04 5.700 0.40 0.966 0.06 9.922 0.70 models shear stresses at cortical cancellous bone ring equivalent stresses at cortical bone ring p value sig p value sig models 1&5 0.000 hs 0.000 hs models 2&6 0.000 hs 0.000 hs models 3&7 0.000 hs 0.000 hs models 4&8 0.000 hs 0.000 hs j bagh college dentistry vol. 26(2), june 2014 finite element ssup up restorative dentistry 35 table 6: paired t-test for the comparison of stresses around distal implant of the 1st group of models with that around implant of the second group of models during vertical load discussion in the present study the result appeared that the maximum stresses value and means of stresses around each dental implant supporting mir-od, regardless of the number of dental implant supporting mir-od different anchorage system. the stresses result was higher at cortical bone ring than that at cortical/cancellous bone ring. this result was in consistence with the results of clinical study which suggest that late failure take place after implant neck, where most of the stresses accumulate at the cortical bone area (23-25). statistical analyses of means value appeared that there was statistically significant difference in stresses means value around implant of the second group with that’s values around mesial and distal implant supporting first group of model .this means that the use of single implant in each side of dental arch offer what two dental implants offer. this means that increase number of dental implant supporting the mir-od add longer survival time for each dental implant. and the use of single implant in one side make the dental implant had less survival time especially if it was aggravated by other factors such as plaque accumulation at gingival area. this results was coinciding with blum and mccord and braka (26,27), they stated that the responsibility of posterior ridge and oral mucosa in providing retention, support and stability for mir-od were shift from the mucosa to dental implant as more dental implant are used. for the result of stresses distribution around dental implant supporting mir-od appeared that the distribution of maximum stresses value lies at the distal and mesial surface of two dental implants. references 1. stevens pi, fredrickson ej, gress ml, et al. implant prosthodontics clinical and laboratory procedures. 2nd ed. mosby; 2000. 2. engquist b, bergendal t, kallus t, linden u. a retrospective multicenter evaluation of osseointegrated implant supporting overdenture. int j oral maxillofac implant. 1988; 3:129-34. 3. zarb ga, et al. boucher’s prosthodontic treatment for edentulous patients. 11th ed. mosby year book. inc.; 1997. p. 262. 4. donatsky o. osseointegrated dental implants with ball attachments supporting overdentures in patients with mandibular alveolar ridge atrophy. int j oral maxillofac implant 1993; 8:162-6. 5. johns rb, jemt t, heath mr, hutton je, mckenna s, mc namara dc, van steenberghe d, taylor r,watson rm, herrman i. a multicenter study of overdentures supported by brånmark implants. int j oral maxillofac implant 1992; 7: 513-22. 6. jemt j, carlsson ge. aspects of mastication with bridges on osseointegrated implant. scand j dent res 1986; 94: 66-71. 7. tang l, lund jp, tache r, clokie cm, feine js. a within-subject comparison of mandibular long-bar and hybrid implant supported prostheses psychosomatric evaluation and patient preference. j dent res 1997; 1075-83. 8. shalak r. biomechanical considerations in osseointegrated prostheses. j prosthet dent 1983; 49: 843-8. 9. meijer hgj, starmans fj, steen wh, bosman f loading conditions of endoseous implants in an edentulous human mandible. a three-dimensional finite element study. j oral rehabil 1996; 23: 757-63. 10. nishigawa g, matsunaga t, marua y. okamoto m, natsaaki n, minage s finite element analysis of the effect of the bucco-lingual position of artificial posterior teeth under occlusal force on the denture supporting bone of the edentulous patient. j oral rehabil 2003; 30: 646-52. 11. heckmann sm, winter w, meyer m, weber h, wichmann mg. overdenture attachment selection and the loading of implant and denture bearing area part i: invivo verification of stereo lithographic model. clin oral impl res 2001; 12: 617-23. 12. heckmann sm, winter w, meyer m, weber h, wichmann mg. overdenture attachment selection and the loading of implant and denture bearing area part ii: a methodical study using five types of attachments. clin oral impl res 2001; 12: 640-7. 13. cranin an, klein m, simons: atlas of oral implantology. 2nd ed. london: mosby; 1999. 14. teixeira er, kagawa sy, shindio n. a comparative evaluation of mandibular finite element analysis models with different lengths and element for implant biomechanics. j oral rehabil 1998; 25: 299-303. 15. hung sc, tsai cf. finite element analysis of dental implant. j biomed eng appl basis comm 2003; 15: 82-5. 16. weinberg l. ct scan as radiological data base for optimum implants orientation. j prosthet dent 1993; 69: 381-5. 17. bassi f, carossa s, gassino g, meniccucci g, mozzati m, pera p, previgliono v, schierano g, preti models shear stresses at cortical cancellous bone ring equivalent stresses at cortical bone ring p value sig p value sig models 1&5 0.759 ns 0.008 s models 2&6 0.689 ns 0.001 s models 3&7 0.919 ns 0.003 s models 4&8 0.651 ns 0.000 s j bagh college dentistry vol. 26(2), june 2014 finite element ssup up restorative dentistry 36 g. advances in clinical prosthodontics. piccin nuova libararia s.p.a., padova; 1999. p. 167-215 18. takayama y, yamada t, araki t, kawasaki t. the dynamic behavior of a lower complete denture during unilateral loads: analysis using the finite element method. j oral rehabil 2001; 28: 1064-74. 19. kawasakin t, takayama y, yamada t, notanik k relationship between the stress distribution and the shape of alveolar residual ridge-three dimensional behavior of a lower complete denture. j oral rehabil 2000; 28(1): 950-7. 20. mericske – stern r, burginw bh, geering ah. three dimensional force measurements on mandibular implants supporting overdentures. int j oral maxillofac implant 1992; 7:185-94. 21. van zyl p, grundling n, jooste ch, terblanche e. three-dimensional finite element model incorporating six osseointegrated implants for stress analysis of mandibular cantilever prostheses. int j oral maxillofac implant 1995; 10: 595-603. 22. o’mahony a, boweles q, woolsey g, robinson sj, spencer p. stress distribution in the single unit osseointegrated dental implant: finite element analysis of axial and off-axial loading. j implant dent 2000; 3(9): 207-16. 23. himmlova l, dostalova, kacovsky a, konickova s. the influence of implant length and diameter on stress distribution a finite element analysis. j prosthet dent 2004; 91: 20-5. 24. siegele d, soltsz u. numerical investigations of the influence of implant shape on stress distribution in jaw bone. int j oral maxillofac implant 1989; 4(4): 33340. 25. kitamura e, stegaroia r, nomura s, miyakawa o. biomechanical aspects of marginal bone resorption around osseointegrated implants. consideration based on a three dimensional finite element analysis .clin oral impl res 2004; 15: 401-12 26. mccord jf, grant aa. specific clinical problem areas. brit dent j 2000; 26: 186-93. 27. braka oa, mohamed ia. clinical, radiographic and electromyography evaluation of lingualized occlusion versus monoplane occlusion in implant supported overdenture. offeci j egyp dent asso 2000; 86(2): 401. j bagh college dentistry vol. 33(2), june 2021 the influence of different 21 the influence of different root canal irrigants on the pushout bond strength of ah plus and bioceramic sealers alaa mohammed naeem (1), iman mohammed al-zaka (2) https://doi.org/10.26477/jbcd.v33i2.2935 abstract background: the bond strength of endodontic sealers with dentin is a very important property for maintaining the integrity and seal of the root canal filling. the aim of this study was to evaluate and compare the effect of various irrigants (qmix, 17% edta and 2.5% naocl) on the push-out bond strength of ah plus and bioceramic sealers. materials and methods: forty eight freshly extracted maxillary first molars human teeth with striaght palatal root were used in the study. the collected samples were randomly divided into three groups of equal sample size (n=16), according to the final irrigation regimen as follows: group (1): qmix 2 in 1, group (2): 17% ethylenediaminetetraacetic acid, group (3): 2.5% sodium hypochloride. all samples were instrumented using edge file x7 rotary instrument reaching file size 40/.04 as the final master apical file. after that each group was randomly divided into two subgroups (n=8) according to the type of sealer used: ah plus and total fill bc sealer. obturation was conducted using single cone technique with gutta percha (gp) to all experimental roots. two-millimeter thick slices were obtained from the middle section of the root. bond strength of sealers was measured via a universal testing machine by using stainless steel plunger. then, the data were statistically evaluated using two-way analysis of variance (anova) and post hoc test (bonferroni’s test). results: the push-out bond strength was significantly increased by the “irrigant” factor (p≤0.05) and by “sealer/irrigation solution” interaction (p≤0.05). final rinse with qmix solution with bc sealer showed the highest mean value of bond strength (5.976 mpa), with a significant difference with other groups (p≤0.05), while naocl with ah plus sealer showed the lowest mean value of bond strength (3.811 mpa). conclusion: final irrigation of the root canals with different irrigants improved the endodontic sealer's bond strength, and qmix had a positive influence on the adhesion of bc sealer. keywords: ah plus, bioceramic sealer, qmix, push-out bond strength, irrigant. (received: 18/11/2020, accepted: 15/12/2020) introduction endodontic therapy aims to promote disinfection of root canal, prevent microorganisms from impairing periapical healing or even lead to the development of apical lesions.(1) it has numerous clinical steps which include not only effecient mechanical root canal instrumentation, but also irrigation with adequate disinfecting solutions for dissolving of organic and inorganic material, producing a debris free surface, and achieving a three dimensionally sealed and obturated root canal by using an ideal sealer along with guttapercha.(2,3) generally, the root canals are shaped with hand instruments or rotary systems under a constant irrigation.(4) in a study of micro-ct images collected before and after shaping of the root canal, 35% or more of the root canal wall (including the isthmus) was observed to be unchanged, in any manner of the canal preparation technique. for that reason, the significance of irrigation and the complete disinfection of root canals has been verified.(5) (1) master student, conservative department , college of dentistry, mustansiriyah university, baghdad, iraq. (2) professor, conservative department, college of dentistry, mustansiriyah university, baghdad, iraq. corresponding email, alaanaeem7393@gmail.com in addition, irrigation solutions should be assist in removal of the smear layer. the smear layer is an iatrogenic layer, generated on dentinal surfaces, primarily consist of inorganic particles of calcified tissue and organic material including bacteria, blood cells, necrotic tissue, pulp tissue and odontoblastic processes.(2,3,6) therefore, removal of this layer is an essential step, as its presence prevents the penetration of root canal materials to root canal surfaces. sodium hypochlorite (naocl) is the most widely used irrigating solution, because of its an antibacterial activity and the capacity to rapidly dissolve necrotic tissue, vital tissue of the pulp, and the organic debries of dentin and biofilms. so, due to to its capacity against pathogenic organisms and pulp tissue debries, and fulfills a lot of the favorable properties that previously reported, it is considered as the irrigant of choice in endodontics.(7) however, since of it’s inability to remove inorganic materials and dissolve the smear layer, adjunctive use of an acid or chelating agent with such properties is recommended. for complete cleaning of the root canal surfaces, it is essential to use a combination of organic and inorganic tissue dissolving agents.(8) the smear layer's removal power by edta chelating agent, makes it one of the most https://doi.org/10.26477/jbcd.v33i2.2935 mailto:alaanaeem7393@gmail.com j bagh college dentistry vol. 33(2), june 2021 the influence of different 22 commonly used in the irrigation of root canal. therefore, it is usually used in the comparative research studies that comparing the efficacy of various irrigation solutions, as the gold standard for the removal of smear layer.(9) qmix, another irrigants which used to dissolve the smear layer and debris from the root canal surfaces, consisting of a chx analog, edta as a decalcifying agent and surfactant, it is also appeared as antimicrobial irrigant.(10) effective endodontic treatment depends on the complete obturation of the complex root canal system with root canal filling materials that are dimensionally inert, stable and biologically compatible.(11) due to their wettability of dentin and gutta-percha and appropriate physical properties, low solubility, dimensional stability, adequate microretention to dentin and biological performance, epoxy resin-based sealers such as ah plus (dentsply, usa) have been widely used in endodontic treatment.(3) the use of bioceramic material as root canal sealer has been established.(12) total fill bc sealer (fkg, switzerland) is an premixed, injectable, zero shrinkage, insoluble, radiopaque, and hydrophilic, means that it uses the moisture in the dentinal tubules to initiate and complete its setting reaction.(12) the influence of endodontic irrigants on bond strength of various types of root canal sealers has been investigated in several studies. there is minimal evidence concerning the effects of qmix irrigation solution on the bond strength of root canal sealer. therefore, the goal of this study is to evaluate and compare the effect of various irrigants (qmix, 17% edta and 2.5% naocl) on the push-out bond strength of both ah plus and bioceramic sealers. the null hypothesis states that when using different irrigants, there is no difference in the bond strength of epoxy resin and bc sealers. materials and methods sample selection forty eight freshly extracted maxillary first molars human teeth were used in the study. soft periodental tissues on the teeth surfaces were removed immediately after the extraction manually by using a cumine, and then disinfected with 2.5 % naocl solution for 30 minutes.(13,14) one of the most common and efficiently used methods for sterilization and disinfection of extracted human teeth before in vitro work is by naocl.(14,15) the concentration used in this study (2.5% naocl) is within the acceptable concentrations(14) with a minimal possible effect on dentin, while the concentration used in other studies reached up to 5.25% with a longer exposure time and this could affect the dentin properties.(15) after that all disinfected samples were washed with tap water, and eventually stored in normal saline until used. the criteria for root selection were striaght palatal root, mature and centrally located apical foramen, patent apical foramen and devoid of any resorption, crack or fracture have been used in the study. sample preparation to ensure standardization, the length of palatal root was determined by digital calliper and marker to 11 mm from the end of the root, after that by using diamond disc (komet, germany) in a straight handpiece with water coolant, the palatal root was sectioned. a size 15 k file (dentsply maillefer, switzerland) was placed in the canal until it visible at the apical foramen, to ensure that the canal was patent. the working length was confirmed by subtracting 1mm from this measurement which is 10 mm. the specimens were then randomly divided into three groups (n=16) according to the final irrigation regimen as following: group 1: 5ml qmix 2in1 (dentsply tulsa dental, tulsa, ok) for 60 second. group 2: 5 ml of 17% edta solution (pd, switzerland) for 60 seconds. group 3: 5ml of 2.5% naocl solution (promida, turkiye) for 60 seconds. biomechanical preparation was performed with rotary edgefile x7 instruments (edgeendo, usa) according to the manufacturer's instruction using an electric speed and torque controlled endodontic motor (nsk, japan), with the speed set to 300 rpm and a torque of 3.0 ncm. the instrumentation was completed in crown down manner to size 40/.04 as a maf. the canal was irrigated with 1.0 ml of 2.5% naocl via a sterile 30-gauge side vented needle which penetrated 2mm short of the working length. for standardization purpose, one set of the instrument was used to prepare three canals and then discarded. final irrigant was allowed to remain in the canal for 1 minute. after that all groups were received a (5 ml) of saline as a final flush and then dried with absorbent paper points. after that, each group was randomly divided into 2 subgroups, according to the sealer type that was used to obturate root canal (n=8): subgroup (a): the root canals were obturated using ah plus sealer (dentsply detrey gmbh, germany). j bagh college dentistry vol. 33(2), june 2021 the influence of different 23 subgroup (b): the root canals were obturated using total fill sealer (fkg dentaire, switzerland). the sealer was mixed according to the manufacturer’s instructions. obturation was done by single cone technique with gutta percha (komet, germany). all the samples were radiographed at 2 angulations (mesiodistal and buccolingual) by x-ray device (my ray, italy) to confirm the quality of obturation. then, the coronal accesses of the root canals were sealed with temporary filling material. the samples were stored in an incubator at 37°c and 100% humidity for 7 days to ensure complete setting of the test materials.(16) after the storage period, the roots were embedded in clear acrylic resin, after complete curing of the acrylic mold, and by using handpiece fixed in a custom made fixing device, a 2 mm thick slice of mid-root dentin was made at 4.5-6.5 mm from anatomical apex. the cut was made horizontally with flow of cold water to minimize smearing. the thickness of each slice was checked with the aid of digital caliper and examined for any type of deformities. then, to make sure that the load will be applied in apicocoronal direction, each slice was marked on its apical side as shown in figure (1). push-out bond strength test push-out test was carried out by applying a compressive load to the apical aspect of each slice by using a cylindrical plunger mounted on a computer software-managed universal testing machine (instron machine, laryee, wdw-50, china). by using stainless steel plunger, which provided the most extensive fig ure 1 : slice of mid-root dentin embedded in clear acrylic resin. coverage over the filling material without touching the canal wall, the push out test was performed. the size of the punch pin that was used 0.5 mm in diameter. loading was performed at a speed of 1 mm/min by a universal testing machine in an apicocoronal direction until the first dislodgment of obturating material and a sudden drop along the load deflection as shown in figure (2). the force was recorded by using data analysis software. the maximum failure load was registered in newtons, and push-out bond strength was measured in megapascals (mpa) from force (n) divided by area (mm) of the bonded interface.(17) the area under load was measured by ½ * (circumference of coronal aspect + circumference of apical aspect) *thickness.(17,18) by using image j software analysis program, the circumference measurements were calculated. figure 2: push-out test process. the mode of bond failure after push-out test was observed under light microscope (st 60 series, china). the failures were classified as type i (adhesive failure, no residual material on the canal wall), type ii (cohesive failure, material exist on entire canal wall), or type iii (mixed failure, material present as patches on canal wall).(19) the data were statistically evaluated using two-way analysis of variance (anova) and post hoc test (bonferroni’s test). the selected level of significance was set at a p value<0.05. analysis was performed on ibm spss, ver. 25 software (ibm, new york, usa). results the normality of data in the present study was tested using shapiro–wilk test and was found to be normally distributed (p > 0.05). the results of mean values, minimum (min.), maximum (max.) and standard deviations (sd) of push-out bond strength in the middle third of root canals for two types of sealers are shown in table (1). two-way j bagh college dentistry vol. 33(2), june 2021 the influence of different 24 anova indicated that the push-out bond strength was significantly improved by the “irrigant” factor (p ≤ 0.05) and by “sealer/irrigation solution” interaction (p ≤ 0.05), but there was no significant difference in sealer factor table (2). regarding the push out bond strength of ah plus sealer, the bonferroni test showed no significant difference among subgroups (1a, 2a and 3a). regarding of bc sealer, groups 1b showed higher mean values than group 2b and 3b, and there was significant difference in push-out bond strength between subgroups (1b&2b) and (1b&3b) (p ≤ 0.05), as shown in (table 3). the predominant mode of failure in ah-plus group was mixed failure (both adhesive and cohesive failure), while cohesive failure was the most frequent type in bc group. table 1: descriptive statistics of push-out bond strength (mpa) for all groups. table 2: two way anova test between-subjects affect the bond strength. source type iii sum of squares df mean square f p-value sig. irrigant 16.482 2 8.241 5.700 0.006 s** sealer 0.239 1 0.239 0.165 0.686 ns* irrigant*sealer 10.650 2 5.325 3.653 0.034 s** error 60.724 42 1.446 total 1112.497 48 corrected total 88.095 47 p > 0.05: non significant (ns)* p ≤ 0.05: significant (s)** groups subgroups n. mean ±sd min. max. subgroup 1a 8 4.705 0.986 3.388 6. (qmix&ah) group 1 qmix subgroup 1b 8 5.976 1.214 4.518 7.906 (qmix&bc) subgroup 2a 8 5.129 1.810 2.259 7.153 (edta&ah) group 2 edta subgroup 2b 8 4.094 1.214 2.259 6.400 (edta&bc) subgroup 3a 8 3.811 0.840 2.635 5.271 (naocl&ah) group 3 naocl subgroup 3b 8 4.000 0.875 2.635 5.271 (naocl&bc) j bagh college dentistry vol. 33(2), june 2021 the influence of different 25 table 3: statistical test of the effect of irrigants*sealers interaction on the push-out bond strength with pairwise comparisons using bonferroni test sealers irrigants mean std. error p-value sig. difference qmix*edta 0.424 0.601 1.000 n.s.* (1a*2a) subgroup a qmix*naocl 0.894 0.601 0.433 n.s.* (ah plus) (1a*3a) edta*naocl 1.318 0.601 0.102 n.s.* (2a*3a) qmix*edta 1.882 0.601 0.010 s.** (1b*2b) subgroup b qmix*naocl 1.977 0.601 0.006 s.** (bc sealer) (1b*3b) edta*naocl 0.094 0.601 1.000 n.s.* (2b*3b) p > 0.05: non significant (ns)* p ≤ 0.05: significant (s)** discussion adhesion of endodontic sealers to root canal dentin resist filling dislocation either by frictional retention or micromechanical adhesion and maintains the integrity of sealerdentin interface.(20) the push-out bond test was used because is reproducible and can be interpreted easily. with the advantage that it enables root canal sealers to be tested even with low bond strength, and it is more effective.(21) the push-out test method for bond strength testing generates fractures parallel to the dentinsealer interface(22,23), thereby producing more clinically accurate and effective results that better represent a sealer's bond strength. the greater the bond strength of an endodontic sealant to radicular dentin, the greater the integrity of sealer-dentin interface.(24) in this study, 2 mm thick segment was used, in order to prevent premature debonding and was only taken from the middle portion of the roots, because these areas usually have more favorable conditions for adhesion of root canal sealers than the apical portion, also since the radicular dentin is not uniform and its tubular density decreases from coronal to apical region. in addition, during the chemomechanical preparation, the prepared wall surface of root canal can differ widely.(16,20,25) due to its superior properties, such as dimensional stability, low solubility, better wettability of dentin and gutta-percha and good sealing ability, the epoxy resin-based ah plus sealer was selected as a reference for comparison in the present study and dealt with as a gold standard.(3,26,27) regarding obturation techniques, the single cone obturation technique was used in this study with ah plus and bioceramic sealers by using matching gutta-percha cones, due to the introduction of new rotary files with different and variable tapering, gutta-percha cones manufactured to have the same tip size and taper as the corresponding rotary systems. also the single cone obturation technique, that was used in this study with ah plus and bioceramic sealers, was in accordance with previous studies.(28,29) under the condition of this study the final rinse with qmix root canal irrigant showed the highest mean of push-out bond strength. this result could be explained by the presence of surfactant in the qmix solution. surfactants decrease surface tension and improve wettability, thereby enhancing the flow rate of the irrigating solution, effectively removing the smear layer and increasing the root canal sealer's ability to penetrate the dentinal tubules.(30,31) also, assis et al., found that chx in the qmix solution increases the free surface energy of dentin and reduce the contact angle of endodontic sealers.(32) the result of this study, that found the final rinse j bagh college dentistry vol. 33(2), june 2021 the influence of different 26 of the root canal with qmix solution showed the highest mean of push-out bond strength, was in agreement with the finding of gündoğar et al.(33) when comparing the mean value of push-out bond strength of the qmix with edta group, there was no significant difference between them. these results in agreement with (leal et al. ; bayram et al. ; keerthana et al.).(16,34,35) previous researches concerning the effectiveness of smear layer removal, that using protocols of naocl during preparation and as a final rinse edta or qmix, found similar smear layer and debris removal capacities. therefore, indicating the same extension of sealer penetration into the dentinal tubules, so justifying the similar findings of push-out bond strength of the current study.(28,36,37,38) however, other studies concluded that qmix was better than 17% edta.(33,39,40) the lowest mean of push-out bond strength was found in naocl group, and there was a highly significant difference shown between qmix group and naocl group. this may be attributed to the nature of naocl root canal irrigant, which can only remove the organic portion of the smear layer and cannot dissolve the inorganic materials.(37) this results agree with (banode et al. ; keerthana et al. ; gündoğar et al.), they concluded that due to naocl was used as irrigation solution, the lowest mean value of smear layer removal and bond strength was gained. (33,35,41) for ah plus sealer, this study showed that there was no significant difference in the push out bond strength of ah plus sealer after using different irrigation solutions (qmix, 17% edta, naocl). obviously, ah plus has high dislodgement resistance and the use of chelating solutions, and naocl has a positive effect on ah plus' push-out bond strength. so due to the removal of the smear layer and debris by using irrigation solutions that lead to complete exposure of the amino groups of the dentinal collagen, therefore, this may increase the number of covalent bonds between the epoxy resin and amino groups, resulting in a stronger bond of ah plus to root canal dentin. this result in agreement with the results of other studies.(16,19,28,34,42,43) regarding the bc sealer, after using different irrigation solutions (qmix, 17% edta, naocl), this study showed that the removal of the smear layer by using qmix solution as a final rinse improved the bond strength of bc sealer compared to other irrigation solutions. two reasons could be attributed to the bond strength of the sealer, firstly: smear layer removal procedures by qmix solution allow the penetration of sealer into the dentinal tubules and this may increase the dentin bond strength of sealer as well as an improved seal, secondly: the suggested mechanism of the sealer's bonding. thus, because of the hydroxyapatite which represent the main component of dentin, and has a hydroxyl group, and due to the setting reaction of the total fill bc sealer, which is bioceramicbased sealer, that begins by absorbing water from the dentinal tubules, and after this reaction, calcium silicate hydrogel and hydroxyapatite compound are formed. the calcium silicate hydrogel chemically binds to the hydroxyapatite through the hydroxyl groups and this follows a continuous crystal growth process, producing a strong chemical bond with the dentin. additionally, during the setting reaction of bioceramic-based sealers, these sealers are able to flow through dentinal tubules without any shrinkage.(12,44,45) the bond strength of bc sealer in group (ii), that using edta solution as a final rinse, was lowest as compared to group (i) that using qmix solution as a final rinse, this may be due to effect of edta on apatite that formed during setting reaction of the sealer. lee et al., studied adverse effects of edta on hydration and micro hardness of mta and found that after chemomechanical preparation, the residual edta left behind in root canal dentin continue to chelate calcium ions released from mta during hydration, thus interfering with the hydrated products precipitation.(46) also govindaraju et al., demonstrated that the compressive strength of tricalcium silicate cements was decreased by using edta as irrigation solution to remove the debris.(47) this result in agreement with the results of other studies who stated that after final irrigation of the root canals with qmix solution and as compared with edta and naocl solutions, the bond strength of bc sealer was improved.(33) however, this result disagree with bayram et al., who found that there was a similar effects of qmix and 17%edta on the bond strength of bc root canal sealer.(16) this disagreement may be related to evaluated the adhesion resistance of sealers in the absence of gutta-percha and the methods that used for the irrigation in their study. the predominant mode of failure for ah plus group was mixed failure (both adhesive and cohesive failure), this finding is in agreement with (aranda‐garcia et al. ; leal et al.) that they observed the predominant failure mode of ah plus sealer was mixed failure.(28,34) while, the j bagh college dentistry vol. 33(2), june 2021 the influence of different 27 predominant mode of failure for bc group was cohesive failure, this finding is in agreement with (shokouhinejad et al. ; bayram et al.) that they revealed the mode of failure for bc sealer was mainly cohesive.(16,43) this result could be attributed to bioactivity of bc sealer, since bc sealers bond to root dentin and allows ions exchange where the minerals of bc sealer permeate the dentin,(48) and make a mineral infiltration zone at the sealer-dentin interface that may result in lower gap formation compared to ah plus sealer.(49,50,51) also, han & okiji stated that inside the dentinal tubules, bc sealer forms a tag-like structure that may be responsible for the sealing capacity and dentin bonding of the sealer.(52) one of the limitations of this study was that it assessed only the bond strength of resin based and bioceramic based sealers under influence of different irrigation protocols, and adhesion is only one property of the endodontic sealer quality. there is another property for future studies such as studying the effect of different irrigation protocols on the penetration depth of different sealers. conclusion within the limitations of this sutdy, it can be concluded that the irrigation solution type plays an important role in the adhesion of endodontic sealers. irrigation with qmix compared with edta and naocl irrigation solutions as a final irrigant produces a higher push-out bond strength of bc sealer to radicular dentin, while qmix, edta and naocl showed no significant difference on the push-out bond strength of ah plus sealer to radicular dentin. conflict of interest: none. financial disclosure this research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. references 1. nair p. on the causes of persistent apical periodontitis: a review. int endod j.2006;39:249-81. 2. razmi h, bolhari b, dashti nk, fazlyab m. the effect of canal dryness on bond strength of bioceramic and epoxyresin sealers after irrigation with sodium hypochlorite or chlorhexidine. iran endod j. 2016;11(2):129-33. 3. verma d, taneja s, kumari m. efficacy of different irrigation regimes on the push-out bond strength of various resin-based sealers at different 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polyalkenoates. j dent res. 2012;91:454-59. 50. camilleri j. will bioceramics be the future root canal filling materials? curr oral health rep. 2017;4:228-38. j bagh college dentistry vol. 33(2), june 2021 the influence of different 29 articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. 51. eltair m, pitchika v, hickel r, kuhnisch j, diegritz c. evaluation of the interface between gutta-percha and two types of sealers using scanning electron microscopy (sem). clin oral investig. 2018;22:1631-39. 52. han l, okiji t. bioactivity evaluation of three calcium silicate-based endodontic materials. int endod j. 2014;46:808-14. المستخلص: تعتبر قوة الترابط بين معاجين الحشو اللبية مع العاج خاصية مهمة للغاية.كان الهدف من هذه الدراسة هو تقييم ومقارنة تأثير : الخلفية أنوا )مختلف الري االقنية naocl٪ 2.5و qmix ،17٪ edtaع حشو لمعاجين للخارج واالنفصال االرتباط قوة على ) . (bioceramicو ah plusالجذرية التالية ) حنكي : العمل والطرق المواد جذر مع حديثًا مستخرج العلوي للفك اولي طاحن بشري سن وأربعون ثمانية الدراسة في استخدمت كل في جذرا عشر )ستة العينة حجم في متساوية مجموعات ثالث إلى عشوائي بشكل جمعها تم التي العينات تقسيم تم مستقيم. ائي على النحو التالي: مجموعة( ، وفقًا لنظام الري النه ،qmixالمجموعة االولى: ري نهائي بمحلول ٪، 17بتركيز edta: ري نهائي بمحلول الثانيةالمجموعة .٪ 2.5 وبتركيز الصوديوم هايبوكلوراتالمجموعة الثالثة: ري نهائي بمحلول ( باستخدام أداة تجهيز جميع العينات تصل إلى حجم edge file x7)تم تقسيم كل مجموعة 0,04/ 40الدوارة التي تم بعد ذلك . و ah plus)بشكل عشوائي إلى مجموعتين فرعيتين )ثمانية جذور في كل مجموعة فرعية( ، وفقًا لنوع معجون الحشو المستخدم: (total fill bcباستخدام الفردي المخروط تقنية باستخدام الجذرية القناة سد تم .gutta perch) تم التجريبية. الجذور لجميع ) مم من القسم األوسط من الجذر. تم قياس قوة االرتباط لماجين الحشو عبر آلة اختبار عالمية باستخدام 2الحصول على شرائح بسمك االت ثنائي التباين تحليل باستخدام إحصائيًا البيانات تقييم تم ذلك ، بعد للصدأ. المقاوم الفوالذ )مكبس من واالختبار anovaجاه ) (. bonferroniالالحق )اختبار "الري :النتائج بعامل معنويا االرتباط قوة تأثر النتائج النهائي اظهرت الري أظهر الري". محلول / الحشو "معجون والتفاعل " الحشو (qmix)بمحلول معجون متوسط bioceramic)باستخدام أعلى المجموعات ( مع معنوي فرق وجود مع ، ارتباط قوة قوة الرابطة. ( أقل متوسط (ah plusو باستخدام معجون الحشو مالصوديو كلوراتهايبواألخرى. بينما أظهر الري النهائي بمحلول نستنتج من ذلك ان الري النهائي لقنوات الجذر بأستخدام مواد الري المختلفة يؤثر على قوة ارتباط معاجين حشو االقنية االستنتاجات: . bioceramic)اط معجون الحشو ) ( تأثير إيجابي على قوة ارتب qmixالجذرية ، وكان لمحلول الري ) mustafa.doc j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 71 evaluation of shear bond strength of artificial teeth to heat cure acrylic and high impact heat cure acrylic using autoclave processing method mustafa m.j., b.d.s., m.sc. (1) abstract background: debonding and fracture of artificial teeth from denture bases are common clinical problem, bonding of artificial teeth to heat cure acrylic and high impact heat cure acrylic denture base materials with autoclave processing method is not well known. the aim of this study was to evaluate the effect of autoclave processing method on shear bond of artificial teeth to heat cure denture base material and high impact heat cure denture base material. materials and methods: heat polymerized (vertex) and high impact acrylic (vertex) acrylic resins were used. teeth were processed to each of the denture base materials after the application of different surface treatments. the sample (which consist of artificial tooth attached to the denture base at 45 degree) are consist of (80) artificial teeth from the same model of central incisor, they were prepared , treated and bonded to the conventional heat cured and high impact acrylic denture base material then processed. control group (group a 40 samples) in which acrylic resins pmma cured by conventional waterbath processing technique (74°c for 1.5 hours then boil for 30 minutes),the group was subdivided to 20 samples heat cure acrylic and 20 samples high impact acrylic. experimentalgroups (group b 40 samples) in which acrylic resins was cured by autoclave at 121°c, 210kpa. for 30min.the group subdivided to 20 samples heat cure acrylic and 20 samples high impact acrylic. for each subgroup, the 20 samples were subdivided according to surface treatment into: 1-five acrylic teeth without any surface treatment (control). 2five acrylic teeth with diatoric preparation (retention grooves). 3five acrylic teeth conditioned with thinner. 4five acrylic teeth with retention grooves and thinner. results: statistical analysis revealed that chemical and mechanical treatment of acrylic teeth improved the shear bond with heat cure and high impact acrylicalsoautoclave processing improvedthe shear bond with acrylic teeth in high impact acrylic. conclusion: autoclave polymerization is suggested as alternative method for processing denture base resins. autoclave polymerization can be easily performed in laboratory conditions. in high impact acrylic, there were highly significant differences of autoclave processing technique compared with water bath regarding the shear bond strength with acrylic teeth. key words: high impact acrylic resin, autoclave polymerization, artificial teeth, deboning. (j bagh coll dentistry 2014; 26(4):71-77). الخالصة ناعیة وقاعدة الطقم بطریقة تسخین االكریلیك وكسر األسنان االصطناعیة من قواعد أسنان ھي من مشاكل الطقم الشائعة، الترابط بین األسنان االصط خلع:الخلفیة ن االصطناعیة مع مع طریقة معالجة األوتوكالف لیست معروفة جیدا، وكان الھدف من ھذه الدراسة تقییم تأثیر طریقة معالجة األوتوكالف على ارتباط االسنا .قاعدة طقم االسنان رلك المقاوم للصدمات كمادة لقاعدة الطقم وتم لصق االسنان لكل نوع من انواع االكرلك بعد المعالجة تم استعمال االكریلك الحراري واالك:المواد و االسالیب واع قاعدة الطقم السطحیة تتكون العینات من ثمانین عینة نفس النوع والطراز من السن القاطع االمامي العلوي تم تحضیر االسنان ومعالجتھا لكل نوع من ان ون من اربعین عینة مرتبطة باالكرلك الحراري مطبوخة بطریقة البلمرة المائیة ومقسمة الى عشرین عینة مطبوخة بطریقة البلمرة المجموعة الرئیسیة تتك, عینة مقاوم للصدمات 20عینة اكرلك حراري و 20دقیقة ھذه المجموعة مقسمة الى 30ساعة وبعد ذلك غلیان لمدة ) 1.5(درجة سلیزیة لمدة) 74(المائیة .جموعة المختبریة تتكون من اربعین عینة مرتبطة باالكرلك الحراري ومبلمرة بطریقة االوتوكلیف وبنفس التقسیمات بالمجموعة االولى الم. :قسمت العینات تبعًا لطریقة المعاملة السطحیة على .خمسة عینات بدون معاملة سطحیة -1 . خمسة عینات معاملة میكانیكیة بطریقة االخادید السطحیة -2 .خمسة عینات معاملة كیمیائیة بمادة الثنر -3 .خمسة عینات معاملة میكانیكیًا وكیمیائیًا -4 رھا الطریقة البدیلة بطریقة البلمرة المائیة او الطبخ المائي وفي االكرلك بامع محدودیة البحث یستنتج بأن طریقة االوتوكلیف للبلمرة من الممكن اعت:االستنتاج ان ظ وجود زیادة واضحة احصائیًا لطریقة االوتوكلیف مقارنتًا بطریقة البلمرة بالطبخ المائي في ما یخص االرتباط القصي السطحي مع االسنالمقاوم للصدمات لوح .الصناعیة introduction poly (methyl methacrylate) (pmma) or heat cured acrylic is the most commonly used material in construction of denture base since 1936 (1). this material is not ideal for using in every case, and it (1)assistant lecturer. department of prosthodontics, college of dentistry, university of baghdad is a combination of different rather than one single desirable property that account for its wide usage. despite its popularity in satisfying aesthetic, simple processing and easy repair, it is still far from ideal in fulfilling the mechanical requirements of prosthesis (2). the vast majority of dentures made today are fabricated from heat cured poly (methyl methacrylate) and rubberj bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 72 reinforced poly (methyl methacrylate) (3). highimpact strength acrylics employ a pmma polymer modified by adding a rubber compound to improve strength properties (4). over the years, curing procedures have been modified with a view to improve the physical and mechanical properties of resin materials. different polymerization methods have used: heat, light, chemical and microwave energy (5,6). indian researchers investigated the pressure cooker polymerization technique; conventional pmma material can be used for this technique and requires less than 1h for polymerization and used conventional equipment used for heat cure processing. previous studies of pressure cooker polymerization showed comparable physical and mechanical properties to the water bath technique (7). the failure rate of acrylic resin dentures due to fractures have been reported to be an acceptably high and the most common type of failure encountered was de-bonding fracture of the teeth (5,8). previous researches have indicated that chemical or mechanical preparations or modifications of the denture teeth surface of artificial teeth prior to bonding improved bond strength (9,10). there is no previous iraqi study that investigated the effect of autoclave processing or curing method on shear bond of artificial teeth to different types of heat cure denture base material. therefore, the aim of this study was to investigate the effect of autoclave processing method on shear bond of artificial teeth to heat cure denture base material and high impact heat cure denture base material. materials and methods materials table 1 showed some of the materials used in this research table 1. some of materials that were used in this study materials manufacturer 1. heat cured acrylic resin (powder and liquid vertex,holland 2. heat-curing, high impact resin for denture (powder+liquid) vertex,holland 3. extra hard type iv dental stone zhermak , italy 4. separating medium isodent,spofa dental czechoslovakian europe 5. distilled water iraq 6 artificial teeth acrylic, florident 7 thinner dynacoat thinner standar netherlands conventional artificial teeth (acrylic, florident) were chosen to be bonded to two types of denture bases: (group a heat cure, and group b high impact denture bases), total of 80 acrylic teeth 40 teeth for each group (20 teeth for heat cure (conventional cure) and 20 teeth for autoclave cure), each subgroup contained: 1-five acrylic teeth with out any surface treatment (control). 2five acrylic teeth with diatoric preparation (retention grooves). 3five acrylic teeth conditioned with thinner. 4five acrylic teeth with retention grooves and thinner. all denture teeth were maxillary central incisors. for each denture base, the teeth were waxed onto the beveled surface of a rectangular wax block (figure 1). the slope of the beveled surface aligned each artificial tooth such that the long axis of the tooth was at 45 degrees from the base of the wax block as shown in figure 2. figure 1: acrylic teeth attached to waxed blocks. figure 2: the configuration of the specimen (jist6506 1989) j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 73 the denture teeth were flasked and the wax was eliminated with running hot water. the ridge lap surfaces of the artificial teeth were treated with chemical solvent (thinner for acrylic teeth) or were prepared by diatoric or a combination of both or with no surface treatment. the diatoric was prepared by cutting a groove (2mm width and 3mm depth) mesio-distally drilled into the ridge lap surface of each artificial tooth with an inverted cone bur. the artificial teeth that did not undergo any surface treatment were used as controls.no.0 brush was used for painting the teeth surfaces with thinner at room temperature for three minutes (11). for both heat cured acrylic and high impact acrylic, the denture resins were packed in flask for heat processed by conventional waterbath processing technique (74°c for 1.5 hours then boil for 30 minutes) and experimental groups (group b 40 samples) in which acrylic resins were processed by autoclave at 121°c, 210kpa for 30min., then they were tested . shear load was applied at 45 degrees from the long axis of each denture tooth on the palatal surface at a cross head speed of 1.5mm/min with 20 kn load until fracture. the shear bond strength was calculated based on the force (f) in (n) at fracture and adhesive surface area (s) in (mm²) and converted to (mpa). [[b.s= f/s]] b.s= bond strength (n/mm²) or (mpa). f= force at failure (n). s= surface area of cross section in (mm²) and this was calculated automatically by the program of the instron machine (12) (figure 3). s= (π / 4) * d² π= 22/7 or 3.14 d (diameter) = 5 mm. s= 19.64 mm² specimen attached to metal fixture fixed on the instron machine immediately to avoid the stress relaxation and subjected to shear stress until failure (13). figure 3: instron machine with tooth clamp statistical analyses the data were subjected to computerized analysis using spss program version 21. the statistical analyses included; descriptive statistics (means, standard deviations, minimum and maximum values and statistical tables), while one-way anova test for comparison among the groups then lsd test if anova showed significant difference and t test results descriptive statistic showed that for heat cure acrylic samples, the lowest mean value for the shear bond was for that specimens processed by water bath and autoclave processing for the subgroup of samples without surface treatment (control group), and the highest value for the group that undergo mechanical and chemical treatment, the same result were seen in the high impact acrylic samples for both processing methods (table1). j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 74 table 1: descriptive statistics types of acrylic types of processing n mean s.d. min. max. heat cure water bath 1 5 8.636 0.30 8.30 9.01 2 5 9.38 0.36 8.91 9.72 3 5 9.20 0.35 8.70 9.62 4 5 14.28 0.70 13.24 15.17 autoclave 1 5 8.64 0.17 8.45 8.91 2 5 9.69 0.40 9.06 10.13 3 5 9.25 0.28 8.91 9.62 4 5 14.25 0.46 13.64 14.74 high impact water bath 1 5 7.90 0.27 7.50 8.20 2 5 9.85 0.51 9.11 10.43 3 5 9.32 0.76 8.14 10.18 4 5 13.92 0.69 12.78 14.56 autoclave 1 5 8.56 0.24 8.30 8.91 2 5 10.70 0.38 10.23 11.25 3 5 7.93 0.36 7.53 8.40 4 5 14.55 0.30 14.20 14.86 the one way anova revealed highly significant difference in high impact acrylic processed by autoclave method (p<0.001) with significant difference in heat cured acrylic processed by the two methods also there were high significant differences in the artificial teeth surface treatments and denture base interactions (p<0.001) (tables 2 and 3). table 2: comparison among groups in each type of processing in different surface treatment types of acrylic types of processing anova sum of squares df mean square f-test p-value heat cure water bath between groups 103.424 3 34.475 166.308 0.000 (hs) within groups 3.317 16 0.207 total 106.741 19 autoclave between groups 98.476 3 32.825 270.781 0.000 (hs) within groups 1.940 16 0.121 total 100.416 19 high impact water bath between groups 99.976 3 33.325 95.367 0.000 (hs) within groups 5.591 16 0.349 total 105.567 19 autoclave between groups 133.813 3 44.604 417.312 0.000 (hs) within groups 1.710 16 0.107 total 135.523 19 table 3: lsd test after anova types of processing heat cure acrylic high impact acrylic mean difference p-value mean difference p-value water bath 1 2 -0.740 0.021 (s) -1.958 0.000 (hs) 3 -0.564 0.068 (ns) -1.428 0.002 (hs) 4 -5.648 0.000 (hs) -6.020 0.000 (hs) 2 3 0.176 0.550 (ns) 0.530 0.175 (ns) 4 -4.908 0.000 (hs) -4.062 0.000 (hs) 3 4 -5.084 0.000 (hs) -4.592 0.000 (hs) autoclave 1 2 -1.052 0.000 (hs) -2.136 0.000 (hs) 3 -0.612 0.013 (s) 0.634 0.007 (hs) 4 -5.606 0.000 (hs) -5.984 0.000 (hs) 2 3 0.440 0.063 (ns) 2.770 0.000 (hs) 4 -4.554 0.000 (hs) -3.848 0.000 (hs) 3 4 -4.994 0.000 (hs) -6.618 0.000 (hs) j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 75 effect of curing techniques t-test of the comparison showed that the high impact acrylic cured by conventional generally possessed significantly higher shear bond strength than the heat cured acrylic in autoclave processing method effect of surface treatments t-test of surface treatments of artificial teeth showed that the acrylic teeth had higher bond strength than the control group teeth (p<0.001). diatoric preparation significantly improved the bond strength of artificial teeth (p<0.001) (table 4). the application of thinner to acrylic teeth significantly enhanced the bond strength also the combination of thinner treatment with the diatoric preparation gives the highest bond strength of these teeth to both types of denture base material for both types of processing (table 5). a. thinner wetting: thinner wetting improve the s.b.s. significantly high (p≤0.001) in all thinner conditioned acrylic teeth bonded to both control and experimental denture bases (table 5). table 4: comparison between the types of processing for each type of acrylic types of acrylic types of processing descriptive statistics processing types comparison mean s.d. t-test df p-value heat cure 1 water bath 8.64 0.30 -0.041 8 0.968 (ns) autoclave 8.64 0.17 2 water bath 9.38 0.36 -1.309 8 0.227 (ns) autoclave 9.69 0.40 3 water bath 9.20 0.35 -0.269 8 0.795 (ns) autoclave 9.25 0.28 4 water bath 14.28 0.70 0.097 8 0.925 (ns) autoclave 14.25 0.46 high impact 1 water bath 7.90 0.27 -4.064 8 0.004 (hs) autoclave 8.56 0.24 2 water bath 9.85 0.51 -2.944 8 0.019 (s) autoclave 10.70 0.38 3 water bath 9.32 0.76 3.703 8 0.006 (hs) autoclave 7.93 0.36 4 water bath 13.92 0.69 -1.867 8 0.099 (ns) autoclave 14.55 0.30 table 5: comparison between the types of acrylic for each type of processing types of processing types of acrylic descriptive statistics acrylic types comparison mean s.d. t-test df p-value water bath 1 heat cure 8.636 0.30 4.056 8 0.004 (hs) high impact 7.90 0.27 2 heat cure 9.38 0.36 -1.702 8 0.127 (ns) high impact 9.85 0.51 3 heat cure 9.20 0.35 -0.330 8 0.750 (ns) high impact 9.32 0.76 4 heat cure 14.28 0.70 0.839 8 0.426 (ns) high impact 13.92 0.69 autoclave 1 heat cure 8.64 0.17 0.595 8 0.568 (ns) high impact 8.56 0.24 2 heat cure 9.69 0.40 -4.022 8 0.004 (hs) high impact 10.70 0.38 3 heat cure 9.25 0.28 6.499 8 0.000 (hs) high impact 7.93 0.36 4 heat cure 14.25 0.46 -1.212 8 0.260 (ns) high impact 14.55 0.30 j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 76 discussion effect of surface treatments the placement of groove significantly improved the bond strength of artificial teeth, the use of thinner for acrylic teeth achieved even higher shear bond strength (14). the benefit of using diatoric groove may be explained by that, the diatoric provide a wider contact area with denture base resin and greater mechanical retention and, increases the surface area on the artificial teeth available for the polymerizing denture base to interact with. also, the diatoric of the denture base resin embedded in the artificial tooth creates a path of resistance to fracture in a direction different from the tooth– denture base interface. these mechanically strengthen the bond between the artificial tooth and the denture base (13,15). a.thinner wetting thinner wetting improved the shear bond strength significantly, these effects were due to that thinner wetting which is a strong solvent since it is chemically composed from multiple solvents could dissolve the polymer that facilitated the diffusion of the polymerizable monomer from the denture base to the surface treated tooth that facilitate the creation of a more interwoven polymer network for both types of acrylic. these findings were similar to those of previous studies like other studies (16,17). effect of curing technique in high impact acrylic, the results showed that there was a highly significant difference in shear bond between autoclave and water bath methods. this may be caused by the pressure, that speeding up the initial polymerization and elevating the boiling temperature of the monomer and thus might reduce the residual monomer content (18), too rapid a rise in temperature produces large numbers of radicals and, as a result, many growing polymer chains. these chains collide either with other radicals or with polymer chains, producing an increase in branching and crosslinking of the interstitial polymer (19), no previous study investigated the effect of autoclave processing on the shear bond strength of acrylic teeth to high impact acrylic resins were found to further investigate the effect of autoclave curing on various types of resins, and effect of time and temperature of autoclave curing, more detailed studies should be carried out. under the conditions of this study, it could be concluded that autoclave polymerization was a potential alternative method for processing denture base resins. autoclave polymerization can be easily performed in laboratory conditions. in high impact acrylic, there were highly significant differences of autoclave processing technique compared with water bath regarding the shear bond strength with acrylic teeth. references 1. sideridou id. polymeric materials in dentistry. new york: nova science publishers, inc.; 2011. p.21. 2. jagger d, harrison aj. the reinforcement of dentures. j oral rehabil 1999; 26: 185-94. 3. powers jm, sakaguchi r. craig’s restorative dental materials. 13th ed .philadelphia: pa mosby co; 2012. p.101. 4. mang trj, latta ma. physical properties of four acrylic denture base resins. j contemporary dental practice 2005; 15(6): 93-100. 5. azzari mj, cortizo ms, alessandrini jl. effect of the curing conditions on the properties of an acrylic denture base resin microwave polymerized. j dent 2003; 31: 463-8. 6. kawara m, carter jm, ogle re. bonding of plastic teeth to denture base resins. j prosthet dent 1991; 66: 566-71. 7. undurwade jh, sidhaye a. curing acrylic resin in a domestic pressure cooker: a study of residual monomer content. quintessence int1989; 20(2): 123-9. 8. barbosa db, barão var, monteiro dr, marra j, pero ac, compagnoni ma. a technique for fabrication specimens for shear bond test using an embedded machine. rev odontol unesp 2007; 36(2):189-92. 9. teraoka f, nakagawa m, takahashi j. adaptation of acrylic dentures reinforced with metal wire. j oral rehabil 2001; 28: 937-42. 10. caradash hs, applebaum b, baharav h, librman r. the effect of retention grooves on tooth –denture base bond. j prosthet dent 1990; 64(4): 492-6. 11. al-ani mj. the effect of different surface treatment on the transverse strength and deflection of repaired acrylic specimens. a master thesis, college of dentistry, university of baghdad, 2000. 12. chai j, takahashi y, takahashi t, habu t. bonding durability of conventional resinous denture teeth and highly cross-linked denture teeth to a pour type denture base resin. int j prosthodont 2000; 13(2):1126. 13. hussain na. the shear bond strength of artificial teeth with denture bases. a master thesis, college of dentistry, university of baghdad, 2000. 14. hiroyuki m, shiro s, yoshitom, hisanori k, takuo t. in vitro evaluation of the influence of repairing condition of denture base resin on the bonding of autopolymerized resins. j prosthet dent 2004; 91: 164-70. 15. saavedra g, neisser mp, sinhoreti mac, machado c. evaluation of bond strength of denture teeth bonded to heat polymerized acrylic resin denture bases. braz j oral sci 2004; 3: 458-64. 16. delbert t. coat oil was useful all-purpose home remedy. texas escapes. blue prints for travel, llc.2007; ch. 4; p: 65. 17. arima t, nikawa h, murata h, hamada t, harsini. composition and effect of denture base resin surface primer for reline acrylic resin. j prosthet dent 1996; 75(4): 457-62. j bagh college dentistry vol. 26(4), december 2014 evaluation of shear restorative dentistry 77 18. undurwade jh, sidhaye ab. curing acrylic resin in domestic pressure cooker: a study of residual monomer content, quintessence int 1989; 20(2):123-9. 19. o’brien wj. dental material and their selection. 3rd ed. quintessence publishing co, inc.; 2000. p.135. raja.doc j bagh college dentistry vol. 26(4), december 2014 salivary micrornas oral diagnosis 120 salivary micrornas (hsa-mir-200a, hsa-mir-125a and hsamir-93) in relation to age, gender and histopathological parameters. shaimaa h. mudhir, b.d.s., m.sc. (1) raja h. al-jubouri, b.d.s., m.sc., ph.d. (2) ban a. abdul majeed, m.b.ch.b., m.sc., ph.d. (3) abstract background: micrornas (mirnas) are small noncoding rnas that post‐transcriptionally regulate gene expression by targeting specific mrnas. the main objective of this study was measure the level of salivary (hsa-mir-200a, hsa-mir125a and hsamir-93) in both oral squamous cell carcinoma and healthy controls to asses the association of them with age, gender and tumor grade materials and methods the level of three salivary micrornas namely hsa-mir-200a, hsa-mir-125a and hsamir-93 were measured in saliva of patients with oral squamous cell carcinoma and healthy controls by using reveres transcription, preamplification and quantitative pcr also the general information from each patient including the age, sex and tumor grade were recorded. results: salivary mir-200a was down regulated while mir-93 was up regulated in saliva of females with oscc compared to females of healthy control, also there was a weak and statistically insignificant positive linear correlation between tumor grade and hsa-mir-200a ct values (r=0.223).however each tumor grade group had a mean normalized ct value which was higher than that of controls with statistically significant differences, p<0.05. the results suggest that circulating mirnas may be a biological marker of aging and tumor grade. more studies should be done to validate these results. conclusions: both mir-200a and mir-93 could be used as biomarkers for poorly differentiated and aggressive cancer key words: saliva, mir-200a, mir-125a, mir-93, oscc, tumor grade, real time-pcr. (j bagh coll dentistry 2014; 26(4):120-125). الخالصة ك ان الھ دف الرئیس ي م ن ھ ذه الدراس ة قی اس مس توى . mrnasم ن خ الل اس تھداف النسخ الجیني ھي الرنا غیر المكودة الصغیرة التي تنظم التعبیر ما بعد micrornas :خلفیة )mir-200a, mir-125a, mir-93 (درج ة التق دم ف ي العم ر والج نس و عودراسة عالقة كل منھ ا م االصحاء مجموعةوللفم سرطان الخالیا الحرشفیة مرضى كل من لعاب في و للف م ف ي اللع اب م ن المرض ى ال ذین یع انون م ن س رطان الخالی ا الحرش فیة )mir-200a, mir-125a, mir-93( اللعابی ة وھ ي micrornasالورم تم قیاس مستوى ثالث ة المعلومات العام ة سجلت أیضا real-time pcrالكمي القیاس و preamplificationالتضخیم ، ) revers transcription(العكسي االصحاء باستخدام النسخمجموعة . من كل مریض بما في ذلك السن والجنس و درجة الورم ، اءحص مجموع ة اال مقارن ة باإلن اث م ن م ن مرض ى س رطان الخالی ا الحرش فیة للف م إلن اث لف ي اللع اب اعل ى مس توى mir-93في ح ین اقل mir-200aیكون مستوى :النتائج مع دل ورم و، ولك ن ك ان لك ل مجموع ة درج ة ) mir-200a )0.223 =r ل ـ ctق یم وأیضا كان ھناك وجود عالقة خطیة إیجابیة ضعیفة وتكاد ال تذكر إحص ائیا ب ین درج ة ال ورم و ودرج ة ال ورم لتق دم العم ر ق د یك ون عالم ة بیولوجی ة mirnasعم یم تشیر النتائج إلى أن ت. p < 0.05مع فروق ذات داللة إحصائیة ، مجموعة االصحاء أعلى من المطبعة ct قیم .وینبغي أن یتم المزید من الدراسات للتحقق من صحة ھذه النتائج. الصف .ذات صفة سیئة التباین والعداونیة ي لسرطان الخالیا الحرشفیة للفم شر حیویمكن ان تستخدم كمؤ mir-93و mir-200a كال :االستنتاجات introduction oral squamous cell carcinoma is a common human malignant tumor with an increasing incidence. oral squamous cell carcinoma has long been considered to be a tumor of the elderly and has been seen only sporadically before the third decade of life. the association of oral cancer with aging could be resulted from prolonged exposure to environmental carcinogens such as chemicals, radiation and viruses which are important promoting factors in the development of oral cancer (1). accumulative effects of these carcinogens through out prolonged exposure of the life in elderly patients may explain the increased incidence with aging (2). (1)ph.d. student, department of oral diagnosis, college of dentistry/ baghdad university. (2)professor, department of oral diagnosis, college of dentistry/ baghdad university. (3)professor, department of pathology and forensic medicine, college of medicine/ al-nahrain university. micrornas, a family of an average 22 nucleotide long are non coding mirna which play an important role in gene regulation. they are important in many biological and cellular processes including development, differentiation, cell cycle control and oncogenesis (3). a significant amount of mirna have been found in extra cellular human body fluids including blood plasma, urine, saliva and semen (4-7). three important observations early in the history of mirnas suggested a potential role in human cancer. firstly, the earliest mirnas discovered in the roundworm c. elegans and the fruit fly drosophila were shown to control cell proliferation and apoptosis (8). their deregulation may therefore contribute to proliferative diseases such as cancer. secondly, when human mirnas were discovered, it was noticed that many mirna genes were located at fragile sites in the genome or regions that are commonly amplified or deleted in human cancer j bagh college dentistry vol. 26(4), december 2014 salivary micrornas oral diagnosis 121 (9). thirdly, malignant tumors and tumor cell lines were found to have widespread deregulated mirna expression compared to normal tissues (10). materials and methods twenty seven patients with oral squamous cell carcinoma were recruited at the maxillofacial surgery clinic of ghazi alhariri hospital, alkadhimia, al-ramadi and al-yarmouk teaching hospital. the general information was taken from each patient including the name, age and sex. patients consents for participation in the study were also taken. a group of apparently healthy individuals with age and sex matching to patients served as a control group. un stimulated whole saliva samples( for all patients and controls) were collected between 8 a.m and 11a.m. subjects were asked to refrain from eating, drinking, smoking or oral hygiene procedures at least 1 hour before collection.(11) saliva samples were centrifuged at 2600rpm for 15 minutes at 4 c. the supernatant was removed from the pellet and treated with superase (rnase inhibitor). for each 400µl of saliva supernatant 20µl of superase were added. the saliva samples were then kept at -80 c until the time of rna extraction.(5) 1. saliva rna extraction: steps were conducted following the instruction leaflet of mirvana mirna extraction and according to the manufacturer (ambion, usa). two hundred microliters of the supernatant saliva were used for rna extraction by using the mirvana mirna isolation kit according to the instructions of the manufacturer. 2. reverse transcription: steps of the procedure were conducted according to the kit leaflet and according to the manufacture instructions of taqman® microrna rt kit (applied biosystems, usa). 3. preamplification reaction steps of the procedure were conducted according to the kit leaflet and according to the manufacture instructions taqman® preamp master mix protocol (applied biosystems, usa). 4. real-time pcr reaction steps of the procedure were conducted according to the kit leaflet and according to the manufacture instructions (applied biosystem, usa). statistical analysis of data 1. statistical packages for social sciencesversion 20 (spss-20) was applied to analyze demographic criteria of study and control groups. data were arranged as frequencies and the chisquare extracted p value was taken as significant when < 0.05. 2. real-time pcr data analysis after the end of experiment the qrtpcr machine displayed the data as ct (cycle threshold) value for each sample, ct value corresponds to the number of amplification cycles required for the fluorescent signal to exceed the background level. this means that ct levels are inversely proportional to the amount of products in the sample, i.e. a low ct value means a high expression of the mirna and vice versa. moreover, in this study mirnas with a ct value above 40 cycles are considered non-expressed.(12) a. the data included: • ct values for hsa-mir-200a for oscc and healthy controls group. • ct values for hsa-mir-125a for oscc and healthy controls groups. • ct values for hsa-mir-93 for oscc and healthy controls groups. b. normalization of data: for each array the mean expression value was calculated, without prior removal of ct values ≥ 35, and thereafter divided with each individual mirnas ct value (13). results and discussion salivary hsa-mir-200a, hsa-mir-125a and hsamir-93 levels in relation to gender and age the present study revealed a statistically significant difference in saliva level of mir-200a and mir-93 between females of oscc and healthy controls (p=<0.001, 0.016) respectively, whereby mir-200a was down-regulated in saliva of females with oscc while mir-93 was upregulated in saliva of females with oscc. these mirnas (mir-200a, mir-125a and mir-93) did not show any statistical difference between males of oscc and healthy controls groups. however, these differences should raise the possibility of hormonal influences to be responsible for them. this necessitates more studies to be conducted to relate hormones to mirnas expression in oscc. aging is a highly complex process where over time the accumulation of cellular and molecular damage leads to the functional decline of tissues and organs that eventually increase disease susceptibility and mortality. although aging can be influenced by environmental factors also play a definitive role in regulating lifespan. in particular, modulation of gene expression in model j bagh college dentistry vol. 26(4), december 2014 salivary micrornas oral diagnosis 122 organisms has been shown to affect longevity.(14,15) it has been shown that mirnas are differentially expressed with age in mouse brain, liver and skeletal muscle; however, the expression pattern appear to be tissue specific (1618). also in human, mirnas expression showed change with human age in peripheral blood mononuclear cells (pbmcs) (19). specifically it was found that the majority of mirnas are downregulated with age and 9 age-associated mirnas significantly decreased in abundance in older individuals (mean age 64) compared to young individuals (mean age 30) (20) in considering the relation to age, only mirna 125a was associated with a significant difference between age groups in the control group whereby it was up regulated in individuals <50 years and down regulated in those >65, indicating a change in expression with age table 3.15, however this finding was not observed in oscc patients. it appears that the malignant process itself has some degree of modification on mirna expression that overrides the affect of age. while mir-93 showed increased level with age with no significant difference between different age groups in both oscc and healthy control groups, this result in agreement with zhang x et al. (21) who found that mir-93 had an age-related increase. salivary hsa-mir-200a, hsa-mir-125a and hsamir-93 levels and tumor grade taking into consideration tumor grades, the results of the present study revealed wide variation. generally speaking, taking all grade groups from one side and control group from the other side, the liner correlation did not give any significant statistical differences for all the studied mirnas. mirna-200a was significantly down regulated in all grades of oscc (higher ct values) in comparison with control group (lower ct values). this is in agreement with mongroo and rutgi (22) who found similar results and suggested that mir-200 family could be considered as putative tumor suppressor and that they could definitely serve as a biomarker mainly in poorly differentiated malignancies. although mir-125a showed the same changes i.e. down regulation in all grades, and in steady increase with advancing grade, the differences were not significant when compared to control. while mirna-93 was associated with up regulation in different grades although in a non significant manner. however, the difference between the expression in poorly differentiated group significantly differed from that of the control, suggesting its usefulness as a biomarker to predict higher grades of oscc. table 1: the case-control difference in mean normalized ct values of 3 selected mirna stratified by gender case-control comparison controls cases (ossc) p (t-test) a) female normalized ct value for hsa-mir-200a <0.001 range (0.91 1.07) (1 1.12) mean 1 1.07 sd 0.04 0.04 se 0.011 0.011 n 15 12 normalized ct value for hsa-mir-125a 0.77[ns] range (0.93 1.08) (0.91 1.09) mean 1 1 sd 0.04 0.05 se 0.009 0.014 n 15 13 normalized ct value for hsa-mir-93 0.016 range (0.9 1.12) (0.82 1.05) mean 1 0.93 sd 0.07 0.07 se 0.017 0.02 n 15 13 b) male normalized ct value for hsa-mir-200a 0.1[ns] range (0.95 1.11) (0.98 1.12) mean 1.02 1.05 sd 0.05 0.04 j bagh college dentistry vol. 26(4), december 2014 salivary micrornas oral diagnosis 123 se 0.015 0.01 n 12 14 normalized ct value for hsa-mir-125a 0.16[ns] range (0.95 1.15) (0.88 1.05) mean 1.02 0.98 sd 0.07 0.04 se 0.021 0.011 n 11 14 normalized ct value for hsa-mir-93 0.96[ns] range (0.79 1.08) (0.83 1.1) mean 0.97 0.97 sd 0.09 0.07 se 0.025 0.019 n 12 14 table 2: the mean normalized ct values of 3 selected mirna by tumor grade controls well differentiated oscc moderately differentiated oscc poorly differentiate d oscc p (anova trend) for tumor grade normalized ct value for hsa-mir-200a 0.1[ns] range (0.91-1.07) (0.981.12) (1 1.12) (1.09 1.1) mean 1 1.05 1.05 1.09 sd 0.04 0.04 0.04 0.01 se 0.011 0.015 0.01 0.005 n 15 9 13 3 p (anova) = <0.001 well differentiated x control = 0.011 moderately differentiated x control = 0.004 poorly differentiated x control = 0.002 r=0.223 p=0.28[ns] normalized ct value for hsa-mir-125a 0.47[ns] range (0.93-1.08) (0.951.09) (0.881.08) (1 1.03) mean 1 0.99 1 1.01 sd 0.04 0.04 0.05 0.01 se 0.009 0.015 0.013 0.008 n 15 9 14 3 p (anova) = 0.8[ns] well differentiated x control = 0.39[ns] moderately differentiated x control = 0.58[ns] poorly differentiated x control = 0.84[ns] r=0.266 p=0.19[ns] normalized ct value for hsa-mir-93 0.17[ns] range (0.91.12) (0.821.07) (0.83 1.1) (0.870.92) mean 1 0.96 0.95 0.89 sd 0.07 0.07 0.07 0.02 se 0.017 0.023 0.02 0.013 n 15 9 14 3 p (anova) = 0.16[ns] well differentiated x control = 0.33[ns] moderately differentiated x control = 0.2[ns] poorly differentiated x control = 0.041 r=-0.24 p=0.24[ns] note: r (the linear correlation coefficient) was calculated between tumor grade and normalized ct values j bagh college dentistry vol. 26(4), december 2014 salivary micrornas oral diagnosis 124 table 3: the mean normalized ct values of 3 selected mirna by age group stratified by casecontrol group membership age group (years) p (anova trend) <50 50-65 >65 a) control group normalized ct value for hsa-mir200a 0.97[ns] range (0.91 1.03) (0.95 1.11) (0.98 1.01) mean 0.99 1.02 0.99 sd 0.05 0.05 0.01 se 0.02 0.012 0.008 n 6 18 3 r=-0.145 p=0.47[ns] normalized ct value for hsa-mir125a 0.06[ns] range (0.98 1.08) (0.93 1.14) (1.01 1.15) mean 1 1 1.07 sd 0.04 0.05 0.07 se 0.015 0.011 0.043 n 6 17 3 r=0.231 p=0.26[ns] normalized ct value for hsa-mir-93 0.21[ns] range (0.91 1.1) (0.79 1.12) (0.86 0.99) mean 1.01 0.99 0.94 sd 0.07 0.08 0.07 se 0.028 0.019 0.042 n 6 18 3 r=-0.113 p=0.57[ns] b) cases group normalized ct value for hsa-mir200a 0.58[ns] range (1.03 1.1) (1 1.1) (0.98 1.12) mean 1.05 1.05 1.07 sd 0.03 0.04 0.04 se 0.016 0.011 0.013 n 4 12 10 r=0.128 p=0.53[ns] normalized ct value for hsa-mir125a 0.5[ns] range (0.95 1.03) (0.88 1.09) (0.94 1.08) mean 0.98 0.99 1 sd 0.03 0.05 0.05 se 0.012 0.016 0.015 n 5 12 10 r=0.092 p=0.65[ns] normalized ct value for hsa-mir-93 0.3[ns] range (0.87 1.02) (0.82 1.1) (0.83 1.07) mean 0.97 0.96 0.93 sd 0.06 0.07 0.08 se 0.027 0.021 0.024 n 5 12 10 r=-0.205 p=0.31[ns] j bagh college dentistry vol. 26(4), december 2014 salivary micrornas oral diagnosis 125 references 1. soames jv, southam jc. oral pathology. 3rd ed. new york: oxford; 1998. 2. kashmoola ma. changes in the composition of saliva in oral cancer patients. ph.d. thesis. department of oral diagnosis. college of dentistry, baghdad university, 2000. 3. sassen s, miska ea, caldas c. microrn-implication for cancer. virchows arch 2008; 452(1):1-10. 4. mitchell ps, parkin rk, kroh em. circulating micrornas as stable blood-based markers for cancer detection. proc natl acad sci usa 2008; 105: 10513– 18. 5. park nj, zhou a, elashoff d, henson bs, kastratovic da. salivary microrna: discovery, characterization and clinical utility for oral cancer detection clin cancer res 2009; 15(17): 5473-7. 6. hanke m, hoefig k, merz h, feller ac, kausch i, jocham d, warnecke jm, sczakiel g. a robust methodology to study urine microrna as tumor marker: microrna-126 and microrna-182 are related to urinary bladder cancer. urol oncol 2010; 28: 655–61. 7. zubakov da, boersma w, choi y, van kuijk pf, wiemer ea, kayser m. microrna markers for forensic body fluid identification obtained from microarray screening and quantitative rt-pcr confirmation. int j legal med 2010; 124: 217–26. 8. brennecke j, stark a, russell rb, cohen s m. principles of microrna-target recognition. plos biol 2005; 3: e85. 9. calin ga, liu cg, sevignani c, ferracin m, felli n, dumitru cd, shimizu m, cimmino a, zupo s, dono m, dell'aquila ml, alder h, rassenti l, kipps tj, bullrich f, negrini m, croce cm. microrna profiling reveals distinct signatures in b cell chronic lymphocytic leukemias. proc natl acad sci usa 2004; 101: 11755-60. 10. gaur a, jewell da, liang y, ridzon d, moore jh, chen c, ambros vr, israel ma. characterization of microrna expression levels and their biological correlates in human cancer cell lines. cancer res 2007; 67: 2456–68. 11. navazesh m. methods for collecting saliva. ann ny acad sci 1993; 694: 72-77. 12. deo a, calorlsson j, lindlof a. how to choose a normalization strategy for mirna quantitative realtime (qpcr) arrays. journal of bioinformatics and computational biology 2011; 9(6): 795-812. 13. mestdagh p, van vlierberghe p, de weer a, muth d, westermann f, speleman f, vandesompele j. a novel and universal method for microrna rt-qpcr data normalization. genome biol 2009; 10:r64. 14. jung hj, suh y. microrna in aging: from discovery to biology. current genomics 2012; 13: 548‐57. 15. tacutu r, craig t, budovsky a, wuttke d, lehmann g, taranukha d, costa j, fraifeld ve and de magalhaes jp. human ageing genomic resources: integrated databases and tools for the biology and genetics of ageing. nucleic acids res 2013; 41(database issue): d1027‐1033. 16. bates dj, liang r, li n and wang e. the impact of noncoding rna on the biochemical and molecular mechanisms of aging. biochimica et biophysica acta 2009; 1790: 970‐9. 17. inukai s, de lencastre a, turner m, slack f. novel micrornas differentially expressed during aging in the mouse brain. plos one 2012; 7: e40028. 18. vikos st, slack fj. micrornas and their roles in aging. j cell sci 2012; 125:7-17. 19. noren hooten n, abdelmohsen k, gorospe m, ejiogu n, zonderman ab, evans mk. microrna expression patterns reveal differential expression of target genes with age. plos one 2010; 5:e10724. 20. noren hooten n, fitzpatrick m, wood wh, supriyo de, ejiogu n, zhang y, julie a, et al. age‐related changes in microrna levels in serum. aging 2013; 5(10): 725-40. 21. zhang x, azhar g, wei jy. the expression of microrna and microrna clusters in the aging heart. plos one 2012; 7(4): e34688. 22. mongroo ps, rustgi a k. the role of the mir-200 family in epithelial-mesenchymal transition. cancer biol ther 2010; 10(3): 219-22. 12 j bagh college dentistry vol. 33(1), march 2021 prevalence of self-reported prevalence of self-reported halitosis and associated factors in 15 years old male students in karbala city-iraq rafal abdulaziz alawsiy (1), nada jafer mh. radhi (2) https://doi.org/10.26477/jbcd.v33i1.2922 abstract background׃ halitosis is a common condition and is most often caused by a buildup of bacteria in the mouth because of gum disease, food, or plaque. it can result in anxiety among those affected, it is also associated with depression and symptoms of obsessive-compulsive disorder. this study aims to assess the prevalence of self-reported halitosis and associated factors (dental plaque, gingival condition and dental caries) in 15 years old male students in karbala city in iraq. additionally, we studied adolescents’ concern with their own breath and whether anyone had ever told them that they had halitosis. methods׃ a cross-sectional observational survey was conducted to15 years old high school students from public and private schools in the city of karbala, iraq. the random sample consisted of 400 adolescents from 44 schools. an interview with a structured questionnaire was administered along with measurement of oral parameters (pi, gi, dmf). results׃ the prevalence of self-reported halitosis was 48.50% according to question one. the prevalence of halitosis according to the total score of the questionnaire was 86.5%. 13.5% reported that they didn’t have halitosis. it is concluded that there is a high prevalence of self-reported halitosis, which is associated with a socio-economic pattern. most adolescents report a concern with their own breath. dental plaque and gingival status are associated significantly with self-reported halitosis. the high prevalence of self-reported halitosis according to the questionnaire among the students may be due to the consumption of garlic or spicy food, besides, dental plaque, gingivitis and dental caries cause an increase in volatile silver compound level which cause an increase in halitosis. conclusion׃ self-reported halitosis is a prevalent situation in about 50% of adolescents in karbala city. patients’ self -reported halitosis is found to be associated with dental plaque, gingivitis and dental caries. keywords׃ halitosis; adolescent; prevalence. (received: 15/1/2021, accepted: 24/2/2021) introduction halitosis is a state in which respired air is offensively changed both for patients and for people with whom they communicate (1). it distresses millions of people around the world, although its prevalence fluctuates, seemingly elicited by the shortage of oral hygiene and a disorganized lifestyle. it can cause social restrictions, interfere in the quality of life, and maybe a gauge of important systemic diseases. in most societies where halitosis is prevalent, people look for solutions, usually due to the discomfort or embarrassment to which they are subjected (2). one of the aims for studying halitosis is its social impact as a result of patients feeling unconfident in social, professional and family contacts. it may also affect the quality of life and cause embarrassment to people relating to the individual with bad breath. the measurement of volatile sulfur compound (vsc) concentrations in the exhaled air to assess halitosis is the only method used in some studies. (1) mater student, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad. corresponding email, nooraliomran88@gmail.com the results of these surveys have a different meaning from studies that determine the percentage of people who report having halitosis by a questionnaire (1). both conclusions are meaningful to understanding the issue, but observation through vsc monitors is considered a surrogate conclusion (measure the disease route, and in general it is therapy centred) (3), whereas self-reported awareness of halitosis is documented as a true outcome. epidemiological observation taking into consideration both types of outcomes provides important information and allows broader acceptance of the issue (1). adolescence is the evolution period between childhood and adulthood and is categorized by several changes in biological, psychological and social development (4). adolescents are subject to several health linked signs, including halitosis, which exceeds the biological scope, affecting the social scope and possibly hurting the physical and psychological health of affected individuals (5). furthermore, the presence of halitosis may indicate incidence of important systemic diseases requiring crucial diagnosis and treatment. nevertheless, in iraq there are limited papers on adolescents, and still fewer on adolescent halitosis. https://doi.org/10.26477/jbcd.v33i1.2922 mailto:nooraliomran88@gmail.com 13 j bagh college dentistry vol. 33(1), march 2021 prevalence of self-reported materials and methods study design/study setting this study was a cross-sectional study that was carried out during the period between december 2019 and february 2020. the survey was conducted among secondary schools in karbala city-iraq. the age was taken according to the criteria of the world health organization (1997) and according to the last birthday. the size of the sample composed of 400 students who were randomly selected from 5477. ❖ (the students with the systemic disease were excluded, besides, students in the study were free of: a) medical history of infectious diseases. b) malocclusion and draining fistulas associated with chronic alveolar abscesses. c) usage of any chemical form of plaque control. d) presence of crowding/overlapping of teeth. ❖ the children were examined by the single calibrated examiner for the following clinical parameters: 1. self-reported halitosis by questionnaire. 2. plaque by using the plaque index (pi) developed by silness and loe (1964) (6). 3. dental gingival health—to check the gingival health of the subject, the gingival index (gi) developed by loe and silness (1963) (7) was used. 4. dental caries—decayed, missing, filled teeth index (dmf-t, dmf-s index) (who 1987) for permanent teeth. questionnaire a well-made format (questionnaire) was designed from previous studies (2,8,9,10) and administered to the students who meet the criteria the questionnaire was tested in a pilot study on 100 male students and validity and reliability was adopted, the questionnaire was adjusted in the light of pilot responses. the questionnaire was anonymous (no identification of an individual was possible). the questionnaire originally formulated in english, subsequently translated into arabic and then retranslated into english, and ethical approval was achieved from the ethical committee in the college of dentistry and from the psychological department of the faculty of arts in baghdad university. statistical analysis data were translated into a computerized database structure. an expert statistical counsel was sought. data description, analysis and presentation were performed using statistical package for social science (spss version 21; chicago, in press, usa), sample size calculator for prevalence studies (version 1.0.01) done by daniel ww, 1999. statistical analyses can be classified into two categories: 1-descriptive analysis: frequencies and percentage for nominal variables, minimum, maximum, mean, standard deviation (sd) and standard error (se) for quantitative variable 2inferential analysis: a. independent sample t-test: test the difference between two independent groups. b. paired sample t-test: test the difference between two related means for one sample or two raters. ❖ level of significance as not significant p>0.05, significant p<0.05, highly significant p<0.01. results the prevalence of halitosis among 400 students aged 15 years of male’s secondary schools in karbala city/iraq was 48.50% according to question one, as seen in the table (1). regarding question one of the self-reported questionnaire of halitosis, as illustrated in table 2, the mean value of plaque index and gingival index among students with halitosis is higher than those with no halitosis, which was statistically significant, (p<0.001). the findings of plaque index regarding the selfreported questionnaire of halitosis were illustrated in table (3), the mean values of plaque index among students with halitosis were higher than those without halitosis, the higher mean value was recorded in question (4), which was asking the students if their breath interfered with social life. these findings were statistically significant, (p<0.001). similarly, the mean value of the gingival index among students regarding the self-reported questionnaire of halitosis, was seemed to be higher in students with halitosis than without halitosis, (table 4). the higher mean value was recorded in question (3), which was asking the students about receiving any professional treatment for halitosis. this finding were statistically significant, (p<0.001). however, the last question (q7), which asked the students if they take any measures against halitosis, the difference observed failed to reach the level of statistical significance (p>0.05). 14 j bagh college dentistry vol. 33(1), march 2021 prevalence of self-reported table (1): distribution of students by questionnaire. question no. percent % q1 yes 194 48.50 no 206 51.50 q2 yes 188 47.00 no 212 53.00 q3 yes 87 21.75 no 313 78.25 q4 yes 162 40.50 no 238 59.50 q5 yes 190 47.50 no 210 52.50 q6 yes 217 54.25 no 183 45.75 q7 yes 179 44.75 no 221 55.25 table (4) clarifies the mean values and standard errors (se) of the caries-experience (ds, ms, fs, dmfs and dmft) regarding the self-reported questionnaire of halitosis. the mean differences of dmft were statistically significant concerning questions (2,4,5,6,7), similarly the mean differences of ds were statistically significant concerning questions (4,5,6), likewise the fs mean differences were statistically significant concerning question (5), and the mean differences of dmfs were statistically significant concerning question (5,6,7) (p< 0.001). on the other hand, other findings were statistically not significant (p> 0.05). discussion in the present study, 400 students of 5477 aged 15 years old were selected randomly from 44 males’ secondary schools in karbala city/iraq, to measure the prevalence of self-perceived halitosis in secondary schools’ students aged 15 years, as no previous iraqi study on halitosis was done in this area for this age. the selected student was interviewed in an isolated room in each school to ensure privacy and to avoid embarrassment while answering the questionnaire, and all the oral parameters including dental plaque, gingival condition and dental caries. plaque index of silness and löe (1964) (6) and gingival index of löe and silness (1963) (7) were used to assess dental plaque and gingival health condition, respectively. these indices were used due to their flexibility, which provides the possibility of selection of index teeth for examination rather than the whole dentition and keeps the duration of examination to a minimum; in addition to their ease of application (11). the age and gender were stationary, as age was not a risk factor for the increase in the level of vscs (12). multiple regression analysis revealed that male gender was the only variable showing a significant relationship with higher questionnaire scores. these findings corroborate previous studies showing the predominance of halitosis in male children aged 6-9 years, 6 -16 years (13), and 7 15 years (14). however, a study carried out in israel (15), showed no difference between the sexes in the 5 -14 age group, nor was there a difference in the adult population (9). however, some studies have found a higher prevalence of halitosis in women (16). it is difficult to determine the actual influence of factors such as age and gender on halitosis, since breath odor may be influenced by many factors such as periodontal and dental status, dental hygiene, tongue coating, smoking, nutrition, level of education, and medication (17). self-assessment or self-perception of halitosis is a highly relevant outcome since it involves the individual in the process and makes him/her understand the importance of the condition (18). it is safe to assume self-perception as a true patientcentered outcome, which is highly recommended in present research in the health field6. in the present study the overall prevalence of halitosis according to the questionnaire (depending on the answer of question one which inquired the students if they have had bad breath to assess the awareness of the students about halitosis), the result was approaching fifty percent, this was almost similar to the results reported in qassim, saudi arabia (19), which is also lower in comparison to a study done in kinondoni (2013), but at the same time is higher 15 j bagh college dentistry vol. 33(1), march 2021 prevalence of self-reported table (2): descriptive and statistical test of plaque index and gingival index among the presence of halitosis. variables q1 t df p-value yes no mean se mean se pli 0.952* 0.035 0.747 0.032 4.311 398 0.000 s gi 0.852* 0.032 0.723 0.031 2.871 398 0.004 s **=highly significant at p <0.01 table (3) ׃ descriptive and statistical test of plaque index among questionnaire srq= self-reported questionnaire of halitosis no.= number *s꞊ highly significant p <0.01 table (4) ׃ descriptive and statistical test of gingival index among questionnaire srq categories t df p-value yes no mean ±se mean ±se q2 0.847 0.035 0.731 0.029 2.569 398 0.011 q3 0.932* 0.053 0.745* 0.025 3.447 398 0.001* q4 0.872* 0.037 0.727* 0.028 3.174 398 0.002* q5 0.872* 0.032 0.708* 0.031 3.656 398 0.000* q6 0.837* 0.030 0.725* 0.034 2.471 398 0.014* q7 0.820 0.031 0.758 0.032 1.349 398 0.178 *= highly significant at p<0.01 than the findings reported in other populations especially brazil (8), usa (1996) (20). in these studies, the gender had no statistically significant association to the outcome with similar methodology (8), so the result of the current study could be compared with these studies. the prevalence of halitosis according to total score of the questionnaire was 86.5% higher than the prevalence of halitosis in jordanian population which was 78% (10), this may be due to the overall poorer oral hygiene, or the assumption by other authors that halitosis might be an underestimated oral health problem in the general population may be true (21), or living in low-middle income countries (22). the high prevalence of periodontal diseases in low-middle income countries might cause the greater prevalence of halitosis, in addition the intake of volatile foods such as spices and garlic may lead to change in breath odor, and consequently halitosis, another cause for the great prevalence of halitosis is the dryness of the mouth which plays an important role in the formation and perpetuation of halitosis (23). plaque, composed of bacteria and salivary proteins, is one sulfur source in the oral cavity. in an epidemiological study conducted among the 2000 chinese population, plaque index is significantly correlated with vsc values (12). this finding was agreed with the data presented in this study, in which the plaque index was associated srq categories t df p-value* yes no no. mean se no. mean se q2 188 0.918* 0.034 212 0.784* 0.034 2.765 398 0.006* q3 87 1.048* 0.056 313 0.791* 0.026 4.455 398 0.000* q4 162 0.988* 0.039 238 0.751* 0.030 4.906 398 0.000* q5 190 0.986* 0.036 210 0.721* 0.031 5.626 398 0.000* q6 217 0.928* 0.032 183 0.750* 0.036 3.702 398 0.000* q7 179 0.948* 0.039 221 0.765 0.029 3.795 398 0.000* 16 j bagh college dentistry vol. 33(1), march 2021 prevalence of self-reported table (5) ׃ descriptive and statistical test of caries experience among questionnaire. srq dental caries categories t df p-value yes no mean se mean se q2 ds 2.441 0.161 2.264 0.174 0.741 398 0.459ns ms 0.186 0.069 0.189 0.066 0.026 398 0.979ns fs 1.250 0.139 1.118 0.126 0.705 398 0.481ns dmfs 3.877 0.267 3.571 0.257 0.828 398 0.408ns dmft 2.234* 0.107 1.915 0.104 2.141 398 0.033* q3 ds 2.575 0.233 2.284 0.138 1.003 398 0.316ns ms 0.230 0.113 0.176 0.052 0.469 398 0.639ns fs 1.437 0.240 1.109 0.099 1.451 398 0.148ns dmfs 4.242 0.397 3.569 0.209 1.503 398 0.134ns dmft 2.322 0.166 1.994 0.083 1.818 398 0.070ns q4 ds 2.648* 0.195 2.143 0.150 2.086 398 0.038* ms 0.154 0.068 0.210 0.065 0.575 398 0.566ns fs 1.327 0.175 1.080 0.102 1.301 398 0.194ns dmfs 4.129 0.310 3.433 0.227 1.855 398 0.064ns dmft 2.321* 0.122 1.891 0.093 2.853 398 0.005* q5 ds 2.616* 0.174 2.105 0.163 2.147 398 0.032* ms 0.158 0.064 0.214 0.070 0.592 398 0.554ns fs 1.453* 0.161 0.933 0.100 2.799 398 0.005* dmfs 4.227* 0.284 3.252 0.237 2.649 398 0.008* dmft 2.337* 0.114 1.819 0.095 3.511 398 0.000* q6 ds 2.687* 0.182 1.945 0.142 3.127 398 0.002* ms 0.253 0.075 0.109 0.054 1.513 398 0.131ns fs 1.221 0.117 1.131 0.150 0.480 398 0.632ns dmfs 4.161* 0.261 3.185 0.255 2.647 398 0.008* dmft 2.323* 0.101 1.760 0.106 3.819 398 0.000* q7 ds 2.508 0.167 2.217 0.168 1.214 398 0.226ns ms 0.168 0.067 0.204 0.067 0.376 398 0.707ns fs 1.346 0.165 1.045 0.103 1.606 398 0.109ns dmfs 4.022 0.281 3.466 0.245 1.498 398 0.135ns dmft 2.229* 0.120 1.932 0.093 1.984 398 0.048* with halitosis. however, another study showed no significant association between plaque accumulation and halitosis in 2000 belgian patients (24), this was inconsistent with the findings of liu et al. (2006) and kanehira et al. (2004) (plaque index). gingivitis is reversible and infrequently developed to periodontitis in children and adolescent except in special circumstances like aggressive periodontitis and periodontitis associated with systemic diseases (25). in the current study the finding is consistent with liu et al. (2006) (12), kara et al. (2006) (26), p. s. patil et al. (2014) (27), alsaidy (2013) (28), ziaei n (2019) (29) and alzoman h. (2020) (30). although halitosis is possibly not caused by periodontal disease, there is ample proof to suggest that periodontal disease increases the severity of halitosis with higher production of volatile sulphur compounds (27). this can be explained as periodontal conditions favour bacterial growth and retention of debris, besides, the blood decomposition products can themselves produce sulphur containing peptides and amino acids that are the source of volatile sulphur compounds. however, kanehira et al. (2004) (31) reported no association between halitosis and periodontal condition. in the present study, there was a highly significant association between dental caries experience represented via dmf index and self-reported halitosis, which was in agreement with cm kayombo (2017) (20). the findings were opposing with those of miyazaki et al. (1995) (32), kanehira et al. (2004) (31) and liu et al. (2006) (12). glucose and sucrose can constrain the enzymee activity of salivary peptides by making an acidic environment (33). therefore, an acidic condition created by dental plaque may destroy vsc production. however, 17 j bagh college dentistry vol. 33(1), march 2021 prevalence of self-reported nalcaci et al. (2008) (34) found that the prevalence and severity of dental caries had a significant role in halitosis, as an increase in dmft indicates an increase in caries and a low oral hygiene level, and it seems rational that this may increase the chance of halitosis. previous studies have shown that this is true (29), this was a result to increase the incidence of unidentifiable gram-negative rods, gram-positive rods and gram-negative coccobacilli, the increase in species diversity found in halitosis samples proposes that halitosis may be the result of complex collaborations between several bacterial species (35). conclusion patients’ self-reported halitosis was found to be associated with dental plaque, gingivitis and dental caries. the existing findings suggest that a selfreported questionnaire of halitosis can be used to judge one’s halitosis. references 1. rösing ck, loesche w. halitosis: an overview of epidemiology, etiology and clinical management. braz oral res 2011; 25: 466471. 2. eldarrat ah. influence of oral health and lifestyle on oral malodour. int dent j 2011; 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11:61−63. المستخلص ؤدي رائحة الفم الكريهة هي حالة شائعة وغالبًا ما تحدث بسبب تراكم البكتيريا في الفم بسبب أمراض اللثة أو الطعام أو البالك. يمكن أن ي ׃خلفيةال لفم كما أنه يرتبط باالكتئاب وأعراض اضطراب الوسواس القهري. كان الهدف من هذه الدراسة هو تقييم انتشار رائحة ا المتضررين،إلى القلق بين سنة في مدينة كربالء 15حالة اللثة وتسوس األسنان( لدى الطالب الذكور في سن األسنان، الكريهة المبلغ عنها ذاتيا والعوامل المرتبطة بها )لوحة .ةكريهفم درسنا قلق المراهقين بأنفاسهم وما إذا كان أي شخص قد أخبرهم من قبل أن لديهم رائحة ذلك،في العراق. باإلضافة إلى كربالء، سنة من المدارس الحكومية والخاصة في مدينة 15تم إجراء مسح رصد مقطعي على طالب المدارس الثانوية في سن المواد والطرق: ، piمدرسة. مقابلة مع استبيان منظم وأجريت جنبا إلى جنب مع قياس المعلمات الشفوية ) 44مراهق من 400العراق. تكونت العينة العشوائية من gi ،dmf.) كريهة حسب الدرجة الكلية ٪ وفقًا للسؤال األول. كانت نسبة انتشار رائحة الفم ال48.50كان انتشار رائحة الفم الكريهة المبلغ عنها ذاتيًا النتائج: والتي ذاتيًا،أن هناك انتشاًرا كبيًرا لرائحة الفم الكريهة المبلغ عنها أي ٪ بعدم إصابتهم برائحة الفم الكريهة. 13.5٪. بينما أفاد 86.5لالستبيان سنان وحالة اللثة بشكل كبير مع رائحة الفم ترتبط بالنمط االجتماعي واالقتصادي. أبلغ معظم المراهقين عن قلقهم من أنفاسهم. ارتبطت لوحة األ قد يكون االنتشار الكبير لرائحة الفم الكريهة المبلغ عنها ذاتيًا وفقًا لالستبيان بين الطالب بسبب تناول الثوم أو الطعام الكريهة المبلغ عنها ذاتيا. باإلضافة إلى أن طبقة البالك والتهاب اللثة وتسوس األسنان تسبب زيادة في مستوى مركب الفضة المتطاير مما يؤدي إلى زيادة رائحة الفم الحار، .الكريهة رائحة الفم ٪ من المراهقين في مدينة كربالء. تم العثور على 50رائحة الفم الكريهة المبلغ عنها ذاتيا هي حالة سائدة في حوالي : اتاالستنتاج .الكريهة للمرضى المبلغ عنها ذاتيًا مرتبطة بلويحة األسنان والتهاب اللثة وتسوس األسنان articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 54 research article effects of vitamin d deficiency on bone and root resorption post-orthodontic retention in rats asmaa murshed khamees 1*, dheaa h. al groosh 2, natheer h al-rawi 3 1. ph.d. student, department of orthodontic, college of dentistry, university of baghdad, iraq. 2. professor, department of orthodontics, college of dentistry, university of baghdad, iraq. 3. professor, department of oral and craniofacial health sciences, university of sharjah, uae. * correspondence email: d.al-groosh@codental.uobaghdad.edu.iq abstract: background: orthodontic therapy often causes external root resorption. serum vitamin d (vd) level is important for tooth mineralization and bone remodeling. this study aimed to test the impact of vitamin d (vd) supplements on bone and root remodeling in a vitamin d (vd) deficient rat model following orthodontic retention. methods and material: 30 male wistar rats were divided into three groups: a control group of 10 rats and two experimental groups of 10 rats, each with vitamin d deficiency (vdd) induced by a vd-free diet for 21 days. and a third group with vd supplement. all groups received active orthodontic treatment using a modified orthodontic appliance that applied 50 gm of force for 14 days to move the maxillary right first molar mesially, followed by seven days of retention and relapse. the vdd group received no intervention, while the vds group received 40,000 iu/kg of systemic vd3 by intramuscular injection on the first and fifteenth day of orthodontic treatment. histomorphometric analysis was performed to assess bone and cementum resorption and deposition. results: the vdd group exhibited a significant increase in bone and root resorption and decreased bone deposition and cementum deposition ratio. in addition, bone deposition and the ratio of cementum deposition were substantially greater in the vds group compared to the control group. conclusion: vdd may increase bone and root cementum resorption and decrease deposition after orthodontic retention, which may play a significant role in relapse after retention. before beginning orthodontic treatment, routine vd screening may be beneficial. keywords: vitamin d, orthodontic, bone, cementum. introduction root resorption is a process of root tissue removal that may occur in different areas alongside the root, that is laterally and/or around the apex, and it may be found with severe tissue loss (1). external root resorption is common during orthodontic treatment; however, it has no significant clinical consequences (2, 3) nor other health-related issues such as root fracture, periodontal illness, or early tooth loss (4). root resorption could be either a physiological or pathological, and the latter may be referred to as orthodontic treatment (5). orthodontic force enhances an inflammatory process that activates osteoclast cells, which cause the removal of bone and root tissues. this process is followed by a reparative process (1). in addition, root resorption could be associated with other anomalies such as hormonal deficiency and alveolar bone density (6, 7). vitamin d deficiency (vdd), a common hormonal deficiency problem, (8) increases serum parathyroid hormone, which results in progressive bone loss and mineralisation defects. epidemiologic studies showed that vdd was associated with low bone mineral density and fracture incidence (9, 10). vitamin d (vd) serum level is an essential parameter in root and bone remodeling (11). a correlation was observed received date: 25-12-2022 accepted date: 02-02-2023 published date: 15-06-2023 copyright: © 2023 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecomons.org/licenses/by/4.0/). https://doi.org/10.26477 /jbcd.v35i2.3403 mailto:d.al-groosh@codental.uobaghdad.edu.iq https://orcid.org/0000-0001-7120-8720 https://orcid.org/0000-0003-0052-7286 https://orcid.org/0000-0002-7483-6594 https://creativecomons.org/licenses/by/4.0/ https://creativecomons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3403 https://doi.org/10.26477/jbcd.v35i2.3403 j. bagh. coll. dent. vol. 35, no. 2. 2023 khamees and al groosh 55 between root resorption and vd receptor gene polymorphism (12). however, the relationship of vdd and root resorption was inconclusive, probably because of published data with short-term follow-up (13). in the resorption lacunae, fibroblast-like cells from the periodontal ligament invading these lacunae repair the resorbed cementum (14). the first histologic evidence of repair is the presence of a thin, uncalcified cementoid (14). these cells secrete noncollagenous matrix proteins, particularly bone sialoprotein and osteopontin, filling the cementoblasts to secrete collagen and form a thin cementoid repair matrix (14, 15). subsequently, hydroxyapatite crystals grow between collagen fibrils for mineralisation (16). the reparative cementum is a cellular intrinsic fibre type (14). in contrast, the recently deposited cementum appears as layers (thin layer of acellular cementum) in rats, which covered some of the resorption lacunae (17). this study aimed to assess the amount of bone and root remodeling after orthodontic retention in a vddenhanced rat model and to evaluate the effect of vd supplements on vd-deficient rats. materials and methods 1. animal preparation the study was approved by the scientific research and ethics committee at the department of orthodontics, college of dentistry/university of baghdad (issue no: 177, date 16/1/2020). all experimental procedures were performed in iraqi center of cancer and medical genetics research. male wistar rats (n = 30) aged 8–10 weeks and weighing 220–300 g were used in this study. firstly, the rats were acclimatised for one week before vd induction and subjected to 12/12 h of dark/light cycles at 21 °c ± 2 °c with a relative humidity of 50% ± 10%. rats were fed a laboratory standard diet and given water ad libitum (18). all the rats followed the same principle. they were weighed. the tail of the rats was coloured (every one special colour). blood serum was collected by aspiration using a 5 ml sterile syringe (disposable syringe with a needle, 1 ml luer slip, jiangsu jichun medical devices, china) after anesthetising with chloroform (alpha chemika, india). serum vd was investigated and assessed using the vd antibody protein elisa kit following the manufacturer’s instructions (mybiosource, usa). afterward, the rats were divided into two groups. the control group without intervention, and the experiment group in which the rats were fed a vd-free diet (casein-free vd, bio-serv, usa) for 21 days (19, 20). after 21 days, serum vd was re-investigated, and rats suffering from vdd were divided into three groups: 1. the control group. 2. the vdd group continues deficiency during the treatment period. 3. the vdd group received vitamin d supplementation (vds) by intramuscular injection on days 1 and 15. however, these doses elevated the vd serum level the same as the control group during orthodontic treatment. 2. orthodontic treatment stages the rats were anesthetised after being weighed using intramuscular injection of ketamine (87 mg/kg; ketamine 10%, alfasan, woerden, holland) and xylazine muscle relaxant (10 mg/kg; xyl-m2 injectable solution 25 ml, vmd, arendonk, belgium) at a 2:1 ratio(21), that is in thigh muscle based on the animal housing guidelines in ccmgr. this process was applied in all orthodontic stages. interproximal spaces were measured between the distal surface of the first molar and the mesial surface of the second molar by using an interproximal vernier (feeler gauge, roshtoo80, japan), and this process was repeated two times by one operator (22). an orthodontic ligature wire (0.010″, truforce stainless steel, ortho technology, usa) was inserted interdentally between the 1st and 2nd right maxillary molars (23) (unilateral orthodontic appliances were bonded, j. bagh. coll. dent. vol. 35, no. 2. 2023 khamees and al groosh 56 and the left molar serves as the control side) (24). then, the first maxillary molar was ligated, and a hook, nickel–titanium closed-coil spring was formed (dentaurum, rematitan® lite tension spring, dentaurum). this hook was inserted, and the other end was attached to the hook formed on maxillary central incisors using a ligature wire (0.012 kobayashi, klardent, sweden) after being etched with acid etch gel (37% microdont, brazil). the force delivered with 50 ± 5 gm was adjusted using a digital hand-held force gauge (sr-1 kg gray digital hanging scale, american weigh scales, ga, usa) to move the 1st molar mesially. bonding adhesive was applied (3m espe, adper, single bond 2, usa), and composite filling materials (3m espe, filtek, z350 xt, universal restoration, usa) were adapted and cured according to the manufacturer’s instructions (fig. 1a) (21). vitamin d3 (cholecalciferol 300000 i.u.\1 ml, pisa, italy) of 40,000 iu/kg was administrated slowly in left thigh muscle on day one and day 15 for the vdd group (25). on day 15, the orthodontic spring was removed; spaces were measured, and a retainer was inserted for seven days. afterward, relapse was allowed for another seven days (fig. 1 b) (26). then, an overdose of anaesthesia was given, and the final space was measured. figure 1: a; orthodontic appliance bonding, b; relapse 3. histological preparation all rats were sacrificed under an overdose of anaesthesia, and the maxilla was placed in 10% natural buffered formalin solution (formaldehyde, scharlab s.l., spain) for 24 h. the sample was rinsed for 21 days in 10% edta solution (ph = 7; bdh chemicals ltd. poole, england), and the solution was continuously changed (21, 27). after decalcification, half of the maxilla (28) underwent dehydration (29) and then embedded in paraffin wax (leica biosystems, richmond, usa) to obtain longitudinal sections of teeth with the adjacent tissue. two sections of 5 µm thickness, including the mesial root of the maxillary first molar, were stained using haematoxylin and eosin stain (h&e, leica biosystems, richmond, usa). the pressure and tension sides were photographed under a light microscope (optika, microscopes, italy) with 4×,10× and 40× objective lenses (28) equipped with a photomicroscope (olympus, tokyo, japan). for inter-examiner calibration, the section was randomly selected two times and examined by the same histopathologist under a blind test (30). the bone area was sectioned to rectangles alongside the mesial root of the maxillary right molar, and bone resorption and formation in pressure and tension sides were calculated using image j processing program (image j.exe, loci, university of wisconsin) that was developed at the national institutes of health (31, 32). the resorbed and newly deposited radicular cementum was detected and measured under a light microscope similarly as bone. the resorption area of cementum appears as lacunae, and the severity of root resorption was evaluated on the basis of the semiquantitative scale, in which the number, depth and area of each resorption lacuna were calculated (fig. 2 a) (17). j. bagh. coll. dent. vol. 35, no. 2. 2023 khamees and al groosh 57 the measurement of the level of lacuna repair in cementum was dependent on the grading system, and the thickness of the repair cementum was measured in micrometre using a line as the perpendicular distance from the deepest area in the lacuna until the outer surface of the deposited layer. the image above analysis was used for this purpose (fig. 2 b) (33). figure 2: a, resorbed cementum (rc) represented in marked rectangular, white arrows show the thickness of resorption. b, recent deposit cementum (rc) represented in marked rectangular, white arrow shows the thickness of deposit cementum. statistical analysis the collected data were statistically evaluated by using statistical package for social sciences (ibm® spss® version 25). the shapiro–wilk test was used to assess the normality of data. anova and games– howell tests were used to compare the bone and cementum (resorption and deposition). results in the vdd group, data revealed a significant decrease in bone formation and an increase in bone resorption. however, bone resorption and formation were comparable between the vds group and the control group (table 1). table (1): comparison between the bone resorption and deposition among the control, vdd and vds groups using anova and games-howell tests. side group descriptive statistics comparison no mean (µm2) sd (µm2) f-test p-value groups p-value bone resorption control 10 173.5 7.84 112.2 0.000[s]* control vdd 0.000 [s]* vdd 10 261 24.24 vds 0.091[ns] vds 10 164 10.75 vdd vds 0.000 [s]* bone deposition control 10 199.5 6.85 171.4 0.000[s]* control vdd 0.000 [s]* vdd 10 145.5 6.85 vds 0.773[ns] vds 10 202 9.19 vdd vds 0.000 [s]* sd: standard deviation; ns: non-significant; s: significant at p<0.05. a b j. bagh. coll. dent. vol. 35, no. 2. 2023 khamees and al groosh 58 the pressure side data revealed that the alveolar bone surface was irregular, with incomplete mineralisation and few resorption cavities (figs. 3a and b). both the control and vds groups experienced the same outcome. in the vdd group, however, the resorption cavity expanded (fig. 3 c). the tension side of the mesial root in control and vds groups exhibited a tension periodontal ligament with a distinct reversal line between the basal and new bone (figs. 4 d, e). in contrast, the tension side of the mesial root in the vdd group exhibited narrow new bone apposition that was separated from the basal bone by a reversal line (fig. 4 f). figure 3: pressure side area of the mesial root of the upper maxillary first molar. pdl: periodontal ligament, yellow arrow: resorption cavities, (a): control; (b): vdd; (c): vds group (h &e; 10x). figure 4: tension side area of the mesial root of the upper maxillary first molar. tension periodontal ligament(tpdl); new bone (nb); reversal line (arrows); basal bone (bb). control (d); vdd (e), vds (f) groups. (h &e; 10x). similar to bone reaction, root resorption and cementum deposition were significantly increased in the vdd group compared to the control and vds groups. table 2 shows no statistically significant difference between the control and vds groups. consequently, the ratio of cementum deposition to cementum resorption was decreased in the vdd group primarily (table 3). table 2: comparison between cementum resorption and deposition among the control, vdd and vds groups using anova and games-howell tests. side group descriptive statistics comparison no mean(µm2) sd(µm2) f-test p-value groups p-value cementum resorption control 10 15 5.27 204.7 0.000[s]* control vdd 0.000 [s]* vdd 10 63 9.49 vds 0.052 [ns] vds 10 10.1 2.73 vdd vds 0.000 [s]* cementum deposition control 10 6.1 1.10 26.01 0.000[s]* control vdd 0.001 [s]* vdd 10 20 8.16 vds 0.765 [ns] vds 10 6.6 1.96 vdd vds 0.001 [s]* sd: standard deviation; ns: non-significant; s, significant at p< 0.05. a b c e d f a b c e d f j. bagh. coll. dent. vol. 35, no. 2. 2023 khamees and al groosh 59 table 3: percentage of cementum deposition to cementum resorption with the same group groups sample no mean/ cr mean/cd cd/cr % control 10 15 6.1 46 % vdd 10 63 20 31.6% vds 10 10.1 6.6 68.4% cr: cementum resorption; cd: cementum deposition discussion vitamin d deficiency is considered a common health-related problem that is faced by people of all ages worldwide (34, 35). it may be associated with low bone mineral density and bone activity (9). in orthodontics, retention is an important phase of the treatment (36). however, the prevalence of relapse was reported, and only 30%–50% of treated patients maintained the initial acquired satisfactory alignment after 10 years. in addition, only 10% of treated patients maintained a satisfactory alignment after 20 years (37). although the mechanism of orthodontic relapse remains unknown (38), bone turnover may influence the relapse (39). previous research has used the local administration of different medications or biologicals to decrease the relapse following active orthodontic treatment (21, 40–42). however, arqub et al. (2021) reported that local administration may be associated with a short half-life of the agents and may require multiple administration. therefore, this study adopted the systemic administration of vd (43). the data revealed a decrease in bone resorption and an increase in bone deposition (bone synthesis) in the control and vds groups. the metabolites of 1α,25-hydroxylated stimulate the expression of osteoblast signature genes, including receptor activators of nuclear factor kappa-b ligand (rankl) and vitamin d receptors (vdr) (44). the activation of vdr increases the expression level of receptor activator of nuclear factor kappa (rank) on the osteoclast-progenitor cells surface, which stimulates osteoclastogenesis and bone resorption by binding rank to rankl. the expression of vdr on the osteoblast cell represents an activation pathway of bone resorption (45). in addition, vd plays a role in skeleton mineralisation, which has an anabolic activity ingredient that plays an important role in bone synthesis stimulation (46). this finding is consistent with the result of kale et al. (2004), who found that the local administration of 1,25dihydroxy cholecalciferol increased and facilitated tooth movement by regulating bone deposition and resorption (40). moreover, kawakami and takano-yamamoto (2004) reported that the stability of teeth position was improved after orthodontic movement and local administration of vd (47). furthermore, many authors suggested that vd improves bone health and mineral metabolism (48, 49, 50). the data displayed a significant decrease in root resorption with vds and an increase in the vdd group. during orthodontic treatment, the generation of proinflammatory mediators under orthodontic forces, such as prostaglandins and leukotrienes, causes tooth movement (51) and cementum loss, which may lead to root resorption (52). this finding is consistent with the results of seifi et al. (2013), who found that vdd during orthodontic treatment may play a key role in the pathophysiological process of root resorption (53). in addition, booij vrieling et al. (2010) reported that active vd signals induce pathophysiological root resorption in cats (54). however, the abovementioned results were contrary to that of tehranchi et al. (2017), who demonstrated no significant correlation between the vd serum level and external apical root resorption development j. bagh. coll. dent. vol. 35, no. 2. 2023 khamees and al groosh 60 (55). moreover, this result was inconsistent with that of al-attar and abid (2022), who demonstrated a nonsignificant correlation between root resorption and vd serum level after the first three months of orthodontic treatment (13). a different method of root resorption assessment could be used, as the latter used a periapical radiograph with a digital sensor as opposed to the gold standard for histological investigation in the current study. considering that root resorption is common, resorption lacunae were fully or partially repaired with new cementum (14). this acellular tissue in rats contrasts with the cellular intrinsic fibre cementum reported in humans (16, 17). the results show a significant increase in cementum deposition in vdd in comparison with other groups. in contrast, the ratio of cementum deposition to resorption cavities decreases in vdd in comparison with other groups. this result is consistent with the process of metabolic activity of vd by the indirect role of vd in the stimulation of osteoclastogenesis through regulating some secondary messengers for expression and interactions amongst inflammatory cells, cytokines, enzymes and clast cells (56), which is consistent with the suggestion that vd deficiency and dietary vd redundancy have an indirect role in the pathophysiology of the regeneration of common permanent tooth in cats (54). conclusion after orthodontic retention, vitamin d deficiency may be elevated in bone and cementum resorption and decreased in bone deposition. nonetheless, correction of vdd in rats is associated with bone and cementum remodeling, which may significantly reduce relapse after retention. therefore, patients who are planning orthodontic treatment should undergo vd screening, and the vd serum level should be corrected before treatment. conflict of interest: none declared. references 1. andreasen jo, andreasen fm. textbook and color atlas of traumatic injuries to the teeth, 3rd edn. munksgaard publishers, copenhagen.1993. doi:10.25241 2. chan ek, darendeliler ma. exploring the third dimension in root resorption. orthod craniofac res. 2004; 7:64-70. 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(crossref) تقويم األسنان في الفئران تثبيت العظام والجذور بعد تأكل نقص فيتامين )د( على ر العنوان: تاثي 2, ضياء حسين الكروش 1الباحثون: اسماء مرشد خميس :الخالصة تاكل الجذرالخارجي أثناء عالج تقويم األسنان ، فقد اقترح أن مستوى فيتامين )د( في المصل ضروري المتصاص وبناء الخلفية: ليس من غير المألوف ويم االسنان في األنسجة الصلبة مثل العظام واألسنان، وقد هدفت هذه الدراسة إلى تقييم نسبة تكوين العظام والجذور فيما بعد فترة التثبيت من عالج تق العظام والجذور. ان المصابة بنقص فيتامين )د( وتقييم تأثير مكمالت فيتامين )د( على إعادة تكويننموذج الفئر فئران ومجموعتين تجريبية )كل 10إلى ثالث مجموعات. مجموعة التحكم wasterالمواد وطرق العمل: تم تقسيم الجرذان البالغة ثالثون ذكر نوع يوًما. خضعت جميع المجموعات 21فئران( المصابة بنقص فيتامين )د( الناجم عن اطعام الفئران غذاء مخصص خالي من فيتامين )د( لمدة 10واحدة 14جم من القوة لتحريك األضراس األولى اليمنى للفك العلوي األيمن لمدة 50ه لتطبيق لعالج لتقويم األسنان باستخدام جهاز تقويم أسنان معدل تم تركيب وحدة دولية / كجم 40000أيام. مجموعة نقص فيتامين )د( دون تداخل ، بينما تلقت المجموعة المكملة بفيتامين )د( 7أيام ، واالنتكاس 7يوًما ، والتثبيت لي في اليوم األول والخامس عشر من فترة العالج التقويمي. تم إجراء فحص االنسجة لتقييم تاكل ووبناء العظام من فيتامين )د( عن طريق الحقن العض والمالط. كانت نسبة تكوين النتائج: كان هناك زيادة معنوية في تاكل العظام والجذور وانخفاض بناء العظام ونسبة بناء المالط في مجموعة نقص فيتامين )د(. بينما ظام والمالط أعلى بكثير في المجموعة المكملة بفيتامين )د( وكذلك في مجموعة التحكم. الع ا مهًما في : قد يؤدي نقص فيتامين )د( إلى ارتفاع تاكل العظم والجذر، وكذلك تقليل بناء العظم والجذربعد فترة تثبيت التقويم التي قد تلعب دورً االستنتاج ت. قد يكون الفحص الروتيني لفيتامين )د( مفيدًا قبل البدء في عالج تقويم األسنان.زيادة االنتكاس بعد فترة التثبي https://doi.org/10.1111/j.1600-0722.2009.00707.x https://doi.org/10.1016/s0003-9969(03)00201-2 ibtehal final.doc j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 74 immunohistochemical expression of hoxa1, and ki-67 proteins of oral squamous cell carcinoma ibtehal qhtan al-etbi, b.d.s., m.sc. (1) riyadh othman al-kaisi, b.d.s., m.sc., ph.d. (2) abstract background: oral squamous cell carcinoma (oscc) is the most prevalent malignant neoplasm of the oral cavity and constitutes a major health problem in developing. in the last 30 years, the 5-year survival rate of patients with oral scc has not improved despite advance in diagnostic techniques. to improve early diagnosis for this deadly disease, new biological markers are needed. hox genes encode homeodomain-containing transcription factors involved in the regulation of cellular proliferation and differentiation during embryogenesis. hox gene expression has been described in several adult tissues, where they performed important roles in maintaining homeostasis. few studies have suggested that hoxa1 plays a role in tumorigenesis. besides being overexpressed in several tumors, hoxa1 influences numerous cellular processes including proliferation, apoptosis and epithelialmesenchymal transition (emt), and hoxa1 overexpression is sufficient for malignant transformation ofnontumorigenic epithelial cells. ki-67 is a specific marker of proliferation and the expression of which is strictly associated with cell proliferation and is widely used in pathology as a proliferation marker to measure the growth fraction of cells in human tumors.the aims of this study were to evaluate the immunohistochemical expression of hoxa1 & ki-67 in oscc & to correlate the expression of the studied markers with the clinicopathological findings and with each other materials and methods: thirty formalin-fixed, paraffinembedded tissue blocks of oral squamous cell carcinoma were included in this study. h&e stain was done for each block for reassessment of histological examination. an immunohistochimical stain was performed using anti hoxa1 and anti ki-67 poly clonal antibodies. results:the expression of hoxa1 and ki-67were positive in all oral squamous cell carcinoma cases & in all layers (100%), while the expression was restricted to the basal and supra basal layer in normal oral mucosa. statistically non-significant correlation observed between each marker with clinico-pathological parameters. while a statistically significant association was found between the expressions of two markers, (p-value= 0.027). conclusion: the statistically significant association observed between expressions of hoxa1 with the specific marker of proliferation ki-67. this suggested important role in oral scc development and progression. keywords: oscc, hoxa1, ki-67. (j bagh coll dentistry 2014; 26(2): 74-78). الخالصة :الخلفیة الطبیة التشخیصیة إال إن وبالرغم من تطور التقنیات . تجویف الفمي ویمثل المشكلة الرئیسیة المؤدیة للوفاة في بلدان العالم الثالثالسرطان الخالیا الحرشفیة ھو السرطان السائد في إن الكشف المبكر لسرطان الخالیا الحرشفیة الفموي مھم جدا للحد من خطورتھ . مستوى سنوات البقاء الخمسة المعتمدة في علم األورام لم یتطور بشكل مفید في السنوات الثالثین االخیرة المحفزة للنمو والتمایز اثناء النمو homeoboxالتابعة لجینات hoxوھو احد افراد عائلة جین hoxa1ولذلك تم التركیز على إیجاد واسمات بیولوجیة جدیدة ومنھا جین وقد اثبتت دراسات حدیثة دوره المسرطنالفعال في العدید من االمراض السرطانیة حیث یظھر بشكل غیر . الجنیني والتكوین العضوي وقد یظھر في األنسجة البالغة عند الحاجة ایضا مبكر لسرطان ھو مؤشر التكاثر الرئیسي في النواة وھو المساعد في كشف وجود اي انقسامات في األنسجة وبالتالي فلھ فائدة عظیمة في التنبؤ والكشف ال ki-67 .في األنسجةمتوازن وكذلك ربط ظھور كل منھما مع . ki-67 لجین بمؤشر التكاثرفي السرطان الحرشفي للفم وربط ظھور ا hoxa1 تھدف الدراسة الحالیة الى التحري والتحقق من ظھور جین. الفم . المعطیات السریریة المرضیة لسرطان الفم الحرشفي مع ین والمطمورة بشتضمنت ھذه الدراسة ثالثین عینة استرجاعیة ألشخاص مصابین بسرطان الفم الحرشفي والتي استخرجت من المقاطع النسیجیة المثبتة بالفورمال: المواد والطرق بعد لك اجریت الصبغات الكیمیائیة النسیجیة المناعیة باستخدام . البارافین وجرى صبغ كل عینة بصبغتي الھیماتوكسلین واالیوسین إلعادة تقییمھا لغرض الفحص النسیجي المرضي . على شرائح نسیجیة دقیقة من العینات ki-67 ومضاد hoxa1 مضاد اما نسبة إصابة الذكور %) . 70( ت ھذا السرطان تقع في االعمار التي تفوق الخمسین عامًا وأن معظم تلك الحاالت تركزت في الذكور وبنسبة أظھرت الدراسة أن اكثر حاال: النتائج %) 73,3(ت سریریا بشكل اورا م ومعظمھا ظھر%) 36,7(كذلك اظھرت الدراسة ان معظم الحاالت كانت في اللسان ). 1:2:(الى االناث فقد اظھرت ھذه الدراسة إلى انھا تساوي من النوع الواضح التمایز لسرطان الفم %) 40,0(من الحاالت السرطانیة ھي من النوع المتوسط التمایز و%) 43,3( اما الفحوصات النسیجیة المرضیة لھذه الدراسة فقد أظھرت ان . كان ایجابیًا في الطبقة السفلى فقط من النسیج المخاطي الفموي الطبیعي، بینما كان ایجابیًا في كل ki-67ومؤشر التكاثر hoxa1 اظھرت ھذه الدراسة ایضًا ان تعبیر. الحرشفي hoxa1 مما یدل على الدور المھم لجین ki-67 ومؤشر التكاثر hoxa1 كذلك اظھرت ھذه الدراسة وجود عالقة واضحة بین ظھور جین. طبقات النسیج الحرشفي لسرطان الفم واخیرا بینت ھذه الدراسة عدم وجود ایة عالقة بین العاملین السابقین والمتغیرات السریریة المرضیة مسرطن وذلك بواسطة تحفیز انقسام الخالیا وبالتالي النمو السرطاني الفمويكعامل .االخرى المصاحبة لسرطان الفم الحرشفي في انقسام الخالیا والنمو السرطاني لذلك تقترح ھذه الدراسة اجراء دراسات hoxa1 داللة على دور جین ki-67 مع مؤشر التكاثر hoxa1 تالزم وجود جین: االستنتاجات . او مع مؤشر تكاثر اخر ki-67 مع مؤشر التكاثر hox او عضو اخر لجین hoxa1 جدیدة بعینات اكثر عددا لمعرفھ الدور الحقیقي لجین introduction squamous cell carcinoma (scc) accounts to more than 90% of malignant tumors of the oral cavity and oropharynx. it is often related to considerable mortality and morbidity rates, and presents a variable etiology related to alcohol and tobacco abuse associated with genetic factors (1,2). (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2) professor, department of oral diagnosis, college of dentistry, university of baghdad. the homeobox genes, is a master regulators of morphogenesis and cell differentiation during embryogenesis, have emerged as potential candidates to be also involved with carcinogenesis. this important family of genes codes regulatory proteins that act as transcriptional factors controlling the development of several tissues including orofacial tissue (3,4). hoxa1 is a member of hox genes family which issubgroup of homeobox genes have important role in oscc development and j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 75 progression. ki-67 is a cell cycle associated human nuclear protein present in perichromosomal region (5). the estimated half-life of ki-67antigen is 6090 minutes, and the ki-67antigen starts to be expressed in s phase, progressively increasing through s and g2 phase and reaching a plateau at mitosis. after cell division, the cell return to g1with a stock of ki-67antigen, whose level decreases rapidly during this phase (6,7). this study aimed to: • evaluate the immunohistochemical expression of hoxa1 and ki-67 markers in oral squamous cell carcinoma. • correlate the expression of either marker with each other and with the clinico-pathological parameters (age, sex, tumor site, clinical presentation, and histopathological grades) of oscc. materials and methods a retrospective study was performed on thirty formalinfixed paraffin embedded blocks of osccwere collected from the archives of oral pathology laboratory, college of dentistry, baghdad university, al-kadhimiya teaching hospital, and al-shaheed ghazi hospital/ medical city / baghdad from (2010-2013).the diagnosis of each case was confirmed by examining the hematoxylin and eosin (h&e) sections by two experienced pathologists. four micrometer thick sections were cut and mounted on positively charged slides and stained immunohistochemically with monoclonal antibodies using anti hoxa1 and anti ki67polyclonal antibodies (abcam uk). abcam expose mouse and rabbit hrp/dab immunohistochemical detection kit (catalog no. ab80436, cambridge, uk) was used. results clinicopathological findings of oscc cases were designed as follows: most of the cases 21 (70%) aged were above 50 years and the majority of the cases were males 21 (70 %). the most common site was the tongue 11 cases (36.7%) and most of the cases were presented as mass22 cases (73.3%). histopathological examination showed that 13 cases of oscc (43.3%) were moderately differentiated, followed by 12 cases (40%) well differentiated and 5 cases (16.7%) were poorly differentiatedas shown in table (1). immunohistochemical staining with hoxa1primary antibody showed that hoxa1 expression was positive in all examined oscc specimens andwas observed as a nuclear stain restricted to the basal and suprabasal layers in healthy mucosae figures (1), whereas a broad positivity with variable distribution and intensity was found in the oscc samples as shown in figures (2,3). score +1 was found in 26.6% (8 cases), score +2 and score +3 both found in 36.7% (11 cases) table(2) . immunohistochemical staining with ki-67 primary antibody showed that ki-67 expression was positive in all examined oscc specimens. ki-67immunostaining as shown in figure (4) was observed as a nuclear stain restricted to the basal layer in healthy mucosae, whereas a broad positivity with variable distribution and intensity was found in the oscc samples as shown in figures (5,6). half of the cases (15 cases) were moderately proliferated score (++) and other (15 cases) were highly proliferated score (+++). regarding correlation of two markers with the clinicopathological findings of oscc cases reveal that there was no significant correlation of these two markerswith the clinicopathological findings(age, sex, tumor site, clinical presentation and histopathological grades). concerning correlation between hoxa1 and ki-67 expression score table (3), result of present study revealed statistically significant positive correlation with p value = 0.027. figure 1: hoxa1 expression in normal oral mucosa (10x). figure 2: positive expression of hoxa1 in well differentiated oscc (10x). j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 76 table 1: clinico-pathological characteristics of 30 oscc cases percent % frequency age 70 21 >50 30 9 24-50 sex 70 21 male 30 9 female tumor site 36.7 11 tongue 23.2 7 maxilla 20 6 mandibul 6.7 2 floor of mouth 6.7 2 buccal mucosa 6.7 2 lip histological grading 40 12 well 43.3 13 moderate 16.7 5 poor clinical presentation 73.3 22 mass 20 6 ulcer 6.7 2 white lesion table 2: hoxa1 expression in 30 cases of oscc hoxa1 score frequency percent score 1+ 8 26.6% score 2+ 11 36.7% score 3+ 11 36.7% total 30 100% figure 3: positive expression of hoxa1 in moderate differentiated oscc (10x). table 3: correlation between hoxa1and ki-67expression in oscc. hoxa1 score ki-67 score total x2 sig. ++ +++ n % 1+ 5 3 8 26.6 7.227 0.027 (s) 2+ 8 3 11 36.7 3+ 2 9 11 36.7 total 15 15 30 100 figure 4: ki-67 expression in normal oral mucosa (10x). figure 5: positive expression of ki-67 in well differentiated oscc (10x). figure 6: positive expression of ki-67 in moderately differentiated oscc (10x). discussion concerning the epidemiological parameters, including age, sex, site, clinical presentation, studies showed variable results; these inconsistent findings among different studies could be credit with the fact that the current study and some of the others are not an epidemiological type of studies, therefore the limited number and the random selection of the cases according to what is available preclude for definitive clinical findings. j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 77 assessment of hoxa1 immunohistochemistry immunoreactivity for hoxa1was observed as nuclear stain. positive hoxa1 expression was observed in all the studied cases of oscc this finding was agreed with previous study (8) which was similar to this study.cytoplasmic staining was also observed in some cases with nuclear stain, this explain by interaction between hoxa1 with numerous protein and transcription factors which was present primarily in the cytoplasm and involved in critical developmental process and then upon activation translocate to the nucleus to perform their function this interaction improved by study (9). in normal oral mucosa, immuno staining was restricted to the basal and suprabasal layers only due to the fact that squamous epithelium keeps a continuous physiological regeneration in normal conditions, while broad positivity with variable distribution in oscc sample, the intensity of hoxa1expression was found beyond basal localization suggests that a correlation between hoxa1 expression and tumor progression may exist. few studies(8)concerned hoxa1expression in oscc which may be due to the fact that recently more attention has been paid to study this genes andto our knowledgethis study is the first study in iraq which demonstrates the hoxa1 expression in oscc particularly or other cancer. however, many other studies (9-12) show expression of various members of hox gene family in oscc. furthermore, aberrant expression of numerous hox genes has been reported in various malignancies such as hematological malignancies (10) and variety of other solid tumors (13-15) regarding correlation of hoxa1 expression with clinic-pathological parameters; this study revealed that hoxa1 expression was not correlated with age, sex, clinical presentation and location of tumor. this finding was in agreement with previous study concerning oscc (8), a nonsignificant correlation also was found concerning hoxa1 expression and different tumor grades, opposite results were found by previous study (8) assessment of ki-67 immunohistochemistry: cell proliferation is a biological process of vital importance and this control is lost in cancer (16). therefore, the knowledge of cellular proteins that control cell proliferation is essential for understanding tumor biology (17,18). ki-67 antigen is a specific marker of proliferating cells (19).the ihc reactivity for nf kb p65 was evaluated on the basis of presence or absence of brown nuclear and cytoplasmic staining (20) this study showed positive nuclear staining of ki-67 antigen in all oscc cases and in all layers, whereas in normal oral mucosa positive ki-67 immunoreactivity was seen in the basal cell layer only (5). in addition, half of the positive cases showed high expression score and other half showed moderate expression score. regarding the correlation of ki-67 positive expression with age the results of the present study showed statistically non-significant correlation in ki-67 expression between the two age groups. this finding agreed with previous study (21) and disagreed with other (22). regarding the sex and sit of tumor there was statistically 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oral pathol oral radiol endod 2007; 103, 30-5. zaid.doc j bagh college dentistry vol. 27(2), june 2015 the effect of pedodontics, orthodontics and preventive dentistry173 the effect of nutritional status on arch width and length of primary teeth among five years old kindergarten children zaid saadi hasan ahmed, b.d.s., m.sc., ph.d. (1) ban sahib diab, b.d.s., m.sc., ph.d. (2) abstract background: in human life, malnutrition may adversely affect various aspects of growth at different stages of life. teeth are particularly sensitive to malnutrition. malnutrition may affect odontometeric measurement involving arch width and length of primary dentition. the aim of this study is to estimate the effect of nutrition on arch width and length dimension measurements among children aged 5 years old. material and methods: this study was conducted among malnourished group in comparison to well-nourished group matching with age and gender. the present study included 158 children aged 5 years (78 malnourished and 80 wellnourished). the assessment of nutritional status was done by using three nutritional indicators, namely height-for-age, weight-for-age and weight-for-height. odontometeric measurements including two different orientations. for both upper and lower study models, photographs were taken using special photographic apparatus for each child, and the data were then analyzed using special computer software. for primary dentitions, two linear measurements (intercanine distance and inter-molar distance) were utilized, representing arch measurements. results: as for primary dentitions, all means value of maxillary and mandible arch width and length were lower among malnourished group than well-nourished group with statistically highly significant except for both inter-canine distance of maxillary and mandibular, maxillary anterior arch length and mandibular molar vertical length. conclusion: malnutrition effect on minimize the odontometric measurements (dental arch width, dental arch length) among children aged 5 years. key words: dental arch width, dental arch length and children. (j bagh coll dentistry 2015; 27(2):173-177). introduction nutrition is one of the essential needs of human beings and it provides human body with energy and essential nutrients necessary for adequate physical and social activities, and maintains or enhances its healthy state (1). malnutrition can be defined as a “pathological state resulting from absolute or relative deficiency or excess of one or more of the essential nutrients" (2). still malnutrition is one of the global highest priority health issues not only as its effects are so widespread and long lasting but also because it can be eradicated (3,4) . the dental plaster models of a patient's dentition are necessary in dental measurement (5). recently, dentistry looks to digital archive and tend to be paperless patient information systems. especially when many methods have been used to determine and to analyze dental plaster casts (6). this is one of the reasons to use photograph technique to measure dimension of dental cast in this study. researchers demonstrated that protein-energy malnutrition is associated with decrease jaw height (7), as well as the reduced of the maxilla and mandible widths are also adversely influenced by malnutrition (8). (1) lecturer. department of pedodontic and preventive dentistry college of dentistry, university of baghdad (2) assist. professor. department of pedodontic and preventive dentistry college of dentistry, university of baghdad in general, several anthropometric studies found a significant adverse effect of malnutrition on the growth and development of facial bones of children, as well on the development of skeletal muscles and organs (7-9). this study represents the pioneering aspect. its importance in terms of providing greater visibility to the harmful effects of malnutrition on oral pictures and change dental morphometric. materials and methods the sample collection the sample of this study involved two age groups 5 years with different nutritional status. age was recorded according to the last birthday (10). out of 240 children who were initially examined, only 158 children (78 malnourished and 80 well-nourished) were candidates selected for the morphometeric analysis in this study. the pupil should not suffer from any serious systemic disease or health problem as indicated by the schools’ records, all primary teeth were erupted with no permanent tooth, and the children should be free from: congenital abnormalities, congenital missing teeth, supernumerary or abnormal shape tooth and clinical signs of attrition and enamel defect. j bagh college dentistry vol. 27(2), june 2015 the effect of pedodontics, orthodontics and preventive dentistry174 instruments and supplies plane mouth dental mirror (no. 4), sickle shape explorer (no.00), bathroom scale for recording weight, the height of the individuals was measured by using the ordinary height measuring tape, electric vibrator (quale dental), dental vernier (dentaurum 0.05 mm (042-751) germany, digital camera (6 mega pixels) sony, photographic apparatus (figure 1), software auto cad, 2006, product version z.54.10. classification of nutritional status of children aged 5 years three indicators of the subjects’ nutritional status were used to assess the nutritional status of each person in this study and they involve: height for age (h.f.a), weight for age (w.f.a) and weight for height (w.f.h). based on each nutritional status indicator, the cut off point used z-score below -2 sd and between median to +1 to classify malnutrition and well-nourished conditions respectively. and the person was classified as either malnourished or wellnourished depending on these three indicators. each z-score was considered in terms of standard deviation. the z score = individual value — median of reference population standard deviation of the reference population morphometric measurements ß photographic technique and cast orientation the three-dimension analysis of crown orientation was achieved by considering the three rotational axes of pitch, roll and yaw (11,12). one capture is sufficient for dental arch measurements. before image acquisition, the cast should be oriented until incisal surfaces or occlusal surfaces of specific dental segment are orthogonal to the optical axis of the camera for each captures. this procedure was performed by putting the dental cast in surveyor base, and the cusp tips of specific segment teeth were reflected by the highest points. the next step of orientation would be restrained by balancing the movements in the three axes (x, y and z)(define above). for each arch, four image captures were taken to one cast occlusal surfaces orientations of whole arch. this photograph capture view of cast was produced as: occlusal surfaces of whole arch view were standardized by overlapping of the two cross lines (lines a and b) (where line a should overlap along the median palatal raphe of cast (median palatal line mpl) for the maxilla. in addition, the mirror image of mpl was transferred to the mandibular cast, and line b should overlap to transverse line that was tangent to the distal edge of the two second molars(namely right and left) for maxilla and mandible respectively). a reference metric system: prepare a metric scale in position parallel to and at the same level of the incisal and /or occlusal surface of cast (for each capture). by means of this metric scale, the calibration of each image dimension could be prepared. it was used to give a real metric value of the cast measurement by obtaining hypothetical factory and multiplying it with an initial measurement value of the photograph cast. final real (actual) value = hypothetical factor x initial measurement value ß taking dental cast captures after identifying landmark and orientation of each dental cast, the dental cast was placed on the portable part of surveyor and oriented in an ideal way (cusps heights were not used to orient the cast segment). before taking a picture (in order to calibrate the image through suitable software), it is necessary to set a reference millimetric scale in correspondence to the occlusal surface of the tooth. ß measurement of dental cast measurements were made directly on upper and lower dental casts by photographic technique through photographic apparatus which provides a constant distance between digital camera and occlusal teeth surfaces through the plastic plate for standardization. each set of dental casts were measured to the nearest 0.001 mm. dental arch width o i n t e r c a n i n e d i s t a n c e ( i c d ) : the linear distance from the right to the left canine at the cusp tip (13, 14). o i n t e r m o l a r d i s t a n c e a t d i s t o b u c c a l c u s p t i p s ( i m d a t d b c t ) : the linear distance between the disto-buccal cusp tip of the right and left second deciduous molar (13,14). dental arch length o canine vertical distance (c-vd): the vertical distance from the incisal point to the inter-canine distance at the cusp tips (14,15). o molar –vertical distance at disto-buccal cusp tip (m-vd at dbct): the vertical distance from the incisal point perpendicular to the inter-molar distance at the disto-buccal cusp tip (14-16). all data analyses were performed using the spss statistical software programme (version 10 for windows, spss). the confidence level was accepted at the level of 5%. *index point is that point formed by crossing of two line (a,b), and it mark on the translucent horizontal plate to standardized the cast segment for capture, as it represents the point through which optical axis of camera pass. j bagh college dentistry vol. 27(2), june 2015 the effect of pedodontics, orthodontics and preventive dentistry175 fig. 1: photographic apparatus (designed by hasan in 2010 (17)) results the maxillary and mandibular dental arch width for malnourished group and well-nourished among children aged 5 years are shown in table (1). concerning inter canine distance, the mean value of maxillary inter canine distance was found to be lower among malnourished group (29.133 ±0.178 ± 1.572 mm) than well-nourished (29.517± 0.171 ± 1.530 mm), with no significant difference (p>0.05). in mandible, the mean value of inter canine distance was found to be lower among malnourished group (24.819±0.187±1.652mm) than well-nourished (24.951± 0.176 ± 1.570mm), with no significant difference (p>0.05). concerning inter-molar distance, the mean value of maxillary inter-molar distance was found to be highly significant lower among malnourished group (41.840 ±0.177± 1.562 mm) than well-nourished group (43.162± 0.170± 1.520 mm) (p<0.01). in mandible, the mean value of inter-molar distance was found to be highly significant lower among malnourished group (38.356 ± 0.296± 2.616mm) than wellnourished group (39.397± 0.266± 2.378mm) (p<0.01). the maxillary and mandibular dental arch length for malnourished group and well-nourished among children aged 5 years are shown in table (2). concerning anterior arch length, the mean value of maxillary anterior arch length was found to be lower among malnourished group (8.145±0.113± 0.994mm ) than well-nourished group (8.165± 0.138± 1.235mm), with no statistically significant difference (p < 0.05). concerning mandible, the mean value of anterior arch length was found to be highly significant lower among malnourished group(5.595 ±0.087± 0.766mm ) than well-nourished group(5.878± 0.080± 0.719mm) (p < 0.01). concerning molar vertical length, the mean value of maxillary molar vertical length was found to be highly significant lower among malnourished group (24.729±0.163±1.442mm) than well-nourished group (25.912± 0.176±1.573mm) (p < 0.01). in mandible, the mean value of molar vertical length was reported highly significant lower among malnourished group (21.103±0.127±1.119 mm) than well-nourished group (22.400±0.119±1.063mm) (p< 0.01). table 1: maxillary and mandibular dental arch width (mm) for malnourished and well-nourished groups among children aged 5 years. malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value maxilla inter-canine distance 78 29.133 1.572 80 29.517 1.53 -1.923 0.054 intermolar distance 78 41.84 1.562 80 43.162 1.52 -4.824** 0.000 mandible inter-canine distance 78 24.819 1.652 80 24.951 1.57 -0.697 0.486 intermolar distance 78 38.356 2.616 80 39.397 2.378 -2.935** 0.003 ** p<0.01 j bagh college dentistry vol. 27(2), june 2015 the effect of pedodontics, orthodontics and preventive dentistry176 table 2: maxillary and mandibular dental arch length (mm) for malnourished and well-nourished groups among children aged 5 years. malnourished well-nourished statistical differences no. mean ±sd no. mean ±sd z -value p-value maxilla anterior arch length 78 8.145 0.994 80 8.165 1.235 -0.485 0.628 molar vertical length 78 24.729 1.442 80 25.912 1.573 -4.399** 0.000 mandible anterior arch length 78 5.595 0.766 80 5.878 0.719 -2.601** 0.009 molar vertical length 78 21.103 1.119 80 22.4 1.063 -49.576 0.000 ** p<0.01 discussion this study was conducted to assess the effects of malnutrition, on the oral health condition which include odontometric measurements and to compare these with the control group with similar characteristics to the study group except for the factor under investigation: therefore, the control group in the present study included wellnourished subjects who possess as much similarity as possible in terms of age, gender, social structure and geographic position. the 5 years index age was selected in the present study: this age is considered a critical human life stage which has recorded the past and present history of malnutrition and oral health conditions (18,19) . moreover, the study was conducted among children aged 5 years to represent the primary dentition stage, as teeth are considered to be fullsize and within the appropriate normal time of complete eruption of all primary teeth (14,20,21) . in addition, the 5 age group can represent a proper time for prediction of arch dimension and they are also considered as a static stage. moreover, the complete eruption of primary dentition by the age of three, and the entire arch and occlusion are relatively stable for the next two years until the eruption of permanent dentition. instead, the collected data were intended to be used for planning and evaluation of nutritional and odontometric measurements for the present group and the follower population in addition to standardize the measurement for nutrition status through oral picture conditions. protein energy malnutrition was assessed in the present study by using the anthropometric measurement (height, weight) through zscore standard deviation value system which expresses the anthropometric value as a score below or above the reference mean: their major advantage for the population is based on that group of scores which can be subject to statistic. the present study used three indicators (height for age, weight for age and weight for height) to classify purely malnourished from wellnourished children aged 5 years. furthermore, these measuring tools are simple and robust, and can be set up in any environment with noninvasive procedure. who (22) recommended using a -2sd cut off point which represents purely statistical separation of malnourished from wellnourished; therefore, the present study used this particular cut off point for the three nutritional health indicator (height for age, height for weight and weight for age). traditional casts were eliminated with the use of computer-aided diagnosis, particularly due to problems of storage in terms of space and cost, in addition to the risks of damage because of the brittle nature of dental cast. therefore digital photography was used in this study. as for the arch width and length measurements of the primary teeth among wellnourished, it is difficult to compare the data of present study with other studies. this may be due to differences in: the criteria of the sample selection and size; the methods used to determine arch dimensions; and the varying definitions of well-nourished group, as the previous studies might have included the different degrees of malnutrition. protein energy malnutrition may be reflected on retardation of the development and growth rate of the hard tissues (23). it affects directly by decreasing bone width as well as delaying the appearance of ossification centers (2426). the results of present study showed lower mean values of dental arches width and length for maxillary and mandibular dental arches among malnourished group as compared to wellnourished in both genders. this coincides with the finding by gonçalves et al (27) who found that the trabecular structure of the alveolar bone among well-nourished group was found to be thicker than in malnourished group, and well-nourished group appeared to have predominant type i collagen fibers. references 1blössner m, onis m. malnutrition. quantifying the health impact at national and local levels. geneva, world health organization, 2005. 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57(4): 393-398. 16chang hf, shian yy, chen kc. the relationship of dental crowding to tooth size, dental arch width and arch depth. proc nati sei counc repub china b 1986; 10(4): 229-235. 17hasan zs. the effect of nutritional status on dental health, salivary physicochemical characteristics and odontometric measurements among five years old kindergarten children and fifteen years old students. ph.d. thesis, college of dentistry, baghdad university, 2010. 18lingström p, moynihan p. nutrition, saliva, and oral health. nutrition 2003; 19: 567-9. 19warren jj, weber-gasparoni k, marshall ta, drake dr, dehkordi-vakil f, kolker jl, dawson dv. factors associated with dental caries experience in 1-year-old children. j public health dentistry 2008; 68(2): 70-5. 20hikmat bym. mesiodistal diameter and occlusal feature in the primary dentition of 4-5 years old children from baghdad –iraq. master thesis, college of dentistry baghdad university, 1989. 21al-timimy ia. anterior dental crown and its relationship to mesiodistal crown diameter of the teeth and arch dimension in three classes of molar relation. master thesis, college of dentistry, baghdad university, 2000. 22who. physical status: the use and interpretation of anthropometry. report of a who expert committee. who technical report series 854. geneva world health organization, 1995. 23edward fh, rosario ph, lin j. secular trend in tooth size in urban chinese assessed from two-generation family data. am j physical anthropol 2001; 115 (4): 312-8. 24alippi rm, barcelo ac, bardi m, friedman sm, rio me, bozzini ce. effect of protein-free diet on growth of the skeletal units of the rat mandible. acta odontol latinoamericana 1984; 1: 9–13. 25naranjo af, landín fac. efectos de la desnutrición protéicocalórica en el crecimiento mandibular de las ratas. rev cuba estomatol 1985; 22:168–76. 26alippi rm, meta md, oliveira mi. effect of proteinenergy malnutrition in early life on the dimensions and bone quality of the adult rat mandible. arch oral biol 2002; 47:47–53. 27gonçalves la, boldrini sc, capote tso, binotti cb, azeredo ra, martini dt, rosenberg b, bautz wg liberti ea. structural and ultra-structural features of the first mandibular molars of young rats submitted to pre and postnatal protein deficiencies. open dent j 2009; 3: 125–131. الخالصــــــة االسنان بالخصوص حساسة الى سوء . ذیة قد یؤثر عكسیاً على مختلف اوجھ النمو وكذلك مشاكل في مختلف المراحل في الحیاة في حیاة االنسان سوء التغ: الخلفیة ذة ھ. سنوات 5ھدف الدراسة أجریت لتحدید التغذیة على حجم السن لالطفال بعمر .سوء التغذیة قد یؤثر على قِراءات التي تشمل حجم السن وابعاد الفكین . التغذیة ھذه الدراسة شملت مجموعة من سیئ التغذیة : المواد والطریقة. الدراسة اجریت لمجموعة سیئي التغذیة بالمقارنة مع جیدي التغذیة مع مطابقة العمر والجنس الة الغذائیة أنجز من خالل استعمال تقیم الح). جیدي التغذیة 80سیئي التغذیة و 78(سنوات 5طفل بعمر 158واخرى من جیدي التغذیة متماثلة بالعمر والجنس الصور لنموذج الفك العلوي والسفلي تم . دراسة القیاسات الفمیة تم لبعدین قیاس. الطول بالنسبة للعمر والوزن بالنسبة للعمر والوزن بالنسبة: ثالثة معاییر تغذیة لكل من االسنان اللبنیة تم . رائھ من خالل برنامج سوفت ویر خاص بالحاسبةاخذھا لكل شخص من خالل استعمال جھاز فوتوغرافي خاص ومن ثم تم تحلیل الق سنوات ان القیم الوسطیة للفك العلوي والسفلي لبعد الفك العرضي والطولي 5اظھرت النتائج لألطفال بعمر :النتائج . استعمال قرائتین لبعد الفك العرضي والطولي وبعد الفك ) بین االنیاب(عة جیدي التغذیة وبوجود فرق معنوي عالي فیما عدا البعد الفك الغلوي والسفلي العرضي اقل في مجموعة سیئي التغذیة عنھ في مجمو .سنوات 5سوء التغذیة یؤثر تقلیل الفك العرضي والطولي لالطفال بعمر : االستنتاج. الطولي العلوي الخاص بالناب وبعد الفك السفلي بین الثنیة j bagh college dentistry vol. 26(1), march 2014 the effect of restorative dentistry 32 the effect of silicon di oxide nano -fillers reinforcement on some properties of heat cure polymethyl methacrylate denture base material hasanen a. alnamel, b.d.s. (1) mohammed mudhaffer, b.d.s., m.sc. (2) abstract background: the purpose of this study was to evaluate the effect of addition of surface treated silicon dioxide nano filler (sio2) on some properties of heat cured acrylic resin denture base material (pmma). the properties were impact strength, transvers strength, and surface hardness. materials and methods: in addition to controlled group sio2 powder was added to pmma powder by weight in three different percentages 3%, 5% and 7%, mixed by probe ultra-sonication machine.120 specimens were constructed and divided into 3 groups according to the test (each group consist of 40 specimens) and each group was subdivided into 4 sub-groups according to the percentage of added sio2 (finally each subgroup consist of 10 specimens). the tests conducted were impact strength (charpy test), transverse strength and indentation hardness (shore d). results: a highly significant increase in impact strength and transverse strength was observed with the addition of sio2 powder to (pmma) at the percentage of 3% and 5%; while a significant reduction occurred in both impact and transverse strength specimen’s tests at the percentage of 7% a highly significant increase in surface hardness was observed at the percentage of 3%, 5%and7. conclusion: the addition of nano sio2 powder to acrylic resin improves the impact strength and transverse strength of acrylic resin at the same time this addition increase surface hardness with the increase in the concentration of nano sio2 particles. keywords: pmma (heat cure acrylic), silicon di oxide nano-filler (sio2), nano technology. (j bagh coll dentistry 2014; 26(1):32-36). introduction despite the widespread use of (pmma) in prosthetic dentistry the fracture of dentures is a common clinical occurrence in prosthodontic service and still remains as an unsolved problem (1).to overcome their physical and mechanical limitations, polymers had been reinforced by adding materials such as metal strengtheners, carbon-graphite fiber, aramid fiber, and glass fiber (2). compared with glass-fiber reinforcement, silanated nano filler may be the material of choice for reinforcing denture base polymers because of their well-documented improvement in flexural properties and fatigue resistance, as well as good esthetic quality (3,4). in the chemical industry, during the past 10 years, research has been devoted to the development of a new industrial process that incorporates nanoparticles into (pmma) providing a new class of (pmma) that offers the strength of the nano-oxides, with the flexibility of polymer matrix(5).nano oxide as sio2, tio2, and zro2 are characterized by their small size, large specific surface area, active function, and strong interfacial interaction with the organic polymer (6). therefore, they can improve the physical, (1) m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2) assistant professor. department of prosthodontics, college of dentistry, university of baghdad. thermal and optical properties of the organic polymer, as well as provide resistance to environmental stress-caused cracking and aging of denture base (7). amorphous particles usually adopt a spherical shape (due to their microstructural isotropy), whereas the shape of anisotropic microcrystalline whiskers corresponds to their particular crystal habit (7). at the small end of the size range, nanoparticles were often referred to as clusters. spheres, rods, fibers, and cups are just a few of the shapes that have been grown. the study of fine particles is called micromeritics (8).increased bond strength by utilization of silanes is a result of a complex set of factors: wet out, surface energy, boundary layer absorbtion, polar adsorption, acid-base interaction, interpenetrating network formation and covalent reaction (9).the general formula of an organosilane (rnsix (4-n)) shows two classes of functionality. the x functional group was involved in the reaction with the inorganic substrate sio2. the bond between x and the silicon atom in coupling agents were replaced bond between the inorganic substrate and the silicon atom. x is a hydrolyzable group, typically, alkoxy, acyloxy, amine, or chlorine. the most common alkoxy groups are methoxy and ethoxy, which give methanol and ethanol as byproducts during coupling reactions (10). http://en.wikipedia.org/wiki/cluster_%28physics%29 http://en.wikipedia.org/wiki/sphere_%28geometry%29 http://en.wikipedia.org/wiki/fiber j bagh college dentistry vol. 26(1), march 2014 the effect of restorative dentistry 33 materials and methods silicon di oxide (sio2) nano filler with epoxy coupling agent, heat–curing acrylic (powder and liquid), hard dental stone type iii and separating medium (tin foil substitutes) were used. one hundred and twenty specimens were prepared for this study. the specimens were divided into 3 groups according to the tests selected. each group consisted of 40 specimens and these were subdivided according to the concentration of sio2 (silicon dioxide nano filler) into four sub groups as follow: 1group (a) control group (50 specimens of acrylic resin without sio2). 2group (b) 3% modified group (50 specimens of acrylic resin + 3% by weight (sio2). 3group (c) 5%modified group of (50 specimens of acrylic resin+5% by weight (sio2). 4group (d) 7% modified group of (50 specimens of acrylic resin + 7% by weight (sio2). ratio of mixing ratio of sio2with pmma sio2 amount of amount of polymer monomer 0% 0 100g 40ml 3% 3g 97g 40ml 5% 5g 95g 40ml 7% 7g 93g 40ml plastic model preparation: three plastic models were constructed by cutting plastic plate of different gauge (0.5, 2.5 and 4 mm) into desired shape and dimension using high accurate laser cutting machine (figure 1). figure 1: laser cutting machine 1. surface roughness test and shore d. hardness test bar shaped specimen with dimension of (65 mm x 10 mm x 2.5 ± 0.1 mm) length, width, thickness respectively (11). 2. transverse strength test bar shaped specimen with dimension of (65mm x 10 mm x 2.5 ± 0.1 mm) length, width, thickness respectively (11). 3. impact strength test: bar shaped specimen with dimension of (80 mm x10 mm x 4 mm) length, width and thickness respectively (12). mould preparation conventional flasking technique for complete dentures was followed during the mould preparation. separating medium (cold mold seal) was used for coating the plastic model and allowed to dry, before investing the lower portion of the metal flask which was filled with dental stone and mixed according to the manufacturer's instructions with vibration to get rid of the trapped air, then left to set. the plastic model was inserted to approximately one half of their depth as to be easily removed after setting of the stone fig (2). figure 2: mould preparation addition of silicon di oxide nano fillers the addition of modified sio2 nano filler powder was done by weight in four groups; the addition includes 3%, 5%, and 7% to monomer. an electronic balance with accuracy of (0.001g) was used, the filler well dispersed in the monomer by ultra-sonication type of mixing using probe sonication apparatus (120w, 60khz) fig (3) for three min. to brake them into individual nano crystals (13).the suspension of monomer with sio2 nano filler was immediately mixed with acrylic powder to reduce the possibility of particle aggregation and phase separation. figure 3: probe sonication apparatus packing of acrylic resin packing was started when the acrylic reached to dough stage, the resin removed from the jar and rolled, then packed into the mold previously coated with separating medium with the aid of polyethylene sheets. the two portions of the flask were closed together and placed under the j bagh college dentistry vol. 26(1), march 2014 the effect of restorative dentistry 34 hydraulic press, and the pressure was slowly applied on the flask so that the dough evenly flows throughout the mould space. the pressure was released, the flask was opened and the excess material was removed by sharp scalpel. a second trail closure was performed. the stone surface was again coated with the separating medium, allowed to dry and the polyethylene sheet was removed. finally the two portion of the flask were closed until an intimate contact obtained, and left under press (20 bars) for 5 minutes before clamping, and then transferred to the water bath curing this was done by placing the clamped flask in a water bath and processed by heating at 74°c for about one hour and half. the temperature then increased to boiling point for 30 minutes (14). finishing and polishing all the specimens were finished and .polished with a lathepolishing machine, flashes of acrylic were removed with w&h laboratory engine and an acrylic bur to get smooth surface stone bur was used followed by (120) grain sand paper with continuous cooling (immersed in cold water in rubber bawl, polishing was accomplished by using bristle brush and ruge wheel with pumice in lathe polishing machine, a gloss surface was obtained by using chamois baff and polishing swap. all specimens were measured by using digital vernier to make sure about their dimension. the speed of polishing machine was low speed (1500) rpm. with continuous cooling in order to avoid excessive heat, this may lead to distortion of the specimens impact strength test atest specimens the specimens were prepared with dimension (80mm x 10 mm x 4mm) (12)for unnotched charpy specimens impact strength test.ten specimens of each concentration were prepared make a total of (40) specimens for impact strength measurements. acrylic specimens were stored in distilled water at 37°c for 48 hour on the incubator before the test (11). b-testing equipment and procedure the impact strength test was evaluated following the procedure recommended by the use of impact testing device (12). the specimens were supported horizontally at each end and struck by free swinging pendulum of two joules and digital display to show the impact energy fig (4). the scale reading gives the impact energy in joules. the charpy impact strength of unnotched specimens was calculated in kilo joules per square meter (kj/m2) figure 4: impact testing device transverse strength test aspecimen design: the specimens used were prepared with dimensions of (65mm x 10mm x 2.5mm) (11).ten specimens for each concentration plus the control will make a total of (40) specimen for the measurement of transverse strength. all the specimens were immersed in distilled water on the incubator at 37°c for (48) hours before testing (11). b-testing procedure: test were performed using a universal instron testing machine, each specimen was positioned on the bending fixture which consists of two parallel supports (50)mm apart, the full scale was 50 kg, and the load was applied with a cross head speed of 1mm/min by a rod placed centrally between the supports making deflection until fracture occurs fig (5). figure 5: universal instron testing machine surface hardness testing aspecimen design: the specimens were prepared with dimensions of (65mm x 10mm x 2.5mm) according to (11). ten specimens for each concentration plus the control will make a total of (40) specimen for the testing of surface hardness. all specimens were immersed in distilled water for (48) hours before testing (11). b-testing procedure: test was performed using durometer hardness tester (shore d hardness) that was fabricated by (hartip 3000compant) according to (11) which is suitable for acrylic design material.the instrument consists of a blunt pointed indenter (0.8 mm in diameter) that present in a cylinder (1, 6 mm in diameter) .the indenter was attached to a digital scale that is graduated from 0 to 100 unit the usual method was to press down firmly and quickly on the indenter and recorded the maximum reading as the shore d j bagh college dentistry vol. 26(1), march 2014 the effect of restorative dentistry 35 hardness, measurements were taken directly from the digital scale reading. five measurements were recorded on different areas of each specimen (the same selected area of each specimen) and an average of five reading was calculated fig (8). figure 8: durometer hardness tester results and discussion impact strength table 2 shows the means, standard deviations, standard error of the means, minimum and maximum values of experimental specimens measuring impact strength in different concentrations of sio2 nano filler. table 2: distractive data of impact strength parameters analysis (kj/m2) group a group b group c group d n 10 10 10 10 mean 8.61 9.18 9.617 7.77 sd 0.264 0.113 0.168 0.365 se 0.835 0.359 0.532 0.115 range min. 8.1 9 9.42 7.2 max. 8.9 9.4 9.9 8.1 the highest mean value appeared in group c with a mean of 9.617 kj/m2 and the lowest mean was in group d which was 7.77 kj/m2.the increase of impact strength due to interfacial shear strength between nano filler and matrix was high due to formation of cross-links or supra molecular bonding which cover the nano filler and prevent cracks. also the crack propagation can be changed by good bonding between nano filler and matrix (16) transverse strength means, standard deviations, standard error of mean value, minimum and maximum values of the transverse strength of the acrylic resin are listed in table 3 for different groups of added concentrations of the nano filler table 3: descriptive data of transverse strength parameters (n/mm2) group a group b group c group d n 10 10 10 10 mean 114.937 120.145 124.562 111.6 sd 1.455 0.864 1.56 0.506 se 0.835 0.359 0.532 0.115 range min. 112.43 118.99 121.99 110.99 max. 116.68 122.1 127.01 112.08 from table 3 which plots the different means of transverse strengths across different concentrations of the added sio2 nano filler show that the highest mean appeared in group c which was124.562 contrast to group d with mean of111.6 which showed the lowest mean. the increase in transverse strength that occur with addition of 3%sio2 nano particles due to good distribution of the <100nm size of nano particles enable them to inter between liner macromolecules chains. segmental motion of the macromolecular chains were restricted and lead to increase strength and rigidity of the risen so this improved the fractural resistance and lead to improve transverse strength (17). surface hardness: table 4 shows the means, standard deviations, standard error of the means, minimum and maximum values of experimental specimen measuring surface hardness in different concentrations of sio2 nano filler. table 4: descriptive data of surface hardness parameters analysis group a group b group c group d n 10 10 10 10 mean 83.611 84.81 85.149 85.327 sd 0.767 0.919 0.558 0.332 se 0.242 0.290 0.176 0.105 range min. 82.44 83.01 84.24 84.4 max. 84.48 86.011 86.23 85.55 the highest mean value appeared in group d with a mean of 85.327 and the lowest mean was in group a (control) which was 83.611. this increase may be attributed to the randomly distributed particles of a hard material (silicon di oxide) into acrylic matrix. the slightly increase of the hardness of the nano composite at low nano particles concentration (3%) would be dominated by network density, while increased hardness of the nano composite at%5and7% attributed to the accumulation of the (sio2) particles in to the acrylic matrix specially on the surface (18). j bagh college dentistry vol. 26(1), march 2014 the effect of restorative dentistry 36 references 1. huggett r, bates jf, brook sc. the effect of different curing cycle on levels of residual monomer in acrylic resin dentures base material. quin dent techno 1984; 8(6): 345-65. 2. mccabe jf, walls awg. applied dental material. 8th ed. london: black well scientific publication; 1998. ch.12. p110-123 3. vallittu pk. effect of 180-week water storage on the flexural properties of e-glass and silica fiber acrylic resin composite. int j prosth 2000; 13(4): 334-9. 4. vallittu pk, narva k. impact strength of a modified continuous glass fiber –pmma. int j prosthodont 1997; 10:142-8. 5. hayashi s. review the reinforcement of dentures. j oral rehabil 2003; 26: 185-94. 6. khan z. soft palate obturation prostheses made with visible light cured resin j prosth dent 1989; 62(3): 671-67. 7. liu g, li yf, yan fy, zhao zx, zhou lc, xue qj. effect of nano scale sio2 and tio2 as the fillers on the mechanical properties and aging behavior of linear low-density polyethylene/ low-density polyethylene blends. j polym environ 2005; 13:339-48. 8. alam mm. synthesis, characterization and analytical applications of a new and novel ‘organic-inorganic’ composite material as a cation exchanger and cd (ii) ion-selective membrane electrode: polyaniline sn(iv) tungstoarsenate. react funct polym 2007; 55:277-90. 9. elrich fr. reinforcement of polymers. j dent res 1967; 46:1193. 10. sun l, ronald fg, suhr j, groanine jf. toughening polymeric composites using nano composite: a review composite science and technology, 2009. 11. american dental association specification no. 57, 12 for denture base polymers. chicago. : council on dental materials and devices.ansi/ada, 1999. 12. iso 179-1:2000: plastics -determination of charpy impact properties -part 1: non-instrumented impact test 13. mohammad m, groza, jr. in: suryanarayana c (ed). non-equilibrium processing of materials. elsevier science, oxford, uk, 1999. p. 347 14. craig rg, powers jm, john cw. dental material properties and manipulation. 8th ed. 2004, p.270-280. 15. sun l, ronald fg, suhr j, groanine jf. toughening polymeric composites using nano composite: a review. composite science and technology 2009. 16. katsikis n, franz z, anne h, helmut m, andry v. thermal stability of pmma /silica nano-and micro composite as investigated by dynamic-mechanical experiment. polym degra and stability 2007; 22: 1966-76. 17. anusavice kj. philips science of dental materials”, 12th ed. philadelphia: w.b. saunders co.; 2002. p. 211-71. 18. nabil i. evaluation the effect of modified nano filler addition on some properties of the heat cure acrylic risen denture base material. a master thesis. college of dentistry, university of baghdad, 2011. 19. mohammed d. the effect of nanozio2 reinforcement on the mechanical properties of heat cured acrylic. a master thesis, college of dentistry, university of baghdad, 2012 j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 30 diet and orthodonticsa review maymona ali ibraheem (1), mohammed nahidh (2) https://doi.org/10.26477/jbcd.v33i3.2951 abstract during the course of fixed orthodontic therapy, patients should be instructed to eat specific food stuffs and beverages in order to maintain good health for the dentition and supporting structures, and prevent frequent attachment debonding that prolongs the treatment duration. after searching and collecting articles from 1930 till july 2021, the current review was prepared to emphasize various types of foods that should be taken during the course of fixed orthodontic therapy and to explain the effect of various food stuffs and beverages on the growth and development of craniofacial structures, tooth surfaces, root resorption, tooth movement, retention and stability after orthodontic treatment and the effect on the components of fixed orthodontic appliance. key words: diet, nutrition, fixed orthodontics, health. (received: 26/6/2021, accepted: 26/7/2021) introduction individuals are more concerned and aware of maintaining healthy lifestyle and good health that necessitates a well-balanced diet. generally, nutrition affects the development of many body's organs in addition to the sexual development's timing, so delay menarche is mostly seen with malnutrition , preponing it in the obesity (1). dietary counseling and nutritional education associated with oral health have become one of the significant dental education components, with so much emphasis on more nutritional food choices and healthier foods. american dental association (2) reported the accreditation guidelines of dental schools "the graduate must be competent to provide dietary counseling and nutritional education relevant to oral health." lately, governments in various nations were working for formalizing systems of national nutrition monitoring, and there were new fat and salt labeling laws for foods (3). with the spotlight on nutritional issues, it seems like a good time to look at how the orthodontic treatments are affecting the diet of patients. orthodontic treatment causes physiologic, physical, and emotional stress, which increases nutrient utilization and mobilization, thereby increasing an individual's nutritional needs. because the nutritional requirements of adolescents (the age of a common orthodontic patient) were already strained by development and growth, the emotional stress of puberty, maintaining a well-balanced diet is critical (4). orthodontists frequently advise their patients to eat soft foods throughout treatment for avoiding pressure sensitivity, yet some are providing specific diet charts or instructions, without (1) general dentist, baghdad, iraq. (2) assistant professor. department of orthodontics, college of dentistry, university of baghdad. corresponding author: m_nahidh79@codental.uobaghdad.edu.iq them, patients often turn to easy-to-eat, convenient foods, paying little attention to the food's nutrient content (5). this review was prepared to highlight the types of foods that should be taken during the course of fixed orthodontic therapy and to explain the effect of various food stuffs and beverages on the growth and development of craniofacial structures, tooth surfaces, root resorption, tooth movement, retention and stability after orthodontic treatment and the effect on the components of fixed orthodontic appliance. review of literatures diet and nutrition the sum of food consumed by a person or other organism is called diet, while nutrition can be defined as “the science of food, nutrients and other substances. in addition to their interaction, action, and balance in relation to the health and diseases and the processes through which organisms ingest, absorb, digest, utilize, transport and excrete foods” (6). classification of foods milward and chapple (7) divided food into two broad categories; macronutrients (fats, carbohydrates and proteins) which are required in large quantities from the diet, and micronutrients (minerals, vitamins, trace elements, and aminoacids) which are only required in small quantities in the diet and considered essential for a range of biological processes important in supporting optimal health. in another classification, foods scientifically can be divided into 6 groups; each one of them presents some, yet not all, of the nutrient’s humans require. each group is equally important; no one can take the place of another. humans require all of them for good health. a healthy diet consists of the following food groups (8): https://doi.org/10.26477/jbcd.v33i3.2951 j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 31 1. cereals (carbohydrates) this group meets a fourth of total energy needs. bread and rice are the most common cereal forms consumed in diet. since the majority of grain products are easy to chew and soft, they are an easy food group for braces wearers. 2. milk and milk products dairy products are comprised of approximately fourth of total dietary needs. a calcium-rich diet is essential for strong teeth and bones. calcium, potassium, vitamin d, and even protein are all found in dairy products. in addition, dairy products are considered as a great choice for braces wearers since they are soft and require little chewing. milk, yogurt, milk shakes, and various cheese types are typical dairy products in diets, and patients must be encouraged to consume them. 3. fruits fruits are important for healthy diet, yet they might be difficult to eat with braces. due to the orthodontic brackets, hard fruits such as unripe pears, apples, and peaches might be difficult to bite into. even the softest food might be a challenging following a wire change. hard fruits might be cut into small bite sized pieces and chewed with the back teeth. in addition, fruit juice is a healthy and convenient option if nothing else works. with all that metal around the teeth, it is often difficult to chew or bite something extremely cold. 4. vegetables vegetables make up approximately a fourth of total dietary requirements. vegetables are high in minerals and vitamins, which are needed by growing bodies. because the majority of vegetables are consumed cooked, they do not pose a significant problem for braces wearers. they might be meshed up more for added comfort. salads or raw vegetables might be cut or grated into bite-sized pieces. 5. nuts and seeds choosing carefully from such vegetarian group will allow keeping the braces in place. seeds and nuts are both small and hard, which can be difficult for people who wear braces. 6. meat meat is difficult to chew for people who wear braces due to the fact that it is fibrous. it isbest not to eat meat straight from the bone. as a source of protein, cottage cheese or tofu are safe alternatives to meat. before eating, orthodontic patients must choose tender, lean cuts of meat and cut them into bite-size pieces. relation between malocclusion, malformation and malnutrition the adequate development and growth of an individual is determined by the intake of required nutrition. any nutrient deficiency throughout the formative stages of organs and tissues causes permanent and severe deformation. also, nutrition affects the sexual development's timing, delay menarche in cases of malnutrition and preponing it in cases of obesity (1). there is a link between malnutrition and slow development and growth of the facial bones (9). proteins play a role in the growth of teeth and jaws in animals, with a considerable impact on the size and shape of mandible so as a result, malnutrition causes alterations in spatial arrangements that are related to teeth in jaws, both absolute and relative. malnutrition can cause a decrease in jaw height, skull base length (10), lower facial height and maxilla-mandibular width (11). other undesirable skeletal effects include enlargement of medullary spaces, cortical thinning, and decreased osteoclastic and osteoblastic activity (12). it has been suggested that the dietary deficiencies are considered as a cause of dentofacial deformities. animals fed on diet low in zinc, riboflavin and folic acid might have cleft lip and palate in offspring (13). nutritional deficiencies might change the functions related to the body's endocrine glands, affecting not just the whole body's development and growth, and also the dentition (14). in a cross-sectional study, jasim et al. (15) found that there were significant relations between nutritional status with crowding, facial height, and adverse oral habits. these might be modulated by other local factors like caries and bad oral habit sequel. the effect of nutritional status on the occlusion of primary dentition had been evaluated by abdul wadood and khalaf (16) among iraqi 5 years old children. this study failed to find out a relationship between the occlusal relation and malnutrition. on the other hand, jabber and diab (17) concluded that prenatal malnutrition had some effect on the occlusal relation among kindergarten children. minerals and vitamins are important parts of a balanced diet and play a significant role in the normal development and growth. calcium, phosphorous and vitamin d are vital for the formation of teeth and bones. deficiency of vitamin d results in retarded teeth, jaw and condyle development, rickets and maxillary dysplasia, and it makes it difficult to close facial j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 32 sutures, resulting in an open bite, transverse hypodimension, and a misshapen palate (18). a person with a magnesium deficiency may develop a bruxism habit (19). an excess of vitamin a during the critical growth period markedly inhibits the neural crest cell development and upsets the normal balance between bone formation and resorption (18), while the deficiency of vitamin a combined with deficiency of protein results in insufficient bone growth and malocclusion of teeth (20). in comparison to subjects on a hard diet, subjects on a soft diet had narrow arches due to underdeveloped muscles and supporting structures (21). breastfeeding is essential for the synchronicity and development of orofacial muscles, which allows the maturation of different vital functions and the dentofacial structures' growth (22). altered growth of craniofacial bones led to insufficient space for teeth to erupt resulting in crowding, impactions and ectopic eruptions (23). effect of orthodontic treatment on diet the effect of fixed orthodontic treatment on patients’ weight and dietary intake are still requiring further investigations. orthodontic treatment causes physical, physiological and emotional stresses which induce changes in the nutrition of patients. orthodontic treatment may alter the consistency, quality and quantity of a person’s diet. patients having orthodontic treatment will need to have alteration in their food choices because of discomfort, sensitivity and pain on biting and chewing (24). for the purpose of avoiding bracket debonding and appliance breakage throughout fixed orthodontic therapy, orthodontists advise patients to avoid gummy, sticky, chewy, or extremely hard foods. throughout orthodontic treatments, a preference for soft foods leads to dietary changes that decrease carbohydrate and fiber intake while increasing fat intake. manganese and copper levels were found to be lower with orthodontic treatments by strause and saltzmann (25). it was linked to a lack of whole grains, nuts, and a reduction in vegetable and fruit consumption. copper is needed for the production of red blood cells and hemoglobin, as well as being a component of redox system enzymes and collagen cross-linking, in addition to normal pigmentation. manganese is essential for bone remodeling as well as glucose metabolism (26). effects of the diet on the orthodontic treatment the success of orthodontic treatment is heavily reliant on the oral tissues' health. the orthodontic treatment is hampered by inflamed oral tissues, frequent ulcerations, and compromised periodontal tissues. as a result, the quality of one's diet has a direct impact on the effectiveness of orthodontic treatment (27). effect on the dental and periodontal structures 1. demineralization and dental caries decalcification of teeth under brackets and bands is caused by a high intake of carbonated soft drinks, uncontrolled consumption of sugar, and poor oral hygiene, and if left untreated, it can lead to carious lesion. in a four-week period, glatz and featherstone (28) found measurable demineralization, gingival to brackets and bands. the existence of elastics, arch wires, springs, and other attachments interferes with the patient's capability for keeping a few portions of the brackets and teeth clean, resulting in demineralization. white spot lesions can be seen as a result of this. various foods contain buffers, such as protein in meat and calcium in milk, that might absorb or neutralize acids. topical fluoride prevents dental caries via converting hydroxylapatite crystals in enamel to fluorapatite, which is less acid soluble. excess fluoride, on the other hand, must be avoided for preventing dental fluorosis, which is characterized through brownish, corroded teeth (27). with a high intake of acidic drinks or a large amount of lemon, enamel surface erosion might be anticipated (29). 2. root resorption one of the major iatrogenic problems related to orthodontic treatment is root resorption, both internal and external resorption are possible. the root resorption problem is a significant challenge in orthodontic treatment that is influenced by diet. as stated by marshall et al. (30), animal studies show that deficient diets result in more resorption than adequate diets. following vitamin and calcium deficiency, dogs were more susceptible to resorption, according to a beck and harris' study (31). vitamin d balances phosphorus and calcium in the body, and a lack of it causes cement resorption (32). in moderate hypocalcaemia, engstrom et al. (33) had hypothesized that an increase in alveolar bone turnover is the root resorption cause. j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 33 3. periodontal problems plaque and calculus formation is aided by a soft diet, whereas fibrous and hard foods have both a surface cleansing effect that prevents plaque formation and a stimulatory effect that increases the density of the alveolar bone (34). generally, nutritional deficiencies do not cause gingivitis or the formation of a periodontal pocket, but they can worsen the damaging impacts of the local irritants on periodontium (35). vitamins are of high importance for maintaining periodontal healthy since the experimental animal studies showed that vitamin a deficiency may result in hyperkeratosis and hyperplasia of the gingiva with a tendency for increased periodontal pocket and healing retardation of the gingival wound (32). gingivitis, angular chelitis, glossitis, and oral mucositis have all been linked to the deficiency of vitamin b. non-inflammatory necrosis of the periodontal ligament, gingiva, and alveolar bone is a sign of folic acid deficiency. scurvy is caused by a disruption in collagen metabolism, which affects repair potential and tissue regeneration (32,36). effects upon tooth movement and orthodontic correction stability orthodontic forces induce the biological responses, involving complicated combining osteoblastic with osteoclastic activities. the movement of the tooth requires the simultaneous synchronous collagen metabolism functioning. the lack in the normal synthesis of the collagen, due to a lack in the ascorbic acid, has led to a nearly full osteogenesis cessation and periodontal ligament disorganization. it seemed that the ascorbic acid is important for normal alveolar bone and periodontal ligament morphology (37). the metabolism of the collagen is dependent upon the adequate vitamin c supply for producing mature collagen. it was noticed as well in individuals who have vitamin c deficiency that the teeth that were orthodontically corrected have not been stable and relapse faster in comparison with individuals who are not vitamin c deficient because of the presence of a large resorption lacunae and an increase in the osteoclastic activities, that are secondary to the deficiency of vitamin c, which has jeopardized the remodeling of the bone that slows the movement of the orthodontic tooth (38). moreover; miresmaeili et al. (39) found that oral administration of vitamin c for rats can enhance tooth movement with the formation of more osteoclast lacunae around the root in the pressure site. it was stated that 17% to 72% of the orthodontic patients can have sub-optimal ascorbic acid levels and a deficiency could result in affecting the periodontal ligament’s connective tissue and the osteoid formation. in addition, nutritional stress to the periodontium, coupled with the irritation of orthodontic bands and brackets may cause an altered gingival response thereby impacting the movement of the tooth as well as the retention that follows the orthodontic treatments (24,40,41). dietary lipids contain two types of polyunsaturated fatty acids essential to the human body namely; the n-6 and n-3 series are derived from linoleic and alpha-linolenic acids, respectively. the n-6 fatty acids produced arachidonic acid, while dietary n-3 fatty acids have actions similar to those of non-steroidal anti-inflammatory drugs (nsaids) by inhibiting the appearance of osteoclasts thus reducing the rate of tooth movement. so, intake of dietary lipids might affect bone remodeling and subsequently orthodontic tooth movement (42,43). carbonated soft drinks have deleterious effect on tooth movement as they may alter bone metabolism and impact the process of the bone remodeling and successive orthodontic tooth movement (29). for the modest bone health, the ratio of calcium phosphorous has to be > 1 in the adolescent diet (44). vitamin d had proved to increase the rate of tooth movement in human beings after local administration in the periodontal ligament space (45). effect on fixed orthodontic appliance materials and components 1. effect on the shear bond strength many studies (both in-vivo and in-vitro) have been conducted to test the effect of different types of food simulants and carbonated soft drinks on the shear bond strength, adhesive remnant index and microleakage of orthodontic brackets. the results varied according to the experiments but the general findings indicated that soft carbonated drinks may have an impact on the shear bond strength in two ways; first, through the deterioration of the adhesive material structure, and second, through leading to erosive lesions on the surface of the enamel that surrounds the brackets, with the main beverage composition effect and the overall acid content, instead of the beverage ph, which determines actual aggression towards enamel (46-49). j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 34 2. impacts upon the chemical characteristics, surface topography and corrosion resistance generally, food simulants and carbonated soft drinks play a role in the alteration of the chemical compositions and surface topography of different metal orthodontic brackets and archwires. these can be detected by releasing of different ions, developing surface roughness and changed morphology due to the aggressiveness of these stuffs in destructing the protective oxide layer on these materials (50,51). 3. effects upon the color stability of clear retainers, elastics and esthetic brackets there is general agreement about developing discoloration of clear retainers, esthetic brackets and clear elastics by different food and beverages stuffs. this was confirmed by various in-vivo and in-vitro studies (52-55). 4. effects on elastics’ force decay the findings of different studies suggested a controversial impact of carbonated soft drinks on the force decay of various types of elastics. this may be related to the type, method and configuration of the manufacturing in addition to the ph, content, and temperature of carbonated soft drinks (56-59). balanced diet and orthodontic treatment throughout the orthodontic treatment, the nutritional history has to be considered and the diet of the patient must be adjusted for including all of the important elements, keeping under consideration of the patient’s convenience, habits, preferences and dislikes. the dairy products (such as milk, ice cream and cheese) have to be prescribed throughout the orthodontic treatment, due to the fact that they are soft and helpful for the remodeling of the bones throughout the movement of the tooth (60). khatri and kolhe (61) stated that throughout the orthodontic treatments, the patients are asked to follow a pattern of stop, halt and go in the food consumption; some of them are simply presented in figure 1: 1. stop (never eat) chewing gums, toffees, caramel, nan and boiled candy, pop-corn kernels, ice cubes, corn, raw apple or carrots, pizza crust, hard pretzels, nuts, chocolate chips, carbonated soft drinks, dry fruits, guava, meat with bone, halwa, ice cream with nuts, and sticky snacks. 2. halt (think before eating) nacho chips, bagel, raw vegetables, ribs, chicken wings, loose corns, hard fruit cut to smaller pieces, fruit with pits, high sugar foods and crusty bread. 3. go (can eat) french fries, potato chips, steamed vegetables, sausage, yoghurt, soup, jelly, cheese, cereal in milk, milk shakes, eggs, banana, ice cream with no nuts, cake, biriyani, pasta potatoes, pudding, caramel bars, peanut butter cups, orange, boneless meat, burger, fish, puri bread. figure 1: allowed and not allowed foods in the course of fixed orthodontic therapy (62) j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 35 dietary considerations in orthognathic surgery patients before and after jaw surgery, it is important to eat well as healing requires good nutrition. the mouth represents entry portal of the foods to the body, which is why, maxillofacial surgery of those structures could lead to the impairment of the food intake before, as well as after the surgery and so sufficient nutritional support has to be ensured for those patients. after surgery, it is often best to take smaller meals or snacks more frequently rather than relying on the typical three meals per day (63). patients need a source of energy as well as a source of protein. the proteins, carbohydrates, and fatty acids are energy sources. glucose is a source of energy for vital organs like brain. however, hyperglycemia is not desirable. fatty acids produce more energy and certain essential fatty acids must be supplied by the diet. protein is also important for cellular proliferation and imparting strength to the fracture repair. if it is absent then the wound healing is delayed (4). vitamin a helps in epithelization, synthesis of the collagen and the cross linking and differentiation of the fibroblasts. vitamin c deficiency leads to impairment in the collagen synthesis and wound healing. calcium and vitamin d help in healing the hard tissues. vitamin e acts as an antioxidant and thus reduces the damage from the free oxygen radicals. large vitamin e doses inhibit the healing as well. vitamin k helps activate various factors of clotting and thus is essential for blood clot formation during healing (43). initially after surgery, patients should eat and drink using a small spoon, plastic syringe or straw (36,64). just like in normal orthodontic patients, orthognathic patients have a list of allowed and non-allowed food stuffs as followed (4,63): 1. foods preferred • puree/liquidized diet • use milk, fruit juice, sauces, gracy, soup etc. • meat, poultry, fish and alternatives should be liquidized with savory saur • carbohydrates-mash potato with milk and butter • fruit and vegetables can be liquidized 2. foods to avoid • stringy foods such as green beans and celery • crunchy food such as muesli, crisps, toasts, nuts and crispy bread • foods with skins or husk such as sausages, peas etc. • chewy food such as tough meat and toffees dietary allergy dietary substances might act as allergens leading to sensitize the human immune system resulting in hypersensitivity reaction. such allergies can produce allergic rhinitis leading to oral breathing, which subsequently can affect the growth and development of both dental arches and the underlying skeletal bases often irreversibly causing what is called long face syndrome. the most common allergens included; cow milk, used in processed infant foods, wheat and wheat products, fish and eggs (42). conclusions the following conclusions have been drawn from this review: 1. for the purpose of maintaining a healthy body, there is a high significant value in following a balanced diet that includes of all of the fundamental nutrients required by the body and also meets the individual’s calorie requirements, with their age, activity level and gender under consideration. 2. for the optimization of the physiological responses of the patient to the orthodontic treatments, it can be useful providing the dietary guidance to the patient by obtaining the history of the nutrition, evaluation of the diet, instructing patients about the components of the diet that are important for the oral health, motivating them to enhance the diet and follow up for supporting the patient’s efforts in changing the food behaviors. 3. orthodontists usually instruct the patients to eat soft foods throughout the treatment for the purpose of accommodating the pressure sensitivity that is encountered with the movement of the tooth. 4. patient who have braces, preferring or switching over to the convenience foods like the pastries, cakes, cookies and ice creams that have high amount of the fats and simple sugars have to be educated about the value of the vegetables, fruits, cereals and grains in their daily nutrition. 5. the compliance with the dietary advices is more possible in the case where the followup has been provided. the dietary progress has to be discussed at further appointments. the nutrition care has to be one of the integral parts of the orthodontic care. 6. the effect of some food stuffs and beverages on the general health, bone, teeth and orthodontic materials used inside the oral cavity like brackets, arch wires, elastics, and j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 36 springs should be discussed with the orthodontic patients before commencing the treatment with fixed orthodontic appliance. 7. pregnant women should be advised to take supplementary vitamins and minerals to ensure proper development of fetus organs. after delivery, breast-feeding is the best type of feeding during that period for providing the useful components in mother milk and aiding in well-developed dental arches. references 1. epstein lh, wing rr, valoski a. childhood obesity. pediatr clin north am 1985; 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2018. https://twitter.com/appleorthoch/status/845312007268171776 https://twitter.com/appleorthoch/status/845312007268171776 j bagh college dentistry vol. 33(3), september 2021 diet and orthodontics 38 articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. المستخلص جيدة صحة على الحفاظ أجل من معينة ومشروبات أطعمة لتناول المرضى توجيه يجب ، الثابت األسنان تقويم عالج فترة خالل المتكرر الذي يطيل فترة العالج. بعد البحث وجمع المقاالت من عام فك ارتباط الحاصرات التقويميةلألسنان والهياكل الداعمة ومنع إعداد المراجعة الحالية للتأكيد على أنواع مختلفة من األطعمة التي يجب تناولها أثناء العالج التقويمي ، تم 2021حتى يوليو 1930 الجذور ارتشافالثابت وشرح تأثير المواد الغذائية والمشروبات المختلفة على نمو وتطور الهياكل القحفية الوجهية ، أسطح األسنان ، ج التقويمي والتأثير على مكونات جهاز تقويم األسنان الثابت. ، حركة األسنان واستقرارها بعد العال ola.doc j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 78 effect of silver nitrate incorporation into heat polymerized acrylic resin on some mechanical properties ola khaleefah ahmed al-husayni, b.d.s. (1) nabeel abdul fatah hatoor, b.d.s., m.sc. (2) abstract background: polymers are very rarely used in their form. these modifications are carried out in order to improve the properties of polymers.recently silver have been used successfully as antimicrobial (medical and dental) biomaterials that can prevent caries and infection of implants. the aim of the present in vitro study is to evaluate the effect of addition of silver nitrate to acrylic resin in different concentrationsthrough several tests part of these are: the effect of this additive on impact strength, transverse strength, and tensile strength of agno3 – loaded resin, and to assess any effect of addition of silver nitrate on coloration of acrylic resin. materials and methods: different concentrations of silver nitrate (9.375, 15, 30, 60, 120, 150, 300, 600 and 900 ppm) were prepared from stock solution of 1000 ppm silver nitrate. the specimens were prepared in accordance with the manufacturer's instructions and the tested silver nitrate solution was added to the acrylic resin powder and monomer in a fixed volume (0.2ml). controls devoid of silver nitrate were included. results: fourier transform infra-red confirmed that there was no chemical bond between the poly methyl methacrylate and silver nitrate. there was insignificant increasing (p=0.05) in impact strength observed when compared with control group. in transverse strength test, significant reduction was show (p<0.001). while for tensile strength there was insignificant reduction with 9.375(p=0.05ns) and 15(p=0.42ns) ppm silver nitrate. however, it was significant above 15 ppm (p<0.001). darkening of silver nitrate -loaded resins were shown to be started with concentration of silver nitrateof 300 ppm and above. conclusions: the additions of silver nitrate to acrylic resins yield good color stability and mechanical properties, depending on the concentration of silver nitrate. keywords: silver nitrate, acrylic resin, infra-red spectra, strength, coloration. (j bagh coll dentistry 2014; 26(4):78-85). introduction little information is available about the impact of silver nitrate into heat polymerized acrylic resin. so this prompted us to shed light on this research. there is a need for effective broad -spectrum antimicrobial resin materials in dentistry; it is well-known that removable denture bases fabricated from heat-polymerized acrylic resins may act as a reservoir for microorganisms and contribute to re-infection in denture wearers 1. for elderly and institutionalized patients with limited motor skills and special needs, this treatment is further complicated because of some factors such as loss of memory, difficulty in rendering appropriate cleaning for their oral cavities.unfortunately, current standers of treatment such as the use of antimicrobial mouthwashes, proper –tooth brushing technique have limited success or side -effects due to problems with patient compliance and the development of antibiotic resistance strains of bacteria. thus a broadspectrum antimicrobial resin is needed 2. silver ions have been reported to inactivate important enzymes and affect the application mechanism of the dna in bacteria. ag ions have (1)master student. department of prosthodontics, college of dentistry, university of baghdad. (2)professor, department of prosthodontics, college of dentistry, university of baghdad. been reported to attach to the outer membrane and affect the permeability as well as induce structure changes in the cell – ultimately leading to cell death .in addition; ag does not cause resistant bacterial strains to develop 3,4. for dental application, the development of other methods of drug elution, such as ag-zeolite and sio2 filler were incorporated into urethane acrylic monomer in different amount to develop a new temporary filling materials with antibacterial activity against some oral bacterial growth 5, silver containing materials like novaron, amenitop and ais were incorporated into light activated resin composites attended to decrease the frequency of secondary caries around the restorations 6. the sol-gel derived silica glass powders containing silver are believed to be useful as an antibacterial material for medical applications such as filler of composite resin for dental restoration 7, and the incorporation of nanometer-sized silver-supported antimicrobial agent into denture base materials to investigate the distributionand to study the release mode of silver ions from the base 8,9. there are few studies about the addition of silver particles to denture base resin have been published 8,9 . so the aim of the present in vitro study is to evaluate the effect of addition of silver nitrate to acrylic resin in different concentrationsthrough several tests part of these are: the effect of this additive on impact strength, transverse strength, and tensile strength of agno3 – loaded resin, and to assess any effect j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 79 of addition of silver nitrate on coloration of acrylic resin. materials and methods preparation of silver nitrate (agno3) concentrations for studying samples different concentrations of agno3 solutions were prepared from stock solution of 1000ppm of agno3. serial concentrations were prepared: (15, 30, 60,120ppm), (9.375, 150,300,600 ppm) and 900ppm.the prepared concentrations were confirmed by atomic absorption spectrophotometer (phoenix -986/ aa spectrophotometer, uk) and stored in dark bottles wrapped with aluminum foil. agno3 – loaded resin specimens fabrication for impact strength test, specimens with a bar shaped specimen with dimensions of (80mm x 10mm x 4mm) length, width, thickness respectively 10. for transverse strength test, a bar shaped specimens with dimension of (65mm x 10mm x 2.5mm) length, width, thickness respectively 11. for tensile strength test, flatdumbbell shaped specimens with dimensions (16± 1mm length; 3± 0.2 mm width and 2± 0.2 mm thickness at the parallel segment 12. the patterns invested in flaks with dental stone. after setting of the stone, the flasks were opened and patterns removed, leaving cavities that were used as matrixes for the fabrication of heat polymerized acrylic resin specimens. for each assay, 60 specimens were fabricated, and assigned to 10 groups (n=6) according to the concentrations of silver nitrate solutions: zero (control);(9.375,15,30,60,120,150,300,600,and 900ppm). for this, the heat cure denture base resin(non – veined acrylic, powder and liquid, ivoclar vivadent ag, italy) was mixed according to manufacturer instruction, p/l ratio: 2.25g of powder was mixed with 1ml liquid (0.8ml monomer + 0.2ml agno3 solutionof each concentration). specimens devoid of silver nitrate were included as control.these were mixed manually, by the same operator. the material were packed and polymerized following the manufacturer's instructions. visual inspection of agno3 – loaded resin samples samples were evaluated visually by comparing the tested samples with the control group. characterization of agno 3-loaded resins the fourier transform infra –red ( ftir) spectra was performed (on ir affinity1/shimadzu corporation/japan spectrophotometer) using kbr and caesium iodid (csi) pellets to determine whether or not functional groups of the agno3 have been attached to the heat cured pmma by analyzing the characteristic vibrations of functional groups 22 . impact strength test the test was measured using charpy type impact testing instrument the specimen was supported horizontally at its ends and strucked by a free swinging pendulum released from a fixed height in the middle. a pendulum of 2 joules testing capacity was used. the scale reading gave the impact energy absorbed to fracture the specimen in joules when struck by sudden blow.the charpy impact strength of unnotched specimen was calculated in kj/m2 according to anusavice 13 as given by the following equation: impact strength= since: e: is the impact absorbed energy in joules. b: is the width in millimeters of the test specimens. d: is the thickness in millimeters of the test specimens. transverse strength test the test was measured usinginstron testing machine, each specimen was positioned on bending fixture, consisting of two parallel supports (50)mm apart, the full scale load was 50kg, and the load was applied with cross head speed of 1mm/min by rod placed centrally between the supports making deflection until fracture occurred. the transverse bend strength was calculated using the following formula 13: 3pl transverse strength (mpa) = 2bd2 since: p: is the peak load. l: is the span length. b: is the sample width. d: is the sample thickness. e b.d j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 80 tensile strength test the test was measured using tinius olsen testing machine at a cross head speed of 0.5 mm/min and with 50 mm grip – to – grip distance. the force at the failure was recorded in newton (n) and the tensile strength values were calculated from the following equation: f (n) tensile strength (n/mm2) = a (mm2) ` since: f: maximum load at failure (newton). a: cross sectional area (mm2). results visual inspection of agno3 – loaded resin samples as the concentration of agno3 increased, the prepared agno3 –loaded resin samples start to show visually some darkening started at 300 ppm agno3 and above figure (1). characterization of agno 3-loaded resins the results of ftir (fourier transform infra – red) spectra of pmma and agno3 –loaded resins in kbr and caesium iodid (csi) discs, showed no change in the shape of absorption peaks between pmma(control) and agno3 –loaded resinsindicating no chemical bond between the pmma and agno3 figures(2-3-4-5). impact strength test as shown in table 1-2, the mean impact strength was highest in the group with 60 ppm agno3 (12.8 kj/ m 2) and lowest in the control group (10.6 kj/m2). the difference in mean impact strength between the concentrations of agno3 and control group was statistically insignificant. compared to control the lowest concentration of agno3 (9.375ppm) was associated with an average increase in impact strength of 0.1kj/m2. the effect of this very low concentration was evaluated as weak (cohen's d = 0.17). this effect was statistically insignificant .the 60 ppm agno3 was associated with highest increase in mean impact strength of 2.2.this effect was statistically significant which rated as a strong effect (cohen's d = 2.63) . transverse strength test as shown in table 34, the mean transverse strength was highest in the control group (77.8 mpa) and lowest in the group with 120 ppm of agno3 (55.4mpa). the difference in mean transverse strength between the concentrations of agno3 and control group was statistically significant. compared to control the lowest concentration of agno3 (9.375 ppm) was associated with an average reduction in transverse strength of (14mpa), the effect of this very low concentration was evaluated as strong (cohen's d = 4.18).this effect was statistically significant .the strongest effect was with 120 ppm agno3 (reduction in transverse strength) (cohen's d greater than 6). tensile strength test as shown in table 5-6, the mean tensile strength was highest in the control group (54 mpa) and lowest in the group with 60 ppm agno3 (36.8mpa). the difference in mean tensile strength between the concentrations of agno3 and the control group was statistically significant. compared to control the lowest concentration of agno3 (9.375ppm) was associated with an average reduction in tensile strength of 5 mpa. however, this effect was statistically insignificant. the 15 ppm agno3 was associated with very small and statistically insignificant reduction in tensile strength of 2.1mpa. on the other hand, the agno3 concentration associated with strongest effect (reduction in tensile strength) was the 60 ppm (cohen's d greater than 4). table 1: descriptive data of impact strength test (kj/m2) study groups (concentration of added agno3 in ppm) control 9.375 ppm 15 ppm 30 ppm range (9.67 to 11.11) (9.94 to 11.62) (10.53 to 12.23) (9.78 to 13.51) mean 10.6 10.7 11.5 11.8 sd 0.65 0.56 0.63 1.54 se 0.27 0.23 0.26 0.63 n 6 6 6 6 difference in mean compared to control reference 0.1 0.9 1.2 cohen's d reference 0.17 1.37 1.03 p (lsd) reference 0.88[ns] 0.24[ns] 0.1[ns] j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 81 table 2: descriptive data of impact strength test (kj/m2). study groups (concentration of added agno3 in ppm) 60 ppm 120 ppm 150 ppm p (anova) range (11.27 to 13.72) (9.25 to 12.66) (8.86 to 15.17) 0.05[ns] mean 12.8 10.7 11.8 sd 0.95 1.57 2.09 se 0.39 0.64 0.85 n 6 6 6 difference in mean compared to control 2.2 0.1 1.2 cohen's d 2.63 0.12 0.78 p (lsd) 0.006 0.85[ns] 0.11[ns] table 3: descriptive data of transverse strength test (mpa) study groups (concentration of added agno3 in ppm) control 9.375 ppm 15 ppm 30 ppm range (74.4 to 81.6) (57.6 to 67.2) (56.4 to 72) (60 to 74.4) mean 77.8 63.8 67.0 66.4 sd 2.78 3.83 5.65 5.76 se 1.13 1.56 2.31 2.35 n 6 6 6 6 difference in mean compared to control reference -14.0 -10.8 -11.4 cohen's d reference -4.18 -2.42 -2.51 p (lsd) reference <0.001 0.001 <0.001 table 4: descriptive data of transverse strength test (mpa) study groups (concentration of added agno3 in ppm) 60 ppm 120 ppm 150 ppm p (anova range (58.5 to 79.2) (48 to 57.6) (57.6 to 76.8) <0.001 mean 64.8 55.4 69.6 sd 7.37 3.75 6.57 se 3.01 1.53 2.68 n 6 6 6 difference in mean compared to control -13.0 -22.4 -8.2 cohen's d -2.33 -6.77 -1.61 p (lsd) <0.001 <0.001 0.012 j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 82 table 5: descriptive data of tensile strength test (mpa) study groups (concentration of added agno3 in ppm) control 9.375 ppm 15 ppm 30 ppm range (49.54 to 62.5) (46.06 to 55.2) (39.71 to 57.8) (38.84 to 53.7) mean 54 49 51.9 44 sd 4.82 3.3 6.64 5.18 se 1.97 1.35 2.71 2.12 n 6 6 6 6 difference in mean compared to control reference -5.0 -2.1 -10.0 cohen's d reference -1.21 -0.36 -2.00 p (lsd) reference 0.05[ns] 0.42[ns] <0.001 table 6: descriptive data of tensile strength test (mpa) study groups (concentration of added agno3 in ppm) 60 ppm 120 ppm 150 ppm p (anova) range (31.48 to 41.69) (38.25 to 43.4) (38.3 to 45.56) <0.001 mean 36.8 40.7 41.5 s d 3.37 2.1 3.34 se 1.38 0.86 1.36 n 6 6 6 difference in mean compared to control -17.2 -13.3 -12.5 cohen's d -4.13 -3.58 -3.01 p (lsd) <0.001 <0.001 <0.001 control 9.37 15 30 60 120 150 300 600 900 ppm fig. 1: agno3 –loaded resinsfrom left to right: control, (9.375, 15, 30, 60, 120, 150, 300, 600, and 900 ppm). j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 83 wave number (cm-1) 2-pmma in kbr disc 3agno3-loaded resin in kbr disc 4-pmma in csi disc 5agno3-loaded resin in csi disc fig. 2: ftir spectrum discussion visual inspection of agno3 – loaded resin samples it is believed that the discoloration for agno3 loaded resins which was observed at 300 ppm agno3 and above as illustrated in figure (1) was due to the presence of metal oxides from antibacterial metal ions during an oxidation reduction reaction that occurs during a polymerization reaction, as well as the oxidation of the silver ions on the material surface 14,15. it was also reported that by adding such antibacterial agent, due to the ag+ in it, the color tone of the denture base resin varies16. characterization of agno 3-loaded resins since there is no change in the shape of absorption peaks between pmma(control) and agno3 – loaded resin samples as illustrated in the results of ftir figures(2-3-4-5) thus there is no chemical bond between the pmma and agno3 22. impact strength test the results of impact strength for the different concentrations of agno3 shows in significant increase in impact strength (p= 0.05 ns) when compared with control as shown in table (12).the 60ppm agno3 was associated the highest increase in impact strength by 2.2kj/ m 2 .this t ransm ittance t % j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 84 could be due to the slow curing process allows greater number of nucleation sites to form and smaller particle sizes, thereby generating more particles 2, the total particle / matrix interfacial surface area available for energy dissipation increase, the critical stress for particle /matrix debonding also increase 17. also the increasing in the impact strength could be due to the presence of residual monomer 18,16. this plasticizing effect render the fabricated acrylic resin samples more capable to absorb energy on impact and are more resistant to fracture13. the result of this study disagrees with casemiro et al. 8 who added (2.5-10%) by wet agzeolite as a powder to acrylic dental resin resulted decrease in impact strength. transverse strength and tensile strength tests among the specimens fabricated, the addition of silver nitrate in different concentrations reduces tensile strength (above 15 ppm agno3) as shown in table (5-6) and transverse strength table (3-4) when compared with control as the concentration of silver nitrate increased, this is probably due to ag+ ions being reduced as the concentration of ag increase, generating atom clusters and smaller particle size during the curing process which compete with complete polymerization process2. the plasticization effect of the resultant residual monomer will reduce the molecular binding force. on the other side, the results of ftir figures (23-4) showed no chemical bonding between pmma and agno3.therefore we suppose that ag+ ions attack the double bond in the alkene group of the monomer molecule and will convert it to residual monomer 18. this process will reduce the molecular binding force between the reactant molecules and allows greater deformation upon stretching or flexion through exhibiting multiple micro fractures that weaken the agno3 – loaded resin samples 19,20. some other studies also showed that adding an antibacterial agent may affect the material properties, kuroki et al. 16 have reported that there were significant differences of residual monomer in the samples treated by adding antimicrobial agents (zeomic, bactekiller, novaron) although it was insignificant between the control and samples. fan et al. 2 found that by adding 0.15% (w/w) agbz (silver benzoate) and above there was decrease in the degree of curing, result in reduction in rockwell hardness for light cure resin. nakanoda et al. 14 have reported that, as a result of tensile tests and bending tests, adding silver-zeolite to a heat-curing resin tends to decrease the material property depending on the additive concentrations of antibacterial agent of zeomic. there was in significant reduction in tensile strength with the lowest concentrations of agno3 (9.375 and 15ppm) compared with control as shown in table 5. this outcome is in agreement with wakasa et al. 21 who reported that when the antimicrobial agent (zeomic) is added to self – cure acrylic resin between 1% and 2%, the polymerization behavior of the resin is not inhibit. references 1. keng sb, lim m. denture plaque distribution and the effectiveness of a perborate –containing denture cleaners .quintessence int 1996; 27: 341-345. 2. fan c, chu l, h ralph rawls, norling bk, cardenas h, whang k. development of antimicrobial resin –a pilot study. j dental mater 2011; 27:322-8. 3. russell ad, hugo wb .antimicrobial activity and action of silver. progress in medical chemistry 1994; 31: 351-70. 4. lansdowne ab, williams s channdler, benfield s. bacterial resistance to silver in wound care and medical devices. j wound care 2007; 16(1): 15-19. 5. hottal m, nakajima h, yamamoto k, aono m. antibacterial temporary filling materials: the effect of adding various ratio of ag-zn-zeolite. j oral rehabil 1998; 25(7): 485-9. 6. yoshida k, tanagawa m, atsuta m. characterization and inhibitory effect of antimicrobial dental resin composites incorporating silver –supported materials. j biomed mater res 1999; 47: 516-22. 7. kawashita m, tsuneyamas, miyagif kk. antibactrerial silver-containing silica glass prepared by sol –gel method. biomaterials 2000; 21(4): 393-8. 8. casemiro la, gomes martins ch, panzeri fc, pires de –souza, panzeri h. antimicrobial and mechanical properties of acrylic resin with incorporated silverzinc zeolite –part one. gerodontology 2008; 25: 18794. 9. yu ry, zhou y.s, feng hl. silver ion release and particle distribution of denture base resin containing nanometer-sized silver –supported antimicrobial agent. zhonghua kou qiang yi xue za zhi 2008; 43:54-56. 10. iso 179-1. international organization for standardization. plastic determination of charpy impact propertiespart 1: non-instrumented impact test 2000. 11. ada, american dental association / american material standers institute, specification no.12 for denture base polymer. chicago council on dental matewrials and devices 1999. 12. iso 527. international organization for standardization. plastic determination of tensile properties 1993. 13. anusavice kj. philip's science of dental materials. st. louis: elsevier ltd; 2008. p. 211,220,235,237,271. 14. nakanoda s, nikawa h, hamada t, yamamoto t, nakamoto k .the material and antifungal properties of antibiotic zeolite incorporated acrylic resin. j jpn prosthodont soc 1995; 39: 919-26. j bagh college dentistry vol. 26(4), december 2014 effect of silver nitrate restorative dentistry 85 15. yutani h, yamamotok .the antibacterial effect of glass ionomer cement containing ag silica glass. jpn j conserv dent 2002; 45: 441-9. 16. kuroki k, hayashi t, sato k, asai t, okano m, kominami y, takahashi y, kawai t. effect of selfcured acrylic resin added with an inorganic antibacterial agent on streptococcus mutans.dent mater j 2010; 29(3): 277–85. 17. chen j, huang z, zhu j .size effect of particles on the damage dissipation in nanocomposites. compos sci technol 2007; 67(14):29906. 18. cope ac, bach rd. trans –cyclooceten. organic syntheses, collected 1973; volume 5:p. 315; vol.49:p.39. 19. jagger rg. effect of curing cycle on some properties of a polymethylmethacrylate denture base material. j oral rehabil 1978; 5: 151–7. 20. jerolimov v, huggett r, brooks cs, bates jf. the effect of the variations in the polymer/monomer mixing ratios on residual monomer levels and flexural properties of denture base materials. quintessence int 1985; 9: 431–434. 21. wakasa k, yosida y, nomura y, ikeda a, nakatsuka a,ogino s, matsui h, shirai k, yoshioka m, yamaki ma. fundamental study on dental application of silver zeolite. j hiroshima univ dent soc 1997; 29: 87-98. 22. singho nd, lah nac, johan mr, ahmed r. ftir studies on silver –poly(methylmethacrylate) nanocomposites via in-situ polymerization technoque. int j elechtrochem sci 2012; 7: 5596-603. taif.doc j bagh college dentistry vol. 27(2), june 2015 evaluation of the oral and maxillofacial surgery and periodontics 130 evaluation of the effectiveness of coenzyme q10 gel in management of patients with chronic periodontitis (i intra group comparison) taif m. salih, b.d.s. (1) maha sh. mahmood, b.d.s., m.sc. (2) abstract background: periodontal pathogens can induce free radicals over-formation and thus may cause collagen and periodontal destruction. anti-oxidants are used as supplements to counteract the over production of free radicals in periodontal disease, that can reduce of collagen destruction. coenzyme q10 serves as an endogenous antioxidant, regenerates other antioxidants, stimulates cell growth, and inhibits cell death. because it is an antioxidant, coenzyme q10 has received much research attention associated with periodontal diseases. perio q gel may possibly be effective as a topical agent and as an adjunct to scaling& root planing in treatment of gingivitis and chronic periodontitis. aim of study:determine the periodontal health status in a follow up study for 6 weeks of a group of patients with chronic periodontitis by measuring clinical periodontal parameters, which included (plaque index, gingival index, bleeding on probing, probing pocket depth and relative attachment level) and to evaluate the effect of intra pocket application of perio q gel (coenzyme q10) alone & as adjunct to scaling,& root planing on the periodontal clinical parameters in the management of patients with chronic periodontitis. materials and methods: a total of 323 sites with pocket depth (5-8) mm in patients with chronic periodontitis were randomly divided in three groups. the gel group, 111 sites were treated with intra-pocket application of perio q gel alone. in the combination group, 106 sites were treated with scaling and root planning (srp) plus intrapocket application of perio q gel, in scaling and root planing group, 106 sites were treated with scaling and root planing alone. clinical periodontal parameters such as plaque index (pi), gingival index (gi), bleeding on probing (bop), probing pocket depth (ppd), relative attachment level (ral) were assessed at first visit, 3weeks and 6weeks. results: on intra-group analysis, all groups showed highly significant reduction in pi, gi, bop, ppd and ral among the three visits .on inter-group analysis, the results showed significant reduction in the clinical parameters ppd and ral of combination group in comparison to srp group. conclusion: the results of the research were encouraging and suggested the possibility to use the gel as a sole agent to support standard treatment procedures in periodontitis. the clinical parameters significantly improved in the phase of periodontal treatment, indicating that coq10 opens new treatment options by improving the host response to disease activity. keyword: chronic periodontitis, antioxidants, coenzyme q10, perio q gel. (j bagh coll dentistry 2015; 27(2):130-135). introduction periodontitis is a silent disease. it is an inflammatory response caused by groups of specific microorganisms in which the structural support to the tooth is destroyed (1,2). the disease results in resorption of the alveolar bone, destruction of the periodontal ligament supporting the tooth and formation of a periodontal pocket with attachment loss. the pocket provides an ideal environment for the proliferation of a variety of pathogenic bacteria (3). successful periodontal treatment is dependent on anti-inflammatory procedure, which includes both mechanical (scaling polishing along with plaque control measures or surgical methods) and chemotherapeutic approach (4). chemotherapeutic approach includes local application or sustained release of local drug delivery agents and systemic approaches. (1) master student. department of periodontics, college of dentistry, university of baghdad. (2) professor, department of periodontics, college of dentistry, university of baghdad. the local delivery therapy to periodontal pockets has the benefit of putting more drug at target site while minimizing exposure of total body to the drug (5). locally delivered antioxidant agents are administered to disinfect the root surface and adjacent periodontal tissues and reduction of pocket formation. they are designed to enhance the healing following periodontal therapy (6). controlled release delivery of antioxident directly into periodontal pockets has received eminent interest and appears to hold a levelheaded promise in periodontal therapy. it does not substitute conventional mechanical debridement but acts as an adjunct to it. the periodic use of local drug delivery in improving gingival and periodontal condition, would allow better control and management of periodontal disease (7). antioxidant material such coenzyme q10 is a fat-soluble quinone found in all cells in the body (8). primary biochemical action of coq10 is a powerful antioxidant that prevents the generation of harmful free radicals that attack the body’s defenses and also prevent modifications of proteins, lipids, and dna (9).coenzyme q10 play j bagh college dentistry vol. 27(2), june 2015 evaluation of the oral and maxillofacial surgery and periodontics 131 critical role in the generation of (atp adenosine tri-phosphate) the essential component of energy in the body (10-12). also it has a bonus effect with significant reduction of motile rods and spirochetes .particularly affects the cells of that are most metabolically active: heart, immune system, gingival and gastric mucosa .research has found it beneficial for cancer, gastric ulcer, aging, physical performance, periodontal disease, muscular disease, neurodegenerative disorders and cardiovascular disease (13). for all these functions it’s used for intrapockets application as gel form called (perio q gel) solitary and also additive with scaling and root planing for the treatment of chronic periodontitis thus, opening new treatment options. the gel is easily prepared and administered. moreover, they possess a higher biocompatibility and bioadhesivity, allowing adhesion to dental pocket tissues and finally, they can be rapidly eliminated through bloodstream, decreasing the irritation or allergic host reactions in the application site (14),so it have additional activity because of its functions and its form(gel). according to the best of our knowledge, few studies evaluate the clinical effectiveness of this gel as a mono therapy &as adjunct to scaling &root planning in the management of patients with chronic periodontitis, so itwas decided to conduct this study. materials and methods human sample the total patients number was (15), both genders, with an age range (35-55). inclusion criteria: systemically healthy patients, at least had 20 teeth, the patients had chronic periodontitis with at least 4 sites with pocket depth equal or greater than 4mm with clinical attachment loss of 1-2 mm or greater (15). exclusion criteria: pregnant and lactating women, smokers, patients received periodontal treatment and used antibiotics or antiinflammatory medications in the last3months. the aims and purposes of the study were well explained to the patients so they participated voluntarily in the period between april to the beginning of july 2014. study design a total of 323 sites of the probing depth (5-8) mm were included in the study. each patient mouth splitted into three quadrants, each quadrant should have at least 4 pocket sites of (5-8) mm depth. the selected sites were divided into three groups according to the different treatment modalities: gel group: these sites treated with intrapocket application of perio q gel only without any deep scaling or root planing. combination group: these sites treated by both: intra-pocket application of perio q gel with scaling and root planing. scaling and root planning group: these sites treated with scaling and root planing alone periodontal examinations were performed before and after three and six weeks after the beginning of the experiment. periodontal assessments were performed using the plaque index (pli) (16), gingival index (gi) (17), bleeding on probing (bop) (15), probing pocket depth (ppd) (18) and relative attachment level (ral). treatment: first, of all an alginate impression was taken and an occlusal stent was constructed for each patient.for the three groups the initial visit (1st day) included patient selection, supra gingival scaling, alginate impression, motivation and instruction. gel group received intra pocket application of perio q gel only. the selected sites were isolated by cotton rolls, dried the teeth by air, and then dried the pockets by paper point size (30, 35, 40, and 45). the application of the gel was made using disposable syringe of 5ml. the sharp tip of needle was removed by rotary bur to avoid hurting the gingival tissue and smoothened it,then 1 ml of the gel was pulled by the syringe and the needle gently placed down through the pocket then placed the gel.each pocket was received a range of (0.1-0.3) ml., the excess gel oozing from the pockets was removed .the patients were instructed to avoid spitting, washing, eating and drinking for 2 hours of the gel application. toothbrush and interdental aids should paused of the day after the gel application. combination group: 106 sites in this group received deep scaling and root planing, then after one hour, the patient examined if there was no blood oozing, then the gel applied as was described previously. if not, the patient was referred to the next day. scaling and root planning group: received scaling and root planning only. data collected after 3weeks and 6weeks. data obtained after treatment was compared with the initial values. results were expressed as mean ± sd and median for bleeding on probing,t –test &wilcoxon signs rank test (wsr) were used j bagh college dentistry vol. 27(2), june 2015 evaluation of the oral and maxillofacial surgery and periodontics 132 where indicated. the level of significance was 0.05. results intra-group comparison: gel group reduction of mean values of clinical periodontal parameters plaque index, gingival index, probing pocket depth and relative attachment level in gel groupamong 3 visits with highly significant differences among three visits of p values (0.00) (table 1).bleeding on probing ingel groupamong 3 visits showed highly significant differences among three visits of p values (0.01) (table 2). combination group reduction of mean values of clinical periodontal parameters plaque index, gingival index, probing pocket depth and relative attachment level in combination group among 3 visitswithhighly significant differences among three visits of p values (0.00)(table 3).bleeding on probing in combination group among 3 visits showed highly significant differences among three visits of p values (0.01) (table4). scaling and root planing group reduction of mean values of clinical periodontal parameters plaque index, gingival index, probing pocket depth and relative attachment level in scaling and root planing group among 3 visits withhighly significant differences among three visits of p values (0.00) (table 5). bleeding on probing of scaling and root planing group among 3 visits showed highly significant differences among three visits of p values (0.01) (table 6). table 1: intra-group comparison of (plaque index, gingival index, probing pocket depth and relative attachment level) gel group among the 3visits variables visits descriptive statistics 1 st vs. 2nd 1st vs. 3rd 2nd vs. 3rd mean s.d. min. max. t-test p-value t-test p-value t-test p-value pi 1st 1.80 0.33 1 2.1 5.737 0.000 (hs) 10.08 0.000 (hs) 5.45 0.000 (hs) 2 nd 1.33 0.37 0.83 2 3rd 0.98 0.29 0.5 1.6 gi 1st 1.99 0.05 1.83 2.09 10.272 0.000 (hs) 13.318 0.000 (hs) 6.984 0.000 (hs) 2 nd 1.59 0.17 1.25 2 3rd 1.25 0.24 1 1.63 ppd 1st 6.75 0.68 5.8 7.8 8.024 0.000 (hs) 13.066 0.000 (hs) 10.313 0.000 (hs) 2 nd 6.23 0.61 5.5 7.3 3rd 5.59 0.62 4.6 6.7 ral 1st 7.74 0.68 6.8 8.9 7.965 0.000 (hs) 13.244 0.000 (hs) 10.629 0.000 (hs) 2 nd 7.23 0.61 6.5 8.4 3rd 6.58 0.62 5.6 7.8 table 2: intra-group comparison of bleeding on probing in gel group among the three visits visits descriptive statistics 1 st vs. 2nd 1st vs. 3rd 2nd vs. 3rd median wsr p-value wsr p-value wsr p-value 0 1st 0 -3.315 0.001 (hs) -3.417 0.001 (hs) -3.322 0.001 (hs) 2 nd 2.7 3rd 4.5 1 1st 6.3 -3.329 0.001 (hs) -3.419 0.001 (hs) -3.314 0.001 (hs) 2 nd 3.6 3rd 2 j bagh college dentistry vol. 27(2), june 2015 evaluation of the oral and maxillofacial surgery and periodontics 133 table 3: intra-group comparison (pli, gi, ppd and ral) of combination group among the 3visits variables visits descriptive statistics 1 stvs. 2nd 1stvs. 3rd 2ndvs. 3rd mean s.d. min. max. t-test p-value t-test p-value t-test p-value pi 1st 1.83 0.23 1.5 2 9.272 0.000 (hs) 16.598 0.000 (hs) 5.682 0.000 (hs) 2 nd 1.41 0.31 1 2 3rd 1.02 0.20 0.6 1.4 gi 1st 1.98 0.06 1.75 2 9.265 0.000 (hs) 13.460 0.000 (hs) 6.615 0.000 (hs) 2 nd 1.56 0.17 1.3 1.8 3rd 1.20 0.23 1 1.75 ppd 1st 6.20 0.62 5.5 7.75 10.974 0.000 (hs) 11.182 0.000 (hs) 6.071 0.000 (hs) 2 nd 5.67 0.60 5.16 7.25 3rd 5.19 0.71 4.25 6.87 ral 1st 7.20 0.62 6.5 8.89 11.138 0.000 (hs) 11.275 0.000 (hs) 6.180 0.000 (hs) 2 nd 6.67 0.60 6.16 8.4 3rd 5.75 0.71 5.25 7.98 table 4: intra-group comparison of bleeding on probing in combination group among the three visits visits descriptive statistics 1 stvs. 2nd 1stvs. 3rd 2ndvs. 3rd median wsr p-value wsr p-value wsr p-value 0 1st 0 -3.436 0.001 (hs) -3.425 0.001 (hs) -3.191 0.001 (hs) 2 nd 2.8 3rd 5.6 1 1st 5.6 -3.424 0.001 (hs) -3.425 0.001 (hs) -3.191 0.001 (hs) 2 nd 3.7 3rd 0.9 table 5: intra-group comparison (pli, gi, ppd and ral) of scaling and root planing group among the 3visits variables visits descriptive statistics 1 stvs. 2nd 1stvs. 3rd 2ndvs. 3rd mean s.d. min. max. t-test p-value t-test p-value t-test p-value pi 1st 1.94 0.13 1.57 2 15.194 0.000 (hs) 24.967 0.000 (hs) 7.876 0.000 (hs) 2 nd 1.42 0.19 1 1.6 3rd 1.09 0.18 0.7 1.4 gi 1st 1.98 0.13 1.57 2.2 7.685 0.000 (hs) 16.030 0.000 (hs) 6.503 0.000 (hs) 2 nd 1.54 0.22 1.25 2 3rd 1.18 0.17 1 1.42 ppd 1st 6.40 0.66 5.2 7.28 9.572 0.000 (hs) 9.309 0.000 (hs) 5.701 0.000 (hs) 2 nd 6.10 0.61 4.6 6.7 3rd 5.75 0.62 4.2 6.25 ral 1st 7.50 0.66 6.2 8.4 9.774 0.000 (hs) 9.266 0.000 (hs) 5.635 0.000 (hs) 2 nd 7.05 0.61 5.6 7.8 3rd 6.75 0.61 5.2 7.3 table 6: intra-group comparison of bleeding on probing in scaling and root planing group among the three visits visits descriptive statistics 1 stvs. 2nd 1stvs. 3rd 2ndvs. 3rd median wsr p-value wsr p-value wsr p-value 0 1st 0 -3.320 0.001 (hs) -3.420 0.001 (hs) -3.448 0.001 (hs) 2 nd 2.8 3rd 4.7 1 1st 5.6 -3.301 0.001 (hs) -3.419 0.001 (hs) -3.438 0.001 (hs) 2 nd 2.8 3rd 1.9 j bagh college dentistry vol. 27(2), june 2015 evaluation of the oral and maxillofacial surgery and periodontics 134 discussion the concept of antioxidant therapy in the treatment of numerous diseases including inflammatory periodontal disease exists in the literature. because of its function, coq10 has received much research attention in a medical literature in the last several years. however, there is a dearth of new information regarding coq10 in the treatment of periodontal conditions (10). gel group &clinical periodontal parameters there was a reduction in the scores of plaque index among the 3 visits with a highly significant differences, this may indicate that the patients maintained their oral hygiene over the period of time of the study. also there was a highly significant differences improvement seen in terms of decrease in gingival index scores values and this may indicate the added advantage of coenzyme q10 gel, in addition to maintaining good plaque control. a highly significant difference was observed in bleeding on probing sites with reduction of bleeding sites among the 3 visits of gel treatment and this could be attributed to that coq10 serves as an endogenous antioxidant, and its increased concentration in the diseased gingiva effectively suppresses advanced periodontal inflammation. also when reactive oxygen species (ros) are scavenged by antioxidants like coq10; there can be a reduction of periodontal collagen degradation (19). it was shown a reduction in probing pocket depth and relative attachment levelwhich may be due to the antioxidant action and the cumulative effects of coq10 as an immune enhancer and accelerates tissue healing (2022).healing and repair of periodontal tissue requires efficient energy production, and the metabolic functions of the periodontal tissues depend on an adequate supply of coq10, which act as a cofactor in the oxidative phosphorylation production of adenosine triphosphate (atp)(23). atp provides the energy for muscle contraction and other vital cellular functions. the major part of atp production occurs in the inner membrane of mitochondria where coenzyme q10 is found (24). this is accordance with many studies (25,26) &similar results have been reported by others (10,23,27-30) combination group & clinical periodontal parameters there was a reduction in the plaque index, gingival index and bleeding on probing scores among the 3 visits with a highly significant differences, this could be related to scaling and root planing that remove all deposits from pockets &eliminate the bacteria with a bonus effect of coq10 of significant reduction of motile rods and spirochetes (31).combination between these two effects may reduce the inflammation. a highly significant difference &reduction showed in result of probing pocket depth and relative attachment level. a deficiency of coenzyme q10 in the gingival tissue may exist independently of and/or because of periodontal disease. if a deficiency of coenzyme q10 existed in the gingival tissue for nutritional causes and independently of periodontal disease, then the advent of periodontal disease could enhance the gingival deficiency of coenzyme q10. in such patients, oral dental treatment and oral hygiene procedures can remove the local factors only but cannot correct the deficiency of coq10 due to systemic cause. thus, mechanical periodontal therapy along with the adjunctive use of coq10 can be included for an overall improvement of the gingival health in periodontal disease (32,9). this result agree with other findings (25,26). & similar results have also been reported by others (10,23,27-30) scaling &root planning group scaling & root planing is one of the most commonly used procedures for the treatment of periodontal diseases and it is considered as the gold standard therapy in comparison to other therapeutical procedures. the results of this study showed that there was a highly significant reduction in the scores of plaque index, gingival index, bleeding on probing,probing pocket depth and relative attachment level among the 3 visits. these reductions in the clinical periodontal parameters may be due to that scaling is the process by which plaque and calculus are removed from both supra gingival and sub gingival tooth surfaces, while root planing is the treatment procedure that is designed to remove cementum or surface dentin that is rough, impregnated, with calculus or contaminated with toxins or microorganisms. therefore, it will results in elimination of disease and return the supporting structures of the teeth to a healthy state. this was in agreement with these studies (10,19,23,33). as conclusion; the results of the research were encouraging and suggested the possibility to use j bagh college dentistry vol. 27(2), june 2015 evaluation of the oral and maxillofacial surgery and periodontics 135 the gel as a sole agent to support standard treatment procedures in periodontitis. the clinical parameters significantly improved in the phase of periodontal treatment, indicating that coq10 opens new treatment options by improving the host response to disease activity. intra-pocket application of perio q gel alone and as adjunct with mechanical debridement and mechanical debridement alone were improved the clinical periodontal parameters. references 1. canakci cf, canacki v, tatar a, et al. increased levels of 8-hydroxyguanosine and malondialdehyde and its relationship with antioxidant enzymes in saliva of periodontitis patients. eur j dent 2009; 3:100-6. 2. dhotre ps, suryakar an, bhogade rb. oxidative stress in periodontitis. eur j gen med 2012; 9(2): 81-84. 3. greenwell h, bissada nf. emerging concepts in periodontal therapy. drugs 2002; 62(18): 2581-7. 4. prabhushankar gl, gopalkrishna b, manjunatha km, girisha ch. formulation and evaluation of levofloxacin dental gel films for periodontitis. int j pharm pharm sci 2010; 2(1):162-8. 5. raheja i, kohli k, drabu s. periodontal drug delivery system containing antimicrobial agents. int j pharm pharm sci 2013; 5(3): 11-16 6. malathi k, jeevarekha m, premblaisierajula m, singh a. local drug delivery –a targeted approach. international journal of medicine and biosciences int j med biosci 2014; 3(2): 2934. 7. ashtaputre v, limaye m. local drug delivery in periodontics: a tactical entreaty. j res pharmaceutical sci 2014; 2(1): 6-11. 8. molyneux sl, florkowski cm, george pm, pilbrow ap, frampton cm, lever mr. coenzyme q10 an independent predictor of mortality in chronic heart failure. j the american college of cardiology jacc 2008; 52(18):1435–41 9. saini r. a clinical and microbiological study to evaluate the effect of dietary supplement of coenzyme q10 in nonsurgical treatment outcome of chronic periodontitis patients after phase 1 periodontal therapy. european j general dentistry 2014; 3(3):194-8. 10. chatterjee a, kandwal a, singh n and singh a. evaluation of co-q10 antigingivitis effect on plaque induced gingivitis: a randomized controlled clinical trial. j indian soc periodontol 2012; 16(4): 539–42. 11. sanadi rm. clinical evaluation of co-q-dent in aggressive periodontitis patients. jpbms 2012; 17 (13):1-3. 12. soni s, agrawal pk, sharma n&chander s. coenzyme q10 and periodontal health: a review, inter j oral maxillofac pathol 2012; 3(2): 21-6. 13. chaturvedi r. idiopathic gingival fibromatosis associated with generalized aggressive periodontitis: a case report. j can dent assoc 2009; 75: 291-95. 14. kaplish v, kaur m, walia -kumar slh. local drug delivery systems in the treatment of periodontitis: a review. pharmacophore 2013; 4(2): 39-49. 15. newman mg, takei h, klokkevold pr, carranza fa. carranza’s clinical periodontology. 11th ed. philadelphia: saunders; 2012. 16. silness j, loe h. periodontal disease in pregnancy. ii. correlation between oral hygiene and periodontal condition. acta odontol scand 1964; 22:112-35. 17. löe h. the gingival index, the plaque index and the retention index systems. j periodontol 1967; 38(6): 610-6. 18. lindhe j, karring t, lang n. clinical periodontology and implant dentistry. 3rd ed. copenhagen, munksgaard; 1998 19. pitale u, khetarpal s, peter k, pal v, verma e, gupta p. evaluation of efficacy of coenzyme q10 in management of gingivitis &slight periodontities-a clinical study. int j curr pharm res 2012; 4(4): 33-8. 20. segelnick sl, weinberg ma. reevaluation of initial therapy when is the appropriate time. j periodontol 2006; 77(9):1598-601. 21. cianco n, giannopoulou c, ugolotti g, mombelli a. amoxicillin and metronidazole as an adjunct to fullmouth scaling and root planing of chronic periodontitis. j periodontol 2009; 80(3):364-71. 22. zaki nm. site-specific delivery of the nutraceutical coq10 for periodontal therapy. inter j pharmacy pharmaceutical sci int j pharm pharm sci 2012; 4(2): 717-23. 23. hans m, prakash s, gupta s. clinical evaluation of topical application of perio-q gel (coenzyme q10) in chronic periodontitis patients. j indian soc periodontol 2012; 16(2): 193–9. 24. crane fl. biochemical functions of coenzyme q10. journal of the american college of nutrition 2001; 20: 591-8. 25. wilkinson eg, arnold rm, folkers k, hansen i, kishi h. bioenergetics in clinical medicine ii. adjunctive treatment with coenzyme q in periodontal therapy. res commun chem pathol pharmacol 1975; 12:111–23. 26. wilkinson eg, arnold rm, folkers k. bioenergetics in clinical medicine vi adjunctive treatment of periodontal disease with coenzyme q10. res commun chem pathol pharmac 1976; 14: 715-9. 27. mcree jt, hanioka t, shizukuishi s, folkers k. therapy with coenzyme q10 for patients with periodontal disease. j dent health 1993; 43: 659–66. 28. matthews-brzozowska t, kurhañskaflisykowska a, wyganowska-oewitkowska m, stopa j. healing of periodontal tissue assisted by coenzyme q10 with vitamin e– clinical and laboratory evaluation. pharmacol reports 2007; 59(suppl 1): 257–60. 29. chaudhry s, vaish s, dodwad v, arora a. natural antioxidant: coenzyme q10 (perio q) tm in management of chronic periodontities: a clinical study. int j dent health sci 2014; 1(4): 475-84. 30. sale st, parvez h, yeltiwar rk, vivekanandan g, pundir aj and jain p. a comparative evaluation of topical and intrasulcular application of coenzyme q10 (perio q™) gel in chronic periodontitis patients: a clinical study. j indian soc periodontol 2014; 18(4): 4615. 31. denny n, chapple il, matthews jb. antioxidant and anti-inflammatory effects of coenzyme q10: a preliminary study. j dent res 1999; 78: 543. 32. prakash s, sunitha j, hans m. role of coenzyme q10 as an antioxidant and bioenergizer in periodontal diseases. indian j pharmacol 2010; 42(6): 334-7. 33. figuero e, soory m, cerero r, bascones a. oxidant/antioxidant interactions of nicotine, coenzyme q10, pycnogenol and phytoestrogens in oral periosteal fibroblasts and mg63 osteoblasts. steroids 2006; 71:1062–72. j bagh college dentistry vol. 33(4), december 2021 salivary cortisol as 6 salivary cortisol as a stress biomarker and total viable count of salivary bacterial microbiome among covid-19 patients hind h. enad (1), abbas s. al-mizraqchi (2) https://doi.org/10.26477/jbcd.v33i4.3013 abstract background: the covid-19 virus outbreak had a massive effect on many parts of people's lives, as they were advised to quarantine and lockdown to prevent the virus from spreading, which had a big impact on people's mental health, anxiety, and stress. many internal and external factors lead to stress. this negatively influences the body's homeostasis. as a result, stress may affect the body's capacity to use energy to defend against pathogens. many recent investigations have found substantial links between human mental stress and the production of hormones, prohormones, and/or immunological chemicals. some of these researches have verified the link between stress and salivary cortisol levels. the aim of this study is to measure salivary cortisol as a stress biomarker as well as a total viable count of salivary bacterial microbiome among covid-19 patients. materials and methods: a sample of 84 adults patients was collected who were divided into two groups: the covid-19 group consists of 42 patients and the covid-19 free group which consists of 42 subjects. all subjects undergo a pcr test to confirm their health status. the collection of un-stimulated saliva was done. laboratory investigations were carried out to measure the total viable count of the salivary bacterial microbiome by culturing on brain heart infusion agar and to evaluate the salivary cortisol level using cortisol kit (elecsys cortisol ii). results: spss version 21 was used for statistical analysis. according to the statistical analysis, the salivary cortisol and total viable count of salivary bacterial microbiome values were substantially greater in the covid-19 group than in the covid-19 free group. conclusion: a positive association was found between salivary cortisol and the total viable count of the salivary bacterial microbiome. so, when the concentration of salivary cortisol is elevated in the covid-19 group, the level of the total viable count of the salivary bacterial microbiome is also elevated. keywords: cortisol, covid-19, stress, biomarker, oral bacteria. (received: 22/7/2021, accepted: 11/9/2021) introduction stress is described as a set of physiological and psychological responses that activate a person's defense mechanism in response to a range of threats. in reaction to stress, the hypothalamuspituitary-adrenal (hpa) axis is predominantly stimulated. (1) there are several techniques to stress management in humans and animals, many of which rely on the quick identification of damage induced primarily by stress and are referred to as biomarkers. (2) the stress indicators show that the individual is disturbed and exerts a lot of energy to maintain homeostasis. (3) a biomarker is an indicator used to assess the pathologic and physiologic condition of the individual. (4) (1) master student, al hadi university college, dentistry department. baghdad, iraq. (2) professor, department of basic sciences, college of dentistry, university of baghdad. corresponding author, prof.almizraqchi@yahoo.com. according to the fda, an ideal biomarker should be easily tested, capable of distinguishing between different disorders, safe and harmless, and specific for certain pathological and physiological conditions. (5) stress biomarkers might be hormones such as adrenaline and cortisol, enzymes such as alpha-amylase and lysozyme, proteins such as secretory iga, or prohormones such as chromogranin a. (6) many studies have suggested that there is a substantial link between stress and various saliva components such as cortisol, siga, a-amylase, and cga. (7) cortisol is a steroid hormone synthesized by the zona fasciculata of the adrenal cortex, and it is the most investigated component in saliva as a stress indicator. (8) salivary cortisol is found in a free, unbound form and correlates with unbound blood plasma cortisol. it is lipophilic and requires a carrier which is usually a protein for traveling around the body. the protein binds the majority of cortisol (65%) in blood plasma. approximately 70% of unbound blood cortisol is a salivary https://doi.org/10.26477/jbcd.v33i4.3013 j bagh college dentistry vol. 33(4), december 2021 salivary cortisol as 7 cortisol concentration, only 1 to 15% of cortisol in the blood is in its unbound or biologically active form. the cortisol that remains is bound to serum proteins. (9) cortisol levels rise in response to physical or mental stress, and they are influenced by workload and sleep deprivation. the highest cortisol concentrations were found 45-60 minutes after waking up, and the lowest concentrations were found in the evening hours, which corresponds to variations in plasma cortisol. (10) the salivary analysis is less invasive than blood sampling, which can be uncomfortable and artificially elevate cortisol levels. (11) stressinduced elevations in cortisol have two main effects: they release glucose, which is required for giving energy to organs, and they mediate changes in immunity, which are crucial for restoring physiological equilibrium. (12) microorganisms live on the surface tissues of all humans, including the skin, oral cavity, respiratory system, gastrointestinal tract, and urogenital tract. the amount and kind of microorganisms a person possesses vary according to age, diet, and personal hygiene level. they are known as the human body's normal microbiome. (13) bacteria have been thought to be the most relevant component of the human microbiome. (14) the human oral microbiome had about 600 predominant bacterial taxa, with various subsets predominating at multiple surfaces such as teeth, gingival sulcus, tongue, cheeks, hard/soft palate, and tonsils. (15) the two types of tissues in the oral cavity that bacteria colonize are soft and hard tissues. it is also clear that the oral cavity has a number of different bacterial growth niches, each with its unique bacterial profile that varies by location and individual, based on lifestyle and physiological variations, each individual has a specific microbiome. (16) streptococcus, veillonella, porphyromonas, rothia, actinomyces, corynebacterium, treponema, fusobacterium, prevotella, neisseria, eikenella, haemophilus, lactobacterium, eikenella, leptotrichia, peptostreptococcus, staphylococcus, eubacteria and propionibacterium, according to a research findings done by zarco et al. (2012), are the main genera with the biggest presence in the oral cavity. the primary aim of the present study was to evaluate cortisol value in saliva to examine the presence of stress among covid-19 patients in comparison with healthy adults in the same period of time and under the same circumstances, measure the total viable count of salivary bacterial microbiome of covid-19 patients in comparison with covid-19 free group and evaluate the correlation between salivary cortisol and total viable count of salivary bacterial microbiome among covid-19 patients. materials and methods after the proposal and the revision of the study protocol, approval was obtained from the scientific and the ethics committee in college of dentistry/university of baghdad/iraq, the study lasted for 4 months from january until the end of april 2021. the samples were collected in dar altamreedh hospital in baghdad medical city in the morning from 9-11 o’clock. the inclusion criteria for this study were medically fit patients with no systemic diseases and a positive pcr test for covid-19 and recently infected (not more than 2 days) to ensure the good health of the patient who took no antibiotics that could alter the bacterial count. patients were excluded from this study if they had signs and symptoms of covid-19 but negative result on pcr tests also patients with positive pcr test on antibiotic treatment or on medications due to history of chronic disease. the patients were informed not drink or eat anything (excluding water) two hours before collecting the samples, saliva has been collected at the same time of day, 9-11 a.m. and fixed collection time (5 minutes). the amount of unstimulated saliva obtained was between 1-3 ml in test tube, and samples were collected under similar conditions to collect 84 samples from covid-19 patients and covid-19 free subjects. covid-19 free subjects have been used as a control group including 42 healthy adults of both genders, samples were collected from dar al-tamreedh hospital / pcr test center for travelers. after collecting the salivary sample from each patient, the tubes were placed in a cool box with ice to transfer them to the lab to be cultured within less than an hour. part of the saliva was centrifuged for 10 min at 3000 rpm, and the clear supernatant was collected and kept in the freezer at -20°c until use. the salivary cortisol level was determined by using the cortisol kit (elecsys cortisol ii) by cobas e 411 system and according to the manufacturer’s instructions and the results were expressed in μg/dl. the other part is used for culturing bacteria in brain heart infusion agar. tenfold serial dilution was prepared using j bagh college dentistry vol. 33(4), december 2021 salivary cortisol as 8 phosphate buffer solution, 0.1 ml was withdrawn by micropipette from the dilution (10⁻⁴, 10-6 ) then a microbiological spreader was used to inoculate the 0.1 ml on the brain heart infusion agar from each dilution after that an incubator was used to incubate the agars; the agars were incubated for 48 hours, at 37◦c and finally after incubation the total bacterial count cfu/ml was determined by the use of colony counter. these were the first calculated values after 48 hours from collecting each sample, while the cortisol levels were examined after completing all the samples collection to calculate all the values at the same circumstances. the impact of salivary cortisol and total viable count of salivary bacterial microbiome were determined using a statistical test (student’s ttest, simple linear regression, descriptive analysis included percentages or mean ± standard deviation sd) relied on spss program version 21, if the pvalue was <0.05 it was considered as statistically significant. results a total of 84 patients participated in this study, they were 52 males (62%) and 32 females (38%), they ranged in age from 20 to 55 years with a mean age of 34.6 years. according to the findings of the present study, salivary cortisol levels were significantly different between the two groups, the lower mean was found among covid-19 free group (0.62) compared to covid-19 group (0.68). also total viable counts of salivary bacterial microbiome levels were also significantly different between the patient and control group (p= 0.029), the lower mean was among covid-19 group free (42.28 x106) while covid-19 group mean value was (78.88 x 106) as shown in (table 1). table 1: salivary cortisol level (μg /dl) and total viable count of salivary bacterial microbiome (cfu/ml) between covid-19 group and covid-19 free group. [*] p>0.05 non significant [**] p<0.05 significant the statistical analysis showed that there was a positive correlation between salivary cortisol and total viable count of salivary bacterial microbiome levels in covid-19 group, the r value (0.214) while there is a negative correlation between salivary cortisol and total viable count of salivary bacterial microbiome levels, the r value (-0.21) as shown in (table 2). table 2: the correlation coefficient between salivary cortisol and total viable count of salivary bacterial microbiome in covid-19 and covid-19 free group. by using simple linear regression, a positive association was found between salivary cortisol and the total viable count of the salivary bacterial microbiome in covid-19 group. a negative association was found between cortisol and total viable count of the salivary bacterial microbiome in covid-19 free group. discussion recent technical advances in the processing and evaluation of salivary components have produced reliable results that increase the possibility of using this biological source, which is comparatively safer, cheaper, and less invasive than its traditional alternatives, such as blood and urine. (16) saliva provides an optimum and non-invasive biological source for the quantitative and qualitative assessment of chemical and physiological mediators associated with various conditions, such as stresses, diseases. the major findings of the study were that there was a significant increase in cortisol concentration, which has been developed as a method to assess psychological stress, associated with an increase in the total viable count of salivary bacterial microbiome which is mainly due to drop in the immunity of the body. however, the relation between salivary cortisol level and total viable count of the salivary bacterial variables covid-19 group n=42 covid-19 free group n=42 statistical analysis mean sd mean sd t-test pvalue* cortisol 0.68 0.016 0.62 0.013 18.12 0.007 total viable count of salivary bacterial microbiome x106 78.88 46.54 42.28 41.99 3.78 0.029 variables covid-19 group n=42 covid-19 free group n=42 r-value r-value cortisol x total viable count of salivary bacterial microbiome 0.214 -0.210 j bagh college dentistry vol. 33(4), december 2021 salivary cortisol as 9 microbiome in the covid-19 group could be explained through several possible reasons like; an increase in salivary cortisol may affect the microbial colonization processes such as adhesion and coadhesion. (17) higher cortisol level might suppress the oral immunity and induce the proliferation of the bacteria. (18) during stress, the body’s cortisol level increases the production of ―acid which provides a suitable medium for these bacteria, also an atrophic change of the major salivary glands caused by corticosteroids may lead to a decrease in the quantity (volume) and the composition of the saliva, meanwhile, decreasing the salivary secretion will reduce the clearance of cariogenic bacteria. (19) due the limitations of the current study, thereis the small number of cases in comparison to the cases of covid-19 in iraq, some patients were uncooperative and refused to participate in the study, many patients complained of dry mouth and difficulty in collecting 3 ml of saliva and many samples eliminated from the study due to containing sputum due to cough. conclusion the results of the current study reveal a significant difference in the cortisol values and total viable count of salivary bacterial microbiome between covid-19 and covid-19 free groups. the increase in cortisol values was in covid-19 group, cortisol considers as one of the markers to assess the stress, also the evaluation of the total viable count of salivary bacterial microbiome revealed a rise in its value in covid-19 patients, this may be due to a decrease in patient’s immunity, or due to neglecting for the oral hygiene standards due to the sickness. also there is a positive correlation between cortisol and the total viable count of the salivary bacterial microbiome in the covid-19 group, so when salivary cortisol level increased, there is an increase in the total viable count of the salivary bacterial microbiome in the same group, in comparison with the covid-19 free group which has a negative correlation between cortisol and total viable count of salivary bacterial microbiome. conflicts of interest: none to declare. ethical clearance: all experimental protocols were approved under the department of basic science, college of dentistry, university of baghdad, and all experiments were carried out in accordance with approved guidelines. references 1. palmer-bouva, c., oosting, j., devries, r. et al. stress in elective dental treatment: epinephrine, norepinephrine, the vas, and cdas in four different procedures. gen dent. 1998; 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71(9):1644–52. 19. jain, m., singh, a., ankur s. relationship of perceived stress and dental caries among pre university students in bangalore city. j. clin. diagnostic res. 2014; 10,7860/11664. الخالصة تأثير هل كان مما ، الفيروس انتشار لمنع التجول وحظر الصحي بالحجر نُصحوا حيث ، الناس حياة من كثيرة أجزاء على هائل تأثير٩١كوفيد فيروس لتفشي كان: خلفيةال اإلجهاد يؤثر قد ، لذلك نتيجة. الجسم توازن على سلبًا يؤثر مما ، اإلجهاد إلى والخارجية الداخلية العوامل من العديد تؤدي. والتوتر والقلق للناس العقلية الصحة على كبير الهرمونات تاجوإن البشري العقلي اإلجهاد بين جوهرية روابط الحديثة التحقيقات من العديد وجدت لقد. األمراض مسببات ضد للدفاع الطاقة استخدام على الجسم قدرة على حيوي ركمؤش اللعابي الكورتيزول قياس هو الدراسة هذه من الهدف. اللعابي الكورتيزول ومستويات اإلجهاد بين الصلة األبحاث هذه بعض أثبتت. المناعية المواد أو/ و .٩١كوفيد مرضى بين اللعابية البكتيرية للنباتات اإلجمالي العدد إلى باإلضافة للضغط تتكون والتي٩١كوفيد من الخالية والمجموعة مريًضا٨٤ من٩١كوفيد مجموعة تتكون: مجموعتين إلى تقسيمهم تم الذين البالغين من عينة ٤٨ جمع تم: والطرق المواد للبكتيريا لكليا العدد لقياس المخبرية الفحوصات إجراء تم. المحفز غير اللعاب جمع تم. الصحية حالتهم لتأكيد ار سي بي الختبار األشخاص جميع يخضع. شخًصا ٨٤ من . الكورتيزول مجموعة باستخدام اللعابي الكورتيزول مستوى قياس وكذلك مناسب وسط على الزراعة طريق عن اللعابية كبير بشكل أكبر يةاللعاب للبكتيريا القابل الكلي والعدد اللعابي الكورتيزول كان ، اإلحصائي للتحليل وفقًا. اإلحصائي للتحليل برنامج من ٤٩ اإلصدار استخدام تم: النتائج .٩١كوفيد من الخالية بالمجموعة مقارنة ٩١كوفيد مجموعة في في اللعابي الكورتيزول زتركي يرتفع عندما ، لذلك. اللعابية البكتيرية للنباتات الحي الكلي والعدد اللعابي الكورتيزول بين إيجابي ارتباط على العثور تم: االستنتاجات .اللعابية للبكتيريا اإلجمالي العدد مستوى أيًضا يرتفع ،٩١كوفيد مجموعة articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. saif final.doc j bagh college dentistry vol. 26(2), june 2014 evaluation of the restorative dentistry 37 evaluation of the push-out bond strength of root canal obturation materials filled by four different obturation techniques saif n, b.d.s., m.sc. (1) nawal a. al sabawi, b.d.s., m.sc. (2) maha m. yahya, b.d.s., m.sc. (3) abstract background: the aim of this study was to comparatively evaluate the push out bond strength (pbs) of root canal fillings using four different obturation techniques (single cone (sc), cold lateral compaction (clc), continuous wave (cw), and carrier based gutta percha (cbg)). materials and methods: forty mandibular premolar decoronated and instrumented with rotary protaper to f3 then teeth were divided randomly into 4 groups of 10 teeth for each as follow: group (i) singlecone obturation with matched-taper gutta-percha, group (ii) cold lateral compaction technique, group (iii) continuous wave of obturation technique, and group( iv) carrier based gutta-percha technique. zinc oxide eugenol (zoe) sealer was used as a root canal sealer for the four groups. after obturation of the root canals, all the roots were sectioned horizontally at three levels in the apical, middle, and cervical thirds of each group. pbs test was performed using digital universal testing machine. mode of failures was evaluated using digital stereomicroscope (40 x). collected data were analyzed statistically using one way anova and tukey test. results: pbs of cw and cbg significantly higher than sc and clc, but significantly there were no differences between cw and cbg, and between sc and clc. conclusion: under the condition of this study it can be concluded that thermoplasticized techniques obtain superior pbs of the filling materials in comparisons with cold gutta percha obturation techniques. key words: obturation techniques push-out, protaper, root canal. (j bagh coll dentistry 2014; 26(2): 37-43). introduction root canal treatment is achieved by chemomechanical debridement of the root canal system followed by obturation. nearly 60% of all endodontic failures have been attributed to incomplete obturation of the root canal system. the obturating material acts as a barrier which prevents the ingress of oral fluids and microorganisms resulting in reinfection of the root canal system through micro leakage (1). successful obturation requires the use of materials and techniques that are capable of densely filling the root canal space threedimensionally to provide a fluid tight seal to prevent microorganisms from re-entering the root canal system and to entomb any microorganisms that may remain within the tooth from nutrients in the tissue fluids (2). different obturation techniques have been introduced ranging from solid core filling of gutta-perch to softening techniques with either solvents or heat aiming to achieve a three dimensional obliteration of the root canal system (3). gutta-percha has been the material of choice since the middle 1800s, and it remains the most popular material for obturation due to its biologic, chemical, and physical properties (4). (1)assist. lecturer. department of conservative dentistry. college of dentistry. university of mosul. (2)assist. professor. department of conservative dentistry. college of dentistry. university of mosul. (3)lecturer. department of conservative dentistry. college of dentistry. university of mosul. it is the material of choice to be used with many obturation techniques, including single cone, lateral condensation, warm lateral condensation, warm vertical condensation, and continuous wave techniques (5). recently a technique, which uses a central carrier, pre-coated with thermoplasticised gutta-percha, seems to achieve an obturation that is as well adapted to the root canal system (6). to evaluate the adherence force (adhesion) of the filling to the root canal walls, the strength of the material-dentine interfacial bond should be measured. the push-out bond strength seems to provide the most similar conditions as those observed in clinical conditions, as it measures the material-dentine interfacial bond strength along the entire length of the root canal it also provides repetitive results, allows for testing of materials with low bond strength with dentine and the samples for testing are easy to align. it is also less sensitive to differences in sample sizes and differentiated stress distribution during load application (7-9). the aim of this current study was to comparatively evaluate pbs of root canal fillings using four different obturation techniques (single cone (sc), cold lateral compaction (clc), continuous wave (cw), and carrier based gutta perch (cbg)) at materials-dentin interface. j bagh college dentistry vol. 26(2), june 2014 evaluation of the restorative dentistry 38 materials and methods sample preparation forty human mandibular premolars extracted for orthodontic purpose were collected and stored in distilled water at 37oc. the crowns of the teeth were cut at the level of the cemento-enamel junction to standardize root segments of 15 mm length, by using a diamond sectioning disc that was mounted to a straight handpiece with copious water irrigation. then k-file size 10 was introduced into the root canal to the full working length until it could be seen at the apical foramen under digital stereomicroscope at (x 20) magnification (motic, taiwan). then 1 mm was subtracted from this length to determine the working length. then the teeth were planted in a blocks of silicone impression material of 2 cm length, 2 cm width and 2.5 cm height in order to provide more control and standardization of instrumentation and obturation technique. all root canals were instrumented with protaper (niti) rotary instrument to size f3 using contra-angle rotary handpiece (endo-mate dt, nsk nakanishi, inc., japan). the speed of rotation was maintained at 250 rpm and torques 3 nm. sodium hypochlorite (2% naocl, 2 ml) was used for irrigation between each file size. after completion of canal preparation, the canals were rinsed with 5 ml 15% ethylenediamine tetra-acetic acid (edta). a final rinse of 5 ml distilled water was used to remove any remnant of the irrigating solution. canals were dried using protaper paper points size f3 (9,10). the samples were divided randomly into 4 groups of ten teeth each, as follows: group i: the samples were obturated with single cone obturation technique using matched taper gutta percha for protaper (size f3) (sc). group ii: the samples were obturated with cold lateral compaction technique (clc). group iii: the samples were obturated with the continuous wave of obturation technique by using the diapen diagun cordless obturation system (cw). group iv: the samples were obturated with carrier based gutta-percha technique using the soft-core ® system (cbg). obturaion of the root canals: group i: a size f3 protaper gutta-percha was pre-fitted into the root canal to the full working length and tug-back was tested. zinc oxide eugenol (zoe) sealer was applied with size 30 k-file. the cone was also coated with sealer and introduced into the canal and the excess filling material was removed with a heated spoon excavator (9). group ii: a size 30 iso-standardized guttapercha cone was pre-fitted into the canal to the full working length and tugback was tested. zoe sealer was applied to the root canal walls with size 30 kfile. the master cone was also coated with sealer and inserted to the full working length. then accessory cones (size 25) were used with a light sealer coating and a finger spreader was applied under vertical loading for 10-60 seconds to deform the material apically and laterally. compaction and accessory cones insertion continued until the spreader would reach no further than 23 mm into the canal (11) and finally excess gutta percha was removed with a heated spoon excavator. group iii: a size f3 protaper gutta-percha was pre-fitted into the root canal to the full working length and tug-back action was tested. the gutta-percha cone was then removed and according to the manual instructions of diapen and diagun cordless obturation system, diapen tip was inserted into the root canal to the point (4-7)mm short of the working length, then a rubber stopper was moved and set accordingly. zoe sealer was also used in this group and was applied into the root canal in the same manner as for the first two groups. after that dia-pen devise was powered on and set to the medium temperature mode(200oc).the pen tip was placed in the orifice of the canal, and the middle of the gutta-percha cone was cut and condensed to the point (6-9) mm short of the working length for about (1.5-2) seconds only. then the gutta-percha was again compacted to the point (4-7) mm short of the working length, and then a conventional hand plugger was used for condensation of the remaining gutta-percha and completion of down pack. then the coronal back filling was started at (200o c).the dia-gun's tip was quickly introduced to the canal and thermoplasticised gutta-percha was extruded into the canal and pulled out gently backward until the canal was filled. then a conventional hand j bagh college dentistry vol. 26(2), june 2014 evaluation of the restorative dentistry 39 plugger was used to compact the guttapercha at the orifice of the canal (12). group iv: a size (30) soft-core® size verifier was pre-fitted into the root canal to the full working length. the soft core® dt oven was powered on to start heating of the size 30 soft-core® regular endodontic obturator. zoe was introduced into the canal with size 30 kfile and the heated obturator was placed slowly to the full working length in a single motion. when the guttapercha was cooled, the plastic handle with a metal insertion pin of the obturator was removed by twisting the handle leaving the plastic core and the gutta-percha inside the canal (10). all the samples were sealed coronally with tetric n-ceram composite resin, and then the roots were removed from the blocks and were incubated for 7 days at 37oc in 100% humidity to allow complete setting of the sealer. push-out bond strength (pbs) specimens in all groups were then sectioned perpendicular to their long axis into 3 thirds (coronal, middle, and apical) with 5 mm thickness using a mintom (struers, denmark) with constant water cooling. a 1 mm thick section from the cervical part of each third was prepared. both apical and coronal aspects of each sample were photographed by digital stereomicroscope (x 20) and examined before testing to confirm a circular canal shape and that the sealer filled the entire canal space without voids (figure (1). if the canal was not circular in shape or there was any void in the sealer, it was excluded from the experiment and a replacement tooth prepared in the same way. after that, the samples were aligned over a 2 mm diameter circular hole along the center of an acrylic block (10 mm-thick and 16 mm diameter). the samples were mounted in an apical to coronal direction to avoid any constriction interference due to root canal taper during push out testing. the filling material was loaded with a 1 mm (coronal sections), 0.8 mm (middle section), and 0.5mm (apical section) diameters cylindrical stainless steel plunger which was mounted in the upper part of a digital universal testing machine (terco, mt, 3037, sweden) (figure 2) and should provide almost complete coverage over the main cone without touching the canal wall. the test was conducted at a cross head speed of 0.5 mm/min. the highest value recorded when failure occur was taken as the pbs. the area under load was calculated by ½ × (circumference of coronal aspect + circumference of apical aspect) ×thickness, in which the circumferences and surface area of apical and coronal canal were measured by motic image software connected to digital stereomicroscope. the pbs in mpa was calculated from force (n) divided by area in mm2 (13). mode of failures each sample was viewed at 40x magnification digital stereomicroscope to determine the failure mode and put into one of the following categories: (1) adhesive (at the filling material/dentin interface) (2) cohesive at filling material; and (3) mixed in both adhesive and cohesive modes. figure 1: prepared sample for pbs. (a): coronal aspect. (b): apical aspect. figure 2: digital universal testing machine with the tested sample. j bagh college dentistry vol. 26(2), june 2014 evaluation of the restorative dentistry 40 results one way analysis of variance and tukey post hoc multiple range tests (p≤0.05) were performed to evaluate the differences on pbs among tested groups. one way analysis of variance demonstrated significant differences on the pbs among tested groups as shown in table (1). tukey test revealed that pbs for groups obturated by cw and cbg at different root segments significantly higher than other tested groups, but significantly there were no difference between cw and cbg at different root segments except for apical root segment. result also revealed that pbs of group obturated with sc significantly not different from that oburated by clc at different segments of the root as shown in table (2). the types and the percentage of mode of failures among different tested groups were listed in table (3) and figure (3). table 1: one way analysis of variance for the differences on push-out bond strength at different root segments using different root canal filling techniques. root segments sum of squares df mean squares f p-value* coronal between groups within groups total 11.101 1.046 12.148 3 36 39 3.700 0.029 127.334 0.000 middle between groups within groups total 11.147 1.773 12.920 3 36 39 3.716 0.049 75.444 0.000 apical between groups within groups total 8.037 3.108 11.145 3 36 39 2.679 0.086 31.035 0.000 *df=degree of freedom, *p≤0.05 mean significant different exist. table 2: tukey test for the differences on push-out bond strength among different root canal segments using different root canal filling techniques *the different letters vertically mean significant difference exist. table 3: failure mode among tested root segments using different filling techniques techniques root segments failure mode % adhesive cohesive mixed sc coronal 40 20 40 middle 40 20 40 apical 50 20 30 clc coronal 40 20 40 middle 40 20 40 apical 50 20 30 cw coronal 80 10 10 middle 70 10 20 apical 80 10 10 cbg coronal 80 10 10 middle 80 0 20 apical 90 0 10 root segments techniques mean(mpa)±sd apical middle coronal 1.57±0.32 c 1.63±0.21 b 1.78±0.17 b* sc 1.74±0.22 c 1.820±0.23 b 1.93±0.19 b clc 2.33±0.25 a 2.70±0.22 a 2.83±0.18 a cw 2.69±0.27 b 2.84±0.21 a 2.97±0.19 a cbg j bagh college dentistry vol. 26(2), june 2014 evaluation of the restorative dentistry 41 figure 3: different failure modes. (a) adhesive failure; note clean canal wall. (b) cohesive failure; within tested material. (c) mixed failure; note the material residual inside the canal. discussion ideal adherence of the filling to the root canal dentine is one of the critical factors, for it eliminates leakages in static conditions, which could endanger the tooth by the fluid penetration into the cavity. in dynamic conditions, however, it prevents the material from being translocated by the occlusal load (14). therefore, adherence of the root canal obturation materials filled by different techniques was evaluated in this present study using push out bond strength at materials-dentine interface. no single currently available material is capable of providing perfect root canal filling, which is why most techniques use several materials, the most common being a combination of gutta-percha and cement sealer. for best results, the gutta-percha is generally cold or heat condensed to force the cement sealer into the dentinal tubules (15). thus, this current study was performed to confirm the most suitable technique that had a capacity to forcibly compact the filling materials within root canal space. in this experimental study, pbs of groups obturated with cw and cbg were significantly higher than those oburated by sc and clc in all different root segments. the single-cone technique is considered to be less reliable than other methods due to the unfavorable sealer to gutta-percha ratio, which facilitates the microleakage and quality decrease of interfacial integrity of root canal fillings (16). the single-cone technique comprises the use of a single guttapercha point at environment temperature, with a variable cement thickness depending on the adaptation of the point to the root canal walls (17). this technique has been considered less effective in sealing root canal because of the greater volume of cement that can be expected in the absence of condensation and of the possible anatomic variations of the root canal, which cannot always be filled with larger master cones corresponding to the geometry of the niti rotary instruments (18). in the single point technique the major part of the endodontic space is filled with a cold gutta-percha point, while its irregularities are permeated by the sealer. the amount of sealer in this technique was referred to be greater than in other compaction techniques; so that, porosities in large volumes, contraction, cement dissolution and a lower adaptation of the single cone in the middle and coronal thirds of the canal with irregular shape are the main disadvantages of this technique (19). therefore, the poor adhesion observed with single-cone protaper gutta-percha technique may be related to the fact that the guttapercha is not compressed, but only inserted into the working length with a large amount of cement (20). cold lateral condensation is a proven, classic technique. while one of the most widely used techniques, its effectiveness has often been called into question, with a number of studies reporting that lateral condensation results in nonhomogenous obturation, poor adaptation of guttapercha to canal walls, and gaps between the main and accessory cones, voids, spreader tracks, spaces between the gutta-percha points and sealer pools have been reported by various investigators after obturation by lateral condensation (21). for that reasons it will result in low pbs in the present study. thermoplasticised gutta-percha techniques have been developed in an effort to improve the obturation of root canal irregularities, to improve density of the fill, and to reduce voids. cwt which was a single master cone corresponding to the master apical file was used in conjunction with a heat source and pressure from the heated plugger. this technique provides an effective apical seal in addition to obturating lateral canals. the continuous wave of condensation uses a plugger attached to a heat source. the heated plugger is used to vertically compact the guttapercha in one motion (22,23). one of the most recent techniques, which use central carriers precoated with thermoplasticized gutta-percha, seems to achieve an obturation that is well adapted to the b a c j bagh college dentistry vol. 26(2), june 2014 evaluation of the restorative dentistry 42 root canal system. the advantage of carrier-based systems is the potential for plasticized guttapercha to flow into the canal irregularities (24). because of these before describe reasons thermoplasticized gutta-percha techniques obtained a good pbs than other techniques in the present study. but, the cause of that cw produce higher pbs than cbg in apical third of the root might be related to the fact that friction against the canal walls can lead to loss of gutta-percha from the carrier especially in the apical third of the canals therefore exposing the carrier and creating a gap (25). marciano et al. (26) performed a study aiming to compare the gutta-percha/cement percentage and empty spaces through four different techniques. result showed that more gutta-percha, less cement and empty spaces can be observed in thermoplasticized techniques than in sc and clc. another study revealed that a key of clinical success is complete closure of the dentinal wall obturation interface especially in the apical part to achieve the best apical seal. most endodontic sealers are soluble and shrink slightly; so, it is best to rely as little as possible on sealers and more on gutta percha material (15). therefore, as thermoplasticized techniques result into thin film thickness of the sealer in comparison to that of cold gutta percha obturation techniques so they obtained a highly significance pbs than cold compaction techniques in the current study. several studies also demonstrated that in thermoplasticized techniques, the softening gutta percha had the ability to flow into deep depression, lateral canal, accessory canal, and irregularities that are not filled by sealer cement (15,23,26,27). therefore, thermoplasticized techniques facilitate compaction of the filling material into root canal space more preferably than cold gutta percha obturation techniques; and this reason can be consider as most important factor that result into superior pbs of thermoplasticized technique over cold gutta percha obturation techniques in our present study. the most common mode of failures obtained in this study was adhesive and mixed. although thermoplasticized techniques can produce better compaction of the filling material in the canal space but it remains their adhesion is effected by the type of sealer used in conjunction with the gutta percha, as zoe sealer was used in this study and it's well known that zoe had weak adhesion to the canal wall and gutta perch. so, it will effect in the adhesions properties of the filling materials. within the limitation of this study it can be concluded that the filling techniques and material used will influence the push-out bonding strength of the material-dentin interface. according to the findings of the present study it can be concluded that the force needed for the displacement of root canal filling obturated by thermoplasticized techniques was significantly higher than that required for the displacement of the filling materials obturated by cold gutta percha obturation techniques. references 1. shanahn dj, duncan hf. root canal filling using resilon ®: a review. br dent j 2011; 2: 81-9. 2. carrotte p. endodontics: part 8; filling the root canal system. br dent j 2004; 179: 667-72. 3. stiegemeier d, baumgartner jc, ferracane. comparison of push–out bond strength of resilon with three different sealers. j endod 2010; 36: 318-21. 4. smith rs, weller rn, loushine rj, kimbrough wf. effect of varying the depth of heat application on the adaptability of gutta-percha during warm vertical compaction. j endod 2000; 26: 668-72. 5. clinton k, himel vt. comparison of a warm guttapercha and lateral condensation. j endod 2001; 27: 692-5. 6. abarca am, bustos a, navia m. a comparison of apical sealing and extrusion between thermafil and lateral condensation techniques. j endod 2001; 27: 670-2 7. lee bs, lai eh, liao kh, lee cy, hsieh kh, lin cp. a novel polyurethane-based root canal obturation material and urethane-acrylate-based root canal sealer – part 2: evaluation of push-out bond strengths. j endod 2008; 34: 594-8. 8. ungor m, onay eo, orucoglu h. push-out bond strengths: the epiphany-resilon endodontic obturation system compared with different pairings of epiphany, resilon, ah plus and gutta-percha. int endod j 2006; 39: 643-7. 9. jainaen a, palamara jea, messer hh. push-out bond strengths of dentin-sealer interface with and without a main cone. int endod j 2007; 40: 882-90. 10. boussetta f, bal s, rmeas a, boivin g, magloire h, farge p. in vitro evaluation of apical microleakage following canal filling with coated carrier system compared with lateral and thermo mechanical guttapercha condensation technique. int endod j 2003; 36: 367-71. 11. dadresanfar b, khalilak z, shiekhleslami m, afshar s. comparative study of the sealing ability of the lateral condensation technique and beefill system after canal preparation by the two rotary system. j oral sci 2010; 52: 281-5. 12. leonardo mv, goto wh, torres crg, borges ab, caravalho cat, barcellos dc. assessment of the apical seal of root canals using different filling techniques. j oral sci 2004; 51: 593-9. 13. pawińska m, kierklo a, tokajuk g, sidun j. new endodontic obturation systems and their interfacial bond strength with intraradicular dentine – ex vivo studies. advances med sci 2011; 56: 327-33. 14. tagger m, tagger e, tjan ahl, bakland lk. measurement of adhesion of endodontic sealers to dentin. j endod 2002; 28: 351-4. j bagh college dentistry vol. 26(2), june 2014 evaluation of the restorative dentistry 43 15. guigand m, glez d, sibayan e, cathelineau g, vulcain jm. comparative study of two canal obturation techniques by image analysis and eds microanalysis. br dent j 2005; 198: 707–11. 16. de-deus g, reis c, de abranches am, countinhofilho t, paciornik s. limited ability of three commonly used thermoplasticized gutta-percha technique in filling oval shaped canal. j endod 2006; 34:1401-5. 17. economides n, kokorikos i, kolokouris i, panagiotis b, gogos c. comparative study of apical sealing ability of a new resin-based root canal sealer. j endod 2004; 30: 403-5. 18. monticelli f, sadek ft, schuster gs, volkmann kr, looney sw, ferrari m. efficacy of two contemporary single-cone filling techniques in preventing bacterial leakage. j endod 2007; 33: 310-3. 19. whitworth j. methods of filling root canals: principles and practices. endod topics 2005; 12: 2-24. 20. yücel aç, çiftçi a. effects of different root canal obturation techniques on bacterial penetration. oral surg oral med oral pathol oral radiol endod 2006; 102: e88-e92. 21. ozok a, sluis l, wu m, wesselink p. sealing ability of a new polydimethyl siloxane-based root canal filling material. j endod. 2008; 34: 204-7. 22. cantatore g. root canal obturation and root integrity. endod prac 2006; 4: 30-2. 23. natera m, pileggi r, nair u. a comparison of two gutta-percha obturation techniques to replicate canal irregularities in a split-tooth model. oral surg oral med oral pathol oral radiol endod 2011; 112: e29e34. 24. abarca am, bustos a, navia m. a comparison of apical sealing and extrusion between thermafil and lateral condensation techniques. j endod 2001; 27: 670-2. 25. weller rn, kimbrough wf, anderson rw. a comparison of thermoplastic obturation techniques: adaptation to the canal walls. j endod 1997; 23: 703-6. 26. marciano ma, ordinola-zapata r, cunha tvrn, duarte mah, cavenago c, garcia rb. analysis of four gutta-percha techniques used to fill mesial root canals of mandibular molars. int endod j 2011; 44: 321-9. 27. bowman cj and baumgartner jg. gutta-percha obturation of lateral grooves and depressions. j endod 2002; 28: 220-3. journal of baghdad college of dentistry, vol. 35, no.1 (2023), issn (p): 1817-1869, issn (e): 2311-5270 76 review article complete blood count and saliva parameters as an indicator for infected patients with coronavirus covid-19 sumaiah i. hussein 1, suha t. abd 1*, fadia a. al-khayat 1, heba k. mahmood1 1 department of basic sciences, college of dentistry, university of baghdad, baghdad-iraq * correspondence email, suhatalal_abd@codental.uobaghdad.edu.iq abstract: background: coronavirus, which causes respiratory illness, has been a public health issue in recent decades. because the clinical symptoms of infection are not always specific, it is difficult to expose all suspects to qualitative testing in order to confirm or rule out infection as a test. methods: according to the scientific studies and investigations, seventy-three results of scientific articles and research were obtained using pubmed, medline, research gate and google scholar. the research keywords used were covid-19, coronavirus, blood parameters, and saliva. results: this review provides a report on the changes in the blood and saliva tests of those who are infected with the covid-19.covid-19 is a systemic infection that has a substantial influence on the hematological system and hemostasis, thus deviations from normal levels of laboratory tests, including the blood and saliva test show that specific testing for detecting covid-19 infection is required. conclusions: the blood and saliva tests aid in the clinical monitoring of the patient's health. it has advantages such as the following: it has noninvasive properties, low cost, and good stability, addition to minimum risk of infection transport. key words: coronavirus. blood parameters, saliva, covid-19. introduction an sars-cov-2-related pneumonia outbreak that started in wuhan in december 2019 has quickly spread across china and even the rest of the globe. on february 11, 2020, the who officially designated this sarscov-2 disease as coronavirus disease (covid-19) (1). who reports that as of 20 june 2022, there have been 539,893,858 verified cases, with 6,324,112 deaths. (2). patients with covid-19 infections may experience moderate or serious acute respiratory infections, with milder instances exhibiting symptoms like temperature, dry cough, and fatigue. additionally, some patients may also have aberrant lung ct results along with stomach symptoms like diarrhea, nausea, and vomiting, in addition to ocular or cutaneous symptoms, in addition to olfactory and gustatory dysfunctions (3). acute respiratory distress syndrome (ards), acute hypoxemic respiratory failure, sepsis and septic shock, thromboembolism, and/or multi-organ failure, including acute kidney injury and cardiac injury, are among the complications that can occur in people with covid-19. the majority of patients with covid-19, roughly 40% of patients, only experience mild or moderate disease (4,5). reverse transcription-polymerase chain reaction (rt-pcr) is used to make the diagnosis, along with medical imaging such as x-ray and computed tomography (ct) features of asymptomatic infections (6,7,8,9,10), because the viral load of sars-cov-2 rna in the upper respiratory tract was significantly higher during the first week(11,12), as well as nasopharyngeal and oropharyngeal swabs (13,14,15). the illness has become a significant global health problem and has reached pandemic status, infecting people in nearly every country on the planet, the treatment must be taken, and hence, the doctors demand additional diagnostic procedures, such a complete blood count (cbc) and saliva parameters, during this time. received date: 02-12-2022 accepted date: 27-02-2023 published date: 15-03-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/l icenses/by/4.0/). https://doi.org/10.2647 7/jbcd.v35i1.3317 mailto:suhatalal_abd@codental.uobaghdad.edu.iq https://orcid.org/0000-0002-7241-4670 https://orcid.org/0000-0003-4890-5469 https://orcid.org/0000-0001-7221-3898 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i1.3317 https://doi.org/10.26477/jbcd.v35i1.3317 j. bagh. coll. dent. vol. 35, no. 1. 2023 hussein et al 77 complete blood count (cbc): a complete blood count is a blood test that examines a number of factors, including hemoglobin, white blood cells, platelets, lymphocytes, and red blood cells. (hgb). hematocrit (hct or pcv), mean corpuscular volume (mcv), mean corpuscular hemoglobin concentration (mchc), lymphocyte count, and other variables. a cbc test is used to help with the working diagnosis of a number of illnesses, such as anemia, acute infections, hemorrhagic states, allergic disorders, cancers, and immune disorders, as well as to assist medical professionals in assessing any symptoms, such as weakness and fatigue; for instance, a low hematocrit was once believed to be a sign of breast cancer patients, as well as leucopoenia and thrombocytopenia (16). several systemic inflammatory biomarkers have recently become accessible as part of the extended cbc, these cbc-based biomarkers are being studied in a variety of fields because they are simple and inexpensive, making them accessible to a wide range of physicians, as well as they require just a little quantity of patient blood. hence, the hematological laboratory, according to covid-19 research, plays a key role in providing numerous helpful prognostic indicators (17). as a result, the goal of this review is to highlight certain covid19 hematologic results and give recommendations for early prevention and treatment. white blood cells or leukocytes (wbcs) according to the scientific evidence, white blood cells (including granulocytes that refer to neutrophils, eosinophils, and basophils and granulocytes that refer to lymphocytes and monocytes) protect the body against infection, particularly lymphocytes which increase in number in situations of inflammation, especially when a virus is present. the majority of viral illnesses, including those caused by the hepatitis c virus (hcv), hepatitis b virus (hbv), and human immunodeficiency virus (hiv) disease, are characterized by elevated white blood cell (wbc) numbers, especially lymphocyte counts (18,19) lymphocytes generally, most viruses lead to relative lymphocytosis (20) .lymphocytosis mean an increase in the count of lymphocyte to more than 4000 lymphocytes/µl in adult patients,(21)while only a few viruses such as severe acute respiratory syndrome coronavirus-2 (sars-cov-2) cause a decrease in lymphocytes in infected patients that called lymphopenia. (18, 22,23,24). lymphopenia can be brought on by a number of factors, including the virus' direct impact on lymphocytes, which can result in lysis of those cells, or the virus' induction of inflammatory cytokines, which can prevent t cells from expanding, and which, as a result, can cause immune-mediated apoptosis of lymphocytes, which is thought to be a good predictor of severity and mortality in covid-19 infections (25,26,27,28) monocytes the normal count of monocytes about 200-800 cells per µl of blood in a healthy human is (2-8% of wbcs count). monocytes play important role in the innate immune system against microbial pathogens, inflammatory and antiinflammatory, as well as assisting in the pathophysiology and development of illnesses such tumor metastasis, liver fibrosis, atherosclerosis, and multiple sclerosis. in alzheimer's disease, liver fibrosis regresses, muscles regenerate, and -amyloid plaques are cleared by monocytes and monocytederived macrophages. (29,30). patients with moderate covid-19 who have circulating monocytes in their blood who have an inflammatory viral infection cause these circulating monocytes to migrate to the lung under the guidance of pro-inflammatory cytokines, which increases the amount of defending mononuclear phagocytes and intensifies inflammation(31)biamonte et al (32) found that lymphocyte/monocyte counts at admission and during the hospital stay, can predict clinical progression in covid-19; another study suggested that mean j. bagh. coll. dent. vol. 35, no. 1. 2023 hussein et al 78 neutrophil/lymphocyte ratio (nlr) and neutrophil/monocytes ratio (nmr) was higher in patients with covid-19 particularly in diabetic patients(33) eosinophils the normal count of eosinophils is less than 500 cells per µl, they are involved in the fight against multicellular parasites, proinflammatory effects in a variety of diseases, allergy, and asthma regulation mechanisms. in covid-19, some studies discovered a decrease in eosinophil’s, which might suggest that the patient is in the early stages of illness or that the result is positive (23) or that eosinopenia (decrease in the number of eosinophil’s) is linked to rapid respiratory impairment following a severe covid-19 infection (33,34). as a result, eosinopenia in combination with lymphopenia may be a useful indication for individuals with covid-19 (35). basophils the normal count of basophils is about 0-300 cells per µl of blood and less than 3% of wbcs, it contains heparin, hence it prevents blood clotting, mediates allergic reactions, and acts as anti-parasitic protective immunity. basophils seem to have an active role in the immune response to sars-cov-2 (36). several investigations noted that basophils were found in lower count in covid-19 patients (37, 38,39), while the others reported that basophils were also found in lower count in the first days of infection but they return to the normal value or increase during recovery (40,41). neutrophil the majority of circulating leukocytes are neutrophils, which take part in a variety of immunological and inflammatory processes through phagocytosis, particle formation, cytokine release, and other mechanisms. patients with covid-19 may have a bad prognosis because of elevated nytrophil/lymphocyte ratio (nlr) values and low lymphocyte/c reactive protein ratio (lcr) levels that imply an intensified inflammatory process(42) additionally, the assessed neutrophil or neutrophil-to-lymphocyte ratio (nlr) is thought to be the primary marker of cytokine storms, especially in individuals who are older and have a chronic illness (43,44) .however, the nlr may be related to the severity of the disease, and frequent use of these parameters may help in the assessment of the condition (45). in the special study of lu and wang (46) for dynamic change in wbc of patients during hospitalization, they noted that the value of wbcs in continuous changing, on the second day of admission, the number of neutrophils, lymphocytes, monocytes, and eosinophils decreased; however, from the eighth to the fourteenth day of admission, the number of wbcs, neutrophils, monocytes, and eosinophils gradually rose and peaked on the fourteenth day of covid-19 infection. the ratio may help differentiate patients with severe diseases from those with less severe diseases, in addition to the change in lymphocytes and nlr (47). red blood cells (rbcs) and hemoglobin a normal rbc counts in men about 4.7 to 6.1 million cells/µl and in women about 4.2 to 5.4 million cells/µl. because the rbcs were generated from hematopoietic stem cells in the bone marrow, there was a decrease in variations in rbcs that can be linked to the hematopoietic system. additionally, the high doses of drugs, longterm treatment, and the route of administration have an impact on this system. the study of nader et al (48) showed that patients with covid-19 had higher blood viscosity despite having reduced hematocrits (hct; hct is the ratio of rbc volume to total blood volume), as well as higher rbc aggregation, than healthy individuals. this indicates a positive correlation between clot firmness and duration of hospitalization and a negative correlation with clot formation time, particularly in patients receiving oxygen supplementation and those with pulmonary lesions that increased coagulation. while urbano et al.'s (44) j. bagh. coll. dent. vol. 35, no. 1. 2023 hussein et al 79 research revealed that erythrocytes and cell hemoglobin concentration mean (chcm) are both decreased and separately linked to covid-19 patients' mortality. data results of anani et al (49) revealed lower hemoglobin (hb) and hematocrit (hct) in covid-19 survivors, but higher red cell distribution width. (rdw). red blood cells typically have a biconcave shape, are nucleated, and lack organelles; however, in individuals with covid-19, rbcs take on an abnormal mushroom shape. this alteration in erythrocyte morphophysiology may be connected to the unbalanced redox status observed during covid-19, which affects the genetics and dynamics of erythrocytes and results in multiple organ failure syndrome and death by non-homeostatic function of the cardiovascular, respiratory, and renal systems.(50,51)contrary to what was previously known, the study claimed that erythrocytes and cell hemoglobin concentration mean (chcm) are independently related to mortality in sars-cov-2 positive patients (44). because covid-19 may be to blame for the reduced rbc circulation that maintains hypoxemia and prevents tissue oxygenation, which is already difficult in patients with acute covid-19 respiratory syndrome, as well as a decrease in hb level that results in anemia, changes in iron metabolism are related to hypoxemia in covid-19 patients (52,53,54). platelets platelets are responsible about blood clotting or called thrombus, normal account of platelets about 150.000450.000/µl, and platelets less than is called thrompocytopenia. thrombocytopenia linked with chronic hepatitis c virus (hcv) the virus attacks platelet surface antigens, causing a drop in platelet count, which can be brought on by a number of processes, including an autoimmune reaction, viral-induced bone marrow suppression, and autoantibodies aimed at the virus. both covid-19 and this virus, which is transmitted similarly, have the ability to cause thrombocytopenia. (55). in covid-19 patients, mild thrombocytopenia or a low platelet count are linked to a higher chance of serious illness and mortality, or, less frequently, thrombocytosis in others (56). in north india and with the second wave of covid-19, some studies showed thrombocytopenia is most common in patients, especially those who will need intensive care unit because the virus is thought to inhibit bone marrow hematopoiesis through certain receptors resulting in thrombocytopenia with lymphopenia (57,58). finally, medications and viral complications can interact with blood components and trigger an inflammatory response, resulting in increased or decreased immune system activity and altered hematologic factors such as blood cell count. other factors, such as the early and late stages of the disease, the length of therapy, and the intensity of symptoms, all have a part in limiting the number of blood cells. because cbc is impacted by various parameters such as age, gender, and patient immunity, some discrepancies in hematological findings were seen. as a result, these hematological indicators can be beneficial to the covid-19. saliva salivary glands secrete an extracellular fluid in the mouth known as saliva that has many function. reports have revealed that saliva can harbor covid-19 and can be used to monitor viral loads and diagnose infection. (59, 60) where it has been proven that saliva samples are inexpensive, easy to collect, and do not require equipment to collect them, they are stable for a long time and reduce the risks of interactions between people and health care workers, as well as, it can reduce the need for equipment personal prophylaxis (61,62). j. bagh. coll. dent. vol. 35, no. 1. 2023 hussein et al 80 among 31 covid-19 patients, chen et al show that 46.3% who suffer from dry mouth and 47.2% have amblygeusia, hence the study of this group decided that these symptoms can be considered as initial symptoms of covid-19 infection (63). liu et al (64) they found that patients with severe covid-19 tend to have a high viral load and a lengthy virusshedding period, suggesting that disease severity and immune status are positively correlated with viral load. in a different research by silva et al. (65), the viral loads in the nasopharynx and saliva were examined, and it was found that cases with covid-19 risk markers had significantly higher viral loads in the saliva (e.g. male gender, older age, specific respiratory, cardiovascular, oncologic, and other systemic and immune-suppressive conditions ). data of huang et al (66) showed that the oral cavity is a significant site for sars-cov-2 infection, implicating saliva as a possible means of transmission. the viral load in saliva was correlated with covid-19 symptoms, including taste changes or loss. according to information from another study, saliva, including its cellular components and mechanisms, contains viral particles and aids in covid-19 transmission (67). even though sars-cov-2 may enter through the mouth, additional elements, such as salivary protease inhibitors that prevent viral entrance, should be taken into account(68). in a study by sasikala et al. (69), 3018 outpatients (with symptoms and without symptoms) were used to compare saliva samples and nasopharyngeal swabs to identify the virus. the researchers informed the patients as soon as the symptoms began that the maximum detection in saliva was discovered on day 3 after the beginning of symptoms. researchers came to the conclusion that saliva, which is easier to gather than nasopharyngeal swabs, is a reliable alternative to identify sars-cov-2 in symptomatic patients at the early stage of onset of symptoms. furthermore, 12.8% of hospitalized patients only tested positive for saliva. however, despite having a lower sensitivity in asyptomatic patients, saliva is still a crucial tool for massscreening for covid-19, according to some study. additionally, saliva demonstrated high sensitivity for the detection of sars-cov-2 in symptomatic patients, making it a suitable specimen for the initial diagnosis of covid-19 in that patient group, especially in the absence of swabs. additionally, saliva is essential for the covid-19 screening of asymptomatic individuals (70). however, according to various studies' recommendations for sampling techniques, the concentration of rna can be increased by fasting for up to overnight before collecting saliva. additionally, rinsing the subject's mouth with water rather than antiseptic mouthwash is advised (71,72). last but not least, there are several advantages to using saliva samples as specimens for the diagnosis of sars-cov-2, including the collection being non-invasive in contrast to the collection of nasopharyngeal swabs, which is typically thought to be uncomfortable and when nasopharyngeal swabs are collected by healthcare professionals, protective gear is required, whereas the saliva samples collection can be easily performed by the individual themselves if they are properly prepared because it is non-invasive. saliva collection is therefore a desirable substitute for nasopharyngeal swabs (73). conclusion a complete blood count is reliable and low-cost. the quick reading test aids in the screening of patients suspected of having covid -19 infections, and it is one of the first filters that may be used in decision-making. depending on the clinical characteristic and the results of additional lab tests, saliva plays an important role in diagnosing infection, but it is linked to the viral load, as it has sensitivity equal to or higher than nasopharyngeal swab in people who show symptoms of the disease. however, the hematological and saliva criteria are still used to predict hospitalization, serious illness, and prognosis and may aid medical professionals in making the right therapeutic decisions, as well as understand the physiological mechanism of viral infection and human immunity. j. bagh. coll. dent. vol. 35, no. 1. 2023 hussein et al 81 references 1. yanxiang, z ., xuejie, h., meijiao, h., et al. hydroxychloroquine use and progression or prognosis of covid-19: a systematic review and meta-analysis. naunyn schmiedebergs. arch pharmacol. 2021; 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14: e23495. j. bagh. coll. dent. vol. 35, no. 1. 2023 hussein et al 84 59. 59.valentine-graves, m., hall, e., guest, j.l., et al. at-home self-collection of saliva, oropharyngeal swabs and dried blood spots for sars-cov-2 diagnosis and serology: post-collection acceptability of specimen collection process and patient confidence in specimens. plos one. 2020; 15: e0236775. 60. to k.k., tsang, o.t., yip, c.c., et al. consistent detection of 2019 novel coronavirus in saliva. clin infect dis. 2020; 71: 841–843. 61. 61.berenger, b.m., conly, j.m., fonseca, k., et al. saliva collected in universal transport media is an effective, simple and high-volume amenable method to detect sars-cov-2. clin microbiol infect. 2020; 27: 656–657. 62. matic, n., stefanovic, a., leung, v., et al. practical challenges to the clinical implementation of saliva for sars-cov2 detection. eur j clin microbiol infect dis. 2020; 40: 1–4 63. 63.chen, l., zhao, j., peng, j., et al. detection of sars-cov-2 in saliva and characterization of oral symptoms in covid-19 patients. cell prolif. 2020; 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101(3): 115450. 71. goode, mr., cheong, sy., li, n., et al. collection and extraction of saliva dna for next generation sequencing. j vis exp. 2014; 4: 253. 72. ishikawa, s., sugimoto, m., kitabatake, k., et al. identification of salivary metabolomic biomarkers for oral cancer screening. sci rep. 2016; 6: 31520. 73. erupean center disease prevention and control (ecdc),technical report. considration for the use of saliva as sample material for covid-19 testing. 2021,stockholm. ةعلى اصابة المرضى بفايرس المتالزمة التنفسيؤشرمعايير اللعاب وتعداد الدم الكامل كع لعنوان: ا 0192 ,هبة خزعل محمود ,فادية عبد المحسن ,سهى طالل عبد سمية ابراهيم حسين : الباحثون . مستخلص لا ألن األعراض السريرية للعدوى ليست دائًما وفيروسات كورونا :تعتبرالخلفية التي تسبب أمراض الجهاز التنفسي مشكلة صحية عامة في العقود األخيرة. نظًرا محددة ، فمن الصعب تعريض جميع المشتبه بهم لالختبار النوعي من أجل تأكيد أو استبعاد العدوى كاختبار. researchوبوابة الباحث medlineو pub medالنتائج البحثية حصلت عن طريق المقاالت وثالث وسبعون من اسات والتحقيقات العلمية ، وفقًا للدر الطرق: gate وgoogle scholar. .covvid-19و الكلمات المفتاحية المستخدمة للبحث هي : كورونا فايرس ،معايير الدم واللعاب https://doi.org/10.1101%2f2021.01.04.21249236 j. bagh. coll. dent. vol. 35, no. 1. 2023 hussein et al 85 هو عدوى جهازية لها تأثير كبير على نظام الدم واإلرقاء covid-19 . التغيرات في اختبارات الدم واللعاب للمصابين بفايرس وفرت المقالة تقرير عن النتائج: تشير إلى أن االختبارات المحددة للكشف عن عدوى واللعاب، وبالتالي فإن االنحرافات عن المستويات الطبيعية لالختبارات المعملية ، بما في ذلك اختبار الدم covid-19 .مطلوبة ال االستنتاجات: في الدم اختبارات بتساعد يتمتع حيث ، المريض. لصحة السريرية ، التالية مزايا المراقبة المنخفضة والتكلفة ، الغازية غير خصائصه مثل: واالستقرار الجيد ، باإلضافة إلى الحد األدنى من مخاطر انتقال العدوى. .19-، بارامترات الدم ، اللعاب ، كوفيد الكلمات المفتاحية: فيروس كورونا 19 j bagh college dentistry vol. 33(1), march 2021 comparison between the comparison between the mesiodistal crown dimensions of second primary molar with stainless steel crowns from different companies dunia a. al-dulaimy (1), mohammed r. al-khannaq (2) https://doi.org/10.26477/jbcd.v33i1.2923 abstract background: due to the variations in tooth anatomy and size among different populations, this study aimed to compare the mesiodistal width of primary second molars in iraqi children with the mesiodistal width of stainless-steel crowns from different companies. materials and methods: this cross-sectional study was conducted on 220 intact maxillary and mandibular primary second molars selected from boys and girls’ iraqi children aged 8-9 years collected from different primary schools in baghdad city. the mesiodistal dimensions of the selected teeth and the available maxillary and mandibular stainless-steel crowns from three different companies were measured by using a 3-d scanner, and then the whole measurements were calculated using 3 shape ortho-analyzer software program. results: data were analyzed statistically via spss v 26 software and the results showed that there’s non-significant difference between the md measurements of second primary molars between right and left sides, and high significant difference were recorded with higher mean values for boys than girls. when comparing the same mesiodistal measurement between molars with that of stainless-steel crowns, only limited sizes of stainless steel crowns were found to be fitted to the molars of iraqi children. conclusion: more studies need to be applied using other stainless steel crown companies to find the relation in the mesiodistal measurement of iraqi populations. key words: mesiodistal width , second primary molars, stainless steel crown. (received: 31/1/2021, accepted: 1/3/2021) introduction clinicians should provide the best preventive or restorative dental treatment for pediatric patients to shape their teeth in the future. there must be an understanding of the pediatric patient's caries risk, the developmental stage of the dentition, and the dental pulp's status to determine the choice of restorative material and technique. the objective of any restorative procedure is to: restore the tooth damage from dental caries, protect and preserve the remaining pulp and tooth structure, retain adequate function and aesthetics and finally to maintain the arch length and space for the developing permanent successors. many restorative materials and techniques for carious teeth were introduced to restore the primary teeth (1). clinicians should determine the extent of tooth destruction and the ability to re-establish a functional crown morphology with adjacent contacts (2). (1) master degree in pedodontics, assistant professor in dentistry college \ al-mustansiryah university (2) master degree in orthodontics, assistant professor in dentistry college \ al-mustansiryah university. corresponding email, drduniaahmed13@yahoo.com when dental caries affects more than one surface of the tooth, the restorative procedure becomes more difficult. dental caries removal can necessitate more thorough cavity preparation. the larger the reconstruction, the more likely it is to fracture (3). primary teeth have a higher rate of restorative material loss than permanent teeth (4). patient cooperation, primary tooth morphology, variations in tooth anatomy, and the form of restorative material used all contribute to this (5,6). stainless steel crowns, which have gained popularity among pediatric dentists due to their good performance as a restorative material, are one of the techniques for preserving carious primary molars (7,8) and because the complete coronal coverage of primary teeth enhances the tooth's structural integrity and the restoration's longevity (1). in primary molars, stainless steel crowns are recommended, particularly when caries affect multiple surfaces (9). the stainless steel crown, which consists of a nickel-chrome alloy, was first introduced by humphrey in 1950 (10). nowadays, stainless steel crowns are used excessively to restore grossly decayed primary or early permanent teeth in pediatric dentistry. however, the introduction of minimal intervention sealed restorations (known as the 'hall crown https://doi.org/10.26477/jbcd.v33i1.2923 mailto:drduniaahmed13@yahoo.com 20 j bagh college dentistry vol. 33(1), march 2021 comparison between the technique') has made the use of these restorations more realistic (11). commonly there are two major types of stainless steel crowns used either; pre-trimmed type, which has non-contoured sides but is festooned to follow a line parallel to the gingival crest; or the precontoured type, which reproduces a cervical contour similar to that of natural teeth and is also festooned (10,12). pre-contoured stainless steel crowns are widely used because they are easy to manipulate and adapt, e.g., the 3m espe stainless steel primary molar crown nd-96 (3m espe, st. paul, mn, usa) and the kids crown (shin hung, seoul, korea). morphological characteristics of primary teeth are precious tools for pediatric dentists, orthodontists, and anthropologists. regarding the morphology of the maxillary primary second molars, it is rhomboidal in shape and resembles the permanent maxillary first molar in appearance; however, it is slightly smaller and at the same time larger than the first primary molar. in contrast to its mesiodistal measurement at the contact points, the crown is small at the cervix. although the mandibular second molar looks and acts similarly to the mandibular first permanent molar, the primary tooth appear smaller in all dimensions when viewed from the occlusal surface (13). therefore, an understanding of the morphologic characteristics of a ssc and the natural teeth of the patient is required to shorten the chair time and fit the margin of the stainless steel crowns. studies on the morphology and size of the primary teeth or stainless steel crowns have not been actively pursued so far, and the existing studies on the morphology of teeth were primarily performed by measurements using a caliper (14,15). alternative methods of measurement to the use of a caliper have been suggested. nowadays, using the three dimensional (3d) computed tomography. gradually, the use of 3d scanners is increasing and is now beginning to be used in the morphologic study of teeth (16). in this technique and after scanning the object from every angle, measure the distance, angle, and volume accurately by reconstructing the 3d image. in comparison with computed tomography scan (ct scan), 3d scanners do not require exposure to harmful radiation. although 3d scanners have the disadvantage of the requirement for expensive equipment and software, once the operator becomes accustomed to the process of using the 3d scanner, we can expect to shorten the time and achieve much more accurate results upon implementing stainless steel crowns. in the present study, the main target was to measure the mesiodistal width of the primary second molar teeth in iraqi children aged 8-9 years from baghdad city and to compare the values for these dimensions to the values for the corresponding dimensions of stainless steel crowns manufacturer by three different companies of pre-contoured stainless steel crowns for the second primary molar using a 3d scanner. the three types of sscs include (3m ssc, kids crown, rihani crowns) then using 3 shape analyzer software program to perform the measurement. material and methods the sample: this cross-sectional study was conducted on 55 children, 27 were boys, and 28 were girls aged 8-9 years at the mixed dentition stage from different primary schools in baghdad\ iraq, the total teeth selected for the measurement were 220 maxillary and mandibular second primary molars. a signed consent form was collected from parents for approval to participate their children in the study and to informed about any medical problems of their children (appendix). the selected children for the present study were with the following criteria: 1healthy children without any systemic disease, depending on the children's medical history given by their parents. 2the dentition without any caries, restorations, hypoplasia, or other dental anomalies. 3erupted and caries-free primary second molars. maxillary and mandibular alginate impressions were taken for the dentition for the selected children. the mesiodistal crown measurements of the second primary molars (e) were performed on dental models. the research did not include lowquality casts (14,17,18). methods: the mesiodistal width of each second primary molar was measured on a dental study cast for each child at the widest distance between the contact points (14,19,20). for the accuracy of the mesiodistal width of each stainless steel crown, first mounting one of each size of stainless steel crown from the kit on silicon impression material (c-silicon protesil, vannini cental industry italy), labeled according to each company and quadrant, then waiting for 21 j bagh college dentistry vol. 33(1), march 2021 comparison between the complete material setting according to the manufacturer instruction to be ready for scanning. (figure 1). figure 1: mounting and labeling one of each size of stainless steel crown on silicon impression material. scanning of the selected study models and stainless-steel crown models to perform the measurement were applied using (d2000,3 shape, denmark). to improve the 3d scanning measurement, a pre-treatment involving a specialized spray (scan spray nht high technology, latvia) to coat the metal surface was applied (figure 2). the thickness of the coating was 15 µm. as suggested by the manufacturer, and thus, we subtracted this thickness from the measurement results of this study. after the scanning process, the image was analyzed using 3 shape ortho analyzer programs to perform the measurements for the maxillary and mandibular study casts (figure 3) and for the maxillary and mandibular set of stainless steel crowns (figure 4). figure 2: specialized spray to coat the metal surface . figure 4: the maxillary and mandibular ssc set each stainless steel crowns kit provide six sizes 2,3,4,5,6,7 and there are certain number of the crowns for each size, and since the dimensions of the same-size crowns manufactured by the same company are equal, two of the stainless steel crowns of each number were evaluated to increase the accuracy of the reading. md measurements were applied on the second primary molars on the casts, then the same md measurements were applied on the stainless steel crowns from three different companies(figure 5): 3m crowns, kids crown and rihany crowns for each size of the stainless steel crowns ( sizes: 2,3,4,5,6,7) . figure 3: the maxillary and mandibular cast analyzing using 3 shape orthoanalyzer program. analyzing using 3 shape orthoanalyzer program. 22 j bagh college dentistry vol. 33(1), march 2021 comparison between the the md dimension representative of each tooth and stainless steel crown was calculated by measuring the greatest distance between the midpoints of the mesial and distal contact points (14). figure 5: 3m crowns, kids crowns, rihany crowns. statistical analyses were carried out using the ibm spss statistics version 26 usa. the descriptive statistics means, standard deviations, maximum and minimum values of the mesiodistal width for primary second molars and the stainless steel crowns were recorded. for comparison ,paired sample t-test were applied to compare between right and left molars, and independent sample t-test were applied to compare between boys and girls. one sample t-test was used to compare the mean values of md of the second primary molar with each size of the stainless steel crowns. results for the md measurement for maxillary and mandibular right and left second primary molars, (table 1) showed the descriptive statistics for the maxillary right second primary molar (max re), maxillary left second primary molar (max le), mandibular right second primary molar (man re) and mandibular left second primary molar (man le), and the least measurement value was recorded in the maxillary second primary molars for the girl’s sample (8.00) mm. with the highest value recorded in the mandibular second primary molars for the boys sample (11.60) mm. while the mean values revealed that the highest mean value recorded for the mandibular second primary molars in the boy’s sample (9.83) mm. and the least value for the maxillary second primary molars in the girls sample (8.80) mm. also (table 1) showed, statistically by the application of paired sample t-test to compare between the right and left sides of maxillary and mandibular md width of second primary molars for both genders, the comparison revealed a nonsignificant difference between sides except in the maxillary md measurement in boys’ sample, but the difference between sides about 0.04 mm. table 1: comparison between right and left sides differences of maxillary and mandibular md width of second primary molars for both genders. table 2: comparison between the mean md values of the maxillary and the mandibular second primary molars between both genders. md (boys) n min max mean sd sig. (2tailed) md (girls) n min max mean sd sig. (2tailed) max re 27 8.29 9.90 9.1926 .44561 .043 max re 28 8.00 10.00 8.8182 .51159 .318 max le 27 8.30 9.87 9.1330 .43137 max le 28 8.00 10.00 8.8007 .52127 man re 27 8.70 11.40 9.7833 .57805 .093 man re 28 8.50 11.50 9.5439 .59936 .077 man le 27 8.60 11.60 9.8326 .59155 man le 28 8.60 11.50 9.5732 .57915 mean sig. (2tailed) mean sig. (2tailed) pair 1 max e boys 9.1628 .000 pair 2 man e boys 9.8080 .031 max e girls 8.8095 man e girls 9.5586 23 j bagh college dentistry vol. 33(1), march 2021 comparison between the (table 2) the comparison between both genders statistically done by application of the independent sample t-test to compare the mean value of the second primary molars , and the result showed a highly significant difference, with the boys recorded higher mean values than girls. one-sample test were applied to compare the md mean values of the second primary molars for boys’ and girls’ sample in both arches with the md width of stainless steel crowns of three manufactures (3m crowns, kid's crown, rihany crowns) with, and the results showed: 1for the 3m crown type, there's a highly significant difference for all md measurements except for size maxillary 2 in boys sample and size mandibular 3 for the boys sample, which showed a non-significant difference, although there's a convergence of values between the mean value of size mandibular 2 which is about (9.4 mm.) with that of the girls sample in mandibular second primary molars (9.55 mm.) but statistically showed a significant difference (table 3). 2the measurement of the kids crown type showed that there's a highly significant difference for all md measurements except for size maxillary 2 in the girls sample and size mandibular 5 for the boys sample (table 4). 3the rihany crowns type, there's a highly significant difference for all md measurement except for the size mandibular 5 crowns in the boy’s sample, which is equal values about (9.8 mm.). although there's a convergence of values between the mean value of size mandibular 3, which is about (9.8 mm.) with that of the girl’s sample in mandibular second primary molars (9.55 mm.) but statistically showed a significant difference (table 5). table 3: comparison between the md measurements of 3m ssc with second primary molars. table 4: comparison between the md measurements of kids crown ssc with second primary molars. table 5: comparison between the md measurements of rihany ssc with second primary molars. 3m crown sizes mean ssc md max e boys sig. (2tailed) max e girls sig. (2tailed) 3m crown sizes mean ssc md man e boys sig. (2tailed) man e girls sig. (2tailed) 2 9.2 9.1628 .533 8.8095 .000 2 9.4 9.8080 .000 9.5586 .047 3 9.6 9.1628 .000 8.8095 .000 3 9.8 9.8080 .920 9.5586 .003 4 10.0 9.1628 .000 8.8095 .000 4 10.2 9.8080 .000 9.5586 .000 5 10.4 9.1628 .000 8.8095 .000 5 10.6 9.8080 .000 9.5586 .000 6 10.8 9.1628 .000 8.8095 .000 6 11.0 9.8080 .000 9.5586 .000 7 11.2 9.1628 .000 8.8095 .000 7 11.4 9.8080 .000 9.5586 .000 kids crown sizes mean ssc md max e boys sig. (2tailed) max e girls sig. (2tailed) kids crown size mean ssc md man e boys sig. (2tailed) man e girls sig. (2tailed) 2 8.9 9.1628 .000 8.8095 .191 2 8.9 9.8080 .000 9.5586 .000 3 9.6 9.1628 .000 8.8095 .000 3 9.1 9.8080 .000 9.5586 .000 4 9.9 9.1628 .000 8.8095 .000 4 9.4 9.8080 .000 9.5586 .047 5 10.4 9.1628 .000 8.8095 .000 5 9.9 9.8080 .249 9.5586 .000 6 10.6 9.1628 .000 8.8095 .000 6 10.2 9.8080 .000 9.5586 .000 7 11 9.1628 .000 8.8095 .000 7 10.5 9.8080 .000 9.5586 .000 rih. crown sizes mean ssc md max e boys sig. (2tailed) max e girls sig. (2tailed) rih. crown sizes mean ssc md man e boys sig. (2tailed) man e girls sig. (2tailed) 2 7.3 9.1628 .000 8.8095 .000 2 7.7 9.8080 .000 9.5586 .000 3 7.6 9.1628 .000 8.8095 .000 3 8.6 9.8080 .000 9.5586 .000 4 8.5 9.1628 .000 8.8095 .000 4 9.3 9.8080 .000 9.5586 .000 5 9.3 9.1628 .024 8.8095 .000 5 9.8 9.8080 .920 9.5586 .003 6 9.5 9.1628 .000 8.8095 .000 6 10.2 9.8080 .000 9.5586 .000 7 9.8 9.1628 .000 8.8095 .000 7 10.4 9.8080 .000 9.5586 .000 24 j bagh college dentistry vol. 33(1), march 2021 comparison between the discussion stainless steel crowns have been commonly used for the restoration of primary and permanent posterior teeth since humphrey's introduction in 1950. no other restoration for primary teeth compares to the ease of use, longevity, and dependability of these full coverage crowns (21) . the mesio-distal dimension (md) have different terms that have used, such as tooth width (22,23) . mesiodistal width (24) tooth breadth (25) and mesiodistal crown diameter (17). the greatest distance between the normal contact areas on the proximal surfaces of the tooth crowns, measured parallel to the occlusal plane (26). the md should be taken with the calipers parallel to both the occlusal and buccal (vestibular) surfaces, according to some researchers (25) . according to moorrees et al. in 1957, md was calculated by measuring the greatest distance between the contact points when keeping calipers parallel to both the occlusal and vestibular surfaces (14). the three companies of ssc that selected in the present study were the most commonly available for the restoration of primary molars in iraq\ baghdad; 3m ssc, the kids ssc and the rihany crowns. the most important indications for using ssc as a restorative material for primary and young permanent teeth with extensive or multiple caries, hypoplasia, developmental anomalies, after teeth that treated with pulpotomy or pulpectomy, teeth with fractures and for the primary teeth that serve as abutments for space maintainers, orthodontic appliances and habit breaking appliances. recently the ssc introduced for the hall's technique which is an alternative form of treating caries in primary molars that requires the placement of a stainless steel crown without the need for tooth preparation or caries removal, and it is limited to asymptomatic teeth with no symptoms of pulpal inflammation, necrosis, or periodontal involvement. dr. norna hall of scotland was the first to use the technique in 1988, and it has gradually risen in popularity in the united kingdom, showing promise in evidencebased science (8,27). the md measurement of the second primary molars: the mesiodistal width of each molars and stainless steel crowns were measured at the widest distance between the contact points .the md mean values of the second primary molars of the boys and girls groups in the present study showed that there's a non-significant difference between right and left sides for the maxillary and mandibular teeth in both genders (28,29), except in boys maxillary second primary molars the right side slightly larger than the left side about 0.04mm. with a significant difference statistically, this comes in accordance with tejero et al. study that found significant differences between right and left teeth for the deciduous maxillary second molars (30). accordingly , the left and right sides mean values of second primary molars md were merged together and genders comparison were performed using independent sample t-test which revealed high significant genders difference with the boys recorded higher md measurements than girls this finding come in accordance with other studies found significant gender differences in the width of the primary second molars between genders. (31,32, ,33,34,35). the md measurement of the stainless steel crowns: the kids crown company it manufactured in korea while the 3m crowns and rihany crowns were made in the united states of america. for the primary posterior teeth, these crowns come in a range of sizes (sizes 2, 3, 4, 5, 6, 7). since the dimensions of these crowns seem to have been calculated based on the manufacturing country's epidemiologic data, the key question here is whether these crown sizes are appropriate for use in iraqi children's teeth. in order to explain this, we measured the mesiodistal (md) dimensions of stainless steel crowns of the three mentioned companies and then compared statistically with the corresponding values of second primary molars on the study casts in iraqi children at the mixed dentition stage. the results revealed that for the 3m company, the md measurement from size 2-7 the difference between each size increase 0.4 mm. and the most suitable size used for the maxillary second primary molars is number 2 for the boys group with no significant difference between them, and showed that the values almost equal 9.2 mm and 9.16 mm for the stainless steel crowns and maxillary second primary molar respectively. at the same time, the girls group showed a highly significant difference for all sizes, although there are nearby values in size 2, about 9.2 mm, the md of the crown with 8.8 mm. 25 j bagh college dentistry vol. 33(1), march 2021 comparison between the the md width of the maxillary second primary molar. while the mandibular 3m crowns sizes show no significant difference only in size 3 for the boys group that recorded equal values about 9.8 mm. for md of the stainless steel crowns and mandibular second primary molar respectively, with a high significant difference for the remaining sizes 2, 4,5,6,7. although for the girls group, there's also a highly significant difference in all sizes with only a nearby value between crown size 2 about 9.4 mm with that of mandibular second primary molar md dimension about 9.5 mm. this limitation in the available sizes for iraqi md measurement of the second primary molars may be due to the smaller md mean values than those of american children according to previous american studies on white children (36,37). the kids crown md measurement found that all the values in the maxillary crown showed that the difference between sizes from 2-7 is unequal number; the increase include 0.7, 0.3, 0.5, 0.3, 0.4 mm between each size. statistically, there's a highly significant difference in all sizes except size 2 maxillary crown, which is about 8.9 mm., with the md dimension of maxillary second primary molars about 8.8 mm. in the girl’s group, which show a non-significant difference statistically. regarding the mandibular crown’s md measurement, the difference between each size from 2-7 is 0.2, 0.3, 0.5, 0.3, 0.3 mm. the results statistically showed that, there's a non-significant difference in size 5 crown about 9.9 mm with the corresponding tooth md bout 9.8 mm for the boy’s group with a highly significant difference recorded for the remaining sizes although size 4 crown about 9.4 mm is nearby to the md measurement of the mandibular second primary molars about 9.5mm. in the girls group. also, this limitation in the presence of suitable sizes for iraqi children is the difference in the mean values of md measurement in which the korean children exhibit a larger md dimension of the second primary molars than those of iraqi (37). the measurement for the rihany crowns, which is an old company and made in the usa, showed that the maxillary crowns the differences between sizes from 2-7 are 0.3, 0.9, 0.8, 0.5, 0.3 mm. while for mandibular crowns, the difference between each size is 0.9, 0.7, 0.5, 0.4, 0.2mm. after analyzing the data statistically by comparing between the stainless steel crowns sizes and the md measurement of the second primary molars revealed a highly significant difference for the whole sizes of the maxillary and mandibular crowns with one value showed a non -significant difference in size 5 mandibular crown about 9.8 mm. with an equal md measurement of second primary molars about 9.8 mm. of the boys group. also, the maxillary crown size 5 showed a significant difference with nearby values 9.3 mm with 9.16 mm. in the boys group. another comparable value is seen in the girls group, the mandibular second primary molars about 9.5 mm. with the md measurement of size 5 mandibular crown about 9.8mm. from the above, the preferred sizes that fit the second primary molars for iraqi children are limited to the small sizes ranging from 8.8mm. to size 9.8mm. for the boys and girls’ pediatric patients and these sizes are the most commonly consumed from the stainless steel crowns kits. any modification for the unfitted size of stainless steel crowns; smaller or larger size, lead to lack of adequate marginal adaptation the tooth, which is considered to be the main cause of microleakage around these crowns (38). the uses of large stainless steel crown size 10mm. and above of the three companies are not applicable for the iraqi second primary molars width, but they may be useful for the first permanent molars in iraqi children since the md of this tooth ranging from 10mm. to 10.6mm. according to a previous iraqi studies (29,39). the manufacturing companies must consider the variations in md width of the primary teeth between different populations before the production of stainless steel crowns. by doing this, dental practitioners may save the time consuming for crown preparation, which is particularly very important when treating young, uncooperative children. conclusions there are not enough scientific researches in our country about the size measurements of stainless steel crowns and whether they are suitable for primary molars of iraqi children because such measurement is useful for clinical practice. regarding the md measurement of stainless steel crowns, including the three companies that are widely available in iraq, it seems that only a few smaller sizes were applicable for use in daily clinical practice for iraqi children, according to the 26 j bagh college dentistry vol. 33(1), march 2021 comparison between the recorded measurement of the present study. those facts are essential to know when using sscs of standardized size with the aim of avoiding improper fit crowns. researches need to be applied using other stainless steel crown companies to find the relation in the mesiodistal measurement with primary molars of iraqi populations. references 1. nicola p t innes 1, david ricketts, lee yee chong, alexander j keightley, thomas lamont, ruth m santamaria ,preformed crowns for decayed primary molar teeth. cochrane database syst rev, 2015. 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4:113-22. 33. marin jm, barber e, moreno jp, planells p, de nova j, costa f. study the mesio-distal diameters of the teeth in a population spanish children. pediatr odont 1993; 2 (2): 67-76. 34. hattab, f., odontometric study of deciduous and permanent teeth in jordanians. dental news, 1997. 4: p. 17-24. 35. black, t.k., 3rd, sexual dimorphism in the toothcrown diameters of the deciduous teeth. am j phys anthropol, 1978. 48(1): p. 77-82. 36. warren, j.j., s.e. bishara, and t. yonezu, tooth sizearch length relationships in the deciduous dentition: a comparison between contemporary and historical samples. am j orthod dentofacial orthop,2003.123(6): p.614-9. 37. dong-hyuk im , tae-woo kim , dong-seok nahm , young-il chang, spacing and crowding of the primary dentition in korean children relationship to tooth sizes and dental arch dimension. the korean journal of orthodontics, 2006. 38. bahman seraj , mahdi shahrabi, pouria motahari, rahil ahmadi, sara ghadimi, shahram mosharafian, kaveh mohammadi, mohammad javad kharazifard, microleakage of stainless steel crowns placed on intact and extensively destroyed primary first molars: an in vitro study. pediatr dent, 2011. 33(7): p. 525-8. 39. 39.ahmed z. diab b. the effect of nutritional status on mesiodistal and bucco/ lingual or palatal diameters of permanent teeth among fifteen years old students. jbcd 2016 june;28(2):108-14. articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. :المستخلص نظرا لالختالف بين احجام االسنان بين الشعوب المختلفة , تهدف هذه الدراسة إلى مقارنة العرض األنسي لألضراس اللبنية الثانية في سنوات مع العرض االنسي للتيجان المصنوعة من الفوالذ المقاوم للصدا وذلك بسبب 98أعمارهم األطفال العراقيين الذين تتراوح .التباين التشريحي في تشريح األسنان بين المجموعات السكانية المختلفة يارهم من مجموعتي ضرًسا لبنيا" سليما" للفك العلوي والفك السفلي تم اخت 220المواد والطرق: أجريت هذه الدراسة المقطعية على العراق. تم قياس األبعاد المتوسطة لألسنان المختارة وتيجان الفوالذ المقاوم \الذكور واإلناث من مدارس ابتدائية مختلفة من مدينة بغداد امل باستخدام للصدأ للفك العلوي والفك السفلي من ثالث شركات مختلفة باستخدام ماسح ضوئي ثالثي األبعاد ، واحتساب القياس بالك (3shape orthoanalyzer) برنامج وعند مقارنة العراض االنسي لالضراس اللبنية وجدت أنه احصائيا" اليوجد فرق بين الجهتين اليمين واليسار تم تسجيل فرق ذو داللة التيجان المصنوعة من الفوالذ إحصائية مع قيم متوسطة أعلى لألوالد من البنات وعند مقارنة نفس القياس األنسي بين األضراس مع .المقاوم للصدأ ، تم العثور على أحجام محدودة فقط من التيجان الفوالذية المقاومة للصدأ مناسبة ألضراس األطفال العراقيين في القياس ا للصدأ إليجاد العالقة اخرى مصنعة للتاج الفوالذ المقاوم شركات باستخدام تطبيق المزيد من الدراسات لوسطي يجب .المتوسط للسكان العراقيين https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ suha.doc j bagh college dentistry vol. 27(2), june 2015 effect of zinc basic sciences 178 effect of zinc oxide nanoparticles on total salivary peroxidase activity of human saliva (in vitro study) suha t. abd, b.d.s. (1) abbas f. ali, b.d.s., ph.d. (2) abstract background: the potential use of zinc oxide and other metal oxide nanoparticles in biomedical are gaining interest in the scientific and medical communities, largely due to the physical and chemical properties of these nanomaterials. the present work revealed the effect of zinc oxide nanoparticles (znonps) on the total salivary peroxidase enzyme activity of human saliva in comparison to de-ionized water. materials and methods: forty eight unstimulated saliva samples were collected from dental students/university of baghdad 18-22 years. then measure the total salivary peroxidase activity first without any addition to human saliva as a control, second with dilution the saliva with de-ionized water, and third with zinc oxide nanoparticles in concentration (5.8 mg/ml). results: the results showed that there was significant inhibition of the activity of the total salivary peroxidase enzyme in the presence zno nps and non-significant inhibition of enzyme activity in the presence de-ionized as compared with control group. conclusion: zinc oxide nanoparticles have inhibition effect on total salivary peroxidase activity key words: total salivary peroxidase activity, zno nps, human saliva. (j bagh coll dentistry 2015; 27(2):178-182). introduction nanoparticles have many different effects on human health relative to bulk material from which they are produced (1).nanotechnology has attracted global attention because nanoparticles (nps) have properties unique from their bulk equivalents. nps of ag, cuo and zno are being used industrially for several purposes including amendments to textiles, cosmetics, sprays, plastics and paints (2). in recent years zno has received considerable attention because of its unique optical, piezoelectric, and magnetic properties (3). zno nps has been reported to have extremely good safety profile and no toxicity observed when taken at different nano sizes of the zinc particles (4). nanoparticles have large specific surface areas for adequate protein binding and biological interactions (5); this revealed the great effect of znonps on total salivary peroxidase activity. zinc oxide nanoparticles (zno nps), is an inorganic white powder and is insoluble in water (6). zno is present in the earth crust as a mineral zincite; however, most zno used commercially is produced synthetically. zno is nontoxic and is compatible with human skin making it a suitable additive for textiles and surfaces that come in contact with human body (7). it is well known that many antimicrobial proteins in saliva interact in vitrowith each other. (1) master student, department of basic science, college of dentistry, university of baghdad. (2) assist. professor, department of basic science, college of dentistry, university of baghdad. the interactions result in additive, synergistic, or inhibitory effects on mutans streptococci, lactobacilli, or fungi. the main oral innatedefense factors are the peroxidase systems, lysozyme, lactoferrin, and histatins (8). peroxidase is an enzyme secreted from mammary, salivary, and other mucosal glands (9) that functions as a natural antibacterial agent (10). nanoparticles (nps) have some advantages over small organic molecules. first, nps have large specific surface areas for adequate protein binding and biological interactions (11). second, nps can enter cells easily (12), in contrast to some small molecules and biological molecules. third, there has been considerable progress in the synthesis of nps with well controlled dimensions, geometry, and surface properties (13), to complement the structural complexity of proteins (14). recent developments in nanomaterials offer a new pathway for controlling protein behavior through surface interactions.the enzyme was less stable on nanoparticles surfaces than in free solution, and the stability was decreased further on larger particles with smaller surface curvature.although the protein may retain most of its native structure after adsorption on the nps surface. in some cases the thermodynamic stability of the protein is decreased, making the protein more sensitive to chemical denaturants such as urea (15). materials and methods zinc oxide nanoparticles provided from ministry of sciences and technology, with concentration 5.8 mg/ml for stock solution and the particles size >50 nm papered by sol gel method. j bagh college dentistry vol. 27(2), june 2015 effect of zinc basic sciences 179 we make different concentration from the stock solution by using dilution low (nv = nv).to confirm the activity of zinc oxide nanoparticles solution we make the uv visspectra of zno nps was shown in (figure1). the absorption peak of the pre1pared zno nps was found at around 400-500 nm. collection of saliva samples unstimulated (resting) whole saliva samples were collected (fromforty eight dental students collage of dentistry / university of baghdad) under resting conditions between 8.0-11.0 a.m. students were asked to rinse their mouth with water and to generate saliva in their mouth and to spit into a wide test tube. the collection period was twenty minutes. following the collection, the saliva was centrifuged at (2000 rpm) for 10 minutes. the resulting supernatant was stored at– 20 °c in polyethylene tubes until assayed. determination of total salivary peroxidase activity salivary peroxidase activity was determined colorimetrically. wide variety of hydrogen donors have been utilized in peroxidase assay systems. in this study an improved assay was adopted using 4aminoantipyrine as hydrogen donor (16). the activity is determined by measuring the increase in absorbance at = 510 nm resulting from the decomposition of hydrogen peroxide per time of incubation (δa/min). reagents 1. phosphate buffer (0.2 m) ph 7.0 aa weight of 2.72 gm of kh2po4 was dissolved in 100 ml de-ionizedwater. ba weight of 3.48 gm of k2hpo4 was dissolved in 100ml of de-ionized water. 60 ml of solution b is adjusted to ph 7.0 by adding appropriate amount of solution a. 2. hydrogen peroxide (0.0017 m) this solution was prepared by diluting 1 ml of 30% hydrogen peroxide to 100 ml with de-ionized water; further dilution was carried out where 1 ml of this was diluted to 50 ml with (0.2m) potassium phosphate buffer (ph 7.0). this solution was prepared fresh daily. 3. 4-aminoantipyrine (0.0025 m) with phenol (0.17 m) this solution was prepared by dissolving 0.810 gm phenol in 40 ml de-ionized water, and then 0.025 gm of 4-aminoantipyrine was added, and diluted to a final volume of 50 ml with deionizeds solution should be kept in a brown bottle. procedure for determination of tsp activity (16). 1the following solutions were pipetted into test tube: solution test tube phenol / 4-aminoantipyrine solution 1.4 ml 0.0017m hydrogen peroxide 1.5 ml 2the test tube was incubated at 25cº for 3-4 min. to achieve temperature equilibration. 3-the reaction was initiated by the addition of (0.1ml) of the sample (saliva), with mixing. the increase in the absorbance at wave length λ = 510 nm, was recorded for 5 minutes, to obtain δa/min. calculations of tsp enzyme activity difference in absorption per unit time (δa/min) was calculated, sinceδa is the difference in absorbance between zero time and 5 minutes. one unit represents the decomposition of one µmole of hydrogen peroxide per min. at 25˚c and ph = 7 under the specified conditions according to this equation (17): peroxidase activityu/l = 10 6 where: vt = total volume(3 ml) vs = sample volume(0.1ml) δa/min = (abs.at 5 min – abs. at the zero time)/incubation time (5min.) = extiniction coefficient of phenol (50.000 l/mol/cm) u/l = μmol / minute /liter of the sample. effect of zno nps on total salivary peroxidase enzyme activity a stock solution (5.8 mg/ml) concentration of zinc oxide nanoparticles. the concentration of the nanoparticles are prepared by diluting with saliva using the stock solution. total salivary peroxidase activity is measured in human saliva by using the same method with replace the ratio of 100% of saliva for the control by ratio70% saliva and 30% zno nps solution from the stock solution only. so the final concentration of zno nps solution became as fellow: 5.8 * 70/100 = 4.06 mg/ml. while for diluting by de-ionized water we use 70% saliva and 30% de-ionized water. j bagh college dentistry vol. 27(2), june 2015 effect of zinc basic sciences 180 results one of the groups (saliva + zno nps) for the total salivary peroxidase enzyme activity is not normally distributed significance p < 0.05 by kolmogorov-smirnov test; this revealed a lack of normal distribution of data. therefore, nonparametric kruskal-wallis and mannwhitney u tests were used for data analysis with spss 14 statistical software at a 0.05 significance level.test for test of normality (table 1). descriptive statistics for the total salivary peroxidase activity measured in u/l used to examine the differences among three different groups of total salivary peroxidase activity (table 2), each group consist of 48 tests for saliva + deionized water group, saliva+ zno nps group and 18 tests for the control group, while the (figure 2) show only mean and sd of inhibition zones for three different groups. results of kruskal-wallis test showed highly significant differences among the three groups p< 0.01(table3). further analysis using a mann-w hitney u test was done to determine which of the three study groups was different from the other groups. the results of mann-whitney u test for the three groups showed highly significant p< 0.01 between (control groupzno nps group) and between (de-ionized water groupzno nps group), while for the (control group de-ionized water group) show no significance p > 0.05 as shown in (table 4). . figure 1: uv-vis spectra of the zno nps table 1: test of normality of groups of total salivary peroxidase enzyme activity kolmogorov-smirnov test activity groups sig. control (saliva only) 0.168 saliva +de-ionized water 0.200 saliva+ zno nps 0.034 table 2: descriptive statistics for the total salivary peroxidase activity in u/l groups median mean no. sd max. min. interquartilerange control(saliva only) 6.24 6.66 18 2.02 10.44 3.84 3.51 saliva + de-ionized water 5.88 5.55 48 2.02 8.76 1.92 2.73 saliva+ zno nps 0.84 0.92 48 0.48 1.68 0.12 0.84 table 3: effect of zno nps on tsp activity groups n mean rank kruskal-wallis h test activity control (saliva only) 18 88.06 chi-square= 83.702 df= 2 p <0.01hs saliva + de-ionized water 48 79.04 saliva + zno nps 48 24.50 j bagh college dentistry vol. 27(2), june 2015 effect of zinc basic sciences 181 table 4: mann-whitney u test among different three groups groups median mean rank u value zvalue p value sig. control (saliva only) 6.24 40.06 314.00 1.70 0.09 ns saliva + de-ionized water 5.88 31.04 control (saliva only) 6.24 57.50 0.00 6.23 < 0.01 hs saliva+ zno nps 0.84 24.50 saliva + de-ionized water 5.88 72.50 0.00 8.45 < 0.01 hs saliva+ zno nps 0.84 24.50 figure 2: effect of zno nps on total salivary peroxidase activity discussion kolmogorov-smirnov test revealed a lack of normal distribution of data. therefore, nonparametric kruskal-wallis and mannwhitney u tests were used for data analysis with spss 14 statistical software at a 0.05 significance level.the results of effect of zinc oxide nanoparticles on total salivary peroxidase activity shown in figure (2) and table (4). the activity of the enzyme in saliva only without any addition was considered as control and was equal to (6.66 ± 2.02u/l) while other results showed difference in the control value with the same units, the same procedure and same condition from ph and temperature, the normal value of total salivary peroxidase enzyme in control group was equal to (24.24± 18.85). this reflects high difference of enzyme activity in saliva that may affected by any variation in procedure (16,17).for the comparison of control (which contain saliva only) and de-ionized watergroup (which contain saliva70% and 30% deionized water) no significant decrease in comparison with the control (p>0.05) with decreasing the activity to (5.55± 2.02) these results may be attributed to dilution of saliva by de-ionized water. the biochemical tests revealed that zno nps in concentration of 30% saliva and 70% zno nps from the stock (5.8mg/ml) which is equal to (4.06 mg/ml) solution caused inhibitory effects on total salivary peroxidase enzymes activities, as shown in (figures 4). this inhibition may be attributed to heavy metals which are toxic and react with proteins, therefore they bind protein molecules. heavy metals strongly interact with thiol groups of vital enzymes and inactivate them. these results agree with that of chudasama et al. (18). in addition, it is believed that zn bind to functional groups of proteins, resulting in protein deactivation and denaturation. this fact strongly agrees with other results (19,20). the present study hypothesizes that zno nps interact with functional groups of tsp enzymes, resulting in protein denaturation and inactivate it, and as a conclusion, the znonps inhibited the enzyme. our work could not be compared to other work exactly because as far as we know this is the only study that demonstrates the effects of zinc oxide nanoparticles solution on the activities of total salivary peroxidase enzyme activity. as conclusion; zinc oxide nanoparticles have inhibition effect on total salivary peroxidase activity in comparison to de-ionized water. references 1. albrecht ma, evans cw, raston cl. green chemistry and the health implications of nanoparticles. j green chem 2006; 8: 417-20. j bagh college dentistry vol. 27(2), june 2015 effect of zinc basic sciences 182 2. muller nc, nowack b. exposure modeling of engineered nanoparticles in the environment. environ sci techno 2008; 42(12): 4447-53. 3. marcus cn, paul aw. zno tetrapod nanocrystals. j mater today 2007; 10(5): 50-4.[www.ivsl.org] 4. jiang w, mashayekhi h, xing b. bacterial toxicity comparison between nanoand micro-scaled oxide particles. environmental pollution 2009; 157(5): 1619-25. 5. gadek tr, nicholas jb. small molecule antagonists of proteins. biochem parmacol 2003; 65: 1-8. 6. takahashi y, yoshikawa a, sandhu a.wide bandgap semiconductors: fundamental properties and modern photonic and electronic devices. 1st ed. springer; 2007. 7. abhulimen iu, chen xb, morrison jl, rangari vk, bergman l, das kk. synthesis and characterization of zno nanoparticles. mater res soc symp proc 2004; 829: b2.27 8. mansson-rahemtulla b, baldone dc, pruitt km, rahemtulla f. effects of variations in ph and hypothiocyanite concentrations on s. mutans glucose metabolism. dent res 2008 66: 486-91. 9. tenovuo jo. the peroxidase system in human secretions. in tenovuo jo, pruitt km (eds.). the lactoperoxidase system: chemistry and biological significance. new york: dekker; 1985. p. 272. 10. pruitt km, reiter b. biochemistry of peroxidase systems: antimicrobial effects. in tenovuo jo, pruitt km (eds.). the lactoperoxidase system: chemistry and biological significance. 1985. p. 272. 11. erkizan hv, kong yl, merchant m,schlottmann s, barber-rotenberg js, yuan ls, abaan od, chou th, dakshanamurthy s, brown ml, ueren a, toretsky ja. a small molecule blocking oncogenic protein ews-fli1 interaction with rna helicase a inhibits growth of ewing’s sarcoma. nature med 2009; 15: 750-6.[www.ivsl.org] 12. porter ae, gass m, muller k, skepper jn, midgley pa, welland m. direct imaging of single-walled carbon nanotubes in cells. nat nanotechnol 2007; 2: 713-7. 13. lo conte l, chothia c, janin j. the atomic structure of protein-protein recognition sites. mol bio 1999; 285: 2177-98. 14. mu qx, liu w, xing yh, zhou hy, li zw, zhang y, ji lh, wang f, si zk, zhang b, yan b. protein binding by functionalized multiwalled carbon nanotubes is governed by the surface chemistry of both parties and the nanotube diameter. j phys chem c 2008; 112: 3300-7. 15. shang l, wang y, jiang j, and dong s. phdependent protein conformational changes in albumin gold nanoparticle bioconjugates. a spectroscopic study. langmuir 2007; 23: 2714-21. 16. trinder p. determination of glucose in blood using glucose oxidase with an alternative oxygen acceptor. am clin biochem 1966; 6: 24. 17. daoud r. study of some biochemical changes in serum, saliva of patients with oral epithelial tumors: philosophy in clinical biochemistry. ph.d. thesis, university of baghdad, 2008. 18. chudasama b, vala ak, andhariya n, mehta rv, updhyay rv. highly bacterial resistant silver nanoparticls: synthesis and antibacterial activities. j nanopat res 2010; 12: 1677-85. 19. elechiguerra jl, burt jr, morones. interaction of silver nanoparticles with hiv-i. j nano biotechnol 2005; 3: 1-10. 20. raffi m, hussainf, bhatti tm, akhter ji, hameed a, hasan mm. antibacterial characterization of silver nanoparticles against e. coli atcc-15224. j mater sci technol 2008; 24(2):192–196. http://www.ivsl.org http://www.ivsl.org mayada final.doc j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 79 immunohistochemical evaluation of vascular endothelial growth factor and transforming growth factor-beta on osseointegration of cpti implant radiated by low level laser therapy mayada k. jaafar, b.d.s. (1) eman i. altamemi, b.d.s., m.sc. ph.d. (2) abstract background: dental implants provide a unique treatment modality for the replacement of lost dentition .this is accomplished by the insertion of relatively inert material (a biomaterial) into the soft and hard tissue of the jaws, there by providing support and retention for dental prostheses. low level laser therapy (lllt) is an effective tool used to prompt bone repair and modeling post surgery; this has referred to the biostimulation effect of lllt. the aims of this study were to evaluate the immmunohistochemical expression of vascular endothelial growth factor (vegf) and transforming growth factor -beta (tgf-β) in experimental and control groups with mechanical test. materials and methods: thirty two adult new zealand white rabbits used, screw titanium implants inserted in the tibia. the right side is considered as experimental groups and the left side considered as control groups. low power diode laser (gaalas) with wave length (904nm) and (5mw) power applied with the right screw implants. the sample divided into four groups, eight rabbits are sacrificed at four interval 4days, 1 weeks, 2weeks, and 6weeks respectively. immunohistochemical (vegf&tgf-β), were done for each interval with mechanical test in 2 and 6 weeks . results: immunohistochemical findings revealed high positive expression for vegf and tgf-β in experimental implant in comparison to control one and the acceleration of bone formation and more rapid healing process in the screw implant with laser irradiation than in the control implant. removal torque test showed dramatic increase with the presence of laser irradiation especially with advancing time. conclusion: this study was illustrated that the lllt applications enhance bone formation and increase osseointegration. key words: dental implants, low level laser therapy, biochemical bone marker. (j bagh coll dentistry 2014; 26(2): 7986). الخالصة وتثبیتا إسنادا یوفر مما للفكیة والعظمیة الرخوة األنسجة في )حیویة مادة ( نسبیا خاملة مادة بإدخال ذلك یتم .المفقودة األسنان لتعویض المثلى الطریقة ھي السنیة الغرسة ان :الخلفیة وكانت اھداف ھذه الدراسة .م بعد الجراحة ، وھذا ما یسمى بالتأثیر المحفز للیزر المنخفض الطاقةعالج اللیزر المنخفض الطاقة اداة فعالة تستعمل لتحفیز اعادة بناء العظ للغرسة .مع الفحص المیكانیكي في مجامیع االختبار والسیطرة) tgf-β(وعامل تحول النمو )vegf(المناعي النسیجي الكیمیائي لعامل نمو البطانة الدمویة الوعائي التقییم )904nm(بطول موجة ) gaalas(اثنان وثالثون ارنب تحت التخدیر العام وتم تعریض اشعة اللیزر المنخفض الطاقة 32استخدم في ھذه الدراسة :واد المستخدمةطریقة العمل والم للحصول على النتائج اختبرت العینات ).وعة السیطرةمجم(وادخال غرسة التیتانیوم فقط في الفخذ االیسر ) مجموعة االختبار(مع غرسة التیتانیوم في عظم الفخذ االیمن )5mw(وقوة بعد اجراء الزرع ، تم استخدام االختبار النسیجي الكیمیائي المناعي القتفاء ظھور مستقبالت عامل نمو البطانة ) ایام ، اسبوع ، اسبوعان ، ستة اسابیع 4( كیمیائیا نسیجیا مناعیا بعد .على كافة الغرسات ولكل مراحل االلتئام مع االختبار المیكانیكي في اسبوعان وستة اسابیع فقط) tgfβ(و وعامل تحول النم )vegf(الدمویة الوعائي یجعل ان وجود اشعة اللیزر المنخفض الطاقة. نتائج الفحص الكیمیائي النسیج المناعي اظھرت مستوى ایجابي عالي الظھور في مجموعة االختبار مقارنة بمجموعة السیطرة ، : النتائج شفت النقاب عن زیادة في القوة المیكانیكیة بوجود عملیة االلتئام وتكوین العظم اسرع من عملیة االلتئام الفسلجیة الطبیعیة وفي نتائج االختبار المیكانیكي بواسطة مقیاس عزم التدویر ك .اللیزر بازدیاد الوقت ض الطاقة كانت مادة محفزة للعظم اذ سرعت عملیة التكوین العظمي حول غرسة التیتانیوم اكثر من عملیة االلتئام الفسلجیة ھذه الدراسة اكدت بان تطبیق اشعة اللیزر المنخف: االستنتاج . الطبیعیة .، عالمات العظم الكیمیائیة اللیزر المنخفض الطاقةالغرسة السنیة ، :الكلمات الرئیسیة introduction dental implants are biocompatible screw like titanium objects that are surgically placed into the mandible or maxilla to replace missing teeth. the mechanism by which an implant is biomechanically accepted by the jaw bone is called osseointegration the clinical long-term success of the implants depends on the osseointegration and the adhesion of the soft tissues and epithelium to the titanium surfaces of the implant (3). titanium is the most wide spread metal for orthopedic implants intended for bone integration. (1) master student, department of oral diagnosis, college of dentistry, university of baghdad. (2)assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. it represents high fatigue strength and comparatively low modulus of elasticity, respect to other metals, so it is able to support loads and distribute them to bone, limiting stress shielding. besides titanium is characterized by a thin natural oxide layer on the surface that limits ion release and reactivity, making the surface almost inert and biocompatible (4). several treatments have been proposed to improve and accelerate bone formation onto implant surface, among which low-level laser therapy (lllt) (5). lllt known as cold laser, soft laser, biostimulation, or photobiomodulation, it basically exposes cell or tissue to laser or lowlevel red or near-infrared (ir) light generated from light-emitting diode. lllt stimulates or controls cellular function to minimize the extinction of cell or tissue, accelerates the healing j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 80 of fractures, fast recovery from the damage of soft tissue, nerve, bone, and cartilage, and relieves acute and chronic pain and inflammation (6). transforming growth factor-beta (tgf-β), the largest source of which is bone, has been implicated in osteoblast proliferation and differentiation and is expressed at high levels during bone growth and development with an adequate blood supply (7). vascular endothelial growth factor (vegf), which is secreted by many cells including osteoblasts and osteoblast-like cells, plays an important role for adequate angiogenesis and may be intimately related to bone development and fracture healing because both intramembranous and endochondral ossifications are associated with capillary development.. these two proteins are associated with osteogenesis during bone growth, development, and healing; but they do not stimulate stem cells or bone progenitor cells to generate to be osteoblasts as directly as bone morphogenetic proteins (bmps). however, these proteins have efficacy on not only cell migration and propagation but also on angiogenesis indispensable for bone formation (7). materials and methods thirtytwo adult new zealand white rabbits male weighing 2-3kg were used in this study, screw titanium implants inserted in the tibia under general anesthesia. the right side is considered as experimental groups and the left side considered as control groups. low power diode laser (gaalas) with wave length (904nm) and (5mw)power applied with the right screw implants. the sample divided into four groups, eight rabbits are sacrificed at four interval 4days, 1 weeks, 2weeks, and 6weeks respectively. immunohistochemical (vegf&tgf-β) were done for each interval with mechanical test in 2 and 6 weeks. results expression of vegf findings at 4 days duration control group immunohistochemical findings of implant site shows positive expression of vegf in bone marrow stromal cell figure (1). experimental group immunohischemical localization of vegf in rabbit tibia shows strong positive expression of vegf in bone marrow stromal cell with the formation of primitive osteoid tissue figure (2). at 1 week duration control group woven bone are formed at implant site with weak positive expression of vegf in progenitor cell, extracellular matrix , blood vessel and osteoid tissue ,fat cell shows negative expression of vegf. dab stain with hematoxylin counter stain x200. figure (3). figure 1: positive expression of vegf in bone marrow stromal cell of implant in rabbit tibia (control) for 4 days duration dab stain with hematoxylin counter stain x100 figure 2: immunohistochemical view for positive expression of vegf in bone marrow stromal cell (bmsc) in bone marrow of implant in rabbit tibia treated with laser irradiation for 4 days duration dab stain with hematoxylin counter stain x100 j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 81 experimental group positive immunohistochemical localization of vegf is viewed in large area of newly formed woven bone, endothelial cell of blood vessel, osteoblast cell and active osteoprogenitor cell. figure (4). at 2 week duration control group micrscopical evaluation of bone section at implant site shows osteoid tissue formation that is positively expressed by vegf figure (5). experimental group bone section in rabbit tibia shows positive expression of vegf in bone trabeculae in which osteocyte are embedded and formative osteoblast are seen rimming bone surface figure (6). at 6 week duration control group micrphotograph view in rabbit tibia shows positively stained immature bone formation with numerous osteocyte that are irregularly scattered in the bone figure (7). figure 5: microphotograph of bone section in rabbit tibia after 2 weeks of implantation illustrates positive immunohistochemical localization of vegf by osteoid tissue (ot) dab stain with hematoxylin counter stain figure 3: view for positive expression of vegf in osteoid tissue (ot), progenitor cell (pg), fat cell (fc) dab stain with hematoxylin counter stain x200 figure 4: positive immunohistochemical localization of vegf in implant site of rabbit tibia for one week duration treated with laser irradiation shows positive expression o f vegf in woven bone (wb), and endothelial cell (ec) dab stain with hematoxylin counter stain x400 ec wb figure 6: magnifying view showing bone trabeculae with numerous osteocyte (oc), osteoblast on the surface of bone (ob) and havarisan canal(hc),all are positively stained dab stain with counter hematoxylin x400. j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 82 experimental group bone section at implant site shows positive localization of vegf in mature bone , bone trabeculae appear with lamellated bone , osteocyte are arranged regularly inside bone matrix , and blood vessel within bone trabeculae figure (8). expression of tgf-β findings at 4 days duration control group immunohistochemical view revealed primitive new bone formation in which future bone is formed as embryonic type.this bone is characterized by presence of progenitor cells that are scattered randomly which shows positive expression of tgf-β figure (9). experimental group positive localization of tgf-β expressed by large number of active mitotic progenitor cells , endothelial cells of blood vessel ,fat cell with surrounding extracellular matrix in bone marrow figure (10). at 1 week duration control group implant site of 1 week duration shows positive expression of tgf-β in osteoid tissue, fat cell, endothelial cell, progenitor cell with extracellular matrix figure (11). figure 9: magnifying view shows positive localization of tgfβ in progenitor cell (pg),fat cell (fc) and endothelial cell(ec) of blood vessel dab stain with hematoxylin counter stain x400 figure 7: positive immunohistochemical localization of vegf expressed by immature bone (imb) and osteocyte cell (oc) in rabbit tibia of 6 weeks duration (control) dab stain with counter hematoxylin stain x100. figure 8: view of mature bone showing bone trabeculae (bt) and osteocyte cell (oc) with regular arrangement in rabbit tibia of 6 weeks duration treated with laser irradiation dab stain with counter hematoxylin stain x 200. figure 10: positive expression of tgf β in progenitor cell (pg) ,fat cell (fc),endothelial cell (ec) and in ground substance of bone marrow in implant site treated with laser irradiation for 4 days duration dab stain with hematoxylin counter stain x400 j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 83 experimental group osteoid tissue shows positive localization of tgf-β in osteoid tissue,fatcell,endothelial cell and in progenitor cell,all are irregularly arranged within primitive bone formed at implant site figure (12). at 2 weeks duration control group microscopic evaluation of the bone section related to implant shows bone thread with bone trabeculae that are negatively stained enclosing area of woven bone figure (13). experimental group view of rabbit tibia with implant shows positive localization of tgf-β, in osteoid tissue, bone trabeculae, osteocyte cell and in marrow tissue figure (14). at 6 week duration control group positive localization of tgf-β in immature bone deposited at implant site in marrow tissue figure (15). experimental group positive expression of tgf-β in mature bone deposited at implant site, it shows havarsian bone, marrow tissue, osteocyte cell embeded in bone matrix , reversal line that separated old bone from new bone figure (16). figure 14: positive immunohisto chemical localization of tgfβ in osteoid tissue (ot) and in marrow tissue (mt) in implant site treated with laser irradiation for 2weeks duration while basal bone (bb) is negatively stain dab stain with hematoxylin x200. figure 12: view of implant site at one week duration treated with laser irradiation shows positive expression of tgfβ in osteoid tissue (ot), and progenitor cell (pg) dab stain with hematoxylin counter stain x200. figure 13: immunohistochemical localization of tgf-b in bone trabeculae (bt) of thread region in implant site of 2 weeks duration (control) dab stain with hematoxylin counter stain x100 figure 15: immunohistochemical localization of tgf-β in immature bone (imb) at implant site (control) after 6 weeks of implantation. dab stain with hematoxylin counter stain x200 j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 84 mechanical testing figure (17) shows the summary statistics of the removal torque value of cpti implants (control and experimental) after two and six weeks of implantation times, the torque value needed to remove all the implant was higher at six weeks healing period for both control and experimental groups. after 6 weeks of implantation there was an obvious increase in the means values of the torque force that were needed to unscrew the implants. the mean torque values for the implants control group was (22.75 n. cm) the highest torque mean value was obtained with implants treated with laser irradiation (25.75 n.cm). 0.00 5.00 10.00 15.00 20.00 25.00 30.00 con. 2 wk. exp. 2 wk. con. 6 wk. exp. 6 wk. 11.13 13.69 22.75 25.75 figure 17: bar chart for mean values of the studied torque removal test parameter for the two independent groups (study and control) at the two periods of times bone marrow stromal cells (bmsc) from the obvious findings we can noticed that, there was decrease in bmsc score mean values of positively stained cells for both vegf and tgf – beta, during the 4 days, 1,2 and 6 weeks of healing intervals concerning control group while the experimented group a slight increase in vegf score at 2and 6 week period, whereas the mean values of scores of tgf beta showed decrease in 2 and 6 weeks of healing intervals, as shown in figures (18, 19). figure 18: cluster bar chart for mean values of (bmsc outcomes) distributed among different of the studied sources of variations at tgf marker 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 4 days 1 week 2 weeks 6 weeks vegf con. exp. figure 19: cluster bar chart for mean values of (bmsc outcomes) distributed among different of the studied sources of variations at vegf marker bone cell the results of bone cells in present study are illustrated in figure (20). the majority of the bone cells parameter was reported at the vegf and tgf beta during healing periods, had been decreased down stair sequentially by the times periods passed of the studied trials. in addition to that, the comparisons significant among different periods of times after treatment reported anon significant differences at p>0.05 due to different markers, and the same statistical results were obtained due to comparisons significant among different periods of times in each groups ( control and experimental )at p> 0.05. figure 16: view of bone thread in implant site after 6 weeks duration treated with laser irradiation shows mature bone (mb), positive localization of tgfβ in osteocyte (oc), havarsial canal (hc) and reversalline (rl). dab stain with hematoxylin counter stain x400. 0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 4 days 1 week 2 weeks 6 weeks tgf con. exp. j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 85 1.00 1.50 2.00 2.50 2 weeks 6 weeks 2 weeks 6 weeks 2 weeks 6 weeks ob oc oscl vegf con. vegf exp. tgf con. tgf exp. figure 20: multiple line chart of the mean values for (bone outcomes) distributed among different of the studied sources of variations at vegf and tgf markers discussion all animals tolerated the implantation well, no sign of cross infection, tissue reaction or any other negative clinical indications like mobility of the implants were noted around the implants site.all implants were stable during healing periods in the sense that they could not be removed with manual force without the aid of the torque gage instrument as observed from the results of (8). the increased removal torque values for lased group comparing with control group indicates that lowenergy laser therapy( in the dose given in this study) affects osseointegration formation and bone maturation around the implant positively .this result was in agreement with (9-11) the present result based on application of lllt with implant, lllt creates a number of environmental conditions that appear to accelerate the healing of bone (12), lllt-related effects include stimulation of blood flow, recruitment and activation of osteoblasts, osteosynthesis, a decrease in osteoclastic activity and antiinflammatory action (13) could also be considered as factors that stimulate biomaterial osseointegration. vegf induces the proliferation, differentiation and migration of vascular endothelial cells and enhances their survival by preventing their apoptosis; it also increases the permeability of the capillaries (14). vegf works in both processes of endochondral ossification and intramembranous ossification acts as an essential mediator during these processes. it is involved not only in bone angiogenesis, but also in various aspects of bone development, including chondrocyte differentiation, osteoblast differentiation and osteoclast recruitment (15). therefore our results record positive expression of vegf in experimental group at 6 weeks duration. tgf-β increases bone formation mainly by recruiting osteoblast progenitors and stimulating their proliferation, thus expanding the pool of committed osteoblasts, as well as by promoting the early stages of differentiation (bone matrix production). on the other hand, it blocks later phases of differentiation and mineralization (16,17) .tgf-β increases the pool of osteoprogenitors both by inducing chemotaxis and proliferation(18). the present study suggests for beneficial use of lllt in practice of dentistry implantation or in other branch related to osseointegration process. references 1. guan h, staden rv, loo yc, johnson n, ivanovski s, meredith n.influence of bone and dental implant parameters on stress distribution in the mandible. int j oral maxillofacial imp 2009; 24: 866 76. 2. oshida y, tuna eb, aktören o, and gençay k. dental implant systems. int j mol sci 2010; 11: 1580 – 1678. 3. ghahroudi aar, talaeepour ar, mesgarzadeh a, rokn ar , khorsand a, mesgarzadeh nn, kharazi fard mj. radiographic vertical bone loss evaluation around dental implants following one year of functional loading. j dentistry, tehran university of medical sci 2010; 7: 55-123. 4. ferraris s, spriano s, pan g, venturello a, bianchi cl, chiesa r, faga mg, maina g, verne e. surface modification of ti-6al-4v alloy for biominerlization and specific biological response. part 1, inorganic modification. j mater sci mater med 2011; 11: 53545. 5. peplow pv, chung ty, baxter gd. laser photobiomodulation of wound healing: a review of experimental studies in mouse and rat animal models. photomed laser surg 2010; 28: 291-325. 6. kim yd. biophysical therapy and biostimulation in unfavorable bony circumstances: adjunctive therapies for osseointegration. j korean assoc oral maxillofac surg 2012; 38: 195-203. 7. kuroda s, sumner dr, virdi as. effects of tgf-β1 and vegf-a transgenes on the osteogenic potential of bone marrow stromal cells in vitro and in vivo. j tissue eng 2012; 3(1): 204. 8. hammed ti. histological and mechanical evaluation of electrophoretic bioceramic deposition on ti 6al7nb dental implants. a ph.d. thesis, college of dentistry, university of baghdad, 2007. 9. mohammed ifr, yonus na, al-talabani ng. histopathological study of ossenointegration around titanium implant post lllt. iraqi j oral and dent sci 2003; 2: 9-19. 10. ibrahim rs. effect of low energy laser irradiation on bone healing around intraosseous titanium implants in experimentally diabetic rabbits (morphometric and histological evaluations). a ph.d. thesis, college of dentistry, university of baghdad, 2003 11. al talabani mah. effect of 904 nm diode laser with different exposure times on titanium dental implants inserted in rabbit's tibia (histological study). m.sc. thesis, college of dentistry, university of baghdad, 2004. 12. pinheiro al, gerbi me. photo engineering of bone repair processes. photomed. laser surg 2006; 24: 16978 13. nicola ra, jorgetti v, rigau j, pacheco mt, dos reis lm, zangaro ra. effect of low power ga al as laser j bagh college dentistry vol. 26(2), june 2014 immunohistochemical oral diagnosis 86 (660 nm) on bone structure and cell activity: an experimental animal study. lasers med sci 2003; 18: 89-94 14. kyzas pa, stefanou d, agnantis nj. immunohistochemical expression of vascular endothelial growth factor correlates with positive surgical margins and recurrence in t1 and t2 squamous cell carcinoma (scc) of the lower lip. oral oncol 2004; 40: 941-7. 15. yang y, tan y, wong r, wenden a, zhang l, rabie a. the role of vascular endothelial growth factor in ossification. international j oral sci 2012; 4: 64–8. 16. alliston t, choy l, ducy p, karsenty g, derynck r. tgf-β-induced repression of cbfa1 by smad3 decreases cbfa1 and osteocalcin expression and inhibits osteoblast differentiation. embo j 2001; 20:2254–72. 17. maeda s, hayashi m, komiya s, imamura t, miyazono k. endogenous tgf-β signaling suppresses maturation of osteoblastic mesenchymal cells. embo j 2004; 23:552–63. 18. janssens k, ten dijke p, janssens s, van hul w. transforming growth factor-beta1 to the bone. endocr rev 2005; 26: 743–74. sem evaluation j bagh college dentistry vol. 26(1), march 2014 an in-vitro scan restorative dentistry 42 an in-vitro scan electron microscope comparative study of dentine-biodentine interface jameel m. a. sulaiman, b.sc., m.sc. (1) maha m. yahya, b.d.s., m.sc. (2) wiaam m.o. al-ashou, b.d.s., m.sc. (2) abstract background: this research was an in-vitro sem comparative study of dentine – biodentine tm interface. materials and methods: sixty three freshly extracted human molars, biodentine tm (septodont, france), mta (proroot, tulsa, brazil), gic (medifil, promedica, germany), light microscope, scaler and pumice, high speed hand piece, diamond bur, scan electron microscope: vega\\ easy probe. tescan – germany. the study was performed first at the university of mosul, college of dentistry to dental models were brought the sixty-three of the specialty dental health center in mosul. the teeth was prepared by cleaning, cutting, and removing all the caries and examined under light microscope and decayed teeth was excluded .then the teeth was divided randomly into three main groups (a, b, c) and each major group was divided into three sub groups: (a1, a2, a3) was filled with (biodentine tm), (b1, b2, b3) was filled with (mta) and (c1, c2, c3) was filled with the (gic). each subset contains seven (7) samples. all groups were filled according to the manufacturer instructions, and then restored at 37°c and 100% humidity. after storage periods of (7, 14, 28) days, the teeth were sectioned mesio-distaly using a low speed diamond saw (isomet, buehler ltd.), and examined under sem at the university of technology-nano research center in baghdad. results: under the condition of this in vitro study, examination with sem showed that the marginal gaps between the experimental materials and the dentine is time dependant, with the best results was observed between biodentine and dentine interface. conclusion: the marginal gaps between the experimental materials and the dentine are time dependent. keywords: interface, biodentine tm, mta, sem. (j bagh coll dentistry 2014; 26(1):42-48). الخالصة : ثالثة المواد وطرائق العمللمادةعاج السن الطبيعي مع المادة الصناعية المثيلة لها. : يهدف البحث إلى استخدام تقنية المجهر االليكتروني إلجراء دراسة مقارنة للوسط البيني األهداف :sem)، المجهر االليكتروني الماسح (gic)والـ (mta)، ومادتي الـ tm (biodentine(ـالاد مختلفة من الحشوات السنية ( عينة من األسنان الطبيعية ، ثالثة مو36وستون ) vega\\ easy probe. tescan germany) أسنان، مجهر ضوئي ، مقحلة(scaler) ومسحوق(pumice) أدوات باإلضافةإلىالماس، قاطع من، رأس األسنانجة لمعال من المركز الصحي الـثالثة والستون نماذج األسنان بعد أن تم جلبفي جامعة الموصل كلية طب األسنان أوال أجريت الدراسة الرطوبة. ف من يدوية عالية السرعة، جهاز تجفي األسنانالتخلص من لغرض جميع التسوسات وفحصها بالمجهر الضوئي وإزالةمل التنظيف والقص لتش للعمل البحثي تحضير العيناتبدأ العمل لثم التخصصي لألسنان في الموصل (لمادة الـ a)a2,a1,3(ثانوية ثالثة مجاميع إلىوالمجموعة الرئيسية الواحدةa, b, c)(وهي ثالثة مجاميع رئيسية إلىعشوائيا األسنانقسمت. المنخورة tm (biodentine ، )3,b2,b1(b لمادة الـ(mta) و)3,c2,c1(c لمادة الـ(gic) بالحشوات السنية المخصصة لهذه الدراسة ثم بدأت المعالجة . عينات (7)سبعة على تحتوي ثانوية كل مجموعة. و ألماني من شركة –(gic)الـ اما مادة ,proroot) (tulsaبرازيلي من شركة (mta)الـ ، ومادة(septodont)فرنسي الصنع من شركة biodentine) tm(وهي مادة الـ (medifil, promedica) ،لص للتخ از تجفيفهبج جميع العينات ( لكل مجموعة ، ثم جففت28 ,14 ,7وهي ) باأليامترات زمنية مختلفة ولف بالماء المقطر ميلة الخزنبدأت ع بعدها . في بغداد مركز بحوث النانوتكنولوجي –الجامعة التكنولوجية في (sem)بجهاز المجهر االليكتروني الماسح ريلتصولأرسلت بعدهاوتم تقطيعها ثم من الرطوبة وسطح tm (biodentine( مادة الـالنتائج لوحظت بين أفضلمقدار الفجوة الحاصلة بين عاج السن والمواد المفحوصة تعتمد على الزمن وان نتائج هذه الدراسة أن أظهرتالنتائج: عاج السن. مرتبط بعامل الزمن. األسنانعاج السطحية بين المواد المفحوصة وسطحمقدار الفجوة إن :االستنتاجات introduction torbinejad first developed mineral trioxide aggregate (mta) as a surgical root repair material in 1993 (1). subsequently, significant interest has been shown in mta, due to its compatibility (2) and potential bioactivity (3). more recently, a new calcium-silicate restorative material called biodentine tm has been introduced by septodent, to be used not only as an endodontic repair material but also as a coronal restorative material for dentin replacement. biodentine tm consists of a powder and liquid in apipette. the powder mainly contains tricalcium and diecalcium silicate, the principle component of portland cement and mta, as well as calcium carbonate zirconium dioxide serves as contrast medium (4). (1)lecturer. department of basic sciences. college of dentistry, university of mosul. (2)lecturer. department of conservative dentistry. college of dentistry, university of mosul. the liquid consist of calcium chloride in an aqueous solution with an admixture of modified poly carboxylate. the powder is mixed with the liquid in a capsule in a toturator for 30 seconds, sets in about 12 to 16 minutes (5). biodentine tm can be used for the treatment of root perforation or for the pulp floor, internal and external resorption, apexification, retrograde root canal obturation, pulpotomy, and also for temporary sealing of cavities and cervical filling (6). biodentine tm with active biosilicate technology announced by dental material manufacturer septodent in september of 2010, and made available in january of 2011, biodentine tm is a calcium silicate based material used for crown and root repair treatment, repair of perforation or desorption’s, apexification and root-end filling. the material has indications similar to calcium silicate based materials e.g. mta, septodent claimed that biodentine tm is not mutagenic (7) and that it can resist microleakage (8). j bagh college dentistry vol. 26(1), march 2014 an in-vitro scan restorative dentistry 43 biodentine tm shares both its indications and mode of powder in capsule and liquid in a pipette. the powder mainly contains tri calcium and dicalcium silicate, the principle component of portland cement as well as calcium carbonate, zirconium dioxide serves as a contrast medium (9). the liquid consists of calcium chloride in aqueous solution with an admixture of polycarboxylate. the powder is mixed with the liquid in a capsule in the triturate for 30 seconds. once mixed biodentine tm sets in about 12 minutes. during the setting of cement calcium hydroxide is formed. the consistency of biodentine tm reminds of that of phosphate cement (10, 11). the aim of this present study is to investigate the marginal interfaces created between biodentine tm, mta, gic and dentine. the sealing ability of these materials is assessed invitro through sem observation of the toothcement interface. materials and methods sixty three freshly extracted human molars were used for this study. after visual inspection with a light microscope to ensure that the teeth did not show any caries or cracks, the teeth were cleaned and polished with scaler and pumice. one standardized class i cavity in the occlusal surface were prepared on each tooth. all manipulations and restorations were performed by a single experienced operator to prevent variations due to operator’s skill. cavities were prepared with a high speed handpiece, using a diamond bur under heavy water spray. the diamond bur was replaced after every four preparations. all internal line angles were rounded. the overall dimensions and depths of cavities were standardized as follows: occlusal floor width 4mm, length 5mm, depth 2.5mm. the occlusal floor ended in dentine, just below the dentinoenamel junction. the teeth were immediately and randomly divided into nine groups (7 teeth for each) according to the filling material used for the restoration of the occlusal cavities and the time of storage as follow: group a: filled with biodentine and subdivided into three sub groups (a1, a2, a3) with seven teeth for each. a1: restored with biodentine and stored for 7 days a2: restored with biodentine and stored for 14 days a3: restored with biodentine and stored for 28 days. group b: filled with mta and subdivided into three groups (b1, b2,b3) with seven teeth for each subgroup. b1: restored with mta and stored for 7 days b2: restored with mta and stored for 14 days. b3: restored with mta and stored for 28 days. group c: filled with glass ionomer cement and subdivided into three groups (c1, c2, c3) with seven teeth for each subgroup. c1: restored with glass ionomer cement and stored for 7 days. c2: restored with glass ionomer cement and stored for 14 days. c3: restored with glass ionomer cement and stored for 28 days. all groups were filled according to the manufacturer instructions, and then restored at 37 °c and 100% humidity. after storage periods, the teeth were sectioned mesio-distally using a low speed diamond saw (isomet, buehler ltd.), thus passing through the center of the restoration. then the sectioned specimens were cleaned with 10% orthophosphoric acid (h3so4) for 3 to 5 seconds and quickly rinsed with air water spray for 15 seconds to remove the smear layer. later all the specimens were dehydrated by increasing concentration of ethyl alcohol [c2h5oh] (30%, 50%, 70, 90% and 100%). once the specimens were dehydrated with various concentrations of alcohol, they were mounted with silver paste on metallic stubs and gold coated with sputtering system under vacuum desiccation and then examined under sem (vega easy probe – germany),at acceleration voltage of 10 to 30 kv. the internal gaps between the dentinal surface and dentine substitute materials were observed under scanning electron microscope. representation photomicrographs were taken at a magnification power of (1000-1200) x. the internal gaps at different levels were measured in each photomicrograph and mean was taken. the values obtained in microns and the data were calculated and analyzed statistically using anova and duncan’s multiple range test at (p<0.05). results under the condition of this in vitro study, examination with sem showed that the interface between group a (biodentine tm) and human dentin were approximately in intimate contact after 28 days of storage (i.e. the gap observation was 1µm). while during the first week the mean diameter of the gaps between biodentine tm and the tooth structure was (8.1± 0.888 µm) and the j bagh college dentistry vol. 26(1), march 2014 an in-vitro scan restorative dentistry 44 interface became more intimate after two weeks, the mean diameter of the gaps was (3.16 ± 0.7638µm). and the difference between biodentine tm groups at different time was statistically highly significant (p<0.01) as seen in figure (1), table (1). the result of this in vitro study showed that in group b (mta) the mean diameter of the gaps was (54.467 ± 4.313 µm), (6.0 ± 1.0 µm) and (3.333 ± 1.528 µm) was statistically highly significant (p<0.01) as seen in figure (1), table (2), for subgroup (b1,b2 and b3) respectively. group b3represent the lowest mean of gaps which was not significantly differenced from groups b2 (p>0.05). group b1 showed the highest mean of the gaps, and the difference was significant when compared with the group b2 and b3 (p<0.05) as seen in figure (1), table (2). the results also showed that in group c (glass ionomer) the mean diameter of the gaps was (7.27 ± 0.86 µm), (25.0 ± 6.26µm) and (64.0 ± 33.81µm) for subgroup (c1, c2 and c3) respectively, and the difference was statistically significant between these groups( p<0.05)as seen in figure (1), table (3). duncan's multiple range test table(4) showed that at 7 days storage period glass ionomer group represent the lowest mean of the gaps (7.267 ± 0.862) µm which was significantly different(p<0.05)when compared with biodentine tm group (8.1 ± 0.889µm) and mta group( 54.467 ± 4.313µm) ,and difference was not statistically significant between biodentine tm and mta(p>0.05). duncan's multiple range test table (5) showed that at 14 days storage period biodentine tm group represent the lowest mean of the gap (3.167 ± 0.764 µm) which was not significantly different (p>0.05) when compared with mta group (6.0 ± 1.0 µm) and glass ionomer group (25.0 ± 6.264 µm) which showed the highest mean of gaps and the difference was highly significant when compared with biodentine tm and mta group (p<0.01). duncan's multiple range test table (6) showed that at 28 days storage period biodentine tm group represent the lowest mean of the gap (1.0 ± 0.000 µm) which was not significantly different when compared with mta group (3.33 ± 1.53 µm) and glass ionomer group (64.00 ± 33.81µm) which showed the highest mean of gaps and the difference was significant (p<0.05) when compared with biodentine tm and mta group. duncan's multiple range test table (7), figure (2), showed that at (7, 14, 28) days storage period groups (a, b, c) was highly significantly different (p<0.01). there was no significant between a1, a2, a3, b2, b3 and c1 (p<0.05), and there was no significant between b1 and c3, but there was a significant between c2 and the other subgroups. discussion the quality and durability of the interface is a key factor for the survival of a restorative material in clinical conditions; the marginal adaption and the intimate contact with the surrounding material (dentine, enamel and dental material) are determinative features (5,13). in the present study this was investigated by scan electron microscope (sem) at magnification (1000-1200) x to assess the interfacial seal between enamel and dentine and three restorative materials (biodentine tm, gic and mta). sem represents a valid tool for evaluation of the marginal integrity in in-vitro studies (14, 15). it is a widely used morphological examination of different interface (16). additionally it is used to obtain a quantitative evaluation of the extent of the marginal gaps (1719). under the condition of this in-vitro study, examination with sem should that the interface between biodentine tm and human dentine are approximately in intimate contact after 28 days of storage (the gap was 1 µm) observer between biodentine tm and the tooth structure, while during the first week the mean diameter of the gap between biodentine tm and the tooth structure was (8.1 ± 0.888 µm) and the interface become more intimate after two weeks, i.e. the mean diameter of the gaps was (3.1667 ± 0.7638µm). santos et al (20) observed that the interfacial gap of biodentine tm dentine may be compared to the hard tissue layer shown to be formed when using pro-root mta which is considered as a precipitation of hydroxyapatite. goldberg et al (21) observed that sem microphotograph showed the occurrence of a cohesive failure with biodentine tm cement with alteration of the tooth-biomaterial interfaces, hence providing evidence for the quality of the micromechanical adhesion occurring during the sem preparation table (6) showed that there is a direct contact (without a gap), between biodentine tm and the natural dentine. the cracks observed in side biodentine tm caused by dehydration due to sem sample preparation under vacuum (22). this cohesive failure dose not affected the dentine – biodentine tm interface, which indicate the quality of the micro-mechanical adhesion (23, 24). in comparison of interface of biodentine tm dentine in tables (4), (5) and (6), the interfaces were very similar in all of the subgroups (a1, a2, a3), while in group (b) the mean diameter of the gaps were gradually decreasing with time. the interface between mta and dentine became more j bagh college dentistry vol. 26(1), march 2014 an in-vitro scan restorative dentistry 45 intimate after (28) days of storage. the possible reason for the decrease in diameter of gaps is the slight expansion of mta upon setting (25, 26). the marginal adaptation of mta has been assessed using sem (27, 28), the long term seal was measured over a (12) weeks and (12) month period. these studies reported good results with mta; this may be because of its moisture tolerance and long setting time (29, 30). in the present study, group c with gic (c1, c2, c3) showed a large gap between the gic and tooth structure, and this gap is increasing with time. during setting, gic absorb a considerable amount of water, which may affect their sealing ability and physical properties. silica hydrogel forming around the glass particles is likely to act as a fluid reservoir. it also tends to undergo some amount of shrinkage during the setting which can cause loss of the marginal integrity (31,32). glass ionomer (gic) is a material with universal properties as dentist substitute; its ability to exhibit chemical bond to tooth structure provides an excellent marginal seal. however the marginal seal is compromised because of its dissolution in tissue fluids and its technique sensitivity (33). as conclusions; all of the studied materials exhibited some degree of marginal gaps that are time dependent. a positive correlation was found between the marginal adaptation and time of storage. biodentine tm and mta exhibited similar performances that are better than gic under conditions of this study. references 1. lee sj, monsef m, torabinejad m. sealing ability of a mineral trioxide aggregate for repair of lateral root perforations. j endod 1993; 19: 541–4. 2. camilleri j, montesin fe, papaioannou s, mcdonald f, pitt ford tr. biocompatibility of two commercial forms of mineral trioxide aggregate. int endod j 2004; 37: 699-704 3. tay fr, pashley dh, rueggeberg fa, loushine rj, weller rn. calcium phosphate phase transformation produced by the interaction of the portland cement component of white mineral trioxide aggregate with a 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xv, colon p, laurent p, aubut v, about i, boukpessi t, septier d, biocompatibility or cytotoxic effects of dental composites. oxford: cox moor publishing; 2009. pp. 181-203. 22. gondim e, zaia aa, gomes bp, ferraz cc, teixeira fb, souza-filho fj, investigation of the marginal adaptation of root-end filling materials in root-end cavities prepared with ultrasonic tips. int endod j 2009; 36: 491-9. 23. zanini m, sautier jm, berdal a, simon s. biodentine induces immortalized murine pulp cell differentiation into odontoblast like cells and stimulates biominerlaization. int endod j 2012; 38(9): 1-7. 24. grech l, mallia b, camilleri j. characterization of set intermediate restorative material, biodentine, bioaggregate and a prototype calcium silicate cement http://www.ncbi.nlm.nih.gov/pubmed?term=gondim%20e%5bauthor%5d&cauthor=true&cauthor_uid=12823705 http://www.ncbi.nlm.nih.gov/pubmed?term=zaia%20aa%5bauthor%5d&cauthor=true&cauthor_uid=12823705 http://www.ncbi.nlm.nih.gov/pubmed?term=gomes%20bp%5bauthor%5d&cauthor=true&cauthor_uid=12823705 http://www.ncbi.nlm.nih.gov/pubmed?term=ferraz%20cc%5bauthor%5d&cauthor=true&cauthor_uid=12823705 http://www.ncbi.nlm.nih.gov/pubmed?term=teixeira%20fb%5bauthor%5d&cauthor=true&cauthor_uid=12823705 http://www.ncbi.nlm.nih.gov/pubmed?term=teixeira%20fb%5bauthor%5d&cauthor=true&cauthor_uid=12823705 http://www.ncbi.nlm.nih.gov/pubmed?term=souza-filho%20fj%5bauthor%5d&cauthor=true&cauthor_uid=12823705 j bagh college dentistry vol. 26(1), march 2014 an in-vitro scan restorative dentistry 46 for use as root-end filling materials. int endod j 2013; 46(7): 632-41. 25. storm b, eichmiller fc, tordik pa, goodell gg. setting expansion of gray and white mineral trioxide aggregate and portland cement. j endod 2008; 34(1): 80-2. 26. parirokh m, torabinejad m. mineral trioxide aggregate: a comprehensive literature review part 1: chemical – physical ant: bacterial properties. j endod 2010; 36(1): 16-27. 27. torabinejad m, watson tf, pitt ford tr. sealing ability of mineral trioxide aggregate when used as a root end filling material. j endod 1993; 19(12): 591-5. 28. torabinejad m, et al. dye leakage of four root end filling materials: effects of blood contamination. j endod 1994; 20: 159-63. 29. torabinejad m, falah a, kettering jd, pitt ford tr. bacterial leakage of mineral trioxide aggregate as a root end filling material. j endod1995; 21: 109-12. 30. torabinejad m, wilder p, kettering jd, pitt ford tr. comparative investigation of marginal adaptation of mineral trioxide aggregate and other commonly used root-end filling materials. j endod1995; 21: 295-9. 31. inoue s, yoshimura m, tinkle js, marshall fj. a 24week study of the microleakage of four retrofiling materials using a fluid filtration method. j endod 1991; 17: 369-75. 32. banomyong d, palamara jea, messer hh, burrow mf. sealing ability of occlusal resin composite restoration using four restorative procedures. eur j oral sci 2008; 116(6): 571-8. 33. zaia aa, nakagawa r, quadros de, et al. an in vitro evaluation of four materials as barriers to coronal microleakage in root-filled teeth. j endod 2002; 35; 729-34. table 1: duncan's multiple range tests for difference in the gaps between the dentin and the biodentine tm at different time intervals. sub group number mean std. deviation duncan's test a1 7 8.1000 0.888 a a2 7 3.1667 0.7638 b a3 7 1.0000 0.0000 c one-way analysis of variance source df ss ms f test p value factor 2 79.442 39.721 86.77 0.000 error 6 2.747 0.458 total 8 82.189 table 2: duncan’s multiple range tests for difference in the gaps between the dentin and the mta at different time intervals. sub group number mean std. deviation duncan's test b1 7 54.467 4.313 a b2 7 6.000 1.000 b b3 7 3.333 1.528 b one-way analysis of variance source df ss ms f p factor 2 4970.75 2485.37 339.89 0.000 error 6 43.87 7.31 total 8 5014.62 table 3: duncan’s multiple range tests for difference in the gaps between the dentin and the biodentine tm at different time intervals. sub group number mean std. deviation duncan's test c1 7 7.27 0.86 a c2 7 25.000 6.26 a c3 7 64.000 33.81 b one-way analysis of variance source df ss ms f p factor 2 5054 2527 6.41 0.032 error 6 2366 394 total 8 7420 http://www.researchgate.net/researcher/28648225_buffy_storm/ http://www.researchgate.net/researcher/13045870_frederick_c_eichmiller/ http://www.researchgate.net/researcher/39776434_patricia_a_tordik/ http://www.jendodon.com/article/s0099-2399(06)81004-6/abstract http://www.jendodon.com/article/s0099-2399(06)81004-6/abstract http://www.jendodon.com/article/s0099-2399(06)81987-4/abstract http://www.jendodon.com/article/s0099-2399(06)81987-4/abstract http://www.jendodon.com/article/s0099-2399(06)81987-4/abstract http://www.jendodon.com/article/s0099-2399(06)81987-4/abstract http://www.ingentaconnect.com/content/mksg/eos;jsessionid=44s89dtd822ai.alexandra http://www.ingentaconnect.com/content/mksg/eos;jsessionid=44s89dtd822ai.alexandra j bagh college dentistry vol. 26(1), march 2014 an in-vitro scan restorative dentistry 47 28days storage 14days storage 7days storage group material sub-group (a3 ) sub-group (a2 ) sub-group (a1 ) group -a biodentinetm sub-group (b3 ) sub-group (b2 ) sub-group (b1 ) group b mta sub-group (c3 ) sub-group (c2) sub-group (c1 ) group c gic fig. 1: sem images at magnification (1000-1200) x for the interspaces gap between tested materials and dentine table 4: duncan's multiple range tests for difference in the gaps between the biodentine tm and mta and glass ionomer cement at 7 days. material number mean std. deviation duncan's test biodentine tm 7 8.1000 0.889 a mta 7 54.467 4.313 b glass ionomer 7 7.267 0.862 a one-way analysis of variance source df ss ms f p factor 2 4378.40 2189.20 326.15 0.000 error 6 40.27 6.71 total 8 4418.68 j bagh college dentistry vol. 26(1), march 2014 an in-vitro scan restorative dentistry 48 table 5: duncan's multiple range tests for difference in the gaps between the biodentine tm and mta and glass ionomer cement at 14 days. material number mean std. deviation duncan's test biodentine tm 7 3.167 0.764 a mta 7 6.000 1.000 a glass ionomer 7 25.000 6.264 b one-way analysis of variance source df ss ms f p factor 2 845.7 422.9 31.07 0.001 error 6 81.6 13.6 total 8 927.4 table 6: duncan's multiple range tests for difference in the interface gap between the biodentine tm and mta and glass ionomer cement at 28days material number mean std. deviation duncan's test biodentine tm 7 1.00 0.00 a mta 7 3.33 1.53 a glass ionomer cement 7 64.00 33.81 b one-way analysis of variance source df ss ms f p factor 2 7655 3827 10.03 0.012 error 6 2291 382 total 8 9946 table 7: for all sub group number mean std. deviation duncan's test a1 7 8.1000 0.888 a a2 7 3.1667 0.7638 a a3 7 1.0000 0.0000 a b1 7 54.467 4.313 c b2 7 6.000 1.000 a b3 7 3.333 1.528 a c1 7 7.27 0.86 a c2 7 25.000 6.26 b c3 7 64.000 33.81 c one-way analysis of variance source df ss ms f p factor 8 13693 1712 12.77 0.000 error 18 2413 134 total 26 16106 1 10 100 7 days 14 days 28 daysg a p i n m ic ro m e te r time biodentine tm mta gic figure 2: gap distance with time storage for biodentine tm, mta and gic. zainab final.doc j bagh college dentistry vol. 26(2), june 2014 the effect of plasma restorative dentistry 44 the effect of plasma treatment on shear bond strength of soft denture liner with two different types of denture base material (heat cure and light cure) zainab s. abdullah, b.d.s., m.sc. (1) wasmaa s. mahmood, b.d.s., m.sc. (1) rafah a. ibrahem, b.d.s., m.sc. (1) abstract background: in this study we evaluate the effect of plasma treatment (oxygen and argon) gas in two different exposure times on the surface of heat cure and light cure acrylic resin. materials and method: 100 specimens of heat cure and light cure acrylic resin were fabricated. the measurements of the samples were (75mm, 25mm and 4.5mm) length, width and depth respectively with stopper of 3mm depth. two types of gas used oxygen and argon in (5,10) min by using (dc-glow discharge plasma device) then we apply cold cure soft lining material, with the help of instron machine we test the shear stress value. results: a highly significant effect after argon and oxygen gases treatment in both 5 and 10 min exposure times on shear bond strength to soft liner in heat cure denture base material. conclusion: in this study we found that the exposure of heat cure acrylic resin to plasma gases (argon and oxygen) increase the shear bond strength (sbs) values significantly. key words: heat cure and light cure acrylic resin, plasma treatment, shear bond strength. (j bagh coll dentistry 2014; 26(2): 44-49). introduction the most commonly identified problem with denture base incorporating a resilient liner is the failure of the bond between acrylic resin and resilient liner material (1), the most common reason for failure of soft lined denture is the basic structural difference of the two materials (2), several studies have been conducted to improve the bond between the two materials, one of them used different chemical solvents to improve the shear bond strength between different types of denture base materials (3). other study to increase the bond between the two materials used sandblasting with different size of aluminum oxide particles, also by chemical etching (2). all these previous methods have shown to be effective and safe in roughening the surface of materials which subsequently makes the materials more bondable. plasma is the fourth category of matter that's actually the most unusual and the most abundant. plasma has been used for a long time for sterilization of medical equipment. the promise of plasma as a dental preparation will decrease tissue damage and will better prepare the dental surface for composite adhesion (4). plasma could be a new painless way to prepare cavities for filling with improved longetivity (5), the plasma is also capable of bacteria inactivation which makes it an attractive tool for the treatment of dental caries and composite restoration (6). (1) lecturer, department of prosthodontics, college of dentistry, university of baghdad. in recent years the plasma arc light have been introduced in dentistry to reduce curing time of light cure composite like for orthodontists to bond brackets, it could be also beneficial in killing the most bacteria present in mouth like s. mutans (7), also studies showed the changes of surface properties of tooth substance using plasma. yavrich et al (8) which studied the effect of plasma treatment on the shear bond strength between fiber reinforced composite posts and resin composite for core build up and appeared that plasma increase the tensile shear bond strength between them; surface modification by plasma treatment might enable interesting options in dental procedure for better interactions between materials (9). several studies conducted about the use of plasma with acrylic denture base materials (10), so far no studies undertake the correlation between plasma and shear strength in acrylic denture base with soft liner, so the present study focused to use two types of denture base material(heat and light) and two exposure times (5,10) min. with argon and oxygen gases. materials and methods this study used two different types of denture base materials; heat cure acrylic resin (triplex type, germany) and light cure acrylic resin, one hundred specimens were prepared for shear bond strength test. these specimens were divided into two groups each group subdivided into five subgroups each subgroup consisted of ten specimens (n=10) (control group, 5 min. argon j bagh college dentistry vol. 26(2), june 2014 the effect of plasma restorative dentistry 45 gas treated group,10 min. argon gas treated group , 5 min. oxygen gas treated group and 10 min. oxygen treated group). 1. preparation of the specimen for both types of denture base materials metal molds were used with the following dimensions as showed in figure (1): (75mm, 25mm, 4.5mm) length, width and depth respectively with stopper of depth about 3mm (11,12). the thickness of the handle of specimen is 5mm, this is important to have good clamping of the specimen by instron machine and the force was directed parallel to each other. a. heat cure acrylic resin specimens were prepared by coating the metal specimen with separating medium and allow to dry, invested in the lower portion of denture flask that was filled with dental stone (type 3, model-elite model thixotropic / zermack italy),the stone was mixed according to manufacture instruction, p/l ratio 100g/30ml, after setting of stone both metal pattern and stone were coated with separating medium (cold mould seal), then the upper half of flask was positioned properly and filled with stone mixture. the flask was well covered and left for 1 hour then the flask was opened and the standard specimens were removed. heat cured resin was mixed according to manufactures instructions, p/l ratio used was 2.3g/1ml, the mixing was done in clean and dry vessel. the acrylic was packed in the dough stage in the mould, the upper half of flask was positioned in its place. polymerization was carried out according to manufactures instructions by placing the clamped flask in cold water, heat them up to 100 oc and let them to boil for 45 minutes, after curing the clamp and flask were allowed to cool slowly for 30 min. at room temperature. the acrylic specimens were delivered, finished and polished to put the soft liner material. figure 1: a metal mold for shear bond strength test b-light cure acrylic resin groups: as in heat cure acrylic resin denture base material fifty light cured specimens(10 specimens for each group) were made by taking light cure sheet (vertex lc trayplates pink, holland) out of its cover proof, packed and positioned on the mold, the material was adapted in the mold using finger pressure, excess material was removed by cutting using sharp wax knife, curing was done with the light curing unit (vertex eco light box, holland) ( figure 2) for 10 min. then the mold was inverted and exposed to light for additional 10 min. figure 2: vertex eco light box all the specimens (heat and light) were conditioned with distilled water at 37 oc for 48hours before measuring according to ada specification no.12. 2-plasma treatment of the specimens all the specimens were cleaned for 5 min. using ultrasonic cleaning device then, plasma treatment was done by using a device called dcglow discharge plasma device (home made) (figure 3), the applied voltage was 650v with direct current density of (o.o3 ma/cm2), for the two gases used in this study weather argon or oxygen, the same condition conducted for the two types of denture base materials (heat and light). figure 3: dc-glow discharge plasma device 75 mm 25 mm 4.5 mm j bagh college dentistry vol. 26(2), june 2014 the effect of plasma restorative dentistry 46 the samples were placed on cathode surface in a distance of 4.5 cm between the electrodes. the plasma chamber evacuated before the introduction of the gas to performed the exposure of the surface of the sample to the gas to remove the contaminated layer. after completion of the exposure the samples were covered with cling film before testing. the prepared space between the pair of the specimen was filled with soft lining material according to manufacture procedure (cold-curing silicone based relining material permanently soft (promedica / germany). the material was supplied as (base/catalyst) system, the surface of samples were coated with adhesive material, left for one minute then equal part of base and catalyst were extruded by the gun and mixed, after mixing it is placed under pressure, after complete setting the excess material was removed by sharp knife. each specimen was tested using universal instron testing machine with suitable grips for the test specimen. the specimens were subjected to 500n load. cell capacity of cross speed of 0.5mm/1min. until failure occurred was used (11). the value of shear bond strength was calculated for each specimen according to the formula: bond strength (n/mm2) = f/a= maximum load/cross sectional area (astm specification d638m 1986). results descriptive statistics of the shear bond strength (sbs) in (n/mm2) of studied groups showed the highest mean value of sbs in heat cure acrylic resin after 5 min argon gas exposure while, the lowest mean value of sbs also after 5 min argon exposure in light cure acrylic resin (tables 1and 2). table 1: descriptive statistics of the shear bond strength (n/mm2) of light and heat cure acrylic resin to soft liner among the control and argon plasma treated groups (5min. and 10min.) after 10 min exposure after 5 min exposure heat cure control after 10 min exposure after 5 min exposure light cure control 42.47 48.04 28.22 21.08 18.42 20.7 mean 2.683 2.857 1.159 1.881 2.125 2.924 sd 0.849 0.904 0.366 0.595 0.672 0.925 se 38.6 42.8 26.8 18.4 14.6 16.8 min 45.4 51.2 30.5 24.2 22 24.8 max table 2: descriptive statistics of the shear bond strength (n/mm2) of light and heat cure acrylic resin to soft liner among the control and oxygen plasma treated groups (5min. and 10min.) after 10 min exposure after 5 min exposure heat cure control after 10 min exposure after 5 min exposure light cure control 46.94 47.46 28.22 21.06 20.75 20.7 mean 3.571 3.575 1.159 2.172 2.673 2.924 sd 1.130 1.131 0.366 0.687 0.846 0.925 se 38.9 38.6 26.8 18 16.4 16.8 min 50.5 50.8 30.5 24 24.8 24.8 max analysis of variance (anova) test showed a significant difference between groups of light cure acrylic resin after argon gas exposure while, a highly significant difference among groups of heat cure acrylic resin after argon and oxygen gas exposure. a non-significant difference between light cure groups after oxygen gas exposure was shown (table 3). in table (4) the least significant difference lsd test showed a significant difference between control group and 5 min argon exposure group and also between 5 min and 10 min argon exposure groups in light cure studied groups. a highly significant difference between the studied groups of heat cure in two different exposure times and in two gases was shown. the independent sample t-test showed a significant difference between the two gases after 5 min exposure in light cure groups and between the two gases after 10 min exposure in heat cure groups. a non-significant difference between the two gases after 10 min exposure in light cure groups and between the two gases after 5 min exposure in heat cure groups was shown and highly significant difference between light cure control group and heat cure control group also found (table 5). j bagh college dentistry vol. 26(2), june 2014 the effect of plasma restorative dentistry 47 table 3: anova test of shear bond strength among studied groups sig df p-value f-test studied groups of oxygen gas exposure sig df p-value ftest studied groups of argon gas exposure ns 2 between groups 0.909 0.095 light cure (control, 5 min, 10 min) s 2 between groups 0.036 3.737 light cure (control, 5 min, 10 min) 27 within groups 27 within groups 29 total 29 total hs 2 between groups p<0.01 134.08 heat cure (control, 5 min, 10 min.) hs 2 between groups p<0.01 187.5 heat cure (control, 5 min, 10 min.) 27 within groups 27 within groups 29 total 29 total table 4: lsd test between control groups and the two different exposure times (5 min., 10 min.) of the two different gases (argon and oxygen) sig p-value mean difference oxygen gas exposure studied groups sig pvalue mean difference argon gas exposure studied groups hs p<0.01 -19.24 control&5min heat cure s 0.039 2.28 control& 5min light cure hs p<0.01 -18.72 control&10min s 0.017 -2.28 5min&10min hs p<0.01 -19.82 control&5min heat cure hs p<0.01 -14.25 control&10min hs p<0.01 5.57 5min&10min table 5: t-test between studied groups between light cure control and heat cure control argon and oxygen 10min exposure in heat cure argon and oxygen 5 min exposure in heat cure argon and oxygen 10min exposure in light cure argon and oxygen 5 min exposure in light cure 7.911 4.197 0 0.027 3.231 t-test p<0.01 0.002 p>0.01 0.979 0.01 p-value hs s ns ns s sig *p<0.05 significant, *p<0.01 high significant, **p>0.05 non significant discussion soft liner has been a good help for the dentist because of their act as shock absorber, for patient comfort and for treatment of atrophic ridge and bone undercut all these are positive values but the disadvantages also exist because of the lack of durable bond to the denture (13). many researchers suggest roughening the surface to increase the surface area, a study conducted by craige (14) reported that adhesive effect is obtained with rough surface were approximately double those of smooth surface. so in this study we tried to improve the bond between soft lining material and two types of acrylic denture base material by using argon and oxygen plasma with two different times to measure the shear stress value. as we discuss the results we begin firstly by the effect of plasma (argon and oxygen gases)on light cure group which showed a significant differences in sbs values after argon gas exposure (20.7, 18.42, 21.08) mean values in( control, 5 min exposure,10 min exposure) respectively ,these values might be statistically significant but clinically not significant. hence these values were so close (table 1). a non significant effect of oxygen gas treatment between the groups of light cure denture base material as showed in table 3.secondly, we discuss the effect of these two gases on heat cure group, the results showed us a highly significant differences in sbs values after argon gas treatment between the three groups the mean values (28.22, 48.04, 42.47) in ( control, 5 min, 10 min ) groups respectively .for argon gas we relate its effect of increasing the shear values to physical removal of material when exposed to it which increase surface roughness caused by bombardment of high molecular weight gas particles that improve the micromechanical interlocking between the soft lining material and heat cure denture base material this come in agreement with gossen et al (15) and with sladek (16). j bagh college dentistry vol. 26(2), june 2014 the effect of plasma restorative dentistry 48 on the other hand the results appeared that the 5 min argon gas exposure is the best time for treatment in which this gas is more effective in 5 min, but 10 min exposure was used just to see the effect of lengthening of time (17). after exposing heat cure samples to oxygen gas the results showed a highly significant differences in sbs values as showed in table 2. the effect of oxygen explained by the etching process by removing from surface material without effecting the bulk, this roughening will enhance the bonding between soft liner and heat cure denture base material (18,19). table 5 showed a significant difference in sbs values between the two gases in 5 min time exposure in light cure group which considered statistically different but with no clinical effect as the mean values were so close (18.42, 20.75). a significant difference also between the two gases in 10 min time exposure in heat cure group, which might be due to superior effect of oxygen by chemical oxidation reaction which generate a new chemical functional group on the oxygen plasma treated surface such as hydroxyl group which enhance the penetration of soft liner into the irregularities which enhance the adhesion between the two materials (20,21). finally we discuss the highly significant difference between the two control groups (heat and light) which attributed to the difference in material structure and processing method of denture base, also due to the presence of large number of porosities in light cure which could not be kept under pressure so common defect and internal voids could be found (22,23); this come in agreement with smith and chaitanya (24). in this study we came up with the conclusion that plasma surface 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bagh college dentistry vol. 26(2), june 2014 the effect of plasma restorative dentistry 49 strength to heat cured acrylic denture base material. j bagh coll dentistry 2013; 25(si1): 6-11. 22. hachim tm. evaluation of shear bond strength of silicon-based soft liner to the acrylic resin denture base using different polymerization technique with different storage periods in distilled water. j bagh coll dentistry 2012; 24; 42-6. 23. gurbuz o, unalan f, dikbas i. comparison of the transverse strength of six acrylic denture resin. ohdmbsc 2010; 9: 21-4. 24. smith t, chaitanya babu n. plasma in dentistry: an update. indian j dental advancements 2010; 2: 21014. j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 1 prevalence of viral co-infection among covid-19 cases in association with disease severity and oral hygiene zeina sami adham )1(, batool hassan al-ghurabi )2( https://doi.org/10.26477/jbcd.v33i3.2947 abstract background: in december 2019, an episode of covid-19 caused by severe acute respiratory syndrome coronavirus 2 (sarscov2) was reported in wuhan, china and has spread around the world, increasing the number of contagions. cytomegalovirus (cmv) and epstein-barr virus (ebv) are common herpesviruses that can cause persistent latent infections and affect the developing immune system. the study was conducted to explore the prevalence and reactivation of cmv and ebv antibodies in covid-19 patients group in comparison to healthy group and to investigate the association between the presence of these viruses with each of severity of disease and oral hygiene. materials and methods: eighty five subjects were participated in this case control study (50 patients with covid-19 and 35 healthy controls), their age ranged from 18 to 77 years. oral health status was established by oral hygiene index. serum obtained from patients and controls was analyzed using elisa to assess levels of anticmv and antiebv antibodies. results: the study revealed that the mean of anti-ebv igg in patients was more significantly elevated (p<0.01) than that in controls. otherwise, there was no significant difference (p>0.05) in levels of antiebv igm, anti cmv igg and igm between two groups (p>0.05). in addition, there were no significant differences between patients and controls (p>0.05) in the number and percentage of anti-ebv and anti-cmv antibodies. interestingly, there was a significant increase in the level of anti-cmv igm in severe cases as compared to mild cases (p<0.01). furthermore, these results revealed that there were no significant differences (p>0.05) in levels of anti-viral antibodies in patients with good oral hygiene compared to patients with poor oral hygiene. conclusions: higher frequency of anti-ebv igg among patients indicates that latent infection is more common in covid-19 patients. while an increased percentage of anti-cmv igm indicated reactivation of latent infection and is related to disease severity suggesting that covid-19 can cause cellular immune impairment. key words: covid-19, herpes virus, cytomegalovirus, epstein-barr virus. (received: 11/7/2021, accepted: 12/8/2021) introduction coronaviruses are zoonotic viruses as they are transmitted between animals and humans. coronavirus is a single rna virus that has the ability to mutate and recombine rapidly. it is the causative agent of respiratory and intestinal infections in humans and animals (1). a new coronavirus called (sars-cov-2) severe acute respiratory syndrome coronavirus 2 appears in wuhan / china, causing an outbreak of abnormal viral pneumonia. this new coronavirus illness, commonly known as coronavirus disease 2019 (covid-19), is exceedingly transmitted, and has spread fast all over the world (2, 3). the significant prevalence of co-infections among sars-cov-2 patients is supported by mounting evidence, and their potential to worsen the clinical outcome of covid-19. dysfunction of immune function is considered as one of the reasons for high mortality in covid-19, and reactivation of herpes viruses in patients is thought to be related to immune dysfunction (4). (1) master student, ministry of health/ national center for drug control and research, baghdad, iraq. (2) professor, department of basic science, college of dentistry, university of baghdad, iraq. corresponding author's e-mail: zeina.adham@yahoo.com cmv is a herpes virus that can remain dormant for the rest of one's life. the viral replication cycle will be resumed if the patient's immune system is compromised (5, 6). cmv is a common pathogen of global clinical relevance, with worldwide seroprevalence ranging from 56% to 94% (7), can infect various human cells (8). ebv is a ubiquitous herpes virus with which ~ 95% of healthy adults are infected (9). ebv is transmitted through saliva and infects pharyngeal epithelial cells. when released from the epithelial cells, ebv infects b cells in the underlying tissue, where it might grow or go into a dormant condition, depending on the b cell environment and the state of the host immune response (10). ebv viremia can also be considered as one of the measures of functional exhaustion of cellular immunity. infection with the sars-cov-2 virus can result in antiviral cells becoming functionally exhausted, as well as a cytopathic effect (11). in severe patients, reactivation of viruses such as herpes simplex, cmv, and ebv occurs, and functional exhaustion of cytotoxic lymphocytes is suggested as the cause. covid-19 can cause cellular immune dysfunction so it can induce reactivation of the latent viruses (12). recently, the pathological report of covid-19 dead patient suggested that there was over-activation of t cells, which to some extent led to severe immune https://doi.org/10.26477/jbcd.v33i3.2947 https://www.frontiersin.org/articles/10.3389/fmicb.2020.01511/full#b36 j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 2 injury in covid-19 patients (13). furthermore, covid-19 and ebv-induced infectious mononucleosis have symptoms such as fever, tiredness, myalgia, anorexia, and sore throat, implying a possible link. (14, 15). improving oral hygiene during a covid-19 infection reduces the microbial load in the mouth and the risk of microbial super-infection (16). it may be useful in reducing viral load in asymptomatic covid-19 patients while also providing health professionals with a protective oropharyngeal hygiene strategy (17). the point of this research was to explore the prevalence and reactivation of herpes viruses (cmv and ebv) in covid-19 patients group in comparison to healthy group and to investigate the association between the presence of cmv and ebv with oral hygiene and severity of illness. materials and methods subject study groups: a total of 50 patients with covid-19 (29 males and 21 females) were enrolled in this study, their age ranged (1877) years. they were admitted to baghdad teaching hospital/ medical city from november 2020 to january 2021. all patients were diagnosed with sars-cov-2 infection, according to the world health organization criteria (18). real-time reverse transcriptase-polymerase chain reaction (rtpcr) assay was used to identify sarscov-2 infection. the clinical classification of patients was categorized by disease severity into mild, moderate and severe, according to sign and symptoms by clinical management guidelines outlined in the diagnosis and treatment protocol for covid-19. control group consisted of 35 individuals (16 males and 19 females), their ages and sexes were matched to patients…, their ages ranged between (18-73) years. ethical clearance from ethical committee, college of dentistry/ university of baghdad inclusion criteria: the patients enrolled in this study and considered eligible must have met the following criteria; signs and symptoms of covid-19 infection (fever, generalized malaise, cough and shortness of breath) and rt-pcr for covid-19. exclusion criteria: pediatric and pregnant patients, patients with chronic viral infection and systemic diseases, allergic rhinitis and chronic sinusitis, and patients who could not give informed consent were excluded from this study. oral examination: oral examination was performed by the specialist dentist. the average individual or group debris and calculus scores are combined to obtain oral hygiene index, according to (19). oral hygiene index = debris index + calculus index sample collection: three milliliter of venous blood was drawn from all subjects. blood was transferred to sterile plain tube, and serum was separated by centrifugation at 3000 rpm for 10 min, then divided into small aliquots and kept at -20ºc until used for analysis. measuring of anti-cmv and anti-ebv antibodies the level of anti-cmv and anti-ebv antibodies was determined by elisa and performed as recommended in leaflet with kit (demeditec/ germany). statistical analysis: as shown by histograms and smemirnove-kolmogorove test, the data was non-parametric and described by median and the non-parametric tests of significance were advocated for use. p value less than the 0.05 was considered statistically significant. results the demographic and clinical features of the 85 subjects enrolled in this study are summarized in table (1). the present study showed that there were no significant differences in serum level of anti-cmv igg and igm antibodies between patients group and healthy controls group (p>0.05), table (2). the median serum level of cmv igg in patient group was (2.19 u/ml) and for control group was (2.41 u/ml). the mean serum level of cmv igm in patients group was (0.82±0.09 u/ml), and (0.71±0.05 u/ml) for healthy control. j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 3 table 1: demographic and clinical features in study and control groups. demographic and clinical features study groups p-value patients group n=50 control group n=35 age (years) mean ± sd 44.26±16.57 40.08±12.64 p>0.05 gender male 29 (58%) 19(54%) p>0.05 female 21 (42%) 16(46%) disease severity mild 24 (48%) moderate 16 (32%) severe 10 (20%) oral hygiene good 30 (60%) 29 (83%) poor 20 (40%) 6 (17%) table 2: case control difference in serum levels of anti-cmv igg (u/ml) and anti-igm(u/ml). anti-cmv antibodies study groups p-value patients group n=50 control group n=35 serum cmv igg 0.610ns min 1.60 0.96 max 3.48 3.49 median 2.19 2.41 mean rank 41.84 44.66 serum cmv igm 0.161ns min 0.08 0.3079 max 2.89 1.7892 mean 0.82 0.71 se 0.09 0.05 the mean serum level of anti-ebv igg in patients group (1.53±0.08 u/ml) was significantly elevated (p<0.01) as compared with healthy controls (0.66±0.08 u/ml). on the other hand, there was no statistically significant difference (p>0.05) in median serum level of anti-ebv igm between patients group (0.24 u/ml) and controls group (0.23 u/ml), table (3). table-3: case control difference in serum levels of anti-ebv igg (u/ml) and anti-ebv igm (u/ml). anti-ebv antibodies study groups p-value patients group n=50 control group n=35 anti-ebv igg <0.0001** min 0.53 0.23 max 2.76 2.15 mean 1.53 0.66 se 0.08 0.08 anti-ebv igm 0.423ns min 0.09 0.08 max 1.36 0.71 median 0.24 0.23 mean rank 44.80 40.43 in addition, there were no significant differences (p>0.05) in the prevalence of anti-cmv igg and igm between patients and controls. 45 (90%) patients were anti-cmv igg positive and 5 (10%) were negative. for controls group it was found that 30 (86%) were positive, while 5 (14%) were negative. besides, the presence of anti-cmv igm in patient group found that 12 (24%) were positive and 38 (76%) were negative, for control group 6 (17%) were positive and 29 (83%) were j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 4 negative. the number and percentage of patients group who had positive result for anti-ebv igg were 44 (88%), while 6 (12%) of patients were negative, and for control group 10 (29%) were positive and 25 (71%) were negative. hence, there were no significant differences between patients and controls (p>0.05). further, prevalence of anti-ebv igm in patients group revealed that only 2 (4%) patients out of 50 were positive and the rest 48 (96%) were negative, while all controls were negative, table (4), figure (1). table-4: prevalence of anti-ebv and anti-cmv antibodies in patients and controls. anti-cmv and ebv antibodies patients group n=50 control group n=35 p-value frequency percentage frequency percentage anti-cmv-igg 0.492 ns positive 45 90% 30 86% negative 5 10% 5 14% anti-cmv-igm 0.591ns positive 12 24% 6 17% negativ 38 76% 29 83% anti-ebv-igg <0.000** positive 44 88% 10 29% negative 6 12% 25 71% anti-ebv-igm 0.509ns positive 2 4% 0 negative 48 96% 35 100% figur-1: prevalence of anti-ebv and anti-cmv antibodies in patients and controls. the results of serum anti-cmv and anti-ebv antibodies (igg and igm) levels in covid-19 patients groups (severe, moderate and mild) were illustrated in table (5). there are non-significant differences (p>0.05) in levels of anti-cmv and anti-ebv antibodies (igg and igm) among three groups of patients. the level of anti-cmv igg was in severe cases (2.48 u/ml), in moderate (2.40 u/ml) and in mild cases (2.11 u/ml). for serum anti-cmv igm, the level in patients with severe, moderate and mild cases was (1.09±0.53 u/ml, 0.79±0.25 u/ml and 0.66±0.30 u/ml), respectively, and there was a significant increase in anti-cmv igm level in severe cases as compared to mild cases, (p<0.01). regarding anti-ebv igg, the mean level of anti-ebv igg in severe, moderate and mild group was (1.44±0.50 u/ml; 1.54±0.64 u/ml and 1.55±0.55 u/ml) respectively. on the other hand, the median level of anti-ebv igm was (0.82 u/ml; 0.32 u/ml and 2.47 u/ml) respectively. table 5: comparison the levels of serum anti-cmv and anti-ebv antibodies (igg and igm) in patients group according to severity disease. serum antibodies (u/ml) patients group severe n=10 moderate n=16 mild n=24 p-value anticmv igg 0.236ns median 2.48 ans 2.40bns 2.11cns mean rank 11.1 15.0 22.5 anticmv igm 0.078ns mean 1.09 ans 0.79 bns 0.66 c* se 0.53 0.25 0.30 antiebv igg 0.874ns mean 1.44ans 1.54bns 1.55cns se 0.50 0.64 0.55 antiebv igm 0.050ns median 0.28 ans 0.32 bns 2.47 cns mean rank 13.70 13.83 28.5 patients-positive patienrs-negative control-positive control-negative 88% 12% 29% 71% 4% 96% 0% 100% 90% 10% 86% 14% 24% 76% 17% 83% ebv-igg ebv-igm cmv-igg cmv-igm j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 5 a: comparison between severe and moderate groups; b: comparison between moderate and mild groups; c: comparison between severe and mild groups ; ns: not significant; *: significant furthermore, the present results revealed that there were no significant differences (p>0.05) in serum levels of anti-cmv and anti-ebv antibodies in patients with good oral hygiene compared to patients with poor oral hygiene. the mean levels of serum anticmv igm and anti-ebv igg in patients with good oral hygiene were (0.89±0.68u/ml and 1.61±0.61u/ml), and for patients with poor oral hygiene were (0.72±0.45u/ml and 1.39±0.48u/ml). the median level of serum anti-cmv igg and anti-ebv igm in patients with good oral hygiene was (2.50u/ml and 0.24u/ml) as compared to that in patients with poor oral hygiene (2.10u/ml and 0.24u/ml), as shown in tables (6). table 6: comparison the levels of serum anti-cmv and anti-ebv antibodies (igg and igm) in patients group according to oral hygiene. serum antibodies (u/ml) good oral hygiene n=30 poor oral hygiene n=20 anticmv igg min 1.68 1.60 max 3.48 3.09 median 2.50 2.10 mean rank 29.93 18.85 p-value 0.060 ns anticmv igm min 0.08 0.25 max 2.89 1.97 mean 0.89 0.72 sd 0.68 0.45 p-value 0.172ns antiebv igg min 0.53 0.68 max 2.76 2.24 mean 1.61 1.39 sd 0.61 0.48 p-value 0.090ns antiebv igm min 0.09 0.1378 max 0.65 1.365 median 0.24 0.24 mean rank 24.45 27.08 p-value 0.541ns discussion sars-cov-2 infection research is currently the top priority for science communities all around the world, which is unsurprising. to our knowledge, this is the first study in iraq to look into the impact of sars-cov-2 infection on cmv and ebv reactivation and prevalence in connection to oral health. twenty covid-19 patients had bad oral hygiene, according to the current study, and the severity of covid-19 symptoms was considerably elevated in patients with poor oral hygiene. furthermore, those who practiced good dental hygiene experienced a considerable reduction in the severity of their symptoms. this result was in correlation with the previous findings (20, 21), which indicated that the number of patients with poor oral health was considerably higher than the number of patients with good oral health, implying that mouth health may have a role in covid-19 degeneration, whether owing to viral infection or secondary bacterial infection. co-infection of the sars-cov-2 with other microorganisms is a major feature in covid-19 pathogenesis that can make correct diagnosis, treatment and prognosis difficult, as well as increase fatality rates (22). there were no statistically significant variations in serum levels of anti-cmv antibodies between covid-19 patients and healthy controls in this investigation. however, this study found that cmv reactivation occurred in 24 percent of the individuals. j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 6 because cmv is latent in around 90% of persons, cmv viremia might be considered one of the indicators of cellular immunity's functional depletion. infection with the sars-cov-2 virus can result in antiviral cells becoming functionally exhausted, as well as a cytopathic effect (12). covid-19 also exhibits acquired immunosuppression, such as lymphopenia, and a cytokine storm, with elevated levels of cytokines such as tnf-. tnfcould be a direct relationship between cmv reactivation and tnf-. in addition, sars-cov-2 stimulates macrophages by inducing a vicious cycle of m1 type macrophage polarization, which promotes the reactivation of latent cmv and fuels additional inflammation (23). this finding is in agreement with previous research that found cmv reactivation was frequent more common in covid-19 ards patients, with higher rates (24). moss and colleagues (25) speculated that any link between cmv infection and sars infection's clinical outcome could be represented by the degree of sars-cov-2 viral replication or the quality of the subsequent immune reaction. other studies (26, 27) indicated that cmv specific antibodies were the best predictors of infection risk, and covid-19 patients had higher antibody responses to particular cmv and hsv-1 peptides than those who were not hospitalized. another finding in this study was a substantial rise in anti-cmv igm levels in severe patients compared to mild and moderate illness patients, which was in consistent with another study (28) that found cmv reactivation was linked to the severity of covid-19. if cmv is reactivated in covid-19 patients and co-infects with sars-cov-2, the two viruses could have negative consequences. they' would be predicted to suppress or even kill t cells and natural killer cells stimulate macrophages and neutrophils in a chain reaction that leads to inflammation's point of no return, and then influence endothelial cells and thrombocytes to produce coagulation and thrombus formation—exactly as seen in covid-19 patients (29). with regard to anti-ebv antibodies, this study showed significant elevation in the levels of anti-ebv igg in covid-19 patients as compared to healthy individual, while there were no significant differences in levels of anti-ebv igm between patients and controls. this result is in agreement with previous studies (28, 15) that indicated the presence of ebv co-infection with sarscov-2 in covid-19 patients. likewise, (30) ….. reported that ebv infection is prevalent in humans and after primary infection the virus can persist in the body in a latent form. the higher rate of ebv co-infection (antiebv igg) in the sars-cov-2 samples, as compared to other respiratory viruses, could be reflective of the high ebv instances in the general population or a result of lytic reactivation of the virus as observed under conditions of immunosuppression (30). sars-cov-2-positive individuals, on the other hand, exhibited decreased rates of coinfections for all viral targets, including ebv, according to another study (31). furthermore, no significant variations in anti-ebv antibody levels were seen across three groups of patients in this investigation. this study, however, contradicts chen and colleagues' findings, who found that median ebv levels in patients with severe covid19 disease were considerably greater than in patients with mild covid-19 disease (28). furthermore, mo et al. (25) discovered that ebv reactivation is linked to the severity of covid-19. anti-ebv and anti-cmv antibody levels were not significantly different between covid-19 patients with good oral hygiene and patients with poor oral hygiene. this could be due to the small number of patients studied in this study, as well as the fact that there were fewer patients following subdivision, resulting in the lack of such an association. individuals with poor oral hygiene are more likely to develop periodontitis, as there is a strong link between poor oral hygiene and the accumulation of dental plaque, which is a risk factor for periodontitis (32). however, no available studies found to compare this result with it. the limitation in this work is that the sample size in this study was relatively small, as well as cmv and ebv dna did not test. these findings showed that higher frequency of anti-ebv igg among patients indicates that latent infection is more common in covid-19 patients. an increased percentage of anti-cmv igm indicated reactivation of latent infection and is related to disease severity suggesting that covid-19 can cause cellular immune impairment. j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 7 conclusion these findings showed that higher frequency of anti-ebv igg among patients indicates that latent infection is more common in covid-19 patients. further an increased percentage of anti-cmv igm indicated reactivation of latent infection and is related to disease severity suggesting that covid19 can cause cellular immune impairment. conflicts of interest the authors have no conflicts of interest to declare that are relevant to the content of this article refernces 1. cheng vcc, lau skp, woo pcy, et al. severe acute respiratory syndrome coronavirus as an agent of emerging and reemerging infection. clin microbiol rev.2007; 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"the ancient and the new": is there an interaction between cytomegalovirus and sarscov-2 infection?. immunity & ageing: i & a. 2020;17:14. 26. shrock e, fujimura e, kula t, et al. viral epitope profiling of covid-19 patients reveals cross-reactivity and correlates of severity. science (new york, n.y.). 2020; 370(6520), eabd4250. 27. willette aa, willette sa, wang q, et al. antibody response to infectious diseases and other factors accurately predict covid-19 infection and severity risk 10-14 years later: a retrospective uk biobank cohort study. med rxiv: the preprint server for health sciences, 2020.06.09.20127092. 28. chen t, song j, liu h, et al. positive epsteinbarr virus detection in coronavirus disease 2019 (covid-19) patients. scientific reports. 2020; 11(1):10902. j bagh college dentistry vol. 33(3), september 2021 prevalence of viral 8 articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. 29. söderberg-nauclér c. does reactivation of cytomegalovirus contribute to severe covid-19 disease? immunity & ageing. 2021; 18(1):12. 30. xu z, shi l, wang y, et al. pathological findings of covid-19 associated with acute respiratory distress syndrome. the lancet. respiratory medicine. 2020; 8(4): 420-422. 31. singh v, upadhyay p, reddy j, et al. sarscov-2 respiratory co-infections: incidence of viral and bacterial co-pathogens. international int j infect dis. 2021; 105:617–620. 32. lertpimonchai a, rattanasiri s, arj-ong vallibhakara s, attia j, thakkinstian a. the association between oral hygiene and periodontitis: a systematic review and metaanalysis. inter dent j. 2017; 67(6):332–343. المستخلص المت زمةة التسفسةةي ٢-فيةة وك ك نونةةو يسةةهه الةة و ١٩-ك فيةة مةة عةة االبةة ، تةة ٢٠١٩ كةةون ا الو فةة :الخلفيةة . ي ةة الفيةة وك الم ةةخ ، الصةةي وانت ةة فةة نميةةا عنحةةو ال ةةول ، ممةةو زا مةة عةة ال ةة و فةة وونةةوا الحةةو ا ال ميمةة مةة في وتةةوه ال ةة بئ ال ةةو التةة يم ةة عا تسةةهس عةة و كومسةة مسةةتم ا وتةة علةة بةةون -وفيةة وك شب ةةتوي للخ يةةو لفي وك الم ةةخ للخ يةةو ةةو ا لةةةانت ةةون وشعةةو ا تس ةةيا النسةةو الم لل ةةع عةة ال ناتةة نةة ن يةة ع الج ةةوز المسةةوع . وللتحقةةم مةة االنتهةةوو بةةي ونةة نةة بوالصةةحو مقوننةة ١٩-ك فيةة الم ضةة المصةةوبي فةة بةةون -شب ةةتوي وفيةة وك الم ونظوف الف . ش االفي وتوه ما كل م و مصةةوبًو بةةة المةة ا والقةة ع ال مةةل : و مممسةة ا م ي ةةً و ممسةة ١٩فيةة كشةةونف فةة نةة ال ناتةة ممسةة و مةةوني شخصةةً تةة تةةس . تةة تح يةة حولةة صةةح الفةة مةة مةة م شةة صةةح الفةة . و ٧٧-١٨و ةة ا مةة االصةةحو ر ، تتةة اوم ععمةةونن بةةي قيةةي مسةةت يوه لت الم ضةة واالصةةحو الةة تةة الحصةة عليةة علةة عيسةةوه المصةةل عنةة ا الفحةةم المسةةوع المةة تها بةةوالن ي .بون -في وك شب توي والنسو الم و ا ل للخ يو ولفي وك الم خ النسو الم و ا لة بون فة الم ضة كةوا م تف ًةو ب ة ل -ر الم و لفي وك شب توي g -ك ف ال نات الحولي عا مت تا مالجل بي لي المسوع الستو ج: ر فة مسةت يوه الجل بية لي p>0.05و يًو مر مقونن ً بوالصحو . بخ ف ذلك ، ل ي نسوف ف ع ذاه الل شحصةp<0.01ملح ظ م الم ةو للفية وك الم ةخ m-و الجل بية لي المسةوع g –بةون ، والجل بية لي المسةوع -الم ةو لفية وك شب ةتوي m-المسوع حو فة عة ر بي الم ض واالصp>0.05للخ يو بي المجم عتي . بوإلضوف شل ذلك ، ل ت نسوف ف وع ذاه الل شحصو ي م والجل بية لي g -بون والنسو الم و ا للفية وك الم ةخ للخ يةو مالجل بية لي المسةوع -ونسه االنسو الم و ا لفي وك شب توي الم ةخ للخ يةو فة الحةواله m-ر. وم المثي ل نتمو ، عن كون نسوف زيو ا كهي ا ف مست الجل بية لي المسةوع m -المسوع ر p>0.05ر . ع وا عل ذلك ، عظ ه ن الستو ج ع ون ف وع ذاه الل شحصو ي p<0.01مقونن بولحواله الخفيف م ال ي ا ر ف مست يوه النسو الم و ا للفي وتوه ف الم ض ال ي يتمت ا بسظوف فم ي ني ا مقونن بولم ض ال ي ي ون ا مة تة نظوف الف . ر شل عا ال ة و g -الت ان ال ول ل نسو الم و ا لفي وك شب توي بون مالجل بي لي المسوع عا عظ ه ن الستو ج االتتستونوه: ال ومس عكث شي ًعو ف الم ض . ف حي عا السسه المئ ي المت اي ا مة النسةو الم ةو ا للفية وك الم ةخ للخ يةو مالجل بية لي يم ة عا ٢٠١٩تس يا ال و ال ومس وت تها ب ا الم ممو ي ي شلة عا مة فية وك ك نونةو ر ي شل شعو اm -المسوع يسهس امت وظيف ف المسوع الخل ي و ي ك االنتهوو السله بي النسو الم و ا للفي وتةوه والههتية الم ةو للمي وبةوه فة الم ض ض ع االتتجوب المسوعي . alaa.doc j bagh college dentistry vol. 27(2), june 2015 effect of the pedodontics, orthodontics and preventive dentistry136 effect of different staining materials on color stability of sapphire brackets bonded with different types of light cure orthodontic adhesives (an in vitro study) alaa faleh albo hassan, b.d.s. (1) nidhal h. ghaib, b.d.s., m.sc. (2) abstract background: the demand for better esthetic during orthodontic treatment has increased nowadays, so orthodontists starting using esthetic arch wires, brackets and ligatures.tooth colored brackets were introduced in different types of materials. sapphire ceramic brackets are one type of esthetic brackets and their color stability remains the main concern for the clinicians and patients at the same time . the present study design to evaluate the effect of three different staining materials (pepsi, black tea and cigarette smoke) on the stainability of sapphire ceramic brackets bonded with three types of light cure orthodontic adhesives which include: resilience, enlight and transbond. materials and methods: the sample consisted of three hundred sixty sapphire brackets. the brackets were divided according to bonding materials into three groups each group consist of one hundred twenty brackets, then each subgroup farther subdivided into four groups according to the material they were immersed (distilled water, black tea, pepsi and cigarette smoke) with thirty brackets each, then each group with ten brackets farther subdivided according to time interval of immersion in each media into three groups one day, seven days and fourteen days at 37°c in the incubator.a uv-visible spectrophotometer (shimadzu, uv -1800) was used to perform a light absorption test. results: anova and lsd post hoc tests were used to identify the significant effects of the staining materials at a significance level p ≤ 0.05.it was found that the immersion time gradually influenced the color stability of the adhesive materials with sapphire brackets with the highest activity observed at fourteen days interval. the brackets bonded with resilience light cure adhesive are the most type affected by staining materials, then followed by the brackets bonded with transbond and finally the brackets bonded with enlight light cure adhesive. for the staining materials it was found that the cigarette smoke is the most powerful staining material, followed by tea and finally pepsi. conclusions: from the above result we can conclude that the type of adhesive must take in consideration when the esthetic brackets have been used. key words: sapphire brackets, color stability, staining materials. (j bagh coll dentistry 2015; 27(2):136-141). introduction in modern society, the esthetic aspect of orthodontic therapy is becoming increasingly important because of the growing number of adult patients. ceramic brackets have been developed to improve esthetics during orthodontic treatment (1,2). all currently available ceramic brackets are composed of aluminum oxide and because of their distinct differences during fabrication, two types of ceramic brackets are available, namely the polycrystalline alumina which are binders to thermally fuse the particles together, and the single crystal alumina or monocrystalline alumina or sapphire brackets which are milled from single crystals of sapphire (monocrystalline) using diamond tools (3-6). color stability is considered an important factor in the success of an esthetic treatment several factors influence the color stability of contemporary light activated materials, such as the photo initiator system, the resin matrix, the light-curing unit used for polymerization, and the irradiation times (7). (1) master student, department of orthodontics, college of dentistry, university of baghdad. (2) professor, department of orthodontics, college of dentistry, university of baghdad. however, the optical properties of dental composite resins change because of polymerization, and the extent of change is influenced by the brand and shade of resin composites and the wavelength of curing lights (8,9). composite resin discoloration is multifactorial, including factors such as intrinsic discoloration and extrinsic staining. cigarette smoke, tea, and pepsi are the most materials used among iraqi people that have a potential staining ability. therefore, it is important to assess the effect of these materials on the sapphire ceramic brackets. materials and method for this study 360 perfect clear sapphire brackets (hubit/korea) for maxillary central incisors on the right side were used, roth type, slot 0.018” x 0.022”. three types of light cure orthodontic adhesive were used in this studyenlight light cure orthodontic adhesive (ormco / italy), transbond tm xt light cure orthodontic adhesive (3m unitek /usa) and resilience® light cure orthodontic adhesive system (orthotechnology/ usa) fig. (1). black j bagh college dentistry vol. 27(2), june 2015 effect of the pedodontics, orthodontics and preventive dentistry137 tea (ahmad tea, england), pepsi (baghdad company, iraq), cigarette (gauloises blondes, european union) and distilled water (control media) used as the staining materials. figure 1: bonding materials used in the present study. sample organization the sample composed of 360 sapphire brackets were used in testing the staining effect of black tea, pepsi and cigarette smoke. the brackets were divided according to bonding materials into three groups each group consist of 120 brackets: 1. brackets bonded with enlight light-cure orthodontic adhesive composite. 2. brackets bonded with transbond tm xt light cure orthodontic adhesive composite. 3. brackets bonded with resilience® light cure orthodontic adhesive composite. then each subgroup farther subdivided into four groups according to the media they were immersed (distilled water as control group, black tea, pepsi and cigarette smoke) with 30 brackets each, then each group (with 10 brackets)farther subdivided according to time interval of immersion in each media into three groups (1day,7days and14days ) bonding procedure a small amount of the adhesive paste was applied onto bracket base , then by using a clamping tweezer the bracket was placed lightly onto glass slide mounted on the table of surveyor (dentaurum, germany) covered by celluloid strip to facilitate detachment of the bracket adhesive complex with a recovery of the set material then a constant load was placed on the bracket for 10 seconds (by fixing the 200 gm load on the upper part of the vertical arm of the surveyor, and fixing the analyzing rod in the lower part of the vertical arm of the surveyor and put it in contact with the bonded bracket), to ensure that each bracket was seated under an equal force and to ensure a uniform thickness of the adhesive. then any excess adhesive material was removed from around the bracket base with a sharp hand scaler without disturbing the seated bracket. after that the bracket adhesive was photopolymerized with a light-curing unit (blue lex ld-109, taiwan); the light guide of curing light unit was directed toward the bracket, the light shined through the bracket for 5 ,10, 20 seconds for transbond tm xt, enlight, resilience® adhesive pastes respectively .the bonded brackets were allowed to bench set for 24 hrs. to ensure complete polymerization of adhesive material, after setting; the celluloid strips were removed and the resultant bracket bonded adhesive were flat surfaces. smoke chamber the smoke chamber was a plastic container allowing cigarette smoke to enter from one end of the chamber , by a rubber tube that fit the cigarette, the rubber tube positioned to provide a uniform distribution of the entering cigarette smoke, and leave from the other end, by a portable suction device (saliva ejector) (hoo3-c, china) fitted that caused a negative pressure to aspirate the smoke released by the cigarette, thereby leading to impregnation of the brackets with the substances contained in the smoke, for the purpose of reproducing in vitro the conditions of a smoker’s oral cavity, for equal exposure of all brackets to cigarette smoke. the brackets were ligated with stainless steel ligature wires and putted into a chamber by fixing onto a supporting stainless steel holder that would allow the samples to remain in the same vertical position, so that the greater part of their surface would be exposed to the cigarette smokefig (2). figure 2: smoking equipment used in the study. j bagh college dentistry vol. 27(2), june 2015 effect of the pedodontics, orthodontics and preventive dentistry138 staining procedure: v preparation of staining solutions : ¸ tea: the tea solution was prepared by immersing 5 teabags in 500 ml of boiling distilled water for 10 minutes ¸ pepsi : new cans of pepsi were used for each day. v immersion in the staining solutions each bracket was stored in a solution in inert plastic containers and labeled with sticky labels and stored at 37°c in the incubator,all solutions were regularly renewed after every 24 hours of storage. the total storage period was 14 days ¸ cigarette for each bracket, 20 cigarettes were used for each day and each cigarette was burned in a standard time of 10 min in a total period of 14 days ,after exposure to every 20 cigarette the brackets were cleaned by ultrasonic cleaner(vgt1740qt, china) to eliminate excesses of substances from the smoke adhered to the bracket surfaces after this, the bracket putted back into its respective container containing distilled water and stored at 37°c in the incubator( memmert, germany) until the next time it was exposed to smoke spectrophotometric analysis the color change readings were made using a spectrophotometer, uv-visible spectrophotometer (shimadzu, uv-1800, japan), with wavelength range 200-800 ŋm with double beam analytical holders. to allow the standard positioning of the brackets during the reading, the bracket of each group and subgroup positioned on black rectangular cardboard segments (40×15×0.2 mm) with a central window at (17 mm) from the bottom to be in the way of the light beam of the spectrophotometer. before the readings, each bracket was taken out of the immersion media and washed by ultrasonic cleaner for one minute and properly dried on paper towels (10-12). before color reading the spectrophotometer was calibrated by opening the chamber and putting two black card boards without window on the two analytical beam holders and then the chamber closed and the device given the order auto zero to eliminate the effect of the black card board after that the chamber of the spectrophotometer was opened and the bracket was positioned in a standardized upright position with the black card board fig.(3), then the chamber is closed and the machine is given the order to start scanning starting from 800ŋm wavelength in the infra-red zone to 200ŋm wavelength in the uv zone passing through the entire visible spectrum. the results appear as a graph from which the amount of light absorption is plotted as a graph and the amount of absorbed light at a specific wavelength was obtained. for all the samples the light absorption at 345ŋm wavelength visible light was obtained and used in the later statistical analysis. figure 3: the bracket positioned on the analytical beam holder of the spectrophotometer and the blank on the other analytical beam holder. statistical analysis data were collected and analyzed using spss (statistical package of social science) software version 15 for windows xp chicago, usa. the following statistics were used: adescriptive statistic: including mean, standard deviation, statistical tables and graphical presentation by bar charts. binferential statistics 1one way analysis of variance test (anova) was used to examine anysignificant difference between more than two groups. 2lsd test was used to find any statistical significant difference between any two groups. p value of more than 0.05 was regarded as statistically insignificant as follows: ns non-significant p>0.05 s significant 0.05≥p>0.01 hs highly significant p≤0.01 results comparison between adhesive materials the amount of incremental increase in light absorption by sapphire brackets bonded with resilience, enlight and transbond adhesives when immersed in staining materials at three time intervals was shown in table 1 and table 2. j bagh college dentistry vol. 27(2), june 2015 effect of the pedodontics, orthodontics and preventive dentistry139 table 1: descriptive statistics and adhesive difference in each duration for pepsi, tea and cigarette smoke by anova test. media duration adhesives descriptive statistics comparison (d.f.=29) mean s.d. f-test p-value pe ps i d .w . 1 day resilience -0.001 0.001 0.040 0.961 (ns) enlight -0.001 0.001 transbond -0.001 0.002 7 days resilience 0.005 0.001 31.695 0.000 (hs) enlight 0.001 0.000 transbond 0.002 0.001 14 days resilience 0.009 0.001 104.871 0.000 (hs) enlight 0.002 0.001 transbond 0.006 0.001 t ea d .w . 1 day resilience 0.015 0.001 575.446 0.000 (hs) enlight 0.004 0.001 transbond 0.005 0.000 7 days resilience 0.021 0.001 425.474 0.000 (hs) enlight 0.008 0.001 transbond 0.011 0.001 14 days resilience 0.028 0.001 197.129 0.000 (hs) enlight 0.015 0.002 transbond 0.020 0.002 c ig ar et te s m ok e d .w . 1 day resilience 0.021 0.001 128.885 0.000 (hs) enlight 0.011 0.001 transbond 0.016 0.002 7 days resilience 0.039 0.001 840.875 0.000 (hs) enlight 0.021 0.001 transbond 0.028 0.001 14 days resilience 0.049 0.001 1324.121 0.000 (hs) enlight 0.025 0.001 transbond 0.038 0.001 table 2: difference between the different adhesives for light absorption after immersion in pepsi, tea and cigarette smoke by lsd test media duration adhesives mean difference p-value p ep si d .w . 7 days resilience enlight 0.004 0.000 (hs) transbond 0.003 0.000 (hs) enlight transbond -0.001 0.013 (s) 14 days resilience enlight 0.007 0.000 (hs) transbond 0.003 0.000 (hs) enlight transbond -0.004 0.000 (hs) t ea d .w . 1 day resilience enlight 0.012 0.000 (hs) transbond 0.010 0.000 (hs) enlight transbond -0.001 0.001 (hs) 7 days resilience enlight 0.013 0.000 (hs) transbond 0.010 0.000 (hs) enlight transbond -0.003 0.000 (hs) 14 days resilience enlight 0.013 0.000 (hs) transbond 0.009 0.000 (hs) enlight transbond -0.004 0.000 (hs) c ig ar et te s m ok e d .w . 1 day resilience enlight 0.010 0.000 (hs) transbond 0.005 0.000 (hs) enlight transbond -0.005 0.000 (hs) 7 days resilience enlight 0.019 0.000 (hs) transbond 0.011 0.000 (hs) enlight transbond -0.007 0.000 (hs) 14 days resilience enlight 0.024 0.000 (hs) transbond 0.011 0.000 (hs) enlight transbond -0.013 0.000 (hs) j bagh college dentistry vol. 27(2), june 2015 effect of the pedodontics, orthodontics and preventive dentistry140 discussion it has been shown that the brand, the solution and storage time influence the degree of color change of the materials and this is coming in agreement with villalta et al. (13). according to villalta et al. (13) and soares et al. (14) , the staining capacity of the composite resin is related to extrinsic factors, such as the pigment agent is subjected to, andto intrinsic factors, such as loading particles and resinous matrix. the structure of the composite resin and the characteristics of its particles have a direct impact on its susceptibility to staining by external agents. all types of adhesives tested in the present study stained by the staining media but with different extent, the enlight stained less than resilience and transbond and the transbond less than resilience. there is a correlation between discoloration and the filler component in resin composites, the higher contents of the filler in dental composites resulted in lesser discoloration than lower filled polymers , so a possible reason for the better color stability of enlight adhesive could be the elevated filler content of approximately70-80 percent by weight, while for resilience adhesive the filler content approximately 41 percent by weight and this is coming in agreement with(15-19), while for transbond adhesive the filler content of approximately70-80 percent by weight(as enlight adhesive) but it contain silane treated silica and silane treated quartz as a filler which explain the more stainability of this adhesive than enlight adhesive, it has been suggested that silanization of filler particles plays an important role in discoloration. this is due to the fact that silane has high water absorption levels and this is coming in agreement with (20). every component of resin may be implicated in discoloration. it has been shown that the resin matrix plays a major part in the color stability of composites and water sorption rate is of particular importance (21-23). it was found that incorporation of greater amounts of tegdma resulted in an increase in water uptake in bis-gma based resins; kalachandra (24) and mazato et al. 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identification of incompletely cured composite resins. j prosthet dent 1984; 52: 626-31. 22. øysæd h, ruyter i. water sorption and filler characteristics of composite for use in posterior teeth. j dent res 1986; 65: 1315–18. 23. choi k, ferracane j, hilton t, charlton d. properties of packable composites. j esthet dent 2000; 12: 216– 26. 24. kalachandra s, turner dt. water sorption of polymethacrylate networks: bis-gma/tegdm copolymers. j biomed mater res 1987; 21:329–38 25. mazato s, tarumi h, kato s, ebisu s. water sorption and colour stability of composites containing the antibacterial monomer mdpb. j dent1999; 27:279– 83. 26. arima t, hamada t, mccabe jf. the effects of crosslinking agents on some properties of hema-based resins. j dent res 1995; 74:1597–601. الخالصة استخدام االسالك التجمیلیة والحاصرات التجمیلیة باالضافة الى البدء ب لقد ازدادت الحاجة الى استعمال االجھزة التقویمیة التجمیلیة في ھذه االیام مما دفع مقومي االسنان الى:الخلفیة .االشرطة المطاطیة التجمیلیة ھي نوع من انواع الحاصرات التقویمیة التجمیلیة ویبقى )sapphire(الخزفیة والحاصرات التقویمیة ,الحاصرات التقویمیة الشبیھة بلون االسنان انتجت من انواع مختلفة من المواد .استقرار لونھا ھو الشغل الشاغل لالطباء والمرضى على حد سواء المرتبطة مع ثالث )sapphire(الخزفیة الحاصرات التقویمیة تلوینعلى قابلیة ) الببسي ودخان السجائر,الشاي االسود(مختلفة ھي ملونةمواد اجریت ھذه الدراسة لتقییم تأثیر ثالثة ).resilience, enlight and transbond(من المواد الالصقة الضوئیة التصلب ھي انواع تم تقسیم ھذه الحاصرات وفقا لمواد الربط الى ثالث مجموعات رئیسیة تتكون كل مجموعة من مائة , ن حاصرة تقویمیة یاقوتیة تكونت ھذه الدراسة من ثالثمائة وستو:المواد والطرق صرة لكل منھم ثم كل بواقع ثالثون حا) الببسي ودخان السجائر,الشاي االسود ,الماء المقطر(وعشرون حاصرة تقویمیة وثم قسمت كل مجموعة الى اربع مجامیع فرعیة وفقا لمواد الغمر . باستعمال الحاضن م37في درجة حرارة ) سبعة ایام واربعة عشر یوما, یوم واحد( مجموعة الى عشرة حاصرات حسب الفترة الزمنیة للغمر .الجراء اختبار امتصاص الضوء (shimadzu, uv -1800)تم استخدام االشعة الطیفیة المرئیة فوق البنفسجیة .p ≤ 0.05 لتحدید تأثیر المواد الملونة عند مستوى داللة ) lsdو anova (العملیة االحصائیة واستخدمت:النتائج .ًااربعة عشر یوموقد لوحظ اعلى نشاط في الفترة الزمنیة ) sapphire(وقد وجد ان وقت الغمر یؤثر تدریجیًا على االستقرار اللوني للمواد الالصقة مع الحاصرات التقویمیة ان وجد وقد.enlightالالصقالحاصرات المثبتھ ب واخیرًا transbondالالصقثم تلیھا المثبتھ بًا ھي االكثر تلون resilienceلتقویمیة المثبتھ بالالصق الضوئي التصلب الحاصرات ا .دخان السجائر ھو اقوى المواد الملونة یلیھا الشاي االسود واخیرا الببسي .لنتائج اعاله ان نوعیة المواد الالصقة یجب ان تؤخذ بنظر االعتبار عند استخدام الحاصرات التقویمیة التجمیلیةنستطیع ان نستخلص من ا:االستنتاجات .المواد الملونة,االستقرار اللوني,الحاصرات الیاقوتیة:الكلمات المفتاحیة journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 65 review article minimally invasive access cavities in endodontics lubna a. abdulrazaq 1*, ahmed h. ali 2, federico foschi 3 1. master student, aesthetic and restorative dentistry department, college of dentistry, university of baghdad, baghdad, iraq. 2. assistant professor, aesthetic and restorative dentistry department, college of dentistry, university of baghdad, baghdad, iraq. 3. program director msc in endodontics, honorary senior clinical lecturer, faculty of dentistry, oral & craniofacial sciences, king’s college london, guy's hospital, tower wing, floor 22, london, uk. * correspondence email; lobna.abdulwahab1204a@codental.uobaghdad.edu.iq abstract: background: the access cavity is a critical stage in root canal therapy and it may influence the subsequent steps of the treatment. the new minimally invasive endodontic access cavity preparation concept aims to preserve sound tooth structure by conserving as much intact dentine as possible including the pulp chamber's roof, to keep the teeth from fracturing during and after endodontic treatment. while there is great interest in such access opening designs in numerous publications, still there is a lack of scientific evidence to support the application of such modern access cavity designs in clinical practice. this review aims to critically examine the literature on minimal access cavity preparations, explain the effect of minimally invasive access cavity designs on various aspects of root canal treatment, and identify areas where additional research is required. data: an electronic search for englishlanguage articles was performed using the following databases: google scholar, pubmed, and research gate. the following keywords were used: "minimally invasive access cavity", "conservative endodontic cavity ", and "classification of access cavity". study selection: 64 papers that were the most relevant to the topics in this review were selected between 1969 to 26 february 2022. conclusions: minimally invasive access cavities can be classified into conservative, ultraconservative, truss access, caries and restorative-driven cavities. there is a deficiency of proof that a minimally invasive access cavity maintains the resistance to fracture of endodontically treated teeth greater than traditional access cavities. there was no difference in the percentage of untouched walls and debris removal in teeth with conservative vs traditional access cavities, however, truss and ultraconservative access cavities resulted in poor irrigation efficacy compared to traditional ones. also, the lower cyclic fatigue resistance of rotary instruments and root canal obturation with voids were associated with minimally invasive access cavities. the studies about minimally invasive access cavities still have a wide range of methodological disadvantages or register unsatisfactory or inconclusive results. therefore, further research on this topic is needed especially with the everyday advancement of techniques and armamentarium used in endodontics. keywords: conservative access cavity; fracture strength of endodontically treated teeth; minimally invasive access cavity; truss access. introduction one of the most critical steps of root canal therapy is access cavity (ac) preparation (1), as it will influence the subsequent steps and the outcome of the treatment. residues of pulp tissue that can serve as a substrate for microorganisms should be cleaned through proper access cavities (2). also, coronal interference elimination enables the detection of the orifices of root canals (3) and serves as a pathway for irrigation solutions to get a better effect of instrumentation and avoid accidents (4). the new philosophy of the preparation of minimally invasive access cavities seeks to conserve sound dentin by retaining as much as possible of the pulp chamber's roof (5). this shift was enabled by the availability of improved endodontic tools such as cone beam computed tomography (cbct), operating microscopes, and ultrasonic equipment (6). advocates of these approaches think that minimally invasive access cavities would aid in the long-term survival of endodontically treated teeth by minimizing unnecessary dentine removal, hence improving the fracture resistance of received date: 06-03-2023 accepted date: 06-04-2923 published date: 15-06-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/lice nses/by/4.0/). https://doi.org/10.26477/jb cd.v35i2.3406 https://orcid.org/0009-0004-3252-3436 https://orcid.org/0000-0002-1083-9913 https://orcid.org/0000-0001-6901-0280 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3403 https://doi.org/10.26477/jbcd.v35i2.3403 j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazaq et al. 66 endodontically treated teeth (5, 7). while the claim of avoiding tooth fracture has yet to be clinically proven, there have been concerns raised about the possible disadvantages of minimally invasive access cavity techniques. a limited access cavity design, for example, presents issues in future procedural stages such as an impaired vision of the pulp chamber and canal, decreased efficacy and efficiency in canal instrumentation and disinfection, and loss of orientation (8, 9) in addition to the morphology of the root canal system which is diverge and unpredictable and associated with clinical complications that have a direct impact on treatment outcome (10). while there is considerable interest in such access opening design techniques in many articles published on this topic, to date, there is a lack of scientific proof to back up the implementation of these modern access cavity designs in clinical practice for the present time (11). at the same time, clinicians are increasingly favoring access cavity designs that adopt minimally invasive principles (12). although the necessity of conserving tooth structure is self-evident, the entire shift to minimally invasive access cavities has yet to be confirmed (13). this review aims to provide an overview of the different designs of the minimally invasive access cavities in endodontics, summarize the research investigating their effects on the various aspects of endodontic treatment to date, and identify areas where additional research is required. methods a comprehensive search has been performed on electronically published resources in the english language using google scholar, pub med, and research gate databases from 1969 to february 2022 by using the keywords: "minimally invasive access cavity", "conservative endodontic cavity", and "classification of access cavity". sixty-four papers were included in this review. the studies were selected according to the following criteria: no social media sources were included, articles, literature reviews, in vitro studies, micro ct studies, finite element studies, retrospective studies, and cross-sectional studies that are related to the minimally invasive access cavities in root canal treatment. the filtering process included selecting the studies based on their relevance to the topics in this review. classification of access cavity designs traditional access cavity (trad ac) carried out over the past decades, seeking to allow straight-line access to the apex by removing the coronal interference (14, 15). complete removal of the pulp chamber roof in posterior teeth, followed by straight-line access to the canal orifices with smoothly divergent axial walls, allowing all orifices to be visible and apparent within the outline shape. straight-line access is achieved in anterior teeth by removing the pulp chamber roof, pulp horns, and the lingual shoulder of the dentine, as well as extending the access cavity to the incisal edge (16). conservative access cavity (cons ac) such a design of access cavity was proposed by clark and khademi in 2010. preparation of posterior teeth usually begins at the occlusal surface’s central fossa. it expands with axial walls that are smoothly convergent only to the degree required to expose the canal orifices, retaining part of the roof of the pulp chamber (5). this form of access can also be performed by divergent walls (cons ac, dw) (17). in anterior teeth, the strategy includes transferring the place of entry from the cingulum on the lingual or palatal surface to the incisal edge by forming a narrow triangular or oval-shaped cavity retaining the horns of pulp and the full peri-cervical dentin (18), as shown in figures 1 and 2. ultra conservative access cavity (ultra ac) j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazaq et al. 67 such cavities begin as stated in the cons ac but with no additional expansions, preserving as great of the roof of the pulp chamber as feasible (7). when the lingual region of the crown has attrition or a significant concavity of an anterior tooth, the incisal edge can be accessed in the center, parallel to the tooth's long access, as shown in figures 1 and 2. truss access cavity (truss ac) this type of access cavity design aims to keep the dentinal bridge between two or more tiny cavities that are created to access the canal orifice in each root of multi-rooted teeth. to access the mesial and distal canals, two or three separate cavities might be created in mandibular molars, for example (19), as shown in figures 1 and 2. caries-driven access cavity (caries ac) access to the pulp chamber is gained in this design by eliminating caries while conserving all remaining dental structures, including the soft structure described as the underside of an architectural feature such as the ceiling, ceiling corner, or wall (20), as shown in figures 1 and 2. restorative-driven access cavity (resto ac) access to the pulp chamber is gained in a restored tooth with no caries by removing all or part of the existing restorations while conserving the remaining tooth structures (11), as shown in figures 1 and 2. straight-line-furcation (slf) and straight-line-radicular (slr) because the outlines of slf and slr are formed from the pulp space landmarks projected onto the occlusal surface of the teeth, they differ from other types of access designs. the reference of the straight line radicular (slr) access is related to the pulp horn position, but the straight line furcation design (slf) is based on the placement of the center of each canal at the level of furcation (21). slf and slr are not included in the new proposed classifications, but they have lately been used in clinics with the idea of dynamic ct– guided endodontic access treatments (22). figure 1: classification of different types of access cavity designs of posterior teeth (11). j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazaq et al. 68 figure 2: classification of different types of access cavity designs of anterior teeth (11). influence of minimally invasive access cavity on aspects of root canal treatment: the strength of the remaining tooth structure the causes of fractures in endodontically treated teeth include iatrogenic causes (tooth structure loss, effect of chemicals and intracanal medicament, effect of restoration and restorative procedures), and noniatrogenic causes (primary, which includes a history of recurrent pathology and anatomical position of the tooth, and a secondary effect of aging of dental tissue) (23). the loss of tooth structure is the most common cause of fracture in root-filled teeth. the preparation of the endodontic access cavity after the trad ac principles were considered the second largest cause of loss of tooth structure (24). therefore, an endodontically treated tooth's prognosis might be improved with a correct and minimized endodontic access cavity design (25). compared to traditional access cavities, less invasive access cavities may improve the fracture resistance of interproximal repaired teeth (26). with minimally invasive access preparations, fourteen studies estimated the fracture resistance of extracted teeth. while the fracture resistance of teeth with cons ac was greater than that of teeth with trad ac in five studies (27), no difference was seen in the remaining nine investigations (28). of the 14 studies, two studies did not specify how specimens were chosen (29), and there is a reduction in the anatomical matching of the samples (30). at the same time, the thickness of the pulp chamber and magnitude of the remaining tooth structure affect the tooth resistance to fracture also the age of the patient and extraction technique are not reported well (29, 31, 32). according to augusto et al. (2020), ultraconservative access cavities in endodontic treatment did not provide any advantages in fracture resistance of mandibular molars when compared to traditional endodontic access cavities (8). maske et al. (2021) assess if the access cavity design affects the fracture strength of endodontically treated and repaired molars, and they found that the kind of access cavity preparation does not affect endodontically treated teeth fracture strength (33). also, saberi et al. (2020) find that under thermal stress, the truss endodontic access cavity improves the fracture strength of endodontically treated teeth (34). in conclusion, according to the results of these studies, the impact of access cavity preparation on tooth strength is at best uncertain (11). there is insufficient information to make a definitive judgment about whether consac is better than tradac in terms of fracture resistance (35). therefore, more research is required to have a better judgment on whether the minimally invasive access cavity designs may preserve the fracture resistance of the endodontically treated teeth. j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazaq et al. 69 chemomechanical root canal preparation a suitably prepared access cavity is critical for the successful instrumentation and administration of irrigation solution into the root canal system (36). for evaluation of different designs of access cavity on chemomechanical canal preparation in endodontics, krishan, paque, and colleagues (2014) found a higher percentage of untouched walls after using cons ac in the mandibular first molar's distal canal preparation as compared with trad ac (27). by comparing trad ac to cons ac (37) in maxillary molars, trad ac to cons ac in mandibular incisors (18), and trad ac to ultra ac in maxillary premolars (11), no differences in the percentage of the untouched walls after shaping the root canals of maxillary molars (37), mandibular incisors (18) and maxillary premolars (11), were observed. these results demonstrate that a tiny access cavity may not jeopardize the proportion of untouched walls during root canal preparation. for the impact of different access cavity designs on the amount of accumulated debris, rover et al. (2017) found no difference when comparing maxillary molars with cons ac or trad ac (37), while silva et al. (2020) found that the preparation of maxillary premolar's canal with ultra ac was associated with a higher percentage of the debris when compared to cons ac and trad ac. it's also known that restricted penetration of irrigant, wedging of the needle, the effect of vapour lock, and issues related to sonic/ultrasonic/negative apical pressure irrigation are well-documented drawbacks of irrigating minimally enlarged canals (36). following the chemomechanical process using the rotary instrument in addition to irrigation with a traditional syringe, neelakantan et al. (2018) found a significant amount of pulp tissue remanent holdover in the mandibular molars' pulp chamber with truss ac as compared with trad ac (19), which will impair the disinfection procedure by contaminated pulp tissue remnants which act as a source of infection and diseases after treatment (2). the data suggest that there is no difference between the trad ac and cons ac in terms of hard tissue debris collection and untouched canal walls after preparation. however, teeth with the trad ac had more canal transportation than the cons ac (11). furthermore, the tiniest access cavities, such as truss ac and ultra ac, were linked to worse irrigation efficiency due to the retention of more pulp tissue and hard tissue debris after shaping treatment (11). however, the effect of the type of access cavity on bacterial decline is unknown, and more research is needed. augusto et al. (2020) found that in comparison to typical endodontic access cavities, ultraconservative endodontic access cavities did not give any advantages in the capacity to shape canals or the resistance to fracture of mandibular molars (8). while comparing the effects of cons ac and truss ac on the capacity for shaping and filling root canals, microbial decrease in canals, and pulp chamber cleaning during root canal therapy on mandibular molars, barbosa et al. (2020) found no significant differences in microbial decrease, while in comparison to cons ac, trad ac had a much smaller percentage of unprepared surface area and also, there were no variations in the proportion of dentine removed (38). also, xia et al. (2020) found that in single-rooted premolars, the untouched canal wall following instrumentation for trad ac was substantially lower than the untouched canal wall for cons ac (39). on the other hand, peng et al. (2022) found that after instrumentation using pro glider and wave one gold files, the cons ac had no significant negative effect on the efficacy of instrumentation as compared to the trad ac (40). doing a very small access cavity might compromise the stage of endodontic treatment by complicating or/and preventing the canal orifice detection and chemomechanical instrumentation and obturation processes (41). the potential for other complications, such as missed canal, deviation, and/or instrument fracture, may also be increased (41). the results of the studies are controversial on whether minimal invasive access cavities will impair the chemomechanical process or not. however, the ultra ac, was associated with a higher percentage of debris and untouched canal walls after preparation. obturation and retreatment j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazaq et al. 70 to evaluate the effect of access cavity design on root canal filling, niemi et al. (2016) estimated the consistency of the oval-shaped canal filling of mandibular premolars following cons ac or trad ac using radiographic image analysis (42). the smaller dimension of minimally invasive access impeded guttapercha cone adaptation and holds the accomplishment of the continuous condensation wave process. therefore, niemi et al. (2016), reported that a single cone approach and warm lateral compaction (wlc) would be the best option for canal filling in a tooth with minimally invasive access preparation (42). silva et al. (2020) compared the proportion of voids generated next to the root canal filling of two rooted maxillary premolars with round cross-sectional shapes in both ultra ac and trad ac teeth (9). according to the authors, the filling of the canal was not affected by access designs; however, even with an ultrasonic tip, magnification, and more treatment time, the operator was unable to remove the filling remnants from the chamber of the pulp before the restoration of teeth with ultra ac (11). the sectioning approach was utilized by niemi et al. (2016) to assess the performance of rotary systems in removing the substance of root filling from the oval-shaped canals of single-rooted mandibular premolars. they found that teeth with cons ac had a greater remnant of filling material on the wall of the root canal than teeth with trad ac (42). rover et al. (2020) found more voids in root canal filling in the minimally invasive group than in the traditional one, and the percentage of canal filling remnant material in the chamber of the pulp after the cleaning process was not significantly different among these groups (traditional and minimally invasive access cavities) (43). therefore, the minimally invasive access cavities were more likely to be associated with voids in root canal filling and a higher percentage of canal filling remnant material in the chamber of the pulp than the traditional ones, and more research is needed to confirm these results. restoration of endodontically treated teeth resin composites are the most common alternative for endodontically treated tooth restoration, especially in minimally invasive access cavities. they are more esthetic, faster, cheaper, and less invasive than indirect restorations (44). the small dimensions of minimally invasive access cavities combined with the retention of the pulp chamber roof complicate the incremental build-up restorative procedure and may result in adhesion failure and/or voids at the point where the restorative material meets cavity walls (45). silva et al. (2020) examined the effect of ultraconservative endodontic access cavities (ultra ac) on establishing gaps and voids in resin composite restorations; however, gaps and voids were seen in every specimen. there was considerable disparity in the creation of voids among the access cavity designs, with the ultra ac producing significantly higher voids. the creation of gaps was not significantly different between the trad ac and the ultra ac (46). boscatto et al. (2022) investigated the effect of endodontic access cavity design and restorative technique on hard tissue removal in mandibular premolars. in comparison to consac, tradac resulted in a 14% increase in hard tissue removal after endodontic treatment (47). the results of studies are controversial on whether the minimally invasive access cavity is associated with more voids and gaps in the resin composite restorations than traditional access or not, therefore future studies are required to investigate this point. tooth discoloration induced by endodontic materials and treatments is a concern in clinical practice, causing cosmetic issues and discomfort for both patients and professionals, especially in the anterior teeth (48). even with magnification, using an ultrasonic tip, and more treatment time, the operators were unable to bring out residues of filling substances from the chamber of pulp before restoration in teeth with ultra ac. this prolonged operating technique may cause fatigue in both the patient and the dentist, and the remnants of the filling may affect aesthetics by discoloring the dental crown over time (49, 50). cyclic fatigue of endodontic instruments j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazaq et al. 71 torsion failure and cyclic fatigue are two causes of endodontic instrument separation. when the instrument's tip becomes lodged in the dentin and the instrument continues moving, a torsion fracture occurs (51, 52). on the contrary, cyclic fatigue occurs when the forces of tension compression exceed the elastic limit of the instrument in the canal of the curved root (53). reduced access cavities might lead to a higher access inclination of the file into the root canals (4), in addition to anatomic curvature; it induces extra curvature (54). recent investigations have shown that inserting the file into the canal with a more inclined angle reduces the endodontic instruments' cyclic fatigue resistance (55, 56). in trad ac and ultra ac endodontically accessed canals, silva et al. (2020) compared the cyclic fatigue resistance of reciproc size 25 (r25) and reciproc blue size 25 (r25b) instruments; r25 and r25b in ultraac demonstrated muchreduced cycle fatigue resistance (57). also, spicciarelli et al. (2020) found that in endodontically treated teeth using cons ac, the cyclic fatigue resistance of reciproc blue r25 was drastically reduced compared to trad ac (58). also, when corsentino et al. (2021) compared conservative and truss access cavities, they discovered that the truss access cavity produces higher fatigue of reciproc blue r25 than the conservative access cavity (59). the studies included in this review showed that minimal invasive access cavities were associated with lower fatigue resistance of endodontic instruments than traditional access cavities. more studies are required to assess new niti rotary instruments' fatigue. effect on the cuspal deflection the loss of tooth structure caused by caries and restorative therapies, rather than the endodontic operations themselves, weakens endodontically treated teeth (60). the extent of cusp displacement during resin composite repair is determined by several parameters, including the restorative material's characteristics, the cavity's size and structure, and the bonding mechanism (61, 62). taha et al. (2009) conducted research on tooth strain, cuspal deflection, marginal leakage, and gap development induced by polymerization shrinkage through direct resin composite restoration of endodontically treated premolars (63), and they found that cuspal deflection and strain were increased as a result of loss of axial walls through endodontic access. gonzález-lópez et al. (2006) examined the influence of each consecutive cavity formation process on premolar cuspal deflection (including endodontic access). the cavity preparations were performed in the following order: unmodified tooth, conservative mo cavity preparation, extensive mo preparation, mo preparation with endodontic access, and mod preparation with endodontic access. they found that cuspal deflection increased statistically significantly after mod cavity preparation with endodontic access and concluded that progressive removal of dental tissue increased cuspal deflection (64). as a result, it is critical to keep the tooth structure intact wherever possible during the preparation of the access cavity. further studies are needed to discover whether minimal invasive access cavities will decrease the cuspal deflection or if there will be no difference between traditional and minimally invasive access cavity designs. conclusion various acronyms suggested to describe the new minimally invasive access cavity preparation have seriously undermined the articles' comprehension and readability, and new nomenclature is suggested based on self-explanatory abbreviations. according to the collected scientific data, there is a deficiency of solid proof to back up the consideration that a minimally invasive access cavity preserves the resistance to fracture of endodontically treated teeth greater than a traditional access cavity. the studies about minimally invasive access cavities still have a wide range of methodological disadvantages or have registered unsatisfactory or inconclusive results. in addition, the truss access cavity and ultra-conservative access cavity are more conservative types of access cavity that badly influence the irrigation process and canal transportation and, especially in necrotic teeth, aren't recommended. j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazaq et al. 72 in considering that more additional research is needed to give comprehensive and conclusive evidence about all these topics, it may be considered that there is a lack of proof for supporting and introducing the concept of minimally invasive access cavity preparation in daily clinical practice and also for training the students and post-graduates. although the necessity of conserving tooth structure is self-evident, the entire shift to minimally invasive access cavities has yet to be confirmed. minimally invasive access cavities are yet to be adequately proven by data from research, and they will not be able to take the place of typical straight-line access designs. before clinical trials can be planned, more in-vitro investigations must be completed. furthermore, before these new methods are generally adopted, randomized controlled trials, as well as retrospective and prospective investigations, must be performed. conflict of interest: none. refferences 1. yahata y, masuda y, komabayashi t. comparison of apical centring ability between incisal‐shifted access and traditional lingual access for maxillary anterior teeth. aust endod j. 2017;43(3):123-128. 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(crossref) العنوان: تجاويف الوصول طفيفة التوغل في عالج جذور األسنان federico foschi , علي امدح أحمد ، الرزاق عبد الوهاب عبد لبنى باحثون:ال المستخلص: األسنان بنية على الحفاظ إلى التوغل طفيف اللبية تجويف لتحضير الجديد المفهوم يهدف .للعالج الالحقة الخطوات على يؤثر وقد الجذر قناة عالج في حرجة مرحلة المدخل تجويف يعتبر :الخلفية هذه بمثل كبيًرا اهتماًما هناك أن حين في .اللبية المعالجة وبعد أثناء الكسر من األسنان على للحفاظ ، اللب حجرة سقف ذلك في بما اإلمكان قدر السليم األسنان عاج على الحفاظ خالل من السليمة إلى هذه العرض إعادة تهدف .السريرية الممارسة في الحديثة الوصول تجويف تصاميم تطبيق لدعم العلمية األدلة في نقص هناك يزال ال ، المنشورات من العديد في للقبول االفتتاحية التصاميم وتحديد ، الجذر قناة معالجة من مختلفة جوانب على التوغل طفيفة الوصول تجويف تصميمات تأثير وإبراز ، نقدي بشكل الوصول تجويف تحضيرات من األدنى بالحد الخاصة األدبيات فحص .إضافيًا بحثًا تتطلب التي المجاالت :التالية الرئيسية الكلمات استخدام تم gate. research و pubmed و: scholar google التالية البيانات قواعد باستخدام اإلنجليزية باللغة مقاالت عن إلكتروني بحث إجراء تم :البيانات ."الوصول تجويف تصنيف" و ، "المحافظ اللبية تجويف" ، "بضعاً األقل الوصول تجويف" .2022 فبراير 26 و 1969 عامي بين المراجعة هذه في بالموضوعات صلة األكثر كانت بحثية ورقة 64 اختيار تم :الدراسة اختيار تجويف أن على الدليل في نقص هناك .تصالحية مدفوعة تجاويف ، تسوس ، تروس وصول ، التحفظ شديدة ، محافظة تجاويف إلى التوغل طفيفة الوصول تجاويف تصنيف يمكن :االستنتاجات الحطام وإزالة تمسها لم التي للجدران المئوية النسبة في فرق هناك يكن لم .التقليدية الوصول تجاويف من أكبر أسنان بشكل المعالجة األسنان في الكسر مقاومة على يحافظ التوغل طفيف الوصول ارتبطت ، أيًضا .التقليدية باآلليات مقارنة الري كفاءة ضعف التحفظ شديدة الوصول وتجاويف تروس تجاويف عن نتج ، ذلك ومع ، التقليدية التجاويف مقابل المحافظة التجاويف ذات األسنان في واسعة مجموعة على تحتوي التوغل طفيفة الوصول تجاويف حول الدراسات تزال ال .التوغل طفيفة وصول بتجاويف بالفراغات الجذر قناة وسد الدوارة لألدوات السفلية الدوري اإلجهاد مقاومة جذور عالج في المستخدمة واألسلحة للتقنيات اليومي التقدم مع خاصة الموضوع هذا حول البحث من مزيد إلى حاجة هناك ، لذلك .قاطعة غير أو مرضية غير نتائج تسجل أو المنهجية العيوب من .األسنان https://doi.org/10.1016/j.joen.2019.11.015 https://doi.org/10.1007/s00784-020-03694-7 https://doi.org/10.3389/fdmed.2020.575010 doi:%2010.23937/2469-5734/1510125 https://doi.org/10.1016/s0099-2399(89)80191-8 https://doi.org/10.1016/j.dental.2003.05.008 https://doi.org/10.1016/j.dental.2004.05.005 https://doi.org/10.1016/j.jdent.2009.05.027 https://doi.org/10.2341/04-165 type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 1 research article tooth wear in relation to physical salivary characteristics among gastroesophageal reflux disease marwa siddik abdulrazak 1*, alhan ahmed qasim 2, ali ismael falih3 1. master student. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad. baghdad-iraq. 2. assistant professor. department of pedodontics and preventive dentistry. college of dentistry. university of baghdad. baghdad-iraq. 3. gastroenterologist at iraqi health ministry. arabic board in gastroenterology and hepatology, baghdad-iraq. *correspondence :email, marwa.siddik92@gmail.com abstract: background: gastroesophageal reflux disease, is a quite prevalent gastrointestinal disease, among which gastric content (excluding the air) returns into the oral cavity. many 0ral manifestations related t0 this disease include tooth wear, dental caries also changes in salivary flow rate and ph. this study was conducted among gastroesophageal reflux disease patients in order to assess tooth wear in relation to salivary flow rate and ph among these patients and the effect of gastroesophageal reflux disease duration on this relation. materials and methods: one hundred patients participate in this cross-sectional study for both genders and having an age range of 20-40 years old, patients had been endoscopically identified as having gastroesophageal reflux disease using the classification of los angeles (la), who were attending the gastroenterology and hepatology teaching hospital in baghdad. and divided into two groups: group a with grade severity mucosal breakage not longer than 5 mm and group b with grade severity mucosal breakage more than 5 mm long, smith and knight (1984) tooth wear index criteria were used for the assessment of tooth wear. for measurement of salivary flow rate and ph, saliva sample (unstimulated) had been collected. results: of the entire sample (90%) were having tooth wear. tooth wear was higher in grade b severity than in grade a severity among patients with gastroesophageal reflux disease duration of two years or less, while it was higher in grade a than in grade b among patients with a duration of more than two years but all these results were statistically non-significant. salivary flow rate and ph showed a non-significant reduction with increasing gastroesophageal reflux disease severity for both of groups concerning disease duration. the correlation of total tooth wear with salivary flow rate and ph was a significantly weak negative correlation in grade a, while a nonsignificant weak negative correlation in grade b. conclusions: the findings of the present study concluded that patients with gastroesophageal reflux disease recorded a high occurrence of tooth wear and there was a negative correlation of tooth wear with salivary flow rate and ph among patients with gastroesophageal reflux disease. keywords: gastroesophageal reflux disease, gerd, tooth wear, salivary flow rate, ph. introduction diagnosing many systemic diseases by observation of their oral manifestation possibly makes the dentist the primary health care professional to diagnose such diseases. gastroesophageal reflux disease (gerd) could be one of such disease, which could be evidenced by the observation of an unexplained presence of tooth wear (dental erosion) (1, 2). the return 0f stomach contents 0ther than air 0r the esophagus is known as gastroesophageal reflux. the term "gastroesophageal reflux disease" (gerd) refers to reflux that causes a variety of symptoms and, or damages or impairs the mucosa of the esophagus or neighboring upper aerodigestive system organs and occasionally the lower respiratory tract(3). received date: 14-03-2022 accepted date: 21-04-2022 published date: 15-06-2023 copyright: © 2022 by the authors. the article is published under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/li censes/by/4.0/). https://doi.org/10.26477/ jbcd.v35i2.3392 mailto:marwa.siddik92@gmail.com https://orcid.org/0009-0000-3790-6664 https://orcid.org/0000-0003-0682-664x https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3392 https://doi.org/10.26477/jbcd.v35i2.3392 j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazak et al 2 the effects of gastroesophageal reflux disease are not just restricted to the esophagus, but have also frequently been linked to several extra-esophageal involvements (4). heartburn, regurgitation and dysphagia represent the classical gerd symptoms (5, 6). in contrast, extra-esophageal symptoms of gerd might include a broad spectrum of illnesses such as nocardiac chest pain, posterior laryngitis, chronic coughing, recurrent pneumonitis, asthma, tooth erosion, and sleeping disorder (7). dental erosion, dental caries, halitosis, a burning sensation, xerostomia, and erythemia of the uvula and palatal mucosae could be the most frequent oral manifestations of gerd (8). long durations of gastroesophageal reflux disease have been related to an elevated risk of gerd physical complications which could include local esophageal complications, extraesophageal complications, asthma and even esophageal adenocarcinoma (9). tooth wear, also known as tooth surface loss, represent the pathological tooth tissue loss caused by a disease process differs from dental caries (10, 11). it occurs as a result of the three processes (attrition, abrasion, and erosion) interaction that can occur, each one alone or in combination (12). tooth wear etiology is mostly multifactorial as a result of local, systemic, mechanical, biological, chemical and\or tribological factors (1315). evidence suggests that tooth wear is a frequently reported extra-oesophageal symptom of gerd (16). saliva can be defined as the biologically produced, watery secretions of the salivary glands found in both human and animal oral cavities (17). several functions were served by human saliva including moistening and lubrication, digestion, taste and smell, wound healing factors, protection of the oral and esophageal mucosa and tooth protection (18). multiple studies found that there was a significant association between gerd, reduction in salivary flow rate and the subjective “dry mouth” sensation (xerostomia) (19, 20). when compared with controls, salivary flow rate and ph were found to be lowered among gerd patients (21). as soon as there was no previous iraqi study on the effect of gerd on oral health, this study was conducted in order to assess tooth wear in relation to salivary flow rate and ph among those patients, the null hypotheses was that there is no relationship between the occurrence of tooth wear and reduced salivary flow rate and ph in patients that having gastroesophageal reflux disease. materials and methods after receiving official approval from the college of dentistryuniversity of baghdad's research ethics committee, this cross-sectional study was conducted. it was carried out during the period from the end of march 2021 until the end of september 2021. a pre-study consent form was assigned to all the patients who participated in this study. 100 subjects with gastroesophageal reflux disease (gerd), including both genders and with an age range of 20 to 40 years old, make up the study sample. according t0 the los angeles (la) classification, which divides gerd into 4 grades depending 0n the severity and extent of mucosal breakage, the patients were classified by the specialist (a gastroenterologist) as having any grade of gerd (labeled a through d). the first grade is (a) which denotes one or more mucosal breakage that their length are not exceeding 5 mm and not continuous between the peaks of two or more mucosal folds, the second grade is (b) that denotes there is one or more breakage and their length is more than 5 mm and not continuous between the peaks of two or more mucosal folds, and the third grade is (c) which denotes that breakages are continuous between the peaks of two or more mucosal folds but less than 75% of the circumference of esophageal mucosa will be involved, and the last grade is (d) which j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazak et al 3 denotes that the involvement of at least 75% of esophageal circumference may be affected by mucosal breakage (9). during the study, only patients with grades a and b (54 patients (54%) and 46 patients (46%), respectively, met the inclusion and exclusion criteria for this study were found. all patients who attend baghdad's gastroenterology and hepatology teaching hospital who had been diagnosed as having gastroesophageal reflux disease by the use of endoscopy were included but had no prior history of any other systemic diseases. exclusion criteria: any patient who has another kind of systemic disease including diabetes, respiratory infection, cardiovascular disease, metabolic syndrome, patients wearing appliances, patients who are smokers, and patients receiving medication for any other disease. smith and knight (1984) tooth wear index criteria were used to examine and record the surfaces of all teeth (22), using a plain mouth mirror and light-emitting diode (led) headlight for illumination. the collection of unstimulated saliva was accomplished by passive drooling 0f saliva in graduated test tubes for five minutes, this was accomplished as directed by the university of southern california school 0f dentistry (23). previous to the starting 0f saliva samples collection, it should be confirmed by the patients that in the last hour, excluding water, they did not drink or eat anything. after washing the oral cavity with distilled (deionized) water, the patient was instructed to rest in a relaxed position for (5) minutes in previous to the beginning of collection process. during this procedure movement should be minimized, particularly the movement of the mouth. the patient is then told to swallow in order to clear the mouth of saliva while beginning the process with a slight mouth opening to allow saliva to dribble into the graded tube and with a forward inclination 0f the head. the last step, when the five minutes ended, the patients were instructed to gather all of the mouth's leftover saliva and expectorate it inside the tube, and this step should be achieved as fast as possible. the flow rate was then determined by dividing the milliliters (ml) 0f the entire saliva collected by the minute (min) it took to collect the saliva (24). salivary ph has been measured by using a digital ph meter by immersing it in the tube of the saliva sample, then waiting for about thirty seconds in order to have a stable reading and record the result. the ph meter was calibrated every day by using two ph solutions (ph=4.01, ph=7.01) as recommended by manufacturer instruction, then washing and disinfecting the head of the ph meter by washing it with running distilled water and then alcohol disinfectant was used and finally dried with filter paper. the statistical analysis was completed with the statistical package for social science (spss version -22, chicago, illinois, usa). using descriptive analysis which includes mean, standard error, and a cluster chart bar. inferential analysis was used as an independent sample t-test parametric test to determine the difference between the two groups. the pearson correlation parametric test was used to determine if two quantitative variables were linearly related. results from the whole sample (90%) was recorded tooth wear. regarding gerd severity, the prevalence of tooth wear was found to be higher among grade b(mucosal breakage longer than 5 mm) gerd severity than grade a(mucosal breakage not longer than 5 mm) gerd severity in different surfaces of both jaws except in lingual, mandibular buccal (mand.b.) and mandibular cervical (mand.cer.) surfaces as shown in figure (1). j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazak et al 4 table (1) illustrates tooth wear according to gerd severity by disease duration. the results showed that in patients with two years or less of tooth wear the mean value of tooth wear was higher in grade b, while the mean value of tooth wear was higher in grade a in patients with a duration of more than two years without statistically significant difference, except at mandibular buccal tooth wear in patients with a duration of more than two years. results of salivary flow rate (sfr) and ph among gerd severity in patients with a duration of two years or less and a duration of more than two years are illustrated in table (2). although sfr and ph were higher in grade a than in grade b in both durations, there was no statistically significant difference. ttw: total tooth wear, maxtw: maxillary tooth wear, maxoi: maxillary occlusal or incisal, maxb: maxillary buccal, maxcer: maxillary cervical, mandtw: mandibullar tooth wear, mando: mandibular occlusal, mandb: mandibullar buccal, mandcer: mandibular cervical. figure 1: the percentage of patients who have tooth wear in the total sample by severity of gastroesophageal reflux disease. a: one (or more) mucosal breakage not longer than 5 mm that does not continue between the peak of two esophageal mucosal folds. 0 10 20 30 40 50 60 70 80 90 100 a b % j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazak et al 5 b: one (or more) mucosal breakage more than 5 mm long that does not continue between the peak of two esophageal mucosal folds. table 1: descriptive and statistical test of tooth wear among severity of gastroesophageal reflux disease by disease duration. duration (years) gerd severity a b mean ±se mean ±se t test p value^ <=2 ttw 28.875 4.668 39.576 5.579 1.471 0.146 maxtw 14.344 2.317 21.545 3.003 1.899 0.062 maxoi 10.094 1.149 11.939 1.058 1.182 0.242 maxb 1.125 0.575 2.212 0.849 1.060 0.294 palatal 2.094 0.647 4.394 1.023 1.900 0.063 maxcer 1.031 0.556 3.000 0.896 1.867 0.067 mandtw 14.531 2.504 18.030 2.733 0.944 0.349 manb 0.844 0.533 1.727 0.803 0.917 0.363 mando 10.094 1.285 12.000 0.944 1.195 0.237 lingual 1.500 0.679 2.212 0.831 0.663 0.510 mandcer 1.781 0.750 2.091 0.836 0.276 0.784 2+ ttw 50.091 9.757 31.692 5.408 1.649 0.109 maxtw 26.000 4.811 17.615 3.400 1.423 0.164 maxoi 13.773 1.870 11.231 1.997 0.929 0.360 maxb 3.182 1.137 1.231 0.794 1.407 0.169 palatal 5.773 1.272 3.769 1.490 1.023 0.315 maxcer 3.273 1.181 1.385 0.805 1.321 0.196 mandtw 24.091 4.996 14.077 2.704 1.763 0.088 manb 3.636 1.207 0.154 0.154 2.862 0.009 mando 13.500 2.062 11.615 2.086 0.643 0.525 lingual 3.409 1.145 0.923 0.711 1.845 0.074 mandcer 3.545 1.150 1.385 0.805 1.539 0.133 total ttw 37.519 4.997 37.348 4.285 0.025 0.980 maxtw 19.093 2.493 20.435 2.354 0.387 0.699 maxoi 11.593 1.041 11.739 .935 0.103 0.918 maxb 1.963 .585 1.935 .648 0.032 0.974 palatal 3.593 .684 4.217 .839 0.583 0.561 maxcer 1.944 .596 2.543 .686 0.663 0.509 mandtw 18.426 2.573 16.913 2.105 0.445 0.657 mandb 1.981 .608 1.283 .585 0.821 0.414 mando 11.481 1.145 11.891 .885 0.276 0.783 lingual 2.278 .623 1.848 .631 0.482 0.631 mandcer 2.500 .650 1.891 .639 0.663 0.509 j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazak et al 6 table 2: descriptive and statistical test of salivary flow rate and ph among gerd severity by duration. duration (years) gerd severity a b mean ±se mean ±se t p value <=2 sfr 0.563 0.050 0.497 0.050 0.934 0.354 ph 6.622 0.070 6.588 0.073 0.334 0.740 2+ sfr 0.464 0.054 0.346 0.071 1.318 0.197 ph 6.650 0.093 6.569 0.106 0.554 0.583 total sfr 0.522 0.037 0.454 0.042 1.221 0.225 ph 6.633 0.056 6.582 0.060 0.620 0.537 sfr: salivary flow rate ph: salivary ph results in table (3) show that tooth wear's correlations with ph and sfr are not significant weak correlations in the severity of group b gerd, while significant negative weak correlations with sfr in group a gerd severity, while in ph with group a, a non-significant negative weak correlations are found in palatal, max. and mand. cerv., and mand. bw. table 3: correlations of tooth wear with salivary flow rate and ph in gerd severity. vars. sfr gerd severity ph gerd severity a b a b r p value r p value r p value r p value ttw -0.369* 0.006 -0.210 0.161 -0.379* 0.005 -0.153 0.309 maxtw -0.363* 0.007 -0.182 0.225 -0.380* 0.005 -0.184 0.220 maxoi -0.278* 0.042 0.060 0.692 -0.419* 0.002 -0.222 0.138 maxb -0.287* 0.036 -0.204 0.173 -0.308* 0.024 -0.147 0.330 palatal -0.410* 0.002 -0.213 0.155 -0.260 0.058 0.040 0.789 maxcer -0.280* 0.041 -0.254 0.088 -0.259 0.059 -0.240 0.108 mandtw -0.366* 0.007 -0.224 0.134 -0.368* 0.006 -0.106 0.481 mando -0.303* 0.026 -0.033 0.827 -0.414* 0.002 -0.146 0.333 mandb -0.328* 0.016 -0.186 0.215 -0.183 0.185 0.008 0.957 lingual -0.292* 0.032 -0.263 0.078 -0.285* 0.037 -0.073 0.631 mandcer -0.266* 0.052 -0.263 0.077 -0.239 0.082 -0.084 0.579 *=significant atp<0.05, ttw: total tooth wear, maxtw: maxillary tooth wear, maxoi: maxillary occlusal or incisal, maxb: maxillary buccal, maxcer: maxillary cervical mandtw: mandibullar tooth wear, mando: mandibular occlusal, mandb: mandibullar buccal mandcer: mandibular cervical. j. bagh. coll. dent. vol. 35, no. 2. 2023 abdulrazak et al 7 discussion in spite of symptomatic gerd becoming a common condition in our population and chronic duration of the disease have been recognized among gerd patients (25), there are no previous reports in the literature on the oral findings among gerd patients in iraq. considering the upper gastrointestinal (gi) endoscopy as the gold standard for gerd confirmation (26) for this reason the included patients in this study were those who had been diagnosed as having gerd by the use of upper gi endoscopy. the patients were diagnosed and classified according to the los angeles (la) classification (9). there is strong evidence linking changes in the oral cavity to alterations in systemic health (27, 28). due to the fact that the oral cavity is a component of the digestive system, gastrointestinal illnesses may appear as oral disorders (29). in this study a high frequency of tooth wear was found in this study (90%) these results were similar to those found in previous studies (18, 30-33) who reported a significant association between tooth wear and gerd. unlike the results of jensdottir and colleagues who reported a low prevalence of dental erosion among gerd patients (34). results of this study concerning gerd duration found that patients with tooth wear were higher in grade b than in grade a among patients with a duration of two years or less, while tooth wear was higher in grade a than grade b among patients with longer duration (more than two years), this could be explained by that gerd patients did not tend to cross over from one grade to another in a follow-up periods range from (6) months to longer than (22) years (35, 36). in this study, salivary flow rate and salivary ph were higher in grade a than in grade b although without statistically significant differences, but these results agree with the results found by preetha et al. (37) who found that there was an inverse relationship between salivary flow rate and ph and gerd severity grade. furthermore, tooth wear’s correlation with salivary ph and salivary flow rate is a negative correlation in both grade a and b severity which agree with agbor et al. (38) and this could be due to the reduction of salivary flow rate among gerd patients (33) as long as saliva is considered to be the main defense mechanism from acid exposure present in the oral cavity so any change in the amount and quality of saliva will affect its defensive roll by acid clearance and neutralization (39). while lowered ph of the oral cavity due to acid reflux could lead to the dissolution of the inorganic material of the teeth (dissolution of hydroxyapatite crystals in the tooth enamel), and then to dental erosion making the teeth to be predisposed to friction (wear of the tooth) (40). conclusion from the present study, it could be concluded that a high incidence of tooth wear could be noticed among gedr patients and this would be related to salivary flow rate and ph reduction among gerd patients. gerd patients need to regularly visit a dentist to get proper preventive programs and a dentists physicians cooperation is very important to prevent or reduce further oral effects of gerd. conflict of interest: none. references 1. bartlett d, evans d, smith b. oral regurgitation after reflux provoking meals: a possible cause of dental erosion? j. oral rehabil. 1997;24(2):102-8. 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(crossref) المعدي المريئي االرتجاع بين مرض الفيزيائيةتآكل األسنان فيما يتعلق بخصائص اللعاب العنوان: علي إسماعيل فالح ,ألحان أحمد قاسم ,مروة صديق عبد الرزاق الباحثون: : المستخلص هواء إلى الفم. العديد من الخلفية: مرض االرتجاع المعدي المريئي ، وهو مرض منتشر جدا في الجهاز الهضمي ، والذي يمكن أن يحدث فيه عودة محتوى المعدة بخالف ال رجة الحموضة. أجريت هذه الدراسة على مرضى المظاهر الفموية المرتبطة بهذا المرض بما في ذلك تآكل األسنان وتسوس األسنان والتغيرات في معدل تدفق اللعاب ود المعدي المريئي على االرتجاع االرتجاع المعدي المريئي من أجل تقييم تآكل األسنان فيما يتعلق بمعدل تدفق اللعاب ودرجة الحموضة بين هؤالء المرضى وتأثير مدة مرض عية ، وكانوا يترددون على المستشفى التعليمي ألمراض الجهاز الهضمي والكبد في بغداد والذين تم هذه العالقة. المواد والطرق: شارك مائة مريض في هذه الدراسة المقط وكال الجنسين. تم استخدام معايير مؤشر عاًما 40-20( ، والذين تتراوح أعمارهم بين laتشخيصهم بالمنظار بمرض االرتجاع المعدي المريئي وفقًا لتصنيف لوس أنجلوس ) النتائج: من العينة .( لتقييم تآكل األسنان. تم جمع عينات اللعاب غير المحفزة لتقدير معدل تدفق اللعاب ودرجة الحموضة1984) smith and knightتآكل األسنان الغشاء )كسر aفي شدة الدرجة مم( منه 5)كسر الغشاء المخاطي بطول أكثر من b٪( كان لديهم تآكل في األسنان. كان تآكل األسنان أعلى في شدة الدرجة 90بأكملها ) بين bمما كانت عليه في الدرجة aمم( بين المرضى الذين يعانون من ارتجاع المريء لمدة عامين أو أقل ، في حين أنه كانت أعلى في الدرجة 5ال يزيد عن المخاطي الذين تزيد مدتهم عن عامين ولكن كل هذه النتائج كانت غير معنوية إحصائياً. ودرجة الحموضة انخفاًضا طفيفًا مع زيادة شدة مرض المرضى أظهر معدل تدفق اللعاب لبيًا ضعيفًا بشكل ملحوظ المريئي لكال المجموعتين فيما يتعلق بمدة المرض. كان االرتباط بين تآكل األسنان الكلي ومعدل تدفق اللعاب ودرجة الحموضة ارتباطًا س االرتجاع . االستنتاجات: خلصت نتائج الدراسة الحالية إلى أن مرضى االرتجاع المعدي المريئي سجلوا ارتفاعًا bسلبي الضعيف غير المعنوي في الدرجة بينما االرتباط ال aفي الدرجة تآكل األسنان وكان هناك ارتباط سلبي لتآكل األسنان مع معدل تدفق اللعاب ودرجة الحموضة بين مرضى االرتجاع المعدي المريئي. https://doi.org/10.1016/j.tripleo.2010.02.025 https://doi.org/10.1016/s1590-8658(03)00215-9 https://doi.org/10.1155/2014/818167 https://doi.org/10.1097/meg.0000000000000622 https://doi.org/10.1186/s12876-017-0650-5 https://doi.org/10.1007/s00784-003-0252-1 http://eprints.southarchive.com/id/eprint/223 https://doi.org/10.1111/j.1875-595x.2011.00063.x https://doi.org/10.1111/j.1601-0825.2007.01380.x j bagh college dentistry vol. 33(4), december 2021 root and root canal morphology 11 root and root canal morphology: study methods and classifications duaa m. shihab (1), anas f. mahdee (2) https://doi.org/10.26477/jbcd.v33i4.3014 abstract background: morphology of the root canal system is divergent and unpredictable, and rather linked to clinical complications, which directly affect the treatment outcome. this objective necessitates a continuous informative update of the effective clinical and laboratory methods for identifying this anatomy, and classification systems suitable for communication and interpretation in different situations. data: only electronic published papers were searched within this review. sources: “pubmed” website was the only source used to search for data by using the following keywords "root", "canal", "morphology", "classification". study selection: 153 most relevant papers to the topic were selected, especially the original articles and review papers, from 1970 till the 28th of july 2021. conclusions: this review divided the root canal analysis methods into two approaches; clinical and in vitro techniques. the latter has shown more precise non-subjective readings, on the other hand; the clinical methods provide direct chair side diagnosis for the clinical cases. the classification systems reviewed in the present study, started with the oldest trials that simply presented the root canal systems, according to the degree of angulation, or by coded latin numbers or english letters. then, the most recent systems were also presented that were persisted with continuous editions up to date. these new systems could briefly describe the root and root canal’s internal and external details in a small formulation, without confusion and in an easily communicated manner, highly recommended specially for students, teachers, and researchers keywords: root canal, root morphology, canal configuration, root canal classification, endodontic. (received: 20/8/2021, accepted: 22/9/2021) introduction tooth development is a complex biological process moderated by a series of epithelialmesenchymal interactions (1). these biological factors can abnormalize the ultimate process of odontogenesis causing a developmental anomaly. “anomaly is a greek word, meaning irregular; or in other words, it is a deviation from what is regarded as normal” (1). depending on the stage of tooth development, various anomalies in root/canal number, size and/shape can occur (1). the most common root malformations in humans arise from either developmental disorder of the root alone, such as root dilaceration and taurodontism or disorders of root development as a part of general tooth dysplasia, such as dentine dysplasia type 1 (2). there is a direct association of such developmental variations with pulp and periradicular diseases that may necessitate a multidisciplinary treatment approach (3-8). lack of knowledge about normal and abnormal (1) master student, department of restorative and aesthetic dentistry, college of dentistry, university of baghdad. (2) assistant professor, department of restorative and aesthetic dentistry, college of dentistry, university of baghdad. corresponding author, a.f.mahde@codental.uobaghdad.edu.iq root and root canal morphology is often associated with many failures to locate, instrument, irrigate and fill canals adequately (9, 10), therefore; identifying normal versus abnormal (aberrant) morphology of the human dentition is essential for effective root canal treatment procedures (9). with the increased range of anatomical complexities being reported and the deficiencies of existing systems for categorizing morphological variations, a new system for classifying root and canal morphology has been proposed, which provides detailed information on tooth notation, roots number and configuration, in addition to accessory canals and tooth anomalies, in simple a practical manner which will be focused on in this review (11-14). the presently available systems for describing the root and root canal morphology both under normal and abnormal conditions are plentiful and divergent with many interrelations in authors proposals, as they continue making their new additions depending on the preceding trials. the aim of this review is to do an electronic search and to collect most if not all of the reported methods for analyzing root canal morphology and classification systems, and summarizing them. https://doi.org/10.26477/jbcd.v33i4.3014 j bagh college dentistry vol. 33(4), december 2021 root and root canal morphology 11 methods in the present literature review, a comprehensive search has been made depending on electronically published peer-reviewed resources using the “pubmed” website, from 1970 till the 28th of july 2021. the used keywords were "root", "canal", "morphology", "classification", which revealed about 153 relevant papers. after filtering, only 67 papers, all in english language, were included in this review. the filtering process included papers striving most if not all of the available root and root canal classification systems, and methodologies are applied to dental morphological identification. the selected classification systems and methodologies were ensured to have well defined and standardized guidelines and steps in their criteria of work. 3. techniques for root canal analysis there are different methods that have been reported for studying root canal morphology, ranging from in vitro (experimental) methods, to those which are more suitable for clinical situations (in vivo). 3.1. in vitro techniques these are the most common techniques using extracted teeth for laboratory analysis of root morphology, serving scientists and authors in their ongoing researches. 3.1.1. root clearing and canal staining this technique is widely mentioned in literature and could be considered as the gold standard method for laboratory studies of root canal anatomy, and for comparison with readings from other techniques, because of its high accuracy and nondestructive approach (15). in clean extracted teeth with fully formed roots, ink is injected through the coronal access directly into the root canals, then the access cavities of the study teeth are filled and well-sealed, leaving the apical root opening patent for ink progression. these teeth could be stored in a high-pressure chamber to enhance penetration of the dye into the fine details of the tooth structure (16). now teeth are washed and dehydrated in an ascending concentration of ethanol up to 100%, then decalcified in a maintained active acidic solution over a day. teeth are then placed in methyl salicylate solution for a couple of hours rendering them transparent (17). to be sure that teeth are well decalcified, some of the samples are exposed to conventional radiation, examination is done by using a magnifying lens (×3). modified canal staining and root clearing were mentioned in this literature as it is non-destructive and more accurate than the conventional staining and clearing method (17). the main disadvantage of this method is that it cannot be used in vivo (17). a comparable method has the accuracy of the latter technique but at the same time clinically feasible, not yet available in endodontic practice. 3.1.2. radiographical analysis with contrast medium in this method, water-soluble low viscosity radiopaque medium is delivered into the root canals. the low surface tension of the contrast medium and subjection of the tooth to vacuum or ultrasonic waves enable penetration of the medium into the niches of the root canal system. then radiographs were taken in a buccolingual direction, in two horizontal angulations, 0˚and 30˚, after fixing the teeth on arch simulating models (18). alteration of the subject contrast is induced by variations in transmission of the radiographic beam between the tooth and the contrast medium, which definitely improves the visibility of root canal systems, in comparison with conventional radiographs (19). these altered exposures are more useful than plain radiographs in the assessment of root canal anatomy, but on the other hand, as the previous method, it cannot be used in vivo (20). 3.1.3. histologic examination teeth subjected for examination in this method should be processed by demineralization in an acidic solution of formic acid, citric acid, or edta for several weeks to be softer and ready for sectioning. root sections number and cutting intervals are determined depending on the study, but most commonly being sectioned at multiple intervals along the root course, then simply stained with hematoxylin-eosin for clear observation of the canals’ shape at each section (21). 3.2. in vivo techniques 3.2.1. two-dimensional imaging techniques in this part of imaging techniques, there are three different diagnostic tools including conventional, digital, and panoramic radiography, all of which share being a two-dimensional image of threedimensional structures, but differ in the imaging quality, resolution, and practicality (19). these diagnostic methods are still the first-line choice for before, during, and after work usage that should never be passed, taking into account the experience of the operator in manipulation and interpretation of results (19, 22). j bagh college dentistry vol. 33(4), december 2021 root and root canal morphology 11 3.2.2. three-dimensional techniques in this field, many attempts have been made to develop systems providing an optimum threedimensional visualization of the tooth internal complex and unpredictable anatomy, and to be feasible aids available in each dental clinic. o nonionizing radiation, a high-resolution magnetic resonance spectroscopy system constitutes a powerful tool for a detailed analysis of dental soft tissues (poor detection of hard tissue changes) (23). o magnetic resonance tomography (mrt) with stray field imaging (strafi) system produces powerful proton signals in a very short time (poor differentiation between hard tissue structures) (24). o constant-time imaging (cti) technique shows good resolution for both hard and soft tissue structures (195 µm), (limited description of the smallest components of the pulp chamber) (25). o 1ct is a miniaturized conventional computerized tomography offers crosssectional images of the roots and 3d shapes for root canal systems with resolution (36µm), which aids to detect geometrical changes after instrumentation (small field of exposure, long scanning time up to six hours) (26-28). o high-resolution x-ray computed tomography (hrxct): this development gives good quantitative data for dental structures (5-100µm) compared with histologic sections (nonpracticality, high cost, limited availability) (29, 30). o flat panel-based volume computed tomography (fp-vct): this technique shows good qualitative information about dental structures and exposes several teeth at one time (low spatial resolution (150µm), non-practicality, high cost, limited availability) (31). o peripheral quantitative computed tomography (p-qct): this innovation produces a good qualitative and quantitative representation of dental structures (not fully validated technique) (32). o micro-computed tomography (mct): noninvasive technique can evaluate internal and external dental anatomy non-invasively in both quantitative and qualitative values, can define even fine root canal communications and lateral canals (not suitable for clinical use) (22, 33). o cone-beam computed tomography (cbct): as a more recent development has been introduced for 3d imaging of hard tissues in the maxillofacial region, these devices are now more available, with high diagnostic quality (75450µm), short scanning time (10-70s), and less radiation dose than conventional ct (34-36). 4. root and root canal classification systems 4.1. old classification systems 4.1.1. mathematical classification of root canal curvatures first trials began with schneider (37) when he classified root canals on angular bases, according to the degree of curvature, into straight 5° or less, moderate 10-20°, and severe 25-70°. backman et al. (38) classified root canals on the basis of "radius quotient," which was obtained by dividing the root canal angle by its radius measurement. dobo (39) devised a classification based on schneider's angle and the radius of the circle that could be superimposed on the curved part of the root canal. baumann et al., dobo, and southard et al. (24, 39, 40) formulated their classifications using other data besides the schneiders angle to achieve a "semiquantitative" method for describing the shape of the curve of root canals, however, schneider's angle which depended on as a data for classification cannot describe the course of curve of the canal along the root. more recently published papers demonstrated the necessity of developing a more reliable classification that was presented by nagy et al. (41). this classification is based on computer graphic analysis, with the results described in four characteristic root canal forms symbolled with alphabetical letters (straight canals (i), canals curved in their apical part (j), canals curved along their length (c), and multi curved canals (s)). 4.1.2. diagrammatic representation of root canal configuration gupta and sexana (42) presented with a new diagrammatic root canal representation, which is supposed to be simple to understand, represent, and communicate, providing a clear picture about the location, number, and length of most root canal configurations. small details should also be included. the proposed representation consists of five horizontal lines, which divide the tooth into four partitions in a corono-apical direction. the first line, which is a dashed line signifies the point of reference from where the length of root canal is measured "ref". a second line, which is continuous, marked as ‘‘orf.’’ at one end, represents the orifice level or cemento-enamel junction in the case of a single canal or taurodont teeth. the lowermost line, which is j bagh college dentistry vol. 33(4), december 2021 root and root canal morphology 11 also continuous a one, represents the apical foramen of the root canal. then third and fourth lines (dotted lines) divides the root canal into coronal, middle, and apical thirds; these regions are designated as c, m, and a, respectively. the diagrammatic images of teeth (one anterior/posterior single-rooted and one posterior multi-rooted) are given for easy understanding of the orientation of an image. the whole image has a transparent background and is saved in a portable network graphics (png) format. the image can be rotated by 180˚ to correspond to either mandibular or maxillary teeth. it can be imported to any word processing document and a print of the image can be obtained in the reporting sheet. freehand vertical lines should be drawn from the top dashed line to the bottom continuous line, to represent the major root canals exist in the tooth, with each labeled at the top. the length of the individual canal from the point of reference to the apical foramen can be written in millimeters, depending on the situation, either adjacent to the origin of its corresponding line, near ‘‘ref.’’ line, or at the end, adjacent to the fifth line representing the apical foramen. intercommunications and isthmuses between the canals should be drawn keeping in mind the approximate level (coronal, middle, apical) for each. fusion between canals can be shown by one vertical line merging into another or both lines joining together at the corresponding level. bifurcation in the canal is represented by the division of the line at the corresponding third. the orientation of the resulting canals can be labeled in the area adjacent to the fifth line. in addition, the diameter of the canals can be represented by the relative thickness of the lines. lateral and accessory canals, if identified, can be shown as blind lines originating from the main vertical line and running in a horizontal direction at the corresponding locations. if the major canals, instead of appearing at the pulpal floor as separate orifice, continue as a single large canal and separate below the orifice, then the same can be represented as a thick band in the diagrammatic representation. the lines representing the divided canals, in such cases, can be labeled near the fifth line. if the major canals, instead of appearing at the apex in separate apical foramina, join and continue as single large canal, then also can be drawn as a thick band starting from the corresponding third. the above-mentioned rules can be simply summarized as ‘‘to draw what you see’’, see figure (1). this method still has many limitations, which are inherent in their two-dimensional representation of a three-dimensional network. it is not able to present neither the exact location of the canal orifices, nor the location and orientation of the canals. the lengths of the canals are out of proportion in order to simplify the procedure of drawing and segmenting the canals. figure (1): representation of canal configuration of maxillary left second molar having two roots, mesio-buccal and distopalatal. mesio-buccal root having two canals, mb1 and mb2 with separate orifices, which merge at the middle level. distopalatal root with two canals, db and p with separate orifices and merge in the apical third, having an identifiable isthmus in the middle third (42). 4.1.3 number-digits root canal classification systems in these systems the canals configuration is coded as number digits, to represent their number in each section of a single root in an occluso-apical direction. weine (43) was the first to start classification by producing four configurations for the root canals course in a single root, see figure (2). figure (2): root canal configurations from type i to type iv, (43). vertucci and williams (44) identified more complex forms of root canal systems to add eight root canal configurations in the literature, see figure (3). j bagh college dentistry vol. 33(4), december 2021 root and root canal morphology 11 thereafter, sert and bayirli (45) described fourteen additional even more complex configurations to complement that was described by vertucci, see figure (4). figure (3): root canal configurations from type i to type viii, (44). figure (4): root canal configurations from type ix to type xxiii, (45). 4.2. new systems for root canal classification (formulation systems) the simple idea behind these systems is to represent the root and root canal configuration of a tooth by coded formula, including symbols and numbers, easily written and identified, these systems were developed for the first time by ahmed et al. (11), with useful additions to this system persisted up to date. 4.2.1. new classification system for root and root canal morphology by ahmed et al. (2017). according to this system (11), tooth number (tn) can be written by using any numbering system (e.g., universal numbering system, palmer notation numbering system, or the fdi world dental federation system). if the tooth cannot be identified using one of the numbering systems (i.e., extracted teeth), then a suitable abbreviation can be used, e.g., maxillary (upper) central incisor (uci). number of roots is added as a superscript before the tooth number (rtn). any division of a root whether in the coronal, middle or apical third will be coded as 2 or more roots. accordingly, a bifurcation is represented as (2tn), and trifurcation is represented as (3tn), and so on. details of roots (rtn r1 r2 ... etc.) in double and multi-rooted teeth are added on the right of the tooth number. when individual roots are fused, a slash ('/') should be added between the initial letters of each root. type of root canal configuration in each root will be identified as a superscript number after the tooth number starting from the orifice (o), through the canal (c), to the foramen (foramina) (f). considering any similar adjacent numbers for a specific root reduced into single number representing both. number of canals before furcation, written as a subscript after tooth number, see figure (5, 7). figure (5): diagrammatic representation of the new classification system. 4.2.2. accessory/auxiliary root canals classification system by ahmed et al. (2018) taking into account the necessity of precise interpreting, and well localizing the accessory/auxiliary root canal ramifications, we cannot go blind with the essential determining role of this characterization in attaining favorable overall final results in our routine practice of endodontic treatment. as it has been reported in many cases that apical divergent morphology is responsible for persistent apical periodontitis and incomplete healing after efficient well-sealed 3d root canal obliteration from the operator's point of view (46). on the other hand, these ramifications may be the answer for many diagnostic questions in confusing cases, giving explanations for lateral radiolucency of unknown origin, or surprising devitalization after root planning especially with the development of j bagh college dentistry vol. 33(4), december 2021 root and root canal morphology 11 new technologies for precise 3d characterization of this complex morphology with ease (46-48). the nomenclature of accessory canals is described by several authors, with many of no clear demarcating lines for separating the many types of these canals. some authors produced their description on angular bases, as for lateral canals meeting the main canal at a right angle, while the accessory canals being at an oblique angle. other modalities depended on spatial location, lateral canals named for those emerging from the trunk of root in the coronal and middle thirds, accessory canals emerging in the apical third more precisely 3.5 mm from the root end, while furcation canals emerge from the floor of the pulp chamber. the term apical delta/ramifications notate divergent fine branching of the accessory canals at the apical end of the root canal with obliteration of the main canal just like a tree branch (45, 49-54). with neglecting the old attentions to classify these canals which was with much of confusion, emphasizing on the new one that gave a nominal notation for the accessory canals in general as a new addition for the new classification system was described by ahmed et al. (14). this system gives you a clear picture about the location of the canal along its course without additional complex information, making it suitable for trainees and researchers communication. in this system or addition, ahmed et al. (14) divided the root into three partitions apical, middle, and coronal (a, m, c), respectively. moreover, they described the course of canal from the orifice opening, canal penetration within the dentinal wall, ending with its foramen on the root surface (a o-ca f) respectively, fused into a single number when they are similar, writing it as a superscript after tooth number(tn) in single-rooted tooth or when the accessory canal located in the floor of the chamber, or after root number(rn) in double/multi-rooted teeth, apical delta notified as (d), when these canals present in more than one-third of the root separate between root divisions by comma(,), adding straight horizontal line among parts of canal course, one canal may have orifice in specific root third with its orifice opens in another third in such a case mention both root sections with a comma in between, see figure (7). 4.2.3. root canal anomaly classification by ahmed and dummer (2018). most classification systems previously added had been going very deep in describing root canal anomalies in a detailed manner with much of complexity, stands against an immediate clear interpretation of them (44, 55-58). this limitation is compensated for with the new addition of classification system described by ahmed and dummer (12), who allow easy simultaneous interpretation of these anomalies along with root and root canal morphology in the same notation. the anomalies described in this system should be related directly to the root canal morphology, affecting the endodontic work. abbreviation for the anomaly added in capital letters between brackets (a) before tooth number, with the subtype if present and identified clinically added as a superscript on the right upper corner (a2). if the anomaly includes fusion between teeth or roots, then slash (/) is added between them, while double slash (//)is added if root canals have inter-canal communications. if the tooth has more than one of the same anomalies, write the number of repetitions on the left side to the tooth anomaly (na), while if the same tooth has more than one different anomaly, then separate between them with comma (a1, a2), see figures (6, 7). figure (6): diagrammatic representation of tooth/root anomalies. figure (7): (a) examples of symbolic representation of the root canal system by ahmed et al. (11), (b) accessory root canals formulations, merged with root canal configuration details in the same formula (14), (c) examples for coding some of the common root canal anomalies (dens evaginatus (de)) (12). j bagh college dentistry vol. 33(4), december 2021 root and root canal morphology 11 4.2.4. application of the new classification system on primary teeth by ahmed et al. (2020) root canal treatment or partial pulpectomy has become part of the routine treatments of primary teeth. to ensure normal physiological resorptive process and exfoliation, or if tooth retention is required for some time, and to optimize these procedures, it is necessary to realize the anatomy of these root canal miniatures, with all associated anomalies and fine communications, just like in permanent teeth (59-63). root canal treatment in primary teeth has challenged with many factors, signing first one which is aberrance from normal morphology specially in the posteriors, as a result of dentin islands formed continuously, in addition to physiologic resorption that may alter the working length, moreover anterior primary teeth normally show additional canals specially in upper canines. on the other hand, pathological factors such as periodontal tissue inflammatory diseases are more complicating their anatomy by altering the normal course of root resorption, which itself is uneven and not predictable (64, 65). the present system or addition (66) sharing nearly the same formula as has been described for permanent teeth by ahmed et al. (11), but with lightening some point differences in writing formula include (1) primary tooth number could be replaced by any simple abbreviation if the exact number could not be identified, (2) physiologic tooth resorption is not included in the formula, but the formula will be changed if the resorption altered the anatomy during the course of treatment, (3) accessory canals are usually coded as in permanent, but should be omitted from the formula in specific conditions when there is an extensive resorptive process, or tooth is about to exfoliate (67). conclusion the root canal analysis methods, divided into two approaches; clinical and in vitro techniques, with the latter has shown more precise non-subjective readings, on the other hand; clinical methods provide direct diagnostic methods for the clinical cases on the chair-side. the classification systems pointed to in the present literature, has been reviewed, beginning with the oldest trials to represent the root canal systems in diagrams, according to the angulation degree, or simply by latin numbers or english letters, reaching to the most recent systems, which persist with continuous editions up to date. these new systems could briefly describe the root and root canal’s internal and external details in a small formulation, without confusion and in an easily communicated manner, highly recommended specially for students, teachers, and researchers. conflict of interest: none. references 1. shrestha a, marla v, shrestha s, maharjan ik. developmental anomalies affecting the morphology of teeth–a review. rsbo. 2015;12(1):68-78. 2. luder hu. malformations of the tooth root in humans. front. physiol.. 2015;6:307. 3. jafarzadeh h, abbott pv. dilaceration: review of an endodontic challenge. j endod. 2007;33(9):1025-30. 4. kremeier k, hülsmann m. fusion and gemination of teeth: review of the literature, treatment considerations, and report of cases. endo. 2007;1 (2.) 5. alani a, bishop k. dens invaginatus. part 1: 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yang j, fan b. morphometric study of the apical anatomy of c-shaped root canal systems in mandibular second molars. int endod j. 2007;40(4):23946. 50. de deus qd. frequency, location, and direction of the lateral, secondary, and accessory canals. j endod. 1975;1(11):361-6. 51. american association of endodontics (2016) glossary of terms. 52. al‐ qudah a, awawdeh l. root canal morphology of mandibular incisors in a jordanian population. int endod j. 2006;39(11):873-7. 53. çalişkan mk ,pehlivan y, sepetçioğlu f, türkün m, tuncer sş. root canal morphology of human permanent teeth in a turkish population. j endod. 1995;21(4):200-4. 54. green d. a stereo-binocular microscopic study of the root apices and surrounding areas of 100 mandibular molars: preliminary study. oral surg oral med oral pathol. 1955;8(12):1298-304. 55. yoshiuchi y., yokochi k. studies on the anatomical forms of the pulp cavities with new method of vaccum inje ction,. shika kiso igakkai zasshi. 1972;14(2):156-85. 56. yoshida h, yakushiji m, sugihara a, tanaka k, taguchi m. [accesory canals at floor of the pulp chamber of primary molars (author's transl)]. shikwa gakuho. 1975;75(3):580-5. 57. versiani m.a. o-zr. root canal anatomy: implications in biofilm disinfection. springer series on biofilms ed. chávez de paz l. sc, kishen a., editor. berlin, heidelberg.: springer; 2015. 58. satoru matsunaga ys, hideaki kinoshita, masashi yamada, akinobu usami, yuichi tamatsu, shinichi abe . morphologic classification of root canals and incidence of accessory canals in maxillary first molar palatal roots: three-dimensional observation and measurements using micro-ct. j hard tissue biol. 2014;23(3):329-34. 59. ozcan g, sekerci a, kocoglu f. c-shaped mandibular primary first molar diagnosed with cone beam computed tomography: a novel case report and literature review of primary molars' root canal systems. j indian soc pedod prev dent. 2016;34 (4:)392-404. 60. neboda c, anthonappa rp, king nm. preliminary investigation of the variations in root canal morphology of hypomineralised second primary molars. int j paediatr dent. 2018;28(3):310-8. 61. ahmed h. anatomical challenges, electronic working length determination and current developments in root canal preparation of primary molar teeth. int endod j. 2013;46(11):1011-22. 62. el hachem c, kaloustian m, nehme w, ghosn n, abou chedid j. three-dimensional modeling and measurements of root canal anatomy in second primary mandibular molars: a case series micro ct study. eur arch paediatr dent. 2019;20(5):457-65. 63. reddy nv, daneswari v, patil r, meghana b, reddy a, niharika p. three-dimensional assessment of root canal morphology of human deciduous molars using cone beam computed tomography: an in vitro study. int j pedod rehabil. 2018;3(1):36. 64. rimondini l, baroni c. morphologic criteria for root canal treatment of primary molars undergoing resorption. dent traumatol. 1995;11(3):136-41. 65. waterhouse pj wj, camp jh, fuks ab, pathways of the pulp, 10th ed., hargreaves k cs, editor: st. louis, mosby elsevier, 2011, 808–57 p. 66. ahmed hma, musale pk ,el shahawy oi, dummer pmh. application of a new system for classifying tooth, root and canal morphology in the primary dentition. int endod j. 2020;53(1):27-35. 67. ahmed hm, versiani ma, de-deus g, dummer pm, new proposal for classifying root and root canal morphology, in: versiani, m, basrani, b and sousa-neto, md eds., the root canal anatomy in permanent dentition, springer international publishing, 2018, pp. 4756. الخالصة مختلف على نطاق واسع وغير متوقع، وكثيرا" ما يتم ربطه بالمشاكل السريرية، مما يؤثر بالتالي االهداف: تشكيل تجاويف الجذور اللبية في االسنان بشكل مباشر على نتائج العالجات الجذرية. ر " هي المصدpubmed: فقط الدراسات المنشورة الكترونيا" تم البحث عنها ضمن هذا االستعراض. المصادر: بوابة البحث االللكترونية "البيانات ".root ,"“canal” ,“morphology”" ,classificationالوحيد الذي تم اعتماده للبحث عن مفردات االستعراض، و ذلك باستخدام الكلمات الداللية " ي الكتابة.فاختيار الدراسة: تم اختيار الدراسات المكتبية والبحوث االصيلة، التي لها عالقة مباشرة بموضوع االستعراض، لتكون مصادرا" معتمدة غير متأثرة ةاالستنتاجات: الدراسات المعنية بتحليل شكل التجاويف اللبية للجذور تقسم الى قسمين؛ سرسرية ومختبرية، االخيرة اظهرت قراءات أكثر دق نيفية التي تم االنظمة التص باسلوب الباحث، بينما بالمقابل، الطرق السريرية تعتبر وسيلة تشخيصية مباشرة للحاالت السريرية على كرسي العالج. ذور، او جاستعراضها في الموضوع الحالي، تبدأ مع اقدم المحاوالت لتمثيل انظمة التجاويف اللبية على شكل مخططات، او بناءا" على درجة التواء ال افات مستمرة ترميزية مفصلة، والتي ال تزال مع اضترمز باحرف باللغة الالتينية او االنكليزية، انتهاءا" مع احدث االنظمة التصنيفية التي تستخدم صيغة الى هذا التاريخ. articles published by journal of baghdad college of dentistry is licensed under a creative commons attribution 4.0 international license. j bagh college dentistry vol. 26(1), march 2014 a comparative study restorative dentistry 49 a comparative study to evaluate the shear bond strength of different resin sealers to dentin (an in vitro study) samar abdul hamed, b.d.s., m.sc. (1) majida al-hashimi, b.d.s., m.sc. (2) abstract background: one of the major problems in endodontics is micro-leakage of root canal fillings which might contribute to the failure of endodontic treatment. to avoid this problem, a variety of sealers have been tested. the objective of this, in vitro, study was to evaluate the shear bond strength of four resin based sealers (ah plus, silver free ah26, realseal se and perma evolution permanent root canal filling material) to dentin. materials and methods: forty non-carious extracted lower premolars were used. the 2mm of the occlusal surfaces of teeth were sectioned, to expose the dentin surface. the exposed dentin surfaces of teeth were washed with 5ml of 2.5% naocl solution followed by 5ml of 17 % edta then rinsed by deionized water to remove the smear layer. the teeth were divided into four groups according to the type of sealer used: group a: silver free ah26, group b: ah plus., group c: realseal se, group d: perma evolution. polyethylene tube cylinders (4mm internal diameter & 5mm length) were fixed on the dentin surfaces. then freshly mixed sealers were poured into the tubes and allowed to bench set for two hours and were stored at 100% humidity and 37˚c for one week. with an instron machine, the shear bond strength between the tested sealers and the dentin, in mpa, was measured. statistical analysis was carried out using the one-way anova and student’s t-tests. results: perma evolution scored the highest mean value of sheer bond strength, being 3.343 mpa followed by the ah plus (2.786 mpa) and ah26 (2.149 mpa). while the realseal scored the lowest mean value of sheer bond strength, which was (1.831 mpa). anova test results showed a highly statistically significant difference. student's t test results revealed significant differences between all the compared groups, except one paired group had a non-significant difference in the shear bond strength which was between the ah plus and perma evolution groups (p>0.05). conclusions: the results of this study pointed to perma evolution which scored the highest sheer bond strength between the tested sealers. key words: sheer bond strength, perma evolution, endodontic sealers. (j bagh coll dentistry 2014; 26(1):49-52). introduction it is well known that the main objective of root canal treatment is the complete seal of the prepared canal system with a root canal sealer in conjunction with a suitable core material. root canal sealers are intended to fili the irregularities between the dentinal walls and the core material, as well as, the accessory and lateral canals (1). the three dimensional root canal obturation and the adequate coronal restoration are important barriers that prevent the infection or reinfection of the periapex. it has been established that microleakage of root canal fillings might contribute to the failure of endodontic treatment. to avoid this problem, a variety of sealers has been tested in combination with gutta-percha for root canal obturation (2). gutta-percha is the most commonly used root canal obturation material, but the resin filling materials have been steadily gained popularity and are now accepted as root canal filling materials (3). sealers based on epoxy resins afford very good physical properties and ensure adequate biological performance. an acceptable apical sealing has been found with epoxy resin based sealers (2). the sealers used in this study are silver free ah26, ah plus (dentsply, germany), realseal se (1)assistant lecturer. conservative department, college of dentistry, university of baghdad. (2)professor. conservative department, college of dentistry, university of baghdad. (epiphany tm, pentron clinical technologies, wailingford, ct, usa) and perma evolution (permanent root canal filling material based on epoxy resin, becht, germany); it fulfills the requirements of en iso 6876:2002 for dental root canal sealing materials with working time of 15 minutes and a setting time of 24 hours (4). the purpose of the study was to evaluate the shear bond strength of four resin based sealers (ah plus, silver free ah26, realseal se and perma evolution, the new permanent root canal filling material) to dentin. materials and methods forty non-carious extracted lower premolars, obtained from the orthodontic department, college of dentistry, university of baghdad, were used in this study. to facilitate the grasping and control of the samples, acrylic blocks were constructed using cold-cure acrylic resin, which was mixed and poured into a stainless steel cylindrical mould lubricated with vaseline. then the teeth were embedded in a freshly mixed acrylic resin using a dental surveyor to position the long axis of the tooth parallel to that of the stainless steel mould leaving only 2 mm of the occlusal surface that projected above the acrylic level (5). the 2mm of the occlusal surfaces of teeth were sectioned, using a diamond disc bur with a straight handpiece and water coolant, to j bagh college dentistry vol. 26(1), march 2014 a comparative study restorative dentistry 50 expose the dentin surface. the exposed dentin surfaces of teeth were washed with 5ml of 2.5% naocl solution followed by 5ml of 17 % edta then rinsed by deionized water to remove the smear layer (6). the forty samples were divided into four groups, (10 specimens each), according to the type of the sealer used:  group a: silver free ah26  group b: ah plus.  gloup c: realseal se.  group d: perma evolution. an adhesive teflon tape with a hole respect to the diameter of the polyethylene tube cylinder's (4mm internal diameter) was fixed on the dentin surfaces leaving a predetermined contact area. the 5mm length of polyethylene tube was fixed to the dentin surface. the freshly mixed sealers were carefully poured into the tubes, that held in contact with the exposed dentin perpendicular to its surface then a glass cover slide placed over the sealer filled tubes, with a 400 g weight (7). all the sealer filled cylinders were allowed to bench set for two hours to ensure that the initial setting reaction was taken place), then the specimens were stored at 100% humidity and 37˚c for one (8). the shear bond strength between the tested sealers and the dentin were measured with the universal testing machine (instron machine), a knife edge rod, with a cross head speed of 0.5mm/min, was used to load the specimens until bond failure. the chisel end of the rod was positioned as close as possible to the interface between the dentin surface and the tested sealer; then the specimens were stressed to failure. the force was recorded in kilograms which have been transferred to newton's; then divided by the surface area (12.56 mm2) to obtain the shear bond strength, calculated in mpa (6). sbs = f/s.a s.a = r2.π π = 3.14 sbs shear bond strength. f – force. s.asurface area. r radius = 2mm. the recorded results were statistically analyzed by: 1. descriptive statistics which included the mean, sd, minimum and maximum values of the shear bond strength in mpa. 2. inferential statistics (the difference among groups were examined by the analysis of variance test (anova) and the difference between each two groups was examined by the student's t-test). results the summary of the mean and the standard deviation (sd) with the minimum, maximum values of the sheer bond strength of the different resin sealers (ah plus, silver free ah26, realseal se and perma evolution permanent root canal filling material) to dentin are compiled in table 1 and figure 1. table 1: descriptive statistics results of shear bond strength of sealers to dentin in mpa. tested groups min. max. mean s.d. a 1.671 2.547 2.149 0.303 b 2.468 3.025 2.786 0.165 c 1.433 2.229 1.831 0.241 d 2.229 4.458 3.343 0.715 a=ah26, b=ah plus, c=real seal, d=perma evolution from the results which are shown in table 1 and figure 1, it is clear that the perma evolution scored the highest mean value of sheer bond strength, being 3.343 mpa followed by the ah plus (2.786 mpa) and ah26 (2.149 mpa). while the realseal scored the lowest mean value of sheer bond strength, which was (1.831 mpa). statistical analysis of the data by using the analysis of variance (anova) test was done. the results showed that there was a highly statistically significant difference (p < 0.000) between all the groups which were tested in this research, table 2. table 2: the anova test results. s.o.v ss df ms f-test p-value between 8.154 3 2.718 13.194 0.000 hs* within 4.132 20 0.206 total 12.286 23 * highly significant. since the anova test results showed a highly significant difference the student's t-test was performed regarding the shear bond strength of the tested sealers to dentin, table 3. table 3. student's t-test results sig pvalue ttest compared groups s* 0.024 3.191 a vs. b s 0.020 3.381 a vs. c s 0.015 3.630 a vs. d s 0.002 5.946 b vs. c ns** 0.102 1.996 b vs. d s 0.003 5.451 c vs. d *p<0.05 significant, **p>0.05 non significant j bagh college dentistry vol. 26(1), march 2014 a comparative study restorative dentistry 51 the results, concerning the shear bond strength of the used sealers to dentin, revealed significant differences between all the compared groups (p<0.05); except one paired group had a nonsignificant difference in the shear bond strength which was between the ah plus and perma evolution groups (p>0.05). discussion three-dimensional sealing of the root canal systems is one of the important goals of endodontic therapy by preventing the reinfection of the canal and, therefore; preserving the healthy status of the periapical tissues. since the appropriate selection of a sealer may influence the final clinical outcome; the biological and mechanical properties of different endodontic sealers have been extensively investigated. the root canal sealers are subject to international standards and national regulations regarding their physical properties, but there is no consensus among researchers on adhesion testing, in other words, these tests are not standardized (9). the methods to measure shear strength are the simplest, most effective and reproducible. they were developed to evaluate and measure the bonding of dentin to endodontic sealers. although various types of sealers have been used, the development of adhesive, resin-based filling material with better properties could increase the rate of endodontic success (10). in this study, flat surfaces of dentin were used to measure the sheer bond strength of the selected sealers to the dentin; the advantage of using flat surfaces is the ease of specimen standardization, which allows comparing the bond strength of root canal sealers to dentin. the load was applied perpendicular to the direction of the dentin tubules, since it simulates the real forces that act inside the root canal system. in the present study, the mean sheer bond strength of the three evaluated sealers to dentin ranged from 1.433 to 4.458 mpa; perma evolution being the best with a mean sheer bond strength of 3.343 ± 0.715 mpa. the ingredients of this new permanent root filling material are 4-[2(4-hydroxyphenyl)propan-2-yl]phenolepichlorodineresin, alkylglycidyl ether, diphenylolpropan-diglycidyl ether, polyalkoxyalkylamine-copolymer, 5-amino-1,3,3 trimethylcyclohexanmethylamin, aqua, barium sulfate, tri-calciumphosphate, nanodispers silicon dioxide, polyhexamethylene biguanideshydrochloride. therefore, the permanent root filling material perma evolution combines epoxide chemical characteristics. it comes with integrated microcapsules containing a new reactive adhesive to make the two-component material more resilient and tight. fine cracks caused by physical strength are reliably sealed even after the material has set; consequently, for the mentioned reasons it might have the highest mean of sheer bond strength among the tested materials (4). the next highest adhesion scores were obtained with ah plus which agrees with the results reported by haragushiku et al.(11); when root dentin was treated with er:yag laser and 17% edtac. the resin-based sealers possess different adhesive behaviors, since they depend on the type of treatment of root canal walls. ah plus sealer showed the higher bond strength in smear layer removed surfaces; since pretreatment with edta/naocl affected bond strength of them. during chemomechanical preparation of root canals, smear layer is formed on the dentin walls. treatment of the intra-radicular dentin with chemicals that remove the smear layer, such as, ethylene-diamine-tetra-acetic acid (edta) and sodium hypochlorite, may affect bond strength. it is important to emphasize that due to its resin nature, flow and long setting time, ah plus sealer penetrates deeper into the surface microirregularities, as well inside the lateral root canals (12). as a conclusion; perma evolution being the best; since having the highest mean of sheer bond strength of 3.343 ± 0.715 mpa. this permanent root filling material combines epoxide chemical characteristics because it contains a new reactive adhesive which makes the two-component material more resilient and tight. fine cracks caused by physical strength are reliably sealed even after the material has set. references 1. yigit dh, gencolu n. evaluation of resin/silicone based root canal sealers. part 1: physical properties. j nanomaterials and biostructures 2012; 7(1): 107-15. 2. drukteinis s, peciuliene v, maneliene r, bendinskaite r: in vitro study of microbial leakage in roots filled with endo rez sealer endo rez points and ah plus sealer/conventional gutta-percha pointes. stomatologija, baltic dental and maxillofacial j 2009; 11: 21-5. 3. garcia lf. naves lz, consani s, correr-sobrinho l, pires-de-sousa fcp. apical obturation quality of epiphany/resilon root canal filling system. braz j oral sci 2009; 8(3): 132-6. 4. alfred becht gmbh, carl-zeiss-str. 16, • d-77656 offenburg ec material safety data sheet according to 91/155/ewg 5. al-ani ra. evaluating the effect of collagen removal on shear bond strength of two dentin adhesive system (using naoci treatment). master thesis. department j bagh college dentistry vol. 26(1), march 2014 a comparative study restorative dentistry 52 of conservative dentistry, college of dentistry, university of baghdad, 2004. 6. al-azzarwi ak, yasin sah. a comparative study to evaluate the effect of immediate versus delayed dowel space preparation on the apical seal of epiphany obturation system with different obturation techniques (an in vitro study). j bagh college dentistry 2009; 21(3): 41-6. 7. al-ani ma, al-hashimi mk. shear bond strength of endodontic sealers to dentin and gutta-pereha (in vitro study). master thesis. department of conservative dentistry, college of dentistry, university of baghdad, 2007. 8. tagger m, tagger e, tjan ahl, bakland l. measurement of adhesion of endodontic sealers to dentin. j endod 2002; 28(5): 35i-4. 9. bojar w, czarnecka b, prylinski m, walory j. shear bond strength of epoxy resin-based endodontic sealers to bovine dentin after ozone application. acta bioengineering and biomechanics 2009; 11(3): 41-5. 10. tagger m, tagger e, tjan ah, bakland lk. shearing bond strength of endodontic sealers to gutta-percha. j endod 2003; 29(3):191-3. 11. haragushiku ga, sousa-neto md, silva-sousa yt, alfredo e, silva sc, silva rg. adhesion of endodontic sealers to human root dentine submitted to different surface treatments. photomed laser surg 2010; 28(3): 405-10. 12. eldeniz au, erdemir a, belli s. shear bond strength of three resin based sealers to dentin with & without the smear layer. joe 2005; 31(4): 293-6. figure 1: the mean values of shear bond strength of the tested sealers to dentin in mpa. http://www.ncbi.nlm.nih.gov/pubmed?term=tagger%20m%5bauthor%5d&cauthor=true&cauthor_uid=12669879 http://www.ncbi.nlm.nih.gov/pubmed?term=tagger%20e%5bauthor%5d&cauthor=true&cauthor_uid=12669879 http://www.ncbi.nlm.nih.gov/pubmed?term=tjan%20ah%5bauthor%5d&cauthor=true&cauthor_uid=12669879 http://www.ncbi.nlm.nih.gov/pubmed?term=bakland%20lk%5bauthor%5d&cauthor=true&cauthor_uid=12669879 http://www.ncbi.nlm.nih.gov/pubmed?term=haragushiku%20ga%5bauthor%5d&cauthor=true&cauthor_uid=20438354 http://www.ncbi.nlm.nih.gov/pubmed?term=sousa-neto%20md%5bauthor%5d&cauthor=true&cauthor_uid=20438354 http://www.ncbi.nlm.nih.gov/pubmed?term=silva-sousa%20yt%5bauthor%5d&cauthor=true&cauthor_uid=20438354 http://www.ncbi.nlm.nih.gov/pubmed?term=silva-sousa%20yt%5bauthor%5d&cauthor=true&cauthor_uid=20438354 http://www.ncbi.nlm.nih.gov/pubmed?term=alfredo%20e%5bauthor%5d&cauthor=true&cauthor_uid=20438354 http://www.ncbi.nlm.nih.gov/pubmed?term=silva%20sc%5bauthor%5d&cauthor=true&cauthor_uid=20438354 http://www.ncbi.nlm.nih.gov/pubmed?term=silva%20rg%5bauthor%5d&cauthor=true&cauthor_uid=20438354 mushtaq final.doc j bagh college dentistry vol. 26(2), june 2014 oral manifestations, oral diagnosis 87 oral manifestations, microbial study and salivary iga study in asthmatic patients receiving prednisolone mushtaq t. ibraheem, b.d.s. (1) fawaz d. al-aswad, b.d.s., m.sc., ph.d. (2) abstract background: asthma is a disease of the airways characterized by chronic inflammation associated with airway hyper-responsiveness and airway wall remodeling. aims of the study: the aims of this study was to determine the prevalence of oral manifestations , identify different microorganism from oral micro flora and determination of salivary iga and salivary flow rate in asthmatic patients taking different dose of prednisolone in comparison with control group. subjects, materials and methods: the study included 17 patients under treatment with prednisolone (10-20 mg),15 patients take (20-30 mg) of prednisolone and other 18 patients take (30 – 40mg) of prednisolone, and 25 healthy control group (10 male and 15 female). results : the most frequent oral manifestations in asthmatic patients on prednisolone was burning mouth syndrome, then dry mouth, tooth erosion and white coated tongue and decreased in salivary flow rate. high prevalence of staphylococcus aureus , staphylococcus epidermidis , streptococcus viridians and candida albicans in patients with asthma and difference in oral microbial isolation between asthmatic patients take different dose of prednisolone and healthy control.the level of salivary iga in asthmatic patients treated with prednisolone less than healthy control. conclusions: the findings of this study show an obvious difference in the prevalence of oral manifestation and some micro-organisms between patients with asthma and healthy control. decrease of iga and salivary flow rate in patients with asthma as compared to healthy control. key words: asthma, prednisolone, oral manifestations, micro-organisms and salivary iga. (j bagh coll dentistry 2014; 26(2): 87-93). introduction asthma is a syndrome characterized by airflow obstruction that varies markedly, both spontaneously and with treatment. asthmatics harbor a special type of inflammation in the airways that makes them more responsive than non-asthmatics to a wide range of triggers, leading to excessive narrowing with consequent reduced airflow and symptomatic wheezing and dyspnea. narrowing of the airways is usually reversible, but in some patients with chronic asthma there may be an element of irreversible airflow obstruction (1). typical symptoms include recurrent episodes of wheeze, chest tightness, breathlessness and cough. commonly, asthma is mistaken for a cold or chest infection that is failing to resolve (e.g. after more than 10 days). classical precipitants include exercise, particularly in cold weather, exposure to airborne allergens or pollutants, and viral upper respiratory tract infections. wheeze apart, there is often little to find on examination. an inspection for nasal polyps and eczema should be performed (2). the asthmatic patients had more gingival inflammation , periodontal disease and dental caries, on the other hand low salivary secretion rate and salivary total immunoglobulin a (iga) this is important in the development of oral candidiasis (3). (1) m.sc. student, department of oral diagnosis, college of dentistry, university of baghdad. (2) assistant professor, department of oral diagnosis, college of dentistry, university of baghdad. the presence of asthma precipitating factors and medication used had a considerable effect on the probability of having symptoms of oral manifestations when diseases compared to healthy individuals therefore asthmatic patients reported more symptoms (dry mouth, sore mouth, halitosis, tempromandibular joint (tmj) disorder and increase dental caries (4). the cornerstone of maintenance therapy in all but mild intermittent asthma is scheduled administration of inhaled corticosteroids. longacting and short-acting bronchodilators are added for additional symptomatic control as needed. leukotriene inhibitors have been shown to be effective adjuncts in maintenance therapy but do not replace corticosteroids. theophylline preparations may have additional beneficial effects in some patients, but the narrow therapeutic window and modest efficacy of these preparations limit their value (5). systemic corticosteroids reduce the inflammatory response and hasten the resolution of exacerbations. they should be administered to all patients experiencing an acute severe attack. they can usually be administered orally as prednisolone, but intravenous hydrocortisone may be given in patients who are vomiting or unable to swallow. prednisolone therapy (usually administered as a single daily dose in the morning) should be prescribed in the lowest amount necessary to control symptoms. patients on long-term oral corticosteroids (> 3 months) or j bagh college dentistry vol. 26(2), june 2014 oral manifestations, oral diagnosis 88 receiving more than three or four courses per year will be at risk of systemic side effects (2,1). corticosteroid administration can be associated with impairment of host immune responses, t lymphocyte, macrophage, and granulocyte function can be impaired leading to increased susceptibility to infection with opportunistic pathogens. bacterial pathogens including staphylococcus aureus (s. aureus), gram negative (g-ve) organisms (6). materials and methods sample seventeen patients under treatment with prednisolone (10-20 mg) ,fifteen patients take (20-30 mg) of prednisolone and other eighteen patients take (30 – 40mg) of prednisolone, and twenty five healthy control group with no sign and symptom of any systemic disease and age, sex match with patient groups .they were examined from the period (11/20124/ 2013). exclusion criteria: -newly diagnosed patients not receiving chemotherapy. patients received radiotherapy. relapsed patients on second line treatment. patients with severe periodontal disease. any other systemic disease. method of examination oral examination all the patients examined by a single examiner, under standardized conditions; the oral cavity examined in an artificial light by using a mouth mirror. the procedure of examination of oral soft tissue was done in sequence according to directions suggested by the w.h.o. (1987). the oral manifestations were designed according to the following results: aburning mouth sensation: the diagnostic criteria for burning mouth syndrome in this study was: pain in the mouth present daily and persisting for most of the day, oral mucosa is of normal appearance, local and systemic diseases have been exclude (9) bdry mouth: was diagnosed according to the anamnesis below: does your mouth feel dry? do you experience any difficulties in chewing dry foods? do you experience any difficulties in swallowing dry foods? are you aware of any recent increase in the frequency of liquid intake? c -white coated tongue (wct): appear as white areas adherent to the dorsum of the tongue, upon removal with cotton applicator they revealed an erythematous mucosa (7). d -tooth erosion (te): irreversible loss of tooth structure due to chemical dissolution by acids not of bacterial origin, erosion is found initially in the enamel and, if unchecked, may proceed to the underlying dentin (8). identification of bacteria all the bacteria isolated was identified by colony appearance. biochemical characteristics. gram's stain. immunological analysis the level of salivary iga in saliva was estimated using demeditec secretary iga elisa (dexk276). results distribution of studied samples according to the gender the study sample consist of 50 asthmatic patients of both sex, there were 18(36%) males and 32(64%) females. asthmatic patients were divided into three groups 17 patients take (1020 mg) prednisolone of both genders, 5(29.4%) were males and 12 (70.6%) were females,15 patients take (2030 mg) prednisolone 7(46.7%) were males and 8 (53.3%) were females and 18 patients take (3040 mg) prednisolone 6(33.3%) were males and 12(66.7%) were females as seen in table (1) . on the other hand the second group is control group similar in respect to age and gender. ethnic matched with asthmatic group, they were 25 healthy looking individuals, who have no history or clinic evidence of any disease or obvious abnormalities. oral manifestation aburning mouth syndrome the number of patients with asthma take (10 20 mg) of prednisolone which have burning sensation are 11(64.7%) and in patients with asthma take (2030 mg) were 10(66.7%), while the patients take (30-40mg) have13(72.2%)and all these study groups showed highly significant differences with control group and non significant differences between each other, as appear in figure (1). bdry mouth there were highly significant differences between asthmatic patients and control group and no significant relationship between the study groups as shows in figure (1). dry mouth was present in 8(47.1%) asthmatic patients on (1020 mg), in 9(60%) asthmatic patients on (2030 mg) and in 11(61.1%) asthmatic patients on (3040 mg), while not present in control group. cwhite coated tongue j bagh college dentistry vol. 26(2), june 2014 oral manifestations, oral diagnosis 89 highly significant differences between asthmatic patients and control group and no significant differences between the studied groups were shown. white coated tongue was present in 2(11.8%) asthmatic patients on (1020 mg), in 8(53.3%) asthmatic patients take (2030 mg) and in 9(50%) asthmatic patients on (3040 mg), while not present in control group as showed in figure (1). dteeth erosion out of 17 patients suffering from asthma and take (1020 mg) of prednisolone 3(17.6%),were complaining from teeth erosion, while 7(46.7%) in the patients on (2030 mg) and patients on (30 40 mg) have 9(50%) statistically highly significant differences with control group and no significant differences between each other, as appear in figure (1). microbiology aerobic bacteria: no significant difference has been found between asthmatic patients and control group except for s. epidermidis, neisseria and streptococcus viridian as shown in figure (2). anaerobic bacteria: no significant difference has been found between asthmatic patients and control group regarding anaerobic microorganism as shown in figure (3). candida albicans: a significant difference was established between asthmatic patients and control group as shown in figure (4). salivary iga: the iga in asthmatic patients with different dose of prednisolone and healthy control individuals with a mean and sd and minimum and maximum values were evident, the lowest value being related to patients treated with (30-40 mg) of prednisolone (173.44 µg/ml) and the asthmatic patients on (2030mg) of prednisolone (178.25 µg/ml) followed by that scored by the asthmatic patients on (1020mg) of prednisolone (226.51 µg/ml) ,while the mean iga value for control group (236.29 µg/ml) as appear in table (2) and table (3). salivary flow rate : all doses of treatment were compared against the control groups, with the greatest value of mean at salivary flow rate parameter was in control groups (2.54), then (1.69) in asthmatic patients on (10-20mg) of prednisolone ,(1.53) in asthmatic patients on (2030mg) of prednisolone and finally (1.46) in asthmatic patients on (20-30mg). the lowest value of standard division was in control groups (0.52), then (0.55) in asthmatic patients on (3040mg) of prednisolon, (0.64) in asthmatic patient take (20-30mg) of prednisolone and finally (0.79) in asthmatic patient take (20-30mg) as appear in table (4) and table (5). discussion asthma is a chronic inflammatory disorder of the airways. no single histopathology feature is pathognomonic but common findings include inflammatory cell infiltration with eosinophils, neutrophils, and lymphocytes (especially t lymphocytes); goblet cell hyperplasia, sometimes with plugging of small airways with thick mucus; collagen deposition beneath the basement membrane; hypertrophy of bronchial smooth muscle; airway edema; mast cell activation; and denudation of airway epithelium. this airway inflammation underlies disease chronicity and contributes to airway hyper-responsiveness and, airflow limitation (9). oral manifestations the oral manifestations may occasionally occur before the onset of asthma, be present during the disease process or persist even after the disease has resolved, while at other times the oral manifestations are caused by systemic alterations secondary to asthma. the presence of asthma precipitating factors and medication used had a considerable effect on the probability of having symptoms of oral manifestations (4). differences between this study and other studies is not surprising, taking into consideration the lack of the objective criteria, demographic, ethnic, epidemiological factors, all of these make the comparison of this type of the study and others is difficult. the use of medication other than for asthma was also a significant risk factor for the prevalence of other symptoms of oral diseases. this was more common among asthmatics than controls. the medications used are not known exactly, but the most likely explanation is the comorbidity of allergic diseases. asthmatics often tend to use medications for other allergic conditions, such as rhinitis, conjunctivitis, and dermatitis. the most frequent oral manifestations was bms in patients with asthma as compared to healthy control this agreed with laurikainen and kuusisto (10).this may be explained by the use of corticosteroids may sometimes increase the risk of candida infections in mouth and the oral candidiasis is usually associated with a burning sensation in the mouth or on the tongue (11). the poly-pharmacy is a true risk factor for oral dryness. dry mouth or xerostomia is defined as an overall reduction of salivary output. it is an adverse effect observed with use of corticosteroids (12). j bagh college dentistry vol. 26(2), june 2014 oral manifestations, oral diagnosis 90 the present study showed that the prevalence of dry mouth is highly in asthma as compared to healthy control group this similar laurikainen (13). they were no reports available about the effects of corticosteroids on the function of the salivary glands but in the lungs one of the effects of corticosteroids is decreased mucous secretion (14). regarding white coated tongue, the prevalence of these lesions in asthmatic patients were high as compared to healthy control group this got the same result with fukushima, et al. (15). again this may explained by the patients who are treated with corticosteroids show a higher level of salivary glucose than the control group. this higher glucose concentration can also promote growth, proliferation and adhesion of candida to the oral mucosal cells (16). there were obvious differences between the level of erosion in asthmatic patient than non asthmatic patient the explanation of the prevalence of dental erosion among asthmatic patients thus reducing the modifying and protective effects of saliva; bronchodilator drug relax smooth muscle which affect levels lower oesophageal sphincter in addition to bronchus and thereby potentiate gasrooesophageal reflex which result in tooth erosion (17). oral microbiology many of the normal flora isolated in this study are either pathogenic or opportunistic .pathogens like s. aureus which is potential pathogens, and it is already a cause of many bacterial disease in humans, the present study showed increased in the isolation of s. aureus in asthmatic patients as compared to healthy control with statistically non significant relationship. however, s.aureus have caused infections in asthmatic patients treated with corticosteroids (18). the present study showed increase in the isolation of s.epidermidis as compared to the healthy control due to continuous use of antibiotics in hospitals (19). alpha-hemolytic streptococcus viridans illustrated hs relationship as compared with the healthy control and this agreed with klein, et al. (20) that may be partially explained by the immunodeficiency caused by glucocorticosteroid treatment. difference between micro-flora of asthmatic patients as compared to healthy control, is not surprising taking in the consideration host defense mechanism and drug used attributed to these differences. however, g-ve organisms have caused infections in asthmatic patients treated with corticosteroids (21). ulrich (22) stated that a systemic proliferation of un-encapsulated neisseria strains may occur in several immunocompromised hosts . corynebaoterium is a genus of g+ve, rod-shaped bacteria. they are widely distributed in nature and are mostly innocuous (23). corynebaoterium diphtheria strains constitute part of the normal flora, but certain strains once infected by a phage can cause disease, particularly in a compromised (unhealthy) host, up to our knowledge, this study was the first study isolated corynbacterium diphtheriod from asthmatic patients, therefore no explanation could be found. klebsiella, e-coli and proteus were isolated in small no. from asthmatic patients made them statistically non advisable, therefore no explanation could offer. the anaerobic g+ve cocci comprise a diverse group of organisms. the majority of those associated with humans were formerly included peptostreptococcus (24). they are commensal organisms in humans, living predominantly in the mouth. under immunosuppressed these organisms can become pathogenic, as well as septicemic, harming their host. peptostreptococcus can cause brain, liver, breast, and lung abscesses, as well as generalized necrotizing soft tissue infections. they participate in mixed anaerobic infections, a term which is used to describe infections that are caused by multiple bacteria that do not require or may even be harmed by oxygen (25). again the isolation is more in asthmatic patients as compared to healthy individuals, this could be explained by the fact that the immunological aspect which reflect on the composition of normal flora by low level of circulating and secreting antibodies that may cross react with pathogens. the results of c.albicanus is ignificant as compared with control group and this result agreed with fukushima,et al. (15). this explained by the patients who are treated with corticosteroids show a higher level of salivary glucose than the control group (16). salivary iga this study showed that asthmatic patients treated with prednisolone at different doses illustrated that salivary iga was different between healthy controls and asthmatic patients. the salivary iga asthmatic patients was significantly lower than that in the control group this similar with fukushima et al. (15) , they suggested that steroids have the potential to reduce salivary total iga and that asthmatic patients with lower salivary total iga tend to suffer oral candidiasis. j bagh college dentistry vol. 26(2), june 2014 oral manifestations, oral diagnosis 91 on the contrary, mandel et al. (26) have reported no difference between salivary iga levels in asthmatic patients they were on corticosteroids and healthy controls, while blanca et al. (27) disagree with this study found the salivary iga increased in response to corticosteroids, also the children with asthma have iga statistically higher as compared with healthy children (28). mona et al. (29) stated that the severity of asthma is directly correlated with the concentration of salivary siga and also concentration and composition of oral bacterial flora and the low concentration of siga is viewed as a compensating reaction, which nevertheless denotes the immaturity of the protection factors in cases of asthma. referances 1. longo dl, fauci as, kasper dl, bbraunwald e, hauser sl, jameson jl, lozcalzo j. harrison's: principles of internal medicine. 18th ed. mcgraw-hill co.; 2011. 2. colledge nr, walker br, hunter ja, (eds). davidson’s principles and practice of medicine. 21st ed. churchill livingstone: elsevier; 2010. p. 670–8. 3. fukushima c, matsuse h, tomari s, obase y, miyazaki y, shimoda t, kohno s. oral candidiasis associated with inhaled corticosteroid use: comparison of fluticasone and beclomethasone. ann allergy, asthma immun 2003; 90: 646– 51. 4. jaber wf. salivary analysis and oral symptoms in controlled asthmatic patients. 2005; 2(1): 52-68. 5. goldman l, schafer ai, drazen j. goldman's cecil medicine. part 9: respiratory diseases. 24th ed. saunders; 2012. 6. wiest pm, flanigan t, salata ra, shlaes dm, katzman m, lederman mm. serious infectious complications of corticosteroid therapy for copd. chest 1989; 95:1180-84. 7. greenberg, ms, glick, m, ship, ja. burket’s oral medicine.11th ed. india: bc decker inc.; 2008; p. 34. 8. davenport t. signs and symptoms of tooth erosion. http://dentistry.about.com/od/toothmouthconditions/a/t eetherosionsym.htm. 2007. 9. mcphee sj, papadakis ma. current medical diagnosis and treatment. 50th ed. mcgraw-hill co.; 2011. 10. laurikainen k, kuusisto p. comparison of the oral health status and salivary flow rate of asthmatic patients with those of non asthmatic adults-results of a pilot study. allergy 1998; 53: 316-9. 11. laurikainen k, hakama m, haahtela t. asthma and oral health a clinical and epidemiological study 2002. 12. toogood jh. complications of topical steroid therapy for asthma am rev respir dis. 1990; 141: s89–s96. 13. torres sr, peixoto cb, caldas dm, silva eb, akiti t, nucci m, et al. relationship between salivary flow rates and candida counts in subjects with xerostomia. oral surg oral med oral patholoral radiol endod 2002; 93:149–54. 14. barnes pj, pedersen s. efficacy and safety of inhaled steroids in asthma. am rev respir dis 1993; 148:s1 – s26. 15. fukushima c, matsuse h, saeki s, et al. salivary iga and oral candidiasis in asthmatic patients treated with inhaled corticosteroid. j asthma 2005; 42:601–604. 16. khaledh abu-elteen. the influence of dietary carbohydrates on in vitro adherence of four candida species to human buccal epithelial cells. microbial ecology in health and disease 2005; 17: 156-62. 17. barlett dw and smith bgn. the dental relevance of gastric reflux. dent update. 1996; 23(4):205-8. 18. staples dj, geiding dn, decker jl, gordon rs. incidence of infection in systemic lupus erythematosus. arthritis rheum 1974; 17:1-10. 19. blum-menezes doj, bratfich mc, padovezeand ml, moretti. hospital strain colonization by staphylococcus epidermidis. braz j medical and biological res 2009; 42: 294-8. 20. klein nc, go ch, cunha ba. infections associated with steroid use. infect. dis. clin. north am. 2001; 15 (2): 423–32, viii. 21. buchner lh, schneurson ss. clinical and laboratory aspects of listeria monocytogenes infection with a report of 10 cases. am j med 1968; 45: 904-21. 22. ulrich v, heike c. lutz von mu¨ller, donald b, johannes e, and matthias f. bacteremia in an immuno-compromised patient caused by a commensally neisseria meningitides strain harboring the capsule. null locus j clinical microbial 2004; 2898–901. 23. collins md, hoyles l, foster g, falsen e. corynebacterium caspium sp. nov., from a caspian seal (phoca caspica) . int j syst evol microbiol 2004; 54 (pt 3): 925–8. 24. ezaki t, kawamura y, li n , li zy, zhao l, shu s. proposal of the genera anaerococcus gen. nov., peptoniphilus gen. nov. and gallicola gen. nov. for members of the genus peptostreptococcus. int j syst evol microbial 2001; 51:1521–8. 25. mader jt, calhoun j. bone, joint, and necrotizing soft tissue infections. in: baron's medical microbiology (baron s et al., eds.) (4th ed.). univ of texas medical branch. (via ncbi bookshelf) isbn. 1996; 0-9631172-1-1 26. mandel id, barr ce, turgeon l. longitudinal study of parotid saliva in hiv-1 infection. j oral pathol & med 1992; 21:209–13. 27. blanca en, lizbeth ch, rodolfo fr, arturo b, saul ta, vicente cr, juan jism. effect of salmeterol and salmeterol plus beclomethasone on saliva flow and iga in patients with moderate-persistent chronic asthma. ann allergy, asthma, & immun 2001; 87:420– 3. 28. rashkova m, baleva m, toneva n, peneva m, penka p, koprivarova k. secretory immunoglogulin a (siga) in the saliva of children with type 1 diabetes, asthma, systemic health and systemic health but wearing removable orthodontic appliances. ohdmbsc 2009; 8(2): 16-24. 29. olar m, luca r, olar v, effects of oral hygiene upon the quality of breathing in children suffering from bronchial asthma. intern j medic dent 2012; 2 (3):188-94. http://dentistry.about.com/od/toothmouthconditions/a/t j bagh college dentistry vol. 26(2), june 2014 oral manifestations, oral diagnosis 92 table 1: frequencies and percents of the studied groups due to doses and gender variables with comparison significant groups gender total male female g.(10 20) mg 5 29.4% 12 70.6% 17 100% g.(20 30) mg 7 46.7% 8 53.3% 15 100% g.(30 40) mg 6 33.3% 12 66.7% 18 100% total patients 18 36% 32 64% 50 100% control 10 40.0% 15 60.0% 25 100% total 28 37.3% 47 62.7% 75 100% c.s. p-value c.c. =0.126 p=0.750 : ns 0 2 4 6 8 10 12 14 )20-30 (mg )30-40 (mg control )10-20 (mg figure 1: distribution of the studied oral manifestation parameters based on the different groups of doses figure 2: the distribution of "aerobic bacteria" responding based on the different doses. 0% 2% 4% 6% 8% 10% 12% 14% 16% pe p to st ri p to c … patients control figure 3: the distribution of anaerobic bacteria responding based on the different doses j bagh college dentistry vol. 26(2), june 2014 oral manifestations, oral diagnosis 93 figure 4: the distribution of c albicans responding based on the different doses. table 2: summary statistics of salivary iga parameter at different of the studied groups parameter iga µg/ml groups (10 -20) mg (2030) mg (30-40)mg control no. 17 15 18 25 mean 226.51 178.25 173.44 236.29 std. dev. 63.84 63.98 45.41 48.58 std. error 15.48 15.48 10.70 9.72 min. 121.38 121.38 98.98 170.28 max. 319.72 319.72 250.27 337.13 table 3: multiple comparison among all pairs of iga parameter according to different treated samples (i) group (j) group c.s. (*) g.(10 20) mg g.(20 30) mg s g.(30 40) mg hs control ns g.(20 30) mg g.(30 40) mg ns control hs g.(30 40) mg control hs hs: highly significant at p< 0.01; ns: non significant at p>0.05. table 4: summary statistics of salivary flow rate parameter at different of the studied groups parameter salivary flow rate (ml/5min) groups (10 -20) mg (2030) mg (30-40)mg control no. 17 15 18 25 mean 1.69 1.53 1.46 2.54 std. dev. 0.79 0.64 0.55 0.52 std. error 0.19 0.17 0.13 0.10 min. 0.50 0.40 0.50 2.40 max. 3.00 2.50 2.40 3.50 table 5: multiple comparison among all pairs of sfr parameter according to different treated samples group group c.s. g.(10 20) mg g.(20 30) mg ns g.(30 40) mg ns control hs g.(20 30) mg g.(30 40) mg ns control hs g.(30 40) mg control hs j bagh college dentistry vol. 27(3), september 2015 the effect of different restorative dentistry 1 the effects of different investment materials on dimensional accuracy and surface roughness of thermosens maxillary complete dentures thekra i. hamad b.d.s, m.sc, ph.d (1) abdalbasit a.fatihallah b.d.s, m.sc, ph.d (1) ali j.abdulsahib b.d.s, d.d.s, m.sc (2) abstract background: limited data are available on the dimensional stability and surface roughness of thermosens, which is a material used in denture processing. this study aimed to measure the vertical teeth changes and surface roughness of thermosens dentures prepared using three different investment materials. materials and methods: for the dimensional changes test, 30 complete maxillary dentures were prepared using different investment methods: group i, dental stone; group ii, silicone putty; and group iii, a mixture of dental stone and plaster (ratio, 1:1; n = 10 for each group). eight screws where inserted, four for each side of the denture: two were attached to the buccal surface of the canine and first molar, and the other two were attached in the flange areas of the canine and first molar in line with the previously mentioned screws. measurements were made using a micrometer microscope in the wax stage before flasking and in the deflasking stage. the above investment techniques were also used to prepare samples for a surface roughness test (n = 10 per group). these samples were prepared according to the specifications of the american dental association. data were examined using analysis of variance (anova) and the least significant difference (lsd) test. results: one-way anova and lsd revealed that dimensional changes significantly differed among all groups, except that the vertical teeth changes on the left side did not differ between groups i and ii for both the canine and molar regions. surface roughness was significantly higher in group i than in group ii, and in group iii than in group ii. conclusion: the use of putty silicone for investing thermosens complete dentures reduced dimensional changes and resulted in dentures with a better fit. surface roughness could be reduced by the addition of a putty silicone layer over the denture before the addition of the second investment layer during denture processing. keywords: investment material, dimensional changes, surface roughness, thermosens. (j bagh coll dentistry 2015; 27(3):1-7). introduction denture bases dimensional stability during processing and in service is important for dentures to accurately fit the underlying foundations and satisfaction of the patient. in general, if the denture is properly processed, the original fit and dimensional stability are good, regardless of the denture base material used.(1) currently, poly(methyl methacrylate) (pmma) is widely used in prosthetic dentistry for the construction of complete and partial dentures.(2) well-known allergens in dentures include residual monomers, peroxides and metals. in patients with pmma hypersensitivity, the denture base should be constructed from other polymeric materials to which the patient is not allergic.(3) over the past 40 years, many denture-production techniques other than pressing and/or molding dentures from an mma–pmma system have been developed, from light-cured paste systems to microwave polymerization, and from the injection molding technique to thermoplastic systems. 1) assistant professor, department of prosthodontics, college of dentistry, university of baghdad. 2) lecturer, department of prosthodontics, college of dentistry, university of baghdad one of the injection molding technique advantages, is to allow directional control of the polymerization process through the flask design, and involves a constant flow of new material from the sprue, thereby compensating for polymerization shrinkage.(4) thermoplastic materials, such as polyamides (nylon plastics), were introduced as early as the 1950s. with time, several types of thermoplastic materials were developed: acetal, polycarbonate, acrylic and nylon (resin).(5,6) the first thermoplastic nylons for dental prostheses, valplast (valplast int. corp., long island city, usa) and flexiplast (bredent, germany), were introduced in 1956.(7,8) different types of prostheses can be fabricated from these materials via the injection-molding technique,(9) which is used for the fabrication of flexible denture-base prostheses.(10) fluid resin is allowed to flow into the mold cavity of these systems through sprues created using sprue formers. the resulting products are completely free of residual monomers, accelerator systems and stabilizers. moreover, the thermoplastic products are always homogenous in composition, and they respond consistently during processing. finally, these thermoplastic materials have no adverse impact on j bagh college dentistry vol. 27(3), september 2015 the effect of different restorative dentistry 2 the technician or the dental laboratory due to the absence of hazardous materials.(11,12) thermoplastics are superpolyamides that belong to the nylon family. nylon can be defined as a resin derived from dicarboxylic acid, diamine, amino acid and lactams.(13) the injection-molding technique is used for the fabrication of flexible denture-base prostheses, which can be reversibly liquefied upon heating. the molten material is placed in a mold and allowed to cool down. a range of thermoplastic materials are used in dental mechanics.(14) a new material called thermosens is superior to standard polyamide materials. the flexibility of this material can be controlled, and its shrinkage is extremely low. owing to its composition, a homogenous color can be achieved, making this material suitable for the preparation of full dentures. the purpose of this study is to compare vertical artificial teeth movement and surface roughness between complete maxillary thermosens dentures prepared by three different investment materials: (a) dental stone, (b) silicone putty (on the outer surface of the denture) and (3) dental stone mixed with plaster of paris (ratio, 1:1). materils and methods a complete maxillary denture with acrylic teeth (major, italy) was made using a master cast made from an ideal negative rubber mold represented the upper edentulous arch by pouring type iii dental stone (zhermack elite stone, italy). the record base was formed from +thermoplastic acrylic cakes (biocryl, iserlohn, germany) and manipulated using a biostar machine. the record base had an even thickness of 2 mm. a horse shoe–shaped block of wax was attached to the record base to form the occlusion rim. the wax was shaped such that the length from the highest area of the labial flange (canine eminence) to the occlusion edge was 22 mm and the length from the highest area of the buccal flange (first molar region) to the occlusal plane was 18 mm. the width of the rim was approximately 4 mm anteriorly and 7 mm posteriorly.(15) the maxillary cast was mounted on the articulator by the aid of a mounting plate, and maxillary anterior and posterior acrylic teeth were arranged in a monoplane occlusal scheme. the maxillary denture was completely waxed. the sample was removed from the articulator, and three wax sprues were prepared. two of these sprues were attached to the posterior area of the maxillary tuberosity, distal to the second molar, and the third sprue was attached to the midline of the posterior part of the palate (fig. 1). figure 1: three wax sprues are attached to the posterior part of the maxillary denture. preparation of duplicated models: duplication of the simulation denture was done by using a pourable silicone material (vertextm, castasil 21) that is meant to be used for the duplication of models supported by a plastic container that provides rigidity for the duplicating material (fig. 2). figure 2: the denture is duplicated using a pourable silicone duplicating material. thirty identical maxillary wax dentures were prepared by placing the same size set of teeth into the silicon mold, and then pouring the molten base plate wax into the mold, which was leaved to cool at 37° c for 2 hr before removal. this provided a standard wax simulation of a maxillary denture and thereby minimized variations in polymerization due to the shape and size of the dentures specimens. vertical reference point preparation one metallic reference point placed in the canine flange area of the dentures, on the facial surface of the canine, in the first molar flange area and on the buccal surface of the first molar (fig. 3). these reference points were used for vertical j bagh college dentistry vol. 27(3), september 2015 the effect of different restorative dentistry 3 measurements. the first of all a tentative measurements made by the aids of digital vernier caliper to locate the position of the screws at the wax stage before flasking, then a more precise measurements were made by using micrometer microscope to measure changes in the vertical. measurements before and after flasking procedures. on the facial surface of the canine and first molar, a line was drawn with a soft marker perpendicular to the occlusal plane and tangential to the distal surface of the canine screw and mesial surface of the molar screw by using a vernier caliper. another line was drawn perpendicular to the first line, at a distance of nearly 16 mm from the canine and 15 mm from the first molar. then a screw pin was attached to the intersection of the two lines in the selected teeth (fig. 3). figure 3: reference point measurements. ten dentures were processed for each of the three groups in the study: group i: conventional investment (dental stone) group ii: silicone putty (vertextm putty) used on the outer surface of the denture group iii: dental stone mixed with plaster of paris (ratio, 1:1) processing of the thermosens denture base material and vertical measurements after wax elimination from the denture, we used an injection machine (vertextm thermoject 22) to inject thermosens capsules (vertex thermosens, capsule size xl) into a flask, which was then allowed to cool to room temperature. once cooled, the flask was opened, and the denture was attached to the base of a surveyor, so that the reference points could be observed under a microscope. the distance between the following reference points was measured: (a) right canine–right screws, (b) right molar–right screws, (c) left canine–left screws and (d) left molar–left screws (fig. 4). figure 4: processed denture with the screws attached at the canine and molar region bilaterally .roughness test for the surface roughness test, we prepared 30 specimens with dimensions of 65 mm × 10 mm × 2.5 mm (length, width and thickness, respectively) by using thermosens capsules (vertex thermosens, capsule size xl). ten samples were assigned for each of the three groups mentioned in the dimensional changes test (american national standards institute/american dental association specification no. 12). results dimensional changes the means, standard deviations, standard error, and minimum and maximum values of the dimensional measurements in all groups are shown in table 1. one-way analysis of variance (anova) revealed significant differences (p < 0.05) in all measurements among all groups (tables 2 and 3). both canine and molar region measurements in group iii significantly differed from those in groups i and ii (tables 4 and 5). the data for the right canine and molar regions, but not the left regions, significantly differed between groups i and ii. roughness test the mean, standard deviation, and minimum and maximum values of surface roughness for groups i, ii and iii are presented in table 6. the mean roughness value was higher in group i (dental stone investment, 1.53 µm) than in group ii (silicone putty, 1.31 µm). the highest mean roughness value was observed in group iii (mixture of dental stone and plaster of paris, 1.61 µm). one-way anova table (table 7) with the least significant difference (lsd) test showed that surface roughness was significantly influenced by the material used in denture processing (p < 0.05). significant differences were found between groups i and ii (p < 0.012) and groups ii and iii (p < 0.001), but not between groups i and iii (p < 0.362); (table 8). discussion the dimensional characteristics of processed denture bases are affected by many factors, such as the type of acrylic, type of investment material, j bagh college dentistry vol. 27(3), september 2015 the effect of different restorative dentistry 4 method of resin introduction and temperature used to activate the polymerization process.(15) in this in vitro study, all laboratory dentures were measured in the wax stage and deflasking stage to determine the effect of polymerization shrinkage of the thermosens resin and the effects of investment materials on denture dimensions. changes in teeth vertical measurements of complete dentures group ii showed less shrinkage in the dimensions than did groups i and iii. table 1 show the effects of different investment methods on the polymerization of thermosens. the lowest mean difference was observed in group ii (silicone putty), while the highest was observed in group iii (mixture of plaster and stone). these results may be attributable to the type of investment material and its effect on the amount of stress relaxation. the harder the investment material, the more difficult is the deflasking procedure, which results in additional stress within the resin that is subsequently released. this explains why the least amount of shrinkage was detected in the group-ii samples. silicone putty has a high tear resistance (15) and can therefore be deflasked without difficulty by using a scalpel to cut the putty and liberate the sample. in comparison, groups i and iii, which involved gypsum investment, showed more shrinkage, as the deflasking procedure was the most difficult. these results are inconsistent with those reported in some studies,(16–18) but agree with those reported by duke et al.(19) these differences could be attributed to the use of different denture base materials and measurement methods in different studies. in group ii, the right and left vertical distances in the molar region were similar. this finding could be attributed to the less shrinkage of the resin, as silicone showed better dimensional stability than did dental stone, which expanded after processing. in the canine region, the distances differed between the right and left sides. this may be due to the position of the cast and denture within the flask, as stated by wolfaardt et al.(20) alternatively, it could be attributable to the position in the injection machine. the above results are inconsistent with those reported by abd,(16) who found greater differences in the molar areas. the differences in the vertical dimensions in the canine and molar areas between the stages of waxing and processing were highly significant on both the right and left sides (tables 2,3,4 and 5). these results may be attributable to the amount of polymerization shrinkage, thermal contraction of the resin and mold, and the stress released during deflasking. these findings agree with those of abd,(16) who reported that polyvinyl siloxane duplicating materials produce better dimensional stability, which is affected by the type of investment method used. tables 3 and 5 show the differences in mean values of the dimensional measurements between the experimental groups. the differences in molar and canine measurements between groups i and iii, and groups ii and iii were highly significant for both the left and right sides. this could be attributable to the effect of stress relaxation due to thermal contraction and polymerization contraction of putty silicone, which is mainly caused by the crosslinking and rearrangement of bonds within and between polymer chains.(21,22) the molar and canine measurements on the right, but not those on the left, significantly differed between groups i and ii. these findings may be attributed to the investment material used, i.e., type iii dental stone, which has a setting expansion of 0.15%–0.25%. (21) once the investment material is set, the mold expands only slightly, as the effect of the setting expansion of gypsum is reduced by confining it within the flask.(23) the expansion of the gypsum mold exceeds the polymerization shrinkage of putty silicone, leading to the expansion of the measured distances. the nonsignificant differences could be attributed to the erratic release of internal stress induced during the deflasking procedure. the magnitude of dimensional change depends on the conditions of molding, the shape of the mold and the direction of measurement. surface roughness the thermosens denture base material is more flexible than the commonly used pmma. however, the material polish-ability has not been examined thoroughly. the surface roughness (table 6) was lowest (1.31 μm) in group ii and highest in group iii (1.61 μm); the roughness in group i was 1.53 μm. these results indicated that the type of investment material affected the roughness of the polishing surface of the dentures. however, the roughness of the surface of the thermosens material before polishing significantly differ between groups i and ii (table 8), and this may be due to the use of diffrenet investment materials (type iii dental stone and silicone putty). the non-significant difference between groups i and iii (table 8) also may be attributable to the use of different investment materials (stone vs. mixture of dental plaster and stone). the addition of plaster, which shows more dimensional changes and a more porous surface, affected the surface roughness. our findings were consistent with other studies(24–28) that have found that the average roughness of unpolished polyamide is 1.111 ± 0.178 µm. it is difficult to j bagh college dentistry vol. 27(3), september 2015 the effect of different restorative dentistry 5 directly compare roughness values with other studies because of differences in methodology including; polishing methods, apparatus used for measuring surface roughness and material types used. groups ii and iii showed highly significant differences in surface roughness (table 8), possibly due to physical properties differences of the investment material used during processing and the use of the injection procedure and overheating. the injection molding temperature, pressure and cooling rate must be standardized for optimal denture-surface roughness in conclusion, the use of silicone putty on the outer surface of complete dentures before the investment of the second layer will reduce the dimensional changes and surface roughness of the thermosens denture base material. references 1. craig rg: restorative dental material, (10 ed). st. louis, the cv mosby co., 1997, pp 127-136, 500540. 2. kimono s, kobayashi n, kobayashi k, et al: effect of bench cooling on dimensional accuracy of heat-cured acrylic denture base material. j dent 2005;33:57-63 3. fisher aa. allergic sensitization of the skin and oral mucosa to acrylic denture materials. j am med assoc 1954; 156:238-42. 4. kiecswierczynska m, krecisz b. allergic contact dermatitis in a dental nurse induced by methacrylates. int j occup med environ health 2003;16:73-4. 5. parvizi a, lindquist t, schneider r, et al. the evaluation and advancement of dental thermoplastics. dental town magazine 2003;february:52-6. 6. negrutiu m, sinescu c, romanu m, et al. thermoplastic resins for flexible framework removable partial dentures.tmj 2005; 55(3): 295-9. 7. stern mn. valplast flexible partial dentures.new yourk state. dent j 1964;30:123-36. 8. negrutiu m, sinescu c, romanu m, et al. thermoplastic resin for flexible framework removable partial dentures. tmj 2005; 55:295-99.). 9. keenan pl, radford dr, clark rk. dimensional change in complete dentures fabricated by injection molding and microwave processing. j prosthet dent 2003;89(1):37-44. 10. alvarez a, cullivan b. valplast – the flexible partial. dental office 2003. 11. ditolla m. valplast flexible, esthetic partial dentures. chairside perspective magazine 2004;5(1):1-4. 12. levin b and richardson gd: complete denture prosthodontics. a manual for clinical procedures. (17th) edition 2002, pp.54-55. 13. carlsson ge and magnusson t: management of temporomandibular disorders in the general dental practice. quintessence publishing co, inc 1999. pp. 113. 14. keenan plt, radford dr, and clark rkf: dimensional change in complete denture fabricated by injection molding and microwave processing. j prosthet dent 2003;89(1):37-44. 15. anusavice kj. phillip’s science of dental materials. 11th edition. st.louis: w.b. saunders, 2008, pp. 145, 233, 234, 246, 247, 257, 258, 722, 737. 16. abd s r. tooth movement in maxillary complete dentures fabricated with fluid resin polymer using different investment materials.msc.thesis in prosthetic department, university of baghdad, college of dentistry,2012. 17. grant aa and atkinson hf: comparison between dimensional accuracy of denture produced with pourtype resin and with heat-processed materials. j prosthet dent 1971; 26 (3): 296-301. 18. antonopoulos a n: dimensional and occlusal changes in fluid resin dentures. j prosthet dent 1978; 39(6):60515. 19. duke bs, field h, olson jw, et al. a laboratory study of changes in vertical dimension using a compression molding and a pour resin technique. j prosthet dent 1985;53(5):667-9. 20. wolfaardt j, cleaton-jones p, fatti p: the influence of processing variables on dimensional changes of heatcured poly (methyl methacrylate). j prosthet dent 1986;55 (4):518-25. 21. craig rg and powers tm: restorative dental materials. 11th edition. st. louis: mosby, 2002, pp. 341, 344, 346, 392-94, 397, 400-3, 636-9, 647,649, 656. 22. bahannan s, abd el-hamid a, abd al-halim m.: accuracy and reproducibility of reversible hydrocolloids versus elastomers duplicating materials. the saudi dent j 1995; 7(1):7-11. 23. grant aa: effect of the investment procedure on tooth movement. j prosthet dent 1962; 12 (6):1053-8. 24. wieckiewicz m, opitz iv, richter g, et al: physical properties of polyamide-12 versus pmma denture base material, biomed research international volume 2014, article id 150298, 8 pages. 25. abuzar ma, bellur s, duong n, et al: evaluating surface roughness of a polyamide denture base material in comparison with poly (methyl methacrylate) journal of oral science 2010; 52(4):577-81, 26. kuhar m, funduk n:effects of polishing techniques on the surface roughness of acrylic denture base resins. j prosthet dent 2005; 93:76-85. 27. oliveira lv, mesquita mf, henriques gep, et al: effect of polishing technique and brushing on surface roughness of acrylic resins. j prosthodont 2008;17:308-311. 28. berger jc, driscoll cf, romberg e, et al: surface roughness of denture base acrylic resins after processing and after polishing. j prosthodont 2006;15:180-186. j bagh college dentistry vol. 27(3), september 2015 the effect of different restorative dentistry 6 الخالصة: وخشونة نباألسنا التغيرات العمودية الحاصلة قياس بهدف الدراسة هذه أعدت. األسنان الكاملةأطقم تجهيز في تستخدم مادة الثرموسنس كمادة السيليكون معجون استخدام مختلفة. ووجد إن غامسه مواد ثالث باستخدام األسنان أطقم سطح الثرموسنس المستخدم في تجهيز تخفيض يمكن وبذلك. وقللت من خشونة األسطح األبعاد التغييرات خفضت الكاملة األسنان أطقم غامسه للثرموسنس المستخدم في تجهيز .الطقم تجهيز خالل الثانية الغامسه الطبقة إضافة قبل األسنان على سيليكون المعجون طبقة إضافة خالل من السطح خشونة table 1: descriptive statistics in all groups included in the vertical change in the measurements. table 2: one-way anova of right and left canine measurements. table 3: lsd multiple comparisons test of dimensional changes in the canine region. groups n mean (mm) std. deviation minimum maximum molar measurements right group i 10 0.28 0.133 0.17 0.50 group ii 10 0.14 0.063 0.05 0.20 group iii 10 0.59 0.066 0.50 0.65 molar measurements left group i 10 0.25 0.092 0.14 0.35 group ii 10 0.14 0.066 0.08 0.25 group iii 10 0.55 0.111 0.40 0.70 canine measurements right group i 10 0.23 0.075 0.15 0.35 group ii 10 0.14 0.041 0.10 0.20 group iii 10 0.53 0.057 0.45 0.60 canine measurements left group i 10 0.20 0.095 0.10 0.30 group ii 10 0.16 0.041 0.10 0.20 group iii 10 0.52 0.103 0.35 0.60 sum of squares df mean square f sig. right side between groups 0.834 2 0.417 130.919 hs within groups 0.086 27 0.003 total 0.920 29 sum of squares df mean square f sig. left side between groups 0.764 2 0.382 59.64 hs within groups 0.173 27 0.006 total 0.937 29 mean difference sig. right side group i-group ii 0.090 s group i-group iii -0.300 hs group ii-group iii -0.390 hs mean difference sig. left side group i-group ii 0.048 ns group i-group iii -0.312 hs group ii-group iii -0.360 hs j bagh college dentistry vol. 27(3), september 2015 the effect of different restorative dentistry 7 table 4: one-way anova of right and left molar measurements. table 5: lsd multiple comparisons test of dimensional changes in the molar region. table 6: mean surface roughness (µm), standard deviation, standard error of mean, and minimum and maximum values in all groups. table 7: one-way anova for surface roughness test table 8: lsd multiple comparisons test of surface roughness among all groups. mean difference sig. group i-group ii 0.2224 s group i-group iii -0.0785 ns group ii-group iii -0.3009 hs sum of squares df mean square f sig. right side between groups 1.077 2 0.538 69.31 hs within groups 0.210 27 0.008 total 1.286 29 sum of squares df mean square f sig. left side between groups 0.893 2 0.447 58.931 hs within groups 0.205 27 0.008 total 1.098 29 mean difference sig. right side group i-group ii 0.144 s group i-group iii -0.310 hs group ii-group iii -0.454 hs mean difference sig. left side group i-group ii 0.116 ns group i-group iii -0.294 hs group ii-group iii -0.410 hs group i group ii group iii n 10 10 10 mean (µm) 1.53 1.31 1.61 std. deviation 0.22 0.19 0.278 minimum 1.04 1.02 1.005 maximum 1.89 1.74 2.008 sum of squares df mean square f sig. between groups 0.731 2 0.365 4.345 hs within groups 2.285 27 0.084 total 3.016 29 athraa.doc j bagh college dentistry vol. 27(2), june 2015 dental fluorosis pedodontics, orthodontics and preventive dentistry142 dental fluorosis, dental caries, and treatment needs in al-muthana'a governorate among 12 years old students hiba a. al-shuker, b.d.s. (1) athraa m. al-waheb, b.d.s., m.sc. (2) abstract background: a case-control study design revealeda relationship between the present of fluoride, and the reduction of dental caries and the increase prevalence and severity of dental fluorosis .the aim of this study was to assess the prevalence and severity of dental caries in relation to dental fluorosis among school children in al-muthana'a governorate. materials and methods: it was conducted among primary school students aged 12 years old, the age was taken according to the criteria of world health organization (1997) (1).the number of students was selected in each sector of control group according to number of schools in that sector .sectors of control group which depend on water of river as source of drinking water. case group which include al-salman sector that depend on underground water as source of drinking water includestudents in all area of alsalman sector in 4 schools results: results showed that the prevalence of dental fluorosis in case group, is (60.6%) and the mean of maximal fluorosis index (1.15 ±0.12) .in control group, the prevalence of dental fluorosis is (49.0%) and the mean of maximal fluorosis index (0.73±0.4) .the dmfs/dmft values of dental caries for case sample (3.83± 0.44) (2.31± 0.22), while for control dmfs/dmft is (5.95±0.26) (3.41±0.13) respectively with significantly difference. the prevalence of caries free in case sample is 23.6% while for control is 8.4% with significantly difference between case and control. conclusions:a study revealed that a high prevalence of dental fluorosis, dental caries thus there is a need for preventive programs among those children. key words: dental fluorosis, dental caries, dean index. (j bagh coll dentistry 2015; 27(2):142-147). introduction dental fluorosis, a specific disturbance in tooth formation and an esthetic condition, is defined as a chronic, fluoride-induced condition, it is a condition in which an excess of fluoride is incorporated in the developing tooth enamel, in which enamel development is disrupted and hypo mineralizedfluoride has beneficial effects on teeth at low concentrations in drinking-water, but excessive exposure to fluoride, or exposure to fluoride from other sourceswhich contain very low levels of fluoride; exceptions are some fish and tea, which particularly high in fluoride may participate in fluorosis (2,3) can give rise to a number of adverse effects. these range from mild dental fluorosis to crippling skeletal fluorosis as the level and period of exposure increases (4,5). dental caries or tooth decay is one of the most common prevalent chronic preventable (infectious) diseases. individuals are more susceptible to this disease throughout their lifetimes; it is reversible in its early stages by modifying or eliminating etiologic factors and increasing protective factors (6).there is also mounting evidence that dental fluorosis in it is more advanced stages render the teeth more susceptible to cavities as noted by many resources (7, 8). (1)m.sc. student department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2)professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad but in general fluoride prevents tooth decay by changing the structures of enamel in infant, making it more resistant to acid attack. it also encourages the remineralization of teeth and may inhibit enzymes used by bacteria to form acid (9, 10). materials and methods the sample included all school children at age of (12 years old) males and females that selected randomly among primary school students in almuthana’a governorate. permission was obtained from the general direction of education of almuthana’a governorate to conduct the study with no obligation, also an informed consent prepared and distributed before doing the oral exam. the representative sample that selected randomly (507), (242) girls and (265) boys.control group which depend on water of river as source of drinking water, include (380) students divided to (193) male and (187) female. case group which include al-salman sector that depend on underground water as source of drinking water, include (127) student in all area of alsalman sector with (72) boys and (55) girls. in this study the students that selected should be born and lived in area of examination and do not used any form of fluoride supplement, children without permission from their parents, with serious systemic diseases were not examined, all these questions was be recorded, the child who did not meet these criteria should be excluded j bagh college dentistry vol. 27(2), june 2015 dental fluorosis pedodontics, orthodontics and preventive dentistry143 from the study, 15 students were excluded from the while samples. oral examination examinations and oral health assessments were performed according to the basic methods of who (1997). all the examined teeth were dried with cotton wool, the tooth was considered a fully erupted when at least 2/3 of the crown erupted with no gingiva covering it (i.e. the examination included all fully erupted permanent teeth and all primary teeth were excluded from the examination also permanent teeth with crown or labial veneer or retained root were excluded from the examination. statistical tests used in analysis kolmogorovsmirnov test, chi-square, mann-whitney u test.the diagnosis of dental fluorosis was recorded according to the criteria of dean index(11). each tooth had been graded as normal or one of the following degrees of fluorosis (questionable, very mild, mild, moderate and severe) for assessment of prevalence of dental fluorosis within individual and teeth. in addition to assessing the degree of dental fluorosis within individual, dean devised means of calculating the degree of fluorosis within a community by the use of community fluorosis index (12). community fluorosis index = results figure (1) demonstrated thecomparison in mean and standard error of maximal fluorosis index between case and control group, the mean value in case group (1.51± 0.04) was higher than in control one (0.73± 0.12) with difference in mean (0.78), and highly significant difference between two means (p<0.05). while in table (1) shows the prevalence of students who suffer from dental fluorosis, each tooth has been graded according to dean index for assessment of prevalence of dental fluorosis for individual. according to table. in cases, 60.6% of persons suffer dental fluorosis range from questionable to severe score with highest score was moderate and the median was very mild, in controls, the percentages of individuals suffer from dental fluorosis reaches to 49%, range between questionable to severe score with highest score was very mild and the median was normal, the difference between case and control group statistically highly significant (p<0.001). in table (2) it was illustrated the maximum fluorosis score in case and control group and the difference in mean (cfi) between males and females in two groups, and the table revealed thatmaleswas higher than femalesin means of two groups. statistically, non-significant difference between two means in case and control group table (3) revealed the mean value and standard error of the caries experience of dmfs for permanent teeth and its components (ds, ms, fs) for the total sample ofcase and control group in general, it was found that caries experience represented by dmfs was higher among control group (5.95±0.26) as compared with case group (3.83±0.44),statistically; dmfs illustrates highly significant differences between two groups (p<0.001),the decay surface(ds) fraction was higher among controls with highly significant difference, the same was seen for missing surface (ms)with significant difference ,while for filling surface fraction (fs) no significant differences was found between case and control.in figure (2) found that dmft in control group have mean value and standard error (3.41± 0.13), it was higher than dmft in case group (2.31± 0.22) in figure (3) illustrates the percentage of children with each category of treatments needs in case and control group. children in needs of restoration were showed the highest percentage, followed by ,fissure sealant, preventive care, extraction, and need for other care like pulp care, orthodontic treatment and crowns, in all categories show treatment needs in control group higher than in case group. j bagh college dentistry vol. 27(2), june 2015 dental fluorosis pedodontics, orthodontics and preventive dentistry144 figure 1: mean maximal fluorosis index in case and control groups table 1: maximum fluorosis score in case and control group according to severity from dental fluorosis. study group maximum fluorosis score case group controlgroup p-value n % % n normal 50 39.4 51.1 194 <0.001** questionable 2 1.6 6.6 25 very mild 14 11.0 22.8 87 mild 14 11.0 12.6 48 moderate 39 30.7 6.1 23 severe 8 6.3 0.8 3 total 127 100.0 100.0 380 median very mild normal **highly significant table 2: maximum fluorosis score in case and control group (mean ± standard error) according to gender study group community fluorosis index (cfi) male female p difference in mean case group mean ± se n mean ± se n ns -0.51 1.80±0.19 55 1.29±0.16 72 control group mean ± se n mean ± se n ns -0.07 0.76±0.06 187 0.69±0.06 193 table 3: dmfs means for case and control group with fractions. study group caries experience case group /n=127 control group /n=380 p difference in mean mean± se mean± se ds 3.48±0.37 4.88± 0.20 <0.001** -1.4 ms 0.35±0.15 0.93±0.13 0.015* -0.58 fs 0 0.14±0.07 ns -1.14 dmfs 3.83±0.44 5.95±0.26 <0.001** -2.12 * significant ** highly significant j bagh college dentistry vol. 27(2), june 2015 dental fluorosis pedodontics, orthodontics and preventive dentistry145 figure 2: dmft in case and control group figure 3: treatment needs in case and control group. discussion the association between dental caries and dental fluorosis has been well established in this present study and it is revealed clearly that increase in dental fluorosis lead to decrease in dental caries experience. so through all the studies carried out in this field, it is apparent that there was optimal level of fluoride in drinking water for beneficial dental effects thatit was with 1ppm of fluoride there will be reduction of dental caries and esthetically accepted development. the criteria selected for assessment of dental fluorosis in this study is dean index (1934) which adopted by who 1997, these criteria depend on clinical appearance of the teeth and not on the histological back ground, so it was a simple description pattern and easy to be used to identify groups of lesions that were likely to be good reflection of the prevalence and severity of dental fluorosis within students considered (13). results of this study supported by results was obtained from national laboratory for water (department related to ministry of municipalities j bagh college dentistry vol. 27(2), june 2015 dental fluorosis pedodontics, orthodontics and preventive dentistry146 and public works) that was made previously analyzing fluoride ion in many samples of drinking water in different places in governorate from (12/2013 to 5/2014), the results with average between (0.79 -1.76) ppm, with take in the consideration ; the city depend on euphrates river as main sources of drinking waterin comparison with other studies in a iraq (14) that revealed percentages of fluoride in water in other governorates that lay in euphrates rivers: (albasrah: 0.10, karbala: 0.12, babel: 0.19) ppm, this revealed that concentration of fluoride in drinking water of al-muthanaa governorate was higher than others near. al-ajrab (10) in nineveh governorate found that concentration of fluoride in drinking water in sinjar province (2.05-2.22 ppm) from borehole and range between (0.110.19ppm) in talkaif province .the results of this study revealed that in case group a prevalence of dental fluorosis of about 60.6, and in control group the prevalence of dental fluorosis is 48.9%. the results of this study revealed that a prevalence of dental fluorosis in case group was 60.6%, while, in control group was 48.9% ,which was lower than al-ajrab study who was found that the percentage of affected teeth with dental fluorosis in sinjar province was 62.9%.this study was found the prevalence of fluorosis is higher than study obtained from qatar (15). all these data obtained in these studies indicated that this high prevalence of dental fluorosis comparing with the concentration of fluoride in drinking water was related to climatic condition in this areas, the high temperature especially in hot season (summer) lead to high attitude of the individual for consumption of high quantity of water, this lead to increasing in fluoride concentration reached to body of individual during teeth formation ,which will affect in teeth an create dental fluorosis. also the difference between examiners in interpretation of criteria of the index used may cause this variation of prevalence in dental fluorosis (16). dental fluorosis prevalence was more among females as compared to males in both case and control group also this is may be due to difference in shedding and eruption time between two genders. the decayed fraction “ds” was the major component of dmfs index and the mean value higher in control than in case group. in case group, however this region relatively far away from governorate oral health services; stay it is means less than control group, this reflects the benefit of fluoride in drinking water for reducing the evidence of dental caries. the mean “ms” was greater than “fs” in both groups; this may indicate that even when dental services are available in control group they were directed towards extraction rather than preserving permanent teeth, which may reflect a knowledge and attitude among some of parents and dentists responsibility and loss governorate oral health services on the part of regional health affairs this result was in agreement with al-salman (17); baram (18) al-galebi (19) and al-sadam (20). concerning treatment needs, this study revealed that most of students were in need for restorations come at first objective, followed by need to fissure sealant and preventive care among other types of dental treatment needs ,this results in both case and control groups ,this was agreed with results reported by other iraqi studies (20) and disagree with other (21). references 1. who. oral health surveys. basic methods. 4th ed. geneva: world health organization; 1997, 19. 2. warren jj, levy sm. current and future role of fluoride in nutrition. dent clin of north am 2003; 47: 224–43. 3. fomon s, ekstrand j, ziegler ee. fluoride intake and prevalence of dental fluorosis: trends in fluoride intake with special attention to infants. j of public health dent 2000; 60(3): 131–9. 4. smith rs. world water day: oral health. geneve: world health organization; 2008. 5. who (2006). fluoride in drinking-water. geneva, world health organization https://www.who.int/water_sanitation_health/publicati ons/fluoride_drinking_water_full.pdf 6. zero dt, fontana m, martinez-mier ea, ferreirazandona a, ando m, gonzalez-cabezas c, bayne s. the biology, prevention, diagnosis and treatment of dental caries. scientific advances in the united states. jada 2009; 140(supp 1): 25s-34s. 7. zohouri fv, rugg–gunn aj. sources of dietary fluoride intake in 4 year of children residing in low medium andhigh fluoride areas in iran. int j food sci nutr 2000; 51: 317–26. 8. alarcon–herrera mt, et al. well water fluoride. dental fluorosis, bone fracture in the guadiana valley of mexico. fluoride 2001; 34(2): 139–49 9. peterson g, kambara m. remineralisation study of artificial root caries lesions of the fluoride treatment. gerodontol 2004; 21(2): 85–92. 10. al-ajrab m. dental fluorosis and dental caries prevalence in iraqi children living in area with low and high level of natural water fluoride. a master thesis,college of dentistry, university of mosul, 2000. 11. dean ht. classification of mottled enamel diagnosis. jada 1934; 20: 313–9 12. dean ht. production of mottled enamel halted by a change in community water supply. am j pub hlth 1939; 29: 567–75 13. ipcs. fluorides. geneva, world health organization, international programme on chemical safety (environmental health criteria 2002; 227. 14. al-azawi la. oral health status and treatment needs among iraqi five years old kinder garden children and https://www.who.int/water_sanitation_health/publicati j bagh college dentistry vol. 27(2), june 2015 dental fluorosis pedodontics, orthodontics and preventive dentistry147 fifteen years old students (a national survey). ph.d. thesis, college of dentistry, university of baghdad, 2000. 15. khalid a.the presence of dental fluorosis in the permanent dentition in doha. eastern mediterranean health j 2004; 10(3): 1. 16. gasper mr, periera ac, moreira bh. estimation of opacities of fluoride origin from fluoride area contained (0.2 ppm) fluoride and optimal (0.7 ppm) concentration. br dent j 1995; 5(2): 13–8 17. al-salman fd. prevalence of dental caries among primary school children aged 6,9,12 years old in mosul city/nineveh. a master thesis, college of dentistry, university of mosul, 1998. 18. baram a. oral health status and treatment needs among primary school children in sulaimani city. a master thesis, college of dentistry, university of baghdad, 2007. 19. al-ghalibi sn. oral health status and treatment needs in relation to nutritional status among 9-10 year-old school children in nassiryia city/ iraq. a master thesis, college of dentistry, university of baghdad, 2011. 20. al-sadam n. oral health status in relation to nutritional and social status in kerbal'a governorate for primary school students aged 12 years old. a master thesis, college of dentistry, university of baghdad, 2013. 21. al-ani n oral health status, treatment needs and dental anomalies in relation to nutritional status among 12 year-old school children in heet city/al-anbar governorate/iraq. a master thesis, college of dentistry, university of baghdad, 2013. الخالصة .الضابطة اوضحت العالقة بین وجود الفلور وانخفاض نسبة التسوس الى ارتفاع نسبة تبقع االسنان نتیجة الفلورة -دراسة المجموعة -:المقدمة .ھو توضیح العالقة بین شدة التسوس نسبة الى تبقع االسنان بین اطفال المدارس في محافظة المثنى : ھدف البحث عدد الطلبة الذین اختیروا في كل قطاع 1997سنة وھذا العمر اختیر اعتمادًا على شروط منظمة الصحة العالمیة 12ھذه الدراسة نفذت على طلبة المدارس عمر -:سالیب الطرائق واال تعتمد على ماء النھر كمصدر لماء الشرب المجموعھ مجموعة عات بصورة عشوائیةعلمًا ان قطا وقد تم اختیار الطلبة. اعتمادًاعلى عدد المدارس في ذلك القطاع المجموعھ في مجموعة سنة والذي طبقت علیھم 12عمر مجموعة الضابطة تشمل قطاع قضاء السلمان الذي یعتمد على میاة االبار كمصدر لماء الشرب والذي شمل كل الطلبة الموجودین في ذلك القطاع. .المواصفات بلغت شدة فلورة االسنان المجموعھ بینما في مجموعة ) . 1.15± 0.12(واعلى معدل للفلورة بلغ %) 60.6(النتائج اوضحت شدة فلورة االسنان في مجموعة الضابطة بلغت -:النتائج بالتتابع بینما في مجموعة ) 2.31± 0.22)(3.83± 0.44(للتسوس في مجموعة الضابطة بلغ dmfs / dmftمعدل ) . 0.73± 0.4( واعلى معدل للفلورة بلغ %) 49.0( بینما % 23.6نسبة االسنان الغیر مصابة بالتسوس في مجموعة الضابطة بلغت . بالتتابع بأختالف معنوي ) dmfs / dmft )0.26 ±5.95)(0.13 ±3.41بلغ نسبة المجموعھ .بأختالف معنوي بین المجموعتین% 8.4المجموعھ في مجموعة .الدراسة اوضحت وجود نسبة تبقع اسنان ونسبة تسوس عالیة لذلك تحتاج الى تطبیق برامج وقائیة على طلبة المدارس -:ت االستنتاجا deanمقیاس, تسوس االسنان , تبقع االسنان :مفتاح الكلمات type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 76 review article molar tubes and failure rates – a review nawar m. hasan 1*, yassir a. yassir 2, grant t. mcintyre 3 1. postgraduate student, department of orthodontics, college of dentistry, university of baghdad, iraq. 2. assistant professor, department of orthodontics, college of dentistry, university of baghdad, iraq. 3. honorary professor of orthodontics, school of dentistry, university of dundee, uk. * correspondence email; nawwar.mohammed1203a@codental.uobaghdad.edu.iq abstract: objectives: to review the failure rates of molar tubes and the effect of molar tube base design, adhesive type, and bonding technique on the failure rates of molar tubes. data: the revolution of molar bonding greatly impacted fixed orthodontic appliance treatment by reducing chair-side time and improving patient comfort. even with the many advantages of molar bonding, clinicians sometimes hesitate to use molar tubes due to their failure rates. sources: internet sources, such as pubmed and google scholar. study selection: studies testing the bond failure rate of molar tubes. conclusions: the failure rate of the molar tubes can be reduced and the bond strength of the molar tubes can be improved by changing the design of the molar tube base, the adhesive type, and the bonding technique. keywords: molar tubes, bond failure, bonding technique, bonding adhesive, base design. introduction a molar tube is a terminal attachment in the shape of a metal tube bonded on the buccal surface of molars through which the archwire slides as the teeth move (1). they can be categorized based on the mode of attachment as weldable (welded onto bands) and bondable (bonded to the tooth surface) (figure 1), based on the lumen shape as round, oval, and rectangular (figure 2), based on the number of tubes as single, double, and triple (figure 3), and based on the technique/prescription as begg tube, edgewise tube (0° tip and torque values), and pre-adjusted edgewise (with prescribed in-out, tip, and torque values) (2): figure 1: types of molar tubes based on the mode of attachment. (a) weldable molar tubes (b) bondable molar tubes (3). received date: 01-03-2023 accepted date: 06-04-2023 published date: 15-06-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/lice nses/by/4.0/). https://doi.org/10.26477/jb cd.v35i2.3407 mailto:nawwar.mohammed1203a@codental.uobaghdad.edu.iq https://orcid.org/0000-0003-1945-6078 https://orcid.org/0000-0001-9577-8947 https://orcid.org/0000-0002-7224-4739 https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3407 https://doi.org/10.26477/jbcd.v35i2.3407 j. bagh. coll. dent. vol. 35, no. 2. 2023 hasan et al 77 figure 2: types of molar tubes based on lumen shape. (a) round (b) oval (c) rectangular (2). figure 3: types of molar tubes based on the number of tubes. (a) single (b) double (c) triple (4). bonding of molars in the past, orthodontists preferred to band molar teeth during fixed appliance therapy. but more recently, the popularity of molar tubes has increased and become a routine procedure, especially with the evolution of adhesive systems (5-8). molar bonding has multiple advantages over banding. these advantages include; better oral hygiene can be maintained (8), therefore, less plaque accumulation, gingival inflammation, and periodontal problems (9,10), no need for antibiotic prophylaxis in patients at risk from bacteremia (6), more patient comfort by eliminating painful banding experiences (11,12), eliminating the need for separators and the spaces caused by the bands (6), better esthetic (13-15), reducing the chairside time and allowing completion of the bonding procedure in a single visit (16,17), and allowing easier detection of caries (14,15). the most important disadvantage of molar bonding is the failure of bonding which tends to delay treatment time, which is considered a primary concern for most orthodontists and patients looking for orthodontic treatment. another disadvantage of molar bonding is the higher rate of enamel decalcification and white spot lesion formation with bonding molars than with banding (7,8,12,18-21). the molar tubes and the bonding adhesives provide a retentive site for plaque accumulation and this new site is susceptible to caries (22-24). j. bagh. coll. dent. vol. 35, no. 2. 2023 hasan et al 78 bond failure despite the advantages of direct bonding of molars in terms of comfort, shorter chair time, and minor periodontal damage, a lot of orthodontists still prefer to band molars in orthodontic treatment due to the better reliability of molar bands and higher bond failure of molar tubes (8,19,25,26). attachments bonded to molars showed a lower bond strength and a higher clinical failure rate than those bonded to teeth more anteriorly in the arch (5,28-30). the difficulty in achieving adequate moisture control during bonding, the high masticatory forces on molars, the different etching patterns, the inadequate adaptation of the molar tube base causing an uneven adhesive layer, the differences in acid-etching times, and individual variations in enamel composition are potential factors of bond failure (12,14,18,28-32). failure rates in the early years of bonding molars, bonded molar tubes were found to have a high failure rate (up to 30%) when compared with bonded brackets on other teeth (5,6). in 1999, millett et al. did a retrospective study and analyzed patients ’ records. they found the overall failure rate was 21%, with 22% in the maxillary molars and 20% in the mandibular molars (33). in 2001, millett et al. reported that molar tubes bonded with either a light-cured or a chemically-cured resin adhesive had shown failure rates greater than 21% (29). in 2005, pandis et al. recorded a total failure rate of 14.80% with the greatest failure rates in the second molars on all quadrants (34). in 2007, banks and macfarlane compared the failure rates of molar tubes and molar bands and found that the molar tubes had twice the failure rates of the bands. the failure rates of molar tubes varied from 14.8% to 29.5% (6). in 2011, nazir et al. found that molar tubes placed on the first permanent molars during fixed orthodontic appliance treatment have higher failure rates than bands (19). in 2014, jung tested failure rates of brackets and molar tubes in young (under 18 years) and older patients (over 18 years). he found no significant difference in the failure rates of molar tubes when the first molars are compared to the second molars. he also found that failure rates of molar tubes were higher in younger patients (15.3%) than in older ones (5.2%) (35). in 2016, oeiras et al. compared the failure rates of molar tubes and molar bands. after 12 months of follow-up, they found that banded molars had a failure rate of 30.5% and bonded molars had a failure rate of 28.8%. the bonded molar tubes showed the first bond failure in the first two months, whereas the bands showed the first failure within three months (8). in 2018, gupta and mahanta reported that the failure rates of molar tubes were more than the failure rates of brackets on premolars, canines, and incisors. they also found that the failure rates were greater in the upper right second molars and upper left first molars (10). discussion the effect of base design on failure rates manufacturers have improved the mechanical retention of molar tubes by introducing undercuts in cast molar tube bases or by welding mesh wires of varying diameters to the base and incorporating different designs in the mesh itself. other techniques to enhance retention include; structuring bases using laser, sandblasting, plasma-coated metal bases, and fusing the bases with metal or ceramic particles (6,36-39) (figure 4). j. bagh. coll. dent. vol. 35, no. 2. 2023 hasan et al 79 in 2013, matasa found that the most significant influencing factors concerning the mesh design are the wire diameter of the mesh and the mesh number (the number of openings per unit of area of the mesh). mesh bases provided greater shear bond strength with larger mesh spaces (apertures) than bases with smaller mesh apertures. air needs to have the ability to escape the base for the resin to penetrate effectively and this is influenced by the free volume between the attachment base and the mesh (36,39,41). figure 4: bracket bases under an electron microscope with x25 magnification in (a) and (c) and x200 magnification in (b) and (d). (a) and (b) laser-structured bracket base. (c) and (d) a simple foil mesh bracket base (40). base design refinement and improved adhesive systems allowed the manufacturers to decrease the size of the molar tube without affecting bond strength (6,36,38,39,41). in 2012, talpur et al. conducted a study to test the relationship between bond strength and molar tube base surface area. the molar tubes tested had different base surface areas and different profiles. no statistically significant relationship was found between bond strength and molar tube base surface area (42). the effect of adhesive type on failure rates the adhesive should be strong enough to keep the molar tube attached to the tooth surface and resist tensile, shear, torque, and functional stresses during the orthodontic treatment. still, it should not be too strong that causes damage to the enamel when the tube is removed. the enamel fracture causes staining and plaque accumulation on the rough surface (40,43-45). there are different types of orthodontic adhesives with different values of bond strength depending on the properties of the material (33,46). when comparing chemically-cured and light-cured composites, no statistically significant differences in bracket failure rates were reported. but when comparing chemically-cured composite and chemically-cured conventional glass ionomer cement, the latter showed statistically significantly higher failure rates than the chemically-cured composite (47-49). in 2000, millett et al. reported no statistically significant differences between compomer and composite failure rates (50). in 2004, aljubouri et al. found no significant difference, clinically and statistically, between the bond failure rate of the self-etching primer and the two-stage (etch and primer) bonding system. this was supported by similar results by banks and thiruvenkatachari (51,52). in 2005, pandis et al. conducted an in-vivo study to assess the failure rates on molar tubes bonded with 3m transbond plus self-etching primer on the first and second molars. molar tubes bonded on first molars with self-etching primer showed failure rates comparable with those for tubes bonded with conventional acid etching (34). in 2019, a study by tanbakuchi et al. revealed that the addition of amorphous calcium phosphate to resin-modified glass ionomer cement significantly decreases the shear bond strength of molar tubes j. bagh. coll. dent. vol. 35, no. 2. 2023 hasan et al 80 compared to the conventional resin bonding system (53). in 2021, griffin et al. conducted an in-vitro study comparing the shear bond strength of four adhesive systems. the adhesive systems included one etch-and-rinse adhesive system and two all-in-one adhesives. still, enamel was acid etched before applying adhesives, and one new all-in-one bonding agent (8th generation) together with a traditional adhesive used to bond molar tubes. all adhesives showed acceptable shear bond strengths for clinical use, without any significant differences in shear bond strengths when used to bond molar tubes (54). the effect of bonding technique on failure rates despite the recent advancements in increasing the retentive strength of orthodontic adhesive systems and reducing the failure rate of orthodontic attachments, it may be more important to improve the procedure of bonding, especially for molars that are subjected to high occlusal forces (5,15). many in-vitro studies have tested different bonding techniques that might reduce the frequency of molar bond failures. johnston and mcsherry (1999) reported that sandblasting the foil mesh base of the molar tube provided only a minimal improvement in clinical performance (55). pinzan-vercelino et al. (2011) conducted an in-vitro study. they observed that applying an additional layer of adhesive at the occlusal molar/tube interface increased the shear bond strength of the molar tube (15) (figure 5). nascimento et al. (2014) did an in-vivo study. they reported that adding an adhesive layer at the molar/tube interface provides higher bond strength than can be achieved with conventional direct bonding (12). figure 5: a molar tube bonded with an additional layer of resin (red arrow) in the buccal (a) and occlusal (b) view (17). in 2017, abu alhaija et al. studied the effect of silane-coating of molar tube bases and enamel micro-abrasion (18% hydrochloric acid and pumice) on the shear and tensile bond strengths of molar tubes. the greatest shear and tensile bond strengths were reported in molar tubes bonded to molars pre-treated with micro-abrasion before the conventional acid etching with the addition of silane to the molar tube bases. while molar tubes bonded to molars pre-treated with micro-abrasion only and molar tubes bonded to molars pre-treated with micro-abrasion with the addition of silane to the molar tube bases without the conventional acid etching; recorded bond strength values similar to that of the molar tubes bonded to molars etched with 37% phosphoric acid gel (56). in 2020, ganiger et al. investigated the effect of sandblasting enamel surface instead of acid etching on the bond strength. they found that sandblasting using 50μ aluminum oxide particles instead of the acid etching technique improved the bond strength. moreover, sandblasting using 100μ aluminum oxide particles recorded higher bond strength j. bagh. coll. dent. vol. 35, no. 2. 2023 hasan et al 81 than 50μ particles (57). in 2020, jardim et al. conducted an in-vitro study and found that using flowable resin adhesives as a bonding reinforcement (the additional adhesive layer at the molar/tube interface) does not provide a significant increase in the bond strength of the molar tubes (17). conclusion with the advancement of enamel bonding techniques, molar tubes have become more popular among orthodontists. the main setback of molar bonding was the high failure rates of molar tubes which lengthened the treatment time and increased the number of emergency visits. changes in the molar tube base design, adhesive type, and bonding technique have improved the bond strength of molar tubes and reduced failure rates. the base design of molar tubes was improved by incorporating undercuts in the base design and welding mesh wires of different sizes in the molar tube base. composite resins are still superior to other types of adhesives. the bonding technique was improved by sandblasting, enamel micro-abrasion, and adding an adhesive layer at the occlusal molar/tube interface. conflict of interest: none references 1. al-zubaidi, hj., alhuwaizi, af. molar buccal tubes front and back openings dimensions and torsional play. j bagh coll dent. 2018; 30(3): 32-39. )crossref) 2. singh, g. textbook of orthodontics. second ed., jaypee brothers medical publishers, new delhi, 2007. 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األسنان تقويم بأجهزة العالج على كبير تأثير ضرسي ال لصقال لثورة كان : الدراسة اختيار .google scholarو pubmed مثل اإلنترنت، مصادر: المصادر. فشلهم معدالت بسبب ضرسيةال األنابيب استخدام في أحيانًا األطباء يتردد ،ضرسيال للصق تصميم تغيير طريق عن ةضرسيال لألنابيب لصقال قوة تحسين ويمكن ةضرسيال األنابيب فشل معدل تقليل يمكن: الخالصة. ةضرسيال لألنابيب لصقال فشل معدل رتختب دراسات . لصقال وتقنية الالصقة المادة ونوع ي ضرس ال األنبوب قاعدة type of the paper (article journal of baghdad college of dentistry, vol. 35, no. 2 (2023), issn (p): 1817-1869, issn (e): 2311-5270 10 research article the effect of titanium dioxide nanoparticles on the activity of salivary peroxidase in periodontitis patients mays a. talib 1, basima g. ali 2, eaman a. al-rubaee 3, maysaa mahdy4 1. al anbar health directorate, ministry of health, iraq. 2. department of periodontics, college of dentistry, university of baghdad, iraq. 3. department of basic science, college of dentistry, university of baghdad, iraq. 4. al-sader dental specialized center, ministry of health, iraq. * correspondence email; dr.basimaali@gmail.com abstract: background:the technology of nanoparticles has been expanded to many aspects of modern life. titanium dioxide nanoparticles were of many nanomaterials utilized in biomedical applications. the interactions between nanoparticles and proteins are believed to be the base for the biological effect of the nanoparticles. the oxidation reaction of many substances is catalyzed by oxidizing enzymes called peroxidases. the activity of salivary peroxidase is elevated with periodontal diseases. the aim ofthis study is to examine the action of titanium dioxide nanoparticles on salivary peroxidase activity.material and method75 participants were enrolled in this study—periodontitis group with 44 participants and the non-periodontitis group with 31 participants. the participants' age range was 35 to 50 years for both groups. the clinical parameters of plaque index, gingival index, probing pocket depth and clinical attachment level were used in this study to determine the presence or absence of the periodontal disease. unstimulated saliva was collected from all participants and analyzed for the activity of peroxidase enzyme under the effect of titanium dioxide nanoparticles. resultsthe periodontitis group showed higher peroxidase enzyme activity than the non-periodontitis group and the activity of salivary peroxidase showed no correlation with the clinical parameters. titanium dioxide nanoparticles increased salivary peroxidase activity. conclusionthis study demonstrated that the solid surface of nanoparticles could induce changes in the attached protein molecule which in turn causes changes in the effect of the nanoparticles on living tissue or organism. the titanium dioxide nanoparticles play a role in increasing the activity of salivary peroxidase within the saliva of chronic periodontitis patients. keywords: tio2 nanoparticles, salivary peroxidase, periodontitis, saliva. introduction periodontitis is a wide-spreading disease characterized by the pain-free and sluggish spread of the condition. this disease starts with a plaque under the gingiva and is altered by the immune response. the disease can occur in different age groups but is most common in adults. it causes loss of the periodontium, which in time leads to tooth mobility and loss (1,2). periodontitis and other inflammatory diseases are related to what is known as oxidative stress. in periodontitis, an imbalance or a shift occurs between antioxidant and oxidant enzymatic and non-enzymatic defense systems. during inflammation, the polymorph nuclear leukocytes make reactive oxygen species (ros) which are very disastrous to the tissue. the damage caused by these ros is removed or repaired by antioxidants (ao)(3). peroxidases are oxidizing enzymes that trigger oxidation reactions for different materials. hydrogen peroxidase (h2o2) helps the reaction to continue then it's reduced to water (4). peroxidase can be found in received date: 20-04-2022 accepted date: 29-05-2022 published date: 15-06-2023 copyright: © 2022 by the authors. submitted for possible open access publication under the terms and conditions of the creative commons attribution (cc by) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.26477/j bcd.v35i2.3393 mailto:dr.basimaali@gmail.com https://orcid.org/0009-0006-4249-9796 https://orcid.org/0000-0001-5539-2548 https://orcid.org/0000-0001-6230-098x https://creativecommons.org/licenses/by/4.0/ https://creativecommons.org/licenses/by/4.0/ https://doi.org/10.26477/jbcd.v35i2.3393 https://doi.org/10.26477/jbcd.v35i2.3393 j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 11 bodily fluids such as saliva and tears. in addition, it can be found in cells, removing free radicals with the assistance of h2o2. the two structures of peroxidases, which are salivary peroxidase and myeloperoxidase, are detected in the whole saliva and play an important role in the defense mechanism (5). nanomaterials consist of components less than 100 nm in at least one dimension6. titanium dioxide nanoparticles (tio2 nps) have many distinctive qualities and properties such as compatibility with living tissue and optical properties7 and many studies showed its antibacterial activity(8,9) when added to dental materials, therefore tio2 nps have been investigated profusely in recent years to make advances in dentistry. te aim of this study was to analyze the action of tio2 nps on peroxidase enzyme activity in patients suffering from chronic periodontitis. subjects and methods 1. sample selection: in this study, two study groups were recruited. the first group (group 1) consisted of 44 participants (periodontitis group), while the second group (group 2) consisted of 31 participants (non-periodontitis group). the total number of participants was 75 and the age range was from 35 to 50 years. the collection of the samples started in october and finished in december of 2017. the participants were patients seeking treatment in the department of periodontics at the college of dentistry, university of baghdad. both consent forms and ethical approval were acquired for this study. 2. clinical examination: the periodontal parameters (gingival index(10), plaque index (11), bleeding on probing, clinical attachment level, and probing pocket depth were used for the assessment and diagnosis of the periodontal condition of the participants. 3. collection of saliva the spitting method for the collection of whole unstimulated saliva was used. patients were asked to rinse their mouth first, then wait a few minutes before spitting into a plane tube to collect 5 ml of saliva. this was done at least one hour after the participant’s last meal. the time of sample collection was between 9 a.m.11 a.m. after the collection of the sample; it was centrifuged for 15 minutes at 2500 rpm. a layer called supernatant is formed and then collected and stored in an eppendorf tube at -20˚c. 4. laboratory procedures: a. saliva sample volume determination: to determine the best saliva volume to obtain the optimum activity of peroxidase, different volumes of saliva samples were tested (20, 40, 60, 80, and 100µl). in this experiment, different volumes of saliva were collected (20, 40, 60, 80 and 100 µl) to determine the best saliva volume to measure the activity of salivary peroxidase. the optimum enzyme activity for this experiment was found to be (100 µl). j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 12 b. characterization of titanium dioxide nanoparticles: tio2 nanopowder was obtained from hongwu international group ltd, guangdong, china. an ultraviolet-visible spectrophotometer (pg instruments limited/ united kingdom) was used to determine the absorption spectra for the tio2 nps solution used in this study. the measurement was done at room temperature. the size and structure of the tio2 nps in the samples were determined using a transmission electron microscope tem (philips cm10). c. salivary peroxidase assay: the colorimetric method was used to determine the activity of the peroxidase enzyme in saliva. in this study, 4-aminoantipyrine was used as a hydrogen donor. the h2o2 decomposes through the incubation period causing an elevation in absorption at λ= 510 nm, which helps in determining the activity of the enzyme, after adding 1.4 ml of 4-aminoantipyrine (2.5 mm) with phenol (0.17 m) solution to 1.5 ml of h2o2 (1.7 mm) in a buffer of phosphate (0.2 m) of ph 7.0 solution. the initiation of the reaction was done by adding saliva (100µl). to obtain (∆a/min) the elevation in absorbance at 510 nm was calculated for 5 minutes. one unit of enzyme activity represents one µmole decomposition of h2o2 through the period of one minute at ph =7.0 under certain conditions. d. preparation of tio2 nps solution: the first step was to prepare a stock solution of tio2 nps (300 µg/ml). a solvent of 3:1 water to ethanol was used to dilute the stock solution to different concentrations (20, 40, 60, 80, 100, and 120 µg\ml). the best concentration was found to be 120 µg\ml. e. determination of the action of tio2 nps on the activity of peroxidase enzyme: a detection kit was used to measure the action of tio2 nps on the activity of peroxidase enzyme by adding 20 µl of 120 µg\ml tio2 nps to 100 µl of saliva and then using the detection kit. to measure the absorbance at a wavelength of 510 nm and establish the peroxidase activity in the sample. a percentage of activation equation was used to calculate the effect percentage.the activity of the enzyme with the presence of tio2 nps and without the nanoparticles was compared according to the percentage of activation equation to calculate the percentage of effect on the peroxidase enzyme activity: % activation = 100 – 100 × [activity in the presence of nanoparticles/activity without the nanoparticles]. 5. statistical analysis: statistical package for social sciences (spss) and microsoft office excel were used to analyze the collected data. the significant difference was assesedusing the student t-test (p < 0.05). the pearson correlation coefficient was also used. results 1. clinical findings j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 13 the mean values and standard deviations (sd) of peroxidase activity for group 1 were highly significant compared to group 2 (p< 0.001). the mean values and sd of peroxidase activity for both groups are shown in table1: table 1: mean, standard division, t-test and p-value of peroxidase activity for group1 and group2: n: number, sd: standard deviation, t-test: student's t-test, p-value: probability value, s: significant pvalue (p< 0.001) the correlation was non-significant when comparing the activity of peroxidase and both plaque index (pli) and gingival index (gi) in group 1. a weak negative and non-significant correlation was determined for gi and a non-significant correlation for pli in group 2. results are as illustrated in the table below: table 2: correlation and p-value between periodontal parameters and peroxidase activity in group1 and group 2: periodontal parameters study groups group1, n=44 group 2, n=31 r p_value r p_value pli 0.044 0.777 ns 0.360 0.05 ns gi 0.261 0.086 ns -0.011 0.951 ns r: coefficient of correlation, p_value: probability value, pl: plaque index, gi: gingival index, ns: non– significant p_value≥ 0.05, n: number. 2. tio2 nps characterization: spectra of uv-vis absorption were used to determine tio2 nps absorption qualities. the peak was around 200 nm which points to the intensity of absorption of tio2 nps dispersion at <300 nm in the ultraviolet area of the spectrum, as shown in figure (1): groups n mean ±sd t-test p-value group1 44 242.38±137.31 2.68 0.001s group2 31 175.67±76.08 j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 14 figure 1: absorbance spectra of tio2 nanoparticles. tem was used to identify the structure and nano size measurement of tio2 nps in the samples (figure 2). the average diameter of the particle size was found to be < 30nm. figure 2: the tem pictures and size distribution of tio2 nps. the arrow shows a nanoparticle size of 28.5nm (less than 30 nm). 3. the effect of tio2 nps on peroxidase enzyme in saliva the differences in the activities of peroxidase enzyme (mean ± sd) for the studied groups are shown in table (3) below. the results conveyed that the activity of peroxidase in saliva samples from group 1 with tio2 nps was greater than the enzyme activity in samples without tio2 nps with a statistically high significance difference (p-value< 0.001), as shown in the table below. similarly, a highly significant difference was also found after comparing the enzyme activity in group 2 with and without tio2 nps. j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 15 table 3: intragroup comparison of the effect of tio2 nps on peroxidase activity in both groups. study groups group1, n=44 group1, n=31 mean± sd t-test p_value mean± sd t-test p_value with tio2 nps 304.81± 153.43 7.230 0.0001hs 213.48± 88.65 5.036 0.0001hs without tio2 nps 242.38± 137.31 175.67± 76.08 tio2 nps: titanium dioxide nanoparticles, hs: highly significant (p_value< 0.001) the activity of peroxidase enzyme in the presence of tio2 nps was compared between both groups. the results showed a high statistically significant difference (p-value< 0.001), as stated in table (4) below: table 4: intergroup comparison of the effect of tio2 nps on peroxidase activity in both groups and significance level: groups peroxidase activity in u/l mean ±sd t-test p_value group1(with tio2 nps) 304.81± 153.43 3.252 0.001hs group2 (with tio2 nps) 213.48± 88.65 figure (3) shows the action of tio2 nps (µg/ml) on the peroxidase activity (u/l) in the reaction mix of a total volume of ( 3020). it was established that tio2 nps at a concentration of 0.79 µg/ml have a higher activation effect on the enzyme activity in the mixture. at a concentration of 0.79 µg/ml of tio2 nps, peroxidase activity reached its highest activation percentage (65.93%), making this concentration of the nanoparticles the most effective concentration in this experiment as shown in figure (4). figure 3: effect of different concentrations of tio2 nps on salivary peroxidase activity. v= volume, u/l= units per liter, µg/ml= microgram per millilitre, tio2 nps= titanium dioxide nanoparticles j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 16 figure 4: percentage of activation of salivary peroxidase activity in different concentrations of tio2 nps. tio2 nps= titanium dioxide nanoparticles discussion nowadays, tio2 nps were incorporated in many products used in daily life which made it necessary to evaluate the action of this type of nanoparticle on living systems(12). the chemical evaluation revealed that tio2 nps caused an elevation in peroxidase activity. al-rubaee et al. in 2016 showed that total salivary peroxidase was activated significantly (p˂0.001) by tio2 nps13. the surface of the nanoparticles can cause changes in the form of the protein when it attaches itself to the nanoparticle surface. this change in the protein form can lead to a change in the protein's function. this changes the bio reactivity of the nanoparticles(14). many studies showed evidence of conformational changes when enzyme interacts with nps, such as a study on zinc oxide nps in which it was found that the nps modify the secondary structure of lysozyme. the enzyme keeps its catalytic activity and resists denaturation in the presence of these nps(15). in another study to determine the effect of zinc oxide nanoparticles on peroxidase enzyme activity, an inhibition action on peroxidase enzyme activity was noticed for this type of nanoparticles(16). the activity of peroxidase was found to be elevated in periodontitis compared to non-periodontitis patients, with a significant difference. similar results were obtained in another study by al-rassam et al. in 2017 (17) in which a comparison was made between salivary peroxidase activity in the chronic periodontitis group and a control group, the enzyme activity was elevated in the chronic periodontitis group compared to the control group and with a significant difference. another study found that salivary peroxidase activity significantly increases with inflammation and reduces after oral hygiene measures(18). in another study, glutathione peroxidase in saliva and gingival tissues of subjects with and without chronic periodontitis was evaluated and it was found that there was an increase in glutathione peroxidase level in saliva and inflamed gingival tissue(19). j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 17 the elevated peroxidase level in the saliva and tissue of the gingiva of patients suffering from periodontitis can be accredited to the scavenging of the redundant lipid peroxidation products at the inflammatory sites(20). also, the elevated level of reactive oxygen species (ros) formed may have caused oxidative stress, which lead to an increased need for peroxidase generation to establish the ros–ao balance to prevent tissue damage(19). in this study, a non-significant correlation between the gingival index and the activity of salivary peroxidase in group1 and group2, a similarly non-significant correlation was found between plaque index and the action of salivary peroxidase in both groups (p> 0.05). this is, in contrast, to a study by dagar et al. in 2015 (21) in which a significant correlation was found between the activity of peroxidase and pli. this difference in results could be accredited to the variation in saliva-collecting methods, the number of participants in each study, and analysis methods. in this study, tio2 nps caused an increase in the action of the peroxides enzyme. peroxidase enzyme level in the saliva of patients suffering from periodontitis was significantly higher than patients without periodontitis disease. however, more research are needed to overcome the limitations of this study. some of these limitations, such as the limited study sample size, the time constraints, and the technique-sensitive method for preparing the nanoparticle solution, can be addressed in future studies for more precise results. conclusion the solid surface of nanoparticles can induce changes in the attached protein molecule which in turn causes changes in the effect of the nanoparticles on living tissue. the titanium dioxide nanoparticles play a role in increasing the activity of salivary peroxidase within the saliva of periodontitis patients. conflict of interest: none references 1. shaddox m, walker cb. treating chronic periodontitis: current status, challenges, and future directions. clin cosmet investig dent. 2010;11:79-91. 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(crossref) file:///c:/users/huawei/downloads/telegram%20desktop/10.1039/c3cp43938k file:///c:/users/huawei/downloads/telegram%20desktop/10.26477/jbcd.v31i3.2693 file:///c:/users/huawei/downloads/telegram%20desktop/10.1590/2177-6709.22.5.067-074.oar file:///c:/users/huawei/downloads/telegram%20desktop/10.1902/jop.1967.38.6.610 file:///c:/users/huawei/downloads/telegram%20desktop/10.3109/00016356408993968 file:///c:/users/huawei/downloads/telegram%20desktop/10.1016/j.molliq.2017.06.086 file:///c:/users/huawei/downloads/telegram%20desktop/10.1186/1477-3155-11-26 file:///c:/users/huawei/downloads/telegram%20desktop/10.1021/la903118c file:///c:/users/huawei/downloads/telegram%20desktop/10.1155/2022/3664516 file:///c:/users/huawei/downloads/telegram%20desktop/10.21276/sjds.2016.4.5.1 file:///c:/users/huawei/downloads/telegram%20desktop/10.1007/s00784-008-0202-z file:///c:/users/huawei/downloads/telegram%20desktop/10.4103/0972-124x.162199 j. bagh. coll. dent. vol. 35, no. 2. 2023 talib et al 19 مرضى المصابين بالتهاب دواعم السنالتاثير جزيئات ثنائي اوكسيد التيتانيوم النانوية على فعالية انزيم البيروكسيديس في لعاب ايمان الربيعي وطبيب االسنان االختصاص ميساء مهدي ر دكتو أستاذباسمة غفوري , أستاذطبيب االسنان االختصاص ميس عالء , الباحثون: الخالصة انيوم واحدة من العديد من المواد النانوية الخلفية: لقد تم توسيع تقنية الجسيمات النانوية لتشمل العديد من جوانب الحياة الحديثة. كانت الجسيمات النانوية لثاني أكسيد التيت تفاعل لطبية الحيوية. يعتقد أن التفاعالت بين الجسيمات النانوية والبروتينات هي أساس التأثير البيولوجي للجسيمات النانوية. يتم تحفيز التي تم استخدامها في التطبيقات ا ير الجسيمات النانوية لثاني أكسيد األكسدة للعديد من المواد عن طريق إنزيمات مؤكسدة تسمى البيروكسيداز. يرتفع نشاط البيروكسيداز اللعابي في أمراض اللثة.لدراسة تأث 31مشاركًا ومجموعة غير التهاب دواعم السن مع 44مشاركًا في هذه الدراسة. مجموعة التهاب دواعم السن 75التيتانيوم على نشاط بيروكسيداز اللعاب ، تم تسجيل ستخدام المعلمات السريرية لمؤشر اللويحة ، مؤشر اللثة ، فحص عمق الجيب ومستوى عاًما لكال المجموعتين. تم ا 50إلى 35مشاركًا. تراوحت أعمار المشاركين من زيم البيروكسيديز تحت تأثير االرتباط السريري في هذه الدراسة لتحديد وجود أو عدم وجود مرض اللثة. تم جمع اللعاب غير المحفز من جميع المشاركين وتحليل نشاط إن التيتانيوم. أظهرت مجموعة التهاب دواعم السن زيادة نشاط إنزيم البيروكسيديز مقارنة بمجموعة غير التهاب دواعم السن ، ولم يظهر نشاط الجسيمات النانوية لثاني أكسيد ظهرت هذه الدراسة انه باالمكان وية.البيروكسيداز اللعابي أي ارتباط بالمعايير السريرية. تم زيادة نشاط بيروكسيداز اللعاب بواسطة جزيئات ثاني أكسيد التيتانيوم النان ت النانوية على األنسجة أن يتسبب السطح الصلب للجسيمات النانوية في إحداث تغييرات في جزيء البروتين المرتبط والذي يؤدي بدوره إلى تغيرات في تأثير الجسيما .خل لعاب مرضى التهاب دواعم السن المزمندوًرا في زيادة نشاط بيروكسيديز اللعاب دا tio2 npsالحية أو الكائن الحي. يلعب ban f.doc j bagh college dentistry vol. 27(3), september 2015 evaluation of nano restorative dentistry 8 evaluation of nano surface modification on cpti dental implant using chemical method: mechanical and histological evaluation ban nahal shukur, b.d.s. (1) raghdaa karem jassim, b.d.s., m.sc. ph.d. (2) abstract background the application of nanotechnology to biomedical surfaces is explained by the ability of cells to interact with nanometric features. the aim of this study was to consider the role of nanoscale topographic modification of cpti dental implant using chemical etching method for the purpose of improving osseointegration. materials and methods: commercial pure titanium rod was machined into 20 dental implants. each implant was machined in diameter about 3mm, length of 8mm (5mm was threaded part and 3mm was flat part). implants were prepared and divided into 2 groups according to the types of surface modification method used: 1st group (10 implant) remained without nano surface modification (control), 2nd group include (10 implant) etched with 15n h2so4 and 30% h2o2, surfaces were characterized by scanning electron microscope (sem), xray diffraction (xrd), atomic force microscope (afm), thickness measurement for the invitro experiments. while for invivo part tibia of 5 white new zealand rabbits were chosen as implantation sites. the tibia of each rabbit received two screws. biomechanical test was performed to understand the bone-implant interface, after two weeks healing periods. implants from 4animals were tested for the torque required to remove the implant from the bone and the other one animal was prepared for histological examination. results and conclusion: for in vitro results, scanning electron microscope showed that the chemical etching of ti substrate becomes highly porous and has surface consisting of nanosized pits. removal torque means value after 2 weeks of implantation mentioned that, there was a gradual increase in the removal torque mean values as a follow (m±sd): 12.625(n.cm) ± 0.517, 30.500(n.cm) ± 4.071for machined surface(x), nano chemically etched (x1) respectively. in addition, the histological analysis showed improved quality of bone in response to the nano modified screws, that the chemically treated implants shows trabeculated thread. keywords: removal torque; titanium screw; rabbit tibia; acid etching. (j bagh coll dentistry 2015; 27(3):8-14). introduction interaction between the biomaterials surface and osteoblasts is strongly associated with the biocompatibility of dental implants (1). the connection of dental implants and bone is of great interest to research on biomaterials and a significant number of studies have been carried out to investigate improvements of the bone/biomaterials interface (2). titanium (ti) is largely used as an implant biomaterial due to its mechanical properties and high in vitro and in vivo cytocompatibility, allowing direct bone-to-implant contact (3). in an attempt to increase the amount and quality of the bone-implant interface, surface treatments such as surface machining, acid etching, electro polishing, and anodic oxidation, sandblasting or plasmaspraying. these methods induce chemical modifications associated with alterations in surface topography (4). it has been shown that methods of implant preparation can significantly affect the properties of the surface and subsequently the biologic response that occur at the surface (5). chemical treatments, such as acid etching of the ti implant (1)m.sc. student. department of prosthodontics, college of dentistry, university of baghdad. (2)assist. professor. department of prosthodontics, college of dentistry, university of baghdad. surfaces, are of particular interest because they accelerate the healing process around implants. treatment of ti with a mixture of h2so4/h2o2 produces a surface that affects events of in vitro osteogenesis, resulting in an increase in bone-like nodule formation, as well as more bone-toimplant contact in vivo (6). further, recent studies have demonstrated the use of chemical oxidation to create reproducible nanopatterns on the commonly used biocompatible metals such as ti and ti alloys. by simply immersing the ti-based material in an etching solution made by mixing concentrated sulfuric acid (h2so4, a strong acid) and aqueous hydrogen peroxide (h2o2, an oxidant), it is possible to create a reproducible sponge-like network of nanopits on the surface. theses surfaces have been demonstrated to have beneficial effects on both initial and subsequent osteogenic (bone-forming) events in vitro (6). nanoporous surfaces topography tend to favor the proliferation and differentiation processes, acting directly on the selective adhesion of osteoblastic cells on the surface, which can accelerate the healing process around implants (7). j bagh college dentistry vol. 27(3), september 2015 evaluation of nano restorative dentistry 9 materials and methods 1. sample preparation commercial pure titanium grade 2plates were used as the substrate for surface modification, these plates were cut from sheet by aseissor in to small square pieces specime of (16×17×0.25mm) length, width and thickness respectively.these plates had amirror polished surface from the source.debris and contamination were removed by ultrasonic cleaning in ethanol bath for 15 minutes,followed by disilled water for 10 minutes,then the plates dried at room temperature. these plate sample were divided in to 2 groups as follow: no surface modification (mirror polish from the source) (x), nanosurface modification using chemical etching method (x1).the plates treated with a mixture consisting of equal volumes of 15n h2so4 and 30% aqueous h2o2 for 4hour under continous agitation according to the results obtained from pilot study. 2. pilot study in pilot study cpti plates treated with a mixture of equal volumes of 15n h2so4 and 30% aqueous h2o2 (8,9) for 2 times (2hr. and 4hr.). the plates placed in a beaker containing the oxidative mixture for either 2h or 4 h at room temperature under continuous agitation using magnetic stirrer (2mlh, india). then the plates washed with distilled water under continuous agitation for 15 minutes to eliminate acid residues and then dried at room temperature to be ready for testing. 3. examination of surfaces: a. examination of nanomodified surfaces x-ray phase analysis: the structure of control (x) and chemically etched (x1) were examined by x-ray diffractions using cu kα target radiation. the 2 øangles were swept from 2080° in step of one degree. b. surface roughness measurements the surface roughness of control and chemically etched plates were examined using scanning probe microscope (aa3000 angstrom advanced inc., usa). c. sem analysis the morphology of control and chemically etched plates were imaged using scanning electron microscope (sem tescan vega 111, czech) .this device was operated at30.0kvto determine the size and shape of pits in the micrographs for chemically etched sample. 4. implant preparation cpti rod (usa) was used for preparation of implants. twenty screws were machined from cpti rod; using lathe machine with cutting head coated with titanium carbide, the length of the screw was 8mm (5mm was threaded and 3mm was flat) pitch height was 1 mm, and 3mm in diameter. they have a slit in the head of 1.5mm depth and 1mm width to fit the screwdriver and torque meter during insertion and removal and slit in the center of smooth part. these screws were thoroughly ultrasonicated in ethanol bath for 20 min to remove the debris and contamination and then dried at room temperature. out of the 20 screws, ten screws were nanosurface modified using chemical etching method according to the result obtained from pilot study the implants treated with mixture consisting of equal volumes of 15 nh2so4and 30% aqueous h2o2 for four hours under continuous agitation. then implants washed with dh2o under continuous agitation for 15 minutes to eliminate acid residues and dried at room temperature. the remaining 10 implants were left as machined surfaces. the screws were sterilized with gamma irradiation dose of 1000rad using gamma cell 220 with a co60 source. the energy of the used radiation was 1.25 mev (million electron volts) with a dose rate of 90.4 rad/min and 80 cm distance between sources of radiation and dental implant, the total time is 23.49 minute. all implants were kept in their airtight plastic sheets till the operation day. 5. surgery five adult male newzealand white rabbits weighing 1.75-2kg were used. animals had free access to tap water and were fed with standard pellets and carrot. they were left for 10 days in the same environment before surgical operation. subcutaneous one dose of 10 mg ivermectin injection was given to ensure parasite free animals. the total animals no. 5 were divided in to 2 groups, first group include 4 animals for mechanical test (torque removal test). while 2nd group include 1 animals was sacrificed for histological study. four implants were implanted in the tibia, two implants (one control and one chemical treated) were implanted in the right tibia and 2 implants (one control and one chemical treated) were implanted in the left tibia consequently starting from the medial to distal metaphysic for each animal. all instruments were autoclaved at 121 c˚ and 20 bars for 30minutes before operation. the required dose of anesthesia and antibiotic was calculated by weighting each rabbit in a special balance for the animals .the animals were anaesthetized with a combination of ketamine j bagh college dentistry vol. 27(3), september 2015 evaluation of nano restorative dentistry 10 (25mg/kg) and xylazine (17.5mg/kg) intramuscularly. prior to surgery 20% of lidocaine was injected locally (1cc/1cm) into the tibia metaphase. surgical operation was performed under sterile condition and gentle surgical technique. prior to surgery, the legs were shaved, washed and decontamination with a mixture of iodine and 70% ethanol. the tibia metaphysics was exposed by incision through skin, fascia and periosteum. the flat surface on the anteriomedial aspects of the tibia was selected for implant placement. by intermittent drilling, and continuous cooling with irrigated saline holes (1.8) mm in diameter were drilled with 10 mm distance between them, enlargement of the holes were made gradually with drills from 2.2 to 2.6mm.the operation site was washed with saline to remove debris from drilling site. the sterilized implants were placed in the bed, using screw driver that fit the screw slit was completely introduced into the bone tissue and final screwing was done with torque meter (approximately 10n.cm). then the implant checked for stability. suturing of muscles was done with absorbable catgut, followed suturing of skin with skin suture. the operation site was sprayed with local antibiotic (oxytetracyclin spray).postoperatively care was performed by giving local and systemic antibiotic (20 mg/kg oxytetracycline ) for 3 days after surgery; the animals were followed daily for 2weeks. 6. mechanical testing (torque test) the same surgical instruments and anesthetic solution used in the implantation phase. for healing interval after 2weeks four animals were used for mechanical testing using removal torque meter .the animals were anesthetized with the same type and dose that used in the implantation procedure. incision was made at the lateral side of the tibia then muscles and fascia were reflected to expose the implants. after that, the muscles were removed to expose the entire tibia. a torque removal test was done by engaging the screw driver of the torque meter into the slit in the head of the implant to determine the peak torque necessary to unscrew the implant from its bed. one animal was used for histological test with optical microscope. it was injected with an overdose of anesthetic solution. cutting of the bone around the implant was performed using a disk in low rotating speed hand piece with normal saline cooling. cutting was made about 5 mm away from the head of the implant to prepare a boneimplant block for histological study. boneimplant blocks were immediately stored in 10% freshly prepared buffered formalin. results and discussion 1. x-ray diffraction of samples x-ray diffraction patterns of untreated, nanosurface modification using chemical etching methodshown in figure 1. in chemically etched plate, it appeared the same pattern of control but with decreased intensity, and did not show any anatase or rutile peaks and this agrees with ji hyun yi et al. (10) fig. 1: x-ray diffraction patterns of control and chemically treated plates 2. nanosurface feature. morphological analysis (sem) in fig. 2 a the untreated plate showed parallel grooves resulted from machining and polishing with no topographical features, whereas a distinctive texture characterized by network of nano-sized pits appearance was clearly seen on the chemically treated cpti surface for 4 hour. the average diameter of nanopits was calculated by take more than one pit and it was approximately 38.5nm fig. 2b which indicated that the use of h2o2 with acid etching has the ability to create novel nanostructures of amorphous titanium oxide on the implant surface wang et al. (11).the micrograph of the sample that chemically etched for 2 hour as shown in fig. 2 c, it showed that there were changes at the surface at low and high magnification but it j bagh college dentistry vol. 27(3), september 2015 evaluation of nano restorative dentistry 11 doesn't have the distinctive texture nanopits as the sample that treated for 4 hour. fig. 2: sem (a) control (b) chemically etched for 4 hour (c) chemically etched for 2 hour nanoroughness surface analysis afm topographies of ti surfaces before and after chemical etching (2 and 4 hour) as shown in fig (3a, b, c), grooves of mechanical polishing were observed on the untreated surface with average roughness 7.37nm as shown in fig (3 a) .in contrast, fig (3b, c) establishes that chemical treatment changes the surface topography completely, and the etched ti surface consists of nano-sized peaks and pits with increased roughness15.1nm. in chemically treated plate at 4 hours the roughness increase from 13.8 to 15.1nm. it can be observed that the grain size was nanometric in chemically treated ti plate (49.24 nm in 2 hour and 61.46 nm in 4 hour). the chemical etching increases the roughness of the surfacelead to increased surface area on the implant and promotes the opposition of bone integration of implants in bone (12). the summary of surface roughness and average diameter of grain is shown in table (1). fig. 3: afm topographies of cpti surfaces: (a) control, (b) chemically treated for 2 hour (c) chemically treated for 4 hour table 1: roughness values (nm.) obtained from afm images for all tested group group avg. diameter of grain roughness average control (untreated) 222.15 nm 7.37 nm chemically etched (2 hour) 49.24 nm 13.8 nm chemically etched (4 hour) 61.46 nm 15.1 nm b c b c a a j bagh college dentistry vol. 27(3), september 2015 evaluation of nano restorative dentistry 12 3. in vivo experiments clinical observations all animals tolerated the implantation well after surgery and moved normally within one week. one animal suffered from tibia fracture and was replaced with another rabbit. at sacrifice, no sign of gross infection, tissue reaction, or any other negative clinical observations were noted around the implant sites in any of the animals. all implants at the day of sacrifice were found stable in the bone, they could not be moved with manual force and there were no detectable peri-implant defects at the coronal aspect of any implant screw after 2weeks of healing periods. in vivo experiments included rabbit as an animal model. this is because of ease of manipulation and rapid bone healing response compared to other models (13). the tibial sites in the rabbit were chosen to mimic the clinical situation, and since the dimensions of this bone correspond well with human alveolar space. the morphologic characteristics of the rabbit tibia allow for implant fixture to engage cortical bone at its coronal aspect and marrow in the apical area (14). primary stability is considered a key factor for the clinical success of dental implants. it is determined by the density of the bone at the site, the surgical technique and the design of the implant (15). gradual size of drill until reaches the final diameter of 2.6 mm in an attempt to increase compression and thereby the stability of the implant during insertion (16). 4. mechanical testing descriptive statistics of removal torque values of machined surface dental implant, nanosurface modified dental implant by chemical etching after 2 weeks of implantation are shown in table (2). in this interval, a high torque value was needed to remove the chemically treated screw (mean value of 30.500 n.cm) and the lowest torque value was needed to remove the control (machined screw) with mean value of 12.625 n.cm. t-test was used to significant compare between means in this study. (table 3) showed a highly significant difference among two groups. table 2: removal torque mean values of all tested groups after 2 weeks of implantation group (treatment) n mean ± s.d. range control 8 12.625 ± 0.517 12-13 chemical 8 30.500 ± 4.071 25-35 table 3: t-test for the comparison between two tested group this study indicates that rough acid etched implants achieve greater resistance to reverse torque removal than machined surface implants increased surface roughness may enhance the mechanical interlocking between the macromolecules of the implant surface and the bone, resulting in a greater resistance to compression, tension and shear stress demonstrated which agree with richert et al. (17). in addition chemical etching with h2so4 and h2o2 produced nanofeature which indicated a clear relationship between cell behavior and the morphological properties of the nanotextured tibased biomaterials (18). the significance in the difference of removal torque values between machined dental implants and nanomodified chemical etched implants may be due to that nanopits might provide encouraging environment for the progenitor cells to proliferate and differentiate and large surface area. 5. histological features of implant after two weeks of implantation deposition of osteoid tissue at the apex of and the base of thread was shown in machined dental implant as shown in fig. (5 a).the tabeculated thread was seen in the ch as showed in fig. (5b). osteoblast and osteocyte can be detected as showed in fig. (5c).this is due to roughness which is of great importance in the bone stimulating. histological analysis was used in this study since it is the method of highest reliability to evaluate implant stability that can be performed at any time of the implantation, as stated by atsumi et al. (19). it is clear from the obtained results that no inflammatory reaction was observed during the experimental periods regardless of the type of implant and the duration of the implantation. this is agreed with the results of giampiero et al. (20). groups p-value sig. control & chemical etched 0.0001 hs hs highly significance j bagh college dentistry vol. 27(3), september 2015 evaluation of nano restorative dentistry 13 as conclusion; chemical method can be considered as an a suitable method for obtaining nanofeature and characterization with high removal torque mean value which was statically significance difference as compared with micron scale morphology. one might suggested that rapid bone formation response to using chemical etching is dependent on better biocompatibility of the material and on the surface topography which greatly affects the histological and biomechanical properties of the interface. acknowledgement this study was supported by al-mustansyria university/ department of physics and veterinary medicine college. references 1. brama m, rhodes n, hunt j, ricci a, teghil r, migliaccio s, et al.. effect of titanium carbide coating on the osseointegration response in vitro and in vivo. biomaterials 2007; 28: 595-608. 2. rosa al, de oliveira cs, beloti mm, xavier sp, de oliveira pt. effect of microcapsules containing tak778 on bone formation around osseointegrated implants: histomorphometric analysis in dogs. implant dent 2006; 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40: 324-35. 9. de oliveira pt, nanci a. nanotexturing of titaniumbased surfaces upregulates expression of bone sialoprotein and osteopontin by cultured osteogenic cells, biomaterials 2004; 25(3): 403-13. 10. ji-hyun yi, bernard c, variola f, zalzal sf, wuest jd, rosei f, nanci a. characterization of a bioactive nanotextured surface created by controlled chemical oxidation of titanium. science direct 2006; 600: 4613–21. 11. wang xx, hayakawa s, tsuru k, osaka a. bioactive titania gel layers formed by chemical treatment of ti substrate with a h2so4/hcl solution.biomaterial 2002; 23:1353-57. 12. albrektsson t, wennerberg a. oral implant surfaces: part 1–review focusing on topographic and chemical properties of different surfaces and in vivo responses to them. int j prosthodont 2004; 17(5): 536-43. 13. dahlin c, sennerby l, lenkholm u, linde a, nyman s. generation of new bone around titanium implant using membrane technique: an experimental study in rabbits. int j oral maxillofac implant 1989; 4(1):1925. 14. sennerby l, meredith n. resonance frequency analysis: measuring implant stability and osseointegration. compend contin educ dent 1998; 19: 493-8. 15. friberg b, jemt t, lekholm u. early failures in 4,641 consecutively placed brånemark dental implants: a study from stage 1 surgery to the connection of completed prostheses. int j oral maxillofac implants1991; 6: 142-6. 16. sung-am cho, kyung-tae park. the removal torque of titanium screw inserted in rabbit tibia treated by dual acid etching. biomaterials 2003; 24: 3611–17. 17. richert l, vetrone f, yi j-h, zalzal sf, wuest jd, rosei f, nanci a. surface nanopatterning to control cell growth. adv mater 2008; 20:1488-92. fig. 5-b: histological view for chemically etched dental implant shows thread (arrow) h&e×10. fig. 5-c: magnifying view for bone trabeculae (bt) shows osteocytes (arrow head) h&e×20. fig. 5-a: osteoid tissue (ost) deposits at the base of thread h &e ×20. j bagh college dentistry vol. 27(3), september 2015 evaluation of nano restorative dentistry 14 18. he j, zhou w, zhou x, zhong x, zhang x, wan p, zhu b, chen w. the anatase phase of nanotopography titania plays an important role on osteoblast cell morphology and proliferation. j mater sci mater med 2008; 19(11): 3465-72. 19. atsumi m, park s, wang h. methods used to assess implant stability: current status. int j oral maxillofac implant 2007; 22: 743-54. 20. giampiero c, zeina m,adriano p, antonio s. removal torque and istomorphometric investigation of 4 different titanium surfaces: an experimental study in the rabbit tibia. international j oral maxillofac implants 2000; 15(1): 668-74. الخالصة تانة المیكانیكیة او االنسجام وقد تم تحقیق النجاح السریري لیس فقط بسبب الم.توفر زراعة االسنان طریقة العالج الفریدة الستبدال االسنان المفقودة:المقدمة .عة ولكن ایضا بسبب الخصائص االخرى مثل خصائص السطحرالحیوي لمادة الز .في تحسین االندماج العظمي باستخدام الطریقة الكیمائیة النظر في دور التعدیل النانوي لسطح زرعات االسنان من التیتانیوم النقي التجاري: الھدف خمسة ملیمات منھا ملولب ( ملم ٨ملم وطول ٣كل غرسھ صنعت بقطر ) .غرسھ ٢٠(ضیب التیتانوم النقي تم تحویره ومكننتھ الى ان ق: المواد و االدوات ).وثالث ملیمات ملساء دون تعدیل السطح ) زرعات١٠(تركت المجموعة االولى:وفقا لطرق تعدیل السطح المستخدمة مجموعتین الى تم تحضیر وتقسیم الغرسات .اوكسید الھیدروجین%٣٠مع حامض الكبریتیكن من ١٥حفرت باستخدام)زرعات١٠(المجموعة الثانیة ).لسیطرةا(نانو مجھر المسح , قیاس السمك,المجھرالقوة الذریة, , ولمعرفة التغیرات التي تحدث على السطح ولمعرفة التحلیل الھیكلي تم استعمال فحص انحراف االشعة السینیة نب امن االر) ٥(ُاختیر عظم الساق ل .غرسة٢٠أما بالنسبة للدراسة التجریبیة على الحیوانات فقد تمت عن طریق زراعة . المجھر الضوئي, اإللكتروني ولفھم السطح البیني للعظم و الغرسة اجري الفحص االحیامیكانیكي .لولبین الساق الیمنى و الیسرى من كل ارنب م وضعت في,النیوزلندیة البیضاء مكانا للزراعة .ألغراض إختبار األنسجة بالمجھر الضوئيواحد منھا إلجراء الفحص المیكانیكي بواسطة فحص عزم التدویر بینما استخدم اربعة.من مدة الشفاءاسبوعین بعد ح االلكتروني ان الحفر الكیمیائي للقاعدة التیتانیوم اصبحت ذات مسامات عالیة ولھا سطح یتكون من حفر اظھر مجھر المس,نتائج الدراسة الخارجیة : النتائج ٤.٠٧١±٣٠.٥٠٠, ٠.١٥٧±١٢.٢٦٥: كان ھناك زیادة تدریجیة في قیم متوسط عزم التدویركمایلي,بعد اسبوعین من الزرعنتائج عزم التدویر.نانونیة الحجم غرسات المعدلة نانویا بشكل ایجابي للوباالضافة الى ذللك اظھر التحلیل النسیجي تحسین نوعیة العظم . لى التوالي عفورة كیمائیا للمجامیع السیطرة والمح .اظھرت تكونا عظمیابالطریقة الكیمائیة وان الزرعات المعالجة . ban.doc j bagh college dentistry vol. 27(2), june 2015 congenitally missing pedodontics, orthodontics and preventive dentistry148 congenitally missing and supernumerary teeth among a group of 3-12 years old children with cleft lip and/ or palate in iraq zainab j. ja'far, b.d.s., m.sc. (1) ban ali salih, b.d.s., m.sc. (2) abstract background: there are many congenital anomalies associated with cleft lip and/or palate. this research is to study the prevalence of congenitally missing teeth and supernumerary teeth in this population group. materials and method: one hundred eight cleft lip and/or palate iraqi patients had participated in this study (57 male, 51 female), 3-12 years of age. 26 of them had orthopantomogram were within (6-12) years of age were inspected for congenitally missing teeth and supernumerary teeth. patients whom age range 3-5 years were checked for the congenitally missing teeth by clinical examination with strongly insisting the teeth were not missed due to caries or trauma. results: there were 19(73.076%) patients with 41 congenitally missing teeth for the 26 patients within 6-12 years age group who were with orthopantomogram, while there were 20(37.037%) patients with 32 congenitally missing teeth for the 54 patients within 3-5 years of age who were not indicated for orthopantomogram. there were (22) patient with (27) supernumerary teeth. conclusion: the most frequently congenitally missing tooth was the permanent upper lateral incisor, on the other hand the tooth most frequently noted as extra tooth was the primary lateral incisor. majority of them were with cleft lip and palate. key words: cleft lip and / or palate, congenitally missing teeth, supernumerary teeth. (j bagh coll dentistry 2015; 27(2):148-153). introduction numerical abnormalities are not uncommon in the dentition of the normal population, it is reasonable to consider cleft and normal populations have the backgrounds with similar numerical variations (1,2). congenitally missing teeth( c.m.t.), supernumerary teeth (s.n.t.) have been shown to occur more frequently in cleft lip and/or palate children than normal children(3,4).millet and wellbury said that on the cleft side, the lateral incisor is either absent, of abnormal size and/or shape, hypoplastic or as two conical teeth on either side of the cleft (5). kraus et al, 1966 found 8 cases of s.n.t. in 25 clp group (6). the site of s.n.t. was between the central incisor and cuspid in all patients (7). materials and methods one hundred eight cl (p) iraqi patients had participated in this study (57 male, 51 female), 312 years of age. approval was achieved from ministry of higher education and scientific research, and ministry of health for examining the cleft patients. the presence of c.m.t. or s.n.t. had been assessed on o.p.g. if present (26) who were within (6-12) years of age were inspected for c.m.t. and s.n.t. (1)lecturer. department of pedodontics and preventive dentistry, college of dentistry, university of baghdad (2)professor, department of pedodontics and preventive dentistry, college of dentistry, university of baghdad patients whom age range 3-5 years were checked for the c.m.t. by clinical examination with strongly insisting the teeth were not missed due to caries or trauma. chi-square was used to assess two categorical variables (frequency of data), such as the presence of c.m.t. according to the type of cleft. results congenitally missing teeth patients with o.p.g. who were within (6-12) years of age were inspected for c.m.t. and the results were demonstrated in table (1). the highest percentage (30.77%) had one or two c.m.t. it is evident from the table that there were 19 patients with 41 c.m.t. in the sample that the o.p.g. was available. patients without o.p.g. who were within (3-5) years of age were inspected for c.m.t. clinically and the results were demonstrated in table (2). the highest percentage (50%) had one c.m.t. it is evident from the table that there were 20 patients with 32 c.m.t. in the sample that the o.p.g. was not indicated. table (3) demonstrates the presence or absence of hypodontia in different cleft types in the sample with o.p.g, the highest value for the presence of hypodontia is for the clp with statistically non significant difference (p=0.11). it reveals that 19 from the 26 patients examined are with hypodontia. table (4) demonstrates the presence or absence of hypodontia in different cleft types in j bagh college dentistry vol. 27(2), june 2015 congenitally missing pedodontics, orthodontics and preventive dentistry149 the sample without o.p.g, the highest value for the presence of hypodontia is for the clp with statistically highly significant difference (p=0.0009). it reveals that 20 from the 54 patients examined are with hypodontia. table (5) demonstrates the different number of c.m.t. in different cleft types in the sample with o.p.g. the highest accounts are for the clp patients with one or two c.m.t. with statistically non significant difference. table (6) demonstrates the different number of c.m.t. in different cleft types in the sample without o.p.g. the highest accounts are for the clp patients with one then two c.m.t. with statistically non significant difference. table (7) illustrates the frequency and percentage of different types of c.m.t. in the sample with o.p.g. the highest percentage is for the permanent upper lateral incisor with statistically highly significant difference (p=0.001). table (8) illustrates the frequency and percentage of different types of c.m.t. in the sample without o.p.g. the highest percentage is for the primary upper lateral incisor with statistically highly significant difference (p=0.0001). supernumerary teeth in the selected sample which comprise (108) patients, there were (27) supernumerary teeth found in (22) patient. table (9) demonstrates the distribution of patients with no, one, or two s.n.t. table (10) demonstrates the frequency and percentage of patients in every type of s.n.t. in the selected sample. the highest percentage was the primary upper lateral incisor (9.2%). table (11) demonstrates the frequency and percentage of teeth in every type of s.n.t. in the selected sample. the highest percentage was (40.74%) for the primary upper lateral incisor. table (12) demonstrates the number of s.n.t. according to patient with or without o.p.g.. there was a statistically non significant difference (p=0.97). table (13) demonstrates the number of s.n.t. according to type of cleft. there was a statistically significant difference (p=0.03). table 1: number and percentage of patients with o.p.g. had different number of c.m.t. patients with o.p.g. c.m.t. (no.) % no. 26.92 7 0 30.77 8 1 30.77 8 2 3.85 1 4 3.85 1 5 3.85 1 8 100 26 total table 2: number and percentage of patients without o.p.g. had different number of c.m.t. patients without o.p.g. c.m.t. (no.) % no. 50 10 1 45 9 2 4 1 4 100 20 total table 3: presence or absence of hypodontia in different cleft types of the sample with o.p.g. hypodontia diagnosis cl cp clp total no. % no. % no. % no. % present 1 3.9 2 7.7 16 61.5 19 73.1 not present 2 7.7 3 11.6 2 7.7 7 27 total 3 11.6 5 19.3 18 69.2 26 100 x²=7.4 df=2 p=0.11*(ns) non significant. j bagh college dentistry vol. 27(2), june 2015 congenitally missing pedodontics, orthodontics and preventive dentistry150 table 4: presence or absence of hypodontia in different cleft types of the sample without o.p.g. hypodontia diagnosis cl cp clp total no. % no. % no. % no. % present 2 3.7 0 0 18 33.3 20 37 not present 5 9.3 15 27.8 14 25.9 34 23 total 7 13 15 27.8 32 59.2 54 100 x²=14.10 df=2 p=0.0009*(hs) *highly significant. table 5: different number of c.m.t. in different cleft types in the sample with o.p.g. c.m.t. (no.) diagnosis cl cp clp total 1 1 0 7 8 2 0 1 7 8 4 0 1 0 1 5 0 0 1 1 8 0 0 1 1 total 1 2 16 19 x²=13.9 df=8 p=0.17(ns)* non significant table 6: different number of c.m.t. in different cleft types in the sample without o.p.g. c.m.t. (no.) diagnosis cl cp clp total 1 1 0 9 10 2 1 0 8 9 4 0 0 1 1 total 2 0 18 20 x²=0.123 df=4 p=0.055(ns)* non significant table 7: distribution of different types of c.m.t in the sample with o.p.g. frequency percentage permanent upper lateral incisor 25 60.98 permanentlower second premolar 6 14.63 permanent upper second premolar 6 14.63 permanent upper central incisor 3 7.32 permanent lower central incisor 1 2.44 total 41 100 x²=66.5 df=4 p=0.001(hs)*** highly significant table 8: distribution of different types of c.m.t in the sample without o.p.g. frequency percentage primary upper lateral incisor 25 78.125 primary upper central incisor 5 15.625 primary lower central incisor 2 6.25 total 32 100 x²=76.8 df=2 p=0.0001(hs) ***highly significant table 9: distribution of patients with no, one, or two s.n.t. s.n.t. no. no. of patients % 0 86 79.6 1 17 15.7 2 5 4.6 total 108 100 j bagh college dentistry vol. 27(2), june 2015 congenitally missing pedodontics, orthodontics and preventive dentistry151 table 10: type of s.n.t. in the selected sample. s.n.t-type no. of patients % no 86 79.8 permanent mesodens 6 5.5 permanent lateral incisor 2 1.8 primary mesodens 2 1.8 primary lateral incisor 10 9.2 primary central incisor 1 0.9 primary lower central 1 0.9 total 108 100 table 11: number and percentage of types s.n.t. % no. of teeth s.n.t. type 11.11 3 primary mesodens 29.63 8 permanent mesodens 7.40 2 permanent upper lateral 40.74 11 primary upper lateral 3.70 1 primary upper central 7.40 2 primary lower centrals 100 27 total table 12: number of s.n.t. according to patient with or without o.p.g. s.n.t. no. o.p.g yes no total no.* % no.* % no.* % 0 21 19.40 65 60.20 86 79.60 1 4 3.70 13 12.00 17 15.70 2 1 0.90 4 3.70 5 4.60 total 26 24.10 82 75.90 108 100 x²= 0.05 df= 2 p=0.97(n.s)** * number of patients, **non significant table 13: number of s.n.t. according to type of cleft. s.n.t. no. diagnosis cl cp clp total no.* % no.* % no.* % no.* % 0 7 6.50 24 22.20 55 50.90 86 79.60 1 6 5.60 2 1.90 9 8.30 17 15.70 2 1 0.90 1 0.90 3 2.80 5 4.60 total 14 13.00 27 25.00 67 62.00 108 100 x²= 10.08 df= 4 p=0.03(s)** *number of patients, **significant discussion congenitally missing teeth the presence of c.m.t. had been assessed on o.p.g. if present (n=26), this proportion was low because the children under 6 years of age were not be permitted to take an o.p.g., and this age group constituted a high percentage from the selected sample (50%), also some centers from which the sample collected had no o.p.g. machine, so only this number of patients were able to take this type of x-ray and their age ranges 6-12 years. there were 19(73.076%) patients with 41 c.m.t. for the 26 patients within 6-12 years age group who were with o.p.g., while there were 20(37.037%) patients with 32 c.m.t. for the 54 patients within 3-5 years of age who were not indicated for o.p.g. these are in accordance with ranta and rintala (8)shapira et al (9) for the first; and with hellquist et al (10); ranta et al (11); and abd.rahman et al (12) for the second; while these values are higher than that of dahllöf et al (13); aljanabi (14); and kirzioğlu et al. (15). this difference may be due to different racial and ethnic origin, genetic factors, method of examination, sample size and homogenicity, age groups, in addition to surgical procedures. according to the type of cleft, the majority of the 6-12 years old patients with c.m.t. are under the diagnostic criteria of clp(61.5%), followed by patients with cp(7.7%), and the least account j bagh college dentistry vol. 27(2), june 2015 congenitally missing pedodontics, orthodontics and preventive dentistry152 is for the cl (9.3%) with statistically non significant difference (p=0.11). this result agree with fishman, 1970(16), while for patients within 3-5 years of age who were without o.p.g. the majority also (33.3%) were clp patients, followed by cl (3.7%) and no c.m.t. were observed in isolated cp. these results agree with kirzioğlu et al (15). the most frequently congenitally missing teeth were the upper lateral incisor (25 primary teeth, 25 permanent teeth), then the upper and lower second premolar (6) and the primary upper central incisor (5)come next, then the permanent upper central incisor (3 teeth), primary lower central incisor (2 teeth), and the least is for the permanent lower central incisor(1 tooth). these outcomes are similar to that of jones et al. (17,18). while these results disagreed with al-wahadni et al. (19). numerical abnormalities are not uncommon in the dentition of the normal population, where maxillary and mandibular second premolars are the most commonly missing permanent teeth (2). it is reasonable to consider cleft and normal populations have the backgrounds with similar numerical variations. thus, these findings suggest that the maxillary lateral incisors are missing more often than they are in normal populations. millet and wellbury said that on the cleft side, the lateral incisor is either absent, of abnormal size and/or shape, hypoplastic or as two conical teeth on either side of the cleft (5). many theories have been advanced attempting to explain why so many teeth are missing in children with clefts. these theories include multiple genetic and environmental factors, mesenchyme deficiency, and direct effect of cleft on the primordial tissue related to the development of the lateral incisor (20). nutritional factors due to an initial lack of bone tissue around the tooth germs or a congenitally inadequate blood supply to the area in question may, instead, be considered to affect the dental development in the cleft area (21). viral and bacterial infection may well be a more important etiologic factor than heredity, but only more detailed research can confirm or deny this possibility (7). some consider the same etiologic factor or factors seem to be responsible both for the formation of cleft and for advanced hypodontia in children with clp which are likely result of a prenatal injury interacting with a poorly buffered genotype (22). dixon suggested that surgical treatment of the cleft during the period of hard tissue formation of the permanent teeth may affect their development in some cases (23). hypodontia is believed to be a consequence of physical obstruction or description of dental lamina, space limitation, functional abnormalities of the dental epithelium, and failure of initiation of the underlying mesenchyme (24). supernumerary teeth (s.n.t.) from the 108 cleft children examined, there are 22(20.3%) children with 27 s.n.t. five from these 22 patients are with 2 s.n.t., while the remaining 17 are with one s.n.t. for each child. this finding is similar to that of dahllöf et al (13). at the same time it is lower than that recorded by ribeiro et al (25), while it is higher than that of aljanabi (14). this difference may be due to different racial and ethnic origin, genetic factors, method of examination, sample size and homogenicity, age groups, in addition to surgical procedures. the tooth most frequently noted as extra tooth was the primary lateral incisor (11 teeth), then the primary mesodens (8 teeth), then the permanent mesodens (3 teeth),then permanent upper lateral incisor and primary lower central (2 teeth for each)and the least frequency for the primary upper central incisor (1 tooth). this outcome is in agreement with fishman (16); jones et al. (17,18). the frequency of s.n.t. in the primary dentition is more than that in the permanent dentition, which is in accordance with abdrahman (12). by using the o.p.g., from the 26 patients examined, there were 5(4.6%) children with (6) s.n.t. compared to 82 children without o.p.g. in which there are 17(15.7%) with (21) s.n.t. with statistically non significant difference (p=0.97). according to the type of cleft, clp had the highest number of s.n.t.(12), followed by cl(7), and the least frequency was for the cp(3) with statistically significant difference. these findings agree with that recorded by fishman (16). but disagree with berkowitz (26). this result can be explained by the alveolar ridge in isolated cp is not disturbed by the cleft deformity, so it will not affect the tooth germ in its developmental period, as it has been argued that the clefting process splits the tooth germ into two separate teeth (27). jones et al 1994 and 2004 said that there is a significant increase in the frequency of s.n.t., often with complete unilateral or bilateral clefts. insisting on the somatic effect, inoue, 1915 supported the idea that the development of a third incisor is attributed to incomplete fusion of the germ of the second incisor. the length of dental lamina is regarded as a determining factor for the number of teeth in the region. dental lamina is present before the several parts coalesce to form the maxilla. in instances, in which malformation arise, as in case of cleft palate, a lateral incisor cast into the cleft can be split to form a j bagh college dentistry vol. 27(2), june 2015 congenitally missing pedodontics, orthodontics and preventive dentistry153 supernumerary tooth, or be obliterated to be congenitally absent or markedly malformed (27). references 1. silverman ne, ackerman jl. oligodontia: a study of its prevalence and variation in 4032 children. j dent child 1979; 46: 470-7. 2. zhu jf, marcushamer m, king ld, henry rj. supernumerary and congenitally absent teeth.a literature review. j clin pediatr dent 1996; 20:87-95. 3. hellquist r, linder-aronson s, norling m, ponten b, stenberg t. dental abnormalities in patients with alveolar clefts, operated upon with or without primary periosteoplasty. eur j orthod 1979; 1: 169-80. 4. ranta r, stegars t, rintala a. correlations of hypodontia in children with isolated cleft palate. cleft palate j 1983; 20:163-5. 5. millet d, wellbury r. cleft lip and palate cl (p). in orthodontics and paediatric dentistry, colour guide; 2000. 6. kraus bs, jordan re, pruzansky s. dental abnormalities in the deciduous and permanent dentition of individuals with cleft lip and palate. j dent res 1966; 45:1736-46. 7. jordan re, kraus bs, neptune cm. dental abnormalities associated with cleft lip and/or palate. cleft palate j 1966; 3: 22-55. 8. ranta r and rintala a. tooth anomalies associated with congenital sinuses of the lower lip and cleft lip/palate. angle orthod 1982; 52(3): 212-21. 9. shapira y, lubit e, kuftinec mm, stom d. hypodontia in children with various types of clefts. angle orhtod 2000; 70(1):16-21. 10. hellquist r, linder-aronson s, norling m, ponten b, stenberg t. dental abnormalities in patients with alveolar clefts, operated upon with or without primary periosteoplasty. eur j orthod 1979; 1:169-80. 11. ranta r, stegars t, rintala a. correlations of hypodontia in children with isolated cleft palate. cleft palate j 1983; 20:163-5. 12. abd. rahman n, abdullah n, samsudin ar, naing l, sadiq ma. dental abnormalities and facial profile abnormality of the non-syndromic cleft lip and palate children in kelantan. malaysian j medical sci 2004; 11(2): 41-51. 13. dahllöf g, ussisoo-joandi r, ideberg m, modeer t. caries, gingivitis, and dental abnormalities in preschool children with cleft lip and/or palate. cleft palate j 1989; 26(3): 233-7, discussion 237-8. 14. al-janabi mf. clinical study on cleft lip and/or palate patients (a descriptive epidemiological comparative and cross-sectional study). a master thesis, department of orthodontics, university of baghdad; 2001. 15. kirzioğlu z, sentut tk, ertürk mso, karayilmaz h. clinical features of hypodontia and associated dental anomalies: a retrospective study. oral diseases 2005; 11: 399-404. 16. fishman ls. factors related to tooth number, eruption time and tooth position in cleft palate individuals. j dent child 1970; 37: 303-6. 17. jones je, nelson cl, sadove am, hennon dk. multidisciplinary team approach to cleft lip and palate management. . in mcdonald re, avery dr: dentistry for the child and adolescent. 6th ed. st. louis philadelphia: sydney toronto co.; 1994. 18. jones je, sadove am, dean ja, huebener dv. multidisciplinary team approach to cleft lip and palate management. in mcdonald re, avery dr, dean ja: dentistry for the child and adolescent. 8th ed. st louis, mossouri: mosby; 2004. 19. al-wahadni a, abu-alhaija e, al-omari ma. oral disease status of a sample of jordanian people aged 10-28 with cleft lip and palate. cleft palatecraniofacial j 2005; 42(3): 304-8. 20. ross rb, johanston mc. cleft lip and palate. baltimore, md: williams and wilkins co.; 1972. p. 81-82. 21. olin wh. dental anomalies in cleft lip and palate patients. angle orthod 1964; 34:119-23. 22. bailit hl, doykos jd, swanson lt. dental development in children with cleft palates. j dent res 1968; 46: 664. 23. dixon da. defects of the structure and formation of teeth in person with cleft palate and the effect of reparative surgery on the dentsl tissues. o.s, o.m, o.p 1968; 25(3): 435-46. 24. nunn jh, carter ne, gillgrass tj, hobson rs, jepson nj, meechan jg, nohl fs. the interdisciplinary management of hypodontia: background and role of paediatric dentistry. br dent j 2003; 194(5): 245-8. 25. ribeiro ll, neves lt, costa b, gomide mr. dental anomalies of the permanent lateral incisors and prevalence of hypodontia outside the cleft area in complete unilateral cleft lip and palate. cleft palatecraniofacial j 2003; 40(2):172-5. 26. berkowitz s. state of the art in cleft palate orofacial growth and dentistry. am j orthod 1978; 74(5):56476. 27. millhon ja, stafne ec. incidence of supernumerary and congenital missing lateral incisor teeth in eightyone case of harelip and cleft palate. am j orthod & o surg (sec o. surg) 1941; 27:599-604. :الخالصة وھذا البحث لدراسة انتشار االسنان المفقودة والدیا واالسنان الزائدة والدیا . أو شق الحنك الوالدي \توجد الكثیر من العیوب الخلقیة المصاحبة لشق الشفة و: المقدمة .في ھذا النوع من الناس 12-3تتراوح اعمارھم من ) من االناث 51, من الذكور 57(و شق الحنك الوالدي أ \طفل یعانون من شق الشفة و 108شارك في ھذه الدراسة : األدوات والطریقة بینما . وتم فحص االشعة لتسجیل االسنان المفقودة والدیا والزائدة والدیا, سنة 12-6توفرت لھم األشعة الوجھیة والذین ھم بأعمار ) طفل 26(البعض منھم. سنة أكید ال یمكن أخذ االشعة الوجھیة لھم بسبب تأثیر االشعاع لذلك تم الفحص السریري لتسجیل االسنان المفقودة والدیا والزائدة والدیا مع الت 5-3األطفال من عمر .على أن االسنان المفقودة لم یفقدھا الطفل نتیجة التسوس او الحوادث سنة من العمر ممن توفرت لنا صورھم الشعاعیة بالتصویر 12-6طفل الذین بین 26سن مفقود والدیا من ال 41ى لدیھم من المرض%) 73.076(19ھناك : النتائج سنة من العمر ممن ال تتوفر لنا صورھم الشعاعیة 5-3طفل الذین بین 54سن مفقود والدیا من ال 32من المرضى لدیھم %) 37.037( 20بینام ھناك , الوجھي .سنا) 27(مریضا لدیھم اسنان زائدة والدیا 22وھناك . وجھي وذلك للخوف علیھم من التأثیر اإلشعاعيبالتصویر ال والسن األكثر تھورا كسن زائد والدیا كان القاطع اللبني الثاني في الفك , السن األكثر تھورا كسن مفقود والدیا كان القاطع الثاني الدائمي في الفك األعلى: الخاتمة كثر الحاالت كانت شق الشفة والحنكأ. األعلى abdul-karim final.doc j bagh college dentistry vol. 26(2), june 2014 the effect of waterlase restorative dentistry 1 the effect of waterlase laser and herbal alternative, green tea and salvadora persica (siwak) extract on push-out bond strength abdul-kareem jassim al-azzawi, b.d.s., m.sc. (1) abstract background: the bond strength of root canal sealers to dentin was important for maintaining the integrity of the seal in root canal filling in both static and dynamic situations. in a static situation, it should eliminate any space that allowed the percolation of fluids between the filling and the wall while in a dynamic situation; it was needed to resist dislodgement of the filling during subsequent manipulation. materials and methods: forty mandibular premolars were selected for this study. all canals were instrumented using protaper rotary instruments. instrumentation was done with copious irrigation of 5.25% sodium hypochlorite. roots were randomly divided into four groups according to the type of cleaning and method of root canal irrigation (ten teeth for each group): group a. the root canals were irrigated with 5 ml of 17% of edta for 1 minute and 5 ml of 5.25% naocl. group b. cleaning with waterlase laser. group c. the root canals were irrigated with 5 ml of 5mg/ml of siwak (salvadora persica) extract for one minute. group d. the root canals were irrigated with 5 ml of 5% of green tea (camellia sinensis) extract for one minute. all groups were rinsed with distilled water and then obturated with cold lateral condensation technique and i root sp sealer (bioceramic sealer, the roots then stored in moist environment at 37°c for one week. three horizontal sections were prepared at a thickness of 1 mm ±0.1 in the apical, middle and coronal parts of each root. the test specimens were subjected to the push-out test method using a universal test machine that carried 1-mm, 0.5mm and 0.3-mm plungers for coronal, middle and apical specimens, respectively. the loading speed was 0.5 mm/ min. the computer showed the higher bond force before dislodgment of the filling material. these forces were divided by the surface area to obtain the bond strength in mpa. results: in all groups the mean value of push-out strength was greatest in apical area and least in coronal area and the middle area was in between, except in waterlase the middle area showed the least mean push-out strength. conclusion: herbal extracts used in this study (siwak and green tea) can be used safely as an intra-canal irrigant for smear layer removal with efficiency that is comparable with conventional synthetic materials (edta) and more complicated methods (waterlase). key words: waterlase, siwak, green tea, push out test. (j bagh coll dentistry 2014; 26(2):1-6). introduction the bond strength of root canal sealers to dentin was important for maintaining the integrity of the seal in root canal filling in both static and dynamic situations. in a static situation, it should eliminate any space that allowed the percolation of fluids between the filling and the wall while in a dynamic situation; it was needed to resist dislodgement of the filling during subsequent manipulation (1). the physical properties necessary for this function include adaptation and adhesion of the filling material to the root canal wall, because gutta-percha does not directly bond to the dentin surface and ideally, the sealer should be capable of producing a bond between core material and dentin wall (2). cleaning of both the root canal and the dentinal tubule system, as well as proper filling of the canal, are essential procedures for the success of root canal treatment. even when treatment is adequate, failure may occur within the canal. thus, disinfection and shaping of the canal with a combination of chemical agents and endodontic instruments play an important role in the success of endodontic therapy (3-5). (1)professor. department of conservative dentistry. college of dentistry, university of baghdad. sodium hypochlorite (naocl) has been widely used as an irrigant since its introduction in endodontics by walker in 1936. sodium hypochlorite solutions require careful handling and several factors are associated with its safety concerns. the main disadvantages of sodium hypochlorite are unpleasant taste, high toxicity, corrosive to instruments, inability to remove smear layer and reduction in elastic modulus and flexural strength of dentin (6,7). herbal or natural products have been used in dental and medical practice for thousands of years and have become even more popular today due to their high antimicrobial activity, biocompatibility, anti-inflammatory and anti-oxidant properties (8). green tea made solely from the leaves of camellia sinensis and the antimicrobial activity is due to inhibition of bacterial enzyme gyrase by binding to atp b sub unit. green tea exhibits antibacterial activity on e-faecalis plaknotic cells. it is also found to be a good chelating agent (9-10). salvadora persica (miswak, siwak) was chewing sticks contain trimethyl amine, salvadorime chloride and fluoride in large amounts. fifteen percent alcoholic extracts of it has maximum antimicrobial action. it can be used as a substitute for sodium hypochlorite and chlorhexidine as root canal irrigant (1113). j bagh college dentistry vol. 26(2), june 2014 the effect of waterlase restorative dentistry 2 the remaining of smear layer after rotary or hand instrumentation not only contains infected tissue, but can seal infection within dentinal tubules. scanning electron microscopy shows how treatment with waterlase radial firing tips (rft) leaves canal walls free of smear layer, and opens dental tubules, allowing ysgg laser energy to penetrate and destroy bacteria. this study is conduct to compare the effect of newer method waterlase laser to remove smear layer and usage of herbal extracts, green tea and salvadora persica (siwak), as irrigation solution with standardized method 17%edta on push strength of bioceramic sealer. materials and methods sample preparation forty freshly extracted mandibular premolars with straight single roots and close apices were used in this study. after extraction, all teeth were stored in 0.1% thymol solution at room temperature, root surfaces were verified any defects and cracks. the length of root was determined by digital calliper and marker to 14 mm and by using diamond disk the root sectioned perpendicular to its long axis to provide straight line access for canal preparation and filling procedure. the pulpal tissue was removed by using barbed broach and copious amount irrigation of 5.25% naocl. the exact location of apical foramen and potency of canals were verified by insertion of no.15 k file into canal until it was visualised at apical foramen. the working length was established by subtracting 1mm from this measurement. the root canal was flooded with 5.25%naocl and instrumented by protaper rotary system (sx_f3) at speed 500rpm and 1 n/c torque. sample grouping the roots were randomly divided into four groups (n=10) according to type of cleaning and method of root canal irrigation. group a. the root canals were irrigated with 5 ml of 17% of edta for 1 minute and 5 ml of 5.25% naocl followed by 5ml distilled water. group b. cleaning with waterlase laser. first step use rft2 to clean apical and coronal 2/3 partially. after place the tip into hand piece select setting, fill the canal with sterile solution and then insert rft2 in root canal 1mm short of the apex. activate laser and start moving the tip coronally at approximately 1mm/s and maintain in contact with the side surface of canal wall coronal and apical movement, repeat this manner twice to ensure canal has been cleaned. the second step use rft3 to clean the coronal 2/3. adjust the tip to about 9 mm and clean in the same manner of first step. group c. the root canals were irrigated with 5 ml of 5mg/ml of siwak (salvadora persica) extract for one minute followed by 5 ml distilled water. group d. the root canals were irrigated with 5 ml of 5% of green tea (camellia sinensis) extract for one minute followed by 5 ml distilled water. salvadora persica (miswak or siwak) preparation sticks of siwak (s. persica) were incubated at 37⁰c for 24 hrs. each stick was cut with sharp knife to small pieces then ground with food grinder into very fine powder, 250 gm of s. persica powder was taken and put in a beaker to which one litter of sterilized distilled water was added. t he liquid was left to boil at 100⁰c for 15 minutes in closed container. after bench cooling, the liquid was filtered using filter paper (no.1), and solution left to dry in an incubator at 37⁰c for 24 hrs, to allow complete evaporation of water and obtain powder of miswak. the powder was collected and kept in tightly closed glass container and kept in refrigerator until use (14). camellia sinensis (green tea) preparation five grams of the selected dry green teas leaf, steeped for 1.52 minutes in 100 ml of distilled water. the coolest brewing temperature was below 70˚c.the mixture was purified to obtain the 5% concentration solution of green tea (15). after irrigation all samples were obturated by cold gutta percha (lateral condensation technique) and i root sp sealer (bioceramic sealer). the canal of each root was dried with paper point size f3. the master cone of gutta percha size 30 was adjusted to working length with tug back. after remove the syringe cap, attached an intra canal tip securely. the flexible intra canal tip can be bent to facilitate access. insert the tip of the syringe into deepest part of root canal, gently and smoothly dispense i root sp sealer into the apex of root canal by compressing the barrel of the syringe and continue filling the root canal while withdrawing the intra canal tip and then the master gutta percha cone was inserted to correct position. the previously checked finger spreader size 20 was inserted between master cone and the canal wall used firm pressure to within (1-2mm) from working length. when spreader no inter more than 2mm, access gutta percha was removed with heated instrument to level 1mm higher than the coronal end of the root and vertically condensed with root j bagh college dentistry vol. 26(2), june 2014 the effect of waterlase restorative dentistry 3 canal plugger so gutta percha was obturated the entire canal up to canal terminus. the gutta-percha was removed at 1 mm below the orifice, and the canal orifice was sealed with glass ionomer cement to serve as a barrier to the ingress of fluids. all obturated roots of all groups were wrapped in saline moistened gauze in closed plastic vial allowing the sealer to set for 7 days at 37°c in an incubator (16,17). after the storage period, the roots were embedded in clear orthodontic resin. metal mould (length 70mm, width 60mm and height 30mm) containing three cylindrical moulds of (diameter 12 mm * height 25mm) were loaded with freshly prepared acrylic. with the aid of dental surveyor the roots would be centrally located within the acrylic blocks and ensure that the sectioning would be perpendicular to the long axis of the roots, the metal mould loaded with the freshly prepared acrylic, the rod of the surveyor with the root fixed on its face was pushed into the acrylic paste with gentle pressure to allow the complete embedding of the root into the acrylic and to allow the escape of the excess material (18) the material was allowed to cure under cooled water 20°c, which was necessary to compensate for the anticipated rise in the temperature of the samples subsequent to the exothermic curing reaction of the cold cure resin. the acrylic moulds were allowed to cure completely for at least 30 min as recommended by the manufacturers. after complete curing of the acrylic mould, the metal mould was open. the excess acrylic was cut off using diamond disk. the roots were horizontally cut with flow of cold water (1925°c) to minimize smearing. to get three sections of 1mm in thickness coronal, middle and apical, the cuts were made at 1,5,8 mm from coronal reference point respectively. push-out test was performed by applying a compressive load to the apical aspect of each slice via a cylindrical plunger mounted on tinius-olsen universal testing machine managed by computer software. samples were examined under the nikon metallurgical microscope (magnification 50x) and pictures of both sides of each section are taken with digital camera which was connected with microscope, and measurements calculated using lucia g software analysis program. the diameter of both apical and coronal side of the section at each level was obtained from which the radius was calculated. the obturated area of the section at each level was measured from the apical side to determine the size of punch pin. three different sizes of punch pins were used; (1 mm, 0.7mm, and 0.3mm) diameter for the coronal, middle and apical slices respectively. the punch pins should provide almost complete coverage over the main cone without touching the canal wall and sealer (16,19). each section was placed on perforated metal base designed by the researcher; the diameter of holes about 3mm to provide clearance for the obturating material when it dislodged from the tooth slice. the sections were placed above the metal base with its apical direction upward and the coronal direction downwards because the load should be applied to the apical aspect of the root section and in an apical–coronal direction. the root filling in each section subjected to loading using a universal testing machine. loading was performed on microcomputer electrical control universal testing machine (wdw50) at a speed of 0.5 mm / min in an apical-coronal direction until the first dislodgment of obturating material and a sudden drop along the load deflection. the punch was positioned so that only contacts the core filling material and avoided contact with the sealer and root canal walls (16). the maximum failure load was recorded in newton (n) and was used to calculate the pushout bond strength in megapascals (mpa) according to the following formula (8): push-out bond strength (mpa) = maximum load (n)/ adhesive area of root canal filling (mm2) the adhesion (bonding) surface area of each section was calculated as: (πr1 + πr2)*l. l was calculated as π = 3.14; r1 = coronal radius, in mm; r2 = apical radius, in mm; h = thickness of section in mm, l = adhesion area. results and discussion a predominant trend in modern dentistry has been to search for biocompatible agents, especially those to be used in direct contact with tissues. accordingly there was growing interest in the use of medicinal plants for therapeutic application. in endodontics because of the cytotoxic reactions of the most of the commercial intra-canal medicaments used and their inability to eliminate bacteria from dentinal tubules, and the complexity and high cost of some techniques like laser, trend of recent medicine attends to use biologic medication extracted from natural plants (21). increased adhesion depends on the area of contact, which can be increased by using dej bagh college dentistry vol. 26(2), june 2014 the effect of waterlase restorative dentistry 4 mineralizing agents. ethylene diaminetetraacetic acid (edta) solution in different concentrations is able to remove the smear layer and expose a large number of dentinal tubules (22). comparison of different groups table 1 showed the descriptive statistics and groups' difference at each level. at the coronal and apical thirds, anova test showed nonsignificant differences among the groups. this may indicate that all the groups had the ability to remove smear layer in a comparable values. however at the middle third, there was significant difference between groups and lsd test (table 2) showed that waterlase laser showed significant difference when compared with herbal extract (green tea and siwak) and 17%edta groups. although er,cr:ysgg laser had proven to have the ability of smear layer removal at power of 1.25 watts, it may lead to melting and closure of dentinal tubules which result in reduction of surface area to which bioceramic sealer may adhere. this might be the reason that waterlase showed less values of push-out strength (23). these results come in agreement with study done by scoop et al. (23) who used sem to evaluate the effect of er,cr:ysgg laser on morphological changes in root canal wall and showed that it had the ability to remove smear layer effectively. also these results are in line with another study done by balto et al. (24) on the effect of salvadora persica (siwak) extract on intra-canal smear layer removal and they exhibited that at concentration of 5 mg/ml it was as effective as 17% edta in removing smear layer at coronal third. table 1: descriptive statistics and groups differences levels groups descriptive statistics groups differences (anova) mean s.d. f-test p-value coronal edta 3.97 0.16 1.83 0.16 (ns) waterlase laser 4.49 0.73 siwak 4.06 0.30 green tea 4.22 0.71 middle edta 4.49 0.33 3.07 0.04 (s) waterlase laser 3.98 0.42 siwak 4.55 0.58 green tea 4.62 0.70 apical edta 4.89 0.60 0.07 0.98 (ns) waterlase laser 4.86 0.74 siwak 4.96 0.66 green tea 4.84 0.53 table 2: lsd test after anova levels groups mean difference p-value middle edta waterlase laser 0.51 0.037 (s) siwak -0.06 0.794 (ns) green tea -0.13 0.583 (ns) waterlase laser siwak -0.57 0.020 (s) green tea -0.64 0.010 (hs) siwak green tea -0.07 0.772 (ns) ns: non-significant, s: significant, hs: highly significant comparison of different levels table 3 showed the descriptive statistics and levels' difference at each group. anova test showed significant differences among different levels within edta, waterlase and siwak. however lsd test (table 4) showed that within edta group the difference was significant between all the three areas (coronal, middle and apical), and within waterlase group the difference only was significant between middle and apical areas, while siwak showed significant difference between coronal and apical areas only. however in all groups the mean push-out strength value was greatest in apical area and least in coronal area and the middle area was in between, except in waterlase the middle area showed the least mean push-out strength. these results are attributed to both the type of smear layer removing method and the obturation itself. the cold lateral condensation technique usually produces better obturation apically than middle and coronally because of the matching j bagh college dentistry vol. 26(2), june 2014 the effect of waterlase restorative dentistry 5 between the cross-section of master cone and the instrumented canal. while at the middle and coronal levels, the quality of obturation is totally dependent on the lateral condensation which is less reliable. however during irrigation the needle was inserted into apical area, so that the irrigating solution was more fresh and stronger apically than middle and coronal areas. hence more effective smear layer removal was in apical area than middle and coronal areas. in waterlase, the middle area showed the least mean push-out strength value. this may be due to ledges and zips formation during irradiation of the canal with er,cr:ysgg laser that may have adverse effect on the quality of obturation of middle area which result in reduced push-out strength (25). these results coincided with scoop et al. (23) whom also stated that smear layer was removed more efficiently from apical than middle and coronal areas. however the result disagreed with khademi and feizianfard (26) whom results showed that the middle third of root canal was cleaner of smear layer than coronal third, and the apical third showed the greatest amount of smear layer. as conclusion; herbal extracts used in this study (siwak and green tea) can be used safely as intra-canal irrigant for smear layer removal with efficiency that is comparable with conventional synthetic materials (edta) and more complicated methods (waterlase). table 3: descriptive statistics and levels differences groups levels descriptive statistics levels differences (anova) mean s.d. f-test p-value edta coronal 3.97 0.16 12.86 0.000 (hs) middle 4.49 0.33 apical 4.89 0.60 waterlase laser coronal 4.49 0.73 4.66 0.02 (s) middle 3.98 0.42 apical 4.86 0.74 siwak coronal 4.06 0.30 7.01 0.004 (hs) middle 4.55 0.58 apical 4.96 0.66 green tea coronal 4.22 0.71 2.31 0.12 (ns) middle 4.62 0.70 apical 4.84 0.53 table 4: lsd test after anova groups levels mean difference p-value edta coronal middle -0.52 0.008 (hs) apical -0.92 0.000 (hs) middle apical -0.40 0.036 (s) waterlase laser coronal middle 0.52 0.085 (ns) apical -0.36 0.222 (ns) middle apical -0.88 0.005 (hs) siwak coronal middle -0.49 0.052 (ns) apical -0.90 0.001 (hs) middle apical -0.41 0.1 (ns) ns: non-significant, s: significant, hs: highly significant references 1. tagger m, tagger e, tjan ahl, bakland lk. measurement of adhesion of endodontic sealers to dentin. j endod 2002; 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